Commit 0b57075d authored by Stephen M. Cameron's avatar Stephen M. Cameron Committed by Christoph Hellwig
Browse files

hpsa: Rearrange start_io to avoid one unlock/lock sequence in main io path 



Signed-off-by: default avatarStephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: default avatarJoe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent b3a52e79

drivers/scsi/hpsa.c

+16 −8
Original line number Diff line number Diff line
@@ -194,7 +194,8 @@ static int number_of_controllers; 
static irqreturn_t do_hpsa_intr_intx(int irq, void *dev_id);

static irqreturn_t do_hpsa_intr_msi(int irq, void *dev_id);

static int hpsa_ioctl(struct scsi_device *dev, int cmd, void *arg);

static void start_io(struct ctlr_info *h);

static void lock_and_start_io(struct ctlr_info *h);

static void start_io(struct ctlr_info *h, unsigned long *flags);



#ifdef CONFIG_COMPAT

static int hpsa_compat_ioctl(struct scsi_device *dev, int cmd, void *arg);
@@ -845,8 +846,8 @@ static void enqueue_cmd_and_start_io(struct ctlr_info *h, 
	spin_lock_irqsave(&h->lock, flags);

	addQ(&h->reqQ, c);

	h->Qdepth++;

	start_io(h, &flags);

	spin_unlock_irqrestore(&h->lock, flags);

	start_io(h);

}



static inline void removeQ(struct CommandList *c)
@@ -5459,13 +5460,12 @@ static void __iomem *remap_pci_mem(ulong base, ulong size) 


/* Takes cmds off the submission queue and sends them to the hardware,

 * then puts them on the queue of cmds waiting for completion.

 * Assumes h->lock is held

 */

static void start_io(struct ctlr_info *h)

static void start_io(struct ctlr_info *h, unsigned long *flags)

{

	struct CommandList *c;

	unsigned long flags;



	spin_lock_irqsave(&h->lock, flags);

	while (!list_empty(&h->reqQ)) {

		c = list_entry(h->reqQ.next, struct CommandList, list);

		/* can't do anything if fifo is full */
@@ -5490,10 +5490,18 @@ static void start_io(struct ctlr_info *h) 
		h->commands_outstanding++;



		/* Tell the controller execute command */

		spin_unlock_irqrestore(&h->lock, flags);

		spin_unlock_irqrestore(&h->lock, *flags);

		h->access.submit_command(h, c);

		spin_lock_irqsave(&h->lock, flags);

		spin_lock_irqsave(&h->lock, *flags);

	}

}



static void lock_and_start_io(struct ctlr_info *h)

{

	unsigned long flags;



	spin_lock_irqsave(&h->lock, flags);

	start_io(h, &flags);

	spin_unlock_irqrestore(&h->lock, flags);

}
@@ -5561,7 +5569,7 @@ static inline void finish_cmd(struct CommandList *c) 
	else if (c->cmd_type == CMD_IOCTL_PEND)

		complete(c->waiting);

	if (unlikely(io_may_be_stalled))

		start_io(h);

		lock_and_start_io(h);

}



static inline u32 hpsa_tag_contains_index(u32 tag)