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 21static int do_scsi_suspend(struct device *dev, const struct dev_pm_ops *pm) 22{ 23 return pm && pm->suspend ? pm->suspend(dev) : 0; 24} 25 26static int do_scsi_freeze(struct device *dev, const struct dev_pm_ops *pm) 27{ 28 return pm && pm->freeze ? pm->freeze(dev) : 0; 29} 30 31static int do_scsi_poweroff(struct device *dev, const struct dev_pm_ops *pm) 32{ 33 return pm && pm->poweroff ? pm->poweroff(dev) : 0; 34} 35 36static int do_scsi_resume(struct device *dev, const struct dev_pm_ops *pm) 37{ 38 return pm && pm->resume ? pm->resume(dev) : 0; 39} 40 41static int do_scsi_thaw(struct device *dev, const struct dev_pm_ops *pm) 42{ 43 return pm && pm->thaw ? pm->thaw(dev) : 0; 44} 45 46static int do_scsi_restore(struct device *dev, const struct dev_pm_ops *pm) 47{ 48 return pm && pm->restore ? pm->restore(dev) : 0; 49} 50 51static int scsi_dev_type_suspend(struct device *dev, 52 int (*cb)(struct device *, const struct dev_pm_ops *)) 53{ 54 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; 55 int err; 56 57 /* flush pending in-flight resume operations, suspend is synchronous */ 58 async_synchronize_full_domain(&scsi_sd_pm_domain); 59 60 err = scsi_device_quiesce(to_scsi_device(dev)); 61 if (err == 0) { 62 err = cb(dev, pm); 63 if (err) 64 scsi_device_resume(to_scsi_device(dev)); 65 } 66 dev_dbg(dev, "scsi suspend: %d\n", err); 67 return err; 68} 69 70static int scsi_dev_type_resume(struct device *dev, 71 int (*cb)(struct device *, const struct dev_pm_ops *)) 72{ 73 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; 74 int err = 0; 75 76 err = cb(dev, pm); 77 scsi_device_resume(to_scsi_device(dev)); 78 dev_dbg(dev, "scsi resume: %d\n", err); 79 80 if (err == 0) { 81 pm_runtime_disable(dev); 82 pm_runtime_set_active(dev); 83 pm_runtime_enable(dev); 84 } 85 86 return err; 87} 88 89static int 90scsi_bus_suspend_common(struct device *dev, 91 int (*cb)(struct device *, const struct dev_pm_ops *)) 92{ 93 int err = 0; 94 95 if (scsi_is_sdev_device(dev)) { 96 /* 97 * All the high-level SCSI drivers that implement runtime 98 * PM treat runtime suspend, system suspend, and system 99 * hibernate nearly identically. In all cases the requirements 100 * for runtime suspension are stricter. 101 */ 102 if (pm_runtime_suspended(dev)) 103 return 0; 104 105 err = scsi_dev_type_suspend(dev, cb); 106 } 107 108 return err; 109} 110 111static void async_sdev_resume(void *dev, async_cookie_t cookie) 112{ 113 scsi_dev_type_resume(dev, do_scsi_resume); 114} 115 116static void async_sdev_thaw(void *dev, async_cookie_t cookie) 117{ 118 scsi_dev_type_resume(dev, do_scsi_thaw); 119} 120 121static void async_sdev_restore(void *dev, async_cookie_t cookie) 122{ 123 scsi_dev_type_resume(dev, do_scsi_restore); 124} 125 126static int scsi_bus_resume_common(struct device *dev, 127 int (*cb)(struct device *, const struct dev_pm_ops *)) 128{ 129 async_func_t fn; 130 131 if (!scsi_is_sdev_device(dev)) 132 fn = NULL; 133 else if (cb == do_scsi_resume) 134 fn = async_sdev_resume; 135 else if (cb == do_scsi_thaw) 136 fn = async_sdev_thaw; 137 else if (cb == do_scsi_restore) 138 fn = async_sdev_restore; 139 else 140 fn = NULL; 141 142 if (fn) { 143 async_schedule_domain(fn, dev, &scsi_sd_pm_domain); 144 145 /* 146 * If a user has disabled async probing a likely reason 147 * is due to a storage enclosure that does not inject 148 * staggered spin-ups. For safety, make resume 149 * synchronous as well in that case. 150 */ 151 if (strncmp(scsi_scan_type, "async", 5) != 0) 152 async_synchronize_full_domain(&scsi_sd_pm_domain); 153 } else { 154 pm_runtime_disable(dev); 155 pm_runtime_set_active(dev); 156 pm_runtime_enable(dev); 157 } 158 return 0; 159} 160 161static int scsi_bus_prepare(struct device *dev) 162{ 163 if (scsi_is_sdev_device(dev)) { 164 /* sd probing uses async_schedule. Wait until it finishes. */ 165 async_synchronize_full_domain(&scsi_sd_probe_domain); 166 167 } else if (scsi_is_host_device(dev)) { 168 /* Wait until async scanning is finished */ 169 scsi_complete_async_scans(); 170 } 171 return 0; 172} 173 174static int scsi_bus_suspend(struct device *dev) 175{ 176 return scsi_bus_suspend_common(dev, do_scsi_suspend); 177} 178 179static int scsi_bus_resume(struct device *dev) 180{ 181 return scsi_bus_resume_common(dev, do_scsi_resume); 182} 183 184static int scsi_bus_freeze(struct device *dev) 185{ 186 return scsi_bus_suspend_common(dev, do_scsi_freeze); 187} 188 189static int scsi_bus_thaw(struct device *dev) 190{ 191 return scsi_bus_resume_common(dev, do_scsi_thaw); 192} 193 194static int scsi_bus_poweroff(struct device *dev) 195{ 196 return scsi_bus_suspend_common(dev, do_scsi_poweroff); 197} 198 199static int scsi_bus_restore(struct device *dev) 200{ 201 return scsi_bus_resume_common(dev, do_scsi_restore); 202} 203 204#else /* CONFIG_PM_SLEEP */ 205 206#define scsi_bus_prepare NULL 207#define scsi_bus_suspend NULL 208#define scsi_bus_resume NULL 209#define scsi_bus_freeze NULL 210#define scsi_bus_thaw NULL 211#define scsi_bus_poweroff NULL 212#define scsi_bus_restore NULL 213 214#endif /* CONFIG_PM_SLEEP */ 215 216static int sdev_runtime_suspend(struct device *dev) 217{ 218 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; 219 struct scsi_device *sdev = to_scsi_device(dev); 220 int err = 0; 221 222 err = blk_pre_runtime_suspend(sdev->request_queue); 223 if (err) 224 return err; 225 if (pm && pm->runtime_suspend) 226 err = pm->runtime_suspend(dev); 227 blk_post_runtime_suspend(sdev->request_queue, err); 228 229 return err; 230} 231 232static int scsi_runtime_suspend(struct device *dev) 233{ 234 int err = 0; 235 236 dev_dbg(dev, "scsi_runtime_suspend\n"); 237 if (scsi_is_sdev_device(dev)) 238 err = sdev_runtime_suspend(dev); 239 240 /* Insert hooks here for targets, hosts, and transport classes */ 241 242 return err; 243} 244 245static int sdev_runtime_resume(struct device *dev) 246{ 247 struct scsi_device *sdev = to_scsi_device(dev); 248 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; 249 int err = 0; 250 251 blk_pre_runtime_resume(sdev->request_queue); 252 if (pm && pm->runtime_resume) 253 err = pm->runtime_resume(dev); 254 blk_post_runtime_resume(sdev->request_queue, err); 255 256 return err; 257} 258 259static int scsi_runtime_resume(struct device *dev) 260{ 261 int err = 0; 262 263 dev_dbg(dev, "scsi_runtime_resume\n"); 264 if (scsi_is_sdev_device(dev)) 265 err = sdev_runtime_resume(dev); 266 267 /* Insert hooks here for targets, hosts, and transport classes */ 268 269 return err; 270} 271 272static int scsi_runtime_idle(struct device *dev) 273{ 274 dev_dbg(dev, "scsi_runtime_idle\n"); 275 276 /* Insert hooks here for targets, hosts, and transport classes */ 277 278 if (scsi_is_sdev_device(dev)) { 279 pm_runtime_mark_last_busy(dev); 280 pm_runtime_autosuspend(dev); 281 return -EBUSY; 282 } 283 284 return 0; 285} 286 287int scsi_autopm_get_device(struct scsi_device *sdev) 288{ 289 int err; 290 291 err = pm_runtime_get_sync(&sdev->sdev_gendev); 292 if (err < 0 && err !=-EACCES) 293 pm_runtime_put_sync(&sdev->sdev_gendev); 294 else 295 err = 0; 296 return err; 297} 298EXPORT_SYMBOL_GPL(scsi_autopm_get_device); 299 300void scsi_autopm_put_device(struct scsi_device *sdev) 301{ 302 pm_runtime_put_sync(&sdev->sdev_gendev); 303} 304EXPORT_SYMBOL_GPL(scsi_autopm_put_device); 305 306void scsi_autopm_get_target(struct scsi_target *starget) 307{ 308 pm_runtime_get_sync(&starget->dev); 309} 310 311void scsi_autopm_put_target(struct scsi_target *starget) 312{ 313 pm_runtime_put_sync(&starget->dev); 314} 315 316int scsi_autopm_get_host(struct Scsi_Host *shost) 317{ 318 int err; 319 320 err = pm_runtime_get_sync(&shost->shost_gendev); 321 if (err < 0 && err !=-EACCES) 322 pm_runtime_put_sync(&shost->shost_gendev); 323 else 324 err = 0; 325 return err; 326} 327 328void scsi_autopm_put_host(struct Scsi_Host *shost) 329{ 330 pm_runtime_put_sync(&shost->shost_gendev); 331} 332 333const struct dev_pm_ops scsi_bus_pm_ops = { 334 .prepare = scsi_bus_prepare, 335 .suspend = scsi_bus_suspend, 336 .resume = scsi_bus_resume, 337 .freeze = scsi_bus_freeze, 338 .thaw = scsi_bus_thaw, 339 .poweroff = scsi_bus_poweroff, 340 .restore = scsi_bus_restore, 341 .runtime_suspend = scsi_runtime_suspend, 342 .runtime_resume = scsi_runtime_resume, 343 .runtime_idle = scsi_runtime_idle, 344}; 345