blob: c9d1c7835c2fa150e154ae95d35e16364b8e385a [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;
Xiao Guangrong54fdade2009-09-22 16:43:39 -070032 atomic_t refs;
Ingo Molnar0b13fda2009-02-25 16:52:11 +010033 cpumask_var_t cpumask;
Jens Axboe3d442232008-06-26 11:21:34 +020034};
35
36struct call_single_queue {
Ingo Molnar0b13fda2009-02-25 16:52:11 +010037 struct list_head list;
38 spinlock_t lock;
Jens Axboe3d442232008-06-26 11:21:34 +020039};
40
Xiao Guangrong54fdade2009-09-22 16:43:39 -070041static DEFINE_PER_CPU(struct call_function_data, cfd_data);
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010042
43static int
44hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
45{
46 long cpu = (long)hcpu;
47 struct call_function_data *cfd = &per_cpu(cfd_data, cpu);
48
49 switch (action) {
50 case CPU_UP_PREPARE:
51 case CPU_UP_PREPARE_FROZEN:
Yinghai Lueaa95842009-06-06 14:51:36 -070052 if (!zalloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL,
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010053 cpu_to_node(cpu)))
54 return NOTIFY_BAD;
55 break;
56
Xiao Guangrong69dd6472009-08-06 15:07:29 -070057#ifdef CONFIG_HOTPLUG_CPU
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010058 case CPU_UP_CANCELED:
59 case CPU_UP_CANCELED_FROZEN:
60
61 case CPU_DEAD:
62 case CPU_DEAD_FROZEN:
63 free_cpumask_var(cfd->cpumask);
64 break;
65#endif
66 };
67
68 return NOTIFY_OK;
69}
70
71static struct notifier_block __cpuinitdata hotplug_cfd_notifier = {
Ingo Molnar0b13fda2009-02-25 16:52:11 +010072 .notifier_call = hotplug_cfd,
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010073};
74
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -070075static int __cpuinit init_call_single_data(void)
Jens Axboe3d442232008-06-26 11:21:34 +020076{
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010077 void *cpu = (void *)(long)smp_processor_id();
Jens Axboe3d442232008-06-26 11:21:34 +020078 int i;
79
80 for_each_possible_cpu(i) {
81 struct call_single_queue *q = &per_cpu(call_single_queue, i);
82
83 spin_lock_init(&q->lock);
84 INIT_LIST_HEAD(&q->list);
85 }
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010086
87 hotplug_cfd(&hotplug_cfd_notifier, CPU_UP_PREPARE, cpu);
88 register_cpu_notifier(&hotplug_cfd_notifier);
89
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -070090 return 0;
Jens Axboe3d442232008-06-26 11:21:34 +020091}
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -070092early_initcall(init_call_single_data);
Jens Axboe3d442232008-06-26 11:21:34 +020093
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010094/*
Peter Zijlstra8969a5e2009-02-25 13:59:47 +010095 * csd_lock/csd_unlock used to serialize access to per-cpu csd resources
96 *
Ingo Molnar0b13fda2009-02-25 16:52:11 +010097 * For non-synchronous ipi calls the csd can still be in use by the
98 * previous function call. For multi-cpu calls its even more interesting
99 * as we'll have to ensure no other cpu is observing our csd.
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100100 */
Peter Zijlstra6e275632009-02-25 13:59:48 +0100101static void csd_lock_wait(struct call_single_data *data)
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100102{
103 while (data->flags & CSD_FLAG_LOCK)
104 cpu_relax();
Peter Zijlstra6e275632009-02-25 13:59:48 +0100105}
106
107static void csd_lock(struct call_single_data *data)
108{
109 csd_lock_wait(data);
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100110 data->flags = CSD_FLAG_LOCK;
111
112 /*
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100113 * prevent CPU from reordering the above assignment
114 * to ->flags with any subsequent assignments to other
115 * fields of the specified call_single_data structure:
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100116 */
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100117 smp_mb();
118}
119
120static void csd_unlock(struct call_single_data *data)
121{
122 WARN_ON(!(data->flags & CSD_FLAG_LOCK));
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100123
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100124 /*
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100125 * ensure we're all done before releasing data:
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100126 */
127 smp_mb();
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100128
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100129 data->flags &= ~CSD_FLAG_LOCK;
Jens Axboe3d442232008-06-26 11:21:34 +0200130}
131
132/*
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100133 * Insert a previously allocated call_single_data element
134 * for execution on the given CPU. data must already have
135 * ->func, ->info, and ->flags set.
Jens Axboe3d442232008-06-26 11:21:34 +0200136 */
Peter Zijlstra6e275632009-02-25 13:59:48 +0100137static
138void generic_exec_single(int cpu, struct call_single_data *data, int wait)
Jens Axboe3d442232008-06-26 11:21:34 +0200139{
140 struct call_single_queue *dst = &per_cpu(call_single_queue, cpu);
Jens Axboe3d442232008-06-26 11:21:34 +0200141 unsigned long flags;
Peter Zijlstra6e275632009-02-25 13:59:48 +0100142 int ipi;
Jens Axboe3d442232008-06-26 11:21:34 +0200143
144 spin_lock_irqsave(&dst->lock, flags);
145 ipi = list_empty(&dst->list);
146 list_add_tail(&data->list, &dst->list);
147 spin_unlock_irqrestore(&dst->lock, flags);
148
Suresh Siddha561920a02008-10-30 18:28:41 +0100149 /*
Nick Piggin15d0d3b2009-02-25 06:22:45 +0100150 * The list addition should be visible before sending the IPI
151 * handler locks the list to pull the entry off it because of
152 * normal cache coherency rules implied by spinlocks.
153 *
154 * If IPIs can go out of order to the cache coherency protocol
155 * in an architecture, sufficient synchronisation should be added
156 * to arch code to make it appear to obey cache coherency WRT
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100157 * locking and barrier primitives. Generic code isn't really
158 * equipped to do the right thing...
Suresh Siddha561920a02008-10-30 18:28:41 +0100159 */
Jens Axboe3d442232008-06-26 11:21:34 +0200160 if (ipi)
161 arch_send_call_function_single_ipi(cpu);
162
163 if (wait)
Peter Zijlstra6e275632009-02-25 13:59:48 +0100164 csd_lock_wait(data);
Jens Axboe3d442232008-06-26 11:21:34 +0200165}
166
167/*
168 * Invoked by arch to handle an IPI for call function. Must be called with
169 * interrupts disabled.
170 */
171void generic_smp_call_function_interrupt(void)
172{
173 struct call_function_data *data;
174 int cpu = get_cpu();
175
176 /*
Suresh Siddha269c8612009-08-19 18:05:35 -0700177 * Shouldn't receive this interrupt on a cpu that is not yet online.
178 */
179 WARN_ON_ONCE(!cpu_online(cpu));
180
181 /*
Nick Piggin15d0d3b2009-02-25 06:22:45 +0100182 * Ensure entry is visible on call_function_queue after we have
183 * entered the IPI. See comment in smp_call_function_many.
184 * If we don't have this, then we may miss an entry on the list
185 * and never get another IPI to process it.
186 */
187 smp_mb();
188
189 /*
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100190 * It's ok to use list_for_each_rcu() here even though we may
191 * delete 'pos', since list_del_rcu() doesn't clear ->next
Jens Axboe3d442232008-06-26 11:21:34 +0200192 */
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100193 list_for_each_entry_rcu(data, &call_function.queue, csd.list) {
Jens Axboe3d442232008-06-26 11:21:34 +0200194 int refs;
195
Xiao Guangrong54fdade2009-09-22 16:43:39 -0700196 if (!cpumask_test_and_clear_cpu(cpu, data->cpumask))
Jens Axboe3d442232008-06-26 11:21:34 +0200197 continue;
198
199 data->csd.func(data->csd.info);
200
Xiao Guangrong54fdade2009-09-22 16:43:39 -0700201 refs = atomic_dec_return(&data->refs);
202 WARN_ON(refs < 0);
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100203 if (!refs) {
204 spin_lock(&call_function.lock);
205 list_del_rcu(&data->csd.list);
206 spin_unlock(&call_function.lock);
207 }
Jens Axboe3d442232008-06-26 11:21:34 +0200208
209 if (refs)
210 continue;
211
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100212 csd_unlock(&data->csd);
Jens Axboe3d442232008-06-26 11:21:34 +0200213 }
Jens Axboe3d442232008-06-26 11:21:34 +0200214
215 put_cpu();
216}
217
218/*
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100219 * Invoked by arch to handle an IPI for call function single. Must be
220 * called from the arch with interrupts disabled.
Jens Axboe3d442232008-06-26 11:21:34 +0200221 */
222void generic_smp_call_function_single_interrupt(void)
223{
224 struct call_single_queue *q = &__get_cpu_var(call_single_queue);
Nick Piggin15d0d3b2009-02-25 06:22:45 +0100225 unsigned int data_flags;
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100226 LIST_HEAD(list);
Jens Axboe3d442232008-06-26 11:21:34 +0200227
Suresh Siddha269c8612009-08-19 18:05:35 -0700228 /*
229 * Shouldn't receive this interrupt on a cpu that is not yet online.
230 */
231 WARN_ON_ONCE(!cpu_online(smp_processor_id()));
232
Nick Piggin15d0d3b2009-02-25 06:22:45 +0100233 spin_lock(&q->lock);
234 list_replace_init(&q->list, &list);
235 spin_unlock(&q->lock);
Jens Axboe3d442232008-06-26 11:21:34 +0200236
Nick Piggin15d0d3b2009-02-25 06:22:45 +0100237 while (!list_empty(&list)) {
238 struct call_single_data *data;
Jens Axboe3d442232008-06-26 11:21:34 +0200239
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100240 data = list_entry(list.next, struct call_single_data, list);
Nick Piggin15d0d3b2009-02-25 06:22:45 +0100241 list_del(&data->list);
Jens Axboe3d442232008-06-26 11:21:34 +0200242
Jens Axboe3d442232008-06-26 11:21:34 +0200243 /*
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100244 * 'data' can be invalid after this call if flags == 0
245 * (when called through generic_exec_single()),
246 * so save them away before making the call:
Jens Axboe3d442232008-06-26 11:21:34 +0200247 */
Nick Piggin15d0d3b2009-02-25 06:22:45 +0100248 data_flags = data->flags;
249
250 data->func(data->info);
251
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100252 /*
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100253 * Unlocked CSDs are valid through generic_exec_single():
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100254 */
255 if (data_flags & CSD_FLAG_LOCK)
256 csd_unlock(data);
Jens Axboe3d442232008-06-26 11:21:34 +0200257 }
258}
259
Steven Rostedtd7240b92009-01-29 10:08:01 -0500260static DEFINE_PER_CPU(struct call_single_data, csd_data);
261
Jens Axboe3d442232008-06-26 11:21:34 +0200262/*
263 * smp_call_function_single - Run a function on a specific CPU
264 * @func: The function to run. This must be fast and non-blocking.
265 * @info: An arbitrary pointer to pass to the function.
Jens Axboe3d442232008-06-26 11:21:34 +0200266 * @wait: If true, wait until function has completed on other CPUs.
267 *
268 * Returns 0 on success, else a negative status code. Note that @wait
269 * will be implicitly turned on in case of allocation failures, since
270 * we fall back to on-stack allocation.
271 */
272int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
Jens Axboe8691e5a2008-06-06 11:18:06 +0200273 int wait)
Jens Axboe3d442232008-06-26 11:21:34 +0200274{
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100275 struct call_single_data d = {
276 .flags = 0,
277 };
Jens Axboe3d442232008-06-26 11:21:34 +0200278 unsigned long flags;
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100279 int this_cpu;
H. Peter Anvinf73be6d2008-08-25 17:07:14 -0700280 int err = 0;
Jens Axboe3d442232008-06-26 11:21:34 +0200281
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100282 /*
283 * prevent preemption and reschedule on another processor,
284 * as well as CPU removal
285 */
286 this_cpu = get_cpu();
287
Suresh Siddha269c8612009-08-19 18:05:35 -0700288 /*
289 * Can deadlock when called with interrupts disabled.
290 * We allow cpu's that are not yet online though, as no one else can
291 * send smp call function interrupt to this cpu and as such deadlocks
292 * can't happen.
293 */
294 WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
295 && !oops_in_progress);
Jens Axboe3d442232008-06-26 11:21:34 +0200296
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100297 if (cpu == this_cpu) {
Jens Axboe3d442232008-06-26 11:21:34 +0200298 local_irq_save(flags);
299 func(info);
300 local_irq_restore(flags);
H. Peter Anvinf73be6d2008-08-25 17:07:14 -0700301 } else {
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100302 if ((unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) {
303 struct call_single_data *data = &d;
304
305 if (!wait)
306 data = &__get_cpu_var(csd_data);
307
308 csd_lock(data);
309
310 data->func = func;
311 data->info = info;
312 generic_exec_single(cpu, data, wait);
313 } else {
314 err = -ENXIO; /* CPU not online */
315 }
Jens Axboe3d442232008-06-26 11:21:34 +0200316 }
317
318 put_cpu();
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100319
H. Peter Anvinf73be6d2008-08-25 17:07:14 -0700320 return err;
Jens Axboe3d442232008-06-26 11:21:34 +0200321}
322EXPORT_SYMBOL(smp_call_function_single);
323
324/**
325 * __smp_call_function_single(): Run a function on another CPU
326 * @cpu: The CPU to run on.
327 * @data: Pre-allocated and setup data structure
328 *
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100329 * Like smp_call_function_single(), but allow caller to pass in a
330 * pre-allocated data structure. Useful for embedding @data inside
331 * other structures, for instance.
Jens Axboe3d442232008-06-26 11:21:34 +0200332 */
Peter Zijlstra6e275632009-02-25 13:59:48 +0100333void __smp_call_function_single(int cpu, struct call_single_data *data,
334 int wait)
Jens Axboe3d442232008-06-26 11:21:34 +0200335{
Peter Zijlstra6e275632009-02-25 13:59:48 +0100336 csd_lock(data);
Jens Axboe3d442232008-06-26 11:21:34 +0200337
Suresh Siddha269c8612009-08-19 18:05:35 -0700338 /*
339 * Can deadlock when called with interrupts disabled.
340 * We allow cpu's that are not yet online though, as no one else can
341 * send smp call function interrupt to this cpu and as such deadlocks
342 * can't happen.
343 */
344 WARN_ON_ONCE(cpu_online(smp_processor_id()) && wait && irqs_disabled()
345 && !oops_in_progress);
Peter Zijlstra6e275632009-02-25 13:59:48 +0100346
347 generic_exec_single(cpu, data, wait);
Jens Axboe3d442232008-06-26 11:21:34 +0200348}
349
350/**
Rusty Russell54b11e62008-12-30 09:05:16 +1030351 * smp_call_function_many(): Run a function on a set of other CPUs.
352 * @mask: The set of cpus to run on (only runs on online subset).
Jens Axboe3d442232008-06-26 11:21:34 +0200353 * @func: The function to run. This must be fast and non-blocking.
354 * @info: An arbitrary pointer to pass to the function.
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100355 * @wait: If true, wait (atomically) until function has completed
356 * on other CPUs.
Jens Axboe3d442232008-06-26 11:21:34 +0200357 *
Jens Axboe3d442232008-06-26 11:21:34 +0200358 * If @wait is true, then returns once @func has returned. Note that @wait
359 * will be implicitly turned on in case of allocation failures, since
360 * we fall back to on-stack allocation.
361 *
362 * You must not call this function with disabled interrupts or from a
363 * hardware interrupt handler or from a bottom half handler. Preemption
364 * must be disabled when calling this function.
365 */
Rusty Russell54b11e62008-12-30 09:05:16 +1030366void smp_call_function_many(const struct cpumask *mask,
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100367 void (*func)(void *), void *info, bool wait)
Jens Axboe3d442232008-06-26 11:21:34 +0200368{
Rusty Russell54b11e62008-12-30 09:05:16 +1030369 struct call_function_data *data;
Jens Axboe3d442232008-06-26 11:21:34 +0200370 unsigned long flags;
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100371 int cpu, next_cpu, this_cpu = smp_processor_id();
Jens Axboe3d442232008-06-26 11:21:34 +0200372
Suresh Siddha269c8612009-08-19 18:05:35 -0700373 /*
374 * Can deadlock when called with interrupts disabled.
375 * We allow cpu's that are not yet online though, as no one else can
376 * send smp call function interrupt to this cpu and as such deadlocks
377 * can't happen.
378 */
379 WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
380 && !oops_in_progress);
Jens Axboe3d442232008-06-26 11:21:34 +0200381
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100382 /* So, what's a CPU they want? Ignoring this one. */
Rusty Russell54b11e62008-12-30 09:05:16 +1030383 cpu = cpumask_first_and(mask, cpu_online_mask);
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100384 if (cpu == this_cpu)
Rusty Russell54b11e62008-12-30 09:05:16 +1030385 cpu = cpumask_next_and(cpu, mask, cpu_online_mask);
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100386
Rusty Russell54b11e62008-12-30 09:05:16 +1030387 /* No online cpus? We're done. */
388 if (cpu >= nr_cpu_ids)
389 return;
Jens Axboe3d442232008-06-26 11:21:34 +0200390
Rusty Russell54b11e62008-12-30 09:05:16 +1030391 /* Do we have another CPU which isn't us? */
392 next_cpu = cpumask_next_and(cpu, mask, cpu_online_mask);
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100393 if (next_cpu == this_cpu)
Rusty Russell54b11e62008-12-30 09:05:16 +1030394 next_cpu = cpumask_next_and(next_cpu, mask, cpu_online_mask);
395
396 /* Fastpath: do that cpu by itself. */
397 if (next_cpu >= nr_cpu_ids) {
398 smp_call_function_single(cpu, func, info, wait);
399 return;
Jens Axboe3d442232008-06-26 11:21:34 +0200400 }
401
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100402 data = &__get_cpu_var(cfd_data);
403 csd_lock(&data->csd);
Jens Axboe3d442232008-06-26 11:21:34 +0200404
Jens Axboe3d442232008-06-26 11:21:34 +0200405 data->csd.func = func;
406 data->csd.info = info;
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100407 cpumask_and(data->cpumask, mask, cpu_online_mask);
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100408 cpumask_clear_cpu(this_cpu, data->cpumask);
Xiao Guangrong54fdade2009-09-22 16:43:39 -0700409 atomic_set(&data->refs, cpumask_weight(data->cpumask));
Jens Axboe3d442232008-06-26 11:21:34 +0200410
Xiao Guangrong54fdade2009-09-22 16:43:39 -0700411 spin_lock_irqsave(&call_function.lock, flags);
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100412 /*
413 * Place entry at the _HEAD_ of the list, so that any cpu still
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100414 * observing the entry in generic_smp_call_function_interrupt()
415 * will not miss any other list entries:
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100416 */
417 list_add_rcu(&data->csd.list, &call_function.queue);
Xiao Guangrong54fdade2009-09-22 16:43:39 -0700418 spin_unlock_irqrestore(&call_function.lock, flags);
Jens Axboe3d442232008-06-26 11:21:34 +0200419
Suresh Siddha561920a02008-10-30 18:28:41 +0100420 /*
421 * Make the list addition visible before sending the ipi.
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100422 * (IPIs must obey or appear to obey normal Linux cache
423 * coherency rules -- see comment in generic_exec_single).
Suresh Siddha561920a02008-10-30 18:28:41 +0100424 */
425 smp_mb();
426
Jens Axboe3d442232008-06-26 11:21:34 +0200427 /* Send a message to all CPUs in the map */
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100428 arch_send_call_function_ipi_mask(data->cpumask);
Jens Axboe3d442232008-06-26 11:21:34 +0200429
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100430 /* Optionally wait for the CPUs to complete */
Rusty Russell54b11e62008-12-30 09:05:16 +1030431 if (wait)
Peter Zijlstra6e275632009-02-25 13:59:48 +0100432 csd_lock_wait(&data->csd);
Jens Axboe3d442232008-06-26 11:21:34 +0200433}
Rusty Russell54b11e62008-12-30 09:05:16 +1030434EXPORT_SYMBOL(smp_call_function_many);
Jens Axboe3d442232008-06-26 11:21:34 +0200435
436/**
437 * smp_call_function(): Run a function on all other CPUs.
438 * @func: The function to run. This must be fast and non-blocking.
439 * @info: An arbitrary pointer to pass to the function.
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100440 * @wait: If true, wait (atomically) until function has completed
441 * on other CPUs.
Jens Axboe3d442232008-06-26 11:21:34 +0200442 *
Rusty Russell54b11e62008-12-30 09:05:16 +1030443 * Returns 0.
Jens Axboe3d442232008-06-26 11:21:34 +0200444 *
445 * If @wait is true, then returns once @func has returned; otherwise
446 * it returns just before the target cpu calls @func. In case of allocation
447 * failure, @wait will be implicitly turned on.
448 *
449 * You must not call this function with disabled interrupts or from a
450 * hardware interrupt handler or from a bottom half handler.
451 */
Jens Axboe8691e5a2008-06-06 11:18:06 +0200452int smp_call_function(void (*func)(void *), void *info, int wait)
Jens Axboe3d442232008-06-26 11:21:34 +0200453{
Jens Axboe3d442232008-06-26 11:21:34 +0200454 preempt_disable();
Rusty Russell54b11e62008-12-30 09:05:16 +1030455 smp_call_function_many(cpu_online_mask, func, info, wait);
Jens Axboe3d442232008-06-26 11:21:34 +0200456 preempt_enable();
Ingo Molnar0b13fda2009-02-25 16:52:11 +0100457
Rusty Russell54b11e62008-12-30 09:05:16 +1030458 return 0;
Jens Axboe3d442232008-06-26 11:21:34 +0200459}
460EXPORT_SYMBOL(smp_call_function);
461
462void ipi_call_lock(void)
463{
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100464 spin_lock(&call_function.lock);
Jens Axboe3d442232008-06-26 11:21:34 +0200465}
466
467void ipi_call_unlock(void)
468{
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100469 spin_unlock(&call_function.lock);
Jens Axboe3d442232008-06-26 11:21:34 +0200470}
471
472void ipi_call_lock_irq(void)
473{
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100474 spin_lock_irq(&call_function.lock);
Jens Axboe3d442232008-06-26 11:21:34 +0200475}
476
477void ipi_call_unlock_irq(void)
478{
Peter Zijlstra8969a5e2009-02-25 13:59:47 +0100479 spin_unlock_irq(&call_function.lock);
Jens Axboe3d442232008-06-26 11:21:34 +0200480}