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 scsi_dev_type_suspend(struct device *dev, int (*cb)(struct device *))
  22 {
  23         int err;
  24
  25         err = scsi_device_quiesce(to_scsi_device(dev));
  26         if (err == 0) {
  27                 if (cb) {
  28                         err = cb(dev);
  29                         if (err)
  30                                 scsi_device_resume(to_scsi_device(dev));
  31                 }
  32         }
  33         dev_dbg(dev, "scsi suspend: %d\n", err);
  34         return err;
  35 }
  36
  37 static int scsi_dev_type_resume(struct device *dev, int (*cb)(struct device *))
  38 {
  39         int err = 0;
  40
  41         if (cb)
  42                 err = cb(dev);
  43         scsi_device_resume(to_scsi_device(dev));
  44         dev_dbg(dev, "scsi resume: %d\n", err);
  45         return err;
  46 }
  47
  48 static int
  49 scsi_bus_suspend_common(struct device *dev, int (*cb)(struct device *))
  50 {
  51         int err = 0;
  52
  53         if (scsi_is_sdev_device(dev)) {
  54                 /*
  55                  * All the high-level SCSI drivers that implement runtime
  56                  * PM treat runtime suspend, system suspend, and system
  57                  * hibernate nearly identically. In all cases the requirements
  58                  * for runtime suspension are stricter.
  59                  */
  60                 if (pm_runtime_suspended(dev))
  61                         return 0;
  62
  63                 err = scsi_dev_type_suspend(dev, cb);
  64         }
  65
  66         return err;
  67 }
  68
  69 static int
  70 scsi_bus_resume_common(struct device *dev, int (*cb)(struct device *))
  71 {
  72         int err = 0;
  73
  74         if (scsi_is_sdev_device(dev))
  75                 err = scsi_dev_type_resume(dev, cb);
  76
  77         if (err == 0) {
  78                 pm_runtime_disable(dev);
  79                 pm_runtime_set_active(dev);
  80                 pm_runtime_enable(dev);
  81         }
  82         return err;
  83 }
  84
  85 static int scsi_bus_prepare(struct device *dev)
  86 {
  87         if (scsi_is_sdev_device(dev)) {
  88                 /* sd probing uses async_schedule.  Wait until it finishes. */
  89                 async_synchronize_full_domain(&scsi_sd_probe_domain);
  90
  91         } else if (scsi_is_host_device(dev)) {
  92                 /* Wait until async scanning is finished */
  93                 scsi_complete_async_scans();
  94         }
  95         return 0;
  96 }
  97
  98 static int scsi_bus_suspend(struct device *dev)
  99 {
 100         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 101         return scsi_bus_suspend_common(dev, pm ? pm->suspend : NULL);
 102 }
 103
 104 static int scsi_bus_resume(struct device *dev)
 105 {
 106         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 107         return scsi_bus_resume_common(dev, pm ? pm->resume : NULL);
 108 }
 109
 110 static int scsi_bus_freeze(struct device *dev)
 111 {
 112         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 113         return scsi_bus_suspend_common(dev, pm ? pm->freeze : NULL);
 114 }
 115
 116 static int scsi_bus_thaw(struct device *dev)
 117 {
 118         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 119         return scsi_bus_resume_common(dev, pm ? pm->thaw : NULL);
 120 }
 121
 122 static int scsi_bus_poweroff(struct device *dev)
 123 {
 124         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 125         return scsi_bus_suspend_common(dev, pm ? pm->poweroff : NULL);
 126 }
 127
 128 static int scsi_bus_restore(struct device *dev)
 129 {
 130         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 131         return scsi_bus_resume_common(dev, pm ? pm->restore : NULL);
 132 }
 133
 134 #else /* CONFIG_PM_SLEEP */
 135
 136 #define scsi_bus_prepare                NULL
 137 #define scsi_bus_suspend                NULL
 138 #define scsi_bus_resume                 NULL
 139 #define scsi_bus_freeze                 NULL
 140 #define scsi_bus_thaw                   NULL
 141 #define scsi_bus_poweroff               NULL
 142 #define scsi_bus_restore                NULL
 143
 144 #endif /* CONFIG_PM_SLEEP */
 145
 146 #ifdef CONFIG_PM_RUNTIME
 147
 148 static int sdev_runtime_suspend(struct device *dev)
 149 {
 150         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 151         struct scsi_device *sdev = to_scsi_device(dev);
 152         int err;
 153
 154         err = blk_pre_runtime_suspend(sdev->request_queue);
 155         if (err)
 156                 return err;
 157         if (pm && pm->runtime_suspend)
 158                 err = pm->runtime_suspend(dev);
 159         blk_post_runtime_suspend(sdev->request_queue, err);
 160
 161         return err;
 162 }
 163
 164 static int scsi_runtime_suspend(struct device *dev)
 165 {
 166         int err = 0;
 167
 168         dev_dbg(dev, "scsi_runtime_suspend\n");
 169         if (scsi_is_sdev_device(dev))
 170                 err = sdev_runtime_suspend(dev);
 171
 172         /* Insert hooks here for targets, hosts, and transport classes */
 173
 174         return err;
 175 }
 176
 177 static int sdev_runtime_resume(struct device *dev)
 178 {
 179         struct scsi_device *sdev = to_scsi_device(dev);
 180         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 181         int err = 0;
 182
 183         blk_pre_runtime_resume(sdev->request_queue);
 184         if (pm && pm->runtime_resume)
 185                 err = pm->runtime_resume(dev);
 186         blk_post_runtime_resume(sdev->request_queue, err);
 187
 188         return err;
 189 }
 190
 191 static int scsi_runtime_resume(struct device *dev)
 192 {
 193         int err = 0;
 194
 195         dev_dbg(dev, "scsi_runtime_resume\n");
 196         if (scsi_is_sdev_device(dev))
 197                 err = sdev_runtime_resume(dev);
 198
 199         /* Insert hooks here for targets, hosts, and transport classes */
 200
 201         return err;
 202 }
 203
 204 static int scsi_runtime_idle(struct device *dev)
 205 {
 206         dev_dbg(dev, "scsi_runtime_idle\n");
 207
 208         /* Insert hooks here for targets, hosts, and transport classes */
 209
 210         if (scsi_is_sdev_device(dev)) {
 211                 pm_runtime_mark_last_busy(dev);
 212                 pm_runtime_autosuspend(dev);
 213                 return -EBUSY;
 214         }
 215
 216         return 0;
 217 }
 218
 219 int scsi_autopm_get_device(struct scsi_device *sdev)
 220 {
 221         int     err;
 222
 223         err = pm_runtime_get_sync(&sdev->sdev_gendev);
 224         if (err < 0 && err !=-EACCES)
 225                 pm_runtime_put_sync(&sdev->sdev_gendev);
 226         else
 227                 err = 0;
 228         return err;
 229 }
 230 EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
 231
 232 void scsi_autopm_put_device(struct scsi_device *sdev)
 233 {
 234         pm_runtime_put_sync(&sdev->sdev_gendev);
 235 }
 236 EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
 237
 238 void scsi_autopm_get_target(struct scsi_target *starget)
 239 {
 240         pm_runtime_get_sync(&starget->dev);
 241 }
 242
 243 void scsi_autopm_put_target(struct scsi_target *starget)
 244 {
 245         pm_runtime_put_sync(&starget->dev);
 246 }
 247
 248 int scsi_autopm_get_host(struct Scsi_Host *shost)
 249 {
 250         int     err;
 251
 252         err = pm_runtime_get_sync(&shost->shost_gendev);
 253         if (err < 0 && err !=-EACCES)
 254                 pm_runtime_put_sync(&shost->shost_gendev);
 255         else
 256                 err = 0;
 257         return err;
 258 }
 259
 260 void scsi_autopm_put_host(struct Scsi_Host *shost)
 261 {
 262         pm_runtime_put_sync(&shost->shost_gendev);
 263 }
 264
 265 #else
 266
 267 #define scsi_runtime_suspend    NULL
 268 #define scsi_runtime_resume     NULL
 269 #define scsi_runtime_idle       NULL
 270
 271 #endif /* CONFIG_PM_RUNTIME */
 272
 273 const struct dev_pm_ops scsi_bus_pm_ops = {
 274         .prepare =              scsi_bus_prepare,
 275         .suspend =              scsi_bus_suspend,
 276         .resume =               scsi_bus_resume,
 277         .freeze =               scsi_bus_freeze,
 278         .thaw =                 scsi_bus_thaw,
 279         .poweroff =             scsi_bus_poweroff,
 280         .restore =              scsi_bus_restore,
 281         .runtime_suspend =      scsi_runtime_suspend,
 282         .runtime_resume =       scsi_runtime_resume,
 283         .runtime_idle =         scsi_runtime_idle,
 284 };