firewire: core: add test to detect irm-is-1394-1995-only quirk in config ROM parser

Some Sony DV cameras have a quirk where their IRM functionality does not
comply with IEEE 1394a:2000. This quirk was supported by commit
10389536742c ("firewire: core: check for 1394a compliant IRM, fix
inaccessibility of Sony camcorder") and refactored by commit 5a43dc9f4ee0
("firewire: core: detect device quirk when reading configuration ROM").

Add a KUnit test to check detection of the quirk. The configuration ROM
content is retrieved from the following discussion:
https://github.com/systemd/systemd/issues/25029.

Link: https://lore.kernel.org/r/20260901134534.2386577-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

2 files changed, 155 insertions, 0 deletions

diff --git a/drivers/firewire/config-rom-parser-test.c b/drivers/firewire/config-rom-parser-test.c
index 632f24e68692..131c7aa3b224 100644
--- a/drivers/firewire/config-rom-parser-test.c
+++ b/drivers/firewire/config-rom-parser-test.c
@@ -7,13 +7,164 @@
 // This file can not be built independently since it is intentionally included in core-device.c.
 
 #include <kunit/test.h>
+#include <kunit/static_stub.h>
+#include <kunit/device.h>
+
+static const u32 sony_dcr_trv310k_config_rom[] = {
+	0x0404e552,
+	0x31333934,
+	0xe0648100,
+	0x00008500,
+	0x005eb597,
+	0x0007cdd0,
+	0x03000085,
+	0x8100000d,
+	0x17000002,
+	0x81000010,
+	0x0c0083c0,
+	0xd8000002,
+	0xd1000003,
+	0x0001ce96,
+	0xd1000001,
+	0x0004bbee,
+	0x1200a02d,
+	0x13010001,
+	0x17000002,
+	0x81000006,
+	0x00046dc8,
+	0x00000000,
+	0x00000000,
+	0x43616e6f,
+	0x6e000000,
+	0x000621ee,
+	0x00000000,
+	0x00000000,
+	0x4d563569,
+	0x204d4300,
+	0x00000000,
+	0x00000000,
+};
+
+static const struct parser_test_case {
+	const char *name;
+	const u32 *quadlets;
+	size_t quadlet_length;
+	int phy_speed_in_self_id;
+	int expected_speed;
+	int expected_quirk;
+	unsigned int expected_max_rec;
+	bool expected_cmc;
+	bool expected_irmc;
+} parser_test_cases[] = {
+	{
+		.name = "detect_irm_is_1394_1995_only_quirk",
+		.quadlets = sony_dcr_trv310k_config_rom,
+		.quadlet_length = ARRAY_SIZE(sony_dcr_trv310k_config_rom),
+		.phy_speed_in_self_id = SCODE_100,
+		.expected_speed = SCODE_100,
+		.expected_quirk = FW_DEVICE_QUIRK_IRM_IS_1394_1995_ONLY,
+		.expected_max_rec = 8,
+		.expected_cmc = true,
+		.expected_irmc = true,
+	},
+};
+
+// Define parser_test_gen_params.
+KUNIT_ARRAY_PARAM_DESC(parser_test, parser_test_cases, name);
+
+static int stub_run_regular_transaction(struct fw_card *card, int tcode, int destination_id,
+					int generation, int speed, unsigned long long offset,
+					void *payload, size_t length)
+{
+	struct kunit *test = kunit_get_current_test();
+	const struct parser_test_case *param = test->param_value;
+
+	KUNIT_ASSERT_GE(test, offset, CSR_REGISTER_BASE | CSR_CONFIG_ROM);
+	KUNIT_ASSERT_LT(test, offset, CSR_REGISTER_BASE | CSR_CONFIG_ROM_END);
+	KUNIT_ASSERT_NOT_NULL(test, payload);
+	KUNIT_ASSERT_EQ(test, length, 4);
+
+	unsigned int index = (offset - (CSR_REGISTER_BASE | CSR_CONFIG_ROM)) / sizeof(u32);
+	u32 *quadlet = payload;
+
+	KUNIT_EXPECT_LE(test, speed, param->expected_speed);
+	KUNIT_EXPECT_LT(test, index, param->quadlet_length);
+
+	*quadlet = cpu_to_be32(param->quadlets[index]);
+
+	return RCODE_COMPLETE;
+}
+
+static void test_parser_with_regular_cases(struct kunit *test)
+{
+	struct fw_device *device = test->priv;
+	const struct parser_test_case *param = test->param_value;
+
+	kunit_activate_static_stub(test, fw_run_transaction, stub_run_regular_transaction);
+
+	device->card->link_speed = SCODE_BETA;
+	device->node->max_speed = param->phy_speed_in_self_id;
+
+	KUNIT_EXPECT_EQ(test, read_config_rom(device, 0), RCODE_COMPLETE);
+
+	KUNIT_EXPECT_EQ(test, device->config_rom_length, param->quadlet_length);
+	KUNIT_EXPECT_MEMEQ(test, device->config_rom, param->quadlets, param->quadlet_length);
+
+	KUNIT_EXPECT_TRUE(test, device->quirks & param->expected_quirk);
+	KUNIT_EXPECT_EQ(test, device->max_speed, param->expected_speed);
+	KUNIT_EXPECT_EQ(test, (unsigned int)device->max_rec, param->expected_max_rec);
+	KUNIT_EXPECT_EQ(test, (bool)device->cmc, param->expected_cmc);
+	KUNIT_EXPECT_EQ(test, (bool)device->irmc, param->expected_irmc);
+
+	kunit_deactivate_static_stub(test, fw_run_transaction);
+}
+
+static const struct fw_card_driver dummy_card_driver;
+
+static int config_rom_parser_test_init(struct kunit *test)
+{
+	struct fw_device *device;
+	struct device *dev;
+
+	device = kunit_kzalloc(test, sizeof(*device), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, device);
+
+	device->node = kunit_kzalloc(test, sizeof(*device->node), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, device->node);
+	kref_init(&device->node->kref);
+
+	device->card = kunit_kzalloc(test, sizeof(*device->card), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, device->card);
+
+	dev = kunit_device_register(test, "dummy-device");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev);
+
+	fw_card_initialize(device->card, &dummy_card_driver, dev);
+
+	test->priv = device;
+
+	return 0;
+}
+
+static void config_rom_parser_test_exit(struct kunit *test)
+{
+	struct fw_device *device = test->priv;
+
+	kunit_device_unregister(test, device->card->device);
+	kunit_kfree(test, device->card);
+	kunit_kfree(test, device->node);
+	kunit_kfree(test, device);
+}
 
 static struct kunit_case config_rom_parser_test_cases[] = {
+	KUNIT_CASE_PARAM(test_parser_with_regular_cases, parser_test_gen_params),
 	{}
 };
 
 static struct kunit_suite config_rom_parser_test_suite = {
 	.name = "firewire-config-rom-parser",
+	.init = config_rom_parser_test_init,
+	.exit = config_rom_parser_test_exit,
 	.test_cases = config_rom_parser_test_cases,
 };
 kunit_test_suite(config_rom_parser_test_suite);
diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index 016070560c74..2d64ab5b0ab0 100644
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -24,6 +24,7 @@
 #include <linux/timer.h>
 #include <linux/types.h>
 #include <linux/workqueue.h>
+#include <kunit/static_stub.h>
 
 #include <asm/byteorder.h>
 
@@ -485,6 +486,9 @@ int fw_run_transaction(struct fw_card *card, int tcode, int destination_id,
 		       int generation, int speed, unsigned long long offset,
 		       void *payload, size_t length)
 {
+	KUNIT_STATIC_STUB_REDIRECT(fw_run_transaction, card, tcode, destination_id, generation,
+				   speed, offset, payload, length);
+
 	struct transaction_callback_data d;
 	struct fw_transaction t;