arch/s390/kernel/vdso/getcpu.c

Source file repositories/reference/linux-study-clean/arch/s390/kernel/vdso/getcpu.c

File Facts

System
Linux kernel
Corpus path
arch/s390/kernel/vdso/getcpu.c
Extension
.c
Size
426 bytes
Lines
21
Domain
Architecture Layer
Bucket
arch/s390
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
/* Copyright IBM Corp. 2020 */

#include <linux/compiler.h>
#include <asm/timex.h>
#include "vdso.h"

int __s390_vdso_getcpu(unsigned *cpu, unsigned *node, void *unused)
{
	union tod_clock clk;

	/* CPU number is stored in the programmable field of the TOD clock */
	store_tod_clock_ext(&clk);
	if (cpu)
		*cpu = clk.pf;
	/* NUMA node is always zero */
	if (node)
		*node = 0;
	return 0;
}

Annotation

Implementation Notes