libpayload: Add support for memory barriers

Add support for memory barriers in arch {arm,arm64,x86}. This is required to
force strict CPU ordering. Definitions are based on FREEBSD atomic.h
definitions.

BUG=chrome-os-partner:31533
BRANCH=None
TEST=Memory barriers tested with ehci driver on arm64

Change-Id: I50060b0f33a6bd6cb95e829df079df379b2ff2a5
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 937d66cdab92a8521ede8307f5af8f5c20d3e552
Original-Change-Id: Ie51e3452f7a254b24111000da5dbe8714ac22223
Original-Signed-off-by: Furquan Shaikh <furquan@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/213916
Original-Tested-by: Furquan Shaikh <furquan@chromium.org>
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: http://review.coreboot.org/8731
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

2 files changed, 69 insertions, 15 deletions

diff --git a/payloads/libpayload/include/arm/arch/barrier.h b/payloads/libpayload/include/arm/arch/barrier.h
new file mode 100644
index 0000000000..fde55fa3c9
--- /dev/null
+++ b/payloads/libpayload/include/arm/arch/barrier.h
@@ -0,0 +1,66 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2014 Google Inc.
+ * Copyright (C) 2003-2004 Olivier Houchard
+ * Copyright (C) 1994-1997 Mark Brinicombe
+ * Copyright (C) 1994 Brini
+ * All rights reserved.
+ *
+ * This code is derived from software written for Brini by Mark Brinicombe
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+#ifndef __ARCH_BARRIER_H_
+#define __ARCH_BARRIER_H__
+
+#include <arch/cache.h>
+
+/*
+ * Description of different memory barriers introduced:
+ *
+ * Memory barrier(mb) - Guarantees that all memory accesses specified before the
+ * barrier will happen before all memory accesses specified after the barrier
+ *
+ * Read memory barrier (rmb) - Guarantees that all read memory accesses
+ * specified before the barrier will happen before all read memory accesses
+ * specified after the barrier
+ *
+ * Write memory barrier (wmb) - Guarantees that all write memory accesses
+ * specified before the barrier will happen before all write memory accesses
+ *  specified after the barrier
+ */
+
+/*
+ * According to ARM Reference Manual (ARMv7-A), by default dmb ensures:
+ * Full system is the required shareability domain
+ *  Reads and writes are the required access types.
+ */
+#define mb()       dmb()
+#define rmb()      dmb()
+#define wmb()      dmb()
+
+#endif /* __ARCH_BARRIER_H__ */
diff --git a/payloads/libpayload/include/arm/arch/cache.h b/payloads/libpayload/include/arm/arch/cache.h
index 647ec42ca2..67f6fd4492 100644
--- a/payloads/libpayload/include/arm/arch/cache.h
+++ b/payloads/libpayload/include/arm/arch/cache.h
@@ -70,24 +70,12 @@
 /*
  * Sync primitives
  */
-
 /* data memory barrier */
-static inline void dmb(void)
-{
-	asm volatile ("dmb" : : : "memory");
-}
-
+#define dmb() asm volatile ("dmb" : : : "memory")
 /* data sync barrier */
-static inline void dsb(void)
-{
-	asm volatile ("dsb" : : : "memory");
-}
-
+#define dsb() asm volatile ("dsb" : : : "memory")
 /* instruction sync barrier */
-static inline void isb(void)
-{
-	asm volatile ("isb" : : : "memory");
-}
+#define isb() asm volatile ("isb" : : : "memory")
 
 /*
  * Low-level TLB maintenance operations