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, 21 insertions, 11 deletions

diff --git a/drivers/scsi/ide-scsi.c b/drivers/scsi/ide-scsi.c
index 2370fd82ebfe..c24140aff8e7 100644
--- a/drivers/scsi/ide-scsi.c
+++ b/drivers/scsi/ide-scsi.c
@@ -578,6 +578,8 @@ static int idescsi_eh_abort (struct scsi_cmnd *cmd)
 {
         idescsi_scsi_t *scsi  = scsihost_to_idescsi(cmd->device->host);
         ide_drive_t    *drive = scsi->drive;
+        ide_hwif_t     *hwif;
+        ide_hwgroup_t  *hwgroup;
         int             busy;
         int             ret   = FAILED;
 
@@ -594,13 +596,16 @@ static int idescsi_eh_abort (struct scsi_cmnd *cmd)
                 goto no_drive;
         }
 
-        /* First give it some more time, how much is "right" is hard to say :-( */
+        hwif = drive->hwif;
+        hwgroup = hwif->hwgroup;
 
-        busy = ide_wait_not_busy(HWIF(drive), 100);     /* FIXME - uses mdelay which causes latency? */
+        /* First give it some more time, how much is "right" is hard to say :-(
+           FIXME - uses mdelay which causes latency? */
+        busy = ide_wait_not_busy(hwif, 100);
         if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
                 printk (KERN_WARNING "ide-scsi: drive did%s become ready\n", busy?" not":"");
 
-        spin_lock_irq(&ide_lock);
+        spin_lock_irq(&hwgroup->lock);
 
         /* If there is no pc running we're done (our interrupt took care of it) */
         pc = drive->pc;
@@ -629,7 +634,7 @@ static int idescsi_eh_abort (struct scsi_cmnd *cmd)
         }
 
 ide_unlock:
-        spin_unlock_irq(&ide_lock);
+        spin_unlock_irq(&hwgroup->lock);
 no_drive:
         if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
                 printk (KERN_WARNING "ide-scsi: abort returns %s\n", ret == SUCCESS?"success":"failed");
@@ -642,6 +647,7 @@ static int idescsi_eh_reset (struct scsi_cmnd *cmd)
         struct request *req;
         idescsi_scsi_t *scsi  = scsihost_to_idescsi(cmd->device->host);
         ide_drive_t    *drive = scsi->drive;
+        ide_hwgroup_t  *hwgroup;
         int             ready = 0;
         int             ret   = SUCCESS;
 
@@ -658,14 +664,18 @@ static int idescsi_eh_reset (struct scsi_cmnd *cmd)
                 return FAILED;
         }
 
+        hwgroup = drive->hwif->hwgroup;
+
         spin_lock_irq(cmd->device->host->host_lock);
-        spin_lock(&ide_lock);
+        spin_lock(&hwgroup->lock);
 
         pc = drive->pc;
+        if (pc)
+                req = pc->rq;
 
-        if (pc == NULL || (req = pc->rq) != HWGROUP(drive)->rq || !HWGROUP(drive)->handler) {
+        if (pc == NULL || req != hwgroup->rq || hwgroup->handler == NULL) {
                 printk (KERN_WARNING "ide-scsi: No active request in idescsi_eh_reset\n");
-                spin_unlock(&ide_lock);
+                spin_unlock(&hwgroup->lock);
                 spin_unlock_irq(cmd->device->host->host_lock);
                 return FAILED;
         }
@@ -685,10 +695,10 @@ static int idescsi_eh_reset (struct scsi_cmnd *cmd)
                         BUG();
         }
 
-        HWGROUP(drive)->rq = NULL;
-        HWGROUP(drive)->handler = NULL;
-        HWGROUP(drive)->busy = 1;               /* will set this to zero when ide reset finished */
-        spin_unlock(&ide_lock);
+        hwgroup->rq = NULL;
+        hwgroup->handler = NULL;
+        hwgroup->busy = 1; /* will set this to zero when ide reset finished */
+        spin_unlock(&hwgroup->lock);
 
         ide_do_reset(drive);