From patchwork Tue Oct 17 11:30:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: FUJITA Tomonori X-Patchwork-Id: 13425047 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2C1FC41AB6; Tue, 17 Oct 2023 11:30:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="jZdL7o4A" Received: from mail-pj1-x102b.google.com (mail-pj1-x102b.google.com [IPv6:2607:f8b0:4864:20::102b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A34BF0; Tue, 17 Oct 2023 04:30:24 -0700 (PDT) Received: by mail-pj1-x102b.google.com with SMTP id 98e67ed59e1d1-27d21168d26so844039a91.0; Tue, 17 Oct 2023 04:30:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1697542224; x=1698147024; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=3p/voU7+p+W9kFHgMQfueK4JerIA8fAw3PI5x6LcPac=; b=jZdL7o4Acxa41GxzA3P4efi1CRBp68FMAHeO1GFM7RSvfgwb7NtHjqAzmxX/rVe0ZN YOjJSJWUgM6fN3g2f+NW9+MREd+/UreimL6jpSdlPUeU09vhWqnYPveFa0JYfhpdFhuN LZLhuAXp7gwZ152Xrl+kSOl+w2HAq4MaY8WL2JhmcuTHTlwO7YomMJXB3FrQaZW1ihw9 xXp+a1SmNBFgn+e9c+gy4nrRs8SDjz2TPsMCCMYQcS+4f1WMAHusSKGM7JN1JbDTrfg2 o9PS1MtznYIYVQhoX9JdZfvXVNVKd5U+d6igYVjFGejEg4W6OnIVxGxYEflwNPu2RPCh irsw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697542224; x=1698147024; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=3p/voU7+p+W9kFHgMQfueK4JerIA8fAw3PI5x6LcPac=; b=s5NT/oznYoVUXVhz2tBtnvuNagCwra8ninnAut8Lj49GIIMjbQG8sNUuJEqyZHaoho wj43j6OgZ9cnGrvUMT0ED/NTacK3zmqMb213alewAFVttyq+PhfDMLR3l/AYZ3tY+KW7 to1yeQHXScrVQ+CmcVuduGjMJ92tdk9ldGZoXjsuIYL88s42SDOef2bSiPeWAXGowRcu GXNM7vNXO3tGTNW1lI+9LC/M/pjsTiwGWMslxBjgdsM41rzJsg81k/DOlU46P7PGpSRn 1/+6wCowAKG2TQuLjVyEXpPejcxuaHjfWBqx7Y87d1/ojKjv/2NYRZVPi6McVxx/Sb8s pfbg== X-Gm-Message-State: AOJu0Yy9Ls06lN2tX3TEaTn7lnRM9YCDwozOgFua0InxGxICoBmcCEPB azbVkKbJMLWUrNE3jsmrwM+SNZbz82xW/ZLv X-Google-Smtp-Source: AGHT+IFP0Tr8UCZKrAspEUQJA68VOvFeH74MMsB+eGP3qIQC9wV2g4g6XcKannFk7ePuB0shFnv2oA== X-Received: by 2002:a17:90b:3802:b0:27c:f653:37b2 with SMTP id mq2-20020a17090b380200b0027cf65337b2mr2001830pjb.1.1697542223472; Tue, 17 Oct 2023 04:30:23 -0700 (PDT) Received: from ip-172-30-47-114.us-west-2.compute.internal (ec2-54-68-170-188.us-west-2.compute.amazonaws.com. [54.68.170.188]) by smtp.gmail.com with ESMTPSA id r16-20020a17090ad41000b002635db431a0sm1116277pju.45.2023.10.17.04.30.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Oct 2023 04:30:23 -0700 (PDT) From: FUJITA Tomonori To: netdev@vger.kernel.org Cc: rust-for-linux@vger.kernel.org, andrew@lunn.ch, miguel.ojeda.sandonis@gmail.com, tmgross@umich.edu, boqun.feng@gmail.com, wedsonaf@gmail.com, benno.lossin@proton.me, greg@kroah.com Subject: [PATCH net-next v5 1/5] rust: core abstractions for network PHY drivers Date: Tue, 17 Oct 2023 20:30:10 +0900 Message-Id: <20231017113014.3492773-2-fujita.tomonori@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231017113014.3492773-1-fujita.tomonori@gmail.com> References: <20231017113014.3492773-1-fujita.tomonori@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org This patch adds abstractions to implement network PHY drivers; the driver registration and bindings for some of callback functions in struct phy_driver and many genphy_ functions. This feature is enabled with CONFIG_RUST_PHYLIB_ABSTRACTIONS=y. This patch enables unstable const_maybe_uninit_zeroed feature for kernel crate to enable unsafe code to handle a constant value with uninitialized data. With the feature, the abstractions can initialize a phy_driver structure with zero easily; instead of initializing all the members by hand. It's supposed to be stable in the not so distant future. Link: https://github.com/rust-lang/rust/pull/116218 Signed-off-by: FUJITA Tomonori --- drivers/net/phy/Kconfig | 8 + rust/bindings/bindings_helper.h | 3 + rust/kernel/lib.rs | 3 + rust/kernel/net.rs | 6 + rust/kernel/net/phy.rs | 701 ++++++++++++++++++++++++++++++++ 5 files changed, 721 insertions(+) create mode 100644 rust/kernel/net.rs create mode 100644 rust/kernel/net/phy.rs diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig index 421d2b62918f..0faebdb184ca 100644 --- a/drivers/net/phy/Kconfig +++ b/drivers/net/phy/Kconfig @@ -60,6 +60,14 @@ config FIXED_PHY Currently tested with mpc866ads and mpc8349e-mitx. +config RUST_PHYLIB_ABSTRACTIONS + bool "PHYLIB abstractions support" + depends on RUST + depends on PHYLIB=y + help + Adds support needed for PHY drivers written in Rust. It provides + a wrapper around the C phylib core. + config SFP tristate "SFP cage support" depends on I2C && PHYLINK diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index c91a3c24f607..ec4ee09a34ad 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -8,6 +8,9 @@ #include #include +#include +#include +#include #include #include #include diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index e8811700239a..0588422e273c 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -14,6 +14,7 @@ #![no_std] #![feature(allocator_api)] #![feature(coerce_unsized)] +#![feature(const_maybe_uninit_zeroed)] #![feature(dispatch_from_dyn)] #![feature(new_uninit)] #![feature(receiver_trait)] @@ -36,6 +37,8 @@ pub mod ioctl; #[cfg(CONFIG_KUNIT)] pub mod kunit; +#[cfg(CONFIG_NET)] +pub mod net; pub mod prelude; pub mod print; mod static_assert; diff --git a/rust/kernel/net.rs b/rust/kernel/net.rs new file mode 100644 index 000000000000..fe415cb369d3 --- /dev/null +++ b/rust/kernel/net.rs @@ -0,0 +1,6 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Networking. + +#[cfg(CONFIG_RUST_PHYLIB_ABSTRACTIONS)] +pub mod phy; diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs new file mode 100644 index 000000000000..7d4927ece32f --- /dev/null +++ b/rust/kernel/net/phy.rs @@ -0,0 +1,701 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2023 FUJITA Tomonori + +//! Network PHY device. +//! +//! C headers: [`include/linux/phy.h`](../../../../include/linux/phy.h). +//! +//! The C side (PHYLIB) guarantees that there is only one thread accessing to one `phy_device` instance +//! during a callback in `phy_driver`. The callback safely accesses to the instance exclusively. +//! Except for `resume()` and `suspend()`, PHYLIB holds `phy_device`'s lock during a callback. +//! PHYLIB doesn't hold `phy_device`'s lock in both `resume()` and `suspend()`. Instead, PHYLIB +//! updates `phy_device`'s state with `phy_device`'s lock hold, to guarantee that resume() accesses +//! to the instance exclusively. Note that `resume()` and `suspend()` also are called where only +//! one thread can access to the instance. +//! +//! This abstractions creates [`Device`] instance only during a callback so it's guaranteed that +//! only one reference exists. All its methods can accesses to the instance exclusively. +//! +//! All the PHYLIB helper functions for `phy_device` modify some members in `phy_device`. Except for +//! getter functions, [`Device`] methods take `&mut self`. This also applied to `read()`, which reads +//! a hardware register and updates the stats. + +use crate::{bindings, error::*, prelude::vtable, str::CStr, types::Opaque}; +use core::marker::PhantomData; + +/// Corresponds to the kernel's `enum phy_state`. +#[derive(PartialEq)] +pub enum DeviceState { + /// PHY device and driver are not ready for anything. + Down, + /// PHY is ready to send and receive packets. + Ready, + /// PHY is up, but no polling or interrupts are done. + Halted, + /// PHY is up, but is in an error state. + Error, + /// PHY and attached device are ready to do work. + Up, + /// PHY is currently running. + Running, + /// PHY is up, but not currently plugged in. + NoLink, + /// PHY is performing a cable test. + CableTest, +} + +/// Represents duplex mode. +pub enum DuplexMode { + /// PHY is in full-duplex mode. + Full, + /// PHY is in half-duplex mode. + Half, + /// PHY is in unknown duplex mode. + Unknown, +} + +/// An instance of a PHY device. +/// +/// Wraps the kernel's `struct phy_device`. +/// +/// # Invariants +/// +/// `self.0` is always in a valid state. +#[repr(transparent)] +pub struct Device(Opaque); + +impl Device { + /// Creates a new [`Device`] instance from a raw pointer. + /// + /// # Safety + /// + /// This function must only be called from the callbacks in `phy_driver`. PHYLIB guarantees + /// the exclusive access for the duration of the lifetime `'a`. + unsafe fn from_raw<'a>(ptr: *mut bindings::phy_device) -> &'a mut Self { + // CAST: `Self` is a `repr(transparent)` wrapper around `bindings::phy_device`. + let ptr = ptr.cast::(); + // SAFETY: by the function requirements the pointer is valid and we have unique access for + // the duration of `'a`. + unsafe { &mut *ptr } + } + + /// Gets the id of the PHY. + pub fn phy_id(&self) -> u32 { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + unsafe { (*phydev).phy_id } + } + + /// Gets the state of the PHY. + pub fn state(&self) -> DeviceState { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + let state = unsafe { (*phydev).state }; + // TODO: this conversion code will be replaced with automatically generated code by bindgen + // when it becomes possible. + // better to call WARN_ONCE() when the state is out-of-range (needs to add WARN_ONCE support). + match state { + bindings::phy_state_PHY_DOWN => DeviceState::Down, + bindings::phy_state_PHY_READY => DeviceState::Ready, + bindings::phy_state_PHY_HALTED => DeviceState::Halted, + bindings::phy_state_PHY_ERROR => DeviceState::Error, + bindings::phy_state_PHY_UP => DeviceState::Up, + bindings::phy_state_PHY_RUNNING => DeviceState::Running, + bindings::phy_state_PHY_NOLINK => DeviceState::NoLink, + bindings::phy_state_PHY_CABLETEST => DeviceState::CableTest, + _ => DeviceState::Error, + } + } + + /// Returns true if the link is up. + pub fn get_link(&self) -> bool { + const LINK_IS_UP: u32 = 1; + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + let phydev = unsafe { *self.0.get() }; + phydev.link() == LINK_IS_UP + } + + /// Returns true if auto-negotiation is enabled. + pub fn is_autoneg_enabled(&self) -> bool { + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + let phydev = unsafe { *self.0.get() }; + phydev.autoneg() == bindings::AUTONEG_ENABLE + } + + /// Returns true if auto-negotiation is completed. + pub fn is_autoneg_completed(&self) -> bool { + const AUTONEG_COMPLETED: u32 = 1; + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + let phydev = unsafe { *self.0.get() }; + phydev.autoneg_complete() == AUTONEG_COMPLETED + } + + /// Sets the speed of the PHY. + pub fn set_speed(&mut self, speed: u32) { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + unsafe { (*phydev).speed = speed as i32 }; + } + + /// Sets duplex mode. + pub fn set_duplex(&mut self, mode: DuplexMode) { + let phydev = self.0.get(); + let v = match mode { + DuplexMode::Full => bindings::DUPLEX_FULL as i32, + DuplexMode::Half => bindings::DUPLEX_HALF as i32, + DuplexMode::Unknown => bindings::DUPLEX_UNKNOWN as i32, + }; + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + unsafe { (*phydev).duplex = v }; + } + + /// Reads a given C22 PHY register. + pub fn read(&mut self, regnum: u16) -> Result { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + // So an FFI call with a valid pointer. + let ret = unsafe { + bindings::mdiobus_read((*phydev).mdio.bus, (*phydev).mdio.addr, regnum.into()) + }; + if ret < 0 { + Err(Error::from_errno(ret)) + } else { + Ok(ret as u16) + } + } + + /// Writes a given C22 PHY register. + pub fn write(&mut self, regnum: u16, val: u16) -> Result { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + // So an FFI call with a valid pointer. + to_result(unsafe { + bindings::mdiobus_write((*phydev).mdio.bus, (*phydev).mdio.addr, regnum.into(), val) + }) + } + + /// Reads a paged register. + pub fn read_paged(&mut self, page: u16, regnum: u16) -> Result { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + // So an FFI call with a valid pointer. + let ret = unsafe { bindings::phy_read_paged(phydev, page.into(), regnum.into()) }; + if ret < 0 { + Err(Error::from_errno(ret)) + } else { + Ok(ret as u16) + } + } + + /// Resolves the advertisements into PHY settings. + pub fn resolve_aneg_linkmode(&mut self) { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + // So an FFI call with a valid pointer. + unsafe { bindings::phy_resolve_aneg_linkmode(phydev) }; + } + + /// Executes software reset the PHY via `BMCR_RESET` bit. + pub fn genphy_soft_reset(&mut self) -> Result { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + // So an FFI call with a valid pointer. + to_result(unsafe { bindings::genphy_soft_reset(phydev) }) + } + + /// Initializes the PHY. + pub fn init_hw(&mut self) -> Result { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + // so an FFI call with a valid pointer. + to_result(unsafe { bindings::phy_init_hw(phydev) }) + } + + /// Starts auto-negotiation. + pub fn start_aneg(&mut self) -> Result { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + // So an FFI call with a valid pointer. + to_result(unsafe { bindings::phy_start_aneg(phydev) }) + } + + /// Resumes the PHY via `BMCR_PDOWN` bit. + pub fn genphy_resume(&mut self) -> Result { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + // So an FFI call with a valid pointer. + to_result(unsafe { bindings::genphy_resume(phydev) }) + } + + /// Suspends the PHY via `BMCR_PDOWN` bit. + pub fn genphy_suspend(&mut self) -> Result { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + // So an FFI call with a valid pointer. + to_result(unsafe { bindings::genphy_suspend(phydev) }) + } + + /// Checks the link status and updates current link state. + pub fn genphy_read_status(&mut self) -> Result { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + // So an FFI call with a valid pointer. + let ret = unsafe { bindings::genphy_read_status(phydev) }; + if ret < 0 { + Err(Error::from_errno(ret)) + } else { + Ok(ret as u16) + } + } + + /// Updates the link status. + pub fn genphy_update_link(&mut self) -> Result { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + // So an FFI call with a valid pointer. + to_result(unsafe { bindings::genphy_update_link(phydev) }) + } + + /// Reads link partner ability. + pub fn genphy_read_lpa(&mut self) -> Result { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + // So an FFI call with a valid pointer. + to_result(unsafe { bindings::genphy_read_lpa(phydev) }) + } + + /// Reads PHY abilities. + pub fn genphy_read_abilities(&mut self) -> Result { + let phydev = self.0.get(); + // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`. + // So an FFI call with a valid pointer. + to_result(unsafe { bindings::genphy_read_abilities(phydev) }) + } +} + +/// Defines certain other features this PHY supports (like interrupts). +/// +/// These flag values are used in [`Driver::FLAGS`]. +pub mod flags { + /// PHY is internal. + pub const IS_INTERNAL: u32 = bindings::PHY_IS_INTERNAL; + /// PHY needs to be reset after the refclk is enabled. + pub const RST_AFTER_CLK_EN: u32 = bindings::PHY_RST_AFTER_CLK_EN; + /// Polling is used to detect PHY status changes. + pub const POLL_CABLE_TEST: u32 = bindings::PHY_POLL_CABLE_TEST; + /// Don't suspend. + pub const ALWAYS_CALL_SUSPEND: u32 = bindings::PHY_ALWAYS_CALL_SUSPEND; +} + +/// An adapter for the registration of a PHY driver. +struct Adapter { + _p: PhantomData, +} + +impl Adapter { + /// # Safety + /// + /// `phydev` must be passed by the corresponding callback in `phy_driver`. + unsafe extern "C" fn soft_reset_callback( + phydev: *mut bindings::phy_device, + ) -> core::ffi::c_int { + from_result(|| { + // SAFETY: Preconditions ensure `phydev` is valid. + let dev = unsafe { Device::from_raw(phydev) }; + T::soft_reset(dev)?; + Ok(0) + }) + } + + /// # Safety + /// + /// `phydev` must be passed by the corresponding callback in `phy_driver`. + unsafe extern "C" fn get_features_callback( + phydev: *mut bindings::phy_device, + ) -> core::ffi::c_int { + from_result(|| { + // SAFETY: Preconditions ensure `phydev` is valid. + let dev = unsafe { Device::from_raw(phydev) }; + T::get_features(dev)?; + Ok(0) + }) + } + + /// # Safety + /// + /// `phydev` must be passed by the corresponding callback in `phy_driver`. + unsafe extern "C" fn suspend_callback(phydev: *mut bindings::phy_device) -> core::ffi::c_int { + from_result(|| { + // SAFETY: Preconditions ensure `phydev` is valid. + let dev = unsafe { Device::from_raw(phydev) }; + T::suspend(dev)?; + Ok(0) + }) + } + + /// # Safety + /// + /// `phydev` must be passed by the corresponding callback in `phy_driver`. + unsafe extern "C" fn resume_callback(phydev: *mut bindings::phy_device) -> core::ffi::c_int { + from_result(|| { + // SAFETY: Preconditions ensure `phydev` is valid. + let dev = unsafe { Device::from_raw(phydev) }; + T::resume(dev)?; + Ok(0) + }) + } + + /// # Safety + /// + /// `phydev` must be passed by the corresponding callback in `phy_driver`. + unsafe extern "C" fn config_aneg_callback( + phydev: *mut bindings::phy_device, + ) -> core::ffi::c_int { + from_result(|| { + // SAFETY: Preconditions ensure `phydev` is valid. + let dev = unsafe { Device::from_raw(phydev) }; + T::config_aneg(dev)?; + Ok(0) + }) + } + + /// # Safety + /// + /// `phydev` must be passed by the corresponding callback in `phy_driver`. + unsafe extern "C" fn read_status_callback( + phydev: *mut bindings::phy_device, + ) -> core::ffi::c_int { + from_result(|| { + // SAFETY: Preconditions ensure `phydev` is valid. + let dev = unsafe { Device::from_raw(phydev) }; + T::read_status(dev)?; + Ok(0) + }) + } + + /// # Safety + /// + /// `phydev` must be passed by the corresponding callback in `phy_driver`. + unsafe extern "C" fn match_phy_device_callback( + phydev: *mut bindings::phy_device, + ) -> core::ffi::c_int { + // SAFETY: Preconditions ensure `phydev` is valid. + let dev = unsafe { Device::from_raw(phydev) }; + T::match_phy_device(dev) as i32 + } + + /// # Safety + /// + /// `phydev` must be passed by the corresponding callback in `phy_driver`. + unsafe extern "C" fn read_mmd_callback( + phydev: *mut bindings::phy_device, + devnum: i32, + regnum: u16, + ) -> i32 { + from_result(|| { + // SAFETY: Preconditions ensure `phydev` is valid. + let dev = unsafe { Device::from_raw(phydev) }; + // CAST: the C side verifies devnum < 32. + let ret = T::read_mmd(dev, devnum as u8, regnum)?; + Ok(ret.into()) + }) + } + + /// # Safety + /// + /// `phydev` must be passed by the corresponding callback in `phy_driver`. + unsafe extern "C" fn write_mmd_callback( + phydev: *mut bindings::phy_device, + devnum: i32, + regnum: u16, + val: u16, + ) -> i32 { + from_result(|| { + // SAFETY: Preconditions ensure `phydev` is valid. + let dev = unsafe { Device::from_raw(phydev) }; + T::write_mmd(dev, devnum as u8, regnum, val)?; + Ok(0) + }) + } + + /// # Safety + /// + /// `phydev` must be passed by the corresponding callback in `phy_driver`. + unsafe extern "C" fn link_change_notify_callback(phydev: *mut bindings::phy_device) { + // SAFETY: Preconditions ensure `phydev` is valid. + let dev = unsafe { Device::from_raw(phydev) }; + T::link_change_notify(dev); + } +} + +/// An instance of a PHY driver. +/// +/// Wraps the kernel's `struct phy_driver`. +/// +/// # Invariants +/// +/// `self.0` is always in a valid state. +#[repr(transparent)] +pub struct DriverType(Opaque); + +/// Creates the kernel's `phy_driver` instance. +/// +/// This is used by [`module_phy_driver`] macro to create a static array of `phy_driver`. +/// +/// [`module_phy_driver`]: crate::module_phy_driver +pub const fn create_phy_driver() -> DriverType { + // All the fields of `struct phy_driver` are initialized properly. + // It ensures the invariants. + DriverType(Opaque::new(bindings::phy_driver { + name: T::NAME.as_char_ptr().cast_mut(), + flags: T::FLAGS, + phy_id: T::PHY_DEVICE_ID.id, + phy_id_mask: T::PHY_DEVICE_ID.mask_as_int(), + soft_reset: if T::HAS_SOFT_RESET { + Some(Adapter::::soft_reset_callback) + } else { + None + }, + get_features: if T::HAS_GET_FEATURES { + Some(Adapter::::get_features_callback) + } else { + None + }, + match_phy_device: if T::HAS_MATCH_PHY_DEVICE { + Some(Adapter::::match_phy_device_callback) + } else { + None + }, + suspend: if T::HAS_SUSPEND { + Some(Adapter::::suspend_callback) + } else { + None + }, + resume: if T::HAS_RESUME { + Some(Adapter::::resume_callback) + } else { + None + }, + config_aneg: if T::HAS_CONFIG_ANEG { + Some(Adapter::::config_aneg_callback) + } else { + None + }, + read_status: if T::HAS_READ_STATUS { + Some(Adapter::::read_status_callback) + } else { + None + }, + read_mmd: if T::HAS_READ_MMD { + Some(Adapter::::read_mmd_callback) + } else { + None + }, + write_mmd: if T::HAS_WRITE_MMD { + Some(Adapter::::write_mmd_callback) + } else { + None + }, + link_change_notify: if T::HAS_LINK_CHANGE_NOTIFY { + Some(Adapter::::link_change_notify_callback) + } else { + None + }, + // SAFETY: The rest is zeroed out to initialize `struct phy_driver`, + // sets `Option<&F>` to be `None`. + ..unsafe { core::mem::MaybeUninit::::zeroed().assume_init() } + })) +} + +/// Corresponds to functions in `struct phy_driver`. +/// +/// This is used to register a PHY driver. +#[vtable] +pub trait Driver { + /// Defines certain other features this PHY supports. + /// It is a combination of the flags in the [`flags`] module. + const FLAGS: u32 = 0; + + /// The friendly name of this PHY type. + const NAME: &'static CStr; + + /// This driver only works for PHYs with IDs which match this field. + /// The default id and mask are zero. + const PHY_DEVICE_ID: DeviceId = DeviceId::new_with_custom_mask(0, 0); + + /// Issues a PHY software reset. + fn soft_reset(_dev: &mut Device) -> Result { + Err(code::ENOTSUPP) + } + + /// Probes the hardware to determine what abilities it has. + fn get_features(_dev: &mut Device) -> Result { + Err(code::ENOTSUPP) + } + + /// Returns true if this is a suitable driver for the given phydev. + /// If not implemented, matching is based on [`Driver::PHY_DEVICE_ID`]. + fn match_phy_device(_dev: &Device) -> bool { + false + } + + /// Configures the advertisement and resets auto-negotiation + /// if auto-negotiation is enabled. + fn config_aneg(_dev: &mut Device) -> Result { + Err(code::ENOTSUPP) + } + + /// Determines the negotiated speed and duplex. + fn read_status(_dev: &mut Device) -> Result { + Err(code::ENOTSUPP) + } + + /// Suspends the hardware, saving state if needed. + fn suspend(_dev: &mut Device) -> Result { + Err(code::ENOTSUPP) + } + + /// Resumes the hardware, restoring state if needed. + fn resume(_dev: &mut Device) -> Result { + Err(code::ENOTSUPP) + } + + /// Overrides the default MMD read function for reading a MMD register. + fn read_mmd(_dev: &mut Device, _devnum: u8, _regnum: u16) -> Result { + Err(code::ENOTSUPP) + } + + /// Overrides the default MMD write function for writing a MMD register. + fn write_mmd(_dev: &mut Device, _devnum: u8, _regnum: u16, _val: u16) -> Result { + Err(code::ENOTSUPP) + } + + /// Callback for notification of link change. + fn link_change_notify(_dev: &mut Device) {} +} + +/// Registration structure for a PHY driver. +/// +/// # Invariants +/// +/// The `drivers` slice are currently registered to the kernel via `phy_drivers_register`. +pub struct Registration { + drivers: &'static [DriverType], +} + +impl Registration { + /// Registers a PHY driver. + pub fn register( + module: &'static crate::ThisModule, + drivers: &'static [DriverType], + ) -> Result { + if drivers.is_empty() { + return Err(code::EINVAL); + } + // SAFETY: The type invariants of [`DriverType`] ensure that all elements of the `drivers` slice + // are initialized properly. So an FFI call with a valid pointer. + to_result(unsafe { + bindings::phy_drivers_register(drivers[0].0.get(), drivers.len().try_into()?, module.0) + })?; + // INVARIANT: The `drivers` slice is successfully registered to the kernel via `phy_drivers_register`. + Ok(Registration { drivers }) + } +} + +impl Drop for Registration { + fn drop(&mut self) { + // SAFETY: The type invariants guarantee that `self.drivers` is valid. + // So an FFI call with a valid pointer. + unsafe { + bindings::phy_drivers_unregister(self.drivers[0].0.get(), self.drivers.len() as i32) + }; + } +} + +// SAFETY: `Registration` does not expose any of its state across threads. +unsafe impl Send for Registration {} + +// SAFETY: `Registration` does not expose any of its state across threads. +unsafe impl Sync for Registration {} + +/// Represents the kernel's `struct mdio_device_id`. +pub struct DeviceId { + id: u32, + mask: DeviceMask, +} + +impl DeviceId { + /// Creates a new instance with the exact match mask. + pub const fn new_with_exact_mask(id: u32) -> Self { + DeviceId { + id, + mask: DeviceMask::Exact, + } + } + + /// Creates a new instance with the model match mask. + pub const fn new_with_model_mask(id: u32) -> Self { + DeviceId { + id, + mask: DeviceMask::Model, + } + } + + /// Creates a new instance with the vendor match mask. + pub const fn new_with_vendor_mask(id: u32) -> Self { + DeviceId { + id, + mask: DeviceMask::Vendor, + } + } + + /// Creates a new instance with a custom match mask. + pub const fn new_with_custom_mask(id: u32, mask: u32) -> Self { + DeviceId { + id, + mask: DeviceMask::Custom(mask), + } + } + + /// Creates a new instance from [`Driver`]. + pub const fn new_with_driver() -> Self { + T::PHY_DEVICE_ID + } + + /// Get a `mask` as u32. + pub const fn mask_as_int(&self) -> u32 { + self.mask.as_int() + } + + // macro use only + #[doc(hidden)] + pub const fn mdio_device_id(&self) -> bindings::mdio_device_id { + bindings::mdio_device_id { + phy_id: self.id, + phy_id_mask: self.mask.as_int(), + } + } +} + +enum DeviceMask { + Exact, + Model, + Vendor, + Custom(u32), +} + +impl DeviceMask { + const MASK_EXACT: u32 = !0; + const MASK_MODEL: u32 = !0 << 4; + const MASK_VENDOR: u32 = !0 << 10; + + const fn as_int(&self) -> u32 { + match self { + DeviceMask::Exact => Self::MASK_EXACT, + DeviceMask::Model => Self::MASK_MODEL, + DeviceMask::Vendor => Self::MASK_VENDOR, + DeviceMask::Custom(mask) => *mask, + } + } +}