arch/arm/mach-shmobile/smp-r8a7779.c

Source file repositories/reference/linux-study-clean/arch/arm/mach-shmobile/smp-r8a7779.c

File Facts

System
Linux kernel
Corpus path
arch/arm/mach-shmobile/smp-r8a7779.c
Extension
.c
Size
1930 bytes
Lines
88
Domain
Architecture Layer
Bucket
arch/arm
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * SMP support for R-Mobile / SH-Mobile - r8a7779 portion
 *
 * Copyright (C) 2011  Renesas Solutions Corp.
 * Copyright (C) 2011  Magnus Damm
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/soc/renesas/rcar-sysc.h>

#include <asm/cacheflush.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>

#include "common.h"
#include "r8a7779.h"

#define HPBREG_BASE		0xfe700000
#define AVECR			0x0040	/* ARM Reset Vector Address Register */

#define R8A7779_SCU_BASE	0xf0000000

static int r8a7779_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
	int ret = -EIO;

	cpu = cpu_logical_map(cpu);
	if (cpu)
		ret = rcar_sysc_power_up_cpu(cpu);

	return ret;
}

static void __init r8a7779_smp_prepare_cpus(unsigned int max_cpus)
{
	void __iomem *base;

	if (!request_mem_region(0, SZ_4K, "Boot Area")) {
		pr_err("Failed to request boot area\n");
		return;
	}

	base = ioremap(HPBREG_BASE, 0x1000);

	/* Map the reset vector (in headsmp-scu.S, headsmp.S) */
	writel(__pa(shmobile_boot_vector), base + AVECR);

	/* setup r8a7779 specific SCU bits */
	shmobile_smp_scu_prepare_cpus(R8A7779_SCU_BASE, max_cpus);

	iounmap(base);
}

#ifdef CONFIG_HOTPLUG_CPU
static int r8a7779_platform_cpu_kill(unsigned int cpu)
{
	int ret = -EIO;

	cpu = cpu_logical_map(cpu);
	if (cpu)
		ret = rcar_sysc_power_down_cpu(cpu);

	return ret ? ret : 1;
}

static int r8a7779_cpu_kill(unsigned int cpu)
{
	if (shmobile_smp_scu_cpu_kill(cpu))
		return r8a7779_platform_cpu_kill(cpu);

	return 0;
}
#endif /* CONFIG_HOTPLUG_CPU */

const struct smp_operations r8a7779_smp_ops  __initconst = {
	.smp_prepare_cpus	= r8a7779_smp_prepare_cpus,
	.smp_boot_secondary	= r8a7779_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
	.cpu_die		= shmobile_smp_scu_cpu_die,
	.cpu_kill		= r8a7779_cpu_kill,
#endif
};

Annotation

Implementation Notes