drivers/scsi/scsi_pm.c

   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
  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
  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
  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
  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
  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
  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
  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
  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                 err = pm_runtime_set_active(dev);
  83                 pm_runtime_enable(dev);
  84
  85                 /*
  86                  * Forcibly set runtime PM status of request queue to "active"
  87                  * to make sure we can again get requests from the queue
  88                  * (see also blk_pm_peek_request()).
  89                  *
  90                  * The resume hook will correct runtime PM status of the disk.
  91                  */
  92                 if (!err && scsi_is_sdev_device(dev)) {
  93                         struct scsi_device *sdev = to_scsi_device(dev);
  94
  95                         if (sdev->request_queue->dev)
  96                                 blk_set_runtime_active(sdev->request_queue);
  97                 }
  98         }
  99
 100         return err;
 101 }
 102
 103 static int
 104 scsi_bus_suspend_common(struct device *dev,
 105                 int (*cb)(struct device *, const struct dev_pm_ops *))
 106 {
 107         int err = 0;
 108
 109         if (scsi_is_sdev_device(dev)) {
 110                 /*
 111                  * All the high-level SCSI drivers that implement runtime
 112                  * PM treat runtime suspend, system suspend, and system
 113                  * hibernate nearly identically. In all cases the requirements
 114                  * for runtime suspension are stricter.
 115                  */
 116                 if (pm_runtime_suspended(dev))
 117                         return 0;
 118
 119                 err = scsi_dev_type_suspend(dev, cb);
 120         }
 121
 122         return err;
 123 }
 124
 125 static void async_sdev_resume(void *dev, async_cookie_t cookie)
 126 {
 127         scsi_dev_type_resume(dev, do_scsi_resume);
 128 }
 129
 130 static void async_sdev_thaw(void *dev, async_cookie_t cookie)
 131 {
 132         scsi_dev_type_resume(dev, do_scsi_thaw);
 133 }
 134
 135 static void async_sdev_restore(void *dev, async_cookie_t cookie)
 136 {
 137         scsi_dev_type_resume(dev, do_scsi_restore);
 138 }
 139
 140 static int scsi_bus_resume_common(struct device *dev,
 141                 int (*cb)(struct device *, const struct dev_pm_ops *))
 142 {
 143         async_func_t fn;
 144
 145         if (!scsi_is_sdev_device(dev))
 146                 fn = NULL;
 147         else if (cb == do_scsi_resume)
 148                 fn = async_sdev_resume;
 149         else if (cb == do_scsi_thaw)
 150                 fn = async_sdev_thaw;
 151         else if (cb == do_scsi_restore)
 152                 fn = async_sdev_restore;
 153         else
 154                 fn = NULL;
 155
 156         if (fn) {
 157                 async_schedule_domain(fn, dev, &scsi_sd_pm_domain);
 158
 159                 /*
 160                  * If a user has disabled async probing a likely reason
 161                  * is due to a storage enclosure that does not inject
 162                  * staggered spin-ups.  For safety, make resume
 163                  * synchronous as well in that case.
 164                  */
 165                 if (strncmp(scsi_scan_type, "async", 5) != 0)
 166                         async_synchronize_full_domain(&scsi_sd_pm_domain);
 167         } else {
 168                 pm_runtime_disable(dev);
 169                 pm_runtime_set_active(dev);
 170                 pm_runtime_enable(dev);
 171         }
 172         return 0;
 173 }
 174
 175 static int scsi_bus_prepare(struct device *dev)
 176 {
 177         if (scsi_is_sdev_device(dev)) {
 178                 /* sd probing uses async_schedule.  Wait until it finishes. */
 179                 async_synchronize_full_domain(&scsi_sd_probe_domain);
 180
 181         } else if (scsi_is_host_device(dev)) {
 182                 /* Wait until async scanning is finished */
 183                 scsi_complete_async_scans();
 184         }
 185         return 0;
 186 }
 187
 188 static int scsi_bus_suspend(struct device *dev)
 189 {
 190         return scsi_bus_suspend_common(dev, do_scsi_suspend);
 191 }
 192
 193 static int scsi_bus_resume(struct device *dev)
 194 {
 195         return scsi_bus_resume_common(dev, do_scsi_resume);
 196 }
 197
 198 static int scsi_bus_freeze(struct device *dev)
 199 {
 200         return scsi_bus_suspend_common(dev, do_scsi_freeze);
 201 }
 202
 203 static int scsi_bus_thaw(struct device *dev)
 204 {
 205         return scsi_bus_resume_common(dev, do_scsi_thaw);
 206 }
 207
 208 static int scsi_bus_poweroff(struct device *dev)
 209 {
 210         return scsi_bus_suspend_common(dev, do_scsi_poweroff);
 211 }
 212
 213 static int scsi_bus_restore(struct device *dev)
 214 {
 215         return scsi_bus_resume_common(dev, do_scsi_restore);
 216 }
 217
 218 #else /* CONFIG_PM_SLEEP */
 219
 220 #define scsi_bus_prepare                NULL
 221 #define scsi_bus_suspend                NULL
 222 #define scsi_bus_resume                 NULL
 223 #define scsi_bus_freeze                 NULL
 224 #define scsi_bus_thaw                   NULL
 225 #define scsi_bus_poweroff               NULL
 226 #define scsi_bus_restore                NULL
 227
 228 #endif /* CONFIG_PM_SLEEP */
 229
 230 static int sdev_runtime_suspend(struct device *dev)
 231 {
 232         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 233         struct scsi_device *sdev = to_scsi_device(dev);
 234         int err = 0;
 235
 236         err = blk_pre_runtime_suspend(sdev->request_queue);
 237         if (err)
 238                 return err;
 239         if (pm && pm->runtime_suspend)
 240                 err = pm->runtime_suspend(dev);
 241         blk_post_runtime_suspend(sdev->request_queue, err);
 242
 243         return err;
 244 }
 245
 246 static int scsi_runtime_suspend(struct device *dev)
 247 {
 248         int err = 0;
 249
 250         dev_dbg(dev, "scsi_runtime_suspend\n");
 251         if (scsi_is_sdev_device(dev))
 252                 err = sdev_runtime_suspend(dev);
 253
 254         /* Insert hooks here for targets, hosts, and transport classes */
 255
 256         return err;
 257 }
 258
 259 static int sdev_runtime_resume(struct device *dev)
 260 {
 261         struct scsi_device *sdev = to_scsi_device(dev);
 262         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 263         int err = 0;
 264
 265         blk_pre_runtime_resume(sdev->request_queue);
 266         if (pm && pm->runtime_resume)
 267                 err = pm->runtime_resume(dev);
 268         blk_post_runtime_resume(sdev->request_queue, err);
 269
 270         return err;
 271 }
 272
 273 static int scsi_runtime_resume(struct device *dev)
 274 {
 275         int err = 0;
 276
 277         dev_dbg(dev, "scsi_runtime_resume\n");
 278         if (scsi_is_sdev_device(dev))
 279                 err = sdev_runtime_resume(dev);
 280
 281         /* Insert hooks here for targets, hosts, and transport classes */
 282
 283         return err;
 284 }
 285
 286 static int scsi_runtime_idle(struct device *dev)
 287 {
 288         dev_dbg(dev, "scsi_runtime_idle\n");
 289
 290         /* Insert hooks here for targets, hosts, and transport classes */
 291
 292         if (scsi_is_sdev_device(dev)) {
 293                 pm_runtime_mark_last_busy(dev);
 294                 pm_runtime_autosuspend(dev);
 295                 return -EBUSY;
 296         }
 297
 298         return 0;
 299 }
 300
 301 int scsi_autopm_get_device(struct scsi_device *sdev)
 302 {
 303         int     err;
 304
 305         err = pm_runtime_get_sync(&sdev->sdev_gendev);
 306         if (err < 0 && err !=-EACCES)
 307                 pm_runtime_put_sync(&sdev->sdev_gendev);
 308         else
 309                 err = 0;
 310         return err;
 311 }
 312 EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
 313
 314 void scsi_autopm_put_device(struct scsi_device *sdev)
 315 {
 316         pm_runtime_put_sync(&sdev->sdev_gendev);
 317 }
 318 EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
 319
 320 void scsi_autopm_get_target(struct scsi_target *starget)
 321 {
 322         pm_runtime_get_sync(&starget->dev);
 323 }
 324
 325 void scsi_autopm_put_target(struct scsi_target *starget)
 326 {
 327         pm_runtime_put_sync(&starget->dev);
 328 }
 329
 330 int scsi_autopm_get_host(struct Scsi_Host *shost)
 331 {
 332         int     err;
 333
 334         err = pm_runtime_get_sync(&shost->shost_gendev);
 335         if (err < 0 && err !=-EACCES)
 336                 pm_runtime_put_sync(&shost->shost_gendev);
 337         else
 338                 err = 0;
 339         return err;
 340 }
 341
 342 void scsi_autopm_put_host(struct Scsi_Host *shost)
 343 {
 344         pm_runtime_put_sync(&shost->shost_gendev);
 345 }
 346
 347 const struct dev_pm_ops scsi_bus_pm_ops = {
 348         .prepare =              scsi_bus_prepare,
 349         .suspend =              scsi_bus_suspend,
 350         .resume =               scsi_bus_resume,
 351         .freeze =               scsi_bus_freeze,
 352         .thaw =                 scsi_bus_thaw,
 353         .poweroff =             scsi_bus_poweroff,
 354         .restore =              scsi_bus_restore,
 355         .runtime_suspend =      scsi_runtime_suspend,
 356         .runtime_resume =       scsi_runtime_resume,
 357         .runtime_idle =         scsi_runtime_idle,
 358 };