arch/arm64/include/asm/io.h

Source file repositories/reference/linux-study-clean/arch/arm64/include/asm/io.h

File Facts

System
Linux kernel
Corpus path
arch/arm64/include/asm/io.h
Extension
.h
Size
9737 bytes
Lines
337
Domain
Architecture Layer
Bucket
arch/arm64
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

#ifndef __ASM_IO_H
#define __ASM_IO_H

#include <linux/types.h>
#include <linux/pgtable.h>

#include <asm/byteorder.h>
#include <asm/barrier.h>
#include <asm/memory.h>
#include <asm/early_ioremap.h>
#include <asm/alternative.h>
#include <asm/cpufeature.h>
#include <asm/rsi.h>

/*
 * Generic IO read/write.  These perform native-endian accesses.
 */
#define __raw_writeb __raw_writeb
static __always_inline void __raw_writeb(u8 val, volatile void __iomem *addr)
{
	volatile u8 __iomem *ptr = addr;
	asm volatile("strb %w0, %1" : : "rZ" (val), "Qo" (*ptr));
}

#define __raw_writew __raw_writew
static __always_inline void __raw_writew(u16 val, volatile void __iomem *addr)
{
	volatile u16 __iomem *ptr = addr;
	asm volatile("strh %w0, %1" : : "rZ" (val), "Qo" (*ptr));
}

#define __raw_writel __raw_writel
static __always_inline void __raw_writel(u32 val, volatile void __iomem *addr)
{
	volatile u32 __iomem *ptr = addr;
	asm volatile("str %w0, %1" : : "rZ" (val), "Qo" (*ptr));
}

#define __raw_writeq __raw_writeq
static __always_inline void __raw_writeq(u64 val, volatile void __iomem *addr)
{
	volatile u64 __iomem *ptr = addr;
	asm volatile("str %x0, %1" : : "rZ" (val), "Qo" (*ptr));
}

#define __raw_readb __raw_readb
static __always_inline u8 __raw_readb(const volatile void __iomem *addr)
{
	u8 val;
	asm volatile(ALTERNATIVE("ldrb %w0, [%1]",
				 "ldarb %w0, [%1]",
				 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
		     : "=r" (val) : "r" (addr));
	return val;
}

#define __raw_readw __raw_readw
static __always_inline u16 __raw_readw(const volatile void __iomem *addr)
{
	u16 val;

	asm volatile(ALTERNATIVE("ldrh %w0, [%1]",
				 "ldarh %w0, [%1]",
				 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
		     : "=r" (val) : "r" (addr));
	return val;
}

#define __raw_readl __raw_readl
static __always_inline u32 __raw_readl(const volatile void __iomem *addr)
{
	u32 val;
	asm volatile(ALTERNATIVE("ldr %w0, [%1]",
				 "ldar %w0, [%1]",
				 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
		     : "=r" (val) : "r" (addr));
	return val;
}

#define __raw_readq __raw_readq
static __always_inline u64 __raw_readq(const volatile void __iomem *addr)
{
	u64 val;
	asm volatile(ALTERNATIVE("ldr %0, [%1]",
				 "ldar %0, [%1]",
				 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
		     : "=r" (val) : "r" (addr));
	return val;
}

Annotation

Implementation Notes