Re: [PATCH net-next v7 1/5] rust: core abstractions for network PHY drivers
From: Boqun Feng <hidden>
Date: 2023-10-27 20:00:43
Also in:
rust-for-linux
On Thu, Oct 26, 2023 at 09:10:46AM +0900, FUJITA Tomonori wrote: [...]
+ /// Gets the current link state.
+ ///
+ /// It returns true if the link is up.
+ pub fn is_link_up(&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() };
Tomo, FWIW, the above line means *copying* the content pointed by
`self.0.get()` into `phydev`, i.e. `phydev` is the semantically a copy
of the `phy_device` instead of an alias. In C code, it means you did:
struct phy_device phydev = *ptr;
Sure, both compilers can figure this out, therefore no extra copy is
done, but still it's better to avoid this copy semantics by doing:
let phydev = unsafe { &*self.0.get() };
it's equal to C code:
struct phy_device *phydev = ptr;
Ditto for is_autoneg_enabled() and is_autoneg_completed().
Regards,
Boqun
+ phydev.link() == LINK_IS_UP
+ }
+
+ /// Gets the current auto-negotiation configuration.
+ ///
+ /// It 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
+ }
+
+ /// Gets the current auto-negotiation state.
+ ///
+ /// It 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
+ }[...]