libata: add extra internal command
Bump the internal tag to 32, instead of stealing the last tag in
our regular command space. This works just fine, since we don't
actually need a separate hardware tag for this. Internal commands
cannot coexist with NCQ commands.
As a bonus, we get rid of the special casing of what tag to use
for the internal command.
This is in preparation for utilizing all 32 commands for normal IO.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 60ce1ba..1d02671 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -125,9 +125,8 @@ enum {
LIBATA_MAX_PRD = ATA_MAX_PRD / 2,
LIBATA_DUMB_MAX_PRD = ATA_MAX_PRD / 4, /* Worst case */
ATA_DEF_QUEUE = 1,
- /* tag ATA_MAX_QUEUE - 1 is reserved for internal commands */
ATA_MAX_QUEUE = 32,
- ATA_TAG_INTERNAL = ATA_MAX_QUEUE - 1,
+ ATA_TAG_INTERNAL = ATA_MAX_QUEUE,
ATA_SHORT_PAUSE = 16,
ATAPI_MAX_DRAIN = 16 << 10,
@@ -850,7 +849,7 @@ struct ata_port {
unsigned int udma_mask;
unsigned int cbl; /* cable type; ATA_CBL_xxx */
- struct ata_queued_cmd qcmd[ATA_MAX_QUEUE];
+ struct ata_queued_cmd qcmd[ATA_MAX_QUEUE + 1];
unsigned long sas_tag_allocated; /* for sas tag allocation only */
u64 qc_active;
int nr_active_links; /* #links with active qcs */
@@ -1486,16 +1485,16 @@ extern void ata_port_pbar_desc(struct ata_port *ap, int bar, ssize_t offset,
const char *name);
#endif
-static inline unsigned int ata_tag_valid(unsigned int tag)
-{
- return (tag < ATA_MAX_QUEUE) ? 1 : 0;
-}
-
static inline bool ata_tag_internal(unsigned int tag)
{
return tag == ATA_TAG_INTERNAL;
}
+static inline bool ata_tag_valid(unsigned int tag)
+{
+ return tag < ATA_MAX_QUEUE || ata_tag_internal(tag);
+}
+
/*
* device helpers
*/
@@ -1656,7 +1655,7 @@ static inline void ata_qc_set_polling(struct ata_queued_cmd *qc)
static inline struct ata_queued_cmd *__ata_qc_from_tag(struct ata_port *ap,
unsigned int tag)
{
- if (likely(ata_tag_valid(tag)))
+ if (ata_tag_valid(tag))
return &ap->qcmd[tag];
return NULL;
}