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Commit 35175033 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/mm: Introduce _PAGE_NA 



Today, PAGE_NONE is defined as a page not having _PAGE_USER.
In some circunstances, when the CPU supports it, it might be
better to be able to flag a page with NO ACCESS.

In a following patch, the 8xx will switch user access being flagged
in the PMD, therefore it will not be possible anymore to use
_PAGE_USER as a way to flag a page with no access.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 812fadcb

arch/powerpc/include/asm/book3s/64/pgtable.h

+1 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
 */

#define _PAGE_BIT_SWAP_TYPE	0



#define _PAGE_NA		0

#define _PAGE_RO		0

#define _PAGE_USER		0

arch/powerpc/include/asm/nohash/32/pgtable.h

+1 −1
Original line number Diff line number Diff line
@@ -282,7 +282,7 @@ static inline void __ptep_set_access_flags(struct mm_struct *mm, 
{

	unsigned long set = pte_val(entry) &

		(_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC);

	unsigned long clr = ~pte_val(entry) & _PAGE_RO;

	unsigned long clr = ~pte_val(entry) & (_PAGE_RO | _PAGE_NA);



	pte_update(ptep, clr, set);

}

arch/powerpc/include/asm/pte-common.h

+5 −2
Original line number Diff line number Diff line
@@ -50,6 +50,9 @@ 
#define _PAGE_USER 0

#endif

#endif

#ifndef _PAGE_NA

#define _PAGE_NA 0

#endif



#ifndef _PMD_PRESENT_MASK

#define _PMD_PRESENT_MASK	_PMD_PRESENT
@@ -122,7 +125,7 @@ static inline bool pte_user(pte_t pte) 
/* Mask of bits returned by pte_pgprot() */

#define PAGE_PROT_BITS	(_PAGE_GUARDED | _PAGE_COHERENT | _PAGE_NO_CACHE | \

			 _PAGE_WRITETHRU | _PAGE_ENDIAN | _PAGE_4K_PFN | \

			 _PAGE_USER | _PAGE_ACCESSED | _PAGE_RO | \

			 _PAGE_USER | _PAGE_ACCESSED | _PAGE_RO | _PAGE_NA | \

			 _PAGE_PRIVILEGED | \

			 _PAGE_RW | _PAGE_HWWRITE | _PAGE_DIRTY | _PAGE_EXEC)
@@ -150,7 +153,7 @@ static inline bool pte_user(pte_t pte) 
 *

 * Note due to the way vm flags are laid out, the bits are XWR

 */

#define PAGE_NONE	__pgprot(_PAGE_BASE)

#define PAGE_NONE	__pgprot(_PAGE_BASE | _PAGE_NA)

#define PAGE_SHARED	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)

#define PAGE_SHARED_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | \

				 _PAGE_EXEC)

arch/powerpc/mm/dump_linuxpagetables.c

+11 −7
Original line number Diff line number Diff line
@@ -117,16 +117,20 @@ static const struct flag_info flag_array[] = { 
		.set	= "user",

		.clear	= "    ",

	}, {

#if _PAGE_RO == 0

		.mask	= _PAGE_RW,

		.mask	= _PAGE_RW | _PAGE_RO | _PAGE_NA,

		.val	= _PAGE_RW,

#else

		.mask	= _PAGE_RO,

		.val	= 0,

#endif

		.set	= "rw",

		.clear	= "ro",

	}, {

		.mask	= _PAGE_RW | _PAGE_RO | _PAGE_NA,

		.val	= _PAGE_RO,

		.set	= "ro",

	}, {

#if _PAGE_NA != 0

		.mask	= _PAGE_RW | _PAGE_RO | _PAGE_NA,

		.val	= _PAGE_RO,

		.set	= "na",

	}, {

#endif

		.mask	= _PAGE_EXEC,

		.val	= _PAGE_EXEC,

		.set	= " X ",