sparc64: Stop using memory barriers for atomics and locks.

The kernel always executes in the TSO memory model now,
so none of this stuff is necessary any more.

With helpful feedback from Nick Piggin.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 24 deletions

diff --git a/arch/sparc64/lib/bitops.S b/arch/sparc64/lib/bitops.S
index 6b015a6eefb5..2b7228cb8c22 100644
--- a/arch/sparc64/lib/bitops.S
+++ b/arch/sparc64/lib/bitops.S
@@ -8,29 +8,10 @@
 
         .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      \
-        ba,pt   %xcc, 80b;      \
-        membar #StoreLoad | #StoreStore
-
-80:     retl
-         nop
-#else
-#define BITOP_PRE_BARRIER
-#define BITOP_POST_BARRIER
-#endif
-
         .globl  test_and_set_bit
         .type   test_and_set_bit,#function
 test_and_set_bit:       /* %o0=nr, %o1=addr */
         BACKOFF_SETUP(%o3)
-        BITOP_PRE_BARRIER
         srlx    %o0, 6, %g1
         mov     1, %o2
         sllx    %g1, 3, %g3
@@ -45,7 +26,6 @@ test_and_set_bit:	/* %o0=nr, %o1=addr */
          and    %g7, %o2, %g2
         clr     %o0
         movrne  %g2, 1, %o0
-        BITOP_POST_BARRIER
         retl
          nop
 2:      BACKOFF_SPIN(%o3, %o4, 1b)
@@ -55,7 +35,6 @@ test_and_set_bit:	/* %o0=nr, %o1=addr */
         .type   test_and_clear_bit,#function
 test_and_clear_bit:     /* %o0=nr, %o1=addr */
         BACKOFF_SETUP(%o3)
-        BITOP_PRE_BARRIER
         srlx    %o0, 6, %g1
         mov     1, %o2
         sllx    %g1, 3, %g3
@@ -70,7 +49,6 @@ test_and_clear_bit:	/* %o0=nr, %o1=addr */
          and    %g7, %o2, %g2
         clr     %o0
         movrne  %g2, 1, %o0
-        BITOP_POST_BARRIER
         retl
          nop
 2:      BACKOFF_SPIN(%o3, %o4, 1b)
@@ -80,7 +58,6 @@ test_and_clear_bit:	/* %o0=nr, %o1=addr */
         .type   test_and_change_bit,#function
 test_and_change_bit:    /* %o0=nr, %o1=addr */
         BACKOFF_SETUP(%o3)
-        BITOP_PRE_BARRIER
         srlx    %o0, 6, %g1
         mov     1, %o2
         sllx    %g1, 3, %g3
@@ -95,7 +72,6 @@ test_and_change_bit:	/* %o0=nr, %o1=addr */
          and    %g7, %o2, %g2
         clr     %o0
         movrne  %g2, 1, %o0
-        BITOP_POST_BARRIER
         retl
          nop
 2:      BACKOFF_SPIN(%o3, %o4, 1b)