From: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
---
rust/kernel/block/mq/request.rs | 67 ++++++++++++++++++++++++++++++++-
1 file changed, 66 insertions(+), 1 deletion(-)
diff --git a/rust/kernel/block/mq/request.rs b/rust/kernel/block/mq/request.rs
index cccffde45981..8b7f08f894be 100644
--- a/rust/kernel/block/mq/request.rs
+++ b/rust/kernel/block/mq/request.rs
@@ -4,13 +4,16 @@
//!
//! C header: [`include/linux/blk-mq.h`](srctree/include/linux/blk-mq.h)
+use kernel::hrtimer::RawTimer;
+
use crate::{
bindings,
block::mq::Operations,
error::{Error, Result},
+ hrtimer::{HasTimer, TimerCallback},
types::{ARef, AlwaysRefCounted, Opaque},
};
-use core::{ffi::c_void, marker::PhantomData, ops::Deref};
+use core::{ffi::c_void, marker::PhantomData, ops::Deref, ptr::NonNull};
use crate::block::bio::Bio;
use crate::block::bio::BioIterator;
@@ -175,6 +178,68 @@ fn deref(&self) -> &Self::Target {
}
}
+impl<T> RawTimer for RequestDataRef<T>
+where
+ T: Operations,
+ T::RequestData: HasTimer<T::RequestData>,
+ T::RequestData: Sync,
+{
+ fn schedule(self, expires: u64) {
+ let self_ptr = self.deref() as *const T::RequestData;
+ core::mem::forget(self);
+
+ // SAFETY: `self_ptr` is a valid pointer to a `T::RequestData`
+ let timer_ptr = unsafe { T::RequestData::raw_get_timer(self_ptr) };
+
+ // `Timer` is `repr(transparent)`
+ let c_timer_ptr = timer_ptr.cast::<bindings::hrtimer>();
+
+ // Schedule the timer - if it is already scheduled it is removed and
+ // inserted
+
+ // SAFETY: c_timer_ptr points to a valid hrtimer instance that was
+ // initialized by `hrtimer_init`
+ unsafe {
+ bindings::hrtimer_start_range_ns(
+ c_timer_ptr as *mut _,
+ expires as i64,
+ 0,
+ bindings::hrtimer_mode_HRTIMER_MODE_REL,
+ );
+ }
+ }
+}
+
+impl<T> kernel::hrtimer::RawTimerCallback for RequestDataRef<T>
+where
+ T: Operations,
+ T: Sync,
+ T::RequestData: HasTimer<T::RequestData>,
+ T::RequestData: TimerCallback<Receiver = Self>,
+{
+ unsafe extern "C" fn run(ptr: *mut bindings::hrtimer) -> bindings::hrtimer_restart {
+ // `Timer` is `repr(transparent)`
+ let timer_ptr = ptr.cast::<kernel::hrtimer::Timer<T::RequestData>>();
+
+ // SAFETY: By C API contract `ptr` is the pointer we passed when
+ // enqueing the timer, so it is a `Timer<T::RequestData>` embedded in a `T::RequestData`
+ let receiver_ptr = unsafe { T::RequestData::timer_container_of(timer_ptr) };
+
+ // SAFETY: The pointer was returned by `T::timer_container_of` so it
+ // points to a valid `T::RequestData`
+ let request_ptr = unsafe { bindings::blk_mq_rq_from_pdu(receiver_ptr.cast::<c_void>()) };
+
+ // SAFETY: We own a refcount that we leaked during `RawTimer::schedule()`
+ let dref = RequestDataRef::new(unsafe {
+ ARef::from_raw(NonNull::new_unchecked(request_ptr.cast::<Request<T>>()))
+ });
+
+ T::RequestData::run(dref);
+
+ bindings::hrtimer_restart_HRTIMER_NORESTART
+ }
+}
+
// SAFETY: All instances of `Request<T>` are reference counted. This
// implementation of `AlwaysRefCounted` ensure that increments to the ref count
// keeps the object alive in memory at least until a matching reference count
--
2.44.0
