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 |
| 39 | * @cb_stat: The state for a single callback (install/uninstall) |
| 40 | * @cb: Single callback function (install/uninstall) |
| 41 | * @result: Result of the operation |
| 42 | * @done: Signal completion to the issuer of the task |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 43 | */ |
| 44 | struct cpuhp_cpu_state { |
| 45 | enum cpuhp_state state; |
| 46 | enum cpuhp_state target; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 47 | #ifdef CONFIG_SMP |
| 48 | struct task_struct *thread; |
| 49 | bool should_run; |
| 50 | enum cpuhp_state cb_state; |
| 51 | int (*cb)(unsigned int cpu); |
| 52 | int result; |
| 53 | struct completion done; |
| 54 | #endif |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 55 | }; |
| 56 | |
| 57 | static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state); |
| 58 | |
| 59 | /** |
| 60 | * cpuhp_step - Hotplug state machine step |
| 61 | * @name: Name of the step |
| 62 | * @startup: Startup function of the step |
| 63 | * @teardown: Teardown function of the step |
| 64 | * @skip_onerr: Do not invoke the functions on error rollback |
| 65 | * Will go away once the notifiers are gone |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 66 | * @cant_stop: Bringup/teardown can't be stopped at this step |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 67 | */ |
| 68 | struct cpuhp_step { |
| 69 | const char *name; |
| 70 | int (*startup)(unsigned int cpu); |
| 71 | int (*teardown)(unsigned int cpu); |
| 72 | bool skip_onerr; |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 73 | bool cant_stop; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 74 | }; |
| 75 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 76 | static DEFINE_MUTEX(cpuhp_state_mutex); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 77 | static struct cpuhp_step cpuhp_bp_states[]; |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 78 | static struct cpuhp_step cpuhp_ap_states[]; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 79 | |
| 80 | /** |
| 81 | * cpuhp_invoke_callback _ Invoke the callbacks for a given state |
| 82 | * @cpu: The cpu for which the callback should be invoked |
| 83 | * @step: The step in the state machine |
| 84 | * @cb: The callback function to invoke |
| 85 | * |
| 86 | * Called from cpu hotplug and from the state register machinery |
| 87 | */ |
| 88 | static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state step, |
| 89 | int (*cb)(unsigned int)) |
| 90 | { |
| 91 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 92 | int ret = 0; |
| 93 | |
| 94 | if (cb) { |
| 95 | trace_cpuhp_enter(cpu, st->target, step, cb); |
| 96 | ret = cb(cpu); |
| 97 | trace_cpuhp_exit(cpu, st->state, step, ret); |
| 98 | } |
| 99 | return ret; |
| 100 | } |
| 101 | |
Rusty Russell | 98a79d6 | 2008-12-13 21:19:41 +1030 | [diff] [blame] | 102 | #ifdef CONFIG_SMP |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 103 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 104 | static DEFINE_MUTEX(cpu_add_remove_lock); |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 105 | bool cpuhp_tasks_frozen; |
| 106 | EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 108 | /* |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 109 | * The following two APIs (cpu_maps_update_begin/done) must be used when |
| 110 | * attempting to serialize the updates to cpu_online_mask & cpu_present_mask. |
| 111 | * The APIs cpu_notifier_register_begin/done() must be used to protect CPU |
| 112 | * hotplug callback (un)registration performed using __register_cpu_notifier() |
| 113 | * or __unregister_cpu_notifier(). |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 114 | */ |
| 115 | void cpu_maps_update_begin(void) |
| 116 | { |
| 117 | mutex_lock(&cpu_add_remove_lock); |
| 118 | } |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 119 | EXPORT_SYMBOL(cpu_notifier_register_begin); |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 120 | |
| 121 | void cpu_maps_update_done(void) |
| 122 | { |
| 123 | mutex_unlock(&cpu_add_remove_lock); |
| 124 | } |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 125 | EXPORT_SYMBOL(cpu_notifier_register_done); |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 126 | |
Daniel J Blueman | 5c113fb | 2010-06-01 12:15:11 +0100 | [diff] [blame] | 127 | static RAW_NOTIFIER_HEAD(cpu_chain); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 129 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
| 130 | * Should always be manipulated under cpu_add_remove_lock |
| 131 | */ |
| 132 | static int cpu_hotplug_disabled; |
| 133 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 134 | #ifdef CONFIG_HOTPLUG_CPU |
| 135 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 136 | static struct { |
| 137 | struct task_struct *active_writer; |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 138 | /* wait queue to wake up the active_writer */ |
| 139 | wait_queue_head_t wq; |
| 140 | /* verifies that no writer will get active while readers are active */ |
| 141 | struct mutex lock; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 142 | /* |
| 143 | * Also blocks the new readers during |
| 144 | * an ongoing cpu hotplug operation. |
| 145 | */ |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 146 | atomic_t refcount; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 147 | |
| 148 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| 149 | struct lockdep_map dep_map; |
| 150 | #endif |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 151 | } cpu_hotplug = { |
| 152 | .active_writer = NULL, |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 153 | .wq = __WAIT_QUEUE_HEAD_INITIALIZER(cpu_hotplug.wq), |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 154 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 155 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| 156 | .dep_map = {.name = "cpu_hotplug.lock" }, |
| 157 | #endif |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 158 | }; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 159 | |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 160 | /* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */ |
| 161 | #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] | 162 | #define cpuhp_lock_acquire_tryread() \ |
| 163 | lock_map_acquire_tryread(&cpu_hotplug.dep_map) |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 164 | #define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map) |
| 165 | #define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map) |
| 166 | |
Paul E. McKenney | 62db99f | 2014-10-22 14:51:49 -0700 | [diff] [blame] | 167 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 168 | void get_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 169 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 170 | might_sleep(); |
| 171 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 172 | return; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 173 | cpuhp_lock_acquire_read(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 174 | mutex_lock(&cpu_hotplug.lock); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 175 | atomic_inc(&cpu_hotplug.refcount); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 176 | mutex_unlock(&cpu_hotplug.lock); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 177 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 178 | EXPORT_SYMBOL_GPL(get_online_cpus); |
Ashok Raj | 90d45d1 | 2005-11-08 21:34:24 -0800 | [diff] [blame] | 179 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 180 | void put_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 181 | { |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 182 | int refcount; |
| 183 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 184 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 185 | return; |
Srivatsa S. Bhat | 075663d | 2012-10-08 16:28:20 -0700 | [diff] [blame] | 186 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 187 | refcount = atomic_dec_return(&cpu_hotplug.refcount); |
| 188 | if (WARN_ON(refcount < 0)) /* try to fix things up */ |
| 189 | atomic_inc(&cpu_hotplug.refcount); |
Srivatsa S. Bhat | 075663d | 2012-10-08 16:28:20 -0700 | [diff] [blame] | 190 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 191 | if (refcount <= 0 && waitqueue_active(&cpu_hotplug.wq)) |
| 192 | wake_up(&cpu_hotplug.wq); |
| 193 | |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 194 | cpuhp_lock_release(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 195 | |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 196 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 197 | EXPORT_SYMBOL_GPL(put_online_cpus); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 198 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 199 | /* |
| 200 | * This ensures that the hotplug operation can begin only when the |
| 201 | * refcount goes to zero. |
| 202 | * |
| 203 | * Note that during a cpu-hotplug operation, the new readers, if any, |
| 204 | * will be blocked by the cpu_hotplug.lock |
| 205 | * |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 206 | * Since cpu_hotplug_begin() is always called after invoking |
| 207 | * 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] | 208 | * |
| 209 | * Note that theoretically, there is a possibility of a livelock: |
| 210 | * - Refcount goes to zero, last reader wakes up the sleeping |
| 211 | * writer. |
| 212 | * - Last reader unlocks the cpu_hotplug.lock. |
| 213 | * - A new reader arrives at this moment, bumps up the refcount. |
| 214 | * - The writer acquires the cpu_hotplug.lock finds the refcount |
| 215 | * non zero and goes to sleep again. |
| 216 | * |
| 217 | * However, this is very difficult to achieve in practice since |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 218 | * 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] | 219 | * |
| 220 | */ |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 221 | void cpu_hotplug_begin(void) |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 222 | { |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 223 | DEFINE_WAIT(wait); |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 224 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 225 | cpu_hotplug.active_writer = current; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 226 | cpuhp_lock_acquire(); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 227 | |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 228 | for (;;) { |
| 229 | mutex_lock(&cpu_hotplug.lock); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 230 | prepare_to_wait(&cpu_hotplug.wq, &wait, TASK_UNINTERRUPTIBLE); |
| 231 | if (likely(!atomic_read(&cpu_hotplug.refcount))) |
| 232 | break; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 233 | mutex_unlock(&cpu_hotplug.lock); |
| 234 | schedule(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 235 | } |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 236 | finish_wait(&cpu_hotplug.wq, &wait); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 237 | } |
| 238 | |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 239 | void cpu_hotplug_done(void) |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 240 | { |
| 241 | cpu_hotplug.active_writer = NULL; |
| 242 | mutex_unlock(&cpu_hotplug.lock); |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 243 | cpuhp_lock_release(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 244 | } |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 245 | |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 246 | /* |
| 247 | * Wait for currently running CPU hotplug operations to complete (if any) and |
| 248 | * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects |
| 249 | * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the |
| 250 | * hotplug path before performing hotplug operations. So acquiring that lock |
| 251 | * guarantees mutual exclusion from any currently running hotplug operations. |
| 252 | */ |
| 253 | void cpu_hotplug_disable(void) |
| 254 | { |
| 255 | cpu_maps_update_begin(); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 256 | cpu_hotplug_disabled++; |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 257 | cpu_maps_update_done(); |
| 258 | } |
Vitaly Kuznetsov | 32145c4 | 2015-08-05 00:52:47 -0700 | [diff] [blame] | 259 | EXPORT_SYMBOL_GPL(cpu_hotplug_disable); |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 260 | |
| 261 | void cpu_hotplug_enable(void) |
| 262 | { |
| 263 | cpu_maps_update_begin(); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 264 | WARN_ON(--cpu_hotplug_disabled < 0); |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 265 | cpu_maps_update_done(); |
| 266 | } |
Vitaly Kuznetsov | 32145c4 | 2015-08-05 00:52:47 -0700 | [diff] [blame] | 267 | EXPORT_SYMBOL_GPL(cpu_hotplug_enable); |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 268 | #endif /* CONFIG_HOTPLUG_CPU */ |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 269 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | /* Need to know about CPUs going up/down? */ |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 271 | int register_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | { |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 273 | int ret; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 274 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 275 | ret = raw_notifier_chain_register(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 276 | cpu_maps_update_done(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 277 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 278 | } |
Chandra Seetharaman | 65edc68 | 2006-06-27 02:54:08 -0700 | [diff] [blame] | 279 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 280 | int __register_cpu_notifier(struct notifier_block *nb) |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 281 | { |
| 282 | return raw_notifier_chain_register(&cpu_chain, nb); |
| 283 | } |
| 284 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 285 | 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] | 286 | int *nr_calls) |
| 287 | { |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 288 | unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0; |
| 289 | void *hcpu = (void *)(long)cpu; |
| 290 | |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 291 | int ret; |
| 292 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 293 | 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] | 294 | nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 295 | |
| 296 | return notifier_to_errno(ret); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 297 | } |
| 298 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 299 | static int cpu_notify(unsigned long val, unsigned int cpu) |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 300 | { |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 301 | return __cpu_notify(val, cpu, -1, NULL); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 302 | } |
| 303 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 304 | /* Notifier wrappers for transitioning to state machine */ |
| 305 | static int notify_prepare(unsigned int cpu) |
| 306 | { |
| 307 | int nr_calls = 0; |
| 308 | int ret; |
| 309 | |
| 310 | ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls); |
| 311 | if (ret) { |
| 312 | nr_calls--; |
| 313 | printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", |
| 314 | __func__, cpu); |
| 315 | __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL); |
| 316 | } |
| 317 | return ret; |
| 318 | } |
| 319 | |
| 320 | static int notify_online(unsigned int cpu) |
| 321 | { |
| 322 | cpu_notify(CPU_ONLINE, cpu); |
| 323 | return 0; |
| 324 | } |
| 325 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 326 | static int notify_starting(unsigned int cpu) |
| 327 | { |
| 328 | cpu_notify(CPU_STARTING, cpu); |
| 329 | return 0; |
| 330 | } |
| 331 | |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame^] | 332 | static int bringup_wait_for_ap(unsigned int cpu) |
| 333 | { |
| 334 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 335 | |
| 336 | wait_for_completion(&st->done); |
| 337 | return st->result; |
| 338 | } |
| 339 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 340 | static int bringup_cpu(unsigned int cpu) |
| 341 | { |
| 342 | struct task_struct *idle = idle_thread_get(cpu); |
| 343 | int ret; |
| 344 | |
| 345 | /* Arch-specific enabling code. */ |
| 346 | ret = __cpu_up(cpu, idle); |
| 347 | if (ret) { |
| 348 | cpu_notify(CPU_UP_CANCELED, cpu); |
| 349 | return ret; |
| 350 | } |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame^] | 351 | ret = bringup_wait_for_ap(cpu); |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 352 | BUG_ON(!cpu_online(cpu)); |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame^] | 353 | return ret; |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 354 | } |
| 355 | |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 356 | /* |
| 357 | * Hotplug state machine related functions |
| 358 | */ |
| 359 | static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st, |
| 360 | struct cpuhp_step *steps) |
| 361 | { |
| 362 | for (st->state++; st->state < st->target; st->state++) { |
| 363 | struct cpuhp_step *step = steps + st->state; |
| 364 | |
| 365 | if (!step->skip_onerr) |
| 366 | cpuhp_invoke_callback(cpu, st->state, step->startup); |
| 367 | } |
| 368 | } |
| 369 | |
| 370 | static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, |
| 371 | struct cpuhp_step *steps, enum cpuhp_state target) |
| 372 | { |
| 373 | enum cpuhp_state prev_state = st->state; |
| 374 | int ret = 0; |
| 375 | |
| 376 | for (; st->state > target; st->state--) { |
| 377 | struct cpuhp_step *step = steps + st->state; |
| 378 | |
| 379 | ret = cpuhp_invoke_callback(cpu, st->state, step->teardown); |
| 380 | if (ret) { |
| 381 | st->target = prev_state; |
| 382 | undo_cpu_down(cpu, st, steps); |
| 383 | break; |
| 384 | } |
| 385 | } |
| 386 | return ret; |
| 387 | } |
| 388 | |
| 389 | static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st, |
| 390 | struct cpuhp_step *steps) |
| 391 | { |
| 392 | for (st->state--; st->state > st->target; st->state--) { |
| 393 | struct cpuhp_step *step = steps + st->state; |
| 394 | |
| 395 | if (!step->skip_onerr) |
| 396 | cpuhp_invoke_callback(cpu, st->state, step->teardown); |
| 397 | } |
| 398 | } |
| 399 | |
| 400 | static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, |
| 401 | struct cpuhp_step *steps, enum cpuhp_state target) |
| 402 | { |
| 403 | enum cpuhp_state prev_state = st->state; |
| 404 | int ret = 0; |
| 405 | |
| 406 | while (st->state < target) { |
| 407 | struct cpuhp_step *step; |
| 408 | |
| 409 | st->state++; |
| 410 | step = steps + st->state; |
| 411 | ret = cpuhp_invoke_callback(cpu, st->state, step->startup); |
| 412 | if (ret) { |
| 413 | st->target = prev_state; |
| 414 | undo_cpu_up(cpu, st, steps); |
| 415 | break; |
| 416 | } |
| 417 | } |
| 418 | return ret; |
| 419 | } |
| 420 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 421 | /* |
| 422 | * The cpu hotplug threads manage the bringup and teardown of the cpus |
| 423 | */ |
| 424 | static void cpuhp_create(unsigned int cpu) |
| 425 | { |
| 426 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 427 | |
| 428 | init_completion(&st->done); |
| 429 | } |
| 430 | |
| 431 | static int cpuhp_should_run(unsigned int cpu) |
| 432 | { |
| 433 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 434 | |
| 435 | return st->should_run; |
| 436 | } |
| 437 | |
| 438 | /* Execute the teardown callbacks. Used to be CPU_DOWN_PREPARE */ |
| 439 | static int cpuhp_ap_offline(unsigned int cpu, struct cpuhp_cpu_state *st) |
| 440 | { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 441 | enum cpuhp_state target = max((int)st->target, CPUHP_TEARDOWN_CPU); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 442 | |
| 443 | return cpuhp_down_callbacks(cpu, st, cpuhp_ap_states, target); |
| 444 | } |
| 445 | |
| 446 | /* Execute the online startup callbacks. Used to be CPU_ONLINE */ |
| 447 | static int cpuhp_ap_online(unsigned int cpu, struct cpuhp_cpu_state *st) |
| 448 | { |
| 449 | return cpuhp_up_callbacks(cpu, st, cpuhp_ap_states, st->target); |
| 450 | } |
| 451 | |
| 452 | /* |
| 453 | * Execute teardown/startup callbacks on the plugged cpu. Also used to invoke |
| 454 | * callbacks when a state gets [un]installed at runtime. |
| 455 | */ |
| 456 | static void cpuhp_thread_fun(unsigned int cpu) |
| 457 | { |
| 458 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 459 | int ret = 0; |
| 460 | |
| 461 | /* |
| 462 | * Paired with the mb() in cpuhp_kick_ap_work and |
| 463 | * cpuhp_invoke_ap_callback, so the work set is consistent visible. |
| 464 | */ |
| 465 | smp_mb(); |
| 466 | if (!st->should_run) |
| 467 | return; |
| 468 | |
| 469 | st->should_run = false; |
| 470 | |
| 471 | /* Single callback invocation for [un]install ? */ |
| 472 | if (st->cb) { |
| 473 | if (st->cb_state < CPUHP_AP_ONLINE) { |
| 474 | local_irq_disable(); |
| 475 | ret = cpuhp_invoke_callback(cpu, st->cb_state, st->cb); |
| 476 | local_irq_enable(); |
| 477 | } else { |
| 478 | ret = cpuhp_invoke_callback(cpu, st->cb_state, st->cb); |
| 479 | } |
| 480 | } else { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 481 | /* Cannot happen .... */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame^] | 482 | BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 483 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 484 | /* Regular hotplug work */ |
| 485 | if (st->state < st->target) |
| 486 | ret = cpuhp_ap_online(cpu, st); |
| 487 | else if (st->state > st->target) |
| 488 | ret = cpuhp_ap_offline(cpu, st); |
| 489 | } |
| 490 | st->result = ret; |
| 491 | complete(&st->done); |
| 492 | } |
| 493 | |
| 494 | /* Invoke a single callback on a remote cpu */ |
| 495 | static int cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state, |
| 496 | int (*cb)(unsigned int)) |
| 497 | { |
| 498 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 499 | |
| 500 | if (!cpu_online(cpu)) |
| 501 | return 0; |
| 502 | |
| 503 | st->cb_state = state; |
| 504 | st->cb = cb; |
| 505 | /* |
| 506 | * Make sure the above stores are visible before should_run becomes |
| 507 | * true. Paired with the mb() above in cpuhp_thread_fun() |
| 508 | */ |
| 509 | smp_mb(); |
| 510 | st->should_run = true; |
| 511 | wake_up_process(st->thread); |
| 512 | wait_for_completion(&st->done); |
| 513 | return st->result; |
| 514 | } |
| 515 | |
| 516 | /* Regular hotplug invocation of the AP hotplug thread */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 517 | static void __cpuhp_kick_ap_work(struct cpuhp_cpu_state *st) |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 518 | { |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 519 | st->result = 0; |
| 520 | st->cb = NULL; |
| 521 | /* |
| 522 | * Make sure the above stores are visible before should_run becomes |
| 523 | * true. Paired with the mb() above in cpuhp_thread_fun() |
| 524 | */ |
| 525 | smp_mb(); |
| 526 | st->should_run = true; |
| 527 | wake_up_process(st->thread); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 528 | } |
| 529 | |
| 530 | static int cpuhp_kick_ap_work(unsigned int cpu) |
| 531 | { |
| 532 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 533 | enum cpuhp_state state = st->state; |
| 534 | |
| 535 | trace_cpuhp_enter(cpu, st->target, state, cpuhp_kick_ap_work); |
| 536 | __cpuhp_kick_ap_work(st); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 537 | wait_for_completion(&st->done); |
| 538 | trace_cpuhp_exit(cpu, st->state, state, st->result); |
| 539 | return st->result; |
| 540 | } |
| 541 | |
| 542 | static struct smp_hotplug_thread cpuhp_threads = { |
| 543 | .store = &cpuhp_state.thread, |
| 544 | .create = &cpuhp_create, |
| 545 | .thread_should_run = cpuhp_should_run, |
| 546 | .thread_fn = cpuhp_thread_fun, |
| 547 | .thread_comm = "cpuhp/%u", |
| 548 | .selfparking = true, |
| 549 | }; |
| 550 | |
| 551 | void __init cpuhp_threads_init(void) |
| 552 | { |
| 553 | BUG_ON(smpboot_register_percpu_thread(&cpuhp_threads)); |
| 554 | kthread_unpark(this_cpu_read(cpuhp_state.thread)); |
| 555 | } |
| 556 | |
Linus Torvalds | 00b9b0a | 2010-05-27 10:32:08 -0700 | [diff] [blame] | 557 | #ifdef CONFIG_HOTPLUG_CPU |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | EXPORT_SYMBOL(register_cpu_notifier); |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 559 | EXPORT_SYMBOL(__register_cpu_notifier); |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 560 | void unregister_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 561 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 562 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 563 | raw_notifier_chain_unregister(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 564 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | } |
| 566 | EXPORT_SYMBOL(unregister_cpu_notifier); |
| 567 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 568 | void __unregister_cpu_notifier(struct notifier_block *nb) |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 569 | { |
| 570 | raw_notifier_chain_unregister(&cpu_chain, nb); |
| 571 | } |
| 572 | EXPORT_SYMBOL(__unregister_cpu_notifier); |
| 573 | |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 574 | /** |
| 575 | * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU |
| 576 | * @cpu: a CPU id |
| 577 | * |
| 578 | * This function walks all processes, finds a valid mm struct for each one and |
| 579 | * then clears a corresponding bit in mm's cpumask. While this all sounds |
| 580 | * trivial, there are various non-obvious corner cases, which this function |
| 581 | * tries to solve in a safe manner. |
| 582 | * |
| 583 | * Also note that the function uses a somewhat relaxed locking scheme, so it may |
| 584 | * be called only for an already offlined CPU. |
| 585 | */ |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 586 | void clear_tasks_mm_cpumask(int cpu) |
| 587 | { |
| 588 | struct task_struct *p; |
| 589 | |
| 590 | /* |
| 591 | * This function is called after the cpu is taken down and marked |
| 592 | * offline, so its not like new tasks will ever get this cpu set in |
| 593 | * their mm mask. -- Peter Zijlstra |
| 594 | * Thus, we may use rcu_read_lock() here, instead of grabbing |
| 595 | * full-fledged tasklist_lock. |
| 596 | */ |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 597 | WARN_ON(cpu_online(cpu)); |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 598 | rcu_read_lock(); |
| 599 | for_each_process(p) { |
| 600 | struct task_struct *t; |
| 601 | |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 602 | /* |
| 603 | * Main thread might exit, but other threads may still have |
| 604 | * a valid mm. Find one. |
| 605 | */ |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 606 | t = find_lock_task_mm(p); |
| 607 | if (!t) |
| 608 | continue; |
| 609 | cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); |
| 610 | task_unlock(t); |
| 611 | } |
| 612 | rcu_read_unlock(); |
| 613 | } |
| 614 | |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 615 | static inline void check_for_tasks(int dead_cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 616 | { |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 617 | struct task_struct *g, *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 618 | |
Oleg Nesterov | a75a606 | 2015-09-10 15:07:50 +0200 | [diff] [blame] | 619 | read_lock(&tasklist_lock); |
| 620 | for_each_process_thread(g, p) { |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 621 | if (!p->on_rq) |
| 622 | continue; |
| 623 | /* |
| 624 | * We do the check with unlocked task_rq(p)->lock. |
| 625 | * Order the reading to do not warn about a task, |
| 626 | * which was running on this cpu in the past, and |
| 627 | * it's just been woken on another cpu. |
| 628 | */ |
| 629 | rmb(); |
| 630 | if (task_cpu(p) != dead_cpu) |
| 631 | continue; |
| 632 | |
| 633 | pr_warn("Task %s (pid=%d) is on cpu %d (state=%ld, flags=%x)\n", |
| 634 | p->comm, task_pid_nr(p), dead_cpu, p->state, p->flags); |
Oleg Nesterov | a75a606 | 2015-09-10 15:07:50 +0200 | [diff] [blame] | 635 | } |
| 636 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 637 | } |
| 638 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 639 | static void cpu_notify_nofail(unsigned long val, unsigned int cpu) |
| 640 | { |
| 641 | BUG_ON(cpu_notify(val, cpu)); |
| 642 | } |
| 643 | |
| 644 | static int notify_down_prepare(unsigned int cpu) |
| 645 | { |
| 646 | int err, nr_calls = 0; |
| 647 | |
| 648 | err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls); |
| 649 | if (err) { |
| 650 | nr_calls--; |
| 651 | __cpu_notify(CPU_DOWN_FAILED, cpu, nr_calls, NULL); |
| 652 | pr_warn("%s: attempt to take down CPU %u failed\n", |
| 653 | __func__, cpu); |
| 654 | } |
| 655 | return err; |
| 656 | } |
| 657 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 658 | static int notify_dying(unsigned int cpu) |
| 659 | { |
| 660 | cpu_notify(CPU_DYING, cpu); |
| 661 | return 0; |
| 662 | } |
| 663 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 664 | /* Take this CPU down. */ |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 665 | static int take_cpu_down(void *_param) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | { |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 667 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 668 | enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE); |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 669 | int err, cpu = smp_processor_id(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 670 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | /* Ensure this CPU doesn't handle any more interrupts. */ |
| 672 | err = __cpu_disable(); |
| 673 | if (err < 0) |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 674 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 676 | /* Invoke the former CPU_DYING callbacks */ |
| 677 | for (; st->state > target; st->state--) { |
| 678 | struct cpuhp_step *step = cpuhp_ap_states + st->state; |
| 679 | |
| 680 | cpuhp_invoke_callback(cpu, st->state, step->teardown); |
| 681 | } |
Thomas Gleixner | 52c063d | 2015-04-03 02:37:24 +0200 | [diff] [blame] | 682 | /* Give up timekeeping duties */ |
| 683 | tick_handover_do_timer(); |
Thomas Gleixner | 14e568e | 2013-01-31 12:11:14 +0000 | [diff] [blame] | 684 | /* Park the stopper thread */ |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 685 | stop_machine_park(cpu); |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 686 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | } |
| 688 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 689 | static int takedown_cpu(unsigned int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 690 | { |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 691 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 692 | |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 693 | /* |
| 694 | * By now we've cleared cpu_active_mask, wait for all preempt-disabled |
| 695 | * and RCU users of this state to go away such that all new such users |
| 696 | * will observe it. |
| 697 | * |
| 698 | * 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] | 699 | * not imply sync_sched(), so wait for both. |
Michael wang | 106dd5a | 2013-11-13 11:10:56 +0800 | [diff] [blame] | 700 | * |
| 701 | * 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] | 702 | */ |
Paul E. McKenney | 779de6c | 2015-06-10 13:34:41 -0700 | [diff] [blame] | 703 | if (IS_ENABLED(CONFIG_PREEMPT)) |
| 704 | synchronize_rcu_mult(call_rcu, call_rcu_sched); |
| 705 | else |
| 706 | synchronize_rcu(); |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 707 | |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 708 | /* Park the hotplug thread */ |
| 709 | kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread); |
| 710 | |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 711 | /* |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 712 | * Prevent irq alloc/free while the dying cpu reorganizes the |
| 713 | * interrupt affinities. |
| 714 | */ |
| 715 | irq_lock_sparse(); |
| 716 | |
| 717 | /* |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 718 | * So now all preempt/rcu users must observe !cpu_active(). |
| 719 | */ |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 720 | err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu)); |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 721 | if (err) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 722 | /* CPU didn't die: tell everyone. Can't complain. */ |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 723 | cpu_notify_nofail(CPU_DOWN_FAILED, cpu); |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 724 | irq_unlock_sparse(); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 725 | return err; |
Satoru Takeuchi | 8fa1d7d | 2006-10-28 10:38:57 -0700 | [diff] [blame] | 726 | } |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 727 | BUG_ON(cpu_online(cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 728 | |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 729 | /* |
| 730 | * The migration_call() CPU_DYING callback will have removed all |
| 731 | * runnable tasks from the cpu, there's only the idle task left now |
| 732 | * that the migration thread is done doing the stop_machine thing. |
Peter Zijlstra | 51a96c7 | 2010-11-19 20:37:53 +0100 | [diff] [blame] | 733 | * |
| 734 | * Wait for the stop thread to go away. |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 735 | */ |
Paul E. McKenney | 528a25b | 2015-01-28 14:09:43 -0800 | [diff] [blame] | 736 | while (!per_cpu(cpu_dead_idle, cpu)) |
Peter Zijlstra | 51a96c7 | 2010-11-19 20:37:53 +0100 | [diff] [blame] | 737 | cpu_relax(); |
Paul E. McKenney | 528a25b | 2015-01-28 14:09:43 -0800 | [diff] [blame] | 738 | smp_mb(); /* Read from cpu_dead_idle before __cpu_die(). */ |
| 739 | per_cpu(cpu_dead_idle, cpu) = false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 741 | /* Interrupts are moved away from the dying cpu, reenable alloc/free */ |
| 742 | irq_unlock_sparse(); |
| 743 | |
Preeti U Murthy | 345527b | 2015-03-30 14:59:19 +0530 | [diff] [blame] | 744 | hotplug_cpu__broadcast_tick_pull(cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 745 | /* This actually kills the CPU. */ |
| 746 | __cpu_die(cpu); |
| 747 | |
Thomas Gleixner | a49b116 | 2015-04-03 02:38:05 +0200 | [diff] [blame] | 748 | tick_cleanup_dead_cpu(cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 749 | return 0; |
| 750 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 751 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 752 | static int notify_dead(unsigned int cpu) |
| 753 | { |
| 754 | cpu_notify_nofail(CPU_DEAD, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 755 | check_for_tasks(cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 756 | return 0; |
| 757 | } |
| 758 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 759 | #else |
| 760 | #define notify_down_prepare NULL |
| 761 | #define takedown_cpu NULL |
| 762 | #define notify_dead NULL |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 763 | #define notify_dying NULL |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 764 | #endif |
| 765 | |
| 766 | #ifdef CONFIG_HOTPLUG_CPU |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 767 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 768 | /* Requires cpu_add_remove_lock to be held */ |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 769 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, |
| 770 | enum cpuhp_state target) |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 771 | { |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 772 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 773 | int prev_state, ret = 0; |
| 774 | bool hasdied = false; |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 775 | |
| 776 | if (num_online_cpus() == 1) |
| 777 | return -EBUSY; |
| 778 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 779 | if (!cpu_present(cpu)) |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 780 | return -EINVAL; |
| 781 | |
| 782 | cpu_hotplug_begin(); |
| 783 | |
| 784 | cpuhp_tasks_frozen = tasks_frozen; |
| 785 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 786 | prev_state = st->state; |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 787 | st->target = target; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 788 | /* |
| 789 | * If the current CPU state is in the range of the AP hotplug thread, |
| 790 | * then we need to kick the thread. |
| 791 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame^] | 792 | if (st->state > CPUHP_TEARDOWN_CPU) { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 793 | ret = cpuhp_kick_ap_work(cpu); |
| 794 | /* |
| 795 | * The AP side has done the error rollback already. Just |
| 796 | * return the error code.. |
| 797 | */ |
| 798 | if (ret) |
| 799 | goto out; |
| 800 | |
| 801 | /* |
| 802 | * We might have stopped still in the range of the AP hotplug |
| 803 | * thread. Nothing to do anymore. |
| 804 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame^] | 805 | if (st->state > CPUHP_TEARDOWN_CPU) |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 806 | goto out; |
| 807 | } |
| 808 | /* |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame^] | 809 | * The AP brought itself down to CPUHP_TEARDOWN_CPU. So we need |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 810 | * to do the further cleanups. |
| 811 | */ |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 812 | ret = cpuhp_down_callbacks(cpu, st, cpuhp_bp_states, target); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 813 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 814 | hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 815 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 816 | cpu_hotplug_done(); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 817 | /* This post dead nonsense must die */ |
| 818 | if (!ret && hasdied) |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 819 | cpu_notify_nofail(CPU_POST_DEAD, cpu); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 820 | return ret; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 821 | } |
| 822 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 823 | 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] | 824 | { |
Heiko Carstens | 9ea09af | 2008-12-22 12:36:30 +0100 | [diff] [blame] | 825 | int err; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 826 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 827 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 828 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 829 | if (cpu_hotplug_disabled) { |
| 830 | err = -EBUSY; |
| 831 | goto out; |
| 832 | } |
| 833 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 834 | err = _cpu_down(cpu, 0, target); |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 835 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 836 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 837 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 838 | return err; |
| 839 | } |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 840 | int cpu_down(unsigned int cpu) |
| 841 | { |
| 842 | return do_cpu_down(cpu, CPUHP_OFFLINE); |
| 843 | } |
Zhang Rui | b62b8ef | 2008-04-29 02:35:56 -0400 | [diff] [blame] | 844 | EXPORT_SYMBOL(cpu_down); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 845 | #endif /*CONFIG_HOTPLUG_CPU*/ |
| 846 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 847 | /** |
| 848 | * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers |
| 849 | * @cpu: cpu that just started |
| 850 | * |
| 851 | * This function calls the cpu_chain notifiers with CPU_STARTING. |
| 852 | * It must be called by the arch code on the new cpu, before the new cpu |
| 853 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). |
| 854 | */ |
| 855 | void notify_cpu_starting(unsigned int cpu) |
| 856 | { |
| 857 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 858 | enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE); |
| 859 | |
| 860 | while (st->state < target) { |
| 861 | struct cpuhp_step *step; |
| 862 | |
| 863 | st->state++; |
| 864 | step = cpuhp_ap_states + st->state; |
| 865 | cpuhp_invoke_callback(cpu, st->state, step->startup); |
| 866 | } |
| 867 | } |
| 868 | |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 869 | /* |
| 870 | * 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^] | 871 | * the stopper thread and unpark the smpboot threads. If the target state is |
| 872 | * beyond CPUHP_AP_ONLINE_IDLE we kick cpuhp thread and let it bring up the |
| 873 | * cpu further. |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 874 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame^] | 875 | void cpuhp_online_idle(enum cpuhp_state state) |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 876 | { |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame^] | 877 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 878 | unsigned int cpu = smp_processor_id(); |
| 879 | |
| 880 | /* Happens for the boot cpu */ |
| 881 | if (state != CPUHP_AP_ONLINE_IDLE) |
| 882 | return; |
| 883 | |
| 884 | st->state = CPUHP_AP_ONLINE_IDLE; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 885 | |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 886 | /* The cpu is marked online, set it active now */ |
| 887 | set_cpu_active(cpu, true); |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame^] | 888 | /* Unpark the stopper thread and the hotplug thread of this cpu */ |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 889 | stop_machine_unpark(cpu); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 890 | kthread_unpark(st->thread); |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame^] | 891 | |
| 892 | /* Should we go further up ? */ |
| 893 | if (st->target > CPUHP_AP_ONLINE_IDLE) |
| 894 | __cpuhp_kick_ap_work(st); |
| 895 | else |
| 896 | complete(&st->done); |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 897 | } |
| 898 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 899 | /* Requires cpu_add_remove_lock to be held */ |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 900 | 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] | 901 | { |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 902 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 903 | struct task_struct *idle; |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 904 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 905 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 906 | cpu_hotplug_begin(); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 907 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 908 | if (!cpu_present(cpu)) { |
Yasuaki Ishimatsu | 5e5041f | 2012-10-23 01:30:54 +0200 | [diff] [blame] | 909 | ret = -EINVAL; |
| 910 | goto out; |
| 911 | } |
| 912 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 913 | /* |
| 914 | * The caller of do_cpu_up might have raced with another |
| 915 | * caller. Ignore it for now. |
| 916 | */ |
| 917 | if (st->state >= target) |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 918 | goto out; |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 919 | |
| 920 | if (st->state == CPUHP_OFFLINE) { |
| 921 | /* Let it fail before we try to bring the cpu up */ |
| 922 | idle = idle_thread_get(cpu); |
| 923 | if (IS_ERR(idle)) { |
| 924 | ret = PTR_ERR(idle); |
| 925 | goto out; |
| 926 | } |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 927 | } |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 928 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 929 | cpuhp_tasks_frozen = tasks_frozen; |
| 930 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 931 | st->target = target; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 932 | /* |
| 933 | * If the current CPU state is in the range of the AP hotplug thread, |
| 934 | * then we need to kick the thread once more. |
| 935 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame^] | 936 | if (st->state > CPUHP_BRINGUP_CPU) { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 937 | ret = cpuhp_kick_ap_work(cpu); |
| 938 | /* |
| 939 | * The AP side has done the error rollback already. Just |
| 940 | * return the error code.. |
| 941 | */ |
| 942 | if (ret) |
| 943 | goto out; |
| 944 | } |
| 945 | |
| 946 | /* |
| 947 | * 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^] | 948 | * CPUHP_BRINGUP_CPU. After that the AP hotplug thread is |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 949 | * responsible for bringing it up to the target state. |
| 950 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame^] | 951 | target = min((int)target, CPUHP_BRINGUP_CPU); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 952 | ret = cpuhp_up_callbacks(cpu, st, cpuhp_bp_states, target); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 953 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 954 | cpu_hotplug_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 955 | return ret; |
| 956 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 957 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 958 | 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] | 959 | { |
| 960 | int err = 0; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 961 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 962 | if (!cpu_possible(cpu)) { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 963 | pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n", |
| 964 | cpu); |
Chen Gong | 87d5e02 | 2010-03-05 13:42:38 -0800 | [diff] [blame] | 965 | #if defined(CONFIG_IA64) |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 966 | pr_err("please check additional_cpus= boot parameter\n"); |
KAMEZAWA Hiroyuki | 73e753a | 2007-10-18 23:40:47 -0700 | [diff] [blame] | 967 | #endif |
| 968 | return -EINVAL; |
| 969 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 970 | |
Toshi Kani | 01b0f19 | 2013-11-12 15:07:25 -0800 | [diff] [blame] | 971 | err = try_online_node(cpu_to_node(cpu)); |
| 972 | if (err) |
| 973 | return err; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 974 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 975 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 976 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 977 | if (cpu_hotplug_disabled) { |
| 978 | err = -EBUSY; |
| 979 | goto out; |
| 980 | } |
| 981 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 982 | err = _cpu_up(cpu, 0, target); |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 983 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 984 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 985 | return err; |
| 986 | } |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 987 | |
| 988 | int cpu_up(unsigned int cpu) |
| 989 | { |
| 990 | return do_cpu_up(cpu, CPUHP_ONLINE); |
| 991 | } |
Paul E. McKenney | a513f6b | 2011-12-11 21:54:45 -0800 | [diff] [blame] | 992 | EXPORT_SYMBOL_GPL(cpu_up); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 993 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 994 | #ifdef CONFIG_PM_SLEEP_SMP |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 995 | static cpumask_var_t frozen_cpus; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 996 | |
| 997 | int disable_nonboot_cpus(void) |
| 998 | { |
Rafael J. Wysocki | e9a5f42 | 2010-05-27 22:16:22 +0200 | [diff] [blame] | 999 | int cpu, first_cpu, error = 0; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1000 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1001 | cpu_maps_update_begin(); |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1002 | first_cpu = cpumask_first(cpu_online_mask); |
Xiaotian Feng | 9ee349a | 2009-12-16 18:04:32 +0100 | [diff] [blame] | 1003 | /* |
| 1004 | * 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] | 1005 | * with the userspace trying to use the CPU hotplug at the same time |
| 1006 | */ |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1007 | cpumask_clear(frozen_cpus); |
Peter Zijlstra | 6ad4c18 | 2009-11-25 13:31:39 +0100 | [diff] [blame] | 1008 | |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1009 | pr_info("Disabling non-boot CPUs ...\n"); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1010 | for_each_online_cpu(cpu) { |
| 1011 | if (cpu == first_cpu) |
| 1012 | continue; |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1013 | trace_suspend_resume(TPS("CPU_OFF"), cpu, true); |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1014 | error = _cpu_down(cpu, 1, CPUHP_OFFLINE); |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1015 | trace_suspend_resume(TPS("CPU_OFF"), cpu, false); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 1016 | if (!error) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1017 | cpumask_set_cpu(cpu, frozen_cpus); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 1018 | else { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1019 | pr_err("Error taking CPU%d down: %d\n", cpu, error); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1020 | break; |
| 1021 | } |
| 1022 | } |
Joseph Cihula | 86886e5 | 2009-06-30 19:31:07 -0700 | [diff] [blame] | 1023 | |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1024 | if (!error) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1025 | BUG_ON(num_online_cpus() > 1); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1026 | else |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1027 | pr_err("Non-boot CPUs are not disabled\n"); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1028 | |
| 1029 | /* |
| 1030 | * Make sure the CPUs won't be enabled by someone else. We need to do |
| 1031 | * this even in case of failure as all disable_nonboot_cpus() users are |
| 1032 | * supposed to do enable_nonboot_cpus() on the failure path. |
| 1033 | */ |
| 1034 | cpu_hotplug_disabled++; |
| 1035 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1036 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1037 | return error; |
| 1038 | } |
| 1039 | |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1040 | void __weak arch_enable_nonboot_cpus_begin(void) |
| 1041 | { |
| 1042 | } |
| 1043 | |
| 1044 | void __weak arch_enable_nonboot_cpus_end(void) |
| 1045 | { |
| 1046 | } |
| 1047 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 1048 | void enable_nonboot_cpus(void) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1049 | { |
| 1050 | int cpu, error; |
| 1051 | |
| 1052 | /* Allow everyone to use the CPU hotplug again */ |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1053 | cpu_maps_update_begin(); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1054 | WARN_ON(--cpu_hotplug_disabled < 0); |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1055 | if (cpumask_empty(frozen_cpus)) |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 1056 | goto out; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1057 | |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1058 | pr_info("Enabling non-boot CPUs ...\n"); |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1059 | |
| 1060 | arch_enable_nonboot_cpus_begin(); |
| 1061 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1062 | for_each_cpu(cpu, frozen_cpus) { |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1063 | trace_suspend_resume(TPS("CPU_ON"), cpu, true); |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1064 | error = _cpu_up(cpu, 1, CPUHP_ONLINE); |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1065 | trace_suspend_resume(TPS("CPU_ON"), cpu, false); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1066 | if (!error) { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1067 | pr_info("CPU%d is up\n", cpu); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1068 | continue; |
| 1069 | } |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1070 | pr_warn("Error taking CPU%d up: %d\n", cpu, error); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1071 | } |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1072 | |
| 1073 | arch_enable_nonboot_cpus_end(); |
| 1074 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1075 | cpumask_clear(frozen_cpus); |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 1076 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1077 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1078 | } |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1079 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 1080 | static int __init alloc_frozen_cpus(void) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1081 | { |
| 1082 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) |
| 1083 | return -ENOMEM; |
| 1084 | return 0; |
| 1085 | } |
| 1086 | core_initcall(alloc_frozen_cpus); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1087 | |
| 1088 | /* |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1089 | * When callbacks for CPU hotplug notifications are being executed, we must |
| 1090 | * ensure that the state of the system with respect to the tasks being frozen |
| 1091 | * or not, as reported by the notification, remains unchanged *throughout the |
| 1092 | * duration* of the execution of the callbacks. |
| 1093 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. |
| 1094 | * |
| 1095 | * This synchronization is implemented by mutually excluding regular CPU |
| 1096 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ |
| 1097 | * Hibernate notifications. |
| 1098 | */ |
| 1099 | static int |
| 1100 | cpu_hotplug_pm_callback(struct notifier_block *nb, |
| 1101 | unsigned long action, void *ptr) |
| 1102 | { |
| 1103 | switch (action) { |
| 1104 | |
| 1105 | case PM_SUSPEND_PREPARE: |
| 1106 | case PM_HIBERNATION_PREPARE: |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 1107 | cpu_hotplug_disable(); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1108 | break; |
| 1109 | |
| 1110 | case PM_POST_SUSPEND: |
| 1111 | case PM_POST_HIBERNATION: |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 1112 | cpu_hotplug_enable(); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1113 | break; |
| 1114 | |
| 1115 | default: |
| 1116 | return NOTIFY_DONE; |
| 1117 | } |
| 1118 | |
| 1119 | return NOTIFY_OK; |
| 1120 | } |
| 1121 | |
| 1122 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 1123 | static int __init cpu_hotplug_pm_sync_init(void) |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1124 | { |
Fenghua Yu | 6e32d47 | 2012-11-13 11:32:43 -0800 | [diff] [blame] | 1125 | /* |
| 1126 | * cpu_hotplug_pm_callback has higher priority than x86 |
| 1127 | * bsp_pm_callback which depends on cpu_hotplug_pm_callback |
| 1128 | * to disable cpu hotplug to avoid cpu hotplug race. |
| 1129 | */ |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1130 | pm_notifier(cpu_hotplug_pm_callback, 0); |
| 1131 | return 0; |
| 1132 | } |
| 1133 | core_initcall(cpu_hotplug_pm_sync_init); |
| 1134 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 1135 | #endif /* CONFIG_PM_SLEEP_SMP */ |
Max Krasnyansky | 68f4f1e | 2008-05-29 11:17:02 -0700 | [diff] [blame] | 1136 | |
| 1137 | #endif /* CONFIG_SMP */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1138 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1139 | /* Boot processor state steps */ |
| 1140 | static struct cpuhp_step cpuhp_bp_states[] = { |
| 1141 | [CPUHP_OFFLINE] = { |
| 1142 | .name = "offline", |
| 1143 | .startup = NULL, |
| 1144 | .teardown = NULL, |
| 1145 | }, |
| 1146 | #ifdef CONFIG_SMP |
| 1147 | [CPUHP_CREATE_THREADS]= { |
| 1148 | .name = "threads:create", |
| 1149 | .startup = smpboot_create_threads, |
| 1150 | .teardown = NULL, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1151 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1152 | }, |
| 1153 | [CPUHP_NOTIFY_PREPARE] = { |
| 1154 | .name = "notify:prepare", |
| 1155 | .startup = notify_prepare, |
| 1156 | .teardown = notify_dead, |
| 1157 | .skip_onerr = true, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1158 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1159 | }, |
| 1160 | [CPUHP_BRINGUP_CPU] = { |
| 1161 | .name = "cpu:bringup", |
| 1162 | .startup = bringup_cpu, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1163 | .teardown = NULL, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1164 | .cant_stop = true, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1165 | }, |
| 1166 | [CPUHP_TEARDOWN_CPU] = { |
| 1167 | .name = "cpu:teardown", |
| 1168 | .startup = NULL, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1169 | .teardown = takedown_cpu, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1170 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1171 | }, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1172 | #endif |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1173 | }; |
| 1174 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1175 | /* Application processor state steps */ |
| 1176 | static struct cpuhp_step cpuhp_ap_states[] = { |
| 1177 | #ifdef CONFIG_SMP |
| 1178 | [CPUHP_AP_NOTIFY_STARTING] = { |
| 1179 | .name = "notify:starting", |
| 1180 | .startup = notify_starting, |
| 1181 | .teardown = notify_dying, |
| 1182 | .skip_onerr = true, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1183 | .cant_stop = true, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1184 | }, |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1185 | [CPUHP_AP_SMPBOOT_THREADS] = { |
| 1186 | .name = "smpboot:threads", |
| 1187 | .startup = smpboot_unpark_threads, |
| 1188 | .teardown = smpboot_park_threads, |
| 1189 | }, |
| 1190 | [CPUHP_AP_NOTIFY_ONLINE] = { |
| 1191 | .name = "notify:online", |
| 1192 | .startup = notify_online, |
| 1193 | .teardown = notify_down_prepare, |
| 1194 | }, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1195 | #endif |
| 1196 | [CPUHP_ONLINE] = { |
| 1197 | .name = "online", |
| 1198 | .startup = NULL, |
| 1199 | .teardown = NULL, |
| 1200 | }, |
| 1201 | }; |
| 1202 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1203 | /* Sanity check for callbacks */ |
| 1204 | static int cpuhp_cb_check(enum cpuhp_state state) |
| 1205 | { |
| 1206 | if (state <= CPUHP_OFFLINE || state >= CPUHP_ONLINE) |
| 1207 | return -EINVAL; |
| 1208 | return 0; |
| 1209 | } |
| 1210 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1211 | static bool cpuhp_is_ap_state(enum cpuhp_state state) |
| 1212 | { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1213 | if (state >= CPUHP_AP_OFFLINE && state <= CPUHP_AP_ONLINE) |
| 1214 | return true; |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame^] | 1215 | return state > CPUHP_BRINGUP_CPU; |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1216 | } |
| 1217 | |
| 1218 | static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state) |
| 1219 | { |
| 1220 | struct cpuhp_step *sp; |
| 1221 | |
| 1222 | sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states; |
| 1223 | return sp + state; |
| 1224 | } |
| 1225 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1226 | static void cpuhp_store_callbacks(enum cpuhp_state state, |
| 1227 | const char *name, |
| 1228 | int (*startup)(unsigned int cpu), |
| 1229 | int (*teardown)(unsigned int cpu)) |
| 1230 | { |
| 1231 | /* (Un)Install the callbacks for further cpu hotplug operations */ |
| 1232 | struct cpuhp_step *sp; |
| 1233 | |
| 1234 | mutex_lock(&cpuhp_state_mutex); |
| 1235 | sp = cpuhp_get_step(state); |
| 1236 | sp->startup = startup; |
| 1237 | sp->teardown = teardown; |
| 1238 | sp->name = name; |
| 1239 | mutex_unlock(&cpuhp_state_mutex); |
| 1240 | } |
| 1241 | |
| 1242 | static void *cpuhp_get_teardown_cb(enum cpuhp_state state) |
| 1243 | { |
| 1244 | return cpuhp_get_step(state)->teardown; |
| 1245 | } |
| 1246 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1247 | /* |
| 1248 | * Call the startup/teardown function for a step either on the AP or |
| 1249 | * on the current CPU. |
| 1250 | */ |
| 1251 | static int cpuhp_issue_call(int cpu, enum cpuhp_state state, |
| 1252 | int (*cb)(unsigned int), bool bringup) |
| 1253 | { |
| 1254 | int ret; |
| 1255 | |
| 1256 | if (!cb) |
| 1257 | return 0; |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1258 | /* |
| 1259 | * The non AP bound callbacks can fail on bringup. On teardown |
| 1260 | * e.g. module removal we crash for now. |
| 1261 | */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1262 | #ifdef CONFIG_SMP |
| 1263 | if (cpuhp_is_ap_state(state)) |
| 1264 | ret = cpuhp_invoke_ap_callback(cpu, state, cb); |
| 1265 | else |
| 1266 | ret = cpuhp_invoke_callback(cpu, state, cb); |
| 1267 | #else |
| 1268 | ret = cpuhp_invoke_callback(cpu, state, cb); |
| 1269 | #endif |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1270 | BUG_ON(ret && !bringup); |
| 1271 | return ret; |
| 1272 | } |
| 1273 | |
| 1274 | /* |
| 1275 | * Called from __cpuhp_setup_state on a recoverable failure. |
| 1276 | * |
| 1277 | * Note: The teardown callbacks for rollback are not allowed to fail! |
| 1278 | */ |
| 1279 | static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state, |
| 1280 | int (*teardown)(unsigned int cpu)) |
| 1281 | { |
| 1282 | int cpu; |
| 1283 | |
| 1284 | if (!teardown) |
| 1285 | return; |
| 1286 | |
| 1287 | /* Roll back the already executed steps on the other cpus */ |
| 1288 | for_each_present_cpu(cpu) { |
| 1289 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1290 | int cpustate = st->state; |
| 1291 | |
| 1292 | if (cpu >= failedcpu) |
| 1293 | break; |
| 1294 | |
| 1295 | /* Did we invoke the startup call on that cpu ? */ |
| 1296 | if (cpustate >= state) |
| 1297 | cpuhp_issue_call(cpu, state, teardown, false); |
| 1298 | } |
| 1299 | } |
| 1300 | |
| 1301 | /* |
| 1302 | * Returns a free for dynamic slot assignment of the Online state. The states |
| 1303 | * are protected by the cpuhp_slot_states mutex and an empty slot is identified |
| 1304 | * by having no name assigned. |
| 1305 | */ |
| 1306 | static int cpuhp_reserve_state(enum cpuhp_state state) |
| 1307 | { |
| 1308 | enum cpuhp_state i; |
| 1309 | |
| 1310 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1311 | for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) { |
| 1312 | if (cpuhp_ap_states[i].name) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1313 | continue; |
| 1314 | |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1315 | cpuhp_ap_states[i].name = "Reserved"; |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1316 | mutex_unlock(&cpuhp_state_mutex); |
| 1317 | return i; |
| 1318 | } |
| 1319 | mutex_unlock(&cpuhp_state_mutex); |
| 1320 | WARN(1, "No more dynamic states available for CPU hotplug\n"); |
| 1321 | return -ENOSPC; |
| 1322 | } |
| 1323 | |
| 1324 | /** |
| 1325 | * __cpuhp_setup_state - Setup the callbacks for an hotplug machine state |
| 1326 | * @state: The state to setup |
| 1327 | * @invoke: If true, the startup function is invoked for cpus where |
| 1328 | * cpu state >= @state |
| 1329 | * @startup: startup callback function |
| 1330 | * @teardown: teardown callback function |
| 1331 | * |
| 1332 | * Returns 0 if successful, otherwise a proper error code |
| 1333 | */ |
| 1334 | int __cpuhp_setup_state(enum cpuhp_state state, |
| 1335 | const char *name, bool invoke, |
| 1336 | int (*startup)(unsigned int cpu), |
| 1337 | int (*teardown)(unsigned int cpu)) |
| 1338 | { |
| 1339 | int cpu, ret = 0; |
| 1340 | int dyn_state = 0; |
| 1341 | |
| 1342 | if (cpuhp_cb_check(state) || !name) |
| 1343 | return -EINVAL; |
| 1344 | |
| 1345 | get_online_cpus(); |
| 1346 | |
| 1347 | /* currently assignments for the ONLINE state are possible */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1348 | if (state == CPUHP_AP_ONLINE_DYN) { |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1349 | dyn_state = 1; |
| 1350 | ret = cpuhp_reserve_state(state); |
| 1351 | if (ret < 0) |
| 1352 | goto out; |
| 1353 | state = ret; |
| 1354 | } |
| 1355 | |
| 1356 | cpuhp_store_callbacks(state, name, startup, teardown); |
| 1357 | |
| 1358 | if (!invoke || !startup) |
| 1359 | goto out; |
| 1360 | |
| 1361 | /* |
| 1362 | * Try to call the startup callback for each present cpu |
| 1363 | * depending on the hotplug state of the cpu. |
| 1364 | */ |
| 1365 | for_each_present_cpu(cpu) { |
| 1366 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1367 | int cpustate = st->state; |
| 1368 | |
| 1369 | if (cpustate < state) |
| 1370 | continue; |
| 1371 | |
| 1372 | ret = cpuhp_issue_call(cpu, state, startup, true); |
| 1373 | if (ret) { |
| 1374 | cpuhp_rollback_install(cpu, state, teardown); |
| 1375 | cpuhp_store_callbacks(state, NULL, NULL, NULL); |
| 1376 | goto out; |
| 1377 | } |
| 1378 | } |
| 1379 | out: |
| 1380 | put_online_cpus(); |
| 1381 | if (!ret && dyn_state) |
| 1382 | return state; |
| 1383 | return ret; |
| 1384 | } |
| 1385 | EXPORT_SYMBOL(__cpuhp_setup_state); |
| 1386 | |
| 1387 | /** |
| 1388 | * __cpuhp_remove_state - Remove the callbacks for an hotplug machine state |
| 1389 | * @state: The state to remove |
| 1390 | * @invoke: If true, the teardown function is invoked for cpus where |
| 1391 | * cpu state >= @state |
| 1392 | * |
| 1393 | * The teardown callback is currently not allowed to fail. Think |
| 1394 | * about module removal! |
| 1395 | */ |
| 1396 | void __cpuhp_remove_state(enum cpuhp_state state, bool invoke) |
| 1397 | { |
| 1398 | int (*teardown)(unsigned int cpu) = cpuhp_get_teardown_cb(state); |
| 1399 | int cpu; |
| 1400 | |
| 1401 | BUG_ON(cpuhp_cb_check(state)); |
| 1402 | |
| 1403 | get_online_cpus(); |
| 1404 | |
| 1405 | if (!invoke || !teardown) |
| 1406 | goto remove; |
| 1407 | |
| 1408 | /* |
| 1409 | * Call the teardown callback for each present cpu depending |
| 1410 | * on the hotplug state of the cpu. This function is not |
| 1411 | * allowed to fail currently! |
| 1412 | */ |
| 1413 | for_each_present_cpu(cpu) { |
| 1414 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1415 | int cpustate = st->state; |
| 1416 | |
| 1417 | if (cpustate >= state) |
| 1418 | cpuhp_issue_call(cpu, state, teardown, false); |
| 1419 | } |
| 1420 | remove: |
| 1421 | cpuhp_store_callbacks(state, NULL, NULL, NULL); |
| 1422 | put_online_cpus(); |
| 1423 | } |
| 1424 | EXPORT_SYMBOL(__cpuhp_remove_state); |
| 1425 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1426 | #if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU) |
| 1427 | static ssize_t show_cpuhp_state(struct device *dev, |
| 1428 | struct device_attribute *attr, char *buf) |
| 1429 | { |
| 1430 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1431 | |
| 1432 | return sprintf(buf, "%d\n", st->state); |
| 1433 | } |
| 1434 | static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL); |
| 1435 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1436 | static ssize_t write_cpuhp_target(struct device *dev, |
| 1437 | struct device_attribute *attr, |
| 1438 | const char *buf, size_t count) |
| 1439 | { |
| 1440 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1441 | struct cpuhp_step *sp; |
| 1442 | int target, ret; |
| 1443 | |
| 1444 | ret = kstrtoint(buf, 10, &target); |
| 1445 | if (ret) |
| 1446 | return ret; |
| 1447 | |
| 1448 | #ifdef CONFIG_CPU_HOTPLUG_STATE_CONTROL |
| 1449 | if (target < CPUHP_OFFLINE || target > CPUHP_ONLINE) |
| 1450 | return -EINVAL; |
| 1451 | #else |
| 1452 | if (target != CPUHP_OFFLINE && target != CPUHP_ONLINE) |
| 1453 | return -EINVAL; |
| 1454 | #endif |
| 1455 | |
| 1456 | ret = lock_device_hotplug_sysfs(); |
| 1457 | if (ret) |
| 1458 | return ret; |
| 1459 | |
| 1460 | mutex_lock(&cpuhp_state_mutex); |
| 1461 | sp = cpuhp_get_step(target); |
| 1462 | ret = !sp->name || sp->cant_stop ? -EINVAL : 0; |
| 1463 | mutex_unlock(&cpuhp_state_mutex); |
| 1464 | if (ret) |
| 1465 | return ret; |
| 1466 | |
| 1467 | if (st->state < target) |
| 1468 | ret = do_cpu_up(dev->id, target); |
| 1469 | else |
| 1470 | ret = do_cpu_down(dev->id, target); |
| 1471 | |
| 1472 | unlock_device_hotplug(); |
| 1473 | return ret ? ret : count; |
| 1474 | } |
| 1475 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1476 | static ssize_t show_cpuhp_target(struct device *dev, |
| 1477 | struct device_attribute *attr, char *buf) |
| 1478 | { |
| 1479 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1480 | |
| 1481 | return sprintf(buf, "%d\n", st->target); |
| 1482 | } |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1483 | static DEVICE_ATTR(target, 0644, show_cpuhp_target, write_cpuhp_target); |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1484 | |
| 1485 | static struct attribute *cpuhp_cpu_attrs[] = { |
| 1486 | &dev_attr_state.attr, |
| 1487 | &dev_attr_target.attr, |
| 1488 | NULL |
| 1489 | }; |
| 1490 | |
| 1491 | static struct attribute_group cpuhp_cpu_attr_group = { |
| 1492 | .attrs = cpuhp_cpu_attrs, |
| 1493 | .name = "hotplug", |
| 1494 | NULL |
| 1495 | }; |
| 1496 | |
| 1497 | static ssize_t show_cpuhp_states(struct device *dev, |
| 1498 | struct device_attribute *attr, char *buf) |
| 1499 | { |
| 1500 | ssize_t cur, res = 0; |
| 1501 | int i; |
| 1502 | |
| 1503 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1504 | for (i = CPUHP_OFFLINE; i <= CPUHP_ONLINE; i++) { |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1505 | struct cpuhp_step *sp = cpuhp_get_step(i); |
| 1506 | |
| 1507 | if (sp->name) { |
| 1508 | cur = sprintf(buf, "%3d: %s\n", i, sp->name); |
| 1509 | buf += cur; |
| 1510 | res += cur; |
| 1511 | } |
| 1512 | } |
| 1513 | mutex_unlock(&cpuhp_state_mutex); |
| 1514 | return res; |
| 1515 | } |
| 1516 | static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL); |
| 1517 | |
| 1518 | static struct attribute *cpuhp_cpu_root_attrs[] = { |
| 1519 | &dev_attr_states.attr, |
| 1520 | NULL |
| 1521 | }; |
| 1522 | |
| 1523 | static struct attribute_group cpuhp_cpu_root_attr_group = { |
| 1524 | .attrs = cpuhp_cpu_root_attrs, |
| 1525 | .name = "hotplug", |
| 1526 | NULL |
| 1527 | }; |
| 1528 | |
| 1529 | static int __init cpuhp_sysfs_init(void) |
| 1530 | { |
| 1531 | int cpu, ret; |
| 1532 | |
| 1533 | ret = sysfs_create_group(&cpu_subsys.dev_root->kobj, |
| 1534 | &cpuhp_cpu_root_attr_group); |
| 1535 | if (ret) |
| 1536 | return ret; |
| 1537 | |
| 1538 | for_each_possible_cpu(cpu) { |
| 1539 | struct device *dev = get_cpu_device(cpu); |
| 1540 | |
| 1541 | if (!dev) |
| 1542 | continue; |
| 1543 | ret = sysfs_create_group(&dev->kobj, &cpuhp_cpu_attr_group); |
| 1544 | if (ret) |
| 1545 | return ret; |
| 1546 | } |
| 1547 | return 0; |
| 1548 | } |
| 1549 | device_initcall(cpuhp_sysfs_init); |
| 1550 | #endif |
| 1551 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1552 | /* |
| 1553 | * cpu_bit_bitmap[] is a special, "compressed" data structure that |
| 1554 | * represents all NR_CPUS bits binary values of 1<<nr. |
| 1555 | * |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1556 | * 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] | 1557 | * mask value that has a single bit set only. |
| 1558 | */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1559 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1560 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 1561 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1562 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) |
| 1563 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) |
| 1564 | #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] | 1565 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1566 | 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] | 1567 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1568 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), |
| 1569 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), |
| 1570 | #if BITS_PER_LONG > 32 |
| 1571 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), |
| 1572 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1573 | #endif |
| 1574 | }; |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1575 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1576 | |
| 1577 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; |
| 1578 | EXPORT_SYMBOL(cpu_all_bits); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1579 | |
| 1580 | #ifdef CONFIG_INIT_ALL_POSSIBLE |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1581 | struct cpumask __cpu_possible_mask __read_mostly |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1582 | = {CPU_BITS_ALL}; |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1583 | #else |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1584 | struct cpumask __cpu_possible_mask __read_mostly; |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1585 | #endif |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1586 | EXPORT_SYMBOL(__cpu_possible_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1587 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1588 | struct cpumask __cpu_online_mask __read_mostly; |
| 1589 | EXPORT_SYMBOL(__cpu_online_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1590 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1591 | struct cpumask __cpu_present_mask __read_mostly; |
| 1592 | EXPORT_SYMBOL(__cpu_present_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1593 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1594 | struct cpumask __cpu_active_mask __read_mostly; |
| 1595 | EXPORT_SYMBOL(__cpu_active_mask); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1596 | |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1597 | void init_cpu_present(const struct cpumask *src) |
| 1598 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1599 | cpumask_copy(&__cpu_present_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1600 | } |
| 1601 | |
| 1602 | void init_cpu_possible(const struct cpumask *src) |
| 1603 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1604 | cpumask_copy(&__cpu_possible_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1605 | } |
| 1606 | |
| 1607 | void init_cpu_online(const struct cpumask *src) |
| 1608 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1609 | cpumask_copy(&__cpu_online_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1610 | } |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1611 | |
| 1612 | /* |
| 1613 | * Activate the first processor. |
| 1614 | */ |
| 1615 | void __init boot_cpu_init(void) |
| 1616 | { |
| 1617 | int cpu = smp_processor_id(); |
| 1618 | |
| 1619 | /* Mark the boot cpu "present", "online" etc for SMP and UP case */ |
| 1620 | set_cpu_online(cpu, true); |
| 1621 | set_cpu_active(cpu, true); |
| 1622 | set_cpu_present(cpu, true); |
| 1623 | set_cpu_possible(cpu, true); |
| 1624 | } |
| 1625 | |
| 1626 | /* |
| 1627 | * Must be called _AFTER_ setting up the per_cpu areas |
| 1628 | */ |
| 1629 | void __init boot_cpu_state_init(void) |
| 1630 | { |
| 1631 | per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE; |
| 1632 | } |