Resource sizes are a general concept for dealing with physical
addresses, and not specific to the Resource type, which is just one way
to access physical addresses. Thus, move the typedef to the io module.
Still keep a re-export under resource. This avoids this commit from
being a flag-day, but I also think it's a useful re-export in general so
that you can import
use kernel::io::resource::{Resource, ResourceSize};
instead of having to write
use kernel::io::{
resource::Resource,
ResourceSize,
};
in the specific cases where you need ResourceSize because you are using
the Resource type. Therefore I think it makes sense to keep this
re-export indefinitely and it is *not* intended as a temporary re-export
for migration purposes.
Cc: stable@vger.kernel.org # for v6.18 [1]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251112-resource-phys-typedefs-v2-2-538307384f82@google.com
Link: https://lore.kernel.org/all/20251112-resource-phys-typedefs-v2-0-538307384f82@google.com/ [1]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Commit 46f045db5a ("rust: Add read_poll_timeout_atomic function")
initiated the first import change in the I/O module using the agreed
"kernel vertical" import style [1].
For consistency throughout the module, adjust all other imports
accordingly.
While at it, drop unnecessary imports covered by prelude::*.
Link: https://docs.kernel.org/rust/coding-guidelines.html#imports [1]
Reviewed-by: Zhi Wang <zhiw@nvidia.com>
Link: https://patch.msgid.link/20251104133301.59402-1-dakr@kernel.org
[ Use prelude::* in io/poll.rs. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add read_poll_timeout_atomic function which polls periodically until a
condition is met, an error occurs, or the attempt limit is reached.
The C's read_poll_timeout_atomic() is used for the similar purpose.
In atomic context the timekeeping infrastructure is unavailable, so
reliable time-based timeouts cannot be implemented. So instead, the
helper accepts a maximum number of attempts and busy-waits (udelay +
cpu_relax) between tries.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://patch.msgid.link/20251103112958.2961517-3-fujita.tomonori@gmail.com
[ Adjust imports to use "kernel vertical" style. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
- Drop unnecessary Result's '<()>'
- Use '?' instead of match
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
The driver model defines the lifetime of the private data stored in (and
owned by) a bus device to be valid from when the driver is bound to a
device (i.e. from successful probe()) until the driver is unbound from
the device.
This is already taken care of by the Rust implementation of the driver
model. However, we still ask drivers to return a Result<Pin<KBox<Self>>>
from probe().
Unlike in C, where we do not have the concept of initializers, but
rather deal with uninitialized memory, drivers can just return an
impl PinInit<Self, Error> instead.
This contributes to more clarity to the fact that a driver returns it's
device private data in probe() and the Rust driver model owns the data,
manages the lifetime and - considering the lifetime - provides (safe)
accessors for the driver.
Hence, let probe() functions return an impl PinInit<Self, Error> instead
of Result<Pin<KBox<Self>>>.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Add read_poll_timeout function which polls periodically until a
condition is met, an error occurs, or the timeout is reached.
The C's read_poll_timeout (include/linux/iopoll.h) is a complicated
macro and a simple wrapper for Rust doesn't work. So this implements
the same functionality in Rust.
The C version uses usleep_range() while the Rust version uses
fsleep(), which uses the best sleep method so it works with spans that
usleep_range() doesn't work nicely with.
The sleep_before_read argument isn't supported since there is no user
for now. It's rarely used in the C version.
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Tested-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://lore.kernel.org/r/20250821002055.3654160-3-fujita.tomonori@gmail.com
[ Fix a minor typo and add missing backticks. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
`platform` is not accessible from here.
Thus fix the intra-doc links by qualifying the paths a bit more.
Fixes: 1d0d4b2851 ("rust: io: mem: add a generic iomem abstraction")
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/r/20250722085500.1360401-2-ojeda@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
There is no `mod flags` in this case, unlike others. Instead, they are
associated constants for the `Flags` type.
Thus reword the sentence to fix the broken intra-doc link, providing
an example of constant and linking to it to clarify which ones we are
referring to.
Fixes: 493fc33ec2 ("rust: io: add resource abstraction")
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/r/20250722085500.1360401-1-ojeda@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
When introduced, the IoRequest doc-tests did depend on infrastructure
added in subsequent patches, hence they temporarily had to be disabled.
Now that we have the corresponding platform device infrastructure,
enable them.
Link: https://lore.kernel.org/r/DBG39YMN2TX6.1VR4PEQSI8PSG@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
The previous patches have added the abstractions for Resources and the
ability to map them and therefore read and write the underlying memory .
The only thing missing to make this accessible for platform devices is
to provide accessors that return instances of IoRequest<'a>. These
ensure that the resource are valid only for the lifetime of the platform
device, and that the platform device is in the Bound state.
Therefore, add these accessors. Also make it possible to retrieve
resources from platform devices in Rust using either a name or an index.
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
Link: https://lore.kernel.org/r/20250717-topics-tyr-platform_iomem-v15-3-beca780b77e3@collabora.com
[ Remove #[expect(dead_code)] from IoRequest::new() and move SAFETY
comments right on top of unsafe blocks to avoid clippy warnings for
some (older) clippy versions. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
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>
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>
Alice Ryhl