x86: CLFLUSH and cache line size detection

Detect the presence of CLFLUSH instruction and cache line size at
runtime. It is still possible to set them manually via kconfig options
if the values are known.

Change-Id: I00bda1de4c5c241826ead6f43b887b99a963cc7b
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>

include/cache.h

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2015 Wind River Systems, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _cache__h_
+#define _cache__h_
+
+#include <nanokernel.h>
+
+#if defined(CONFIG_CACHE_FLUSHING)
+#define _sys_cache_flush_sig(x) void (x)(vaddr_t virt, size_t size)
+
+#if defined(CONFIG_ARCH_CACHE_FLUSH_DETECT)
+	typedef _sys_cache_flush_sig(_sys_cache_flush_t);
+	extern _sys_cache_flush_t *sys_cache_flush;
+#else
+	extern _sys_cache_flush_sig(sys_cache_flush);
+#endif
+#endif /* CACHE_FLUSHING */
+
+#if defined(CONFIG_CACHE_LINE_SIZE_DETECT)
+	extern size_t sys_cache_line_size;
+#else
+	#define sys_cache_line_size CONFIG_CACHE_LINE_SIZE
+#endif
+
+#endif /* _cache__h_ */