mirror of https://gitee.com/openkylin/linux.git
76 lines
1.5 KiB
C
76 lines
1.5 KiB
C
/*
|
|
* 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;
|
|
}
|