AMD NTB support hotplug under B2B mode. NTB will trigger link
up/down interrupt event when doing plug add/remove, this patch
implements the two interrupt event to support B2B hotplug function.
Signed-off-by: NXiangliang Yu <Xiangliang.Yu@amd.com>
Signed-off-by: NShyam Sundar S K <Shyam-sundar.S-k@amd.com>
Acked-by: NAllen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

The Skylake Xeon NTB hardware has made some changes to the register name,
offset, and the way doorbells work. Adding driver support for the new
hardware.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Acked-by: NAllen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Pull MIPS fixes from Ralf Baechle:
 "Two more MIPS fixes for 4.9:

   - RTC: Return -ENODEV so an external RTC will be tried

   - Fix mask of GPE frequency

  These two have been tested on Imagination's automated test system and
  also both received positive reviews on the linux-mips mailing list"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: Lantiq: Fix mask of GPE frequency
  MIPS: Return -ENODEV from weak implementation of rtc_mips_set_time

The hardware documentation says bit 11:10 are used for the GPE
frequency selection. Fix the mask in the define to match these bits.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NThomas Langer <thomas.langer@intel.com>
Cc: linux-mips@linux-mips.org
Cc: john@phrozen.org
Patchwork: https://patchwork.linux-mips.org/patch/14648/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The sync_cmos_clock function in kernel/time/ntp.c first tries to update
the internal clock of the cpu by calling the "update_persistent_clock64"
architecture specific function.  If this returns -ENODEV, it then tries
to update an external RTC using "rtc_set_ntp_time".

On the mips architecture, the weak implementation of the underlying
function would return 0 if it wasn't overridden.  This meant that the
sync_cmos_clock function would never try to update an external RTC
(if both CONFIG_GENERIC_CMOS_UPDATE and CONFIG_RTC_SYSTOHC are
configured)

Returning -ENODEV instead, means that an external RTC will be tried.
Signed-off-by: NLuuk Paulussen <luuk.paulussen@alliedtelesis.co.nz>
Reviewed-by: NRichard Laing <richard.laing@alliedtelesis.co.nz>
Reviewed-by: NScott Parlane <scott.parlane@alliedtelesis.co.nz>
Reviewed-by: NChris Packham <chris.packham@alliedtelesis.co.nz>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14649/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Pull crypto fixes from Herbert Xu:
 "This fixes the following issues:

   - Fix pointer size when caam is used with AArch64 boot loader on
     AArch32 kernel.

   - Fix ahash state corruption in marvell driver.

   - Fix buggy algif_aed tag handling.

   - Prevent mcryptd from being used with incompatible algorithms which
     can cause crashes"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: algif_aead - fix uninitialized variable warning
  crypto: mcryptd - Check mcryptd algorithm compatibility
  crypto: algif_aead - fix AEAD tag memory handling
  crypto: caam - fix pointer size for AArch64 boot loader, AArch32 kernel
  crypto: marvell - Don't corrupt state of an STD req for re-stepped ahash
  crypto: marvell - Don't copy hash operation twice into the SRAM

Pull networking fixes from David Miller:

 1) Limit the number of can filters to avoid > MAX_ORDER allocations.
    Fix from Marc Kleine-Budde.

 2) Limit GSO max size in netvsc driver to avoid problems with NVGRE
    configurations. From Stephen Hemminger.

 3) Return proper error when memory allocation fails in
    ser_gigaset_init(), from Dan Carpenter.

 4) Missing linkage undo in error paths of ipvlan_link_new(), from Gao
    Feng.

 5) Missing necessayr SET_NETDEV_DEV in lantiq and cpmac drivers, from
    Florian Fainelli.

 6) Handle probe deferral properly in smsc911x driver.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  net: mlx5: Fix Kconfig help text
  net: smsc911x: back out silently on probe deferrals
  ibmveth: set correct gso_size and gso_type
  net: ethernet: cpmac: Call SET_NETDEV_DEV()
  net: ethernet: lantiq_etop: Call SET_NETDEV_DEV()
  vhost-vsock: fix orphan connection reset
  cxgb4/cxgb4vf: Assign netdev->dev_port with port ID
  driver: ipvlan: Unlink the upper dev when ipvlan_link_new failed
  ser_gigaset: return -ENOMEM on error instead of success
  NET: usb: cdc_mbim: add quirk for supporting Telit LE922A
  can: peak: fix bad memory access and free sequence
  phy: Don't increment MDIO bus refcount unless it's a different owner
  netvsc: reduce maximum GSO size
  drivers: net: cpsw-phy-sel: Clear RGMII_IDMODE on "rgmii" links
  can: raw: raw_setsockopt: limit number of can_filter that can be set

Since the following commit, Infiniband and Ethernet have not been
mutually exclusive.

Fixes: 4aa17b28 mlx5: Enable mutual support for IB and Ethernet
Signed-off-by: NChristopher Covington <cov@codeaurora.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When trying to get a regulator we may get deferred and we see
this noise:

smsc911x 1b800000.ethernet-ebi2 (unnamed net_device) (uninitialized):
   couldn't get regulators -517

Then the driver continues anyway. Which means that the regulator
may not be properly retrieved and reference counted, and may be
switched off in case noone else is using it.

Fix this by returning silently on deferred probe and let the
system work it out.

Cc: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is based on an earlier one submitted
by Jon Maxwell with the following commit message:

"We recently encountered a bug where a few customers using ibmveth on the
same LPAR hit an issue where a TCP session hung when large receive was
enabled. Closer analysis revealed that the session was stuck because the
one side was advertising a zero window repeatedly.

We narrowed this down to the fact the ibmveth driver did not set gso_size
which is translated by TCP into the MSS later up the stack. The MSS is
used to calculate the TCP window size and as that was abnormally large,
it was calculating a zero window, even although the sockets receive buffer
was completely empty."

We rely on the Virtual I/O Server partition in a pseries
environment to provide the MSS through the TCP header checksum
field. The stipulation is that users should not disable checksum
offloading if rx packet aggregation is enabled through VIOS.

Some firmware offerings provide the MSS in the RX buffer.
This is signalled by a bit in the RX queue descriptor.
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NPradeep Satyanarayana <pradeeps@linux.vnet.ibm.com>
Reviewed-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: NJonathan Maxwell <jmaxwell37@gmail.com>
Reviewed-by: NDavid Dai <zdai@us.ibm.com>
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull libnvdimm fixes from Dan Williams:
 "Several fixes to the DSM (ACPI device specific method) marshaling
  implementation.

  I consider these urgent enough to send for 4.9 consideration since
  they fix the kernel's handling of ARS (Address Range Scrub) commands.
  Especially for platforms without machine-check-recovery capabilities,
  successful execution of ARS commands enables the platform to
  potentially break out of an infinite reboot problem if a media error
  is present in the boot path. There is also a one line fix for a
  device-dax read-only mapping regression.

  Commits 9a901f54 ("acpi, nfit: fix extended status translations
  for ACPI DSMs") and 325896ff ("device-dax: fix private mapping
  restriction, permit read-only") are true regression fixes for changes
  introduced this cycle.

  Commit efda1b5d ("acpi, nfit, libnvdimm: fix / harden ars_status
  output length handling") fixes the kernel's handling of zero-length
  results, this never would have worked in the past, but we only just
  recently discovered a BIOS implementation that emits this arguably
  spec non-compliant result.

  The remaining two commits are additional fall out from thinking
  through the implications of a zero / truncated length result of the
  ARS Status command.

  In order to mitigate the risk that these changes introduce yet more
  regressions they are backstopped by a new unit test in commit
  a7de92da ("tools/testing/nvdimm: unit test acpi_nfit_ctl()") that
  mocks up inputs to acpi_nfit_ctl()"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  device-dax: fix private mapping restriction, permit read-only
  tools/testing/nvdimm: unit test acpi_nfit_ctl()
  acpi, nfit: fix bus vs dimm confusion in xlat_status
  acpi, nfit: validate ars_status output buffer size
  acpi, nfit, libnvdimm: fix / harden ars_status output length handling
  acpi, nfit: fix extended status translations for ACPI DSMs

Pull libata fixes from Tejun Heo:
 "This is quite late but SCT Write Same support added during this cycle
  is broken subtly but seriously and it'd be best to disable it before
  v4.9 gets released.

  This contains two commits - one low impact sata_mv fix and the
  mentioned disabling of SCT Write Same"

* 'for-4.9-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  libata-scsi: disable SCT Write Same for the moment
  ata: sata_mv: check for errors when parsing nr-ports from dt

Pull ceph fix from Ilya Dryomov:
 "A fix for an issue with ->d_revalidate() in ceph, causing frequent
  kernel crashes.

  Marked for stable - it goes back to 4.6, but started popping up only
  in 4.8"

* tag 'ceph-for-4.9-rc9' of git://github.com/ceph/ceph-client:
  ceph: don't set req->r_locked_dir in ceph_d_revalidate

Pull ARM SoC fixes from Olof Johansson:
 "Final batch of SoC fixes

  A few fixes that have trickled in over the last week, all fixing minor
  errors in devicetrees -- UART pin assignment on Allwinner H3,
  correcting number of SATA ports on a Marvell-based Linkstation
  platform and a display clock fix for Freescale/NXP i.MX7D that fixes a
  freeze when starting up X"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: dts: orion5x: fix number of sata port for linkstation ls-gl
  ARM: dts: imx7d: fix LCDIF clock assignment
  dts: sun8i-h3: correct UART3 pin definitions

Pull m68k fixes from Geert Uytterhoeven:

 - build fix for drivers calling ndelay() in a conditional block without
   curly braces

 - defconfig updates

* tag 'm68k-for-v4.9-tag2' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k: Fix ndelay() macro
  m68k/defconfig: Update defconfigs for v4.9-rc1

Pull drm fix from Dave Airlie:
 "Just a single fix for amdgpu to just suspend the gpu on 'shutdown'
  instead of shutting it down fully, as for some reason the hw was
  getting upset in some situations"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/amdgpu: just suspend the hw on pci shutdown

This reverts commit 53855d10.

It shouldn't have come in yet - it depends on the changes in linux-next
that will come in during the next merge window.  As Matthew Wilcox says,
the test suite is broken with the current state without the revert.
Requested-by: NMatthew Wilcox <mawilcox@microsoft.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Florian Fainelli says:

====================
net: ethernet: Make sure we set dev->dev.parent

This patch series builds atop:

ec988ad7 ("phy: Don't increment MDIO
bus refcount unless it's a different owner")

FMAN is the one that potentially needs patching as well (call
SET_NETDEV_DEV), but there appears to be no way that init_phy is
called right now, or there is not such an in-tree user. Madalin, can
you comment on that?
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The TI CPMAC driver calls into PHYLIB which now checks for
net_device->dev.parent, so make sure we do set it before calling into
any MDIO/PHYLIB related function.

Fixes: ec988ad7 ("phy: Don't increment MDIO bus refcount unless it's a different owner")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The Lantiq Etop driver calls into PHYLIB which now checks for
net_device->dev.parent, so make sure we do set it before calling into
any MDIO/PHYLIB related function.

Fixes: ec988ad7 ("phy: Don't increment MDIO bus refcount unless it's a different owner")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

local_addr.svm_cid is host cid. We should check guest cid instead,
which is remote_addr.svm_cid. Otherwise we end up resetting all
connections to all guests.

Cc: stable@vger.kernel.org [4.8+]
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPeng Tao <bergwolf@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull parisc fixes from Helge Deller:
 "Three important fixes for the parisc architecture.

  Dave provided two patches: One which purges the TLB before setting a
  PTE entry and a second one which drops unnecessary TLB flushes. Both
  patches have been tested for one week on the debian buildd servers and
  prevent random segmentation faults.

  The patch from me fixes a crash at boot inside the TLB measuring code
  on SMP machines with PA8000-PA8700 CPUs (specifically A500-44 and
  J5000 servers)"

* 'parisc-4.9-5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix TLB related boot crash on SMP machines
  parisc: Remove unnecessary TLB purges from flush_dcache_page_asm and flush_icache_page_asm
  parisc: Purge TLB before setting PTE

Merge tag 'linux-can-fixes-for-4.9-20161208' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2016-12-08

this is a pull request for one patch.

Jiho Chu found and fixed a use-after-free error in the cleanup path in
the peak pcan USB CAN driver.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Added missing dev_port assignment in cxgb4vf driver.
Also made dev_port assignment of cxgb4 in sync with cxgb4vf driver.
Signed-off-by: NCasey Leedom <leedom@chelsio.com>
Signed-off-by: NArjun V <arjun@chelsio.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NGanesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

At bootup we run measurements to calculate the best threshold for when we
should be using full TLB flushes instead of just flushing a specific amount of
TLB entries.  This performance test is run over the kernel text segment.

But running this TLB performance test on the kernel text segment turned out to
crash some SMP machines when the kernel text pages were mapped as huge pages.

To avoid those crashes this patch simply skips this test on some SMP machines
and calculates an optimal threshold based on the maximum number of available
TLB entries and number of online CPUs.

On a technical side, this seems to happen:
The TLB measurement code uses flush_tlb_kernel_range() to flush specific TLB
entries with a page size of 4k (pdtlb 0(sr1,addr)). On UP systems this purge
instruction seems to work without problems even if the pages were mapped as
huge pages.  But on SMP systems the TLB purge instruction is broadcasted to
other CPUs. Those CPUs then crash the machine because the page size is not as
expected.  C8000 machines with PA8800/PA8900 CPUs were not affected by this
problem, because the required cache coherency prohibits to use huge pages at
all.  Sadly I didn't found any documentation about this behaviour, so this
finding is purely based on testing with phyiscal SMP machines (A500-44 and
J5000, both were 2-way boxes).

Cc: <stable@vger.kernel.org> # v3.18+
Signed-off-by: NHelge Deller <deller@gmx.de>

Pull SCSI fix from James Bottomley:
 "One small fix for a regression in a prior fix (again).

  This time the condition in the prior fix BUG_ON proved to be wrong
  under certain circumstances causing a BUG to trigger where it
  shouldn't in the lpfc driver"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: lpfc: fix oops/BUG in lpfc_sli_ringtxcmpl_put()

When netdev_upper_dev_unlink failed in ipvlan_link_new, need to
unlink the ipvlan dev with upper dev.
Signed-off-by: NGao Feng <fgao@ikuai8.com>
Acked-by: NMahesh Bandewar <maheshb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If we can't allocate the resources in gigaset_initdriver() then we
should return -ENOMEM instead of zero.

Fixes: 2869b23e ("[PATCH] drivers/isdn/gigaset: new M101 driver (v2)")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Bug report from Debian [0] shows there's minor changed model of
Linkstation LS-GL that uses the 2nd SATA port of the SoC.
So it's necessary to enable two SATA ports, though for that specific
model only the 2nd one is used.

[0] https://bugs.debian.org/845611

Fixes: b1742ffa ("ARM: dts: orion5x: add device tree for buffalo linkstation ls-gl")
Reported-by: NRyan Tandy <ryan@nardis.ca>
Tested-by: NRyan Tandy <ryan@nardis.ca>
Signed-off-by: NRoger Shimizu <rogershimizu@gmail.com>
Signed-off-by: NGregory CLEMENT <gregory.clement@free-electrons.com>

Telit LE922A MBIM based composition does not work properly
with altsetting toggle done in cdc_ncm_bind_common.

This patch adds CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE quirk
to avoid this procedure that, instead, is mandatory for
other modems.
Signed-off-by: NDaniele Palmas <dnlplm@gmail.com>
Reviewed-by: NBjørn Mork <bjorn@mork.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix for bad memory access while disconnecting. netdev is freed before
private data free, and dev is accessed after freeing netdev.

This makes a slub problem, and it raise kernel oops with slub debugger
config.
Signed-off-by: NJiho Chu <jiho.chu@samsung.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This function sets req->r_locked_dir which is supposed to indicate to
ceph_fill_trace that the parent's i_rwsem is locked for write.
Unfortunately, there is no guarantee that the dir will be locked when
d_revalidate is called, so we really don't want ceph_fill_trace to do
any dcache manipulation from this context. Clear req->r_locked_dir since
it's clearly not safe to do that.

What we really want to know with d_revalidate is whether the dentry
still points to the same inode. ceph_fill_trace installs a pointer to
the inode in req->r_target_inode, so we can just compare that to
d_inode(dentry) to see if it's the same one after the lookup.

Also, since we aren't generally interested in the parent here, we can
switch to using a GETATTR to hint that to the MDS, which also means that
we only need to reserve one cap.

Finally, just remove the d_unhashed check. That's really outside the
purview of a filesystem's d_revalidate. If the thing became unhashed
while we're checking it, then that's up to the VFS to handle anyway.

Fixes: 200fd27c ("ceph: use lookup request to revalidate dentry")
Link: http://tracker.ceph.com/issues/18041Reported-by: NDonatas Abraitis <donatas.abraitis@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: N"Yan, Zheng" <zyan@redhat.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

In case the user provided insufficient data, the code may return
prematurely without any operation. In this case, the processed
data indicated with outlen is zero.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NStephan Mueller <smueller@chronox.de>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Merge more fixes from Andrew Morton:
 "3 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kcov: add missing #include <linux/sched.h>
  radix tree test suite: fix compilation
  zram: restrict add/remove attributes to root only

In __sanitizer_cov_trace_pc we use task_struct and fields within it, but
as we haven't included <linux/sched.h>, it is not guaranteed to be
defined.  While we usually happen to acquire the definition through a
transitive include, this is fragile (and hasn't been true in the past,
causing issues with backports).

Include <linux/sched.h> to avoid any fragility.

[mark.rutland@arm.com: rewrote changelog]
Link: http://lkml.kernel.org/r/1481007384-27529-1-git-send-email-wangkefeng.wang@huawei.comSigned-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch "lib/radix-tree: Convert to hotplug state machine" breaks the test
suite as it adds a call to cpuhp_setup_state_nocalls() which is not
currently emulated in the test suite.  Add it, and delete the emulation
of the old CPU hotplug mechanism.

Link: http://lkml.kernel.org/r/1480369871-5271-36-git-send-email-mawilcox@linuxonhyperv.comSigned-off-by: NMatthew Wilcox <mawilcox@microsoft.com>
Tested-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

zram hot_add sysfs attribute is a very 'special' attribute - reading
from it creates a new uninitialized zram device.  This file, by a
mistake, can be read by a 'normal' user at the moment, while only root
must be able to create a new zram device, therefore hot_add attribute
must have S_IRUSR mode, not S_IRUGO.

[akpm@linux-foundation.org: s/sence/sense/, reflow comment to use 80 cols]
Fixes: 6566d1a3 ("zram: add dynamic device add/remove functionality")
Link: http://lkml.kernel.org/r/20161205155845.20129-1-sergey.senozhatsky@gmail.comSigned-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: NSteven Allen <steven@stebalien.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>    [4.2+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

another regression fix for the shutdown stuff.

* 'drm-fixes-4.9' of git://people.freedesktop.org/~agd5f/linux:
  drm/amdgpu: just suspend the hw on pci shutdown

SCT Write Same support had been introduced with
commit 7b203094 ("libata: Add support for SCT Write Same")

Some problems, namely excessive userspace segfaults, had been reported at

  http://lkml.kernel.org/r/20160908192736.GA4356@gmail.com

This lead to commit 0ce1b18c ("libata: Some drives failing on
SCT Write Same") which strived to disable SCT Write Same on !ZAC devices.
Due to the way this was done and to the logic in sd_config_write_same(),
this didn't work for those devices that have
->max_ws_blocks > SD_MAX_WS10_BLOCKS: for these, ->no_write_same and
->max_write_same_sectors would still be non-zero,
but ->ws10 == ->ws16 == 0. This would cause sd_setup_write_same_cmnd() to
demultiplex REQ_OP_WRITE_SAME requests to WRITE_SAME, and these in turn
aren't supported by libata-scsi:

  EXT4-fs (dm-1): Delayed block allocation failed for inode 2625094 at
                  logical offset 2032 with max blocks 2 with error 121
  EXT4-fs (dm-1): This should not happen!! Data will be lost

121 == EREMOTEIO is what scsi_io_completion() asserts in case of
invalid opcodes.

Back to the original problem of userspace segfaults: this can be tracked
down to ata_format_sct_write_same() overwriting the input page. Sometimes,
this page is ZERO_PAGE(0) which ceases to be filled with zeros from that
point on. Since ZERO_PAGE(0) is used for userspace .bss mappings, code of
the following is doomed:

  static char *a = NULL; /* .bss */
  ...
  if (a)
    *a = 'a';

This problem is not solved by disabling SCT Write Same for !ZAC devices
only.

It can certainly be fixed, but the final release is quite close -- so
disable SCT Write Same for all ATA devices rather than introducing some
SCT key buffer allocation schemes at this point.

Fixes: 7b203094 ("libata: Add support for SCT Write Same")
Signed-off-by: NNicolai Stange <nicstange@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>