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linux-next/arch/arm/mach-shmobile/platsmp.c
Magnus Damm f40aaf6da1 ARM: mach-shmobile: r8a7779 SMP support V3
This patch contains r8a7779 SMP support V3 - now including
CPU hotplug offine and online support. The r8a7779 power
domain code is tied together with SMP glue code which allows
us to control the power domains via CPU hotplug.

At this point the kernel boots with the 4 Cortex-A9 cores in
SMP mode and all CPU cores except CPU0 can be hotplugged.

The code in platsmp.c is quite far from pretty, but it is
kept like that intentionally to avoid creating layers of
code that will go away in the near future anyway. The code
needs to be updated when some per-SoC handling code will be
added to the ARM architecture, see the following patch for
more information:
 "[RFC PATCH 0/3] Per SoC descriptor"

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-01-12 11:00:27 +09:00

98 lines
2.0 KiB
C

/*
* SMP support for R-Mobile / SH-Mobile
*
* Copyright (C) 2010 Magnus Damm
* Copyright (C) 2011 Paul Mundt
*
* 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/hardware/gic.h>
#include <asm/localtimer.h>
#include <asm/mach-types.h>
#include <mach/common.h>
#define is_sh73a0() (machine_is_ag5evm() || machine_is_kota2())
#define is_r8a7779() machine_is_marzen()
static unsigned int __init shmobile_smp_get_core_count(void)
{
if (is_sh73a0())
return sh73a0_get_core_count();
if (is_r8a7779())
return r8a7779_get_core_count();
return 1;
}
static void __init shmobile_smp_prepare_cpus(void)
{
if (is_sh73a0())
sh73a0_smp_prepare_cpus();
if (is_r8a7779())
r8a7779_smp_prepare_cpus();
}
int shmobile_platform_cpu_kill(unsigned int cpu)
{
if (is_r8a7779())
return r8a7779_platform_cpu_kill(cpu);
return 1;
}
void __cpuinit platform_secondary_init(unsigned int cpu)
{
trace_hardirqs_off();
if (is_sh73a0())
sh73a0_secondary_init(cpu);
if (is_r8a7779())
r8a7779_secondary_init(cpu);
}
int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
{
if (is_sh73a0())
return sh73a0_boot_secondary(cpu);
if (is_r8a7779())
return r8a7779_boot_secondary(cpu);
return -ENOSYS;
}
void __init smp_init_cpus(void)
{
unsigned int ncores = shmobile_smp_get_core_count();
unsigned int i;
if (ncores > nr_cpu_ids) {
pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
ncores, nr_cpu_ids);
ncores = nr_cpu_ids;
}
for (i = 0; i < ncores; i++)
set_cpu_possible(i, true);
set_smp_cross_call(gic_raise_softirq);
}
void __init platform_smp_prepare_cpus(unsigned int max_cpus)
{
shmobile_smp_prepare_cpus();
}