• Benjamin Herrenschmidt's avatar
    powerpc/mm: Cleanup handling of execute permission · ea3cc330
    Benjamin Herrenschmidt authored
    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: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
    ea3cc330
pte-44x.h 3.83 KB