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Diffstat (limited to 'gpu_display/protocol/linux-dmabuf-unstable-v1.xml')
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diff --git a/gpu_display/protocol/linux-dmabuf-unstable-v1.xml b/gpu_display/protocol/linux-dmabuf-unstable-v1.xml new file mode 100644 index 0000000..154afe2 --- /dev/null +++ b/gpu_display/protocol/linux-dmabuf-unstable-v1.xml @@ -0,0 +1,348 @@ +<?xml version="1.0" encoding="UTF-8"?> +<protocol name="linux_dmabuf_unstable_v1"> + + <copyright> + Copyright © 2014, 2015 Collabora, Ltd. + + Permission is hereby granted, free of charge, to any person obtaining a + copy of this software and associated documentation files (the "Software"), + to deal in the Software without restriction, including without limitation + the rights to use, copy, modify, merge, publish, distribute, sublicense, + and/or sell copies of the Software, and to permit persons to whom the + Software is furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice (including the next + paragraph) shall be included in all copies or substantial portions of the + Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + DEALINGS IN THE SOFTWARE. + </copyright> + + <interface name="zwp_linux_dmabuf_v1" version="3"> + <description summary="factory for creating dmabuf-based wl_buffers"> + Following the interfaces from: + https://www.khronos.org/registry/egl/extensions/EXT/EGL_EXT_image_dma_buf_import.txt + and the Linux DRM sub-system's AddFb2 ioctl. + + This interface offers ways to create generic dmabuf-based + wl_buffers. Immediately after a client binds to this interface, + the set of supported formats and format modifiers is sent with + 'format' and 'modifier' events. + + The following are required from clients: + + - Clients must ensure that either all data in the dma-buf is + coherent for all subsequent read access or that coherency is + correctly handled by the underlying kernel-side dma-buf + implementation. + + - Don't make any more attachments after sending the buffer to the + compositor. Making more attachments later increases the risk of + the compositor not being able to use (re-import) an existing + dmabuf-based wl_buffer. + + The underlying graphics stack must ensure the following: + + - The dmabuf file descriptors relayed to the server will stay valid + for the whole lifetime of the wl_buffer. This means the server may + at any time use those fds to import the dmabuf into any kernel + sub-system that might accept it. + + To create a wl_buffer from one or more dmabufs, a client creates a + zwp_linux_dmabuf_params_v1 object with a zwp_linux_dmabuf_v1.create_params + request. All planes required by the intended format are added with + the 'add' request. Finally, a 'create' or 'create_immed' request is + issued, which has the following outcome depending on the import success. + + The 'create' request, + - on success, triggers a 'created' event which provides the final + wl_buffer to the client. + - on failure, triggers a 'failed' event to convey that the server + cannot use the dmabufs received from the client. + + For the 'create_immed' request, + - on success, the server immediately imports the added dmabufs to + create a wl_buffer. No event is sent from the server in this case. + - on failure, the server can choose to either: + - terminate the client by raising a fatal error. + - mark the wl_buffer as failed, and send a 'failed' event to the + client. If the client uses a failed wl_buffer as an argument to any + request, the behaviour is compositor implementation-defined. + + Warning! The protocol described in this file is experimental and + backward incompatible changes may be made. Backward compatible changes + may be added together with the corresponding interface version bump. + Backward incompatible changes are done by bumping the version number in + the protocol and interface names and resetting the interface version. + Once the protocol is to be declared stable, the 'z' prefix and the + version number in the protocol and interface names are removed and the + interface version number is reset. + </description> + + <request name="destroy" type="destructor"> + <description summary="unbind the factory"> + Objects created through this interface, especially wl_buffers, will + remain valid. + </description> + </request> + + <request name="create_params"> + <description summary="create a temporary object for buffer parameters"> + This temporary object is used to collect multiple dmabuf handles into + a single batch to create a wl_buffer. It can only be used once and + should be destroyed after a 'created' or 'failed' event has been + received. + </description> + <arg name="params_id" type="new_id" interface="zwp_linux_buffer_params_v1" + summary="the new temporary"/> + </request> + + <event name="format"> + <description summary="supported buffer format"> + This event advertises one buffer format that the server supports. + All the supported formats are advertised once when the client + binds to this interface. A roundtrip after binding guarantees + that the client has received all supported formats. + + For the definition of the format codes, see the + zwp_linux_buffer_params_v1::create request. + + Warning: the 'format' event is likely to be deprecated and replaced + with the 'modifier' event introduced in zwp_linux_dmabuf_v1 + version 3, described below. Please refrain from using the information + received from this event. + </description> + <arg name="format" type="uint" summary="DRM_FORMAT code"/> + </event> + + <event name="modifier" since="3"> + <description summary="supported buffer format modifier"> + This event advertises the formats that the server supports, along with + the modifiers supported for each format. All the supported modifiers + for all the supported formats are advertised once when the client + binds to this interface. A roundtrip after binding guarantees that + the client has received all supported format-modifier pairs. + + For the definition of the format and modifier codes, see the + zwp_linux_buffer_params_v1::create request. + </description> + <arg name="format" type="uint" summary="DRM_FORMAT code"/> + <arg name="modifier_hi" type="uint" + summary="high 32 bits of layout modifier"/> + <arg name="modifier_lo" type="uint" + summary="low 32 bits of layout modifier"/> + </event> + </interface> + + <interface name="zwp_linux_buffer_params_v1" version="3"> + <description summary="parameters for creating a dmabuf-based wl_buffer"> + This temporary object is a collection of dmabufs and other + parameters that together form a single logical buffer. The temporary + object may eventually create one wl_buffer unless cancelled by + destroying it before requesting 'create'. + + Single-planar formats only require one dmabuf, however + multi-planar formats may require more than one dmabuf. For all + formats, an 'add' request must be called once per plane (even if the + underlying dmabuf fd is identical). + + You must use consecutive plane indices ('plane_idx' argument for 'add') + from zero to the number of planes used by the drm_fourcc format code. + All planes required by the format must be given exactly once, but can + be given in any order. Each plane index can be set only once. + </description> + + <enum name="error"> + <entry name="already_used" value="0" + summary="the dmabuf_batch object has already been used to create a wl_buffer"/> + <entry name="plane_idx" value="1" + summary="plane index out of bounds"/> + <entry name="plane_set" value="2" + summary="the plane index was already set"/> + <entry name="incomplete" value="3" + summary="missing or too many planes to create a buffer"/> + <entry name="invalid_format" value="4" + summary="format not supported"/> + <entry name="invalid_dimensions" value="5" + summary="invalid width or height"/> + <entry name="out_of_bounds" value="6" + summary="offset + stride * height goes out of dmabuf bounds"/> + <entry name="invalid_wl_buffer" value="7" + summary="invalid wl_buffer resulted from importing dmabufs via + the create_immed request on given buffer_params"/> + </enum> + + <request name="destroy" type="destructor"> + <description summary="delete this object, used or not"> + Cleans up the temporary data sent to the server for dmabuf-based + wl_buffer creation. + </description> + </request> + + <request name="add"> + <description summary="add a dmabuf to the temporary set"> + This request adds one dmabuf to the set in this + zwp_linux_buffer_params_v1. + + The 64-bit unsigned value combined from modifier_hi and modifier_lo + is the dmabuf layout modifier. DRM AddFB2 ioctl calls this the + fb modifier, which is defined in drm_mode.h of Linux UAPI. + This is an opaque token. Drivers use this token to express tiling, + compression, etc. driver-specific modifications to the base format + defined by the DRM fourcc code. + + This request raises the PLANE_IDX error if plane_idx is too large. + The error PLANE_SET is raised if attempting to set a plane that + was already set. + </description> + <arg name="fd" type="fd" summary="dmabuf fd"/> + <arg name="plane_idx" type="uint" summary="plane index"/> + <arg name="offset" type="uint" summary="offset in bytes"/> + <arg name="stride" type="uint" summary="stride in bytes"/> + <arg name="modifier_hi" type="uint" + summary="high 32 bits of layout modifier"/> + <arg name="modifier_lo" type="uint" + summary="low 32 bits of layout modifier"/> + </request> + + <enum name="flags"> + <entry name="y_invert" value="1" summary="contents are y-inverted"/> + <entry name="interlaced" value="2" summary="content is interlaced"/> + <entry name="bottom_first" value="4" summary="bottom field first"/> + </enum> + + <request name="create"> + <description summary="create a wl_buffer from the given dmabufs"> + This asks for creation of a wl_buffer from the added dmabuf + buffers. The wl_buffer is not created immediately but returned via + the 'created' event if the dmabuf sharing succeeds. The sharing + may fail at runtime for reasons a client cannot predict, in + which case the 'failed' event is triggered. + + The 'format' argument is a DRM_FORMAT code, as defined by the + libdrm's drm_fourcc.h. The Linux kernel's DRM sub-system is the + authoritative source on how the format codes should work. + + The 'flags' is a bitfield of the flags defined in enum "flags". + 'y_invert' means the that the image needs to be y-flipped. + + Flag 'interlaced' means that the frame in the buffer is not + progressive as usual, but interlaced. An interlaced buffer as + supported here must always contain both top and bottom fields. + The top field always begins on the first pixel row. The temporal + ordering between the two fields is top field first, unless + 'bottom_first' is specified. It is undefined whether 'bottom_first' + is ignored if 'interlaced' is not set. + + This protocol does not convey any information about field rate, + duration, or timing, other than the relative ordering between the + two fields in one buffer. A compositor may have to estimate the + intended field rate from the incoming buffer rate. It is undefined + whether the time of receiving wl_surface.commit with a new buffer + attached, applying the wl_surface state, wl_surface.frame callback + trigger, presentation, or any other point in the compositor cycle + is used to measure the frame or field times. There is no support + for detecting missed or late frames/fields/buffers either, and + there is no support whatsoever for cooperating with interlaced + compositor output. + + The composited image quality resulting from the use of interlaced + buffers is explicitly undefined. A compositor may use elaborate + hardware features or software to deinterlace and create progressive + output frames from a sequence of interlaced input buffers, or it + may produce substandard image quality. However, compositors that + cannot guarantee reasonable image quality in all cases are recommended + to just reject all interlaced buffers. + + Any argument errors, including non-positive width or height, + mismatch between the number of planes and the format, bad + format, bad offset or stride, may be indicated by fatal protocol + errors: INCOMPLETE, INVALID_FORMAT, INVALID_DIMENSIONS, + OUT_OF_BOUNDS. + + Dmabuf import errors in the server that are not obvious client + bugs are returned via the 'failed' event as non-fatal. This + allows attempting dmabuf sharing and falling back in the client + if it fails. + + This request can be sent only once in the object's lifetime, after + which the only legal request is destroy. This object should be + destroyed after issuing a 'create' request. Attempting to use this + object after issuing 'create' raises ALREADY_USED protocol error. + + It is not mandatory to issue 'create'. If a client wants to + cancel the buffer creation, it can just destroy this object. + </description> + <arg name="width" type="int" summary="base plane width in pixels"/> + <arg name="height" type="int" summary="base plane height in pixels"/> + <arg name="format" type="uint" summary="DRM_FORMAT code"/> + <arg name="flags" type="uint" summary="see enum flags"/> + </request> + + <event name="created"> + <description summary="buffer creation succeeded"> + This event indicates that the attempted buffer creation was + successful. It provides the new wl_buffer referencing the dmabuf(s). + + Upon receiving this event, the client should destroy the + zlinux_dmabuf_params object. + </description> + <arg name="buffer" type="new_id" interface="wl_buffer" + summary="the newly created wl_buffer"/> + </event> + + <event name="failed"> + <description summary="buffer creation failed"> + This event indicates that the attempted buffer creation has + failed. It usually means that one of the dmabuf constraints + has not been fulfilled. + + Upon receiving this event, the client should destroy the + zlinux_buffer_params object. + </description> + </event> + + <request name="create_immed" since="2"> + <description summary="immediately create a wl_buffer from the given + dmabufs"> + This asks for immediate creation of a wl_buffer by importing the + added dmabufs. + + In case of import success, no event is sent from the server, and the + wl_buffer is ready to be used by the client. + + Upon import failure, either of the following may happen, as seen fit + by the implementation: + - the client is terminated with one of the following fatal protocol + errors: + - INCOMPLETE, INVALID_FORMAT, INVALID_DIMENSIONS, OUT_OF_BOUNDS, + in case of argument errors such as mismatch between the number + of planes and the format, bad format, non-positive width or + height, or bad offset or stride. + - INVALID_WL_BUFFER, in case the cause for failure is unknown or + plaform specific. + - the server creates an invalid wl_buffer, marks it as failed and + sends a 'failed' event to the client. The result of using this + invalid wl_buffer as an argument in any request by the client is + defined by the compositor implementation. + + This takes the same arguments as a 'create' request, and obeys the + same restrictions. + </description> + <arg name="buffer_id" type="new_id" interface="wl_buffer" + summary="id for the newly created wl_buffer"/> + <arg name="width" type="int" summary="base plane width in pixels"/> + <arg name="height" type="int" summary="base plane height in pixels"/> + <arg name="format" type="uint" summary="DRM_FORMAT code"/> + <arg name="flags" type="uint" summary="see enum flags"/> + </request> + + </interface> + +</protocol> |