From: Anton Blanchard Date: Fri, 31 Oct 2014 03:47:25 +0000 (+1100) Subject: powerpc: Don't use local named register variable in current_thread_info X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=a3e5b356b3ab40b00ecb0f6fde445db719c100b5;p=openwrt%2Fstaging%2Fblogic.git powerpc: Don't use local named register variable in current_thread_info LLVM doesn't support local named register variables and is unlikely to. current_thread_info is using one, fix it by moving it out and calling it __current_r1(). I gave it a bit of an obscure name because we don't want anyone else using it - they should use current_stack_pointer(). This specific case is performance critical and we can't afford to call a function to get it. Furthermore it isn't important to know exactly where in the stack we are since we mask the lower bits. Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman --- diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index b034ecdb7c74..ebc4f165690a 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h @@ -71,13 +71,12 @@ struct thread_info { #define THREAD_SIZE_ORDER (THREAD_SHIFT - PAGE_SHIFT) /* how to get the thread information struct from C */ +register unsigned long __current_r1 asm("r1"); static inline struct thread_info *current_thread_info(void) { - register unsigned long sp asm("r1"); - /* gcc4, at least, is smart enough to turn this into a single * rlwinm for ppc32 and clrrdi for ppc64 */ - return (struct thread_info *)(sp & ~(THREAD_SIZE-1)); + return (struct thread_info *)(__current_r1 & ~(THREAD_SIZE-1)); } #endif /* __ASSEMBLY__ */