mirror of
https://github.com/smaeul/u-boot.git
synced 2025-10-30 19:48:19 +00:00
b551173b73
Add a subset of this header file from Linux 4.0 to support atomic operations in U-Boot. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
116 lines
2.4 KiB
C
116 lines
2.4 KiB
C
#ifndef _ASM_X86_ATOMIC_H
|
|
#define _ASM_X86_ATOMIC_H
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/types.h>
|
|
#include <asm/processor.h>
|
|
|
|
typedef struct { volatile int counter; } atomic_t;
|
|
|
|
/*
|
|
* Atomic operations that C can't guarantee us. Useful for
|
|
* resource counting etc..
|
|
*/
|
|
|
|
#define ATOMIC_INIT(i) { (i) }
|
|
|
|
/**
|
|
* atomic_read - read atomic variable
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically reads the value of @v.
|
|
*/
|
|
static inline int atomic_read(const atomic_t *v)
|
|
{
|
|
return ACCESS_ONCE((v)->counter);
|
|
}
|
|
|
|
/**
|
|
* atomic_set - set atomic variable
|
|
* @v: pointer of type atomic_t
|
|
* @i: required value
|
|
*
|
|
* Atomically sets the value of @v to @i.
|
|
*/
|
|
static inline void atomic_set(atomic_t *v, int i)
|
|
{
|
|
v->counter = i;
|
|
}
|
|
|
|
/**
|
|
* atomic_add - add integer to atomic variable
|
|
* @i: integer value to add
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically adds @i to @v.
|
|
*/
|
|
static inline void atomic_add(int i, atomic_t *v)
|
|
{
|
|
asm volatile(LOCK_PREFIX "addl %1,%0"
|
|
: "+m" (v->counter)
|
|
: "ir" (i));
|
|
}
|
|
|
|
/**
|
|
* atomic_sub - subtract integer from atomic variable
|
|
* @i: integer value to subtract
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically subtracts @i from @v.
|
|
*/
|
|
static inline void atomic_sub(int i, atomic_t *v)
|
|
{
|
|
asm volatile(LOCK_PREFIX "subl %1,%0"
|
|
: "+m" (v->counter)
|
|
: "ir" (i));
|
|
}
|
|
|
|
/**
|
|
* atomic_inc - increment atomic variable
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically increments @v by 1.
|
|
*/
|
|
static inline void atomic_inc(atomic_t *v)
|
|
{
|
|
asm volatile(LOCK_PREFIX "incl %0"
|
|
: "+m" (v->counter));
|
|
}
|
|
|
|
/**
|
|
* atomic_dec - decrement atomic variable
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically decrements @v by 1.
|
|
*/
|
|
static inline void atomic_dec(atomic_t *v)
|
|
{
|
|
asm volatile(LOCK_PREFIX "decl %0"
|
|
: "+m" (v->counter));
|
|
}
|
|
|
|
/**
|
|
* atomic_inc_short - increment of a short integer
|
|
* @v: pointer to type int
|
|
*
|
|
* Atomically adds 1 to @v
|
|
* Returns the new value of @u
|
|
*/
|
|
static inline short int atomic_inc_short(short int *v)
|
|
{
|
|
asm(LOCK_PREFIX "addw $1, %0" : "+m" (*v));
|
|
return *v;
|
|
}
|
|
|
|
/* These are x86-specific, used by some header files */
|
|
#define atomic_clear_mask(mask, addr) \
|
|
asm volatile(LOCK_PREFIX "andl %0,%1" \
|
|
: : "r" (~(mask)), "m" (*(addr)) : "memory")
|
|
|
|
#define atomic_set_mask(mask, addr) \
|
|
asm volatile(LOCK_PREFIX "orl %0,%1" \
|
|
: : "r" ((unsigned)(mask)), "m" (*(addr)) \
|
|
: "memory")
|
|
|
|
#endif /* _ASM_X86_ATOMIC_H */
|