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