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 #include <linux/blk-pm.h>
  12
  13 #include <scsi/scsi.h>
  14 #include <scsi/scsi_device.h>
  15 #include <scsi/scsi_driver.h>
  16 #include <scsi/scsi_host.h>
  17
  18 #include "scsi_priv.h"
  19
  20 #ifdef CONFIG_PM_SLEEP
  21
  22 static int do_scsi_suspend(struct device *dev, const struct dev_pm_ops *pm)
  23 {
  24         return pm && pm->suspend ? pm->suspend(dev) : 0;
  25 }
  26
  27 static int do_scsi_freeze(struct device *dev, const struct dev_pm_ops *pm)
  28 {
  29         return pm && pm->freeze ? pm->freeze(dev) : 0;
  30 }
  31
  32 static int do_scsi_poweroff(struct device *dev, const struct dev_pm_ops *pm)
  33 {
  34         return pm && pm->poweroff ? pm->poweroff(dev) : 0;
  35 }
  36
  37 static int do_scsi_resume(struct device *dev, const struct dev_pm_ops *pm)
  38 {
  39         return pm && pm->resume ? pm->resume(dev) : 0;
  40 }
  41
  42 static int do_scsi_thaw(struct device *dev, const struct dev_pm_ops *pm)
  43 {
  44         return pm && pm->thaw ? pm->thaw(dev) : 0;
  45 }
  46
  47 static int do_scsi_restore(struct device *dev, const struct dev_pm_ops *pm)
  48 {
  49         return pm && pm->restore ? pm->restore(dev) : 0;
  50 }
  51
  52 static int scsi_dev_type_suspend(struct device *dev,
  53                 int (*cb)(struct device *, const struct dev_pm_ops *))
  54 {
  55         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
  56         int err;
  57
  58         /* flush pending in-flight resume operations, suspend is synchronous */
  59         async_synchronize_full_domain(&scsi_sd_pm_domain);
  60
  61         err = scsi_device_quiesce(to_scsi_device(dev));
  62         if (err == 0) {
  63                 err = cb(dev, pm);
  64                 if (err)
  65                         scsi_device_resume(to_scsi_device(dev));
  66         }
  67         dev_dbg(dev, "scsi suspend: %d\n", err);
  68         return err;
  69 }
  70
  71 static int scsi_dev_type_resume(struct device *dev,
  72                 int (*cb)(struct device *, const struct dev_pm_ops *))
  73 {
  74         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
  75         int err = 0;
  76
  77         err = cb(dev, pm);
  78         scsi_device_resume(to_scsi_device(dev));
  79         dev_dbg(dev, "scsi resume: %d\n", err);
  80
  81         if (err == 0) {
  82                 pm_runtime_disable(dev);
  83                 err = pm_runtime_set_active(dev);
  84                 pm_runtime_enable(dev);
  85
  86                 /*
  87                  * Forcibly set runtime PM status of request queue to "active"
  88                  * to make sure we can again get requests from the queue
  89                  * (see also blk_pm_peek_request()).
  90                  *
  91                  * The resume hook will correct runtime PM status of the disk.
  92                  */
  93                 if (!err && scsi_is_sdev_device(dev)) {
  94                         struct scsi_device *sdev = to_scsi_device(dev);
  95
  96                         if (sdev->request_queue->dev)
  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_sdev_device(dev)) {
 179                 /* sd probing uses async_schedule.  Wait until it finishes. */
 180                 async_synchronize_full_domain(&scsi_sd_probe_domain);
 181
 182         } else if (scsi_is_host_device(dev)) {
 183                 /* Wait until async scanning is finished */
 184                 scsi_complete_async_scans();
 185         }
 186         return 0;
 187 }
 188
 189 static int scsi_bus_suspend(struct device *dev)
 190 {
 191         return scsi_bus_suspend_common(dev, do_scsi_suspend);
 192 }
 193
 194 static int scsi_bus_resume(struct device *dev)
 195 {
 196         return scsi_bus_resume_common(dev, do_scsi_resume);
 197 }
 198
 199 static int scsi_bus_freeze(struct device *dev)
 200 {
 201         return scsi_bus_suspend_common(dev, do_scsi_freeze);
 202 }
 203
 204 static int scsi_bus_thaw(struct device *dev)
 205 {
 206         return scsi_bus_resume_common(dev, do_scsi_thaw);
 207 }
 208
 209 static int scsi_bus_poweroff(struct device *dev)
 210 {
 211         return scsi_bus_suspend_common(dev, do_scsi_poweroff);
 212 }
 213
 214 static int scsi_bus_restore(struct device *dev)
 215 {
 216         return scsi_bus_resume_common(dev, do_scsi_restore);
 217 }
 218
 219 #else /* CONFIG_PM_SLEEP */
 220
 221 #define scsi_bus_prepare                NULL
 222 #define scsi_bus_suspend                NULL
 223 #define scsi_bus_resume                 NULL
 224 #define scsi_bus_freeze                 NULL
 225 #define scsi_bus_thaw                   NULL
 226 #define scsi_bus_poweroff               NULL
 227 #define scsi_bus_restore                NULL
 228
 229 #endif /* CONFIG_PM_SLEEP */
 230
 231 static int sdev_runtime_suspend(struct device *dev)
 232 {
 233         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 234         struct scsi_device *sdev = to_scsi_device(dev);
 235         int err = 0;
 236
 237         err = blk_pre_runtime_suspend(sdev->request_queue);
 238         if (err)
 239                 return err;
 240         if (pm && pm->runtime_suspend)
 241                 err = pm->runtime_suspend(dev);
 242         blk_post_runtime_suspend(sdev->request_queue, err);
 243
 244         return err;
 245 }
 246
 247 static int scsi_runtime_suspend(struct device *dev)
 248 {
 249         int err = 0;
 250
 251         dev_dbg(dev, "scsi_runtime_suspend\n");
 252         if (scsi_is_sdev_device(dev))
 253                 err = sdev_runtime_suspend(dev);
 254
 255         /* Insert hooks here for targets, hosts, and transport classes */
 256
 257         return err;
 258 }
 259
 260 static int sdev_runtime_resume(struct device *dev)
 261 {
 262         struct scsi_device *sdev = to_scsi_device(dev);
 263         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 264         int err = 0;
 265
 266         blk_pre_runtime_resume(sdev->request_queue);
 267         if (pm && pm->runtime_resume)
 268                 err = pm->runtime_resume(dev);
 269         blk_post_runtime_resume(sdev->request_queue, err);
 270
 271         return err;
 272 }
 273
 274 static int scsi_runtime_resume(struct device *dev)
 275 {
 276         int err = 0;
 277
 278         dev_dbg(dev, "scsi_runtime_resume\n");
 279         if (scsi_is_sdev_device(dev))
 280                 err = sdev_runtime_resume(dev);
 281
 282         /* Insert hooks here for targets, hosts, and transport classes */
 283
 284         return err;
 285 }
 286
 287 static int scsi_runtime_idle(struct device *dev)
 288 {
 289         dev_dbg(dev, "scsi_runtime_idle\n");
 290
 291         /* Insert hooks here for targets, hosts, and transport classes */
 292
 293         if (scsi_is_sdev_device(dev)) {
 294                 pm_runtime_mark_last_busy(dev);
 295                 pm_runtime_autosuspend(dev);
 296                 return -EBUSY;
 297         }
 298
 299         return 0;
 300 }
 301
 302 int scsi_autopm_get_device(struct scsi_device *sdev)
 303 {
 304         int     err;
 305
 306         err = pm_runtime_get_sync(&sdev->sdev_gendev);
 307         if (err < 0 && err !=-EACCES)
 308                 pm_runtime_put_sync(&sdev->sdev_gendev);
 309         else
 310                 err = 0;
 311         return err;
 312 }
 313 EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
 314
 315 void scsi_autopm_put_device(struct scsi_device *sdev)
 316 {
 317         pm_runtime_put_sync(&sdev->sdev_gendev);
 318 }
 319 EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
 320
 321 void scsi_autopm_get_target(struct scsi_target *starget)
 322 {
 323         pm_runtime_get_sync(&starget->dev);
 324 }
 325
 326 void scsi_autopm_put_target(struct scsi_target *starget)
 327 {
 328         pm_runtime_put_sync(&starget->dev);
 329 }
 330
 331 int scsi_autopm_get_host(struct Scsi_Host *shost)
 332 {
 333         int     err;
 334
 335         err = pm_runtime_get_sync(&shost->shost_gendev);
 336         if (err < 0 && err !=-EACCES)
 337                 pm_runtime_put_sync(&shost->shost_gendev);
 338         else
 339                 err = 0;
 340         return err;
 341 }
 342
 343 void scsi_autopm_put_host(struct Scsi_Host *shost)
 344 {
 345         pm_runtime_put_sync(&shost->shost_gendev);
 346 }
 347
 348 const struct dev_pm_ops scsi_bus_pm_ops = {
 349         .prepare =              scsi_bus_prepare,
 350         .suspend =              scsi_bus_suspend,
 351         .resume =               scsi_bus_resume,
 352         .freeze =               scsi_bus_freeze,
 353         .thaw =                 scsi_bus_thaw,
 354         .poweroff =             scsi_bus_poweroff,
 355         .restore =              scsi_bus_restore,
 356         .runtime_suspend =      scsi_runtime_suspend,
 357         .runtime_resume =       scsi_runtime_resume,
 358         .runtime_idle =         scsi_runtime_idle,
 359 };