Staging
v0.7.0
v0.7.0
https://github.com/torvalds/linux
Tip revision: 5d0c230f1de8c7515b6567d9afba1f196fb4e2f4 authored by Linus Torvalds on 30 July 2023, 20:23:47 UTC
Linux 6.5-rc4
Linux 6.5-rc4
Tip revision: 5d0c230
platsmp.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2010-2011 Calxeda, Inc.
* Copyright 2012 Pavel Machek <pavel@denx.de>
* Based on platsmp.c, Copyright (C) 2002 ARM Ltd.
* Copyright (C) 2012 Altera Corporation
*/
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <asm/cacheflush.h>
#include <asm/smp_scu.h>
#include <asm/smp_plat.h>
#include "core.h"
static int socfpga_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
int trampoline_size = secondary_trampoline_end - secondary_trampoline;
if (socfpga_cpu1start_addr) {
/* This will put CPU #1 into reset. */
writel(RSTMGR_MPUMODRST_CPU1,
rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST);
memcpy(phys_to_virt(0), secondary_trampoline, trampoline_size);
writel(__pa_symbol(secondary_startup),
sys_manager_base_addr + (socfpga_cpu1start_addr & 0x000000ff));
flush_cache_all();
smp_wmb();
outer_clean_range(0, trampoline_size);
/* This will release CPU #1 out of reset. */
writel(0, rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST);
}
return 0;
}
static int socfpga_a10_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
int trampoline_size = secondary_trampoline_end - secondary_trampoline;
if (socfpga_cpu1start_addr) {
writel(RSTMGR_MPUMODRST_CPU1, rst_manager_base_addr +
SOCFPGA_A10_RSTMGR_MODMPURST);
memcpy(phys_to_virt(0), secondary_trampoline, trampoline_size);
writel(__pa_symbol(secondary_startup),
sys_manager_base_addr + (socfpga_cpu1start_addr & 0x00000fff));
flush_cache_all();
smp_wmb();
outer_clean_range(0, trampoline_size);
/* This will release CPU #1 out of reset. */
writel(0, rst_manager_base_addr + SOCFPGA_A10_RSTMGR_MODMPURST);
}
return 0;
}
static void __init socfpga_smp_prepare_cpus(unsigned int max_cpus)
{
struct device_node *np;
void __iomem *socfpga_scu_base_addr;
np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
if (!np) {
pr_err("%s: missing scu\n", __func__);
return;
}
socfpga_scu_base_addr = of_iomap(np, 0);
if (!socfpga_scu_base_addr)
return;
scu_enable(socfpga_scu_base_addr);
}
#ifdef CONFIG_HOTPLUG_CPU
/*
* platform-specific code to shutdown a CPU
*
* Called with IRQs disabled
*/
static void socfpga_cpu_die(unsigned int cpu)
{
/* Do WFI. If we wake up early, go back into WFI */
while (1)
cpu_do_idle();
}
/*
* 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 just do WFI. We could reset
* the CPUs but it would increase power consumption.
*/
static int socfpga_cpu_kill(unsigned int cpu)
{
return 1;
}
#endif
static const struct smp_operations socfpga_smp_ops __initconst = {
.smp_prepare_cpus = socfpga_smp_prepare_cpus,
.smp_boot_secondary = socfpga_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = socfpga_cpu_die,
.cpu_kill = socfpga_cpu_kill,
#endif
};
static const struct smp_operations socfpga_a10_smp_ops __initconst = {
.smp_prepare_cpus = socfpga_smp_prepare_cpus,
.smp_boot_secondary = socfpga_a10_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = socfpga_cpu_die,
.cpu_kill = socfpga_cpu_kill,
#endif
};
CPU_METHOD_OF_DECLARE(socfpga_smp, "altr,socfpga-smp", &socfpga_smp_ops);
CPU_METHOD_OF_DECLARE(socfpga_a10_smp, "altr,socfpga-a10-smp", &socfpga_a10_smp_ops);