| Message ID | 20230613045326.3938283-3-fujita.tomonori@gmail.com (mailing list archive) |
|---|---|
| State | Deferred |
| Headers | show |
| Series | Rust abstractions for network device drivers | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch, async |
You have a typo in the commit message: net_devicve_ops should be net_device_ops On Tue, Jun 13, 2023 at 8:20 AM FUJITA Tomonori <fujita.tomonori@gmail.com> wrote: > > This improves abstractions for network device drivers to implement > struct ethtool_ops, the majority of ethernet device drivers need to > do. > > struct ethtool_ops also needs to access to device private data like > struct net_devicve_ops. > > Currently, only get_ts_info operation is supported. The following > patch adds the Rust version of the dummy network driver, which uses > the operation. > > Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com> > --- > rust/bindings/bindings_helper.h | 1 + > rust/kernel/net/dev.rs | 108 ++++++++++++++++++++++++++++++++ > 2 files changed, 109 insertions(+) > > diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h > index 468bf606f174..6446ff764980 100644 > --- a/rust/bindings/bindings_helper.h > +++ b/rust/bindings/bindings_helper.h > @@ -8,6 +8,7 @@ > > #include <linux/errname.h> > #include <linux/etherdevice.h> > +#include <linux/ethtool.h> > #include <linux/netdevice.h> > #include <linux/slab.h> > #include <linux/refcount.h> > diff --git a/rust/kernel/net/dev.rs b/rust/kernel/net/dev.rs > index d072c81f99ce..d6012b2eea33 100644 > --- a/rust/kernel/net/dev.rs > +++ b/rust/kernel/net/dev.rs > @@ -141,6 +141,18 @@ pub fn register(&mut self) -> Result { > } > } > > + /// Sets `ethtool_ops` of `net_device`. > + pub fn set_ether_operations<U>(&mut self) -> Result > + where > + U: EtherOperations<D>, > + { > + if self.is_registered { > + return Err(code::EINVAL); > + } > + EtherOperationsAdapter::<U, D>::new().set_ether_ops(&mut self.dev); > + Ok(()) > + } > + > const DEVICE_OPS: bindings::net_device_ops = bindings::net_device_ops { > ndo_init: if <T>::HAS_INIT { > Some(Self::init_callback) > @@ -342,3 +354,99 @@ fn drop(&mut self) { > } > } > } > + > +/// Builds the kernel's `struct ethtool_ops`. > +struct EtherOperationsAdapter<D, T> { > + _p: PhantomData<(D, T)>, > +} > + > +impl<D, T> EtherOperationsAdapter<T, D> > +where > + D: DriverData, > + T: EtherOperations<D>, > +{ > + /// Creates a new instance. > + fn new() -> Self { > + EtherOperationsAdapter { _p: PhantomData } > + } > + > + unsafe extern "C" fn get_ts_info_callback( > + netdev: *mut bindings::net_device, > + info: *mut bindings::ethtool_ts_info, > + ) -> core::ffi::c_int { > + from_result(|| { > + // SAFETY: The C API guarantees that `netdev` is valid while this function is running. > + let mut dev = unsafe { Device::from_ptr(netdev) }; > + // SAFETY: The returned pointer was initialized by `D::Data::into_foreign` when > + // `Registration` object was created. > + // `D::Data::from_foreign` is only called by the object was released. > + // So we know `data` is valid while this function is running. > + let data = unsafe { D::Data::borrow(dev.priv_data_ptr()) }; > + // SAFETY: The C API guarantees that `info` is valid while this function is running. > + let mut info = unsafe { EthtoolTsInfo::from_ptr(info) }; > + T::get_ts_info(&mut dev, data, &mut info)?; > + Ok(0) > + }) > + } > + > + const ETHER_OPS: bindings::ethtool_ops = bindings::ethtool_ops { > + get_ts_info: if <T>::HAS_GET_TS_INFO { > + Some(Self::get_ts_info_callback) > + } else { > + None > + }, > + ..unsafe { core::mem::MaybeUninit::<bindings::ethtool_ops>::zeroed().assume_init() } > + }; > + > + const fn build_ether_ops() -> &'static bindings::ethtool_ops { > + &Self::ETHER_OPS > + } > + > + fn set_ether_ops(&self, dev: &mut Device) { > + // SAFETY: The type invariants guarantee that `dev.0` is valid. > + unsafe { > + (*dev.0).ethtool_ops = Self::build_ether_ops(); > + } > + } > +} > + > +/// Corresponds to the kernel's `struct ethtool_ops`. > +#[vtable] > +pub trait EtherOperations<D: DriverData> { > + /// Corresponds to `get_ts_info` in `struct ethtool_ops`. > + fn get_ts_info( > + _dev: &mut Device, > + _data: <D::Data as ForeignOwnable>::Borrowed<'_>, > + _info: &mut EthtoolTsInfo, > + ) -> Result { > + Err(Error::from_errno(bindings::EOPNOTSUPP as i32)) > + } > +} > + > +/// Corresponds to the kernel's `struct ethtool_ts_info`. > +/// > +/// # Invariants > +/// > +/// The pointer is valid. > +pub struct EthtoolTsInfo(*mut bindings::ethtool_ts_info); > + > +impl EthtoolTsInfo { > + /// Creates a new `EthtoolTsInfo' instance. > + /// > + /// # Safety > + /// > + /// Callers must ensure that `ptr` must be valid. > + unsafe fn from_ptr(ptr: *mut bindings::ethtool_ts_info) -> Self { > + // INVARIANT: The safety requirements ensure the invariant. > + Self(ptr) > + } > +} > + > +/// Sets up the info for software timestamping. > +pub fn ethtool_op_get_ts_info(dev: &mut Device, info: &mut EthtoolTsInfo) -> Result { > + // SAFETY: The type invariants guarantee that `dev.0` and `info.0` are valid. > + unsafe { > + bindings::ethtool_op_get_ts_info(dev.0, info.0); > + } > + Ok(()) > +} > -- > 2.34.1 >
On 6/13/23 06:53, FUJITA Tomonori wrote: > This improves abstractions for network device drivers to implement > struct ethtool_ops, the majority of ethernet device drivers need to > do. > > struct ethtool_ops also needs to access to device private data like > struct net_devicve_ops. > > Currently, only get_ts_info operation is supported. The following > patch adds the Rust version of the dummy network driver, which uses > the operation. > > Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com> > --- > rust/bindings/bindings_helper.h | 1 + > rust/kernel/net/dev.rs | 108 ++++++++++++++++++++++++++++++++ > 2 files changed, 109 insertions(+) > > diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h > index 468bf606f174..6446ff764980 100644 > --- a/rust/bindings/bindings_helper.h > +++ b/rust/bindings/bindings_helper.h > @@ -8,6 +8,7 @@ > > #include <linux/errname.h> > #include <linux/etherdevice.h> > +#include <linux/ethtool.h> > #include <linux/netdevice.h> > #include <linux/slab.h> > #include <linux/refcount.h> > diff --git a/rust/kernel/net/dev.rs b/rust/kernel/net/dev.rs > index d072c81f99ce..d6012b2eea33 100644 > --- a/rust/kernel/net/dev.rs > +++ b/rust/kernel/net/dev.rs > @@ -141,6 +141,18 @@ pub fn register(&mut self) -> Result { > } > } > > + /// Sets `ethtool_ops` of `net_device`. > + pub fn set_ether_operations<U>(&mut self) -> Result > + where > + U: EtherOperations<D>, > + { > + if self.is_registered { > + return Err(code::EINVAL); > + } > + EtherOperationsAdapter::<U, D>::new().set_ether_ops(&mut self.dev); > + Ok(()) > + } Is it really necessary for a device to be able to have multiple different `EtherOperations`? Couldnt you also just make `T` implement `EtherOperations<D>`? > + > const DEVICE_OPS: bindings::net_device_ops = bindings::net_device_ops { > ndo_init: if <T>::HAS_INIT { > Some(Self::init_callback) > @@ -342,3 +354,99 @@ fn drop(&mut self) { > } > } > } > + > +/// Builds the kernel's `struct ethtool_ops`. > +struct EtherOperationsAdapter<D, T> { > + _p: PhantomData<(D, T)>, > +} > + > +impl<D, T> EtherOperationsAdapter<T, D> I think it would be a good idea to add a comment here that explains why this is needed, i.e. why `ETHER_OPS` cannot be implemented via a constant in `set_ether_ops`. > +where > + D: DriverData, > + T: EtherOperations<D>, > +{ > + /// Creates a new instance. > + fn new() -> Self { > + EtherOperationsAdapter { _p: PhantomData } > + } > + > + unsafe extern "C" fn get_ts_info_callback( > + netdev: *mut bindings::net_device, > + info: *mut bindings::ethtool_ts_info, > + ) -> core::ffi::c_int { > + from_result(|| { > + // SAFETY: The C API guarantees that `netdev` is valid while this function is running. > + let mut dev = unsafe { Device::from_ptr(netdev) }; > + // SAFETY: The returned pointer was initialized by `D::Data::into_foreign` when > + // `Registration` object was created. > + // `D::Data::from_foreign` is only called by the object was released. > + // So we know `data` is valid while this function is running. > + let data = unsafe { D::Data::borrow(dev.priv_data_ptr()) }; > + // SAFETY: The C API guarantees that `info` is valid while this function is running. > + let mut info = unsafe { EthtoolTsInfo::from_ptr(info) }; > + T::get_ts_info(&mut dev, data, &mut info)?; > + Ok(0) > + }) > + } > + > + const ETHER_OPS: bindings::ethtool_ops = bindings::ethtool_ops { > + get_ts_info: if <T>::HAS_GET_TS_INFO { > + Some(Self::get_ts_info_callback) > + } else { > + None > + }, > + ..unsafe { core::mem::MaybeUninit::<bindings::ethtool_ops>::zeroed().assume_init() } > + }; > + > + const fn build_ether_ops() -> &'static bindings::ethtool_ops { > + &Self::ETHER_OPS > + } Why is this a function? > + > + fn set_ether_ops(&self, dev: &mut Device) { > + // SAFETY: The type invariants guarantee that `dev.0` is valid. > + unsafe { > + (*dev.0).ethtool_ops = Self::build_ether_ops(); > + } > + } > +} > + > +/// Corresponds to the kernel's `struct ethtool_ops`. > +#[vtable] > +pub trait EtherOperations<D: DriverData> { > + /// Corresponds to `get_ts_info` in `struct ethtool_ops`. > + fn get_ts_info( > + _dev: &mut Device, > + _data: <D::Data as ForeignOwnable>::Borrowed<'_>, > + _info: &mut EthtoolTsInfo, `&mut EthtoolTsInfo` is again a double pointer. > + ) -> Result { > + Err(Error::from_errno(bindings::EOPNOTSUPP as i32)) > + } > +} > + > +/// Corresponds to the kernel's `struct ethtool_ts_info`. > +/// > +/// # Invariants > +/// > +/// The pointer is valid. > +pub struct EthtoolTsInfo(*mut bindings::ethtool_ts_info); > + > +impl EthtoolTsInfo { > + /// Creates a new `EthtoolTsInfo' instance. > + /// > + /// # Safety > + /// > + /// Callers must ensure that `ptr` must be valid. > + unsafe fn from_ptr(ptr: *mut bindings::ethtool_ts_info) -> Self { > + // INVARIANT: The safety requirements ensure the invariant. > + Self(ptr) > + } > +} > + > +/// Sets up the info for software timestamping. > +pub fn ethtool_op_get_ts_info(dev: &mut Device, info: &mut EthtoolTsInfo) -> Result { > + // SAFETY: The type invariants guarantee that `dev.0` and `info.0` are valid. > + unsafe { > + bindings::ethtool_op_get_ts_info(dev.0, info.0); > + } > + Ok(()) > +} Why isn't this an associated function on `EthtoolTsInfo`? -- Cheers, Benno > -- > 2.34.1 >
> > + /// Sets `ethtool_ops` of `net_device`. > > + pub fn set_ether_operations<U>(&mut self) -> Result > > + where > > + U: EtherOperations<D>, > > + { > > + if self.is_registered { > > + return Err(code::EINVAL); > > + } > > + EtherOperationsAdapter::<U, D>::new().set_ether_ops(&mut self.dev); > > + Ok(()) > > + } > > Is it really necessary for a device to be able to have multiple different > `EtherOperations`? Couldnt you also just make `T` implement > `EtherOperations<D>`? For 99% of drivers, netdev->ethtool_ops is set once before register_netdev() is called and never changed. There is one corner case i know of, and it is a hack: https://elixir.bootlin.com/linux/v6.4-rc6/source/net/dsa/master.c#L223 Since this is a hack, you can probably skip it in rust. Andrew
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index 468bf606f174..6446ff764980 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -8,6 +8,7 @@ #include <linux/errname.h> #include <linux/etherdevice.h> +#include <linux/ethtool.h> #include <linux/netdevice.h> #include <linux/slab.h> #include <linux/refcount.h> diff --git a/rust/kernel/net/dev.rs b/rust/kernel/net/dev.rs index d072c81f99ce..d6012b2eea33 100644 --- a/rust/kernel/net/dev.rs +++ b/rust/kernel/net/dev.rs @@ -141,6 +141,18 @@ pub fn register(&mut self) -> Result { } } + /// Sets `ethtool_ops` of `net_device`. + pub fn set_ether_operations<U>(&mut self) -> Result + where + U: EtherOperations<D>, + { + if self.is_registered { + return Err(code::EINVAL); + } + EtherOperationsAdapter::<U, D>::new().set_ether_ops(&mut self.dev); + Ok(()) + } + const DEVICE_OPS: bindings::net_device_ops = bindings::net_device_ops { ndo_init: if <T>::HAS_INIT { Some(Self::init_callback) @@ -342,3 +354,99 @@ fn drop(&mut self) { } } } + +/// Builds the kernel's `struct ethtool_ops`. +struct EtherOperationsAdapter<D, T> { + _p: PhantomData<(D, T)>, +} + +impl<D, T> EtherOperationsAdapter<T, D> +where + D: DriverData, + T: EtherOperations<D>, +{ + /// Creates a new instance. + fn new() -> Self { + EtherOperationsAdapter { _p: PhantomData } + } + + unsafe extern "C" fn get_ts_info_callback( + netdev: *mut bindings::net_device, + info: *mut bindings::ethtool_ts_info, + ) -> core::ffi::c_int { + from_result(|| { + // SAFETY: The C API guarantees that `netdev` is valid while this function is running. + let mut dev = unsafe { Device::from_ptr(netdev) }; + // SAFETY: The returned pointer was initialized by `D::Data::into_foreign` when + // `Registration` object was created. + // `D::Data::from_foreign` is only called by the object was released. + // So we know `data` is valid while this function is running. + let data = unsafe { D::Data::borrow(dev.priv_data_ptr()) }; + // SAFETY: The C API guarantees that `info` is valid while this function is running. + let mut info = unsafe { EthtoolTsInfo::from_ptr(info) }; + T::get_ts_info(&mut dev, data, &mut info)?; + Ok(0) + }) + } + + const ETHER_OPS: bindings::ethtool_ops = bindings::ethtool_ops { + get_ts_info: if <T>::HAS_GET_TS_INFO { + Some(Self::get_ts_info_callback) + } else { + None + }, + ..unsafe { core::mem::MaybeUninit::<bindings::ethtool_ops>::zeroed().assume_init() } + }; + + const fn build_ether_ops() -> &'static bindings::ethtool_ops { + &Self::ETHER_OPS + } + + fn set_ether_ops(&self, dev: &mut Device) { + // SAFETY: The type invariants guarantee that `dev.0` is valid. + unsafe { + (*dev.0).ethtool_ops = Self::build_ether_ops(); + } + } +} + +/// Corresponds to the kernel's `struct ethtool_ops`. +#[vtable] +pub trait EtherOperations<D: DriverData> { + /// Corresponds to `get_ts_info` in `struct ethtool_ops`. + fn get_ts_info( + _dev: &mut Device, + _data: <D::Data as ForeignOwnable>::Borrowed<'_>, + _info: &mut EthtoolTsInfo, + ) -> Result { + Err(Error::from_errno(bindings::EOPNOTSUPP as i32)) + } +} + +/// Corresponds to the kernel's `struct ethtool_ts_info`. +/// +/// # Invariants +/// +/// The pointer is valid. +pub struct EthtoolTsInfo(*mut bindings::ethtool_ts_info); + +impl EthtoolTsInfo { + /// Creates a new `EthtoolTsInfo' instance. + /// + /// # Safety + /// + /// Callers must ensure that `ptr` must be valid. + unsafe fn from_ptr(ptr: *mut bindings::ethtool_ts_info) -> Self { + // INVARIANT: The safety requirements ensure the invariant. + Self(ptr) + } +} + +/// Sets up the info for software timestamping. +pub fn ethtool_op_get_ts_info(dev: &mut Device, info: &mut EthtoolTsInfo) -> Result { + // SAFETY: The type invariants guarantee that `dev.0` and `info.0` are valid. + unsafe { + bindings::ethtool_op_get_ts_info(dev.0, info.0); + } + Ok(()) +}
This improves abstractions for network device drivers to implement struct ethtool_ops, the majority of ethernet device drivers need to do. struct ethtool_ops also needs to access to device private data like struct net_devicve_ops. Currently, only get_ts_info operation is supported. The following patch adds the Rust version of the dummy network driver, which uses the operation. Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com> --- rust/bindings/bindings_helper.h | 1 + rust/kernel/net/dev.rs | 108 ++++++++++++++++++++++++++++++++ 2 files changed, 109 insertions(+)