mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 10:04:12 +08:00
9f1890a5de
Signed-off-by: Jeff Ohlstein <johlstei@codeaurora.org> Signed-off-by: David Brown <davidb@codeaurora.org>
92 lines
1.8 KiB
C
92 lines
1.8 KiB
C
/*
|
|
* Copyright (C) 2002 ARM Ltd.
|
|
* All Rights Reserved
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/smp.h>
|
|
|
|
#include <asm/cacheflush.h>
|
|
|
|
extern volatile int pen_release;
|
|
|
|
static inline void cpu_enter_lowpower(void)
|
|
{
|
|
/* Just flush the cache. Changing the coherency is not yet
|
|
* available on msm. */
|
|
flush_cache_all();
|
|
}
|
|
|
|
static inline void cpu_leave_lowpower(void)
|
|
{
|
|
}
|
|
|
|
static inline void platform_do_lowpower(unsigned int cpu)
|
|
{
|
|
/* Just enter wfi for now. TODO: Properly shut off the cpu. */
|
|
for (;;) {
|
|
/*
|
|
* here's the WFI
|
|
*/
|
|
asm("wfi"
|
|
:
|
|
:
|
|
: "memory", "cc");
|
|
|
|
if (pen_release == cpu) {
|
|
/*
|
|
* OK, proper wakeup, we're done
|
|
*/
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* getting here, means that we have come out of WFI without
|
|
* having been woken up - this shouldn't happen
|
|
*
|
|
* The trouble is, letting people know about this is not really
|
|
* possible, since we are currently running incoherently, and
|
|
* therefore cannot safely call printk() or anything else
|
|
*/
|
|
pr_debug("CPU%u: spurious wakeup call\n", cpu);
|
|
}
|
|
}
|
|
|
|
int platform_cpu_kill(unsigned int cpu)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* platform-specific code to shutdown a CPU
|
|
*
|
|
* Called with IRQs disabled
|
|
*/
|
|
void platform_cpu_die(unsigned int cpu)
|
|
{
|
|
/*
|
|
* we're ready for shutdown now, so do it
|
|
*/
|
|
cpu_enter_lowpower();
|
|
platform_do_lowpower(cpu);
|
|
|
|
/*
|
|
* bring this CPU back into the world of cache
|
|
* coherency, and then restore interrupts
|
|
*/
|
|
cpu_leave_lowpower();
|
|
}
|
|
|
|
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;
|
|
}
|