Re: powerpc/mm: Add _PAGE_SAO to _PAGE_CACHE_CTL mask

On Mon, 2019-01-28 at 17:31:42 UTC, Reza Arbab wrote:

In htab_convert_pte_flags(), _PAGE_CACHE_CTL is used to check for the
_PAGE_SAO flag:

  else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_SAO)
          rflags |= (HPTE_R_W | HPTE_R_I | HPTE_R_M);

But, it isn't defined to include that flag:

  #define _PAGE_CACHE_CTL (_PAGE_NON_IDEMPOTENT | _PAGE_TOLERANT)

This happens to work, but only because of the flag values:

  #define _PAGE_SAO               0x00010 /* Strong access order */
  #define _PAGE_NON_IDEMPOTENT    0x00020 /* non idempotent memory */
  #define _PAGE_TOLERANT          0x00030 /* tolerant memory, cache inhibited */

To prevent any issues if these particulars ever change, add _PAGE_SAO to
the mask.

Suggested-by: Charles Johns <redacted>
Signed-off-by: Reza Arbab <redacted>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/865a9432d16fe2f40a1a52005fd30778

cheers