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>

2 files changed, 42 insertions, 1 deletions

diff --git a/arch/m68k/include/asm/cacheflush_mm.h b/arch/m68k/include/asm/cacheflush_mm.h
index 8104bd874649..fa2c3d681d84 100644
--- a/arch/m68k/include/asm/cacheflush_mm.h
+++ b/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;
diff --git a/arch/m68k/mm/memory.c b/arch/m68k/mm/memory.c
index 250b8b786f4f..51bc9d258ede 100644
--- a/arch/m68k/mm/memory.c
+++ b/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;