[PATCH] perf tools: allow building for ARM (patch v2)

[Jamie Iles <jamie.iles@picochip.com>]

Add definitions of rmb() and cpu_relax() and include the ARM unistd.h
header. The __kuser_memory_barrier helper in the helper page is used to
provide the correct memory barrier depending on the CPU type.

Signed-off-by: Jamie Iles <jamie.iles@picochip.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mikael Pettersson <mikpe@it.uu.se>
---
 tools/perf/perf.h |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 454d5d5..75f941b 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -59,6 +59,18 @@
 #define cpu_relax()	asm volatile ("hint @pause" ::: "memory")
 #endif
 
+#ifdef __arm__
+#include "../../arch/arm/include/asm/unistd.h"
+/*
+ * Use the __kuser_memory_barrier helper in the CPU helper page. See
+ * arch/arm/kernel/entry-armv.S in the kernel source for details.
+ */
+#define rmb()		asm volatile("mov r0, #0xffff0fff; mov lr, pc;" \
+				     "sub pc, r0, #95" ::: "r0", "lr", "cc", \
+				     "memory")
+#define cpu_relax()	asm volatile("":::"memory")
+#endif
+
 #include <time.h>
 #include <unistd.h>
 #include <sys/types.h>
-- 
1.6.5.4