76 lines
1.5 KiB
C
76 lines
1.5 KiB
C
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/*
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* Copyright (C) STMicroelectronics 2009
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* Copyright (C) ST-Ericsson SA 2010
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*
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* License Terms: GNU General Public License v2
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* Based on ARM realview platform
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*
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* Author: Sundar Iyer <sundar.iyer@stericsson.com>
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*
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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/completion.h>
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#include <asm/cacheflush.h>
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extern volatile int pen_release;
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static DECLARE_COMPLETION(cpu_killed);
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static inline void platform_do_lowpower(unsigned int cpu)
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{
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flush_cache_all();
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/* we put the platform to just WFI */
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for (;;) {
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__asm__ __volatile__("dsb\n\t" "wfi\n\t"
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: : : "memory");
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if (pen_release == cpu) {
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/*
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* OK, proper wakeup, we're done
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*/
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break;
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}
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}
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}
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int platform_cpu_kill(unsigned int cpu)
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{
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return wait_for_completion_timeout(&cpu_killed, 5000);
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}
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/*
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* platform-specific code to shutdown a CPU
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*
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* Called with IRQs disabled
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*/
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void platform_cpu_die(unsigned int cpu)
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{
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#ifdef DEBUG
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unsigned int this_cpu = hard_smp_processor_id();
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if (cpu != this_cpu) {
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printk(KERN_CRIT "Eek! platform_cpu_die running on %u, should be %u\n",
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this_cpu, cpu);
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BUG();
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}
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#endif
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printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
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complete(&cpu_killed);
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/* directly enter low power state, skipping secure registers */
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platform_do_lowpower(cpu);
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}
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int platform_cpu_disable(unsigned int cpu)
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{
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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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