drivers/ide/ide-park.c

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