[SPARC64]: Avoid membar instructions in delay slots.

In particular, avoid membar instructions in the delay slot of a jmpl instruction. UltraSPARC-I, II, IIi, and IIe have a bug, documented in the UltraSPARC-IIi User's Manual, Appendix K, Erratum 51 The long and short of it is that if the IMU unit misses on a branch or jmpl, and there is a store buffer synchronizing membar in the delay slot, the chip can stop fetching instructions. If interrupts are enabled or some other trap is enabled, the chip will unwedge itself, but performance will suffer. We already had a workaround for this bug in a few spots, but it's better to have the entire tree sanitized for this rule. Signed-off-by: David S. Miller <davem@davemloft.net>
2024-12-18 10:13:57 +08:00 · 2005-06-27 15:42:04 -07:00 · 2005-06-27 15:42:04 -07:00 · b445e26cbf
commit b445e26cbf
parent 020f46a39e
15 changed files with 172 additions and 111 deletions
--- a/arch/sparc64/kernel/entry.S
+++ b/arch/sparc64/kernel/entry.S
@ -271,8 +271,9 @@ cplus_fptrap_insn_1:
 	fmuld		%f0, %f2, %f26
 	faddd		%f0, %f2, %f28
 	fmuld		%f0, %f2, %f30
+	membar		#Sync
 	b,pt		%xcc, fpdis_exit
-	 membar		#Sync
+	 nop
 2:	andcc		%g5, FPRS_DU, %g0
 	bne,pt		%icc, 3f
 	 fzero		%f32
@ -301,8 +302,9 @@ cplus_fptrap_insn_2:
 	fmuld		%f32, %f34, %f58
 	faddd		%f32, %f34, %f60
 	fmuld		%f32, %f34, %f62
+	membar		#Sync
 	ba,pt		%xcc, fpdis_exit
-	 membar		#Sync
+	 nop
 3:	mov		SECONDARY_CONTEXT, %g3
 	add		%g6, TI_FPREGS, %g1
 	ldxa		[%g3] ASI_DMMU, %g5
--- a/arch/sparc64/kernel/semaphore.c
+++ b/arch/sparc64/kernel/semaphore.c
@ -32,8 +32,9 @@ static __inline__ int __sem_update_count(struct semaphore *sem, int incr)
 "	add	%1, %4, %1\n"
 "	cas	[%3], %0, %1\n"
 "	cmp	%0, %1\n"
+"	membar	#StoreLoad | #StoreStore\n"
 "	bne,pn	%%icc, 1b\n"
-"	 membar #StoreLoad | #StoreStore\n"
+"	 nop\n"
 	: "=&r" (old_count), "=&r" (tmp), "=m" (sem->count)
 	: "r" (&sem->count), "r" (incr), "m" (sem->count)
 	: "cc");
@ -71,8 +72,9 @@ void up(struct semaphore *sem)
 "	cmp	%%g1, %%g7\n"
 "	bne,pn	%%icc, 1b\n"
 "	 addcc	%%g7, 1, %%g0\n"
+"	membar	#StoreLoad | #StoreStore\n"
 "	ble,pn	%%icc, 3f\n"
-"	 membar	#StoreLoad | #StoreStore\n"
+"	 nop\n"
 "2:\n"
 "	.subsection 2\n"
 "3:	mov	%0, %%g1\n"
@ -128,8 +130,9 @@ void __sched down(struct semaphore *sem)
 "	cmp	%%g1, %%g7\n"
 "	bne,pn	%%icc, 1b\n"
 "	 cmp	%%g7, 1\n"
+"	membar	#StoreLoad | #StoreStore\n"
 "	bl,pn	%%icc, 3f\n"
-"	 membar	#StoreLoad | #StoreStore\n"
+"	 nop\n"
 "2:\n"
 "	.subsection 2\n"
 "3:	mov	%0, %%g1\n"
@ -233,8 +236,9 @@ int __sched down_interruptible(struct semaphore *sem)
 "	cmp	%%g1, %%g7\n"
 "	bne,pn	%%icc, 1b\n"
 "	 cmp	%%g7, 1\n"
+"	membar	#StoreLoad | #StoreStore\n"
 "	bl,pn	%%icc, 3f\n"
-"	 membar	#StoreLoad | #StoreStore\n"
+"	 nop\n"
 "2:\n"
 "	.subsection 2\n"
 "3:	mov	%2, %%g1\n"
--- a/arch/sparc64/kernel/trampoline.S
+++ b/arch/sparc64/kernel/trampoline.S
@ -98,8 +98,9 @@ startup_continue:

 	sethi		%hi(prom_entry_lock), %g2
 1:	ldstub		[%g2 + %lo(prom_entry_lock)], %g1
+	membar		#StoreLoad | #StoreStore
 	brnz,pn		%g1, 1b
-	 membar		#StoreLoad | #StoreStore
+	 nop

 	sethi		%hi(p1275buf), %g2
 	or		%g2, %lo(p1275buf), %g2
--- a/arch/sparc64/lib/U1memcpy.S
+++ b/arch/sparc64/lib/U1memcpy.S
@ -87,14 +87,17 @@
 #define LOOP_CHUNK3(src, dest, len, branch_dest)		\
 	MAIN_LOOP_CHUNK(src, dest, f32, f48, len, branch_dest)

+#define DO_SYNC			membar	#Sync;
 #define STORE_SYNC(dest, fsrc)				\
 	EX_ST(STORE_BLK(%fsrc, %dest));			\
-	add			%dest, 0x40, %dest;
+	add			%dest, 0x40, %dest;	\
+	DO_SYNC

 #define STORE_JUMP(dest, fsrc, target)			\
 	EX_ST(STORE_BLK(%fsrc, %dest));			\
 	add			%dest, 0x40, %dest;	\
-	ba,pt			%xcc, target;
+	ba,pt			%xcc, target;		\
+	 nop;

 #define FINISH_VISCHUNK(dest, f0, f1, left)	\
 	subcc			%left, 8, %left;\
@ -239,17 +242,17 @@ FUNC_NAME:		/* %o0=dst, %o1=src, %o2=len */
 	ba,pt		%xcc, 1b+4
 	 faligndata	%f0, %f2, %f48
 1:	FREG_FROB(f16,f18,f20,f22,f24,f26,f28,f30,f32)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f32,f34,f36,f38,f40,f42,f44,f46,f0)
-	STORE_JUMP(o0, f48, 40f) membar #Sync
+	STORE_JUMP(o0, f48, 40f)
 2:	FREG_FROB(f32,f34,f36,f38,f40,f42,f44,f46,f0)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f0, f2, f4, f6, f8, f10,f12,f14,f16)
-	STORE_JUMP(o0, f48, 48f) membar #Sync
+	STORE_JUMP(o0, f48, 48f)
 3:	FREG_FROB(f0, f2, f4, f6, f8, f10,f12,f14,f16)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f16,f18,f20,f22,f24,f26,f28,f30,f32)
-	STORE_JUMP(o0, f48, 56f) membar #Sync
+	STORE_JUMP(o0, f48, 56f)

 1:	FREG_FROB(f2, f4, f6, f8, f10,f12,f14,f16,f18)
 	LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
@ -260,17 +263,17 @@ FUNC_NAME:		/* %o0=dst, %o1=src, %o2=len */
 	ba,pt		%xcc, 1b+4
 	 faligndata	%f2, %f4, %f48
 1:	FREG_FROB(f18,f20,f22,f24,f26,f28,f30,f32,f34)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f34,f36,f38,f40,f42,f44,f46,f0, f2)
-	STORE_JUMP(o0, f48, 41f) membar #Sync
+	STORE_JUMP(o0, f48, 41f)
 2:	FREG_FROB(f34,f36,f38,f40,f42,f44,f46,f0, f2)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f2, f4, f6, f8, f10,f12,f14,f16,f18)
-	STORE_JUMP(o0, f48, 49f) membar #Sync
+	STORE_JUMP(o0, f48, 49f)
 3:	FREG_FROB(f2, f4, f6, f8, f10,f12,f14,f16,f18)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f18,f20,f22,f24,f26,f28,f30,f32,f34)
-	STORE_JUMP(o0, f48, 57f) membar #Sync
+	STORE_JUMP(o0, f48, 57f)

 1:	FREG_FROB(f4, f6, f8, f10,f12,f14,f16,f18,f20)
 	LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
@ -281,17 +284,17 @@ FUNC_NAME:		/* %o0=dst, %o1=src, %o2=len */
 	ba,pt		%xcc, 1b+4
 	 faligndata	%f4, %f6, %f48
 1:	FREG_FROB(f20,f22,f24,f26,f28,f30,f32,f34,f36)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f36,f38,f40,f42,f44,f46,f0, f2, f4)
-	STORE_JUMP(o0, f48, 42f) membar #Sync
+	STORE_JUMP(o0, f48, 42f)
 2:	FREG_FROB(f36,f38,f40,f42,f44,f46,f0, f2, f4)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f4, f6, f8, f10,f12,f14,f16,f18,f20)
-	STORE_JUMP(o0, f48, 50f) membar #Sync
+	STORE_JUMP(o0, f48, 50f)
 3:	FREG_FROB(f4, f6, f8, f10,f12,f14,f16,f18,f20)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f20,f22,f24,f26,f28,f30,f32,f34,f36)
-	STORE_JUMP(o0, f48, 58f) membar #Sync
+	STORE_JUMP(o0, f48, 58f)

 1:	FREG_FROB(f6, f8, f10,f12,f14,f16,f18,f20,f22)
 	LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
@ -302,17 +305,17 @@ FUNC_NAME:		/* %o0=dst, %o1=src, %o2=len */
 	ba,pt		%xcc, 1b+4
 	 faligndata	%f6, %f8, %f48
 1:	FREG_FROB(f22,f24,f26,f28,f30,f32,f34,f36,f38)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f38,f40,f42,f44,f46,f0, f2, f4, f6)
-	STORE_JUMP(o0, f48, 43f) membar #Sync
+	STORE_JUMP(o0, f48, 43f)
 2:	FREG_FROB(f38,f40,f42,f44,f46,f0, f2, f4, f6)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f6, f8, f10,f12,f14,f16,f18,f20,f22)
-	STORE_JUMP(o0, f48, 51f) membar #Sync
+	STORE_JUMP(o0, f48, 51f)
 3:	FREG_FROB(f6, f8, f10,f12,f14,f16,f18,f20,f22)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f22,f24,f26,f28,f30,f32,f34,f36,f38)
-	STORE_JUMP(o0, f48, 59f) membar #Sync
+	STORE_JUMP(o0, f48, 59f)

 1:	FREG_FROB(f8, f10,f12,f14,f16,f18,f20,f22,f24)
 	LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
@ -323,17 +326,17 @@ FUNC_NAME:		/* %o0=dst, %o1=src, %o2=len */
 	ba,pt		%xcc, 1b+4
 	 faligndata	%f8, %f10, %f48
 1:	FREG_FROB(f24,f26,f28,f30,f32,f34,f36,f38,f40)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f40,f42,f44,f46,f0, f2, f4, f6, f8)
-	STORE_JUMP(o0, f48, 44f) membar #Sync
+	STORE_JUMP(o0, f48, 44f)
 2:	FREG_FROB(f40,f42,f44,f46,f0, f2, f4, f6, f8)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f8, f10,f12,f14,f16,f18,f20,f22,f24)
-	STORE_JUMP(o0, f48, 52f) membar #Sync
+	STORE_JUMP(o0, f48, 52f)
 3:	FREG_FROB(f8, f10,f12,f14,f16,f18,f20,f22,f24)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f24,f26,f28,f30,f32,f34,f36,f38,f40)
-	STORE_JUMP(o0, f48, 60f) membar #Sync
+	STORE_JUMP(o0, f48, 60f)

 1:	FREG_FROB(f10,f12,f14,f16,f18,f20,f22,f24,f26)
 	LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
@ -344,17 +347,17 @@ FUNC_NAME:		/* %o0=dst, %o1=src, %o2=len */
 	ba,pt		%xcc, 1b+4
 	 faligndata	%f10, %f12, %f48
 1:	FREG_FROB(f26,f28,f30,f32,f34,f36,f38,f40,f42)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f42,f44,f46,f0, f2, f4, f6, f8, f10)
-	STORE_JUMP(o0, f48, 45f) membar #Sync
+	STORE_JUMP(o0, f48, 45f)
 2:	FREG_FROB(f42,f44,f46,f0, f2, f4, f6, f8, f10)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f10,f12,f14,f16,f18,f20,f22,f24,f26)
-	STORE_JUMP(o0, f48, 53f) membar #Sync
+	STORE_JUMP(o0, f48, 53f)
 3:	FREG_FROB(f10,f12,f14,f16,f18,f20,f22,f24,f26)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f26,f28,f30,f32,f34,f36,f38,f40,f42)
-	STORE_JUMP(o0, f48, 61f) membar #Sync
+	STORE_JUMP(o0, f48, 61f)

 1:	FREG_FROB(f12,f14,f16,f18,f20,f22,f24,f26,f28)
 	LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
@ -365,17 +368,17 @@ FUNC_NAME:		/* %o0=dst, %o1=src, %o2=len */
 	ba,pt		%xcc, 1b+4
 	 faligndata	%f12, %f14, %f48
 1:	FREG_FROB(f28,f30,f32,f34,f36,f38,f40,f42,f44)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f44,f46,f0, f2, f4, f6, f8, f10,f12)
-	STORE_JUMP(o0, f48, 46f) membar #Sync
+	STORE_JUMP(o0, f48, 46f)
 2:	FREG_FROB(f44,f46,f0, f2, f4, f6, f8, f10,f12)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f12,f14,f16,f18,f20,f22,f24,f26,f28)
-	STORE_JUMP(o0, f48, 54f) membar #Sync
+	STORE_JUMP(o0, f48, 54f)
 3:	FREG_FROB(f12,f14,f16,f18,f20,f22,f24,f26,f28)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f28,f30,f32,f34,f36,f38,f40,f42,f44)
-	STORE_JUMP(o0, f48, 62f) membar #Sync
+	STORE_JUMP(o0, f48, 62f)

 1:	FREG_FROB(f14,f16,f18,f20,f22,f24,f26,f28,f30)
 	LOOP_CHUNK1(o1, o0, GLOBAL_SPARE, 1f)
@ -386,17 +389,17 @@ FUNC_NAME:		/* %o0=dst, %o1=src, %o2=len */
 	ba,pt		%xcc, 1b+4
 	 faligndata	%f14, %f16, %f48
 1:	FREG_FROB(f30,f32,f34,f36,f38,f40,f42,f44,f46)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f46,f0, f2, f4, f6, f8, f10,f12,f14)
-	STORE_JUMP(o0, f48, 47f) membar #Sync
+	STORE_JUMP(o0, f48, 47f)
 2:	FREG_FROB(f46,f0, f2, f4, f6, f8, f10,f12,f14)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f14,f16,f18,f20,f22,f24,f26,f28,f30)
-	STORE_JUMP(o0, f48, 55f) membar #Sync
+	STORE_JUMP(o0, f48, 55f)
 3:	FREG_FROB(f14,f16,f18,f20,f22,f24,f26,f28,f30)
-	STORE_SYNC(o0, f48) membar #Sync
+	STORE_SYNC(o0, f48)
 	FREG_FROB(f30,f32,f34,f36,f38,f40,f42,f44,f46)
-	STORE_JUMP(o0, f48, 63f) membar #Sync
+	STORE_JUMP(o0, f48, 63f)

 40:	FINISH_VISCHUNK(o0, f0,  f2,  g3)
 41:	FINISH_VISCHUNK(o0, f2,  f4,  g3)
--- a/arch/sparc64/lib/VISsave.S
+++ b/arch/sparc64/lib/VISsave.S
@ -72,7 +72,11 @@ vis1:	ldub		[%g6 + TI_FPSAVED], %g3

 	stda		%f48, [%g3 + %g1] ASI_BLK_P
 5:	membar		#Sync
-	jmpl		%g7 + %g0, %g0
+	ba,pt		%xcc, 80f
+	 nop
+
+	.align		32
+80:	jmpl		%g7 + %g0, %g0
 	 nop

 6:	ldub		[%g3 + TI_FPSAVED], %o5
@ -87,8 +91,11 @@ vis1:	ldub		[%g6 + TI_FPSAVED], %g3
 	stda		%f32, [%g2 + %g1] ASI_BLK_P
 	stda		%f48, [%g3 + %g1] ASI_BLK_P
 	membar		#Sync
-	jmpl		%g7 + %g0, %g0
+	ba,pt		%xcc, 80f
+	 nop

+	.align		32
+80:	jmpl		%g7 + %g0, %g0
 	 nop

 	.align		32
@ -126,6 +133,10 @@ VISenterhalf:
 	stda		%f0, [%g2 + %g1] ASI_BLK_P
 	stda		%f16, [%g3 + %g1] ASI_BLK_P
 	membar		#Sync
+	ba,pt		%xcc, 4f
+	 nop
+
+	.align		32
 4:	and		%o5, FPRS_DU, %o5
 	jmpl		%g7 + %g0, %g0
 	 wr		%o5, FPRS_FEF, %fprs
--- a/arch/sparc64/lib/atomic.S
+++ b/arch/sparc64/lib/atomic.S
@ -7,18 +7,6 @@
 #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

 	/* Two versions of the atomic routines, one that
@ -52,6 +40,24 @@ atomic_sub: /* %o0 = decrement, %o1 = atomic_ptr */
 	 nop
 	.size	atomic_sub, .-atomic_sub

+	/* 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	\
+	ba,pt %xcc, 80b;	\
+	membar #StoreLoad | #StoreStore
+
+80:	retl
+	 nop
+#else
+#define ATOMIC_PRE_BARRIER
+#define ATOMIC_POST_BARRIER
+#endif
+
 	.globl	atomic_add_ret
 	.type	atomic_add_ret,#function
 atomic_add_ret: /* %o0 = increment, %o1 = atomic_ptr */
@ -62,9 +68,10 @@ atomic_add_ret: /* %o0 = increment, %o1 = atomic_ptr */
 	cmp	%g1, %g7
 	bne,pn	%icc, 1b
 	 add	%g7, %o0, %g7
+	sra	%g7, 0, %o0
 	ATOMIC_POST_BARRIER
 	retl
-	 sra	%g7, 0, %o0
+	 nop
 	.size	atomic_add_ret, .-atomic_add_ret

 	.globl	atomic_sub_ret
@ -77,9 +84,10 @@ atomic_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */
 	cmp	%g1, %g7
 	bne,pn	%icc, 1b
 	 sub	%g7, %o0, %g7
+	sra	%g7, 0, %o0
 	ATOMIC_POST_BARRIER
 	retl
-	 sra	%g7, 0, %o0
+	 nop
 	.size	atomic_sub_ret, .-atomic_sub_ret

 	.globl	atomic64_add
@ -118,9 +126,10 @@ atomic64_add_ret: /* %o0 = increment, %o1 = atomic_ptr */
 	cmp	%g1, %g7
 	bne,pn	%xcc, 1b
 	 add	%g7, %o0, %g7
+	mov	%g7, %o0
 	ATOMIC_POST_BARRIER
 	retl
-	 mov	%g7, %o0
+	 nop
 	.size	atomic64_add_ret, .-atomic64_add_ret

 	.globl	atomic64_sub_ret
@ -133,7 +142,8 @@ atomic64_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */
 	cmp	%g1, %g7
 	bne,pn	%xcc, 1b
 	 sub	%g7, %o0, %g7
+	mov	%g7, %o0
 	ATOMIC_POST_BARRIER
 	retl
-	 mov	%g7, %o0
+	 nop
 	.size	atomic64_sub_ret, .-atomic64_sub_ret
--- a/arch/sparc64/lib/bitops.S
+++ b/arch/sparc64/lib/bitops.S
@ -7,19 +7,25 @@
 #include <linux/config.h>
 #include <asm/asi.h>

+	.text
+
 	/* On SMP we need to use memory barriers to ensure
 	 * correct memory operation ordering, nop these out
 	 * for uniprocessor.
 	 */
+
 #ifdef CONFIG_SMP
 #define BITOP_PRE_BARRIER	membar #StoreLoad | #LoadLoad
-#define BITOP_POST_BARRIER	membar #StoreLoad | #StoreStore
-#else
-#define BITOP_PRE_BARRIER	nop
-#define BITOP_POST_BARRIER	nop
-#endif
+#define BITOP_POST_BARRIER	\
+	ba,pt	%xcc, 80b;	\
+	membar #StoreLoad | #StoreStore

-	.text
+80:	retl
+	 nop
+#else
+#define BITOP_PRE_BARRIER
+#define BITOP_POST_BARRIER
+#endif

 	.globl	test_and_set_bit
 	.type	test_and_set_bit,#function
@ -37,10 +43,11 @@ test_and_set_bit:	/* %o0=nr, %o1=addr */
 	cmp	%g7, %g1
 	bne,pn	%xcc, 1b
 	 and	%g7, %o2, %g2
-	BITOP_POST_BARRIER
 	clr	%o0
+	movrne	%g2, 1, %o0
+	BITOP_POST_BARRIER
 	retl
-	 movrne	%g2, 1, %o0
+	 nop
 	.size	test_and_set_bit, .-test_and_set_bit

 	.globl	test_and_clear_bit
@ -59,10 +66,11 @@ test_and_clear_bit:	/* %o0=nr, %o1=addr */
 	cmp	%g7, %g1
 	bne,pn	%xcc, 1b
 	 and	%g7, %o2, %g2
-	BITOP_POST_BARRIER
 	clr	%o0
+	movrne	%g2, 1, %o0
+	BITOP_POST_BARRIER
 	retl
-	 movrne	%g2, 1, %o0
+	 nop
 	.size	test_and_clear_bit, .-test_and_clear_bit

 	.globl	test_and_change_bit
@ -81,10 +89,11 @@ test_and_change_bit:	/* %o0=nr, %o1=addr */
 	cmp	%g7, %g1
 	bne,pn	%xcc, 1b
 	 and	%g7, %o2, %g2
-	BITOP_POST_BARRIER
 	clr	%o0
+	movrne	%g2, 1, %o0
+	BITOP_POST_BARRIER
 	retl
-	 movrne	%g2, 1, %o0
+	 nop
 	.size	test_and_change_bit, .-test_and_change_bit

 	.globl	set_bit
--- a/arch/sparc64/lib/debuglocks.c
+++ b/arch/sparc64/lib/debuglocks.c
@ -252,8 +252,9 @@ wlock_again:
 "		andn	%%g1, %%g3, %%g7\n"
 "		casx	[%0], %%g1, %%g7\n"
 "		cmp	%%g1, %%g7\n"
+"		membar	#StoreLoad | #StoreStore\n"
 "		bne,pn	%%xcc, 1b\n"
-"		 membar	#StoreLoad | #StoreStore"
+"		 nop"
 		: /* no outputs */
 		: "r" (&(rw->lock))
 		: "g3", "g1", "g7", "cc", "memory");
@ -351,8 +352,9 @@ int _do_write_trylock (rwlock_t *rw, char *str)
 "		andn	%%g1, %%g3, %%g7\n"
 "		casx	[%0], %%g1, %%g7\n"
 "		cmp	%%g1, %%g7\n"
+"		membar	#StoreLoad | #StoreStore\n"
 "		bne,pn	%%xcc, 1b\n"
-"		 membar	#StoreLoad | #StoreStore"
+"		 nop"
 		: /* no outputs */
 		: "r" (&(rw->lock))
 		: "g3", "g1", "g7", "cc", "memory");
--- a/arch/sparc64/lib/dec_and_lock.S
+++ b/arch/sparc64/lib/dec_and_lock.S
@ -48,8 +48,9 @@ start_to_zero:
 #endif
 to_zero:
 	ldstub	[%o1], %g3
+	membar	#StoreLoad | #StoreStore
 	brnz,pn	%g3, spin_on_lock
-	 membar	#StoreLoad | #StoreStore
+	 nop
 loop2:	cas	[%o0], %g2, %g7		/* ASSERT(g7 == 0) */
 	cmp	%g2, %g7

@ -71,8 +72,9 @@ loop2:	cas	[%o0], %g2, %g7		/* ASSERT(g7 == 0) */
 	 nop
 spin_on_lock:
 	ldub	[%o1], %g3
+	membar	#LoadLoad
 	brnz,pt	%g3, spin_on_lock
-	 membar	#LoadLoad
+	 nop
 	ba,pt	%xcc, to_zero
 	 nop
 	nop
--- a/arch/sparc64/lib/rwsem.S
+++ b/arch/sparc64/lib/rwsem.S
@ -17,8 +17,9 @@ __down_read:
 	bne,pn		%icc, 1b
 	 add		%g7, 1, %g7
 	cmp		%g7, 0
+	membar		#StoreLoad | #StoreStore
 	bl,pn		%icc, 3f
-	 membar		#StoreLoad | #StoreStore
+	 nop
 2:
 	retl
 	 nop
@ -57,8 +58,9 @@ __down_write:
 	cmp		%g3, %g7
 	bne,pn		%icc, 1b
 	 cmp		%g7, 0
+	membar		#StoreLoad | #StoreStore
 	bne,pn		%icc, 3f
-	 membar		#StoreLoad | #StoreStore
+	 nop
 2:	retl
 	 nop
 3:
@ -97,8 +99,9 @@ __up_read:
 	cmp		%g1, %g7
 	bne,pn		%icc, 1b
 	 cmp		%g7, 0
+	membar		#StoreLoad | #StoreStore
 	bl,pn		%icc, 3f
-	 membar		#StoreLoad | #StoreStore
+	 nop
 2:	retl
 	 nop
 3:	sethi		%hi(RWSEM_ACTIVE_MASK), %g1
@ -126,8 +129,9 @@ __up_write:
 	bne,pn		%icc, 1b
 	 sub		%g7, %g1, %g7
 	cmp		%g7, 0
+	membar		#StoreLoad | #StoreStore
 	bl,pn		%icc, 3f
-	 membar		#StoreLoad | #StoreStore
+	 nop
 2:
 	retl
 	 nop
@ -151,8 +155,9 @@ __downgrade_write:
 	bne,pn		%icc, 1b
 	 sub		%g7, %g1, %g7
 	cmp		%g7, 0
+	membar		#StoreLoad | #StoreStore
 	bl,pn		%icc, 3f
-	 membar		#StoreLoad | #StoreStore
+	 nop
 2:
 	retl
 	 nop
--- a/arch/sparc64/mm/init.c
+++ b/arch/sparc64/mm/init.c
@ -136,8 +136,9 @@ static __inline__ void set_dcache_dirty(struct page *page, int this_cpu)
 			     "or	%%g1, %0, %%g1\n\t"
 			     "casx	[%2], %%g7, %%g1\n\t"
 			     "cmp	%%g7, %%g1\n\t"
+			     "membar	#StoreLoad | #StoreStore\n\t"
 			     "bne,pn	%%xcc, 1b\n\t"
-			     " membar	#StoreLoad | #StoreStore"
+			     " nop"
 			     : /* no outputs */
 			     : "r" (mask), "r" (non_cpu_bits), "r" (&page->flags)
 			     : "g1", "g7");
@ -157,8 +158,9 @@ static __inline__ void clear_dcache_dirty_cpu(struct page *page, unsigned long c
 			     " andn	%%g7, %1, %%g1\n\t"
 			     "casx	[%2], %%g7, %%g1\n\t"
 			     "cmp	%%g7, %%g1\n\t"
+			     "membar	#StoreLoad | #StoreStore\n\t"
 			     "bne,pn	%%xcc, 1b\n\t"
-			     " membar	#StoreLoad | #StoreStore\n"
+			     " nop\n"
 			     "2:"
 			     : /* no outputs */
 			     : "r" (cpu), "r" (mask), "r" (&page->flags),
--- a/arch/sparc64/mm/ultra.S
+++ b/arch/sparc64/mm/ultra.S
@ -266,8 +266,9 @@ __cheetah_flush_tlb_pending:	/* 22 insns */
 	 andn		%o3, 1, %o3
 	stxa		%g0, [%o3] ASI_IMMU_DEMAP
 2:	stxa		%g0, [%o3] ASI_DMMU_DEMAP	
+	membar		#Sync
 	brnz,pt		%o1, 1b
-	 membar		#Sync
+	 nop
 	stxa		%g2, [%o4] ASI_DMMU
 	flush		%g6
 	wrpr		%g0, 0, %tl
--- a/include/asm-sparc64/rwsem.h
+++ b/include/asm-sparc64/rwsem.h
@ -55,8 +55,9 @@ static __inline__ int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
 		"add		%%g1, %1, %%g7\n\t"
 		"cas		[%2], %%g1, %%g7\n\t"
 		"cmp		%%g1, %%g7\n\t"
+		"membar		#StoreLoad | #StoreStore\n\t"
 		"bne,pn		%%icc, 1b\n\t"
-		" membar	#StoreLoad | #StoreStore\n\t"
+		" nop\n\t"
 		"mov		%%g7, %0\n\t"
 		: "=&r" (tmp)
 		: "0" (tmp), "r" (sem)
--- a/include/asm-sparc64/spinlock.h
+++ b/include/asm-sparc64/spinlock.h
@ -52,12 +52,14 @@ static inline void _raw_spin_lock(spinlock_t *lock)

 	__asm__ __volatile__(
 "1:	ldstub		[%1], %0\n"
+"	membar		#StoreLoad | #StoreStore\n"
 "	brnz,pn		%0, 2f\n"
-"	 membar		#StoreLoad | #StoreStore\n"
+"	 nop\n"
 "	.subsection	2\n"
 "2:	ldub		[%1], %0\n"
+"	membar		#LoadLoad\n"
 "	brnz,pt		%0, 2b\n"
-"	 membar		#LoadLoad\n"
+"	 nop\n"
 "	ba,a,pt		%%xcc, 1b\n"
 "	.previous"
 	: "=&r" (tmp)
@ -95,16 +97,18 @@ static inline void _raw_spin_lock_flags(spinlock_t *lock, unsigned long flags)

 	__asm__ __volatile__(
 "1:	ldstub		[%2], %0\n"
-"	brnz,pn		%0, 2f\n"
 "	membar		#StoreLoad | #StoreStore\n"
+"	brnz,pn		%0, 2f\n"
+"	 nop\n"
 "	.subsection	2\n"
 "2:	rdpr		%%pil, %1\n"
 "	wrpr		%3, %%pil\n"
 "3:	ldub		[%2], %0\n"
-"	brnz,pt		%0, 3b\n"
 "	membar		#LoadLoad\n"
+"	brnz,pt		%0, 3b\n"
+"	 nop\n"
 "	ba,pt		%%xcc, 1b\n"
-"	wrpr		%1, %%pil\n"
+"	 wrpr		%1, %%pil\n"
 "	.previous"
 	: "=&r" (tmp1), "=&r" (tmp2)
 	: "r"(lock), "r"(flags)
@ -162,12 +166,14 @@ static void inline __read_lock(rwlock_t *lock)
 "4:	 add		%0, 1, %1\n"
 "	cas		[%2], %0, %1\n"
 "	cmp		%0, %1\n"
+"	membar		#StoreLoad | #StoreStore\n"
 "	bne,pn		%%icc, 1b\n"
-"	 membar		#StoreLoad | #StoreStore\n"
+"	 nop\n"
 "	.subsection	2\n"
 "2:	ldsw		[%2], %0\n"
+"	membar		#LoadLoad\n"
 "	brlz,pt		%0, 2b\n"
-"	 membar		#LoadLoad\n"
+"	 nop\n"
 "	ba,a,pt		%%xcc, 4b\n"
 "	.previous"
 	: "=&r" (tmp1), "=&r" (tmp2)
@ -204,12 +210,14 @@ static void inline __write_lock(rwlock_t *lock)
 "4:	 or		%0, %3, %1\n"
 "	cas		[%2], %0, %1\n"
 "	cmp		%0, %1\n"
+"	membar		#StoreLoad | #StoreStore\n"
 "	bne,pn		%%icc, 1b\n"
-"	 membar		#StoreLoad | #StoreStore\n"
+"	 nop\n"
 "	.subsection	2\n"
 "2:	lduw		[%2], %0\n"
+"	membar		#LoadLoad\n"
 "	brnz,pt		%0, 2b\n"
-"	 membar		#LoadLoad\n"
+"	 nop\n"
 "	ba,a,pt		%%xcc, 4b\n"
 "	.previous"
 	: "=&r" (tmp1), "=&r" (tmp2)
@ -240,8 +248,9 @@ static int inline __write_trylock(rwlock_t *lock)
 "	 or		%0, %4, %1\n"
 "	cas		[%3], %0, %1\n"
 "	cmp		%0, %1\n"
+"	membar		#StoreLoad | #StoreStore\n"
 "	bne,pn		%%icc, 1b\n"
-"	 membar		#StoreLoad | #StoreStore\n"
+"	 nop\n"
 "	mov		1, %2\n"
 "2:"
 	: "=&r" (tmp1), "=&r" (tmp2), "=&r" (result)
--- a/include/asm-sparc64/spitfire.h
+++ b/include/asm-sparc64/spitfire.h
@ -111,7 +111,6 @@ static __inline__ void spitfire_put_dcache_tag(unsigned long addr, unsigned long
 			     "membar	#Sync"
 			     : /* No outputs */
 			     : "r" (tag), "r" (addr), "i" (ASI_DCACHE_TAG));
-	__asm__ __volatile__ ("membar #Sync" : : : "memory");
 }

 /* The instruction cache lines are flushed with this, but note that