[ CC:'ing Josh Grebe, he could reproduce these SMP hangs on
  his box quite reliably ]

Ok folks, give this patch a try.  It applies cleanly to
2.6.12 and 2.6.12.1

[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 <[EMAIL PROTECTED]>

diff --git a/arch/sparc64/kernel/entry.S b/arch/sparc64/kernel/entry.S
--- 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
diff --git a/arch/sparc64/kernel/semaphore.c b/arch/sparc64/kernel/semaphore.c
--- a/arch/sparc64/kernel/semaphore.c
+++ b/arch/sparc64/kernel/semaphore.c
@@ -32,8 +32,9 @@ static __inline__ int __sem_update_count
 "      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 se
 "      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"
diff --git a/arch/sparc64/kernel/trampoline.S b/arch/sparc64/kernel/trampoline.S
--- 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
diff --git a/arch/sparc64/lib/U1memcpy.S b/arch/sparc64/lib/U1memcpy.S
--- 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)
diff --git a/arch/sparc64/lib/VISsave.S b/arch/sparc64/lib/VISsave.S
--- 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
diff --git a/arch/sparc64/lib/atomic.S b/arch/sparc64/lib/atomic.S
--- 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 = at
         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 
        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 
        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, %o
        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, %o
        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
diff --git a/arch/sparc64/lib/bitops.S b/arch/sparc64/lib/bitops.S
--- a/arch/sparc64/lib/bitops.S
+++ b/arch/sparc64/lib/bitops.S
@@ -7,20 +7,26 @@
 #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
+#define BITOP_POST_BARRIER     \
+       ba,pt   %xcc, 80b;      \
+       membar #StoreLoad | #StoreStore
+
+80:    retl
+        nop
 #else
-#define BITOP_PRE_BARRIER      nop
-#define BITOP_POST_BARRIER     nop
+#define BITOP_PRE_BARRIER
+#define BITOP_POST_BARRIER
 #endif
 
-       .text
-
        .globl  test_and_set_bit
        .type   test_and_set_bit,#function
 test_and_set_bit:      /* %o0=nr, %o1=addr */
@@ -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
diff --git a/arch/sparc64/lib/debuglocks.c b/arch/sparc64/lib/debuglocks.c
--- 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, cha
 "              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");
diff --git a/arch/sparc64/lib/dec_and_lock.S b/arch/sparc64/lib/dec_and_lock.S
--- 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
         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
diff --git a/arch/sparc64/lib/rwsem.S b/arch/sparc64/lib/rwsem.S
--- 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
diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c
--- a/arch/sparc64/mm/init.c
+++ b/arch/sparc64/mm/init.c
@@ -136,8 +136,9 @@ static __inline__ void set_dcache_dirty(
                             "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_dirt
                             " 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),
diff --git a/arch/sparc64/mm/ultra.S b/arch/sparc64/mm/ultra.S
--- 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
diff --git a/include/asm-sparc64/rwsem.h b/include/asm-sparc64/rwsem.h
--- a/include/asm-sparc64/rwsem.h
+++ b/include/asm-sparc64/rwsem.h
@@ -55,8 +55,9 @@ static __inline__ int rwsem_atomic_updat
                "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)
diff --git a/include/asm-sparc64/spinlock.h b/include/asm-sparc64/spinlock.h
--- a/include/asm-sparc64/spinlock.h
+++ b/include/asm-sparc64/spinlock.h
@@ -52,12 +52,14 @@ static inline void _raw_spin_lock(spinlo
 
        __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(
 
        __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 
 "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
 "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
 "       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)
diff --git a/include/asm-sparc64/spitfire.h b/include/asm-sparc64/spitfire.h
--- a/include/asm-sparc64/spitfire.h
+++ b/include/asm-sparc64/spitfire.h
@@ -111,7 +111,6 @@ static __inline__ void spitfire_put_dcac
                             "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
-- 
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