Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Thu, 7 Apr 2005 14:26:05 -0500 (CDT) | From | Kumar Gala <> | Subject | [PATCH] ppc32: Allow adjust of pfn offset in pte |
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Andrew,
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>
---
diff -Nru a/include/asm-ppc/pgtable.h b/include/asm-ppc/pgtable.h --- a/include/asm-ppc/pgtable.h 2005-04-07 14:25:07 -05:00 +++ b/include/asm-ppc/pgtable.h 2005-04-07 14:25:07 -05:00 @@ -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) /* - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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