[patch] pae: build fix

[patch] pae: build fix

[Gerd Knorr]

  Hi,

The patch below is needed to make pae-enabled xen build.  Not
sure why the intpte_t cast was added and whenever it is a good
idea to remove it.  Problem is that PAGE_MASK is used to
page-align both physical and virtual addresses, and the cast
causes build failures for the virtual address case.

Comments?

  Gerd

Index: xen/include/asm-x86/page.h
===================================================================
--- xen.orig/include/asm-x86/page.h	2005-06-20 12:45:29.000000000 +0200
+++ xen/include/asm-x86/page.h	2005-06-20 16:32:34.000000000 +0200
@@ -7,7 +7,8 @@
 #else
 #define PAGE_SIZE           (1 << PAGE_SHIFT)
 #endif
-#define PAGE_MASK           (~(intpte_t)(PAGE_SIZE-1))
+//#define PAGE_MASK           (~(intpte_t)(PAGE_SIZE-1))
+#define PAGE_MASK           (~(PAGE_SIZE-1))
 #define PAGE_FLAG_MASK      (~0U)
 
 #ifndef __ASSEMBLY__

Re: [patch] pae: build fix

[Keir Fraser]

On 22 Jun 2005, at 15:00, Gerd Knorr wrote:

> The patch below is needed to make pae-enabled xen build.  Not
> sure why the intpte_t cast was added and whenever it is a good
> idea to remove it.  Problem is that PAGE_MASK is used to
> page-align both physical and virtual addresses, and the cast
> causes build failures for the virtual address case.

I added the cast to ensure the mask was 64 bits wide, so that large 
physical addresses wouldn't get truncated to 32 bits when the mask is 
applied. I've fixed it to get the same effect a different way -- it's 
okay to have a narrower-type mask as long as it is signed (so it gets 
sign-extended if it has to be widened to 64 bits).

  -- Keir