ide: add ide_[un]lock_hwgroup() helpers

Add ide_[un]lock_hwgroup() inline helpers for obtaining exclusive
access to the given hwgroup and update the core code accordingly.

[ This change besides making code saner results in more efficient
  use of ide_{get,release}_lock(). ]

Cc: Michael Schmitz <schmitz@biophys.uni-duesseldorf.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Elias Oltmanns <eo@nebensachen.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

3 files changed, 32 insertions, 22 deletions

diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index c60512196f61..ab480042757a 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -790,10 +790,7 @@ void do_ide_request(struct request_queue *q)
         /* caller must own hwgroup->lock */
         BUG_ON(!irqs_disabled());
 
-        while (!hwgroup->busy) {
-                hwgroup->busy = 1;
-                /* for atari only */
-                ide_get_lock(ide_intr, hwgroup);
+        while (!ide_lock_hwgroup(hwgroup)) {
                 drive = choose_drive(hwgroup);
                 if (drive == NULL) {
                         int sleeping = 0;
@@ -825,17 +822,10 @@ void do_ide_request(struct request_queue *q)
                                 hwgroup->sleeping = 1;
                                 hwgroup->req_gen_timer = hwgroup->req_gen;
                                 mod_timer(&hwgroup->timer, sleep);
-                                /* we purposely leave hwgroup->busy==1
+                                /* we purposely leave hwgroup locked
                                  * while sleeping */
-                        } else {
-                                /* Ugly, but how can we sleep for the lock
-                                 * otherwise? perhaps from tq_disk?
-                                 */
-
-                                /* for atari only */
-                                ide_release_lock();
-                                hwgroup->busy = 0;
-                        }
+                        } else
+                                ide_unlock_hwgroup(hwgroup);
 
                         /* no more work for this hwgroup (for now) */
                         goto plug_device;
@@ -865,7 +855,7 @@ void do_ide_request(struct request_queue *q)
                  */
                 rq = elv_next_request(drive->queue);
                 if (!rq) {
-                        hwgroup->busy = 0;
+                        ide_unlock_hwgroup(hwgroup);
                         break;
                 }
 
@@ -885,8 +875,8 @@ void do_ide_request(struct request_queue *q)
                 if ((drive->dev_flags & IDE_DFLAG_BLOCKED) &&
                     blk_pm_request(rq) == 0 &&
                     (rq->cmd_flags & REQ_PREEMPT) == 0) {
-                        /* We clear busy, there should be no pending ATA command at this point. */
-                        hwgroup->busy = 0;
+                        /* there should be no pending command at this point */
+                        ide_unlock_hwgroup(hwgroup);
                         goto plug_device;
                 }
 
@@ -897,7 +887,7 @@ void do_ide_request(struct request_queue *q)
                 spin_lock_irq(&hwgroup->lock);
 
                 if (startstop == ide_stopped) {
-                        hwgroup->busy = 0;
+                        ide_unlock_hwgroup(hwgroup);
                         if (!elv_queue_empty(orig_drive->queue))
                                 blk_plug_device(orig_drive->queue);
                 }
@@ -1001,7 +991,7 @@ void ide_timer_expiry (unsigned long data)
                  */
                 if (hwgroup->sleeping) {
                         hwgroup->sleeping = 0;
-                        hwgroup->busy = 0;
+                        ide_unlock_hwgroup(hwgroup);
                 }
         } else {
                 ide_drive_t *drive = hwgroup->drive;
@@ -1056,7 +1046,7 @@ void ide_timer_expiry (unsigned long data)
                         spin_lock_irq(&hwgroup->lock);
                         enable_irq(hwif->irq);
                         if (startstop == ide_stopped) {
-                                hwgroup->busy = 0;
+                                ide_unlock_hwgroup(hwgroup);
                                 if (!elv_queue_empty(drive->queue))
                                         blk_plug_device(drive->queue);
                         }
@@ -1249,7 +1239,7 @@ irqreturn_t ide_intr (int irq, void *dev_id)
         drive->service_time = jiffies - drive->service_start;
         if (startstop == ide_stopped) {
                 if (hwgroup->handler == NULL) { /* paranoia */
-                        hwgroup->busy = 0;
+                        ide_unlock_hwgroup(hwgroup);
                         if (!elv_queue_empty(drive->queue))
                                 blk_plug_device(drive->queue);
                 } else
diff --git a/drivers/ide/ide-park.c b/drivers/ide/ide-park.c
index 63d01c55f865..44c6787f8aeb 100644
--- a/drivers/ide/ide-park.c
+++ b/drivers/ide/ide-park.c
@@ -22,7 +22,7 @@ static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)
                 if (reset_timer && hwgroup->sleeping &&
                     del_timer(&hwgroup->timer)) {
                         hwgroup->sleeping = 0;
-                        hwgroup->busy = 0;
+                        ide_unlock_hwgroup(hwgroup);
                         blk_start_queueing(q);
                 }
                 spin_unlock_irq(&hwgroup->lock);
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 968ca8f60531..f408d6123f14 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -1280,6 +1280,26 @@ extern void ide_stall_queue(ide_drive_t *drive, unsigned long timeout);
 
 extern void ide_timer_expiry(unsigned long);
 extern irqreturn_t ide_intr(int irq, void *dev_id);
+
+static inline int ide_lock_hwgroup(ide_hwgroup_t *hwgroup)
+{
+        if (hwgroup->busy)
+                return 1;
+
+        hwgroup->busy = 1;
+        /* for atari only */
+        ide_get_lock(ide_intr, hwgroup);
+
+        return 0;
+}
+
+static inline void ide_unlock_hwgroup(ide_hwgroup_t *hwgroup)
+{
+        /* for atari only */
+        ide_release_lock();
+        hwgroup->busy = 0;
+}
+
 extern void do_ide_request(struct request_queue *);
 
 void ide_init_disk(struct gendisk *, ide_drive_t *);