1. 11 2月, 2016 3 次提交
  2. 09 2月, 2016 3 次提交
    • D
      drm/tegra: drop unused variable. · 10c1b618
      Dave Airlie 提交于
      Fixes: 0417d424 (drm/tegra: Stop cancelling page flip events)
      Signed-off-by: NDave Airlie <airlied@redhat.com>
      10c1b618
    • D
      Merge tag 'topic/drm-misc-2016-02-08' of git://anongit.freedesktop.org/drm-intel into drm-next · 316e376b
      Dave Airlie 提交于
      First drm-misc pull req for 4.6. Big one is the drm_event cleanup, which
      is also prep work for adding android fence support to kms (Gustavo is
      planning to do that). Otherwise random small bits all over.
      
      * tag 'topic/drm-misc-2016-02-08' of git://anongit.freedesktop.org/drm-intel: (33 commits)
        gma500: clean up an excessive and confusing helper
        drm/gma500: remove helper function
        drm/vmwgfx: Nuke preclose hook
        drm/vc4: Nuke preclose hook
        drm/tilcdc: Nuke preclose hook
        drm/tegra: Stop cancelling page flip events
        drm/shmob: Nuke preclose hook
        drm/rcar: Nuke preclose hook
        drm/omap: Nuke close hooks
        drm/msm: Nuke preclose hooks
        drm/imx: Unconfuse preclose logic
        drm/exynos: Remove event cancelling from postclose
        drm/atmel: Nuke preclose
        drm/i915: Nuke intel_modeset_preclose
        drm: Nuke vblank event file cleanup code
        drm: Clean up pending events in the core
        drm/vblank: Use drm_event_reserve_init
        drm/vmwgfx: fix a NULL dereference
        drm/crtc-helper: Add caveat to disable_unused_functions doc
        drm/gma500: Remove empty preclose hook
        ...
      316e376b
    • D
      Merge tag 'drm-intel-next-2016-01-24' of git://anongit.freedesktop.org/drm-intel into drm-next · b039d6d0
      Dave Airlie 提交于
      - support for v3 vbt dsi blocks (Jani)
      - improve mmio debug checks (Mika Kuoppala)
      - reorg the ddi port translation table entries and related code (Ville)
      - reorg gen8 interrupt handling for future platforms (Tvrtko)
      - refactor tile width/height computations for framebuffers (Ville)
      - kerneldoc integration for intel_pm.c (Jani)
      - move default context from engines to device-global dev_priv (Dave Gordon)
      - make seqno/irq ordering coherent with execlist (Chris)
      - decouple internal engine number from UABI (Chris&Tvrtko)
      - tons of small fixes all over, as usual
      
      * tag 'drm-intel-next-2016-01-24' of git://anongit.freedesktop.org/drm-intel: (148 commits)
        drm/i915: Update DRIVER_DATE to 20160124
        drm/i915: Seal busy-ioctl uABI and prevent leaking of internal ids
        drm/i915: Decouple execbuf uAPI from internal implementation
        drm/i915: Use ordered seqno write interrupt generation on gen8+ execlists
        drm/i915: Limit the auto arming of mmio debugs on vlv/chv
        drm/i915: Tune down "GT register while GT waking disabled" message
        drm/i915: tidy up a few leftovers
        drm/i915: abolish separate per-ring default_context pointers
        drm/i915: simplify allocation of driver-internal requests
        drm/i915: Fix NULL plane->fb oops on SKL
        drm/i915: Do not put big intel_crtc_state on the stack
        Revert "drm/i915: Add two-stage ILK-style watermark programming (v10)"
        drm/i915: add DOC: headline to RC6 kernel-doc
        drm/i915: turn some bogus kernel-doc comments to normal comments
        drm/i915/sdvo: revert bogus kernel-doc comments to normal comments
        drm/i915/gen9: Correct max save/restore register count during gpu reset with GuC
        drm/i915: Demote user facing DMC firmware load failure message
        drm/i915: use hlist_for_each_entry
        drm/i915: skl_update_scaler() wants a rotation bitmask instead of bit number
        drm/i915: Don't reject primary plane windowing with color keying enabled on SKL+
        ...
      b039d6d0
  3. 08 2月, 2016 20 次提交
  4. 07 2月, 2016 2 次提交
    • L
      Merge tag 'usb-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb · 46df55ce
      Linus Torvalds 提交于
      Pull USB fixes from Greg KH:
       "Here are some USB fixes for 4.5-rc3.
      
        The usual, xhci fixes for reported issues, combined with some small
        gadget driver fixes, and a MAINTAINERS file update.  All have been in
        linux-next with no reported issues"
      
      * tag 'usb-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
        xhci: harden xhci_find_next_ext_cap against device removal
        xhci: Fix list corruption in urb dequeue at host removal
        usb: host: xhci-plat: fix NULL pointer in probe for device tree case
        usb: xhci-mtk: fix AHB bus hang up caused by roothubs polling
        usb: xhci-mtk: fix bpkts value of LS/HS periodic eps not behind TT
        usb: xhci: apply XHCI_PME_STUCK_QUIRK to Intel Broxton-M platforms
        usb: xhci: set SSIC port unused only if xhci_suspend succeeds
        usb: xhci: add a quirk bit for ssic port unused
        usb: xhci: handle both SSIC ports in PME stuck quirk
        usb: dwc3: gadget: set the OTG flag in dwc3 gadget driver.
        Revert "xhci: don't finish a TD if we get a short-transfer event mid TD"
        MAINTAINERS: fix my email address
        usb: dwc2: Fix probe problem on bcm2835
        Revert "usb: dwc2: Move reset into dwc2_get_hwparams()"
        usb: musb: ux500: Fix NULL pointer dereference at system PM
        usb: phy: mxs: declare variable with initialized value
        usb: phy: msm: fix error handling in probe.
      46df55ce
    • L
      Merge tag 'staging-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging · dacd53c8
      Linus Torvalds 提交于
      Pull staging and IIO driver fixes from Greg KH:
       "Here are some IIO and staging driver fixes for 4.5-rc3.
      
        All of them, except one, are for IIO drivers, and one is for a speakup
        driver fix caused by some earlier patches, to resolve a reported build
        failure"
      
      * tag 'staging-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
        Staging: speakup: Fix allyesconfig build on mn10300
        iio: dht11: Use boottime
        iio: ade7753: avoid uninitialized data
        iio: pressure: mpl115: fix temperature offset sign
        iio: imu: Fix dependencies for !HAS_IOMEM archs
        staging: iio: Fix dependencies for !HAS_IOMEM archs
        iio: adc: Fix dependencies for !HAS_IOMEM archs
        iio: inkern: fix a NULL dereference on error
        iio:adc:ti_am335x_adc Fix buffered mode by identifying as software buffer.
        iio: light: acpi-als: Report data as processed
        iio: dac: mcp4725: set iio name property in sysfs
        iio: add HAS_IOMEM dependency to VF610_ADC
        iio: add IIO_TRIGGER dependency to STK8BA50
        iio: proximity: lidar: correct return value
        iio-light: Use a signed return type for ltr501_match_samp_freq()
      dacd53c8
  5. 06 2月, 2016 12 次提交
    • L
      Merge branch 'akpm' (patches from Andrew) · 5af9c2e1
      Linus Torvalds 提交于
      Merge fixes from Andrew Morton:
       "22 fixes"
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (22 commits)
        epoll: restrict EPOLLEXCLUSIVE to POLLIN and POLLOUT
        radix-tree: fix oops after radix_tree_iter_retry
        MAINTAINERS: trim the file triggers for ABI/API
        dax: dirty inode only if required
        thp: make deferred_split_scan() work again
        mm: replace vma_lock_anon_vma with anon_vma_lock_read/write
        ocfs2/dlm: clear refmap bit of recovery lock while doing local recovery cleanup
        um: asm/page.h: remove the pte_high member from struct pte_t
        mm, hugetlb: don't require CMA for runtime gigantic pages
        mm/hugetlb: fix gigantic page initialization/allocation
        mm: downgrade VM_BUG in isolate_lru_page() to warning
        mempolicy: do not try to queue pages from !vma_migratable()
        mm, vmstat: fix wrong WQ sleep when memory reclaim doesn't make any progress
        vmstat: make vmstat_update deferrable
        mm, vmstat: make quiet_vmstat lighter
        mm/Kconfig: correct description of DEFERRED_STRUCT_PAGE_INIT
        memblock: don't mark memblock_phys_mem_size() as __init
        dump_stack: avoid potential deadlocks
        mm: validate_mm browse_rb SMP race condition
        m32r: fix build failure due to SMP and MMU
        ...
      5af9c2e1
    • L
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client · 5d6a6a75
      Linus Torvalds 提交于
      Pull Ceph fixes from Sage Weil:
       "We have a few wire protocol compatibility fixes, ports of a few recent
        CRUSH mapping changes, and a couple error path fixes"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
        libceph: MOSDOpReply v7 encoding
        libceph: advertise support for TUNABLES5
        crush: decode and initialize chooseleaf_stable
        crush: add chooseleaf_stable tunable
        crush: ensure take bucket value is valid
        crush: ensure bucket id is valid before indexing buckets array
        ceph: fix snap context leak in error path
        ceph: checking for IS_ERR instead of NULL
      5d6a6a75
    • L
      Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux · 9b108828
      Linus Torvalds 提交于
      Pull drm fixes from Dave Airlie:
       "Fixes all over the place:
      
         - amdkfd: two static checker fixes
         - mst: a bunch of static checker and spec/hw interaction fixes
         - amdgpu: fix Iceland hw properly, and some fiji bugs, along with
           some write-combining fixes.
         - exynos: some regression fixes
         - adv7511: fix some EDID reading issues"
      
      * 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (38 commits)
        drm/dp/mst: deallocate payload on port destruction
        drm/dp/mst: Reverse order of MST enable and clearing VC payload table.
        drm/dp/mst: move GUID storage from mgr, port to only mst branch
        drm/dp/mst: change MST detection scheme
        drm/dp/mst: Calculate MST PBN with 31.32 fixed point
        drm: Add drm_fixp_from_fraction and drm_fixp2int_ceil
        drm/mst: Add range check for max_payloads during init
        drm/mst: Don't ignore the MST PBN self-test result
        drm: fix missing reference counting decrease
        drm/amdgpu: disable uvd and vce clockgating on Fiji
        drm/amdgpu: remove exp hardware support from iceland
        drm/amdgpu: load MEC ucode manually on iceland
        drm/amdgpu: don't load MEC2 on topaz
        drm/amdgpu: drop topaz support from gmc8 module
        drm/amdgpu: pull topaz gmc bits into gmc_v7
        drm/amdgpu: The VI specific EXE bit should only apply to GMC v8.0 above
        drm/amdgpu: iceland use CI based MC IP
        drm/amdgpu: move gmc7 support out of CIK dependency
        drm/amdgpu/gfx7: enable cp inst/reg error interrupts
        drm/amdgpu/gfx8: enable cp inst/reg error interrupts
        ...
      9b108828
    • L
      Merge tag 'pm+acpi-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm · 22f60701
      Linus Torvalds 提交于
      Pull power management and ACPI fixes from Rafael Wysocki:
       "These are: a fix for a recently introduced false-positive warnings
        about PM domain pointers being changed inappropriately (harmless but
        annoying), an MCH size workaround quirk for one more platform, a
        compiler warning fix (generic power domains framework), an ACPI LPSS
        (Intel SoCs) driver fixup and a cleanup of the ACPI CPPC core code.
      
        Specifics:
      
         - PM core fix to avoid false-positive warnings generated when the
           pm_domain field is cleared for a device that appears to be bound to
           a driver (Rafael Wysocki).
      
         - New MCH size workaround quirk for Intel Haswell-ULT (Josh Boyer).
      
         - Fix for an "unused function" compiler warning in the generic power
           domains framework (Ulf Hansson).
      
         - Fixup for the ACPI driver for Intel SoCs (acpi-lpss) to set the PM
           domain pointer of a device properly in one place that was
           overlooked by a recent PM core update (Andy Shevchenko).
      
         - Removal of a redundant function declaration in the ACPI CPPC core
           code (Timur Tabi)"
      
      * tag 'pm+acpi-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
        PM: Avoid false-positive warnings in dev_pm_domain_set()
        PM / Domains: Silence compiler warning for an unused function
        ACPI / CPPC: remove redundant mbox_send_message() declaration
        ACPI / LPSS: set PM domain via helper setter
        PNP: Add Haswell-ULT to Intel MCH size workaround
      22f60701
    • J
      epoll: restrict EPOLLEXCLUSIVE to POLLIN and POLLOUT · b6a515c8
      Jason Baron 提交于
      In the current implementation of the EPOLLEXCLUSIVE flag (added for
      4.5-rc1), if epoll waiters create different POLL* sets and register them
      as exclusive against the same target fd, the current implementation will
      stop waking any further waiters once it finds the first idle waiter.
      This means that waiters could miss wakeups in certain cases.
      
      For example, when we wake up a pipe for reading we do:
      wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM); So if
      one epoll set or epfd is added to pipe p with POLLIN and a second set
      epfd2 is added to pipe p with POLLRDNORM, only epfd may receive the
      wakeup since the current implementation will stop after it finds any
      intersection of events with a waiter that is blocked in epoll_wait().
      
      We could potentially address this by requiring all epoll waiters that
      are added to p be required to pass the same set of POLL* events.  IE the
      first EPOLL_CTL_ADD that passes EPOLLEXCLUSIVE establishes the set POLL*
      flags to be used by any other epfds that are added as EPOLLEXCLUSIVE.
      However, I think it might be somewhat confusing interface as we would
      have to reference count the number of users for that set, and so
      userspace would have to keep track of that count, or we would need a
      more involved interface.  It also adds some shared state that we'd have
      store somewhere.  I don't think anybody will want to bloat
      __wait_queue_head for this.
      
      I think what we could do instead, is to simply restrict EPOLLEXCLUSIVE
      such that it can only be specified with EPOLLIN and/or EPOLLOUT.  So
      that way if the wakeup includes 'POLLIN' and not 'POLLOUT', we can stop
      once we hit the first idle waiter that specifies the EPOLLIN bit, since
      any remaining waiters that only have 'POLLOUT' set wouldn't need to be
      woken.  Likewise, we can do the same thing if 'POLLOUT' is in the wakeup
      bit set and not 'POLLIN'.  If both 'POLLOUT' and 'POLLIN' are set in the
      wake bit set (there is at least one example of this I saw in fs/pipe.c),
      then we just wake the entire exclusive list.  Having both 'POLLOUT' and
      'POLLIN' both set should not be on any performance critical path, so I
      think that's ok (in fs/pipe.c its in pipe_release()).  We also continue
      to include EPOLLERR and EPOLLHUP by default in any exclusive set.  Thus,
      the user can specify EPOLLERR and/or EPOLLHUP but is not required to do
      so.
      
      Since epoll waiters may be interested in other events as well besides
      EPOLLIN, EPOLLOUT, EPOLLERR and EPOLLHUP, these can still be added by
      doing a 'dup' call on the target fd and adding that as one normally
      would with EPOLL_CTL_ADD.  Since I think that the POLLIN and POLLOUT
      events are what we are interest in balancing, I think that the 'dup'
      thing could perhaps be added to only one of the waiter threads.
      However, I think that EPOLLIN, EPOLLOUT, EPOLLERR and EPOLLHUP should be
      sufficient for the majority of use-cases.
      
      Since EPOLLEXCLUSIVE is intended to be used with a target fd shared
      among multiple epfds, where between 1 and n of the epfds may receive an
      event, it does not satisfy the semantics of EPOLLONESHOT where only 1
      epfd would get an event.  Thus, it is not allowed to be specified in
      conjunction with EPOLLEXCLUSIVE.
      
      EPOLL_CTL_MOD is also not allowed if the fd was previously added as
      EPOLLEXCLUSIVE.  It seems with the limited number of flags to not be as
      interesting, but this could be relaxed at some further point.
      Signed-off-by: NJason Baron <jbaron@akamai.com>
      Tested-by: NMadars Vitolins <m@silodev.com>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Al Viro <viro@ftp.linux.org.uk>
      Cc: Eric Wong <normalperson@yhbt.net>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Hagen Paul Pfeifer <hagen@jauu.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b6a515c8
    • K
      radix-tree: fix oops after radix_tree_iter_retry · 73204282
      Konstantin Khlebnikov 提交于
      Helper radix_tree_iter_retry() resets next_index to the current index.
      In following radix_tree_next_slot current chunk size becomes zero.  This
      isn't checked and it tries to dereference null pointer in slot.
      
      Tagged iterator is fine because retry happens only at slot 0 where tag
      bitmask in iter->tags is filled with single bit.
      
      Fixes: 46437f9a ("radix-tree: fix race in gang lookup")
      Signed-off-by: NKonstantin Khlebnikov <koct9i@gmail.com>
      Cc: Matthew Wilcox <willy@linux.intel.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Ohad Ben-Cohen <ohad@wizery.com>
      Cc: Jeremiah Mahler <jmmahler@gmail.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      73204282
    • M
      MAINTAINERS: trim the file triggers for ABI/API · b14fd334
      Michael Kerrisk (man-pages) 提交于
      Commit ea8f8fc8 ("MAINTAINERS: add linux-api for review of API/ABI
      changes") added file triggers for various paths that likely indicated
      API/ABI changes.  However, catching all changes in Documentation/ABI/
      and include/uapi/ produces a large volume of mail to linux-api, rather
      than only API/ABI changes.  Drop those two entries, but leave
      include/linux/syscalls.h and kernel/sys_ni.c to catch syscall-related
      changes.
      
      [josh@joshtriplett.org: redid changelog]
      Signed-off-by: NMichael Kerrisk <mtk.man-pages@gmail.com>
      Acked-by: NShuah khan <shuahkh@osg.samsung.com>
      Cc: Josh Triplett <josh@joshtriplett.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b14fd334
    • D
      dax: dirty inode only if required · d2b2a28e
      Dmitry Monakhov 提交于
      Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
      Reviewed-by: NJan Kara <jack@suse.cz>
      Reviewed-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
      Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d2b2a28e
    • K
      thp: make deferred_split_scan() work again · ae026204
      Kirill A. Shutemov 提交于
      We need to iterate over split_queue, not local empty list to get
      anything split from the shrinker.
      
      Fixes: e3ae1953 ("thp: limit number of object to scan on deferred_split_scan()")
      Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ae026204
    • K
      mm: replace vma_lock_anon_vma with anon_vma_lock_read/write · 12352d3c
      Konstantin Khlebnikov 提交于
      Sequence vma_lock_anon_vma() - vma_unlock_anon_vma() isn't safe if
      anon_vma appeared between lock and unlock.  We have to check anon_vma
      first or call anon_vma_prepare() to be sure that it's here.  There are
      only few users of these legacy helpers.  Let's get rid of them.
      
      This patch fixes anon_vma lock imbalance in validate_mm().  Write lock
      isn't required here, read lock is enough.
      
      And reorders expand_downwards/expand_upwards: security_mmap_addr() and
      wrapping-around check don't have to be under anon vma lock.
      
      Link: https://lkml.kernel.org/r/CACT4Y+Y908EjM2z=706dv4rV6dWtxTLK9nFg9_7DhRMLppBo2g@mail.gmail.comSigned-off-by: NKonstantin Khlebnikov <koct9i@gmail.com>
      Reported-by: NDmitry Vyukov <dvyukov@google.com>
      Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      12352d3c
    • X
      ocfs2/dlm: clear refmap bit of recovery lock while doing local recovery cleanup · c95a5180
      xuejiufei 提交于
      When recovery master down, dlm_do_local_recovery_cleanup() only remove
      the $RECOVERY lock owned by dead node, but do not clear the refmap bit.
      Which will make umount thread falling in dead loop migrating $RECOVERY
      to the dead node.
      Signed-off-by: Nxuejiufei <xuejiufei@huawei.com>
      Reviewed-by: NJoseph Qi <joseph.qi@huawei.com>
      Cc: Mark Fasheh <mfasheh@suse.de>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Junxiao Bi <junxiao.bi@oracle.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c95a5180
    • N
      um: asm/page.h: remove the pte_high member from struct pte_t · 012a4163
      Nicolai Stange 提交于
      Commit 16da3068 ("um: kill pfn_t") introduced a compile warning for
      defconfig (SUBARCH=i386):
      
        arch/um/kernel/skas/mmu.c:38:206:
            warning: right shift count >= width of type [-Wshift-count-overflow]
      
      Aforementioned patch changes the definition of the phys_to_pfn() macro
      from
      
        ((pfn_t) ((p) >> PAGE_SHIFT))
      
      to
      
        ((p) >> PAGE_SHIFT)
      
      This effectively changes the phys_to_pfn() expansion's type from
      unsigned long long to unsigned long.
      
      Through the callchain init_stub_pte() => mk_pte(), the expansion of
      phys_to_pfn() is (indirectly) fed into the 'phys' argument of the
      pte_set_val(pte, phys, prot) macro, eventually leading to
      
        (pte).pte_high = (phys) >> 32;
      
      This results in the warning from above.
      
      Since UML only deals with 32 bit addresses, the upper 32 bits from
      'phys' used to be always zero anyway.  Also, all page protection flags
      defined by UML don't use any bits beyond bit 9.  Since the contents of a
      PTE are defined within architecture scope only, the ->pte_high member
      can be safely removed.
      
      Remove the ->pte_high member from struct pte_t.
      Rename ->pte_low to ->pte.
      Adapt the pte helper macros in arch/um/include/asm/page.h.
      
      Noteworthy is the pte_copy() macro where a smp_wmb() gets dropped.  This
      write barrier doesn't seem to be paired with any read barrier though and
      thus, was useless anyway.
      
      Fixes: 16da3068 ("um: kill pfn_t")
      Signed-off-by: NNicolai Stange <nicstange@gmail.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Nicolai Stange <nicstange@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      012a4163