firewire: Generalize the iso transmit descriptor buffer logic.
authorKristian Høgsberg <krh@redhat.com>
Fri, 16 Feb 2007 22:34:39 +0000 (17:34 -0500)
committerStefan Richter <stefanr@s5r6.in-berlin.de>
Fri, 9 Mar 2007 21:02:58 +0000 (22:02 +0100)
The descriptor circular buffer logic used for iso transmission is
useful for async transmit too, so pull the sharable logic out in
a few standalone functions.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
drivers/firewire/fw-ohci.c

index 8499d70..86fe55c 100644 (file)
@@ -75,6 +75,30 @@ struct ar_context {
        struct tasklet_struct tasklet;
 };
 
+struct context;
+
+typedef int (*descriptor_callback_t)(struct context *ctx,
+                                    struct descriptor *d,
+                                    struct descriptor *last);
+struct context {
+       struct fw_ohci *ohci;
+       u32 regs;
+       struct descriptor *buffer;
+       dma_addr_t buffer_bus;
+       size_t buffer_size;
+       struct descriptor *head_descriptor;
+       struct descriptor *tail_descriptor;
+       struct descriptor *tail_descriptor_last;
+       struct descriptor *prev_descriptor;
+
+       descriptor_callback_t callback;
+
+       struct tasklet_struct tasklet;
+};
+
+
 struct at_context {
        struct fw_ohci *ohci;
        dma_addr_t descriptor_bus;
@@ -103,15 +127,7 @@ struct at_context {
 
 struct iso_context {
        struct fw_iso_context base;
-       struct tasklet_struct tasklet;
-       u32 regs;
-
-       struct descriptor *buffer;
-       dma_addr_t buffer_bus;
-       struct descriptor *head_descriptor;
-       struct descriptor *tail_descriptor;
-       struct descriptor *tail_descriptor_last;
-       struct descriptor *prev_descriptor;
+       struct context context;
 };
 
 #define CONFIG_ROM_SIZE 1024
@@ -394,6 +410,154 @@ ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci, u32 regs)
 
        return 0;
 }
+static void context_tasklet(unsigned long data)
+{
+       struct context *ctx = (struct context *) data;
+       struct fw_ohci *ohci = ctx->ohci;
+       struct descriptor *d, *last;
+       u32 address;
+       int z;
+
+       dma_sync_single_for_cpu(ohci->card.device, ctx->buffer_bus,
+                               ctx->buffer_size, DMA_TO_DEVICE);
+
+       d    = ctx->tail_descriptor;
+       last = ctx->tail_descriptor_last;
+
+       while (last->branch_address != 0) {
+               address = le32_to_cpu(last->branch_address);
+               z = address & 0xf;
+               d = ctx->buffer + (address - ctx->buffer_bus) / sizeof *d;
+               last = (z == 2) ? d : d + z - 1;
+
+               if (!ctx->callback(ctx, d, last))
+                       break;
+
+               ctx->tail_descriptor      = d;
+               ctx->tail_descriptor_last = last;
+       }
+}
+
+static int
+context_init(struct context *ctx, struct fw_ohci *ohci,
+            size_t buffer_size, u32 regs,
+            descriptor_callback_t callback)
+{
+       ctx->ohci = ohci;
+       ctx->regs = regs;
+       ctx->buffer_size = buffer_size;
+       ctx->buffer = kmalloc(buffer_size, GFP_KERNEL);
+       if (ctx->buffer == NULL)
+               return -ENOMEM;
+
+       tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
+       ctx->callback = callback;
+
+       ctx->buffer_bus =
+               dma_map_single(ohci->card.device, ctx->buffer,
+                              buffer_size, DMA_TO_DEVICE);
+       if (dma_mapping_error(ctx->buffer_bus)) {
+               kfree(ctx->buffer);
+               return -ENOMEM;
+       }
+
+       ctx->head_descriptor      = ctx->buffer;
+       ctx->prev_descriptor      = ctx->buffer;
+       ctx->tail_descriptor      = ctx->buffer;
+       ctx->tail_descriptor_last = ctx->buffer;
+
+       /* We put a dummy descriptor in the buffer that has a NULL
+        * branch address and looks like it's been sent.  That way we
+        * have a descriptor to append DMA programs to.  Also, the
+        * ring buffer invariant is that it always has at least one
+        * element so that head == tail means buffer full. */
+
+       memset(ctx->head_descriptor, 0, sizeof *ctx->head_descriptor);
+       ctx->head_descriptor->control = cpu_to_le16(descriptor_output_last);
+       ctx->head_descriptor->transfer_status = cpu_to_le16(0x8011);
+       ctx->head_descriptor++;
+
+       return 0;
+}
+
+ static void
+context_release(struct context *ctx)
+{
+       struct fw_card *card = &ctx->ohci->card;
+
+       dma_unmap_single(card->device, ctx->buffer_bus,
+                        ctx->buffer_size, DMA_TO_DEVICE);
+       kfree(ctx->buffer);
+}
+
+static struct descriptor *
+context_get_descriptors(struct context *ctx, int z, dma_addr_t *d_bus)
+{
+       struct descriptor *d, *tail, *end;
+
+       d = ctx->head_descriptor;
+       tail = ctx->tail_descriptor;
+       end = ctx->buffer + ctx->buffer_size / sizeof(struct descriptor);
+
+       if (d + z <= tail) {
+               goto has_space;
+       } else if (d > tail && d + z <= end) {
+               goto has_space;
+       } else if (d > tail && ctx->buffer + z <= tail) {
+               d = ctx->buffer;
+               goto has_space;
+       }
+
+       return NULL;
+
+ has_space:
+       memset(d, 0, z * sizeof *d);
+       *d_bus = ctx->buffer_bus + (d - ctx->buffer) * sizeof *d;
+
+       return d;
+}
+
+static void context_run(struct context *ctx, u32 cycle_match)
+{
+       struct fw_ohci *ohci = ctx->ohci;
+
+       reg_write(ohci, command_ptr(ctx->regs),
+                 le32_to_cpu(ctx->tail_descriptor_last->branch_address));
+       reg_write(ohci, control_clear(ctx->regs), ~0);
+       reg_write(ohci, control_set(ctx->regs), CONTEXT_RUN | cycle_match);
+       flush_writes(ohci);
+}
+
+static void context_append(struct context *ctx,
+                          struct descriptor *d, int z, int extra)
+{
+       dma_addr_t d_bus;
+
+       d_bus = ctx->buffer_bus + (d - ctx->buffer) * sizeof *d;
+
+       ctx->head_descriptor = d + z + extra;
+       ctx->prev_descriptor->branch_address = cpu_to_le32(d_bus | z);
+       ctx->prev_descriptor = z == 2 ? d : d + z - 1;
+
+       dma_sync_single_for_device(ctx->ohci->card.device, ctx->buffer_bus,
+                                  ctx->buffer_size, DMA_TO_DEVICE);
+
+       reg_write(ctx->ohci, control_set(ctx->regs), CONTEXT_WAKE);
+       flush_writes(ctx->ohci);
+}
+
+static void context_stop(struct context *ctx)
+{
+       u32 reg;
+
+       reg_write(ctx->ohci, control_clear(ctx->regs), CONTEXT_RUN);
+
+       reg = reg_read(ctx->ohci, control_set(ctx->regs));
+       if (reg & CONTEXT_ACTIVE)
+               fw_notify("Tried to stop context, but it is still active "
+                         "(0x%08x).\n", reg);
+}
 
 static void
 do_packet_callbacks(struct fw_ohci *ohci, struct list_head *list)
@@ -852,7 +1016,7 @@ static irqreturn_t irq_handler(int irq, void *data)
 
        while (iso_event) {
                i = ffs(iso_event) - 1;
-               tasklet_schedule(&ohci->ir_context_list[i].tasklet);
+               tasklet_schedule(&ohci->ir_context_list[i].context.tasklet);
                iso_event &= ~(1 << i);
        }
 
@@ -861,7 +1025,7 @@ static irqreturn_t irq_handler(int irq, void *data)
 
        while (iso_event) {
                i = ffs(iso_event) - 1;
-               tasklet_schedule(&ohci->it_context_list[i].tasklet);
+               tasklet_schedule(&ohci->it_context_list[i].context.tasklet);
                iso_event &= ~(1 << i);
        }
 
@@ -1085,64 +1249,41 @@ static void ir_context_tasklet(unsigned long data)
 
 #define ISO_BUFFER_SIZE (64 * 1024)
 
-static void flush_iso_context(struct iso_context *ctx)
-{
-       struct fw_ohci *ohci = fw_ohci(ctx->base.card);
-       struct descriptor *d, *last;
-       u32 address;
-       int z;
-
-       dma_sync_single_for_cpu(ohci->card.device, ctx->buffer_bus,
-                               ISO_BUFFER_SIZE, DMA_TO_DEVICE);
-
-       d    = ctx->tail_descriptor;
-       last = ctx->tail_descriptor_last;
-
-       while (last->branch_address != 0 && last->transfer_status != 0) {
-               address = le32_to_cpu(last->branch_address);
-               z = address & 0xf;
-               d = ctx->buffer + (address - ctx->buffer_bus) / sizeof *d;
-
-               if (z == 2)
-                       last = d;
-               else
-                       last = d + z - 1;
-
-               if (le16_to_cpu(last->control) & descriptor_irq_always)
-                       ctx->base.callback(&ctx->base,
-                                          0, le16_to_cpu(last->res_count),
-                                          ctx->base.callback_data);
-       }
-
-       ctx->tail_descriptor      = d;
-       ctx->tail_descriptor_last = last;
-}
-
-static void it_context_tasklet(unsigned long data)
+static int handle_it_packet(struct context *context,
+                           struct descriptor *d,
+                           struct descriptor *last)
 {
-       struct iso_context *ctx = (struct iso_context *)data;
-
-       flush_iso_context(ctx);
+       struct iso_context *ctx =
+               container_of(context, struct iso_context, context);
+       if (last->transfer_status == 0)
+               /* This descriptor isn't done yet, stop iteration. */
+               return 0;
+
+       if (le16_to_cpu(last->control) & descriptor_irq_always)
+               ctx->base.callback(&ctx->base,
+                                  0, le16_to_cpu(last->res_count),
+                                  ctx->base.callback_data);
+
+       return 1;
 }
 
-static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
-                                                       int type)
+static struct fw_iso_context *
+ohci_allocate_iso_context(struct fw_card *card, int type)
 {
        struct fw_ohci *ohci = fw_ohci(card);
        struct iso_context *ctx, *list;
-       void (*tasklet) (unsigned long data);
+       descriptor_callback_t callback;
        u32 *mask;
        unsigned long flags;
-       int index;
+       int index, retval;
 
        if (type == FW_ISO_CONTEXT_TRANSMIT) {
                mask = &ohci->it_context_mask;
                list = ohci->it_context_list;
-               tasklet = it_context_tasklet;
+               callback = handle_it_packet;
        } else {
-               mask = &ohci->ir_context_mask;
-               list = ohci->ir_context_list;
-               tasklet = ir_context_tasklet;
+               return ERR_PTR(-EINVAL);
        }
 
        spin_lock_irqsave(&ohci->lock, flags);
@@ -1156,50 +1297,22 @@ static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
 
        ctx = &list[index];
        memset(ctx, 0, sizeof *ctx);
-       tasklet_init(&ctx->tasklet, tasklet, (unsigned long)ctx);
-
-       ctx->buffer = kmalloc(ISO_BUFFER_SIZE, GFP_KERNEL);
-       if (ctx->buffer == NULL)
-               goto buffer_alloc_failed;
-
-       ctx->buffer_bus =
-           dma_map_single(card->device, ctx->buffer,
-                          ISO_BUFFER_SIZE, DMA_TO_DEVICE);
-       if (dma_mapping_error(ctx->buffer_bus))
-               goto buffer_map_failed;
-
-       ctx->head_descriptor      = ctx->buffer;
-       ctx->prev_descriptor      = ctx->buffer;
-       ctx->tail_descriptor      = ctx->buffer;
-       ctx->tail_descriptor_last = ctx->buffer;
-
-       /* We put a dummy descriptor in the buffer that has a NULL
-        * branch address and looks like it's been sent.  That way we
-        * have a descriptor to append DMA programs to.  Also, the
-        * ring buffer invariant is that it always has at least one
-        * element so that head == tail means buffer full. */
-
-       memset(ctx->head_descriptor, 0, sizeof *ctx->head_descriptor);
-       ctx->head_descriptor->control = cpu_to_le16(descriptor_output_last);
-       ctx->head_descriptor->transfer_status = cpu_to_le16(0x8011);
-       ctx->head_descriptor++;
+       retval = context_init(&ctx->context, ohci, ISO_BUFFER_SIZE,
+                             OHCI1394_IsoXmitContextBase(index), callback);
+       if (retval < 0) {
+               spin_lock_irqsave(&ohci->lock, flags);
+               *mask |= 1 << index;
+               spin_unlock_irqrestore(&ohci->lock, flags);
+               return ERR_PTR(retval);
+       }
 
        return &ctx->base;
-
- buffer_map_failed:
-       kfree(ctx->buffer);
- buffer_alloc_failed:
-       spin_lock_irqsave(&ohci->lock, flags);
-       *mask |= 1 << index;
-       spin_unlock_irqrestore(&ohci->lock, flags);
-
-       return ERR_PTR(-ENOMEM);
 }
 
 static int ohci_send_iso(struct fw_iso_context *base, s32 cycle)
 {
-       struct iso_context *ctx = (struct iso_context *)base;
-       struct fw_ohci *ohci = fw_ohci(ctx->base.card);
+       struct iso_context *ctx = container_of(base, struct iso_context, base);
+       struct fw_ohci *ohci = ctx->context.ohci;
        u32 cycle_match = 0;
        int index;
 
@@ -1209,12 +1322,7 @@ static int ohci_send_iso(struct fw_iso_context *base, s32 cycle)
                        (cycle & 0x7fff) << 16;
 
        reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
-       reg_write(ohci, OHCI1394_IsoXmitCommandPtr(index),
-                 le32_to_cpu(ctx->tail_descriptor_last->branch_address));
-       reg_write(ohci, OHCI1394_IsoXmitContextControlClear(index), ~0);
-       reg_write(ohci, OHCI1394_IsoXmitContextControlSet(index),
-                 CONTEXT_RUN | cycle_match);
-       flush_writes(ohci);
+       context_run(&ctx->context, cycle_match);
 
        return 0;
 }
@@ -1222,12 +1330,10 @@ static int ohci_send_iso(struct fw_iso_context *base, s32 cycle)
 static void ohci_free_iso_context(struct fw_iso_context *base)
 {
        struct fw_ohci *ohci = fw_ohci(base->card);
-       struct iso_context *ctx = (struct iso_context *)base;
+       struct iso_context *ctx = container_of(base, struct iso_context, base);
        unsigned long flags;
        int index;
 
-       flush_iso_context(ctx);
-
        spin_lock_irqsave(&ohci->lock, flags);
 
        if (ctx->base.type == FW_ISO_CONTEXT_TRANSMIT) {
@@ -1243,8 +1349,7 @@ static void ohci_free_iso_context(struct fw_iso_context *base)
        }
        flush_writes(ohci);
 
-       dma_unmap_single(ohci->card.device, ctx->buffer_bus,
-                        ISO_BUFFER_SIZE, DMA_TO_DEVICE);
+       context_release(&ctx->context);
 
        spin_unlock_irqrestore(&ohci->lock, flags);
 }
@@ -1255,24 +1360,20 @@ ohci_queue_iso(struct fw_iso_context *base,
               struct fw_iso_buffer *buffer,
               unsigned long payload)
 {
-       struct iso_context *ctx = (struct iso_context *)base;
-       struct fw_ohci *ohci = fw_ohci(ctx->base.card);
-       struct descriptor *d, *end, *last, *tail, *pd;
+       struct iso_context *ctx = container_of(base, struct iso_context, base);
+       struct descriptor *d, *last, *pd;
        struct fw_iso_packet *p;
        __le32 *header;
        dma_addr_t d_bus, page_bus;
        u32 z, header_z, payload_z, irq;
        u32 payload_index, payload_end_index, next_page_index;
-       int index, page, end_page, i, length, offset;
+       int page, end_page, i, length, offset;
 
        /* FIXME: Cycle lost behavior should be configurable: lose
         * packet, retransmit or terminate.. */
 
        p = packet;
        payload_index = payload;
-       d = ctx->head_descriptor;
-       tail = ctx->tail_descriptor;
-       end = ctx->buffer + ISO_BUFFER_SIZE / sizeof(struct descriptor);
 
        if (p->skip)
                z = 1;
@@ -1293,21 +1394,9 @@ ohci_queue_iso(struct fw_iso_context *base,
        /* Get header size in number of descriptors. */
        header_z = DIV_ROUND_UP(p->header_length, sizeof *d);
 
-       if (d + z + header_z <= tail) {
-               goto has_space;
-       } else if (d > tail && d + z + header_z <= end) {
-               goto has_space;
-       } else if (d > tail && ctx->buffer + z + header_z <= tail) {
-               d = ctx->buffer;
-               goto has_space;
-       }
-
-       /* No space in buffer */
-       return -1;
-
- has_space:
-       memset(d, 0, (z + header_z) * sizeof *d);
-       d_bus = ctx->buffer_bus + (d - ctx->buffer) * sizeof *d;
+       d = context_get_descriptors(&ctx->context, z + header_z, &d_bus);
+       if (d == NULL)
+               return -ENOMEM;
 
        if (!p->skip) {
                d[0].control   = cpu_to_le16(descriptor_key_immediate);
@@ -1346,31 +1435,18 @@ ohci_queue_iso(struct fw_iso_context *base,
                payload_index += length;
        }
 
-       if (z == 2)
-               last = d;
-       else
-               last = d + z - 1;
-
        if (p->interrupt)
                irq = descriptor_irq_always;
        else
                irq = descriptor_no_irq;
 
+       last = z == 2 ? d : d + z - 1;
        last->control |= cpu_to_le16(descriptor_output_last |
                                     descriptor_status |
                                     descriptor_branch_always |
                                     irq);
 
-       dma_sync_single_for_device(ohci->card.device, ctx->buffer_bus,
-                                  ISO_BUFFER_SIZE, DMA_TO_DEVICE);
-
-       ctx->head_descriptor = d + z + header_z;
-       ctx->prev_descriptor->branch_address = cpu_to_le32(d_bus | z);
-       ctx->prev_descriptor = last;
-
-       index = ctx - ohci->it_context_list;
-       reg_write(ohci, OHCI1394_IsoXmitContextControlSet(index), CONTEXT_WAKE);
-       flush_writes(ohci);
+       context_append(&ctx->context, d, z, header_z);
 
        return 0;
 }