1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/export.h> 3 #include <linux/if_vlan.h> 4 #include <net/ip.h> 5 #include <net/tso.h> 6 #include <asm/unaligned.h> 7 8 /* Calculate expected number of TX descriptors */ 9 int tso_count_descs(struct sk_buff *skb) 10 { 11 /* The Marvell Way */ 12 return skb_shinfo(skb)->gso_segs * 2 + skb_shinfo(skb)->nr_frags; 13 } 14 EXPORT_SYMBOL(tso_count_descs); 15 16 void tso_build_hdr(struct sk_buff *skb, char *hdr, struct tso_t *tso, 17 int size, bool is_last) 18 { 19 struct tcphdr *tcph; 20 int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb); 21 int mac_hdr_len = skb_network_offset(skb); 22 23 memcpy(hdr, skb->data, hdr_len); 24 if (!tso->ipv6) { 25 struct iphdr *iph = (void *)(hdr + mac_hdr_len); 26 27 iph->id = htons(tso->ip_id); 28 iph->tot_len = htons(size + hdr_len - mac_hdr_len); 29 tso->ip_id++; 30 } else { 31 struct ipv6hdr *iph = (void *)(hdr + mac_hdr_len); 32 33 iph->payload_len = htons(size + tcp_hdrlen(skb)); 34 } 35 tcph = (struct tcphdr *)(hdr + skb_transport_offset(skb)); 36 put_unaligned_be32(tso->tcp_seq, &tcph->seq); 37 38 if (!is_last) { 39 /* Clear all special flags for not last packet */ 40 tcph->psh = 0; 41 tcph->fin = 0; 42 tcph->rst = 0; 43 } 44 } 45 EXPORT_SYMBOL(tso_build_hdr); 46 47 void tso_build_data(struct sk_buff *skb, struct tso_t *tso, int size) 48 { 49 tso->tcp_seq += size; 50 tso->size -= size; 51 tso->data += size; 52 53 if ((tso->size == 0) && 54 (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) { 55 skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx]; 56 57 /* Move to next segment */ 58 tso->size = skb_frag_size(frag); 59 tso->data = skb_frag_address(frag); 60 tso->next_frag_idx++; 61 } 62 } 63 EXPORT_SYMBOL(tso_build_data); 64 65 void tso_start(struct sk_buff *skb, struct tso_t *tso) 66 { 67 int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb); 68 69 tso->ip_id = ntohs(ip_hdr(skb)->id); 70 tso->tcp_seq = ntohl(tcp_hdr(skb)->seq); 71 tso->next_frag_idx = 0; 72 tso->ipv6 = vlan_get_protocol(skb) == htons(ETH_P_IPV6); 73 74 /* Build first data */ 75 tso->size = skb_headlen(skb) - hdr_len; 76 tso->data = skb->data + hdr_len; 77 if ((tso->size == 0) && 78 (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) { 79 skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx]; 80 81 /* Move to next segment */ 82 tso->size = skb_frag_size(frag); 83 tso->data = skb_frag_address(frag); 84 tso->next_frag_idx++; 85 } 86 } 87 EXPORT_SYMBOL(tso_start); 88