linux_dsm_epyc7002/arch/arm/mach-vexpress/platsmp.c
Russell King 4fb68e12f2 ARM: vexpress/realview: consolidate immitation CPU hotplug
The only difference between the hotplug implementation for Realview
and Versatile Express are the bit in the auxiliary control register
to disable coherency.  Combine the two implentations accounting for
that difference.

Rename the functions to try to discourage cargo-cult copying of this
code.

Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-12-14 14:44:59 +00:00

100 lines
2.4 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 <plat/platsmp.h>
#include "core.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
};