From 5eb5f8608ef118c2cfefc10c8dbbb89b14fac506 Mon Sep 17 00:00:00 2001 From: Subash Abhinov Kasiviswanathan Date: Sun, 7 Jan 2018 11:36:39 -0700 Subject: [PATCH] net: qualcomm: rmnet: Add support for TX checksum offload TX checksum offload applies to TCP / UDP packets which are not fragmented using the MAPv4 checksum trailer. The following needs to be done to have checksum computed in hardware - 1. Set the checksum start offset and inset offset. 2. Set the csum_enabled bit 3. Compute and set 1's complement of partial checksum field in transport header. Signed-off-by: Subash Abhinov Kasiviswanathan Signed-off-by: David S. Miller --- .../net/ethernet/qualcomm/rmnet/rmnet_handlers.c | 8 ++ drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h | 2 + .../net/ethernet/qualcomm/rmnet/rmnet_map_data.c | 120 +++++++++++++++++++++ drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c | 1 + 4 files changed, 131 insertions(+) diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c index 3409458..601edec 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c @@ -141,11 +141,19 @@ static int rmnet_map_egress_handler(struct sk_buff *skb, additional_header_len = 0; required_headroom = sizeof(struct rmnet_map_header); + if (port->data_format & RMNET_EGRESS_FORMAT_MAP_CKSUMV4) { + additional_header_len = sizeof(struct rmnet_map_ul_csum_header); + required_headroom += additional_header_len; + } + if (skb_headroom(skb) < required_headroom) { if (pskb_expand_head(skb, required_headroom, 0, GFP_KERNEL)) goto fail; } + if (port->data_format & RMNET_EGRESS_FORMAT_MAP_CKSUMV4) + rmnet_map_checksum_uplink_packet(skb, orig_dev); + map_header = rmnet_map_add_map_header(skb, additional_header_len, 0); if (!map_header) goto fail; diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h index ca9f473..6ce31e2 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h @@ -89,5 +89,7 @@ struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb, int hdrlen, int pad); void rmnet_map_command(struct sk_buff *skb, struct rmnet_port *port); int rmnet_map_checksum_downlink_packet(struct sk_buff *skb, u16 len); +void rmnet_map_checksum_uplink_packet(struct sk_buff *skb, + struct net_device *orig_dev); #endif /* _RMNET_MAP_H_ */ diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c index 881c1dc..c74a6c56 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c @@ -171,6 +171,86 @@ rmnet_map_ipv6_dl_csum_trailer(struct sk_buff *skb, } #endif +static void rmnet_map_complement_ipv4_txporthdr_csum_field(void *iphdr) +{ + struct iphdr *ip4h = (struct iphdr *)iphdr; + void *txphdr; + u16 *csum; + + txphdr = iphdr + ip4h->ihl * 4; + + if (ip4h->protocol == IPPROTO_TCP || ip4h->protocol == IPPROTO_UDP) { + csum = (u16 *)rmnet_map_get_csum_field(ip4h->protocol, txphdr); + *csum = ~(*csum); + } +} + +static void +rmnet_map_ipv4_ul_csum_header(void *iphdr, + struct rmnet_map_ul_csum_header *ul_header, + struct sk_buff *skb) +{ + struct iphdr *ip4h = (struct iphdr *)iphdr; + __be16 *hdr = (__be16 *)ul_header, offset; + + offset = htons((__force u16)(skb_transport_header(skb) - + (unsigned char *)iphdr)); + ul_header->csum_start_offset = offset; + ul_header->csum_insert_offset = skb->csum_offset; + ul_header->csum_enabled = 1; + if (ip4h->protocol == IPPROTO_UDP) + ul_header->udp_ip4_ind = 1; + else + ul_header->udp_ip4_ind = 0; + + /* Changing remaining fields to network order */ + hdr++; + *hdr = htons((__force u16)*hdr); + + skb->ip_summed = CHECKSUM_NONE; + + rmnet_map_complement_ipv4_txporthdr_csum_field(iphdr); +} + +#if IS_ENABLED(CONFIG_IPV6) +static void rmnet_map_complement_ipv6_txporthdr_csum_field(void *ip6hdr) +{ + struct ipv6hdr *ip6h = (struct ipv6hdr *)ip6hdr; + void *txphdr; + u16 *csum; + + txphdr = ip6hdr + sizeof(struct ipv6hdr); + + if (ip6h->nexthdr == IPPROTO_TCP || ip6h->nexthdr == IPPROTO_UDP) { + csum = (u16 *)rmnet_map_get_csum_field(ip6h->nexthdr, txphdr); + *csum = ~(*csum); + } +} + +static void +rmnet_map_ipv6_ul_csum_header(void *ip6hdr, + struct rmnet_map_ul_csum_header *ul_header, + struct sk_buff *skb) +{ + __be16 *hdr = (__be16 *)ul_header, offset; + + offset = htons((__force u16)(skb_transport_header(skb) - + (unsigned char *)ip6hdr)); + ul_header->csum_start_offset = offset; + ul_header->csum_insert_offset = skb->csum_offset; + ul_header->csum_enabled = 1; + ul_header->udp_ip4_ind = 0; + + /* Changing remaining fields to network order */ + hdr++; + *hdr = htons((__force u16)*hdr); + + skb->ip_summed = CHECKSUM_NONE; + + rmnet_map_complement_ipv6_txporthdr_csum_field(ip6hdr); +} +#endif + /* Adds MAP header to front of skb->data * Padding is calculated and set appropriately in MAP header. Mux ID is * initialized to 0. @@ -281,3 +361,43 @@ int rmnet_map_checksum_downlink_packet(struct sk_buff *skb, u16 len) return 0; } + +/* Generates UL checksum meta info header for IPv4 and IPv6 over TCP and UDP + * packets that are supported for UL checksum offload. + */ +void rmnet_map_checksum_uplink_packet(struct sk_buff *skb, + struct net_device *orig_dev) +{ + struct rmnet_map_ul_csum_header *ul_header; + void *iphdr; + + ul_header = (struct rmnet_map_ul_csum_header *) + skb_push(skb, sizeof(struct rmnet_map_ul_csum_header)); + + if (unlikely(!(orig_dev->features & + (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)))) + goto sw_csum; + + if (skb->ip_summed == CHECKSUM_PARTIAL) { + iphdr = (char *)ul_header + + sizeof(struct rmnet_map_ul_csum_header); + + if (skb->protocol == htons(ETH_P_IP)) { + rmnet_map_ipv4_ul_csum_header(iphdr, ul_header, skb); + return; + } else if (skb->protocol == htons(ETH_P_IPV6)) { +#if IS_ENABLED(CONFIG_IPV6) + rmnet_map_ipv6_ul_csum_header(iphdr, ul_header, skb); + return; +#else + goto sw_csum; +#endif + } + } + +sw_csum: + ul_header->csum_start_offset = 0; + ul_header->csum_insert_offset = 0; + ul_header->csum_enabled = 0; + ul_header->udp_ip4_ind = 0; +} diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c index 879a2e0..f7f57ce 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c @@ -189,6 +189,7 @@ int rmnet_vnd_newlink(u8 id, struct net_device *rmnet_dev, return -EBUSY; rmnet_dev->hw_features = NETIF_F_RXCSUM; + rmnet_dev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM; rc = register_netdevice(rmnet_dev); if (!rc) { -- 2.7.4