[patch 034/198] ppc32: Allow adjust of pfn offset in pte

[akpm]

From: Kumar Gala <galak@xxxxxxxxxxxxx>

Allow the pfn to be offset by more than just PAGE_SHIFT in the pte.  Today,
PAGE_SHIFT tends to allow us to have 12-bits of flags in the pte.  In the
future if we have a larger pte we can allocate more bits for flags by
offsetting the pfn even further.

Signed-off-by: Kumar Gala <kumar.gala@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---

 25-akpm/include/asm-ppc/pgtable.h |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff -puN include/asm-ppc/pgtable.h~ppc32-allow-adjust-of-pfn-offset-in-pte include/asm-ppc/pgtable.h
--- 25/include/asm-ppc/pgtable.h~ppc32-allow-adjust-of-pfn-offset-in-pte	2005-04-12 03:21:11.573377480 -0700
+++ 25-akpm/include/asm-ppc/pgtable.h	2005-04-12 03:21:11.576377024 -0700
@@ -431,10 +431,15 @@ extern unsigned long bad_call_to_PMD_PAG
  * Conversions between PTE values and page frame numbers.
  */
 
-#define pte_pfn(x)		(pte_val(x) >> PAGE_SHIFT)
+/* in some case we want to additionaly adjust where the pfn is in the pte to
+ * allow room for more flags */
+#define PFN_SHIFT_OFFSET	(PAGE_SHIFT)
+
+#define pte_pfn(x)		(pte_val(x) >> PFN_SHIFT_OFFSET)
 #define pte_page(x)		pfn_to_page(pte_pfn(x))
 
-#define pfn_pte(pfn, prot)	__pte(((pte_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
+#define pfn_pte(pfn, prot)	__pte(((pte_basic_t)(pfn) << PFN_SHIFT_OFFSET) |\
+					pgprot_val(prot))
 #define mk_pte(page, prot)	pfn_pte(page_to_pfn(page), prot)
 
 /*
_
-
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