sh: Split out SH-4 __flush_xxx_region() ops.

This splits out the SH-4 __flush_xxx_region() functions and defines them
as weak symbols. This allows us to provide optimized versions without
having to ifdef cache-sh4.c to death.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/mm/flush-sh4.c

@@ -0,0 +1,63 @@
+#include <linux/mm.h>
+#include <asm/mmu_context.h>
+#include <asm/cacheflush.h>
+
+/*
+ * Write back the dirty D-caches, but not invalidate them.
+ *
+ * START: Virtual Address (U0, P1, or P3)
+ * SIZE: Size of the region.
+ */
+void __weak __flush_wback_region(void *start, int size)
+{
+	unsigned long v;
+	unsigned long begin, end;
+
+	begin = (unsigned long)start & ~(L1_CACHE_BYTES-1);
+	end = ((unsigned long)start + size + L1_CACHE_BYTES-1)
+		& ~(L1_CACHE_BYTES-1);
+	for (v = begin; v < end; v+=L1_CACHE_BYTES) {
+		asm volatile("ocbwb	%0"
+			     : /* no output */
+			     : "m" (__m(v)));
+	}
+}
+
+/*
+ * Write back the dirty D-caches and invalidate them.
+ *
+ * START: Virtual Address (U0, P1, or P3)
+ * SIZE: Size of the region.
+ */
+void __weak __flush_purge_region(void *start, int size)
+{
+	unsigned long v;
+	unsigned long begin, end;
+
+	begin = (unsigned long)start & ~(L1_CACHE_BYTES-1);
+	end = ((unsigned long)start + size + L1_CACHE_BYTES-1)
+		& ~(L1_CACHE_BYTES-1);
+	for (v = begin; v < end; v+=L1_CACHE_BYTES) {
+		asm volatile("ocbp	%0"
+			     : /* no output */
+			     : "m" (__m(v)));
+	}
+}
+
+/*
+ * No write back please
+ */
+void __weak __flush_invalidate_region(void *start, int size)
+{
+	unsigned long v;
+	unsigned long begin, end;
+
+	begin = (unsigned long)start & ~(L1_CACHE_BYTES-1);
+	end = ((unsigned long)start + size + L1_CACHE_BYTES-1)
+		& ~(L1_CACHE_BYTES-1);
+	for (v = begin; v < end; v+=L1_CACHE_BYTES) {
+		asm volatile("ocbi	%0"
+			     : /* no output */
+			     : "m" (__m(v)));
+	}
+}