Add a short exercise for Rust's per-CPU variable API, modelled after
lib/percpu_test.c
Signed-off-by: Mitchell Levy <levymitchell0@xxxxxxxxx>
---
lib/Kconfig.debug | 9 +++++++
lib/Makefile | 1 +
lib/percpu_test_rust.rs | 65 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 75 insertions(+)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index f3d723705879..75a91f1766ce 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2404,6 +2404,15 @@ config PERCPU_TEST
If unsure, say N.
+config PERCPU_TEST_RUST
+ tristate "Rust per cpu operations test"
+ depends on m && DEBUG_KERNEL && RUST
+ help
+ Enable this option to build a test module which validates Rust per-cpu
+ operations.
+
+ If unsure, say N.
+
config ATOMIC64_SELFTEST
tristate "Perform an atomic64_t self-test"
help
diff --git a/lib/Makefile b/lib/Makefile
index a8155c972f02..0ea8d414763c 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -301,6 +301,7 @@ obj-$(CONFIG_RBTREE_TEST) += rbtree_test.o
obj-$(CONFIG_INTERVAL_TREE_TEST) += interval_tree_test.o
obj-$(CONFIG_PERCPU_TEST) += percpu_test.o
+obj-$(CONFIG_PERCPU_TEST_RUST) += percpu_test_rust.o
obj-$(CONFIG_ASN1) += asn1_decoder.o
obj-$(CONFIG_ASN1_ENCODER) += asn1_encoder.o
diff --git a/lib/percpu_test_rust.rs b/lib/percpu_test_rust.rs
new file mode 100644
index 000000000000..60df44332d7a
--- /dev/null
+++ b/lib/percpu_test_rust.rs
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0
+//! A simple self test for the rust per-CPU API.
+use kernel::{
+ define_per_cpu, percpu::cpu_guard::*, percpu::*, pr_info, prelude::*, unsafe_get_per_cpu_ref,
+};
+
+module! {
+ type: PerCpuTestModule,
+ name: "percpu_test_rust",
+ author: "Mitchell Levy",
+ description: "Test code to exercise the Rust Per CPU variable API",
+ license: "GPL v2",
+}
+
+struct PerCpuTestModule;
+
+define_per_cpu!(PERCPU: i64 = 0);
+define_per_cpu!(UPERCPU: u64 = 0);
+
+impl kernel::Module for PerCpuTestModule {
+ fn init(_module: &'static ThisModule) -> Result<Self, Error> {
+ pr_info!("rust percpu test start\n");
+
+ let mut native: i64 = 0;
+ let mut pcpu: PerCpuRef<i64> = unsafe { unsafe_get_per_cpu_ref!(PERCPU, CpuGuard::new()) };
+
+ native += -1;
+ *pcpu += -1;
+ assert!(native == *pcpu && native == -1);
+
+ native += 1;
+ *pcpu += 1;
+ assert!(native == *pcpu && native == 0);
+
+ let mut unative: u64 = 0;
+ let mut upcpu: PerCpuRef<u64> =
+ unsafe { unsafe_get_per_cpu_ref!(UPERCPU, CpuGuard::new()) };
+
+ unative += 1;
+ *upcpu += 1;
+ assert!(unative == *upcpu && unative == 1);
+
+ unative = unative.wrapping_add((-1i64) as u64);
+ *upcpu = upcpu.wrapping_add((-1i64) as u64);
+ assert!(unative == *upcpu && unative == 0);
+
+ unative = unative.wrapping_add((-1i64) as u64);
+ *upcpu = upcpu.wrapping_add((-1i64) as u64);
+ assert!(unative == *upcpu && unative == (-1i64) as u64);
+
+ unative = 0;
+ *upcpu = 0;
+
+ unative = unative.wrapping_sub(1);
+ *upcpu = upcpu.wrapping_sub(1);
+ assert!(unative == *upcpu && unative == (-1i64) as u64);
+ assert!(unative == *upcpu && unative == u64::MAX);
+
+ pr_info!("rust percpu test done\n");
+
+ // Return Err to unload the module
+ Result::Err(EINVAL)
+ }
+}
+
--
2.34.1
