diff options
Diffstat (limited to 'Documentation/userspace-api')
22 files changed, 1163 insertions, 17 deletions
diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst index eb045fc495a4..0a1882e296ae 100644 --- a/Documentation/userspace-api/ioctl/ioctl-number.rst +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst @@ -201,7 +201,6 @@ Code Seq# Include File Comments 'V' all linux/videodev2.h conflict! 'V' C0 linux/ivtvfb.h conflict! 'V' C0 linux/ivtv.h conflict! -'V' C0 media/davinci/vpfe_capture.h conflict! 'V' C0 media/si4713.h conflict! 'W' 00-1F linux/watchdog.h conflict! 'W' 00-1F linux/wanrouter.h conflict! (pre 3.9) @@ -222,6 +221,7 @@ Code Seq# Include File Comments 'a' 00-0F drivers/crypto/qat/qat_common/adf_cfg_common.h conflict! qat driver 'b' 00-FF conflict! bit3 vme host bridge <mailto:natalia@nikhefk.nikhef.nl> +'b' 00-0F linux/dma-buf.h conflict! 'c' all linux/cm4000_cs.h conflict! 'c' 00-7F linux/comstats.h conflict! 'c' 00-7F linux/coda.h conflict! diff --git a/Documentation/userspace-api/iommufd.rst b/Documentation/userspace-api/iommufd.rst index 79dd9eb51587..aa004faed5fd 100644 --- a/Documentation/userspace-api/iommufd.rst +++ b/Documentation/userspace-api/iommufd.rst @@ -165,7 +165,7 @@ Multiple io_pagetable-s, through their iopt_area-s, can share a single iopt_pages which avoids multi-pinning and double accounting of page consumption. -iommufd_ioas is sharable between subsystems, e.g. VFIO and VDPA, as long as +iommufd_ioas is shareable between subsystems, e.g. VFIO and VDPA, as long as devices managed by different subsystems are bound to a same iommufd. IOMMUFD User API diff --git a/Documentation/userspace-api/media/drivers/st-vgxy61.rst b/Documentation/userspace-api/media/drivers/st-vgxy61.rst index d9e3b80e3a96..17ac15afa77c 100644 --- a/Documentation/userspace-api/media/drivers/st-vgxy61.rst +++ b/Documentation/userspace-api/media/drivers/st-vgxy61.rst @@ -18,7 +18,7 @@ The ST VGXY61 driver implements the following controls: * - HDR linearize - The merger outputs a long exposure capture as long as it is not saturated. - * - HDR substraction + * - HDR subtraction - This involves subtracting the short exposure frame from the long exposure frame. * - No HDR diff --git a/Documentation/userspace-api/media/rc/lirc-set-wideband-receiver.rst b/Documentation/userspace-api/media/rc/lirc-set-wideband-receiver.rst index c9d578e291b8..5ae8fac8ed4f 100644 --- a/Documentation/userspace-api/media/rc/lirc-set-wideband-receiver.rst +++ b/Documentation/userspace-api/media/rc/lirc-set-wideband-receiver.rst @@ -43,7 +43,7 @@ reduced range of reception. .. note:: - Wide band receiver might be implictly enabled if you enable + Wide band receiver might be implicitly enabled if you enable carrier reports. In that case it will be disabled as soon as you disable carrier reports. Trying to disable wide band receiver while carrier reports are active will do nothing. diff --git a/Documentation/userspace-api/media/rc/rc-protos.rst b/Documentation/userspace-api/media/rc/rc-protos.rst index a2eab3b45647..2a888ff5829f 100644 --- a/Documentation/userspace-api/media/rc/rc-protos.rst +++ b/Documentation/userspace-api/media/rc/rc-protos.rst @@ -75,7 +75,7 @@ protocol, or the manchester BPF decoder. - Command There is a variant of rc5 called either rc5x or extended rc5 -where there the second stop bit is the 6th commmand bit, but inverted. +where there the second stop bit is the 6th command bit, but inverted. This is done so it the scancodes and encoding is compatible with existing schemes. This bit is stored in bit 6 of the scancode, inverted. This is done to keep it compatible with plain rc-5 where there are two start bits. diff --git a/Documentation/userspace-api/media/rc/rc-tables.rst b/Documentation/userspace-api/media/rc/rc-tables.rst index 28ed94088015..aab99260fef5 100644 --- a/Documentation/userspace-api/media/rc/rc-tables.rst +++ b/Documentation/userspace-api/media/rc/rc-tables.rst @@ -628,7 +628,7 @@ the remote via /dev/input/event devices. - Put device into zoom/full screen mode - - ZOOM / FULL SCREEN / ZOOM+ / HIDE PANNEL / SWITCH + - ZOOM / FULL SCREEN / ZOOM+ / HIDE PANEL / SWITCH - .. row 80 diff --git a/Documentation/userspace-api/media/v4l/dev-sliced-vbi.rst b/Documentation/userspace-api/media/v4l/dev-sliced-vbi.rst index 44415822c7c5..42cdb0a9f786 100644 --- a/Documentation/userspace-api/media/v4l/dev-sliced-vbi.rst +++ b/Documentation/userspace-api/media/v4l/dev-sliced-vbi.rst @@ -490,7 +490,7 @@ struct v4l2_mpeg_vbi_fmt_ivtv - An alternate form of the sliced VBI data payload used when 36 lines of sliced VBI data are present. No line masks are provided in this form of the payload; all valid line mask bits are - implcitly set. + implicitly set. * - } - diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec-stateless.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec-stateless.rst index cd33857d947d..3d8411acd5b8 100644 --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec-stateless.rst +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec-stateless.rst @@ -1213,7 +1213,7 @@ FWHT Flags - Luma AC coefficient table index. * - __s8 - ``y_dc_delta`` - - Luma DC delta vaue. + - Luma DC delta value. * - __s8 - ``y2_dc_delta`` - Y2 block DC delta value. diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-jpeg.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-jpeg.rst index 60f9a09422d6..522095c08469 100644 --- a/Documentation/userspace-api/media/v4l/ext-ctrls-jpeg.rst +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-jpeg.rst @@ -8,7 +8,7 @@ JPEG Control Reference The JPEG class includes controls for common features of JPEG encoders and decoders. Currently it includes features for codecs implementing -progressive baseline DCT compression process with Huffman entrophy +progressive baseline DCT compression process with Huffman entropy coding. diff --git a/Documentation/userspace-api/media/v4l/hist-v4l2.rst b/Documentation/userspace-api/media/v4l/hist-v4l2.rst index dbc04374dc22..cdc11e9a0f32 100644 --- a/Documentation/userspace-api/media/v4l/hist-v4l2.rst +++ b/Documentation/userspace-api/media/v4l/hist-v4l2.rst @@ -47,7 +47,7 @@ Codec API was released. 1998-11-08: Many minor changes. Most symbols have been renamed. Some material changes to struct v4l2_capability. -1998-11-12: The read/write directon of some ioctls was misdefined. +1998-11-12: The read/write direction of some ioctls was misdefined. 1998-11-14: ``V4L2_PIX_FMT_RGB24`` changed to ``V4L2_PIX_FMT_BGR24``, and ``V4L2_PIX_FMT_RGB32`` changed to ``V4L2_PIX_FMT_BGR32``. Audio @@ -145,7 +145,7 @@ common Linux driver API conventions. ``VIDIOC_G_INFMT``, ``VIDIOC_S_OUTFMT``, ``VIDIOC_G_OUTFMT``, ``VIDIOC_S_VBIFMT`` and ``VIDIOC_G_VBIFMT``. The image format struct v4l2_format was renamed to struct v4l2_pix_format, while - struct v4l2_format is now the envelopping structure + struct v4l2_format is now the enveloping structure for all format negotiations. 5. Similar to the changes above, the ``VIDIOC_G_PARM`` and diff --git a/Documentation/userspace-api/media/v4l/pixfmt-packed-yuv.rst b/Documentation/userspace-api/media/v4l/pixfmt-packed-yuv.rst index bf283a1b5581..24a771542059 100644 --- a/Documentation/userspace-api/media/v4l/pixfmt-packed-yuv.rst +++ b/Documentation/userspace-api/media/v4l/pixfmt-packed-yuv.rst @@ -262,7 +262,12 @@ the second byte and Y'\ :sub:`7-0` in the third byte. ================= These formats, commonly referred to as YUYV or YUY2, subsample the chroma -components horizontally by 2, storing 2 pixels in 4 bytes. +components horizontally by 2, storing 2 pixels in a container. The container +is 32-bits for 8-bit formats, and 64-bits for 10+-bit formats. + +The packed YUYV formats with more than 8 bits per component are stored as four +16-bit little-endian words. Each word's most significant bits contain one +component, and the least significant bits are zero padding. .. raw:: latex @@ -270,7 +275,7 @@ components horizontally by 2, storing 2 pixels in 4 bytes. .. tabularcolumns:: |p{3.4cm}|p{1.2cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}| -.. flat-table:: Packed YUV 4:2:2 Formats +.. flat-table:: Packed YUV 4:2:2 Formats in 32-bit container :header-rows: 1 :stub-columns: 0 @@ -337,6 +342,46 @@ components horizontally by 2, storing 2 pixels in 4 bytes. - Y'\ :sub:`3` - Cb\ :sub:`2` +.. tabularcolumns:: |p{3.4cm}|p{1.2cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}| + +.. flat-table:: Packed YUV 4:2:2 Formats in 64-bit container + :header-rows: 1 + :stub-columns: 0 + + * - Identifier + - Code + - Word 0 + - Word 1 + - Word 2 + - Word 3 + * .. _V4L2-PIX-FMT-Y210: + + - ``V4L2_PIX_FMT_Y210`` + - 'Y210' + + - Y'\ :sub:`0` (bits 15-6) + - Cb\ :sub:`0` (bits 15-6) + - Y'\ :sub:`1` (bits 15-6) + - Cr\ :sub:`0` (bits 15-6) + * .. _V4L2-PIX-FMT-Y212: + + - ``V4L2_PIX_FMT_Y212`` + - 'Y212' + + - Y'\ :sub:`0` (bits 15-4) + - Cb\ :sub:`0` (bits 15-4) + - Y'\ :sub:`1` (bits 15-4) + - Cr\ :sub:`0` (bits 15-4) + * .. _V4L2-PIX-FMT-Y216: + + - ``V4L2_PIX_FMT_Y216`` + - 'Y216' + + - Y'\ :sub:`0` (bits 15-0) + - Cb\ :sub:`0` (bits 15-0) + - Y'\ :sub:`1` (bits 15-0) + - Cr\ :sub:`0` (bits 15-0) + .. raw:: latex \normalsize diff --git a/Documentation/userspace-api/media/v4l/pixfmt-rgb.rst b/Documentation/userspace-api/media/v4l/pixfmt-rgb.rst index 30f51cd33f99..d330aeb4d3eb 100644 --- a/Documentation/userspace-api/media/v4l/pixfmt-rgb.rst +++ b/Documentation/userspace-api/media/v4l/pixfmt-rgb.rst @@ -763,6 +763,200 @@ nomenclature that instead use the order of components as seen in a 24- or \normalsize +10 Bits Per Component +===================== + +These formats store a 30-bit RGB triplet with an optional 2 bit alpha in four +bytes. They are named based on the order of the RGB components as seen in a +32-bit word, which is then stored in memory in little endian byte order +(unless otherwise noted by the presence of bit 31 in the 4CC value), and on the +number of bits for each component. + +.. raw:: latex + + \begingroup + \tiny + \setlength{\tabcolsep}{2pt} + +.. tabularcolumns:: |p{2.8cm}|p{2.0cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}|p{0.22cm}| + + +.. flat-table:: RGB Formats 10 Bits Per Color Component + :header-rows: 2 + :stub-columns: 0 + + * - Identifier + - Code + - :cspan:`7` Byte 0 in memory + - :cspan:`7` Byte 1 + - :cspan:`7` Byte 2 + - :cspan:`7` Byte 3 + * - + - + - 7 + - 6 + - 5 + - 4 + - 3 + - 2 + - 1 + - 0 + + - 7 + - 6 + - 5 + - 4 + - 3 + - 2 + - 1 + - 0 + + - 7 + - 6 + - 5 + - 4 + - 3 + - 2 + - 1 + - 0 + + - 7 + - 6 + - 5 + - 4 + - 3 + - 2 + - 1 + - 0 + * .. _V4L2-PIX-FMT-RGBX1010102: + + - ``V4L2_PIX_FMT_RGBX1010102`` + - 'RX30' + + - b\ :sub:`5` + - b\ :sub:`4` + - b\ :sub:`3` + - b\ :sub:`2` + - b\ :sub:`1` + - b\ :sub:`0` + - x + - x + + - g\ :sub:`3` + - g\ :sub:`2` + - g\ :sub:`1` + - g\ :sub:`0` + - b\ :sub:`9` + - b\ :sub:`8` + - b\ :sub:`7` + - b\ :sub:`6` + + - r\ :sub:`1` + - r\ :sub:`0` + - g\ :sub:`9` + - g\ :sub:`8` + - g\ :sub:`7` + - g\ :sub:`6` + - g\ :sub:`5` + - g\ :sub:`4` + + - r\ :sub:`9` + - r\ :sub:`8` + - r\ :sub:`7` + - r\ :sub:`6` + - r\ :sub:`5` + - r\ :sub:`4` + - r\ :sub:`3` + - r\ :sub:`2` + - + * .. _V4L2-PIX-FMT-RGBA1010102: + + - ``V4L2_PIX_FMT_RGBA1010102`` + - 'RA30' + + - b\ :sub:`5` + - b\ :sub:`4` + - b\ :sub:`3` + - b\ :sub:`2` + - b\ :sub:`1` + - b\ :sub:`0` + - a\ :sub:`1` + - a\ :sub:`0` + + - g\ :sub:`3` + - g\ :sub:`2` + - g\ :sub:`1` + - g\ :sub:`0` + - b\ :sub:`9` + - b\ :sub:`8` + - b\ :sub:`7` + - b\ :sub:`6` + + - r\ :sub:`1` + - r\ :sub:`0` + - g\ :sub:`9` + - g\ :sub:`8` + - g\ :sub:`7` + - g\ :sub:`6` + - g\ :sub:`5` + - g\ :sub:`4` + + - r\ :sub:`9` + - r\ :sub:`8` + - r\ :sub:`7` + - r\ :sub:`6` + - r\ :sub:`5` + - r\ :sub:`4` + - r\ :sub:`3` + - r\ :sub:`2` + - + * .. _V4L2-PIX-FMT-ARGB2101010: + + - ``V4L2_PIX_FMT_ARGB2101010`` + - 'AR30' + + - b\ :sub:`7` + - b\ :sub:`6` + - b\ :sub:`5` + - b\ :sub:`4` + - b\ :sub:`3` + - b\ :sub:`2` + - b\ :sub:`1` + - b\ :sub:`0` + + - g\ :sub:`5` + - g\ :sub:`4` + - g\ :sub:`3` + - g\ :sub:`2` + - g\ :sub:`1` + - g\ :sub:`0` + - b\ :sub:`9` + - b\ :sub:`8` + + - r\ :sub:`3` + - r\ :sub:`2` + - r\ :sub:`1` + - r\ :sub:`0` + - g\ :sub:`9` + - g\ :sub:`8` + - g\ :sub:`7` + - g\ :sub:`6` + + - a\ :sub:`1` + - a\ :sub:`0` + - r\ :sub:`9` + - r\ :sub:`8` + - r\ :sub:`7` + - r\ :sub:`6` + - r\ :sub:`5` + - r\ :sub:`4` + - + +.. raw:: latex + + \endgroup + + Deprecated RGB Formats ====================== diff --git a/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst b/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst index 6a387f9df3ba..62078a01de76 100644 --- a/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst +++ b/Documentation/userspace-api/media/v4l/pixfmt-yuv-luma.rst @@ -14,7 +14,7 @@ are often referred to as greyscale formats. - In all the tables that follow, bit 7 is the most significant bit in a byte. - Formats are described with the minimum number of pixels needed to create a byte-aligned repeating pattern. `...` indicates repetition of the pattern. - - Y'\ :sub:`x`\ [9:2] denotes bits 9 to 2 of the Y' value for pixel at colum + - Y'\ :sub:`x`\ [9:2] denotes bits 9 to 2 of the Y' value for pixel at column `x`. - `0` denotes padding bits set to 0. diff --git a/Documentation/userspace-api/media/v4l/subdev-formats.rst b/Documentation/userspace-api/media/v4l/subdev-formats.rst index 16ef3b41932e..a3a35eeed708 100644 --- a/Documentation/userspace-api/media/v4l/subdev-formats.rst +++ b/Documentation/userspace-api/media/v4l/subdev-formats.rst @@ -949,6 +949,43 @@ The following tables list existing packed RGB formats. - b\ :sub:`2` - b\ :sub:`1` - b\ :sub:`0` + * .. _MEDIA-BUS-FMT-BGR666-1X18: + + - MEDIA_BUS_FMT_BGR666_1X18 + - 0x1023 + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - b\ :sub:`5` + - b\ :sub:`4` + - b\ :sub:`3` + - b\ :sub:`2` + - b\ :sub:`1` + - b\ :sub:`0` + - g\ :sub:`5` + - g\ :sub:`4` + - g\ :sub:`3` + - g\ :sub:`2` + - g\ :sub:`1` + - g\ :sub:`0` + - r\ :sub:`5` + - r\ :sub:`4` + - r\ :sub:`3` + - r\ :sub:`2` + - r\ :sub:`1` + - r\ :sub:`0` * .. _MEDIA-BUS-FMT-RBG888-1X24: - MEDIA_BUS_FMT_RBG888_1X24 @@ -1023,6 +1060,80 @@ The following tables list existing packed RGB formats. - b\ :sub:`2` - b\ :sub:`1` - b\ :sub:`0` + * .. _MEDIA-BUS-FMT-BGR666-1X24_CPADHI: + + - MEDIA_BUS_FMT_BGR666_1X24_CPADHI + - 0x1024 + - + - + - + - + - + - + - + - + - + - 0 + - 0 + - b\ :sub:`5` + - b\ :sub:`4` + - b\ :sub:`3` + - b\ :sub:`2` + - b\ :sub:`1` + - b\ :sub:`0` + - 0 + - 0 + - g\ :sub:`5` + - g\ :sub:`4` + - g\ :sub:`3` + - g\ :sub:`2` + - g\ :sub:`1` + - g\ :sub:`0` + - 0 + - 0 + - r\ :sub:`5` + - r\ :sub:`4` + - r\ :sub:`3` + - r\ :sub:`2` + - r\ :sub:`1` + - r\ :sub:`0` + * .. _MEDIA-BUS-FMT-RGB565-1X24_CPADHI: + + - MEDIA_BUS_FMT_RGB565_1X24_CPADHI + - 0x1022 + - + - + - + - + - + - + - + - + - + - 0 + - 0 + - 0 + - r\ :sub:`4` + - r\ :sub:`3` + - r\ :sub:`2` + - r\ :sub:`1` + - r\ :sub:`0` + - 0 + - 0 + - g\ :sub:`5` + - g\ :sub:`4` + - g\ :sub:`3` + - g\ :sub:`2` + - g\ :sub:`1` + - g\ :sub:`0` + - 0 + - 0 + - 0 + - b\ :sub:`4` + - b\ :sub:`3` + - b\ :sub:`2` + - b\ :sub:`1` + - b\ :sub:`0` * .. _MEDIA-BUS-FMT-BGR888-1X24: - MEDIA_BUS_FMT_BGR888_1X24 diff --git a/Documentation/userspace-api/media/v4l/vidioc-cropcap.rst b/Documentation/userspace-api/media/v4l/vidioc-cropcap.rst index 551ac9d3c6ef..7f10f0bbcfd3 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-cropcap.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-cropcap.rst @@ -71,7 +71,7 @@ overlay devices. - Default cropping rectangle, it shall cover the "whole picture". Assuming pixel aspect 1/1 this could be for example a 640 × 480 rectangle for NTSC, a 768 × 576 rectangle for PAL and SECAM - centered over the active picture area. The same co-ordinate system + centered over the active picture area. The same coordinate system as for ``bounds`` is used. * - struct :c:type:`v4l2_fract` - ``pixelaspect`` 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 000000000000..89de42c13350 --- /dev/null +++ b/Documentation/userspace-api/netlink/c-code-gen.rst @@ -0,0 +1,107 @@ +.. 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-$enum`` +portion of the entry name. + +Boolean ``render-max`` controls creation of the max values +(which are enabled by default for attribute enums). + +Attributes +========== + +Each attribute set (excluding fractional sets) is rendered as an enum. + +Attribute enums are traditionally unnamed in netlink headers. +If naming is desired ``enum-name`` can be used to specify the name. + +The default attribute name prefix is ``$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. diff --git a/Documentation/userspace-api/netlink/genetlink-legacy.rst b/Documentation/userspace-api/netlink/genetlink-legacy.rst new file mode 100644 index 000000000000..3bf0bcdf21d8 --- /dev/null +++ b/Documentation/userspace-api/netlink/genetlink-legacy.rst @@ -0,0 +1,178 @@ +.. SPDX-License-Identifier: BSD-3-Clause + +================================================================= +Netlink specification support for legacy Generic Netlink families +================================================================= + +This document describes the many additional quirks and properties +required to describe older Generic Netlink families which form +the ``genetlink-legacy`` protocol level. + +The spec is a work in progress, some of the quirks are just documented +for future reference. + +Specification (defined) +======================= + +Attribute type nests +-------------------- + +New Netlink families should use ``multi-attr`` to define arrays. +Older families (e.g. ``genetlink`` control family) attempted to +define array types reusing attribute type to carry information. + +For reference the ``multi-attr`` array may look like this:: + + [ARRAY-ATTR] + [INDEX (optionally)] + [MEMBER1] + [MEMBER2] + [SOME-OTHER-ATTR] + [ARRAY-ATTR] + [INDEX (optionally)] + [MEMBER1] + [MEMBER2] + +where ``ARRAY-ATTR`` is the array entry type. + +array-nest +~~~~~~~~~~ + +``array-nest`` creates the following structure:: + + [SOME-OTHER-ATTR] + [ARRAY-ATTR] + [ENTRY] + [MEMBER1] + [MEMBER2] + [ENTRY] + [MEMBER1] + [MEMBER2] + +It wraps the entire array in an extra attribute (hence limiting its size +to 64kB). The ``ENTRY`` nests are special and have the index of the entry +as their type instead of normal attribute type. + +type-value +~~~~~~~~~~ + +``type-value`` is a construct which uses attribute types to carry +information about a single object (often used when array is dumped +entry-by-entry). + +``type-value`` can have multiple levels of nesting, for example +genetlink's policy dumps create the following structures:: + + [POLICY-IDX] + [ATTR-IDX] + [POLICY-INFO-ATTR1] + [POLICY-INFO-ATTR2] + +Where the first level of nest has the policy index as it's attribute +type, it contains a single nest which has the attribute index as its +type. Inside the attr-index nest are the policy attributes. Modern +Netlink families should have instead defined this as a flat structure, +the nesting serves no good purpose here. + +Operations +========== + +Enum (message ID) model +----------------------- + +unified +~~~~~~~ + +Modern families use the ``unified`` message ID model, which uses +a single enumeration for all messages within family. Requests and +responses share the same message ID. Notifications have separate +IDs from the same space. For example given the following list +of operations: + +.. code-block:: yaml + + - + name: a + value: 1 + do: ... + - + name: b + do: ... + - + name: c + value: 4 + notify: a + - + name: d + do: ... + +Requests and responses for operation ``a`` will have the ID of 1, +the requests and responses of ``b`` - 2 (since there is no explicit +``value`` it's previous operation ``+ 1``). Notification ``c`` will +use the ID of 4, operation ``d`` 5 etc. + +directional +~~~~~~~~~~~ + +The ``directional`` model splits the ID assignment by the direction of +the message. Messages from and to the kernel can't be confused with +each other so this conserves the ID space (at the cost of making +the programming more cumbersome). + +In this case ``value`` attribute should be specified in the ``request`` +``reply`` sections of the operations (if an operation has both ``do`` +and ``dump`` the IDs are shared, ``value`` should be set in ``do``). +For notifications the ``value`` is provided at the op level but it +only allocates a ``reply`` (i.e. a "from-kernel" ID). Let's look +at an example: + +.. code-block:: yaml + + - + name: a + do: + request: + value: 2 + attributes: ... + reply: + value: 1 + attributes: ... + - + name: b + notify: a + - + name: c + notify: a + value: 7 + - + name: d + do: ... + +In this case ``a`` will use 2 when sending the message to the kernel +and expects message with ID 1 in response. Notification ``b`` allocates +a "from-kernel" ID which is 2. ``c`` allocates "from-kernel" ID of 7. +If operation ``d`` does not set ``values`` explicitly in the spec +it will be allocated 3 for the request (``a`` is the previous operation +with a request section and the value of 2) and 8 for response (``c`` is +the previous operation in the "from-kernel" direction). + +Other quirks (todo) +=================== + +Structures +---------- + +Legacy families can define C structures both to be used as the contents +of an attribute and as a fixed message header. The plan is to define +the structs in ``definitions`` and link the appropriate attrs. + +Multi-message DO +---------------- + +New Netlink families should never respond to a DO operation with multiple +replies, with ``NLM_F_MULTI`` set. Use a filtered dump instead. + +At the spec level we can define a ``dumps`` property for the ``do``, +perhaps with values of ``combine`` and ``multi-object`` depending +on how the parsing should be implemented (parse into a single reply +vs list of objects i.e. pretty much a dump). diff --git a/Documentation/userspace-api/netlink/index.rst b/Documentation/userspace-api/netlink/index.rst index b0c21538d97d..26f3720cb3be 100644 --- a/Documentation/userspace-api/netlink/index.rst +++ b/Documentation/userspace-api/netlink/index.rst @@ -10,3 +10,9 @@ Netlink documentation for users. :maxdepth: 2 intro + intro-specs + specs + c-code-gen + genetlink-legacy + +See also :ref:`Documentation/core-api/netlink.rst <kernel_netlink>`. diff --git a/Documentation/userspace-api/netlink/intro-specs.rst b/Documentation/userspace-api/netlink/intro-specs.rst new file mode 100644 index 000000000000..a3b847eafff7 --- /dev/null +++ b/Documentation/userspace-api/netlink/intro-specs.rst @@ -0,0 +1,80 @@ +.. SPDX-License-Identifier: BSD-3-Clause + +===================================== +Using Netlink protocol specifications +===================================== + +This document is a quick starting guide for using Netlink protocol +specifications. For more detailed description of the specs see :doc:`specs`. + +Simple CLI +========== + +Kernel comes with a simple CLI tool which should be useful when +developing Netlink related code. The tool is implemented in Python +and can use a YAML specification to issue Netlink requests +to the kernel. Only Generic Netlink is supported. + +The tool is located at ``tools/net/ynl/cli.py``. It accepts +a handul of arguments, the most important ones are: + + - ``--spec`` - point to the spec file + - ``--do $name`` / ``--dump $name`` - issue request ``$name`` + - ``--json $attrs`` - provide attributes for the request + - ``--subscribe $group`` - receive notifications from ``$group`` + +YAML specs can be found under ``Documentation/netlink/specs/``. + +Example use:: + + $ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/ethtool.yaml \ + --do rings-get \ + --json '{"header":{"dev-index": 18}}' + {'header': {'dev-index': 18, 'dev-name': 'eni1np1'}, + 'rx': 0, + 'rx-jumbo': 0, + 'rx-jumbo-max': 4096, + 'rx-max': 4096, + 'rx-mini': 0, + 'rx-mini-max': 4096, + 'tx': 0, + 'tx-max': 4096, + 'tx-push': 0} + +The input arguments are parsed as JSON, while the output is only +Python-pretty-printed. This is because some Netlink types can't +be expressed as JSON directly. If such attributes are needed in +the input some hacking of the script will be necessary. + +The spec and Netlink internals are factored out as a standalone +library - it should be easy to write Python tools / tests reusing +code from ``cli.py``. + +Generating kernel code +====================== + +``tools/net/ynl/ynl-regen.sh`` scans the kernel tree in search of +auto-generated files which need to be updated. Using this tool is the easiest +way to generate / update auto-generated code. + +By default code is re-generated only if spec is newer than the source, +to force regeneration use ``-f``. + +``ynl-regen.sh`` searches for ``YNL-GEN`` in the contents of files +(note that it only scans files in the git index, that is only files +tracked by git!) For instance the ``fou_nl.c`` kernel source contains:: + + /* Documentation/netlink/specs/fou.yaml */ + /* YNL-GEN kernel source */ + +``ynl-regen.sh`` will find this marker and replace the file with +kernel source based on fou.yaml. + +The simplest way to generate a new file based on a spec is to add +the two marker lines like above to a file, add that file to git, +and run the regeneration tool. Grep the tree for ``YNL-GEN`` +to see other examples. + +The code generation itself is performed by ``tools/net/ynl/ynl-gen-c.py`` +but it takes a few arguments so calling it directly for each file +quickly becomes tedious. diff --git a/Documentation/userspace-api/netlink/specs.rst b/Documentation/userspace-api/netlink/specs.rst new file mode 100644 index 000000000000..6ffe8137cd90 --- /dev/null +++ b/Documentation/userspace-api/netlink/specs.rst @@ -0,0 +1,425 @@ +.. SPDX-License-Identifier: BSD-3-Clause + +========================================= +Netlink protocol specifications (in YAML) +========================================= + +Netlink protocol specifications are complete, machine readable descriptions of +Netlink protocols written in YAML. The goal of the specifications is to allow +separating Netlink parsing from user space logic and minimize the amount of +hand written Netlink code for each new family, command, attribute. +Netlink specs should be complete and not depend on any other spec +or C header file, making it easy to use in languages which can't include +kernel headers directly. + +Internally kernel uses the YAML specs to generate: + + - the C uAPI header + - documentation of the protocol as a ReST file + - policy tables for input attribute validation + - operation tables + +YAML specifications can be found under ``Documentation/netlink/specs/`` + +This document describes details of the schema. +See :doc:`intro-specs` for a practical starting guide. + +Compatibility levels +==================== + +There are four schema levels for Netlink specs, from the simplest used +by new families to the most complex covering all the quirks of the old ones. +Each next level inherits the attributes of the previous level, meaning that +user capable of parsing more complex ``genetlink`` schemas is also compatible +with simpler ones. The levels are: + + - ``genetlink`` - most streamlined, should be used by all new families + - ``genetlink-c`` - superset of ``genetlink`` with extra attributes allowing + customization of define and enum type and value names; this schema should + be equivalent to ``genetlink`` for all implementations which don't interact + directly with C uAPI headers + - ``genetlink-legacy`` - Generic Netlink catch all schema supporting quirks of + all old genetlink families, strange attribute formats, binary structures etc. + - ``netlink-raw`` - catch all schema supporting pre-Generic Netlink protocols + such as ``NETLINK_ROUTE`` + +The definition of the schemas (in ``jsonschema``) can be found +under ``Documentation/netlink/``. + +Schema structure +================ + +YAML schema has the following conceptual sections: + + - globals + - definitions + - attributes + - operations + - multicast groups + +Most properties in the schema accept (or in fact require) a ``doc`` +sub-property documenting the defined object. + +The following sections describe the properties of the most modern ``genetlink`` +schema. See the documentation of :doc:`genetlink-c <c-code-gen>` +for information on how C names are derived from name properties. + +genetlink +========= + +Globals +------- + +Attributes listed directly at the root level of the spec file. + +name +~~~~ + +Name of the family. Name identifies the family in a unique way, since +the Family IDs are allocated dynamically. + +version +~~~~~~~ + +Generic Netlink family version, default is 1. + +protocol +~~~~~~~~ + +The schema level, default is ``genetlink``, which is the only value +allowed for new ``genetlink`` families. + +definitions +----------- + +Array of type and constant definitions. + +name +~~~~ + +Name of the type / constant. + +type +~~~~ + +One of the following types: + + - const - a single, standalone constant + - enum - defines an integer enumeration, with values for each entry + incrementing by 1, (e.g. 0, 1, 2, 3) + - flags - defines an integer enumeration, with values for each entry + occupying a bit, starting from bit 0, (e.g. 1, 2, 4, 8) + +value +~~~~~ + +The value for the ``const``. + +value-start +~~~~~~~~~~~ + +The first value for ``enum`` and ``flags``, allows overriding the default +start value of ``0`` (for ``enum``) and starting bit (for ``flags``). +For ``flags`` ``value-start`` selects the starting bit, not the shifted value. + +Sparse enumerations are not supported. + +entries +~~~~~~~ + +Array of names of the entries for ``enum`` and ``flags``. + +header +~~~~~~ + +For C-compatible languages, header which already defines this value. +In case the definition is shared by multiple families (e.g. ``IFNAMSIZ``) +code generators for C-compatible languages may prefer to add an appropriate +include instead of rendering a new definition. + +attribute-sets +-------------- + +This property contains information about netlink attributes of the family. +All families have at least one attribute set, most have multiple. +``attribute-sets`` is an array, with each entry describing a single set. + +Note that the spec is "flattened" and is not meant to visually resemble +the format of the netlink messages (unlike certain ad-hoc documentation +formats seen in kernel comments). In the spec subordinate attribute sets +are not defined inline as a nest, but defined in a separate attribute set +referred to with a ``nested-attributes`` property of the container. + +Spec may also contain fractional sets - sets which contain a ``subset-of`` +property. Such sets describe a section of a full set, allowing narrowing down +which attributes are allowed in a nest or refining the validation criteria. +Fractional sets can only be used in nests. They are not rendered to the uAPI +in any fashion. + +name +~~~~ + +Uniquely identifies the attribute set, operations and nested attributes +refer to the sets by the ``name``. + +subset-of +~~~~~~~~~ + +Re-defines a portion of another set (a fractional set). +Allows narrowing down fields and changing validation criteria +or even types of attributes depending on the nest in which they +are contained. The ``value`` of each attribute in the fractional +set is implicitly the same as in the main set. + +attributes +~~~~~~~~~~ + +List of attributes in the set. + +Attribute properties +-------------------- + +name +~~~~ + +Identifies the attribute, unique within the set. + +type +~~~~ + +Netlink attribute type, see :ref:`attr_types`. + +.. _assign_val: + +value +~~~~~ + +Numerical attribute ID, used in serialized Netlink messages. +The ``value`` property can be skipped, in which case the attribute ID +will be the value of the previous attribute plus one (recursively) +and ``0`` for the first attribute in the attribute set. + +Note that the ``value`` of an attribute is defined only in its main set. + +enum +~~~~ + +For integer types specifies that values in the attribute belong +to an ``enum`` or ``flags`` from the ``definitions`` section. + +enum-as-flags +~~~~~~~~~~~~~ + +Treat ``enum`` as ``flags`` regardless of its type in ``definitions``. +When both ``enum`` and ``flags`` forms are needed ``definitions`` should +contain an ``enum`` and attributes which need the ``flags`` form should +use this attribute. + +nested-attributes +~~~~~~~~~~~~~~~~~ + +Identifies the attribute space for attributes nested within given attribute. +Only valid for complex attributes which may have sub-attributes. + +multi-attr (arrays) +~~~~~~~~~~~~~~~~~~~ + +Boolean property signifying that the attribute may be present multiple times. +Allowing an attribute to repeat is the recommended way of implementing arrays +(no extra nesting). + +byte-order +~~~~~~~~~~ + +For integer types specifies attribute byte order - ``little-endian`` +or ``big-endian``. + +checks +~~~~~~ + +Input validation constraints used by the kernel. User space should query +the policy of the running kernel using Generic Netlink introspection, +rather than depend on what is specified in the spec file. + +The validation policy in the kernel is formed by combining the type +definition (``type`` and ``nested-attributes``) and the ``checks``. + +operations +---------- + +This section describes messages passed between the kernel and the user space. +There are three types of entries in this section - operations, notifications +and events. + +Operations describe the most common request - response communication. User +sends a request and kernel replies. Each operation may contain any combination +of the two modes familiar to netlink users - ``do`` and ``dump``. +``do`` and ``dump`` in turn contain a combination of ``request`` and +``response`` properties. If no explicit message with attributes is passed +in a given direction (e.g. a ``dump`` which does not accept filter, or a ``do`` +of a SET operation to which the kernel responds with just the netlink error +code) ``request`` or ``response`` section can be skipped. +``request`` and ``response`` sections list the attributes allowed in a message. +The list contains only the names of attributes from a set referred +to by the ``attribute-set`` property. + +Notifications and events both refer to the asynchronous messages sent by +the kernel to members of a multicast group. The difference between the +two is that a notification shares its contents with a GET operation +(the name of the GET operation is specified in the ``notify`` property). +This arrangement is commonly used for notifications about +objects where the notification carries the full object definition. + +Events are more focused and carry only a subset of information rather than full +object state (a made up example would be a link state change event with just +the interface name and the new link state). Events contain the ``event`` +property. Events are considered less idiomatic for netlink and notifications +should be preferred. + +list +~~~~ + +The only property of ``operations`` for ``genetlink``, holds the list of +operations, notifications etc. + +Operation properties +-------------------- + +name +~~~~ + +Identifies the operation. + +value +~~~~~ + +Numerical message ID, used in serialized Netlink messages. +The same enumeration rules are applied as to +:ref:`attribute values<assign_val>`. + +attribute-set +~~~~~~~~~~~~~ + +Specifies the attribute set contained within the message. + +do +~~~ + +Specification for the ``doit`` request. Should contain ``request``, ``reply`` +or both of these properties, each holding a :ref:`attr_list`. + +dump +~~~~ + +Specification for the ``dumpit`` request. Should contain ``request``, ``reply`` +or both of these properties, each holding a :ref:`attr_list`. + +notify +~~~~~~ + +Designates the message as a notification. Contains the name of the operation +(possibly the same as the operation holding this property) which shares +the contents with the notification (``do``). + +event +~~~~~ + +Specification of attributes in the event, holds a :ref:`attr_list`. +``event`` property is mutually exclusive with ``notify``. + +mcgrp +~~~~~ + +Used with ``event`` and ``notify``, specifies which multicast group +message belongs to. + +.. _attr_list: + +Message attribute list +---------------------- + +``request``, ``reply`` and ``event`` properties have a single ``attributes`` +property which holds the list of attribute names. + +Messages can also define ``pre`` and ``post`` properties which will be rendered +as ``pre_doit`` and ``post_doit`` calls in the kernel (these properties should +be ignored by user space). + +mcast-groups +------------ + +This section lists the multicast groups of the family. + +list +~~~~ + +The only property of ``mcast-groups`` for ``genetlink``, holds the list +of groups. + +Multicast group properties +-------------------------- + +name +~~~~ + +Uniquely identifies the multicast group in the family. Similarly to +Family ID, Multicast Group ID needs to be resolved at runtime, based +on the name. + +.. _attr_types: + +Attribute types +=============== + +This section describes the attribute types supported by the ``genetlink`` +compatibility level. Refer to documentation of different levels for additional +attribute types. + +Scalar integer types +-------------------- + +Fixed-width integer types: +``u8``, ``u16``, ``u32``, ``u64``, ``s8``, ``s16``, ``s32``, ``s64``. + +Note that types smaller than 32 bit should be avoided as using them +does not save any memory in Netlink messages (due to alignment). +See :ref:`pad_type` for padding of 64 bit attributes. + +The payload of the attribute is the integer in host order unless ``byte-order`` +specifies otherwise. + +.. _pad_type: + +pad +--- + +Special attribute type used for padding attributes which require alignment +bigger than standard 4B alignment required by netlink (e.g. 64 bit integers). +There can only be a single attribute of the ``pad`` type in any attribute set +and it should be automatically used for padding when needed. + +flag +---- + +Attribute with no payload, its presence is the entire information. + +binary +------ + +Raw binary data attribute, the contents are opaque to generic code. + +string +------ + +Character string. Unless ``checks`` has ``unterminated-ok`` set to ``true`` +the string is required to be null terminated. +``max-len`` in ``checks`` indicates the longest possible string, +if not present the length of the string is unbounded. + +Note that ``max-len`` does not count the terminating character. + +nest +---- + +Attribute containing other (nested) attributes. +``nested-attributes`` specifies which attribute set is used inside. diff --git a/Documentation/userspace-api/seccomp_filter.rst b/Documentation/userspace-api/seccomp_filter.rst index d1e2b9193f09..cff0fa7f3175 100644 --- a/Documentation/userspace-api/seccomp_filter.rst +++ b/Documentation/userspace-api/seccomp_filter.rst @@ -274,7 +274,7 @@ value will be the injected file descriptor number. The notifying process can be preempted, resulting in the notification being aborted. This can be problematic when trying to take actions on behalf of the notifying process that are long-running and typically retryable (mounting a -filesytem). Alternatively, at filter installation time, the +filesystem). Alternatively, at filter installation time, the ``SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV`` flag can be set. This flag makes it such that when a user notification is received by the supervisor, the notifying process will ignore non-fatal signals until the response is sent. Signals that diff --git a/Documentation/userspace-api/sysfs-platform_profile.rst b/Documentation/userspace-api/sysfs-platform_profile.rst index c33a71263d9e..4fccde2e4563 100644 --- a/Documentation/userspace-api/sysfs-platform_profile.rst +++ b/Documentation/userspace-api/sysfs-platform_profile.rst @@ -37,6 +37,6 @@ representation onto this fixed set. If there is no good match when mapping then a new profile name may be added. Drivers which wish to introduce new profile names must: - 1. Explain why the existing profile names canot be used. + 1. Explain why the existing profile names cannot be used. 2. Add the new profile name, along with a clear description of the expected behaviour, to the sysfs-platform_profile ABI documentation. |