arch/loongarch/kernel/env.c

Source file repositories/reference/linux-study-clean/arch/loongarch/kernel/env.c

File Facts

System
Linux kernel
Corpus path
arch/loongarch/kernel/env.c
Extension
.c
Size
2841 bytes
Lines
120
Domain
Architecture Layer
Bucket
arch/loongarch
Inferred role
Architecture Layer: exported/initcall integration point
Status
integration 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
/*
 * Author: Huacai Chen <chenhuacai@loongson.cn>
 *
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 */
#include <linux/acpi.h>
#include <linux/clk.h>
#include <linux/efi.h>
#include <linux/export.h>
#include <linux/memblock.h>
#include <linux/of_clk.h>
#include <asm/early_ioremap.h>
#include <asm/bootinfo.h>
#include <asm/loongson.h>
#include <asm/setup.h>
#include <asm/time.h>

u64 efi_system_table;
struct loongson_system_configuration loongson_sysconf;
EXPORT_SYMBOL(loongson_sysconf);

void __init init_environ(void)
{
	int efi_boot = fw_arg0;
	char *cmdline = early_memremap_ro(fw_arg1, COMMAND_LINE_SIZE);

	if (efi_boot)
		set_bit(EFI_BOOT, &efi.flags);
	else
		clear_bit(EFI_BOOT, &efi.flags);

	strscpy(boot_command_line, cmdline, COMMAND_LINE_SIZE);
	strscpy(init_command_line, cmdline, COMMAND_LINE_SIZE);
	early_memunmap(cmdline, COMMAND_LINE_SIZE);

	efi_system_table = fw_arg2;
}

static int __init init_cpu_fullname(void)
{
	int cpu, ret;
	char *cpuname;
	const char *model;

	/* Parsing cpuname from DTS model property */
	ret = of_property_read_string(of_root, "model", &model);
	if (ret == 0) {
		cpuname = kstrdup(model, GFP_KERNEL);
		if (!cpuname)
			return -ENOMEM;
		loongson_sysconf.cpuname = strsep(&cpuname, " ");
	}

	if (loongson_sysconf.cpuname && !strncmp(loongson_sysconf.cpuname, "Loongson", 8)) {
		for (cpu = 0; cpu < NR_CPUS; cpu++)
			__cpu_full_name[cpu] = loongson_sysconf.cpuname;
	}
	return 0;
}
arch_initcall(init_cpu_fullname);

static int __init fdt_cpu_clk_init(void)
{
	struct clk *clk;
	struct device_node *np;

	np = of_get_cpu_node(0, NULL);
	if (!np)
		return -ENODEV;

	clk = of_clk_get(np, 0);
	of_node_put(np);
	cpu_clock_freq = 200 * 1000 * 1000;

	if (IS_ERR(clk)) {
		pr_warn("No valid CPU clock freq, assume 200MHz.\n");
		return -ENODEV;
	}

	cpu_clock_freq = clk_get_rate(clk);
	clk_put(clk);

	return 0;
}
late_initcall(fdt_cpu_clk_init);

static ssize_t boardinfo_show(struct kobject *kobj,
			      struct kobj_attribute *attr, char *buf)
{

Annotation

Implementation Notes