The DRM shmem helper includes common code useful for drivers which
allocate GEM objects as anonymous shmem. Add a Rust abstraction for
this. Drivers can choose the raw GEM implementation or the shmem layer,
depending on their needs.
Signed-off-by: Asahi Lina <lina@asahilina.net>
Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Janne Grunau <j@jananu.net>
Tested-by: Deborah Brouwer <deborah.brouwer@collabora.com>
Link: https://patch.msgid.link/20260316211646.650074-6-lyude@redhat.com
[ * DRM_GEM_SHMEM_HELPER is a tristate; when a module driver selects it,
it becomes =m. The Rust kernel crate and its C helpers are always
built into vmlinux and can't reference symbols from a module,
causing link errors.
Thus, add RUST_DRM_GEM_SHMEM_HELPER bool Kconfig that selects
DRM_GEM_SHMEM_HELPER, forcing it built-in when Rust drivers need it;
use cfg(CONFIG_RUST_DRM_GEM_SHMEM_HELPER) for the shmem module.
* Add cfg_attr(not(CONFIG_RUST_DRM_GEM_SHMEM_HELPER), expect(unused))
on pub(crate) use impl_aref_for_gem_obj and BaseObjectPrivate, so
that unused warnings are suppressed when shmem is not enabled.
* Enable const_refs_to_static (stabilized in 1.83) to prevent build
errors with older compilers.
* Use &raw const for bindings::drm_gem_shmem_vm_ops and add
#[allow(unused_unsafe, reason = "Safe since Rust 1.82.0")].
* Fix incorrect C Header path and minor spelling and formatting
issues.
* Drop shmem::Object::sg_table() as the current implementation is
unsound.
- Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Currently in order to implement AlwaysRefCounted for gem objects, we use a
blanket implementation:
unsafe impl<T: IntoGEMObject> AlwaysRefCounted for T { … }
While this technically works, it comes with the rather unfortunate downside
that attempting to create a similar blanket implementation in any other
kernel crate will now fail in a rather confusing way.
Using an example from the (not yet upstream) rust DRM KMS bindings, if we
were to add:
unsafe impl<T: RcModeObject> AlwaysRefCounted for T { … }
Then the moment that both blanket implementations are present in the same
kernel tree, compilation fails with the following:
error[E0119]: conflicting implementations of trait `types::AlwaysRefCounted`
--> rust/kernel/drm/kms.rs:504:1
|
504 | unsafe impl<T: RcModeObject> AlwaysRefCounted for T {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation
|
::: rust/kernel/drm/gem/mod.rs:97:1
|
97 | unsafe impl<T: IntoGEMObject> AlwaysRefCounted for T {
| ---------------------------------------------------- first implementation here
So, revert these changes for now. The proper fix for this is to introduce a
macro for copy/pasting the same implementation of AlwaysRefCounted around.
This reverts commit 38cb08c3fc.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20251016210955.2813186-2-lyude@redhat.com
Pull drm updates from Dave Airlie:
"cross-subsystem:
- i2c-hid: Make elan touch controllers power on after panel is
enabled
- dt bindings for STM32MP25 SoC
- pci vgaarb: use screen_info helpers
- rust pin-init updates
- add MEI driver for late binding firmware update/load
uapi:
- add ioctl for reassigning GEM handles
- provide boot_display attribute on boot-up devices
core:
- document DRM_MODE_PAGE_FLIP_EVENT
- add vendor specific recovery method to drm device wedged uevent
gem:
- Simplify gpuvm locking
ttm:
- add interface to populate buffers
sched:
- Fix race condition in trace code
atomic:
- Reallow no-op async page flips
display:
- dp: Fix command length
video:
- Improve pixel-format handling for struct screen_info
rust:
- drop Opaque<> from ioctl args
- Alloc:
- BorrowedPage type and AsPageIter traits
- Implement Vmalloc::to_page() and VmallocPageIter
- DMA/Scatterlist:
- Add dma::DataDirection and type alias for dma_addr_t
- Abstraction for struct scatterlist and sg_table
- DRM:
- simplify use of generics
- add DriverFile type alias
- drop Object::SIZE
- Rust:
- pin-init tree merge
- Various methods for AsBytes and FromBytes traits
gpuvm:
- Support madvice in Xe driver
gpusvm:
- fix hmm_pfn_to_map_order usage in gpusvm
bridge:
- Improve and fix ref counting on bridge management
- cdns-dsi: Various improvements to mode setting
- Support Solomon SSD2825 plus DT bindings
- Support Waveshare DSI2DPI plus DT bindings
- Support Content Protection property
- display-connector: Improve DP display detection
- Add support for Radxa Ra620 plus DT bindings
- adv7511: Provide SPD and HDMI infoframes
- it6505: Replace crypto_shash with sha()
- synopsys: Add support for DW DPTX Controller plus DT bindings
- adv7511: Write full Audio infoframe
- ite6263: Support vendor-specific infoframes
- simple: Add support for Realtek RTD2171 DP-to-HDMI plus DT bindings
panel:
- panel-edp: Support mt8189 Chromebooks; Support BOE NV140WUM-N64;
Support SHP LQ134Z1; Fixes
- panel-simple: Support Olimex LCD-OLinuXino-5CTS plus DT bindings
- Support Samsung AMS561RA01
- Support Hydis HV101HD1 plus DT bindings
- ilitek-ili9881c: Refactor mode setting; Add support for Bestar
BSD1218-A101KL68 LCD plus DT bindings
- lvds: Add support for Ampire AMP19201200B5TZQW-T03 to DT bindings
- edp: Add support for additonal mt8189 Chromebook panels
- lvds: Add DT bindings for EDT ETML0700Z8DHA
amdgpu:
- add CRIU support for gem objects
- RAS updates
- VCN SRAM load fixes
- EDID read fixes
- eDP ALPM support
- Documentation updates
- Rework PTE flag generation
- DCE6 fixes
- VCN devcoredump cleanup
- MMHUB client id fixes
- VCN 5.0.1 RAS support
- SMU 13.0.x updates
- Expanded PCIe DPC support
- Expanded VCN reset support
- VPE per queue reset support
- give kernel jobs unique id for tracing
- pre-populate exported buffers
- cyan skillfish updates
- make vbios build number available in sysfs
- userq updates
- HDCP updates
- support MMIO remap page as ttm pool
- JPEG parser updates
- DCE6 DC updates
- use devm for i2c buses
- GPUVM locking updates
- Drop non-DC DCE11 code
- improve fallback handling for pixel encoding
amdkfd:
- SVM/page migration fixes
- debugfs fixes
- add CRIO support for gem objects
- SVM updates
radeon:
- use dev_warn_once in CS parsers
xe:
- add madvise interface
- add DRM_IOCTL_XE_VM_QUERY_MEMORY_RANGE_ATTRS to query VMA count
and memory attributes
- drop L# bank mask reporting from media GT3 on Xe3+.
- add SLPC power_profile sysfs interface
- add configs attribs to add post/mid context-switch commands
- handle firmware reported hardware errors notifying userspace with
device wedged uevent
- use same dir structure across sysfs/debugfs
- cleanup and future proof vram region init
- add G-states and PCI link states to debugfs
- Add SRIOV support for CCS surfaces on Xe2+
- Enable SRIOV PF mode by default on supported platforms
- move flush to common code
- extended core workarounds for Xe2/3
- use DRM scheduler for delayed GT TLB invalidations
- configs improvements and allow VF device enablement
- prep work to expose mmio regions to userspace
- VF migration support added
- prepare GPU SVM for THP migration
- start fixing XE_PAGE_SIZE vs PAGE_SIZE
- add PSMI support for hw validation
- resize VF bars to max possible size according to number of VFs
- Ensure GT is in C0 during resume
- pre-populate exported buffers
- replace xe_hmm with gpusvm
- add more SVM GT stats to debugfs
- improve fake pci and WA kunnit handle for new platform testing
- Test GuC to GuC comms to add debugging
- use attribute groups to simplify sysfs registration
- add Late Binding firmware code to interact with MEI
i915:
- apply multiple JSL/EHL/Gen7/Gen6 workarounds properly
- protect against overflow in active_engine()
- Use try_cmpxchg64() in __active_lookup()
- include GuC registers in error state
- get rid of dev->struct_mutex
- iopoll: generalize read_poll_timout
- lots more display refactoring
- Reject HBR3 in any eDP Panel
- Prune modes for YUV420
- Display Wa fix, additions, and updates
- DP: Fix 2.7 Gbps link training on g4x
- DP: Adjust the idle pattern handling
- DP: Shuffle the link training code a bit
- Don't set/read the DSI C clock divider on GLK
- Enable_psr kernel parameter changes
- Type-C enabled/disconnected dp-alt sink
- Wildcat Lake enabling
- DP HDR updates
- DRAM detection
- wait PSR idle on dsb commit
- Remove FBC modulo 4 restriction for ADL-P+
- panic: refactor framebuffer allocation
habanalabs:
- debug/visibility improvements
- vmalloc-backed coherent mmap support
- HLDIO infrastructure
nova-core:
- various register!() macro improvements
- minor vbios/firmware fixes/refactoring
- advance firmware boot stages; process Booter and patch signatures
- process GSP and GSP bootloader
- Add r570.144 firmware bindings and update to it
- Move GSP boot code to own module
- Use new pin-init features to store driver's private data in a
single allocation
- Update ARef import from sync::aref
nova-drm:
- Update ARef import from sync::aref
tyr:
- initial driver skeleton for a rust driver for ARM Mali GPUs
- capable of powering up, query metadata and provide it to userspace.
msm:
- GPU and Core:
- in DT bindings describe clocks per GPU type
- GMU bandwidth voting for x1-85
- a623/a663 speedbins
- cleanup some remaining no-iommu leftovers after VM_BIND conversion
- fix GEM obj 32b size truncation
- add missing VM_BIND param validation
- IFPC for x1-85 and a750
- register xml and gen_header.py sync from mesa
- Display:
- add missing bindings for display on SC8180X
- added DisplayPort MST bindings
- conversion from round_rate() to determine_rate()
amdxdna:
- add IOCTL_AMDXDNA_GET_ARRAY
- support user space allocated buffers
- streamline PM interfaces
- Refactoring wrt. hardware contexts
- improve error reporting
nouveau:
- use GSP firmware by default
- improve error reporting
- Pre-populate exported buffers
ast:
- Clean up detection of DRAM config
exynos:
- add DSIM bridge driver support for Exynos7870
- Document Exynos7870 DSIM compatible in dt-binding
panthor:
- Print task/pid on errors
- Add support for Mali G710, G510, G310, Gx15, Gx20, Gx25
- Improve cache flushing
- Fail VM bind if BO has offset
renesas:
- convert to RUNTIME_PM_OPS
rcar-du:
- Make number of lanes configurable
- Use RUNTIME_PM_OPS
- Add support for DSI commands
rocket:
- Add driver for Rockchip NPU plus DT bindings
- Use kfree() and sizeof() correctly
- Test DMA status
rockchip:
- dsi2: Add support for RK3576 plus DT bindings
- Add support for RK3588 DPTX output
tidss:
- Use crtc_ fields for programming display mode
- Remove other drivers from aperture
pixpaper:
- Add support for Mayqueen Pixpaper plus DT bindings
v3d:
- Support querying nubmer of GPU resets for KHR_robustness
stm:
- Clean up logging
- ltdc: Add support support for STM32MP257F-EV1 plus DT bindings
sitronix:
- st7571-i2c: Add support for inverted displays and 2-bit grayscale
tidss:
- Convert to kernel's FIELD_ macros
vesadrm:
- Support 8-bit palette mode
imagination:
- Improve power management
- Add support for TH1520 GPU
- Support Risc-V architectures
v3d:
- Improve job management and locking
vkms:
- Support variants of ARGB8888, ARGB16161616, RGB565, RGB888 and P01x
- Spport YUV with 16-bit components"
* tag 'drm-next-2025-10-01' of https://gitlab.freedesktop.org/drm/kernel: (1455 commits)
drm/amd: Add name to modes from amdgpu_connector_add_common_modes()
drm/amd: Drop some common modes from amdgpu_connector_add_common_modes()
drm/amdgpu: update MODULE_PARM_DESC for freesync_video
drm/amd: Use dynamic array size declaration for amdgpu_connector_add_common_modes()
drm/amd/display: Share dce100_validate_global with DCE6-8
drm/amd/display: Share dce100_validate_bandwidth with DCE6-8
drm/amdgpu: Fix fence signaling race condition in userqueue
amd/amdkfd: enhance kfd process check in switch partition
amd/amdkfd: resolve a race in amdgpu_amdkfd_device_fini_sw
drm/amd/display: Reject modes with too high pixel clock on DCE6-10
drm/amd: Drop unnecessary check in amdgpu_connector_add_common_modes()
drm/amd/display: Only enable common modes for eDP and LVDS
drm/amdgpu: remove the redeclaration of variable i
drm/amdgpu/userq: assign an error code for invalid userq va
drm/amdgpu: revert "rework reserved VMID handling" v2
drm/amdgpu: remove leftover from enforcing isolation by VMID
drm/amdgpu: Add fallback to pipe reset if KCQ ring reset fails
accel/habanalabs: add Infineon version check
accel/habanalabs/gaudi2: read preboot status after recovering from dirty state
accel/habanalabs: add HL_GET_P_STATE passthrough type
...
We need the DRM Rust changes that went into drm-misc before the
existence of the drm-rust tree in here as well.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Now that my rust skills have been honed, I noticed that there's a lot of
generics in our gem bindings that don't actually need to be here. Currently
the hierarchy of traits in our gem bindings looks like this:
* Drivers implement:
* BaseDriverObject<T: DriverObject> (has the callbacks)
* DriverObject (has the drm::Driver type)
* Crate implements:
* IntoGEMObject for Object<T> where T: DriverObject
Handles conversion to/from raw object pointers
* BaseObject for T where T: IntoGEMObject
Provides methods common to all gem interfaces
Also of note, this leaves us with two different drm::Driver associated
types:
* DriverObject::Driver
* IntoGEMObject::Driver
I'm not entirely sure of the original intent here unfortunately (if anyone
is, please let me know!), but my guess is that the idea would be that some
objects can implement IntoGEMObject using a different ::Driver than
DriverObject - presumably to enable the usage of gem objects from different
drivers. A reasonable usecase of course.
However - if I'm not mistaken, I don't think that this is actually how
things would go in practice. Driver implementations are of course
implemented by their associated drivers, and generally drivers are not
linked to each-other when building the kernel. Which is to say that even in
a situation where we would theoretically deal with gem objects from another
driver, we still wouldn't have access to its drm::driver::Driver
implementation. It's more likely we would simply want a variant of gem
objects in such a situation that have no association with a
drm::driver::Driver type.
Taking that into consideration, we can assume the following:
* Anything that implements BaseDriverObject will implement DriverObject
In other words, all BaseDriverObjects indirectly have an associated
::Driver type - so the two traits can be combined into one with no
generics.
* Not everything that implements IntoGEMObject will have an associated
::Driver, and that's OK.
And with this, we now can do quite a bit of cleanup with the use of
generics here. As such, this commit:
* Removes the generics on BaseDriverObject
* Moves DriverObject::Driver into BaseDriverObject
* Removes DriverObject
* Removes IntoGEMObject::Driver
* Add AllocImpl::Driver, which we can use as a binding to figure out the
correct File type for BaseObject
Leaving us with a simpler trait hierarchy that now looks like this:
* Drivers implement: BaseDriverObject
* Crate implements:
* IntoGEMObject for Object<T> where T: DriverObject
* BaseObject for T where T: IntoGEMObject
Which makes the code a lot easier to understand and build on :).
Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250908185239.135849-2-lyude@redhat.com
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
