powerpc/mm: Define flags for Strong Access Ordering

This patch defines:

- PROT_SAO, which is passed into mmap() and mprotect() in the prot field
- VM_SAO in vma->vm_flags, and
- _PAGE_SAO, the combination of WIMG bits in the pte that enables strong
access ordering for the page.

Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/asm-powerpc/pgtable-ppc64.h b/include/asm-powerpc/pgtable-ppc64.h
index b2754d46be44..d09599cccb35 100644
--- a/include/asm-powerpc/pgtable-ppc64.h
+++ b/include/asm-powerpc/pgtable-ppc64.h
@@ -93,6 +93,9 @@
 #define _PAGE_RW        0x0200 /* software: user write access allowed */
 #define _PAGE_BUSY      0x0800 /* software: PTE & hash are busy */
 
+/* Strong Access Ordering */
+#define _PAGE_SAO       (_PAGE_WRITETHRU | _PAGE_NO_CACHE | _PAGE_COHERENT)
+
 #define _PAGE_BASE      (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_COHERENT)
 
 #define _PAGE_WRENABLE  (_PAGE_RW | _PAGE_DIRTY)