LXR linux/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
   6DECLARE_WAIT_QUEUE_HEAD(ide_park_wq);
   7
   8static 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
  56out:
  57        return;
  58}
  59
  60ide_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
  87ssize_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
 110ssize_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}
 149