1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
396 lines
7.9 KiB
C
396 lines
7.9 KiB
C
/*
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* linux/arch/arm/kernel/smp.c
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*
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* Copyright (C) 2002 ARM Limited, All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/config.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/sched.h>
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#include <linux/interrupt.h>
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#include <linux/cache.h>
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#include <linux/profile.h>
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#include <linux/errno.h>
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#include <linux/mm.h>
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#include <linux/cpu.h>
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#include <linux/smp.h>
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#include <linux/seq_file.h>
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#include <asm/atomic.h>
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#include <asm/cacheflush.h>
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#include <asm/cpu.h>
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#include <asm/processor.h>
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#include <asm/tlbflush.h>
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#include <asm/ptrace.h>
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/*
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* bitmask of present and online CPUs.
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* The present bitmask indicates that the CPU is physically present.
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* The online bitmask indicates that the CPU is up and running.
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*/
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cpumask_t cpu_present_mask;
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cpumask_t cpu_online_map;
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/*
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* structures for inter-processor calls
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* - A collection of single bit ipi messages.
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*/
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struct ipi_data {
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spinlock_t lock;
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unsigned long ipi_count;
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unsigned long bits;
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};
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static DEFINE_PER_CPU(struct ipi_data, ipi_data) = {
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.lock = SPIN_LOCK_UNLOCKED,
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};
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enum ipi_msg_type {
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IPI_TIMER,
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IPI_RESCHEDULE,
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IPI_CALL_FUNC,
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IPI_CPU_STOP,
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};
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struct smp_call_struct {
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void (*func)(void *info);
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void *info;
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int wait;
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cpumask_t pending;
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cpumask_t unfinished;
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};
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static struct smp_call_struct * volatile smp_call_function_data;
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static DEFINE_SPINLOCK(smp_call_function_lock);
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int __init __cpu_up(unsigned int cpu)
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{
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struct task_struct *idle;
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int ret;
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/*
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* Spawn a new process manually. Grab a pointer to
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* its task struct so we can mess with it
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*/
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idle = fork_idle(cpu);
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if (IS_ERR(idle)) {
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printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
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return PTR_ERR(idle);
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}
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/*
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* Now bring the CPU into our world.
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*/
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ret = boot_secondary(cpu, idle);
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if (ret) {
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printk(KERN_CRIT "cpu_up: processor %d failed to boot\n", cpu);
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/*
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* FIXME: We need to clean up the new idle thread. --rmk
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*/
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}
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return ret;
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}
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/*
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* Called by both boot and secondaries to move global data into
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* per-processor storage.
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*/
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void __init smp_store_cpu_info(unsigned int cpuid)
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{
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struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpuid);
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cpu_info->loops_per_jiffy = loops_per_jiffy;
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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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int cpu;
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unsigned long bogosum = 0;
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for_each_online_cpu(cpu)
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bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy;
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printk(KERN_INFO "SMP: Total of %d processors activated "
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"(%lu.%02lu BogoMIPS).\n",
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num_online_cpus(),
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bogosum / (500000/HZ),
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(bogosum / (5000/HZ)) % 100);
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}
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void __init 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_present_mask);
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cpu_set(cpu, cpu_online_map);
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}
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static void send_ipi_message(cpumask_t callmap, enum ipi_msg_type msg)
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{
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unsigned long flags;
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unsigned int cpu;
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local_irq_save(flags);
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for_each_cpu_mask(cpu, callmap) {
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struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
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spin_lock(&ipi->lock);
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ipi->bits |= 1 << msg;
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spin_unlock(&ipi->lock);
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}
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/*
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* Call the platform specific cross-CPU call function.
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*/
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smp_cross_call(callmap);
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local_irq_restore(flags);
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}
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/*
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* You must not call this function with disabled interrupts, from a
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* hardware interrupt handler, nor from a bottom half handler.
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*/
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int smp_call_function_on_cpu(void (*func)(void *info), void *info, int retry,
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int wait, cpumask_t callmap)
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{
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struct smp_call_struct data;
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unsigned long timeout;
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int ret = 0;
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data.func = func;
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data.info = info;
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data.wait = wait;
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cpu_clear(smp_processor_id(), callmap);
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if (cpus_empty(callmap))
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goto out;
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data.pending = callmap;
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if (wait)
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data.unfinished = callmap;
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/*
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* try to get the mutex on smp_call_function_data
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*/
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spin_lock(&smp_call_function_lock);
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smp_call_function_data = &data;
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send_ipi_message(callmap, IPI_CALL_FUNC);
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timeout = jiffies + HZ;
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while (!cpus_empty(data.pending) && time_before(jiffies, timeout))
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barrier();
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/*
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* did we time out?
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*/
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if (!cpus_empty(data.pending)) {
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/*
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* this may be causing our panic - report it
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*/
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printk(KERN_CRIT
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"CPU%u: smp_call_function timeout for %p(%p)\n"
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" callmap %lx pending %lx, %swait\n",
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smp_processor_id(), func, info, callmap, data.pending,
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wait ? "" : "no ");
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/*
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* TRACE
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*/
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timeout = jiffies + (5 * HZ);
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while (!cpus_empty(data.pending) && time_before(jiffies, timeout))
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barrier();
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if (cpus_empty(data.pending))
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printk(KERN_CRIT " RESOLVED\n");
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else
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printk(KERN_CRIT " STILL STUCK\n");
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}
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/*
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* whatever happened, we're done with the data, so release it
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*/
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smp_call_function_data = NULL;
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spin_unlock(&smp_call_function_lock);
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if (!cpus_empty(data.pending)) {
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ret = -ETIMEDOUT;
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goto out;
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}
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if (wait)
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while (!cpus_empty(data.unfinished))
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barrier();
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out:
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return 0;
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}
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int smp_call_function(void (*func)(void *info), void *info, int retry,
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int wait)
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{
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return smp_call_function_on_cpu(func, info, retry, wait,
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cpu_online_map);
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}
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void show_ipi_list(struct seq_file *p)
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{
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unsigned int cpu;
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seq_puts(p, "IPI:");
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for_each_online_cpu(cpu)
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seq_printf(p, " %10lu", per_cpu(ipi_data, cpu).ipi_count);
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seq_putc(p, '\n');
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}
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static void ipi_timer(struct pt_regs *regs)
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{
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int user = user_mode(regs);
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irq_enter();
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profile_tick(CPU_PROFILING, regs);
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update_process_times(user);
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irq_exit();
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}
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/*
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* ipi_call_function - handle IPI from smp_call_function()
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*
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* Note that we copy data out of the cross-call structure and then
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* let the caller know that we're here and have done with their data
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*/
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static void ipi_call_function(unsigned int cpu)
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{
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struct smp_call_struct *data = smp_call_function_data;
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void (*func)(void *info) = data->func;
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void *info = data->info;
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int wait = data->wait;
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cpu_clear(cpu, data->pending);
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func(info);
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if (wait)
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cpu_clear(cpu, data->unfinished);
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}
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static DEFINE_SPINLOCK(stop_lock);
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/*
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* ipi_cpu_stop - handle IPI from smp_send_stop()
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*/
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static void ipi_cpu_stop(unsigned int cpu)
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{
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spin_lock(&stop_lock);
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printk(KERN_CRIT "CPU%u: stopping\n", cpu);
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dump_stack();
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spin_unlock(&stop_lock);
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cpu_clear(cpu, cpu_online_map);
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local_fiq_disable();
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local_irq_disable();
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while (1)
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cpu_relax();
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}
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/*
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* Main handler for inter-processor interrupts
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*
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* For ARM, the ipimask now only identifies a single
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* category of IPI (Bit 1 IPIs have been replaced by a
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* different mechanism):
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*
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* Bit 0 - Inter-processor function call
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*/
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void do_IPI(struct pt_regs *regs)
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{
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unsigned int cpu = smp_processor_id();
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struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
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ipi->ipi_count++;
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for (;;) {
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unsigned long msgs;
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spin_lock(&ipi->lock);
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msgs = ipi->bits;
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ipi->bits = 0;
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spin_unlock(&ipi->lock);
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if (!msgs)
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break;
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do {
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unsigned nextmsg;
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nextmsg = msgs & -msgs;
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msgs &= ~nextmsg;
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nextmsg = ffz(~nextmsg);
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switch (nextmsg) {
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case IPI_TIMER:
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ipi_timer(regs);
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break;
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case IPI_RESCHEDULE:
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/*
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* nothing more to do - eveything is
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* done on the interrupt return path
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*/
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break;
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case IPI_CALL_FUNC:
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ipi_call_function(cpu);
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break;
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case IPI_CPU_STOP:
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ipi_cpu_stop(cpu);
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break;
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default:
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printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n",
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cpu, nextmsg);
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break;
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}
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} while (msgs);
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}
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}
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void smp_send_reschedule(int cpu)
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{
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send_ipi_message(cpumask_of_cpu(cpu), IPI_RESCHEDULE);
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}
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void smp_send_timer(void)
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{
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cpumask_t mask = cpu_online_map;
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cpu_clear(smp_processor_id(), mask);
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send_ipi_message(mask, IPI_TIMER);
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}
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void smp_send_stop(void)
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{
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cpumask_t mask = cpu_online_map;
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cpu_clear(smp_processor_id(), mask);
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send_ipi_message(mask, IPI_CPU_STOP);
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}
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/*
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* not supported here
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*/
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int __init setup_profiling_timer(unsigned int multiplier)
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{
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return -EINVAL;
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}
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