[RFC net-next 1/2] net: ethtool: add ethtool ability to set/get fresh device features

[Jie Wang <wangjie125@huawei.com>]

As tx push is a standard feature for NICs, but netdev_feature which is
controlled by ethtool -K has reached the maximum specification.

so this patch adds a pair of new ethtool messages：'ETHTOOL_GDEVFEAT' and
'ETHTOOL_SDEVFEAT' to be used to set/get features contained entirely to
drivers. The message processing functions and function hooks in struct
ethtool_ops are also added.

set-devfeatures/show-devfeatures option(s) are designed to provide set
and get function.
set cmd:
root@wj: ethtool --set-devfeatures eth4 tx-push [on | off]
get cmd:
root@wj: ethtool --show-devfeatures eth4

Signed-off-by: Jie Wang <wangjie125@huawei.com>
---
 include/linux/ethtool.h      |  4 ++++
 include/uapi/linux/ethtool.h | 27 ++++++++++++++++++++++
 net/ethtool/ioctl.c          | 43 ++++++++++++++++++++++++++++++++++++
 3 files changed, 74 insertions(+)

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 11efc45de66a..1a34bb074720 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -750,6 +750,10 @@ struct ethtool_ops {
 	int	(*set_module_power_mode)(struct net_device *dev,
 					 const struct ethtool_module_power_mode_params *params,
 					 struct netlink_ext_ack *extack);
+	int	(*get_devfeatures)(struct net_device *dev,
+				   struct ethtool_dev_features *dev_feat);
+	int	(*set_devfeatures)(struct net_device *dev,
+				   struct ethtool_dev_features *dev_feat);
 };
 
 int ethtool_check_ops(const struct ethtool_ops *ops);
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 7bc4b8def12c..319d7b2c6acb 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -1490,6 +1490,31 @@ enum ethtool_fec_config_bits {
 #define ETHTOOL_FEC_BASER		(1 << ETHTOOL_FEC_BASER_BIT)
 #define ETHTOOL_FEC_LLRS		(1 << ETHTOOL_FEC_LLRS_BIT)
 
+/**
+ * struct ethtool_dev_features - device feature configurations
+ * @cmd: Command number = %ETHTOOL_GDEVFEAT or %ETHTOOL_SDEVFEAT
+ * @type: feature configuration type.
+ * @data: feature configuration value.
+ */
+struct ethtool_dev_features {
+	__u32 cmd;
+	__u32 type;
+	__u32 data;
+};
+
+/**
+ * enum ethtool_dev_features_type - flags definition of ethtool_dev_features
+ * @ETHTOOL_DEV_TX_PUSH: nic tx push mode set bit.
+ */
+enum ethtool_dev_features_type {
+	ETHTOOL_DEV_TX_PUSH,
+	/*
+	 * Add your fresh feature type above and remember to update
+	 * feat_line[] in ethtool.c
+	 */
+	ETHTOOL_DEV_FEATURE_COUNT,
+};
+
 /* CMDs currently supported */
 #define ETHTOOL_GSET		0x00000001 /* DEPRECATED, Get settings.
 					    * Please use ETHTOOL_GLINKSETTINGS
@@ -1584,6 +1609,8 @@ enum ethtool_fec_config_bits {
 #define ETHTOOL_PHY_STUNABLE	0x0000004f /* Set PHY tunable configuration */
 #define ETHTOOL_GFECPARAM	0x00000050 /* Get FEC settings */
 #define ETHTOOL_SFECPARAM	0x00000051 /* Set FEC settings */
+#define ETHTOOL_GDEVFEAT	0x00000052 /* Get device features */
+#define ETHTOOL_SDEVFEAT	0x00000053 /* Set device features */
 
 /* compatibility with older code */
 #define SPARC_ETH_GSET		ETHTOOL_GSET
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 326e14ee05db..efac23352eb9 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -2722,6 +2722,42 @@ static int ethtool_set_fecparam(struct net_device *dev, void __user *useraddr)
 	return dev->ethtool_ops->set_fecparam(dev, &fecparam);
 }
 
+static int ethtool_get_devfeatures(struct net_device *dev,
+				   void __user *useraddr)
+{
+	struct ethtool_dev_features dev_feat;
+	int ret;
+
+	if (!dev->ethtool_ops->get_devfeatures)
+		return -EOPNOTSUPP;
+
+	if (copy_from_user(&dev_feat, useraddr, sizeof(dev_feat)))
+		return -EFAULT;
+
+	ret = dev->ethtool_ops->get_devfeatures(dev, &dev_feat);
+	if (ret)
+		return ret;
+
+	if (copy_to_user(useraddr, &dev_feat, sizeof(dev_feat)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int ethtool_set_devfeatures(struct net_device *dev,
+				   void __user *useraddr)
+{
+	struct ethtool_dev_features dev_feat;
+
+	if (!dev->ethtool_ops->set_devfeatures)
+		return -EOPNOTSUPP;
+
+	if (copy_from_user(&dev_feat, useraddr, sizeof(dev_feat)))
+		return -EFAULT;
+
+	return dev->ethtool_ops->set_devfeatures(dev, &dev_feat);
+}
+
 /* The main entry point in this file.  Called from net/core/dev_ioctl.c */
 
 static int
@@ -2781,6 +2817,7 @@ __dev_ethtool(struct net *net, struct ifreq *ifr, void __user *useraddr,
 	case ETHTOOL_PHY_GTUNABLE:
 	case ETHTOOL_GLINKSETTINGS:
 	case ETHTOOL_GFECPARAM:
+	case ETHTOOL_GDEVFEAT:
 		break;
 	default:
 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
@@ -3008,6 +3045,12 @@ __dev_ethtool(struct net *net, struct ifreq *ifr, void __user *useraddr,
 	case ETHTOOL_SFECPARAM:
 		rc = ethtool_set_fecparam(dev, useraddr);
 		break;
+	case ETHTOOL_GDEVFEAT:
+		rc = ethtool_get_devfeatures(dev, useraddr);
+		break;
+	case ETHTOOL_SDEVFEAT:
+		rc = ethtool_set_devfeatures(dev, useraddr);
+		break;
 	default:
 		rc = -EOPNOTSUPP;
 	}
-- 
2.33.0