ata: Enabling ATA Command Priorities
This patch checks to see if an ATA device supports NCQ command priorities.
If so and the user has specified an iocontext that indicates
IO_PRIO_CLASS_RT then we build a tf with a high priority command.
This is done to improve the tail latency of commands that are high
priority by passing priority to the device.
tj: Removed trivial ata_ncq_prio_enabled() and open-coded the test.
Signed-off-by: Adam Manzanares <adam.manzanares@hgst.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 3b301a4..8f3a559 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -66,7 +66,7 @@ extern u64 ata_tf_to_lba48(const struct ata_taskfile *tf);
extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag);
extern int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
u64 block, u32 n_block, unsigned int tf_flags,
- unsigned int tag);
+ unsigned int tag, int class);
extern u64 ata_tf_read_block(const struct ata_taskfile *tf,
struct ata_device *dev);
extern unsigned ata_exec_internal(struct ata_device *dev,