linux.git/arch/s390/kernel/setup.c, branch v4.4.12

s390/cpumf: add missing lpp magic initialization

2016-04-12T16:08:36+00:00

commit 8f100bb1ff27873dd71f636da670e503b9ade3c6 upstream.

Add the missing lpp magic initialization for cpu 0. Without this all
samples on cpu 0 do not have the most significant bit set in the
program parameter field, which we use to distinguish between guest and
host samples if the pid is also 0.

We did initialize the lpp magic in the absolute zero lowcore but
forgot that when switching to the allocated lowcore on cpu 0 only.

Reported-by: Shu Juan Zhang 
Acked-by: Christian Borntraeger 
Fixes: e22cf8ca6f75 ("s390/cpumf: rework program parameter setting to detect guest samples")
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky 
Signed-off-by: Greg Kroah-Hartman

s390: remove g5 elf platform support

2015-11-16T11:04:41+00:00

Remove dead code, since this could only happen on a 31 bit machine
where the kernel wouldn't IPL.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/setup: fix novx parameter

2015-08-19T08:40:04+00:00

The novx parameter disables the vector facility but the HWCAP_S390_VXRS
bit in the ELf hardware capabilies is always set if the machine has
the vector facility. If the user space program uses the "vx" string
in the features field of /proc/cpuinfo to utilize vector instruction
it will crash if the novx kernel paramter is set.

Convert setup_hwcaps to an arch_initcall and use MACHINE_HAS_VX to
decide if the HWCAPS_S390_VXRS bit needs to be set.

Cc: stable@vger.kernel.org # 3.18+
Reported-by: Ulrich Weigand 
Reviewed-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/numa: add core infrastructure

2015-08-03T16:40:25+00:00

Enable core NUMA support for s390 and add one simple default mode "plain"
that creates one single NUMA node.

This patch contains several changes from Michael Holzheu.

Signed-off-by: Philipp Hachtmann 
Signed-off-by: Michael Holzheu 
Signed-off-by: Martin Schwidefsky

s390/module: enable generic CPU feature modalias using s390 ELF hwcaps

2015-07-22T07:58:02+00:00

Add support for the generic CPU feature modalias implementation that wires
up optional CPU features to udev-based module autoprobing.

The  file provides definitions to map CPU features to
s390 ELF hardware capabilities.

Signed-off-by: Hendrik Brueckner 
Signed-off-by: Martin Schwidefsky

revert "s390/mm: make hugepages_supported a boot time decision"

2015-07-17T23:39:52+00:00

Heiko noticed that the current check for hugepage support on s390 is a
little bit too harsh as systems which do not support will crash.

The reason is that pageblock_order can now get negative when we set
HPAGE_SHIFT to 0.  To avoid all this and to avoid opening another can of
worms with enabling HUGETLB_PAGE_SIZE_VARIABLE I think it would be best
to simply allow architectures to define their own hugepages_supported().

Revert bea41197ead3 ("s390/mm: make hugepages_supported a boot time
decision") in preparation.

Signed-off-by: Dominik Dingel 
Acked-by: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Christian Borntraeger 
Cc: Michael Holzheu 
Cc: Gerald Schaefer 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2015-07-01T04:44:14+00:00

Pull more s390 updates from Martin Schwidefsky:
 "There is one larger patch for the AP bus code to make it work with the
  longer reset periods of the latest crypto cards.

  A new default configuration, a naming cleanup for SMP and a few fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/kdump: fix compile for !SMP
  s390/kdump: fix nosmt kernel parameter
  s390: new default configuration
  s390/smp: cleanup core vs. cpu in the SCLP interface
  s390/smp: fix sigp cpu detection loop
  s390/zcrypt: Fixed reset and interrupt handling of AP queues
  s390/kdump: fix REGSET_VX_LOW vector register ELF notes
  s390/bpf: Fix backward jumps

s390/mm: make hugepages_supported a boot time decision

2015-06-26T00:00:35+00:00

There is a potential bug with KVM and hugetlbfs if the hardware does not
support hugepages (EDAT1).  We fix this by making EDAT1 a hard requirement
for hugepages and therefore removing and simplifying code.

As s390, with the sw-emulated hugepages, was the only user of
arch_prepare/release_hugepage I also removed theses calls from common and
other architecture code.

This patch (of 5):

By dropping support for hugepages on machines which do not have the
hardware feature EDAT1, we fix a potential s390 KVM bug.

The bug would happen if a guest is backed by hugetlbfs (not supported
currently), but does not get pagetables with PGSTE.  This would lead to
random memory overwrites.

Signed-off-by: Dominik Dingel 
Acked-by: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Christian Borntraeger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

s390/kdump: fix nosmt kernel parameter

2015-06-25T07:39:26+00:00

It turned out that SIGP set-multi-threading can only be done once.
Therefore switching to a different MT level after switching to
sclp.mtid_prev in the dump case fails.

As a symptom specifying the "nosmt" parameter currently fails for
the kdump kernel and the kernel starts with multi-threading enabled.

So fix this and issue diag 308 subcode 1 call after collecting the
CPU states for the dump. Also enhance the diag308_reset() function to
be usable also with enabled lowcore protection and prefix register != 0.
After the reset it is possible to switch the MT level again. We have
to do the reset very early in order not to kill the already initialized
console. Therefore instead of kmalloc() the corresponding memblock
functions have to be used. To avoid copying the sclp cpu code into
sclp_early, we now use the simple sigp loop method for CPU detection.

Signed-off-by: Michael Holzheu 
Signed-off-by: Martin Schwidefsky

s390/setup: fix DMA_API_DEBUG warnings

2015-06-18T13:45:46+00:00

Addresses from the usable space in [_ehead, _stext] lead to false
positives in DMA_API_DEBUG code (which will complain when an address
is in [_text, _etext]).

Avoid these warnings by not using that memory in case of
CONFIG_DMA_API_DEBUG=y.

Signed-off-by: Sebastian Ott 
Signed-off-by: Martin Schwidefsky