m68k: fix ColdFire clear cache operation

The code for clearing (invalidating) the ColdFire cache is actually performing
a push operation. Add functions to clear the cache, and fix cache_clear() to
call the appropriate clear cache function.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>

arch/m68k/include/asm/cacheflush_mm.h

@@ -16,7 +16,48 @@
 #define DCACHE_MAX_ADDR	0
 #define DCACHE_SETMASK	0
 #endif
+#ifndef CACHE_MODE
+#define	CACHE_MODE	0
+#define	CACR_ICINVA	0
+#define	CACR_DCINVA	0
+#define	CACR_BCINVA	0
+#endif
+
+/*
+ * ColdFire architecture has no way to clear individual cache lines, so we
+ * are stuck invalidating all the cache entries when we want a clear operation.
+ */
+static inline void clear_cf_icache(unsigned long start, unsigned long end)
+{
+	__asm__ __volatile__ (
+		"movec	%0,%%cacr\n\t"
+		"nop"
+		:
+		: "r" (CACHE_MODE | CACR_ICINVA | CACR_BCINVA));
+}
+
+static inline void clear_cf_dcache(unsigned long start, unsigned long end)
+{
+	__asm__ __volatile__ (
+		"movec	%0,%%cacr\n\t"
+		"nop"
+		:
+		: "r" (CACHE_MODE | CACR_DCINVA));
+}
 
+static inline void clear_cf_bcache(unsigned long start, unsigned long end)
+{
+	__asm__ __volatile__ (
+		"movec	%0,%%cacr\n\t"
+		"nop"
+		:
+		: "r" (CACHE_MODE | CACR_ICINVA | CACR_BCINVA | CACR_DCINVA));
+}
+
+/*
+ * Use the ColdFire cpushl instruction to push (and invalidate) cache lines.
+ * The start and end addresses are cache line numbers not memory addresses.
+ */
 static inline void flush_cf_icache(unsigned long start, unsigned long end)
 {
 	unsigned long set;

arch/m68k/mm/memory.c

@@ -203,7 +203,7 @@ static inline void pushcl040(unsigned long paddr)
 void cache_clear (unsigned long paddr, int len)
 {
     if (CPU_IS_COLDFIRE) {
-	flush_cf_bcache(0, DCACHE_MAX_ADDR);
+	clear_cf_bcache(0, DCACHE_MAX_ADDR);
     } else if (CPU_IS_040_OR_060) {
 	int tmp;