[PATCH v3 2/2] drm/tests: Split drm_test_dp_mst_sideband_msg_req_decode into parameterized tests

[Maíra Canal]

The drm_test_dp_mst_sideband_msg_req_decode repeats the same test
structure with different parameters. This could be better represented
by parameterized tests, provided by KUnit.

In addition to the parameterization of the tests, the test case for the
client ID was changed: instead of using get_random_bytes to generate
the client ID, the client ID is now hardcoded in the test case. This
doesn't affect the assertively of the tests, as this test case only compare
the data going in with the data going out and it doesn't transform the data
itself in any way.

So, convert drm_test_dp_mst_sideband_msg_req_decode into parameterized
tests and make the tests' allocations and prints completely managed by KUnit.

Signed-off-by: Maíra Canal <mcanal@xxxxxxxxxx>
---
v1 -> v2: https://lore.kernel.org/dri-devel/20220925222719.345424-1-mcanal@xxxxxxxxxx/T/#m056610a23a63109484afeafefb5846178c4d36b2
- Mention on the commit message the change on the test case for the client ID (Michał Winiarski).

v2 -> v3: https://lore.kernel.org/dri-devel/20220927221206.55930-1-mcanal@xxxxxxxxxx/T/#m2dc961da2d4921566cd0f9a8ed9d2d33a1cf4416
- Mention on the commit message that the "random" usage is not incompatible with parameterized tests (Michał Winiarski).
---
 .../gpu/drm/tests/drm_dp_mst_helper_test.c    | 370 ++++++++++++------
 1 file changed, 243 insertions(+), 127 deletions(-)

diff --git a/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c b/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c
index 12f41881db6b..545beea33e8c 100644
--- a/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c
+++ b/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c
@@ -5,12 +5,8 @@
  * Copyright (c) 2022 Maíra Canal <mairacanal@xxxxxxxxxx>
  */
 
-#define PREFIX_STR "[drm_dp_mst_helper]"
-
 #include <kunit/test.h>
 
-#include <linux/random.h>
-
 #include <drm/display/drm_dp_mst_helper.h>
 #include <drm/drm_print.h>
 
@@ -72,6 +68,217 @@ static void dp_mst_calc_pbn_mode_desc(const struct drm_dp_mst_calc_pbn_mode_test
 KUNIT_ARRAY_PARAM(drm_dp_mst_calc_pbn_mode, drm_dp_mst_calc_pbn_mode_cases,
 		  dp_mst_calc_pbn_mode_desc);
 
+static u8 data[] = { 0xff, 0x00, 0xdd };
+
+struct drm_dp_mst_sideband_msg_req_test {
+	const char *desc;
+	const struct drm_dp_sideband_msg_req_body in;
+};
+
+static const struct drm_dp_mst_sideband_msg_req_test drm_dp_mst_sideband_msg_req_cases[] = {
+	{
+		.desc = "DP_ENUM_PATH_RESOURCES with port number",
+		.in = {
+			.req_type = DP_ENUM_PATH_RESOURCES,
+			.u.port_num.port_number = 5,
+		},
+	},
+	{
+		.desc = "DP_POWER_UP_PHY with port number",
+		.in = {
+			.req_type = DP_POWER_UP_PHY,
+			.u.port_num.port_number = 5,
+		},
+	},
+	{
+		.desc = "DP_POWER_DOWN_PHY with port number",
+		.in = {
+			.req_type = DP_POWER_DOWN_PHY,
+			.u.port_num.port_number = 5,
+		},
+	},
+	{
+		.desc = "DP_ALLOCATE_PAYLOAD with SDP stream sinks",
+		.in = {
+			.req_type = DP_ALLOCATE_PAYLOAD,
+			.u.allocate_payload.number_sdp_streams = 3,
+			.u.allocate_payload.sdp_stream_sink = { 1, 2, 3 },
+		},
+	},
+	{
+		.desc = "DP_ALLOCATE_PAYLOAD with port number",
+		.in = {
+			.req_type = DP_ALLOCATE_PAYLOAD,
+			.u.allocate_payload.port_number = 0xf,
+		},
+	},
+	{
+		.desc = "DP_ALLOCATE_PAYLOAD with VCPI",
+		.in = {
+			.req_type = DP_ALLOCATE_PAYLOAD,
+			.u.allocate_payload.vcpi = 0x7f,
+		},
+	},
+	{
+		.desc = "DP_ALLOCATE_PAYLOAD with PBN",
+		.in = {
+			.req_type = DP_ALLOCATE_PAYLOAD,
+			.u.allocate_payload.pbn = U16_MAX,
+		},
+	},
+	{
+		.desc = "DP_QUERY_PAYLOAD with port number",
+		.in = {
+			.req_type = DP_QUERY_PAYLOAD,
+			.u.query_payload.port_number = 0xf,
+		},
+	},
+	{
+		.desc = "DP_QUERY_PAYLOAD with VCPI",
+		.in = {
+			.req_type = DP_QUERY_PAYLOAD,
+			.u.query_payload.vcpi = 0x7f,
+		},
+	},
+	{
+		.desc = "DP_REMOTE_DPCD_READ with port number",
+		.in = {
+			.req_type = DP_REMOTE_DPCD_READ,
+			.u.dpcd_read.port_number = 0xf,
+		},
+	},
+	{
+		.desc = "DP_REMOTE_DPCD_READ with DPCD address",
+		.in = {
+			.req_type = DP_REMOTE_DPCD_READ,
+			.u.dpcd_read.dpcd_address = 0xfedcb,
+		},
+	},
+	{
+		.desc = "DP_REMOTE_DPCD_READ with max number of bytes",
+		.in = {
+			.req_type = DP_REMOTE_DPCD_READ,
+			.u.dpcd_read.num_bytes = U8_MAX,
+		},
+	},
+	{
+		.desc = "DP_REMOTE_DPCD_WRITE with port number",
+		.in = {
+			.req_type = DP_REMOTE_DPCD_WRITE,
+			.u.dpcd_write.port_number = 0xf,
+		},
+	},
+	{
+		.desc = "DP_REMOTE_DPCD_WRITE with DPCD address",
+		.in = {
+			.req_type = DP_REMOTE_DPCD_WRITE,
+			.u.dpcd_write.dpcd_address = 0xfedcb,
+		},
+	},
+	{
+		.desc = "DP_REMOTE_DPCD_WRITE with data array",
+		.in = {
+			.req_type = DP_REMOTE_DPCD_WRITE,
+			.u.dpcd_write.num_bytes = ARRAY_SIZE(data),
+			.u.dpcd_write.bytes = data,
+		},
+	},
+	{
+		.desc = "DP_REMOTE_I2C_READ with port number",
+		.in = {
+			.req_type = DP_REMOTE_I2C_READ,
+			.u.i2c_read.port_number = 0xf,
+		},
+	},
+	{
+		.desc = "DP_REMOTE_I2C_READ with I2C device ID",
+		.in = {
+			.req_type = DP_REMOTE_I2C_READ,
+			.u.i2c_read.read_i2c_device_id = 0x7f,
+		},
+	},
+	{
+		.desc = "DP_REMOTE_I2C_READ with transactions array",
+		.in = {
+			.req_type = DP_REMOTE_I2C_READ,
+			.u.i2c_read.num_transactions = 3,
+			.u.i2c_read.num_bytes_read = ARRAY_SIZE(data) * 3,
+			.u.i2c_read.transactions = {
+				{ .bytes = data, .num_bytes = ARRAY_SIZE(data), .i2c_dev_id = 0x7f,
+				  .i2c_transaction_delay = 0xf, },
+				{ .bytes = data, .num_bytes = ARRAY_SIZE(data), .i2c_dev_id = 0x7e,
+				  .i2c_transaction_delay = 0xe, },
+				{ .bytes = data, .num_bytes = ARRAY_SIZE(data), .i2c_dev_id = 0x7d,
+				  .i2c_transaction_delay = 0xd, },
+			},
+		},
+	},
+	{
+		.desc = "DP_REMOTE_I2C_WRITE with port number",
+		.in = {
+			.req_type = DP_REMOTE_I2C_WRITE,
+			.u.i2c_write.port_number = 0xf,
+		},
+	},
+	{
+		.desc = "DP_REMOTE_I2C_WRITE with I2C device ID",
+		.in = {
+			.req_type = DP_REMOTE_I2C_WRITE,
+			.u.i2c_write.write_i2c_device_id = 0x7f,
+		},
+	},
+	{
+		.desc = "DP_REMOTE_I2C_WRITE with data array",
+		.in = {
+			.req_type = DP_REMOTE_I2C_WRITE,
+			.u.i2c_write.num_bytes = ARRAY_SIZE(data),
+			.u.i2c_write.bytes = data,
+		},
+	},
+	{
+		.desc = "DP_QUERY_STREAM_ENC_STATUS with stream ID",
+		.in = {
+			.req_type = DP_QUERY_STREAM_ENC_STATUS,
+			.u.enc_status.stream_id = 1,
+		},
+	},
+	{
+		.desc = "DP_QUERY_STREAM_ENC_STATUS with client ID",
+		.in = {
+			.req_type = DP_QUERY_STREAM_ENC_STATUS,
+			.u.enc_status.client_id = { 0x4f, 0x7f, 0xb4, 0x00, 0x8c, 0x0d, 0x67 },
+		},
+	},
+	{
+		.desc = "DP_QUERY_STREAM_ENC_STATUS with stream event",
+		.in = {
+			.req_type = DP_QUERY_STREAM_ENC_STATUS,
+			.u.enc_status.stream_event = 3,
+		},
+	},
+	{
+		.desc = "DP_QUERY_STREAM_ENC_STATUS with valid stream event",
+		.in = {
+			.req_type = DP_QUERY_STREAM_ENC_STATUS,
+			.u.enc_status.valid_stream_event = 0,
+		},
+	},
+	{
+		.desc = "DP_QUERY_STREAM_ENC_STATUS with stream behavior",
+		.in = {
+			.req_type = DP_QUERY_STREAM_ENC_STATUS,
+			.u.enc_status.stream_behavior = 3,
+		},
+	},
+	{
+		.desc = "DP_QUERY_STREAM_ENC_STATUS with a valid stream behavior",
+		.in = {
+			.req_type = DP_QUERY_STREAM_ENC_STATUS,
+			.u.enc_status.valid_stream_behavior = 1,
+		}
+	},
+};
+
 static bool
 sideband_msg_req_equal(const struct drm_dp_sideband_msg_req_body *in,
 		       const struct drm_dp_sideband_msg_req_body *out)
@@ -147,41 +354,41 @@ sideband_msg_req_equal(const struct drm_dp_sideband_msg_req_body *in,
 	return true;
 }
 
-static bool
-sideband_msg_req_encode_decode(struct drm_dp_sideband_msg_req_body *in)
+static void drm_test_dp_mst_msg_printf(struct drm_printer *p, struct va_format *vaf)
+{
+	struct kunit *test = p->arg;
+
+	kunit_err(test, "%pV", vaf);
+}
+
+static void drm_test_dp_mst_sideband_msg_req_decode(struct kunit *test)
 {
+	const struct drm_dp_mst_sideband_msg_req_test *params = test->param_value;
+	const struct drm_dp_sideband_msg_req_body *in = &params->in;
 	struct drm_dp_sideband_msg_req_body *out;
-	struct drm_printer p = drm_err_printer(PREFIX_STR);
 	struct drm_dp_sideband_msg_tx *txmsg;
-	int i, ret;
-	bool result = true;
+	struct drm_printer p = {
+		.printfn = drm_test_dp_mst_msg_printf,
+		.arg = test
+	};
+	int i;
 
-	out = kzalloc(sizeof(*out), GFP_KERNEL);
-	if (!out)
-		return false;
+	out = kunit_kzalloc(test, sizeof(*out), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, out);
 
-	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
-	if (!txmsg) {
-		kfree(out);
-		return false;
-	}
+	txmsg = kunit_kzalloc(test, sizeof(*txmsg), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, txmsg);
 
 	drm_dp_encode_sideband_req(in, txmsg);
-	ret = drm_dp_decode_sideband_req(txmsg, out);
-	if (ret < 0) {
-		drm_printf(&p, "Failed to decode sideband request: %d\n",
-			   ret);
-		result = false;
-		goto out;
-	}
+	KUNIT_EXPECT_GE_MSG(test, drm_dp_decode_sideband_req(txmsg, out), 0,
+			    "Failed to decode sideband request");
 
 	if (!sideband_msg_req_equal(in, out)) {
-		drm_printf(&p, "Encode/decode failed, expected:\n");
+		KUNIT_FAIL(test, "Encode/decode failed");
+		kunit_err(test, "Expected:");
 		drm_dp_dump_sideband_msg_req_body(in, 1, &p);
-		drm_printf(&p, "Got:\n");
+		kunit_err(test, "Got:");
 		drm_dp_dump_sideband_msg_req_body(out, 1, &p);
-		result = false;
-		goto out;
 	}
 
 	switch (in->req_type) {
@@ -196,112 +403,21 @@ sideband_msg_req_encode_decode(struct drm_dp_sideband_msg_req_body *in)
 		kfree(out->u.i2c_write.bytes);
 		break;
 	}
-
-	/* Clear everything but the req_type for the input */
-	memset(&in->u, 0, sizeof(in->u));
-
-out:
-	kfree(out);
-	kfree(txmsg);
-	return result;
 }
 
-static void drm_test_dp_mst_sideband_msg_req_decode(struct kunit *test)
+static void
+drm_dp_mst_sideband_msg_req_desc(const struct drm_dp_mst_sideband_msg_req_test *t, char *desc)
 {
-	struct drm_dp_sideband_msg_req_body in = { 0 };
-	u8 data[] = { 0xff, 0x0, 0xdd };
-	int i;
-
-	in.req_type = DP_ENUM_PATH_RESOURCES;
-	in.u.port_num.port_number = 5;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-
-	in.req_type = DP_POWER_UP_PHY;
-	in.u.port_num.port_number = 5;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-
-	in.req_type = DP_POWER_DOWN_PHY;
-	in.u.port_num.port_number = 5;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-
-	in.req_type = DP_ALLOCATE_PAYLOAD;
-	in.u.allocate_payload.number_sdp_streams = 3;
-	for (i = 0; i < in.u.allocate_payload.number_sdp_streams; i++)
-		in.u.allocate_payload.sdp_stream_sink[i] = i + 1;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.allocate_payload.port_number = 0xf;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.allocate_payload.vcpi = 0x7f;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.allocate_payload.pbn = U16_MAX;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-
-	in.req_type = DP_QUERY_PAYLOAD;
-	in.u.query_payload.port_number = 0xf;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.query_payload.vcpi = 0x7f;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-
-	in.req_type = DP_REMOTE_DPCD_READ;
-	in.u.dpcd_read.port_number = 0xf;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.dpcd_read.dpcd_address = 0xfedcb;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.dpcd_read.num_bytes = U8_MAX;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-
-	in.req_type = DP_REMOTE_DPCD_WRITE;
-	in.u.dpcd_write.port_number = 0xf;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.dpcd_write.dpcd_address = 0xfedcb;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.dpcd_write.num_bytes = ARRAY_SIZE(data);
-	in.u.dpcd_write.bytes = data;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-
-	in.req_type = DP_REMOTE_I2C_READ;
-	in.u.i2c_read.port_number = 0xf;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.i2c_read.read_i2c_device_id = 0x7f;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.i2c_read.num_transactions = 3;
-	in.u.i2c_read.num_bytes_read = ARRAY_SIZE(data) * 3;
-	for (i = 0; i < in.u.i2c_read.num_transactions; i++) {
-		in.u.i2c_read.transactions[i].bytes = data;
-		in.u.i2c_read.transactions[i].num_bytes = ARRAY_SIZE(data);
-		in.u.i2c_read.transactions[i].i2c_dev_id = 0x7f & ~i;
-		in.u.i2c_read.transactions[i].i2c_transaction_delay = 0xf & ~i;
-	}
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-
-	in.req_type = DP_REMOTE_I2C_WRITE;
-	in.u.i2c_write.port_number = 0xf;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.i2c_write.write_i2c_device_id = 0x7f;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.i2c_write.num_bytes = ARRAY_SIZE(data);
-	in.u.i2c_write.bytes = data;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-
-	in.req_type = DP_QUERY_STREAM_ENC_STATUS;
-	in.u.enc_status.stream_id = 1;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	get_random_bytes(in.u.enc_status.client_id,
-			 sizeof(in.u.enc_status.client_id));
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.enc_status.stream_event = 3;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.enc_status.valid_stream_event = 0;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.enc_status.stream_behavior = 3;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
-	in.u.enc_status.valid_stream_behavior = 1;
-	KUNIT_EXPECT_TRUE(test, sideband_msg_req_encode_decode(&in));
+	strcpy(desc, t->desc);
 }
 
+KUNIT_ARRAY_PARAM(drm_dp_mst_sideband_msg_req, drm_dp_mst_sideband_msg_req_cases,
+		  drm_dp_mst_sideband_msg_req_desc);
+
 static struct kunit_case drm_dp_mst_helper_tests[] = {
 	KUNIT_CASE_PARAM(drm_test_dp_mst_calc_pbn_mode, drm_dp_mst_calc_pbn_mode_gen_params),
-	KUNIT_CASE(drm_test_dp_mst_sideband_msg_req_decode),
+	KUNIT_CASE_PARAM(drm_test_dp_mst_sideband_msg_req_decode,
+			 drm_dp_mst_sideband_msg_req_gen_params),
 	{ }
 };
 
-- 
2.37.3