1 files changed, 97 insertions, 0 deletions
diff --git a/net/core/tso.c b/net/core/tso.c
new file mode 100644
index 000000000..4148f6d48
--- /dev/null
+++ b/net/core/tso.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/export.h>
+#include <linux/if_vlan.h>
+#include <net/ip.h>
+#include <net/tso.h>
+#include <asm/unaligned.h>
+
+/* Calculate expected number of TX descriptors */
+int tso_count_descs(const struct sk_buff *skb)
+{
+	/* The Marvell Way */
+	return skb_shinfo(skb)->gso_segs * 2 + skb_shinfo(skb)->nr_frags;
+}
+EXPORT_SYMBOL(tso_count_descs);
+
+void tso_build_hdr(const struct sk_buff *skb, char *hdr, struct tso_t *tso,
+		   int size, bool is_last)
+{
+	int hdr_len = skb_transport_offset(skb) + tso->tlen;
+	int mac_hdr_len = skb_network_offset(skb);
+
+	memcpy(hdr, skb->data, hdr_len);
+	if (!tso->ipv6) {
+		struct iphdr *iph = (void *)(hdr + mac_hdr_len);
+
+		iph->id = htons(tso->ip_id);
+		iph->tot_len = htons(size + hdr_len - mac_hdr_len);
+		tso->ip_id++;
+	} else {
+		struct ipv6hdr *iph = (void *)(hdr + mac_hdr_len);
+
+		iph->payload_len = htons(size + tso->tlen);
+	}
+	hdr += skb_transport_offset(skb);
+	if (tso->tlen != sizeof(struct udphdr)) {
+		struct tcphdr *tcph = (struct tcphdr *)hdr;
+
+		put_unaligned_be32(tso->tcp_seq, &tcph->seq);
+
+		if (!is_last) {
+			/* Clear all special flags for not last packet */
+			tcph->psh = 0;
+			tcph->fin = 0;
+			tcph->rst = 0;
+		}
+	} else {
+		struct udphdr *uh = (struct udphdr *)hdr;
+
+		uh->len = htons(sizeof(*uh) + size);
+	}
+}
+EXPORT_SYMBOL(tso_build_hdr);
+
+void tso_build_data(const struct sk_buff *skb, struct tso_t *tso, int size)
+{
+	tso->tcp_seq += size; /* not worth avoiding this operation for UDP */
+	tso->size -= size;
+	tso->data += size;
+
+	if ((tso->size == 0) &&
+	    (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) {
+		skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx];
+
+		/* Move to next segment */
+		tso->size = skb_frag_size(frag);
+		tso->data = skb_frag_address(frag);
+		tso->next_frag_idx++;
+	}
+}
+EXPORT_SYMBOL(tso_build_data);
+
+int tso_start(struct sk_buff *skb, struct tso_t *tso)
+{
+	int tlen = skb_is_gso_tcp(skb) ? tcp_hdrlen(skb) : sizeof(struct udphdr);
+	int hdr_len = skb_transport_offset(skb) + tlen;
+
+	tso->tlen = tlen;
+	tso->ip_id = ntohs(ip_hdr(skb)->id);
+	tso->tcp_seq = (tlen != sizeof(struct udphdr)) ? ntohl(tcp_hdr(skb)->seq) : 0;
+	tso->next_frag_idx = 0;
+	tso->ipv6 = vlan_get_protocol(skb) == htons(ETH_P_IPV6);
+
+	/* Build first data */
+	tso->size = skb_headlen(skb) - hdr_len;
+	tso->data = skb->data + hdr_len;
+	if ((tso->size == 0) &&
+	    (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) {
+		skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx];
+
+		/* Move to next segment */
+		tso->size = skb_frag_size(frag);
+		tso->data = skb_frag_address(frag);
+		tso->next_frag_idx++;
+	}
+	return hdr_len;
+}
+EXPORT_SYMBOL(tso_start);