tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 spin_lock_irq(q->queue_lock);
29 blk_start_queueing(q);
30 spin_unlock_irq(q->queue_lock);
31 }
32 return;
33 }
34 spin_unlock_irq(&hwif->lock);
35
36 rq = blk_get_request(q, READ, __GFP_WAIT);
37 rq->cmd[0] = REQ_PARK_HEADS;
38 rq->cmd_len = 1;
39 rq->cmd_type = REQ_TYPE_SPECIAL;
40 rq->special = &timeout;
41 rc = blk_execute_rq(q, NULL, rq, 1);
42 blk_put_request(rq);
43 if (rc)
44 goto out;
45
46 /*
47 * Make sure that *some* command is sent to the drive after the
48 * timeout has expired, so power management will be reenabled.
49 */
50 rq = blk_get_request(q, READ, GFP_NOWAIT);
51 if (unlikely(!rq))
52 goto out;
53
54 rq->cmd[0] = REQ_UNPARK_HEADS;
55 rq->cmd_len = 1;
56 rq->cmd_type = REQ_TYPE_SPECIAL;
57 elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 1);
58
59out:
60 return;
61}
62
63ssize_t ide_park_show(struct device *dev, struct device_attribute *attr,
64 char *buf)
65{
66 ide_drive_t *drive = to_ide_device(dev);
67 ide_hwif_t *hwif = drive->hwif;
68 unsigned long now;
69 unsigned int msecs;
70
71 if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
72 return -EOPNOTSUPP;
73
74 spin_lock_irq(&hwif->lock);
75 now = jiffies;
76 if (drive->dev_flags & IDE_DFLAG_PARKED &&
77 time_after(drive->sleep, now))
78 msecs = jiffies_to_msecs(drive->sleep - now);
79 else
80 msecs = 0;
81 spin_unlock_irq(&hwif->lock);
82
83 return snprintf(buf, 20, "%u\n", msecs);
84}
85
86ssize_t ide_park_store(struct device *dev, struct device_attribute *attr,
87 const char *buf, size_t len)
88{
89#define MAX_PARK_TIMEOUT 30000
90 ide_drive_t *drive = to_ide_device(dev);
91 long int input;
92 int rc;
93
94 rc = strict_strtol(buf, 10, &input);
95 if (rc || input < -2)
96 return -EINVAL;
97 if (input > MAX_PARK_TIMEOUT) {
98 input = MAX_PARK_TIMEOUT;
99 rc = -EOVERFLOW;
100 }
101
102 mutex_lock(&ide_setting_mtx);
103 if (input >= 0) {
104 if (drive->dev_flags & IDE_DFLAG_NO_UNLOAD)
105 rc = -EOPNOTSUPP;
106 else if (input || drive->dev_flags & IDE_DFLAG_PARKED)
107 issue_park_cmd(drive, msecs_to_jiffies(input));
108 } else {
109 if (drive->media == ide_disk)
110 switch (input) {
111 case -1:
112 drive->dev_flags &= ~IDE_DFLAG_NO_UNLOAD;
113 break;
114 case -2:
115 drive->dev_flags |= IDE_DFLAG_NO_UNLOAD;
116 break;
117 }
118 else
119 rc = -EOPNOTSUPP;
120 }
121 mutex_unlock(&ide_setting_mtx);
122
123 return rc ? rc : len;
124}