drivers/ide/ide-park.c

   1 #include <linux/kernel.h>
   2 #include <linux/ide.h>
   3 #include <linux/jiffies.h>
   4 #include <linux/blkdev.h>
   5
   6 DECLARE_WAIT_QUEUE_HEAD(ide_park_wq);
   7
   8 static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)
   9 {
  10         ide_hwif_t *hwif = drive->hwif;
  11         struct request_queue *q = drive->queue;
  12         struct request *rq;
  13         int rc;
  14
  15         timeout += jiffies;
  16         spin_lock_irq(&hwif->lock);
  17         if (drive->dev_flags & IDE_DFLAG_PARKED) {
  18                 int reset_timer = time_before(timeout, drive->sleep);
  19                 int start_queue = 0;
  20
  21                 drive->sleep = timeout;
  22                 wake_up_all(&ide_park_wq);
  23                 if (reset_timer && del_timer(&hwif->timer))
  24                         start_queue = 1;
  25                 spin_unlock_irq(&hwif->lock);
  26
  27                 if (start_queue) {
  28                         spin_lock_irq(q->queue_lock);
  29                         blk_start_queueing(q);
  30                         spin_unlock_irq(q->queue_lock);
  31                 }
  32                 return;
  33         }
  34         spin_unlock_irq(&hwif->lock);
  35
  36         rq = blk_get_request(q, READ, __GFP_WAIT);
  37         rq->cmd[0] = REQ_PARK_HEADS;
  38         rq->cmd_len = 1;
  39         rq->cmd_type = REQ_TYPE_SPECIAL;
  40         rq->special = &timeout;
  41         rc = blk_execute_rq(q, NULL, rq, 1);
  42         blk_put_request(rq);
  43         if (rc)
  44                 goto out;
  45
  46         /*
  47          * Make sure that *some* command is sent to the drive after the
  48          * timeout has expired, so power management will be reenabled.
  49          */
  50         rq = blk_get_request(q, READ, GFP_NOWAIT);
  51         if (unlikely(!rq))
  52                 goto out;
  53
  54         rq->cmd[0] = REQ_UNPARK_HEADS;
  55         rq->cmd_len = 1;
  56         rq->cmd_type = REQ_TYPE_SPECIAL;
  57         elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 1);
  58
  59 out:
  60         return;
  61 }
  62
  63 ide_startstop_t ide_do_park_unpark(ide_drive_t *drive, struct request *rq)
  64 {
  65         struct ide_cmd cmd;
  66         struct ide_taskfile *tf = &cmd.tf;
  67
  68         memset(&cmd, 0, sizeof(cmd));
  69         if (rq->cmd[0] == REQ_PARK_HEADS) {
  70                 drive->sleep = *(unsigned long *)rq->special;
  71                 drive->dev_flags |= IDE_DFLAG_SLEEPING;
  72                 tf->command = ATA_CMD_IDLEIMMEDIATE;
  73                 tf->feature = 0x44;
  74                 tf->lbal = 0x4c;
  75                 tf->lbam = 0x4e;
  76                 tf->lbah = 0x55;
  77                 cmd.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE;
  78         } else          /* cmd == REQ_UNPARK_HEADS */
  79                 tf->command = ATA_CMD_CHK_POWER;
  80
  81         cmd.tf_flags |= IDE_TFLAG_CUSTOM_HANDLER;
  82         cmd.protocol = ATA_PROT_NODATA;
  83
  84         cmd.rq = rq;
  85
  86         return do_rw_taskfile(drive, &cmd);
  87 }
  88
  89 ssize_t ide_park_show(struct device *dev, struct device_attribute *attr,
  90                       char *buf)
  91 {
  92         ide_drive_t *drive = to_ide_device(dev);
  93         ide_hwif_t *hwif = drive->hwif;
  94         unsigned long now;
  95         unsigned int msecs;
  96
  97         if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
  98                 return -EOPNOTSUPP;
  99
 100         spin_lock_irq(&hwif->lock);
 101         now = jiffies;
 102         if (drive->dev_flags & IDE_DFLAG_PARKED &&
 103             time_after(drive->sleep, now))
 104                 msecs = jiffies_to_msecs(drive->sleep - now);
 105         else
 106                 msecs = 0;
 107         spin_unlock_irq(&hwif->lock);
 108
 109         return snprintf(buf, 20, "%u\n", msecs);
 110 }
 111
 112 ssize_t ide_park_store(struct device *dev, struct device_attribute *attr,
 113                        const char *buf, size_t len)
 114 {
 115 #define MAX_PARK_TIMEOUT 30000
 116         ide_drive_t *drive = to_ide_device(dev);
 117         long int input;
 118         int rc;
 119
 120         rc = strict_strtol(buf, 10, &input);
 121         if (rc || input < -2)
 122                 return -EINVAL;
 123         if (input > MAX_PARK_TIMEOUT) {
 124                 input = MAX_PARK_TIMEOUT;
 125                 rc = -EOVERFLOW;
 126         }
 127
 128         mutex_lock(&ide_setting_mtx);
 129         if (input >= 0) {
 130                 if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
 131                         rc = -EOPNOTSUPP;
 132                 else if (input || drive->dev_flags & IDE_DFLAG_PARKED)
 133                         issue_park_cmd(drive, msecs_to_jiffies(input));
 134         } else {
 135                 if (drive->media == ide_disk)
 136                         switch (input) {
 137                         case -1:
 138                                 drive->dev_flags &= ~IDE_DFLAG_NO_UNLOAD;
 139                                 break;
 140                         case -2:
 141                                 drive->dev_flags |= IDE_DFLAG_NO_UNLOAD;
 142                                 break;
 143                         }
 144                 else
 145                         rc = -EOPNOTSUPP;
 146         }
 147         mutex_unlock(&ide_setting_mtx);
 148
 149         return rc ? rc : len;
 150 }