From 8e061784b51ec4a4efed0deaafb5bd9725bf5b06 Mon Sep 17 00:00:00 2001 From: Adam Manzanares Date: Mon, 17 Oct 2016 11:27:29 -0700 Subject: [PATCH] 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 Signed-off-by: Tejun Heo --- drivers/ata/libata-core.c | 35 ++++++++++++++++++++++++++++++++++- drivers/ata/libata-scsi.c | 6 +++++- drivers/ata/libata.h | 2 +- include/linux/ata.h | 6 ++++++ include/linux/libata.h | 3 +++ 5 files changed, 49 insertions(+), 3 deletions(-) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 223a770f78f3..8346faf63337 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -739,6 +739,7 @@ u64 ata_tf_read_block(const struct ata_taskfile *tf, struct ata_device *dev) * @n_block: Number of blocks * @tf_flags: RW/FUA etc... * @tag: tag + * @class: IO priority class * * LOCKING: * None. @@ -753,7 +754,7 @@ u64 ata_tf_read_block(const struct ata_taskfile *tf, struct ata_device *dev) */ 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) { tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE; tf->flags |= tf_flags; @@ -785,6 +786,12 @@ int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev, tf->device = ATA_LBA; if (tf->flags & ATA_TFLAG_FUA) tf->device |= 1 << 7; + + if (dev->flags & ATA_DFLAG_NCQ_PRIO) { + if (class == IOPRIO_CLASS_RT) + tf->hob_nsect |= ATA_PRIO_HIGH << + ATA_SHIFT_PRIO; + } } else if (dev->flags & ATA_DFLAG_LBA) { tf->flags |= ATA_TFLAG_LBA; @@ -2156,6 +2163,30 @@ static void ata_dev_config_ncq_non_data(struct ata_device *dev) } } +static void ata_dev_config_ncq_prio(struct ata_device *dev) +{ + struct ata_port *ap = dev->link->ap; + unsigned int err_mask; + + err_mask = ata_read_log_page(dev, + ATA_LOG_SATA_ID_DEV_DATA, + ATA_LOG_SATA_SETTINGS, + ap->sector_buf, + 1); + if (err_mask) { + ata_dev_dbg(dev, + "failed to get Identify Device data, Emask 0x%x\n", + err_mask); + return; + } + + if (ap->sector_buf[ATA_LOG_NCQ_PRIO_OFFSET] & BIT(3)) + dev->flags |= ATA_DFLAG_NCQ_PRIO; + else + ata_dev_dbg(dev, "SATA page does not support priority\n"); + +} + static int ata_dev_config_ncq(struct ata_device *dev, char *desc, size_t desc_sz) { @@ -2205,6 +2236,8 @@ static int ata_dev_config_ncq(struct ata_device *dev, ata_dev_config_ncq_send_recv(dev); if (ata_id_has_ncq_non_data(dev->id)) ata_dev_config_ncq_non_data(dev); + if (ata_id_has_ncq_prio(dev->id)) + ata_dev_config_ncq_prio(dev); } return 0; diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index 9cceb4a875a5..2bccc3c7de48 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -50,6 +50,7 @@ #include #include #include +#include #include "libata.h" #include "libata-transport.h" @@ -1755,6 +1756,8 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc) { struct scsi_cmnd *scmd = qc->scsicmd; const u8 *cdb = scmd->cmnd; + struct request *rq = scmd->request; + int class = IOPRIO_PRIO_CLASS(req_get_ioprio(rq)); unsigned int tf_flags = 0; u64 block; u32 n_block; @@ -1821,7 +1824,8 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc) qc->nbytes = n_block * scmd->device->sector_size; rc = ata_build_rw_tf(&qc->tf, qc->dev, block, n_block, tf_flags, - qc->tag); + qc->tag, class); + if (likely(rc == 0)) return 0; diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h index 3b301a48007c..8f3a5596dd67 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, diff --git a/include/linux/ata.h b/include/linux/ata.h index fdb180367ba1..af6859b3a93d 100644 --- a/include/linux/ata.h +++ b/include/linux/ata.h @@ -348,6 +348,7 @@ enum { ATA_LOG_DEVSLP_DETO = 0x01, ATA_LOG_DEVSLP_VALID = 0x07, ATA_LOG_DEVSLP_VALID_MASK = 0x80, + ATA_LOG_NCQ_PRIO_OFFSET = 0x09, /* NCQ send and receive log */ ATA_LOG_NCQ_SEND_RECV_SUBCMDS_OFFSET = 0x00, @@ -940,6 +941,11 @@ static inline bool ata_id_has_ncq_non_data(const u16 *id) return id[ATA_ID_SATA_CAPABILITY_2] & BIT(5); } +static inline bool ata_id_has_ncq_prio(const u16 *id) +{ + return id[ATA_ID_SATA_CAPABILITY] & BIT(12); +} + static inline bool ata_id_has_trim(const u16 *id) { if (ata_id_major_version(id) >= 7 && 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, -- 2.39.5