Date: Mon, 3 Mar 2014 23:23:51 +0100 From: Stefan Richter Subject: firewire: sbp2: replace card lock by target lock firewire-core uses fw_card.lock to protect topology data and transaction data. firewire-sbp2 uses fw_card.lock for entirely unrelated purposes. Introduce a sbp2_target.lock to firewire-sbp2 and replace all fw_card.lock uses in the driver. fw_card.lock is now entirely private to firewire-core. This has no immediate advantage apart from making it clear in the code that firewire-sbp2 does not interact with the core via the core lock. Signed-off-by: Stefan Richter --- drivers/firewire/sbp2.c | 60 +++++++++++++++++++--------------------- 1 file changed, 29 insertions(+), 31 deletions(-) --- a/drivers/firewire/sbp2.c +++ b/drivers/firewire/sbp2.c @@ -174,6 +174,7 @@ struct sbp2_target { unsigned int mgt_orb_timeout; unsigned int max_payload; + spinlock_t lock; int dont_block; /* counter for each logical unit */ int blocked; /* ditto */ }; @@ -270,6 +271,7 @@ struct sbp2_orb { dma_addr_t request_bus; int rcode; void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status); + struct sbp2_logical_unit *lu; struct list_head link; }; @@ -321,7 +323,6 @@ struct sbp2_command_orb { u8 command_block[SBP2_MAX_CDB_SIZE]; } request; struct scsi_cmnd *cmd; - struct sbp2_logical_unit *lu; struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8))); dma_addr_t page_table_bus; @@ -444,7 +445,7 @@ static void sbp2_status_write(struct fw_ } /* Lookup the orb corresponding to this status write. */ - spin_lock_irqsave(&card->lock, flags); + spin_lock_irqsave(&lu->tgt->lock, flags); list_for_each_entry(orb, &lu->orb_list, link) { if (STATUS_GET_ORB_HIGH(status) == 0 && STATUS_GET_ORB_LOW(status) == orb->request_bus) { @@ -453,7 +454,7 @@ static void sbp2_status_write(struct fw_ break; } } - spin_unlock_irqrestore(&card->lock, flags); + spin_unlock_irqrestore(&lu->tgt->lock, flags); if (&orb->link != &lu->orb_list) { orb->callback(orb, &status); @@ -480,18 +481,18 @@ static void complete_transaction(struct * been set and only does the cleanup if the transaction * failed and we didn't already get a status write. */ - spin_lock_irqsave(&card->lock, flags); + spin_lock_irqsave(&orb->lu->tgt->lock, flags); if (orb->rcode == -1) orb->rcode = rcode; if (orb->rcode != RCODE_COMPLETE) { list_del(&orb->link); - spin_unlock_irqrestore(&card->lock, flags); + spin_unlock_irqrestore(&orb->lu->tgt->lock, flags); orb->callback(orb, NULL); kref_put(&orb->kref, free_orb); /* orb callback reference */ } else { - spin_unlock_irqrestore(&card->lock, flags); + spin_unlock_irqrestore(&orb->lu->tgt->lock, flags); } kref_put(&orb->kref, free_orb); /* transaction callback reference */ @@ -507,9 +508,10 @@ static void sbp2_send_orb(struct sbp2_or orb_pointer.high = 0; orb_pointer.low = cpu_to_be32(orb->request_bus); - spin_lock_irqsave(&device->card->lock, flags); + orb->lu = lu; + spin_lock_irqsave(&lu->tgt->lock, flags); list_add_tail(&orb->link, &lu->orb_list); - spin_unlock_irqrestore(&device->card->lock, flags); + spin_unlock_irqrestore(&lu->tgt->lock, flags); kref_get(&orb->kref); /* transaction callback reference */ kref_get(&orb->kref); /* orb callback reference */ @@ -527,9 +529,9 @@ static int sbp2_cancel_orbs(struct sbp2_ int retval = -ENOENT; INIT_LIST_HEAD(&list); - spin_lock_irq(&device->card->lock); + spin_lock_irq(&lu->tgt->lock); list_splice_init(&lu->orb_list, &list); - spin_unlock_irq(&device->card->lock); + spin_unlock_irq(&lu->tgt->lock); list_for_each_entry_safe(orb, next, &list, link) { retval = 0; @@ -686,14 +688,11 @@ static void sbp2_agent_reset_no_wait(str &d, 4, complete_agent_reset_write_no_wait, t); } -static inline void sbp2_allow_block(struct sbp2_logical_unit *lu) +static inline void sbp2_allow_block(struct sbp2_target *tgt) { - struct sbp2_target *tgt = lu->tgt; - struct fw_card *card = target_parent_device(tgt)->card; - - spin_lock_irq(&card->lock); + spin_lock_irq(&tgt->lock); --tgt->dont_block; - spin_unlock_irq(&card->lock); + spin_unlock_irq(&tgt->lock); } /* @@ -702,7 +701,7 @@ static inline void sbp2_allow_block(stru * logical units have been finished (indicated by dont_block == 0). * - lu->generation is stale. * - * Note, scsi_block_requests() must be called while holding card->lock, + * Note, scsi_block_requests() must be called while holding tgt->lock, * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to * unblock the target. */ @@ -714,20 +713,20 @@ static void sbp2_conditionally_block(str container_of((void *)tgt, struct Scsi_Host, hostdata[0]); unsigned long flags; - spin_lock_irqsave(&card->lock, flags); + spin_lock_irqsave(&tgt->lock, flags); if (!tgt->dont_block && !lu->blocked && lu->generation != card->generation) { lu->blocked = true; if (++tgt->blocked == 1) scsi_block_requests(shost); } - spin_unlock_irqrestore(&card->lock, flags); + spin_unlock_irqrestore(&tgt->lock, flags); } /* * Unblocks lu->tgt as soon as all its logical units can be unblocked. * Note, it is harmless to run scsi_unblock_requests() outside the - * card->lock protected section. On the other hand, running it inside + * tgt->lock protected section. On the other hand, running it inside * the section might clash with shost->host_lock. */ static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu) @@ -738,12 +737,12 @@ static void sbp2_conditionally_unblock(s container_of((void *)tgt, struct Scsi_Host, hostdata[0]); bool unblock = false; - spin_lock_irq(&card->lock); + spin_lock_irq(&tgt->lock); if (lu->blocked && lu->generation == card->generation) { lu->blocked = false; unblock = --tgt->blocked == 0; } - spin_unlock_irq(&card->lock); + spin_unlock_irq(&tgt->lock); if (unblock) scsi_unblock_requests(shost); @@ -752,18 +751,17 @@ static void sbp2_conditionally_unblock(s /* * Prevents future blocking of tgt and unblocks it. * Note, it is harmless to run scsi_unblock_requests() outside the - * card->lock protected section. On the other hand, running it inside + * tgt->lock protected section. On the other hand, running it inside * the section might clash with shost->host_lock. */ static void sbp2_unblock(struct sbp2_target *tgt) { - struct fw_card *card = target_parent_device(tgt)->card; struct Scsi_Host *shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]); - spin_lock_irq(&card->lock); + spin_lock_irq(&tgt->lock); ++tgt->dont_block; - spin_unlock_irq(&card->lock); + spin_unlock_irq(&tgt->lock); scsi_unblock_requests(shost); } @@ -899,7 +897,7 @@ static void sbp2_login(struct work_struc /* No error during __scsi_add_device() */ lu->has_sdev = true; scsi_device_put(sdev); - sbp2_allow_block(lu); + sbp2_allow_block(tgt); return; @@ -1158,6 +1156,7 @@ static int sbp2_probe(struct fw_unit *un dev_set_drvdata(&unit->device, tgt); tgt->unit = unit; INIT_LIST_HEAD(&tgt->lu_list); + spin_lock_init(&tgt->lock); tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4]; if (fw_device_enable_phys_dma(device) < 0) @@ -1354,12 +1353,12 @@ static void complete_command_orb(struct { struct sbp2_command_orb *orb = container_of(base_orb, struct sbp2_command_orb, base); - struct fw_device *device = target_parent_device(orb->lu->tgt); + struct fw_device *device = target_parent_device(base_orb->lu->tgt); int result; if (status != NULL) { if (STATUS_GET_DEAD(*status)) - sbp2_agent_reset_no_wait(orb->lu); + sbp2_agent_reset_no_wait(base_orb->lu); switch (STATUS_GET_RESPONSE(*status)) { case SBP2_STATUS_REQUEST_COMPLETE: @@ -1385,7 +1384,7 @@ static void complete_command_orb(struct * or when sending the write (less likely). */ result = DID_BUS_BUSY << 16; - sbp2_conditionally_block(orb->lu); + sbp2_conditionally_block(base_orb->lu); } dma_unmap_single(device->card->device, orb->base.request_bus, @@ -1482,7 +1481,6 @@ static int sbp2_scsi_queuecommand(struct /* Initialize rcode to something not RCODE_COMPLETE. */ orb->base.rcode = -1; kref_init(&orb->base.kref); - orb->lu = lu; orb->cmd = cmd; orb->request.next.high = cpu_to_be32(SBP2_ORB_NULL); orb->request.misc = cpu_to_be32(