3 files changed, 46 insertions, 9 deletions

diff --git a/arch/mn10300/mm/Makefile b/arch/mn10300/mm/Makefile
index 28b9d983db0..1557277fbc5 100644
--- a/arch/mn10300/mm/Makefile
+++ b/arch/mn10300/mm/Makefile
@@ -2,13 +2,11 @@
 # Makefile for the MN10300-specific memory management code
 #
 
+cacheflush-y	:= cache.o cache-mn10300.o
+cacheflush-$(CONFIG_MN10300_CACHE_WBACK) += cache-flush-mn10300.o
+
+cacheflush-$(CONFIG_MN10300_CACHE_DISABLED) := cache-disabled.o
+
 obj-y := \
 	init.o fault.o pgtable.o extable.o tlb-mn10300.o mmu-context.o \
-	misalignment.o dma-alloc.o
-
-ifneq ($(CONFIG_MN10300_CACHE_DISABLED),y)
-obj-y	+= cache.o cache-mn10300.o
-ifeq ($(CONFIG_MN10300_CACHE_WBACK),y)
-obj-y	+= cache-flush-mn10300.o
-endif
-endif
+	misalignment.o dma-alloc.o $(cacheflush-y)
diff --git a/arch/mn10300/mm/cache-disabled.c b/arch/mn10300/mm/cache-disabled.c
new file mode 100644
index 00000000000..f669ea42aba
--- /dev/null
+++ b/arch/mn10300/mm/cache-disabled.c
@@ -0,0 +1,21 @@
+/* Handle the cache being disabled
+ *
+ * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#include <linux/mm.h>
+
+/*
+ * allow userspace to flush the instruction cache
+ */
+asmlinkage long sys_cacheflush(unsigned long start, unsigned long end)
+{
+	if (end < start)
+		return -EINVAL;
+	return 0;
+}
diff --git a/arch/mn10300/mm/cache.c b/arch/mn10300/mm/cache.c
index 1b76719ec1c..9261217e8d2 100644
--- a/arch/mn10300/mm/cache.c
+++ b/arch/mn10300/mm/cache.c
@@ -54,13 +54,30 @@ EXPORT_SYMBOL(flush_icache_page);
 void flush_icache_range(unsigned long start, unsigned long end)
 {
 #ifdef CONFIG_MN10300_CACHE_WBACK
-	unsigned long addr, size, off;
+	unsigned long addr, size, base, off;
 	struct page *page;
 	pgd_t *pgd;
 	pud_t *pud;
 	pmd_t *pmd;
 	pte_t *ppte, pte;
 
+	if (end > 0x80000000UL) {
+		/* addresses above 0xa0000000 do not go through the cache */
+		if (end > 0xa0000000UL) {
+			end = 0xa0000000UL;
+			if (start >= end)
+				return;
+		}
+
+		/* kernel addresses between 0x80000000 and 0x9fffffff do not
+		 * require page tables, so we just map such addresses directly */
+		base = (start >= 0x80000000UL) ? start : 0x80000000UL;
+		mn10300_dcache_flush_range(base, end);
+		if (base == start)
+			goto invalidate;
+		end = base;
+	}
+
 	for (; start < end; start += size) {
 		/* work out how much of the page to flush */
 		off = start & (PAGE_SIZE - 1);
@@ -104,6 +121,7 @@ void flush_icache_range(unsigned long start, unsigned long end)
 	}
 #endif
 
+invalidate:
 	mn10300_icache_inv();
 }
 EXPORT_SYMBOL(flush_icache_range);