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path: root/drivers/ide/ide-park.c
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Diffstat (limited to 'drivers/ide/ide-park.c')
-rw-r--r--drivers/ide/ide-park.c121
1 files changed, 121 insertions, 0 deletions
diff --git a/drivers/ide/ide-park.c b/drivers/ide/ide-park.c
new file mode 100644
index 00000000000..03b00e57e93
--- /dev/null
+++ b/drivers/ide/ide-park.c
@@ -0,0 +1,121 @@
+#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)
+{
+ struct request_queue *q = drive->queue;
+ struct request *rq;
+ int rc;
+
+ timeout += jiffies;
+ spin_lock_irq(&ide_lock);
+ if (drive->dev_flags & IDE_DFLAG_PARKED) {
+ ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;
+ int reset_timer;
+
+ reset_timer = time_before(timeout, drive->sleep);
+ drive->sleep = timeout;
+ wake_up_all(&ide_park_wq);
+ if (reset_timer && hwgroup->sleeping &&
+ del_timer(&hwgroup->timer)) {
+ hwgroup->sleeping = 0;
+ hwgroup->busy = 0;
+ blk_start_queueing(q);
+ }
+ spin_unlock_irq(&ide_lock);
+ return;
+ }
+ spin_unlock_irq(&ide_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);
+ unsigned long now;
+ unsigned int msecs;
+
+ if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
+ return -EOPNOTSUPP;
+
+ spin_lock_irq(&ide_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);
+
+ 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;
+}