Struct BufferPool

pub struct BufferPool {
    buffers: [Option<DmaBuffer>; 32],
    free_list: [u16; 32],
    free_count: usize,
    total_count: usize,
    buffer_size: usize,
}

Pre-allocated buffer pool for a virtqueue.

Manages a fixed set of DMA buffers with free list tracking.

Fields

buffers: [Option<DmaBuffer>; 32]

Array of DMA buffers.

free_list: [u16; 32]

Free list (indices of free buffers).

free_count: usize

Number of free buffers.

total_count: usize

Total number of buffers in pool.

buffer_size: usize

Size of each buffer.

Implementations

impl BufferPool

pub unsafe fn new( cpu_base: *mut u8, bus_base: u64, buffer_size: usize, count: usize, ) -> Self

Create a new buffer pool from DMA region.

Arguments

• cpu_base: CPU pointer to buffer region start
• bus_base: Bus address of buffer region start
• buffer_size: Size of each buffer (should be >= 1526 for RX)
• count: Number of buffers (max 32)

Safety

• cpu_base must point to valid DMA-capable memory
• bus_base must be the corresponding device-visible address
• Memory must be at least buffer_size * count bytes

pub fn alloc(&mut self) -> Option<&mut DmaBuffer>

Allocate a buffer from the pool.

Returns None if pool is exhausted.

pub fn free(&mut self, index: u16)

Return a buffer to the pool.

Arguments

• index: Buffer index (must be valid and driver-owned)

pub fn get_mut(&mut self, index: u16) -> Option<&mut DmaBuffer>

Get mutable reference to buffer by index.

Panics

Panics if index is out of range.

pub fn get(&self, index: u16) -> Option<&DmaBuffer>

Get reference to buffer by index.

pub fn available(&self) -> usize

Get number of available (free) buffers.

pub fn total(&self) -> usize

Get total number of buffers in pool.

pub fn in_use(&self) -> usize

Get number of buffers currently in use.

pub fn is_empty(&self) -> bool

Check if pool is empty (no free buffers).

pub fn is_full(&self) -> bool

Check if pool is full (all buffers free).

pub fn buffer_size(&self) -> usize

Get buffer size.

pub fn iter(&self) -> impl Iterator<Item = &DmaBuffer>

Iterate over all buffers (for debugging).

pub fn iter_mut(&mut self) -> impl Iterator<Item = &mut DmaBuffer>

Iterate over all buffers mutably.

Trait Implementations

impl Default for BufferPool

fn default() -> Self

Returns the “default value” for a type.