From be43d72835ba610e4af274f2d123b26f66f4f7ed Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Sun, 7 Sep 2008 15:21:13 -0700 Subject: x86: add _PAGE_IOMAP pte flag for IO mappings Use one of the software-defined PTE bits to indicate that a mapping is intended for an IO address. On native hardware this is irrelevent, since a physical address is a physical address. But in a virtual environment, physical addresses are also virtualized, so there needs to be some way to distinguish between pseudo-physical addresses and actual hardware addresses; _PAGE_IOMAP indicates this intent. By default, __supported_pte_mask masks out _PAGE_IOMAP, so it doesn't even appear in the final pagetable. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Ingo Molnar --- arch/x86/mm/init_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/mm/init_64.c') diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 3e10054c573..dec5c775e92 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -89,7 +89,7 @@ early_param("gbpages", parse_direct_gbpages_on); int after_bootmem; -unsigned long __supported_pte_mask __read_mostly = ~0UL; +pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP; EXPORT_SYMBOL_GPL(__supported_pte_mask); static int do_not_nx __cpuinitdata; -- cgit v1.2.3