linux/drivers/ide/ide-park.c
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   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
   7DECLARE_WAIT_QUEUE_HEAD(ide_park_wq);
   8
   9static 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);
  56
  57out:
  58        return;
  59}
  60
  61ide_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
  88ssize_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
 111ssize_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}
 150
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