115 строки
3.3 KiB
C
115 строки
3.3 KiB
C
/*
|
|
* Symmetric Multi Processing (SMP) support for Marvell EBU Cortex-A9
|
|
* based SOCs (Armada 375/38x).
|
|
*
|
|
* Copyright (C) 2014 Marvell
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/io.h>
|
|
#include <linux/of.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/mbus.h>
|
|
#include <asm/smp_scu.h>
|
|
#include <asm/smp_plat.h>
|
|
#include "common.h"
|
|
#include "pmsu.h"
|
|
|
|
extern void mvebu_cortex_a9_secondary_startup(void);
|
|
|
|
static int mvebu_cortex_a9_boot_secondary(unsigned int cpu,
|
|
struct task_struct *idle)
|
|
{
|
|
int ret, hw_cpu;
|
|
|
|
pr_info("Booting CPU %d\n", cpu);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
hw_cpu = cpu_logical_map(cpu);
|
|
if (of_machine_is_compatible("marvell,armada375"))
|
|
mvebu_system_controller_set_cpu_boot_addr(mvebu_cortex_a9_secondary_startup);
|
|
else
|
|
mvebu_pmsu_set_cpu_boot_addr(hw_cpu, mvebu_cortex_a9_secondary_startup);
|
|
smp_wmb();
|
|
|
|
/*
|
|
* Doing this before deasserting the CPUs is needed to wake up CPUs
|
|
* in the offline state after using CPU hotplug.
|
|
*/
|
|
arch_send_wakeup_ipi_mask(cpumask_of(cpu));
|
|
|
|
ret = mvebu_cpu_reset_deassert(hw_cpu);
|
|
if (ret) {
|
|
pr_err("Could not start the secondary 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_38x_cpu_die()
|
|
* below.
|
|
*/
|
|
static void armada_38x_secondary_init(unsigned int cpu)
|
|
{
|
|
mvebu_v7_pmsu_idle_exit();
|
|
}
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
static void armada_38x_cpu_die(unsigned int cpu)
|
|
{
|
|
/*
|
|
* CPU hotplug is implemented by putting offline CPUs into the
|
|
* deep idle sleep state.
|
|
*/
|
|
armada_38x_do_cpu_suspend(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_38x_cpu_kill(unsigned int cpu)
|
|
{
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
static const struct smp_operations mvebu_cortex_a9_smp_ops __initconst = {
|
|
.smp_boot_secondary = mvebu_cortex_a9_boot_secondary,
|
|
};
|
|
|
|
static const struct smp_operations armada_38x_smp_ops __initconst = {
|
|
.smp_boot_secondary = mvebu_cortex_a9_boot_secondary,
|
|
.smp_secondary_init = armada_38x_secondary_init,
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
.cpu_die = armada_38x_cpu_die,
|
|
.cpu_kill = armada_38x_cpu_kill,
|
|
#endif
|
|
};
|
|
|
|
CPU_METHOD_OF_DECLARE(mvebu_armada_375_smp, "marvell,armada-375-smp",
|
|
&mvebu_cortex_a9_smp_ops);
|
|
CPU_METHOD_OF_DECLARE(mvebu_armada_380_smp, "marvell,armada-380-smp",
|
|
&armada_38x_smp_ops);
|
|
CPU_METHOD_OF_DECLARE(mvebu_armada_390_smp, "marvell,armada-390-smp",
|
|
&armada_38x_smp_ops);
|