linux-toradex.git/rust/kernel/io, branch v6.19

rust: io: always inline functions using build_assert with arguments

2026-01-14T19:30:26+00:00

`build_assert` relies on the compiler to optimize out its error path.
Functions using it with its arguments must thus always be inlined,
otherwise the error path of `build_assert` might not be optimized out,
triggering a build error.

Cc: stable@vger.kernel.org
Fixes: ce30d94e6855 ("rust: add `io::{Io, IoRaw}` base types")
Reviewed-by: Daniel Almeida 
Signed-off-by: Alexandre Courbot 
Tested-by: Timur Tabi 
Link: https://patch.msgid.link/20251208-io-build-assert-v3-2-98aded02c1ea@nvidia.com
Signed-off-by: Danilo Krummrich

rust: io: add typedef for phys_addr_t

2025-11-13T09:17:24+00:00

The C typedef phys_addr_t is missing an analogue in Rust, meaning that
we end up using bindings::phys_addr_t or ResourceSize as a replacement
in various places throughout the kernel. Fix that by introducing a new
typedef on the Rust side. Place it next to the existing ResourceSize
typedef since they're quite related to each other.

Cc: stable@vger.kernel.org # for v6.18 [1]
Signed-off-by: Alice Ryhl 
Link: https://patch.msgid.link/20251112-resource-phys-typedefs-v2-4-538307384f82@google.com
Link: https://lore.kernel.org/all/20251112-resource-phys-typedefs-v2-0-538307384f82@google.com/ [1]
Signed-off-by: Danilo Krummrich

rust: io: move ResourceSize to top-level io module

2025-11-13T09:16:51+00:00

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 
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

rust: io: define ResourceSize as resource_size_t

2025-11-13T08:58:24+00:00

These typedefs are always equivalent so this should not change anything,
but the code makes a lot more sense like this.

Cc: stable@vger.kernel.org
Signed-off-by: Alice Ryhl 
Fixes: 493fc33ec252 ("rust: io: add resource abstraction")
Link: https://patch.msgid.link/20251112-resource-phys-typedefs-v2-1-538307384f82@google.com
Signed-off-by: Danilo Krummrich

rust: io: cleanup imports and use "kernel vertical" style

2025-11-11T08:43:39+00:00

Commit 46f045db5a94 ("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 
Link: https://patch.msgid.link/20251104133301.59402-1-dakr@kernel.org
[ Use prelude::* in io/poll.rs. - Danilo ]
Signed-off-by: Danilo Krummrich

rust: Add read_poll_timeout_atomic function

2025-11-04T13:06:47+00:00

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 
Signed-off-by: FUJITA Tomonori 
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

rust: simplify read_poll_timeout's example code

2025-10-26T16:56:14+00:00

- Drop unnecessary Result's '<()>'
- Use '?' instead of match

Signed-off-by: FUJITA Tomonori 
Signed-off-by: Danilo Krummrich

rust: driver: let probe() return impl PinInit

2025-10-21T16:40:48+00:00

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>>
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 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 instead
of Result>>.

Reviewed-by: Alice Ryhl 
Acked-by: Viresh Kumar 
Reviewed-by: Alexandre Courbot 
Acked-by: Greg Kroah-Hartman 
Signed-off-by: Danilo Krummrich

rust: Add read_poll_timeout function

2025-08-21T19:09:48+00:00

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 
Reviewed-by: Fiona Behrens 
Reviewed-by: Alexandre Courbot 
Tested-by: Alexandre Courbot 
Reviewed-by: Daniel Almeida 
Tested-by: Daniel Almeida 
Reviewed-by: Alice Ryhl 
Signed-off-by: FUJITA Tomonori 
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

rust: io: fix broken intra-doc links to `platform::Device`

2025-07-22T09:08:59+00:00

`platform` is not accessible from here.

Thus fix the intra-doc links by qualifying the paths a bit more.

Fixes: 1d0d4b28513b ("rust: io: mem: add a generic iomem abstraction")
Signed-off-by: Miguel Ojeda 
Link: https://lore.kernel.org/r/20250722085500.1360401-2-ojeda@kernel.org
Signed-off-by: Danilo Krummrich