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                         blk_set_runtime_active(sdev->request_queue);
  98                 }
  99         }
 100
 101         return err;
 102 }
 103
 104 static int
 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
 126 static void async_sdev_resume(void *dev, async_cookie_t cookie)
 127 {
 128         scsi_dev_type_resume(dev, do_scsi_resume);
 129 }
 130
 131 static void async_sdev_thaw(void *dev, async_cookie_t cookie)
 132 {
 133         scsi_dev_type_resume(dev, do_scsi_thaw);
 134 }
 135
 136 static void async_sdev_restore(void *dev, async_cookie_t cookie)
 137 {
 138         scsi_dev_type_resume(dev, do_scsi_restore);
 139 }
 140
 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
 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
 185 static int scsi_bus_suspend(struct device *dev)
 186 {
 187         return scsi_bus_suspend_common(dev, do_scsi_suspend);
 188 }
 189
 190 static int scsi_bus_resume(struct device *dev)
 191 {
 192         return scsi_bus_resume_common(dev, do_scsi_resume);
 193 }
 194
 195 static int scsi_bus_freeze(struct device *dev)
 196 {
 197         return scsi_bus_suspend_common(dev, do_scsi_freeze);
 198 }
 199
 200 static int scsi_bus_thaw(struct device *dev)
 201 {
 202         return scsi_bus_resume_common(dev, do_scsi_thaw);
 203 }
 204
 205 static int scsi_bus_poweroff(struct device *dev)
 206 {
 207         return scsi_bus_suspend_common(dev, do_scsi_poweroff);
 208 }
 209
 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
 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
 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
 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, err);
 266
 267         return err;
 268 }
 269
 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
 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
 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
 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
 317 void scsi_autopm_get_target(struct scsi_target *starget)
 318 {
 319         pm_runtime_get_sync(&starget->dev);
 320 }
 321
 322 void scsi_autopm_put_target(struct scsi_target *starget)
 323 {
 324         pm_runtime_put_sync(&starget->dev);
 325 }
 326
 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
 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 };