1 /*
2 * scsi_pm.c Copyright (C) 2010 Alan Stern
3 *
4 * SCSI dynamic Power Management
5 * Initial version: Alan Stern <stern@rowland.harvard.edu>
6 */
7
8 #include <linux/pm_runtime.h>
9 #include <linux/export.h>
10 #include <linux/async.h>
11
12 #include <scsi/scsi.h>
13 #include <scsi/scsi_device.h>
14 #include <scsi/scsi_driver.h>
15 #include <scsi/scsi_host.h>
16
17 #include "scsi_priv.h"
18
19 #ifdef CONFIG_PM_SLEEP
20
do_scsi_suspend(struct device * dev,const struct dev_pm_ops * pm)21 static int do_scsi_suspend(struct device *dev, const struct dev_pm_ops *pm)
22 {
23 return pm && pm->suspend ? pm->suspend(dev) : 0;
24 }
25
do_scsi_freeze(struct device * dev,const struct dev_pm_ops * pm)26 static int do_scsi_freeze(struct device *dev, const struct dev_pm_ops *pm)
27 {
28 return pm && pm->freeze ? pm->freeze(dev) : 0;
29 }
30
do_scsi_poweroff(struct device * dev,const struct dev_pm_ops * pm)31 static int do_scsi_poweroff(struct device *dev, const struct dev_pm_ops *pm)
32 {
33 return pm && pm->poweroff ? pm->poweroff(dev) : 0;
34 }
35
do_scsi_resume(struct device * dev,const struct dev_pm_ops * pm)36 static int do_scsi_resume(struct device *dev, const struct dev_pm_ops *pm)
37 {
38 return pm && pm->resume ? pm->resume(dev) : 0;
39 }
40
do_scsi_thaw(struct device * dev,const struct dev_pm_ops * pm)41 static int do_scsi_thaw(struct device *dev, const struct dev_pm_ops *pm)
42 {
43 return pm && pm->thaw ? pm->thaw(dev) : 0;
44 }
45
do_scsi_restore(struct device * dev,const struct dev_pm_ops * pm)46 static int do_scsi_restore(struct device *dev, const struct dev_pm_ops *pm)
47 {
48 return pm && pm->restore ? pm->restore(dev) : 0;
49 }
50
scsi_dev_type_suspend(struct device * dev,int (* cb)(struct device *,const struct dev_pm_ops *))51 static int scsi_dev_type_suspend(struct device *dev,
52 int (*cb)(struct device *, const struct dev_pm_ops *))
53 {
54 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
55 int err;
56
57 /* flush pending in-flight resume operations, suspend is synchronous */
58 async_synchronize_full_domain(&scsi_sd_pm_domain);
59
60 err = scsi_device_quiesce(to_scsi_device(dev));
61 if (err == 0) {
62 err = cb(dev, pm);
63 if (err)
64 scsi_device_resume(to_scsi_device(dev));
65 }
66 dev_dbg(dev, "scsi suspend: %d\n", err);
67 return err;
68 }
69
scsi_dev_type_resume(struct device * dev,int (* cb)(struct device *,const struct dev_pm_ops *))70 static int scsi_dev_type_resume(struct device *dev,
71 int (*cb)(struct device *, const struct dev_pm_ops *))
72 {
73 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
74 int err = 0;
75
76 err = cb(dev, pm);
77 scsi_device_resume(to_scsi_device(dev));
78 dev_dbg(dev, "scsi resume: %d\n", err);
79
80 if (err == 0) {
81 pm_runtime_disable(dev);
82 pm_runtime_set_active(dev);
83 pm_runtime_enable(dev);
84 }
85
86 return err;
87 }
88
89 static int
scsi_bus_suspend_common(struct device * dev,int (* cb)(struct device *,const struct dev_pm_ops *))90 scsi_bus_suspend_common(struct device *dev,
91 int (*cb)(struct device *, const struct dev_pm_ops *))
92 {
93 int err = 0;
94
95 if (scsi_is_sdev_device(dev)) {
96 /*
97 * All the high-level SCSI drivers that implement runtime
98 * PM treat runtime suspend, system suspend, and system
99 * hibernate nearly identically. In all cases the requirements
100 * for runtime suspension are stricter.
101 */
102 if (pm_runtime_suspended(dev))
103 return 0;
104
105 err = scsi_dev_type_suspend(dev, cb);
106 }
107
108 return err;
109 }
110
async_sdev_resume(void * dev,async_cookie_t cookie)111 static void async_sdev_resume(void *dev, async_cookie_t cookie)
112 {
113 scsi_dev_type_resume(dev, do_scsi_resume);
114 }
115
async_sdev_thaw(void * dev,async_cookie_t cookie)116 static void async_sdev_thaw(void *dev, async_cookie_t cookie)
117 {
118 scsi_dev_type_resume(dev, do_scsi_thaw);
119 }
120
async_sdev_restore(void * dev,async_cookie_t cookie)121 static void async_sdev_restore(void *dev, async_cookie_t cookie)
122 {
123 scsi_dev_type_resume(dev, do_scsi_restore);
124 }
125
scsi_bus_resume_common(struct device * dev,int (* cb)(struct device *,const struct dev_pm_ops *))126 static int scsi_bus_resume_common(struct device *dev,
127 int (*cb)(struct device *, const struct dev_pm_ops *))
128 {
129 async_func_t fn;
130
131 if (!scsi_is_sdev_device(dev))
132 fn = NULL;
133 else if (cb == do_scsi_resume)
134 fn = async_sdev_resume;
135 else if (cb == do_scsi_thaw)
136 fn = async_sdev_thaw;
137 else if (cb == do_scsi_restore)
138 fn = async_sdev_restore;
139 else
140 fn = NULL;
141
142 if (fn) {
143 async_schedule_domain(fn, dev, &scsi_sd_pm_domain);
144
145 /*
146 * If a user has disabled async probing a likely reason
147 * is due to a storage enclosure that does not inject
148 * staggered spin-ups. For safety, make resume
149 * synchronous as well in that case.
150 */
151 if (strncmp(scsi_scan_type, "async", 5) != 0)
152 async_synchronize_full_domain(&scsi_sd_pm_domain);
153 } else {
154 pm_runtime_disable(dev);
155 pm_runtime_set_active(dev);
156 pm_runtime_enable(dev);
157 }
158 return 0;
159 }
160
scsi_bus_prepare(struct device * dev)161 static int scsi_bus_prepare(struct device *dev)
162 {
163 if (scsi_is_sdev_device(dev)) {
164 /* sd probing uses async_schedule. Wait until it finishes. */
165 async_synchronize_full_domain(&scsi_sd_probe_domain);
166
167 } else if (scsi_is_host_device(dev)) {
168 /* Wait until async scanning is finished */
169 scsi_complete_async_scans();
170 }
171 return 0;
172 }
173
scsi_bus_suspend(struct device * dev)174 static int scsi_bus_suspend(struct device *dev)
175 {
176 return scsi_bus_suspend_common(dev, do_scsi_suspend);
177 }
178
scsi_bus_resume(struct device * dev)179 static int scsi_bus_resume(struct device *dev)
180 {
181 return scsi_bus_resume_common(dev, do_scsi_resume);
182 }
183
scsi_bus_freeze(struct device * dev)184 static int scsi_bus_freeze(struct device *dev)
185 {
186 return scsi_bus_suspend_common(dev, do_scsi_freeze);
187 }
188
scsi_bus_thaw(struct device * dev)189 static int scsi_bus_thaw(struct device *dev)
190 {
191 return scsi_bus_resume_common(dev, do_scsi_thaw);
192 }
193
scsi_bus_poweroff(struct device * dev)194 static int scsi_bus_poweroff(struct device *dev)
195 {
196 return scsi_bus_suspend_common(dev, do_scsi_poweroff);
197 }
198
scsi_bus_restore(struct device * dev)199 static int scsi_bus_restore(struct device *dev)
200 {
201 return scsi_bus_resume_common(dev, do_scsi_restore);
202 }
203
204 #else /* CONFIG_PM_SLEEP */
205
206 #define scsi_bus_prepare NULL
207 #define scsi_bus_suspend NULL
208 #define scsi_bus_resume NULL
209 #define scsi_bus_freeze NULL
210 #define scsi_bus_thaw NULL
211 #define scsi_bus_poweroff NULL
212 #define scsi_bus_restore NULL
213
214 #endif /* CONFIG_PM_SLEEP */
215
216 #ifdef CONFIG_PM_RUNTIME
217
sdev_runtime_suspend(struct device * dev)218 static int sdev_runtime_suspend(struct device *dev)
219 {
220 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
221 struct scsi_device *sdev = to_scsi_device(dev);
222 int err = 0;
223
224 if (pm && pm->runtime_suspend) {
225 err = blk_pre_runtime_suspend(sdev->request_queue);
226 if (err)
227 return err;
228 err = pm->runtime_suspend(dev);
229 blk_post_runtime_suspend(sdev->request_queue, err);
230 }
231 return err;
232 }
233
scsi_runtime_suspend(struct device * dev)234 static int scsi_runtime_suspend(struct device *dev)
235 {
236 int err = 0;
237
238 dev_dbg(dev, "scsi_runtime_suspend\n");
239 if (scsi_is_sdev_device(dev))
240 err = sdev_runtime_suspend(dev);
241
242 /* Insert hooks here for targets, hosts, and transport classes */
243
244 return err;
245 }
246
sdev_runtime_resume(struct device * dev)247 static int sdev_runtime_resume(struct device *dev)
248 {
249 struct scsi_device *sdev = to_scsi_device(dev);
250 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
251 int err = 0;
252
253 if (pm && pm->runtime_resume) {
254 blk_pre_runtime_resume(sdev->request_queue);
255 err = pm->runtime_resume(dev);
256 blk_post_runtime_resume(sdev->request_queue, err);
257 }
258 return err;
259 }
260
scsi_runtime_resume(struct device * dev)261 static int scsi_runtime_resume(struct device *dev)
262 {
263 int err = 0;
264
265 dev_dbg(dev, "scsi_runtime_resume\n");
266 if (scsi_is_sdev_device(dev))
267 err = sdev_runtime_resume(dev);
268
269 /* Insert hooks here for targets, hosts, and transport classes */
270
271 return err;
272 }
273
scsi_runtime_idle(struct device * dev)274 static int scsi_runtime_idle(struct device *dev)
275 {
276 dev_dbg(dev, "scsi_runtime_idle\n");
277
278 /* Insert hooks here for targets, hosts, and transport classes */
279
280 if (scsi_is_sdev_device(dev)) {
281 pm_runtime_mark_last_busy(dev);
282 pm_runtime_autosuspend(dev);
283 return -EBUSY;
284 }
285
286 return 0;
287 }
288
scsi_autopm_get_device(struct scsi_device * sdev)289 int scsi_autopm_get_device(struct scsi_device *sdev)
290 {
291 int err;
292
293 err = pm_runtime_get_sync(&sdev->sdev_gendev);
294 if (err < 0 && err !=-EACCES)
295 pm_runtime_put_sync(&sdev->sdev_gendev);
296 else
297 err = 0;
298 return err;
299 }
300 EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
301
scsi_autopm_put_device(struct scsi_device * sdev)302 void scsi_autopm_put_device(struct scsi_device *sdev)
303 {
304 pm_runtime_put_sync(&sdev->sdev_gendev);
305 }
306 EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
307
scsi_autopm_get_target(struct scsi_target * starget)308 void scsi_autopm_get_target(struct scsi_target *starget)
309 {
310 pm_runtime_get_sync(&starget->dev);
311 }
312
scsi_autopm_put_target(struct scsi_target * starget)313 void scsi_autopm_put_target(struct scsi_target *starget)
314 {
315 pm_runtime_put_sync(&starget->dev);
316 }
317
scsi_autopm_get_host(struct Scsi_Host * shost)318 int scsi_autopm_get_host(struct Scsi_Host *shost)
319 {
320 int err;
321
322 err = pm_runtime_get_sync(&shost->shost_gendev);
323 if (err < 0 && err !=-EACCES)
324 pm_runtime_put_sync(&shost->shost_gendev);
325 else
326 err = 0;
327 return err;
328 }
329
scsi_autopm_put_host(struct Scsi_Host * shost)330 void scsi_autopm_put_host(struct Scsi_Host *shost)
331 {
332 pm_runtime_put_sync(&shost->shost_gendev);
333 }
334
335 #else
336
337 #define scsi_runtime_suspend NULL
338 #define scsi_runtime_resume NULL
339 #define scsi_runtime_idle NULL
340
341 #endif /* CONFIG_PM_RUNTIME */
342
343 const struct dev_pm_ops scsi_bus_pm_ops = {
344 .prepare = scsi_bus_prepare,
345 .suspend = scsi_bus_suspend,
346 .resume = scsi_bus_resume,
347 .freeze = scsi_bus_freeze,
348 .thaw = scsi_bus_thaw,
349 .poweroff = scsi_bus_poweroff,
350 .restore = scsi_bus_restore,
351 .runtime_suspend = scsi_runtime_suspend,
352 .runtime_resume = scsi_runtime_resume,
353 .runtime_idle = scsi_runtime_idle,
354 };
355