ide-park.c revision 7eaceaccab5f40bbfda044629a6298616aeaed50 
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