[PATCH 09/30] scsi: kill off the legacy IO path

Jens Axboe
2018-10-31T17:59:01Z

Cc: linux-scsi@vger.kernel.org
Acked-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
Documentation/scsi/scsi-parameters.txt | 5 -
drivers/scsi/Kconfig | 12 -
drivers/scsi/cxlflash/main.c | 6 -
drivers/scsi/hosts.c | 29 +-
drivers/scsi/lpfc/lpfc_scsi.c | 2 +-
drivers/scsi/qedi/qedi_main.c | 3 +-
drivers/scsi/qla2xxx/qla_os.c | 30 +-
drivers/scsi/scsi.c | 5 +-
drivers/scsi/scsi_debug.c | 3 +-
drivers/scsi/scsi_error.c | 2 +-
drivers/scsi/scsi_lib.c | 603 ++-----------------------
drivers/scsi/scsi_priv.h | 1 -
drivers/scsi/scsi_scan.c | 10 +-
drivers/scsi/scsi_sysfs.c | 8 +-
drivers/scsi/ufs/ufshcd.c | 6 -
include/scsi/scsi_host.h | 18 +-
include/scsi/scsi_tcq.h | 14 +-
17 files changed, 77 insertions(+), 680 deletions(-)

diff --git a/Documentation/scsi/scsi-parameters.txt b/Documentation/scsi/scsi-parameters.txt
index 92999d4e0cb8..25a4b4cf04a6 100644
--- a/Documentation/scsi/scsi-parameters.txt
+++ b/Documentation/scsi/scsi-parameters.txt
@@ -97,11 +97,6 @@ parameters may be changed at runtime by the command
allowing boot to proceed. none ignores them, expecting
user space to do the scan.

- scsi_mod.use_blk_mq=
- [SCSI] use blk-mq I/O path by default
- See SCSI_MQ_DEFAULT in drivers/scsi/Kconfig.
- Format: <y/n>
-
sim710= [SCSI,HW]
See header of drivers/scsi/sim710.c.

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 70988c381268..ff5a569fdbcb 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -50,18 +50,6 @@ config SCSI_NETLINK
default n
depends on NET

-config SCSI_MQ_DEFAULT
- bool "SCSI: use blk-mq I/O path by default"
- default y
- depends on SCSI
- ---help---
- This option enables the blk-mq based I/O path for SCSI devices by
- default. With this option the scsi_mod.use_blk_mq module/boot
- option defaults to Y, without it to N, but it can still be
- overridden either way.
-
- If unsure say Y.
-
config SCSI_PROC_FS
bool "legacy /proc/scsi/ support"
depends on SCSI && PROC_FS
diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index 6637116529aa..abdc9eac4173 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -3088,12 +3088,6 @@ static ssize_t hwq_mode_store(struct device *dev,
return -EINVAL;
}

- if ((mode == HWQ_MODE_TAG) && !shost_use_blk_mq(shost)) {
- dev_info(cfgdev, "SCSI-MQ is not enabled, use a different "
- "HWQ steering mode.\n");
- return -EINVAL;
- }
-
afu->hwq_mode = mode;

return count;
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index ea4b0bb0c1cd..cc71136ba300 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -222,18 +222,9 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
if (error)
goto fail;

- if (shost_use_blk_mq(shost)) {
- error = scsi_mq_setup_tags(shost);
- if (error)
- goto fail;
- } else {
- shost->bqt = blk_init_tags(shost->can_queue,
- shost->hostt->tag_alloc_policy);
- if (!shost->bqt) {
- error = -ENOMEM;
- goto fail;
- }
- }
+ error = scsi_mq_setup_tags(shost);
+ if (error)
+ goto fail;

if (!shost->shost_gendev.parent)
shost->shost_gendev.parent = dev ? dev : &platform_bus;
@@ -309,8 +300,7 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
pm_runtime_disable(&shost->shost_gendev);
pm_runtime_set_suspended(&shost->shost_gendev);
pm_runtime_put_noidle(&shost->shost_gendev);
- if (shost_use_blk_mq(shost))
- scsi_mq_destroy_tags(shost);
+ scsi_mq_destroy_tags(shost);
fail:
return error;
}
@@ -344,13 +334,8 @@ static void scsi_host_dev_release(struct device *dev)
kfree(dev_name(&shost->shost_dev));
}

- if (shost_use_blk_mq(shost)) {
- if (shost->tag_set.tags)
- scsi_mq_destroy_tags(shost);
- } else {
- if (shost->bqt)
- blk_free_tags(shost->bqt);
- }
+ if (shost->tag_set.tags)
+ scsi_mq_destroy_tags(shost);

kfree(shost->shost_data);

@@ -472,8 +457,6 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
else
shost->dma_boundary = 0xffffffff;

- shost->use_blk_mq = scsi_use_blk_mq || shost->hostt->force_blk_mq;
-
device_initialize(&shost->shost_gendev);
dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
shost->shost_gendev.bus = &scsi_bus_type;
diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index 4fa6703a9ec9..baed2b891efb 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -3914,7 +3914,7 @@ int lpfc_sli4_scmd_to_wqidx_distr(struct lpfc_hba *phba,
uint32_t tag;
uint16_t hwq;

- if (cmnd && shost_use_blk_mq(cmnd->device->host)) {
+ if (cmnd) {
tag = blk_mq_unique_tag(cmnd->request);
hwq = blk_mq_unique_tag_to_hwq(tag);

diff --git a/drivers/scsi/qedi/qedi_main.c b/drivers/scsi/qedi/qedi_main.c
index 105b0e4d7818..311eb22068e1 100644
--- a/drivers/scsi/qedi/qedi_main.c
+++ b/drivers/scsi/qedi/qedi_main.c
@@ -644,8 +644,7 @@ static struct qedi_ctx *qedi_host_alloc(struct pci_dev *pdev)
qedi->max_active_conns = ISCSI_MAX_SESS_PER_HBA;
qedi->max_sqes = QEDI_SQ_SIZE;

- if (shost_use_blk_mq(shost))
- shost->nr_hw_queues = MIN_NUM_CPUS_MSIX(qedi);
+ shost->nr_hw_queues = MIN_NUM_CPUS_MSIX(qedi);

pci_set_drvdata(pdev, qedi);

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 8794e54f43a9..3e2665c66bc4 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -857,13 +857,9 @@ qla2xxx_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
}

if (ha->mqenable) {
- if (shost_use_blk_mq(vha->host)) {
- tag = blk_mq_unique_tag(cmd->request);
- hwq = blk_mq_unique_tag_to_hwq(tag);
- qpair = ha->queue_pair_map[hwq];
- } else if (vha->vp_idx && vha->qpair) {
- qpair = vha->qpair;
- }
+ tag = blk_mq_unique_tag(cmd->request);
+ hwq = blk_mq_unique_tag_to_hwq(tag);
+ qpair = ha->queue_pair_map[hwq];

if (qpair)
return qla2xxx_mqueuecommand(host, cmd, qpair);
@@ -3153,7 +3149,7 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
goto probe_failed;
}

- if (ha->mqenable && shost_use_blk_mq(host)) {
+ if (ha->mqenable) {
/* number of hardware queues supported by blk/scsi-mq*/
host->nr_hw_queues = ha->max_qpairs;

@@ -3265,25 +3261,17 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
base_vha->mgmt_svr_loop_id, host->sg_tablesize);

if (ha->mqenable) {
- bool mq = false;
bool startit = false;

- if (QLA_TGT_MODE_ENABLED()) {
- mq = true;
+ if (QLA_TGT_MODE_ENABLED())
startit = false;
- }

- if ((ql2x_ini_mode == QLA2XXX_INI_MODE_ENABLED) &&
- shost_use_blk_mq(host)) {
- mq = true;
+ if (ql2x_ini_mode == QLA2XXX_INI_MODE_ENABLED)
startit = true;
- }

- if (mq) {
- /* Create start of day qpairs for Block MQ */
- for (i = 0; i < ha->max_qpairs; i++)
- qla2xxx_create_qpair(base_vha, 5, 0, startit);
- }
+ /* Create start of day qpairs for Block MQ */
+ for (i = 0; i < ha->max_qpairs; i++)
+ qla2xxx_create_qpair(base_vha, 5, 0, startit);
}

if (ha->flags.running_gold_fw)
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index fc1356d101b0..99db3f4316b5 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -780,11 +780,8 @@ MODULE_LICENSE("GPL");
module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");

-#ifdef CONFIG_SCSI_MQ_DEFAULT
+/* Kill module parameter */
bool scsi_use_blk_mq = true;
-#else
-bool scsi_use_blk_mq = false;
-#endif
module_param_named(use_blk_mq, scsi_use_blk_mq, bool, S_IWUSR | S_IRUGO);

static int __init init_scsi(void)
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 60bcc6df97a9..4740f1e9dd17 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -5881,8 +5881,7 @@ static int sdebug_driver_probe(struct device *dev)
}
/* Decide whether to tell scsi subsystem that we want mq */
/* Following should give the same answer for each host */
- if (shost_use_blk_mq(hpnt))
- hpnt->nr_hw_queues = submit_queues;
+ hpnt->nr_hw_queues = submit_queues;

sdbg_host->shost = hpnt;
*((struct sdebug_host_info **)hpnt->hostdata) = sdbg_host;
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index c736d61b1648..fff128aa9ec2 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -308,7 +308,7 @@ enum blk_eh_timer_return scsi_times_out(struct request *req)
* error handler. In that case we can return immediately as no
* further action is required.
*/
- if (req->q->mq_ops && !blk_mq_mark_complete(req))
+ if (!blk_mq_mark_complete(req))
return rtn;
if (scsi_abort_command(scmd) != SUCCESS) {
set_host_byte(scmd, DID_TIME_OUT);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 8b0345924a92..651be30ba96a 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -168,8 +168,6 @@ static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd)
static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy)
{
struct scsi_device *device = cmd->device;
- struct request_queue *q = device->request_queue;
- unsigned long flags;

SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd,
"Inserting command %p into mlqueue\n", cmd));
@@ -190,26 +188,20 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy)
* before blk_cleanup_queue() finishes.
*/
cmd->result = 0;
- if (q->mq_ops) {
- /*
- * Before a SCSI command is dispatched,
- * get_device(&sdev->sdev_gendev) is called and the host,
- * target and device busy counters are increased. Since
- * requeuing a request causes these actions to be repeated and
- * since scsi_device_unbusy() has already been called,
- * put_device(&device->sdev_gendev) must still be called. Call
- * put_device() after blk_mq_requeue_request() to avoid that
- * removal of the SCSI device can start before requeueing has
- * happened.
- */
- blk_mq_requeue_request(cmd->request, true);
- put_device(&device->sdev_gendev);
- return;
- }
- spin_lock_irqsave(q->queue_lock, flags);
- blk_requeue_request(q, cmd->request);
- kblockd_schedule_work(&device->requeue_work);
- spin_unlock_irqrestore(q->queue_lock, flags);
+
+ /*
+ * Before a SCSI command is dispatched,
+ * get_device(&sdev->sdev_gendev) is called and the host,
+ * target and device busy counters are increased. Since
+ * requeuing a request causes these actions to be repeated and
+ * since scsi_device_unbusy() has already been called,
+ * put_device(&device->sdev_gendev) must still be called. Call
+ * put_device() after blk_mq_requeue_request() to avoid that
+ * removal of the SCSI device can start before requeueing has
+ * happened.
+ */
+ blk_mq_requeue_request(cmd->request, true);
+ put_device(&device->sdev_gendev);
}

/*
@@ -370,10 +362,7 @@ void scsi_device_unbusy(struct scsi_device *sdev)

static void scsi_kick_queue(struct request_queue *q)
{
- if (q->mq_ops)
- blk_mq_run_hw_queues(q, false);
- else
- blk_run_queue(q);
+ blk_mq_run_hw_queues(q, false);
}

/*
@@ -534,10 +523,7 @@ static void scsi_run_queue(struct request_queue *q)
if (!list_empty(&sdev->host->starved_list))
scsi_starved_list_run(sdev->host);

- if (q->mq_ops)
- blk_mq_run_hw_queues(q, false);
- else
- blk_run_queue(q);
+ blk_mq_run_hw_queues(q, false);
}

void scsi_requeue_run_queue(struct work_struct *work)
@@ -550,42 +536,6 @@ void scsi_requeue_run_queue(struct work_struct *work)
scsi_run_queue(q);
}

-/*
- * Function: scsi_requeue_command()
- *
- * Purpose: Handle post-processing of completed commands.
- *
- * Arguments: q - queue to operate on
- * cmd - command that may need to be requeued.
- *
- * Returns: Nothing
- *
- * Notes: After command completion, there may be blocks left
- * over which weren't finished by the previous command
- * this can be for a number of reasons - the main one is
- * I/O errors in the middle of the request, in which case
- * we need to request the blocks that come after the bad
- * sector.
- * Notes: Upon return, cmd is a stale pointer.
- */
-static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd)
-{
- struct scsi_device *sdev = cmd->device;
- struct request *req = cmd->request;
- unsigned long flags;
-
- spin_lock_irqsave(q->queue_lock, flags);
- blk_unprep_request(req);
- req->special = NULL;
- scsi_put_command(cmd);
- blk_requeue_request(q, req);
- spin_unlock_irqrestore(q->queue_lock, flags);
-
- scsi_run_queue(q);
-
- put_device(&sdev->sdev_gendev);
-}
-
void scsi_run_host_queues(struct Scsi_Host *shost)
{
struct scsi_device *sdev;
@@ -626,42 +576,6 @@ static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
scsi_del_cmd_from_list(cmd);
}

-/*
- * Function: scsi_release_buffers()
- *
- * Purpose: Free resources allocate for a scsi_command.
- *
- * Arguments: cmd - command that we are bailing.
- *
- * Lock status: Assumed that no lock is held upon entry.
- *
- * Returns: Nothing
- *
- * Notes: In the event that an upper level driver rejects a
- * command, we must release resources allocated during
- * the __init_io() function. Primarily this would involve
- * the scatter-gather table.
- */
-static void scsi_release_buffers(struct scsi_cmnd *cmd)
-{
- if (cmd->sdb.table.nents)
- sg_free_table_chained(&cmd->sdb.table, false);
-
- memset(&cmd->sdb, 0, sizeof(cmd->sdb));
-
- if (scsi_prot_sg_count(cmd))
- sg_free_table_chained(&cmd->prot_sdb->table, false);
-}
-
-static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd)
-{
- struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special;
-
- sg_free_table_chained(&bidi_sdb->table, false);
- kmem_cache_free(scsi_sdb_cache, bidi_sdb);
- cmd->request->next_rq->special = NULL;
-}
-
/* Returns false when no more bytes to process, true if there are more */
static bool scsi_end_request(struct request *req, blk_status_t error,
unsigned int bytes, unsigned int bidi_bytes)
@@ -687,37 +601,22 @@ static bool scsi_end_request(struct request *req, blk_status_t error,
destroy_rcu_head(&cmd->rcu);
}

- if (req->mq_ctx) {
- /*
- * In the MQ case the command gets freed by __blk_mq_end_request,
- * so we have to do all cleanup that depends on it earlier.
- *
- * We also can't kick the queues from irq context, so we
- * will have to defer it to a workqueue.
- */
- scsi_mq_uninit_cmd(cmd);
-
- __blk_mq_end_request(req, error);
-
- if (scsi_target(sdev)->single_lun ||
- !list_empty(&sdev->host->starved_list))
- kblockd_schedule_work(&sdev->requeue_work);
- else
- blk_mq_run_hw_queues(q, true);
- } else {
- unsigned long flags;
-
- if (bidi_bytes)
- scsi_release_bidi_buffers(cmd);
- scsi_release_buffers(cmd);
- scsi_put_command(cmd);
+ /*
+ * In the MQ case the command gets freed by __blk_mq_end_request,
+ * so we have to do all cleanup that depends on it earlier.
+ *
+ * We also can't kick the queues from irq context, so we
+ * will have to defer it to a workqueue.
+ */
+ scsi_mq_uninit_cmd(cmd);

- spin_lock_irqsave(q->queue_lock, flags);
- blk_finish_request(req, error);
- spin_unlock_irqrestore(q->queue_lock, flags);
+ __blk_mq_end_request(req, error);

- scsi_run_queue(q);
- }
+ if (scsi_target(sdev)->single_lun ||
+ !list_empty(&sdev->host->starved_list))
+ kblockd_schedule_work(&sdev->requeue_work);
+ else
+ blk_mq_run_hw_queues(q, true);

put_device(&sdev->sdev_gendev);
return false;
@@ -766,13 +665,7 @@ static void scsi_io_completion_reprep(struct scsi_cmnd *cmd,
struct request_queue *q)
{
/* A new command will be prepared and issued. */
- if (q->mq_ops) {
- scsi_mq_requeue_cmd(cmd);
- } else {
- /* Unprep request and put it back at head of the queue. */
- scsi_release_buffers(cmd);
- scsi_requeue_command(q, cmd);
- }
+ scsi_mq_requeue_cmd(cmd);
}

/* Helper for scsi_io_completion() when special action required. */
@@ -1147,9 +1040,7 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)
*/
int scsi_init_io(struct scsi_cmnd *cmd)
{
- struct scsi_device *sdev = cmd->device;
struct request *rq = cmd->request;
- bool is_mq = (rq->mq_ctx != NULL);
int error = BLKPREP_KILL;

if (WARN_ON_ONCE(!blk_rq_nr_phys_segments(rq)))
@@ -1160,17 +1051,6 @@ int scsi_init_io(struct scsi_cmnd *cmd)
goto err_exit;

if (blk_bidi_rq(rq)) {
- if (!rq->q->mq_ops) {
- struct scsi_data_buffer *bidi_sdb =
- kmem_cache_zalloc(scsi_sdb_cache, GFP_ATOMIC);
- if (!bidi_sdb) {
- error = BLKPREP_DEFER;
- goto err_exit;
- }
-
- rq->next_rq->special = bidi_sdb;
- }
-
error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special);
if (error)
goto err_exit;
@@ -1210,14 +1090,7 @@ int scsi_init_io(struct scsi_cmnd *cmd)

return BLKPREP_OK;
err_exit:
- if (is_mq) {
- scsi_mq_free_sgtables(cmd);
- } else {
- scsi_release_buffers(cmd);
- cmd->request->special = NULL;
- scsi_put_command(cmd);
- put_device(&sdev->sdev_gendev);
- }
+ scsi_mq_free_sgtables(cmd);
return error;
}
EXPORT_SYMBOL(scsi_init_io);
@@ -1423,75 +1296,6 @@ scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
return ret;
}

-static int
-scsi_prep_return(struct request_queue *q, struct request *req, int ret)
-{
- struct scsi_device *sdev = q->queuedata;
-
- switch (ret) {
- case BLKPREP_KILL:
- case BLKPREP_INVALID:
- scsi_req(req)->result = DID_NO_CONNECT << 16;
- /* release the command and kill it */
- if (req->special) {
- struct scsi_cmnd *cmd = req->special;
- scsi_release_buffers(cmd);
- scsi_put_command(cmd);
- put_device(&sdev->sdev_gendev);
- req->special = NULL;
- }
- break;
- case BLKPREP_DEFER:
- /*
- * If we defer, the blk_peek_request() returns NULL, but the
- * queue must be restarted, so we schedule a callback to happen
- * shortly.
- */
- if (atomic_read(&sdev->device_busy) == 0)
- blk_delay_queue(q, SCSI_QUEUE_DELAY);
- break;
- default:
- req->rq_flags |= RQF_DONTPREP;
- }
-
- return ret;
-}
-
-static int scsi_prep_fn(struct request_queue *q, struct request *req)
-{
- struct scsi_device *sdev = q->queuedata;
- struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
- int ret;
-
- ret = scsi_prep_state_check(sdev, req);
- if (ret != BLKPREP_OK)
- goto out;
-
- if (!req->special) {
- /* Bail if we can't get a reference to the device */
- if (unlikely(!get_device(&sdev->sdev_gendev))) {
- ret = BLKPREP_DEFER;
- goto out;
- }
-
- scsi_init_command(sdev, cmd);
- req->special = cmd;
- }
-
- cmd->tag = req->tag;
- cmd->request = req;
- cmd->prot_op = SCSI_PROT_NORMAL;
-
- ret = scsi_setup_cmnd(sdev, req);
-out:
- return scsi_prep_return(q, req, ret);
-}
-
-static void scsi_unprep_fn(struct request_queue *q, struct request *req)
-{
- scsi_uninit_cmd(blk_mq_rq_to_pdu(req));
-}
-
/*
* scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
* return 0.
@@ -1511,14 +1315,8 @@ static inline int scsi_dev_queue_ready(struct request_queue *q,
/*
* unblock after device_blocked iterates to zero
*/
- if (atomic_dec_return(&sdev->device_blocked) > 0) {
- /*
- * For the MQ case we take care of this in the caller.
- */
- if (!q->mq_ops)
- blk_delay_queue(q, SCSI_QUEUE_DELAY);
+ if (atomic_dec_return(&sdev->device_blocked) > 0)
goto out_dec;
- }
SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev,
"unblocking device at zero depth\n"));
}
@@ -1653,13 +1451,13 @@ static inline int scsi_host_queue_ready(struct request_queue *q,
* needs to return 'not busy'. Otherwise, request stacking drivers
* may hold requests forever.
*/
-static int scsi_lld_busy(struct request_queue *q)
+static bool scsi_mq_lld_busy(struct request_queue *q)
{
struct scsi_device *sdev = q->queuedata;
struct Scsi_Host *shost;

if (blk_queue_dying(q))
- return 0;
+ return false;

shost = sdev->host;

@@ -1670,48 +1468,9 @@ static int scsi_lld_busy(struct request_queue *q)
* in SCSI layer.
*/
if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev))
- return 1;
-
- return 0;
-}
-
-static bool scsi_mq_lld_busy(struct request_queue *q)
-{
- return scsi_lld_busy(q);
-}
-
-/*
- * Kill a request for a dead device
- */
-static void scsi_kill_request(struct request *req, struct request_queue *q)
-{
- struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
- struct scsi_device *sdev;
- struct scsi_target *starget;
- struct Scsi_Host *shost;
-
- blk_start_request(req);
-
- scmd_printk(KERN_INFO, cmd, "killing request\n");
-
- sdev = cmd->device;
- starget = scsi_target(sdev);
- shost = sdev->host;
- scsi_init_cmd_errh(cmd);
- cmd->result = DID_NO_CONNECT << 16;
- atomic_inc(&cmd->device->iorequest_cnt);
-
- /*
- * SCSI request completion path will do scsi_device_unbusy(),
- * bump busy counts. To bump the counters, we need to dance
- * with the locks as normal issue path does.
- */
- atomic_inc(&sdev->device_busy);
- atomic_inc(&shost->host_busy);
- if (starget->can_queue > 0)
- atomic_inc(&starget->target_busy);
+ return true;

- blk_complete_request(req);
+ return false;
}

static void scsi_softirq_done(struct request *rq)
@@ -1834,158 +1593,6 @@ static int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
return 0;
}

-/**
- * scsi_done - Invoke completion on finished SCSI command.
- * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
- * ownership back to SCSI Core -- i.e. the LLDD has finished with it.
- *
- * Description: This function is the mid-level's (SCSI Core) interrupt routine,
- * which regains ownership of the SCSI command (de facto) from a LLDD, and
- * calls blk_complete_request() for further processing.
- *
- * This function is interrupt context safe.
- */
-static void scsi_done(struct scsi_cmnd *cmd)
-{
- trace_scsi_dispatch_cmd_done(cmd);
- blk_complete_request(cmd->request);
-}
-
-/*
- * Function: scsi_request_fn()
- *
- * Purpose: Main strategy routine for SCSI.
- *
- * Arguments: q - Pointer to actual queue.
- *
- * Returns: Nothing
- *
- * Lock status: request queue lock assumed to be held when called.
- *
- * Note: See sd_zbc.c sd_zbc_write_lock_zone() for write order
- * protection for ZBC disks.
- */
-static void scsi_request_fn(struct request_queue *q)
- __releases(q->queue_lock)
- __acquires(q->queue_lock)
-{
- struct scsi_device *sdev = q->queuedata;
- struct Scsi_Host *shost;
- struct scsi_cmnd *cmd;
- struct request *req;
-
- /*
- * To start with, we keep looping until the queue is empty, or until
- * the host is no longer able to accept any more requests.
- */
- shost = sdev->host;
- for (;;) {
- int rtn;
- /*
- * get next queueable request. We do this early to make sure
- * that the request is fully prepared even if we cannot
- * accept it.
- */
- req = blk_peek_request(q);
- if (!req)
- break;
-
- if (unlikely(!scsi_device_online(sdev))) {
- sdev_printk(KERN_ERR, sdev,
- "rejecting I/O to offline device\n");
- scsi_kill_request(req, q);
- continue;
- }
-
- if (!scsi_dev_queue_ready(q, sdev))
- break;
-
- /*
- * Remove the request from the request list.
- */
- if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req)))
- blk_start_request(req);
-
- spin_unlock_irq(q->queue_lock);
- cmd = blk_mq_rq_to_pdu(req);
- if (cmd != req->special) {
- printk(KERN_CRIT "impossible request in %s.\n"
- "please mail a stack trace to "
- "linux-scsi@vger.kernel.org\n",
- __func__);
- blk_dump_rq_flags(req, "foo");
- BUG();
- }
-
- /*
- * We hit this when the driver is using a host wide
- * tag map. For device level tag maps the queue_depth check
- * in the device ready fn would prevent us from trying
- * to allocate a tag. Since the map is a shared host resource
- * we add the dev to the starved list so it eventually gets
- * a run when a tag is freed.
- */
- if (blk_queue_tagged(q) && !(req->rq_flags & RQF_QUEUED)) {
- spin_lock_irq(shost->host_lock);
- if (list_empty(&sdev->starved_entry))
- list_add_tail(&sdev->starved_entry,
- &shost->starved_list);
- spin_unlock_irq(shost->host_lock);
- goto not_ready;
- }
-
- if (!scsi_target_queue_ready(shost, sdev))
- goto not_ready;
-
- if (!scsi_host_queue_ready(q, shost, sdev))
- goto host_not_ready;
-
- if (sdev->simple_tags)
- cmd->flags |= SCMD_TAGGED;
- else
- cmd->flags &= ~SCMD_TAGGED;
-
- /*
- * Finally, initialize any error handling parameters, and set up
- * the timers for timeouts.
- */
- scsi_init_cmd_errh(cmd);
-
- /*
- * Dispatch the command to the low-level driver.
- */
- cmd->scsi_done = scsi_done;
- rtn = scsi_dispatch_cmd(cmd);
- if (rtn) {
- scsi_queue_insert(cmd, rtn);
- spin_lock_irq(q->queue_lock);
- goto out_delay;
- }
- spin_lock_irq(q->queue_lock);
- }
-
- return;
-
- host_not_ready:
- if (scsi_target(sdev)->can_queue > 0)
- atomic_dec(&scsi_target(sdev)->target_busy);
- not_ready:
- /*
- * lock q, handle tag, requeue req, and decrement device_busy. We
- * must return with queue_lock held.
- *
- * Decrementing device_busy without checking it is OK, as all such
- * cases (host limits or settings) should run the queue at some
- * later time.
- */
- spin_lock_irq(q->queue_lock);
- blk_requeue_request(q, req);
- atomic_dec(&sdev->device_busy);
-out_delay:
- if (!atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev))
- blk_delay_queue(q, SCSI_QUEUE_DELAY);
-}
-
static inline blk_status_t prep_to_mq(int ret)
{
switch (ret) {
@@ -2248,77 +1855,6 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)
}
EXPORT_SYMBOL_GPL(__scsi_init_queue);

-static int scsi_old_init_rq(struct request_queue *q, struct request *rq,
- gfp_t gfp)
-{
- struct Scsi_Host *shost = q->rq_alloc_data;
- const bool unchecked_isa_dma = shost->unchecked_isa_dma;
- struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
-
- memset(cmd, 0, sizeof(*cmd));
-
- if (unchecked_isa_dma)
- cmd->flags |= SCMD_UNCHECKED_ISA_DMA;
- cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma, gfp,
- NUMA_NO_NODE);
- if (!cmd->sense_buffer)
- goto fail;
- cmd->req.sense = cmd->sense_buffer;
-
- if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) {
- cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp);
- if (!cmd->prot_sdb)
- goto fail_free_sense;
- }
-
- return 0;
-
-fail_free_sense:
- scsi_free_sense_buffer(unchecked_isa_dma, cmd->sense_buffer);
-fail:
- return -ENOMEM;
-}
-
-static void scsi_old_exit_rq(struct request_queue *q, struct request *rq)
-{
- struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
-
- if (cmd->prot_sdb)
- kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
- scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA,
- cmd->sense_buffer);
-}
-
-struct request_queue *scsi_old_alloc_queue(struct scsi_device *sdev)
-{
- struct Scsi_Host *shost = sdev->host;
- struct request_queue *q;
-
- q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE, NULL);
- if (!q)
- return NULL;
- q->cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
- q->rq_alloc_data = shost;
- q->request_fn = scsi_request_fn;
- q->init_rq_fn = scsi_old_init_rq;
- q->exit_rq_fn = scsi_old_exit_rq;
- q->initialize_rq_fn = scsi_initialize_rq;
-
- if (blk_init_allocated_queue(q) < 0) {
- blk_cleanup_queue(q);
- return NULL;
- }
-
- __scsi_init_queue(shost, q);
- blk_queue_flag_set(QUEUE_FLAG_SCSI_PASSTHROUGH, q);
- blk_queue_prep_rq(q, scsi_prep_fn);
- blk_queue_unprep_rq(q, scsi_unprep_fn);
- blk_queue_softirq_done(q, scsi_softirq_done);
- blk_queue_rq_timed_out(q, scsi_times_out);
- blk_queue_lld_busy(q, scsi_lld_busy);
- return q;
-}
-
static const struct blk_mq_ops scsi_mq_ops = {
.get_budget = scsi_mq_get_budget,
.put_budget = scsi_mq_put_budget,
@@ -2386,10 +1922,7 @@ struct scsi_device *scsi_device_from_queue(struct request_queue *q)
{
struct scsi_device *sdev = NULL;

- if (q->mq_ops) {
- if (q->mq_ops == &scsi_mq_ops)
- sdev = q->queuedata;
- } else if (q->request_fn == scsi_request_fn)
+ if (q->mq_ops == &scsi_mq_ops)
sdev = q->queuedata;
if (!sdev || !get_device(&sdev->sdev_gendev))
sdev = NULL;
@@ -2992,39 +2525,6 @@ void sdev_evt_send_simple(struct scsi_device *sdev,
}
EXPORT_SYMBOL_GPL(sdev_evt_send_simple);

-/**
- * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()
- * @sdev: SCSI device to count the number of scsi_request_fn() callers for.
- */
-static int scsi_request_fn_active(struct scsi_device *sdev)
-{
- struct request_queue *q = sdev->request_queue;
- int request_fn_active;
-
- WARN_ON_ONCE(sdev->host->use_blk_mq);
-
- spin_lock_irq(q->queue_lock);
- request_fn_active = q->request_fn_active;
- spin_unlock_irq(q->queue_lock);
-
- return request_fn_active;
-}
-
-/**
- * scsi_wait_for_queuecommand() - wait for ongoing queuecommand() calls
- * @sdev: SCSI device pointer.
- *
- * Wait until the ongoing shost->hostt->queuecommand() calls that are
- * invoked from scsi_request_fn() have finished.
- */
-static void scsi_wait_for_queuecommand(struct scsi_device *sdev)
-{
- WARN_ON_ONCE(sdev->host->use_blk_mq);
-
- while (scsi_request_fn_active(sdev))
- msleep(20);
-}
-
/**
* scsi_device_quiesce - Block user issued commands.
* @sdev: scsi device to quiesce.
@@ -3148,7 +2648,6 @@ EXPORT_SYMBOL(scsi_target_resume);
int scsi_internal_device_block_nowait(struct scsi_device *sdev)
{
struct request_queue *q = sdev->request_queue;
- unsigned long flags;
int err = 0;

err = scsi_device_set_state(sdev, SDEV_BLOCK);
@@ -3164,14 +2663,7 @@ int scsi_internal_device_block_nowait(struct scsi_device *sdev)
* block layer from calling the midlayer with this device's
* request queue.
*/
- if (q->mq_ops) {
- blk_mq_quiesce_queue_nowait(q);
- } else {
- spin_lock_irqsave(q->queue_lock, flags);
- blk_stop_queue(q);
- spin_unlock_irqrestore(q->queue_lock, flags);
- }
-
+ blk_mq_quiesce_queue_nowait(q);
return 0;
}
EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
@@ -3202,12 +2694,8 @@ static int scsi_internal_device_block(struct scsi_device *sdev)

mutex_lock(&sdev->state_mutex);
err = scsi_internal_device_block_nowait(sdev);
- if (err == 0) {
- if (q->mq_ops)
- blk_mq_quiesce_queue(q);
- else
- scsi_wait_for_queuecommand(sdev);
- }
+ if (err == 0)
+ blk_mq_quiesce_queue(q);
mutex_unlock(&sdev->state_mutex);

return err;
@@ -3216,15 +2704,8 @@ static int scsi_internal_device_block(struct scsi_device *sdev)
void scsi_start_queue(struct scsi_device *sdev)
{
struct request_queue *q = sdev->request_queue;
- unsigned long flags;

- if (q->mq_ops) {
- blk_mq_unquiesce_queue(q);
- } else {
- spin_lock_irqsave(q->queue_lock, flags);
- blk_start_queue(q);
- spin_unlock_irqrestore(q->queue_lock, flags);
- }
+ blk_mq_unquiesce_queue(q);
}

/**
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index 99f1db5e467e..5f21547b2ad2 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -92,7 +92,6 @@ extern void scsi_queue_insert(struct scsi_cmnd *cmd, int reason);
extern void scsi_io_completion(struct scsi_cmnd *, unsigned int);
extern void scsi_run_host_queues(struct Scsi_Host *shost);
extern void scsi_requeue_run_queue(struct work_struct *work);
-extern struct request_queue *scsi_old_alloc_queue(struct scsi_device *sdev);
extern struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev);
extern void scsi_start_queue(struct scsi_device *sdev);
extern int scsi_mq_setup_tags(struct Scsi_Host *shost);
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 78ca63dfba4a..dd0d516f65e2 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -266,10 +266,7 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
*/
sdev->borken = 1;

- if (shost_use_blk_mq(shost))
- sdev->request_queue = scsi_mq_alloc_queue(sdev);
- else
- sdev->request_queue = scsi_old_alloc_queue(sdev);
+ sdev->request_queue = scsi_mq_alloc_queue(sdev);
if (!sdev->request_queue) {
/* release fn is set up in scsi_sysfs_device_initialise, so
* have to free and put manually here */
@@ -280,11 +277,6 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
WARN_ON_ONCE(!blk_get_queue(sdev->request_queue));
sdev->request_queue->queuedata = sdev;

- if (!shost_use_blk_mq(sdev->host)) {
- blk_queue_init_tags(sdev->request_queue,
- sdev->host->cmd_per_lun, shost->bqt,
- shost->hostt->tag_alloc_policy);
- }
scsi_change_queue_depth(sdev, sdev->host->cmd_per_lun ?
sdev->host->cmd_per_lun : 1);

diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 3aee9464a7bf..12e2c2829df2 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -367,7 +367,6 @@ store_shost_eh_deadline(struct device *dev, struct device_attribute *attr,

static DEVICE_ATTR(eh_deadline, S_IRUGO | S_IWUSR, show_shost_eh_deadline, store_shost_eh_deadline);

-shost_rd_attr(use_blk_mq, "%d\n");
shost_rd_attr(unique_id, "%u\n");
shost_rd_attr(cmd_per_lun, "%hd\n");
shost_rd_attr(can_queue, "%hd\n");
@@ -386,6 +385,13 @@ show_host_busy(struct device *dev, struct device_attribute *attr, char *buf)
}
static DEVICE_ATTR(host_busy, S_IRUGO, show_host_busy, NULL);

+static ssize_t
+show_use_blk_mq(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return snprintf(buf, 20, "1\n");
+}
+static DEVICE_ATTR(use_blk_mq, S_IRUGO, show_use_blk_mq, NULL);
+
static struct attribute *scsi_sysfs_shost_attrs[] = {
&dev_attr_use_blk_mq.attr,
&dev_attr_unique_id.attr,
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 23d7cca36ff0..fb308ea8e9a5 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8100,12 +8100,6 @@ int ufshcd_alloc_host(struct device *dev, struct ufs_hba **hba_handle)
goto out_error;
}

- /*
- * Do not use blk-mq at this time because blk-mq does not support
- * runtime pm.
- */
- host->use_blk_mq = false;
-
hba = shost_priv(host);
hba->host = host;
hba->dev = dev;
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 5ea06d310a25..aa760df8c6b3 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -11,7 +11,6 @@
#include <linux/blk-mq.h>
#include <scsi/scsi.h>

-struct request_queue;
struct block_device;
struct completion;
struct module;
@@ -22,7 +21,6 @@ struct scsi_target;
struct Scsi_Host;
struct scsi_host_cmd_pool;
struct scsi_transport_template;
-struct blk_queue_tags;

/*
@@ -547,14 +545,8 @@ struct Scsi_Host {
struct scsi_host_template *hostt;
struct scsi_transport_template *transportt;

- /*
- * Area to keep a shared tag map (if needed, will be
- * NULL if not).
- */
- union {
- struct blk_queue_tag *bqt;
- struct blk_mq_tag_set tag_set;
- };
+ /* Area to keep a shared tag map */
+ struct blk_mq_tag_set tag_set;

atomic_t host_busy; /* commands actually active on low-level */
atomic_t host_blocked;
@@ -648,7 +640,6 @@ struct Scsi_Host {
/* The controller does not support WRITE SAME */
unsigned no_write_same:1;

- unsigned use_blk_mq:1;
unsigned use_cmd_list:1;

/* Host responded with short (<36 bytes) INQUIRY result */
@@ -742,11 +733,6 @@ static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
shost->tmf_in_progress;
}

-static inline bool shost_use_blk_mq(struct Scsi_Host *shost)
-{
- return shost->use_blk_mq;
-}
-
extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
extern void scsi_flush_work(struct Scsi_Host *);

diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index e192a0caa850..6053d46e794e 100644
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -23,19 +23,15 @@ static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost,
int tag)
{
struct request *req = NULL;
+ u16 hwq;

if (tag == SCSI_NO_TAG)
return NULL;

- if (shost_use_blk_mq(shost)) {
- u16 hwq = blk_mq_unique_tag_to_hwq(tag);
-
- if (hwq < shost->tag_set.nr_hw_queues) {
- req = blk_mq_tag_to_rq(shost->tag_set.tags[hwq],
- blk_mq_unique_tag_to_tag(tag));
- }
- } else {
- req = blk_map_queue_find_tag(shost->bqt, tag);
+ hwq = blk_mq_unique_tag_to_hwq(tag);
+ if (hwq < shost->tag_set.nr_hw_queues) {
+ req = blk_mq_tag_to_rq(shost->tag_set.tags[hwq],
+ blk_mq_unique_tag_to_tag(tag));
}

if (!req)
--
2.17.1