hpsa: avoid unnecessary readl on every command submission
for controllers which support either of the ioaccel transport methods.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: Mike Miller <michael.miller@canonical.com>
Reviewed-by: Joe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 3b70e66..3e501df 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -7330,6 +7330,13 @@
* 10 = 6 s/g entry or 24k
*/
+ /* If the controller supports either ioaccel method then
+ * we can also use the RAID stack submit path that does not
+ * perform the superfluous readl() after each command submission.
+ */
+ if (trans_support & (CFGTBL_Trans_io_accel1 | CFGTBL_Trans_io_accel2))
+ access = SA5_performant_access_no_read;
+
/* Controller spec: zero out this buffer. */
for (i = 0; i < h->nreply_queues; i++)
memset(h->reply_queue[i].head, 0, h->reply_queue_size);
diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
index 6da9a9f..0a5d91c 100644
--- a/drivers/scsi/hpsa.h
+++ b/drivers/scsi/hpsa.h
@@ -346,6 +346,12 @@
(void) readl(h->vaddr + SA5_SCRATCHPAD_OFFSET);
}
+static void SA5_submit_command_no_read(struct ctlr_info *h,
+ struct CommandList *c)
+{
+ writel(c->busaddr, h->vaddr + SA5_REQUEST_PORT_OFFSET);
+}
+
static void SA5_submit_command_ioaccel2(struct ctlr_info *h,
struct CommandList *c)
{
@@ -353,7 +359,6 @@
writel(c->busaddr, h->vaddr + IOACCEL2_INBOUND_POSTQ_32);
else
writel(c->busaddr, h->vaddr + SA5_REQUEST_PORT_OFFSET);
- (void) readl(h->vaddr + SA5_SCRATCHPAD_OFFSET);
}
/*
@@ -564,6 +569,14 @@
SA5_performant_completed,
};
+static struct access_method SA5_performant_access_no_read = {
+ SA5_submit_command_no_read,
+ SA5_performant_intr_mask,
+ SA5_fifo_full,
+ SA5_performant_intr_pending,
+ SA5_performant_completed,
+};
+
struct board_type {
u32 board_id;
char *product_name;