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(const 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(const struct sk_buff *skb, char *hdr, struct tso_t *tso, 17 int size, bool is_last) 18 { 19 int hdr_len = skb_transport_offset(skb) + tso->tlen; 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 + tso->tlen); 33 } 34 hdr += skb_transport_offset(skb); 35 if (tso->tlen != sizeof(struct udphdr)) { 36 struct tcphdr *tcph = (struct tcphdr *)hdr; 37 38 put_unaligned_be32(tso->tcp_seq, &tcph->seq); 39 40 if (!is_last) { 41 /* Clear all special flags for not last packet */ 42 tcph->psh = 0; 43 tcph->fin = 0; 44 tcph->rst = 0; 45 } 46 } else { 47 struct udphdr *uh = (struct udphdr *)hdr; 48 49 uh->len = htons(sizeof(*uh) + size); 50 } 51 } 52 EXPORT_SYMBOL(tso_build_hdr); 53 54 void tso_build_data(const struct sk_buff *skb, struct tso_t *tso, int size) 55 { 56 tso->tcp_seq += size; /* not worth avoiding this operation for UDP */ 57 tso->size -= size; 58 tso->data += size; 59 60 if ((tso->size == 0) && 61 (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) { 62 skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx]; 63 64 /* Move to next segment */ 65 tso->size = skb_frag_size(frag); 66 tso->data = skb_frag_address(frag); 67 tso->next_frag_idx++; 68 } 69 } 70 EXPORT_SYMBOL(tso_build_data); 71 72 int tso_start(struct sk_buff *skb, struct tso_t *tso) 73 { 74 int tlen = skb_is_gso_tcp(skb) ? tcp_hdrlen(skb) : sizeof(struct udphdr); 75 int hdr_len = skb_transport_offset(skb) + tlen; 76 77 tso->tlen = tlen; 78 tso->ip_id = ntohs(ip_hdr(skb)->id); 79 tso->tcp_seq = (tlen != sizeof(struct udphdr)) ? ntohl(tcp_hdr(skb)->seq) : 0; 80 tso->next_frag_idx = 0; 81 tso->ipv6 = vlan_get_protocol(skb) == htons(ETH_P_IPV6); 82 83 /* Build first data */ 84 tso->size = skb_headlen(skb) - hdr_len; 85 tso->data = skb->data + hdr_len; 86 if ((tso->size == 0) && 87 (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) { 88 skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx]; 89 90 /* Move to next segment */ 91 tso->size = skb_frag_size(frag); 92 tso->data = skb_frag_address(frag); 93 tso->next_frag_idx++; 94 } 95 return hdr_len; 96 } 97 EXPORT_SYMBOL(tso_start); 98