diff --git a/Documentation/networking/netdev-features.txt b/Documentation/networking/netdev-features.txt index 7413eb05223b..c77f9d57eb91 100644 --- a/Documentation/networking/netdev-features.txt +++ b/Documentation/networking/netdev-features.txt @@ -163,3 +163,12 @@ This requests that the NIC receive all possible frames, including errored frames (such as bad FCS, etc). This can be helpful when sniffing a link with bad packets on it. Some NICs may receive more packets if also put into normal PROMISC mode. + +* rx-gro-hw + +This requests that the NIC enables Hardware GRO (generic receive offload). +Hardware GRO is basically the exact reverse of TSO, and is generally +stricter than Hardware LRO. A packet stream merged by Hardware GRO must +be re-segmentable by GSO or TSO back to the exact original packet stream. +Hardware GRO is dependent on RXCSUM since every packet successfully merged +by hardware must also have the checksum verified by hardware. diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h index b1b0ca7ccb2b..db84c516bcfb 100644 --- a/include/linux/netdev_features.h +++ b/include/linux/netdev_features.h @@ -78,6 +78,8 @@ enum { NETIF_F_HW_ESP_TX_CSUM_BIT, /* ESP with TX checksum offload */ NETIF_F_RX_UDP_TUNNEL_PORT_BIT, /* Offload of RX port for UDP tunnels */ + NETIF_F_GRO_HW_BIT, /* Hardware Generic receive offload */ + /* * Add your fresh new feature above and remember to update * netdev_features_strings[] in net/core/ethtool.c and maybe @@ -97,6 +99,7 @@ enum { #define NETIF_F_FRAGLIST __NETIF_F(FRAGLIST) #define NETIF_F_FSO __NETIF_F(FSO) #define NETIF_F_GRO __NETIF_F(GRO) +#define NETIF_F_GRO_HW __NETIF_F(GRO_HW) #define NETIF_F_GSO __NETIF_F(GSO) #define NETIF_F_GSO_ROBUST __NETIF_F(GSO_ROBUST) #define NETIF_F_HIGHDMA __NETIF_F(HIGHDMA) diff --git a/net/core/dev.c b/net/core/dev.c index b0eee49a2489..4b43f5dcabcd 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -7424,6 +7424,18 @@ static netdev_features_t netdev_fix_features(struct net_device *dev, features &= ~dev->gso_partial_features; } + if (!(features & NETIF_F_RXCSUM)) { + /* NETIF_F_GRO_HW implies doing RXCSUM since every packet + * successfully merged by hardware must also have the + * checksum verified by hardware. If the user does not + * want to enable RXCSUM, logically, we should disable GRO_HW. + */ + if (features & NETIF_F_GRO_HW) { + netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n"); + features &= ~NETIF_F_GRO_HW; + } + } + return features; } diff --git a/net/core/ethtool.c b/net/core/ethtool.c index f8fcf450a36e..50a79203043b 100644 --- a/net/core/ethtool.c +++ b/net/core/ethtool.c @@ -73,6 +73,7 @@ static const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] [NETIF_F_LLTX_BIT] = "tx-lockless", [NETIF_F_NETNS_LOCAL_BIT] = "netns-local", [NETIF_F_GRO_BIT] = "rx-gro", + [NETIF_F_GRO_HW_BIT] = "rx-gro-hw", [NETIF_F_LRO_BIT] = "rx-lro", [NETIF_F_TSO_BIT] = "tx-tcp-segmentation",