ide: replace the global ide_lock spinlock by per-hwgroup spinlocks (v2)

Now that (almost) all host drivers have been fixed not to abuse ide_lock
and core code usage of ide_lock has been sanitized we may safely replace
ide_lock by per-hwgroup locks.

This patch is partially based on earlier patch from Ravikiran G Thirumalai.

While at it:
- don't use deprecated HWIF() and HWGROUP() macros
- update locking documentation in ide.h

v2:
Add missing spin_lock_init(&hwgroup->lock).  (Noticed by Elias Oltmanns)

Cc: Vaibhav V. Nivargi <vaibhav.nivargi@gmail.com>
Cc: Alok N. Kataria <alokk@calsoftinc.com>
Cc: Shai Fultheim <shai@scalex86.org>
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: Elias Oltmanns <eo@nebensachen.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 15 insertions, 11 deletions

diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index c55bdbd22314..504bc9480e93 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -906,7 +906,8 @@ static int ide_init_queue(ide_drive_t *drive)
          *      do not.
          */
 
-        q = blk_init_queue_node(do_ide_request, &ide_lock, hwif_to_node(hwif));
+        q = blk_init_queue_node(do_ide_request, &hwif->hwgroup->lock,
+                                hwif_to_node(hwif));
         if (!q)
                 return 1;
 
@@ -947,7 +948,7 @@ static void ide_add_drive_to_hwgroup(ide_drive_t *drive)
 {
         ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;
 
-        spin_lock_irq(&ide_lock);
+        spin_lock_irq(&hwgroup->lock);
         if (!hwgroup->drive) {
                 /* first drive for hwgroup. */
                 drive->next = drive;
@@ -957,7 +958,7 @@ static void ide_add_drive_to_hwgroup(ide_drive_t *drive)
                 drive->next = hwgroup->drive->next;
                 hwgroup->drive->next = drive;
         }
-        spin_unlock_irq(&ide_lock);
+        spin_unlock_irq(&hwgroup->lock);
 }
 
 /*
@@ -1002,7 +1003,7 @@ void ide_remove_port_from_hwgroup(ide_hwif_t *hwif)
 
         ide_ports[hwif->index] = NULL;
 
-        spin_lock_irq(&ide_lock);
+        spin_lock_irq(&hwgroup->lock);
         /*
          * Remove us from the hwgroup, and free
          * the hwgroup if we were the only member
@@ -1030,7 +1031,7 @@ void ide_remove_port_from_hwgroup(ide_hwif_t *hwif)
                 }
                 BUG_ON(hwgroup->hwif == hwif);
         }
-        spin_unlock_irq(&ide_lock);
+        spin_unlock_irq(&hwgroup->lock);
 }
 
 /*
@@ -1092,17 +1093,19 @@ static int init_irq (ide_hwif_t *hwif)
                  * linked list, the first entry is the hwif that owns
                  * hwgroup->handler - do not change that.
                  */
-                spin_lock_irq(&ide_lock);
+                spin_lock_irq(&hwgroup->lock);
                 hwif->next = hwgroup->hwif->next;
                 hwgroup->hwif->next = hwif;
                 BUG_ON(hwif->next == hwif);
-                spin_unlock_irq(&ide_lock);
+                spin_unlock_irq(&hwgroup->lock);
         } else {
                 hwgroup = kmalloc_node(sizeof(*hwgroup), GFP_KERNEL|__GFP_ZERO,
                                        hwif_to_node(hwif));
                 if (hwgroup == NULL)
                         goto out_up;
 
+                spin_lock_init(&hwgroup->lock);
+
                 hwif->hwgroup = hwgroup;
                 hwgroup->hwif = hwif->next = hwif;
 
@@ -1263,20 +1266,21 @@ static void ide_remove_drive_from_hwgroup(ide_drive_t *drive)
 static void drive_release_dev (struct device *dev)
 {
         ide_drive_t *drive = container_of(dev, ide_drive_t, gendev);
+        ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;
 
         ide_proc_unregister_device(drive);
 
-        spin_lock_irq(&ide_lock);
+        spin_lock_irq(&hwgroup->lock);
         ide_remove_drive_from_hwgroup(drive);
         kfree(drive->id);
         drive->id = NULL;
         drive->dev_flags &= ~IDE_DFLAG_PRESENT;
         /* Messed up locking ... */
-        spin_unlock_irq(&ide_lock);
+        spin_unlock_irq(&hwgroup->lock);
         blk_cleanup_queue(drive->queue);
-        spin_lock_irq(&ide_lock);
+        spin_lock_irq(&hwgroup->lock);
         drive->queue = NULL;
-        spin_unlock_irq(&ide_lock);
+        spin_unlock_irq(&hwgroup->lock);
 
         complete(&drive->gendev_rel_comp);
 }