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authorLinus Torvalds <torvalds@linux-foundation.org>2020-10-15 10:46:16 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-15 10:46:16 -0700
commit93b694d096cc10994c817730d4d50288f9ae3d66 (patch)
tree5bd967686d0003f7dbbe1da49f5399cb4a92f074 /Documentation/gpu
parent726eb70e0d34dc4bc4dada71f52bba8ed638431e (diff)
parent640eee067d9aae0bb98d8706001976ff1affaf00 (diff)
downloadlinux-93b694d096cc10994c817730d4d50288f9ae3d66.tar.gz
Merge tag 'drm-next-2020-10-15' of git://anongit.freedesktop.org/drm/drm
Pull drm updates from Dave Airlie: "Not a major amount of change, the i915 trees got split into display and gt trees to better facilitate higher level review, and there's a major refactoring of i915 GEM locking to use more core kernel concepts (like ww-mutexes). msm gets per-process pagetables, older AMD SI cards get DC support, nouveau got a bump in displayport support with common code extraction from i915. Outside of drm this contains a couple of patches for hexint moduleparams which you've acked, and a virtio common code tree that you should also get via it's regular path. New driver: - Cadence MHDP8546 DisplayPort bridge driver core: - cross-driver scatterlist cleanups - devm_drm conversions - remove drm_dev_init - devm_drm_dev_alloc conversion ttm: - lots of refactoring and cleanups bridges: - chained bridge support in more drivers panel: - misc new panels scheduler: - cleanup priority levels displayport: - refactor i915 code into helpers for nouveau i915: - split into display and GT trees - WW locking refactoring in GEM - execbuf2 extension mechanism - syncobj timeline support - GEN 12 HOBL display powersaving - Rocket Lake display additions - Disable FBC on Tigerlake - Tigerlake Type-C + DP improvements - Hotplug interrupt refactoring amdgpu: - Sienna Cichlid updates - Navy Flounder updates - DCE6 (SI) support for DC - Plane rotation enabled - TMZ state info ioctl - PCIe DPC recovery support - DC interrupt handling refactor - OLED panel fixes amdkfd: - add SMI events for thermal throttling - SMI interface events ioctl update - process eviction counters radeon: - move to dma_ for allocations - expose sclk via sysfs msm: - DSI support for sm8150/sm8250 - per-process GPU pagetable support - Displayport support mediatek: - move HDMI phy driver to PHY - convert mtk-dpi to bridge API - disable mt2701 tmds tegra: - bridge support exynos: - misc cleanups vc4: - dual display cleanups ast: - cleanups gma500: - conversion to GPIOd API hisilicon: - misc reworks ingenic: - clock handling and format improvements mcde: - DSI support mgag200: - desktop g200 support mxsfb: - i.MX7 + i.MX8M - alpha plane support panfrost: - devfreq support - amlogic SoC support ps8640: - EDID from eDP retrieval tidss: - AM65xx YUV workaround virtio: - virtio-gpu exported resources rcar-du: - R8A7742, R8A774E1 and R8A77961 support - YUV planar format fixes - non-visible plane handling - VSP device reference count fix - Kconfig fix to avoid displaying disabled options in .config" * tag 'drm-next-2020-10-15' of git://anongit.freedesktop.org/drm/drm: (1494 commits) drm/ingenic: Fix bad revert drm/amdgpu: Fix invalid number of character '{' in amdgpu_acpi_init drm/amdgpu: Remove warning for virtual_display drm/amdgpu: kfd_initialized can be static drm/amd/pm: setup APU dpm clock table in SMU HW initialization drm/amdgpu: prevent spurious warning drm/amdgpu/swsmu: fix ARC build errors drm/amd/display: Fix OPTC_DATA_FORMAT programming drm/amd/display: Don't allow pstate if no support in blank drm/panfrost: increase readl_relaxed_poll_timeout values MAINTAINERS: Update entry for st7703 driver after the rename Revert "gpu/drm: ingenic: Add option to mmap GEM buffers cached" drm/amd/display: HDMI remote sink need mode validation for Linux drm/amd/display: Change to correct unit on audio rate drm/amd/display: Avoid set zero in the requested clk drm/amdgpu: align frag_end to covered address space drm/amdgpu: fix NULL pointer dereference for Renoir drm/vmwgfx: fix regression in thp code due to ttm init refactor. drm/amdgpu/swsmu: add interrupt work handler for smu11 parts drm/amdgpu/swsmu: add interrupt work function ...
Diffstat (limited to 'Documentation/gpu')
-rw-r--r--Documentation/gpu/amdgpu.rst37
-rw-r--r--Documentation/gpu/drm-uapi.rst114
-rw-r--r--Documentation/gpu/pl111.rst8
-rw-r--r--Documentation/gpu/todo.rst46
4 files changed, 189 insertions, 16 deletions
diff --git a/Documentation/gpu/amdgpu.rst b/Documentation/gpu/amdgpu.rst
index 17112352f605..57047dcb8d19 100644
--- a/Documentation/gpu/amdgpu.rst
+++ b/Documentation/gpu/amdgpu.rst
@@ -70,6 +70,15 @@ Interrupt Handling
.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
:internal:
+IP Blocks
+------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/include/amd_shared.h
+ :doc: IP Blocks
+
+.. kernel-doc:: drivers/gpu/drm/amd/include/amd_shared.h
+ :identifiers: amd_ip_block_type amd_ip_funcs
+
AMDGPU XGMI Support
===================
@@ -153,7 +162,7 @@ This section covers hwmon and power/thermal controls.
HWMON Interfaces
----------------
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
:doc: hwmon
GPU sysfs Power State Interfaces
@@ -164,48 +173,54 @@ GPU power controls are exposed via sysfs files.
power_dpm_state
~~~~~~~~~~~~~~~
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
:doc: power_dpm_state
power_dpm_force_performance_level
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
:doc: power_dpm_force_performance_level
pp_table
~~~~~~~~
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
:doc: pp_table
pp_od_clk_voltage
~~~~~~~~~~~~~~~~~
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
:doc: pp_od_clk_voltage
pp_dpm_*
~~~~~~~~
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
:doc: pp_dpm_sclk pp_dpm_mclk pp_dpm_socclk pp_dpm_fclk pp_dpm_dcefclk pp_dpm_pcie
pp_power_profile_mode
~~~~~~~~~~~~~~~~~~~~~
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
:doc: pp_power_profile_mode
*_busy_percent
~~~~~~~~~~~~~~
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
:doc: gpu_busy_percent
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
:doc: mem_busy_percent
+gpu_metrics
+~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
+ :doc: gpu_metrics
+
GPU Product Information
=======================
@@ -233,7 +248,7 @@ serial_number
unique_id
---------
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
:doc: unique_id
GPU Memory Usage Information
@@ -283,7 +298,7 @@ PCIe Accounting Information
pcie_bw
-------
-.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+.. kernel-doc:: drivers/gpu/drm/amd/pm/amdgpu_pm.c
:doc: pcie_bw
pcie_replay_count
diff --git a/Documentation/gpu/drm-uapi.rst b/Documentation/gpu/drm-uapi.rst
index 496d8fcd4da0..7dce175f6d75 100644
--- a/Documentation/gpu/drm-uapi.rst
+++ b/Documentation/gpu/drm-uapi.rst
@@ -1,3 +1,5 @@
+.. Copyright 2020 DisplayLink (UK) Ltd.
+
===================
Userland interfaces
===================
@@ -162,6 +164,116 @@ other hand, a driver requires shared state between clients which is
visible to user-space and accessible beyond open-file boundaries, they
cannot support render nodes.
+Device Hot-Unplug
+=================
+
+.. note::
+ The following is the plan. Implementation is not there yet
+ (2020 May).
+
+Graphics devices (display and/or render) may be connected via USB (e.g.
+display adapters or docking stations) or Thunderbolt (e.g. eGPU). An end
+user is able to hot-unplug this kind of devices while they are being
+used, and expects that the very least the machine does not crash. Any
+damage from hot-unplugging a DRM device needs to be limited as much as
+possible and userspace must be given the chance to handle it if it wants
+to. Ideally, unplugging a DRM device still lets a desktop continue to
+run, but that is going to need explicit support throughout the whole
+graphics stack: from kernel and userspace drivers, through display
+servers, via window system protocols, and in applications and libraries.
+
+Other scenarios that should lead to the same are: unrecoverable GPU
+crash, PCI device disappearing off the bus, or forced unbind of a driver
+from the physical device.
+
+In other words, from userspace perspective everything needs to keep on
+working more or less, until userspace stops using the disappeared DRM
+device and closes it completely. Userspace will learn of the device
+disappearance from the device removed uevent, ioctls returning ENODEV
+(or driver-specific ioctls returning driver-specific things), or open()
+returning ENXIO.
+
+Only after userspace has closed all relevant DRM device and dmabuf file
+descriptors and removed all mmaps, the DRM driver can tear down its
+instance for the device that no longer exists. If the same physical
+device somehow comes back in the mean time, it shall be a new DRM
+device.
+
+Similar to PIDs, chardev minor numbers are not recycled immediately. A
+new DRM device always picks the next free minor number compared to the
+previous one allocated, and wraps around when minor numbers are
+exhausted.
+
+The goal raises at least the following requirements for the kernel and
+drivers.
+
+Requirements for KMS UAPI
+-------------------------
+
+- KMS connectors must change their status to disconnected.
+
+- Legacy modesets and pageflips, and atomic commits, both real and
+ TEST_ONLY, and any other ioctls either fail with ENODEV or fake
+ success.
+
+- Pending non-blocking KMS operations deliver the DRM events userspace
+ is expecting. This applies also to ioctls that faked success.
+
+- open() on a device node whose underlying device has disappeared will
+ fail with ENXIO.
+
+- Attempting to create a DRM lease on a disappeared DRM device will
+ fail with ENODEV. Existing DRM leases remain and work as listed
+ above.
+
+Requirements for Render and Cross-Device UAPI
+---------------------------------------------
+
+- All GPU jobs that can no longer run must have their fences
+ force-signalled to avoid inflicting hangs on userspace.
+ The associated error code is ENODEV.
+
+- Some userspace APIs already define what should happen when the device
+ disappears (OpenGL, GL ES: `GL_KHR_robustness`_; `Vulkan`_:
+ VK_ERROR_DEVICE_LOST; etc.). DRM drivers are free to implement this
+ behaviour the way they see best, e.g. returning failures in
+ driver-specific ioctls and handling those in userspace drivers, or
+ rely on uevents, and so on.
+
+- dmabuf which point to memory that has disappeared will either fail to
+ import with ENODEV or continue to be successfully imported if it would
+ have succeeded before the disappearance. See also about memory maps
+ below for already imported dmabufs.
+
+- Attempting to import a dmabuf to a disappeared device will either fail
+ with ENODEV or succeed if it would have succeeded without the
+ disappearance.
+
+- open() on a device node whose underlying device has disappeared will
+ fail with ENXIO.
+
+.. _GL_KHR_robustness: https://www.khronos.org/registry/OpenGL/extensions/KHR/KHR_robustness.txt
+.. _Vulkan: https://www.khronos.org/vulkan/
+
+Requirements for Memory Maps
+----------------------------
+
+Memory maps have further requirements that apply to both existing maps
+and maps created after the device has disappeared. If the underlying
+memory disappears, the map is created or modified such that reads and
+writes will still complete successfully but the result is undefined.
+This applies to both userspace mmap()'d memory and memory pointed to by
+dmabuf which might be mapped to other devices (cross-device dmabuf
+imports).
+
+Raising SIGBUS is not an option, because userspace cannot realistically
+handle it. Signal handlers are global, which makes them extremely
+difficult to use correctly from libraries like those that Mesa produces.
+Signal handlers are not composable, you can't have different handlers
+for GPU1 and GPU2 from different vendors, and a third handler for
+mmapped regular files. Threads cause additional pain with signal
+handling as well.
+
.. _drm_driver_ioctl:
IOCTL Support on Device Nodes
@@ -199,7 +311,7 @@ EPERM/EACCES:
difference between EACCES and EPERM.
ENODEV:
- The device is not (yet) present or fully initialized.
+ The device is not present anymore or is not yet fully initialized.
EOPNOTSUPP:
Feature (like PRIME, modesetting, GEM) is not supported by the driver.
diff --git a/Documentation/gpu/pl111.rst b/Documentation/gpu/pl111.rst
index 9b03736d33dd..6d9a1b59a545 100644
--- a/Documentation/gpu/pl111.rst
+++ b/Documentation/gpu/pl111.rst
@@ -1,6 +1,6 @@
-==========================================
- drm/pl111 ARM PrimeCell PL111 CLCD Driver
-==========================================
+====================================================
+ drm/pl111 ARM PrimeCell PL110 and PL111 CLCD Driver
+====================================================
.. kernel-doc:: drivers/gpu/drm/pl111/pl111_drv.c
- :doc: ARM PrimeCell PL111 CLCD Driver
+ :doc: ARM PrimeCell PL110 and PL111 CLCD Driver
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 7969f106877d..b0ea17da8ff6 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -403,6 +403,52 @@ Contact: Emil Velikov, respective driver maintainers
Level: Intermediate
+Plumb drm_atomic_state all over
+-------------------------------
+
+Currently various atomic functions take just a single or a handful of
+object states (eg. plane state). While that single object state can
+suffice for some simple cases, we often have to dig out additional
+object states for dealing with various dependencies between the individual
+objects or the hardware they represent. The process of digging out the
+additional states is rather non-intuitive and error prone.
+
+To fix that most functions should rather take the overall
+drm_atomic_state as one of their parameters. The other parameters
+would generally be the object(s) we mainly want to interact with.
+
+For example, instead of
+
+.. code-block:: c
+
+ int (*atomic_check)(struct drm_plane *plane, struct drm_plane_state *state);
+
+we would have something like
+
+.. code-block:: c
+
+ int (*atomic_check)(struct drm_plane *plane, struct drm_atomic_state *state);
+
+The implementation can then trivially gain access to any required object
+state(s) via drm_atomic_get_plane_state(), drm_atomic_get_new_plane_state(),
+drm_atomic_get_old_plane_state(), and their equivalents for
+other object types.
+
+Additionally many drivers currently access the object->state pointer
+directly in their commit functions. That is not going to work if we
+eg. want to allow deeper commit pipelines as those pointers could
+then point to the states corresponding to a future commit instead of
+the current commit we're trying to process. Also non-blocking commits
+execute locklessly so there are serious concerns with dereferencing
+the object->state pointers without holding the locks that protect them.
+Use of drm_atomic_get_new_plane_state(), drm_atomic_get_old_plane_state(),
+etc. avoids these problems as well since they relate to a specific
+commit via the passed in drm_atomic_state.
+
+Contact: Ville Syrjälä, Daniel Vetter
+
+Level: Intermediate
+
Core refactorings
=================