arch/arm/include/asm/bitops.h

Source file repositories/reference/linux-study-clean/arch/arm/include/asm/bitops.h

File Facts

System
Linux kernel
Corpus path
arch/arm/include/asm/bitops.h
Extension
.h
Size
7732 bytes
Lines
279
Domain
Architecture Layer
Bucket
arch/arm
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_ARM_BITOPS_H
#define __ASM_ARM_BITOPS_H

#ifdef __KERNEL__

#ifndef _LINUX_BITOPS_H
#error only <linux/bitops.h> can be included directly
#endif

#include <linux/compiler.h>
#include <linux/irqflags.h>
#include <asm/barrier.h>

/*
 * These functions are the basis of our bit ops.
 *
 * First, the atomic bitops. These use native endian.
 */
static inline void ____atomic_set_bit(unsigned int bit, volatile unsigned long *p)
{
	unsigned long flags;
	unsigned long mask = BIT_MASK(bit);

	p += BIT_WORD(bit);

	raw_local_irq_save(flags);
	*p |= mask;
	raw_local_irq_restore(flags);
}

static inline void ____atomic_clear_bit(unsigned int bit, volatile unsigned long *p)
{
	unsigned long flags;
	unsigned long mask = BIT_MASK(bit);

	p += BIT_WORD(bit);

	raw_local_irq_save(flags);
	*p &= ~mask;
	raw_local_irq_restore(flags);
}

static inline void ____atomic_change_bit(unsigned int bit, volatile unsigned long *p)
{
	unsigned long flags;
	unsigned long mask = BIT_MASK(bit);

	p += BIT_WORD(bit);

	raw_local_irq_save(flags);
	*p ^= mask;
	raw_local_irq_restore(flags);
}

static inline int
____atomic_test_and_set_bit(unsigned int bit, volatile unsigned long *p)
{
	unsigned long flags;
	unsigned int res;
	unsigned long mask = BIT_MASK(bit);

	p += BIT_WORD(bit);

	raw_local_irq_save(flags);
	res = *p;
	*p = res | mask;
	raw_local_irq_restore(flags);

	return (res & mask) != 0;
}

static inline int
____atomic_test_and_clear_bit(unsigned int bit, volatile unsigned long *p)
{
	unsigned long flags;
	unsigned int res;
	unsigned long mask = BIT_MASK(bit);

	p += BIT_WORD(bit);

	raw_local_irq_save(flags);
	res = *p;
	*p = res & ~mask;
	raw_local_irq_restore(flags);

	return (res & mask) != 0;
}

static inline int
____atomic_test_and_change_bit(unsigned int bit, volatile unsigned long *p)

Annotation

Implementation Notes