Commit 5eb5f860 authored by Subash Abhinov Kasiviswanathan's avatar Subash Abhinov Kasiviswanathan Committed by David S. Miller

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: default avatarSubash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 23c76eb7
......@@ -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;
......
......@@ -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_ */
......@@ -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;
}
......@@ -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) {
......
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