[PATCH v1] rust: time: rename ClockSource trait to ClockId

[FUJITA Tomonori <tomo@flapping.org>]

From: FUJITA Tomonori <fujita.tomonori@gmail.com>

The `ClockSource` trait has nothing to do with the C `struct clocksource`
in `include/linux/clocksource.h`, which abstracts the hardware counter
used as a source of time for the majority of the clockids. The trait
instead carries a `clockid_t` `ID`, i.e. one of the IDs of "the various
system clocks (for POSIX.1b interval timers)" as described in
include/uapi/linux/time.h (CLOCK_MONOTONIC, CLOCK_REALTIME, ...). It thus
plays the role of a `clockid_t`, and the `ClockSource` name overlaps
confusingly with the C `clocksource` concept when reading across C and
Rust code.

Rename the trait to `ClockId` to reflect that it represents a
`clockid_t`. This is a pure rename; there is no functional change.

Suggested-by: John Stultz <jstultz@google.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Link: https://lore.kernel.org/rust-for-linux/CANDhNCrKMdHCmL76LWCROVF2Ly-9NxmfmQ2T+P=iv34aVkO2uQ@mail.gmail.com/
---
 rust/kernel/time.rs         | 34 +++++++--------
 rust/kernel/time/hrtimer.rs | 82 ++++++++++++++++++-------------------
 2 files changed, 58 insertions(+), 58 deletions(-)

diff --git a/rust/kernel/time.rs b/rust/kernel/time.rs
index 363e93cbb139..4fecab6692b6 100644
--- a/rust/kernel/time.rs
+++ b/rust/kernel/time.rs
@@ -53,9 +53,9 @@ pub fn msecs_to_jiffies(msecs: Msecs) -> Jiffies {
     unsafe { bindings::__msecs_to_jiffies(msecs) }
 }
 
-/// Trait for clock sources.
+/// Trait for kernel clock identifiers.
 ///
-/// Selection of the clock source depends on the use case. In some cases the usage of a
+/// Selection of the clock depends on the use case. In some cases the usage of a
 /// particular clock is mandatory, e.g. in network protocols, filesystems. In other
 /// cases the user of the clock has to decide which clock is best suited for the
 /// purpose. In most scenarios clock [`Monotonic`] is the best choice as it
@@ -66,13 +66,13 @@ pub fn msecs_to_jiffies(msecs: Msecs) -> Jiffies {
 /// Implementers must ensure that `ktime_get()` returns a value in the inclusive range
 /// `0..=KTIME_MAX` (i.e., greater than or equal to 0 and less than or equal to
 /// `KTIME_MAX`, where `KTIME_MAX` equals `i64::MAX`).
-pub unsafe trait ClockSource {
-    /// The kernel clock ID associated with this clock source.
+pub unsafe trait ClockId {
+    /// The kernel clock ID associated with this clock.
     ///
     /// This constant corresponds to the C side `clockid_t` value.
     const ID: bindings::clockid_t;
 
-    /// Get the current time from the clock source.
+    /// Get the current time from the clock.
     ///
     /// The function must return a value in the range `0..=KTIME_MAX`.
     fn ktime_get() -> bindings::ktime_t;
@@ -93,7 +93,7 @@ pub unsafe trait ClockSource {
 
 // SAFETY: The kernel's `ktime_get()` is guaranteed to return a value
 // in `0..=KTIME_MAX`.
-unsafe impl ClockSource for Monotonic {
+unsafe impl ClockId for Monotonic {
     const ID: bindings::clockid_t = bindings::CLOCK_MONOTONIC as bindings::clockid_t;
 
     fn ktime_get() -> bindings::ktime_t {
@@ -120,7 +120,7 @@ fn ktime_get() -> bindings::ktime_t {
 
 // SAFETY: The kernel's `ktime_get_real()` is guaranteed to return a value
 // in `0..=KTIME_MAX`.
-unsafe impl ClockSource for RealTime {
+unsafe impl ClockId for RealTime {
     const ID: bindings::clockid_t = bindings::CLOCK_REALTIME as bindings::clockid_t;
 
     fn ktime_get() -> bindings::ktime_t {
@@ -140,7 +140,7 @@ fn ktime_get() -> bindings::ktime_t {
 
 // SAFETY: The kernel's `ktime_get_boottime()` is guaranteed to return a value
 // in `0..=KTIME_MAX`.
-unsafe impl ClockSource for BootTime {
+unsafe impl ClockId for BootTime {
     const ID: bindings::clockid_t = bindings::CLOCK_BOOTTIME as bindings::clockid_t;
 
     fn ktime_get() -> bindings::ktime_t {
@@ -164,7 +164,7 @@ fn ktime_get() -> bindings::ktime_t {
 
 // SAFETY: The kernel's `ktime_get_clocktai()` is guaranteed to return a value
 // in `0..=KTIME_MAX`.
-unsafe impl ClockSource for Tai {
+unsafe impl ClockId for Tai {
     const ID: bindings::clockid_t = bindings::CLOCK_TAI as bindings::clockid_t;
 
     fn ktime_get() -> bindings::ktime_t {
@@ -180,24 +180,24 @@ fn ktime_get() -> bindings::ktime_t {
 /// The `inner` value is in the range from 0 to `KTIME_MAX`.
 #[repr(transparent)]
 #[derive(PartialEq, PartialOrd, Eq, Ord)]
-pub struct Instant<C: ClockSource> {
+pub struct Instant<C: ClockId> {
     inner: bindings::ktime_t,
     _c: PhantomData<C>,
 }
 
-impl<C: ClockSource> Clone for Instant<C> {
+impl<C: ClockId> Clone for Instant<C> {
     fn clone(&self) -> Self {
         *self
     }
 }
 
-impl<C: ClockSource> Copy for Instant<C> {}
+impl<C: ClockId> Copy for Instant<C> {}
 
-impl<C: ClockSource> Instant<C> {
+impl<C: ClockId> Instant<C> {
     /// Get the current time from the clock source.
     #[inline]
     pub fn now() -> Self {
-        // INVARIANT: The `ClockSource::ktime_get()` function returns a value in the range
+        // INVARIANT: The `ClockId::ktime_get()` function returns a value in the range
         // from 0 to `KTIME_MAX`.
         Self {
             inner: C::ktime_get(),
@@ -239,7 +239,7 @@ pub(crate) unsafe fn from_ktime(ktime: bindings::ktime_t) -> Self {
     }
 }
 
-impl<C: ClockSource> ops::Sub for Instant<C> {
+impl<C: ClockId> ops::Sub for Instant<C> {
     type Output = Delta;
 
     // By the type invariant, it never overflows.
@@ -251,7 +251,7 @@ fn sub(self, other: Instant<C>) -> Delta {
     }
 }
 
-impl<T: ClockSource> ops::Add<Delta> for Instant<T> {
+impl<T: ClockId> ops::Add<Delta> for Instant<T> {
     type Output = Self;
 
     #[inline]
@@ -271,7 +271,7 @@ fn add(self, rhs: Delta) -> Self::Output {
     }
 }
 
-impl<T: ClockSource> ops::Sub<Delta> for Instant<T> {
+impl<T: ClockId> ops::Sub<Delta> for Instant<T> {
     type Output = Self;
 
     #[inline]
diff --git a/rust/kernel/time/hrtimer.rs b/rust/kernel/time/hrtimer.rs
index 2d7f1131a813..87aafbee0ce9 100644
--- a/rust/kernel/time/hrtimer.rs
+++ b/rust/kernel/time/hrtimer.rs
@@ -403,14 +403,14 @@
 //!
 //! [`Arc`]: kernel::sync::Arc
 
-use super::{ClockSource, Delta, Instant};
+use super::{ClockId, Delta, Instant};
 use crate::{prelude::*, types::Opaque};
 use core::{marker::PhantomData, ptr::NonNull};
 use pin_init::PinInit;
 
 /// A type-alias to refer to the [`Instant<C>`] for a given `T` from [`HrTimer<T>`].
 ///
-/// Where `C` is the [`ClockSource`] of the [`HrTimer`].
+/// Where `C` is the [`ClockId`] of the [`HrTimer`].
 pub type HrTimerInstant<T> = Instant<<<T as HasHrTimer<T>>::TimerMode as HrTimerMode>::Clock>;
 
 /// A timer backed by a C `struct hrtimer`.
@@ -855,7 +855,7 @@ pub trait HrTimerExpires {
     fn as_nanos(&self) -> i64;
 }
 
-impl<C: ClockSource> HrTimerExpires for Instant<C> {
+impl<C: ClockId> HrTimerExpires for Instant<C> {
     #[inline]
     fn as_nanos(&self) -> i64 {
         Instant::<C>::as_nanos(self)
@@ -870,22 +870,22 @@ fn as_nanos(&self) -> i64 {
 }
 
 mod private {
-    use crate::time::ClockSource;
+    use crate::time::ClockId;
 
     pub trait Sealed {}
 
-    impl<C: ClockSource> Sealed for super::AbsoluteMode<C> {}
-    impl<C: ClockSource> Sealed for super::RelativeMode<C> {}
-    impl<C: ClockSource> Sealed for super::AbsolutePinnedMode<C> {}
-    impl<C: ClockSource> Sealed for super::RelativePinnedMode<C> {}
-    impl<C: ClockSource> Sealed for super::AbsoluteSoftMode<C> {}
-    impl<C: ClockSource> Sealed for super::RelativeSoftMode<C> {}
-    impl<C: ClockSource> Sealed for super::AbsolutePinnedSoftMode<C> {}
-    impl<C: ClockSource> Sealed for super::RelativePinnedSoftMode<C> {}
-    impl<C: ClockSource> Sealed for super::AbsoluteHardMode<C> {}
-    impl<C: ClockSource> Sealed for super::RelativeHardMode<C> {}
-    impl<C: ClockSource> Sealed for super::AbsolutePinnedHardMode<C> {}
-    impl<C: ClockSource> Sealed for super::RelativePinnedHardMode<C> {}
+    impl<C: ClockId> Sealed for super::AbsoluteMode<C> {}
+    impl<C: ClockId> Sealed for super::RelativeMode<C> {}
+    impl<C: ClockId> Sealed for super::AbsolutePinnedMode<C> {}
+    impl<C: ClockId> Sealed for super::RelativePinnedMode<C> {}
+    impl<C: ClockId> Sealed for super::AbsoluteSoftMode<C> {}
+    impl<C: ClockId> Sealed for super::RelativeSoftMode<C> {}
+    impl<C: ClockId> Sealed for super::AbsolutePinnedSoftMode<C> {}
+    impl<C: ClockId> Sealed for super::RelativePinnedSoftMode<C> {}
+    impl<C: ClockId> Sealed for super::AbsoluteHardMode<C> {}
+    impl<C: ClockId> Sealed for super::RelativeHardMode<C> {}
+    impl<C: ClockId> Sealed for super::AbsolutePinnedHardMode<C> {}
+    impl<C: ClockId> Sealed for super::RelativePinnedHardMode<C> {}
 }
 
 /// Operational mode of [`HrTimer`].
@@ -894,16 +894,16 @@ pub trait HrTimerMode: private::Sealed {
     const C_MODE: bindings::hrtimer_mode;
 
     /// Type representing the clock source.
-    type Clock: ClockSource;
+    type Clock: ClockId;
 
     /// Type representing the expiration specification (absolute or relative time).
     type Expires: HrTimerExpires;
 }
 
 /// Timer that expires at a fixed point in time.
-pub struct AbsoluteMode<C: ClockSource>(PhantomData<C>);
+pub struct AbsoluteMode<C: ClockId>(PhantomData<C>);
 
-impl<C: ClockSource> HrTimerMode for AbsoluteMode<C> {
+impl<C: ClockId> HrTimerMode for AbsoluteMode<C> {
     const C_MODE: bindings::hrtimer_mode = bindings::hrtimer_mode_HRTIMER_MODE_ABS;
 
     type Clock = C;
@@ -911,9 +911,9 @@ impl<C: ClockSource> HrTimerMode for AbsoluteMode<C> {
 }
 
 /// Timer that expires after a delay from now.
-pub struct RelativeMode<C: ClockSource>(PhantomData<C>);
+pub struct RelativeMode<C: ClockId>(PhantomData<C>);
 
-impl<C: ClockSource> HrTimerMode for RelativeMode<C> {
+impl<C: ClockId> HrTimerMode for RelativeMode<C> {
     const C_MODE: bindings::hrtimer_mode = bindings::hrtimer_mode_HRTIMER_MODE_REL;
 
     type Clock = C;
@@ -921,8 +921,8 @@ impl<C: ClockSource> HrTimerMode for RelativeMode<C> {
 }
 
 /// Timer with absolute expiration time, pinned to its current CPU.
-pub struct AbsolutePinnedMode<C: ClockSource>(PhantomData<C>);
-impl<C: ClockSource> HrTimerMode for AbsolutePinnedMode<C> {
+pub struct AbsolutePinnedMode<C: ClockId>(PhantomData<C>);
+impl<C: ClockId> HrTimerMode for AbsolutePinnedMode<C> {
     const C_MODE: bindings::hrtimer_mode = bindings::hrtimer_mode_HRTIMER_MODE_ABS_PINNED;
 
     type Clock = C;
@@ -930,8 +930,8 @@ impl<C: ClockSource> HrTimerMode for AbsolutePinnedMode<C> {
 }
 
 /// Timer with relative expiration time, pinned to its current CPU.
-pub struct RelativePinnedMode<C: ClockSource>(PhantomData<C>);
-impl<C: ClockSource> HrTimerMode for RelativePinnedMode<C> {
+pub struct RelativePinnedMode<C: ClockId>(PhantomData<C>);
+impl<C: ClockId> HrTimerMode for RelativePinnedMode<C> {
     const C_MODE: bindings::hrtimer_mode = bindings::hrtimer_mode_HRTIMER_MODE_REL_PINNED;
 
     type Clock = C;
@@ -939,8 +939,8 @@ impl<C: ClockSource> HrTimerMode for RelativePinnedMode<C> {
 }
 
 /// Timer with absolute expiration, handled in soft irq context.
-pub struct AbsoluteSoftMode<C: ClockSource>(PhantomData<C>);
-impl<C: ClockSource> HrTimerMode for AbsoluteSoftMode<C> {
+pub struct AbsoluteSoftMode<C: ClockId>(PhantomData<C>);
+impl<C: ClockId> HrTimerMode for AbsoluteSoftMode<C> {
     const C_MODE: bindings::hrtimer_mode = bindings::hrtimer_mode_HRTIMER_MODE_ABS_SOFT;
 
     type Clock = C;
@@ -948,8 +948,8 @@ impl<C: ClockSource> HrTimerMode for AbsoluteSoftMode<C> {
 }
 
 /// Timer with relative expiration, handled in soft irq context.
-pub struct RelativeSoftMode<C: ClockSource>(PhantomData<C>);
-impl<C: ClockSource> HrTimerMode for RelativeSoftMode<C> {
+pub struct RelativeSoftMode<C: ClockId>(PhantomData<C>);
+impl<C: ClockId> HrTimerMode for RelativeSoftMode<C> {
     const C_MODE: bindings::hrtimer_mode = bindings::hrtimer_mode_HRTIMER_MODE_REL_SOFT;
 
     type Clock = C;
@@ -957,8 +957,8 @@ impl<C: ClockSource> HrTimerMode for RelativeSoftMode<C> {
 }
 
 /// Timer with absolute expiration, pinned to CPU and handled in soft irq context.
-pub struct AbsolutePinnedSoftMode<C: ClockSource>(PhantomData<C>);
-impl<C: ClockSource> HrTimerMode for AbsolutePinnedSoftMode<C> {
+pub struct AbsolutePinnedSoftMode<C: ClockId>(PhantomData<C>);
+impl<C: ClockId> HrTimerMode for AbsolutePinnedSoftMode<C> {
     const C_MODE: bindings::hrtimer_mode = bindings::hrtimer_mode_HRTIMER_MODE_ABS_PINNED_SOFT;
 
     type Clock = C;
@@ -966,8 +966,8 @@ impl<C: ClockSource> HrTimerMode for AbsolutePinnedSoftMode<C> {
 }
 
 /// Timer with absolute expiration, pinned to CPU and handled in soft irq context.
-pub struct RelativePinnedSoftMode<C: ClockSource>(PhantomData<C>);
-impl<C: ClockSource> HrTimerMode for RelativePinnedSoftMode<C> {
+pub struct RelativePinnedSoftMode<C: ClockId>(PhantomData<C>);
+impl<C: ClockId> HrTimerMode for RelativePinnedSoftMode<C> {
     const C_MODE: bindings::hrtimer_mode = bindings::hrtimer_mode_HRTIMER_MODE_REL_PINNED_SOFT;
 
     type Clock = C;
@@ -975,8 +975,8 @@ impl<C: ClockSource> HrTimerMode for RelativePinnedSoftMode<C> {
 }
 
 /// Timer with absolute expiration, handled in hard irq context.
-pub struct AbsoluteHardMode<C: ClockSource>(PhantomData<C>);
-impl<C: ClockSource> HrTimerMode for AbsoluteHardMode<C> {
+pub struct AbsoluteHardMode<C: ClockId>(PhantomData<C>);
+impl<C: ClockId> HrTimerMode for AbsoluteHardMode<C> {
     const C_MODE: bindings::hrtimer_mode = bindings::hrtimer_mode_HRTIMER_MODE_ABS_HARD;
 
     type Clock = C;
@@ -984,8 +984,8 @@ impl<C: ClockSource> HrTimerMode for AbsoluteHardMode<C> {
 }
 
 /// Timer with relative expiration, handled in hard irq context.
-pub struct RelativeHardMode<C: ClockSource>(PhantomData<C>);
-impl<C: ClockSource> HrTimerMode for RelativeHardMode<C> {
+pub struct RelativeHardMode<C: ClockId>(PhantomData<C>);
+impl<C: ClockId> HrTimerMode for RelativeHardMode<C> {
     const C_MODE: bindings::hrtimer_mode = bindings::hrtimer_mode_HRTIMER_MODE_REL_HARD;
 
     type Clock = C;
@@ -993,8 +993,8 @@ impl<C: ClockSource> HrTimerMode for RelativeHardMode<C> {
 }
 
 /// Timer with absolute expiration, pinned to CPU and handled in hard irq context.
-pub struct AbsolutePinnedHardMode<C: ClockSource>(PhantomData<C>);
-impl<C: ClockSource> HrTimerMode for AbsolutePinnedHardMode<C> {
+pub struct AbsolutePinnedHardMode<C: ClockId>(PhantomData<C>);
+impl<C: ClockId> HrTimerMode for AbsolutePinnedHardMode<C> {
     const C_MODE: bindings::hrtimer_mode = bindings::hrtimer_mode_HRTIMER_MODE_ABS_PINNED_HARD;
 
     type Clock = C;
@@ -1002,8 +1002,8 @@ impl<C: ClockSource> HrTimerMode for AbsolutePinnedHardMode<C> {
 }
 
 /// Timer with relative expiration, pinned to CPU and handled in hard irq context.
-pub struct RelativePinnedHardMode<C: ClockSource>(PhantomData<C>);
-impl<C: ClockSource> HrTimerMode for RelativePinnedHardMode<C> {
+pub struct RelativePinnedHardMode<C: ClockId>(PhantomData<C>);
+impl<C: ClockId> HrTimerMode for RelativePinnedHardMode<C> {
     const C_MODE: bindings::hrtimer_mode = bindings::hrtimer_mode_HRTIMER_MODE_REL_PINNED_HARD;
 
     type Clock = C;

base-commit: 7059bdf4f04a3e14f4fafb3ac35fdca913e3e21a
-- 
2.43.0