[PATCH 00/13] Convert floppy drivers to blk-mq

[PATCH 00/13] Convert floppy drivers to blk-mq

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

Hi,

This series converts the various floppy drivers to blk-mq. Save for the
last one (floppy), they're compile-tested only. If I've Cc'd you, it's
because I think you might be able to test the changes. Please test if
you can, or let me know if there's a way to use QEMU/some other emulator
to test. The full series is available at [1]. Thanks!

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Laurent Vivier <lvivier@redhat.com>

1: https://github.com/osandov/linux/tree/mq-conversions.

Omar Sandoval (13):
  swim: fix cleanup on setup error
  swim: convert to blk-mq
  swim3: add real error handling in setup
  swim3: end whole request on error
  swim3: convert to blk-mq
  amiflop: fold headers into C file
  amiflop: clean up on errors during setup
  amiflop: convert to blk-mq
  ataflop: fold headers into C file
  ataflop: fix error handling during setup
  ataflop: convert to blk-mq
  floppy: end whole request on error
  floppy: convert to blk-mq

 arch/m68k/include/asm/atafd.h    |  13 --
 arch/m68k/include/asm/atafdreg.h |  80 --------
 drivers/block/amiflop.c          | 330 +++++++++++++++++++------------
 drivers/block/ataflop.c          | 288 ++++++++++++++++-----------
 drivers/block/floppy.c           |  80 +++++---
 drivers/block/swim.c             | 116 ++++++-----
 drivers/block/swim3.c            | 221 +++++++++++----------
 include/linux/amifd.h            |  63 ------
 include/linux/amifdreg.h         |  82 --------
 9 files changed, 604 insertions(+), 669 deletions(-)
 delete mode 100644 arch/m68k/include/asm/atafd.h
 delete mode 100644 arch/m68k/include/asm/atafdreg.h
 delete mode 100644 include/linux/amifd.h
 delete mode 100644 include/linux/amifdreg.h

-- 
2.19.1

[PATCH 01/13] swim: fix cleanup on setup error

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

If we fail to allocate the request queue for a disk, we still need to
free that disk, not just the previous ones. Additionally, we need to
cleanup the previous request queues.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 drivers/block/swim.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/block/swim.c b/drivers/block/swim.c
index 0e31884a9519..cbe909c51847 100644
--- a/drivers/block/swim.c
+++ b/drivers/block/swim.c
@@ -887,8 +887,17 @@ static int swim_floppy_init(struct swim_priv *swd)
 
 exit_put_disks:
 	unregister_blkdev(FLOPPY_MAJOR, "fd");
-	while (drive--)
-		put_disk(swd->unit[drive].disk);
+	do {
+		struct gendisk *disk = swd->unit[drive].disk;
+
+		if (disk) {
+			if (disk->queue) {
+				blk_cleanup_queue(disk->queue);
+				disk->queue = NULL;
+			}
+			put_disk(disk);
+		}
+	} while (drive--);
 	return err;
 }
 
-- 
2.19.1

[PATCH 02/13] swim: convert to blk-mq

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

The only interesting thing here is that there may be two floppies (i.e.,
request queues) sharing the same controller, so we use the global struct
swim_priv->lock to check whether the controller is busy. Compile-tested
only.

Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 drivers/block/swim.c | 103 +++++++++++++++++++++----------------------
 1 file changed, 51 insertions(+), 52 deletions(-)

diff --git a/drivers/block/swim.c b/drivers/block/swim.c
index cbe909c51847..bb3ac4da5b8d 100644
--- a/drivers/block/swim.c
+++ b/drivers/block/swim.c
@@ -19,7 +19,7 @@
 #include <linux/module.h>
 #include <linux/fd.h>
 #include <linux/slab.h>
-#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
 #include <linux/mutex.h>
 #include <linux/hdreg.h>
 #include <linux/kernel.h>
@@ -190,6 +190,7 @@ struct floppy_state {
 	int		ref_count;
 
 	struct gendisk *disk;
+	struct blk_mq_tag_set tag_set;
 
 	/* parent controller */
 
@@ -211,7 +212,6 @@ enum head {
 struct swim_priv {
 	struct swim __iomem *base;
 	spinlock_t lock;
-	int fdc_queue;
 	int floppy_count;
 	struct floppy_state unit[FD_MAX_UNIT];
 };
@@ -525,58 +525,38 @@ static blk_status_t floppy_read_sectors(struct floppy_state *fs,
 	return 0;
 }
 
-static struct request *swim_next_request(struct swim_priv *swd)
+static blk_status_t swim_queue_rq(struct blk_mq_hw_ctx *hctx,
+				  const struct blk_mq_queue_data *bd)
 {
-	struct request_queue *q;
-	struct request *rq;
-	int old_pos = swd->fdc_queue;
+	struct floppy_state *fs = hctx->queue->queuedata;
+	struct swim_priv *swd = fs->swd;
+	struct request *req = bd->rq;
+	blk_status_t err;
 
-	do {
-		q = swd->unit[swd->fdc_queue].disk->queue;
-		if (++swd->fdc_queue == swd->floppy_count)
-			swd->fdc_queue = 0;
-		if (q) {
-			rq = blk_fetch_request(q);
-			if (rq)
-				return rq;
-		}
-	} while (swd->fdc_queue != old_pos);
+	if (!spin_trylock_irq(&swd->lock))
+		return BLK_STS_DEV_RESOURCE;
 
-	return NULL;
-}
+	blk_mq_start_request(req);
 
-static void do_fd_request(struct request_queue *q)
-{
-	struct swim_priv *swd = q->queuedata;
-	struct request *req;
-	struct floppy_state *fs;
+	if (!fs->disk_in || rq_data_dir(req) == WRITE) {
+		err = BLK_STS_IOERR;
+		goto out;
+	}
 
-	req = swim_next_request(swd);
-	while (req) {
-		blk_status_t err = BLK_STS_IOERR;
+	do {
+		err = floppy_read_sectors(fs, blk_rq_pos(req),
+					  blk_rq_cur_sectors(req),
+					  bio_data(req->bio));
+		if (err)
+			break;
+	} while (blk_update_request(req, err, blk_rq_cur_bytes(req)));
+	blk_mq_end_request(req, err);
 
-		fs = req->rq_disk->private_data;
-		if (blk_rq_pos(req) >= fs->total_secs)
-			goto done;
-		if (!fs->disk_in)
-			goto done;
-		if (rq_data_dir(req) == WRITE && fs->write_protected)
-			goto done;
+	err = BLK_STS_OK;
+out:
+	spin_unlock_irq(&swd->lock);
+	return err;
 
-		switch (rq_data_dir(req)) {
-		case WRITE:
-			/* NOT IMPLEMENTED */
-			break;
-		case READ:
-			err = floppy_read_sectors(fs, blk_rq_pos(req),
-						  blk_rq_cur_sectors(req),
-						  bio_data(req->bio));
-			break;
-		}
-	done:
-		if (!__blk_end_request_cur(req, err))
-			req = swim_next_request(swd);
-	}
 }
 
 static struct floppy_struct floppy_type[4] = {
@@ -823,6 +803,10 @@ static int swim_add_floppy(struct swim_priv *swd, enum drive_location location)
 	return 0;
 }
 
+static const struct blk_mq_ops swim_mq_ops = {
+	.queue_rq = swim_queue_rq,
+};
+
 static int swim_floppy_init(struct swim_priv *swd)
 {
 	int err;
@@ -852,20 +836,33 @@ static int swim_floppy_init(struct swim_priv *swd)
 	spin_lock_init(&swd->lock);
 
 	for (drive = 0; drive < swd->floppy_count; drive++) {
+		struct blk_mq_tag_set *set;
+
 		swd->unit[drive].disk = alloc_disk(1);
 		if (swd->unit[drive].disk == NULL) {
 			err = -ENOMEM;
 			goto exit_put_disks;
 		}
-		swd->unit[drive].disk->queue = blk_init_queue(do_fd_request,
-							      &swd->lock);
-		if (!swd->unit[drive].disk->queue) {
-			err = -ENOMEM;
+
+		set = &swd->unit[drive].tag_set;
+		set->ops = &swim_mq_ops;
+		set->nr_hw_queues = 1;
+		set->queue_depth = 2;
+		set->numa_node = NUMA_NO_NODE;
+		set->flags = BLK_MQ_F_SHOULD_MERGE;
+		err = blk_mq_alloc_tag_set(set);
+		if (err)
+			goto exit_put_disks;
+
+		swd->unit[drive].disk->queue = blk_mq_init_queue(set);
+		if (IS_ERR(swd->unit[drive].disk->queue)) {
+			err = PTR_ERR(swd->unit[drive].disk->queue);
+			swd->unit[drive].disk->queue = NULL;
 			goto exit_put_disks;
 		}
 		blk_queue_bounce_limit(swd->unit[drive].disk->queue,
 				BLK_BOUNCE_HIGH);
-		swd->unit[drive].disk->queue->queuedata = swd;
+		swd->unit[drive].disk->queue->queuedata = &swd->unit[drive];
 		swd->unit[drive].swd = swd;
 	}
 
@@ -895,6 +892,7 @@ static int swim_floppy_init(struct swim_priv *swd)
 				blk_cleanup_queue(disk->queue);
 				disk->queue = NULL;
 			}
+			blk_mq_free_tag_set(&swd->unit[drive].tag_set);
 			put_disk(disk);
 		}
 	} while (drive--);
@@ -970,6 +968,7 @@ static int swim_remove(struct platform_device *dev)
 	for (drive = 0; drive < swd->floppy_count; drive++) {
 		del_gendisk(swd->unit[drive].disk);
 		blk_cleanup_queue(swd->unit[drive].disk->queue);
+		blk_mq_free_tag_set(&swd->unit[drive].tag_set);
 		put_disk(swd->unit[drive].disk);
 	}
 
-- 
2.19.1

[PATCH 03/13] swim3: add real error handling in setup

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

The driver doesn't have support for removing a device that has already
been configured, but with more careful ordering we can avoid the need
for that and make sure that we don't leak generic resources.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 drivers/block/swim3.c | 60 ++++++++++++++++++++++++++-----------------
 1 file changed, 36 insertions(+), 24 deletions(-)

diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c
index 469541c1e51e..df7ebe016e2c 100644
--- a/drivers/block/swim3.c
+++ b/drivers/block/swim3.c
@@ -1202,47 +1202,59 @@ static int swim3_add_device(struct macio_dev *mdev, int index)
 static int swim3_attach(struct macio_dev *mdev,
 			const struct of_device_id *match)
 {
+	struct floppy_state *fs;
 	struct gendisk *disk;
-	int index, rc;
+	int rc;
 
-	index = floppy_count++;
-	if (index >= MAX_FLOPPIES)
+	if (floppy_count >= MAX_FLOPPIES)
 		return -ENXIO;
 
-	/* Add the drive */
-	rc = swim3_add_device(mdev, index);
-	if (rc)
-		return rc;
-	/* Now register that disk. Same comment about failure handling */
-	disk = disks[index] = alloc_disk(1);
-	if (disk == NULL)
-		return -ENOMEM;
+	if (floppy_count == 0) {
+		rc = register_blkdev(FLOPPY_MAJOR, "fd");
+		if (rc)
+			return rc;
+	}
+
+	fs = &floppy_states[floppy_count];
+
+	disk = alloc_disk(1);
+	if (disk == NULL) {
+		rc = -ENOMEM;
+		goto out_unregister;
+	}
 	disk->queue = blk_init_queue(do_fd_request, &swim3_lock);
 	if (disk->queue == NULL) {
-		put_disk(disk);
-		return -ENOMEM;
+		rc = -ENOMEM;
+		goto out_put_disk;
 	}
 	blk_queue_bounce_limit(disk->queue, BLK_BOUNCE_HIGH);
-	disk->queue->queuedata = &floppy_states[index];
+	disk->queue->queuedata = fs;
 
-	if (index == 0) {
-		/* If we failed, there isn't much we can do as the driver is still
-		 * too dumb to remove the device, just bail out
-		 */
-		if (register_blkdev(FLOPPY_MAJOR, "fd"))
-			return 0;
-	}
+	rc = swim3_add_device(mdev, floppy_count);
+	if (rc)
+		goto out_cleanup_queue;
 
 	disk->major = FLOPPY_MAJOR;
-	disk->first_minor = index;
+	disk->first_minor = floppy_count;
 	disk->fops = &floppy_fops;
-	disk->private_data = &floppy_states[index];
+	disk->private_data = fs;
 	disk->flags |= GENHD_FL_REMOVABLE;
-	sprintf(disk->disk_name, "fd%d", index);
+	sprintf(disk->disk_name, "fd%d", floppy_count);
 	set_capacity(disk, 2880);
 	add_disk(disk);
 
+	disks[floppy_count++] = disk;
 	return 0;
+
+out_cleanup_queue:
+	blk_cleanup_queue(disk->queue);
+	disk->queue = NULL;
+out_put_disk:
+	put_disk(disk);
+out_unregister:
+	if (floppy_count == 0)
+		unregister_blkdev(FLOPPY_MAJOR, "fd");
+	return rc;
 }
 
 static const struct of_device_id swim3_match[] =
-- 
2.19.1

[PATCH 04/13] swim3: end whole request on error

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

When swim3_end_request() gets passed an error, it seems that the intent
is to end the whole request, but we're only ending the current segment.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 drivers/block/swim3.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c
index df7ebe016e2c..24e121ee274b 100644
--- a/drivers/block/swim3.c
+++ b/drivers/block/swim3.c
@@ -266,7 +266,7 @@ static bool swim3_end_request(struct floppy_state *fs, blk_status_t err, unsigne
 		  err, nr_bytes, req);
 
 	if (err)
-		nr_bytes = blk_rq_cur_bytes(req);
+		nr_bytes = blk_rq_bytes(req);
 	rc = __blk_end_request(req, err, nr_bytes);
 	if (rc)
 		return true;
-- 
2.19.1

[PATCH 05/13] swim3: convert to blk-mq

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

Pretty simple conversion. To avoid extra churn, we keep the
swim3_end_request() wrapper. grab_drive() could probably be replaced by
some freeze/quiesce incantation, but I left it alone, and just used
freeze/quiesce for eject. Compile-tested only.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 drivers/block/swim3.c | 163 +++++++++++++++++++-----------------------
 1 file changed, 75 insertions(+), 88 deletions(-)

diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c
index 24e121ee274b..e2061a4d43f7 100644
--- a/drivers/block/swim3.c
+++ b/drivers/block/swim3.c
@@ -25,7 +25,7 @@
 #include <linux/delay.h>
 #include <linux/fd.h>
 #include <linux/ioctl.h>
-#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
 #include <linux/interrupt.h>
 #include <linux/mutex.h>
 #include <linux/module.h>
@@ -206,6 +206,7 @@ struct floppy_state {
 	char	dbdma_cmd_space[5 * sizeof(struct dbdma_cmd)];
 	int	index;
 	struct request *cur_req;
+	struct blk_mq_tag_set tag_set;
 };
 
 #define swim3_err(fmt, arg...)	dev_err(&fs->mdev->ofdev.dev, "[fd%d] " fmt, fs->index, arg)
@@ -260,16 +261,15 @@ static int floppy_revalidate(struct gendisk *disk);
 static bool swim3_end_request(struct floppy_state *fs, blk_status_t err, unsigned int nr_bytes)
 {
 	struct request *req = fs->cur_req;
-	int rc;
 
 	swim3_dbg("  end request, err=%d nr_bytes=%d, cur_req=%p\n",
 		  err, nr_bytes, req);
 
 	if (err)
 		nr_bytes = blk_rq_bytes(req);
-	rc = __blk_end_request(req, err, nr_bytes);
-	if (rc)
+	if (blk_update_request(req, err, nr_bytes))
 		return true;
+	__blk_mq_end_request(req, err);
 	fs->cur_req = NULL;
 	return false;
 }
@@ -309,86 +309,58 @@ static int swim3_readbit(struct floppy_state *fs, int bit)
 	return (stat & DATA) == 0;
 }
 
-static void start_request(struct floppy_state *fs)
+static blk_status_t swim3_queue_rq(struct blk_mq_hw_ctx *hctx,
+				   const struct blk_mq_queue_data *bd)
 {
-	struct request *req;
+	struct floppy_state *fs = hctx->queue->queuedata;
+	struct request *req = bd->rq;
 	unsigned long x;
 
-	swim3_dbg("start request, initial state=%d\n", fs->state);
-
-	if (fs->state == idle && fs->wanted) {
-		fs->state = available;
-		wake_up(&fs->wait);
-		return;
+	spin_lock_irq(&swim3_lock);
+	if (fs->cur_req || fs->state != idle) {
+		spin_unlock_irq(&swim3_lock);
+		return BLK_STS_DEV_RESOURCE;
 	}
-	while (fs->state == idle) {
-		swim3_dbg("start request, idle loop, cur_req=%p\n", fs->cur_req);
-		if (!fs->cur_req) {
-			fs->cur_req = blk_fetch_request(disks[fs->index]->queue);
-			swim3_dbg("  fetched request %p\n", fs->cur_req);
-			if (!fs->cur_req)
-				break;
-		}
-		req = fs->cur_req;
-
-		if (fs->mdev->media_bay &&
-		    check_media_bay(fs->mdev->media_bay) != MB_FD) {
-			swim3_dbg("%s", "  media bay absent, dropping req\n");
-			swim3_end_request(fs, BLK_STS_IOERR, 0);
-			continue;
-		}
-
-#if 0 /* This is really too verbose */
-		swim3_dbg("do_fd_req: dev=%s cmd=%d sec=%ld nr_sec=%u buf=%p\n",
-			  req->rq_disk->disk_name, req->cmd,
-			  (long)blk_rq_pos(req), blk_rq_sectors(req),
-			  bio_data(req->bio));
-		swim3_dbg("           current_nr_sectors=%u\n",
-			  blk_rq_cur_sectors(req));
-#endif
-
-		if (blk_rq_pos(req) >= fs->total_secs) {
-			swim3_dbg("  pos out of bounds (%ld, max is %ld)\n",
-				  (long)blk_rq_pos(req), (long)fs->total_secs);
-			swim3_end_request(fs, BLK_STS_IOERR, 0);
-			continue;
-		}
-		if (fs->ejected) {
-			swim3_dbg("%s", "  disk ejected\n");
+	blk_mq_start_request(req);
+	fs->cur_req = req;
+	if (fs->mdev->media_bay &&
+	    check_media_bay(fs->mdev->media_bay) != MB_FD) {
+		swim3_dbg("%s", "  media bay absent, dropping req\n");
+		swim3_end_request(fs, BLK_STS_IOERR, 0);
+		goto out;
+	}
+	if (fs->ejected) {
+		swim3_dbg("%s", "  disk ejected\n");
+		swim3_end_request(fs, BLK_STS_IOERR, 0);
+		goto out;
+	}
+	if (rq_data_dir(req) == WRITE) {
+		if (fs->write_prot < 0)
+			fs->write_prot = swim3_readbit(fs, WRITE_PROT);
+		if (fs->write_prot) {
+			swim3_dbg("%s", "  try to write, disk write protected\n");
 			swim3_end_request(fs, BLK_STS_IOERR, 0);
-			continue;
-		}
-
-		if (rq_data_dir(req) == WRITE) {
-			if (fs->write_prot < 0)
-				fs->write_prot = swim3_readbit(fs, WRITE_PROT);
-			if (fs->write_prot) {
-				swim3_dbg("%s", "  try to write, disk write protected\n");
-				swim3_end_request(fs, BLK_STS_IOERR, 0);
-				continue;
-			}
+			goto out;
 		}
-
-		/* Do not remove the cast. blk_rq_pos(req) is now a
-		 * sector_t and can be 64 bits, but it will never go
-		 * past 32 bits for this driver anyway, so we can
-		 * safely cast it down and not have to do a 64/32
-		 * division
-		 */
-		fs->req_cyl = ((long)blk_rq_pos(req)) / fs->secpercyl;
-		x = ((long)blk_rq_pos(req)) % fs->secpercyl;
-		fs->head = x / fs->secpertrack;
-		fs->req_sector = x % fs->secpertrack + 1;
-		fs->state = do_transfer;
-		fs->retries = 0;
-
-		act(fs);
 	}
-}
 
-static void do_fd_request(struct request_queue * q)
-{
-	start_request(q->queuedata);
+	/*
+	 * Do not remove the cast. blk_rq_pos(req) is now a sector_t and can be
+	 * 64 bits, but it will never go past 32 bits for this driver anyway, so
+	 * we can safely cast it down and not have to do a 64/32 division
+	 */
+	fs->req_cyl = ((long)blk_rq_pos(req)) / fs->secpercyl;
+	x = ((long)blk_rq_pos(req)) % fs->secpercyl;
+	fs->head = x / fs->secpertrack;
+	fs->req_sector = x % fs->secpertrack + 1;
+	fs->state = do_transfer;
+	fs->retries = 0;
+
+	act(fs);
+
+out:
+	spin_unlock_irq(&swim3_lock);
+	return BLK_STS_OK;
 }
 
 static void set_timeout(struct floppy_state *fs, int nticks,
@@ -585,7 +557,6 @@ static void scan_timeout(struct timer_list *t)
 	if (fs->retries > 5) {
 		swim3_end_request(fs, BLK_STS_IOERR, 0);
 		fs->state = idle;
-		start_request(fs);
 	} else {
 		fs->state = jogging;
 		act(fs);
@@ -609,7 +580,6 @@ static void seek_timeout(struct timer_list *t)
 	swim3_err("%s", "Seek timeout\n");
 	swim3_end_request(fs, BLK_STS_IOERR, 0);
 	fs->state = idle;
-	start_request(fs);
 	spin_unlock_irqrestore(&swim3_lock, flags);
 }
 
@@ -638,7 +608,6 @@ static void settle_timeout(struct timer_list *t)
 	swim3_err("%s", "Seek settle timeout\n");
 	swim3_end_request(fs, BLK_STS_IOERR, 0);
 	fs->state = idle;
-	start_request(fs);
  unlock:
 	spin_unlock_irqrestore(&swim3_lock, flags);
 }
@@ -667,7 +636,6 @@ static void xfer_timeout(struct timer_list *t)
 	       (long)blk_rq_pos(fs->cur_req));
 	swim3_end_request(fs, BLK_STS_IOERR, 0);
 	fs->state = idle;
-	start_request(fs);
 	spin_unlock_irqrestore(&swim3_lock, flags);
 }
 
@@ -704,7 +672,6 @@ static irqreturn_t swim3_interrupt(int irq, void *dev_id)
 				if (fs->retries > 5) {
 					swim3_end_request(fs, BLK_STS_IOERR, 0);
 					fs->state = idle;
-					start_request(fs);
 				} else {
 					fs->state = jogging;
 					act(fs);
@@ -796,7 +763,6 @@ static irqreturn_t swim3_interrupt(int irq, void *dev_id)
 					  fs->state, rq_data_dir(req), intr, err);
 				swim3_end_request(fs, BLK_STS_IOERR, 0);
 				fs->state = idle;
-				start_request(fs);
 				break;
 			}
 			fs->retries = 0;
@@ -813,8 +779,6 @@ static irqreturn_t swim3_interrupt(int irq, void *dev_id)
 			} else
 				fs->state = idle;
 		}
-		if (fs->state == idle)
-			start_request(fs);
 		break;
 	default:
 		swim3_err("Don't know what to do in state %d\n", fs->state);
@@ -862,14 +826,19 @@ static int grab_drive(struct floppy_state *fs, enum swim_state state,
 
 static void release_drive(struct floppy_state *fs)
 {
+	struct request_queue *q = disks[fs->index]->queue;
 	unsigned long flags;
 
 	swim3_dbg("%s", "-> release drive\n");
 
 	spin_lock_irqsave(&swim3_lock, flags);
 	fs->state = idle;
-	start_request(fs);
 	spin_unlock_irqrestore(&swim3_lock, flags);
+
+	blk_mq_freeze_queue(q);
+	blk_mq_quiesce_queue(q);
+	blk_mq_unquiesce_queue(q);
+	blk_mq_unfreeze_queue(q);
 }
 
 static int fd_eject(struct floppy_state *fs)
@@ -1089,6 +1058,10 @@ static const struct block_device_operations floppy_fops = {
 	.revalidate_disk= floppy_revalidate,
 };
 
+static const struct blk_mq_ops swim3_mq_ops = {
+	.queue_rq = swim3_queue_rq,
+};
+
 static void swim3_mb_event(struct macio_dev* mdev, int mb_state)
 {
 	struct floppy_state *fs = macio_get_drvdata(mdev);
@@ -1222,10 +1195,22 @@ static int swim3_attach(struct macio_dev *mdev,
 		rc = -ENOMEM;
 		goto out_unregister;
 	}
-	disk->queue = blk_init_queue(do_fd_request, &swim3_lock);
-	if (disk->queue == NULL) {
-		rc = -ENOMEM;
+
+	fs->tag_set.ops = &swim3_mq_ops;
+	fs->tag_set.nr_hw_queues = 1;
+	fs->tag_set.queue_depth = 2;
+	fs->tag_set.numa_node = NUMA_NO_NODE;
+	fs->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
+
+	rc = blk_mq_alloc_tag_set(&fs->tag_set);
+	if (rc)
 		goto out_put_disk;
+
+	disk->queue = blk_mq_init_queue(&fs->tag_set);
+	if (IS_ERR(disk->queue)) {
+		rc = PTR_ERR(disk->queue);
+		disk->queue = NULL;
+		goto out_free_tag_set;
 	}
 	blk_queue_bounce_limit(disk->queue, BLK_BOUNCE_HIGH);
 	disk->queue->queuedata = fs;
@@ -1249,6 +1234,8 @@ static int swim3_attach(struct macio_dev *mdev,
 out_cleanup_queue:
 	blk_cleanup_queue(disk->queue);
 	disk->queue = NULL;
+out_free_tag_set:
+	blk_mq_free_tag_set(&fs->tag_set);
 out_put_disk:
 	put_disk(disk);
 out_unregister:
-- 
2.19.1

[PATCH 06/13] amiflop: fold headers into C file

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

amifd.h and amifdreg.h are only used from amiflop.c, and they're pretty
small, so move the contents to amiflop.c and get rid of the .h files.
This is preparation for adding a struct blk_mq_tag_set to struct
amiga_floppy_struct.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 drivers/block/amiflop.c  | 123 ++++++++++++++++++++++++++++++++++++++-
 include/linux/amifd.h    |  63 --------------------
 include/linux/amifdreg.h |  82 --------------------------
 3 files changed, 120 insertions(+), 148 deletions(-)
 delete mode 100644 include/linux/amifd.h
 delete mode 100644 include/linux/amifdreg.h

diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c
index 3aaf6af3ec23..a7d6e6a9b12f 100644
--- a/drivers/block/amiflop.c
+++ b/drivers/block/amiflop.c
@@ -61,10 +61,8 @@
 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/mutex.h>
-#include <linux/amifdreg.h>
-#include <linux/amifd.h>
 #include <linux/fs.h>
-#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
 #include <linux/elevator.h>
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
@@ -86,6 +84,125 @@
  *  Defines
  */
 
+/*
+ * CIAAPRA bits (read only)
+ */
+
+#define DSKRDY      (0x1<<5)        /* disk ready when low */
+#define DSKTRACK0   (0x1<<4)        /* head at track zero when low */
+#define DSKPROT     (0x1<<3)        /* disk protected when low */
+#define DSKCHANGE   (0x1<<2)        /* low when disk removed */
+
+/*
+ * CIAAPRB bits (read/write)
+ */
+
+#define DSKMOTOR    (0x1<<7)        /* motor on when low */
+#define DSKSEL3     (0x1<<6)        /* select drive 3 when low */
+#define DSKSEL2     (0x1<<5)        /* select drive 2 when low */
+#define DSKSEL1     (0x1<<4)        /* select drive 1 when low */
+#define DSKSEL0     (0x1<<3)        /* select drive 0 when low */
+#define DSKSIDE     (0x1<<2)        /* side selection: 0 = upper, 1 = lower */
+#define DSKDIREC    (0x1<<1)        /* step direction: 0=in, 1=out (to trk 0) */
+#define DSKSTEP     (0x1)           /* pulse low to step head 1 track */
+
+/*
+ * DSKBYTR bits (read only)
+ */
+
+#define DSKBYT      (1<<15)         /* register contains valid byte when set */
+#define DMAON       (1<<14)         /* disk DMA enabled */
+#define DISKWRITE   (1<<13)         /* disk write bit in DSKLEN enabled */
+#define WORDEQUAL   (1<<12)         /* DSKSYNC register match when true */
+/* bits 7-0 are data */
+
+/*
+ * ADKCON/ADKCONR bits
+ */
+
+#ifndef SETCLR
+#define ADK_SETCLR      (1<<15)     /* control bit */
+#endif
+#define ADK_PRECOMP1    (1<<14)     /* precompensation selection */
+#define ADK_PRECOMP0    (1<<13)     /* 00=none, 01=140ns, 10=280ns, 11=500ns */
+#define ADK_MFMPREC     (1<<12)     /* 0=GCR precomp., 1=MFM precomp. */
+#define ADK_WORDSYNC    (1<<10)     /* enable DSKSYNC auto DMA */
+#define ADK_MSBSYNC     (1<<9)      /* when 1, enable sync on MSbit (for GCR) */
+#define ADK_FAST        (1<<8)      /* bit cell: 0=2us (GCR), 1=1us (MFM) */
+
+/*
+ * DSKLEN bits
+ */
+
+#define DSKLEN_DMAEN    (1<<15)
+#define DSKLEN_WRITE    (1<<14)
+
+/*
+ * INTENA/INTREQ bits
+ */
+
+#define DSKINDEX    (0x1<<4)        /* DSKINDEX bit */
+
+/*
+ * Misc
+ */
+
+#define MFM_SYNC    0x4489          /* standard MFM sync value */
+
+/* Values for FD_COMMAND */
+#define FD_RECALIBRATE		0x07	/* move to track 0 */
+#define FD_SEEK			0x0F	/* seek track */
+#define FD_READ			0xE6	/* read with MT, MFM, SKip deleted */
+#define FD_WRITE		0xC5	/* write with MT, MFM */
+#define FD_SENSEI		0x08	/* Sense Interrupt Status */
+#define FD_SPECIFY		0x03	/* specify HUT etc */
+#define FD_FORMAT		0x4D	/* format one track */
+#define FD_VERSION		0x10	/* get version code */
+#define FD_CONFIGURE		0x13	/* configure FIFO operation */
+#define FD_PERPENDICULAR	0x12	/* perpendicular r/w mode */
+
+#define FD_MAX_UNITS    4	/* Max. Number of drives */
+#define FLOPPY_MAX_SECTORS	22	/* Max. Number of sectors per track */
+
+struct fd_data_type {
+	char *name;		/* description of data type */
+	int sects;		/* sectors per track */
+	int (*read_fkt)(int);	/* read whole track */
+	void (*write_fkt)(int);	/* write whole track */
+};
+
+struct fd_drive_type {
+	unsigned long code;		/* code returned from drive */
+	char *name;			/* description of drive */
+	unsigned int tracks;	/* number of tracks */
+	unsigned int heads;		/* number of heads */
+	unsigned int read_size;	/* raw read size for one track */
+	unsigned int write_size;	/* raw write size for one track */
+	unsigned int sect_mult;	/* sectors and gap multiplier (HD = 2) */
+	unsigned int precomp1;	/* start track for precomp 1 */
+	unsigned int precomp2;	/* start track for precomp 2 */
+	unsigned int step_delay;	/* time (in ms) for delay after step */
+	unsigned int settle_time;	/* time to settle after dir change */
+	unsigned int side_time;	/* time needed to change sides */
+};
+
+struct amiga_floppy_struct {
+	struct fd_drive_type *type;	/* type of floppy for this unit */
+	struct fd_data_type *dtype;	/* type of floppy for this unit */
+	int track;			/* current track (-1 == unknown) */
+	unsigned char *trackbuf;	/* current track (kmaloc()'d */
+
+	int blocks;			/* total # blocks on disk */
+
+	int changed;			/* true when not known */
+	int disk;			/* disk in drive (-1 == unknown) */
+	int motor;			/* true when motor is at speed */
+	int busy;			/* true when drive is active */
+	int dirty;			/* true when trackbuf is not on disk */
+	int status;			/* current error code for unit */
+	struct gendisk *gendisk;
+};
+
 /*
  *  Error codes
  */
diff --git a/include/linux/amifd.h b/include/linux/amifd.h
deleted file mode 100644
index 202a77dbe46d..000000000000
--- a/include/linux/amifd.h
+++ /dev/null
@@ -1,63 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _AMIFD_H
-#define _AMIFD_H
-
-/* Definitions for the Amiga floppy driver */
-
-#include <linux/fd.h>
-
-#define FD_MAX_UNITS    4	/* Max. Number of drives */
-#define FLOPPY_MAX_SECTORS	22	/* Max. Number of sectors per track */
-
-#ifndef ASSEMBLER
-
-struct fd_data_type {
-    char *name;			/* description of data type */
-    int sects;			/* sectors per track */
-#ifdef __STDC__
-    int (*read_fkt)(int);
-    void (*write_fkt)(int);
-#else
-    int (*read_fkt)();		/* read whole track */
-    void (*write_fkt)();		/* write whole track */
-#endif
-};
-
-/*
-** Floppy type descriptions
-*/
-
-struct fd_drive_type {
-    unsigned long code;		/* code returned from drive */
-    char *name;			/* description of drive */
-    unsigned int tracks;	/* number of tracks */
-    unsigned int heads;		/* number of heads */
-    unsigned int read_size;	/* raw read size for one track */
-    unsigned int write_size;	/* raw write size for one track */
-    unsigned int sect_mult;	/* sectors and gap multiplier (HD = 2) */
-    unsigned int precomp1;	/* start track for precomp 1 */
-    unsigned int precomp2;	/* start track for precomp 2 */
-    unsigned int step_delay;	/* time (in ms) for delay after step */
-    unsigned int settle_time;	/* time to settle after dir change */
-    unsigned int side_time;	/* time needed to change sides */
-};
-
-struct amiga_floppy_struct {
-    struct fd_drive_type *type;	/* type of floppy for this unit */
-    struct fd_data_type *dtype;	/* type of floppy for this unit */
-    int track;			/* current track (-1 == unknown) */
-    unsigned char *trackbuf;    /* current track (kmaloc()'d */
-
-    int blocks;			/* total # blocks on disk */
-
-    int changed;		/* true when not known */
-    int disk;			/* disk in drive (-1 == unknown) */
-    int motor;			/* true when motor is at speed */
-    int busy;			/* true when drive is active */
-    int dirty;			/* true when trackbuf is not on disk */
-    int status;			/* current error code for unit */
-    struct gendisk *gendisk;
-};
-#endif
-
-#endif
diff --git a/include/linux/amifdreg.h b/include/linux/amifdreg.h
deleted file mode 100644
index 9b514d05ec70..000000000000
--- a/include/linux/amifdreg.h
+++ /dev/null
@@ -1,82 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LINUX_AMIFDREG_H
-#define _LINUX_AMIFDREG_H
-
-/*
-** CIAAPRA bits (read only)
-*/
-
-#define DSKRDY      (0x1<<5)        /* disk ready when low */
-#define DSKTRACK0   (0x1<<4)        /* head at track zero when low */
-#define DSKPROT     (0x1<<3)        /* disk protected when low */
-#define DSKCHANGE   (0x1<<2)        /* low when disk removed */
-
-/*
-** CIAAPRB bits (read/write)
-*/
-
-#define DSKMOTOR    (0x1<<7)        /* motor on when low */
-#define DSKSEL3     (0x1<<6)        /* select drive 3 when low */
-#define DSKSEL2     (0x1<<5)        /* select drive 2 when low */
-#define DSKSEL1     (0x1<<4)        /* select drive 1 when low */
-#define DSKSEL0     (0x1<<3)        /* select drive 0 when low */
-#define DSKSIDE     (0x1<<2)        /* side selection: 0 = upper, 1 = lower */
-#define DSKDIREC    (0x1<<1)        /* step direction: 0=in, 1=out (to trk 0) */
-#define DSKSTEP     (0x1)           /* pulse low to step head 1 track */
-
-/*
-** DSKBYTR bits (read only)
-*/
-
-#define DSKBYT      (1<<15)         /* register contains valid byte when set */
-#define DMAON       (1<<14)         /* disk DMA enabled */
-#define DISKWRITE   (1<<13)         /* disk write bit in DSKLEN enabled */
-#define WORDEQUAL   (1<<12)         /* DSKSYNC register match when true */
-/* bits 7-0 are data */
-
-/*
-** ADKCON/ADKCONR bits
-*/
-
-#ifndef SETCLR
-#define ADK_SETCLR      (1<<15)     /* control bit */
-#endif
-#define ADK_PRECOMP1    (1<<14)     /* precompensation selection */
-#define ADK_PRECOMP0    (1<<13)     /* 00=none, 01=140ns, 10=280ns, 11=500ns */
-#define ADK_MFMPREC     (1<<12)     /* 0=GCR precomp., 1=MFM precomp. */
-#define ADK_WORDSYNC    (1<<10)     /* enable DSKSYNC auto DMA */
-#define ADK_MSBSYNC     (1<<9)      /* when 1, enable sync on MSbit (for GCR) */
-#define ADK_FAST        (1<<8)      /* bit cell: 0=2us (GCR), 1=1us (MFM) */
- 
-/*
-** DSKLEN bits
-*/
-
-#define DSKLEN_DMAEN    (1<<15)
-#define DSKLEN_WRITE    (1<<14)
-
-/*
-** INTENA/INTREQ bits
-*/
-
-#define DSKINDEX    (0x1<<4)        /* DSKINDEX bit */
-
-/*
-** Misc
-*/
- 
-#define MFM_SYNC    0x4489          /* standard MFM sync value */
-
-/* Values for FD_COMMAND */
-#define FD_RECALIBRATE		0x07	/* move to track 0 */
-#define FD_SEEK			0x0F	/* seek track */
-#define FD_READ			0xE6	/* read with MT, MFM, SKip deleted */
-#define FD_WRITE		0xC5	/* write with MT, MFM */
-#define FD_SENSEI		0x08	/* Sense Interrupt Status */
-#define FD_SPECIFY		0x03	/* specify HUT etc */
-#define FD_FORMAT		0x4D	/* format one track */
-#define FD_VERSION		0x10	/* get version code */
-#define FD_CONFIGURE		0x13	/* configure FIFO operation */
-#define FD_PERPENDICULAR	0x12	/* perpendicular r/w mode */
-
-#endif /* _LINUX_AMIFDREG_H */
-- 
2.19.1

[PATCH 07/13] amiflop: clean up on errors during setup

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

The error handling in fd_probe_drives() doesn't clean up at all. Fix it
up in preparation for converting to blk-mq. While we're here, get rid of
the commented out amiga_floppy_remove().

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 drivers/block/amiflop.c | 84 ++++++++++++++++++++---------------------
 1 file changed, 40 insertions(+), 44 deletions(-)

diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c
index a7d6e6a9b12f..eef3b085e70a 100644
--- a/drivers/block/amiflop.c
+++ b/drivers/block/amiflop.c
@@ -1818,11 +1818,41 @@ static const struct block_device_operations floppy_fops = {
 	.check_events	= amiga_check_events,
 };
 
+static struct gendisk *fd_alloc_disk(int drive)
+{
+	struct gendisk *disk;
+
+	disk = alloc_disk(1);
+	if (!disk)
+		goto out;
+
+	disk->queue = blk_init_queue(do_fd_request, &amiflop_lock);
+	if (IS_ERR(disk->queue)) {
+		disk->queue = NULL;
+		goto out_put_disk;
+	}
+
+	unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL);
+	if (!unit[drive].trackbuf)
+		goto out_cleanup_queue;
+
+	return disk;
+
+out_cleanup_queue:
+	blk_cleanup_queue(disk->queue);
+	disk->queue = NULL;
+out_put_disk:
+	put_disk(disk);
+out:
+	unit[drive].type->code = FD_NODRIVE;
+	return NULL;
+}
+
 static int __init fd_probe_drives(void)
 {
 	int drive,drives,nomem;
 
-	printk(KERN_INFO "FD: probing units\nfound ");
+	pr_info("FD: probing units\nfound");
 	drives=0;
 	nomem=0;
 	for(drive=0;drive<FD_MAX_UNITS;drive++) {
@@ -1830,27 +1860,17 @@ static int __init fd_probe_drives(void)
 		fd_probe(drive);
 		if (unit[drive].type->code == FD_NODRIVE)
 			continue;
-		disk = alloc_disk(1);
+
+		disk = fd_alloc_disk(drive);
 		if (!disk) {
-			unit[drive].type->code = FD_NODRIVE;
+			pr_cont(" no mem for fd%d", drive);
+			nomem = 1;
 			continue;
 		}
 		unit[drive].gendisk = disk;
-
-		disk->queue = blk_init_queue(do_fd_request, &amiflop_lock);
-		if (!disk->queue) {
-			unit[drive].type->code = FD_NODRIVE;
-			continue;
-		}
-
 		drives++;
-		if ((unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL)) == NULL) {
-			printk("no mem for ");
-			unit[drive].type = &drive_types[num_dr_types - 1]; /* FD_NODRIVE */
-			drives--;
-			nomem = 1;
-		}
-		printk("fd%d ",drive);
+
+		pr_cont(" fd%d",drive);
 		disk->major = FLOPPY_MAJOR;
 		disk->first_minor = drive;
 		disk->fops = &floppy_fops;
@@ -1861,11 +1881,11 @@ static int __init fd_probe_drives(void)
 	}
 	if ((drives > 0) || (nomem == 0)) {
 		if (drives == 0)
-			printk("no drives");
-		printk("\n");
+			pr_cont(" no drives");
+		pr_cont("\n");
 		return drives;
 	}
-	printk("\n");
+	pr_cont("\n");
 	return -ENOMEM;
 }
  
@@ -1948,30 +1968,6 @@ static int __init amiga_floppy_probe(struct platform_device *pdev)
 	return ret;
 }
 
-#if 0 /* not safe to unload */
-static int __exit amiga_floppy_remove(struct platform_device *pdev)
-{
-	int i;
-
-	for( i = 0; i < FD_MAX_UNITS; i++) {
-		if (unit[i].type->code != FD_NODRIVE) {
-			struct request_queue *q = unit[i].gendisk->queue;
-			del_gendisk(unit[i].gendisk);
-			put_disk(unit[i].gendisk);
-			kfree(unit[i].trackbuf);
-			if (q)
-				blk_cleanup_queue(q);
-		}
-	}
-	blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
-	free_irq(IRQ_AMIGA_CIAA_TB, NULL);
-	free_irq(IRQ_AMIGA_DSKBLK, NULL);
-	custom.dmacon = DMAF_DISK; /* disable DMA */
-	amiga_chip_free(raw_buf);
-	unregister_blkdev(FLOPPY_MAJOR, "fd");
-}
-#endif
-
 static struct platform_driver amiga_floppy_driver = {
 	.driver   = {
 		.name	= "amiga-floppy",
-- 
2.19.1

[PATCH 08/13] amiflop: convert to blk-mq

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

Straightforward conversion, just use the existing amiflop_lock to
serialize access to the controller. Compile-tested only.

Cc: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 drivers/block/amiflop.c | 127 +++++++++++++++-------------------------
 1 file changed, 48 insertions(+), 79 deletions(-)

diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c
index eef3b085e70a..e9c701f9b32b 100644
--- a/drivers/block/amiflop.c
+++ b/drivers/block/amiflop.c
@@ -201,6 +201,7 @@ struct amiga_floppy_struct {
 	int dirty;			/* true when trackbuf is not on disk */
 	int status;			/* current error code for unit */
 	struct gendisk *gendisk;
+	struct blk_mq_tag_set tag_set;
 };
 
 /*
@@ -281,7 +282,6 @@ static volatile int selected = -1;	/* currently selected drive */
 static int writepending;
 static int writefromint;
 static char *raw_buf;
-static int fdc_queue;
 
 static DEFINE_SPINLOCK(amiflop_lock);
 
@@ -1454,76 +1454,20 @@ static int get_track(int drive, int track)
 	return -1;
 }
 
-/*
- * Round-robin between our available drives, doing one request from each
- */
-static struct request *set_next_request(void)
+static blk_status_t amiflop_rw_cur_segment(struct amiga_floppy_struct *floppy,
+					   struct request *rq)
 {
-	struct request_queue *q;
-	int cnt = FD_MAX_UNITS;
-	struct request *rq = NULL;
-
-	/* Find next queue we can dispatch from */
-	fdc_queue = fdc_queue + 1;
-	if (fdc_queue == FD_MAX_UNITS)
-		fdc_queue = 0;
-
-	for(cnt = FD_MAX_UNITS; cnt > 0; cnt--) {
-
-		if (unit[fdc_queue].type->code == FD_NODRIVE) {
-			if (++fdc_queue == FD_MAX_UNITS)
-				fdc_queue = 0;
-			continue;
-		}
-
-		q = unit[fdc_queue].gendisk->queue;
-		if (q) {
-			rq = blk_fetch_request(q);
-			if (rq)
-				break;
-		}
-
-		if (++fdc_queue == FD_MAX_UNITS)
-			fdc_queue = 0;
-	}
-
-	return rq;
-}
-
-static void redo_fd_request(void)
-{
-	struct request *rq;
+	int drive = floppy - unit;
 	unsigned int cnt, block, track, sector;
-	int drive;
-	struct amiga_floppy_struct *floppy;
 	char *data;
-	unsigned long flags;
-	blk_status_t err;
-
-next_req:
-	rq = set_next_request();
-	if (!rq) {
-		/* Nothing left to do */
-		return;
-	}
 
-	floppy = rq->rq_disk->private_data;
-	drive = floppy - unit;
-
-next_segment:
-	/* Here someone could investigate to be more efficient */
-	for (cnt = 0, err = BLK_STS_OK; cnt < blk_rq_cur_sectors(rq); cnt++) {
+	for (cnt = 0; cnt < blk_rq_cur_sectors(rq); cnt++) {
 #ifdef DEBUG
 		printk("fd: sector %ld + %d requested for %s\n",
 		       blk_rq_pos(rq), cnt,
 		       (rq_data_dir(rq) == READ) ? "read" : "write");
 #endif
 		block = blk_rq_pos(rq) + cnt;
-		if ((int)block > floppy->blocks) {
-			err = BLK_STS_IOERR;
-			break;
-		}
-
 		track = block / (floppy->dtype->sects * floppy->type->sect_mult);
 		sector = block % (floppy->dtype->sects * floppy->type->sect_mult);
 		data = bio_data(rq->bio) + 512 * cnt;
@@ -1532,10 +1476,8 @@ static void redo_fd_request(void)
 		       "0x%08lx\n", track, sector, data);
 #endif
 
-		if (get_track(drive, track) == -1) {
-			err = BLK_STS_IOERR;
-			break;
-		}
+		if (get_track(drive, track) == -1)
+			return BLK_STS_IOERR;
 
 		if (rq_data_dir(rq) == READ) {
 			memcpy(data, floppy->trackbuf + sector * 512, 512);
@@ -1543,31 +1485,42 @@ static void redo_fd_request(void)
 			memcpy(floppy->trackbuf + sector * 512, data, 512);
 
 			/* keep the drive spinning while writes are scheduled */
-			if (!fd_motor_on(drive)) {
-				err = BLK_STS_IOERR;
-				break;
-			}
+			if (!fd_motor_on(drive))
+				return BLK_STS_IOERR;
 			/*
 			 * setup a callback to write the track buffer
 			 * after a short (1 tick) delay.
 			 */
-			local_irq_save(flags);
-
 			floppy->dirty = 1;
 		        /* reset the timer */
 			mod_timer (flush_track_timer + drive, jiffies + 1);
-			local_irq_restore(flags);
 		}
 	}
 
-	if (__blk_end_request_cur(rq, err))
-		goto next_segment;
-	goto next_req;
+	return BLK_STS_OK;
 }
 
-static void do_fd_request(struct request_queue * q)
+static blk_status_t amiflop_queue_rq(struct blk_mq_hw_ctx *hctx,
+				     const struct blk_mq_queue_data *bd)
 {
-	redo_fd_request();
+	struct request *rq = bd->rq;
+	struct amiga_floppy_struct *floppy = rq->rq_disk->private_data;
+	blk_status_t err;
+
+	if (!spin_trylock_irq(&amiflop_lock))
+		return BLK_STS_DEV_RESOURCE;
+
+	blk_mq_start_request(rq);
+
+	do {
+		err = amiflop_rw_cur_segment(floppy, rq);
+		if (err)
+			break;
+	} while (blk_update_request(rq, err, blk_rq_cur_bytes(rq)));
+	blk_mq_end_request(rq, err);
+
+	spin_unlock_irq(&amiflop_lock);
+	return BLK_STS_OK;
 }
 
 static int fd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
@@ -1818,18 +1771,32 @@ static const struct block_device_operations floppy_fops = {
 	.check_events	= amiga_check_events,
 };
 
+static const struct blk_mq_ops amiflop_mq_ops = {
+	.queue_rq = amiflop_queue_rq,
+};
+
 static struct gendisk *fd_alloc_disk(int drive)
 {
 	struct gendisk *disk;
+	struct blk_mq_tag_set *set;
 
 	disk = alloc_disk(1);
 	if (!disk)
 		goto out;
 
-	disk->queue = blk_init_queue(do_fd_request, &amiflop_lock);
+	set = &unit[drive].tag_set;
+	set->ops = &amiflop_mq_ops;
+	set->nr_hw_queues = 1;
+	set->queue_depth = 2;
+	set->numa_node = NUMA_NO_NODE;
+	set->flags = BLK_MQ_F_SHOULD_MERGE;
+	if (blk_mq_alloc_tag_set(set))
+		goto out_put_disk;
+
+	disk->queue = blk_mq_init_queue(set);
 	if (IS_ERR(disk->queue)) {
 		disk->queue = NULL;
-		goto out_put_disk;
+		goto out_free_tag_set;
 	}
 
 	unit[drive].trackbuf = kmalloc(FLOPPY_MAX_SECTORS * 512, GFP_KERNEL);
@@ -1841,6 +1808,8 @@ static struct gendisk *fd_alloc_disk(int drive)
 out_cleanup_queue:
 	blk_cleanup_queue(disk->queue);
 	disk->queue = NULL;
+out_free_tag_set:
+	blk_mq_free_tag_set(set);
 out_put_disk:
 	put_disk(disk);
 out:
-- 
2.19.1

[PATCH 09/13] ataflop: fold headers into C file

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

atafd.h and atafdreg.h are only used from ataflop.c, so merge them in
there.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 arch/m68k/include/asm/atafd.h    | 13 -----
 arch/m68k/include/asm/atafdreg.h | 80 ------------------------------
 drivers/block/ataflop.c          | 83 +++++++++++++++++++++++++++++++-
 3 files changed, 81 insertions(+), 95 deletions(-)
 delete mode 100644 arch/m68k/include/asm/atafd.h
 delete mode 100644 arch/m68k/include/asm/atafdreg.h

diff --git a/arch/m68k/include/asm/atafd.h b/arch/m68k/include/asm/atafd.h
deleted file mode 100644
index ad7014cad633..000000000000
--- a/arch/m68k/include/asm/atafd.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_M68K_FD_H
-#define _ASM_M68K_FD_H
-
-/* Definitions for the Atari Floppy driver */
-
-struct atari_format_descr {
-    int track;			/* to be formatted */
-    int head;			/*   ""     ""     */
-    int sect_offset;		/* offset of first sector */
-};
-
-#endif
diff --git a/arch/m68k/include/asm/atafdreg.h b/arch/m68k/include/asm/atafdreg.h
deleted file mode 100644
index c31b4919ed2d..000000000000
--- a/arch/m68k/include/asm/atafdreg.h
+++ /dev/null
@@ -1,80 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LINUX_FDREG_H
-#define _LINUX_FDREG_H
-
-/*
-** WD1772 stuff
- */
-
-/* register codes */
-
-#define FDCSELREG_STP   (0x80)   /* command/status register */
-#define FDCSELREG_TRA   (0x82)   /* track register */
-#define FDCSELREG_SEC   (0x84)   /* sector register */
-#define FDCSELREG_DTA   (0x86)   /* data register */
-
-/* register names for FDC_READ/WRITE macros */
-
-#define FDCREG_CMD		0
-#define FDCREG_STATUS	0
-#define FDCREG_TRACK	2
-#define FDCREG_SECTOR	4
-#define FDCREG_DATA		6
-
-/* command opcodes */
-
-#define FDCCMD_RESTORE  (0x00)   /*  -                   */
-#define FDCCMD_SEEK     (0x10)   /*   |                  */
-#define FDCCMD_STEP     (0x20)   /*   |  TYP 1 Commands  */
-#define FDCCMD_STIN     (0x40)   /*   |                  */
-#define FDCCMD_STOT     (0x60)   /*  -                   */
-#define FDCCMD_RDSEC    (0x80)   /*  -   TYP 2 Commands  */
-#define FDCCMD_WRSEC    (0xa0)   /*  -          "        */
-#define FDCCMD_RDADR    (0xc0)   /*  -                   */
-#define FDCCMD_RDTRA    (0xe0)   /*   |  TYP 3 Commands  */
-#define FDCCMD_WRTRA    (0xf0)   /*  -                   */
-#define FDCCMD_FORCI    (0xd0)   /*  -   TYP 4 Command   */
-
-/* command modifier bits */
-
-#define FDCCMDADD_SR6   (0x00)   /* step rate settings */
-#define FDCCMDADD_SR12  (0x01)
-#define FDCCMDADD_SR2   (0x02)
-#define FDCCMDADD_SR3   (0x03)
-#define FDCCMDADD_V     (0x04)   /* verify */
-#define FDCCMDADD_H     (0x08)   /* wait for spin-up */
-#define FDCCMDADD_U     (0x10)   /* update track register */
-#define FDCCMDADD_M     (0x10)   /* multiple sector access */
-#define FDCCMDADD_E     (0x04)   /* head settling flag */
-#define FDCCMDADD_P     (0x02)   /* precompensation off */
-#define FDCCMDADD_A0    (0x01)   /* DAM flag */
-
-/* status register bits */
-
-#define	FDCSTAT_MOTORON	(0x80)   /* motor on */
-#define	FDCSTAT_WPROT	(0x40)   /* write protected (FDCCMD_WR*) */
-#define	FDCSTAT_SPINUP	(0x20)   /* motor speed stable (Type I) */
-#define	FDCSTAT_DELDAM	(0x20)   /* sector has deleted DAM (Type II+III) */
-#define	FDCSTAT_RECNF	(0x10)   /* record not found */
-#define	FDCSTAT_CRC		(0x08)   /* CRC error */
-#define	FDCSTAT_TR00	(0x04)   /* Track 00 flag (Type I) */
-#define	FDCSTAT_LOST	(0x04)   /* Lost Data (Type II+III) */
-#define	FDCSTAT_IDX		(0x02)   /* Index status (Type I) */
-#define	FDCSTAT_DRQ		(0x02)   /* DRQ status (Type II+III) */
-#define	FDCSTAT_BUSY	(0x01)   /* FDC is busy */
-
-
-/* PSG Port A Bit Nr 0 .. Side Sel .. 0 -> Side 1  1 -> Side 2 */
-#define DSKSIDE     (0x01)
-
-#define DSKDRVNONE  (0x06)
-#define DSKDRV0     (0x02)
-#define DSKDRV1     (0x04)
-
-/* step rates */
-#define	FDCSTEP_6	0x00
-#define	FDCSTEP_12	0x01
-#define	FDCSTEP_2	0x02
-#define	FDCSTEP_3	0x03
-
-#endif
diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index dfb2c2622e5a..17df631c5d85 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -71,8 +71,6 @@
 #include <linux/completion.h>
 #include <linux/wait.h>
 
-#include <asm/atafd.h>
-#include <asm/atafdreg.h>
 #include <asm/atariints.h>
 #include <asm/atari_stdma.h>
 #include <asm/atari_stram.h>
@@ -85,6 +83,87 @@ static DEFINE_MUTEX(ataflop_mutex);
 static struct request *fd_request;
 static int fdc_queue;
 
+/*
+ * WD1772 stuff
+ */
+
+/* register codes */
+
+#define FDCSELREG_STP   (0x80)   /* command/status register */
+#define FDCSELREG_TRA   (0x82)   /* track register */
+#define FDCSELREG_SEC   (0x84)   /* sector register */
+#define FDCSELREG_DTA   (0x86)   /* data register */
+
+/* register names for FDC_READ/WRITE macros */
+
+#define FDCREG_CMD		0
+#define FDCREG_STATUS	0
+#define FDCREG_TRACK	2
+#define FDCREG_SECTOR	4
+#define FDCREG_DATA		6
+
+/* command opcodes */
+
+#define FDCCMD_RESTORE  (0x00)   /*  -                   */
+#define FDCCMD_SEEK     (0x10)   /*   |                  */
+#define FDCCMD_STEP     (0x20)   /*   |  TYP 1 Commands  */
+#define FDCCMD_STIN     (0x40)   /*   |                  */
+#define FDCCMD_STOT     (0x60)   /*  -                   */
+#define FDCCMD_RDSEC    (0x80)   /*  -   TYP 2 Commands  */
+#define FDCCMD_WRSEC    (0xa0)   /*  -          "        */
+#define FDCCMD_RDADR    (0xc0)   /*  -                   */
+#define FDCCMD_RDTRA    (0xe0)   /*   |  TYP 3 Commands  */
+#define FDCCMD_WRTRA    (0xf0)   /*  -                   */
+#define FDCCMD_FORCI    (0xd0)   /*  -   TYP 4 Command   */
+
+/* command modifier bits */
+
+#define FDCCMDADD_SR6   (0x00)   /* step rate settings */
+#define FDCCMDADD_SR12  (0x01)
+#define FDCCMDADD_SR2   (0x02)
+#define FDCCMDADD_SR3   (0x03)
+#define FDCCMDADD_V     (0x04)   /* verify */
+#define FDCCMDADD_H     (0x08)   /* wait for spin-up */
+#define FDCCMDADD_U     (0x10)   /* update track register */
+#define FDCCMDADD_M     (0x10)   /* multiple sector access */
+#define FDCCMDADD_E     (0x04)   /* head settling flag */
+#define FDCCMDADD_P     (0x02)   /* precompensation off */
+#define FDCCMDADD_A0    (0x01)   /* DAM flag */
+
+/* status register bits */
+
+#define	FDCSTAT_MOTORON	(0x80)   /* motor on */
+#define	FDCSTAT_WPROT	(0x40)   /* write protected (FDCCMD_WR*) */
+#define	FDCSTAT_SPINUP	(0x20)   /* motor speed stable (Type I) */
+#define	FDCSTAT_DELDAM	(0x20)   /* sector has deleted DAM (Type II+III) */
+#define	FDCSTAT_RECNF	(0x10)   /* record not found */
+#define	FDCSTAT_CRC		(0x08)   /* CRC error */
+#define	FDCSTAT_TR00	(0x04)   /* Track 00 flag (Type I) */
+#define	FDCSTAT_LOST	(0x04)   /* Lost Data (Type II+III) */
+#define	FDCSTAT_IDX		(0x02)   /* Index status (Type I) */
+#define	FDCSTAT_DRQ		(0x02)   /* DRQ status (Type II+III) */
+#define	FDCSTAT_BUSY	(0x01)   /* FDC is busy */
+
+
+/* PSG Port A Bit Nr 0 .. Side Sel .. 0 -> Side 1  1 -> Side 2 */
+#define DSKSIDE     (0x01)
+
+#define DSKDRVNONE  (0x06)
+#define DSKDRV0     (0x02)
+#define DSKDRV1     (0x04)
+
+/* step rates */
+#define	FDCSTEP_6	0x00
+#define	FDCSTEP_12	0x01
+#define	FDCSTEP_2	0x02
+#define	FDCSTEP_3	0x03
+
+struct atari_format_descr {
+	int track;		/* to be formatted */
+	int head;		/*   ""     ""     */
+	int sect_offset;	/* offset of first sector */
+};
+
 /* Disk types: DD, HD, ED */
 static struct atari_disk_type {
 	const char	*name;
-- 
2.19.1

[PATCH 10/13] ataflop: fix error handling during setup

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

Move queue allocation next to disk allocation to fix a couple of issues:

- If add_disk() hasn't been called, we should clear disk->queue before
  calling put_disk().
- If we fail to allocate a request queue, we still need to put all of
  the disks, not just the ones that we allocated queues for.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 drivers/block/ataflop.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index 17df631c5d85..0144d598ac47 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -2014,6 +2014,11 @@ static int __init atari_floppy_init (void)
 		unit[i].disk = alloc_disk(1);
 		if (!unit[i].disk)
 			goto Enomem;
+
+		unit[i].disk->queue = blk_init_queue(do_fd_request,
+						     &ataflop_lock);
+		if (!unit[i].disk->queue)
+			goto Enomem;
 	}
 
 	if (UseTrackbuffer < 0)
@@ -2045,10 +2050,6 @@ static int __init atari_floppy_init (void)
 		sprintf(unit[i].disk->disk_name, "fd%d", i);
 		unit[i].disk->fops = &floppy_fops;
 		unit[i].disk->private_data = &unit[i];
-		unit[i].disk->queue = blk_init_queue(do_fd_request,
-					&ataflop_lock);
-		if (!unit[i].disk->queue)
-			goto Enomem;
 		set_capacity(unit[i].disk, MAX_DISK_SIZE * 2);
 		add_disk(unit[i].disk);
 	}
@@ -2063,13 +2064,17 @@ static int __init atari_floppy_init (void)
 
 	return 0;
 Enomem:
-	while (i--) {
-		struct request_queue *q = unit[i].disk->queue;
+	do {
+		struct gendisk *disk = unit[i].disk;
 
-		put_disk(unit[i].disk);
-		if (q)
-			blk_cleanup_queue(q);
-	}
+		if (disk) {
+			if (disk->queue) {
+				blk_cleanup_queue(disk->queue);
+				disk->queue = NULL;
+			}
+			put_disk(unit[i].disk);
+		}
+	} while (i--);
 
 	unregister_blkdev(FLOPPY_MAJOR, "fd");
 	return -ENOMEM;
-- 
2.19.1

[PATCH 11/13] ataflop: convert to blk-mq

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

This driver is already pretty broken, in that it has two wait_events()
(one in stdma_lock()) in request_fn. Get rid of the first one by
freezing/quiescing the queue on format, and the second one by replacing
it with stdma_try_lock(). The rest is straightforward. Compile-tested
only and probably incorrect.

Cc: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 drivers/block/ataflop.c | 188 ++++++++++++++++++----------------------
 1 file changed, 86 insertions(+), 102 deletions(-)

diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index 0144d598ac47..5934e30d4805 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -66,7 +66,7 @@
 #include <linux/fd.h>
 #include <linux/delay.h>
 #include <linux/init.h>
-#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
 #include <linux/mutex.h>
 #include <linux/completion.h>
 #include <linux/wait.h>
@@ -81,7 +81,6 @@
 
 static DEFINE_MUTEX(ataflop_mutex);
 static struct request *fd_request;
-static int fdc_queue;
 
 /*
  * WD1772 stuff
@@ -300,6 +299,7 @@ static struct atari_floppy_struct {
 	struct gendisk *disk;
 	int ref;
 	int type;
+	struct blk_mq_tag_set tag_set;
 } unit[FD_MAX_UNITS];
 
 #define	UD	unit[drive]
@@ -379,9 +379,6 @@ static int IsFormatting = 0, FormatError;
 static int UserSteprate[FD_MAX_UNITS] = { -1, -1 };
 module_param_array(UserSteprate, int, NULL, 0);
 
-/* Synchronization of FDC access. */
-static volatile int fdc_busy = 0;
-static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
 static DECLARE_COMPLETION(format_wait);
 
 static unsigned long changed_floppies = 0xff, fake_change = 0;
@@ -441,7 +438,6 @@ static void fd_times_out(struct timer_list *unused);
 static void finish_fdc( void );
 static void finish_fdc_done( int dummy );
 static void setup_req_params( int drive );
-static void redo_fd_request( void);
 static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode, unsigned int
                      cmd, unsigned long param);
 static void fd_probe( int drive );
@@ -459,8 +455,16 @@ static DEFINE_TIMER(fd_timer, check_change);
 	
 static void fd_end_request_cur(blk_status_t err)
 {
-	if (!__blk_end_request_cur(fd_request, err))
+	if (err) {
+		blk_mq_end_request(fd_request, err);
+		return;
+	}
+
+	if (!blk_update_request(fd_request, err,
+				blk_rq_cur_bytes(fd_request))) {
+		__blk_mq_end_request(fd_request, err);
 		fd_request = NULL;
+	}
 }
 
 static inline void start_motor_off_timer(void)
@@ -706,7 +710,6 @@ static void fd_error( void )
 		if (SelectedDrive != -1)
 			SUD.track = -1;
 	}
-	redo_fd_request();
 }
 
 
@@ -724,14 +727,15 @@ static void fd_error( void )
 
 static int do_format(int drive, int type, struct atari_format_descr *desc)
 {
+	struct request_queue *q = unit[drive].disk->queue;
 	unsigned char	*p;
 	int sect, nsect;
 	unsigned long	flags;
+	int ret;
 
-	DPRINT(("do_format( dr=%d tr=%d he=%d offs=%d )\n",
-		drive, desc->track, desc->head, desc->sect_offset ));
+	blk_mq_freeze_queue(q);
+	blk_mq_quiesce_queue(q);
 
-	wait_event(fdc_wait, cmpxchg(&fdc_busy, 0, 1) == 0);
 	local_irq_save(flags);
 	stdma_lock(floppy_irq, NULL);
 	atari_turnon_irq( IRQ_MFP_FDC ); /* should be already, just to be sure */
@@ -740,16 +744,16 @@ static int do_format(int drive, int type, struct atari_format_descr *desc)
 	if (type) {
 		if (--type >= NUM_DISK_MINORS ||
 		    minor2disktype[type].drive_types > DriveType) {
-			redo_fd_request();
-			return -EINVAL;
+			ret = -EINVAL;
+			goto out;
 		}
 		type = minor2disktype[type].index;
 		UDT = &atari_disk_type[type];
 	}
 
 	if (!UDT || desc->track >= UDT->blocks/UDT->spt/2 || desc->head >= 2) {
-		redo_fd_request();
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out;
 	}
 
 	nsect = UDT->spt;
@@ -788,8 +792,11 @@ static int do_format(int drive, int type, struct atari_format_descr *desc)
 
 	wait_for_completion(&format_wait);
 
-	redo_fd_request();
-	return( FormatError ? -EIO : 0 );	
+	ret = FormatError ? -EIO : 0;
+out:
+	blk_mq_unquiesce_queue(q);
+	blk_mq_unfreeze_queue(q);
+	return ret;
 }
 
 
@@ -819,7 +826,6 @@ static void do_fd_action( int drive )
 		    else {
 			/* all sectors finished */
 			fd_end_request_cur(BLK_STS_OK);
-			redo_fd_request();
 			return;
 		    }
 		}
@@ -1224,7 +1230,6 @@ static void fd_rwsec_done1(int status)
 	else {
 		/* all sectors finished */
 		fd_end_request_cur(BLK_STS_OK);
-		redo_fd_request();
 	}
 	return;
   
@@ -1382,8 +1387,6 @@ static void finish_fdc_done( int dummy )
 
 	local_irq_save(flags);
 	stdma_release();
-	fdc_busy = 0;
-	wake_up( &fdc_wait );
 	local_irq_restore(flags);
 
 	DPRINT(("finish_fdc() finished\n"));
@@ -1473,59 +1476,34 @@ static void setup_req_params( int drive )
 			ReqTrack, ReqSector, (unsigned long)ReqData ));
 }
 
-/*
- * Round-robin between our available drives, doing one request from each
- */
-static struct request *set_next_request(void)
+static blk_status_t ataflop_queue_rq(struct blk_mq_hw_ctx *hctx,
+				     const struct blk_mq_queue_data *bd)
 {
-	struct request_queue *q;
-	int old_pos = fdc_queue;
-	struct request *rq = NULL;
-
-	do {
-		q = unit[fdc_queue].disk->queue;
-		if (++fdc_queue == FD_MAX_UNITS)
-			fdc_queue = 0;
-		if (q) {
-			rq = blk_fetch_request(q);
-			if (rq) {
-				rq->error_count = 0;
-				break;
-			}
-		}
-	} while (fdc_queue != old_pos);
-
-	return rq;
-}
-
+	struct atari_floppy_struct *floppy = bd->rq->rq_disk->private_data;
+	int drive = floppy - unit;
+	int type = floppy->type;
 
-static void redo_fd_request(void)
-{
-	int drive, type;
-	struct atari_floppy_struct *floppy;
+	spin_lock_irq(&ataflop_lock);
+	if (fd_request) {
+		spin_unlock_irq(&ataflop_lock);
+		return BLK_STS_DEV_RESOURCE;
+	}
+	if (!stdma_try_lock(floppy_irq, NULL))  {
+		spin_unlock_irq(&ataflop_lock);
+		return BLK_STS_RESOURCE;
+	}
+	fd_request = bd->rq;
+	blk_mq_start_request(fd_request);
 
-	DPRINT(("redo_fd_request: fd_request=%p dev=%s fd_request->sector=%ld\n",
-		fd_request, fd_request ? fd_request->rq_disk->disk_name : "",
-		fd_request ? blk_rq_pos(fd_request) : 0 ));
+	atari_disable_irq( IRQ_MFP_FDC );
 
 	IsFormatting = 0;
 
-repeat:
-	if (!fd_request) {
-		fd_request = set_next_request();
-		if (!fd_request)
-			goto the_end;
-	}
-
-	floppy = fd_request->rq_disk->private_data;
-	drive = floppy - unit;
-	type = floppy->type;
-	
 	if (!UD.connected) {
 		/* drive not connected */
 		printk(KERN_ERR "Unknown Device: fd%d\n", drive );
 		fd_end_request_cur(BLK_STS_IOERR);
-		goto repeat;
+		goto out;
 	}
 		
 	if (type == 0) {
@@ -1541,23 +1519,18 @@ static void redo_fd_request(void)
 		if (--type >= NUM_DISK_MINORS) {
 			printk(KERN_WARNING "fd%d: invalid disk format", drive );
 			fd_end_request_cur(BLK_STS_IOERR);
-			goto repeat;
+			goto out;
 		}
 		if (minor2disktype[type].drive_types > DriveType)  {
 			printk(KERN_WARNING "fd%d: unsupported disk format", drive );
 			fd_end_request_cur(BLK_STS_IOERR);
-			goto repeat;
+			goto out;
 		}
 		type = minor2disktype[type].index;
 		UDT = &atari_disk_type[type];
 		set_capacity(floppy->disk, UDT->blocks);
 		UD.autoprobe = 0;
 	}
-	
-	if (blk_rq_pos(fd_request) + 1 > UDT->blocks) {
-		fd_end_request_cur(BLK_STS_IOERR);
-		goto repeat;
-	}
 
 	/* stop deselect timer */
 	del_timer( &motor_off_timer );
@@ -1569,22 +1542,13 @@ static void redo_fd_request(void)
 	setup_req_params( drive );
 	do_fd_action( drive );
 
-	return;
-
-  the_end:
-	finish_fdc();
-}
-
-
-void do_fd_request(struct request_queue * q)
-{
-	DPRINT(("do_fd_request for pid %d\n",current->pid));
-	wait_event(fdc_wait, cmpxchg(&fdc_busy, 0, 1) == 0);
-	stdma_lock(floppy_irq, NULL);
-
-	atari_disable_irq( IRQ_MFP_FDC );
-	redo_fd_request();
+	if (bd->last)
+		finish_fdc();
 	atari_enable_irq( IRQ_MFP_FDC );
+
+out:
+	spin_unlock_irq(&ataflop_lock);
+	return BLK_STS_OK;
 }
 
 static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
@@ -1662,7 +1626,6 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
 		/* what if type > 0 here? Overwrite specified entry ? */
 		if (type) {
 		        /* refuse to re-set a predefined type for now */
-			redo_fd_request();
 			return -EINVAL;
 		}
 
@@ -1730,10 +1693,8 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
 
 		/* sanity check */
 		if (setprm.track != dtp->blocks/dtp->spt/2 ||
-		    setprm.head != 2) {
-			redo_fd_request();
+		    setprm.head != 2)
 			return -EINVAL;
-		}
 
 		UDT = dtp;
 		set_capacity(floppy->disk, UDT->blocks);
@@ -1989,6 +1950,10 @@ static const struct block_device_operations floppy_fops = {
 	.revalidate_disk= floppy_revalidate,
 };
 
+static const struct blk_mq_ops ataflop_mq_ops = {
+	.queue_rq = ataflop_queue_rq,
+};
+
 static struct kobject *floppy_find(dev_t dev, int *part, void *data)
 {
 	int drive = *part & 3;
@@ -2002,6 +1967,7 @@ static struct kobject *floppy_find(dev_t dev, int *part, void *data)
 static int __init atari_floppy_init (void)
 {
 	int i;
+	int ret;
 
 	if (!MACH_IS_ATARI)
 		/* Amiga, Mac, ... don't have Atari-compatible floppy :-) */
@@ -2011,14 +1977,30 @@ static int __init atari_floppy_init (void)
 		return -EBUSY;
 
 	for (i = 0; i < FD_MAX_UNITS; i++) {
+		struct blk_mq_tag_set *set;
+
 		unit[i].disk = alloc_disk(1);
-		if (!unit[i].disk)
-			goto Enomem;
+		if (!unit[i].disk) {
+			ret = -ENOMEM;
+			goto err;
+		}
 
-		unit[i].disk->queue = blk_init_queue(do_fd_request,
-						     &ataflop_lock);
-		if (!unit[i].disk->queue)
-			goto Enomem;
+		set = &unit[i].tag_set;
+		set->ops = &ataflop_mq_ops;
+		set->nr_hw_queues = 1;
+		set->queue_depth = 2;
+		set->numa_node = NUMA_NO_NODE;
+		set->flags = BLK_MQ_F_SHOULD_MERGE;
+		ret = blk_mq_alloc_tag_set(set);
+		if (ret)
+			goto err;
+
+		unit[i].disk->queue = blk_mq_init_queue(set);
+		if (IS_ERR(unit[i].disk->queue)) {
+			ret = PTR_ERR(unit[i].disk->queue);
+			unit[i].disk->queue = NULL;
+			goto err;
+		}
 	}
 
 	if (UseTrackbuffer < 0)
@@ -2035,7 +2017,8 @@ static int __init atari_floppy_init (void)
 	DMABuffer = atari_stram_alloc(BUFFER_SIZE+512, "ataflop");
 	if (!DMABuffer) {
 		printk(KERN_ERR "atari_floppy_init: cannot get dma buffer\n");
-		goto Enomem;
+		ret = -ENOMEM;
+		goto err;
 	}
 	TrackBuffer = DMABuffer + 512;
 	PhysDMABuffer = atari_stram_to_phys(DMABuffer);
@@ -2063,7 +2046,8 @@ static int __init atari_floppy_init (void)
 	config_types();
 
 	return 0;
-Enomem:
+
+err:
 	do {
 		struct gendisk *disk = unit[i].disk;
 
@@ -2072,12 +2056,13 @@ static int __init atari_floppy_init (void)
 				blk_cleanup_queue(disk->queue);
 				disk->queue = NULL;
 			}
+			blk_mq_free_tag_set(&unit[i].tag_set);
 			put_disk(unit[i].disk);
 		}
 	} while (i--);
 
 	unregister_blkdev(FLOPPY_MAJOR, "fd");
-	return -ENOMEM;
+	return ret;
 }
 
 #ifndef MODULE
@@ -2124,11 +2109,10 @@ static void __exit atari_floppy_exit(void)
 	int i;
 	blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
 	for (i = 0; i < FD_MAX_UNITS; i++) {
-		struct request_queue *q = unit[i].disk->queue;
-
 		del_gendisk(unit[i].disk);
+		blk_cleanup_queue(unit[i].disk->queue);
+		blk_mq_free_tag_set(&unit[i].tag_set);
 		put_disk(unit[i].disk);
-		blk_cleanup_queue(q);
 	}
 	unregister_blkdev(FLOPPY_MAJOR, "fd");
 
-- 
2.19.1

[PATCH 12/13] floppy: end whole request on error

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

If floppy_end_request() gets passed an error, it should end the whole
request, not just the current segment.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 drivers/block/floppy.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index f2b6f4da1034..acbafd831ea3 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -2210,13 +2210,15 @@ static int do_format(int drive, struct format_descr *tmp_format_req)
 
 static void floppy_end_request(struct request *req, blk_status_t error)
 {
-	unsigned int nr_sectors = current_count_sectors;
+	unsigned int nr_bytes;
 	unsigned int drive = (unsigned long)req->rq_disk->private_data;
 
 	/* current_count_sectors can be zero if transfer failed */
 	if (error)
-		nr_sectors = blk_rq_cur_sectors(req);
-	if (__blk_end_request(req, error, nr_sectors << 9))
+		nr_bytes = blk_rq_bytes(req);
+	else
+		nr_bytes = current_count_sectors << 9;
+	if (__blk_end_request(req, error, nr_bytes))
 		return;
 
 	/* We're done with the request */
-- 
2.19.1

[PATCH 13/13] floppy: convert to blk-mq

[Omar Sandoval]

From: Omar Sandoval <osandov@fb.com>

This driver likes to fetch requests from all over the place, so make
queue_rq put requests on a list so that the logic stays the same. Tested
with QEMU.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 drivers/block/floppy.c | 74 +++++++++++++++++++++++++-----------------
 1 file changed, 44 insertions(+), 30 deletions(-)

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index acbafd831ea3..eb19125beb90 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -252,13 +252,13 @@ static int allowed_drive_mask = 0x33;
 
 static int irqdma_allocated;
 
-#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
 #include <linux/blkpg.h>
 #include <linux/cdrom.h>	/* for the compatibility eject ioctl */
 #include <linux/completion.h>
 
+static LIST_HEAD(floppy_reqs);
 static struct request *current_req;
-static void do_fd_request(struct request_queue *q);
 static int set_next_request(void);
 
 #ifndef fd_get_dma_residue
@@ -414,10 +414,10 @@ static struct floppy_drive_struct drive_state[N_DRIVE];
 static struct floppy_write_errors write_errors[N_DRIVE];
 static struct timer_list motor_off_timer[N_DRIVE];
 static struct gendisk *disks[N_DRIVE];
+static struct blk_mq_tag_set tag_sets[N_DRIVE];
 static struct block_device *opened_bdev[N_DRIVE];
 static DEFINE_MUTEX(open_lock);
 static struct floppy_raw_cmd *raw_cmd, default_raw_cmd;
-static int fdc_queue;
 
 /*
  * This struct defines the different floppy types.
@@ -2218,8 +2218,9 @@ static void floppy_end_request(struct request *req, blk_status_t error)
 		nr_bytes = blk_rq_bytes(req);
 	else
 		nr_bytes = current_count_sectors << 9;
-	if (__blk_end_request(req, error, nr_bytes))
+	if (blk_update_request(req, error, nr_bytes))
 		return;
+	__blk_mq_end_request(req, error);
 
 	/* We're done with the request */
 	floppy_off(drive);
@@ -2799,27 +2800,14 @@ static int make_raw_rw_request(void)
 	return 2;
 }
 
-/*
- * Round-robin between our available drives, doing one request from each
- */
 static int set_next_request(void)
 {
-	struct request_queue *q;
-	int old_pos = fdc_queue;
-
-	do {
-		q = disks[fdc_queue]->queue;
-		if (++fdc_queue == N_DRIVE)
-			fdc_queue = 0;
-		if (q) {
-			current_req = blk_fetch_request(q);
-			if (current_req) {
-				current_req->error_count = 0;
-				break;
-			}
-		}
-	} while (fdc_queue != old_pos);
-
+	current_req = list_first_entry_or_null(&floppy_reqs, struct request,
+					       queuelist);
+	if (current_req) {
+		current_req->error_count = 0;
+		list_del_init(&current_req->queuelist);
+	}
 	return current_req != NULL;
 }
 
@@ -2903,29 +2891,38 @@ static void process_fd_request(void)
 	schedule_bh(redo_fd_request);
 }
 
-static void do_fd_request(struct request_queue *q)
+static blk_status_t floppy_queue_rq(struct blk_mq_hw_ctx *hctx,
+				    const struct blk_mq_queue_data *bd)
 {
+	blk_mq_start_request(bd->rq);
+
 	if (WARN(max_buffer_sectors == 0,
 		 "VFS: %s called on non-open device\n", __func__))
-		return;
+		return BLK_STS_IOERR;
 
 	if (WARN(atomic_read(&usage_count) == 0,
 		 "warning: usage count=0, current_req=%p sect=%ld flags=%llx\n",
 		 current_req, (long)blk_rq_pos(current_req),
 		 (unsigned long long) current_req->cmd_flags))
-		return;
+		return BLK_STS_IOERR;
+
+	spin_lock_irq(&floppy_lock);
+	list_add_tail(&bd->rq->queuelist, &floppy_reqs);
+	spin_unlock_irq(&floppy_lock);
 
 	if (test_and_set_bit(0, &fdc_busy)) {
 		/* fdc busy, this new request will be treated when the
 		   current one is done */
 		is_alive(__func__, "old request running");
-		return;
+		return BLK_STS_OK;
 	}
+
 	command_status = FD_COMMAND_NONE;
 	__reschedule_timeout(MAXTIMEOUT, "fd_request");
 	set_fdc(0);
 	process_fd_request();
 	is_alive(__func__, "");
+	return BLK_STS_OK;
 }
 
 static const struct cont_t poll_cont = {
@@ -4488,6 +4485,10 @@ static struct platform_driver floppy_driver = {
 	},
 };
 
+static const struct blk_mq_ops floppy_mq_ops = {
+	.queue_rq = floppy_queue_rq,
+};
+
 static struct platform_device floppy_device[N_DRIVE];
 
 static bool floppy_available(int drive)
@@ -4529,15 +4530,28 @@ static int __init do_floppy_init(void)
 		return -ENOMEM;
 
 	for (drive = 0; drive < N_DRIVE; drive++) {
+		struct blk_mq_tag_set *set;
+
 		disks[drive] = alloc_disk(1);
 		if (!disks[drive]) {
 			err = -ENOMEM;
 			goto out_put_disk;
 		}
 
-		disks[drive]->queue = blk_init_queue(do_fd_request, &floppy_lock);
-		if (!disks[drive]->queue) {
-			err = -ENOMEM;
+		set = &tag_sets[drive];
+		set->ops = &floppy_mq_ops;
+		set->nr_hw_queues = 1;
+		set->queue_depth = 2;
+		set->numa_node = NUMA_NO_NODE;
+		set->flags = BLK_MQ_F_SHOULD_MERGE;
+		err = blk_mq_alloc_tag_set(set);
+		if (err)
+			goto out_put_disk;
+
+		disks[drive]->queue = blk_mq_init_queue(set);
+		if (IS_ERR(disks[drive]->queue)) {
+			err = PTR_ERR(disks[drive]->queue);
+			disks[drive]->queue = NULL;
 			goto out_put_disk;
 		}
 
-- 
2.19.1

Re: [PATCH 12/13] floppy: end whole request on error

[Jens Axboe]

On 10/11/18 12:30 PM, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> If floppy_end_request() gets passed an error, it should end the whole
> request, not just the current segment.

I don't think this is correct, we should still just end the
individual chunks.

-- 
Jens Axboe

Re: [PATCH 12/13] floppy: end whole request on error

[Omar Sandoval]

On Thu, Oct 11, 2018 at 12:39:51PM -0600, Jens Axboe wrote:
> On 10/11/18 12:30 PM, Omar Sandoval wrote:
> > From: Omar Sandoval <osandov@fb.com>
> > 
> > If floppy_end_request() gets passed an error, it should end the whole
> > request, not just the current segment.
> 
> I don't think this is correct, we should still just end the
> individual chunks.

Yup, I'll drop this and the swim3 equivalent, thanks.