drivers/scsi/scsi_pm.c

   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
  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
  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
  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
  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
  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
  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
  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
  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                         if (sdev->request_queue->dev)
  98                                 blk_set_runtime_active(sdev->request_queue);
  99                 }
 100         }
 101
 102         return err;
 103 }
 104
 105 static int
 106 scsi_bus_suspend_common(struct device *dev,
 107                 int (*cb)(struct device *, const struct dev_pm_ops *))
 108 {
 109         int err = 0;
 110
 111         if (scsi_is_sdev_device(dev)) {
 112                 /*
 113                  * All the high-level SCSI drivers that implement runtime
 114                  * PM treat runtime suspend, system suspend, and system
 115                  * hibernate nearly identically. In all cases the requirements
 116                  * for runtime suspension are stricter.
 117                  */
 118                 if (pm_runtime_suspended(dev))
 119                         return 0;
 120
 121                 err = scsi_dev_type_suspend(dev, cb);
 122         }
 123
 124         return err;
 125 }
 126
 127 static void async_sdev_resume(void *dev, async_cookie_t cookie)
 128 {
 129         scsi_dev_type_resume(dev, do_scsi_resume);
 130 }
 131
 132 static void async_sdev_thaw(void *dev, async_cookie_t cookie)
 133 {
 134         scsi_dev_type_resume(dev, do_scsi_thaw);
 135 }
 136
 137 static void async_sdev_restore(void *dev, async_cookie_t cookie)
 138 {
 139         scsi_dev_type_resume(dev, do_scsi_restore);
 140 }
 141
 142 static int scsi_bus_resume_common(struct device *dev,
 143                 int (*cb)(struct device *, const struct dev_pm_ops *))
 144 {
 145         async_func_t fn;
 146
 147         if (!scsi_is_sdev_device(dev))
 148                 fn = NULL;
 149         else if (cb == do_scsi_resume)
 150                 fn = async_sdev_resume;
 151         else if (cb == do_scsi_thaw)
 152                 fn = async_sdev_thaw;
 153         else if (cb == do_scsi_restore)
 154                 fn = async_sdev_restore;
 155         else
 156                 fn = NULL;
 157
 158         if (fn) {
 159                 async_schedule_domain(fn, dev, &scsi_sd_pm_domain);
 160
 161                 /*
 162                  * If a user has disabled async probing a likely reason
 163                  * is due to a storage enclosure that does not inject
 164                  * staggered spin-ups.  For safety, make resume
 165                  * synchronous as well in that case.
 166                  */
 167                 if (strncmp(scsi_scan_type, "async", 5) != 0)
 168                         async_synchronize_full_domain(&scsi_sd_pm_domain);
 169         } else {
 170                 pm_runtime_disable(dev);
 171                 pm_runtime_set_active(dev);
 172                 pm_runtime_enable(dev);
 173         }
 174         return 0;
 175 }
 176
 177 static int scsi_bus_prepare(struct device *dev)
 178 {
 179         if (scsi_is_host_device(dev)) {
 180                 /* Wait until async scanning is finished */
 181                 scsi_complete_async_scans();
 182         }
 183         return 0;
 184 }
 185
 186 static int scsi_bus_suspend(struct device *dev)
 187 {
 188         return scsi_bus_suspend_common(dev, do_scsi_suspend);
 189 }
 190
 191 static int scsi_bus_resume(struct device *dev)
 192 {
 193         return scsi_bus_resume_common(dev, do_scsi_resume);
 194 }
 195
 196 static int scsi_bus_freeze(struct device *dev)
 197 {
 198         return scsi_bus_suspend_common(dev, do_scsi_freeze);
 199 }
 200
 201 static int scsi_bus_thaw(struct device *dev)
 202 {
 203         return scsi_bus_resume_common(dev, do_scsi_thaw);
 204 }
 205
 206 static int scsi_bus_poweroff(struct device *dev)
 207 {
 208         return scsi_bus_suspend_common(dev, do_scsi_poweroff);
 209 }
 210
 211 static int scsi_bus_restore(struct device *dev)
 212 {
 213         return scsi_bus_resume_common(dev, do_scsi_restore);
 214 }
 215
 216 #else /* CONFIG_PM_SLEEP */
 217
 218 #define scsi_bus_prepare                NULL
 219 #define scsi_bus_suspend                NULL
 220 #define scsi_bus_resume                 NULL
 221 #define scsi_bus_freeze                 NULL
 222 #define scsi_bus_thaw                   NULL
 223 #define scsi_bus_poweroff               NULL
 224 #define scsi_bus_restore                NULL
 225
 226 #endif /* CONFIG_PM_SLEEP */
 227
 228 static int sdev_runtime_suspend(struct device *dev)
 229 {
 230         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 231         struct scsi_device *sdev = to_scsi_device(dev);
 232         int err = 0;
 233
 234         err = blk_pre_runtime_suspend(sdev->request_queue);
 235         if (err)
 236                 return err;
 237         if (pm && pm->runtime_suspend)
 238                 err = pm->runtime_suspend(dev);
 239         blk_post_runtime_suspend(sdev->request_queue, err);
 240
 241         return err;
 242 }
 243
 244 static int scsi_runtime_suspend(struct device *dev)
 245 {
 246         int err = 0;
 247
 248         dev_dbg(dev, "scsi_runtime_suspend\n");
 249         if (scsi_is_sdev_device(dev))
 250                 err = sdev_runtime_suspend(dev);
 251
 252         /* Insert hooks here for targets, hosts, and transport classes */
 253
 254         return err;
 255 }
 256
 257 static int sdev_runtime_resume(struct device *dev)
 258 {
 259         struct scsi_device *sdev = to_scsi_device(dev);
 260         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 261         int err = 0;
 262
 263         blk_pre_runtime_resume(sdev->request_queue);
 264         if (pm && pm->runtime_resume)
 265                 err = pm->runtime_resume(dev);
 266         blk_post_runtime_resume(sdev->request_queue, err);
 267
 268         return err;
 269 }
 270
 271 static int scsi_runtime_resume(struct device *dev)
 272 {
 273         int err = 0;
 274
 275         dev_dbg(dev, "scsi_runtime_resume\n");
 276         if (scsi_is_sdev_device(dev))
 277                 err = sdev_runtime_resume(dev);
 278
 279         /* Insert hooks here for targets, hosts, and transport classes */
 280
 281         return err;
 282 }
 283
 284 static int scsi_runtime_idle(struct device *dev)
 285 {
 286         dev_dbg(dev, "scsi_runtime_idle\n");
 287
 288         /* Insert hooks here for targets, hosts, and transport classes */
 289
 290         if (scsi_is_sdev_device(dev)) {
 291                 pm_runtime_mark_last_busy(dev);
 292                 pm_runtime_autosuspend(dev);
 293                 return -EBUSY;
 294         }
 295
 296         return 0;
 297 }
 298
 299 int scsi_autopm_get_device(struct scsi_device *sdev)
 300 {
 301         int     err;
 302
 303         err = pm_runtime_get_sync(&sdev->sdev_gendev);
 304         if (err < 0 && err !=-EACCES)
 305                 pm_runtime_put_sync(&sdev->sdev_gendev);
 306         else
 307                 err = 0;
 308         return err;
 309 }
 310 EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
 311
 312 void scsi_autopm_put_device(struct scsi_device *sdev)
 313 {
 314         pm_runtime_put_sync(&sdev->sdev_gendev);
 315 }
 316 EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
 317
 318 void scsi_autopm_get_target(struct scsi_target *starget)
 319 {
 320         pm_runtime_get_sync(&starget->dev);
 321 }
 322
 323 void scsi_autopm_put_target(struct scsi_target *starget)
 324 {
 325         pm_runtime_put_sync(&starget->dev);
 326 }
 327
 328 int scsi_autopm_get_host(struct Scsi_Host *shost)
 329 {
 330         int     err;
 331
 332         err = pm_runtime_get_sync(&shost->shost_gendev);
 333         if (err < 0 && err !=-EACCES)
 334                 pm_runtime_put_sync(&shost->shost_gendev);
 335         else
 336                 err = 0;
 337         return err;
 338 }
 339
 340 void scsi_autopm_put_host(struct Scsi_Host *shost)
 341 {
 342         pm_runtime_put_sync(&shost->shost_gendev);
 343 }
 344
 345 const struct dev_pm_ops scsi_bus_pm_ops = {
 346         .prepare =              scsi_bus_prepare,
 347         .suspend =              scsi_bus_suspend,
 348         .resume =               scsi_bus_resume,
 349         .freeze =               scsi_bus_freeze,
 350         .thaw =                 scsi_bus_thaw,
 351         .poweroff =             scsi_bus_poweroff,
 352         .restore =              scsi_bus_restore,
 353         .runtime_suspend =      scsi_runtime_suspend,
 354         .runtime_resume =       scsi_runtime_resume,
 355         .runtime_idle =         scsi_runtime_idle,
 356 };