Struct syscall::io::PhysBox

pub struct PhysBox { /* fields omitted */ }

An RAII guard of a physical memory allocation. Currently all physically allocated memory are page-aligned and take up at least 4k of space (on x86_64).

Implementations

impl PhysBox

pub unsafe fn from_raw_parts(address: usize, size: usize) -> Self

Construct a PhysBox from an address and a size.

Safety

This function is unsafe because when dropping, Self has to a valid allocation.

pub fn address(&self) -> usize

Retrieve the byte address in physical memory, of this allocation.

pub fn size(&self) -> usize

Retrieve the size in bytes of the alloc.

pub fn new_in_32bit_space(size: usize) -> Result<Self>

Allocate physical memory that must reside in 32-bit space.

pub fn new_with_flags(size: usize, flags: PhysallocFlags) -> Result<Self>

pub fn new_partial_allocation(
    size: usize,
    flags: PhysallocFlags,
    strategy: Option<PartialAllocStrategy>,
    min: usize
) -> Result<Self>

"Partially" allocate physical memory, in the sense that the allocation may be smaller than expected, but still with a minimum limit. This is particularly useful when the physical memory space is fragmented, and a device supports scatter-gather I/O. In that case, the driver can optimistically request e.g. 1 alloc of 1 MiB, with the minimum of 512 KiB. If that first allocation only returns half the size, the driver can do another allocation and then let the device use both buffers.

pub fn new(size: usize) -> Result<Self>

Trait Implementations

impl Debug for PhysBox

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Drop for PhysBox

fn drop(&mut self)

Executes the destructor for this type.