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> |
Maria Yu | e90f8e1 | 2017-09-21 11:30:53 +0800 | [diff] [blame] | 28 | #include <linux/highmem.h> |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 29 | |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 30 | #include <trace/events/power.h> |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 31 | #define CREATE_TRACE_POINTS |
| 32 | #include <trace/events/cpuhp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 34 | #include "smpboot.h" |
| 35 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 36 | /** |
| 37 | * cpuhp_cpu_state - Per cpu hotplug state storage |
| 38 | * @state: The current cpu state |
| 39 | * @target: The target state |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 40 | * @thread: Pointer to the hotplug thread |
| 41 | * @should_run: Thread should execute |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 42 | * @rollback: Perform a rollback |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 43 | * @single: Single callback invocation |
| 44 | * @bringup: Single callback bringup or teardown selector |
| 45 | * @cb_state: The state for a single callback (install/uninstall) |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 46 | * @result: Result of the operation |
| 47 | * @done: Signal completion to the issuer of the task |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 48 | */ |
| 49 | struct cpuhp_cpu_state { |
| 50 | enum cpuhp_state state; |
| 51 | enum cpuhp_state target; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 52 | #ifdef CONFIG_SMP |
| 53 | struct task_struct *thread; |
| 54 | bool should_run; |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 55 | bool rollback; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 56 | bool single; |
| 57 | bool bringup; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 58 | struct hlist_node *node; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 59 | enum cpuhp_state cb_state; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 60 | int result; |
| 61 | struct completion done; |
| 62 | #endif |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 63 | }; |
| 64 | |
| 65 | static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state); |
| 66 | |
| 67 | /** |
| 68 | * cpuhp_step - Hotplug state machine step |
| 69 | * @name: Name of the step |
| 70 | * @startup: Startup function of the step |
| 71 | * @teardown: Teardown function of the step |
| 72 | * @skip_onerr: Do not invoke the functions on error rollback |
| 73 | * Will go away once the notifiers are gone |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 74 | * @cant_stop: Bringup/teardown can't be stopped at this step |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 75 | */ |
| 76 | struct cpuhp_step { |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 77 | const char *name; |
| 78 | union { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 79 | int (*single)(unsigned int cpu); |
| 80 | int (*multi)(unsigned int cpu, |
| 81 | struct hlist_node *node); |
| 82 | } startup; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 83 | union { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 84 | int (*single)(unsigned int cpu); |
| 85 | int (*multi)(unsigned int cpu, |
| 86 | struct hlist_node *node); |
| 87 | } teardown; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 88 | struct hlist_head list; |
| 89 | bool skip_onerr; |
| 90 | bool cant_stop; |
| 91 | bool multi_instance; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 92 | }; |
| 93 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 94 | static DEFINE_MUTEX(cpuhp_state_mutex); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 95 | static struct cpuhp_step cpuhp_bp_states[]; |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 96 | static struct cpuhp_step cpuhp_ap_states[]; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 97 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 98 | static bool cpuhp_is_ap_state(enum cpuhp_state state) |
| 99 | { |
| 100 | /* |
| 101 | * The extra check for CPUHP_TEARDOWN_CPU is only for documentation |
| 102 | * purposes as that state is handled explicitly in cpu_down. |
| 103 | */ |
| 104 | return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU; |
| 105 | } |
| 106 | |
| 107 | static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state) |
| 108 | { |
| 109 | struct cpuhp_step *sp; |
| 110 | |
| 111 | sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states; |
| 112 | return sp + state; |
| 113 | } |
| 114 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 115 | /** |
| 116 | * cpuhp_invoke_callback _ Invoke the callbacks for a given state |
| 117 | * @cpu: The cpu for which the callback should be invoked |
| 118 | * @step: The step in the state machine |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 119 | * @bringup: True if the bringup callback should be invoked |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 120 | * |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 121 | * Called from cpu hotplug and from the state register machinery. |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 122 | */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 123 | static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state, |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 124 | bool bringup, struct hlist_node *node) |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 125 | { |
| 126 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 127 | struct cpuhp_step *step = cpuhp_get_step(state); |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 128 | int (*cbm)(unsigned int cpu, struct hlist_node *node); |
| 129 | int (*cb)(unsigned int cpu); |
| 130 | int ret, cnt; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 131 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 132 | if (!step->multi_instance) { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 133 | cb = bringup ? step->startup.single : step->teardown.single; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 134 | if (!cb) |
| 135 | return 0; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 136 | trace_cpuhp_enter(cpu, st->target, state, cb); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 137 | ret = cb(cpu); |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 138 | trace_cpuhp_exit(cpu, st->state, state, ret); |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 139 | return ret; |
| 140 | } |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 141 | cbm = bringup ? step->startup.multi : step->teardown.multi; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 142 | if (!cbm) |
| 143 | return 0; |
| 144 | |
| 145 | /* Single invocation for instance add/remove */ |
| 146 | if (node) { |
| 147 | trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node); |
| 148 | ret = cbm(cpu, node); |
| 149 | trace_cpuhp_exit(cpu, st->state, state, ret); |
| 150 | return ret; |
| 151 | } |
| 152 | |
| 153 | /* State transition. Invoke on all instances */ |
| 154 | cnt = 0; |
| 155 | hlist_for_each(node, &step->list) { |
| 156 | trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node); |
| 157 | ret = cbm(cpu, node); |
| 158 | trace_cpuhp_exit(cpu, st->state, state, ret); |
| 159 | if (ret) |
| 160 | goto err; |
| 161 | cnt++; |
| 162 | } |
| 163 | return 0; |
| 164 | err: |
| 165 | /* Rollback the instances if one failed */ |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 166 | cbm = !bringup ? step->startup.multi : step->teardown.multi; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 167 | if (!cbm) |
| 168 | return ret; |
| 169 | |
| 170 | hlist_for_each(node, &step->list) { |
| 171 | if (!cnt--) |
| 172 | break; |
| 173 | cbm(cpu, node); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 174 | } |
| 175 | return ret; |
| 176 | } |
| 177 | |
Rusty Russell | 98a79d6 | 2008-12-13 21:19:41 +1030 | [diff] [blame] | 178 | #ifdef CONFIG_SMP |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 179 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 180 | static DEFINE_MUTEX(cpu_add_remove_lock); |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 181 | bool cpuhp_tasks_frozen; |
| 182 | EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 184 | /* |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 185 | * The following two APIs (cpu_maps_update_begin/done) must be used when |
| 186 | * attempting to serialize the updates to cpu_online_mask & cpu_present_mask. |
| 187 | * The APIs cpu_notifier_register_begin/done() must be used to protect CPU |
| 188 | * hotplug callback (un)registration performed using __register_cpu_notifier() |
| 189 | * or __unregister_cpu_notifier(). |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 190 | */ |
| 191 | void cpu_maps_update_begin(void) |
| 192 | { |
| 193 | mutex_lock(&cpu_add_remove_lock); |
| 194 | } |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 195 | EXPORT_SYMBOL(cpu_notifier_register_begin); |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 196 | |
| 197 | void cpu_maps_update_done(void) |
| 198 | { |
| 199 | mutex_unlock(&cpu_add_remove_lock); |
| 200 | } |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 201 | EXPORT_SYMBOL(cpu_notifier_register_done); |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 202 | |
Daniel J Blueman | 5c113fb | 2010-06-01 12:15:11 +0100 | [diff] [blame] | 203 | static RAW_NOTIFIER_HEAD(cpu_chain); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 205 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
| 206 | * Should always be manipulated under cpu_add_remove_lock |
| 207 | */ |
| 208 | static int cpu_hotplug_disabled; |
| 209 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 210 | #ifdef CONFIG_HOTPLUG_CPU |
| 211 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 212 | static struct { |
| 213 | struct task_struct *active_writer; |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 214 | /* wait queue to wake up the active_writer */ |
| 215 | wait_queue_head_t wq; |
| 216 | /* verifies that no writer will get active while readers are active */ |
| 217 | struct mutex lock; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 218 | /* |
| 219 | * Also blocks the new readers during |
| 220 | * an ongoing cpu hotplug operation. |
| 221 | */ |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 222 | atomic_t refcount; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 223 | |
| 224 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| 225 | struct lockdep_map dep_map; |
| 226 | #endif |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 227 | } cpu_hotplug = { |
| 228 | .active_writer = NULL, |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 229 | .wq = __WAIT_QUEUE_HEAD_INITIALIZER(cpu_hotplug.wq), |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 230 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 231 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
Joonas Lahtinen | a705e07 | 2016-10-12 13:18:56 +0300 | [diff] [blame] | 232 | .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] | 233 | #endif |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 234 | }; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 235 | |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 236 | /* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */ |
| 237 | #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] | 238 | #define cpuhp_lock_acquire_tryread() \ |
| 239 | lock_map_acquire_tryread(&cpu_hotplug.dep_map) |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 240 | #define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map) |
| 241 | #define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map) |
| 242 | |
Prateek Sood | e9e7b75 | 2017-09-08 13:10:55 +0530 | [diff] [blame] | 243 | void cpu_hotplug_mutex_held(void) |
| 244 | { |
| 245 | lockdep_assert_held(&cpu_hotplug.lock); |
| 246 | } |
| 247 | EXPORT_SYMBOL(cpu_hotplug_mutex_held); |
Paul E. McKenney | 62db99f | 2014-10-22 14:51:49 -0700 | [diff] [blame] | 248 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 249 | void get_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 250 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 251 | might_sleep(); |
| 252 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 253 | return; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 254 | cpuhp_lock_acquire_read(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 255 | mutex_lock(&cpu_hotplug.lock); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 256 | atomic_inc(&cpu_hotplug.refcount); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 257 | mutex_unlock(&cpu_hotplug.lock); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 258 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 259 | EXPORT_SYMBOL_GPL(get_online_cpus); |
Ashok Raj | 90d45d1 | 2005-11-08 21:34:24 -0800 | [diff] [blame] | 260 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 261 | void put_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 262 | { |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 263 | int refcount; |
| 264 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 265 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 266 | return; |
Srivatsa S. Bhat | 075663d | 2012-10-08 16:28:20 -0700 | [diff] [blame] | 267 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 268 | refcount = atomic_dec_return(&cpu_hotplug.refcount); |
| 269 | if (WARN_ON(refcount < 0)) /* try to fix things up */ |
| 270 | atomic_inc(&cpu_hotplug.refcount); |
Srivatsa S. Bhat | 075663d | 2012-10-08 16:28:20 -0700 | [diff] [blame] | 271 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 272 | if (refcount <= 0 && waitqueue_active(&cpu_hotplug.wq)) |
| 273 | wake_up(&cpu_hotplug.wq); |
| 274 | |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 275 | cpuhp_lock_release(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 276 | |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 277 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 278 | EXPORT_SYMBOL_GPL(put_online_cpus); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 279 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 280 | /* |
| 281 | * This ensures that the hotplug operation can begin only when the |
| 282 | * refcount goes to zero. |
| 283 | * |
| 284 | * Note that during a cpu-hotplug operation, the new readers, if any, |
| 285 | * will be blocked by the cpu_hotplug.lock |
| 286 | * |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 287 | * Since cpu_hotplug_begin() is always called after invoking |
| 288 | * 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] | 289 | * |
| 290 | * Note that theoretically, there is a possibility of a livelock: |
| 291 | * - Refcount goes to zero, last reader wakes up the sleeping |
| 292 | * writer. |
| 293 | * - Last reader unlocks the cpu_hotplug.lock. |
| 294 | * - A new reader arrives at this moment, bumps up the refcount. |
| 295 | * - The writer acquires the cpu_hotplug.lock finds the refcount |
| 296 | * non zero and goes to sleep again. |
| 297 | * |
| 298 | * However, this is very difficult to achieve in practice since |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 299 | * 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] | 300 | * |
| 301 | */ |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 302 | void cpu_hotplug_begin(void) |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 303 | { |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 304 | DEFINE_WAIT(wait); |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 305 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 306 | cpu_hotplug.active_writer = current; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 307 | cpuhp_lock_acquire(); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 308 | |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 309 | for (;;) { |
| 310 | mutex_lock(&cpu_hotplug.lock); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 311 | prepare_to_wait(&cpu_hotplug.wq, &wait, TASK_UNINTERRUPTIBLE); |
| 312 | if (likely(!atomic_read(&cpu_hotplug.refcount))) |
| 313 | break; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 314 | mutex_unlock(&cpu_hotplug.lock); |
| 315 | schedule(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 316 | } |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 317 | finish_wait(&cpu_hotplug.wq, &wait); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 318 | } |
| 319 | |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 320 | void cpu_hotplug_done(void) |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 321 | { |
| 322 | cpu_hotplug.active_writer = NULL; |
| 323 | mutex_unlock(&cpu_hotplug.lock); |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 324 | cpuhp_lock_release(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 325 | } |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 326 | |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 327 | /* |
| 328 | * Wait for currently running CPU hotplug operations to complete (if any) and |
| 329 | * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects |
| 330 | * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the |
| 331 | * hotplug path before performing hotplug operations. So acquiring that lock |
| 332 | * guarantees mutual exclusion from any currently running hotplug operations. |
| 333 | */ |
| 334 | void cpu_hotplug_disable(void) |
| 335 | { |
| 336 | cpu_maps_update_begin(); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 337 | cpu_hotplug_disabled++; |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 338 | cpu_maps_update_done(); |
| 339 | } |
Vitaly Kuznetsov | 32145c4 | 2015-08-05 00:52:47 -0700 | [diff] [blame] | 340 | EXPORT_SYMBOL_GPL(cpu_hotplug_disable); |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 341 | |
Lianwei Wang | 01b4115 | 2016-06-09 23:43:28 -0700 | [diff] [blame] | 342 | static void __cpu_hotplug_enable(void) |
| 343 | { |
| 344 | if (WARN_ONCE(!cpu_hotplug_disabled, "Unbalanced cpu hotplug enable\n")) |
| 345 | return; |
| 346 | cpu_hotplug_disabled--; |
| 347 | } |
| 348 | |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 349 | void cpu_hotplug_enable(void) |
| 350 | { |
| 351 | cpu_maps_update_begin(); |
Lianwei Wang | 01b4115 | 2016-06-09 23:43:28 -0700 | [diff] [blame] | 352 | __cpu_hotplug_enable(); |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 353 | cpu_maps_update_done(); |
| 354 | } |
Vitaly Kuznetsov | 32145c4 | 2015-08-05 00:52:47 -0700 | [diff] [blame] | 355 | EXPORT_SYMBOL_GPL(cpu_hotplug_enable); |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 356 | #endif /* CONFIG_HOTPLUG_CPU */ |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 357 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | /* Need to know about CPUs going up/down? */ |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 359 | int register_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | { |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 361 | int ret; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 362 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 363 | ret = raw_notifier_chain_register(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 364 | cpu_maps_update_done(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 365 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | } |
Chandra Seetharaman | 65edc68 | 2006-06-27 02:54:08 -0700 | [diff] [blame] | 367 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 368 | int __register_cpu_notifier(struct notifier_block *nb) |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 369 | { |
| 370 | return raw_notifier_chain_register(&cpu_chain, nb); |
| 371 | } |
| 372 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 373 | 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] | 374 | int *nr_calls) |
| 375 | { |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 376 | unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0; |
| 377 | void *hcpu = (void *)(long)cpu; |
| 378 | |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 379 | int ret; |
| 380 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 381 | 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] | 382 | nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 383 | |
| 384 | return notifier_to_errno(ret); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 385 | } |
| 386 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 387 | static int cpu_notify(unsigned long val, unsigned int cpu) |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 388 | { |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 389 | return __cpu_notify(val, cpu, -1, NULL); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 390 | } |
| 391 | |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 392 | static void cpu_notify_nofail(unsigned long val, unsigned int cpu) |
| 393 | { |
| 394 | BUG_ON(cpu_notify(val, cpu)); |
| 395 | } |
| 396 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 397 | /* Notifier wrappers for transitioning to state machine */ |
| 398 | static int notify_prepare(unsigned int cpu) |
| 399 | { |
| 400 | int nr_calls = 0; |
| 401 | int ret; |
| 402 | |
| 403 | ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls); |
| 404 | if (ret) { |
| 405 | nr_calls--; |
| 406 | printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", |
| 407 | __func__, cpu); |
| 408 | __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL); |
| 409 | } |
| 410 | return ret; |
| 411 | } |
| 412 | |
| 413 | static int notify_online(unsigned int cpu) |
| 414 | { |
| 415 | cpu_notify(CPU_ONLINE, cpu); |
| 416 | return 0; |
| 417 | } |
Thomas Gleixner | ceb354b | 2017-07-04 22:20:23 +0200 | [diff] [blame] | 418 | static void __cpuhp_kick_ap_work(struct cpuhp_cpu_state *st); |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 419 | |
Thomas Gleixner | 7b4e4b1 | 2017-07-04 22:20:23 +0200 | [diff] [blame] | 420 | static void __cpuhp_kick_ap_work(struct cpuhp_cpu_state *st); |
| 421 | |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 422 | static int bringup_wait_for_ap(unsigned int cpu) |
| 423 | { |
| 424 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 425 | |
Thomas Gleixner | ceb354b | 2017-07-04 22:20:23 +0200 | [diff] [blame] | 426 | /* Wait for the CPU to reach CPUHP_AP_ONLINE_IDLE */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 427 | wait_for_completion(&st->done); |
Thomas Gleixner | 6b3d13f | 2017-07-11 22:06:24 +0200 | [diff] [blame] | 428 | if (WARN_ON_ONCE((!cpu_online(cpu)))) |
| 429 | return -ECANCELED; |
Thomas Gleixner | ceb354b | 2017-07-04 22:20:23 +0200 | [diff] [blame] | 430 | |
| 431 | /* Unpark the stopper thread and the hotplug thread of the target cpu */ |
| 432 | stop_machine_unpark(cpu); |
| 433 | kthread_unpark(st->thread); |
| 434 | |
| 435 | /* Should we go further up ? */ |
| 436 | if (st->target > CPUHP_AP_ONLINE_IDLE) { |
| 437 | __cpuhp_kick_ap_work(st); |
| 438 | wait_for_completion(&st->done); |
| 439 | } |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 440 | return st->result; |
| 441 | } |
| 442 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 443 | static int bringup_cpu(unsigned int cpu) |
| 444 | { |
| 445 | struct task_struct *idle = idle_thread_get(cpu); |
| 446 | int ret; |
| 447 | |
Boris Ostrovsky | aa87717 | 2016-08-03 13:22:28 -0400 | [diff] [blame] | 448 | /* |
| 449 | * Some architectures have to walk the irq descriptors to |
| 450 | * setup the vector space for the cpu which comes online. |
| 451 | * Prevent irq alloc/free across the bringup. |
| 452 | */ |
| 453 | irq_lock_sparse(); |
| 454 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 455 | /* Arch-specific enabling code. */ |
| 456 | ret = __cpu_up(cpu, idle); |
Boris Ostrovsky | aa87717 | 2016-08-03 13:22:28 -0400 | [diff] [blame] | 457 | irq_unlock_sparse(); |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 458 | if (ret) { |
| 459 | cpu_notify(CPU_UP_CANCELED, cpu); |
| 460 | return ret; |
| 461 | } |
Thomas Gleixner | ceb354b | 2017-07-04 22:20:23 +0200 | [diff] [blame] | 462 | return bringup_wait_for_ap(cpu); |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 463 | } |
| 464 | |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 465 | /* |
| 466 | * Hotplug state machine related functions |
| 467 | */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 468 | 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] | 469 | { |
| 470 | for (st->state++; st->state < st->target; st->state++) { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 471 | struct cpuhp_step *step = cpuhp_get_step(st->state); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 472 | |
| 473 | if (!step->skip_onerr) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 474 | cpuhp_invoke_callback(cpu, st->state, true, NULL); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 475 | } |
| 476 | } |
| 477 | |
| 478 | 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] | 479 | enum cpuhp_state target) |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 480 | { |
| 481 | enum cpuhp_state prev_state = st->state; |
| 482 | int ret = 0; |
| 483 | |
| 484 | for (; st->state > target; st->state--) { |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 485 | ret = cpuhp_invoke_callback(cpu, st->state, false, NULL); |
Channagoud Kadabi | bd019ce | 2017-06-19 17:14:52 -0700 | [diff] [blame] | 486 | BUG_ON(ret && st->state < CPUHP_AP_IDLE_DEAD); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 487 | if (ret) { |
| 488 | st->target = prev_state; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 489 | undo_cpu_down(cpu, st); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 490 | break; |
| 491 | } |
| 492 | } |
| 493 | return ret; |
| 494 | } |
| 495 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 496 | 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] | 497 | { |
| 498 | for (st->state--; st->state > st->target; st->state--) { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 499 | struct cpuhp_step *step = cpuhp_get_step(st->state); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 500 | |
| 501 | if (!step->skip_onerr) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 502 | cpuhp_invoke_callback(cpu, st->state, false, NULL); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 503 | } |
| 504 | } |
| 505 | |
| 506 | 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] | 507 | enum cpuhp_state target) |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 508 | { |
| 509 | enum cpuhp_state prev_state = st->state; |
| 510 | int ret = 0; |
| 511 | |
| 512 | while (st->state < target) { |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 513 | st->state++; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 514 | ret = cpuhp_invoke_callback(cpu, st->state, true, NULL); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 515 | if (ret) { |
| 516 | st->target = prev_state; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 517 | undo_cpu_up(cpu, st); |
Channagoud Kadabi | 5ec3ec1 | 2017-06-20 15:01:40 -0700 | [diff] [blame] | 518 | cpu_notify(CPU_UP_CANCELED, cpu); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 519 | break; |
| 520 | } |
| 521 | } |
| 522 | return ret; |
| 523 | } |
| 524 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 525 | /* |
| 526 | * The cpu hotplug threads manage the bringup and teardown of the cpus |
| 527 | */ |
| 528 | static void cpuhp_create(unsigned int cpu) |
| 529 | { |
| 530 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 531 | |
| 532 | init_completion(&st->done); |
| 533 | } |
| 534 | |
| 535 | static int cpuhp_should_run(unsigned int cpu) |
| 536 | { |
| 537 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 538 | |
| 539 | return st->should_run; |
| 540 | } |
| 541 | |
| 542 | /* Execute the teardown callbacks. Used to be CPU_DOWN_PREPARE */ |
| 543 | static int cpuhp_ap_offline(unsigned int cpu, struct cpuhp_cpu_state *st) |
| 544 | { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 545 | enum cpuhp_state target = max((int)st->target, CPUHP_TEARDOWN_CPU); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 546 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 547 | return cpuhp_down_callbacks(cpu, st, target); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 548 | } |
| 549 | |
| 550 | /* Execute the online startup callbacks. Used to be CPU_ONLINE */ |
| 551 | static int cpuhp_ap_online(unsigned int cpu, struct cpuhp_cpu_state *st) |
| 552 | { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 553 | return cpuhp_up_callbacks(cpu, st, st->target); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 554 | } |
| 555 | |
| 556 | /* |
| 557 | * Execute teardown/startup callbacks on the plugged cpu. Also used to invoke |
| 558 | * callbacks when a state gets [un]installed at runtime. |
| 559 | */ |
| 560 | static void cpuhp_thread_fun(unsigned int cpu) |
| 561 | { |
| 562 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 563 | int ret = 0; |
| 564 | |
| 565 | /* |
| 566 | * Paired with the mb() in cpuhp_kick_ap_work and |
| 567 | * cpuhp_invoke_ap_callback, so the work set is consistent visible. |
| 568 | */ |
| 569 | smp_mb(); |
| 570 | if (!st->should_run) |
| 571 | return; |
| 572 | |
| 573 | st->should_run = false; |
| 574 | |
| 575 | /* Single callback invocation for [un]install ? */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 576 | if (st->single) { |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 577 | if (st->cb_state < CPUHP_AP_ONLINE) { |
| 578 | local_irq_disable(); |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 579 | ret = cpuhp_invoke_callback(cpu, st->cb_state, |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 580 | st->bringup, st->node); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 581 | local_irq_enable(); |
| 582 | } else { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 583 | ret = cpuhp_invoke_callback(cpu, st->cb_state, |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 584 | st->bringup, st->node); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 585 | } |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 586 | } else if (st->rollback) { |
| 587 | BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE); |
| 588 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 589 | undo_cpu_down(cpu, st); |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 590 | /* |
| 591 | * This is a momentary workaround to keep the notifier users |
| 592 | * happy. Will go away once we got rid of the notifiers. |
| 593 | */ |
| 594 | cpu_notify_nofail(CPU_DOWN_FAILED, cpu); |
| 595 | st->rollback = false; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 596 | } else { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 597 | /* Cannot happen .... */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 598 | BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 599 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 600 | /* Regular hotplug work */ |
| 601 | if (st->state < st->target) |
| 602 | ret = cpuhp_ap_online(cpu, st); |
| 603 | else if (st->state > st->target) |
| 604 | ret = cpuhp_ap_offline(cpu, st); |
| 605 | } |
| 606 | st->result = ret; |
| 607 | complete(&st->done); |
| 608 | } |
| 609 | |
| 610 | /* Invoke a single callback on a remote cpu */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 611 | static int |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 612 | cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state, bool bringup, |
| 613 | struct hlist_node *node) |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 614 | { |
| 615 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 616 | |
| 617 | if (!cpu_online(cpu)) |
| 618 | return 0; |
| 619 | |
Thomas Gleixner | 6a4e245 | 2016-07-13 17:16:03 +0000 | [diff] [blame] | 620 | /* |
| 621 | * If we are up and running, use the hotplug thread. For early calls |
| 622 | * we invoke the thread function directly. |
| 623 | */ |
| 624 | if (!st->thread) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 625 | return cpuhp_invoke_callback(cpu, state, bringup, node); |
Thomas Gleixner | 6a4e245 | 2016-07-13 17:16:03 +0000 | [diff] [blame] | 626 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 627 | st->cb_state = state; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 628 | st->single = true; |
| 629 | st->bringup = bringup; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 630 | st->node = node; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 631 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 632 | /* |
| 633 | * Make sure the above stores are visible before should_run becomes |
| 634 | * true. Paired with the mb() above in cpuhp_thread_fun() |
| 635 | */ |
| 636 | smp_mb(); |
| 637 | st->should_run = true; |
| 638 | wake_up_process(st->thread); |
| 639 | wait_for_completion(&st->done); |
| 640 | return st->result; |
| 641 | } |
| 642 | |
| 643 | /* Regular hotplug invocation of the AP hotplug thread */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 644 | static void __cpuhp_kick_ap_work(struct cpuhp_cpu_state *st) |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 645 | { |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 646 | st->result = 0; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 647 | st->single = false; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 648 | /* |
| 649 | * Make sure the above stores are visible before should_run becomes |
| 650 | * true. Paired with the mb() above in cpuhp_thread_fun() |
| 651 | */ |
| 652 | smp_mb(); |
| 653 | st->should_run = true; |
| 654 | wake_up_process(st->thread); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 655 | } |
| 656 | |
| 657 | static int cpuhp_kick_ap_work(unsigned int cpu) |
| 658 | { |
| 659 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 660 | enum cpuhp_state state = st->state; |
| 661 | |
| 662 | trace_cpuhp_enter(cpu, st->target, state, cpuhp_kick_ap_work); |
| 663 | __cpuhp_kick_ap_work(st); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 664 | wait_for_completion(&st->done); |
| 665 | trace_cpuhp_exit(cpu, st->state, state, st->result); |
| 666 | return st->result; |
| 667 | } |
| 668 | |
| 669 | static struct smp_hotplug_thread cpuhp_threads = { |
| 670 | .store = &cpuhp_state.thread, |
| 671 | .create = &cpuhp_create, |
| 672 | .thread_should_run = cpuhp_should_run, |
| 673 | .thread_fn = cpuhp_thread_fun, |
| 674 | .thread_comm = "cpuhp/%u", |
| 675 | .selfparking = true, |
| 676 | }; |
| 677 | |
| 678 | void __init cpuhp_threads_init(void) |
| 679 | { |
| 680 | BUG_ON(smpboot_register_percpu_thread(&cpuhp_threads)); |
| 681 | kthread_unpark(this_cpu_read(cpuhp_state.thread)); |
| 682 | } |
| 683 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 684 | EXPORT_SYMBOL(register_cpu_notifier); |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 685 | EXPORT_SYMBOL(__register_cpu_notifier); |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 686 | void unregister_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 688 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 689 | raw_notifier_chain_unregister(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 690 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | } |
| 692 | EXPORT_SYMBOL(unregister_cpu_notifier); |
| 693 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 694 | void __unregister_cpu_notifier(struct notifier_block *nb) |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 695 | { |
| 696 | raw_notifier_chain_unregister(&cpu_chain, nb); |
| 697 | } |
| 698 | EXPORT_SYMBOL(__unregister_cpu_notifier); |
| 699 | |
Michal Hocko | 56eaecc | 2016-12-07 14:54:38 +0100 | [diff] [blame] | 700 | #ifdef CONFIG_HOTPLUG_CPU |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 701 | /** |
| 702 | * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU |
| 703 | * @cpu: a CPU id |
| 704 | * |
| 705 | * This function walks all processes, finds a valid mm struct for each one and |
| 706 | * then clears a corresponding bit in mm's cpumask. While this all sounds |
| 707 | * trivial, there are various non-obvious corner cases, which this function |
| 708 | * tries to solve in a safe manner. |
| 709 | * |
| 710 | * Also note that the function uses a somewhat relaxed locking scheme, so it may |
| 711 | * be called only for an already offlined CPU. |
| 712 | */ |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 713 | void clear_tasks_mm_cpumask(int cpu) |
| 714 | { |
| 715 | struct task_struct *p; |
| 716 | |
| 717 | /* |
| 718 | * This function is called after the cpu is taken down and marked |
| 719 | * offline, so its not like new tasks will ever get this cpu set in |
| 720 | * their mm mask. -- Peter Zijlstra |
| 721 | * Thus, we may use rcu_read_lock() here, instead of grabbing |
| 722 | * full-fledged tasklist_lock. |
| 723 | */ |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 724 | WARN_ON(cpu_online(cpu)); |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 725 | rcu_read_lock(); |
| 726 | for_each_process(p) { |
| 727 | struct task_struct *t; |
| 728 | |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 729 | /* |
| 730 | * Main thread might exit, but other threads may still have |
| 731 | * a valid mm. Find one. |
| 732 | */ |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 733 | t = find_lock_task_mm(p); |
| 734 | if (!t) |
| 735 | continue; |
| 736 | cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); |
| 737 | task_unlock(t); |
| 738 | } |
| 739 | rcu_read_unlock(); |
| 740 | } |
| 741 | |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 742 | static inline void check_for_tasks(int dead_cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | { |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 744 | struct task_struct *g, *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 745 | |
Oleg Nesterov | a75a606 | 2015-09-10 15:07:50 +0200 | [diff] [blame] | 746 | read_lock(&tasklist_lock); |
| 747 | for_each_process_thread(g, p) { |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 748 | if (!p->on_rq) |
| 749 | continue; |
| 750 | /* |
| 751 | * We do the check with unlocked task_rq(p)->lock. |
| 752 | * Order the reading to do not warn about a task, |
| 753 | * which was running on this cpu in the past, and |
| 754 | * it's just been woken on another cpu. |
| 755 | */ |
| 756 | rmb(); |
| 757 | if (task_cpu(p) != dead_cpu) |
| 758 | continue; |
| 759 | |
| 760 | pr_warn("Task %s (pid=%d) is on cpu %d (state=%ld, flags=%x)\n", |
| 761 | p->comm, task_pid_nr(p), dead_cpu, p->state, p->flags); |
Oleg Nesterov | a75a606 | 2015-09-10 15:07:50 +0200 | [diff] [blame] | 762 | } |
| 763 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | } |
| 765 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 766 | static int notify_down_prepare(unsigned int cpu) |
| 767 | { |
| 768 | int err, nr_calls = 0; |
| 769 | |
| 770 | err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls); |
| 771 | if (err) { |
| 772 | nr_calls--; |
| 773 | __cpu_notify(CPU_DOWN_FAILED, cpu, nr_calls, NULL); |
| 774 | pr_warn("%s: attempt to take down CPU %u failed\n", |
| 775 | __func__, cpu); |
| 776 | } |
| 777 | return err; |
| 778 | } |
| 779 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 780 | /* Take this CPU down. */ |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 781 | static int take_cpu_down(void *_param) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | { |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 783 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 784 | enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE); |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 785 | int err, cpu = smp_processor_id(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | /* Ensure this CPU doesn't handle any more interrupts. */ |
| 788 | err = __cpu_disable(); |
| 789 | if (err < 0) |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 790 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 791 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 792 | /* |
| 793 | * We get here while we are in CPUHP_TEARDOWN_CPU state and we must not |
| 794 | * do this step again. |
| 795 | */ |
| 796 | WARN_ON(st->state != CPUHP_TEARDOWN_CPU); |
| 797 | st->state--; |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 798 | /* Invoke the former CPU_DYING callbacks */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 799 | for (; st->state > target; st->state--) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 800 | cpuhp_invoke_callback(cpu, st->state, false, NULL); |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 801 | |
Thomas Gleixner | 52c063d | 2015-04-03 02:37:24 +0200 | [diff] [blame] | 802 | /* Give up timekeeping duties */ |
| 803 | tick_handover_do_timer(); |
Thomas Gleixner | 14e568e | 2013-01-31 12:11:14 +0000 | [diff] [blame] | 804 | /* Park the stopper thread */ |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 805 | stop_machine_park(cpu); |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 806 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 807 | } |
| 808 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 809 | static int takedown_cpu(unsigned int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | { |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 811 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 812 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | |
Thomas Gleixner | 2a58c52 | 2016-03-10 20:42:08 +0100 | [diff] [blame] | 814 | /* Park the smpboot threads */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 815 | kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread); |
Thomas Gleixner | 2a58c52 | 2016-03-10 20:42:08 +0100 | [diff] [blame] | 816 | smpboot_park_threads(cpu); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 817 | |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 818 | /* |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 819 | * Prevent irq alloc/free while the dying cpu reorganizes the |
| 820 | * interrupt affinities. |
| 821 | */ |
| 822 | irq_lock_sparse(); |
| 823 | |
| 824 | /* |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 825 | * So now all preempt/rcu users must observe !cpu_active(). |
| 826 | */ |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 827 | err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu)); |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 828 | if (err) { |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 829 | /* CPU refused to die */ |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 830 | irq_unlock_sparse(); |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 831 | /* Unpark the hotplug thread so we can rollback there */ |
| 832 | kthread_unpark(per_cpu_ptr(&cpuhp_state, cpu)->thread); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 833 | return err; |
Satoru Takeuchi | 8fa1d7d | 2006-10-28 10:38:57 -0700 | [diff] [blame] | 834 | } |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 835 | BUG_ON(cpu_online(cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 836 | |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 837 | /* |
Thomas Gleixner | ee1e714 | 2016-08-18 14:57:16 +0200 | [diff] [blame] | 838 | * The CPUHP_AP_SCHED_MIGRATE_DYING callback will have removed all |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 839 | * runnable tasks from the cpu, there's only the idle task left now |
| 840 | * that the migration thread is done doing the stop_machine thing. |
Peter Zijlstra | 51a96c7 | 2010-11-19 20:37:53 +0100 | [diff] [blame] | 841 | * |
| 842 | * Wait for the stop thread to go away. |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 843 | */ |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 844 | wait_for_completion(&st->done); |
| 845 | BUG_ON(st->state != CPUHP_AP_IDLE_DEAD); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 846 | |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 847 | /* Interrupts are moved away from the dying cpu, reenable alloc/free */ |
| 848 | irq_unlock_sparse(); |
| 849 | |
Preeti U Murthy | 345527b | 2015-03-30 14:59:19 +0530 | [diff] [blame] | 850 | hotplug_cpu__broadcast_tick_pull(cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 851 | /* This actually kills the CPU. */ |
| 852 | __cpu_die(cpu); |
| 853 | |
Thomas Gleixner | a49b116 | 2015-04-03 02:38:05 +0200 | [diff] [blame] | 854 | tick_cleanup_dead_cpu(cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 855 | return 0; |
| 856 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 857 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 858 | static int notify_dead(unsigned int cpu) |
| 859 | { |
| 860 | cpu_notify_nofail(CPU_DEAD, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 861 | check_for_tasks(cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 862 | return 0; |
| 863 | } |
| 864 | |
Thomas Gleixner | 71f87b2 | 2016-03-03 10:52:10 +0100 | [diff] [blame] | 865 | static void cpuhp_complete_idle_dead(void *arg) |
| 866 | { |
| 867 | struct cpuhp_cpu_state *st = arg; |
| 868 | |
| 869 | complete(&st->done); |
| 870 | } |
| 871 | |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 872 | void cpuhp_report_idle_dead(void) |
| 873 | { |
| 874 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 875 | |
| 876 | BUG_ON(st->state != CPUHP_AP_OFFLINE); |
Thomas Gleixner | 27d50c7 | 2016-02-26 18:43:44 +0000 | [diff] [blame] | 877 | rcu_report_dead(smp_processor_id()); |
Thomas Gleixner | 71f87b2 | 2016-03-03 10:52:10 +0100 | [diff] [blame] | 878 | st->state = CPUHP_AP_IDLE_DEAD; |
| 879 | /* |
| 880 | * We cannot call complete after rcu_report_dead() so we delegate it |
| 881 | * to an online cpu. |
| 882 | */ |
| 883 | smp_call_function_single(cpumask_first(cpu_online_mask), |
| 884 | cpuhp_complete_idle_dead, st, 0); |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 885 | } |
| 886 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 887 | #else |
| 888 | #define notify_down_prepare NULL |
| 889 | #define takedown_cpu NULL |
| 890 | #define notify_dead NULL |
| 891 | #endif |
| 892 | |
| 893 | #ifdef CONFIG_HOTPLUG_CPU |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 894 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 895 | /* Requires cpu_add_remove_lock to be held */ |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 896 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, |
| 897 | enum cpuhp_state target) |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 898 | { |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 899 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 900 | int prev_state, ret = 0; |
| 901 | bool hasdied = false; |
Prasad Sodagudi | 0a29343 | 2017-10-13 15:28:58 -0700 | [diff] [blame] | 902 | u64 start_time = 0; |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 903 | |
| 904 | if (num_online_cpus() == 1) |
| 905 | return -EBUSY; |
| 906 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 907 | if (!cpu_present(cpu)) |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 908 | return -EINVAL; |
| 909 | |
Pavankumar Kondeti | 68435b0 | 2017-06-29 16:17:55 +0530 | [diff] [blame] | 910 | if (!tasks_frozen && !cpu_isolated(cpu) && num_online_uniso_cpus() == 1) |
| 911 | return -EBUSY; |
| 912 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 913 | cpu_hotplug_begin(); |
Prasad Sodagudi | 0a29343 | 2017-10-13 15:28:58 -0700 | [diff] [blame] | 914 | if (trace_cpuhp_latency_enabled()) |
| 915 | start_time = sched_clock(); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 916 | |
| 917 | cpuhp_tasks_frozen = tasks_frozen; |
| 918 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 919 | prev_state = st->state; |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 920 | st->target = target; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 921 | /* |
| 922 | * If the current CPU state is in the range of the AP hotplug thread, |
| 923 | * then we need to kick the thread. |
| 924 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 925 | if (st->state > CPUHP_TEARDOWN_CPU) { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 926 | ret = cpuhp_kick_ap_work(cpu); |
| 927 | /* |
| 928 | * The AP side has done the error rollback already. Just |
| 929 | * return the error code.. |
| 930 | */ |
| 931 | if (ret) |
| 932 | goto out; |
| 933 | |
| 934 | /* |
| 935 | * We might have stopped still in the range of the AP hotplug |
| 936 | * thread. Nothing to do anymore. |
| 937 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 938 | if (st->state > CPUHP_TEARDOWN_CPU) |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 939 | goto out; |
| 940 | } |
| 941 | /* |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 942 | * The AP brought itself down to CPUHP_TEARDOWN_CPU. So we need |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 943 | * to do the further cleanups. |
| 944 | */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 945 | ret = cpuhp_down_callbacks(cpu, st, target); |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 946 | if (ret && st->state > CPUHP_TEARDOWN_CPU && st->state < prev_state) { |
| 947 | st->target = prev_state; |
| 948 | st->rollback = true; |
| 949 | cpuhp_kick_ap_work(cpu); |
| 950 | } |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 951 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 952 | hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 953 | out: |
Prasad Sodagudi | 0a29343 | 2017-10-13 15:28:58 -0700 | [diff] [blame] | 954 | trace_cpuhp_latency(cpu, 0, start_time, ret); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 955 | cpu_hotplug_done(); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 956 | /* This post dead nonsense must die */ |
| 957 | if (!ret && hasdied) |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 958 | cpu_notify_nofail(CPU_POST_DEAD, cpu); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 959 | return ret; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 960 | } |
| 961 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 962 | 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] | 963 | { |
Heiko Carstens | 9ea09af | 2008-12-22 12:36:30 +0100 | [diff] [blame] | 964 | int err; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 965 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 966 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 967 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 968 | if (cpu_hotplug_disabled) { |
| 969 | err = -EBUSY; |
| 970 | goto out; |
| 971 | } |
| 972 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 973 | err = _cpu_down(cpu, 0, target); |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 974 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 975 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 976 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 977 | return err; |
| 978 | } |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 979 | int cpu_down(unsigned int cpu) |
| 980 | { |
| 981 | return do_cpu_down(cpu, CPUHP_OFFLINE); |
| 982 | } |
Zhang Rui | b62b8ef | 2008-04-29 02:35:56 -0400 | [diff] [blame] | 983 | EXPORT_SYMBOL(cpu_down); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 984 | #endif /*CONFIG_HOTPLUG_CPU*/ |
| 985 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 986 | /** |
Thomas Gleixner | ee1e714 | 2016-08-18 14:57:16 +0200 | [diff] [blame] | 987 | * notify_cpu_starting(cpu) - Invoke the callbacks on the starting CPU |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 988 | * @cpu: cpu that just started |
| 989 | * |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 990 | * It must be called by the arch code on the new cpu, before the new cpu |
| 991 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). |
| 992 | */ |
| 993 | void notify_cpu_starting(unsigned int cpu) |
| 994 | { |
| 995 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 996 | enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE); |
| 997 | |
Sebastian Andrzej Siewior | 0c6d457 | 2016-08-17 14:21:04 +0200 | [diff] [blame] | 998 | rcu_cpu_starting(cpu); /* Enables RCU usage on this CPU. */ |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 999 | while (st->state < target) { |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1000 | st->state++; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1001 | cpuhp_invoke_callback(cpu, st->state, true, NULL); |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1002 | } |
| 1003 | } |
| 1004 | |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 1005 | /* |
Thomas Gleixner | ceb354b | 2017-07-04 22:20:23 +0200 | [diff] [blame] | 1006 | * Called from the idle task. Wake up the controlling task which brings the |
| 1007 | * stopper and the hotplug thread of the upcoming CPU up and then delegates |
| 1008 | * the rest of the online bringup to the hotplug thread. |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 1009 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 1010 | void cpuhp_online_idle(enum cpuhp_state state) |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 1011 | { |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 1012 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 1013 | |
| 1014 | /* Happens for the boot cpu */ |
| 1015 | if (state != CPUHP_AP_ONLINE_IDLE) |
| 1016 | return; |
| 1017 | |
| 1018 | st->state = CPUHP_AP_ONLINE_IDLE; |
Thomas Gleixner | ceb354b | 2017-07-04 22:20:23 +0200 | [diff] [blame] | 1019 | complete(&st->done); |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 1020 | } |
| 1021 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1022 | /* Requires cpu_add_remove_lock to be held */ |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1023 | 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] | 1024 | { |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1025 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 1026 | struct task_struct *idle; |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 1027 | int ret = 0; |
Prasad Sodagudi | 0a29343 | 2017-10-13 15:28:58 -0700 | [diff] [blame] | 1028 | u64 start_time = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1029 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1030 | cpu_hotplug_begin(); |
Prasad Sodagudi | 0a29343 | 2017-10-13 15:28:58 -0700 | [diff] [blame] | 1031 | if (trace_cpuhp_latency_enabled()) |
| 1032 | start_time = sched_clock(); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 1033 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1034 | if (!cpu_present(cpu)) { |
Yasuaki Ishimatsu | 5e5041f | 2012-10-23 01:30:54 +0200 | [diff] [blame] | 1035 | ret = -EINVAL; |
| 1036 | goto out; |
| 1037 | } |
| 1038 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1039 | /* |
| 1040 | * The caller of do_cpu_up might have raced with another |
| 1041 | * caller. Ignore it for now. |
| 1042 | */ |
| 1043 | if (st->state >= target) |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 1044 | goto out; |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1045 | |
| 1046 | if (st->state == CPUHP_OFFLINE) { |
| 1047 | /* Let it fail before we try to bring the cpu up */ |
| 1048 | idle = idle_thread_get(cpu); |
| 1049 | if (IS_ERR(idle)) { |
| 1050 | ret = PTR_ERR(idle); |
| 1051 | goto out; |
| 1052 | } |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 1053 | } |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 1054 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 1055 | cpuhp_tasks_frozen = tasks_frozen; |
| 1056 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1057 | st->target = target; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1058 | /* |
| 1059 | * If the current CPU state is in the range of the AP hotplug thread, |
| 1060 | * then we need to kick the thread once more. |
| 1061 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 1062 | if (st->state > CPUHP_BRINGUP_CPU) { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1063 | ret = cpuhp_kick_ap_work(cpu); |
| 1064 | /* |
| 1065 | * The AP side has done the error rollback already. Just |
| 1066 | * return the error code.. |
| 1067 | */ |
| 1068 | if (ret) |
| 1069 | goto out; |
| 1070 | } |
| 1071 | |
| 1072 | /* |
| 1073 | * 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] | 1074 | * CPUHP_BRINGUP_CPU. After that the AP hotplug thread is |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1075 | * responsible for bringing it up to the target state. |
| 1076 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 1077 | target = min((int)target, CPUHP_BRINGUP_CPU); |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 1078 | ret = cpuhp_up_callbacks(cpu, st, target); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 1079 | out: |
Prasad Sodagudi | 0a29343 | 2017-10-13 15:28:58 -0700 | [diff] [blame] | 1080 | trace_cpuhp_latency(cpu, 1, start_time, ret); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1081 | cpu_hotplug_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1082 | return ret; |
| 1083 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1084 | |
Syed Rameez Mustafa | b305880 | 2016-12-16 11:59:05 -0800 | [diff] [blame] | 1085 | static int switch_to_rt_policy(void) |
| 1086 | { |
| 1087 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; |
| 1088 | unsigned int policy = current->policy; |
| 1089 | int err; |
| 1090 | |
| 1091 | /* Nobody should be attempting hotplug from these policy contexts. */ |
| 1092 | if (policy == SCHED_BATCH || policy == SCHED_IDLE || |
| 1093 | policy == SCHED_DEADLINE) |
| 1094 | return -EPERM; |
| 1095 | |
| 1096 | if (policy == SCHED_FIFO || policy == SCHED_RR) |
| 1097 | return 1; |
| 1098 | |
| 1099 | /* Only SCHED_NORMAL left. */ |
| 1100 | err = sched_setscheduler_nocheck(current, SCHED_FIFO, ¶m); |
| 1101 | return err; |
| 1102 | |
| 1103 | } |
| 1104 | |
| 1105 | static int switch_to_fair_policy(void) |
| 1106 | { |
| 1107 | struct sched_param param = { .sched_priority = 0 }; |
| 1108 | |
| 1109 | return sched_setscheduler_nocheck(current, SCHED_NORMAL, ¶m); |
| 1110 | } |
| 1111 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1112 | 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] | 1113 | { |
| 1114 | int err = 0; |
Syed Rameez Mustafa | b305880 | 2016-12-16 11:59:05 -0800 | [diff] [blame] | 1115 | int switch_err = 0; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 1116 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1117 | if (!cpu_possible(cpu)) { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1118 | pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n", |
| 1119 | cpu); |
Chen Gong | 87d5e02 | 2010-03-05 13:42:38 -0800 | [diff] [blame] | 1120 | #if defined(CONFIG_IA64) |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1121 | pr_err("please check additional_cpus= boot parameter\n"); |
KAMEZAWA Hiroyuki | 73e753a | 2007-10-18 23:40:47 -0700 | [diff] [blame] | 1122 | #endif |
| 1123 | return -EINVAL; |
| 1124 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1125 | |
Syed Rameez Mustafa | b305880 | 2016-12-16 11:59:05 -0800 | [diff] [blame] | 1126 | switch_err = switch_to_rt_policy(); |
| 1127 | if (switch_err < 0) |
| 1128 | return switch_err; |
| 1129 | |
Toshi Kani | 01b0f19 | 2013-11-12 15:07:25 -0800 | [diff] [blame] | 1130 | err = try_online_node(cpu_to_node(cpu)); |
| 1131 | if (err) |
| 1132 | return err; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 1133 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1134 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1135 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 1136 | if (cpu_hotplug_disabled) { |
| 1137 | err = -EBUSY; |
| 1138 | goto out; |
| 1139 | } |
| 1140 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1141 | err = _cpu_up(cpu, 0, target); |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 1142 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1143 | cpu_maps_update_done(); |
Syed Rameez Mustafa | b305880 | 2016-12-16 11:59:05 -0800 | [diff] [blame] | 1144 | |
| 1145 | if (!switch_err) { |
| 1146 | switch_err = switch_to_fair_policy(); |
Pavankumar Kondeti | 657ad05 | 2017-04-14 14:59:40 +0530 | [diff] [blame] | 1147 | if (switch_err) |
| 1148 | pr_err("Hotplug policy switch err=%d Task %s pid=%d\n", |
| 1149 | switch_err, current->comm, current->pid); |
Syed Rameez Mustafa | b305880 | 2016-12-16 11:59:05 -0800 | [diff] [blame] | 1150 | } |
| 1151 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1152 | return err; |
| 1153 | } |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1154 | |
| 1155 | int cpu_up(unsigned int cpu) |
| 1156 | { |
| 1157 | return do_cpu_up(cpu, CPUHP_ONLINE); |
| 1158 | } |
Paul E. McKenney | a513f6b | 2011-12-11 21:54:45 -0800 | [diff] [blame] | 1159 | EXPORT_SYMBOL_GPL(cpu_up); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1160 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 1161 | #ifdef CONFIG_PM_SLEEP_SMP |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1162 | static cpumask_var_t frozen_cpus; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1163 | |
James Morse | d391e55 | 2016-08-17 13:50:25 +0100 | [diff] [blame] | 1164 | int freeze_secondary_cpus(int primary) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1165 | { |
James Morse | d391e55 | 2016-08-17 13:50:25 +0100 | [diff] [blame] | 1166 | int cpu, error = 0; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1167 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1168 | cpu_maps_update_begin(); |
James Morse | d391e55 | 2016-08-17 13:50:25 +0100 | [diff] [blame] | 1169 | if (!cpu_online(primary)) |
| 1170 | primary = cpumask_first(cpu_online_mask); |
Xiaotian Feng | 9ee349a | 2009-12-16 18:04:32 +0100 | [diff] [blame] | 1171 | /* |
| 1172 | * 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] | 1173 | * with the userspace trying to use the CPU hotplug at the same time |
| 1174 | */ |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1175 | cpumask_clear(frozen_cpus); |
Peter Zijlstra | 6ad4c18 | 2009-11-25 13:31:39 +0100 | [diff] [blame] | 1176 | |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1177 | pr_info("Disabling non-boot CPUs ...\n"); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1178 | for_each_online_cpu(cpu) { |
James Morse | d391e55 | 2016-08-17 13:50:25 +0100 | [diff] [blame] | 1179 | if (cpu == primary) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1180 | continue; |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1181 | trace_suspend_resume(TPS("CPU_OFF"), cpu, true); |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1182 | error = _cpu_down(cpu, 1, CPUHP_OFFLINE); |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1183 | trace_suspend_resume(TPS("CPU_OFF"), cpu, false); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 1184 | if (!error) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1185 | cpumask_set_cpu(cpu, frozen_cpus); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 1186 | else { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1187 | pr_err("Error taking CPU%d down: %d\n", cpu, error); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1188 | break; |
| 1189 | } |
| 1190 | } |
Joseph Cihula | 86886e5 | 2009-06-30 19:31:07 -0700 | [diff] [blame] | 1191 | |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1192 | if (!error) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1193 | BUG_ON(num_online_cpus() > 1); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1194 | else |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1195 | pr_err("Non-boot CPUs are not disabled\n"); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1196 | |
| 1197 | /* |
| 1198 | * Make sure the CPUs won't be enabled by someone else. We need to do |
| 1199 | * this even in case of failure as all disable_nonboot_cpus() users are |
| 1200 | * supposed to do enable_nonboot_cpus() on the failure path. |
| 1201 | */ |
| 1202 | cpu_hotplug_disabled++; |
| 1203 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1204 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1205 | return error; |
| 1206 | } |
| 1207 | |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1208 | void __weak arch_enable_nonboot_cpus_begin(void) |
| 1209 | { |
| 1210 | } |
| 1211 | |
| 1212 | void __weak arch_enable_nonboot_cpus_end(void) |
| 1213 | { |
| 1214 | } |
| 1215 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 1216 | void enable_nonboot_cpus(void) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1217 | { |
| 1218 | int cpu, error; |
Thierry Strudel | 0c3610e | 2016-06-14 17:46:44 -0700 | [diff] [blame] | 1219 | struct device *cpu_device; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1220 | |
| 1221 | /* Allow everyone to use the CPU hotplug again */ |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1222 | cpu_maps_update_begin(); |
Lianwei Wang | 01b4115 | 2016-06-09 23:43:28 -0700 | [diff] [blame] | 1223 | __cpu_hotplug_enable(); |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1224 | if (cpumask_empty(frozen_cpus)) |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 1225 | goto out; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1226 | |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1227 | pr_info("Enabling non-boot CPUs ...\n"); |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1228 | |
| 1229 | arch_enable_nonboot_cpus_begin(); |
| 1230 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1231 | for_each_cpu(cpu, frozen_cpus) { |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1232 | trace_suspend_resume(TPS("CPU_ON"), cpu, true); |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1233 | error = _cpu_up(cpu, 1, CPUHP_ONLINE); |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1234 | trace_suspend_resume(TPS("CPU_ON"), cpu, false); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1235 | if (!error) { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1236 | pr_info("CPU%d is up\n", cpu); |
Thierry Strudel | 0c3610e | 2016-06-14 17:46:44 -0700 | [diff] [blame] | 1237 | cpu_device = get_cpu_device(cpu); |
| 1238 | if (!cpu_device) |
| 1239 | pr_err("%s: failed to get cpu%d device\n", |
| 1240 | __func__, cpu); |
| 1241 | else |
| 1242 | kobject_uevent(&cpu_device->kobj, KOBJ_ONLINE); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1243 | continue; |
| 1244 | } |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1245 | pr_warn("Error taking CPU%d up: %d\n", cpu, error); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1246 | } |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1247 | |
| 1248 | arch_enable_nonboot_cpus_end(); |
| 1249 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1250 | cpumask_clear(frozen_cpus); |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 1251 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1252 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1253 | } |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1254 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 1255 | static int __init alloc_frozen_cpus(void) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1256 | { |
| 1257 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) |
| 1258 | return -ENOMEM; |
| 1259 | return 0; |
| 1260 | } |
| 1261 | core_initcall(alloc_frozen_cpus); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1262 | |
| 1263 | /* |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1264 | * When callbacks for CPU hotplug notifications are being executed, we must |
| 1265 | * ensure that the state of the system with respect to the tasks being frozen |
| 1266 | * or not, as reported by the notification, remains unchanged *throughout the |
| 1267 | * duration* of the execution of the callbacks. |
| 1268 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. |
| 1269 | * |
| 1270 | * This synchronization is implemented by mutually excluding regular CPU |
| 1271 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ |
| 1272 | * Hibernate notifications. |
| 1273 | */ |
| 1274 | static int |
| 1275 | cpu_hotplug_pm_callback(struct notifier_block *nb, |
| 1276 | unsigned long action, void *ptr) |
| 1277 | { |
| 1278 | switch (action) { |
| 1279 | |
| 1280 | case PM_SUSPEND_PREPARE: |
| 1281 | case PM_HIBERNATION_PREPARE: |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 1282 | cpu_hotplug_disable(); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1283 | break; |
| 1284 | |
| 1285 | case PM_POST_SUSPEND: |
| 1286 | case PM_POST_HIBERNATION: |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 1287 | cpu_hotplug_enable(); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1288 | break; |
| 1289 | |
| 1290 | default: |
| 1291 | return NOTIFY_DONE; |
| 1292 | } |
| 1293 | |
| 1294 | return NOTIFY_OK; |
| 1295 | } |
| 1296 | |
| 1297 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 1298 | static int __init cpu_hotplug_pm_sync_init(void) |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1299 | { |
Fenghua Yu | 6e32d47 | 2012-11-13 11:32:43 -0800 | [diff] [blame] | 1300 | /* |
| 1301 | * cpu_hotplug_pm_callback has higher priority than x86 |
| 1302 | * bsp_pm_callback which depends on cpu_hotplug_pm_callback |
| 1303 | * to disable cpu hotplug to avoid cpu hotplug race. |
| 1304 | */ |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1305 | pm_notifier(cpu_hotplug_pm_callback, 0); |
| 1306 | return 0; |
| 1307 | } |
| 1308 | core_initcall(cpu_hotplug_pm_sync_init); |
| 1309 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 1310 | #endif /* CONFIG_PM_SLEEP_SMP */ |
Max Krasnyansky | 68f4f1e | 2008-05-29 11:17:02 -0700 | [diff] [blame] | 1311 | |
| 1312 | #endif /* CONFIG_SMP */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1313 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1314 | /* Boot processor state steps */ |
| 1315 | static struct cpuhp_step cpuhp_bp_states[] = { |
| 1316 | [CPUHP_OFFLINE] = { |
| 1317 | .name = "offline", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1318 | .startup.single = NULL, |
| 1319 | .teardown.single = NULL, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1320 | }, |
| 1321 | #ifdef CONFIG_SMP |
| 1322 | [CPUHP_CREATE_THREADS]= { |
Thomas Gleixner | 677f664 | 2016-09-06 16:13:48 +0200 | [diff] [blame] | 1323 | .name = "threads:prepare", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1324 | .startup.single = smpboot_create_threads, |
| 1325 | .teardown.single = NULL, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1326 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1327 | }, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1328 | [CPUHP_PERF_PREPARE] = { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1329 | .name = "perf:prepare", |
| 1330 | .startup.single = perf_event_init_cpu, |
| 1331 | .teardown.single = perf_event_exit_cpu, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1332 | }, |
Thomas Gleixner | 7ee681b | 2016-07-13 17:16:29 +0000 | [diff] [blame] | 1333 | [CPUHP_WORKQUEUE_PREP] = { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1334 | .name = "workqueue:prepare", |
| 1335 | .startup.single = workqueue_prepare_cpu, |
| 1336 | .teardown.single = NULL, |
Thomas Gleixner | 7ee681b | 2016-07-13 17:16:29 +0000 | [diff] [blame] | 1337 | }, |
Thomas Gleixner | 27590dc | 2016-07-15 10:41:04 +0200 | [diff] [blame] | 1338 | [CPUHP_HRTIMERS_PREPARE] = { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1339 | .name = "hrtimers:prepare", |
| 1340 | .startup.single = hrtimers_prepare_cpu, |
| 1341 | .teardown.single = hrtimers_dead_cpu, |
Thomas Gleixner | 27590dc | 2016-07-15 10:41:04 +0200 | [diff] [blame] | 1342 | }, |
Richard Weinberger | 31487f8 | 2016-07-13 17:17:01 +0000 | [diff] [blame] | 1343 | [CPUHP_SMPCFD_PREPARE] = { |
Thomas Gleixner | 677f664 | 2016-09-06 16:13:48 +0200 | [diff] [blame] | 1344 | .name = "smpcfd:prepare", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1345 | .startup.single = smpcfd_prepare_cpu, |
| 1346 | .teardown.single = smpcfd_dead_cpu, |
Richard Weinberger | 31487f8 | 2016-07-13 17:17:01 +0000 | [diff] [blame] | 1347 | }, |
Richard Weinberger | e6d4989 | 2016-08-18 14:57:17 +0200 | [diff] [blame] | 1348 | [CPUHP_RELAY_PREPARE] = { |
| 1349 | .name = "relay:prepare", |
| 1350 | .startup.single = relay_prepare_cpu, |
| 1351 | .teardown.single = NULL, |
| 1352 | }, |
Sebastian Andrzej Siewior | 6731d4f | 2016-08-23 14:53:19 +0200 | [diff] [blame] | 1353 | [CPUHP_SLAB_PREPARE] = { |
| 1354 | .name = "slab:prepare", |
| 1355 | .startup.single = slab_prepare_cpu, |
| 1356 | .teardown.single = slab_dead_cpu, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1357 | }, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1358 | [CPUHP_RCUTREE_PREP] = { |
Thomas Gleixner | 677f664 | 2016-09-06 16:13:48 +0200 | [diff] [blame] | 1359 | .name = "RCU/tree:prepare", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1360 | .startup.single = rcutree_prepare_cpu, |
| 1361 | .teardown.single = rcutree_dead_cpu, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1362 | }, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1363 | /* |
| 1364 | * Preparatory and dead notifiers. Will be replaced once the notifiers |
| 1365 | * are converted to states. |
| 1366 | */ |
| 1367 | [CPUHP_NOTIFY_PREPARE] = { |
| 1368 | .name = "notify:prepare", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1369 | .startup.single = notify_prepare, |
| 1370 | .teardown.single = notify_dead, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1371 | .skip_onerr = true, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1372 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1373 | }, |
Richard Cochran | 4fae16d | 2016-07-27 11:08:18 +0200 | [diff] [blame] | 1374 | /* |
| 1375 | * On the tear-down path, timers_dead_cpu() must be invoked |
| 1376 | * before blk_mq_queue_reinit_notify() from notify_dead(), |
| 1377 | * otherwise a RCU stall occurs. |
| 1378 | */ |
| 1379 | [CPUHP_TIMERS_DEAD] = { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1380 | .name = "timers:dead", |
| 1381 | .startup.single = NULL, |
| 1382 | .teardown.single = timers_dead_cpu, |
Richard Cochran | 4fae16d | 2016-07-27 11:08:18 +0200 | [diff] [blame] | 1383 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1384 | /* Kicks the plugged cpu into life */ |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1385 | [CPUHP_BRINGUP_CPU] = { |
| 1386 | .name = "cpu:bringup", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1387 | .startup.single = bringup_cpu, |
| 1388 | .teardown.single = NULL, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1389 | .cant_stop = true, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1390 | }, |
Richard Weinberger | 31487f8 | 2016-07-13 17:17:01 +0000 | [diff] [blame] | 1391 | [CPUHP_AP_SMPCFD_DYING] = { |
Thomas Gleixner | 677f664 | 2016-09-06 16:13:48 +0200 | [diff] [blame] | 1392 | .name = "smpcfd:dying", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1393 | .startup.single = NULL, |
| 1394 | .teardown.single = smpcfd_dying_cpu, |
Richard Weinberger | 31487f8 | 2016-07-13 17:17:01 +0000 | [diff] [blame] | 1395 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1396 | /* |
| 1397 | * Handled on controll processor until the plugged processor manages |
| 1398 | * this itself. |
| 1399 | */ |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1400 | [CPUHP_TEARDOWN_CPU] = { |
| 1401 | .name = "cpu:teardown", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1402 | .startup.single = NULL, |
| 1403 | .teardown.single = takedown_cpu, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1404 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1405 | }, |
Thomas Gleixner | a7c73414 | 2016-07-12 21:59:23 +0200 | [diff] [blame] | 1406 | #else |
| 1407 | [CPUHP_BRINGUP_CPU] = { }, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1408 | #endif |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1409 | }; |
| 1410 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1411 | /* Application processor state steps */ |
| 1412 | static struct cpuhp_step cpuhp_ap_states[] = { |
| 1413 | #ifdef CONFIG_SMP |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1414 | /* Final state before CPU kills itself */ |
| 1415 | [CPUHP_AP_IDLE_DEAD] = { |
| 1416 | .name = "idle:dead", |
| 1417 | }, |
| 1418 | /* |
| 1419 | * Last state before CPU enters the idle loop to die. Transient state |
| 1420 | * for synchronization. |
| 1421 | */ |
| 1422 | [CPUHP_AP_OFFLINE] = { |
| 1423 | .name = "ap:offline", |
| 1424 | .cant_stop = true, |
| 1425 | }, |
Thomas Gleixner | 9cf7243 | 2016-03-10 12:54:09 +0100 | [diff] [blame] | 1426 | /* First state is scheduler control. Interrupts are disabled */ |
| 1427 | [CPUHP_AP_SCHED_STARTING] = { |
| 1428 | .name = "sched:starting", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1429 | .startup.single = sched_cpu_starting, |
| 1430 | .teardown.single = sched_cpu_dying, |
Thomas Gleixner | 9cf7243 | 2016-03-10 12:54:09 +0100 | [diff] [blame] | 1431 | }, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1432 | [CPUHP_AP_RCUTREE_DYING] = { |
Thomas Gleixner | 677f664 | 2016-09-06 16:13:48 +0200 | [diff] [blame] | 1433 | .name = "RCU/tree:dying", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1434 | .startup.single = NULL, |
| 1435 | .teardown.single = rcutree_dying_cpu, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1436 | }, |
Maria Yu | e90f8e1 | 2017-09-21 11:30:53 +0800 | [diff] [blame] | 1437 | [CPUHP_AP_KMAP_DYING] = { |
| 1438 | .name = "KMAP:dying", |
| 1439 | .startup.single = NULL, |
| 1440 | .teardown.single = kmap_remove_unused_cpu, |
| 1441 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1442 | /* Entry state on starting. Interrupts enabled from here on. Transient |
| 1443 | * state for synchronsization */ |
| 1444 | [CPUHP_AP_ONLINE] = { |
| 1445 | .name = "ap:online", |
| 1446 | }, |
| 1447 | /* Handle smpboot threads park/unpark */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1448 | [CPUHP_AP_SMPBOOT_THREADS] = { |
Thomas Gleixner | 677f664 | 2016-09-06 16:13:48 +0200 | [diff] [blame] | 1449 | .name = "smpboot/threads:online", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1450 | .startup.single = smpboot_unpark_threads, |
| 1451 | .teardown.single = NULL, |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1452 | }, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1453 | [CPUHP_AP_PERF_ONLINE] = { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1454 | .name = "perf:online", |
| 1455 | .startup.single = perf_event_init_cpu, |
| 1456 | .teardown.single = perf_event_exit_cpu, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1457 | }, |
Thomas Gleixner | 7ee681b | 2016-07-13 17:16:29 +0000 | [diff] [blame] | 1458 | [CPUHP_AP_WORKQUEUE_ONLINE] = { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1459 | .name = "workqueue:online", |
| 1460 | .startup.single = workqueue_online_cpu, |
| 1461 | .teardown.single = workqueue_offline_cpu, |
Thomas Gleixner | 7ee681b | 2016-07-13 17:16:29 +0000 | [diff] [blame] | 1462 | }, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1463 | [CPUHP_AP_RCUTREE_ONLINE] = { |
Thomas Gleixner | 677f664 | 2016-09-06 16:13:48 +0200 | [diff] [blame] | 1464 | .name = "RCU/tree:online", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1465 | .startup.single = rcutree_online_cpu, |
| 1466 | .teardown.single = rcutree_offline_cpu, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1467 | }, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1468 | |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1469 | /* |
| 1470 | * Online/down_prepare notifiers. Will be removed once the notifiers |
| 1471 | * are converted to states. |
| 1472 | */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1473 | [CPUHP_AP_NOTIFY_ONLINE] = { |
| 1474 | .name = "notify:online", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1475 | .startup.single = notify_online, |
| 1476 | .teardown.single = notify_down_prepare, |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 1477 | .skip_onerr = true, |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1478 | }, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1479 | #endif |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1480 | /* |
| 1481 | * The dynamically registered state space is here |
| 1482 | */ |
| 1483 | |
Thomas Gleixner | aaddd7d | 2016-03-10 12:54:19 +0100 | [diff] [blame] | 1484 | #ifdef CONFIG_SMP |
| 1485 | /* Last state is scheduler control setting the cpu active */ |
| 1486 | [CPUHP_AP_ACTIVE] = { |
| 1487 | .name = "sched:active", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1488 | .startup.single = sched_cpu_activate, |
| 1489 | .teardown.single = sched_cpu_deactivate, |
Thomas Gleixner | aaddd7d | 2016-03-10 12:54:19 +0100 | [diff] [blame] | 1490 | }, |
| 1491 | #endif |
| 1492 | |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1493 | /* CPU is fully up and running. */ |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1494 | [CPUHP_ONLINE] = { |
| 1495 | .name = "online", |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1496 | .startup.single = NULL, |
| 1497 | .teardown.single = NULL, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1498 | }, |
| 1499 | }; |
| 1500 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1501 | /* Sanity check for callbacks */ |
| 1502 | static int cpuhp_cb_check(enum cpuhp_state state) |
| 1503 | { |
| 1504 | if (state <= CPUHP_OFFLINE || state >= CPUHP_ONLINE) |
| 1505 | return -EINVAL; |
| 1506 | return 0; |
| 1507 | } |
| 1508 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1509 | static void cpuhp_store_callbacks(enum cpuhp_state state, |
| 1510 | const char *name, |
| 1511 | int (*startup)(unsigned int cpu), |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1512 | int (*teardown)(unsigned int cpu), |
| 1513 | bool multi_instance) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1514 | { |
| 1515 | /* (Un)Install the callbacks for further cpu hotplug operations */ |
| 1516 | struct cpuhp_step *sp; |
| 1517 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1518 | sp = cpuhp_get_step(state); |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1519 | sp->startup.single = startup; |
| 1520 | sp->teardown.single = teardown; |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1521 | sp->name = name; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1522 | sp->multi_instance = multi_instance; |
| 1523 | INIT_HLIST_HEAD(&sp->list); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1524 | } |
| 1525 | |
| 1526 | static void *cpuhp_get_teardown_cb(enum cpuhp_state state) |
| 1527 | { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1528 | return cpuhp_get_step(state)->teardown.single; |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1529 | } |
| 1530 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1531 | /* |
| 1532 | * Call the startup/teardown function for a step either on the AP or |
| 1533 | * on the current CPU. |
| 1534 | */ |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1535 | static int cpuhp_issue_call(int cpu, enum cpuhp_state state, bool bringup, |
| 1536 | struct hlist_node *node) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1537 | { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 1538 | struct cpuhp_step *sp = cpuhp_get_step(state); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1539 | int ret; |
| 1540 | |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1541 | if ((bringup && !sp->startup.single) || |
| 1542 | (!bringup && !sp->teardown.single)) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1543 | return 0; |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1544 | /* |
| 1545 | * The non AP bound callbacks can fail on bringup. On teardown |
| 1546 | * e.g. module removal we crash for now. |
| 1547 | */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1548 | #ifdef CONFIG_SMP |
| 1549 | if (cpuhp_is_ap_state(state)) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1550 | ret = cpuhp_invoke_ap_callback(cpu, state, bringup, node); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1551 | else |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1552 | ret = cpuhp_invoke_callback(cpu, state, bringup, node); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1553 | #else |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1554 | ret = cpuhp_invoke_callback(cpu, state, bringup, node); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1555 | #endif |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1556 | BUG_ON(ret && !bringup); |
| 1557 | return ret; |
| 1558 | } |
| 1559 | |
| 1560 | /* |
| 1561 | * Called from __cpuhp_setup_state on a recoverable failure. |
| 1562 | * |
| 1563 | * Note: The teardown callbacks for rollback are not allowed to fail! |
| 1564 | */ |
| 1565 | static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state, |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1566 | struct hlist_node *node) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1567 | { |
| 1568 | int cpu; |
| 1569 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1570 | /* Roll back the already executed steps on the other cpus */ |
| 1571 | for_each_present_cpu(cpu) { |
| 1572 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1573 | int cpustate = st->state; |
| 1574 | |
| 1575 | if (cpu >= failedcpu) |
| 1576 | break; |
| 1577 | |
| 1578 | /* Did we invoke the startup call on that cpu ? */ |
| 1579 | if (cpustate >= state) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1580 | cpuhp_issue_call(cpu, state, false, node); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1581 | } |
| 1582 | } |
| 1583 | |
| 1584 | /* |
| 1585 | * Returns a free for dynamic slot assignment of the Online state. The states |
| 1586 | * are protected by the cpuhp_slot_states mutex and an empty slot is identified |
| 1587 | * by having no name assigned. |
| 1588 | */ |
| 1589 | static int cpuhp_reserve_state(enum cpuhp_state state) |
| 1590 | { |
| 1591 | enum cpuhp_state i; |
| 1592 | |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1593 | for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) { |
| 1594 | if (cpuhp_ap_states[i].name) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1595 | continue; |
| 1596 | |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1597 | cpuhp_ap_states[i].name = "Reserved"; |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1598 | return i; |
| 1599 | } |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1600 | WARN(1, "No more dynamic states available for CPU hotplug\n"); |
| 1601 | return -ENOSPC; |
| 1602 | } |
| 1603 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1604 | int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node, |
| 1605 | bool invoke) |
| 1606 | { |
| 1607 | struct cpuhp_step *sp; |
| 1608 | int cpu; |
| 1609 | int ret; |
| 1610 | |
| 1611 | sp = cpuhp_get_step(state); |
| 1612 | if (sp->multi_instance == false) |
| 1613 | return -EINVAL; |
| 1614 | |
| 1615 | get_online_cpus(); |
Sebastian Andrzej Siewior | 7ad6de4 | 2017-03-14 16:06:45 +0100 | [diff] [blame] | 1616 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1617 | |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1618 | if (!invoke || !sp->startup.multi) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1619 | goto add_node; |
| 1620 | |
| 1621 | /* |
| 1622 | * Try to call the startup callback for each present cpu |
| 1623 | * depending on the hotplug state of the cpu. |
| 1624 | */ |
| 1625 | for_each_present_cpu(cpu) { |
| 1626 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1627 | int cpustate = st->state; |
| 1628 | |
| 1629 | if (cpustate < state) |
| 1630 | continue; |
| 1631 | |
| 1632 | ret = cpuhp_issue_call(cpu, state, true, node); |
| 1633 | if (ret) { |
Thomas Gleixner | 3c1627e | 2016-09-05 15:28:36 +0200 | [diff] [blame] | 1634 | if (sp->teardown.multi) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1635 | cpuhp_rollback_install(cpu, state, node); |
| 1636 | goto err; |
| 1637 | } |
| 1638 | } |
| 1639 | add_node: |
| 1640 | ret = 0; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1641 | hlist_add_head(node, &sp->list); |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1642 | |
| 1643 | err: |
Sebastian Andrzej Siewior | 7ad6de4 | 2017-03-14 16:06:45 +0100 | [diff] [blame] | 1644 | mutex_unlock(&cpuhp_state_mutex); |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1645 | put_online_cpus(); |
| 1646 | return ret; |
| 1647 | } |
| 1648 | EXPORT_SYMBOL_GPL(__cpuhp_state_add_instance); |
| 1649 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1650 | /** |
| 1651 | * __cpuhp_setup_state - Setup the callbacks for an hotplug machine state |
| 1652 | * @state: The state to setup |
| 1653 | * @invoke: If true, the startup function is invoked for cpus where |
| 1654 | * cpu state >= @state |
| 1655 | * @startup: startup callback function |
| 1656 | * @teardown: teardown callback function |
| 1657 | * |
| 1658 | * Returns 0 if successful, otherwise a proper error code |
| 1659 | */ |
| 1660 | int __cpuhp_setup_state(enum cpuhp_state state, |
| 1661 | const char *name, bool invoke, |
| 1662 | int (*startup)(unsigned int cpu), |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1663 | int (*teardown)(unsigned int cpu), |
| 1664 | bool multi_instance) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1665 | { |
| 1666 | int cpu, ret = 0; |
| 1667 | int dyn_state = 0; |
| 1668 | |
| 1669 | if (cpuhp_cb_check(state) || !name) |
| 1670 | return -EINVAL; |
| 1671 | |
| 1672 | get_online_cpus(); |
Sebastian Andrzej Siewior | 7ad6de4 | 2017-03-14 16:06:45 +0100 | [diff] [blame] | 1673 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1674 | |
| 1675 | /* currently assignments for the ONLINE state are possible */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1676 | if (state == CPUHP_AP_ONLINE_DYN) { |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1677 | dyn_state = 1; |
| 1678 | ret = cpuhp_reserve_state(state); |
| 1679 | if (ret < 0) |
| 1680 | goto out; |
| 1681 | state = ret; |
| 1682 | } |
| 1683 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1684 | cpuhp_store_callbacks(state, name, startup, teardown, multi_instance); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1685 | |
| 1686 | if (!invoke || !startup) |
| 1687 | goto out; |
| 1688 | |
| 1689 | /* |
| 1690 | * Try to call the startup callback for each present cpu |
| 1691 | * depending on the hotplug state of the cpu. |
| 1692 | */ |
| 1693 | for_each_present_cpu(cpu) { |
| 1694 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1695 | int cpustate = st->state; |
| 1696 | |
| 1697 | if (cpustate < state) |
| 1698 | continue; |
| 1699 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1700 | ret = cpuhp_issue_call(cpu, state, true, NULL); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1701 | if (ret) { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 1702 | if (teardown) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1703 | cpuhp_rollback_install(cpu, state, NULL); |
| 1704 | cpuhp_store_callbacks(state, NULL, NULL, NULL, false); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1705 | goto out; |
| 1706 | } |
| 1707 | } |
| 1708 | out: |
Sebastian Andrzej Siewior | 7ad6de4 | 2017-03-14 16:06:45 +0100 | [diff] [blame] | 1709 | mutex_unlock(&cpuhp_state_mutex); |
| 1710 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1711 | put_online_cpus(); |
| 1712 | if (!ret && dyn_state) |
| 1713 | return state; |
| 1714 | return ret; |
| 1715 | } |
| 1716 | EXPORT_SYMBOL(__cpuhp_setup_state); |
| 1717 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1718 | int __cpuhp_state_remove_instance(enum cpuhp_state state, |
| 1719 | struct hlist_node *node, bool invoke) |
| 1720 | { |
| 1721 | struct cpuhp_step *sp = cpuhp_get_step(state); |
| 1722 | int cpu; |
| 1723 | |
| 1724 | BUG_ON(cpuhp_cb_check(state)); |
| 1725 | |
| 1726 | if (!sp->multi_instance) |
| 1727 | return -EINVAL; |
| 1728 | |
| 1729 | get_online_cpus(); |
Sebastian Andrzej Siewior | 7ad6de4 | 2017-03-14 16:06:45 +0100 | [diff] [blame] | 1730 | mutex_lock(&cpuhp_state_mutex); |
| 1731 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1732 | if (!invoke || !cpuhp_get_teardown_cb(state)) |
| 1733 | goto remove; |
| 1734 | /* |
| 1735 | * Call the teardown callback for each present cpu depending |
| 1736 | * on the hotplug state of the cpu. This function is not |
| 1737 | * allowed to fail currently! |
| 1738 | */ |
| 1739 | for_each_present_cpu(cpu) { |
| 1740 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1741 | int cpustate = st->state; |
| 1742 | |
| 1743 | if (cpustate >= state) |
| 1744 | cpuhp_issue_call(cpu, state, false, node); |
| 1745 | } |
| 1746 | |
| 1747 | remove: |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1748 | hlist_del(node); |
| 1749 | mutex_unlock(&cpuhp_state_mutex); |
| 1750 | put_online_cpus(); |
| 1751 | |
| 1752 | return 0; |
| 1753 | } |
| 1754 | EXPORT_SYMBOL_GPL(__cpuhp_state_remove_instance); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1755 | /** |
| 1756 | * __cpuhp_remove_state - Remove the callbacks for an hotplug machine state |
| 1757 | * @state: The state to remove |
| 1758 | * @invoke: If true, the teardown function is invoked for cpus where |
| 1759 | * cpu state >= @state |
| 1760 | * |
| 1761 | * The teardown callback is currently not allowed to fail. Think |
| 1762 | * about module removal! |
| 1763 | */ |
| 1764 | void __cpuhp_remove_state(enum cpuhp_state state, bool invoke) |
| 1765 | { |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1766 | struct cpuhp_step *sp = cpuhp_get_step(state); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1767 | int cpu; |
| 1768 | |
| 1769 | BUG_ON(cpuhp_cb_check(state)); |
| 1770 | |
| 1771 | get_online_cpus(); |
Sebastian Andrzej Siewior | 7ad6de4 | 2017-03-14 16:06:45 +0100 | [diff] [blame] | 1772 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1773 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1774 | if (sp->multi_instance) { |
| 1775 | WARN(!hlist_empty(&sp->list), |
| 1776 | "Error: Removing state %d which has instances left.\n", |
| 1777 | state); |
| 1778 | goto remove; |
| 1779 | } |
| 1780 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 1781 | if (!invoke || !cpuhp_get_teardown_cb(state)) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1782 | goto remove; |
| 1783 | |
| 1784 | /* |
| 1785 | * Call the teardown callback for each present cpu depending |
| 1786 | * on the hotplug state of the cpu. This function is not |
| 1787 | * allowed to fail currently! |
| 1788 | */ |
| 1789 | for_each_present_cpu(cpu) { |
| 1790 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1791 | int cpustate = st->state; |
| 1792 | |
| 1793 | if (cpustate >= state) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1794 | cpuhp_issue_call(cpu, state, false, NULL); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1795 | } |
| 1796 | remove: |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame] | 1797 | cpuhp_store_callbacks(state, NULL, NULL, NULL, false); |
Sebastian Andrzej Siewior | 7ad6de4 | 2017-03-14 16:06:45 +0100 | [diff] [blame] | 1798 | mutex_unlock(&cpuhp_state_mutex); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1799 | put_online_cpus(); |
| 1800 | } |
| 1801 | EXPORT_SYMBOL(__cpuhp_remove_state); |
| 1802 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1803 | #if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU) |
| 1804 | static ssize_t show_cpuhp_state(struct device *dev, |
| 1805 | struct device_attribute *attr, char *buf) |
| 1806 | { |
| 1807 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1808 | |
| 1809 | return sprintf(buf, "%d\n", st->state); |
| 1810 | } |
| 1811 | static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL); |
| 1812 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1813 | static ssize_t write_cpuhp_target(struct device *dev, |
| 1814 | struct device_attribute *attr, |
| 1815 | const char *buf, size_t count) |
| 1816 | { |
| 1817 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1818 | struct cpuhp_step *sp; |
| 1819 | int target, ret; |
| 1820 | |
| 1821 | ret = kstrtoint(buf, 10, &target); |
| 1822 | if (ret) |
| 1823 | return ret; |
| 1824 | |
| 1825 | #ifdef CONFIG_CPU_HOTPLUG_STATE_CONTROL |
| 1826 | if (target < CPUHP_OFFLINE || target > CPUHP_ONLINE) |
| 1827 | return -EINVAL; |
| 1828 | #else |
| 1829 | if (target != CPUHP_OFFLINE && target != CPUHP_ONLINE) |
| 1830 | return -EINVAL; |
| 1831 | #endif |
| 1832 | |
| 1833 | ret = lock_device_hotplug_sysfs(); |
| 1834 | if (ret) |
| 1835 | return ret; |
| 1836 | |
| 1837 | mutex_lock(&cpuhp_state_mutex); |
| 1838 | sp = cpuhp_get_step(target); |
| 1839 | ret = !sp->name || sp->cant_stop ? -EINVAL : 0; |
| 1840 | mutex_unlock(&cpuhp_state_mutex); |
| 1841 | if (ret) |
Sebastian Andrzej Siewior | 106c77e | 2017-06-02 16:27:14 +0200 | [diff] [blame] | 1842 | goto out; |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1843 | |
| 1844 | if (st->state < target) |
| 1845 | ret = do_cpu_up(dev->id, target); |
| 1846 | else |
| 1847 | ret = do_cpu_down(dev->id, target); |
Sebastian Andrzej Siewior | 106c77e | 2017-06-02 16:27:14 +0200 | [diff] [blame] | 1848 | out: |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1849 | unlock_device_hotplug(); |
| 1850 | return ret ? ret : count; |
| 1851 | } |
| 1852 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1853 | static ssize_t show_cpuhp_target(struct device *dev, |
| 1854 | struct device_attribute *attr, char *buf) |
| 1855 | { |
| 1856 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1857 | |
| 1858 | return sprintf(buf, "%d\n", st->target); |
| 1859 | } |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1860 | static DEVICE_ATTR(target, 0644, show_cpuhp_target, write_cpuhp_target); |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1861 | |
| 1862 | static struct attribute *cpuhp_cpu_attrs[] = { |
| 1863 | &dev_attr_state.attr, |
| 1864 | &dev_attr_target.attr, |
| 1865 | NULL |
| 1866 | }; |
| 1867 | |
| 1868 | static struct attribute_group cpuhp_cpu_attr_group = { |
| 1869 | .attrs = cpuhp_cpu_attrs, |
| 1870 | .name = "hotplug", |
| 1871 | NULL |
| 1872 | }; |
| 1873 | |
| 1874 | static ssize_t show_cpuhp_states(struct device *dev, |
| 1875 | struct device_attribute *attr, char *buf) |
| 1876 | { |
| 1877 | ssize_t cur, res = 0; |
| 1878 | int i; |
| 1879 | |
| 1880 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1881 | for (i = CPUHP_OFFLINE; i <= CPUHP_ONLINE; i++) { |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1882 | struct cpuhp_step *sp = cpuhp_get_step(i); |
| 1883 | |
| 1884 | if (sp->name) { |
| 1885 | cur = sprintf(buf, "%3d: %s\n", i, sp->name); |
| 1886 | buf += cur; |
| 1887 | res += cur; |
| 1888 | } |
| 1889 | } |
| 1890 | mutex_unlock(&cpuhp_state_mutex); |
| 1891 | return res; |
| 1892 | } |
| 1893 | static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL); |
| 1894 | |
| 1895 | static struct attribute *cpuhp_cpu_root_attrs[] = { |
| 1896 | &dev_attr_states.attr, |
| 1897 | NULL |
| 1898 | }; |
| 1899 | |
| 1900 | static struct attribute_group cpuhp_cpu_root_attr_group = { |
| 1901 | .attrs = cpuhp_cpu_root_attrs, |
| 1902 | .name = "hotplug", |
| 1903 | NULL |
| 1904 | }; |
| 1905 | |
| 1906 | static int __init cpuhp_sysfs_init(void) |
| 1907 | { |
| 1908 | int cpu, ret; |
| 1909 | |
| 1910 | ret = sysfs_create_group(&cpu_subsys.dev_root->kobj, |
| 1911 | &cpuhp_cpu_root_attr_group); |
| 1912 | if (ret) |
| 1913 | return ret; |
| 1914 | |
| 1915 | for_each_possible_cpu(cpu) { |
| 1916 | struct device *dev = get_cpu_device(cpu); |
| 1917 | |
| 1918 | if (!dev) |
| 1919 | continue; |
| 1920 | ret = sysfs_create_group(&dev->kobj, &cpuhp_cpu_attr_group); |
| 1921 | if (ret) |
| 1922 | return ret; |
| 1923 | } |
| 1924 | return 0; |
| 1925 | } |
| 1926 | device_initcall(cpuhp_sysfs_init); |
| 1927 | #endif |
| 1928 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1929 | /* |
| 1930 | * cpu_bit_bitmap[] is a special, "compressed" data structure that |
| 1931 | * represents all NR_CPUS bits binary values of 1<<nr. |
| 1932 | * |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1933 | * 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] | 1934 | * mask value that has a single bit set only. |
| 1935 | */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1936 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1937 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 1938 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1939 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) |
| 1940 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) |
| 1941 | #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] | 1942 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1943 | 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] | 1944 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1945 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), |
| 1946 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), |
| 1947 | #if BITS_PER_LONG > 32 |
| 1948 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), |
| 1949 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1950 | #endif |
| 1951 | }; |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1952 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1953 | |
| 1954 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; |
| 1955 | EXPORT_SYMBOL(cpu_all_bits); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1956 | |
| 1957 | #ifdef CONFIG_INIT_ALL_POSSIBLE |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1958 | struct cpumask __cpu_possible_mask __read_mostly |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1959 | = {CPU_BITS_ALL}; |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1960 | #else |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1961 | struct cpumask __cpu_possible_mask __read_mostly; |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1962 | #endif |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1963 | EXPORT_SYMBOL(__cpu_possible_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1964 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1965 | struct cpumask __cpu_online_mask __read_mostly; |
| 1966 | EXPORT_SYMBOL(__cpu_online_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1967 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1968 | struct cpumask __cpu_present_mask __read_mostly; |
| 1969 | EXPORT_SYMBOL(__cpu_present_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1970 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1971 | struct cpumask __cpu_active_mask __read_mostly; |
| 1972 | EXPORT_SYMBOL(__cpu_active_mask); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1973 | |
Olav Haugan | 99cd46a | 2016-05-29 19:56:37 -0700 | [diff] [blame] | 1974 | struct cpumask __cpu_isolated_mask __read_mostly; |
| 1975 | EXPORT_SYMBOL(__cpu_isolated_mask); |
| 1976 | |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1977 | void init_cpu_present(const struct cpumask *src) |
| 1978 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1979 | cpumask_copy(&__cpu_present_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1980 | } |
| 1981 | |
| 1982 | void init_cpu_possible(const struct cpumask *src) |
| 1983 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1984 | cpumask_copy(&__cpu_possible_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1985 | } |
| 1986 | |
| 1987 | void init_cpu_online(const struct cpumask *src) |
| 1988 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1989 | cpumask_copy(&__cpu_online_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1990 | } |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1991 | |
Olav Haugan | 99cd46a | 2016-05-29 19:56:37 -0700 | [diff] [blame] | 1992 | void init_cpu_isolated(const struct cpumask *src) |
| 1993 | { |
| 1994 | cpumask_copy(&__cpu_isolated_mask, src); |
| 1995 | } |
| 1996 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1997 | /* |
| 1998 | * Activate the first processor. |
| 1999 | */ |
| 2000 | void __init boot_cpu_init(void) |
| 2001 | { |
| 2002 | int cpu = smp_processor_id(); |
| 2003 | |
| 2004 | /* Mark the boot cpu "present", "online" etc for SMP and UP case */ |
| 2005 | set_cpu_online(cpu, true); |
| 2006 | set_cpu_active(cpu, true); |
| 2007 | set_cpu_present(cpu, true); |
| 2008 | set_cpu_possible(cpu, true); |
| 2009 | } |
| 2010 | |
| 2011 | /* |
| 2012 | * Must be called _AFTER_ setting up the per_cpu areas |
| 2013 | */ |
| 2014 | void __init boot_cpu_state_init(void) |
| 2015 | { |
| 2016 | per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE; |
| 2017 | } |
Todd Poynor | ef07e9e4 | 2011-06-15 17:21:57 -0700 | [diff] [blame] | 2018 | |
| 2019 | static ATOMIC_NOTIFIER_HEAD(idle_notifier); |
| 2020 | |
| 2021 | void idle_notifier_register(struct notifier_block *n) |
| 2022 | { |
| 2023 | atomic_notifier_chain_register(&idle_notifier, n); |
| 2024 | } |
| 2025 | EXPORT_SYMBOL_GPL(idle_notifier_register); |
| 2026 | |
| 2027 | void idle_notifier_unregister(struct notifier_block *n) |
| 2028 | { |
| 2029 | atomic_notifier_chain_unregister(&idle_notifier, n); |
| 2030 | } |
| 2031 | EXPORT_SYMBOL_GPL(idle_notifier_unregister); |
| 2032 | |
| 2033 | void idle_notifier_call_chain(unsigned long val) |
| 2034 | { |
| 2035 | atomic_notifier_call_chain(&idle_notifier, val, NULL); |
| 2036 | } |
| 2037 | EXPORT_SYMBOL_GPL(idle_notifier_call_chain); |