libata: switch to using block layer tagging support
libata currently has a pretty dumb ATA_MAX_QUEUE loop for finding
a free tag to use. Instead of fixing that up, convert libata to
using block layer tagging - gets rid of code in libata, and is also
much faster.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index bbb3cae..8cb0b36 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1713,8 +1713,6 @@
else
tag = 0;
- if (test_and_set_bit(tag, &ap->qc_allocated))
- BUG();
qc = __ata_qc_from_tag(ap, tag);
qc->tag = tag;
@@ -4553,37 +4551,6 @@
}
/**
- * ata_qc_new - Request an available ATA command, for queueing
- * @ap: Port associated with device @dev
- * @dev: Device from whom we request an available command structure
- *
- * LOCKING:
- * None.
- */
-
-static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
-{
- struct ata_queued_cmd *qc = NULL;
- unsigned int i;
-
- /* no command while frozen */
- if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
- return NULL;
-
- /* the last tag is reserved for internal command. */
- for (i = 0; i < ATA_MAX_QUEUE - 1; i++)
- if (!test_and_set_bit(i, &ap->qc_allocated)) {
- qc = __ata_qc_from_tag(ap, i);
- break;
- }
-
- if (qc)
- qc->tag = i;
-
- return qc;
-}
-
-/**
* ata_qc_new_init - Request an available ATA command, and initialize it
* @dev: Device from whom we request an available command structure
*
@@ -4591,16 +4558,20 @@
* None.
*/
-struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev)
+struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag)
{
struct ata_port *ap = dev->link->ap;
struct ata_queued_cmd *qc;
- qc = ata_qc_new(ap);
+ if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
+ return NULL;
+
+ qc = __ata_qc_from_tag(ap, tag);
if (qc) {
qc->scsicmd = NULL;
qc->ap = ap;
qc->dev = dev;
+ qc->tag = tag;
ata_qc_reinit(qc);
}
@@ -4608,31 +4579,6 @@
return qc;
}
-/**
- * ata_qc_free - free unused ata_queued_cmd
- * @qc: Command to complete
- *
- * Designed to free unused ata_queued_cmd object
- * in case something prevents using it.
- *
- * LOCKING:
- * spin_lock_irqsave(host lock)
- */
-void ata_qc_free(struct ata_queued_cmd *qc)
-{
- struct ata_port *ap = qc->ap;
- unsigned int tag;
-
- WARN_ON(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
-
- qc->flags = 0;
- tag = qc->tag;
- if (likely(ata_tag_valid(tag))) {
- qc->tag = ATA_TAG_POISON;
- clear_bit(tag, &ap->qc_allocated);
- }
-}
-
void __ata_qc_complete(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;