arch/arm/mach-vexpress/platsmp.c

/*
 *  linux/arch/arm/mach-vexpress/platsmp.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/init.h>
#include <linux/errno.h>
#include <linux/smp.h>
#include <linux/io.h>

#include <asm/smp_scu.h>
#include <asm/unified.h>

#include <mach/ct-ca9x4.h>
#include <mach/motherboard.h>
#define V2M_PA_CS7 0x10000000

#include "core.h"

extern void versatile_secondary_startup(void);

static void __iomem *scu_base_addr(void)
{
	return MMIO_P2V(A9_MPCORE_SCU);
}

/*
 * Initialise the CPU possible map early - this describes the CPUs
 * which may be present or become present in the system.
 */
void __init smp_init_cpus(void)
{
	void __iomem *scu_base = scu_base_addr();
	unsigned int i, ncores;

	ncores = scu_base ? scu_get_core_count(scu_base) : 1;

	/* sanity check */
	if (ncores > NR_CPUS) {
		printk(KERN_WARNING
		       "vexpress: no. of cores (%d) greater than configured "
		       "maximum of %d - clipping\n",
		       ncores, NR_CPUS);
		ncores = NR_CPUS;
	}

	for (i = 0; i < ncores; i++)
		set_cpu_possible(i, true);
}

void __init platform_smp_prepare_cpus(unsigned int max_cpus)
{
	int i;

	/*
	 * Initialise the present map, which describes the set of CPUs
	 * actually populated at the present time.
	 */
	for (i = 0; i < max_cpus; i++)
		set_cpu_present(i, true);

	scu_enable(scu_base_addr());

	/*
	 * Write the address of secondary startup into the
	 * system-wide flags register. The boot monitor waits
	 * until it receives a soft interrupt, and then the
	 * secondary CPU branches to this address.
	 */
	writel(~0, MMIO_P2V(V2M_SYS_FLAGSCLR));
	writel(BSYM(virt_to_phys(versatile_secondary_startup)),
		MMIO_P2V(V2M_SYS_FLAGSSET));
}