Re: [PATCH] Fix mmap_kmem (was: [question] What's the difference between /dev/kmem and /dev/mem)

Jeff Dike
2005-08-15T21:25:50Z

On Mon, Aug 15, 2005 at 09:33:07PM +0200, Olaf Hering wrote:
> ARCH=um doesnt like your version, but mine.
>
> drivers/char/mem.c:267: error: invalid operands to binary <<
>
> pfn = (__pa((u64)vma->vm_pgoff) << PAGE_SHIFT) >> PAGE_SHIFT;

My page.h was missing some parens. Try the patch below.

Jeff

Index: linux-2.6.13-rc6/include/asm-um/page.h
===================================================================
--- linux-2.6.13-rc6.orig/include/asm-um/page.h 2005-08-15 16:57:55.000000000 -0400
+++ linux-2.6.13-rc6/include/asm-um/page.h 2005-08-15 17:16:57.000000000 -0400
@@ -104,8 +104,8 @@
* casting is the right thing, but 32-bit UML can't have 64-bit virtual
* addresses
*/
-#define __pa(virt) to_phys((void *) (unsigned long) virt)
-#define __va(phys) to_virt((unsigned long) phys)
+#define __pa(virt) to_phys((void *) (unsigned long) (virt))
+#define __va(phys) to_virt((unsigned long) (phys))

#define page_to_pfn(page) ((page) - mem_map)
#define pfn_to_page(pfn) (mem_map + (pfn))