arch/loongarch/include/asm/local.h

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

File Facts

System
Linux kernel
Corpus path
arch/loongarch/include/asm/local.h
Extension
.h
Size
5041 bytes
Lines
189
Domain
Architecture Layer
Bucket
arch/loongarch
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_LOONGARCH_LOCAL_H
#define _ARCH_LOONGARCH_LOCAL_H

#include <linux/percpu.h>
#include <linux/bitops.h>
#include <linux/atomic.h>
#include <asm/asm.h>
#include <asm/cmpxchg.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
 */
#ifdef CONFIG_CPU_HAS_AMO
static inline long local_add_return(long i, local_t *l)
{
	unsigned long result;

	__asm__ __volatile__(
	"   " __AMADD " %1, %2, %0      \n"
	: "+ZB" (l->a.counter), "=&r" (result)
	: "r" (i)
	: "memory");
	result = result + i;

	return result;
}

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

	__asm__ __volatile__(
	"   " __AMADD "%1, %2, %0       \n"
	: "+ZB" (l->a.counter), "=&r" (result)
	: "r" (-i)
	: "memory");

	result = result - i;

	return result;
}
#else
static inline long local_add_return(long i, local_t *l)
{
        unsigned long result, temp;

        __asm__ __volatile__(
        "1:"    __LL    "%1, %2         # local_add_return      \n"
        __stringify(LONG_ADD) "   %0, %1, %3                    \n"
                __SC    "%0, %2                                 \n"
        "       beq     %0, $r0, 1b                             \n"
        __stringify(LONG_ADD) "   %0, %1, %3                    \n"
        : "=&r" (result), "=&r" (temp), "=ZC" (l->a.counter)
        : "r" (i), "ZC" (l->a.counter)
        : "memory");

        return result;
}

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

        __asm__ __volatile__(
        "1:"    __LL    "%1, %2         # local_sub_return      \n"
        __stringify(LONG_SUB) "   %0, %1, %3                    \n"
                __SC    "%0, %2                                 \n"
        "       beq     %0, $r0, 1b                             \n"
	__stringify(LONG_SUB) "   %0, %1, %3                    \n"
        : "=&r" (result), "=&r" (temp), "=ZC" (l->a.counter)
        : "r" (i), "ZC" (l->a.counter)
        : "memory");

        return result;
}
#endif

Annotation

Implementation Notes