x86: provide symmetry between arm for cache_sync_instructions()

The arm architecture currently exports cache_sync_instructions()
in <arch/cache.h>. In order for rmodule loading to work on arm
architectures the cache_sync_instructions() needs to be called to
sequence the instruction cache. To avoid sprinkling #ifdefs around
just add an empty cache_sync_instructions() definition.

BUG=chrome-os-partner:27094
BRANCH=None
TEST=Built and booted nyan and rambi.

Original-Change-Id: I1a969757fffe0ca92754a0d953ba3630810556e3
Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/191551
Original-Reviewed-by: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit fda20947b928ee761d5ed15e414636af419970a6)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: I3e8ca12e1d82ccedf1ff9851ae3c5c80cda2dd5f
Reviewed-on: http://review.coreboot.org/7710
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/arch/x86/include/arch/cache.h

@@ -0,0 +1,41 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2014 Google Inc.
+ *
+ * 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_CACHE_H
+#define ARCH_CACHE_H
+
+/*
+ * For the purposes of the currently executing CPU loading code that will be
+ * run there aren't any cache coherency operations required. This just provides
+ * symmetry between architectures.
+ */
+static inline void cache_sync_instructions(void) {}
+
+#endif /* ARCH_CACHE_H */

src/lib/rmodule.c

@@ -20,6 +20,7 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
+#include <arch/cache.h>
 #include <console/console.h>
 #include <rmodule.h>
 
@@ -196,6 +197,9 @@ int rmodule_load(void *base, struct rmodule *module)
 	if (rmodule_relocate(module))
 		return -1;
 	rmodule_clear_bss(module);
+
+	cache_sync_instructions();
+
 	return 0;
 }