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, pm_message_t msg)
  20 {
  21         struct device_driver *drv;
  22         int err;
  23
  24         err = scsi_device_quiesce(to_scsi_device(dev));
  25         if (err == 0) {
  26                 drv = dev->driver;
  27                 if (drv && drv->suspend) {
  28                         err = drv->suspend(dev, msg);
  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)
  38 {
  39         struct device_driver *drv;
  40         int err = 0;
  41
  42         drv = dev->driver;
  43         if (drv && drv->resume)
  44                 err = drv->resume(dev);
  45         scsi_device_resume(to_scsi_device(dev));
  46         dev_dbg(dev, "scsi resume: %d\n", err);
  47         return err;
  48 }
  49
  50 #ifdef CONFIG_PM_SLEEP
  51
  52 static int scsi_bus_suspend_common(struct device *dev, pm_message_t msg)
  53 {
  54         int err = 0;
  55
  56         if (scsi_is_sdev_device(dev)) {
  57                 /*
  58                  * sd is the only high-level SCSI driver to implement runtime
  59                  * PM, and sd treats runtime suspend, system suspend, and
  60                  * system hibernate identically (but not system freeze).
  61                  */
  62                 if (pm_runtime_suspended(dev)) {
  63                         if (msg.event == PM_EVENT_SUSPEND ||
  64                             msg.event == PM_EVENT_HIBERNATE)
  65                                 return 0;       /* already suspended */
  66
  67                         /* wake up device so that FREEZE will succeed */
  68                         pm_runtime_resume(dev);
  69                 }
  70                 err = scsi_dev_type_suspend(dev, msg);
  71         }
  72         return err;
  73 }
  74
  75 static int scsi_bus_resume_common(struct device *dev)
  76 {
  77         int err = 0;
  78
  79         if (scsi_is_sdev_device(dev))
  80                 err = scsi_dev_type_resume(dev);
  81
  82         if (err == 0) {
  83                 pm_runtime_disable(dev);
  84                 pm_runtime_set_active(dev);
  85                 pm_runtime_enable(dev);
  86         }
  87         return err;
  88 }
  89
  90 static int scsi_bus_prepare(struct device *dev)
  91 {
  92         if (scsi_is_sdev_device(dev)) {
  93                 /* sd probing uses async_schedule.  Wait until it finishes. */
  94                 async_synchronize_full_domain(&scsi_sd_probe_domain);
  95
  96         } else if (scsi_is_host_device(dev)) {
  97                 /* Wait until async scanning is finished */
  98                 scsi_complete_async_scans();
  99         }
 100         return 0;
 101 }
 102
 103 static int scsi_bus_suspend(struct device *dev)
 104 {
 105         return scsi_bus_suspend_common(dev, PMSG_SUSPEND);
 106 }
 107
 108 static int scsi_bus_freeze(struct device *dev)
 109 {
 110         return scsi_bus_suspend_common(dev, PMSG_FREEZE);
 111 }
 112
 113 static int scsi_bus_poweroff(struct device *dev)
 114 {
 115         return scsi_bus_suspend_common(dev, PMSG_HIBERNATE);
 116 }
 117
 118 #else /* CONFIG_PM_SLEEP */
 119
 120 #define scsi_bus_resume_common          NULL
 121 #define scsi_bus_prepare                NULL
 122 #define scsi_bus_suspend                NULL
 123 #define scsi_bus_freeze                 NULL
 124 #define scsi_bus_poweroff               NULL
 125
 126 #endif /* CONFIG_PM_SLEEP */
 127
 128 #ifdef CONFIG_PM_RUNTIME
 129
 130 static int scsi_runtime_suspend(struct device *dev)
 131 {
 132         int err = 0;
 133
 134         dev_dbg(dev, "scsi_runtime_suspend\n");
 135         if (scsi_is_sdev_device(dev)) {
 136                 err = scsi_dev_type_suspend(dev, PMSG_AUTO_SUSPEND);
 137                 if (err == -EAGAIN)
 138                         pm_schedule_suspend(dev, jiffies_to_msecs(
 139                                 round_jiffies_up_relative(HZ/10)));
 140         }
 141
 142         /* Insert hooks here for targets, hosts, and transport classes */
 143
 144         return err;
 145 }
 146
 147 static int scsi_runtime_resume(struct device *dev)
 148 {
 149         int err = 0;
 150
 151         dev_dbg(dev, "scsi_runtime_resume\n");
 152         if (scsi_is_sdev_device(dev))
 153                 err = scsi_dev_type_resume(dev);
 154
 155         /* Insert hooks here for targets, hosts, and transport classes */
 156
 157         return err;
 158 }
 159
 160 static int scsi_runtime_idle(struct device *dev)
 161 {
 162         int err;
 163
 164         dev_dbg(dev, "scsi_runtime_idle\n");
 165
 166         /* Insert hooks here for targets, hosts, and transport classes */
 167
 168         if (scsi_is_sdev_device(dev))
 169                 err = pm_schedule_suspend(dev, 100);
 170         else
 171                 err = pm_runtime_suspend(dev);
 172         return err;
 173 }
 174
 175 int scsi_autopm_get_device(struct scsi_device *sdev)
 176 {
 177         int     err;
 178
 179         err = pm_runtime_get_sync(&sdev->sdev_gendev);
 180         if (err < 0 && err !=-EACCES)
 181                 pm_runtime_put_sync(&sdev->sdev_gendev);
 182         else
 183                 err = 0;
 184         return err;
 185 }
 186 EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
 187
 188 void scsi_autopm_put_device(struct scsi_device *sdev)
 189 {
 190         pm_runtime_put_sync(&sdev->sdev_gendev);
 191 }
 192 EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
 193
 194 void scsi_autopm_get_target(struct scsi_target *starget)
 195 {
 196         pm_runtime_get_sync(&starget->dev);
 197 }
 198
 199 void scsi_autopm_put_target(struct scsi_target *starget)
 200 {
 201         pm_runtime_put_sync(&starget->dev);
 202 }
 203
 204 int scsi_autopm_get_host(struct Scsi_Host *shost)
 205 {
 206         int     err;
 207
 208         err = pm_runtime_get_sync(&shost->shost_gendev);
 209         if (err < 0 && err !=-EACCES)
 210                 pm_runtime_put_sync(&shost->shost_gendev);
 211         else
 212                 err = 0;
 213         return err;
 214 }
 215
 216 void scsi_autopm_put_host(struct Scsi_Host *shost)
 217 {
 218         pm_runtime_put_sync(&shost->shost_gendev);
 219 }
 220
 221 #else
 222
 223 #define scsi_runtime_suspend    NULL
 224 #define scsi_runtime_resume     NULL
 225 #define scsi_runtime_idle       NULL
 226
 227 #endif /* CONFIG_PM_RUNTIME */
 228
 229 const struct dev_pm_ops scsi_bus_pm_ops = {
 230         .prepare =              scsi_bus_prepare,
 231         .suspend =              scsi_bus_suspend,
 232         .resume =               scsi_bus_resume_common,
 233         .freeze =               scsi_bus_freeze,
 234         .thaw =                 scsi_bus_resume_common,
 235         .poweroff =             scsi_bus_poweroff,
 236         .restore =              scsi_bus_resume_common,
 237         .runtime_suspend =      scsi_runtime_suspend,
 238         .runtime_resume =       scsi_runtime_resume,
 239         .runtime_idle =         scsi_runtime_idle,
 240 };