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linux-next/arch/arm/mach-shmobile/smp-sh73a0.c
Will Deacon eb50439b92 ARM: 7293/1: logical_cpu_map: decouple CPU mapping from SMP
It turns out that the logical CPU mapping is useful even when !CONFIG_SMP
for manipulation of devices like interrupt and power controllers when
running a UP kernel on a CPU other than 0. This can happen when kexecing
a UP image from an SMP kernel.

In the future, multi-cluster systems running AMP configurations will
require something similar for mapping cluster IDs, so it makes sense to
decouple this logic in preparation for this support.

Acked-by: Yang Bai <hamo.by@gmail.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reported-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-01-23 10:20:05 +00:00

104 lines
2.7 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 <mach/common.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
#include <asm/smp_twd.h>
#include <asm/hardware/gic.h>
#define WUPCR 0xe6151010
#define SRESCR 0xe6151018
#define PSTR 0xe6151040
#define SBAR 0xe6180020
#define APARMBAREA 0xe6f10020
static void __iomem *scu_base_addr(void)
{
return (void __iomem *)0xf0000000;
}
static DEFINE_SPINLOCK(scu_lock);
static unsigned long tmp;
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);
}
unsigned int __init sh73a0_get_core_count(void)
{
void __iomem *scu_base = scu_base_addr();
#ifdef CONFIG_HAVE_ARM_TWD
/* twd_base needs to be initialized before percpu_timer_setup() */
twd_base = (void __iomem *)0xf0000600;
#endif
return scu_get_core_count(scu_base);
}
void __cpuinit sh73a0_secondary_init(unsigned int cpu)
{
gic_secondary_init(0);
}
int __cpuinit sh73a0_boot_secondary(unsigned int cpu)
{
cpu = cpu_logical_map(cpu);
/* enable cache coherency */
modify_scu_cpu_psr(0, 3 << (cpu * 8));
if (((__raw_readw(__io(PSTR)) >> (4 * cpu)) & 3) == 3)
__raw_writel(1 << cpu, __io(WUPCR)); /* wake up */
else
__raw_writel(1 << cpu, __io(SRESCR)); /* reset */
return 0;
}
void __init sh73a0_smp_prepare_cpus(void)
{
int cpu = cpu_logical_map(0);
scu_enable(scu_base_addr());
/* Map the reset vector (in headsmp.S) */
__raw_writel(0, __io(APARMBAREA)); /* 4k */
__raw_writel(__pa(shmobile_secondary_vector), __io(SBAR));
/* enable cache coherency on CPU0 */
modify_scu_cpu_psr(0, 3 << (cpu * 8));
}