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 */
tso_count_descs(const struct sk_buff * skb)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
tso_build_hdr(const struct sk_buff * skb,char * hdr,struct tso_t * tso,int size,bool is_last)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
tso_build_data(const struct sk_buff * skb,struct tso_t * tso,int size)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
tso_start(struct sk_buff * skb,struct tso_t * tso)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