[PATCH net-next v3 6/7] net: ethtool: add ring parameter filtering

[Taehee Yoo <ap420073@gmail.com>]

While the devmem is running, the tcp-data-split and
tcp-data-split-thresh configuration should not be changed.
If user tries to change tcp-data-split and threshold value while the
devmem is running, it fails and shows extack message.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v3:
 - Patch added

 net/ethtool/common.h |  1 +
 net/ethtool/rings.c  | 15 ++++++++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/net/ethtool/common.h b/net/ethtool/common.h
index d55d5201b085..beebd4db3e10 100644
--- a/net/ethtool/common.h
+++ b/net/ethtool/common.h
@@ -5,6 +5,7 @@
 
 #include <linux/netdevice.h>
 #include <linux/ethtool.h>
+#include <net/netdev_rx_queue.h>
 
 #define ETHTOOL_DEV_FEATURE_WORDS	DIV_ROUND_UP(NETDEV_FEATURE_COUNT, 32)
 
diff --git a/net/ethtool/rings.c b/net/ethtool/rings.c
index c7824515857f..0afc6b29a229 100644
--- a/net/ethtool/rings.c
+++ b/net/ethtool/rings.c
@@ -216,7 +216,8 @@ ethnl_set_rings(struct ethnl_req_info *req_info, struct genl_info *info)
 	bool mod = false, thresh_mod = false;
 	struct nlattr **tb = info->attrs;
 	const struct nlattr *err_attr;
-	int ret;
+	struct netdev_rx_queue *rxq;
+	int ret, i;
 
 	dev->ethtool_ops->get_ringparam(dev, &ringparam,
 					&kernel_ringparam, info->extack);
@@ -263,6 +264,18 @@ ethnl_set_rings(struct ethnl_req_info *req_info, struct genl_info *info)
 		return -EINVAL;
 	}
 
+	if (kernel_ringparam.tcp_data_split != ETHTOOL_TCP_DATA_SPLIT_ENABLED ||
+	    kernel_ringparam.tcp_data_split_thresh) {
+		for (i = 0; i < dev->real_num_rx_queues; i++) {
+			rxq = __netif_get_rx_queue(dev, i);
+			if (rxq->mp_params.mp_priv) {
+				NL_SET_ERR_MSG(info->extack,
+					       "tcp-header-data-split is disabled or threshold is not zero");
+				return -EINVAL;
+			}
+		}
+	}
+
 	/* ensure new ring parameters are within limits */
 	if (ringparam.rx_pending > ringparam.rx_max_pending)
 		err_attr = tb[ETHTOOL_A_RINGS_RX];
-- 
2.34.1