omap-hotplug.c

Go to the documentation of this file.

/*
 * OMAP4 SMP cpu-hotplug support
 *
 * Copyright (C) 2010 Texas Instruments, Inc.
 * Author:
 *      Santosh Shilimkar <[email protected]>
 *
 * 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 "omap-wakeupgen.h"

#include "common.h"

#include "powerdomain.h"

/*
 * platform-specific code to shutdown a CPU
 * Called with IRQs disabled
 */
void __ref omap4_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);
    }
}