[PATCH v1 1/7] rust: sync: completion: add wait_for_completion_timeout()

[Joel Fernandes]

Add a timeout variant of wait_for_completion() that wraps the C
function wait_for_completion_timeout(). Returns true if the task
completed before the timeout, else false.

The timeout is specified in jiffies. This is needed by drivers
that perform interrupt self-tests during probe, where an indefinite
wait would hang the system if the interrupt path is broken.

Signed-off-by: Joel Fernandes <joelagnelf@xxxxxxxxxx>
---
 rust/kernel/sync/completion.rs | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/rust/kernel/sync/completion.rs b/rust/kernel/sync/completion.rs
index c50012a940a3..a2f46862365e 100644
--- a/rust/kernel/sync/completion.rs
+++ b/rust/kernel/sync/completion.rs
@@ -6,7 +6,12 @@
 //!
 //! C header: [`include/linux/completion.h`](srctree/include/linux/completion.h)
 
-use crate::{bindings, prelude::*, types::Opaque};
+use crate::{
+    bindings,
+    prelude::*,
+    time::Jiffies,
+    types::Opaque, //
+};
 
 /// Synchronization primitive to signal when a certain task has been completed.
 ///
@@ -109,4 +114,15 @@ pub fn wait_for_completion(&self) {
         // SAFETY: `self.as_raw()` is a pointer to a valid `struct completion`.
         unsafe { bindings::wait_for_completion(self.as_raw()) };
     }
+
+    /// Wait for completion of a task with a timeout.
+    ///
+    /// This method waits for the completion of a task; it is not interruptible but has a timeout.
+    /// Returns `true` if the task completed before the timeout, `false` if the timeout elapsed.
+    ///
+    /// The timeout is specified in jiffies. See also [`Completion::complete_all`].
+    pub fn wait_for_completion_timeout(&self, timeout: Jiffies) -> bool {
+        // SAFETY: `self.as_raw()` is a pointer to a valid `struct completion`.
+        unsafe { bindings::wait_for_completion_timeout(self.as_raw(), timeout) != 0 }
+    }
 }

base-commit: 610e892bdb57043c7769982c2bff0260b6007b75
-- 
2.34.1