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 | 81615b62 | 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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 23 | #include "smpboot.h" |
| 24 | |
Rusty Russell | 98a79d6 | 2008-12-13 21:19:41 +1030 | [diff] [blame] | 25 | #ifdef CONFIG_SMP |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 26 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 27 | static DEFINE_MUTEX(cpu_add_remove_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 29 | /* |
| 30 | * The following two API's must be used when attempting |
| 31 | * to serialize the updates to cpu_online_mask, cpu_present_mask. |
| 32 | */ |
| 33 | void cpu_maps_update_begin(void) |
| 34 | { |
| 35 | mutex_lock(&cpu_add_remove_lock); |
| 36 | } |
| 37 | |
| 38 | void cpu_maps_update_done(void) |
| 39 | { |
| 40 | mutex_unlock(&cpu_add_remove_lock); |
| 41 | } |
| 42 | |
Daniel J Blueman | 5c113fb | 2010-06-01 12:15:11 +0100 | [diff] [blame] | 43 | static RAW_NOTIFIER_HEAD(cpu_chain); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 45 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
| 46 | * Should always be manipulated under cpu_add_remove_lock |
| 47 | */ |
| 48 | static int cpu_hotplug_disabled; |
| 49 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 50 | #ifdef CONFIG_HOTPLUG_CPU |
| 51 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 52 | static struct { |
| 53 | struct task_struct *active_writer; |
| 54 | struct mutex lock; /* Synchronizes accesses to refcount, */ |
| 55 | /* |
| 56 | * Also blocks the new readers during |
| 57 | * an ongoing cpu hotplug operation. |
| 58 | */ |
| 59 | int refcount; |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 60 | } cpu_hotplug = { |
| 61 | .active_writer = NULL, |
| 62 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), |
| 63 | .refcount = 0, |
| 64 | }; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 65 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 66 | void get_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 67 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 68 | might_sleep(); |
| 69 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 70 | return; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 71 | mutex_lock(&cpu_hotplug.lock); |
| 72 | cpu_hotplug.refcount++; |
| 73 | mutex_unlock(&cpu_hotplug.lock); |
| 74 | |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 75 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 76 | EXPORT_SYMBOL_GPL(get_online_cpus); |
Ashok Raj | 90d45d1 | 2005-11-08 21:34:24 -0800 | [diff] [blame] | 77 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 78 | void put_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 79 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 80 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 81 | return; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 82 | mutex_lock(&cpu_hotplug.lock); |
Srivatsa S. Bhat | 075663d | 2012-10-08 16:28:20 -0700 | [diff] [blame] | 83 | |
| 84 | if (WARN_ON(!cpu_hotplug.refcount)) |
| 85 | cpu_hotplug.refcount++; /* try to fix things up */ |
| 86 | |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 87 | if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer)) |
| 88 | wake_up_process(cpu_hotplug.active_writer); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 89 | mutex_unlock(&cpu_hotplug.lock); |
| 90 | |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 91 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 92 | EXPORT_SYMBOL_GPL(put_online_cpus); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 93 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 94 | /* |
| 95 | * This ensures that the hotplug operation can begin only when the |
| 96 | * refcount goes to zero. |
| 97 | * |
| 98 | * Note that during a cpu-hotplug operation, the new readers, if any, |
| 99 | * will be blocked by the cpu_hotplug.lock |
| 100 | * |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 101 | * Since cpu_hotplug_begin() is always called after invoking |
| 102 | * 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] | 103 | * |
| 104 | * Note that theoretically, there is a possibility of a livelock: |
| 105 | * - Refcount goes to zero, last reader wakes up the sleeping |
| 106 | * writer. |
| 107 | * - Last reader unlocks the cpu_hotplug.lock. |
| 108 | * - A new reader arrives at this moment, bumps up the refcount. |
| 109 | * - The writer acquires the cpu_hotplug.lock finds the refcount |
| 110 | * non zero and goes to sleep again. |
| 111 | * |
| 112 | * However, this is very difficult to achieve in practice since |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 113 | * 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] | 114 | * |
| 115 | */ |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 116 | void cpu_hotplug_begin(void) |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 117 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 118 | cpu_hotplug.active_writer = current; |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 119 | |
| 120 | for (;;) { |
| 121 | mutex_lock(&cpu_hotplug.lock); |
| 122 | if (likely(!cpu_hotplug.refcount)) |
| 123 | break; |
| 124 | __set_current_state(TASK_UNINTERRUPTIBLE); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 125 | mutex_unlock(&cpu_hotplug.lock); |
| 126 | schedule(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 127 | } |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 128 | } |
| 129 | |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 130 | void cpu_hotplug_done(void) |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 131 | { |
| 132 | cpu_hotplug.active_writer = NULL; |
| 133 | mutex_unlock(&cpu_hotplug.lock); |
| 134 | } |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 135 | |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 136 | /* |
| 137 | * Wait for currently running CPU hotplug operations to complete (if any) and |
| 138 | * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects |
| 139 | * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the |
| 140 | * hotplug path before performing hotplug operations. So acquiring that lock |
| 141 | * guarantees mutual exclusion from any currently running hotplug operations. |
| 142 | */ |
| 143 | void cpu_hotplug_disable(void) |
| 144 | { |
| 145 | cpu_maps_update_begin(); |
| 146 | cpu_hotplug_disabled = 1; |
| 147 | cpu_maps_update_done(); |
| 148 | } |
| 149 | |
| 150 | void cpu_hotplug_enable(void) |
| 151 | { |
| 152 | cpu_maps_update_begin(); |
| 153 | cpu_hotplug_disabled = 0; |
| 154 | cpu_maps_update_done(); |
| 155 | } |
| 156 | |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 157 | #endif /* CONFIG_HOTPLUG_CPU */ |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 158 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 159 | /* Need to know about CPUs going up/down? */ |
Sam Ravnborg | f7b16c1 | 2008-04-29 00:58:51 -0700 | [diff] [blame] | 160 | int __ref register_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | { |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 162 | int ret; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 163 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 164 | ret = raw_notifier_chain_register(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 165 | cpu_maps_update_done(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 166 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | } |
Chandra Seetharaman | 65edc68 | 2006-06-27 02:54:08 -0700 | [diff] [blame] | 168 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 169 | static int __cpu_notify(unsigned long val, void *v, int nr_to_call, |
| 170 | int *nr_calls) |
| 171 | { |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 172 | int ret; |
| 173 | |
| 174 | ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call, |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 175 | nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 176 | |
| 177 | return notifier_to_errno(ret); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 178 | } |
| 179 | |
| 180 | static int cpu_notify(unsigned long val, void *v) |
| 181 | { |
| 182 | return __cpu_notify(val, v, -1, NULL); |
| 183 | } |
| 184 | |
Linus Torvalds | 00b9b0a | 2010-05-27 10:32:08 -0700 | [diff] [blame] | 185 | #ifdef CONFIG_HOTPLUG_CPU |
| 186 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 187 | static void cpu_notify_nofail(unsigned long val, void *v) |
| 188 | { |
Linus Torvalds | 00b9b0a | 2010-05-27 10:32:08 -0700 | [diff] [blame] | 189 | BUG_ON(cpu_notify(val, v)); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 190 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | EXPORT_SYMBOL(register_cpu_notifier); |
| 192 | |
Sam Ravnborg | 9647155 | 2008-04-29 00:58:48 -0700 | [diff] [blame] | 193 | void __ref unregister_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 195 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 196 | raw_notifier_chain_unregister(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 197 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | } |
| 199 | EXPORT_SYMBOL(unregister_cpu_notifier); |
| 200 | |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 201 | /** |
| 202 | * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU |
| 203 | * @cpu: a CPU id |
| 204 | * |
| 205 | * This function walks all processes, finds a valid mm struct for each one and |
| 206 | * then clears a corresponding bit in mm's cpumask. While this all sounds |
| 207 | * trivial, there are various non-obvious corner cases, which this function |
| 208 | * tries to solve in a safe manner. |
| 209 | * |
| 210 | * Also note that the function uses a somewhat relaxed locking scheme, so it may |
| 211 | * be called only for an already offlined CPU. |
| 212 | */ |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 213 | void clear_tasks_mm_cpumask(int cpu) |
| 214 | { |
| 215 | struct task_struct *p; |
| 216 | |
| 217 | /* |
| 218 | * This function is called after the cpu is taken down and marked |
| 219 | * offline, so its not like new tasks will ever get this cpu set in |
| 220 | * their mm mask. -- Peter Zijlstra |
| 221 | * Thus, we may use rcu_read_lock() here, instead of grabbing |
| 222 | * full-fledged tasklist_lock. |
| 223 | */ |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 224 | WARN_ON(cpu_online(cpu)); |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 225 | rcu_read_lock(); |
| 226 | for_each_process(p) { |
| 227 | struct task_struct *t; |
| 228 | |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 229 | /* |
| 230 | * Main thread might exit, but other threads may still have |
| 231 | * a valid mm. Find one. |
| 232 | */ |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 233 | t = find_lock_task_mm(p); |
| 234 | if (!t) |
| 235 | continue; |
| 236 | cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); |
| 237 | task_unlock(t); |
| 238 | } |
| 239 | rcu_read_unlock(); |
| 240 | } |
| 241 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | static inline void check_for_tasks(int cpu) |
| 243 | { |
| 244 | struct task_struct *p; |
Frederic Weisbecker | 6fac482 | 2012-11-13 14:20:55 +0100 | [diff] [blame] | 245 | cputime_t utime, stime; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | |
| 247 | write_lock_irq(&tasklist_lock); |
| 248 | for_each_process(p) { |
Frederic Weisbecker | 6fac482 | 2012-11-13 14:20:55 +0100 | [diff] [blame] | 249 | task_cputime(p, &utime, &stime); |
Peter Zijlstra | 1185424 | 2010-01-21 16:34:27 +0100 | [diff] [blame] | 250 | if (task_cpu(p) == cpu && p->state == TASK_RUNNING && |
Frederic Weisbecker | 6fac482 | 2012-11-13 14:20:55 +0100 | [diff] [blame] | 251 | (utime || stime)) |
Frans Pop | 9d3cfc4 | 2010-01-25 14:56:34 +0100 | [diff] [blame] | 252 | printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d " |
| 253 | "(state = %ld, flags = %x)\n", |
| 254 | p->comm, task_pid_nr(p), cpu, |
| 255 | p->state, p->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | } |
| 257 | write_unlock_irq(&tasklist_lock); |
| 258 | } |
| 259 | |
Avi Kivity | db912f9 | 2007-05-24 12:23:10 +0300 | [diff] [blame] | 260 | struct take_cpu_down_param { |
| 261 | unsigned long mod; |
| 262 | void *hcpu; |
| 263 | }; |
| 264 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | /* Take this CPU down. */ |
Sam Ravnborg | 514a20a | 2008-04-29 00:58:50 -0700 | [diff] [blame] | 266 | static int __ref take_cpu_down(void *_param) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | { |
Avi Kivity | db912f9 | 2007-05-24 12:23:10 +0300 | [diff] [blame] | 268 | struct take_cpu_down_param *param = _param; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | int err; |
| 270 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | /* Ensure this CPU doesn't handle any more interrupts. */ |
| 272 | err = __cpu_disable(); |
| 273 | if (err < 0) |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 274 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 276 | cpu_notify(CPU_DYING | param->mod, param->hcpu); |
Thomas Gleixner | 14e568e | 2013-01-31 12:11:14 +0000 | [diff] [blame] | 277 | /* Park the stopper thread */ |
| 278 | kthread_park(current); |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 279 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | } |
| 281 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 282 | /* Requires cpu_add_remove_lock to be held */ |
Sam Ravnborg | 514a20a | 2008-04-29 00:58:50 -0700 | [diff] [blame] | 283 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | { |
Heiko Carstens | e7407dc | 2007-05-09 02:34:04 -0700 | [diff] [blame] | 285 | int err, nr_calls = 0; |
Heiko Carstens | e7407dc | 2007-05-09 02:34:04 -0700 | [diff] [blame] | 286 | void *hcpu = (void *)(long)cpu; |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 287 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; |
Avi Kivity | db912f9 | 2007-05-24 12:23:10 +0300 | [diff] [blame] | 288 | struct take_cpu_down_param tcd_param = { |
| 289 | .mod = mod, |
| 290 | .hcpu = hcpu, |
| 291 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 293 | if (num_online_cpus() == 1) |
| 294 | return -EBUSY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 296 | if (!cpu_online(cpu)) |
| 297 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 299 | cpu_hotplug_begin(); |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 300 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 301 | err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 302 | if (err) { |
Akinobu Mita | a0d8cdb | 2007-10-18 03:05:12 -0700 | [diff] [blame] | 303 | nr_calls--; |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 304 | __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 305 | printk("%s: attempt to take down CPU %u failed\n", |
Harvey Harrison | af1f16d | 2008-04-30 00:55:08 -0700 | [diff] [blame] | 306 | __func__, cpu); |
Gautham R Shenoy | baaca49 | 2007-05-09 02:34:03 -0700 | [diff] [blame] | 307 | goto out_release; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 308 | } |
| 309 | |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 310 | /* |
| 311 | * By now we've cleared cpu_active_mask, wait for all preempt-disabled |
| 312 | * and RCU users of this state to go away such that all new such users |
| 313 | * will observe it. |
| 314 | * |
| 315 | * For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might |
| 316 | * not imply sync_sched(), so explicitly call both. |
Michael wang | 106dd5a | 2013-11-13 11:10:56 +0800 | [diff] [blame] | 317 | * |
| 318 | * 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] | 319 | */ |
| 320 | #ifdef CONFIG_PREEMPT |
| 321 | synchronize_sched(); |
| 322 | #endif |
| 323 | synchronize_rcu(); |
| 324 | |
Michael wang | 106dd5a | 2013-11-13 11:10:56 +0800 | [diff] [blame] | 325 | smpboot_park_threads(cpu); |
| 326 | |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 327 | /* |
| 328 | * So now all preempt/rcu users must observe !cpu_active(). |
| 329 | */ |
| 330 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 331 | err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 332 | if (err) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | /* CPU didn't die: tell everyone. Can't complain. */ |
Thomas Gleixner | f97f8f0 | 2012-07-16 10:42:36 +0000 | [diff] [blame] | 334 | smpboot_unpark_threads(cpu); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 335 | cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu); |
Oleg Nesterov | 6a1bdc1 | 2010-03-15 10:10:23 +0100 | [diff] [blame] | 336 | goto out_release; |
Satoru Takeuchi | 8fa1d7d | 2006-10-28 10:38:57 -0700 | [diff] [blame] | 337 | } |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 338 | BUG_ON(cpu_online(cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | |
Peter Zijlstra | 48c5ccae | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 340 | /* |
| 341 | * The migration_call() CPU_DYING callback will have removed all |
| 342 | * runnable tasks from the cpu, there's only the idle task left now |
| 343 | * that the migration thread is done doing the stop_machine thing. |
Peter Zijlstra | 51a96c7 | 2010-11-19 20:37:53 +0100 | [diff] [blame] | 344 | * |
| 345 | * Wait for the stop thread to go away. |
Peter Zijlstra | 48c5ccae | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 346 | */ |
Peter Zijlstra | 51a96c7 | 2010-11-19 20:37:53 +0100 | [diff] [blame] | 347 | while (!idle_cpu(cpu)) |
| 348 | cpu_relax(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | |
| 350 | /* This actually kills the CPU. */ |
| 351 | __cpu_die(cpu); |
| 352 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | /* CPU is completely dead: tell everyone. Too late to complain. */ |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 354 | cpu_notify_nofail(CPU_DEAD | mod, hcpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 355 | |
| 356 | check_for_tasks(cpu); |
| 357 | |
Gautham R Shenoy | baaca49 | 2007-05-09 02:34:03 -0700 | [diff] [blame] | 358 | out_release: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 359 | cpu_hotplug_done(); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 360 | if (!err) |
| 361 | cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 362 | return err; |
| 363 | } |
| 364 | |
Sam Ravnborg | 514a20a | 2008-04-29 00:58:50 -0700 | [diff] [blame] | 365 | int __ref cpu_down(unsigned int cpu) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 366 | { |
Heiko Carstens | 9ea09af | 2008-12-22 12:36:30 +0100 | [diff] [blame] | 367 | int err; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 368 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 369 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 370 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 371 | if (cpu_hotplug_disabled) { |
| 372 | err = -EBUSY; |
| 373 | goto out; |
| 374 | } |
| 375 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 376 | err = _cpu_down(cpu, 0); |
| 377 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 378 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 379 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | return err; |
| 381 | } |
Zhang Rui | b62b8ef | 2008-04-29 02:35:56 -0400 | [diff] [blame] | 382 | EXPORT_SYMBOL(cpu_down); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | #endif /*CONFIG_HOTPLUG_CPU*/ |
| 384 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 385 | /* Requires cpu_add_remove_lock to be held */ |
Paul Gortmaker | 0db0628 | 2013-06-19 14:53:51 -0400 | [diff] [blame] | 386 | static int _cpu_up(unsigned int cpu, int tasks_frozen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | { |
Gautham R Shenoy | baaca49 | 2007-05-09 02:34:03 -0700 | [diff] [blame] | 388 | int ret, nr_calls = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 389 | void *hcpu = (void *)(long)cpu; |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 390 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 391 | struct task_struct *idle; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 393 | cpu_hotplug_begin(); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 394 | |
Yasuaki Ishimatsu | 5e5041f | 2012-10-23 01:30:54 +0200 | [diff] [blame] | 395 | if (cpu_online(cpu) || !cpu_present(cpu)) { |
| 396 | ret = -EINVAL; |
| 397 | goto out; |
| 398 | } |
| 399 | |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 400 | idle = idle_thread_get(cpu); |
| 401 | if (IS_ERR(idle)) { |
| 402 | ret = PTR_ERR(idle); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 403 | goto out; |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 404 | } |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 405 | |
Thomas Gleixner | f97f8f0 | 2012-07-16 10:42:36 +0000 | [diff] [blame] | 406 | ret = smpboot_create_threads(cpu); |
| 407 | if (ret) |
| 408 | goto out; |
| 409 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 410 | ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 411 | if (ret) { |
Akinobu Mita | a0d8cdb | 2007-10-18 03:05:12 -0700 | [diff] [blame] | 412 | nr_calls--; |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 413 | printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", |
Harvey Harrison | af1f16d | 2008-04-30 00:55:08 -0700 | [diff] [blame] | 414 | __func__, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | goto out_notify; |
| 416 | } |
| 417 | |
| 418 | /* Arch-specific enabling code. */ |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 419 | ret = __cpu_up(cpu, idle); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | if (ret != 0) |
| 421 | goto out_notify; |
Eric Sesterhenn | 6978c70 | 2006-03-24 18:45:21 +0100 | [diff] [blame] | 422 | BUG_ON(!cpu_online(cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | |
Thomas Gleixner | f97f8f0 | 2012-07-16 10:42:36 +0000 | [diff] [blame] | 424 | /* Wake the per cpu threads */ |
| 425 | smpboot_unpark_threads(cpu); |
| 426 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | /* Now call notifier in preparation. */ |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 428 | cpu_notify(CPU_ONLINE | mod, hcpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | |
| 430 | out_notify: |
| 431 | if (ret != 0) |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 432 | __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 433 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 434 | cpu_hotplug_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 435 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | return ret; |
| 437 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 438 | |
Paul Gortmaker | 0db0628 | 2013-06-19 14:53:51 -0400 | [diff] [blame] | 439 | int cpu_up(unsigned int cpu) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 440 | { |
| 441 | int err = 0; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 442 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 443 | if (!cpu_possible(cpu)) { |
KAMEZAWA Hiroyuki | 73e753a | 2007-10-18 23:40:47 -0700 | [diff] [blame] | 444 | printk(KERN_ERR "can't online cpu %d because it is not " |
| 445 | "configured as may-hotadd at boot time\n", cpu); |
Chen Gong | 87d5e023 | 2010-03-05 13:42:38 -0800 | [diff] [blame] | 446 | #if defined(CONFIG_IA64) |
KAMEZAWA Hiroyuki | 73e753a | 2007-10-18 23:40:47 -0700 | [diff] [blame] | 447 | printk(KERN_ERR "please check additional_cpus= boot " |
| 448 | "parameter\n"); |
| 449 | #endif |
| 450 | return -EINVAL; |
| 451 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 452 | |
Toshi Kani | 01b0f19 | 2013-11-12 15:07:25 -0800 | [diff] [blame] | 453 | err = try_online_node(cpu_to_node(cpu)); |
| 454 | if (err) |
| 455 | return err; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 456 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 457 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 458 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 459 | if (cpu_hotplug_disabled) { |
| 460 | err = -EBUSY; |
| 461 | goto out; |
| 462 | } |
| 463 | |
| 464 | err = _cpu_up(cpu, 0); |
| 465 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 466 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 467 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 468 | return err; |
| 469 | } |
Paul E. McKenney | a513f6b | 2011-12-11 21:54:45 -0800 | [diff] [blame] | 470 | EXPORT_SYMBOL_GPL(cpu_up); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 471 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 472 | #ifdef CONFIG_PM_SLEEP_SMP |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 473 | static cpumask_var_t frozen_cpus; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 474 | |
| 475 | int disable_nonboot_cpus(void) |
| 476 | { |
Rafael J. Wysocki | e9a5f42 | 2010-05-27 22:16:22 +0200 | [diff] [blame] | 477 | int cpu, first_cpu, error = 0; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 478 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 479 | cpu_maps_update_begin(); |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 480 | first_cpu = cpumask_first(cpu_online_mask); |
Xiaotian Feng | 9ee349a | 2009-12-16 18:04:32 +0100 | [diff] [blame] | 481 | /* |
| 482 | * 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] | 483 | * with the userspace trying to use the CPU hotplug at the same time |
| 484 | */ |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 485 | cpumask_clear(frozen_cpus); |
Peter Zijlstra | 6ad4c18 | 2009-11-25 13:31:39 +0100 | [diff] [blame] | 486 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 487 | printk("Disabling non-boot CPUs ...\n"); |
| 488 | for_each_online_cpu(cpu) { |
| 489 | if (cpu == first_cpu) |
| 490 | continue; |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 491 | error = _cpu_down(cpu, 1); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 492 | if (!error) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 493 | cpumask_set_cpu(cpu, frozen_cpus); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 494 | else { |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 495 | printk(KERN_ERR "Error taking CPU%d down: %d\n", |
| 496 | cpu, error); |
| 497 | break; |
| 498 | } |
| 499 | } |
Joseph Cihula | 86886e5 | 2009-06-30 19:31:07 -0700 | [diff] [blame] | 500 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 501 | if (!error) { |
| 502 | BUG_ON(num_online_cpus() > 1); |
| 503 | /* Make sure the CPUs won't be enabled by someone else */ |
| 504 | cpu_hotplug_disabled = 1; |
| 505 | } else { |
Ingo Molnar | e1d9fd2 | 2006-12-23 16:55:29 +0100 | [diff] [blame] | 506 | printk(KERN_ERR "Non-boot CPUs are not disabled\n"); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 507 | } |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 508 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 509 | return error; |
| 510 | } |
| 511 | |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 512 | void __weak arch_enable_nonboot_cpus_begin(void) |
| 513 | { |
| 514 | } |
| 515 | |
| 516 | void __weak arch_enable_nonboot_cpus_end(void) |
| 517 | { |
| 518 | } |
| 519 | |
Sam Ravnborg | fa7303e | 2008-02-08 04:21:55 -0800 | [diff] [blame] | 520 | void __ref enable_nonboot_cpus(void) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 521 | { |
| 522 | int cpu, error; |
| 523 | |
| 524 | /* Allow everyone to use the CPU hotplug again */ |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 525 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 526 | cpu_hotplug_disabled = 0; |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 527 | if (cpumask_empty(frozen_cpus)) |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 528 | goto out; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 529 | |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 530 | printk(KERN_INFO "Enabling non-boot CPUs ...\n"); |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 531 | |
| 532 | arch_enable_nonboot_cpus_begin(); |
| 533 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 534 | for_each_cpu(cpu, frozen_cpus) { |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 535 | error = _cpu_up(cpu, 1); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 536 | if (!error) { |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 537 | printk(KERN_INFO "CPU%d is up\n", cpu); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 538 | continue; |
| 539 | } |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 540 | printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 541 | } |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 542 | |
| 543 | arch_enable_nonboot_cpus_end(); |
| 544 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 545 | cpumask_clear(frozen_cpus); |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 546 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 547 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 548 | } |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 549 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 550 | static int __init alloc_frozen_cpus(void) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 551 | { |
| 552 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) |
| 553 | return -ENOMEM; |
| 554 | return 0; |
| 555 | } |
| 556 | core_initcall(alloc_frozen_cpus); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 557 | |
| 558 | /* |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 559 | * When callbacks for CPU hotplug notifications are being executed, we must |
| 560 | * ensure that the state of the system with respect to the tasks being frozen |
| 561 | * or not, as reported by the notification, remains unchanged *throughout the |
| 562 | * duration* of the execution of the callbacks. |
| 563 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. |
| 564 | * |
| 565 | * This synchronization is implemented by mutually excluding regular CPU |
| 566 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ |
| 567 | * Hibernate notifications. |
| 568 | */ |
| 569 | static int |
| 570 | cpu_hotplug_pm_callback(struct notifier_block *nb, |
| 571 | unsigned long action, void *ptr) |
| 572 | { |
| 573 | switch (action) { |
| 574 | |
| 575 | case PM_SUSPEND_PREPARE: |
| 576 | case PM_HIBERNATION_PREPARE: |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 577 | cpu_hotplug_disable(); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 578 | break; |
| 579 | |
| 580 | case PM_POST_SUSPEND: |
| 581 | case PM_POST_HIBERNATION: |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 582 | cpu_hotplug_enable(); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 583 | break; |
| 584 | |
| 585 | default: |
| 586 | return NOTIFY_DONE; |
| 587 | } |
| 588 | |
| 589 | return NOTIFY_OK; |
| 590 | } |
| 591 | |
| 592 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 593 | static int __init cpu_hotplug_pm_sync_init(void) |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 594 | { |
Fenghua Yu | 6e32d47 | 2012-11-13 11:32:43 -0800 | [diff] [blame] | 595 | /* |
| 596 | * cpu_hotplug_pm_callback has higher priority than x86 |
| 597 | * bsp_pm_callback which depends on cpu_hotplug_pm_callback |
| 598 | * to disable cpu hotplug to avoid cpu hotplug race. |
| 599 | */ |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 600 | pm_notifier(cpu_hotplug_pm_callback, 0); |
| 601 | return 0; |
| 602 | } |
| 603 | core_initcall(cpu_hotplug_pm_sync_init); |
| 604 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 605 | #endif /* CONFIG_PM_SLEEP_SMP */ |
Max Krasnyansky | 68f4f1e | 2008-05-29 11:17:02 -0700 | [diff] [blame] | 606 | |
Manfred Spraul | e545a61 | 2008-09-07 16:57:22 +0200 | [diff] [blame] | 607 | /** |
| 608 | * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers |
| 609 | * @cpu: cpu that just started |
| 610 | * |
| 611 | * This function calls the cpu_chain notifiers with CPU_STARTING. |
| 612 | * It must be called by the arch code on the new cpu, before the new cpu |
| 613 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). |
| 614 | */ |
Paul Gortmaker | 0db0628 | 2013-06-19 14:53:51 -0400 | [diff] [blame] | 615 | void notify_cpu_starting(unsigned int cpu) |
Manfred Spraul | e545a61 | 2008-09-07 16:57:22 +0200 | [diff] [blame] | 616 | { |
| 617 | unsigned long val = CPU_STARTING; |
| 618 | |
| 619 | #ifdef CONFIG_PM_SLEEP_SMP |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 620 | if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus)) |
Manfred Spraul | e545a61 | 2008-09-07 16:57:22 +0200 | [diff] [blame] | 621 | val = CPU_STARTING_FROZEN; |
| 622 | #endif /* CONFIG_PM_SLEEP_SMP */ |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 623 | cpu_notify(val, (void *)(long)cpu); |
Manfred Spraul | e545a61 | 2008-09-07 16:57:22 +0200 | [diff] [blame] | 624 | } |
| 625 | |
Max Krasnyansky | 68f4f1e | 2008-05-29 11:17:02 -0700 | [diff] [blame] | 626 | #endif /* CONFIG_SMP */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 627 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 628 | /* |
| 629 | * cpu_bit_bitmap[] is a special, "compressed" data structure that |
| 630 | * represents all NR_CPUS bits binary values of 1<<nr. |
| 631 | * |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 632 | * 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] | 633 | * mask value that has a single bit set only. |
| 634 | */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 635 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 636 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 637 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 638 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) |
| 639 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) |
| 640 | #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] | 641 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 642 | 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] | 643 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 644 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), |
| 645 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), |
| 646 | #if BITS_PER_LONG > 32 |
| 647 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), |
| 648 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 649 | #endif |
| 650 | }; |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 651 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 652 | |
| 653 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; |
| 654 | EXPORT_SYMBOL(cpu_all_bits); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 655 | |
| 656 | #ifdef CONFIG_INIT_ALL_POSSIBLE |
| 657 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly |
| 658 | = CPU_BITS_ALL; |
| 659 | #else |
| 660 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly; |
| 661 | #endif |
| 662 | const struct cpumask *const cpu_possible_mask = to_cpumask(cpu_possible_bits); |
| 663 | EXPORT_SYMBOL(cpu_possible_mask); |
| 664 | |
| 665 | static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly; |
| 666 | const struct cpumask *const cpu_online_mask = to_cpumask(cpu_online_bits); |
| 667 | EXPORT_SYMBOL(cpu_online_mask); |
| 668 | |
| 669 | static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly; |
| 670 | const struct cpumask *const cpu_present_mask = to_cpumask(cpu_present_bits); |
| 671 | EXPORT_SYMBOL(cpu_present_mask); |
| 672 | |
| 673 | static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly; |
| 674 | const struct cpumask *const cpu_active_mask = to_cpumask(cpu_active_bits); |
| 675 | EXPORT_SYMBOL(cpu_active_mask); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 676 | |
| 677 | void set_cpu_possible(unsigned int cpu, bool possible) |
| 678 | { |
| 679 | if (possible) |
| 680 | cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits)); |
| 681 | else |
| 682 | cpumask_clear_cpu(cpu, to_cpumask(cpu_possible_bits)); |
| 683 | } |
| 684 | |
| 685 | void set_cpu_present(unsigned int cpu, bool present) |
| 686 | { |
| 687 | if (present) |
| 688 | cpumask_set_cpu(cpu, to_cpumask(cpu_present_bits)); |
| 689 | else |
| 690 | cpumask_clear_cpu(cpu, to_cpumask(cpu_present_bits)); |
| 691 | } |
| 692 | |
| 693 | void set_cpu_online(unsigned int cpu, bool online) |
| 694 | { |
| 695 | if (online) |
| 696 | cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits)); |
| 697 | else |
| 698 | cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits)); |
| 699 | } |
| 700 | |
| 701 | void set_cpu_active(unsigned int cpu, bool active) |
| 702 | { |
| 703 | if (active) |
| 704 | cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits)); |
| 705 | else |
| 706 | cpumask_clear_cpu(cpu, to_cpumask(cpu_active_bits)); |
| 707 | } |
| 708 | |
| 709 | void init_cpu_present(const struct cpumask *src) |
| 710 | { |
| 711 | cpumask_copy(to_cpumask(cpu_present_bits), src); |
| 712 | } |
| 713 | |
| 714 | void init_cpu_possible(const struct cpumask *src) |
| 715 | { |
| 716 | cpumask_copy(to_cpumask(cpu_possible_bits), src); |
| 717 | } |
| 718 | |
| 719 | void init_cpu_online(const struct cpumask *src) |
| 720 | { |
| 721 | cpumask_copy(to_cpumask(cpu_online_bits), src); |
| 722 | } |