genirq/test: Factor out fake-virq setup

A few things need to be repeated in tests. Factor out the creation of fake
interrupts.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/all/20250822190140.2154646-3-briannorris@chromium.org

Author: computersforpeace

kernel/irq/irq_test.c

@@ -41,22 +41,35 @@ static struct irq_chip fake_irq_chip = {
 	.flags          = IRQCHIP_SKIP_SET_WAKE,
 };
 
-static void irq_disable_depth_test(struct kunit *test)
+static int irq_test_setup_fake_irq(struct kunit *test, struct irq_affinity_desc *affd)
 {
 	struct irq_desc *desc;
-	int virq, ret;
+	int virq;
 
-	virq = irq_domain_alloc_descs(-1, 1, 0, NUMA_NO_NODE, NULL);
+	virq = irq_domain_alloc_descs(-1, 1, 0, NUMA_NO_NODE, affd);
 	KUNIT_ASSERT_GE(test, virq, 0);
 
-	irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
+	irq_set_chip_and_handler(virq, &fake_irq_chip, handle_simple_irq);
 
 	desc = irq_to_desc(virq);
 	KUNIT_ASSERT_PTR_NE(test, desc, NULL);
 
 	/* On some architectures, IRQs are NOREQUEST | NOPROBE by default. */
 	irq_settings_clr_norequest(desc);
 
+	return virq;
+}
+
+static void irq_disable_depth_test(struct kunit *test)
+{
+	struct irq_desc *desc;
+	int virq, ret;
+
+	virq = irq_test_setup_fake_irq(test, NULL);
+
+	desc = irq_to_desc(virq);
+	KUNIT_ASSERT_PTR_NE(test, desc, NULL);
+
 	ret = request_irq(virq, noop_handler, 0, "test_irq", NULL);
 	KUNIT_EXPECT_EQ(test, ret, 0);
 
@@ -76,17 +89,11 @@ static void irq_free_disabled_test(struct kunit *test)
 	struct irq_desc *desc;
 	int virq, ret;
 
-	virq = irq_domain_alloc_descs(-1, 1, 0, NUMA_NO_NODE, NULL);
-	KUNIT_ASSERT_GE(test, virq, 0);
-
-	irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
+	virq = irq_test_setup_fake_irq(test, NULL);
 
 	desc = irq_to_desc(virq);
 	KUNIT_ASSERT_PTR_NE(test, desc, NULL);
 
-	/* On some architectures, IRQs are NOREQUEST | NOPROBE by default. */
-	irq_settings_clr_norequest(desc);
-
 	ret = request_irq(virq, noop_handler, 0, "test_irq", NULL);
 	KUNIT_EXPECT_EQ(test, ret, 0);
 
@@ -118,17 +125,11 @@ static void irq_shutdown_depth_test(struct kunit *test)
 	if (!IS_ENABLED(CONFIG_SMP))
 		kunit_skip(test, "requires CONFIG_SMP for managed shutdown");
 
-	virq = irq_domain_alloc_descs(-1, 1, 0, NUMA_NO_NODE, &affinity);
-	KUNIT_ASSERT_GE(test, virq, 0);
-
-	irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
+	virq = irq_test_setup_fake_irq(test, &affinity);
 
 	desc = irq_to_desc(virq);
 	KUNIT_ASSERT_PTR_NE(test, desc, NULL);
 
-	/* On some architectures, IRQs are NOREQUEST | NOPROBE by default. */
-	irq_settings_clr_norequest(desc);
-
 	data = irq_desc_get_irq_data(desc);
 	KUNIT_ASSERT_PTR_NE(test, data, NULL);
 
@@ -181,17 +182,11 @@ static void irq_cpuhotplug_test(struct kunit *test)
 
 	cpumask_copy(&affinity.mask, cpumask_of(1));
 
-	virq = irq_domain_alloc_descs(-1, 1, 0, NUMA_NO_NODE, &affinity);
-	KUNIT_ASSERT_GE(test, virq, 0);
-
-	irq_set_chip_and_handler(virq, &fake_irq_chip, handle_simple_irq);
+	virq = irq_test_setup_fake_irq(test, &affinity);
 
 	desc = irq_to_desc(virq);
 	KUNIT_ASSERT_PTR_NE(test, desc, NULL);
 
-	/* On some architectures, IRQs are NOREQUEST | NOPROBE by default. */
-	irq_settings_clr_norequest(desc);
-
 	data = irq_desc_get_irq_data(desc);
 	KUNIT_ASSERT_PTR_NE(test, data, NULL);