firewire: unnecessary BM delay after generation rollover
[safe/jmp/linux-2.6] / drivers / firewire / fw-card.c
index b2aa855..17a80ce 100644 (file)
  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
-#include <linux/module.h>
-#include <linux/errno.h>
-#include <linux/device.h>
-#include <linux/rwsem.h>
+#include <linux/completion.h>
 #include <linux/crc-itu-t.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/kref.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+
 #include "fw-transaction.h"
 #include "fw-topology.h"
 #include "fw-device.h"
@@ -38,29 +42,29 @@ int fw_compute_block_crc(u32 *block)
        return length;
 }
 
-static DECLARE_RWSEM(card_rwsem);
+static DEFINE_MUTEX(card_mutex);
 static LIST_HEAD(card_list);
 
 static LIST_HEAD(descriptor_list);
 static int descriptor_count;
 
-#define bib_crc(v)             ((v) <<  0)
-#define bib_crc_length(v)      ((v) << 16)
-#define bib_info_length(v)     ((v) << 24)
-
-#define bib_link_speed(v)      ((v) <<  0)
-#define bib_generation(v)      ((v) <<  4)
-#define bib_max_rom(v)         ((v) <<  8)
-#define bib_max_receive(v)     ((v) << 12)
-#define bib_cyc_clk_acc(v)     ((v) << 16)
-#define bib_pmc                        ((1) << 27)
-#define bib_bmc                        ((1) << 28)
-#define bib_isc                        ((1) << 29)
-#define bib_cmc                        ((1) << 30)
-#define bib_imc                        ((1) << 31)
+#define BIB_CRC(v)             ((v) <<  0)
+#define BIB_CRC_LENGTH(v)      ((v) << 16)
+#define BIB_INFO_LENGTH(v)     ((v) << 24)
+
+#define BIB_LINK_SPEED(v)      ((v) <<  0)
+#define BIB_GENERATION(v)      ((v) <<  4)
+#define BIB_MAX_ROM(v)         ((v) <<  8)
+#define BIB_MAX_RECEIVE(v)     ((v) << 12)
+#define BIB_CYC_CLK_ACC(v)     ((v) << 16)
+#define BIB_PMC                        ((1) << 27)
+#define BIB_BMC                        ((1) << 28)
+#define BIB_ISC                        ((1) << 29)
+#define BIB_CMC                        ((1) << 30)
+#define BIB_IMC                        ((1) << 31)
 
 static u32 *
-generate_config_rom (struct fw_card *card, size_t *config_rom_length)
+generate_config_rom(struct fw_card *card, size_t *config_rom_length)
 {
        struct fw_descriptor *desc;
        static u32 config_rom[256];
@@ -71,20 +75,20 @@ generate_config_rom (struct fw_card *card, size_t *config_rom_length)
         * controller, block reads to the config rom accesses the host
         * memory, but quadlet read access the hardware bus info block
         * registers.  That's just crack, but it means we should make
-        * sure the contents of bus info block in host memory mathces
+        * sure the contents of bus info block in host memory matches
         * the version stored in the OHCI registers.
         */
 
-       memset(config_rom, 0, sizeof config_rom);
-       config_rom[0] = bib_crc_length(4) | bib_info_length(4) | bib_crc(0);
+       memset(config_rom, 0, sizeof(config_rom));
+       config_rom[0] = BIB_CRC_LENGTH(4) | BIB_INFO_LENGTH(4) | BIB_CRC(0);
        config_rom[1] = 0x31333934;
 
        config_rom[2] =
-               bib_link_speed(card->link_speed) |
-               bib_generation(card->config_rom_generation++ % 14 + 2) |
-               bib_max_rom(2) |
-               bib_max_receive(card->max_receive) |
-               bib_bmc | bib_isc | bib_cmc | bib_imc;
+               BIB_LINK_SPEED(card->link_speed) |
+               BIB_GENERATION(card->config_rom_generation++ % 14 + 2) |
+               BIB_MAX_ROM(2) |
+               BIB_MAX_RECEIVE(card->max_receive) |
+               BIB_BMC | BIB_ISC | BIB_CMC | BIB_IMC;
        config_rom[3] = card->guid >> 32;
        config_rom[4] = card->guid;
 
@@ -125,7 +129,7 @@ generate_config_rom (struct fw_card *card, size_t *config_rom_length)
 }
 
 static void
-update_config_roms (void)
+update_config_roms(void)
 {
        struct fw_card *card;
        u32 *config_rom;
@@ -138,7 +142,7 @@ update_config_roms (void)
 }
 
 int
-fw_core_add_descriptor (struct fw_descriptor *desc)
+fw_core_add_descriptor(struct fw_descriptor *desc)
 {
        size_t i;
 
@@ -154,24 +158,23 @@ fw_core_add_descriptor (struct fw_descriptor *desc)
        if (i != desc->length)
                return -EINVAL;
 
-       down_write(&card_rwsem);
+       mutex_lock(&card_mutex);
 
-       list_add_tail (&desc->link, &descriptor_list);
+       list_add_tail(&desc->link, &descriptor_list);
        descriptor_count++;
        if (desc->immediate > 0)
                descriptor_count++;
        update_config_roms();
 
-       up_write(&card_rwsem);
+       mutex_unlock(&card_mutex);
 
        return 0;
 }
-EXPORT_SYMBOL(fw_core_add_descriptor);
 
 void
-fw_core_remove_descriptor (struct fw_descriptor *desc)
+fw_core_remove_descriptor(struct fw_descriptor *desc)
 {
-       down_write(&card_rwsem);
+       mutex_lock(&card_mutex);
 
        list_del(&desc->link);
        descriptor_count--;
@@ -179,55 +182,57 @@ fw_core_remove_descriptor (struct fw_descriptor *desc)
                descriptor_count--;
        update_config_roms();
 
-       up_write(&card_rwsem);
+       mutex_unlock(&card_mutex);
 }
-EXPORT_SYMBOL(fw_core_remove_descriptor);
 
 static const char gap_count_table[] = {
        63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40
 };
 
-struct bm_data {
-       struct fw_transaction t;
-       struct {
-               __be32 arg;
-               __be32 data;
-       } lock;
-       u32 old;
-       int rcode;
-       struct completion done;
-};
-
-static void
-complete_bm_lock(struct fw_card *card, int rcode,
-                void *payload, size_t length, void *data)
+void
+fw_schedule_bm_work(struct fw_card *card, unsigned long delay)
 {
-       struct bm_data *bmd = data;
+       int scheduled;
 
-       if (rcode == RCODE_COMPLETE)
-               bmd->old = be32_to_cpu(*(__be32 *) payload);
-       bmd->rcode = rcode;
-       complete(&bmd->done);
+       fw_card_get(card);
+       scheduled = schedule_delayed_work(&card->work, delay);
+       if (!scheduled)
+               fw_card_put(card);
 }
 
 static void
 fw_card_bm_work(struct work_struct *work)
 {
        struct fw_card *card = container_of(work, struct fw_card, work.work);
-       struct fw_device *root;
-       struct bm_data bmd;
+       struct fw_device *root_device;
+       struct fw_node *root_node, *local_node;
        unsigned long flags;
-       int root_id, new_root_id, irm_id, gap_count, generation, grace;
-       int do_reset = 0;
+       int root_id, new_root_id, irm_id, gap_count, generation, grace, rcode;
+       bool do_reset = false;
+       bool root_device_is_running;
+       bool root_device_is_cmc;
+       __be32 lock_data[2];
 
        spin_lock_irqsave(&card->lock, flags);
+       local_node = card->local_node;
+       root_node  = card->root_node;
+
+       if (local_node == NULL) {
+               spin_unlock_irqrestore(&card->lock, flags);
+               goto out_put_card;
+       }
+       fw_node_get(local_node);
+       fw_node_get(root_node);
 
        generation = card->generation;
-       root = card->root_node->data;
-       root_id = card->root_node->node_id;
+       root_device = root_node->data;
+       root_device_is_running = root_device &&
+                       atomic_read(&root_device->state) == FW_DEVICE_RUNNING;
+       root_device_is_cmc = root_device && root_device->cmc;
+       root_id = root_node->node_id;
        grace = time_after(jiffies, card->reset_jiffies + DIV_ROUND_UP(HZ, 10));
 
-       if (card->bm_generation + 1 == generation ||
+       if (is_next_generation(generation, card->bm_generation) ||
            (card->bm_generation != generation && grace)) {
                /*
                 * This first step is to figure out who is IRM and
@@ -243,46 +248,41 @@ fw_card_bm_work(struct work_struct *work)
 
                irm_id = card->irm_node->node_id;
                if (!card->irm_node->link_on) {
-                       new_root_id = card->local_node->node_id;
+                       new_root_id = local_node->node_id;
                        fw_notify("IRM has link off, making local node (%02x) root.\n",
                                  new_root_id);
                        goto pick_me;
                }
 
-               bmd.lock.arg = cpu_to_be32(0x3f);
-               bmd.lock.data = cpu_to_be32(card->local_node->node_id);
+               lock_data[0] = cpu_to_be32(0x3f);
+               lock_data[1] = cpu_to_be32(local_node->node_id);
 
                spin_unlock_irqrestore(&card->lock, flags);
 
-               init_completion(&bmd.done);
-               fw_send_request(card, &bmd.t, TCODE_LOCK_COMPARE_SWAP,
-                               irm_id, generation,
-                               SCODE_100, CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID,
-                               &bmd.lock, sizeof bmd.lock,
-                               complete_bm_lock, &bmd);
-               wait_for_completion(&bmd.done);
+               rcode = fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
+                               irm_id, generation, SCODE_100,
+                               CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID,
+                               lock_data, sizeof(lock_data));
 
-               if (bmd.rcode == RCODE_GENERATION) {
-                       /*
-                        * Another bus reset happened. Just return,
-                        * the BM work has been rescheduled.
-                        */
-                       return;
-               }
+               if (rcode == RCODE_GENERATION)
+                       /* Another bus reset, BM work has been rescheduled. */
+                       goto out;
 
-               if (bmd.rcode == RCODE_COMPLETE && bmd.old != 0x3f)
+               if (rcode == RCODE_COMPLETE &&
+                   lock_data[0] != cpu_to_be32(0x3f))
                        /* Somebody else is BM, let them do the work. */
-                       return;
+                       goto out;
 
                spin_lock_irqsave(&card->lock, flags);
-               if (bmd.rcode != RCODE_COMPLETE) {
+
+               if (rcode != RCODE_COMPLETE) {
                        /*
                         * The lock request failed, maybe the IRM
                         * isn't really IRM capable after all. Let's
                         * do a bus reset and pick the local node as
                         * root, and thus, IRM.
                         */
-                       new_root_id = card->local_node->node_id;
+                       new_root_id = local_node->node_id;
                        fw_notify("BM lock failed, making local node (%02x) root.\n",
                                  new_root_id);
                        goto pick_me;
@@ -294,8 +294,8 @@ fw_card_bm_work(struct work_struct *work)
                 * this task 100ms from now.
                 */
                spin_unlock_irqrestore(&card->lock, flags);
-               schedule_delayed_work(&card->work, DIV_ROUND_UP(HZ, 10));
-               return;
+               fw_schedule_bm_work(card, DIV_ROUND_UP(HZ, 10));
+               goto out;
        }
 
        /*
@@ -305,20 +305,20 @@ fw_card_bm_work(struct work_struct *work)
         */
        card->bm_generation = generation;
 
-       if (root == NULL) {
+       if (root_device == NULL) {
                /*
                 * Either link_on is false, or we failed to read the
                 * config rom.  In either case, pick another root.
                 */
-               new_root_id = card->local_node->node_id;
-       } else if (atomic_read(&root->state) != FW_DEVICE_RUNNING) {
+               new_root_id = local_node->node_id;
+       } else if (!root_device_is_running) {
                /*
                 * If we haven't probed this device yet, bail out now
                 * and let's try again once that's done.
                 */
                spin_unlock_irqrestore(&card->lock, flags);
-               return;
-       } else if (root->config_rom[2] & bib_cmc) {
+               goto out;
+       } else if (root_device_is_cmc) {
                /*
                 * FIXME: I suppose we should set the cmstr bit in the
                 * STATE_CLEAR register of this node, as described in
@@ -332,26 +332,29 @@ fw_card_bm_work(struct work_struct *work)
                 * successfully read the config rom, but it's not
                 * cycle master capable.
                 */
-               new_root_id = card->local_node->node_id;
+               new_root_id = local_node->node_id;
        }
 
  pick_me:
-       /* Now figure out what gap count to set. */
-       if (card->topology_type == FW_TOPOLOGY_A &&
-           card->root_node->max_hops < ARRAY_SIZE(gap_count_table))
-               gap_count = gap_count_table[card->root_node->max_hops];
+       /*
+        * Pick a gap count from 1394a table E-1.  The table doesn't cover
+        * the typically much larger 1394b beta repeater delays though.
+        */
+       if (!card->beta_repeaters_present &&
+           root_node->max_hops < ARRAY_SIZE(gap_count_table))
+               gap_count = gap_count_table[root_node->max_hops];
        else
                gap_count = 63;
 
        /*
-        * Finally, figure out if we should do a reset or not.  If we've
-        * done less that 5 resets with the same physical topology and we
+        * Finally, figure out if we should do a reset or not.  If we have
+        * done less than 5 resets with the same physical topology and we
         * have either a new root or a new gap count setting, let's do it.
         */
 
        if (card->bm_retries++ < 5 &&
            (card->gap_count != gap_count || new_root_id != root_id))
-               do_reset = 1;
+               do_reset = true;
 
        spin_unlock_irqrestore(&card->lock, flags);
 
@@ -361,6 +364,11 @@ fw_card_bm_work(struct work_struct *work)
                fw_send_phy_config(card, new_root_id, generation, gap_count);
                fw_core_initiate_bus_reset(card, 1);
        }
+ out:
+       fw_node_put(root_node);
+       fw_node_put(local_node);
+ out_put_card:
+       fw_card_put(card);
 }
 
 static void
@@ -377,14 +385,16 @@ fw_card_initialize(struct fw_card *card, const struct fw_card_driver *driver,
 {
        static atomic_t index = ATOMIC_INIT(-1);
 
-       kref_init(&card->kref);
        card->index = atomic_inc_return(&index);
        card->driver = driver;
        card->device = device;
        card->current_tlabel = 0;
        card->tlabel_mask = 0;
        card->color = 0;
+       card->broadcast_channel = BROADCAST_CHANNEL_INITIAL;
 
+       kref_init(&card->kref);
+       init_completion(&card->done);
        INIT_LIST_HEAD(&card->transaction_list);
        spin_lock_init(&card->lock);
        setup_timer(&card->flush_timer,
@@ -407,21 +417,10 @@ fw_card_add(struct fw_card *card,
        card->link_speed = link_speed;
        card->guid = guid;
 
-       /* Activate link_on bit and contender bit in our self ID packets.*/
-       if (card->driver->update_phy_reg(card, 4, 0,
-                                        PHY_LINK_ACTIVE | PHY_CONTENDER) < 0)
-               return -EIO;
-
-       /*
-        * The subsystem grabs a reference when the card is added and
-        * drops it when the driver calls fw_core_remove_card.
-        */
-       fw_card_get(card);
-
-       down_write(&card_rwsem);
-       config_rom = generate_config_rom (card, &length);
+       mutex_lock(&card_mutex);
+       config_rom = generate_config_rom(card, &length);
        list_add_tail(&card->link, &card_list);
-       up_write(&card_rwsem);
+       mutex_unlock(&card_mutex);
 
        return card->driver->enable(card, config_rom, length);
 }
@@ -488,7 +487,6 @@ dummy_enable_phys_dma(struct fw_card *card,
 }
 
 static struct fw_card_driver dummy_driver = {
-       .name            = "dummy",
        .enable          = dummy_enable,
        .update_phy_reg  = dummy_update_phy_reg,
        .set_config_rom  = dummy_set_config_rom,
@@ -499,55 +497,37 @@ static struct fw_card_driver dummy_driver = {
 };
 
 void
+fw_card_release(struct kref *kref)
+{
+       struct fw_card *card = container_of(kref, struct fw_card, kref);
+
+       complete(&card->done);
+}
+
+void
 fw_core_remove_card(struct fw_card *card)
 {
        card->driver->update_phy_reg(card, 4,
                                     PHY_LINK_ACTIVE | PHY_CONTENDER, 0);
        fw_core_initiate_bus_reset(card, 1);
 
-       down_write(&card_rwsem);
+       mutex_lock(&card_mutex);
        list_del(&card->link);
-       up_write(&card_rwsem);
+       mutex_unlock(&card_mutex);
 
        /* Set up the dummy driver. */
        card->driver = &dummy_driver;
 
-       fw_flush_transactions(card);
-
        fw_destroy_nodes(card);
 
+       /* Wait for all users, especially device workqueue jobs, to finish. */
        fw_card_put(card);
-}
-EXPORT_SYMBOL(fw_core_remove_card);
-
-struct fw_card *
-fw_card_get(struct fw_card *card)
-{
-       kref_get(&card->kref);
+       wait_for_completion(&card->done);
 
-       return card;
+       WARN_ON(!list_empty(&card->transaction_list));
+       del_timer_sync(&card->flush_timer);
 }
-EXPORT_SYMBOL(fw_card_get);
-
-static void
-release_card(struct kref *kref)
-{
-       struct fw_card *card = container_of(kref, struct fw_card, kref);
-
-       kfree(card);
-}
-
-/*
- * An assumption for fw_card_put() is that the card driver allocates
- * the fw_card struct with kalloc and that it has been shut down
- * before the last ref is dropped.
- */
-void
-fw_card_put(struct fw_card *card)
-{
-       kref_put(&card->kref, release_card);
-}
-EXPORT_SYMBOL(fw_card_put);
+EXPORT_SYMBOL(fw_core_remove_card);
 
 int
 fw_core_initiate_bus_reset(struct fw_card *card, int short_reset)