1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *	scsi_pm.c	Copyright (C) 2010 Alan Stern
4  *
5  *	SCSI dynamic Power Management
6  *		Initial version: Alan Stern <stern@rowland.harvard.edu>
7  */
8 
9 #include <linux/pm_runtime.h>
10 #include <linux/export.h>
11 #include <linux/blk-pm.h>
12 
13 #include <scsi/scsi.h>
14 #include <scsi/scsi_device.h>
15 #include <scsi/scsi_driver.h>
16 #include <scsi/scsi_host.h>
17 
18 #include "scsi_priv.h"
19 
20 #ifdef CONFIG_PM_SLEEP
21 
do_scsi_suspend(struct device * dev,const struct dev_pm_ops * pm)22 static int do_scsi_suspend(struct device *dev, const struct dev_pm_ops *pm)
23 {
24 	return pm && pm->suspend ? pm->suspend(dev) : 0;
25 }
26 
do_scsi_freeze(struct device * dev,const struct dev_pm_ops * pm)27 static int do_scsi_freeze(struct device *dev, const struct dev_pm_ops *pm)
28 {
29 	return pm && pm->freeze ? pm->freeze(dev) : 0;
30 }
31 
do_scsi_poweroff(struct device * dev,const struct dev_pm_ops * pm)32 static int do_scsi_poweroff(struct device *dev, const struct dev_pm_ops *pm)
33 {
34 	return pm && pm->poweroff ? pm->poweroff(dev) : 0;
35 }
36 
do_scsi_resume(struct device * dev,const struct dev_pm_ops * pm)37 static int do_scsi_resume(struct device *dev, const struct dev_pm_ops *pm)
38 {
39 	return pm && pm->resume ? pm->resume(dev) : 0;
40 }
41 
do_scsi_thaw(struct device * dev,const struct dev_pm_ops * pm)42 static int do_scsi_thaw(struct device *dev, const struct dev_pm_ops *pm)
43 {
44 	return pm && pm->thaw ? pm->thaw(dev) : 0;
45 }
46 
do_scsi_restore(struct device * dev,const struct dev_pm_ops * pm)47 static int do_scsi_restore(struct device *dev, const struct dev_pm_ops *pm)
48 {
49 	return pm && pm->restore ? pm->restore(dev) : 0;
50 }
51 
scsi_dev_type_suspend(struct device * dev,int (* cb)(struct device *,const struct dev_pm_ops *))52 static int scsi_dev_type_suspend(struct device *dev,
53 		int (*cb)(struct device *, const struct dev_pm_ops *))
54 {
55 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
56 	int err;
57 
58 	err = scsi_device_quiesce(to_scsi_device(dev));
59 	if (err == 0) {
60 		err = cb(dev, pm);
61 		if (err)
62 			scsi_device_resume(to_scsi_device(dev));
63 	}
64 	dev_dbg(dev, "scsi suspend: %d\n", err);
65 	return err;
66 }
67 
68 static int
scsi_bus_suspend_common(struct device * dev,int (* cb)(struct device *,const struct dev_pm_ops *))69 scsi_bus_suspend_common(struct device *dev,
70 		int (*cb)(struct device *, const struct dev_pm_ops *))
71 {
72 	if (!scsi_is_sdev_device(dev))
73 		return 0;
74 
75 	return scsi_dev_type_suspend(dev, cb);
76 }
77 
scsi_bus_resume_common(struct device * dev,int (* cb)(struct device *,const struct dev_pm_ops *))78 static int scsi_bus_resume_common(struct device *dev,
79 		int (*cb)(struct device *, const struct dev_pm_ops *))
80 {
81 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
82 	int err;
83 
84 	if (!scsi_is_sdev_device(dev))
85 		return 0;
86 
87 	err = cb(dev, pm);
88 	scsi_device_resume(to_scsi_device(dev));
89 	dev_dbg(dev, "scsi resume: %d\n", err);
90 
91 	return err;
92 }
93 
scsi_bus_prepare(struct device * dev)94 static int scsi_bus_prepare(struct device *dev)
95 {
96 	if (scsi_is_host_device(dev)) {
97 		/* Wait until async scanning is finished */
98 		scsi_complete_async_scans();
99 	}
100 	return 0;
101 }
102 
scsi_bus_suspend(struct device * dev)103 static int scsi_bus_suspend(struct device *dev)
104 {
105 	return scsi_bus_suspend_common(dev, do_scsi_suspend);
106 }
107 
scsi_bus_resume(struct device * dev)108 static int scsi_bus_resume(struct device *dev)
109 {
110 	return scsi_bus_resume_common(dev, do_scsi_resume);
111 }
112 
scsi_bus_freeze(struct device * dev)113 static int scsi_bus_freeze(struct device *dev)
114 {
115 	return scsi_bus_suspend_common(dev, do_scsi_freeze);
116 }
117 
scsi_bus_thaw(struct device * dev)118 static int scsi_bus_thaw(struct device *dev)
119 {
120 	return scsi_bus_resume_common(dev, do_scsi_thaw);
121 }
122 
scsi_bus_poweroff(struct device * dev)123 static int scsi_bus_poweroff(struct device *dev)
124 {
125 	return scsi_bus_suspend_common(dev, do_scsi_poweroff);
126 }
127 
scsi_bus_restore(struct device * dev)128 static int scsi_bus_restore(struct device *dev)
129 {
130 	return scsi_bus_resume_common(dev, do_scsi_restore);
131 }
132 
133 #else /* CONFIG_PM_SLEEP */
134 
135 #define scsi_bus_prepare		NULL
136 #define scsi_bus_suspend		NULL
137 #define scsi_bus_resume			NULL
138 #define scsi_bus_freeze			NULL
139 #define scsi_bus_thaw			NULL
140 #define scsi_bus_poweroff		NULL
141 #define scsi_bus_restore		NULL
142 
143 #endif /* CONFIG_PM_SLEEP */
144 
sdev_runtime_suspend(struct device * dev)145 static int sdev_runtime_suspend(struct device *dev)
146 {
147 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
148 	struct scsi_device *sdev = to_scsi_device(dev);
149 	int err = 0;
150 
151 	err = blk_pre_runtime_suspend(sdev->request_queue);
152 	if (err)
153 		return err;
154 	if (pm && pm->runtime_suspend)
155 		err = pm->runtime_suspend(dev);
156 	blk_post_runtime_suspend(sdev->request_queue, err);
157 
158 	return err;
159 }
160 
scsi_runtime_suspend(struct device * dev)161 static int scsi_runtime_suspend(struct device *dev)
162 {
163 	int err = 0;
164 
165 	dev_dbg(dev, "scsi_runtime_suspend\n");
166 	if (scsi_is_sdev_device(dev))
167 		err = sdev_runtime_suspend(dev);
168 
169 	/* Insert hooks here for targets, hosts, and transport classes */
170 
171 	return err;
172 }
173 
sdev_runtime_resume(struct device * dev)174 static int sdev_runtime_resume(struct device *dev)
175 {
176 	struct scsi_device *sdev = to_scsi_device(dev);
177 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
178 	int err = 0;
179 
180 	blk_pre_runtime_resume(sdev->request_queue);
181 	if (pm && pm->runtime_resume)
182 		err = pm->runtime_resume(dev);
183 	blk_post_runtime_resume(sdev->request_queue);
184 
185 	return err;
186 }
187 
scsi_runtime_resume(struct device * dev)188 static int scsi_runtime_resume(struct device *dev)
189 {
190 	int err = 0;
191 
192 	dev_dbg(dev, "scsi_runtime_resume\n");
193 	if (scsi_is_sdev_device(dev))
194 		err = sdev_runtime_resume(dev);
195 
196 	/* Insert hooks here for targets, hosts, and transport classes */
197 
198 	return err;
199 }
200 
scsi_runtime_idle(struct device * dev)201 static int scsi_runtime_idle(struct device *dev)
202 {
203 	dev_dbg(dev, "scsi_runtime_idle\n");
204 
205 	/* Insert hooks here for targets, hosts, and transport classes */
206 
207 	if (scsi_is_sdev_device(dev)) {
208 		pm_runtime_mark_last_busy(dev);
209 		pm_runtime_autosuspend(dev);
210 		return -EBUSY;
211 	}
212 
213 	return 0;
214 }
215 
scsi_autopm_get_device(struct scsi_device * sdev)216 int scsi_autopm_get_device(struct scsi_device *sdev)
217 {
218 	int	err;
219 
220 	err = pm_runtime_get_sync(&sdev->sdev_gendev);
221 	if (err < 0 && err !=-EACCES)
222 		pm_runtime_put_sync(&sdev->sdev_gendev);
223 	else
224 		err = 0;
225 	return err;
226 }
227 EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
228 
scsi_autopm_put_device(struct scsi_device * sdev)229 void scsi_autopm_put_device(struct scsi_device *sdev)
230 {
231 	pm_runtime_put_sync(&sdev->sdev_gendev);
232 }
233 EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
234 
scsi_autopm_get_target(struct scsi_target * starget)235 void scsi_autopm_get_target(struct scsi_target *starget)
236 {
237 	pm_runtime_get_sync(&starget->dev);
238 }
239 
scsi_autopm_put_target(struct scsi_target * starget)240 void scsi_autopm_put_target(struct scsi_target *starget)
241 {
242 	pm_runtime_put_sync(&starget->dev);
243 }
244 
scsi_autopm_get_host(struct Scsi_Host * shost)245 int scsi_autopm_get_host(struct Scsi_Host *shost)
246 {
247 	int	err;
248 
249 	err = pm_runtime_get_sync(&shost->shost_gendev);
250 	if (err < 0 && err !=-EACCES)
251 		pm_runtime_put_sync(&shost->shost_gendev);
252 	else
253 		err = 0;
254 	return err;
255 }
256 
scsi_autopm_put_host(struct Scsi_Host * shost)257 void scsi_autopm_put_host(struct Scsi_Host *shost)
258 {
259 	pm_runtime_put_sync(&shost->shost_gendev);
260 }
261 
262 const struct dev_pm_ops scsi_bus_pm_ops = {
263 	.prepare =		scsi_bus_prepare,
264 	.suspend =		scsi_bus_suspend,
265 	.resume =		scsi_bus_resume,
266 	.freeze =		scsi_bus_freeze,
267 	.thaw =			scsi_bus_thaw,
268 	.poweroff =		scsi_bus_poweroff,
269 	.restore =		scsi_bus_restore,
270 	.runtime_suspend =	scsi_runtime_suspend,
271 	.runtime_resume =	scsi_runtime_resume,
272 	.runtime_idle =		scsi_runtime_idle,
273 };
274