x86: implement pte_special
authorNick Piggin <npiggin@suse.de>
Sat, 26 Jul 2008 02:45:20 +0000 (19:45 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 26 Jul 2008 19:00:05 +0000 (12:00 -0700)
commita0a8f5364a5ad248aec6cb705e0092ff563edc2f
treefe942b13adc527f66103d529c2ee91da05086d1c
parent2682497245e7d22160ae63032c378745a7f2cfe5
x86: implement pte_special

Implement the pte_special bit for x86.  This is required to support
lockless get_user_pages, because we need to know whether or not we can
refcount a particular page given only its pte (and no vma).

[hugh@veritas.com: fix a BUG]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/asm-x86/pgtable.h