[RFC PATCH 7/8] rust: add firmware abstractions

[FUJITA Tomonori]

Hi,

On Wed, 29 May 2024 21:57:03 +0200
Greg KH <gregkh at linuxfoundation.org> wrote:

>> For a Rust PHY driver, you know that you have a valid pointer to C's
>> device object of C's PHY device during the probe callback. The driver
>> creates a Rust device object to wrap the C pointer to the C's device
>> object and passes it to the firmware abstractions. The firmware
>> abstractions gets the C's pointer from the Rust object and calls C's
>> function to load firmware, returns the result.
>> 
>> You have concerns about the simple code like the following?
>> 
>> 
>> diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
>> new file mode 100644
>> index 000000000000..6144437984a9
>> --- /dev/null
>> +++ b/rust/kernel/device.rs
>> @@ -0,0 +1,30 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +
>> +//! Generic devices that are part of the kernel's driver model.
>> +//!
>> +//! C header: [`include/linux/device.h`](srctree/include/linux/device.h)
>> +
>> +use crate::types::Opaque;
>> +
>> +#[repr(transparent)]
>> +pub struct Device(Opaque<bindings::device>);
>> +
>> +impl Device {
>> +    /// Creates a new [`Device`] instance from a raw pointer.
>> +    ///
>> +    /// # Safety
>> +    ///
>> +    /// For the duration of 'a, the pointer must point at a valid `device`.
> 
> If the following rust code does what this comment says, then sure, I'm
> ok with it for now if it helps you all out with stuff like the firmware
> interface for the phy rust code.

Great, thanks a lot!

Danilo and Wedson, are there any concerns about pushing this patch [1]
for the firmware abstractions?

I you prefer to be the author of the patch, please let me know. Who
the author is doesn't matter to me. Otherwise, I'll add
Co-developed-by tag.

[1] https://lore.kernel.org/rust-for-linux/20240529.092821.1593412345609718860.fujita.tomonori@gmail.com/