Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 594 insertions, 0 deletions

diff --git a/Documentation/gpu/i915.rst b/Documentation/gpu/i915.rst
new file mode 100644
index 000000000..055df4559
--- /dev/null
+++ b/Documentation/gpu/i915.rst
@@ -0,0 +1,594 @@
+===========================
+ 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:
+
+Workarounds
+-----------
+
+.. kernel-doc:: drivers/gpu/drm/i915/intel_workarounds.c
+   :doc: Hardware workarounds
+
+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.
+
+Intel GPU Basics
+----------------
+
+An Intel GPU has multiple engines. There are several engine types.
+
+- RCS engine is for rendering 3D and performing compute, this is named
+  `I915_EXEC_RENDER` in user space.
+- BCS is a blitting (copy) engine, this is named `I915_EXEC_BLT` in user
+  space.
+- VCS is a video encode and decode engine, this is named `I915_EXEC_BSD`
+  in user space
+- VECS is video enhancement engine, this is named `I915_EXEC_VEBOX` in user
+  space.
+- The enumeration `I915_EXEC_DEFAULT` does not refer to specific engine;
+  instead it is to be used by user space to specify a default rendering
+  engine (for 3D) that may or may not be the same as RCS.
+
+The Intel GPU family is a family of integrated GPU's using Unified
+Memory Access. For having the GPU "do work", user space will feed the
+GPU batch buffers via one of the ioctls `DRM_IOCTL_I915_GEM_EXECBUFFER2`
+or `DRM_IOCTL_I915_GEM_EXECBUFFER2_WR`. Most such batchbuffers will
+instruct the GPU to perform work (for example rendering) and that work
+needs memory from which to read and memory to which to write. All memory
+is encapsulated within GEM buffer objects (usually created with the ioctl
+`DRM_IOCTL_I915_GEM_CREATE`). An ioctl providing a batchbuffer for the GPU
+to create will also list all GEM buffer objects that the batchbuffer reads
+and/or writes. For implementation details of memory management see
+`GEM BO Management Implementation Details`_.
+
+The i915 driver allows user space to create a context via the ioctl
+`DRM_IOCTL_I915_GEM_CONTEXT_CREATE` which is identified by a 32-bit
+integer. Such a context should be viewed by user-space as -loosely-
+analogous to the idea of a CPU process of an operating system. The i915
+driver guarantees that commands issued to a fixed context are to be
+executed so that writes of a previously issued command are seen by
+reads of following commands. Actions issued between different contexts
+(even if from the same file descriptor) are NOT given that guarantee
+and the only way to synchronize across contexts (even from the same
+file descriptor) is through the use of fences. At least as far back as
+Gen4, also have that a context carries with it a GPU HW context;
+the HW context is essentially (most of atleast) the state of a GPU.
+In addition to the ordering guarantees, the kernel will restore GPU
+state via HW context when commands are issued to a context, this saves
+user space the need to restore (most of atleast) the GPU state at the
+start of each batchbuffer. The non-deprecated ioctls to submit batchbuffer
+work can pass that ID (in the lower bits of drm_i915_gem_execbuffer2::rsvd1)
+to identify what context to use with the command.
+
+The GPU has its own memory management and address space. The kernel
+driver maintains the memory translation table for the GPU. For older
+GPUs (i.e. those before Gen8), there is a single global such translation
+table, a global Graphics Translation Table (GTT). For newer generation
+GPUs each context has its own translation table, called Per-Process
+Graphics Translation Table (PPGTT). Of important note, is that although
+PPGTT is named per-process it is actually per context. When user space
+submits a batchbuffer, the kernel walks the list of GEM buffer objects
+used by the batchbuffer and guarantees that not only is the memory of
+each such GEM buffer object resident but it is also present in the
+(PP)GTT. If the GEM buffer object is not yet placed in the (PP)GTT,
+then it is given an address. Two consequences of this are: the kernel
+needs to edit the batchbuffer submitted to write the correct value of
+the GPU address when a GEM BO is assigned a GPU address and the kernel
+might evict a different GEM BO from the (PP)GTT to make address room
+for another GEM BO. Consequently, the ioctls submitting a batchbuffer
+for execution also include a list of all locations within buffers that
+refer to GPU-addresses so that the kernel can edit the buffer correctly.
+This process is dubbed relocation.
+
+GEM BO Management Implementation Details
+----------------------------------------
+
+.. kernel-doc:: drivers/gpu/drm/i915/i915_vma.h
+   :doc: Virtual Memory Address
+
+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:
+
+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:
+
+User Batchbuffer Execution
+--------------------------
+
+.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_execbuffer.c
+   :doc: User command execution
+
+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
+
+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