[PATCH 7/9] powerpc/mm/book3s-64: Shuffle read, write, execute and user bits in PTE
Paul Mackerras
paulus at ozlabs.org
Mon Feb 22 13:41:18 AEDT 2016
From: Paul Mackerras <paulus at samba.org>
This moves the _PAGE_EXEC, _PAGE_RW and _PAGE_USER bits around in
the Linux PTE on 64-bit Book 3S systems to correspond with the bit
positions used in radix mode by PowerISA v3.0 CPUs. This also adds
a _PAGE_READ bit corresponding to the read permission bit in the
radix PTE. _PAGE_READ is currently unused but could possibly be used
in future to improve pte_protnone().
Signed-off-by: Paul Mackerras <paulus at samba.org>
---
arch/powerpc/include/asm/book3s/64/hash.h | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
index a59cfae..cd4bf95 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -13,9 +13,12 @@
* We could create separate kernel read-only if we used the 3 PP bits
* combinations that newer processors provide but we currently don't.
*/
-#define _PAGE_BIT_SWAP_TYPE 2
-#define _PAGE_USER 0x00004 /* page may be accessed by userspace */
-#define _PAGE_EXEC 0x00008 /* execute permission */
+#define _PAGE_BIT_SWAP_TYPE 0
+
+#define _PAGE_EXEC 0x00001 /* execute permission */
+#define _PAGE_RW 0x00002 /* read & write access allowed */
+#define _PAGE_READ 0x00004 /* read access allowed */
+#define _PAGE_USER 0x00008 /* page may be accessed by userspace */
#define _PAGE_GUARDED 0x00010 /* G: guarded (side-effect) page */
/* M (memory coherence) is always set in the HPTE, so we don't need it here */
#define _PAGE_COHERENT 0x0
@@ -23,7 +26,6 @@
#define _PAGE_WRITETHRU 0x00040 /* W: cache write-through */
#define _PAGE_DIRTY 0x00080 /* C: page changed */
#define _PAGE_ACCESSED 0x00100 /* R: page referenced */
-#define _PAGE_RW 0x00200 /* software: user write access allowed */
#define _PAGE_BUSY 0x00800 /* software: PTE & hash are busy */
#define _PAGE_SPECIAL 0x10000 /* software: special page */
--
2.6.4
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