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>
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 02059e9..72d0d70 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -907,7 +907,7 @@
/*
* Issue a new request to a drive from hwgroup
- * Caller must have already done spin_lock_irqsave(&ide_lock, ..);
+ * Caller must have already done spin_lock_irqsave(&hwgroup->lock, ..);
*
* A hwgroup is a serialized group of IDE interfaces. Usually there is
* exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640)
@@ -919,7 +919,7 @@
* possibly along with many other devices. This is especially common in
* PCI-based systems with off-board IDE controller cards.
*
- * The IDE driver uses the single global ide_lock spinlock to protect
+ * The IDE driver uses a per-hwgroup spinlock to protect
* access to the request queues, and to protect the hwgroup->busy flag.
*
* The first thread into the driver for a particular hwgroup sets the
@@ -935,7 +935,7 @@
* will start the next request from the queue. If no more work remains,
* the driver will clear the hwgroup->busy flag and exit.
*
- * The ide_lock (spinlock) is used to protect all access to the
+ * The per-hwgroup spinlock is used to protect all access to the
* hwgroup->busy flag, but is otherwise not needed for most processing in
* the driver. This makes the driver much more friendlier to shared IRQs
* than previous designs, while remaining 100% (?) SMP safe and capable.
@@ -948,7 +948,7 @@
ide_startstop_t startstop;
int loops = 0;
- /* caller must own ide_lock */
+ /* caller must own hwgroup->lock */
BUG_ON(!irqs_disabled());
while (!hwgroup->busy) {
@@ -1070,11 +1070,11 @@
*/
if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
disable_irq_nosync(hwif->irq);
- spin_unlock(&ide_lock);
+ spin_unlock(&hwgroup->lock);
local_irq_enable_in_hardirq();
/* allow other IRQs while we start this request */
startstop = start_request(drive, rq);
- spin_lock_irq(&ide_lock);
+ spin_lock_irq(&hwgroup->lock);
if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
enable_irq(hwif->irq);
if (startstop == ide_stopped)
@@ -1172,7 +1172,7 @@
unsigned long flags;
unsigned long wait = -1;
- spin_lock_irqsave(&ide_lock, flags);
+ spin_lock_irqsave(&hwgroup->lock, flags);
if (((handler = hwgroup->handler) == NULL) ||
(hwgroup->req_gen != hwgroup->req_gen_timer)) {
@@ -1205,7 +1205,7 @@
hwgroup->timer.expires = jiffies + wait;
hwgroup->req_gen_timer = hwgroup->req_gen;
add_timer(&hwgroup->timer);
- spin_unlock_irqrestore(&ide_lock, flags);
+ spin_unlock_irqrestore(&hwgroup->lock, flags);
return;
}
}
@@ -1215,7 +1215,7 @@
* the handler() function, which means we need to
* globally mask the specific IRQ:
*/
- spin_unlock(&ide_lock);
+ spin_unlock(&hwgroup->lock);
hwif = HWIF(drive);
/* disable_irq_nosync ?? */
disable_irq(hwif->irq);
@@ -1239,14 +1239,14 @@
hwif->tp_ops->read_status(hwif));
}
drive->service_time = jiffies - drive->service_start;
- spin_lock_irq(&ide_lock);
+ spin_lock_irq(&hwgroup->lock);
enable_irq(hwif->irq);
if (startstop == ide_stopped)
hwgroup->busy = 0;
}
}
ide_do_request(hwgroup, IDE_NO_IRQ);
- spin_unlock_irqrestore(&ide_lock, flags);
+ spin_unlock_irqrestore(&hwgroup->lock, flags);
}
/**
@@ -1339,14 +1339,13 @@
{
unsigned long flags;
ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id;
- ide_hwif_t *hwif;
+ ide_hwif_t *hwif = hwgroup->hwif;
ide_drive_t *drive;
ide_handler_t *handler;
ide_startstop_t startstop;
irqreturn_t irq_ret = IRQ_NONE;
- spin_lock_irqsave(&ide_lock, flags);
- hwif = hwgroup->hwif;
+ spin_lock_irqsave(&hwgroup->lock, flags);
if (!ide_ack_intr(hwif))
goto out;
@@ -1416,7 +1415,7 @@
hwgroup->handler = NULL;
hwgroup->req_gen++;
del_timer(&hwgroup->timer);
- spin_unlock(&ide_lock);
+ spin_unlock(&hwgroup->lock);
if (hwif->port_ops && hwif->port_ops->clear_irq)
hwif->port_ops->clear_irq(drive);
@@ -1427,7 +1426,7 @@
/* service this interrupt, may set handler for next interrupt */
startstop = handler(drive);
- spin_lock_irq(&ide_lock);
+ spin_lock_irq(&hwgroup->lock);
/*
* Note that handler() may have set things up for another
* interrupt to occur soon, but it cannot happen until
@@ -1448,7 +1447,7 @@
out_handled:
irq_ret = IRQ_HANDLED;
out:
- spin_unlock_irqrestore(&ide_lock, flags);
+ spin_unlock_irqrestore(&hwgroup->lock, flags);
return irq_ret;
}