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. NOTE: There doesn't seem to be a precedent for architecture-dependent vm_flags. It may be better to define VM_SAO somewhere in include/asm-powerpc/. Since vm_flags is a long, defining it in the high-order word would help prevent a collision with any newly added values in architecture-independent code. Signed-off-by: Dave Kleikamp --- include/asm-powerpc/mman.h | 2 ++ include/asm-powerpc/pgtable-ppc64.h | 3 +++ include/linux/mm.h | 1 + 3 files changed, 6 insertions(+) Index: b/include/asm-powerpc/mman.h =================================================================== --- a/include/asm-powerpc/mman.h +++ b/include/asm-powerpc/mman.h @@ -10,6 +10,8 @@ * 2 of the License, or (at your option) any later version. */ +#define PROT_SAO 0x10 /* Strong Access Ordering */ + #define MAP_RENAME MAP_ANONYMOUS /* In SunOS terminology */ #define MAP_NORESERVE 0x40 /* don't reserve swap pages */ #define MAP_LOCKED 0x80 Index: b/include/asm-powerpc/pgtable-ppc64.h =================================================================== --- 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) Index: b/include/linux/mm.h =================================================================== --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -108,6 +108,7 @@ #define VM_CAN_NONLINEAR 0x08000000 /* Has ->fault & does nonlinear pages */ #define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */ +#define VM_SAO 0x20000000 /* Strong Access Ordering (powerpc) */ #ifndef VM_STACK_DEFAULT_FLAGS /* arch can override this */ #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS -- Dave Kleikamp IBM Linux Technology Center