drivers/scsi/scsi_pm.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *      scsi_pm.c       Copyright (C) 2010 Alan Stern
   4  *
   5  *      SCSI dynamic Power Management
   6  *              Initial version: Alan Stern <stern@rowland.harvard.edu>
   7  */
   8
   9 #include <linux/pm_runtime.h>
  10 #include <linux/export.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         err = scsi_device_quiesce(to_scsi_device(dev));
  59         if (err == 0) {
  60                 err = cb(dev, pm);
  61                 if (err)
  62                         scsi_device_resume(to_scsi_device(dev));
  63         }
  64         dev_dbg(dev, "scsi suspend: %d\n", err);
  65         return err;
  66 }
  67
  68 static int
  69 scsi_bus_suspend_common(struct device *dev,
  70                 int (*cb)(struct device *, const struct dev_pm_ops *))
  71 {
  72         if (!scsi_is_sdev_device(dev))
  73                 return 0;
  74
  75         return scsi_dev_type_suspend(dev, cb);
  76 }
  77
  78 static int scsi_bus_resume_common(struct device *dev,
  79                 int (*cb)(struct device *, const struct dev_pm_ops *))
  80 {
  81         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
  82         int err;
  83
  84         if (!scsi_is_sdev_device(dev))
  85                 return 0;
  86
  87         err = cb(dev, pm);
  88         scsi_device_resume(to_scsi_device(dev));
  89         dev_dbg(dev, "scsi resume: %d\n", err);
  90
  91         return err;
  92 }
  93
  94 static int scsi_bus_prepare(struct device *dev)
  95 {
  96         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, do_scsi_suspend);
 106 }
 107
 108 static int scsi_bus_resume(struct device *dev)
 109 {
 110         return scsi_bus_resume_common(dev, do_scsi_resume);
 111 }
 112
 113 static int scsi_bus_freeze(struct device *dev)
 114 {
 115         return scsi_bus_suspend_common(dev, do_scsi_freeze);
 116 }
 117
 118 static int scsi_bus_thaw(struct device *dev)
 119 {
 120         return scsi_bus_resume_common(dev, do_scsi_thaw);
 121 }
 122
 123 static int scsi_bus_poweroff(struct device *dev)
 124 {
 125         return scsi_bus_suspend_common(dev, do_scsi_poweroff);
 126 }
 127
 128 static int scsi_bus_restore(struct device *dev)
 129 {
 130         return scsi_bus_resume_common(dev, do_scsi_restore);
 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 static int sdev_runtime_suspend(struct device *dev)
 146 {
 147         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 148         struct scsi_device *sdev = to_scsi_device(dev);
 149         int err = 0;
 150
 151         err = blk_pre_runtime_suspend(sdev->request_queue);
 152         if (err)
 153                 return err;
 154         if (pm && pm->runtime_suspend)
 155                 err = pm->runtime_suspend(dev);
 156         blk_post_runtime_suspend(sdev->request_queue, err);
 157
 158         return err;
 159 }
 160
 161 static int scsi_runtime_suspend(struct device *dev)
 162 {
 163         int err = 0;
 164
 165         dev_dbg(dev, "scsi_runtime_suspend\n");
 166         if (scsi_is_sdev_device(dev))
 167                 err = sdev_runtime_suspend(dev);
 168
 169         /* Insert hooks here for targets, hosts, and transport classes */
 170
 171         return err;
 172 }
 173
 174 static int sdev_runtime_resume(struct device *dev)
 175 {
 176         struct scsi_device *sdev = to_scsi_device(dev);
 177         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 178         int err = 0;
 179
 180         blk_pre_runtime_resume(sdev->request_queue);
 181         if (pm && pm->runtime_resume)
 182                 err = pm->runtime_resume(dev);
 183         blk_post_runtime_resume(sdev->request_queue);
 184
 185         return err;
 186 }
 187
 188 static int scsi_runtime_resume(struct device *dev)
 189 {
 190         int err = 0;
 191
 192         dev_dbg(dev, "scsi_runtime_resume\n");
 193         if (scsi_is_sdev_device(dev))
 194                 err = sdev_runtime_resume(dev);
 195
 196         /* Insert hooks here for targets, hosts, and transport classes */
 197
 198         return err;
 199 }
 200
 201 static int scsi_runtime_idle(struct device *dev)
 202 {
 203         dev_dbg(dev, "scsi_runtime_idle\n");
 204
 205         /* Insert hooks here for targets, hosts, and transport classes */
 206
 207         if (scsi_is_sdev_device(dev)) {
 208                 pm_runtime_mark_last_busy(dev);
 209                 pm_runtime_autosuspend(dev);
 210                 return -EBUSY;
 211         }
 212
 213         return 0;
 214 }
 215
 216 int scsi_autopm_get_device(struct scsi_device *sdev)
 217 {
 218         int     err;
 219
 220         err = pm_runtime_get_sync(&sdev->sdev_gendev);
 221         if (err < 0 && err !=-EACCES)
 222                 pm_runtime_put_sync(&sdev->sdev_gendev);
 223         else
 224                 err = 0;
 225         return err;
 226 }
 227 EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
 228
 229 void scsi_autopm_put_device(struct scsi_device *sdev)
 230 {
 231         pm_runtime_put_sync(&sdev->sdev_gendev);
 232 }
 233 EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
 234
 235 void scsi_autopm_get_target(struct scsi_target *starget)
 236 {
 237         pm_runtime_get_sync(&starget->dev);
 238 }
 239
 240 void scsi_autopm_put_target(struct scsi_target *starget)
 241 {
 242         pm_runtime_put_sync(&starget->dev);
 243 }
 244
 245 int scsi_autopm_get_host(struct Scsi_Host *shost)
 246 {
 247         int     err;
 248
 249         err = pm_runtime_get_sync(&shost->shost_gendev);
 250         if (err < 0 && err !=-EACCES)
 251                 pm_runtime_put_sync(&shost->shost_gendev);
 252         else
 253                 err = 0;
 254         return err;
 255 }
 256
 257 void scsi_autopm_put_host(struct Scsi_Host *shost)
 258 {
 259         pm_runtime_put_sync(&shost->shost_gendev);
 260 }
 261
 262 const struct dev_pm_ops scsi_bus_pm_ops = {
 263         .prepare =              scsi_bus_prepare,
 264         .suspend =              scsi_bus_suspend,
 265         .resume =               scsi_bus_resume,
 266         .freeze =               scsi_bus_freeze,
 267         .thaw =                 scsi_bus_thaw,
 268         .poweroff =             scsi_bus_poweroff,
 269         .restore =              scsi_bus_restore,
 270         .runtime_suspend =      scsi_runtime_suspend,
 271         .runtime_resume =       scsi_runtime_resume,
 272         .runtime_idle =         scsi_runtime_idle,
 273 };