xref: /openbmc/linux/Documentation/gpu/i915.rst (revision fbe6f8f2a648584b97beeaaaeff75b795fb3c6cb)

===========================
 drm/i915 Intel GFX Driver
===========================

The drm/i915 driver supports all (with the exception of some very early
models) integrated GFX chipsets with both Intel display and rendering
blocks. This excludes a set of SoC platforms with an SGX rendering unit,
those have basic support through the gma500 drm driver.

Core Driver Infrastructure
==========================

This section covers core driver infrastructure used by both the display
and the GEM parts of the driver.

Runtime Power Management
------------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_runtime_pm.c
   :doc: runtime pm

.. kernel-doc:: drivers/gpu/drm/i915/intel_runtime_pm.c
   :internal:

.. kernel-doc:: drivers/gpu/drm/i915/intel_uncore.c
   :internal:

Interrupt Handling
------------------

.. kernel-doc:: drivers/gpu/drm/i915/i915_irq.c
   :doc: interrupt handling

.. kernel-doc:: drivers/gpu/drm/i915/i915_irq.c
   :functions: intel_irq_init intel_irq_init_hw intel_hpd_init

.. kernel-doc:: drivers/gpu/drm/i915/i915_irq.c
   :functions: intel_runtime_pm_disable_interrupts

.. kernel-doc:: drivers/gpu/drm/i915/i915_irq.c
   :functions: intel_runtime_pm_enable_interrupts

Intel GVT-g Guest Support(vGPU)
-------------------------------

.. kernel-doc:: drivers/gpu/drm/i915/i915_vgpu.c
   :doc: Intel GVT-g guest support

.. kernel-doc:: drivers/gpu/drm/i915/i915_vgpu.c
   :internal:

Intel GVT-g Host Support(vGPU device model)
-------------------------------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_gvt.c
   :doc: Intel GVT-g host support

.. kernel-doc:: drivers/gpu/drm/i915/intel_gvt.c
   :internal:

Display Hardware Handling
=========================

This section covers everything related to the display hardware including
the mode setting infrastructure, plane, sprite and cursor handling and
display, output probing and related topics.

Mode Setting Infrastructure
---------------------------

The i915 driver is thus far the only DRM driver which doesn't use the
common DRM helper code to implement mode setting sequences. Thus it has
its own tailor-made infrastructure for executing a display configuration
change.

Frontbuffer Tracking
--------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_frontbuffer.c
   :doc: frontbuffer tracking

.. kernel-doc:: drivers/gpu/drm/i915/intel_frontbuffer.h
   :internal:

.. kernel-doc:: drivers/gpu/drm/i915/intel_frontbuffer.c
   :internal:

.. kernel-doc:: drivers/gpu/drm/i915/i915_gem.c
   :functions: i915_gem_track_fb

Display FIFO Underrun Reporting
-------------------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_fifo_underrun.c
   :doc: fifo underrun handling

.. kernel-doc:: drivers/gpu/drm/i915/intel_fifo_underrun.c
   :internal:

Plane Configuration
-------------------

This section covers plane configuration and composition with the primary
plane, sprites, cursors and overlays. This includes the infrastructure
to do atomic vsync'ed updates of all this state and also tightly coupled
topics like watermark setup and computation, framebuffer compression and
panel self refresh.

Atomic Plane Helpers
--------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_atomic_plane.c
   :doc: atomic plane helpers

.. kernel-doc:: drivers/gpu/drm/i915/intel_atomic_plane.c
   :internal:

Output Probing
--------------

This section covers output probing and related infrastructure like the
hotplug interrupt storm detection and mitigation code. Note that the
i915 driver still uses most of the common DRM helper code for output
probing, so those sections fully apply.

Hotplug
-------

.. kernel-doc:: drivers/gpu/drm/i915/intel_hotplug.c
   :doc: Hotplug

.. kernel-doc:: drivers/gpu/drm/i915/intel_hotplug.c
   :internal:

High Definition Audio
---------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_audio.c
   :doc: High Definition Audio over HDMI and Display Port

.. kernel-doc:: drivers/gpu/drm/i915/intel_audio.c
   :internal:

.. kernel-doc:: include/drm/i915_component.h
   :internal:

Intel HDMI LPE Audio Support
----------------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_lpe_audio.c
   :doc: LPE Audio integration for HDMI or DP playback

.. kernel-doc:: drivers/gpu/drm/i915/intel_lpe_audio.c
   :internal:

Panel Self Refresh PSR (PSR/SRD)
--------------------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_psr.c
   :doc: Panel Self Refresh (PSR/SRD)

.. kernel-doc:: drivers/gpu/drm/i915/intel_psr.c
   :internal:

Frame Buffer Compression (FBC)
------------------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_fbc.c
   :doc: Frame Buffer Compression (FBC)

.. kernel-doc:: drivers/gpu/drm/i915/intel_fbc.c
   :internal:

Display Refresh Rate Switching (DRRS)
-------------------------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_dp.c
   :doc: Display Refresh Rate Switching (DRRS)

.. kernel-doc:: drivers/gpu/drm/i915/intel_dp.c
   :functions: intel_dp_set_drrs_state

.. kernel-doc:: drivers/gpu/drm/i915/intel_dp.c
   :functions: intel_edp_drrs_enable

.. kernel-doc:: drivers/gpu/drm/i915/intel_dp.c
   :functions: intel_edp_drrs_disable

.. kernel-doc:: drivers/gpu/drm/i915/intel_dp.c
   :functions: intel_edp_drrs_invalidate

.. kernel-doc:: drivers/gpu/drm/i915/intel_dp.c
   :functions: intel_edp_drrs_flush

.. kernel-doc:: drivers/gpu/drm/i915/intel_dp.c
   :functions: intel_dp_drrs_init

DPIO
----

.. kernel-doc:: drivers/gpu/drm/i915/intel_dpio_phy.c
   :doc: DPIO

CSR firmware support for DMC
----------------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_csr.c
   :doc: csr support for dmc

.. kernel-doc:: drivers/gpu/drm/i915/intel_csr.c
   :internal:

Video BIOS Table (VBT)
----------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_bios.c
   :doc: Video BIOS Table (VBT)

.. kernel-doc:: drivers/gpu/drm/i915/intel_bios.c
   :internal:

.. kernel-doc:: drivers/gpu/drm/i915/intel_vbt_defs.h
   :internal:

Display clocks
--------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_cdclk.c
   :doc: CDCLK / RAWCLK

.. kernel-doc:: drivers/gpu/drm/i915/intel_cdclk.c
   :internal:

Display PLLs
------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_dpll_mgr.c
   :doc: Display PLLs

.. kernel-doc:: drivers/gpu/drm/i915/intel_dpll_mgr.c
   :internal:

.. kernel-doc:: drivers/gpu/drm/i915/intel_dpll_mgr.h
   :internal:

Memory Management and Command Submission
========================================

This sections covers all things related to the GEM implementation in the
i915 driver.

Batchbuffer Parsing
-------------------

.. kernel-doc:: drivers/gpu/drm/i915/i915_cmd_parser.c
   :doc: batch buffer command parser

.. kernel-doc:: drivers/gpu/drm/i915/i915_cmd_parser.c
   :internal:

Batchbuffer Pools
-----------------

.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_batch_pool.c
   :doc: batch pool

.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_batch_pool.c
   :internal:

Logical Rings, Logical Ring Contexts and Execlists
--------------------------------------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_lrc.c
   :doc: Logical Rings, Logical Ring Contexts and Execlists

.. kernel-doc:: drivers/gpu/drm/i915/intel_lrc.c
   :internal:

Global GTT views
----------------

.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_gtt.c
   :doc: Global GTT views

.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_gtt.c
   :internal:

GTT Fences and Swizzling
------------------------

.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_fence_reg.c
   :internal:

Global GTT Fence Handling
~~~~~~~~~~~~~~~~~~~~~~~~~

.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_fence_reg.c
   :doc: fence register handling

Hardware Tiling and Swizzling Details
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_fence_reg.c
   :doc: tiling swizzling details

Object Tiling IOCTLs
--------------------

.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_tiling.c
   :internal:

.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_tiling.c
   :doc: buffer object tiling

Buffer Object Eviction
----------------------

This section documents the interface functions for evicting buffer
objects to make space available in the virtual gpu address spaces. Note
that this is mostly orthogonal to shrinking buffer objects caches, which
has the goal to make main memory (shared with the gpu through the
unified memory architecture) available.

.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_evict.c
   :internal:

Buffer Object Memory Shrinking
------------------------------

This section documents the interface function for shrinking memory usage
of buffer object caches. Shrinking is used to make main memory
available. Note that this is mostly orthogonal to evicting buffer
objects, which has the goal to make space in gpu virtual address spaces.

.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_shrinker.c
   :internal:

WOPCM
=====

WOPCM Layout
------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_wopcm.c
   :doc: WOPCM Layout

GuC
===

GuC-specific firmware loader
----------------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_guc_fw.c
   :internal:

GuC-based command submission
----------------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_guc_submission.c
   :doc: GuC-based command submission

.. kernel-doc:: drivers/gpu/drm/i915/intel_guc_submission.c
   :internal:

GuC Firmware Layout
-------------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_guc_fwif.h
   :doc: GuC Firmware Layout

GuC Address Space
-----------------

.. kernel-doc:: drivers/gpu/drm/i915/intel_guc.c
   :doc: GuC Address Space

Tracing
=======

This sections covers all things related to the tracepoints implemented
in the i915 driver.

i915_ppgtt_create and i915_ppgtt_release
----------------------------------------

.. kernel-doc:: drivers/gpu/drm/i915/i915_trace.h
   :doc: i915_ppgtt_create and i915_ppgtt_release tracepoints

i915_context_create and i915_context_free
-----------------------------------------

.. kernel-doc:: drivers/gpu/drm/i915/i915_trace.h
   :doc: i915_context_create and i915_context_free tracepoints

switch_mm
---------

.. kernel-doc:: drivers/gpu/drm/i915/i915_trace.h
   :doc: switch_mm tracepoint

Perf
====

Overview
--------
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :doc: i915 Perf Overview

Comparison with Core Perf
-------------------------
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :doc: i915 Perf History and Comparison with Core Perf

i915 Driver Entry Points
------------------------

This section covers the entrypoints exported outside of i915_perf.c to
integrate with drm/i915 and to handle the `DRM_I915_PERF_OPEN` ioctl.

.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_init
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_fini
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_register
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_unregister
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_open_ioctl
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_release
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_add_config_ioctl
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_remove_config_ioctl

i915 Perf Stream
----------------

This section covers the stream-semantics-agnostic structures and functions
for representing an i915 perf stream FD and associated file operations.

.. kernel-doc:: drivers/gpu/drm/i915/i915_drv.h
   :functions: i915_perf_stream
.. kernel-doc:: drivers/gpu/drm/i915/i915_drv.h
   :functions: i915_perf_stream_ops

.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: read_properties_unlocked
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_open_ioctl_locked
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_destroy_locked
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_read
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_ioctl
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_enable_locked
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_disable_locked
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_poll
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_perf_poll_locked

i915 Perf Observation Architecture Stream
-----------------------------------------

.. kernel-doc:: drivers/gpu/drm/i915/i915_drv.h
   :functions: i915_oa_ops

.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_oa_stream_init
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_oa_read
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_oa_stream_enable
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_oa_stream_disable
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_oa_wait_unlocked
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :functions: i915_oa_poll_wait

All i915 Perf Internals
-----------------------

This section simply includes all currently documented i915 perf internals, in
no particular order, but may include some more minor utilities or platform
specific details than found in the more high-level sections.

.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
   :internal:

Style
=====

The drm/i915 driver codebase has some style rules in addition to (and, in some
cases, deviating from) the kernel coding style.

Register macro definition style
-------------------------------

The style guide for ``i915_reg.h``.

.. kernel-doc:: drivers/gpu/drm/i915/i915_reg.h
   :doc: The i915 register macro definition style guide