Commit 2a2ca6a9 authored by Bartlomiej Zolnierkiewicz's avatar Bartlomiej Zolnierkiewicz
Browse files

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: default avatarRavikiran Thirumalai <kiran@scalex86.org>
Cc: Elias Oltmanns <eo@nebensachen.de>
Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
parent 6ea52226

drivers/ide/ide-io.c

+16 −17
Original line number Diff line number Diff line
@@ -907,7 +907,7 @@ repeat: 


/*

 * 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 @@ repeat: 
 * 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 @@ repeat: 
 * 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 @@ static void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq) 
	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 @@ static void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq) 
		 */

		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 @@ void ide_timer_expiry (unsigned long data) 
	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 @@ void ide_timer_expiry (unsigned long data) 
					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 @@ void ide_timer_expiry (unsigned long data) 
			 * 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 @@ void ide_timer_expiry (unsigned long data) 
						  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 @@ irqreturn_t ide_intr (int irq, void *dev_id) 
{

	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 @@ irqreturn_t ide_intr (int irq, void *dev_id) 
	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 @@ irqreturn_t ide_intr (int irq, void *dev_id) 
	/* 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 @@ irqreturn_t ide_intr (int irq, void *dev_id) 
out_handled:

	irq_ret = IRQ_HANDLED;

out:

	spin_unlock_irqrestore(&ide_lock, flags);

	spin_unlock_irqrestore(&hwgroup->lock, flags);

	return irq_ret;

}

drivers/ide/ide-iops.c

+23 −25
Original line number Diff line number Diff line
@@ -835,10 +835,12 @@ static void __ide_set_handler (ide_drive_t *drive, ide_handler_t *handler, 
void ide_set_handler (ide_drive_t *drive, ide_handler_t *handler,

		      unsigned int timeout, ide_expiry_t *expiry)

{

	ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;

	unsigned long flags;

	spin_lock_irqsave(&ide_lock, flags);



	spin_lock_irqsave(&hwgroup->lock, flags);

	__ide_set_handler(drive, handler, timeout, expiry);

	spin_unlock_irqrestore(&ide_lock, flags);

	spin_unlock_irqrestore(&hwgroup->lock, flags);

}



EXPORT_SYMBOL(ide_set_handler);
@@ -860,10 +862,11 @@ EXPORT_SYMBOL(ide_set_handler); 
void ide_execute_command(ide_drive_t *drive, u8 cmd, ide_handler_t *handler,

			 unsigned timeout, ide_expiry_t *expiry)

{

	ide_hwif_t *hwif = drive->hwif;

	ide_hwgroup_t *hwgroup = hwif->hwgroup;

	unsigned long flags;

	ide_hwif_t *hwif = HWIF(drive);



	spin_lock_irqsave(&ide_lock, flags);

	spin_lock_irqsave(&hwgroup->lock, flags);

	__ide_set_handler(drive, handler, timeout, expiry);

	hwif->tp_ops->exec_command(hwif, cmd);

	/*
@@ -873,19 +876,20 @@ void ide_execute_command(ide_drive_t *drive, u8 cmd, ide_handler_t *handler, 
	 * FIXME: we could skip this delay with care on non shared devices

	 */

	ndelay(400);

	spin_unlock_irqrestore(&ide_lock, flags);

	spin_unlock_irqrestore(&hwgroup->lock, flags);

}

EXPORT_SYMBOL(ide_execute_command);



void ide_execute_pkt_cmd(ide_drive_t *drive)

{

	ide_hwif_t *hwif = drive->hwif;

	ide_hwgroup_t *hwgroup = hwif->hwgroup;

	unsigned long flags;



	spin_lock_irqsave(&ide_lock, flags);

	spin_lock_irqsave(&hwgroup->lock, flags);

	hwif->tp_ops->exec_command(hwif, ATA_CMD_PACKET);

	ndelay(400);

	spin_unlock_irqrestore(&ide_lock, flags);

	spin_unlock_irqrestore(&hwgroup->lock, flags);

}

EXPORT_SYMBOL_GPL(ide_execute_pkt_cmd);
@@ -1076,22 +1080,16 @@ static void pre_reset(ide_drive_t *drive) 
 */

static ide_startstop_t do_reset1 (ide_drive_t *drive, int do_not_try_atapi)

{

	unsigned int unit;

	unsigned long flags, timeout;

	ide_hwif_t *hwif;

	ide_hwgroup_t *hwgroup;

	struct ide_io_ports *io_ports;

	const struct ide_tp_ops *tp_ops;

	ide_hwif_t *hwif = drive->hwif;

	ide_hwgroup_t *hwgroup = hwif->hwgroup;

	struct ide_io_ports *io_ports = &hwif->io_ports;

	const struct ide_tp_ops *tp_ops = hwif->tp_ops;

	const struct ide_port_ops *port_ops;

	unsigned long flags, timeout;

	unsigned int unit;

	DEFINE_WAIT(wait);



	spin_lock_irqsave(&ide_lock, flags);

	hwif = HWIF(drive);

	hwgroup = HWGROUP(drive);



	io_ports = &hwif->io_ports;



	tp_ops = hwif->tp_ops;

	spin_lock_irqsave(&hwgroup->lock, flags);



	/* We must not reset with running handlers */

	BUG_ON(hwgroup->handler != NULL);
@@ -1106,7 +1104,7 @@ static ide_startstop_t do_reset1 (ide_drive_t *drive, int do_not_try_atapi) 
		hwgroup->poll_timeout = jiffies + WAIT_WORSTCASE;

		hwgroup->polling = 1;

		__ide_set_handler(drive, &atapi_reset_pollfunc, HZ/20, NULL);

		spin_unlock_irqrestore(&ide_lock, flags);

		spin_unlock_irqrestore(&hwgroup->lock, flags);

		return ide_started;

	}
@@ -1129,9 +1127,9 @@ static ide_startstop_t do_reset1 (ide_drive_t *drive, int do_not_try_atapi) 
		if (time_before_eq(timeout, now))

			break;



		spin_unlock_irqrestore(&ide_lock, flags);

		spin_unlock_irqrestore(&hwgroup->lock, flags);

		timeout = schedule_timeout_uninterruptible(timeout - now);

		spin_lock_irqsave(&ide_lock, flags);

		spin_lock_irqsave(&hwgroup->lock, flags);

	} while (timeout);

	finish_wait(&ide_park_wq, &wait);
@@ -1143,7 +1141,7 @@ static ide_startstop_t do_reset1 (ide_drive_t *drive, int do_not_try_atapi) 
		pre_reset(&hwif->drives[unit]);



	if (io_ports->ctl_addr == 0) {

		spin_unlock_irqrestore(&ide_lock, flags);

		spin_unlock_irqrestore(&hwgroup->lock, flags);

		ide_complete_drive_reset(drive, -ENXIO);

		return ide_stopped;

	}
@@ -1179,7 +1177,7 @@ static ide_startstop_t do_reset1 (ide_drive_t *drive, int do_not_try_atapi) 
	if (port_ops && port_ops->resetproc)

		port_ops->resetproc(drive);



	spin_unlock_irqrestore(&ide_lock, flags);

	spin_unlock_irqrestore(&hwgroup->lock, flags);

	return ide_started;

}

drivers/ide/ide-park.c

+8 −8
Original line number Diff line number Diff line
@@ -7,17 +7,16 @@ DECLARE_WAIT_QUEUE_HEAD(ide_park_wq); 


static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)

{

	ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;

	struct request_queue *q = drive->queue;

	struct request *rq;

	int rc;



	timeout += jiffies;

	spin_lock_irq(&ide_lock);

	spin_lock_irq(&hwgroup->lock);

	if (drive->dev_flags & IDE_DFLAG_PARKED) {

		ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;

		int reset_timer;

		int reset_timer = time_before(timeout, drive->sleep);



		reset_timer = time_before(timeout, drive->sleep);

		drive->sleep = timeout;

		wake_up_all(&ide_park_wq);

		if (reset_timer && hwgroup->sleeping &&
@@ -26,10 +25,10 @@ static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout) 
			hwgroup->busy = 0;

			blk_start_queueing(q);

		}

		spin_unlock_irq(&ide_lock);

		spin_unlock_irq(&hwgroup->lock);

		return;

	}

	spin_unlock_irq(&ide_lock);

	spin_unlock_irq(&hwgroup->lock);



	rq = blk_get_request(q, READ, __GFP_WAIT);

	rq->cmd[0] = REQ_PARK_HEADS;
@@ -62,20 +61,21 @@ ssize_t ide_park_show(struct device *dev, struct device_attribute *attr, 
		      char *buf)

{

	ide_drive_t *drive = to_ide_device(dev);

	ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;

	unsigned long now;

	unsigned int msecs;



	if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)

		return -EOPNOTSUPP;



	spin_lock_irq(&ide_lock);

	spin_lock_irq(&hwgroup->lock);

	now = jiffies;

	if (drive->dev_flags & IDE_DFLAG_PARKED &&

	    time_after(drive->sleep, now))

		msecs = jiffies_to_msecs(drive->sleep - now);

	else

		msecs = 0;

	spin_unlock_irq(&ide_lock);

	spin_unlock_irq(&hwgroup->lock);



	return snprintf(buf, 20, "%u\n", msecs);

}

drivers/ide/ide-probe.c

+15 −11
Original line number Diff line number Diff line
@@ -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);

}

drivers/ide/ide.c

+3 −5
Original line number Diff line number Diff line
@@ -74,9 +74,6 @@ static const u8 ide_hwif_to_major[] = { IDE0_MAJOR, IDE1_MAJOR, 


DEFINE_MUTEX(ide_cfg_mtx);



__cacheline_aligned_in_smp DEFINE_SPINLOCK(ide_lock);

EXPORT_SYMBOL(ide_lock);



static void ide_port_init_devices_data(ide_hwif_t *);



/*
@@ -333,6 +330,7 @@ static int set_pio_mode_abuse(ide_hwif_t *hwif, u8 req_pio) 
static int set_pio_mode(ide_drive_t *drive, int arg)

{

	ide_hwif_t *hwif = drive->hwif;

	ide_hwgroup_t *hwgroup = hwif->hwgroup;

	const struct ide_port_ops *port_ops = hwif->port_ops;



	if (arg < 0 || arg > 255)
@@ -347,9 +345,9 @@ static int set_pio_mode(ide_drive_t *drive, int arg) 
			unsigned long flags;



			/* take lock for IDE_DFLAG_[NO_]UNMASK/[NO_]IO_32BIT */

			spin_lock_irqsave(&ide_lock, flags);

			spin_lock_irqsave(&hwgroup->lock, flags);

			port_ops->set_pio_mode(drive, arg);

			spin_unlock_irqrestore(&ide_lock, flags);

			spin_unlock_irqrestore(&hwgroup->lock, flags);

		} else

			port_ops->set_pio_mode(drive, arg);

	} else {

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