msm: hotplug: support cpu hotplug on msm

Signed-off-by: Jeff Ohlstein <johlstei@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>
This commit is contained in:
Jeff Ohlstein 2010-12-02 12:11:27 -08:00 committed by David Brown
parent 94790ec25f
commit 9f1890a5de
2 changed files with 93 additions and 0 deletions

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@ -20,6 +20,8 @@ obj-$(CONFIG_MSM_SMD) += smd.o smd_debug.o
obj-$(CONFIG_MSM_SMD) += last_radio_log.o
obj-$(CONFIG_MSM_SCM) += scm.o scm-boot.o
obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
obj-$(CONFIG_MACH_TROUT) += board-trout.o board-trout-gpio.o board-trout-mmc.o devices-msm7x00.o
obj-$(CONFIG_MACH_TROUT) += board-trout.o board-trout-gpio.o board-trout-mmc.o board-trout-panel.o devices-msm7x00.o
obj-$(CONFIG_MACH_HALIBUT) += board-halibut.o devices-msm7x00.o

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@ -0,0 +1,91 @@
/*
* 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;
}