From 23fc2cd7f185fdb2eb17fe73ff41c4a0141336a7 Mon Sep 17 00:00:00 2001
From: James Yang <46021128+jty2@users.noreply.github.com>
Date: Tue, 19 Oct 2021 03:42:43 +0000
Subject: [PATCH] lockhammer/prefetch64: do not dereference lock pointer

On aarch64, prefetch64() takes a pointer to the lock, but dereferences the
pointer as the address to prefetch.  Don't do that; it causes memory acceses to
a random memory location.  Instead, just pass the value of the pointer into the
PRFM instruction.
---
 benchmarks/lockhammer/include/atomics.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/benchmarks/lockhammer/include/atomics.h b/benchmarks/lockhammer/include/atomics.h
index c1ae409..8d3db7c 100644
--- a/benchmarks/lockhammer/include/atomics.h
+++ b/benchmarks/lockhammer/include/atomics.h
@@ -95,7 +95,7 @@ static inline void prefetch64 (unsigned long *ptr) {
 #if defined(__aarch64__)
 	asm volatile("	prfm	pstl1keep, %[ptr]\n"
 	:
-	: [ptr] "Q" (*(unsigned long *)ptr));
+	: [ptr] "Q" (ptr));
 #endif
 }