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