mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-13 17:36:46 +07:00
62e8a3258b
This patch makes sure that atomic_{read,set}() are at least
{READ,WRITE}_ONCE().
We already had the 'requirement' that atomic_read() should use
ACCESS_ONCE(), and most archs had this, but a few were lacking.
All are now converted to use READ_ONCE().
And, by a symmetry and general paranoia argument, upgrade atomic_set()
to use WRITE_ONCE().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: james.hogan@imgtec.com
Cc: linux-kernel@vger.kernel.org
Cc: oleg@redhat.com
Cc: will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
67 lines
1.6 KiB
C
67 lines
1.6 KiB
C
#ifndef __ASM_SH_ATOMIC_H
|
|
#define __ASM_SH_ATOMIC_H
|
|
|
|
/*
|
|
* Atomic operations that C can't guarantee us. Useful for
|
|
* resource counting etc..
|
|
*
|
|
*/
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/types.h>
|
|
#include <asm/cmpxchg.h>
|
|
#include <asm/barrier.h>
|
|
|
|
#define ATOMIC_INIT(i) { (i) }
|
|
|
|
#define atomic_read(v) READ_ONCE((v)->counter)
|
|
#define atomic_set(v,i) WRITE_ONCE((v)->counter, (i))
|
|
|
|
#if defined(CONFIG_GUSA_RB)
|
|
#include <asm/atomic-grb.h>
|
|
#elif defined(CONFIG_CPU_SH4A)
|
|
#include <asm/atomic-llsc.h>
|
|
#else
|
|
#include <asm/atomic-irq.h>
|
|
#endif
|
|
|
|
#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
|
|
#define atomic_dec_return(v) atomic_sub_return(1, (v))
|
|
#define atomic_inc_return(v) atomic_add_return(1, (v))
|
|
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
|
|
#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
|
|
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
|
|
|
|
#define atomic_inc(v) atomic_add(1, (v))
|
|
#define atomic_dec(v) atomic_sub(1, (v))
|
|
|
|
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
|
|
#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
|
|
|
|
/**
|
|
* __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 c, old;
|
|
c = atomic_read(v);
|
|
for (;;) {
|
|
if (unlikely(c == (u)))
|
|
break;
|
|
old = atomic_cmpxchg((v), c, c + (a));
|
|
if (likely(old == c))
|
|
break;
|
|
c = old;
|
|
}
|
|
|
|
return c;
|
|
}
|
|
|
|
#endif /* __ASM_SH_ATOMIC_H */
|