Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* CPU control. |
| 2 | * (C) 2001, 2002, 2003, 2004 Rusty Russell |
| 3 | * |
| 4 | * This code is licenced under the GPL. |
| 5 | */ |
| 6 | #include <linux/proc_fs.h> |
| 7 | #include <linux/smp.h> |
| 8 | #include <linux/init.h> |
| 9 | #include <linux/notifier.h> |
| 10 | #include <linux/sched.h> |
| 11 | #include <linux/unistd.h> |
| 12 | #include <linux/cpu.h> |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 13 | #include <linux/oom.h> |
| 14 | #include <linux/rcupdate.h> |
Paul Gortmaker | 9984de1 | 2011-05-23 14:51:41 -0400 | [diff] [blame] | 15 | #include <linux/export.h> |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 16 | #include <linux/bug.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/kthread.h> |
| 18 | #include <linux/stop_machine.h> |
Ingo Molnar | 81615b6 | 2006-06-26 00:24:32 -0700 | [diff] [blame] | 19 | #include <linux/mutex.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 20 | #include <linux/gfp.h> |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 21 | #include <linux/suspend.h> |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 22 | #include <linux/lockdep.h> |
Preeti U Murthy | 345527b | 2015-03-30 14:59:19 +0530 | [diff] [blame] | 23 | #include <linux/tick.h> |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 24 | #include <linux/irq.h> |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 25 | #include <linux/smpboot.h> |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 26 | |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 27 | #include <trace/events/power.h> |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 28 | #define CREATE_TRACE_POINTS |
| 29 | #include <trace/events/cpuhp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 31 | #include "smpboot.h" |
| 32 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 33 | /** |
| 34 | * cpuhp_cpu_state - Per cpu hotplug state storage |
| 35 | * @state: The current cpu state |
| 36 | * @target: The target state |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 37 | * @thread: Pointer to the hotplug thread |
| 38 | * @should_run: Thread should execute |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 39 | * @rollback: Perform a rollback |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 40 | * @cb_stat: The state for a single callback (install/uninstall) |
| 41 | * @cb: Single callback function (install/uninstall) |
| 42 | * @result: Result of the operation |
| 43 | * @done: Signal completion to the issuer of the task |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 44 | */ |
| 45 | struct cpuhp_cpu_state { |
| 46 | enum cpuhp_state state; |
| 47 | enum cpuhp_state target; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 48 | #ifdef CONFIG_SMP |
| 49 | struct task_struct *thread; |
| 50 | bool should_run; |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 51 | bool rollback; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 52 | enum cpuhp_state cb_state; |
| 53 | int (*cb)(unsigned int cpu); |
| 54 | int result; |
| 55 | struct completion done; |
| 56 | #endif |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 57 | }; |
| 58 | |
| 59 | static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state); |
| 60 | |
| 61 | /** |
| 62 | * cpuhp_step - Hotplug state machine step |
| 63 | * @name: Name of the step |
| 64 | * @startup: Startup function of the step |
| 65 | * @teardown: Teardown function of the step |
| 66 | * @skip_onerr: Do not invoke the functions on error rollback |
| 67 | * Will go away once the notifiers are gone |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 68 | * @cant_stop: Bringup/teardown can't be stopped at this step |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 69 | */ |
| 70 | struct cpuhp_step { |
| 71 | const char *name; |
| 72 | int (*startup)(unsigned int cpu); |
| 73 | int (*teardown)(unsigned int cpu); |
| 74 | bool skip_onerr; |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 75 | bool cant_stop; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 76 | }; |
| 77 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 78 | static DEFINE_MUTEX(cpuhp_state_mutex); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 79 | static struct cpuhp_step cpuhp_bp_states[]; |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 80 | static struct cpuhp_step cpuhp_ap_states[]; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 81 | |
| 82 | /** |
| 83 | * cpuhp_invoke_callback _ Invoke the callbacks for a given state |
| 84 | * @cpu: The cpu for which the callback should be invoked |
| 85 | * @step: The step in the state machine |
| 86 | * @cb: The callback function to invoke |
| 87 | * |
| 88 | * Called from cpu hotplug and from the state register machinery |
| 89 | */ |
| 90 | static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state step, |
| 91 | int (*cb)(unsigned int)) |
| 92 | { |
| 93 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 94 | int ret = 0; |
| 95 | |
| 96 | if (cb) { |
| 97 | trace_cpuhp_enter(cpu, st->target, step, cb); |
| 98 | ret = cb(cpu); |
| 99 | trace_cpuhp_exit(cpu, st->state, step, ret); |
| 100 | } |
| 101 | return ret; |
| 102 | } |
| 103 | |
Rusty Russell | 98a79d6 | 2008-12-13 21:19:41 +1030 | [diff] [blame] | 104 | #ifdef CONFIG_SMP |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 105 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 106 | static DEFINE_MUTEX(cpu_add_remove_lock); |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 107 | bool cpuhp_tasks_frozen; |
| 108 | EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 110 | /* |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 111 | * The following two APIs (cpu_maps_update_begin/done) must be used when |
| 112 | * attempting to serialize the updates to cpu_online_mask & cpu_present_mask. |
| 113 | * The APIs cpu_notifier_register_begin/done() must be used to protect CPU |
| 114 | * hotplug callback (un)registration performed using __register_cpu_notifier() |
| 115 | * or __unregister_cpu_notifier(). |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 116 | */ |
| 117 | void cpu_maps_update_begin(void) |
| 118 | { |
| 119 | mutex_lock(&cpu_add_remove_lock); |
| 120 | } |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 121 | EXPORT_SYMBOL(cpu_notifier_register_begin); |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 122 | |
| 123 | void cpu_maps_update_done(void) |
| 124 | { |
| 125 | mutex_unlock(&cpu_add_remove_lock); |
| 126 | } |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 127 | EXPORT_SYMBOL(cpu_notifier_register_done); |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 128 | |
Daniel J Blueman | 5c113fb | 2010-06-01 12:15:11 +0100 | [diff] [blame] | 129 | static RAW_NOTIFIER_HEAD(cpu_chain); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 131 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
| 132 | * Should always be manipulated under cpu_add_remove_lock |
| 133 | */ |
| 134 | static int cpu_hotplug_disabled; |
| 135 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 136 | #ifdef CONFIG_HOTPLUG_CPU |
| 137 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 138 | static struct { |
| 139 | struct task_struct *active_writer; |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 140 | /* wait queue to wake up the active_writer */ |
| 141 | wait_queue_head_t wq; |
| 142 | /* verifies that no writer will get active while readers are active */ |
| 143 | struct mutex lock; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 144 | /* |
| 145 | * Also blocks the new readers during |
| 146 | * an ongoing cpu hotplug operation. |
| 147 | */ |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 148 | atomic_t refcount; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 149 | |
| 150 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| 151 | struct lockdep_map dep_map; |
| 152 | #endif |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 153 | } cpu_hotplug = { |
| 154 | .active_writer = NULL, |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 155 | .wq = __WAIT_QUEUE_HEAD_INITIALIZER(cpu_hotplug.wq), |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 156 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 157 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| 158 | .dep_map = {.name = "cpu_hotplug.lock" }, |
| 159 | #endif |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 160 | }; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 161 | |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 162 | /* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */ |
| 163 | #define cpuhp_lock_acquire_read() lock_map_acquire_read(&cpu_hotplug.dep_map) |
Paul E. McKenney | dd56af4 | 2014-08-25 20:25:06 -0700 | [diff] [blame] | 164 | #define cpuhp_lock_acquire_tryread() \ |
| 165 | lock_map_acquire_tryread(&cpu_hotplug.dep_map) |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 166 | #define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map) |
| 167 | #define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map) |
| 168 | |
Paul E. McKenney | 62db99f | 2014-10-22 14:51:49 -0700 | [diff] [blame] | 169 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 170 | void get_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 171 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 172 | might_sleep(); |
| 173 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 174 | return; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 175 | cpuhp_lock_acquire_read(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 176 | mutex_lock(&cpu_hotplug.lock); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 177 | atomic_inc(&cpu_hotplug.refcount); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 178 | mutex_unlock(&cpu_hotplug.lock); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 179 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 180 | EXPORT_SYMBOL_GPL(get_online_cpus); |
Ashok Raj | 90d45d1 | 2005-11-08 21:34:24 -0800 | [diff] [blame] | 181 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 182 | void put_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 183 | { |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 184 | int refcount; |
| 185 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 186 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 187 | return; |
Srivatsa S. Bhat | 075663d | 2012-10-08 16:28:20 -0700 | [diff] [blame] | 188 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 189 | refcount = atomic_dec_return(&cpu_hotplug.refcount); |
| 190 | if (WARN_ON(refcount < 0)) /* try to fix things up */ |
| 191 | atomic_inc(&cpu_hotplug.refcount); |
Srivatsa S. Bhat | 075663d | 2012-10-08 16:28:20 -0700 | [diff] [blame] | 192 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 193 | if (refcount <= 0 && waitqueue_active(&cpu_hotplug.wq)) |
| 194 | wake_up(&cpu_hotplug.wq); |
| 195 | |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 196 | cpuhp_lock_release(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 197 | |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 198 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 199 | EXPORT_SYMBOL_GPL(put_online_cpus); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 200 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 201 | /* |
| 202 | * This ensures that the hotplug operation can begin only when the |
| 203 | * refcount goes to zero. |
| 204 | * |
| 205 | * Note that during a cpu-hotplug operation, the new readers, if any, |
| 206 | * will be blocked by the cpu_hotplug.lock |
| 207 | * |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 208 | * Since cpu_hotplug_begin() is always called after invoking |
| 209 | * cpu_maps_update_begin(), we can be sure that only one writer is active. |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 210 | * |
| 211 | * Note that theoretically, there is a possibility of a livelock: |
| 212 | * - Refcount goes to zero, last reader wakes up the sleeping |
| 213 | * writer. |
| 214 | * - Last reader unlocks the cpu_hotplug.lock. |
| 215 | * - A new reader arrives at this moment, bumps up the refcount. |
| 216 | * - The writer acquires the cpu_hotplug.lock finds the refcount |
| 217 | * non zero and goes to sleep again. |
| 218 | * |
| 219 | * However, this is very difficult to achieve in practice since |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 220 | * get_online_cpus() not an api which is called all that often. |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 221 | * |
| 222 | */ |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 223 | void cpu_hotplug_begin(void) |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 224 | { |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 225 | DEFINE_WAIT(wait); |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 226 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 227 | cpu_hotplug.active_writer = current; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 228 | cpuhp_lock_acquire(); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 229 | |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 230 | for (;;) { |
| 231 | mutex_lock(&cpu_hotplug.lock); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 232 | prepare_to_wait(&cpu_hotplug.wq, &wait, TASK_UNINTERRUPTIBLE); |
| 233 | if (likely(!atomic_read(&cpu_hotplug.refcount))) |
| 234 | break; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 235 | mutex_unlock(&cpu_hotplug.lock); |
| 236 | schedule(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 237 | } |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 238 | finish_wait(&cpu_hotplug.wq, &wait); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 239 | } |
| 240 | |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 241 | void cpu_hotplug_done(void) |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 242 | { |
| 243 | cpu_hotplug.active_writer = NULL; |
| 244 | mutex_unlock(&cpu_hotplug.lock); |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 245 | cpuhp_lock_release(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 246 | } |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 247 | |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 248 | /* |
| 249 | * Wait for currently running CPU hotplug operations to complete (if any) and |
| 250 | * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects |
| 251 | * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the |
| 252 | * hotplug path before performing hotplug operations. So acquiring that lock |
| 253 | * guarantees mutual exclusion from any currently running hotplug operations. |
| 254 | */ |
| 255 | void cpu_hotplug_disable(void) |
| 256 | { |
| 257 | cpu_maps_update_begin(); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 258 | cpu_hotplug_disabled++; |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 259 | cpu_maps_update_done(); |
| 260 | } |
Vitaly Kuznetsov | 32145c4 | 2015-08-05 00:52:47 -0700 | [diff] [blame] | 261 | EXPORT_SYMBOL_GPL(cpu_hotplug_disable); |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 262 | |
| 263 | void cpu_hotplug_enable(void) |
| 264 | { |
| 265 | cpu_maps_update_begin(); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 266 | WARN_ON(--cpu_hotplug_disabled < 0); |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 267 | cpu_maps_update_done(); |
| 268 | } |
Vitaly Kuznetsov | 32145c4 | 2015-08-05 00:52:47 -0700 | [diff] [blame] | 269 | EXPORT_SYMBOL_GPL(cpu_hotplug_enable); |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 270 | #endif /* CONFIG_HOTPLUG_CPU */ |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 271 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | /* Need to know about CPUs going up/down? */ |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 273 | int register_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | { |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 275 | int ret; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 276 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 277 | ret = raw_notifier_chain_register(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 278 | cpu_maps_update_done(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 279 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | } |
Chandra Seetharaman | 65edc68 | 2006-06-27 02:54:08 -0700 | [diff] [blame] | 281 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 282 | int __register_cpu_notifier(struct notifier_block *nb) |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 283 | { |
| 284 | return raw_notifier_chain_register(&cpu_chain, nb); |
| 285 | } |
| 286 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 287 | static int __cpu_notify(unsigned long val, unsigned int cpu, int nr_to_call, |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 288 | int *nr_calls) |
| 289 | { |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 290 | unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0; |
| 291 | void *hcpu = (void *)(long)cpu; |
| 292 | |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 293 | int ret; |
| 294 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 295 | ret = __raw_notifier_call_chain(&cpu_chain, val | mod, hcpu, nr_to_call, |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 296 | nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 297 | |
| 298 | return notifier_to_errno(ret); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 299 | } |
| 300 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 301 | static int cpu_notify(unsigned long val, unsigned int cpu) |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 302 | { |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 303 | return __cpu_notify(val, cpu, -1, NULL); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 304 | } |
| 305 | |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 306 | static void cpu_notify_nofail(unsigned long val, unsigned int cpu) |
| 307 | { |
| 308 | BUG_ON(cpu_notify(val, cpu)); |
| 309 | } |
| 310 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 311 | /* Notifier wrappers for transitioning to state machine */ |
| 312 | static int notify_prepare(unsigned int cpu) |
| 313 | { |
| 314 | int nr_calls = 0; |
| 315 | int ret; |
| 316 | |
| 317 | ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls); |
| 318 | if (ret) { |
| 319 | nr_calls--; |
| 320 | printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", |
| 321 | __func__, cpu); |
| 322 | __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL); |
| 323 | } |
| 324 | return ret; |
| 325 | } |
| 326 | |
| 327 | static int notify_online(unsigned int cpu) |
| 328 | { |
| 329 | cpu_notify(CPU_ONLINE, cpu); |
| 330 | return 0; |
| 331 | } |
| 332 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 333 | static int notify_starting(unsigned int cpu) |
| 334 | { |
| 335 | cpu_notify(CPU_STARTING, cpu); |
| 336 | return 0; |
| 337 | } |
| 338 | |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 339 | static int bringup_wait_for_ap(unsigned int cpu) |
| 340 | { |
| 341 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 342 | |
| 343 | wait_for_completion(&st->done); |
| 344 | return st->result; |
| 345 | } |
| 346 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 347 | static int bringup_cpu(unsigned int cpu) |
| 348 | { |
| 349 | struct task_struct *idle = idle_thread_get(cpu); |
| 350 | int ret; |
| 351 | |
Boris Ostrovsky | aa87717 | 2016-08-03 13:22:28 -0400 | [diff] [blame^] | 352 | /* |
| 353 | * Some architectures have to walk the irq descriptors to |
| 354 | * setup the vector space for the cpu which comes online. |
| 355 | * Prevent irq alloc/free across the bringup. |
| 356 | */ |
| 357 | irq_lock_sparse(); |
| 358 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 359 | /* Arch-specific enabling code. */ |
| 360 | ret = __cpu_up(cpu, idle); |
Boris Ostrovsky | aa87717 | 2016-08-03 13:22:28 -0400 | [diff] [blame^] | 361 | irq_unlock_sparse(); |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 362 | if (ret) { |
| 363 | cpu_notify(CPU_UP_CANCELED, cpu); |
| 364 | return ret; |
| 365 | } |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 366 | ret = bringup_wait_for_ap(cpu); |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 367 | BUG_ON(!cpu_online(cpu)); |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 368 | return ret; |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 369 | } |
| 370 | |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 371 | /* |
| 372 | * Hotplug state machine related functions |
| 373 | */ |
| 374 | static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st, |
| 375 | struct cpuhp_step *steps) |
| 376 | { |
| 377 | for (st->state++; st->state < st->target; st->state++) { |
| 378 | struct cpuhp_step *step = steps + st->state; |
| 379 | |
| 380 | if (!step->skip_onerr) |
| 381 | cpuhp_invoke_callback(cpu, st->state, step->startup); |
| 382 | } |
| 383 | } |
| 384 | |
| 385 | static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, |
| 386 | struct cpuhp_step *steps, enum cpuhp_state target) |
| 387 | { |
| 388 | enum cpuhp_state prev_state = st->state; |
| 389 | int ret = 0; |
| 390 | |
| 391 | for (; st->state > target; st->state--) { |
| 392 | struct cpuhp_step *step = steps + st->state; |
| 393 | |
| 394 | ret = cpuhp_invoke_callback(cpu, st->state, step->teardown); |
| 395 | if (ret) { |
| 396 | st->target = prev_state; |
| 397 | undo_cpu_down(cpu, st, steps); |
| 398 | break; |
| 399 | } |
| 400 | } |
| 401 | return ret; |
| 402 | } |
| 403 | |
| 404 | static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st, |
| 405 | struct cpuhp_step *steps) |
| 406 | { |
| 407 | for (st->state--; st->state > st->target; st->state--) { |
| 408 | struct cpuhp_step *step = steps + st->state; |
| 409 | |
| 410 | if (!step->skip_onerr) |
| 411 | cpuhp_invoke_callback(cpu, st->state, step->teardown); |
| 412 | } |
| 413 | } |
| 414 | |
| 415 | static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, |
| 416 | struct cpuhp_step *steps, enum cpuhp_state target) |
| 417 | { |
| 418 | enum cpuhp_state prev_state = st->state; |
| 419 | int ret = 0; |
| 420 | |
| 421 | while (st->state < target) { |
| 422 | struct cpuhp_step *step; |
| 423 | |
| 424 | st->state++; |
| 425 | step = steps + st->state; |
| 426 | ret = cpuhp_invoke_callback(cpu, st->state, step->startup); |
| 427 | if (ret) { |
| 428 | st->target = prev_state; |
| 429 | undo_cpu_up(cpu, st, steps); |
| 430 | break; |
| 431 | } |
| 432 | } |
| 433 | return ret; |
| 434 | } |
| 435 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 436 | /* |
| 437 | * The cpu hotplug threads manage the bringup and teardown of the cpus |
| 438 | */ |
| 439 | static void cpuhp_create(unsigned int cpu) |
| 440 | { |
| 441 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 442 | |
| 443 | init_completion(&st->done); |
| 444 | } |
| 445 | |
| 446 | static int cpuhp_should_run(unsigned int cpu) |
| 447 | { |
| 448 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 449 | |
| 450 | return st->should_run; |
| 451 | } |
| 452 | |
| 453 | /* Execute the teardown callbacks. Used to be CPU_DOWN_PREPARE */ |
| 454 | static int cpuhp_ap_offline(unsigned int cpu, struct cpuhp_cpu_state *st) |
| 455 | { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 456 | enum cpuhp_state target = max((int)st->target, CPUHP_TEARDOWN_CPU); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 457 | |
| 458 | return cpuhp_down_callbacks(cpu, st, cpuhp_ap_states, target); |
| 459 | } |
| 460 | |
| 461 | /* Execute the online startup callbacks. Used to be CPU_ONLINE */ |
| 462 | static int cpuhp_ap_online(unsigned int cpu, struct cpuhp_cpu_state *st) |
| 463 | { |
| 464 | return cpuhp_up_callbacks(cpu, st, cpuhp_ap_states, st->target); |
| 465 | } |
| 466 | |
| 467 | /* |
| 468 | * Execute teardown/startup callbacks on the plugged cpu. Also used to invoke |
| 469 | * callbacks when a state gets [un]installed at runtime. |
| 470 | */ |
| 471 | static void cpuhp_thread_fun(unsigned int cpu) |
| 472 | { |
| 473 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 474 | int ret = 0; |
| 475 | |
| 476 | /* |
| 477 | * Paired with the mb() in cpuhp_kick_ap_work and |
| 478 | * cpuhp_invoke_ap_callback, so the work set is consistent visible. |
| 479 | */ |
| 480 | smp_mb(); |
| 481 | if (!st->should_run) |
| 482 | return; |
| 483 | |
| 484 | st->should_run = false; |
| 485 | |
| 486 | /* Single callback invocation for [un]install ? */ |
| 487 | if (st->cb) { |
| 488 | if (st->cb_state < CPUHP_AP_ONLINE) { |
| 489 | local_irq_disable(); |
| 490 | ret = cpuhp_invoke_callback(cpu, st->cb_state, st->cb); |
| 491 | local_irq_enable(); |
| 492 | } else { |
| 493 | ret = cpuhp_invoke_callback(cpu, st->cb_state, st->cb); |
| 494 | } |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 495 | } else if (st->rollback) { |
| 496 | BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE); |
| 497 | |
| 498 | undo_cpu_down(cpu, st, cpuhp_ap_states); |
| 499 | /* |
| 500 | * This is a momentary workaround to keep the notifier users |
| 501 | * happy. Will go away once we got rid of the notifiers. |
| 502 | */ |
| 503 | cpu_notify_nofail(CPU_DOWN_FAILED, cpu); |
| 504 | st->rollback = false; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 505 | } else { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 506 | /* Cannot happen .... */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 507 | BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 508 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 509 | /* Regular hotplug work */ |
| 510 | if (st->state < st->target) |
| 511 | ret = cpuhp_ap_online(cpu, st); |
| 512 | else if (st->state > st->target) |
| 513 | ret = cpuhp_ap_offline(cpu, st); |
| 514 | } |
| 515 | st->result = ret; |
| 516 | complete(&st->done); |
| 517 | } |
| 518 | |
| 519 | /* Invoke a single callback on a remote cpu */ |
| 520 | static int cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state, |
| 521 | int (*cb)(unsigned int)) |
| 522 | { |
| 523 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 524 | |
| 525 | if (!cpu_online(cpu)) |
| 526 | return 0; |
| 527 | |
Thomas Gleixner | 6a4e245 | 2016-07-13 17:16:03 +0000 | [diff] [blame] | 528 | /* |
| 529 | * If we are up and running, use the hotplug thread. For early calls |
| 530 | * we invoke the thread function directly. |
| 531 | */ |
| 532 | if (!st->thread) |
| 533 | return cpuhp_invoke_callback(cpu, state, cb); |
| 534 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 535 | st->cb_state = state; |
| 536 | st->cb = cb; |
| 537 | /* |
| 538 | * Make sure the above stores are visible before should_run becomes |
| 539 | * true. Paired with the mb() above in cpuhp_thread_fun() |
| 540 | */ |
| 541 | smp_mb(); |
| 542 | st->should_run = true; |
| 543 | wake_up_process(st->thread); |
| 544 | wait_for_completion(&st->done); |
| 545 | return st->result; |
| 546 | } |
| 547 | |
| 548 | /* Regular hotplug invocation of the AP hotplug thread */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 549 | static void __cpuhp_kick_ap_work(struct cpuhp_cpu_state *st) |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 550 | { |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 551 | st->result = 0; |
| 552 | st->cb = NULL; |
| 553 | /* |
| 554 | * Make sure the above stores are visible before should_run becomes |
| 555 | * true. Paired with the mb() above in cpuhp_thread_fun() |
| 556 | */ |
| 557 | smp_mb(); |
| 558 | st->should_run = true; |
| 559 | wake_up_process(st->thread); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 560 | } |
| 561 | |
| 562 | static int cpuhp_kick_ap_work(unsigned int cpu) |
| 563 | { |
| 564 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 565 | enum cpuhp_state state = st->state; |
| 566 | |
| 567 | trace_cpuhp_enter(cpu, st->target, state, cpuhp_kick_ap_work); |
| 568 | __cpuhp_kick_ap_work(st); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 569 | wait_for_completion(&st->done); |
| 570 | trace_cpuhp_exit(cpu, st->state, state, st->result); |
| 571 | return st->result; |
| 572 | } |
| 573 | |
| 574 | static struct smp_hotplug_thread cpuhp_threads = { |
| 575 | .store = &cpuhp_state.thread, |
| 576 | .create = &cpuhp_create, |
| 577 | .thread_should_run = cpuhp_should_run, |
| 578 | .thread_fn = cpuhp_thread_fun, |
| 579 | .thread_comm = "cpuhp/%u", |
| 580 | .selfparking = true, |
| 581 | }; |
| 582 | |
| 583 | void __init cpuhp_threads_init(void) |
| 584 | { |
| 585 | BUG_ON(smpboot_register_percpu_thread(&cpuhp_threads)); |
| 586 | kthread_unpark(this_cpu_read(cpuhp_state.thread)); |
| 587 | } |
| 588 | |
Linus Torvalds | 00b9b0a | 2010-05-27 10:32:08 -0700 | [diff] [blame] | 589 | #ifdef CONFIG_HOTPLUG_CPU |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 590 | EXPORT_SYMBOL(register_cpu_notifier); |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 591 | EXPORT_SYMBOL(__register_cpu_notifier); |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 592 | void unregister_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 594 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 595 | raw_notifier_chain_unregister(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 596 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 597 | } |
| 598 | EXPORT_SYMBOL(unregister_cpu_notifier); |
| 599 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 600 | void __unregister_cpu_notifier(struct notifier_block *nb) |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 601 | { |
| 602 | raw_notifier_chain_unregister(&cpu_chain, nb); |
| 603 | } |
| 604 | EXPORT_SYMBOL(__unregister_cpu_notifier); |
| 605 | |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 606 | /** |
| 607 | * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU |
| 608 | * @cpu: a CPU id |
| 609 | * |
| 610 | * This function walks all processes, finds a valid mm struct for each one and |
| 611 | * then clears a corresponding bit in mm's cpumask. While this all sounds |
| 612 | * trivial, there are various non-obvious corner cases, which this function |
| 613 | * tries to solve in a safe manner. |
| 614 | * |
| 615 | * Also note that the function uses a somewhat relaxed locking scheme, so it may |
| 616 | * be called only for an already offlined CPU. |
| 617 | */ |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 618 | void clear_tasks_mm_cpumask(int cpu) |
| 619 | { |
| 620 | struct task_struct *p; |
| 621 | |
| 622 | /* |
| 623 | * This function is called after the cpu is taken down and marked |
| 624 | * offline, so its not like new tasks will ever get this cpu set in |
| 625 | * their mm mask. -- Peter Zijlstra |
| 626 | * Thus, we may use rcu_read_lock() here, instead of grabbing |
| 627 | * full-fledged tasklist_lock. |
| 628 | */ |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 629 | WARN_ON(cpu_online(cpu)); |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 630 | rcu_read_lock(); |
| 631 | for_each_process(p) { |
| 632 | struct task_struct *t; |
| 633 | |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 634 | /* |
| 635 | * Main thread might exit, but other threads may still have |
| 636 | * a valid mm. Find one. |
| 637 | */ |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 638 | t = find_lock_task_mm(p); |
| 639 | if (!t) |
| 640 | continue; |
| 641 | cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); |
| 642 | task_unlock(t); |
| 643 | } |
| 644 | rcu_read_unlock(); |
| 645 | } |
| 646 | |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 647 | static inline void check_for_tasks(int dead_cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 648 | { |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 649 | struct task_struct *g, *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | |
Oleg Nesterov | a75a606 | 2015-09-10 15:07:50 +0200 | [diff] [blame] | 651 | read_lock(&tasklist_lock); |
| 652 | for_each_process_thread(g, p) { |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 653 | if (!p->on_rq) |
| 654 | continue; |
| 655 | /* |
| 656 | * We do the check with unlocked task_rq(p)->lock. |
| 657 | * Order the reading to do not warn about a task, |
| 658 | * which was running on this cpu in the past, and |
| 659 | * it's just been woken on another cpu. |
| 660 | */ |
| 661 | rmb(); |
| 662 | if (task_cpu(p) != dead_cpu) |
| 663 | continue; |
| 664 | |
| 665 | pr_warn("Task %s (pid=%d) is on cpu %d (state=%ld, flags=%x)\n", |
| 666 | p->comm, task_pid_nr(p), dead_cpu, p->state, p->flags); |
Oleg Nesterov | a75a606 | 2015-09-10 15:07:50 +0200 | [diff] [blame] | 667 | } |
| 668 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | } |
| 670 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 671 | static int notify_down_prepare(unsigned int cpu) |
| 672 | { |
| 673 | int err, nr_calls = 0; |
| 674 | |
| 675 | err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls); |
| 676 | if (err) { |
| 677 | nr_calls--; |
| 678 | __cpu_notify(CPU_DOWN_FAILED, cpu, nr_calls, NULL); |
| 679 | pr_warn("%s: attempt to take down CPU %u failed\n", |
| 680 | __func__, cpu); |
| 681 | } |
| 682 | return err; |
| 683 | } |
| 684 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 685 | static int notify_dying(unsigned int cpu) |
| 686 | { |
| 687 | cpu_notify(CPU_DYING, cpu); |
| 688 | return 0; |
| 689 | } |
| 690 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | /* Take this CPU down. */ |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 692 | static int take_cpu_down(void *_param) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 693 | { |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 694 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 695 | enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE); |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 696 | int err, cpu = smp_processor_id(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 697 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | /* Ensure this CPU doesn't handle any more interrupts. */ |
| 699 | err = __cpu_disable(); |
| 700 | if (err < 0) |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 701 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 702 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 703 | /* Invoke the former CPU_DYING callbacks */ |
| 704 | for (; st->state > target; st->state--) { |
| 705 | struct cpuhp_step *step = cpuhp_ap_states + st->state; |
| 706 | |
| 707 | cpuhp_invoke_callback(cpu, st->state, step->teardown); |
| 708 | } |
Thomas Gleixner | 52c063d | 2015-04-03 02:37:24 +0200 | [diff] [blame] | 709 | /* Give up timekeeping duties */ |
| 710 | tick_handover_do_timer(); |
Thomas Gleixner | 14e568e | 2013-01-31 12:11:14 +0000 | [diff] [blame] | 711 | /* Park the stopper thread */ |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 712 | stop_machine_park(cpu); |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 713 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 714 | } |
| 715 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 716 | static int takedown_cpu(unsigned int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | { |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 718 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 719 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | |
Thomas Gleixner | 2a58c52 | 2016-03-10 20:42:08 +0100 | [diff] [blame] | 721 | /* Park the smpboot threads */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 722 | kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread); |
Thomas Gleixner | 2a58c52 | 2016-03-10 20:42:08 +0100 | [diff] [blame] | 723 | smpboot_park_threads(cpu); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 724 | |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 725 | /* |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 726 | * Prevent irq alloc/free while the dying cpu reorganizes the |
| 727 | * interrupt affinities. |
| 728 | */ |
| 729 | irq_lock_sparse(); |
| 730 | |
| 731 | /* |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 732 | * So now all preempt/rcu users must observe !cpu_active(). |
| 733 | */ |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 734 | err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu)); |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 735 | if (err) { |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 736 | /* CPU refused to die */ |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 737 | irq_unlock_sparse(); |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 738 | /* Unpark the hotplug thread so we can rollback there */ |
| 739 | kthread_unpark(per_cpu_ptr(&cpuhp_state, cpu)->thread); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 740 | return err; |
Satoru Takeuchi | 8fa1d7d | 2006-10-28 10:38:57 -0700 | [diff] [blame] | 741 | } |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 742 | BUG_ON(cpu_online(cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 744 | /* |
| 745 | * The migration_call() CPU_DYING callback will have removed all |
| 746 | * runnable tasks from the cpu, there's only the idle task left now |
| 747 | * that the migration thread is done doing the stop_machine thing. |
Peter Zijlstra | 51a96c7 | 2010-11-19 20:37:53 +0100 | [diff] [blame] | 748 | * |
| 749 | * Wait for the stop thread to go away. |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 750 | */ |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 751 | wait_for_completion(&st->done); |
| 752 | BUG_ON(st->state != CPUHP_AP_IDLE_DEAD); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 754 | /* Interrupts are moved away from the dying cpu, reenable alloc/free */ |
| 755 | irq_unlock_sparse(); |
| 756 | |
Preeti U Murthy | 345527b | 2015-03-30 14:59:19 +0530 | [diff] [blame] | 757 | hotplug_cpu__broadcast_tick_pull(cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 758 | /* This actually kills the CPU. */ |
| 759 | __cpu_die(cpu); |
| 760 | |
Thomas Gleixner | a49b116 | 2015-04-03 02:38:05 +0200 | [diff] [blame] | 761 | tick_cleanup_dead_cpu(cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 762 | return 0; |
| 763 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 765 | static int notify_dead(unsigned int cpu) |
| 766 | { |
| 767 | cpu_notify_nofail(CPU_DEAD, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | check_for_tasks(cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 769 | return 0; |
| 770 | } |
| 771 | |
Thomas Gleixner | 71f87b2 | 2016-03-03 10:52:10 +0100 | [diff] [blame] | 772 | static void cpuhp_complete_idle_dead(void *arg) |
| 773 | { |
| 774 | struct cpuhp_cpu_state *st = arg; |
| 775 | |
| 776 | complete(&st->done); |
| 777 | } |
| 778 | |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 779 | void cpuhp_report_idle_dead(void) |
| 780 | { |
| 781 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 782 | |
| 783 | BUG_ON(st->state != CPUHP_AP_OFFLINE); |
Thomas Gleixner | 27d50c7 | 2016-02-26 18:43:44 +0000 | [diff] [blame] | 784 | rcu_report_dead(smp_processor_id()); |
Thomas Gleixner | 71f87b2 | 2016-03-03 10:52:10 +0100 | [diff] [blame] | 785 | st->state = CPUHP_AP_IDLE_DEAD; |
| 786 | /* |
| 787 | * We cannot call complete after rcu_report_dead() so we delegate it |
| 788 | * to an online cpu. |
| 789 | */ |
| 790 | smp_call_function_single(cpumask_first(cpu_online_mask), |
| 791 | cpuhp_complete_idle_dead, st, 0); |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 792 | } |
| 793 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 794 | #else |
| 795 | #define notify_down_prepare NULL |
| 796 | #define takedown_cpu NULL |
| 797 | #define notify_dead NULL |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 798 | #define notify_dying NULL |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 799 | #endif |
| 800 | |
| 801 | #ifdef CONFIG_HOTPLUG_CPU |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 802 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 803 | /* Requires cpu_add_remove_lock to be held */ |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 804 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, |
| 805 | enum cpuhp_state target) |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 806 | { |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 807 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 808 | int prev_state, ret = 0; |
| 809 | bool hasdied = false; |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 810 | |
| 811 | if (num_online_cpus() == 1) |
| 812 | return -EBUSY; |
| 813 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 814 | if (!cpu_present(cpu)) |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 815 | return -EINVAL; |
| 816 | |
| 817 | cpu_hotplug_begin(); |
| 818 | |
| 819 | cpuhp_tasks_frozen = tasks_frozen; |
| 820 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 821 | prev_state = st->state; |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 822 | st->target = target; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 823 | /* |
| 824 | * If the current CPU state is in the range of the AP hotplug thread, |
| 825 | * then we need to kick the thread. |
| 826 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 827 | if (st->state > CPUHP_TEARDOWN_CPU) { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 828 | ret = cpuhp_kick_ap_work(cpu); |
| 829 | /* |
| 830 | * The AP side has done the error rollback already. Just |
| 831 | * return the error code.. |
| 832 | */ |
| 833 | if (ret) |
| 834 | goto out; |
| 835 | |
| 836 | /* |
| 837 | * We might have stopped still in the range of the AP hotplug |
| 838 | * thread. Nothing to do anymore. |
| 839 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 840 | if (st->state > CPUHP_TEARDOWN_CPU) |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 841 | goto out; |
| 842 | } |
| 843 | /* |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 844 | * The AP brought itself down to CPUHP_TEARDOWN_CPU. So we need |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 845 | * to do the further cleanups. |
| 846 | */ |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 847 | ret = cpuhp_down_callbacks(cpu, st, cpuhp_bp_states, target); |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 848 | if (ret && st->state > CPUHP_TEARDOWN_CPU && st->state < prev_state) { |
| 849 | st->target = prev_state; |
| 850 | st->rollback = true; |
| 851 | cpuhp_kick_ap_work(cpu); |
| 852 | } |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 853 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 854 | hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 855 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 856 | cpu_hotplug_done(); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 857 | /* This post dead nonsense must die */ |
| 858 | if (!ret && hasdied) |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 859 | cpu_notify_nofail(CPU_POST_DEAD, cpu); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 860 | return ret; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 861 | } |
| 862 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 863 | static int do_cpu_down(unsigned int cpu, enum cpuhp_state target) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 864 | { |
Heiko Carstens | 9ea09af | 2008-12-22 12:36:30 +0100 | [diff] [blame] | 865 | int err; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 866 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 867 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 868 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 869 | if (cpu_hotplug_disabled) { |
| 870 | err = -EBUSY; |
| 871 | goto out; |
| 872 | } |
| 873 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 874 | err = _cpu_down(cpu, 0, target); |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 875 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 876 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 877 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 878 | return err; |
| 879 | } |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 880 | int cpu_down(unsigned int cpu) |
| 881 | { |
| 882 | return do_cpu_down(cpu, CPUHP_OFFLINE); |
| 883 | } |
Zhang Rui | b62b8ef | 2008-04-29 02:35:56 -0400 | [diff] [blame] | 884 | EXPORT_SYMBOL(cpu_down); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 885 | #endif /*CONFIG_HOTPLUG_CPU*/ |
| 886 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 887 | /** |
| 888 | * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers |
| 889 | * @cpu: cpu that just started |
| 890 | * |
| 891 | * This function calls the cpu_chain notifiers with CPU_STARTING. |
| 892 | * It must be called by the arch code on the new cpu, before the new cpu |
| 893 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). |
| 894 | */ |
| 895 | void notify_cpu_starting(unsigned int cpu) |
| 896 | { |
| 897 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 898 | enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE); |
| 899 | |
| 900 | while (st->state < target) { |
| 901 | struct cpuhp_step *step; |
| 902 | |
| 903 | st->state++; |
| 904 | step = cpuhp_ap_states + st->state; |
| 905 | cpuhp_invoke_callback(cpu, st->state, step->startup); |
| 906 | } |
| 907 | } |
| 908 | |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 909 | /* |
| 910 | * Called from the idle task. We need to set active here, so we can kick off |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 911 | * the stopper thread and unpark the smpboot threads. If the target state is |
| 912 | * beyond CPUHP_AP_ONLINE_IDLE we kick cpuhp thread and let it bring up the |
| 913 | * cpu further. |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 914 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 915 | void cpuhp_online_idle(enum cpuhp_state state) |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 916 | { |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 917 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 918 | unsigned int cpu = smp_processor_id(); |
| 919 | |
| 920 | /* Happens for the boot cpu */ |
| 921 | if (state != CPUHP_AP_ONLINE_IDLE) |
| 922 | return; |
| 923 | |
| 924 | st->state = CPUHP_AP_ONLINE_IDLE; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 925 | |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 926 | /* Unpark the stopper thread and the hotplug thread of this cpu */ |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 927 | stop_machine_unpark(cpu); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 928 | kthread_unpark(st->thread); |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 929 | |
| 930 | /* Should we go further up ? */ |
| 931 | if (st->target > CPUHP_AP_ONLINE_IDLE) |
| 932 | __cpuhp_kick_ap_work(st); |
| 933 | else |
| 934 | complete(&st->done); |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 935 | } |
| 936 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 937 | /* Requires cpu_add_remove_lock to be held */ |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 938 | static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 939 | { |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 940 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 941 | struct task_struct *idle; |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 942 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 943 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 944 | cpu_hotplug_begin(); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 945 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 946 | if (!cpu_present(cpu)) { |
Yasuaki Ishimatsu | 5e5041f | 2012-10-23 01:30:54 +0200 | [diff] [blame] | 947 | ret = -EINVAL; |
| 948 | goto out; |
| 949 | } |
| 950 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 951 | /* |
| 952 | * The caller of do_cpu_up might have raced with another |
| 953 | * caller. Ignore it for now. |
| 954 | */ |
| 955 | if (st->state >= target) |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 956 | goto out; |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 957 | |
| 958 | if (st->state == CPUHP_OFFLINE) { |
| 959 | /* Let it fail before we try to bring the cpu up */ |
| 960 | idle = idle_thread_get(cpu); |
| 961 | if (IS_ERR(idle)) { |
| 962 | ret = PTR_ERR(idle); |
| 963 | goto out; |
| 964 | } |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 965 | } |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 966 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 967 | cpuhp_tasks_frozen = tasks_frozen; |
| 968 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 969 | st->target = target; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 970 | /* |
| 971 | * If the current CPU state is in the range of the AP hotplug thread, |
| 972 | * then we need to kick the thread once more. |
| 973 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 974 | if (st->state > CPUHP_BRINGUP_CPU) { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 975 | ret = cpuhp_kick_ap_work(cpu); |
| 976 | /* |
| 977 | * The AP side has done the error rollback already. Just |
| 978 | * return the error code.. |
| 979 | */ |
| 980 | if (ret) |
| 981 | goto out; |
| 982 | } |
| 983 | |
| 984 | /* |
| 985 | * Try to reach the target state. We max out on the BP at |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 986 | * CPUHP_BRINGUP_CPU. After that the AP hotplug thread is |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 987 | * responsible for bringing it up to the target state. |
| 988 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 989 | target = min((int)target, CPUHP_BRINGUP_CPU); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 990 | ret = cpuhp_up_callbacks(cpu, st, cpuhp_bp_states, target); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 991 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 992 | cpu_hotplug_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 993 | return ret; |
| 994 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 995 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 996 | static int do_cpu_up(unsigned int cpu, enum cpuhp_state target) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 997 | { |
| 998 | int err = 0; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 999 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1000 | if (!cpu_possible(cpu)) { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1001 | pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n", |
| 1002 | cpu); |
Chen Gong | 87d5e02 | 2010-03-05 13:42:38 -0800 | [diff] [blame] | 1003 | #if defined(CONFIG_IA64) |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1004 | pr_err("please check additional_cpus= boot parameter\n"); |
KAMEZAWA Hiroyuki | 73e753a | 2007-10-18 23:40:47 -0700 | [diff] [blame] | 1005 | #endif |
| 1006 | return -EINVAL; |
| 1007 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1008 | |
Toshi Kani | 01b0f19 | 2013-11-12 15:07:25 -0800 | [diff] [blame] | 1009 | err = try_online_node(cpu_to_node(cpu)); |
| 1010 | if (err) |
| 1011 | return err; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 1012 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1013 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1014 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 1015 | if (cpu_hotplug_disabled) { |
| 1016 | err = -EBUSY; |
| 1017 | goto out; |
| 1018 | } |
| 1019 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1020 | err = _cpu_up(cpu, 0, target); |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 1021 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1022 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1023 | return err; |
| 1024 | } |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1025 | |
| 1026 | int cpu_up(unsigned int cpu) |
| 1027 | { |
| 1028 | return do_cpu_up(cpu, CPUHP_ONLINE); |
| 1029 | } |
Paul E. McKenney | a513f6b | 2011-12-11 21:54:45 -0800 | [diff] [blame] | 1030 | EXPORT_SYMBOL_GPL(cpu_up); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1031 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 1032 | #ifdef CONFIG_PM_SLEEP_SMP |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1033 | static cpumask_var_t frozen_cpus; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1034 | |
| 1035 | int disable_nonboot_cpus(void) |
| 1036 | { |
Rafael J. Wysocki | e9a5f42 | 2010-05-27 22:16:22 +0200 | [diff] [blame] | 1037 | int cpu, first_cpu, error = 0; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1038 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1039 | cpu_maps_update_begin(); |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1040 | first_cpu = cpumask_first(cpu_online_mask); |
Xiaotian Feng | 9ee349a | 2009-12-16 18:04:32 +0100 | [diff] [blame] | 1041 | /* |
| 1042 | * We take down all of the non-boot CPUs in one shot to avoid races |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1043 | * with the userspace trying to use the CPU hotplug at the same time |
| 1044 | */ |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1045 | cpumask_clear(frozen_cpus); |
Peter Zijlstra | 6ad4c18 | 2009-11-25 13:31:39 +0100 | [diff] [blame] | 1046 | |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1047 | pr_info("Disabling non-boot CPUs ...\n"); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1048 | for_each_online_cpu(cpu) { |
| 1049 | if (cpu == first_cpu) |
| 1050 | continue; |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1051 | trace_suspend_resume(TPS("CPU_OFF"), cpu, true); |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1052 | error = _cpu_down(cpu, 1, CPUHP_OFFLINE); |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1053 | trace_suspend_resume(TPS("CPU_OFF"), cpu, false); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 1054 | if (!error) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1055 | cpumask_set_cpu(cpu, frozen_cpus); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 1056 | else { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1057 | pr_err("Error taking CPU%d down: %d\n", cpu, error); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1058 | break; |
| 1059 | } |
| 1060 | } |
Joseph Cihula | 86886e5 | 2009-06-30 19:31:07 -0700 | [diff] [blame] | 1061 | |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1062 | if (!error) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1063 | BUG_ON(num_online_cpus() > 1); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1064 | else |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1065 | pr_err("Non-boot CPUs are not disabled\n"); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1066 | |
| 1067 | /* |
| 1068 | * Make sure the CPUs won't be enabled by someone else. We need to do |
| 1069 | * this even in case of failure as all disable_nonboot_cpus() users are |
| 1070 | * supposed to do enable_nonboot_cpus() on the failure path. |
| 1071 | */ |
| 1072 | cpu_hotplug_disabled++; |
| 1073 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1074 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1075 | return error; |
| 1076 | } |
| 1077 | |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1078 | void __weak arch_enable_nonboot_cpus_begin(void) |
| 1079 | { |
| 1080 | } |
| 1081 | |
| 1082 | void __weak arch_enable_nonboot_cpus_end(void) |
| 1083 | { |
| 1084 | } |
| 1085 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 1086 | void enable_nonboot_cpus(void) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1087 | { |
| 1088 | int cpu, error; |
| 1089 | |
| 1090 | /* Allow everyone to use the CPU hotplug again */ |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1091 | cpu_maps_update_begin(); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1092 | WARN_ON(--cpu_hotplug_disabled < 0); |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1093 | if (cpumask_empty(frozen_cpus)) |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 1094 | goto out; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1095 | |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1096 | pr_info("Enabling non-boot CPUs ...\n"); |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1097 | |
| 1098 | arch_enable_nonboot_cpus_begin(); |
| 1099 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1100 | for_each_cpu(cpu, frozen_cpus) { |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1101 | trace_suspend_resume(TPS("CPU_ON"), cpu, true); |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1102 | error = _cpu_up(cpu, 1, CPUHP_ONLINE); |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1103 | trace_suspend_resume(TPS("CPU_ON"), cpu, false); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1104 | if (!error) { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1105 | pr_info("CPU%d is up\n", cpu); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1106 | continue; |
| 1107 | } |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1108 | pr_warn("Error taking CPU%d up: %d\n", cpu, error); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1109 | } |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1110 | |
| 1111 | arch_enable_nonboot_cpus_end(); |
| 1112 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1113 | cpumask_clear(frozen_cpus); |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 1114 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1115 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1116 | } |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1117 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 1118 | static int __init alloc_frozen_cpus(void) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1119 | { |
| 1120 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) |
| 1121 | return -ENOMEM; |
| 1122 | return 0; |
| 1123 | } |
| 1124 | core_initcall(alloc_frozen_cpus); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1125 | |
| 1126 | /* |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1127 | * When callbacks for CPU hotplug notifications are being executed, we must |
| 1128 | * ensure that the state of the system with respect to the tasks being frozen |
| 1129 | * or not, as reported by the notification, remains unchanged *throughout the |
| 1130 | * duration* of the execution of the callbacks. |
| 1131 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. |
| 1132 | * |
| 1133 | * This synchronization is implemented by mutually excluding regular CPU |
| 1134 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ |
| 1135 | * Hibernate notifications. |
| 1136 | */ |
| 1137 | static int |
| 1138 | cpu_hotplug_pm_callback(struct notifier_block *nb, |
| 1139 | unsigned long action, void *ptr) |
| 1140 | { |
| 1141 | switch (action) { |
| 1142 | |
| 1143 | case PM_SUSPEND_PREPARE: |
| 1144 | case PM_HIBERNATION_PREPARE: |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 1145 | cpu_hotplug_disable(); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1146 | break; |
| 1147 | |
| 1148 | case PM_POST_SUSPEND: |
| 1149 | case PM_POST_HIBERNATION: |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 1150 | cpu_hotplug_enable(); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1151 | break; |
| 1152 | |
| 1153 | default: |
| 1154 | return NOTIFY_DONE; |
| 1155 | } |
| 1156 | |
| 1157 | return NOTIFY_OK; |
| 1158 | } |
| 1159 | |
| 1160 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 1161 | static int __init cpu_hotplug_pm_sync_init(void) |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1162 | { |
Fenghua Yu | 6e32d47 | 2012-11-13 11:32:43 -0800 | [diff] [blame] | 1163 | /* |
| 1164 | * cpu_hotplug_pm_callback has higher priority than x86 |
| 1165 | * bsp_pm_callback which depends on cpu_hotplug_pm_callback |
| 1166 | * to disable cpu hotplug to avoid cpu hotplug race. |
| 1167 | */ |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1168 | pm_notifier(cpu_hotplug_pm_callback, 0); |
| 1169 | return 0; |
| 1170 | } |
| 1171 | core_initcall(cpu_hotplug_pm_sync_init); |
| 1172 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 1173 | #endif /* CONFIG_PM_SLEEP_SMP */ |
Max Krasnyansky | 68f4f1e | 2008-05-29 11:17:02 -0700 | [diff] [blame] | 1174 | |
| 1175 | #endif /* CONFIG_SMP */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1176 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1177 | /* Boot processor state steps */ |
| 1178 | static struct cpuhp_step cpuhp_bp_states[] = { |
| 1179 | [CPUHP_OFFLINE] = { |
| 1180 | .name = "offline", |
| 1181 | .startup = NULL, |
| 1182 | .teardown = NULL, |
| 1183 | }, |
| 1184 | #ifdef CONFIG_SMP |
| 1185 | [CPUHP_CREATE_THREADS]= { |
| 1186 | .name = "threads:create", |
| 1187 | .startup = smpboot_create_threads, |
| 1188 | .teardown = NULL, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1189 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1190 | }, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1191 | [CPUHP_PERF_PREPARE] = { |
| 1192 | .name = "perf prepare", |
| 1193 | .startup = perf_event_init_cpu, |
| 1194 | .teardown = perf_event_exit_cpu, |
| 1195 | }, |
Thomas Gleixner | 7ee681b | 2016-07-13 17:16:29 +0000 | [diff] [blame] | 1196 | [CPUHP_WORKQUEUE_PREP] = { |
| 1197 | .name = "workqueue prepare", |
| 1198 | .startup = workqueue_prepare_cpu, |
| 1199 | .teardown = NULL, |
| 1200 | }, |
Thomas Gleixner | 27590dc | 2016-07-15 10:41:04 +0200 | [diff] [blame] | 1201 | [CPUHP_HRTIMERS_PREPARE] = { |
| 1202 | .name = "hrtimers prepare", |
| 1203 | .startup = hrtimers_prepare_cpu, |
| 1204 | .teardown = hrtimers_dead_cpu, |
| 1205 | }, |
Richard Weinberger | 31487f8 | 2016-07-13 17:17:01 +0000 | [diff] [blame] | 1206 | [CPUHP_SMPCFD_PREPARE] = { |
| 1207 | .name = "SMPCFD prepare", |
| 1208 | .startup = smpcfd_prepare_cpu, |
| 1209 | .teardown = smpcfd_dead_cpu, |
| 1210 | }, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1211 | [CPUHP_RCUTREE_PREP] = { |
| 1212 | .name = "RCU-tree prepare", |
| 1213 | .startup = rcutree_prepare_cpu, |
| 1214 | .teardown = rcutree_dead_cpu, |
| 1215 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1216 | /* |
| 1217 | * Preparatory and dead notifiers. Will be replaced once the notifiers |
| 1218 | * are converted to states. |
| 1219 | */ |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1220 | [CPUHP_NOTIFY_PREPARE] = { |
| 1221 | .name = "notify:prepare", |
| 1222 | .startup = notify_prepare, |
| 1223 | .teardown = notify_dead, |
| 1224 | .skip_onerr = true, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1225 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1226 | }, |
Richard Cochran | 4fae16d | 2016-07-27 11:08:18 +0200 | [diff] [blame] | 1227 | /* |
| 1228 | * On the tear-down path, timers_dead_cpu() must be invoked |
| 1229 | * before blk_mq_queue_reinit_notify() from notify_dead(), |
| 1230 | * otherwise a RCU stall occurs. |
| 1231 | */ |
| 1232 | [CPUHP_TIMERS_DEAD] = { |
| 1233 | .name = "timers dead", |
| 1234 | .startup = NULL, |
| 1235 | .teardown = timers_dead_cpu, |
| 1236 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1237 | /* Kicks the plugged cpu into life */ |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1238 | [CPUHP_BRINGUP_CPU] = { |
| 1239 | .name = "cpu:bringup", |
| 1240 | .startup = bringup_cpu, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1241 | .teardown = NULL, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1242 | .cant_stop = true, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1243 | }, |
Richard Weinberger | 31487f8 | 2016-07-13 17:17:01 +0000 | [diff] [blame] | 1244 | [CPUHP_AP_SMPCFD_DYING] = { |
| 1245 | .startup = NULL, |
| 1246 | .teardown = smpcfd_dying_cpu, |
| 1247 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1248 | /* |
| 1249 | * Handled on controll processor until the plugged processor manages |
| 1250 | * this itself. |
| 1251 | */ |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1252 | [CPUHP_TEARDOWN_CPU] = { |
| 1253 | .name = "cpu:teardown", |
| 1254 | .startup = NULL, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1255 | .teardown = takedown_cpu, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1256 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1257 | }, |
Thomas Gleixner | a7c73414 | 2016-07-12 21:59:23 +0200 | [diff] [blame] | 1258 | #else |
| 1259 | [CPUHP_BRINGUP_CPU] = { }, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1260 | #endif |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1261 | }; |
| 1262 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1263 | /* Application processor state steps */ |
| 1264 | static struct cpuhp_step cpuhp_ap_states[] = { |
| 1265 | #ifdef CONFIG_SMP |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1266 | /* Final state before CPU kills itself */ |
| 1267 | [CPUHP_AP_IDLE_DEAD] = { |
| 1268 | .name = "idle:dead", |
| 1269 | }, |
| 1270 | /* |
| 1271 | * Last state before CPU enters the idle loop to die. Transient state |
| 1272 | * for synchronization. |
| 1273 | */ |
| 1274 | [CPUHP_AP_OFFLINE] = { |
| 1275 | .name = "ap:offline", |
| 1276 | .cant_stop = true, |
| 1277 | }, |
Thomas Gleixner | 9cf7243 | 2016-03-10 12:54:09 +0100 | [diff] [blame] | 1278 | /* First state is scheduler control. Interrupts are disabled */ |
| 1279 | [CPUHP_AP_SCHED_STARTING] = { |
| 1280 | .name = "sched:starting", |
| 1281 | .startup = sched_cpu_starting, |
Thomas Gleixner | f2785dd | 2016-03-10 12:54:18 +0100 | [diff] [blame] | 1282 | .teardown = sched_cpu_dying, |
Thomas Gleixner | 9cf7243 | 2016-03-10 12:54:09 +0100 | [diff] [blame] | 1283 | }, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1284 | [CPUHP_AP_RCUTREE_DYING] = { |
| 1285 | .startup = NULL, |
| 1286 | .teardown = rcutree_dying_cpu, |
| 1287 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1288 | /* |
| 1289 | * Low level startup/teardown notifiers. Run with interrupts |
| 1290 | * disabled. Will be removed once the notifiers are converted to |
| 1291 | * states. |
| 1292 | */ |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1293 | [CPUHP_AP_NOTIFY_STARTING] = { |
| 1294 | .name = "notify:starting", |
| 1295 | .startup = notify_starting, |
| 1296 | .teardown = notify_dying, |
| 1297 | .skip_onerr = true, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1298 | .cant_stop = true, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1299 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1300 | /* Entry state on starting. Interrupts enabled from here on. Transient |
| 1301 | * state for synchronsization */ |
| 1302 | [CPUHP_AP_ONLINE] = { |
| 1303 | .name = "ap:online", |
| 1304 | }, |
| 1305 | /* Handle smpboot threads park/unpark */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1306 | [CPUHP_AP_SMPBOOT_THREADS] = { |
| 1307 | .name = "smpboot:threads", |
| 1308 | .startup = smpboot_unpark_threads, |
Thomas Gleixner | 2a58c52 | 2016-03-10 20:42:08 +0100 | [diff] [blame] | 1309 | .teardown = NULL, |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1310 | }, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1311 | [CPUHP_AP_PERF_ONLINE] = { |
| 1312 | .name = "perf online", |
| 1313 | .startup = perf_event_init_cpu, |
| 1314 | .teardown = perf_event_exit_cpu, |
| 1315 | }, |
Thomas Gleixner | 7ee681b | 2016-07-13 17:16:29 +0000 | [diff] [blame] | 1316 | [CPUHP_AP_WORKQUEUE_ONLINE] = { |
| 1317 | .name = "workqueue online", |
| 1318 | .startup = workqueue_online_cpu, |
| 1319 | .teardown = workqueue_offline_cpu, |
| 1320 | }, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1321 | [CPUHP_AP_RCUTREE_ONLINE] = { |
| 1322 | .name = "RCU-tree online", |
| 1323 | .startup = rcutree_online_cpu, |
| 1324 | .teardown = rcutree_offline_cpu, |
| 1325 | }, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1326 | |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1327 | /* |
| 1328 | * Online/down_prepare notifiers. Will be removed once the notifiers |
| 1329 | * are converted to states. |
| 1330 | */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1331 | [CPUHP_AP_NOTIFY_ONLINE] = { |
| 1332 | .name = "notify:online", |
| 1333 | .startup = notify_online, |
| 1334 | .teardown = notify_down_prepare, |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 1335 | .skip_onerr = true, |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1336 | }, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1337 | #endif |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1338 | /* |
| 1339 | * The dynamically registered state space is here |
| 1340 | */ |
| 1341 | |
Thomas Gleixner | aaddd7d | 2016-03-10 12:54:19 +0100 | [diff] [blame] | 1342 | #ifdef CONFIG_SMP |
| 1343 | /* Last state is scheduler control setting the cpu active */ |
| 1344 | [CPUHP_AP_ACTIVE] = { |
| 1345 | .name = "sched:active", |
| 1346 | .startup = sched_cpu_activate, |
| 1347 | .teardown = sched_cpu_deactivate, |
| 1348 | }, |
| 1349 | #endif |
| 1350 | |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1351 | /* CPU is fully up and running. */ |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1352 | [CPUHP_ONLINE] = { |
| 1353 | .name = "online", |
| 1354 | .startup = NULL, |
| 1355 | .teardown = NULL, |
| 1356 | }, |
| 1357 | }; |
| 1358 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1359 | /* Sanity check for callbacks */ |
| 1360 | static int cpuhp_cb_check(enum cpuhp_state state) |
| 1361 | { |
| 1362 | if (state <= CPUHP_OFFLINE || state >= CPUHP_ONLINE) |
| 1363 | return -EINVAL; |
| 1364 | return 0; |
| 1365 | } |
| 1366 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1367 | static bool cpuhp_is_ap_state(enum cpuhp_state state) |
| 1368 | { |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1369 | /* |
| 1370 | * The extra check for CPUHP_TEARDOWN_CPU is only for documentation |
| 1371 | * purposes as that state is handled explicitely in cpu_down. |
| 1372 | */ |
| 1373 | return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU; |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1374 | } |
| 1375 | |
| 1376 | static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state) |
| 1377 | { |
| 1378 | struct cpuhp_step *sp; |
| 1379 | |
| 1380 | sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states; |
| 1381 | return sp + state; |
| 1382 | } |
| 1383 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1384 | static void cpuhp_store_callbacks(enum cpuhp_state state, |
| 1385 | const char *name, |
| 1386 | int (*startup)(unsigned int cpu), |
| 1387 | int (*teardown)(unsigned int cpu)) |
| 1388 | { |
| 1389 | /* (Un)Install the callbacks for further cpu hotplug operations */ |
| 1390 | struct cpuhp_step *sp; |
| 1391 | |
| 1392 | mutex_lock(&cpuhp_state_mutex); |
| 1393 | sp = cpuhp_get_step(state); |
| 1394 | sp->startup = startup; |
| 1395 | sp->teardown = teardown; |
| 1396 | sp->name = name; |
| 1397 | mutex_unlock(&cpuhp_state_mutex); |
| 1398 | } |
| 1399 | |
| 1400 | static void *cpuhp_get_teardown_cb(enum cpuhp_state state) |
| 1401 | { |
| 1402 | return cpuhp_get_step(state)->teardown; |
| 1403 | } |
| 1404 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1405 | /* |
| 1406 | * Call the startup/teardown function for a step either on the AP or |
| 1407 | * on the current CPU. |
| 1408 | */ |
| 1409 | static int cpuhp_issue_call(int cpu, enum cpuhp_state state, |
| 1410 | int (*cb)(unsigned int), bool bringup) |
| 1411 | { |
| 1412 | int ret; |
| 1413 | |
| 1414 | if (!cb) |
| 1415 | return 0; |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1416 | /* |
| 1417 | * The non AP bound callbacks can fail on bringup. On teardown |
| 1418 | * e.g. module removal we crash for now. |
| 1419 | */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1420 | #ifdef CONFIG_SMP |
| 1421 | if (cpuhp_is_ap_state(state)) |
| 1422 | ret = cpuhp_invoke_ap_callback(cpu, state, cb); |
| 1423 | else |
| 1424 | ret = cpuhp_invoke_callback(cpu, state, cb); |
| 1425 | #else |
| 1426 | ret = cpuhp_invoke_callback(cpu, state, cb); |
| 1427 | #endif |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1428 | BUG_ON(ret && !bringup); |
| 1429 | return ret; |
| 1430 | } |
| 1431 | |
| 1432 | /* |
| 1433 | * Called from __cpuhp_setup_state on a recoverable failure. |
| 1434 | * |
| 1435 | * Note: The teardown callbacks for rollback are not allowed to fail! |
| 1436 | */ |
| 1437 | static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state, |
| 1438 | int (*teardown)(unsigned int cpu)) |
| 1439 | { |
| 1440 | int cpu; |
| 1441 | |
| 1442 | if (!teardown) |
| 1443 | return; |
| 1444 | |
| 1445 | /* Roll back the already executed steps on the other cpus */ |
| 1446 | for_each_present_cpu(cpu) { |
| 1447 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1448 | int cpustate = st->state; |
| 1449 | |
| 1450 | if (cpu >= failedcpu) |
| 1451 | break; |
| 1452 | |
| 1453 | /* Did we invoke the startup call on that cpu ? */ |
| 1454 | if (cpustate >= state) |
| 1455 | cpuhp_issue_call(cpu, state, teardown, false); |
| 1456 | } |
| 1457 | } |
| 1458 | |
| 1459 | /* |
| 1460 | * Returns a free for dynamic slot assignment of the Online state. The states |
| 1461 | * are protected by the cpuhp_slot_states mutex and an empty slot is identified |
| 1462 | * by having no name assigned. |
| 1463 | */ |
| 1464 | static int cpuhp_reserve_state(enum cpuhp_state state) |
| 1465 | { |
| 1466 | enum cpuhp_state i; |
| 1467 | |
| 1468 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1469 | for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) { |
| 1470 | if (cpuhp_ap_states[i].name) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1471 | continue; |
| 1472 | |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1473 | cpuhp_ap_states[i].name = "Reserved"; |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1474 | mutex_unlock(&cpuhp_state_mutex); |
| 1475 | return i; |
| 1476 | } |
| 1477 | mutex_unlock(&cpuhp_state_mutex); |
| 1478 | WARN(1, "No more dynamic states available for CPU hotplug\n"); |
| 1479 | return -ENOSPC; |
| 1480 | } |
| 1481 | |
| 1482 | /** |
| 1483 | * __cpuhp_setup_state - Setup the callbacks for an hotplug machine state |
| 1484 | * @state: The state to setup |
| 1485 | * @invoke: If true, the startup function is invoked for cpus where |
| 1486 | * cpu state >= @state |
| 1487 | * @startup: startup callback function |
| 1488 | * @teardown: teardown callback function |
| 1489 | * |
| 1490 | * Returns 0 if successful, otherwise a proper error code |
| 1491 | */ |
| 1492 | int __cpuhp_setup_state(enum cpuhp_state state, |
| 1493 | const char *name, bool invoke, |
| 1494 | int (*startup)(unsigned int cpu), |
| 1495 | int (*teardown)(unsigned int cpu)) |
| 1496 | { |
| 1497 | int cpu, ret = 0; |
| 1498 | int dyn_state = 0; |
| 1499 | |
| 1500 | if (cpuhp_cb_check(state) || !name) |
| 1501 | return -EINVAL; |
| 1502 | |
| 1503 | get_online_cpus(); |
| 1504 | |
| 1505 | /* currently assignments for the ONLINE state are possible */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1506 | if (state == CPUHP_AP_ONLINE_DYN) { |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1507 | dyn_state = 1; |
| 1508 | ret = cpuhp_reserve_state(state); |
| 1509 | if (ret < 0) |
| 1510 | goto out; |
| 1511 | state = ret; |
| 1512 | } |
| 1513 | |
| 1514 | cpuhp_store_callbacks(state, name, startup, teardown); |
| 1515 | |
| 1516 | if (!invoke || !startup) |
| 1517 | goto out; |
| 1518 | |
| 1519 | /* |
| 1520 | * Try to call the startup callback for each present cpu |
| 1521 | * depending on the hotplug state of the cpu. |
| 1522 | */ |
| 1523 | for_each_present_cpu(cpu) { |
| 1524 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1525 | int cpustate = st->state; |
| 1526 | |
| 1527 | if (cpustate < state) |
| 1528 | continue; |
| 1529 | |
| 1530 | ret = cpuhp_issue_call(cpu, state, startup, true); |
| 1531 | if (ret) { |
| 1532 | cpuhp_rollback_install(cpu, state, teardown); |
| 1533 | cpuhp_store_callbacks(state, NULL, NULL, NULL); |
| 1534 | goto out; |
| 1535 | } |
| 1536 | } |
| 1537 | out: |
| 1538 | put_online_cpus(); |
| 1539 | if (!ret && dyn_state) |
| 1540 | return state; |
| 1541 | return ret; |
| 1542 | } |
| 1543 | EXPORT_SYMBOL(__cpuhp_setup_state); |
| 1544 | |
| 1545 | /** |
| 1546 | * __cpuhp_remove_state - Remove the callbacks for an hotplug machine state |
| 1547 | * @state: The state to remove |
| 1548 | * @invoke: If true, the teardown function is invoked for cpus where |
| 1549 | * cpu state >= @state |
| 1550 | * |
| 1551 | * The teardown callback is currently not allowed to fail. Think |
| 1552 | * about module removal! |
| 1553 | */ |
| 1554 | void __cpuhp_remove_state(enum cpuhp_state state, bool invoke) |
| 1555 | { |
| 1556 | int (*teardown)(unsigned int cpu) = cpuhp_get_teardown_cb(state); |
| 1557 | int cpu; |
| 1558 | |
| 1559 | BUG_ON(cpuhp_cb_check(state)); |
| 1560 | |
| 1561 | get_online_cpus(); |
| 1562 | |
| 1563 | if (!invoke || !teardown) |
| 1564 | goto remove; |
| 1565 | |
| 1566 | /* |
| 1567 | * Call the teardown callback for each present cpu depending |
| 1568 | * on the hotplug state of the cpu. This function is not |
| 1569 | * allowed to fail currently! |
| 1570 | */ |
| 1571 | for_each_present_cpu(cpu) { |
| 1572 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1573 | int cpustate = st->state; |
| 1574 | |
| 1575 | if (cpustate >= state) |
| 1576 | cpuhp_issue_call(cpu, state, teardown, false); |
| 1577 | } |
| 1578 | remove: |
| 1579 | cpuhp_store_callbacks(state, NULL, NULL, NULL); |
| 1580 | put_online_cpus(); |
| 1581 | } |
| 1582 | EXPORT_SYMBOL(__cpuhp_remove_state); |
| 1583 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1584 | #if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU) |
| 1585 | static ssize_t show_cpuhp_state(struct device *dev, |
| 1586 | struct device_attribute *attr, char *buf) |
| 1587 | { |
| 1588 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1589 | |
| 1590 | return sprintf(buf, "%d\n", st->state); |
| 1591 | } |
| 1592 | static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL); |
| 1593 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1594 | static ssize_t write_cpuhp_target(struct device *dev, |
| 1595 | struct device_attribute *attr, |
| 1596 | const char *buf, size_t count) |
| 1597 | { |
| 1598 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1599 | struct cpuhp_step *sp; |
| 1600 | int target, ret; |
| 1601 | |
| 1602 | ret = kstrtoint(buf, 10, &target); |
| 1603 | if (ret) |
| 1604 | return ret; |
| 1605 | |
| 1606 | #ifdef CONFIG_CPU_HOTPLUG_STATE_CONTROL |
| 1607 | if (target < CPUHP_OFFLINE || target > CPUHP_ONLINE) |
| 1608 | return -EINVAL; |
| 1609 | #else |
| 1610 | if (target != CPUHP_OFFLINE && target != CPUHP_ONLINE) |
| 1611 | return -EINVAL; |
| 1612 | #endif |
| 1613 | |
| 1614 | ret = lock_device_hotplug_sysfs(); |
| 1615 | if (ret) |
| 1616 | return ret; |
| 1617 | |
| 1618 | mutex_lock(&cpuhp_state_mutex); |
| 1619 | sp = cpuhp_get_step(target); |
| 1620 | ret = !sp->name || sp->cant_stop ? -EINVAL : 0; |
| 1621 | mutex_unlock(&cpuhp_state_mutex); |
| 1622 | if (ret) |
| 1623 | return ret; |
| 1624 | |
| 1625 | if (st->state < target) |
| 1626 | ret = do_cpu_up(dev->id, target); |
| 1627 | else |
| 1628 | ret = do_cpu_down(dev->id, target); |
| 1629 | |
| 1630 | unlock_device_hotplug(); |
| 1631 | return ret ? ret : count; |
| 1632 | } |
| 1633 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1634 | static ssize_t show_cpuhp_target(struct device *dev, |
| 1635 | struct device_attribute *attr, char *buf) |
| 1636 | { |
| 1637 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1638 | |
| 1639 | return sprintf(buf, "%d\n", st->target); |
| 1640 | } |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1641 | static DEVICE_ATTR(target, 0644, show_cpuhp_target, write_cpuhp_target); |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1642 | |
| 1643 | static struct attribute *cpuhp_cpu_attrs[] = { |
| 1644 | &dev_attr_state.attr, |
| 1645 | &dev_attr_target.attr, |
| 1646 | NULL |
| 1647 | }; |
| 1648 | |
| 1649 | static struct attribute_group cpuhp_cpu_attr_group = { |
| 1650 | .attrs = cpuhp_cpu_attrs, |
| 1651 | .name = "hotplug", |
| 1652 | NULL |
| 1653 | }; |
| 1654 | |
| 1655 | static ssize_t show_cpuhp_states(struct device *dev, |
| 1656 | struct device_attribute *attr, char *buf) |
| 1657 | { |
| 1658 | ssize_t cur, res = 0; |
| 1659 | int i; |
| 1660 | |
| 1661 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1662 | for (i = CPUHP_OFFLINE; i <= CPUHP_ONLINE; i++) { |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1663 | struct cpuhp_step *sp = cpuhp_get_step(i); |
| 1664 | |
| 1665 | if (sp->name) { |
| 1666 | cur = sprintf(buf, "%3d: %s\n", i, sp->name); |
| 1667 | buf += cur; |
| 1668 | res += cur; |
| 1669 | } |
| 1670 | } |
| 1671 | mutex_unlock(&cpuhp_state_mutex); |
| 1672 | return res; |
| 1673 | } |
| 1674 | static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL); |
| 1675 | |
| 1676 | static struct attribute *cpuhp_cpu_root_attrs[] = { |
| 1677 | &dev_attr_states.attr, |
| 1678 | NULL |
| 1679 | }; |
| 1680 | |
| 1681 | static struct attribute_group cpuhp_cpu_root_attr_group = { |
| 1682 | .attrs = cpuhp_cpu_root_attrs, |
| 1683 | .name = "hotplug", |
| 1684 | NULL |
| 1685 | }; |
| 1686 | |
| 1687 | static int __init cpuhp_sysfs_init(void) |
| 1688 | { |
| 1689 | int cpu, ret; |
| 1690 | |
| 1691 | ret = sysfs_create_group(&cpu_subsys.dev_root->kobj, |
| 1692 | &cpuhp_cpu_root_attr_group); |
| 1693 | if (ret) |
| 1694 | return ret; |
| 1695 | |
| 1696 | for_each_possible_cpu(cpu) { |
| 1697 | struct device *dev = get_cpu_device(cpu); |
| 1698 | |
| 1699 | if (!dev) |
| 1700 | continue; |
| 1701 | ret = sysfs_create_group(&dev->kobj, &cpuhp_cpu_attr_group); |
| 1702 | if (ret) |
| 1703 | return ret; |
| 1704 | } |
| 1705 | return 0; |
| 1706 | } |
| 1707 | device_initcall(cpuhp_sysfs_init); |
| 1708 | #endif |
| 1709 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1710 | /* |
| 1711 | * cpu_bit_bitmap[] is a special, "compressed" data structure that |
| 1712 | * represents all NR_CPUS bits binary values of 1<<nr. |
| 1713 | * |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1714 | * It is used by cpumask_of() to get a constant address to a CPU |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1715 | * mask value that has a single bit set only. |
| 1716 | */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1717 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1718 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 1719 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1720 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) |
| 1721 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) |
| 1722 | #define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4) |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1723 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1724 | const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = { |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1725 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1726 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), |
| 1727 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), |
| 1728 | #if BITS_PER_LONG > 32 |
| 1729 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), |
| 1730 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1731 | #endif |
| 1732 | }; |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1733 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1734 | |
| 1735 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; |
| 1736 | EXPORT_SYMBOL(cpu_all_bits); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1737 | |
| 1738 | #ifdef CONFIG_INIT_ALL_POSSIBLE |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1739 | struct cpumask __cpu_possible_mask __read_mostly |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1740 | = {CPU_BITS_ALL}; |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1741 | #else |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1742 | struct cpumask __cpu_possible_mask __read_mostly; |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1743 | #endif |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1744 | EXPORT_SYMBOL(__cpu_possible_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1745 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1746 | struct cpumask __cpu_online_mask __read_mostly; |
| 1747 | EXPORT_SYMBOL(__cpu_online_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1748 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1749 | struct cpumask __cpu_present_mask __read_mostly; |
| 1750 | EXPORT_SYMBOL(__cpu_present_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1751 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1752 | struct cpumask __cpu_active_mask __read_mostly; |
| 1753 | EXPORT_SYMBOL(__cpu_active_mask); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1754 | |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1755 | void init_cpu_present(const struct cpumask *src) |
| 1756 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1757 | cpumask_copy(&__cpu_present_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1758 | } |
| 1759 | |
| 1760 | void init_cpu_possible(const struct cpumask *src) |
| 1761 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1762 | cpumask_copy(&__cpu_possible_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1763 | } |
| 1764 | |
| 1765 | void init_cpu_online(const struct cpumask *src) |
| 1766 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1767 | cpumask_copy(&__cpu_online_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1768 | } |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1769 | |
| 1770 | /* |
| 1771 | * Activate the first processor. |
| 1772 | */ |
| 1773 | void __init boot_cpu_init(void) |
| 1774 | { |
| 1775 | int cpu = smp_processor_id(); |
| 1776 | |
| 1777 | /* Mark the boot cpu "present", "online" etc for SMP and UP case */ |
| 1778 | set_cpu_online(cpu, true); |
| 1779 | set_cpu_active(cpu, true); |
| 1780 | set_cpu_present(cpu, true); |
| 1781 | set_cpu_possible(cpu, true); |
| 1782 | } |
| 1783 | |
| 1784 | /* |
| 1785 | * Must be called _AFTER_ setting up the per_cpu areas |
| 1786 | */ |
| 1787 | void __init boot_cpu_state_init(void) |
| 1788 | { |
| 1789 | per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE; |
| 1790 | } |