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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <linux/kthread.h> |
| 17 | #include <linux/stop_machine.h> |
Ingo Molnar | 81615b6 | 2006-06-26 00:24:32 -0700 | [diff] [blame] | 18 | #include <linux/mutex.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 19 | #include <linux/gfp.h> |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 20 | #include <linux/suspend.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 22 | #include "smpboot.h" |
| 23 | |
Rusty Russell | 98a79d6 | 2008-12-13 21:19:41 +1030 | [diff] [blame] | 24 | #ifdef CONFIG_SMP |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 25 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 26 | static DEFINE_MUTEX(cpu_add_remove_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 28 | /* |
| 29 | * The following two API's must be used when attempting |
| 30 | * to serialize the updates to cpu_online_mask, cpu_present_mask. |
| 31 | */ |
| 32 | void cpu_maps_update_begin(void) |
| 33 | { |
| 34 | mutex_lock(&cpu_add_remove_lock); |
| 35 | } |
| 36 | |
| 37 | void cpu_maps_update_done(void) |
| 38 | { |
| 39 | mutex_unlock(&cpu_add_remove_lock); |
| 40 | } |
| 41 | |
Daniel J Blueman | 5c113fb | 2010-06-01 12:15:11 +0100 | [diff] [blame] | 42 | static RAW_NOTIFIER_HEAD(cpu_chain); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 44 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
| 45 | * Should always be manipulated under cpu_add_remove_lock |
| 46 | */ |
| 47 | static int cpu_hotplug_disabled; |
| 48 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 49 | #ifdef CONFIG_HOTPLUG_CPU |
| 50 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 51 | static struct { |
| 52 | struct task_struct *active_writer; |
| 53 | struct mutex lock; /* Synchronizes accesses to refcount, */ |
| 54 | /* |
| 55 | * Also blocks the new readers during |
| 56 | * an ongoing cpu hotplug operation. |
| 57 | */ |
| 58 | int refcount; |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 59 | } cpu_hotplug = { |
| 60 | .active_writer = NULL, |
| 61 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), |
| 62 | .refcount = 0, |
| 63 | }; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 64 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 65 | void get_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 66 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 67 | might_sleep(); |
| 68 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 69 | return; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 70 | mutex_lock(&cpu_hotplug.lock); |
| 71 | cpu_hotplug.refcount++; |
| 72 | mutex_unlock(&cpu_hotplug.lock); |
| 73 | |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 74 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 75 | EXPORT_SYMBOL_GPL(get_online_cpus); |
Ashok Raj | 90d45d1 | 2005-11-08 21:34:24 -0800 | [diff] [blame] | 76 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 77 | void put_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 78 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 79 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 80 | return; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 81 | mutex_lock(&cpu_hotplug.lock); |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 82 | if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer)) |
| 83 | wake_up_process(cpu_hotplug.active_writer); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 84 | mutex_unlock(&cpu_hotplug.lock); |
| 85 | |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 86 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 87 | EXPORT_SYMBOL_GPL(put_online_cpus); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 88 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 89 | /* |
| 90 | * This ensures that the hotplug operation can begin only when the |
| 91 | * refcount goes to zero. |
| 92 | * |
| 93 | * Note that during a cpu-hotplug operation, the new readers, if any, |
| 94 | * will be blocked by the cpu_hotplug.lock |
| 95 | * |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 96 | * Since cpu_hotplug_begin() is always called after invoking |
| 97 | * 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] | 98 | * |
| 99 | * Note that theoretically, there is a possibility of a livelock: |
| 100 | * - Refcount goes to zero, last reader wakes up the sleeping |
| 101 | * writer. |
| 102 | * - Last reader unlocks the cpu_hotplug.lock. |
| 103 | * - A new reader arrives at this moment, bumps up the refcount. |
| 104 | * - The writer acquires the cpu_hotplug.lock finds the refcount |
| 105 | * non zero and goes to sleep again. |
| 106 | * |
| 107 | * However, this is very difficult to achieve in practice since |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 108 | * 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] | 109 | * |
| 110 | */ |
| 111 | static void cpu_hotplug_begin(void) |
| 112 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 113 | cpu_hotplug.active_writer = current; |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 114 | |
| 115 | for (;;) { |
| 116 | mutex_lock(&cpu_hotplug.lock); |
| 117 | if (likely(!cpu_hotplug.refcount)) |
| 118 | break; |
| 119 | __set_current_state(TASK_UNINTERRUPTIBLE); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 120 | mutex_unlock(&cpu_hotplug.lock); |
| 121 | schedule(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 122 | } |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 123 | } |
| 124 | |
| 125 | static void cpu_hotplug_done(void) |
| 126 | { |
| 127 | cpu_hotplug.active_writer = NULL; |
| 128 | mutex_unlock(&cpu_hotplug.lock); |
| 129 | } |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 130 | |
| 131 | #else /* #if CONFIG_HOTPLUG_CPU */ |
| 132 | static void cpu_hotplug_begin(void) {} |
| 133 | static void cpu_hotplug_done(void) {} |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 134 | #endif /* #else #if CONFIG_HOTPLUG_CPU */ |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 135 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | /* Need to know about CPUs going up/down? */ |
Sam Ravnborg | f7b16c1 | 2008-04-29 00:58:51 -0700 | [diff] [blame] | 137 | int __ref register_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | { |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 139 | int ret; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 140 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 141 | ret = raw_notifier_chain_register(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 142 | cpu_maps_update_done(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 143 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | } |
Chandra Seetharaman | 65edc68 | 2006-06-27 02:54:08 -0700 | [diff] [blame] | 145 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 146 | static int __cpu_notify(unsigned long val, void *v, int nr_to_call, |
| 147 | int *nr_calls) |
| 148 | { |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 149 | int ret; |
| 150 | |
| 151 | ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call, |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 152 | nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 153 | |
| 154 | return notifier_to_errno(ret); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 155 | } |
| 156 | |
| 157 | static int cpu_notify(unsigned long val, void *v) |
| 158 | { |
| 159 | return __cpu_notify(val, v, -1, NULL); |
| 160 | } |
| 161 | |
Linus Torvalds | 00b9b0a | 2010-05-27 10:32:08 -0700 | [diff] [blame] | 162 | #ifdef CONFIG_HOTPLUG_CPU |
| 163 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 164 | static void cpu_notify_nofail(unsigned long val, void *v) |
| 165 | { |
Linus Torvalds | 00b9b0a | 2010-05-27 10:32:08 -0700 | [diff] [blame] | 166 | BUG_ON(cpu_notify(val, v)); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 167 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | EXPORT_SYMBOL(register_cpu_notifier); |
| 169 | |
Sam Ravnborg | 9647155 | 2008-04-29 00:58:48 -0700 | [diff] [blame] | 170 | void __ref unregister_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 172 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 173 | raw_notifier_chain_unregister(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 174 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | } |
| 176 | EXPORT_SYMBOL(unregister_cpu_notifier); |
| 177 | |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame^] | 178 | void clear_tasks_mm_cpumask(int cpu) |
| 179 | { |
| 180 | struct task_struct *p; |
| 181 | |
| 182 | /* |
| 183 | * This function is called after the cpu is taken down and marked |
| 184 | * offline, so its not like new tasks will ever get this cpu set in |
| 185 | * their mm mask. -- Peter Zijlstra |
| 186 | * Thus, we may use rcu_read_lock() here, instead of grabbing |
| 187 | * full-fledged tasklist_lock. |
| 188 | */ |
| 189 | rcu_read_lock(); |
| 190 | for_each_process(p) { |
| 191 | struct task_struct *t; |
| 192 | |
| 193 | t = find_lock_task_mm(p); |
| 194 | if (!t) |
| 195 | continue; |
| 196 | cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); |
| 197 | task_unlock(t); |
| 198 | } |
| 199 | rcu_read_unlock(); |
| 200 | } |
| 201 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | static inline void check_for_tasks(int cpu) |
| 203 | { |
| 204 | struct task_struct *p; |
| 205 | |
| 206 | write_lock_irq(&tasklist_lock); |
| 207 | for_each_process(p) { |
Peter Zijlstra | 1185424 | 2010-01-21 16:34:27 +0100 | [diff] [blame] | 208 | if (task_cpu(p) == cpu && p->state == TASK_RUNNING && |
Martin Schwidefsky | 6486163 | 2011-12-15 14:56:09 +0100 | [diff] [blame] | 209 | (p->utime || p->stime)) |
Frans Pop | 9d3cfc4 | 2010-01-25 14:56:34 +0100 | [diff] [blame] | 210 | printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d " |
| 211 | "(state = %ld, flags = %x)\n", |
| 212 | p->comm, task_pid_nr(p), cpu, |
| 213 | p->state, p->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | } |
| 215 | write_unlock_irq(&tasklist_lock); |
| 216 | } |
| 217 | |
Avi Kivity | db912f9 | 2007-05-24 12:23:10 +0300 | [diff] [blame] | 218 | struct take_cpu_down_param { |
| 219 | unsigned long mod; |
| 220 | void *hcpu; |
| 221 | }; |
| 222 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | /* Take this CPU down. */ |
Sam Ravnborg | 514a20a | 2008-04-29 00:58:50 -0700 | [diff] [blame] | 224 | static int __ref take_cpu_down(void *_param) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | { |
Avi Kivity | db912f9 | 2007-05-24 12:23:10 +0300 | [diff] [blame] | 226 | struct take_cpu_down_param *param = _param; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | int err; |
| 228 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | /* Ensure this CPU doesn't handle any more interrupts. */ |
| 230 | err = __cpu_disable(); |
| 231 | if (err < 0) |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 232 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 234 | cpu_notify(CPU_DYING | param->mod, param->hcpu); |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 235 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | } |
| 237 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 238 | /* Requires cpu_add_remove_lock to be held */ |
Sam Ravnborg | 514a20a | 2008-04-29 00:58:50 -0700 | [diff] [blame] | 239 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | { |
Heiko Carstens | e7407dc | 2007-05-09 02:34:04 -0700 | [diff] [blame] | 241 | int err, nr_calls = 0; |
Heiko Carstens | e7407dc | 2007-05-09 02:34:04 -0700 | [diff] [blame] | 242 | void *hcpu = (void *)(long)cpu; |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 243 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; |
Avi Kivity | db912f9 | 2007-05-24 12:23:10 +0300 | [diff] [blame] | 244 | struct take_cpu_down_param tcd_param = { |
| 245 | .mod = mod, |
| 246 | .hcpu = hcpu, |
| 247 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 249 | if (num_online_cpus() == 1) |
| 250 | return -EBUSY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 252 | if (!cpu_online(cpu)) |
| 253 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 255 | cpu_hotplug_begin(); |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 256 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 257 | err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 258 | if (err) { |
Akinobu Mita | a0d8cdb | 2007-10-18 03:05:12 -0700 | [diff] [blame] | 259 | nr_calls--; |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 260 | __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | printk("%s: attempt to take down CPU %u failed\n", |
Harvey Harrison | af1f16d | 2008-04-30 00:55:08 -0700 | [diff] [blame] | 262 | __func__, cpu); |
Gautham R Shenoy | baaca49 | 2007-05-09 02:34:03 -0700 | [diff] [blame] | 263 | goto out_release; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | } |
| 265 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 266 | err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 267 | if (err) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | /* CPU didn't die: tell everyone. Can't complain. */ |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 269 | cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | |
Oleg Nesterov | 6a1bdc1 | 2010-03-15 10:10:23 +0100 | [diff] [blame] | 271 | goto out_release; |
Satoru Takeuchi | 8fa1d7d | 2006-10-28 10:38:57 -0700 | [diff] [blame] | 272 | } |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 273 | BUG_ON(cpu_online(cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 275 | /* |
| 276 | * The migration_call() CPU_DYING callback will have removed all |
| 277 | * runnable tasks from the cpu, there's only the idle task left now |
| 278 | * that the migration thread is done doing the stop_machine thing. |
Peter Zijlstra | 51a96c7 | 2010-11-19 20:37:53 +0100 | [diff] [blame] | 279 | * |
| 280 | * Wait for the stop thread to go away. |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 281 | */ |
Peter Zijlstra | 51a96c7 | 2010-11-19 20:37:53 +0100 | [diff] [blame] | 282 | while (!idle_cpu(cpu)) |
| 283 | cpu_relax(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | |
| 285 | /* This actually kills the CPU. */ |
| 286 | __cpu_die(cpu); |
| 287 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | /* CPU is completely dead: tell everyone. Too late to complain. */ |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 289 | cpu_notify_nofail(CPU_DEAD | mod, hcpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | |
| 291 | check_for_tasks(cpu); |
| 292 | |
Gautham R Shenoy | baaca49 | 2007-05-09 02:34:03 -0700 | [diff] [blame] | 293 | out_release: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 294 | cpu_hotplug_done(); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 295 | if (!err) |
| 296 | cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 297 | return err; |
| 298 | } |
| 299 | |
Sam Ravnborg | 514a20a | 2008-04-29 00:58:50 -0700 | [diff] [blame] | 300 | int __ref cpu_down(unsigned int cpu) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 301 | { |
Heiko Carstens | 9ea09af | 2008-12-22 12:36:30 +0100 | [diff] [blame] | 302 | int err; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 303 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 304 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 305 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 306 | if (cpu_hotplug_disabled) { |
| 307 | err = -EBUSY; |
| 308 | goto out; |
| 309 | } |
| 310 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 311 | err = _cpu_down(cpu, 0); |
| 312 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 313 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 314 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | return err; |
| 316 | } |
Zhang Rui | b62b8ef | 2008-04-29 02:35:56 -0400 | [diff] [blame] | 317 | EXPORT_SYMBOL(cpu_down); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | #endif /*CONFIG_HOTPLUG_CPU*/ |
| 319 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 320 | /* Requires cpu_add_remove_lock to be held */ |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 321 | static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 322 | { |
Gautham R Shenoy | baaca49 | 2007-05-09 02:34:03 -0700 | [diff] [blame] | 323 | int ret, nr_calls = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 324 | void *hcpu = (void *)(long)cpu; |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 325 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 326 | struct task_struct *idle; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 328 | if (cpu_online(cpu) || !cpu_present(cpu)) |
| 329 | return -EINVAL; |
Ashok Raj | 90d45d1 | 2005-11-08 21:34:24 -0800 | [diff] [blame] | 330 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 331 | cpu_hotplug_begin(); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 332 | |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 333 | idle = idle_thread_get(cpu); |
| 334 | if (IS_ERR(idle)) { |
| 335 | ret = PTR_ERR(idle); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 336 | goto out; |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 337 | } |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 338 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 339 | ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 340 | if (ret) { |
Akinobu Mita | a0d8cdb | 2007-10-18 03:05:12 -0700 | [diff] [blame] | 341 | nr_calls--; |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 342 | printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", |
Harvey Harrison | af1f16d | 2008-04-30 00:55:08 -0700 | [diff] [blame] | 343 | __func__, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | goto out_notify; |
| 345 | } |
| 346 | |
| 347 | /* Arch-specific enabling code. */ |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 348 | ret = __cpu_up(cpu, idle); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | if (ret != 0) |
| 350 | goto out_notify; |
Eric Sesterhenn | 6978c70 | 2006-03-24 18:45:21 +0100 | [diff] [blame] | 351 | BUG_ON(!cpu_online(cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | |
| 353 | /* Now call notifier in preparation. */ |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 354 | cpu_notify(CPU_ONLINE | mod, hcpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 355 | |
| 356 | out_notify: |
| 357 | if (ret != 0) |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 358 | __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 359 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 360 | cpu_hotplug_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 361 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 362 | return ret; |
| 363 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 364 | |
Gautham R Shenoy | b282b6f | 2007-01-10 23:15:34 -0800 | [diff] [blame] | 365 | int __cpuinit cpu_up(unsigned int cpu) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 366 | { |
| 367 | int err = 0; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 368 | |
| 369 | #ifdef CONFIG_MEMORY_HOTPLUG |
| 370 | int nid; |
| 371 | pg_data_t *pgdat; |
| 372 | #endif |
| 373 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 374 | if (!cpu_possible(cpu)) { |
KAMEZAWA Hiroyuki | 73e753a | 2007-10-18 23:40:47 -0700 | [diff] [blame] | 375 | printk(KERN_ERR "can't online cpu %d because it is not " |
| 376 | "configured as may-hotadd at boot time\n", cpu); |
Chen Gong | 87d5e02 | 2010-03-05 13:42:38 -0800 | [diff] [blame] | 377 | #if defined(CONFIG_IA64) |
KAMEZAWA Hiroyuki | 73e753a | 2007-10-18 23:40:47 -0700 | [diff] [blame] | 378 | printk(KERN_ERR "please check additional_cpus= boot " |
| 379 | "parameter\n"); |
| 380 | #endif |
| 381 | return -EINVAL; |
| 382 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 383 | |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 384 | #ifdef CONFIG_MEMORY_HOTPLUG |
| 385 | nid = cpu_to_node(cpu); |
| 386 | if (!node_online(nid)) { |
| 387 | err = mem_online_node(nid); |
| 388 | if (err) |
| 389 | return err; |
| 390 | } |
| 391 | |
| 392 | pgdat = NODE_DATA(nid); |
| 393 | if (!pgdat) { |
| 394 | printk(KERN_ERR |
| 395 | "Can't online cpu %d due to NULL pgdat\n", cpu); |
| 396 | return -ENOMEM; |
| 397 | } |
| 398 | |
Haicheng Li | 4eaf3f6 | 2010-05-24 14:32:52 -0700 | [diff] [blame] | 399 | if (pgdat->node_zonelists->_zonerefs->zone == NULL) { |
| 400 | mutex_lock(&zonelists_mutex); |
Haicheng Li | 1f52250 | 2010-05-24 14:32:51 -0700 | [diff] [blame] | 401 | build_all_zonelists(NULL); |
Haicheng Li | 4eaf3f6 | 2010-05-24 14:32:52 -0700 | [diff] [blame] | 402 | mutex_unlock(&zonelists_mutex); |
| 403 | } |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 404 | #endif |
| 405 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 406 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 407 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 408 | if (cpu_hotplug_disabled) { |
| 409 | err = -EBUSY; |
| 410 | goto out; |
| 411 | } |
| 412 | |
| 413 | err = _cpu_up(cpu, 0); |
| 414 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 415 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 416 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 417 | return err; |
| 418 | } |
Paul E. McKenney | a513f6b | 2011-12-11 21:54:45 -0800 | [diff] [blame] | 419 | EXPORT_SYMBOL_GPL(cpu_up); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 420 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 421 | #ifdef CONFIG_PM_SLEEP_SMP |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 422 | static cpumask_var_t frozen_cpus; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 423 | |
Suresh Siddha | 3fb82d5 | 2010-11-23 16:11:40 -0800 | [diff] [blame] | 424 | void __weak arch_disable_nonboot_cpus_begin(void) |
| 425 | { |
| 426 | } |
| 427 | |
| 428 | void __weak arch_disable_nonboot_cpus_end(void) |
| 429 | { |
| 430 | } |
| 431 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 432 | int disable_nonboot_cpus(void) |
| 433 | { |
Rafael J. Wysocki | e9a5f42 | 2010-05-27 22:16:22 +0200 | [diff] [blame] | 434 | int cpu, first_cpu, error = 0; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 435 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 436 | cpu_maps_update_begin(); |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 437 | first_cpu = cpumask_first(cpu_online_mask); |
Xiaotian Feng | 9ee349a | 2009-12-16 18:04:32 +0100 | [diff] [blame] | 438 | /* |
| 439 | * 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] | 440 | * with the userspace trying to use the CPU hotplug at the same time |
| 441 | */ |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 442 | cpumask_clear(frozen_cpus); |
Suresh Siddha | 3fb82d5 | 2010-11-23 16:11:40 -0800 | [diff] [blame] | 443 | arch_disable_nonboot_cpus_begin(); |
Peter Zijlstra | 6ad4c18 | 2009-11-25 13:31:39 +0100 | [diff] [blame] | 444 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 445 | printk("Disabling non-boot CPUs ...\n"); |
| 446 | for_each_online_cpu(cpu) { |
| 447 | if (cpu == first_cpu) |
| 448 | continue; |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 449 | error = _cpu_down(cpu, 1); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 450 | if (!error) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 451 | cpumask_set_cpu(cpu, frozen_cpus); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 452 | else { |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 453 | printk(KERN_ERR "Error taking CPU%d down: %d\n", |
| 454 | cpu, error); |
| 455 | break; |
| 456 | } |
| 457 | } |
Joseph Cihula | 86886e5 | 2009-06-30 19:31:07 -0700 | [diff] [blame] | 458 | |
Suresh Siddha | 3fb82d5 | 2010-11-23 16:11:40 -0800 | [diff] [blame] | 459 | arch_disable_nonboot_cpus_end(); |
| 460 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 461 | if (!error) { |
| 462 | BUG_ON(num_online_cpus() > 1); |
| 463 | /* Make sure the CPUs won't be enabled by someone else */ |
| 464 | cpu_hotplug_disabled = 1; |
| 465 | } else { |
Ingo Molnar | e1d9fd2 | 2006-12-23 16:55:29 +0100 | [diff] [blame] | 466 | printk(KERN_ERR "Non-boot CPUs are not disabled\n"); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 467 | } |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 468 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 469 | return error; |
| 470 | } |
| 471 | |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 472 | void __weak arch_enable_nonboot_cpus_begin(void) |
| 473 | { |
| 474 | } |
| 475 | |
| 476 | void __weak arch_enable_nonboot_cpus_end(void) |
| 477 | { |
| 478 | } |
| 479 | |
Sam Ravnborg | fa7303e | 2008-02-08 04:21:55 -0800 | [diff] [blame] | 480 | void __ref enable_nonboot_cpus(void) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 481 | { |
| 482 | int cpu, error; |
| 483 | |
| 484 | /* Allow everyone to use the CPU hotplug again */ |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 485 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 486 | cpu_hotplug_disabled = 0; |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 487 | if (cpumask_empty(frozen_cpus)) |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 488 | goto out; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 489 | |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 490 | printk(KERN_INFO "Enabling non-boot CPUs ...\n"); |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 491 | |
| 492 | arch_enable_nonboot_cpus_begin(); |
| 493 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 494 | for_each_cpu(cpu, frozen_cpus) { |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 495 | error = _cpu_up(cpu, 1); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 496 | if (!error) { |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 497 | printk(KERN_INFO "CPU%d is up\n", cpu); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 498 | continue; |
| 499 | } |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 500 | 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] | 501 | } |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 502 | |
| 503 | arch_enable_nonboot_cpus_end(); |
| 504 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 505 | cpumask_clear(frozen_cpus); |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 506 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 507 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 508 | } |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 509 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 510 | static int __init alloc_frozen_cpus(void) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 511 | { |
| 512 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) |
| 513 | return -ENOMEM; |
| 514 | return 0; |
| 515 | } |
| 516 | core_initcall(alloc_frozen_cpus); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 517 | |
| 518 | /* |
| 519 | * Prevent regular CPU hotplug from racing with the freezer, by disabling CPU |
| 520 | * hotplug when tasks are about to be frozen. Also, don't allow the freezer |
| 521 | * to continue until any currently running CPU hotplug operation gets |
| 522 | * completed. |
| 523 | * To modify the 'cpu_hotplug_disabled' flag, we need to acquire the |
| 524 | * 'cpu_add_remove_lock'. And this same lock is also taken by the regular |
| 525 | * CPU hotplug path and released only after it is complete. Thus, we |
| 526 | * (and hence the freezer) will block here until any currently running CPU |
| 527 | * hotplug operation gets completed. |
| 528 | */ |
| 529 | void cpu_hotplug_disable_before_freeze(void) |
| 530 | { |
| 531 | cpu_maps_update_begin(); |
| 532 | cpu_hotplug_disabled = 1; |
| 533 | cpu_maps_update_done(); |
| 534 | } |
| 535 | |
| 536 | |
| 537 | /* |
| 538 | * When tasks have been thawed, re-enable regular CPU hotplug (which had been |
| 539 | * disabled while beginning to freeze tasks). |
| 540 | */ |
| 541 | void cpu_hotplug_enable_after_thaw(void) |
| 542 | { |
| 543 | cpu_maps_update_begin(); |
| 544 | cpu_hotplug_disabled = 0; |
| 545 | cpu_maps_update_done(); |
| 546 | } |
| 547 | |
| 548 | /* |
| 549 | * When callbacks for CPU hotplug notifications are being executed, we must |
| 550 | * ensure that the state of the system with respect to the tasks being frozen |
| 551 | * or not, as reported by the notification, remains unchanged *throughout the |
| 552 | * duration* of the execution of the callbacks. |
| 553 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. |
| 554 | * |
| 555 | * This synchronization is implemented by mutually excluding regular CPU |
| 556 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ |
| 557 | * Hibernate notifications. |
| 558 | */ |
| 559 | static int |
| 560 | cpu_hotplug_pm_callback(struct notifier_block *nb, |
| 561 | unsigned long action, void *ptr) |
| 562 | { |
| 563 | switch (action) { |
| 564 | |
| 565 | case PM_SUSPEND_PREPARE: |
| 566 | case PM_HIBERNATION_PREPARE: |
| 567 | cpu_hotplug_disable_before_freeze(); |
| 568 | break; |
| 569 | |
| 570 | case PM_POST_SUSPEND: |
| 571 | case PM_POST_HIBERNATION: |
| 572 | cpu_hotplug_enable_after_thaw(); |
| 573 | break; |
| 574 | |
| 575 | default: |
| 576 | return NOTIFY_DONE; |
| 577 | } |
| 578 | |
| 579 | return NOTIFY_OK; |
| 580 | } |
| 581 | |
| 582 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 583 | static int __init cpu_hotplug_pm_sync_init(void) |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 584 | { |
| 585 | pm_notifier(cpu_hotplug_pm_callback, 0); |
| 586 | return 0; |
| 587 | } |
| 588 | core_initcall(cpu_hotplug_pm_sync_init); |
| 589 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 590 | #endif /* CONFIG_PM_SLEEP_SMP */ |
Max Krasnyansky | 68f4f1e | 2008-05-29 11:17:02 -0700 | [diff] [blame] | 591 | |
Manfred Spraul | e545a61 | 2008-09-07 16:57:22 +0200 | [diff] [blame] | 592 | /** |
| 593 | * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers |
| 594 | * @cpu: cpu that just started |
| 595 | * |
| 596 | * This function calls the cpu_chain notifiers with CPU_STARTING. |
| 597 | * It must be called by the arch code on the new cpu, before the new cpu |
| 598 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). |
| 599 | */ |
Al Viro | 8419641 | 2008-11-22 17:36:44 +0000 | [diff] [blame] | 600 | void __cpuinit notify_cpu_starting(unsigned int cpu) |
Manfred Spraul | e545a61 | 2008-09-07 16:57:22 +0200 | [diff] [blame] | 601 | { |
| 602 | unsigned long val = CPU_STARTING; |
| 603 | |
| 604 | #ifdef CONFIG_PM_SLEEP_SMP |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 605 | if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus)) |
Manfred Spraul | e545a61 | 2008-09-07 16:57:22 +0200 | [diff] [blame] | 606 | val = CPU_STARTING_FROZEN; |
| 607 | #endif /* CONFIG_PM_SLEEP_SMP */ |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 608 | cpu_notify(val, (void *)(long)cpu); |
Manfred Spraul | e545a61 | 2008-09-07 16:57:22 +0200 | [diff] [blame] | 609 | } |
| 610 | |
Max Krasnyansky | 68f4f1e | 2008-05-29 11:17:02 -0700 | [diff] [blame] | 611 | #endif /* CONFIG_SMP */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 612 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 613 | /* |
| 614 | * cpu_bit_bitmap[] is a special, "compressed" data structure that |
| 615 | * represents all NR_CPUS bits binary values of 1<<nr. |
| 616 | * |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 617 | * 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] | 618 | * mask value that has a single bit set only. |
| 619 | */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 620 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 621 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 622 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 623 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) |
| 624 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) |
| 625 | #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] | 626 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 627 | 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] | 628 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 629 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), |
| 630 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), |
| 631 | #if BITS_PER_LONG > 32 |
| 632 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), |
| 633 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 634 | #endif |
| 635 | }; |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 636 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 637 | |
| 638 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; |
| 639 | EXPORT_SYMBOL(cpu_all_bits); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 640 | |
| 641 | #ifdef CONFIG_INIT_ALL_POSSIBLE |
| 642 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly |
| 643 | = CPU_BITS_ALL; |
| 644 | #else |
| 645 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly; |
| 646 | #endif |
| 647 | const struct cpumask *const cpu_possible_mask = to_cpumask(cpu_possible_bits); |
| 648 | EXPORT_SYMBOL(cpu_possible_mask); |
| 649 | |
| 650 | static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly; |
| 651 | const struct cpumask *const cpu_online_mask = to_cpumask(cpu_online_bits); |
| 652 | EXPORT_SYMBOL(cpu_online_mask); |
| 653 | |
| 654 | static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly; |
| 655 | const struct cpumask *const cpu_present_mask = to_cpumask(cpu_present_bits); |
| 656 | EXPORT_SYMBOL(cpu_present_mask); |
| 657 | |
| 658 | static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly; |
| 659 | const struct cpumask *const cpu_active_mask = to_cpumask(cpu_active_bits); |
| 660 | EXPORT_SYMBOL(cpu_active_mask); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 661 | |
| 662 | void set_cpu_possible(unsigned int cpu, bool possible) |
| 663 | { |
| 664 | if (possible) |
| 665 | cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits)); |
| 666 | else |
| 667 | cpumask_clear_cpu(cpu, to_cpumask(cpu_possible_bits)); |
| 668 | } |
| 669 | |
| 670 | void set_cpu_present(unsigned int cpu, bool present) |
| 671 | { |
| 672 | if (present) |
| 673 | cpumask_set_cpu(cpu, to_cpumask(cpu_present_bits)); |
| 674 | else |
| 675 | cpumask_clear_cpu(cpu, to_cpumask(cpu_present_bits)); |
| 676 | } |
| 677 | |
| 678 | void set_cpu_online(unsigned int cpu, bool online) |
| 679 | { |
| 680 | if (online) |
| 681 | cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits)); |
| 682 | else |
| 683 | cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits)); |
| 684 | } |
| 685 | |
| 686 | void set_cpu_active(unsigned int cpu, bool active) |
| 687 | { |
| 688 | if (active) |
| 689 | cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits)); |
| 690 | else |
| 691 | cpumask_clear_cpu(cpu, to_cpumask(cpu_active_bits)); |
| 692 | } |
| 693 | |
| 694 | void init_cpu_present(const struct cpumask *src) |
| 695 | { |
| 696 | cpumask_copy(to_cpumask(cpu_present_bits), src); |
| 697 | } |
| 698 | |
| 699 | void init_cpu_possible(const struct cpumask *src) |
| 700 | { |
| 701 | cpumask_copy(to_cpumask(cpu_possible_bits), src); |
| 702 | } |
| 703 | |
| 704 | void init_cpu_online(const struct cpumask *src) |
| 705 | { |
| 706 | cpumask_copy(to_cpumask(cpu_online_bits), src); |
| 707 | } |