Commit 1d21f704 authored Jul 30, 2014 by Mark Charlebois Committed by Satya Durga Srinivasu Prabhala May 22, 2017

LLVMLINUX: DO-NOT-UPSTREAM arm64, LLVMLinux: prfm

Fix for prfm error on AArch64

The following error is generated with the mainline clang compiler
for AArch64:

arch/arm64/include/asm/processor.h:149:15:
error: invalid operand in inline asm: 'prfm pldl1keep, ${0:a}
'

Per comments by Tim Northover on the LLVM Bug database:

"It's rather unclear how it's better than "prfm pstl1keep, [%0]" though.
Not all instructions can make use of any offset, so wouldn't we have to be
conservative and always map it to "[xN]"?

When %a0 is changed to [%x0] it uncovered a GCC bug:
https://bugs.linaro.org/show_bug.cgi?id=635



Changing the "p" to "r" resolves the issue for both clang and GCC.

Change-Id: I833620cb2ed7ebb0bbd25da3b77624e06fe46a85
Signed-off-by: Mark Charlebois <charlebm@gmail.com>
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Git-commit: c3212ac08fa69652a7f8fb60121a9721d9a441d3
Git-repo: https://android.googlesource.com/kernel/common/


Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>

parent 94cec697

arch/arm64/include/asm/processor.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -167,13 +167,13 @@ extern struct task_struct cpu_switch_to(struct task_struct prev,
		#define ARCH_HAS_PREFETCH
		static inline void prefetch(const void *ptr)
		{
		asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
		asm volatile("prfm pldl1keep, [%x0]\n" : : "r" (ptr));
		}

		#define ARCH_HAS_PREFETCHW
		static inline void prefetchw(const void *ptr)
		{
		asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
		asm volatile("prfm pstl1keep, [%x0]\n" : : "r" (ptr));
		}

		#define ARCH_HAS_SPINLOCK_PREFETCH