[PATCH v13 06/17] irq: Add KUnit test for refcounted interrupt enable/disable

Lyude Paul
2025-10-13T15:54:18Z

While making changes to the refcounted interrupt patch series, at some
point on my local branch I broke something and ended up writing some kunit
tests for testing refcounted interrupts as a result. So, let's include
these tests now that we have refcounted interrupts.

Signed-off-by: Lyude Paul <lyude@redhat.com>

---
V13:
* Add missing MODULE_DESCRIPTION/MODULE_LICENSE lines
* Switch from kunit_test_suites(…) to kunit_test_suite(…)

kernel/irq/Makefile | 1 +
kernel/irq/refcount_interrupt_test.c | 109 +++++++++++++++++++++++++++
2 files changed, 110 insertions(+)
create mode 100644 kernel/irq/refcount_interrupt_test.c

diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile
index 6ab3a40556670..7b5bb5510b110 100644
--- a/kernel/irq/Makefile
+++ b/kernel/irq/Makefile
@@ -20,3 +20,4 @@ obj-$(CONFIG_SMP) += affinity.o
obj-$(CONFIG_GENERIC_IRQ_DEBUGFS) += debugfs.o
obj-$(CONFIG_GENERIC_IRQ_MATRIX_ALLOCATOR) += matrix.o
obj-$(CONFIG_IRQ_KUNIT_TEST) += irq_test.o
+obj-$(CONFIG_KUNIT) += refcount_interrupt_test.o
diff --git a/kernel/irq/refcount_interrupt_test.c b/kernel/irq/refcount_interrupt_test.c
new file mode 100644
index 0000000000000..d10375743142f
--- /dev/null
+++ b/kernel/irq/refcount_interrupt_test.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for refcounted interrupt enable/disables.
+ */
+
+#include <kunit/test.h>
+#include <linux/spinlock.h>
+
+#define TEST_IRQ_ON() KUNIT_EXPECT_FALSE(test, irqs_disabled())
+#define TEST_IRQ_OFF() KUNIT_EXPECT_TRUE(test, irqs_disabled())
+
+/* ===== Test cases ===== */
+static void test_single_irq_change(struct kunit *test)
+{
+ local_interrupt_disable();
+ TEST_IRQ_OFF();
+ local_interrupt_enable();
+}
+
+static void test_nested_irq_change(struct kunit *test)
+{
+ local_interrupt_disable();
+ TEST_IRQ_OFF();
+ local_interrupt_disable();
+ TEST_IRQ_OFF();
+ local_interrupt_disable();
+ TEST_IRQ_OFF();
+
+ local_interrupt_enable();
+ TEST_IRQ_OFF();
+ local_interrupt_enable();
+ TEST_IRQ_OFF();
+ local_interrupt_enable();
+ TEST_IRQ_ON();
+}
+
+static void test_multiple_irq_change(struct kunit *test)
+{
+ local_interrupt_disable();
+ TEST_IRQ_OFF();
+ local_interrupt_disable();
+ TEST_IRQ_OFF();
+
+ local_interrupt_enable();
+ TEST_IRQ_OFF();
+ local_interrupt_enable();
+ TEST_IRQ_ON();
+
+ local_interrupt_disable();
+ TEST_IRQ_OFF();
+ local_interrupt_enable();
+ TEST_IRQ_ON();
+}
+
+static void test_irq_save(struct kunit *test)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ TEST_IRQ_OFF();
+ local_interrupt_disable();
+ TEST_IRQ_OFF();
+ local_interrupt_enable();
+ TEST_IRQ_OFF();
+ local_irq_restore(flags);
+ TEST_IRQ_ON();
+
+ local_interrupt_disable();
+ TEST_IRQ_OFF();
+ local_irq_save(flags);
+ TEST_IRQ_OFF();
+ local_irq_restore(flags);
+ TEST_IRQ_OFF();
+ local_interrupt_enable();
+ TEST_IRQ_ON();
+}
+
+static struct kunit_case test_cases[] = {
+ KUNIT_CASE(test_single_irq_change),
+ KUNIT_CASE(test_nested_irq_change),
+ KUNIT_CASE(test_multiple_irq_change),
+ KUNIT_CASE(test_irq_save),
+ {},
+};
+
+/* (init and exit are the same */
+static int test_init(struct kunit *test)
+{
+ TEST_IRQ_ON();
+
+ return 0;
+}
+
+static void test_exit(struct kunit *test)
+{
+ TEST_IRQ_ON();
+}
+
+static struct kunit_suite refcount_interrupt_test_suite = {
+ .name = "refcount_interrupt",
+ .test_cases = test_cases,
+ .init = test_init,
+ .exit = test_exit,
+};
+
+kunit_test_suite(refcount_interrupt_test_suite);
+MODULE_AUTHOR("Lyude Paul <lyude@redhat.com>");
+MODULE_DESCRIPTION("Refcounted interrupt unit test suite");
+MODULE_LICENSE("GPL");
--
2.51.0