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

73 lines
1.6 KiB
C

/*
* 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 "omap-wakeupgen.h"
#include "common.h"
#include "powerdomain.h"
/*
* platform-specific code to shutdown a CPU
* Called with IRQs disabled
*/
void omap4_cpu_die(unsigned int cpu)
{
unsigned int boot_cpu = 0;
void __iomem *base = omap_get_wakeupgen_base();
/*
* 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 {
writel_relaxed(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() >> 9;
else
boot_cpu =
readl_relaxed(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);
}
}
/* Needed by kexec and platform_can_cpu_hotplug() */
int omap4_cpu_kill(unsigned int cpu)
{
return 1;
}