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