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, 68 insertions, 2 deletions

diff --git a/rust/kernel/num/bounded.rs b/rust/kernel/num/bounded.rs
index fa81acbdc8c2..bbab6bbcb315 100644
--- a/rust/kernel/num/bounded.rs
+++ b/rust/kernel/num/bounded.rs
@@ -379,6 +379,9 @@ where
 
     /// Returns the wrapped value as the backing type.
     ///
+    /// This is similar to the [`Deref`] implementation, but doesn't enforce the size invariant of
+    /// the [`Bounded`], which might produce slightly less optimal code.
+    ///
     /// # Examples
     ///
     /// ```
@@ -387,8 +390,8 @@ where
     /// let v = Bounded::<u32, 4>::new::<7>();
     /// assert_eq!(v.get(), 7u32);
     /// ```
-    pub fn get(self) -> T {
-        *self.deref()
+    pub const fn get(self) -> T {
+        self.0
     }
 
     /// Increases the number of bits usable for `self`.
@@ -473,6 +476,48 @@ where
         // `N` bits, and with the same signedness.
         unsafe { Bounded::__new(value) }
     }
+
+    /// Right-shifts `self` by `SHIFT` and returns the result as a `Bounded<_, RES>`, where `RES >=
+    /// N - SHIFT`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use kernel::num::Bounded;
+    ///
+    /// let v = Bounded::<u32, 16>::new::<0xff00>();
+    /// let v_shifted: Bounded::<u32, 8> = v.shr::<8, _>();
+    ///
+    /// assert_eq!(v_shifted.get(), 0xff);
+    /// ```
+    pub fn shr<const SHIFT: u32, const RES: u32>(self) -> Bounded<T, RES> {
+        const { assert!(RES + SHIFT >= N) }
+
+        // SAFETY: We shift the value right by `SHIFT`, reducing the number of bits needed to
+        // represent the shifted value by as much, and just asserted that `RES >= N - SHIFT`.
+        unsafe { Bounded::__new(self.0 >> SHIFT) }
+    }
+
+    /// Left-shifts `self` by `SHIFT` and returns the result as a `Bounded<_, RES>`, where `RES >=
+    /// N + SHIFT`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use kernel::num::Bounded;
+    ///
+    /// let v = Bounded::<u32, 8>::new::<0xff>();
+    /// let v_shifted: Bounded::<u32, 16> = v.shl::<8, _>();
+    ///
+    /// assert_eq!(v_shifted.get(), 0xff00);
+    /// ```
+    pub fn shl<const SHIFT: u32, const RES: u32>(self) -> Bounded<T, RES> {
+        const { assert!(RES >= N + SHIFT) }
+
+        // SAFETY: We shift the value left by `SHIFT`, augmenting the number of bits needed to
+        // represent the shifted value by as much, and just asserted that `RES >= N + SHIFT`.
+        unsafe { Bounded::__new(self.0 << SHIFT) }
+    }
 }
 
 impl<T, const N: u32> Deref for Bounded<T, N>
@@ -1059,3 +1104,24 @@ where
         unsafe { Self::__new(T::from(value)) }
     }
 }
+
+impl<T> Bounded<T, 1>
+where
+    T: Integer + Zeroable,
+{
+    /// Converts this [`Bounded`] into a [`bool`].
+    ///
+    /// This is a shorter way of writing `bool::from(self)`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use kernel::num::Bounded;
+    ///
+    /// assert_eq!(Bounded::<u8, 1>::new::<0>().into_bool(), false);
+    /// assert_eq!(Bounded::<u8, 1>::new::<1>().into_bool(), true);
+    /// ```
+    pub fn into_bool(self) -> bool {
+        self.into()
+    }
+}