1 #include <linux/export.h> 2 #include <linux/if_vlan.h> 3 #include <net/ip.h> 4 #include <net/tso.h> 5 #include <asm/unaligned.h> 6 7 /* Calculate expected number of TX descriptors */ 8 int tso_count_descs(struct sk_buff *skb) 9 { 10 /* The Marvell Way */ 11 return skb_shinfo(skb)->gso_segs * 2 + skb_shinfo(skb)->nr_frags; 12 } 13 EXPORT_SYMBOL(tso_count_descs); 14 15 void tso_build_hdr(struct sk_buff *skb, char *hdr, struct tso_t *tso, 16 int size, bool is_last) 17 { 18 struct tcphdr *tcph; 19 int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb); 20 int mac_hdr_len = skb_network_offset(skb); 21 22 memcpy(hdr, skb->data, hdr_len); 23 if (!tso->ipv6) { 24 struct iphdr *iph = (void *)(hdr + mac_hdr_len); 25 26 iph->id = htons(tso->ip_id); 27 iph->tot_len = htons(size + hdr_len - mac_hdr_len); 28 tso->ip_id++; 29 } else { 30 struct ipv6hdr *iph = (void *)(hdr + mac_hdr_len); 31 32 iph->payload_len = htons(size + tcp_hdrlen(skb)); 33 } 34 tcph = (struct tcphdr *)(hdr + skb_transport_offset(skb)); 35 put_unaligned_be32(tso->tcp_seq, &tcph->seq); 36 37 if (!is_last) { 38 /* Clear all special flags for not last packet */ 39 tcph->psh = 0; 40 tcph->fin = 0; 41 tcph->rst = 0; 42 } 43 } 44 EXPORT_SYMBOL(tso_build_hdr); 45 46 void tso_build_data(struct sk_buff *skb, struct tso_t *tso, int size) 47 { 48 tso->tcp_seq += size; 49 tso->size -= size; 50 tso->data += size; 51 52 if ((tso->size == 0) && 53 (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) { 54 skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx]; 55 56 /* Move to next segment */ 57 tso->size = frag->size; 58 tso->data = page_address(frag->page.p) + frag->page_offset; 59 tso->next_frag_idx++; 60 } 61 } 62 EXPORT_SYMBOL(tso_build_data); 63 64 void tso_start(struct sk_buff *skb, struct tso_t *tso) 65 { 66 int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb); 67 68 tso->ip_id = ntohs(ip_hdr(skb)->id); 69 tso->tcp_seq = ntohl(tcp_hdr(skb)->seq); 70 tso->next_frag_idx = 0; 71 tso->ipv6 = vlan_get_protocol(skb) == htons(ETH_P_IPV6); 72 73 /* Build first data */ 74 tso->size = skb_headlen(skb) - hdr_len; 75 tso->data = skb->data + hdr_len; 76 if ((tso->size == 0) && 77 (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) { 78 skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx]; 79 80 /* Move to next segment */ 81 tso->size = frag->size; 82 tso->data = page_address(frag->page.p) + frag->page_offset; 83 tso->next_frag_idx++; 84 } 85 } 86 EXPORT_SYMBOL(tso_start); 87