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 | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 25 | |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 26 | #include <trace/events/power.h> |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 27 | #define CREATE_TRACE_POINTS |
| 28 | #include <trace/events/cpuhp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 30 | #include "smpboot.h" |
| 31 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 32 | /** |
| 33 | * cpuhp_cpu_state - Per cpu hotplug state storage |
| 34 | * @state: The current cpu state |
| 35 | * @target: The target state |
| 36 | */ |
| 37 | struct cpuhp_cpu_state { |
| 38 | enum cpuhp_state state; |
| 39 | enum cpuhp_state target; |
| 40 | }; |
| 41 | |
| 42 | static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state); |
| 43 | |
| 44 | /** |
| 45 | * cpuhp_step - Hotplug state machine step |
| 46 | * @name: Name of the step |
| 47 | * @startup: Startup function of the step |
| 48 | * @teardown: Teardown function of the step |
| 49 | * @skip_onerr: Do not invoke the functions on error rollback |
| 50 | * Will go away once the notifiers are gone |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 51 | * @cant_stop: Bringup/teardown can't be stopped at this step |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 52 | */ |
| 53 | struct cpuhp_step { |
| 54 | const char *name; |
| 55 | int (*startup)(unsigned int cpu); |
| 56 | int (*teardown)(unsigned int cpu); |
| 57 | bool skip_onerr; |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 58 | bool cant_stop; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 59 | }; |
| 60 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 61 | static DEFINE_MUTEX(cpuhp_state_mutex); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 62 | static struct cpuhp_step cpuhp_bp_states[]; |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 63 | static struct cpuhp_step cpuhp_ap_states[]; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 64 | |
| 65 | /** |
| 66 | * cpuhp_invoke_callback _ Invoke the callbacks for a given state |
| 67 | * @cpu: The cpu for which the callback should be invoked |
| 68 | * @step: The step in the state machine |
| 69 | * @cb: The callback function to invoke |
| 70 | * |
| 71 | * Called from cpu hotplug and from the state register machinery |
| 72 | */ |
| 73 | static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state step, |
| 74 | int (*cb)(unsigned int)) |
| 75 | { |
| 76 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 77 | int ret = 0; |
| 78 | |
| 79 | if (cb) { |
| 80 | trace_cpuhp_enter(cpu, st->target, step, cb); |
| 81 | ret = cb(cpu); |
| 82 | trace_cpuhp_exit(cpu, st->state, step, ret); |
| 83 | } |
| 84 | return ret; |
| 85 | } |
| 86 | |
Rusty Russell | 98a79d6 | 2008-12-13 21:19:41 +1030 | [diff] [blame] | 87 | #ifdef CONFIG_SMP |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 88 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 89 | static DEFINE_MUTEX(cpu_add_remove_lock); |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 90 | bool cpuhp_tasks_frozen; |
| 91 | EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 93 | /* |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 94 | * The following two APIs (cpu_maps_update_begin/done) must be used when |
| 95 | * attempting to serialize the updates to cpu_online_mask & cpu_present_mask. |
| 96 | * The APIs cpu_notifier_register_begin/done() must be used to protect CPU |
| 97 | * hotplug callback (un)registration performed using __register_cpu_notifier() |
| 98 | * or __unregister_cpu_notifier(). |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 99 | */ |
| 100 | void cpu_maps_update_begin(void) |
| 101 | { |
| 102 | mutex_lock(&cpu_add_remove_lock); |
| 103 | } |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 104 | EXPORT_SYMBOL(cpu_notifier_register_begin); |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 105 | |
| 106 | void cpu_maps_update_done(void) |
| 107 | { |
| 108 | mutex_unlock(&cpu_add_remove_lock); |
| 109 | } |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 110 | EXPORT_SYMBOL(cpu_notifier_register_done); |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 111 | |
Daniel J Blueman | 5c113fb | 2010-06-01 12:15:11 +0100 | [diff] [blame] | 112 | static RAW_NOTIFIER_HEAD(cpu_chain); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 114 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
| 115 | * Should always be manipulated under cpu_add_remove_lock |
| 116 | */ |
| 117 | static int cpu_hotplug_disabled; |
| 118 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 119 | #ifdef CONFIG_HOTPLUG_CPU |
| 120 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 121 | static struct { |
| 122 | struct task_struct *active_writer; |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 123 | /* wait queue to wake up the active_writer */ |
| 124 | wait_queue_head_t wq; |
| 125 | /* verifies that no writer will get active while readers are active */ |
| 126 | struct mutex lock; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 127 | /* |
| 128 | * Also blocks the new readers during |
| 129 | * an ongoing cpu hotplug operation. |
| 130 | */ |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 131 | atomic_t refcount; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 132 | |
| 133 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| 134 | struct lockdep_map dep_map; |
| 135 | #endif |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 136 | } cpu_hotplug = { |
| 137 | .active_writer = NULL, |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 138 | .wq = __WAIT_QUEUE_HEAD_INITIALIZER(cpu_hotplug.wq), |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 139 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 140 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| 141 | .dep_map = {.name = "cpu_hotplug.lock" }, |
| 142 | #endif |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 143 | }; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 144 | |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 145 | /* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */ |
| 146 | #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] | 147 | #define cpuhp_lock_acquire_tryread() \ |
| 148 | lock_map_acquire_tryread(&cpu_hotplug.dep_map) |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 149 | #define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map) |
| 150 | #define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map) |
| 151 | |
Paul E. McKenney | 62db99f | 2014-10-22 14:51:49 -0700 | [diff] [blame] | 152 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 153 | void get_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 154 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 155 | might_sleep(); |
| 156 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 157 | return; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 158 | cpuhp_lock_acquire_read(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 159 | mutex_lock(&cpu_hotplug.lock); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 160 | atomic_inc(&cpu_hotplug.refcount); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 161 | mutex_unlock(&cpu_hotplug.lock); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 162 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 163 | EXPORT_SYMBOL_GPL(get_online_cpus); |
Ashok Raj | 90d45d1 | 2005-11-08 21:34:24 -0800 | [diff] [blame] | 164 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 165 | void put_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 166 | { |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 167 | int refcount; |
| 168 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 169 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 170 | return; |
Srivatsa S. Bhat | 075663d | 2012-10-08 16:28:20 -0700 | [diff] [blame] | 171 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 172 | refcount = atomic_dec_return(&cpu_hotplug.refcount); |
| 173 | if (WARN_ON(refcount < 0)) /* try to fix things up */ |
| 174 | atomic_inc(&cpu_hotplug.refcount); |
Srivatsa S. Bhat | 075663d | 2012-10-08 16:28:20 -0700 | [diff] [blame] | 175 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 176 | if (refcount <= 0 && waitqueue_active(&cpu_hotplug.wq)) |
| 177 | wake_up(&cpu_hotplug.wq); |
| 178 | |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 179 | cpuhp_lock_release(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 180 | |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 181 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 182 | EXPORT_SYMBOL_GPL(put_online_cpus); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 183 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 184 | /* |
| 185 | * This ensures that the hotplug operation can begin only when the |
| 186 | * refcount goes to zero. |
| 187 | * |
| 188 | * Note that during a cpu-hotplug operation, the new readers, if any, |
| 189 | * will be blocked by the cpu_hotplug.lock |
| 190 | * |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 191 | * Since cpu_hotplug_begin() is always called after invoking |
| 192 | * 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] | 193 | * |
| 194 | * Note that theoretically, there is a possibility of a livelock: |
| 195 | * - Refcount goes to zero, last reader wakes up the sleeping |
| 196 | * writer. |
| 197 | * - Last reader unlocks the cpu_hotplug.lock. |
| 198 | * - A new reader arrives at this moment, bumps up the refcount. |
| 199 | * - The writer acquires the cpu_hotplug.lock finds the refcount |
| 200 | * non zero and goes to sleep again. |
| 201 | * |
| 202 | * However, this is very difficult to achieve in practice since |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 203 | * 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] | 204 | * |
| 205 | */ |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 206 | void cpu_hotplug_begin(void) |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 207 | { |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 208 | DEFINE_WAIT(wait); |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 209 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 210 | cpu_hotplug.active_writer = current; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 211 | cpuhp_lock_acquire(); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 212 | |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 213 | for (;;) { |
| 214 | mutex_lock(&cpu_hotplug.lock); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 215 | prepare_to_wait(&cpu_hotplug.wq, &wait, TASK_UNINTERRUPTIBLE); |
| 216 | if (likely(!atomic_read(&cpu_hotplug.refcount))) |
| 217 | break; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 218 | mutex_unlock(&cpu_hotplug.lock); |
| 219 | schedule(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 220 | } |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 221 | finish_wait(&cpu_hotplug.wq, &wait); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 222 | } |
| 223 | |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 224 | void cpu_hotplug_done(void) |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 225 | { |
| 226 | cpu_hotplug.active_writer = NULL; |
| 227 | mutex_unlock(&cpu_hotplug.lock); |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 228 | cpuhp_lock_release(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 229 | } |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 230 | |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 231 | /* |
| 232 | * Wait for currently running CPU hotplug operations to complete (if any) and |
| 233 | * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects |
| 234 | * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the |
| 235 | * hotplug path before performing hotplug operations. So acquiring that lock |
| 236 | * guarantees mutual exclusion from any currently running hotplug operations. |
| 237 | */ |
| 238 | void cpu_hotplug_disable(void) |
| 239 | { |
| 240 | cpu_maps_update_begin(); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 241 | cpu_hotplug_disabled++; |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 242 | cpu_maps_update_done(); |
| 243 | } |
Vitaly Kuznetsov | 32145c4 | 2015-08-05 00:52:47 -0700 | [diff] [blame] | 244 | EXPORT_SYMBOL_GPL(cpu_hotplug_disable); |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 245 | |
| 246 | void cpu_hotplug_enable(void) |
| 247 | { |
| 248 | cpu_maps_update_begin(); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 249 | WARN_ON(--cpu_hotplug_disabled < 0); |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 250 | cpu_maps_update_done(); |
| 251 | } |
Vitaly Kuznetsov | 32145c4 | 2015-08-05 00:52:47 -0700 | [diff] [blame] | 252 | EXPORT_SYMBOL_GPL(cpu_hotplug_enable); |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 253 | #endif /* CONFIG_HOTPLUG_CPU */ |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 254 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | /* Need to know about CPUs going up/down? */ |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 256 | int register_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | { |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 258 | int ret; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 259 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 260 | ret = raw_notifier_chain_register(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 261 | cpu_maps_update_done(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 262 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 263 | } |
Chandra Seetharaman | 65edc68 | 2006-06-27 02:54:08 -0700 | [diff] [blame] | 264 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 265 | int __register_cpu_notifier(struct notifier_block *nb) |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 266 | { |
| 267 | return raw_notifier_chain_register(&cpu_chain, nb); |
| 268 | } |
| 269 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 270 | 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] | 271 | int *nr_calls) |
| 272 | { |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 273 | unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0; |
| 274 | void *hcpu = (void *)(long)cpu; |
| 275 | |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 276 | int ret; |
| 277 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 278 | 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] | 279 | nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 280 | |
| 281 | return notifier_to_errno(ret); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 282 | } |
| 283 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 284 | static int cpu_notify(unsigned long val, unsigned int cpu) |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 285 | { |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 286 | return __cpu_notify(val, cpu, -1, NULL); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 287 | } |
| 288 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 289 | /* Notifier wrappers for transitioning to state machine */ |
| 290 | static int notify_prepare(unsigned int cpu) |
| 291 | { |
| 292 | int nr_calls = 0; |
| 293 | int ret; |
| 294 | |
| 295 | ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls); |
| 296 | if (ret) { |
| 297 | nr_calls--; |
| 298 | printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", |
| 299 | __func__, cpu); |
| 300 | __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL); |
| 301 | } |
| 302 | return ret; |
| 303 | } |
| 304 | |
| 305 | static int notify_online(unsigned int cpu) |
| 306 | { |
| 307 | cpu_notify(CPU_ONLINE, cpu); |
| 308 | return 0; |
| 309 | } |
| 310 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 311 | static int notify_starting(unsigned int cpu) |
| 312 | { |
| 313 | cpu_notify(CPU_STARTING, cpu); |
| 314 | return 0; |
| 315 | } |
| 316 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 317 | static int bringup_cpu(unsigned int cpu) |
| 318 | { |
| 319 | struct task_struct *idle = idle_thread_get(cpu); |
| 320 | int ret; |
| 321 | |
| 322 | /* Arch-specific enabling code. */ |
| 323 | ret = __cpu_up(cpu, idle); |
| 324 | if (ret) { |
| 325 | cpu_notify(CPU_UP_CANCELED, cpu); |
| 326 | return ret; |
| 327 | } |
| 328 | BUG_ON(!cpu_online(cpu)); |
| 329 | return 0; |
| 330 | } |
| 331 | |
Linus Torvalds | 00b9b0a | 2010-05-27 10:32:08 -0700 | [diff] [blame] | 332 | #ifdef CONFIG_HOTPLUG_CPU |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | EXPORT_SYMBOL(register_cpu_notifier); |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 334 | EXPORT_SYMBOL(__register_cpu_notifier); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 336 | void unregister_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 338 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 339 | raw_notifier_chain_unregister(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 340 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | } |
| 342 | EXPORT_SYMBOL(unregister_cpu_notifier); |
| 343 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 344 | void __unregister_cpu_notifier(struct notifier_block *nb) |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 345 | { |
| 346 | raw_notifier_chain_unregister(&cpu_chain, nb); |
| 347 | } |
| 348 | EXPORT_SYMBOL(__unregister_cpu_notifier); |
| 349 | |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 350 | /** |
| 351 | * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU |
| 352 | * @cpu: a CPU id |
| 353 | * |
| 354 | * This function walks all processes, finds a valid mm struct for each one and |
| 355 | * then clears a corresponding bit in mm's cpumask. While this all sounds |
| 356 | * trivial, there are various non-obvious corner cases, which this function |
| 357 | * tries to solve in a safe manner. |
| 358 | * |
| 359 | * Also note that the function uses a somewhat relaxed locking scheme, so it may |
| 360 | * be called only for an already offlined CPU. |
| 361 | */ |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 362 | void clear_tasks_mm_cpumask(int cpu) |
| 363 | { |
| 364 | struct task_struct *p; |
| 365 | |
| 366 | /* |
| 367 | * This function is called after the cpu is taken down and marked |
| 368 | * offline, so its not like new tasks will ever get this cpu set in |
| 369 | * their mm mask. -- Peter Zijlstra |
| 370 | * Thus, we may use rcu_read_lock() here, instead of grabbing |
| 371 | * full-fledged tasklist_lock. |
| 372 | */ |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 373 | WARN_ON(cpu_online(cpu)); |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 374 | rcu_read_lock(); |
| 375 | for_each_process(p) { |
| 376 | struct task_struct *t; |
| 377 | |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 378 | /* |
| 379 | * Main thread might exit, but other threads may still have |
| 380 | * a valid mm. Find one. |
| 381 | */ |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 382 | t = find_lock_task_mm(p); |
| 383 | if (!t) |
| 384 | continue; |
| 385 | cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); |
| 386 | task_unlock(t); |
| 387 | } |
| 388 | rcu_read_unlock(); |
| 389 | } |
| 390 | |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 391 | static inline void check_for_tasks(int dead_cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | { |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 393 | struct task_struct *g, *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 394 | |
Oleg Nesterov | a75a606 | 2015-09-10 15:07:50 +0200 | [diff] [blame] | 395 | read_lock(&tasklist_lock); |
| 396 | for_each_process_thread(g, p) { |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 397 | if (!p->on_rq) |
| 398 | continue; |
| 399 | /* |
| 400 | * We do the check with unlocked task_rq(p)->lock. |
| 401 | * Order the reading to do not warn about a task, |
| 402 | * which was running on this cpu in the past, and |
| 403 | * it's just been woken on another cpu. |
| 404 | */ |
| 405 | rmb(); |
| 406 | if (task_cpu(p) != dead_cpu) |
| 407 | continue; |
| 408 | |
| 409 | pr_warn("Task %s (pid=%d) is on cpu %d (state=%ld, flags=%x)\n", |
| 410 | p->comm, task_pid_nr(p), dead_cpu, p->state, p->flags); |
Oleg Nesterov | a75a606 | 2015-09-10 15:07:50 +0200 | [diff] [blame] | 411 | } |
| 412 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | } |
| 414 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 415 | static void cpu_notify_nofail(unsigned long val, unsigned int cpu) |
| 416 | { |
| 417 | BUG_ON(cpu_notify(val, cpu)); |
| 418 | } |
| 419 | |
| 420 | static int notify_down_prepare(unsigned int cpu) |
| 421 | { |
| 422 | int err, nr_calls = 0; |
| 423 | |
| 424 | err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls); |
| 425 | if (err) { |
| 426 | nr_calls--; |
| 427 | __cpu_notify(CPU_DOWN_FAILED, cpu, nr_calls, NULL); |
| 428 | pr_warn("%s: attempt to take down CPU %u failed\n", |
| 429 | __func__, cpu); |
| 430 | } |
| 431 | return err; |
| 432 | } |
| 433 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 434 | static int notify_dying(unsigned int cpu) |
| 435 | { |
| 436 | cpu_notify(CPU_DYING, cpu); |
| 437 | return 0; |
| 438 | } |
| 439 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | /* Take this CPU down. */ |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 441 | static int take_cpu_down(void *_param) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | { |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 443 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 444 | enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE); |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 445 | int err, cpu = smp_processor_id(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | /* Ensure this CPU doesn't handle any more interrupts. */ |
| 448 | err = __cpu_disable(); |
| 449 | if (err < 0) |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 450 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 452 | /* Invoke the former CPU_DYING callbacks */ |
| 453 | for (; st->state > target; st->state--) { |
| 454 | struct cpuhp_step *step = cpuhp_ap_states + st->state; |
| 455 | |
| 456 | cpuhp_invoke_callback(cpu, st->state, step->teardown); |
| 457 | } |
Thomas Gleixner | 52c063d | 2015-04-03 02:37:24 +0200 | [diff] [blame] | 458 | /* Give up timekeeping duties */ |
| 459 | tick_handover_do_timer(); |
Thomas Gleixner | 14e568e | 2013-01-31 12:11:14 +0000 | [diff] [blame] | 460 | /* Park the stopper thread */ |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 461 | stop_machine_park(cpu); |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 462 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | } |
| 464 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 465 | static int takedown_cpu(unsigned int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | { |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 467 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 469 | /* |
| 470 | * By now we've cleared cpu_active_mask, wait for all preempt-disabled |
| 471 | * and RCU users of this state to go away such that all new such users |
| 472 | * will observe it. |
| 473 | * |
| 474 | * For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might |
Paul E. McKenney | 779de6c | 2015-06-10 13:34:41 -0700 | [diff] [blame] | 475 | * not imply sync_sched(), so wait for both. |
Michael wang | 106dd5a | 2013-11-13 11:10:56 +0800 | [diff] [blame] | 476 | * |
| 477 | * Do sync before park smpboot threads to take care the rcu boost case. |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 478 | */ |
Paul E. McKenney | 779de6c | 2015-06-10 13:34:41 -0700 | [diff] [blame] | 479 | if (IS_ENABLED(CONFIG_PREEMPT)) |
| 480 | synchronize_rcu_mult(call_rcu, call_rcu_sched); |
| 481 | else |
| 482 | synchronize_rcu(); |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 483 | |
Michael wang | 106dd5a | 2013-11-13 11:10:56 +0800 | [diff] [blame] | 484 | smpboot_park_threads(cpu); |
| 485 | |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 486 | /* |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 487 | * Prevent irq alloc/free while the dying cpu reorganizes the |
| 488 | * interrupt affinities. |
| 489 | */ |
| 490 | irq_lock_sparse(); |
| 491 | |
| 492 | /* |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 493 | * So now all preempt/rcu users must observe !cpu_active(). |
| 494 | */ |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 495 | err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu)); |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 496 | if (err) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 497 | /* CPU didn't die: tell everyone. Can't complain. */ |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 498 | cpu_notify_nofail(CPU_DOWN_FAILED, cpu); |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 499 | irq_unlock_sparse(); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 500 | return err; |
Satoru Takeuchi | 8fa1d7d | 2006-10-28 10:38:57 -0700 | [diff] [blame] | 501 | } |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 502 | BUG_ON(cpu_online(cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 504 | /* |
| 505 | * The migration_call() CPU_DYING callback will have removed all |
| 506 | * runnable tasks from the cpu, there's only the idle task left now |
| 507 | * that the migration thread is done doing the stop_machine thing. |
Peter Zijlstra | 51a96c7 | 2010-11-19 20:37:53 +0100 | [diff] [blame] | 508 | * |
| 509 | * Wait for the stop thread to go away. |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 510 | */ |
Paul E. McKenney | 528a25b | 2015-01-28 14:09:43 -0800 | [diff] [blame] | 511 | while (!per_cpu(cpu_dead_idle, cpu)) |
Peter Zijlstra | 51a96c7 | 2010-11-19 20:37:53 +0100 | [diff] [blame] | 512 | cpu_relax(); |
Paul E. McKenney | 528a25b | 2015-01-28 14:09:43 -0800 | [diff] [blame] | 513 | smp_mb(); /* Read from cpu_dead_idle before __cpu_die(). */ |
| 514 | per_cpu(cpu_dead_idle, cpu) = false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 516 | /* Interrupts are moved away from the dying cpu, reenable alloc/free */ |
| 517 | irq_unlock_sparse(); |
| 518 | |
Preeti U Murthy | 345527b | 2015-03-30 14:59:19 +0530 | [diff] [blame] | 519 | hotplug_cpu__broadcast_tick_pull(cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | /* This actually kills the CPU. */ |
| 521 | __cpu_die(cpu); |
| 522 | |
Thomas Gleixner | a49b116 | 2015-04-03 02:38:05 +0200 | [diff] [blame] | 523 | tick_cleanup_dead_cpu(cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 524 | return 0; |
| 525 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 527 | static int notify_dead(unsigned int cpu) |
| 528 | { |
| 529 | cpu_notify_nofail(CPU_DEAD, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | check_for_tasks(cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 531 | return 0; |
| 532 | } |
| 533 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 534 | #else |
| 535 | #define notify_down_prepare NULL |
| 536 | #define takedown_cpu NULL |
| 537 | #define notify_dead NULL |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 538 | #define notify_dying NULL |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 539 | #endif |
| 540 | |
| 541 | #ifdef CONFIG_HOTPLUG_CPU |
| 542 | static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st) |
| 543 | { |
| 544 | for (st->state++; st->state < st->target; st->state++) { |
| 545 | struct cpuhp_step *step = cpuhp_bp_states + st->state; |
| 546 | |
| 547 | if (!step->skip_onerr) |
| 548 | cpuhp_invoke_callback(cpu, st->state, step->startup); |
| 549 | } |
| 550 | } |
| 551 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 552 | /* Requires cpu_add_remove_lock to be held */ |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 553 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, |
| 554 | enum cpuhp_state target) |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 555 | { |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 556 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 557 | int prev_state, ret = 0; |
| 558 | bool hasdied = false; |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 559 | |
| 560 | if (num_online_cpus() == 1) |
| 561 | return -EBUSY; |
| 562 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 563 | if (!cpu_present(cpu)) |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 564 | return -EINVAL; |
| 565 | |
| 566 | cpu_hotplug_begin(); |
| 567 | |
| 568 | cpuhp_tasks_frozen = tasks_frozen; |
| 569 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 570 | prev_state = st->state; |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 571 | st->target = target; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 572 | for (; st->state > st->target; st->state--) { |
| 573 | struct cpuhp_step *step = cpuhp_bp_states + st->state; |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 574 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 575 | ret = cpuhp_invoke_callback(cpu, st->state, step->teardown); |
| 576 | if (ret) { |
| 577 | st->target = prev_state; |
| 578 | undo_cpu_down(cpu, st); |
| 579 | break; |
| 580 | } |
| 581 | } |
| 582 | hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 584 | cpu_hotplug_done(); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 585 | /* This post dead nonsense must die */ |
| 586 | if (!ret && hasdied) |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 587 | cpu_notify_nofail(CPU_POST_DEAD, cpu); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 588 | return ret; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 589 | } |
| 590 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 591 | 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] | 592 | { |
Heiko Carstens | 9ea09af | 2008-12-22 12:36:30 +0100 | [diff] [blame] | 593 | int err; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 594 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 595 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 596 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 597 | if (cpu_hotplug_disabled) { |
| 598 | err = -EBUSY; |
| 599 | goto out; |
| 600 | } |
| 601 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 602 | err = _cpu_down(cpu, 0, target); |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 603 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 604 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 605 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 606 | return err; |
| 607 | } |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 608 | int cpu_down(unsigned int cpu) |
| 609 | { |
| 610 | return do_cpu_down(cpu, CPUHP_OFFLINE); |
| 611 | } |
Zhang Rui | b62b8ef | 2008-04-29 02:35:56 -0400 | [diff] [blame] | 612 | EXPORT_SYMBOL(cpu_down); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | #endif /*CONFIG_HOTPLUG_CPU*/ |
| 614 | |
Paul E. McKenney | 00df35f | 2015-04-12 08:06:55 -0700 | [diff] [blame] | 615 | /* |
| 616 | * Unpark per-CPU smpboot kthreads at CPU-online time. |
| 617 | */ |
| 618 | static int smpboot_thread_call(struct notifier_block *nfb, |
| 619 | unsigned long action, void *hcpu) |
| 620 | { |
| 621 | int cpu = (long)hcpu; |
| 622 | |
| 623 | switch (action & ~CPU_TASKS_FROZEN) { |
| 624 | |
Paul E. McKenney | 64eaf974 | 2015-04-15 12:45:41 -0700 | [diff] [blame] | 625 | case CPU_DOWN_FAILED: |
Paul E. McKenney | 00df35f | 2015-04-12 08:06:55 -0700 | [diff] [blame] | 626 | case CPU_ONLINE: |
| 627 | smpboot_unpark_threads(cpu); |
| 628 | break; |
| 629 | |
| 630 | default: |
| 631 | break; |
| 632 | } |
| 633 | |
| 634 | return NOTIFY_OK; |
| 635 | } |
| 636 | |
| 637 | static struct notifier_block smpboot_thread_notifier = { |
| 638 | .notifier_call = smpboot_thread_call, |
| 639 | .priority = CPU_PRI_SMPBOOT, |
| 640 | }; |
| 641 | |
Paul Gortmaker | 927da9d | 2015-04-27 18:47:58 -0400 | [diff] [blame] | 642 | void smpboot_thread_init(void) |
Paul E. McKenney | 00df35f | 2015-04-12 08:06:55 -0700 | [diff] [blame] | 643 | { |
| 644 | register_cpu_notifier(&smpboot_thread_notifier); |
| 645 | } |
| 646 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 647 | /** |
| 648 | * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers |
| 649 | * @cpu: cpu that just started |
| 650 | * |
| 651 | * This function calls the cpu_chain notifiers with CPU_STARTING. |
| 652 | * It must be called by the arch code on the new cpu, before the new cpu |
| 653 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). |
| 654 | */ |
| 655 | void notify_cpu_starting(unsigned int cpu) |
| 656 | { |
| 657 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 658 | enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE); |
| 659 | |
| 660 | while (st->state < target) { |
| 661 | struct cpuhp_step *step; |
| 662 | |
| 663 | st->state++; |
| 664 | step = cpuhp_ap_states + st->state; |
| 665 | cpuhp_invoke_callback(cpu, st->state, step->startup); |
| 666 | } |
| 667 | } |
| 668 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 669 | static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st) |
| 670 | { |
| 671 | for (st->state--; st->state > st->target; st->state--) { |
| 672 | struct cpuhp_step *step = cpuhp_bp_states + st->state; |
| 673 | |
| 674 | if (!step->skip_onerr) |
| 675 | cpuhp_invoke_callback(cpu, st->state, step->teardown); |
| 676 | } |
| 677 | } |
| 678 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 679 | /* Requires cpu_add_remove_lock to be held */ |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 680 | 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] | 681 | { |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 682 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 683 | struct task_struct *idle; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 684 | int prev_state, ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 685 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 686 | cpu_hotplug_begin(); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 687 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 688 | if (!cpu_present(cpu)) { |
Yasuaki Ishimatsu | 5e5041f | 2012-10-23 01:30:54 +0200 | [diff] [blame] | 689 | ret = -EINVAL; |
| 690 | goto out; |
| 691 | } |
| 692 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 693 | /* |
| 694 | * The caller of do_cpu_up might have raced with another |
| 695 | * caller. Ignore it for now. |
| 696 | */ |
| 697 | if (st->state >= target) |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 698 | goto out; |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 699 | |
| 700 | if (st->state == CPUHP_OFFLINE) { |
| 701 | /* Let it fail before we try to bring the cpu up */ |
| 702 | idle = idle_thread_get(cpu); |
| 703 | if (IS_ERR(idle)) { |
| 704 | ret = PTR_ERR(idle); |
| 705 | goto out; |
| 706 | } |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 707 | } |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 708 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 709 | cpuhp_tasks_frozen = tasks_frozen; |
| 710 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 711 | prev_state = st->state; |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 712 | st->target = target; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 713 | while (st->state < st->target) { |
| 714 | struct cpuhp_step *step; |
Thomas Gleixner | f97f8f0 | 2012-07-16 10:42:36 +0000 | [diff] [blame] | 715 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 716 | st->state++; |
| 717 | step = cpuhp_bp_states + st->state; |
| 718 | ret = cpuhp_invoke_callback(cpu, st->state, step->startup); |
| 719 | if (ret) { |
| 720 | st->target = prev_state; |
| 721 | undo_cpu_up(cpu, st); |
| 722 | break; |
| 723 | } |
| 724 | } |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 725 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 726 | cpu_hotplug_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 727 | return ret; |
| 728 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 729 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 730 | 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] | 731 | { |
| 732 | int err = 0; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 733 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 734 | if (!cpu_possible(cpu)) { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 735 | pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n", |
| 736 | cpu); |
Chen Gong | 87d5e02 | 2010-03-05 13:42:38 -0800 | [diff] [blame] | 737 | #if defined(CONFIG_IA64) |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 738 | pr_err("please check additional_cpus= boot parameter\n"); |
KAMEZAWA Hiroyuki | 73e753a | 2007-10-18 23:40:47 -0700 | [diff] [blame] | 739 | #endif |
| 740 | return -EINVAL; |
| 741 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 742 | |
Toshi Kani | 01b0f19 | 2013-11-12 15:07:25 -0800 | [diff] [blame] | 743 | err = try_online_node(cpu_to_node(cpu)); |
| 744 | if (err) |
| 745 | return err; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 746 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 747 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 748 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 749 | if (cpu_hotplug_disabled) { |
| 750 | err = -EBUSY; |
| 751 | goto out; |
| 752 | } |
| 753 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 754 | err = _cpu_up(cpu, 0, target); |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 755 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 756 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 757 | return err; |
| 758 | } |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 759 | |
| 760 | int cpu_up(unsigned int cpu) |
| 761 | { |
| 762 | return do_cpu_up(cpu, CPUHP_ONLINE); |
| 763 | } |
Paul E. McKenney | a513f6b | 2011-12-11 21:54:45 -0800 | [diff] [blame] | 764 | EXPORT_SYMBOL_GPL(cpu_up); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 765 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 766 | #ifdef CONFIG_PM_SLEEP_SMP |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 767 | static cpumask_var_t frozen_cpus; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 768 | |
| 769 | int disable_nonboot_cpus(void) |
| 770 | { |
Rafael J. Wysocki | e9a5f42 | 2010-05-27 22:16:22 +0200 | [diff] [blame] | 771 | int cpu, first_cpu, error = 0; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 772 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 773 | cpu_maps_update_begin(); |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 774 | first_cpu = cpumask_first(cpu_online_mask); |
Xiaotian Feng | 9ee349a | 2009-12-16 18:04:32 +0100 | [diff] [blame] | 775 | /* |
| 776 | * 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] | 777 | * with the userspace trying to use the CPU hotplug at the same time |
| 778 | */ |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 779 | cpumask_clear(frozen_cpus); |
Peter Zijlstra | 6ad4c18 | 2009-11-25 13:31:39 +0100 | [diff] [blame] | 780 | |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 781 | pr_info("Disabling non-boot CPUs ...\n"); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 782 | for_each_online_cpu(cpu) { |
| 783 | if (cpu == first_cpu) |
| 784 | continue; |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 785 | trace_suspend_resume(TPS("CPU_OFF"), cpu, true); |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 786 | error = _cpu_down(cpu, 1, CPUHP_OFFLINE); |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 787 | trace_suspend_resume(TPS("CPU_OFF"), cpu, false); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 788 | if (!error) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 789 | cpumask_set_cpu(cpu, frozen_cpus); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 790 | else { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 791 | pr_err("Error taking CPU%d down: %d\n", cpu, error); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 792 | break; |
| 793 | } |
| 794 | } |
Joseph Cihula | 86886e5 | 2009-06-30 19:31:07 -0700 | [diff] [blame] | 795 | |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 796 | if (!error) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 797 | BUG_ON(num_online_cpus() > 1); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 798 | else |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 799 | pr_err("Non-boot CPUs are not disabled\n"); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 800 | |
| 801 | /* |
| 802 | * Make sure the CPUs won't be enabled by someone else. We need to do |
| 803 | * this even in case of failure as all disable_nonboot_cpus() users are |
| 804 | * supposed to do enable_nonboot_cpus() on the failure path. |
| 805 | */ |
| 806 | cpu_hotplug_disabled++; |
| 807 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 808 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 809 | return error; |
| 810 | } |
| 811 | |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 812 | void __weak arch_enable_nonboot_cpus_begin(void) |
| 813 | { |
| 814 | } |
| 815 | |
| 816 | void __weak arch_enable_nonboot_cpus_end(void) |
| 817 | { |
| 818 | } |
| 819 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 820 | void enable_nonboot_cpus(void) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 821 | { |
| 822 | int cpu, error; |
| 823 | |
| 824 | /* Allow everyone to use the CPU hotplug again */ |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 825 | cpu_maps_update_begin(); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 826 | WARN_ON(--cpu_hotplug_disabled < 0); |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 827 | if (cpumask_empty(frozen_cpus)) |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 828 | goto out; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 829 | |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 830 | pr_info("Enabling non-boot CPUs ...\n"); |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 831 | |
| 832 | arch_enable_nonboot_cpus_begin(); |
| 833 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 834 | for_each_cpu(cpu, frozen_cpus) { |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 835 | trace_suspend_resume(TPS("CPU_ON"), cpu, true); |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 836 | error = _cpu_up(cpu, 1, CPUHP_ONLINE); |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 837 | trace_suspend_resume(TPS("CPU_ON"), cpu, false); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 838 | if (!error) { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 839 | pr_info("CPU%d is up\n", cpu); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 840 | continue; |
| 841 | } |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 842 | pr_warn("Error taking CPU%d up: %d\n", cpu, error); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 843 | } |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 844 | |
| 845 | arch_enable_nonboot_cpus_end(); |
| 846 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 847 | cpumask_clear(frozen_cpus); |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 848 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 849 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 850 | } |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 851 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 852 | static int __init alloc_frozen_cpus(void) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 853 | { |
| 854 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) |
| 855 | return -ENOMEM; |
| 856 | return 0; |
| 857 | } |
| 858 | core_initcall(alloc_frozen_cpus); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 859 | |
| 860 | /* |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 861 | * When callbacks for CPU hotplug notifications are being executed, we must |
| 862 | * ensure that the state of the system with respect to the tasks being frozen |
| 863 | * or not, as reported by the notification, remains unchanged *throughout the |
| 864 | * duration* of the execution of the callbacks. |
| 865 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. |
| 866 | * |
| 867 | * This synchronization is implemented by mutually excluding regular CPU |
| 868 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ |
| 869 | * Hibernate notifications. |
| 870 | */ |
| 871 | static int |
| 872 | cpu_hotplug_pm_callback(struct notifier_block *nb, |
| 873 | unsigned long action, void *ptr) |
| 874 | { |
| 875 | switch (action) { |
| 876 | |
| 877 | case PM_SUSPEND_PREPARE: |
| 878 | case PM_HIBERNATION_PREPARE: |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 879 | cpu_hotplug_disable(); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 880 | break; |
| 881 | |
| 882 | case PM_POST_SUSPEND: |
| 883 | case PM_POST_HIBERNATION: |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 884 | cpu_hotplug_enable(); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 885 | break; |
| 886 | |
| 887 | default: |
| 888 | return NOTIFY_DONE; |
| 889 | } |
| 890 | |
| 891 | return NOTIFY_OK; |
| 892 | } |
| 893 | |
| 894 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 895 | static int __init cpu_hotplug_pm_sync_init(void) |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 896 | { |
Fenghua Yu | 6e32d47 | 2012-11-13 11:32:43 -0800 | [diff] [blame] | 897 | /* |
| 898 | * cpu_hotplug_pm_callback has higher priority than x86 |
| 899 | * bsp_pm_callback which depends on cpu_hotplug_pm_callback |
| 900 | * to disable cpu hotplug to avoid cpu hotplug race. |
| 901 | */ |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 902 | pm_notifier(cpu_hotplug_pm_callback, 0); |
| 903 | return 0; |
| 904 | } |
| 905 | core_initcall(cpu_hotplug_pm_sync_init); |
| 906 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 907 | #endif /* CONFIG_PM_SLEEP_SMP */ |
Max Krasnyansky | 68f4f1e | 2008-05-29 11:17:02 -0700 | [diff] [blame] | 908 | |
| 909 | #endif /* CONFIG_SMP */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 910 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 911 | /* Boot processor state steps */ |
| 912 | static struct cpuhp_step cpuhp_bp_states[] = { |
| 913 | [CPUHP_OFFLINE] = { |
| 914 | .name = "offline", |
| 915 | .startup = NULL, |
| 916 | .teardown = NULL, |
| 917 | }, |
| 918 | #ifdef CONFIG_SMP |
| 919 | [CPUHP_CREATE_THREADS]= { |
| 920 | .name = "threads:create", |
| 921 | .startup = smpboot_create_threads, |
| 922 | .teardown = NULL, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 923 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 924 | }, |
| 925 | [CPUHP_NOTIFY_PREPARE] = { |
| 926 | .name = "notify:prepare", |
| 927 | .startup = notify_prepare, |
| 928 | .teardown = notify_dead, |
| 929 | .skip_onerr = true, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 930 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 931 | }, |
| 932 | [CPUHP_BRINGUP_CPU] = { |
| 933 | .name = "cpu:bringup", |
| 934 | .startup = bringup_cpu, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 935 | .teardown = NULL, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 936 | .cant_stop = true, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 937 | }, |
| 938 | [CPUHP_TEARDOWN_CPU] = { |
| 939 | .name = "cpu:teardown", |
| 940 | .startup = NULL, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 941 | .teardown = takedown_cpu, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 942 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 943 | }, |
| 944 | [CPUHP_NOTIFY_ONLINE] = { |
| 945 | .name = "notify:online", |
| 946 | .startup = notify_online, |
| 947 | .teardown = notify_down_prepare, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 948 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 949 | }, |
| 950 | #endif |
| 951 | [CPUHP_ONLINE] = { |
| 952 | .name = "online", |
| 953 | .startup = NULL, |
| 954 | .teardown = NULL, |
| 955 | }, |
| 956 | }; |
| 957 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 958 | /* Application processor state steps */ |
| 959 | static struct cpuhp_step cpuhp_ap_states[] = { |
| 960 | #ifdef CONFIG_SMP |
| 961 | [CPUHP_AP_NOTIFY_STARTING] = { |
| 962 | .name = "notify:starting", |
| 963 | .startup = notify_starting, |
| 964 | .teardown = notify_dying, |
| 965 | .skip_onerr = true, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 966 | .cant_stop = true, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 967 | }, |
| 968 | #endif |
| 969 | [CPUHP_ONLINE] = { |
| 970 | .name = "online", |
| 971 | .startup = NULL, |
| 972 | .teardown = NULL, |
| 973 | }, |
| 974 | }; |
| 975 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 976 | static bool cpuhp_is_ap_state(enum cpuhp_state state) |
| 977 | { |
| 978 | return (state > CPUHP_AP_OFFLINE && state < CPUHP_AP_ONLINE); |
| 979 | } |
| 980 | |
| 981 | static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state) |
| 982 | { |
| 983 | struct cpuhp_step *sp; |
| 984 | |
| 985 | sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states; |
| 986 | return sp + state; |
| 987 | } |
| 988 | |
| 989 | #if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU) |
| 990 | static ssize_t show_cpuhp_state(struct device *dev, |
| 991 | struct device_attribute *attr, char *buf) |
| 992 | { |
| 993 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 994 | |
| 995 | return sprintf(buf, "%d\n", st->state); |
| 996 | } |
| 997 | static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL); |
| 998 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 999 | static ssize_t write_cpuhp_target(struct device *dev, |
| 1000 | struct device_attribute *attr, |
| 1001 | const char *buf, size_t count) |
| 1002 | { |
| 1003 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1004 | struct cpuhp_step *sp; |
| 1005 | int target, ret; |
| 1006 | |
| 1007 | ret = kstrtoint(buf, 10, &target); |
| 1008 | if (ret) |
| 1009 | return ret; |
| 1010 | |
| 1011 | #ifdef CONFIG_CPU_HOTPLUG_STATE_CONTROL |
| 1012 | if (target < CPUHP_OFFLINE || target > CPUHP_ONLINE) |
| 1013 | return -EINVAL; |
| 1014 | #else |
| 1015 | if (target != CPUHP_OFFLINE && target != CPUHP_ONLINE) |
| 1016 | return -EINVAL; |
| 1017 | #endif |
| 1018 | |
| 1019 | ret = lock_device_hotplug_sysfs(); |
| 1020 | if (ret) |
| 1021 | return ret; |
| 1022 | |
| 1023 | mutex_lock(&cpuhp_state_mutex); |
| 1024 | sp = cpuhp_get_step(target); |
| 1025 | ret = !sp->name || sp->cant_stop ? -EINVAL : 0; |
| 1026 | mutex_unlock(&cpuhp_state_mutex); |
| 1027 | if (ret) |
| 1028 | return ret; |
| 1029 | |
| 1030 | if (st->state < target) |
| 1031 | ret = do_cpu_up(dev->id, target); |
| 1032 | else |
| 1033 | ret = do_cpu_down(dev->id, target); |
| 1034 | |
| 1035 | unlock_device_hotplug(); |
| 1036 | return ret ? ret : count; |
| 1037 | } |
| 1038 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1039 | static ssize_t show_cpuhp_target(struct device *dev, |
| 1040 | struct device_attribute *attr, char *buf) |
| 1041 | { |
| 1042 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1043 | |
| 1044 | return sprintf(buf, "%d\n", st->target); |
| 1045 | } |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 1046 | static DEVICE_ATTR(target, 0644, show_cpuhp_target, write_cpuhp_target); |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1047 | |
| 1048 | static struct attribute *cpuhp_cpu_attrs[] = { |
| 1049 | &dev_attr_state.attr, |
| 1050 | &dev_attr_target.attr, |
| 1051 | NULL |
| 1052 | }; |
| 1053 | |
| 1054 | static struct attribute_group cpuhp_cpu_attr_group = { |
| 1055 | .attrs = cpuhp_cpu_attrs, |
| 1056 | .name = "hotplug", |
| 1057 | NULL |
| 1058 | }; |
| 1059 | |
| 1060 | static ssize_t show_cpuhp_states(struct device *dev, |
| 1061 | struct device_attribute *attr, char *buf) |
| 1062 | { |
| 1063 | ssize_t cur, res = 0; |
| 1064 | int i; |
| 1065 | |
| 1066 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame^] | 1067 | for (i = CPUHP_OFFLINE; i <= CPUHP_ONLINE; i++) { |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1068 | struct cpuhp_step *sp = cpuhp_get_step(i); |
| 1069 | |
| 1070 | if (sp->name) { |
| 1071 | cur = sprintf(buf, "%3d: %s\n", i, sp->name); |
| 1072 | buf += cur; |
| 1073 | res += cur; |
| 1074 | } |
| 1075 | } |
| 1076 | mutex_unlock(&cpuhp_state_mutex); |
| 1077 | return res; |
| 1078 | } |
| 1079 | static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL); |
| 1080 | |
| 1081 | static struct attribute *cpuhp_cpu_root_attrs[] = { |
| 1082 | &dev_attr_states.attr, |
| 1083 | NULL |
| 1084 | }; |
| 1085 | |
| 1086 | static struct attribute_group cpuhp_cpu_root_attr_group = { |
| 1087 | .attrs = cpuhp_cpu_root_attrs, |
| 1088 | .name = "hotplug", |
| 1089 | NULL |
| 1090 | }; |
| 1091 | |
| 1092 | static int __init cpuhp_sysfs_init(void) |
| 1093 | { |
| 1094 | int cpu, ret; |
| 1095 | |
| 1096 | ret = sysfs_create_group(&cpu_subsys.dev_root->kobj, |
| 1097 | &cpuhp_cpu_root_attr_group); |
| 1098 | if (ret) |
| 1099 | return ret; |
| 1100 | |
| 1101 | for_each_possible_cpu(cpu) { |
| 1102 | struct device *dev = get_cpu_device(cpu); |
| 1103 | |
| 1104 | if (!dev) |
| 1105 | continue; |
| 1106 | ret = sysfs_create_group(&dev->kobj, &cpuhp_cpu_attr_group); |
| 1107 | if (ret) |
| 1108 | return ret; |
| 1109 | } |
| 1110 | return 0; |
| 1111 | } |
| 1112 | device_initcall(cpuhp_sysfs_init); |
| 1113 | #endif |
| 1114 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1115 | /* |
| 1116 | * cpu_bit_bitmap[] is a special, "compressed" data structure that |
| 1117 | * represents all NR_CPUS bits binary values of 1<<nr. |
| 1118 | * |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1119 | * 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] | 1120 | * mask value that has a single bit set only. |
| 1121 | */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1122 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1123 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 1124 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1125 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) |
| 1126 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) |
| 1127 | #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] | 1128 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1129 | 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] | 1130 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1131 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), |
| 1132 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), |
| 1133 | #if BITS_PER_LONG > 32 |
| 1134 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), |
| 1135 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1136 | #endif |
| 1137 | }; |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1138 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1139 | |
| 1140 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; |
| 1141 | EXPORT_SYMBOL(cpu_all_bits); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1142 | |
| 1143 | #ifdef CONFIG_INIT_ALL_POSSIBLE |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1144 | struct cpumask __cpu_possible_mask __read_mostly |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1145 | = {CPU_BITS_ALL}; |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1146 | #else |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1147 | struct cpumask __cpu_possible_mask __read_mostly; |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1148 | #endif |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1149 | EXPORT_SYMBOL(__cpu_possible_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1150 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1151 | struct cpumask __cpu_online_mask __read_mostly; |
| 1152 | EXPORT_SYMBOL(__cpu_online_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1153 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1154 | struct cpumask __cpu_present_mask __read_mostly; |
| 1155 | EXPORT_SYMBOL(__cpu_present_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1156 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1157 | struct cpumask __cpu_active_mask __read_mostly; |
| 1158 | EXPORT_SYMBOL(__cpu_active_mask); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1159 | |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1160 | void init_cpu_present(const struct cpumask *src) |
| 1161 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1162 | cpumask_copy(&__cpu_present_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1163 | } |
| 1164 | |
| 1165 | void init_cpu_possible(const struct cpumask *src) |
| 1166 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1167 | cpumask_copy(&__cpu_possible_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1168 | } |
| 1169 | |
| 1170 | void init_cpu_online(const struct cpumask *src) |
| 1171 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1172 | cpumask_copy(&__cpu_online_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1173 | } |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1174 | |
| 1175 | /* |
| 1176 | * Activate the first processor. |
| 1177 | */ |
| 1178 | void __init boot_cpu_init(void) |
| 1179 | { |
| 1180 | int cpu = smp_processor_id(); |
| 1181 | |
| 1182 | /* Mark the boot cpu "present", "online" etc for SMP and UP case */ |
| 1183 | set_cpu_online(cpu, true); |
| 1184 | set_cpu_active(cpu, true); |
| 1185 | set_cpu_present(cpu, true); |
| 1186 | set_cpu_possible(cpu, true); |
| 1187 | } |
| 1188 | |
| 1189 | /* |
| 1190 | * Must be called _AFTER_ setting up the per_cpu areas |
| 1191 | */ |
| 1192 | void __init boot_cpu_state_init(void) |
| 1193 | { |
| 1194 | per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE; |
| 1195 | } |