blob: 8e218500ab14b7ff0a91810b5bc34abbd64e2a7b [file] [log] [blame]
Jens Axboe3d442232008-06-26 11:21:34 +02001/*
2 * Generic helpers for smp ipi calls
3 *
4 * (C) Jens Axboe <jens.axboe@oracle.com> 2008
Jens Axboe3d442232008-06-26 11:21:34 +02005 */
Jens Axboe3d442232008-06-26 11:21:34 +02006#include <linux/rcupdate.h>
Linus Torvalds59190f42008-07-15 14:02:33 -07007#include <linux/rculist.h>
Ingo Molnar641cd4c2009-03-13 10:47:34 +01008#include <linux/kernel.h>
Ingo Molnar0b13fda2009-02-25 16:52:11 +01009#include <linux/module.h>
10#include <linux/percpu.h>
11#include <linux/init.h>
Jens Axboe3d442232008-06-26 11:21:34 +020012#include <linux/smp.h>
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010013#include <linux/cpu.h>
Jens Axboe3d442232008-06-26 11:21:34 +020014
15static DEFINE_PER_CPU(struct call_single_queue, call_single_queue);
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010016
17static struct {
18 struct list_head queue;
19 spinlock_t lock;
Ingo Molnar0b13fda2009-02-25 16:52:11 +010020} call_function __cacheline_aligned_in_smp =
21 {
22 .queue = LIST_HEAD_INIT(call_function.queue),
23 .lock = __SPIN_LOCK_UNLOCKED(call_function.lock),
24 };
Jens Axboe3d442232008-06-26 11:21:34 +020025
26enum {
Peter Zijlstra6e275632009-02-25 13:59:48 +010027 CSD_FLAG_LOCK = 0x01,
Jens Axboe3d442232008-06-26 11:21:34 +020028};
29
30struct call_function_data {
Ingo Molnar0b13fda2009-02-25 16:52:11 +010031 struct call_single_data csd;
32 spinlock_t lock;
33 unsigned int refs;
34 cpumask_var_t cpumask;
Jens Axboe3d442232008-06-26 11:21:34 +020035};
36
37struct call_single_queue {
Ingo Molnar0b13fda2009-02-25 16:52:11 +010038 struct list_head list;
39 spinlock_t lock;
Jens Axboe3d442232008-06-26 11:21:34 +020040};
41
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010042static DEFINE_PER_CPU(struct call_function_data, cfd_data) = {
Ingo Molnar0b13fda2009-02-25 16:52:11 +010043 .lock = __SPIN_LOCK_UNLOCKED(cfd_data.lock),
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010044};
45
46static int
47hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
48{
49 long cpu = (long)hcpu;
50 struct call_function_data *cfd = &per_cpu(cfd_data, cpu);
51
52 switch (action) {
53 case CPU_UP_PREPARE:
54 case CPU_UP_PREPARE_FROZEN:
Yinghai Lueaa95842009-06-06 14:51:36 -070055 if (!zalloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL,
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010056 cpu_to_node(cpu)))
57 return NOTIFY_BAD;
58 break;
59
Xiao Guangrong69dd6472009-08-06 15:07:29 -070060#ifdef CONFIG_HOTPLUG_CPU
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010061 case CPU_UP_CANCELED:
62 case CPU_UP_CANCELED_FROZEN:
63
64 case CPU_DEAD:
65 case CPU_DEAD_FROZEN:
66 free_cpumask_var(cfd->cpumask);
67 break;
68#endif
69 };
70
71 return NOTIFY_OK;
72}
73
74static struct notifier_block __cpuinitdata hotplug_cfd_notifier = {
Ingo Molnar0b13fda2009-02-25 16:52:11 +010075 .notifier_call = hotplug_cfd,
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010076};
77
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -070078static int __cpuinit init_call_single_data(void)
Jens Axboe3d442232008-06-26 11:21:34 +020079{
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010080 void *cpu = (void *)(long)smp_processor_id();
Jens Axboe3d442232008-06-26 11:21:34 +020081 int i;
82
83 for_each_possible_cpu(i) {
84 struct call_single_queue *q = &per_cpu(call_single_queue, i);
85
86 spin_lock_init(&q->lock);
87 INIT_LIST_HEAD(&q->list);
88 }
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010089
90 hotplug_cfd(&hotplug_cfd_notifier, CPU_UP_PREPARE, cpu);
91 register_cpu_notifier(&hotplug_cfd_notifier);
92
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -070093 return 0;
Jens Axboe3d442232008-06-26 11:21:34 +020094}
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -070095early_initcall(init_call_single_data);
Jens Axboe3d442232008-06-26 11:21:34 +020096
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010097/*
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010098 * csd_lock/csd_unlock used to serialize access to per-cpu csd resources
99 *
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100100 * For non-synchronous ipi calls the csd can still be in use by the
101 * previous function call. For multi-cpu calls its even more interesting
102 * as we'll have to ensure no other cpu is observing our csd.
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100103 */
Peter Zijlstra6e275632009-02-25 13:59:48 +0100104static void csd_lock_wait(struct call_single_data *data)
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100105{
106 while (data->flags & CSD_FLAG_LOCK)
107 cpu_relax();
Peter Zijlstra6e275632009-02-25 13:59:48 +0100108}
109
110static void csd_lock(struct call_single_data *data)
111{
112 csd_lock_wait(data);
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100113 data->flags = CSD_FLAG_LOCK;
114
115 /*
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100116 * prevent CPU from reordering the above assignment
117 * to ->flags with any subsequent assignments to other
118 * fields of the specified call_single_data structure:
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100119 */
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100120 smp_mb();
121}
122
123static void csd_unlock(struct call_single_data *data)
124{
125 WARN_ON(!(data->flags & CSD_FLAG_LOCK));
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100126
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100127 /*
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100128 * ensure we're all done before releasing data:
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100129 */
130 smp_mb();
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100131
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100132 data->flags &= ~CSD_FLAG_LOCK;
Jens Axboe3d442232008-06-26 11:21:34 +0200133}
134
135/*
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100136 * Insert a previously allocated call_single_data element
137 * for execution on the given CPU. data must already have
138 * ->func, ->info, and ->flags set.
Jens Axboe3d442232008-06-26 11:21:34 +0200139 */
Peter Zijlstra6e275632009-02-25 13:59:48 +0100140static
141void generic_exec_single(int cpu, struct call_single_data *data, int wait)
Jens Axboe3d442232008-06-26 11:21:34 +0200142{
143 struct call_single_queue *dst = &per_cpu(call_single_queue, cpu);
Jens Axboe3d442232008-06-26 11:21:34 +0200144 unsigned long flags;
Peter Zijlstra6e275632009-02-25 13:59:48 +0100145 int ipi;
Jens Axboe3d442232008-06-26 11:21:34 +0200146
147 spin_lock_irqsave(&dst->lock, flags);
148 ipi = list_empty(&dst->list);
149 list_add_tail(&data->list, &dst->list);
150 spin_unlock_irqrestore(&dst->lock, flags);
151
Suresh Siddha561920a02008-10-30 18:28:41 +0100152 /*
Nick Piggin15d0d3b2009-02-25 06:22:45 +0100153 * The list addition should be visible before sending the IPI
154 * handler locks the list to pull the entry off it because of
155 * normal cache coherency rules implied by spinlocks.
156 *
157 * If IPIs can go out of order to the cache coherency protocol
158 * in an architecture, sufficient synchronisation should be added
159 * to arch code to make it appear to obey cache coherency WRT
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100160 * locking and barrier primitives. Generic code isn't really
161 * equipped to do the right thing...
Suresh Siddha561920a02008-10-30 18:28:41 +0100162 */
Jens Axboe3d442232008-06-26 11:21:34 +0200163 if (ipi)
164 arch_send_call_function_single_ipi(cpu);
165
166 if (wait)
Peter Zijlstra6e275632009-02-25 13:59:48 +0100167 csd_lock_wait(data);
Jens Axboe3d442232008-06-26 11:21:34 +0200168}
169
170/*
171 * Invoked by arch to handle an IPI for call function. Must be called with
172 * interrupts disabled.
173 */
174void generic_smp_call_function_interrupt(void)
175{
176 struct call_function_data *data;
177 int cpu = get_cpu();
178
179 /*
Suresh Siddha269c8612009-08-19 18:05:35 -0700180 * Shouldn't receive this interrupt on a cpu that is not yet online.
181 */
182 WARN_ON_ONCE(!cpu_online(cpu));
183
184 /*
Nick Piggin15d0d3b2009-02-25 06:22:45 +0100185 * Ensure entry is visible on call_function_queue after we have
186 * entered the IPI. See comment in smp_call_function_many.
187 * If we don't have this, then we may miss an entry on the list
188 * and never get another IPI to process it.
189 */
190 smp_mb();
191
192 /*
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100193 * It's ok to use list_for_each_rcu() here even though we may
194 * delete 'pos', since list_del_rcu() doesn't clear ->next
Jens Axboe3d442232008-06-26 11:21:34 +0200195 */
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100196 list_for_each_entry_rcu(data, &call_function.queue, csd.list) {
Jens Axboe3d442232008-06-26 11:21:34 +0200197 int refs;
198
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100199 spin_lock(&data->lock);
200 if (!cpumask_test_cpu(cpu, data->cpumask)) {
201 spin_unlock(&data->lock);
Jens Axboe3d442232008-06-26 11:21:34 +0200202 continue;
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100203 }
204 cpumask_clear_cpu(cpu, data->cpumask);
205 spin_unlock(&data->lock);
Jens Axboe3d442232008-06-26 11:21:34 +0200206
207 data->csd.func(data->csd.info);
208
209 spin_lock(&data->lock);
Jens Axboe3d442232008-06-26 11:21:34 +0200210 WARN_ON(data->refs == 0);
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100211 refs = --data->refs;
212 if (!refs) {
213 spin_lock(&call_function.lock);
214 list_del_rcu(&data->csd.list);
215 spin_unlock(&call_function.lock);
216 }
Jens Axboe3d442232008-06-26 11:21:34 +0200217 spin_unlock(&data->lock);
218
219 if (refs)
220 continue;
221
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100222 csd_unlock(&data->csd);
Jens Axboe3d442232008-06-26 11:21:34 +0200223 }
Jens Axboe3d442232008-06-26 11:21:34 +0200224
225 put_cpu();
226}
227
228/*
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100229 * Invoked by arch to handle an IPI for call function single. Must be
230 * called from the arch with interrupts disabled.
Jens Axboe3d442232008-06-26 11:21:34 +0200231 */
232void generic_smp_call_function_single_interrupt(void)
233{
234 struct call_single_queue *q = &__get_cpu_var(call_single_queue);
Nick Piggin15d0d3b2009-02-25 06:22:45 +0100235 unsigned int data_flags;
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100236 LIST_HEAD(list);
Jens Axboe3d442232008-06-26 11:21:34 +0200237
Suresh Siddha269c8612009-08-19 18:05:35 -0700238 /*
239 * Shouldn't receive this interrupt on a cpu that is not yet online.
240 */
241 WARN_ON_ONCE(!cpu_online(smp_processor_id()));
242
Nick Piggin15d0d3b2009-02-25 06:22:45 +0100243 spin_lock(&q->lock);
244 list_replace_init(&q->list, &list);
245 spin_unlock(&q->lock);
Jens Axboe3d442232008-06-26 11:21:34 +0200246
Nick Piggin15d0d3b2009-02-25 06:22:45 +0100247 while (!list_empty(&list)) {
248 struct call_single_data *data;
Jens Axboe3d442232008-06-26 11:21:34 +0200249
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100250 data = list_entry(list.next, struct call_single_data, list);
Nick Piggin15d0d3b2009-02-25 06:22:45 +0100251 list_del(&data->list);
Jens Axboe3d442232008-06-26 11:21:34 +0200252
Jens Axboe3d442232008-06-26 11:21:34 +0200253 /*
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100254 * 'data' can be invalid after this call if flags == 0
255 * (when called through generic_exec_single()),
256 * so save them away before making the call:
Jens Axboe3d442232008-06-26 11:21:34 +0200257 */
Nick Piggin15d0d3b2009-02-25 06:22:45 +0100258 data_flags = data->flags;
259
260 data->func(data->info);
261
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100262 /*
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100263 * Unlocked CSDs are valid through generic_exec_single():
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100264 */
265 if (data_flags & CSD_FLAG_LOCK)
266 csd_unlock(data);
Jens Axboe3d442232008-06-26 11:21:34 +0200267 }
268}
269
Steven Rostedtd7240b92009-01-29 10:08:01 -0500270static DEFINE_PER_CPU(struct call_single_data, csd_data);
271
Jens Axboe3d442232008-06-26 11:21:34 +0200272/*
273 * smp_call_function_single - Run a function on a specific CPU
274 * @func: The function to run. This must be fast and non-blocking.
275 * @info: An arbitrary pointer to pass to the function.
Jens Axboe3d442232008-06-26 11:21:34 +0200276 * @wait: If true, wait until function has completed on other CPUs.
277 *
278 * Returns 0 on success, else a negative status code. Note that @wait
279 * will be implicitly turned on in case of allocation failures, since
280 * we fall back to on-stack allocation.
281 */
282int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
Jens Axboe8691e5a2008-06-06 11:18:06 +0200283 int wait)
Jens Axboe3d442232008-06-26 11:21:34 +0200284{
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100285 struct call_single_data d = {
286 .flags = 0,
287 };
Jens Axboe3d442232008-06-26 11:21:34 +0200288 unsigned long flags;
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100289 int this_cpu;
H. Peter Anvinf73be6d2008-08-25 17:07:14 -0700290 int err = 0;
Jens Axboe3d442232008-06-26 11:21:34 +0200291
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100292 /*
293 * prevent preemption and reschedule on another processor,
294 * as well as CPU removal
295 */
296 this_cpu = get_cpu();
297
Suresh Siddha269c8612009-08-19 18:05:35 -0700298 /*
299 * Can deadlock when called with interrupts disabled.
300 * We allow cpu's that are not yet online though, as no one else can
301 * send smp call function interrupt to this cpu and as such deadlocks
302 * can't happen.
303 */
304 WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
305 && !oops_in_progress);
Jens Axboe3d442232008-06-26 11:21:34 +0200306
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100307 if (cpu == this_cpu) {
Jens Axboe3d442232008-06-26 11:21:34 +0200308 local_irq_save(flags);
309 func(info);
310 local_irq_restore(flags);
H. Peter Anvinf73be6d2008-08-25 17:07:14 -0700311 } else {
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100312 if ((unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) {
313 struct call_single_data *data = &d;
314
315 if (!wait)
316 data = &__get_cpu_var(csd_data);
317
318 csd_lock(data);
319
320 data->func = func;
321 data->info = info;
322 generic_exec_single(cpu, data, wait);
323 } else {
324 err = -ENXIO; /* CPU not online */
325 }
Jens Axboe3d442232008-06-26 11:21:34 +0200326 }
327
328 put_cpu();
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100329
H. Peter Anvinf73be6d2008-08-25 17:07:14 -0700330 return err;
Jens Axboe3d442232008-06-26 11:21:34 +0200331}
332EXPORT_SYMBOL(smp_call_function_single);
333
334/**
335 * __smp_call_function_single(): Run a function on another CPU
336 * @cpu: The CPU to run on.
337 * @data: Pre-allocated and setup data structure
338 *
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100339 * Like smp_call_function_single(), but allow caller to pass in a
340 * pre-allocated data structure. Useful for embedding @data inside
341 * other structures, for instance.
Jens Axboe3d442232008-06-26 11:21:34 +0200342 */
Peter Zijlstra6e275632009-02-25 13:59:48 +0100343void __smp_call_function_single(int cpu, struct call_single_data *data,
344 int wait)
Jens Axboe3d442232008-06-26 11:21:34 +0200345{
Peter Zijlstra6e275632009-02-25 13:59:48 +0100346 csd_lock(data);
Jens Axboe3d442232008-06-26 11:21:34 +0200347
Suresh Siddha269c8612009-08-19 18:05:35 -0700348 /*
349 * Can deadlock when called with interrupts disabled.
350 * We allow cpu's that are not yet online though, as no one else can
351 * send smp call function interrupt to this cpu and as such deadlocks
352 * can't happen.
353 */
354 WARN_ON_ONCE(cpu_online(smp_processor_id()) && wait && irqs_disabled()
355 && !oops_in_progress);
Peter Zijlstra6e275632009-02-25 13:59:48 +0100356
357 generic_exec_single(cpu, data, wait);
Jens Axboe3d442232008-06-26 11:21:34 +0200358}
359
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100360/* Deprecated: shim for archs using old arch_send_call_function_ipi API. */
361
Rusty Russellce47d972008-12-30 09:05:17 +1030362#ifndef arch_send_call_function_ipi_mask
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100363# define arch_send_call_function_ipi_mask(maskp) \
364 arch_send_call_function_ipi(*(maskp))
Rusty Russellce47d972008-12-30 09:05:17 +1030365#endif
366
Jens Axboe3d442232008-06-26 11:21:34 +0200367/**
Rusty Russell54b11e62008-12-30 09:05:16 +1030368 * smp_call_function_many(): Run a function on a set of other CPUs.
369 * @mask: The set of cpus to run on (only runs on online subset).
Jens Axboe3d442232008-06-26 11:21:34 +0200370 * @func: The function to run. This must be fast and non-blocking.
371 * @info: An arbitrary pointer to pass to the function.
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100372 * @wait: If true, wait (atomically) until function has completed
373 * on other CPUs.
Jens Axboe3d442232008-06-26 11:21:34 +0200374 *
Jens Axboe3d442232008-06-26 11:21:34 +0200375 * If @wait is true, then returns once @func has returned. Note that @wait
376 * will be implicitly turned on in case of allocation failures, since
377 * we fall back to on-stack allocation.
378 *
379 * You must not call this function with disabled interrupts or from a
380 * hardware interrupt handler or from a bottom half handler. Preemption
381 * must be disabled when calling this function.
382 */
Rusty Russell54b11e62008-12-30 09:05:16 +1030383void smp_call_function_many(const struct cpumask *mask,
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100384 void (*func)(void *), void *info, bool wait)
Jens Axboe3d442232008-06-26 11:21:34 +0200385{
Rusty Russell54b11e62008-12-30 09:05:16 +1030386 struct call_function_data *data;
Jens Axboe3d442232008-06-26 11:21:34 +0200387 unsigned long flags;
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100388 int cpu, next_cpu, this_cpu = smp_processor_id();
Jens Axboe3d442232008-06-26 11:21:34 +0200389
Suresh Siddha269c8612009-08-19 18:05:35 -0700390 /*
391 * Can deadlock when called with interrupts disabled.
392 * We allow cpu's that are not yet online though, as no one else can
393 * send smp call function interrupt to this cpu and as such deadlocks
394 * can't happen.
395 */
396 WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
397 && !oops_in_progress);
Jens Axboe3d442232008-06-26 11:21:34 +0200398
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100399 /* So, what's a CPU they want? Ignoring this one. */
Rusty Russell54b11e62008-12-30 09:05:16 +1030400 cpu = cpumask_first_and(mask, cpu_online_mask);
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100401 if (cpu == this_cpu)
Rusty Russell54b11e62008-12-30 09:05:16 +1030402 cpu = cpumask_next_and(cpu, mask, cpu_online_mask);
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100403
Rusty Russell54b11e62008-12-30 09:05:16 +1030404 /* No online cpus? We're done. */
405 if (cpu >= nr_cpu_ids)
406 return;
Jens Axboe3d442232008-06-26 11:21:34 +0200407
Rusty Russell54b11e62008-12-30 09:05:16 +1030408 /* Do we have another CPU which isn't us? */
409 next_cpu = cpumask_next_and(cpu, mask, cpu_online_mask);
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100410 if (next_cpu == this_cpu)
Rusty Russell54b11e62008-12-30 09:05:16 +1030411 next_cpu = cpumask_next_and(next_cpu, mask, cpu_online_mask);
412
413 /* Fastpath: do that cpu by itself. */
414 if (next_cpu >= nr_cpu_ids) {
415 smp_call_function_single(cpu, func, info, wait);
416 return;
Jens Axboe3d442232008-06-26 11:21:34 +0200417 }
418
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100419 data = &__get_cpu_var(cfd_data);
420 csd_lock(&data->csd);
Jens Axboe3d442232008-06-26 11:21:34 +0200421
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100422 spin_lock_irqsave(&data->lock, flags);
Jens Axboe3d442232008-06-26 11:21:34 +0200423 data->csd.func = func;
424 data->csd.info = info;
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100425 cpumask_and(data->cpumask, mask, cpu_online_mask);
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100426 cpumask_clear_cpu(this_cpu, data->cpumask);
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100427 data->refs = cpumask_weight(data->cpumask);
Jens Axboe3d442232008-06-26 11:21:34 +0200428
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100429 spin_lock(&call_function.lock);
430 /*
431 * Place entry at the _HEAD_ of the list, so that any cpu still
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100432 * observing the entry in generic_smp_call_function_interrupt()
433 * will not miss any other list entries:
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100434 */
435 list_add_rcu(&data->csd.list, &call_function.queue);
436 spin_unlock(&call_function.lock);
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100437
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100438 spin_unlock_irqrestore(&data->lock, flags);
Jens Axboe3d442232008-06-26 11:21:34 +0200439
Suresh Siddha561920a02008-10-30 18:28:41 +0100440 /*
441 * Make the list addition visible before sending the ipi.
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100442 * (IPIs must obey or appear to obey normal Linux cache
443 * coherency rules -- see comment in generic_exec_single).
Suresh Siddha561920a02008-10-30 18:28:41 +0100444 */
445 smp_mb();
446
Jens Axboe3d442232008-06-26 11:21:34 +0200447 /* Send a message to all CPUs in the map */
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100448 arch_send_call_function_ipi_mask(data->cpumask);
Jens Axboe3d442232008-06-26 11:21:34 +0200449
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100450 /* Optionally wait for the CPUs to complete */
Rusty Russell54b11e62008-12-30 09:05:16 +1030451 if (wait)
Peter Zijlstra6e275632009-02-25 13:59:48 +0100452 csd_lock_wait(&data->csd);
Jens Axboe3d442232008-06-26 11:21:34 +0200453}
Rusty Russell54b11e62008-12-30 09:05:16 +1030454EXPORT_SYMBOL(smp_call_function_many);
Jens Axboe3d442232008-06-26 11:21:34 +0200455
456/**
457 * smp_call_function(): Run a function on all other CPUs.
458 * @func: The function to run. This must be fast and non-blocking.
459 * @info: An arbitrary pointer to pass to the function.
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100460 * @wait: If true, wait (atomically) until function has completed
461 * on other CPUs.
Jens Axboe3d442232008-06-26 11:21:34 +0200462 *
Rusty Russell54b11e62008-12-30 09:05:16 +1030463 * Returns 0.
Jens Axboe3d442232008-06-26 11:21:34 +0200464 *
465 * If @wait is true, then returns once @func has returned; otherwise
466 * it returns just before the target cpu calls @func. In case of allocation
467 * failure, @wait will be implicitly turned on.
468 *
469 * You must not call this function with disabled interrupts or from a
470 * hardware interrupt handler or from a bottom half handler.
471 */
Jens Axboe8691e5a2008-06-06 11:18:06 +0200472int smp_call_function(void (*func)(void *), void *info, int wait)
Jens Axboe3d442232008-06-26 11:21:34 +0200473{
Jens Axboe3d442232008-06-26 11:21:34 +0200474 preempt_disable();
Rusty Russell54b11e62008-12-30 09:05:16 +1030475 smp_call_function_many(cpu_online_mask, func, info, wait);
Jens Axboe3d442232008-06-26 11:21:34 +0200476 preempt_enable();
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100477
Rusty Russell54b11e62008-12-30 09:05:16 +1030478 return 0;
Jens Axboe3d442232008-06-26 11:21:34 +0200479}
480EXPORT_SYMBOL(smp_call_function);
481
482void ipi_call_lock(void)
483{
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100484 spin_lock(&call_function.lock);
Jens Axboe3d442232008-06-26 11:21:34 +0200485}
486
487void ipi_call_unlock(void)
488{
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100489 spin_unlock(&call_function.lock);
Jens Axboe3d442232008-06-26 11:21:34 +0200490}
491
492void ipi_call_lock_irq(void)
493{
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100494 spin_lock_irq(&call_function.lock);
Jens Axboe3d442232008-06-26 11:21:34 +0200495}
496
497void ipi_call_unlock_irq(void)
498{
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100499 spin_unlock_irq(&call_function.lock);
Jens Axboe3d442232008-06-26 11:21:34 +0200500}