Merge tag 'drm-rust-next-2025-09-16' of https://gitlab.freedesktop.org/drm/rust/kernel into drm-next

DRM Rust changes for v6.18

Alloc
  - Add BorrowedPage type and AsPageIter trait
  - Implement Vmalloc::to_page() and VmallocPageIter
  - Implement AsPageIter for VBox and VVec

DMA & Scatterlist
  - Add dma::DataDirection and type alias for dma_addr_t
  - Abstraction for struct scatterlist and struct sg_table

DRM
  - In the DRM GEM module, simplify overall use of generics, add
    DriverFile type alias and drop Object::SIZE.

Nova (Core)
  - Various register!() macro improvements (paving the way for lifting
    it to common driver infrastructure)
  - Minor VBios fixes and refactoring
  - Minor firmware request refactoring
  - Advance firmware boot stages; process Booter and patch its
    signature, process GSP and GSP bootloader
  - Switch development fimrware version to r570.144
  - Add basic firmware bindings for r570.144
  - Move GSP boot code to its own module
  - Clean up and take advantage of pin-init features to store most of
    the driver's private data within a single allocation
  - Update ARef import from sync::aref
  - Add website to MAINTAINERS entry

Nova (DRM)
  - Update ARef import from sync::aref
  - Add website to MAINTAINERS entry

Pin-Init
  - Merge pin-init PR from Benno
    - `#[pin_data]` now generates a `*Projection` struct similar to the
      `pin-project` crate.

    - Add initializer code blocks to `[try_][pin_]init!` macros: make
      initializer macros accept any number of `_: {/* arbitrary code
      */},` & make them run the code at that point.

    - Make the `[try_][pin_]init!` macros expose initialized fields via
      a `let` binding as `&mut T` or `Pin<&mut T>` for later fields.

Rust
  - Various methods for AsBytes and FromBytes traits

Tyr
  - Initial Rust driver skeleton for ARM Mali GPUs.
    - It can power up the GPU, query for GPU metatdata through MMIO and
      provide the metadata to userspace via DRM device IOCTL (struct
      drm_panthor_dev_query).

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

From: "Danilo Krummrich" <dakr@kernel.org>
Link: https://lore.kernel.org/r/DCUC4SY6SRBD.1ZLHAIQZOC6KG@kernel.org

1 files changed, 102 insertions, 0 deletions

diff --git a/rust/kernel/alloc/allocator/iter.rs b/rust/kernel/alloc/allocator/iter.rs
new file mode 100644
index 000000000000..5759f86029b7
--- /dev/null
+++ b/rust/kernel/alloc/allocator/iter.rs
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use super::Vmalloc;
+use crate::page;
+use core::marker::PhantomData;
+use core::ptr::NonNull;
+
+/// An [`Iterator`] of [`page::BorrowedPage`] items owned by a [`Vmalloc`] allocation.
+///
+/// # Guarantees
+///
+/// The pages iterated by the [`Iterator`] appear in the order as they are mapped in the CPU's
+/// virtual address space ascendingly.
+///
+/// # Invariants
+///
+/// - `buf` is a valid and [`page::PAGE_SIZE`] aligned pointer into a [`Vmalloc`] allocation.
+/// - `size` is the number of bytes from `buf` until the end of the [`Vmalloc`] allocation `buf`
+///   points to.
+pub struct VmallocPageIter<'a> {
+    /// The base address of the [`Vmalloc`] buffer.
+    buf: NonNull<u8>,
+    /// The size of the buffer pointed to by `buf` in bytes.
+    size: usize,
+    /// The current page index of the [`Iterator`].
+    index: usize,
+    _p: PhantomData<page::BorrowedPage<'a>>,
+}
+
+impl<'a> Iterator for VmallocPageIter<'a> {
+    type Item = page::BorrowedPage<'a>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let offset = self.index.checked_mul(page::PAGE_SIZE)?;
+
+        // Even though `self.size()` may be smaller than `Self::page_count() * page::PAGE_SIZE`, it
+        // is always a number between `(Self::page_count() - 1) * page::PAGE_SIZE` and
+        // `Self::page_count() * page::PAGE_SIZE`, hence the check below is sufficient.
+        if offset < self.size() {
+            self.index += 1;
+        } else {
+            return None;
+        }
+
+        // TODO: Use `NonNull::add()` instead, once the minimum supported compiler version is
+        // bumped to 1.80 or later.
+        //
+        // SAFETY: `offset` is in the interval `[0, (self.page_count() - 1) * page::PAGE_SIZE]`,
+        // hence the resulting pointer is guaranteed to be within the same allocation.
+        let ptr = unsafe { self.buf.as_ptr().add(offset) };
+
+        // SAFETY: `ptr` is guaranteed to be non-null given that it is derived from `self.buf`.
+        let ptr = unsafe { NonNull::new_unchecked(ptr) };
+
+        // SAFETY:
+        // - `ptr` is a valid pointer to a `Vmalloc` allocation.
+        // - `ptr` is valid for the duration of `'a`.
+        Some(unsafe { Vmalloc::to_page(ptr) })
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let remaining = self.page_count().saturating_sub(self.index);
+
+        (remaining, Some(remaining))
+    }
+}
+
+impl<'a> VmallocPageIter<'a> {
+    /// Creates a new [`VmallocPageIter`] instance.
+    ///
+    /// # Safety
+    ///
+    /// - `buf` must be a [`page::PAGE_SIZE`] aligned pointer into a [`Vmalloc`] allocation.
+    /// - `buf` must be valid for at least the lifetime of `'a`.
+    /// - `size` must be the number of bytes from `buf` until the end of the [`Vmalloc`] allocation
+    ///   `buf` points to.
+    pub unsafe fn new(buf: NonNull<u8>, size: usize) -> Self {
+        // INVARIANT: By the safety requirements, `buf` is a valid and `page::PAGE_SIZE` aligned
+        // pointer into a [`Vmalloc`] allocation.
+        Self {
+            buf,
+            size,
+            index: 0,
+            _p: PhantomData,
+        }
+    }
+
+    /// Returns the size of the backing [`Vmalloc`] allocation in bytes.
+    ///
+    /// Note that this is the size the [`Vmalloc`] allocation has been allocated with. Hence, this
+    /// number may be smaller than `[`Self::page_count`] * [`page::PAGE_SIZE`]`.
+    #[inline]
+    pub fn size(&self) -> usize {
+        self.size
+    }
+
+    /// Returns the number of pages owned by the backing [`Vmalloc`] allocation.
+    #[inline]
+    pub fn page_count(&self) -> usize {
+        self.size().div_ceil(page::PAGE_SIZE)
+    }
+}