arm926ejs: add noop implementation for dcache ops

Added noop implementation for dcache operations that will buzz
about missing real implementation and disable the dcache.
This fixes compilation of DaVinci EMAC driver on arm926ejs.

Signed-off-by: Ilya Yanok <yanok@emcraft.com>

arch/arm/cpu/arm926ejs/Makefile

@@ -26,7 +26,7 @@ include $(TOPDIR)/config.mk
 LIB	= $(obj)lib$(CPU).o
 
 START	= start.o
-COBJS	= cpu.o
+COBJS	= cpu.o cache.o
 
 ifdef	CONFIG_SPL_BUILD
 ifdef	CONFIG_SPL_NO_CPU_SUPPORT_CODE

arch/arm/cpu/arm926ejs/cache.c

@@ -0,0 +1,75 @@
+/*
+ * (C) Copyright 2011
+ * Ilya Yanok, EmCraft Systems
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc.
+ */
+#include <linux/types.h>
+#include <common.h>
+
+#ifndef CONFIG_SYS_DCACHE_OFF
+static inline void dcache_noop(void)
+{
+	if (dcache_status()) {
+		puts("WARNING: cache operations are not implemented!\n"
+		     "WARNING: disabling D-Cache now, you can re-enable it"
+		     "later with 'dcache on' command\n");
+		dcache_disable();
+	}
+}
+
+void invalidate_dcache_all(void)
+{
+	dcache_noop();
+}
+
+void flush_dcache_all(void)
+{
+	dcache_noop();
+}
+
+void invalidate_dcache_range(unsigned long start, unsigned long stop)
+{
+	dcache_noop();
+}
+
+void flush_dcache_range(unsigned long start, unsigned long stop)
+{
+	dcache_noop();
+}
+#else /* #ifndef CONFIG_SYS_DCACHE_OFF */
+void invalidate_dcache_all(void)
+{
+}
+
+void flush_dcache_all(void)
+{
+}
+
+void invalidate_dcache_range(unsigned long start, unsigned long stop)
+{
+}
+
+void flush_dcache_range(unsigned long start, unsigned long stop)
+{
+}
+
+void  flush_cache(unsigned long start, unsigned long size)
+{
+}
+#endif /* #ifndef CONFIG_SYS_DCACHE_OFF */