If devm_reset_control_get_exclusive() fails, asm9260_wdt_probe()
returns immediately. But clks has been already enabled at that point,
so it is required to disable them or to move the code around.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Licence text is specifying "GPLv2" but the MODULE_LICENSE is set to "GPLv2
or later".

See include/linux/module.h:
"GPL"				[GNU Public License v2 or later]
"GPL v2"			[GNU Public License v2]

When on it, add SPDX identifier tag.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog_init_timeout() will preserve wdd->timeout value if
no parameter nor timeout-secs dt property is set.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog_init_timeout() will preserve wdd->timeout value if
no parameter nor timeout-secs dt property is set.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog_init_timeout() will preserve wdd->timeout value if no parameter
nor timeout-secs dt property is set.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog_init_timeout() will allways pick timeout_param since it
defaults to a valid timeout.

Following best practice described in
Documentation/watchdog/watchdog-kernel-api.txt to make use of
the parameter logic.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog_init_timeout() will allways pick timeout_param since it
defaults to a valid timeout.

By following best practice described in
Documentation/watchdog/watchdog-kernel-api.txt, it also
let us to set timout-sec property in devicetree.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog_init_timeout() will allways pick timeout_param since it
defaults to a valid timeout.

By following best practice described in
Documentation/watchdog/watchdog-kernel-api.txt, it also
let us to set timout-sec property in devicetree.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog_init_timeout() will allways pick timeout_param since it
defaults to a valid timeout.

Following best practice described in
Documentation/watchdog/watchdog-kernel-api.txt to make use of
the parameter logic.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog_init_timeout() will allways pick timeout_param since it
defaults to a valid timeout.

By following best practice described in
Documentation/watchdog/watchdog-kernel-api.txt, it also
let us to set timout-sec property in devicetree.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog_init_timeout() will allways pick timeout_param since it
defaults to a valid timeout.

By following best practice described in
Documentation/watchdog/watchdog-kernel-api.txt, it also
let us to set timout-sec property in devicetree.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog_init_timeout() will allways pick timeout_param since it
defaults to a valid timeout.

Following best practice described in
Documentation/watchdog/watchdog-kernel-api.txt to make use of
the parameter logic.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

By following best practice described in
Documentation/watchdog/watchdog-kernel-api.txt, it also let us to set
timout-sec property in devicetree.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Gen8 and prior Proliant systems supported the "CRU" interface
to firmware.  This interfaces allows linux to "call back" into firmware
to source the cause of an NMI.  This feature isn't fully utilized
as the actual source of the NMI isn't printed, the driver only
indicates that the source couldn't be determined when the call
fails.

With the advent of Gen9, iCRU replaces the CRU. The call back
feature is no longer available in firmware.  To be compatible and
not attempt to call back into firmware on system not supporting CRU,
the SMBIOS table is consulted to determine if it is safe to
make the call back or not.

This results in about half of the driver code being devoted
to either making CRU calls or determing if it is safe to make
CRU calls.  As noted, the driver isn't really using the results of
the CRU calls.

Furthermore, as a consequence of the Spectre security issue, the
BIOS/EFI calls are being wrapped into Spectre-disabling section.
Removing the call back in hpwdt_pretimeout assists in this effort.

As the CRU sourcing of the NMI isn't required for handling the
NMI and there are security concerns with making the call back, remove
the legacy (pre Gen9) NMI sourcing and the DMI code to determine if
the system had the CRU interface.
Signed-off-by: Jerry Hoemann <jerry.hoemann@hpe.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

According to SBSA spec v3.1 section 5.3:
  All registers are 32 bits in size and should be accessed using
  32-bit reads and writes. If an access size other than 32 bits
  is used then the results are IMPLEMENTATION DEFINED.
  [...]
  The Generic Watchdog is little-endian

The current code uses readq to read the watchdog compare register
which does a 64-bit access. This fails on ThunderX2 which does not
implement 64-bit access to this register.

Fix this by using lo_hi_readq() that does two 32-bit reads.
Signed-off-by: Jayachandran C <jnair@caviumnetworks.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Watchdog close is "expected" when any byte is 'V' not just the last one.
Writing "V" to the device fails because the last byte is the end of string.

$ echo V > /dev/watchdog
f71808e_wdt: Unexpected close, not stopping watchdog!
Signed-off-by: Igor Pylypiv <igor.pylypiv@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

isp5100_tco.c  uses watchdog core functions (from watchdog_core.c) and, when
compiled without CONFIG_WATCHDOG_CORE being set, it produces the
following build error:

ERROR: "devm_watchdog_register_device" [drivers/watchdog/sp5100_tco.ko] undefined!
ERROR: "watchdog_init_timeout" [drivers/watchdog/sp5100_tco.ko] undefined!

Fix this by selecting CONFIG_WATCHDOG_CORE.

Fixes: 7cd9d5ff ("watchdog: sp5100_tco: Convert to use watchdog subsystem")
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

xen_wdt uses watchdog core functions (from watchdog_core.c) and, when
compiled without CONFIG_WATCHDOG_CORE being set, it produces the
following build error:

ERROR: "devm_watchdog_register_device" [drivers/watchdog/xen_wdt.ko] undefined!
ERROR: "watchdog_init_timeout" [drivers/watchdog/xen_wdt.ko] undefined!

Fix this by selecting CONFIG_WATCHDOG_CORE when CONFIG_XEN_WDT is set.

Fixes: 18cffd68 ("watchdog: xen_wdt: use the watchdog subsystem")
Signed-off-by: Radu Rendec <radu.rendec@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

i6300esb uses fuctions defined in watchdog_core.c, and when
CONFIG_WATCHDOG_CORE is not set we have this build error:

drivers/watchdog/i6300esb.o: In function `esb_remove':
i6300esb.c:(.text+0xcc): undefined reference to `watchdog_unregister_device'
drivers/watchdog/i6300esb.o: In function `esb_probe':
i6300esb.c:(.text+0x2a1): undefined reference to `watchdog_init_timeout'
i6300esb.c:(.text+0x388): undefined reference to `watchdog_register_device'
make: *** [Makefile:1029: vmlinux] Error 1

Fix this by selecting CONFIG_WATCHDOG_CORE when I6300ESB_WDT is set.

Fixes: 7af4ac87 ("watchdog: i6300esb: use the watchdog subsystem")
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

We can build this driver with or without NVMEM, but not built-in
when NVMEM is a loadable module:

drivers/watchdog/rave-sp-wdt.o: In function `rave_sp_wdt_probe':
rave-sp-wdt.c:(.text+0x27c): undefined reference to `nvmem_cell_get'
rave-sp-wdt.c:(.text+0x290): undefined reference to `nvmem_cell_read'
rave-sp-wdt.c:(.text+0x2c4): undefined reference to `nvmem_cell_put'

This adds a Kconfig dependency to enforce that.

Fixes: c3bb3334 ("watchdog: Add RAVE SP watchdog driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Pull x86 Kconfig fixes from Thomas Gleixner:
 "Three patchlets to correct HIGHMEM64G and CMPXCHG64 dependencies in
  Kconfig when CPU selections are explicitely set to M586 or M686"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/Kconfig: Explicitly enumerate i686-class CPUs in Kconfig
  x86/Kconfig: Exclude i586-class CPUs lacking PAE support from the HIGHMEM64G Kconfig group
  x86/Kconfig: Add missing i586-class CPUs to the X86_CMPXCHG64 Kconfig group

Pull perf updates from Thomas Gleixner:
 "Perf tool updates and kprobe fixes:

   - perf_mmap overwrite mode fixes/overhaul, prep work to get 'perf
     top' using it, making it bearable to use it in large core count
     systems such as Knights Landing/Mill Intel systems (Kan Liang)

   - s/390 now uses syscall.tbl, just like x86-64 to generate the
     syscall table id -> string tables used by 'perf trace' (Hendrik
     Brueckner)

   - Use strtoull() instead of home grown function (Andy Shevchenko)

   - Synchronize kernel ABI headers, v4.16-rc1 (Ingo Molnar)

   - Document missing 'perf data --force' option (Sangwon Hong)

   - Add perf vendor JSON metrics for ARM Cortex-A53 Processor (William
     Cohen)

   - Improve error handling and error propagation of ftrace based
     kprobes so failures when installing kprobes are not silently
     ignored and create disfunctional tracepoints"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
  kprobes: Propagate error from disarm_kprobe_ftrace()
  kprobes: Propagate error from arm_kprobe_ftrace()
  Revert "tools include s390: Grab a copy of arch/s390/include/uapi/asm/unistd.h"
  perf s390: Rework system call table creation by using syscall.tbl
  perf s390: Grab a copy of arch/s390/kernel/syscall/syscall.tbl
  tools/headers: Synchronize kernel ABI headers, v4.16-rc1
  perf test: Fix test trace+probe_libc_inet_pton.sh for s390x
  perf data: Document missing --force option
  perf tools: Substitute yet another strtoull()
  perf top: Check the latency of perf_top__mmap_read()
  perf top: Switch default mode to overwrite mode
  perf top: Remove lost events checking
  perf hists browser: Add parameter to disable lost event warning
  perf top: Add overwrite fall back
  perf evsel: Expose the perf_missing_features struct
  perf top: Check per-event overwrite term
  perf mmap: Discard legacy interface for mmap read
  perf test: Update mmap read functions for backward-ring-buffer test
  perf mmap: Introduce perf_mmap__read_event()
  perf mmap: Introduce perf_mmap__read_done()
  ...

Pull irq updates from Thomas Gleixner:
 "A small set of updates mostly for irq chip drivers:

   - MIPS GIC fix for spurious, masked interrupts

   - fix for a subtle IPI bug in GICv3

   - do not probe GICv3 ITSs that are marked as disabled

   - multi-MSI support for GICv2m

   - various small cleanups"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqdomain: Re-use DEFINE_SHOW_ATTRIBUTE() macro
  irqchip/bcm: Remove hashed address printing
  irqchip/gic-v2m: Add PCI Multi-MSI support
  irqchip/gic-v3: Ignore disabled ITS nodes
  irqchip/gic-v3: Use wmb() instead of smb_wmb() in gic_raise_softirq()
  irqchip/gic-v3: Change pr_debug message to pr_devel
  irqchip/mips-gic: Avoid spuriously handling masked interrupts

Pull core fix from Thomas Gleixner:
 "A small fix which adds the missing for_each_cpu_wrap() stub for the UP
  case to avoid build failures"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpumask: Make for_each_cpu_wrap() available on UP as well

Pull block fixes from Jens Axboe:

 - NVMe pull request from Keith, with fixes all over the map for nvme.
   From various folks.

 - Classic polling fix, that avoids a latency issue where we still end
   up waiting for an interrupt in some cases. From Nitesh Shetty.

 - Comment typo fix from Minwoo Im.

* tag 'for-linus-20180217' of git://git.kernel.dk/linux-block:
  block: fix a typo in comment of BLK_MQ_POLL_STATS_BKTS
  nvme-rdma: fix sysfs invoked reset_ctrl error flow
  nvmet: Change return code of discard command if not supported
  nvme-pci: Fix timeouts in connecting state
  nvme-pci: Remap CMB SQ entries on every controller reset
  nvme: fix the deadlock in nvme_update_formats
  blk: optimization for classic polling
  nvme: Don't use a stack buffer for keep-alive command
  nvme_fc: cleanup io completion
  nvme_fc: correct abort race condition on resets
  nvme: Fix discard buffer overrun
  nvme: delete NVME_CTRL_LIVE --> NVME_CTRL_CONNECTING transition
  nvme-rdma: use NVME_CTRL_CONNECTING state to mark init process
  nvme: rename NVME_CTRL_RECONNECTING state to NVME_CTRL_CONNECTING

Pull MMC fixes from Ulf Hansson:

 - meson-gx: Revert to earlier tuning process

 - bcm2835: Don't overwrite max frequency unconditionally

* tag 'mmc-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: bcm2835: Don't overwrite max frequency unconditionally
  Revert "mmc: meson-gx: include tx phase in the tuning process"

Pull mtd fixes from Boris Brezillon:

 - add missing dependency to NAND_MARVELL Kconfig entry

 - use the appropriate OOB layout in the VF610 driver

* tag 'mtd/fixes-for-4.16-rc2' of git://git.infradead.org/linux-mtd:
  mtd: nand: MTD_NAND_MARVELL should depend on HAS_DMA
  mtd: nand: vf610: set correct ooblayout

Pull powerpc fixes from Michael Ellerman:
 "The main attraction is a fix for a bug in the new drmem code, which
  was causing an oops on boot on some versions of Qemu.

  There's also a fix for XIVE (Power9 interrupt controller) on KVM, as
  well as a few other minor fixes.

  Thanks to: Corentin Labbe, Cyril Bur, Cédric Le Goater, Daniel Black,
  Nathan Fontenot, Nicholas Piggin"

* tag 'powerpc-4.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/pseries: Check for zero filled ibm,dynamic-memory property
  powerpc/pseries: Add empty update_numa_cpu_lookup_table() for NUMA=n
  powerpc/powernv: IMC fix out of bounds memory access at shutdown
  powerpc/xive: Use hw CPU ids when configuring the CPU queues
  powerpc: Expose TSCR via sysfs only on powernv

Pull arm64 fixes from Catalin Marinas:
 "The bulk of this is the pte accessors annotation to READ/WRITE_ONCE
  (we tried to avoid pushing this during the merge window to avoid
  conflicts)

   - Updated the page table accessors to use READ/WRITE_ONCE and prevent
     compiler transformation that could lead to an apparent loss of
     coherency

   - Enabled branch predictor hardening for the Falkor CPU

   - Fix interaction between kpti enabling and KASan causing the
     recursive page table walking to take a significant time

   - Fix some sparse warnings"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: cputype: Silence Sparse warnings
  arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables
  arm64: proc: Set PTE_NG for table entries to avoid traversing them twice
  arm64: Add missing Falkor part number for branch predictor hardening

Pull xen fixes from Juergen Gross:

 - fixes for the Xen pvcalls frontend driver

 - fix for booting Xen pv domains

 - fix for the xenbus driver user interface

* tag 'for-linus-4.16a-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  pvcalls-front: wait for other operations to return when release passive sockets
  pvcalls-front: introduce a per sock_mapping refcount
  x86/xen: Calculate __max_logical_packages on PV domains
  xenbus: track caller request id

Passive sockets can have ongoing operations on them, specifically, we
have two wait_event_interruptable calls in pvcalls_front_accept.

Add two wake_up calls in pvcalls_front_release, then wait for the
potential waiters to return and release the sock_mapping refcount.
Signed-off-by: Stefano Stabellini <stefano@aporeto.com>
Acked-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

Introduce a per sock_mapping refcount, in addition to the existing
global refcount. Thanks to the sock_mapping refcount, we can safely wait
for it to be 1 in pvcalls_front_release before freeing an active socket,
instead of waiting for the global refcount to be 1.
Signed-off-by: Stefano Stabellini <stefano@aporeto.com>
Acked-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

The kernel panics on PV domains because native_smp_cpus_done() is
only called for HVM domains.

Calculate __max_logical_packages for PV domains.

Fixes: b4c0a732 ("x86/smpboot: Fix __max_logical_packages estimate")
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Tested-and-reported-by: Simon Gaiser <simon@invisiblethingslab.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: xen-devel@lists.xenproject.org
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

Commit fd8aa909 ("xen: optimize xenbus driver for multiple concurrent
xenstore accesses") optimized xenbus concurrent accesses but in doing so
broke UABI of /dev/xen/xenbus. Through /dev/xen/xenbus applications are in
charge of xenbus message exchange with the correct header and body. Now,
after the mentioned commit the replies received by application will no
longer have the header req_id echoed back as it was on request (see
specification below for reference), because that particular field is being
overwritten by kernel.

struct xsd_sockmsg
{
  uint32_t type;  /* XS_??? */
  uint32_t req_id;/* Request identifier, echoed in daemon's response.  */
  uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */
  uint32_t len;   /* Length of data following this. */

  /* Generally followed by nul-terminated string(s). */
};

Before there was only one request at a time so req_id could simply be
forwarded back and forth. To allow simultaneous requests we need a
different req_id for each message thus kernel keeps a monotonic increasing
counter for this field and is written on every request irrespective of
userspace value.

Forwarding again the req_id on userspace requests is not a solution because
we would open the possibility of userspace-generated req_id colliding with
kernel ones. So this patch instead takes another route which is to
artificially keep user req_id while keeping the xenbus logic as is. We do
that by saving the original req_id before xs_send(), use the private kernel
counter as req_id and then once reply comes and was validated, we restore
back the original req_id.

Cc: <stable@vger.kernel.org> # 4.11
Fixes: fd8aa909 ("xen: optimize xenbus driver for multiple concurrent xenstore accesses")
Reported-by: Bhavesh Davda <bhavesh.davda@oracle.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

Sparse makes a fair bit of noise about our MPIDR mask being implicitly
long - let's explicitly describe it as such rather than just relying on
the value forcing automatic promotion.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Pull dma-mapping fixes from Christoph Hellwig:
 "A few dma-mapping fixes for the fallout from the changes in rc1"

* tag 'dma-mapping-4.16-2' of git://git.infradead.org/users/hch/dma-mapping:
  powerpc/macio: set a proper dma_coherent_mask
  dma-mapping: fix a comment typo
  dma-direct: comment the dma_direct_free calling convention
  dma-direct: mark as is_phys
  ia64: fix build failure with CONFIG_SWIOTLB

In many cases, page tables can be accessed concurrently by either another
CPU (due to things like fast gup) or by the hardware page table walker
itself, which may set access/dirty bits. In such cases, it is important
to use READ_ONCE/WRITE_ONCE when accessing page table entries so that
entries cannot be torn, merged or subject to apparent loss of coherence
due to compiler transformations.

Whilst there are some scenarios where this cannot happen (e.g. pinned
kernel mappings for the linear region), the overhead of using READ_ONCE
/WRITE_ONCE everywhere is minimal and makes the code an awful lot easier
to reason about. This patch consistently uses these macros in the arch
code, as well as explicitly namespacing pointers to page table entries
from the entries themselves by using adopting a 'p' suffix for the former
(as is sometimes used elsewhere in the kernel source).
Tested-by: Yury Norov <ynorov@caviumnetworks.com>
Tested-by: Richard Ruigrok <rruigrok@codeaurora.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

We get a warning about some slow configurations in randconfig kernels:

  mm/memory.c:83:2: error: #warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid. [-Werror=cpp]

The warning is reasonable by itself, but gets in the way of randconfig
build testing, so I'm hiding it whenever CONFIG_COMPILE_TEST is set.

The warning was added in 2013 in commit 75980e97 ("mm: fold
page->_last_nid into page->flags where possible").

Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>