[PATCH 03/17] ps3disk: convert to blk-mq

Jens Axboe
2018-10-11T16:58:55Z

Convert from the old request_fn style driver to blk-mq.

Cc: Geoff Levand <geoff@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
drivers/block/ps3disk.c | 95 +++++++++++++++++++++++------------------
1 file changed, 54 insertions(+), 41 deletions(-)

diff --git a/drivers/block/ps3disk.c b/drivers/block/ps3disk.c
index afe1508d82c6..e8b41e95a679 100644
--- a/drivers/block/ps3disk.c
+++ b/drivers/block/ps3disk.c
@@ -19,7 +19,7 @@
*/

#include <linux/ata.h>
-#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
#include <linux/slab.h>
#include <linux/module.h>

@@ -42,6 +42,7 @@
struct ps3disk_private {
spinlock_t lock; /* Request queue spinlock */
struct request_queue *queue;
+ struct blk_mq_tag_set tag_set;
struct gendisk *gendisk;
unsigned int blocking_factor;
struct request *req;
@@ -118,8 +119,8 @@ static void ps3disk_scatter_gather(struct ps3_storage_device *dev,
}
}

-static int ps3disk_submit_request_sg(struct ps3_storage_device *dev,
- struct request *req)
+static void ps3disk_submit_request_sg(struct ps3_storage_device *dev,
+ struct request *req)
{
struct ps3disk_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
int write = rq_data_dir(req), res;
@@ -158,16 +159,15 @@ static int ps3disk_submit_request_sg(struct ps3_storage_device *dev,
if (res) {
dev_err(&dev->sbd.core, "%s:%u: %s failed %d\n", __func__,
__LINE__, op, res);
- __blk_end_request_all(req, BLK_STS_IOERR);
- return 0;
+ blk_mq_end_request(req, BLK_STS_IOERR);
+ return;
}

priv->req = req;
- return 1;
}

-static int ps3disk_submit_flush_request(struct ps3_storage_device *dev,
- struct request *req)
+static void ps3disk_submit_flush_request(struct ps3_storage_device *dev,
+ struct request *req)
{
struct ps3disk_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
u64 res;
@@ -180,50 +180,46 @@ static int ps3disk_submit_flush_request(struct ps3_storage_device *dev,
if (res) {
dev_err(&dev->sbd.core, "%s:%u: sync cache failed 0x%llx\n",
__func__, __LINE__, res);
- __blk_end_request_all(req, BLK_STS_IOERR);
- return 0;
+ blk_mq_end_request(req, BLK_STS_IOERR);
+ return;
}

priv->req = req;
- return 1;
}

static void ps3disk_do_request(struct ps3_storage_device *dev,
- struct request_queue *q)
+ struct request *req)
{
- struct request *req;
-
dev_dbg(&dev->sbd.core, "%s:%u\n", __func__, __LINE__);

- while ((req = blk_fetch_request(q))) {
- switch (req_op(req)) {
- case REQ_OP_FLUSH:
- if (ps3disk_submit_flush_request(dev, req))
- return;
- break;
- case REQ_OP_READ:
- case REQ_OP_WRITE:
- if (ps3disk_submit_request_sg(dev, req))
- return;
- break;
- default:
- blk_dump_rq_flags(req, DEVICE_NAME " bad request");
- __blk_end_request_all(req, BLK_STS_IOERR);
- }
+ switch (req_op(req)) {
+ case REQ_OP_FLUSH:
+ ps3disk_submit_flush_request(dev, req);
+ break;
+ case REQ_OP_READ:
+ case REQ_OP_WRITE:
+ ps3disk_submit_request_sg(dev, req);
+ break;
+ default:
+ blk_dump_rq_flags(req, DEVICE_NAME " bad request");
+ blk_mq_end_request(req, BLK_STS_IOERR);
}
}

-static void ps3disk_request(struct request_queue *q)
+static blk_status_t ps3disk_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *bd)
{
+ struct request_queue *q = hctx->queue;
struct ps3_storage_device *dev = q->queuedata;
struct ps3disk_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);

- if (priv->req) {
- dev_dbg(&dev->sbd.core, "%s:%u busy\n", __func__, __LINE__);
- return;
- }
+ blk_mq_start_request(bd->rq);
+
+ spin_lock_irq(&priv->lock);
+ ps3disk_do_request(dev, bd->rq);
+ spin_unlock_irq(&priv->lock);

- ps3disk_do_request(dev, q);
+ return BLK_STS_OK;
}

static irqreturn_t ps3disk_interrupt(int irq, void *data)
@@ -279,12 +275,13 @@ static irqreturn_t ps3disk_interrupt(int irq, void *data)
ps3disk_scatter_gather(dev, req, 0);
}

+ blk_mq_end_request(req, error);
+
spin_lock(&priv->lock);
- __blk_end_request_all(req, error);
priv->req = NULL;
- ps3disk_do_request(dev, priv->queue);
spin_unlock(&priv->lock);

+ blk_mq_start_hw_queues(priv->queue);
return IRQ_HANDLED;
}

@@ -404,6 +401,10 @@ static unsigned long ps3disk_mask;

static DEFINE_MUTEX(ps3disk_mask_mutex);

+static const struct blk_mq_ops ps3disk_mq_ops = {
+ .queue_rq = ps3disk_queue_rq,
+};
+
static int ps3disk_probe(struct ps3_system_bus_device *_dev)
{
struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);
@@ -411,6 +412,7 @@ static int ps3disk_probe(struct ps3_system_bus_device *_dev)
int error;
unsigned int devidx;
struct request_queue *queue;
+ struct blk_mq_tag_set *set;
struct gendisk *gendisk;

if (dev->blk_size < 512) {
@@ -454,11 +456,21 @@ static int ps3disk_probe(struct ps3_system_bus_device *_dev)

ps3disk_identify(dev);

- queue = blk_init_queue(ps3disk_request, &priv->lock);
- if (!queue) {
- dev_err(&dev->sbd.core, "%s:%u: blk_init_queue failed\n",
+ set = &priv->tag_set;
+ set->ops = &ps3disk_mq_ops;
+ set->nr_hw_queues = 1;
+ set->queue_depth = 2;
+ set->numa_node = NUMA_NO_NODE;
+ set->flags = BLK_MQ_F_SHOULD_MERGE;
+ error = blk_mq_alloc_tag_set(set);
+ if (error)
+ goto fail_teardown;
+
+ queue = blk_mq_init_queue(set);
+ if (IS_ERR(queue)) {
+ dev_err(&dev->sbd.core, "%s:%u: blk_mq_init_queue failed\n",
__func__, __LINE__);
- error = -ENOMEM;
+ error = PTR_ERR(queue);
goto fail_teardown;
}

@@ -504,6 +516,7 @@ static int ps3disk_probe(struct ps3_system_bus_device *_dev)
return 0;

fail_cleanup_queue:
+ blk_mq_free_tag_set(&priv->tag_set);
blk_cleanup_queue(queue);
fail_teardown:
ps3stor_teardown(dev);
--
2.17.1