linux/arch/arm/mach-omap2/omap-hotplug.c

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/*
* OMAP4 SMP cpu-hotplug support
*
* Copyright (C) 2010 Texas Instruments, Inc.
* Author:
* Santosh Shilimkar <santosh.shilimkar@ti.com>
*
* Platform file needed for the OMAP4 SMP. This file is based on arm
* realview smp platform.
* Copyright (c) 2002 ARM Limited.
*
* 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 <linux/io.h>
#include <asm/cacheflush.h>
#include <mach/omap-wakeupgen.h>
#include "common.h"
#include "powerdomain.h"
int platform_cpu_kill(unsigned int cpu)
{
return 1;
}
/*
* platform-specific code to shutdown a CPU
* Called with IRQs disabled
*/
void __ref platform_cpu_die(unsigned int cpu)
{
unsigned int boot_cpu = 0;
void __iomem *base = omap_get_wakeupgen_base();
flush_cache_all();
dsb();
/*
* we're ready for shutdown now, so do it
*/
if (omap_secure_apis_support()) {
if (omap_modify_auxcoreboot0(0x0, 0x200) != 0x0)
pr_err("Secure clear status failed\n");
} else {
__raw_writel(0, base + OMAP_AUX_CORE_BOOT_0);
}
for (;;) {
/*
* Enter into low power state
*/
omap4_hotplug_cpu(cpu, PWRDM_POWER_OFF);
if (omap_secure_apis_support())
boot_cpu = omap_read_auxcoreboot0();
else
boot_cpu =
__raw_readl(base + OMAP_AUX_CORE_BOOT_0) >> 5;
if (boot_cpu == smp_processor_id()) {
/*
* OK, proper wakeup, we're done
*/
break;
}
pr_debug("CPU%u: spurious wakeup call\n", 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;
}