s390/scm: convert to blk-mq

Convert scm_blk to use the blk-mq API. This is just a simple
conversion since we still use a single queue.

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 2017-01-25 16:18:53 +01:00 committed by Martin Schwidefsky
parent 94d26bfcf3
commit 12d9076265
2 changed files with 80 additions and 71 deletions

View File

@ -13,6 +13,7 @@
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/list.h>
@ -110,13 +111,13 @@ static struct scm_request *scm_request_fetch(void)
{
struct scm_request *scmrq = NULL;
spin_lock(&list_lock);
spin_lock_irq(&list_lock);
if (list_empty(&inactive_requests))
goto out;
scmrq = list_first_entry(&inactive_requests, struct scm_request, list);
list_del(&scmrq->list);
out:
spin_unlock(&list_lock);
spin_unlock_irq(&list_lock);
return scmrq;
}
@ -232,26 +233,17 @@ static inline void scm_request_init(struct scm_blk_dev *bdev,
scmrq->next_aidaw = (void *) &aob->msb[nr_requests_per_io];
}
static void scm_ensure_queue_restart(struct scm_blk_dev *bdev)
{
if (atomic_read(&bdev->queued_reqs)) {
/* Queue restart is triggered by the next interrupt. */
return;
}
blk_delay_queue(bdev->rq, SCM_QUEUE_DELAY);
}
static void scm_request_requeue(struct scm_request *scmrq)
{
struct scm_blk_dev *bdev = scmrq->bdev;
int i;
for (i = 0; i < nr_requests_per_io && scmrq->request[i]; i++)
blk_requeue_request(bdev->rq, scmrq->request[i]);
blk_mq_requeue_request(scmrq->request[i], false);
atomic_dec(&bdev->queued_reqs);
scm_request_done(scmrq);
scm_ensure_queue_restart(bdev);
blk_mq_kick_requeue_list(bdev->rq);
}
static void scm_request_finish(struct scm_request *scmrq)
@ -259,73 +251,74 @@ static void scm_request_finish(struct scm_request *scmrq)
struct scm_blk_dev *bdev = scmrq->bdev;
int i;
for (i = 0; i < nr_requests_per_io && scmrq->request[i]; i++)
blk_end_request_all(scmrq->request[i], scmrq->error);
for (i = 0; i < nr_requests_per_io && scmrq->request[i]; i++) {
if (scmrq->error)
blk_mq_end_request(scmrq->request[i], scmrq->error);
else
blk_mq_complete_request(scmrq->request[i]);
}
atomic_dec(&bdev->queued_reqs);
scm_request_done(scmrq);
}
static int scm_request_start(struct scm_request *scmrq)
static void scm_request_start(struct scm_request *scmrq)
{
struct scm_blk_dev *bdev = scmrq->bdev;
int ret;
atomic_inc(&bdev->queued_reqs);
if (!scmrq->aob->request.msb_count) {
scm_request_requeue(scmrq);
return -EINVAL;
}
ret = eadm_start_aob(scmrq->aob);
if (ret) {
if (eadm_start_aob(scmrq->aob)) {
SCM_LOG(5, "no subchannel");
scm_request_requeue(scmrq);
}
return ret;
}
static void scm_blk_request(struct request_queue *rq)
static int scm_blk_request(struct blk_mq_hw_ctx *hctx,
const struct blk_mq_queue_data *qd)
{
struct scm_device *scmdev = rq->queuedata;
struct scm_device *scmdev = hctx->queue->queuedata;
struct scm_blk_dev *bdev = dev_get_drvdata(&scmdev->dev);
struct scm_request *scmrq = NULL;
struct request *req;
struct request *req = qd->rq;
struct scm_request *scmrq;
while ((req = blk_peek_request(rq))) {
if (!scm_permit_request(bdev, req))
goto out;
if (!scmrq) {
scmrq = scm_request_fetch();
if (!scmrq) {
SCM_LOG(5, "no request");
goto out;
}
scm_request_init(bdev, scmrq);
}
scm_request_set(scmrq, req);
if (scm_request_prepare(scmrq)) {
SCM_LOG(5, "aidaw alloc failed");
scm_request_set(scmrq, NULL);
goto out;
}
blk_start_request(req);
if (scmrq->aob->request.msb_count < nr_requests_per_io)
continue;
if (scm_request_start(scmrq))
return;
scmrq = NULL;
spin_lock(&bdev->rq_lock);
if (!scm_permit_request(bdev, req)) {
spin_unlock(&bdev->rq_lock);
return BLK_MQ_RQ_QUEUE_BUSY;
}
out:
if (scmrq)
scmrq = hctx->driver_data;
if (!scmrq) {
scmrq = scm_request_fetch();
if (!scmrq) {
SCM_LOG(5, "no request");
spin_unlock(&bdev->rq_lock);
return BLK_MQ_RQ_QUEUE_BUSY;
}
scm_request_init(bdev, scmrq);
hctx->driver_data = scmrq;
}
scm_request_set(scmrq, req);
if (scm_request_prepare(scmrq)) {
SCM_LOG(5, "aidaw alloc failed");
scm_request_set(scmrq, NULL);
if (scmrq->aob->request.msb_count)
scm_request_start(scmrq);
hctx->driver_data = NULL;
spin_unlock(&bdev->rq_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);
else
scm_ensure_queue_restart(bdev);
hctx->driver_data = NULL;
}
spin_unlock(&bdev->rq_lock);
return BLK_MQ_RQ_QUEUE_OK;
}
static void __scmrq_log_error(struct scm_request *scmrq)
@ -387,9 +380,7 @@ restart:
return;
requeue:
spin_lock_irqsave(&bdev->rq_lock, flags);
scm_request_requeue(scmrq);
spin_unlock_irqrestore(&bdev->rq_lock, flags);
}
static void scm_blk_tasklet(struct scm_blk_dev *bdev)
@ -416,19 +407,21 @@ static void scm_blk_tasklet(struct scm_blk_dev *bdev)
spin_lock_irqsave(&bdev->lock, flags);
}
spin_unlock_irqrestore(&bdev->lock, flags);
/* Look out for more requests. */
blk_run_queue(bdev->rq);
}
static const struct block_device_operations scm_blk_devops = {
.owner = THIS_MODULE,
};
static const struct blk_mq_ops scm_mq_ops = {
.queue_rq = scm_blk_request,
};
int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev)
{
struct request_queue *rq;
int len, ret = -ENOMEM;
unsigned int devindex, nr_max_blk;
struct request_queue *rq;
int len, ret;
devindex = atomic_inc_return(&nr_devices) - 1;
/* scma..scmz + scmaa..scmzz */
@ -447,10 +440,20 @@ int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev)
(void (*)(unsigned long)) scm_blk_tasklet,
(unsigned long) bdev);
rq = blk_init_queue(scm_blk_request, &bdev->rq_lock);
if (!rq)
bdev->tag_set.ops = &scm_mq_ops;
bdev->tag_set.nr_hw_queues = 1;
bdev->tag_set.queue_depth = nr_requests_per_io * nr_requests;
bdev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
ret = blk_mq_alloc_tag_set(&bdev->tag_set);
if (ret)
goto out;
rq = blk_mq_init_queue(&bdev->tag_set);
if (IS_ERR(rq)) {
ret = PTR_ERR(rq);
goto out_tag;
}
bdev->rq = rq;
nr_max_blk = min(scmdev->nr_max_block,
(unsigned int) (PAGE_SIZE / sizeof(struct aidaw)));
@ -462,9 +465,10 @@ int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev)
queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, rq);
bdev->gendisk = alloc_disk(SCM_NR_PARTS);
if (!bdev->gendisk)
if (!bdev->gendisk) {
ret = -ENOMEM;
goto out_queue;
}
rq->queuedata = scmdev;
bdev->gendisk->private_data = scmdev;
bdev->gendisk->fops = &scm_blk_devops;
@ -489,6 +493,8 @@ int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev)
out_queue:
blk_cleanup_queue(rq);
out_tag:
blk_mq_free_tag_set(&bdev->tag_set);
out:
atomic_dec(&nr_devices);
return ret;
@ -499,6 +505,7 @@ void scm_blk_dev_cleanup(struct scm_blk_dev *bdev)
tasklet_kill(&bdev->tasklet);
del_gendisk(bdev->gendisk);
blk_cleanup_queue(bdev->gendisk->queue);
blk_mq_free_tag_set(&bdev->tag_set);
put_disk(bdev->gendisk);
}

View File

@ -4,6 +4,7 @@
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include <linux/genhd.h>
#include <linux/list.h>
@ -17,6 +18,7 @@ struct scm_blk_dev {
struct tasklet_struct tasklet;
struct request_queue *rq;
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 */