mm/migrate.c: rework migration_entry_wait() to not take a pageref

This fixes the FIXME in migrate_vma_check_page().

Before migrating a page migration code will take a reference and check
there are no unexpected page references, failing the migration if there
are.  When a thread faults on a migration entry it will take a temporary
reference to the page to wait for the page to become unlocked signifying
the migration entry has been removed.

This reference is dropped just prior to waiting on the page lock, however
the extra reference can cause migration failures so it is desirable to
avoid taking it.

As migration code already has a reference to the migrating page an extra
reference to wait on PG_locked is unnecessary so long as the reference
can't be dropped whilst setting up the wait.

When faulting on a migration entry the ptl is taken to check the migration
entry.  Removing a migration entry also requires the ptl, and migration
code won't drop its page reference until after the migration entry has
been removed.  Therefore retaining the ptl of a migration entry is
sufficient to ensure the page has a reference.  Reworking
migration_entry_wait() to hold the ptl until the wait setup is complete
means the extra page reference is no longer needed.

[apopple@nvidia.com: v5]
Link: https://lkml.kernel.org/r/20211213033848.1973946-1-apopple@nvidia.com
Link: https://lkml.kernel.org/r/20211118020754.954425-1-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

fs/f2fs/data.c: fix mess

fs/f2fs/data.c: In function 'f2fs_read_single_page':
fs/f2fs/data.c:2092:1: error: label 'confused' defined but not used [-Werror=unused-label]
 2092 | confused:
      | ^~~~~~~~

Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

Merge branch 'akpm-current/current'

Merge branch 'master' of git://git./linux/kernel/git/crng/random.git

Merge branch 'for-next' of git://git./linux/kernel/git/vbabka/slab.git

Merge branch 'bitmap-master-5.15' of https://guthub.com/norov/linux.git

# Conflicts:
# arch/parisc/include/asm/bitops.h
# arch/powerpc/include/asm/cputhreads.h
# arch/s390/kvm/kvm-s390.c
# drivers/dma/ti/edma.c

Merge branch 'for-next' of git://git.infradead.org/users/willy/pagecache.git

Merge branch 'rust-next' of https://github.com/Rust-for-Linux/linux.git

# Conflicts:
# Documentation/process/changes.rst
# samples/Kconfig
# samples/Makefile

Merge branch 'mhi-next' of git://git./linux/kernel/git/mani/mhi.git

Merge branch 'main' of git://git.infradead.org/users/willy/xarray.git

Merge branch 'for-next' of git://git./linux/kernel/git/srini/nvmem.git

Merge branch 'ntb-next' of https://github.com/jonmason/ntb.git

Merge branch 'rtc-next' of git://git./linux/kernel/git/abelloni/linux.git

Merge branch 'for-next' of git://git./linux/kernel/git/livepatching/livepatching

Merge branch 'for-next' of git://git./linux/kernel/git/thierry.reding/linux-pwm.git

Merge branch 'for-next' of git://git./linux/kernel/git/linusw/linux-pinctrl.git

Merge branch 'for-next' of git://git./linux/kernel/git/remoteproc/linux.git

Merge branch 'linux-next' of git://git./linux/kernel/git/mst/vhost.git

Merge branch 'for-next' of git://git./linux/kernel/git/mkp/scsi.git

Merge branch 'for-next' of git://git./linux/kernel/git/jejb/scsi.git

Merge branch 'for-next' of git://git./linux/kernel/git/tj/cgroup.git

Merge branch 'next' of git://git./linux/kernel/git/vkoul/dmaengine.git

Merge branch 'next' of git://github.com/awilliam/linux-vfio.git

Merge branch 'for-usb-next' of git://git./linux/kernel/git/peter.chen/usb.git

Merge branch 'for-next' of git://github.com/cminyard/linux-ipmi.git

Merge branch 'for-next' of git://git./linux/kernel/git/pavel/linux-leds.git

Merge branch 'for-next' of git://git./linux/kernel/git/tj/wq.git

Merge branch 'for-next' of git://git./linux/kernel/git/dennis/percpu.git

Merge branch 'rcu/next' of git://git./linux/kernel/git/paulmck/linux-rcu.git

Merge branch 'edac-for-next' of git://git./linux/kernel/git/ras/ras.git

Merge branch 'auto-latest' of git://git./linux/kernel/git/tip/tip.git

Merge branch 'for-next' of git://git./linux/kernel/git/robh/linux.git

# Conflicts:
# Documentation/devicetree/bindings/vendor-prefixes.yaml

Merge branch 'apparmor-next' of git://git./linux/kernel/git/jj/linux-apparmor

Merge branch 'next-testing' of git://git./linux/kernel/git/jmorris/linux-security.git

Merge branch 'for-next' of git://git./linux/kernel/git/dlemoal/libata.git

Merge branch 'for-next' of git://git.kernel.dk/linux-block.git

Merge branch 'for-next' of git://git./linux/kernel/git/deller/linux-fbdev.git

Merge branch 'imx-drm/next' of https://git.pengutronix.de/git/pza/linux

Merge branch 'for-linux-next' of git://anongit.freedesktop.org/drm-intel

Merge branch 'drm-next' of https://gitlab.freedesktop.org/agd5f/linux

Merge branch 'master' of git://git./linux/kernel/git/bluetooth/bluetooth-next.git

Merge branch 'cpupower' of git://git./linux/kernel/git/shuah/linux.git

Merge branches 'hwspinlock-next', 'rproc-fixes' and 'rpmsg-fixes' into for-next

remoteproc: qcom: q6v5: fix service routines build errors

When CONFIG_QCOM_AOSS_QMP=m and CONFIG_QCOM_Q6V5_MSS=y, the builtin
driver cannot call into the loadable module's low-level service
functions. Trying to build with that config combo causes linker errors.

There are two problems here. First, drivers/remoteproc/qcom_q6v5.c
should #include <linux/soc/qcom/qcom_aoss.h> for the definitions of
the service functions, depending on whether CONFIG_QCOM_AOSS_QMP is
set/enabled or not. Second, the qcom remoteproc drivers should depend
on QCOM_AOSS_QMP iff it is enabled (=y or =m) so that the qcom
remoteproc drivers can be built properly.

This prevents these build errors:

aarch64-linux-ld: drivers/remoteproc/qcom_q6v5.o: in function `q6v5_load_state_toggle':
qcom_q6v5.c:(.text+0xc4): undefined reference to `qmp_send'
aarch64-linux-ld: drivers/remoteproc/qcom_q6v5.o: in function `qcom_q6v5_deinit':
(.text+0x2e4): undefined reference to `qmp_put'
aarch64-linux-ld: drivers/remoteproc/qcom_q6v5.o: in function `qcom_q6v5_init':
(.text+0x778): undefined reference to `qmp_get'
aarch64-linux-ld: (.text+0x7d8): undefined reference to `qmp_put'

Fixes: c1fe10d238c0 ("remoteproc: qcom: q6v5: Use qmp_send to update co-processor load state")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: linux-remoteproc@vger.kernel.org
Cc: Sibi Sankar <sibis@codeaurora.org>
Cc: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220115011338.2973-1-rdunlap@infradead.org

rpmsg: char: Fix race between the release of rpmsg_eptdev and cdev

struct rpmsg_eptdev contains a struct cdev. The current code frees
the rpmsg_eptdev struct in rpmsg_eptdev_destroy(), but the cdev is
a managed object, therefore its release is not predictable and the
rpmsg_eptdev could be freed before the cdev is entirely released.

The cdev_device_add/del() API was created to address this issue
(see commit '233ed09d7fda ("chardev: add helper function to register
char devs with a struct device")'), use it instead of cdev add/del().

Fixes: c0cdc19f84a4 ("rpmsg: Driver for user space endpoint interface")
Suggested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220110104706.v6.2.Idde68b05b88d4a2e6e54766c653f3a6d9e419ce6@changeid

rpmsg: char: Fix race between the release of rpmsg_ctrldev and cdev

struct rpmsg_ctrldev contains a struct cdev. The current code frees
the rpmsg_ctrldev struct in rpmsg_ctrldev_release_device(), but the
cdev is a managed object, therefore its release is not predictable
and the rpmsg_ctrldev could be freed before the cdev is entirely
released, as in the backtrace below.

[   93.625603] ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x7c
[   93.636115] WARNING: CPU: 0 PID: 12 at lib/debugobjects.c:488 debug_print_object+0x13c/0x1b0
[   93.644799] Modules linked in: veth xt_cgroup xt_MASQUERADE rfcomm algif_hash algif_skcipher af_alg uinput ip6table_nat fuse uvcvideo videobuf2_vmalloc venus_enc venus_dec videobuf2_dma_contig hci_uart btandroid btqca snd_soc_rt5682_i2c bluetooth qcom_spmi_temp_alarm snd_soc_rt5682v
[   93.715175] CPU: 0 PID: 12 Comm: kworker/0:1 Tainted: G    B             5.4.163-lockdep #26
[   93.723855] Hardware name: Google Lazor (rev3 - 8) with LTE (DT)
[   93.730055] Workqueue: events kobject_delayed_cleanup
[   93.735271] pstate: 60c00009 (nZCv daif +PAN +UAO)
[   93.740216] pc : debug_print_object+0x13c/0x1b0
[   93.744890] lr : debug_print_object+0x13c/0x1b0
[   93.749555] sp : ffffffacf5bc7940
[   93.752978] x29: ffffffacf5bc7940 x28: dfffffd000000000
[   93.758448] x27: ffffffacdb11a800 x26: dfffffd000000000
[   93.763916] x25: ffffffd0734f856c x24: dfffffd000000000
[   93.769389] x23: 0000000000000000 x22: ffffffd0733c35b0
[   93.774860] x21: ffffffd0751994a0 x20: ffffffd075ec27c0
[   93.780338] x19: ffffffd075199100 x18: 00000000000276e0
[   93.785814] x17: 0000000000000000 x16: dfffffd000000000
[   93.791291] x15: ffffffffffffffff x14: 6e6968207473696c
[   93.796768] x13: 0000000000000000 x12: ffffffd075e2b000
[   93.802244] x11: 0000000000000001 x10: 0000000000000000
[   93.807723] x9 : d13400dff1921900 x8 : d13400dff1921900
[   93.813200] x7 : 0000000000000000 x6 : 0000000000000000
[   93.818676] x5 : 0000000000000080 x4 : 0000000000000000
[   93.824152] x3 : ffffffd0732a0fa4 x2 : 0000000000000001
[   93.829628] x1 : ffffffacf5bc7580 x0 : 0000000000000061
[   93.835104] Call trace:
[   93.837644]  debug_print_object+0x13c/0x1b0
[   93.841963]  __debug_check_no_obj_freed+0x25c/0x3c0
[   93.846987]  debug_check_no_obj_freed+0x18/0x20
[   93.851669]  slab_free_freelist_hook+0xbc/0x1e4
[   93.856346]  kfree+0xfc/0x2f4
[   93.859416]  rpmsg_ctrldev_release_device+0x78/0xb8
[   93.864445]  device_release+0x84/0x168
[   93.868310]  kobject_cleanup+0x12c/0x298
[   93.872356]  kobject_delayed_cleanup+0x10/0x18
[   93.876948]  process_one_work+0x578/0x92c
[   93.881086]  worker_thread+0x804/0xcf8
[   93.884963]  kthread+0x2a8/0x314
[   93.888303]  ret_from_fork+0x10/0x18

The cdev_device_add/del() API was created to address this issue (see
commit '233ed09d7fda ("chardev: add helper function to register char
devs with a struct device")'), use it instead of cdev add/del().

Fixes: c0cdc19f84a4 ("rpmsg: Driver for user space endpoint interface")
Signed-off-by: Sujit Kautkar <sujitka@chromium.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220110104706.v6.1.Iaac908f3e3149a89190ce006ba166e2d3fd247a3@changeid

Merge branch 'linux-next' of git://git./linux/kernel/git/rafael/linux-pm.git

Merge branch 'docs-next' of git://git.lwn.net/linux.git

Merge branch 'i2c/for-next' of git://git./linux/kernel/git/wsa/linux.git

Merge branch 'for-next' of git://git./linux/kernel/git/hid/hid.git

Merge branch 'for-next' of git://git./linux/kernel/git/printk/linux.git

Merge branch 'for-next' of git://git./linux/kernel/git/viro/vfs.git

Merge branch 'locks-next' of git://git./linux/kernel/git/jlayton/linux.git

Merge branch 'for-next' of git://git./linux/kernel/git/dlemoal/zonefs.git

Merge branch 'for-next' of git://git./fs/xfs/xfs-linux.git

# Conflicts:
# fs/xfs/xfs_ioctl.c

scripts/dtc: dtx_diff: remove broken example from help text

dtx_diff suggests to use <(...) syntax to pipe two inputs into it, but
this has never worked: The /proc/self/fds/... paths passed by the shell
will fail the `[ -f "${dtx}" ] && [ -r "${dtx}" ]` check in compile_to_dts,
but even with this check removed, the function cannot work: hexdump will
eat up the DTB magic, making the subsequent dtc call fail, as a pipe
cannot be rewound.

Simply remove this broken example, as there is already an alternative one
that works fine.

Fixes: 10eadc253ddf ("dtc: create tool to diff device trees")
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220113081918.10387-1-matthias.schiffer@ew.tq-group.com

dt-bindings: trivial-devices: fix double spaces in comments

Cleanup double spaces in some of the comments.

Signed-off-by: Stanislav Jakubek <stano.jakubek@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/13b3f66efd3b20f1d9bbb9eff1eca00757ac5367.1642080090.git.stano.jakubek@gmail.com

dt-bindings: trivial-devices: fix swapped comments

sparkfun,qwiic-joystick and st,24c256 had their comments incorrectly
swapped. Swap them to make them correct.

Signed-off-by: Stanislav Jakubek <stano.jakubek@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/7dc6ddb0b042cd243b2875e9aea81cad541d1c6b.1642080090.git.stano.jakubek@gmail.com

dt-bindings: vendor-prefixes: add Wingtech

The vendor prefix for Wingtech [1] is used in device tree [2], but was
not documented so far. Add it to the schema to document it.

[1] http://www.wingtech.com/en
[2] arch/arm64/boot/dts/qcom/msm8916-wingtech-wt88047.dts

Signed-off-by: Stanislav Jakubek <stano.jakubek@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220113103110.GA4488@standask-GA-A55M-S2HP

dt-bindings: vendor-prefixes: add Thundercomm

The vendor prefix for Thundercomm [1] is used in device tree [2], but
was not documented so far. Add it to the schema to document it.

[1] https://www.thundercomm.com/
[2] arch/arm64/boot/dts/qcom/sdm845-db845c.dts

Signed-off-by: Stanislav Jakubek <stano.jakubek@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220113103036.GA4456@standask-GA-A55M-S2HP

dt-bindings: vendor-prefixes: add Huawei

The vendor prefix for Huawei [1] is used in device trees [2][3], but was
not documented so far. Add it to the schema to document it.

[1] https://www.huawei.com/en/
[2] arch/arm64/boot/dts/qcom/msm8916-huawei-g7.dts
[3] arch/arm64/boot/dts/qcom/msm8994-angler-rev-101.dts

Signed-off-by: Stanislav Jakubek <stano.jakubek@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220113103005.GA4421@standask-GA-A55M-S2HP

dt-bindings: vendor-prefixes: add F(x)tec

The vendor prefix for F(x)tec [1] is used in device tree [2], but was
not documented so far. Add it to the schema to document it.

[1] https://www.fxtec.com/
[2] arch/arm64/boot/dts/qcom/msm8998-fxtec-pro1.dts

Signed-off-by: Stanislav Jakubek <stano.jakubek@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220113102926.GA4388@standask-GA-A55M-S2HP

dt-bindings: vendor-prefixes: add 8devices

The vendor prefix for 8devices [1] is used in device tree [2], but was
not documented so far. Add it to the schema to document it.

[1] https://www.8devices.com/
[2] arch/arm/boot/dts/qcom-ipq4018-jalapeno.dts

Signed-off-by: Stanislav Jakubek <stano.jakubek@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220113102842.GA4357@standask-GA-A55M-S2HP

dt-bindings: power: reset: gpio-restart: Correct default priority

Commit bcd56fe1aa97 ("power: reset: gpio-restart: increase priority
slightly") changed the default restart priority 129, but did not update
the documentation. Correct this, so the driver and documentation have
the same default value.

Signed-off-by: Sander Vanheule <sander@svanheule.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220110214456.67087-1-sander@svanheule.net

Merge branch 'overlayfs-next' of git://git./linux/kernel/git/mszeredi/vfs.git

Merge branch 'for-next' of git://git./linux/kernel/git/hubcap/linux

Merge branch 'master' of https://github.com/Paragon-Software-Group/linux-ntfs3.git

Merge branch 'linux-next' of git://git.linux-nfs.org/projects/anna/linux-nfs.git

Merge branch 'ksmbd-for-next' of https://github.com/smfrench/smb3-kernel.git

Merge branch 'dev' of git://git./linux/kernel/git/jaegeuk/f2fs.git

Merge branch 'for_next' of git://git./linux/kernel/git/jack/linux-fs.git

Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6.git

Merge branch 'master' of git://github.com/ceph/ceph-client.git

# Conflicts:
# include/linux/ceph/libceph.h
# net/ceph/ceph_common.c

Merge branch 'for-next' of git://git./linux/kernel/git/kdave/linux.git

Merge branch 'fscache-next' of git://git./linux/kernel/git/dhowells/linux-fs.git

Merge branch 'for-next' of git://git./linux/kernel/git/brauner/linux.git

Merge branch 'xtensa-for-next' of git://github.com/jcmvbkbc/linux-xtensa.git

Merge branch 'for-next' of git://git./linux/kernel/git/s390/linux.git

Merge branch 'for-next' of git://git./linux/kernel/git/riscv/linux.git

# Conflicts:
# arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts
# arch/riscv/include/asm/sbi.h

Merge branch 'for-next' of git://git./linux/kernel/git/deller/parisc-linux.git

Merge branch 'next' of git://git./linux/kernel/git/greentime/linux.git

# Conflicts:
# arch/nds32/Kbuild
# arch/nds32/Kconfig

Merge branch 'next' of git://git.monstr.eu/linux-2.6-microblaze.git

Merge branch 'h8300-next' of git://git.sourceforge.jp/gitroot/uclinux-h8/linux.git

Merge branch 'clk-next' of git://git./linux/kernel/git/clk/linux.git

Merge branch 'for-next' of git://github.com/Xilinx/linux-xlnx.git

Merge branch 'ti-next' of git://git./linux/kernel/git/ti/linux.git

Merge branch 'for-next' of git://git./linux/kernel/git/tegra/linux.git

Merge branch 'next' of https://git.linaro.org/people/jens.wiklander/linux-tee.git

Merge branch 'sunxi/for-next' of git://git./linux/kernel/git/sunxi/linux.git

Merge branch 'for-linux-next' of git://git./linux/kernel/git/sudeep.holla/linux.git

Merge branch 'for-next' of git://git./linux/kernel/git/krzk/linux.git

Merge branch 'for-next' of git://git./linux/kernel/git/mmind/linux-rockchip.git

Merge branch 'next' of git://git./linux/kernel/git/geert/renesas-devel.git

Merge branch 'for-next' of git://git./linux/kernel/git/nsaenz/linux-rpi.git

Merge branch 'for-next' of git://git./linux/kernel/git/qcom/linux.git

# Conflicts:
# arch/arm/configs/multi_v7_defconfig

Merge branch 'for-next' of git://git./linux/kernel/git/tmlind/linux-omap.git

Merge branch 'for-next' of git://git./linux/kernel/git/gclement/mvebu.git

Merge branch 'for-next' of git://git./linux/kernel/git/matthias.bgg/linux.git

Merge branch 'next' of git://git./linux/kernel/git/ssantosh/linux-keystone.git

Merge branch 'for-next' of git://git./linux/kernel/git/shawnguo/linux.git