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 <dakr at 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
On Mon, 20 May 2024 19:24:19 +0200 Danilo Krummrich <dakr at redhat.com> 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. >Was playing with firmware extractions based on this patch. Unfortunately I ended up with a lot of pointer operations, unsafe statements. As we know many vendors have a C headers for the definitions of the firwmare content, the driver extract the data by applying a struct pointer on it. But in rust, I feel it would nice that we can also have a common firmware extractor for drivers, that can wrap the pointer operations, take a list of the firmware struct members that converted from C headers as the input, offer the driver some common ABI methods to query them. Maybe that would ease the pain a lot. Thanks, Zhi.> The firmware is released once the abstraction is dropped. > > Signed-off-by: Danilo Krummrich <dakr at 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)]
On Tue, May 21, 2024 at 08:32:31AM +0300, Zhi Wang wrote:> On Mon, 20 May 2024 19:24:19 +0200 > Danilo Krummrich <dakr at redhat.com> 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. > > > > Was playing with firmware extractions based on this patch. > Unfortunately I ended up with a lot of pointer operations, unsafe > statements. > > As we know many vendors have a C headers for the definitions of the > firwmare content, the driver extract the data by applying a struct > pointer on it. > > But in rust, I feel it would nice that we can also have a common > firmware extractor for drivers, that can wrap the pointer operations, > take a list of the firmware struct members that converted from C headers > as the input, offer the driver some common ABI methods to query them. > Maybe that would ease the pain a lot.So, you mean some abstraction that takes a list of types, offsets in the firmware and a reference to the firmware itself and provides references to the corresponding objects? I agree it might be helpful to have some common infrastructure for this, but the operations on it would still be unsafe, since ultimately it involves dereferencing pointers.> > Thanks, > Zhi. > > > The firmware is released once the abstraction is dropped. > > > > Signed-off-by: Danilo Krummrich <dakr at 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)] >
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-dakr at 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 <dakr at 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 >