From 0f58189d4a3ca96d7959501ecb203177efdbc5bd Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 18 Aug 2010 22:53:26 -0700 Subject: 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 --- arch/sparc/include/asm/backoff.h | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'arch/sparc/include/asm') diff --git a/arch/sparc/include/asm/backoff.h b/arch/sparc/include/asm/backoff.h index fa1fdf67e350..db3af0d30fb1 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 -- cgit v1.2.3