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Diffstat (limited to 'kernel/src/drivers/riscv_timer.rs')
-rw-r--r--kernel/src/drivers/riscv_timer.rs43
1 files changed, 0 insertions, 43 deletions
diff --git a/kernel/src/drivers/riscv_timer.rs b/kernel/src/drivers/riscv_timer.rs
deleted file mode 100644
index a702f7b..0000000
--- a/kernel/src/drivers/riscv_timer.rs
+++ /dev/null
@@ -1,43 +0,0 @@
-use core::{arch::asm, ops::Add, time::Duration};
-
-/// The number of `Instant` "ticks" in a second. Initialized by the early-boot DeviceTree parser.
-pub static mut TIMEBASE_FREQUENCY: u32 = 0;
-
-/// A moment in time.
-#[derive(Clone, Copy, Debug, Eq, Ord, PartialEq, PartialOrd)]
-pub struct Instant(u64);
-
-impl Instant {
- /// Returns the current time as an `Instant`.
- pub fn now() -> Instant {
- let out;
- // SAFETY: We require the Sstc extension, enable it before jumping to Rust, and never
- // disable it.
- unsafe {
- asm!("rdtime {out}", out = out(reg) out, options(nomem, nostack));
- }
- Instant(out)
- }
-}
-
-impl Add<Duration> for Instant {
- type Output = Instant;
-
- #[allow(clippy::suspicious_arithmetic_impl)]
- fn add(self, duration: Duration) -> Instant {
- // SAFETY: TIMEBASE_FREQUENCY is never concurrently written to.
- let ticks_per_second = unsafe { TIMEBASE_FREQUENCY };
- let ticks = duration.as_nanos().wrapping_mul(ticks_per_second as u128) / 1_000_000_000;
- Instant(self.0.wrapping_add(ticks as u64))
- }
-}
-
-/// Sets the timer interrupt to fire at the given instant. Note that this sets a global value,
-/// rather than interacting with the scheduler in any way.
-pub fn set_timer(instant: Instant) {
- // SAFETY: We require the Sstc extension, enable it before jumping to Rust, and never
- // disable it.
- unsafe {
- asm!("csrw stimecmp, {instant}", instant = in(reg) instant.0, options(nomem, nostack));
- }
-}