arch/powerpc/kernel/io.c

Source file repositories/reference/linux-study-clean/arch/powerpc/kernel/io.c

File Facts

System
Linux kernel
Corpus path
arch/powerpc/kernel/io.c
Extension
.c
Size
3779 bytes
Lines
213
Domain
Architecture Layer
Bucket
arch/powerpc
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-or-later
/*
 * I/O string operations
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *    Copyright (C) 2006 IBM Corporation
 *
 * Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
 * and Paul Mackerras.
 *
 * Adapted for iSeries by Mike Corrigan (mikejc@us.ibm.com)
 * PPC64 updates by Dave Engebretsen (engebret@us.ibm.com)
 *
 * Rewritten in C by Stephen Rothwell.
 */
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/compiler.h>
#include <linux/export.h>

#include <asm/io.h>
#include <asm/firmware.h>
#include <asm/bug.h>

/* See definition in io.h */
bool isa_io_special;

void _insb(const volatile u8 __iomem *port, void *buf, long count)
{
	u8 *tbuf = buf;
	u8 tmp;

	if (unlikely(count <= 0))
		return;

	mb();
	do {
		tmp = *(const volatile u8 __force *)port;
		eieio();
		*tbuf++ = tmp;
	} while (--count != 0);
	data_barrier(tmp);
}
EXPORT_SYMBOL(_insb);

void _outsb(volatile u8 __iomem *port, const void *buf, long count)
{
	const u8 *tbuf = buf;

	if (unlikely(count <= 0))
		return;

	mb();
	do {
		*(volatile u8 __force *)port = *tbuf++;
	} while (--count != 0);
	mb();
}
EXPORT_SYMBOL(_outsb);

void _insw(const volatile u16 __iomem *port, void *buf, long count)
{
	u16 *tbuf = buf;
	u16 tmp;

	if (unlikely(count <= 0))
		return;

	mb();
	do {
		tmp = *(const volatile u16 __force *)port;
		eieio();
		*tbuf++ = tmp;
	} while (--count != 0);
	data_barrier(tmp);
}
EXPORT_SYMBOL(_insw);

void _outsw(volatile u16 __iomem *port, const void *buf, long count)
{
	const u16 *tbuf = buf;

	if (unlikely(count <= 0))
		return;

	mb();
	do {
		*(volatile u16 __force *)port = *tbuf++;
	} while (--count != 0);
	mb();
}

Annotation

Implementation Notes