drm/xe: Introduce a new DRM driver for Intel GPUs

Xe, is a new driver for Intel GPUs that supports both integrated and
discrete platforms starting with Tiger Lake (first Intel Xe Architecture).

The code is at a stage where it is already functional and has experimental
support for multiple platforms starting from Tiger Lake, with initial
support implemented in Mesa (for Iris and Anv, our OpenGL and Vulkan
drivers), as well as in NEO (for OpenCL and Level0).

The new Xe driver leverages a lot from i915.

As for display, the intent is to share the display code with the i915
driver so that there is maximum reuse there. But it is not added
in this patch.

This initial work is a collaboration of many people and unfortunately
the big squashed patch won't fully honor the proper credits. But let's
get some git quick stats so we can at least try to preserve some of the
credits:

Co-developed-by: Matthew Brost <matthew.brost@intel.com>
Co-developed-by: Matthew Auld <matthew.auld@intel.com>
Co-developed-by: Matt Roper <matthew.d.roper@intel.com>
Co-developed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Co-developed-by: Francois Dugast <francois.dugast@intel.com>
Co-developed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Co-developed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Co-developed-by: Philippe Lecluse <philippe.lecluse@intel.com>
Co-developed-by: Nirmoy Das <nirmoy.das@intel.com>
Co-developed-by: Jani Nikula <jani.nikula@intel.com>
Co-developed-by: José Roberto de Souza <jose.souza@intel.com>
Co-developed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Co-developed-by: Dave Airlie <airlied@redhat.com>
Co-developed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Co-developed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Co-developed-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>

drm/imagination: Add driver documentation

Add documentation for the UAPI.

Changes since v5:
- Remove obsolete VM documentation

Co-developed-by: Matt Coster <matt.coster@imgtec.com>
Signed-off-by: Matt Coster <matt.coster@imgtec.com>
Co-developed-by: Donald Robson <donald.robson@imgtec.com>
Signed-off-by: Donald Robson <donald.robson@imgtec.com>
Signed-off-by: Sarah Walker <sarah.walker@imgtec.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/76a7b18cfbe93066efcee3311ae795176ce7c65d.1700668843.git.donald.robson@imgtec.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>

Documentation/gpu: fix Panfrost documentation build warnings

Fix issues revealed by `make htmldocs` after adding Panfrost DRM
documentation file.

Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Fixes: f11b0417eec2 ("drm/panfrost: Add fdinfo support GPU load metrics")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310030917.Txzlpoeq-lkp@intel.com
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231005141239.132783-1-adrian.larumbe@collabora.com

Documentation/gpu: Reorganize DC documentation

Display core documentation is not well organized, and it is hard to find
information due to the lack of sections. This commit reorganizes the
documentation layout, and it is preparation work for future changes.

Changes since V1:
- Christian: Group amdgpu documentation together.
- Daniel: Drop redundant amdgpu prefix.
- Jani: Create index pages.
- Yann: Mirror display folder in the documentation.

Reviewed-by: Yann Dirson <ydirson@free.fr>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/tinydrm: Move mipi-dbi

This moves mipi-dbi to be a core helper with the name drm_mipi_dbi.

Fixup include's in drivers.
Move the docs entry and delete tinydrm.rst.
Delete the last tinydrm todo entry.

v2: Make DRM_MIPI_DBI tristate to enable it being built as a module.

Cc: Eric Anholt <eric@anholt.net>
Cc: David Lechner <david@lechnology.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: David Lechner <david@lechnology.com>
Acked-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190722104312.16184-9-noralf@tronnes.org

drm/mcde: Add new driver for ST-Ericsson MCDE

This adds a new DRM driver for the ST-Ericsson Multi Channel
Display Engine, MCDE display controller.

This hardware has three independent DSI hosts and can composit
and display several memory buffers onto an LCD display. It
was developed for several years inside of ST-Ericsson and
shipped with a few million mobile phones from Sony and Samsung,
as well as with the Snowball community development board.

The driver is currently pretty rudimentary but supports a
simple framebuffer so we can get penguins and graphics when
using these SoCs.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190524092019.19355-1-linus.walleij@linaro.org

drm/doc: Add initial komeda driver documentation

v2: Some editing changes according to Randy Dunlap's comments

Signed-off-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>

drm/afbc: Add AFBC modifier usage documentation

AFBC is a flexible, proprietary, lossless compression protocol and
format, with a number of defined DRM format modifiers. To facilitate
consistency and compatibility between different AFBC producers and
consumers, document the expectations for usage of the AFBC DRM format
modifiers in a new .rst chapter.

Signed-off-by: Brian Starkey <brian.starkey@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
[Updated MAINTAINERS entry to show that "Mali DP Maintainers" is
actually a mailing list and added an SPDX-License-Identifier to
the documentation]
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>

drm/amd/display: Initial documentation for AMDgpu DC

[Why]
Documentation is helpful for the community to understand our code.
This change does some high-level documentation of some DM interfaces
with DRM, and the amdgpu base driver.

[How]
An entry for AMDgpu DC has been added to Documentation/gpu/drivers.rst
TOC. amdgpu-dc.rst is created to pull in inline doc-strings, which:
- Provides an overview for "What is DM?"
- Documents AMDgpu DM lifecyle
- Documents IRQ management
- Documents atomic_check and commit_tail interfaces

Signed-off-by: Leo Li <sunpeng.li@amd.com>
Reviewed-by: David Francis <David.Francis@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/vkms: Add kerneldoc entry

Add an initial kerneldoc entry for vkms with a todo list.

Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
[danvet: Keep the todo.rst entry to point at the vkms docs instead.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907174136.GA2648@haneenDRM

drm/doc: Add initial amdgpu driver documentation

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/v3d: Introduce a new DRM driver for Broadcom V3D V3.x+

This driver will be used to support Mesa on the Broadcom 7268 and 7278
platforms.

V3D 3.3 introduces an MMU, which means we no longer need CMA or vc4's
complicated CL/shader validation scheme. This massively changes the
GEM behavior, so I've forked off to a new driver.

v2: Mark SUBMIT_CL as needing DRM_AUTH. coccinelle fixes from kbuild
test robot. Drop personal git link from MAINTAINERS. Don't
double-map dma-buf imported BOs. Add kerneldoc about needing MMU
eviction. Drop prime vmap/unmap stubs. Delay mmap offset setup
to mmap time. Use drm_dev_init instead of _alloc. Use
ktime_get() for wait_bo timeouts. Drop drm_can_sleep() usage,
since we don't modeset. Switch page tables back to WC (debug
change to coherent had slipped in). Switch
drm_gem_object_unreference_unlocked() to
drm_gem_object_put_unlocked(). Simplify overflow mem handling by
not sharing overflow mem between jobs.
v3: no changes
v4: align submit_cl to 64 bits (review by airlied), check zero flags in
other ioctls.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v4)
Acked-by: Dave Airlie <airlied@linux.ie> (v3, requested submit_cl change)
Link: https://patchwork.freedesktop.org/patch/msgid/20180430181058.30181-3-eric@anholt.net

drm/xen-front: Add support for Xen PV display frontend

Add support for Xen para-virtualized frontend display driver.
Accompanying backend [1] is implemented as a user-space application
and its helper library [2], capable of running as a Weston client
or DRM master.
Configuration of both backend and frontend is done via
Xen guest domain configuration options [3].

Driver limitations:
1. Only primary plane without additional properties is supported.
2. Only one video mode supported which resolution is configured
via XenStore.
3. All CRTCs operate at fixed frequency of 60Hz.

1. Implement Xen bus state machine for the frontend driver according to
the state diagram and recovery flow from display para-virtualized
protocol: xen/interface/io/displif.h.

2. Read configuration values from Xen store according
to xen/interface/io/displif.h protocol:
- read connector(s) configuration
- read buffer allocation mode (backend/frontend)

3. Handle Xen event channels:
- create for all configured connectors and publish
corresponding ring references and event channels in Xen store,
so backend can connect
- implement event channels interrupt handlers
- create and destroy event channels with respect to Xen bus state

4. Implement shared buffer handling according to the
para-virtualized display device protocol at xen/interface/io/displif.h:
- handle page directories according to displif protocol:
- allocate and share page directories
- grant references to the required set of pages for the
page directory
- allocate xen balllooned pages via Xen balloon driver
with alloc_xenballooned_pages/free_xenballooned_pages
- grant references to the required set of pages for the
shared buffer itself
- implement pages map/unmap for the buffers allocated by the
backend (gnttab_map_refs/gnttab_unmap_refs)

5. Implement kernel modesetiing/connector handling using
DRM simple KMS helper pipeline:

- implement KMS part of the driver with the help of DRM
simple pipepline helper which is possible due to the fact
that the para-virtualized driver only supports a single
(primary) plane:
- initialize connectors according to XenStore configuration
- handle frame done events from the backend
- create and destroy frame buffers and propagate those
to the backend
- propagate set/reset mode configuration to the backend on display
enable/disable callbacks
- send page flip request to the backend and implement logic for
reporting backend IO errors on prepare fb callback

- implement virtual connector handling:
- support only pixel formats suitable for single plane modes
- make sure the connector is always connected
- support a single video mode as per para-virtualized driver
configuration

6. Implement GEM handling depending on driver mode of operation:
depending on the requirements for the para-virtualized environment,
namely requirements dictated by the accompanying DRM/(v)GPU drivers
running in both host and guest environments, number of operating
modes of para-virtualized display driver are supported:
- display buffers can be allocated by either
frontend driver or backend
- display buffers can be allocated to be contiguous
in memory or not

Note! Frontend driver itself has no dependency on contiguous memory for
its operation.

6.1. Buffers allocated by the frontend driver.

The below modes of operation are configured at compile-time via
frontend driver's kernel configuration.

6.1.1. Front driver configured to use GEM CMA helpers
This use-case is useful when used with accompanying DRM/vGPU driver
in guest domain which was designed to only work with contiguous
buffers, e.g. DRM driver based on GEM CMA helpers: such drivers can
only import contiguous PRIME buffers, thus requiring frontend driver
to provide such. In order to implement this mode of operation
para-virtualized frontend driver can be configured to use
GEM CMA helpers.

6.1.2. Front driver doesn't use GEM CMA
If accompanying drivers can cope with non-contiguous memory then, to
lower pressure on CMA subsystem of the kernel, driver can allocate
buffers from system memory.

Note! If used with accompanying DRM/(v)GPU drivers this mode of operation
may require IOMMU support on the platform, so accompanying DRM/vGPU
hardware can still reach display buffer memory while importing PRIME
buffers from the frontend driver.

6.2. Buffers allocated by the backend

This mode of operation is run-time configured via guest domain
configuration through XenStore entries.

For systems which do not provide IOMMU support, but having specific
requirements for display buffers it is possible to allocate such buffers
at backend side and share those with the frontend.
For example, if host domain is 1:1 mapped and has DRM/GPU hardware
expecting physically contiguous memory, this allows implementing
zero-copying use-cases.

Note, while using this scenario the following should be considered:
a) If guest domain dies then pages/grants received from the backend
cannot be claimed back
b) Misbehaving guest may send too many requests to the
backend exhausting its grant references and memory
(consider this from security POV).

Note! Configuration options 1.1 (contiguous display buffers) and 2
(backend allocated buffers) are not supported at the same time.

7. Handle communication with the backend:
- send requests and wait for the responses according
to the displif protocol
- serialize access to the communication channel
- time-out used for backend communication is set to 3000 ms
- manage display buffers shared with the backend

[1] https://github.com/xen-troops/displ_be
[2] https://github.com/xen-troops/libxenbe
[3] https://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/man/xl.cfg.pod.5.in;h=a699367779e2ae1212ff8f638eff0206ec1a1cc9;hb=refs/heads/master#l1257

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180403112317.28751-2-andr2000@gmail.com

drm/doc: Put all driver docs into a separate chapter

We have quite a few driver docs now, which is great, but having them
all in the top-level gpu documentation chapter makes it harder to spot
the core/shared bits.

Stuff them into a separate chapter and ecourage people to add even
more!

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180316075926.13584-1-daniel.vetter@ffwll.ch