Add a trait that defines the DMA specific methods of devices.
The `dma::Device` trait is to be implemented by bus device
representations, where the underlying bus is capable of DMA, such as
`pci::Device` or `platform::Device`.
Reviewed-by: Abdiel Janulgue <abdiel.janulgue@xxxxxxxxx>
Signed-off-by: Danilo Krummrich <dakr@xxxxxxxxxx>
---
rust/kernel/dma.rs | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/rust/kernel/dma.rs b/rust/kernel/dma.rs
index 2ac4c47aeed3..f0af23d08e8d 100644
--- a/rust/kernel/dma.rs
+++ b/rust/kernel/dma.rs
@@ -5,14 +5,21 @@
//! C header: [`include/linux/dma-mapping.h`](srctree/include/linux/dma-mapping.h)
use crate::{
- bindings, build_assert,
- device::{Bound, Device},
+ bindings, build_assert, device,
+ device::Bound,
error::code::*,
error::Result,
transmute::{AsBytes, FromBytes},
types::ARef,
};
+/// Trait to be implemented by DMA capable bus devices.
+///
+/// The [`dma::Device`](Device) trait should be implemented by bus specific device representations,
+/// where the underlying bus is DMA capable, such as [`pci::Device`](::kernel::pci::Device) or
+/// [`platform::Device`](::kernel::platform::Device).
+pub trait Device: AsRef<device::Device<Core>> {}
+
/// Possible attributes associated with a DMA mapping.
///
/// They can be combined with the operators `|`, `&`, and `!`.
@@ -132,7 +139,7 @@ pub mod attrs {
// Hence, find a way to revoke the device resources of a `CoherentAllocation`, but not the
// entire `CoherentAllocation` including the allocated memory itself.
pub struct CoherentAllocation<T: AsBytes + FromBytes> {
- dev: ARef<Device>,
+ dev: ARef<device::Device>,
dma_handle: bindings::dma_addr_t,
count: usize,
cpu_addr: *mut T,
@@ -154,7 +161,7 @@ impl<T: AsBytes + FromBytes> CoherentAllocation<T> {
/// # Ok::<(), Error>(()) }
/// ```
pub fn alloc_attrs(
- dev: &Device<Bound>,
+ dev: &device::Device<Bound>,
count: usize,
gfp_flags: kernel::alloc::Flags,
dma_attrs: Attrs,
@@ -199,7 +206,7 @@ pub fn alloc_attrs(
/// Performs the same functionality as [`CoherentAllocation::alloc_attrs`], except the
/// `dma_attrs` is 0 by default.
pub fn alloc_coherent(
- dev: &Device<Bound>,
+ dev: &device::Device<Bound>,
count: usize,
gfp_flags: kernel::alloc::Flags,
) -> Result<CoherentAllocation<T>> {
--
2.50.0
