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kernel/smp.c
21.7 KB
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// SPDX-License-Identifier: GPL-2.0-only |
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/* * Generic helpers for smp ipi calls * * (C) Jens Axboe <jens.axboe@oracle.com> 2008 |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/irq_work.h> |
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#include <linux/rcupdate.h> |
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#include <linux/rculist.h> |
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#include <linux/kernel.h> |
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#include <linux/export.h> |
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#include <linux/percpu.h> #include <linux/init.h> |
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#include <linux/gfp.h> |
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#include <linux/smp.h> |
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#include <linux/cpu.h> |
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#include <linux/sched.h> |
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#include <linux/sched/idle.h> |
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#include <linux/hypervisor.h> |
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|
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#include "smpboot.h" |
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enum { |
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CSD_FLAG_LOCK = 0x01, |
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CSD_FLAG_SYNCHRONOUS = 0x02, |
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}; struct call_function_data { |
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call_single_data_t __percpu *csd; |
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cpumask_var_t cpumask; |
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cpumask_var_t cpumask_ipi; |
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}; |
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static DEFINE_PER_CPU_ALIGNED(struct call_function_data, cfd_data); |
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|
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static DEFINE_PER_CPU_SHARED_ALIGNED(struct llist_head, call_single_queue); |
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|
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static void flush_smp_call_function_queue(bool warn_cpu_offline); |
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int smpcfd_prepare_cpu(unsigned int cpu) |
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{ |
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struct call_function_data *cfd = &per_cpu(cfd_data, cpu); |
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if (!zalloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL, cpu_to_node(cpu))) return -ENOMEM; |
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if (!zalloc_cpumask_var_node(&cfd->cpumask_ipi, GFP_KERNEL, cpu_to_node(cpu))) { free_cpumask_var(cfd->cpumask); return -ENOMEM; } |
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cfd->csd = alloc_percpu(call_single_data_t); |
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if (!cfd->csd) { |
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free_cpumask_var(cfd->cpumask); |
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free_cpumask_var(cfd->cpumask_ipi); |
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return -ENOMEM; } return 0; |
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} |
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int smpcfd_dead_cpu(unsigned int cpu) { struct call_function_data *cfd = &per_cpu(cfd_data, cpu); free_cpumask_var(cfd->cpumask); |
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free_cpumask_var(cfd->cpumask_ipi); |
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free_percpu(cfd->csd); return 0; } int smpcfd_dying_cpu(unsigned int cpu) { /* * The IPIs for the smp-call-function callbacks queued by other * CPUs might arrive late, either due to hardware latencies or * because this CPU disabled interrupts (inside stop-machine) * before the IPIs were sent. So flush out any pending callbacks * explicitly (without waiting for the IPIs to arrive), to * ensure that the outgoing CPU doesn't go offline with work * still pending. */ flush_smp_call_function_queue(false); return 0; } |
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|
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void __init call_function_init(void) |
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{ int i; |
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for_each_possible_cpu(i) init_llist_head(&per_cpu(call_single_queue, i)); |
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|
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smpcfd_prepare_cpu(smp_processor_id()); |
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} |
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/* |
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* csd_lock/csd_unlock used to serialize access to per-cpu csd resources * |
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* For non-synchronous ipi calls the csd can still be in use by the * previous function call. For multi-cpu calls its even more interesting * as we'll have to ensure no other cpu is observing our csd. |
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*/ |
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static __always_inline void csd_lock_wait(call_single_data_t *csd) |
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{ |
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smp_cond_load_acquire(&csd->flags, !(VAL & CSD_FLAG_LOCK)); |
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} |
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static __always_inline void csd_lock(call_single_data_t *csd) |
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{ |
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csd_lock_wait(csd); csd->flags |= CSD_FLAG_LOCK; |
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/* |
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* prevent CPU from reordering the above assignment * to ->flags with any subsequent assignments to other |
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* fields of the specified call_single_data_t structure: |
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*/ |
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smp_wmb(); |
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} |
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static __always_inline void csd_unlock(call_single_data_t *csd) |
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{ |
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WARN_ON(!(csd->flags & CSD_FLAG_LOCK)); |
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|
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/* |
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* ensure we're all done before releasing data: |
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*/ |
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smp_store_release(&csd->flags, 0); |
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} |
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static DEFINE_PER_CPU_SHARED_ALIGNED(call_single_data_t, csd_data); |
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|
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/* |
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* Insert a previously allocated call_single_data_t element |
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* for execution on the given CPU. data must already have * ->func, ->info, and ->flags set. |
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*/ |
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static int generic_exec_single(int cpu, call_single_data_t *csd, |
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smp_call_func_t func, void *info) |
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{ |
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if (cpu == smp_processor_id()) { |
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unsigned long flags; /* * We can unlock early even for the synchronous on-stack case, * since we're doing this from the same CPU.. */ csd_unlock(csd); |
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local_irq_save(flags); func(info); local_irq_restore(flags); return 0; } |
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if ((unsigned)cpu >= nr_cpu_ids || !cpu_online(cpu)) { csd_unlock(csd); |
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return -ENXIO; |
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} |
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|
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csd->func = func; csd->info = info; |
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/* |
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* The list addition should be visible before sending the IPI * handler locks the list to pull the entry off it because of * normal cache coherency rules implied by spinlocks. * * If IPIs can go out of order to the cache coherency protocol * in an architecture, sufficient synchronisation should be added * to arch code to make it appear to obey cache coherency WRT |
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* locking and barrier primitives. Generic code isn't really * equipped to do the right thing... |
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*/ |
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if (llist_add(&csd->llist, &per_cpu(call_single_queue, cpu))) |
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arch_send_call_function_single_ipi(cpu); |
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return 0; |
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} |
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/** * generic_smp_call_function_single_interrupt - Execute SMP IPI callbacks * * Invoked by arch to handle an IPI for call function single. * Must be called with interrupts disabled. |
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*/ void generic_smp_call_function_single_interrupt(void) { |
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flush_smp_call_function_queue(true); } /** * flush_smp_call_function_queue - Flush pending smp-call-function callbacks * * @warn_cpu_offline: If set to 'true', warn if callbacks were queued on an * offline CPU. Skip this check if set to 'false'. * * Flush any pending smp-call-function callbacks queued on this CPU. This is * invoked by the generic IPI handler, as well as by a CPU about to go offline, * to ensure that all pending IPI callbacks are run before it goes completely * offline. * * Loop through the call_single_queue and run all the queued callbacks. * Must be called with interrupts disabled. */ static void flush_smp_call_function_queue(bool warn_cpu_offline) { struct llist_head *head; |
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struct llist_node *entry; |
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call_single_data_t *csd, *csd_next; |
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static bool warned; |
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lockdep_assert_irqs_disabled(); |
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|
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head = this_cpu_ptr(&call_single_queue); |
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entry = llist_del_all(head); |
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entry = llist_reverse_order(entry); |
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|
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/* There shouldn't be any pending callbacks on an offline CPU. */ if (unlikely(warn_cpu_offline && !cpu_online(smp_processor_id()) && !warned && !llist_empty(head))) { |
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warned = true; WARN(1, "IPI on offline CPU %d ", smp_processor_id()); /* * We don't have to use the _safe() variant here * because we are not invoking the IPI handlers yet. */ llist_for_each_entry(csd, entry, llist) pr_warn("IPI callback %pS sent to offline CPU ", csd->func); } |
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|
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llist_for_each_entry_safe(csd, csd_next, entry, llist) { |
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smp_call_func_t func = csd->func; void *info = csd->info; /* Do we wait until *after* callback? */ if (csd->flags & CSD_FLAG_SYNCHRONOUS) { func(info); csd_unlock(csd); } else { csd_unlock(csd); func(info); } |
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} |
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/* * Handle irq works queued remotely by irq_work_queue_on(). * Smp functions above are typically synchronous so they * better run first since some other CPUs may be busy waiting * for them. */ irq_work_run(); |
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} /* * smp_call_function_single - Run a function on a specific CPU * @func: The function to run. This must be fast and non-blocking. * @info: An arbitrary pointer to pass to the function. |
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* @wait: If true, wait until function has completed on other CPUs. * |
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* Returns 0 on success, else a negative status code. |
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*/ |
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int smp_call_function_single(int cpu, smp_call_func_t func, void *info, |
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int wait) |
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{ |
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call_single_data_t *csd; call_single_data_t csd_stack = { .flags = CSD_FLAG_LOCK | CSD_FLAG_SYNCHRONOUS, }; |
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int this_cpu; |
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int err; |
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|
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/* * prevent preemption and reschedule on another processor, * as well as CPU removal */ this_cpu = get_cpu(); |
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/* * Can deadlock when called with interrupts disabled. * We allow cpu's that are not yet online though, as no one else can * send smp call function interrupt to this cpu and as such deadlocks * can't happen. */ WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled() && !oops_in_progress); |
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|
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/* * When @wait we can deadlock when we interrupt between llist_add() and * arch_send_call_function_ipi*(); when !@wait we can deadlock due to * csd_lock() on because the interrupt context uses the same csd * storage. */ WARN_ON_ONCE(!in_task()); |
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csd = &csd_stack; if (!wait) { csd = this_cpu_ptr(&csd_data); csd_lock(csd); } err = generic_exec_single(cpu, csd, func, info); if (wait) csd_lock_wait(csd); |
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put_cpu(); |
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|
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return err; |
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} EXPORT_SYMBOL(smp_call_function_single); |
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/** |
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* smp_call_function_single_async(): Run an asynchronous function on a * specific CPU. |
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* @cpu: The CPU to run on. * @csd: Pre-allocated and setup data structure |
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* |
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* Like smp_call_function_single(), but the call is asynchonous and * can thus be done from contexts with disabled interrupts. * * The caller passes his own pre-allocated data structure * (ie: embedded in an object) and is responsible for synchronizing it * such that the IPIs performed on the @csd are strictly serialized. * |
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* If the function is called with one csd which has not yet been * processed by previous call to smp_call_function_single_async(), the * function will return immediately with -EBUSY showing that the csd * object is still in progress. * |
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* NOTE: Be careful, there is unfortunately no current debugging facility to * validate the correctness of this serialization. |
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*/ |
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int smp_call_function_single_async(int cpu, call_single_data_t *csd) |
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{ int err = 0; |
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|
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preempt_disable(); |
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|
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if (csd->flags & CSD_FLAG_LOCK) { err = -EBUSY; goto out; } |
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csd->flags = CSD_FLAG_LOCK; smp_wmb(); err = generic_exec_single(cpu, csd, csd->func, csd->info); |
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out: |
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preempt_enable(); |
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return err; } |
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EXPORT_SYMBOL_GPL(smp_call_function_single_async); |
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|
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/* * smp_call_function_any - Run a function on any of the given cpus * @mask: The mask of cpus it can run on. * @func: The function to run. This must be fast and non-blocking. * @info: An arbitrary pointer to pass to the function. * @wait: If true, wait until function has completed. * * Returns 0 on success, else a negative status code (if no cpus were online). |
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* * Selection preference: * 1) current cpu if in @mask * 2) any cpu of current node if in @mask * 3) any other online cpu in @mask */ int smp_call_function_any(const struct cpumask *mask, |
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smp_call_func_t func, void *info, int wait) |
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{ unsigned int cpu; const struct cpumask *nodemask; int ret; /* Try for same CPU (cheapest) */ cpu = get_cpu(); if (cpumask_test_cpu(cpu, mask)) goto call; /* Try for same node. */ |
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nodemask = cpumask_of_node(cpu_to_node(cpu)); |
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for (cpu = cpumask_first_and(nodemask, mask); cpu < nr_cpu_ids; cpu = cpumask_next_and(cpu, nodemask, mask)) { if (cpu_online(cpu)) goto call; } /* Any online will do: smp_call_function_single handles nr_cpu_ids. */ cpu = cpumask_any_and(mask, cpu_online_mask); call: ret = smp_call_function_single(cpu, func, info, wait); put_cpu(); return ret; } EXPORT_SYMBOL_GPL(smp_call_function_any); |
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static void smp_call_function_many_cond(const struct cpumask *mask, smp_call_func_t func, void *info, bool wait, smp_cond_func_t cond_func) |
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{ |
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struct call_function_data *cfd; |
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int cpu, next_cpu, this_cpu = smp_processor_id(); |
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|
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/* * Can deadlock when called with interrupts disabled. * We allow cpu's that are not yet online though, as no one else can * send smp call function interrupt to this cpu and as such deadlocks * can't happen. */ WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled() |
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&& !oops_in_progress && !early_boot_irqs_disabled); |
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|
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/* * When @wait we can deadlock when we interrupt between llist_add() and * arch_send_call_function_ipi*(); when !@wait we can deadlock due to * csd_lock() on because the interrupt context uses the same csd * storage. */ WARN_ON_ONCE(!in_task()); |
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/* Try to fastpath. So, what's a CPU they want? Ignoring this one. */ |
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cpu = cpumask_first_and(mask, cpu_online_mask); |
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if (cpu == this_cpu) |
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cpu = cpumask_next_and(cpu, mask, cpu_online_mask); |
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|
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/* No online cpus? We're done. */ if (cpu >= nr_cpu_ids) return; /* Do we have another CPU which isn't us? */ next_cpu = cpumask_next_and(cpu, mask, cpu_online_mask); |
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if (next_cpu == this_cpu) |
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next_cpu = cpumask_next_and(next_cpu, mask, cpu_online_mask); /* Fastpath: do that cpu by itself. */ if (next_cpu >= nr_cpu_ids) { |
25a3a1541 smp: Remove super... |
426 |
if (!cond_func || cond_func(cpu, info)) |
67719ef25 smp: Add a smp_co... |
427 |
smp_call_function_single(cpu, func, info, wait); |
54b11e6d5 cpumask: smp_call... |
428 |
return; |
3d4422332 Add generic helpe... |
429 |
} |
bb964a92c kernel misc: Repl... |
430 |
cfd = this_cpu_ptr(&cfd_data); |
45a579192 call_function_man... |
431 |
|
e1d12f327 kernel/smp.c: cle... |
432 |
cpumask_and(cfd->cpumask, mask, cpu_online_mask); |
6c8557bdb smp, cpumask: Use... |
433 |
__cpumask_clear_cpu(this_cpu, cfd->cpumask); |
723aae25d smp_call_function... |
434 435 |
/* Some callers race with other cpus changing the passed mask */ |
e1d12f327 kernel/smp.c: cle... |
436 |
if (unlikely(!cpumask_weight(cfd->cpumask))) |
723aae25d smp_call_function... |
437 |
return; |
3d4422332 Add generic helpe... |
438 |
|
3fc5b3b6a smp: Avoid sendin... |
439 |
cpumask_clear(cfd->cpumask_ipi); |
e1d12f327 kernel/smp.c: cle... |
440 |
for_each_cpu(cpu, cfd->cpumask) { |
966a96711 smp: Avoid using ... |
441 |
call_single_data_t *csd = per_cpu_ptr(cfd->csd, cpu); |
9a46ad6d6 smp: make smp_cal... |
442 |
|
67719ef25 smp: Add a smp_co... |
443 444 |
if (cond_func && !cond_func(cpu, info)) continue; |
9a46ad6d6 smp: make smp_cal... |
445 |
csd_lock(csd); |
8053871d0 smp: Fix smp_call... |
446 447 |
if (wait) csd->flags |= CSD_FLAG_SYNCHRONOUS; |
9a46ad6d6 smp: make smp_cal... |
448 449 |
csd->func = func; csd->info = info; |
3fc5b3b6a smp: Avoid sendin... |
450 |
if (llist_add(&csd->llist, &per_cpu(call_single_queue, cpu))) |
6c8557bdb smp, cpumask: Use... |
451 |
__cpumask_set_cpu(cpu, cfd->cpumask_ipi); |
9a46ad6d6 smp: make smp_cal... |
452 |
} |
561920a0d generic-ipi: fix ... |
453 |
|
3d4422332 Add generic helpe... |
454 |
/* Send a message to all CPUs in the map */ |
3fc5b3b6a smp: Avoid sendin... |
455 |
arch_send_call_function_ipi_mask(cfd->cpumask_ipi); |
3d4422332 Add generic helpe... |
456 |
|
9a46ad6d6 smp: make smp_cal... |
457 |
if (wait) { |
e1d12f327 kernel/smp.c: cle... |
458 |
for_each_cpu(cpu, cfd->cpumask) { |
966a96711 smp: Avoid using ... |
459 |
call_single_data_t *csd; |
e1d12f327 kernel/smp.c: cle... |
460 461 |
csd = per_cpu_ptr(cfd->csd, cpu); |
9a46ad6d6 smp: make smp_cal... |
462 463 464 |
csd_lock_wait(csd); } } |
3d4422332 Add generic helpe... |
465 |
} |
67719ef25 smp: Add a smp_co... |
466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 |
/** * smp_call_function_many(): Run a function on a set of other CPUs. * @mask: The set of cpus to run on (only runs on online subset). * @func: The function to run. This must be fast and non-blocking. * @info: An arbitrary pointer to pass to the function. * @wait: If true, wait (atomically) until function has completed * on other CPUs. * * If @wait is true, then returns once @func has returned. * * You must not call this function with disabled interrupts or from a * hardware interrupt handler or from a bottom half handler. Preemption * must be disabled when calling this function. */ void smp_call_function_many(const struct cpumask *mask, smp_call_func_t func, void *info, bool wait) { smp_call_function_many_cond(mask, func, info, wait, NULL); } |
54b11e6d5 cpumask: smp_call... |
486 |
EXPORT_SYMBOL(smp_call_function_many); |
3d4422332 Add generic helpe... |
487 488 489 490 491 |
/** * smp_call_function(): Run a function on all other CPUs. * @func: The function to run. This must be fast and non-blocking. * @info: An arbitrary pointer to pass to the function. |
0b13fda1e generic-ipi: clea... |
492 493 |
* @wait: If true, wait (atomically) until function has completed * on other CPUs. |
3d4422332 Add generic helpe... |
494 |
* |
54b11e6d5 cpumask: smp_call... |
495 |
* Returns 0. |
3d4422332 Add generic helpe... |
496 497 |
* * If @wait is true, then returns once @func has returned; otherwise |
72f279b25 generic-ipi: Fix ... |
498 |
* it returns just before the target cpu calls @func. |
3d4422332 Add generic helpe... |
499 500 501 502 |
* * You must not call this function with disabled interrupts or from a * hardware interrupt handler or from a bottom half handler. */ |
caa759323 smp: Remove smp_c... |
503 |
void smp_call_function(smp_call_func_t func, void *info, int wait) |
3d4422332 Add generic helpe... |
504 |
{ |
3d4422332 Add generic helpe... |
505 |
preempt_disable(); |
54b11e6d5 cpumask: smp_call... |
506 |
smp_call_function_many(cpu_online_mask, func, info, wait); |
3d4422332 Add generic helpe... |
507 |
preempt_enable(); |
3d4422332 Add generic helpe... |
508 509 |
} EXPORT_SYMBOL(smp_call_function); |
351f8f8e6 kernel: clean up ... |
510 |
|
34db18a05 smp: move smp set... |
511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 |
/* Setup configured maximum number of CPUs to activate */ unsigned int setup_max_cpus = NR_CPUS; EXPORT_SYMBOL(setup_max_cpus); /* * Setup routine for controlling SMP activation * * Command-line option of "nosmp" or "maxcpus=0" will disable SMP * activation entirely (the MPS table probe still happens, though). * * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer * greater than 0, limits the maximum number of CPUs activated in * SMP mode to <NUM>. */ void __weak arch_disable_smp_support(void) { } static int __init nosmp(char *str) { setup_max_cpus = 0; arch_disable_smp_support(); return 0; } early_param("nosmp", nosmp); /* this is hard limit */ static int __init nrcpus(char *str) { int nr_cpus; get_option(&str, &nr_cpus); if (nr_cpus > 0 && nr_cpus < nr_cpu_ids) nr_cpu_ids = nr_cpus; return 0; } early_param("nr_cpus", nrcpus); static int __init maxcpus(char *str) { get_option(&str, &setup_max_cpus); if (setup_max_cpus == 0) arch_disable_smp_support(); return 0; } early_param("maxcpus", maxcpus); /* Setup number of possible processor ids */ |
9b130ad5b treewide: make "n... |
565 |
unsigned int nr_cpu_ids __read_mostly = NR_CPUS; |
34db18a05 smp: move smp set... |
566 567 568 569 570 571 572 573 574 575 576 |
EXPORT_SYMBOL(nr_cpu_ids); /* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */ void __init setup_nr_cpu_ids(void) { nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1; } /* Called by boot processor to activate the rest. */ void __init smp_init(void) { |
92b232782 kernel/smp: Make ... |
577 |
int num_nodes, num_cpus; |
34db18a05 smp: move smp set... |
578 |
|
3bb5d2ee3 smp, idle: Alloca... |
579 |
idle_threads_init(); |
4cb28ced2 cpu/hotplug: Crea... |
580 |
cpuhp_threads_init(); |
3bb5d2ee3 smp, idle: Alloca... |
581 |
|
51111dce2 kernel/smp: Tell ... |
582 583 |
pr_info("Bringing up secondary CPUs ... "); |
b99a26593 cpu/hotplug: Move... |
584 |
bringup_nonboot_cpus(setup_max_cpus); |
34db18a05 smp: move smp set... |
585 |
|
92b232782 kernel/smp: Make ... |
586 587 588 589 590 591 |
num_nodes = num_online_nodes(); num_cpus = num_online_cpus(); pr_info("Brought up %d node%s, %d CPU%s ", num_nodes, (num_nodes > 1 ? "s" : ""), num_cpus, (num_cpus > 1 ? "s" : "")); |
34db18a05 smp: move smp set... |
592 |
/* Any cleanup work */ |
34db18a05 smp: move smp set... |
593 594 |
smp_cpus_done(setup_max_cpus); } |
351f8f8e6 kernel: clean up ... |
595 |
/* |
bd924e8cb smp: Allow on_eac... |
596 597 598 |
* Call a function on all processors. May be used during early boot while * early_boot_irqs_disabled is set. Use local_irq_save/restore() instead * of local_irq_disable/enable(). |
351f8f8e6 kernel: clean up ... |
599 |
*/ |
caa759323 smp: Remove smp_c... |
600 |
void on_each_cpu(void (*func) (void *info), void *info, int wait) |
351f8f8e6 kernel: clean up ... |
601 |
{ |
bd924e8cb smp: Allow on_eac... |
602 |
unsigned long flags; |
351f8f8e6 kernel: clean up ... |
603 604 |
preempt_disable(); |
caa759323 smp: Remove smp_c... |
605 |
smp_call_function(func, info, wait); |
bd924e8cb smp: Allow on_eac... |
606 |
local_irq_save(flags); |
351f8f8e6 kernel: clean up ... |
607 |
func(info); |
bd924e8cb smp: Allow on_eac... |
608 |
local_irq_restore(flags); |
351f8f8e6 kernel: clean up ... |
609 |
preempt_enable(); |
351f8f8e6 kernel: clean up ... |
610 611 |
} EXPORT_SYMBOL(on_each_cpu); |
3fc498f16 smp: introduce a ... |
612 613 614 615 616 617 618 619 620 621 622 623 |
/** * on_each_cpu_mask(): Run a function on processors specified by * cpumask, which may include the local processor. * @mask: The set of cpus to run on (only runs on online subset). * @func: The function to run. This must be fast and non-blocking. * @info: An arbitrary pointer to pass to the function. * @wait: If true, wait (atomically) until function has completed * on other CPUs. * * If @wait is true, then returns once @func has returned. * |
202da4005 kernel/smp.c: qui... |
624 625 626 627 |
* You must not call this function with disabled interrupts or from a * hardware interrupt handler or from a bottom half handler. The * exception is that it may be used during early boot while * early_boot_irqs_disabled is set. |
3fc498f16 smp: introduce a ... |
628 629 630 631 632 633 634 635 |
*/ void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func, void *info, bool wait) { int cpu = get_cpu(); smp_call_function_many(mask, func, info, wait); if (cpumask_test_cpu(cpu, mask)) { |
202da4005 kernel/smp.c: qui... |
636 637 |
unsigned long flags; local_irq_save(flags); |
3fc498f16 smp: introduce a ... |
638 |
func(info); |
202da4005 kernel/smp.c: qui... |
639 |
local_irq_restore(flags); |
3fc498f16 smp: introduce a ... |
640 641 642 643 |
} put_cpu(); } EXPORT_SYMBOL(on_each_cpu_mask); |
b3a7e98e0 smp: add func to ... |
644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 |
/* * on_each_cpu_cond(): Call a function on each processor for which * the supplied function cond_func returns true, optionally waiting * for all the required CPUs to finish. This may include the local * processor. * @cond_func: A callback function that is passed a cpu id and * the the info parameter. The function is called * with preemption disabled. The function should * return a blooean value indicating whether to IPI * the specified CPU. * @func: The function to run on all applicable CPUs. * This must be fast and non-blocking. * @info: An arbitrary pointer to pass to both functions. * @wait: If true, wait (atomically) until function has * completed on other CPUs. |
b3a7e98e0 smp: add func to ... |
660 661 662 663 664 665 666 |
* * Preemption is disabled to protect against CPUs going offline but not online. * CPUs going online during the call will not be seen or sent an IPI. * * You must not call this function with disabled interrupts or * from a hardware interrupt handler or from a bottom half handler. */ |
5671d814d smp: Use smp_cond... |
667 |
void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func, |
cb923159b smp: Remove alloc... |
668 |
void *info, bool wait, const struct cpumask *mask) |
b3a7e98e0 smp: add func to ... |
669 |
{ |
67719ef25 smp: Add a smp_co... |
670 671 672 673 674 675 676 677 678 |
int cpu = get_cpu(); smp_call_function_many_cond(mask, func, info, wait, cond_func); if (cpumask_test_cpu(cpu, mask) && cond_func(cpu, info)) { unsigned long flags; local_irq_save(flags); func(info); local_irq_restore(flags); |
b3a7e98e0 smp: add func to ... |
679 |
} |
67719ef25 smp: Add a smp_co... |
680 |
put_cpu(); |
b3a7e98e0 smp: add func to ... |
681 |
} |
7d49b28a8 smp,cpumask: intr... |
682 |
EXPORT_SYMBOL(on_each_cpu_cond_mask); |
5671d814d smp: Use smp_cond... |
683 |
void on_each_cpu_cond(smp_cond_func_t cond_func, smp_call_func_t func, |
cb923159b smp: Remove alloc... |
684 |
void *info, bool wait) |
7d49b28a8 smp,cpumask: intr... |
685 |
{ |
cb923159b smp: Remove alloc... |
686 |
on_each_cpu_cond_mask(cond_func, func, info, wait, cpu_online_mask); |
7d49b28a8 smp,cpumask: intr... |
687 |
} |
b3a7e98e0 smp: add func to ... |
688 |
EXPORT_SYMBOL(on_each_cpu_cond); |
f37f435f3 smp: Implement ki... |
689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 |
static void do_nothing(void *unused) { } /** * kick_all_cpus_sync - Force all cpus out of idle * * Used to synchronize the update of pm_idle function pointer. It's * called after the pointer is updated and returns after the dummy * callback function has been executed on all cpus. The execution of * the function can only happen on the remote cpus after they have * left the idle function which had been called via pm_idle function * pointer. So it's guaranteed that nothing uses the previous pointer * anymore. */ void kick_all_cpus_sync(void) { /* Make sure the change is visible before we kick the cpus */ smp_mb(); smp_call_function(do_nothing, NULL, 1); } EXPORT_SYMBOL_GPL(kick_all_cpus_sync); |
c6f4459fc smp: Add new wake... |
712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 |
/** * wake_up_all_idle_cpus - break all cpus out of idle * wake_up_all_idle_cpus try to break all cpus which is in idle state even * including idle polling cpus, for non-idle cpus, we will do nothing * for them. */ void wake_up_all_idle_cpus(void) { int cpu; preempt_disable(); for_each_online_cpu(cpu) { if (cpu == smp_processor_id()) continue; wake_up_if_idle(cpu); } preempt_enable(); } EXPORT_SYMBOL_GPL(wake_up_all_idle_cpus); |
df8ce9d78 smp: Add function... |
733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 |
/** * smp_call_on_cpu - Call a function on a specific cpu * * Used to call a function on a specific cpu and wait for it to return. * Optionally make sure the call is done on a specified physical cpu via vcpu * pinning in order to support virtualized environments. */ struct smp_call_on_cpu_struct { struct work_struct work; struct completion done; int (*func)(void *); void *data; int ret; int cpu; }; static void smp_call_on_cpu_callback(struct work_struct *work) { struct smp_call_on_cpu_struct *sscs; sscs = container_of(work, struct smp_call_on_cpu_struct, work); if (sscs->cpu >= 0) hypervisor_pin_vcpu(sscs->cpu); sscs->ret = sscs->func(sscs->data); if (sscs->cpu >= 0) hypervisor_pin_vcpu(-1); complete(&sscs->done); } int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys) { struct smp_call_on_cpu_struct sscs = { |
df8ce9d78 smp: Add function... |
767 768 769 770 771 |
.done = COMPLETION_INITIALIZER_ONSTACK(sscs.done), .func = func, .data = par, .cpu = phys ? cpu : -1, }; |
8db549491 smp: Allocate smp... |
772 |
INIT_WORK_ONSTACK(&sscs.work, smp_call_on_cpu_callback); |
df8ce9d78 smp: Add function... |
773 774 775 776 777 778 779 780 781 |
if (cpu >= nr_cpu_ids || !cpu_online(cpu)) return -ENXIO; queue_work_on(cpu, system_wq, &sscs.work); wait_for_completion(&sscs.done); return sscs.ret; } EXPORT_SYMBOL_GPL(smp_call_on_cpu); |