[SCSI] hpsa: refine interrupt handler locking for greater concurrency
Use spinlocks with finer granularity in the submission and
completion paths to allow concurrent execution for multiple
reply queues. In particular, do not hold a spin lock while
submitting a request to the device, nor during most of the
interrupt handler.
Signed-off-by: Matt Gates <matthew.gates@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
index 486a7c0..79c36aa 100644
--- a/drivers/scsi/hpsa.h
+++ b/drivers/scsi/hpsa.h
@@ -246,9 +246,6 @@
c->Header.Tag.lower);
writel(c->busaddr, h->vaddr + SA5_REQUEST_PORT_OFFSET);
(void) readl(h->vaddr + SA5_SCRATCHPAD_OFFSET);
- h->commands_outstanding++;
- if (h->commands_outstanding > h->max_outstanding)
- h->max_outstanding = h->commands_outstanding;
}
/*
@@ -287,7 +284,7 @@
static unsigned long SA5_performant_completed(struct ctlr_info *h, u8 q)
{
struct reply_pool *rq = &h->reply_queue[q];
- unsigned long register_value = FIFO_EMPTY;
+ unsigned long flags, register_value = FIFO_EMPTY;
/* msi auto clears the interrupt pending bit. */
if (!(h->msi_vector || h->msix_vector)) {
@@ -305,7 +302,9 @@
if ((rq->head[rq->current_entry] & 1) == rq->wraparound) {
register_value = rq->head[rq->current_entry];
rq->current_entry++;
+ spin_lock_irqsave(&h->lock, flags);
h->commands_outstanding--;
+ spin_unlock_irqrestore(&h->lock, flags);
} else {
register_value = FIFO_EMPTY;
}
@@ -338,9 +337,13 @@
{
unsigned long register_value
= readl(h->vaddr + SA5_REPLY_PORT_OFFSET);
+ unsigned long flags;
- if (register_value != FIFO_EMPTY)
+ if (register_value != FIFO_EMPTY) {
+ spin_lock_irqsave(&h->lock, flags);
h->commands_outstanding--;
+ spin_unlock_irqrestore(&h->lock, flags);
+ }
#ifdef HPSA_DEBUG
if (register_value != FIFO_EMPTY)