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Commit 69660fd7 authored by Dan Williams's avatar Dan Williams Committed by Linus Torvalds
Browse files

x86, mm: introduce _PAGE_DEVMAP 



_PAGE_DEVMAP is a hardware-unused pte bit that will later be used in the
get_user_pages() path to identify pfns backed by the dynamic allocation
established by devm_memremap_pages.  Upon seeing that bit the gup path
will lookup and pin the allocation while the pages are in use.

Since the _PAGE_DEVMAP bit is > 32 it must be cast to u64 instead of a
pteval_t to allow pmd_flags() usage in the realmode boot code to build.

Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6d8113c7

arch/x86/include/asm/pgtable_types.h

+6 −1
Original line number Diff line number Diff line
@@ -24,6 +24,8 @@ 
#define _PAGE_BIT_CPA_TEST	_PAGE_BIT_SOFTW1

#define _PAGE_BIT_HIDDEN	_PAGE_BIT_SOFTW3 /* hidden by kmemcheck */

#define _PAGE_BIT_SOFT_DIRTY	_PAGE_BIT_SOFTW3 /* software dirty tracking */

#define _PAGE_BIT_SOFTW4	58	/* available for programmer */

#define _PAGE_BIT_DEVMAP		_PAGE_BIT_SOFTW4

#define _PAGE_BIT_NX		63	/* No execute: only valid after cpuid check */



/* If _PAGE_BIT_PRESENT is clear, we use these: */
@@ -83,8 +85,11 @@ 


#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)

#define _PAGE_NX	(_AT(pteval_t, 1) << _PAGE_BIT_NX)

#define _PAGE_DEVMAP	(_AT(u64, 1) << _PAGE_BIT_DEVMAP)

#define __HAVE_ARCH_PTE_DEVMAP

#else

#define _PAGE_NX	(_AT(pteval_t, 0))

#define _PAGE_DEVMAP	(_AT(pteval_t, 0))

#endif



#define _PAGE_PROTNONE	(_AT(pteval_t, 1) << _PAGE_BIT_PROTNONE)