diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-03-28 17:44:52 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-03-28 17:44:52 -0700 |
commit | 0c86b42439b6c11d758b3392a21117934fef00c1 (patch) | |
tree | 6aa7071476067661867af33767cc0e1863397a04 /Documentation/gpu | |
parent | 51aad189f8e0f926c0977d180cae6a78df445f27 (diff) | |
parent | cf05922d63e2ae6a9b1b52ff5236a44c3b29f78c (diff) |
Merge tag 'drm-next-2025-03-28' of https://gitlab.freedesktop.org/drm/kernel
Pull drm updates from Dave Airlie:
"Outside of drm there are some rust patches from Danilo who maintains
that area in here, and some pieces for drm header check tests.
The major things in here are a new driver supporting the touchbar
displays on M1/M2, the nova-core stub driver which is just the vehicle
for adding rust abstractions and start developing a real driver inside
of.
xe adds support for SVM with a non-driver specific SVM core
abstraction that will hopefully be useful for other drivers, along
with support for shrinking for TTM devices. I'm sure xe and AMD
support new devices, but the pipeline depth on these things is hard to
know what they end up being in the marketplace!
uapi:
- add mediatek tiled fourcc
- add support for notifying userspace on device wedged
new driver:
- appletbdrm: support for Apple Touchbar displays on m1/m2
- nova-core: skeleton rust driver to develop nova inside off
firmware:
- add some rust firmware pieces
rust:
- add 'LocalModule' type alias
component:
- add helper to query bound status
fbdev:
- fbtft: remove access to page->index
media:
- cec: tda998x: import driver from drm
dma-buf:
- add fast path for single fence merging
tests:
- fix lockdep warnings
atomic:
- allow full modeset on connector changes
- clarify semantics of allow_modeset and drm_atomic_helper_check
- async-flip: support on arbitary planes
- writeback: fix UAF
- Document atomic-state history
format-helper:
- support ARGB8888 to ARGB4444 conversions
buddy:
- fix multi-root cleanup
ci:
- update IGT
dp:
- support extended wake timeout
- mst: fix RAD to string conversion
- increase DPCD eDP control CAP size to 5 bytes
- add DPCD eDP v1.5 definition
- add helpers for LTTPR transparent mode
panic:
- encode QR code according to Fido 2.2
scheduler:
- add parameter struct for init
- improve job peek/pop operations
- optimise drm_sched_job struct layout
ttm:
- refactor pool allocation
- add helpers for TTM shrinker
panel-orientation:
- add a bunch of new quirks
panel:
- convert panels to multi-style functions
- edp: Add support for B140UAN04.4, BOE NV140FHM-NZ, CSW MNB601LS1-3,
LG LP079QX1-SP0V, MNE007QS3-7, STA 116QHD024002, Starry
116KHD024006, Lenovo T14s Gen6 Snapdragon
- himax-hx83102: Add support for CSOT PNA957QT1-1, Kingdisplay
kd110n11-51ie, Starry 2082109qfh040022-50e
- visionox-r66451: use multi-style MIPI-DSI functions
- raydium-rm67200: Add driver for Raydium RM67200
- simple: Add support for BOE AV123Z7M-N17, BOE AV123Z7M-N17
- sony-td4353-jdi: Use MIPI-DSI multi-func interface
- summit: Add driver for Apple Summit display panel
- visionox-rm692e5: Add driver for Visionox RM692E5
bridge:
- pass full atomic state to various callbacks
- adv7511: Report correct capabilities
- it6505: Fix HDCP V compare
- snd65dsi86: fix device IDs
- nwl-dsi: set bridge type
- ti-sn65si83: add error recovery and set bridge type
- synopsys: add HDMI audio support
xe:
- support device-wedged event
- add mmap support for PCI memory barrier
- perf pmu integration and expose per-engien activity
- add EU stall sampling support
- GPU SVM and Xe SVM implementation
- use TTM shrinker
- add survivability mode to allow the driver to do firmware updates
in critical failure states
- PXP HWDRM support for MTL and LNL
- expose package/vram temps over hwmon
- enable DP tunneling
- drop mmio_ext abstraction
- Reject BO evcition if BO is bound to current VM
- Xe suballocator improvements
- re-use display vmas when possible
- add GuC Buffer Cache abstraction
- PCI ID update for Panther Lake and Battlemage
- Enable SRIOV for Panther Lake
- Refactor VRAM manager location
i915:
- enable extends wake timeout
- support device-wedged event
- Enable DP 128b/132b SST DSC
- FBC dirty rectangle support for display version 30+
- convert i915/xe to drm client setup
- Compute HDMI PLLS for rates not in fixed tables
- Allow DSB usage when PSR is enabled on LNL+
- Enable panel replay without full modeset
- Enable async flips with compressed buffers on ICL+
- support luminance based brightness via DPCD for eDP
- enable VRR enable/disable without full modeset
- allow GuC SLPC default strategies on MTL+ for performance
- lots of display refactoring in move to struct intel_display
amdgpu:
- add device wedged event
- support async page flips on overlay planes
- enable broadcast RGB drm property
- add info ioctl for virt mode
- OEM i2c support for RGB lights
- GC 11.5.2 + 11.5.3 support
- SDMA 6.1.3 support
- NBIO 7.9.1 + 7.11.2 support
- MMHUB 1.8.1 + 3.3.2 support
- DCN 3.6.0 support
- Add dynamic workload profile switching for GC 10-12
- support larger VBIOS sizes
- Mark gttsize parameters as deprecated
- Initial JPEG queue resset support
amdkfd:
- add KFD per process flags for setting precision
- sync pasid values between KGD and KFD
- improve GTT/VRAM handling for APUs
- fix user queue validation on GC7/8
- SDMA queue reset support
raedeon:
- rs400 hyperz fix
i2c:
- td998x: drop platform_data, split driver into media and bridge
ast:
- transmitter chip detection refactoring
- vbios display mode refactoring
- astdp: fix connection status and filter unsupported modes
- cursor handling refactoring
imagination:
- check job dependencies with sched helper
ivpu:
- improve command queue handling
- use workqueue for IRQ handling
- add support HW fault injection
- locking fixes
mgag200:
- add support for G200eH5
msm:
- dpu: add concurrent writeback support for DPU 10.x+
- use LTTPR helpers
- GPU:
- Fix obscure GMU suspend failure
- Expose syncobj timeline support
- Extend GPU devcoredump with pagetable info
- a623 support
- Fix a6xx gen1/gen2 indexed-register blocks in gpu snapshot /
devcoredump
- Display:
- Add cpu-cfg interconnect paths on SM8560 and SM8650
- Introduce KMS OMMU fault handler, causing devcoredump snapshot
- Fixed error pointer dereference in msm_kms_init_aspace()
- DPU:
- Fix mode_changing handling
- Add writeback support on SM6150 (QCS615)
- Fix DSC programming in 1:1:1 topology
- Reworked hardware resource allocation, moving it to the CRTC code
- Enabled support for Concurrent WriteBack (CWB) on SM8650
- Enabled CDM blocks on all relevant platforms
- Reworked debugfs interface for BW/clocks debugging
- Clear perf params before calculating bw
- Support YUV formats on writeback
- Fixed double inclusion
- Fixed writeback in YUV formats when using cloned output, Dropped
wb2_formats_rgb
- Corrected dpu_crtc_check_mode_changed and struct dpu_encoder_virt
kerneldocs
- Fixed uninitialized variable in dpu_crtc_kickoff_clone_mode()
- DSI:
- DSC-related fixes
- Rework clock programming
- DSI PHY:
- Fix 7nm (and lower) PHY programming
- Add proper DT schema definitions for DSI PHY clocks
- HDMI:
- Rework the driver, enabling the use of the HDMI Connector
framework
- Bindings:
- Added eDP PHY on SA8775P
nouveau:
- move drm_slave_encoder interface into driver
- nvkm: refactor GSP RPC
- use LTTPR helpers
mediatek:
- HDMI fixup and refinement
- add MT8188 dsc compatible
- MT8365 SoC support
panthor:
- Expose sizes of intenral BOs via fdinfo
- Fix race between reset and suspend
- Improve locking
qaic:
- Add support for AIC200
renesas:
- Fix limits in DT bindings
rockchip:
- support rk3562-mali
- rk3576: Add HDMI support
- vop2: Add new display modes on RK3588 HDMI0 up to 4K
- Don't change HDMI reference clock rate
- Fix DT bindings
- analogix_dp: add eDP support
- fix shutodnw
solomon:
- Set SPI device table to silence warnings
- Fix pixel and scanline encoding
v3d:
- handle clock
vc4:
- Use drm_exec
- Use dma-resv for wait-BO ioctl
- Remove seqno infrastructure
virtgpu:
- Support partial mappings of GEM objects
- Reserve VGA resources during initialization
- Fix UAF in virtgpu_dma_buf_free_obj()
- Add panic support
vkms:
- Switch to a managed modesetting pipeline
- Add support for ARGB8888
- fix UAf
xlnx:
- Set correct DMA segment size
- use mutex guards
- Fix error handling
- Fix docs"
* tag 'drm-next-2025-03-28' of https://gitlab.freedesktop.org/drm/kernel: (1762 commits)
drm/amd/pm: Update feature list for smu_v13_0_6
drm/amdgpu: Add parameter documentation for amdgpu_sync_fence
drm/amdgpu/discovery: optionally use fw based ip discovery
drm/amdgpu/discovery: use specific ip_discovery.bin for legacy asics
drm/amdgpu/discovery: check ip_discovery fw file available
drm/amd/pm: Remove unnecessay UQ10 to UINT conversion
drm/amd/pm: Remove unnecessay UQ10 to UINT conversion
drm/amdgpu/sdma_v4_4_2: update VM flush implementation for SDMA
drm/amdgpu: Optimize VM invalidation engine allocation and synchronize GPU TLB flush
drm/amd/amdgpu: Increase max rings to enable SDMA page ring
drm/amdgpu: Decode deferred error type in gfx aca bank parser
drm/amdgpu/gfx11: Add Cleaner Shader Support for GFX11.5 GPUs
drm/amdgpu/mes: clean up SDMA HQD loop
drm/amdgpu/mes: enable compute pipes across all MEC
drm/amdgpu/mes: drop MES 10.x leftovers
drm/amdgpu/mes: optimize compute loop handling
drm/amdgpu/sdma: guilty tracking is per instance
drm/amdgpu/sdma: fix engine reset handling
drm/amdgpu: remove invalid usage of sched.ready
drm/amdgpu: add cleaner shader trace point
...
Diffstat (limited to 'Documentation/gpu')
-rw-r--r-- | Documentation/gpu/amdgpu/amdgpu-glossary.rst | 45 | ||||
-rw-r--r-- | Documentation/gpu/amdgpu/display/dc-glossary.rst | 6 | ||||
-rw-r--r-- | Documentation/gpu/drivers.rst | 2 | ||||
-rw-r--r-- | Documentation/gpu/drm-internals.rst | 7 | ||||
-rw-r--r-- | Documentation/gpu/drm-uapi.rst | 116 | ||||
-rw-r--r-- | Documentation/gpu/drm-usage-stats.rst | 5 | ||||
-rw-r--r-- | Documentation/gpu/nouveau.rst | 29 | ||||
-rw-r--r-- | Documentation/gpu/nova/core/guidelines.rst | 24 | ||||
-rw-r--r-- | Documentation/gpu/nova/core/todo.rst | 446 | ||||
-rw-r--r-- | Documentation/gpu/nova/guidelines.rst | 69 | ||||
-rw-r--r-- | Documentation/gpu/nova/index.rst | 30 | ||||
-rw-r--r-- | Documentation/gpu/panthor.rst | 10 | ||||
-rw-r--r-- | Documentation/gpu/rfc/gpusvm.rst | 112 | ||||
-rw-r--r-- | Documentation/gpu/rfc/index.rst | 4 |
14 files changed, 892 insertions, 13 deletions
diff --git a/Documentation/gpu/amdgpu/amdgpu-glossary.rst b/Documentation/gpu/amdgpu/amdgpu-glossary.rst index 00a47ebb0b0f..1e9283e076ba 100644 --- a/Documentation/gpu/amdgpu/amdgpu-glossary.rst +++ b/Documentation/gpu/amdgpu/amdgpu-glossary.rst @@ -12,6 +12,9 @@ we have a dedicated glossary for Display Core at The number of CUs that are active on the system. The number of active CUs may be less than SE * SH * CU depending on the board configuration. + CE + Constant Engine + CP Command Processor @@ -68,6 +71,9 @@ we have a dedicated glossary for Display Core at IB Indirect Buffer + IMU + Integrated Management Unit (Power Management support) + IP Intellectual Property blocks @@ -80,6 +86,12 @@ we have a dedicated glossary for Display Core at KIQ Kernel Interface Queue + MC + Memory Controller + + ME + MicroEngine (Graphics) + MEC MicroEngine Compute @@ -92,6 +104,9 @@ we have a dedicated glossary for Display Core at MQD Memory Queue Descriptor + PFP + Pre-Fetch Parser (Graphics) + PPLib PowerPlay Library - PowerPlay is the power management component. @@ -99,7 +114,10 @@ we have a dedicated glossary for Display Core at Platform Security Processor RLC - RunList Controller + RunList Controller. This name is a remnant of past ages and doesn't have + much meaning today. It's a group of general-purpose helper engines for + the GFX block. It's involved in GFX power management and SR-IOV, among + other things. SDMA System DMA @@ -110,14 +128,35 @@ we have a dedicated glossary for Display Core at SH SHader array - SMU - System Management Unit + SMU/SMC + System Management Unit / System Management Controller + + SRLC + Save/Restore List Control + + SRLG + Save/Restore List GPM_MEM + + SRLS + Save/Restore List SRM_MEM SS Spread Spectrum + TA + Trusted Application + + TOC + Table of Contents + + UVD + Unified Video Decoder + VCE Video Compression Engine VCN Video Codec Next + + VPE + Video Processing Engine diff --git a/Documentation/gpu/amdgpu/display/dc-glossary.rst b/Documentation/gpu/amdgpu/display/dc-glossary.rst index 0b0ffd428dd2..7dc034e9e586 100644 --- a/Documentation/gpu/amdgpu/display/dc-glossary.rst +++ b/Documentation/gpu/amdgpu/display/dc-glossary.rst @@ -167,9 +167,6 @@ consider asking in the amdgfx and update this page. MALL Memory Access at Last Level - MC - Memory Controller - MPC/MPCC Multiple pipes and plane combine @@ -232,6 +229,3 @@ consider asking in the amdgfx and update this page. VRR Variable Refresh Rate - - UVD - Unified Video Decoder diff --git a/Documentation/gpu/drivers.rst b/Documentation/gpu/drivers.rst index 1f17ad0790d7..78b80be17f21 100644 --- a/Documentation/gpu/drivers.rst +++ b/Documentation/gpu/drivers.rst @@ -10,6 +10,7 @@ GPU Driver Documentation imagination/index mcde meson + nouveau pl111 tegra tve200 @@ -24,6 +25,7 @@ GPU Driver Documentation panfrost panthor zynqmp + nova/index .. only:: subproject and html diff --git a/Documentation/gpu/drm-internals.rst b/Documentation/gpu/drm-internals.rst index cb9ae282771c..94f93fd3b8a0 100644 --- a/Documentation/gpu/drm-internals.rst +++ b/Documentation/gpu/drm-internals.rst @@ -208,6 +208,13 @@ follows: ``CONFIG_VIRTIO_UML`` and ``CONFIG_UML_PCI_OVER_VIRTIO`` are not included in it because they are only required for User Mode Linux. +KUnit Coverage Rules +~~~~~~~~~~~~~~~~~~~~ + +KUnit support is gradually added to the DRM framework and helpers. There's no +general requirement for the framework and helpers to have KUnit tests at the +moment. However, patches that are affecting a function or helper already +covered by KUnit tests must provide tests if the change calls for one. Legacy Support Code =================== diff --git a/Documentation/gpu/drm-uapi.rst b/Documentation/gpu/drm-uapi.rst index b75cc9a70d1f..69f72e71a96e 100644 --- a/Documentation/gpu/drm-uapi.rst +++ b/Documentation/gpu/drm-uapi.rst @@ -371,9 +371,119 @@ Reporting causes of resets Apart from propagating the reset through the stack so apps can recover, it's really useful for driver developers to learn more about what caused the reset in -the first place. DRM devices should make use of devcoredump to store relevant -information about the reset, so this information can be added to user bug -reports. +the first place. For this, drivers can make use of devcoredump to store relevant +information about the reset and send device wedged event with ``none`` recovery +method (as explained in "Device Wedging" chapter) to notify userspace, so this +information can be collected and added to user bug reports. + +Device Wedging +============== + +Drivers can optionally make use of device wedged event (implemented as +drm_dev_wedged_event() in DRM subsystem), which notifies userspace of 'wedged' +(hanged/unusable) state of the DRM device through a uevent. This is useful +especially in cases where the device is no longer operating as expected and has +become unrecoverable from driver context. Purpose of this implementation is to +provide drivers a generic way to recover the device with the help of userspace +intervention, without taking any drastic measures (like resetting or +re-enumerating the full bus, on which the underlying physical device is sitting) +in the driver. + +A 'wedged' device is basically a device that is declared dead by the driver +after exhausting all possible attempts to recover it from driver context. The +uevent is the notification that is sent to userspace along with a hint about +what could possibly be attempted to recover the device from userspace and bring +it back to usable state. Different drivers may have different ideas of a +'wedged' device depending on hardware implementation of the underlying physical +device, and hence the vendor agnostic nature of the event. It is up to the +drivers to decide when they see the need for device recovery and how they want +to recover from the available methods. + +Driver prerequisites +-------------------- + +The driver, before opting for recovery, needs to make sure that the 'wedged' +device doesn't harm the system as a whole by taking care of the prerequisites. +Necessary actions must include disabling DMA to system memory as well as any +communication channels with other devices. Further, the driver must ensure +that all dma_fences are signalled and any device state that the core kernel +might depend on is cleaned up. All existing mmaps should be invalidated and +page faults should be redirected to a dummy page. Once the event is sent, the +device must be kept in 'wedged' state until the recovery is performed. New +accesses to the device (IOCTLs) should be rejected, preferably with an error +code that resembles the type of failure the device has encountered. This will +signify the reason for wedging, which can be reported to the application if +needed. + +Recovery +-------- + +Current implementation defines three recovery methods, out of which, drivers +can use any one, multiple or none. Method(s) of choice will be sent in the +uevent environment as ``WEDGED=<method1>[,..,<methodN>]`` in order of less to +more side-effects. If driver is unsure about recovery or method is unknown +(like soft/hard system reboot, firmware flashing, physical device replacement +or any other procedure which can't be attempted on the fly), ``WEDGED=unknown`` +will be sent instead. + +Userspace consumers can parse this event and attempt recovery as per the +following expectations. + + =============== ======================================== + Recovery method Consumer expectations + =============== ======================================== + none optional telemetry collection + rebind unbind + bind driver + bus-reset unbind + bus reset/re-enumeration + bind + unknown consumer policy + =============== ======================================== + +The only exception to this is ``WEDGED=none``, which signifies that the device +was temporarily 'wedged' at some point but was recovered from driver context +using device specific methods like reset. No explicit recovery is expected from +the consumer in this case, but it can still take additional steps like gathering +telemetry information (devcoredump, syslog). This is useful because the first +hang is usually the most critical one which can result in consequential hangs or +complete wedging. + +Consumer prerequisites +---------------------- + +It is the responsibility of the consumer to make sure that the device or its +resources are not in use by any process before attempting recovery. With IOCTLs +erroring out, all device memory should be unmapped and file descriptors should +be closed to prevent leaks or undefined behaviour. The idea here is to clear the +device of all user context beforehand and set the stage for a clean recovery. + +Example +------- + +Udev rule:: + + SUBSYSTEM=="drm", ENV{WEDGED}=="rebind", DEVPATH=="*/drm/card[0-9]", + RUN+="/path/to/rebind.sh $env{DEVPATH}" + +Recovery script:: + + #!/bin/sh + + DEVPATH=$(readlink -f /sys/$1/device) + DEVICE=$(basename $DEVPATH) + DRIVER=$(readlink -f $DEVPATH/driver) + + echo -n $DEVICE > $DRIVER/unbind + echo -n $DEVICE > $DRIVER/bind + +Customization +------------- + +Although basic recovery is possible with a simple script, consumers can define +custom policies around recovery. For example, if the driver supports multiple +recovery methods, consumers can opt for the suitable one depending on scenarios +like repeat offences or vendor specific failures. Consumers can also choose to +have the device available for debugging or telemetry collection and base their +recovery decision on the findings. This is useful especially when the driver is +unsure about recovery or method is unknown. .. _drm_driver_ioctl: diff --git a/Documentation/gpu/drm-usage-stats.rst b/Documentation/gpu/drm-usage-stats.rst index b7fc106dad99..63d6b2abe5ad 100644 --- a/Documentation/gpu/drm-usage-stats.rst +++ b/Documentation/gpu/drm-usage-stats.rst @@ -21,7 +21,10 @@ File format specification - File shall contain one key value pair per one line of text. - Colon character (`:`) must be used to delimit keys and values. -- All keys shall be prefixed with `drm-`. +- All standardised keys shall be prefixed with `drm-`. +- Driver-specific keys shall be prefixed with `driver_name-`, where + driver_name should ideally be the same as the `name` field in + `struct drm_driver`, although this is not mandatory. - Whitespace between the delimiter and first non-whitespace character shall be ignored when parsing. - Keys are not allowed to contain whitespace characters. diff --git a/Documentation/gpu/nouveau.rst b/Documentation/gpu/nouveau.rst new file mode 100644 index 000000000000..0f34131ccc27 --- /dev/null +++ b/Documentation/gpu/nouveau.rst @@ -0,0 +1,29 @@ +.. SPDX-License-Identifier: (GPL-2.0+ OR MIT) + +=============================== + drm/nouveau NVIDIA GPU Driver +=============================== + +The drm/nouveau driver provides support for a wide range of NVIDIA GPUs, +covering GeForce, Quadro, and Tesla series, from the NV04 architecture up +to the latest Turing, Ampere, Ada families. + +NVKM: NVIDIA Kernel Manager +=========================== + +The NVKM component serves as the core abstraction layer within the nouveau +driver, responsible for managing NVIDIA GPU hardware at the kernel level. +NVKM provides a unified interface for handling various GPU architectures. + +It enables resource management, power control, memory handling, and command +submission required for the proper functioning of NVIDIA GPUs under the +nouveau driver. + +NVKM plays a critical role in abstracting hardware complexities and +providing a consistent API to upper layers of the driver stack. + +GSP Support +------------------------ + +.. kernel-doc:: drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c + :doc: GSP message queue element diff --git a/Documentation/gpu/nova/core/guidelines.rst b/Documentation/gpu/nova/core/guidelines.rst new file mode 100644 index 000000000000..a389d65d7982 --- /dev/null +++ b/Documentation/gpu/nova/core/guidelines.rst @@ -0,0 +1,24 @@ +.. SPDX-License-Identifier: (GPL-2.0+ OR MIT) + +========== +Guidelines +========== + +This documents contains the guidelines for nova-core. Additionally, all common +guidelines of the Nova project do apply. + +Driver API +========== + +One main purpose of nova-core is to implement the abstraction around the +firmware interface of GSP and provide a firmware (version) independent API for +2nd level drivers, such as nova-drm or the vGPU manager VFIO driver. + +Therefore, it is not permitted to leak firmware (version) specifics, through the +driver API, to 2nd level drivers. + +Acceptance Criteria +=================== + +- To the extend possible, patches submitted to nova-core must be tested for + regressions with all 2nd level drivers. diff --git a/Documentation/gpu/nova/core/todo.rst b/Documentation/gpu/nova/core/todo.rst new file mode 100644 index 000000000000..ca08377d3b73 --- /dev/null +++ b/Documentation/gpu/nova/core/todo.rst @@ -0,0 +1,446 @@ +.. SPDX-License-Identifier: (GPL-2.0+ OR MIT) + +========= +Task List +========= + +Tasks may have the following fields: + +- ``Complexity``: Describes the required familiarity with Rust and / or the + corresponding kernel APIs or subsystems. There are four different complexities, + ``Beginner``, ``Intermediate``, ``Advanced`` and ``Expert``. +- ``Reference``: References to other tasks. +- ``Link``: Links to external resources. +- ``Contact``: The person that can be contacted for further information about + the task. + +Enablement (Rust) +================= + +Tasks that are not directly related to nova-core, but are preconditions in terms +of required APIs. + +FromPrimitive API +----------------- + +Sometimes the need arises to convert a number to a value of an enum or a +structure. + +A good example from nova-core would be the ``Chipset`` enum type, which defines +the value ``AD102``. When probing the GPU the value ``0x192`` can be read from a +certain register indication the chipset AD102. Hence, the enum value ``AD102`` +should be derived from the number ``0x192``. Currently, nova-core uses a custom +implementation (``Chipset::from_u32`` for this. + +Instead, it would be desirable to have something like the ``FromPrimitive`` +trait [1] from the num crate. + +Having this generalization also helps with implementing a generic macro that +automatically generates the corresponding mappings between a value and a number. + +| Complexity: Beginner +| Link: https://docs.rs/num/latest/num/trait.FromPrimitive.html + +Generic register abstraction +---------------------------- + +Work out how register constants and structures can be automatically generated +through generalized macros. + +Example: + +.. code-block:: rust + + register!(BOOT0, 0x0, u32, pci::Bar<SIZE>, Fields [ + MINOR_REVISION(3:0, RO), + MAJOR_REVISION(7:4, RO), + REVISION(7:0, RO), // Virtual register combining major and minor rev. + ]) + +This could expand to something like: + +.. code-block:: rust + + const BOOT0_OFFSET: usize = 0x00000000; + const BOOT0_MINOR_REVISION_SHIFT: u8 = 0; + const BOOT0_MINOR_REVISION_MASK: u32 = 0x0000000f; + const BOOT0_MAJOR_REVISION_SHIFT: u8 = 4; + const BOOT0_MAJOR_REVISION_MASK: u32 = 0x000000f0; + const BOOT0_REVISION_SHIFT: u8 = BOOT0_MINOR_REVISION_SHIFT; + const BOOT0_REVISION_MASK: u32 = BOOT0_MINOR_REVISION_MASK | BOOT0_MAJOR_REVISION_MASK; + + struct Boot0(u32); + + impl Boot0 { + #[inline] + fn read(bar: &RevocableGuard<'_, pci::Bar<SIZE>>) -> Self { + Self(bar.readl(BOOT0_OFFSET)) + } + + #[inline] + fn minor_revision(&self) -> u32 { + (self.0 & BOOT0_MINOR_REVISION_MASK) >> BOOT0_MINOR_REVISION_SHIFT + } + + #[inline] + fn major_revision(&self) -> u32 { + (self.0 & BOOT0_MAJOR_REVISION_MASK) >> BOOT0_MAJOR_REVISION_SHIFT + } + + #[inline] + fn revision(&self) -> u32 { + (self.0 & BOOT0_REVISION_MASK) >> BOOT0_REVISION_SHIFT + } + } + +Usage: + +.. code-block:: rust + + let bar = bar.try_access().ok_or(ENXIO)?; + + let boot0 = Boot0::read(&bar); + pr_info!("Revision: {}\n", boot0.revision()); + +| Complexity: Advanced + +Delay / Sleep abstractions +-------------------------- + +Rust abstractions for the kernel's delay() and sleep() functions. + +FUJITA Tomonori plans to work on abstractions for read_poll_timeout_atomic() +(and friends) [1]. + +| Complexity: Beginner +| Link: https://lore.kernel.org/netdev/20250228.080550.354359820929821928.fujita.tomonori@gmail.com/ [1] + +IRQ abstractions +---------------- + +Rust abstractions for IRQ handling. + +There is active ongoing work from Daniel Almeida [1] for the "core" abstractions +to request IRQs. + +Besides optional review and testing work, the required ``pci::Device`` code +around those core abstractions needs to be worked out. + +| Complexity: Intermediate +| Link: https://lore.kernel.org/lkml/20250122163932.46697-1-daniel.almeida@collabora.com/ [1] +| Contact: Daniel Almeida + +Page abstraction for foreign pages +---------------------------------- + +Rust abstractions for pages not created by the Rust page abstraction without +direct ownership. + +There is active onging work from Abdiel Janulgue [1] and Lina [2]. + +| Complexity: Advanced +| Link: https://lore.kernel.org/linux-mm/20241119112408.779243-1-abdiel.janulgue@gmail.com/ [1] +| Link: https://lore.kernel.org/rust-for-linux/20250202-rust-page-v1-0-e3170d7fe55e@asahilina.net/ [2] + +Scatterlist / sg_table abstractions +----------------------------------- + +Rust abstractions for scatterlist / sg_table. + +There is preceding work from Abdiel Janulgue, which hasn't made it to the +mailing list yet. + +| Complexity: Intermediate +| Contact: Abdiel Janulgue + +ELF utils +--------- + +Rust implementation of ELF header representation to retrieve section header +tables, names, and data from an ELF-formatted images. + +There is preceding work from Abdiel Janulgue, which hasn't made it to the +mailing list yet. + +| Complexity: Beginner +| Contact: Abdiel Janulgue + +PCI MISC APIs +------------- + +Extend the existing PCI device / driver abstractions by SR-IOV, config space, +capability, MSI API abstractions. + +| Complexity: Beginner + +Auxiliary bus abstractions +-------------------------- + +Rust abstraction for the auxiliary bus APIs. + +This is needed to connect nova-core to the nova-drm driver. + +| Complexity: Intermediate + +Debugfs abstractions +-------------------- + +Rust abstraction for debugfs APIs. + +| Reference: Export GSP log buffers +| Complexity: Intermediate + +Vec extensions +-------------- + +Implement ``Vec::truncate`` and ``Vec::resize``. + +Currently this is used for some experimental code to parse the vBIOS. + +| Reference vBIOS support +| Complexity: Beginner + +GPU (general) +============= + +Parse firmware headers +---------------------- + +Parse ELF headers from the firmware files loaded from the filesystem. + +| Reference: ELF utils +| Complexity: Beginner +| Contact: Abdiel Janulgue + +Build radix3 page table +----------------------- + +Build the radix3 page table to map the firmware. + +| Complexity: Intermediate +| Contact: Abdiel Janulgue + +vBIOS support +------------- + +Parse the vBIOS and probe the structures required for driver initialization. + +| Contact: Dave Airlie +| Reference: Vec extensions +| Complexity: Intermediate + +Initial Devinit support +----------------------- + +Implement BIOS Device Initialization, i.e. memory sizing, waiting, PLL +configuration. + +| Contact: Dave Airlie +| Complexity: Beginner + +Boot Falcon controller +---------------------- + +Infrastructure to load and execute falcon (sec2) firmware images; handle the +GSP falcon processor and fwsec loading. + +| Complexity: Advanced +| Contact: Dave Airlie + +GPU Timer support +----------------- + +Support for the GPU's internal timer peripheral. + +| Complexity: Beginner +| Contact: Dave Airlie + +MMU / PT management +------------------- + +Work out the architecture for MMU / page table management. + +We need to consider that nova-drm will need rather fine-grained control, +especially in terms of locking, in order to be able to implement asynchronous +Vulkan queues. + +While generally sharing the corresponding code is desirable, it needs to be +evaluated how (and if at all) sharing the corresponding code is expedient. + +| Complexity: Expert + +VRAM memory allocator +--------------------- + +Investigate options for a VRAM memory allocator. + +Some possible options: + - Rust abstractions for + - RB tree (interval tree) / drm_mm + - maple_tree + - native Rust collections + +| Complexity: Advanced + +Instance Memory +--------------- + +Implement support for instmem (bar2) used to store page tables. + +| Complexity: Intermediate +| Contact: Dave Airlie + +GPU System Processor (GSP) +========================== + +Export GSP log buffers +---------------------- + +Recent patches from Timur Tabi [1] added support to expose GSP-RM log buffers +(even after failure to probe the driver) through debugfs. + +This is also an interesting feature for nova-core, especially in the early days. + +| Link: https://lore.kernel.org/nouveau/20241030202952.694055-2-ttabi@nvidia.com/ [1] +| Reference: Debugfs abstractions +| Complexity: Intermediate + +GSP firmware abstraction +------------------------ + +The GSP-RM firmware API is unstable and may incompatibly change from version to +version, in terms of data structures and semantics. + +This problem is one of the big motivations for using Rust for nova-core, since +it turns out that Rust's procedural macro feature provides a rather elegant way +to address this issue: + +1. generate Rust structures from the C headers in a separate namespace per version +2. build abstraction structures (within a generic namespace) that implement the + firmware interfaces; annotate the differences in implementation with version + identifiers +3. use a procedural macro to generate the actual per version implementation out + of this abstraction +4. instantiate the correct version type one on runtime (can be sure that all + have the same interface because it's defined by a common trait) + +There is a PoC implementation of this pattern, in the context of the nova-core +PoC driver. + +This task aims at refining the feature and ideally generalize it, to be usable +by other drivers as well. + +| Complexity: Expert + +GSP message queue +----------------- + +Implement low level GSP message queue (command, status) for communication +between the kernel driver and GSP. + +| Complexity: Advanced +| Contact: Dave Airlie + +Bootstrap GSP +------------- + +Call the boot firmware to boot the GSP processor; execute initial control +messages. + +| Complexity: Intermediate +| Contact: Dave Airlie + +Client / Device APIs +-------------------- + +Implement the GSP message interface for client / device allocation and the +corresponding client and device allocation APIs. + +| Complexity: Intermediate +| Contact: Dave Airlie + +Bar PDE handling +---------------- + +Synchronize page table handling for BARs between the kernel driver and GSP. + +| Complexity: Beginner +| Contact: Dave Airlie + +FIFO engine +----------- + +Implement support for the FIFO engine, i.e. the corresponding GSP message +interface and provide an API for chid allocation and channel handling. + +| Complexity: Advanced +| Contact: Dave Airlie + +GR engine +--------- + +Implement support for the graphics engine, i.e. the corresponding GSP message +interface and provide an API for (golden) context creation and promotion. + +| Complexity: Advanced +| Contact: Dave Airlie + +CE engine +--------- + +Implement support for the copy engine, i.e. the corresponding GSP message +interface. + +| Complexity: Intermediate +| Contact: Dave Airlie + +VFN IRQ controller +------------------ + +Support for the VFN interrupt controller. + +| Complexity: Intermediate +| Contact: Dave Airlie + +External APIs +============= + +nova-core base API +------------------ + +Work out the common pieces of the API to connect 2nd level drivers, i.e. vGPU +manager and nova-drm. + +| Complexity: Advanced + +vGPU manager API +---------------- + +Work out the API parts required by the vGPU manager, which are not covered by +the base API. + +| Complexity: Advanced + +nova-core C API +--------------- + +Implement a C wrapper for the APIs required by the vGPU manager driver. + +| Complexity: Intermediate + +Testing +======= + +CI pipeline +----------- + +Investigate option for continuous integration testing. + +This can go from as simple as running KUnit tests over running (graphics) CTS to +booting up (multiple) guest VMs to test VFIO use-cases. + +It might also be worth to consider the introduction of a new test suite directly +sitting on top of the uAPI for more targeted testing and debugging. There may be +options for collaboration / shared code with the Mesa project. + +| Complexity: Advanced diff --git a/Documentation/gpu/nova/guidelines.rst b/Documentation/gpu/nova/guidelines.rst new file mode 100644 index 000000000000..13ab13984a18 --- /dev/null +++ b/Documentation/gpu/nova/guidelines.rst @@ -0,0 +1,69 @@ +.. SPDX-License-Identifier: (GPL-2.0+ OR MIT) + +========== +Guidelines +========== + +This document describes the general project guidelines that apply to nova-core +and nova-drm. + +Language +======== + +The Nova project uses the Rust programming language. In this context, all rules +of the Rust for Linux project as documented in +:doc:`../../rust/general-information` apply. Additionally, the following rules +apply. + +- Unless technically necessary otherwise (e.g. uAPI), any driver code is written + in Rust. + +- Unless technically necessary, unsafe Rust code must be avoided. In case of + technical necessity, unsafe code should be isolated in a separate component + providing a safe API for other driver code to use. + +Style +----- + +All rules of the Rust for Linux project as documented in +:doc:`../../rust/coding-guidelines` apply. + +For a submit checklist, please also see the `Rust for Linux Submit checklist +addendum <https://rust-for-linux.com/contributing#submit-checklist-addendum>`_. + +Documentation +============= + +The availability of proper documentation is essential in terms of scalability, +accessibility for new contributors and maintainability of a project in general, +but especially for a driver running as complex hardware as Nova is targeting. + +Hence, adding documentation of any kind is very much encouraged by the project. + +Besides that, there are some minimum requirements. + +- Every non-private structure needs at least a brief doc comment explaining the + semantical sense of the structure, as well as potential locking and lifetime + requirements. It is encouraged to have the same minimum documentation for + non-trivial private structures. + +- uAPIs must be fully documented with kernel-doc comments; additionally, the + semantical behavior must be explained including potential special or corner + cases. + +- The APIs connecting the 1st level driver (nova-core) with 2nd level drivers + must be fully documented. This includes doc comments, potential locking and + lifetime requirements, as well as example code if applicable. + +- Abbreviations must be explained when introduced; terminology must be uniquely + defined. + +- Register addresses, layouts, shift values and masks must be defined properly; + unless obvious, the semantical sense must be documented. This only applies if + the author is able to obtain the corresponding information. + +Acceptance Criteria +=================== + +- Patches must only be applied if reviewed by at least one other person on the + mailing list; this also applies for maintainers. diff --git a/Documentation/gpu/nova/index.rst b/Documentation/gpu/nova/index.rst new file mode 100644 index 000000000000..2701b3f4af35 --- /dev/null +++ b/Documentation/gpu/nova/index.rst @@ -0,0 +1,30 @@ +.. SPDX-License-Identifier: (GPL-2.0+ OR MIT) + +======================= +nova NVIDIA GPU drivers +======================= + +The nova driver project consists out of two separate drivers nova-core and +nova-drm and intends to supersede the nouveau driver for NVIDIA GPUs based on +the GPU System Processor (GSP). + +The following documents apply to both nova-core and nova-drm. + +.. toctree:: + :titlesonly: + + guidelines + +nova-core +========= + +The nova-core driver is the core driver for NVIDIA GPUs based on GSP. nova-core, +as the 1st level driver, provides an abstraction around the GPUs hard- and +firmware interfaces providing a common base for 2nd level drivers, such as the +vGPU manager VFIO driver and the nova-drm driver. + +.. toctree:: + :titlesonly: + + core/guidelines + core/todo diff --git a/Documentation/gpu/panthor.rst b/Documentation/gpu/panthor.rst index 3f8979fa2b86..7a841741278f 100644 --- a/Documentation/gpu/panthor.rst +++ b/Documentation/gpu/panthor.rst @@ -26,6 +26,8 @@ the currently possible format options: drm-cycles-panthor: 94439687187 drm-maxfreq-panthor: 1000000000 Hz drm-curfreq-panthor: 1000000000 Hz + panthor-resident-memory: 10396 KiB + panthor-active-memory: 10396 KiB drm-total-memory: 16480 KiB drm-shared-memory: 0 drm-active-memory: 16200 KiB @@ -44,3 +46,11 @@ driver by writing into the appropriate sysfs node:: Where `N` is a bit mask where cycle and timestamp sampling are respectively enabled by the first and second bits. + +Possible `panthor-*-memory` keys are: `active` and `resident`. +These values convey the sizes of the internal driver-owned shmem BO's that +aren't exposed to user-space through a DRM handle, like queue ring buffers, +sync object arrays and heap chunks. Because they are all allocated and pinned +at creation time, only `panthor-resident-memory` is necessary to tell us their +size. `panthor-active-memory` shows the size of kernel BO's associated with +VM's and groups currently being scheduled for execution by the GPU. diff --git a/Documentation/gpu/rfc/gpusvm.rst b/Documentation/gpu/rfc/gpusvm.rst new file mode 100644 index 000000000000..bcf66a8137a6 --- /dev/null +++ b/Documentation/gpu/rfc/gpusvm.rst @@ -0,0 +1,112 @@ +.. SPDX-License-Identifier: (GPL-2.0+ OR MIT) + +=============== +GPU SVM Section +=============== + +Agreed upon design principles +============================= + +* migrate_to_ram path + * Rely only on core MM concepts (migration PTEs, page references, and + page locking). + * No driver specific locks other than locks for hardware interaction in + this path. These are not required and generally a bad idea to + invent driver defined locks to seal core MM races. + * An example of a driver-specific lock causing issues occurred before + fixing do_swap_page to lock the faulting page. A driver-exclusive lock + in migrate_to_ram produced a stable livelock if enough threads read + the faulting page. + * Partial migration is supported (i.e., a subset of pages attempting to + migrate can actually migrate, with only the faulting page guaranteed + to migrate). + * Driver handles mixed migrations via retry loops rather than locking. +* Eviction + * Eviction is defined as migrating data from the GPU back to the + CPU without a virtual address to free up GPU memory. + * Only looking at physical memory data structures and locks as opposed to + looking at virtual memory data structures and locks. + * No looking at mm/vma structs or relying on those being locked. + * The rationale for the above two points is that CPU virtual addresses + can change at any moment, while the physical pages remain stable. + * GPU page table invalidation, which requires a GPU virtual address, is + handled via the notifier that has access to the GPU virtual address. +* GPU fault side + * mmap_read only used around core MM functions which require this lock + and should strive to take mmap_read lock only in GPU SVM layer. + * Big retry loop to handle all races with the mmu notifier under the gpu + pagetable locks/mmu notifier range lock/whatever we end up calling + those. + * Races (especially against concurrent eviction or migrate_to_ram) + should not be handled on the fault side by trying to hold locks; + rather, they should be handled using retry loops. One possible + exception is holding a BO's dma-resv lock during the initial migration + to VRAM, as this is a well-defined lock that can be taken underneath + the mmap_read lock. + * One possible issue with the above approach is if a driver has a strict + migration policy requiring GPU access to occur in GPU memory. + Concurrent CPU access could cause a livelock due to endless retries. + While no current user (Xe) of GPU SVM has such a policy, it is likely + to be added in the future. Ideally, this should be resolved on the + core-MM side rather than through a driver-side lock. +* Physical memory to virtual backpointer + * This does not work, as no pointers from physical memory to virtual + memory should exist. mremap() is an example of the core MM updating + the virtual address without notifying the driver of address + change rather the driver only receiving the invalidation notifier. + * The physical memory backpointer (page->zone_device_data) should remain + stable from allocation to page free. Safely updating this against a + concurrent user would be very difficult unless the page is free. +* GPU pagetable locking + * Notifier lock only protects range tree, pages valid state for a range + (rather than seqno due to wider notifiers), pagetable entries, and + mmu notifier seqno tracking, it is not a global lock to protect + against races. + * All races handled with big retry as mentioned above. + +Overview of baseline design +=========================== + +.. kernel-doc:: drivers/gpu/drm/drm_gpusvm.c + :doc: Overview + +.. kernel-doc:: drivers/gpu/drm/drm_gpusvm.c + :doc: Locking + +.. kernel-doc:: drivers/gpu/drm/drm_gpusvm.c + :doc: Migration + +.. kernel-doc:: drivers/gpu/drm/drm_gpusvm.c + :doc: Partial Unmapping of Ranges + +.. kernel-doc:: drivers/gpu/drm/drm_gpusvm.c + :doc: Examples + +Possible future design features +=============================== + +* Concurrent GPU faults + * CPU faults are concurrent so makes sense to have concurrent GPU + faults. + * Should be possible with fined grained locking in the driver GPU + fault handler. + * No expected GPU SVM changes required. +* Ranges with mixed system and device pages + * Can be added if required to drm_gpusvm_get_pages fairly easily. +* Multi-GPU support + * Work in progress and patches expected after initially landing on GPU + SVM. + * Ideally can be done with little to no changes to GPU SVM. +* Drop ranges in favor of radix tree + * May be desirable for faster notifiers. +* Compound device pages + * Nvidia, AMD, and Intel all have agreed expensive core MM functions in + migrate device layer are a performance bottleneck, having compound + device pages should help increase performance by reducing the number + of these expensive calls. +* Higher order dma mapping for migration + * 4k dma mapping adversely affects migration performance on Intel + hardware, higher order (2M) dma mapping should help here. +* Build common userptr implementation on top of GPU SVM +* Driver side madvise implementation and migration policies +* Pull in pending dma-mapping API changes from Leon / Nvidia when these land diff --git a/Documentation/gpu/rfc/index.rst b/Documentation/gpu/rfc/index.rst index 476719771eef..396e535377fb 100644 --- a/Documentation/gpu/rfc/index.rst +++ b/Documentation/gpu/rfc/index.rst @@ -18,6 +18,10 @@ host such documentation: .. toctree:: + gpusvm.rst + +.. toctree:: + i915_gem_lmem.rst .. toctree:: |