linux/arch/arm/mach-mvebu/platsmp.c
Gregory CLEMENT 45f5984a8a arm: mvebu: Add SMP support for Armada XP
This enables SMP support on the Armada XP processor. It adds the
mandatory functions to support SMP such as: the SMP initialization
functions in platsmp.c, the secondary CPU entry point in headsmp.S and
the CPU hotplug initial support in hotplug.c.

Signed-off-by: Yehuda Yitschak <yehuday@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
2012-11-21 16:49:38 +01:00

123 lines
2.9 KiB
C

/*
* Symmetric Multi Processing (SMP) support for Armada XP
*
* Copyright (C) 2012 Marvell
*
* Lior Amsalem <alior@marvell.com>
* Yehuda Yitschak <yehuday@marvell.com>
* Gregory CLEMENT <gregory.clement@free-electrons.com>
* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*
* The Armada XP SoC has 4 ARMv7 PJ4B CPUs running in full HW coherency
* This file implements the routines for preparing the SMP infrastructure
* and waking up the secondary CPUs
*/
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <asm/cacheflush.h>
#include <asm/smp_plat.h>
#include "common.h"
#include "armada-370-xp.h"
#include "pmsu.h"
#include "coherency.h"
void __init set_secondary_cpus_clock(void)
{
int thiscpu;
unsigned long rate;
struct clk *cpu_clk = NULL;
struct device_node *np = NULL;
thiscpu = smp_processor_id();
for_each_node_by_type(np, "cpu") {
int err;
int cpu;
err = of_property_read_u32(np, "reg", &cpu);
if (WARN_ON(err))
return;
if (cpu == thiscpu) {
cpu_clk = of_clk_get(np, 0);
break;
}
}
if (WARN_ON(IS_ERR(cpu_clk)))
return;
clk_prepare_enable(cpu_clk);
rate = clk_get_rate(cpu_clk);
/* set all the other CPU clk to the same rate than the boot CPU */
for_each_node_by_type(np, "cpu") {
int err;
int cpu;
err = of_property_read_u32(np, "reg", &cpu);
if (WARN_ON(err))
return;
if (cpu != thiscpu) {
cpu_clk = of_clk_get(np, 0);
clk_set_rate(cpu_clk, rate);
}
}
}
static void __cpuinit armada_xp_secondary_init(unsigned int cpu)
{
armada_xp_mpic_smp_cpu_init();
}
static int __cpuinit armada_xp_boot_secondary(unsigned int cpu,
struct task_struct *idle)
{
pr_info("Booting CPU %d\n", cpu);
armada_xp_boot_cpu(cpu, armada_xp_secondary_startup);
return 0;
}
static void __init armada_xp_smp_init_cpus(void)
{
unsigned int i, ncores;
ncores = coherency_get_cpu_count();
/* Limit possible CPUs to defconfig */
if (ncores > nr_cpu_ids) {
pr_warn("SMP: %d CPUs physically present. Only %d configured.",
ncores, nr_cpu_ids);
pr_warn("Clipping CPU count to %d\n", nr_cpu_ids);
ncores = nr_cpu_ids;
}
for (i = 0; i < ncores; i++)
set_cpu_possible(i, true);
set_smp_cross_call(armada_mpic_send_doorbell);
}
void __init armada_xp_smp_prepare_cpus(unsigned int max_cpus)
{
set_secondary_cpus_clock();
flush_cache_all();
set_cpu_coherent(cpu_logical_map(smp_processor_id()), 0);
}
struct smp_operations armada_xp_smp_ops __initdata = {
.smp_init_cpus = armada_xp_smp_init_cpus,
.smp_prepare_cpus = armada_xp_smp_prepare_cpus,
.smp_secondary_init = armada_xp_secondary_init,
.smp_boot_secondary = armada_xp_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = armada_xp_cpu_die,
#endif
};