From: Bart Van Assche <bart.vanassche@wdc.com>
Date: Thu, 17 Aug 2017 13:13:32 -0700
Subject: [PATCH] skd: Convert to blk-mq
Git-commit: ca33dd92968bac6aae0ecd56bc8962b4a97492f1
Patch-mainline: v4.14-rc1
References: bsc#1104967,FATE#325924
Introduce a tag set and a blk_mq_ops structure. Set .cmd_size such
that struct request and struct skd_request_context are allocated
through a single allocation. Remove the skd_request_context.req
pointer. Make queue starting asynchronous such that this can occur
safely from interrupt context. Use locking to protect skdev->skmsg
and *skdev->skmsg against concurrent access from concurrent
.queue_rq() calls. Introduce the functions skd_init_request() and
skd_exit_request() to set up / clean up the per-request S/G-list.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
drivers/block/skd_main.c | 229 +++++++++++++++++++----------------------------
1 file changed, 91 insertions(+), 138 deletions(-)
diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
index dad623659fae..3590f9a775ae 100644
--- a/drivers/block/skd_main.c
+++ b/drivers/block/skd_main.c
@@ -230,6 +230,7 @@ struct skd_device {
spinlock_t lock;
struct gendisk *disk;
+ struct blk_mq_tag_set tag_set;
struct request_queue *queue;
struct skd_fitmsg_context *skmsg;
struct device *class_dev;
@@ -287,6 +288,7 @@ struct skd_device {
u32 timo_slot;
+ struct work_struct start_queue;
struct work_struct completion_worker;
};
@@ -371,7 +373,6 @@ static void skd_send_fitmsg(struct skd_device *skdev,
struct skd_fitmsg_context *skmsg);
static void skd_send_special_fitmsg(struct skd_device *skdev,
struct skd_special_context *skspcl);
-static void skd_request_fn(struct request_queue *rq);
static void skd_end_request(struct skd_device *skdev, struct request *req,
blk_status_t status);
static bool skd_preop_sg_list(struct skd_device *skdev,
@@ -398,20 +399,6 @@ static void skd_log_skreq(struct skd_device *skdev,
* READ/WRITE REQUESTS
*****************************************************************************
*/
-static void skd_fail_all_pending(struct skd_device *skdev)
-{
- struct request_queue *q = skdev->queue;
- struct request *req;
-
- for (;; ) {
- req = blk_peek_request(q);
- if (req == NULL)
- break;
- WARN_ON_ONCE(blk_queue_start_tag(q, req));
- __blk_end_request_all(req, BLK_STS_IOERR);
- }
-}
-
static void
skd_prep_rw_cdb(struct skd_scsi_request *scsi_req,
int data_dir, unsigned lba,
@@ -490,7 +477,7 @@ static bool skd_fail_all(struct request_queue *q)
}
}
-static void skd_process_request(struct request *req)
+static void skd_process_request(struct request *req, bool last)
{
struct request_queue *const q = req->q;
struct skd_device *skdev = q->queuedata;
@@ -499,6 +486,7 @@ static void skd_process_request(struct request *req)
const u32 tag = blk_mq_unique_tag(req);
struct skd_request_context *const skreq = blk_mq_rq_to_pdu(req);
struct skd_scsi_request *scsi_req;
+ unsigned long flags;
unsigned long io_flags;
u32 lba;
u32 count;
@@ -545,6 +533,7 @@ static void skd_process_request(struct request *req)
return;
}
+ spin_lock_irqsave(&skdev->lock, flags);
/* Either a FIT msg is in progress or we have to start one. */
skmsg = skdev->skmsg;
if (!skmsg) {
@@ -602,83 +591,30 @@ static void skd_process_request(struct request *req)
/*
* If the FIT msg buffer is full send it.
*/
- if (fmh->num_protocol_cmds_coalesced >= skd_max_req_per_msg) {
+ if (last || fmh->num_protocol_cmds_coalesced >= skd_max_req_per_msg) {
skd_send_fitmsg(skdev, skmsg);
skdev->skmsg = NULL;
}
+ spin_unlock_irqrestore(&skdev->lock, flags);
}
-static void skd_request_fn(struct request_queue *q)
+static blk_status_t skd_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *mqd)
{
+ struct request *req = mqd->rq;
+ struct request_queue *q = req->q;
struct skd_device *skdev = q->queuedata;
- struct request *req;
-
- if (skdev->state != SKD_DRVR_STATE_ONLINE) {
- if (skd_fail_all(q))
- skd_fail_all_pending(skdev);
- return;
- }
-
- if (blk_queue_stopped(skdev->queue)) {
- if (atomic_read(&skdev->in_flight) >=
- skdev->queue_low_water_mark)
- /* There is still some kind of shortage */
- return;
-
- queue_flag_clear(QUEUE_FLAG_STOPPED, skdev->queue);
- }
-
- /*
- * Stop conditions:
- * - There are no more native requests
- * - There are already the maximum number of requests in progress
- * - There are no more skd_request_context entries
- * - There are no more FIT msg buffers
- */
- for (;; ) {
- req = blk_peek_request(q);
-
- /* Are there any native requests to start? */
- if (req == NULL)
- break;
-
- /* At this point we know there is a request */
-
- /* Are too many requets already in progress? */
- if (atomic_read(&skdev->in_flight) >=
- skdev->cur_max_queue_depth) {
- dev_dbg(&skdev->pdev->dev, "qdepth %d, limit %d\n",
- atomic_read(&skdev->in_flight),
- skdev->cur_max_queue_depth);
- break;
- }
-
- /*
- * OK to now dequeue request from q.
- *
- * At this point we are comitted to either start or reject
- * the native request. Note that skd_request_context is
- * available but is still at the head of the free list.
- */
- WARN_ON_ONCE(blk_queue_start_tag(q, req));
- skd_process_request(req);
- }
- /* If the FIT msg buffer is not empty send what we got. */
- if (skdev->skmsg) {
- struct fit_msg_hdr *fmh = &skdev->skmsg->msg_buf->fmh;
+ if (skdev->state == SKD_DRVR_STATE_ONLINE) {
+ blk_mq_start_request(req);
+ skd_process_request(req, mqd->last);
- WARN_ON_ONCE(!fmh->num_protocol_cmds_coalesced);
- skd_send_fitmsg(skdev, skdev->skmsg);
- skdev->skmsg = NULL;
+ return BLK_STS_OK;
+ } else {
+ return skd_fail_all(q) ? BLK_STS_IOERR : BLK_STS_RESOURCE;
}
- /*
- * If req is non-NULL it means there is something to do but
- * we are out of a resource.
- */
- if (req)
- blk_stop_queue(skdev->queue);
+ return BLK_STS_OK;
}
static void skd_end_request(struct skd_device *skdev, struct request *req,
@@ -696,7 +632,7 @@ static void skd_end_request(struct skd_device *skdev, struct request *req,
dev_dbg(&skdev->pdev->dev, "id=0x%x error=%d\n", req->tag,
error);
- __blk_end_request_all(req, error);
+ blk_mq_end_request(req, error);
}
static bool skd_preop_sg_list(struct skd_device *skdev,
@@ -781,6 +717,19 @@ static void skd_postop_sg_list(struct skd_device *skdev,
static void skd_timer_tick_not_online(struct skd_device *skdev);
+static void skd_start_queue(struct work_struct *work)
+{
+ struct skd_device *skdev = container_of(work, typeof(*skdev),
+ start_queue);
+
+ /*
+ * Although it is safe to call blk_start_queue() from interrupt
+ * context, blk_mq_start_hw_queues() must not be called from
+ * interrupt context.
+ */
+ blk_mq_start_hw_queues(skdev->queue);
+}
+
static void skd_timer_tick(ulong arg)
{
struct skd_device *skdev = (struct skd_device *)arg;
@@ -886,7 +835,7 @@ static void skd_timer_tick_not_online(struct skd_device *skdev)
/*start the queue so we can respond with error to requests */
/* wakeup anyone waiting for startup complete */
- blk_start_queue(skdev->queue);
+ schedule_work(&skdev->start_queue);
skdev->gendisk_on = -1;
wake_up_interruptible(&skdev->waitq);
break;
@@ -961,7 +910,7 @@ static void skd_timer_tick_not_online(struct skd_device *skdev)
/*start the queue so we can respond with error to requests */
/* wakeup anyone waiting for startup complete */
- blk_start_queue(skdev->queue);
+ schedule_work(&skdev->start_queue);
skdev->gendisk_on = -1;
wake_up_interruptible(&skdev->waitq);
break;
@@ -1543,7 +1492,6 @@ static void skd_resolve_req_exception(struct skd_device *skdev,
}
}
-/* assume spinlock is already held */
static void skd_release_skreq(struct skd_device *skdev,
struct skd_request_context *skreq)
{
@@ -1574,6 +1522,7 @@ static int skd_isr_completion_posted(struct skd_device *skdev,
struct fit_comp_error_info *skerr;
u16 req_id;
u32 tag;
+ u16 hwq = 0;
struct request *rq;
struct skd_request_context *skreq;
u16 cmp_cntxt;
@@ -1629,13 +1578,13 @@ static int skd_isr_completion_posted(struct skd_device *skdev,
/*
* This is not a completion for a r/w request.
*/
- WARN_ON_ONCE(blk_map_queue_find_tag(skdev->queue->
- queue_tags, tag));
+ WARN_ON_ONCE(blk_mq_tag_to_rq(skdev->tag_set.tags[hwq],
+ tag));
skd_complete_other(skdev, skcmp, skerr);
continue;
}
- rq = blk_map_queue_find_tag(skdev->queue->queue_tags, tag);
+ rq = blk_mq_tag_to_rq(skdev->tag_set.tags[hwq], tag);
if (WARN(!rq, "No request for tag %#x -> %#x\n", cmp_cntxt,
tag))
continue;
@@ -1789,7 +1738,7 @@ static void skd_completion_worker(struct work_struct *work)
* process everything in compq
*/
skd_isr_completion_posted(skdev, 0, &flush_enqueued);
- blk_run_queue_async(skdev->queue);
+ schedule_work(&skdev->start_queue);
spin_unlock_irqrestore(&skdev->lock, flags);
}
@@ -1865,12 +1814,12 @@ skd_isr(int irq, void *ptr)
}
if (unlikely(flush_enqueued))
- blk_run_queue_async(skdev->queue);
+ schedule_work(&skdev->start_queue);
if (deferred)
schedule_work(&skdev->completion_worker);
else if (!flush_enqueued)
- blk_run_queue_async(skdev->queue);
+ schedule_work(&skdev->start_queue);
spin_unlock(&skdev->lock);
@@ -1953,7 +1902,7 @@ static void skd_isr_fwstate(struct skd_device *skdev)
*/
skdev->state = SKD_DRVR_STATE_BUSY_SANITIZE;
skdev->timer_countdown = SKD_TIMER_SECONDS(3);
- blk_start_queue(skdev->queue);
+ schedule_work(&skdev->start_queue);
break;
case FIT_SR_DRIVE_BUSY_ERASE:
skdev->state = SKD_DRVR_STATE_BUSY_ERASE;
@@ -1987,7 +1936,7 @@ static void skd_isr_fwstate(struct skd_device *skdev)
case FIT_SR_DRIVE_FAULT:
skd_drive_fault(skdev);
skd_recover_requests(skdev);
- blk_start_queue(skdev->queue);
+ schedule_work(&skdev->start_queue);
break;
/* PCIe bus returned all Fs? */
@@ -1996,7 +1945,7 @@ static void skd_isr_fwstate(struct skd_device *skdev)
sense);
skd_drive_disappeared(skdev);
skd_recover_requests(skdev);
- blk_start_queue(skdev->queue);
+ schedule_work(&skdev->start_queue);
break;
default:
/*
@@ -2009,18 +1958,16 @@ static void skd_isr_fwstate(struct skd_device *skdev)
skd_skdev_state_to_str(skdev->state), skdev->state);
}
-static void skd_recover_request(struct skd_device *skdev,
- struct skd_request_context *skreq)
+static void skd_recover_request(struct request *req, void *data, bool reserved)
{
- struct request *req = blk_mq_rq_from_pdu(skreq);
+ struct skd_device *const skdev = data;
+ struct skd_request_context *skreq = blk_mq_rq_to_pdu(req);
if (skreq->state != SKD_REQ_STATE_BUSY)
return;
skd_log_skreq(skdev, skreq, "recover");
- SKD_ASSERT(req != NULL);
-
/* Release DMA resources for the request. */
if (skreq->n_sg > 0)
skd_postop_sg_list(skdev, skreq);
@@ -2034,15 +1981,7 @@ static void skd_recover_requests(struct skd_device *skdev)
{
int i;
- for (i = 0; i < skdev->num_req_context; i++) {
- struct request *rq = blk_map_queue_find_tag(skdev->queue->
- queue_tags, i);
- struct skd_request_context *skreq = blk_mq_rq_to_pdu(rq);
-
- if (!rq)
- continue;
- skd_recover_request(skdev, skreq);
- }
+ blk_mq_tagset_busy_iter(&skdev->tag_set, skd_recover_request, skdev);
for (i = 0; i < SKD_N_TIMEOUT_SLOT; i++)
atomic_set(&skdev->timeout_slot[i], 0);
@@ -2263,7 +2202,7 @@ static void skd_start_device(struct skd_device *skdev)
skd_drive_fault(skdev);
/*start the queue so we can respond with error to requests */
dev_dbg(&skdev->pdev->dev, "starting queue\n");
- blk_start_queue(skdev->queue);
+ schedule_work(&skdev->start_queue);
skdev->gendisk_on = -1;
wake_up_interruptible(&skdev->waitq);
break;
@@ -2275,7 +2214,7 @@ static void skd_start_device(struct skd_device *skdev)
/*start the queue so we can respond with error to requests */
dev_dbg(&skdev->pdev->dev,
"starting queue to error-out reqs\n");
- blk_start_queue(skdev->queue);
+ schedule_work(&skdev->start_queue);
skdev->gendisk_on = -1;
wake_up_interruptible(&skdev->waitq);
break;
@@ -2408,7 +2347,7 @@ static int skd_quiesce_dev(struct skd_device *skdev)
case SKD_DRVR_STATE_BUSY:
case SKD_DRVR_STATE_BUSY_IMMINENT:
dev_dbg(&skdev->pdev->dev, "stopping queue\n");
- blk_stop_queue(skdev->queue);
+ blk_mq_stop_hw_queues(skdev->queue);
break;
case SKD_DRVR_STATE_ONLINE:
case SKD_DRVR_STATE_STOPPING:
@@ -2473,7 +2412,7 @@ static int skd_unquiesce_dev(struct skd_device *skdev)
"**** device ONLINE...starting block queue\n");
dev_dbg(&skdev->pdev->dev, "starting queue\n");
dev_info(&skdev->pdev->dev, "STEC s1120 ONLINE\n");
- blk_start_queue(skdev->queue);
+ schedule_work(&skdev->start_queue);
skdev->gendisk_on = 1;
wake_up_interruptible(&skdev->waitq);
break;
@@ -2537,12 +2476,12 @@ static irqreturn_t skd_comp_q(int irq, void *skd_host_data)
deferred = skd_isr_completion_posted(skdev, skd_isr_comp_limit,
&flush_enqueued);
if (flush_enqueued)
- blk_run_queue_async(skdev->queue);
+ schedule_work(&skdev->start_queue);
if (deferred)
schedule_work(&skdev->completion_worker);
else if (!flush_enqueued)
- blk_run_queue_async(skdev->queue);
+ schedule_work(&skdev->start_queue);
spin_unlock_irqrestore(&skdev->lock, flags);
@@ -2843,9 +2782,10 @@ static void skd_free_sg_list(struct skd_device *skdev,
pci_free_consistent(skdev->pdev, nbytes, sg_list, dma_addr);
}
-static int skd_init_rq(struct request_queue *q, struct request *rq, gfp_t gfp)
+static int skd_init_request(struct blk_mq_tag_set *set, struct request *rq,
+ unsigned int hctx_idx, unsigned int numa_node)
{
- struct skd_device *skdev = q->queuedata;
+ struct skd_device *skdev = set->driver_data;
struct skd_request_context *skreq = blk_mq_rq_to_pdu(rq);
skreq->state = SKD_REQ_STATE_IDLE;
@@ -2857,9 +2797,10 @@ static int skd_init_rq(struct request_queue *q, struct request *rq, gfp_t gfp)
return skreq->sksg_list ? 0 : -ENOMEM;
}
-static void skd_exit_rq(struct request_queue *q, struct request *rq)
+static void skd_exit_request(struct blk_mq_tag_set *set, struct request *rq,
+ unsigned int hctx_idx)
{
- struct skd_device *skdev = q->queuedata;
+ struct skd_device *skdev = set->driver_data;
struct skd_request_context *skreq = blk_mq_rq_to_pdu(rq);
skd_free_sg_list(skdev, skreq->sksg_list,
@@ -2911,6 +2852,12 @@ static int skd_cons_sksb(struct skd_device *skdev)
return rc;
}
+static const struct blk_mq_ops skd_mq_ops = {
+ .queue_rq = skd_mq_queue_rq,
+ .init_request = skd_init_request,
+ .exit_request = skd_exit_request,
+};
+
static int skd_cons_disk(struct skd_device *skdev)
{
int rc = 0;
@@ -2932,27 +2879,30 @@ static int skd_cons_disk(struct skd_device *skdev)
disk->fops = &skd_blockdev_ops;
disk->private_data = skdev;
- q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE);
+ q = NULL;
+ memset(&skdev->tag_set, 0, sizeof(skdev->tag_set));
+ skdev->tag_set.ops = &skd_mq_ops;
+ skdev->tag_set.nr_hw_queues = 1;
+ skdev->tag_set.queue_depth = skd_max_queue_depth;
+ skdev->tag_set.cmd_size = sizeof(struct skd_request_context) +
+ skdev->sgs_per_request * sizeof(struct scatterlist);
+ skdev->tag_set.numa_node = NUMA_NO_NODE;
+ skdev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE |
+ BLK_MQ_F_SG_MERGE |
+ BLK_ALLOC_POLICY_TO_MQ_FLAG(BLK_TAG_ALLOC_FIFO);
+ skdev->tag_set.driver_data = skdev;
+ if (blk_mq_alloc_tag_set(&skdev->tag_set) >= 0) {
+ q = blk_mq_init_queue(&skdev->tag_set);
+ if (!q)
+ blk_mq_free_tag_set(&skdev->tag_set);
+ }
if (!q) {
rc = -ENOMEM;
goto err_out;
}
blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
q->queuedata = skdev;
- q->request_fn = skd_request_fn;
- q->queue_lock = &skdev->lock;
q->nr_requests = skd_max_queue_depth / 2;
- q->cmd_size = sizeof(struct skd_request_context) +
- skdev->sgs_per_request * sizeof(struct scatterlist);
- q->init_rq_fn = skd_init_rq;
- q->exit_rq_fn = skd_exit_rq;
- rc = blk_init_allocated_queue(q);
- if (rc < 0)
- goto cleanup_q;
- rc = blk_queue_init_tags(q, skd_max_queue_depth, NULL,
- BLK_TAG_ALLOC_FIFO);
- if (rc < 0)
- goto cleanup_q;
skdev->queue = q;
disk->queue = q;
@@ -2969,15 +2919,11 @@ static int skd_cons_disk(struct skd_device *skdev)
spin_lock_irqsave(&skdev->lock, flags);
dev_dbg(&skdev->pdev->dev, "stopping queue\n");
- blk_stop_queue(skdev->queue);
+ blk_mq_stop_hw_queues(skdev->queue);
spin_unlock_irqrestore(&skdev->lock, flags);
err_out:
return rc;
-
-cleanup_q:
- blk_cleanup_queue(q);
- goto err_out;
}
#define SKD_N_DEV_TABLE 16u
@@ -3012,6 +2958,7 @@ static struct skd_device *skd_construct(struct pci_dev *pdev)
spin_lock_init(&skdev->lock);
+ INIT_WORK(&skdev->start_queue, skd_start_queue);
INIT_WORK(&skdev->completion_worker, skd_completion_worker);
dev_dbg(&skdev->pdev->dev, "skcomp\n");
@@ -3130,6 +3077,9 @@ static void skd_free_disk(struct skd_device *skdev)
disk->queue = NULL;
}
+ if (skdev->tag_set.tags)
+ blk_mq_free_tag_set(&skdev->tag_set);
+
put_disk(disk);
skdev->disk = NULL;
}
@@ -3139,6 +3089,8 @@ static void skd_destruct(struct skd_device *skdev)
if (skdev == NULL)
return;
+ cancel_work_sync(&skdev->start_queue);
+
dev_dbg(&skdev->pdev->dev, "disk\n");
skd_free_disk(skdev);
@@ -3682,6 +3634,7 @@ static void skd_log_skreq(struct skd_device *skdev,
skreq->fitmsg_id);
dev_dbg(&skdev->pdev->dev, " timo=0x%x sg_dir=%d n_sg=%d\n",
skreq->timeout_stamp, skreq->data_dir, skreq->n_sg);
+
dev_dbg(&skdev->pdev->dev,
"req=%p lba=%u(0x%x) count=%u(0x%x) dir=%d\n", req, lba, lba,
count, count, (int)rq_data_dir(req));
--
2.16.4