[PATCH net-next v3 5/5] eth fbnic: Add mailbox self test

[mike.marciniszyn@gmail.com]

From: "Mike Marciniszyn (Meta)" <mike.marciniszyn@gmail.com>

The mailbox self test ensures the interface to and from
the firmware is healthy by sending a test message and
fielding the response from the firmware.

This patch uses the new completion API [1][2] that allocates a
completion structure, binds the completion to the TEST
message, and uses a new FW parsing routine that wraps the
completion processing around the TLV parser.

Link: https://patch.msgid.link/20250516164804.741348-1-lee@trager.us [1]
Link: https://patch.msgid.link/20260115003353.4150771-6-mohsin.bashr@gmail.com [2]

Signed-off-by: Mike Marciniszyn (Meta) <mike.marciniszyn@gmail.com>
---
v2 - add enum for test return codes
v3 - no changes

 drivers/net/ethernet/meta/fbnic/fbnic.h       |  14 ++-
 .../net/ethernet/meta/fbnic/fbnic_ethtool.c   |  15 +++
 drivers/net/ethernet/meta/fbnic/fbnic_fw.c    | 100 ++++++++++++++++++
 drivers/net/ethernet/meta/fbnic/fbnic_fw.h    |  27 +++++
 3 files changed, 142 insertions(+)

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
index b0c8d1b069e2..251de64baa5a 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
@@ -129,11 +129,13 @@ static const struct fbnic_stat fbnic_gstrings_xdp_stats[] = {
 enum fbnic_self_test_results {
 	TEST_REG = 0,
 	TEST_MSIX,
+	TEST_MBX,
 };
 
 static const char fbnic_gstrings_self_test[][ETH_GSTRING_LEN] = {
 	[TEST_REG]	= "Register test (offline)",
 	[TEST_MSIX]	= "MSI-X Interrupt test (offline)",
+	[TEST_MBX]      = "FW mailbox test (on/offline)",
 };
 
 #define FBNIC_TEST_LEN ARRAY_SIZE(fbnic_gstrings_self_test)
@@ -1525,11 +1527,24 @@ static int fbnic_ethtool_msix_test(struct net_device *netdev, u64 *data)
 	return !!*data;
 }
 
+static int fbnic_ethtool_mbx_self_test(struct net_device *netdev, u64 *data)
+{
+	struct fbnic_net *fbn = netdev_priv(netdev);
+	struct fbnic_dev *fbd = fbn->fbd;
+
+	*data = fbnic_fw_mbx_self_test(fbd);
+
+	return !!*data;
+}
+
 static void fbnic_self_test(struct net_device *netdev,
 			    struct ethtool_test *eth_test, u64 *data)
 {
 	bool if_running = netif_running(netdev);
 
+	if (fbnic_ethtool_mbx_self_test(netdev, &data[TEST_MBX]))
+		eth_test->flags |= ETH_TEST_FL_FAILED;
+
 	if (!(eth_test->flags & ETH_TEST_FL_OFFLINE)) {
 		data[TEST_REG] = 0;
 		data[TEST_MSIX] = 0;
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_fw.c b/drivers/net/ethernet/meta/fbnic/fbnic_fw.c
index 1f0b6350bef4..c2bad51bdde6 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_fw.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_fw.c
@@ -378,6 +378,37 @@ fbnic_fw_get_cmpl_by_type(struct fbnic_dev *fbd, u32 msg_type)
 	return cmpl_data;
 }
 
+/**
+ * fbnic_fw_xmit_test_msg - Create and transmit a test message to FW mailbox
+ * @fbd: FBNIC device structure
+ * @cmpl: fw completion struct
+ *
+ * Return: zero on success, negative value on failure
+ *
+ * Generates a single page mailbox test message and places it in the Tx
+ * mailbox queue. Expectation is that the FW will validate that the nested
+ * value matches the external values, and then will echo them back to us.
+ *
+ * Also sets a completion slot for use in the completion wait calls when
+ * the cmpl arg is non-NULL.
+ */
+int fbnic_fw_xmit_test_msg(struct fbnic_dev *fbd,
+			   struct fbnic_fw_completion *cmpl)
+{
+	struct fbnic_tlv_msg *test_msg;
+	int err;
+
+	test_msg = fbnic_tlv_test_create(fbd);
+	if (!test_msg)
+		return -ENOMEM;
+
+	err = fbnic_mbx_map_req_w_cmpl(fbd, test_msg, cmpl);
+	if (err)
+		free_page((unsigned long)test_msg);
+
+	return err;
+}
+
 /**
  * fbnic_fw_xmit_simple_msg - Transmit a simple single TLV message w/o data
  * @fbd: FBNIC device structure
@@ -1556,7 +1587,29 @@ int fbnic_fw_xmit_send_logs(struct fbnic_dev *fbd, bool enable,
 	return err;
 }
 
+static int
+fbnic_fw_parser_test(void *opaque, struct fbnic_tlv_msg **results)
+{
+	struct fbnic_fw_completion *cmpl;
+	struct fbnic_dev *fbd = opaque;
+	int err;
+
+	/* find cmpl */
+	cmpl = fbnic_fw_get_cmpl_by_type(fbd, FBNIC_TLV_MSG_ID_TEST);
+	if (!cmpl)
+		return -ENOSPC;
+
+	err = fbnic_tlv_parser_test(opaque, results);
+
+	cmpl->result = err;
+	complete(&cmpl->done);
+	fbnic_fw_put_cmpl(cmpl);
+
+	return err;
+}
+
 static const struct fbnic_tlv_parser fbnic_fw_tlv_parser[] = {
+	FBNIC_TLV_PARSER(TEST, fbnic_tlv_test_index, fbnic_fw_parser_test),
 	FBNIC_TLV_PARSER(FW_CAP_RESP, fbnic_fw_cap_resp_index,
 			 fbnic_fw_parse_cap_resp),
 	FBNIC_TLV_PARSER(OWNERSHIP_RESP, fbnic_ownership_resp_index,
@@ -1787,6 +1840,53 @@ void fbnic_mbx_flush_tx(struct fbnic_dev *fbd)
 	} while (time_is_after_jiffies(timeout));
 }
 
+/**
+ * fbnic_fw_mbx_self_test() - verify firmware interface
+ * @fbd: device to test
+ *
+ * This function tests the interfaces to/from the firmware.
+ *
+ * Return: See enum fbnic_fw_self_test_codes
+ **/
+enum fbnic_fw_self_test_codes fbnic_fw_mbx_self_test(struct fbnic_dev *fbd)
+{
+	enum fbnic_fw_self_test_codes err;
+	struct fbnic_fw_completion *cmpl;
+
+	/* Skip test if FW interface is not present */
+	if (!fbnic_fw_present(fbd))
+		return FBNIC_TEST_FW_NO_FIRMWARE;
+
+	cmpl = fbnic_fw_alloc_cmpl(FBNIC_TLV_MSG_ID_TEST);
+	if (!cmpl)
+		return FBNIC_TEST_FW_NO_CMPL;
+
+	/* Load a test message onto the FW mailbox interface
+	 * and arm the completion.
+	 */
+	err = fbnic_fw_xmit_test_msg(fbd, cmpl);
+	if (err) {
+		err = FBNIC_TEST_FW_NO_XMIT;
+		goto exit_free;
+	}
+
+	/* Verify we received a message back */
+	if (!fbnic_mbx_wait_for_cmpl(cmpl)) {
+		err = FBNIC_TEST_FW_NO_MSG;
+		goto exit_cleanup;
+	}
+
+	/* Verify there were no parsing errors */
+	if (cmpl->result)
+		err = FBNIC_TEST_FW_PARSE;
+exit_cleanup:
+	fbnic_mbx_clear_cmpl(fbd, cmpl);
+exit_free:
+	fbnic_fw_put_cmpl(cmpl);
+
+	return err;
+}
+
 int fbnic_fw_xmit_rpc_macda_sync(struct fbnic_dev *fbd)
 {
 	struct fbnic_tlv_msg *mac_array;
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_fw.h b/drivers/net/ethernet/meta/fbnic/fbnic_fw.h
index 8f7218900562..d84723e4cfa3 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_fw.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_fw.h
@@ -104,6 +104,33 @@ void fbnic_mbx_clear_cmpl(struct fbnic_dev *fbd,
 void fbnic_mbx_poll(struct fbnic_dev *fbd);
 int fbnic_mbx_poll_tx_ready(struct fbnic_dev *fbd);
 void fbnic_mbx_flush_tx(struct fbnic_dev *fbd);
+
+/**
+ * enum fbnic_fw_self_test_codes - return codes from self test routines
+ *
+ * These are the codes returned from the self test routines and
+ * stored in the test result array indexed by the specific
+ * test name.
+ *
+ * @FBNIC_TEST_FW_SUCCESS: test success
+ * @FBNIC_TEST_FW_NO_FIRMWARE: FW interface not present
+ * @FBNIC_TEST_FW_NO_CMPL: No completion available
+ * @FBNIC_TEST_FW_NO_XMIT: Could not xmit message
+ * @FBNIC_TEST_FW_NO_MSG: no message returned
+ * @FBNIC_TEST_FW_PARSE: returned message had parsing error
+ */
+enum fbnic_fw_self_test_codes {
+	FBNIC_TEST_FW_SUCCESS = 0,
+	FBNIC_TEST_FW_NO_FIRMWARE = 10,
+	FBNIC_TEST_FW_NO_CMPL = 20,
+	FBNIC_TEST_FW_NO_XMIT = 30,
+	FBNIC_TEST_FW_NO_MSG = 40,
+	FBNIC_TEST_FW_PARSE = 50,
+};
+
+enum fbnic_fw_self_test_codes fbnic_fw_mbx_self_test(struct fbnic_dev *fbd);
+int fbnic_fw_xmit_test_msg(struct fbnic_dev *fbd,
+			   struct fbnic_fw_completion *c);
 int fbnic_fw_xmit_ownership_msg(struct fbnic_dev *fbd, bool take_ownership);
 int fbnic_fw_init_heartbeat(struct fbnic_dev *fbd, bool poll);
 void fbnic_fw_check_heartbeat(struct fbnic_dev *fbd);
-- 
2.43.0