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| author | David S. Miller <davem@davemloft.net> | 2010-08-19 07:53:26 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-08-19 07:53:26 +0200 |
| commit | 0f58189d4a3ca96d7959501ecb203177efdbc5bd (patch) | |
| tree | b5ad2f63da4c1caa5d20487cf370d51e4392111c /arch/sparc/lib/atomic_64.S | |
| parent | sparc64: simple microoptimizations for atomic functions (diff) | |
| download | linux-0f58189d4a3ca96d7959501ecb203177efdbc5bd.tar.xz linux-0f58189d4a3ca96d7959501ecb203177efdbc5bd.zip | |
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>
Diffstat (limited to 'arch/sparc/lib/atomic_64.S')
| -rw-r--r-- | arch/sparc/lib/atomic_64.S | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/arch/sparc/lib/atomic_64.S b/arch/sparc/lib/atomic_64.S index 703c9c3935b7..59186e0fcf39 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 |