summaryrefslogtreecommitdiffstats
path: root/drivers/scsi/scsi_pm.c
blob: d4201ded3b2203c0bd9cc17d8a26b528f5ccfc2c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
/*
 *	scsi_pm.c	Copyright (C) 2010 Alan Stern
 *
 *	SCSI dynamic Power Management
 *		Initial version: Alan Stern <stern@rowland.harvard.edu>
 */

#include <linux/pm_runtime.h>
#include <linux/export.h>
#include <linux/async.h>

#include <scsi/scsi.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_host.h>

#include "scsi_priv.h"

static int scsi_dev_type_suspend(struct device *dev, pm_message_t msg)
{
	struct device_driver *drv;
	int err;

	err = scsi_device_quiesce(to_scsi_device(dev));
	if (err == 0) {
		drv = dev->driver;
		if (drv && drv->suspend) {
			err = drv->suspend(dev, msg);
			if (err)
				scsi_device_resume(to_scsi_device(dev));
		}
	}
	dev_dbg(dev, "scsi suspend: %d\n", err);
	return err;
}

static int scsi_dev_type_resume(struct device *dev)
{
	struct device_driver *drv;
	int err = 0;

	drv = dev->driver;
	if (drv && drv->resume)
		err = drv->resume(dev);
	scsi_device_resume(to_scsi_device(dev));
	dev_dbg(dev, "scsi resume: %d\n", err);
	return err;
}

#ifdef CONFIG_PM_SLEEP

static int scsi_bus_suspend_common(struct device *dev, pm_message_t msg)
{
	int err = 0;

	if (scsi_is_sdev_device(dev)) {
		/*
		 * sd is the only high-level SCSI driver to implement runtime
		 * PM, and sd treats runtime suspend, system suspend, and
		 * system hibernate identically (but not system freeze).
		 */
		if (pm_runtime_suspended(dev)) {
			if (msg.event == PM_EVENT_SUSPEND ||
			    msg.event == PM_EVENT_HIBERNATE)
				return 0;	/* already suspended */

			/* wake up device so that FREEZE will succeed */
			pm_runtime_resume(dev);
		}
		err = scsi_dev_type_suspend(dev, msg);
	}
	return err;
}

static int scsi_bus_resume_common(struct device *dev)
{
	int err = 0;

	if (scsi_is_sdev_device(dev)) {
		/*
		 * Parent device may have runtime suspended as soon as
		 * it is woken up during the system resume.
		 *
		 * Resume it on behalf of child.
		 */
		pm_runtime_get_sync(dev->parent);
		err = scsi_dev_type_resume(dev);
		pm_runtime_put_sync(dev->parent);
	}

	if (err == 0) {
		pm_runtime_disable(dev);
		pm_runtime_set_active(dev);
		pm_runtime_enable(dev);
	}
	return err;
}

static int scsi_bus_prepare(struct device *dev)
{
	if (scsi_is_sdev_device(dev)) {
		/* sd probing uses async_schedule.  Wait until it finishes. */
		async_synchronize_full_domain(&scsi_sd_probe_domain);

	} else if (scsi_is_host_device(dev)) {
		/* Wait until async scanning is finished */
		scsi_complete_async_scans();
	}
	return 0;
}

static int scsi_bus_suspend(struct device *dev)
{
	return scsi_bus_suspend_common(dev, PMSG_SUSPEND);
}

static int scsi_bus_freeze(struct device *dev)
{
	return scsi_bus_suspend_common(dev, PMSG_FREEZE);
}

static int scsi_bus_poweroff(struct device *dev)
{
	return scsi_bus_suspend_common(dev, PMSG_HIBERNATE);
}

#else /* CONFIG_PM_SLEEP */

#define scsi_bus_resume_common		NULL
#define scsi_bus_prepare		NULL
#define scsi_bus_suspend		NULL
#define scsi_bus_freeze			NULL
#define scsi_bus_poweroff		NULL

#endif /* CONFIG_PM_SLEEP */

#ifdef CONFIG_PM_RUNTIME

static int scsi_runtime_suspend(struct device *dev)
{
	int err = 0;

	dev_dbg(dev, "scsi_runtime_suspend\n");
	if (scsi_is_sdev_device(dev)) {
		err = scsi_dev_type_suspend(dev, PMSG_AUTO_SUSPEND);
		if (err == -EAGAIN)
			pm_schedule_suspend(dev, jiffies_to_msecs(
				round_jiffies_up_relative(HZ/10)));
	}

	/* Insert hooks here for targets, hosts, and transport classes */

	return err;
}

static int scsi_runtime_resume(struct device *dev)
{
	int err = 0;

	dev_dbg(dev, "scsi_runtime_resume\n");
	if (scsi_is_sdev_device(dev))
		err = scsi_dev_type_resume(dev);

	/* Insert hooks here for targets, hosts, and transport classes */

	return err;
}

static int scsi_runtime_idle(struct device *dev)
{
	int err;

	dev_dbg(dev, "scsi_runtime_idle\n");

	/* Insert hooks here for targets, hosts, and transport classes */

	if (scsi_is_sdev_device(dev))
		err = pm_schedule_suspend(dev, 100);
	else
		err = pm_runtime_suspend(dev);
	return err;
}

int scsi_autopm_get_device(struct scsi_device *sdev)
{
	int	err;

	err = pm_runtime_get_sync(&sdev->sdev_gendev);
	if (err < 0 && err !=-EACCES)
		pm_runtime_put_sync(&sdev->sdev_gendev);
	else
		err = 0;
	return err;
}
EXPORT_SYMBOL_GPL(scsi_autopm_get_device);

void scsi_autopm_put_device(struct scsi_device *sdev)
{
	pm_runtime_put_sync(&sdev->sdev_gendev);
}
EXPORT_SYMBOL_GPL(scsi_autopm_put_device);

void scsi_autopm_get_target(struct scsi_target *starget)
{
	pm_runtime_get_sync(&starget->dev);
}

void scsi_autopm_put_target(struct scsi_target *starget)
{
	pm_runtime_put_sync(&starget->dev);
}

int scsi_autopm_get_host(struct Scsi_Host *shost)
{
	int	err;

	err = pm_runtime_get_sync(&shost->shost_gendev);
	if (err < 0 && err !=-EACCES)
		pm_runtime_put_sync(&shost->shost_gendev);
	else
		err = 0;
	return err;
}

void scsi_autopm_put_host(struct Scsi_Host *shost)
{
	pm_runtime_put_sync(&shost->shost_gendev);
}

#else

#define scsi_runtime_suspend	NULL
#define scsi_runtime_resume	NULL
#define scsi_runtime_idle	NULL

#endif /* CONFIG_PM_RUNTIME */

const struct dev_pm_ops scsi_bus_pm_ops = {
	.prepare =		scsi_bus_prepare,
	.suspend =		scsi_bus_suspend,
	.resume =		scsi_bus_resume_common,
	.freeze =		scsi_bus_freeze,
	.thaw =			scsi_bus_resume_common,
	.poweroff =		scsi_bus_poweroff,
	.restore =		scsi_bus_resume_common,
	.runtime_suspend =	scsi_runtime_suspend,
	.runtime_resume =	scsi_runtime_resume,
	.runtime_idle =		scsi_runtime_idle,
};