Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 1 | /* |
| 2 | * cpuidle.c - core cpuidle infrastructure |
| 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/kernel.h> |
| 12 | #include <linux/mutex.h> |
| 13 | #include <linux/sched.h> |
| 14 | #include <linux/notifier.h> |
Jean Pihet | e8db0be | 2011-08-25 15:35:03 +0200 | [diff] [blame] | 15 | #include <linux/pm_qos.h> |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 16 | #include <linux/cpu.h> |
| 17 | #include <linux/cpuidle.h> |
venkatesh.pallipadi@intel.com | 9a0b841 | 2008-01-31 17:35:06 -0800 | [diff] [blame] | 18 | #include <linux/ktime.h> |
Arjan van de Ven | 2e94d1f | 2008-09-10 16:06:00 -0700 | [diff] [blame] | 19 | #include <linux/hrtimer.h> |
Paul Gortmaker | 884b17e | 2011-08-29 17:52:39 -0400 | [diff] [blame] | 20 | #include <linux/module.h> |
Arjan van de Ven | 288f023 | 2009-09-19 13:35:33 +0200 | [diff] [blame] | 21 | #include <trace/events/power.h> |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 22 | |
| 23 | #include "cpuidle.h" |
| 24 | |
| 25 | DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 26 | |
| 27 | DEFINE_MUTEX(cpuidle_lock); |
| 28 | LIST_HEAD(cpuidle_detected_devices); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 29 | |
| 30 | static int enabled_devices; |
Len Brown | 62027ae | 2011-04-01 18:13:10 -0400 | [diff] [blame] | 31 | static int off __read_mostly; |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 32 | static int initialized __read_mostly; |
Len Brown | 62027ae | 2011-04-01 18:13:10 -0400 | [diff] [blame] | 33 | |
| 34 | int cpuidle_disabled(void) |
| 35 | { |
| 36 | return off; |
| 37 | } |
Len Brown | d91ee58 | 2011-04-01 18:28:35 -0400 | [diff] [blame] | 38 | void disable_cpuidle(void) |
| 39 | { |
| 40 | off = 1; |
| 41 | } |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 42 | |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 43 | static int __cpuidle_register_device(struct cpuidle_device *dev); |
| 44 | |
Robert Lee | e168979 | 2012-03-20 15:22:42 -0500 | [diff] [blame] | 45 | static inline int cpuidle_enter(struct cpuidle_device *dev, |
| 46 | struct cpuidle_driver *drv, int index) |
| 47 | { |
| 48 | struct cpuidle_state *target_state = &drv->states[index]; |
| 49 | return target_state->enter(dev, drv, index); |
| 50 | } |
| 51 | |
| 52 | static inline int cpuidle_enter_tk(struct cpuidle_device *dev, |
| 53 | struct cpuidle_driver *drv, int index) |
| 54 | { |
| 55 | return cpuidle_wrap_enter(dev, drv, index, cpuidle_enter); |
| 56 | } |
| 57 | |
| 58 | typedef int (*cpuidle_enter_t)(struct cpuidle_device *dev, |
| 59 | struct cpuidle_driver *drv, int index); |
| 60 | |
| 61 | static cpuidle_enter_t cpuidle_enter_ops; |
| 62 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 63 | /** |
Boris Ostrovsky | 1a022e3 | 2012-03-13 19:55:09 +0100 | [diff] [blame] | 64 | * cpuidle_play_dead - cpu off-lining |
| 65 | * |
Toshi Kani | ee01e66 | 2012-03-31 21:37:02 -0600 | [diff] [blame] | 66 | * Returns in case of an error or no driver |
Boris Ostrovsky | 1a022e3 | 2012-03-13 19:55:09 +0100 | [diff] [blame] | 67 | */ |
| 68 | int cpuidle_play_dead(void) |
| 69 | { |
| 70 | struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); |
| 71 | struct cpuidle_driver *drv = cpuidle_get_driver(); |
| 72 | int i, dead_state = -1; |
| 73 | int power_usage = -1; |
| 74 | |
Toshi Kani | ee01e66 | 2012-03-31 21:37:02 -0600 | [diff] [blame] | 75 | if (!drv) |
| 76 | return -ENODEV; |
| 77 | |
Boris Ostrovsky | 1a022e3 | 2012-03-13 19:55:09 +0100 | [diff] [blame] | 78 | /* Find lowest-power state that supports long-term idle */ |
| 79 | for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) { |
| 80 | struct cpuidle_state *s = &drv->states[i]; |
| 81 | |
| 82 | if (s->power_usage < power_usage && s->enter_dead) { |
| 83 | power_usage = s->power_usage; |
| 84 | dead_state = i; |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | if (dead_state != -1) |
| 89 | return drv->states[dead_state].enter_dead(dev, dead_state); |
| 90 | |
| 91 | return -ENODEV; |
| 92 | } |
| 93 | |
| 94 | /** |
Colin Cross | 56cfbf7 | 2012-05-07 17:57:39 -0700 | [diff] [blame] | 95 | * cpuidle_enter_state - enter the state and update stats |
| 96 | * @dev: cpuidle device for this cpu |
| 97 | * @drv: cpuidle driver for this cpu |
| 98 | * @next_state: index into drv->states of the state to enter |
| 99 | */ |
| 100 | int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, |
| 101 | int next_state) |
| 102 | { |
| 103 | int entered_state; |
| 104 | |
| 105 | entered_state = cpuidle_enter_ops(dev, drv, next_state); |
| 106 | |
| 107 | if (entered_state >= 0) { |
| 108 | /* Update cpuidle counters */ |
| 109 | /* This can be moved to within driver enter routine |
| 110 | * but that results in multiple copies of same code. |
| 111 | */ |
| 112 | dev->states_usage[entered_state].time += |
| 113 | (unsigned long long)dev->last_residency; |
| 114 | dev->states_usage[entered_state].usage++; |
| 115 | } else { |
| 116 | dev->last_residency = 0; |
| 117 | } |
| 118 | |
| 119 | return entered_state; |
| 120 | } |
| 121 | |
| 122 | /** |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 123 | * cpuidle_idle_call - the main idle loop |
| 124 | * |
| 125 | * NOTE: no locks or semaphores should be used here |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 126 | * return non-zero on failure |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 127 | */ |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 128 | int cpuidle_idle_call(void) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 129 | { |
Christoph Lameter | 4a6f4fe | 2010-12-06 11:16:24 -0600 | [diff] [blame] | 130 | struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); |
Deepthi Dharwar | 46bcfad | 2011-10-28 16:20:42 +0530 | [diff] [blame] | 131 | struct cpuidle_driver *drv = cpuidle_get_driver(); |
Deepthi Dharwar | e978aa7 | 2011-10-28 16:20:09 +0530 | [diff] [blame] | 132 | int next_state, entered_state; |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 133 | |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 134 | if (off) |
| 135 | return -ENODEV; |
| 136 | |
| 137 | if (!initialized) |
| 138 | return -ENODEV; |
| 139 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 140 | /* check if the device is ready */ |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 141 | if (!dev || !dev->enabled) |
| 142 | return -EBUSY; |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 143 | |
| 144 | /* ask the governor for the next state */ |
Deepthi Dharwar | 46bcfad | 2011-10-28 16:20:42 +0530 | [diff] [blame] | 145 | next_state = cpuidle_curr_governor->select(drv, dev); |
Kevin Hilman | 246eb7f | 2009-10-26 16:50:18 -0700 | [diff] [blame] | 146 | if (need_resched()) { |
| 147 | local_irq_enable(); |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 148 | return 0; |
Kevin Hilman | 246eb7f | 2009-10-26 16:50:18 -0700 | [diff] [blame] | 149 | } |
| 150 | |
Steven Rostedt | 76027ea | 2012-02-07 09:46:01 -0500 | [diff] [blame] | 151 | trace_power_start_rcuidle(POWER_CSTATE, next_state, dev->cpu); |
| 152 | trace_cpu_idle_rcuidle(next_state, dev->cpu); |
Thomas Renninger | f77cfe4 | 2011-01-07 11:29:44 +0100 | [diff] [blame] | 153 | |
Colin Cross | 4126c01 | 2012-05-07 17:57:41 -0700 | [diff] [blame] | 154 | if (cpuidle_state_is_coupled(dev, drv, next_state)) |
| 155 | entered_state = cpuidle_enter_state_coupled(dev, drv, |
| 156 | next_state); |
| 157 | else |
| 158 | entered_state = cpuidle_enter_state(dev, drv, next_state); |
Thomas Renninger | f77cfe4 | 2011-01-07 11:29:44 +0100 | [diff] [blame] | 159 | |
Steven Rostedt | 76027ea | 2012-02-07 09:46:01 -0500 | [diff] [blame] | 160 | trace_power_end_rcuidle(dev->cpu); |
| 161 | trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); |
Thomas Renninger | f77cfe4 | 2011-01-07 11:29:44 +0100 | [diff] [blame] | 162 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 163 | /* give the governor an opportunity to reflect on the outcome */ |
| 164 | if (cpuidle_curr_governor->reflect) |
Deepthi Dharwar | e978aa7 | 2011-10-28 16:20:09 +0530 | [diff] [blame] | 165 | cpuidle_curr_governor->reflect(dev, entered_state); |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 166 | |
| 167 | return 0; |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 168 | } |
| 169 | |
| 170 | /** |
| 171 | * cpuidle_install_idle_handler - installs the cpuidle idle loop handler |
| 172 | */ |
| 173 | void cpuidle_install_idle_handler(void) |
| 174 | { |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 175 | if (enabled_devices) { |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 176 | /* Make sure all changes finished before we switch to new idle */ |
| 177 | smp_wmb(); |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 178 | initialized = 1; |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 179 | } |
| 180 | } |
| 181 | |
| 182 | /** |
| 183 | * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler |
| 184 | */ |
| 185 | void cpuidle_uninstall_idle_handler(void) |
| 186 | { |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 187 | if (enabled_devices) { |
| 188 | initialized = 0; |
Thomas Gleixner | 4a16251 | 2012-05-07 17:59:48 +0000 | [diff] [blame] | 189 | kick_all_cpus_sync(); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 190 | } |
| 191 | } |
| 192 | |
| 193 | /** |
| 194 | * cpuidle_pause_and_lock - temporarily disables CPUIDLE |
| 195 | */ |
| 196 | void cpuidle_pause_and_lock(void) |
| 197 | { |
| 198 | mutex_lock(&cpuidle_lock); |
| 199 | cpuidle_uninstall_idle_handler(); |
| 200 | } |
| 201 | |
| 202 | EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock); |
| 203 | |
| 204 | /** |
| 205 | * cpuidle_resume_and_unlock - resumes CPUIDLE operation |
| 206 | */ |
| 207 | void cpuidle_resume_and_unlock(void) |
| 208 | { |
| 209 | cpuidle_install_idle_handler(); |
| 210 | mutex_unlock(&cpuidle_lock); |
| 211 | } |
| 212 | |
| 213 | EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); |
| 214 | |
Preeti U Murthy | 8651f97 | 2012-07-09 10:12:56 +0200 | [diff] [blame] | 215 | /* Currently used in suspend/resume path to suspend cpuidle */ |
| 216 | void cpuidle_pause(void) |
| 217 | { |
| 218 | mutex_lock(&cpuidle_lock); |
| 219 | cpuidle_uninstall_idle_handler(); |
| 220 | mutex_unlock(&cpuidle_lock); |
| 221 | } |
| 222 | |
| 223 | /* Currently used in suspend/resume path to resume cpuidle */ |
| 224 | void cpuidle_resume(void) |
| 225 | { |
| 226 | mutex_lock(&cpuidle_lock); |
| 227 | cpuidle_install_idle_handler(); |
| 228 | mutex_unlock(&cpuidle_lock); |
| 229 | } |
| 230 | |
Robert Lee | e168979 | 2012-03-20 15:22:42 -0500 | [diff] [blame] | 231 | /** |
| 232 | * cpuidle_wrap_enter - performs timekeeping and irqen around enter function |
| 233 | * @dev: pointer to a valid cpuidle_device object |
| 234 | * @drv: pointer to a valid cpuidle_driver object |
| 235 | * @index: index of the target cpuidle state. |
| 236 | */ |
| 237 | int cpuidle_wrap_enter(struct cpuidle_device *dev, |
| 238 | struct cpuidle_driver *drv, int index, |
| 239 | int (*enter)(struct cpuidle_device *dev, |
| 240 | struct cpuidle_driver *drv, int index)) |
| 241 | { |
| 242 | ktime_t time_start, time_end; |
| 243 | s64 diff; |
| 244 | |
| 245 | time_start = ktime_get(); |
| 246 | |
| 247 | index = enter(dev, drv, index); |
| 248 | |
| 249 | time_end = ktime_get(); |
| 250 | |
| 251 | local_irq_enable(); |
| 252 | |
| 253 | diff = ktime_to_us(ktime_sub(time_end, time_start)); |
| 254 | if (diff > INT_MAX) |
| 255 | diff = INT_MAX; |
| 256 | |
| 257 | dev->last_residency = (int) diff; |
| 258 | |
| 259 | return index; |
| 260 | } |
| 261 | |
Rafael J. Wysocki | d8c216c | 2011-01-08 00:29:20 +0100 | [diff] [blame] | 262 | #ifdef CONFIG_ARCH_HAS_CPU_RELAX |
Deepthi Dharwar | 46bcfad | 2011-10-28 16:20:42 +0530 | [diff] [blame] | 263 | static int poll_idle(struct cpuidle_device *dev, |
| 264 | struct cpuidle_driver *drv, int index) |
Rafael J. Wysocki | d8c216c | 2011-01-08 00:29:20 +0100 | [diff] [blame] | 265 | { |
| 266 | ktime_t t1, t2; |
| 267 | s64 diff; |
Rafael J. Wysocki | d8c216c | 2011-01-08 00:29:20 +0100 | [diff] [blame] | 268 | |
| 269 | t1 = ktime_get(); |
| 270 | local_irq_enable(); |
| 271 | while (!need_resched()) |
| 272 | cpu_relax(); |
| 273 | |
| 274 | t2 = ktime_get(); |
| 275 | diff = ktime_to_us(ktime_sub(t2, t1)); |
| 276 | if (diff > INT_MAX) |
| 277 | diff = INT_MAX; |
| 278 | |
Deepthi Dharwar | e978aa7 | 2011-10-28 16:20:09 +0530 | [diff] [blame] | 279 | dev->last_residency = (int) diff; |
| 280 | |
| 281 | return index; |
Rafael J. Wysocki | d8c216c | 2011-01-08 00:29:20 +0100 | [diff] [blame] | 282 | } |
| 283 | |
Deepthi Dharwar | 46bcfad | 2011-10-28 16:20:42 +0530 | [diff] [blame] | 284 | static void poll_idle_init(struct cpuidle_driver *drv) |
Rafael J. Wysocki | d8c216c | 2011-01-08 00:29:20 +0100 | [diff] [blame] | 285 | { |
Deepthi Dharwar | 46bcfad | 2011-10-28 16:20:42 +0530 | [diff] [blame] | 286 | struct cpuidle_state *state = &drv->states[0]; |
Rafael J. Wysocki | d8c216c | 2011-01-08 00:29:20 +0100 | [diff] [blame] | 287 | |
Thomas Renninger | 720f1c3 | 2011-01-07 11:29:43 +0100 | [diff] [blame] | 288 | snprintf(state->name, CPUIDLE_NAME_LEN, "POLL"); |
Rafael J. Wysocki | d8c216c | 2011-01-08 00:29:20 +0100 | [diff] [blame] | 289 | snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE"); |
| 290 | state->exit_latency = 0; |
| 291 | state->target_residency = 0; |
| 292 | state->power_usage = -1; |
Len Brown | d247632 | 2011-01-12 02:34:59 -0500 | [diff] [blame] | 293 | state->flags = 0; |
Rafael J. Wysocki | d8c216c | 2011-01-08 00:29:20 +0100 | [diff] [blame] | 294 | state->enter = poll_idle; |
Rafael J. Wysocki | cbc9ef0 | 2012-07-03 19:07:42 +0200 | [diff] [blame] | 295 | state->disabled = false; |
Rafael J. Wysocki | d8c216c | 2011-01-08 00:29:20 +0100 | [diff] [blame] | 296 | } |
| 297 | #else |
Deepthi Dharwar | 46bcfad | 2011-10-28 16:20:42 +0530 | [diff] [blame] | 298 | static void poll_idle_init(struct cpuidle_driver *drv) {} |
Rafael J. Wysocki | d8c216c | 2011-01-08 00:29:20 +0100 | [diff] [blame] | 299 | #endif /* CONFIG_ARCH_HAS_CPU_RELAX */ |
| 300 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 301 | /** |
| 302 | * cpuidle_enable_device - enables idle PM for a CPU |
| 303 | * @dev: the CPU |
| 304 | * |
| 305 | * This function must be called between cpuidle_pause_and_lock and |
| 306 | * cpuidle_resume_and_unlock when used externally. |
| 307 | */ |
| 308 | int cpuidle_enable_device(struct cpuidle_device *dev) |
| 309 | { |
| 310 | int ret, i; |
Robert Lee | e168979 | 2012-03-20 15:22:42 -0500 | [diff] [blame] | 311 | struct cpuidle_driver *drv = cpuidle_get_driver(); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 312 | |
Srivatsa S. Bhat | 1b0a0e9 | 2012-05-04 14:06:02 -0700 | [diff] [blame] | 313 | if (!dev) |
| 314 | return -EINVAL; |
| 315 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 316 | if (dev->enabled) |
| 317 | return 0; |
Robert Lee | e168979 | 2012-03-20 15:22:42 -0500 | [diff] [blame] | 318 | if (!drv || !cpuidle_curr_governor) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 319 | return -EIO; |
| 320 | if (!dev->state_count) |
Daniel Lezcano | fc850f3 | 2012-03-26 14:51:26 +0200 | [diff] [blame] | 321 | dev->state_count = drv->state_count; |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 322 | |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 323 | if (dev->registered == 0) { |
| 324 | ret = __cpuidle_register_device(dev); |
| 325 | if (ret) |
| 326 | return ret; |
| 327 | } |
| 328 | |
Robert Lee | e168979 | 2012-03-20 15:22:42 -0500 | [diff] [blame] | 329 | cpuidle_enter_ops = drv->en_core_tk_irqen ? |
| 330 | cpuidle_enter_tk : cpuidle_enter; |
| 331 | |
| 332 | poll_idle_init(drv); |
Rafael J. Wysocki | d8c216c | 2011-01-08 00:29:20 +0100 | [diff] [blame] | 333 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 334 | if ((ret = cpuidle_add_state_sysfs(dev))) |
| 335 | return ret; |
| 336 | |
| 337 | if (cpuidle_curr_governor->enable && |
Robert Lee | e168979 | 2012-03-20 15:22:42 -0500 | [diff] [blame] | 338 | (ret = cpuidle_curr_governor->enable(drv, dev))) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 339 | goto fail_sysfs; |
| 340 | |
| 341 | for (i = 0; i < dev->state_count; i++) { |
Deepthi Dharwar | 4202735 | 2011-10-28 16:20:33 +0530 | [diff] [blame] | 342 | dev->states_usage[i].usage = 0; |
| 343 | dev->states_usage[i].time = 0; |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 344 | } |
| 345 | dev->last_residency = 0; |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 346 | |
| 347 | smp_wmb(); |
| 348 | |
| 349 | dev->enabled = 1; |
| 350 | |
| 351 | enabled_devices++; |
| 352 | return 0; |
| 353 | |
| 354 | fail_sysfs: |
| 355 | cpuidle_remove_state_sysfs(dev); |
| 356 | |
| 357 | return ret; |
| 358 | } |
| 359 | |
| 360 | EXPORT_SYMBOL_GPL(cpuidle_enable_device); |
| 361 | |
| 362 | /** |
| 363 | * cpuidle_disable_device - disables idle PM for a CPU |
| 364 | * @dev: the CPU |
| 365 | * |
| 366 | * This function must be called between cpuidle_pause_and_lock and |
| 367 | * cpuidle_resume_and_unlock when used externally. |
| 368 | */ |
| 369 | void cpuidle_disable_device(struct cpuidle_device *dev) |
| 370 | { |
Srivatsa S. Bhat | cf31cd1 | 2012-10-08 13:43:08 +0530 | [diff] [blame] | 371 | if (!dev || !dev->enabled) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 372 | return; |
Len Brown | 752138d | 2010-05-22 16:57:26 -0400 | [diff] [blame] | 373 | if (!cpuidle_get_driver() || !cpuidle_curr_governor) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 374 | return; |
| 375 | |
| 376 | dev->enabled = 0; |
| 377 | |
| 378 | if (cpuidle_curr_governor->disable) |
Deepthi Dharwar | 46bcfad | 2011-10-28 16:20:42 +0530 | [diff] [blame] | 379 | cpuidle_curr_governor->disable(cpuidle_get_driver(), dev); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 380 | |
| 381 | cpuidle_remove_state_sysfs(dev); |
| 382 | enabled_devices--; |
| 383 | } |
| 384 | |
| 385 | EXPORT_SYMBOL_GPL(cpuidle_disable_device); |
| 386 | |
| 387 | /** |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 388 | * __cpuidle_register_device - internal register function called before register |
| 389 | * and enable routines |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 390 | * @dev: the cpu |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 391 | * |
| 392 | * cpuidle_lock mutex must be held before this is called |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 393 | */ |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 394 | static int __cpuidle_register_device(struct cpuidle_device *dev) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 395 | { |
| 396 | int ret; |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 397 | struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu); |
Len Brown | 752138d | 2010-05-22 16:57:26 -0400 | [diff] [blame] | 398 | struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver(); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 399 | |
Len Brown | 752138d | 2010-05-22 16:57:26 -0400 | [diff] [blame] | 400 | if (!try_module_get(cpuidle_driver->owner)) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 401 | return -EINVAL; |
| 402 | |
| 403 | init_completion(&dev->kobj_unregister); |
| 404 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 405 | per_cpu(cpuidle_devices, dev->cpu) = dev; |
| 406 | list_add(&dev->device_list, &cpuidle_detected_devices); |
Colin Cross | 3af272a | 2012-05-07 17:57:40 -0700 | [diff] [blame] | 407 | ret = cpuidle_add_sysfs(cpu_dev); |
| 408 | if (ret) |
| 409 | goto err_sysfs; |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 410 | |
Colin Cross | 4126c01 | 2012-05-07 17:57:41 -0700 | [diff] [blame] | 411 | ret = cpuidle_coupled_register_device(dev); |
| 412 | if (ret) |
| 413 | goto err_coupled; |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 414 | |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 415 | dev->registered = 1; |
| 416 | return 0; |
Colin Cross | 3af272a | 2012-05-07 17:57:40 -0700 | [diff] [blame] | 417 | |
Colin Cross | 4126c01 | 2012-05-07 17:57:41 -0700 | [diff] [blame] | 418 | err_coupled: |
| 419 | cpuidle_remove_sysfs(cpu_dev); |
| 420 | wait_for_completion(&dev->kobj_unregister); |
Colin Cross | 3af272a | 2012-05-07 17:57:40 -0700 | [diff] [blame] | 421 | err_sysfs: |
| 422 | list_del(&dev->device_list); |
| 423 | per_cpu(cpuidle_devices, dev->cpu) = NULL; |
| 424 | module_put(cpuidle_driver->owner); |
| 425 | return ret; |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 426 | } |
| 427 | |
| 428 | /** |
| 429 | * cpuidle_register_device - registers a CPU's idle PM feature |
| 430 | * @dev: the cpu |
| 431 | */ |
| 432 | int cpuidle_register_device(struct cpuidle_device *dev) |
| 433 | { |
| 434 | int ret; |
| 435 | |
Srivatsa S. Bhat | 1b0a0e9 | 2012-05-04 14:06:02 -0700 | [diff] [blame] | 436 | if (!dev) |
| 437 | return -EINVAL; |
| 438 | |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 439 | mutex_lock(&cpuidle_lock); |
| 440 | |
| 441 | if ((ret = __cpuidle_register_device(dev))) { |
| 442 | mutex_unlock(&cpuidle_lock); |
| 443 | return ret; |
| 444 | } |
| 445 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 446 | cpuidle_enable_device(dev); |
| 447 | cpuidle_install_idle_handler(); |
| 448 | |
| 449 | mutex_unlock(&cpuidle_lock); |
| 450 | |
| 451 | return 0; |
| 452 | |
| 453 | } |
| 454 | |
| 455 | EXPORT_SYMBOL_GPL(cpuidle_register_device); |
| 456 | |
| 457 | /** |
| 458 | * cpuidle_unregister_device - unregisters a CPU's idle PM feature |
| 459 | * @dev: the cpu |
| 460 | */ |
| 461 | void cpuidle_unregister_device(struct cpuidle_device *dev) |
| 462 | { |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 463 | struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu); |
Len Brown | 752138d | 2010-05-22 16:57:26 -0400 | [diff] [blame] | 464 | struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver(); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 465 | |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 466 | if (dev->registered == 0) |
| 467 | return; |
| 468 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 469 | cpuidle_pause_and_lock(); |
| 470 | |
| 471 | cpuidle_disable_device(dev); |
| 472 | |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 473 | cpuidle_remove_sysfs(cpu_dev); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 474 | list_del(&dev->device_list); |
| 475 | wait_for_completion(&dev->kobj_unregister); |
| 476 | per_cpu(cpuidle_devices, dev->cpu) = NULL; |
| 477 | |
Colin Cross | 4126c01 | 2012-05-07 17:57:41 -0700 | [diff] [blame] | 478 | cpuidle_coupled_unregister_device(dev); |
| 479 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 480 | cpuidle_resume_and_unlock(); |
| 481 | |
Len Brown | 752138d | 2010-05-22 16:57:26 -0400 | [diff] [blame] | 482 | module_put(cpuidle_driver->owner); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 483 | } |
| 484 | |
| 485 | EXPORT_SYMBOL_GPL(cpuidle_unregister_device); |
| 486 | |
| 487 | #ifdef CONFIG_SMP |
| 488 | |
| 489 | static void smp_callback(void *v) |
| 490 | { |
| 491 | /* we already woke the CPU up, nothing more to do */ |
| 492 | } |
| 493 | |
| 494 | /* |
| 495 | * This function gets called when a part of the kernel has a new latency |
| 496 | * requirement. This means we need to get all processors out of their C-state, |
| 497 | * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that |
| 498 | * wakes them all right up. |
| 499 | */ |
| 500 | static int cpuidle_latency_notify(struct notifier_block *b, |
| 501 | unsigned long l, void *v) |
| 502 | { |
Jens Axboe | 8691e5a | 2008-06-06 11:18:06 +0200 | [diff] [blame] | 503 | smp_call_function(smp_callback, NULL, 1); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 504 | return NOTIFY_OK; |
| 505 | } |
| 506 | |
| 507 | static struct notifier_block cpuidle_latency_notifier = { |
| 508 | .notifier_call = cpuidle_latency_notify, |
| 509 | }; |
| 510 | |
Mark Gross | d82b351 | 2008-02-04 22:30:08 -0800 | [diff] [blame] | 511 | static inline void latency_notifier_init(struct notifier_block *n) |
| 512 | { |
| 513 | pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n); |
| 514 | } |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 515 | |
| 516 | #else /* CONFIG_SMP */ |
| 517 | |
| 518 | #define latency_notifier_init(x) do { } while (0) |
| 519 | |
| 520 | #endif /* CONFIG_SMP */ |
| 521 | |
| 522 | /** |
| 523 | * cpuidle_init - core initializer |
| 524 | */ |
| 525 | static int __init cpuidle_init(void) |
| 526 | { |
| 527 | int ret; |
| 528 | |
Len Brown | 62027ae | 2011-04-01 18:13:10 -0400 | [diff] [blame] | 529 | if (cpuidle_disabled()) |
| 530 | return -ENODEV; |
| 531 | |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 532 | ret = cpuidle_add_interface(cpu_subsys.dev_root); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 533 | if (ret) |
| 534 | return ret; |
| 535 | |
| 536 | latency_notifier_init(&cpuidle_latency_notifier); |
| 537 | |
| 538 | return 0; |
| 539 | } |
| 540 | |
Len Brown | 62027ae | 2011-04-01 18:13:10 -0400 | [diff] [blame] | 541 | module_param(off, int, 0444); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 542 | core_initcall(cpuidle_init); |