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Add `from_slice_with_attrs` and `from_slice` methods to both `Coherent` and `CoherentBox` to turn this into a trivial one-step operation. Reviewed-by: Andreas Hindborg Reviewed-by: Gary Guo Signed-off-by: Alexandre Courbot --- rust/kernel/dma.rs | 107 +++++++++++++++++++++++++++++++++++++++++++++++++= ++++ 1 file changed, 107 insertions(+) diff --git a/rust/kernel/dma.rs b/rust/kernel/dma.rs index 8b7a9572ead2..40799fa418d6 100644 --- a/rust/kernel/dma.rs +++ b/rust/kernel/dma.rs @@ -453,6 +453,66 @@ pub fn init_at(&mut self, i: usize, init: impl Init= ) -> Result =20 Ok(()) } + + /// Allocates a region of coherent memory of the same size as `data` a= nd initializes it with a + /// copy of its contents. + /// + /// This is the [`CoherentBox`] variant of [`Coherent::from_slice_with= _attrs`]. + /// + /// # Examples + /// + /// ``` + /// use core::ops::Deref; + /// + /// # use kernel::device::{Bound, Device}; + /// use kernel::dma::{ + /// attrs::*, + /// CoherentBox + /// }; + /// + /// # fn test(dev: &Device) -> Result { + /// let data =3D [0u8, 1u8, 2u8, 3u8]; + /// let c: CoherentBox<[u8]> =3D + /// CoherentBox::from_slice_with_attrs(dev, &data, GFP_KERNEL, DMA= _ATTR_NO_WARN)?; + /// + /// assert_eq!(c.deref(), &data); + /// # Ok::<(), Error>(()) } + /// ``` + pub fn from_slice_with_attrs( + dev: &device::Device, + data: &[T], + gfp_flags: kernel::alloc::Flags, + dma_attrs: Attrs, + ) -> Result + where + T: Copy, + { + let mut slice =3D Self(Coherent::::alloc_slice_with_attrs( + dev, + data.len(), + gfp_flags, + dma_attrs, + )?); + + // PANIC: `slice` was created with length `data.len()`. + slice.copy_from_slice(data); + + Ok(slice) + } + + /// Performs the same functionality as [`CoherentBox::from_slice_with_= attrs`], except the + /// `dma_attrs` is 0 by default. + #[inline] + pub fn from_slice( + dev: &device::Device, + data: &[T], + gfp_flags: kernel::alloc::Flags, + ) -> Result + where + T: Copy, + { + Self::from_slice_with_attrs(dev, data, gfp_flags, Attrs(0)) + } } =20 impl CoherentBox { @@ -839,6 +899,53 @@ pub fn zeroed_slice( ) -> Result> { Self::zeroed_slice_with_attrs(dev, len, gfp_flags, Attrs(0)) } + + /// Allocates a region of coherent memory of the same size as `data` a= nd initializes it with a + /// copy of its contents. + /// + /// # Examples + /// + /// ``` + /// # use kernel::device::{Bound, Device}; + /// use kernel::dma::{ + /// attrs::*, + /// Coherent + /// }; + /// + /// # fn test(dev: &Device) -> Result { + /// let data =3D [0u8, 1u8, 2u8, 3u8]; + /// // `c` has the same content as `data`. + /// let c: Coherent<[u8]> =3D + /// Coherent::from_slice_with_attrs(dev, &data, GFP_KERNEL, DMA_AT= TR_NO_WARN)?; + /// + /// # Ok::<(), Error>(()) } + /// ``` + #[inline] + pub fn from_slice_with_attrs( + dev: &device::Device, + data: &[T], + gfp_flags: kernel::alloc::Flags, + dma_attrs: Attrs, + ) -> Result> + where + T: Copy, + { + CoherentBox::from_slice_with_attrs(dev, data, gfp_flags, dma_attrs= ).map(Into::into) + } + + /// Performs the same functionality as [`Coherent::from_slice_with_att= rs`], except the + /// `dma_attrs` is 0 by default. + #[inline] + pub fn from_slice( + dev: &device::Device, + data: &[T], + gfp_flags: kernel::alloc::Flags, + ) -> Result> + where + T: Copy, + { + Self::from_slice_with_attrs(dev, data, gfp_flags, Attrs(0)) + } } =20 impl Coherent<[T]> { --=20 2.53.0