sh: Use more aggressive dcache purging in kmap teardown.

This fixes up a number of outstanding issues observed with old mappings
on the same colour hanging around. This requires some more optimal
handling, but is a safe fallback until all of the corner cases have been
handled.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/mm/cache.c b/arch/sh/mm/cache.c
index 8e4a8d1..35c37b7 100644
--- a/arch/sh/mm/cache.c
+++ b/arch/sh/mm/cache.c
@@ -97,7 +97,7 @@
 	}
 
 	if (pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
-		__flush_wback_region(vto, PAGE_SIZE);
+		__flush_purge_region(vto, PAGE_SIZE);
 
 	kunmap_atomic(vto, KM_USER1);
 	/* Make sure this page is cleared on other CPU's too before using it */
@@ -112,7 +112,7 @@
 	clear_page(kaddr);
 
 	if (pages_do_alias((unsigned long)kaddr, vaddr & PAGE_MASK))
-		__flush_wback_region(kaddr, PAGE_SIZE);
+		__flush_purge_region(kaddr, PAGE_SIZE);
 
 	kunmap_atomic(kaddr, KM_USER0);
 }
@@ -134,7 +134,7 @@
 			unsigned long addr = (unsigned long)page_address(page);
 
 			if (pages_do_alias(addr, address & PAGE_MASK))
-				__flush_wback_region((void *)addr, PAGE_SIZE);
+				__flush_purge_region((void *)addr, PAGE_SIZE);
 		}
 	}
 }
@@ -149,10 +149,11 @@
 			void *kaddr;
 
 			kaddr = kmap_coherent(page, vmaddr);
-			__flush_wback_region((void *)kaddr, PAGE_SIZE);
+			/* XXX.. For now kunmap_coherent() does a purge */
+			/* __flush_purge_region((void *)kaddr, PAGE_SIZE); */
 			kunmap_coherent(kaddr);
 		} else
-			__flush_wback_region((void *)addr, PAGE_SIZE);
+			__flush_purge_region((void *)addr, PAGE_SIZE);
 	}
 }