Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Generic helpers for smp ipi calls |
| 3 | * |
| 4 | * (C) Jens Axboe <jens.axboe@oracle.com> 2008 |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 5 | */ |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 6 | #include <linux/rcupdate.h> |
Linus Torvalds | 59190f4 | 2008-07-15 14:02:33 -0700 | [diff] [blame] | 7 | #include <linux/rculist.h> |
Ingo Molnar | 641cd4c | 2009-03-13 10:47:34 +0100 | [diff] [blame] | 8 | #include <linux/kernel.h> |
Paul Gortmaker | 9984de1 | 2011-05-23 14:51:41 -0400 | [diff] [blame] | 9 | #include <linux/export.h> |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 10 | #include <linux/percpu.h> |
| 11 | #include <linux/init.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 12 | #include <linux/gfp.h> |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 13 | #include <linux/smp.h> |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 14 | #include <linux/cpu.h> |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 15 | |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 16 | #include "smpboot.h" |
| 17 | |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 18 | enum { |
Peter Zijlstra | 6e27563 | 2009-02-25 13:59:48 +0100 | [diff] [blame] | 19 | CSD_FLAG_LOCK = 0x01, |
Jens Axboe | c84a83e | 2013-05-17 09:58:43 +0200 | [diff] [blame] | 20 | CSD_FLAG_WAIT = 0x02, |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 21 | }; |
| 22 | |
| 23 | struct call_function_data { |
Shaohua Li | 9a46ad6 | 2013-02-21 16:43:03 -0800 | [diff] [blame] | 24 | struct call_single_data __percpu *csd; |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 25 | cpumask_var_t cpumask; |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 26 | }; |
| 27 | |
Milton Miller | e03bcb6 | 2010-01-18 13:00:51 +1100 | [diff] [blame] | 28 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_function_data, cfd_data); |
| 29 | |
Christoph Hellwig | 6897fc2 | 2014-01-30 15:45:47 -0800 | [diff] [blame] | 30 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct llist_head, call_single_queue); |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 31 | |
| 32 | static int |
| 33 | hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu) |
| 34 | { |
| 35 | long cpu = (long)hcpu; |
| 36 | struct call_function_data *cfd = &per_cpu(cfd_data, cpu); |
| 37 | |
| 38 | switch (action) { |
| 39 | case CPU_UP_PREPARE: |
| 40 | case CPU_UP_PREPARE_FROZEN: |
Yinghai Lu | eaa9584 | 2009-06-06 14:51:36 -0700 | [diff] [blame] | 41 | if (!zalloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL, |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 42 | cpu_to_node(cpu))) |
Akinobu Mita | 80b5184 | 2010-05-26 14:43:32 -0700 | [diff] [blame] | 43 | return notifier_from_errno(-ENOMEM); |
Shaohua Li | 9a46ad6 | 2013-02-21 16:43:03 -0800 | [diff] [blame] | 44 | cfd->csd = alloc_percpu(struct call_single_data); |
| 45 | if (!cfd->csd) { |
| 46 | free_cpumask_var(cfd->cpumask); |
| 47 | return notifier_from_errno(-ENOMEM); |
| 48 | } |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 49 | break; |
| 50 | |
Xiao Guangrong | 69dd647 | 2009-08-06 15:07:29 -0700 | [diff] [blame] | 51 | #ifdef CONFIG_HOTPLUG_CPU |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 52 | case CPU_UP_CANCELED: |
| 53 | case CPU_UP_CANCELED_FROZEN: |
| 54 | |
| 55 | case CPU_DEAD: |
| 56 | case CPU_DEAD_FROZEN: |
| 57 | free_cpumask_var(cfd->cpumask); |
Shaohua Li | 9a46ad6 | 2013-02-21 16:43:03 -0800 | [diff] [blame] | 58 | free_percpu(cfd->csd); |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 59 | break; |
| 60 | #endif |
| 61 | }; |
| 62 | |
| 63 | return NOTIFY_OK; |
| 64 | } |
| 65 | |
Paul Gortmaker | 0db0628 | 2013-06-19 14:53:51 -0400 | [diff] [blame] | 66 | static struct notifier_block hotplug_cfd_notifier = { |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 67 | .notifier_call = hotplug_cfd, |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 68 | }; |
| 69 | |
Takao Indoh | d8ad7d1 | 2011-03-29 12:35:04 -0400 | [diff] [blame] | 70 | void __init call_function_init(void) |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 71 | { |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 72 | void *cpu = (void *)(long)smp_processor_id(); |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 73 | int i; |
| 74 | |
Christoph Hellwig | 6897fc2 | 2014-01-30 15:45:47 -0800 | [diff] [blame] | 75 | for_each_possible_cpu(i) |
| 76 | init_llist_head(&per_cpu(call_single_queue, i)); |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 77 | |
| 78 | hotplug_cfd(&hotplug_cfd_notifier, CPU_UP_PREPARE, cpu); |
| 79 | register_cpu_notifier(&hotplug_cfd_notifier); |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 80 | } |
| 81 | |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 82 | /* |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 83 | * csd_lock/csd_unlock used to serialize access to per-cpu csd resources |
| 84 | * |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 85 | * For non-synchronous ipi calls the csd can still be in use by the |
| 86 | * previous function call. For multi-cpu calls its even more interesting |
| 87 | * as we'll have to ensure no other cpu is observing our csd. |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 88 | */ |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 89 | static void csd_lock_wait(struct call_single_data *csd) |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 90 | { |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 91 | while (csd->flags & CSD_FLAG_LOCK) |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 92 | cpu_relax(); |
Peter Zijlstra | 6e27563 | 2009-02-25 13:59:48 +0100 | [diff] [blame] | 93 | } |
| 94 | |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 95 | static void csd_lock(struct call_single_data *csd) |
Peter Zijlstra | 6e27563 | 2009-02-25 13:59:48 +0100 | [diff] [blame] | 96 | { |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 97 | csd_lock_wait(csd); |
| 98 | csd->flags |= CSD_FLAG_LOCK; |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 99 | |
| 100 | /* |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 101 | * prevent CPU from reordering the above assignment |
| 102 | * to ->flags with any subsequent assignments to other |
| 103 | * fields of the specified call_single_data structure: |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 104 | */ |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 105 | smp_mb(); |
| 106 | } |
| 107 | |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 108 | static void csd_unlock(struct call_single_data *csd) |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 109 | { |
Jens Axboe | c84a83e | 2013-05-17 09:58:43 +0200 | [diff] [blame] | 110 | WARN_ON((csd->flags & CSD_FLAG_WAIT) && !(csd->flags & CSD_FLAG_LOCK)); |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 111 | |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 112 | /* |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 113 | * ensure we're all done before releasing data: |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 114 | */ |
| 115 | smp_mb(); |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 116 | |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 117 | csd->flags &= ~CSD_FLAG_LOCK; |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 118 | } |
| 119 | |
| 120 | /* |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 121 | * Insert a previously allocated call_single_data element |
| 122 | * for execution on the given CPU. data must already have |
| 123 | * ->func, ->info, and ->flags set. |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 124 | */ |
Christoph Hellwig | ca5ecd6 | 2013-11-14 14:32:10 -0800 | [diff] [blame] | 125 | static void generic_exec_single(int cpu, struct call_single_data *csd, int wait) |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 126 | { |
Jens Axboe | c84a83e | 2013-05-17 09:58:43 +0200 | [diff] [blame] | 127 | if (wait) |
| 128 | csd->flags |= CSD_FLAG_WAIT; |
| 129 | |
Suresh Siddha | 561920a0 | 2008-10-30 18:28:41 +0100 | [diff] [blame] | 130 | /* |
Nick Piggin | 15d0d3b | 2009-02-25 06:22:45 +0100 | [diff] [blame] | 131 | * The list addition should be visible before sending the IPI |
| 132 | * handler locks the list to pull the entry off it because of |
| 133 | * normal cache coherency rules implied by spinlocks. |
| 134 | * |
| 135 | * If IPIs can go out of order to the cache coherency protocol |
| 136 | * in an architecture, sufficient synchronisation should be added |
| 137 | * to arch code to make it appear to obey cache coherency WRT |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 138 | * locking and barrier primitives. Generic code isn't really |
| 139 | * equipped to do the right thing... |
Suresh Siddha | 561920a0 | 2008-10-30 18:28:41 +0100 | [diff] [blame] | 140 | */ |
Christoph Hellwig | 6897fc2 | 2014-01-30 15:45:47 -0800 | [diff] [blame] | 141 | if (llist_add(&csd->llist, &per_cpu(call_single_queue, cpu))) |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 142 | arch_send_call_function_single_ipi(cpu); |
| 143 | |
| 144 | if (wait) |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 145 | csd_lock_wait(csd); |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 146 | } |
| 147 | |
| 148 | /* |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 149 | * Invoked by arch to handle an IPI for call function single. Must be |
| 150 | * called from the arch with interrupts disabled. |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 151 | */ |
| 152 | void generic_smp_call_function_single_interrupt(void) |
| 153 | { |
Jan Kara | 5fd7759 | 2014-02-24 16:39:55 +0100 | [diff] [blame] | 154 | struct llist_node *entry; |
| 155 | struct call_single_data *csd, *csd_next; |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 156 | |
Suresh Siddha | 269c861 | 2009-08-19 18:05:35 -0700 | [diff] [blame] | 157 | /* |
| 158 | * Shouldn't receive this interrupt on a cpu that is not yet online. |
| 159 | */ |
| 160 | WARN_ON_ONCE(!cpu_online(smp_processor_id())); |
| 161 | |
Christoph Hellwig | 6897fc2 | 2014-01-30 15:45:47 -0800 | [diff] [blame] | 162 | entry = llist_del_all(&__get_cpu_var(call_single_queue)); |
| 163 | entry = llist_reverse_order(entry); |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 164 | |
Jan Kara | 5fd7759 | 2014-02-24 16:39:55 +0100 | [diff] [blame] | 165 | llist_for_each_entry_safe(csd, csd_next, entry, llist) { |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 166 | csd->func(csd->info); |
Xie XiuQi | 4659196 | 2013-07-30 11:06:09 +0800 | [diff] [blame] | 167 | csd_unlock(csd); |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 168 | } |
| 169 | } |
| 170 | |
Milton Miller | e03bcb6 | 2010-01-18 13:00:51 +1100 | [diff] [blame] | 171 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_single_data, csd_data); |
Steven Rostedt | d7240b9 | 2009-01-29 10:08:01 -0500 | [diff] [blame] | 172 | |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 173 | /* |
| 174 | * smp_call_function_single - Run a function on a specific CPU |
| 175 | * @func: The function to run. This must be fast and non-blocking. |
| 176 | * @info: An arbitrary pointer to pass to the function. |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 177 | * @wait: If true, wait until function has completed on other CPUs. |
| 178 | * |
Sheng Yang | 72f279b | 2009-10-22 19:19:34 +0800 | [diff] [blame] | 179 | * Returns 0 on success, else a negative status code. |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 180 | */ |
David Howells | 3a5f65d | 2010-10-27 17:28:36 +0100 | [diff] [blame] | 181 | int smp_call_function_single(int cpu, smp_call_func_t func, void *info, |
Jens Axboe | 8691e5a | 2008-06-06 11:18:06 +0200 | [diff] [blame] | 182 | int wait) |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 183 | { |
Peter Zijlstra | 8969a5e | 2009-02-25 13:59:47 +0100 | [diff] [blame] | 184 | struct call_single_data d = { |
| 185 | .flags = 0, |
| 186 | }; |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 187 | unsigned long flags; |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 188 | int this_cpu; |
H. Peter Anvin | f73be6d | 2008-08-25 17:07:14 -0700 | [diff] [blame] | 189 | int err = 0; |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 190 | |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 191 | /* |
| 192 | * prevent preemption and reschedule on another processor, |
| 193 | * as well as CPU removal |
| 194 | */ |
| 195 | this_cpu = get_cpu(); |
| 196 | |
Suresh Siddha | 269c861 | 2009-08-19 18:05:35 -0700 | [diff] [blame] | 197 | /* |
| 198 | * Can deadlock when called with interrupts disabled. |
| 199 | * We allow cpu's that are not yet online though, as no one else can |
| 200 | * send smp call function interrupt to this cpu and as such deadlocks |
| 201 | * can't happen. |
| 202 | */ |
| 203 | WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled() |
| 204 | && !oops_in_progress); |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 205 | |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 206 | if (cpu == this_cpu) { |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 207 | local_irq_save(flags); |
| 208 | func(info); |
| 209 | local_irq_restore(flags); |
H. Peter Anvin | f73be6d | 2008-08-25 17:07:14 -0700 | [diff] [blame] | 210 | } else { |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 211 | if ((unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) { |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 212 | struct call_single_data *csd = &d; |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 213 | |
| 214 | if (!wait) |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 215 | csd = &__get_cpu_var(csd_data); |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 216 | |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 217 | csd_lock(csd); |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 218 | |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 219 | csd->func = func; |
| 220 | csd->info = info; |
| 221 | generic_exec_single(cpu, csd, wait); |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 222 | } else { |
| 223 | err = -ENXIO; /* CPU not online */ |
| 224 | } |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 225 | } |
| 226 | |
| 227 | put_cpu(); |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 228 | |
H. Peter Anvin | f73be6d | 2008-08-25 17:07:14 -0700 | [diff] [blame] | 229 | return err; |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 230 | } |
| 231 | EXPORT_SYMBOL(smp_call_function_single); |
| 232 | |
Rusty Russell | 2ea6dec | 2009-11-17 14:27:27 -0800 | [diff] [blame] | 233 | /* |
| 234 | * smp_call_function_any - Run a function on any of the given cpus |
| 235 | * @mask: The mask of cpus it can run on. |
| 236 | * @func: The function to run. This must be fast and non-blocking. |
| 237 | * @info: An arbitrary pointer to pass to the function. |
| 238 | * @wait: If true, wait until function has completed. |
| 239 | * |
| 240 | * Returns 0 on success, else a negative status code (if no cpus were online). |
Rusty Russell | 2ea6dec | 2009-11-17 14:27:27 -0800 | [diff] [blame] | 241 | * |
| 242 | * Selection preference: |
| 243 | * 1) current cpu if in @mask |
| 244 | * 2) any cpu of current node if in @mask |
| 245 | * 3) any other online cpu in @mask |
| 246 | */ |
| 247 | int smp_call_function_any(const struct cpumask *mask, |
David Howells | 3a5f65d | 2010-10-27 17:28:36 +0100 | [diff] [blame] | 248 | smp_call_func_t func, void *info, int wait) |
Rusty Russell | 2ea6dec | 2009-11-17 14:27:27 -0800 | [diff] [blame] | 249 | { |
| 250 | unsigned int cpu; |
| 251 | const struct cpumask *nodemask; |
| 252 | int ret; |
| 253 | |
| 254 | /* Try for same CPU (cheapest) */ |
| 255 | cpu = get_cpu(); |
| 256 | if (cpumask_test_cpu(cpu, mask)) |
| 257 | goto call; |
| 258 | |
| 259 | /* Try for same node. */ |
David John | af2422c | 2010-01-15 17:01:23 -0800 | [diff] [blame] | 260 | nodemask = cpumask_of_node(cpu_to_node(cpu)); |
Rusty Russell | 2ea6dec | 2009-11-17 14:27:27 -0800 | [diff] [blame] | 261 | for (cpu = cpumask_first_and(nodemask, mask); cpu < nr_cpu_ids; |
| 262 | cpu = cpumask_next_and(cpu, nodemask, mask)) { |
| 263 | if (cpu_online(cpu)) |
| 264 | goto call; |
| 265 | } |
| 266 | |
| 267 | /* Any online will do: smp_call_function_single handles nr_cpu_ids. */ |
| 268 | cpu = cpumask_any_and(mask, cpu_online_mask); |
| 269 | call: |
| 270 | ret = smp_call_function_single(cpu, func, info, wait); |
| 271 | put_cpu(); |
| 272 | return ret; |
| 273 | } |
| 274 | EXPORT_SYMBOL_GPL(smp_call_function_any); |
| 275 | |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 276 | /** |
Heiko Carstens | 27c379f | 2010-09-10 13:47:29 +0200 | [diff] [blame] | 277 | * __smp_call_function_single(): Run a function on a specific CPU |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 278 | * @cpu: The CPU to run on. |
Jan Kara | 08eed44 | 2014-02-24 16:39:57 +0100 | [diff] [blame^] | 279 | * @csd: Pre-allocated and setup data structure |
Heiko Carstens | 27c379f | 2010-09-10 13:47:29 +0200 | [diff] [blame] | 280 | * @wait: If true, wait until function has completed on specified CPU. |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 281 | * |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 282 | * Like smp_call_function_single(), but allow caller to pass in a |
| 283 | * pre-allocated data structure. Useful for embedding @data inside |
| 284 | * other structures, for instance. |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 285 | */ |
Jan Kara | 08eed44 | 2014-02-24 16:39:57 +0100 | [diff] [blame^] | 286 | int __smp_call_function_single(int cpu, struct call_single_data *csd, int wait) |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 287 | { |
Heiko Carstens | 27c379f | 2010-09-10 13:47:29 +0200 | [diff] [blame] | 288 | unsigned int this_cpu; |
| 289 | unsigned long flags; |
Jan Kara | 08eed44 | 2014-02-24 16:39:57 +0100 | [diff] [blame^] | 290 | int err = 0; |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 291 | |
Heiko Carstens | 27c379f | 2010-09-10 13:47:29 +0200 | [diff] [blame] | 292 | this_cpu = get_cpu(); |
Suresh Siddha | 269c861 | 2009-08-19 18:05:35 -0700 | [diff] [blame] | 293 | /* |
| 294 | * Can deadlock when called with interrupts disabled. |
| 295 | * We allow cpu's that are not yet online though, as no one else can |
| 296 | * send smp call function interrupt to this cpu and as such deadlocks |
| 297 | * can't happen. |
| 298 | */ |
| 299 | WARN_ON_ONCE(cpu_online(smp_processor_id()) && wait && irqs_disabled() |
| 300 | && !oops_in_progress); |
Peter Zijlstra | 6e27563 | 2009-02-25 13:59:48 +0100 | [diff] [blame] | 301 | |
Heiko Carstens | 27c379f | 2010-09-10 13:47:29 +0200 | [diff] [blame] | 302 | if (cpu == this_cpu) { |
| 303 | local_irq_save(flags); |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 304 | csd->func(csd->info); |
Heiko Carstens | 27c379f | 2010-09-10 13:47:29 +0200 | [diff] [blame] | 305 | local_irq_restore(flags); |
Jan Kara | 08eed44 | 2014-02-24 16:39:57 +0100 | [diff] [blame^] | 306 | } else if ((unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) { |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 307 | csd_lock(csd); |
| 308 | generic_exec_single(cpu, csd, wait); |
Jan Kara | 08eed44 | 2014-02-24 16:39:57 +0100 | [diff] [blame^] | 309 | } else { |
| 310 | err = -ENXIO; /* CPU not online */ |
Heiko Carstens | 27c379f | 2010-09-10 13:47:29 +0200 | [diff] [blame] | 311 | } |
| 312 | put_cpu(); |
Jan Kara | 08eed44 | 2014-02-24 16:39:57 +0100 | [diff] [blame^] | 313 | return err; |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 314 | } |
Jens Axboe | e3daab6 | 2013-10-25 11:45:35 +0100 | [diff] [blame] | 315 | EXPORT_SYMBOL_GPL(__smp_call_function_single); |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 316 | |
| 317 | /** |
Rusty Russell | 54b11e6 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 318 | * smp_call_function_many(): Run a function on a set of other CPUs. |
| 319 | * @mask: The set of cpus to run on (only runs on online subset). |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 320 | * @func: The function to run. This must be fast and non-blocking. |
| 321 | * @info: An arbitrary pointer to pass to the function. |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 322 | * @wait: If true, wait (atomically) until function has completed |
| 323 | * on other CPUs. |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 324 | * |
Sheng Yang | 72f279b | 2009-10-22 19:19:34 +0800 | [diff] [blame] | 325 | * If @wait is true, then returns once @func has returned. |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 326 | * |
| 327 | * You must not call this function with disabled interrupts or from a |
| 328 | * hardware interrupt handler or from a bottom half handler. Preemption |
| 329 | * must be disabled when calling this function. |
| 330 | */ |
Rusty Russell | 54b11e6 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 331 | void smp_call_function_many(const struct cpumask *mask, |
David Howells | 3a5f65d | 2010-10-27 17:28:36 +0100 | [diff] [blame] | 332 | smp_call_func_t func, void *info, bool wait) |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 333 | { |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 334 | struct call_function_data *cfd; |
Shaohua Li | 9a46ad6 | 2013-02-21 16:43:03 -0800 | [diff] [blame] | 335 | int cpu, next_cpu, this_cpu = smp_processor_id(); |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 336 | |
Suresh Siddha | 269c861 | 2009-08-19 18:05:35 -0700 | [diff] [blame] | 337 | /* |
| 338 | * Can deadlock when called with interrupts disabled. |
| 339 | * We allow cpu's that are not yet online though, as no one else can |
| 340 | * send smp call function interrupt to this cpu and as such deadlocks |
| 341 | * can't happen. |
| 342 | */ |
| 343 | WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled() |
Tejun Heo | bd924e8 | 2011-01-20 12:07:13 +0100 | [diff] [blame] | 344 | && !oops_in_progress && !early_boot_irqs_disabled); |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 345 | |
Milton Miller | 723aae2 | 2011-03-15 13:27:17 -0600 | [diff] [blame] | 346 | /* Try to fastpath. So, what's a CPU they want? Ignoring this one. */ |
Rusty Russell | 54b11e6 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 347 | cpu = cpumask_first_and(mask, cpu_online_mask); |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 348 | if (cpu == this_cpu) |
Rusty Russell | 54b11e6 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 349 | cpu = cpumask_next_and(cpu, mask, cpu_online_mask); |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 350 | |
Rusty Russell | 54b11e6 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 351 | /* No online cpus? We're done. */ |
| 352 | if (cpu >= nr_cpu_ids) |
| 353 | return; |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 354 | |
Rusty Russell | 54b11e6 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 355 | /* Do we have another CPU which isn't us? */ |
| 356 | next_cpu = cpumask_next_and(cpu, mask, cpu_online_mask); |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 357 | if (next_cpu == this_cpu) |
Rusty Russell | 54b11e6 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 358 | next_cpu = cpumask_next_and(next_cpu, mask, cpu_online_mask); |
| 359 | |
| 360 | /* Fastpath: do that cpu by itself. */ |
| 361 | if (next_cpu >= nr_cpu_ids) { |
| 362 | smp_call_function_single(cpu, func, info, wait); |
| 363 | return; |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 364 | } |
| 365 | |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 366 | cfd = &__get_cpu_var(cfd_data); |
Milton Miller | 45a5791 | 2011-03-15 13:27:16 -0600 | [diff] [blame] | 367 | |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 368 | cpumask_and(cfd->cpumask, mask, cpu_online_mask); |
| 369 | cpumask_clear_cpu(this_cpu, cfd->cpumask); |
Milton Miller | 723aae2 | 2011-03-15 13:27:17 -0600 | [diff] [blame] | 370 | |
| 371 | /* Some callers race with other cpus changing the passed mask */ |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 372 | if (unlikely(!cpumask_weight(cfd->cpumask))) |
Milton Miller | 723aae2 | 2011-03-15 13:27:17 -0600 | [diff] [blame] | 373 | return; |
Anton Blanchard | 6dc1989 | 2011-01-20 14:44:33 -0800 | [diff] [blame] | 374 | |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 375 | for_each_cpu(cpu, cfd->cpumask) { |
| 376 | struct call_single_data *csd = per_cpu_ptr(cfd->csd, cpu); |
Shaohua Li | 9a46ad6 | 2013-02-21 16:43:03 -0800 | [diff] [blame] | 377 | |
| 378 | csd_lock(csd); |
| 379 | csd->func = func; |
| 380 | csd->info = info; |
Christoph Hellwig | 6897fc2 | 2014-01-30 15:45:47 -0800 | [diff] [blame] | 381 | llist_add(&csd->llist, &per_cpu(call_single_queue, cpu)); |
Shaohua Li | 9a46ad6 | 2013-02-21 16:43:03 -0800 | [diff] [blame] | 382 | } |
Suresh Siddha | 561920a0 | 2008-10-30 18:28:41 +0100 | [diff] [blame] | 383 | |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 384 | /* Send a message to all CPUs in the map */ |
Roman Gushchin | 73f9455 | 2014-01-30 15:45:48 -0800 | [diff] [blame] | 385 | arch_send_call_function_ipi_mask(cfd->cpumask); |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 386 | |
Shaohua Li | 9a46ad6 | 2013-02-21 16:43:03 -0800 | [diff] [blame] | 387 | if (wait) { |
Andrew Morton | e1d12f3 | 2013-04-30 15:27:28 -0700 | [diff] [blame] | 388 | for_each_cpu(cpu, cfd->cpumask) { |
| 389 | struct call_single_data *csd; |
| 390 | |
| 391 | csd = per_cpu_ptr(cfd->csd, cpu); |
Shaohua Li | 9a46ad6 | 2013-02-21 16:43:03 -0800 | [diff] [blame] | 392 | csd_lock_wait(csd); |
| 393 | } |
| 394 | } |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 395 | } |
Rusty Russell | 54b11e6 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 396 | EXPORT_SYMBOL(smp_call_function_many); |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 397 | |
| 398 | /** |
| 399 | * smp_call_function(): Run a function on all other CPUs. |
| 400 | * @func: The function to run. This must be fast and non-blocking. |
| 401 | * @info: An arbitrary pointer to pass to the function. |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 402 | * @wait: If true, wait (atomically) until function has completed |
| 403 | * on other CPUs. |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 404 | * |
Rusty Russell | 54b11e6 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 405 | * Returns 0. |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 406 | * |
| 407 | * If @wait is true, then returns once @func has returned; otherwise |
Sheng Yang | 72f279b | 2009-10-22 19:19:34 +0800 | [diff] [blame] | 408 | * it returns just before the target cpu calls @func. |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 409 | * |
| 410 | * You must not call this function with disabled interrupts or from a |
| 411 | * hardware interrupt handler or from a bottom half handler. |
| 412 | */ |
David Howells | 3a5f65d | 2010-10-27 17:28:36 +0100 | [diff] [blame] | 413 | int smp_call_function(smp_call_func_t func, void *info, int wait) |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 414 | { |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 415 | preempt_disable(); |
Rusty Russell | 54b11e6 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 416 | smp_call_function_many(cpu_online_mask, func, info, wait); |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 417 | preempt_enable(); |
Ingo Molnar | 0b13fda | 2009-02-25 16:52:11 +0100 | [diff] [blame] | 418 | |
Rusty Russell | 54b11e6 | 2008-12-30 09:05:16 +1030 | [diff] [blame] | 419 | return 0; |
Jens Axboe | 3d44223 | 2008-06-26 11:21:34 +0200 | [diff] [blame] | 420 | } |
| 421 | EXPORT_SYMBOL(smp_call_function); |
Amerigo Wang | 351f8f8 | 2011-01-12 16:59:39 -0800 | [diff] [blame] | 422 | |
Amerigo Wang | 34db18a0 | 2011-03-22 16:34:06 -0700 | [diff] [blame] | 423 | /* Setup configured maximum number of CPUs to activate */ |
| 424 | unsigned int setup_max_cpus = NR_CPUS; |
| 425 | EXPORT_SYMBOL(setup_max_cpus); |
| 426 | |
| 427 | |
| 428 | /* |
| 429 | * Setup routine for controlling SMP activation |
| 430 | * |
| 431 | * Command-line option of "nosmp" or "maxcpus=0" will disable SMP |
| 432 | * activation entirely (the MPS table probe still happens, though). |
| 433 | * |
| 434 | * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer |
| 435 | * greater than 0, limits the maximum number of CPUs activated in |
| 436 | * SMP mode to <NUM>. |
| 437 | */ |
| 438 | |
| 439 | void __weak arch_disable_smp_support(void) { } |
| 440 | |
| 441 | static int __init nosmp(char *str) |
| 442 | { |
| 443 | setup_max_cpus = 0; |
| 444 | arch_disable_smp_support(); |
| 445 | |
| 446 | return 0; |
| 447 | } |
| 448 | |
| 449 | early_param("nosmp", nosmp); |
| 450 | |
| 451 | /* this is hard limit */ |
| 452 | static int __init nrcpus(char *str) |
| 453 | { |
| 454 | int nr_cpus; |
| 455 | |
| 456 | get_option(&str, &nr_cpus); |
| 457 | if (nr_cpus > 0 && nr_cpus < nr_cpu_ids) |
| 458 | nr_cpu_ids = nr_cpus; |
| 459 | |
| 460 | return 0; |
| 461 | } |
| 462 | |
| 463 | early_param("nr_cpus", nrcpus); |
| 464 | |
| 465 | static int __init maxcpus(char *str) |
| 466 | { |
| 467 | get_option(&str, &setup_max_cpus); |
| 468 | if (setup_max_cpus == 0) |
| 469 | arch_disable_smp_support(); |
| 470 | |
| 471 | return 0; |
| 472 | } |
| 473 | |
| 474 | early_param("maxcpus", maxcpus); |
| 475 | |
| 476 | /* Setup number of possible processor ids */ |
| 477 | int nr_cpu_ids __read_mostly = NR_CPUS; |
| 478 | EXPORT_SYMBOL(nr_cpu_ids); |
| 479 | |
| 480 | /* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */ |
| 481 | void __init setup_nr_cpu_ids(void) |
| 482 | { |
| 483 | nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1; |
| 484 | } |
| 485 | |
Borislav Petkov | a17bce4 | 2013-09-30 11:56:24 +0200 | [diff] [blame] | 486 | void __weak smp_announce(void) |
| 487 | { |
| 488 | printk(KERN_INFO "Brought up %d CPUs\n", num_online_cpus()); |
| 489 | } |
| 490 | |
Amerigo Wang | 34db18a0 | 2011-03-22 16:34:06 -0700 | [diff] [blame] | 491 | /* Called by boot processor to activate the rest. */ |
| 492 | void __init smp_init(void) |
| 493 | { |
| 494 | unsigned int cpu; |
| 495 | |
Suresh Siddha | 3bb5d2e | 2012-04-20 17:08:50 -0700 | [diff] [blame] | 496 | idle_threads_init(); |
| 497 | |
Amerigo Wang | 34db18a0 | 2011-03-22 16:34:06 -0700 | [diff] [blame] | 498 | /* FIXME: This should be done in userspace --RR */ |
| 499 | for_each_present_cpu(cpu) { |
| 500 | if (num_online_cpus() >= setup_max_cpus) |
| 501 | break; |
| 502 | if (!cpu_online(cpu)) |
| 503 | cpu_up(cpu); |
| 504 | } |
| 505 | |
| 506 | /* Any cleanup work */ |
Borislav Petkov | a17bce4 | 2013-09-30 11:56:24 +0200 | [diff] [blame] | 507 | smp_announce(); |
Amerigo Wang | 34db18a0 | 2011-03-22 16:34:06 -0700 | [diff] [blame] | 508 | smp_cpus_done(setup_max_cpus); |
| 509 | } |
| 510 | |
Amerigo Wang | 351f8f8 | 2011-01-12 16:59:39 -0800 | [diff] [blame] | 511 | /* |
Tejun Heo | bd924e8 | 2011-01-20 12:07:13 +0100 | [diff] [blame] | 512 | * Call a function on all processors. May be used during early boot while |
| 513 | * early_boot_irqs_disabled is set. Use local_irq_save/restore() instead |
| 514 | * of local_irq_disable/enable(). |
Amerigo Wang | 351f8f8 | 2011-01-12 16:59:39 -0800 | [diff] [blame] | 515 | */ |
| 516 | int on_each_cpu(void (*func) (void *info), void *info, int wait) |
| 517 | { |
Tejun Heo | bd924e8 | 2011-01-20 12:07:13 +0100 | [diff] [blame] | 518 | unsigned long flags; |
Amerigo Wang | 351f8f8 | 2011-01-12 16:59:39 -0800 | [diff] [blame] | 519 | int ret = 0; |
| 520 | |
| 521 | preempt_disable(); |
| 522 | ret = smp_call_function(func, info, wait); |
Tejun Heo | bd924e8 | 2011-01-20 12:07:13 +0100 | [diff] [blame] | 523 | local_irq_save(flags); |
Amerigo Wang | 351f8f8 | 2011-01-12 16:59:39 -0800 | [diff] [blame] | 524 | func(info); |
Tejun Heo | bd924e8 | 2011-01-20 12:07:13 +0100 | [diff] [blame] | 525 | local_irq_restore(flags); |
Amerigo Wang | 351f8f8 | 2011-01-12 16:59:39 -0800 | [diff] [blame] | 526 | preempt_enable(); |
| 527 | return ret; |
| 528 | } |
| 529 | EXPORT_SYMBOL(on_each_cpu); |
Gilad Ben-Yossef | 3fc498f | 2012-03-28 14:42:43 -0700 | [diff] [blame] | 530 | |
| 531 | /** |
| 532 | * on_each_cpu_mask(): Run a function on processors specified by |
| 533 | * cpumask, which may include the local processor. |
| 534 | * @mask: The set of cpus to run on (only runs on online subset). |
| 535 | * @func: The function to run. This must be fast and non-blocking. |
| 536 | * @info: An arbitrary pointer to pass to the function. |
| 537 | * @wait: If true, wait (atomically) until function has completed |
| 538 | * on other CPUs. |
| 539 | * |
| 540 | * If @wait is true, then returns once @func has returned. |
| 541 | * |
David Daney | 202da40 | 2013-09-11 14:23:29 -0700 | [diff] [blame] | 542 | * You must not call this function with disabled interrupts or from a |
| 543 | * hardware interrupt handler or from a bottom half handler. The |
| 544 | * exception is that it may be used during early boot while |
| 545 | * early_boot_irqs_disabled is set. |
Gilad Ben-Yossef | 3fc498f | 2012-03-28 14:42:43 -0700 | [diff] [blame] | 546 | */ |
| 547 | void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func, |
| 548 | void *info, bool wait) |
| 549 | { |
| 550 | int cpu = get_cpu(); |
| 551 | |
| 552 | smp_call_function_many(mask, func, info, wait); |
| 553 | if (cpumask_test_cpu(cpu, mask)) { |
David Daney | 202da40 | 2013-09-11 14:23:29 -0700 | [diff] [blame] | 554 | unsigned long flags; |
| 555 | local_irq_save(flags); |
Gilad Ben-Yossef | 3fc498f | 2012-03-28 14:42:43 -0700 | [diff] [blame] | 556 | func(info); |
David Daney | 202da40 | 2013-09-11 14:23:29 -0700 | [diff] [blame] | 557 | local_irq_restore(flags); |
Gilad Ben-Yossef | 3fc498f | 2012-03-28 14:42:43 -0700 | [diff] [blame] | 558 | } |
| 559 | put_cpu(); |
| 560 | } |
| 561 | EXPORT_SYMBOL(on_each_cpu_mask); |
Gilad Ben-Yossef | b3a7e98 | 2012-03-28 14:42:43 -0700 | [diff] [blame] | 562 | |
| 563 | /* |
| 564 | * on_each_cpu_cond(): Call a function on each processor for which |
| 565 | * the supplied function cond_func returns true, optionally waiting |
| 566 | * for all the required CPUs to finish. This may include the local |
| 567 | * processor. |
| 568 | * @cond_func: A callback function that is passed a cpu id and |
| 569 | * the the info parameter. The function is called |
| 570 | * with preemption disabled. The function should |
| 571 | * return a blooean value indicating whether to IPI |
| 572 | * the specified CPU. |
| 573 | * @func: The function to run on all applicable CPUs. |
| 574 | * This must be fast and non-blocking. |
| 575 | * @info: An arbitrary pointer to pass to both functions. |
| 576 | * @wait: If true, wait (atomically) until function has |
| 577 | * completed on other CPUs. |
| 578 | * @gfp_flags: GFP flags to use when allocating the cpumask |
| 579 | * used internally by the function. |
| 580 | * |
| 581 | * The function might sleep if the GFP flags indicates a non |
| 582 | * atomic allocation is allowed. |
| 583 | * |
| 584 | * Preemption is disabled to protect against CPUs going offline but not online. |
| 585 | * CPUs going online during the call will not be seen or sent an IPI. |
| 586 | * |
| 587 | * You must not call this function with disabled interrupts or |
| 588 | * from a hardware interrupt handler or from a bottom half handler. |
| 589 | */ |
| 590 | void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info), |
| 591 | smp_call_func_t func, void *info, bool wait, |
| 592 | gfp_t gfp_flags) |
| 593 | { |
| 594 | cpumask_var_t cpus; |
| 595 | int cpu, ret; |
| 596 | |
| 597 | might_sleep_if(gfp_flags & __GFP_WAIT); |
| 598 | |
| 599 | if (likely(zalloc_cpumask_var(&cpus, (gfp_flags|__GFP_NOWARN)))) { |
| 600 | preempt_disable(); |
| 601 | for_each_online_cpu(cpu) |
| 602 | if (cond_func(cpu, info)) |
| 603 | cpumask_set_cpu(cpu, cpus); |
| 604 | on_each_cpu_mask(cpus, func, info, wait); |
| 605 | preempt_enable(); |
| 606 | free_cpumask_var(cpus); |
| 607 | } else { |
| 608 | /* |
| 609 | * No free cpumask, bother. No matter, we'll |
| 610 | * just have to IPI them one by one. |
| 611 | */ |
| 612 | preempt_disable(); |
| 613 | for_each_online_cpu(cpu) |
| 614 | if (cond_func(cpu, info)) { |
| 615 | ret = smp_call_function_single(cpu, func, |
| 616 | info, wait); |
| 617 | WARN_ON_ONCE(!ret); |
| 618 | } |
| 619 | preempt_enable(); |
| 620 | } |
| 621 | } |
| 622 | EXPORT_SYMBOL(on_each_cpu_cond); |
Thomas Gleixner | f37f435 | 2012-05-07 17:59:48 +0000 | [diff] [blame] | 623 | |
| 624 | static void do_nothing(void *unused) |
| 625 | { |
| 626 | } |
| 627 | |
| 628 | /** |
| 629 | * kick_all_cpus_sync - Force all cpus out of idle |
| 630 | * |
| 631 | * Used to synchronize the update of pm_idle function pointer. It's |
| 632 | * called after the pointer is updated and returns after the dummy |
| 633 | * callback function has been executed on all cpus. The execution of |
| 634 | * the function can only happen on the remote cpus after they have |
| 635 | * left the idle function which had been called via pm_idle function |
| 636 | * pointer. So it's guaranteed that nothing uses the previous pointer |
| 637 | * anymore. |
| 638 | */ |
| 639 | void kick_all_cpus_sync(void) |
| 640 | { |
| 641 | /* Make sure the change is visible before we kick the cpus */ |
| 642 | smp_mb(); |
| 643 | smp_call_function(do_nothing, NULL, 1); |
| 644 | } |
| 645 | EXPORT_SYMBOL_GPL(kick_all_cpus_sync); |