linux/include/linux/pm_qos.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Definitions related to Power Management Quality of Service (PM QoS).
   4 *
   5 * Copyright (C) 2020 Intel Corporation
   6 *
   7 * Authors:
   8 *      Mark Gross <mgross@linux.intel.com>
   9 *      Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  10 */
  11
  12#ifndef _LINUX_PM_QOS_H
  13#define _LINUX_PM_QOS_H
  14
  15#include <linux/plist.h>
  16#include <linux/notifier.h>
  17#include <linux/device.h>
  18
  19enum pm_qos_flags_status {
  20        PM_QOS_FLAGS_UNDEFINED = -1,
  21        PM_QOS_FLAGS_NONE,
  22        PM_QOS_FLAGS_SOME,
  23        PM_QOS_FLAGS_ALL,
  24};
  25
  26#define PM_QOS_DEFAULT_VALUE    (-1)
  27#define PM_QOS_LATENCY_ANY      S32_MAX
  28#define PM_QOS_LATENCY_ANY_NS   ((s64)PM_QOS_LATENCY_ANY * NSEC_PER_USEC)
  29
  30#define PM_QOS_CPU_LATENCY_DEFAULT_VALUE        (2000 * USEC_PER_SEC)
  31#define PM_QOS_RESUME_LATENCY_DEFAULT_VALUE     PM_QOS_LATENCY_ANY
  32#define PM_QOS_RESUME_LATENCY_NO_CONSTRAINT     PM_QOS_LATENCY_ANY
  33#define PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS  PM_QOS_LATENCY_ANY_NS
  34#define PM_QOS_LATENCY_TOLERANCE_DEFAULT_VALUE  0
  35#define PM_QOS_MIN_FREQUENCY_DEFAULT_VALUE      0
  36#define PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE      FREQ_QOS_MAX_DEFAULT_VALUE
  37#define PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT  (-1)
  38
  39#define PM_QOS_FLAG_NO_POWER_OFF        (1 << 0)
  40
  41enum pm_qos_type {
  42        PM_QOS_UNITIALIZED,
  43        PM_QOS_MAX,             /* return the largest value */
  44        PM_QOS_MIN,             /* return the smallest value */
  45};
  46
  47/*
  48 * Note: The lockless read path depends on the CPU accessing target_value
  49 * or effective_flags atomically.  Atomic access is only guaranteed on all CPU
  50 * types linux supports for 32 bit quantites
  51 */
  52struct pm_qos_constraints {
  53        struct plist_head list;
  54        s32 target_value;       /* Do not change to 64 bit */
  55        s32 default_value;
  56        s32 no_constraint_value;
  57        enum pm_qos_type type;
  58        struct blocking_notifier_head *notifiers;
  59};
  60
  61struct pm_qos_request {
  62        struct plist_node node;
  63        struct pm_qos_constraints *qos;
  64};
  65
  66struct pm_qos_flags_request {
  67        struct list_head node;
  68        s32 flags;      /* Do not change to 64 bit */
  69};
  70
  71struct pm_qos_flags {
  72        struct list_head list;
  73        s32 effective_flags;    /* Do not change to 64 bit */
  74};
  75
  76
  77#define FREQ_QOS_MIN_DEFAULT_VALUE      0
  78#define FREQ_QOS_MAX_DEFAULT_VALUE      S32_MAX
  79
  80enum freq_qos_req_type {
  81        FREQ_QOS_MIN = 1,
  82        FREQ_QOS_MAX,
  83};
  84
  85struct freq_constraints {
  86        struct pm_qos_constraints min_freq;
  87        struct blocking_notifier_head min_freq_notifiers;
  88        struct pm_qos_constraints max_freq;
  89        struct blocking_notifier_head max_freq_notifiers;
  90};
  91
  92struct freq_qos_request {
  93        enum freq_qos_req_type type;
  94        struct plist_node pnode;
  95        struct freq_constraints *qos;
  96};
  97
  98
  99enum dev_pm_qos_req_type {
 100        DEV_PM_QOS_RESUME_LATENCY = 1,
 101        DEV_PM_QOS_LATENCY_TOLERANCE,
 102        DEV_PM_QOS_MIN_FREQUENCY,
 103        DEV_PM_QOS_MAX_FREQUENCY,
 104        DEV_PM_QOS_FLAGS,
 105};
 106
 107struct dev_pm_qos_request {
 108        enum dev_pm_qos_req_type type;
 109        union {
 110                struct plist_node pnode;
 111                struct pm_qos_flags_request flr;
 112                struct freq_qos_request freq;
 113        } data;
 114        struct device *dev;
 115};
 116
 117struct dev_pm_qos {
 118        struct pm_qos_constraints resume_latency;
 119        struct pm_qos_constraints latency_tolerance;
 120        struct freq_constraints freq;
 121        struct pm_qos_flags flags;
 122        struct dev_pm_qos_request *resume_latency_req;
 123        struct dev_pm_qos_request *latency_tolerance_req;
 124        struct dev_pm_qos_request *flags_req;
 125};
 126
 127/* Action requested to pm_qos_update_target */
 128enum pm_qos_req_action {
 129        PM_QOS_ADD_REQ,         /* Add a new request */
 130        PM_QOS_UPDATE_REQ,      /* Update an existing request */
 131        PM_QOS_REMOVE_REQ       /* Remove an existing request */
 132};
 133
 134static inline int dev_pm_qos_request_active(struct dev_pm_qos_request *req)
 135{
 136        return req->dev != NULL;
 137}
 138
 139s32 pm_qos_read_value(struct pm_qos_constraints *c);
 140int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
 141                         enum pm_qos_req_action action, int value);
 142bool pm_qos_update_flags(struct pm_qos_flags *pqf,
 143                         struct pm_qos_flags_request *req,
 144                         enum pm_qos_req_action action, s32 val);
 145
 146#ifdef CONFIG_CPU_IDLE
 147s32 cpu_latency_qos_limit(void);
 148bool cpu_latency_qos_request_active(struct pm_qos_request *req);
 149void cpu_latency_qos_add_request(struct pm_qos_request *req, s32 value);
 150void cpu_latency_qos_update_request(struct pm_qos_request *req, s32 new_value);
 151void cpu_latency_qos_remove_request(struct pm_qos_request *req);
 152#else
 153static inline s32 cpu_latency_qos_limit(void) { return INT_MAX; }
 154static inline bool cpu_latency_qos_request_active(struct pm_qos_request *req)
 155{
 156        return false;
 157}
 158static inline void cpu_latency_qos_add_request(struct pm_qos_request *req,
 159                                               s32 value) {}
 160static inline void cpu_latency_qos_update_request(struct pm_qos_request *req,
 161                                                  s32 new_value) {}
 162static inline void cpu_latency_qos_remove_request(struct pm_qos_request *req) {}
 163#endif
 164
 165#ifdef CONFIG_PM
 166enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask);
 167enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask);
 168s32 __dev_pm_qos_resume_latency(struct device *dev);
 169s32 dev_pm_qos_read_value(struct device *dev, enum dev_pm_qos_req_type type);
 170int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
 171                           enum dev_pm_qos_req_type type, s32 value);
 172int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value);
 173int dev_pm_qos_remove_request(struct dev_pm_qos_request *req);
 174int dev_pm_qos_add_notifier(struct device *dev,
 175                            struct notifier_block *notifier,
 176                            enum dev_pm_qos_req_type type);
 177int dev_pm_qos_remove_notifier(struct device *dev,
 178                               struct notifier_block *notifier,
 179                               enum dev_pm_qos_req_type type);
 180void dev_pm_qos_constraints_init(struct device *dev);
 181void dev_pm_qos_constraints_destroy(struct device *dev);
 182int dev_pm_qos_add_ancestor_request(struct device *dev,
 183                                    struct dev_pm_qos_request *req,
 184                                    enum dev_pm_qos_req_type type, s32 value);
 185int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value);
 186void dev_pm_qos_hide_latency_limit(struct device *dev);
 187int dev_pm_qos_expose_flags(struct device *dev, s32 value);
 188void dev_pm_qos_hide_flags(struct device *dev);
 189int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set);
 190s32 dev_pm_qos_get_user_latency_tolerance(struct device *dev);
 191int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val);
 192int dev_pm_qos_expose_latency_tolerance(struct device *dev);
 193void dev_pm_qos_hide_latency_tolerance(struct device *dev);
 194
 195static inline s32 dev_pm_qos_requested_resume_latency(struct device *dev)
 196{
 197        return dev->power.qos->resume_latency_req->data.pnode.prio;
 198}
 199
 200static inline s32 dev_pm_qos_requested_flags(struct device *dev)
 201{
 202        return dev->power.qos->flags_req->data.flr.flags;
 203}
 204
 205static inline s32 dev_pm_qos_raw_resume_latency(struct device *dev)
 206{
 207        return IS_ERR_OR_NULL(dev->power.qos) ?
 208                PM_QOS_RESUME_LATENCY_NO_CONSTRAINT :
 209                pm_qos_read_value(&dev->power.qos->resume_latency);
 210}
 211#else
 212static inline enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev,
 213                                                          s32 mask)
 214                        { return PM_QOS_FLAGS_UNDEFINED; }
 215static inline enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev,
 216                                                        s32 mask)
 217                        { return PM_QOS_FLAGS_UNDEFINED; }
 218static inline s32 __dev_pm_qos_resume_latency(struct device *dev)
 219                        { return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; }
 220static inline s32 dev_pm_qos_read_value(struct device *dev,
 221                                        enum dev_pm_qos_req_type type)
 222{
 223        switch (type) {
 224        case DEV_PM_QOS_RESUME_LATENCY:
 225                return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
 226        case DEV_PM_QOS_MIN_FREQUENCY:
 227                return PM_QOS_MIN_FREQUENCY_DEFAULT_VALUE;
 228        case DEV_PM_QOS_MAX_FREQUENCY:
 229                return PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE;
 230        default:
 231                WARN_ON(1);
 232                return 0;
 233        }
 234}
 235
 236static inline int dev_pm_qos_add_request(struct device *dev,
 237                                         struct dev_pm_qos_request *req,
 238                                         enum dev_pm_qos_req_type type,
 239                                         s32 value)
 240                        { return 0; }
 241static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
 242                                            s32 new_value)
 243                        { return 0; }
 244static inline int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
 245                        { return 0; }
 246static inline int dev_pm_qos_add_notifier(struct device *dev,
 247                                          struct notifier_block *notifier,
 248                                          enum dev_pm_qos_req_type type)
 249                        { return 0; }
 250static inline int dev_pm_qos_remove_notifier(struct device *dev,
 251                                             struct notifier_block *notifier,
 252                                             enum dev_pm_qos_req_type type)
 253                        { return 0; }
 254static inline void dev_pm_qos_constraints_init(struct device *dev)
 255{
 256        dev->power.power_state = PMSG_ON;
 257}
 258static inline void dev_pm_qos_constraints_destroy(struct device *dev)
 259{
 260        dev->power.power_state = PMSG_INVALID;
 261}
 262static inline int dev_pm_qos_add_ancestor_request(struct device *dev,
 263                                                  struct dev_pm_qos_request *req,
 264                                                  enum dev_pm_qos_req_type type,
 265                                                  s32 value)
 266                        { return 0; }
 267static inline int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value)
 268                        { return 0; }
 269static inline void dev_pm_qos_hide_latency_limit(struct device *dev) {}
 270static inline int dev_pm_qos_expose_flags(struct device *dev, s32 value)
 271                        { return 0; }
 272static inline void dev_pm_qos_hide_flags(struct device *dev) {}
 273static inline int dev_pm_qos_update_flags(struct device *dev, s32 m, bool set)
 274                        { return 0; }
 275static inline s32 dev_pm_qos_get_user_latency_tolerance(struct device *dev)
 276                        { return PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT; }
 277static inline int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val)
 278                        { return 0; }
 279static inline int dev_pm_qos_expose_latency_tolerance(struct device *dev)
 280                        { return 0; }
 281static inline void dev_pm_qos_hide_latency_tolerance(struct device *dev) {}
 282
 283static inline s32 dev_pm_qos_requested_resume_latency(struct device *dev)
 284{
 285        return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
 286}
 287static inline s32 dev_pm_qos_requested_flags(struct device *dev) { return 0; }
 288static inline s32 dev_pm_qos_raw_resume_latency(struct device *dev)
 289{
 290        return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
 291}
 292#endif
 293
 294static inline int freq_qos_request_active(struct freq_qos_request *req)
 295{
 296        return !IS_ERR_OR_NULL(req->qos);
 297}
 298
 299void freq_constraints_init(struct freq_constraints *qos);
 300
 301s32 freq_qos_read_value(struct freq_constraints *qos,
 302                        enum freq_qos_req_type type);
 303
 304int freq_qos_add_request(struct freq_constraints *qos,
 305                         struct freq_qos_request *req,
 306                         enum freq_qos_req_type type, s32 value);
 307int freq_qos_update_request(struct freq_qos_request *req, s32 new_value);
 308int freq_qos_remove_request(struct freq_qos_request *req);
 309int freq_qos_apply(struct freq_qos_request *req,
 310                   enum pm_qos_req_action action, s32 value);
 311
 312int freq_qos_add_notifier(struct freq_constraints *qos,
 313                          enum freq_qos_req_type type,
 314                          struct notifier_block *notifier);
 315int freq_qos_remove_notifier(struct freq_constraints *qos,
 316                             enum freq_qos_req_type type,
 317                             struct notifier_block *notifier);
 318
 319#endif
 320