paride: convert pcd to blk-mq

Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 56 insertions, 32 deletions

diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c
index a026211afb51..96670eefaeb2 100644
--- a/drivers/block/paride/pcd.c
+++ b/drivers/block/paride/pcd.c
@@ -137,7 +137,7 @@ enum {D_PRT, D_PRO, D_UNI, D_MOD, D_SLV, D_DLY};
 #include <linux/delay.h>
 #include <linux/cdrom.h>
 #include <linux/spinlock.h>
-#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
 #include <linux/mutex.h>
 #include <linux/uaccess.h>
 
@@ -186,7 +186,8 @@ static int pcd_packet(struct cdrom_device_info *cdi,
 static int pcd_detect(void);
 static void pcd_probe_capabilities(void);
 static void do_pcd_read_drq(void);
-static void do_pcd_request(struct request_queue * q);
+static blk_status_t pcd_queue_rq(struct blk_mq_hw_ctx *hctx,
+                                 const struct blk_mq_queue_data *bd);
 static void do_pcd_read(void);
 
 struct pcd_unit {
@@ -199,6 +200,8 @@ struct pcd_unit {
         char *name;             /* pcd0, pcd1, etc */
         struct cdrom_device_info info;  /* uniform cdrom interface */
         struct gendisk *disk;
+        struct blk_mq_tag_set tag_set;
+        struct list_head rq_list;
 };
 
 static struct pcd_unit pcd[PCD_UNITS];
@@ -292,6 +295,10 @@ static const struct cdrom_device_ops pcd_dops = {
                           CDC_CD_RW,
 };
 
+static const struct blk_mq_ops pcd_mq_ops = {
+        .queue_rq       = pcd_queue_rq,
+};
+
 static void pcd_init_units(void)
 {
         struct pcd_unit *cd;
@@ -300,13 +307,19 @@ static void pcd_init_units(void)
         pcd_drive_count = 0;
         for (unit = 0, cd = pcd; unit < PCD_UNITS; unit++, cd++) {
                 struct gendisk *disk = alloc_disk(1);
+
                 if (!disk)
                         continue;
-                disk->queue = blk_init_queue(do_pcd_request, &pcd_lock);
-                if (!disk->queue) {
-                        put_disk(disk);
+
+                disk->queue = blk_mq_init_sq_queue(&cd->tag_set, &pcd_mq_ops,
+                                                   1, BLK_MQ_F_SHOULD_MERGE);
+                if (IS_ERR(disk->queue)) {
+                        disk->queue = NULL;
                         continue;
                 }
+
+                INIT_LIST_HEAD(&cd->rq_list);
+                disk->queue->queuedata = cd;
                 blk_queue_bounce_limit(disk->queue, BLK_BOUNCE_HIGH);
                 cd->disk = disk;
                 cd->pi = &cd->pia;
@@ -748,18 +761,18 @@ static int pcd_queue;
 static int set_next_request(void)
 {
         struct pcd_unit *cd;
-        struct request_queue *q;
         int old_pos = pcd_queue;
 
         do {
                 cd = &pcd[pcd_queue];
-                q = cd->present ? cd->disk->queue : NULL;
                 if (++pcd_queue == PCD_UNITS)
                         pcd_queue = 0;
-                if (q) {
-                        pcd_req = blk_fetch_request(q);
-                        if (pcd_req)
-                                break;
+                if (cd->present && !list_empty(&cd->rq_list)) {
+                        pcd_req = list_first_entry(&cd->rq_list, struct request,
+                                                        queuelist);
+                        list_del_init(&pcd_req->queuelist);
+                        blk_mq_start_request(pcd_req);
+                        break;
                 }
         } while (pcd_queue != old_pos);
 
@@ -768,33 +781,41 @@ static int set_next_request(void)
 
 static void pcd_request(void)
 {
+        struct pcd_unit *cd;
+
         if (pcd_busy)
                 return;
-        while (1) {
-                if (!pcd_req && !set_next_request())
-                        return;
 
-                if (rq_data_dir(pcd_req) == READ) {
-                        struct pcd_unit *cd = pcd_req->rq_disk->private_data;
-                        if (cd != pcd_current)
-                                pcd_bufblk = -1;
-                        pcd_current = cd;
-                        pcd_sector = blk_rq_pos(pcd_req);
-                        pcd_count = blk_rq_cur_sectors(pcd_req);
-                        pcd_buf = bio_data(pcd_req->bio);
-                        pcd_busy = 1;
-                        ps_set_intr(do_pcd_read, NULL, 0, nice);
-                        return;
-                } else {
-                        __blk_end_request_all(pcd_req, BLK_STS_IOERR);
-                        pcd_req = NULL;
-                }
-        }
+        if (!pcd_req && !set_next_request())
+                return;
+
+        cd = pcd_req->rq_disk->private_data;
+        if (cd != pcd_current)
+                pcd_bufblk = -1;
+        pcd_current = cd;
+        pcd_sector = blk_rq_pos(pcd_req);
+        pcd_count = blk_rq_cur_sectors(pcd_req);
+        pcd_buf = bio_data(pcd_req->bio);
+        pcd_busy = 1;
+        ps_set_intr(do_pcd_read, NULL, 0, nice);
 }
 
-static void do_pcd_request(struct request_queue *q)
+static blk_status_t pcd_queue_rq(struct blk_mq_hw_ctx *hctx,
+                                 const struct blk_mq_queue_data *bd)
 {
+        struct pcd_unit *cd = hctx->queue->queuedata;
+
+        if (rq_data_dir(bd->rq) != READ) {
+                blk_mq_start_request(bd->rq);
+                return BLK_STS_IOERR;
+        }
+
+        spin_lock_irq(&pcd_lock);
+        list_add_tail(&bd->rq->queuelist, &cd->rq_list);
         pcd_request();
+        spin_unlock_irq(&pcd_lock);
+
+        return BLK_STS_OK;
 }
 
 static inline void next_request(blk_status_t err)
@@ -802,8 +823,10 @@ static inline void next_request(blk_status_t err)
         unsigned long saved_flags;
 
         spin_lock_irqsave(&pcd_lock, saved_flags);
-        if (!__blk_end_request_cur(pcd_req, err))
+        if (!blk_update_request(pcd_req, err, blk_rq_cur_bytes(pcd_req))) {
+                __blk_mq_end_request(pcd_req, err);
                 pcd_req = NULL;
+        }
         pcd_busy = 0;
         pcd_request();
         spin_unlock_irqrestore(&pcd_lock, saved_flags);
@@ -1011,6 +1034,7 @@ static void __exit pcd_exit(void)
                         unregister_cdrom(&cd->info);
                 }
                 blk_cleanup_queue(cd->disk->queue);
+                blk_mq_free_tag_set(&cd->tag_set);
                 put_disk(cd->disk);
         }
         unregister_blkdev(major, name);