[PATCH V3 net-next 3/6] ethtool: add support to set/get rx buf len via ethtool

@@ -841,6 +841,7 @@ Kernel response contents:
   ``ETHTOOL_A_RINGS_RX_MINI``           u32     size of RX mini ring
   ``ETHTOOL_A_RINGS_RX_JUMBO``          u32     size of RX jumbo ring
   ``ETHTOOL_A_RINGS_TX``                u32     size of TX ring
+  ``ETHTOOL_A_RINGS_RX_BUF_LEN``        u32     size of buffers on the ring
   ====================================  ======  ==========================
 
 

@@ -857,6 +858,7 @@ Request contents:
   ``ETHTOOL_A_RINGS_RX_MINI``           u32     size of RX mini ring
   ``ETHTOOL_A_RINGS_RX_JUMBO``          u32     size of RX jumbo ring
   ``ETHTOOL_A_RINGS_TX``                u32     size of TX ring
+  ``ETHTOOL_A_RINGS_RX_BUF_LEN``        u32     size of buffers on the ring
   ====================================  ======  ==========================
 
 Kernel checks that requested ring sizes do not exceed limits reported by

@@ -67,6 +67,14 @@ enum {
 	ETH_RSS_HASH_FUNCS_COUNT
 };
 
+/**
+ * enum ethtool_supported_ring_param - indicator caps for setting ring params
+ * @ETHTOOL_RING_USE_RX_BUF_LEN: capture for setting rx_buf_len
+ */
+enum ethtool_supported_ring_param {
+	ETHTOOL_RING_USE_RX_BUF_LEN = BIT(0),
+};
+
 #define __ETH_RSS_HASH_BIT(bit)	((u32)1 << (bit))
 #define __ETH_RSS_HASH(name)	__ETH_RSS_HASH_BIT(ETH_RSS_HASH_##name##_BIT)
 

@@ -420,6 +428,7 @@ struct ethtool_module_eeprom {
  * @cap_link_lanes_supported: indicates if the driver supports lanes
  *	parameter.
  * @supported_coalesce_params: supported types of interrupt coalescing.
+ * @supported_ring_params: supported ring params.
  * @get_drvinfo: Report driver/device information.  Should only set the
  *	@driver, @version, @fw_version and @bus_info fields.  If not
  *	implemented, the @driver and @bus_info fields will be filled in

@@ -596,6 +605,7 @@ struct ethtool_module_eeprom {
 struct ethtool_ops {
 	u32     cap_link_lanes_supported:1;
 	u32	supported_coalesce_params;
+	u32	supported_ring_params;
 	void	(*get_drvinfo)(struct net_device *, struct ethtool_drvinfo *);
 	int	(*get_regs_len)(struct net_device *);
 	void	(*get_regs)(struct net_device *, struct ethtool_regs *, void *);

@@ -535,6 +535,14 @@ struct ethtool_ringparam {
 	__u32	tx_pending;
 };
 
+/**
+ * struct ethtool_ringparam_ext - RX/TX ring configuration
+ * @rx_buf_len: Current length of buffers on the rx ring.
+ */
+struct ethtool_ringparam_ext {
+	__u32	rx_buf_len;
+};
+
 /**
  * struct ethtool_channels - configuring number of network channel
  * @cmd: ETHTOOL_{G,S}CHANNELS

@@ -325,6 +325,7 @@ enum {
 	ETHTOOL_A_RINGS_RX_MINI,			/* u32 */
 	ETHTOOL_A_RINGS_RX_JUMBO,			/* u32 */
 	ETHTOOL_A_RINGS_TX,				/* u32 */
+	ETHTOOL_A_RINGS_RX_BUF_LEN,                     /* u32 */
 
 	/* add new constants above here */
 	__ETHTOOL_A_RINGS_CNT,

@@ -355,7 +355,7 @@ extern const struct nla_policy ethnl_features_set_policy[ETHTOOL_A_FEATURES_WANT
 extern const struct nla_policy ethnl_privflags_get_policy[ETHTOOL_A_PRIVFLAGS_HEADER + 1];
 extern const struct nla_policy ethnl_privflags_set_policy[ETHTOOL_A_PRIVFLAGS_FLAGS + 1];
 extern const struct nla_policy ethnl_rings_get_policy[ETHTOOL_A_RINGS_HEADER + 1];
-extern const struct nla_policy ethnl_rings_set_policy[ETHTOOL_A_RINGS_TX + 1];
+extern const struct nla_policy ethnl_rings_set_policy[ETHTOOL_A_RINGS_RX_BUF_LEN + 1];
 extern const struct nla_policy ethnl_channels_get_policy[ETHTOOL_A_CHANNELS_HEADER + 1];
 extern const struct nla_policy ethnl_channels_set_policy[ETHTOOL_A_CHANNELS_COMBINED_COUNT + 1];
 extern const struct nla_policy ethnl_coalesce_get_policy[ETHTOOL_A_COALESCE_HEADER + 1];

@@ -10,6 +10,7 @@ struct rings_req_info {
 struct rings_reply_data {
 	struct ethnl_reply_data		base;
 	struct ethtool_ringparam	ringparam;
+	struct ethtool_ringparam_ext	ringparam_ext;
 };
 
 #define RINGS_REPDATA(__reply_base) \

@@ -49,7 +50,8 @@ static int rings_reply_size(const struct ethnl_req_info *req_base,
 	       nla_total_size(sizeof(u32)) +	/* _RINGS_RX */
 	       nla_total_size(sizeof(u32)) +	/* _RINGS_RX_MINI */
 	       nla_total_size(sizeof(u32)) +	/* _RINGS_RX_JUMBO */
-	       nla_total_size(sizeof(u32));	/* _RINGS_TX */
+	       nla_total_size(sizeof(u32)) +	/* _RINGS_TX */
+	       nla_total_size(sizeof(u32));     /* _RINGS_RX_BUF_LEN */
 }
 
 static int rings_fill_reply(struct sk_buff *skb,

@@ -105,10 +107,12 @@ const struct nla_policy ethnl_rings_set_policy[] = {
 	[ETHTOOL_A_RINGS_RX_MINI]		= { .type = NLA_U32 },
 	[ETHTOOL_A_RINGS_RX_JUMBO]		= { .type = NLA_U32 },
 	[ETHTOOL_A_RINGS_TX]			= { .type = NLA_U32 },
+	[ETHTOOL_A_RINGS_RX_BUF_LEN]            = NLA_POLICY_MIN(NLA_U32, 1),
 };
 
 int ethnl_set_rings(struct sk_buff *skb, struct genl_info *info)
 {
+	struct ethtool_ringparam_ext ringparam_ext = {};
 	struct ethtool_ringparam ringparam = {};
 	struct ethnl_req_info req_info = {};
 	struct nlattr **tb = info->attrs;

@@ -142,6 +146,8 @@ int ethnl_set_rings(struct sk_buff *skb, struct genl_info *info)
 	ethnl_update_u32(&ringparam.rx_jumbo_pending,
 			 tb[ETHTOOL_A_RINGS_RX_JUMBO], &mod);
 	ethnl_update_u32(&ringparam.tx_pending, tb[ETHTOOL_A_RINGS_TX], &mod);
+	ethnl_update_u32(&ringparam_ext.rx_buf_len,
+			 tb[ETHTOOL_A_RINGS_RX_BUF_LEN], &mod);
 	ret = 0;
 	if (!mod)
 		goto out_ops;

@@ -164,6 +170,15 @@ int ethnl_set_rings(struct sk_buff *skb, struct genl_info *info)
 		goto out_ops;
 	}
 
+	if (ringparam_ext.rx_buf_len != 0 &&
+	    !(ops->supported_ring_params & ETHTOOL_RING_USE_RX_BUF_LEN)) {
+		ret = -EOPNOTSUPP;
+		NL_SET_ERR_MSG_ATTR(info->extack,
+				    tb[ETHTOOL_A_RINGS_RX_BUF_LEN],
+				    "setting not supported rx buf len");
+		goto out_ops;
+	}
+
 	ret = dev->ethtool_ops->set_ringparam(dev, &ringparam);
 	if (ret < 0)
 		goto out_ops;