linux-stable/arch/arm/mach-vexpress/platsmp.c
Pawel Moll d2606f81d5 ARM: vexpress: Simplify SMP operations for DT-powered system
As all cores must be properly described in the Device Tree,
there is no point in getting their numbers from SCU on
A5/A9 platforms. This significantly simplifies the code,
removing the need for flat-tree scanning and early static
mapping.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
2014-05-15 17:02:21 +01:00

116 lines
3 KiB
C

/*
* linux/arch/arm/mach-vexpress/platsmp.c
*
* 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/smp.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/vexpress.h>
#include <asm/mcpm.h>
#include <asm/smp_scu.h>
#include <asm/mach/map.h>
#include <mach/motherboard.h>
#include <plat/platsmp.h>
#include "core.h"
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system.
*/
static void __init vexpress_smp_init_cpus(void)
{
ct_desc->init_cpu_map();
}
static void __init vexpress_smp_prepare_cpus(unsigned int max_cpus)
{
/*
* Initialise the present map, which describes the set of CPUs
* actually populated at the present time.
*/
ct_desc->smp_enable(max_cpus);
/*
* Write the address of secondary startup into the
* system-wide flags register. The boot monitor waits
* until it receives a soft interrupt, and then the
* secondary CPU branches to this address.
*/
vexpress_flags_set(virt_to_phys(versatile_secondary_startup));
}
struct smp_operations __initdata vexpress_smp_ops = {
.smp_init_cpus = vexpress_smp_init_cpus,
.smp_prepare_cpus = vexpress_smp_prepare_cpus,
.smp_secondary_init = versatile_secondary_init,
.smp_boot_secondary = versatile_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = vexpress_cpu_die,
#endif
};
bool __init vexpress_smp_init_ops(void)
{
#ifdef CONFIG_MCPM
/*
* The best way to detect a multi-cluster configuration at the moment
* is to look for the presence of a CCI in the system.
* Override the default vexpress_smp_ops if so.
*/
struct device_node *node;
node = of_find_compatible_node(NULL, NULL, "arm,cci-400");
if (node && of_device_is_available(node)) {
mcpm_smp_set_ops();
return true;
}
#endif
return false;
}
#if defined(CONFIG_OF)
static const struct of_device_id vexpress_smp_dt_scu_match[] __initconst = {
{ .compatible = "arm,cortex-a5-scu", },
{ .compatible = "arm,cortex-a9-scu", },
{}
};
static void __init vexpress_smp_dt_prepare_cpus(unsigned int max_cpus)
{
struct device_node *scu = of_find_matching_node(NULL,
vexpress_smp_dt_scu_match);
if (scu)
scu_enable(of_iomap(scu, 0));
/*
* Write the address of secondary startup into the
* system-wide flags register. The boot monitor waits
* until it receives a soft interrupt, and then the
* secondary CPU branches to this address.
*/
vexpress_flags_set(virt_to_phys(versatile_secondary_startup));
}
struct smp_operations __initdata vexpress_smp_dt_ops = {
.smp_prepare_cpus = vexpress_smp_dt_prepare_cpus,
.smp_secondary_init = versatile_secondary_init,
.smp_boot_secondary = versatile_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = vexpress_cpu_die,
#endif
};
#endif