On Sat, 26 Mar 2011, Linus Torvalds wrote:
> Wouldn't something like the attached be better?
On first glance I cannot find fault with it.
arch/x86/include/asm/percpu.h | 10 ++++++----
1 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index a09e1f0..d475b43 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -45,7 +45,7 @@
#include <linux/stringify.h>
#ifdef CONFIG_SMP
-#define __percpu_arg(x) "%%"__stringify(__percpu_seg)":%P" #x
+#define __percpu_prefix "%%"__stringify(__percpu_seg)":"
#define __my_cpu_offset percpu_read(this_cpu_off)
/*
@@ -62,9 +62,11 @@
(typeof(*(ptr)) __kernel __force *)tcp_ptr__; \
})
#else
-#define __percpu_arg(x) "%P" #x
+#define __percpu_prefix ""
#endif
+#define __percpu_arg(x) __percpu_prefix "%P" #x
+
/*
* Initialized pointers to per-cpu variables needed for the boot
* processor need to use these macros to get the proper address
@@ -516,11 +518,11 @@ do { \
typeof(o2) __n2 = n2; \
typeof(o2) __dummy; \
alternative_io("call this_cpu_cmpxchg16b_emu\n\t" P6_NOP4, \
- "cmpxchg16b %%gs:(%%rsi)\n\tsetz %0\n\t", \
+ "cmpxchg16b " __percpu_prefix "(%%rsi)\n\tsetz %0\n\t", \
X86_FEATURE_CX16, \
ASM_OUTPUT2("=a"(__ret), "=d"(__dummy)), \
"S" (&pcp1), "b"(__n1), "c"(__n2), \
- "a"(__o1), "d"(__o2)); \
+ "a"(__o1), "d"(__o2) : "memory"); \
__ret; \
})