linux/arch/arm/mach-shmobile/platsmp.c
Magnus Damm 1c51ed4fb9 ARM: mach-shmobile: SMP base support
Add SMP base support for R-Mobile / SH-Mobile processors.

This patch contains all base code to support CONFIG_SMP
regardless of ARCH_SHMOBILE processor type. Both local timer
and CPU hotplug are supported, but no processor specific
code is included.

At this point only the default behavior is in place, so
a single core will always be used even though CONFIG_SMP
is enabled on multicore systems.

The SMP Kconfig entry for arch/arm/Kconfig is excluded from
this patch to simplify merging.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-12-14 18:15:44 +09:00

74 lines
1.5 KiB
C

/*
* SMP support for R-Mobile / SH-Mobile
*
* Copyright (C) 2010 Magnus Damm
*
* Based on vexpress, 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/delay.h>
#include <linux/device.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <asm/localtimer.h>
static unsigned int __init shmobile_smp_get_core_count(void)
{
return 1;
}
static void __init shmobile_smp_prepare_cpus(void)
{
/* do nothing for now */
}
void __cpuinit platform_secondary_init(unsigned int cpu)
{
trace_hardirqs_off();
}
int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
{
return -ENOSYS;
}
void __init smp_init_cpus(void)
{
unsigned int ncores = shmobile_smp_get_core_count();
unsigned int i;
for (i = 0; i < ncores; i++)
set_cpu_possible(i, true);
}
void __init smp_prepare_cpus(unsigned int max_cpus)
{
unsigned int ncores = shmobile_smp_get_core_count();
unsigned int cpu = smp_processor_id();
int i;
smp_store_cpu_info(cpu);
if (max_cpus > ncores)
max_cpus = ncores;
for (i = 0; i < max_cpus; i++)
set_cpu_present(i, true);
if (max_cpus > 1) {
shmobile_smp_prepare_cpus();
/*
* Enable the local timer or broadcast device for the
* boot CPU, but only if we have more than one CPU.
*/
percpu_timer_setup();
}
}