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.le...@c-s.fr>
---
arch/powerpc/include/asm/book3s/64/pgtable.h | 1 +
arch/powerpc/include/asm/nohash/32/pgtable.h | 2 +-
arch/powerpc/include/asm/pte-common.h | 7 +++++--
arch/powerpc/mm/dump_linuxpagetables.c | 18 +++++++++++-------
4 files changed, 18 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h
b/arch/powerpc/include/asm/book3s/64/pgtable.h
index db38050e1a98..f1c43d9b0773 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -14,6 +14,7 @@
*/
#define _PAGE_BIT_SWAP_TYPE 0
+#define _PAGE_NA 0
#define _PAGE_RO 0
#define _PAGE_USER 0
diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h
b/arch/powerpc/include/asm/nohash/32/pgtable.h
index cc2bfec3aa3b..504a3c36ce5c 100644
--- a/arch/powerpc/include/asm/nohash/32/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/32/pgtable.h
@@ -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);
}
diff --git a/arch/powerpc/include/asm/pte-common.h
b/arch/powerpc/include/asm/pte-common.h
index 0e6595a1b9d8..426a902816c5 100644
--- a/arch/powerpc/include/asm/pte-common.h
+++ b/arch/powerpc/include/asm/pte-common.h
@@ -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)
diff --git a/arch/powerpc/mm/dump_linuxpagetables.c
b/arch/powerpc/mm/dump_linuxpagetables.c
index d9547e1ec5ef..4e8c6e593276 100644
--- a/arch/powerpc/mm/dump_linuxpagetables.c
+++ b/arch/powerpc/mm/dump_linuxpagetables.c
@@ -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 ",
--
2.13.3
