Struct kernel::io_mem::IoMem

pub struct IoMem<const SIZE: usize> { /* private fields */ }

Represents a memory block of at least SIZE bytes.

Invariants

ptr is a non-null and valid address of at least SIZE bytes and returned by an ioremap variant. ptr is also 8-byte aligned.

Examples

use kernel::io_mem::{IoMem, Resource};

fn test(res: Resource) -> Result {
    // Create an io mem block of at least 100 bytes.
    // SAFETY: No DMA operations are initiated through `mem`.
    let mem = unsafe { IoMem::<100>::try_new(res) }?;

    // Read one byte from offset 10.
    let v = mem.readb(10);

    // Write value to offset 20.
    mem.writeb(v, 20);

    Ok(())
}

Implementations

impl<const SIZE: usize> IoMem<SIZE>

pub unsafe fn try_new(res: Resource) -> Result<Self>

Tries to create a new instance of a memory block.

The resource described by res is mapped into the CPU’s address space so that it can be accessed directly. It is also consumed by this function so that it can’t be mapped again to a different address.

Safety

Callers must ensure that either (a) the resulting interface cannot be used to initiate DMA operations, or (b) that DMA operations initiated via the returned interface use DMA handles allocated through the dma module.

pub fn try_memcpy_fromio(&self, buffer: &mut [u8], offset: usize) -> Result

Copy memory block from an i/o memory by filling the specified buffer with it.

Examples

use kernel::io_mem::{self, IoMem, Resource};

fn test(res: Resource) -> Result {
    // Create an i/o memory block of at least 100 bytes.
    let mem = unsafe { IoMem::<100>::try_new(res) }?;

    let mut buffer: [u8; 32] = [0; 32];

    // Memcpy 16 bytes from an offset 10 of i/o memory block into the buffer.
    mem.try_memcpy_fromio(&mut buffer[..16], 10)?;

    Ok(())
}

pub fn readb(&self, offset: usize) -> u8

Reads IO data from the given offset known, at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_readb(&self, offset: usize) -> Result<u8>

Reads IO data from the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn readw(&self, offset: usize) -> u16

Reads IO data from the given offset known, at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_readw(&self, offset: usize) -> Result<u16>

Reads IO data from the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn readl(&self, offset: usize) -> u32

Reads IO data from the given offset known, at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_readl(&self, offset: usize) -> Result<u32>

Reads IO data from the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn readq(&self, offset: usize) -> u64

Reads IO data from the given offset known, at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_readq(&self, offset: usize) -> Result<u64>

Reads IO data from the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn readb_relaxed(&self, offset: usize) -> u8

Reads IO data from the given offset known, at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_readb_relaxed(&self, offset: usize) -> Result<u8>

Reads IO data from the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn readw_relaxed(&self, offset: usize) -> u16

Reads IO data from the given offset known, at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_readw_relaxed(&self, offset: usize) -> Result<u16>

Reads IO data from the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn readl_relaxed(&self, offset: usize) -> u32

Reads IO data from the given offset known, at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_readl_relaxed(&self, offset: usize) -> Result<u32>

Reads IO data from the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn readq_relaxed(&self, offset: usize) -> u64

Reads IO data from the given offset known, at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_readq_relaxed(&self, offset: usize) -> Result<u64>

Reads IO data from the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn writeb(&self, value: u8, offset: usize)

Writes IO data to the given offset, known at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_writeb(&self, value: u8, offset: usize) -> Result

Writes IO data to the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn writew(&self, value: u16, offset: usize)

Writes IO data to the given offset, known at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_writew(&self, value: u16, offset: usize) -> Result

Writes IO data to the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn writel(&self, value: u32, offset: usize)

Writes IO data to the given offset, known at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_writel(&self, value: u32, offset: usize) -> Result

Writes IO data to the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn writeq(&self, value: u64, offset: usize)

Writes IO data to the given offset, known at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_writeq(&self, value: u64, offset: usize) -> Result

Writes IO data to the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn writeb_relaxed(&self, value: u8, offset: usize)

Writes IO data to the given offset, known at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_writeb_relaxed(&self, value: u8, offset: usize) -> Result

Writes IO data to the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn writew_relaxed(&self, value: u16, offset: usize)

Writes IO data to the given offset, known at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_writew_relaxed(&self, value: u16, offset: usize) -> Result

Writes IO data to the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn writel_relaxed(&self, value: u32, offset: usize)

Writes IO data to the given offset, known at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_writel_relaxed(&self, value: u32, offset: usize) -> Result

Writes IO data to the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

pub fn writeq_relaxed(&self, value: u64, offset: usize)

Writes IO data to the given offset, known at compile time.

If the offset is not known at compile time, the build will fail.

pub fn try_writeq_relaxed(&self, value: u64, offset: usize) -> Result

Writes IO data to the given offset.

It fails if/when the offset (plus the type size) is out of bounds.

Trait Implementations

impl<const SIZE: usize> Drop for IoMem<SIZE>

fn drop(&mut self)

Executes the destructor for this type.