[PATCH v2 14/15] platform/chrome: cros_ec_proto: return 0 on getting version mask success

[Tzung-Bi Shih <tzungbi@kernel.org>]

cros_ec_get_host_command_version_mask() used to return value from
send_command() which is number of bytes for input payload on success
(i.e. sizeof(struct ec_response_get_cmd_versions)).

However, the callers don't need to know how many bytes are available.

- Fix cros_ec_get_host_command_version_mask() to return 0 on success;
  negative integers on error.

- Remove the unneeded `ver_mask` initialization as the callers should
  take it only if cros_ec_get_host_command_version_mask() returns 0.

- Add a Kunit test: `ver_mask` has some garbage bytes from previous
  EC_CMD_GET_NEXT_EVENT but there is no host sleep to make sure the
  caller checks the return values correctly.

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
---
Changes from v1:
- Return 0 on success; otherwise, negative intergers.

 drivers/platform/chrome/cros_ec_proto.c      |  37 ++-
 drivers/platform/chrome/cros_ec_proto_test.c | 286 +++++++++++++++++++
 2 files changed, 308 insertions(+), 15 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index ee15a73eee38..9d96ed16244f 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -428,13 +428,12 @@ static int cros_ec_get_proto_info_legacy(struct cros_ec_device *ec_dev)
  * the caller has ec_dev->lock mutex or the caller knows there is
  * no other command in progress.
  */
-static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
-	u16 cmd, u32 *mask)
+static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev, u16 cmd, u32 *mask)
 {
 	struct ec_params_get_cmd_versions *pver;
 	struct ec_response_get_cmd_versions *rver;
 	struct cros_ec_command *msg;
-	int ret;
+	int ret, mapped;
 
 	msg = kmalloc(sizeof(*msg) + max(sizeof(*rver), sizeof(*pver)),
 		      GFP_KERNEL);
@@ -450,13 +449,25 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
 	pver->cmd = cmd;
 
 	ret = send_command(ec_dev, msg);
-	if (ret > 0) {
-		rver = (struct ec_response_get_cmd_versions *)msg->data;
-		*mask = rver->version_mask;
+	if (ret < 0)
+		goto exit;
+
+	mapped = cros_ec_map_error(msg->result);
+	if (mapped) {
+		ret = mapped;
+		goto exit;
 	}
 
-	kfree(msg);
+	if (ret == 0) {
+		ret = -EPROTO;
+		goto exit;
+	}
 
+	rver = (struct ec_response_get_cmd_versions *)msg->data;
+	*mask = rver->version_mask;
+	ret = 0;
+exit:
+	kfree(msg);
 	return ret;
 }
 
@@ -469,7 +480,7 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
  */
 int cros_ec_query_all(struct cros_ec_device *ec_dev)
 {
-	u32 ver_mask = 0;
+	u32 ver_mask;
 	int ret;
 	u8 *din, *dout;
 
@@ -503,9 +514,7 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
 	ec_dev->dout = dout;
 
 	/* Probe if MKBP event is supported */
-	ret = cros_ec_get_host_command_version_mask(ec_dev,
-						    EC_CMD_GET_NEXT_EVENT,
-						    &ver_mask);
+	ret = cros_ec_get_host_command_version_mask(ec_dev, EC_CMD_GET_NEXT_EVENT, &ver_mask);
 	if (ret < 0 || ver_mask == 0) {
 		ec_dev->mkbp_event_supported = 0;
 	} else {
@@ -515,10 +524,8 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
 	}
 
 	/* Probe if host sleep v1 is supported for S0ix failure detection. */
-	ret = cros_ec_get_host_command_version_mask(ec_dev,
-						    EC_CMD_HOST_SLEEP_EVENT,
-						    &ver_mask);
-	ec_dev->host_sleep_v1 = (ret >= 0 && (ver_mask & EC_VER_MASK(1)));
+	ret = cros_ec_get_host_command_version_mask(ec_dev, EC_CMD_HOST_SLEEP_EVENT, &ver_mask);
+	ec_dev->host_sleep_v1 = (ret == 0 && (ver_mask & EC_VER_MASK(1)));
 
 	/* Get host event wake mask. */
 	ret = cros_ec_get_host_event_wake_mask(ec_dev, &ec_dev->host_event_wake_mask);
diff --git a/drivers/platform/chrome/cros_ec_proto_test.c b/drivers/platform/chrome/cros_ec_proto_test.c
index 27b81a5a9880..af69410f2978 100644
--- a/drivers/platform/chrome/cros_ec_proto_test.c
+++ b/drivers/platform/chrome/cros_ec_proto_test.c
@@ -890,6 +890,182 @@ static void cros_ec_proto_test_query_all_no_mkbp(struct kunit *test)
 	}
 }
 
+static void cros_ec_proto_test_query_all_no_mkbp_return_error(struct kunit *test)
+{
+	struct cros_ec_proto_test_priv *priv = test->priv;
+	struct cros_ec_device *ec_dev = &priv->ec_dev;
+	struct ec_xfer_mock *mock;
+	int ret;
+
+	/* Set some garbage bytes. */
+	ec_dev->mkbp_event_supported = 0xbf;
+
+	/* For cros_ec_get_proto_info() without passthru. */
+	{
+		struct ec_response_get_protocol_info *data;
+
+		mock = cros_kunit_ec_xfer_mock_add(test, sizeof(*data));
+		KUNIT_ASSERT_PTR_NE(test, mock, NULL);
+
+		/*
+		 * Although it doesn't check the value, provides valid sizes so that
+		 * cros_ec_query_all() allocates din and dout correctly.
+		 */
+		data = (struct ec_response_get_protocol_info *)mock->o_data;
+		data->max_request_packet_size = 0xbe;
+		data->max_response_packet_size = 0xef;
+	}
+
+	/* For cros_ec_get_proto_info() with passthru. */
+	{
+		mock = cros_kunit_ec_xfer_mock_addx(test, 0, EC_RES_INVALID_COMMAND, 0);
+		KUNIT_ASSERT_PTR_NE(test, mock, NULL);
+	}
+
+	/* For cros_ec_get_host_command_version_mask() for MKBP. */
+	{
+		mock = cros_kunit_ec_xfer_mock_addx(test, 0, EC_RES_INVALID_COMMAND, 0);
+		KUNIT_ASSERT_PTR_NE(test, mock, NULL);
+	}
+
+	cros_ec_proto_test_query_all_pretest(test);
+	ret = cros_ec_query_all(ec_dev);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	/* For cros_ec_get_proto_info() without passthru. */
+	{
+		mock = cros_kunit_ec_xfer_mock_next();
+		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
+
+		KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
+		KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_GET_PROTOCOL_INFO);
+		KUNIT_EXPECT_EQ(test, mock->msg.insize,
+				sizeof(struct ec_response_get_protocol_info));
+		KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0);
+	}
+
+	/* For cros_ec_get_proto_info() with passthru. */
+	{
+		mock = cros_kunit_ec_xfer_mock_next();
+		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
+
+		KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
+		KUNIT_EXPECT_EQ(test, mock->msg.command,
+				EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX) |
+				EC_CMD_GET_PROTOCOL_INFO);
+		KUNIT_EXPECT_EQ(test, mock->msg.insize,
+				sizeof(struct ec_response_get_protocol_info));
+		KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0);
+	}
+
+	/* For cros_ec_get_host_command_version_mask() for MKBP. */
+	{
+		struct ec_params_get_cmd_versions *data;
+
+		mock = cros_kunit_ec_xfer_mock_next();
+		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
+
+		KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
+		KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_GET_CMD_VERSIONS);
+		KUNIT_EXPECT_EQ(test, mock->msg.insize,
+				sizeof(struct ec_response_get_cmd_versions));
+		KUNIT_EXPECT_EQ(test, mock->msg.outsize, sizeof(*data));
+
+		data = (struct ec_params_get_cmd_versions *)mock->i_data;
+		KUNIT_EXPECT_EQ(test, data->cmd, EC_CMD_GET_NEXT_EVENT);
+
+		KUNIT_EXPECT_EQ(test, ec_dev->mkbp_event_supported, 0);
+	}
+}
+
+static void cros_ec_proto_test_query_all_no_mkbp_return0(struct kunit *test)
+{
+	struct cros_ec_proto_test_priv *priv = test->priv;
+	struct cros_ec_device *ec_dev = &priv->ec_dev;
+	struct ec_xfer_mock *mock;
+	int ret;
+
+	/* Set some garbage bytes. */
+	ec_dev->mkbp_event_supported = 0xbf;
+
+	/* For cros_ec_get_proto_info() without passthru. */
+	{
+		struct ec_response_get_protocol_info *data;
+
+		mock = cros_kunit_ec_xfer_mock_add(test, sizeof(*data));
+		KUNIT_ASSERT_PTR_NE(test, mock, NULL);
+
+		/*
+		 * Although it doesn't check the value, provides valid sizes so that
+		 * cros_ec_query_all() allocates din and dout correctly.
+		 */
+		data = (struct ec_response_get_protocol_info *)mock->o_data;
+		data->max_request_packet_size = 0xbe;
+		data->max_response_packet_size = 0xef;
+	}
+
+	/* For cros_ec_get_proto_info() with passthru. */
+	{
+		mock = cros_kunit_ec_xfer_mock_addx(test, 0, EC_RES_INVALID_COMMAND, 0);
+		KUNIT_ASSERT_PTR_NE(test, mock, NULL);
+	}
+
+	/* For cros_ec_get_host_command_version_mask() for MKBP. */
+	{
+		mock = cros_kunit_ec_xfer_mock_add(test, 0);
+		KUNIT_ASSERT_PTR_NE(test, mock, NULL);
+	}
+
+	cros_ec_proto_test_query_all_pretest(test);
+	ret = cros_ec_query_all(ec_dev);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	/* For cros_ec_get_proto_info() without passthru. */
+	{
+		mock = cros_kunit_ec_xfer_mock_next();
+		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
+
+		KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
+		KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_GET_PROTOCOL_INFO);
+		KUNIT_EXPECT_EQ(test, mock->msg.insize,
+				sizeof(struct ec_response_get_protocol_info));
+		KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0);
+	}
+
+	/* For cros_ec_get_proto_info() with passthru. */
+	{
+		mock = cros_kunit_ec_xfer_mock_next();
+		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
+
+		KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
+		KUNIT_EXPECT_EQ(test, mock->msg.command,
+				EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX) |
+				EC_CMD_GET_PROTOCOL_INFO);
+		KUNIT_EXPECT_EQ(test, mock->msg.insize,
+				sizeof(struct ec_response_get_protocol_info));
+		KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0);
+	}
+
+	/* For cros_ec_get_host_command_version_mask() for MKBP. */
+	{
+		struct ec_params_get_cmd_versions *data;
+
+		mock = cros_kunit_ec_xfer_mock_next();
+		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
+
+		KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
+		KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_GET_CMD_VERSIONS);
+		KUNIT_EXPECT_EQ(test, mock->msg.insize,
+				sizeof(struct ec_response_get_cmd_versions));
+		KUNIT_EXPECT_EQ(test, mock->msg.outsize, sizeof(*data));
+
+		data = (struct ec_params_get_cmd_versions *)mock->i_data;
+		KUNIT_EXPECT_EQ(test, data->cmd, EC_CMD_GET_NEXT_EVENT);
+
+		KUNIT_EXPECT_EQ(test, ec_dev->mkbp_event_supported, 0);
+	}
+}
+
 static void cros_ec_proto_test_query_all_no_host_sleep(struct kunit *test)
 {
 	struct cros_ec_proto_test_priv *priv = test->priv;
@@ -996,6 +1172,113 @@ static void cros_ec_proto_test_query_all_no_host_sleep(struct kunit *test)
 	}
 }
 
+static void cros_ec_proto_test_query_all_no_host_sleep_return0(struct kunit *test)
+{
+	struct cros_ec_proto_test_priv *priv = test->priv;
+	struct cros_ec_device *ec_dev = &priv->ec_dev;
+	struct ec_xfer_mock *mock;
+	int ret;
+
+	/* Set some garbage bytes. */
+	ec_dev->host_sleep_v1 = true;
+
+	/* For cros_ec_get_proto_info() without passthru. */
+	{
+		struct ec_response_get_protocol_info *data;
+
+		mock = cros_kunit_ec_xfer_mock_add(test, sizeof(*data));
+		KUNIT_ASSERT_PTR_NE(test, mock, NULL);
+
+		/*
+		 * Although it doesn't check the value, provides valid sizes so that
+		 * cros_ec_query_all() allocates din and dout correctly.
+		 */
+		data = (struct ec_response_get_protocol_info *)mock->o_data;
+		data->max_request_packet_size = 0xbe;
+		data->max_response_packet_size = 0xef;
+	}
+
+	/* For cros_ec_get_proto_info() with passthru. */
+	{
+		mock = cros_kunit_ec_xfer_mock_addx(test, 0, EC_RES_INVALID_COMMAND, 0);
+		KUNIT_ASSERT_PTR_NE(test, mock, NULL);
+	}
+
+	/* For cros_ec_get_host_command_version_mask() for MKBP. */
+	{
+		struct ec_response_get_cmd_versions *data;
+
+		mock = cros_kunit_ec_xfer_mock_add(test, sizeof(*data));
+		KUNIT_ASSERT_PTR_NE(test, mock, NULL);
+
+		/* In order to pollute next cros_ec_get_host_command_version_mask(). */
+		data = (struct ec_response_get_cmd_versions *)mock->o_data;
+		data->version_mask = 0xbeef;
+	}
+
+	/* For cros_ec_get_host_command_version_mask() for host sleep v1. */
+	{
+		mock = cros_kunit_ec_xfer_mock_add(test, 0);
+		KUNIT_ASSERT_PTR_NE(test, mock, NULL);
+	}
+
+	cros_ec_proto_test_query_all_pretest(test);
+	ret = cros_ec_query_all(ec_dev);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	/* For cros_ec_get_proto_info() without passthru. */
+	{
+		mock = cros_kunit_ec_xfer_mock_next();
+		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
+
+		KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
+		KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_GET_PROTOCOL_INFO);
+		KUNIT_EXPECT_EQ(test, mock->msg.insize,
+				sizeof(struct ec_response_get_protocol_info));
+		KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0);
+	}
+
+	/* For cros_ec_get_proto_info() with passthru. */
+	{
+		mock = cros_kunit_ec_xfer_mock_next();
+		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
+
+		KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
+		KUNIT_EXPECT_EQ(test, mock->msg.command,
+				EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX) |
+				EC_CMD_GET_PROTOCOL_INFO);
+		KUNIT_EXPECT_EQ(test, mock->msg.insize,
+				sizeof(struct ec_response_get_protocol_info));
+		KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0);
+	}
+
+	/* For cros_ec_get_host_command_version_mask() for MKBP. */
+	{
+		mock = cros_kunit_ec_xfer_mock_next();
+		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
+
+		KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
+		KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_GET_CMD_VERSIONS);
+		KUNIT_EXPECT_EQ(test, mock->msg.insize,
+				sizeof(struct ec_response_get_cmd_versions));
+		KUNIT_EXPECT_EQ(test, mock->msg.outsize, sizeof(struct ec_params_get_cmd_versions));
+	}
+
+	/* For cros_ec_get_host_command_version_mask() for host sleep v1. */
+	{
+		mock = cros_kunit_ec_xfer_mock_next();
+		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
+
+		KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
+		KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_GET_CMD_VERSIONS);
+		KUNIT_EXPECT_EQ(test, mock->msg.insize,
+				sizeof(struct ec_response_get_cmd_versions));
+		KUNIT_EXPECT_EQ(test, mock->msg.outsize, sizeof(struct ec_params_get_cmd_versions));
+
+		KUNIT_EXPECT_FALSE(test, ec_dev->host_sleep_v1);
+	}
+}
+
 static void cros_ec_proto_test_query_all_default_wake_mask_return_error(struct kunit *test)
 {
 	struct cros_ec_proto_test_priv *priv = test->priv;
@@ -1183,7 +1466,10 @@ static struct kunit_case cros_ec_proto_test_cases[] = {
 	KUNIT_CASE(cros_ec_proto_test_query_all_legacy_data_error),
 	KUNIT_CASE(cros_ec_proto_test_query_all_legacy_return0),
 	KUNIT_CASE(cros_ec_proto_test_query_all_no_mkbp),
+	KUNIT_CASE(cros_ec_proto_test_query_all_no_mkbp_return_error),
+	KUNIT_CASE(cros_ec_proto_test_query_all_no_mkbp_return0),
 	KUNIT_CASE(cros_ec_proto_test_query_all_no_host_sleep),
+	KUNIT_CASE(cros_ec_proto_test_query_all_no_host_sleep_return0),
 	KUNIT_CASE(cros_ec_proto_test_query_all_default_wake_mask_return_error),
 	{}
 };
-- 
2.36.1.255.ge46751e96f-goog