This is a plain move with identical results, and therefore
still broken in the XIP case.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>

Move common entries to vmlinux.lds.h as ARM_TEXT.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>

Move common entries to vmlinux.lds.h and leave XIP and non-XIP entries
in their respective file. The ARM_NOMMU_KEEP() and ARM_NOMMU_DISCARD()
macros are added to be usable within the definition of ARM_DISCARD macro.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>

Lots of duplications between vmlinux.lds.S and vmlinux-xip.lds.S.
This may lead to one file being updated but not the other. For example,
SOFTIRQENTRY_TEXT and HYPERVISOR_TEXT were missing from the XIP version.

This creates vmlinux.lds.h where a bunch of common defines are moved.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>

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>

Pull MIPS fixes from James Hogan:
 "A few fixes for outstanding MIPS issues:

   - an __init section mismatch warning when brcmstb_pm is enabled

   - a regression handling multiple mem=X@Y arguments (4.11)

   - a USB Kconfig select warning, and related sparc cleanup (4.16)"

* tag 'mips_fixes_4.16_2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
  sparc,leon: Select USB_UHCI_BIG_ENDIAN_{MMIO,DESC}
  usb: Move USB_UHCI_BIG_ENDIAN_* out of USB_SUPPORT
  MIPS: Fix incorrect mem=X@Y handling
  MIPS: BMIPS: Fix section mismatch warning

Pull btrfs fixes from David Sterba:
 "We have a few assorted fixes, some of them show up during fstests so I
  gave them more testing"

* tag 'for-4.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: Fix use-after-free when cleaning up fs_devs with a single stale device
  Btrfs: fix null pointer dereference when replacing missing device
  btrfs: remove spurious WARN_ON(ref->count < 0) in find_parent_nodes
  btrfs: Ignore errors from btrfs_qgroup_trace_extent_post
  Btrfs: fix unexpected -EEXIST when creating new inode
  Btrfs: fix use-after-free on root->orphan_block_rsv
  Btrfs: fix btrfs_evict_inode to handle abnormal inodes correctly
  Btrfs: fix extent state leak from tree log
  Btrfs: fix crash due to not cleaning up tree log block's dirty bits
  Btrfs: fix deadlock in run_delalloc_nocow

Merge tag 'for-4.16/dm-chained-bios-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fix from Mike Snitzer:
 "Fix for DM core to properly propagate errors (avoids overriding
  non-zero error with 0). This is particularly important given DM core's
  increased use of chained bios"

* tag 'for-4.16/dm-chained-bios-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: correctly handle chained bios in dec_pending()

Pull x86 platform driver fixes from Andy Shevchenko:

 - regression fix in keyboard support for Dell laptops

 - prevent out-of-boundary write in WMI bus driver

 - increase timeout to read functional key status on Lenovo laptops

* tag 'platform-drivers-x86-v4.16-4' of git://git.infradead.org/linux-platform-drivers-x86:
  platform/x86: dell-laptop: Removed duplicates in DMI whitelist
  platform/x86: dell-laptop: fix kbd_get_state's request value
  platform/x86: ideapad-laptop: Increase timeout to wait for EC answer
  platform/x86: wmi: fix off-by-one write in wmi_dev_probe()

Pull sound fixes from Takashi Iwai:
 "A collection of usual suspects:

   - a handful USB-audio and HD-audio device-specific quirks

   - some trivial fixes for the new AC97 bus stuff

   - another race fix in ALSA sequencer core"

* tag 'sound-4.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek: PCI quirk for Fujitsu U7x7
  ALSA: seq: Fix racy pool initializations
  ALSA: usb: add more device quirks for USB DSD devices
  ALSA: usb-audio: Fix UAC2 get_ctl request with a RANGE attribute
  ALSA: ac97: Fix copy and paste typo in documentation
  ALSA: usb-audio: add implicit fb quirk for Behringer UFX1204
  ALSA: ac97: kconfig: Remove select of undefined symbol AC97
  ALSA: hda/realtek - Enable Thinkpad Dock device for ALC298 platform
  ALSA: hda/realtek - Add headset mode support for Dell laptop
  ALSA: hda - Fix headset mic detection problem for two Dell machines

Pull drm fixes from Dave Airlie:
 "One nouveau regression fix, one AMD quirk and a full set of i915
  fixes.

  The i915 fixes are mostly for things caught by their CI system, main
  ones being DSI panel fixes and GEM fixes"

* tag 'drm-fixes-for-v4.16-rc2' of git://people.freedesktop.org/~airlied/linux:
  drm/nouveau: Make clock gate support conditional
  drm/i915: Fix DSI panels with v1 MIPI sequences without a DEASSERT sequence v3
  drm/i915: Free memdup-ed DSI VBT data structures on driver_unload
  drm/i915: Add intel_bios_cleanup() function
  drm/i915/vlv: Add cdclk workaround for DSI
  drm/i915/gvt: fix one typo of render_mmio trace
  drm/i915/gvt: Support BAR0 8-byte reads/writes
  drm/i915/gvt: add 0xe4f0 into gen9 render list
  drm/i915/pmu: Fix building without CONFIG_PM
  drm/i915/pmu: Fix sleep under atomic in RC6 readout
  drm/i915/pmu: Fix PMU enable vs execlists tasklet race
  drm/i915: Lock out execlist tasklet while peeking inside for busy-stats
  drm/i915/breadcrumbs: Ignore unsubmitted signalers
  drm/i915: Don't wake the device up to check if the engine is asleep
  drm/i915: Avoid truncation before clamping userspace's priority value
  drm/i915/perf: Fix compiler warning for string truncation
  drm/i915/perf: Fix compiler warning for string truncation
  drm/amdgpu: add new device to use atpx quirk

dec_pending() is given an error status (possibly 0) to be recorded
against a bio.  It can be called several times on the one 'struct
dm_io', and it is careful to only assign a non-zero error to
io->status.  However when it then assigned io->status to bio->bi_status,
it is not careful and could overwrite a genuine error status with 0.

This can happen when chained bios are in use.  If a bio is chained
beneath the bio that this dm_io is handling, the child bio might
complete and set bio->bi_status before the dm_io completes.

This has been possible since chained bios were introduced in 3.14, and
has become a lot easier to trigger with commit 18a25da8 ("dm: ensure
bio submission follows a depth-first tree walk") as that commit caused
dm to start using chained bios itself.

A particular failure mode is that if a bio spans an 'error' target and a
working target, the 'error' fragment will complete instantly and set the
->bi_status, and the other fragment will normally complete a little
later, and will clear ->bi_status.

The fix is simply to only assign io_error to bio->bi_status when
io_error is not zero.
Reported-and-tested-by: Milan Broz <gmazyland@gmail.com>
Cc: stable@vger.kernel.org (v3.14+)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Merge tag 'irqchip-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull irqchip updates for 4.16-rc2 from Marc Zyngier

 - A MIPS GIC fix for spurious, masked interrupts
 - A fix for a subtle IPI bug in GICv3
 - Do not probe GICv3 ITSs that are marked as disabled
 - Multi-MSI support for GICv2m
 - Various cleanups

...instead of open coding file operations followed by custom ->open()
callbacks per each attribute.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Since commit ad67b74d ("printk: hash addresses printed with %p")
pointers are being hashed when printed. Displaying the virtual memory at
bootup time is not helpful. so delete the prints.
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

We'd never implemented Multi-MSI support with GICv2m, because
it is weird and clunky, and you'd think people would rather use
MSI-X.

Turns out there is still plenty of devices out there that rely
on Multi-MSI. Oh well, let's teach that trick to the v2m widget,
it is not a big deal anyway.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

On some platforms there's an ITS available but it's not enabled
because reading or writing the registers is denied by the
firmware. In fact, reading or writing them will cause the system
to reset. We could remove the node from DT in such a case, but
it's better to skip nodes that are marked as "disabled" in DT so
that we can describe the hardware that exists and use the status
property to indicate how the firmware has configured things.

Cc: Stuart Yoder <stuyoder@gmail.com>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

A DMB instruction can be used to ensure the relative order of only
memory accesses before and after the barrier. Since writes to system
registers are not memory operations, barrier DMB is not sufficient
for observability of memory accesses that occur before ICC_SGI1R_EL1
writes.

A DSB instruction ensures that no instructions that appear in program
order after the DSB instruction, can execute until the DSB instruction
has completed.

Cc: stable@vger.kernel.org
Acked-by: Will Deacon <will.deacon@arm.com>,
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

The pr_debug() in gic-v3 gic_send_sgi() can trigger a circular locking
warning:

 GICv3: CPU10: ICC_SGI1R_EL1 5000400
 ======================================================
 WARNING: possible circular locking dependency detected
 4.15.0+ #1 Tainted: G        W
 ------------------------------------------------------
 dynamic_debug01/1873 is trying to acquire lock:
  ((console_sem).lock){-...}, at: [<0000000099c891ec>] down_trylock+0x20/0x4c

 but task is already holding lock:
  (&rq->lock){-.-.}, at: [<00000000842e1587>] __task_rq_lock+0x54/0xdc

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #2 (&rq->lock){-.-.}:
        __lock_acquire+0x3b4/0x6e0
        lock_acquire+0xf4/0x2a8
        _raw_spin_lock+0x4c/0x60
        task_fork_fair+0x3c/0x148
        sched_fork+0x10c/0x214
        copy_process.isra.32.part.33+0x4e8/0x14f0
        _do_fork+0xe8/0x78c
        kernel_thread+0x48/0x54
        rest_init+0x34/0x2a4
        start_kernel+0x45c/0x488

 -> #1 (&p->pi_lock){-.-.}:
        __lock_acquire+0x3b4/0x6e0
        lock_acquire+0xf4/0x2a8
        _raw_spin_lock_irqsave+0x58/0x70
        try_to_wake_up+0x48/0x600
        wake_up_process+0x28/0x34
        __up.isra.0+0x60/0x6c
        up+0x60/0x68
        __up_console_sem+0x4c/0x7c
        console_unlock+0x328/0x634
        vprintk_emit+0x25c/0x390
        dev_vprintk_emit+0xc4/0x1fc
        dev_printk_emit+0x88/0xa8
        __dev_printk+0x58/0x9c
        _dev_info+0x84/0xa8
        usb_new_device+0x100/0x474
        hub_port_connect+0x280/0x92c
        hub_event+0x740/0xa84
        process_one_work+0x240/0x70c
        worker_thread+0x60/0x400
        kthread+0x110/0x13c
        ret_from_fork+0x10/0x18

 -> #0 ((console_sem).lock){-...}:
        validate_chain.isra.34+0x6e4/0xa20
        __lock_acquire+0x3b4/0x6e0
        lock_acquire+0xf4/0x2a8
        _raw_spin_lock_irqsave+0x58/0x70
        down_trylock+0x20/0x4c
        __down_trylock_console_sem+0x3c/0x9c
        console_trylock+0x20/0xb0
        vprintk_emit+0x254/0x390
        vprintk_default+0x58/0x90
        vprintk_func+0xbc/0x164
        printk+0x80/0xa0
        __dynamic_pr_debug+0x84/0xac
        gic_raise_softirq+0x184/0x18c
        smp_cross_call+0xac/0x218
        smp_send_reschedule+0x3c/0x48
        resched_curr+0x60/0x9c
        check_preempt_curr+0x70/0xdc
        wake_up_new_task+0x310/0x470
        _do_fork+0x188/0x78c
        SyS_clone+0x44/0x50
        __sys_trace_return+0x0/0x4

 other info that might help us debug this:

 Chain exists of:
   (console_sem).lock --> &p->pi_lock --> &rq->lock

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&rq->lock);
                                lock(&p->pi_lock);
                                lock(&rq->lock);
   lock((console_sem).lock);

  *** DEADLOCK ***

 2 locks held by dynamic_debug01/1873:
  #0:  (&p->pi_lock){-.-.}, at: [<000000001366df53>] wake_up_new_task+0x40/0x470
  #1:  (&rq->lock){-.-.}, at: [<00000000842e1587>] __task_rq_lock+0x54/0xdc

 stack backtrace:
 CPU: 10 PID: 1873 Comm: dynamic_debug01 Tainted: G        W        4.15.0+ #1
 Hardware name: GIGABYTE R120-T34-00/MT30-GS2-00, BIOS T48 10/02/2017
 Call trace:
  dump_backtrace+0x0/0x188
  show_stack+0x24/0x2c
  dump_stack+0xa4/0xe0
  print_circular_bug.isra.31+0x29c/0x2b8
  check_prev_add.constprop.39+0x6c8/0x6dc
  validate_chain.isra.34+0x6e4/0xa20
  __lock_acquire+0x3b4/0x6e0
  lock_acquire+0xf4/0x2a8
  _raw_spin_lock_irqsave+0x58/0x70
  down_trylock+0x20/0x4c
  __down_trylock_console_sem+0x3c/0x9c
  console_trylock+0x20/0xb0
  vprintk_emit+0x254/0x390
  vprintk_default+0x58/0x90
  vprintk_func+0xbc/0x164
  printk+0x80/0xa0
  __dynamic_pr_debug+0x84/0xac
  gic_raise_softirq+0x184/0x18c
  smp_cross_call+0xac/0x218
  smp_send_reschedule+0x3c/0x48
  resched_curr+0x60/0x9c
  check_preempt_curr+0x70/0xdc
  wake_up_new_task+0x310/0x470
  _do_fork+0x188/0x78c
  SyS_clone+0x44/0x50
  __sys_trace_return+0x0/0x4
 GICv3: CPU0: ICC_SGI1R_EL1 12000

This could be fixed with printk_deferred() but that might lessen its
usefulness for debugging. So change it to pr_devel to keep it out of
production kernels. Developers working on gic-v3 can enable it as
needed in their kernels.
Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Commit 7778c4b2 ("irqchip: mips-gic: Use pcpu_masks to avoid reading
GIC_SH_MASK*") removed the read of the hardware mask register when
handling shared interrupts, instead using the driver's shadow pcpu_masks
entry as the effective mask. Unfortunately this did not take account of
the write to pcpu_masks during gic_shared_irq_domain_map, which
effectively unmasks the interrupt early. If an interrupt is asserted,
gic_handle_shared_int decodes and processes the interrupt even though it
has not yet been unmasked via gic_unmask_irq, which also sets the
appropriate bit in pcpu_masks.

On the MIPS Boston board, when a console command line of
"console=ttyS0,115200n8r" is passed, the modem status IRQ is enabled in
the UART, which is immediately raised to the GIC. The interrupt has been
mapped, but no handler has yet been registered, nor is it expected to be
unmasked. However, the write to pcpu_masks in gic_shared_irq_domain_map
has effectively unmasked it, resulting in endless reports of:

[    5.058454] irq 13, desc: ffffffff80a7ad80, depth: 1, count: 0, unhandled: 0
[    5.062057] ->handle_irq():  ffffffff801b1838,
[    5.062175] handle_bad_irq+0x0/0x2c0

Where IRQ 13 is the UART interrupt.

To fix this, just remove the write to pcpu_masks in
gic_shared_irq_domain_map. The existing write in gic_unmask_irq is the
correct place for what is now the effective unmasking.

Cc: stable@vger.kernel.org
Fixes: 7778c4b2 ("irqchip: mips-gic: Use pcpu_masks to avoid reading GIC_SH_MASK*")
Signed-off-by: Matt Redfearn <matt.redfearn@mips.com>
Reviewed-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>