72 lines
1.6 KiB
C
72 lines
1.6 KiB
C
/*
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* SMP support for R-Mobile / SH-Mobile
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*
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* Copyright (C) 2010 Magnus Damm
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*
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* Based on realview, Copyright (C) 2002 ARM Ltd, 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/kernel.h>
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#include <linux/errno.h>
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#include <linux/smp.h>
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#include <linux/cpumask.h>
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#include <linux/delay.h>
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#include <mach/common.h>
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#include <asm/cacheflush.h>
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static cpumask_t dead_cpus;
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int platform_cpu_kill(unsigned int cpu)
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{
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int k;
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/* this function is running on another CPU than the offline target,
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* here we need wait for shutdown code in platform_cpu_die() to
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* finish before asking SoC-specific code to power off the CPU core.
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*/
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for (k = 0; k < 1000; k++) {
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if (cpumask_test_cpu(cpu, &dead_cpus))
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return shmobile_platform_cpu_kill(cpu);
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mdelay(1);
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}
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return 0;
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}
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void platform_cpu_die(unsigned int cpu)
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{
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/* hardware shutdown code running on the CPU that is being offlined */
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flush_cache_all();
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dsb();
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/* notify platform_cpu_kill() that hardware shutdown is finished */
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cpumask_set_cpu(cpu, &dead_cpus);
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/* wait for SoC code in platform_cpu_kill() to shut off CPU core
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* power. CPU bring up starts from the reset vector.
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*/
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while (1) {
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/*
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* here's the WFI
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*/
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asm(".word 0xe320f003\n"
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:
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:
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: "memory", "cc");
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}
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}
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int platform_cpu_disable(unsigned int cpu)
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{
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cpumask_clear_cpu(cpu, &dead_cpus);
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/*
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* we don't allow CPU 0 to be shutdown (it is still too special
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* e.g. clock tick interrupts)
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*/
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return cpu == 0 ? -EPERM : 0;
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}
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