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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
| commit | f4cdf7ca9a1fdcca413157df19753f388a5a224e (patch) | |
| tree | 60a31895b2446cd7fa27514e8c2843534a0de0da /Documentation/userspace-api/netlink/c-code-gen.rst | |
| download | linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip | |
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab:
- v4l2-core: added ISP statistics support and per-block validation
- v4l2-core: Allow unknown HDR10 white point and luminance
- New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor
- New codec: Milos: VPU v2.0 codec support
- isp driver: gained support for Dreamchip RPPX1 ISP framework
- vsp1 driver: gained support for RZ/T2H and RZ/N2H
- Novalake driver: gained CVS support for new NVL hardware
- dvb-core: fix feed leak on failed DMX_ADD_PID
- several driver fixes, cleanups and minor improvements
* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
media: ipu-bridge: check all DMI entries when overriding sensor rotation
media: v4l2-async: avoid deleting unlinked ASC entry on link error
media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
media: intel/ipu6: fix async notifier cleanup leak on parse error
media: staging/ipu7: fix async notifier UAF on probe error path
media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
media: rcar-isp: Fix VSPX reference leaks
media: rcar-isp: Release ISPCORE resources
media: i2c: imx415: Release runtime PM reference on VBLANK error
media: i2c: imx415: Return test pattern write errors
media: renesas: vsp1: Declare index variables in for loop statement
media: renesas: vsp1: Make reset control optional to support platforms without a reset line
media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
media: nxp: imx8-isi: Add additional 32-bit RGB format support
media: nxp: imx8-isi: Add 16-bit raw Bayer format support
media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
media: nxp: imx8-isi: Correct color map between V4L2 and ISI
...
Diffstat (limited to 'Documentation/userspace-api/netlink/c-code-gen.rst')
| -rw-r--r-- | Documentation/userspace-api/netlink/c-code-gen.rst | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/Documentation/userspace-api/netlink/c-code-gen.rst b/Documentation/userspace-api/netlink/c-code-gen.rst new file mode 100644 index 000000000..46415e6d6 --- /dev/null +++ b/Documentation/userspace-api/netlink/c-code-gen.rst @@ -0,0 +1,109 @@ +.. SPDX-License-Identifier: BSD-3-Clause + +============================== +Netlink spec C code generation +============================== + +This document describes how Netlink specifications are used to render +C code (uAPI, policies etc.). It also defines the additional properties +allowed in older families by the ``genetlink-c`` protocol level, +to control the naming. + +For brevity this document refers to ``name`` properties of various +objects by the object type. For example ``$attr`` is the value +of ``name`` in an attribute, and ``$family`` is the name of the +family (the global ``name`` property). + +The upper case is used to denote literal values, e.g. ``$family-CMD`` +means the concatenation of ``$family``, a dash character, and the literal +``CMD``. + +The names of ``#defines`` and enum values are always converted to upper case, +and with dashes (``-``) replaced by underscores (``_``). + +If the constructed name is a C keyword, an extra underscore is +appended (``do`` -> ``do_``). + +Globals +======= + +``c-family-name`` controls the name of the ``#define`` for the family +name, default is ``$family-FAMILY-NAME``. + +``c-version-name`` controls the name of the ``#define`` for the version +of the family, default is ``$family-FAMILY-VERSION``. + +``max-by-define`` selects if max values for enums are defined as a +``#define`` rather than inside the enum. + +Definitions +=========== + +Constants +--------- + +Every constant is rendered as a ``#define``. +The name of the constant is ``$family-$constant`` and the value +is rendered as a string or integer according to its type in the spec. + +Enums and flags +--------------- + +Enums are named ``$family-$enum``. The full name can be set directly +or suppressed by specifying the ``enum-name`` property. +Default entry name is ``$family-$enum-$entry``. +If ``name-prefix`` is specified it replaces the ``$family-$enum`` +portion of the entry name. + +Boolean ``render-max`` controls creation of the max values +(which are enabled by default for attribute enums). These max +values are named ``__$pfx-MAX`` and ``$pfx-MAX``. The name +of the first value can be overridden via ``enum-cnt-name`` property. + +Attributes +========== + +Each attribute set (excluding fractional sets) is rendered as an enum. + +Attribute enums are traditionally unnamed in netlink headers. +If naming is desired ``enum-name`` can be used to specify the name. + +The default attribute name prefix is ``$family-A`` if the name of the set +is the same as the name of the family and ``$family-A-$set`` if the names +differ. The prefix can be overridden by the ``name-prefix`` property of a set. +The rest of the section will refer to the prefix as ``$pfx``. + +Attributes are named ``$pfx-$attribute``. + +Attribute enums end with two special values ``__$pfx-MAX`` and ``$pfx-MAX`` +which are used for sizing attribute tables. +These two names can be specified directly with the ``attr-cnt-name`` +and ``attr-max-name`` properties respectively. + +If ``max-by-define`` is set to ``true`` at the global level ``attr-max-name`` +will be specified as a ``#define`` rather than an enum value. + +Operations +========== + +Operations are named ``$family-CMD-$operation``. +If ``name-prefix`` is specified it replaces the ``$family-CMD`` +portion of the name. + +Similarly to attribute enums operation enums end with special count and max +attributes. For operations those attributes can be renamed with +``cmd-cnt-name`` and ``cmd-max-name``. Max will be a define if ``max-by-define`` +is ``true``. + +Multicast groups +================ + +Each multicast group gets a define rendered into the kernel uAPI header. +The name of the define is ``$family-MCGRP-$group``, and can be overwritten +with the ``c-define-name`` property. + +Code generation +=============== + +uAPI header is assumed to come from ``<linux/$family.h>`` in the default header +search path. It can be changed using the ``uapi-header`` global property. |
