[PATCH] introduce fmode_t, do annotations
[linux-2.6] / 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         struct request_queue *q = drive->queue;
11         struct request *rq;
12         int rc;
13
14         timeout += jiffies;
15         spin_lock_irq(&ide_lock);
16         if (drive->dev_flags & IDE_DFLAG_PARKED) {
17                 ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;
18                 int reset_timer;
19
20                 reset_timer = time_before(timeout, drive->sleep);
21                 drive->sleep = timeout;
22                 wake_up_all(&ide_park_wq);
23                 if (reset_timer && hwgroup->sleeping &&
24                     del_timer(&hwgroup->timer)) {
25                         hwgroup->sleeping = 0;
26                         hwgroup->busy = 0;
27                         blk_start_queueing(q);
28                 }
29                 spin_unlock_irq(&ide_lock);
30                 return;
31         }
32         spin_unlock_irq(&ide_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 ssize_t ide_park_show(struct device *dev, struct device_attribute *attr,
62                       char *buf)
63 {
64         ide_drive_t *drive = to_ide_device(dev);
65         unsigned long now;
66         unsigned int msecs;
67
68         if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
69                 return -EOPNOTSUPP;
70
71         spin_lock_irq(&ide_lock);
72         now = jiffies;
73         if (drive->dev_flags & IDE_DFLAG_PARKED &&
74             time_after(drive->sleep, now))
75                 msecs = jiffies_to_msecs(drive->sleep - now);
76         else
77                 msecs = 0;
78         spin_unlock_irq(&ide_lock);
79
80         return snprintf(buf, 20, "%u\n", msecs);
81 }
82
83 ssize_t ide_park_store(struct device *dev, struct device_attribute *attr,
84                        const char *buf, size_t len)
85 {
86 #define MAX_PARK_TIMEOUT 30000
87         ide_drive_t *drive = to_ide_device(dev);
88         long int input;
89         int rc;
90
91         rc = strict_strtol(buf, 10, &input);
92         if (rc || input < -2)
93                 return -EINVAL;
94         if (input > MAX_PARK_TIMEOUT) {
95                 input = MAX_PARK_TIMEOUT;
96                 rc = -EOVERFLOW;
97         }
98
99         mutex_lock(&ide_setting_mtx);
100         if (input >= 0) {
101                 if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
102                         rc = -EOPNOTSUPP;
103                 else if (input || drive->dev_flags & IDE_DFLAG_PARKED)
104                         issue_park_cmd(drive, msecs_to_jiffies(input));
105         } else {
106                 if (drive->media == ide_disk)
107                         switch (input) {
108                         case -1:
109                                 drive->dev_flags &= ~IDE_DFLAG_NO_UNLOAD;
110                                 break;
111                         case -2:
112                                 drive->dev_flags |= IDE_DFLAG_NO_UNLOAD;
113                                 break;
114                         }
115                 else
116                         rc = -EOPNOTSUPP;
117         }
118         mutex_unlock(&ide_setting_mtx);
119
120         return rc ? rc : len;
121 }