From: Behan Webster <behanw@converseincode.com>
Date: Wed, 27 Aug 2014 04:29:29 +0000 (+0100)
Subject: arm64: LLVMLinux: Add current_stack_pointer() for arm64
X-Git-Tag: submit/tizen/20141203.153721~27
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c2bf6c3f3ee515ee0c0fa384c1177607f34c2858;p=platform%2Fkernel%2Flinux-arm64.git

arm64: LLVMLinux: Add current_stack_pointer() for arm64

Define a global named register for current_stack_pointer. The use of this new
variable guarantees that both gcc and clang can access this register in C code.

Signed-off-by: Behan Webster <behanw@converseincode.com>
Reviewed-by: Jan-Simon Möller <dl9pf@gmx.de>
Reviewed-by: Mark Charlebois <charlebm@gmail.com>
Reviewed-by: Olof Johansson <olof@lixom.net>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---

diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 0a8b2a97a32..0d754146d03 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -68,6 +68,11 @@ struct thread_info {
 #define init_thread_info	(init_thread_union.thread_info)
 #define init_stack		(init_thread_union.stack)
 
+/*
+ * how to get the current stack pointer from C
+ */
+register unsigned long current_stack_pointer asm ("sp");
+
 /*
  * how to get the thread information struct from C
  */