linux/arch/arm/mach-shmobile/smp-emev2.c

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/*
* SMP support for Emma Mobile EV2
*
* Copyright (C) 2012 Renesas Solutions Corp.
* Copyright (C) 2012 Magnus Damm
*
* 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 <mach/common.h>
#include <mach/emev2.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
#include <asm/hardware/gic.h>
#include <asm/cacheflush.h>
#define EMEV2_SCU_BASE 0x1e000000
static DEFINE_SPINLOCK(scu_lock);
static void __iomem *scu_base;
static void modify_scu_cpu_psr(unsigned long set, unsigned long clr)
{
unsigned long tmp;
/* we assume this code is running on a different cpu
* than the one that is changing coherency setting */
spin_lock(&scu_lock);
tmp = readl(scu_base + 8);
tmp &= ~clr;
tmp |= set;
writel(tmp, scu_base + 8);
spin_unlock(&scu_lock);
}
unsigned int __init emev2_get_core_count(void)
{
if (!scu_base) {
scu_base = ioremap(EMEV2_SCU_BASE, PAGE_SIZE);
emev2_clock_init(); /* need ioremapped SMU */
}
WARN_ON_ONCE(!scu_base);
return scu_base ? scu_get_core_count(scu_base) : 1;
}
int emev2_platform_cpu_kill(unsigned int cpu)
{
return 0; /* not supported yet */
}
void __cpuinit emev2_secondary_init(unsigned int cpu)
{
gic_secondary_init(0);
}
int __cpuinit emev2_boot_secondary(unsigned int cpu)
{
cpu = cpu_logical_map(cpu);
/* enable cache coherency */
modify_scu_cpu_psr(0, 3 << (cpu * 8));
/* Tell ROM loader about our vector (in headsmp.S) */
emev2_set_boot_vector(__pa(shmobile_secondary_vector));
gic_raise_softirq(cpumask_of(cpu), 1);
return 0;
}
void __init emev2_smp_prepare_cpus(void)
{
int cpu = cpu_logical_map(0);
scu_enable(scu_base);
/* enable cache coherency on CPU0 */
modify_scu_cpu_psr(0, 3 << (cpu * 8));
}