Struct DmaBuffer 

pub struct DmaBuffer {
    frame: PhysFrame,
    order: u8,
    phys: u64,
    virt: u64,
    nframes: usize,
}

A pinned, contiguous DMA buffer.

Allocated from the buddy allocator with allocate_phys_contiguous. The underlying frames are marked with the [frame_flags::DMA] flag, preventing the buddy from recycling them while a transfer is in flight.

The buffer is automatically unpinned on Drop, using RAII to guarantee cleanup even on panic paths.

Fields

frame: PhysFrame

order: u8

phys: u64

virt: u64

nframes: usize

Number of 4 KiB frames in this buffer.

Implementations

impl DmaBuffer

pub fn alloc(bytes: usize) -> Result<Self, DmaError>

Allocate a DMA buffer large enough for bytes, pinned for the duration of the transfer. The backing memory is contiguous in physical address space.

The buffer is not zeroed (caller must overwrite every byte before the first read).

pub fn dma_addr(&self) -> PhysAddr

Physical base address : pass this to hardware DMA engines.

pub fn virt_addr(&self) -> u64

Kernel virtual address (HHDM mapping) for CPU access.

pub fn len_bytes(&self) -> usize

Number of bytes allocated (always a multiple of 4096).

Trait Implementations

impl Drop for DmaBuffer

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.

impl Send for DmaBuffer