diff --git a/rust/kernel/dma.rs b/rust/kernel/dma.rs index a33261c62e0c..586524488e5d 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> {} + /// Possible attributes associated with a DMA mapping. /// /// They can be combined with the operators `|`, `&`, and `!`. @@ -130,7 +137,7 @@ 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 { - dev: ARef, + dev: ARef, dma_handle: bindings::dma_addr_t, count: usize, cpu_addr: *mut T, @@ -152,7 +159,7 @@ impl CoherentAllocation { /// # Ok::<(), Error>(()) } /// ``` pub fn alloc_attrs( - dev: &Device, + dev: &device::Device, count: usize, gfp_flags: kernel::alloc::Flags, dma_attrs: Attrs, @@ -194,7 +201,7 @@ impl CoherentAllocation { /// Performs the same functionality as [`CoherentAllocation::alloc_attrs`], except the /// `dma_attrs` is 0 by default. pub fn alloc_coherent( - dev: &Device, + dev: &device::Device, count: usize, gfp_flags: kernel::alloc::Flags, ) -> Result> {