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-40x.h b/arch/powerpc/include/asm/pte-40x.h
index 07630faae029..6c3e1f4378d4 100644
--- a/arch/powerpc/include/asm/pte-40x.h
+++ b/arch/powerpc/include/asm/pte-40x.h
@@ -46,7 +46,7 @@
 #define _PAGE_RW        0x040   /* software: Writes permitted */
 #define _PAGE_DIRTY     0x080   /* software: dirty page */
 #define _PAGE_HWWRITE   0x100   /* hardware: Dirty & RW, set in exception */
-#define _PAGE_HWEXEC    0x200   /* hardware: EX permission */
+#define _PAGE_EXEC      0x200   /* hardware: EX permission */
 #define _PAGE_ACCESSED  0x400   /* software: R: page referenced */
 
 #define _PMD_PRESENT    0x400   /* PMD points to page of PTEs */