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powerpc/mm: Introduce _PAGE_NA

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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: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Christophe Leroy 2018-01-12 13:45:29 +01:00 committed by Michael Ellerman
parent 812fadcb94
commit 351750331f
4 changed files with 18 additions and 10 deletions
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1
arch/powerpc/include/asm/book3s/64/pgtable.h
View File

@ -14,6 +14,7 @@
*/
#define _PAGE_BIT_SWAP_TYPE 0
#define _PAGE_NA 0
#define _PAGE_RO 0
#define _PAGE_USER 0

2
arch/powerpc/include/asm/nohash/32/pgtable.h
View File

@ -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);
}

7
arch/powerpc/include/asm/pte-common.h
View File

@ -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)

18
arch/powerpc/mm/dump_linuxpagetables.c
View File

@ -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 ",