powerpc/mm: Cleanup handling of execute permission

This is an attempt at cleaning up a bit the way we handle execute
permission on powerpc. _PAGE_HWEXEC is gone, _PAGE_EXEC is now only
defined by CPUs that can do something with it, and the myriad of
#ifdef's in the I$/D$ coherency code is reduced to 2 cases that
hopefully should cover everything.

The logic on BookE is a little bit different than what it was though
not by much. Since now, _PAGE_EXEC will be set by the generic code
for executable pages, we need to filter out if they are unclean and
recover it. However, I don't expect the code to be more bloated than
it already was in that area due to that change.

I could boast that this brings proper enforcing of per-page execute
permissions to all BookE and 40x but in fact, we've had that now for
some time as a side effect of my previous rework in that area (and
I didn't even know it :-) We would only enable execute permission if
the page was cache clean and we would only cache clean it if we took
and exec fault. Since we now enforce that the later only work if
VM_EXEC is part of the VMA flags, we de-fact already enforce per-page
execute permissions... Unless I missed something

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/pte-44x.h b/arch/powerpc/include/asm/pte-44x.h
index 37e98bcf83e0..4192b9bad901 100644
--- a/arch/powerpc/include/asm/pte-44x.h
+++ b/arch/powerpc/include/asm/pte-44x.h
@@ -78,7 +78,7 @@
 #define _PAGE_PRESENT   0x00000001              /* S: PTE valid */
 #define _PAGE_RW        0x00000002              /* S: Write permission */
 #define _PAGE_FILE      0x00000004              /* S: nonlinear file mapping */
-#define _PAGE_HWEXEC    0x00000004              /* H: Execute permission */
+#define _PAGE_EXEC      0x00000004              /* H: Execute permission */
 #define _PAGE_ACCESSED  0x00000008              /* S: Page referenced */
 #define _PAGE_DIRTY     0x00000010              /* S: Page dirty */
 #define _PAGE_SPECIAL   0x00000020              /* S: Special page */