sparc64: Make lock backoff really a NOP on UP builds.
As noticed by Mikulas Patocka, the backoff macros don't
completely nop out for UP builds, we still get a
branch always and a delay slot nop.
Fix this by making the branch to the backoff spin loop
selective, then we can nop out the spin loop completely.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/include/asm/backoff.h b/arch/sparc/include/asm/backoff.h
index fa1fdf6..db3af0d 100644
--- a/arch/sparc/include/asm/backoff.h
+++ b/arch/sparc/include/asm/backoff.h
@@ -8,6 +8,9 @@
#define BACKOFF_SETUP(reg) \
mov 1, reg
+#define BACKOFF_LABEL(spin_label, continue_label) \
+ spin_label
+
#define BACKOFF_SPIN(reg, tmp, label) \
mov reg, tmp; \
88: brnz,pt tmp, 88b; \
@@ -22,9 +25,11 @@
#else
#define BACKOFF_SETUP(reg)
-#define BACKOFF_SPIN(reg, tmp, label) \
- ba,pt %xcc, label; \
- nop;
+
+#define BACKOFF_LABEL(spin_label, continue_label) \
+ continue_label
+
+#define BACKOFF_SPIN(reg, tmp, label)
#endif
diff --git a/arch/sparc/lib/atomic_64.S b/arch/sparc/lib/atomic_64.S
index 703c9c3..59186e0 100644
--- a/arch/sparc/lib/atomic_64.S
+++ b/arch/sparc/lib/atomic_64.S
@@ -21,7 +21,7 @@
add %g1, %o0, %g7
cas [%o1], %g1, %g7
cmp %g1, %g7
- bne,pn %icc, 2f
+ bne,pn %icc, BACKOFF_LABEL(2f, 1b)
nop
retl
nop
@@ -36,7 +36,7 @@
sub %g1, %o0, %g7
cas [%o1], %g1, %g7
cmp %g1, %g7
- bne,pn %icc, 2f
+ bne,pn %icc, BACKOFF_LABEL(2f, 1b)
nop
retl
nop
@@ -51,7 +51,7 @@
add %g1, %o0, %g7
cas [%o1], %g1, %g7
cmp %g1, %g7
- bne,pn %icc, 2f
+ bne,pn %icc, BACKOFF_LABEL(2f, 1b)
add %g1, %o0, %g1
retl
sra %g1, 0, %o0
@@ -66,7 +66,7 @@
sub %g1, %o0, %g7
cas [%o1], %g1, %g7
cmp %g1, %g7
- bne,pn %icc, 2f
+ bne,pn %icc, BACKOFF_LABEL(2f, 1b)
sub %g1, %o0, %g1
retl
sra %g1, 0, %o0
@@ -81,7 +81,7 @@
add %g1, %o0, %g7
casx [%o1], %g1, %g7
cmp %g1, %g7
- bne,pn %xcc, 2f
+ bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
nop
retl
nop
@@ -96,7 +96,7 @@
sub %g1, %o0, %g7
casx [%o1], %g1, %g7
cmp %g1, %g7
- bne,pn %xcc, 2f
+ bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
nop
retl
nop
@@ -111,7 +111,7 @@
add %g1, %o0, %g7
casx [%o1], %g1, %g7
cmp %g1, %g7
- bne,pn %xcc, 2f
+ bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
nop
retl
add %g1, %o0, %o0
@@ -126,7 +126,7 @@
sub %g1, %o0, %g7
casx [%o1], %g1, %g7
cmp %g1, %g7
- bne,pn %xcc, 2f
+ bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
nop
retl
sub %g1, %o0, %o0
diff --git a/arch/sparc/lib/bitops.S b/arch/sparc/lib/bitops.S
index 2b7228c..3dc61d5 100644
--- a/arch/sparc/lib/bitops.S
+++ b/arch/sparc/lib/bitops.S
@@ -22,7 +22,7 @@
or %g7, %o2, %g1
casx [%o1], %g7, %g1
cmp %g7, %g1
- bne,pn %xcc, 2f
+ bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
and %g7, %o2, %g2
clr %o0
movrne %g2, 1, %o0
@@ -45,7 +45,7 @@
andn %g7, %o2, %g1
casx [%o1], %g7, %g1
cmp %g7, %g1
- bne,pn %xcc, 2f
+ bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
and %g7, %o2, %g2
clr %o0
movrne %g2, 1, %o0
@@ -68,7 +68,7 @@
xor %g7, %o2, %g1
casx [%o1], %g7, %g1
cmp %g7, %g1
- bne,pn %xcc, 2f
+ bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
and %g7, %o2, %g2
clr %o0
movrne %g2, 1, %o0
@@ -91,7 +91,7 @@
or %g7, %o2, %g1
casx [%o1], %g7, %g1
cmp %g7, %g1
- bne,pn %xcc, 2f
+ bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
nop
retl
nop
@@ -112,7 +112,7 @@
andn %g7, %o2, %g1
casx [%o1], %g7, %g1
cmp %g7, %g1
- bne,pn %xcc, 2f
+ bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
nop
retl
nop
@@ -133,7 +133,7 @@
xor %g7, %o2, %g1
casx [%o1], %g7, %g1
cmp %g7, %g1
- bne,pn %xcc, 2f
+ bne,pn %xcc, BACKOFF_LABEL(2f, 1b)
nop
retl
nop