arch/s390/kernel/facility.c

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

File Facts

System
Linux kernel
Corpus path
arch/s390/kernel/facility.c
Extension
.c
Size
347 bytes
Lines
23
Domain
Architecture Layer
Bucket
arch/s390
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
/*
 * Copyright IBM Corp. 2023
 */

#include <linux/export.h>
#include <asm/facility.h>

unsigned int stfle_size(void)
{
	static unsigned int size;
	unsigned int r;
	u64 dummy;

	r = READ_ONCE(size);
	if (!r) {
		r = __stfle_asm(&dummy, 1) + 1;
		WRITE_ONCE(size, r);
	}
	return r;
}
EXPORT_SYMBOL(stfle_size);

Annotation

Implementation Notes