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 | |
Daniel Lezcano | b60e6a0 | 2013-03-21 12:21:31 +0000 | [diff] [blame] | 11 | #include <linux/clockchips.h> |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 12 | #include <linux/kernel.h> |
| 13 | #include <linux/mutex.h> |
| 14 | #include <linux/sched.h> |
| 15 | #include <linux/notifier.h> |
Jean Pihet | e8db0be | 2011-08-25 15:35:03 +0200 | [diff] [blame] | 16 | #include <linux/pm_qos.h> |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 17 | #include <linux/cpu.h> |
| 18 | #include <linux/cpuidle.h> |
venkatesh.pallipadi@intel.com | 9a0b841 | 2008-01-31 17:35:06 -0800 | [diff] [blame] | 19 | #include <linux/ktime.h> |
Arjan van de Ven | 2e94d1f | 2008-09-10 16:06:00 -0700 | [diff] [blame] | 20 | #include <linux/hrtimer.h> |
Paul Gortmaker | 884b17e | 2011-08-29 17:52:39 -0400 | [diff] [blame] | 21 | #include <linux/module.h> |
Rafael J. Wysocki | 3810631 | 2015-02-12 23:33:15 +0100 | [diff] [blame] | 22 | #include <linux/suspend.h> |
Rafael J. Wysocki | 124cf911 | 2015-02-13 23:50:43 +0100 | [diff] [blame] | 23 | #include <linux/tick.h> |
Arjan van de Ven | 288f023 | 2009-09-19 13:35:33 +0200 | [diff] [blame] | 24 | #include <trace/events/power.h> |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 25 | |
| 26 | #include "cpuidle.h" |
| 27 | |
| 28 | DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices); |
Daniel Lezcano | 4c637b2 | 2013-04-23 08:54:33 +0000 | [diff] [blame] | 29 | DEFINE_PER_CPU(struct cpuidle_device, cpuidle_dev); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 30 | |
| 31 | DEFINE_MUTEX(cpuidle_lock); |
| 32 | LIST_HEAD(cpuidle_detected_devices); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 33 | |
| 34 | static int enabled_devices; |
Len Brown | 62027ae | 2011-04-01 18:13:10 -0400 | [diff] [blame] | 35 | static int off __read_mostly; |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 36 | static int initialized __read_mostly; |
Len Brown | 62027ae | 2011-04-01 18:13:10 -0400 | [diff] [blame] | 37 | |
| 38 | int cpuidle_disabled(void) |
| 39 | { |
| 40 | return off; |
| 41 | } |
Len Brown | d91ee58 | 2011-04-01 18:28:35 -0400 | [diff] [blame] | 42 | void disable_cpuidle(void) |
| 43 | { |
| 44 | off = 1; |
| 45 | } |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 46 | |
Rafael J. Wysocki | ef2b22a | 2015-03-02 22:26:55 +0100 | [diff] [blame] | 47 | bool cpuidle_not_available(struct cpuidle_driver *drv, |
| 48 | struct cpuidle_device *dev) |
Rafael J. Wysocki | 31a3409 | 2015-02-27 00:39:56 +0100 | [diff] [blame] | 49 | { |
| 50 | return off || !initialized || !drv || !dev || !dev->enabled; |
| 51 | } |
| 52 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 53 | /** |
Boris Ostrovsky | 1a022e3 | 2012-03-13 19:55:09 +0100 | [diff] [blame] | 54 | * cpuidle_play_dead - cpu off-lining |
| 55 | * |
Toshi Kani | ee01e66 | 2012-03-31 21:37:02 -0600 | [diff] [blame] | 56 | * Returns in case of an error or no driver |
Boris Ostrovsky | 1a022e3 | 2012-03-13 19:55:09 +0100 | [diff] [blame] | 57 | */ |
| 58 | int cpuidle_play_dead(void) |
| 59 | { |
| 60 | struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 61 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
Daniel Lezcano | 8aef33a | 2013-01-15 14:18:04 +0100 | [diff] [blame] | 62 | int i; |
Boris Ostrovsky | 1a022e3 | 2012-03-13 19:55:09 +0100 | [diff] [blame] | 63 | |
Toshi Kani | ee01e66 | 2012-03-31 21:37:02 -0600 | [diff] [blame] | 64 | if (!drv) |
| 65 | return -ENODEV; |
| 66 | |
Boris Ostrovsky | 1a022e3 | 2012-03-13 19:55:09 +0100 | [diff] [blame] | 67 | /* Find lowest-power state that supports long-term idle */ |
Rafael J. Wysocki | 7d51d979 | 2015-05-28 04:09:24 +0200 | [diff] [blame] | 68 | for (i = drv->state_count - 1; i >= 0; i--) |
Daniel Lezcano | 8aef33a | 2013-01-15 14:18:04 +0100 | [diff] [blame] | 69 | if (drv->states[i].enter_dead) |
| 70 | return drv->states[i].enter_dead(dev, i); |
Boris Ostrovsky | 1a022e3 | 2012-03-13 19:55:09 +0100 | [diff] [blame] | 71 | |
| 72 | return -ENODEV; |
| 73 | } |
| 74 | |
Rafael J. Wysocki | ef2b22a | 2015-03-02 22:26:55 +0100 | [diff] [blame] | 75 | static int find_deepest_state(struct cpuidle_driver *drv, |
Rafael J. Wysocki | 0d94039 | 2015-05-10 01:19:52 +0200 | [diff] [blame] | 76 | struct cpuidle_device *dev, |
| 77 | unsigned int max_latency, |
| 78 | unsigned int forbidden_flags, |
| 79 | bool freeze) |
Rafael J. Wysocki | a6220fc | 2014-05-05 00:51:54 +0200 | [diff] [blame] | 80 | { |
| 81 | unsigned int latency_req = 0; |
Rafael J. Wysocki | 5116425 | 2016-01-16 00:54:53 +0100 | [diff] [blame] | 82 | int i, ret = 0; |
Rafael J. Wysocki | a6220fc | 2014-05-05 00:51:54 +0200 | [diff] [blame] | 83 | |
Rafael J. Wysocki | 5116425 | 2016-01-16 00:54:53 +0100 | [diff] [blame] | 84 | for (i = 1; i < drv->state_count; i++) { |
Rafael J. Wysocki | a6220fc | 2014-05-05 00:51:54 +0200 | [diff] [blame] | 85 | struct cpuidle_state *s = &drv->states[i]; |
| 86 | struct cpuidle_state_usage *su = &dev->states_usage[i]; |
| 87 | |
Rafael J. Wysocki | 124cf911 | 2015-02-13 23:50:43 +0100 | [diff] [blame] | 88 | if (s->disabled || su->disable || s->exit_latency <= latency_req |
Rafael J. Wysocki | 0d94039 | 2015-05-10 01:19:52 +0200 | [diff] [blame] | 89 | || s->exit_latency > max_latency |
| 90 | || (s->flags & forbidden_flags) |
Rafael J. Wysocki | 124cf911 | 2015-02-13 23:50:43 +0100 | [diff] [blame] | 91 | || (freeze && !s->enter_freeze)) |
Rafael J. Wysocki | a6220fc | 2014-05-05 00:51:54 +0200 | [diff] [blame] | 92 | continue; |
| 93 | |
| 94 | latency_req = s->exit_latency; |
| 95 | ret = i; |
| 96 | } |
| 97 | return ret; |
| 98 | } |
| 99 | |
Rafael J. Wysocki | 87e9b9f | 2015-05-16 01:38:15 +0200 | [diff] [blame] | 100 | #ifdef CONFIG_SUSPEND |
Rafael J. Wysocki | ef2b22a | 2015-03-02 22:26:55 +0100 | [diff] [blame] | 101 | /** |
| 102 | * cpuidle_find_deepest_state - Find the deepest available idle state. |
| 103 | * @drv: cpuidle driver for the given CPU. |
| 104 | * @dev: cpuidle device for the given CPU. |
| 105 | */ |
| 106 | int cpuidle_find_deepest_state(struct cpuidle_driver *drv, |
| 107 | struct cpuidle_device *dev) |
| 108 | { |
Rafael J. Wysocki | 0d94039 | 2015-05-10 01:19:52 +0200 | [diff] [blame] | 109 | return find_deepest_state(drv, dev, UINT_MAX, 0, false); |
Rafael J. Wysocki | ef2b22a | 2015-03-02 22:26:55 +0100 | [diff] [blame] | 110 | } |
| 111 | |
Rafael J. Wysocki | 124cf911 | 2015-02-13 23:50:43 +0100 | [diff] [blame] | 112 | static void enter_freeze_proper(struct cpuidle_driver *drv, |
| 113 | struct cpuidle_device *dev, int index) |
| 114 | { |
Rafael J. Wysocki | ae0afb4 | 2015-07-09 22:59:49 +0200 | [diff] [blame] | 115 | /* |
| 116 | * trace_suspend_resume() called by tick_freeze() for the last CPU |
| 117 | * executing it contains RCU usage regarded as invalid in the idle |
| 118 | * context, so tell RCU about that. |
| 119 | */ |
| 120 | RCU_NONIDLE(tick_freeze()); |
Rafael J. Wysocki | 124cf911 | 2015-02-13 23:50:43 +0100 | [diff] [blame] | 121 | /* |
| 122 | * The state used here cannot be a "coupled" one, because the "coupled" |
| 123 | * cpuidle mechanism enables interrupts and doing that with timekeeping |
| 124 | * suspended is generally unsafe. |
| 125 | */ |
Lucas Stach | 63caae8 | 2015-07-20 18:34:50 +0200 | [diff] [blame] | 126 | stop_critical_timings(); |
Rafael J. Wysocki | 124cf911 | 2015-02-13 23:50:43 +0100 | [diff] [blame] | 127 | drv->states[index].enter_freeze(dev, drv, index); |
| 128 | WARN_ON(!irqs_disabled()); |
| 129 | /* |
| 130 | * timekeeping_resume() that will be called by tick_unfreeze() for the |
Rafael J. Wysocki | ae0afb4 | 2015-07-09 22:59:49 +0200 | [diff] [blame] | 131 | * first CPU executing it calls functions containing RCU read-side |
Rafael J. Wysocki | 124cf911 | 2015-02-13 23:50:43 +0100 | [diff] [blame] | 132 | * critical sections, so tell RCU about that. |
| 133 | */ |
| 134 | RCU_NONIDLE(tick_unfreeze()); |
Lucas Stach | 63caae8 | 2015-07-20 18:34:50 +0200 | [diff] [blame] | 135 | start_critical_timings(); |
Rafael J. Wysocki | 124cf911 | 2015-02-13 23:50:43 +0100 | [diff] [blame] | 136 | } |
| 137 | |
Rafael J. Wysocki | a6220fc | 2014-05-05 00:51:54 +0200 | [diff] [blame] | 138 | /** |
Rafael J. Wysocki | 3810631 | 2015-02-12 23:33:15 +0100 | [diff] [blame] | 139 | * cpuidle_enter_freeze - Enter an idle state suitable for suspend-to-idle. |
Rafael J. Wysocki | ef2b22a | 2015-03-02 22:26:55 +0100 | [diff] [blame] | 140 | * @drv: cpuidle driver for the given CPU. |
| 141 | * @dev: cpuidle device for the given CPU. |
Rafael J. Wysocki | 3810631 | 2015-02-12 23:33:15 +0100 | [diff] [blame] | 142 | * |
Rafael J. Wysocki | 124cf911 | 2015-02-13 23:50:43 +0100 | [diff] [blame] | 143 | * If there are states with the ->enter_freeze callback, find the deepest of |
Rafael J. Wysocki | ef2b22a | 2015-03-02 22:26:55 +0100 | [diff] [blame] | 144 | * them and enter it with frozen tick. |
Rafael J. Wysocki | 3810631 | 2015-02-12 23:33:15 +0100 | [diff] [blame] | 145 | */ |
Rafael J. Wysocki | ef2b22a | 2015-03-02 22:26:55 +0100 | [diff] [blame] | 146 | int cpuidle_enter_freeze(struct cpuidle_driver *drv, struct cpuidle_device *dev) |
Rafael J. Wysocki | 3810631 | 2015-02-12 23:33:15 +0100 | [diff] [blame] | 147 | { |
Rafael J. Wysocki | 3810631 | 2015-02-12 23:33:15 +0100 | [diff] [blame] | 148 | int index; |
| 149 | |
Rafael J. Wysocki | 124cf911 | 2015-02-13 23:50:43 +0100 | [diff] [blame] | 150 | /* |
| 151 | * Find the deepest state with ->enter_freeze present, which guarantees |
| 152 | * that interrupts won't be enabled when it exits and allows the tick to |
| 153 | * be frozen safely. |
| 154 | */ |
Rafael J. Wysocki | 0d94039 | 2015-05-10 01:19:52 +0200 | [diff] [blame] | 155 | index = find_deepest_state(drv, dev, UINT_MAX, 0, true); |
Sudeep Holla | 6f16886 | 2016-01-21 11:19:29 +0000 | [diff] [blame] | 156 | if (index > 0) |
Rafael J. Wysocki | 124cf911 | 2015-02-13 23:50:43 +0100 | [diff] [blame] | 157 | enter_freeze_proper(drv, dev, index); |
Rafael J. Wysocki | 124cf911 | 2015-02-13 23:50:43 +0100 | [diff] [blame] | 158 | |
Rafael J. Wysocki | ef2b22a | 2015-03-02 22:26:55 +0100 | [diff] [blame] | 159 | return index; |
Rafael J. Wysocki | 3810631 | 2015-02-12 23:33:15 +0100 | [diff] [blame] | 160 | } |
Rafael J. Wysocki | 87e9b9f | 2015-05-16 01:38:15 +0200 | [diff] [blame] | 161 | #endif /* CONFIG_SUSPEND */ |
Rafael J. Wysocki | 3810631 | 2015-02-12 23:33:15 +0100 | [diff] [blame] | 162 | |
| 163 | /** |
Colin Cross | 56cfbf7 | 2012-05-07 17:57:39 -0700 | [diff] [blame] | 164 | * cpuidle_enter_state - enter the state and update stats |
| 165 | * @dev: cpuidle device for this cpu |
| 166 | * @drv: cpuidle driver for this cpu |
Rafael J. Wysocki | 7312280 | 2015-05-09 21:50:32 +0200 | [diff] [blame] | 167 | * @index: index into the states table in @drv of the state to enter |
Colin Cross | 56cfbf7 | 2012-05-07 17:57:39 -0700 | [diff] [blame] | 168 | */ |
| 169 | int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, |
Daniel Lezcano | 554c06b | 2013-04-23 08:54:31 +0000 | [diff] [blame] | 170 | int index) |
Colin Cross | 56cfbf7 | 2012-05-07 17:57:39 -0700 | [diff] [blame] | 171 | { |
| 172 | int entered_state; |
| 173 | |
Daniel Lezcano | 554c06b | 2013-04-23 08:54:31 +0000 | [diff] [blame] | 174 | struct cpuidle_state *target_state = &drv->states[index]; |
Rafael J. Wysocki | df8d9ee | 2015-04-29 15:19:21 +0200 | [diff] [blame] | 175 | bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP); |
Daniel Lezcano | e93e59c | 2016-04-21 10:56:30 +0200 | [diff] [blame] | 176 | u64 time_start, time_end; |
Daniel Lezcano | 554c06b | 2013-04-23 08:54:31 +0000 | [diff] [blame] | 177 | s64 diff; |
| 178 | |
Rafael J. Wysocki | df8d9ee | 2015-04-29 15:19:21 +0200 | [diff] [blame] | 179 | /* |
| 180 | * Tell the time framework to switch to a broadcast timer because our |
| 181 | * local timer will be shut down. If a local timer is used from another |
| 182 | * CPU as a broadcast timer, this call may fail if it is not available. |
| 183 | */ |
Rafael J. Wysocki | 827a5ae | 2015-05-10 01:18:46 +0200 | [diff] [blame] | 184 | if (broadcast && tick_broadcast_enter()) { |
Rafael J. Wysocki | 0d94039 | 2015-05-10 01:19:52 +0200 | [diff] [blame] | 185 | index = find_deepest_state(drv, dev, target_state->exit_latency, |
| 186 | CPUIDLE_FLAG_TIMER_STOP, false); |
| 187 | if (index < 0) { |
| 188 | default_idle_call(); |
| 189 | return -EBUSY; |
| 190 | } |
| 191 | target_state = &drv->states[index]; |
Rafael J. Wysocki | 827a5ae | 2015-05-10 01:18:46 +0200 | [diff] [blame] | 192 | } |
Rafael J. Wysocki | df8d9ee | 2015-04-29 15:19:21 +0200 | [diff] [blame] | 193 | |
Rafael J. Wysocki | faad384 | 2015-05-10 01:18:03 +0200 | [diff] [blame] | 194 | /* Take note of the planned idle state. */ |
| 195 | sched_idle_set_state(target_state); |
| 196 | |
Sandeep Tripathy | 30fe688 | 2014-07-02 15:00:58 +0530 | [diff] [blame] | 197 | trace_cpu_idle_rcuidle(index, dev->cpu); |
Daniel Lezcano | e93e59c | 2016-04-21 10:56:30 +0200 | [diff] [blame] | 198 | time_start = local_clock(); |
Daniel Lezcano | 554c06b | 2013-04-23 08:54:31 +0000 | [diff] [blame] | 199 | |
Lucas Stach | 63caae8 | 2015-07-20 18:34:50 +0200 | [diff] [blame] | 200 | stop_critical_timings(); |
Daniel Lezcano | 554c06b | 2013-04-23 08:54:31 +0000 | [diff] [blame] | 201 | entered_state = target_state->enter(dev, drv, index); |
Lucas Stach | 63caae8 | 2015-07-20 18:34:50 +0200 | [diff] [blame] | 202 | start_critical_timings(); |
Daniel Lezcano | 554c06b | 2013-04-23 08:54:31 +0000 | [diff] [blame] | 203 | |
Daniel Lezcano | e93e59c | 2016-04-21 10:56:30 +0200 | [diff] [blame] | 204 | time_end = local_clock(); |
Sandeep Tripathy | 30fe688 | 2014-07-02 15:00:58 +0530 | [diff] [blame] | 205 | trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); |
Daniel Lezcano | 554c06b | 2013-04-23 08:54:31 +0000 | [diff] [blame] | 206 | |
Rafael J. Wysocki | faad384 | 2015-05-10 01:18:03 +0200 | [diff] [blame] | 207 | /* The cpu is no longer idle or about to enter idle. */ |
| 208 | sched_idle_set_state(NULL); |
| 209 | |
Rafael J. Wysocki | df8d9ee | 2015-04-29 15:19:21 +0200 | [diff] [blame] | 210 | if (broadcast) { |
| 211 | if (WARN_ON_ONCE(!irqs_disabled())) |
| 212 | local_irq_disable(); |
| 213 | |
| 214 | tick_broadcast_exit(); |
| 215 | } |
| 216 | |
Daniel Lezcano | e7387da | 2016-05-17 16:54:00 +0200 | [diff] [blame] | 217 | if (!cpuidle_state_is_coupled(drv, index)) |
Paul Burton | 0b89e9a | 2014-03-06 11:02:01 +0000 | [diff] [blame] | 218 | local_irq_enable(); |
Daniel Lezcano | 554c06b | 2013-04-23 08:54:31 +0000 | [diff] [blame] | 219 | |
Daniel Lezcano | e93e59c | 2016-04-21 10:56:30 +0200 | [diff] [blame] | 220 | /* |
| 221 | * local_clock() returns the time in nanosecond, let's shift |
| 222 | * by 10 (divide by 1024) to have microsecond based time. |
| 223 | */ |
| 224 | diff = (time_end - time_start) >> 10; |
Daniel Lezcano | 554c06b | 2013-04-23 08:54:31 +0000 | [diff] [blame] | 225 | if (diff > INT_MAX) |
| 226 | diff = INT_MAX; |
| 227 | |
| 228 | dev->last_residency = (int) diff; |
Colin Cross | 56cfbf7 | 2012-05-07 17:57:39 -0700 | [diff] [blame] | 229 | |
| 230 | if (entered_state >= 0) { |
| 231 | /* Update cpuidle counters */ |
| 232 | /* This can be moved to within driver enter routine |
| 233 | * but that results in multiple copies of same code. |
| 234 | */ |
Julius Werner | a474a51 | 2012-11-27 14:17:58 +0100 | [diff] [blame] | 235 | dev->states_usage[entered_state].time += dev->last_residency; |
Colin Cross | 56cfbf7 | 2012-05-07 17:57:39 -0700 | [diff] [blame] | 236 | dev->states_usage[entered_state].usage++; |
| 237 | } else { |
| 238 | dev->last_residency = 0; |
| 239 | } |
| 240 | |
| 241 | return entered_state; |
| 242 | } |
| 243 | |
| 244 | /** |
Daniel Lezcano | 907e30f | 2014-03-03 08:48:50 +0100 | [diff] [blame] | 245 | * cpuidle_select - ask the cpuidle framework to choose an idle state |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 246 | * |
Daniel Lezcano | 907e30f | 2014-03-03 08:48:50 +0100 | [diff] [blame] | 247 | * @drv: the cpuidle driver |
| 248 | * @dev: the cpuidle device |
| 249 | * |
Rafael J. Wysocki | 5116425 | 2016-01-16 00:54:53 +0100 | [diff] [blame] | 250 | * Returns the index of the idle state. The return value must not be negative. |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 251 | */ |
Daniel Lezcano | 907e30f | 2014-03-03 08:48:50 +0100 | [diff] [blame] | 252 | int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 253 | { |
Daniel Lezcano | 907e30f | 2014-03-03 08:48:50 +0100 | [diff] [blame] | 254 | return cpuidle_curr_governor->select(drv, dev); |
| 255 | } |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 256 | |
Daniel Lezcano | 907e30f | 2014-03-03 08:48:50 +0100 | [diff] [blame] | 257 | /** |
| 258 | * cpuidle_enter - enter into the specified idle state |
| 259 | * |
| 260 | * @drv: the cpuidle driver tied with the cpu |
| 261 | * @dev: the cpuidle device |
| 262 | * @index: the index in the idle state table |
| 263 | * |
| 264 | * Returns the index in the idle state, < 0 in case of error. |
| 265 | * The error code depends on the backend driver |
| 266 | */ |
| 267 | int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, |
| 268 | int index) |
| 269 | { |
Xunlei Pang | 4c1ed5a | 2015-08-04 13:48:56 +0800 | [diff] [blame] | 270 | if (cpuidle_state_is_coupled(drv, index)) |
Daniel Lezcano | 907e30f | 2014-03-03 08:48:50 +0100 | [diff] [blame] | 271 | return cpuidle_enter_state_coupled(dev, drv, index); |
| 272 | return cpuidle_enter_state(dev, drv, index); |
| 273 | } |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 274 | |
Daniel Lezcano | 907e30f | 2014-03-03 08:48:50 +0100 | [diff] [blame] | 275 | /** |
| 276 | * cpuidle_reflect - tell the underlying governor what was the state |
| 277 | * we were in |
| 278 | * |
| 279 | * @dev : the cpuidle device |
| 280 | * @index: the index in the idle state table |
| 281 | * |
| 282 | */ |
| 283 | void cpuidle_reflect(struct cpuidle_device *dev, int index) |
| 284 | { |
Rafael J. Wysocki | a802ea9 | 2015-05-04 22:53:28 +0200 | [diff] [blame] | 285 | if (cpuidle_curr_governor->reflect && index >= 0) |
Daniel Lezcano | 907e30f | 2014-03-03 08:48:50 +0100 | [diff] [blame] | 286 | cpuidle_curr_governor->reflect(dev, index); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 287 | } |
| 288 | |
| 289 | /** |
| 290 | * cpuidle_install_idle_handler - installs the cpuidle idle loop handler |
| 291 | */ |
| 292 | void cpuidle_install_idle_handler(void) |
| 293 | { |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 294 | if (enabled_devices) { |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 295 | /* Make sure all changes finished before we switch to new idle */ |
| 296 | smp_wmb(); |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 297 | initialized = 1; |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 298 | } |
| 299 | } |
| 300 | |
| 301 | /** |
| 302 | * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler |
| 303 | */ |
| 304 | void cpuidle_uninstall_idle_handler(void) |
| 305 | { |
Len Brown | a0bfa13 | 2011-04-01 19:34:59 -0400 | [diff] [blame] | 306 | if (enabled_devices) { |
| 307 | initialized = 0; |
Chuansheng Liu | 2ed903c | 2014-09-04 15:17:55 +0800 | [diff] [blame] | 308 | wake_up_all_idle_cpus(); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 309 | } |
Daniel Lezcano | 442bf3a | 2014-09-04 11:32:09 -0400 | [diff] [blame] | 310 | |
| 311 | /* |
| 312 | * Make sure external observers (such as the scheduler) |
| 313 | * are done looking at pointed idle states. |
| 314 | */ |
| 315 | synchronize_rcu(); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 316 | } |
| 317 | |
| 318 | /** |
| 319 | * cpuidle_pause_and_lock - temporarily disables CPUIDLE |
| 320 | */ |
| 321 | void cpuidle_pause_and_lock(void) |
| 322 | { |
| 323 | mutex_lock(&cpuidle_lock); |
| 324 | cpuidle_uninstall_idle_handler(); |
| 325 | } |
| 326 | |
| 327 | EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock); |
| 328 | |
| 329 | /** |
| 330 | * cpuidle_resume_and_unlock - resumes CPUIDLE operation |
| 331 | */ |
| 332 | void cpuidle_resume_and_unlock(void) |
| 333 | { |
| 334 | cpuidle_install_idle_handler(); |
| 335 | mutex_unlock(&cpuidle_lock); |
| 336 | } |
| 337 | |
| 338 | EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock); |
| 339 | |
Preeti U Murthy | 8651f97 | 2012-07-09 10:12:56 +0200 | [diff] [blame] | 340 | /* Currently used in suspend/resume path to suspend cpuidle */ |
| 341 | void cpuidle_pause(void) |
| 342 | { |
| 343 | mutex_lock(&cpuidle_lock); |
| 344 | cpuidle_uninstall_idle_handler(); |
| 345 | mutex_unlock(&cpuidle_lock); |
| 346 | } |
| 347 | |
| 348 | /* Currently used in suspend/resume path to resume cpuidle */ |
| 349 | void cpuidle_resume(void) |
| 350 | { |
| 351 | mutex_lock(&cpuidle_lock); |
| 352 | cpuidle_install_idle_handler(); |
| 353 | mutex_unlock(&cpuidle_lock); |
| 354 | } |
| 355 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 356 | /** |
| 357 | * cpuidle_enable_device - enables idle PM for a CPU |
| 358 | * @dev: the CPU |
| 359 | * |
| 360 | * This function must be called between cpuidle_pause_and_lock and |
| 361 | * cpuidle_resume_and_unlock when used externally. |
| 362 | */ |
| 363 | int cpuidle_enable_device(struct cpuidle_device *dev) |
| 364 | { |
Daniel Lezcano | 5df0aa7 | 2013-06-12 15:08:54 +0200 | [diff] [blame] | 365 | int ret; |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 366 | struct cpuidle_driver *drv; |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 367 | |
Srivatsa S. Bhat | 1b0a0e9 | 2012-05-04 14:06:02 -0700 | [diff] [blame] | 368 | if (!dev) |
| 369 | return -EINVAL; |
| 370 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 371 | if (dev->enabled) |
| 372 | return 0; |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 373 | |
| 374 | drv = cpuidle_get_cpu_driver(dev); |
| 375 | |
Robert Lee | e168979 | 2012-03-20 15:22:42 -0500 | [diff] [blame] | 376 | if (!drv || !cpuidle_curr_governor) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 377 | return -EIO; |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 378 | |
Daniel Lezcano | 10b9d3f | 2013-06-12 15:08:49 +0200 | [diff] [blame] | 379 | if (!dev->registered) |
| 380 | return -EINVAL; |
| 381 | |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 382 | ret = cpuidle_add_device_sysfs(dev); |
| 383 | if (ret) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 384 | return ret; |
| 385 | |
| 386 | if (cpuidle_curr_governor->enable && |
Robert Lee | e168979 | 2012-03-20 15:22:42 -0500 | [diff] [blame] | 387 | (ret = cpuidle_curr_governor->enable(drv, dev))) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 388 | goto fail_sysfs; |
| 389 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 390 | smp_wmb(); |
| 391 | |
| 392 | dev->enabled = 1; |
| 393 | |
| 394 | enabled_devices++; |
| 395 | return 0; |
| 396 | |
| 397 | fail_sysfs: |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 398 | cpuidle_remove_device_sysfs(dev); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 399 | |
| 400 | return ret; |
| 401 | } |
| 402 | |
| 403 | EXPORT_SYMBOL_GPL(cpuidle_enable_device); |
| 404 | |
| 405 | /** |
| 406 | * cpuidle_disable_device - disables idle PM for a CPU |
| 407 | * @dev: the CPU |
| 408 | * |
| 409 | * This function must be called between cpuidle_pause_and_lock and |
| 410 | * cpuidle_resume_and_unlock when used externally. |
| 411 | */ |
| 412 | void cpuidle_disable_device(struct cpuidle_device *dev) |
| 413 | { |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 414 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
| 415 | |
Srivatsa S. Bhat | cf31cd1 | 2012-10-08 13:43:08 +0530 | [diff] [blame] | 416 | if (!dev || !dev->enabled) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 417 | return; |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 418 | |
| 419 | if (!drv || !cpuidle_curr_governor) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 420 | return; |
| 421 | |
| 422 | dev->enabled = 0; |
| 423 | |
| 424 | if (cpuidle_curr_governor->disable) |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 425 | cpuidle_curr_governor->disable(drv, dev); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 426 | |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 427 | cpuidle_remove_device_sysfs(dev); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 428 | enabled_devices--; |
| 429 | } |
| 430 | |
| 431 | EXPORT_SYMBOL_GPL(cpuidle_disable_device); |
| 432 | |
Daniel Lezcano | f6bb51a | 2013-06-12 15:08:53 +0200 | [diff] [blame] | 433 | static void __cpuidle_unregister_device(struct cpuidle_device *dev) |
| 434 | { |
| 435 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
| 436 | |
| 437 | list_del(&dev->device_list); |
| 438 | per_cpu(cpuidle_devices, dev->cpu) = NULL; |
| 439 | module_put(drv->owner); |
Dave Gerlach | c998c07 | 2016-04-05 14:05:38 -0500 | [diff] [blame] | 440 | |
| 441 | dev->registered = 0; |
Daniel Lezcano | f6bb51a | 2013-06-12 15:08:53 +0200 | [diff] [blame] | 442 | } |
| 443 | |
Viresh Kumar | 267d4bf | 2013-10-03 21:26:43 +0530 | [diff] [blame] | 444 | static void __cpuidle_device_init(struct cpuidle_device *dev) |
Daniel Lezcano | 5df0aa7 | 2013-06-12 15:08:54 +0200 | [diff] [blame] | 445 | { |
| 446 | memset(dev->states_usage, 0, sizeof(dev->states_usage)); |
| 447 | dev->last_residency = 0; |
Daniel Lezcano | 5df0aa7 | 2013-06-12 15:08:54 +0200 | [diff] [blame] | 448 | } |
| 449 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 450 | /** |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 451 | * __cpuidle_register_device - internal register function called before register |
| 452 | * and enable routines |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 453 | * @dev: the cpu |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 454 | * |
| 455 | * cpuidle_lock mutex must be held before this is called |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 456 | */ |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 457 | static int __cpuidle_register_device(struct cpuidle_device *dev) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 458 | { |
| 459 | int ret; |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 460 | struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 461 | |
Daniel Lezcano | bf4d1b5 | 2012-10-31 16:44:48 +0000 | [diff] [blame] | 462 | if (!try_module_get(drv->owner)) |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 463 | return -EINVAL; |
| 464 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 465 | per_cpu(cpuidle_devices, dev->cpu) = dev; |
| 466 | list_add(&dev->device_list, &cpuidle_detected_devices); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 467 | |
Colin Cross | 4126c01 | 2012-05-07 17:57:41 -0700 | [diff] [blame] | 468 | ret = cpuidle_coupled_register_device(dev); |
Viresh Kumar | 4718266 | 2013-10-03 21:26:46 +0530 | [diff] [blame] | 469 | if (ret) |
Daniel Lezcano | f6bb51a | 2013-06-12 15:08:53 +0200 | [diff] [blame] | 470 | __cpuidle_unregister_device(dev); |
Viresh Kumar | 4718266 | 2013-10-03 21:26:46 +0530 | [diff] [blame] | 471 | else |
| 472 | dev->registered = 1; |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 473 | |
Viresh Kumar | 4718266 | 2013-10-03 21:26:46 +0530 | [diff] [blame] | 474 | return ret; |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 475 | } |
| 476 | |
| 477 | /** |
| 478 | * cpuidle_register_device - registers a CPU's idle PM feature |
| 479 | * @dev: the cpu |
| 480 | */ |
| 481 | int cpuidle_register_device(struct cpuidle_device *dev) |
| 482 | { |
Daniel Lezcano | c878a52 | 2013-06-12 15:08:55 +0200 | [diff] [blame] | 483 | int ret = -EBUSY; |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 484 | |
Srivatsa S. Bhat | 1b0a0e9 | 2012-05-04 14:06:02 -0700 | [diff] [blame] | 485 | if (!dev) |
| 486 | return -EINVAL; |
| 487 | |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 488 | mutex_lock(&cpuidle_lock); |
| 489 | |
Daniel Lezcano | c878a52 | 2013-06-12 15:08:55 +0200 | [diff] [blame] | 490 | if (dev->registered) |
| 491 | goto out_unlock; |
| 492 | |
Viresh Kumar | 267d4bf | 2013-10-03 21:26:43 +0530 | [diff] [blame] | 493 | __cpuidle_device_init(dev); |
Daniel Lezcano | 5df0aa7 | 2013-06-12 15:08:54 +0200 | [diff] [blame] | 494 | |
Daniel Lezcano | f6bb51a | 2013-06-12 15:08:53 +0200 | [diff] [blame] | 495 | ret = __cpuidle_register_device(dev); |
| 496 | if (ret) |
| 497 | goto out_unlock; |
| 498 | |
| 499 | ret = cpuidle_add_sysfs(dev); |
| 500 | if (ret) |
| 501 | goto out_unregister; |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 502 | |
Daniel Lezcano | 10b9d3f | 2013-06-12 15:08:49 +0200 | [diff] [blame] | 503 | ret = cpuidle_enable_device(dev); |
Daniel Lezcano | f6bb51a | 2013-06-12 15:08:53 +0200 | [diff] [blame] | 504 | if (ret) |
| 505 | goto out_sysfs; |
Daniel Lezcano | 10b9d3f | 2013-06-12 15:08:49 +0200 | [diff] [blame] | 506 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 507 | cpuidle_install_idle_handler(); |
| 508 | |
Daniel Lezcano | f6bb51a | 2013-06-12 15:08:53 +0200 | [diff] [blame] | 509 | out_unlock: |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 510 | mutex_unlock(&cpuidle_lock); |
| 511 | |
Daniel Lezcano | f6bb51a | 2013-06-12 15:08:53 +0200 | [diff] [blame] | 512 | return ret; |
| 513 | |
| 514 | out_sysfs: |
| 515 | cpuidle_remove_sysfs(dev); |
| 516 | out_unregister: |
| 517 | __cpuidle_unregister_device(dev); |
| 518 | goto out_unlock; |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 519 | } |
| 520 | |
| 521 | EXPORT_SYMBOL_GPL(cpuidle_register_device); |
| 522 | |
| 523 | /** |
| 524 | * cpuidle_unregister_device - unregisters a CPU's idle PM feature |
| 525 | * @dev: the cpu |
| 526 | */ |
| 527 | void cpuidle_unregister_device(struct cpuidle_device *dev) |
| 528 | { |
Konrad Rzeszutek Wilk | 813e8e3 | 2013-12-03 10:59:58 -0500 | [diff] [blame] | 529 | if (!dev || dev->registered == 0) |
Venkatesh Pallipadi | dcb84f3 | 2008-05-19 19:09:27 -0400 | [diff] [blame] | 530 | return; |
| 531 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 532 | cpuidle_pause_and_lock(); |
| 533 | |
| 534 | cpuidle_disable_device(dev); |
| 535 | |
Daniel Lezcano | 1aef40e | 2012-10-26 12:26:24 +0200 | [diff] [blame] | 536 | cpuidle_remove_sysfs(dev); |
Daniel Lezcano | f6bb51a | 2013-06-12 15:08:53 +0200 | [diff] [blame] | 537 | |
| 538 | __cpuidle_unregister_device(dev); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 539 | |
Colin Cross | 4126c01 | 2012-05-07 17:57:41 -0700 | [diff] [blame] | 540 | cpuidle_coupled_unregister_device(dev); |
| 541 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 542 | cpuidle_resume_and_unlock(); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 543 | } |
| 544 | |
| 545 | EXPORT_SYMBOL_GPL(cpuidle_unregister_device); |
| 546 | |
Daniel Lezcano | 1c192d0 | 2013-04-23 15:28:44 +0000 | [diff] [blame] | 547 | /** |
Daniel Lezcano | 4c637b2 | 2013-04-23 08:54:33 +0000 | [diff] [blame] | 548 | * cpuidle_unregister: unregister a driver and the devices. This function |
| 549 | * can be used only if the driver has been previously registered through |
| 550 | * the cpuidle_register function. |
| 551 | * |
| 552 | * @drv: a valid pointer to a struct cpuidle_driver |
| 553 | */ |
| 554 | void cpuidle_unregister(struct cpuidle_driver *drv) |
| 555 | { |
| 556 | int cpu; |
| 557 | struct cpuidle_device *device; |
| 558 | |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 559 | for_each_cpu(cpu, drv->cpumask) { |
Daniel Lezcano | 4c637b2 | 2013-04-23 08:54:33 +0000 | [diff] [blame] | 560 | device = &per_cpu(cpuidle_dev, cpu); |
| 561 | cpuidle_unregister_device(device); |
| 562 | } |
| 563 | |
| 564 | cpuidle_unregister_driver(drv); |
| 565 | } |
| 566 | EXPORT_SYMBOL_GPL(cpuidle_unregister); |
| 567 | |
| 568 | /** |
| 569 | * cpuidle_register: registers the driver and the cpu devices with the |
| 570 | * coupled_cpus passed as parameter. This function is used for all common |
| 571 | * initialization pattern there are in the arch specific drivers. The |
| 572 | * devices is globally defined in this file. |
| 573 | * |
| 574 | * @drv : a valid pointer to a struct cpuidle_driver |
| 575 | * @coupled_cpus: a cpumask for the coupled states |
| 576 | * |
| 577 | * Returns 0 on success, < 0 otherwise |
| 578 | */ |
| 579 | int cpuidle_register(struct cpuidle_driver *drv, |
| 580 | const struct cpumask *const coupled_cpus) |
| 581 | { |
| 582 | int ret, cpu; |
| 583 | struct cpuidle_device *device; |
| 584 | |
| 585 | ret = cpuidle_register_driver(drv); |
| 586 | if (ret) { |
| 587 | pr_err("failed to register cpuidle driver\n"); |
| 588 | return ret; |
| 589 | } |
| 590 | |
Daniel Lezcano | 82467a5 | 2013-06-07 21:53:09 +0000 | [diff] [blame] | 591 | for_each_cpu(cpu, drv->cpumask) { |
Daniel Lezcano | 4c637b2 | 2013-04-23 08:54:33 +0000 | [diff] [blame] | 592 | device = &per_cpu(cpuidle_dev, cpu); |
| 593 | device->cpu = cpu; |
| 594 | |
| 595 | #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED |
| 596 | /* |
Viresh Kumar | caf4a36 | 2013-10-03 21:26:41 +0530 | [diff] [blame] | 597 | * On multiplatform for ARM, the coupled idle states could be |
Daniel Lezcano | 4c637b2 | 2013-04-23 08:54:33 +0000 | [diff] [blame] | 598 | * enabled in the kernel even if the cpuidle driver does not |
| 599 | * use it. Note, coupled_cpus is a struct copy. |
| 600 | */ |
| 601 | if (coupled_cpus) |
| 602 | device->coupled_cpus = *coupled_cpus; |
| 603 | #endif |
| 604 | ret = cpuidle_register_device(device); |
| 605 | if (!ret) |
| 606 | continue; |
| 607 | |
| 608 | pr_err("Failed to register cpuidle device for cpu%d\n", cpu); |
| 609 | |
| 610 | cpuidle_unregister(drv); |
| 611 | break; |
| 612 | } |
| 613 | |
| 614 | return ret; |
| 615 | } |
| 616 | EXPORT_SYMBOL_GPL(cpuidle_register); |
| 617 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 618 | #ifdef CONFIG_SMP |
| 619 | |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 620 | /* |
| 621 | * This function gets called when a part of the kernel has a new latency |
| 622 | * requirement. This means we need to get all processors out of their C-state, |
| 623 | * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that |
| 624 | * wakes them all right up. |
| 625 | */ |
| 626 | static int cpuidle_latency_notify(struct notifier_block *b, |
| 627 | unsigned long l, void *v) |
| 628 | { |
Chuansheng Liu | 2ed903c | 2014-09-04 15:17:55 +0800 | [diff] [blame] | 629 | wake_up_all_idle_cpus(); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 630 | return NOTIFY_OK; |
| 631 | } |
| 632 | |
| 633 | static struct notifier_block cpuidle_latency_notifier = { |
| 634 | .notifier_call = cpuidle_latency_notify, |
| 635 | }; |
| 636 | |
Mark Gross | d82b351 | 2008-02-04 22:30:08 -0800 | [diff] [blame] | 637 | static inline void latency_notifier_init(struct notifier_block *n) |
| 638 | { |
| 639 | pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n); |
| 640 | } |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 641 | |
| 642 | #else /* CONFIG_SMP */ |
| 643 | |
| 644 | #define latency_notifier_init(x) do { } while (0) |
| 645 | |
| 646 | #endif /* CONFIG_SMP */ |
| 647 | |
| 648 | /** |
| 649 | * cpuidle_init - core initializer |
| 650 | */ |
| 651 | static int __init cpuidle_init(void) |
| 652 | { |
| 653 | int ret; |
| 654 | |
Len Brown | 62027ae | 2011-04-01 18:13:10 -0400 | [diff] [blame] | 655 | if (cpuidle_disabled()) |
| 656 | return -ENODEV; |
| 657 | |
Kay Sievers | 8a25a2f | 2011-12-21 14:29:42 -0800 | [diff] [blame] | 658 | ret = cpuidle_add_interface(cpu_subsys.dev_root); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 659 | if (ret) |
| 660 | return ret; |
| 661 | |
| 662 | latency_notifier_init(&cpuidle_latency_notifier); |
| 663 | |
| 664 | return 0; |
| 665 | } |
| 666 | |
Len Brown | 62027ae | 2011-04-01 18:13:10 -0400 | [diff] [blame] | 667 | module_param(off, int, 0444); |
Len Brown | 4f86d3a | 2007-10-03 18:58:00 -0400 | [diff] [blame] | 668 | core_initcall(cpuidle_init); |