Merge tag 'for-linus-7.1-1' of https://github.com/cminyard/linux-ipmi

Pull ipmi updates from Corey Minyard:
 "Small updates and fixes (mostly to the BMC software):

   - Fix one issue in the host side driver where a kthread can be left
     running on a specific memory allocation failre at probe time

   - Replace system_wq with system_percpu_wq so system_wq can eventually
     go away"

* tag 'for-linus-7.1-1' of https://github.com/cminyard/linux-ipmi:
  ipmi:ssif: Clean up kthread on errors
  ipmi:ssif: Remove unnecessary indention
  ipmi: ssif_bmc: Fix KUnit test link failure when KUNIT=m
  ipmi: ssif_bmc: add unit test for state machine
  ipmi: ssif_bmc: change log level to dbg in irq callback
  ipmi: ssif_bmc: fix message desynchronization after truncated response
  ipmi: ssif_bmc: fix missing check for copy_to_user() partial failure
  ipmi: ssif_bmc: cancel response timer on remove
  ipmi: Replace use of system_wq with system_percpu_wq

4 files changed, 435 insertions, 31 deletions

diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
index 92bed266d07c..669f76000197 100644
--- a/drivers/char/ipmi/Kconfig
+++ b/drivers/char/ipmi/Kconfig
@@ -187,6 +187,16 @@ config SSIF_IPMI_BMC
 	  The driver implements the BMC side of the SMBus system
 	  interface (SSIF).
 
+config SSIF_IPMI_BMC_KUNIT_TEST
+	bool "KUnit tests for SSIF IPMI BMC driver" if !KUNIT_ALL_TESTS
+	depends on KUNIT=y
+	depends on SSIF_IPMI_BMC
+	default KUNIT_ALL_TESTS
+	help
+	  This option builds unit tests that exercise the SSIF BMC state
+	  machine, including request handling, response transmission,
+	  and error paths such as aborted or truncated transfers.
+
 config IPMB_DEVICE_INTERFACE
 	tristate 'IPMB Interface handler'
 	depends on I2C
diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index c41f51c82edd..869ac87a4b6a 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -987,7 +987,7 @@ static int deliver_response(struct ipmi_smi *intf, struct ipmi_recv_msg *msg)
 		mutex_lock(&intf->user_msgs_mutex);
 		list_add_tail(&msg->link, &intf->user_msgs);
 		mutex_unlock(&intf->user_msgs_mutex);
-		queue_work(system_wq, &intf->smi_work);
+		queue_work(system_percpu_wq, &intf->smi_work);
 	}
 
 	return rv;
@@ -4977,7 +4977,7 @@ void ipmi_smi_msg_received(struct ipmi_smi *intf,
 	if (run_to_completion)
 		smi_work(&intf->smi_work);
 	else
-		queue_work(system_wq, &intf->smi_work);
+		queue_work(system_percpu_wq, &intf->smi_work);
 }
 EXPORT_SYMBOL(ipmi_smi_msg_received);
 
@@ -4987,7 +4987,7 @@ void ipmi_smi_watchdog_pretimeout(struct ipmi_smi *intf)
 		return;
 
 	atomic_set(&intf->watchdog_pretimeouts_to_deliver, 1);
-	queue_work(system_wq, &intf->smi_work);
+	queue_work(system_percpu_wq, &intf->smi_work);
 }
 EXPORT_SYMBOL(ipmi_smi_watchdog_pretimeout);
 
@@ -5162,7 +5162,7 @@ static bool ipmi_timeout_handler(struct ipmi_smi *intf,
 				       flags);
 	}
 
-	queue_work(system_wq, &intf->smi_work);
+	queue_work(system_percpu_wq, &intf->smi_work);
 
 	return need_timer;
 }
@@ -5218,7 +5218,7 @@ static void ipmi_timeout(struct timer_list *unused)
 	if (atomic_read(&stop_operation))
 		return;
 
-	queue_work(system_wq, &ipmi_timer_work);
+	queue_work(system_percpu_wq, &ipmi_timer_work);
 }
 
 static void need_waiter(struct ipmi_smi *intf)
diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
index 37a5cb5c53f1..b49500a1bd36 100644
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -1268,8 +1268,10 @@ static void shutdown_ssif(void *send_info)
 	ssif_info->stopping = true;
 	timer_delete_sync(&ssif_info->watch_timer);
 	timer_delete_sync(&ssif_info->retry_timer);
-	if (ssif_info->thread)
+	if (ssif_info->thread) {
 		kthread_stop(ssif_info->thread);
+		ssif_info->thread = NULL;
+	}
 }
 
 static void ssif_remove(struct i2c_client *client)
@@ -1658,6 +1660,7 @@ static int ssif_probe(struct i2c_client *client)
 	int               len = 0;
 	int               i;
 	u8		  slave_addr = 0;
+	unsigned int      thread_num;
 	struct ssif_addr_info *addr_info = NULL;
 
 	mutex_lock(&ssif_infos_mutex);
@@ -1876,22 +1879,17 @@ static int ssif_probe(struct i2c_client *client)
 	ssif_info->handlers.request_events = request_events;
 	ssif_info->handlers.set_need_watch = ssif_set_need_watch;
 
-	{
-		unsigned int thread_num;
-
-		thread_num = ((i2c_adapter_id(ssif_info->client->adapter)
-			       << 8) |
-			      ssif_info->client->addr);
-		init_completion(&ssif_info->wake_thread);
-		ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
-					       "kssif%4.4x", thread_num);
-		if (IS_ERR(ssif_info->thread)) {
-			rv = PTR_ERR(ssif_info->thread);
-			dev_notice(&ssif_info->client->dev,
-				   "Could not start kernel thread: error %d\n",
-				   rv);
-			goto out;
-		}
+	thread_num = ((i2c_adapter_id(ssif_info->client->adapter) << 8) |
+		      ssif_info->client->addr);
+	init_completion(&ssif_info->wake_thread);
+	ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
+					"kssif%4.4x", thread_num);
+	if (IS_ERR(ssif_info->thread)) {
+		rv = PTR_ERR(ssif_info->thread);
+		dev_notice(&ssif_info->client->dev,
+			   "Could not start kernel thread: error %d\n",
+			   rv);
+		goto out;
 	}
 
 	dev_set_drvdata(&ssif_info->client->dev, ssif_info);
@@ -1916,6 +1914,15 @@ static int ssif_probe(struct i2c_client *client)
 
  out:
 	if (rv) {
+		/*
+		 * If ipmi_register_smi() starts the interface, it will
+		 * call shutdown and that will free the thread and set
+		 * it to NULL.  Otherwise it must be freed here.
+		 */
+		if (ssif_info->thread) {
+			kthread_stop(ssif_info->thread);
+			ssif_info->thread = NULL;
+		}
 		if (addr_info)
 			addr_info->client = NULL;
 
diff --git a/drivers/char/ipmi/ssif_bmc.c b/drivers/char/ipmi/ssif_bmc.c
index 7a52e3ea49ed..1df0e9284ad9 100644
--- a/drivers/char/ipmi/ssif_bmc.c
+++ b/drivers/char/ipmi/ssif_bmc.c
@@ -18,6 +18,9 @@
 #include <linux/timer.h>
 #include <linux/jiffies.h>
 #include <linux/ipmi_ssif_bmc.h>
+#if IS_ENABLED(CONFIG_SSIF_IPMI_BMC_KUNIT_TEST)
+#include <kunit/test.h>
+#endif
 
 #define DEVICE_NAME                             "ipmi-ssif-host"
 
@@ -163,6 +166,8 @@ static ssize_t ssif_bmc_read(struct file *file, char __user *buf, size_t count,
 		spin_unlock_irqrestore(&ssif_bmc->lock, flags);
 
 		ret = copy_to_user(buf, &msg, count);
+		if (ret > 0)
+			ret = -EFAULT;
 	}
 
 	return (ret < 0) ? ret : count;
@@ -456,6 +461,15 @@ static bool supported_write_cmd(u8 cmd)
 	return false;
 }
 
+static bool supported_write_start_cmd(u8 cmd)
+{
+	if (cmd == SSIF_IPMI_SINGLEPART_WRITE ||
+	    cmd == SSIF_IPMI_MULTIPART_WRITE_START)
+		return true;
+
+	return false;
+}
+
 /* Process the IPMI response that will be read by master */
 static void handle_read_processed(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
 {
@@ -558,7 +572,7 @@ static void process_request_part(struct ssif_bmc_ctx *ssif_bmc)
 		len = ssif_bmc->request.len + part->length;
 		/* Do the bound check here, not allow the request len exceed 254 bytes */
 		if (len > IPMI_SSIF_PAYLOAD_MAX) {
-			dev_warn(&ssif_bmc->client->dev,
+			dev_dbg(&ssif_bmc->client->dev,
 				 "Warn: Request exceeded 254 bytes, aborting");
 			/* Request too long, aborting */
 			ssif_bmc->aborting =  true;
@@ -604,7 +618,7 @@ static void on_read_requested_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
 	    ssif_bmc->state == SSIF_START ||
 	    ssif_bmc->state == SSIF_REQ_RECVING ||
 	    ssif_bmc->state == SSIF_RES_SENDING) {
-		dev_warn(&ssif_bmc->client->dev,
+		dev_dbg(&ssif_bmc->client->dev,
 			 "Warn: %s unexpected READ REQUESTED in state=%s\n",
 			 __func__, state_to_string(ssif_bmc->state));
 		ssif_bmc->state = SSIF_ABORTING;
@@ -613,7 +627,7 @@ static void on_read_requested_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
 
 	} else if (ssif_bmc->state == SSIF_SMBUS_CMD) {
 		if (!supported_read_cmd(ssif_bmc->part_buf.smbus_cmd)) {
-			dev_warn(&ssif_bmc->client->dev, "Warn: Unknown SMBus read command=0x%x",
+			dev_dbg(&ssif_bmc->client->dev, "Warn: Unknown SMBus read command=0x%x",
 				 ssif_bmc->part_buf.smbus_cmd);
 			ssif_bmc->aborting = true;
 		}
@@ -648,7 +662,7 @@ static void on_read_processed_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
 	    ssif_bmc->state == SSIF_START ||
 	    ssif_bmc->state == SSIF_REQ_RECVING ||
 	    ssif_bmc->state == SSIF_SMBUS_CMD) {
-		dev_warn(&ssif_bmc->client->dev,
+		dev_dbg(&ssif_bmc->client->dev,
 			 "Warn: %s unexpected READ PROCESSED in state=%s\n",
 			 __func__, state_to_string(ssif_bmc->state));
 		ssif_bmc->state = SSIF_ABORTING;
@@ -673,7 +687,7 @@ static void on_write_requested_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
 	} else if (ssif_bmc->state == SSIF_START ||
 		   ssif_bmc->state == SSIF_REQ_RECVING ||
 		   ssif_bmc->state == SSIF_RES_SENDING) {
-		dev_warn(&ssif_bmc->client->dev,
+		dev_dbg(&ssif_bmc->client->dev,
 			 "Warn: %s unexpected WRITE REQUEST in state=%s\n",
 			 __func__, state_to_string(ssif_bmc->state));
 		ssif_bmc->state = SSIF_ABORTING;
@@ -688,7 +702,7 @@ static void on_write_received_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
 {
 	if (ssif_bmc->state == SSIF_READY ||
 	    ssif_bmc->state == SSIF_RES_SENDING) {
-		dev_warn(&ssif_bmc->client->dev,
+		dev_dbg(&ssif_bmc->client->dev,
 			 "Warn: %s unexpected WRITE RECEIVED in state=%s\n",
 			 __func__, state_to_string(ssif_bmc->state));
 		ssif_bmc->state = SSIF_ABORTING;
@@ -698,7 +712,7 @@ static void on_write_received_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
 
 	} else if (ssif_bmc->state == SSIF_SMBUS_CMD) {
 		if (!supported_write_cmd(ssif_bmc->part_buf.smbus_cmd)) {
-			dev_warn(&ssif_bmc->client->dev, "Warn: Unknown SMBus write command=0x%x",
+			dev_dbg(&ssif_bmc->client->dev, "Warn: Unknown SMBus write command=0x%x",
 				 ssif_bmc->part_buf.smbus_cmd);
 			ssif_bmc->aborting = true;
 		}
@@ -707,6 +721,11 @@ static void on_write_received_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
 			ssif_bmc->state = SSIF_ABORTING;
 		else
 			ssif_bmc->state = SSIF_REQ_RECVING;
+	} else if (ssif_bmc->state == SSIF_ABORTING) {
+		if (supported_write_start_cmd(*val)) {
+			ssif_bmc->state = SSIF_SMBUS_CMD;
+			ssif_bmc->aborting = false;
+		}
 	}
 
 	/* This is response sending state */
@@ -722,7 +741,7 @@ static void on_stop_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val)
 	    ssif_bmc->state == SSIF_START ||
 	    ssif_bmc->state == SSIF_SMBUS_CMD ||
 	    ssif_bmc->state == SSIF_ABORTING) {
-		dev_warn(&ssif_bmc->client->dev,
+		dev_dbg(&ssif_bmc->client->dev,
 			 "Warn: %s unexpected SLAVE STOP in state=%s\n",
 			 __func__, state_to_string(ssif_bmc->state));
 		ssif_bmc->state = SSIF_READY;
@@ -789,7 +808,7 @@ static int ssif_bmc_cb(struct i2c_client *client, enum i2c_slave_event event, u8
 		break;
 
 	default:
-		dev_warn(&ssif_bmc->client->dev, "Warn: Unknown i2c slave event\n");
+		dev_dbg(&ssif_bmc->client->dev, "Warn: Unknown i2c slave event\n");
 		break;
 	}
 
@@ -843,6 +862,7 @@ static void ssif_bmc_remove(struct i2c_client *client)
 {
 	struct ssif_bmc_ctx *ssif_bmc = i2c_get_clientdata(client);
 
+	timer_delete_sync(&ssif_bmc->response_timer);
 	i2c_slave_unregister(client);
 	misc_deregister(&ssif_bmc->miscdev);
 }
@@ -869,6 +889,373 @@ static struct i2c_driver ssif_bmc_driver = {
 	.id_table       = ssif_bmc_id,
 };
 
+#if IS_ENABLED(CONFIG_SSIF_IPMI_BMC_KUNIT_TEST)
+struct ssif_bmc_test_ctx {
+	struct ssif_bmc_ctx ssif_bmc;
+	struct i2c_client client;
+	struct i2c_adapter adapter;
+	struct i2c_algorithm algo;
+};
+
+static int ssif_bmc_test_init(struct kunit *test)
+{
+	struct ssif_bmc_test_ctx *test_ctx;
+
+	test_ctx = kunit_kzalloc(test, sizeof(*test_ctx), GFP_KERNEL);
+	if (!test_ctx)
+		return -ENOMEM;
+
+	test_ctx->adapter.algo = &test_ctx->algo;
+	test_ctx->client.addr = 0x20;
+	test_ctx->client.adapter = &test_ctx->adapter;
+
+	spin_lock_init(&test_ctx->ssif_bmc.lock);
+	init_waitqueue_head(&test_ctx->ssif_bmc.wait_queue);
+	test_ctx->ssif_bmc.client = &test_ctx->client;
+	i2c_set_clientdata(&test_ctx->client, &test_ctx->ssif_bmc);
+
+	test->priv = test_ctx;
+
+	return 0;
+}
+
+static void ssif_bmc_test_exit(struct kunit *test)
+{
+	struct ssif_bmc_test_ctx *test_ctx = test->priv;
+
+	if (test_ctx->ssif_bmc.response_timer_inited)
+		timer_delete_sync(&test_ctx->ssif_bmc.response_timer);
+}
+
+static int ssif_bmc_test_run_event_val(struct ssif_bmc_test_ctx *test_ctx,
+					       enum i2c_slave_event event,
+					       u8 *value)
+{
+	return ssif_bmc_cb(&test_ctx->client, event, value);
+}
+
+static int ssif_bmc_test_run_event(struct ssif_bmc_test_ctx *test_ctx,
+					   enum i2c_slave_event event, u8 value)
+{
+	return ssif_bmc_test_run_event_val(test_ctx, event, &value);
+}
+
+static void ssif_bmc_test_singlepart_req(struct kunit *test)
+{
+	struct ssif_bmc_test_ctx *test_ctx = test->priv;
+	struct ssif_bmc_ctx *ssif_bmc = &test_ctx->ssif_bmc;
+
+	ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_REQUESTED,
+				GET_8BIT_ADDR(test_ctx->client.addr));
+	ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED,
+				SSIF_IPMI_SINGLEPART_WRITE);
+	ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 2);
+
+	ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 0xaa);
+
+	ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 0x55);
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_STOP, 0), -EBUSY);
+
+	KUNIT_EXPECT_EQ(test, ssif_bmc->state, SSIF_READY);
+	KUNIT_EXPECT_TRUE(test, ssif_bmc->request_available);
+	KUNIT_EXPECT_TRUE(test, ssif_bmc->busy);
+	KUNIT_EXPECT_FALSE(test, ssif_bmc->aborting);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->request.len, 2);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->request.payload[0], 0xaa);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->request.payload[1], 0x55);
+	KUNIT_EXPECT_TRUE(test, ssif_bmc->response_timer_inited);
+}
+
+static void ssif_bmc_test_restart_write_without_stop(struct kunit *test)
+{
+	struct ssif_bmc_test_ctx *test_ctx = test->priv;
+	struct ssif_bmc_ctx *ssif_bmc = &test_ctx->ssif_bmc;
+
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_REQUESTED,
+						GET_8BIT_ADDR(test_ctx->client.addr)), 0);
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED,
+						SSIF_IPMI_SINGLEPART_WRITE), 0);
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 2), 0);
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 0xde), 0);
+
+	KUNIT_EXPECT_EQ(test, ssif_bmc->state, SSIF_REQ_RECVING);
+
+	/* Write transaction, without stop, and new request coming */
+	ssif_bmc_test_singlepart_req(test);
+}
+
+
+static void ssif_bmc_test_restart_after_invalid_command(struct kunit *test)
+{
+	struct ssif_bmc_test_ctx *test_ctx = test->priv;
+	struct ssif_bmc_ctx *ssif_bmc = &test_ctx->ssif_bmc;
+
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_REQUESTED,
+						GET_8BIT_ADDR(test_ctx->client.addr)), 0);
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 0xff), 0);
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 1), 0);
+
+	KUNIT_EXPECT_EQ(test, ssif_bmc->state, SSIF_ABORTING);
+	KUNIT_EXPECT_TRUE(test, ssif_bmc->aborting);
+
+	/* After An Invalid Command, expect could handle new request */
+	ssif_bmc_test_singlepart_req(test);
+}
+
+static void ssif_bmc_test_singlepart_read_response_completion(struct kunit *test)
+{
+	struct ssif_bmc_test_ctx *test_ctx = test->priv;
+	struct ssif_bmc_ctx *ssif_bmc = &test_ctx->ssif_bmc;
+	u8 value;
+
+	ssif_bmc->state = SSIF_SMBUS_CMD;
+	ssif_bmc->part_buf.smbus_cmd = SSIF_IPMI_SINGLEPART_READ;
+	ssif_bmc->response.len = 2;
+	ssif_bmc->response.payload[0] = 0x11;
+	ssif_bmc->response.payload[1] = 0x22;
+	ssif_bmc->response_in_progress = true;
+	ssif_bmc->is_singlepart_read = true;
+	ssif_bmc->pec_support = true;
+
+	value = 0;
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event_val(test_ctx, I2C_SLAVE_READ_REQUESTED,
+						    &value), 0);
+	KUNIT_EXPECT_EQ(test, value, 2);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->state, SSIF_RES_SENDING);
+
+	value = 0;
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event_val(test_ctx, I2C_SLAVE_READ_PROCESSED,
+						    &value), 0);
+	KUNIT_EXPECT_EQ(test, value, 0x11);
+
+	value = 0;
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event_val(test_ctx, I2C_SLAVE_READ_PROCESSED,
+						    &value), 0);
+	KUNIT_EXPECT_EQ(test, value, 0x22);
+
+	value = 0;
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event_val(test_ctx, I2C_SLAVE_READ_PROCESSED,
+						    &value), 0);
+	KUNIT_EXPECT_EQ(test, value, ssif_bmc->part_buf.pec);
+
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_STOP, 0), 0);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->state, SSIF_READY);
+	KUNIT_EXPECT_FALSE(test, ssif_bmc->response_in_progress);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->response.len, 0);
+}
+
+static void ssif_bmc_test_stop_during_start_discards_partial_request(struct kunit *test)
+{
+	struct ssif_bmc_test_ctx *test_ctx = test->priv;
+	struct ssif_bmc_ctx *ssif_bmc = &test_ctx->ssif_bmc;
+
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_REQUESTED,
+						GET_8BIT_ADDR(test_ctx->client.addr)), 0);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->state, SSIF_START);
+
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_STOP, 0), 0);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->state, SSIF_READY);
+	KUNIT_EXPECT_FALSE(test, ssif_bmc->request_available);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->msg_idx, 0);
+
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_REQUESTED,
+						GET_8BIT_ADDR(test_ctx->client.addr)), 0);
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED,
+						SSIF_IPMI_SINGLEPART_WRITE), 0);
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 1), 0);
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 0x77), 0);
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_STOP, 0), -EBUSY);
+
+	KUNIT_EXPECT_TRUE(test, ssif_bmc->request_available);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->request.len, 1);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->request.payload[0], 0x77);
+}
+
+static void ssif_bmc_test_read_interrupts_partial_write(struct kunit *test)
+{
+	struct ssif_bmc_test_ctx *test_ctx = test->priv;
+	struct ssif_bmc_ctx *ssif_bmc = &test_ctx->ssif_bmc;
+	u8 value = 0xff;
+
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_REQUESTED,
+						GET_8BIT_ADDR(test_ctx->client.addr)), 0);
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED,
+						SSIF_IPMI_SINGLEPART_WRITE), 0);
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 2), 0);
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 0xab), 0);
+
+	KUNIT_EXPECT_EQ(test, ssif_bmc->state, SSIF_REQ_RECVING);
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event_val(test_ctx, I2C_SLAVE_READ_REQUESTED,
+						    &value), 0);
+	KUNIT_EXPECT_EQ(test, value, 0);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->state, SSIF_ABORTING);
+
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_STOP, 0), 0);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->state, SSIF_READY);
+	KUNIT_EXPECT_FALSE(test, ssif_bmc->request_available);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->request.len, 0);
+
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_REQUESTED,
+						GET_8BIT_ADDR(test_ctx->client.addr)), 0);
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED,
+						SSIF_IPMI_SINGLEPART_WRITE), 0);
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 1), 0);
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 0xcd), 0);
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_STOP, 0), -EBUSY);
+
+	KUNIT_EXPECT_TRUE(test, ssif_bmc->request_available);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->request.len, 1);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->request.payload[0], 0xcd);
+}
+
+static void ssif_bmc_test_write_interrupts_response_send(struct kunit *test)
+{
+	struct ssif_bmc_test_ctx *test_ctx = test->priv;
+	struct ssif_bmc_ctx *ssif_bmc = &test_ctx->ssif_bmc;
+	u8 value = 0;
+
+	ssif_bmc->state = SSIF_SMBUS_CMD;
+	ssif_bmc->part_buf.smbus_cmd = SSIF_IPMI_SINGLEPART_READ;
+	ssif_bmc->response.len = 1;
+	ssif_bmc->response.payload[0] = 0x66;
+	ssif_bmc->response_in_progress = true;
+	ssif_bmc->is_singlepart_read = true;
+
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event_val(test_ctx, I2C_SLAVE_READ_REQUESTED,
+						    &value), 0);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->state, SSIF_RES_SENDING);
+
+	/* READ_REQUESTED transaction */
+	ssif_bmc_test_singlepart_req(test);
+}
+
+static void ssif_bmc_test_write_interrupts_response_sending(struct kunit *test)
+{
+	struct ssif_bmc_test_ctx *test_ctx = test->priv;
+	struct ssif_bmc_ctx *ssif_bmc = &test_ctx->ssif_bmc;
+	u8 value = 0;
+
+	ssif_bmc->state = SSIF_SMBUS_CMD;
+	ssif_bmc->part_buf.smbus_cmd = SSIF_IPMI_SINGLEPART_READ;
+	ssif_bmc->response.len = 1;
+	ssif_bmc->response.payload[0] = 0x66;
+	ssif_bmc->response_in_progress = true;
+	ssif_bmc->is_singlepart_read = true;
+
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event_val(test_ctx, I2C_SLAVE_READ_REQUESTED,
+						    &value), 0);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->state, SSIF_RES_SENDING);
+
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event_val(test_ctx, I2C_SLAVE_READ_PROCESSED,
+						    &value), 0);
+	KUNIT_EXPECT_EQ(test, value, 0x66);
+
+	/* READ_REQUESTED transaction */
+	ssif_bmc_test_singlepart_req(test);
+}
+
+static void ssif_bmc_test_timeout_interrupt_allows_retry(struct kunit *test)
+{
+	struct ssif_bmc_test_ctx *test_ctx = test->priv;
+	struct ssif_bmc_ctx *ssif_bmc = &test_ctx->ssif_bmc;
+
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_REQUESTED,
+						GET_8BIT_ADDR(test_ctx->client.addr)), 0);
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED,
+						SSIF_IPMI_SINGLEPART_WRITE), 0);
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 1), 0);
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 0x21), 0);
+	KUNIT_ASSERT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_STOP, 0), -EBUSY);
+
+	KUNIT_ASSERT_TRUE(test, timer_pending(&ssif_bmc->response_timer));
+	timer_delete_sync(&ssif_bmc->response_timer);
+	response_timeout(&ssif_bmc->response_timer);
+
+	KUNIT_EXPECT_FALSE(test, ssif_bmc->busy);
+	KUNIT_EXPECT_TRUE(test, ssif_bmc->aborting);
+	KUNIT_EXPECT_FALSE(test, ssif_bmc->response_timer_inited);
+
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_REQUESTED,
+						GET_8BIT_ADDR(test_ctx->client.addr)), 0);
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED,
+						SSIF_IPMI_SINGLEPART_WRITE), 0);
+	KUNIT_EXPECT_FALSE(test, ssif_bmc->aborting);
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 1), 0);
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_WRITE_RECEIVED, 0x22), 0);
+	KUNIT_EXPECT_EQ(test,
+			ssif_bmc_test_run_event(test_ctx, I2C_SLAVE_STOP, 0), -EBUSY);
+
+	KUNIT_EXPECT_TRUE(test, ssif_bmc->request_available);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->request.len, 1);
+	KUNIT_EXPECT_EQ(test, ssif_bmc->request.payload[0], 0x22);
+}
+
+static struct kunit_case ssif_bmc_test_cases[] = {
+	KUNIT_CASE(ssif_bmc_test_singlepart_req),
+	KUNIT_CASE(ssif_bmc_test_restart_write_without_stop),
+	KUNIT_CASE(ssif_bmc_test_restart_after_invalid_command),
+	KUNIT_CASE(ssif_bmc_test_singlepart_read_response_completion),
+	KUNIT_CASE(ssif_bmc_test_stop_during_start_discards_partial_request),
+	KUNIT_CASE(ssif_bmc_test_read_interrupts_partial_write),
+	KUNIT_CASE(ssif_bmc_test_write_interrupts_response_send),
+	KUNIT_CASE(ssif_bmc_test_write_interrupts_response_sending),
+	KUNIT_CASE(ssif_bmc_test_timeout_interrupt_allows_retry),
+	{}
+};
+
+static struct kunit_suite ssif_bmc_test_suite = {
+	.name = "ssif_bmc_test",
+	.init = ssif_bmc_test_init,
+	.exit = ssif_bmc_test_exit,
+	.test_cases = ssif_bmc_test_cases,
+};
+
+kunit_test_suite(ssif_bmc_test_suite);
+#endif
+
 module_i2c_driver(ssif_bmc_driver);
 
 MODULE_AUTHOR("Quan Nguyen <quan@os.amperecomputing.com>");