From 6461c5776bf0f546cfeaf2a72f1a2f7de27bfe0d Mon Sep 17 00:00:00 2001 From: Gary Guo Date: Mon, 6 Jul 2026 13:44:16 +0100 Subject: rust: io: restrict untyped IO access and `register!` to `Region` Currently the `Io` trait exposes a bunch of untyped IO accesses, but if the `Io` region itself is typed, then it might be weird to have let io: Mmio = /* ... */; io.read8(1); while not unsound, it is surely strange. Thus, restrict the untyped methods and also the register macro to `Region` type only. Implement it by adding a generic type to `IoLoc` indicating allowed base types. This also paves the way to add typed register blocks in the future; for example, we could use this mechanism to block driver A's `register!()` generated macro from being used on driver B's MMIO. The same mechanism could be used for relative IO registers. These are future opportunities, and for now restrict everything to require `IoLoc, _>`. Suggested-by: Alexandre Courbot Link: https://lore.kernel.org/rust-for-linux/DHLB3RO3OSF5.2R7F27U99BKLN@nvidia.com/ Reviewed-by: Alexandre Courbot Signed-off-by: Gary Guo Reviewed-by: Daniel Almeida Link: https://patch.msgid.link/20260706-io_projection-v6-3-72cd5d055d54@garyguo.net Signed-off-by: Danilo Krummrich --- rust/kernel/io/register.rs | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) (limited to 'rust/kernel/io') diff --git a/rust/kernel/io/register.rs b/rust/kernel/io/register.rs index f924c7c7c1db..3122b17098ee 100644 --- a/rust/kernel/io/register.rs +++ b/rust/kernel/io/register.rs @@ -113,6 +113,8 @@ use crate::{ io::IoLoc, // }; +use super::Region; + /// Trait implemented by all registers. pub trait Register: Sized { /// Backing primitive type of the register. @@ -129,7 +131,7 @@ pub trait FixedRegister: Register {} /// Allows `()` to be used as the `location` parameter of [`Io::write`](super::Io::write) when /// passing a [`FixedRegister`] value. -impl IoLoc for () +impl IoLoc, T> for () where T: FixedRegister, { @@ -143,7 +145,7 @@ where /// A [`FixedRegister`] carries its location in its type. Thus `FixedRegister` values can be used /// as an [`IoLoc`]. -impl IoLoc for T +impl IoLoc, T> for T where T: FixedRegister, { @@ -168,7 +170,7 @@ impl FixedRegisterLoc { } } -impl IoLoc for FixedRegisterLoc +impl IoLoc, T> for FixedRegisterLoc where T: FixedRegister, { @@ -239,7 +241,7 @@ where } } -impl IoLoc for RelativeRegisterLoc +impl IoLoc, T> for RelativeRegisterLoc where T: RelativeRegister, B: RegisterBase + ?Sized, @@ -283,7 +285,7 @@ impl RegisterArrayLoc { } } -impl IoLoc for RegisterArrayLoc +impl IoLoc, T> for RegisterArrayLoc where T: RegisterArray, { @@ -370,7 +372,7 @@ where } } -impl IoLoc for RelativeRegisterArrayLoc +impl IoLoc, T> for RelativeRegisterArrayLoc where T: RelativeRegisterArray, B: RegisterBase + ?Sized, @@ -387,18 +389,18 @@ where /// which to write it. /// /// Implementors can be used with [`Io::write_reg`](super::Io::write_reg). -pub trait LocatedRegister { +pub trait LocatedRegister { /// Register value to write. type Value: Register; /// Full location information at which to write the value. - type Location: IoLoc; + type Location: IoLoc; /// Consumes `self` and returns a `(location, value)` tuple describing a valid I/O write /// operation. fn into_io_op(self) -> (Self::Location, Self::Value); } -impl LocatedRegister for T +impl LocatedRegister> for T where T: FixedRegister, { -- cgit v1.2.3 From 9734e905119c5f7d7af9dd3e483f9a0d9ee12187 Mon Sep 17 00:00:00 2001 From: Gary Guo Date: Mon, 6 Jul 2026 13:44:18 +0100 Subject: rust: io: generalize `MmioRaw` to pointer to arbitrary type Conceptually, `MmioRaw` is just `__iomem *`, so it should work for any types. Update the existing use case where it represents a region of compile-time known minimum size and run-time known actual size to use the dynamic-sized type `Region` instead. Rename `maxsize` method to reflect that it is the actual size (not a bound) of the region. Implement `Clone` and `Copy` manually, which cannot be derived due to the generic parameter. The use of raw pointers also cause the `Send` and `Sync` auto trait implementation to be lost, so add them back by manual implementation. Reviewed-by: Alexandre Courbot Signed-off-by: Gary Guo Reviewed-by: Daniel Almeida Suggested-by: Danilo Krummrich Link: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/Generic.20I.2FO.20backends/near/571198078 Link: https://patch.msgid.link/20260706-io_projection-v6-5-72cd5d055d54@garyguo.net Signed-off-by: Danilo Krummrich --- rust/kernel/io/mem.rs | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'rust/kernel/io') diff --git a/rust/kernel/io/mem.rs b/rust/kernel/io/mem.rs index fc2a3e24f8d5..9e15bc8fde78 100644 --- a/rust/kernel/io/mem.rs +++ b/rust/kernel/io/mem.rs @@ -229,7 +229,7 @@ impl Deref for ExclusiveIoMem<'_, SIZE> { /// start of the I/O memory mapped region. pub struct IoMem<'a, const SIZE: usize = 0> { dev: &'a Device, - io: MmioRaw, + io: MmioRaw>, } impl<'a, const SIZE: usize> IoMem<'a, SIZE> { @@ -264,8 +264,7 @@ impl<'a, const SIZE: usize> IoMem<'a, SIZE> { return Err(ENOMEM); } - let io = MmioRaw::new(addr as usize, size)?; - + let io = MmioRaw::new_region(addr as usize, size)?; Ok(IoMem { dev, io }) } -- cgit v1.2.3 From 691c75967d44bef006e4d4e783baa88470b33ea5 Mon Sep 17 00:00:00 2001 From: Gary Guo Date: Mon, 6 Jul 2026 13:44:19 +0100 Subject: rust: io: rename `Mmio` to `MmioOwned` Most users would more commonly reach out to a view of `Mmio` rather than an owned instance of `Mmio`. Only implementor of `Io` like `Bar` or `IoMem` would need the owned version. Thus, rename `Mmio` to `MmioOwned` so that the name `Mmio` can be used for the view type instead. Reviewed-by: Alexandre Courbot Signed-off-by: Gary Guo Reviewed-by: Daniel Almeida Suggested-by: Danilo Krummrich Link: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/Generic.20I.2FO.20backends/near/571198078 Link: https://patch.msgid.link/20260706-io_projection-v6-6-72cd5d055d54@garyguo.net Signed-off-by: Danilo Krummrich --- rust/kernel/io/mem.rs | 8 ++++---- rust/kernel/io/poll.rs | 8 ++++---- rust/kernel/io/register.rs | 24 ++++++++++++------------ 3 files changed, 20 insertions(+), 20 deletions(-) (limited to 'rust/kernel/io') diff --git a/rust/kernel/io/mem.rs b/rust/kernel/io/mem.rs index 9e15bc8fde78..8f6c257c5b8e 100644 --- a/rust/kernel/io/mem.rs +++ b/rust/kernel/io/mem.rs @@ -16,7 +16,7 @@ use crate::{ Region, Resource, // }, - Mmio, + MmioOwned, MmioRaw, // }, prelude::*, @@ -211,7 +211,7 @@ impl<'a, const SIZE: usize> ExclusiveIoMem<'a, SIZE> { } impl Deref for ExclusiveIoMem<'_, SIZE> { - type Target = Mmio; + type Target = MmioOwned; fn deref(&self) -> &Self::Target { &self.iomem @@ -291,10 +291,10 @@ impl Drop for IoMem<'_, SIZE> { } impl Deref for IoMem<'_, SIZE> { - type Target = Mmio; + type Target = MmioOwned; fn deref(&self) -> &Self::Target { // SAFETY: Safe as by the invariant of `IoMem`. - unsafe { Mmio::from_raw(&self.io) } + unsafe { MmioOwned::from_raw(&self.io) } } } diff --git a/rust/kernel/io/poll.rs b/rust/kernel/io/poll.rs index 75d1b3e8596c..79828a8006b5 100644 --- a/rust/kernel/io/poll.rs +++ b/rust/kernel/io/poll.rs @@ -47,14 +47,14 @@ use crate::{ /// ```no_run /// use kernel::io::{ /// Io, -/// Mmio, +/// MmioOwned, /// poll::read_poll_timeout, // /// }; /// use kernel::time::Delta; /// /// const HW_READY: u16 = 0x01; /// -/// fn wait_for_hardware(io: &Mmio) -> Result { +/// fn wait_for_hardware(io: &MmioOwned) -> Result { /// read_poll_timeout( /// // The `op` closure reads the value of a specific status register. /// || io.try_read16(0x1000), @@ -134,14 +134,14 @@ where /// ```no_run /// use kernel::io::{ /// Io, -/// Mmio, +/// MmioOwned, /// poll::read_poll_timeout_atomic, // /// }; /// use kernel::time::Delta; /// /// const HW_READY: u16 = 0x01; /// -/// fn wait_for_hardware(io: &Mmio) -> Result { +/// fn wait_for_hardware(io: &MmioOwned) -> Result { /// read_poll_timeout_atomic( /// // The `op` closure reads the value of a specific status register. /// || io.try_read16(0x1000), diff --git a/rust/kernel/io/register.rs b/rust/kernel/io/register.rs index 3122b17098ee..43284d9fba96 100644 --- a/rust/kernel/io/register.rs +++ b/rust/kernel/io/register.rs @@ -58,7 +58,7 @@ //! }, //! num::Bounded, //! }; -//! # use kernel::io::Mmio; +//! # use kernel::io::MmioOwned; //! # register! { //! # pub BOOT_0(u32) @ 0x00000100 { //! # 15:8 vendor_id; @@ -66,7 +66,7 @@ //! # 3:0 minor_revision; //! # } //! # } -//! # fn test(io: &Mmio<0x1000>) { +//! # fn test(io: &MmioOwned<0x1000>) { //! # fn obtain_vendor_id() -> u8 { 0xff } //! //! // Read from the register's defined offset (0x100). @@ -446,7 +446,7 @@ where /// Io, /// }, /// }; -/// # use kernel::io::Mmio; +/// # use kernel::io::MmioOwned; /// /// register! { /// FIXED_REG(u32) @ 0x100 { @@ -455,7 +455,7 @@ where /// } /// } /// -/// # fn test(io: &Mmio<0x1000>) { +/// # fn test(io: &MmioOwned<0x1000>) { /// let val = io.read(FIXED_REG); /// /// // Write from an already-existing value. @@ -559,7 +559,7 @@ where /// Io, /// }, /// }; -/// # use kernel::io::Mmio; +/// # use kernel::io::MmioOwned; /// /// // Type used to identify the base. /// pub struct CpuCtlBase; @@ -584,7 +584,7 @@ where /// } /// } /// -/// # fn test(io: Mmio<0x1000>) { +/// # fn test(io: MmioOwned<0x1000>) { /// // Read the status of `Cpu0`. /// let cpu0_started = io.read(CPU_CTL::of::()); /// @@ -601,7 +601,7 @@ where /// } /// } /// -/// # fn test2(io: Mmio<0x1000>) { +/// # fn test2(io: MmioOwned<0x1000>) { /// // Start the aliased `CPU0`, leaving its other fields untouched. /// io.update(CPU_CTL_ALIAS::of::(), |r| r.with_alias_start(true)); /// # } @@ -638,7 +638,7 @@ where /// Io, /// }, /// }; -/// # use kernel::io::Mmio; +/// # use kernel::io::MmioOwned; /// # fn get_scratch_idx() -> usize { /// # 0x15 /// # } @@ -651,7 +651,7 @@ where /// } /// } /// -/// # fn test(io: &Mmio<0x1000>) +/// # fn test(io: &MmioOwned<0x1000>) /// # -> Result<(), Error>{ /// // Read scratch register 0, i.e. I/O address `0x80`. /// let scratch_0 = io.read(SCRATCH::at(0)).value(); @@ -724,7 +724,7 @@ where /// Io, /// }, /// }; -/// # use kernel::io::Mmio; +/// # use kernel::io::MmioOwned; /// # fn get_scratch_idx() -> usize { /// # 0x15 /// # } @@ -752,7 +752,7 @@ where /// } /// } /// -/// # fn test(io: &Mmio<0x1000>) -> Result<(), Error> { +/// # fn test(io: &MmioOwned<0x1000>) -> Result<(), Error> { /// // Read scratch register 0 of CPU0. /// let scratch = io.read(CPU_SCRATCH::of::().at(0)); /// @@ -794,7 +794,7 @@ where /// } /// } /// -/// # fn test2(io: &Mmio<0x1000>) -> Result<(), Error> { +/// # fn test2(io: &MmioOwned<0x1000>) -> Result<(), Error> { /// let cpu0_status = io.read(CPU_FIRMWARE_STATUS::of::()).status(); /// # Ok(()) /// # } -- cgit v1.2.3 From 9f64c84af008b8e01309ec6fe04bc772fbf23ea5 Mon Sep 17 00:00:00 2001 From: Gary Guo Date: Mon, 6 Jul 2026 13:44:20 +0100 Subject: rust: io: implement `Mmio` as view type Implement `Mmio` as view type and convert `RelaxedMmio` to view type as well. I/O implementations of `MmioOwned` are changed to delegate to the `Mmio` view type. All existing users of `MmioOwned` in the documentation which do not actually reflect the owning semantics is converted. Reviewed-by: Alexandre Courbot Signed-off-by: Gary Guo Tested-by: Daniel Almeida Reviewed-by: Daniel Almeida Link: https://patch.msgid.link/20260706-io_projection-v6-7-72cd5d055d54@garyguo.net Signed-off-by: Danilo Krummrich --- rust/kernel/io/poll.rs | 10 ++++++---- rust/kernel/io/register.rs | 24 ++++++++++++------------ 2 files changed, 18 insertions(+), 16 deletions(-) (limited to 'rust/kernel/io') diff --git a/rust/kernel/io/poll.rs b/rust/kernel/io/poll.rs index 79828a8006b5..d75f2fcf46f2 100644 --- a/rust/kernel/io/poll.rs +++ b/rust/kernel/io/poll.rs @@ -47,14 +47,15 @@ use crate::{ /// ```no_run /// use kernel::io::{ /// Io, -/// MmioOwned, +/// Mmio, +/// Region, /// poll::read_poll_timeout, // /// }; /// use kernel::time::Delta; /// /// const HW_READY: u16 = 0x01; /// -/// fn wait_for_hardware(io: &MmioOwned) -> Result { +/// fn wait_for_hardware(io: Mmio<'_, Region>) -> Result { /// read_poll_timeout( /// // The `op` closure reads the value of a specific status register. /// || io.try_read16(0x1000), @@ -134,14 +135,15 @@ where /// ```no_run /// use kernel::io::{ /// Io, -/// MmioOwned, +/// Mmio, +/// Region, /// poll::read_poll_timeout_atomic, // /// }; /// use kernel::time::Delta; /// /// const HW_READY: u16 = 0x01; /// -/// fn wait_for_hardware(io: &MmioOwned) -> Result { +/// fn wait_for_hardware(io: Mmio<'_, Region>) -> Result { /// read_poll_timeout_atomic( /// // The `op` closure reads the value of a specific status register. /// || io.try_read16(0x1000), diff --git a/rust/kernel/io/register.rs b/rust/kernel/io/register.rs index 43284d9fba96..80e638a892d7 100644 --- a/rust/kernel/io/register.rs +++ b/rust/kernel/io/register.rs @@ -58,7 +58,7 @@ //! }, //! num::Bounded, //! }; -//! # use kernel::io::MmioOwned; +//! # use kernel::io::{Mmio, Region}; //! # register! { //! # pub BOOT_0(u32) @ 0x00000100 { //! # 15:8 vendor_id; @@ -66,7 +66,7 @@ //! # 3:0 minor_revision; //! # } //! # } -//! # fn test(io: &MmioOwned<0x1000>) { +//! # fn test(io: Mmio<'_, Region<0x1000>>) { //! # fn obtain_vendor_id() -> u8 { 0xff } //! //! // Read from the register's defined offset (0x100). @@ -446,7 +446,7 @@ where /// Io, /// }, /// }; -/// # use kernel::io::MmioOwned; +/// # use kernel::io::{Mmio, Region}; /// /// register! { /// FIXED_REG(u32) @ 0x100 { @@ -455,7 +455,7 @@ where /// } /// } /// -/// # fn test(io: &MmioOwned<0x1000>) { +/// # fn test(io: Mmio<'_, Region<0x1000>>) { /// let val = io.read(FIXED_REG); /// /// // Write from an already-existing value. @@ -559,7 +559,7 @@ where /// Io, /// }, /// }; -/// # use kernel::io::MmioOwned; +/// # use kernel::io::{Mmio, Region}; /// /// // Type used to identify the base. /// pub struct CpuCtlBase; @@ -584,7 +584,7 @@ where /// } /// } /// -/// # fn test(io: MmioOwned<0x1000>) { +/// # fn test(io: Mmio<'_, Region<0x1000>>) { /// // Read the status of `Cpu0`. /// let cpu0_started = io.read(CPU_CTL::of::()); /// @@ -601,7 +601,7 @@ where /// } /// } /// -/// # fn test2(io: MmioOwned<0x1000>) { +/// # fn test2(io: Mmio<'_, Region<0x1000>>) { /// // Start the aliased `CPU0`, leaving its other fields untouched. /// io.update(CPU_CTL_ALIAS::of::(), |r| r.with_alias_start(true)); /// # } @@ -638,7 +638,7 @@ where /// Io, /// }, /// }; -/// # use kernel::io::MmioOwned; +/// # use kernel::io::{Mmio, Region}; /// # fn get_scratch_idx() -> usize { /// # 0x15 /// # } @@ -651,7 +651,7 @@ where /// } /// } /// -/// # fn test(io: &MmioOwned<0x1000>) +/// # fn test(io: Mmio<'_, Region<0x1000>>) /// # -> Result<(), Error>{ /// // Read scratch register 0, i.e. I/O address `0x80`. /// let scratch_0 = io.read(SCRATCH::at(0)).value(); @@ -724,7 +724,7 @@ where /// Io, /// }, /// }; -/// # use kernel::io::MmioOwned; +/// # use kernel::io::{Mmio, Region}; /// # fn get_scratch_idx() -> usize { /// # 0x15 /// # } @@ -752,7 +752,7 @@ where /// } /// } /// -/// # fn test(io: &MmioOwned<0x1000>) -> Result<(), Error> { +/// # fn test(io: Mmio<'_, Region<0x1000>>) -> Result<(), Error> { /// // Read scratch register 0 of CPU0. /// let scratch = io.read(CPU_SCRATCH::of::().at(0)); /// @@ -794,7 +794,7 @@ where /// } /// } /// -/// # fn test2(io: &MmioOwned<0x1000>) -> Result<(), Error> { +/// # fn test2(io: Mmio<'_, Region<0x1000>>) -> Result<(), Error> { /// let cpu0_status = io.read(CPU_FIRMWARE_STATUS::of::()).status(); /// # Ok(()) /// # } -- cgit v1.2.3 From bed01ca9e9cf8f8fea5352c07fa206cc3c106045 Mon Sep 17 00:00:00 2001 From: Gary Guo Date: Mon, 6 Jul 2026 13:44:24 +0100 Subject: rust: io: remove `MmioOwned` `Io` trait is now very easy to implement. Thus, implement it on `Bar` and `IoMem` directly and remove the `MmioOwned` struct. Reviewed-by: Alexandre Courbot Signed-off-by: Gary Guo Reviewed-by: Daniel Almeida Suggested-by: Danilo Krummrich Link: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/Generic.20I.2FO.20backends/near/571198078 Link: https://patch.msgid.link/20260706-io_projection-v6-11-72cd5d055d54@garyguo.net Signed-off-by: Danilo Krummrich --- rust/kernel/io/mem.rs | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) (limited to 'rust/kernel/io') diff --git a/rust/kernel/io/mem.rs b/rust/kernel/io/mem.rs index 8f6c257c5b8e..d9b3189d09b4 100644 --- a/rust/kernel/io/mem.rs +++ b/rust/kernel/io/mem.rs @@ -2,8 +2,6 @@ //! Generic memory-mapped IO. -use core::ops::Deref; - use crate::{ device::{ Bound, @@ -16,7 +14,9 @@ use crate::{ Region, Resource, // }, - MmioOwned, + Io, + Mmio, + MmioBackend, MmioRaw, // }, prelude::*, @@ -210,11 +210,13 @@ impl<'a, const SIZE: usize> ExclusiveIoMem<'a, SIZE> { } } -impl Deref for ExclusiveIoMem<'_, SIZE> { - type Target = MmioOwned; +impl<'a, const SIZE: usize> Io<'a> for &'a ExclusiveIoMem<'_, SIZE> { + type Backend = MmioBackend; + type Target = super::Region; - fn deref(&self) -> &Self::Target { - &self.iomem + #[inline] + fn as_view(self) -> Mmio<'a, Self::Target> { + self.iomem.as_view() } } @@ -290,11 +292,13 @@ impl Drop for IoMem<'_, SIZE> { } } -impl Deref for IoMem<'_, SIZE> { - type Target = MmioOwned; +impl<'a, const SIZE: usize> Io<'a> for &'a IoMem<'_, SIZE> { + type Backend = MmioBackend; + type Target = super::Region; - fn deref(&self) -> &Self::Target { + #[inline] + fn as_view(self) -> Mmio<'a, Self::Target> { // SAFETY: Safe as by the invariant of `IoMem`. - unsafe { MmioOwned::from_raw(&self.io) } + unsafe { Mmio::from_raw(self.io) } } } -- cgit v1.2.3 From 9b36c13cbd4fb761212b1ea9a2e89f7df2d3c9f8 Mon Sep 17 00:00:00 2001 From: Gary Guo Date: Mon, 6 Jul 2026 13:44:25 +0100 Subject: rust: io: move `Io` methods to extension trait `Io` trait now has a single required method with many more provided methods. Provided methods may want to rely on their implementations to not be arbitrarily overridden by implementers for correctness or soundness. A good example is the `size` method, it may be relied by unsafe code and thus must be consistent with the metadata obtained from `as_ptr`. Thus, create a new trait to host `size` method, extract existing provided methods to the new trait, and provide a blanket implementation. This pattern is used extensively in userspace Rust libraries e.g. `tokio` where `AsyncRead` has minimum methods and `AsyncReadExt` is what users mostly interact with. To avoid changing all user imports, the base trait is renamed to `IoBase` and the newly added trait takes the existing `Io` name. Reviewed-by: Alexandre Courbot Suggested-by: Danilo Krummrich Signed-off-by: Gary Guo Reviewed-by: Daniel Almeida Link: https://patch.msgid.link/20260706-io_projection-v6-12-72cd5d055d54@garyguo.net [ Add comment explaining the purpose of the Io blanket implementation. - Danilo ] Signed-off-by: Danilo Krummrich --- rust/kernel/io/mem.rs | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'rust/kernel/io') diff --git a/rust/kernel/io/mem.rs b/rust/kernel/io/mem.rs index d9b3189d09b4..e95b769ebe47 100644 --- a/rust/kernel/io/mem.rs +++ b/rust/kernel/io/mem.rs @@ -14,7 +14,7 @@ use crate::{ Region, Resource, // }, - Io, + IoBase, Mmio, MmioBackend, MmioRaw, // @@ -210,7 +210,7 @@ impl<'a, const SIZE: usize> ExclusiveIoMem<'a, SIZE> { } } -impl<'a, const SIZE: usize> Io<'a> for &'a ExclusiveIoMem<'_, SIZE> { +impl<'a, const SIZE: usize> IoBase<'a> for &'a ExclusiveIoMem<'_, SIZE> { type Backend = MmioBackend; type Target = super::Region; @@ -292,7 +292,7 @@ impl Drop for IoMem<'_, SIZE> { } } -impl<'a, const SIZE: usize> Io<'a> for &'a IoMem<'_, SIZE> { +impl<'a, const SIZE: usize> IoBase<'a> for &'a IoMem<'_, SIZE> { type Backend = MmioBackend; type Target = super::Region; -- cgit v1.2.3