arch/nios2/kernel/cpuinfo.c

Source file repositories/reference/linux-study-clean/arch/nios2/kernel/cpuinfo.c

File Facts

System
Linux kernel
Corpus path
arch/nios2/kernel/cpuinfo.c
Extension
.c
Size
5482 bytes
Lines
193
Domain
Architecture Layer
Bucket
arch/nios2
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-or-later
/*
 * Copyright (C) 2013 Altera Corporation
 * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
 *
 * Based on cpuinfo.c from microblaze
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/seq_file.h>
#include <linux/string.h>
#include <linux/of.h>
#include <asm/cpuinfo.h>

struct cpuinfo cpuinfo;

#define err_cpu(x) \
	pr_err("ERROR: Nios II " x " different for kernel and DTS\n")

static inline u32 fcpu(struct device_node *cpu, const char *n)
{
	u32 val = 0;

	of_property_read_u32(cpu, n, &val);

	return val;
}

void __init setup_cpuinfo(void)
{
	struct device_node *cpu;
	const char *str;
	int len;

	cpu = of_get_cpu_node(0, NULL);
	if (!cpu)
		panic("%s: No CPU found in devicetree!\n", __func__);

	if (!of_property_read_bool(cpu, "altr,has-initda"))
		panic("initda instruction is unimplemented. Please update your "
			"hardware system to have more than 4-byte line data "
			"cache\n");

	cpuinfo.cpu_clock_freq = fcpu(cpu, "clock-frequency");

	str = of_get_property(cpu, "altr,implementation", &len);
	strscpy(cpuinfo.cpu_impl, str ?: "<unknown>");

	cpuinfo.has_div = of_property_read_bool(cpu, "altr,has-div");
	cpuinfo.has_mul = of_property_read_bool(cpu, "altr,has-mul");
	cpuinfo.has_mulx = of_property_read_bool(cpu, "altr,has-mulx");
	cpuinfo.has_bmx = of_property_read_bool(cpu, "altr,has-bmx");
	cpuinfo.has_cdx = of_property_read_bool(cpu, "altr,has-cdx");
	cpuinfo.mmu = of_property_read_bool(cpu, "altr,has-mmu");

	if (IS_ENABLED(CONFIG_NIOS2_HW_DIV_SUPPORT) && !cpuinfo.has_div)
		err_cpu("DIV");

	if (IS_ENABLED(CONFIG_NIOS2_HW_MUL_SUPPORT) && !cpuinfo.has_mul)
		err_cpu("MUL");

	if (IS_ENABLED(CONFIG_NIOS2_HW_MULX_SUPPORT) && !cpuinfo.has_mulx)
		err_cpu("MULX");

	if (IS_ENABLED(CONFIG_NIOS2_BMX_SUPPORT) && !cpuinfo.has_bmx)
		err_cpu("BMX");

	if (IS_ENABLED(CONFIG_NIOS2_CDX_SUPPORT) && !cpuinfo.has_cdx)
		err_cpu("CDX");

	cpuinfo.tlb_num_ways = fcpu(cpu, "altr,tlb-num-ways");
	if (!cpuinfo.tlb_num_ways)
		panic("altr,tlb-num-ways can't be 0. Please check your hardware "
			"system\n");
	cpuinfo.icache_line_size = fcpu(cpu, "icache-line-size");
	cpuinfo.icache_size = fcpu(cpu, "icache-size");
	if (CONFIG_NIOS2_ICACHE_SIZE != cpuinfo.icache_size)
		pr_warn("Warning: icache size configuration mismatch "
		"(0x%x vs 0x%x) of CONFIG_NIOS2_ICACHE_SIZE vs "
		"device tree icache-size\n",
		CONFIG_NIOS2_ICACHE_SIZE, cpuinfo.icache_size);

	cpuinfo.dcache_line_size = fcpu(cpu, "dcache-line-size");
	if (CONFIG_NIOS2_DCACHE_LINE_SIZE != cpuinfo.dcache_line_size)
		pr_warn("Warning: dcache line size configuration mismatch "
		"(0x%x vs 0x%x) of CONFIG_NIOS2_DCACHE_LINE_SIZE vs "
		"device tree dcache-line-size\n",
		CONFIG_NIOS2_DCACHE_LINE_SIZE, cpuinfo.dcache_line_size);

Annotation

Implementation Notes