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s390/scm: use multiple queues

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Exploit multiple hardware contexts (queues) that can process
requests in parallel.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Sebastian Ott 2017-02-24 17:50:17 +01:00 committed by Martin Schwidefsky
parent c7b3e92331
commit 9861dbd5b4
2 changed files with 42 additions and 13 deletions
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52
drivers/s390/block/scm_blk.c
View File

@ -273,30 +273,36 @@ static void scm_request_start(struct scm_request *scmrq)
}
}
struct scm_queue {
struct scm_request *scmrq;
spinlock_t lock;
};
static int scm_blk_request(struct blk_mq_hw_ctx *hctx,
const struct blk_mq_queue_data *qd)
{
struct scm_device *scmdev = hctx->queue->queuedata;
struct scm_blk_dev *bdev = dev_get_drvdata(&scmdev->dev);
struct scm_queue *sq = hctx->driver_data;
struct request *req = qd->rq;
struct scm_request *scmrq;
spin_lock(&bdev->rq_lock);
spin_lock(&sq->lock);
if (!scm_permit_request(bdev, req)) {
spin_unlock(&bdev->rq_lock);
spin_unlock(&sq->lock);
return BLK_MQ_RQ_QUEUE_BUSY;
}
scmrq = hctx->driver_data;
scmrq = sq->scmrq;
if (!scmrq) {
scmrq = scm_request_fetch();
if (!scmrq) {
SCM_LOG(5, "no request");
spin_unlock(&bdev->rq_lock);
spin_unlock(&sq->lock);
return BLK_MQ_RQ_QUEUE_BUSY;
}
scm_request_init(bdev, scmrq);
hctx->driver_data = scmrq;
sq->scmrq = scmrq;
}
scm_request_set(scmrq, req);
@ -307,20 +313,43 @@ static int scm_blk_request(struct blk_mq_hw_ctx *hctx,
if (scmrq->aob->request.msb_count)
scm_request_start(scmrq);
hctx->driver_data = NULL;
spin_unlock(&bdev->rq_lock);
sq->scmrq = NULL;
spin_unlock(&sq->lock);
return BLK_MQ_RQ_QUEUE_BUSY;
}
blk_mq_start_request(req);
if (qd->last || scmrq->aob->request.msb_count == nr_requests_per_io) {
scm_request_start(scmrq);
hctx->driver_data = NULL;
sq->scmrq = NULL;
}
spin_unlock(&bdev->rq_lock);
spin_unlock(&sq->lock);
return BLK_MQ_RQ_QUEUE_OK;
}
static int scm_blk_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
unsigned int idx)
{
struct scm_queue *qd = kzalloc(sizeof(*qd), GFP_KERNEL);
if (!qd)
return -ENOMEM;
spin_lock_init(&qd->lock);
hctx->driver_data = qd;
return 0;
}
static void scm_blk_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
{
struct scm_queue *qd = hctx->driver_data;
WARN_ON(qd->scmrq);
kfree(hctx->driver_data);
hctx->driver_data = NULL;
}
static void __scmrq_log_error(struct scm_request *scmrq)
{
struct aob *aob = scmrq->aob;
@ -396,6 +425,8 @@ static const struct block_device_operations scm_blk_devops = {
static const struct blk_mq_ops scm_mq_ops = {
.queue_rq = scm_blk_request,
.complete = scm_blk_request_done,
.init_hctx = scm_blk_init_hctx,
.exit_hctx = scm_blk_exit_hctx,
};
int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev)
@ -413,12 +444,11 @@ int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev)
bdev->scmdev = scmdev;
bdev->state = SCM_OPER;
spin_lock_init(&bdev->rq_lock);
spin_lock_init(&bdev->lock);
atomic_set(&bdev->queued_reqs, 0);
bdev->tag_set.ops = &scm_mq_ops;
bdev->tag_set.nr_hw_queues = 1;
bdev->tag_set.nr_hw_queues = nr_requests;
bdev->tag_set.queue_depth = nr_requests_per_io * nr_requests;
bdev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;

3
drivers/s390/block/scm_blk.h
View File

@ -19,8 +19,7 @@ struct scm_blk_dev {
struct gendisk *gendisk;
struct blk_mq_tag_set tag_set;
struct scm_device *scmdev;
spinlock_t rq_lock; /* guard the request queue */
spinlock_t lock; /* guard the rest of the blockdev */
spinlock_t lock;
atomic_t queued_reqs;
enum {SCM_OPER, SCM_WR_PROHIBIT} state;
struct list_head finished_requests;