Commit d06d5f66 authored by Danilo Krummrich's avatar Danilo Krummrich
Browse files

rust: dma: implement `dma::Device` trait 



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: default avatarAbdiel Janulgue <abdiel.janulgue@gmail.com>
Reviewed-by: default avatarDaniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250716150354.51081-2-dakr@kernel.org


Signed-off-by: default avatarDanilo Krummrich <dakr@kernel.org>
parent 9a8682f0

rust/kernel/dma.rs

+12 −5
Original line number Diff line number Diff line
@@ -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 `!`.
@@ -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<T: AsBytes + FromBytes> {

    dev: ARef<Device>,

    dev: ARef<device::Device>,

    dma_handle: bindings::dma_addr_t,

    count: usize,

    cpu_addr: *mut T,
@@ -152,7 +159,7 @@ 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,
@@ -194,7 +201,7 @@ 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>> {