mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-27 22:24:11 +08:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
159 lines
4.5 KiB
C
159 lines
4.5 KiB
C
/* atomic.h: These still suck, but the I-cache hit rate is higher.
|
|
*
|
|
* Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
|
|
* Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com.au)
|
|
*
|
|
* Additions by Keith M Wesolowski (wesolows@foobazco.org) based
|
|
* on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>.
|
|
*/
|
|
|
|
#ifndef __ARCH_SPARC_ATOMIC__
|
|
#define __ARCH_SPARC_ATOMIC__
|
|
|
|
#include <linux/config.h>
|
|
|
|
typedef struct { volatile int counter; } atomic_t;
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
#define ATOMIC_INIT(i) { (i) }
|
|
|
|
extern int __atomic_add_return(int, atomic_t *);
|
|
extern void atomic_set(atomic_t *, int);
|
|
|
|
#define atomic_read(v) ((v)->counter)
|
|
|
|
#define atomic_add(i, v) ((void)__atomic_add_return( (int)(i), (v)))
|
|
#define atomic_sub(i, v) ((void)__atomic_add_return(-(int)(i), (v)))
|
|
#define atomic_inc(v) ((void)__atomic_add_return( 1, (v)))
|
|
#define atomic_dec(v) ((void)__atomic_add_return( -1, (v)))
|
|
|
|
#define atomic_add_return(i, v) (__atomic_add_return( (int)(i), (v)))
|
|
#define atomic_sub_return(i, v) (__atomic_add_return(-(int)(i), (v)))
|
|
#define atomic_inc_return(v) (__atomic_add_return( 1, (v)))
|
|
#define atomic_dec_return(v) (__atomic_add_return( -1, (v)))
|
|
|
|
#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
|
|
|
|
/*
|
|
* atomic_inc_and_test - increment and test
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* Atomically increments @v by 1
|
|
* and returns true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
|
|
|
|
#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
|
|
#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
|
|
|
|
/* This is the old 24-bit implementation. It's still used internally
|
|
* by some sparc-specific code, notably the semaphore implementation.
|
|
*/
|
|
typedef struct { volatile int counter; } atomic24_t;
|
|
|
|
#ifndef CONFIG_SMP
|
|
|
|
#define ATOMIC24_INIT(i) { (i) }
|
|
#define atomic24_read(v) ((v)->counter)
|
|
#define atomic24_set(v, i) (((v)->counter) = i)
|
|
|
|
#else
|
|
/* We do the bulk of the actual work out of line in two common
|
|
* routines in assembler, see arch/sparc/lib/atomic.S for the
|
|
* "fun" details.
|
|
*
|
|
* For SMP the trick is you embed the spin lock byte within
|
|
* the word, use the low byte so signedness is easily retained
|
|
* via a quick arithmetic shift. It looks like this:
|
|
*
|
|
* ----------------------------------------
|
|
* | signed 24-bit counter value | lock | atomic_t
|
|
* ----------------------------------------
|
|
* 31 8 7 0
|
|
*/
|
|
|
|
#define ATOMIC24_INIT(i) { ((i) << 8) }
|
|
|
|
static inline int atomic24_read(const atomic24_t *v)
|
|
{
|
|
int ret = v->counter;
|
|
|
|
while(ret & 0xff)
|
|
ret = v->counter;
|
|
|
|
return ret >> 8;
|
|
}
|
|
|
|
#define atomic24_set(v, i) (((v)->counter) = ((i) << 8))
|
|
#endif
|
|
|
|
static inline int __atomic24_add(int i, atomic24_t *v)
|
|
{
|
|
register volatile int *ptr asm("g1");
|
|
register int increment asm("g2");
|
|
register int tmp1 asm("g3");
|
|
register int tmp2 asm("g4");
|
|
register int tmp3 asm("g7");
|
|
|
|
ptr = &v->counter;
|
|
increment = i;
|
|
|
|
__asm__ __volatile__(
|
|
"mov %%o7, %%g4\n\t"
|
|
"call ___atomic24_add\n\t"
|
|
" add %%o7, 8, %%o7\n"
|
|
: "=&r" (increment), "=r" (tmp1), "=r" (tmp2), "=r" (tmp3)
|
|
: "0" (increment), "r" (ptr)
|
|
: "memory", "cc");
|
|
|
|
return increment;
|
|
}
|
|
|
|
static inline int __atomic24_sub(int i, atomic24_t *v)
|
|
{
|
|
register volatile int *ptr asm("g1");
|
|
register int increment asm("g2");
|
|
register int tmp1 asm("g3");
|
|
register int tmp2 asm("g4");
|
|
register int tmp3 asm("g7");
|
|
|
|
ptr = &v->counter;
|
|
increment = i;
|
|
|
|
__asm__ __volatile__(
|
|
"mov %%o7, %%g4\n\t"
|
|
"call ___atomic24_sub\n\t"
|
|
" add %%o7, 8, %%o7\n"
|
|
: "=&r" (increment), "=r" (tmp1), "=r" (tmp2), "=r" (tmp3)
|
|
: "0" (increment), "r" (ptr)
|
|
: "memory", "cc");
|
|
|
|
return increment;
|
|
}
|
|
|
|
#define atomic24_add(i, v) ((void)__atomic24_add((i), (v)))
|
|
#define atomic24_sub(i, v) ((void)__atomic24_sub((i), (v)))
|
|
|
|
#define atomic24_dec_return(v) __atomic24_sub(1, (v))
|
|
#define atomic24_inc_return(v) __atomic24_add(1, (v))
|
|
|
|
#define atomic24_sub_and_test(i, v) (__atomic24_sub((i), (v)) == 0)
|
|
#define atomic24_dec_and_test(v) (__atomic24_sub(1, (v)) == 0)
|
|
|
|
#define atomic24_inc(v) ((void)__atomic24_add(1, (v)))
|
|
#define atomic24_dec(v) ((void)__atomic24_sub(1, (v)))
|
|
|
|
#define atomic24_add_negative(i, v) (__atomic24_add((i), (v)) < 0)
|
|
|
|
/* Atomic operations are already serializing */
|
|
#define smp_mb__before_atomic_dec() barrier()
|
|
#define smp_mb__after_atomic_dec() barrier()
|
|
#define smp_mb__before_atomic_inc() barrier()
|
|
#define smp_mb__after_atomic_inc() barrier()
|
|
|
|
#endif /* !(__KERNEL__) */
|
|
|
|
#endif /* !(__ARCH_SPARC_ATOMIC__) */
|