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 static int scsi_dev_type_suspend(struct device *dev, int (*cb)(struct device *))
  20 {
  21         int err;
  22
  23         err = scsi_device_quiesce(to_scsi_device(dev));
  24         if (err == 0) {
  25                 if (cb) {
  26                         err = cb(dev);
  27                         if (err)
  28                                 scsi_device_resume(to_scsi_device(dev));
  29                 }
  30         }
  31         dev_dbg(dev, "scsi suspend: %d\n", err);
  32         return err;
  33 }
  34
  35 static int scsi_dev_type_resume(struct device *dev, int (*cb)(struct device *))
  36 {
  37         int err = 0;
  38
  39         if (cb)
  40                 err = cb(dev);
  41         scsi_device_resume(to_scsi_device(dev));
  42         dev_dbg(dev, "scsi resume: %d\n", err);
  43         return err;
  44 }
  45
  46 #ifdef CONFIG_PM_SLEEP
  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 identically.
  58                  */
  59                 if (pm_runtime_suspended(dev))
  60                         return 0;
  61
  62                 err = scsi_dev_type_suspend(dev, cb);
  63         }
  64
  65         return err;
  66 }
  67
  68 static int
  69 scsi_bus_resume_common(struct device *dev, int (*cb)(struct device *))
  70 {
  71         int err = 0;
  72
  73         if (scsi_is_sdev_device(dev))
  74                 err = scsi_dev_type_resume(dev, cb);
  75
  76         if (err == 0) {
  77                 pm_runtime_disable(dev);
  78                 pm_runtime_set_active(dev);
  79                 pm_runtime_enable(dev);
  80         }
  81         return err;
  82 }
  83
  84 static int scsi_bus_prepare(struct device *dev)
  85 {
  86         if (scsi_is_sdev_device(dev)) {
  87                 /* sd probing uses async_schedule.  Wait until it finishes. */
  88                 async_synchronize_full_domain(&scsi_sd_probe_domain);
  89
  90         } else if (scsi_is_host_device(dev)) {
  91                 /* Wait until async scanning is finished */
  92                 scsi_complete_async_scans();
  93         }
  94         return 0;
  95 }
  96
  97 static int scsi_bus_suspend(struct device *dev)
  98 {
  99         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 100         return scsi_bus_suspend_common(dev, pm ? pm->suspend : NULL);
 101 }
 102
 103 static int scsi_bus_resume(struct device *dev)
 104 {
 105         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 106         return scsi_bus_resume_common(dev, pm ? pm->resume : NULL);
 107 }
 108
 109 static int scsi_bus_freeze(struct device *dev)
 110 {
 111         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 112         return scsi_bus_suspend_common(dev, pm ? pm->freeze : NULL);
 113 }
 114
 115 static int scsi_bus_thaw(struct device *dev)
 116 {
 117         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 118         return scsi_bus_resume_common(dev, pm ? pm->thaw : NULL);
 119 }
 120
 121 static int scsi_bus_poweroff(struct device *dev)
 122 {
 123         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 124         return scsi_bus_suspend_common(dev, pm ? pm->poweroff : NULL);
 125 }
 126
 127 static int scsi_bus_restore(struct device *dev)
 128 {
 129         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 130         return scsi_bus_resume_common(dev, pm ? pm->restore : NULL);
 131 }
 132
 133 #else /* CONFIG_PM_SLEEP */
 134
 135 #define scsi_bus_prepare                NULL
 136 #define scsi_bus_suspend                NULL
 137 #define scsi_bus_resume                 NULL
 138 #define scsi_bus_freeze                 NULL
 139 #define scsi_bus_thaw                   NULL
 140 #define scsi_bus_poweroff               NULL
 141 #define scsi_bus_restore                NULL
 142
 143 #endif /* CONFIG_PM_SLEEP */
 144
 145 #ifdef CONFIG_PM_RUNTIME
 146
 147 static int scsi_runtime_suspend(struct device *dev)
 148 {
 149         int err = 0;
 150         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 151
 152         dev_dbg(dev, "scsi_runtime_suspend\n");
 153         if (scsi_is_sdev_device(dev)) {
 154                 err = scsi_dev_type_suspend(dev,
 155                                 pm ? pm->runtime_suspend : NULL);
 156                 if (err == -EAGAIN)
 157                         pm_schedule_suspend(dev, jiffies_to_msecs(
 158                                 round_jiffies_up_relative(HZ/10)));
 159         }
 160
 161         /* Insert hooks here for targets, hosts, and transport classes */
 162
 163         return err;
 164 }
 165
 166 static int scsi_runtime_resume(struct device *dev)
 167 {
 168         int err = 0;
 169         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 170
 171         dev_dbg(dev, "scsi_runtime_resume\n");
 172         if (scsi_is_sdev_device(dev))
 173                 err = scsi_dev_type_resume(dev, pm ? pm->runtime_resume : NULL);
 174
 175         /* Insert hooks here for targets, hosts, and transport classes */
 176
 177         return err;
 178 }
 179
 180 static int scsi_runtime_idle(struct device *dev)
 181 {
 182         int err;
 183
 184         dev_dbg(dev, "scsi_runtime_idle\n");
 185
 186         /* Insert hooks here for targets, hosts, and transport classes */
 187
 188         if (scsi_is_sdev_device(dev))
 189                 err = pm_schedule_suspend(dev, 100);
 190         else
 191                 err = pm_runtime_suspend(dev);
 192         return err;
 193 }
 194
 195 int scsi_autopm_get_device(struct scsi_device *sdev)
 196 {
 197         int     err;
 198
 199         err = pm_runtime_get_sync(&sdev->sdev_gendev);
 200         if (err < 0 && err !=-EACCES)
 201                 pm_runtime_put_sync(&sdev->sdev_gendev);
 202         else
 203                 err = 0;
 204         return err;
 205 }
 206 EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
 207
 208 void scsi_autopm_put_device(struct scsi_device *sdev)
 209 {
 210         pm_runtime_put_sync(&sdev->sdev_gendev);
 211 }
 212 EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
 213
 214 void scsi_autopm_get_target(struct scsi_target *starget)
 215 {
 216         pm_runtime_get_sync(&starget->dev);
 217 }
 218
 219 void scsi_autopm_put_target(struct scsi_target *starget)
 220 {
 221         pm_runtime_put_sync(&starget->dev);
 222 }
 223
 224 int scsi_autopm_get_host(struct Scsi_Host *shost)
 225 {
 226         int     err;
 227
 228         err = pm_runtime_get_sync(&shost->shost_gendev);
 229         if (err < 0 && err !=-EACCES)
 230                 pm_runtime_put_sync(&shost->shost_gendev);
 231         else
 232                 err = 0;
 233         return err;
 234 }
 235
 236 void scsi_autopm_put_host(struct Scsi_Host *shost)
 237 {
 238         pm_runtime_put_sync(&shost->shost_gendev);
 239 }
 240
 241 #else
 242
 243 #define scsi_runtime_suspend    NULL
 244 #define scsi_runtime_resume     NULL
 245 #define scsi_runtime_idle       NULL
 246
 247 #endif /* CONFIG_PM_RUNTIME */
 248
 249 const struct dev_pm_ops scsi_bus_pm_ops = {
 250         .prepare =              scsi_bus_prepare,
 251         .suspend =              scsi_bus_suspend,
 252         .resume =               scsi_bus_resume,
 253         .freeze =               scsi_bus_freeze,
 254         .thaw =                 scsi_bus_thaw,
 255         .poweroff =             scsi_bus_poweroff,
 256         .restore =              scsi_bus_restore,
 257         .runtime_suspend =      scsi_runtime_suspend,
 258         .runtime_resume =       scsi_runtime_resume,
 259         .runtime_idle =         scsi_runtime_idle,
 260 };