[PATCH] ppc32: Allow adjust of pfn offset in pte
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@freescale.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-ppc/pgtable.h b/include/asm-ppc/pgtable.h
index 2e88cd9..e135b4a 100644
--- a/include/asm-ppc/pgtable.h
+++ b/include/asm-ppc/pgtable.h
@@ -431,10 +431,15 @@
* 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)
/*