Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* CPU control. |
| 2 | * (C) 2001, 2002, 2003, 2004 Rusty Russell |
| 3 | * |
| 4 | * This code is licenced under the GPL. |
| 5 | */ |
| 6 | #include <linux/proc_fs.h> |
| 7 | #include <linux/smp.h> |
| 8 | #include <linux/init.h> |
| 9 | #include <linux/notifier.h> |
| 10 | #include <linux/sched.h> |
| 11 | #include <linux/unistd.h> |
| 12 | #include <linux/cpu.h> |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 13 | #include <linux/oom.h> |
| 14 | #include <linux/rcupdate.h> |
Paul Gortmaker | 9984de1 | 2011-05-23 14:51:41 -0400 | [diff] [blame] | 15 | #include <linux/export.h> |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 16 | #include <linux/bug.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/kthread.h> |
| 18 | #include <linux/stop_machine.h> |
Ingo Molnar | 81615b6 | 2006-06-26 00:24:32 -0700 | [diff] [blame] | 19 | #include <linux/mutex.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 20 | #include <linux/gfp.h> |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 21 | #include <linux/suspend.h> |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 22 | #include <linux/lockdep.h> |
Preeti U Murthy | 345527b | 2015-03-30 14:59:19 +0530 | [diff] [blame] | 23 | #include <linux/tick.h> |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 24 | #include <linux/irq.h> |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 25 | #include <linux/smpboot.h> |
Richard Weinberger | e6d4989 | 2016-08-18 14:57:17 +0200 | [diff] [blame] | 26 | #include <linux/relay.h> |
Sebastian Andrzej Siewior | 6731d4f | 2016-08-23 14:53:19 +0200 | [diff] [blame] | 27 | #include <linux/slab.h> |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 28 | |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 29 | #include <trace/events/power.h> |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 30 | #define CREATE_TRACE_POINTS |
| 31 | #include <trace/events/cpuhp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 33 | #include "smpboot.h" |
| 34 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 35 | /** |
| 36 | * cpuhp_cpu_state - Per cpu hotplug state storage |
| 37 | * @state: The current cpu state |
| 38 | * @target: The target state |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 39 | * @thread: Pointer to the hotplug thread |
| 40 | * @should_run: Thread should execute |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 41 | * @rollback: Perform a rollback |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 42 | * @single: Single callback invocation |
| 43 | * @bringup: Single callback bringup or teardown selector |
| 44 | * @cb_state: The state for a single callback (install/uninstall) |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 45 | * @result: Result of the operation |
| 46 | * @done: Signal completion to the issuer of the task |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 47 | */ |
| 48 | struct cpuhp_cpu_state { |
| 49 | enum cpuhp_state state; |
| 50 | enum cpuhp_state target; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 51 | #ifdef CONFIG_SMP |
| 52 | struct task_struct *thread; |
| 53 | bool should_run; |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 54 | bool rollback; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 55 | bool single; |
| 56 | bool bringup; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 57 | struct hlist_node *node; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 58 | enum cpuhp_state cb_state; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 59 | int result; |
| 60 | struct completion done; |
| 61 | #endif |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 62 | }; |
| 63 | |
| 64 | static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state); |
| 65 | |
| 66 | /** |
| 67 | * cpuhp_step - Hotplug state machine step |
| 68 | * @name: Name of the step |
| 69 | * @startup: Startup function of the step |
| 70 | * @teardown: Teardown function of the step |
| 71 | * @skip_onerr: Do not invoke the functions on error rollback |
| 72 | * Will go away once the notifiers are gone |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 73 | * @cant_stop: Bringup/teardown can't be stopped at this step |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 74 | */ |
| 75 | struct cpuhp_step { |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 76 | const char *name; |
| 77 | union { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 78 | int (*single)(unsigned int cpu); |
| 79 | int (*multi)(unsigned int cpu, |
| 80 | struct hlist_node *node); |
| 81 | } startup; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 82 | union { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 83 | int (*single)(unsigned int cpu); |
| 84 | int (*multi)(unsigned int cpu, |
| 85 | struct hlist_node *node); |
| 86 | } teardown; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 87 | struct hlist_head list; |
| 88 | bool skip_onerr; |
| 89 | bool cant_stop; |
| 90 | bool multi_instance; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 91 | }; |
| 92 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 93 | static DEFINE_MUTEX(cpuhp_state_mutex); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 94 | static struct cpuhp_step cpuhp_bp_states[]; |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 95 | static struct cpuhp_step cpuhp_ap_states[]; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 96 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 97 | static bool cpuhp_is_ap_state(enum cpuhp_state state) |
| 98 | { |
| 99 | /* |
| 100 | * The extra check for CPUHP_TEARDOWN_CPU is only for documentation |
| 101 | * purposes as that state is handled explicitly in cpu_down. |
| 102 | */ |
| 103 | return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU; |
| 104 | } |
| 105 | |
| 106 | static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state) |
| 107 | { |
| 108 | struct cpuhp_step *sp; |
| 109 | |
| 110 | sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states; |
| 111 | return sp + state; |
| 112 | } |
| 113 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 114 | /** |
| 115 | * cpuhp_invoke_callback _ Invoke the callbacks for a given state |
| 116 | * @cpu: The cpu for which the callback should be invoked |
| 117 | * @step: The step in the state machine |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 118 | * @bringup: True if the bringup callback should be invoked |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 119 | * |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 120 | * Called from cpu hotplug and from the state register machinery. |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 121 | */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 122 | static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state, |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 123 | bool bringup, struct hlist_node *node) |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 124 | { |
| 125 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 126 | struct cpuhp_step *step = cpuhp_get_step(state); |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 127 | int (*cbm)(unsigned int cpu, struct hlist_node *node); |
| 128 | int (*cb)(unsigned int cpu); |
| 129 | int ret, cnt; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 130 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 131 | if (!step->multi_instance) { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 132 | cb = bringup ? step->startup.single : step->teardown.single; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 133 | if (!cb) |
| 134 | return 0; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 135 | trace_cpuhp_enter(cpu, st->target, state, cb); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 136 | ret = cb(cpu); |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 137 | trace_cpuhp_exit(cpu, st->state, state, ret); |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 138 | return ret; |
| 139 | } |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 140 | cbm = bringup ? step->startup.multi : step->teardown.multi; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 141 | if (!cbm) |
| 142 | return 0; |
| 143 | |
| 144 | /* Single invocation for instance add/remove */ |
| 145 | if (node) { |
| 146 | trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node); |
| 147 | ret = cbm(cpu, node); |
| 148 | trace_cpuhp_exit(cpu, st->state, state, ret); |
| 149 | return ret; |
| 150 | } |
| 151 | |
| 152 | /* State transition. Invoke on all instances */ |
| 153 | cnt = 0; |
| 154 | hlist_for_each(node, &step->list) { |
| 155 | trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node); |
| 156 | ret = cbm(cpu, node); |
| 157 | trace_cpuhp_exit(cpu, st->state, state, ret); |
| 158 | if (ret) |
| 159 | goto err; |
| 160 | cnt++; |
| 161 | } |
| 162 | return 0; |
| 163 | err: |
| 164 | /* Rollback the instances if one failed */ |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 165 | cbm = !bringup ? step->startup.multi : step->teardown.multi; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 166 | if (!cbm) |
| 167 | return ret; |
| 168 | |
| 169 | hlist_for_each(node, &step->list) { |
| 170 | if (!cnt--) |
| 171 | break; |
| 172 | cbm(cpu, node); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 173 | } |
| 174 | return ret; |
| 175 | } |
| 176 | |
Rusty Russell | 98a79d6 | 2008-12-13 21:19:41 +1030 | [diff] [blame] | 177 | #ifdef CONFIG_SMP |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 178 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 179 | static DEFINE_MUTEX(cpu_add_remove_lock); |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 180 | bool cpuhp_tasks_frozen; |
| 181 | EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 183 | /* |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 184 | * The following two APIs (cpu_maps_update_begin/done) must be used when |
| 185 | * attempting to serialize the updates to cpu_online_mask & cpu_present_mask. |
| 186 | * The APIs cpu_notifier_register_begin/done() must be used to protect CPU |
| 187 | * hotplug callback (un)registration performed using __register_cpu_notifier() |
| 188 | * or __unregister_cpu_notifier(). |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 189 | */ |
| 190 | void cpu_maps_update_begin(void) |
| 191 | { |
| 192 | mutex_lock(&cpu_add_remove_lock); |
| 193 | } |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 194 | EXPORT_SYMBOL(cpu_notifier_register_begin); |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 195 | |
| 196 | void cpu_maps_update_done(void) |
| 197 | { |
| 198 | mutex_unlock(&cpu_add_remove_lock); |
| 199 | } |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 200 | EXPORT_SYMBOL(cpu_notifier_register_done); |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 201 | |
Daniel J Blueman | 5c113fb | 2010-06-01 12:15:11 +0100 | [diff] [blame] | 202 | static RAW_NOTIFIER_HEAD(cpu_chain); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 204 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
| 205 | * Should always be manipulated under cpu_add_remove_lock |
| 206 | */ |
| 207 | static int cpu_hotplug_disabled; |
| 208 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 209 | #ifdef CONFIG_HOTPLUG_CPU |
| 210 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 211 | static struct { |
| 212 | struct task_struct *active_writer; |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 213 | /* wait queue to wake up the active_writer */ |
| 214 | wait_queue_head_t wq; |
| 215 | /* verifies that no writer will get active while readers are active */ |
| 216 | struct mutex lock; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 217 | /* |
| 218 | * Also blocks the new readers during |
| 219 | * an ongoing cpu hotplug operation. |
| 220 | */ |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 221 | atomic_t refcount; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 222 | |
| 223 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| 224 | struct lockdep_map dep_map; |
| 225 | #endif |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 226 | } cpu_hotplug = { |
| 227 | .active_writer = NULL, |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 228 | .wq = __WAIT_QUEUE_HEAD_INITIALIZER(cpu_hotplug.wq), |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 229 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 230 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
Joonas Lahtinen | a705e07 | 2016-10-12 13:18:56 +0300 | [diff] [blame] | 231 | .dep_map = STATIC_LOCKDEP_MAP_INIT("cpu_hotplug.dep_map", &cpu_hotplug.dep_map), |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 232 | #endif |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 233 | }; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 234 | |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 235 | /* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */ |
| 236 | #define cpuhp_lock_acquire_read() lock_map_acquire_read(&cpu_hotplug.dep_map) |
Paul E. McKenney | dd56af4 | 2014-08-25 20:25:06 -0700 | [diff] [blame] | 237 | #define cpuhp_lock_acquire_tryread() \ |
| 238 | lock_map_acquire_tryread(&cpu_hotplug.dep_map) |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 239 | #define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map) |
| 240 | #define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map) |
| 241 | |
Paul E. McKenney | 62db99f | 2014-10-22 14:51:49 -0700 | [diff] [blame] | 242 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 243 | void get_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 244 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 245 | might_sleep(); |
| 246 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 247 | return; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 248 | cpuhp_lock_acquire_read(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 249 | mutex_lock(&cpu_hotplug.lock); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 250 | atomic_inc(&cpu_hotplug.refcount); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 251 | mutex_unlock(&cpu_hotplug.lock); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 252 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 253 | EXPORT_SYMBOL_GPL(get_online_cpus); |
Ashok Raj | 90d45d1 | 2005-11-08 21:34:24 -0800 | [diff] [blame] | 254 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 255 | void put_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 256 | { |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 257 | int refcount; |
| 258 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 259 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 260 | return; |
Srivatsa S. Bhat | 075663d | 2012-10-08 16:28:20 -0700 | [diff] [blame] | 261 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 262 | refcount = atomic_dec_return(&cpu_hotplug.refcount); |
| 263 | if (WARN_ON(refcount < 0)) /* try to fix things up */ |
| 264 | atomic_inc(&cpu_hotplug.refcount); |
Srivatsa S. Bhat | 075663d | 2012-10-08 16:28:20 -0700 | [diff] [blame] | 265 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 266 | if (refcount <= 0 && waitqueue_active(&cpu_hotplug.wq)) |
| 267 | wake_up(&cpu_hotplug.wq); |
| 268 | |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 269 | cpuhp_lock_release(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 270 | |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 271 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 272 | EXPORT_SYMBOL_GPL(put_online_cpus); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 273 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 274 | /* |
| 275 | * This ensures that the hotplug operation can begin only when the |
| 276 | * refcount goes to zero. |
| 277 | * |
| 278 | * Note that during a cpu-hotplug operation, the new readers, if any, |
| 279 | * will be blocked by the cpu_hotplug.lock |
| 280 | * |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 281 | * Since cpu_hotplug_begin() is always called after invoking |
| 282 | * 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] | 283 | * |
| 284 | * Note that theoretically, there is a possibility of a livelock: |
| 285 | * - Refcount goes to zero, last reader wakes up the sleeping |
| 286 | * writer. |
| 287 | * - Last reader unlocks the cpu_hotplug.lock. |
| 288 | * - A new reader arrives at this moment, bumps up the refcount. |
| 289 | * - The writer acquires the cpu_hotplug.lock finds the refcount |
| 290 | * non zero and goes to sleep again. |
| 291 | * |
| 292 | * However, this is very difficult to achieve in practice since |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 293 | * 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] | 294 | * |
| 295 | */ |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 296 | void cpu_hotplug_begin(void) |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 297 | { |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 298 | DEFINE_WAIT(wait); |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 299 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 300 | cpu_hotplug.active_writer = current; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 301 | cpuhp_lock_acquire(); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 302 | |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 303 | for (;;) { |
| 304 | mutex_lock(&cpu_hotplug.lock); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 305 | prepare_to_wait(&cpu_hotplug.wq, &wait, TASK_UNINTERRUPTIBLE); |
| 306 | if (likely(!atomic_read(&cpu_hotplug.refcount))) |
| 307 | break; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 308 | mutex_unlock(&cpu_hotplug.lock); |
| 309 | schedule(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 310 | } |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 311 | finish_wait(&cpu_hotplug.wq, &wait); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 312 | } |
| 313 | |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 314 | void cpu_hotplug_done(void) |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 315 | { |
| 316 | cpu_hotplug.active_writer = NULL; |
| 317 | mutex_unlock(&cpu_hotplug.lock); |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 318 | cpuhp_lock_release(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 319 | } |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 320 | |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 321 | /* |
| 322 | * Wait for currently running CPU hotplug operations to complete (if any) and |
| 323 | * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects |
| 324 | * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the |
| 325 | * hotplug path before performing hotplug operations. So acquiring that lock |
| 326 | * guarantees mutual exclusion from any currently running hotplug operations. |
| 327 | */ |
| 328 | void cpu_hotplug_disable(void) |
| 329 | { |
| 330 | cpu_maps_update_begin(); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 331 | cpu_hotplug_disabled++; |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 332 | cpu_maps_update_done(); |
| 333 | } |
Vitaly Kuznetsov | 32145c4 | 2015-08-05 00:52:47 -0700 | [diff] [blame] | 334 | EXPORT_SYMBOL_GPL(cpu_hotplug_disable); |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 335 | |
Lianwei Wang | 01b4115 | 2016-06-09 23:43:28 -0700 | [diff] [blame] | 336 | static void __cpu_hotplug_enable(void) |
| 337 | { |
| 338 | if (WARN_ONCE(!cpu_hotplug_disabled, "Unbalanced cpu hotplug enable\n")) |
| 339 | return; |
| 340 | cpu_hotplug_disabled--; |
| 341 | } |
| 342 | |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 343 | void cpu_hotplug_enable(void) |
| 344 | { |
| 345 | cpu_maps_update_begin(); |
Lianwei Wang | 01b4115 | 2016-06-09 23:43:28 -0700 | [diff] [blame] | 346 | __cpu_hotplug_enable(); |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 347 | cpu_maps_update_done(); |
| 348 | } |
Vitaly Kuznetsov | 32145c4 | 2015-08-05 00:52:47 -0700 | [diff] [blame] | 349 | EXPORT_SYMBOL_GPL(cpu_hotplug_enable); |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 350 | #endif /* CONFIG_HOTPLUG_CPU */ |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 351 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | /* Need to know about CPUs going up/down? */ |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 353 | int register_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 354 | { |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 355 | int ret; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 356 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 357 | ret = raw_notifier_chain_register(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 358 | cpu_maps_update_done(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 359 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | } |
Chandra Seetharaman | 65edc68 | 2006-06-27 02:54:08 -0700 | [diff] [blame] | 361 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 362 | int __register_cpu_notifier(struct notifier_block *nb) |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 363 | { |
| 364 | return raw_notifier_chain_register(&cpu_chain, nb); |
| 365 | } |
| 366 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 367 | static int __cpu_notify(unsigned long val, unsigned int cpu, int nr_to_call, |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 368 | int *nr_calls) |
| 369 | { |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 370 | unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0; |
| 371 | void *hcpu = (void *)(long)cpu; |
| 372 | |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 373 | int ret; |
| 374 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 375 | ret = __raw_notifier_call_chain(&cpu_chain, val | mod, hcpu, nr_to_call, |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 376 | nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 377 | |
| 378 | return notifier_to_errno(ret); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 379 | } |
| 380 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 381 | static int cpu_notify(unsigned long val, unsigned int cpu) |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 382 | { |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 383 | return __cpu_notify(val, cpu, -1, NULL); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 384 | } |
| 385 | |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 386 | static void cpu_notify_nofail(unsigned long val, unsigned int cpu) |
| 387 | { |
| 388 | BUG_ON(cpu_notify(val, cpu)); |
| 389 | } |
| 390 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 391 | /* Notifier wrappers for transitioning to state machine */ |
| 392 | static int notify_prepare(unsigned int cpu) |
| 393 | { |
| 394 | int nr_calls = 0; |
| 395 | int ret; |
| 396 | |
| 397 | ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls); |
| 398 | if (ret) { |
| 399 | nr_calls--; |
| 400 | printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", |
| 401 | __func__, cpu); |
| 402 | __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL); |
| 403 | } |
| 404 | return ret; |
| 405 | } |
| 406 | |
| 407 | static int notify_online(unsigned int cpu) |
| 408 | { |
| 409 | cpu_notify(CPU_ONLINE, cpu); |
| 410 | return 0; |
| 411 | } |
Thomas Gleixner | ceb354b | 2017-07-04 22:20:23 +0200 | [diff] [blame^] | 412 | static void __cpuhp_kick_ap_work(struct cpuhp_cpu_state *st); |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 413 | |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 414 | static int bringup_wait_for_ap(unsigned int cpu) |
| 415 | { |
| 416 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 417 | |
Thomas Gleixner | ceb354b | 2017-07-04 22:20:23 +0200 | [diff] [blame^] | 418 | /* Wait for the CPU to reach CPUHP_AP_ONLINE_IDLE */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 419 | wait_for_completion(&st->done); |
Thomas Gleixner | ceb354b | 2017-07-04 22:20:23 +0200 | [diff] [blame^] | 420 | BUG_ON(!cpu_online(cpu)); |
| 421 | |
| 422 | /* Unpark the stopper thread and the hotplug thread of the target cpu */ |
| 423 | stop_machine_unpark(cpu); |
| 424 | kthread_unpark(st->thread); |
| 425 | |
| 426 | /* Should we go further up ? */ |
| 427 | if (st->target > CPUHP_AP_ONLINE_IDLE) { |
| 428 | __cpuhp_kick_ap_work(st); |
| 429 | wait_for_completion(&st->done); |
| 430 | } |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 431 | return st->result; |
| 432 | } |
| 433 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 434 | static int bringup_cpu(unsigned int cpu) |
| 435 | { |
| 436 | struct task_struct *idle = idle_thread_get(cpu); |
| 437 | int ret; |
| 438 | |
Boris Ostrovsky | aa87717 | 2016-08-03 13:22:28 -0400 | [diff] [blame] | 439 | /* |
| 440 | * Some architectures have to walk the irq descriptors to |
| 441 | * setup the vector space for the cpu which comes online. |
| 442 | * Prevent irq alloc/free across the bringup. |
| 443 | */ |
| 444 | irq_lock_sparse(); |
| 445 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 446 | /* Arch-specific enabling code. */ |
| 447 | ret = __cpu_up(cpu, idle); |
Boris Ostrovsky | aa87717 | 2016-08-03 13:22:28 -0400 | [diff] [blame] | 448 | irq_unlock_sparse(); |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 449 | if (ret) { |
| 450 | cpu_notify(CPU_UP_CANCELED, cpu); |
| 451 | return ret; |
| 452 | } |
Thomas Gleixner | ceb354b | 2017-07-04 22:20:23 +0200 | [diff] [blame^] | 453 | return bringup_wait_for_ap(cpu); |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 454 | } |
| 455 | |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 456 | /* |
| 457 | * Hotplug state machine related functions |
| 458 | */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 459 | static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st) |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 460 | { |
| 461 | for (st->state++; st->state < st->target; st->state++) { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 462 | struct cpuhp_step *step = cpuhp_get_step(st->state); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 463 | |
| 464 | if (!step->skip_onerr) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 465 | cpuhp_invoke_callback(cpu, st->state, true, NULL); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 466 | } |
| 467 | } |
| 468 | |
| 469 | static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 470 | enum cpuhp_state target) |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 471 | { |
| 472 | enum cpuhp_state prev_state = st->state; |
| 473 | int ret = 0; |
| 474 | |
| 475 | for (; st->state > target; st->state--) { |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 476 | ret = cpuhp_invoke_callback(cpu, st->state, false, NULL); |
Channagoud Kadabi | bd019ce | 2017-06-19 17:14:52 -0700 | [diff] [blame] | 477 | BUG_ON(ret && st->state < CPUHP_AP_IDLE_DEAD); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 478 | if (ret) { |
| 479 | st->target = prev_state; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 480 | undo_cpu_down(cpu, st); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 481 | break; |
| 482 | } |
| 483 | } |
| 484 | return ret; |
| 485 | } |
| 486 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 487 | static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st) |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 488 | { |
| 489 | for (st->state--; st->state > st->target; st->state--) { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 490 | struct cpuhp_step *step = cpuhp_get_step(st->state); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 491 | |
| 492 | if (!step->skip_onerr) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 493 | cpuhp_invoke_callback(cpu, st->state, false, NULL); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 494 | } |
| 495 | } |
| 496 | |
| 497 | static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 498 | enum cpuhp_state target) |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 499 | { |
| 500 | enum cpuhp_state prev_state = st->state; |
| 501 | int ret = 0; |
| 502 | |
| 503 | while (st->state < target) { |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 504 | st->state++; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 505 | ret = cpuhp_invoke_callback(cpu, st->state, true, NULL); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 506 | if (ret) { |
| 507 | st->target = prev_state; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 508 | undo_cpu_up(cpu, st); |
Channagoud Kadabi | 5ec3ec1 | 2017-06-20 15:01:40 -0700 | [diff] [blame] | 509 | cpu_notify(CPU_UP_CANCELED, cpu); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 510 | break; |
| 511 | } |
| 512 | } |
| 513 | return ret; |
| 514 | } |
| 515 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 516 | /* |
| 517 | * The cpu hotplug threads manage the bringup and teardown of the cpus |
| 518 | */ |
| 519 | static void cpuhp_create(unsigned int cpu) |
| 520 | { |
| 521 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 522 | |
| 523 | init_completion(&st->done); |
| 524 | } |
| 525 | |
| 526 | static int cpuhp_should_run(unsigned int cpu) |
| 527 | { |
| 528 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 529 | |
| 530 | return st->should_run; |
| 531 | } |
| 532 | |
| 533 | /* Execute the teardown callbacks. Used to be CPU_DOWN_PREPARE */ |
| 534 | static int cpuhp_ap_offline(unsigned int cpu, struct cpuhp_cpu_state *st) |
| 535 | { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 536 | enum cpuhp_state target = max((int)st->target, CPUHP_TEARDOWN_CPU); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 537 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 538 | return cpuhp_down_callbacks(cpu, st, target); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 539 | } |
| 540 | |
| 541 | /* Execute the online startup callbacks. Used to be CPU_ONLINE */ |
| 542 | static int cpuhp_ap_online(unsigned int cpu, struct cpuhp_cpu_state *st) |
| 543 | { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 544 | return cpuhp_up_callbacks(cpu, st, st->target); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 545 | } |
| 546 | |
| 547 | /* |
| 548 | * Execute teardown/startup callbacks on the plugged cpu. Also used to invoke |
| 549 | * callbacks when a state gets [un]installed at runtime. |
| 550 | */ |
| 551 | static void cpuhp_thread_fun(unsigned int cpu) |
| 552 | { |
| 553 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 554 | int ret = 0; |
| 555 | |
| 556 | /* |
| 557 | * Paired with the mb() in cpuhp_kick_ap_work and |
| 558 | * cpuhp_invoke_ap_callback, so the work set is consistent visible. |
| 559 | */ |
| 560 | smp_mb(); |
| 561 | if (!st->should_run) |
| 562 | return; |
| 563 | |
| 564 | st->should_run = false; |
| 565 | |
| 566 | /* Single callback invocation for [un]install ? */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 567 | if (st->single) { |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 568 | if (st->cb_state < CPUHP_AP_ONLINE) { |
| 569 | local_irq_disable(); |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 570 | ret = cpuhp_invoke_callback(cpu, st->cb_state, |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 571 | st->bringup, st->node); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 572 | local_irq_enable(); |
| 573 | } else { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 574 | ret = cpuhp_invoke_callback(cpu, st->cb_state, |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 575 | st->bringup, st->node); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 576 | } |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 577 | } else if (st->rollback) { |
| 578 | BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE); |
| 579 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 580 | undo_cpu_down(cpu, st); |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 581 | /* |
| 582 | * This is a momentary workaround to keep the notifier users |
| 583 | * happy. Will go away once we got rid of the notifiers. |
| 584 | */ |
| 585 | cpu_notify_nofail(CPU_DOWN_FAILED, cpu); |
| 586 | st->rollback = false; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 587 | } else { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 588 | /* Cannot happen .... */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 589 | BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 590 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 591 | /* Regular hotplug work */ |
| 592 | if (st->state < st->target) |
| 593 | ret = cpuhp_ap_online(cpu, st); |
| 594 | else if (st->state > st->target) |
| 595 | ret = cpuhp_ap_offline(cpu, st); |
| 596 | } |
| 597 | st->result = ret; |
| 598 | complete(&st->done); |
| 599 | } |
| 600 | |
| 601 | /* Invoke a single callback on a remote cpu */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 602 | static int |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 603 | cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state, bool bringup, |
| 604 | struct hlist_node *node) |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 605 | { |
| 606 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 607 | |
| 608 | if (!cpu_online(cpu)) |
| 609 | return 0; |
| 610 | |
Thomas Gleixner | 6a4e245 | 2016-07-13 17:16:03 +0000 | [diff] [blame] | 611 | /* |
| 612 | * If we are up and running, use the hotplug thread. For early calls |
| 613 | * we invoke the thread function directly. |
| 614 | */ |
| 615 | if (!st->thread) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 616 | return cpuhp_invoke_callback(cpu, state, bringup, node); |
Thomas Gleixner | 6a4e245 | 2016-07-13 17:16:03 +0000 | [diff] [blame] | 617 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 618 | st->cb_state = state; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 619 | st->single = true; |
| 620 | st->bringup = bringup; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 621 | st->node = node; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 622 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 623 | /* |
| 624 | * Make sure the above stores are visible before should_run becomes |
| 625 | * true. Paired with the mb() above in cpuhp_thread_fun() |
| 626 | */ |
| 627 | smp_mb(); |
| 628 | st->should_run = true; |
| 629 | wake_up_process(st->thread); |
| 630 | wait_for_completion(&st->done); |
| 631 | return st->result; |
| 632 | } |
| 633 | |
| 634 | /* Regular hotplug invocation of the AP hotplug thread */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 635 | static void __cpuhp_kick_ap_work(struct cpuhp_cpu_state *st) |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 636 | { |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 637 | st->result = 0; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 638 | st->single = false; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 639 | /* |
| 640 | * Make sure the above stores are visible before should_run becomes |
| 641 | * true. Paired with the mb() above in cpuhp_thread_fun() |
| 642 | */ |
| 643 | smp_mb(); |
| 644 | st->should_run = true; |
| 645 | wake_up_process(st->thread); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 646 | } |
| 647 | |
| 648 | static int cpuhp_kick_ap_work(unsigned int cpu) |
| 649 | { |
| 650 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 651 | enum cpuhp_state state = st->state; |
| 652 | |
| 653 | trace_cpuhp_enter(cpu, st->target, state, cpuhp_kick_ap_work); |
| 654 | __cpuhp_kick_ap_work(st); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 655 | wait_for_completion(&st->done); |
| 656 | trace_cpuhp_exit(cpu, st->state, state, st->result); |
| 657 | return st->result; |
| 658 | } |
| 659 | |
| 660 | static struct smp_hotplug_thread cpuhp_threads = { |
| 661 | .store = &cpuhp_state.thread, |
| 662 | .create = &cpuhp_create, |
| 663 | .thread_should_run = cpuhp_should_run, |
| 664 | .thread_fn = cpuhp_thread_fun, |
| 665 | .thread_comm = "cpuhp/%u", |
| 666 | .selfparking = true, |
| 667 | }; |
| 668 | |
| 669 | void __init cpuhp_threads_init(void) |
| 670 | { |
| 671 | BUG_ON(smpboot_register_percpu_thread(&cpuhp_threads)); |
| 672 | kthread_unpark(this_cpu_read(cpuhp_state.thread)); |
| 673 | } |
| 674 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | EXPORT_SYMBOL(register_cpu_notifier); |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 676 | EXPORT_SYMBOL(__register_cpu_notifier); |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 677 | void unregister_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 678 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 679 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 680 | raw_notifier_chain_unregister(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 681 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 682 | } |
| 683 | EXPORT_SYMBOL(unregister_cpu_notifier); |
| 684 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 685 | void __unregister_cpu_notifier(struct notifier_block *nb) |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 686 | { |
| 687 | raw_notifier_chain_unregister(&cpu_chain, nb); |
| 688 | } |
| 689 | EXPORT_SYMBOL(__unregister_cpu_notifier); |
| 690 | |
Michal Hocko | 56eaecc | 2016-12-07 14:54:38 +0100 | [diff] [blame] | 691 | #ifdef CONFIG_HOTPLUG_CPU |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 692 | /** |
| 693 | * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU |
| 694 | * @cpu: a CPU id |
| 695 | * |
| 696 | * This function walks all processes, finds a valid mm struct for each one and |
| 697 | * then clears a corresponding bit in mm's cpumask. While this all sounds |
| 698 | * trivial, there are various non-obvious corner cases, which this function |
| 699 | * tries to solve in a safe manner. |
| 700 | * |
| 701 | * Also note that the function uses a somewhat relaxed locking scheme, so it may |
| 702 | * be called only for an already offlined CPU. |
| 703 | */ |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 704 | void clear_tasks_mm_cpumask(int cpu) |
| 705 | { |
| 706 | struct task_struct *p; |
| 707 | |
| 708 | /* |
| 709 | * This function is called after the cpu is taken down and marked |
| 710 | * offline, so its not like new tasks will ever get this cpu set in |
| 711 | * their mm mask. -- Peter Zijlstra |
| 712 | * Thus, we may use rcu_read_lock() here, instead of grabbing |
| 713 | * full-fledged tasklist_lock. |
| 714 | */ |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 715 | WARN_ON(cpu_online(cpu)); |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 716 | rcu_read_lock(); |
| 717 | for_each_process(p) { |
| 718 | struct task_struct *t; |
| 719 | |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 720 | /* |
| 721 | * Main thread might exit, but other threads may still have |
| 722 | * a valid mm. Find one. |
| 723 | */ |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 724 | t = find_lock_task_mm(p); |
| 725 | if (!t) |
| 726 | continue; |
| 727 | cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); |
| 728 | task_unlock(t); |
| 729 | } |
| 730 | rcu_read_unlock(); |
| 731 | } |
| 732 | |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 733 | static inline void check_for_tasks(int dead_cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 734 | { |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 735 | struct task_struct *g, *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 736 | |
Oleg Nesterov | a75a606 | 2015-09-10 15:07:50 +0200 | [diff] [blame] | 737 | read_lock(&tasklist_lock); |
| 738 | for_each_process_thread(g, p) { |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 739 | if (!p->on_rq) |
| 740 | continue; |
| 741 | /* |
| 742 | * We do the check with unlocked task_rq(p)->lock. |
| 743 | * Order the reading to do not warn about a task, |
| 744 | * which was running on this cpu in the past, and |
| 745 | * it's just been woken on another cpu. |
| 746 | */ |
| 747 | rmb(); |
| 748 | if (task_cpu(p) != dead_cpu) |
| 749 | continue; |
| 750 | |
| 751 | pr_warn("Task %s (pid=%d) is on cpu %d (state=%ld, flags=%x)\n", |
| 752 | p->comm, task_pid_nr(p), dead_cpu, p->state, p->flags); |
Oleg Nesterov | a75a606 | 2015-09-10 15:07:50 +0200 | [diff] [blame] | 753 | } |
| 754 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 755 | } |
| 756 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 757 | static int notify_down_prepare(unsigned int cpu) |
| 758 | { |
| 759 | int err, nr_calls = 0; |
| 760 | |
| 761 | err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls); |
| 762 | if (err) { |
| 763 | nr_calls--; |
| 764 | __cpu_notify(CPU_DOWN_FAILED, cpu, nr_calls, NULL); |
| 765 | pr_warn("%s: attempt to take down CPU %u failed\n", |
| 766 | __func__, cpu); |
| 767 | } |
| 768 | return err; |
| 769 | } |
| 770 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | /* Take this CPU down. */ |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 772 | static int take_cpu_down(void *_param) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | { |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 774 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 775 | enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE); |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 776 | int err, cpu = smp_processor_id(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 777 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | /* Ensure this CPU doesn't handle any more interrupts. */ |
| 779 | err = __cpu_disable(); |
| 780 | if (err < 0) |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 781 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 783 | /* |
| 784 | * We get here while we are in CPUHP_TEARDOWN_CPU state and we must not |
| 785 | * do this step again. |
| 786 | */ |
| 787 | WARN_ON(st->state != CPUHP_TEARDOWN_CPU); |
| 788 | st->state--; |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 789 | /* Invoke the former CPU_DYING callbacks */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 790 | for (; st->state > target; st->state--) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 791 | cpuhp_invoke_callback(cpu, st->state, false, NULL); |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 792 | |
Thomas Gleixner | 52c063d | 2015-04-03 02:37:24 +0200 | [diff] [blame] | 793 | /* Give up timekeeping duties */ |
| 794 | tick_handover_do_timer(); |
Thomas Gleixner | 14e568e | 2013-01-31 12:11:14 +0000 | [diff] [blame] | 795 | /* Park the stopper thread */ |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 796 | stop_machine_park(cpu); |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 797 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | } |
| 799 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 800 | static int takedown_cpu(unsigned int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 801 | { |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 802 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 803 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 804 | |
Thomas Gleixner | 2a58c52 | 2016-03-10 20:42:08 +0100 | [diff] [blame] | 805 | /* Park the smpboot threads */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 806 | kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread); |
Thomas Gleixner | 2a58c52 | 2016-03-10 20:42:08 +0100 | [diff] [blame] | 807 | smpboot_park_threads(cpu); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 808 | |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 809 | /* |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 810 | * Prevent irq alloc/free while the dying cpu reorganizes the |
| 811 | * interrupt affinities. |
| 812 | */ |
| 813 | irq_lock_sparse(); |
| 814 | |
| 815 | /* |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 816 | * So now all preempt/rcu users must observe !cpu_active(). |
| 817 | */ |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 818 | err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu)); |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 819 | if (err) { |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 820 | /* CPU refused to die */ |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 821 | irq_unlock_sparse(); |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 822 | /* Unpark the hotplug thread so we can rollback there */ |
| 823 | kthread_unpark(per_cpu_ptr(&cpuhp_state, cpu)->thread); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 824 | return err; |
Satoru Takeuchi | 8fa1d7d | 2006-10-28 10:38:57 -0700 | [diff] [blame] | 825 | } |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 826 | BUG_ON(cpu_online(cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 828 | /* |
Thomas Gleixner | ee1e714 | 2016-08-18 14:57:16 +0200 | [diff] [blame] | 829 | * The CPUHP_AP_SCHED_MIGRATE_DYING callback will have removed all |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 830 | * runnable tasks from the cpu, there's only the idle task left now |
| 831 | * that the migration thread is done doing the stop_machine thing. |
Peter Zijlstra | 51a96c7 | 2010-11-19 20:37:53 +0100 | [diff] [blame] | 832 | * |
| 833 | * Wait for the stop thread to go away. |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 834 | */ |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 835 | wait_for_completion(&st->done); |
| 836 | BUG_ON(st->state != CPUHP_AP_IDLE_DEAD); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 837 | |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 838 | /* Interrupts are moved away from the dying cpu, reenable alloc/free */ |
| 839 | irq_unlock_sparse(); |
| 840 | |
Preeti U Murthy | 345527b | 2015-03-30 14:59:19 +0530 | [diff] [blame] | 841 | hotplug_cpu__broadcast_tick_pull(cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 842 | /* This actually kills the CPU. */ |
| 843 | __cpu_die(cpu); |
| 844 | |
Thomas Gleixner | a49b116 | 2015-04-03 02:38:05 +0200 | [diff] [blame] | 845 | tick_cleanup_dead_cpu(cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 846 | return 0; |
| 847 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 848 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 849 | static int notify_dead(unsigned int cpu) |
| 850 | { |
| 851 | cpu_notify_nofail(CPU_DEAD, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 852 | check_for_tasks(cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 853 | return 0; |
| 854 | } |
| 855 | |
Thomas Gleixner | 71f87b2 | 2016-03-03 10:52:10 +0100 | [diff] [blame] | 856 | static void cpuhp_complete_idle_dead(void *arg) |
| 857 | { |
| 858 | struct cpuhp_cpu_state *st = arg; |
| 859 | |
| 860 | complete(&st->done); |
| 861 | } |
| 862 | |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 863 | void cpuhp_report_idle_dead(void) |
| 864 | { |
| 865 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 866 | |
| 867 | BUG_ON(st->state != CPUHP_AP_OFFLINE); |
Thomas Gleixner | 27d50c7 | 2016-02-26 18:43:44 +0000 | [diff] [blame] | 868 | rcu_report_dead(smp_processor_id()); |
Thomas Gleixner | 71f87b2 | 2016-03-03 10:52:10 +0100 | [diff] [blame] | 869 | st->state = CPUHP_AP_IDLE_DEAD; |
| 870 | /* |
| 871 | * We cannot call complete after rcu_report_dead() so we delegate it |
| 872 | * to an online cpu. |
| 873 | */ |
| 874 | smp_call_function_single(cpumask_first(cpu_online_mask), |
| 875 | cpuhp_complete_idle_dead, st, 0); |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 876 | } |
| 877 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 878 | #else |
| 879 | #define notify_down_prepare NULL |
| 880 | #define takedown_cpu NULL |
| 881 | #define notify_dead NULL |
| 882 | #endif |
| 883 | |
| 884 | #ifdef CONFIG_HOTPLUG_CPU |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 885 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 886 | /* Requires cpu_add_remove_lock to be held */ |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 887 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, |
| 888 | enum cpuhp_state target) |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 889 | { |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 890 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 891 | int prev_state, ret = 0; |
| 892 | bool hasdied = false; |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 893 | |
| 894 | if (num_online_cpus() == 1) |
| 895 | return -EBUSY; |
| 896 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 897 | if (!cpu_present(cpu)) |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 898 | return -EINVAL; |
| 899 | |
Pavankumar Kondeti | 68435b0 | 2017-06-29 16:17:55 +0530 | [diff] [blame] | 900 | if (!tasks_frozen && !cpu_isolated(cpu) && num_online_uniso_cpus() == 1) |
| 901 | return -EBUSY; |
| 902 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 903 | cpu_hotplug_begin(); |
| 904 | |
| 905 | cpuhp_tasks_frozen = tasks_frozen; |
| 906 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 907 | prev_state = st->state; |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 908 | st->target = target; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 909 | /* |
| 910 | * If the current CPU state is in the range of the AP hotplug thread, |
| 911 | * then we need to kick the thread. |
| 912 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 913 | if (st->state > CPUHP_TEARDOWN_CPU) { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 914 | ret = cpuhp_kick_ap_work(cpu); |
| 915 | /* |
| 916 | * The AP side has done the error rollback already. Just |
| 917 | * return the error code.. |
| 918 | */ |
| 919 | if (ret) |
| 920 | goto out; |
| 921 | |
| 922 | /* |
| 923 | * We might have stopped still in the range of the AP hotplug |
| 924 | * thread. Nothing to do anymore. |
| 925 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 926 | if (st->state > CPUHP_TEARDOWN_CPU) |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 927 | goto out; |
| 928 | } |
| 929 | /* |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 930 | * The AP brought itself down to CPUHP_TEARDOWN_CPU. So we need |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 931 | * to do the further cleanups. |
| 932 | */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 933 | ret = cpuhp_down_callbacks(cpu, st, target); |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 934 | if (ret && st->state > CPUHP_TEARDOWN_CPU && st->state < prev_state) { |
| 935 | st->target = prev_state; |
| 936 | st->rollback = true; |
| 937 | cpuhp_kick_ap_work(cpu); |
| 938 | } |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 939 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 940 | hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 941 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 942 | cpu_hotplug_done(); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 943 | /* This post dead nonsense must die */ |
| 944 | if (!ret && hasdied) |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 945 | cpu_notify_nofail(CPU_POST_DEAD, cpu); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 946 | return ret; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 947 | } |
| 948 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 949 | static int do_cpu_down(unsigned int cpu, enum cpuhp_state target) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 950 | { |
Heiko Carstens | 9ea09af | 2008-12-22 12:36:30 +0100 | [diff] [blame] | 951 | int err; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 952 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 953 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 954 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 955 | if (cpu_hotplug_disabled) { |
| 956 | err = -EBUSY; |
| 957 | goto out; |
| 958 | } |
| 959 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 960 | err = _cpu_down(cpu, 0, target); |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 961 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 962 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 963 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 964 | return err; |
| 965 | } |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 966 | int cpu_down(unsigned int cpu) |
| 967 | { |
| 968 | return do_cpu_down(cpu, CPUHP_OFFLINE); |
| 969 | } |
Zhang Rui | b62b8ef | 2008-04-29 02:35:56 -0400 | [diff] [blame] | 970 | EXPORT_SYMBOL(cpu_down); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 971 | #endif /*CONFIG_HOTPLUG_CPU*/ |
| 972 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 973 | /** |
Thomas Gleixner | ee1e714 | 2016-08-18 14:57:16 +0200 | [diff] [blame] | 974 | * notify_cpu_starting(cpu) - Invoke the callbacks on the starting CPU |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 975 | * @cpu: cpu that just started |
| 976 | * |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 977 | * It must be called by the arch code on the new cpu, before the new cpu |
| 978 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). |
| 979 | */ |
| 980 | void notify_cpu_starting(unsigned int cpu) |
| 981 | { |
| 982 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 983 | enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE); |
| 984 | |
Sebastian Andrzej Siewior | 0c6d457 | 2016-08-17 14:21:04 +0200 | [diff] [blame] | 985 | rcu_cpu_starting(cpu); /* Enables RCU usage on this CPU. */ |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 986 | while (st->state < target) { |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 987 | st->state++; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 988 | cpuhp_invoke_callback(cpu, st->state, true, NULL); |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 989 | } |
| 990 | } |
| 991 | |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 992 | /* |
Thomas Gleixner | ceb354b | 2017-07-04 22:20:23 +0200 | [diff] [blame^] | 993 | * Called from the idle task. Wake up the controlling task which brings the |
| 994 | * stopper and the hotplug thread of the upcoming CPU up and then delegates |
| 995 | * the rest of the online bringup to the hotplug thread. |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 996 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 997 | void cpuhp_online_idle(enum cpuhp_state state) |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 998 | { |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 999 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 1000 | |
| 1001 | /* Happens for the boot cpu */ |
| 1002 | if (state != CPUHP_AP_ONLINE_IDLE) |
| 1003 | return; |
| 1004 | |
| 1005 | st->state = CPUHP_AP_ONLINE_IDLE; |
Thomas Gleixner | ceb354b | 2017-07-04 22:20:23 +0200 | [diff] [blame^] | 1006 | complete(&st->done); |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 1007 | } |
| 1008 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1009 | /* Requires cpu_add_remove_lock to be held */ |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1010 | static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1011 | { |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1012 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 1013 | struct task_struct *idle; |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 1014 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1015 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1016 | cpu_hotplug_begin(); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 1017 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1018 | if (!cpu_present(cpu)) { |
Yasuaki Ishimatsu | 5e5041f | 2012-10-23 01:30:54 +0200 | [diff] [blame] | 1019 | ret = -EINVAL; |
| 1020 | goto out; |
| 1021 | } |
| 1022 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1023 | /* |
| 1024 | * The caller of do_cpu_up might have raced with another |
| 1025 | * caller. Ignore it for now. |
| 1026 | */ |
| 1027 | if (st->state >= target) |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 1028 | goto out; |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1029 | |
| 1030 | if (st->state == CPUHP_OFFLINE) { |
| 1031 | /* Let it fail before we try to bring the cpu up */ |
| 1032 | idle = idle_thread_get(cpu); |
| 1033 | if (IS_ERR(idle)) { |
| 1034 | ret = PTR_ERR(idle); |
| 1035 | goto out; |
| 1036 | } |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 1037 | } |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 1038 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 1039 | cpuhp_tasks_frozen = tasks_frozen; |
| 1040 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1041 | st->target = target; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1042 | /* |
| 1043 | * If the current CPU state is in the range of the AP hotplug thread, |
| 1044 | * then we need to kick the thread once more. |
| 1045 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 1046 | if (st->state > CPUHP_BRINGUP_CPU) { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1047 | ret = cpuhp_kick_ap_work(cpu); |
| 1048 | /* |
| 1049 | * The AP side has done the error rollback already. Just |
| 1050 | * return the error code.. |
| 1051 | */ |
| 1052 | if (ret) |
| 1053 | goto out; |
| 1054 | } |
| 1055 | |
| 1056 | /* |
| 1057 | * Try to reach the target state. We max out on the BP at |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 1058 | * CPUHP_BRINGUP_CPU. After that the AP hotplug thread is |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1059 | * responsible for bringing it up to the target state. |
| 1060 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 1061 | target = min((int)target, CPUHP_BRINGUP_CPU); |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 1062 | ret = cpuhp_up_callbacks(cpu, st, target); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 1063 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1064 | cpu_hotplug_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1065 | return ret; |
| 1066 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1067 | |
Syed Rameez Mustafa | b305880 | 2016-12-16 11:59:05 -0800 | [diff] [blame] | 1068 | static int switch_to_rt_policy(void) |
| 1069 | { |
| 1070 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; |
| 1071 | unsigned int policy = current->policy; |
| 1072 | int err; |
| 1073 | |
| 1074 | /* Nobody should be attempting hotplug from these policy contexts. */ |
| 1075 | if (policy == SCHED_BATCH || policy == SCHED_IDLE || |
| 1076 | policy == SCHED_DEADLINE) |
| 1077 | return -EPERM; |
| 1078 | |
| 1079 | if (policy == SCHED_FIFO || policy == SCHED_RR) |
| 1080 | return 1; |
| 1081 | |
| 1082 | /* Only SCHED_NORMAL left. */ |
| 1083 | err = sched_setscheduler_nocheck(current, SCHED_FIFO, ¶m); |
| 1084 | return err; |
| 1085 | |
| 1086 | } |
| 1087 | |
| 1088 | static int switch_to_fair_policy(void) |
| 1089 | { |
| 1090 | struct sched_param param = { .sched_priority = 0 }; |
| 1091 | |
| 1092 | return sched_setscheduler_nocheck(current, SCHED_NORMAL, ¶m); |
| 1093 | } |
| 1094 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1095 | static int do_cpu_up(unsigned int cpu, enum cpuhp_state target) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1096 | { |
| 1097 | int err = 0; |
Syed Rameez Mustafa | b305880 | 2016-12-16 11:59:05 -0800 | [diff] [blame] | 1098 | int switch_err = 0; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 1099 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1100 | if (!cpu_possible(cpu)) { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1101 | pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n", |
| 1102 | cpu); |
Chen Gong | 87d5e02 | 2010-03-05 13:42:38 -0800 | [diff] [blame] | 1103 | #if defined(CONFIG_IA64) |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1104 | pr_err("please check additional_cpus= boot parameter\n"); |
KAMEZAWA Hiroyuki | 73e753a | 2007-10-18 23:40:47 -0700 | [diff] [blame] | 1105 | #endif |
| 1106 | return -EINVAL; |
| 1107 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1108 | |
Syed Rameez Mustafa | b305880 | 2016-12-16 11:59:05 -0800 | [diff] [blame] | 1109 | switch_err = switch_to_rt_policy(); |
| 1110 | if (switch_err < 0) |
| 1111 | return switch_err; |
| 1112 | |
Toshi Kani | 01b0f19 | 2013-11-12 15:07:25 -0800 | [diff] [blame] | 1113 | err = try_online_node(cpu_to_node(cpu)); |
| 1114 | if (err) |
| 1115 | return err; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 1116 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1117 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1118 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 1119 | if (cpu_hotplug_disabled) { |
| 1120 | err = -EBUSY; |
| 1121 | goto out; |
| 1122 | } |
| 1123 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1124 | err = _cpu_up(cpu, 0, target); |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 1125 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1126 | cpu_maps_update_done(); |
Syed Rameez Mustafa | b305880 | 2016-12-16 11:59:05 -0800 | [diff] [blame] | 1127 | |
| 1128 | if (!switch_err) { |
| 1129 | switch_err = switch_to_fair_policy(); |
Pavankumar Kondeti | 657ad05 | 2017-04-14 14:59:40 +0530 | [diff] [blame] | 1130 | if (switch_err) |
| 1131 | pr_err("Hotplug policy switch err=%d Task %s pid=%d\n", |
| 1132 | switch_err, current->comm, current->pid); |
Syed Rameez Mustafa | b305880 | 2016-12-16 11:59:05 -0800 | [diff] [blame] | 1133 | } |
| 1134 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1135 | return err; |
| 1136 | } |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1137 | |
| 1138 | int cpu_up(unsigned int cpu) |
| 1139 | { |
| 1140 | return do_cpu_up(cpu, CPUHP_ONLINE); |
| 1141 | } |
Paul E. McKenney | a513f6b | 2011-12-11 21:54:45 -0800 | [diff] [blame] | 1142 | EXPORT_SYMBOL_GPL(cpu_up); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1143 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 1144 | #ifdef CONFIG_PM_SLEEP_SMP |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1145 | static cpumask_var_t frozen_cpus; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1146 | |
James Morse | d391e55 | 2016-08-17 13:50:25 +0100 | [diff] [blame] | 1147 | int freeze_secondary_cpus(int primary) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1148 | { |
James Morse | d391e55 | 2016-08-17 13:50:25 +0100 | [diff] [blame] | 1149 | int cpu, error = 0; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1150 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1151 | cpu_maps_update_begin(); |
James Morse | d391e55 | 2016-08-17 13:50:25 +0100 | [diff] [blame] | 1152 | if (!cpu_online(primary)) |
| 1153 | primary = cpumask_first(cpu_online_mask); |
Xiaotian Feng | 9ee349a | 2009-12-16 18:04:32 +0100 | [diff] [blame] | 1154 | /* |
| 1155 | * 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] | 1156 | * with the userspace trying to use the CPU hotplug at the same time |
| 1157 | */ |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1158 | cpumask_clear(frozen_cpus); |
Peter Zijlstra | 6ad4c18 | 2009-11-25 13:31:39 +0100 | [diff] [blame] | 1159 | |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1160 | pr_info("Disabling non-boot CPUs ...\n"); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1161 | for_each_online_cpu(cpu) { |
James Morse | d391e55 | 2016-08-17 13:50:25 +0100 | [diff] [blame] | 1162 | if (cpu == primary) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1163 | continue; |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1164 | trace_suspend_resume(TPS("CPU_OFF"), cpu, true); |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1165 | error = _cpu_down(cpu, 1, CPUHP_OFFLINE); |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1166 | trace_suspend_resume(TPS("CPU_OFF"), cpu, false); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 1167 | if (!error) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1168 | cpumask_set_cpu(cpu, frozen_cpus); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 1169 | else { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1170 | pr_err("Error taking CPU%d down: %d\n", cpu, error); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1171 | break; |
| 1172 | } |
| 1173 | } |
Joseph Cihula | 86886e5 | 2009-06-30 19:31:07 -0700 | [diff] [blame] | 1174 | |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1175 | if (!error) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1176 | BUG_ON(num_online_cpus() > 1); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1177 | else |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1178 | pr_err("Non-boot CPUs are not disabled\n"); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1179 | |
| 1180 | /* |
| 1181 | * Make sure the CPUs won't be enabled by someone else. We need to do |
| 1182 | * this even in case of failure as all disable_nonboot_cpus() users are |
| 1183 | * supposed to do enable_nonboot_cpus() on the failure path. |
| 1184 | */ |
| 1185 | cpu_hotplug_disabled++; |
| 1186 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1187 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1188 | return error; |
| 1189 | } |
| 1190 | |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1191 | void __weak arch_enable_nonboot_cpus_begin(void) |
| 1192 | { |
| 1193 | } |
| 1194 | |
| 1195 | void __weak arch_enable_nonboot_cpus_end(void) |
| 1196 | { |
| 1197 | } |
| 1198 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 1199 | void enable_nonboot_cpus(void) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1200 | { |
| 1201 | int cpu, error; |
Thierry Strudel | 0c3610e | 2016-06-14 17:46:44 -0700 | [diff] [blame] | 1202 | struct device *cpu_device; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1203 | |
| 1204 | /* Allow everyone to use the CPU hotplug again */ |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1205 | cpu_maps_update_begin(); |
Lianwei Wang | 01b4115 | 2016-06-09 23:43:28 -0700 | [diff] [blame] | 1206 | __cpu_hotplug_enable(); |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1207 | if (cpumask_empty(frozen_cpus)) |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 1208 | goto out; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1209 | |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1210 | pr_info("Enabling non-boot CPUs ...\n"); |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1211 | |
| 1212 | arch_enable_nonboot_cpus_begin(); |
| 1213 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1214 | for_each_cpu(cpu, frozen_cpus) { |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1215 | trace_suspend_resume(TPS("CPU_ON"), cpu, true); |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1216 | error = _cpu_up(cpu, 1, CPUHP_ONLINE); |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1217 | trace_suspend_resume(TPS("CPU_ON"), cpu, false); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1218 | if (!error) { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1219 | pr_info("CPU%d is up\n", cpu); |
Thierry Strudel | 0c3610e | 2016-06-14 17:46:44 -0700 | [diff] [blame] | 1220 | cpu_device = get_cpu_device(cpu); |
| 1221 | if (!cpu_device) |
| 1222 | pr_err("%s: failed to get cpu%d device\n", |
| 1223 | __func__, cpu); |
| 1224 | else |
| 1225 | kobject_uevent(&cpu_device->kobj, KOBJ_ONLINE); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1226 | continue; |
| 1227 | } |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1228 | pr_warn("Error taking CPU%d up: %d\n", cpu, error); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1229 | } |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1230 | |
| 1231 | arch_enable_nonboot_cpus_end(); |
| 1232 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1233 | cpumask_clear(frozen_cpus); |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 1234 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1235 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1236 | } |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1237 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 1238 | static int __init alloc_frozen_cpus(void) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1239 | { |
| 1240 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) |
| 1241 | return -ENOMEM; |
| 1242 | return 0; |
| 1243 | } |
| 1244 | core_initcall(alloc_frozen_cpus); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1245 | |
| 1246 | /* |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1247 | * When callbacks for CPU hotplug notifications are being executed, we must |
| 1248 | * ensure that the state of the system with respect to the tasks being frozen |
| 1249 | * or not, as reported by the notification, remains unchanged *throughout the |
| 1250 | * duration* of the execution of the callbacks. |
| 1251 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. |
| 1252 | * |
| 1253 | * This synchronization is implemented by mutually excluding regular CPU |
| 1254 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ |
| 1255 | * Hibernate notifications. |
| 1256 | */ |
| 1257 | static int |
| 1258 | cpu_hotplug_pm_callback(struct notifier_block *nb, |
| 1259 | unsigned long action, void *ptr) |
| 1260 | { |
| 1261 | switch (action) { |
| 1262 | |
| 1263 | case PM_SUSPEND_PREPARE: |
| 1264 | case PM_HIBERNATION_PREPARE: |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 1265 | cpu_hotplug_disable(); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1266 | break; |
| 1267 | |
| 1268 | case PM_POST_SUSPEND: |
| 1269 | case PM_POST_HIBERNATION: |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 1270 | cpu_hotplug_enable(); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1271 | break; |
| 1272 | |
| 1273 | default: |
| 1274 | return NOTIFY_DONE; |
| 1275 | } |
| 1276 | |
| 1277 | return NOTIFY_OK; |
| 1278 | } |
| 1279 | |
| 1280 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 1281 | static int __init cpu_hotplug_pm_sync_init(void) |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1282 | { |
Fenghua Yu | 6e32d47 | 2012-11-13 11:32:43 -0800 | [diff] [blame] | 1283 | /* |
| 1284 | * cpu_hotplug_pm_callback has higher priority than x86 |
| 1285 | * bsp_pm_callback which depends on cpu_hotplug_pm_callback |
| 1286 | * to disable cpu hotplug to avoid cpu hotplug race. |
| 1287 | */ |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1288 | pm_notifier(cpu_hotplug_pm_callback, 0); |
| 1289 | return 0; |
| 1290 | } |
| 1291 | core_initcall(cpu_hotplug_pm_sync_init); |
| 1292 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 1293 | #endif /* CONFIG_PM_SLEEP_SMP */ |
Max Krasnyansky | 68f4f1e | 2008-05-29 11:17:02 -0700 | [diff] [blame] | 1294 | |
| 1295 | #endif /* CONFIG_SMP */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1296 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1297 | /* Boot processor state steps */ |
| 1298 | static struct cpuhp_step cpuhp_bp_states[] = { |
| 1299 | [CPUHP_OFFLINE] = { |
| 1300 | .name = "offline", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1301 | .startup.single = NULL, |
| 1302 | .teardown.single = NULL, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1303 | }, |
| 1304 | #ifdef CONFIG_SMP |
| 1305 | [CPUHP_CREATE_THREADS]= { |
Thomas Gleixner | 677f664 | 2016-09-06 16:13:48 +0200 | [diff] [blame] | 1306 | .name = "threads:prepare", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1307 | .startup.single = smpboot_create_threads, |
| 1308 | .teardown.single = NULL, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1309 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1310 | }, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1311 | [CPUHP_PERF_PREPARE] = { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1312 | .name = "perf:prepare", |
| 1313 | .startup.single = perf_event_init_cpu, |
| 1314 | .teardown.single = perf_event_exit_cpu, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1315 | }, |
Thomas Gleixner | 7ee681b | 2016-07-13 17:16:29 +0000 | [diff] [blame] | 1316 | [CPUHP_WORKQUEUE_PREP] = { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1317 | .name = "workqueue:prepare", |
| 1318 | .startup.single = workqueue_prepare_cpu, |
| 1319 | .teardown.single = NULL, |
Thomas Gleixner | 7ee681b | 2016-07-13 17:16:29 +0000 | [diff] [blame] | 1320 | }, |
Thomas Gleixner | 27590dc | 2016-07-15 10:41:04 +0200 | [diff] [blame] | 1321 | [CPUHP_HRTIMERS_PREPARE] = { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1322 | .name = "hrtimers:prepare", |
| 1323 | .startup.single = hrtimers_prepare_cpu, |
| 1324 | .teardown.single = hrtimers_dead_cpu, |
Thomas Gleixner | 27590dc | 2016-07-15 10:41:04 +0200 | [diff] [blame] | 1325 | }, |
Richard Weinberger | 31487f8 | 2016-07-13 17:17:01 +0000 | [diff] [blame] | 1326 | [CPUHP_SMPCFD_PREPARE] = { |
Thomas Gleixner | 677f664 | 2016-09-06 16:13:48 +0200 | [diff] [blame] | 1327 | .name = "smpcfd:prepare", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1328 | .startup.single = smpcfd_prepare_cpu, |
| 1329 | .teardown.single = smpcfd_dead_cpu, |
Richard Weinberger | 31487f8 | 2016-07-13 17:17:01 +0000 | [diff] [blame] | 1330 | }, |
Richard Weinberger | e6d4989 | 2016-08-18 14:57:17 +0200 | [diff] [blame] | 1331 | [CPUHP_RELAY_PREPARE] = { |
| 1332 | .name = "relay:prepare", |
| 1333 | .startup.single = relay_prepare_cpu, |
| 1334 | .teardown.single = NULL, |
| 1335 | }, |
Sebastian Andrzej Siewior | 6731d4f | 2016-08-23 14:53:19 +0200 | [diff] [blame] | 1336 | [CPUHP_SLAB_PREPARE] = { |
| 1337 | .name = "slab:prepare", |
| 1338 | .startup.single = slab_prepare_cpu, |
| 1339 | .teardown.single = slab_dead_cpu, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1340 | }, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1341 | [CPUHP_RCUTREE_PREP] = { |
Thomas Gleixner | 677f664 | 2016-09-06 16:13:48 +0200 | [diff] [blame] | 1342 | .name = "RCU/tree:prepare", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1343 | .startup.single = rcutree_prepare_cpu, |
| 1344 | .teardown.single = rcutree_dead_cpu, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1345 | }, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1346 | /* |
| 1347 | * Preparatory and dead notifiers. Will be replaced once the notifiers |
| 1348 | * are converted to states. |
| 1349 | */ |
| 1350 | [CPUHP_NOTIFY_PREPARE] = { |
| 1351 | .name = "notify:prepare", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1352 | .startup.single = notify_prepare, |
| 1353 | .teardown.single = notify_dead, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1354 | .skip_onerr = true, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1355 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1356 | }, |
Richard Cochran | 4fae16d | 2016-07-27 11:08:18 +0200 | [diff] [blame] | 1357 | /* |
| 1358 | * On the tear-down path, timers_dead_cpu() must be invoked |
| 1359 | * before blk_mq_queue_reinit_notify() from notify_dead(), |
| 1360 | * otherwise a RCU stall occurs. |
| 1361 | */ |
| 1362 | [CPUHP_TIMERS_DEAD] = { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1363 | .name = "timers:dead", |
| 1364 | .startup.single = NULL, |
| 1365 | .teardown.single = timers_dead_cpu, |
Richard Cochran | 4fae16d | 2016-07-27 11:08:18 +0200 | [diff] [blame] | 1366 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1367 | /* Kicks the plugged cpu into life */ |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1368 | [CPUHP_BRINGUP_CPU] = { |
| 1369 | .name = "cpu:bringup", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1370 | .startup.single = bringup_cpu, |
| 1371 | .teardown.single = NULL, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1372 | .cant_stop = true, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1373 | }, |
Richard Weinberger | 31487f8 | 2016-07-13 17:17:01 +0000 | [diff] [blame] | 1374 | [CPUHP_AP_SMPCFD_DYING] = { |
Thomas Gleixner | 677f664 | 2016-09-06 16:13:48 +0200 | [diff] [blame] | 1375 | .name = "smpcfd:dying", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1376 | .startup.single = NULL, |
| 1377 | .teardown.single = smpcfd_dying_cpu, |
Richard Weinberger | 31487f8 | 2016-07-13 17:17:01 +0000 | [diff] [blame] | 1378 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1379 | /* |
| 1380 | * Handled on controll processor until the plugged processor manages |
| 1381 | * this itself. |
| 1382 | */ |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1383 | [CPUHP_TEARDOWN_CPU] = { |
| 1384 | .name = "cpu:teardown", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1385 | .startup.single = NULL, |
| 1386 | .teardown.single = takedown_cpu, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1387 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1388 | }, |
Thomas Gleixner | a7c73414 | 2016-07-12 21:59:23 +0200 | [diff] [blame] | 1389 | #else |
| 1390 | [CPUHP_BRINGUP_CPU] = { }, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1391 | #endif |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1392 | }; |
| 1393 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1394 | /* Application processor state steps */ |
| 1395 | static struct cpuhp_step cpuhp_ap_states[] = { |
| 1396 | #ifdef CONFIG_SMP |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1397 | /* Final state before CPU kills itself */ |
| 1398 | [CPUHP_AP_IDLE_DEAD] = { |
| 1399 | .name = "idle:dead", |
| 1400 | }, |
| 1401 | /* |
| 1402 | * Last state before CPU enters the idle loop to die. Transient state |
| 1403 | * for synchronization. |
| 1404 | */ |
| 1405 | [CPUHP_AP_OFFLINE] = { |
| 1406 | .name = "ap:offline", |
| 1407 | .cant_stop = true, |
| 1408 | }, |
Thomas Gleixner | 9cf7243 | 2016-03-10 12:54:09 +0100 | [diff] [blame] | 1409 | /* First state is scheduler control. Interrupts are disabled */ |
| 1410 | [CPUHP_AP_SCHED_STARTING] = { |
| 1411 | .name = "sched:starting", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1412 | .startup.single = sched_cpu_starting, |
| 1413 | .teardown.single = sched_cpu_dying, |
Thomas Gleixner | 9cf7243 | 2016-03-10 12:54:09 +0100 | [diff] [blame] | 1414 | }, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1415 | [CPUHP_AP_RCUTREE_DYING] = { |
Thomas Gleixner | 677f664 | 2016-09-06 16:13:48 +0200 | [diff] [blame] | 1416 | .name = "RCU/tree:dying", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1417 | .startup.single = NULL, |
| 1418 | .teardown.single = rcutree_dying_cpu, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1419 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1420 | /* Entry state on starting. Interrupts enabled from here on. Transient |
| 1421 | * state for synchronsization */ |
| 1422 | [CPUHP_AP_ONLINE] = { |
| 1423 | .name = "ap:online", |
| 1424 | }, |
| 1425 | /* Handle smpboot threads park/unpark */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1426 | [CPUHP_AP_SMPBOOT_THREADS] = { |
Thomas Gleixner | 677f664 | 2016-09-06 16:13:48 +0200 | [diff] [blame] | 1427 | .name = "smpboot/threads:online", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1428 | .startup.single = smpboot_unpark_threads, |
| 1429 | .teardown.single = NULL, |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1430 | }, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1431 | [CPUHP_AP_PERF_ONLINE] = { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1432 | .name = "perf:online", |
| 1433 | .startup.single = perf_event_init_cpu, |
| 1434 | .teardown.single = perf_event_exit_cpu, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1435 | }, |
Thomas Gleixner | 7ee681b | 2016-07-13 17:16:29 +0000 | [diff] [blame] | 1436 | [CPUHP_AP_WORKQUEUE_ONLINE] = { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1437 | .name = "workqueue:online", |
| 1438 | .startup.single = workqueue_online_cpu, |
| 1439 | .teardown.single = workqueue_offline_cpu, |
Thomas Gleixner | 7ee681b | 2016-07-13 17:16:29 +0000 | [diff] [blame] | 1440 | }, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1441 | [CPUHP_AP_RCUTREE_ONLINE] = { |
Thomas Gleixner | 677f664 | 2016-09-06 16:13:48 +0200 | [diff] [blame] | 1442 | .name = "RCU/tree:online", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1443 | .startup.single = rcutree_online_cpu, |
| 1444 | .teardown.single = rcutree_offline_cpu, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1445 | }, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1446 | |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1447 | /* |
| 1448 | * Online/down_prepare notifiers. Will be removed once the notifiers |
| 1449 | * are converted to states. |
| 1450 | */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1451 | [CPUHP_AP_NOTIFY_ONLINE] = { |
| 1452 | .name = "notify:online", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1453 | .startup.single = notify_online, |
| 1454 | .teardown.single = notify_down_prepare, |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 1455 | .skip_onerr = true, |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1456 | }, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1457 | #endif |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1458 | /* |
| 1459 | * The dynamically registered state space is here |
| 1460 | */ |
| 1461 | |
Thomas Gleixner | aaddd7d | 2016-03-10 12:54:19 +0100 | [diff] [blame] | 1462 | #ifdef CONFIG_SMP |
| 1463 | /* Last state is scheduler control setting the cpu active */ |
| 1464 | [CPUHP_AP_ACTIVE] = { |
| 1465 | .name = "sched:active", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1466 | .startup.single = sched_cpu_activate, |
| 1467 | .teardown.single = sched_cpu_deactivate, |
Thomas Gleixner | aaddd7d | 2016-03-10 12:54:19 +0100 | [diff] [blame] | 1468 | }, |
| 1469 | #endif |
| 1470 | |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1471 | /* CPU is fully up and running. */ |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1472 | [CPUHP_ONLINE] = { |
| 1473 | .name = "online", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1474 | .startup.single = NULL, |
| 1475 | .teardown.single = NULL, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1476 | }, |
| 1477 | }; |
| 1478 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1479 | /* Sanity check for callbacks */ |
| 1480 | static int cpuhp_cb_check(enum cpuhp_state state) |
| 1481 | { |
| 1482 | if (state <= CPUHP_OFFLINE || state >= CPUHP_ONLINE) |
| 1483 | return -EINVAL; |
| 1484 | return 0; |
| 1485 | } |
| 1486 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1487 | static void cpuhp_store_callbacks(enum cpuhp_state state, |
| 1488 | const char *name, |
| 1489 | int (*startup)(unsigned int cpu), |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1490 | int (*teardown)(unsigned int cpu), |
| 1491 | bool multi_instance) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1492 | { |
| 1493 | /* (Un)Install the callbacks for further cpu hotplug operations */ |
| 1494 | struct cpuhp_step *sp; |
| 1495 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1496 | sp = cpuhp_get_step(state); |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1497 | sp->startup.single = startup; |
| 1498 | sp->teardown.single = teardown; |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1499 | sp->name = name; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1500 | sp->multi_instance = multi_instance; |
| 1501 | INIT_HLIST_HEAD(&sp->list); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1502 | } |
| 1503 | |
| 1504 | static void *cpuhp_get_teardown_cb(enum cpuhp_state state) |
| 1505 | { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1506 | return cpuhp_get_step(state)->teardown.single; |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1507 | } |
| 1508 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1509 | /* |
| 1510 | * Call the startup/teardown function for a step either on the AP or |
| 1511 | * on the current CPU. |
| 1512 | */ |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1513 | static int cpuhp_issue_call(int cpu, enum cpuhp_state state, bool bringup, |
| 1514 | struct hlist_node *node) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1515 | { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 1516 | struct cpuhp_step *sp = cpuhp_get_step(state); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1517 | int ret; |
| 1518 | |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1519 | if ((bringup && !sp->startup.single) || |
| 1520 | (!bringup && !sp->teardown.single)) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1521 | return 0; |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1522 | /* |
| 1523 | * The non AP bound callbacks can fail on bringup. On teardown |
| 1524 | * e.g. module removal we crash for now. |
| 1525 | */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1526 | #ifdef CONFIG_SMP |
| 1527 | if (cpuhp_is_ap_state(state)) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1528 | ret = cpuhp_invoke_ap_callback(cpu, state, bringup, node); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1529 | else |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1530 | ret = cpuhp_invoke_callback(cpu, state, bringup, node); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1531 | #else |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1532 | ret = cpuhp_invoke_callback(cpu, state, bringup, node); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1533 | #endif |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1534 | BUG_ON(ret && !bringup); |
| 1535 | return ret; |
| 1536 | } |
| 1537 | |
| 1538 | /* |
| 1539 | * Called from __cpuhp_setup_state on a recoverable failure. |
| 1540 | * |
| 1541 | * Note: The teardown callbacks for rollback are not allowed to fail! |
| 1542 | */ |
| 1543 | static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state, |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1544 | struct hlist_node *node) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1545 | { |
| 1546 | int cpu; |
| 1547 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1548 | /* Roll back the already executed steps on the other cpus */ |
| 1549 | for_each_present_cpu(cpu) { |
| 1550 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1551 | int cpustate = st->state; |
| 1552 | |
| 1553 | if (cpu >= failedcpu) |
| 1554 | break; |
| 1555 | |
| 1556 | /* Did we invoke the startup call on that cpu ? */ |
| 1557 | if (cpustate >= state) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1558 | cpuhp_issue_call(cpu, state, false, node); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1559 | } |
| 1560 | } |
| 1561 | |
| 1562 | /* |
| 1563 | * Returns a free for dynamic slot assignment of the Online state. The states |
| 1564 | * are protected by the cpuhp_slot_states mutex and an empty slot is identified |
| 1565 | * by having no name assigned. |
| 1566 | */ |
| 1567 | static int cpuhp_reserve_state(enum cpuhp_state state) |
| 1568 | { |
| 1569 | enum cpuhp_state i; |
| 1570 | |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1571 | for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) { |
| 1572 | if (cpuhp_ap_states[i].name) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1573 | continue; |
| 1574 | |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1575 | cpuhp_ap_states[i].name = "Reserved"; |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1576 | return i; |
| 1577 | } |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1578 | WARN(1, "No more dynamic states available for CPU hotplug\n"); |
| 1579 | return -ENOSPC; |
| 1580 | } |
| 1581 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1582 | int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node, |
| 1583 | bool invoke) |
| 1584 | { |
| 1585 | struct cpuhp_step *sp; |
| 1586 | int cpu; |
| 1587 | int ret; |
| 1588 | |
| 1589 | sp = cpuhp_get_step(state); |
| 1590 | if (sp->multi_instance == false) |
| 1591 | return -EINVAL; |
| 1592 | |
| 1593 | get_online_cpus(); |
Sebastian Andrzej Siewior | 7ad6de4 | 2017-03-14 16:06:45 +0100 | [diff] [blame] | 1594 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1595 | |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1596 | if (!invoke || !sp->startup.multi) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1597 | goto add_node; |
| 1598 | |
| 1599 | /* |
| 1600 | * Try to call the startup callback for each present cpu |
| 1601 | * depending on the hotplug state of the cpu. |
| 1602 | */ |
| 1603 | for_each_present_cpu(cpu) { |
| 1604 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1605 | int cpustate = st->state; |
| 1606 | |
| 1607 | if (cpustate < state) |
| 1608 | continue; |
| 1609 | |
| 1610 | ret = cpuhp_issue_call(cpu, state, true, node); |
| 1611 | if (ret) { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1612 | if (sp->teardown.multi) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1613 | cpuhp_rollback_install(cpu, state, node); |
| 1614 | goto err; |
| 1615 | } |
| 1616 | } |
| 1617 | add_node: |
| 1618 | ret = 0; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1619 | hlist_add_head(node, &sp->list); |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1620 | |
| 1621 | err: |
Sebastian Andrzej Siewior | 7ad6de4 | 2017-03-14 16:06:45 +0100 | [diff] [blame] | 1622 | mutex_unlock(&cpuhp_state_mutex); |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1623 | put_online_cpus(); |
| 1624 | return ret; |
| 1625 | } |
| 1626 | EXPORT_SYMBOL_GPL(__cpuhp_state_add_instance); |
| 1627 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1628 | /** |
| 1629 | * __cpuhp_setup_state - Setup the callbacks for an hotplug machine state |
| 1630 | * @state: The state to setup |
| 1631 | * @invoke: If true, the startup function is invoked for cpus where |
| 1632 | * cpu state >= @state |
| 1633 | * @startup: startup callback function |
| 1634 | * @teardown: teardown callback function |
| 1635 | * |
| 1636 | * Returns 0 if successful, otherwise a proper error code |
| 1637 | */ |
| 1638 | int __cpuhp_setup_state(enum cpuhp_state state, |
| 1639 | const char *name, bool invoke, |
| 1640 | int (*startup)(unsigned int cpu), |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1641 | int (*teardown)(unsigned int cpu), |
| 1642 | bool multi_instance) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1643 | { |
| 1644 | int cpu, ret = 0; |
| 1645 | int dyn_state = 0; |
| 1646 | |
| 1647 | if (cpuhp_cb_check(state) || !name) |
| 1648 | return -EINVAL; |
| 1649 | |
| 1650 | get_online_cpus(); |
Sebastian Andrzej Siewior | 7ad6de4 | 2017-03-14 16:06:45 +0100 | [diff] [blame] | 1651 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1652 | |
| 1653 | /* currently assignments for the ONLINE state are possible */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1654 | if (state == CPUHP_AP_ONLINE_DYN) { |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1655 | dyn_state = 1; |
| 1656 | ret = cpuhp_reserve_state(state); |
| 1657 | if (ret < 0) |
| 1658 | goto out; |
| 1659 | state = ret; |
| 1660 | } |
| 1661 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1662 | cpuhp_store_callbacks(state, name, startup, teardown, multi_instance); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1663 | |
| 1664 | if (!invoke || !startup) |
| 1665 | goto out; |
| 1666 | |
| 1667 | /* |
| 1668 | * Try to call the startup callback for each present cpu |
| 1669 | * depending on the hotplug state of the cpu. |
| 1670 | */ |
| 1671 | for_each_present_cpu(cpu) { |
| 1672 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1673 | int cpustate = st->state; |
| 1674 | |
| 1675 | if (cpustate < state) |
| 1676 | continue; |
| 1677 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1678 | ret = cpuhp_issue_call(cpu, state, true, NULL); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1679 | if (ret) { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 1680 | if (teardown) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1681 | cpuhp_rollback_install(cpu, state, NULL); |
| 1682 | cpuhp_store_callbacks(state, NULL, NULL, NULL, false); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1683 | goto out; |
| 1684 | } |
| 1685 | } |
| 1686 | out: |
Sebastian Andrzej Siewior | 7ad6de4 | 2017-03-14 16:06:45 +0100 | [diff] [blame] | 1687 | mutex_unlock(&cpuhp_state_mutex); |
| 1688 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1689 | put_online_cpus(); |
| 1690 | if (!ret && dyn_state) |
| 1691 | return state; |
| 1692 | return ret; |
| 1693 | } |
| 1694 | EXPORT_SYMBOL(__cpuhp_setup_state); |
| 1695 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1696 | int __cpuhp_state_remove_instance(enum cpuhp_state state, |
| 1697 | struct hlist_node *node, bool invoke) |
| 1698 | { |
| 1699 | struct cpuhp_step *sp = cpuhp_get_step(state); |
| 1700 | int cpu; |
| 1701 | |
| 1702 | BUG_ON(cpuhp_cb_check(state)); |
| 1703 | |
| 1704 | if (!sp->multi_instance) |
| 1705 | return -EINVAL; |
| 1706 | |
| 1707 | get_online_cpus(); |
Sebastian Andrzej Siewior | 7ad6de4 | 2017-03-14 16:06:45 +0100 | [diff] [blame] | 1708 | mutex_lock(&cpuhp_state_mutex); |
| 1709 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1710 | if (!invoke || !cpuhp_get_teardown_cb(state)) |
| 1711 | goto remove; |
| 1712 | /* |
| 1713 | * Call the teardown callback for each present cpu depending |
| 1714 | * on the hotplug state of the cpu. This function is not |
| 1715 | * allowed to fail currently! |
| 1716 | */ |
| 1717 | for_each_present_cpu(cpu) { |
| 1718 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1719 | int cpustate = st->state; |
| 1720 | |
| 1721 | if (cpustate >= state) |
| 1722 | cpuhp_issue_call(cpu, state, false, node); |
| 1723 | } |
| 1724 | |
| 1725 | remove: |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1726 | hlist_del(node); |
| 1727 | mutex_unlock(&cpuhp_state_mutex); |
| 1728 | put_online_cpus(); |
| 1729 | |
| 1730 | return 0; |
| 1731 | } |
| 1732 | EXPORT_SYMBOL_GPL(__cpuhp_state_remove_instance); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1733 | /** |
| 1734 | * __cpuhp_remove_state - Remove the callbacks for an hotplug machine state |
| 1735 | * @state: The state to remove |
| 1736 | * @invoke: If true, the teardown function is invoked for cpus where |
| 1737 | * cpu state >= @state |
| 1738 | * |
| 1739 | * The teardown callback is currently not allowed to fail. Think |
| 1740 | * about module removal! |
| 1741 | */ |
| 1742 | void __cpuhp_remove_state(enum cpuhp_state state, bool invoke) |
| 1743 | { |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1744 | struct cpuhp_step *sp = cpuhp_get_step(state); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1745 | int cpu; |
| 1746 | |
| 1747 | BUG_ON(cpuhp_cb_check(state)); |
| 1748 | |
| 1749 | get_online_cpus(); |
Sebastian Andrzej Siewior | 7ad6de4 | 2017-03-14 16:06:45 +0100 | [diff] [blame] | 1750 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1751 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1752 | if (sp->multi_instance) { |
| 1753 | WARN(!hlist_empty(&sp->list), |
| 1754 | "Error: Removing state %d which has instances left.\n", |
| 1755 | state); |
| 1756 | goto remove; |
| 1757 | } |
| 1758 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 1759 | if (!invoke || !cpuhp_get_teardown_cb(state)) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1760 | goto remove; |
| 1761 | |
| 1762 | /* |
| 1763 | * Call the teardown callback for each present cpu depending |
| 1764 | * on the hotplug state of the cpu. This function is not |
| 1765 | * allowed to fail currently! |
| 1766 | */ |
| 1767 | for_each_present_cpu(cpu) { |
| 1768 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1769 | int cpustate = st->state; |
| 1770 | |
| 1771 | if (cpustate >= state) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1772 | cpuhp_issue_call(cpu, state, false, NULL); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1773 | } |
| 1774 | remove: |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1775 | cpuhp_store_callbacks(state, NULL, NULL, NULL, false); |
Sebastian Andrzej Siewior | 7ad6de4 | 2017-03-14 16:06:45 +0100 | [diff] [blame] | 1776 | mutex_unlock(&cpuhp_state_mutex); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1777 | put_online_cpus(); |
| 1778 | } |
| 1779 | EXPORT_SYMBOL(__cpuhp_remove_state); |
| 1780 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1781 | #if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU) |
| 1782 | static ssize_t show_cpuhp_state(struct device *dev, |
| 1783 | struct device_attribute *attr, char *buf) |
| 1784 | { |
| 1785 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1786 | |
| 1787 | return sprintf(buf, "%d\n", st->state); |
| 1788 | } |
| 1789 | static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL); |
| 1790 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1791 | static ssize_t write_cpuhp_target(struct device *dev, |
| 1792 | struct device_attribute *attr, |
| 1793 | const char *buf, size_t count) |
| 1794 | { |
| 1795 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1796 | struct cpuhp_step *sp; |
| 1797 | int target, ret; |
| 1798 | |
| 1799 | ret = kstrtoint(buf, 10, &target); |
| 1800 | if (ret) |
| 1801 | return ret; |
| 1802 | |
| 1803 | #ifdef CONFIG_CPU_HOTPLUG_STATE_CONTROL |
| 1804 | if (target < CPUHP_OFFLINE || target > CPUHP_ONLINE) |
| 1805 | return -EINVAL; |
| 1806 | #else |
| 1807 | if (target != CPUHP_OFFLINE && target != CPUHP_ONLINE) |
| 1808 | return -EINVAL; |
| 1809 | #endif |
| 1810 | |
| 1811 | ret = lock_device_hotplug_sysfs(); |
| 1812 | if (ret) |
| 1813 | return ret; |
| 1814 | |
| 1815 | mutex_lock(&cpuhp_state_mutex); |
| 1816 | sp = cpuhp_get_step(target); |
| 1817 | ret = !sp->name || sp->cant_stop ? -EINVAL : 0; |
| 1818 | mutex_unlock(&cpuhp_state_mutex); |
| 1819 | if (ret) |
Sebastian Andrzej Siewior | 106c77e | 2017-06-02 16:27:14 +0200 | [diff] [blame] | 1820 | goto out; |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1821 | |
| 1822 | if (st->state < target) |
| 1823 | ret = do_cpu_up(dev->id, target); |
| 1824 | else |
| 1825 | ret = do_cpu_down(dev->id, target); |
Sebastian Andrzej Siewior | 106c77e | 2017-06-02 16:27:14 +0200 | [diff] [blame] | 1826 | out: |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1827 | unlock_device_hotplug(); |
| 1828 | return ret ? ret : count; |
| 1829 | } |
| 1830 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1831 | static ssize_t show_cpuhp_target(struct device *dev, |
| 1832 | struct device_attribute *attr, char *buf) |
| 1833 | { |
| 1834 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1835 | |
| 1836 | return sprintf(buf, "%d\n", st->target); |
| 1837 | } |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1838 | static DEVICE_ATTR(target, 0644, show_cpuhp_target, write_cpuhp_target); |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1839 | |
| 1840 | static struct attribute *cpuhp_cpu_attrs[] = { |
| 1841 | &dev_attr_state.attr, |
| 1842 | &dev_attr_target.attr, |
| 1843 | NULL |
| 1844 | }; |
| 1845 | |
| 1846 | static struct attribute_group cpuhp_cpu_attr_group = { |
| 1847 | .attrs = cpuhp_cpu_attrs, |
| 1848 | .name = "hotplug", |
| 1849 | NULL |
| 1850 | }; |
| 1851 | |
| 1852 | static ssize_t show_cpuhp_states(struct device *dev, |
| 1853 | struct device_attribute *attr, char *buf) |
| 1854 | { |
| 1855 | ssize_t cur, res = 0; |
| 1856 | int i; |
| 1857 | |
| 1858 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1859 | for (i = CPUHP_OFFLINE; i <= CPUHP_ONLINE; i++) { |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1860 | struct cpuhp_step *sp = cpuhp_get_step(i); |
| 1861 | |
| 1862 | if (sp->name) { |
| 1863 | cur = sprintf(buf, "%3d: %s\n", i, sp->name); |
| 1864 | buf += cur; |
| 1865 | res += cur; |
| 1866 | } |
| 1867 | } |
| 1868 | mutex_unlock(&cpuhp_state_mutex); |
| 1869 | return res; |
| 1870 | } |
| 1871 | static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL); |
| 1872 | |
| 1873 | static struct attribute *cpuhp_cpu_root_attrs[] = { |
| 1874 | &dev_attr_states.attr, |
| 1875 | NULL |
| 1876 | }; |
| 1877 | |
| 1878 | static struct attribute_group cpuhp_cpu_root_attr_group = { |
| 1879 | .attrs = cpuhp_cpu_root_attrs, |
| 1880 | .name = "hotplug", |
| 1881 | NULL |
| 1882 | }; |
| 1883 | |
| 1884 | static int __init cpuhp_sysfs_init(void) |
| 1885 | { |
| 1886 | int cpu, ret; |
| 1887 | |
| 1888 | ret = sysfs_create_group(&cpu_subsys.dev_root->kobj, |
| 1889 | &cpuhp_cpu_root_attr_group); |
| 1890 | if (ret) |
| 1891 | return ret; |
| 1892 | |
| 1893 | for_each_possible_cpu(cpu) { |
| 1894 | struct device *dev = get_cpu_device(cpu); |
| 1895 | |
| 1896 | if (!dev) |
| 1897 | continue; |
| 1898 | ret = sysfs_create_group(&dev->kobj, &cpuhp_cpu_attr_group); |
| 1899 | if (ret) |
| 1900 | return ret; |
| 1901 | } |
| 1902 | return 0; |
| 1903 | } |
| 1904 | device_initcall(cpuhp_sysfs_init); |
| 1905 | #endif |
| 1906 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1907 | /* |
| 1908 | * cpu_bit_bitmap[] is a special, "compressed" data structure that |
| 1909 | * represents all NR_CPUS bits binary values of 1<<nr. |
| 1910 | * |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1911 | * 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] | 1912 | * mask value that has a single bit set only. |
| 1913 | */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1914 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1915 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 1916 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1917 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) |
| 1918 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) |
| 1919 | #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] | 1920 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1921 | 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] | 1922 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1923 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), |
| 1924 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), |
| 1925 | #if BITS_PER_LONG > 32 |
| 1926 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), |
| 1927 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1928 | #endif |
| 1929 | }; |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1930 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1931 | |
| 1932 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; |
| 1933 | EXPORT_SYMBOL(cpu_all_bits); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1934 | |
| 1935 | #ifdef CONFIG_INIT_ALL_POSSIBLE |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1936 | struct cpumask __cpu_possible_mask __read_mostly |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1937 | = {CPU_BITS_ALL}; |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1938 | #else |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1939 | struct cpumask __cpu_possible_mask __read_mostly; |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1940 | #endif |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1941 | EXPORT_SYMBOL(__cpu_possible_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1942 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1943 | struct cpumask __cpu_online_mask __read_mostly; |
| 1944 | EXPORT_SYMBOL(__cpu_online_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1945 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1946 | struct cpumask __cpu_present_mask __read_mostly; |
| 1947 | EXPORT_SYMBOL(__cpu_present_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1948 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1949 | struct cpumask __cpu_active_mask __read_mostly; |
| 1950 | EXPORT_SYMBOL(__cpu_active_mask); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1951 | |
Olav Haugan | 99cd46a | 2016-05-29 19:56:37 -0700 | [diff] [blame] | 1952 | struct cpumask __cpu_isolated_mask __read_mostly; |
| 1953 | EXPORT_SYMBOL(__cpu_isolated_mask); |
| 1954 | |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1955 | void init_cpu_present(const struct cpumask *src) |
| 1956 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1957 | cpumask_copy(&__cpu_present_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1958 | } |
| 1959 | |
| 1960 | void init_cpu_possible(const struct cpumask *src) |
| 1961 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1962 | cpumask_copy(&__cpu_possible_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1963 | } |
| 1964 | |
| 1965 | void init_cpu_online(const struct cpumask *src) |
| 1966 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1967 | cpumask_copy(&__cpu_online_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1968 | } |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1969 | |
Olav Haugan | 99cd46a | 2016-05-29 19:56:37 -0700 | [diff] [blame] | 1970 | void init_cpu_isolated(const struct cpumask *src) |
| 1971 | { |
| 1972 | cpumask_copy(&__cpu_isolated_mask, src); |
| 1973 | } |
| 1974 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1975 | /* |
| 1976 | * Activate the first processor. |
| 1977 | */ |
| 1978 | void __init boot_cpu_init(void) |
| 1979 | { |
| 1980 | int cpu = smp_processor_id(); |
| 1981 | |
| 1982 | /* Mark the boot cpu "present", "online" etc for SMP and UP case */ |
| 1983 | set_cpu_online(cpu, true); |
| 1984 | set_cpu_active(cpu, true); |
| 1985 | set_cpu_present(cpu, true); |
| 1986 | set_cpu_possible(cpu, true); |
| 1987 | } |
| 1988 | |
| 1989 | /* |
| 1990 | * Must be called _AFTER_ setting up the per_cpu areas |
| 1991 | */ |
| 1992 | void __init boot_cpu_state_init(void) |
| 1993 | { |
| 1994 | per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE; |
| 1995 | } |
Todd Poynor | ef07e9e4 | 2011-06-15 17:21:57 -0700 | [diff] [blame] | 1996 | |
| 1997 | static ATOMIC_NOTIFIER_HEAD(idle_notifier); |
| 1998 | |
| 1999 | void idle_notifier_register(struct notifier_block *n) |
| 2000 | { |
| 2001 | atomic_notifier_chain_register(&idle_notifier, n); |
| 2002 | } |
| 2003 | EXPORT_SYMBOL_GPL(idle_notifier_register); |
| 2004 | |
| 2005 | void idle_notifier_unregister(struct notifier_block *n) |
| 2006 | { |
| 2007 | atomic_notifier_chain_unregister(&idle_notifier, n); |
| 2008 | } |
| 2009 | EXPORT_SYMBOL_GPL(idle_notifier_unregister); |
| 2010 | |
| 2011 | void idle_notifier_call_chain(unsigned long val) |
| 2012 | { |
| 2013 | atomic_notifier_call_chain(&idle_notifier, val, NULL); |
| 2014 | } |
| 2015 | EXPORT_SYMBOL_GPL(idle_notifier_call_chain); |