https://github.com/torvalds/linux
Tip revision: c9c3395d5e3dcc6daee66c6908354d47bf98cb0c authored by Linus Torvalds on 19 February 2023, 22:24:22 UTC
Linux 6.2
Linux 6.2
Tip revision: c9c3395
platsmp-vexpress.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2002 ARM Ltd.
* All Rights Reserved
*/
#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 "platsmp.h"
#include "vexpress.h"
bool __init vexpress_smp_init_ops(void)
{
#ifdef CONFIG_MCPM
int cpu;
struct device_node *cpu_node, *cci_node;
/*
* The best way to detect a multi-cluster configuration
* is to detect if the kernel can take over CCI ports
* control. Loop over possible CPUs and check if CCI
* port control is available.
* Override the default vexpress_smp_ops if so.
*/
for_each_possible_cpu(cpu) {
bool available;
cpu_node = of_get_cpu_node(cpu, NULL);
if (WARN(!cpu_node, "Missing cpu device node!"))
return false;
cci_node = of_parse_phandle(cpu_node, "cci-control-port", 0);
available = cci_node && of_device_is_available(cci_node);
of_node_put(cci_node);
of_node_put(cpu_node);
if (!available)
return false;
}
mcpm_smp_set_ops();
return true;
#else
return false;
#endif
}
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(__pa_symbol(versatile_secondary_startup));
}
#ifdef CONFIG_HOTPLUG_CPU
static void vexpress_cpu_die(unsigned int cpu)
{
versatile_immitation_cpu_die(cpu, 0x40);
}
#endif
const struct smp_operations vexpress_smp_dt_ops __initconst = {
.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
};