[PATCH V2 3/6] arm64: LLVMLinux: Calculate current_thread_info from current_stack_pointer

[behanw at converseincode.com]

From: Behan Webster <behanw at converseincode.com>

Use the global current_stack_pointer to get the value of the stack pointer.
This change supports being able to compile the kernel with both gcc and clang.

Signed-off-by: Behan Webster <behanw at converseincode.com>
Signed-off-by: Mark Charlebois <charlebm at gmail.com>
Reviewed-by: Jan-Simon Möller <dl9pf at gmx.de>
Reviewed-by: Olof Johansson <olof at lixom.net>
Acked-by: Will Deacon <will.deacon at arm.com>
---
 arch/arm64/include/asm/thread_info.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 356e037..459bf8e 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -80,8 +80,8 @@ static inline struct thread_info *current_thread_info(void) __attribute_const__;
 
 static inline struct thread_info *current_thread_info(void)
 {
-	register unsigned long sp asm ("sp");
-	return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
+	return (struct thread_info *)
+		(current_stack_pointer & ~(THREAD_SIZE - 1));
 }
 
 #define thread_saved_pc(tsk)	\
-- 
1.9.1