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> |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 26 | |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 27 | #include <trace/events/power.h> |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 28 | #define CREATE_TRACE_POINTS |
| 29 | #include <trace/events/cpuhp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 31 | #include "smpboot.h" |
| 32 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 33 | /** |
| 34 | * cpuhp_cpu_state - Per cpu hotplug state storage |
| 35 | * @state: The current cpu state |
| 36 | * @target: The target state |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 37 | * @thread: Pointer to the hotplug thread |
| 38 | * @should_run: Thread should execute |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 39 | * @rollback: Perform a rollback |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 40 | * @single: Single callback invocation |
| 41 | * @bringup: Single callback bringup or teardown selector |
| 42 | * @cb_state: The state for a single callback (install/uninstall) |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 43 | * @result: Result of the operation |
| 44 | * @done: Signal completion to the issuer of the task |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 45 | */ |
| 46 | struct cpuhp_cpu_state { |
| 47 | enum cpuhp_state state; |
| 48 | enum cpuhp_state target; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 49 | #ifdef CONFIG_SMP |
| 50 | struct task_struct *thread; |
| 51 | bool should_run; |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 52 | bool rollback; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 53 | bool single; |
| 54 | bool bringup; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 55 | struct hlist_node *node; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 56 | enum cpuhp_state cb_state; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 57 | int result; |
| 58 | struct completion done; |
| 59 | #endif |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 60 | }; |
| 61 | |
| 62 | static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state); |
| 63 | |
| 64 | /** |
| 65 | * cpuhp_step - Hotplug state machine step |
| 66 | * @name: Name of the step |
| 67 | * @startup: Startup function of the step |
| 68 | * @teardown: Teardown function of the step |
| 69 | * @skip_onerr: Do not invoke the functions on error rollback |
| 70 | * Will go away once the notifiers are gone |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 71 | * @cant_stop: Bringup/teardown can't be stopped at this step |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 72 | */ |
| 73 | struct cpuhp_step { |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 74 | const char *name; |
| 75 | union { |
| 76 | int (*startup)(unsigned int cpu); |
| 77 | int (*startup_multi)(unsigned int cpu, |
| 78 | struct hlist_node *node); |
| 79 | }; |
| 80 | union { |
| 81 | int (*teardown)(unsigned int cpu); |
| 82 | int (*teardown_multi)(unsigned int cpu, |
| 83 | struct hlist_node *node); |
| 84 | }; |
| 85 | struct hlist_head list; |
| 86 | bool skip_onerr; |
| 87 | bool cant_stop; |
| 88 | bool multi_instance; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 89 | }; |
| 90 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 91 | static DEFINE_MUTEX(cpuhp_state_mutex); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 92 | static struct cpuhp_step cpuhp_bp_states[]; |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 93 | static struct cpuhp_step cpuhp_ap_states[]; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 94 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 95 | static bool cpuhp_is_ap_state(enum cpuhp_state state) |
| 96 | { |
| 97 | /* |
| 98 | * The extra check for CPUHP_TEARDOWN_CPU is only for documentation |
| 99 | * purposes as that state is handled explicitly in cpu_down. |
| 100 | */ |
| 101 | return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU; |
| 102 | } |
| 103 | |
| 104 | static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state) |
| 105 | { |
| 106 | struct cpuhp_step *sp; |
| 107 | |
| 108 | sp = cpuhp_is_ap_state(state) ? cpuhp_ap_states : cpuhp_bp_states; |
| 109 | return sp + state; |
| 110 | } |
| 111 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 112 | /** |
| 113 | * cpuhp_invoke_callback _ Invoke the callbacks for a given state |
| 114 | * @cpu: The cpu for which the callback should be invoked |
| 115 | * @step: The step in the state machine |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 116 | * @bringup: True if the bringup callback should be invoked |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 117 | * |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 118 | * Called from cpu hotplug and from the state register machinery. |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 119 | */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 120 | static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state, |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 121 | bool bringup, struct hlist_node *node) |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 122 | { |
| 123 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 124 | struct cpuhp_step *step = cpuhp_get_step(state); |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 125 | int (*cbm)(unsigned int cpu, struct hlist_node *node); |
| 126 | int (*cb)(unsigned int cpu); |
| 127 | int ret, cnt; |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 128 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 129 | if (!step->multi_instance) { |
| 130 | cb = bringup ? step->startup : step->teardown; |
| 131 | if (!cb) |
| 132 | return 0; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 133 | trace_cpuhp_enter(cpu, st->target, state, cb); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 134 | ret = cb(cpu); |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 135 | trace_cpuhp_exit(cpu, st->state, state, ret); |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 136 | return ret; |
| 137 | } |
| 138 | cbm = bringup ? step->startup_multi : step->teardown_multi; |
| 139 | if (!cbm) |
| 140 | return 0; |
| 141 | |
| 142 | /* Single invocation for instance add/remove */ |
| 143 | if (node) { |
| 144 | trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node); |
| 145 | ret = cbm(cpu, node); |
| 146 | trace_cpuhp_exit(cpu, st->state, state, ret); |
| 147 | return ret; |
| 148 | } |
| 149 | |
| 150 | /* State transition. Invoke on all instances */ |
| 151 | cnt = 0; |
| 152 | hlist_for_each(node, &step->list) { |
| 153 | trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node); |
| 154 | ret = cbm(cpu, node); |
| 155 | trace_cpuhp_exit(cpu, st->state, state, ret); |
| 156 | if (ret) |
| 157 | goto err; |
| 158 | cnt++; |
| 159 | } |
| 160 | return 0; |
| 161 | err: |
| 162 | /* Rollback the instances if one failed */ |
| 163 | cbm = !bringup ? step->startup_multi : step->teardown_multi; |
| 164 | if (!cbm) |
| 165 | return ret; |
| 166 | |
| 167 | hlist_for_each(node, &step->list) { |
| 168 | if (!cnt--) |
| 169 | break; |
| 170 | cbm(cpu, node); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 171 | } |
| 172 | return ret; |
| 173 | } |
| 174 | |
Rusty Russell | 98a79d6 | 2008-12-13 21:19:41 +1030 | [diff] [blame] | 175 | #ifdef CONFIG_SMP |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 176 | /* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 177 | static DEFINE_MUTEX(cpu_add_remove_lock); |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 178 | bool cpuhp_tasks_frozen; |
| 179 | EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 181 | /* |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 182 | * The following two APIs (cpu_maps_update_begin/done) must be used when |
| 183 | * attempting to serialize the updates to cpu_online_mask & cpu_present_mask. |
| 184 | * The APIs cpu_notifier_register_begin/done() must be used to protect CPU |
| 185 | * hotplug callback (un)registration performed using __register_cpu_notifier() |
| 186 | * or __unregister_cpu_notifier(). |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 187 | */ |
| 188 | void cpu_maps_update_begin(void) |
| 189 | { |
| 190 | mutex_lock(&cpu_add_remove_lock); |
| 191 | } |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 192 | EXPORT_SYMBOL(cpu_notifier_register_begin); |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 193 | |
| 194 | void cpu_maps_update_done(void) |
| 195 | { |
| 196 | mutex_unlock(&cpu_add_remove_lock); |
| 197 | } |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 198 | EXPORT_SYMBOL(cpu_notifier_register_done); |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 199 | |
Daniel J Blueman | 5c113fb | 2010-06-01 12:15:11 +0100 | [diff] [blame] | 200 | static RAW_NOTIFIER_HEAD(cpu_chain); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 202 | /* If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
| 203 | * Should always be manipulated under cpu_add_remove_lock |
| 204 | */ |
| 205 | static int cpu_hotplug_disabled; |
| 206 | |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 207 | #ifdef CONFIG_HOTPLUG_CPU |
| 208 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 209 | static struct { |
| 210 | struct task_struct *active_writer; |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 211 | /* wait queue to wake up the active_writer */ |
| 212 | wait_queue_head_t wq; |
| 213 | /* verifies that no writer will get active while readers are active */ |
| 214 | struct mutex lock; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 215 | /* |
| 216 | * Also blocks the new readers during |
| 217 | * an ongoing cpu hotplug operation. |
| 218 | */ |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 219 | atomic_t refcount; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 220 | |
| 221 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| 222 | struct lockdep_map dep_map; |
| 223 | #endif |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 224 | } cpu_hotplug = { |
| 225 | .active_writer = NULL, |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 226 | .wq = __WAIT_QUEUE_HEAD_INITIALIZER(cpu_hotplug.wq), |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 227 | .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 228 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| 229 | .dep_map = {.name = "cpu_hotplug.lock" }, |
| 230 | #endif |
Linus Torvalds | 31950eb | 2009-06-22 21:18:12 -0700 | [diff] [blame] | 231 | }; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 232 | |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 233 | /* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */ |
| 234 | #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] | 235 | #define cpuhp_lock_acquire_tryread() \ |
| 236 | lock_map_acquire_tryread(&cpu_hotplug.dep_map) |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 237 | #define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map) |
| 238 | #define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map) |
| 239 | |
Paul E. McKenney | 62db99f | 2014-10-22 14:51:49 -0700 | [diff] [blame] | 240 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 241 | void get_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 242 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 243 | might_sleep(); |
| 244 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 245 | return; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 246 | cpuhp_lock_acquire_read(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 247 | mutex_lock(&cpu_hotplug.lock); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 248 | atomic_inc(&cpu_hotplug.refcount); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 249 | mutex_unlock(&cpu_hotplug.lock); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 250 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 251 | EXPORT_SYMBOL_GPL(get_online_cpus); |
Ashok Raj | 90d45d1 | 2005-11-08 21:34:24 -0800 | [diff] [blame] | 252 | |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 253 | void put_online_cpus(void) |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 254 | { |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 255 | int refcount; |
| 256 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 257 | if (cpu_hotplug.active_writer == current) |
Linus Torvalds | aa95387 | 2006-07-23 12:12:16 -0700 | [diff] [blame] | 258 | return; |
Srivatsa S. Bhat | 075663d | 2012-10-08 16:28:20 -0700 | [diff] [blame] | 259 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 260 | refcount = atomic_dec_return(&cpu_hotplug.refcount); |
| 261 | if (WARN_ON(refcount < 0)) /* try to fix things up */ |
| 262 | atomic_inc(&cpu_hotplug.refcount); |
Srivatsa S. Bhat | 075663d | 2012-10-08 16:28:20 -0700 | [diff] [blame] | 263 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 264 | if (refcount <= 0 && waitqueue_active(&cpu_hotplug.wq)) |
| 265 | wake_up(&cpu_hotplug.wq); |
| 266 | |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 267 | cpuhp_lock_release(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 268 | |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 269 | } |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 270 | EXPORT_SYMBOL_GPL(put_online_cpus); |
Ashok Raj | a9d9baa | 2005-11-28 13:43:46 -0800 | [diff] [blame] | 271 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 272 | /* |
| 273 | * This ensures that the hotplug operation can begin only when the |
| 274 | * refcount goes to zero. |
| 275 | * |
| 276 | * Note that during a cpu-hotplug operation, the new readers, if any, |
| 277 | * will be blocked by the cpu_hotplug.lock |
| 278 | * |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 279 | * Since cpu_hotplug_begin() is always called after invoking |
| 280 | * 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] | 281 | * |
| 282 | * Note that theoretically, there is a possibility of a livelock: |
| 283 | * - Refcount goes to zero, last reader wakes up the sleeping |
| 284 | * writer. |
| 285 | * - Last reader unlocks the cpu_hotplug.lock. |
| 286 | * - A new reader arrives at this moment, bumps up the refcount. |
| 287 | * - The writer acquires the cpu_hotplug.lock finds the refcount |
| 288 | * non zero and goes to sleep again. |
| 289 | * |
| 290 | * However, this is very difficult to achieve in practice since |
Gautham R Shenoy | 86ef5c9 | 2008-01-25 21:08:02 +0100 | [diff] [blame] | 291 | * 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] | 292 | * |
| 293 | */ |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 294 | void cpu_hotplug_begin(void) |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 295 | { |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 296 | DEFINE_WAIT(wait); |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 297 | |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 298 | cpu_hotplug.active_writer = current; |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 299 | cpuhp_lock_acquire(); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 300 | |
Oleg Nesterov | d2ba7e2 | 2008-04-29 01:00:29 -0700 | [diff] [blame] | 301 | for (;;) { |
| 302 | mutex_lock(&cpu_hotplug.lock); |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 303 | prepare_to_wait(&cpu_hotplug.wq, &wait, TASK_UNINTERRUPTIBLE); |
| 304 | if (likely(!atomic_read(&cpu_hotplug.refcount))) |
| 305 | break; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 306 | mutex_unlock(&cpu_hotplug.lock); |
| 307 | schedule(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 308 | } |
David Hildenbrand | 87af9e7 | 2014-12-12 10:11:44 +0100 | [diff] [blame] | 309 | finish_wait(&cpu_hotplug.wq, &wait); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 310 | } |
| 311 | |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 312 | void cpu_hotplug_done(void) |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 313 | { |
| 314 | cpu_hotplug.active_writer = NULL; |
| 315 | mutex_unlock(&cpu_hotplug.lock); |
Gautham R. Shenoy | a19423b | 2014-03-11 02:04:03 +0530 | [diff] [blame] | 316 | cpuhp_lock_release(); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 317 | } |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 318 | |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 319 | /* |
| 320 | * Wait for currently running CPU hotplug operations to complete (if any) and |
| 321 | * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects |
| 322 | * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the |
| 323 | * hotplug path before performing hotplug operations. So acquiring that lock |
| 324 | * guarantees mutual exclusion from any currently running hotplug operations. |
| 325 | */ |
| 326 | void cpu_hotplug_disable(void) |
| 327 | { |
| 328 | cpu_maps_update_begin(); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 329 | cpu_hotplug_disabled++; |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 330 | cpu_maps_update_done(); |
| 331 | } |
Vitaly Kuznetsov | 32145c4 | 2015-08-05 00:52:47 -0700 | [diff] [blame] | 332 | EXPORT_SYMBOL_GPL(cpu_hotplug_disable); |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 333 | |
| 334 | void cpu_hotplug_enable(void) |
| 335 | { |
| 336 | cpu_maps_update_begin(); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 337 | WARN_ON(--cpu_hotplug_disabled < 0); |
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_enable); |
Toshi Kani | b9d10be | 2013-08-12 09:45:53 -0600 | [diff] [blame] | 341 | #endif /* CONFIG_HOTPLUG_CPU */ |
Lai Jiangshan | 79a6cde | 2010-05-26 14:43:36 -0700 | [diff] [blame] | 342 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | /* Need to know about CPUs going up/down? */ |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 344 | int register_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | { |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 346 | int ret; |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 347 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 348 | ret = raw_notifier_chain_register(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 349 | cpu_maps_update_done(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 350 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | } |
Chandra Seetharaman | 65edc68 | 2006-06-27 02:54:08 -0700 | [diff] [blame] | 352 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 353 | int __register_cpu_notifier(struct notifier_block *nb) |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 354 | { |
| 355 | return raw_notifier_chain_register(&cpu_chain, nb); |
| 356 | } |
| 357 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 358 | 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] | 359 | int *nr_calls) |
| 360 | { |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 361 | unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0; |
| 362 | void *hcpu = (void *)(long)cpu; |
| 363 | |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 364 | int ret; |
| 365 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 366 | 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] | 367 | nr_calls); |
Akinobu Mita | e6bde73 | 2010-05-26 14:43:29 -0700 | [diff] [blame] | 368 | |
| 369 | return notifier_to_errno(ret); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 370 | } |
| 371 | |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 372 | static int cpu_notify(unsigned long val, unsigned int cpu) |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 373 | { |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 374 | return __cpu_notify(val, cpu, -1, NULL); |
Akinobu Mita | e9fb763 | 2010-05-26 14:43:28 -0700 | [diff] [blame] | 375 | } |
| 376 | |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 377 | static void cpu_notify_nofail(unsigned long val, unsigned int cpu) |
| 378 | { |
| 379 | BUG_ON(cpu_notify(val, cpu)); |
| 380 | } |
| 381 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 382 | /* Notifier wrappers for transitioning to state machine */ |
| 383 | static int notify_prepare(unsigned int cpu) |
| 384 | { |
| 385 | int nr_calls = 0; |
| 386 | int ret; |
| 387 | |
| 388 | ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls); |
| 389 | if (ret) { |
| 390 | nr_calls--; |
| 391 | printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", |
| 392 | __func__, cpu); |
| 393 | __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL); |
| 394 | } |
| 395 | return ret; |
| 396 | } |
| 397 | |
| 398 | static int notify_online(unsigned int cpu) |
| 399 | { |
| 400 | cpu_notify(CPU_ONLINE, cpu); |
| 401 | return 0; |
| 402 | } |
| 403 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 404 | static int notify_starting(unsigned int cpu) |
| 405 | { |
| 406 | cpu_notify(CPU_STARTING, cpu); |
| 407 | return 0; |
| 408 | } |
| 409 | |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 410 | static int bringup_wait_for_ap(unsigned int cpu) |
| 411 | { |
| 412 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 413 | |
| 414 | wait_for_completion(&st->done); |
| 415 | return st->result; |
| 416 | } |
| 417 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 418 | static int bringup_cpu(unsigned int cpu) |
| 419 | { |
| 420 | struct task_struct *idle = idle_thread_get(cpu); |
| 421 | int ret; |
| 422 | |
Boris Ostrovsky | aa87717 | 2016-08-03 13:22:28 -0400 | [diff] [blame] | 423 | /* |
| 424 | * Some architectures have to walk the irq descriptors to |
| 425 | * setup the vector space for the cpu which comes online. |
| 426 | * Prevent irq alloc/free across the bringup. |
| 427 | */ |
| 428 | irq_lock_sparse(); |
| 429 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 430 | /* Arch-specific enabling code. */ |
| 431 | ret = __cpu_up(cpu, idle); |
Boris Ostrovsky | aa87717 | 2016-08-03 13:22:28 -0400 | [diff] [blame] | 432 | irq_unlock_sparse(); |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 433 | if (ret) { |
| 434 | cpu_notify(CPU_UP_CANCELED, cpu); |
| 435 | return ret; |
| 436 | } |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 437 | ret = bringup_wait_for_ap(cpu); |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 438 | BUG_ON(!cpu_online(cpu)); |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 439 | return ret; |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 440 | } |
| 441 | |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 442 | /* |
| 443 | * Hotplug state machine related functions |
| 444 | */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 445 | 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] | 446 | { |
| 447 | for (st->state++; st->state < st->target; st->state++) { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 448 | struct cpuhp_step *step = cpuhp_get_step(st->state); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 449 | |
| 450 | if (!step->skip_onerr) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 451 | cpuhp_invoke_callback(cpu, st->state, true, NULL); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 452 | } |
| 453 | } |
| 454 | |
| 455 | 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] | 456 | enum cpuhp_state target) |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 457 | { |
| 458 | enum cpuhp_state prev_state = st->state; |
| 459 | int ret = 0; |
| 460 | |
| 461 | for (; st->state > target; st->state--) { |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 462 | ret = cpuhp_invoke_callback(cpu, st->state, false, NULL); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 463 | if (ret) { |
| 464 | st->target = prev_state; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 465 | undo_cpu_down(cpu, st); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 466 | break; |
| 467 | } |
| 468 | } |
| 469 | return ret; |
| 470 | } |
| 471 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 472 | 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] | 473 | { |
| 474 | for (st->state--; st->state > st->target; st->state--) { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 475 | struct cpuhp_step *step = cpuhp_get_step(st->state); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 476 | |
| 477 | if (!step->skip_onerr) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 478 | cpuhp_invoke_callback(cpu, st->state, false, NULL); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 479 | } |
| 480 | } |
| 481 | |
| 482 | 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] | 483 | enum cpuhp_state target) |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 484 | { |
| 485 | enum cpuhp_state prev_state = st->state; |
| 486 | int ret = 0; |
| 487 | |
| 488 | while (st->state < target) { |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 489 | st->state++; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 490 | ret = cpuhp_invoke_callback(cpu, st->state, true, NULL); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 491 | if (ret) { |
| 492 | st->target = prev_state; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 493 | undo_cpu_up(cpu, st); |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 494 | break; |
| 495 | } |
| 496 | } |
| 497 | return ret; |
| 498 | } |
| 499 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 500 | /* |
| 501 | * The cpu hotplug threads manage the bringup and teardown of the cpus |
| 502 | */ |
| 503 | static void cpuhp_create(unsigned int cpu) |
| 504 | { |
| 505 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 506 | |
| 507 | init_completion(&st->done); |
| 508 | } |
| 509 | |
| 510 | static int cpuhp_should_run(unsigned int cpu) |
| 511 | { |
| 512 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 513 | |
| 514 | return st->should_run; |
| 515 | } |
| 516 | |
| 517 | /* Execute the teardown callbacks. Used to be CPU_DOWN_PREPARE */ |
| 518 | static int cpuhp_ap_offline(unsigned int cpu, struct cpuhp_cpu_state *st) |
| 519 | { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 520 | enum cpuhp_state target = max((int)st->target, CPUHP_TEARDOWN_CPU); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 521 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 522 | return cpuhp_down_callbacks(cpu, st, target); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 523 | } |
| 524 | |
| 525 | /* Execute the online startup callbacks. Used to be CPU_ONLINE */ |
| 526 | static int cpuhp_ap_online(unsigned int cpu, struct cpuhp_cpu_state *st) |
| 527 | { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 528 | return cpuhp_up_callbacks(cpu, st, st->target); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 529 | } |
| 530 | |
| 531 | /* |
| 532 | * Execute teardown/startup callbacks on the plugged cpu. Also used to invoke |
| 533 | * callbacks when a state gets [un]installed at runtime. |
| 534 | */ |
| 535 | static void cpuhp_thread_fun(unsigned int cpu) |
| 536 | { |
| 537 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 538 | int ret = 0; |
| 539 | |
| 540 | /* |
| 541 | * Paired with the mb() in cpuhp_kick_ap_work and |
| 542 | * cpuhp_invoke_ap_callback, so the work set is consistent visible. |
| 543 | */ |
| 544 | smp_mb(); |
| 545 | if (!st->should_run) |
| 546 | return; |
| 547 | |
| 548 | st->should_run = false; |
| 549 | |
| 550 | /* Single callback invocation for [un]install ? */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 551 | if (st->single) { |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 552 | if (st->cb_state < CPUHP_AP_ONLINE) { |
| 553 | local_irq_disable(); |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 554 | ret = cpuhp_invoke_callback(cpu, st->cb_state, |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 555 | st->bringup, st->node); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 556 | local_irq_enable(); |
| 557 | } else { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 558 | ret = cpuhp_invoke_callback(cpu, st->cb_state, |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 559 | st->bringup, st->node); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 560 | } |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 561 | } else if (st->rollback) { |
| 562 | BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE); |
| 563 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 564 | undo_cpu_down(cpu, st); |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 565 | /* |
| 566 | * This is a momentary workaround to keep the notifier users |
| 567 | * happy. Will go away once we got rid of the notifiers. |
| 568 | */ |
| 569 | cpu_notify_nofail(CPU_DOWN_FAILED, cpu); |
| 570 | st->rollback = false; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 571 | } else { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 572 | /* Cannot happen .... */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 573 | BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 574 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 575 | /* Regular hotplug work */ |
| 576 | if (st->state < st->target) |
| 577 | ret = cpuhp_ap_online(cpu, st); |
| 578 | else if (st->state > st->target) |
| 579 | ret = cpuhp_ap_offline(cpu, st); |
| 580 | } |
| 581 | st->result = ret; |
| 582 | complete(&st->done); |
| 583 | } |
| 584 | |
| 585 | /* Invoke a single callback on a remote cpu */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 586 | static int |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 587 | cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state, bool bringup, |
| 588 | struct hlist_node *node) |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 589 | { |
| 590 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 591 | |
| 592 | if (!cpu_online(cpu)) |
| 593 | return 0; |
| 594 | |
Thomas Gleixner | 6a4e245 | 2016-07-13 17:16:03 +0000 | [diff] [blame] | 595 | /* |
| 596 | * If we are up and running, use the hotplug thread. For early calls |
| 597 | * we invoke the thread function directly. |
| 598 | */ |
| 599 | if (!st->thread) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 600 | return cpuhp_invoke_callback(cpu, state, bringup, node); |
Thomas Gleixner | 6a4e245 | 2016-07-13 17:16:03 +0000 | [diff] [blame] | 601 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 602 | st->cb_state = state; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 603 | st->single = true; |
| 604 | st->bringup = bringup; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 605 | st->node = node; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 606 | |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 607 | /* |
| 608 | * Make sure the above stores are visible before should_run becomes |
| 609 | * true. Paired with the mb() above in cpuhp_thread_fun() |
| 610 | */ |
| 611 | smp_mb(); |
| 612 | st->should_run = true; |
| 613 | wake_up_process(st->thread); |
| 614 | wait_for_completion(&st->done); |
| 615 | return st->result; |
| 616 | } |
| 617 | |
| 618 | /* Regular hotplug invocation of the AP hotplug thread */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 619 | static void __cpuhp_kick_ap_work(struct cpuhp_cpu_state *st) |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 620 | { |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 621 | st->result = 0; |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 622 | st->single = false; |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 623 | /* |
| 624 | * Make sure the above stores are visible before should_run becomes |
| 625 | * true. Paired with the mb() above in cpuhp_thread_fun() |
| 626 | */ |
| 627 | smp_mb(); |
| 628 | st->should_run = true; |
| 629 | wake_up_process(st->thread); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 630 | } |
| 631 | |
| 632 | static int cpuhp_kick_ap_work(unsigned int cpu) |
| 633 | { |
| 634 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 635 | enum cpuhp_state state = st->state; |
| 636 | |
| 637 | trace_cpuhp_enter(cpu, st->target, state, cpuhp_kick_ap_work); |
| 638 | __cpuhp_kick_ap_work(st); |
Thomas Gleixner | 4cb28ce | 2016-02-26 18:43:38 +0000 | [diff] [blame] | 639 | wait_for_completion(&st->done); |
| 640 | trace_cpuhp_exit(cpu, st->state, state, st->result); |
| 641 | return st->result; |
| 642 | } |
| 643 | |
| 644 | static struct smp_hotplug_thread cpuhp_threads = { |
| 645 | .store = &cpuhp_state.thread, |
| 646 | .create = &cpuhp_create, |
| 647 | .thread_should_run = cpuhp_should_run, |
| 648 | .thread_fn = cpuhp_thread_fun, |
| 649 | .thread_comm = "cpuhp/%u", |
| 650 | .selfparking = true, |
| 651 | }; |
| 652 | |
| 653 | void __init cpuhp_threads_init(void) |
| 654 | { |
| 655 | BUG_ON(smpboot_register_percpu_thread(&cpuhp_threads)); |
| 656 | kthread_unpark(this_cpu_read(cpuhp_state.thread)); |
| 657 | } |
| 658 | |
Linus Torvalds | 00b9b0a | 2010-05-27 10:32:08 -0700 | [diff] [blame] | 659 | #ifdef CONFIG_HOTPLUG_CPU |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | EXPORT_SYMBOL(register_cpu_notifier); |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 661 | EXPORT_SYMBOL(__register_cpu_notifier); |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 662 | void unregister_cpu_notifier(struct notifier_block *nb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | { |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 664 | cpu_maps_update_begin(); |
Neil Brown | bd5349c | 2006-10-17 00:10:35 -0700 | [diff] [blame] | 665 | raw_notifier_chain_unregister(&cpu_chain, nb); |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 666 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 667 | } |
| 668 | EXPORT_SYMBOL(unregister_cpu_notifier); |
| 669 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 670 | void __unregister_cpu_notifier(struct notifier_block *nb) |
Srivatsa S. Bhat | 93ae4f9 | 2014-03-11 02:04:14 +0530 | [diff] [blame] | 671 | { |
| 672 | raw_notifier_chain_unregister(&cpu_chain, nb); |
| 673 | } |
| 674 | EXPORT_SYMBOL(__unregister_cpu_notifier); |
| 675 | |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 676 | /** |
| 677 | * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU |
| 678 | * @cpu: a CPU id |
| 679 | * |
| 680 | * This function walks all processes, finds a valid mm struct for each one and |
| 681 | * then clears a corresponding bit in mm's cpumask. While this all sounds |
| 682 | * trivial, there are various non-obvious corner cases, which this function |
| 683 | * tries to solve in a safe manner. |
| 684 | * |
| 685 | * Also note that the function uses a somewhat relaxed locking scheme, so it may |
| 686 | * be called only for an already offlined CPU. |
| 687 | */ |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 688 | void clear_tasks_mm_cpumask(int cpu) |
| 689 | { |
| 690 | struct task_struct *p; |
| 691 | |
| 692 | /* |
| 693 | * This function is called after the cpu is taken down and marked |
| 694 | * offline, so its not like new tasks will ever get this cpu set in |
| 695 | * their mm mask. -- Peter Zijlstra |
| 696 | * Thus, we may use rcu_read_lock() here, instead of grabbing |
| 697 | * full-fledged tasklist_lock. |
| 698 | */ |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 699 | WARN_ON(cpu_online(cpu)); |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 700 | rcu_read_lock(); |
| 701 | for_each_process(p) { |
| 702 | struct task_struct *t; |
| 703 | |
Anton Vorontsov | e4cc2f8 | 2012-05-31 16:26:26 -0700 | [diff] [blame] | 704 | /* |
| 705 | * Main thread might exit, but other threads may still have |
| 706 | * a valid mm. Find one. |
| 707 | */ |
Anton Vorontsov | cb79295 | 2012-05-31 16:26:22 -0700 | [diff] [blame] | 708 | t = find_lock_task_mm(p); |
| 709 | if (!t) |
| 710 | continue; |
| 711 | cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); |
| 712 | task_unlock(t); |
| 713 | } |
| 714 | rcu_read_unlock(); |
| 715 | } |
| 716 | |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 717 | static inline void check_for_tasks(int dead_cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 718 | { |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 719 | struct task_struct *g, *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | |
Oleg Nesterov | a75a606 | 2015-09-10 15:07:50 +0200 | [diff] [blame] | 721 | read_lock(&tasklist_lock); |
| 722 | for_each_process_thread(g, p) { |
Kirill Tkhai | b728ca0 | 2014-06-25 12:19:55 +0400 | [diff] [blame] | 723 | if (!p->on_rq) |
| 724 | continue; |
| 725 | /* |
| 726 | * We do the check with unlocked task_rq(p)->lock. |
| 727 | * Order the reading to do not warn about a task, |
| 728 | * which was running on this cpu in the past, and |
| 729 | * it's just been woken on another cpu. |
| 730 | */ |
| 731 | rmb(); |
| 732 | if (task_cpu(p) != dead_cpu) |
| 733 | continue; |
| 734 | |
| 735 | pr_warn("Task %s (pid=%d) is on cpu %d (state=%ld, flags=%x)\n", |
| 736 | p->comm, task_pid_nr(p), dead_cpu, p->state, p->flags); |
Oleg Nesterov | a75a606 | 2015-09-10 15:07:50 +0200 | [diff] [blame] | 737 | } |
| 738 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | } |
| 740 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 741 | static int notify_down_prepare(unsigned int cpu) |
| 742 | { |
| 743 | int err, nr_calls = 0; |
| 744 | |
| 745 | err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls); |
| 746 | if (err) { |
| 747 | nr_calls--; |
| 748 | __cpu_notify(CPU_DOWN_FAILED, cpu, nr_calls, NULL); |
| 749 | pr_warn("%s: attempt to take down CPU %u failed\n", |
| 750 | __func__, cpu); |
| 751 | } |
| 752 | return err; |
| 753 | } |
| 754 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 755 | static int notify_dying(unsigned int cpu) |
| 756 | { |
| 757 | cpu_notify(CPU_DYING, cpu); |
| 758 | return 0; |
| 759 | } |
| 760 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 761 | /* Take this CPU down. */ |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 762 | static int take_cpu_down(void *_param) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 763 | { |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 764 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 765 | enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE); |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 766 | int err, cpu = smp_processor_id(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 767 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | /* Ensure this CPU doesn't handle any more interrupts. */ |
| 769 | err = __cpu_disable(); |
| 770 | if (err < 0) |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 771 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 772 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 773 | /* |
| 774 | * We get here while we are in CPUHP_TEARDOWN_CPU state and we must not |
| 775 | * do this step again. |
| 776 | */ |
| 777 | WARN_ON(st->state != CPUHP_TEARDOWN_CPU); |
| 778 | st->state--; |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 779 | /* Invoke the former CPU_DYING callbacks */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 780 | for (; st->state > target; st->state--) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 781 | cpuhp_invoke_callback(cpu, st->state, false, NULL); |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 782 | |
Thomas Gleixner | 52c063d | 2015-04-03 02:37:24 +0200 | [diff] [blame] | 783 | /* Give up timekeeping duties */ |
| 784 | tick_handover_do_timer(); |
Thomas Gleixner | 14e568e | 2013-01-31 12:11:14 +0000 | [diff] [blame] | 785 | /* Park the stopper thread */ |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 786 | stop_machine_park(cpu); |
Zwane Mwaikambo | f370513 | 2005-06-25 14:54:50 -0700 | [diff] [blame] | 787 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 788 | } |
| 789 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 790 | static int takedown_cpu(unsigned int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 791 | { |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 792 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 793 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 794 | |
Thomas Gleixner | 2a58c52 | 2016-03-10 20:42:08 +0100 | [diff] [blame] | 795 | /* Park the smpboot threads */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 796 | kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread); |
Thomas Gleixner | 2a58c52 | 2016-03-10 20:42:08 +0100 | [diff] [blame] | 797 | smpboot_park_threads(cpu); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 798 | |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 799 | /* |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 800 | * Prevent irq alloc/free while the dying cpu reorganizes the |
| 801 | * interrupt affinities. |
| 802 | */ |
| 803 | irq_lock_sparse(); |
| 804 | |
| 805 | /* |
Peter Zijlstra | 6acce3e | 2013-10-11 14:38:20 +0200 | [diff] [blame] | 806 | * So now all preempt/rcu users must observe !cpu_active(). |
| 807 | */ |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 808 | err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu)); |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 809 | if (err) { |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 810 | /* CPU refused to die */ |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 811 | irq_unlock_sparse(); |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 812 | /* Unpark the hotplug thread so we can rollback there */ |
| 813 | kthread_unpark(per_cpu_ptr(&cpuhp_state, cpu)->thread); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 814 | return err; |
Satoru Takeuchi | 8fa1d7d | 2006-10-28 10:38:57 -0700 | [diff] [blame] | 815 | } |
Rusty Russell | 0432158 | 2008-07-28 12:16:29 -0500 | [diff] [blame] | 816 | BUG_ON(cpu_online(cpu)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 817 | |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 818 | /* |
| 819 | * The migration_call() CPU_DYING callback will have removed all |
| 820 | * runnable tasks from the cpu, there's only the idle task left now |
| 821 | * that the migration thread is done doing the stop_machine thing. |
Peter Zijlstra | 51a96c7 | 2010-11-19 20:37:53 +0100 | [diff] [blame] | 822 | * |
| 823 | * Wait for the stop thread to go away. |
Peter Zijlstra | 48c5cca | 2010-11-13 19:32:29 +0100 | [diff] [blame] | 824 | */ |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 825 | wait_for_completion(&st->done); |
| 826 | BUG_ON(st->state != CPUHP_AP_IDLE_DEAD); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | |
Thomas Gleixner | a899418 | 2015-07-05 17:12:30 +0000 | [diff] [blame] | 828 | /* Interrupts are moved away from the dying cpu, reenable alloc/free */ |
| 829 | irq_unlock_sparse(); |
| 830 | |
Preeti U Murthy | 345527b | 2015-03-30 14:59:19 +0530 | [diff] [blame] | 831 | hotplug_cpu__broadcast_tick_pull(cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 832 | /* This actually kills the CPU. */ |
| 833 | __cpu_die(cpu); |
| 834 | |
Thomas Gleixner | a49b116 | 2015-04-03 02:38:05 +0200 | [diff] [blame] | 835 | tick_cleanup_dead_cpu(cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 836 | return 0; |
| 837 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 838 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 839 | static int notify_dead(unsigned int cpu) |
| 840 | { |
| 841 | cpu_notify_nofail(CPU_DEAD, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 842 | check_for_tasks(cpu); |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 843 | return 0; |
| 844 | } |
| 845 | |
Thomas Gleixner | 71f87b2 | 2016-03-03 10:52:10 +0100 | [diff] [blame] | 846 | static void cpuhp_complete_idle_dead(void *arg) |
| 847 | { |
| 848 | struct cpuhp_cpu_state *st = arg; |
| 849 | |
| 850 | complete(&st->done); |
| 851 | } |
| 852 | |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 853 | void cpuhp_report_idle_dead(void) |
| 854 | { |
| 855 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 856 | |
| 857 | BUG_ON(st->state != CPUHP_AP_OFFLINE); |
Thomas Gleixner | 27d50c7 | 2016-02-26 18:43:44 +0000 | [diff] [blame] | 858 | rcu_report_dead(smp_processor_id()); |
Thomas Gleixner | 71f87b2 | 2016-03-03 10:52:10 +0100 | [diff] [blame] | 859 | st->state = CPUHP_AP_IDLE_DEAD; |
| 860 | /* |
| 861 | * We cannot call complete after rcu_report_dead() so we delegate it |
| 862 | * to an online cpu. |
| 863 | */ |
| 864 | smp_call_function_single(cpumask_first(cpu_online_mask), |
| 865 | cpuhp_complete_idle_dead, st, 0); |
Thomas Gleixner | e69aab1 | 2016-02-26 18:43:43 +0000 | [diff] [blame] | 866 | } |
| 867 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 868 | #else |
| 869 | #define notify_down_prepare NULL |
| 870 | #define takedown_cpu NULL |
| 871 | #define notify_dead NULL |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 872 | #define notify_dying NULL |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 873 | #endif |
| 874 | |
| 875 | #ifdef CONFIG_HOTPLUG_CPU |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 876 | |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 877 | /* Requires cpu_add_remove_lock to be held */ |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 878 | static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, |
| 879 | enum cpuhp_state target) |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 880 | { |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 881 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 882 | int prev_state, ret = 0; |
| 883 | bool hasdied = false; |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 884 | |
| 885 | if (num_online_cpus() == 1) |
| 886 | return -EBUSY; |
| 887 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 888 | if (!cpu_present(cpu)) |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 889 | return -EINVAL; |
| 890 | |
| 891 | cpu_hotplug_begin(); |
| 892 | |
| 893 | cpuhp_tasks_frozen = tasks_frozen; |
| 894 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 895 | prev_state = st->state; |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 896 | st->target = target; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 897 | /* |
| 898 | * If the current CPU state is in the range of the AP hotplug thread, |
| 899 | * then we need to kick the thread. |
| 900 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 901 | if (st->state > CPUHP_TEARDOWN_CPU) { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 902 | ret = cpuhp_kick_ap_work(cpu); |
| 903 | /* |
| 904 | * The AP side has done the error rollback already. Just |
| 905 | * return the error code.. |
| 906 | */ |
| 907 | if (ret) |
| 908 | goto out; |
| 909 | |
| 910 | /* |
| 911 | * We might have stopped still in the range of the AP hotplug |
| 912 | * thread. Nothing to do anymore. |
| 913 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 914 | if (st->state > CPUHP_TEARDOWN_CPU) |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 915 | goto out; |
| 916 | } |
| 917 | /* |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 918 | * The AP brought itself down to CPUHP_TEARDOWN_CPU. So we need |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 919 | * to do the further cleanups. |
| 920 | */ |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 921 | ret = cpuhp_down_callbacks(cpu, st, target); |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 922 | if (ret && st->state > CPUHP_TEARDOWN_CPU && st->state < prev_state) { |
| 923 | st->target = prev_state; |
| 924 | st->rollback = true; |
| 925 | cpuhp_kick_ap_work(cpu); |
| 926 | } |
Thomas Gleixner | 9845817 | 2016-02-26 18:43:25 +0000 | [diff] [blame] | 927 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 928 | hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 929 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 930 | cpu_hotplug_done(); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 931 | /* This post dead nonsense must die */ |
| 932 | if (!ret && hasdied) |
Thomas Gleixner | 090e77c | 2016-02-26 18:43:23 +0000 | [diff] [blame] | 933 | cpu_notify_nofail(CPU_POST_DEAD, cpu); |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 934 | return ret; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 935 | } |
| 936 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 937 | 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] | 938 | { |
Heiko Carstens | 9ea09af | 2008-12-22 12:36:30 +0100 | [diff] [blame] | 939 | int err; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 940 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 941 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 942 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 943 | if (cpu_hotplug_disabled) { |
| 944 | err = -EBUSY; |
| 945 | goto out; |
| 946 | } |
| 947 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 948 | err = _cpu_down(cpu, 0, target); |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 949 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 950 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 951 | cpu_maps_update_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 952 | return err; |
| 953 | } |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 954 | int cpu_down(unsigned int cpu) |
| 955 | { |
| 956 | return do_cpu_down(cpu, CPUHP_OFFLINE); |
| 957 | } |
Zhang Rui | b62b8ef | 2008-04-29 02:35:56 -0400 | [diff] [blame] | 958 | EXPORT_SYMBOL(cpu_down); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 959 | #endif /*CONFIG_HOTPLUG_CPU*/ |
| 960 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 961 | /** |
| 962 | * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers |
| 963 | * @cpu: cpu that just started |
| 964 | * |
| 965 | * This function calls the cpu_chain notifiers with CPU_STARTING. |
| 966 | * It must be called by the arch code on the new cpu, before the new cpu |
| 967 | * enables interrupts and before the "boot" cpu returns from __cpu_up(). |
| 968 | */ |
| 969 | void notify_cpu_starting(unsigned int cpu) |
| 970 | { |
| 971 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 972 | enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE); |
| 973 | |
| 974 | while (st->state < target) { |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 975 | st->state++; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 976 | cpuhp_invoke_callback(cpu, st->state, true, NULL); |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 977 | } |
| 978 | } |
| 979 | |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 980 | /* |
| 981 | * Called from the idle task. We need to set active here, so we can kick off |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 982 | * the stopper thread and unpark the smpboot threads. If the target state is |
| 983 | * beyond CPUHP_AP_ONLINE_IDLE we kick cpuhp thread and let it bring up the |
| 984 | * cpu further. |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 985 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 986 | void cpuhp_online_idle(enum cpuhp_state state) |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 987 | { |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 988 | struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
| 989 | unsigned int cpu = smp_processor_id(); |
| 990 | |
| 991 | /* Happens for the boot cpu */ |
| 992 | if (state != CPUHP_AP_ONLINE_IDLE) |
| 993 | return; |
| 994 | |
| 995 | st->state = CPUHP_AP_ONLINE_IDLE; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 996 | |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 997 | /* Unpark the stopper thread and the hotplug thread of this cpu */ |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 998 | stop_machine_unpark(cpu); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 999 | kthread_unpark(st->thread); |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 1000 | |
| 1001 | /* Should we go further up ? */ |
| 1002 | if (st->target > CPUHP_AP_ONLINE_IDLE) |
| 1003 | __cpuhp_kick_ap_work(st); |
| 1004 | else |
| 1005 | complete(&st->done); |
Thomas Gleixner | 949338e | 2016-02-26 18:43:35 +0000 | [diff] [blame] | 1006 | } |
| 1007 | |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1008 | /* Requires cpu_add_remove_lock to be held */ |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1009 | 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] | 1010 | { |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1011 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 1012 | struct task_struct *idle; |
Thomas Gleixner | 2e1a348 | 2016-02-26 18:43:37 +0000 | [diff] [blame] | 1013 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1014 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1015 | cpu_hotplug_begin(); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 1016 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1017 | if (!cpu_present(cpu)) { |
Yasuaki Ishimatsu | 5e5041f | 2012-10-23 01:30:54 +0200 | [diff] [blame] | 1018 | ret = -EINVAL; |
| 1019 | goto out; |
| 1020 | } |
| 1021 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1022 | /* |
| 1023 | * The caller of do_cpu_up might have raced with another |
| 1024 | * caller. Ignore it for now. |
| 1025 | */ |
| 1026 | if (st->state >= target) |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 1027 | goto out; |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1028 | |
| 1029 | if (st->state == CPUHP_OFFLINE) { |
| 1030 | /* Let it fail before we try to bring the cpu up */ |
| 1031 | idle = idle_thread_get(cpu); |
| 1032 | if (IS_ERR(idle)) { |
| 1033 | ret = PTR_ERR(idle); |
| 1034 | goto out; |
| 1035 | } |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 1036 | } |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 1037 | |
Thomas Gleixner | ba99746 | 2016-02-26 18:43:24 +0000 | [diff] [blame] | 1038 | cpuhp_tasks_frozen = tasks_frozen; |
| 1039 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1040 | st->target = target; |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1041 | /* |
| 1042 | * If the current CPU state is in the range of the AP hotplug thread, |
| 1043 | * then we need to kick the thread once more. |
| 1044 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 1045 | if (st->state > CPUHP_BRINGUP_CPU) { |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1046 | ret = cpuhp_kick_ap_work(cpu); |
| 1047 | /* |
| 1048 | * The AP side has done the error rollback already. Just |
| 1049 | * return the error code.. |
| 1050 | */ |
| 1051 | if (ret) |
| 1052 | goto out; |
| 1053 | } |
| 1054 | |
| 1055 | /* |
| 1056 | * 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] | 1057 | * CPUHP_BRINGUP_CPU. After that the AP hotplug thread is |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1058 | * responsible for bringing it up to the target state. |
| 1059 | */ |
Thomas Gleixner | 8df3e07 | 2016-02-26 18:43:41 +0000 | [diff] [blame] | 1060 | target = min((int)target, CPUHP_BRINGUP_CPU); |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 1061 | ret = cpuhp_up_callbacks(cpu, st, target); |
Thomas Gleixner | 38498a6 | 2012-04-20 13:05:44 +0000 | [diff] [blame] | 1062 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1063 | cpu_hotplug_done(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1064 | return ret; |
| 1065 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1066 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1067 | 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] | 1068 | { |
| 1069 | int err = 0; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 1070 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1071 | if (!cpu_possible(cpu)) { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1072 | pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n", |
| 1073 | cpu); |
Chen Gong | 87d5e02 | 2010-03-05 13:42:38 -0800 | [diff] [blame] | 1074 | #if defined(CONFIG_IA64) |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1075 | pr_err("please check additional_cpus= boot parameter\n"); |
KAMEZAWA Hiroyuki | 73e753a | 2007-10-18 23:40:47 -0700 | [diff] [blame] | 1076 | #endif |
| 1077 | return -EINVAL; |
| 1078 | } |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1079 | |
Toshi Kani | 01b0f19 | 2013-11-12 15:07:25 -0800 | [diff] [blame] | 1080 | err = try_online_node(cpu_to_node(cpu)); |
| 1081 | if (err) |
| 1082 | return err; |
minskey guo | cf23422 | 2010-05-24 14:32:41 -0700 | [diff] [blame] | 1083 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1084 | cpu_maps_update_begin(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1085 | |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 1086 | if (cpu_hotplug_disabled) { |
| 1087 | err = -EBUSY; |
| 1088 | goto out; |
| 1089 | } |
| 1090 | |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1091 | err = _cpu_up(cpu, 0, target); |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 1092 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1093 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1094 | return err; |
| 1095 | } |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1096 | |
| 1097 | int cpu_up(unsigned int cpu) |
| 1098 | { |
| 1099 | return do_cpu_up(cpu, CPUHP_ONLINE); |
| 1100 | } |
Paul E. McKenney | a513f6b | 2011-12-11 21:54:45 -0800 | [diff] [blame] | 1101 | EXPORT_SYMBOL_GPL(cpu_up); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1102 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 1103 | #ifdef CONFIG_PM_SLEEP_SMP |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1104 | static cpumask_var_t frozen_cpus; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1105 | |
| 1106 | int disable_nonboot_cpus(void) |
| 1107 | { |
Rafael J. Wysocki | e9a5f42 | 2010-05-27 22:16:22 +0200 | [diff] [blame] | 1108 | int cpu, first_cpu, error = 0; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1109 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1110 | cpu_maps_update_begin(); |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1111 | first_cpu = cpumask_first(cpu_online_mask); |
Xiaotian Feng | 9ee349a | 2009-12-16 18:04:32 +0100 | [diff] [blame] | 1112 | /* |
| 1113 | * 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] | 1114 | * with the userspace trying to use the CPU hotplug at the same time |
| 1115 | */ |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1116 | cpumask_clear(frozen_cpus); |
Peter Zijlstra | 6ad4c18 | 2009-11-25 13:31:39 +0100 | [diff] [blame] | 1117 | |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1118 | pr_info("Disabling non-boot CPUs ...\n"); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1119 | for_each_online_cpu(cpu) { |
| 1120 | if (cpu == first_cpu) |
| 1121 | continue; |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1122 | trace_suspend_resume(TPS("CPU_OFF"), cpu, true); |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1123 | error = _cpu_down(cpu, 1, CPUHP_OFFLINE); |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1124 | trace_suspend_resume(TPS("CPU_OFF"), cpu, false); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 1125 | if (!error) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1126 | cpumask_set_cpu(cpu, frozen_cpus); |
Mike Travis | feae320 | 2009-11-17 18:22:13 -0600 | [diff] [blame] | 1127 | else { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1128 | pr_err("Error taking CPU%d down: %d\n", cpu, error); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1129 | break; |
| 1130 | } |
| 1131 | } |
Joseph Cihula | 86886e5 | 2009-06-30 19:31:07 -0700 | [diff] [blame] | 1132 | |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1133 | if (!error) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1134 | BUG_ON(num_online_cpus() > 1); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1135 | else |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1136 | pr_err("Non-boot CPUs are not disabled\n"); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1137 | |
| 1138 | /* |
| 1139 | * Make sure the CPUs won't be enabled by someone else. We need to do |
| 1140 | * this even in case of failure as all disable_nonboot_cpus() users are |
| 1141 | * supposed to do enable_nonboot_cpus() on the failure path. |
| 1142 | */ |
| 1143 | cpu_hotplug_disabled++; |
| 1144 | |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1145 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1146 | return error; |
| 1147 | } |
| 1148 | |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1149 | void __weak arch_enable_nonboot_cpus_begin(void) |
| 1150 | { |
| 1151 | } |
| 1152 | |
| 1153 | void __weak arch_enable_nonboot_cpus_end(void) |
| 1154 | { |
| 1155 | } |
| 1156 | |
Mathias Krause | 71cf5ae | 2015-07-19 20:06:22 +0200 | [diff] [blame] | 1157 | void enable_nonboot_cpus(void) |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1158 | { |
| 1159 | int cpu, error; |
| 1160 | |
| 1161 | /* Allow everyone to use the CPU hotplug again */ |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1162 | cpu_maps_update_begin(); |
Vitaly Kuznetsov | 89af7ba | 2015-08-05 00:52:46 -0700 | [diff] [blame] | 1163 | WARN_ON(--cpu_hotplug_disabled < 0); |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1164 | if (cpumask_empty(frozen_cpus)) |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 1165 | goto out; |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1166 | |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1167 | pr_info("Enabling non-boot CPUs ...\n"); |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1168 | |
| 1169 | arch_enable_nonboot_cpus_begin(); |
| 1170 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1171 | for_each_cpu(cpu, frozen_cpus) { |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1172 | trace_suspend_resume(TPS("CPU_ON"), cpu, true); |
Thomas Gleixner | af1f404 | 2016-02-26 18:43:30 +0000 | [diff] [blame] | 1173 | error = _cpu_up(cpu, 1, CPUHP_ONLINE); |
Todd E Brandt | bb3632c | 2014-06-06 05:40:17 -0700 | [diff] [blame] | 1174 | trace_suspend_resume(TPS("CPU_ON"), cpu, false); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1175 | if (!error) { |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1176 | pr_info("CPU%d is up\n", cpu); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1177 | continue; |
| 1178 | } |
Fabian Frederick | 84117da | 2014-06-04 16:11:17 -0700 | [diff] [blame] | 1179 | pr_warn("Error taking CPU%d up: %d\n", cpu, error); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1180 | } |
Suresh Siddha | d0af9ee | 2009-08-19 18:05:36 -0700 | [diff] [blame] | 1181 | |
| 1182 | arch_enable_nonboot_cpus_end(); |
| 1183 | |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1184 | cpumask_clear(frozen_cpus); |
Rafael J. Wysocki | 1d64b9c | 2007-04-01 23:49:49 -0700 | [diff] [blame] | 1185 | out: |
Gautham R Shenoy | d221938 | 2008-01-25 21:08:01 +0100 | [diff] [blame] | 1186 | cpu_maps_update_done(); |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 1187 | } |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1188 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 1189 | static int __init alloc_frozen_cpus(void) |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1190 | { |
| 1191 | if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) |
| 1192 | return -ENOMEM; |
| 1193 | return 0; |
| 1194 | } |
| 1195 | core_initcall(alloc_frozen_cpus); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1196 | |
| 1197 | /* |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1198 | * When callbacks for CPU hotplug notifications are being executed, we must |
| 1199 | * ensure that the state of the system with respect to the tasks being frozen |
| 1200 | * or not, as reported by the notification, remains unchanged *throughout the |
| 1201 | * duration* of the execution of the callbacks. |
| 1202 | * Hence we need to prevent the freezer from racing with regular CPU hotplug. |
| 1203 | * |
| 1204 | * This synchronization is implemented by mutually excluding regular CPU |
| 1205 | * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ |
| 1206 | * Hibernate notifications. |
| 1207 | */ |
| 1208 | static int |
| 1209 | cpu_hotplug_pm_callback(struct notifier_block *nb, |
| 1210 | unsigned long action, void *ptr) |
| 1211 | { |
| 1212 | switch (action) { |
| 1213 | |
| 1214 | case PM_SUSPEND_PREPARE: |
| 1215 | case PM_HIBERNATION_PREPARE: |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 1216 | cpu_hotplug_disable(); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1217 | break; |
| 1218 | |
| 1219 | case PM_POST_SUSPEND: |
| 1220 | case PM_POST_HIBERNATION: |
Srivatsa S. Bhat | 16e53db | 2013-06-12 14:04:36 -0700 | [diff] [blame] | 1221 | cpu_hotplug_enable(); |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1222 | break; |
| 1223 | |
| 1224 | default: |
| 1225 | return NOTIFY_DONE; |
| 1226 | } |
| 1227 | |
| 1228 | return NOTIFY_OK; |
| 1229 | } |
| 1230 | |
| 1231 | |
Fenghua Yu | d7268a3 | 2011-11-15 21:59:31 +0100 | [diff] [blame] | 1232 | static int __init cpu_hotplug_pm_sync_init(void) |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1233 | { |
Fenghua Yu | 6e32d47 | 2012-11-13 11:32:43 -0800 | [diff] [blame] | 1234 | /* |
| 1235 | * cpu_hotplug_pm_callback has higher priority than x86 |
| 1236 | * bsp_pm_callback which depends on cpu_hotplug_pm_callback |
| 1237 | * to disable cpu hotplug to avoid cpu hotplug race. |
| 1238 | */ |
Srivatsa S. Bhat | 79cfbdf | 2011-11-03 00:59:25 +0100 | [diff] [blame] | 1239 | pm_notifier(cpu_hotplug_pm_callback, 0); |
| 1240 | return 0; |
| 1241 | } |
| 1242 | core_initcall(cpu_hotplug_pm_sync_init); |
| 1243 | |
Rafael J. Wysocki | f3de4be | 2007-08-30 23:56:29 -0700 | [diff] [blame] | 1244 | #endif /* CONFIG_PM_SLEEP_SMP */ |
Max Krasnyansky | 68f4f1e | 2008-05-29 11:17:02 -0700 | [diff] [blame] | 1245 | |
| 1246 | #endif /* CONFIG_SMP */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1247 | |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1248 | /* Boot processor state steps */ |
| 1249 | static struct cpuhp_step cpuhp_bp_states[] = { |
| 1250 | [CPUHP_OFFLINE] = { |
| 1251 | .name = "offline", |
| 1252 | .startup = NULL, |
| 1253 | .teardown = NULL, |
| 1254 | }, |
| 1255 | #ifdef CONFIG_SMP |
| 1256 | [CPUHP_CREATE_THREADS]= { |
| 1257 | .name = "threads:create", |
| 1258 | .startup = smpboot_create_threads, |
| 1259 | .teardown = NULL, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1260 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1261 | }, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1262 | [CPUHP_PERF_PREPARE] = { |
| 1263 | .name = "perf prepare", |
| 1264 | .startup = perf_event_init_cpu, |
| 1265 | .teardown = perf_event_exit_cpu, |
| 1266 | }, |
Thomas Gleixner | 7ee681b | 2016-07-13 17:16:29 +0000 | [diff] [blame] | 1267 | [CPUHP_WORKQUEUE_PREP] = { |
| 1268 | .name = "workqueue prepare", |
| 1269 | .startup = workqueue_prepare_cpu, |
| 1270 | .teardown = NULL, |
| 1271 | }, |
Thomas Gleixner | 27590dc | 2016-07-15 10:41:04 +0200 | [diff] [blame] | 1272 | [CPUHP_HRTIMERS_PREPARE] = { |
| 1273 | .name = "hrtimers prepare", |
| 1274 | .startup = hrtimers_prepare_cpu, |
| 1275 | .teardown = hrtimers_dead_cpu, |
| 1276 | }, |
Richard Weinberger | 31487f8 | 2016-07-13 17:17:01 +0000 | [diff] [blame] | 1277 | [CPUHP_SMPCFD_PREPARE] = { |
| 1278 | .name = "SMPCFD prepare", |
| 1279 | .startup = smpcfd_prepare_cpu, |
| 1280 | .teardown = smpcfd_dead_cpu, |
| 1281 | }, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1282 | [CPUHP_RCUTREE_PREP] = { |
| 1283 | .name = "RCU-tree prepare", |
| 1284 | .startup = rcutree_prepare_cpu, |
| 1285 | .teardown = rcutree_dead_cpu, |
| 1286 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1287 | /* |
| 1288 | * Preparatory and dead notifiers. Will be replaced once the notifiers |
| 1289 | * are converted to states. |
| 1290 | */ |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1291 | [CPUHP_NOTIFY_PREPARE] = { |
| 1292 | .name = "notify:prepare", |
| 1293 | .startup = notify_prepare, |
| 1294 | .teardown = notify_dead, |
| 1295 | .skip_onerr = true, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1296 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1297 | }, |
Richard Cochran | 4fae16d | 2016-07-27 11:08:18 +0200 | [diff] [blame] | 1298 | /* |
| 1299 | * On the tear-down path, timers_dead_cpu() must be invoked |
| 1300 | * before blk_mq_queue_reinit_notify() from notify_dead(), |
| 1301 | * otherwise a RCU stall occurs. |
| 1302 | */ |
| 1303 | [CPUHP_TIMERS_DEAD] = { |
| 1304 | .name = "timers dead", |
| 1305 | .startup = NULL, |
| 1306 | .teardown = timers_dead_cpu, |
| 1307 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1308 | /* Kicks the plugged cpu into life */ |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1309 | [CPUHP_BRINGUP_CPU] = { |
| 1310 | .name = "cpu:bringup", |
| 1311 | .startup = bringup_cpu, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1312 | .teardown = NULL, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1313 | .cant_stop = true, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1314 | }, |
Richard Weinberger | 31487f8 | 2016-07-13 17:17:01 +0000 | [diff] [blame] | 1315 | [CPUHP_AP_SMPCFD_DYING] = { |
| 1316 | .startup = NULL, |
| 1317 | .teardown = smpcfd_dying_cpu, |
| 1318 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1319 | /* |
| 1320 | * Handled on controll processor until the plugged processor manages |
| 1321 | * this itself. |
| 1322 | */ |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1323 | [CPUHP_TEARDOWN_CPU] = { |
| 1324 | .name = "cpu:teardown", |
| 1325 | .startup = NULL, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1326 | .teardown = takedown_cpu, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1327 | .cant_stop = true, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1328 | }, |
Thomas Gleixner | a7c73414 | 2016-07-12 21:59:23 +0200 | [diff] [blame] | 1329 | #else |
| 1330 | [CPUHP_BRINGUP_CPU] = { }, |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1331 | #endif |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1332 | }; |
| 1333 | |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1334 | /* Application processor state steps */ |
| 1335 | static struct cpuhp_step cpuhp_ap_states[] = { |
| 1336 | #ifdef CONFIG_SMP |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1337 | /* Final state before CPU kills itself */ |
| 1338 | [CPUHP_AP_IDLE_DEAD] = { |
| 1339 | .name = "idle:dead", |
| 1340 | }, |
| 1341 | /* |
| 1342 | * Last state before CPU enters the idle loop to die. Transient state |
| 1343 | * for synchronization. |
| 1344 | */ |
| 1345 | [CPUHP_AP_OFFLINE] = { |
| 1346 | .name = "ap:offline", |
| 1347 | .cant_stop = true, |
| 1348 | }, |
Thomas Gleixner | 9cf7243 | 2016-03-10 12:54:09 +0100 | [diff] [blame] | 1349 | /* First state is scheduler control. Interrupts are disabled */ |
| 1350 | [CPUHP_AP_SCHED_STARTING] = { |
| 1351 | .name = "sched:starting", |
| 1352 | .startup = sched_cpu_starting, |
Thomas Gleixner | f2785dd | 2016-03-10 12:54:18 +0100 | [diff] [blame] | 1353 | .teardown = sched_cpu_dying, |
Thomas Gleixner | 9cf7243 | 2016-03-10 12:54:09 +0100 | [diff] [blame] | 1354 | }, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1355 | [CPUHP_AP_RCUTREE_DYING] = { |
| 1356 | .startup = NULL, |
| 1357 | .teardown = rcutree_dying_cpu, |
| 1358 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1359 | /* |
| 1360 | * Low level startup/teardown notifiers. Run with interrupts |
| 1361 | * disabled. Will be removed once the notifiers are converted to |
| 1362 | * states. |
| 1363 | */ |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1364 | [CPUHP_AP_NOTIFY_STARTING] = { |
| 1365 | .name = "notify:starting", |
| 1366 | .startup = notify_starting, |
| 1367 | .teardown = notify_dying, |
| 1368 | .skip_onerr = true, |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1369 | .cant_stop = true, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1370 | }, |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1371 | /* Entry state on starting. Interrupts enabled from here on. Transient |
| 1372 | * state for synchronsization */ |
| 1373 | [CPUHP_AP_ONLINE] = { |
| 1374 | .name = "ap:online", |
| 1375 | }, |
| 1376 | /* Handle smpboot threads park/unpark */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1377 | [CPUHP_AP_SMPBOOT_THREADS] = { |
| 1378 | .name = "smpboot:threads", |
| 1379 | .startup = smpboot_unpark_threads, |
Thomas Gleixner | 2a58c52 | 2016-03-10 20:42:08 +0100 | [diff] [blame] | 1380 | .teardown = NULL, |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1381 | }, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1382 | [CPUHP_AP_PERF_ONLINE] = { |
| 1383 | .name = "perf online", |
| 1384 | .startup = perf_event_init_cpu, |
| 1385 | .teardown = perf_event_exit_cpu, |
| 1386 | }, |
Thomas Gleixner | 7ee681b | 2016-07-13 17:16:29 +0000 | [diff] [blame] | 1387 | [CPUHP_AP_WORKQUEUE_ONLINE] = { |
| 1388 | .name = "workqueue online", |
| 1389 | .startup = workqueue_online_cpu, |
| 1390 | .teardown = workqueue_offline_cpu, |
| 1391 | }, |
Thomas Gleixner | 4df8374 | 2016-07-13 17:17:03 +0000 | [diff] [blame] | 1392 | [CPUHP_AP_RCUTREE_ONLINE] = { |
| 1393 | .name = "RCU-tree online", |
| 1394 | .startup = rcutree_online_cpu, |
| 1395 | .teardown = rcutree_offline_cpu, |
| 1396 | }, |
Thomas Gleixner | 00e16c3 | 2016-07-13 17:16:09 +0000 | [diff] [blame] | 1397 | |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1398 | /* |
| 1399 | * Online/down_prepare notifiers. Will be removed once the notifiers |
| 1400 | * are converted to states. |
| 1401 | */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1402 | [CPUHP_AP_NOTIFY_ONLINE] = { |
| 1403 | .name = "notify:online", |
| 1404 | .startup = notify_online, |
| 1405 | .teardown = notify_down_prepare, |
Sebastian Andrzej Siewior | 3b9d6da | 2016-04-08 14:40:15 +0200 | [diff] [blame] | 1406 | .skip_onerr = true, |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1407 | }, |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1408 | #endif |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1409 | /* |
| 1410 | * The dynamically registered state space is here |
| 1411 | */ |
| 1412 | |
Thomas Gleixner | aaddd7d | 2016-03-10 12:54:19 +0100 | [diff] [blame] | 1413 | #ifdef CONFIG_SMP |
| 1414 | /* Last state is scheduler control setting the cpu active */ |
| 1415 | [CPUHP_AP_ACTIVE] = { |
| 1416 | .name = "sched:active", |
| 1417 | .startup = sched_cpu_activate, |
| 1418 | .teardown = sched_cpu_deactivate, |
| 1419 | }, |
| 1420 | #endif |
| 1421 | |
Thomas Gleixner | d10ef6f | 2016-03-08 10:36:13 +0100 | [diff] [blame] | 1422 | /* CPU is fully up and running. */ |
Thomas Gleixner | 4baa0af | 2016-02-26 18:43:29 +0000 | [diff] [blame] | 1423 | [CPUHP_ONLINE] = { |
| 1424 | .name = "online", |
| 1425 | .startup = NULL, |
| 1426 | .teardown = NULL, |
| 1427 | }, |
| 1428 | }; |
| 1429 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1430 | /* Sanity check for callbacks */ |
| 1431 | static int cpuhp_cb_check(enum cpuhp_state state) |
| 1432 | { |
| 1433 | if (state <= CPUHP_OFFLINE || state >= CPUHP_ONLINE) |
| 1434 | return -EINVAL; |
| 1435 | return 0; |
| 1436 | } |
| 1437 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1438 | static void cpuhp_store_callbacks(enum cpuhp_state state, |
| 1439 | const char *name, |
| 1440 | int (*startup)(unsigned int cpu), |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1441 | int (*teardown)(unsigned int cpu), |
| 1442 | bool multi_instance) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1443 | { |
| 1444 | /* (Un)Install the callbacks for further cpu hotplug operations */ |
| 1445 | struct cpuhp_step *sp; |
| 1446 | |
| 1447 | mutex_lock(&cpuhp_state_mutex); |
| 1448 | sp = cpuhp_get_step(state); |
| 1449 | sp->startup = startup; |
| 1450 | sp->teardown = teardown; |
| 1451 | sp->name = name; |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1452 | sp->multi_instance = multi_instance; |
| 1453 | INIT_HLIST_HEAD(&sp->list); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1454 | mutex_unlock(&cpuhp_state_mutex); |
| 1455 | } |
| 1456 | |
| 1457 | static void *cpuhp_get_teardown_cb(enum cpuhp_state state) |
| 1458 | { |
| 1459 | return cpuhp_get_step(state)->teardown; |
| 1460 | } |
| 1461 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1462 | /* |
| 1463 | * Call the startup/teardown function for a step either on the AP or |
| 1464 | * on the current CPU. |
| 1465 | */ |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1466 | static int cpuhp_issue_call(int cpu, enum cpuhp_state state, bool bringup, |
| 1467 | struct hlist_node *node) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1468 | { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 1469 | struct cpuhp_step *sp = cpuhp_get_step(state); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1470 | int ret; |
| 1471 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 1472 | if ((bringup && !sp->startup) || (!bringup && !sp->teardown)) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1473 | return 0; |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1474 | /* |
| 1475 | * The non AP bound callbacks can fail on bringup. On teardown |
| 1476 | * e.g. module removal we crash for now. |
| 1477 | */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1478 | #ifdef CONFIG_SMP |
| 1479 | if (cpuhp_is_ap_state(state)) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1480 | ret = cpuhp_invoke_ap_callback(cpu, state, bringup, node); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1481 | else |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1482 | ret = cpuhp_invoke_callback(cpu, state, bringup, node); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1483 | #else |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1484 | ret = cpuhp_invoke_callback(cpu, state, bringup, node); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1485 | #endif |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1486 | BUG_ON(ret && !bringup); |
| 1487 | return ret; |
| 1488 | } |
| 1489 | |
| 1490 | /* |
| 1491 | * Called from __cpuhp_setup_state on a recoverable failure. |
| 1492 | * |
| 1493 | * Note: The teardown callbacks for rollback are not allowed to fail! |
| 1494 | */ |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1495 | static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state, |
| 1496 | struct hlist_node *node) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1497 | { |
| 1498 | int cpu; |
| 1499 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1500 | /* Roll back the already executed steps on the other cpus */ |
| 1501 | for_each_present_cpu(cpu) { |
| 1502 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1503 | int cpustate = st->state; |
| 1504 | |
| 1505 | if (cpu >= failedcpu) |
| 1506 | break; |
| 1507 | |
| 1508 | /* Did we invoke the startup call on that cpu ? */ |
| 1509 | if (cpustate >= state) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1510 | cpuhp_issue_call(cpu, state, false, node); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1511 | } |
| 1512 | } |
| 1513 | |
| 1514 | /* |
| 1515 | * Returns a free for dynamic slot assignment of the Online state. The states |
| 1516 | * are protected by the cpuhp_slot_states mutex and an empty slot is identified |
| 1517 | * by having no name assigned. |
| 1518 | */ |
| 1519 | static int cpuhp_reserve_state(enum cpuhp_state state) |
| 1520 | { |
| 1521 | enum cpuhp_state i; |
| 1522 | |
| 1523 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1524 | for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) { |
| 1525 | if (cpuhp_ap_states[i].name) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1526 | continue; |
| 1527 | |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1528 | cpuhp_ap_states[i].name = "Reserved"; |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1529 | mutex_unlock(&cpuhp_state_mutex); |
| 1530 | return i; |
| 1531 | } |
| 1532 | mutex_unlock(&cpuhp_state_mutex); |
| 1533 | WARN(1, "No more dynamic states available for CPU hotplug\n"); |
| 1534 | return -ENOSPC; |
| 1535 | } |
| 1536 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1537 | int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node, |
| 1538 | bool invoke) |
| 1539 | { |
| 1540 | struct cpuhp_step *sp; |
| 1541 | int cpu; |
| 1542 | int ret; |
| 1543 | |
| 1544 | sp = cpuhp_get_step(state); |
| 1545 | if (sp->multi_instance == false) |
| 1546 | return -EINVAL; |
| 1547 | |
| 1548 | get_online_cpus(); |
| 1549 | |
| 1550 | if (!invoke || !sp->startup_multi) |
| 1551 | goto add_node; |
| 1552 | |
| 1553 | /* |
| 1554 | * Try to call the startup callback for each present cpu |
| 1555 | * depending on the hotplug state of the cpu. |
| 1556 | */ |
| 1557 | for_each_present_cpu(cpu) { |
| 1558 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1559 | int cpustate = st->state; |
| 1560 | |
| 1561 | if (cpustate < state) |
| 1562 | continue; |
| 1563 | |
| 1564 | ret = cpuhp_issue_call(cpu, state, true, node); |
| 1565 | if (ret) { |
| 1566 | if (sp->teardown_multi) |
| 1567 | cpuhp_rollback_install(cpu, state, node); |
| 1568 | goto err; |
| 1569 | } |
| 1570 | } |
| 1571 | add_node: |
| 1572 | ret = 0; |
| 1573 | mutex_lock(&cpuhp_state_mutex); |
| 1574 | hlist_add_head(node, &sp->list); |
| 1575 | mutex_unlock(&cpuhp_state_mutex); |
| 1576 | |
| 1577 | err: |
| 1578 | put_online_cpus(); |
| 1579 | return ret; |
| 1580 | } |
| 1581 | EXPORT_SYMBOL_GPL(__cpuhp_state_add_instance); |
| 1582 | |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1583 | /** |
| 1584 | * __cpuhp_setup_state - Setup the callbacks for an hotplug machine state |
| 1585 | * @state: The state to setup |
| 1586 | * @invoke: If true, the startup function is invoked for cpus where |
| 1587 | * cpu state >= @state |
| 1588 | * @startup: startup callback function |
| 1589 | * @teardown: teardown callback function |
| 1590 | * |
| 1591 | * Returns 0 if successful, otherwise a proper error code |
| 1592 | */ |
| 1593 | int __cpuhp_setup_state(enum cpuhp_state state, |
| 1594 | const char *name, bool invoke, |
| 1595 | int (*startup)(unsigned int cpu), |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1596 | int (*teardown)(unsigned int cpu), |
| 1597 | bool multi_instance) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1598 | { |
| 1599 | int cpu, ret = 0; |
| 1600 | int dyn_state = 0; |
| 1601 | |
| 1602 | if (cpuhp_cb_check(state) || !name) |
| 1603 | return -EINVAL; |
| 1604 | |
| 1605 | get_online_cpus(); |
| 1606 | |
| 1607 | /* currently assignments for the ONLINE state are possible */ |
Thomas Gleixner | 1cf4f62 | 2016-02-26 18:43:39 +0000 | [diff] [blame] | 1608 | if (state == CPUHP_AP_ONLINE_DYN) { |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1609 | dyn_state = 1; |
| 1610 | ret = cpuhp_reserve_state(state); |
| 1611 | if (ret < 0) |
| 1612 | goto out; |
| 1613 | state = ret; |
| 1614 | } |
| 1615 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1616 | cpuhp_store_callbacks(state, name, startup, teardown, multi_instance); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1617 | |
| 1618 | if (!invoke || !startup) |
| 1619 | goto out; |
| 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 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1632 | ret = cpuhp_issue_call(cpu, state, true, NULL); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1633 | if (ret) { |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 1634 | if (teardown) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1635 | cpuhp_rollback_install(cpu, state, NULL); |
| 1636 | cpuhp_store_callbacks(state, NULL, NULL, NULL, false); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1637 | goto out; |
| 1638 | } |
| 1639 | } |
| 1640 | out: |
| 1641 | put_online_cpus(); |
| 1642 | if (!ret && dyn_state) |
| 1643 | return state; |
| 1644 | return ret; |
| 1645 | } |
| 1646 | EXPORT_SYMBOL(__cpuhp_setup_state); |
| 1647 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1648 | int __cpuhp_state_remove_instance(enum cpuhp_state state, |
| 1649 | struct hlist_node *node, bool invoke) |
| 1650 | { |
| 1651 | struct cpuhp_step *sp = cpuhp_get_step(state); |
| 1652 | int cpu; |
| 1653 | |
| 1654 | BUG_ON(cpuhp_cb_check(state)); |
| 1655 | |
| 1656 | if (!sp->multi_instance) |
| 1657 | return -EINVAL; |
| 1658 | |
| 1659 | get_online_cpus(); |
| 1660 | if (!invoke || !cpuhp_get_teardown_cb(state)) |
| 1661 | goto remove; |
| 1662 | /* |
| 1663 | * Call the teardown callback for each present cpu depending |
| 1664 | * on the hotplug state of the cpu. This function is not |
| 1665 | * allowed to fail currently! |
| 1666 | */ |
| 1667 | for_each_present_cpu(cpu) { |
| 1668 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1669 | int cpustate = st->state; |
| 1670 | |
| 1671 | if (cpustate >= state) |
| 1672 | cpuhp_issue_call(cpu, state, false, node); |
| 1673 | } |
| 1674 | |
| 1675 | remove: |
| 1676 | mutex_lock(&cpuhp_state_mutex); |
| 1677 | hlist_del(node); |
| 1678 | mutex_unlock(&cpuhp_state_mutex); |
| 1679 | put_online_cpus(); |
| 1680 | |
| 1681 | return 0; |
| 1682 | } |
| 1683 | EXPORT_SYMBOL_GPL(__cpuhp_state_remove_instance); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1684 | /** |
| 1685 | * __cpuhp_remove_state - Remove the callbacks for an hotplug machine state |
| 1686 | * @state: The state to remove |
| 1687 | * @invoke: If true, the teardown function is invoked for cpus where |
| 1688 | * cpu state >= @state |
| 1689 | * |
| 1690 | * The teardown callback is currently not allowed to fail. Think |
| 1691 | * about module removal! |
| 1692 | */ |
| 1693 | void __cpuhp_remove_state(enum cpuhp_state state, bool invoke) |
| 1694 | { |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1695 | struct cpuhp_step *sp = cpuhp_get_step(state); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1696 | int cpu; |
| 1697 | |
| 1698 | BUG_ON(cpuhp_cb_check(state)); |
| 1699 | |
| 1700 | get_online_cpus(); |
| 1701 | |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1702 | if (sp->multi_instance) { |
| 1703 | WARN(!hlist_empty(&sp->list), |
| 1704 | "Error: Removing state %d which has instances left.\n", |
| 1705 | state); |
| 1706 | goto remove; |
| 1707 | } |
| 1708 | |
Thomas Gleixner | a724632 | 2016-08-12 19:49:38 +0200 | [diff] [blame] | 1709 | if (!invoke || !cpuhp_get_teardown_cb(state)) |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1710 | goto remove; |
| 1711 | |
| 1712 | /* |
| 1713 | * Call the teardown callback for each present cpu depending |
| 1714 | * on the hotplug state of the cpu. This function is not |
| 1715 | * allowed to fail currently! |
| 1716 | */ |
| 1717 | for_each_present_cpu(cpu) { |
| 1718 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
| 1719 | int cpustate = st->state; |
| 1720 | |
| 1721 | if (cpustate >= state) |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1722 | cpuhp_issue_call(cpu, state, false, NULL); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1723 | } |
| 1724 | remove: |
Thomas Gleixner | cf392d1 | 2016-08-12 19:49:39 +0200 | [diff] [blame^] | 1725 | cpuhp_store_callbacks(state, NULL, NULL, NULL, false); |
Thomas Gleixner | 5b7aa87 | 2016-02-26 18:43:33 +0000 | [diff] [blame] | 1726 | put_online_cpus(); |
| 1727 | } |
| 1728 | EXPORT_SYMBOL(__cpuhp_remove_state); |
| 1729 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1730 | #if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU) |
| 1731 | static ssize_t show_cpuhp_state(struct device *dev, |
| 1732 | struct device_attribute *attr, char *buf) |
| 1733 | { |
| 1734 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1735 | |
| 1736 | return sprintf(buf, "%d\n", st->state); |
| 1737 | } |
| 1738 | static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL); |
| 1739 | |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1740 | static ssize_t write_cpuhp_target(struct device *dev, |
| 1741 | struct device_attribute *attr, |
| 1742 | const char *buf, size_t count) |
| 1743 | { |
| 1744 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1745 | struct cpuhp_step *sp; |
| 1746 | int target, ret; |
| 1747 | |
| 1748 | ret = kstrtoint(buf, 10, &target); |
| 1749 | if (ret) |
| 1750 | return ret; |
| 1751 | |
| 1752 | #ifdef CONFIG_CPU_HOTPLUG_STATE_CONTROL |
| 1753 | if (target < CPUHP_OFFLINE || target > CPUHP_ONLINE) |
| 1754 | return -EINVAL; |
| 1755 | #else |
| 1756 | if (target != CPUHP_OFFLINE && target != CPUHP_ONLINE) |
| 1757 | return -EINVAL; |
| 1758 | #endif |
| 1759 | |
| 1760 | ret = lock_device_hotplug_sysfs(); |
| 1761 | if (ret) |
| 1762 | return ret; |
| 1763 | |
| 1764 | mutex_lock(&cpuhp_state_mutex); |
| 1765 | sp = cpuhp_get_step(target); |
| 1766 | ret = !sp->name || sp->cant_stop ? -EINVAL : 0; |
| 1767 | mutex_unlock(&cpuhp_state_mutex); |
| 1768 | if (ret) |
| 1769 | return ret; |
| 1770 | |
| 1771 | if (st->state < target) |
| 1772 | ret = do_cpu_up(dev->id, target); |
| 1773 | else |
| 1774 | ret = do_cpu_down(dev->id, target); |
| 1775 | |
| 1776 | unlock_device_hotplug(); |
| 1777 | return ret ? ret : count; |
| 1778 | } |
| 1779 | |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1780 | static ssize_t show_cpuhp_target(struct device *dev, |
| 1781 | struct device_attribute *attr, char *buf) |
| 1782 | { |
| 1783 | struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); |
| 1784 | |
| 1785 | return sprintf(buf, "%d\n", st->target); |
| 1786 | } |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1787 | static DEVICE_ATTR(target, 0644, show_cpuhp_target, write_cpuhp_target); |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1788 | |
| 1789 | static struct attribute *cpuhp_cpu_attrs[] = { |
| 1790 | &dev_attr_state.attr, |
| 1791 | &dev_attr_target.attr, |
| 1792 | NULL |
| 1793 | }; |
| 1794 | |
| 1795 | static struct attribute_group cpuhp_cpu_attr_group = { |
| 1796 | .attrs = cpuhp_cpu_attrs, |
| 1797 | .name = "hotplug", |
| 1798 | NULL |
| 1799 | }; |
| 1800 | |
| 1801 | static ssize_t show_cpuhp_states(struct device *dev, |
| 1802 | struct device_attribute *attr, char *buf) |
| 1803 | { |
| 1804 | ssize_t cur, res = 0; |
| 1805 | int i; |
| 1806 | |
| 1807 | mutex_lock(&cpuhp_state_mutex); |
Thomas Gleixner | 757c989 | 2016-02-26 18:43:32 +0000 | [diff] [blame] | 1808 | for (i = CPUHP_OFFLINE; i <= CPUHP_ONLINE; i++) { |
Thomas Gleixner | 98f8cdc | 2016-02-26 18:43:31 +0000 | [diff] [blame] | 1809 | struct cpuhp_step *sp = cpuhp_get_step(i); |
| 1810 | |
| 1811 | if (sp->name) { |
| 1812 | cur = sprintf(buf, "%3d: %s\n", i, sp->name); |
| 1813 | buf += cur; |
| 1814 | res += cur; |
| 1815 | } |
| 1816 | } |
| 1817 | mutex_unlock(&cpuhp_state_mutex); |
| 1818 | return res; |
| 1819 | } |
| 1820 | static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL); |
| 1821 | |
| 1822 | static struct attribute *cpuhp_cpu_root_attrs[] = { |
| 1823 | &dev_attr_states.attr, |
| 1824 | NULL |
| 1825 | }; |
| 1826 | |
| 1827 | static struct attribute_group cpuhp_cpu_root_attr_group = { |
| 1828 | .attrs = cpuhp_cpu_root_attrs, |
| 1829 | .name = "hotplug", |
| 1830 | NULL |
| 1831 | }; |
| 1832 | |
| 1833 | static int __init cpuhp_sysfs_init(void) |
| 1834 | { |
| 1835 | int cpu, ret; |
| 1836 | |
| 1837 | ret = sysfs_create_group(&cpu_subsys.dev_root->kobj, |
| 1838 | &cpuhp_cpu_root_attr_group); |
| 1839 | if (ret) |
| 1840 | return ret; |
| 1841 | |
| 1842 | for_each_possible_cpu(cpu) { |
| 1843 | struct device *dev = get_cpu_device(cpu); |
| 1844 | |
| 1845 | if (!dev) |
| 1846 | continue; |
| 1847 | ret = sysfs_create_group(&dev->kobj, &cpuhp_cpu_attr_group); |
| 1848 | if (ret) |
| 1849 | return ret; |
| 1850 | } |
| 1851 | return 0; |
| 1852 | } |
| 1853 | device_initcall(cpuhp_sysfs_init); |
| 1854 | #endif |
| 1855 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1856 | /* |
| 1857 | * cpu_bit_bitmap[] is a special, "compressed" data structure that |
| 1858 | * represents all NR_CPUS bits binary values of 1<<nr. |
| 1859 | * |
Rusty Russell | e0b582e | 2009-01-01 10:12:28 +1030 | [diff] [blame] | 1860 | * 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] | 1861 | * mask value that has a single bit set only. |
| 1862 | */ |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1863 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1864 | /* cpu_bit_bitmap[0] is empty - so we can back into it */ |
Michael Rodriguez | 4d51985 | 2011-03-22 16:34:07 -0700 | [diff] [blame] | 1865 | #define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1866 | #define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) |
| 1867 | #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) |
| 1868 | #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] | 1869 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1870 | 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] | 1871 | |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1872 | MASK_DECLARE_8(0), MASK_DECLARE_8(8), |
| 1873 | MASK_DECLARE_8(16), MASK_DECLARE_8(24), |
| 1874 | #if BITS_PER_LONG > 32 |
| 1875 | MASK_DECLARE_8(32), MASK_DECLARE_8(40), |
| 1876 | MASK_DECLARE_8(48), MASK_DECLARE_8(56), |
Mike Travis | b8d317d | 2008-07-24 18:21:29 -0700 | [diff] [blame] | 1877 | #endif |
| 1878 | }; |
Linus Torvalds | e56b3bc | 2008-07-28 11:32:33 -0700 | [diff] [blame] | 1879 | EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
Rusty Russell | 2d3854a | 2008-11-05 13:39:10 +1100 | [diff] [blame] | 1880 | |
| 1881 | const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; |
| 1882 | EXPORT_SYMBOL(cpu_all_bits); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1883 | |
| 1884 | #ifdef CONFIG_INIT_ALL_POSSIBLE |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1885 | struct cpumask __cpu_possible_mask __read_mostly |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1886 | = {CPU_BITS_ALL}; |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1887 | #else |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1888 | struct cpumask __cpu_possible_mask __read_mostly; |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1889 | #endif |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1890 | EXPORT_SYMBOL(__cpu_possible_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1891 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1892 | struct cpumask __cpu_online_mask __read_mostly; |
| 1893 | EXPORT_SYMBOL(__cpu_online_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1894 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1895 | struct cpumask __cpu_present_mask __read_mostly; |
| 1896 | EXPORT_SYMBOL(__cpu_present_mask); |
Rusty Russell | b3199c0 | 2008-12-30 09:05:14 +1030 | [diff] [blame] | 1897 | |
Rasmus Villemoes | 4b804c8 | 2016-01-20 15:00:19 -0800 | [diff] [blame] | 1898 | struct cpumask __cpu_active_mask __read_mostly; |
| 1899 | EXPORT_SYMBOL(__cpu_active_mask); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1900 | |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1901 | void init_cpu_present(const struct cpumask *src) |
| 1902 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1903 | cpumask_copy(&__cpu_present_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1904 | } |
| 1905 | |
| 1906 | void init_cpu_possible(const struct cpumask *src) |
| 1907 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1908 | cpumask_copy(&__cpu_possible_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1909 | } |
| 1910 | |
| 1911 | void init_cpu_online(const struct cpumask *src) |
| 1912 | { |
Rasmus Villemoes | c4c54dd | 2016-01-20 15:00:16 -0800 | [diff] [blame] | 1913 | cpumask_copy(&__cpu_online_mask, src); |
Rusty Russell | 3fa4152 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 1914 | } |
Thomas Gleixner | cff7d37 | 2016-02-26 18:43:28 +0000 | [diff] [blame] | 1915 | |
| 1916 | /* |
| 1917 | * Activate the first processor. |
| 1918 | */ |
| 1919 | void __init boot_cpu_init(void) |
| 1920 | { |
| 1921 | int cpu = smp_processor_id(); |
| 1922 | |
| 1923 | /* Mark the boot cpu "present", "online" etc for SMP and UP case */ |
| 1924 | set_cpu_online(cpu, true); |
| 1925 | set_cpu_active(cpu, true); |
| 1926 | set_cpu_present(cpu, true); |
| 1927 | set_cpu_possible(cpu, true); |
| 1928 | } |
| 1929 | |
| 1930 | /* |
| 1931 | * Must be called _AFTER_ setting up the per_cpu areas |
| 1932 | */ |
| 1933 | void __init boot_cpu_state_init(void) |
| 1934 | { |
| 1935 | per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE; |
| 1936 | } |