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/async.h>
12 #include <linux/blk-pm.h>
13
14 #include <scsi/scsi.h>
15 #include <scsi/scsi_device.h>
16 #include <scsi/scsi_driver.h>
17 #include <scsi/scsi_host.h>
18
19 #include "scsi_priv.h"
20
21 #ifdef CONFIG_PM_SLEEP
22
do_scsi_suspend(struct device * dev,const struct dev_pm_ops * pm)23 static int do_scsi_suspend(struct device *dev, const struct dev_pm_ops *pm)
24 {
25 return pm && pm->suspend ? pm->suspend(dev) : 0;
26 }
27
do_scsi_freeze(struct device * dev,const struct dev_pm_ops * pm)28 static int do_scsi_freeze(struct device *dev, const struct dev_pm_ops *pm)
29 {
30 return pm && pm->freeze ? pm->freeze(dev) : 0;
31 }
32
do_scsi_poweroff(struct device * dev,const struct dev_pm_ops * pm)33 static int do_scsi_poweroff(struct device *dev, const struct dev_pm_ops *pm)
34 {
35 return pm && pm->poweroff ? pm->poweroff(dev) : 0;
36 }
37
do_scsi_resume(struct device * dev,const struct dev_pm_ops * pm)38 static int do_scsi_resume(struct device *dev, const struct dev_pm_ops *pm)
39 {
40 return pm && pm->resume ? pm->resume(dev) : 0;
41 }
42
do_scsi_thaw(struct device * dev,const struct dev_pm_ops * pm)43 static int do_scsi_thaw(struct device *dev, const struct dev_pm_ops *pm)
44 {
45 return pm && pm->thaw ? pm->thaw(dev) : 0;
46 }
47
do_scsi_restore(struct device * dev,const struct dev_pm_ops * pm)48 static int do_scsi_restore(struct device *dev, const struct dev_pm_ops *pm)
49 {
50 return pm && pm->restore ? pm->restore(dev) : 0;
51 }
52
scsi_dev_type_suspend(struct device * dev,int (* cb)(struct device *,const struct dev_pm_ops *))53 static int scsi_dev_type_suspend(struct device *dev,
54 int (*cb)(struct device *, const struct dev_pm_ops *))
55 {
56 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
57 int err;
58
59 /* flush pending in-flight resume operations, suspend is synchronous */
60 async_synchronize_full_domain(&scsi_sd_pm_domain);
61
62 err = scsi_device_quiesce(to_scsi_device(dev));
63 if (err == 0) {
64 err = cb(dev, pm);
65 if (err)
66 scsi_device_resume(to_scsi_device(dev));
67 }
68 dev_dbg(dev, "scsi suspend: %d\n", err);
69 return err;
70 }
71
scsi_dev_type_resume(struct device * dev,int (* cb)(struct device *,const struct dev_pm_ops *))72 static int scsi_dev_type_resume(struct device *dev,
73 int (*cb)(struct device *, const struct dev_pm_ops *))
74 {
75 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
76 int err = 0;
77
78 err = cb(dev, pm);
79 scsi_device_resume(to_scsi_device(dev));
80 dev_dbg(dev, "scsi resume: %d\n", err);
81
82 if (err == 0) {
83 pm_runtime_disable(dev);
84 err = pm_runtime_set_active(dev);
85 pm_runtime_enable(dev);
86
87 /*
88 * Forcibly set runtime PM status of request queue to "active"
89 * to make sure we can again get requests from the queue
90 * (see also blk_pm_peek_request()).
91 *
92 * The resume hook will correct runtime PM status of the disk.
93 */
94 if (!err && scsi_is_sdev_device(dev)) {
95 struct scsi_device *sdev = to_scsi_device(dev);
96
97 blk_set_runtime_active(sdev->request_queue);
98 }
99 }
100
101 return err;
102 }
103
104 static int
scsi_bus_suspend_common(struct device * dev,int (* cb)(struct device *,const struct dev_pm_ops *))105 scsi_bus_suspend_common(struct device *dev,
106 int (*cb)(struct device *, const struct dev_pm_ops *))
107 {
108 int err = 0;
109
110 if (scsi_is_sdev_device(dev)) {
111 /*
112 * All the high-level SCSI drivers that implement runtime
113 * PM treat runtime suspend, system suspend, and system
114 * hibernate nearly identically. In all cases the requirements
115 * for runtime suspension are stricter.
116 */
117 if (pm_runtime_suspended(dev))
118 return 0;
119
120 err = scsi_dev_type_suspend(dev, cb);
121 }
122
123 return err;
124 }
125
async_sdev_resume(void * dev,async_cookie_t cookie)126 static void async_sdev_resume(void *dev, async_cookie_t cookie)
127 {
128 scsi_dev_type_resume(dev, do_scsi_resume);
129 }
130
async_sdev_thaw(void * dev,async_cookie_t cookie)131 static void async_sdev_thaw(void *dev, async_cookie_t cookie)
132 {
133 scsi_dev_type_resume(dev, do_scsi_thaw);
134 }
135
async_sdev_restore(void * dev,async_cookie_t cookie)136 static void async_sdev_restore(void *dev, async_cookie_t cookie)
137 {
138 scsi_dev_type_resume(dev, do_scsi_restore);
139 }
140
scsi_bus_resume_common(struct device * dev,int (* cb)(struct device *,const struct dev_pm_ops *))141 static int scsi_bus_resume_common(struct device *dev,
142 int (*cb)(struct device *, const struct dev_pm_ops *))
143 {
144 async_func_t fn;
145
146 if (!scsi_is_sdev_device(dev))
147 fn = NULL;
148 else if (cb == do_scsi_resume)
149 fn = async_sdev_resume;
150 else if (cb == do_scsi_thaw)
151 fn = async_sdev_thaw;
152 else if (cb == do_scsi_restore)
153 fn = async_sdev_restore;
154 else
155 fn = NULL;
156
157 if (fn) {
158 async_schedule_domain(fn, dev, &scsi_sd_pm_domain);
159
160 /*
161 * If a user has disabled async probing a likely reason
162 * is due to a storage enclosure that does not inject
163 * staggered spin-ups. For safety, make resume
164 * synchronous as well in that case.
165 */
166 if (strncmp(scsi_scan_type, "async", 5) != 0)
167 async_synchronize_full_domain(&scsi_sd_pm_domain);
168 } else {
169 pm_runtime_disable(dev);
170 pm_runtime_set_active(dev);
171 pm_runtime_enable(dev);
172 }
173 return 0;
174 }
175
scsi_bus_prepare(struct device * dev)176 static int scsi_bus_prepare(struct device *dev)
177 {
178 if (scsi_is_host_device(dev)) {
179 /* Wait until async scanning is finished */
180 scsi_complete_async_scans();
181 }
182 return 0;
183 }
184
scsi_bus_suspend(struct device * dev)185 static int scsi_bus_suspend(struct device *dev)
186 {
187 return scsi_bus_suspend_common(dev, do_scsi_suspend);
188 }
189
scsi_bus_resume(struct device * dev)190 static int scsi_bus_resume(struct device *dev)
191 {
192 return scsi_bus_resume_common(dev, do_scsi_resume);
193 }
194
scsi_bus_freeze(struct device * dev)195 static int scsi_bus_freeze(struct device *dev)
196 {
197 return scsi_bus_suspend_common(dev, do_scsi_freeze);
198 }
199
scsi_bus_thaw(struct device * dev)200 static int scsi_bus_thaw(struct device *dev)
201 {
202 return scsi_bus_resume_common(dev, do_scsi_thaw);
203 }
204
scsi_bus_poweroff(struct device * dev)205 static int scsi_bus_poweroff(struct device *dev)
206 {
207 return scsi_bus_suspend_common(dev, do_scsi_poweroff);
208 }
209
scsi_bus_restore(struct device * dev)210 static int scsi_bus_restore(struct device *dev)
211 {
212 return scsi_bus_resume_common(dev, do_scsi_restore);
213 }
214
215 #else /* CONFIG_PM_SLEEP */
216
217 #define scsi_bus_prepare NULL
218 #define scsi_bus_suspend NULL
219 #define scsi_bus_resume NULL
220 #define scsi_bus_freeze NULL
221 #define scsi_bus_thaw NULL
222 #define scsi_bus_poweroff NULL
223 #define scsi_bus_restore NULL
224
225 #endif /* CONFIG_PM_SLEEP */
226
sdev_runtime_suspend(struct device * dev)227 static int sdev_runtime_suspend(struct device *dev)
228 {
229 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
230 struct scsi_device *sdev = to_scsi_device(dev);
231 int err = 0;
232
233 err = blk_pre_runtime_suspend(sdev->request_queue);
234 if (err)
235 return err;
236 if (pm && pm->runtime_suspend)
237 err = pm->runtime_suspend(dev);
238 blk_post_runtime_suspend(sdev->request_queue, err);
239
240 return err;
241 }
242
scsi_runtime_suspend(struct device * dev)243 static int scsi_runtime_suspend(struct device *dev)
244 {
245 int err = 0;
246
247 dev_dbg(dev, "scsi_runtime_suspend\n");
248 if (scsi_is_sdev_device(dev))
249 err = sdev_runtime_suspend(dev);
250
251 /* Insert hooks here for targets, hosts, and transport classes */
252
253 return err;
254 }
255
sdev_runtime_resume(struct device * dev)256 static int sdev_runtime_resume(struct device *dev)
257 {
258 struct scsi_device *sdev = to_scsi_device(dev);
259 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
260 int err = 0;
261
262 blk_pre_runtime_resume(sdev->request_queue);
263 if (pm && pm->runtime_resume)
264 err = pm->runtime_resume(dev);
265 blk_post_runtime_resume(sdev->request_queue);
266
267 return err;
268 }
269
scsi_runtime_resume(struct device * dev)270 static int scsi_runtime_resume(struct device *dev)
271 {
272 int err = 0;
273
274 dev_dbg(dev, "scsi_runtime_resume\n");
275 if (scsi_is_sdev_device(dev))
276 err = sdev_runtime_resume(dev);
277
278 /* Insert hooks here for targets, hosts, and transport classes */
279
280 return err;
281 }
282
scsi_runtime_idle(struct device * dev)283 static int scsi_runtime_idle(struct device *dev)
284 {
285 dev_dbg(dev, "scsi_runtime_idle\n");
286
287 /* Insert hooks here for targets, hosts, and transport classes */
288
289 if (scsi_is_sdev_device(dev)) {
290 pm_runtime_mark_last_busy(dev);
291 pm_runtime_autosuspend(dev);
292 return -EBUSY;
293 }
294
295 return 0;
296 }
297
scsi_autopm_get_device(struct scsi_device * sdev)298 int scsi_autopm_get_device(struct scsi_device *sdev)
299 {
300 int err;
301
302 err = pm_runtime_get_sync(&sdev->sdev_gendev);
303 if (err < 0 && err !=-EACCES)
304 pm_runtime_put_sync(&sdev->sdev_gendev);
305 else
306 err = 0;
307 return err;
308 }
309 EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
310
scsi_autopm_put_device(struct scsi_device * sdev)311 void scsi_autopm_put_device(struct scsi_device *sdev)
312 {
313 pm_runtime_put_sync(&sdev->sdev_gendev);
314 }
315 EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
316
scsi_autopm_get_target(struct scsi_target * starget)317 void scsi_autopm_get_target(struct scsi_target *starget)
318 {
319 pm_runtime_get_sync(&starget->dev);
320 }
321
scsi_autopm_put_target(struct scsi_target * starget)322 void scsi_autopm_put_target(struct scsi_target *starget)
323 {
324 pm_runtime_put_sync(&starget->dev);
325 }
326
scsi_autopm_get_host(struct Scsi_Host * shost)327 int scsi_autopm_get_host(struct Scsi_Host *shost)
328 {
329 int err;
330
331 err = pm_runtime_get_sync(&shost->shost_gendev);
332 if (err < 0 && err !=-EACCES)
333 pm_runtime_put_sync(&shost->shost_gendev);
334 else
335 err = 0;
336 return err;
337 }
338
scsi_autopm_put_host(struct Scsi_Host * shost)339 void scsi_autopm_put_host(struct Scsi_Host *shost)
340 {
341 pm_runtime_put_sync(&shost->shost_gendev);
342 }
343
344 const struct dev_pm_ops scsi_bus_pm_ops = {
345 .prepare = scsi_bus_prepare,
346 .suspend = scsi_bus_suspend,
347 .resume = scsi_bus_resume,
348 .freeze = scsi_bus_freeze,
349 .thaw = scsi_bus_thaw,
350 .poweroff = scsi_bus_poweroff,
351 .restore = scsi_bus_restore,
352 .runtime_suspend = scsi_runtime_suspend,
353 .runtime_resume = scsi_runtime_resume,
354 .runtime_idle = scsi_runtime_idle,
355 };
356