Hi Luis and Russ, I just noted I forgot to add you to this patch, sorry for that.
Please find the full series and previous discussions in [1]. - Danilo [1] https://lore.kernel.org/rust-for-linux/20240520172059.181256-1-d...@redhat.com/ On Mon, May 20, 2024 at 07:24:19PM +0200, Danilo Krummrich wrote: > Add an abstraction around the kernels firmware API to request firmware > images. The abstraction provides functions to access the firmware > buffer and / or copy it to a new buffer allocated with a given allocator > backend. > > The firmware is released once the abstraction is dropped. > > Signed-off-by: Danilo Krummrich <d...@redhat.com> > --- > rust/bindings/bindings_helper.h | 1 + > rust/kernel/firmware.rs | 74 +++++++++++++++++++++++++++++++++ > rust/kernel/lib.rs | 1 + > 3 files changed, 76 insertions(+) > create mode 100644 rust/kernel/firmware.rs > > diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h > index b245db8d5a87..e4ffc47da5ec 100644 > --- a/rust/bindings/bindings_helper.h > +++ b/rust/bindings/bindings_helper.h > @@ -14,6 +14,7 @@ > #include <kunit/test.h> > #include <linux/errname.h> > #include <linux/ethtool.h> > +#include <linux/firmware.h> > #include <linux/jiffies.h> > #include <linux/mdio.h> > #include <linux/pci.h> > diff --git a/rust/kernel/firmware.rs b/rust/kernel/firmware.rs > new file mode 100644 > index 000000000000..700504fb3c9c > --- /dev/null > +++ b/rust/kernel/firmware.rs > @@ -0,0 +1,74 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +//! Firmware abstraction > +//! > +//! C header: > [`include/linux/firmware.h`](../../../../include/linux/firmware.h") > + > +use crate::{bindings, device::Device, error::Error, error::Result, > str::CStr, types::Opaque}; > + > +/// Abstraction around a C firmware struct. > +/// > +/// This is a simple abstraction around the C firmware API. Just like with > the C API, firmware can > +/// be requested. Once requested the abstraction provides direct access to > the firmware buffer as > +/// `&[u8]`. Alternatively, the firmware can be copied to a new buffer using > `Firmware::copy`. The > +/// firmware is released once [`Firmware`] is dropped. > +/// > +/// # Examples > +/// > +/// ``` > +/// let fw = Firmware::request("path/to/firmware.bin", dev.as_ref())?; > +/// driver_load_firmware(fw.data()); > +/// ``` > +pub struct Firmware(Opaque<*const bindings::firmware>); > + > +impl Firmware { > + /// Send a firmware request and wait for it. See also > `bindings::request_firmware`. > + pub fn request(name: &CStr, dev: &Device) -> Result<Self> { > + let fw = Opaque::uninit(); > + > + let ret = unsafe { bindings::request_firmware(fw.get(), > name.as_char_ptr(), dev.as_raw()) }; > + if ret != 0 { > + return Err(Error::from_errno(ret)); > + } > + > + Ok(Firmware(fw)) > + } > + > + /// Send a request for an optional fw module. See also > `bindings::request_firmware_nowarn`. > + pub fn request_nowarn(name: &CStr, dev: &Device) -> Result<Self> { > + let fw = Opaque::uninit(); > + > + let ret = unsafe { > + bindings::firmware_request_nowarn(fw.get(), name.as_char_ptr(), > dev.as_raw()) > + }; > + if ret != 0 { > + return Err(Error::from_errno(ret)); > + } > + > + Ok(Firmware(fw)) > + } > + > + /// Returns the size of the requested firmware in bytes. > + pub fn size(&self) -> usize { > + unsafe { (*(*self.0.get())).size } > + } > + > + /// Returns the requested firmware as `&[u8]`. > + pub fn data(&self) -> &[u8] { > + unsafe { core::slice::from_raw_parts((*(*self.0.get())).data, > self.size()) } > + } > +} > + > +impl Drop for Firmware { > + fn drop(&mut self) { > + unsafe { bindings::release_firmware(*self.0.get()) }; > + } > +} > + > +// SAFETY: `Firmware` only holds a pointer to a C firmware struct, which is > safe to be used from any > +// thread. > +unsafe impl Send for Firmware {} > + > +// SAFETY: `Firmware` only holds a pointer to a C firmware struct, > references to which are safe to > +// be used from any thread. > +unsafe impl Sync for Firmware {} > diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs > index 6415968ee3b8..ed97d131661a 100644 > --- a/rust/kernel/lib.rs > +++ b/rust/kernel/lib.rs > @@ -35,6 +35,7 @@ > #[cfg(CONFIG_DRM = "y")] > pub mod drm; > pub mod error; > +pub mod firmware; > pub mod init; > pub mod ioctl; > #[cfg(CONFIG_KUNIT)] > -- > 2.45.1 >
