+/**
+ * build_hdr_data - creates L2/L3/L4 header data buffer
+ * @hdr_field - bitfield determining needed headers
+ * @skb - socket buffer
+ * @hdr_len - array of header lengths
+ * @tot_len - total length of data
+ *
+ * Reads hdr_field to determine which headers are needed by firmware.
+ * Builds a buffer containing these headers. Saves individual header
+ * lengths and total buffer length to be used to build descriptors.
+ */
+static int build_hdr_data(u8 hdr_field, struct sk_buff *skb,
+ int *hdr_len, u8 *hdr_data)
+{
+ int len = 0;
+ u8 *hdr;
+
+ hdr_len[0] = sizeof(struct ethhdr);
+
+ if (skb->protocol == htons(ETH_P_IP)) {
+ hdr_len[1] = ip_hdr(skb)->ihl * 4;
+ if (ip_hdr(skb)->protocol == IPPROTO_TCP)
+ hdr_len[2] = tcp_hdrlen(skb);
+ else if (ip_hdr(skb)->protocol == IPPROTO_UDP)
+ hdr_len[2] = sizeof(struct udphdr);
+ } else if (skb->protocol == htons(ETH_P_IPV6)) {
+ hdr_len[1] = sizeof(struct ipv6hdr);
+ if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
+ hdr_len[2] = tcp_hdrlen(skb);
+ else if (ipv6_hdr(skb)->nexthdr == IPPROTO_UDP)
+ hdr_len[2] = sizeof(struct udphdr);
+ }
+
+ memset(hdr_data, 0, 120);
+ if ((hdr_field >> 6) & 1) {
+ hdr = skb_mac_header(skb);
+ memcpy(hdr_data, hdr, hdr_len[0]);
+ len += hdr_len[0];
+ }
+
+ if ((hdr_field >> 5) & 1) {
+ hdr = skb_network_header(skb);
+ memcpy(hdr_data + len, hdr, hdr_len[1]);
+ len += hdr_len[1];
+ }
+
+ if ((hdr_field >> 4) & 1) {
+ hdr = skb_transport_header(skb);
+ memcpy(hdr_data + len, hdr, hdr_len[2]);
+ len += hdr_len[2];
+ }
+ return len;
+}
+
+/**
+ * create_hdr_descs - create header and header extension descriptors
+ * @hdr_field - bitfield determining needed headers
+ * @data - buffer containing header data
+ * @len - length of data buffer
+ * @hdr_len - array of individual header lengths
+ * @scrq_arr - descriptor array
+ *
+ * Creates header and, if needed, header extension descriptors and
+ * places them in a descriptor array, scrq_arr
+ */
+
+static void create_hdr_descs(u8 hdr_field, u8 *hdr_data, int len, int *hdr_len,
+ union sub_crq *scrq_arr)
+{
+ union sub_crq hdr_desc;
+ int tmp_len = len;
+ u8 *data, *cur;
+ int tmp;
+
+ while (tmp_len > 0) {
+ cur = hdr_data + len - tmp_len;
+
+ memset(&hdr_desc, 0, sizeof(hdr_desc));
+ if (cur != hdr_data) {
+ data = hdr_desc.hdr_ext.data;
+ tmp = tmp_len > 29 ? 29 : tmp_len;
+ hdr_desc.hdr_ext.first = IBMVNIC_CRQ_CMD;
+ hdr_desc.hdr_ext.type = IBMVNIC_HDR_EXT_DESC;
+ hdr_desc.hdr_ext.len = tmp;
+ } else {
+ data = hdr_desc.hdr.data;
+ tmp = tmp_len > 24 ? 24 : tmp_len;
+ hdr_desc.hdr.first = IBMVNIC_CRQ_CMD;
+ hdr_desc.hdr.type = IBMVNIC_HDR_DESC;
+ hdr_desc.hdr.len = tmp;
+ hdr_desc.hdr.l2_len = (u8)hdr_len[0];
+ hdr_desc.hdr.l3_len = cpu_to_be16((u16)hdr_len[1]);
+ hdr_desc.hdr.l4_len = (u8)hdr_len[2];
+ hdr_desc.hdr.flag = hdr_field << 1;
+ }
+ memcpy(data, cur, tmp);
+ tmp_len -= tmp;
+ *scrq_arr = hdr_desc;
+ scrq_arr++;
+ }
+}
+
+/**
+ * build_hdr_descs_arr - build a header descriptor array
+ * @skb - socket buffer
+ * @num_entries - number of descriptors to be sent
+ * @subcrq - first TX descriptor
+ * @hdr_field - bit field determining which headers will be sent
+ *
+ * This function will build a TX descriptor array with applicable
+ * L2/L3/L4 packet header descriptors to be sent by send_subcrq_indirect.
+ */
+
+static void build_hdr_descs_arr(struct ibmvnic_tx_buff *txbuff,
+ int *num_entries, u8 hdr_field)
+{
+ int hdr_len[3] = {0, 0, 0};
+ int tot_len, len;
+ u8 *hdr_data = txbuff->hdr_data;
+
+ tot_len = build_hdr_data(hdr_field, txbuff->skb, hdr_len,
+ txbuff->hdr_data);
+ len = tot_len;
+ len -= 24;
+ if (len > 0)
+ num_entries += len % 29 ? len / 29 + 1 : len / 29;
+ create_hdr_descs(hdr_field, hdr_data, tot_len, hdr_len,
+ txbuff->indir_arr + 1);
+}
+