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/*
* 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 <linux/of_address.h>
#include <linux/mbus.h>
#include <asm/cacheflush.h>
#include <asm/smp_plat.h>
#include "common.h"
#include "armada-370-xp.h"
#include "pmsu.h"
#include "coherency.h"
#define AXP_BOOTROM_BASE 0xfff00000
#define AXP_BOOTROM_SIZE 0x100000
static struct clk *__init get_cpu_clk(int cpu)
{
struct clk *cpu_clk;
struct device_node *np = of_get_cpu_node(cpu, NULL);
if (WARN(!np, "missing cpu node\n"))
return NULL;
cpu_clk = of_clk_get(np, 0);
if (WARN_ON(IS_ERR(cpu_clk)))
return NULL;
return cpu_clk;
}
static void __init set_secondary_cpus_clock(void)
{
int thiscpu, cpu;
unsigned long rate;
struct clk *cpu_clk;
thiscpu = smp_processor_id();
cpu_clk = get_cpu_clk(thiscpu);
if (!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_possible_cpu(cpu) {
if (cpu == thiscpu)
continue;
cpu_clk = get_cpu_clk(cpu);
if (!cpu_clk)
return;
clk_set_rate(cpu_clk, rate);
}
}
static int armada_xp_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
int ret, hw_cpu;
pr_info("Booting CPU %d\n", cpu);
hw_cpu = cpu_logical_map(cpu);
mvebu_pmsu_set_cpu_boot_addr(hw_cpu, armada_xp_secondary_startup);
/*
* This is needed to wake up CPUs in the offline state after
* using CPU hotplug.
*/
arch_send_wakeup_ipi_mask(cpumask_of(cpu));
/*
* This is needed to take secondary CPUs out of reset on the
* initial boot.
*/
ret = mvebu_cpu_reset_deassert(hw_cpu);
if (ret) {
pr_warn("unable to boot CPU: %d\n", ret);
return ret;
}
return 0;
}
/*
* When a CPU is brought back online, either through CPU hotplug, or
* because of the boot of a kexec'ed kernel, the PMSU configuration
* for this CPU might be in the deep idle state, preventing this CPU
* from receiving interrupts. Here, we therefore take out the current
* CPU from this state, which was entered by armada_xp_cpu_die()
* below.
*/
static void armada_xp_secondary_init(unsigned int cpu)
{
armada_370_xp_pmsu_idle_exit();
}
static void __init armada_xp_smp_init_cpus(void)
{
unsigned int ncores = num_possible_cpus();
if (ncores == 0 || ncores > ARMADA_XP_MAX_CPUS)
panic("Invalid number of CPUs in DT\n");
}
static void __init armada_xp_smp_prepare_cpus(unsigned int max_cpus)
{
struct device_node *node;
struct resource res;
int err;
set_secondary_cpus_clock();
flush_cache_all();
set_cpu_coherent();
/*
* In order to boot the secondary CPUs we need to ensure
* the bootROM is mapped at the correct address.
*/
node = of_find_compatible_node(NULL, NULL, "marvell,bootrom");
if (!node)
panic("Cannot find 'marvell,bootrom' compatible node");
err = of_address_to_resource(node, 0, &res);
if (err < 0)
panic("Cannot get 'bootrom' node address");
if (res.start != AXP_BOOTROM_BASE ||
resource_size(&res) != AXP_BOOTROM_SIZE)
panic("The address for the BootROM is incorrect");
}
#ifdef CONFIG_HOTPLUG_CPU
static void armada_xp_cpu_die(unsigned int cpu)
{
/*
* CPU hotplug is implemented by putting offline CPUs into the
* deep idle sleep state.
*/
armada_370_xp_pmsu_idle_enter(true);
}
/*
* We need a dummy function, so that platform_can_cpu_hotplug() knows
* we support CPU hotplug. However, the function does not need to do
* anything, because CPUs going offline can enter the deep idle state
* by themselves, without any help from a still alive CPU.
*/
static int armada_xp_cpu_kill(unsigned int cpu)
{
return 1;
}
#endif
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_boot_secondary = armada_xp_boot_secondary,
.smp_secondary_init = armada_xp_secondary_init,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = armada_xp_cpu_die,
.cpu_kill = armada_xp_cpu_kill,
#endif
};
CPU_METHOD_OF_DECLARE(armada_xp_smp, "marvell,armada-xp-smp",
&armada_xp_smp_ops);
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