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| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2008-09-07 15:21:13 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-10-13 10:20:56 +0200 |
| commit | be43d72835ba610e4af274f2d123b26f66f4f7ed (patch) | |
| tree | 004fe651aff85c6cfae6a174217b05d948b7cf6d /arch/x86/mm/init_32.c | |
| parent | 07bb2f6236f11169fbd8a8916b16715b25fea9b6 (diff) | |
| download | linux-be43d72835ba610e4af274f2d123b26f66f4f7ed.tar.gz linux-be43d72835ba610e4af274f2d123b26f66f4f7ed.tar.bz2 linux-be43d72835ba610e4af274f2d123b26f66f4f7ed.zip | |
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 <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/mm/init_32.c')
| -rw-r--r-- | arch/x86/mm/init_32.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index bbe044dbe014..8396868e82c5 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -558,7 +558,7 @@ void zap_low_mappings(void) int nx_enabled; -pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL); +pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP); EXPORT_SYMBOL_GPL(__supported_pte_mask); #ifdef CONFIG_X86_PAE |