Comment 4 for bug 1555344

------- Comment From <email address hidden> 2016-03-16 03:54 EDT-------
(In reply to comment #6)
> @TIM this has nothing to do with PPC. this is s390x request. STFLE sounds
> like a little-endian symbol name.... whereas s390x is big-endian, no?

This is entirely s390x. The STFLE is an instruction: "STore Facility List Extented".

------- Comment From <email address hidden> 2016-03-16 04:07 EDT-------
(In reply to comment #5)
> How about a backport to v4.4 ? Attempting to cherry-pick caused a conflict
> because the existing macro in the assembler instruction is
> __LC_STFL_FAC_LIST whereas the expected macro is __LC_STFLE_FAC_LIST. My PPC
> assembler foo is weak.

To cleanly apply the required patch, please also apply the below one first:

commit 76cdd44c2e56ffabc297494c090c6babc8985998
Author: Heiko Carstens <email address hidden>
Date: Tue Nov 24 12:33:07 2015 +0100

s390/facilities: always use lowcore's stfle field for storing facility bits
head.s contains an stfle instruction which stores it result at the
storage location that is assigned to the stfl instruction.
This is currently no problem, since we only care about one double
word. However if the number of double words in the ALS bitfield grows
the current code is not very stable.

E.g. before issuing the stfle command the memory to which it stores
must be cleared, since the instruction may or may not clear memory
contents where no bits are set.

In order to simplify the code a bit always use the storage location
that we reserved for the stfle result.

Signed-off-by: Heiko Carstens <email address hidden>
Signed-off-by: Martin Schwidefsky <email address hidden>