[PATCH] m32r: Support pgprot_noncached()

This patch updates include/asm-m32r/pgtable.h to add pgprot_noncached().
It is required to fix a problem of an userspace application, which mmaps
io registers.

This patch also modifies drivers/video/fbmem.c to support noncachable
framebuffer access for m32r.
In this routine, pgprot_writecombine() is used hopefully, even though
the current m32r never does write-combining or write-coalescing...

Please apply this.

	* include/asm-m32r/pgtable.h
	  (pgprot_noncached, pgprot_writecombine): Newly added.

	* drivers/video/fbmem.c (fb_mmap): Add m32r support.
Signed-off-by: Mamoru Sakugawa <sakugawa@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/video/fbmem.c

@@ -938,7 +938,8 @@ fb_mmap(struct file *file, struct vm_area_struct * vma)
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 #elif defined(__hppa__)
 	pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE;
-#elif defined(__ia64__) || defined(__arm__) || defined(__sh__)
+#elif defined(__ia64__) || defined(__arm__) || defined(__sh__) || \
+      defined(__m32r__)
 	vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
 #else
 #warning What do we have to do here??

include/asm-m32r/pgtable.h

@@ -342,6 +342,19 @@ static __inline__ void ptep_mkdirty(pte_t *ptep)
 	set_bit(_PAGE_BIT_DIRTY, ptep);
 }
 
+/*
+ * Macro and implementation to make a page protection as uncachable.
+ */
+static __inline__ pgprot_t pgprot_noncached(pgprot_t _prot)
+{
+	unsigned long prot = pgprot_val(_prot);
+
+	prot |= _PAGE_NONCACHABLE;
+	return __pgprot(prot);
+}
+
+#define pgprot_writecombine(prot) pgprot_noncached(prot)
+
 /*
  * Conversion functions: convert a page and protection to a page entry,
  * and a page entry and page directory to the page they refer to.