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                 pm_runtime_set_active(dev);
  84                 pm_runtime_enable(dev);
  85         }
  86
  87         return err;
  88 }
  89
  90 static int
  91 scsi_bus_suspend_common(struct device *dev,
  92                 int (*cb)(struct device *, const struct dev_pm_ops *))
  93 {
  94         int err = 0;
  95
  96         if (scsi_is_sdev_device(dev)) {
  97                 /*
  98                  * All the high-level SCSI drivers that implement runtime
  99                  * PM treat runtime suspend, system suspend, and system
 100                  * hibernate nearly identically. In all cases the requirements
 101                  * for runtime suspension are stricter.
 102                  */
 103                 if (pm_runtime_suspended(dev))
 104                         return 0;
 105
 106                 err = scsi_dev_type_suspend(dev, cb);
 107         }
 108
 109         return err;
 110 }
 111
 112 static void async_sdev_resume(void *dev, async_cookie_t cookie)
 113 {
 114         scsi_dev_type_resume(dev, do_scsi_resume);
 115 }
 116
 117 static void async_sdev_thaw(void *dev, async_cookie_t cookie)
 118 {
 119         scsi_dev_type_resume(dev, do_scsi_thaw);
 120 }
 121
 122 static void async_sdev_restore(void *dev, async_cookie_t cookie)
 123 {
 124         scsi_dev_type_resume(dev, do_scsi_restore);
 125 }
 126
 127 static int scsi_bus_resume_common(struct device *dev,
 128                 int (*cb)(struct device *, const struct dev_pm_ops *))
 129 {
 130         async_func_t fn;
 131
 132         if (!scsi_is_sdev_device(dev))
 133                 fn = NULL;
 134         else if (cb == do_scsi_resume)
 135                 fn = async_sdev_resume;
 136         else if (cb == do_scsi_thaw)
 137                 fn = async_sdev_thaw;
 138         else if (cb == do_scsi_restore)
 139                 fn = async_sdev_restore;
 140         else
 141                 fn = NULL;
 142
 143         /*
 144          * Forcibly set runtime PM status of request queue to "active" to
 145          * make sure we can again get requests from the queue (see also
 146          * blk_pm_peek_request()).
 147          *
 148          * The resume hook will correct runtime PM status of the disk.
 149          */
 150         if (scsi_is_sdev_device(dev) && pm_runtime_suspended(dev))
 151                 blk_set_runtime_active(to_scsi_device(dev)->request_queue);
 152
 153         if (fn) {
 154                 async_schedule_domain(fn, dev, &scsi_sd_pm_domain);
 155
 156                 /*
 157                  * If a user has disabled async probing a likely reason
 158                  * is due to a storage enclosure that does not inject
 159                  * staggered spin-ups.  For safety, make resume
 160                  * synchronous as well in that case.
 161                  */
 162                 if (strncmp(scsi_scan_type, "async", 5) != 0)
 163                         async_synchronize_full_domain(&scsi_sd_pm_domain);
 164         } else {
 165                 pm_runtime_disable(dev);
 166                 pm_runtime_set_active(dev);
 167                 pm_runtime_enable(dev);
 168         }
 169         return 0;
 170 }
 171
 172 static int scsi_bus_prepare(struct device *dev)
 173 {
 174         if (scsi_is_sdev_device(dev)) {
 175                 /* sd probing uses async_schedule.  Wait until it finishes. */
 176                 async_synchronize_full_domain(&scsi_sd_probe_domain);
 177
 178         } else 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 };