ixgbe: Add infrastructure code for FCoE large send offload to 82599

#include <scsi/libfc.h>

#include <scsi/libfcoe.h>

/**

 * ixgbe_fso - ixgbe FCoE Sequence Offload (FSO)

 * @adapter: ixgbe adapter

 * @tx_ring: tx desc ring

 * @skb: associated skb

 * @tx_flags: tx flags

 * @hdr_len: hdr_len to be returned

 *

 * This sets up large send offload for FCoE

 *

 * Returns : 0 indicates no FSO, > 0 for FSO, < 0 for error

 */

int ixgbe_fso(struct ixgbe_adapter *adapter,

              struct ixgbe_ring *tx_ring, struct sk_buff *skb,

              u32 tx_flags, u8 *hdr_len)

{

	u8 sof, eof;

	u32 vlan_macip_lens;

	u32 fcoe_sof_eof;

	u32 type_tucmd;

	u32 mss_l4len_idx;

	int mss = 0;

	unsigned int i;

	struct ixgbe_tx_buffer *tx_buffer_info;

	struct ixgbe_adv_tx_context_desc *context_desc;

	struct fc_frame_header *fh;

	if (skb_is_gso(skb) && (skb_shinfo(skb)->gso_type != SKB_GSO_FCOE)) {

		DPRINTK(DRV, ERR, "Wrong gso type %d:expecting SKB_GSO_FCOE\n",

			skb_shinfo(skb)->gso_type);

		return -EINVAL;

	}

	/* resets the header to point fcoe/fc */

	skb_set_network_header(skb, skb->mac_len);

	skb_set_transport_header(skb, skb->mac_len +

				 sizeof(struct fcoe_hdr));

	/* sets up SOF and ORIS */

	fcoe_sof_eof = 0;

	sof = ((struct fcoe_hdr *)skb_network_header(skb))->fcoe_sof;

	switch (sof) {

	case FC_SOF_I2:

		fcoe_sof_eof |= IXGBE_ADVTXD_FCOEF_ORIS;

		break;

	case FC_SOF_I3:

		fcoe_sof_eof |= IXGBE_ADVTXD_FCOEF_SOF;

		fcoe_sof_eof |= IXGBE_ADVTXD_FCOEF_ORIS;

		break;

	case FC_SOF_N2:

		break;

	case FC_SOF_N3:

		fcoe_sof_eof |= IXGBE_ADVTXD_FCOEF_SOF;

		break;

	default:

		DPRINTK(DRV, WARNING, "unknown sof = 0x%x\n", sof);

		return -EINVAL;

	}

	/* the first byte of the last dword is EOF */

	skb_copy_bits(skb, skb->len - 4, &eof, 1);

	/* sets up EOF and ORIE */

	switch (eof) {

	case FC_EOF_N:

		fcoe_sof_eof |= IXGBE_ADVTXD_FCOEF_EOF_N;

		break;

	case FC_EOF_T:

		/* lso needs ORIE */

		if (skb_is_gso(skb)) {

			fcoe_sof_eof |= IXGBE_ADVTXD_FCOEF_EOF_N;

			fcoe_sof_eof |= IXGBE_ADVTXD_FCOEF_ORIE;

		} else {

			fcoe_sof_eof |= IXGBE_ADVTXD_FCOEF_EOF_T;

		}

		break;

	case FC_EOF_NI:

		fcoe_sof_eof |= IXGBE_ADVTXD_FCOEF_EOF_NI;

		break;

	case FC_EOF_A:

		fcoe_sof_eof |= IXGBE_ADVTXD_FCOEF_EOF_A;

		break;

	default:

		DPRINTK(DRV, WARNING, "unknown eof = 0x%x\n", eof);

		return -EINVAL;

	}

	/* sets up PARINC indicating data offset */

	fh = (struct fc_frame_header *)skb_transport_header(skb);

	if (fh->fh_f_ctl[2] & FC_FC_REL_OFF)

		fcoe_sof_eof |= IXGBE_ADVTXD_FCOEF_PARINC;

	/* hdr_len includes fc_hdr if FCoE lso is enabled */

	*hdr_len = sizeof(struct fcoe_crc_eof);

	if (skb_is_gso(skb))

		*hdr_len += (skb_transport_offset(skb) +

			     sizeof(struct fc_frame_header));

	/* vlan_macip_lens: HEADLEN, MACLEN, VLAN tag */

	vlan_macip_lens = (skb_transport_offset(skb) +

			  sizeof(struct fc_frame_header));

	vlan_macip_lens |= ((skb_transport_offset(skb) - 4)

			   << IXGBE_ADVTXD_MACLEN_SHIFT);

	vlan_macip_lens |= (tx_flags & IXGBE_TX_FLAGS_VLAN_MASK);

	/* type_tycmd and mss: set TUCMD.FCoE to enable offload */

	type_tucmd = IXGBE_TXD_CMD_DEXT | IXGBE_ADVTXD_DTYP_CTXT |

		     IXGBE_ADVTXT_TUCMD_FCOE;

	if (skb_is_gso(skb))

		mss = skb_shinfo(skb)->gso_size;

	/* mss_l4len_id: use 1 for FSO as TSO, no need for L4LEN */

	mss_l4len_idx = (mss << IXGBE_ADVTXD_MSS_SHIFT) |

			(1 << IXGBE_ADVTXD_IDX_SHIFT);

	/* write context desc */

	i = tx_ring->next_to_use;

	context_desc = IXGBE_TX_CTXTDESC_ADV(*tx_ring, i);

	context_desc->vlan_macip_lens	= cpu_to_le32(vlan_macip_lens);

	context_desc->seqnum_seed	= cpu_to_le32(fcoe_sof_eof);

	context_desc->type_tucmd_mlhl	= cpu_to_le32(type_tucmd);

	context_desc->mss_l4len_idx	= cpu_to_le32(mss_l4len_idx);

	tx_buffer_info = &tx_ring->tx_buffer_info[i];

	tx_buffer_info->time_stamp = jiffies;

	tx_buffer_info->next_to_watch = i;

	i++;

	if (i == tx_ring->count)

		i = 0;

	tx_ring->next_to_use = i;

	return skb_is_gso(skb);

}

/**

 * ixgbe_configure_fcoe - configures registers for fcoe at start

 * @adapter: ptr to ixgbe adapter