[tip: locking/core] irq: Add KUnit test for refcounted interrupt enable/disable

["tip-bot2 for Lyude Paul" <tip-bot2@linutronix.de>]

The following commit has been merged into the locking/core branch of tip:

Commit-ID:     07a88e2bcd5b5bd7881b2e12b6aad1897a7ee1de
Gitweb:        https://git.kernel.org/tip/07a88e2bcd5b5bd7881b2e12b6aad1897a7ee1de
Author:        Lyude Paul <lyude@redhat.com>
AuthorDate:    Tue, 04 Aug 2026 09:14:28 -07:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Mon, 10 Aug 2026 10:50:18 +02:00

irq: Add KUnit test for refcounted interrupt enable/disable

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>
Signed-off-by: Boqun Feng <boqun@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260804161447.84806-7-boqun@kernel.org
---
 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 86a2e5a..44c4d6f 100644
--- a/kernel/irq/Makefile
+++ b/kernel/irq/Makefile
@@ -16,3 +16,4 @@ 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 0000000..ca904db
--- /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/interrupt_rc.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");