| 1 | /* |
| 2 | * This module exposes the interface to kernel space for specifying |
| 3 | * QoS dependencies. It provides infrastructure for registration of: |
| 4 | * |
| 5 | * Dependents on a QoS value : register requests |
| 6 | * Watchers of QoS value : get notified when target QoS value changes |
| 7 | * |
| 8 | * This QoS design is best effort based. Dependents register their QoS needs. |
| 9 | * Watchers register to keep track of the current QoS needs of the system. |
| 10 | * |
| 11 | * There are 3 basic classes of QoS parameter: latency, timeout, throughput |
| 12 | * each have defined units: |
| 13 | * latency: usec |
| 14 | * timeout: usec <-- currently not used. |
| 15 | * throughput: kbs (kilo byte / sec) |
| 16 | * |
| 17 | * There are lists of pm_qos_objects each one wrapping requests, notifiers |
| 18 | * |
| 19 | * User mode requests on a QOS parameter register themselves to the |
| 20 | * subsystem by opening the device node /dev/... and writing there request to |
| 21 | * the node. As long as the process holds a file handle open to the node the |
| 22 | * client continues to be accounted for. Upon file release the usermode |
| 23 | * request is removed and a new qos target is computed. This way when the |
| 24 | * request that the application has is cleaned up when closes the file |
| 25 | * pointer or exits the pm_qos_object will get an opportunity to clean up. |
| 26 | * |
| 27 | * Mark Gross <mgross@linux.intel.com> |
| 28 | */ |
| 29 | |
| 30 | /*#define DEBUG*/ |
| 31 | |
| 32 | #include <linux/pm_qos.h> |
| 33 | #include <linux/sched.h> |
| 34 | #include <linux/spinlock.h> |
| 35 | #include <linux/slab.h> |
| 36 | #include <linux/time.h> |
| 37 | #include <linux/fs.h> |
| 38 | #include <linux/device.h> |
| 39 | #include <linux/miscdevice.h> |
| 40 | #include <linux/string.h> |
| 41 | #include <linux/platform_device.h> |
| 42 | #include <linux/init.h> |
| 43 | #include <linux/kernel.h> |
| 44 | |
| 45 | #include <linux/uaccess.h> |
| 46 | #include <linux/export.h> |
| 47 | |
| 48 | /* |
| 49 | * locking rule: all changes to constraints or notifiers lists |
| 50 | * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock |
| 51 | * held, taken with _irqsave. One lock to rule them all |
| 52 | */ |
| 53 | struct pm_qos_object { |
| 54 | struct pm_qos_constraints *constraints; |
| 55 | struct miscdevice pm_qos_power_miscdev; |
| 56 | char *name; |
| 57 | }; |
| 58 | |
| 59 | static DEFINE_SPINLOCK(pm_qos_lock); |
| 60 | |
| 61 | static struct pm_qos_object null_pm_qos; |
| 62 | |
| 63 | static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier); |
| 64 | static struct pm_qos_constraints cpu_dma_constraints = { |
| 65 | .list = PLIST_HEAD_INIT(cpu_dma_constraints.list), |
| 66 | .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, |
| 67 | .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, |
| 68 | .type = PM_QOS_MIN, |
| 69 | .notifiers = &cpu_dma_lat_notifier, |
| 70 | }; |
| 71 | static struct pm_qos_object cpu_dma_pm_qos = { |
| 72 | .constraints = &cpu_dma_constraints, |
| 73 | .name = "cpu_dma_latency", |
| 74 | }; |
| 75 | |
| 76 | static BLOCKING_NOTIFIER_HEAD(network_lat_notifier); |
| 77 | static struct pm_qos_constraints network_lat_constraints = { |
| 78 | .list = PLIST_HEAD_INIT(network_lat_constraints.list), |
| 79 | .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, |
| 80 | .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, |
| 81 | .type = PM_QOS_MIN, |
| 82 | .notifiers = &network_lat_notifier, |
| 83 | }; |
| 84 | static struct pm_qos_object network_lat_pm_qos = { |
| 85 | .constraints = &network_lat_constraints, |
| 86 | .name = "network_latency", |
| 87 | }; |
| 88 | |
| 89 | |
| 90 | static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier); |
| 91 | static struct pm_qos_constraints network_tput_constraints = { |
| 92 | .list = PLIST_HEAD_INIT(network_tput_constraints.list), |
| 93 | .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, |
| 94 | .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, |
| 95 | .type = PM_QOS_MAX, |
| 96 | .notifiers = &network_throughput_notifier, |
| 97 | }; |
| 98 | static struct pm_qos_object network_throughput_pm_qos = { |
| 99 | .constraints = &network_tput_constraints, |
| 100 | .name = "network_throughput", |
| 101 | }; |
| 102 | |
| 103 | |
| 104 | static struct pm_qos_object *pm_qos_array[] = { |
| 105 | &null_pm_qos, |
| 106 | &cpu_dma_pm_qos, |
| 107 | &network_lat_pm_qos, |
| 108 | &network_throughput_pm_qos |
| 109 | }; |
| 110 | |
| 111 | static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, |
| 112 | size_t count, loff_t *f_pos); |
| 113 | static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, |
| 114 | size_t count, loff_t *f_pos); |
| 115 | static int pm_qos_power_open(struct inode *inode, struct file *filp); |
| 116 | static int pm_qos_power_release(struct inode *inode, struct file *filp); |
| 117 | |
| 118 | static const struct file_operations pm_qos_power_fops = { |
| 119 | .write = pm_qos_power_write, |
| 120 | .read = pm_qos_power_read, |
| 121 | .open = pm_qos_power_open, |
| 122 | .release = pm_qos_power_release, |
| 123 | .llseek = noop_llseek, |
| 124 | }; |
| 125 | |
| 126 | /* unlocked internal variant */ |
| 127 | static inline int pm_qos_get_value(struct pm_qos_constraints *c) |
| 128 | { |
| 129 | if (plist_head_empty(&c->list)) |
| 130 | return c->default_value; |
| 131 | |
| 132 | switch (c->type) { |
| 133 | case PM_QOS_MIN: |
| 134 | return plist_first(&c->list)->prio; |
| 135 | |
| 136 | case PM_QOS_MAX: |
| 137 | return plist_last(&c->list)->prio; |
| 138 | |
| 139 | default: |
| 140 | /* runtime check for not using enum */ |
| 141 | BUG(); |
| 142 | return PM_QOS_DEFAULT_VALUE; |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | s32 pm_qos_read_value(struct pm_qos_constraints *c) |
| 147 | { |
| 148 | return c->target_value; |
| 149 | } |
| 150 | |
| 151 | static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) |
| 152 | { |
| 153 | c->target_value = value; |
| 154 | } |
| 155 | |
| 156 | /** |
| 157 | * pm_qos_update_target - manages the constraints list and calls the notifiers |
| 158 | * if needed |
| 159 | * @c: constraints data struct |
| 160 | * @node: request to add to the list, to update or to remove |
| 161 | * @action: action to take on the constraints list |
| 162 | * @value: value of the request to add or update |
| 163 | * |
| 164 | * This function returns 1 if the aggregated constraint value has changed, 0 |
| 165 | * otherwise. |
| 166 | */ |
| 167 | int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, |
| 168 | enum pm_qos_req_action action, int value) |
| 169 | { |
| 170 | unsigned long flags; |
| 171 | int prev_value, curr_value, new_value; |
| 172 | |
| 173 | spin_lock_irqsave(&pm_qos_lock, flags); |
| 174 | prev_value = pm_qos_get_value(c); |
| 175 | if (value == PM_QOS_DEFAULT_VALUE) |
| 176 | new_value = c->default_value; |
| 177 | else |
| 178 | new_value = value; |
| 179 | |
| 180 | switch (action) { |
| 181 | case PM_QOS_REMOVE_REQ: |
| 182 | plist_del(node, &c->list); |
| 183 | break; |
| 184 | case PM_QOS_UPDATE_REQ: |
| 185 | /* |
| 186 | * to change the list, we atomically remove, reinit |
| 187 | * with new value and add, then see if the extremal |
| 188 | * changed |
| 189 | */ |
| 190 | plist_del(node, &c->list); |
| 191 | case PM_QOS_ADD_REQ: |
| 192 | plist_node_init(node, new_value); |
| 193 | plist_add(node, &c->list); |
| 194 | break; |
| 195 | default: |
| 196 | /* no action */ |
| 197 | ; |
| 198 | } |
| 199 | |
| 200 | curr_value = pm_qos_get_value(c); |
| 201 | pm_qos_set_value(c, curr_value); |
| 202 | |
| 203 | spin_unlock_irqrestore(&pm_qos_lock, flags); |
| 204 | |
| 205 | if (prev_value != curr_value) { |
| 206 | blocking_notifier_call_chain(c->notifiers, |
| 207 | (unsigned long)curr_value, |
| 208 | NULL); |
| 209 | return 1; |
| 210 | } else { |
| 211 | return 0; |
| 212 | } |
| 213 | } |
| 214 | |
| 215 | /** |
| 216 | * pm_qos_flags_remove_req - Remove device PM QoS flags request. |
| 217 | * @pqf: Device PM QoS flags set to remove the request from. |
| 218 | * @req: Request to remove from the set. |
| 219 | */ |
| 220 | static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf, |
| 221 | struct pm_qos_flags_request *req) |
| 222 | { |
| 223 | s32 val = 0; |
| 224 | |
| 225 | list_del(&req->node); |
| 226 | list_for_each_entry(req, &pqf->list, node) |
| 227 | val |= req->flags; |
| 228 | |
| 229 | pqf->effective_flags = val; |
| 230 | } |
| 231 | |
| 232 | /** |
| 233 | * pm_qos_update_flags - Update a set of PM QoS flags. |
| 234 | * @pqf: Set of flags to update. |
| 235 | * @req: Request to add to the set, to modify, or to remove from the set. |
| 236 | * @action: Action to take on the set. |
| 237 | * @val: Value of the request to add or modify. |
| 238 | * |
| 239 | * Update the given set of PM QoS flags and call notifiers if the aggregate |
| 240 | * value has changed. Returns 1 if the aggregate constraint value has changed, |
| 241 | * 0 otherwise. |
| 242 | */ |
| 243 | bool pm_qos_update_flags(struct pm_qos_flags *pqf, |
| 244 | struct pm_qos_flags_request *req, |
| 245 | enum pm_qos_req_action action, s32 val) |
| 246 | { |
| 247 | unsigned long irqflags; |
| 248 | s32 prev_value, curr_value; |
| 249 | |
| 250 | spin_lock_irqsave(&pm_qos_lock, irqflags); |
| 251 | |
| 252 | prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags; |
| 253 | |
| 254 | switch (action) { |
| 255 | case PM_QOS_REMOVE_REQ: |
| 256 | pm_qos_flags_remove_req(pqf, req); |
| 257 | break; |
| 258 | case PM_QOS_UPDATE_REQ: |
| 259 | pm_qos_flags_remove_req(pqf, req); |
| 260 | case PM_QOS_ADD_REQ: |
| 261 | req->flags = val; |
| 262 | INIT_LIST_HEAD(&req->node); |
| 263 | list_add_tail(&req->node, &pqf->list); |
| 264 | pqf->effective_flags |= val; |
| 265 | break; |
| 266 | default: |
| 267 | /* no action */ |
| 268 | ; |
| 269 | } |
| 270 | |
| 271 | curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags; |
| 272 | |
| 273 | spin_unlock_irqrestore(&pm_qos_lock, irqflags); |
| 274 | |
| 275 | return prev_value != curr_value; |
| 276 | } |
| 277 | |
| 278 | /** |
| 279 | * pm_qos_request - returns current system wide qos expectation |
| 280 | * @pm_qos_class: identification of which qos value is requested |
| 281 | * |
| 282 | * This function returns the current target value. |
| 283 | */ |
| 284 | int pm_qos_request(int pm_qos_class) |
| 285 | { |
| 286 | return pm_qos_read_value(pm_qos_array[pm_qos_class]->constraints); |
| 287 | } |
| 288 | EXPORT_SYMBOL_GPL(pm_qos_request); |
| 289 | |
| 290 | int pm_qos_request_active(struct pm_qos_request *req) |
| 291 | { |
| 292 | return req->pm_qos_class != 0; |
| 293 | } |
| 294 | EXPORT_SYMBOL_GPL(pm_qos_request_active); |
| 295 | |
| 296 | /** |
| 297 | * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout |
| 298 | * @work: work struct for the delayed work (timeout) |
| 299 | * |
| 300 | * This cancels the timeout request by falling back to the default at timeout. |
| 301 | */ |
| 302 | static void pm_qos_work_fn(struct work_struct *work) |
| 303 | { |
| 304 | struct pm_qos_request *req = container_of(to_delayed_work(work), |
| 305 | struct pm_qos_request, |
| 306 | work); |
| 307 | |
| 308 | pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE); |
| 309 | } |
| 310 | |
| 311 | /** |
| 312 | * pm_qos_add_request - inserts new qos request into the list |
| 313 | * @req: pointer to a preallocated handle |
| 314 | * @pm_qos_class: identifies which list of qos request to use |
| 315 | * @value: defines the qos request |
| 316 | * |
| 317 | * This function inserts a new entry in the pm_qos_class list of requested qos |
| 318 | * performance characteristics. It recomputes the aggregate QoS expectations |
| 319 | * for the pm_qos_class of parameters and initializes the pm_qos_request |
| 320 | * handle. Caller needs to save this handle for later use in updates and |
| 321 | * removal. |
| 322 | */ |
| 323 | |
| 324 | void pm_qos_add_request(struct pm_qos_request *req, |
| 325 | int pm_qos_class, s32 value) |
| 326 | { |
| 327 | if (!req) /*guard against callers passing in null */ |
| 328 | return; |
| 329 | |
| 330 | if (pm_qos_request_active(req)) { |
| 331 | WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); |
| 332 | return; |
| 333 | } |
| 334 | req->pm_qos_class = pm_qos_class; |
| 335 | INIT_DELAYED_WORK(&req->work, pm_qos_work_fn); |
| 336 | pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints, |
| 337 | &req->node, PM_QOS_ADD_REQ, value); |
| 338 | } |
| 339 | EXPORT_SYMBOL_GPL(pm_qos_add_request); |
| 340 | |
| 341 | /** |
| 342 | * pm_qos_update_request - modifies an existing qos request |
| 343 | * @req : handle to list element holding a pm_qos request to use |
| 344 | * @value: defines the qos request |
| 345 | * |
| 346 | * Updates an existing qos request for the pm_qos_class of parameters along |
| 347 | * with updating the target pm_qos_class value. |
| 348 | * |
| 349 | * Attempts are made to make this code callable on hot code paths. |
| 350 | */ |
| 351 | void pm_qos_update_request(struct pm_qos_request *req, |
| 352 | s32 new_value) |
| 353 | { |
| 354 | if (!req) /*guard against callers passing in null */ |
| 355 | return; |
| 356 | |
| 357 | if (!pm_qos_request_active(req)) { |
| 358 | WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n"); |
| 359 | return; |
| 360 | } |
| 361 | |
| 362 | if (delayed_work_pending(&req->work)) |
| 363 | cancel_delayed_work_sync(&req->work); |
| 364 | |
| 365 | if (new_value != req->node.prio) |
| 366 | pm_qos_update_target( |
| 367 | pm_qos_array[req->pm_qos_class]->constraints, |
| 368 | &req->node, PM_QOS_UPDATE_REQ, new_value); |
| 369 | } |
| 370 | EXPORT_SYMBOL_GPL(pm_qos_update_request); |
| 371 | |
| 372 | /** |
| 373 | * pm_qos_update_request_timeout - modifies an existing qos request temporarily. |
| 374 | * @req : handle to list element holding a pm_qos request to use |
| 375 | * @new_value: defines the temporal qos request |
| 376 | * @timeout_us: the effective duration of this qos request in usecs. |
| 377 | * |
| 378 | * After timeout_us, this qos request is cancelled automatically. |
| 379 | */ |
| 380 | void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, |
| 381 | unsigned long timeout_us) |
| 382 | { |
| 383 | if (!req) |
| 384 | return; |
| 385 | if (WARN(!pm_qos_request_active(req), |
| 386 | "%s called for unknown object.", __func__)) |
| 387 | return; |
| 388 | |
| 389 | if (delayed_work_pending(&req->work)) |
| 390 | cancel_delayed_work_sync(&req->work); |
| 391 | |
| 392 | if (new_value != req->node.prio) |
| 393 | pm_qos_update_target( |
| 394 | pm_qos_array[req->pm_qos_class]->constraints, |
| 395 | &req->node, PM_QOS_UPDATE_REQ, new_value); |
| 396 | |
| 397 | schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us)); |
| 398 | } |
| 399 | |
| 400 | /** |
| 401 | * pm_qos_remove_request - modifies an existing qos request |
| 402 | * @req: handle to request list element |
| 403 | * |
| 404 | * Will remove pm qos request from the list of constraints and |
| 405 | * recompute the current target value for the pm_qos_class. Call this |
| 406 | * on slow code paths. |
| 407 | */ |
| 408 | void pm_qos_remove_request(struct pm_qos_request *req) |
| 409 | { |
| 410 | if (!req) /*guard against callers passing in null */ |
| 411 | return; |
| 412 | /* silent return to keep pcm code cleaner */ |
| 413 | |
| 414 | if (!pm_qos_request_active(req)) { |
| 415 | WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n"); |
| 416 | return; |
| 417 | } |
| 418 | |
| 419 | if (delayed_work_pending(&req->work)) |
| 420 | cancel_delayed_work_sync(&req->work); |
| 421 | |
| 422 | pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, |
| 423 | &req->node, PM_QOS_REMOVE_REQ, |
| 424 | PM_QOS_DEFAULT_VALUE); |
| 425 | memset(req, 0, sizeof(*req)); |
| 426 | } |
| 427 | EXPORT_SYMBOL_GPL(pm_qos_remove_request); |
| 428 | |
| 429 | /** |
| 430 | * pm_qos_add_notifier - sets notification entry for changes to target value |
| 431 | * @pm_qos_class: identifies which qos target changes should be notified. |
| 432 | * @notifier: notifier block managed by caller. |
| 433 | * |
| 434 | * will register the notifier into a notification chain that gets called |
| 435 | * upon changes to the pm_qos_class target value. |
| 436 | */ |
| 437 | int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) |
| 438 | { |
| 439 | int retval; |
| 440 | |
| 441 | retval = blocking_notifier_chain_register( |
| 442 | pm_qos_array[pm_qos_class]->constraints->notifiers, |
| 443 | notifier); |
| 444 | |
| 445 | return retval; |
| 446 | } |
| 447 | EXPORT_SYMBOL_GPL(pm_qos_add_notifier); |
| 448 | |
| 449 | /** |
| 450 | * pm_qos_remove_notifier - deletes notification entry from chain. |
| 451 | * @pm_qos_class: identifies which qos target changes are notified. |
| 452 | * @notifier: notifier block to be removed. |
| 453 | * |
| 454 | * will remove the notifier from the notification chain that gets called |
| 455 | * upon changes to the pm_qos_class target value. |
| 456 | */ |
| 457 | int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) |
| 458 | { |
| 459 | int retval; |
| 460 | |
| 461 | retval = blocking_notifier_chain_unregister( |
| 462 | pm_qos_array[pm_qos_class]->constraints->notifiers, |
| 463 | notifier); |
| 464 | |
| 465 | return retval; |
| 466 | } |
| 467 | EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); |
| 468 | |
| 469 | /* User space interface to PM QoS classes via misc devices */ |
| 470 | static int register_pm_qos_misc(struct pm_qos_object *qos) |
| 471 | { |
| 472 | qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR; |
| 473 | qos->pm_qos_power_miscdev.name = qos->name; |
| 474 | qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops; |
| 475 | |
| 476 | return misc_register(&qos->pm_qos_power_miscdev); |
| 477 | } |
| 478 | |
| 479 | static int find_pm_qos_object_by_minor(int minor) |
| 480 | { |
| 481 | int pm_qos_class; |
| 482 | |
| 483 | for (pm_qos_class = 0; |
| 484 | pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) { |
| 485 | if (minor == |
| 486 | pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor) |
| 487 | return pm_qos_class; |
| 488 | } |
| 489 | return -1; |
| 490 | } |
| 491 | |
| 492 | static int pm_qos_power_open(struct inode *inode, struct file *filp) |
| 493 | { |
| 494 | long pm_qos_class; |
| 495 | |
| 496 | pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); |
| 497 | if (pm_qos_class >= 0) { |
| 498 | struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL); |
| 499 | if (!req) |
| 500 | return -ENOMEM; |
| 501 | |
| 502 | pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE); |
| 503 | filp->private_data = req; |
| 504 | |
| 505 | return 0; |
| 506 | } |
| 507 | return -EPERM; |
| 508 | } |
| 509 | |
| 510 | static int pm_qos_power_release(struct inode *inode, struct file *filp) |
| 511 | { |
| 512 | struct pm_qos_request *req; |
| 513 | |
| 514 | req = filp->private_data; |
| 515 | pm_qos_remove_request(req); |
| 516 | kfree(req); |
| 517 | |
| 518 | return 0; |
| 519 | } |
| 520 | |
| 521 | |
| 522 | static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, |
| 523 | size_t count, loff_t *f_pos) |
| 524 | { |
| 525 | s32 value; |
| 526 | unsigned long flags; |
| 527 | struct pm_qos_request *req = filp->private_data; |
| 528 | |
| 529 | if (!req) |
| 530 | return -EINVAL; |
| 531 | if (!pm_qos_request_active(req)) |
| 532 | return -EINVAL; |
| 533 | |
| 534 | spin_lock_irqsave(&pm_qos_lock, flags); |
| 535 | value = pm_qos_get_value(pm_qos_array[req->pm_qos_class]->constraints); |
| 536 | spin_unlock_irqrestore(&pm_qos_lock, flags); |
| 537 | |
| 538 | return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32)); |
| 539 | } |
| 540 | |
| 541 | static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, |
| 542 | size_t count, loff_t *f_pos) |
| 543 | { |
| 544 | s32 value; |
| 545 | struct pm_qos_request *req; |
| 546 | |
| 547 | if (count == sizeof(s32)) { |
| 548 | if (copy_from_user(&value, buf, sizeof(s32))) |
| 549 | return -EFAULT; |
| 550 | } else if (count <= 11) { /* ASCII perhaps? */ |
| 551 | char ascii_value[11]; |
| 552 | unsigned long int ulval; |
| 553 | int ret; |
| 554 | |
| 555 | if (copy_from_user(ascii_value, buf, count)) |
| 556 | return -EFAULT; |
| 557 | |
| 558 | if (count > 10) { |
| 559 | if (ascii_value[10] == '\n') |
| 560 | ascii_value[10] = '\0'; |
| 561 | else |
| 562 | return -EINVAL; |
| 563 | } else { |
| 564 | ascii_value[count] = '\0'; |
| 565 | } |
| 566 | ret = kstrtoul(ascii_value, 16, &ulval); |
| 567 | if (ret) { |
| 568 | pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret); |
| 569 | return -EINVAL; |
| 570 | } |
| 571 | value = (s32)lower_32_bits(ulval); |
| 572 | } else { |
| 573 | return -EINVAL; |
| 574 | } |
| 575 | |
| 576 | req = filp->private_data; |
| 577 | pm_qos_update_request(req, value); |
| 578 | |
| 579 | return count; |
| 580 | } |
| 581 | |
| 582 | |
| 583 | static int __init pm_qos_power_init(void) |
| 584 | { |
| 585 | int ret = 0; |
| 586 | int i; |
| 587 | |
| 588 | BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES); |
| 589 | |
| 590 | for (i = 1; i < PM_QOS_NUM_CLASSES; i++) { |
| 591 | ret = register_pm_qos_misc(pm_qos_array[i]); |
| 592 | if (ret < 0) { |
| 593 | printk(KERN_ERR "pm_qos_param: %s setup failed\n", |
| 594 | pm_qos_array[i]->name); |
| 595 | return ret; |
| 596 | } |
| 597 | } |
| 598 | |
| 599 | return ret; |
| 600 | } |
| 601 | |
| 602 | late_initcall(pm_qos_power_init); |