linux/arch/arm/mach-shmobile/smp-sh73a0.c
Ulrich Hecht dc784e73b4 ARM: mach-shmobile: sh73a0: allow unplugging of CPU0
sh73a0 deals fine with disabling any core, so we should permit it.

Signed-off-by: Ulrich Hecht <ulrich.hecht@gmail.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-01-30 13:07:59 +09:00

149 lines
3.7 KiB
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/cacheflush.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)
#define PSTR_SHUTDOWN_MODE 3
static void __iomem *scu_base_addr(void)
{
return (void __iomem *)0xf0000000;
}
#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 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);
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)
{
scu_enable(scu_base_addr());
/* Map the reset vector (in headsmp-sh73a0.S) */
__raw_writel(0, APARMBAREA); /* 4k */
__raw_writel(__pa(sh73a0_secondary_vector), SBAR);
/* enable cache coherency on booting CPU */
scu_power_mode(scu_base_addr(), SCU_PM_NORMAL);
}
static void __init sh73a0_smp_init_cpus(void)
{
unsigned int ncores = sh73a0_get_core_count();
shmobile_smp_init_cpus(ncores);
}
#ifdef CONFIG_HOTPLUG_CPU
static int sh73a0_cpu_kill(unsigned int cpu)
{
int k;
u32 pstr;
/*
* wait until the power status register confirms the shutdown of the
* offline target
*/
for (k = 0; k < 1000; k++) {
pstr = (__raw_readl(PSTR) >> (4 * cpu)) & 3;
if (pstr == PSTR_SHUTDOWN_MODE)
return 1;
mdelay(1);
}
return 0;
}
static void sh73a0_cpu_die(unsigned int cpu)
{
/*
* The ARM MPcore does not issue a cache coherency request for the L1
* cache when powering off single CPUs. We must take care of this and
* further caches.
*/
dsb();
flush_cache_all();
/* Set power off mode. This takes the CPU out of the MP cluster */
scu_power_mode(scu_base_addr(), SCU_PM_POWEROFF);
/* Enter shutdown mode */
cpu_do_idle();
}
#endif /* CONFIG_HOTPLUG_CPU */
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 = sh73a0_cpu_die,
.cpu_disable = shmobile_cpu_disable_any,
#endif
};