sh: Support explicit L1 cache disabling.

This reworks the cache mode configuration in Kconfig, and allows for
explicit selection of write-back/write-through/off configurations.
All of the cache flushing routines are optimized away for the off
case.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/include/asm-sh/page.h b/include/asm-sh/page.h
index 6bc9bba..48b718e 100644
--- a/include/asm-sh/page.h
+++ b/include/asm-sh/page.h
@@ -70,14 +70,14 @@
 extern void copy_page_nommu(void *to, void *from);
 #endif
 
-#if defined(CONFIG_MMU) && (defined(CONFIG_CPU_SH4) || \
-	defined(CONFIG_SH7705_CACHE_32KB))
+#if !defined(CONFIG_CACHE_OFF) && defined(CONFIG_MMU) && \
+	(defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB))
 struct page;
 extern void clear_user_page(void *to, unsigned long address, struct page *pg);
 extern void copy_user_page(void *to, void *from, unsigned long address, struct page *pg);
 extern void __clear_user_page(void *to, void *orig_to);
 extern void __copy_user_page(void *to, void *from, void *orig_to);
-#elif defined(CONFIG_CPU_SH2) || defined(CONFIG_CPU_SH3) || !defined(CONFIG_MMU)
+#else
 #define clear_user_page(page, vaddr, pg)	clear_page(page)
 #define copy_user_page(to, from, vaddr, pg)	copy_page(to, from)
 #endif