68 lines
1.3 KiB
C
68 lines
1.3 KiB
C
/*
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* Common SMP CPU bringup/teardown functions
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*/
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#include <linux/err.h>
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#include <linux/smp.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/percpu.h>
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#include "smpboot.h"
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#ifdef CONFIG_GENERIC_SMP_IDLE_THREAD
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/*
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* For the hotplug case we keep the task structs around and reuse
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* them.
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*/
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static DEFINE_PER_CPU(struct task_struct *, idle_threads);
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struct task_struct * __cpuinit idle_thread_get(unsigned int cpu)
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{
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struct task_struct *tsk = per_cpu(idle_threads, cpu);
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if (!tsk)
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return ERR_PTR(-ENOMEM);
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init_idle(tsk, cpu);
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return tsk;
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}
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void __init idle_thread_set_boot_cpu(void)
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{
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per_cpu(idle_threads, smp_processor_id()) = current;
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}
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/**
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* idle_init - Initialize the idle thread for a cpu
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* @cpu: The cpu for which the idle thread should be initialized
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*
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* Creates the thread if it does not exist.
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*/
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static inline void idle_init(unsigned int cpu)
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{
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struct task_struct *tsk = per_cpu(idle_threads, cpu);
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if (!tsk) {
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tsk = fork_idle(cpu);
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if (IS_ERR(tsk))
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pr_err("SMP: fork_idle() failed for CPU %u\n", cpu);
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else
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per_cpu(idle_threads, cpu) = tsk;
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}
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}
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/**
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* idle_threads_init - Initialize idle threads for all cpus
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*/
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void __init idle_threads_init(void)
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{
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unsigned int cpu, boot_cpu;
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boot_cpu = smp_processor_id();
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for_each_possible_cpu(cpu) {
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if (cpu != boot_cpu)
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idle_init(cpu);
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}
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}
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#endif
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