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| author | Adam Manzanares <adam.manzanares@hgst.com> | 2016-10-17 21:27:29 +0300 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2016-10-19 21:34:36 +0300 |
| commit | 8e061784b51ec4a4efed0deaafb5bd9725bf5b06 (patch) | |
| tree | 30d253d6d6a214f6514484bfe1d2c3b178fdf62e /include/linux/libata.h | |
| parent | 5dc8b362a2374d007bc0db649b7ab6a79dd32bda (diff) | |
| download | linux-8e061784b51ec4a4efed0deaafb5bd9725bf5b06.tar.xz | |
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>
Diffstat (limited to 'include/linux/libata.h')
| -rw-r--r-- | include/linux/libata.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/libata.h b/include/linux/libata.h index 616eef4d81ea..90b69a6293a3 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -166,6 +166,7 @@ enum { ATA_DFLAG_NO_UNLOAD = (1 << 17), /* device doesn't support unload */ ATA_DFLAG_UNLOCK_HPA = (1 << 18), /* unlock HPA */ ATA_DFLAG_NCQ_SEND_RECV = (1 << 19), /* device supports NCQ SEND and RECV */ + ATA_DFLAG_NCQ_PRIO = (1 << 20), /* device supports NCQ priority */ ATA_DFLAG_INIT_MASK = (1 << 24) - 1, ATA_DFLAG_DETACH = (1 << 24), @@ -342,7 +343,9 @@ enum { ATA_SHIFT_PIO = 0, ATA_SHIFT_MWDMA = ATA_SHIFT_PIO + ATA_NR_PIO_MODES, ATA_SHIFT_UDMA = ATA_SHIFT_MWDMA + ATA_NR_MWDMA_MODES, + ATA_SHIFT_PRIO = 6, + ATA_PRIO_HIGH = 2, /* size of buffer to pad xfers ending on unaligned boundaries */ ATA_DMA_PAD_SZ = 4, |