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authorTvrtko Ursulin <tursulin@ursulin.net>2025-02-05 09:29:14 +0000
committerTvrtko Ursulin <tursulin@ursulin.net>2025-02-05 09:29:14 +0000
commitc771600c6af14749609b49565ffb4cac2959710d (patch)
treee9be426f1b32598527127fd0fa1b265a7cc83044 /rust/kernel/tracepoint.rs
parent4a82ceb04ad4bbb9cc20925abccb70938313e555 (diff)
parent2014c95afecee3e76ca4a56956a936e23283f05b (diff)
Merge drm/drm-next into drm-intel-gt-next
We need 4ba4f1afb6a9 ("perf: Generic hotplug support for a PMU with a scope") in order to land a i915 PMU simplification and a fix. That landed in 6.12 and we are stuck at 6.9 so lets bump things forward. Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>
Diffstat (limited to 'rust/kernel/tracepoint.rs')
-rw-r--r--rust/kernel/tracepoint.rs49
1 files changed, 49 insertions, 0 deletions
diff --git a/rust/kernel/tracepoint.rs b/rust/kernel/tracepoint.rs
new file mode 100644
index 000000000000..c6e80aa99e8e
--- /dev/null
+++ b/rust/kernel/tracepoint.rs
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2024 Google LLC.
+
+//! Logic for tracepoints.
+
+/// Declare the Rust entry point for a tracepoint.
+///
+/// This macro generates an unsafe function that calls into C, and its safety requirements will be
+/// whatever the relevant C code requires. To document these safety requirements, you may add
+/// doc-comments when invoking the macro.
+#[macro_export]
+macro_rules! declare_trace {
+ ($($(#[$attr:meta])* $pub:vis unsafe fn $name:ident($($argname:ident : $argtyp:ty),* $(,)?);)*) => {$(
+ $( #[$attr] )*
+ #[inline(always)]
+ $pub unsafe fn $name($($argname : $argtyp),*) {
+ #[cfg(CONFIG_TRACEPOINTS)]
+ {
+ // SAFETY: It's always okay to query the static key for a tracepoint.
+ let should_trace = unsafe {
+ $crate::macros::paste! {
+ $crate::jump_label::static_branch_unlikely!(
+ $crate::bindings::[< __tracepoint_ $name >],
+ $crate::bindings::tracepoint,
+ key
+ )
+ }
+ };
+
+ if should_trace {
+ $crate::macros::paste! {
+ // SAFETY: The caller guarantees that it is okay to call this tracepoint.
+ unsafe { $crate::bindings::[< rust_do_trace_ $name >]($($argname),*) };
+ }
+ }
+ }
+
+ #[cfg(not(CONFIG_TRACEPOINTS))]
+ {
+ // If tracepoints are disabled, insert a trivial use of each argument
+ // to avoid unused argument warnings.
+ $( let _unused = $argname; )*
+ }
+ }
+ )*}
+}
+
+pub use declare_trace;