Recently, the content and examples of the book "The Linux Kernel Module
Programming Guide" are being actively maintained and added on Github[1].
Currently, the book is being regularly built into webpage and pdf
file using Github static page[2].

[1]: https://github.com/sysprog21/lkmpg
[2]: https://sysprog21.github.io/lkmpg/Signed-off-by: Chun-Hung Tseng <henrybear327@gmail.com>
Link: https://lore.kernel.org/r/20210820222152.971174-1-henrybear327@gmail.com
[jc: fixed docs-build warnings]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

x86_64 vmalloc() mappings are no longer "synchronized" among page tables
via faulting since commit 6eb82f99 ("x86/mm: Pre-allocate P4D/PUD
pages for vmalloc area"), since the corresponding P4D or PUD pages are
now preallocated at boot, by preallocate_vmalloc_pages().  Drop the
"lazily synchronized" description for less confusion.

While this file is x86_64-specific, it is worth noting that things are
different for x86_32, where vmalloc()-related changes to `init_mm.pgd` are
synchronized to all page tables in the system during runtime, via
arch_sync_kernel_mappings().  Unfortunately, this synchronization is
subject to race condition, which is further handled via faulting, see
vmalloc_fault().  See commit 4819e15f ("x86/mm/32: Bring back vmalloc
faulting on x86_32") for more details.
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20210818220123.2623-1-yepeilin.cs@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

There is a url for linux-next in the 'applying-patches.rst', but it's
surrounded by backquotes.  So the url doesn't have a hyperlink in the
built document.  To let readers easily move to the page, this commit
puts the url outside of the backquotes so that a hyperlink to the url
can be automatically made.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Link: https://lore.kernel.org/r/20210812095030.4704-1-sj38.park@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

sphinx_rtd_theme 0.5.2 has "docutils<0.17" in its requirements.
docutils 0.17 released this April caused regression in
sphinx_rtd_theme 0.5.1 [1].

By removing docutils and moving sphinx_rtd_theme before Sphinx in
requirements.txt, the requirement of "docutils<0.17" can be met
naturally.

[1]: https://github.com/readthedocs/sphinx_rtd_theme/issues/1112Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Link: https://lore.kernel.org/r/75f14c88-6091-1072-41cb-16b886aee5a0@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

The "TC" variants are supposed to be the choice for traditional
Chinese documents.
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Reviewed-by: Hu Haowen <src.res@email.cn>
Tested-by: Hu Haowen <src.res@email.cn>
Link: https://lore.kernel.org/r/9d8e8fa2-3e7a-3a0a-1a0d-7d797a605ff8@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Quotation marks in "KR" and "JP" variants of Noto CJK fonts are half
width.
xeCJK assumes they are full width by default and does excessive kerning
around them in Korean and Japanese translations.

Give xeCJK proper hints by the \xeCJKDeclareCharClass command.
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/0da9e3c5-2716-f576-1df5-2f28ea69f0e8@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Noto CJK fonts don't provide italic shapes.
The AutoFakeSlant option of fontspec and xeCJK packages can be used as
a workaround.
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/502335cc-9a95-3c2a-7744-6cc56ecaf628@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

CJK documents are much easier to read with a wider baseline stretch.
Applying onehalfspacing option of "setspace" package looks reasonable.

Note: \usepackage{setspace} needs to be before that of hyperref in the
preamble.
The 'extrapackages' key (available since Sphinx 2.3) is for this purpose.
For systems with Sphinx < 2.3, dummy commands of \onehalfspacing and
\singlespacing are provided instead.
One-half spacing is not effective in LaTeX sources generated by such
revisions of Sphinx.
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/547a1f1c-0bb5-20a7-ea0e-951bfc3c3925@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Globally choosing "Noto Sans Mono CJK SC" would result in sub-optimal look
of literal blocks in Latin documents.
Therefore, localize the font choice to translations by adding conf.py under
Documentation/translations/.

The local conf.py is enabled when the command:

    make SPHINXDIRS=translations pdfdocs

is used to build the PDF.
Resulting translations.pdf (under Documentation/output/translations/pdf)
will have properly aligned ascii-art figures.

NOTE: There remain mis-aligned ascii-art figures in Korean translations.
This is due to the font designer's decision to assign slightly narrower
widths (920) to Hangul characters in "Noto Sans Mono CJK KR" than those
of Hanja (Hanzi/Kanji) characters (1000) [1].

[1]: https://github.com/googlefonts/noto-cjk/issues/17Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/79a876fc-a552-f972-4a1b-c6df4cbb36dd@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

In Korean typesetting, inter-phrase spaces in Hangul text have
a similar role as the the inter-word spaces in Latin text.
They can be preserved by the \xeCJKsetup{CJKspace=true} option.
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/68de2e52-e6d1-3f01-c097-15ba7b28a319@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

"Noto Serif CJK SC" and its variants suit better with the roman font
of Latin letters.

On some distros such as Fedora, it is possible to partially install
"Noto Sans CJK" fonts.
So, if the Serif fonts are not found on the system, fall back to the
Sans fonts.
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/5e454140-5d0c-35d4-8c31-3ffb2420793a@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

zh_TW, ko_KR, and ja_JP translations have their preferred glyph sets
different from that of zh_CN.

To switch CJK font in the middle of the translations, introduce custom
LaTeX macros listed below:

    \kerneldocBeginSC
    \kerneldocEndSC
    \kerneldocBeginTC
    \kerneldocEndTC
    \kerneldocBeginKR
    \kerneldocEndKR
    \kerneldocBeginJP
    \kerneldocEndJP

, and embed a pair of macros in each language's index.rst.

NOTE 1: Update of zh_TW/index.rst is deferred to a follow-up change.

NOTE 2: Custom macros added here do not imply \kerneldocCJK(on|off).
This is intentional.  For example, \kerneldocCJKoff needs to be
at the top of Italian translations' index.rst for the footer of
final zh_TW page to be properly typeset.
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/31906baf-7490-68cd-7153-4e4d320fb9b0@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

To make generated LaTeX code portable across systems with different sets
of available fonts, convert font-availability check in python code to
LaTeX code by using a conditional command provided by the "fontspec"
package.

This will help those who run Sphinx on one machine/container and run
latexmk on other machines/containers.

Remove import of check_output as it is unused any more.
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Link: https://lore.kernel.org/r/4baf88af-316d-8aee-240f-6ccbc20907d7@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Since commit 2c12c810 ("scripts/kernel-doc: optionally treat
warnings as errors"), the kernel-doc script will treat warnings as
errors when one of the following conditions is true:

- The KDOC_WERROR environment variable is non-zero
- The KCFLAGS environment variable contains -Werror
- The -Werror parameter is passed to kernel-doc

Checking KCFLAGS for -Werror allows piggy-backing on the C compiler
error handling. However, unlike the C compiler, kernel-doc has no
provision for -Wno-error. This makes compiling the kernel with -Werror
(to catch regressions) and W=1 (to enable more checks) always fail,
without the same possibility as offered by the C compiler to treating
some selected warnings as warnings despite the global -Werror setting.

To fix this, evaluate KDOC_WERROR after KCFLAGS, which allows disabling
the warnings-as-errors behaviour of kernel-doc selectively by setting
KDOC_WERROR=0.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Link: https://lore.kernel.org/r/20210730225401.4401-1-laurent.pinchart+renesas@ideasonboard.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Add translation zh_CN/accounting/psi.rst and zh_CN/accounting/index.rst.
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Reviewed-by: Yanteng Si <siyanteng@loongson.cn>
Link: https://lore.kernel.org/r/20210731084502.571451-1-yang.yang29@zte.com.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translation for the following patches

commit 0ca0d555 ("docs/core-api: Consistent code style")
commit 9912d0bb ("docs: process: submitting-patches.rst: avoid using ReST :doc:`foo` markup")
commit 6349469a ("Documentation/submitting-patches: Document RESEND tag on patches")
commit dbbe7c96 ("docs: networking: drop special stable handling")
commit 7f3f7bfb ("docs: kernel-hacking: hacking.rst: avoid using ReST :doc:`foo` markup")
commit 6ab0493d ("deprecated.rst: Include details on "no_hash_pointers" ")
commit 77167b96 ("docs: submitting-patches: clarify the role of LKML ")
Signed-off-by: Federico Vaga <federico.vaga@vaga.pv.it>
Link: https://lore.kernel.org/r/20210731085513.11820-1-federico.vaga@vaga.pv.itSigned-off-by: Jonathan Corbet <corbet@lwn.net>

After commit e88b3331 ("riscv: mm: add THP support on 64-bit"),
riscv can support THP.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20210805002739.23f44d2d@xhackerSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/infiniband/user_verbs.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Reviewed-by: Puyu Wang <realpuyuwang@gmail.com>
Link: https://lore.kernel.org/r/b7c1577cf9758943bff933c46200c7dff1e1c6e0.1628218477.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/infiniband/user_mad.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Reviewed-by: Puyu Wang <realpuyuwang@gmail.com>
Link: https://lore.kernel.org/r/8859ef2b40b380d7db7548f2e6a2d6fd5397062d.1628218477.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/infiniband/tag_matching.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Reviewed-by: Puyu Wang <realpuyuwang@gmail.com>
Link: https://lore.kernel.org/r/eaed122a0e5d0e3312cf5a495022a9d0be42a831.1628218477.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/infiniband/sysfs.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Reviewed-by: Puyu Wang <realpuyuwang@gmail.com>
Link: https://lore.kernel.org/r/dbd542628b71160f7bddd33a76cb77b127a9b826.1628218477.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/infiniband/opa_vnic.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Reviewed-by: Puyu Wang <realpuyuwang@gmail.com>
Link: https://lore.kernel.org/r/828550a6fb7fded8172c123c37d4c643d2593e53.1628218477.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/infiniband/ipoib.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Reviewed-by: Puyu Wang <realpuyuwang@gmail.com>
Link: https://lore.kernel.org/r/2d71cfe6b11568d9d9c665e829eaf680c249c94a.1628218477.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/infiniband/core_locking.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Reviewed-by: Puyu Wang <realpuyuwang@gmail.com>
Link: https://lore.kernel.org/r/d035d79b2936be762bc001b3a53831f34f72cbb7.1628218477.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/infiniband/index.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Reviewed-by: Puyu Wang <realpuyuwang@gmail.com>
Link: https://lore.kernel.org/r/e3bca9e59f410fe62489e36c5b9a3fab78bc1421.1628218477.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/virt/acrn/cpuid.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/35730828bc65d3912ba27382d5d70ddacee7d8a5.1628212777.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/virt/acrn/io-request.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/291079265a8b0555de4d624d7d11fc5ac37a9422.1628212777.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/virt/acrn/introduction.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/667a6eb64820d2234d12a0c5dd5b642af16c0d99.1628212777.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/virt/acrn/index.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/17a0dac5ecc5bdcc98160bdb028c6876ca38a6bc.1628212777.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/virt/ne_overview.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/a6e1a2275a397d77957be30d1acdfeda9dc836f4.1628212777.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/virt/guest-halt-polling.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/658e255eff55bfdadc1576107bf367a2e80b881a.1628212777.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate Documentation/virt/paravirt_ops.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/abba361233e2a58999ef5d31c20f24370d7724f2.1628212777.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Add virt to .../zh_CN/index and translate it into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/b28d3a530fe0c3635e7be2462fd14a4ae18f0220.1628212777.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Add maintainer information for traditional Chinese documentation.
Signed-off-by: Hu Haowen <src.res@email.cn>
Reviewed-by: Pan Yunwang <panyunwang849@gmail.com>
Link: https://lore.kernel.org/r/20210729155627.41744-3-src.res@email.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Create new translations for zh_TW/process and link them to index.
Signed-off-by: Hu Haowen <src.res@email.cn>
Reviewed-by: Pan Yunwang <panyunwang849@gmail.com>
Link: https://lore.kernel.org/r/20210729155627.41744-2-src.res@email.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Add traditional Chinese translation (zh_TW) for the Linux Kernel
documentation with a series of translated files.
Signed-off-by: Hu Haowen <src.res@email.cn>
Reviewed-by: Pan Yunwang <panyunwang849@gmail.com>
Link: https://lore.kernel.org/r/20210729155627.41744-1-src.res@email.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

The original file has added a former intro in commit b51208d4
("docs: Tweak the top-level Sphinx page") and hence update the Chinese
version for it.
Signed-off-by: Hu Haowen <src.res@email.cn>
Link: https://lore.kernel.org/r/20210608075207.77812-1-src.res@email.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

The documentation previously stated that LKML should be used as *last
resort*. However, scripts/get_maintainer.pl always suggests it and in a
discussion about changing that[0] it turned out that LKML should in fact
receive all patches.

Update documentation to make it clear that all patches should be sent to
LKML by default, in addition to any subsystem-specific lists.

[0]: https://lore.kernel.org/lkml/19a701a8d5837088aa7d8ba594c228c0e040e747.camel@perches.com/Signed-off-by: Hannu Hartikainen <hannu@hrtk.in>
Link: https://lore.kernel.org/r/20210707133634.286840-1-hannu@hrtk.inSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Since kernel commit ff58fa7f ("Documentation: Update CPU hotplug and move it to core-api"),
cpu_hotplug.txt has been removed. We should update it in here.
Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
Link: https://lore.kernel.org/r/1624412269-13155-1-git-send-email-xuyang2018.jy@fujitsu.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Rephrase the "For MDS" section in core-scheduling.rst for the purpose of
making it clearer what is meant by "kernel memory is still considered
untrusted".
Suggested-by: Vineeth Pillai <Vineeth.Pillai@microsoft.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: Joel Fernandes (Google) <joelaf@google.com>
Link: https://lore.kernel.org/r/20210721190250.26095-1-fmdefrancesco@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>