linux_dsm_epyc7002/arch/avr32/include/asm/atomic.h
Peter Zijlstra 710adaa913 arch,avr32: Convert smp_mb__*()
AVR32's mb() implementation is a compiler barrier(), therefore it all
doesn't matter, fully rely on whatever asm-generic/barrier.h
generates.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-8gow97a7mapmnec0pvf729pj@git.kernel.org
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-18 11:40:33 +02:00

187 lines
4.5 KiB
C

/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc.
*
* But use these as seldom as possible since they are slower than
* regular operations.
*
* Copyright (C) 2004-2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_AVR32_ATOMIC_H
#define __ASM_AVR32_ATOMIC_H
#include <linux/types.h>
#include <asm/cmpxchg.h>
#define ATOMIC_INIT(i) { (i) }
#define atomic_read(v) (*(volatile int *)&(v)->counter)
#define atomic_set(v, i) (((v)->counter) = i)
/*
* atomic_sub_return - subtract the atomic variable
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically subtracts @i from @v. Returns the resulting value.
*/
static inline int atomic_sub_return(int i, atomic_t *v)
{
int result;
asm volatile(
"/* atomic_sub_return */\n"
"1: ssrf 5\n"
" ld.w %0, %2\n"
" sub %0, %3\n"
" stcond %1, %0\n"
" brne 1b"
: "=&r"(result), "=o"(v->counter)
: "m"(v->counter), "rKs21"(i)
: "cc");
return result;
}
/*
* atomic_add_return - add integer to atomic variable
* @i: integer value to add
* @v: pointer of type atomic_t
*
* Atomically adds @i to @v. Returns the resulting value.
*/
static inline int atomic_add_return(int i, atomic_t *v)
{
int result;
if (__builtin_constant_p(i) && (i >= -1048575) && (i <= 1048576))
result = atomic_sub_return(-i, v);
else
asm volatile(
"/* atomic_add_return */\n"
"1: ssrf 5\n"
" ld.w %0, %1\n"
" add %0, %3\n"
" stcond %2, %0\n"
" brne 1b"
: "=&r"(result), "=o"(v->counter)
: "m"(v->counter), "r"(i)
: "cc", "memory");
return result;
}
/*
* atomic_sub_unless - sub unless the number is a given value
* @v: pointer of type atomic_t
* @a: the amount to subtract from v...
* @u: ...unless v is equal to u.
*
* Atomically subtract @a from @v, so long as it was not @u.
* Returns the old value of @v.
*/
static inline void atomic_sub_unless(atomic_t *v, int a, int u)
{
int tmp;
asm volatile(
"/* atomic_sub_unless */\n"
"1: ssrf 5\n"
" ld.w %0, %2\n"
" cp.w %0, %4\n"
" breq 1f\n"
" sub %0, %3\n"
" stcond %1, %0\n"
" brne 1b\n"
"1:"
: "=&r"(tmp), "=o"(v->counter)
: "m"(v->counter), "rKs21"(a), "rKs21"(u)
: "cc", "memory");
}
/*
* __atomic_add_unless - add unless the number is a given value
* @v: pointer of type atomic_t
* @a: the amount to add to v...
* @u: ...unless v is equal to u.
*
* Atomically adds @a to @v, so long as it was not @u.
* Returns the old value of @v.
*/
static inline int __atomic_add_unless(atomic_t *v, int a, int u)
{
int tmp, old = atomic_read(v);
if (__builtin_constant_p(a) && (a >= -1048575) && (a <= 1048576))
atomic_sub_unless(v, -a, u);
else {
asm volatile(
"/* __atomic_add_unless */\n"
"1: ssrf 5\n"
" ld.w %0, %2\n"
" cp.w %0, %4\n"
" breq 1f\n"
" add %0, %3\n"
" stcond %1, %0\n"
" brne 1b\n"
"1:"
: "=&r"(tmp), "=o"(v->counter)
: "m"(v->counter), "r"(a), "ir"(u)
: "cc", "memory");
}
return old;
}
/*
* atomic_sub_if_positive - conditionally subtract integer from atomic variable
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically test @v and subtract @i if @v is greater or equal than @i.
* The function returns the old value of @v minus @i.
*/
static inline int atomic_sub_if_positive(int i, atomic_t *v)
{
int result;
asm volatile(
"/* atomic_sub_if_positive */\n"
"1: ssrf 5\n"
" ld.w %0, %2\n"
" sub %0, %3\n"
" brlt 1f\n"
" stcond %1, %0\n"
" brne 1b\n"
"1:"
: "=&r"(result), "=o"(v->counter)
: "m"(v->counter), "ir"(i)
: "cc", "memory");
return result;
}
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
#define atomic_sub(i, v) (void)atomic_sub_return(i, v)
#define atomic_add(i, v) (void)atomic_add_return(i, v)
#define atomic_dec(v) atomic_sub(1, (v))
#define atomic_inc(v) atomic_add(1, (v))
#define atomic_dec_return(v) atomic_sub_return(1, v)
#define atomic_inc_return(v) atomic_add_return(1, v)
#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
#define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0)
#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0)
#define atomic_add_negative(i, v) (atomic_add_return(i, v) < 0)
#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v)
#endif /* __ASM_AVR32_ATOMIC_H */