armv7-m: add empty cache routines

armv7-m does not have cache but adding empty cache functions allow us to
transparently use code handling entering and leaving stages.

BUG=none
BRANCH=ToT
TEST=Built coreboot for cosmos
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>

Change-Id: Ief0c8a949e7e14d68473e7a093a8642d6058ccc6
Reviewed-on: https://chromium-review.googlesource.com/225206
Commit-Queue: Daisuke Nojiri <dnojiri@chromium.org>
Tested-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/arch/arm/armv7/Makefile.inc

@@ -53,6 +53,7 @@ bootblock-y += bootblock_m.S
 bootblock-y += bootblock_simple.c
 endif
 bootblock-y += exception_m.c
+bootblock-y += cache_m.c
 
 endif
 

src/arch/arm/armv7/cache_m.c

@@ -0,0 +1,79 @@
+/*
+ * 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.
+ *
+ * cache.c: Cache maintenance routines for ARMv7-M
+ */
+
+#include <stdint.h>
+
+#include <arch/cache.h>
+
+void tlb_invalidate_all(void)
+{
+}
+
+void dcache_clean_all(void)
+{
+}
+
+void dcache_clean_invalidate_all(void)
+{
+}
+
+void dcache_invalidate_all(void)
+{
+}
+
+unsigned int dcache_line_bytes(void)
+{
+	return 0;
+}
+
+void dcache_clean_by_mva(void const *addr, size_t len)
+{
+}
+
+void dcache_clean_invalidate_by_mva(void const *addr, size_t len)
+{
+}
+
+void dcache_invalidate_by_mva(void const *addr, size_t len)
+{
+}
+
+void dcache_mmu_disable(void)
+{
+}
+
+void dcache_mmu_enable(void)
+{
+}
+
+void cache_sync_instructions(void)
+{
+}