[PATCH v14 0/3] rust: add basic serial device bus abstractions

Markus Probst posted 3 patches 1 week, 2 days ago
There is a newer version of this series
MAINTAINERS                        |   5 +-
drivers/tty/serdev/Kconfig         |   7 +
rust/bindings/bindings_helper.h    |   1 +
rust/helpers/helpers.c             |   1 +
rust/helpers/serdev.c              |  22 ++
rust/kernel/lib.rs                 |   2 +
rust/kernel/serdev.rs              | 599 +++++++++++++++++++++++++++++++++++++
samples/rust/Kconfig               |  11 +
samples/rust/Makefile              |   1 +
samples/rust/rust_driver_serdev.rs |  90 ++++++
10 files changed, 738 insertions(+), 1 deletion(-)
[PATCH v14 0/3] rust: add basic serial device bus abstractions
Posted by Markus Probst 1 week, 2 days ago
This patch series adds the serdev device bus rust abstraction into the
kernel.

This abstraction will be used by a driver,
which targets the MCU devices in Synology devices.

Kari Argillander also messaged me, stating that he wants to write a
watchdog driver with this abstraction (needing initial device data).

This series depends on [1].

[1] https://lore.kernel.org/rust-for-linux/20260530132736.3298549-1-dakr@kernel.org/

Signed-off-by: Markus Probst <markus.probst@posteo.de>
---
Changes in v14:
- fix issues reported by Sashiko:
  - fix missing Sync
  - fix write buffers allowed with data.len() > i32::MAX
  - fix sample driver possibly stalling on full tx buffer
- Link to v13: https://patch.msgid.link/20260712-rust_serdev-v13-0-2c4060bc8e30@posteo.de

Changes in v13:
- Added Acked-by trailer from Rob. Consider this a RESEND.
- Link to v12: https://patch.msgid.link/20260603-rust_serdev-v12-0-3400ffb88b12@posteo.de

Changes in v12:
- fix CoreInternal instead of BoundInternal
- Link to v11: https://patch.msgid.link/20260531-rust_serdev-v11-0-dee8e0d830f1@posteo.de

Changes in v11:
- redo changes from v9 with the following fixes:
  - fix memory leak on probe failure
  - fix possible access of dropped drvdata from receive_buf
- Link to v10: https://patch.msgid.link/20260530-rust_serdev-v10-0-65d1d5db876c@posteo.de

Changes in v10:
- revert everything from v9, except BoundInternal
- use mutex to ensure receive_buf won't be called on a dropped drvdata.
- Link to v9: https://patch.msgid.link/20260530-rust_serdev-v9-0-f8b5fccb49c3@posteo.de

Changes in v9:
- make use of BoundInternal
- use PrivateData wrapper and drop rust_private_data field
- use non-devm version of serdev_device_open
- Link to v8: https://patch.msgid.link/20260530-rust_serdev-v8-0-2a95f1da22a7@posteo.de

Changes in v8:
- adapted to driver-lifetime v5 patch series
- add MAINTAINERS file patch
- Link to v7: https://patch.msgid.link/20260429-rust_serdev-v7-0-0d89c791b5c8@posteo.de

Changes in v7:
- adapted to driver-lifetime patch series
- Link to v6: https://patch.msgid.link/20260427-rust_serdev-v6-0-173798d5e1a3@posteo.de

Changes in v6:
- rebased onto v7.1-rc1
- Link to v5: https://patch.msgid.link/20260420-rust_serdev-v5-0-57e8ba0519f3@posteo.de

Changes in v5:
- fix typo in documentation
- Link to v4: https://lore.kernel.org/r/20260411-rust_serdev-v4-0-845e960c6627@posteo.de

Changes in v4:
- fixed not selecting rust serdev abstraction in sample
- Link to v3: https://lore.kernel.org/r/20260313-rust_serdev-v3-0-c9a3af214f7f@posteo.de

Changes in v3:
- fix vertical import style
- add Kconfig entry for the rust abstraction
- fix documentation in include/linux/serdev.h
- rename private_data to rust_private_data
- fix `complete_all` <-> `wait_for_completion` typo
- move drvdata_borrow call after the completion
- Link to v2: https://lore.kernel.org/r/20260306-rust_serdev-v2-0-e9b23b42b255@posteo.de

Changes in v2:
- fix documentation in `serdev::Driver::write` and
  `serdev::Driver::write_all`
- remove use of `dev_info` in probe from the sample
- remove `properties_parse` from the sample
- add optional `baudrate` property to the sample
- remove 1. patch
- remove `TryFrom<&device::Device<Ctx>> for &serdev::Device<Ctx>`
  implementation
- fix import style
- add patch to return reference in `devres::register` to fix safety
  issue
- add patch to add private data to serdev_device, to fix
  `Device.drvdata()` from failing
- simplify abstraction by removing ability to receive the initial
  transmission. It may be added later in a separate patch series if
  needed.
- Link to v1: https://lore.kernel.org/r/20251220-rust_serdev-v1-0-e44645767621@posteo.de

---
Markus Probst (3):
      rust: add basic serial device bus abstractions
      samples: rust: add Rust serial device bus sample device driver
      MAINTAINERS: serdev: Add self for serdev

 MAINTAINERS                        |   5 +-
 drivers/tty/serdev/Kconfig         |   7 +
 rust/bindings/bindings_helper.h    |   1 +
 rust/helpers/helpers.c             |   1 +
 rust/helpers/serdev.c              |  22 ++
 rust/kernel/lib.rs                 |   2 +
 rust/kernel/serdev.rs              | 599 +++++++++++++++++++++++++++++++++++++
 samples/rust/Kconfig               |  11 +
 samples/rust/Makefile              |   1 +
 samples/rust/rust_driver_serdev.rs |  90 ++++++
 10 files changed, 738 insertions(+), 1 deletion(-)
---
base-commit: 1137d8b5df06137fb49513cc923b3b24d94cb809
change-id: 20251217-rust_serdev-ee5481e9085c
prerequisite-message-id: 20260530132736.3298549-1-dakr@kernel.org
prerequisite-patch-id: 310c6bee038ca3909a8e5e58ec12b74f7189b869
prerequisite-patch-id: 92812c3d42b29504838e6dc66c307ff5c035bb5e
Re: [PATCH v14 0/3] rust: add basic serial device bus abstractions
Posted by Greg Kroah-Hartman 1 week, 1 day ago
On Wed, Jul 15, 2026 at 09:00:14PM +0000, Markus Probst wrote:
> This patch series adds the serdev device bus rust abstraction into the
> kernel.
> 
> This abstraction will be used by a driver,
> which targets the MCU devices in Synology devices.
> 
> Kari Argillander also messaged me, stating that he wants to write a
> watchdog driver with this abstraction (needing initial device data).
> 
> This series depends on [1].
> 
> [1] https://lore.kernel.org/rust-for-linux/20260530132736.3298549-1-dakr@kernel.org/
> 
> Signed-off-by: Markus Probst <markus.probst@posteo.de>

Given there are no objections, I'll go queue this up now, thanks.

greg k-h
Re: [PATCH v14 0/3] rust: add basic serial device bus abstractions
Posted by Danilo Krummrich 1 week, 1 day ago
On 7/17/26 12:55 PM, Greg Kroah-Hartman wrote:
> On Wed, Jul 15, 2026 at 09:00:14PM +0000, Markus Probst wrote:
>> This patch series adds the serdev device bus rust abstraction into the
>> kernel.
>>
>> This abstraction will be used by a driver,
>> which targets the MCU devices in Synology devices.
>>
>> Kari Argillander also messaged me, stating that he wants to write a
>> watchdog driver with this abstraction (needing initial device data).
>>
>> This series depends on [1].
>>
>> [1] https://lore.kernel.org/rust-for-linux/20260530132736.3298549-1-dakr@kernel.org/
>>
>> Signed-off-by: Markus Probst <markus.probst@posteo.de>
> 
> Given there are no objections, I'll go queue this up now, thanks.
You'll need the patches from [1] as well.

Thanks,
Danilo
Re: [PATCH v14 0/3] rust: add basic serial device bus abstractions
Posted by Markus Probst 1 week, 1 day ago
On Fri, 2026-07-17 at 12:55 +0200, Greg Kroah-Hartman wrote:
> On Wed, Jul 15, 2026 at 09:00:14PM +0000, Markus Probst wrote:
> > This patch series adds the serdev device bus rust abstraction into the
> > kernel.
> > 
> > This abstraction will be used by a driver,
> > which targets the MCU devices in Synology devices.
> > 
> > Kari Argillander also messaged me, stating that he wants to write a
> > watchdog driver with this abstraction (needing initial device data).
> > 
> > This series depends on [1].
> > 
> > [1] https://lore.kernel.org/rust-for-linux/20260530132736.3298549-1-dakr@kernel.org/
> > 
> > Signed-off-by: Markus Probst <markus.probst@posteo.de>
> 
> Given there are no objections, I'll go queue this up now, thanks.
Thanks for merging, but I haven't seen the dependency

https://lore.kernel.org/rust-for-linux/20260530132736.3298549-1-dakr@kernel.org/

getting picked yet (its at least not in linux-next), so it might not
even compile. Not sure whats holding the patch back though.

Thanks
- Markus Probst


> 
> greg k-h
Re: [PATCH v14 0/3] rust: add basic serial device bus abstractions
Posted by Danilo Krummrich 1 week, 1 day ago
On 7/17/26 1:14 PM, Markus Probst wrote:
> On Fri, 2026-07-17 at 12:55 +0200, Greg Kroah-Hartman wrote:
>> On Wed, Jul 15, 2026 at 09:00:14PM +0000, Markus Probst wrote:
>>> This patch series adds the serdev device bus rust abstraction into the
>>> kernel.
>>>
>>> This abstraction will be used by a driver,
>>> which targets the MCU devices in Synology devices.
>>>
>>> Kari Argillander also messaged me, stating that he wants to write a
>>> watchdog driver with this abstraction (needing initial device data).
>>>
>>> This series depends on [1].
>>>
>>> [1] https://lore.kernel.org/rust-for-linux/20260530132736.3298549-1-dakr@kernel.org/
>>>
>>> Signed-off-by: Markus Probst <markus.probst@posteo.de>
>>
>> Given there are no objections, I'll go queue this up now, thanks.
> Thanks for merging, but I haven't seen the dependency
> 
> https://lore.kernel.org/rust-for-linux/20260530132736.3298549-1-dakr@kernel.org/
> 
> getting picked yet (its at least not in linux-next), so it might not
> even compile. Not sure whats holding the patch back though.
(Ah, saw this just after I replied to the other thread.)

Nothing is holding them back other than requiring a user (which is your work),
so I did not pick them up.

Also note that tty and driver-core are different trees, so picking it up in
driver-core would not have helped tty.

Thanks,
Danilo
Re: [PATCH v14 0/3] rust: add basic serial device bus abstractions
Posted by Greg Kroah-Hartman 1 week, 1 day ago
On Fri, Jul 17, 2026 at 01:22:40PM +0200, Danilo Krummrich wrote:
> On 7/17/26 1:14 PM, Markus Probst wrote:
> > On Fri, 2026-07-17 at 12:55 +0200, Greg Kroah-Hartman wrote:
> >> On Wed, Jul 15, 2026 at 09:00:14PM +0000, Markus Probst wrote:
> >>> This patch series adds the serdev device bus rust abstraction into the
> >>> kernel.
> >>>
> >>> This abstraction will be used by a driver,
> >>> which targets the MCU devices in Synology devices.
> >>>
> >>> Kari Argillander also messaged me, stating that he wants to write a
> >>> watchdog driver with this abstraction (needing initial device data).
> >>>
> >>> This series depends on [1].
> >>>
> >>> [1] https://lore.kernel.org/rust-for-linux/20260530132736.3298549-1-dakr@kernel.org/
> >>>
> >>> Signed-off-by: Markus Probst <markus.probst@posteo.de>
> >>
> >> Given there are no objections, I'll go queue this up now, thanks.
> > Thanks for merging, but I haven't seen the dependency
> > 
> > https://lore.kernel.org/rust-for-linux/20260530132736.3298549-1-dakr@kernel.org/
> > 
> > getting picked yet (its at least not in linux-next), so it might not
> > even compile. Not sure whats holding the patch back though.
> (Ah, saw this just after I replied to the other thread.)
> 
> Nothing is holding them back other than requiring a user (which is your work),
> so I did not pick them up.
> 
> Also note that tty and driver-core are different trees, so picking it up in
> driver-core would not have helped tty.

Should I drop this from the tty tree and take it through driver-core
instead?  If so, no problem for me, just let me know.

thanks,

greg k-h
Re: [PATCH v14 0/3] rust: add basic serial device bus abstractions
Posted by Gary Guo 1 week, 1 day ago
On Fri Jul 17, 2026 at 1:03 PM BST, Greg Kroah-Hartman wrote:
> On Fri, Jul 17, 2026 at 01:22:40PM +0200, Danilo Krummrich wrote:
>> On 7/17/26 1:14 PM, Markus Probst wrote:
>> > On Fri, 2026-07-17 at 12:55 +0200, Greg Kroah-Hartman wrote:
>> >> On Wed, Jul 15, 2026 at 09:00:14PM +0000, Markus Probst wrote:
>> >>> This patch series adds the serdev device bus rust abstraction into the
>> >>> kernel.
>> >>>
>> >>> This abstraction will be used by a driver,
>> >>> which targets the MCU devices in Synology devices.
>> >>>
>> >>> Kari Argillander also messaged me, stating that he wants to write a
>> >>> watchdog driver with this abstraction (needing initial device data).
>> >>>
>> >>> This series depends on [1].
>> >>>
>> >>> [1] https://lore.kernel.org/rust-for-linux/20260530132736.3298549-1-dakr@kernel.org/
>> >>>
>> >>> Signed-off-by: Markus Probst <markus.probst@posteo.de>
>> >>
>> >> Given there are no objections, I'll go queue this up now, thanks.
>> > Thanks for merging, but I haven't seen the dependency
>> > 
>> > https://lore.kernel.org/rust-for-linux/20260530132736.3298549-1-dakr@kernel.org/
>> > 
>> > getting picked yet (its at least not in linux-next), so it might not
>> > even compile. Not sure whats holding the patch back though.
>> (Ah, saw this just after I replied to the other thread.)
>> 
>> Nothing is holding them back other than requiring a user (which is your work),
>> so I did not pick them up.
>> 
>> Also note that tty and driver-core are different trees, so picking it up in
>> driver-core would not have helped tty.
>
> Should I drop this from the tty tree and take it through driver-core
> instead?  If so, no problem for me, just let me know.

FWIW this series will also conflict quite significantly with
https://lore.kernel.org/driver-core/20260629-id_info-v2-0-56fccbe9c5ef@garyguo.net/
which is routed via driver-core tree.

Best,
GAry
Re: [PATCH v14 0/3] rust: add basic serial device bus abstractions
Posted by Danilo Krummrich 1 week, 1 day ago
On Fri Jul 17, 2026 at 2:07 PM CEST, Gary Guo wrote:
> FWIW this series will also conflict quite significantly with
> https://lore.kernel.org/driver-core/20260629-id_info-v2-0-56fccbe9c5ef@garyguo.net/
> which is routed via driver-core tree.

Yeah, but I think it should be trivial (see below)? However, routing serdev
through driver-core does indeed avoid this.

Thanks,
Danilo

diff --git a/rust/kernel/serdev.rs b/rust/kernel/serdev.rs
index 0ffcef1849d2..a1161dd9f37f 100644
--- a/rust/kernel/serdev.rs
+++ b/rust/kernel/serdev.rs
@@ -174,7 +174,8 @@ extern "C" fn probe_callback(sdev: *mut bindings::serdev_device) -> kernel::ffi:
         //
         // INVARIANT: `sdev` is valid for the duration of `probe_callback()`.
         let sdev = unsafe { &*sdev.cast::<Device<device::CoreInternal<'_>>>() };
-        let info = <Self as driver::Adapter>::id_info(sdev.as_ref());
+        // SAFETY: `sdev` has been matched by the serial device bus via its device ID table.
+        let info = unsafe { <Self as driver::Adapter>::id_info(sdev.as_ref()) };

         from_result(|| {
             sdev.as_ref().set_drvdata(try_pin_init!(PrivateData::<T> {
@@ -334,7 +335,6 @@ macro_rules! module_serdev_device_driver {
 ///
 /// kernel::of_device_table!(
 ///     OF_TABLE,
-///     MODULE_OF_TABLE,
 ///     <MyDriver as serdev::Driver>::IdInfo,
 ///     [
 ///         (of::DeviceId::new(c"test,device"), ())
@@ -343,7 +343,6 @@ macro_rules! module_serdev_device_driver {
 ///
 /// kernel::acpi_device_table!(
 ///     ACPI_TABLE,
-///     MODULE_ACPI_TABLE,
 ///     <MyDriver as serdev::Driver>::IdInfo,
 ///     [
 ///         (acpi::DeviceId::new(c"LNUXBEEF"), ())
diff --git a/samples/rust/rust_driver_serdev.rs b/samples/rust/rust_driver_serdev.rs
index a12b1412db30..51b4898cd855 100644
--- a/samples/rust/rust_driver_serdev.rs
+++ b/samples/rust/rust_driver_serdev.rs
@@ -20,14 +20,12 @@ struct SampleDriver {

 kernel::of_device_table!(
     OF_TABLE,
-    MODULE_OF_TABLE,
     <SampleDriver as serdev::Driver>::IdInfo,
     [(of::DeviceId::new(c"test,rust_driver_serdev"), ())]
 );

 kernel::acpi_device_table!(
     ACPI_TABLE,
-    MODULE_ACPI_TABLE,
     <SampleDriver as serdev::Driver>::IdInfo,
     [(acpi::DeviceId::new(c"LNUXBEEF"), ())]
 );
Re: [PATCH v14 0/3] rust: add basic serial device bus abstractions
Posted by Markus Probst 1 week, 1 day ago
On Fri, 2026-07-17 at 14:20 +0200, Danilo Krummrich wrote:
> diff --git a/rust/kernel/serdev.rs b/rust/kernel/serdev.rs
> index 0ffcef1849d2..a1161dd9f37f 100644
> --- a/rust/kernel/serdev.rs
> +++ b/rust/kernel/serdev.rs
> @@ -174,7 +174,8 @@ extern "C" fn probe_callback(sdev: *mut bindings::serdev_device) -> kernel::ffi:
>          //
>          // INVARIANT: `sdev` is valid for the duration of `probe_callback()`.
>          let sdev = unsafe { &*sdev.cast::<Device<device::CoreInternal<'_>>>() };
> -        let info = <Self as driver::Adapter>::id_info(sdev.as_ref());
> +        // SAFETY: `sdev` has been matched by the serial device bus via its device ID table.
> +        let info = unsafe { <Self as driver::Adapter>::id_info(sdev.as_ref()) };
> 
>          from_result(|| {
>              sdev.as_ref().set_drvdata(try_pin_init!(PrivateData::<T> {
> @@ -334,7 +335,6 @@ macro_rules! module_serdev_device_driver {
>  ///
>  /// kernel::of_device_table!(
>  ///     OF_TABLE,
> -///     MODULE_OF_TABLE,
>  ///     <MyDriver as serdev::Driver>::IdInfo,
>  ///     [
>  ///         (of::DeviceId::new(c"test,device"), ())
> @@ -343,7 +343,6 @@ macro_rules! module_serdev_device_driver {
>  ///
>  /// kernel::acpi_device_table!(
>  ///     ACPI_TABLE,
> -///     MODULE_ACPI_TABLE,
>  ///     <MyDriver as serdev::Driver>::IdInfo,
>  ///     [
>  ///         (acpi::DeviceId::new(c"LNUXBEEF"), ())
> diff --git a/samples/rust/rust_driver_serdev.rs b/samples/rust/rust_driver_serdev.rs
> index a12b1412db30..51b4898cd855 100644
> --- a/samples/rust/rust_driver_serdev.rs
> +++ b/samples/rust/rust_driver_serdev.rs
> @@ -20,14 +20,12 @@ struct SampleDriver {
> 
>  kernel::of_device_table!(
>      OF_TABLE,
> -    MODULE_OF_TABLE,
>      <SampleDriver as serdev::Driver>::IdInfo,
>      [(of::DeviceId::new(c"test,rust_driver_serdev"), ())]
>  );
> 
>  kernel::acpi_device_table!(
>      ACPI_TABLE,
> -    MODULE_ACPI_TABLE,
>      <SampleDriver as serdev::Driver>::IdInfo,
>      [(acpi::DeviceId::new(c"LNUXBEEF"), ())]
>  );
Not sure if necessary for a conflict resolution, but

Reviewed-by: Markus Probst <markus.probst@posteo.de>

Thanks
- Markus Probst

Re: [PATCH v14 0/3] rust: add basic serial device bus abstractions
Posted by Danilo Krummrich 1 week, 1 day ago
On Fri Jul 17, 2026 at 2:03 PM CEST, Greg Kroah-Hartman wrote:
> Should I drop this from the tty tree and take it through driver-core
> instead?  If so, no problem for me, just let me know.

Either should work, you can also take [1] through the tty tree, I don't think
there will be any conflicts.

[1] https://lore.kernel.org/rust-for-linux/20260530132736.3298549-1-dakr@kernel.org/
Re: [PATCH v14 0/3] rust: add basic serial device bus abstractions
Posted by Greg Kroah-Hartman 1 week, 1 day ago
On Fri, Jul 17, 2026 at 02:07:48PM +0200, Danilo Krummrich wrote:
> On Fri Jul 17, 2026 at 2:03 PM CEST, Greg Kroah-Hartman wrote:
> > Should I drop this from the tty tree and take it through driver-core
> > instead?  If so, no problem for me, just let me know.
> 
> Either should work, you can also take [1] through the tty tree, I don't think
> there will be any conflicts.
> 
> [1] https://lore.kernel.org/rust-for-linux/20260530132736.3298549-1-dakr@kernel.org/
> 

Hm, that gets messy.  I'll just add these patches to the driver core
tree, along with the above linked ones, to keep things simple.

thanks,
greg k-h
Re: [PATCH v14 0/3] rust: add basic serial device bus abstractions
Posted by Danilo Krummrich 1 week, 1 day ago
On Fri Jul 17, 2026 at 3:12 PM CEST, Greg Kroah-Hartman wrote:
> Hm, that gets messy.  I'll just add these patches to the driver core
> tree, along with the above linked ones, to keep things simple.

Yeah, that's cleaner, thanks!