arch/mips/include/asm/local.h

Source file repositories/reference/linux-study-clean/arch/mips/include/asm/local.h

File Facts

System
Linux kernel
Corpus path
arch/mips/include/asm/local.h
Extension
.h
Size
4822 bytes
Lines
190
Domain
Architecture Layer
Bucket
arch/mips
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 _ARCH_MIPS_LOCAL_H
#define _ARCH_MIPS_LOCAL_H

#include <linux/percpu.h>
#include <linux/bitops.h>
#include <linux/atomic.h>
#include <asm/asm.h>
#include <asm/cmpxchg.h>
#include <asm/compiler.h>

typedef struct
{
	atomic_long_t a;
} local_t;

#define LOCAL_INIT(i)	{ ATOMIC_LONG_INIT(i) }

#define local_read(l)	atomic_long_read(&(l)->a)
#define local_set(l, i) atomic_long_set(&(l)->a, (i))

#define local_add(i, l) atomic_long_add((i), (&(l)->a))
#define local_sub(i, l) atomic_long_sub((i), (&(l)->a))
#define local_inc(l)	atomic_long_inc(&(l)->a)
#define local_dec(l)	atomic_long_dec(&(l)->a)

/*
 * Same as above, but return the result value
 */
static __inline__ long local_add_return(long i, local_t * l)
{
	unsigned long result;

	if (kernel_uses_llsc) {
		unsigned long temp;

		__asm__ __volatile__(
		"	.set	push					\n"
		"	.set	"MIPS_ISA_ARCH_LEVEL"			\n"
			__SYNC(full, loongson3_war) "                   \n"
		"1:"	__stringify(LONG_LL)	"	%1, %2		\n"
			__stringify(LONG_ADDU)	"	%0, %1, %3	\n"
			__stringify(LONG_SC)	"	%0, %2		\n"
			__stringify(SC_BEQZ)	"	%0, 1b		\n"
			__stringify(LONG_ADDU)	"	%0, %1, %3	\n"
		"	.set	pop					\n"
		: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
		: "Ir" (i), "m" (l->a.counter)
		: "memory");
	} else {
		unsigned long flags;

		local_irq_save(flags);
		result = l->a.counter;
		result += i;
		l->a.counter = result;
		local_irq_restore(flags);
	}

	return result;
}

static __inline__ long local_sub_return(long i, local_t * l)
{
	unsigned long result;

	if (kernel_uses_llsc) {
		unsigned long temp;

		__asm__ __volatile__(
		"	.set	push					\n"
		"	.set	"MIPS_ISA_ARCH_LEVEL"			\n"
			__SYNC(full, loongson3_war) "                   \n"
		"1:"	__stringify(LONG_LL)	"	%1, %2		\n"
			__stringify(LONG_SUBU)	"	%0, %1, %3	\n"
			__stringify(LONG_SUBU)	"	%0, %1, %3	\n"
			__stringify(LONG_SC)	"	%0, %2		\n"
			__stringify(SC_BEQZ)	"	%0, 1b		\n"
			__stringify(LONG_SUBU)	"	%0, %1, %3	\n"
		"	.set	pop					\n"
		: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
		: "Ir" (i), "m" (l->a.counter)
		: "memory");
	} else {
		unsigned long flags;

		local_irq_save(flags);
		result = l->a.counter;
		result -= i;
		l->a.counter = result;
		local_irq_restore(flags);

Annotation

Implementation Notes