Macro dma_read 

macro_rules! dma_read {
    ($dma:expr, $($proj:tt)*) => { ... };
}

Reads a field of an item from an allocated region of structs.

The syntax is of the form kernel::dma_read!(dma, proj) where dma is an expression evaluating to a CoherentAllocation and proj is a projection specification.

Examples

use kernel::device::Device;
use kernel::dma::{attrs::*, CoherentAllocation};

struct MyStruct { field: u32, }

// SAFETY: All bit patterns are acceptable values for `MyStruct`.
unsafe impl kernel::transmute::FromBytes for MyStruct{};
// SAFETY: Instances of `MyStruct` have no uninitialized portions.
unsafe impl kernel::transmute::AsBytes for MyStruct{};

let whole = kernel::dma_read!(alloc, [2]?);
let field = kernel::dma_read!(alloc, [1]?.field);