Pull Kbuild updates from Masahiro Yamada:

 - Fix false-positive build warnings for ARCH=ia64 builds

 - Optimize dictionary size for module compression with xz

 - Check the compiler and linker versions in Kconfig

 - Fix misuse of extra-y

 - Support DWARF v5 debug info

 - Clamp SUBLEVEL to 255 because stable releases 4.4.x and 4.9.x
   exceeded the limit

 - Add generic syscall{tbl,hdr}.sh for cleanups across arches

 - Minor cleanups of genksyms

 - Minor cleanups of Kconfig

* tag 'kbuild-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (38 commits)
  initramfs: Remove redundant dependency of RD_ZSTD on BLK_DEV_INITRD
  kbuild: remove deprecated 'always' and 'hostprogs-y/m'
  kbuild: parse C= and M= before changing the working directory
  kbuild: reuse this-makefile to define abs_srctree
  kconfig: unify rule of config, menuconfig, nconfig, gconfig, xconfig
  kconfig: omit --oldaskconfig option for 'make config'
  kconfig: fix 'invalid option' for help option
  kconfig: remove dead code in conf_askvalue()
  kconfig: clean up nested if-conditionals in check_conf()
  kconfig: Remove duplicate call to sym_get_string_value()
  Makefile: Remove # characters from compiler string
  Makefile: reuse CC_VERSION_TEXT
  kbuild: check the minimum linker version in Kconfig
  kbuild: remove ld-version macro
  scripts: add generic syscallhdr.sh
  scripts: add generic syscalltbl.sh
  arch: syscalls: remove $(srctree)/ prefix from syscall tables
  arch: syscalls: add missing FORCE and fix 'targets' to make if_changed work
  gen_compile_commands: prune some directories
  kbuild: simplify access to the kernel's version
  ...

As commit d0e628cd817f ("kbuild: doc: clarify the difference between
extra-y and always-y") explained, extra-y should be used for listing
the prerequisites of vmlinux.

These targets are not related to vmlinux. always-y is a better fix.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>

sort -C is like sort -c >/dev/null but less portable. It fails on
busybox sort (i.e alpine linux).

Signed-off-by: Iskren Chernev <iskren.chernev@gmail.com>
Fixes: ea5b8b5eb004 ("dt-bindings: Add a minimum version check for dtschema")
Link: https://lore.kernel.org/r/20210201165829.58656-1-iskren.chernev@gmail.com
Signed-off-by: Rob Herring <robh@kernel.org>

If DT_SCHEMA_FILES is specified and contains more than one file paths,
'make dtbs_check' fails with the following message:

  $ make dtbs_check DT_SCHEMA_FILES="path/to/schema1.yaml path/to/schema2.yaml"
  SCHEMA  Documentation/devicetree/bindings/processed-schema.json
  Documentation/devicetree/bindings/Makefile:77: recipe for target 'Documentation/devicetree/bindings/processed-schema.json' failed
  make[1]: *** [Documentation/devicetree/bindings/processed-schema.json] Error 255
  make[1]: *** Deleting file 'Documentation/devicetree/bindings/processed-schema.json'
  Makefile:1364: recipe for target 'dt_binding_check' failed
  make: *** [dt_binding_check] Error 2

The error code 255 is returned by 'dt-mk-schema' when invoked as
'dt-mk-schema -j -u @<tmp-file>', where '<tmp-file>' is a temporary
file that is generated to contain a list of SPACE delimited schema
file paths, as indicated via DT_SCHEMA_FILES.

However, it seems the file format has been recently changed in
'dt-mk-schema', which now expects each schema path to be provided on
a separate line:

 $ dt-mk-schema --version
 2020.12.dev4+g6de1c45

Therefore, let's change '<tmp-file>' content format from

 path/to/schema1.yaml path/to/schema2.yaml ... path/to/schemaN.yaml

to

 path/to/schema1.yaml
 path/to/schema2.yaml
 ...
 path/to/schemaN.yaml

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
Link: https://lore.kernel.org/r/2519b8bde507ca6ccea9765ea197adaaa69a66d5.1605712328.git.cristian.ciocaltea@gmail.com
Signed-off-by: Rob Herring <robh@kernel.org>

A broken schema file now causes make to exit and 'make -k' no longer works
now that dt-doc-validate is called from a single make rule.

As yamllint is optional, we shouldn't stop on yamllint errors either. Also,
it seems some old versions of yamllint don't work.

Signed-off-by: Rob Herring <robh@kernel.org>

Add a yamllint config file and support for running yamllint on DT
binding schema files. This runs on the whole tree as yamllint is Python
and suffers from Python's slow startup times.

Users can run on individual files doing:

yamllint -c Documentation/devicetree/bindings/.yamllint <binding file>

Link: https://lore.kernel.org/r/20201009170557.168785-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

As the number of binding schemas has grown, the time to run
dt_binding_check has gotten pretty slow. A large part of this is due to
the slow startup time of Python (a well documented problem). There's not
currently any benefit to running dt-doc-validate one file at a time, so
let's switch it to run a single rule. Doing this means we loose the make
parallelism, but we can use xargs instead. This speeds up the validation
time from several minutes to <10 sec.

Since the validation is a single step with no output, we move running it
as part of the processed-schema-examples.json target. We also need to
reorder the extra-y entries so the validation is run first rather than
after all the examples are extracted.

Signed-off-by: Rob Herring <robh@kernel.org>

Change the format of processed-schema* from yaml to json to speed up
validation. With json output, using xargs and appending the output won't
work since json has explicit list begin and end characters. Instead,
we pass the schema files as a list in a temp file.

The parsing time for the processed schema goes down from ~2sec to 70ms.
Also, 'make dtbs_check' becomes 33% faster.

Some error messages are affected by this change. For example, "True was
expected" becomes "... is not of type 'boolean'". The order of messages
is also changed.

Signed-off-by: Andrei Ziureaev <andrei.ziureaev@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>

dtschema release 2020.8.1 gained several additions to help performance.
dt-doc-validate can now take a list of files and directories, and
dt-mk-schema can store the processed schema in JSON which is much faster
to parse than YAML. Utilizing both of these changes results in a 3-4x
speed improvement in running dt_binding_check.

There's also additional meta-schema checks which binding schemas should
be checked against.

Signed-off-by: Rob Herring <robh@kernel.org>

There are two processed schema files:

 - processed-schema-examples.yaml

    Used for 'make dt_binding_check'. This is always a full schema.

 - processed-schema.yaml

    Used for 'make dtbs_check'. This may be a full schema, or a smaller
    subset if DT_SCHEMA_FILES is given by a user.

If DT_SCHEMA_FILES is not specified, they are the same. You can copy
the former to the latter instead of running dt-mk-schema twice. This
saves the cpu time a lot when you do 'make dt_binding_check dtbs_check'
because building the full schema takes a couple of seconds.

If DT_SCHEMA_FILES is specified, processed-schema.yaml is generated
based on the specified yaml files.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20200625170434.635114-4-masahiroy@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>