diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c
index e5b2d1465e7e..5c0706e632f3 100644
--- a/drivers/i2c/i2c-core-smbus.c
+++ b/drivers/i2c/i2c-core-smbus.c
@@ -303,7 +303,8 @@ static void i2c_smbus_try_get_dmabuf(struct i2c_msg *msg, u8 init_val)
 	bool is_read = msg->flags & I2C_M_RD;
 	unsigned char *dma_buf;
 
-	dma_buf = kzalloc(I2C_SMBUS_BLOCK_MAX + (is_read ? 2 : 3), GFP_KERNEL);
+	dma_buf = kzalloc(I2C_SMBUS3_BLOCK_MAX + (is_read ? 2 : 3),
+		GFP_KERNEL);
 	if (!dma_buf)
 		return;
 
@@ -329,9 +330,10 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 	 * initialize most things with sane defaults, to keep the code below
 	 * somewhat simpler.
 	 */
-	unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3];
-	unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2];
+	unsigned char msgbuf0[I2C_SMBUS3_BLOCK_MAX+3];
+	unsigned char msgbuf1[I2C_SMBUS3_BLOCK_MAX+2];
 	int nmsgs = read_write == I2C_SMBUS_READ ? 2 : 1;
+	u16 block_max;
 	u8 partial_pec = 0;
 	int status;
 	struct i2c_msg msg[2] = {
@@ -350,6 +352,10 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 	bool wants_pec = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK
 			  && size != I2C_SMBUS_I2C_BLOCK_DATA);
 
+	/* Drivers must opt in to 255 byte max block size */
+	block_max = i2c_check_functionality(adapter, I2C_FUNC_SMBUS3_BLOCKSIZE)
+			? I2C_SMBUS3_BLOCK_MAX : I2C_SMBUS_BLOCK_MAX;
+
 	msgbuf0[0] = command;
 	switch (size) {
 	case I2C_SMBUS_QUICK:
@@ -399,7 +405,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 			i2c_smbus_try_get_dmabuf(&msg[1], 0);
 		} else {
 			msg[0].len = data->block[0] + 2;
-			if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
+			if (msg[0].len > block_max + 2) {
 				dev_err(&adapter->dev,
 					"Invalid block write size %d\n",
 					data->block[0]);
@@ -413,7 +419,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 	case I2C_SMBUS_BLOCK_PROC_CALL:
 		nmsgs = 2; /* Another special case */
 		read_write = I2C_SMBUS_READ;
-		if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
+		if (data->block[0] > block_max) {
 			dev_err(&adapter->dev,
 				"Invalid block write size %d\n",
 				data->block[0]);
@@ -430,7 +436,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 		i2c_smbus_try_get_dmabuf(&msg[1], 0);
 		break;
 	case I2C_SMBUS_I2C_BLOCK_DATA:
-		if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
+		if (data->block[0] > block_max) {
 			dev_err(&adapter->dev, "Invalid block %s size %d\n",
 				read_write == I2C_SMBUS_READ ? "read" : "write",
 				data->block[0]);
@@ -498,7 +504,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 			break;
 		case I2C_SMBUS_BLOCK_DATA:
 		case I2C_SMBUS_BLOCK_PROC_CALL:
-			if (msg[1].buf[0] > I2C_SMBUS_BLOCK_MAX) {
+			if (msg[1].buf[0] > block_max) {
 				dev_err(&adapter->dev,
 					"Invalid block size returned: %d\n",
 					msg[1].buf[0]);
diff --git a/include/uapi/linux/i2c.h b/include/uapi/linux/i2c.h
index 92326ebde350..b7e1100ca3be 100644
--- a/include/uapi/linux/i2c.h
+++ b/include/uapi/linux/i2c.h
@@ -108,6 +108,7 @@ struct i2c_msg {
 #define I2C_FUNC_SMBUS_READ_I2C_BLOCK	0x04000000 /* I2C-like block xfer  */
 #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK	0x08000000 /* w/ 1-byte reg. addr. */
 #define I2C_FUNC_SMBUS_HOST_NOTIFY	0x10000000 /* SMBus 2.0 or later */
+#define I2C_FUNC_SMBUS3_BLOCKSIZE	0x20000000 /* Device supports 255 byte block */
 
 #define I2C_FUNC_SMBUS_BYTE		(I2C_FUNC_SMBUS_READ_BYTE | \
 					 I2C_FUNC_SMBUS_WRITE_BYTE)
@@ -137,11 +138,13 @@ struct i2c_msg {
 /*
  * Data for SMBus Messages
  */
-#define I2C_SMBUS_BLOCK_MAX	32	/* As specified in SMBus standard */
+#define I2C_SMBUS_BLOCK_MAX	32	/* As specified in SMBus standard < 3.0 */
+#define I2C_SMBUS3_BLOCK_MAX	255	/* As specified in SMBus 3.0 */
+
 union i2c_smbus_data {
 	__u8 byte;
 	__u16 word;
-	__u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
+	__u8 block[I2C_SMBUS3_BLOCK_MAX + 2]; /* block[0] is used for length */
 			       /* and one more for user-space compatibility */
 };
 
@@ -156,9 +159,12 @@ union i2c_smbus_data {
 #define I2C_SMBUS_BYTE_DATA	    2
 #define I2C_SMBUS_WORD_DATA	    3
 #define I2C_SMBUS_PROC_CALL	    4
-#define I2C_SMBUS_BLOCK_DATA	    5
+#define I2C_SMBUS1_BLOCK_DATA	    5 /* Legacy 32 byte block limit */
 #define I2C_SMBUS_I2C_BLOCK_BROKEN  6
-#define I2C_SMBUS_BLOCK_PROC_CALL   7		/* SMBus 2.0 */
-#define I2C_SMBUS_I2C_BLOCK_DATA    8
+#define I2C_SMBUS1_BLOCK_PROC_CALL  7 /* SMBus 2.0, legacy 32 byte block limit */
+#define I2C_SMBUS1_I2C_BLOCK_DATA   8 /* Legacy 32 byte block limit */
+#define I2C_SMBUS_BLOCK_DATA        9 /* Smbus 3.0, 255 byte limit */
+#define I2C_SMBUS_BLOCK_PROC_CALL  10 /* Smbus 3.0, 255 byte limit */
+#define I2C_SMBUS_I2C_BLOCK_DATA   11 /* Smbus 3.0, 255 byte limit */
 
 #endif /* _UAPI_LINUX_I2C_H */
