// 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 register;pub mod resource; pub use crate::register;pub use resource::Resource; use register::LocatedRegister; /// 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/// `Mmio` instance providing the actual memory accessors. Only by the conversion into an `Mmio`/// structure any guarantees are given.pub struct MmioRaw<const SIZE: usize = 0> { addr: usize, maxsize: usize,} impl<const SIZE: usize> MmioRaw<SIZE> { /// Returns a new `MmioRaw` 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,/// IoKnownSize,/// Mmio,/// MmioRaw,/// PhysAddr,/// },/// };/// use core::ops::Deref;////// // See also `pci::Bar` for a real example./// struct IoMem<const SIZE: usize>(MmioRaw<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(MmioRaw::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 = Mmio<SIZE>;////// fn deref(&self) -> &Self::Target {/// // SAFETY: The memory range stored in `self` has been properly mapped in `Self::new`./// unsafe { Mmio::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 Mmio<const SIZE: usize = 0>(MmioRaw<SIZE>); /// Checks whether an access of type `U` at the given `offset`/// is valid within this region.#[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 }} /// Trait indicating that an I/O backend supports operations of a certain type and providing an/// implementation for these operations.////// Different I/O backends can implement this trait to expose only the operations they support.////// For example, a PCI configuration space may implement `IoCapable<u8>`, `IoCapable<u16>`,/// and `IoCapable<u32>`, but not `IoCapable<u64>`, while an MMIO region on a 64-bit/// system might implement all four.pub trait IoCapable<T> { /// Performs an I/O read of type `T` at `address` and returns the result. /// /// # Safety /// /// The range `[address..address + size_of::<T>()]` must be within the bounds of `Self`. unsafe fn io_read(&self, address: usize) -> T; /// Performs an I/O write of `value` at `address`. /// /// # Safety /// /// The range `[address..address + size_of::<T>()]` must be within the bounds of `Self`. unsafe fn io_write(&self, value: T, address: usize);} /// Describes a given I/O location: its offset, width, and type to convert the raw value from and/// into.////// This trait is the key abstraction allowing [`Io::read`], [`Io::write`], and [`Io::update`] (and/// their fallible [`try_read`](Io::try_read), [`try_write`](Io::try_write) and/// [`try_update`](Io::try_update) counterparts) to work uniformly with both raw [`usize`] offsets/// (for primitive types like [`u32`]) and typed ones (like those generated by the [`register!`]/// macro).////// An `IoLoc<T>` carries three pieces of information:////// - The offset to access (returned by [`IoLoc::offset`]),/// - The width of the access (determined by [`IoLoc::IoType`]),/// - The type `T` in which the raw data is returned or provided.////// `T` and `IoLoc::IoType` may differ: for instance, a typed register has `T` = the register type/// with its bitfields, and `IoType` = its backing primitive (e.g. `u32`).pub trait IoLoc<T> { /// Size ([`u8`], [`u16`], etc) of the I/O performed on the returned [`offset`](IoLoc::offset). type IoType: Into<T> + From<T>; /// Consumes `self` and returns the offset of this location. fn offset(self) -> usize;} /// Implements [`IoLoc<$ty>`] for [`usize`], allowing [`usize`] to be used as a parameter of/// [`Io::read`] and [`Io::write`].macro_rules! impl_usize_ioloc { ($($ty:ty),*) => { $( impl IoLoc<$ty> for usize { type IoType = $ty; #[inline(always)] fn offset(self) -> usize { self } } )* }} // Provide the ability to read any primitive type from a [`usize`].impl_usize_ioloc!(u8, u16, u32, u64); /// Types implementing this trait (e.g. MMIO BARs or PCI config regions)/// can perform I/O operations on regions of memory.////// This is an abstract representation to be implemented by arbitrary I/O/// backends (e.g. MMIO, PCI config space, etc.).////// The [`Io`] trait provides:/// - Base address and size information/// - Helper methods for offset validation and address calculation/// - Fallible (runtime checked) accessors for different data widths////// Which I/O methods are available depends on which [`IoCapable<T>`] traits/// are implemented for the type.////// # Examples////// For MMIO regions, all widths (u8, u16, u32, and u64 on 64-bit systems) are typically/// supported. For PCI configuration space, u8, u16, and u32 are supported but u64 is not.pub trait Io { /// Returns the base address of this mapping. fn addr(&self) -> usize; /// Returns the maximum size of this mapping. fn maxsize(&self) -> usize; /// Returns the absolute I/O address for a given `offset`, /// performing runtime bound checks. #[inline] fn io_addr<U>(&self, offset: usize) -> Result<usize> { if !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) } /// Fallible 8-bit read with runtime bounds check. #[inline(always)] fn try_read8(&self, offset: usize) -> Result<u8> where Self: IoCapable<u8>, { self.try_read(offset) } /// Fallible 16-bit read with runtime bounds check. #[inline(always)] fn try_read16(&self, offset: usize) -> Result<u16> where Self: IoCapable<u16>, { self.try_read(offset) } /// Fallible 32-bit read with runtime bounds check. #[inline(always)] fn try_read32(&self, offset: usize) -> Result<u32> where Self: IoCapable<u32>, { self.try_read(offset) } /// Fallible 64-bit read with runtime bounds check. #[inline(always)] fn try_read64(&self, offset: usize) -> Result<u64> where Self: IoCapable<u64>, { self.try_read(offset) } /// Fallible 8-bit write with runtime bounds check. #[inline(always)] fn try_write8(&self, value: u8, offset: usize) -> Result where Self: IoCapable<u8>, { self.try_write(offset, value) } /// Fallible 16-bit write with runtime bounds check. #[inline(always)] fn try_write16(&self, value: u16, offset: usize) -> Result where Self: IoCapable<u16>, { self.try_write(offset, value) } /// Fallible 32-bit write with runtime bounds check. #[inline(always)] fn try_write32(&self, value: u32, offset: usize) -> Result where Self: IoCapable<u32>, { self.try_write(offset, value) } /// Fallible 64-bit write with runtime bounds check. #[inline(always)] fn try_write64(&self, value: u64, offset: usize) -> Result where Self: IoCapable<u64>, { self.try_write(offset, value) } /// Infallible 8-bit read with compile-time bounds check. #[inline(always)] fn read8(&self, offset: usize) -> u8 where Self: IoKnownSize + IoCapable<u8>, { self.read(offset) } /// Infallible 16-bit read with compile-time bounds check. #[inline(always)] fn read16(&self, offset: usize) -> u16 where Self: IoKnownSize + IoCapable<u16>, { self.read(offset) } /// Infallible 32-bit read with compile-time bounds check. #[inline(always)] fn read32(&self, offset: usize) -> u32 where Self: IoKnownSize + IoCapable<u32>, { self.read(offset) } /// Infallible 64-bit read with compile-time bounds check. #[inline(always)] fn read64(&self, offset: usize) -> u64 where Self: IoKnownSize + IoCapable<u64>, { self.read(offset) } /// Infallible 8-bit write with compile-time bounds check. #[inline(always)] fn write8(&self, value: u8, offset: usize) where Self: IoKnownSize + IoCapable<u8>, { self.write(offset, value) } /// Infallible 16-bit write with compile-time bounds check. #[inline(always)] fn write16(&self, value: u16, offset: usize) where Self: IoKnownSize + IoCapable<u16>, { self.write(offset, value) } /// Infallible 32-bit write with compile-time bounds check. #[inline(always)] fn write32(&self, value: u32, offset: usize) where Self: IoKnownSize + IoCapable<u32>, { self.write(offset, value) } /// Infallible 64-bit write with compile-time bounds check. #[inline(always)] fn write64(&self, value: u64, offset: usize) where Self: IoKnownSize + IoCapable<u64>, { self.write(offset, value) } /// Generic fallible read with runtime bounds check. /// /// # Examples /// /// Read a primitive type from an I/O address: /// /// ```no_run /// use kernel::io::{ /// Io, /// Mmio, /// }; /// /// fn do_reads(io: &Mmio) -> Result { /// // 32-bit read from address `0x10`. /// let v: u32 = io.try_read(0x10)?; /// /// // 8-bit read from address `0xfff`. /// let v: u8 = io.try_read(0xfff)?; /// /// Ok(()) /// } /// ``` #[inline(always)] fn try_read<T, L>(&self, location: L) -> Result<T> where L: IoLoc<T>, Self: IoCapable<L::IoType>, { let address = self.io_addr::<L::IoType>(location.offset())?; // SAFETY: `address` has been validated by `io_addr`. Ok(unsafe { self.io_read(address) }.into()) } /// Generic fallible write with runtime bounds check. /// /// # Examples /// /// Write a primitive type to an I/O address: /// /// ```no_run /// use kernel::io::{ /// Io, /// Mmio, /// }; /// /// fn do_writes(io: &Mmio) -> Result { /// // 32-bit write of value `1` at address `0x10`. /// io.try_write(0x10, 1u32)?; /// /// // 8-bit write of value `0xff` at address `0xfff`. /// io.try_write(0xfff, 0xffu8)?; /// /// Ok(()) /// } /// ``` #[inline(always)] fn try_write<T, L>(&self, location: L, value: T) -> Result where L: IoLoc<T>, Self: IoCapable<L::IoType>, { let address = self.io_addr::<L::IoType>(location.offset())?; let io_value = value.into(); // SAFETY: `address` has been validated by `io_addr`. unsafe { self.io_write(io_value, address) } Ok(()) } /// Generic fallible write of a fully-located register value. /// /// # Examples /// /// Tuples carrying a location and a value can be used with this method: /// /// ```no_run /// use kernel::io::{ /// register, /// Io, /// Mmio, /// }; /// /// register! { /// VERSION(u32) @ 0x100 { /// 15:8 major; /// 7:0 minor; /// } /// } /// /// impl VERSION { /// fn new(major: u8, minor: u8) -> Self { /// VERSION::zeroed().with_major(major).with_minor(minor)Lines 1–500 of 855. 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// 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 register; pub mod resource; pub use crate::register; pub use resource::Resource; use register::LocatedRegister; /// 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 /// `Mmio` instance providing the actual memory accessors. Only by the conversion into an `Mmio` /// structure any guarantees are given. pub struct MmioRaw<const SIZE: usize = 0> { addr: usize, maxsize: usize, } impl<const SIZE: usize> MmioRaw<SIZE> { /// Returns a new `MmioRaw` 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, /// IoKnownSize, /// Mmio, /// MmioRaw, /// PhysAddr, /// }, /// }; /// use core::ops::Deref; /// /// // See also `pci::Bar` for a real example. /// struct IoMem<const SIZE: usize>(MmioRaw<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(MmioRaw::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 = Mmio<SIZE>; /// /// fn deref(&self) -> &Self::Target { /// // SAFETY: The memory range stored in `self` has been properly mapped in `Self::new`. /// unsafe { Mmio::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 Mmio<const SIZE: usize = 0>(MmioRaw<SIZE>); /// Checks whether an access of type `U` at the given `offset` /// is valid within this region. #[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 } } /// Trait indicating that an I/O backend supports operations of a certain type and providing an /// implementation for these operations. /// /// Different I/O backends can implement this trait to expose only the operations they support. /// /// For example, a PCI configuration space may implement `IoCapable<u8>`, `IoCapable<u16>`, /// and `IoCapable<u32>`, but not `IoCapable<u64>`, while an MMIO region on a 64-bit /// system might implement all four. pub trait IoCapable<T> { /// Performs an I/O read of type `T` at `address` and returns the result. /// /// # Safety /// /// The range `[address..address + size_of::<T>()]` must be within the bounds of `Self`. unsafe fn io_read(&self, address: usize) -> T; /// Performs an I/O write of `value` at `address`. /// /// # Safety /// /// The range `[address..address + size_of::<T>()]` must be within the bounds of `Self`. unsafe fn io_write(&self, value: T, address: usize); } /// Describes a given I/O location: its offset, width, and type to convert the raw value from and /// into. /// /// This trait is the key abstraction allowing [`Io::read`], [`Io::write`], and [`Io::update`] (and /// their fallible [`try_read`](Io::try_read), [`try_write`](Io::try_write) and /// [`try_update`](Io::try_update) counterparts) to work uniformly with both raw [`usize`] offsets /// (for primitive types like [`u32`]) and typed ones (like those generated by the [`register!`] /// macro). /// /// An `IoLoc<T>` carries three pieces of information: /// /// - The offset to access (returned by [`IoLoc::offset`]), /// - The width of the access (determined by [`IoLoc::IoType`]), /// - The type `T` in which the raw data is returned or provided. /// /// `T` and `IoLoc::IoType` may differ: for instance, a typed register has `T` = the register type /// with its bitfields, and `IoType` = its backing primitive (e.g. `u32`). pub trait IoLoc<T> { /// Size ([`u8`], [`u16`], etc) of the I/O performed on the returned [`offset`](IoLoc::offset). type IoType: Into<T> + From<T>; /// Consumes `self` and returns the offset of this location. fn offset(self) -> usize; } /// Implements [`IoLoc<$ty>`] for [`usize`], allowing [`usize`] to be used as a parameter of /// [`Io::read`] and [`Io::write`]. macro_rules! impl_usize_ioloc { ($($ty:ty),*) => { $( impl IoLoc<$ty> for usize { type IoType = $ty; #[inline(always)] fn offset(self) -> usize { self } } )* } } // Provide the ability to read any primitive type from a [`usize`]. impl_usize_ioloc!(u8, u16, u32, u64); /// Types implementing this trait (e.g. MMIO BARs or PCI config regions) /// can perform I/O operations on regions of memory. /// /// This is an abstract representation to be implemented by arbitrary I/O /// backends (e.g. MMIO, PCI config space, etc.). /// /// The [`Io`] trait provides: /// - Base address and size information /// - Helper methods for offset validation and address calculation /// - Fallible (runtime checked) accessors for different data widths /// /// Which I/O methods are available depends on which [`IoCapable<T>`] traits /// are implemented for the type. /// /// # Examples /// /// For MMIO regions, all widths (u8, u16, u32, and u64 on 64-bit systems) are typically /// supported. For PCI configuration space, u8, u16, and u32 are supported but u64 is not. pub trait Io { /// Returns the base address of this mapping. fn addr(&self) -> usize; /// Returns the maximum size of this mapping. fn maxsize(&self) -> usize; /// Returns the absolute I/O address for a given `offset`, /// performing runtime bound checks. #[inline] fn io_addr<U>(&self, offset: usize) -> Result<usize> { if !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) } /// Fallible 8-bit read with runtime bounds check. #[inline(always)] fn try_read8(&self, offset: usize) -> Result<u8> where Self: IoCapable<u8>, { self.try_read(offset) } /// Fallible 16-bit read with runtime bounds check. #[inline(always)] fn try_read16(&self, offset: usize) -> Result<u16> where Self: IoCapable<u16>, { self.try_read(offset) } /// Fallible 32-bit read with runtime bounds check. #[inline(always)] fn try_read32(&self, offset: usize) -> Result<u32> where Self: IoCapable<u32>, { self.try_read(offset) } /// Fallible 64-bit read with runtime bounds check. #[inline(always)] fn try_read64(&self, offset: usize) -> Result<u64> where Self: IoCapable<u64>, { self.try_read(offset) } /// Fallible 8-bit write with runtime bounds check. #[inline(always)] fn try_write8(&self, value: u8, offset: usize) -> Result where Self: IoCapable<u8>, { self.try_write(offset, value) } /// Fallible 16-bit write with runtime bounds check. #[inline(always)] fn try_write16(&self, value: u16, offset: usize) -> Result where Self: IoCapable<u16>, { self.try_write(offset, value) } /// Fallible 32-bit write with runtime bounds check. #[inline(always)] fn try_write32(&self, value: u32, offset: usize) -> Result where Self: IoCapable<u32>, { self.try_write(offset, value) } /// Fallible 64-bit write with runtime bounds check. #[inline(always)] fn try_write64(&self, value: u64, offset: usize) -> Result where Self: IoCapable<u64>, { self.try_write(offset, value) } /// Infallible 8-bit read with compile-time bounds check. #[inline(always)] fn read8(&self, offset: usize) -> u8 where Self: IoKnownSize + IoCapable<u8>, { self.read(offset) } /// Infallible 16-bit read with compile-time bounds check. #[inline(always)] fn read16(&self, offset: usize) -> u16 where Self: IoKnownSize + IoCapable<u16>, { self.read(offset) } /// Infallible 32-bit read with compile-time bounds check. #[inline(always)] fn read32(&self, offset: usize) -> u32 where Self: IoKnownSize + IoCapable<u32>, { self.read(offset) } /// Infallible 64-bit read with compile-time bounds check. #[inline(always)] fn read64(&self, offset: usize) -> u64 where Self: IoKnownSize + IoCapable<u64>, { self.read(offset) } /// Infallible 8-bit write with compile-time bounds check. #[inline(always)] fn write8(&self, value: u8, offset: usize) where Self: IoKnownSize + IoCapable<u8>, { self.write(offset, value) } /// Infallible 16-bit write with compile-time bounds check. #[inline(always)] fn write16(&self, value: u16, offset: usize) where Self: IoKnownSize + IoCapable<u16>, { self.write(offset, value) } /// Infallible 32-bit write with compile-time bounds check. #[inline(always)] fn write32(&self, value: u32, offset: usize) where Self: IoKnownSize + IoCapable<u32>, { self.write(offset, value) } /// Infallible 64-bit write with compile-time bounds check. #[inline(always)] fn write64(&self, value: u64, offset: usize) where Self: IoKnownSize + IoCapable<u64>, { self.write(offset, value) } /// Generic fallible read with runtime bounds check. /// /// # Examples /// /// Read a primitive type from an I/O address: /// /// ```no_run /// use kernel::io::{ /// Io, /// Mmio, /// }; /// /// fn do_reads(io: &Mmio) -> Result { /// // 32-bit read from address `0x10`. /// let v: u32 = io.try_read(0x10)?; /// /// // 8-bit read from address `0xfff`. /// let v: u8 = io.try_read(0xfff)?; /// /// Ok(()) /// } /// ``` #[inline(always)] fn try_read<T, L>(&self, location: L) -> Result<T> where L: IoLoc<T>, Self: IoCapable<L::IoType>, { let address = self.io_addr::<L::IoType>(location.offset())?; // SAFETY: `address` has been validated by `io_addr`. Ok(unsafe { self.io_read(address) }.into()) } /// Generic fallible write with runtime bounds check. /// /// # Examples /// /// Write a primitive type to an I/O address: /// /// ```no_run /// use kernel::io::{ /// Io, /// Mmio, /// }; /// /// fn do_writes(io: &Mmio) -> Result { /// // 32-bit write of value `1` at address `0x10`. /// io.try_write(0x10, 1u32)?; /// /// // 8-bit write of value `0xff` at address `0xfff`. /// io.try_write(0xfff, 0xffu8)?; /// /// Ok(()) /// } /// ``` #[inline(always)] fn try_write<T, L>(&self, location: L, value: T) -> Result where L: IoLoc<T>, Self: IoCapable<L::IoType>, { let address = self.io_addr::<L::IoType>(location.offset())?; let io_value = value.into(); // SAFETY: `address` has been validated by `io_addr`. unsafe { self.io_write(io_value, address) } Ok(()) } /// Generic fallible write of a fully-located register value. /// /// # Examples /// /// Tuples carrying a location and a value can be used with this method: /// /// ```no_run /// use kernel::io::{ /// register, /// Io, /// Mmio, /// }; /// /// register! { /// VERSION(u32) @ 0x100 { /// 15:8 major; /// 7:0 minor; /// } /// } /// /// impl VERSION { /// fn new(major: u8, minor: u8) -> Self { /// VERSION::zeroed().with_major(major).with_minor(minor)