// SPDX-License-Identifier: GPL-2.0 //! Memory-mapped IO.//!//! C header: [`include/asm-generic/io.h`](srctree/include/asm-generic/io.h) use crate::{ bindings, prelude::*, //}; pub mod mem;pub mod poll;pub mod resource; pub use resource::Resource; /// Physical address type.////// This is a type alias to either `u32` or `u64` depending on the config option/// `CONFIG_PHYS_ADDR_T_64BIT`, and it can be a u64 even on 32-bit architectures.pub type PhysAddr = bindings::phys_addr_t; /// Resource Size type.////// This is a type alias to either `u32` or `u64` depending on the config option/// `CONFIG_PHYS_ADDR_T_64BIT`, and it can be a u64 even on 32-bit architectures.pub type ResourceSize = bindings::resource_size_t; /// Raw representation of an MMIO region.////// By itself, the existence of an instance of this structure does not provide any guarantees that/// the represented MMIO region does exist or is properly mapped.////// Instead, the bus specific MMIO implementation must convert this raw representation into an `Io`/// instance providing the actual memory accessors. Only by the conversion into an `Io` structure/// any guarantees are given.pub struct IoRaw<const SIZE: usize = 0> { addr: usize, maxsize: usize,} impl<const SIZE: usize> IoRaw<SIZE> { /// Returns a new `IoRaw` instance on success, an error otherwise. pub fn new(addr: usize, maxsize: usize) -> Result<Self> { if maxsize < SIZE { return Err(EINVAL); } Ok(Self { addr, maxsize }) } /// Returns the base address of the MMIO region. #[inline] pub fn addr(&self) -> usize { self.addr } /// Returns the maximum size of the MMIO region. #[inline] pub fn maxsize(&self) -> usize { self.maxsize }} /// IO-mapped memory region.////// The creator (usually a subsystem / bus such as PCI) is responsible for creating the/// mapping, performing an additional region request etc.////// # Invariant////// `addr` is the start and `maxsize` the length of valid I/O mapped memory region of size/// `maxsize`.////// # Examples////// ```no_run/// use kernel::{/// bindings,/// ffi::c_void,/// io::{/// Io,/// IoRaw,/// PhysAddr,/// },/// };/// use core::ops::Deref;////// // See also [`pci::Bar`] for a real example./// struct IoMem<const SIZE: usize>(IoRaw<SIZE>);////// impl<const SIZE: usize> IoMem<SIZE> {/// /// # Safety/// ////// /// [`paddr`, `paddr` + `SIZE`) must be a valid MMIO region that is mappable into the CPUs/// /// virtual address space./// unsafe fn new(paddr: usize) -> Result<Self>{/// // SAFETY: By the safety requirements of this function [`paddr`, `paddr` + `SIZE`) is/// // valid for `ioremap`./// let addr = unsafe { bindings::ioremap(paddr as PhysAddr, SIZE) };/// if addr.is_null() {/// return Err(ENOMEM);/// }////// Ok(IoMem(IoRaw::new(addr as usize, SIZE)?))/// }/// }////// impl<const SIZE: usize> Drop for IoMem<SIZE> {/// fn drop(&mut self) {/// // SAFETY: `self.0.addr()` is guaranteed to be properly mapped by `Self::new`./// unsafe { bindings::iounmap(self.0.addr() as *mut c_void); };/// }/// }////// impl<const SIZE: usize> Deref for IoMem<SIZE> {/// type Target = Io<SIZE>;////// fn deref(&self) -> &Self::Target {/// // SAFETY: The memory range stored in `self` has been properly mapped in `Self::new`./// unsafe { Io::from_raw(&self.0) }/// }/// }//////# fn no_run() -> Result<(), Error> {/// // SAFETY: Invalid usage for example purposes./// let iomem = unsafe { IoMem::<{ core::mem::size_of::<u32>() }>::new(0xBAAAAAAD)? };/// iomem.write32(0x42, 0x0);/// assert!(iomem.try_write32(0x42, 0x0).is_ok());/// assert!(iomem.try_write32(0x42, 0x4).is_err());/// # Ok(())/// # }/// ```#[repr(transparent)]pub struct Io<const SIZE: usize = 0>(IoRaw<SIZE>); macro_rules! define_read { ($(#[$attr:meta])* $name:ident, $try_name:ident, $c_fn:ident -> $type_name:ty) => { /// Read IO data from a given offset known at compile time. /// /// Bound checks are performed on compile time, hence if the offset is not known at compile /// time, the build will fail. $(#[$attr])* // Always inline to optimize out error path of `io_addr_assert`. #[inline(always)] pub fn $name(&self, offset: usize) -> $type_name { let addr = self.io_addr_assert::<$type_name>(offset); // SAFETY: By the type invariant `addr` is a valid address for MMIO operations. unsafe { bindings::$c_fn(addr as *const c_void) } } /// Read IO data from a given offset. /// /// Bound checks are performed on runtime, it fails if the offset (plus the type size) is /// out of bounds. $(#[$attr])* pub fn $try_name(&self, offset: usize) -> Result<$type_name> { let addr = self.io_addr::<$type_name>(offset)?; // SAFETY: By the type invariant `addr` is a valid address for MMIO operations. Ok(unsafe { bindings::$c_fn(addr as *const c_void) }) } };} macro_rules! define_write { ($(#[$attr:meta])* $name:ident, $try_name:ident, $c_fn:ident <- $type_name:ty) => { /// Write IO data from a given offset known at compile time. /// /// Bound checks are performed on compile time, hence if the offset is not known at compile /// time, the build will fail. $(#[$attr])* // Always inline to optimize out error path of `io_addr_assert`. #[inline(always)] pub fn $name(&self, value: $type_name, offset: usize) { let addr = self.io_addr_assert::<$type_name>(offset); // SAFETY: By the type invariant `addr` is a valid address for MMIO operations. unsafe { bindings::$c_fn(value, addr as *mut c_void) } } /// Write IO data from a given offset. /// /// Bound checks are performed on runtime, it fails if the offset (plus the type size) is /// out of bounds. $(#[$attr])* pub fn $try_name(&self, value: $type_name, offset: usize) -> Result { let addr = self.io_addr::<$type_name>(offset)?; // SAFETY: By the type invariant `addr` is a valid address for MMIO operations. unsafe { bindings::$c_fn(value, addr as *mut c_void) } Ok(()) } };} impl<const SIZE: usize> Io<SIZE> { /// Converts an `IoRaw` into an `Io` instance, providing the accessors to the MMIO mapping. /// /// # Safety /// /// Callers must ensure that `addr` is the start of a valid I/O mapped memory region of size /// `maxsize`. pub unsafe fn from_raw(raw: &IoRaw<SIZE>) -> &Self { // SAFETY: `Io` is a transparent wrapper around `IoRaw`. unsafe { &*core::ptr::from_ref(raw).cast() } } /// Returns the base address of this mapping. #[inline] pub fn addr(&self) -> usize { self.0.addr() } /// Returns the maximum size of this mapping. #[inline] pub fn maxsize(&self) -> usize { self.0.maxsize() } #[inline] const fn offset_valid<U>(offset: usize, size: usize) -> bool { let type_size = core::mem::size_of::<U>(); if let Some(end) = offset.checked_add(type_size) { end <= size && offset % type_size == 0 } else { false } } #[inline] fn io_addr<U>(&self, offset: usize) -> Result<usize> { if !Self::offset_valid::<U>(offset, self.maxsize()) { return Err(EINVAL); } // Probably no need to check, since the safety requirements of `Self::new` guarantee that // this can't overflow. self.addr().checked_add(offset).ok_or(EINVAL) } // Always inline to optimize out error path of `build_assert`. #[inline(always)] fn io_addr_assert<U>(&self, offset: usize) -> usize { build_assert!(Self::offset_valid::<U>(offset, SIZE)); self.addr() + offset } define_read!(read8, try_read8, readb -> u8); define_read!(read16, try_read16, readw -> u16); define_read!(read32, try_read32, readl -> u32); define_read!( #[cfg(CONFIG_64BIT)] read64, try_read64, readq -> u64 ); define_read!(read8_relaxed, try_read8_relaxed, readb_relaxed -> u8); define_read!(read16_relaxed, try_read16_relaxed, readw_relaxed -> u16); define_read!(read32_relaxed, try_read32_relaxed, readl_relaxed -> u32); define_read!( #[cfg(CONFIG_64BIT)] read64_relaxed, try_read64_relaxed, readq_relaxed -> u64 ); define_write!(write8, try_write8, writeb <- u8); define_write!(write16, try_write16, writew <- u16); define_write!(write32, try_write32, writel <- u32); define_write!( #[cfg(CONFIG_64BIT)] write64, try_write64, writeq <- u64 ); define_write!(write8_relaxed, try_write8_relaxed, writeb_relaxed <- u8); define_write!(write16_relaxed, try_write16_relaxed, writew_relaxed <- u16); define_write!(write32_relaxed, try_write32_relaxed, writel_relaxed <- u32); define_write!( #[cfg(CONFIG_64BIT)] write64_relaxed, try_write64_relaxed, writeq_relaxed <- u64 );}
// SPDX-License-Identifier: GPL-2.0
//! Memory-mapped IO.
//!
//! C header: [`include/asm-generic/io.h`](srctree/include/asm-generic/io.h)
use crate::{
bindings,
prelude::*, //
};
pub mod mem;
pub mod poll;
pub mod resource;
pub use resource::Resource;
/// Physical address type.
///
/// This is a type alias to either `u32` or `u64` depending on the config option
/// `CONFIG_PHYS_ADDR_T_64BIT`, and it can be a u64 even on 32-bit architectures.
pub type PhysAddr = bindings::phys_addr_t;
/// Resource Size type.
///
/// This is a type alias to either `u32` or `u64` depending on the config option
/// `CONFIG_PHYS_ADDR_T_64BIT`, and it can be a u64 even on 32-bit architectures.
pub type ResourceSize = bindings::resource_size_t;
/// Raw representation of an MMIO region.
///
/// By itself, the existence of an instance of this structure does not provide any guarantees that
/// the represented MMIO region does exist or is properly mapped.
///
/// Instead, the bus specific MMIO implementation must convert this raw representation into an `Io`
/// instance providing the actual memory accessors. Only by the conversion into an `Io` structure
/// any guarantees are given.
pub struct IoRaw<const SIZE: usize = 0> {
addr: usize,
maxsize: usize,
}
impl<const SIZE: usize> IoRaw<SIZE> {
/// Returns a new `IoRaw` instance on success, an error otherwise.
pub fn new(addr: usize, maxsize: usize) -> Result<Self> {
if maxsize < SIZE {
return Err(EINVAL);
}
Ok(Self { addr, maxsize })
}
/// Returns the base address of the MMIO region.
#[inline]
pub fn addr(&self) -> usize {
self.addr
}
/// Returns the maximum size of the MMIO region.
#[inline]
pub fn maxsize(&self) -> usize {
self.maxsize
}
}
/// IO-mapped memory region.
///
/// The creator (usually a subsystem / bus such as PCI) is responsible for creating the
/// mapping, performing an additional region request etc.
///
/// # Invariant
///
/// `addr` is the start and `maxsize` the length of valid I/O mapped memory region of size
/// `maxsize`.
///
/// # Examples
///
/// ```no_run
/// use kernel::{
/// bindings,
/// ffi::c_void,
/// io::{
/// Io,
/// IoRaw,
/// PhysAddr,
/// },
/// };
/// use core::ops::Deref;
///
/// // See also [`pci::Bar`] for a real example.
/// struct IoMem<const SIZE: usize>(IoRaw<SIZE>);
///
/// impl<const SIZE: usize> IoMem<SIZE> {
/// /// # Safety
/// ///
/// /// [`paddr`, `paddr` + `SIZE`) must be a valid MMIO region that is mappable into the CPUs
/// /// virtual address space.
/// unsafe fn new(paddr: usize) -> Result<Self>{
/// // SAFETY: By the safety requirements of this function [`paddr`, `paddr` + `SIZE`) is
/// // valid for `ioremap`.
/// let addr = unsafe { bindings::ioremap(paddr as PhysAddr, SIZE) };
/// if addr.is_null() {
/// return Err(ENOMEM);
/// }
///
/// Ok(IoMem(IoRaw::new(addr as usize, SIZE)?))
/// }
/// }
///
/// impl<const SIZE: usize> Drop for IoMem<SIZE> {
/// fn drop(&mut self) {
/// // SAFETY: `self.0.addr()` is guaranteed to be properly mapped by `Self::new`.
/// unsafe { bindings::iounmap(self.0.addr() as *mut c_void); };
/// }
/// }
///
/// impl<const SIZE: usize> Deref for IoMem<SIZE> {
/// type Target = Io<SIZE>;
///
/// fn deref(&self) -> &Self::Target {
/// // SAFETY: The memory range stored in `self` has been properly mapped in `Self::new`.
/// unsafe { Io::from_raw(&self.0) }
/// }
/// }
///
///# fn no_run() -> Result<(), Error> {
/// // SAFETY: Invalid usage for example purposes.
/// let iomem = unsafe { IoMem::<{ core::mem::size_of::<u32>() }>::new(0xBAAAAAAD)? };
/// iomem.write32(0x42, 0x0);
/// assert!(iomem.try_write32(0x42, 0x0).is_ok());
/// assert!(iomem.try_write32(0x42, 0x4).is_err());
/// # Ok(())
/// # }
/// ```
#[repr(transparent)]
pub struct Io<const SIZE: usize = 0>(IoRaw<SIZE>);
macro_rules! define_read {
($(#[$attr:meta])* $name:ident, $try_name:ident, $c_fn:ident -> $type_name:ty) => {
/// Read IO data from a given offset known at compile time.
///
/// Bound checks are performed on compile time, hence if the offset is not known at compile
/// time, the build will fail.
$(#[$attr])*
// Always inline to optimize out error path of `io_addr_assert`.
#[inline(always)]
pub fn $name(&self, offset: usize) -> $type_name {
let addr = self.io_addr_assert::<$type_name>(offset);
// SAFETY: By the type invariant `addr` is a valid address for MMIO operations.
unsafe { bindings::$c_fn(addr as *const c_void) }
}
/// Read IO data from a given offset.
///
/// Bound checks are performed on runtime, it fails if the offset (plus the type size) is
/// out of bounds.
$(#[$attr])*
pub fn $try_name(&self, offset: usize) -> Result<$type_name> {
let addr = self.io_addr::<$type_name>(offset)?;
// SAFETY: By the type invariant `addr` is a valid address for MMIO operations.
Ok(unsafe { bindings::$c_fn(addr as *const c_void) })
}
};
}
macro_rules! define_write {
($(#[$attr:meta])* $name:ident, $try_name:ident, $c_fn:ident <- $type_name:ty) => {
/// Write IO data from a given offset known at compile time.
///
/// Bound checks are performed on compile time, hence if the offset is not known at compile
/// time, the build will fail.
$(#[$attr])*
// Always inline to optimize out error path of `io_addr_assert`.
#[inline(always)]
pub fn $name(&self, value: $type_name, offset: usize) {
let addr = self.io_addr_assert::<$type_name>(offset);
// SAFETY: By the type invariant `addr` is a valid address for MMIO operations.
unsafe { bindings::$c_fn(value, addr as *mut c_void) }
}
/// Write IO data from a given offset.
///
/// Bound checks are performed on runtime, it fails if the offset (plus the type size) is
/// out of bounds.
$(#[$attr])*
pub fn $try_name(&self, value: $type_name, offset: usize) -> Result {
let addr = self.io_addr::<$type_name>(offset)?;
// SAFETY: By the type invariant `addr` is a valid address for MMIO operations.
unsafe { bindings::$c_fn(value, addr as *mut c_void) }
Ok(())
}
};
}
impl<const SIZE: usize> Io<SIZE> {
/// Converts an `IoRaw` into an `Io` instance, providing the accessors to the MMIO mapping.
///
/// # Safety
///
/// Callers must ensure that `addr` is the start of a valid I/O mapped memory region of size
/// `maxsize`.
pub unsafe fn from_raw(raw: &IoRaw<SIZE>) -> &Self {
// SAFETY: `Io` is a transparent wrapper around `IoRaw`.
unsafe { &*core::ptr::from_ref(raw).cast() }
}
/// Returns the base address of this mapping.
#[inline]
pub fn addr(&self) -> usize {
self.0.addr()
}
/// Returns the maximum size of this mapping.
#[inline]
pub fn maxsize(&self) -> usize {
self.0.maxsize()
}
#[inline]
const fn offset_valid<U>(offset: usize, size: usize) -> bool {
let type_size = core::mem::size_of::<U>();
if let Some(end) = offset.checked_add(type_size) {
end <= size && offset % type_size == 0
} else {
false
}
}
#[inline]
fn io_addr<U>(&self, offset: usize) -> Result<usize> {
if !Self::offset_valid::<U>(offset, self.maxsize()) {
return Err(EINVAL);
}
// Probably no need to check, since the safety requirements of `Self::new` guarantee that
// this can't overflow.
self.addr().checked_add(offset).ok_or(EINVAL)
}
// Always inline to optimize out error path of `build_assert`.
#[inline(always)]
fn io_addr_assert<U>(&self, offset: usize) -> usize {
build_assert!(Self::offset_valid::<U>(offset, SIZE));
self.addr() + offset
}
define_read!(read8, try_read8, readb -> u8);
define_read!(read16, try_read16, readw -> u16);
define_read!(read32, try_read32, readl -> u32);
define_read!(
#[cfg(CONFIG_64BIT)]
read64,
try_read64,
readq -> u64
);
define_read!(read8_relaxed, try_read8_relaxed, readb_relaxed -> u8);
define_read!(read16_relaxed, try_read16_relaxed, readw_relaxed -> u16);
define_read!(read32_relaxed, try_read32_relaxed, readl_relaxed -> u32);
define_read!(
#[cfg(CONFIG_64BIT)]
read64_relaxed,
try_read64_relaxed,
readq_relaxed -> u64
);
define_write!(write8, try_write8, writeb <- u8);
define_write!(write16, try_write16, writew <- u16);
define_write!(write32, try_write32, writel <- u32);
define_write!(
#[cfg(CONFIG_64BIT)]
write64,
try_write64,
writeq <- u64
);
define_write!(write8_relaxed, try_write8_relaxed, writeb_relaxed <- u8);
define_write!(write16_relaxed, try_write16_relaxed, writew_relaxed <- u16);
define_write!(write32_relaxed, try_write32_relaxed, writel_relaxed <- u32);
define_write!(
#[cfg(CONFIG_64BIT)]
write64_relaxed,
try_write64_relaxed,
writeq_relaxed <- u64
);
}