206 lines
4.2 KiB
C
206 lines
4.2 KiB
C
/*
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* arch/sh/kernel/smp.c
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*
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* SMP support for the SuperH processors.
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*
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* Copyright (C) 2002, 2003 Paul Mundt
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/config.h>
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#include <linux/cache.h>
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#include <linux/cpumask.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/spinlock.h>
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#include <linux/threads.h>
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#include <linux/module.h>
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#include <linux/time.h>
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#include <linux/timex.h>
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#include <linux/sched.h>
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#include <linux/module.h>
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#include <asm/atomic.h>
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#include <asm/processor.h>
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#include <asm/system.h>
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#include <asm/mmu_context.h>
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#include <asm/smp.h>
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/*
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* This was written with the Sega Saturn (SMP SH-2 7604) in mind,
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* but is designed to be usable regardless if there's an MMU
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* present or not.
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*/
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struct sh_cpuinfo cpu_data[NR_CPUS];
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extern void per_cpu_trap_init(void);
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cpumask_t cpu_possible_map;
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EXPORT_SYMBOL(cpu_possible_map);
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cpumask_t cpu_online_map;
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static atomic_t cpus_booted = ATOMIC_INIT(0);
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/* These are defined by the board-specific code. */
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/*
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* Cause the function described by call_data to be executed on the passed
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* cpu. When the function has finished, increment the finished field of
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* call_data.
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*/
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void __smp_send_ipi(unsigned int cpu, unsigned int action);
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/*
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* Find the number of available processors
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*/
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unsigned int __smp_probe_cpus(void);
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/*
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* Start a particular processor
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*/
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void __smp_slave_init(unsigned int cpu);
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/*
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* Run specified function on a particular processor.
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*/
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void __smp_call_function(unsigned int cpu);
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static inline void __init smp_store_cpu_info(unsigned int cpu)
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{
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cpu_data[cpu].loops_per_jiffy = loops_per_jiffy;
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}
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void __init smp_prepare_cpus(unsigned int max_cpus)
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{
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unsigned int cpu = smp_processor_id();
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int i;
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atomic_set(&cpus_booted, 1);
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smp_store_cpu_info(cpu);
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for (i = 0; i < __smp_probe_cpus(); i++)
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cpu_set(i, cpu_possible_map);
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}
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void __devinit smp_prepare_boot_cpu(void)
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{
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unsigned int cpu = smp_processor_id();
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cpu_set(cpu, cpu_online_map);
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cpu_set(cpu, cpu_possible_map);
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}
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int __cpu_up(unsigned int cpu)
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{
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struct task_struct *tsk;
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tsk = fork_idle(cpu);
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if (IS_ERR(tsk))
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panic("Failed forking idle task for cpu %d\n", cpu);
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task_thread_info(tsk)->cpu = cpu;
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cpu_set(cpu, cpu_online_map);
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return 0;
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}
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int start_secondary(void *unused)
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{
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unsigned int cpu;
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cpu = smp_processor_id();
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atomic_inc(&init_mm.mm_count);
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current->active_mm = &init_mm;
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smp_store_cpu_info(cpu);
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__smp_slave_init(cpu);
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preempt_disable();
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per_cpu_trap_init();
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atomic_inc(&cpus_booted);
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cpu_idle();
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return 0;
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}
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void __init smp_cpus_done(unsigned int max_cpus)
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{
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smp_mb();
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}
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void smp_send_reschedule(int cpu)
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{
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__smp_send_ipi(cpu, SMP_MSG_RESCHEDULE);
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}
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static void stop_this_cpu(void *unused)
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{
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cpu_clear(smp_processor_id(), cpu_online_map);
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local_irq_disable();
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for (;;)
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cpu_relax();
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}
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void smp_send_stop(void)
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{
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smp_call_function(stop_this_cpu, 0, 1, 0);
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}
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struct smp_fn_call_struct smp_fn_call = {
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.lock = SPIN_LOCK_UNLOCKED,
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.finished = ATOMIC_INIT(0),
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};
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/*
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* The caller of this wants the passed function to run on every cpu. If wait
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* is set, wait until all cpus have finished the function before returning.
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* The lock is here to protect the call structure.
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* You must not call this function with disabled interrupts or from a
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* hardware interrupt handler or from a bottom half handler.
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*/
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int smp_call_function(void (*func)(void *info), void *info, int retry, int wait)
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{
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unsigned int nr_cpus = atomic_read(&cpus_booted);
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int i;
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if (nr_cpus < 2)
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return 0;
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/* Can deadlock when called with interrupts disabled */
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WARN_ON(irqs_disabled());
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spin_lock(&smp_fn_call.lock);
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atomic_set(&smp_fn_call.finished, 0);
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smp_fn_call.fn = func;
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smp_fn_call.data = info;
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for (i = 0; i < nr_cpus; i++)
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if (i != smp_processor_id())
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__smp_call_function(i);
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if (wait)
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while (atomic_read(&smp_fn_call.finished) != (nr_cpus - 1));
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spin_unlock(&smp_fn_call.lock);
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return 0;
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}
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/* Not really SMP stuff ... */
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int setup_profiling_timer(unsigned int multiplier)
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{
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return 0;
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}
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