Merge tag 'drm-rust-next-2026-03-30' of https://gitlab.freedesktop.org/drm/rust/kernel into drm-next

DRM Rust changes for v7.1-rc1

- DMA:
  - Rework the DMA coherent API: introduce Coherent<T> as a generalized
    container for arbitrary types, replacing the slice-only
    CoherentAllocation<T>. Add CoherentBox for memory initialization
    before exposing a buffer to hardware (converting to Coherent when
    ready), and CoherentHandle for allocations without kernel mapping.

  - Add Coherent::init() / init_with_attrs() for one-shot initialization
    via pin-init, and from-slice constructors for both Coherent and
    CoherentBox

  - Add uaccess write_dma() for copying from DMA buffers to userspace
    and BinaryWriter support for Coherent<T>

- DRM:
  - Add GPU buddy allocator abstraction

  - Add DRM shmem GEM helper abstraction

  - Allow drm::Device to dispatch work and delayed work items to driver
    private data

  - Add impl_aref_for_gem_obj!() macro to reduce GEM refcount
    boilerplate, and introduce DriverObject::Args for constructor
    context

  - Add dma_resv_lock helper and raw_dma_resv() accessor on GEM objects

  - Clean up imports across the DRM module

- I/O:
  - Merged via a signed tag from the driver-core tree: register!() macro
    and I/O infrastructure improvements (IoCapable refactor, RelaxedMmio
    wrapper, IoLoc trait, generic accessors, write_reg /
    LocatedRegister)

- Nova (Core):
  - Fix and harden the GSP command queue: correct write pointer
    advancing, empty slot handling, and ring buffer indexing; add mutex
    locking and make Cmdq a pinned type; distinguish wait vs no-wait
    commands

  - Add support for large RPCs via continuation records, splitting
    oversized commands across multiple queue slots

  - Simplify GSP sequencer and message handling code: remove unused
    trait and Display impls, derive Debug and Zeroable where applicable,
    warn on unconsumed message data

  - Refactor Falcon firmware handling: create DMA objects lazily, add
    PIO upload support, and use the Generic Bootloader to boot FWSEC on
    Turing

  - Convert all register definitions (PMC, PBUS, PFB, GC6, FUSE, PDISP,
    Falcon) to the kernel register!() macro; add bounded_enum macro to
    define enums usable as register fields

  - Migrate all DMA usage to the new Coherent, CoherentBox, and
    CoherentHandle APIs

  - Harden firmware parsing with checked arithmetic throughout FWSEC,
    Booter, RISC-V parsing paths

  - Add debugfs support for reading GSP-RM log buffers; replace
    module_pci_driver!() with explicit module init to support
    module-level debugfs setup

  - Fix auxiliary device registration for multi-GPU systems

  - Various cleanups: import style, firmware parsing refactoring,
    framebuffer size logging

- Rust:
  - Add interop::list module providing a C linked list interface

  - Extend num::Bounded with shift operations, into_bool(), and const
    get() to support register bitfield manipulation

  - Enable the generic_arg_infer Rust feature and add EMSGSIZE error
    code

- Tyr:
  - Adopt vertical import style per kernel Rust guidelines

  - Clarify driver/device type names and use DRM device type alias
    consistently across the driver

  - Fix GPU model/version decoding in GpuInfo

- Workqueue:
  - Add ARef<T> support for work and delayed work

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: "Danilo Krummrich" <dakr@kernel.org>
Link: https://patch.msgid.link/DHGH4BLT03BU.ZJH5U52WE8BY@kernel.org

1 files changed, 80 insertions, 24 deletions

diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs
index d49a9ba02635..75acda7ba500 100644
--- a/rust/kernel/drm/gem/mod.rs
+++ b/rust/kernel/drm/gem/mod.rs
@@ -5,15 +5,66 @@
 //! C header: [`include/drm/drm_gem.h`](srctree/include/drm/drm_gem.h)
 
 use crate::{
-    alloc::flags::*,
-    bindings, drm,
-    drm::driver::{AllocImpl, AllocOps},
-    error::{to_result, Result},
+    bindings,
+    drm::{
+        self,
+        driver::{
+            AllocImpl,
+            AllocOps, //
+        },
+    },
+    error::to_result,
     prelude::*,
-    sync::aref::{ARef, AlwaysRefCounted},
+    sync::aref::{
+        ARef,
+        AlwaysRefCounted, //
+    },
     types::Opaque,
 };
-use core::{ops::Deref, ptr::NonNull};
+use core::{
+    ops::Deref,
+    ptr::NonNull, //
+};
+
+#[cfg(CONFIG_RUST_DRM_GEM_SHMEM_HELPER)]
+pub mod shmem;
+
+/// A macro for implementing [`AlwaysRefCounted`] for any GEM object type.
+///
+/// Since all GEM objects use the same refcounting scheme.
+#[macro_export]
+macro_rules! impl_aref_for_gem_obj {
+    (
+        impl $( <$( $tparam_id:ident ),+> )? for $type:ty
+        $(
+            where
+                $( $bind_param:path : $bind_trait:path ),+
+        )?
+    ) => {
+        // SAFETY: All GEM objects are refcounted.
+        unsafe impl $( <$( $tparam_id ),+> )? $crate::sync::aref::AlwaysRefCounted for $type
+        where
+            Self: IntoGEMObject,
+            $( $( $bind_param : $bind_trait ),+ )?
+        {
+            fn inc_ref(&self) {
+                // SAFETY: The existence of a shared reference guarantees that the refcount is
+                // non-zero.
+                unsafe { bindings::drm_gem_object_get(self.as_raw()) };
+            }
+
+            unsafe fn dec_ref(obj: core::ptr::NonNull<Self>) {
+                // SAFETY: `obj` is a valid pointer to an `Object<T>`.
+                let obj = unsafe { obj.as_ref() }.as_raw();
+
+                // SAFETY: The safety requirements guarantee that the refcount is non-zero.
+                unsafe { bindings::drm_gem_object_put(obj) };
+            }
+        }
+    };
+}
+#[cfg_attr(not(CONFIG_RUST_DRM_GEM_SHMEM_HELPER), allow(unused))]
+pub(crate) use impl_aref_for_gem_obj;
 
 /// A type alias for retrieving a [`Driver`]s [`DriverFile`] implementation from its
 /// [`DriverObject`] implementation.
@@ -27,8 +78,15 @@ pub trait DriverObject: Sync + Send + Sized {
     /// Parent `Driver` for this object.
     type Driver: drm::Driver;
 
+    /// The data type to use for passing arguments to [`DriverObject::new`].
+    type Args;
+
     /// Create a new driver data object for a GEM object of a given size.
-    fn new(dev: &drm::Device<Self::Driver>, size: usize) -> impl PinInit<Self, Error>;
+    fn new(
+        dev: &drm::Device<Self::Driver>,
+        size: usize,
+        args: Self::Args,
+    ) -> impl PinInit<Self, Error>;
 
     /// Open a new handle to an existing object, associated with a File.
     fn open(_obj: &<Self::Driver as drm::Driver>::Object, _file: &DriverFile<Self>) -> Result {
@@ -162,6 +220,18 @@ pub trait BaseObject: IntoGEMObject {
 
 impl<T: IntoGEMObject> BaseObject for T {}
 
+/// Crate-private base operations shared by all GEM object classes.
+#[cfg_attr(not(CONFIG_RUST_DRM_GEM_SHMEM_HELPER), expect(unused))]
+pub(crate) trait BaseObjectPrivate: IntoGEMObject {
+    /// Return a pointer to this object's dma_resv.
+    fn raw_dma_resv(&self) -> *mut bindings::dma_resv {
+        // SAFETY: `self.as_raw()` always returns a valid pointer to the base DRM GEM object.
+        unsafe { (*self.as_raw()).resv }
+    }
+}
+
+impl<T: IntoGEMObject> BaseObjectPrivate for T {}
+
 /// A base GEM object.
 ///
 /// # Invariants
@@ -195,11 +265,11 @@ impl<T: DriverObject> Object<T> {
     };
 
     /// Create a new GEM object.
-    pub fn new(dev: &drm::Device<T::Driver>, size: usize) -> Result<ARef<Self>> {
+    pub fn new(dev: &drm::Device<T::Driver>, size: usize, args: T::Args) -> Result<ARef<Self>> {
         let obj: Pin<KBox<Self>> = KBox::pin_init(
             try_pin_init!(Self {
                 obj: Opaque::new(bindings::drm_gem_object::default()),
-                data <- T::new(dev, size),
+                data <- T::new(dev, size, args),
             }),
             GFP_KERNEL,
         )?;
@@ -252,21 +322,7 @@ impl<T: DriverObject> Object<T> {
     }
 }
 
-// SAFETY: Instances of `Object<T>` are always reference-counted.
-unsafe impl<T: DriverObject> crate::sync::aref::AlwaysRefCounted for Object<T> {
-    fn inc_ref(&self) {
-        // SAFETY: The existence of a shared reference guarantees that the refcount is non-zero.
-        unsafe { bindings::drm_gem_object_get(self.as_raw()) };
-    }
-
-    unsafe fn dec_ref(obj: NonNull<Self>) {
-        // SAFETY: `obj` is a valid pointer to an `Object<T>`.
-        let obj = unsafe { obj.as_ref() };
-
-        // SAFETY: The safety requirements guarantee that the refcount is non-zero.
-        unsafe { bindings::drm_gem_object_put(obj.as_raw()) }
-    }
-}
+impl_aref_for_gem_obj!(impl<T> for Object<T> where T: DriverObject);
 
 impl<T: DriverObject> super::private::Sealed for Object<T> {}