From b791d1193af9772040e592d5aa161790f800b762 Mon Sep 17 00:00:00 2001 From: David Daney Date: Mon, 13 Jul 2009 11:15:19 -0700 Subject: MIPS: Allow kernel use of LL/SC to be separate from the presence of LL/SC. On some CPUs, it is more efficient to disable and enable interrupts in the kernel rather than use ll/sc for atomic operations. But if we were to set cpu_has_llsc to false, we would break the userspace futex interface (in asm/futex.h). We separate the two concepts, with a new predicate kernel_uses_llsc, that lets us disable the kernel's use of ll/sc while still allowing the futex code to use it. Also there were a couple of cases in bitops.h where we were using ll/sc unconditionally even if cpu_has_llsc were false. Signed-off-by: David Daney Signed-off-by: Ralf Baechle --- arch/mips/include/asm/cmpxchg.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/mips/include/asm/cmpxchg.h') diff --git a/arch/mips/include/asm/cmpxchg.h b/arch/mips/include/asm/cmpxchg.h index 4a812c3ceb90..815a438a268d 100644 --- a/arch/mips/include/asm/cmpxchg.h +++ b/arch/mips/include/asm/cmpxchg.h @@ -16,7 +16,7 @@ ({ \ __typeof(*(m)) __ret; \ \ - if (cpu_has_llsc && R10000_LLSC_WAR) { \ + if (kernel_uses_llsc && R10000_LLSC_WAR) { \ __asm__ __volatile__( \ " .set push \n" \ " .set noat \n" \ @@ -33,7 +33,7 @@ : "=&r" (__ret), "=R" (*m) \ : "R" (*m), "Jr" (old), "Jr" (new) \ : "memory"); \ - } else if (cpu_has_llsc) { \ + } else if (kernel_uses_llsc) { \ __asm__ __volatile__( \ " .set push \n" \ " .set noat \n" \ -- cgit v1.2.3