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Commit bf950040 authored by Will Deacon's avatar Will Deacon
Browse files

arm64: pgtable: use a single bit for PTE_WRITE regardless of DBM 



Depending on CONFIG_ARM64_HW_AFDBM, we use either bit 57 or 51 of the
pte to represent PTE_WRITE. Given that bit 51 is reserved prior to
ARMv8.1, we can just use that bit regardless of the config option. That
also matches what happens if a kernel configured with ARM64_HW_AFDBM=y
is run on a CPU without the DBM functionality.

Cc: Julien Grall <julien.grall@citrix.com>
Tested-by: default avatarJulien Grall <julien.grall@citrix.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 62d96c71

arch/arm64/include/asm/pgtable.h

+1 −5
Original line number Diff line number Diff line
@@ -26,13 +26,9 @@ 
 * Software defined PTE bits definition.

 */

#define PTE_VALID		(_AT(pteval_t, 1) << 0)

#define PTE_WRITE		(PTE_DBM)		 /* same as DBM (51) */

#define PTE_DIRTY		(_AT(pteval_t, 1) << 55)

#define PTE_SPECIAL		(_AT(pteval_t, 1) << 56)

#ifdef CONFIG_ARM64_HW_AFDBM

#define PTE_WRITE		(PTE_DBM)		 /* same as DBM */

#else

#define PTE_WRITE		(_AT(pteval_t, 1) << 57)

#endif

#define PTE_PROT_NONE		(_AT(pteval_t, 1) << 58) /* only when !PTE_VALID */



/*