X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fsparc64%2Flib%2Fatomic.S;h=41be4131f8008429687bd5b84953e95981803a77;hb=6a77f38946aaee1cd85eeec6cf4229b204c15071;hp=26463d8a467ae8cc0923a37b0d1719e15fb91d6d;hpb=87fc8d1bb10cd459024a742c6a10961fefcef18f;p=linux-2.6.git

diff --git a/arch/sparc64/lib/atomic.S b/arch/sparc64/lib/atomic.S
index 26463d8a4..41be4131f 100644
--- a/arch/sparc64/lib/atomic.S
+++ b/arch/sparc64/lib/atomic.S
@@ -4,59 +4,136 @@
  * Copyright (C) 1999 David S. Miller (davem@redhat.com)
  */
 
+#include <linux/config.h>
 #include <asm/asi.h>
 
+	/* On SMP we need to use memory barriers to ensure
+	 * correct memory operation ordering, nop these out
+	 * for uniprocessor.
+	 */
+#ifdef CONFIG_SMP
+#define ATOMIC_PRE_BARRIER	membar #StoreLoad | #LoadLoad
+#define ATOMIC_POST_BARRIER	membar #StoreLoad | #StoreStore
+#else
+#define ATOMIC_PRE_BARRIER	nop
+#define ATOMIC_POST_BARRIER	nop
+#endif
+
 	.text
-	.align	64
 
-	.globl	__atomic_add
-	.type	__atomic_add,#function
-__atomic_add: /* %o0 = increment, %o1 = atomic_ptr */
-	lduw	[%o1], %g5
+	/* Two versions of the atomic routines, one that
+	 * does not return a value and does not perform
+	 * memory barriers, and a second which returns
+	 * a value and does the barriers.
+	 */
+	.globl	atomic_add
+	.type	atomic_add,#function
+atomic_add: /* %o0 = increment, %o1 = atomic_ptr */
+1:	lduw	[%o1], %g5
+	add	%g5, %o0, %g7
+	cas	[%o1], %g5, %g7
+	cmp	%g5, %g7
+	bne,pn	%icc, 1b
+	 nop
+	retl
+	 nop
+	.size	atomic_add, .-atomic_add
+
+	.globl	atomic_sub
+	.type	atomic_sub,#function
+atomic_sub: /* %o0 = decrement, %o1 = atomic_ptr */
+1:	lduw	[%o1], %g5
+	sub	%g5, %o0, %g7
+	cas	[%o1], %g5, %g7
+	cmp	%g5, %g7
+	bne,pn	%icc, 1b
+	 nop
+	retl
+	 nop
+	.size	atomic_sub, .-atomic_sub
+
+	.globl	atomic_add_ret
+	.type	atomic_add_ret,#function
+atomic_add_ret: /* %o0 = increment, %o1 = atomic_ptr */
+	ATOMIC_PRE_BARRIER
+1:	lduw	[%o1], %g5
 	add	%g5, %o0, %g7
 	cas	[%o1], %g5, %g7
 	cmp	%g5, %g7
-	bne,pn	%icc, __atomic_add
-	 membar	#StoreLoad | #StoreStore
+	bne,pn	%icc, 1b
+	 add	%g7, %o0, %g7
+	ATOMIC_POST_BARRIER
 	retl
-	 add	%g7, %o0, %o0
-	.size	__atomic_add, .-__atomic_add
+	 sra	%g7, 0, %o0
+	.size	atomic_add_ret, .-atomic_add_ret
 
-	.globl	__atomic_sub
-	.type	__atomic_sub,#function
-__atomic_sub: /* %o0 = increment, %o1 = atomic_ptr */
-	lduw	[%o1], %g5
+	.globl	atomic_sub_ret
+	.type	atomic_sub_ret,#function
+atomic_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */
+	ATOMIC_PRE_BARRIER
+1:	lduw	[%o1], %g5
 	sub	%g5, %o0, %g7
 	cas	[%o1], %g5, %g7
 	cmp	%g5, %g7
-	bne,pn	%icc, __atomic_sub
-	 membar	#StoreLoad | #StoreStore
+	bne,pn	%icc, 1b
+	 sub	%g7, %o0, %g7
+	ATOMIC_POST_BARRIER
+	retl
+	 sra	%g7, 0, %o0
+	.size	atomic_sub_ret, .-atomic_sub_ret
+
+	.globl	atomic64_add
+	.type	atomic64_add,#function
+atomic64_add: /* %o0 = increment, %o1 = atomic_ptr */
+1:	ldx	[%o1], %g5
+	add	%g5, %o0, %g7
+	casx	[%o1], %g5, %g7
+	cmp	%g5, %g7
+	bne,pn	%xcc, 1b
+	 nop
+	retl
+	 nop
+	.size	atomic64_add, .-atomic64_add
+
+	.globl	atomic64_sub
+	.type	atomic64_sub,#function
+atomic64_sub: /* %o0 = decrement, %o1 = atomic_ptr */
+1:	ldx	[%o1], %g5
+	sub	%g5, %o0, %g7
+	casx	[%o1], %g5, %g7
+	cmp	%g5, %g7
+	bne,pn	%xcc, 1b
+	 nop
 	retl
-	 sub	%g7, %o0, %o0
-	.size	__atomic_sub, .-__atomic_sub
+	 nop
+	.size	atomic64_sub, .-atomic64_sub
 
-	.globl	__atomic64_add
-	.type	__atomic64_add,#function
-__atomic64_add: /* %o0 = increment, %o1 = atomic_ptr */
-	ldx	[%o1], %g5
+	.globl	atomic64_add_ret
+	.type	atomic64_add_ret,#function
+atomic64_add_ret: /* %o0 = increment, %o1 = atomic_ptr */
+	ATOMIC_PRE_BARRIER
+1:	ldx	[%o1], %g5
 	add	%g5, %o0, %g7
 	casx	[%o1], %g5, %g7
 	cmp	%g5, %g7
-	bne,pn	%xcc, __atomic64_add
-	 membar	#StoreLoad | #StoreStore
+	bne,pn	%xcc, 1b
+	 add	%g7, %o0, %g7
+	ATOMIC_POST_BARRIER
 	retl
-	 add	%g7, %o0, %o0
-	.size	__atomic64_add, .-__atomic64_add
+	 mov	%g7, %o0
+	.size	atomic64_add_ret, .-atomic64_add_ret
 
-	.globl	__atomic64_sub
-	.type	__atomic64_sub,#function
-__atomic64_sub: /* %o0 = increment, %o1 = atomic_ptr */
-	ldx	[%o1], %g5
+	.globl	atomic64_sub_ret
+	.type	atomic64_sub_ret,#function
+atomic64_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */
+	ATOMIC_PRE_BARRIER
+1:	ldx	[%o1], %g5
 	sub	%g5, %o0, %g7
 	casx	[%o1], %g5, %g7
 	cmp	%g5, %g7
-	bne,pn	%xcc, __atomic64_sub
-	 membar	#StoreLoad | #StoreStore
+	bne,pn	%xcc, 1b
+	 sub	%g7, %o0, %g7
+	ATOMIC_POST_BARRIER
 	retl
-	 sub	%g7, %o0, %o0
-	.size	__atomic64_sub, .-__atomic64_sub
+	 mov	%g7, %o0
+	.size	atomic64_sub_ret, .-atomic64_sub_ret