| Message ID | 20241212163357.35934-14-dakr@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Krzysztof Wilczyński |
| Headers | show |
| Series | Device / Driver PCI / Platform Rust abstractions | expand |
Hi Danilo, Danilo Krummrich <dakr@kernel.org> writes: > In order to not duplicate code in bus specific implementations (e.g. > platform), implement a generic `driver::Adapter` to represent the > connection of matched drivers and devices. > > Bus specific `Adapter` implementations can simply implement this trait > to inherit generic functionality, such as matching OF or ACPI device IDs > and ID table entries. > > Suggested-by: Rob Herring (Arm) <robh@kernel.org> > Signed-off-by: Danilo Krummrich <dakr@kernel.org> > --- I get some warnings when applying this patch: > RUSTC L rust/kernel.o > warning: unused import: `device_id` > --> /home/aeh/src/linux-rust/rnvme-v6.13-rc3/rust/kernel/driver.rs:10:13 > | > 10 | device, device_id, init::PinInit, of, str::CStr, try_pin_init, types::Opaque, ThisModule, > | ^^^^^^^^^ > | > = note: `#[warn(unused_imports)]` on by default > > warning: missing documentation for an associated function > --> /home/aeh/src/linux-rust/rnvme-v6.13-rc3/rust/kernel/driver.rs:158:5 > | > 158 | fn of_id_info(_dev: &device::Device) -> Option<&'static Self::IdInfo> { > | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > | > = note: requested on the command line with `-W missing-docs` > > warning: 2 warnings emitted Looks like the latter one is from patch 13. Best regards, Andreas Hindborg
On Thu, Dec 19, 2024 at 11:53:06AM +0100, Andreas Hindborg wrote: > > Hi Danilo, > > Danilo Krummrich <dakr@kernel.org> writes: > > > In order to not duplicate code in bus specific implementations (e.g. > > platform), implement a generic `driver::Adapter` to represent the > > connection of matched drivers and devices. > > > > Bus specific `Adapter` implementations can simply implement this trait > > to inherit generic functionality, such as matching OF or ACPI device IDs > > and ID table entries. > > > > Suggested-by: Rob Herring (Arm) <robh@kernel.org> > > Signed-off-by: Danilo Krummrich <dakr@kernel.org> > > --- > > I get some warnings when applying this patch: Ah, that's because your're probably having CONFIG_OF=n and some imports are only used within `of_id_info`. Gonna fix it for CONFIG_OF=n. > > > RUSTC L rust/kernel.o > > warning: unused import: `device_id` > > --> /home/aeh/src/linux-rust/rnvme-v6.13-rc3/rust/kernel/driver.rs:10:13 > > | > > 10 | device, device_id, init::PinInit, of, str::CStr, try_pin_init, types::Opaque, ThisModule, > > | ^^^^^^^^^ > > | > > = note: `#[warn(unused_imports)]` on by default > > > > warning: missing documentation for an associated function > > --> /home/aeh/src/linux-rust/rnvme-v6.13-rc3/rust/kernel/driver.rs:158:5 > > | > > 158 | fn of_id_info(_dev: &device::Device) -> Option<&'static Self::IdInfo> { > > | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > | > > = note: requested on the command line with `-W missing-docs` > > > > warning: 2 warnings emitted > > > Looks like the latter one is from patch 13. > > > Best regards, > Andreas Hindborg > >
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index 6d7a68e2ecb7..8fe70183a392 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -20,6 +20,7 @@ #include <linux/jump_label.h> #include <linux/mdio.h> #include <linux/miscdevice.h> +#include <linux/of_device.h> #include <linux/pci.h> #include <linux/phy.h> #include <linux/pid_namespace.h> diff --git a/rust/kernel/driver.rs b/rust/kernel/driver.rs index c1957ee7bb7e..63dbebbc0829 100644 --- a/rust/kernel/driver.rs +++ b/rust/kernel/driver.rs @@ -6,7 +6,9 @@ //! register using the [`Registration`] class. use crate::error::{Error, Result}; -use crate::{init::PinInit, str::CStr, try_pin_init, types::Opaque, ThisModule}; +use crate::{ + device, device_id, init::PinInit, of, str::CStr, try_pin_init, types::Opaque, ThisModule, +}; use core::pin::Pin; use macros::{pin_data, pinned_drop}; @@ -115,3 +117,58 @@ fn init( } } } + +/// The bus independent adapter to match a drivers and a devices. +/// +/// This trait should be implemented by the bus specific adapter, which represents the connection +/// of a device and a driver. +/// +/// It provides bus independent functions for device / driver interactions. +pub trait Adapter { + /// The type holding driver private data about each device id supported by the driver. + type IdInfo: 'static; + + /// The [`of::IdTable`] of the corresponding driver. + fn of_id_table() -> Option<of::IdTable<Self::IdInfo>>; + + /// Returns the driver's private data from the matching entry in the [`of::IdTable`], if any. + /// + /// If this returns `None`, it means there is no match with an entry in the [`of::IdTable`]. + #[cfg(CONFIG_OF)] + fn of_id_info(dev: &device::Device) -> Option<&'static Self::IdInfo> { + let table = Self::of_id_table()?; + + // SAFETY: + // - `table` has static lifetime, hence it's valid for read, + // - `dev` is guaranteed to be valid while it's alive, and so is `pdev.as_ref().as_raw()`. + let raw_id = unsafe { bindings::of_match_device(table.as_ptr(), dev.as_raw()) }; + + if raw_id.is_null() { + None + } else { + // SAFETY: `DeviceId` is a `#[repr(transparent)` wrapper of `struct of_device_id` and + // does not add additional invariants, so it's safe to transmute. + let id = unsafe { &*raw_id.cast::<of::DeviceId>() }; + + Some(table.info(<of::DeviceId as device_id::RawDeviceId>::index(id))) + } + } + + #[cfg(not(CONFIG_OF))] + fn of_id_info(_dev: &device::Device) -> Option<&'static Self::IdInfo> { + None + } + + /// Returns the driver's private data from the matching entry of any of the ID tables, if any. + /// + /// If this returns `None`, it means that there is no match in any of the ID tables directly + /// associated with a [`device::Device`]. + fn id_info(dev: &device::Device) -> Option<&'static Self::IdInfo> { + let id = Self::of_id_info(dev); + if id.is_some() { + return id; + } + + None + } +}
In order to not duplicate code in bus specific implementations (e.g. platform), implement a generic `driver::Adapter` to represent the connection of matched drivers and devices. Bus specific `Adapter` implementations can simply implement this trait to inherit generic functionality, such as matching OF or ACPI device IDs and ID table entries. Suggested-by: Rob Herring (Arm) <robh@kernel.org> Signed-off-by: Danilo Krummrich <dakr@kernel.org> --- rust/bindings/bindings_helper.h | 1 + rust/kernel/driver.rs | 59 ++++++++++++++++++++++++++++++++- 2 files changed, 59 insertions(+), 1 deletion(-)