linux.git/rust/kernel/pci/io.rs, branch v7.2

rust: pci: make Bar lifetime-parameterized

2026-05-27T14:24:23+00:00

Convert pci::Bar to pci::Bar<'a, SIZE>, storing &'a Device
to tie the BAR mapping lifetime to the device.

iomap_region_sized() now returns Result> directly instead
of impl PinInit>, Error>.

Since the lifetime ties the mapping to the device's bound state, callers
no longer need Devres for the common case where the Bar lives in the
driver's private data.

Add Bar::into_devres() to consume the bar and register it as a
device-managed resource, returning Devres>. The
lifetime is erased to 'static because Devres guarantees the bar does not
actually outlive the device -- access is revoked on unbind.

Reviewed-by: Eliot Courtney 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Alexandre Courbot 
Reviewed-by: Gary Guo 
Link: https://patch.msgid.link/20260525202921.124698-19-dakr@kernel.org
Signed-off-by: Danilo Krummrich

rust: pci: use 'static lifetime for PCI BAR resource names

2026-05-27T14:22:28+00:00

pci_request_region() stores the name pointer directly in struct
resource; use &'static CStr to ensure the pointer remains valid even if
the Bar is leaked.

Cc: stable@vger.kernel.org
Reported-by: Sashiko 
Closes: https://lore.kernel.org/all/20260522004943.CDA7C1F000E9@smtp.kernel.org/
Fixes: 3c2e31d717ac ("rust: pci: move I/O infrastructure to separate file")
Reviewed-by: Alexandre Courbot 
Reviewed-by: Eliot Courtney 
Reviewed-by: Gary Guo 
Link: https://patch.msgid.link/20260525202921.124698-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich

rust: pci: io: remove overloaded Io methods of ConfigSpace

2026-03-17T19:02:09+00:00

Since `ConfigSpace` now has the relevant implementations of `IoCapable`,
the default methods of `Io` can be used in place of the overloaded ones.
Remove them as well as the macros generating them.

Reviewed-by: Daniel Almeida 
Acked-by: Alice Ryhl 
Signed-off-by: Alexandre Courbot 
Reviewed-by: Gary Guo 
Link: https://patch.msgid.link/20260206-io-v2-5-71dea20a06e6@nvidia.com
Signed-off-by: Danilo Krummrich

rust: io: turn IoCapable into a functional trait

2026-03-17T19:02:09+00:00

`IoCapable` is currently used as a marker trait to signal that the
methods of the `Io` trait corresponding to `T` have been overridden by
the implementor (the default implementations triggering a build-time
error).

This goes against the DRY principle and separates the signaling of the
capability from its implementation, making it possible to forget a step
while implementing a new `Io`.

Another undesirable side-effect is that it makes the implementation of
I/O backends boilerplate-y and convoluted: currently this is done using
two levels of imbricated macros that generate unsafe code.

Fix these issues by turning `IoCapable` into a functional trait that
includes the raw implementation of the I/O access for `T` using
unsafe methods that work with an arbitrary address.

This allows us to turn the default methods of `Io` into regular methods
that check the passed offset, turn it into an address, and call into the
corresponding `IoCapable` functions, removing the need to overload them
at all.

`IoCapable` must still be implemented for all supported primitive types,
which is still done more concisely using a macro, but this macro becomes
much simpler and does not require calling into another one.

Reviewed-by: Daniel Almeida 
Acked-by: Alice Ryhl 
Signed-off-by: Alexandre Courbot 
Reviewed-by: Gary Guo 
Link: https://patch.msgid.link/20260206-io-v2-1-71dea20a06e6@nvidia.com
Signed-off-by: Danilo Krummrich

rust: io: macro_export io_define_read!() and io_define_write!()

2026-02-22T23:54:02+00:00

Currently, the define_read!() and define_write!() I/O macros are crate
public. The only user outside of the I/O module is PCI (for the
configurations space I/O backend). Consequently, when CONFIG_PCI=n this
causes a compile time warning [1].

In order to fix this, rename the macros to io_define_read!() and
io_define_write!() and use #[macro_export] to export them.

This is better than making the crate public visibility conditional, as
eventually subsystems will have their own crate.

Also, I/O backends are valid to be implemented by drivers as well. For
instance, there are devices (such as GPUs) that run firmware which
allows to program other devices only accessible through the primary
device through indirect I/O.

Since the macros are now public, also add the corresponding
documentation.

Fixes: 121d87b28e1d ("rust: io: separate generic I/O helpers from MMIO implementation")
Reported-by: Miguel Ojeda 
Closes: https://lore.kernel.org/driver-core/CANiq72khOYkt6t5zwMvSiyZvWWHMZuNCMERXu=7K=_5tT-8Pgg@mail.gmail.com/ [1]
Reviewed-by: Alice Ryhl 
Reviewed-by: Daniel Almeida 
Link: https://patch.msgid.link/20260216131534.65008-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich

rust: io: move MIN_SIZE and io_addr_assert to IoKnownSize

2026-02-01T21:23:59+00:00

`MIN_SIZE` and `io_addr_assert` are only ever used for IO types which
implement `IoKnownSize` and do not make sense for types that don't.

It looks like they should have been there since the beginning, so move
them while the code is still fresh.

Also update `IoKnownSize`'s documentation since it is not just a marker
trait anymore.

Fixes: 121d87b28e1d ("rust: io: separate generic I/O helpers from MMIO implementation")
Signed-off-by: Alexandre Courbot 
Link: https://patch.msgid.link/20260130-io-min-size-v1-1-65a546e3104d@nvidia.com
[ Fix typo in commit message. - Danilo ]
Signed-off-by: Danilo Krummrich

rust: pci: add config space read/write support

2026-01-23T20:23:16+00:00

Drivers might need to access PCI config space for querying capability
structures and access the registers inside the structures.

For Rust drivers need to access PCI config space, the Rust PCI abstraction
needs to support it in a way that upholds Rust's safety principles.

Introduce a `ConfigSpace` wrapper in Rust PCI abstraction to provide safe
accessors for PCI config space. The new type implements the `Io` trait and
`IoCapable` for u8, u16, and u32 to share offset validation and
bound-checking logic with other I/O backends.

The `ConfigSpace` type uses marker types (`Normal` and `Extended`) to
represent configuration space sizes at the type level.

Cc: Alexandre Courbot 
Cc: Danilo Krummrich 
Cc: Gary Guo 
Cc: Joel Fernandes 
Signed-off-by: Zhi Wang 
Reviewed-by: Gary Guo 
Link: https://lore.kernel.org/all/DFV4IJDQC2J6.1Q91JOAL6CJSG@kernel.org/ [1]
Link: https://patch.msgid.link/20260121202212.4438-5-zhiw@nvidia.com
[ Applied the diff from [1], considering subsequent comment; remove
  #[expect(unused)] from define_{read,write}!(). - Danilo ]
Signed-off-by: Danilo Krummrich

rust: io: separate generic I/O helpers from MMIO implementation

2026-01-23T20:20:11+00:00

The previous Io type combined both the generic I/O access helpers
and MMIO implementation details in a single struct. This coupling prevented
reusing the I/O helpers for other backends, such as PCI configuration
space.

Establish a clean separation between the I/O interface and concrete
backends by separating generic I/O helpers from MMIO implementation.

Introduce a new trait hierarchy to handle different access capabilities:

- IoCapable: A marker trait indicating that a backend supports I/O
  operations of a certain type (u8, u16, u32, or u64).

- Io trait: Defines fallible (try_read8, try_write8, etc.) and infallibile
  (read8, write8, etc.) I/O methods with runtime bounds checking and
  compile-time bounds checking.

- IoKnownSize trait: The marker trait for types support infallible I/O
  methods.

Move the MMIO-specific logic into a dedicated Mmio type that
implements the Io traits. Rename IoRaw to MmioRaw and update consumers to
use the new types.

Cc: Alexandre Courbot 
Cc: Alice Ryhl 
Cc: Bjorn Helgaas 
Cc: Gary Guo 
Cc: Danilo Krummrich 
Cc: John Hubbard 
Signed-off-by: Zhi Wang 
Reviewed-by: Alice Ryhl 
Reviewed-by: Alexandre Courbot 
Reviewed-by: Gary Guo 
Link: https://patch.msgid.link/20260121202212.4438-3-zhiw@nvidia.com
[ Add #[expect(unused)] to define_{read,write}!(). - Danilo ]
Signed-off-by: Danilo Krummrich

Merge tag 'v6.19-rc5' into driver-core-next

2026-01-12T12:33:24+00:00

We need the driver-core fixes in here as well to build on top of.

Signed-off-by: Danilo Krummrich

rust: pci: fix typos in Bar struct's comments

2026-01-06T19:58:43+00:00

Fix a typo in the doc-comment of the Bar structure: 'inststance ->
instance'.

Add also 'is' to the comment inside Bar's `new()` function (suggested
by Dirk):
// `pdev` is valid by the invariants of `Device`.

Fixes: bf9651f84b4e ("rust: pci: implement I/O mappable `pci::Bar`")
Suggested-by: Dirk Behme 
Signed-off-by: Marko Turk 
Reviewed-by: Dirk Behme 
Link: https://patch.msgid.link/20260105213726.73000-2-mt@markoturk.info
Signed-off-by: Danilo Krummrich