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Commit d737d7da authored by Stefan Richter's avatar Stefan Richter
Browse files

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: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent 8e045a31

drivers/firewire/sbp2.c

+29 −31
Original line number Diff line number Diff line
@@ -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_card *card, struct fw_request *request, 
	}



	/* 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_card *card, struct fw_request *request, 
			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 fw_card *card, int rcode, 
	 * 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_orb *orb, struct sbp2_logical_unit *lu, 
	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_logical_unit *lu) 
	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(struct sbp2_logical_unit *lu) 
			&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(struct sbp2_logical_unit *lu) 
 *     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(struct sbp2_logical_unit *lu) 
		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(struct sbp2_logical_unit *lu) 
		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(struct sbp2_logical_unit *lu) 
/*

 * 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_struct *work) 
	/* 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 *unit, const struct ieee1394_device_id *id) 
	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 sbp2_orb *base_orb, 
{

	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 sbp2_orb *base_orb, 
		 * 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 Scsi_Host *shost, 
	/* 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(