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> |
Paul Gortmaker | 9984de1 | 2011-05-23 14:51:41 -0400 | [diff] [blame] | 13 | #include <linux/export.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | #include <linux/kthread.h> |
| 15 | #include <linux/stop_machine.h> |
Ingo Molnar | 81615b6 | 2006-06-26 00:24:32 -0700 | [diff] [blame] | 16 | #include <linux/mutex.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 17 | #include <linux/gfp.h> |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 18 | #include <linux/suspend.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 20 | #include "smpboot.h" |
| 21 | |
Rusty Russell | 98a79d6 | 2008-12-13 21:19:41 +1030 | [diff] [blame] | 22 | #ifdef CONFIG_SMP |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 23 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 24 | static DEFINE_MUTEX(cpu_add_remove_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 26 | /* |
| 27 | * The following two API's must be used when attempting |
| 28 | * to serialize the updates to cpu_online_mask, cpu_present_mask. |
| 29 | */ |
| 30 | void cpu_maps_update_begin(void) |
| 31 | { |
| 32 | mutex_lock(&cpu_add_remove_lock); |
| 33 | } |
| 34 | |
| 35 | void cpu_maps_update_done(void) |
| 36 | { |
| 37 | mutex_unlock(&cpu_add_remove_lock); |
| 38 | } |
| 39 | |
Daniel J Blueman | 5c113fb | 2010-06-01 12:15:11 +0100 | [diff] [blame] | 40 | static RAW_NOTIFIER_HEAD(cpu_chain); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 42 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
| 43 | * Should always be manipulated under cpu_add_remove_lock |
| 44 | */ |
| 45 | static int cpu_hotplug_disabled; |
| 46 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 47 | #ifdef CONFIG_HOTPLUG_CPU |
| 48 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 49 | static struct { |
| 50 | struct task_struct *active_writer; |
| 51 | struct mutex lock; /* Synchronizes accesses to refcount, */ |
| 52 | /* |
| 53 | * Also blocks the new readers during |
| 54 | * an ongoing cpu hotplug operation. |
| 55 | */ |
| 56 | int refcount; |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 57 | } cpu_hotplug = { |
| 58 | .active_writer = NULL, |
| 59 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), |
| 60 | .refcount = 0, |
| 61 | }; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 62 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 63 | void get_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 64 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 65 | might_sleep(); |
| 66 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 67 | return; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 68 | mutex_lock(&cpu_hotplug.lock); |
| 69 | cpu_hotplug.refcount++; |
| 70 | mutex_unlock(&cpu_hotplug.lock); |
| 71 | |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 72 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 73 | EXPORT_SYMBOL_GPL(get_online_cpus); |
Ashok Raj | 90d45d1 | 2005-11-08 21:34:24 -0800 | [diff] [blame] | 74 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 75 | void put_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 76 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 77 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 78 | return; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 79 | mutex_lock(&cpu_hotplug.lock); |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 80 | if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer)) |
| 81 | wake_up_process(cpu_hotplug.active_writer); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 82 | mutex_unlock(&cpu_hotplug.lock); |
| 83 | |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 84 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 85 | EXPORT_SYMBOL_GPL(put_online_cpus); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 86 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 87 | /* |
| 88 | * This ensures that the hotplug operation can begin only when the |
| 89 | * refcount goes to zero. |
| 90 | * |
| 91 | * Note that during a cpu-hotplug operation, the new readers, if any, |
| 92 | * will be blocked by the cpu_hotplug.lock |
| 93 | * |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 94 | * Since cpu_hotplug_begin() is always called after invoking |
| 95 | * 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] | 96 | * |
| 97 | * Note that theoretically, there is a possibility of a livelock: |
| 98 | * - Refcount goes to zero, last reader wakes up the sleeping |
| 99 | * writer. |
| 100 | * - Last reader unlocks the cpu_hotplug.lock. |
| 101 | * - A new reader arrives at this moment, bumps up the refcount. |
| 102 | * - The writer acquires the cpu_hotplug.lock finds the refcount |
| 103 | * non zero and goes to sleep again. |
| 104 | * |
| 105 | * However, this is very difficult to achieve in practice since |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 106 | * 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] | 107 | * |
| 108 | */ |
| 109 | static void cpu_hotplug_begin(void) |
| 110 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 111 | cpu_hotplug.active_writer = current; |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 112 | |
| 113 | for (;;) { |
| 114 | mutex_lock(&cpu_hotplug.lock); |
| 115 | if (likely(!cpu_hotplug.refcount)) |
| 116 | break; |
| 117 | __set_current_state(TASK_UNINTERRUPTIBLE); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 118 | mutex_unlock(&cpu_hotplug.lock); |
| 119 | schedule(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 120 | } |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 121 | } |
| 122 | |
| 123 | static void cpu_hotplug_done(void) |
| 124 | { |
| 125 | cpu_hotplug.active_writer = NULL; |
| 126 | mutex_unlock(&cpu_hotplug.lock); |
| 127 | } |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 128 | |
| 129 | #else /* #if CONFIG_HOTPLUG_CPU */ |
| 130 | static void cpu_hotplug_begin(void) {} |
| 131 | static void cpu_hotplug_done(void) {} |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 132 | #endif /* #else #if CONFIG_HOTPLUG_CPU */ |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 133 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | /* Need to know about CPUs going up/down? */ |
Sam Ravnborg | f7b16c1 | 2008-04-29 00:58:51 -0700 | [diff] [blame] | 135 | int __ref register_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | { |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 137 | int ret; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 138 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 139 | ret = raw_notifier_chain_register(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 140 | cpu_maps_update_done(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 141 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | } |
Chandra Seetharaman | 65edc68 | 2006-06-27 02:54:08 -0700 | [diff] [blame] | 143 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 144 | static int __cpu_notify(unsigned long val, void *v, int nr_to_call, |
| 145 | int *nr_calls) |
| 146 | { |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 147 | int ret; |
| 148 | |
| 149 | ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call, |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 150 | nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 151 | |
| 152 | return notifier_to_errno(ret); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 153 | } |
| 154 | |
| 155 | static int cpu_notify(unsigned long val, void *v) |
| 156 | { |
| 157 | return __cpu_notify(val, v, -1, NULL); |
| 158 | } |
| 159 | |
Linus Torvalds | 00b9b0a | 2010-05-27 10:32:08 -0700 | [diff] [blame] | 160 | #ifdef CONFIG_HOTPLUG_CPU |
| 161 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 162 | static void cpu_notify_nofail(unsigned long val, void *v) |
| 163 | { |
Linus Torvalds | 00b9b0a | 2010-05-27 10:32:08 -0700 | [diff] [blame] | 164 | BUG_ON(cpu_notify(val, v)); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 165 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | EXPORT_SYMBOL(register_cpu_notifier); |
| 167 | |
Sam Ravnborg | 9647155 | 2008-04-29 00:58:48 -0700 | [diff] [blame] | 168 | void __ref unregister_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 170 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 171 | raw_notifier_chain_unregister(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 172 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | } |
| 174 | EXPORT_SYMBOL(unregister_cpu_notifier); |
| 175 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | static inline void check_for_tasks(int cpu) |
| 177 | { |
| 178 | struct task_struct *p; |
| 179 | |
| 180 | write_lock_irq(&tasklist_lock); |
| 181 | for_each_process(p) { |
Peter Zijlstra | 1185424 | 2010-01-21 16:34:27 +0100 | [diff] [blame] | 182 | if (task_cpu(p) == cpu && p->state == TASK_RUNNING && |
Martin Schwidefsky | 6486163 | 2011-12-15 14:56:09 +0100 | [diff] [blame] | 183 | (p->utime || p->stime)) |
Frans Pop | 9d3cfc4 | 2010-01-25 14:56:34 +0100 | [diff] [blame] | 184 | printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d " |
| 185 | "(state = %ld, flags = %x)\n", |
| 186 | p->comm, task_pid_nr(p), cpu, |
| 187 | p->state, p->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | } |
| 189 | write_unlock_irq(&tasklist_lock); |
| 190 | } |
| 191 | |
Avi Kivity | db912f9 | 2007-05-24 12:23:10 +0300 | [diff] [blame] | 192 | struct take_cpu_down_param { |
| 193 | unsigned long mod; |
| 194 | void *hcpu; |
| 195 | }; |
| 196 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | /* Take this CPU down. */ |
Sam Ravnborg | 514a20a | 2008-04-29 00:58:50 -0700 | [diff] [blame] | 198 | static int __ref take_cpu_down(void *_param) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | { |
Avi Kivity | db912f9 | 2007-05-24 12:23:10 +0300 | [diff] [blame] | 200 | struct take_cpu_down_param *param = _param; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | int err; |
| 202 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | /* Ensure this CPU doesn't handle any more interrupts. */ |
| 204 | err = __cpu_disable(); |
| 205 | if (err < 0) |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 206 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 208 | cpu_notify(CPU_DYING | param->mod, param->hcpu); |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 209 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | } |
| 211 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 212 | /* Requires cpu_add_remove_lock to be held */ |
Sam Ravnborg | 514a20a | 2008-04-29 00:58:50 -0700 | [diff] [blame] | 213 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | { |
Heiko Carstens | e7407dc | 2007-05-09 02:34:04 -0700 | [diff] [blame] | 215 | int err, nr_calls = 0; |
Heiko Carstens | e7407dc | 2007-05-09 02:34:04 -0700 | [diff] [blame] | 216 | void *hcpu = (void *)(long)cpu; |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 217 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; |
Avi Kivity | db912f9 | 2007-05-24 12:23:10 +0300 | [diff] [blame] | 218 | struct take_cpu_down_param tcd_param = { |
| 219 | .mod = mod, |
| 220 | .hcpu = hcpu, |
| 221 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 223 | if (num_online_cpus() == 1) |
| 224 | return -EBUSY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 226 | if (!cpu_online(cpu)) |
| 227 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 229 | cpu_hotplug_begin(); |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 230 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 231 | err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 232 | if (err) { |
Akinobu Mita | a0d8cdb | 2007-10-18 03:05:12 -0700 | [diff] [blame] | 233 | nr_calls--; |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 234 | __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | printk("%s: attempt to take down CPU %u failed\n", |
Harvey Harrison | af1f16d | 2008-04-30 00:55:08 -0700 | [diff] [blame] | 236 | __func__, cpu); |
Gautham R Shenoy | baaca49 | 2007-05-09 02:34:03 -0700 | [diff] [blame] | 237 | goto out_release; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | } |
| 239 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 240 | err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 241 | if (err) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | /* CPU didn't die: tell everyone. Can't complain. */ |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 243 | cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | |
Oleg Nesterov | 6a1bdc1 | 2010-03-15 10:10:23 +0100 | [diff] [blame] | 245 | goto out_release; |
Satoru Takeuchi | 8fa1d7d | 2006-10-28 10:38:57 -0700 | [diff] [blame] | 246 | } |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 247 | BUG_ON(cpu_online(cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 249 | /* |
| 250 | * The migration_call() CPU_DYING callback will have removed all |
| 251 | * runnable tasks from the cpu, there's only the idle task left now |
| 252 | * that the migration thread is done doing the stop_machine thing. |
Peter Zijlstra | 51a96c7 | 2010-11-19 20:37:53 +0100 | [diff] [blame] | 253 | * |
| 254 | * Wait for the stop thread to go away. |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 255 | */ |
Peter Zijlstra | 51a96c7 | 2010-11-19 20:37:53 +0100 | [diff] [blame] | 256 | while (!idle_cpu(cpu)) |
| 257 | cpu_relax(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | |
| 259 | /* This actually kills the CPU. */ |
| 260 | __cpu_die(cpu); |
| 261 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | /* CPU is completely dead: tell everyone. Too late to complain. */ |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 263 | cpu_notify_nofail(CPU_DEAD | mod, hcpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | |
| 265 | check_for_tasks(cpu); |
| 266 | |
Gautham R Shenoy | baaca49 | 2007-05-09 02:34:03 -0700 | [diff] [blame] | 267 | out_release: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 268 | cpu_hotplug_done(); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 269 | if (!err) |
| 270 | cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 271 | return err; |
| 272 | } |
| 273 | |
Sam Ravnborg | 514a20a | 2008-04-29 00:58:50 -0700 | [diff] [blame] | 274 | int __ref cpu_down(unsigned int cpu) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 275 | { |
Heiko Carstens | 9ea09af | 2008-12-22 12:36:30 +0100 | [diff] [blame] | 276 | int err; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 277 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 278 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 279 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 280 | if (cpu_hotplug_disabled) { |
| 281 | err = -EBUSY; |
| 282 | goto out; |
| 283 | } |
| 284 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 285 | err = _cpu_down(cpu, 0); |
| 286 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 287 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 288 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | return err; |
| 290 | } |
Zhang Rui | b62b8ef | 2008-04-29 02:35:56 -0400 | [diff] [blame] | 291 | EXPORT_SYMBOL(cpu_down); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | #endif /*CONFIG_HOTPLUG_CPU*/ |
| 293 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 294 | /* Requires cpu_add_remove_lock to be held */ |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 295 | static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | { |
Gautham R Shenoy | baaca49 | 2007-05-09 02:34:03 -0700 | [diff] [blame] | 297 | int ret, nr_calls = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | void *hcpu = (void *)(long)cpu; |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 299 | unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame^] | 300 | struct task_struct *idle; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 302 | if (cpu_online(cpu) || !cpu_present(cpu)) |
| 303 | return -EINVAL; |
Ashok Raj | 90d45d1 | 2005-11-08 21:34:24 -0800 | [diff] [blame] | 304 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 305 | cpu_hotplug_begin(); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 306 | |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame^] | 307 | idle = idle_thread_get(cpu); |
| 308 | if (IS_ERR(idle)) { |
| 309 | ret = PTR_ERR(idle); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 310 | goto out; |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame^] | 311 | } |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 312 | |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 313 | ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 314 | if (ret) { |
Akinobu Mita | a0d8cdb | 2007-10-18 03:05:12 -0700 | [diff] [blame] | 315 | nr_calls--; |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 316 | printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", |
Harvey Harrison | af1f16d | 2008-04-30 00:55:08 -0700 | [diff] [blame] | 317 | __func__, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | goto out_notify; |
| 319 | } |
| 320 | |
| 321 | /* Arch-specific enabling code. */ |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame^] | 322 | ret = __cpu_up(cpu, idle); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | if (ret != 0) |
| 324 | goto out_notify; |
Eric Sesterhenn | 6978c70 | 2006-03-24 18:45:21 +0100 | [diff] [blame] | 325 | BUG_ON(!cpu_online(cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | |
| 327 | /* Now call notifier in preparation. */ |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 328 | cpu_notify(CPU_ONLINE | mod, hcpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | |
| 330 | out_notify: |
| 331 | if (ret != 0) |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 332 | __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 333 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 334 | cpu_hotplug_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 335 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 336 | return ret; |
| 337 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 338 | |
Gautham R Shenoy | b282b6f | 2007-01-10 23:15:34 -0800 | [diff] [blame] | 339 | int __cpuinit cpu_up(unsigned int cpu) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 340 | { |
| 341 | int err = 0; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 342 | |
| 343 | #ifdef CONFIG_MEMORY_HOTPLUG |
| 344 | int nid; |
| 345 | pg_data_t *pgdat; |
| 346 | #endif |
| 347 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 348 | if (!cpu_possible(cpu)) { |
KAMEZAWA Hiroyuki | 73e753a | 2007-10-18 23:40:47 -0700 | [diff] [blame] | 349 | printk(KERN_ERR "can't online cpu %d because it is not " |
| 350 | "configured as may-hotadd at boot time\n", cpu); |
Chen Gong | 87d5e02 | 2010-03-05 13:42:38 -0800 | [diff] [blame] | 351 | #if defined(CONFIG_IA64) |
KAMEZAWA Hiroyuki | 73e753a | 2007-10-18 23:40:47 -0700 | [diff] [blame] | 352 | printk(KERN_ERR "please check additional_cpus= boot " |
| 353 | "parameter\n"); |
| 354 | #endif |
| 355 | return -EINVAL; |
| 356 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 357 | |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 358 | #ifdef CONFIG_MEMORY_HOTPLUG |
| 359 | nid = cpu_to_node(cpu); |
| 360 | if (!node_online(nid)) { |
| 361 | err = mem_online_node(nid); |
| 362 | if (err) |
| 363 | return err; |
| 364 | } |
| 365 | |
| 366 | pgdat = NODE_DATA(nid); |
| 367 | if (!pgdat) { |
| 368 | printk(KERN_ERR |
| 369 | "Can't online cpu %d due to NULL pgdat\n", cpu); |
| 370 | return -ENOMEM; |
| 371 | } |
| 372 | |
Haicheng Li | 4eaf3f6 | 2010-05-24 14:32:52 -0700 | [diff] [blame] | 373 | if (pgdat->node_zonelists->_zonerefs->zone == NULL) { |
| 374 | mutex_lock(&zonelists_mutex); |
Haicheng Li | 1f52250 | 2010-05-24 14:32:51 -0700 | [diff] [blame] | 375 | build_all_zonelists(NULL); |
Haicheng Li | 4eaf3f6 | 2010-05-24 14:32:52 -0700 | [diff] [blame] | 376 | mutex_unlock(&zonelists_mutex); |
| 377 | } |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 378 | #endif |
| 379 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 380 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 381 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 382 | if (cpu_hotplug_disabled) { |
| 383 | err = -EBUSY; |
| 384 | goto out; |
| 385 | } |
| 386 | |
| 387 | err = _cpu_up(cpu, 0); |
| 388 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 389 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 390 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 391 | return err; |
| 392 | } |
Paul E. McKenney | a513f6b | 2011-12-11 21:54:45 -0800 | [diff] [blame] | 393 | EXPORT_SYMBOL_GPL(cpu_up); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 394 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 395 | #ifdef CONFIG_PM_SLEEP_SMP |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 396 | static cpumask_var_t frozen_cpus; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 397 | |
Suresh Siddha | 3fb82d5 | 2010-11-23 16:11:40 -0800 | [diff] [blame] | 398 | void __weak arch_disable_nonboot_cpus_begin(void) |
| 399 | { |
| 400 | } |
| 401 | |
| 402 | void __weak arch_disable_nonboot_cpus_end(void) |
| 403 | { |
| 404 | } |
| 405 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 406 | int disable_nonboot_cpus(void) |
| 407 | { |
Rafael J. Wysocki | e9a5f42 | 2010-05-27 22:16:22 +0200 | [diff] [blame] | 408 | int cpu, first_cpu, error = 0; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 409 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 410 | cpu_maps_update_begin(); |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 411 | first_cpu = cpumask_first(cpu_online_mask); |
Xiaotian Feng | 9ee349a | 2009-12-16 18:04:32 +0100 | [diff] [blame] | 412 | /* |
| 413 | * 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] | 414 | * with the userspace trying to use the CPU hotplug at the same time |
| 415 | */ |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 416 | cpumask_clear(frozen_cpus); |
Suresh Siddha | 3fb82d5 | 2010-11-23 16:11:40 -0800 | [diff] [blame] | 417 | arch_disable_nonboot_cpus_begin(); |
Peter Zijlstra | 6ad4c18 | 2009-11-25 13:31:39 +0100 | [diff] [blame] | 418 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 419 | printk("Disabling non-boot CPUs ...\n"); |
| 420 | for_each_online_cpu(cpu) { |
| 421 | if (cpu == first_cpu) |
| 422 | continue; |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 423 | error = _cpu_down(cpu, 1); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 424 | if (!error) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 425 | cpumask_set_cpu(cpu, frozen_cpus); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 426 | else { |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 427 | printk(KERN_ERR "Error taking CPU%d down: %d\n", |
| 428 | cpu, error); |
| 429 | break; |
| 430 | } |
| 431 | } |
Joseph Cihula | 86886e5 | 2009-06-30 19:31:07 -0700 | [diff] [blame] | 432 | |
Suresh Siddha | 3fb82d5 | 2010-11-23 16:11:40 -0800 | [diff] [blame] | 433 | arch_disable_nonboot_cpus_end(); |
| 434 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 435 | if (!error) { |
| 436 | BUG_ON(num_online_cpus() > 1); |
| 437 | /* Make sure the CPUs won't be enabled by someone else */ |
| 438 | cpu_hotplug_disabled = 1; |
| 439 | } else { |
Ingo Molnar | e1d9fd2 | 2006-12-23 16:55:29 +0100 | [diff] [blame] | 440 | printk(KERN_ERR "Non-boot CPUs are not disabled\n"); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 441 | } |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 442 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 443 | return error; |
| 444 | } |
| 445 | |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 446 | void __weak arch_enable_nonboot_cpus_begin(void) |
| 447 | { |
| 448 | } |
| 449 | |
| 450 | void __weak arch_enable_nonboot_cpus_end(void) |
| 451 | { |
| 452 | } |
| 453 | |
Sam Ravnborg | fa7303e | 2008-02-08 04:21:55 -0800 | [diff] [blame] | 454 | void __ref enable_nonboot_cpus(void) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 455 | { |
| 456 | int cpu, error; |
| 457 | |
| 458 | /* Allow everyone to use the CPU hotplug again */ |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 459 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 460 | cpu_hotplug_disabled = 0; |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 461 | if (cpumask_empty(frozen_cpus)) |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 462 | goto out; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 463 | |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 464 | printk(KERN_INFO "Enabling non-boot CPUs ...\n"); |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 465 | |
| 466 | arch_enable_nonboot_cpus_begin(); |
| 467 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 468 | for_each_cpu(cpu, frozen_cpus) { |
Rafael J. Wysocki | 8bb7844 | 2007-05-09 02:35:10 -0700 | [diff] [blame] | 469 | error = _cpu_up(cpu, 1); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 470 | if (!error) { |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 471 | printk(KERN_INFO "CPU%d is up\n", cpu); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 472 | continue; |
| 473 | } |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 474 | 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] | 475 | } |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 476 | |
| 477 | arch_enable_nonboot_cpus_end(); |
| 478 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 479 | cpumask_clear(frozen_cpus); |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 480 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 481 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 482 | } |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 483 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 484 | static int __init alloc_frozen_cpus(void) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 485 | { |
| 486 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) |
| 487 | return -ENOMEM; |
| 488 | return 0; |
| 489 | } |
| 490 | core_initcall(alloc_frozen_cpus); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 491 | |
| 492 | /* |
| 493 | * Prevent regular CPU hotplug from racing with the freezer, by disabling CPU |
| 494 | * hotplug when tasks are about to be frozen. Also, don't allow the freezer |
| 495 | * to continue until any currently running CPU hotplug operation gets |
| 496 | * completed. |
| 497 | * To modify the 'cpu_hotplug_disabled' flag, we need to acquire the |
| 498 | * 'cpu_add_remove_lock'. And this same lock is also taken by the regular |
| 499 | * CPU hotplug path and released only after it is complete. Thus, we |
| 500 | * (and hence the freezer) will block here until any currently running CPU |
| 501 | * hotplug operation gets completed. |
| 502 | */ |
| 503 | void cpu_hotplug_disable_before_freeze(void) |
| 504 | { |
| 505 | cpu_maps_update_begin(); |
| 506 | cpu_hotplug_disabled = 1; |
| 507 | cpu_maps_update_done(); |
| 508 | } |
| 509 | |
| 510 | |
| 511 | /* |
| 512 | * When tasks have been thawed, re-enable regular CPU hotplug (which had been |
| 513 | * disabled while beginning to freeze tasks). |
| 514 | */ |
| 515 | void cpu_hotplug_enable_after_thaw(void) |
| 516 | { |
| 517 | cpu_maps_update_begin(); |
| 518 | cpu_hotplug_disabled = 0; |
| 519 | cpu_maps_update_done(); |
| 520 | } |
| 521 | |
| 522 | /* |
| 523 | * When callbacks for CPU hotplug notifications are being executed, we must |
| 524 | * ensure that the state of the system with respect to the tasks being frozen |
| 525 | * or not, as reported by the notification, remains unchanged *throughout the |
| 526 | * duration* of the execution of the callbacks. |
| 527 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. |
| 528 | * |
| 529 | * This synchronization is implemented by mutually excluding regular CPU |
| 530 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ |
| 531 | * Hibernate notifications. |
| 532 | */ |
| 533 | static int |
| 534 | cpu_hotplug_pm_callback(struct notifier_block *nb, |
| 535 | unsigned long action, void *ptr) |
| 536 | { |
| 537 | switch (action) { |
| 538 | |
| 539 | case PM_SUSPEND_PREPARE: |
| 540 | case PM_HIBERNATION_PREPARE: |
| 541 | cpu_hotplug_disable_before_freeze(); |
| 542 | break; |
| 543 | |
| 544 | case PM_POST_SUSPEND: |
| 545 | case PM_POST_HIBERNATION: |
| 546 | cpu_hotplug_enable_after_thaw(); |
| 547 | break; |
| 548 | |
| 549 | default: |
| 550 | return NOTIFY_DONE; |
| 551 | } |
| 552 | |
| 553 | return NOTIFY_OK; |
| 554 | } |
| 555 | |
| 556 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 557 | static int __init cpu_hotplug_pm_sync_init(void) |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 558 | { |
| 559 | pm_notifier(cpu_hotplug_pm_callback, 0); |
| 560 | return 0; |
| 561 | } |
| 562 | core_initcall(cpu_hotplug_pm_sync_init); |
| 563 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 564 | #endif /* CONFIG_PM_SLEEP_SMP */ |
Max Krasnyansky | 68f4f1e | 2008-05-29 11:17:02 -0700 | [diff] [blame] | 565 | |
Manfred Spraul | e545a61 | 2008-09-07 16:57:22 +0200 | [diff] [blame] | 566 | /** |
| 567 | * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers |
| 568 | * @cpu: cpu that just started |
| 569 | * |
| 570 | * This function calls the cpu_chain notifiers with CPU_STARTING. |
| 571 | * It must be called by the arch code on the new cpu, before the new cpu |
| 572 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). |
| 573 | */ |
Al Viro | 8419641 | 2008-11-22 17:36:44 +0000 | [diff] [blame] | 574 | void __cpuinit notify_cpu_starting(unsigned int cpu) |
Manfred Spraul | e545a61 | 2008-09-07 16:57:22 +0200 | [diff] [blame] | 575 | { |
| 576 | unsigned long val = CPU_STARTING; |
| 577 | |
| 578 | #ifdef CONFIG_PM_SLEEP_SMP |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 579 | if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus)) |
Manfred Spraul | e545a61 | 2008-09-07 16:57:22 +0200 | [diff] [blame] | 580 | val = CPU_STARTING_FROZEN; |
| 581 | #endif /* CONFIG_PM_SLEEP_SMP */ |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 582 | cpu_notify(val, (void *)(long)cpu); |
Manfred Spraul | e545a61 | 2008-09-07 16:57:22 +0200 | [diff] [blame] | 583 | } |
| 584 | |
Max Krasnyansky | 68f4f1e | 2008-05-29 11:17:02 -0700 | [diff] [blame] | 585 | #endif /* CONFIG_SMP */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 586 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 587 | /* |
| 588 | * cpu_bit_bitmap[] is a special, "compressed" data structure that |
| 589 | * represents all NR_CPUS bits binary values of 1<<nr. |
| 590 | * |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 591 | * 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] | 592 | * mask value that has a single bit set only. |
| 593 | */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 594 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 595 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 596 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 597 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) |
| 598 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) |
| 599 | #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] | 600 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 601 | 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] | 602 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 603 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), |
| 604 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), |
| 605 | #if BITS_PER_LONG > 32 |
| 606 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), |
| 607 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 608 | #endif |
| 609 | }; |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 610 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 611 | |
| 612 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; |
| 613 | EXPORT_SYMBOL(cpu_all_bits); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 614 | |
| 615 | #ifdef CONFIG_INIT_ALL_POSSIBLE |
| 616 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly |
| 617 | = CPU_BITS_ALL; |
| 618 | #else |
| 619 | static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly; |
| 620 | #endif |
| 621 | const struct cpumask *const cpu_possible_mask = to_cpumask(cpu_possible_bits); |
| 622 | EXPORT_SYMBOL(cpu_possible_mask); |
| 623 | |
| 624 | static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly; |
| 625 | const struct cpumask *const cpu_online_mask = to_cpumask(cpu_online_bits); |
| 626 | EXPORT_SYMBOL(cpu_online_mask); |
| 627 | |
| 628 | static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly; |
| 629 | const struct cpumask *const cpu_present_mask = to_cpumask(cpu_present_bits); |
| 630 | EXPORT_SYMBOL(cpu_present_mask); |
| 631 | |
| 632 | static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly; |
| 633 | const struct cpumask *const cpu_active_mask = to_cpumask(cpu_active_bits); |
| 634 | EXPORT_SYMBOL(cpu_active_mask); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 635 | |
| 636 | void set_cpu_possible(unsigned int cpu, bool possible) |
| 637 | { |
| 638 | if (possible) |
| 639 | cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits)); |
| 640 | else |
| 641 | cpumask_clear_cpu(cpu, to_cpumask(cpu_possible_bits)); |
| 642 | } |
| 643 | |
| 644 | void set_cpu_present(unsigned int cpu, bool present) |
| 645 | { |
| 646 | if (present) |
| 647 | cpumask_set_cpu(cpu, to_cpumask(cpu_present_bits)); |
| 648 | else |
| 649 | cpumask_clear_cpu(cpu, to_cpumask(cpu_present_bits)); |
| 650 | } |
| 651 | |
| 652 | void set_cpu_online(unsigned int cpu, bool online) |
| 653 | { |
| 654 | if (online) |
| 655 | cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits)); |
| 656 | else |
| 657 | cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits)); |
| 658 | } |
| 659 | |
| 660 | void set_cpu_active(unsigned int cpu, bool active) |
| 661 | { |
| 662 | if (active) |
| 663 | cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits)); |
| 664 | else |
| 665 | cpumask_clear_cpu(cpu, to_cpumask(cpu_active_bits)); |
| 666 | } |
| 667 | |
| 668 | void init_cpu_present(const struct cpumask *src) |
| 669 | { |
| 670 | cpumask_copy(to_cpumask(cpu_present_bits), src); |
| 671 | } |
| 672 | |
| 673 | void init_cpu_possible(const struct cpumask *src) |
| 674 | { |
| 675 | cpumask_copy(to_cpumask(cpu_possible_bits), src); |
| 676 | } |
| 677 | |
| 678 | void init_cpu_online(const struct cpumask *src) |
| 679 | { |
| 680 | cpumask_copy(to_cpumask(cpu_online_bits), src); |
| 681 | } |