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authorArun Sharma <asharma@fb.com>2011-07-26 16:09:07 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-26 16:49:47 -0700
commitf24219b4e90cf70ec4a211b17fbabc725a0ddf3c (patch)
treec1c753bd425d61a5094995d9835b23b46383d9b2 /arch/avr32
parent60063497a95e716c9a689af3be2687d261f115b4 (diff)
atomic: move atomic_add_unless to generic code
This is in preparation for more generic atomic primitives based on __atomic_add_unless. Signed-off-by: Arun Sharma <asharma@fb.com> Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/avr32')
-rw-r--r--arch/avr32/include/asm/atomic.h57
1 files changed, 25 insertions, 32 deletions
diff --git a/arch/avr32/include/asm/atomic.h b/arch/avr32/include/asm/atomic.h
index f229c3849f03..dc6c3a41a2d7 100644
--- a/arch/avr32/include/asm/atomic.h
+++ b/arch/avr32/include/asm/atomic.h
@@ -78,70 +78,63 @@ static inline int atomic_add_return(int i, atomic_t *v)
/*
* atomic_sub_unless - sub unless the number is a given value
* @v: pointer of type atomic_t
- * @a: the amount to add to v...
+ * @a: the amount to subtract from v...
* @u: ...unless v is equal to u.
*
- * If the atomic value v is not equal to u, this function subtracts a
- * from v, and returns non zero. If v is equal to u then it returns
- * zero. This is done as an atomic operation.
+ * Atomically subtract @a from @v, so long as it was not @u.
+ * Returns the old value of @v.
*/
-static inline int atomic_sub_unless(atomic_t *v, int a, int u)
+static inline void atomic_sub_unless(atomic_t *v, int a, int u)
{
- int tmp, result = 0;
+ int tmp;
asm volatile(
"/* atomic_sub_unless */\n"
"1: ssrf 5\n"
- " ld.w %0, %3\n"
- " cp.w %0, %5\n"
+ " ld.w %0, %2\n"
+ " cp.w %0, %4\n"
" breq 1f\n"
- " sub %0, %4\n"
- " stcond %2, %0\n"
+ " sub %0, %3\n"
+ " stcond %1, %0\n"
" brne 1b\n"
- " mov %1, 1\n"
"1:"
- : "=&r"(tmp), "=&r"(result), "=o"(v->counter)
- : "m"(v->counter), "rKs21"(a), "rKs21"(u), "1"(result)
+ : "=&r"(tmp), "=o"(v->counter)
+ : "m"(v->counter), "rKs21"(a), "rKs21"(u)
: "cc", "memory");
-
- return result;
}
/*
- * atomic_add_unless - add unless the number is a given value
+ * __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.
*
- * If the atomic value v is not equal to u, this function adds a to v,
- * and returns non zero. If v is equal to u then it returns zero. This
- * is done as an atomic operation.
+ * 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)
+static inline int __atomic_add_unless(atomic_t *v, int a, int u)
{
- int tmp, result;
+ int tmp, old = atomic_read(v);
if (__builtin_constant_p(a) && (a >= -1048575) && (a <= 1048576))
- result = atomic_sub_unless(v, -a, u);
+ atomic_sub_unless(v, -a, u);
else {
- result = 0;
asm volatile(
- "/* atomic_add_unless */\n"
+ "/* __atomic_add_unless */\n"
"1: ssrf 5\n"
- " ld.w %0, %3\n"
- " cp.w %0, %5\n"
+ " ld.w %0, %2\n"
+ " cp.w %0, %4\n"
" breq 1f\n"
- " add %0, %4\n"
- " stcond %2, %0\n"
+ " add %0, %3\n"
+ " stcond %1, %0\n"
" brne 1b\n"
- " mov %1, 1\n"
"1:"
- : "=&r"(tmp), "=&r"(result), "=o"(v->counter)
- : "m"(v->counter), "r"(a), "ir"(u), "1"(result)
+ : "=&r"(tmp), "=o"(v->counter)
+ : "m"(v->counter), "r"(a), "ir"(u)
: "cc", "memory");
}
- return result;
+ return old;
}
/*