smp-sh73a0.c

/*
 * SMP support for R-Mobile / SH-Mobile - sh73a0 portion
 *
 * Copyright (C) 2010  Magnus Damm
 * Copyright (C) 2010  Takashi Yoshii
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/irqchip/arm-gic.h>
#include <mach/common.h>
#include <asm/smp_plat.h>
#include <mach/sh73a0.h>
#include <asm/smp_scu.h>
#include <asm/smp_twd.h>

#define WUPCR		IOMEM(0xe6151010)
#define SRESCR		IOMEM(0xe6151018)
#define PSTR		IOMEM(0xe6151040)
#define SBAR		IOMEM(0xe6180020)
#define APARMBAREA	IOMEM(0xe6f10020)

static void __iomem *scu_base_addr(void)
{
	return (void __iomem *)0xf0000000;
}

static DEFINE_SPINLOCK(scu_lock);
static unsigned long tmp;

#ifdef CONFIG_HAVE_ARM_TWD
static DEFINE_TWD_LOCAL_TIMER(twd_local_timer, 0xf0000600, 29);
void __init sh73a0_register_twd(void)
{
	twd_local_timer_register(&twd_local_timer);
}
#endif

static void modify_scu_cpu_psr(unsigned long set, unsigned long clr)
{
	void __iomem *scu_base = scu_base_addr();

	spin_lock(&scu_lock);
	tmp = __raw_readl(scu_base + 8);
	tmp &= ~clr;
	tmp |= set;
	spin_unlock(&scu_lock);

	/* disable cache coherency after releasing the lock */
	__raw_writel(tmp, scu_base + 8);
}

static unsigned int __init sh73a0_get_core_count(void)
{
	void __iomem *scu_base = scu_base_addr();

	return scu_get_core_count(scu_base);
}

static void __cpuinit sh73a0_secondary_init(unsigned int cpu)
{
	gic_secondary_init(0);
}

static int __cpuinit sh73a0_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
	cpu = cpu_logical_map(cpu);

	/* enable cache coherency */
	modify_scu_cpu_psr(0, 3 << (cpu * 8));

	if (((__raw_readl(PSTR) >> (4 * cpu)) & 3) == 3)
		__raw_writel(1 << cpu, WUPCR);	/* wake up */
	else
		__raw_writel(1 << cpu, SRESCR);	/* reset */

	return 0;
}

static void __init sh73a0_smp_prepare_cpus(unsigned int max_cpus)
{
	int cpu = cpu_logical_map(0);

	scu_enable(scu_base_addr());

	/* Map the reset vector (in headsmp.S) */
	__raw_writel(0, APARMBAREA);      /* 4k */
	__raw_writel(__pa(shmobile_secondary_vector), SBAR);

	/* enable cache coherency on CPU0 */
	modify_scu_cpu_psr(0, 3 << (cpu * 8));
}

static void __init sh73a0_smp_init_cpus(void)
{
	unsigned int ncores = sh73a0_get_core_count();

	shmobile_smp_init_cpus(ncores);
}

static int __maybe_unused sh73a0_cpu_kill(unsigned int cpu)
{
	int k;

	/* this function is running on another CPU than the offline target,
	 * here we need wait for shutdown code in platform_cpu_die() to
	 * finish before asking SoC-specific code to power off the CPU core.
	 */
	for (k = 0; k < 1000; k++) {
		if (shmobile_cpu_is_dead(cpu))
			return 1;

		mdelay(1);
	}

	return 0;
}


struct smp_operations sh73a0_smp_ops __initdata = {
	.smp_init_cpus		= sh73a0_smp_init_cpus,
	.smp_prepare_cpus	= sh73a0_smp_prepare_cpus,
	.smp_secondary_init	= sh73a0_secondary_init,
	.smp_boot_secondary	= sh73a0_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
	.cpu_kill		= sh73a0_cpu_kill,
	.cpu_die		= shmobile_cpu_die,
	.cpu_disable		= shmobile_cpu_disable,
#endif
};