Merge tag 's390-6.4-2' of git://

Pull s390 fixes from Alexander Gordeev:

 - Add check whether the required facilities are installed before using
   the s390-specific ChaCha20 implementation

 - Key blobs for s390 protected key interface IOCTLs commands
   PKEY_VERIFYKEY2 and PKEY_VERIFYKEY3 may contain clear key material.
   Zeroize copies of these keys in kernel memory after creating
   protected keys

 - Set CONFIG_INIT_STACK_NONE=y in defconfigs to avoid extra overhead of
   initializing all stack variables by default

 - Make sure that when a new channel-path is enabled all subchannels are
   evaluated: with and without any devices connected on it

 - When SMT thread CPUs are added to CPU topology masks the nr_cpu_ids
   limit is not checked and could be exceeded. Respect the nr_cpu_ids
   limit and avoid a warning when CONFIG_DEBUG_PER_CPU_MAPS is set

 - The pointer to IPL Parameter Information Block is stored in the
   absolute lowcore as a virtual address. Save it as the physical
   address for later use by dump tools

 - Fix a Queued Direct I/O (QDIO) problem on z/VM guests using QIOASSIST
   with dedicated (pass through) QDIO-based devices such as FCP, real
   OSA or HiperSockets

 - s390's struct statfs and struct statfs64 contain padding, which
   field-by-field copying does not set. Initialize the respective
   structures with zeros before filling them and copying to userspace

 - Grow s390 compat_statfs64, statfs and statfs64 structures f_spare
   array member to cover padding and simplify things

 - Remove obsolete SCHED_BOOK and SCHED_DRAWER configs

 - Remove unneeded S390_CCW_IOMMU and S390_AP_IOM configs

* tag 's390-6.4-2' of git://
  s390/iommu: get rid of S390_CCW_IOMMU and S390_AP_IOMMU
  s390/Kconfig: remove obsolete configs SCHED_{BOOK,DRAWER}
  s390/uapi: cover statfs padding by growing f_spare
  statfs: enforce statfs[64] structure initialization
  s390/qdio: fix do_sqbs() inline assembly constraint
  s390/ipl: fix IPIB virtual vs physical address confusion
  s390/topology: honour nr_cpu_ids when adding CPUs
  s390/cio: include subchannels without devices also for evaluation
  s390/defconfigs: set CONFIG_INIT_STACK_NONE=y
  s390/pkey: zeroize key blobs
  s390/crypto: use vector instructions only if available for ChaCha20