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linux/drivers/ide/ide-park.c
Bartlomiej Zolnierkiewicz 201bffa464 ide: use per-device request queue locks (v2)
* Move hack for flush requests from choose_drive() to do_ide_request().

* Add ide_plug_device() helper and convert core IDE code from using
  per-hwgroup lock as a request lock to use the ->queue_lock instead.

* Remove no longer needed:
  - choose_drive() function
  - WAKEUP() macro
  - 'sleeping' flag from ide_hwif_t
  - 'service_{start,time}' fields from ide_drive_t

This patch results in much simpler and more maintainable code
(besides being a scalability improvement).

v2:
* Fixes/improvements based on review from Elias:
  - take as many requests off the queue as possible
  - remove now redundant BUG_ON()

Cc: Elias Oltmanns <eo@nebensachen.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2009-01-02 16:12:50 +01:00

125 lines
2.8 KiB
C

#include <linux/kernel.h>
#include <linux/ide.h>
#include <linux/jiffies.h>
#include <linux/blkdev.h>
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(&hwgroup->lock);
if (drive->dev_flags & IDE_DFLAG_PARKED) {
int reset_timer = time_before(timeout, drive->sleep);
int start_queue = 0;
drive->sleep = timeout;
wake_up_all(&ide_park_wq);
if (reset_timer && del_timer(&hwgroup->timer))
start_queue = 1;
spin_unlock_irq(&hwgroup->lock);
if (start_queue) {
spin_lock_irq(q->queue_lock);
blk_start_queueing(q);
spin_unlock_irq(q->queue_lock);
}
return;
}
spin_unlock_irq(&hwgroup->lock);
rq = blk_get_request(q, READ, __GFP_WAIT);
rq->cmd[0] = REQ_PARK_HEADS;
rq->cmd_len = 1;
rq->cmd_type = REQ_TYPE_SPECIAL;
rq->special = &timeout;
rc = blk_execute_rq(q, NULL, rq, 1);
blk_put_request(rq);
if (rc)
goto out;
/*
* Make sure that *some* command is sent to the drive after the
* timeout has expired, so power management will be reenabled.
*/
rq = blk_get_request(q, READ, GFP_NOWAIT);
if (unlikely(!rq))
goto out;
rq->cmd[0] = REQ_UNPARK_HEADS;
rq->cmd_len = 1;
rq->cmd_type = REQ_TYPE_SPECIAL;
elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 1);
out:
return;
}
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(&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(&hwgroup->lock);
return snprintf(buf, 20, "%u\n", msecs);
}
ssize_t ide_park_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t len)
{
#define MAX_PARK_TIMEOUT 30000
ide_drive_t *drive = to_ide_device(dev);
long int input;
int rc;
rc = strict_strtol(buf, 10, &input);
if (rc || input < -2)
return -EINVAL;
if (input > MAX_PARK_TIMEOUT) {
input = MAX_PARK_TIMEOUT;
rc = -EOVERFLOW;
}
mutex_lock(&ide_setting_mtx);
if (input >= 0) {
if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
rc = -EOPNOTSUPP;
else if (input || drive->dev_flags & IDE_DFLAG_PARKED)
issue_park_cmd(drive, msecs_to_jiffies(input));
} else {
if (drive->media == ide_disk)
switch (input) {
case -1:
drive->dev_flags &= ~IDE_DFLAG_NO_UNLOAD;
break;
case -2:
drive->dev_flags |= IDE_DFLAG_NO_UNLOAD;
break;
}
else
rc = -EOPNOTSUPP;
}
mutex_unlock(&ide_setting_mtx);
return rc ? rc : len;
}