diff options
| author | David S. Miller <davem@davemloft.net> | 2010-08-18 22:53:26 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-08-18 22:53:26 -0700 |
| commit | 0f58189d4a3ca96d7959501ecb203177efdbc5bd (patch) | |
| tree | b5ad2f63da4c1caa5d20487cf370d51e4392111c | |
| parent | 6ec274750c99448c3412bbc10c97ce0c993f8a4e (diff) | |
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>
| -rw-r--r-- | arch/sparc/include/asm/backoff.h | 11 | ||||
| -rw-r--r-- | arch/sparc/lib/atomic_64.S | 16 | ||||
| -rw-r--r-- | arch/sparc/lib/bitops.S | 12 |
3 files changed, 22 insertions, 17 deletions
diff --git a/arch/sparc/include/asm/backoff.h b/arch/sparc/include/asm/backoff.h index fa1fdf67e35..db3af0d30fb 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 703c9c3935b..59186e0fcf3 100644 --- a/arch/sparc/lib/atomic_64.S +++ b/arch/sparc/lib/atomic_64.S @@ -21,7 +21,7 @@ atomic_add: /* %o0 = increment, %o1 = atomic_ptr */ 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 @@ atomic_sub: /* %o0 = decrement, %o1 = atomic_ptr */ 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 @@ atomic_add_ret: /* %o0 = increment, %o1 = atomic_ptr */ 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 @@ atomic_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */ 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 @@ atomic64_add: /* %o0 = increment, %o1 = atomic_ptr */ 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 @@ atomic64_sub: /* %o0 = decrement, %o1 = atomic_ptr */ 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 @@ atomic64_add_ret: /* %o0 = increment, %o1 = atomic_ptr */ 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 @@ atomic64_sub_ret: /* %o0 = decrement, %o1 = atomic_ptr */ 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 2b7228cb8c2..3dc61d5537c 100644 --- a/arch/sparc/lib/bitops.S +++ b/arch/sparc/lib/bitops.S @@ -22,7 +22,7 @@ test_and_set_bit: /* %o0=nr, %o1=addr */ 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 @@ test_and_clear_bit: /* %o0=nr, %o1=addr */ 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 @@ test_and_change_bit: /* %o0=nr, %o1=addr */ 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 @@ set_bit: /* %o0=nr, %o1=addr */ 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 @@ clear_bit: /* %o0=nr, %o1=addr */ 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 @@ change_bit: /* %o0=nr, %o1=addr */ 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 |