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/*
* Copyright (C) STMicroelectronics 2009
* Copyright (C) ST-Ericsson SA 2010
*
* License Terms: GNU General Public License v2
* Based on ARM realview platform
*
* Author: Sundar Iyer <sundar.iyer@stericsson.com>
*
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/smp.h>
#include <linux/completion.h>
#include <asm/cacheflush.h>
extern volatile int pen_release;
static DECLARE_COMPLETION(cpu_killed);
static inline void platform_do_lowpower(unsigned int cpu)
{
flush_cache_all();
/* we put the platform to just WFI */
for (;;) {
__asm__ __volatile__("dsb\n\t" "wfi\n\t"
: : : "memory");
if (pen_release == cpu) {
/*
* OK, proper wakeup, we're done
*/
break;
}
}
}
int platform_cpu_kill(unsigned int cpu)
{
return wait_for_completion_timeout(&cpu_killed, 5000);
}
/*
* platform-specific code to shutdown a CPU
*
* Called with IRQs disabled
*/
void platform_cpu_die(unsigned int cpu)
{
#ifdef DEBUG
unsigned int this_cpu = hard_smp_processor_id();
if (cpu != this_cpu) {
printk(KERN_CRIT "Eek! platform_cpu_die running on %u, should be %u\n",
this_cpu, cpu);
BUG();
}
#endif
printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
complete(&cpu_killed);
/* directly enter low power state, skipping secure registers */
platform_do_lowpower(cpu);
}
int platform_cpu_disable(unsigned int cpu)
{
/*
* we don't allow CPU 0 to be shutdown (it is still too special
* e.g. clock tick interrupts)
*/
return cpu == 0 ? -EPERM : 0;
}
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