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13 daysrust: io: mem: add a generic iomem abstractionDaniel Almeida
Add a generic iomem abstraction to safely read and write ioremapped regions. This abstraction requires a previously acquired IoRequest instance. This makes it so that both the resource and the device match, or, in other words, that the resource is indeed a valid resource for a given bound device. A subsequent patch will add the ability to retrieve IoRequest instances from platform devices. The reads and writes are done through IoRaw, and are thus checked either at compile-time, if the size of the region is known at that point, or at runtime otherwise. Non-exclusive access to the underlying memory region is made possible to cater to cases where overlapped regions are unavoidable. Acked-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com> Link: https://lore.kernel.org/r/20250717-topics-tyr-platform_iomem-v15-2-beca780b77e3@collabora.com [ Add #[expect(dead_code)] to avoid a temporary warning, remove unnecessary OF_ID_TABLE constants in doc-tests and ignore doc-tests for now to avoid a temporary build failure. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
13 daysrust: io: add resource abstractionDaniel Almeida
In preparation for ioremap support, add a Rust abstraction for struct resource. A future commit will introduce the Rust API to ioremap a resource from a platform device. The current abstraction, therefore, adds only the minimum API needed to get that done. Acked-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Co-developed-by: Fiona Behrens <me@kloenk.dev> Signed-off-by: Fiona Behrens <me@kloenk.dev> Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com> Link: https://lore.kernel.org/r/20250717-topics-tyr-platform_iomem-v15-1-beca780b77e3@collabora.com [ Capitalize safety comments and end it with a period. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-02-22rust: io: rename `io::Io` accessorsFiona Behrens
Rename the I/O accessors provided by `Io` to encode the type as number instead of letter. This is in preparation for Port I/O support to use a trait for generic accessors. Add a `c_fn` argument to the accessor generation macro to translate between rust and C names. Suggested-by: Danilo Krummrich <dakr@kernel.org> Link: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/PIO.20support/near/499460541 Signed-off-by: Fiona Behrens <me@kloenk.dev> Acked-by: Danilo Krummrich <dakr@kernel.org> Acked-by: Daniel Almeida <daniel.almeida@collabora.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20250217-io-generic-rename-v1-1-06d97a9e3179@kloenk.dev Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-20rust: add `io::{Io, IoRaw}` base typesDanilo Krummrich
I/O memory is typically either mapped through direct calls to ioremap() or subsystem / bus specific ones such as pci_iomap(). Even though subsystem / bus specific functions to map I/O memory are based on ioremap() / iounmap() it is not desirable to re-implement them in Rust. Instead, implement a base type for I/O mapped memory, which generically provides the corresponding accessors, such as `Io::readb` or `Io:try_readb`. `Io` supports an optional const generic, such that a driver can indicate the minimal expected and required size of the mapping at compile time. Correspondingly, calls to the 'non-try' accessors, support compile time checks of the I/O memory offset to read / write, while the 'try' accessors, provide boundary checks on runtime. `IoRaw` is meant to be embedded into a structure (e.g. pci::Bar or io::IoMem) which creates the actual I/O memory mapping and initializes `IoRaw` accordingly. To ensure that I/O mapped memory can't out-live the device it may be bound to, subsystems must embed the corresponding I/O memory type (e.g. pci::Bar) into a `Devres` container, such that it gets revoked once the device is unbound. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Tested-by: Daniel Almeida <daniel.almeida@collabora.com> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Tested-by: Dirk Behme <dirk.behme@de.bosch.com> Link: https://lore.kernel.org/r/20241219170425.12036-8-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>