[PATCH v2 3/3] rust: dma.rs: Migrate to zerocopy's `Frombytes/IntoBytes`
From: Sagar Taunk <hidden>
Date: 2026-09-06 10:29:32
Also in:
driver-core, lkml, netdev
Subsystem:
dma mapping & scatterlist api [rust], rust, the rest · Maintainers:
Danilo Krummrich, Miguel Ojeda, Linus Torvalds
Replace explicit imports of `transmute::FromBytes`/`AsBytes` with zerocopy's equivalents. Link: https://github.com/Rust-for-Linux/linux/issues/1241 Signed-off-by: Sagar Taunk <redacted> --- rust/kernel/dma.rs | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-)
diff --git a/rust/kernel/dma.rs b/rust/kernel/dma.rs
index 2ce09f8e90c6..9bd47f20c784 100644
--- a/rust/kernel/dma.rs
+++ b/rust/kernel/dma.rs@@ -25,10 +25,6 @@ prelude::*, ptr::KnownSize, sync::aref::ARef, - transmute::{ - AsBytes, - FromBytes, // - }, uaccess::UserSliceWriter, // }; use core::{
@@ -417,7 +413,7 @@ fn from(direction: DataDirection) -> Self { /// ``` pub struct CoherentBox<T: KnownSize + ?Sized>(Coherent<T>); -impl<T: AsBytes + FromBytes> CoherentBox<[T]> { +impl<T: IntoBytes + FromBytes> CoherentBox<[T]> { /// [`CoherentBox`] variant of [`Coherent::zeroed_slice_with_attrs`]. #[inline] pub fn zeroed_slice_with_attrs(
@@ -454,7 +450,7 @@ pub fn init_at<E>(&mut self, i: usize, init: impl Init<T, E>) -> Result // SAFETY: // - `ptr` is valid, properly aligned, and within this allocation. - // - `T: AsBytes + FromBytes` guarantees all bit patterns are valid, so partial writes on + // - `T: IntoBytes + FromBytes` guarantees all bit patterns are valid, so partial writes on // error cannot leave the element in an invalid state. // - The DMA address has not been exposed yet, so there is no concurrent device access. unsafe { pin_init::raw_try_init(ptr, init)? };
@@ -523,7 +519,7 @@ pub fn from_slice( } } -impl<T: AsBytes + FromBytes> CoherentBox<T> { +impl<T: IntoBytes + FromBytes> CoherentBox<T> { /// Same as [`CoherentBox::zeroed_slice_with_attrs`], but for a single element. #[inline] pub fn zeroed_with_attrs(
@@ -554,7 +550,7 @@ fn deref(&self) -> &Self::Target { } } -impl<T: AsBytes + FromBytes + KnownSize + ?Sized> DerefMut for CoherentBox<T> { +impl<T: IntoBytes + FromBytes + KnownSize + ?Sized> DerefMut for CoherentBox<T> { #[inline] fn deref_mut(&mut self) -> &mut Self::Target { // SAFETY:
@@ -565,7 +561,7 @@ fn deref_mut(&mut self) -> &mut Self::Target { } } -impl<T: AsBytes + FromBytes + KnownSize + ?Sized> From<CoherentBox<T>> for Coherent<T> { +impl<T: IntoBytes + FromBytes + KnownSize + ?Sized> From<CoherentBox<T>> for Coherent<T> { #[inline] fn from(value: CoherentBox<T>) -> Self { value.0
@@ -663,7 +659,7 @@ pub unsafe fn as_mut(&self) -> &mut T { } } -impl<T: AsBytes + FromBytes> Coherent<T> { +impl<T: IntoBytes + FromBytes> Coherent<T> { /// Allocates a region of `T` of coherent memory. fn alloc_with_attrs( dev: &device::Device<Bound>,
@@ -753,7 +749,7 @@ pub fn init_with_attrs<E>( // SAFETY: // - `ptr` is valid, properly aligned, and points to exclusively owned memory. // - If `raw_try_init` fails, `self` is dropped, which safely frees the underlying - // `Coherent`'s DMA memory. `T: AsBytes + FromBytes` ensures there are no complex `Drop` + // `Coherent`'s DMA memory. `T: IntoBytes + FromBytes` ensures there are no complex `Drop` // requirements we are bypassing. unsafe { pin_init::raw_try_init(ptr, init)? };
@@ -948,9 +944,9 @@ unsafe impl<T: KnownSize + Send + ?Sized> Send for Coherent<T> {} // methods that access the buffer contents (`field_read`, `field_write`, `as_slice`, // `as_slice_mut`) are `unsafe`, and callers are responsible for ensuring no data races occur. // The safe methods only return metadata or raw pointers whose use requires `unsafe`. -unsafe impl<T: KnownSize + ?Sized + AsBytes + FromBytes + Sync> Sync for Coherent<T> {} +unsafe impl<T: KnownSize + ?Sized + IntoBytes + FromBytes + Sync> Sync for Coherent<T> {} -impl<T: KnownSize + AsBytes + ?Sized> debugfs::BinaryWriter for Coherent<T> { +impl<T: KnownSize + IntoBytes + ?Sized> debugfs::BinaryWriter for Coherent<T> { fn write_to_slice( &self, writer: &mut UserSliceWriter,
--
2.55.0