ht6560b: remove old history
[safe/jmp/linux-2.6] / drivers / ide / ide-tape.c
index 2fe4e8f..82c2afe 100644 (file)
@@ -15,7 +15,7 @@
  * Documentation/ide/ChangeLog.ide-tape.1995-2002
  */
 
-#define IDETAPE_VERSION "1.19"
+#define IDETAPE_VERSION "1.20"
 
 #include <linux/module.h>
 #include <linux/types.h>
@@ -39,9 +39,9 @@
 #include <scsi/scsi.h>
 
 #include <asm/byteorder.h>
-#include <asm/irq.h>
-#include <asm/uaccess.h>
-#include <asm/io.h>
+#include <linux/irq.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
 #include <asm/unaligned.h>
 #include <linux/mtio.h>
 
@@ -72,40 +72,17 @@ enum {
 #endif
 
 /**************************** Tunable parameters *****************************/
-
-
-/*
- *     Pipelined mode parameters.
- *
- *     We try to use the minimum number of stages which is enough to
- *     keep the tape constantly streaming. To accomplish that, we implement
- *     a feedback loop around the maximum number of stages:
- *
- *     We start from MIN maximum stages (we will not even use MIN stages
- *      if we don't need them), increment it by RATE*(MAX-MIN)
- *     whenever we sense that the pipeline is empty, until we reach
- *     the optimum value or until we reach MAX.
- *
- *     Setting the following parameter to 0 is illegal: the pipelined mode
- *     cannot be disabled (idetape_calculate_speeds() divides by
- *     tape->max_stages.)
- */
-#define IDETAPE_MIN_PIPELINE_STAGES      1
-#define IDETAPE_MAX_PIPELINE_STAGES    400
-#define IDETAPE_INCREASE_STAGES_RATE    20
-
 /*
- *     After each failed packet command we issue a request sense command
- *     and retry the packet command IDETAPE_MAX_PC_RETRIES times.
+ * After each failed packet command we issue a request sense command and retry
+ * the packet command IDETAPE_MAX_PC_RETRIES times.
  *
- *     Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
+ * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
  */
 #define IDETAPE_MAX_PC_RETRIES         3
 
 /*
- *     With each packet command, we allocate a buffer of
- *     IDETAPE_PC_BUFFER_SIZE bytes. This is used for several packet
- *     commands (Not for READ/WRITE commands).
+ * With each packet command, we allocate a buffer of IDETAPE_PC_BUFFER_SIZE
+ * bytes. This is used for several packet commands (Not for READ/WRITE commands)
  */
 #define IDETAPE_PC_BUFFER_SIZE         256
 
@@ -124,48 +101,39 @@ enum {
 #define IDETAPE_WAIT_CMD               (900*HZ)
 
 /*
- *     The following parameter is used to select the point in the internal
- *     tape fifo in which we will start to refill the buffer. Decreasing
- *     the following parameter will improve the system's latency and
- *     interactive response, while using a high value might improve system
- *     throughput.
+ * The following parameter is used to select the point in the internal tape fifo
+ * in which we will start to refill the buffer. Decreasing the following
+ * parameter will improve the system's latency and interactive response, while
+ * using a high value might improve system throughput.
  */
-#define IDETAPE_FIFO_THRESHOLD                 2
+#define IDETAPE_FIFO_THRESHOLD         2
 
 /*
- *     DSC polling parameters.
- *
- *     Polling for DSC (a single bit in the status register) is a very
- *     important function in ide-tape. There are two cases in which we
- *     poll for DSC:
+ * DSC polling parameters.
  *
- *     1.      Before a read/write packet command, to ensure that we
- *             can transfer data from/to the tape's data buffers, without
- *             causing an actual media access. In case the tape is not
- *             ready yet, we take out our request from the device
- *             request queue, so that ide.c will service requests from
- *             the other device on the same interface meanwhile.
+ * Polling for DSC (a single bit in the status register) is a very important
+ * function in ide-tape. There are two cases in which we poll for DSC:
  *
- *     2.      After the successful initialization of a "media access
- *             packet command", which is a command which can take a long
- *             time to complete (it can be several seconds or even an hour).
+ * 1. Before a read/write packet command, to ensure that we can transfer data
+ * from/to the tape's data buffers, without causing an actual media access.
+ * In case the tape is not ready yet, we take out our request from the device
+ * request queue, so that ide.c could service requests from the other device
+ * on the same interface in the meantime.
  *
- *             Again, we postpone our request in the middle to free the bus
- *             for the other device. The polling frequency here should be
- *             lower than the read/write frequency since those media access
- *             commands are slow. We start from a "fast" frequency -
- *             IDETAPE_DSC_MA_FAST (one second), and if we don't receive DSC
- *             after IDETAPE_DSC_MA_THRESHOLD (5 minutes), we switch it to a
- *             lower frequency - IDETAPE_DSC_MA_SLOW (1 minute).
+ * 2. After the successful initialization of a "media access packet command",
+ * which is a command that can take a long time to complete (the interval can
+ * range from several seconds to even an hour). Again, we postpone our request
+ * in the middle to free the bus for the other device. The polling frequency
+ * here should be lower than the read/write frequency since those media access
+ * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
+ * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
+ * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
  *
- *     We also set a timeout for the timer, in case something goes wrong.
- *     The timeout should be longer then the maximum execution time of a
- *     tape operation.
- */
-/*
- *     DSC timings.
+ * We also set a timeout for the timer, in case something goes wrong. The
+ * timeout should be longer then the maximum execution time of a tape operation.
  */
+
+/* DSC timings. */
 #define IDETAPE_DSC_RW_MIN             5*HZ/100        /* 50 msec */
 #define IDETAPE_DSC_RW_MAX             40*HZ/100       /* 400 msec */
 #define IDETAPE_DSC_RW_TIMEOUT         2*60*HZ         /* 2 minutes */
@@ -176,15 +144,6 @@ enum {
 
 /*************************** End of tunable parameters ***********************/
 
-/*
- *     Read/Write error simulation
- */
-#define SIMULATE_ERRORS                        0
-
-/*
- *     For general magnetic tape device compatibility.
- */
-
 /* tape directions */
 enum {
        IDETAPE_DIR_NONE  = (1 << 0),
@@ -199,55 +158,46 @@ struct idetape_bh {
        char *b_data;
 };
 
-/*
- *     Our view of a packet command.
- */
-typedef struct idetape_packet_command_s {
-       u8 c[12];                               /* Actual packet bytes */
-       int retries;                            /* On each retry, we increment retries */
-       int error;                              /* Error code */
-       int request_transfer;                   /* Bytes to transfer */
-       int actually_transferred;               /* Bytes actually transferred */
-       int buffer_size;                        /* Size of our data buffer */
-       struct idetape_bh *bh;
-       char *b_data;
-       int b_count;
-       u8 *buffer;                             /* Data buffer */
-       u8 *current_position;                   /* Pointer into the above buffer */
-       ide_startstop_t (*callback) (ide_drive_t *);    /* Called when this packet command is completed */
-       u8 pc_buffer[IDETAPE_PC_BUFFER_SIZE];   /* Temporary buffer */
-       unsigned long flags;                    /* Status/Action bit flags: long for set_bit */
-} idetape_pc_t;
+/* Tape door status */
+#define DOOR_UNLOCKED                  0
+#define DOOR_LOCKED                    1
+#define DOOR_EXPLICITLY_LOCKED         2
 
-/*
- *     Packet command flag bits.
- */
-/* Set when an error is considered normal - We won't retry */
-#define        PC_ABORT                        0
-/* 1 When polling for DSC on a media access command */
-#define PC_WAIT_FOR_DSC                        1
-/* 1 when we prefer to use DMA if possible */
-#define PC_DMA_RECOMMENDED             2
-/* 1 while DMA in progress */
-#define        PC_DMA_IN_PROGRESS              3
-/* 1 when encountered problem during DMA */
-#define        PC_DMA_ERROR                    4
-/* Data direction */
-#define        PC_WRITING                      5
+/* Some defines for the SPACE command */
+#define IDETAPE_SPACE_OVER_FILEMARK    1
+#define IDETAPE_SPACE_TO_EOD           3
+
+/* Some defines for the LOAD UNLOAD command */
+#define IDETAPE_LU_LOAD_MASK           1
+#define IDETAPE_LU_RETENSION_MASK      2
+#define IDETAPE_LU_EOT_MASK            4
 
 /*
- *     A pipeline stage.
+ * Special requests for our block device strategy routine.
+ *
+ * In order to service a character device command, we add special requests to
+ * the tail of our block device request queue and wait for their completion.
  */
-typedef struct idetape_stage_s {
-       struct request rq;                      /* The corresponding request */
-       struct idetape_bh *bh;                  /* The data buffers */
-       struct idetape_stage_s *next;           /* Pointer to the next stage */
-} idetape_stage_t;
+
+enum {
+       REQ_IDETAPE_PC1         = (1 << 0), /* packet command (first stage) */
+       REQ_IDETAPE_PC2         = (1 << 1), /* packet command (second stage) */
+       REQ_IDETAPE_READ        = (1 << 2),
+       REQ_IDETAPE_WRITE       = (1 << 3),
+};
+
+/* Error codes returned in rq->errors to the higher part of the driver. */
+#define IDETAPE_ERROR_GENERAL          101
+#define IDETAPE_ERROR_FILEMARK         102
+#define IDETAPE_ERROR_EOD              103
+
+/* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
+#define IDETAPE_BLOCK_DESCRIPTOR       0
+#define IDETAPE_CAPABILITIES_PAGE      0x2a
 
 /*
- *     Most of our global data which we need to save even as we leave the
- *     driver due to an interrupt or a timer event is stored in a variable
- *     of type idetape_tape_t, defined below.
+ * Most of our global data which we need to save even as we leave the driver due
+ * to an interrupt or a timer event is stored in the struct defined below.
  */
 typedef struct ide_tape_obj {
        ide_drive_t     *drive;
@@ -271,11 +221,11 @@ typedef struct ide_tape_obj {
         *      retry, to get detailed information on what went wrong.
         */
        /* Current packet command */
-       idetape_pc_t *pc;
+       struct ide_atapi_pc *pc;
        /* Last failed packet command */
-       idetape_pc_t *failed_pc;
+       struct ide_atapi_pc *failed_pc;
        /* Packet command stack */
-       idetape_pc_t pc_stack[IDETAPE_PC_STACK];
+       struct ide_atapi_pc pc_stack[IDETAPE_PC_STACK];
        /* Next free packet command storage space */
        int pc_stack_index;
        struct request rq_stack[IDETAPE_PC_STACK];
@@ -283,15 +233,12 @@ typedef struct ide_tape_obj {
        int rq_stack_index;
 
        /*
-        *      DSC polling variables.
+        * DSC polling variables.
         *
-        *      While polling for DSC we use postponed_rq to postpone the
-        *      current request so that ide.c will be able to service
-        *      pending requests on the other device. Note that at most
-        *      we will have only one DSC (usually data transfer) request
-        *      in the device request queue. Additional requests can be
-        *      queued in our internal pipeline, but they will be visible
-        *      to ide.c only one at a time.
+        * While polling for DSC we use postponed_rq to postpone the current
+        * request so that ide.c will be able to service pending requests on the
+        * other device. Note that at most we will have only one DSC (usually
+        * data transfer) request in the device request queue.
         */
        struct request *postponed_rq;
        /* The time in which we started polling for DSC */
@@ -303,21 +250,15 @@ typedef struct ide_tape_obj {
        unsigned long dsc_poll_freq;
        unsigned long dsc_timeout;
 
-       /*
-        *      Read position information
-        */
+       /* Read position information */
        u8 partition;
        /* Current block */
        unsigned int first_frame;
 
-       /*
-        *      Last error information
-        */
+       /* Last error information */
        u8 sense_key, asc, ascq;
 
-       /*
-        *      Character device operation
-        */
+       /* Character device operation */
        unsigned int minor;
        /* device name */
        char name[4];
@@ -332,62 +273,32 @@ typedef struct ide_tape_obj {
        u8 caps[20];
 
        /*
-        *      Active data transfer request parameters.
-        *
-        *      At most, there is only one ide-tape originated data transfer
-        *      request in the device request queue. This allows ide.c to
-        *      easily service requests from the other device when we
-        *      postpone our active request. In the pipelined operation
-        *      mode, we use our internal pipeline structure to hold
-        *      more data requests.
+        * Active data transfer request parameters.
         *
-        *      The data buffer size is chosen based on the tape's
-        *      recommendation.
+        * At most, there is only one ide-tape originated data transfer request
+        * in the device request queue. This allows ide.c to easily service
+        * requests from the other device when we postpone our active request.
         */
-       /* Ptr to the request which is waiting in the device request queue */
-       struct request *active_data_rq;
-       /* Data buffer size (chosen based on the tape's recommendation */
-       int stage_size;
-       idetape_stage_t *merge_stage;
-       int merge_stage_size;
+
+       /* Data buffer size chosen based on the tape's recommendation */
+       int buffer_size;
+       /* merge buffer */
+       struct idetape_bh *merge_bh;
+       /* size of the merge buffer */
+       int merge_bh_size;
+       /* pointer to current buffer head within the merge buffer */
        struct idetape_bh *bh;
        char *b_data;
        int b_count;
-       
-       /*
-        *      Pipeline parameters.
-        *
-        *      To accomplish non-pipelined mode, we simply set the following
-        *      variables to zero (or NULL, where appropriate).
-        */
-       /* Number of currently used stages */
-       int nr_stages;
-       /* Number of pending stages */
-       int nr_pending_stages;
-       /* We will not allocate more than this number of stages */
-       int max_stages, min_pipeline, max_pipeline;
-       /* The first stage which will be removed from the pipeline */
-       idetape_stage_t *first_stage;
-       /* The currently active stage */
-       idetape_stage_t *active_stage;
-       /* Will be serviced after the currently active request */
-       idetape_stage_t *next_stage;
-       /* New requests will be added to the pipeline here */
-       idetape_stage_t *last_stage;
-       /* Optional free stage which we can use */
-       idetape_stage_t *cache_stage;
-       int pages_per_stage;
+
+       int pages_per_buffer;
        /* Wasted space in each stage */
        int excess_bh_size;
 
-       /* Status/Action flags: long for set_bit */
-       unsigned long flags;
        /* protects the ide-tape queue */
        spinlock_t lock;
 
-       /*
-        * Measures average tape speed
-        */
+       /* Measures average tape speed */
        unsigned long avg_time;
        int avg_size;
        int avg_speed;
@@ -399,51 +310,6 @@ typedef struct ide_tape_obj {
        /* the tape is write protected (hardware or opened as read-only) */
        char write_prot;
 
-       /*
-        * Limit the number of times a request can
-        * be postponed, to avoid an infinite postpone
-        * deadlock.
-        */
-       /* request postpone count limit */
-       int postpone_cnt;
-
-       /*
-        * Measures number of frames:
-        *
-        * 1. written/read to/from the driver pipeline (pipeline_head).
-        * 2. written/read to/from the tape buffers (idetape_bh).
-        * 3. written/read by the tape to/from the media (tape_head).
-        */
-       int pipeline_head;
-       int buffer_head;
-       int tape_head;
-       int last_tape_head;
-
-       /*
-        * Speed control at the tape buffers input/output
-        */
-       unsigned long insert_time;
-       int insert_size;
-       int insert_speed;
-       int max_insert_speed;
-       int measure_insert_time;
-
-       /*
-        * Speed regulation negative feedback loop
-        */
-       int speed_control;
-       int pipeline_head_speed;
-       int controlled_pipeline_head_speed;
-       int uncontrolled_pipeline_head_speed;
-       int controlled_last_pipeline_head;
-       unsigned long uncontrolled_pipeline_head_time;
-       unsigned long controlled_pipeline_head_time;
-       int controlled_previous_pipeline_head;
-       int uncontrolled_previous_pipeline_head;
-       unsigned long controlled_previous_head_time;
-       unsigned long uncontrolled_previous_head_time;
-       int restart_speed_control_req;
-
        u32 debug_mask;
 } idetape_tape_t;
 
@@ -456,114 +322,38 @@ static struct class *idetape_sysfs_class;
 #define ide_tape_g(disk) \
        container_of((disk)->private_data, struct ide_tape_obj, driver)
 
+static void ide_tape_release(struct kref *);
+
 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
 {
        struct ide_tape_obj *tape = NULL;
 
        mutex_lock(&idetape_ref_mutex);
        tape = ide_tape_g(disk);
-       if (tape)
+       if (tape) {
                kref_get(&tape->kref);
+               if (ide_device_get(tape->drive)) {
+                       kref_put(&tape->kref, ide_tape_release);
+                       tape = NULL;
+               }
+       }
        mutex_unlock(&idetape_ref_mutex);
        return tape;
 }
 
-static void ide_tape_release(struct kref *);
-
 static void ide_tape_put(struct ide_tape_obj *tape)
 {
        mutex_lock(&idetape_ref_mutex);
+       ide_device_put(tape->drive);
        kref_put(&tape->kref, ide_tape_release);
        mutex_unlock(&idetape_ref_mutex);
 }
 
 /*
- *     Tape door status
+ * The variables below are used for the character device interface. Additional
+ * state variables are defined in our ide_drive_t structure.
  */
-#define DOOR_UNLOCKED                  0
-#define DOOR_LOCKED                    1
-#define DOOR_EXPLICITLY_LOCKED         2
-
-/*
- *     Tape flag bits values.
- */
-#define IDETAPE_IGNORE_DSC             0
-#define IDETAPE_ADDRESS_VALID          1       /* 0 When the tape position is unknown */
-#define IDETAPE_BUSY                   2       /* Device already opened */
-#define IDETAPE_PIPELINE_ERROR         3       /* Error detected in a pipeline stage */
-#define IDETAPE_DETECT_BS              4       /* Attempt to auto-detect the current user block size */
-#define IDETAPE_FILEMARK               5       /* Currently on a filemark */
-#define IDETAPE_DRQ_INTERRUPT          6       /* DRQ interrupt device */
-#define IDETAPE_READ_ERROR             7
-#define IDETAPE_PIPELINE_ACTIVE                8       /* pipeline active */
-/* 0 = no tape is loaded, so we don't rewind after ejecting */
-#define IDETAPE_MEDIUM_PRESENT         9
-
-/*
- *     Some defines for the READ BUFFER command
- */
-#define IDETAPE_RETRIEVE_FAULTY_BLOCK  6
-
-/*
- *     Some defines for the SPACE command
- */
-#define IDETAPE_SPACE_OVER_FILEMARK    1
-#define IDETAPE_SPACE_TO_EOD           3
-
-/*
- *     Some defines for the LOAD UNLOAD command
- */
-#define IDETAPE_LU_LOAD_MASK           1
-#define IDETAPE_LU_RETENSION_MASK      2
-#define IDETAPE_LU_EOT_MASK            4
-
-/*
- *     Special requests for our block device strategy routine.
- *
- *     In order to service a character device command, we add special
- *     requests to the tail of our block device request queue and wait
- *     for their completion.
- */
-
-enum {
-       REQ_IDETAPE_PC1         = (1 << 0), /* packet command (first stage) */
-       REQ_IDETAPE_PC2         = (1 << 1), /* packet command (second stage) */
-       REQ_IDETAPE_READ        = (1 << 2),
-       REQ_IDETAPE_WRITE       = (1 << 3),
-       REQ_IDETAPE_READ_BUFFER = (1 << 4),
-};
-
-/*
- *     Error codes which are returned in rq->errors to the higher part
- *     of the driver.
- */
-#define        IDETAPE_ERROR_GENERAL           101
-#define        IDETAPE_ERROR_FILEMARK          102
-#define        IDETAPE_ERROR_EOD               103
-
-/*
- *     The following is used to format the general configuration word of
- *     the ATAPI IDENTIFY DEVICE command.
- */
-struct idetape_id_gcw {        
-       unsigned packet_size            :2;     /* Packet Size */
-       unsigned reserved234            :3;     /* Reserved */
-       unsigned drq_type               :2;     /* Command packet DRQ type */
-       unsigned removable              :1;     /* Removable media */
-       unsigned device_type            :5;     /* Device type */
-       unsigned reserved13             :1;     /* Reserved */
-       unsigned protocol               :2;     /* Protocol type */
-};
-
-/* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
-#define IDETAPE_BLOCK_DESCRIPTOR       0
-#define        IDETAPE_CAPABILITIES_PAGE       0x2a
-
-/*
- *     The variables below are used for the character device interface.
- *     Additional state variables are defined in our ide_drive_t structure.
- */
-static struct ide_tape_obj * idetape_devs[MAX_HWIFS * MAX_DRIVES];
+static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
 
 #define ide_tape_f(file) ((file)->private_data)
 
@@ -579,24 +369,8 @@ static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
        return tape;
 }
 
-/*
- *      Function declarations
- *
- */
-static int idetape_chrdev_release (struct inode *inode, struct file *filp);
-static void idetape_write_release (ide_drive_t *drive, unsigned int minor);
-
-/*
- * Too bad. The drive wants to send us data which we are not ready to accept.
- * Just throw it away.
- */
-static void idetape_discard_data (ide_drive_t *drive, unsigned int bcount)
-{
-       while (bcount--)
-               (void) HWIF(drive)->INB(IDE_DATA_REG);
-}
-
-static void idetape_input_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
+static void idetape_input_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
+                                 unsigned int bcount)
 {
        struct idetape_bh *bh = pc->bh;
        int count;
@@ -605,11 +379,14 @@ static void idetape_input_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigne
                if (bh == NULL) {
                        printk(KERN_ERR "ide-tape: bh == NULL in "
                                "idetape_input_buffers\n");
-                       idetape_discard_data(drive, bcount);
+                       ide_pad_transfer(drive, 0, bcount);
                        return;
                }
-               count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), bcount);
-               HWIF(drive)->atapi_input_bytes(drive, bh->b_data + atomic_read(&bh->b_count), count);
+               count = min(
+                       (unsigned int)(bh->b_size - atomic_read(&bh->b_count)),
+                       bcount);
+               drive->hwif->tp_ops->input_data(drive, NULL, bh->b_data +
+                                       atomic_read(&bh->b_count), count);
                bcount -= count;
                atomic_add(count, &bh->b_count);
                if (atomic_read(&bh->b_count) == bh->b_size) {
@@ -621,24 +398,26 @@ static void idetape_input_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigne
        pc->bh = bh;
 }
 
-static void idetape_output_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
+static void idetape_output_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
+                                  unsigned int bcount)
 {
        struct idetape_bh *bh = pc->bh;
        int count;
 
        while (bcount) {
                if (bh == NULL) {
-                       printk(KERN_ERR "ide-tape: bh == NULL in "
-                               "idetape_output_buffers\n");
+                       printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
+                                       __func__);
                        return;
                }
                count = min((unsigned int)pc->b_count, (unsigned int)bcount);
-               HWIF(drive)->atapi_output_bytes(drive, pc->b_data, count);
+               drive->hwif->tp_ops->output_data(drive, NULL, pc->b_data, count);
                bcount -= count;
                pc->b_data += count;
                pc->b_count -= count;
                if (!pc->b_count) {
-                       pc->bh = bh = bh->b_reqnext;
+                       bh = bh->b_reqnext;
+                       pc->bh = bh;
                        if (bh) {
                                pc->b_data = bh->b_data;
                                pc->b_count = atomic_read(&bh->b_count);
@@ -647,18 +426,18 @@ static void idetape_output_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsign
        }
 }
 
-static void idetape_update_buffers (idetape_pc_t *pc)
+static void idetape_update_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc)
 {
        struct idetape_bh *bh = pc->bh;
        int count;
-       unsigned int bcount = pc->actually_transferred;
+       unsigned int bcount = pc->xferred;
 
-       if (test_bit(PC_WRITING, &pc->flags))
+       if (pc->flags & PC_FLAG_WRITING)
                return;
        while (bcount) {
                if (bh == NULL) {
-                       printk(KERN_ERR "ide-tape: bh == NULL in "
-                               "idetape_update_buffers\n");
+                       printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
+                                       __func__);
                        return;
                }
                count = min((unsigned int)bh->b_size, (unsigned int)bcount);
@@ -676,14 +455,14 @@ static void idetape_update_buffers (idetape_pc_t *pc)
  *     driver. A storage space for a maximum of IDETAPE_PC_STACK packet
  *     commands is allocated at initialization time.
  */
-static idetape_pc_t *idetape_next_pc_storage (ide_drive_t *drive)
+static struct ide_atapi_pc *idetape_next_pc_storage(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
 
        debug_log(DBG_PCRQ_STACK, "pc_stack_index=%d\n", tape->pc_stack_index);
 
        if (tape->pc_stack_index == IDETAPE_PC_STACK)
-               tape->pc_stack_index=0;
+               tape->pc_stack_index = 0;
        return (&tape->pc_stack[tape->pc_stack_index++]);
 }
 
@@ -692,48 +471,33 @@ static idetape_pc_t *idetape_next_pc_storage (ide_drive_t *drive)
  *     Since we queue packet commands in the request queue, we need to
  *     allocate a request, along with the allocation of a packet command.
  */
+
 /**************************************************************
  *                                                            *
  *  This should get fixed to use kmalloc(.., GFP_ATOMIC)      *
  *  followed later on by kfree().   -ml                       *
  *                                                            *
  **************************************************************/
-static struct request *idetape_next_rq_storage (ide_drive_t *drive)
+
+static struct request *idetape_next_rq_storage(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
 
        debug_log(DBG_PCRQ_STACK, "rq_stack_index=%d\n", tape->rq_stack_index);
 
        if (tape->rq_stack_index == IDETAPE_PC_STACK)
-               tape->rq_stack_index=0;
+               tape->rq_stack_index = 0;
        return (&tape->rq_stack[tape->rq_stack_index++]);
 }
 
 /*
- *     idetape_init_pc initializes a packet command.
- */
-static void idetape_init_pc (idetape_pc_t *pc)
-{
-       memset(pc->c, 0, 12);
-       pc->retries = 0;
-       pc->flags = 0;
-       pc->request_transfer = 0;
-       pc->buffer = pc->pc_buffer;
-       pc->buffer_size = IDETAPE_PC_BUFFER_SIZE;
-       pc->bh = NULL;
-       pc->b_data = NULL;
-}
-
-/*
  * called on each failed packet command retry to analyze the request sense. We
  * currently do not utilize this information.
  */
 static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t *pc = tape->failed_pc;
+       struct ide_atapi_pc *pc = tape->failed_pc;
 
        tape->sense_key = sense[2] & 0xF;
        tape->asc       = sense[12];
@@ -742,12 +506,12 @@ static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
        debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n",
                 pc->c[0], tape->sense_key, tape->asc, tape->ascq);
 
-       /* Correct pc->actually_transferred by asking the tape.  */
-       if (test_bit(PC_DMA_ERROR, &pc->flags)) {
-               pc->actually_transferred = pc->request_transfer -
+       /* Correct pc->xferred by asking the tape.       */
+       if (pc->flags & PC_FLAG_DMA_ERROR) {
+               pc->xferred = pc->req_xfer -
                        tape->blk_size *
-                       be32_to_cpu(get_unaligned((u32 *)&sense[3]));
-               idetape_update_buffers(pc);
+                       get_unaligned_be32(&sense[3]);
+               idetape_update_buffers(drive, pc);
        }
 
        /*
@@ -762,180 +526,67 @@ static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
                        /* don't report an error, everything's ok */
                        pc->error = 0;
                        /* don't retry read/write */
-                       set_bit(PC_ABORT, &pc->flags);
+                       pc->flags |= PC_FLAG_ABORT;
                }
        }
        if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
                pc->error = IDETAPE_ERROR_FILEMARK;
-               set_bit(PC_ABORT, &pc->flags);
+               pc->flags |= PC_FLAG_ABORT;
        }
        if (pc->c[0] == WRITE_6) {
                if ((sense[2] & 0x40) || (tape->sense_key == 0xd
                     && tape->asc == 0x0 && tape->ascq == 0x2)) {
                        pc->error = IDETAPE_ERROR_EOD;
-                       set_bit(PC_ABORT, &pc->flags);
+                       pc->flags |= PC_FLAG_ABORT;
                }
        }
        if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
                if (tape->sense_key == 8) {
                        pc->error = IDETAPE_ERROR_EOD;
-                       set_bit(PC_ABORT, &pc->flags);
+                       pc->flags |= PC_FLAG_ABORT;
                }
-               if (!test_bit(PC_ABORT, &pc->flags) &&
-                   pc->actually_transferred)
+               if (!(pc->flags & PC_FLAG_ABORT) &&
+                   pc->xferred)
                        pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
        }
 }
 
-static void idetape_activate_next_stage(ide_drive_t *drive)
+/* Free data buffers completely. */
+static void ide_tape_kfree_buffer(idetape_tape_t *tape)
 {
-       idetape_tape_t *tape = drive->driver_data;
-       idetape_stage_t *stage = tape->next_stage;
-       struct request *rq = &stage->rq;
+       struct idetape_bh *prev_bh, *bh = tape->merge_bh;
 
-       debug_log(DBG_PROCS, "Enter %s\n", __func__);
+       while (bh) {
+               u32 size = bh->b_size;
 
-       if (stage == NULL) {
-               printk(KERN_ERR "ide-tape: bug: Trying to activate a non"
-                               " existing stage\n");
-               return;
-       }
-
-       rq->rq_disk = tape->disk;
-       rq->buffer = NULL;
-       rq->special = (void *)stage->bh;
-       tape->active_data_rq = rq;
-       tape->active_stage = stage;
-       tape->next_stage = stage->next;
-}
+               while (size) {
+                       unsigned int order = fls(size >> PAGE_SHIFT)-1;
 
-/*
- *     idetape_increase_max_pipeline_stages is a part of the feedback
- *     loop which tries to find the optimum number of stages. In the
- *     feedback loop, we are starting from a minimum maximum number of
- *     stages, and if we sense that the pipeline is empty, we try to
- *     increase it, until we reach the user compile time memory limit.
- */
-static void idetape_increase_max_pipeline_stages (ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       int increase = (tape->max_pipeline - tape->min_pipeline) / 10;
-
-       debug_log(DBG_PROCS, "Enter %s\n", __func__);
+                       if (bh->b_data)
+                               free_pages((unsigned long)bh->b_data, order);
 
-       tape->max_stages += max(increase, 1);
-       tape->max_stages = max(tape->max_stages, tape->min_pipeline);
-       tape->max_stages = min(tape->max_stages, tape->max_pipeline);
-}
-
-/*
- *     idetape_kfree_stage calls kfree to completely free a stage, along with
- *     its related buffers.
- */
-static void __idetape_kfree_stage (idetape_stage_t *stage)
-{
-       struct idetape_bh *prev_bh, *bh = stage->bh;
-       int size;
-
-       while (bh != NULL) {
-               if (bh->b_data != NULL) {
-                       size = (int) bh->b_size;
-                       while (size > 0) {
-                               free_page((unsigned long) bh->b_data);
-                               size -= PAGE_SIZE;
-                               bh->b_data += PAGE_SIZE;
-                       }
+                       size &= (order-1);
+                       bh->b_data += (1 << order) * PAGE_SIZE;
                }
                prev_bh = bh;
                bh = bh->b_reqnext;
                kfree(prev_bh);
        }
-       kfree(stage);
-}
-
-static void idetape_kfree_stage (idetape_tape_t *tape, idetape_stage_t *stage)
-{
-       __idetape_kfree_stage(stage);
 }
 
-/*
- *     idetape_remove_stage_head removes tape->first_stage from the pipeline.
- *     The caller should avoid race conditions.
- */
-static void idetape_remove_stage_head (ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       idetape_stage_t *stage;
-
-       debug_log(DBG_PROCS, "Enter %s\n", __func__);
-
-       if (tape->first_stage == NULL) {
-               printk(KERN_ERR "ide-tape: bug: tape->first_stage is NULL\n");
-               return;
-       }
-       if (tape->active_stage == tape->first_stage) {
-               printk(KERN_ERR "ide-tape: bug: Trying to free our active "
-                               "pipeline stage\n");
-               return;
-       }
-       stage = tape->first_stage;
-       tape->first_stage = stage->next;
-       idetape_kfree_stage(tape, stage);
-       tape->nr_stages--;
-       if (tape->first_stage == NULL) {
-               tape->last_stage = NULL;
-               if (tape->next_stage != NULL)
-                       printk(KERN_ERR "ide-tape: bug: tape->next_stage != NULL\n");
-               if (tape->nr_stages)
-                       printk(KERN_ERR "ide-tape: bug: nr_stages should be 0 now\n");
-       }
-}
-
-/*
- * This will free all the pipeline stages starting from new_last_stage->next
- * to the end of the list, and point tape->last_stage to new_last_stage.
- */
-static void idetape_abort_pipeline(ide_drive_t *drive,
-                                  idetape_stage_t *new_last_stage)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       idetape_stage_t *stage = new_last_stage->next;
-       idetape_stage_t *nstage;
-
-       debug_log(DBG_PROCS, "%s: Enter %s\n", tape->name, __func__);
-
-       while (stage) {
-               nstage = stage->next;
-               idetape_kfree_stage(tape, stage);
-               --tape->nr_stages;
-               --tape->nr_pending_stages;
-               stage = nstage;
-       }
-       if (new_last_stage)
-               new_last_stage->next = NULL;
-       tape->last_stage = new_last_stage;
-       tape->next_stage = NULL;
-}
-
-/*
- *     idetape_end_request is used to finish servicing a request, and to
- *     insert a pending pipeline request into the main device queue.
- */
 static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects)
 {
        struct request *rq = HWGROUP(drive)->rq;
        idetape_tape_t *tape = drive->driver_data;
        unsigned long flags;
        int error;
-       int remove_stage = 0;
-       idetape_stage_t *active_stage;
 
        debug_log(DBG_PROCS, "Enter %s\n", __func__);
 
        switch (uptodate) {
-               case 0: error = IDETAPE_ERROR_GENERAL; break;
-               case 1: error = 0; break;
-               default: error = uptodate;
+       case 0: error = IDETAPE_ERROR_GENERAL; break;
+       case 1: error = 0; break;
+       default: error = uptodate;
        }
        rq->errors = error;
        if (error)
@@ -948,109 +599,126 @@ static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects)
 
        spin_lock_irqsave(&tape->lock, flags);
 
-       /* The request was a pipelined data transfer request */
-       if (tape->active_data_rq == rq) {
-               active_stage = tape->active_stage;
-               tape->active_stage = NULL;
-               tape->active_data_rq = NULL;
-               tape->nr_pending_stages--;
-               if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
-                       remove_stage = 1;
-                       if (error) {
-                               set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
-                               if (error == IDETAPE_ERROR_EOD)
-                                       idetape_abort_pipeline(drive, active_stage);
-                       }
-               } else if (rq->cmd[0] & REQ_IDETAPE_READ) {
-                       if (error == IDETAPE_ERROR_EOD) {
-                               set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
-                               idetape_abort_pipeline(drive, active_stage);
-                       }
-               }
-               if (tape->next_stage != NULL) {
-                       idetape_activate_next_stage(drive);
-
-                       /*
-                        * Insert the next request into the request queue.
-                        */
-                       (void)ide_do_drive_cmd(drive, tape->active_data_rq,
-                                               ide_end);
-               } else if (!error) {
-                               idetape_increase_max_pipeline_stages(drive);
-               }
-       }
        ide_end_drive_cmd(drive, 0, 0);
-//     blkdev_dequeue_request(rq);
-//     drive->rq = NULL;
-//     end_that_request_last(rq);
-
-       if (remove_stage)
-               idetape_remove_stage_head(drive);
-       if (tape->active_data_rq == NULL)
-               clear_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
+
        spin_unlock_irqrestore(&tape->lock, flags);
        return 0;
 }
 
-static ide_startstop_t idetape_request_sense_callback (ide_drive_t *drive)
+static void ide_tape_callback(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
+       struct ide_atapi_pc *pc = tape->pc;
+       int uptodate = pc->error ? 0 : 1;
 
        debug_log(DBG_PROCS, "Enter %s\n", __func__);
 
-       if (!tape->pc->error) {
-               idetape_analyze_error(drive, tape->pc->buffer);
-               idetape_end_request(drive, 1, 0);
-       } else {
-               printk(KERN_ERR "ide-tape: Error in REQUEST SENSE itself - Aborting request!\n");
-               idetape_end_request(drive, 0, 0);
+       if (tape->failed_pc == pc)
+               tape->failed_pc = NULL;
+
+       if (pc->c[0] == REQUEST_SENSE) {
+               if (uptodate)
+                       idetape_analyze_error(drive, pc->buf);
+               else
+                       printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
+                                       "itself - Aborting request!\n");
+       } else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
+               struct request *rq = drive->hwif->hwgroup->rq;
+               int blocks = pc->xferred / tape->blk_size;
+
+               tape->avg_size += blocks * tape->blk_size;
+
+               if (time_after_eq(jiffies, tape->avg_time + HZ)) {
+                       tape->avg_speed = tape->avg_size * HZ /
+                               (jiffies - tape->avg_time) / 1024;
+                       tape->avg_size = 0;
+                       tape->avg_time = jiffies;
+               }
+
+               tape->first_frame += blocks;
+               rq->current_nr_sectors -= blocks;
+
+               if (pc->error)
+                       uptodate = pc->error;
+       } else if (pc->c[0] == READ_POSITION && uptodate) {
+               u8 *readpos = tape->pc->buf;
+
+               debug_log(DBG_SENSE, "BOP - %s\n",
+                               (readpos[0] & 0x80) ? "Yes" : "No");
+               debug_log(DBG_SENSE, "EOP - %s\n",
+                               (readpos[0] & 0x40) ? "Yes" : "No");
+
+               if (readpos[0] & 0x4) {
+                       printk(KERN_INFO "ide-tape: Block location is unknown"
+                                        "to the tape\n");
+                       clear_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
+                       uptodate = 0;
+               } else {
+                       debug_log(DBG_SENSE, "Block Location - %u\n",
+                                       be32_to_cpup((__be32 *)&readpos[4]));
+
+                       tape->partition = readpos[1];
+                       tape->first_frame = be32_to_cpup((__be32 *)&readpos[4]);
+                       set_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags);
+               }
        }
-       return ide_stopped;
+
+       idetape_end_request(drive, uptodate, 0);
 }
 
-static void idetape_create_request_sense_cmd (idetape_pc_t *pc)
+static void idetape_init_pc(struct ide_atapi_pc *pc)
 {
-       idetape_init_pc(pc);    
+       memset(pc->c, 0, 12);
+       pc->retries = 0;
+       pc->flags = 0;
+       pc->req_xfer = 0;
+       pc->buf = pc->pc_buf;
+       pc->buf_size = IDETAPE_PC_BUFFER_SIZE;
+       pc->bh = NULL;
+       pc->b_data = NULL;
+}
+
+static void idetape_create_request_sense_cmd(struct ide_atapi_pc *pc)
+{
+       idetape_init_pc(pc);
        pc->c[0] = REQUEST_SENSE;
        pc->c[4] = 20;
-       pc->request_transfer = 20;
-       pc->callback = &idetape_request_sense_callback;
+       pc->req_xfer = 20;
 }
 
 static void idetape_init_rq(struct request *rq, u8 cmd)
 {
-       memset(rq, 0, sizeof(*rq));
+       blk_rq_init(NULL, rq);
        rq->cmd_type = REQ_TYPE_SPECIAL;
-       rq->cmd[0] = cmd;
+       rq->cmd[13] = cmd;
 }
 
 /*
- *     idetape_queue_pc_head generates a new packet command request in front
- *     of the request queue, before the current request, so that it will be
- *     processed immediately, on the next pass through the driver.
+ * Generate a new packet command request in front of the request queue, before
+ * the current request, so that it will be processed immediately, on the next
+ * pass through the driver. The function below is called from the request
+ * handling part of the driver (the "bottom" part). Safe storage for the request
+ * should be allocated with ide_tape_next_{pc,rq}_storage() prior to that.
  *
- *     idetape_queue_pc_head is called from the request handling part of
- *     the driver (the "bottom" part). Safe storage for the request should
- *     be allocated with idetape_next_pc_storage and idetape_next_rq_storage
- *     before calling idetape_queue_pc_head.
+ * Memory for those requests is pre-allocated at initialization time, and is
+ * limited to IDETAPE_PC_STACK requests. We assume that we have enough space for
+ * the maximum possible number of inter-dependent packet commands.
  *
- *     Memory for those requests is pre-allocated at initialization time, and
- *     is limited to IDETAPE_PC_STACK requests. We assume that we have enough
- *     space for the maximum possible number of inter-dependent packet commands.
- *
- *     The higher level of the driver - The ioctl handler and the character
- *     device handling functions should queue request to the lower level part
- *     and wait for their completion using idetape_queue_pc_tail or
- *     idetape_queue_rw_tail.
+ * The higher level of the driver - The ioctl handler and the character device
+ * handling functions should queue request to the lower level part and wait for
+ * their completion using idetape_queue_pc_tail or idetape_queue_rw_tail.
  */
-static void idetape_queue_pc_head (ide_drive_t *drive, idetape_pc_t *pc,struct request *rq)
+static void idetape_queue_pc_head(ide_drive_t *drive, struct ide_atapi_pc *pc,
+                                 struct request *rq)
 {
        struct ide_tape_obj *tape = drive->driver_data;
 
        idetape_init_rq(rq, REQ_IDETAPE_PC1);
+       rq->cmd_flags |= REQ_PREEMPT;
        rq->buffer = (char *) pc;
        rq->rq_disk = tape->disk;
-       (void) ide_do_drive_cmd(drive, rq, ide_preempt);
+       memcpy(rq->cmd, pc->c, 12);
+       ide_do_drive_cmd(drive, rq);
 }
 
 /*
@@ -1058,27 +726,24 @@ static void idetape_queue_pc_head (ide_drive_t *drive, idetape_pc_t *pc,struct r
  *     last packet command. We queue a request sense packet command in
  *     the head of the request list.
  */
-static ide_startstop_t idetape_retry_pc (ide_drive_t *drive)
+static void idetape_retry_pc(ide_drive_t *drive)
 {
-       idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t *pc;
+       struct ide_atapi_pc *pc;
        struct request *rq;
 
        (void)ide_read_error(drive);
        pc = idetape_next_pc_storage(drive);
        rq = idetape_next_rq_storage(drive);
        idetape_create_request_sense_cmd(pc);
-       set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
+       set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
        idetape_queue_pc_head(drive, pc, rq);
-       return ide_stopped;
 }
 
 /*
- *     idetape_postpone_request postpones the current request so that
- *     ide.c will be able to service requests from another device on
- *     the same hwgroup while we are polling for DSC.
+ * Postpone the current request so that ide.c will be able to service requests
+ * from another device on the same hwgroup while we are polling for DSC.
  */
-static void idetape_postpone_request (ide_drive_t *drive)
+static void idetape_postpone_request(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
 
@@ -1088,271 +753,91 @@ static void idetape_postpone_request (ide_drive_t *drive)
        ide_stall_queue(drive, tape->dsc_poll_freq);
 }
 
-typedef void idetape_io_buf(ide_drive_t *, idetape_pc_t *, unsigned int);
+static void ide_tape_handle_dsc(ide_drive_t *drive)
+{
+       idetape_tape_t *tape = drive->driver_data;
+
+       /* Media access command */
+       tape->dsc_polling_start = jiffies;
+       tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
+       tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
+       /* Allow ide.c to handle other requests */
+       idetape_postpone_request(drive);
+}
+
+static void ide_tape_io_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
+                               unsigned int bcount, int write)
+{
+       if (write)
+               idetape_output_buffers(drive, pc, bcount);
+       else
+               idetape_input_buffers(drive, pc, bcount);
+}
 
 /*
  * This is the usual interrupt handler which will be called during a packet
  * command. We will transfer some of the data (as requested by the drive) and
  * will re-point interrupt handler to us. When data transfer is finished, we
  * will act according to the algorithm described before
- * idetape_issue_packet_command.
+ * idetape_issue_pc.
  */
 static ide_startstop_t idetape_pc_intr(ide_drive_t *drive)
 {
-       ide_hwif_t *hwif = drive->hwif;
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t *pc = tape->pc;
-       xfer_func_t *xferfunc;
-       idetape_io_buf *iobuf;
-       unsigned int temp;
-#if SIMULATE_ERRORS
-       static int error_sim_count = 0;
-#endif
-       u16 bcount;
-       u8 stat, ireason;
-
-       debug_log(DBG_PROCS, "Enter %s - interrupt handler\n", __func__);
-
-       /* Clear the interrupt */
-       stat = ide_read_status(drive);
-
-       if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
-               if (hwif->ide_dma_end(drive) || (stat & ERR_STAT)) {
-                       /*
-                        * A DMA error is sometimes expected. For example,
-                        * if the tape is crossing a filemark during a
-                        * READ command, it will issue an irq and position
-                        * itself before the filemark, so that only a partial
-                        * data transfer will occur (which causes the DMA
-                        * error). In that case, we will later ask the tape
-                        * how much bytes of the original request were
-                        * actually transferred (we can't receive that
-                        * information from the DMA engine on most chipsets).
-                        */
-
-                       /*
-                        * On the contrary, a DMA error is never expected;
-                        * it usually indicates a hardware error or abort.
-                        * If the tape crosses a filemark during a READ
-                        * command, it will issue an irq and position itself
-                        * after the filemark (not before). Only a partial
-                        * data transfer will occur, but no DMA error.
-                        * (AS, 19 Apr 2001)
-                        */
-                       set_bit(PC_DMA_ERROR, &pc->flags);
-               } else {
-                       pc->actually_transferred = pc->request_transfer;
-                       idetape_update_buffers(pc);
-               }
-               debug_log(DBG_PROCS, "DMA finished\n");
-
-       }
-
-       /* No more interrupts */
-       if ((stat & DRQ_STAT) == 0) {
-               debug_log(DBG_SENSE, "Packet command completed, %d bytes"
-                               " transferred\n", pc->actually_transferred);
-
-               clear_bit(PC_DMA_IN_PROGRESS, &pc->flags);
-               local_irq_enable();
-
-#if SIMULATE_ERRORS
-               if ((pc->c[0] == WRITE_6 || pc->c[0] == READ_6) &&
-                   (++error_sim_count % 100) == 0) {
-                       printk(KERN_INFO "ide-tape: %s: simulating error\n",
-                               tape->name);
-                       stat |= ERR_STAT;
-               }
-#endif
-               if ((stat & ERR_STAT) && pc->c[0] == REQUEST_SENSE)
-                       stat &= ~ERR_STAT;
-               if ((stat & ERR_STAT) || test_bit(PC_DMA_ERROR, &pc->flags)) {
-                       /* Error detected */
-                       debug_log(DBG_ERR, "%s: I/O error\n", tape->name);
-
-                       if (pc->c[0] == REQUEST_SENSE) {
-                               printk(KERN_ERR "ide-tape: I/O error in request"
-                                               " sense command\n");
-                               return ide_do_reset(drive);
-                       }
-                       debug_log(DBG_ERR, "[cmd %x]: check condition\n",
-                                       pc->c[0]);
-
-                       /* Retry operation */
-                       return idetape_retry_pc(drive);
-               }
-               pc->error = 0;
-               if (test_bit(PC_WAIT_FOR_DSC, &pc->flags) &&
-                   (stat & SEEK_STAT) == 0) {
-                       /* Media access command */
-                       tape->dsc_polling_start = jiffies;
-                       tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
-                       tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
-                       /* Allow ide.c to handle other requests */
-                       idetape_postpone_request(drive);
-                       return ide_stopped;
-               }
-               if (tape->failed_pc == pc)
-                       tape->failed_pc = NULL;
-               /* Command finished - Call the callback function */
-               return pc->callback(drive);
-       }
-       if (test_and_clear_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
-               printk(KERN_ERR "ide-tape: The tape wants to issue more "
-                               "interrupts in DMA mode\n");
-               printk(KERN_ERR "ide-tape: DMA disabled, reverting to PIO\n");
-               ide_dma_off(drive);
-               return ide_do_reset(drive);
-       }
-       /* Get the number of bytes to transfer on this interrupt. */
-       bcount = (hwif->INB(IDE_BCOUNTH_REG) << 8) |
-                 hwif->INB(IDE_BCOUNTL_REG);
-
-       ireason = hwif->INB(IDE_IREASON_REG);
-
-       if (ireason & CD) {
-               printk(KERN_ERR "ide-tape: CoD != 0 in %s\n", __func__);
-               return ide_do_reset(drive);
-       }
-       if (((ireason & IO) == IO) == test_bit(PC_WRITING, &pc->flags)) {
-               /* Hopefully, we will never get here */
-               printk(KERN_ERR "ide-tape: We wanted to %s, ",
-                               (ireason & IO) ? "Write" : "Read");
-               printk(KERN_ERR "ide-tape: but the tape wants us to %s !\n",
-                               (ireason & IO) ? "Read" : "Write");
-               return ide_do_reset(drive);
-       }
-       if (!test_bit(PC_WRITING, &pc->flags)) {
-               /* Reading - Check that we have enough space */
-               temp = pc->actually_transferred + bcount;
-               if (temp > pc->request_transfer) {
-                       if (temp > pc->buffer_size) {
-                               printk(KERN_ERR "ide-tape: The tape wants to "
-                                       "send us more data than expected "
-                                       "- discarding data\n");
-                               idetape_discard_data(drive, bcount);
-                               ide_set_handler(drive, &idetape_pc_intr,
-                                               IDETAPE_WAIT_CMD, NULL);
-                               return ide_started;
-                       }
-                       debug_log(DBG_SENSE, "The tape wants to send us more "
-                               "data than expected - allowing transfer\n");
-               }
-               iobuf = &idetape_input_buffers;
-               xferfunc = hwif->atapi_input_bytes;
-       } else {
-               iobuf = &idetape_output_buffers;
-               xferfunc = hwif->atapi_output_bytes;
-       }
-
-       if (pc->bh)
-               iobuf(drive, pc, bcount);
-       else
-               xferfunc(drive, pc->current_position, bcount);
 
-       /* Update the current position */
-       pc->actually_transferred += bcount;
-       pc->current_position += bcount;
-
-       debug_log(DBG_SENSE, "[cmd %x] transferred %d bytes on that intr.\n",
-                       pc->c[0], bcount);
-
-       /* And set the interrupt handler again */
-       ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
-       return ide_started;
+       return ide_pc_intr(drive, tape->pc, idetape_pc_intr, IDETAPE_WAIT_CMD,
+                          NULL, idetape_update_buffers, idetape_retry_pc,
+                          ide_tape_handle_dsc, ide_tape_io_buffers);
 }
 
 /*
- *     Packet Command Interface
- *
- *     The current Packet Command is available in tape->pc, and will not
- *     change until we finish handling it. Each packet command is associated
- *     with a callback function that will be called when the command is
- *     finished.
+ * Packet Command Interface
  *
- *     The handling will be done in three stages:
+ * The current Packet Command is available in tape->pc, and will not change
+ * until we finish handling it. Each packet command is associated with a
+ * callback function that will be called when the command is finished.
  *
- *     1.      idetape_issue_packet_command will send the packet command to the
- *             drive, and will set the interrupt handler to idetape_pc_intr.
+ * The handling will be done in three stages:
  *
- *     2.      On each interrupt, idetape_pc_intr will be called. This step
- *             will be repeated until the device signals us that no more
- *             interrupts will be issued.
+ * 1. idetape_issue_pc will send the packet command to the drive, and will set
+ * the interrupt handler to idetape_pc_intr.
  *
- *     3.      ATAPI Tape media access commands have immediate status with a
- *             delayed process. In case of a successful initiation of a
- *             media access packet command, the DSC bit will be set when the
- *             actual execution of the command is finished. 
- *             Since the tape drive will not issue an interrupt, we have to
- *             poll for this event. In this case, we define the request as
- *             "low priority request" by setting rq_status to
- *             IDETAPE_RQ_POSTPONED,   set a timer to poll for DSC and exit
- *             the driver.
+ * 2. On each interrupt, idetape_pc_intr will be called. This step will be
+ * repeated until the device signals us that no more interrupts will be issued.
  *
- *             ide.c will then give higher priority to requests which
- *             originate from the other device, until will change rq_status
- *             to RQ_ACTIVE.
+ * 3. ATAPI Tape media access commands have immediate status with a delayed
+ * process. In case of a successful initiation of a media access packet command,
+ * the DSC bit will be set when the actual execution of the command is finished.
+ * Since the tape drive will not issue an interrupt, we have to poll for this
+ * event. In this case, we define the request as "low priority request" by
+ * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
+ * exit the driver.
  *
- *     4.      When the packet command is finished, it will be checked for errors.
+ * ide.c will then give higher priority to requests which originate from the
+ * other device, until will change rq_status to RQ_ACTIVE.
  *
- *     5.      In case an error was found, we queue a request sense packet
- *             command in front of the request queue and retry the operation
- *             up to IDETAPE_MAX_PC_RETRIES times.
+ * 4. When the packet command is finished, it will be checked for errors.
  *
- *     6.      In case no error was found, or we decided to give up and not
- *             to retry again, the callback function will be called and then
- *             we will handle the next request.
+ * 5. In case an error was found, we queue a request sense packet command in
+ * front of the request queue and retry the operation up to
+ * IDETAPE_MAX_PC_RETRIES times.
  *
+ * 6. In case no error was found, or we decided to give up and not to retry
+ * again, the callback function will be called and then we will handle the next
+ * request.
  */
 static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive)
 {
-       ide_hwif_t *hwif = drive->hwif;
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t *pc = tape->pc;
-       int retries = 100;
-       ide_startstop_t startstop;
-       u8 ireason;
-
-       if (ide_wait_stat(&startstop,drive,DRQ_STAT,BUSY_STAT,WAIT_READY)) {
-               printk(KERN_ERR "ide-tape: Strange, packet command initiated yet DRQ isn't asserted\n");
-               return startstop;
-       }
-       ireason = hwif->INB(IDE_IREASON_REG);
-       while (retries-- && ((ireason & CD) == 0 || (ireason & IO))) {
-               printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while issuing "
-                               "a packet command, retrying\n");
-               udelay(100);
-               ireason = hwif->INB(IDE_IREASON_REG);
-               if (retries == 0) {
-                       printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while "
-                                       "issuing a packet command, ignoring\n");
-                       ireason |= CD;
-                       ireason &= ~IO;
-               }
-       }
-       if ((ireason & CD) == 0 || (ireason & IO)) {
-               printk(KERN_ERR "ide-tape: (IO,CoD) != (0,1) while issuing "
-                               "a packet command\n");
-               return ide_do_reset(drive);
-       }
-       /* Set the interrupt routine */
-       ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
-#ifdef CONFIG_BLK_DEV_IDEDMA
-       /* Begin DMA, if necessary */
-       if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags))
-               hwif->dma_start(drive);
-#endif
-       /* Send the actual packet */
-       HWIF(drive)->atapi_output_bytes(drive, pc->c, 12);
-       return ide_started;
+
+       return ide_transfer_pc(drive, tape->pc, idetape_pc_intr,
+                              IDETAPE_WAIT_CMD, NULL);
 }
 
-static ide_startstop_t idetape_issue_packet_command (ide_drive_t *drive, idetape_pc_t *pc)
+static ide_startstop_t idetape_issue_pc(ide_drive_t *drive,
+               struct ide_atapi_pc *pc)
 {
-       ide_hwif_t *hwif = drive->hwif;
        idetape_tape_t *tape = drive->driver_data;
-       int dma_ok = 0;
-       u16 bcount;
 
        if (tape->pc->c[0] == REQUEST_SENSE &&
            pc->c[0] == REQUEST_SENSE) {
@@ -1366,13 +851,13 @@ static ide_startstop_t idetape_issue_packet_command (ide_drive_t *drive, idetape
        tape->pc = pc;
 
        if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
-           test_bit(PC_ABORT, &pc->flags)) {
+               (pc->flags & PC_FLAG_ABORT)) {
                /*
-                *      We will "abort" retrying a packet command in case
-                *      a legitimate error code was received (crossing a
-                *      filemark, or end of the media, for example).
+                * We will "abort" retrying a packet command in case legitimate
+                * error code was received (crossing a filemark, or end of the
+                * media, for example).
                 */
-               if (!test_bit(PC_ABORT, &pc->flags)) {
+               if (!(pc->flags & PC_FLAG_ABORT)) {
                        if (!(pc->c[0] == TEST_UNIT_READY &&
                              tape->sense_key == 2 && tape->asc == 4 &&
                             (tape->ascq == 1 || tape->ascq == 8))) {
@@ -1387,62 +872,25 @@ static ide_startstop_t idetape_issue_packet_command (ide_drive_t *drive, idetape
                        pc->error = IDETAPE_ERROR_GENERAL;
                }
                tape->failed_pc = NULL;
-               return pc->callback(drive);
+               drive->pc_callback(drive);
+               return ide_stopped;
        }
        debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]);
 
        pc->retries++;
-       /* We haven't transferred any data yet */
-       pc->actually_transferred = 0;
-       pc->current_position = pc->buffer;
-       /* Request to transfer the entire buffer at once */
-       bcount = pc->request_transfer;
-
-       if (test_and_clear_bit(PC_DMA_ERROR, &pc->flags)) {
-               printk(KERN_WARNING "ide-tape: DMA disabled, "
-                               "reverting to PIO\n");
-               ide_dma_off(drive);
-       }
-       if (test_bit(PC_DMA_RECOMMENDED, &pc->flags) && drive->using_dma)
-               dma_ok = !hwif->dma_setup(drive);
-
-       ide_pktcmd_tf_load(drive, IDE_TFLAG_NO_SELECT_MASK |
-                          IDE_TFLAG_OUT_DEVICE, bcount, dma_ok);
-
-       if (dma_ok)                     /* Will begin DMA later */
-               set_bit(PC_DMA_IN_PROGRESS, &pc->flags);
-       if (test_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags)) {
-               ide_execute_command(drive, WIN_PACKETCMD, &idetape_transfer_pc,
-                                   IDETAPE_WAIT_CMD, NULL);
-               return ide_started;
-       } else {
-               hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
-               return idetape_transfer_pc(drive);
-       }
-}
 
-/*
- *     General packet command callback function.
- */
-static ide_startstop_t idetape_pc_callback (ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-
-       debug_log(DBG_PROCS, "Enter %s\n", __func__);
-
-       idetape_end_request(drive, tape->pc->error ? 0 : 1, 0);
-       return ide_stopped;
+       return ide_issue_pc(drive, pc, idetape_transfer_pc,
+                           IDETAPE_WAIT_CMD, NULL);
 }
 
-/*
- *     A mode sense command is used to "sense" tape parameters.
- */
-static void idetape_create_mode_sense_cmd (idetape_pc_t *pc, u8 page_code)
+/* A mode sense command is used to "sense" tape parameters. */
+static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
 {
        idetape_init_pc(pc);
        pc->c[0] = MODE_SENSE;
        if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
-               pc->c[1] = 8;   /* DBD = 1 - Don't return block descriptors */
+               /* DBD = 1 - Don't return block descriptors */
+               pc->c[1] = 8;
        pc->c[2] = page_code;
        /*
         * Changed pc->c[3] to 0 (255 will at best return unused info).
@@ -1452,69 +900,24 @@ static void idetape_create_mode_sense_cmd (idetape_pc_t *pc, u8 page_code)
         * and return an error when 255 is used.
         */
        pc->c[3] = 0;
-       pc->c[4] = 255;         /* (We will just discard data in that case) */
+       /* We will just discard data in that case */
+       pc->c[4] = 255;
        if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
-               pc->request_transfer = 12;
+               pc->req_xfer = 12;
        else if (page_code == IDETAPE_CAPABILITIES_PAGE)
-               pc->request_transfer = 24;
+               pc->req_xfer = 24;
        else
-               pc->request_transfer = 50;
-       pc->callback = &idetape_pc_callback;
+               pc->req_xfer = 50;
 }
 
-static void idetape_calculate_speeds(ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-
-       if (time_after(jiffies, tape->controlled_pipeline_head_time + 120 * HZ)) {
-               tape->controlled_previous_pipeline_head = tape->controlled_last_pipeline_head;
-               tape->controlled_previous_head_time = tape->controlled_pipeline_head_time;
-               tape->controlled_last_pipeline_head = tape->pipeline_head;
-               tape->controlled_pipeline_head_time = jiffies;
-       }
-       if (time_after(jiffies, tape->controlled_pipeline_head_time + 60 * HZ))
-               tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_last_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_pipeline_head_time);
-       else if (time_after(jiffies, tape->controlled_previous_head_time))
-               tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_previous_head_time);
-
-       if (tape->nr_pending_stages < tape->max_stages /*- 1 */) {
-               /* -1 for read mode error recovery */
-               if (time_after(jiffies, tape->uncontrolled_previous_head_time + 10 * HZ)) {
-                       tape->uncontrolled_pipeline_head_time = jiffies;
-                       tape->uncontrolled_pipeline_head_speed = (tape->pipeline_head - tape->uncontrolled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->uncontrolled_previous_head_time);
-               }
-       } else {
-               tape->uncontrolled_previous_head_time = jiffies;
-               tape->uncontrolled_previous_pipeline_head = tape->pipeline_head;
-               if (time_after(jiffies, tape->uncontrolled_pipeline_head_time + 30 * HZ)) {
-                       tape->uncontrolled_pipeline_head_time = jiffies;
-               }
-       }
-       tape->pipeline_head_speed = max(tape->uncontrolled_pipeline_head_speed, tape->controlled_pipeline_head_speed);
-
-       if (tape->speed_control == 1) {
-               if (tape->nr_pending_stages >= tape->max_stages / 2)
-                       tape->max_insert_speed = tape->pipeline_head_speed +
-                               (1100 - tape->pipeline_head_speed) * 2 * (tape->nr_pending_stages - tape->max_stages / 2) / tape->max_stages;
-               else
-                       tape->max_insert_speed = 500 +
-                               (tape->pipeline_head_speed - 500) * 2 * tape->nr_pending_stages / tape->max_stages;
-
-               if (tape->nr_pending_stages >= tape->max_stages * 99 / 100)
-                       tape->max_insert_speed = 5000;
-       } else
-               tape->max_insert_speed = tape->speed_control;
-
-       tape->max_insert_speed = max(tape->max_insert_speed, 500);
-}
-
-static ide_startstop_t idetape_media_access_finished (ide_drive_t *drive)
+static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
 {
+       ide_hwif_t *hwif = drive->hwif;
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t *pc = tape->pc;
+       struct ide_atapi_pc *pc = tape->pc;
        u8 stat;
 
-       stat = ide_read_status(drive);
+       stat = hwif->tp_ops->read_status(hwif);
 
        if (stat & SEEK_STAT) {
                if (stat & ERR_STAT) {
@@ -1523,115 +926,54 @@ static ide_startstop_t idetape_media_access_finished (ide_drive_t *drive)
                                printk(KERN_ERR "ide-tape: %s: I/O error, ",
                                                tape->name);
                        /* Retry operation */
-                       return idetape_retry_pc(drive);
+                       idetape_retry_pc(drive);
+                       return ide_stopped;
                }
                pc->error = 0;
-               if (tape->failed_pc == pc)
-                       tape->failed_pc = NULL;
        } else {
                pc->error = IDETAPE_ERROR_GENERAL;
                tape->failed_pc = NULL;
        }
-       return pc->callback(drive);
-}
-
-static ide_startstop_t idetape_rw_callback (ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       struct request *rq = HWGROUP(drive)->rq;
-       int blocks = tape->pc->actually_transferred / tape->blk_size;
-
-       tape->avg_size += blocks * tape->blk_size;
-       tape->insert_size += blocks * tape->blk_size;
-       if (tape->insert_size > 1024 * 1024)
-               tape->measure_insert_time = 1;
-       if (tape->measure_insert_time) {
-               tape->measure_insert_time = 0;
-               tape->insert_time = jiffies;
-               tape->insert_size = 0;
-       }
-       if (time_after(jiffies, tape->insert_time))
-               tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
-       if (time_after_eq(jiffies, tape->avg_time + HZ)) {
-               tape->avg_speed = tape->avg_size * HZ / (jiffies - tape->avg_time) / 1024;
-               tape->avg_size = 0;
-               tape->avg_time = jiffies;
-       }
-       debug_log(DBG_PROCS, "Enter %s\n", __func__);
-
-       tape->first_frame += blocks;
-       rq->current_nr_sectors -= blocks;
-
-       if (!tape->pc->error)
-               idetape_end_request(drive, 1, 0);
-       else
-               idetape_end_request(drive, tape->pc->error, 0);
+       drive->pc_callback(drive);
        return ide_stopped;
 }
 
-static void idetape_create_read_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
+static void ide_tape_create_rw_cmd(idetape_tape_t *tape,
+                                  struct ide_atapi_pc *pc, struct request *rq,
+                                  u8 opcode)
 {
+       struct idetape_bh *bh = (struct idetape_bh *)rq->special;
+       unsigned int length = rq->current_nr_sectors;
+
        idetape_init_pc(pc);
-       pc->c[0] = READ_6;
        put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
        pc->c[1] = 1;
-       pc->callback = &idetape_rw_callback;
        pc->bh = bh;
-       atomic_set(&bh->b_count, 0);
-       pc->buffer = NULL;
-       pc->buffer_size = length * tape->blk_size;
-       pc->request_transfer = pc->buffer_size;
-       if (pc->request_transfer == tape->stage_size)
-               set_bit(PC_DMA_RECOMMENDED, &pc->flags);
-}
-
-static void idetape_create_read_buffer_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
-{
-       int size = 32768;
-       struct idetape_bh *p = bh;
-
-       idetape_init_pc(pc);
-       pc->c[0] = READ_BUFFER;
-       pc->c[1] = IDETAPE_RETRIEVE_FAULTY_BLOCK;
-       pc->c[7] = size >> 8;
-       pc->c[8] = size & 0xff;
-       pc->callback = &idetape_pc_callback;
-       pc->bh = bh;
-       atomic_set(&bh->b_count, 0);
-       pc->buffer = NULL;
-       while (p) {
-               atomic_set(&p->b_count, 0);
-               p = p->b_reqnext;
+       pc->buf = NULL;
+       pc->buf_size = length * tape->blk_size;
+       pc->req_xfer = pc->buf_size;
+       if (pc->req_xfer == tape->buffer_size)
+               pc->flags |= PC_FLAG_DMA_OK;
+
+       if (opcode == READ_6) {
+               pc->c[0] = READ_6;
+               atomic_set(&bh->b_count, 0);
+       } else if (opcode == WRITE_6) {
+               pc->c[0] = WRITE_6;
+               pc->flags |= PC_FLAG_WRITING;
+               pc->b_data = bh->b_data;
+               pc->b_count = atomic_read(&bh->b_count);
        }
-       pc->request_transfer = pc->buffer_size = size;
-}
 
-static void idetape_create_write_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
-{
-       idetape_init_pc(pc);
-       pc->c[0] = WRITE_6;
-       put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
-       pc->c[1] = 1;
-       pc->callback = &idetape_rw_callback;
-       set_bit(PC_WRITING, &pc->flags);
-       pc->bh = bh;
-       pc->b_data = bh->b_data;
-       pc->b_count = atomic_read(&bh->b_count);
-       pc->buffer = NULL;
-       pc->buffer_size = length * tape->blk_size;
-       pc->request_transfer = pc->buffer_size;
-       if (pc->request_transfer == tape->stage_size)
-               set_bit(PC_DMA_RECOMMENDED, &pc->flags);
+       memcpy(rq->cmd, pc->c, 12);
 }
 
-/*
- * idetape_do_request is our request handling function.        
- */
 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
                                          struct request *rq, sector_t block)
 {
+       ide_hwif_t *hwif = drive->hwif;
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t *pc = NULL;
+       struct ide_atapi_pc *pc = NULL;
        struct request *postponed_rq = tape->postponed_rq;
        u8 stat;
 
@@ -1640,22 +982,19 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive,
                        rq->sector, rq->nr_sectors, rq->current_nr_sectors);
 
        if (!blk_special_request(rq)) {
-               /*
-                * We do not support buffer cache originated requests.
-                */
+               /* We do not support buffer cache originated requests. */
                printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
                        "request queue (%d)\n", drive->name, rq->cmd_type);
                ide_end_request(drive, 0, 0);
                return ide_stopped;
        }
 
-       /*
-        *      Retry a failed packet command
-        */
-       if (tape->failed_pc != NULL &&
-           tape->pc->c[0] == REQUEST_SENSE) {
-               return idetape_issue_packet_command(drive, tape->failed_pc);
+       /* Retry a failed packet command */
+       if (tape->failed_pc && tape->pc->c[0] == REQUEST_SENSE) {
+               pc = tape->failed_pc;
+               goto out;
        }
+
        if (postponed_rq != NULL)
                if (rq != postponed_rq) {
                        printk(KERN_ERR "ide-tape: ide-tape.c bug - "
@@ -1670,20 +1009,17 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive,
         * If the tape is still busy, postpone our request and service
         * the other device meanwhile.
         */
-       stat = ide_read_status(drive);
+       stat = hwif->tp_ops->read_status(hwif);
 
-       if (!drive->dsc_overlap && !(rq->cmd[0] & REQ_IDETAPE_PC2))
-               set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
+       if (!drive->dsc_overlap && !(rq->cmd[13] & REQ_IDETAPE_PC2))
+               set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
 
        if (drive->post_reset == 1) {
-               set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
+               set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
                drive->post_reset = 0;
        }
 
-       if (time_after(jiffies, tape->insert_time))
-               tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
-       idetape_calculate_speeds(drive);
-       if (!test_and_clear_bit(IDETAPE_IGNORE_DSC, &tape->flags) &&
+       if (!test_and_clear_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags) &&
            (stat & SEEK_STAT) == 0) {
                if (postponed_rq == NULL) {
                        tape->dsc_polling_start = jiffies;
@@ -1692,152 +1028,130 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive,
                } else if (time_after(jiffies, tape->dsc_timeout)) {
                        printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
                                tape->name);
-                       if (rq->cmd[0] & REQ_IDETAPE_PC2) {
+                       if (rq->cmd[13] & REQ_IDETAPE_PC2) {
                                idetape_media_access_finished(drive);
                                return ide_stopped;
                        } else {
                                return ide_do_reset(drive);
                        }
-               } else if (time_after(jiffies, tape->dsc_polling_start + IDETAPE_DSC_MA_THRESHOLD))
+               } else if (time_after(jiffies,
+                                       tape->dsc_polling_start +
+                                       IDETAPE_DSC_MA_THRESHOLD))
                        tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
                idetape_postpone_request(drive);
                return ide_stopped;
        }
-       if (rq->cmd[0] & REQ_IDETAPE_READ) {
-               tape->buffer_head++;
-               tape->postpone_cnt = 0;
-               pc = idetape_next_pc_storage(drive);
-               idetape_create_read_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
-               goto out;
-       }
-       if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
-               tape->buffer_head++;
-               tape->postpone_cnt = 0;
+       if (rq->cmd[13] & REQ_IDETAPE_READ) {
                pc = idetape_next_pc_storage(drive);
-               idetape_create_write_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
+               ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
                goto out;
        }
-       if (rq->cmd[0] & REQ_IDETAPE_READ_BUFFER) {
-               tape->postpone_cnt = 0;
+       if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
                pc = idetape_next_pc_storage(drive);
-               idetape_create_read_buffer_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
+               ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
                goto out;
        }
-       if (rq->cmd[0] & REQ_IDETAPE_PC1) {
-               pc = (idetape_pc_t *) rq->buffer;
-               rq->cmd[0] &= ~(REQ_IDETAPE_PC1);
-               rq->cmd[0] |= REQ_IDETAPE_PC2;
+       if (rq->cmd[13] & REQ_IDETAPE_PC1) {
+               pc = (struct ide_atapi_pc *) rq->buffer;
+               rq->cmd[13] &= ~(REQ_IDETAPE_PC1);
+               rq->cmd[13] |= REQ_IDETAPE_PC2;
                goto out;
        }
-       if (rq->cmd[0] & REQ_IDETAPE_PC2) {
+       if (rq->cmd[13] & REQ_IDETAPE_PC2) {
                idetape_media_access_finished(drive);
                return ide_stopped;
        }
        BUG();
-out:
-       return idetape_issue_packet_command(drive, pc);
-}
 
-/*
- *     Pipeline related functions
- */
-static inline int idetape_pipeline_active (idetape_tape_t *tape)
-{
-       int rc1, rc2;
-
-       rc1 = test_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
-       rc2 = (tape->active_data_rq != NULL);
-       return rc1;
+out:
+       return idetape_issue_pc(drive, pc);
 }
 
 /*
- *     idetape_kmalloc_stage uses __get_free_page to allocate a pipeline
- *     stage, along with all the necessary small buffers which together make
- *     a buffer of size tape->stage_size (or a bit more). We attempt to
- *     combine sequential pages as much as possible.
- *
- *     Returns a pointer to the new allocated stage, or NULL if we
- *     can't (or don't want to) allocate a stage.
+ * The function below uses __get_free_pages to allocate a data buffer of size
+ * tape->buffer_size (or a bit more). We attempt to combine sequential pages as
+ * much as possible.
  *
- *     Pipeline stages are optional and are used to increase performance.
- *     If we can't allocate them, we'll manage without them.
+ * It returns a pointer to the newly allocated buffer, or NULL in case of
+ * failure.
  */
-static idetape_stage_t *__idetape_kmalloc_stage (idetape_tape_t *tape, int full, int clear)
+static struct idetape_bh *ide_tape_kmalloc_buffer(idetape_tape_t *tape,
+                                                 int full, int clear)
 {
-       idetape_stage_t *stage;
-       struct idetape_bh *prev_bh, *bh;
-       int pages = tape->pages_per_stage;
+       struct idetape_bh *prev_bh, *bh, *merge_bh;
+       int pages = tape->pages_per_buffer;
+       unsigned int order, b_allocd;
        char *b_data = NULL;
 
-       if ((stage = kmalloc(sizeof (idetape_stage_t),GFP_KERNEL)) == NULL)
-               return NULL;
-       stage->next = NULL;
-
-       bh = stage->bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
+       merge_bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
+       bh = merge_bh;
        if (bh == NULL)
                goto abort;
-       bh->b_reqnext = NULL;
-       if ((bh->b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
+
+       order = fls(pages) - 1;
+       bh->b_data = (char *) __get_free_pages(GFP_KERNEL, order);
+       if (!bh->b_data)
                goto abort;
+       b_allocd = (1 << order) * PAGE_SIZE;
+       pages &= (order-1);
+
        if (clear)
-               memset(bh->b_data, 0, PAGE_SIZE);
-       bh->b_size = PAGE_SIZE;
+               memset(bh->b_data, 0, b_allocd);
+       bh->b_reqnext = NULL;
+       bh->b_size = b_allocd;
        atomic_set(&bh->b_count, full ? bh->b_size : 0);
 
-       while (--pages) {
-               if ((b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
+       while (pages) {
+               order = fls(pages) - 1;
+               b_data = (char *) __get_free_pages(GFP_KERNEL, order);
+               if (!b_data)
                        goto abort;
+               b_allocd = (1 << order) * PAGE_SIZE;
+
                if (clear)
-                       memset(b_data, 0, PAGE_SIZE);
-               if (bh->b_data == b_data + PAGE_SIZE) {
-                       bh->b_size += PAGE_SIZE;
-                       bh->b_data -= PAGE_SIZE;
+                       memset(b_data, 0, b_allocd);
+
+               /* newly allocated page frames below buffer header or ...*/
+               if (bh->b_data == b_data + b_allocd) {
+                       bh->b_size += b_allocd;
+                       bh->b_data -= b_allocd;
                        if (full)
-                               atomic_add(PAGE_SIZE, &bh->b_count);
+                               atomic_add(b_allocd, &bh->b_count);
                        continue;
                }
+               /* they are above the header */
                if (b_data == bh->b_data + bh->b_size) {
-                       bh->b_size += PAGE_SIZE;
+                       bh->b_size += b_allocd;
                        if (full)
-                               atomic_add(PAGE_SIZE, &bh->b_count);
+                               atomic_add(b_allocd, &bh->b_count);
                        continue;
                }
                prev_bh = bh;
-               if ((bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL)) == NULL) {
-                       free_page((unsigned long) b_data);
+               bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
+               if (!bh) {
+                       free_pages((unsigned long) b_data, order);
                        goto abort;
                }
                bh->b_reqnext = NULL;
                bh->b_data = b_data;
-               bh->b_size = PAGE_SIZE;
+               bh->b_size = b_allocd;
                atomic_set(&bh->b_count, full ? bh->b_size : 0);
                prev_bh->b_reqnext = bh;
+
+               pages &= (order-1);
        }
+
        bh->b_size -= tape->excess_bh_size;
        if (full)
                atomic_sub(tape->excess_bh_size, &bh->b_count);
-       return stage;
+       return merge_bh;
 abort:
-       __idetape_kfree_stage(stage);
+       ide_tape_kfree_buffer(tape);
        return NULL;
 }
 
-static idetape_stage_t *idetape_kmalloc_stage (idetape_tape_t *tape)
-{
-       idetape_stage_t *cache_stage = tape->cache_stage;
-
-       debug_log(DBG_PROCS, "Enter %s\n", __func__);
-
-       if (tape->nr_stages >= tape->max_stages)
-               return NULL;
-       if (cache_stage != NULL) {
-               tape->cache_stage = NULL;
-               return cache_stage;
-       }
-       return __idetape_kmalloc_stage(tape, 0, 0);
-}
-
-static int idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *stage, const char __user *buf, int n)
+static int idetape_copy_stage_from_user(idetape_tape_t *tape,
+                                       const char __user *buf, int n)
 {
        struct idetape_bh *bh = tape->bh;
        int count;
@@ -1845,12 +1159,15 @@ static int idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *
 
        while (n) {
                if (bh == NULL) {
-                       printk(KERN_ERR "ide-tape: bh == NULL in "
-                               "idetape_copy_stage_from_user\n");
+                       printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
+                                       __func__);
                        return 1;
                }
-               count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), (unsigned int)n);
-               if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count))
+               count = min((unsigned int)
+                               (bh->b_size - atomic_read(&bh->b_count)),
+                               (unsigned int)n);
+               if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf,
+                               count))
                        ret = 1;
                n -= count;
                atomic_add(count, &bh->b_count);
@@ -1865,226 +1182,129 @@ static int idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *
        return ret;
 }
 
-static int idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n)
-{
-       struct idetape_bh *bh = tape->bh;
-       int count;
-       int ret = 0;
-
-       while (n) {
-               if (bh == NULL) {
-                       printk(KERN_ERR "ide-tape: bh == NULL in "
-                               "idetape_copy_stage_to_user\n");
-                       return 1;
-               }
-               count = min(tape->b_count, n);
-               if  (copy_to_user(buf, tape->b_data, count))
-                       ret = 1;
-               n -= count;
-               tape->b_data += count;
-               tape->b_count -= count;
-               buf += count;
-               if (!tape->b_count) {
-                       tape->bh = bh = bh->b_reqnext;
-                       if (bh) {
-                               tape->b_data = bh->b_data;
-                               tape->b_count = atomic_read(&bh->b_count);
-                       }
-               }
-       }
-       return ret;
-}
-
-static void idetape_init_merge_stage (idetape_tape_t *tape)
-{
-       struct idetape_bh *bh = tape->merge_stage->bh;
-       
-       tape->bh = bh;
-       if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
-               atomic_set(&bh->b_count, 0);
-       else {
-               tape->b_data = bh->b_data;
-               tape->b_count = atomic_read(&bh->b_count);
-       }
-}
-
-static void idetape_switch_buffers (idetape_tape_t *tape, idetape_stage_t *stage)
-{
-       struct idetape_bh *tmp;
-
-       tmp = stage->bh;
-       stage->bh = tape->merge_stage->bh;
-       tape->merge_stage->bh = tmp;
-       idetape_init_merge_stage(tape);
-}
-
-/*
- *     idetape_add_stage_tail adds a new stage at the end of the pipeline.
- */
-static void idetape_add_stage_tail (ide_drive_t *drive,idetape_stage_t *stage)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       unsigned long flags;
-
-       debug_log(DBG_PROCS, "Enter %s\n", __func__);
-
-       spin_lock_irqsave(&tape->lock, flags);
-       stage->next = NULL;
-       if (tape->last_stage != NULL)
-               tape->last_stage->next=stage;
-       else
-               tape->first_stage = tape->next_stage=stage;
-       tape->last_stage = stage;
-       if (tape->next_stage == NULL)
-               tape->next_stage = tape->last_stage;
-       tape->nr_stages++;
-       tape->nr_pending_stages++;
-       spin_unlock_irqrestore(&tape->lock, flags);
-}
-
-/*
- *     idetape_wait_for_request installs a completion in a pending request
- *     and sleeps until it is serviced.
- *
- *     The caller should ensure that the request will not be serviced
- *     before we install the completion (usually by disabling interrupts).
- */
-static void idetape_wait_for_request (ide_drive_t *drive, struct request *rq)
+static int idetape_copy_stage_to_user(idetape_tape_t *tape, char __user *buf,
+                                     int n)
 {
-       DECLARE_COMPLETION_ONSTACK(wait);
-       idetape_tape_t *tape = drive->driver_data;
+       struct idetape_bh *bh = tape->bh;
+       int count;
+       int ret = 0;
 
-       if (rq == NULL || !blk_special_request(rq)) {
-               printk (KERN_ERR "ide-tape: bug: Trying to sleep on non-valid request\n");
-               return;
+       while (n) {
+               if (bh == NULL) {
+                       printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
+                                       __func__);
+                       return 1;
+               }
+               count = min(tape->b_count, n);
+               if  (copy_to_user(buf, tape->b_data, count))
+                       ret = 1;
+               n -= count;
+               tape->b_data += count;
+               tape->b_count -= count;
+               buf += count;
+               if (!tape->b_count) {
+                       bh = bh->b_reqnext;
+                       tape->bh = bh;
+                       if (bh) {
+                               tape->b_data = bh->b_data;
+                               tape->b_count = atomic_read(&bh->b_count);
+                       }
+               }
        }
-       rq->end_io_data = &wait;
-       rq->end_io = blk_end_sync_rq;
-       spin_unlock_irq(&tape->lock);
-       wait_for_completion(&wait);
-       /* The stage and its struct request have been deallocated */
-       spin_lock_irq(&tape->lock);
+       return ret;
 }
 
-static ide_startstop_t idetape_read_position_callback(ide_drive_t *drive)
+static void idetape_init_merge_buffer(idetape_tape_t *tape)
 {
-       idetape_tape_t *tape = drive->driver_data;
-       u8 *readpos = tape->pc->buffer;
-
-       debug_log(DBG_PROCS, "Enter %s\n", __func__);
-
-       if (!tape->pc->error) {
-               debug_log(DBG_SENSE, "BOP - %s\n",
-                               (readpos[0] & 0x80) ? "Yes" : "No");
-               debug_log(DBG_SENSE, "EOP - %s\n",
-                               (readpos[0] & 0x40) ? "Yes" : "No");
+       struct idetape_bh *bh = tape->merge_bh;
+       tape->bh = tape->merge_bh;
 
-               if (readpos[0] & 0x4) {
-                       printk(KERN_INFO "ide-tape: Block location is unknown"
-                                        "to the tape\n");
-                       clear_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
-                       idetape_end_request(drive, 0, 0);
-               } else {
-                       debug_log(DBG_SENSE, "Block Location - %u\n",
-                                       be32_to_cpu(*(u32 *)&readpos[4]));
-
-                       tape->partition = readpos[1];
-                       tape->first_frame =
-                               be32_to_cpu(*(u32 *)&readpos[4]);
-                       set_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
-                       idetape_end_request(drive, 1, 0);
-               }
-       } else {
-               idetape_end_request(drive, 0, 0);
+       if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
+               atomic_set(&bh->b_count, 0);
+       else {
+               tape->b_data = bh->b_data;
+               tape->b_count = atomic_read(&bh->b_count);
        }
-       return ide_stopped;
 }
 
 /*
- *     idetape_create_write_filemark_cmd will:
- *
- *             1.      Write a filemark if write_filemark=1.
- *             2.      Flush the device buffers without writing a filemark
- *                     if write_filemark=0.
- *
+ * Write a filemark if write_filemark=1. Flush the device buffers without
+ * writing a filemark otherwise.
  */
-static void idetape_create_write_filemark_cmd (ide_drive_t *drive, idetape_pc_t *pc,int write_filemark)
+static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
+               struct ide_atapi_pc *pc, int write_filemark)
 {
        idetape_init_pc(pc);
        pc->c[0] = WRITE_FILEMARKS;
        pc->c[4] = write_filemark;
-       set_bit(PC_WAIT_FOR_DSC, &pc->flags);
-       pc->callback = &idetape_pc_callback;
+       pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 }
 
-static void idetape_create_test_unit_ready_cmd(idetape_pc_t *pc)
+static void idetape_create_test_unit_ready_cmd(struct ide_atapi_pc *pc)
 {
        idetape_init_pc(pc);
        pc->c[0] = TEST_UNIT_READY;
-       pc->callback = &idetape_pc_callback;
 }
 
 /*
- *     idetape_queue_pc_tail is based on the following functions:
- *
- *     ide_do_drive_cmd from ide.c
- *     cdrom_queue_request and cdrom_queue_packet_command from ide-cd.c
- *
- *     We add a special packet command request to the tail of the request
- *     queue, and wait for it to be serviced.
+ * We add a special packet command request to the tail of the request queue, and
+ * wait for it to be serviced. This is not to be called from within the request
+ * handling part of the driver! We allocate here data on the stack and it is
+ * valid until the request is finished. This is not the case for the bottom part
+ * of the driver, where we are always leaving the functions to wait for an
+ * interrupt or a timer event.
  *
- *     This is not to be called from within the request handling part
- *     of the driver ! We allocate here data in the stack, and it is valid
- *     until the request is finished. This is not the case for the bottom
- *     part of the driver, where we are always leaving the functions to wait
- *     for an interrupt or a timer event.
- *
- *     From the bottom part of the driver, we should allocate safe memory
- *     using idetape_next_pc_storage and idetape_next_rq_storage, and add
- *     the request to the request list without waiting for it to be serviced !
- *     In that case, we usually use idetape_queue_pc_head.
+ * From the bottom part of the driver, we should allocate safe memory using
+ * idetape_next_pc_storage() and ide_tape_next_rq_storage(), and add the request
+ * to the request list without waiting for it to be serviced! In that case, we
+ * usually use idetape_queue_pc_head().
  */
-static int __idetape_queue_pc_tail (ide_drive_t *drive, idetape_pc_t *pc)
+static int idetape_queue_pc_tail(ide_drive_t *drive, struct ide_atapi_pc *pc)
 {
        struct ide_tape_obj *tape = drive->driver_data;
-       struct request rq;
+       struct request *rq;
+       int error;
 
-       idetape_init_rq(&rq, REQ_IDETAPE_PC1);
-       rq.buffer = (char *) pc;
-       rq.rq_disk = tape->disk;
-       return ide_do_drive_cmd(drive, &rq, ide_wait);
+       rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
+       rq->cmd_type = REQ_TYPE_SPECIAL;
+       rq->cmd[13] = REQ_IDETAPE_PC1;
+       rq->buffer = (char *)pc;
+       memcpy(rq->cmd, pc->c, 12);
+       error = blk_execute_rq(drive->queue, tape->disk, rq, 0);
+       blk_put_request(rq);
+       return error;
 }
 
-static void idetape_create_load_unload_cmd (ide_drive_t *drive, idetape_pc_t *pc,int cmd)
+static void idetape_create_load_unload_cmd(ide_drive_t *drive,
+               struct ide_atapi_pc *pc, int cmd)
 {
        idetape_init_pc(pc);
        pc->c[0] = START_STOP;
        pc->c[4] = cmd;
-       set_bit(PC_WAIT_FOR_DSC, &pc->flags);
-       pc->callback = &idetape_pc_callback;
+       pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 }
 
 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        int load_attempted = 0;
 
-       /*
-        * Wait for the tape to become ready
-        */
-       set_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
+       /* Wait for the tape to become ready */
+       set_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
        timeout += jiffies;
        while (time_before(jiffies, timeout)) {
                idetape_create_test_unit_ready_cmd(&pc);
-               if (!__idetape_queue_pc_tail(drive, &pc))
+               if (!idetape_queue_pc_tail(drive, &pc))
                        return 0;
                if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
-                   || (tape->asc == 0x3A)) {   /* no media */
+                   || (tape->asc == 0x3A)) {
+                       /* no media */
                        if (load_attempted)
                                return -ENOMEDIUM;
-                       idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK);
-                       __idetape_queue_pc_tail(drive, &pc);
+                       idetape_create_load_unload_cmd(drive, &pc,
+                                                       IDETAPE_LU_LOAD_MASK);
+                       idetape_queue_pc_tail(drive, &pc);
                        load_attempted = 1;
                /* not about to be ready */
                } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
@@ -2095,35 +1315,30 @@ static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
        return -EIO;
 }
 
-static int idetape_queue_pc_tail (ide_drive_t *drive,idetape_pc_t *pc)
-{
-       return __idetape_queue_pc_tail(drive, pc);
-}
-
-static int idetape_flush_tape_buffers (ide_drive_t *drive)
+static int idetape_flush_tape_buffers(ide_drive_t *drive)
 {
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        int rc;
 
        idetape_create_write_filemark_cmd(drive, &pc, 0);
-       if ((rc = idetape_queue_pc_tail(drive, &pc)))
+       rc = idetape_queue_pc_tail(drive, &pc);
+       if (rc)
                return rc;
        idetape_wait_ready(drive, 60 * 5 * HZ);
        return 0;
 }
 
-static void idetape_create_read_position_cmd (idetape_pc_t *pc)
+static void idetape_create_read_position_cmd(struct ide_atapi_pc *pc)
 {
        idetape_init_pc(pc);
        pc->c[0] = READ_POSITION;
-       pc->request_transfer = 20;
-       pc->callback = &idetape_read_position_callback;
+       pc->req_xfer = 20;
 }
 
-static int idetape_read_position (ide_drive_t *drive)
+static int idetape_read_position(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        int position;
 
        debug_log(DBG_PROCS, "Enter %s\n", __func__);
@@ -2135,18 +1350,20 @@ static int idetape_read_position (ide_drive_t *drive)
        return position;
 }
 
-static void idetape_create_locate_cmd (ide_drive_t *drive, idetape_pc_t *pc, unsigned int block, u8 partition, int skip)
+static void idetape_create_locate_cmd(ide_drive_t *drive,
+               struct ide_atapi_pc *pc,
+               unsigned int block, u8 partition, int skip)
 {
        idetape_init_pc(pc);
        pc->c[0] = POSITION_TO_ELEMENT;
        pc->c[1] = 2;
        put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
        pc->c[8] = partition;
-       set_bit(PC_WAIT_FOR_DSC, &pc->flags);
-       pc->callback = &idetape_pc_callback;
+       pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 }
 
-static int idetape_create_prevent_cmd (ide_drive_t *drive, idetape_pc_t *pc, int prevent)
+static int idetape_create_prevent_cmd(ide_drive_t *drive,
+               struct ide_atapi_pc *pc, int prevent)
 {
        idetape_tape_t *tape = drive->driver_data;
 
@@ -2157,73 +1374,41 @@ static int idetape_create_prevent_cmd (ide_drive_t *drive, idetape_pc_t *pc, int
        idetape_init_pc(pc);
        pc->c[0] = ALLOW_MEDIUM_REMOVAL;
        pc->c[4] = prevent;
-       pc->callback = &idetape_pc_callback;
        return 1;
 }
 
-static int __idetape_discard_read_pipeline (ide_drive_t *drive)
+static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-       unsigned long flags;
-       int cnt;
 
        if (tape->chrdev_dir != IDETAPE_DIR_READ)
-               return 0;
+               return;
 
-       /* Remove merge stage. */
-       cnt = tape->merge_stage_size / tape->blk_size;
-       if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
-               ++cnt;          /* Filemarks count as 1 sector */
-       tape->merge_stage_size = 0;
-       if (tape->merge_stage != NULL) {
-               __idetape_kfree_stage(tape->merge_stage);
-               tape->merge_stage = NULL;
+       clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags);
+       tape->merge_bh_size = 0;
+       if (tape->merge_bh != NULL) {
+               ide_tape_kfree_buffer(tape);
+               tape->merge_bh = NULL;
        }
 
-       /* Clear pipeline flags. */
-       clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
        tape->chrdev_dir = IDETAPE_DIR_NONE;
-
-       /* Remove pipeline stages. */
-       if (tape->first_stage == NULL)
-               return 0;
-
-       spin_lock_irqsave(&tape->lock, flags);
-       tape->next_stage = NULL;
-       if (idetape_pipeline_active(tape))
-               idetape_wait_for_request(drive, tape->active_data_rq);
-       spin_unlock_irqrestore(&tape->lock, flags);
-
-       while (tape->first_stage != NULL) {
-               struct request *rq_ptr = &tape->first_stage->rq;
-
-               cnt += rq_ptr->nr_sectors - rq_ptr->current_nr_sectors; 
-               if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
-                       ++cnt;
-               idetape_remove_stage_head(drive);
-       }
-       tape->nr_pending_stages = 0;
-       tape->max_stages = tape->min_pipeline;
-       return cnt;
 }
 
 /*
- *     idetape_position_tape positions the tape to the requested block
- *     using the LOCATE packet command. A READ POSITION command is then
- *     issued to check where we are positioned.
- *
- *     Like all higher level operations, we queue the commands at the tail
- *     of the request queue and wait for their completion.
- *     
+ * Position the tape to the requested block using the LOCATE packet command.
+ * A READ POSITION command is then issued to check where we are positioned. Like
+ * all higher level operations, we queue the commands at the tail of the request
+ * queue and wait for their completion.
  */
-static int idetape_position_tape (ide_drive_t *drive, unsigned int block, u8 partition, int skip)
+static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
+               u8 partition, int skip)
 {
        idetape_tape_t *tape = drive->driver_data;
        int retval;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
 
        if (tape->chrdev_dir == IDETAPE_DIR_READ)
-               __idetape_discard_read_pipeline(drive);
+               __ide_tape_discard_merge_buffer(drive);
        idetape_wait_ready(drive, 60 * 5 * HZ);
        idetape_create_locate_cmd(drive, &pc, block, partition, skip);
        retval = idetape_queue_pc_tail(drive, &pc);
@@ -2234,238 +1419,127 @@ static int idetape_position_tape (ide_drive_t *drive, unsigned int block, u8 par
        return (idetape_queue_pc_tail(drive, &pc));
 }
 
-static void idetape_discard_read_pipeline (ide_drive_t *drive, int restore_position)
+static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
+                                         int restore_position)
 {
        idetape_tape_t *tape = drive->driver_data;
-       int cnt;
        int seek, position;
 
-       cnt = __idetape_discard_read_pipeline(drive);
+       __ide_tape_discard_merge_buffer(drive);
        if (restore_position) {
                position = idetape_read_position(drive);
-               seek = position > cnt ? position - cnt : 0;
+               seek = position > 0 ? position : 0;
                if (idetape_position_tape(drive, seek, 0, 0)) {
-                       printk(KERN_INFO "ide-tape: %s: position_tape failed in discard_pipeline()\n", tape->name);
+                       printk(KERN_INFO "ide-tape: %s: position_tape failed in"
+                                        " %s\n", tape->name, __func__);
                        return;
                }
        }
 }
 
 /*
- * idetape_queue_rw_tail generates a read/write request for the block
- * device interface and wait for it to be serviced.
+ * Generate a read/write request for the block device interface and wait for it
+ * to be serviced.
  */
-static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks, struct idetape_bh *bh)
+static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks,
+                                struct idetape_bh *bh)
 {
        idetape_tape_t *tape = drive->driver_data;
-       struct request rq;
+       struct request *rq;
+       int ret, errors;
 
        debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd);
 
-       if (idetape_pipeline_active(tape)) {
-               printk(KERN_ERR "ide-tape: bug: the pipeline is active in %s\n",
-                               __func__);
-               return (0);
-       }
+       rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
+       rq->cmd_type = REQ_TYPE_SPECIAL;
+       rq->cmd[13] = cmd;
+       rq->rq_disk = tape->disk;
+       rq->special = (void *)bh;
+       rq->sector = tape->first_frame;
+       rq->nr_sectors = blocks;
+       rq->current_nr_sectors = blocks;
+       blk_execute_rq(drive->queue, tape->disk, rq, 0);
 
-       idetape_init_rq(&rq, cmd);
-       rq.rq_disk = tape->disk;
-       rq.special = (void *)bh;
-       rq.sector = tape->first_frame;
-       rq.nr_sectors = rq.current_nr_sectors = blocks;
-       (void) ide_do_drive_cmd(drive, &rq, ide_wait);
+       errors = rq->errors;
+       ret = tape->blk_size * (blocks - rq->current_nr_sectors);
+       blk_put_request(rq);
 
        if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0)
                return 0;
 
-       if (tape->merge_stage)
-               idetape_init_merge_stage(tape);
-       if (rq.errors == IDETAPE_ERROR_GENERAL)
+       if (tape->merge_bh)
+               idetape_init_merge_buffer(tape);
+       if (errors == IDETAPE_ERROR_GENERAL)
                return -EIO;
-       return (tape->blk_size * (blocks-rq.current_nr_sectors));
-}
-
-/*
- *     idetape_insert_pipeline_into_queue is used to start servicing the
- *     pipeline stages, starting from tape->next_stage.
- */
-static void idetape_insert_pipeline_into_queue (ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-
-       if (tape->next_stage == NULL)
-               return;
-       if (!idetape_pipeline_active(tape)) {
-               set_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
-               idetape_activate_next_stage(drive);
-               (void) ide_do_drive_cmd(drive, tape->active_data_rq, ide_end);
-       }
+       return ret;
 }
 
-static void idetape_create_inquiry_cmd (idetape_pc_t *pc)
+static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
 {
        idetape_init_pc(pc);
        pc->c[0] = INQUIRY;
-       pc->c[4] = pc->request_transfer = 254;
-       pc->callback = &idetape_pc_callback;
+       pc->c[4] = 254;
+       pc->req_xfer = 254;
 }
 
-static void idetape_create_rewind_cmd (ide_drive_t *drive, idetape_pc_t *pc)
+static void idetape_create_rewind_cmd(ide_drive_t *drive,
+               struct ide_atapi_pc *pc)
 {
        idetape_init_pc(pc);
        pc->c[0] = REZERO_UNIT;
-       set_bit(PC_WAIT_FOR_DSC, &pc->flags);
-       pc->callback = &idetape_pc_callback;
+       pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 }
 
-static void idetape_create_erase_cmd (idetape_pc_t *pc)
+static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
 {
        idetape_init_pc(pc);
        pc->c[0] = ERASE;
        pc->c[1] = 1;
-       set_bit(PC_WAIT_FOR_DSC, &pc->flags);
-       pc->callback = &idetape_pc_callback;
+       pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 }
 
-static void idetape_create_space_cmd (idetape_pc_t *pc,int count, u8 cmd)
+static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
 {
        idetape_init_pc(pc);
        pc->c[0] = SPACE;
        put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
        pc->c[1] = cmd;
-       set_bit(PC_WAIT_FOR_DSC, &pc->flags);
-       pc->callback = &idetape_pc_callback;
-}
-
-static void idetape_wait_first_stage (ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       unsigned long flags;
-
-       if (tape->first_stage == NULL)
-               return;
-       spin_lock_irqsave(&tape->lock, flags);
-       if (tape->active_stage == tape->first_stage)
-               idetape_wait_for_request(drive, tape->active_data_rq);
-       spin_unlock_irqrestore(&tape->lock, flags);
+       pc->flags |= PC_FLAG_WAIT_FOR_DSC;
 }
 
-/*
- *     idetape_add_chrdev_write_request tries to add a character device
- *     originated write request to our pipeline. In case we don't succeed,
- *     we revert to non-pipelined operation mode for this request.
- *
- *     1.      Try to allocate a new pipeline stage.
- *     2.      If we can't, wait for more and more requests to be serviced
- *             and try again each time.
- *     3.      If we still can't allocate a stage, fallback to
- *             non-pipelined operation mode for this request.
- */
-static int idetape_add_chrdev_write_request (ide_drive_t *drive, int blocks)
+/* Queue up a character device originated write request. */
+static int idetape_add_chrdev_write_request(ide_drive_t *drive, int blocks)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_stage_t *new_stage;
-       unsigned long flags;
-       struct request *rq;
 
        debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
 
-       /*
-        *      Attempt to allocate a new stage.
-        *      Pay special attention to possible race conditions.
-        */
-       while ((new_stage = idetape_kmalloc_stage(tape)) == NULL) {
-               spin_lock_irqsave(&tape->lock, flags);
-               if (idetape_pipeline_active(tape)) {
-                       idetape_wait_for_request(drive, tape->active_data_rq);
-                       spin_unlock_irqrestore(&tape->lock, flags);
-               } else {
-                       spin_unlock_irqrestore(&tape->lock, flags);
-                       idetape_insert_pipeline_into_queue(drive);
-                       if (idetape_pipeline_active(tape))
-                               continue;
-                       /*
-                        *      Linux is short on memory. Fallback to
-                        *      non-pipelined operation mode for this request.
-                        */
-                       return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh);
-               }
-       }
-       rq = &new_stage->rq;
-       idetape_init_rq(rq, REQ_IDETAPE_WRITE);
-       /* Doesn't actually matter - We always assume sequential access */
-       rq->sector = tape->first_frame;
-       rq->nr_sectors = rq->current_nr_sectors = blocks;
-
-       idetape_switch_buffers(tape, new_stage);
-       idetape_add_stage_tail(drive, new_stage);
-       tape->pipeline_head++;
-       idetape_calculate_speeds(drive);
-
-       /*
-        *      Estimate whether the tape has stopped writing by checking
-        *      if our write pipeline is currently empty. If we are not
-        *      writing anymore, wait for the pipeline to be full enough
-        *      (90%) before starting to service requests, so that we will
-        *      be able to keep up with the higher speeds of the tape.
-        */
-       if (!idetape_pipeline_active(tape)) {
-               if (tape->nr_stages >= tape->max_stages * 9 / 10 ||
-                       tape->nr_stages >= tape->max_stages -
-                       tape->uncontrolled_pipeline_head_speed * 3 * 1024 /
-                       tape->blk_size) {
-                       tape->measure_insert_time = 1;
-                       tape->insert_time = jiffies;
-                       tape->insert_size = 0;
-                       tape->insert_speed = 0;
-                       idetape_insert_pipeline_into_queue(drive);
-               }
-       }
-       if (test_and_clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
-               /* Return a deferred error */
-               return -EIO;
-       return blocks;
-}
-
-/*
- *     idetape_wait_for_pipeline will wait until all pending pipeline
- *     requests are serviced. Typically called on device close.
- */
-static void idetape_wait_for_pipeline (ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       unsigned long flags;
-
-       while (tape->next_stage || idetape_pipeline_active(tape)) {
-               idetape_insert_pipeline_into_queue(drive);
-               spin_lock_irqsave(&tape->lock, flags);
-               if (idetape_pipeline_active(tape))
-                       idetape_wait_for_request(drive, tape->active_data_rq);
-               spin_unlock_irqrestore(&tape->lock, flags);
-       }
+       return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
+                                    blocks, tape->merge_bh);
 }
 
-static void idetape_empty_write_pipeline (ide_drive_t *drive)
+static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
        int blocks, min;
        struct idetape_bh *bh;
 
        if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
-               printk(KERN_ERR "ide-tape: bug: Trying to empty write pipeline, but we are not writing.\n");
+               printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
+                               " but we are not writing.\n");
                return;
        }
-       if (tape->merge_stage_size > tape->stage_size) {
+       if (tape->merge_bh_size > tape->buffer_size) {
                printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n");
-               tape->merge_stage_size = tape->stage_size;
+               tape->merge_bh_size = tape->buffer_size;
        }
-       if (tape->merge_stage_size) {
-               blocks = tape->merge_stage_size / tape->blk_size;
-               if (tape->merge_stage_size % tape->blk_size) {
+       if (tape->merge_bh_size) {
+               blocks = tape->merge_bh_size / tape->blk_size;
+               if (tape->merge_bh_size % tape->blk_size) {
                        unsigned int i;
 
                        blocks++;
-                       i = tape->blk_size - tape->merge_stage_size %
+                       i = tape->blk_size - tape->merge_bh_size %
                                tape->blk_size;
                        bh = tape->bh->b_reqnext;
                        while (bh) {
@@ -2475,238 +1549,122 @@ static void idetape_empty_write_pipeline (ide_drive_t *drive)
                        bh = tape->bh;
                        while (i) {
                                if (bh == NULL) {
-
-                                       printk(KERN_INFO "ide-tape: bug, bh NULL\n");
+                                       printk(KERN_INFO "ide-tape: bug,"
+                                                        " bh NULL\n");
                                        break;
                                }
-                               min = min(i, (unsigned int)(bh->b_size - atomic_read(&bh->b_count)));
-                               memset(bh->b_data + atomic_read(&bh->b_count), 0, min);
+                               min = min(i, (unsigned int)(bh->b_size -
+                                               atomic_read(&bh->b_count)));
+                               memset(bh->b_data + atomic_read(&bh->b_count),
+                                               0, min);
                                atomic_add(min, &bh->b_count);
                                i -= min;
                                bh = bh->b_reqnext;
                        }
                }
                (void) idetape_add_chrdev_write_request(drive, blocks);
-               tape->merge_stage_size = 0;
+               tape->merge_bh_size = 0;
        }
-       idetape_wait_for_pipeline(drive);
-       if (tape->merge_stage != NULL) {
-               __idetape_kfree_stage(tape->merge_stage);
-               tape->merge_stage = NULL;
+       if (tape->merge_bh != NULL) {
+               ide_tape_kfree_buffer(tape);
+               tape->merge_bh = NULL;
        }
-       clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
        tape->chrdev_dir = IDETAPE_DIR_NONE;
-
-       /*
-        *      On the next backup, perform the feedback loop again.
-        *      (I don't want to keep sense information between backups,
-        *       as some systems are constantly on, and the system load
-        *       can be totally different on the next backup).
-        */
-       tape->max_stages = tape->min_pipeline;
-       if (tape->first_stage != NULL ||
-           tape->next_stage != NULL ||
-           tape->last_stage != NULL ||
-           tape->nr_stages != 0) {
-               printk(KERN_ERR "ide-tape: ide-tape pipeline bug, "
-                       "first_stage %p, next_stage %p, "
-                       "last_stage %p, nr_stages %d\n",
-                       tape->first_stage, tape->next_stage,
-                       tape->last_stage, tape->nr_stages);
-       }
-}
-
-static void idetape_restart_speed_control (ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-
-       tape->restart_speed_control_req = 0;
-       tape->pipeline_head = 0;
-       tape->controlled_last_pipeline_head = 0;
-       tape->controlled_previous_pipeline_head = tape->uncontrolled_previous_pipeline_head = 0;
-       tape->pipeline_head_speed = tape->controlled_pipeline_head_speed = 5000;
-       tape->uncontrolled_pipeline_head_speed = 0;
-       tape->controlled_pipeline_head_time = tape->uncontrolled_pipeline_head_time = jiffies;
-       tape->controlled_previous_head_time = tape->uncontrolled_previous_head_time = jiffies;
 }
 
-static int idetape_initiate_read (ide_drive_t *drive, int max_stages)
+static int idetape_init_read(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_stage_t *new_stage;
-       struct request rq;
        int bytes_read;
-       u16 blocks = *(u16 *)&tape->caps[12];
 
        /* Initialize read operation */
        if (tape->chrdev_dir != IDETAPE_DIR_READ) {
                if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
-                       idetape_empty_write_pipeline(drive);
+                       ide_tape_flush_merge_buffer(drive);
                        idetape_flush_tape_buffers(drive);
                }
-               if (tape->merge_stage || tape->merge_stage_size) {
-                       printk (KERN_ERR "ide-tape: merge_stage_size should be 0 now\n");
-                       tape->merge_stage_size = 0;
+               if (tape->merge_bh || tape->merge_bh_size) {
+                       printk(KERN_ERR "ide-tape: merge_bh_size should be"
+                                        " 0 now\n");
+                       tape->merge_bh_size = 0;
                }
-               if ((tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0)) == NULL)
+               tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0);
+               if (!tape->merge_bh)
                        return -ENOMEM;
                tape->chrdev_dir = IDETAPE_DIR_READ;
 
                /*
-                *      Issue a read 0 command to ensure that DSC handshake
-                *      is switched from completion mode to buffer available
-                *      mode.
-                *      No point in issuing this if DSC overlap isn't supported,
-                *      some drives (Seagate STT3401A) will return an error.
+                * Issue a read 0 command to ensure that DSC handshake is
+                * switched from completion mode to buffer available mode.
+                * No point in issuing this if DSC overlap isn't supported, some
+                * drives (Seagate STT3401A) will return an error.
                 */
                if (drive->dsc_overlap) {
-                       bytes_read = idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, 0, tape->merge_stage->bh);
+                       bytes_read = idetape_queue_rw_tail(drive,
+                                                       REQ_IDETAPE_READ, 0,
+                                                       tape->merge_bh);
                        if (bytes_read < 0) {
-                               __idetape_kfree_stage(tape->merge_stage);
-                               tape->merge_stage = NULL;
+                               ide_tape_kfree_buffer(tape);
+                               tape->merge_bh = NULL;
                                tape->chrdev_dir = IDETAPE_DIR_NONE;
                                return bytes_read;
                        }
                }
        }
-       if (tape->restart_speed_control_req)
-               idetape_restart_speed_control(drive);
-       idetape_init_rq(&rq, REQ_IDETAPE_READ);
-       rq.sector = tape->first_frame;
-       rq.nr_sectors = rq.current_nr_sectors = blocks;
-       if (!test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags) &&
-           tape->nr_stages < max_stages) {
-               new_stage = idetape_kmalloc_stage(tape);
-               while (new_stage != NULL) {
-                       new_stage->rq = rq;
-                       idetape_add_stage_tail(drive, new_stage);
-                       if (tape->nr_stages >= max_stages)
-                               break;
-                       new_stage = idetape_kmalloc_stage(tape);
-               }
-       }
-       if (!idetape_pipeline_active(tape)) {
-               if (tape->nr_pending_stages >= 3 * max_stages / 4) {
-                       tape->measure_insert_time = 1;
-                       tape->insert_time = jiffies;
-                       tape->insert_size = 0;
-                       tape->insert_speed = 0;
-                       idetape_insert_pipeline_into_queue(drive);
-               }
-       }
+
        return 0;
 }
 
-/*
- *     idetape_add_chrdev_read_request is called from idetape_chrdev_read
- *     to service a character device read request and add read-ahead
- *     requests to our pipeline.
- */
-static int idetape_add_chrdev_read_request (ide_drive_t *drive,int blocks)
+/* called from idetape_chrdev_read() to service a chrdev read request. */
+static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks)
 {
        idetape_tape_t *tape = drive->driver_data;
-       unsigned long flags;
-       struct request *rq_ptr;
-       int bytes_read;
 
        debug_log(DBG_PROCS, "Enter %s, %d blocks\n", __func__, blocks);
 
-       /*
-        * If we are at a filemark, return a read length of 0
-        */
-       if (test_bit(IDETAPE_FILEMARK, &tape->flags))
+       /* If we are at a filemark, return a read length of 0 */
+       if (test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
                return 0;
 
-       /*
-        * Wait for the next block to be available at the head
-        * of the pipeline
-        */
-       idetape_initiate_read(drive, tape->max_stages);
-       if (tape->first_stage == NULL) {
-               if (test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
-                       return 0;
-               return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks,
-                                       tape->merge_stage->bh);
-       }
-       idetape_wait_first_stage(drive);
-       rq_ptr = &tape->first_stage->rq;
-       bytes_read = tape->blk_size * (rq_ptr->nr_sectors -
-                                       rq_ptr->current_nr_sectors);
-       rq_ptr->nr_sectors = rq_ptr->current_nr_sectors = 0;
-
+       idetape_init_read(drive);
 
-       if (rq_ptr->errors == IDETAPE_ERROR_EOD)
-               return 0;
-       else {
-               idetape_switch_buffers(tape, tape->first_stage);
-               if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
-                       set_bit(IDETAPE_FILEMARK, &tape->flags);
-               spin_lock_irqsave(&tape->lock, flags);
-               idetape_remove_stage_head(drive);
-               spin_unlock_irqrestore(&tape->lock, flags);
-               tape->pipeline_head++;
-               idetape_calculate_speeds(drive);
-       }
-       if (bytes_read > blocks * tape->blk_size) {
-               printk(KERN_ERR "ide-tape: bug: trying to return more bytes than requested\n");
-               bytes_read = blocks * tape->blk_size;
-       }
-       return (bytes_read);
+       return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks,
+                                    tape->merge_bh);
 }
 
-static void idetape_pad_zeros (ide_drive_t *drive, int bcount)
+static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
 {
        idetape_tape_t *tape = drive->driver_data;
        struct idetape_bh *bh;
        int blocks;
-       
+
        while (bcount) {
                unsigned int count;
 
-               bh = tape->merge_stage->bh;
-               count = min(tape->stage_size, bcount);
+               bh = tape->merge_bh;
+               count = min(tape->buffer_size, bcount);
                bcount -= count;
                blocks = count / tape->blk_size;
                while (count) {
-                       atomic_set(&bh->b_count, min(count, (unsigned int)bh->b_size));
+                       atomic_set(&bh->b_count,
+                                  min(count, (unsigned int)bh->b_size));
                        memset(bh->b_data, 0, atomic_read(&bh->b_count));
                        count -= atomic_read(&bh->b_count);
                        bh = bh->b_reqnext;
                }
-               idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh);
-       }
-}
-
-static int idetape_pipeline_size (ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       idetape_stage_t *stage;
-       struct request *rq;
-       int size = 0;
-
-       idetape_wait_for_pipeline(drive);
-       stage = tape->first_stage;
-       while (stage != NULL) {
-               rq = &stage->rq;
-               size += tape->blk_size * (rq->nr_sectors -
-                               rq->current_nr_sectors);
-               if (rq->errors == IDETAPE_ERROR_FILEMARK)
-                       size += tape->blk_size;
-               stage = stage->next;
+               idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks,
+                                     tape->merge_bh);
        }
-       size += tape->merge_stage_size;
-       return size;
 }
 
 /*
- *     Rewinds the tape to the Beginning Of the current Partition (BOP).
- *
- *     We currently support only one partition.
- */ 
-static int idetape_rewind_tape (ide_drive_t *drive)
+ * Rewinds the tape to the Beginning Of the current Partition (BOP). We
+ * currently support only one partition.
+ */
+static int idetape_rewind_tape(ide_drive_t *drive)
 {
        int retval;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        idetape_tape_t *tape;
        tape = drive->driver_data;
 
@@ -2724,14 +1682,9 @@ static int idetape_rewind_tape (ide_drive_t *drive)
        return 0;
 }
 
-/*
- *     Our special ide-tape ioctl's.
- *
- *     Currently there aren't any ioctl's.
- *     mtio.h compatible commands should be issued to the character device
- *     interface.
- */
-static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd, unsigned long arg)
+/* mtio.h compatible commands should be issued to the chrdev interface. */
+static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
+                               unsigned long arg)
 {
        idetape_tape_t *tape = drive->driver_data;
        void __user *argp = (void __user *)arg;
@@ -2745,39 +1698,29 @@ static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd, unsigned l
        debug_log(DBG_PROCS, "Enter %s\n", __func__);
 
        switch (cmd) {
-               case 0x0340:
-                       if (copy_from_user(&config, argp, sizeof(config)))
-                               return -EFAULT;
-                       tape->best_dsc_rw_freq = config.dsc_rw_frequency;
-                       tape->max_stages = config.nr_stages;
-                       break;
-               case 0x0350:
-                       config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
-                       config.nr_stages = tape->max_stages; 
-                       if (copy_to_user(argp, &config, sizeof(config)))
-                               return -EFAULT;
-                       break;
-               default:
-                       return -EIO;
+       case 0x0340:
+               if (copy_from_user(&config, argp, sizeof(config)))
+                       return -EFAULT;
+               tape->best_dsc_rw_freq = config.dsc_rw_frequency;
+               break;
+       case 0x0350:
+               config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
+               config.nr_stages = 1;
+               if (copy_to_user(argp, &config, sizeof(config)))
+                       return -EFAULT;
+               break;
+       default:
+               return -EIO;
        }
        return 0;
 }
 
-/*
- *     idetape_space_over_filemarks is now a bit more complicated than just
- *     passing the command to the tape since we may have crossed some
- *     filemarks during our pipelined read-ahead mode.
- *
- *     As a minor side effect, the pipeline enables us to support MTFSFM when
- *     the filemark is in our internal pipeline even if the tape doesn't
- *     support spacing over filemarks in the reverse direction.
- */
-static int idetape_space_over_filemarks (ide_drive_t *drive,short mt_op,int mt_count)
+static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
+                                       int mt_count)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t pc;
-       unsigned long flags;
-       int retval,count=0;
+       struct ide_atapi_pc pc;
+       int retval, count = 0;
        int sprev = !!(tape->caps[4] & 0x20);
 
        if (mt_count == 0)
@@ -2785,122 +1728,90 @@ static int idetape_space_over_filemarks (ide_drive_t *drive,short mt_op,int mt_c
        if (MTBSF == mt_op || MTBSFM == mt_op) {
                if (!sprev)
                        return -EIO;
-               mt_count = - mt_count;
+               mt_count = -mt_count;
        }
 
        if (tape->chrdev_dir == IDETAPE_DIR_READ) {
-               /*
-                *      We have a read-ahead buffer. Scan it for crossed
-                *      filemarks.
-                */
-               tape->merge_stage_size = 0;
-               if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
+               tape->merge_bh_size = 0;
+               if (test_and_clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags))
                        ++count;
-               while (tape->first_stage != NULL) {
-                       if (count == mt_count) {
-                               if (mt_op == MTFSFM)
-                                       set_bit(IDETAPE_FILEMARK, &tape->flags);
-                               return 0;
-                       }
-                       spin_lock_irqsave(&tape->lock, flags);
-                       if (tape->first_stage == tape->active_stage) {
-                               /*
-                                *      We have reached the active stage in the read pipeline.
-                                *      There is no point in allowing the drive to continue
-                                *      reading any farther, so we stop the pipeline.
-                                *
-                                *      This section should be moved to a separate subroutine,
-                                *      because a similar function is performed in
-                                *      __idetape_discard_read_pipeline(), for example.
-                                */
-                               tape->next_stage = NULL;
-                               spin_unlock_irqrestore(&tape->lock, flags);
-                               idetape_wait_first_stage(drive);
-                               tape->next_stage = tape->first_stage->next;
-                       } else
-                               spin_unlock_irqrestore(&tape->lock, flags);
-                       if (tape->first_stage->rq.errors == IDETAPE_ERROR_FILEMARK)
-                               ++count;
-                       idetape_remove_stage_head(drive);
-               }
-               idetape_discard_read_pipeline(drive, 0);
+               ide_tape_discard_merge_buffer(drive, 0);
        }
 
-       /*
-        *      The filemark was not found in our internal pipeline.
-        *      Now we can issue the space command.
-        */
        switch (mt_op) {
-               case MTFSF:
-               case MTBSF:
-                       idetape_create_space_cmd(&pc,mt_count-count,IDETAPE_SPACE_OVER_FILEMARK);
-                       return (idetape_queue_pc_tail(drive, &pc));
-               case MTFSFM:
-               case MTBSFM:
-                       if (!sprev)
-                               return (-EIO);
-                       retval = idetape_space_over_filemarks(drive, MTFSF, mt_count-count);
-                       if (retval) return (retval);
-                       count = (MTBSFM == mt_op ? 1 : -1);
-                       return (idetape_space_over_filemarks(drive, MTFSF, count));
-               default:
-                       printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",mt_op);
-                       return (-EIO);
+       case MTFSF:
+       case MTBSF:
+               idetape_create_space_cmd(&pc, mt_count - count,
+                                        IDETAPE_SPACE_OVER_FILEMARK);
+               return idetape_queue_pc_tail(drive, &pc);
+       case MTFSFM:
+       case MTBSFM:
+               if (!sprev)
+                       return -EIO;
+               retval = idetape_space_over_filemarks(drive, MTFSF,
+                                                     mt_count - count);
+               if (retval)
+                       return retval;
+               count = (MTBSFM == mt_op ? 1 : -1);
+               return idetape_space_over_filemarks(drive, MTFSF, count);
+       default:
+               printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
+                               mt_op);
+               return -EIO;
        }
 }
 
-
 /*
- *     Our character device read / write functions.
+ * Our character device read / write functions.
  *
- *     The tape is optimized to maximize throughput when it is transferring
- *     an integral number of the "continuous transfer limit", which is
- *     a parameter of the specific tape (26 KB on my particular tape).
- *      (32 kB for Onstream)
+ * The tape is optimized to maximize throughput when it is transferring an
+ * integral number of the "continuous transfer limit", which is a parameter of
+ * the specific tape (26kB on my particular tape, 32kB for Onstream).
  *
- *     As of version 1.3 of the driver, the character device provides an
- *     abstract continuous view of the media - any mix of block sizes (even 1
- *     byte) on the same backup/restore procedure is supported. The driver
- *     will internally convert the requests to the recommended transfer unit,
- *     so that an unmatch between the user's block size to the recommended
- *     size will only result in a (slightly) increased driver overhead, but
- *     will no longer hit performance.
- *      This is not applicable to Onstream.
+ * As of version 1.3 of the driver, the character device provides an abstract
+ * continuous view of the media - any mix of block sizes (even 1 byte) on the
+ * same backup/restore procedure is supported. The driver will internally
+ * convert the requests to the recommended transfer unit, so that an unmatch
+ * between the user's block size to the recommended size will only result in a
+ * (slightly) increased driver overhead, but will no longer hit performance.
+ * This is not applicable to Onstream.
  */
-static ssize_t idetape_chrdev_read (struct file *file, char __user *buf,
-                                   size_t count, loff_t *ppos)
+static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
+                                  size_t count, loff_t *ppos)
 {
        struct ide_tape_obj *tape = ide_tape_f(file);
        ide_drive_t *drive = tape->drive;
-       ssize_t bytes_read,temp, actually_read = 0, rc;
+       ssize_t bytes_read, temp, actually_read = 0, rc;
        ssize_t ret = 0;
        u16 ctl = *(u16 *)&tape->caps[12];
 
        debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
 
        if (tape->chrdev_dir != IDETAPE_DIR_READ) {
-               if (test_bit(IDETAPE_DETECT_BS, &tape->flags))
+               if (test_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags))
                        if (count > tape->blk_size &&
                            (count % tape->blk_size) == 0)
                                tape->user_bs_factor = count / tape->blk_size;
        }
-       if ((rc = idetape_initiate_read(drive, tape->max_stages)) < 0)
+       rc = idetape_init_read(drive);
+       if (rc < 0)
                return rc;
        if (count == 0)
                return (0);
-       if (tape->merge_stage_size) {
-               actually_read = min((unsigned int)(tape->merge_stage_size), (unsigned int)count);
-               if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, actually_read))
+       if (tape->merge_bh_size) {
+               actually_read = min((unsigned int)(tape->merge_bh_size),
+                                   (unsigned int)count);
+               if (idetape_copy_stage_to_user(tape, buf, actually_read))
                        ret = -EFAULT;
                buf += actually_read;
-               tape->merge_stage_size -= actually_read;
+               tape->merge_bh_size -= actually_read;
                count -= actually_read;
        }
-       while (count >= tape->stage_size) {
+       while (count >= tape->buffer_size) {
                bytes_read = idetape_add_chrdev_read_request(drive, ctl);
                if (bytes_read <= 0)
                        goto finish;
-               if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, bytes_read))
+               if (idetape_copy_stage_to_user(tape, buf, bytes_read))
                        ret = -EFAULT;
                buf += bytes_read;
                count -= bytes_read;
@@ -2911,23 +1822,23 @@ static ssize_t idetape_chrdev_read (struct file *file, char __user *buf,
                if (bytes_read <= 0)
                        goto finish;
                temp = min((unsigned long)count, (unsigned long)bytes_read);
-               if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, temp))
+               if (idetape_copy_stage_to_user(tape, buf, temp))
                        ret = -EFAULT;
                actually_read += temp;
-               tape->merge_stage_size = bytes_read-temp;
+               tape->merge_bh_size = bytes_read-temp;
        }
 finish:
-       if (!actually_read && test_bit(IDETAPE_FILEMARK, &tape->flags)) {
+       if (!actually_read && test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags)) {
                debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name);
 
                idetape_space_over_filemarks(drive, MTFSF, 1);
                return 0;
        }
 
-       return (ret) ? ret : actually_read;
+       return ret ? ret : actually_read;
 }
 
-static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf,
+static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
                                     size_t count, loff_t *ppos)
 {
        struct ide_tape_obj *tape = ide_tape_f(file);
@@ -2945,29 +1856,31 @@ static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf,
        /* Initialize write operation */
        if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
                if (tape->chrdev_dir == IDETAPE_DIR_READ)
-                       idetape_discard_read_pipeline(drive, 1);
-               if (tape->merge_stage || tape->merge_stage_size) {
-                       printk(KERN_ERR "ide-tape: merge_stage_size "
+                       ide_tape_discard_merge_buffer(drive, 1);
+               if (tape->merge_bh || tape->merge_bh_size) {
+                       printk(KERN_ERR "ide-tape: merge_bh_size "
                                "should be 0 now\n");
-                       tape->merge_stage_size = 0;
+                       tape->merge_bh_size = 0;
                }
-               if ((tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0)) == NULL)
+               tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0);
+               if (!tape->merge_bh)
                        return -ENOMEM;
                tape->chrdev_dir = IDETAPE_DIR_WRITE;
-               idetape_init_merge_stage(tape);
+               idetape_init_merge_buffer(tape);
 
                /*
-                *      Issue a write 0 command to ensure that DSC handshake
-                *      is switched from completion mode to buffer available
-                *      mode.
-                *      No point in issuing this if DSC overlap isn't supported,
-                *      some drives (Seagate STT3401A) will return an error.
+                * Issue a write 0 command to ensure that DSC handshake is
+                * switched from completion mode to buffer available mode. No
+                * point in issuing this if DSC overlap isn't supported, some
+                * drives (Seagate STT3401A) will return an error.
                 */
                if (drive->dsc_overlap) {
-                       ssize_t retval = idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh);
+                       ssize_t retval = idetape_queue_rw_tail(drive,
+                                                       REQ_IDETAPE_WRITE, 0,
+                                                       tape->merge_bh);
                        if (retval < 0) {
-                               __idetape_kfree_stage(tape->merge_stage);
-                               tape->merge_stage = NULL;
+                               ide_tape_kfree_buffer(tape);
+                               tape->merge_bh = NULL;
                                tape->chrdev_dir = IDETAPE_DIR_NONE;
                                return retval;
                        }
@@ -2975,51 +1888,51 @@ static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf,
        }
        if (count == 0)
                return (0);
-       if (tape->restart_speed_control_req)
-               idetape_restart_speed_control(drive);
-       if (tape->merge_stage_size) {
-               if (tape->merge_stage_size >= tape->stage_size) {
-                       printk(KERN_ERR "ide-tape: bug: merge buffer too big\n");
-                       tape->merge_stage_size = 0;
+       if (tape->merge_bh_size) {
+               if (tape->merge_bh_size >= tape->buffer_size) {
+                       printk(KERN_ERR "ide-tape: bug: merge buf too big\n");
+                       tape->merge_bh_size = 0;
                }
-               actually_written = min((unsigned int)(tape->stage_size - tape->merge_stage_size), (unsigned int)count);
-               if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, actually_written))
+               actually_written = min((unsigned int)
+                               (tape->buffer_size - tape->merge_bh_size),
+                               (unsigned int)count);
+               if (idetape_copy_stage_from_user(tape, buf, actually_written))
                                ret = -EFAULT;
                buf += actually_written;
-               tape->merge_stage_size += actually_written;
+               tape->merge_bh_size += actually_written;
                count -= actually_written;
 
-               if (tape->merge_stage_size == tape->stage_size) {
+               if (tape->merge_bh_size == tape->buffer_size) {
                        ssize_t retval;
-                       tape->merge_stage_size = 0;
+                       tape->merge_bh_size = 0;
                        retval = idetape_add_chrdev_write_request(drive, ctl);
                        if (retval <= 0)
                                return (retval);
                }
        }
-       while (count >= tape->stage_size) {
+       while (count >= tape->buffer_size) {
                ssize_t retval;
-               if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, tape->stage_size))
+               if (idetape_copy_stage_from_user(tape, buf, tape->buffer_size))
                        ret = -EFAULT;
-               buf += tape->stage_size;
-               count -= tape->stage_size;
+               buf += tape->buffer_size;
+               count -= tape->buffer_size;
                retval = idetape_add_chrdev_write_request(drive, ctl);
-               actually_written += tape->stage_size;
+               actually_written += tape->buffer_size;
                if (retval <= 0)
                        return (retval);
        }
        if (count) {
                actually_written += count;
-               if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, count))
+               if (idetape_copy_stage_from_user(tape, buf, count))
                        ret = -EFAULT;
-               tape->merge_stage_size += count;
+               tape->merge_bh_size += count;
        }
-       return (ret) ? ret : actually_written;
+       return ret ? ret : actually_written;
 }
 
-static int idetape_write_filemark (ide_drive_t *drive)
+static int idetape_write_filemark(ide_drive_t *drive)
 {
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
 
        /* Write a filemark */
        idetape_create_write_filemark_cmd(drive, &pc, 1);
@@ -3036,8 +1949,7 @@ static int idetape_write_filemark (ide_drive_t *drive)
  *
  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
- * usually not supported (it is supported in the rare case in which we crossed
- * the filemark during our read-ahead pipelined operation mode).
+ * usually not supported.
  *
  * The following commands are currently not supported:
  *
@@ -3047,113 +1959,117 @@ static int idetape_write_filemark (ide_drive_t *drive)
 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t pc;
-       int i,retval;
+       struct ide_atapi_pc pc;
+       int i, retval;
 
        debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n",
                        mt_op, mt_count);
-       /*
-        *      Commands which need our pipelined read-ahead stages.
-        */
+
        switch (mt_op) {
-               case MTFSF:
-               case MTFSFM:
-               case MTBSF:
-               case MTBSFM:
-                       if (!mt_count)
-                               return (0);
-                       return (idetape_space_over_filemarks(drive,mt_op,mt_count));
-               default:
-                       break;
+       case MTFSF:
+       case MTFSFM:
+       case MTBSF:
+       case MTBSFM:
+               if (!mt_count)
+                       return 0;
+               return idetape_space_over_filemarks(drive, mt_op, mt_count);
+       default:
+               break;
        }
+
        switch (mt_op) {
-               case MTWEOF:
-                       if (tape->write_prot)
-                               return -EACCES;
-                       idetape_discard_read_pipeline(drive, 1);
-                       for (i = 0; i < mt_count; i++) {
-                               retval = idetape_write_filemark(drive);
-                               if (retval)
-                                       return retval;
-                       }
-                       return (0);
-               case MTREW:
-                       idetape_discard_read_pipeline(drive, 0);
-                       if (idetape_rewind_tape(drive))
+       case MTWEOF:
+               if (tape->write_prot)
+                       return -EACCES;
+               ide_tape_discard_merge_buffer(drive, 1);
+               for (i = 0; i < mt_count; i++) {
+                       retval = idetape_write_filemark(drive);
+                       if (retval)
+                               return retval;
+               }
+               return 0;
+       case MTREW:
+               ide_tape_discard_merge_buffer(drive, 0);
+               if (idetape_rewind_tape(drive))
+                       return -EIO;
+               return 0;
+       case MTLOAD:
+               ide_tape_discard_merge_buffer(drive, 0);
+               idetape_create_load_unload_cmd(drive, &pc,
+                                              IDETAPE_LU_LOAD_MASK);
+               return idetape_queue_pc_tail(drive, &pc);
+       case MTUNLOAD:
+       case MTOFFL:
+               /*
+                * If door is locked, attempt to unlock before
+                * attempting to eject.
+                */
+               if (tape->door_locked) {
+                       if (idetape_create_prevent_cmd(drive, &pc, 0))
+                               if (!idetape_queue_pc_tail(drive, &pc))
+                                       tape->door_locked = DOOR_UNLOCKED;
+               }
+               ide_tape_discard_merge_buffer(drive, 0);
+               idetape_create_load_unload_cmd(drive, &pc,
+                                             !IDETAPE_LU_LOAD_MASK);
+               retval = idetape_queue_pc_tail(drive, &pc);
+               if (!retval)
+                       clear_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags);
+               return retval;
+       case MTNOP:
+               ide_tape_discard_merge_buffer(drive, 0);
+               return idetape_flush_tape_buffers(drive);
+       case MTRETEN:
+               ide_tape_discard_merge_buffer(drive, 0);
+               idetape_create_load_unload_cmd(drive, &pc,
+                       IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
+               return idetape_queue_pc_tail(drive, &pc);
+       case MTEOM:
+               idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
+               return idetape_queue_pc_tail(drive, &pc);
+       case MTERASE:
+               (void)idetape_rewind_tape(drive);
+               idetape_create_erase_cmd(&pc);
+               return idetape_queue_pc_tail(drive, &pc);
+       case MTSETBLK:
+               if (mt_count) {
+                       if (mt_count < tape->blk_size ||
+                           mt_count % tape->blk_size)
                                return -EIO;
+                       tape->user_bs_factor = mt_count / tape->blk_size;
+                       clear_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
+               } else
+                       set_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags);
+               return 0;
+       case MTSEEK:
+               ide_tape_discard_merge_buffer(drive, 0);
+               return idetape_position_tape(drive,
+                       mt_count * tape->user_bs_factor, tape->partition, 0);
+       case MTSETPART:
+               ide_tape_discard_merge_buffer(drive, 0);
+               return idetape_position_tape(drive, 0, mt_count, 0);
+       case MTFSR:
+       case MTBSR:
+       case MTLOCK:
+               if (!idetape_create_prevent_cmd(drive, &pc, 1))
                        return 0;
-               case MTLOAD:
-                       idetape_discard_read_pipeline(drive, 0);
-                       idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK);
-                       return (idetape_queue_pc_tail(drive, &pc));
-               case MTUNLOAD:
-               case MTOFFL:
-                       /*
-                        * If door is locked, attempt to unlock before
-                        * attempting to eject.
-                        */
-                       if (tape->door_locked) {
-                               if (idetape_create_prevent_cmd(drive, &pc, 0))
-                                       if (!idetape_queue_pc_tail(drive, &pc))
-                                               tape->door_locked = DOOR_UNLOCKED;
-                       }
-                       idetape_discard_read_pipeline(drive, 0);
-                       idetape_create_load_unload_cmd(drive, &pc,!IDETAPE_LU_LOAD_MASK);
-                       retval = idetape_queue_pc_tail(drive, &pc);
-                       if (!retval)
-                               clear_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
+               retval = idetape_queue_pc_tail(drive, &pc);
+               if (retval)
                        return retval;
-               case MTNOP:
-                       idetape_discard_read_pipeline(drive, 0);
-                       return (idetape_flush_tape_buffers(drive));
-               case MTRETEN:
-                       idetape_discard_read_pipeline(drive, 0);
-                       idetape_create_load_unload_cmd(drive, &pc,IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
-                       return (idetape_queue_pc_tail(drive, &pc));
-               case MTEOM:
-                       idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
-                       return (idetape_queue_pc_tail(drive, &pc));
-               case MTERASE:
-                       (void) idetape_rewind_tape(drive);
-                       idetape_create_erase_cmd(&pc);
-                       return (idetape_queue_pc_tail(drive, &pc));
-               case MTSETBLK:
-                       if (mt_count) {
-                               if (mt_count < tape->blk_size ||
-                                   mt_count % tape->blk_size)
-                                       return -EIO;
-                               tape->user_bs_factor = mt_count /
-                                                       tape->blk_size;
-                               clear_bit(IDETAPE_DETECT_BS, &tape->flags);
-                       } else
-                               set_bit(IDETAPE_DETECT_BS, &tape->flags);
-                       return 0;
-               case MTSEEK:
-                       idetape_discard_read_pipeline(drive, 0);
-                       return idetape_position_tape(drive, mt_count * tape->user_bs_factor, tape->partition, 0);
-               case MTSETPART:
-                       idetape_discard_read_pipeline(drive, 0);
-                       return (idetape_position_tape(drive, 0, mt_count, 0));
-               case MTFSR:
-               case MTBSR:
-               case MTLOCK:
-                       if (!idetape_create_prevent_cmd(drive, &pc, 1))
-                               return 0;
-                       retval = idetape_queue_pc_tail(drive, &pc);
-                       if (retval) return retval;
-                       tape->door_locked = DOOR_EXPLICITLY_LOCKED;
-                       return 0;
-               case MTUNLOCK:
-                       if (!idetape_create_prevent_cmd(drive, &pc, 0))
-                               return 0;
-                       retval = idetape_queue_pc_tail(drive, &pc);
-                       if (retval) return retval;
-                       tape->door_locked = DOOR_UNLOCKED;
+               tape->door_locked = DOOR_EXPLICITLY_LOCKED;
+               return 0;
+       case MTUNLOCK:
+               if (!idetape_create_prevent_cmd(drive, &pc, 0))
                        return 0;
-               default:
-                       printk(KERN_ERR "ide-tape: MTIO operation %d not "
-                               "supported\n", mt_op);
-                       return (-EIO);
+               retval = idetape_queue_pc_tail(drive, &pc);
+               if (retval)
+                       return retval;
+               tape->door_locked = DOOR_UNLOCKED;
+               return 0;
+       default:
+               printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",
+                               mt_op);
+               return -EIO;
        }
 }
 
@@ -3175,45 +2091,45 @@ static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
 
        debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
 
-       tape->restart_speed_control_req = 1;
        if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
-               idetape_empty_write_pipeline(drive);
+               ide_tape_flush_merge_buffer(drive);
                idetape_flush_tape_buffers(drive);
        }
        if (cmd == MTIOCGET || cmd == MTIOCPOS) {
-               block_offset = idetape_pipeline_size(drive) /
+               block_offset = tape->merge_bh_size /
                        (tape->blk_size * tape->user_bs_factor);
-               if ((position = idetape_read_position(drive)) < 0)
+               position = idetape_read_position(drive);
+               if (position < 0)
                        return -EIO;
        }
        switch (cmd) {
-               case MTIOCTOP:
-                       if (copy_from_user(&mtop, argp, sizeof (struct mtop)))
-                               return -EFAULT;
-                       return (idetape_mtioctop(drive,mtop.mt_op,mtop.mt_count));
-               case MTIOCGET:
-                       memset(&mtget, 0, sizeof (struct mtget));
-                       mtget.mt_type = MT_ISSCSI2;
-                       mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
-                       mtget.mt_dsreg =
-                               ((tape->blk_size * tape->user_bs_factor)
-                                << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
-
-                       if (tape->drv_write_prot) {
-                               mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
-                       }
-                       if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
-                               return -EFAULT;
-                       return 0;
-               case MTIOCPOS:
-                       mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
-                       if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
-                               return -EFAULT;
-                       return 0;
-               default:
-                       if (tape->chrdev_dir == IDETAPE_DIR_READ)
-                               idetape_discard_read_pipeline(drive, 1);
-                       return idetape_blkdev_ioctl(drive, cmd, arg);
+       case MTIOCTOP:
+               if (copy_from_user(&mtop, argp, sizeof(struct mtop)))
+                       return -EFAULT;
+               return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count);
+       case MTIOCGET:
+               memset(&mtget, 0, sizeof(struct mtget));
+               mtget.mt_type = MT_ISSCSI2;
+               mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
+               mtget.mt_dsreg =
+                       ((tape->blk_size * tape->user_bs_factor)
+                        << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
+
+               if (tape->drv_write_prot)
+                       mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
+
+               if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
+                       return -EFAULT;
+               return 0;
+       case MTIOCPOS:
+               mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
+               if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
+                       return -EFAULT;
+               return 0;
+       default:
+               if (tape->chrdev_dir == IDETAPE_DIR_READ)
+                       ide_tape_discard_merge_buffer(drive, 1);
+               return idetape_blkdev_ioctl(drive, cmd, arg);
        }
 }
 
@@ -3224,7 +2140,7 @@ static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
 
        idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
        if (idetape_queue_pc_tail(drive, &pc)) {
@@ -3236,29 +2152,29 @@ static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
                }
                return;
        }
-       tape->blk_size = (pc.buffer[4 + 5] << 16) +
-                               (pc.buffer[4 + 6] << 8)  +
-                                pc.buffer[4 + 7];
-       tape->drv_write_prot = (pc.buffer[2] & 0x80) >> 7;
+       tape->blk_size = (pc.buf[4 + 5] << 16) +
+                               (pc.buf[4 + 6] << 8)  +
+                                pc.buf[4 + 7];
+       tape->drv_write_prot = (pc.buf[2] & 0x80) >> 7;
 }
 
-/*
- *     Our character device open function.
- */
-static int idetape_chrdev_open (struct inode *inode, struct file *filp)
+static int idetape_chrdev_open(struct inode *inode, struct file *filp)
 {
        unsigned int minor = iminor(inode), i = minor & ~0xc0;
        ide_drive_t *drive;
        idetape_tape_t *tape;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        int retval;
 
        if (i >= MAX_HWIFS * MAX_DRIVES)
                return -ENXIO;
 
+       lock_kernel();
        tape = ide_tape_chrdev_get(i);
-       if (!tape)
+       if (!tape) {
+               unlock_kernel();
                return -ENXIO;
+       }
 
        debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
 
@@ -3273,25 +2189,22 @@ static int idetape_chrdev_open (struct inode *inode, struct file *filp)
 
        filp->private_data = tape;
 
-       if (test_and_set_bit(IDETAPE_BUSY, &tape->flags)) {
+       if (test_and_set_bit(IDE_AFLAG_BUSY, &drive->atapi_flags)) {
                retval = -EBUSY;
                goto out_put_tape;
        }
 
        retval = idetape_wait_ready(drive, 60 * HZ);
        if (retval) {
-               clear_bit(IDETAPE_BUSY, &tape->flags);
+               clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
                printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
                goto out_put_tape;
        }
 
        idetape_read_position(drive);
-       if (!test_bit(IDETAPE_ADDRESS_VALID, &tape->flags))
+       if (!test_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags))
                (void)idetape_rewind_tape(drive);
 
-       if (tape->chrdev_dir != IDETAPE_DIR_READ)
-               clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
-
        /* Read block size and write protect status from drive. */
        ide_tape_get_bsize_from_bdesc(drive);
 
@@ -3305,15 +2218,13 @@ static int idetape_chrdev_open (struct inode *inode, struct file *filp)
        if (tape->write_prot) {
                if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
                    (filp->f_flags & O_ACCMODE) == O_RDWR) {
-                       clear_bit(IDETAPE_BUSY, &tape->flags);
+                       clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
                        retval = -EROFS;
                        goto out_put_tape;
                }
        }
 
-       /*
-        * Lock the tape drive door so user can't eject.
-        */
+       /* Lock the tape drive door so user can't eject. */
        if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
                if (idetape_create_prevent_cmd(drive, &pc, 1)) {
                        if (!idetape_queue_pc_tail(drive, &pc)) {
@@ -3322,40 +2233,37 @@ static int idetape_chrdev_open (struct inode *inode, struct file *filp)
                        }
                }
        }
-       idetape_restart_speed_control(drive);
-       tape->restart_speed_control_req = 0;
+       unlock_kernel();
        return 0;
 
 out_put_tape:
        ide_tape_put(tape);
+       unlock_kernel();
        return retval;
 }
 
-static void idetape_write_release (ide_drive_t *drive, unsigned int minor)
+static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
 {
        idetape_tape_t *tape = drive->driver_data;
 
-       idetape_empty_write_pipeline(drive);
-       tape->merge_stage = __idetape_kmalloc_stage(tape, 1, 0);
-       if (tape->merge_stage != NULL) {
+       ide_tape_flush_merge_buffer(drive);
+       tape->merge_bh = ide_tape_kmalloc_buffer(tape, 1, 0);
+       if (tape->merge_bh != NULL) {
                idetape_pad_zeros(drive, tape->blk_size *
                                (tape->user_bs_factor - 1));
-               __idetape_kfree_stage(tape->merge_stage);
-               tape->merge_stage = NULL;
+               ide_tape_kfree_buffer(tape);
+               tape->merge_bh = NULL;
        }
        idetape_write_filemark(drive);
        idetape_flush_tape_buffers(drive);
        idetape_flush_tape_buffers(drive);
 }
 
-/*
- *     Our character device release function.
- */
-static int idetape_chrdev_release (struct inode *inode, struct file *filp)
+static int idetape_chrdev_release(struct inode *inode, struct file *filp)
 {
        struct ide_tape_obj *tape = ide_tape_f(filp);
        ide_drive_t *drive = tape->drive;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        unsigned int minor = iminor(inode);
 
        lock_kernel();
@@ -3367,15 +2275,10 @@ static int idetape_chrdev_release (struct inode *inode, struct file *filp)
                idetape_write_release(drive, minor);
        if (tape->chrdev_dir == IDETAPE_DIR_READ) {
                if (minor < 128)
-                       idetape_discard_read_pipeline(drive, 1);
-               else
-                       idetape_wait_for_pipeline(drive);
+                       ide_tape_discard_merge_buffer(drive, 1);
        }
-       if (tape->cache_stage != NULL) {
-               __idetape_kfree_stage(tape->cache_stage);
-               tape->cache_stage = NULL;
-       }
-       if (minor < 128 && test_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags))
+
+       if (minor < 128 && test_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags))
                (void) idetape_rewind_tape(drive);
        if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
                if (tape->door_locked == DOOR_LOCKED) {
@@ -3385,44 +2288,46 @@ static int idetape_chrdev_release (struct inode *inode, struct file *filp)
                        }
                }
        }
-       clear_bit(IDETAPE_BUSY, &tape->flags);
+       clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags);
        ide_tape_put(tape);
        unlock_kernel();
        return 0;
 }
 
 /*
- *     idetape_identify_device is called to check the contents of the
- *     ATAPI IDENTIFY command results. We return:
+ * check the contents of the ATAPI IDENTIFY command results. We return:
  *
- *     1       If the tape can be supported by us, based on the information
- *             we have so far.
+ * 1 - If the tape can be supported by us, based on the information we have so
+ * far.
  *
- *     0       If this tape driver is not currently supported by us.
+ * 0 - If this tape driver is not currently supported by us.
  */
-static int idetape_identify_device (ide_drive_t *drive)
+static int idetape_identify_device(ide_drive_t *drive)
 {
-       struct idetape_id_gcw gcw;
-       struct hd_driveid *id = drive->id;
+       u8 gcw[2], protocol, device_type, removable, packet_size;
 
        if (drive->id_read == 0)
                return 1;
 
-       *((unsigned short *) &gcw) = id->config;
+       *((unsigned short *) &gcw) = drive->id->config;
 
-       /* Check that we can support this device */
+       protocol        =   (gcw[1] & 0xC0) >> 6;
+       device_type     =    gcw[1] & 0x1F;
+       removable       = !!(gcw[0] & 0x80);
+       packet_size     =    gcw[0] & 0x3;
 
-       if (gcw.protocol != 2)
+       /* Check that we can support this device */
+       if (protocol != 2)
                printk(KERN_ERR "ide-tape: Protocol (0x%02x) is not ATAPI\n",
-                               gcw.protocol);
-       else if (gcw.device_type != 1)
+                               protocol);
+       else if (device_type != 1)
                printk(KERN_ERR "ide-tape: Device type (0x%02x) is not set "
-                               "to tape\n", gcw.device_type);
-       else if (!gcw.removable)
+                               "to tape\n", device_type);
+       else if (!removable)
                printk(KERN_ERR "ide-tape: The removable flag is not set\n");
-       else if (gcw.packet_size != 0) {
-               printk(KERN_ERR "ide-tape: Packet size (0x%02x) is not 12 "
-                               "bytes long\n", gcw.packet_size);
+       else if (packet_size != 0) {
+               printk(KERN_ERR "ide-tape: Packet size (0x%02x) is not 12"
+                               " bytes\n", packet_size);
        } else
                return 1;
        return 0;
@@ -3431,7 +2336,7 @@ static int idetape_identify_device (ide_drive_t *drive)
 static void idetape_get_inquiry_results(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        char fw_rev[6], vendor_id[10], product_id[18];
 
        idetape_create_inquiry_cmd(&pc);
@@ -3440,9 +2345,9 @@ static void idetape_get_inquiry_results(ide_drive_t *drive)
                                tape->name);
                return;
        }
-       memcpy(vendor_id, &pc.buffer[8], 8);
-       memcpy(product_id, &pc.buffer[16], 16);
-       memcpy(fw_rev, &pc.buffer[32], 4);
+       memcpy(vendor_id, &pc.buf[8], 8);
+       memcpy(product_id, &pc.buf[16], 16);
+       memcpy(fw_rev, &pc.buf[32], 4);
 
        ide_fixstring(vendor_id, 10, 0);
        ide_fixstring(product_id, 18, 0);
@@ -3456,10 +2361,10 @@ static void idetape_get_inquiry_results(ide_drive_t *drive)
  * Ask the tape about its various parameters. In particular, we will adjust our
  * data transfer buffer        size to the recommended value as returned by the tape.
  */
-static void idetape_get_mode_sense_results (ide_drive_t *drive)
+static void idetape_get_mode_sense_results(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        u8 *caps;
        u8 speed, max_speed;
 
@@ -3473,26 +2378,26 @@ static void idetape_get_mode_sense_results (ide_drive_t *drive)
                put_unaligned(6*52, (u16 *)&tape->caps[16]);
                return;
        }
-       caps = pc.buffer + 4 + pc.buffer[3];
+       caps = pc.buf + 4 + pc.buf[3];
 
        /* convert to host order and save for later use */
-       speed = be16_to_cpu(*(u16 *)&caps[14]);
-       max_speed = be16_to_cpu(*(u16 *)&caps[8]);
+       speed = be16_to_cpup((__be16 *)&caps[14]);
+       max_speed = be16_to_cpup((__be16 *)&caps[8]);
 
-       put_unaligned(max_speed, (u16 *)&caps[8]);
-       put_unaligned(be16_to_cpu(*(u16 *)&caps[12]), (u16 *)&caps[12]);
-       put_unaligned(speed, (u16 *)&caps[14]);
-       put_unaligned(be16_to_cpu(*(u16 *)&caps[16]), (u16 *)&caps[16]);
+       *(u16 *)&caps[8] = max_speed;
+       *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]);
+       *(u16 *)&caps[14] = speed;
+       *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]);
 
        if (!speed) {
                printk(KERN_INFO "ide-tape: %s: invalid tape speed "
                                "(assuming 650KB/sec)\n", drive->name);
-               put_unaligned(650, (u16 *)&caps[14]);
+               *(u16 *)&caps[14] = 650;
        }
        if (!max_speed) {
                printk(KERN_INFO "ide-tape: %s: invalid max_speed "
                                "(assuming 650KB/sec)\n", drive->name);
-               put_unaligned(650, (u16 *)&caps[8]);
+               *(u16 *)&caps[8] = 650;
        }
 
        memcpy(&tape->caps, caps, 20);
@@ -3503,31 +2408,23 @@ static void idetape_get_mode_sense_results (ide_drive_t *drive)
 }
 
 #ifdef CONFIG_IDE_PROC_FS
-static void idetape_add_settings (ide_drive_t *drive)
+static void idetape_add_settings(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
 
-/*
- *                     drive   setting name            read/write      data type       min                     max                     mul_factor                      div_factor      data pointer                            set function
- */
        ide_add_setting(drive, "buffer", SETTING_READ, TYPE_SHORT, 0, 0xffff,
                        1, 2, (u16 *)&tape->caps[16], NULL);
-       ide_add_setting(drive,  "pipeline_min",         SETTING_RW,     TYPE_INT,       1,                      0xffff,                 tape->stage_size / 1024,        1,              &tape->min_pipeline,                    NULL);
-       ide_add_setting(drive,  "pipeline",             SETTING_RW,     TYPE_INT,       1,                      0xffff,                 tape->stage_size / 1024,        1,              &tape->max_stages,                      NULL);
-       ide_add_setting(drive,  "pipeline_max",         SETTING_RW,     TYPE_INT,       1,                      0xffff,                 tape->stage_size / 1024,        1,              &tape->max_pipeline,                    NULL);
-       ide_add_setting(drive,  "pipeline_used",        SETTING_READ,   TYPE_INT,       0,                      0xffff,                 tape->stage_size / 1024,        1,              &tape->nr_stages,                       NULL);
-       ide_add_setting(drive,  "pipeline_pending",     SETTING_READ,   TYPE_INT,       0,                      0xffff,                 tape->stage_size / 1024,        1,              &tape->nr_pending_stages,               NULL);
        ide_add_setting(drive, "speed", SETTING_READ, TYPE_SHORT, 0, 0xffff,
                        1, 1, (u16 *)&tape->caps[14], NULL);
-       ide_add_setting(drive, "stage", SETTING_READ, TYPE_INT, 0, 0xffff, 1,
-                       1024, &tape->stage_size, NULL);
+       ide_add_setting(drive, "buffer_size", SETTING_READ, TYPE_INT, 0, 0xffff,
+                       1, 1024, &tape->buffer_size, NULL);
        ide_add_setting(drive, "tdsc", SETTING_RW, TYPE_INT, IDETAPE_DSC_RW_MIN,
                        IDETAPE_DSC_RW_MAX, 1000, HZ, &tape->best_dsc_rw_freq,
                        NULL);
-       ide_add_setting(drive,  "dsc_overlap",          SETTING_RW,     TYPE_BYTE,      0,                      1,                      1,                              1,              &drive->dsc_overlap,                    NULL);
-       ide_add_setting(drive,  "pipeline_head_speed_c",SETTING_READ,   TYPE_INT,       0,                      0xffff,                 1,                              1,              &tape->controlled_pipeline_head_speed,  NULL);
-       ide_add_setting(drive,  "pipeline_head_speed_u",SETTING_READ,   TYPE_INT,       0,                      0xffff,                 1,                              1,              &tape->uncontrolled_pipeline_head_speed,NULL);
-       ide_add_setting(drive,  "avg_speed",            SETTING_READ,   TYPE_INT,       0,                      0xffff,                 1,                              1,              &tape->avg_speed,                       NULL);
+       ide_add_setting(drive, "dsc_overlap", SETTING_RW, TYPE_BYTE, 0, 1, 1,
+                       1, &drive->dsc_overlap, NULL);
+       ide_add_setting(drive, "avg_speed", SETTING_READ, TYPE_INT, 0, 0xffff,
+                       1, 1, &tape->avg_speed, NULL);
        ide_add_setting(drive, "debug_mask", SETTING_RW, TYPE_INT, 0, 0xffff, 1,
                        1, &tape->debug_mask, NULL);
 }
@@ -3536,26 +2433,26 @@ static inline void idetape_add_settings(ide_drive_t *drive) { ; }
 #endif
 
 /*
- *     ide_setup is called to:
+ * The function below is called to:
  *
- *             1.      Initialize our various state variables.
- *             2.      Ask the tape for its capabilities.
- *             3.      Allocate a buffer which will be used for data
- *                     transfer. The buffer size is chosen based on
- *                     the recommendation which we received in step (2).
+ * 1. Initialize our various state variables.
+ * 2. Ask the tape for its capabilities.
+ * 3. Allocate a buffer which will be used for data transfer. The buffer size
+ * is chosen based on the recommendation which we received in step 2.
  *
- *     Note that at this point ide.c already assigned us an irq, so that
- *     we can queue requests here and wait for their completion.
+ * Note that at this point ide.c already assigned us an irq, so that we can
+ * queue requests here and wait for their completion.
  */
-static void idetape_setup (ide_drive_t *drive, idetape_tape_t *tape, int minor)
+static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
 {
-       unsigned long t1, tmid, tn, t;
+       unsigned long t;
        int speed;
-       struct idetape_id_gcw gcw;
-       int stage_size;
-       struct sysinfo si;
+       int buffer_size;
+       u8 gcw[2];
        u16 *ctl = (u16 *)&tape->caps[12];
 
+       drive->pc_callback = ide_tape_callback;
+
        spin_lock_init(&tape->lock);
        drive->dsc_overlap = 1;
        if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
@@ -3572,70 +2469,45 @@ static void idetape_setup (ide_drive_t *drive, idetape_tape_t *tape, int minor)
        tape->name[2] = '0' + minor;
        tape->chrdev_dir = IDETAPE_DIR_NONE;
        tape->pc = tape->pc_stack;
-       tape->max_insert_speed = 10000;
-       tape->speed_control = 1;
        *((unsigned short *) &gcw) = drive->id->config;
-       if (gcw.drq_type == 1)
-               set_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags);
 
-       tape->min_pipeline = tape->max_pipeline = tape->max_stages = 10;
-       
+       /* Command packet DRQ type */
+       if (((gcw[0] & 0x60) >> 5) == 1)
+               set_bit(IDE_AFLAG_DRQ_INTERRUPT, &drive->atapi_flags);
+
        idetape_get_inquiry_results(drive);
        idetape_get_mode_sense_results(drive);
        ide_tape_get_bsize_from_bdesc(drive);
        tape->user_bs_factor = 1;
-       tape->stage_size = *ctl * tape->blk_size;
-       while (tape->stage_size > 0xffff) {
+       tape->buffer_size = *ctl * tape->blk_size;
+       while (tape->buffer_size > 0xffff) {
                printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
                *ctl /= 2;
-               tape->stage_size = *ctl * tape->blk_size;
+               tape->buffer_size = *ctl * tape->blk_size;
        }
-       stage_size = tape->stage_size;
-       tape->pages_per_stage = stage_size / PAGE_SIZE;
-       if (stage_size % PAGE_SIZE) {
-               tape->pages_per_stage++;
-               tape->excess_bh_size = PAGE_SIZE - stage_size % PAGE_SIZE;
+       buffer_size = tape->buffer_size;
+       tape->pages_per_buffer = buffer_size / PAGE_SIZE;
+       if (buffer_size % PAGE_SIZE) {
+               tape->pages_per_buffer++;
+               tape->excess_bh_size = PAGE_SIZE - buffer_size % PAGE_SIZE;
        }
 
-       /* Select the "best" DSC read/write polling freq and pipeline size. */
+       /* select the "best" DSC read/write polling freq */
        speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
 
-       tape->max_stages = speed * 1000 * 10 / tape->stage_size;
-
-       /*
-        *      Limit memory use for pipeline to 10% of physical memory
-        */
-       si_meminfo(&si);
-       if (tape->max_stages * tape->stage_size > si.totalram * si.mem_unit / 10)
-               tape->max_stages = si.totalram * si.mem_unit / (10 * tape->stage_size);
-       tape->max_stages   = min(tape->max_stages, IDETAPE_MAX_PIPELINE_STAGES);
-       tape->min_pipeline = min(tape->max_stages, IDETAPE_MIN_PIPELINE_STAGES);
-       tape->max_pipeline = min(tape->max_stages * 2, IDETAPE_MAX_PIPELINE_STAGES);
-       if (tape->max_stages == 0)
-               tape->max_stages = tape->min_pipeline = tape->max_pipeline = 1;
-
-       t1 = (tape->stage_size * HZ) / (speed * 1000);
-       tmid = (*(u16 *)&tape->caps[16] * 32 * HZ) / (speed * 125);
-       tn = (IDETAPE_FIFO_THRESHOLD * tape->stage_size * HZ) / (speed * 1000);
-
-       if (tape->max_stages)
-               t = tn;
-       else
-               t = t1;
+       t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
 
        /*
-        *      Ensure that the number we got makes sense; limit
-        *      it within IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
+        * Ensure that the number we got makes sense; limit it within
+        * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
         */
-       tape->best_dsc_rw_freq = max_t(unsigned long,
-                               min_t(unsigned long, t, IDETAPE_DSC_RW_MAX),
-                               IDETAPE_DSC_RW_MIN);
+       tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN,
+                                        IDETAPE_DSC_RW_MAX);
        printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
-               "%dkB pipeline, %lums tDSC%s\n",
+               "%lums tDSC%s\n",
                drive->name, tape->name, *(u16 *)&tape->caps[14],
-               (*(u16 *)&tape->caps[16] * 512) / tape->stage_size,
-               tape->stage_size / 1024,
-               tape->max_stages * tape->stage_size / 1024,
+               (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
+               tape->buffer_size / 1024,
                tape->best_dsc_rw_freq * 1000 / HZ,
                drive->using_dma ? ", DMA":"");
 
@@ -3659,12 +2531,13 @@ static void ide_tape_release(struct kref *kref)
        ide_drive_t *drive = tape->drive;
        struct gendisk *g = tape->disk;
 
-       BUG_ON(tape->first_stage != NULL || tape->merge_stage_size);
+       BUG_ON(tape->merge_bh_size);
 
        drive->dsc_overlap = 0;
        drive->driver_data = NULL;
        device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
-       device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor + 128));
+       device_destroy(idetape_sysfs_class,
+                       MKDEV(IDETAPE_MAJOR, tape->minor + 128));
        idetape_devs[tape->minor] = NULL;
        g->private_data = NULL;
        put_disk(g);
@@ -3707,15 +2580,12 @@ static ide_driver_t idetape_driver = {
        .do_request             = idetape_do_request,
        .end_request            = idetape_end_request,
        .error                  = __ide_error,
-       .abort                  = __ide_abort,
 #ifdef CONFIG_IDE_PROC_FS
        .proc                   = idetape_proc,
 #endif
 };
 
-/*
- *     Our character device supporting functions, passed to register_chrdev.
- */
+/* Our character device supporting functions, passed to register_chrdev. */
 static const struct file_operations idetape_fops = {
        .owner          = THIS_MODULE,
        .read           = idetape_chrdev_read,
@@ -3730,7 +2600,8 @@ static int idetape_open(struct inode *inode, struct file *filp)
        struct gendisk *disk = inode->i_bdev->bd_disk;
        struct ide_tape_obj *tape;
 
-       if (!(tape = ide_tape_get(disk)))
+       tape = ide_tape_get(disk);
+       if (!tape)
                return -ENXIO;
 
        return 0;
@@ -3777,21 +2648,15 @@ static int ide_tape_probe(ide_drive_t *drive)
                goto failed;
        if (drive->media != ide_tape)
                goto failed;
-       if (!idetape_identify_device (drive)) {
-               printk(KERN_ERR "ide-tape: %s: not supported by this version of ide-tape\n", drive->name);
+       if (!idetape_identify_device(drive)) {
+               printk(KERN_ERR "ide-tape: %s: not supported by this version of"
+                               " the driver\n", drive->name);
                goto failed;
        }
-       if (drive->scsi) {
-               printk("ide-tape: passing drive %s to ide-scsi emulation.\n", drive->name);
-               goto failed;
-       }
-       if (strstr(drive->id->model, "OnStream DI-")) {
-               printk(KERN_WARNING "ide-tape: Use drive %s with ide-scsi emulation and osst.\n", drive->name);
-               printk(KERN_WARNING "ide-tape: OnStream support will be removed soon from ide-tape!\n");
-       }
-       tape = kzalloc(sizeof (idetape_tape_t), GFP_KERNEL);
+       tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL);
        if (tape == NULL) {
-               printk(KERN_ERR "ide-tape: %s: Can't allocate a tape structure\n", drive->name);
+               printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n",
+                               drive->name);
                goto failed;
        }
 
@@ -3821,10 +2686,12 @@ static int ide_tape_probe(ide_drive_t *drive)
 
        idetape_setup(drive, tape, minor);
 
-       device_create(idetape_sysfs_class, &drive->gendev,
-                     MKDEV(IDETAPE_MAJOR, minor), "%s", tape->name);
-       device_create(idetape_sysfs_class, &drive->gendev,
-                       MKDEV(IDETAPE_MAJOR, minor + 128), "n%s", tape->name);
+       device_create_drvdata(idetape_sysfs_class, &drive->gendev,
+                             MKDEV(IDETAPE_MAJOR, minor), NULL,
+                             "%s", tape->name);
+       device_create_drvdata(idetape_sysfs_class, &drive->gendev,
+                             MKDEV(IDETAPE_MAJOR, minor + 128), NULL,
+                             "n%s", tape->name);
 
        g->fops = &idetape_block_ops;
        ide_register_region(g);
@@ -3837,10 +2704,7 @@ failed:
        return -ENODEV;
 }
 
-MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
-MODULE_LICENSE("GPL");
-
-static void __exit idetape_exit (void)
+static void __exit idetape_exit(void)
 {
        driver_unregister(&idetape_driver.gen_driver);
        class_destroy(idetape_sysfs_class);
@@ -3859,7 +2723,8 @@ static int __init idetape_init(void)
        }
 
        if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
-               printk(KERN_ERR "ide-tape: Failed to register character device interface\n");
+               printk(KERN_ERR "ide-tape: Failed to register chrdev"
+                               " interface\n");
                error = -EBUSY;
                goto out_free_class;
        }
@@ -3882,3 +2747,5 @@ MODULE_ALIAS("ide:*m-tape*");
 module_init(idetape_init);
 module_exit(idetape_exit);
 MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
+MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
+MODULE_LICENSE("GPL");