diff --git a/Documentation/ABI/testing/sysfs-platform-mellanox-bootctl b/Documentation/ABI/testing/sysfs-platform-mellanox-bootctl
index 9b99a81babb1..4c5c02d8f870 100644
--- a/Documentation/ABI/testing/sysfs-platform-mellanox-bootctl
+++ b/Documentation/ABI/testing/sysfs-platform-mellanox-bootctl
@@ -75,3 +75,12 @@ KernelVersion:	6.4
 Contact:	"Liming Sun <limings@nvidia.com>"
 Description:
 		The file used to access the BlueField boot fifo.
+
+What:		/sys/bus/platform/devices/MLNXBF04:00/rsh_log
+Date:		May 2023
+KernelVersion:	6.4
+Contact:	"Liming Sun <limings@nvidia.com>"
+Description:
+		The file used to write BlueField boot log with the format
+                "[INFO|WARN|ERR|ASSERT ]<msg>". Log level 'INFO' is used by
+                default if not specified.
diff --git a/drivers/platform/mellanox/mlxbf-bootctl.c b/drivers/platform/mellanox/mlxbf-bootctl.c
index 1bad1d278672..e88ce68acb89 100644
--- a/drivers/platform/mellanox/mlxbf-bootctl.c
+++ b/drivers/platform/mellanox/mlxbf-bootctl.c
@@ -45,10 +45,38 @@ static const char * const mlxbf_bootctl_lifecycle_states[] = {
 	[3] = "RMA",
 };
 
+/* Log header format. */
+#define MLXBF_RSH_LOG_TYPE_SHIFT	56
+#define MLXBF_RSH_LOG_LEN_SHIFT		48
+#define MLXBF_RSH_LOG_LEVEL_SHIFT	0
+
+/* Log module ID and type (only MSG type in Linux driver for now). */
+#define MLXBF_RSH_LOG_TYPE_MSG		0x04ULL
+
+/* Log ctl/data register offset. */
+#define MLXBF_RSH_SCRATCH_BUF_CTL_OFF	0
+#define MLXBF_RSH_SCRATCH_BUF_DATA_OFF	0x10
+
+/* Log message levels. */
+enum {
+	MLXBF_RSH_LOG_INFO,
+	MLXBF_RSH_LOG_WARN,
+	MLXBF_RSH_LOG_ERR
+};
+
 /* Mapped pointer for RSH_BOOT_FIFO_DATA and RSH_BOOT_FIFO_COUNT register. */
 static void __iomem *mlxbf_rsh_boot_data;
 static void __iomem *mlxbf_rsh_boot_cnt;
 
+/* Mapped pointer for rsh log semaphore/ctrl/data register. */
+static void __iomem *mlxbf_rsh_semaphore;
+static void __iomem *mlxbf_rsh_scratch_buf_ctl;
+static void __iomem *mlxbf_rsh_scratch_buf_data;
+
+/* Rsh log levels. */
+static const char * const mlxbf_rsh_log_level[] = {
+	"INFO", "WARN", "ERR", "ASSERT"};
+
 /* ARM SMC call which is atomic and no need for lock. */
 static int mlxbf_bootctl_smc(unsigned int smc_op, int smc_arg)
 {
@@ -266,12 +294,111 @@ static ssize_t fw_reset_store(struct device *dev,
 	return count;
 }
 
+/* Size(8-byte words) of the log buffer. */
+#define RSH_SCRATCH_BUF_CTL_IDX_MASK	0x7f
+
+static int mlxbf_rsh_log_sem_lock(void)
+{
+	unsigned long timeout;
+
+	/* Take the semaphore. */
+	timeout = jiffies + msecs_to_jiffies(100);
+	while (readq(mlxbf_rsh_semaphore)) {
+		if (time_after(jiffies, timeout))
+			return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static void mlxbf_rsh_log_sem_unlock(void)
+{
+	writeq(0, mlxbf_rsh_semaphore);
+}
+
+static ssize_t rsh_log_store(struct device *dev,
+			     struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	int rc, idx, num, len, size = (int)count, level = MLXBF_RSH_LOG_INFO;
+	u64 data;
+
+	if (!size)
+		return -EINVAL;
+
+	if (!mlxbf_rsh_semaphore || !mlxbf_rsh_scratch_buf_ctl)
+		return -EOPNOTSUPP;
+
+	/* Ignore line break at the end. */
+	if (buf[size - 1] == '\n')
+		size--;
+
+	/* Check the message prefix. */
+	for (idx = 0; idx < ARRAY_SIZE(mlxbf_rsh_log_level); idx++) {
+		len = strlen(mlxbf_rsh_log_level[idx]);
+		if (len + 1 < size &&
+		    !strncmp(buf, mlxbf_rsh_log_level[idx], len)) {
+			buf += len;
+			size -= len;
+			level = idx;
+			break;
+		}
+	}
+
+	/* Ignore leading spaces. */
+	while (size > 0 && buf[0] == ' ') {
+		size--;
+		buf++;
+	}
+
+	/* Take the semaphore. */
+	rc = mlxbf_rsh_log_sem_lock();
+	if (rc)
+		return rc;
+
+	/* Calculate how many words are available. */
+	num = (size + sizeof(u64) - 1) / sizeof(u64);
+	idx = readq(mlxbf_rsh_scratch_buf_ctl);
+	if (idx + num + 1 >= RSH_SCRATCH_BUF_CTL_IDX_MASK)
+		num = RSH_SCRATCH_BUF_CTL_IDX_MASK - idx - 1;
+	if (num <= 0)
+		goto done;
+
+	/* Write Header. */
+	data = (MLXBF_RSH_LOG_TYPE_MSG << MLXBF_RSH_LOG_TYPE_SHIFT) |
+		((u64)num << MLXBF_RSH_LOG_LEN_SHIFT) |
+		((u64)level << MLXBF_RSH_LOG_LEVEL_SHIFT);
+	writeq(data, mlxbf_rsh_scratch_buf_data);
+
+	/* Write message. */
+	for (idx = 0, len = size; idx < num && len > 0; idx++) {
+		if (len <= sizeof(u64)) {
+			data = 0;
+			memcpy(&data, buf, len);
+			len = 0;
+		} else {
+			memcpy(&data, buf, sizeof(u64));
+			len -= sizeof(u64);
+			buf += sizeof(u64);
+		}
+		writeq(data, mlxbf_rsh_scratch_buf_data);
+	}
+
+done:
+	/* Release the semaphore. */
+	mlxbf_rsh_log_sem_unlock();
+
+	/* Ignore the rest if no more space. */
+	return count;
+}
+
 static DEVICE_ATTR_RW(post_reset_wdog);
 static DEVICE_ATTR_RW(reset_action);
 static DEVICE_ATTR_RW(second_reset_action);
 static DEVICE_ATTR_RO(lifecycle_state);
 static DEVICE_ATTR_RO(secure_boot_fuse_state);
 static DEVICE_ATTR_WO(fw_reset);
+static DEVICE_ATTR_WO(rsh_log);
 
 static struct attribute *mlxbf_bootctl_attrs[] = {
 	&dev_attr_post_reset_wdog.attr,
@@ -280,6 +407,7 @@ static struct attribute *mlxbf_bootctl_attrs[] = {
 	&dev_attr_lifecycle_state.attr,
 	&dev_attr_secure_boot_fuse_state.attr,
 	&dev_attr_fw_reset.attr,
+	&dev_attr_rsh_log.attr,
 	NULL
 };
 
@@ -345,6 +473,7 @@ static bool mlxbf_bootctl_guid_match(const guid_t *guid,
 static int mlxbf_bootctl_probe(struct platform_device *pdev)
 {
 	struct arm_smccc_res res = { 0 };
+	void __iomem *reg;
 	guid_t guid;
 	int ret;
 
@@ -358,6 +487,18 @@ static int mlxbf_bootctl_probe(struct platform_device *pdev)
 	if (IS_ERR(mlxbf_rsh_boot_cnt))
 		return PTR_ERR(mlxbf_rsh_boot_cnt);
 
+	/* Get the resource of the bootfifo counter register. */
+	mlxbf_rsh_semaphore = devm_platform_ioremap_resource(pdev, 2);
+	if (IS_ERR(mlxbf_rsh_semaphore))
+		return PTR_ERR(mlxbf_rsh_semaphore);
+
+	/* Get the resource of the bootfifo counter register. */
+	reg = devm_platform_ioremap_resource(pdev, 3);
+	if (IS_ERR(reg))
+		return PTR_ERR(reg);
+	mlxbf_rsh_scratch_buf_ctl = reg + MLXBF_RSH_SCRATCH_BUF_CTL_OFF;
+	mlxbf_rsh_scratch_buf_data = reg + MLXBF_RSH_SCRATCH_BUF_DATA_OFF;
+
 	/* Ensure we have the UUID we expect for this service. */
 	arm_smccc_smc(MLXBF_BOOTCTL_SIP_SVC_UID, 0, 0, 0, 0, 0, 0, 0, &res);
 	guid_parse(mlxbf_bootctl_svc_uuid_str, &guid);
