Struct DmaRegion

pub struct DmaRegion {
    pub cpu_ptr: *mut u8,
    pub bus_addr: u64,
    pub size: usize,
}

DMA-capable memory region.

Contains both the CPU-accessible pointer and the device-visible bus address.

Fields

cpu_ptr: *mut u8

CPU-accessible pointer to the region.

bus_addr: u64

Device-visible bus address.

size: usize

Total size of the region in bytes.

Implementations

impl DmaRegion

pub const MIN_SIZE: usize = 2_097_152usize

Minimum region size (2MB).

pub const DEFAULT_QUEUE_SIZE: usize = 32usize

Default queue size (number of descriptors).

pub const DEFAULT_BUFFER_SIZE: usize = 2_048usize

Default buffer size (2KB each).

pub const RX_DESC_OFFSET: usize = 0usize

RX descriptor table offset.

pub const RX_AVAIL_OFFSET: usize = 512usize

RX available ring offset.

pub const RX_USED_OFFSET: usize = 1_024usize

RX used ring offset.

pub const TX_DESC_OFFSET: usize = 2_048usize

TX descriptor table offset.

pub const TX_AVAIL_OFFSET: usize = 2_560usize

TX available ring offset.

pub const TX_USED_OFFSET: usize = 3_072usize

TX used ring offset.

pub const RX_BUFFERS_OFFSET: usize = 4_096usize

RX buffers offset.

pub const TX_BUFFERS_OFFSET: usize = 69_632usize

TX buffers offset.

pub unsafe fn new(cpu_ptr: *mut u8, bus_addr: u64, size: usize) -> Self

Create a new DMA region.

Safety

• cpu_ptr must point to valid DMA-capable memory
• bus_addr must be the corresponding device-visible address
• Region must be properly aligned (page-aligned preferred)

pub fn cpu_base(&self) -> *mut u8

Get CPU base pointer.

pub fn bus_base(&self) -> u64

Get bus base address.

pub fn size(&self) -> usize

Get total size.

pub fn rx_desc_cpu(&self) -> *mut u8

Get CPU pointer for RX descriptor table.

pub fn rx_desc_bus(&self) -> u64

Get bus address for RX descriptor table.

pub fn rx_avail_cpu(&self) -> *mut u8

Get CPU pointer for RX available ring.

pub fn rx_avail_bus(&self) -> u64

Get bus address for RX available ring.

pub fn rx_used_cpu(&self) -> *mut u8

Get CPU pointer for RX used ring.

pub fn rx_used_bus(&self) -> u64

Get bus address for RX used ring.

pub fn tx_desc_cpu(&self) -> *mut u8

Get CPU pointer for TX descriptor table.

pub fn tx_desc_bus(&self) -> u64

Get bus address for TX descriptor table.

pub fn tx_avail_cpu(&self) -> *mut u8

Get CPU pointer for TX available ring.

pub fn tx_avail_bus(&self) -> u64

Get bus address for TX available ring.

pub fn tx_used_cpu(&self) -> *mut u8

Get CPU pointer for TX used ring.

pub fn tx_used_bus(&self) -> u64

Get bus address for TX used ring.

pub fn rx_buffers_cpu(&self) -> *mut u8

Get CPU pointer for RX buffers.

pub fn rx_buffers_bus(&self) -> u64

Get bus address for RX buffers.

pub fn tx_buffers_cpu(&self) -> *mut u8

Get CPU pointer for TX buffers.

pub fn tx_buffers_bus(&self) -> u64

Get bus address for TX buffers.

pub fn buffer_cpu( &self, offset: usize, index: usize, buffer_size: usize, ) -> *mut u8

Calculate buffer address by index.

pub fn buffer_bus(&self, offset: usize, index: usize, buffer_size: usize) -> u64

Calculate buffer bus address by index.

Trait Implementations

impl Send for DmaRegion

impl Sync for DmaRegion