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 
7 DECLARE_WAIT_QUEUE_HEAD(ide_park_wq);
8 
issue_park_cmd(ide_drive_t * drive,unsigned long timeout)9 static 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 
57 out:
58 	return;
59 }
60 
ide_do_park_unpark(ide_drive_t * drive,struct request * rq)61 ide_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 
ide_park_show(struct device * dev,struct device_attribute * attr,char * buf)88 ssize_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 
ide_park_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)111 ssize_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