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Mark Grossd82b3512008-02-04 22:30:08 -08001/*
2 * This module exposes the interface to kernel space for specifying
3 * QoS dependencies. It provides infrastructure for registration of:
4 *
Mark Grossed771342010-05-06 01:59:26 +02005 * Dependents on a QoS value : register requests
Mark Grossd82b3512008-02-04 22:30:08 -08006 * 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 *
Mark Grossed771342010-05-06 01:59:26 +020017 * There are lists of pm_qos_objects each one wrapping requests, notifiers
Mark Grossd82b3512008-02-04 22:30:08 -080018 *
Mark Grossed771342010-05-06 01:59:26 +020019 * User mode requests on a QOS parameter register themselves to the
Mark Grossd82b3512008-02-04 22:30:08 -080020 * 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
Mark Grossed771342010-05-06 01:59:26 +020023 * 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
Mark Grossd82b3512008-02-04 22:30:08 -080025 * pointer or exits the pm_qos_object will get an opportunity to clean up.
26 *
Richard Hughesbf1db692008-08-05 13:01:35 -070027 * Mark Gross <mgross@linux.intel.com>
Mark Grossd82b3512008-02-04 22:30:08 -080028 */
29
Mark Grossed771342010-05-06 01:59:26 +020030/*#define DEBUG*/
31
Jean Pihete8db0be2011-08-25 15:35:03 +020032#include <linux/pm_qos.h>
Mark Grossd82b3512008-02-04 22:30:08 -080033#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>
Rafael J. Wysocki0775a602011-05-27 00:05:23 +020043#include <linux/kernel.h>
Mark Grossd82b3512008-02-04 22:30:08 -080044
45#include <linux/uaccess.h>
Paul Gortmaker6e5fdee2011-05-26 16:00:52 -040046#include <linux/export.h>
Sahara247e9ee2013-06-21 11:12:28 +090047#include <trace/events/power.h>
Mark Grossd82b3512008-02-04 22:30:08 -080048
49/*
Jean Pihetcc749982011-08-25 15:35:12 +020050 * locking rule: all changes to constraints or notifiers lists
Mark Grossd82b3512008-02-04 22:30:08 -080051 * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock
52 * held, taken with _irqsave. One lock to rule them all
53 */
Mark Grossd82b3512008-02-04 22:30:08 -080054struct pm_qos_object {
Jean Pihet4e1779b2011-08-25 15:35:27 +020055 struct pm_qos_constraints *constraints;
Mark Grossd82b3512008-02-04 22:30:08 -080056 struct miscdevice pm_qos_power_miscdev;
57 char *name;
Mark Grossd82b3512008-02-04 22:30:08 -080058};
59
James Bottomley5f279842010-07-19 02:00:18 +020060static DEFINE_SPINLOCK(pm_qos_lock);
61
Mark Grossd82b3512008-02-04 22:30:08 -080062static struct pm_qos_object null_pm_qos;
Jean Pihet4e1779b2011-08-25 15:35:27 +020063
Mark Grossd82b3512008-02-04 22:30:08 -080064static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier);
Jean Pihet4e1779b2011-08-25 15:35:27 +020065static struct pm_qos_constraints cpu_dma_constraints = {
66 .list = PLIST_HEAD_INIT(cpu_dma_constraints.list),
Tim Chen333c5ae2011-02-11 12:49:04 -080067 .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
68 .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
James Bottomley5f279842010-07-19 02:00:18 +020069 .type = PM_QOS_MIN,
Jean Pihet4e1779b2011-08-25 15:35:27 +020070 .notifiers = &cpu_dma_lat_notifier,
71};
72static struct pm_qos_object cpu_dma_pm_qos = {
73 .constraints = &cpu_dma_constraints,
Dominik Brodowskia6f05b972011-11-06 21:54:12 +010074 .name = "cpu_dma_latency",
Mark Grossd82b3512008-02-04 22:30:08 -080075};
76
77static BLOCKING_NOTIFIER_HEAD(network_lat_notifier);
Jean Pihet4e1779b2011-08-25 15:35:27 +020078static struct pm_qos_constraints network_lat_constraints = {
79 .list = PLIST_HEAD_INIT(network_lat_constraints.list),
Tim Chen333c5ae2011-02-11 12:49:04 -080080 .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
81 .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
Jean Pihet4e1779b2011-08-25 15:35:27 +020082 .type = PM_QOS_MIN,
83 .notifiers = &network_lat_notifier,
84};
85static struct pm_qos_object network_lat_pm_qos = {
86 .constraints = &network_lat_constraints,
87 .name = "network_latency",
Mark Grossd82b3512008-02-04 22:30:08 -080088};
89
90
91static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier);
Jean Pihet4e1779b2011-08-25 15:35:27 +020092static struct pm_qos_constraints network_tput_constraints = {
93 .list = PLIST_HEAD_INIT(network_tput_constraints.list),
Tim Chen333c5ae2011-02-11 12:49:04 -080094 .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
95 .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
James Bottomley5f279842010-07-19 02:00:18 +020096 .type = PM_QOS_MAX,
Jean Pihet4e1779b2011-08-25 15:35:27 +020097 .notifiers = &network_throughput_notifier,
98};
99static struct pm_qos_object network_throughput_pm_qos = {
100 .constraints = &network_tput_constraints,
101 .name = "network_throughput",
Mark Grossd82b3512008-02-04 22:30:08 -0800102};
103
104
105static struct pm_qos_object *pm_qos_array[] = {
106 &null_pm_qos,
107 &cpu_dma_pm_qos,
108 &network_lat_pm_qos,
109 &network_throughput_pm_qos
110};
111
Mark Grossd82b3512008-02-04 22:30:08 -0800112static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
113 size_t count, loff_t *f_pos);
Thomas Renningerf9b9e802011-02-28 22:06:34 +0100114static ssize_t pm_qos_power_read(struct file *filp, char __user *buf,
115 size_t count, loff_t *f_pos);
Mark Grossd82b3512008-02-04 22:30:08 -0800116static int pm_qos_power_open(struct inode *inode, struct file *filp);
117static int pm_qos_power_release(struct inode *inode, struct file *filp);
118
119static const struct file_operations pm_qos_power_fops = {
120 .write = pm_qos_power_write,
Thomas Renningerf9b9e802011-02-28 22:06:34 +0100121 .read = pm_qos_power_read,
Mark Grossd82b3512008-02-04 22:30:08 -0800122 .open = pm_qos_power_open,
123 .release = pm_qos_power_release,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200124 .llseek = noop_llseek,
Mark Grossd82b3512008-02-04 22:30:08 -0800125};
126
James Bottomley5f279842010-07-19 02:00:18 +0200127/* unlocked internal variant */
Jean Pihetabe98ec2011-08-25 15:35:34 +0200128static inline int pm_qos_get_value(struct pm_qos_constraints *c)
Mark Grossd82b3512008-02-04 22:30:08 -0800129{
Jean Pihetabe98ec2011-08-25 15:35:34 +0200130 if (plist_head_empty(&c->list))
131 return c->default_value;
James Bottomley5f279842010-07-19 02:00:18 +0200132
Jean Pihetabe98ec2011-08-25 15:35:34 +0200133 switch (c->type) {
James Bottomley5f279842010-07-19 02:00:18 +0200134 case PM_QOS_MIN:
Jean Pihetabe98ec2011-08-25 15:35:34 +0200135 return plist_first(&c->list)->prio;
James Bottomley5f279842010-07-19 02:00:18 +0200136
137 case PM_QOS_MAX:
Jean Pihetabe98ec2011-08-25 15:35:34 +0200138 return plist_last(&c->list)->prio;
James Bottomley5f279842010-07-19 02:00:18 +0200139
140 default:
141 /* runtime check for not using enum */
142 BUG();
Luis Gonzalez Fernandezc6a57bf2012-09-07 21:35:21 +0200143 return PM_QOS_DEFAULT_VALUE;
James Bottomley5f279842010-07-19 02:00:18 +0200144 }
Mark Grossd82b3512008-02-04 22:30:08 -0800145}
146
Jean Pihetb66213c2011-08-25 15:35:47 +0200147s32 pm_qos_read_value(struct pm_qos_constraints *c)
Tim Chen333c5ae2011-02-11 12:49:04 -0800148{
Jean Pihetabe98ec2011-08-25 15:35:34 +0200149 return c->target_value;
Tim Chen333c5ae2011-02-11 12:49:04 -0800150}
151
Jean Pihetabe98ec2011-08-25 15:35:34 +0200152static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value)
Tim Chen333c5ae2011-02-11 12:49:04 -0800153{
Jean Pihetabe98ec2011-08-25 15:35:34 +0200154 c->target_value = value;
Tim Chen333c5ae2011-02-11 12:49:04 -0800155}
156
Jean Pihetabe98ec2011-08-25 15:35:34 +0200157/**
158 * pm_qos_update_target - manages the constraints list and calls the notifiers
159 * if needed
160 * @c: constraints data struct
161 * @node: request to add to the list, to update or to remove
162 * @action: action to take on the constraints list
163 * @value: value of the request to add or update
164 *
165 * This function returns 1 if the aggregated constraint value has changed, 0
166 * otherwise.
167 */
168int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
169 enum pm_qos_req_action action, int value)
Mark Grossd82b3512008-02-04 22:30:08 -0800170{
Mark Grossd82b3512008-02-04 22:30:08 -0800171 unsigned long flags;
Jean Pihetabe98ec2011-08-25 15:35:34 +0200172 int prev_value, curr_value, new_value;
Mark Grossd82b3512008-02-04 22:30:08 -0800173
174 spin_lock_irqsave(&pm_qos_lock, flags);
Jean Pihetabe98ec2011-08-25 15:35:34 +0200175 prev_value = pm_qos_get_value(c);
176 if (value == PM_QOS_DEFAULT_VALUE)
177 new_value = c->default_value;
178 else
179 new_value = value;
180
181 switch (action) {
182 case PM_QOS_REMOVE_REQ:
183 plist_del(node, &c->list);
184 break;
185 case PM_QOS_UPDATE_REQ:
James Bottomley5f279842010-07-19 02:00:18 +0200186 /*
187 * to change the list, we atomically remove, reinit
188 * with new value and add, then see if the extremal
189 * changed
190 */
Jean Pihetabe98ec2011-08-25 15:35:34 +0200191 plist_del(node, &c->list);
192 case PM_QOS_ADD_REQ:
193 plist_node_init(node, new_value);
194 plist_add(node, &c->list);
195 break;
196 default:
197 /* no action */
198 ;
Mark Grossd82b3512008-02-04 22:30:08 -0800199 }
Jean Pihetabe98ec2011-08-25 15:35:34 +0200200
201 curr_value = pm_qos_get_value(c);
202 pm_qos_set_value(c, curr_value);
203
Mark Grossd82b3512008-02-04 22:30:08 -0800204 spin_unlock_irqrestore(&pm_qos_lock, flags);
205
Sahara247e9ee2013-06-21 11:12:28 +0900206 trace_pm_qos_update_target(action, prev_value, curr_value);
Jean Pihetabe98ec2011-08-25 15:35:34 +0200207 if (prev_value != curr_value) {
208 blocking_notifier_call_chain(c->notifiers,
James Bottomley5f279842010-07-19 02:00:18 +0200209 (unsigned long)curr_value,
210 NULL);
Jean Pihetabe98ec2011-08-25 15:35:34 +0200211 return 1;
212 } else {
213 return 0;
214 }
Mark Grossd82b3512008-02-04 22:30:08 -0800215}
216
Mark Grossd82b3512008-02-04 22:30:08 -0800217/**
Rafael J. Wysocki5efbe422012-10-23 01:07:46 +0200218 * pm_qos_flags_remove_req - Remove device PM QoS flags request.
219 * @pqf: Device PM QoS flags set to remove the request from.
220 * @req: Request to remove from the set.
221 */
222static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf,
223 struct pm_qos_flags_request *req)
224{
225 s32 val = 0;
226
227 list_del(&req->node);
228 list_for_each_entry(req, &pqf->list, node)
229 val |= req->flags;
230
231 pqf->effective_flags = val;
232}
233
234/**
235 * pm_qos_update_flags - Update a set of PM QoS flags.
236 * @pqf: Set of flags to update.
237 * @req: Request to add to the set, to modify, or to remove from the set.
238 * @action: Action to take on the set.
239 * @val: Value of the request to add or modify.
240 *
241 * Update the given set of PM QoS flags and call notifiers if the aggregate
242 * value has changed. Returns 1 if the aggregate constraint value has changed,
243 * 0 otherwise.
244 */
245bool pm_qos_update_flags(struct pm_qos_flags *pqf,
246 struct pm_qos_flags_request *req,
247 enum pm_qos_req_action action, s32 val)
248{
249 unsigned long irqflags;
250 s32 prev_value, curr_value;
251
252 spin_lock_irqsave(&pm_qos_lock, irqflags);
253
254 prev_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
255
256 switch (action) {
257 case PM_QOS_REMOVE_REQ:
258 pm_qos_flags_remove_req(pqf, req);
259 break;
260 case PM_QOS_UPDATE_REQ:
261 pm_qos_flags_remove_req(pqf, req);
262 case PM_QOS_ADD_REQ:
263 req->flags = val;
264 INIT_LIST_HEAD(&req->node);
265 list_add_tail(&req->node, &pqf->list);
266 pqf->effective_flags |= val;
267 break;
268 default:
269 /* no action */
270 ;
271 }
272
273 curr_value = list_empty(&pqf->list) ? 0 : pqf->effective_flags;
274
275 spin_unlock_irqrestore(&pm_qos_lock, irqflags);
276
Sahara247e9ee2013-06-21 11:12:28 +0900277 trace_pm_qos_update_flags(action, prev_value, curr_value);
Rafael J. Wysocki5efbe422012-10-23 01:07:46 +0200278 return prev_value != curr_value;
279}
280
281/**
Mark Grossed771342010-05-06 01:59:26 +0200282 * pm_qos_request - returns current system wide qos expectation
Mark Grossd82b3512008-02-04 22:30:08 -0800283 * @pm_qos_class: identification of which qos value is requested
284 *
Tim Chen333c5ae2011-02-11 12:49:04 -0800285 * This function returns the current target value.
Mark Grossd82b3512008-02-04 22:30:08 -0800286 */
Mark Grossed771342010-05-06 01:59:26 +0200287int pm_qos_request(int pm_qos_class)
Mark Grossd82b3512008-02-04 22:30:08 -0800288{
Jean Pihetabe98ec2011-08-25 15:35:34 +0200289 return pm_qos_read_value(pm_qos_array[pm_qos_class]->constraints);
Mark Grossd82b3512008-02-04 22:30:08 -0800290}
Mark Grossed771342010-05-06 01:59:26 +0200291EXPORT_SYMBOL_GPL(pm_qos_request);
Mark Grossd82b3512008-02-04 22:30:08 -0800292
Jean Pihetcc749982011-08-25 15:35:12 +0200293int pm_qos_request_active(struct pm_qos_request *req)
James Bottomley82f68252010-07-05 22:53:06 +0200294{
295 return req->pm_qos_class != 0;
296}
297EXPORT_SYMBOL_GPL(pm_qos_request_active);
298
Stephen Boyd40fea92f2013-08-13 14:12:40 -0700299static void __pm_qos_update_request(struct pm_qos_request *req,
300 s32 new_value)
301{
302 trace_pm_qos_update_request(req->pm_qos_class, new_value);
303
304 if (new_value != req->node.prio)
305 pm_qos_update_target(
306 pm_qos_array[req->pm_qos_class]->constraints,
307 &req->node, PM_QOS_UPDATE_REQ, new_value);
308}
309
Mark Grossd82b3512008-02-04 22:30:08 -0800310/**
MyungJoo Hamc4772d12012-03-28 23:31:24 +0200311 * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout
312 * @work: work struct for the delayed work (timeout)
313 *
314 * This cancels the timeout request by falling back to the default at timeout.
315 */
316static void pm_qos_work_fn(struct work_struct *work)
317{
318 struct pm_qos_request *req = container_of(to_delayed_work(work),
319 struct pm_qos_request,
320 work);
321
Stephen Boyd40fea92f2013-08-13 14:12:40 -0700322 __pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE);
MyungJoo Hamc4772d12012-03-28 23:31:24 +0200323}
324
325/**
Mark Grossed771342010-05-06 01:59:26 +0200326 * pm_qos_add_request - inserts new qos request into the list
Jean Pihetcc749982011-08-25 15:35:12 +0200327 * @req: pointer to a preallocated handle
Saravana Kannan25cc69e2010-08-26 20:18:43 +0200328 * @pm_qos_class: identifies which list of qos request to use
Mark Grossd82b3512008-02-04 22:30:08 -0800329 * @value: defines the qos request
330 *
331 * This function inserts a new entry in the pm_qos_class list of requested qos
Richard Hughesbf1db692008-08-05 13:01:35 -0700332 * performance characteristics. It recomputes the aggregate QoS expectations
Jean Pihetcc749982011-08-25 15:35:12 +0200333 * for the pm_qos_class of parameters and initializes the pm_qos_request
Saravana Kannan25cc69e2010-08-26 20:18:43 +0200334 * handle. Caller needs to save this handle for later use in updates and
335 * removal.
Mark Grossd82b3512008-02-04 22:30:08 -0800336 */
Saravana Kannan25cc69e2010-08-26 20:18:43 +0200337
Jean Pihetcc749982011-08-25 15:35:12 +0200338void pm_qos_add_request(struct pm_qos_request *req,
James Bottomley82f68252010-07-05 22:53:06 +0200339 int pm_qos_class, s32 value)
Mark Grossd82b3512008-02-04 22:30:08 -0800340{
Jean Pihetabe98ec2011-08-25 15:35:34 +0200341 if (!req) /*guard against callers passing in null */
342 return;
Mark Grossd82b3512008-02-04 22:30:08 -0800343
Jean Pihetcc749982011-08-25 15:35:12 +0200344 if (pm_qos_request_active(req)) {
James Bottomley82f68252010-07-05 22:53:06 +0200345 WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n");
346 return;
Mark Grossd82b3512008-02-04 22:30:08 -0800347 }
Jean Pihetcc749982011-08-25 15:35:12 +0200348 req->pm_qos_class = pm_qos_class;
MyungJoo Hamc4772d12012-03-28 23:31:24 +0200349 INIT_DELAYED_WORK(&req->work, pm_qos_work_fn);
Saharaae8822b2013-06-21 11:12:29 +0900350 trace_pm_qos_add_request(pm_qos_class, value);
Jean Pihetabe98ec2011-08-25 15:35:34 +0200351 pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints,
352 &req->node, PM_QOS_ADD_REQ, value);
Mark Grossd82b3512008-02-04 22:30:08 -0800353}
Mark Grossed771342010-05-06 01:59:26 +0200354EXPORT_SYMBOL_GPL(pm_qos_add_request);
Mark Grossd82b3512008-02-04 22:30:08 -0800355
356/**
Mark Grossed771342010-05-06 01:59:26 +0200357 * pm_qos_update_request - modifies an existing qos request
Jean Pihetcc749982011-08-25 15:35:12 +0200358 * @req : handle to list element holding a pm_qos request to use
Mark Grossd82b3512008-02-04 22:30:08 -0800359 * @value: defines the qos request
360 *
Mark Grossed771342010-05-06 01:59:26 +0200361 * Updates an existing qos request for the pm_qos_class of parameters along
Mark Grossd82b3512008-02-04 22:30:08 -0800362 * with updating the target pm_qos_class value.
363 *
Mark Grossed771342010-05-06 01:59:26 +0200364 * Attempts are made to make this code callable on hot code paths.
Mark Grossd82b3512008-02-04 22:30:08 -0800365 */
Jean Pihetcc749982011-08-25 15:35:12 +0200366void pm_qos_update_request(struct pm_qos_request *req,
James Bottomley5f279842010-07-19 02:00:18 +0200367 s32 new_value)
Mark Grossd82b3512008-02-04 22:30:08 -0800368{
Jean Pihetcc749982011-08-25 15:35:12 +0200369 if (!req) /*guard against callers passing in null */
James Bottomley5f279842010-07-19 02:00:18 +0200370 return;
Mark Grossed771342010-05-06 01:59:26 +0200371
Jean Pihetcc749982011-08-25 15:35:12 +0200372 if (!pm_qos_request_active(req)) {
James Bottomley82f68252010-07-05 22:53:06 +0200373 WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n");
374 return;
375 }
376
Tejun Heoed1ac6e2013-01-11 13:37:33 +0100377 cancel_delayed_work_sync(&req->work);
Stephen Boyd40fea92f2013-08-13 14:12:40 -0700378 __pm_qos_update_request(req, new_value);
Mark Grossd82b3512008-02-04 22:30:08 -0800379}
Mark Grossed771342010-05-06 01:59:26 +0200380EXPORT_SYMBOL_GPL(pm_qos_update_request);
Mark Grossd82b3512008-02-04 22:30:08 -0800381
382/**
MyungJoo Hamc4772d12012-03-28 23:31:24 +0200383 * pm_qos_update_request_timeout - modifies an existing qos request temporarily.
384 * @req : handle to list element holding a pm_qos request to use
385 * @new_value: defines the temporal qos request
386 * @timeout_us: the effective duration of this qos request in usecs.
387 *
388 * After timeout_us, this qos request is cancelled automatically.
389 */
390void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value,
391 unsigned long timeout_us)
392{
393 if (!req)
394 return;
395 if (WARN(!pm_qos_request_active(req),
396 "%s called for unknown object.", __func__))
397 return;
398
Tejun Heoed1ac6e2013-01-11 13:37:33 +0100399 cancel_delayed_work_sync(&req->work);
MyungJoo Hamc4772d12012-03-28 23:31:24 +0200400
Saharaae8822b2013-06-21 11:12:29 +0900401 trace_pm_qos_update_request_timeout(req->pm_qos_class,
402 new_value, timeout_us);
MyungJoo Hamc4772d12012-03-28 23:31:24 +0200403 if (new_value != req->node.prio)
404 pm_qos_update_target(
405 pm_qos_array[req->pm_qos_class]->constraints,
406 &req->node, PM_QOS_UPDATE_REQ, new_value);
407
408 schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us));
409}
410
411/**
Mark Grossed771342010-05-06 01:59:26 +0200412 * pm_qos_remove_request - modifies an existing qos request
Jean Pihetcc749982011-08-25 15:35:12 +0200413 * @req: handle to request list element
Mark Grossd82b3512008-02-04 22:30:08 -0800414 *
Jean Pihetcc749982011-08-25 15:35:12 +0200415 * Will remove pm qos request from the list of constraints and
Mark Grossed771342010-05-06 01:59:26 +0200416 * recompute the current target value for the pm_qos_class. Call this
417 * on slow code paths.
Mark Grossd82b3512008-02-04 22:30:08 -0800418 */
Jean Pihetcc749982011-08-25 15:35:12 +0200419void pm_qos_remove_request(struct pm_qos_request *req)
Mark Grossd82b3512008-02-04 22:30:08 -0800420{
Jean Pihetabe98ec2011-08-25 15:35:34 +0200421 if (!req) /*guard against callers passing in null */
Mark Grossed771342010-05-06 01:59:26 +0200422 return;
423 /* silent return to keep pcm code cleaner */
424
Jean Pihetcc749982011-08-25 15:35:12 +0200425 if (!pm_qos_request_active(req)) {
James Bottomley82f68252010-07-05 22:53:06 +0200426 WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n");
427 return;
428 }
429
Tejun Heoed1ac6e2013-01-11 13:37:33 +0100430 cancel_delayed_work_sync(&req->work);
MyungJoo Hamc4772d12012-03-28 23:31:24 +0200431
Saharaae8822b2013-06-21 11:12:29 +0900432 trace_pm_qos_remove_request(req->pm_qos_class, PM_QOS_DEFAULT_VALUE);
Jean Pihetabe98ec2011-08-25 15:35:34 +0200433 pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints,
434 &req->node, PM_QOS_REMOVE_REQ,
435 PM_QOS_DEFAULT_VALUE);
Jean Pihetcc749982011-08-25 15:35:12 +0200436 memset(req, 0, sizeof(*req));
Mark Grossd82b3512008-02-04 22:30:08 -0800437}
Mark Grossed771342010-05-06 01:59:26 +0200438EXPORT_SYMBOL_GPL(pm_qos_remove_request);
Mark Grossd82b3512008-02-04 22:30:08 -0800439
440/**
441 * pm_qos_add_notifier - sets notification entry for changes to target value
442 * @pm_qos_class: identifies which qos target changes should be notified.
443 * @notifier: notifier block managed by caller.
444 *
445 * will register the notifier into a notification chain that gets called
Richard Hughesbf1db692008-08-05 13:01:35 -0700446 * upon changes to the pm_qos_class target value.
Mark Grossd82b3512008-02-04 22:30:08 -0800447 */
Mark Grossed771342010-05-06 01:59:26 +0200448int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier)
Mark Grossd82b3512008-02-04 22:30:08 -0800449{
450 int retval;
451
452 retval = blocking_notifier_chain_register(
Jean Pihet4e1779b2011-08-25 15:35:27 +0200453 pm_qos_array[pm_qos_class]->constraints->notifiers,
454 notifier);
Mark Grossd82b3512008-02-04 22:30:08 -0800455
456 return retval;
457}
458EXPORT_SYMBOL_GPL(pm_qos_add_notifier);
459
460/**
461 * pm_qos_remove_notifier - deletes notification entry from chain.
462 * @pm_qos_class: identifies which qos target changes are notified.
463 * @notifier: notifier block to be removed.
464 *
465 * will remove the notifier from the notification chain that gets called
Richard Hughesbf1db692008-08-05 13:01:35 -0700466 * upon changes to the pm_qos_class target value.
Mark Grossd82b3512008-02-04 22:30:08 -0800467 */
468int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
469{
470 int retval;
471
472 retval = blocking_notifier_chain_unregister(
Jean Pihet4e1779b2011-08-25 15:35:27 +0200473 pm_qos_array[pm_qos_class]->constraints->notifiers,
474 notifier);
Mark Grossd82b3512008-02-04 22:30:08 -0800475
476 return retval;
477}
478EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);
479
Jean Pihet4a31a332011-08-25 15:35:20 +0200480/* User space interface to PM QoS classes via misc devices */
481static int register_pm_qos_misc(struct pm_qos_object *qos)
482{
483 qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR;
484 qos->pm_qos_power_miscdev.name = qos->name;
485 qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops;
486
487 return misc_register(&qos->pm_qos_power_miscdev);
488}
489
490static int find_pm_qos_object_by_minor(int minor)
491{
492 int pm_qos_class;
493
Saharad24c2a42013-06-20 11:33:57 +0900494 for (pm_qos_class = PM_QOS_CPU_DMA_LATENCY;
Jean Pihet4a31a332011-08-25 15:35:20 +0200495 pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) {
496 if (minor ==
497 pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor)
498 return pm_qos_class;
499 }
500 return -1;
501}
502
Mark Grossd82b3512008-02-04 22:30:08 -0800503static int pm_qos_power_open(struct inode *inode, struct file *filp)
504{
Mark Grossd82b3512008-02-04 22:30:08 -0800505 long pm_qos_class;
506
507 pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
Saharad24c2a42013-06-20 11:33:57 +0900508 if (pm_qos_class >= PM_QOS_CPU_DMA_LATENCY) {
Jean Pihetcc749982011-08-25 15:35:12 +0200509 struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL);
James Bottomley82f68252010-07-05 22:53:06 +0200510 if (!req)
511 return -ENOMEM;
512
513 pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE);
514 filp->private_data = req;
Mark Grossed771342010-05-06 01:59:26 +0200515
Guennadi Liakhovetski6513fd62011-11-03 10:12:36 +0100516 return 0;
Mark Grossd82b3512008-02-04 22:30:08 -0800517 }
Mark Grossd82b3512008-02-04 22:30:08 -0800518 return -EPERM;
519}
520
521static int pm_qos_power_release(struct inode *inode, struct file *filp)
522{
Jean Pihetcc749982011-08-25 15:35:12 +0200523 struct pm_qos_request *req;
Mark Grossd82b3512008-02-04 22:30:08 -0800524
James Bottomley82f68252010-07-05 22:53:06 +0200525 req = filp->private_data;
Mark Grossed771342010-05-06 01:59:26 +0200526 pm_qos_remove_request(req);
James Bottomley82f68252010-07-05 22:53:06 +0200527 kfree(req);
Mark Grossd82b3512008-02-04 22:30:08 -0800528
529 return 0;
530}
531
Mark Grossed771342010-05-06 01:59:26 +0200532
Thomas Renningerf9b9e802011-02-28 22:06:34 +0100533static ssize_t pm_qos_power_read(struct file *filp, char __user *buf,
534 size_t count, loff_t *f_pos)
535{
536 s32 value;
537 unsigned long flags;
Jean Pihetcc749982011-08-25 15:35:12 +0200538 struct pm_qos_request *req = filp->private_data;
Thomas Renningerf9b9e802011-02-28 22:06:34 +0100539
Jean Pihetcc749982011-08-25 15:35:12 +0200540 if (!req)
Thomas Renningerf9b9e802011-02-28 22:06:34 +0100541 return -EINVAL;
Jean Pihetcc749982011-08-25 15:35:12 +0200542 if (!pm_qos_request_active(req))
Thomas Renningerf9b9e802011-02-28 22:06:34 +0100543 return -EINVAL;
544
Thomas Renningerf9b9e802011-02-28 22:06:34 +0100545 spin_lock_irqsave(&pm_qos_lock, flags);
Jean Pihetabe98ec2011-08-25 15:35:34 +0200546 value = pm_qos_get_value(pm_qos_array[req->pm_qos_class]->constraints);
Thomas Renningerf9b9e802011-02-28 22:06:34 +0100547 spin_unlock_irqrestore(&pm_qos_lock, flags);
548
549 return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32));
550}
551
Mark Grossd82b3512008-02-04 22:30:08 -0800552static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
553 size_t count, loff_t *f_pos)
554{
555 s32 value;
Jean Pihetcc749982011-08-25 15:35:12 +0200556 struct pm_qos_request *req;
Mark Grossd82b3512008-02-04 22:30:08 -0800557
Mark Grossed771342010-05-06 01:59:26 +0200558 if (count == sizeof(s32)) {
559 if (copy_from_user(&value, buf, sizeof(s32)))
560 return -EFAULT;
Rafael J. Wysocki0775a602011-05-27 00:05:23 +0200561 } else if (count <= 11) { /* ASCII perhaps? */
562 char ascii_value[11];
563 unsigned long int ulval;
564 int ret;
565
566 if (copy_from_user(ascii_value, buf, count))
Mark Grossed771342010-05-06 01:59:26 +0200567 return -EFAULT;
Rafael J. Wysocki0775a602011-05-27 00:05:23 +0200568
569 if (count > 10) {
570 if (ascii_value[10] == '\n')
571 ascii_value[10] = '\0';
572 else
573 return -EINVAL;
574 } else {
575 ascii_value[count] = '\0';
576 }
Daniel Walter883ee4f2012-10-23 01:20:35 +0200577 ret = kstrtoul(ascii_value, 16, &ulval);
Rafael J. Wysocki0775a602011-05-27 00:05:23 +0200578 if (ret) {
579 pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret);
mark gross0109c2c2010-09-09 23:20:09 +0200580 return -EINVAL;
Rafael J. Wysocki0775a602011-05-27 00:05:23 +0200581 }
582 value = (s32)lower_32_bits(ulval);
583 } else {
Mark Grossd82b3512008-02-04 22:30:08 -0800584 return -EINVAL;
Rafael J. Wysocki0775a602011-05-27 00:05:23 +0200585 }
Mark Grossd82b3512008-02-04 22:30:08 -0800586
Jean Pihetcc749982011-08-25 15:35:12 +0200587 req = filp->private_data;
588 pm_qos_update_request(req, value);
Mark Grossed771342010-05-06 01:59:26 +0200589
590 return count;
Mark Grossd82b3512008-02-04 22:30:08 -0800591}
592
593
594static int __init pm_qos_power_init(void)
595{
596 int ret = 0;
Alex Fridd031e1d2012-01-29 20:39:25 +0100597 int i;
Mark Grossd82b3512008-02-04 22:30:08 -0800598
Alex Fridd031e1d2012-01-29 20:39:25 +0100599 BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES);
600
Saharad24c2a42013-06-20 11:33:57 +0900601 for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) {
Alex Fridd031e1d2012-01-29 20:39:25 +0100602 ret = register_pm_qos_misc(pm_qos_array[i]);
603 if (ret < 0) {
604 printk(KERN_ERR "pm_qos_param: %s setup failed\n",
605 pm_qos_array[i]->name);
606 return ret;
607 }
Mark Grossd82b3512008-02-04 22:30:08 -0800608 }
Mark Grossd82b3512008-02-04 22:30:08 -0800609
610 return ret;
611}
612
613late_initcall(pm_qos_power_init);