[PATCH v3 11/27] rust: platform: make Driver trait lifetime-parameterized

[Danilo Krummrich <dakr@kernel.org>]

Add a 'bound lifetime to the associated Data, changing type Data to type
Data<'bound>.

This allows the driver's bus device private data to capture the device /
driver bound lifetime; device resources can be stored directly by
reference rather than requiring Devres.

The probe() and unbind() callbacks thus gain a 'bound lifetime parameter
on the methods themselves; avoiding a global lifetime on the trait impl.

Existing drivers set type Data<'bound> = Self, preserving the current
behavior.

Acked-by: Uwe Kleine-König <ukleinek@kernel.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 drivers/cpufreq/rcpufreq_dt.rs       | 10 +++++-----
 drivers/gpu/drm/tyr/driver.rs        | 10 +++++-----
 drivers/pwm/pwm_th1520.rs            | 10 +++++-----
 rust/kernel/cpufreq.rs               | 10 +++++-----
 rust/kernel/io/mem.rs                | 20 ++++++++++----------
 rust/kernel/platform.rs              | 26 +++++++++++++-------------
 samples/rust/rust_debugfs.rs         | 10 +++++-----
 samples/rust/rust_driver_platform.rs | 10 +++++-----
 samples/rust/rust_i2c_client.rs      | 15 +++++++++------
 samples/rust/rust_soc.rs             | 10 +++++-----
 10 files changed, 67 insertions(+), 64 deletions(-)

diff --git a/drivers/cpufreq/rcpufreq_dt.rs b/drivers/cpufreq/rcpufreq_dt.rs
index b7eeb2730eb0..bd64586ceb06 100644
--- a/drivers/cpufreq/rcpufreq_dt.rs
+++ b/drivers/cpufreq/rcpufreq_dt.rs
@@ -201,13 +201,13 @@ fn register_em(policy: &mut cpufreq::Policy) {
 
 impl platform::Driver for CPUFreqDTDriver {
     type IdInfo = ();
-    type Data = Self;
+    type Data<'bound> = Self;
     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
 
-    fn probe(
-        pdev: &platform::Device<Core>,
-        _id_info: Option<&Self::IdInfo>,
-    ) -> impl PinInit<Self, Error> {
+    fn probe<'bound>(
+        pdev: &'bound platform::Device<Core>,
+        _id_info: Option<&'bound Self::IdInfo>,
+    ) -> impl PinInit<Self, Error> + 'bound {
         cpufreq::Registration::<CPUFreqDTDriver>::new_foreign_owned(pdev.as_ref())?;
         Ok(Self {})
     }
diff --git a/drivers/gpu/drm/tyr/driver.rs b/drivers/gpu/drm/tyr/driver.rs
index c81bf217743d..3ac3b9979264 100644
--- a/drivers/gpu/drm/tyr/driver.rs
+++ b/drivers/gpu/drm/tyr/driver.rs
@@ -91,13 +91,13 @@ fn issue_soft_reset(dev: &Device<Bound>, iomem: &Devres<IoMem>) -> Result {
 
 impl platform::Driver for TyrPlatformDriverData {
     type IdInfo = ();
-    type Data = Self;
+    type Data<'bound> = Self;
     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
 
-    fn probe(
-        pdev: &platform::Device<Core>,
-        _info: Option<&Self::IdInfo>,
-    ) -> impl PinInit<Self, Error> {
+    fn probe<'bound>(
+        pdev: &'bound platform::Device<Core>,
+        _info: Option<&'bound Self::IdInfo>,
+    ) -> impl PinInit<Self, Error> + 'bound {
         let core_clk = Clk::get(pdev.as_ref(), Some(c"core"))?;
         let stacks_clk = OptionalClk::get(pdev.as_ref(), Some(c"stacks"))?;
         let coregroup_clk = OptionalClk::get(pdev.as_ref(), Some(c"coregroup"))?;
diff --git a/drivers/pwm/pwm_th1520.rs b/drivers/pwm/pwm_th1520.rs
index 07795910a0b5..1abf580653fa 100644
--- a/drivers/pwm/pwm_th1520.rs
+++ b/drivers/pwm/pwm_th1520.rs
@@ -316,13 +316,13 @@ fn drop(self: Pin<&mut Self>) {
 
 impl platform::Driver for Th1520PwmPlatformDriver {
     type IdInfo = ();
-    type Data = Self;
+    type Data<'bound> = Self;
     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
 
-    fn probe(
-        pdev: &platform::Device<Core>,
-        _id_info: Option<&Self::IdInfo>,
-    ) -> impl PinInit<Self, Error> {
+    fn probe<'bound>(
+        pdev: &'bound platform::Device<Core>,
+        _id_info: Option<&'bound Self::IdInfo>,
+    ) -> impl PinInit<Self, Error> + 'bound {
         let dev = pdev.as_ref();
         let request = pdev.io_request_by_index(0).ok_or(ENODEV)?;
 
diff --git a/rust/kernel/cpufreq.rs b/rust/kernel/cpufreq.rs
index 50dd2a2c3e81..208c055a39f3 100644
--- a/rust/kernel/cpufreq.rs
+++ b/rust/kernel/cpufreq.rs
@@ -888,13 +888,13 @@ fn register_em(_policy: &mut Policy) {
 ///
 /// impl platform::Driver for SampleDriver {
 ///     type IdInfo = ();
-///     type Data = Self;
+///     type Data<'bound> = Self;
 ///     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = None;
 ///
-///     fn probe(
-///         pdev: &platform::Device<Core>,
-///         _id_info: Option<&Self::IdInfo>,
-///     ) -> impl PinInit<Self, Error> {
+///     fn probe<'bound>(
+///         pdev: &'bound platform::Device<Core>,
+///         _id_info: Option<&'bound Self::IdInfo>,
+///     ) -> impl PinInit<Self, Error> + 'bound {
 ///         cpufreq::Registration::<SampleDriver>::new_foreign_owned(pdev.as_ref())?;
 ///         Ok(Self {})
 ///     }
diff --git a/rust/kernel/io/mem.rs b/rust/kernel/io/mem.rs
index e136b676d372..1b34f7ebd929 100644
--- a/rust/kernel/io/mem.rs
+++ b/rust/kernel/io/mem.rs
@@ -62,12 +62,12 @@ pub(crate) unsafe fn new(device: &'a Device<Bound>, resource: &'a Resource) -> S
     ///
     /// impl platform::Driver for SampleDriver {
     ///    # type IdInfo = ();
-    ///    # type Data = Self;
+    ///    # type Data<'bound> = Self;
     ///
-    ///    fn probe(
-    ///       pdev: &platform::Device<Core>,
-    ///       info: Option<&Self::IdInfo>,
-    ///    ) -> impl PinInit<Self, Error> {
+    ///    fn probe<'bound>(
+    ///       pdev: &'bound platform::Device<Core>,
+    ///       info: Option<&'bound Self::IdInfo>,
+    ///    ) -> impl PinInit<Self, Error> + 'bound {
     ///       let offset = 0; // Some offset.
     ///
     ///       // If the size is known at compile time, use [`Self::iomap_sized`].
@@ -127,12 +127,12 @@ pub fn iomap_exclusive_sized<const SIZE: usize>(
     ///
     /// impl platform::Driver for SampleDriver {
     ///    # type IdInfo = ();
-    ///    # type Data = Self;
+    ///    # type Data<'bound> = Self;
     ///
-    ///    fn probe(
-    ///       pdev: &platform::Device<Core>,
-    ///       info: Option<&Self::IdInfo>,
-    ///    ) -> impl PinInit<Self, Error> {
+    ///    fn probe<'bound>(
+    ///       pdev: &'bound platform::Device<Core>,
+    ///       info: Option<&'bound Self::IdInfo>,
+    ///    ) -> impl PinInit<Self, Error> + 'bound {
     ///       let offset = 0; // Some offset.
     ///
     ///       // Unlike [`Self::iomap_sized`], here the size of the memory region
diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index a72ad5366931..6e4437866c30 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -50,7 +50,7 @@
 // - `DEVICE_DRIVER_OFFSET` is the correct byte offset to the embedded `struct device_driver`.
 unsafe impl<T: Driver> driver::DriverLayout for Adapter<T> {
     type DriverType = bindings::platform_driver;
-    type DriverData<'bound> = T::Data;
+    type DriverData<'bound> = T::Data<'bound>;
     const DEVICE_DRIVER_OFFSET: usize = core::mem::offset_of!(Self::DriverType, driver);
 }
 
@@ -118,7 +118,7 @@ extern "C" fn remove_callback(pdev: *mut bindings::platform_device) {
         // SAFETY: `remove_callback` is only ever called after a successful call to
         // `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called
         // and stored a `Pin<KBox<T::Data>>`.
-        let data = unsafe { pdev.as_ref().drvdata_borrow::<T::Data>() };
+        let data = unsafe { pdev.as_ref().drvdata_borrow::<T::Data<'_>>() };
 
         T::unbind(pdev, data);
     }
@@ -192,14 +192,14 @@ macro_rules! module_platform_driver {
 ///
 /// impl platform::Driver for MyDriver {
 ///     type IdInfo = ();
-///     type Data = Self;
+///     type Data<'bound> = Self;
 ///     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
 ///     const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
 ///
-///     fn probe(
-///         _pdev: &platform::Device<Core>,
-///         _id_info: Option<&Self::IdInfo>,
-///     ) -> impl PinInit<Self, Error> {
+///     fn probe<'bound>(
+///         _pdev: &'bound platform::Device<Core>,
+///         _id_info: Option<&'bound Self::IdInfo>,
+///     ) -> impl PinInit<Self::Data<'bound>, Error> + 'bound {
 ///         Err(ENODEV)
 ///     }
 /// }
@@ -214,7 +214,7 @@ pub trait Driver: Send {
     type IdInfo: 'static;
 
     /// The type of the driver's bus device private data.
-    type Data;
+    type Data<'bound>: 'bound;
 
     /// The table of OF device ids supported by the driver.
     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = None;
@@ -226,10 +226,10 @@ pub trait Driver: Send {
     ///
     /// Called when a new platform device is added or discovered.
     /// Implementers should attempt to initialize the device here.
-    fn probe(
-        dev: &Device<device::Core>,
-        id_info: Option<&Self::IdInfo>,
-    ) -> impl PinInit<Self::Data, Error>;
+    fn probe<'bound>(
+        dev: &'bound Device<device::Core>,
+        id_info: Option<&'bound Self::IdInfo>,
+    ) -> impl PinInit<Self::Data<'bound>, Error> + 'bound;
 
     /// Platform driver unbind.
     ///
@@ -241,7 +241,7 @@ fn probe(
     /// operations to gracefully tear down the device.
     ///
     /// Otherwise, release operations for driver resources should be performed in `Drop`.
-    fn unbind(dev: &Device<device::Core>, this: Pin<&Self::Data>) {
+    fn unbind<'bound>(dev: &'bound Device<device::Core>, this: Pin<&'bound Self::Data<'bound>>) {
         let _ = (dev, this);
     }
 }
diff --git a/samples/rust/rust_debugfs.rs b/samples/rust/rust_debugfs.rs
index 478c4f693deb..5f02f2ad88b6 100644
--- a/samples/rust/rust_debugfs.rs
+++ b/samples/rust/rust_debugfs.rs
@@ -117,14 +117,14 @@ fn from_str(s: &str) -> Result<Self> {
 
 impl platform::Driver for RustDebugFs {
     type IdInfo = ();
-    type Data = Self;
+    type Data<'bound> = Self;
     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = None;
     const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
 
-    fn probe(
-        pdev: &platform::Device<Core>,
-        _info: Option<&Self::IdInfo>,
-    ) -> impl PinInit<Self, Error> {
+    fn probe<'bound>(
+        pdev: &'bound platform::Device<Core>,
+        _info: Option<&'bound Self::IdInfo>,
+    ) -> impl PinInit<Self, Error> + 'bound {
         RustDebugFs::new(pdev).pin_chain(|this| {
             this.counter.store(91, Relaxed);
             {
diff --git a/samples/rust/rust_driver_platform.rs b/samples/rust/rust_driver_platform.rs
index 6505902f8200..0760d60b7737 100644
--- a/samples/rust/rust_driver_platform.rs
+++ b/samples/rust/rust_driver_platform.rs
@@ -101,14 +101,14 @@ struct SampleDriver {
 
 impl platform::Driver for SampleDriver {
     type IdInfo = Info;
-    type Data = Self;
+    type Data<'bound> = Self;
     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
     const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
 
-    fn probe(
-        pdev: &platform::Device<Core>,
-        info: Option<&Self::IdInfo>,
-    ) -> impl PinInit<Self, Error> {
+    fn probe<'bound>(
+        pdev: &'bound platform::Device<Core>,
+        info: Option<&'bound Self::IdInfo>,
+    ) -> impl PinInit<Self, Error> + 'bound {
         let dev = pdev.as_ref();
 
         dev_dbg!(dev, "Probe Rust Platform driver sample.\n");
diff --git a/samples/rust/rust_i2c_client.rs b/samples/rust/rust_i2c_client.rs
index 5956b647294d..3ac4008a2eaa 100644
--- a/samples/rust/rust_i2c_client.rs
+++ b/samples/rust/rust_i2c_client.rs
@@ -106,14 +106,14 @@ struct SampleDriver {
 
 impl platform::Driver for SampleDriver {
     type IdInfo = ();
-    type Data = Self;
+    type Data<'bound> = Self;
     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
     const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
 
-    fn probe(
-        pdev: &platform::Device<device::Core>,
-        _info: Option<&Self::IdInfo>,
-    ) -> impl PinInit<Self, Error> {
+    fn probe<'bound>(
+        pdev: &'bound platform::Device<device::Core>,
+        _info: Option<&'bound Self::IdInfo>,
+    ) -> impl PinInit<Self, Error> + 'bound {
         dev_info!(
             pdev.as_ref(),
             "Probe Rust I2C Client registration sample.\n"
@@ -130,7 +130,10 @@ fn probe(
         })
     }
 
-    fn unbind(pdev: &platform::Device<device::Core>, _this: Pin<&Self>) {
+    fn unbind<'bound>(
+        pdev: &'bound platform::Device<device::Core>,
+        _this: Pin<&'bound Self::Data<'bound>>,
+    ) {
         dev_info!(
             pdev.as_ref(),
             "Unbind Rust I2C Client registration sample.\n"
diff --git a/samples/rust/rust_soc.rs b/samples/rust/rust_soc.rs
index a5e72582f4a2..2dfcb2131e25 100644
--- a/samples/rust/rust_soc.rs
+++ b/samples/rust/rust_soc.rs
@@ -37,14 +37,14 @@ struct SampleSocDriver {
 
 impl platform::Driver for SampleSocDriver {
     type IdInfo = ();
-    type Data = Self;
+    type Data<'bound> = Self;
     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
     const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
 
-    fn probe(
-        pdev: &platform::Device<Core>,
-        _info: Option<&Self::IdInfo>,
-    ) -> impl PinInit<Self, Error> {
+    fn probe<'bound>(
+        pdev: &'bound platform::Device<Core>,
+        _info: Option<&'bound Self::IdInfo>,
+    ) -> impl PinInit<Self, Error> + 'bound {
         dev_dbg!(pdev, "Probe Rust SoC driver sample.\n");
 
         let pdev = pdev.into();
-- 
2.54.0