drivers: ipmi: Support for both IPMB Req and Resp

Removed check for request or response in IPMB packets coming from
device as well as from host. Now it supports both way communication
to device via IPMB. Both request and response will be passed to
application.
Signed-off-by: Vijay Khemka <vijaykhemka@fb.com>
Message-Id: <20191106182921.1086795-1-vijaykhemka@fb.com>
Reviewed-by: Asmaa Mnebhi <Asmaa@mellanox.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>

drivers/char/ipmi/ipmb_dev_int.c

@@ -133,9 +133,6 @@ static ssize_t ipmb_write(struct file *file, const char __user *buf,
 	rq_sa = GET_7BIT_ADDR(msg[RQ_SA_8BIT_IDX]);
 	netf_rq_lun = msg[NETFN_LUN_IDX];
 
-	if (!(netf_rq_lun & NETFN_RSP_BIT_MASK))
-		return -EINVAL;
-
 	/*
 	 * subtract rq_sa and netf_rq_lun from the length of the msg passed to
 	 * i2c_smbus_xfer
@@ -203,25 +200,16 @@ static u8 ipmb_verify_checksum1(struct ipmb_dev *ipmb_dev, u8 rs_sa)
 		ipmb_dev->request.checksum1);
 }
 
-static bool is_ipmb_request(struct ipmb_dev *ipmb_dev, u8 rs_sa)
+/*
+ * Verify if message has proper ipmb header with minimum length
+ * and correct checksum byte.
+ */
+static bool is_ipmb_msg(struct ipmb_dev *ipmb_dev, u8 rs_sa)
 {
-	if (ipmb_dev->msg_idx >= IPMB_REQUEST_LEN_MIN) {
-		if (ipmb_verify_checksum1(ipmb_dev, rs_sa))
-			return false;
+	if ((ipmb_dev->msg_idx >= IPMB_REQUEST_LEN_MIN) &&
+	   (!ipmb_verify_checksum1(ipmb_dev, rs_sa)))
+		return true;
 
-		/*
-		 * Check whether this is an IPMB request or
-		 * response.
-		 * The 6 MSB of netfn_rs_lun are dedicated to the netfn
-		 * while the remaining bits are dedicated to the lun.
-		 * If the LSB of the netfn is cleared, it is associated
-		 * with an IPMB request.
-		 * If the LSB of the netfn is set, it is associated with
-		 * an IPMB response.
-		 */
-		if (!(ipmb_dev->request.netfn_rs_lun & NETFN_RSP_BIT_MASK))
-			return true;
-	}
 	return false;
 }
 
@@ -273,8 +261,7 @@ static int ipmb_slave_cb(struct i2c_client *client,
 
 	case I2C_SLAVE_STOP:
 		ipmb_dev->request.len = ipmb_dev->msg_idx;
-
-		if (is_ipmb_request(ipmb_dev, GET_8BIT_ADDR(client->addr)))
+		if (is_ipmb_msg(ipmb_dev, GET_8BIT_ADDR(client->addr)))
 			ipmb_handle_request(ipmb_dev);
 		break;