watchdog: clarify that stop() is optional

The commit d0684c8a9354 ("watchdog: Make stop function optional")
made stop function not mandatory, but the comments
and the doc weren't reflected. Fix it to clarify.

Signed-off-by: Bumsik Kim <k.bumsik@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200403031507.63487-1-k.bumsik@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

doc:it_IT: translation of documents in process/

Translations for the following documents in process/:
    - email-clients
    - management-style

Signed-off-by: Alessia Mantegazza <amantegazza@vaga.pv.it>
Signed-off-by: Federico Vaga <federico.vaga@vaga.pv.it>
Link: https://lore.kernel.org/r/20200413163457.52669-1-federico.vaga@vaga.pv.it
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: admin-guide: Clarify sentences

Changes to make the text more formal and organized. The reasons are now cited and described at the same time.
Minor grammatical problems have also been fixed.

Signed-off-by: Cristian Souza <cristianmsbr@gmail.com>
Link: https://lore.kernel.org/r/20200411010201.GA22706@darkstar
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: ioctl-number.rst: add habanalabs driver IOCTL

Habanalabs driver in misc exposes several IOCTLs to userspace. Document the
letter and IOCTLs number range in ioctl-number.rst.

Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20200418174132.10597-1-oded.gabbay@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

dma-buf: Couple of documentation typo fixes

Fix a couple of typos: "as" -> "has" and "int" -> "in".

Signed-off-by: Gal Pressman <galpress@amazon.com>
Link: https://lore.kernel.org/r/20200420074115.23931-1-galpress@amazon.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: sysctl/kernel: document BPF entries

Based on the implementation in kernel/bpf/syscall.c,
kernel/bpf/trampoline.c, include/linux/filter.h, and the documentation
in bpftool-prog.rst.

Signed-off-by: Stephen Kitt <steve@sk2.org>
Link: https://lore.kernel.org/r/20200315122648.20558-1-steve@sk2.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Merge branch 'mauro' into docs-next

Mauro sez:

Patches 1 to 5 contain changes to the documentation toolset:

- The first 3 patches help to reduce a lot the number of reported
  kernel-doc issues, by making the tool more smart.

- Patches 4 and 5 are meant to partially address the PDF
  build, with now requires Sphinx version 2.4 or upper.

The remaining patches fix broken references detected by
this tool:

        ./scripts/documentation-file-ref-check

and address other random errors due to tags being mis-interpreted
or mis-used.

They are independent each other, but some may depend on
the kernel-doc improvements.

lib: bitmap.c: get rid of some doc warnings

There are two ascii art drawings there. Use a block markup tag there
in order to get rid of those warnings:

./lib/bitmap.c:189: WARNING: Unexpected indentation.
./lib/bitmap.c:190: WARNING: Block quote ends without a blank line; unexpected unindent.
./lib/bitmap.c:190: WARNING: Unexpected indentation.
./lib/bitmap.c:191: WARNING: Line block ends without a blank line.

It should be noticed that there's actually a syntax violation
right now, as something like:

/**
 ...
 @src:

will be handled as a definition for @src parameter, and not as
part of a diagram. So, we need to add something before it, in
order for this to be processed the way it should.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/1e2568fdfa838c1a0d8cc2a1d70dd4b6de99bfb1.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

futex: get rid of a kernel-docs build warning

Adjust whitespaces and blank lines in order to get rid of this:

./kernel/futex.c:491: WARNING: Definition list ends without a blank line; unexpected unindent.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/57788af7889161483e0c97f91c079cfb3986c4b3.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

fs: inode.c: get rid of docs warnings

Use *foo makes the toolchain to think that this is an emphasis, causing
those warnings:

./fs/inode.c:1609: WARNING: Inline emphasis start-string without end-string.
./fs/inode.c:1609: WARNING: Inline emphasis start-string without end-string.
./fs/inode.c:1615: WARNING: Inline emphasis start-string without end-string.

So, use, instead, ``*foo``, in order to mark it as a literal block.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/e8da46a0e57f2af6d63a0c53665495075698e28a.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

firewire: firewire-cdev.hL get rid of a docs warning

This warning:

./include/uapi/linux/firewire-cdev.h:312: WARNING: Inline literal start-string without end-string.

is because %FOO doesn't work if there's a parenthesis at the
string (as a parenthesis may indicate a function). So, mark
the literal block using the alternate ``FOO`` syntax.

Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/9b2501a41eba27ccdd4603cac2353c0efba7a90a.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

ata: libata-core: fix a doc warning

The docs toolchain doesn't recognise this pattern:

@link->[hw_]sata_spd_limit

As it can't really process it. So, instead, let's mark it with
a literal block markup:

``link->[hw_]sata_spd_limit``

in order to get rid of the following warning:

./drivers/ata/libata-core.c:5974: WARNING: Unknown target name: "hw".

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/9a21444df75c46095c4b1839d2061d19c9addcff.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: dt: rockchip,dwc3.txt: fix a pointer to a renamed file

phy-rockchip-inno-usb2.txt was converted to yaml.

Fix the corresponding reference.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/287bd271f5c542e9d12a132a6b6a17672c9fd67c.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: Makefile: place final pdf docs on a separate dir

The Sphinx build system for PDF is too complex and generate
lots of ancillary files, including one PDF file for each
image.

So, at the end, the main latex dir has 156 pdf files, instead
of the 71 ones that would match each generated book. That's
confusing and it makes harder to identify when something didn't
work.

So, instead, let's move the final PDF output(s) to a separate
dir. This way, the latex/ dir will have the temporary and the
final *.tex files, while the final pdf files that built ok
will be under the pdf/ directory.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/832752cbc9678a6e8d3d634bc3356d655d44684f.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: i2c: rename i2c.svg to i2c_bus.svg

When generating the PDF output, the Documentation/i2c dir
will generate an i2c.pdf. The same happens with i2c.svg:
it will also produce a file with the same name, at the same dir.

This causes errors when building the PDF output. So, rename the
image to i2c_bus.svg.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Link: https://lore.kernel.org/r/ecf3d51909ce46b3e84a1df4b36f07d76989e5da.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: powerpc: cxl.rst: mark two section titles as such

The User API chapter contains two sub-chapters. Mark them as
such.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Link: https://lore.kernel.org/r/190d67397cd63e419de8d85b92e8018d48e8c345.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: dt: fix a broken reference for a file converted to json

Changeset 32ced09d7903 ("dt-bindings: serial: Convert slave-device bindings to json-schema")
moved a binding to json and updated the links.

Yet, one link was not changed, due to a merge conflict.

Update this one too.

Fixes: 32ced09d7903 ("dt-bindings: serial: Convert slave-device bindings to json-schema")
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/9b1603e254d39c9607bfedefeedaafd2c44aeb19.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: dt: qcom,dwc3.txt: fix cross-reference for a converted file

The qcom-qusb2-phy.txt file was converted and renamed to yaml.
Update cross-reference accordingly.

Fixes: 8ce65d8d38df ("dt-bindings: phy: qcom,qusb2: Convert QUSB2 phy bindings to yaml")
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/a055c564f2a79aa748064329d938db8b3c8edd58.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: vm: index.rst: add an orphan doc to the building system

The new free_page_reporting.rst file is not listed at the index.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/146432ae6965a2bb62c929a6b62f9d4010986622.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: mm: userfaultfd.rst: use a cross-reference for a section

Instead of using "foo", let's use `foo`_, with is a ReST way of
saying that foo is a section of the document. With that, after
building the docs, an hyperlink is generated.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/f46b45f1aaec233217f2e0b0438bbd8cc16fe17b.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: mm: userfaultfd.rst: use ``foo`` for literals

Several parts of this document define literals: ioctl names,
function calls, directory patches, etc. Mark those as literal
blocks, in order to improve its readability (both at text mode
and after parsed by Sphinx.

This fixes those two warnings:

Documentation/admin-guide/mm/userfaultfd.rst:139: WARNING: Inline emphasis start-string without end-string.
Documentation/admin-guide/mm/userfaultfd.rst:139: WARNING: Inline emphasis start-string without end-string.

produced during documentation build.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/2ae061761baf8fe00cdf8a7e6dae293756849a05.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: drivers: fix some warnings at base/platform.c when building docs

Currrently, two warnings are generated when building docs:

./drivers/base/platform.c:136: WARNING: Unexpected indentation.
./drivers/base/platform.c:214: WARNING: Unexpected indentation.

As examples are code blocks, they should use "::" markup. However,

Example::

Is currently interpreted as a new section.

While we could fix kernel-doc to accept such new syntax, it is
easier to just replace it with:

For Example::

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/564273815a76136fb5e453969b1012a786d99e28.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: spi: spi.h: fix a doc building warning

We need to add a blank line to avoid this warning:

./include/linux/spi/spi.h:401: WARNING: Unexpected indentation.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/1c701b3ac903dc0bc304dca958fbdee53bd38dc3.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: ras: don't need to repeat twice the same thing

We don't need to say twice "for the first time" at the same
paragraph.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/f76dcae96de8b1bb8ee37a79781c111c825e26d6.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: ras: get rid of some warnings

Sphinx produce some warnings due to a bad table format:

    Documentation/admin-guide/ras.rst:358: WARNING: Definition list ends without a blank line; unexpected unindent.
    Documentation/admin-guide/ras.rst:358: WARNING: Definition list ends without a blank line; unexpected unindent.
    Documentation/admin-guide/ras.rst:363: WARNING: Definition list ends without a blank line; unexpected unindent.
    Documentation/admin-guide/ras.rst:363: WARNING: Definition list ends without a blank line; unexpected unindent.

Rearrange the things there in order to supress the warnings
while being precise at the Sphinx output about how ranks are
mapped into csrows.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/9e1bb44d6dbedb5b6f049d081b47da1f9620de16.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: pci: boot-interrupts.rst: improve html output

There are some warnings with this file:

    /Documentation/PCI/boot-interrupts.rst:42: WARNING: Unexpected indentation.
    /Documentation/PCI/boot-interrupts.rst:52: WARNING: Block quote ends without a blank line; unexpected unindent.
    /Documentation/PCI/boot-interrupts.rst:92: WARNING: Unexpected indentation.
    /Documentation/PCI/boot-interrupts.rst:98: WARNING: Unexpected indentation.
    /Documentation/PCI/boot-interrupts.rst:136: WARNING: Unexpected indentation.

It turns that this file conversion to ReST could be improved,
in order to remove the warnings and provide a better output.

So, fix the warnings by adjusting blank lines, add a table and
some list markups. Also, mark endnodes as such.

Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/a6a9eb16eede10731bcce69a600ab12d92e6ba47.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: arm64: booting.rst: get rid of some warnings

Get rid of those warnings:

    Documentation/arm64/booting.rst:253: WARNING: Unexpected indentation.
    Documentation/arm64/booting.rst:259: WARNING: Block quote ends without a blank line; unexpected unindent.

By adding an extra blank lines where needed.

While here, use list markups on some places, as otherwise Sphinx
will consider the next lines as continuation of the privious ones.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/121b267be0a102fde73498c31792e5a9309013cc.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: amu: supress some Sphinx warnings

Add extra blank lines on some places, in order to avoid those
warnings when building the docs:

    Documentation/arm64/amu.rst:26: WARNING: Unexpected indentation.
    Documentation/arm64/amu.rst:60: WARNING: Unexpected indentation.
    Documentation/arm64/amu.rst:81: WARNING: Unexpected indentation.
    Documentation/arm64/amu.rst:108: WARNING: Unexpected indentation.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/ab0881638fc41ed790b3307a8e022ec84b7cce7e.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: filesystems: fix renamed references

Some filesystem references got broken by a previous patch
series I submitted. Address those.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: David Sterba <dsterba@suse.com> # fs/affs/Kconfig
Link: https://lore.kernel.org/r/57318c53008dbda7f6f4a5a9e5787f4d37e8565a.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: fix broken references for ReST files that moved around

Some broken references happened due to shifting files around
and ReST renames. Those can't be auto-fixed by the script,
so let's fix them manually.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Link: https://lore.kernel.org/r/64773a12b4410aaf3e3be89e3ec7e34de2484eea.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: fix broken references to text files

Several references got broken due to txt to ReST conversion.

Several of them can be automatically fixed with:

scripts/documentation-file-ref-check --fix

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> # hwtracing/coresight/Kconfig
Reviewed-by: Paul E. McKenney <paulmck@kernel.org> # memory-barrier.txt
Acked-by: Alex Shi <alex.shi@linux.alibaba.com> # translations/zh_CN
Acked-by: Federico Vaga <federico.vaga@vaga.pv.it> # translations/it_IT
Acked-by: Marc Zyngier <maz@kernel.org> # kvm/arm64
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/6f919ddb83a33b5f2a63b6b5f0575737bb2b36aa.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: dt: fix broken reference to phy-cadence-torrent.yaml

This file was removed, and another file was added instead of
it, on two separate commits.

Splitting a single logical change (doc conversion) on two
patches is a bad thing, as it makes harder to discover what
crap happened.

Anyway, this patch fixes the broken reference, making it
pointing to the new location of the file.

Fixes: 922003733d42 ("dt-bindings: phy: Remove Cadence MHDP PHY dt binding")
Fixes: c6d8eef38b7f ("dt-bindings: phy: Add Cadence MHDP PHY bindings in YAML format.")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/3f1cf6d74e392f3ee9f894d82cb7ee29d04c1b6d.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

MAINTAINERS: dt: fix pointers for ARM Integrator, Versatile and RealView

There's a conversion from a plain text binding file into 4 yaml ones.
The old file got removed, causing this new warning:

Warning: MAINTAINERS references a file that doesn't exist: Documentation/devicetree/bindings/arm/arm-boards

Address it by replacing the old reference by the new ones

Fixes: 2d483550b6d2 ("dt-bindings: arm: Drop the non-YAML bindings")
Fixes: 33fbfb3eaf4e ("dt-bindings: arm: Add Integrator YAML schema")
Fixes: 4b900070d50d ("dt-bindings: arm: Add Versatile YAML schema")
Fixes: 7db625b9fa75 ("dt-bindings: arm: Add RealView YAML schema")
Fixes: 4fb00d9066c1 ("dt-bindings: arm: Add Versatile Express and Juno YAML schema")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/eae3440fb70c1b1666973e34fd3fd6b8ab4a3bc7.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

MAINTAINERS: dt: update display/allwinner file entry

Changeset f5a98bfe7b37 ("dt-bindings: display: Convert Allwinner display pipeline to schemas")
split Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt
into several files. Yet, it kept the old place at MAINTAINERS.

Update it to point to the new place.

Fixes: f5a98bfe7b37 ("dt-bindings: display: Convert Allwinner display pipeline to schemas")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/1be758765272ba4c2acbc3904bdf71c863a90186.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: LaTeX/PDF: drop list of documents

The building system can auto-generate a list of documents since
commit: 9d42afbe6bd4 ("docs: pdf: add all Documentation/*/index.rst to PDF output").

The added logic there allows keeping the existing list, but
there's not real reason to keep it. Now, the media document
has gone (it was split into tree).

So, it sounds about time to get rid of the manual entries,
and let the script to generate it automatically instead.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/9345dba7164497dbf28578f6ec271e479379610c.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: update recommended Sphinx version to 2.4.4

There are some docs that have nested tables. While this was
always part of the spec, only Sphinx version 2.4.x can
translate it to LaTeX.

In other words, if someone is using a Sphinx version < 2.4,
the LaTeX and PDF output won't work for some of the docs.

So, it seems that it is time to raise the bar again
for the recommented version.

The Sphinx check script is already smart enough to keep
working, with older versions, warning the users that
an upgrade is recommended (and explaining how):

Sphinx version 1.7.9
Warning: It is recommended at least Sphinx version 2.4.4.
Detected OS: Fedora release 31 (Thirty One).

To upgrade Sphinx, use:

/usr/bin/virtualenv sphinx_2.4.4
. sphinx_2.4.4/bin/activate
pip install -r ./Documentation/sphinx/requirements.txt

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/498f701c618f7d0cf5f0a37e5889ee926f7c8bf4.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: accept blank lines on parameter description

Sphinx is very pedantic with respect to blank lines. Sometimes,
in order to make it to properly handle something, we need to
add a blank line. However, currently, any blank line inside a
kernel-doc comment like:

/*
 * @foo: bar
         *
 *       foobar
 *
 * some description

will be considered as if "foobar" was part of the description.

This patch changes kernel-doc behavior. After it, foobar will
be considered as part of the parameter text. The description
will only be considered as such if it starts with:

zero spaces after asterisk:

*foo

one space after asterisk:
* foo

or have a explicit Description section:

*   Description:

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/c07d2862792d75a2691d69c9eceb7b89a0164cc0.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: accept negation like !@var

On a few places, it sometimes need to indicate a negation of a
parameter, like:

!@fshared

This pattern happens, for example, at:

kernel/futex.c

and it is perfectly valid. However, kernel-doc currently
transforms it into:

!**fshared**

This won't do what it would be expected.

Fortunately, fixing the script is a simple matter of storing
the "!" before "@" and adding it after the bold markup, like:

**!fshared**

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/0314b47f8c3e1f9db00d5375a73dc3cddd8a21f2.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: kernel-doc: proper handle @foo->bar()

The pattern @foo->bar() is valid, as it can be used by a
function pointer inside a struct passed as a parameter.

Right now, it causes a warning:

./drivers/firewire/core-transaction.c:606: WARNING: Inline strong start-string without end-string.

In this specific case, the kernel-doc markup is:

/**
 * fw_core_remove_address_handler() - unregister an address handler
 * @handler: callback
 *
 * To be called in process context.
 *
 * When fw_core_remove_address_handler() returns, @handler->callback() is
 * guaranteed to not run on any CPU anymore.
 */

With seems valid on my eyes. So, instead of trying to hack
the kernel-doc markup, let's teach it about how to handle
such things. This should likely remove lots of other similar
warnings as well.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/48b46426d7bf6ff7529f20e5718fbf4e9758e62c.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: sphinx-pre-install: add support for python -m venv

Since python 3.3, the recommended way to setup a virtual env is
via "python -m venv".

Set this as a default, if python version is compatible with
such feature.

While here, add more comments to it, as the script is
getting more complex. So, better to add more things, to avoid
accidentally breaking it while improving it.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/252cc849c79527ad496247e4c481961478adf41c.1586883286.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: sphinx-pre-install: add support for OpenMandriva

It seems that Mageia and OpenMandriva will reunite on a single
distribution. In any case, both came from Mandriva. So, it is
close enough to use the same logic.

So, add support for it.

Tested with OpenMandriva 4.1 and with Mageia 7.1.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/692809729c6818a0b0f75513da15970c53d5565c.1586883286.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: sphinx-pre-install: address some issues with Gentoo

There are some small misdetections with Gentoo. While they
don't cause too much trouble, it keeps recomending to
install things that are already there.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/7f631edce102b02ccbdbfb18be1376a86b41373d.1586883286.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: sphinx-pre-install: fix a dependency hint with Ubuntu 16.04

Avoid the scripts to keep asking to install fonts-noto-cjk
on Ubuntu 16.04.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/912b664a8ca54e8c5c5767c3fe9171973eeddd6b.1586883286.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: sphinx-pre-install: improve openSuse Tumbleweed check

Currently, with openSUSE Tumbleweed 20200303, it keeps
recommending this forever:

sudo zypper install --no-recommends rsvg-view

This dependency will never be fulfilled there, as the package
now is named as on other distros: rsvg-convert.

So, improve the detection to avoid such issue.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/c3774f72ac36c5e5b5f446ae5db5b795d1f274f4.1586883286.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: sphinx-pre-install: improve distro detection check

The Arch-linux detection is hit by catting /etc/issue, whose
contents is (nowadays):

Arch Linux \r (\l)

It sounds a little ackward to print such string, so,
instead, let's use the /etc/os-release file, with exists
on lots of distributions and should provide a more reliable
result.

We'll keep the old tests before it, in order to avoid possible
regressions with the other distros, although the new way should
probably work on all the currently supported distributions.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/472924557afdf2b5492ae2a48c5ecfae216d54e2.1586883286.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts: documentation-file-ref-check: Add line break before exit

If execute ./scripts/documentation-file-ref-check in a directory which is
not a git tree, it will exit without a line break, fix it.

Without this patch:

[loongson@localhost linux-5.7-rc1]$ ./scripts/documentation-file-ref-check
Warning: can't check if file exists, as this is not a git tree[loongson@localhost linux-5.7-rc1]$

With this patch:

[loongson@localhost linux-5.7-rc1]$ ./scripts/documentation-file-ref-check
Warning: can't check if file exists, as this is not a git tree
[loongson@localhost linux-5.7-rc1]$

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/1586857308-2040-1-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc: Add missing close-paren in c:function directives

When kernel-doc generates a 'c:function' directive for a function
one of whose arguments is a function pointer, it fails to print
the close-paren after the argument list of the function pointer
argument. For instance:

 long work_on_cpu(int cpu, long (*fn) (void *, void * arg)

in driver-api/basics.html is missing a ')' separating the
"void *" of the 'fn' arguments from the ", void * arg" which
is an argument to work_on_cpu().

Add the missing close-paren, so that we render the prototype
correctly:

 long work_on_cpu(int cpu, long (*fn)(void *), void * arg)

(Note that Sphinx stops rendering a space between the '(fn*)' and the
'(void *)' once it gets something that's syntactically valid.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Link: https://lore.kernel.org/r/20200414143743.32677-1-peter.maydell@linaro.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: admin-guide: merge sections for the kernel.modprobe sysctl

Documentation for the kernel.modprobe sysctl was added both by
commit 0317c5371e6a ("docs: merge debugging-modules.txt into
sysctl/kernel.rst") and by commit 6e7158250625 ("docs: admin-guide:
document the kernel.modprobe sysctl"), resulting in the same sysctl
being documented in two places.  Merge these into one place.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Stephen Kitt <steve@sk2.org>
Link: https://lore.kernel.org/r/20200414172430.230293-1-ebiggers@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

docs: timekeeping: Use correct prototype for deprecated functions

Use the correct prototypes for do_gettimeofday(), getnstimeofday() and
getnstimeofday64(). All of these returned void and passed the return
value by reference. This should make the documentation of their
deprecation and replacements easier to search for.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200414221222.23996-1-chris.packham@alliedtelesis.co.nz
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Linux 5.7-rc1

MAINTAINERS: sort field names for all entries

This sorts the actual field names too, potentially causing even more
chaos and confusion at merge time if you have edited the MAINTAINERS
file.  But the end result is a more consistent layout, and hopefully
it's a one-time pain minimized by doing this just before the -rc1
release.

This was entirely scripted:

  ./scripts/parse-maintainers.pl --input=MAINTAINERS --output=MAINTAINERS --order

Requested-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: sort entries by entry name

They are all supposed to be sorted, but people who add new entries don't
always know the alphabet.  Plus sometimes the entry names get edited,
and people don't then re-order the entry.

Let's see how painful this will be for merging purposes (the MAINTAINERS
file is often edited in various different trees), but Joe claims there's
relatively few patches in -next that touch this, and doing it just
before -rc1 is likely the best time.  Fingers crossed.

This was scripted with

  /scripts/parse-maintainers.pl --input=MAINTAINERS --output=MAINTAINERS

but then I also ended up manually upper-casing a few entry names that
stood out when looking at the end result.

Requested-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'x86-urgent-2020-04-12' of git://git./linux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner:
 "A set of three patches to fix the fallout of the newly added split
  lock detection feature.

  It addressed the case where a KVM guest triggers a split lock #AC and
  KVM reinjects it into the guest which is not prepared to handle it.

  Add proper sanity checks which prevent the unconditional injection
  into the guest and handles the #AC on the host side in the same way as
  user space detections are handled. Depending on the detection mode it
  either warns and disables detection for the task or kills the task if
  the mode is set to fatal"

* tag 'x86-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  KVM: VMX: Extend VMXs #AC interceptor to handle split lock #AC in guest
  KVM: x86: Emulate split-lock access as a write in emulator
  x86/split_lock: Provide handle_guest_split_lock()

Merge tag 'timers-urgent-2020-04-12' of git://git./linux/kernel/git/tip/tip

Pull time(keeping) updates from Thomas Gleixner:

 - Fix the time_for_children symlink in /proc/$PID/ so it properly
   reflects that it part of the 'time' namespace

 - Add the missing userns limit for the allowed number of time
   namespaces, which was half defined but the actual array member was
   not added. This went unnoticed as the array has an exessive empty
   member at the end but introduced a user visible regression as the
   output was corrupted.

 - Prevent further silent ucount corruption by adding a BUILD_BUG_ON()
   to catch half updated data.

* tag 'timers-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ucount: Make sure ucounts in /proc/sys/user don't regress again
  time/namespace: Add max_time_namespaces ucount
  time/namespace: Fix time_for_children symlink

Merge tag 'sched-urgent-2020-04-12' of git://git./linux/kernel/git/tip/tip

Pull scheduler fixes/updates from Thomas Gleixner:

 - Deduplicate the average computations in the scheduler core and the
   fair class code.

 - Fix a raise between runtime distribution and assignement which can
   cause exceeding the quota by up to 70%.

 - Prevent negative results in the imbalanace calculation

 - Remove a stale warning in the workqueue code which can be triggered
   since the call site was moved out of preempt disabled code. It's a
   false positive.

 - Deduplicate the print macros for procfs

 - Add the ucmap values to the SCHED_DEBUG procfs output for completness

* tag 'sched-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/debug: Add task uclamp values to SCHED_DEBUG procfs
  sched/debug: Factor out printing formats into common macros
  sched/debug: Remove redundant macro define
  sched/core: Remove unused rq::last_load_update_tick
  workqueue: Remove the warning in wq_worker_sleeping()
  sched/fair: Fix negative imbalance in imbalance calculation
  sched/fair: Fix race between runtime distribution and assignment
  sched/fair: Align rq->avg_idle and rq->avg_scan_cost

Merge tag 'perf-urgent-2020-04-12' of git://git./linux/kernel/git/tip/tip

Pull perf fixes from Thomas Gleixner:
 "Three fixes/updates for perf:

   - Fix the perf event cgroup tracking which tries to track the cgroup
     even for disabled events.

   - Add Ice Lake server support for uncore events

   - Disable pagefaults when retrieving the physical address in the
     sampling code"

* tag 'perf-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Disable page faults when getting phys address
  perf/x86/intel/uncore: Add Ice Lake server uncore support
  perf/cgroup: Correct indirection in perf_less_group_idx()
  perf/core: Fix event cgroup tracking

Merge tag 'locking-urgent-2020-04-12' of git://git./linux/kernel/git/tip/tip

Pull locking fixes from Thomas Gleixner:
 "Three small fixes/updates for the locking core code:

   - Plug a task struct reference leak in the percpu rswem
     implementation.

   - Document the refcount interaction with PID_MAX_LIMIT

   - Improve the 'invalid wait context' data dump in lockdep so it
     contains all information which is required to decode the problem"

* tag 'locking-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/lockdep: Improve 'invalid wait context' splat
  locking/refcount: Document interaction with PID_MAX_LIMIT
  locking/percpu-rwsem: Fix a task_struct refcount

Merge tag '5.7-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "Ten cifs/smb fixes:

   - five RDMA (smbdirect) related fixes

   - add experimental support for swap over SMB3 mounts

   - also a fix which improves performance of signed connections"

* tag '5.7-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: enable swap on SMB3 mounts
  smb3: change noisy error message to FYI
  smb3: smbdirect support can be configured by default
  cifs: smbd: Do not schedule work to send immediate packet on every receive
  cifs: smbd: Properly process errors on ib_post_send
  cifs: Allocate crypto structures on the fly for calculating signatures of incoming packets
  cifs: smbd: Update receive credits before sending and deal with credits roll back on failure before sending
  cifs: smbd: Check send queue size before posting a send
  cifs: smbd: Merge code to track pending packets
  cifs: ignore cached share root handle closing errors

Merge tag 'nfs-for-5.7-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client bugfix from Trond Myklebust:
 "Fix an RCU read lock leakage in pnfs_alloc_ds_commits_list()"

* tag 'nfs-for-5.7-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  pNFS: Fix RCU lock leakage

Merge tag 'nios2-v5.7-rc1' of git://git./linux/kernel/git/lftan/nios2

Pull nios2 updates from Ley Foon Tan:

 - Remove nios2-dev@lists.rocketboards.org from MAINTAINERS

 - remove 'resetvalue' property

 - rename 'altr,gpio-bank-width' -> 'altr,ngpio'

 - enable the common clk subsystem on Nios2

* tag 'nios2-v5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2:
  MAINTAINERS: Remove nios2-dev@lists.rocketboards.org
  arch: nios2: remove 'resetvalue' property
  arch: nios2: rename 'altr,gpio-bank-width' -> 'altr,ngpio'
  arch: nios2: Enable the common clk subsystem on Nios2

Merge tag 'dma-mapping-5.7-1' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - fix an integer truncation in dma_direct_get_required_mask
   (Kishon Vijay Abraham)

 - fix the display of dma mapping types (Grygorii Strashko)

* tag 'dma-mapping-5.7-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-debug: fix displaying of dma allocation type
  dma-direct: fix data truncation in dma_direct_get_required_mask()

Merge tag 'kbuild-v5.7-2' of git://git./linux/kernel/git/masahiroy/linux-kbuild

Pull more Kbuild updates from Masahiro Yamada:

 - raise minimum supported binutils version to 2.23

 - remove old CONFIG_AS_* macros that we know binutils >= 2.23 supports

 - move remaining CONFIG_AS_* tests to Kconfig from Makefile

 - enable -Wtautological-compare warnings to catch more issues

 - do not support GCC plugins for GCC <= 4.7

 - fix various breakages of 'make xconfig'

 - include the linker version used for linking the kernel into
   LINUX_COMPILER, which is used for the banner, and also exposed to
   /proc/version

 - link lib-y objects to vmlinux forcibly when CONFIG_MODULES=y, which
   allows us to remove the lib-ksyms.o workaround, and to solve the last
   known issue of the LLVM linker

 - add dummy tools in scripts/dummy-tools/ to enable all compiler tests
   in Kconfig, which will be useful for distro maintainers

 - support the single switch, LLVM=1 to use Clang and all LLVM utilities
   instead of GCC and Binutils.

 - support LLVM_IAS=1 to enable the integrated assembler, which is still
   experimental

* tag 'kbuild-v5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (36 commits)
  kbuild: fix comment about missing include guard detection
  kbuild: support LLVM=1 to switch the default tools to Clang/LLVM
  kbuild: replace AS=clang with LLVM_IAS=1
  kbuild: add dummy toolchains to enable all cc-option etc. in Kconfig
  kbuild: link lib-y objects to vmlinux forcibly when CONFIG_MODULES=y
  MIPS: fw: arc: add __weak to prom_meminit and prom_free_prom_memory
  kbuild: remove -I$(srctree)/tools/include from scripts/Makefile
  kbuild: do not pass $(KBUILD_CFLAGS) to scripts/mkcompile_h
  Documentation/llvm: fix the name of llvm-size
  kbuild: mkcompile_h: Include $LD version in /proc/version
  kconfig: qconf: Fix a few alignment issues
  kconfig: qconf: remove some old bogus TODOs
  kconfig: qconf: fix support for the split view mode
  kconfig: qconf: fix the content of the main widget
  kconfig: qconf: Change title for the item window
  kconfig: qconf: clean deprecated warnings
  gcc-plugins: drop support for GCC <= 4.7
  kbuild: Enable -Wtautological-compare
  x86: update AS_* macros to binutils >=2.23, supporting ADX and AVX2
  crypto: x86 - clean up poly1305-x86_64-cryptogams.S by 'make clean'
  ...

mailmap: Add Sedat Dilek (replacement for expired email address)

I do not longer work for credativ Germany.

Please, use my private email address instead.

This is for the case when people want to CC me on
patches sent from my old business email address.

Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

pNFS: Fix RCU lock leakage

Another brown paper bag moment. pnfs_alloc_ds_commits_list() is leaking
the RCU lock.

Fixes: a9901899b649 ("pNFS: Add infrastructure for cleaning up per-layout commit structures")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

KVM: VMX: Extend VMXs #AC interceptor to handle split lock #AC in guest

Two types of #AC can be generated in Intel CPUs:
 1. legacy alignment check #AC
 2. split lock #AC

Reflect #AC back into the guest if the guest has legacy alignment checks
enabled or if split lock detection is disabled.

If the #AC is not a legacy one and split lock detection is enabled, then
invoke handle_guest_split_lock() which will either warn and disable split
lock detection for this task or force SIGBUS on it.

[ tglx: Switch it to handle_guest_split_lock() and rename the misnamed
  helper function. ]

Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20200410115517.176308876@linutronix.de

KVM: x86: Emulate split-lock access as a write in emulator

Emulate split-lock accesses as writes if split lock detection is on
to avoid #AC during emulation, which will result in a panic(). This
should never occur for a well-behaved guest, but a malicious guest can
manipulate the TLB to trigger emulation of a locked instruction[1].

More discussion can be found at [2][3].

[1] https://lkml.kernel.org/r/8c5b11c9-58df-38e7-a514-dc12d687b198@redhat.com
[2] https://lkml.kernel.org/r/20200131200134.GD18946@linux.intel.com
[3] https://lkml.kernel.org/r/20200227001117.GX9940@linux.intel.com

Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20200410115517.084300242@linutronix.de

x86/split_lock: Provide handle_guest_split_lock()

Without at least minimal handling for split lock detection induced #AC,
VMX will just run into the same problem as the VMWare hypervisor, which
was reported by Kenneth.

It will inject the #AC blindly into the guest whether the guest is
prepared or not.

Provide a function for guest mode which acts depending on the host
SLD mode. If mode == sld_warn, treat it like user space, i.e. emit a
warning, disable SLD and mark the task accordingly. Otherwise force
SIGBUS.

 [ bp: Add a !CPU_SUP_INTEL stub for handle_guest_split_lock(). ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20200410115516.978037132@linutronix.de
Link: https://lkml.kernel.org/r/20200402123258.895628824@linutronix.de

kbuild: fix comment about missing include guard detection

The keyword here is 'twice' to explain the trick.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Merge branch 'akpm' (patches from Andrew)

Merge yet more updates from Andrew Morton:

 - Almost all of the rest of MM (memcg, slab-generic, slab, pagealloc,
   gup, hugetlb, pagemap, memremap)

 - Various other things (hfs, ocfs2, kmod, misc, seqfile)

* akpm: (34 commits)
  ipc/util.c: sysvipc_find_ipc() should increase position index
  kernel/gcov/fs.c: gcov_seq_next() should increase position index
  fs/seq_file.c: seq_read(): add info message about buggy .next functions
  drivers/dma/tegra20-apb-dma.c: fix platform_get_irq.cocci warnings
  change email address for Pali Rohár
  selftests: kmod: test disabling module autoloading
  selftests: kmod: fix handling test numbers above 9
  docs: admin-guide: document the kernel.modprobe sysctl
  fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once()
  kmod: make request_module() return an error when autoloading is disabled
  mm/memremap: set caching mode for PCI P2PDMA memory to WC
  mm/memory_hotplug: add pgprot_t to mhp_params
  powerpc/mm: thread pgprot_t through create_section_mapping()
  x86/mm: introduce __set_memory_prot()
  x86/mm: thread pgprot_t through init_memory_mapping()
  mm/memory_hotplug: rename mhp_restrictions to mhp_params
  mm/memory_hotplug: drop the flags field from struct mhp_restrictions
  mm/special: create generic fallbacks for pte_special() and pte_mkspecial()
  mm/vma: introduce VM_ACCESS_FLAGS
  mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS
  ...

Merge tag 'docs-5.7-2' of git://git.lwn.net/linux

Pull Documentation fixes from Jonathan Corbet:
 "A handful of late-arriving fixes for the documentation tree"

* tag 'docs-5.7-2' of git://git.lwn.net/linux:
  Documentation: android: binderfs: add 'stats' mount option
  Documentation: driver-api/usb/writing_usb_driver.rst Updates documentation links
  docs: driver-api: address duplicate label warning
  Documentation: sysrq: fix RST formatting
  docs: kernel-parameters.txt: Fix broken references
  docs: kernel-parameters.txt: Remove nompx
  docs: filesystems: fix typo in qnx6.rst

Merge tag 'for-linus-5.7-ofs1' of git://git./linux/kernel/git/hubcap/linux

Pull orangefs updates from Mike Marshall:
 "A fix and two cleanups.

  Fix:

   - Christoph Hellwig noticed that some logic I added to
     orangefs_file_read_iter introduced a race condition, so he sent a
     reversion patch. I had to modify his patch since reverting at this
     point broke Orangefs.

  Cleanups:

   - Christoph Hellwig noticed that we were doing some unnecessary work
     in orangefs_flush, so he sent in a patch that removed the un-needed
     code.

   - Al Viro told me he had trouble building Orangefs. Orangefs should
     be easy to build, even for Al :-).

     I looked back at the test server build notes in orangefs.txt, just
     in case that's where the trouble really is, and found a couple of
     typos and made a couple of clarifications"

* tag 'for-linus-5.7-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
  orangefs: clarify build steps for test server in orangefs.txt
  orangefs: don't mess with I_DIRTY_TIMES in orangefs_flush
  orangefs: get rid of knob code...

Merge tag 'xtensa-20200410' of git://github.com/jcmvbkbc/linux-xtensa

Pull xtensa updates from Max Filippov:

 - replace setup_irq() by request_irq()

 - cosmetic fixes in xtensa Kconfig and boot/Makefile

* tag 'xtensa-20200410' of git://github.com/jcmvbkbc/linux-xtensa:
  arch/xtensa: fix grammar in Kconfig help text
  xtensa: remove meaningless export ccflags-y
  xtensa: replace setup_irq() by request_irq()

Merge tag 'for-linus-5.7-rc1b-tag' of git://git./linux/kernel/git/xen/tip

Pull more xen updates from Juergen Gross:

 - two cleanups

 - fix a boot regression introduced in this merge window

 - fix wrong use of memory allocation flags

* tag 'for-linus-5.7-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: fix booting 32-bit pv guest
  x86/xen: make xen_pvmmu_arch_setup() static
  xen/blkfront: fix memory allocation flags in blkfront_setup_indirect()
  xen: Use evtchn_type_t as a type for event channels

ipc/util.c: sysvipc_find_ipc() should increase position index

If seq_file .next function does not change position index, read after
some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: NeilBrown <neilb@suse.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/b7a20945-e315-8bb0-21e6-3875c14a8494@virtuozzo.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/gcov/fs.c: gcov_seq_next() should increase position index

If seq_file .next function does not change position index, read after
some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: NeilBrown <neilb@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Waiman Long <longman@redhat.com>
Link: http://lkml.kernel.org/r/f65c6ee7-bd00-f910-2f8a-37cc67e4ff88@virtuozzo.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/seq_file.c: seq_read(): add info message about buggy .next functions

Patch series "seq_file .next functions should increase position index".

In Aug 2018 NeilBrown noticed commit 1f4aace60b0e ("fs/seq_file.c:
simplify seq_file iteration code and interface")

"Some ->next functions do not increment *pos when they return NULL...
Note that such ->next functions are buggy and should be fixed.  A simple
demonstration is dd if=/proc/swaps bs=1000 skip=1 Choose any block size
larger than the size of /proc/swaps.  This will always show the whole
last line of /proc/swaps"

Described problem is still actual.  If you make lseek into middle of
last output line following read will output end of last line and whole
last line once again.

  $ dd if=/proc/swaps bs=1  # usual output
  Filename Type Size Used Priority
  /dev/dm-0                             partition 4194812 97536 -2
  104+0 records in
  104+0 records out
  104 bytes copied

  $ dd if=/proc/swaps bs=40 skip=1    # last line was generated twice
  dd: /proc/swaps: cannot skip to specified offset
  v/dm-0                                partition 4194812 97536 -2
  /dev/dm-0                             partition 4194812 97536 -2
  3+1 records in
  3+1 records out
  131 bytes copied

There are lot of other affected files, I've found 30+ including
/proc/net/ip_tables_matches and /proc/sysvipc/*

I've sent patches into maillists of affected subsystems already, this
patch-set fixes the problem in files related to pstore, tracing, gcov,
sysvipc and other subsystems processed via linux-kernel@ mailing list
directly

https://bugzilla.kernel.org/show_bug.cgi?id=206283

This patch (of 4):

Add debug code to seq_read() to detect missed or out-of-tree incorrect
.next seq_file functions.

[akpm@linux-foundation.org: s/pr_info/pr_info_ratelimited/, per Qian Cai]
https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: NeilBrown <neilb@suse.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Waiman Long <longman@redhat.com>
Link: http://lkml.kernel.org/r/244674e5-760c-86bd-d08a-047042881748@virtuozzo.com
Link: http://lkml.kernel.org/r/7c24087c-e280-e580-5b0c-0cdaeb14cd18@virtuozzo.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/dma/tegra20-apb-dma.c: fix platform_get_irq.cocci warnings

Remove dev_err() messages after platform_get_irq*() failures.
platform_get_irq() already prints an error.

Generated by: scripts/coccinelle/api/platform_get_irq.cocci

Fixes: 6c41ac96ad92 ("dmaengine: tegra-apb: Support COMPILE_TEST")
Signed-off-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Vinod Koul <vinod.koul@linux.intel.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Jon Hunter <jonathanh@nvidia.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.2002271133450.2973@hadrien
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

change email address for Pali Rohár

For security reasons I stopped using gmail account and kernel address is
now up-to-date alias to my personal address.

People periodically send me emails to address which they found in source
code of drivers, so this change reflects state where people can contact
me.

[ Added .mailmap entry as per Joe Perches  - Linus ]
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Link: http://lkml.kernel.org/r/20200307104237.8199-1-pali@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

selftests: kmod: test disabling module autoloading

Test that request_module() fails with -ENOENT when
/proc/sys/kernel/modprobe contains (a) a nonexistent path, and (b) an
empty path.

Case (b) is a regression test for the patch "kmod: make request_module()
return an error when autoloading is disabled".

Tested with 'kmod.sh -t 0010 && kmod.sh -t 0011', and also simply with
'kmod.sh' to run all kmod tests.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: NeilBrown <neilb@suse.com>
Link: http://lkml.kernel.org/r/20200312202552.241885-5-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

selftests: kmod: fix handling test numbers above 9

get_test_count() and get_test_enabled() were broken for test numbers
above 9 due to awk interpreting a field specification like '$0010' as
octal rather than decimal.  Fix it by stripping the leading zeroes.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: NeilBrown <neilb@suse.com>
Link: http://lkml.kernel.org/r/20200318230515.171692-5-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

docs: admin-guide: document the kernel.modprobe sysctl

Document the kernel.modprobe sysctl in the same place that all the other
kernel.* sysctls are documented.  Make sure to mention how to use this
sysctl to completely disable module autoloading, and how this sysctl
relates to CONFIG_STATIC_USERMODEHELPER.

[ebiggers@google.com: v5]
Link: http://lkml.kernel.org/r/20200318230515.171692-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: NeilBrown <neilb@suse.com>
Link: http://lkml.kernel.org/r/20200312202552.241885-4-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once()

After request_module(), nothing is stopping the module from being
unloaded until someone takes a reference to it via try_get_module().

The WARN_ONCE() in get_fs_type() is thus user-reachable, via userspace
running 'rmmod' concurrently.

Since WARN_ONCE() is for kernel bugs only, not for user-reachable
situations, downgrade this warning to pr_warn_once().

Keep it printed once only, since the intent of this warning is to detect
a bug in modprobe at boot time.  Printing the warning more than once
wouldn't really provide any useful extra information.

Fixes: 41124db869b7 ("fs: warn in case userspace lied about modprobe return")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jessica Yu <jeyu@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: NeilBrown <neilb@suse.com>
Cc: <stable@vger.kernel.org> [4.13+]
Link: http://lkml.kernel.org/r/20200312202552.241885-3-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kmod: make request_module() return an error when autoloading is disabled

Patch series "module autoloading fixes and cleanups", v5.

This series fixes a bug where request_module() was reporting success to
kernel code when module autoloading had been completely disabled via
'echo > /proc/sys/kernel/modprobe'.

It also addresses the issues raised on the original thread
(https://lkml.kernel.org/lkml/20200310223731.126894-1-ebiggers@kernel.org/T/#u)
bydocumenting the modprobe sysctl, adding a self-test for the empty path
case, and downgrading a user-reachable WARN_ONCE().

This patch (of 4):

It's long been possible to disable kernel module autoloading completely
(while still allowing manual module insertion) by setting
/proc/sys/kernel/modprobe to the empty string.

This can be preferable to setting it to a nonexistent file since it
avoids the overhead of an attempted execve(), avoids potential
deadlocks, and avoids the call to security_kernel_module_request() and
thus on SELinux-based systems eliminates the need to write SELinux rules
to dontaudit module_request.

However, when module autoloading is disabled in this way,
request_module() returns 0.  This is broken because callers expect 0 to
mean that the module was successfully loaded.

Apparently this was never noticed because this method of disabling
module autoloading isn't used much, and also most callers don't use the
return value of request_module() since it's always necessary to check
whether the module registered its functionality or not anyway.

But improperly returning 0 can indeed confuse a few callers, for example
get_fs_type() in fs/filesystems.c where it causes a WARNING to be hit:

if (!fs && (request_module("fs-%.*s", len, name) == 0)) {
fs = __get_fs_type(name, len);
WARN_ONCE(!fs, "request_module fs-%.*s succeeded, but still no fs?\n", len, name);
}

This is easily reproduced with:

echo > /proc/sys/kernel/modprobe
mount -t NONEXISTENT none /

It causes:

request_module fs-NONEXISTENT succeeded, but still no fs?
WARNING: CPU: 1 PID: 1106 at fs/filesystems.c:275 get_fs_type+0xd6/0xf0
[...]

This should actually use pr_warn_once() rather than WARN_ONCE(), since
it's also user-reachable if userspace immediately unloads the module.
Regardless, request_module() should correctly return an error when it
fails.  So let's make it return -ENOENT, which matches the error when
the modprobe binary doesn't exist.

I've also sent patches to document and test this case.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Ben Hutchings <benh@debian.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200310223731.126894-1-ebiggers@kernel.org
Link: http://lkml.kernel.org/r/20200312202552.241885-1-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memremap: set caching mode for PCI P2PDMA memory to WC

PCI BAR IO memory should never be mapped as WB, however prior to this
the PAT bits were set WB and it was typically overridden by MTRR
registers set by the firmware.

Set PCI P2PDMA memory to be UC as this is what it currently, typically,
ends up being mapped as on x86 after the MTRR registers override the
cache setting.

Future use-cases may need to generalize this by adding flags to select
the caching type, as some P2PDMA cases may not want UC.  However, those
use-cases are not upstream yet and this can be changed when they arrive.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric Badger <ebadger@gigaio.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200306170846.9333-8-logang@deltatee.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory_hotplug: add pgprot_t to mhp_params

devm_memremap_pages() is currently used by the PCI P2PDMA code to create
struct page mappings for IO memory.  At present, these mappings are
created with PAGE_KERNEL which implies setting the PAT bits to be WB.
However, on x86, an mtrr register will typically override this and force
the cache type to be UC-.  In the case firmware doesn't set this
register it is effectively WB and will typically result in a machine
check exception when it's accessed.

Other arches are not currently likely to function correctly seeing they
don't have any MTRR registers to fall back on.

To solve this, provide a way to specify the pgprot value explicitly to
arch_add_memory().

Of the arches that support MEMORY_HOTPLUG: x86_64, and arm64 need a
simple change to pass the pgprot_t down to their respective functions
which set up the page tables.  For x86_32, set the page tables
explicitly using _set_memory_prot() (seeing they are already mapped).

For ia64, s390 and sh, reject anything but PAGE_KERNEL settings -- this
should be fine, for now, seeing these architectures don't support
ZONE_DEVICE.

A check in __add_pages() is also added to ensure the pgprot parameter
was set for all arches.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric Badger <ebadger@gigaio.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200306170846.9333-7-logang@deltatee.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc/mm: thread pgprot_t through create_section_mapping()

In prepartion to support a pgprot_t argument for arch_add_memory().

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric Badger <ebadger@gigaio.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200306170846.9333-6-logang@deltatee.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

x86/mm: introduce __set_memory_prot()

For use in the 32bit arch_add_memory() to set the pgprot type of the
memory to add.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric Badger <ebadger@gigaio.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200306170846.9333-5-logang@deltatee.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

x86/mm: thread pgprot_t through init_memory_mapping()

In preparation to support a pgprot_t argument for arch_add_memory().

It's required to move the prototype of init_memory_mapping() seeing the
original location came before the definition of pgprot_t.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric Badger <ebadger@gigaio.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200306170846.9333-4-logang@deltatee.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory_hotplug: rename mhp_restrictions to mhp_params

The mhp_restrictions struct really doesn't specify anything resembling a
restriction anymore so rename it to be mhp_params as it is a list of
extended parameters.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric Badger <ebadger@gigaio.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200306170846.9333-3-logang@deltatee.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory_hotplug: drop the flags field from struct mhp_restrictions

Patch series "Allow setting caching mode in arch_add_memory() for
P2PDMA", v4.

Currently, the page tables created using memremap_pages() are always
created with the PAGE_KERNEL cacheing mode.  However, the P2PDMA code is
creating pages for PCI BAR memory which should never be accessed through
the cache and instead use either WC or UC.  This still works in most
cases, on x86, because the MTRR registers typically override the caching
settings in the page tables for all of the IO memory to be UC-.
However, this tends not to work so well on other arches or some rare x86
machines that have firmware which does not setup the MTRR registers in
this way.

Instead of this, this series proposes a change to arch_add_memory() to
take the pgprot required by the mapping which allows us to explicitly
set pagetable entries for P2PDMA memory to UC.

This changes is pretty routine for most of the arches: x86_64, arm64 and
powerpc simply need to thread the pgprot through to where the page
tables are setup.  x86_32 unfortunately sets up the page tables at boot
so must use _set_memory_prot() to change their caching mode.  ia64, s390
and sh don't appear to have an easy way to change the page tables so,
for now at least, we just return -EINVAL on such mappings and thus they
will not support P2PDMA memory until the work for this is done.  This
should be fine as they don't yet support ZONE_DEVICE.

This patch (of 7):

This variable is not used anywhere and should therefore be removed from
the structure.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Badger <ebadger@gigaio.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Link: http://lkml.kernel.org/r/20200306170846.9333-2-logang@deltatee.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/special: create generic fallbacks for pte_special() and pte_mkspecial()

Currently there are many platforms that dont enable ARCH_HAS_PTE_SPECIAL
but required to define quite similar fallback stubs for special page
table entry helpers such as pte_special() and pte_mkspecial(), as they
get build in generic MM without a config check.  This creates two
generic fallback stub definitions for these helpers, eliminating much
code duplication.

mips platform has a special case where pte_special() and pte_mkspecial()
visibility is wider than what ARCH_HAS_PTE_SPECIAL enablement requires.
This restricts those symbol visibility in order to avoid redefinitions
which is now exposed through this new generic stubs and subsequent build
failure.  arm platform set_pte_at() definition needs to be moved into a
C file just to prevent a build failure.

[anshuman.khandual@arm.com: use defined(CONFIG_ARCH_HAS_PTE_SPECIAL) in mips per Thomas]
Link: http://lkml.kernel.org/r/1583851924-21603-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Guo Ren <guoren@kernel.org> [csky]
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Acked-by: Stafford Horne <shorne@gmail.com> [openrisc]
Acked-by: Helge Deller <deller@gmx.de> [parisc]
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Sam Creasey <sammy@sammy.net>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Link: http://lkml.kernel.org/r/1583802551-15406-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vma: introduce VM_ACCESS_FLAGS

There are many places where all basic VMA access flags (read, write,
exec) are initialized or checked against as a group.  One such example
is during page fault.  Existing vma_is_accessible() wrapper already
creates the notion of VMA accessibility as a group access permissions.

Hence lets just create VM_ACCESS_FLAGS (VM_READ|VM_WRITE|VM_EXEC) which
will not only reduce code duplication but also extend the VMA
accessibility concept in general.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Springer <rspringer@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Link: http://lkml.kernel.org/r/1583391014-8170-3-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS

There are many platforms with exact same value for VM_DATA_DEFAULT_FLAGS
This creates a default value for VM_DATA_DEFAULT_FLAGS in line with the
existing VM_STACK_DEFAULT_FLAGS.  While here, also define some more
macros with standard VMA access flag combinations that are used
frequently across many platforms.  Apart from simplification, this
reduces code duplication as well.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Chris Zankel <chris@zankel.net>
Link: http://lkml.kernel.org/r/1583391014-8170-2-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory.c: add vm_insert_pages()

Add the ability to insert multiple pages at once to a user VM with lower
PTE spinlock operations.

The intention of this patch-set is to reduce atomic ops for tcp zerocopy
receives, which normally hits the same spinlock multiple times
consecutively.

[akpm@linux-foundation.org: pte_alloc() no longer takes the `addr' argument]
[arjunroy@google.com: add missing page_count() check to vm_insert_pages()]
Link: http://lkml.kernel.org/r/20200214005929.104481-1-arjunroy.kdev@gmail.com
[arjunroy@google.com: vm_insert_pages() checks if pte_index defined]
Link: http://lkml.kernel.org/r/20200228054714.204424-2-arjunroy.kdev@gmail.com
Signed-off-by: Arjun Roy <arjunroy@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Miller <davem@davemloft.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: http://lkml.kernel.org/r/20200128025958.43490-2-arjunroy.kdev@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: define pte_index as macro for x86

pte_index() is either defined as a macro (e.g.  sparc64) or as an
inlined function (e.g.  x86).  vm_insert_pages() depends on pte_index
but it is not defined on all platforms (e.g.  m68k).

To fix compilation of vm_insert_pages() on architectures not providing
pte_index(), we perform the following fix:

0. For platforms where it is meaningful, and defined as a macro, no
    change is needed.
1. For platforms where it is meaningful and defined as an inlined
    function, and we want to use it with vm_insert_pages(), we define
    a degenerate macro of the form:  #define pte_index pte_index
2. vm_insert_pages() checks for the existence of a pte_index macro
   definition. If found, it implements a batched insert. If not found,
   it devolves to calling vm_insert_page() in a loop.

This patch implements step 1 for x86.

v3 of this patch fixes a compilation warning for an unused method.
v2 of this patch moved a macro definition to a more readable location.

Signed-off-by: Arjun Roy <arjunroy@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: http://lkml.kernel.org/r/20200228054714.204424-1-arjunroy.kdev@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: bring sparc pte_index() semantics inline with other platforms

pte_index() on platforms other than sparc return a numerical index.  On
sparc, it returns a pte_t*.  This presents an issue for
vm_insert_pages(), which relies on pte_index() to find the offset for a
pte within a pmd, for batched inserts.

This patch:
1. Modifies pte_index() for sparc to return a numerical index, like
   other platforms,
2. Defines pte_entry() for sparc which returns a pte_t*
   (as pte_index() used to),
3. Converts existing sparc callers for pte_index() to use pte_entry().

[sfr@canb.auug.org.au: remove pte_entry and just directly modified pte_offset_kernel instead]
Signed-off-by: Arjun Roy <arjunroy@google.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: David Miller <davem@davemloft.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Arjun Roy <arjunroy.kdev@gmail.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Link: http://lkml.kernel.org/r/20200227105045.6b421d9f@canb.auug.org.au
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory.c: refactor insert_page to prepare for batched-lock insert

Add helper methods for vm_insert_page()/insert_page() to prepare for
vm_insert_pages(), which batch-inserts pages to reduce spinlock
operations when inserting multiple consecutive pages into the user page
table.

The intention of this patch-set is to reduce atomic ops for tcp zerocopy
receives, which normally hits the same spinlock multiple times
consecutively.

Signed-off-by: Arjun Roy <arjunroy@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Miller <davem@davemloft.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: http://lkml.kernel.org/r/20200128025958.43490-1-arjunroy.kdev@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mmap.c: initialize align_offset explicitly for vm_unmapped_area

On passing requirement to vm_unmapped_area, arch_get_unmapped_area and
arch_get_unmapped_area_topdown did not set align_offset.  Internally on
both unmapped_area and unmapped_area_topdown, if info->align_mask is 0,
then info->align_offset was meaningless.

But commit df529cabb7a2 ("mm: mmap: add trace point of
vm_unmapped_area") always prints info->align_offset even though it is
uninitialized.

Fix this uninitialized value issue by setting it to 0 explicitly.

Before:
  vm_unmapped_area: addr=0x755b155000 err=0 total_vm=0x15aaf0 flags=0x1 len=0x109000 lo=0x8000 hi=0x75eed48000 mask=0x0 ofs=0x4022

After:
  vm_unmapped_area: addr=0x74a4ca1000 err=0 total_vm=0x168ab1 flags=0x1 len=0x9000 lo=0x8000 hi=0x753d94b000 mask=0x0 ofs=0x0

Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michel Lespinasse <walken@google.com>
Cc: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20200409094035.19457-1-jaewon31.kim@samsung.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: hugetlb: optionally allocate gigantic hugepages using cma

Commit 944d9fec8d7a ("hugetlb: add support for gigantic page allocation
at runtime") has added the run-time allocation of gigantic pages.

However it actually works only at early stages of the system loading,
when the majority of memory is free.  After some time the memory gets
fragmented by non-movable pages, so the chances to find a contiguous 1GB
block are getting close to zero.  Even dropping caches manually doesn't
help a lot.

At large scale rebooting servers in order to allocate gigantic hugepages
is quite expensive and complex.  At the same time keeping some constant
percentage of memory in reserved hugepages even if the workload isn't
using it is a big waste: not all workloads can benefit from using 1 GB
pages.

The following solution can solve the problem:
1) On boot time a dedicated cma area* is reserved. The size is passed
   as a kernel argument.
2) Run-time allocations of gigantic hugepages are performed using the
   cma allocator and the dedicated cma area

In this case gigantic hugepages can be allocated successfully with a
high probability, however the memory isn't completely wasted if nobody
is using 1GB hugepages: it can be used for pagecache, anon memory, THPs,
etc.

* On a multi-node machine a per-node cma area is allocated on each node.
  Following gigantic hugetlb allocation are using the first available
  numa node if the mask isn't specified by a user.

Usage:
1) configure the kernel to allocate a cma area for hugetlb allocations:
   pass hugetlb_cma=10G as a kernel argument

2) allocate hugetlb pages as usual, e.g.
   echo 10 > /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages

If the option isn't enabled or the allocation of the cma area failed,
the current behavior of the system is preserved.

x86 and arm-64 are covered by this patch, other architectures can be
trivially added later.

The patch contains clean-ups and fixes proposed and implemented by Aslan
Bakirov and Randy Dunlap.  It also contains ideas and suggestions
proposed by Rik van Riel, Michal Hocko and Mike Kravetz.  Thanks!

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Andreas Schaufler <andreas.schaufler@gmx.de>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@kernel.org>
Cc: Aslan Bakirov <aslan@fb.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Link: http://lkml.kernel.org/r/20200407163840.92263-3-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: cma: NUMA node interface

I've noticed that there is no interface exposed by CMA which would let
me to declare contigous memory on particular NUMA node.

This patchset adds the ability to try to allocate contiguous memory on a
specific node.  It will fallback to other nodes if the specified one
doesn't work.

Implement a new method for declaring contigous memory on particular node
and keep cma_declare_contiguous() as a wrapper.

[akpm@linux-foundation.org: build fix]
Signed-off-by: Aslan Bakirov <aslan@fb.com>
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@kernel.org>
Cc: Andreas Schaufler <andreas.schaufler@gmx.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Link: http://lkml.kernel.org/r/20200407163840.92263-2-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>