Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 1 | /* |
| 2 | * driver.c - driver support |
| 3 | * |
| 4 | * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> |
| 5 | * Shaohua Li <shaohua.li@intel.com> |
| 6 | * Adam Belay <abelay@novell.com> |
| 7 | * |
| 8 | * This code is licenced under the GPL. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/mutex.h> |
| 12 | #include <linux/module.h> |
Viresh Kumar | d7c7f10 | 2013-10-03 21:26:54 +0530 | [diff] [blame] | 13 | #include <linux/sched.h> |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 14 | #include <linux/cpuidle.h> |
Daniel Lezcano | a06df06 | 2013-03-27 10:22:10 +0000 | [diff] [blame] | 15 | #include <linux/cpumask.h> |
| 16 | #include <linux/clockchips.h> |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 17 | |
| 18 | #include "cpuidle.h" |
| 19 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 20 | DEFINE_SPINLOCK(cpuidle_driver_lock); |
| 21 | |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 22 | #ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS |
| 23 | |
| 24 | static DEFINE_PER_CPU(struct cpuidle_driver *, cpuidle_drivers); |
| 25 | |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 26 | /** |
| 27 | * __cpuidle_get_cpu_driver - return the cpuidle driver tied to a CPU. |
| 28 | * @cpu: the CPU handled by the driver |
| 29 | * |
| 30 | * Returns a pointer to struct cpuidle_driver or NULL if no driver has been |
| 31 | * registered for @cpu. |
| 32 | */ |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 33 | static struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu) |
| 34 | { |
| 35 | return per_cpu(cpuidle_drivers, cpu); |
| 36 | } |
| 37 | |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 38 | /** |
| 39 | * __cpuidle_unset_driver - unset per CPU driver variables. |
| 40 | * @drv: a valid pointer to a struct cpuidle_driver |
| 41 | * |
| 42 | * For each CPU in the driver's CPU mask, unset the registered driver per CPU |
| 43 | * variable. If @drv is different from the registered driver, the corresponding |
| 44 | * variable is not cleared. |
| 45 | */ |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 46 | static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv) |
| 47 | { |
| 48 | int cpu; |
| 49 | |
| 50 | for_each_cpu(cpu, drv->cpumask) { |
| 51 | |
| 52 | if (drv != __cpuidle_get_cpu_driver(cpu)) |
| 53 | continue; |
| 54 | |
| 55 | per_cpu(cpuidle_drivers, cpu) = NULL; |
| 56 | } |
| 57 | } |
| 58 | |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 59 | /** |
Viresh Kumar | caf4a36 | 2013-10-03 21:26:41 +0530 | [diff] [blame] | 60 | * __cpuidle_set_driver - set per CPU driver variables for the given driver. |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 61 | * @drv: a valid pointer to a struct cpuidle_driver |
| 62 | * |
| 63 | * For each CPU in the driver's cpumask, unset the registered driver per CPU |
| 64 | * to @drv. |
| 65 | * |
| 66 | * Returns 0 on success, -EBUSY if the CPUs have driver(s) already. |
| 67 | */ |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 68 | static inline int __cpuidle_set_driver(struct cpuidle_driver *drv) |
| 69 | { |
| 70 | int cpu; |
| 71 | |
| 72 | for_each_cpu(cpu, drv->cpumask) { |
| 73 | |
| 74 | if (__cpuidle_get_cpu_driver(cpu)) { |
| 75 | __cpuidle_unset_driver(drv); |
| 76 | return -EBUSY; |
| 77 | } |
| 78 | |
| 79 | per_cpu(cpuidle_drivers, cpu) = drv; |
| 80 | } |
| 81 | |
| 82 | return 0; |
| 83 | } |
| 84 | |
| 85 | #else |
| 86 | |
| 87 | static struct cpuidle_driver *cpuidle_curr_driver; |
| 88 | |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 89 | /** |
| 90 | * __cpuidle_get_cpu_driver - return the global cpuidle driver pointer. |
| 91 | * @cpu: ignored without the multiple driver support |
| 92 | * |
| 93 | * Return a pointer to a struct cpuidle_driver object or NULL if no driver was |
| 94 | * previously registered. |
| 95 | */ |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 96 | static inline struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu) |
| 97 | { |
| 98 | return cpuidle_curr_driver; |
| 99 | } |
| 100 | |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 101 | /** |
| 102 | * __cpuidle_set_driver - assign the global cpuidle driver variable. |
| 103 | * @drv: pointer to a struct cpuidle_driver object |
| 104 | * |
| 105 | * Returns 0 on success, -EBUSY if the driver is already registered. |
| 106 | */ |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 107 | static inline int __cpuidle_set_driver(struct cpuidle_driver *drv) |
| 108 | { |
| 109 | if (cpuidle_curr_driver) |
| 110 | return -EBUSY; |
| 111 | |
| 112 | cpuidle_curr_driver = drv; |
| 113 | |
| 114 | return 0; |
| 115 | } |
| 116 | |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 117 | /** |
| 118 | * __cpuidle_unset_driver - unset the global cpuidle driver variable. |
| 119 | * @drv: a pointer to a struct cpuidle_driver |
| 120 | * |
| 121 | * Reset the global cpuidle variable to NULL. If @drv does not match the |
| 122 | * registered driver, do nothing. |
| 123 | */ |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 124 | static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv) |
| 125 | { |
| 126 | if (drv == cpuidle_curr_driver) |
| 127 | cpuidle_curr_driver = NULL; |
| 128 | } |
| 129 | |
| 130 | #endif |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 131 | |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 132 | /** |
| 133 | * cpuidle_setup_broadcast_timer - enable/disable the broadcast timer |
| 134 | * @arg: a void pointer used to match the SMP cross call API |
| 135 | * |
Viresh Kumar | caf4a36 | 2013-10-03 21:26:41 +0530 | [diff] [blame] | 136 | * @arg is used as a value of type 'long' with one of the two values: |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 137 | * - CLOCK_EVT_NOTIFY_BROADCAST_ON |
| 138 | * - CLOCK_EVT_NOTIFY_BROADCAST_OFF |
| 139 | * |
| 140 | * Set the broadcast timer notification for the current CPU. This function |
| 141 | * is executed per CPU by an SMP cross call. It not supposed to be called |
| 142 | * directly. |
| 143 | */ |
Daniel Lezcano | a06df06 | 2013-03-27 10:22:10 +0000 | [diff] [blame] | 144 | static void cpuidle_setup_broadcast_timer(void *arg) |
Daniel Lezcano | 13dd52f | 2012-10-31 16:44:47 +0000 | [diff] [blame] | 145 | { |
Daniel Lezcano | a06df06 | 2013-03-27 10:22:10 +0000 | [diff] [blame] | 146 | int cpu = smp_processor_id(); |
| 147 | clockevents_notify((long)(arg), &cpu); |
| 148 | } |
| 149 | |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 150 | /** |
| 151 | * __cpuidle_driver_init - initialize the driver's internal data |
| 152 | * @drv: a valid pointer to a struct cpuidle_driver |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 153 | */ |
Viresh Kumar | e437f3e | 2013-10-03 21:26:44 +0530 | [diff] [blame] | 154 | static void __cpuidle_driver_init(struct cpuidle_driver *drv) |
Daniel Lezcano | a06df06 | 2013-03-27 10:22:10 +0000 | [diff] [blame] | 155 | { |
| 156 | int i; |
| 157 | |
Daniel Lezcano | 13dd52f | 2012-10-31 16:44:47 +0000 | [diff] [blame] | 158 | drv->refcnt = 0; |
Daniel Lezcano | a06df06 | 2013-03-27 10:22:10 +0000 | [diff] [blame] | 159 | |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 160 | /* |
| 161 | * Use all possible CPUs as the default, because if the kernel boots |
| 162 | * with some CPUs offline and then we online one of them, the CPU |
| 163 | * notifier has to know which driver to assign. |
| 164 | */ |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 165 | if (!drv->cpumask) |
| 166 | drv->cpumask = (struct cpumask *)cpu_possible_mask; |
| 167 | |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 168 | /* |
| 169 | * Look for the timer stop flag in the different states, so that we know |
| 170 | * if the broadcast timer has to be set up. The loop is in the reverse |
Viresh Kumar | caf4a36 | 2013-10-03 21:26:41 +0530 | [diff] [blame] | 171 | * order, because usually one of the deeper states have this flag set. |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 172 | */ |
Daniel Lezcano | a06df06 | 2013-03-27 10:22:10 +0000 | [diff] [blame] | 173 | for (i = drv->state_count - 1; i >= 0 ; i--) { |
Viresh Kumar | b171a85 | 2013-10-03 21:26:45 +0530 | [diff] [blame] | 174 | if (drv->states[i].flags & CPUIDLE_FLAG_TIMER_STOP) { |
| 175 | drv->bctimer = 1; |
| 176 | break; |
| 177 | } |
Daniel Lezcano | a06df06 | 2013-03-27 10:22:10 +0000 | [diff] [blame] | 178 | } |
Daniel Lezcano | 13dd52f | 2012-10-31 16:44:47 +0000 | [diff] [blame] | 179 | } |
| 180 | |
Viresh Kumar | d7c7f10 | 2013-10-03 21:26:54 +0530 | [diff] [blame] | 181 | #ifdef CONFIG_ARCH_HAS_CPU_RELAX |
| 182 | static int poll_idle(struct cpuidle_device *dev, |
| 183 | struct cpuidle_driver *drv, int index) |
| 184 | { |
Viresh Kumar | d7c7f10 | 2013-10-03 21:26:54 +0530 | [diff] [blame] | 185 | local_irq_enable(); |
Andy Lutomirski | 84c4070 | 2014-06-04 10:31:14 -0700 | [diff] [blame] | 186 | if (!current_set_polling_and_test()) { |
| 187 | while (!need_resched()) |
| 188 | cpu_relax(); |
| 189 | } |
| 190 | current_clr_polling(); |
Viresh Kumar | d7c7f10 | 2013-10-03 21:26:54 +0530 | [diff] [blame] | 191 | |
Viresh Kumar | d7c7f10 | 2013-10-03 21:26:54 +0530 | [diff] [blame] | 192 | return index; |
| 193 | } |
| 194 | |
| 195 | static void poll_idle_init(struct cpuidle_driver *drv) |
| 196 | { |
| 197 | struct cpuidle_state *state = &drv->states[0]; |
| 198 | |
| 199 | snprintf(state->name, CPUIDLE_NAME_LEN, "POLL"); |
| 200 | snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE"); |
| 201 | state->exit_latency = 0; |
| 202 | state->target_residency = 0; |
| 203 | state->power_usage = -1; |
tuukka.tikkanen@linaro.org | 4b2f0b0 | 2014-02-24 08:29:37 +0200 | [diff] [blame] | 204 | state->flags = CPUIDLE_FLAG_TIME_VALID; |
Viresh Kumar | d7c7f10 | 2013-10-03 21:26:54 +0530 | [diff] [blame] | 205 | state->enter = poll_idle; |
| 206 | state->disabled = false; |
| 207 | } |
| 208 | #else |
| 209 | static void poll_idle_init(struct cpuidle_driver *drv) {} |
| 210 | #endif /* !CONFIG_ARCH_HAS_CPU_RELAX */ |
| 211 | |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 212 | /** |
| 213 | * __cpuidle_register_driver: register the driver |
| 214 | * @drv: a valid pointer to a struct cpuidle_driver |
| 215 | * |
| 216 | * Do some sanity checks, initialize the driver, assign the driver to the |
| 217 | * global cpuidle driver variable(s) and set up the broadcast timer if the |
| 218 | * cpuidle driver has some states that shut down the local timer. |
| 219 | * |
| 220 | * Returns 0 on success, a negative error code otherwise: |
| 221 | * * -EINVAL if the driver pointer is NULL or no idle states are available |
| 222 | * * -ENODEV if the cpuidle framework is disabled |
| 223 | * * -EBUSY if the driver is already assigned to the global variable(s) |
| 224 | */ |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 225 | static int __cpuidle_register_driver(struct cpuidle_driver *drv) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 226 | { |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 227 | int ret; |
| 228 | |
Daniel Lezcano | fc850f3 | 2012-03-26 14:51:26 +0200 | [diff] [blame] | 229 | if (!drv || !drv->state_count) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 230 | return -EINVAL; |
| 231 | |
Len Brown | 62027ae | 2011-04-01 18:13:10 -0400 | [diff] [blame] | 232 | if (cpuidle_disabled()) |
| 233 | return -ENODEV; |
| 234 | |
Viresh Kumar | e437f3e | 2013-10-03 21:26:44 +0530 | [diff] [blame] | 235 | __cpuidle_driver_init(drv); |
Daniel Lezcano | ed95347 | 2012-09-22 00:38:32 +0200 | [diff] [blame] | 236 | |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 237 | ret = __cpuidle_set_driver(drv); |
| 238 | if (ret) |
| 239 | return ret; |
Daniel Lezcano | ed95347 | 2012-09-22 00:38:32 +0200 | [diff] [blame] | 240 | |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 241 | if (drv->bctimer) |
| 242 | on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer, |
| 243 | (void *)CLOCK_EVT_NOTIFY_BROADCAST_ON, 1); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 244 | |
Viresh Kumar | d7c7f10 | 2013-10-03 21:26:54 +0530 | [diff] [blame] | 245 | poll_idle_init(drv); |
| 246 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 247 | return 0; |
| 248 | } |
Daniel Lezcano | 13dd52f | 2012-10-31 16:44:47 +0000 | [diff] [blame] | 249 | |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 250 | /** |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 251 | * __cpuidle_unregister_driver - unregister the driver |
| 252 | * @drv: a valid pointer to a struct cpuidle_driver |
| 253 | * |
| 254 | * Check if the driver is no longer in use, reset the global cpuidle driver |
| 255 | * variable(s) and disable the timer broadcast notification mechanism if it was |
| 256 | * in use. |
| 257 | * |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 258 | */ |
| 259 | static void __cpuidle_unregister_driver(struct cpuidle_driver *drv) |
Daniel Lezcano | 13dd52f | 2012-10-31 16:44:47 +0000 | [diff] [blame] | 260 | { |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 261 | if (WARN_ON(drv->refcnt > 0)) |
Daniel Lezcano | 13dd52f | 2012-10-31 16:44:47 +0000 | [diff] [blame] | 262 | return; |
| 263 | |
Daniel Lezcano | a06df06 | 2013-03-27 10:22:10 +0000 | [diff] [blame] | 264 | if (drv->bctimer) { |
| 265 | drv->bctimer = 0; |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 266 | on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer, |
Daniel Lezcano | a06df06 | 2013-03-27 10:22:10 +0000 | [diff] [blame] | 267 | (void *)CLOCK_EVT_NOTIFY_BROADCAST_OFF, 1); |
| 268 | } |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 269 | |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 270 | __cpuidle_unset_driver(drv); |
Daniel Lezcano | 13dd52f | 2012-10-31 16:44:47 +0000 | [diff] [blame] | 271 | } |
| 272 | |
| 273 | /** |
| 274 | * cpuidle_register_driver - registers a driver |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 275 | * @drv: a pointer to a valid struct cpuidle_driver |
| 276 | * |
| 277 | * Register the driver under a lock to prevent concurrent attempts to |
| 278 | * [un]register the driver from occuring at the same time. |
| 279 | * |
| 280 | * Returns 0 on success, a negative error code (returned by |
| 281 | * __cpuidle_register_driver()) otherwise. |
Daniel Lezcano | 13dd52f | 2012-10-31 16:44:47 +0000 | [diff] [blame] | 282 | */ |
| 283 | int cpuidle_register_driver(struct cpuidle_driver *drv) |
| 284 | { |
| 285 | int ret; |
| 286 | |
| 287 | spin_lock(&cpuidle_driver_lock); |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 288 | ret = __cpuidle_register_driver(drv); |
Daniel Lezcano | 13dd52f | 2012-10-31 16:44:47 +0000 | [diff] [blame] | 289 | spin_unlock(&cpuidle_driver_lock); |
| 290 | |
| 291 | return ret; |
| 292 | } |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 293 | EXPORT_SYMBOL_GPL(cpuidle_register_driver); |
| 294 | |
| 295 | /** |
| 296 | * cpuidle_unregister_driver - unregisters a driver |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 297 | * @drv: a pointer to a valid struct cpuidle_driver |
| 298 | * |
| 299 | * Unregisters the cpuidle driver under a lock to prevent concurrent attempts |
| 300 | * to [un]register the driver from occuring at the same time. @drv has to |
| 301 | * match the currently registered driver. |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 302 | */ |
| 303 | void cpuidle_unregister_driver(struct cpuidle_driver *drv) |
| 304 | { |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 305 | spin_lock(&cpuidle_driver_lock); |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 306 | __cpuidle_unregister_driver(drv); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 307 | spin_unlock(&cpuidle_driver_lock); |
| 308 | } |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 309 | EXPORT_SYMBOL_GPL(cpuidle_unregister_driver); |
Rafael J. Wysocki | 6e797a0 | 2012-06-16 15:20:11 +0200 | [diff] [blame] | 310 | |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 311 | /** |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 312 | * cpuidle_get_driver - return the driver tied to the current CPU. |
| 313 | * |
| 314 | * Returns a struct cpuidle_driver pointer, or NULL if no driver is registered. |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 315 | */ |
| 316 | struct cpuidle_driver *cpuidle_get_driver(void) |
| 317 | { |
| 318 | struct cpuidle_driver *drv; |
| 319 | int cpu; |
| 320 | |
| 321 | cpu = get_cpu(); |
| 322 | drv = __cpuidle_get_cpu_driver(cpu); |
| 323 | put_cpu(); |
| 324 | |
| 325 | return drv; |
| 326 | } |
| 327 | EXPORT_SYMBOL_GPL(cpuidle_get_driver); |
| 328 | |
| 329 | /** |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 330 | * cpuidle_get_cpu_driver - return the driver registered for a CPU. |
| 331 | * @dev: a valid pointer to a struct cpuidle_device |
| 332 | * |
| 333 | * Returns a struct cpuidle_driver pointer, or NULL if no driver is registered |
| 334 | * for the CPU associated with @dev. |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 335 | */ |
| 336 | struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev) |
| 337 | { |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 338 | if (!dev) |
| 339 | return NULL; |
| 340 | |
Daniel Lezcano | ac34d7c | 2013-01-03 13:03:18 +0100 | [diff] [blame] | 341 | return __cpuidle_get_cpu_driver(dev->cpu); |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 342 | } |
| 343 | EXPORT_SYMBOL_GPL(cpuidle_get_cpu_driver); |
| 344 | |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 345 | /** |
| 346 | * cpuidle_driver_ref - get a reference to the driver. |
| 347 | * |
| 348 | * Increment the reference counter of the cpuidle driver associated with |
| 349 | * the current CPU. |
| 350 | * |
| 351 | * Returns a pointer to the driver, or NULL if the current CPU has no driver. |
| 352 | */ |
Rafael J. Wysocki | 6e797a0 | 2012-06-16 15:20:11 +0200 | [diff] [blame] | 353 | struct cpuidle_driver *cpuidle_driver_ref(void) |
| 354 | { |
| 355 | struct cpuidle_driver *drv; |
| 356 | |
| 357 | spin_lock(&cpuidle_driver_lock); |
| 358 | |
Daniel Lezcano | 13dd52f | 2012-10-31 16:44:47 +0000 | [diff] [blame] | 359 | drv = cpuidle_get_driver(); |
Daniel Fu | 3b9c10e | 2013-08-30 19:48:22 +0800 | [diff] [blame] | 360 | if (drv) |
| 361 | drv->refcnt++; |
Rafael J. Wysocki | 6e797a0 | 2012-06-16 15:20:11 +0200 | [diff] [blame] | 362 | |
| 363 | spin_unlock(&cpuidle_driver_lock); |
| 364 | return drv; |
| 365 | } |
| 366 | |
Daniel Lezcano | 6d19cb9 | 2013-06-07 21:53:10 +0000 | [diff] [blame] | 367 | /** |
| 368 | * cpuidle_driver_unref - puts down the refcount for the driver |
| 369 | * |
| 370 | * Decrement the reference counter of the cpuidle driver associated with |
| 371 | * the current CPU. |
| 372 | */ |
Rafael J. Wysocki | 6e797a0 | 2012-06-16 15:20:11 +0200 | [diff] [blame] | 373 | void cpuidle_driver_unref(void) |
| 374 | { |
Viresh Kumar | 0d09d31 | 2013-10-03 21:26:50 +0530 | [diff] [blame] | 375 | struct cpuidle_driver *drv; |
Daniel Lezcano | 42f67f2 | 2012-10-31 16:44:45 +0000 | [diff] [blame] | 376 | |
Rafael J. Wysocki | 6e797a0 | 2012-06-16 15:20:11 +0200 | [diff] [blame] | 377 | spin_lock(&cpuidle_driver_lock); |
| 378 | |
Viresh Kumar | 0d09d31 | 2013-10-03 21:26:50 +0530 | [diff] [blame] | 379 | drv = cpuidle_get_driver(); |
Daniel Lezcano | 42f67f2 | 2012-10-31 16:44:45 +0000 | [diff] [blame] | 380 | if (drv && !WARN_ON(drv->refcnt <= 0)) |
| 381 | drv->refcnt--; |
Rafael J. Wysocki | 6e797a0 | 2012-06-16 15:20:11 +0200 | [diff] [blame] | 382 | |
| 383 | spin_unlock(&cpuidle_driver_lock); |
| 384 | } |