/*******************************************************************************
   *
   * Intel Ethernet Controller XL710 Family Linux Driver
   * Copyright(c) 2013 - 2015 Intel Corporation.
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms and conditions of the GNU General Public License,
   * version 2, as published by the Free Software Foundation.
   *
   * This program is distributed in the hope it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
   * more details.
   *
   * You should have received a copy of the GNU General Public License along
   * with this program.  If not, see <http://www.gnu.org/licenses/>.
   *
   * The full GNU General Public License is included in this distribution in
   * the file called "COPYING".
   *
   * Contact Information:
   * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
   * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
   *
   ******************************************************************************/
  
  #include <linux/if_ether.h>
  #include <scsi/scsi_cmnd.h>
  #include <scsi/scsi_device.h>
  #include <scsi/fc/fc_fs.h>
  #include <scsi/fc/fc_fip.h>
  #include <scsi/fc/fc_fcoe.h>
  #include <scsi/libfc.h>
  #include <scsi/libfcoe.h>
  #include <uapi/linux/dcbnl.h>
  
  #include "i40e.h"
  #include "i40e_fcoe.h"
  
  /**
   * i40e_rx_is_fcoe - returns true if the rx packet type is FCoE
   * @ptype: the packet type field from rx descriptor write-back
   **/
  static inline bool i40e_rx_is_fcoe(u16 ptype)
  {
  	return (ptype >= I40E_RX_PTYPE_L2_FCOE_PAY3) &&
  	       (ptype <= I40E_RX_PTYPE_L2_FCOE_VFT_FCOTHER);
  }
  
  /**
   * i40e_fcoe_sof_is_class2 - returns true if this is a FC Class 2 SOF
   * @sof: the FCoE start of frame delimiter
   **/
  static inline bool i40e_fcoe_sof_is_class2(u8 sof)
  {
  	return (sof == FC_SOF_I2) || (sof == FC_SOF_N2);
  }
  
  /**
   * i40e_fcoe_sof_is_class3 - returns true if this is a FC Class 3 SOF
   * @sof: the FCoE start of frame delimiter
   **/
  static inline bool i40e_fcoe_sof_is_class3(u8 sof)
  {
  	return (sof == FC_SOF_I3) || (sof == FC_SOF_N3);
  }
  
  /**
   * i40e_fcoe_sof_is_supported - returns true if the FC SOF is supported by HW
   * @sof: the input SOF value from the frame
   **/
  static inline bool i40e_fcoe_sof_is_supported(u8 sof)
  {
  	return i40e_fcoe_sof_is_class2(sof) ||
  	       i40e_fcoe_sof_is_class3(sof);
  }
  
  /**
   * i40e_fcoe_fc_sof - pull the SOF from FCoE header in the frame
   * @skb: the frame whose EOF is to be pulled from
   **/
  static inline int i40e_fcoe_fc_sof(struct sk_buff *skb, u8 *sof)
  {
  	*sof = ((struct fcoe_hdr *)skb_network_header(skb))->fcoe_sof;
  
  	if (!i40e_fcoe_sof_is_supported(*sof))
  		return -EINVAL;
  	return 0;
  }
  
  /**
   * i40e_fcoe_eof_is_supported - returns true if the EOF is supported by HW
   * @eof:     the input EOF value from the frame
   **/
  static inline bool i40e_fcoe_eof_is_supported(u8 eof)
  {
  	return (eof == FC_EOF_N) || (eof == FC_EOF_T) ||
  	       (eof == FC_EOF_NI) || (eof == FC_EOF_A);
  }
  
  /**
   * i40e_fcoe_fc_eof - pull EOF from FCoE trailer in the frame
   * @skb: the frame whose EOF is to be pulled from
   **/
  static inline int i40e_fcoe_fc_eof(struct sk_buff *skb, u8 *eof)
  {
  	/* the first byte of the last dword is EOF */
  	skb_copy_bits(skb, skb->len - 4, eof, 1);
  
  	if (!i40e_fcoe_eof_is_supported(*eof))
  		return -EINVAL;
  	return 0;
  }
  
  /**
   * i40e_fcoe_ctxt_eof - convert input FC EOF for descriptor programming
   * @eof: the input eof value from the frame
   *
   * The FC EOF is converted to the value understood by HW for descriptor
   * programming. Never call this w/o calling i40e_fcoe_eof_is_supported()
   * first and that already checks for all supported valid eof values.
   **/
  static inline u32 i40e_fcoe_ctxt_eof(u8 eof)
  {
  	switch (eof) {
  	case FC_EOF_N:
  		return I40E_TX_DESC_CMD_L4T_EOFT_EOF_N;
  	case FC_EOF_T:
  		return I40E_TX_DESC_CMD_L4T_EOFT_EOF_T;
  	case FC_EOF_NI:
  		return I40E_TX_DESC_CMD_L4T_EOFT_EOF_NI;
  	case FC_EOF_A:
  		return I40E_TX_DESC_CMD_L4T_EOFT_EOF_A;
  	default:
  		/* Supported valid eof shall be already checked by
  		 * calling i40e_fcoe_eof_is_supported() first,
  		 * therefore this default case shall never hit.
  		 */
  		WARN_ON(1);
  		return -EINVAL;
  	}
  }
  
  /**
   * i40e_fcoe_xid_is_valid - returns true if the exchange id is valid
   * @xid: the exchange id
   **/
  static inline bool i40e_fcoe_xid_is_valid(u16 xid)
  {
  	return (xid != FC_XID_UNKNOWN) && (xid < I40E_FCOE_DDP_MAX);
  }
  
  /**
   * i40e_fcoe_ddp_unmap - unmap the mapped sglist associated
   * @pf: pointer to PF
   * @ddp: sw DDP context
   *
   * Unmap the scatter-gather list associated with the given SW DDP context
   *
   * Returns: data length already ddp-ed in bytes
   *
   **/
  static inline void i40e_fcoe_ddp_unmap(struct i40e_pf *pf,
  				       struct i40e_fcoe_ddp *ddp)
  {
  	if (test_and_set_bit(__I40E_FCOE_DDP_UNMAPPED, &ddp->flags))
  		return;
  
  	if (ddp->sgl) {
  		dma_unmap_sg(&pf->pdev->dev, ddp->sgl, ddp->sgc,
  			     DMA_FROM_DEVICE);
  		ddp->sgl = NULL;
  		ddp->sgc = 0;
  	}
  
  	if (ddp->pool) {
  		dma_pool_free(ddp->pool, ddp->udl, ddp->udp);
  		ddp->pool = NULL;
  	}
  }
  
  /**
   * i40e_fcoe_ddp_clear - clear the given SW DDP context
   * @ddp - SW DDP context
   **/
  static inline void i40e_fcoe_ddp_clear(struct i40e_fcoe_ddp *ddp)
  {
  	memset(ddp, 0, sizeof(struct i40e_fcoe_ddp));
  	ddp->xid = FC_XID_UNKNOWN;
  	ddp->flags = __I40E_FCOE_DDP_NONE;
  }
  
  /**
   * i40e_fcoe_progid_is_fcoe - check if the prog_id is for FCoE
   * @id: the prog id for the programming status Rx descriptor write-back
   **/
  static inline bool i40e_fcoe_progid_is_fcoe(u8 id)
  {
  	return (id == I40E_RX_PROG_STATUS_DESC_FCOE_CTXT_PROG_STATUS) ||
  	       (id == I40E_RX_PROG_STATUS_DESC_FCOE_CTXT_INVL_STATUS);
  }
  
  /**
   * i40e_fcoe_fc_get_xid - get xid from the frame header
   * @fh: the fc frame header
   *
   * In case the incoming frame's exchange is originated from
   * the initiator, then received frame's exchange id is ANDed
   * with fc_cpu_mask bits to get the same cpu on which exchange
   * was originated, otherwise just use the current cpu.
   *
   * Returns ox_id if exchange originator, rx_id if responder
   **/
  static inline u16 i40e_fcoe_fc_get_xid(struct fc_frame_header *fh)
  {
  	u32 f_ctl = ntoh24(fh->fh_f_ctl);
  
  	return (f_ctl & FC_FC_EX_CTX) ?
  		be16_to_cpu(fh->fh_ox_id) :
  		be16_to_cpu(fh->fh_rx_id);
  }
  
  /**
   * i40e_fcoe_fc_frame_header - get fc frame header from skb
   * @skb: packet
   *
   * This checks if there is a VLAN header and returns the data
   * pointer to the start of the fc_frame_header.
   *
   * Returns pointer to the fc_frame_header
   **/
  static inline struct fc_frame_header *i40e_fcoe_fc_frame_header(
  	struct sk_buff *skb)
  {
  	void *fh = skb->data + sizeof(struct fcoe_hdr);
  
  	if (eth_hdr(skb)->h_proto == htons(ETH_P_8021Q))
  		fh += sizeof(struct vlan_hdr);
  
  	return (struct fc_frame_header *)fh;
  }
  
  /**
   * i40e_fcoe_ddp_put - release the DDP context for a given exchange id
   * @netdev: the corresponding net_device
   * @xid: the exchange id that corresponding DDP context will be released
   *
   * This is the implementation of net_device_ops.ndo_fcoe_ddp_done
   * and it is expected to be called by ULD, i.e., FCP layer of libfc
   * to release the corresponding ddp context when the I/O is done.
   *
   * Returns : data length already ddp-ed in bytes
   **/
  static int i40e_fcoe_ddp_put(struct net_device *netdev, u16 xid)
  {
  	struct i40e_netdev_priv *np = netdev_priv(netdev);
  	struct i40e_pf *pf = np->vsi->back;
  	struct i40e_fcoe *fcoe = &pf->fcoe;
  	int len = 0;
  	struct i40e_fcoe_ddp *ddp = &fcoe->ddp[xid];
  
  	if (!fcoe || !ddp)
  		goto out;
  
  	if (test_bit(__I40E_FCOE_DDP_DONE, &ddp->flags))
  		len = ddp->len;
  	i40e_fcoe_ddp_unmap(pf, ddp);
  out:
  	return len;
  }
  
  /**
   * i40e_fcoe_sw_init - sets up the HW for FCoE
   * @pf: pointer to PF
   **/
  void i40e_init_pf_fcoe(struct i40e_pf *pf)
  {
  	struct i40e_hw *hw = &pf->hw;
  	u32 val;
  
  	pf->flags &= ~I40E_FLAG_FCOE_ENABLED;
  	pf->num_fcoe_qps = 0;
  	pf->fcoe_hmc_cntx_num = 0;
  	pf->fcoe_hmc_filt_num = 0;
  
  	if (!pf->hw.func_caps.fcoe) {
  		dev_dbg(&pf->pdev->dev, "FCoE capability is disabled
  ");
  		return;
  	}
  
  	if (!pf->hw.func_caps.dcb) {
  		dev_warn(&pf->pdev->dev,
  			 "Hardware is not DCB capable not enabling FCoE.
  ");
  		return;
  	}
  
  	/* enable FCoE hash filter */
  	val = rd32(hw, I40E_PFQF_HENA(1));
  	val |= BIT(I40E_FILTER_PCTYPE_FCOE_OX - 32);
  	val |= BIT(I40E_FILTER_PCTYPE_FCOE_RX - 32);
  	val &= I40E_PFQF_HENA_PTYPE_ENA_MASK;
  	wr32(hw, I40E_PFQF_HENA(1), val);
  
  	/* enable flag */
  	pf->flags |= I40E_FLAG_FCOE_ENABLED;
  	pf->num_fcoe_qps = I40E_DEFAULT_FCOE;
  
  	/* Reserve 4K DDP contexts and 20K filter size for FCoE */
  	pf->fcoe_hmc_cntx_num = BIT(I40E_DMA_CNTX_SIZE_4K) *
  				I40E_DMA_CNTX_BASE_SIZE;
  	pf->fcoe_hmc_filt_num = pf->fcoe_hmc_cntx_num +
  				BIT(I40E_HASH_FILTER_SIZE_16K) *
  				I40E_HASH_FILTER_BASE_SIZE;
  
  	/* FCoE object: max 16K filter buckets and 4K DMA contexts */
  	pf->filter_settings.fcoe_filt_num = I40E_HASH_FILTER_SIZE_16K;
  	pf->filter_settings.fcoe_cntx_num = I40E_DMA_CNTX_SIZE_4K;
  
  	/* Setup max frame with FCoE_MTU plus L2 overheads */
  	val = rd32(hw, I40E_GLFCOE_RCTL);
  	val &= ~I40E_GLFCOE_RCTL_MAX_SIZE_MASK;
  	val |= ((FCOE_MTU + ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN)
  		 << I40E_GLFCOE_RCTL_MAX_SIZE_SHIFT);
  	wr32(hw, I40E_GLFCOE_RCTL, val);
  
  	dev_info(&pf->pdev->dev, "FCoE is supported.
  ");
  }
  
  /**
   * i40e_get_fcoe_tc_map - Return TC map for FCoE APP
   * @pf: pointer to PF
   *
   **/
  u8 i40e_get_fcoe_tc_map(struct i40e_pf *pf)
  {
  	struct i40e_dcb_app_priority_table app;
  	struct i40e_hw *hw = &pf->hw;
  	u8 enabled_tc = 0;
  	u8 tc, i;
  	/* Get the FCoE APP TLV */
  	struct i40e_dcbx_config *dcbcfg = &hw->local_dcbx_config;
  
  	for (i = 0; i < dcbcfg->numapps; i++) {
  		app = dcbcfg->app[i];
  		if (app.selector == IEEE_8021QAZ_APP_SEL_ETHERTYPE &&
  		    app.protocolid == ETH_P_FCOE) {
  			tc = dcbcfg->etscfg.prioritytable[app.priority];
  			enabled_tc |= BIT(tc);
  			break;
  		}
  	}
  
  	/* TC0 if there is no TC defined for FCoE APP TLV */
  	enabled_tc = enabled_tc ? enabled_tc : 0x1;
  
  	return enabled_tc;
  }
  
  /**
   * i40e_fcoe_vsi_init - prepares the VSI context for creating a FCoE VSI
   * @vsi: pointer to the associated VSI struct
   * @ctxt: pointer to the associated VSI context to be passed to HW
   *
   * Returns 0 on success or < 0 on error
   **/
  int i40e_fcoe_vsi_init(struct i40e_vsi *vsi, struct i40e_vsi_context *ctxt)
  {
  	struct i40e_aqc_vsi_properties_data *info = &ctxt->info;
  	struct i40e_pf *pf = vsi->back;
  	struct i40e_hw *hw = &pf->hw;
  	u8 enabled_tc = 0;
  
  	if (!(pf->flags & I40E_FLAG_FCOE_ENABLED)) {
  		dev_err(&pf->pdev->dev,
  			"FCoE is not enabled for this device
  ");
  		return -EPERM;
  	}
  
  	/* initialize the hardware for FCoE */
  	ctxt->pf_num = hw->pf_id;
  	ctxt->vf_num = 0;
  	ctxt->uplink_seid = vsi->uplink_seid;
  	ctxt->connection_type = I40E_AQ_VSI_CONN_TYPE_NORMAL;
  	ctxt->flags = I40E_AQ_VSI_TYPE_PF;
  
  	/* FCoE VSI would need the following sections */
  	info->valid_sections |= cpu_to_le16(I40E_AQ_VSI_PROP_QUEUE_OPT_VALID);
  
  	/* FCoE VSI does not need these sections */
  	info->valid_sections &= cpu_to_le16(~(I40E_AQ_VSI_PROP_SECURITY_VALID |
  					    I40E_AQ_VSI_PROP_VLAN_VALID |
  					    I40E_AQ_VSI_PROP_CAS_PV_VALID |
  					    I40E_AQ_VSI_PROP_INGRESS_UP_VALID |
  					    I40E_AQ_VSI_PROP_EGRESS_UP_VALID));
  
  	if (i40e_is_vsi_uplink_mode_veb(vsi)) {
  		info->valid_sections |=
  				cpu_to_le16(I40E_AQ_VSI_PROP_SWITCH_VALID);
  		info->switch_id =
  				cpu_to_le16(I40E_AQ_VSI_SW_ID_FLAG_ALLOW_LB);
  	}
  	enabled_tc = i40e_get_fcoe_tc_map(pf);
  	i40e_vsi_setup_queue_map(vsi, ctxt, enabled_tc, true);
  
  	/* set up queue option section: only enable FCoE */
  	info->queueing_opt_flags = I40E_AQ_VSI_QUE_OPT_FCOE_ENA;
  
  	return 0;
  }
  
  /**
   * i40e_fcoe_enable - this is the implementation of ndo_fcoe_enable,
   * indicating the upper FCoE protocol stack is ready to use FCoE
   * offload features.
   *
   * @netdev: pointer to the netdev that FCoE is created on
   *
   * Returns 0 on success
   *
   * in RTNL
   *
   **/
  int i40e_fcoe_enable(struct net_device *netdev)
  {
  	struct i40e_netdev_priv *np = netdev_priv(netdev);
  	struct i40e_vsi *vsi = np->vsi;
  	struct i40e_pf *pf = vsi->back;
  	struct i40e_fcoe *fcoe = &pf->fcoe;
  
  	if (!(pf->flags & I40E_FLAG_FCOE_ENABLED)) {
  		netdev_err(netdev, "HW does not support FCoE.
  ");
  		return -ENODEV;
  	}
  
  	if (vsi->type != I40E_VSI_FCOE) {
  		netdev_err(netdev, "interface does not support FCoE.
  ");
  		return -EBUSY;
  	}
  
  	atomic_inc(&fcoe->refcnt);
  
  	return 0;
  }
  
  /**
   * i40e_fcoe_disable- disables FCoE for upper FCoE protocol stack.
   * @dev: pointer to the netdev that FCoE is created on
   *
   * Returns 0 on success
   *
   **/
  int i40e_fcoe_disable(struct net_device *netdev)
  {
  	struct i40e_netdev_priv *np = netdev_priv(netdev);
  	struct i40e_vsi *vsi = np->vsi;
  	struct i40e_pf *pf = vsi->back;
  	struct i40e_fcoe *fcoe = &pf->fcoe;
  
  	if (!(pf->flags & I40E_FLAG_FCOE_ENABLED)) {
  		netdev_err(netdev, "device does not support FCoE
  ");
  		return -ENODEV;
  	}
  	if (vsi->type != I40E_VSI_FCOE)
  		return -EBUSY;
  
  	if (!atomic_dec_and_test(&fcoe->refcnt))
  		return -EINVAL;
  
  	netdev_info(netdev, "FCoE disabled
  ");
  
  	return 0;
  }
  
  /**
   * i40e_fcoe_dma_pool_free - free the per cpu pool for FCoE DDP
   * @fcoe: the FCoE sw object
   * @dev: the device that the pool is associated with
   * @cpu: the cpu for this pool
   *
   **/
  static void i40e_fcoe_dma_pool_free(struct i40e_fcoe *fcoe,
  				    struct device *dev,
  				    unsigned int cpu)
  {
  	struct i40e_fcoe_ddp_pool *ddp_pool;
  
  	ddp_pool = per_cpu_ptr(fcoe->ddp_pool, cpu);
  	if (!ddp_pool->pool) {
  		dev_warn(dev, "DDP pool already freed for cpu %d
  ", cpu);
  		return;
  	}
  	dma_pool_destroy(ddp_pool->pool);
  	ddp_pool->pool = NULL;
  }
  
  /**
   * i40e_fcoe_dma_pool_create - per cpu pool for FCoE DDP
   * @fcoe: the FCoE sw object
   * @dev: the device that the pool is associated with
   * @cpu: the cpu for this pool
   *
   * Returns 0 on successful or non zero on failure
   *
   **/
  static int i40e_fcoe_dma_pool_create(struct i40e_fcoe *fcoe,
  				     struct device *dev,
  				     unsigned int cpu)
  {
  	struct i40e_fcoe_ddp_pool *ddp_pool;
  	struct dma_pool *pool;
  	char pool_name[32];
  
  	ddp_pool = per_cpu_ptr(fcoe->ddp_pool, cpu);
  	if (ddp_pool && ddp_pool->pool) {
  		dev_warn(dev, "DDP pool already allocated for cpu %d
  ", cpu);
  		return 0;
  	}
  	snprintf(pool_name, sizeof(pool_name), "i40e_fcoe_ddp_%d", cpu);
  	pool = dma_pool_create(pool_name, dev, I40E_FCOE_DDP_PTR_MAX,
  			       I40E_FCOE_DDP_PTR_ALIGN, PAGE_SIZE);
  	if (!pool) {
  		dev_err(dev, "dma_pool_create %s failed
  ", pool_name);
  		return -ENOMEM;
  	}
  	ddp_pool->pool = pool;
  	return 0;
  }
  
  /**
   * i40e_fcoe_free_ddp_resources - release FCoE DDP resources
   * @vsi: the vsi FCoE is associated with
   *
   **/
  void i40e_fcoe_free_ddp_resources(struct i40e_vsi *vsi)
  {
  	struct i40e_pf *pf = vsi->back;
  	struct i40e_fcoe *fcoe = &pf->fcoe;
  	int cpu, i;
  
  	/* do nothing if not FCoE VSI */
  	if (vsi->type != I40E_VSI_FCOE)
  		return;
  
  	/* do nothing if no DDP pools were allocated */
  	if (!fcoe->ddp_pool)
  		return;
  
  	for (i = 0; i < I40E_FCOE_DDP_MAX; i++)
  		i40e_fcoe_ddp_put(vsi->netdev, i);
  
  	for_each_possible_cpu(cpu)
  		i40e_fcoe_dma_pool_free(fcoe, &pf->pdev->dev, cpu);
  
  	free_percpu(fcoe->ddp_pool);
  	fcoe->ddp_pool = NULL;
  
  	netdev_info(vsi->netdev, "VSI %d,%d FCoE DDP resources released
  ",
  		    vsi->id, vsi->seid);
  }
  
  /**
   * i40e_fcoe_setup_ddp_resources - allocate per cpu DDP resources
   * @vsi: the VSI FCoE is associated with
   *
   * Returns 0 on successful or non zero on failure
   *
   **/
  int i40e_fcoe_setup_ddp_resources(struct i40e_vsi *vsi)
  {
  	struct i40e_pf *pf = vsi->back;
  	struct device *dev = &pf->pdev->dev;
  	struct i40e_fcoe *fcoe = &pf->fcoe;
  	unsigned int cpu;
  	int i;
  
  	if (vsi->type != I40E_VSI_FCOE)
  		return -ENODEV;
  
  	/* do nothing if no DDP pools were allocated */
  	if (fcoe->ddp_pool)
  		return -EEXIST;
  
  	/* allocate per CPU memory to track DDP pools */
  	fcoe->ddp_pool = alloc_percpu(struct i40e_fcoe_ddp_pool);
  	if (!fcoe->ddp_pool) {
  		dev_err(&pf->pdev->dev, "failed to allocate percpu DDP
  ");
  		return -ENOMEM;
  	}
  
  	/* allocate pci pool for each cpu */
  	for_each_possible_cpu(cpu) {
  		if (!i40e_fcoe_dma_pool_create(fcoe, dev, cpu))
  			continue;
  
  		dev_err(dev, "failed to alloc DDP pool on cpu:%d
  ", cpu);
  		i40e_fcoe_free_ddp_resources(vsi);
  		return -ENOMEM;
  	}
  
  	/* initialize the sw context */
  	for (i = 0; i < I40E_FCOE_DDP_MAX; i++)
  		i40e_fcoe_ddp_clear(&fcoe->ddp[i]);
  
  	netdev_info(vsi->netdev, "VSI %d,%d FCoE DDP resources allocated
  ",
  		    vsi->id, vsi->seid);
  
  	return 0;
  }
  
  /**
   * i40e_fcoe_handle_status - check the Programming Status for FCoE
   * @rx_ring: the Rx ring for this descriptor
   * @rx_desc: the Rx descriptor for Programming Status, not a packet descriptor.
   *
   * Check if this is the Rx Programming Status descriptor write-back for FCoE.
   * This is used to verify if the context/filter programming or invalidation
   * requested by SW to the HW is successful or not and take actions accordingly.
   **/
  void i40e_fcoe_handle_status(struct i40e_ring *rx_ring,
  			     union i40e_rx_desc *rx_desc, u8 prog_id)
  {
  	struct i40e_pf *pf = rx_ring->vsi->back;
  	struct i40e_fcoe *fcoe = &pf->fcoe;
  	struct i40e_fcoe_ddp *ddp;
  	u32 error;
  	u16 xid;
  	u64 qw;
  
  	/* we only care for FCoE here */
  	if (!i40e_fcoe_progid_is_fcoe(prog_id))
  		return;
  
  	xid = le32_to_cpu(rx_desc->wb.qword0.hi_dword.fcoe_param) &
  	      (I40E_FCOE_DDP_MAX - 1);
  
  	if (!i40e_fcoe_xid_is_valid(xid))
  		return;
  
  	ddp = &fcoe->ddp[xid];
  	WARN_ON(xid != ddp->xid);
  
  	qw = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
  	error = (qw & I40E_RX_PROG_STATUS_DESC_QW1_ERROR_MASK) >>
  		I40E_RX_PROG_STATUS_DESC_QW1_ERROR_SHIFT;
  
  	/* DDP context programming status: failure or success */
  	if (prog_id == I40E_RX_PROG_STATUS_DESC_FCOE_CTXT_PROG_STATUS) {
  		if (I40E_RX_PROG_FCOE_ERROR_TBL_FULL(error)) {
  			dev_err(&pf->pdev->dev, "xid %x ddp->xid %x TABLE FULL
  ",
  				xid, ddp->xid);
  			ddp->prerr |= I40E_RX_PROG_FCOE_ERROR_TBL_FULL_BIT;
  		}
  		if (I40E_RX_PROG_FCOE_ERROR_CONFLICT(error)) {
  			dev_err(&pf->pdev->dev, "xid %x ddp->xid %x CONFLICT
  ",
  				xid, ddp->xid);
  			ddp->prerr |= I40E_RX_PROG_FCOE_ERROR_CONFLICT_BIT;
  		}
  	}
  
  	/* DDP context invalidation status: failure or success */
  	if (prog_id == I40E_RX_PROG_STATUS_DESC_FCOE_CTXT_INVL_STATUS) {
  		if (I40E_RX_PROG_FCOE_ERROR_INVLFAIL(error)) {
  			dev_err(&pf->pdev->dev, "xid %x ddp->xid %x INVALIDATION FAILURE
  ",
  				xid, ddp->xid);
  			ddp->prerr |= I40E_RX_PROG_FCOE_ERROR_INVLFAIL_BIT;
  		}
  		/* clear the flag so we can retry invalidation */
  		clear_bit(__I40E_FCOE_DDP_ABORTED, &ddp->flags);
  	}
  
  	/* unmap DMA */
  	i40e_fcoe_ddp_unmap(pf, ddp);
  	i40e_fcoe_ddp_clear(ddp);
  }
  
  /**
   * i40e_fcoe_handle_offload - check ddp status and mark it done
   * @adapter: i40e adapter
   * @rx_desc: advanced rx descriptor
   * @skb: the skb holding the received data
   *
   * This checks ddp status.
   *
   * Returns : < 0 indicates an error or not a FCOE ddp, 0 indicates
   * not passing the skb to ULD, > 0 indicates is the length of data
   * being ddped.
   *
   **/
  int i40e_fcoe_handle_offload(struct i40e_ring *rx_ring,
  			     union i40e_rx_desc *rx_desc,
  			     struct sk_buff *skb)
  {
  	struct i40e_pf *pf = rx_ring->vsi->back;
  	struct i40e_fcoe *fcoe = &pf->fcoe;
  	struct fc_frame_header *fh = NULL;
  	struct i40e_fcoe_ddp *ddp = NULL;
  	u32 status, fltstat;
  	u32 error, fcerr;
  	int rc = -EINVAL;
  	u16 ptype;
  	u16 xid;
  	u64 qw;
  
  	/* check this rxd is for programming status */
  	qw = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
  	/* packet descriptor, check packet type */
  	ptype = (qw & I40E_RXD_QW1_PTYPE_MASK) >> I40E_RXD_QW1_PTYPE_SHIFT;
  	if (!i40e_rx_is_fcoe(ptype))
  		goto out_no_ddp;
  
  	error = (qw & I40E_RXD_QW1_ERROR_MASK) >> I40E_RXD_QW1_ERROR_SHIFT;
  	fcerr = (error >> I40E_RX_DESC_ERROR_L3L4E_SHIFT) &
  		 I40E_RX_DESC_FCOE_ERROR_MASK;
  
  	/* check stateless offload error */
  	if (unlikely(fcerr == I40E_RX_DESC_ERROR_L3L4E_PROT)) {
  		dev_err(&pf->pdev->dev, "Protocol Error
  ");
  		skb->ip_summed = CHECKSUM_NONE;
  	} else {
  		skb->ip_summed = CHECKSUM_UNNECESSARY;
  	}
  
  	/* check hw status on ddp */
  	status = (qw & I40E_RXD_QW1_STATUS_MASK) >> I40E_RXD_QW1_STATUS_SHIFT;
  	fltstat = (status >> I40E_RX_DESC_STATUS_FLTSTAT_SHIFT) &
  		   I40E_RX_DESC_FLTSTAT_FCMASK;
  
  	/* now we are ready to check DDP */
  	fh = i40e_fcoe_fc_frame_header(skb);
  	xid = i40e_fcoe_fc_get_xid(fh);
  	if (!i40e_fcoe_xid_is_valid(xid))
  		goto out_no_ddp;
  
  	/* non DDP normal receive, return to the protocol stack */
  	if (fltstat == I40E_RX_DESC_FLTSTAT_NOMTCH)
  		goto out_no_ddp;
  
  	/* do we have a sw ddp context setup ? */
  	ddp = &fcoe->ddp[xid];
  	if (!ddp->sgl)
  		goto out_no_ddp;
  
  	/* fetch xid from hw rxd wb, which should match up the sw ctxt */
  	xid = le16_to_cpu(rx_desc->wb.qword0.lo_dword.mirr_fcoe.fcoe_ctx_id);
  	if (ddp->xid != xid) {
  		dev_err(&pf->pdev->dev, "xid 0x%x does not match ctx_xid 0x%x
  ",
  			ddp->xid, xid);
  		goto out_put_ddp;
  	}
  
  	/* the same exchange has already errored out */
  	if (ddp->fcerr) {
  		dev_err(&pf->pdev->dev, "xid 0x%x fcerr 0x%x reported fcer 0x%x
  ",
  			xid, ddp->fcerr, fcerr);
  		goto out_put_ddp;
  	}
  
  	/* fcoe param is valid by now with correct DDPed length */
  	ddp->len = le32_to_cpu(rx_desc->wb.qword0.hi_dword.fcoe_param);
  	ddp->fcerr = fcerr;
  	/* header posting only, useful only for target mode and debugging */
  	if (fltstat == I40E_RX_DESC_FLTSTAT_DDP) {
  		/* For target mode, we get header of the last packet but it
  		 * does not have the FCoE trailer field, i.e., CRC and EOF
  		 * Ordered Set since they are offloaded by the HW, so fill
  		 * it up correspondingly to allow the packet to pass through
  		 * to the upper protocol stack.
  		 */
  		u32 f_ctl = ntoh24(fh->fh_f_ctl);
  
  		if ((f_ctl & FC_FC_END_SEQ) &&
  		    (fh->fh_r_ctl == FC_RCTL_DD_SOL_DATA)) {
  			struct fcoe_crc_eof *crc = NULL;
  
  			crc = (struct fcoe_crc_eof *)skb_put(skb, sizeof(*crc));
  			crc->fcoe_eof = FC_EOF_T;
  		} else {
  			/* otherwise, drop the header only frame */
  			rc = 0;
  			goto out_no_ddp;
  		}
  	}
  
  out_put_ddp:
  	/* either we got RSP or we have an error, unmap DMA in both cases */
  	i40e_fcoe_ddp_unmap(pf, ddp);
  	if (ddp->len && !ddp->fcerr) {
  		int pkts;
  
  		rc = ddp->len;
  		i40e_fcoe_ddp_clear(ddp);
  		ddp->len = rc;
  		pkts = DIV_ROUND_UP(rc, 2048);
  		rx_ring->stats.bytes += rc;
  		rx_ring->stats.packets += pkts;
  		rx_ring->q_vector->rx.total_bytes += rc;
  		rx_ring->q_vector->rx.total_packets += pkts;
  		set_bit(__I40E_FCOE_DDP_DONE, &ddp->flags);
  	}
  
  out_no_ddp:
  	return rc;
  }
  
  /**
   * i40e_fcoe_ddp_setup - called to set up ddp context
   * @netdev: the corresponding net_device
   * @xid: the exchange id requesting ddp
   * @sgl: the scatter-gather list for this request
   * @sgc: the number of scatter-gather items
   * @target_mode: indicates this is a DDP request for target
   *
   * Returns : 1 for success and 0 for no DDP on this I/O
   **/
  static int i40e_fcoe_ddp_setup(struct net_device *netdev, u16 xid,
  			       struct scatterlist *sgl, unsigned int sgc,
  			       int target_mode)
  {
  	static const unsigned int bufflen = I40E_FCOE_DDP_BUF_MIN;
  	struct i40e_netdev_priv *np = netdev_priv(netdev);
  	struct i40e_fcoe_ddp_pool *ddp_pool;
  	struct i40e_pf *pf = np->vsi->back;
  	struct i40e_fcoe *fcoe = &pf->fcoe;
  	unsigned int i, j, dmacount;
  	struct i40e_fcoe_ddp *ddp;
  	unsigned int firstoff = 0;
  	unsigned int thisoff = 0;
  	unsigned int thislen = 0;
  	struct scatterlist *sg;
  	dma_addr_t addr = 0;
  	unsigned int len;
  
  	if (xid >= I40E_FCOE_DDP_MAX) {
  		dev_warn(&pf->pdev->dev, "xid=0x%x out-of-range
  ", xid);
  		return 0;
  	}
  
  	/* no DDP if we are already down or resetting */
  	if (test_bit(__I40E_DOWN, &pf->state) ||
  	    test_bit(__I40E_NEEDS_RESTART, &pf->state)) {
  		dev_info(&pf->pdev->dev, "xid=0x%x device in reset/down
  ",
  			 xid);
  		return 0;
  	}
  
  	ddp = &fcoe->ddp[xid];
  	if (ddp->sgl) {
  		dev_info(&pf->pdev->dev, "xid 0x%x w/ non-null sgl=%p nents=%d
  ",
  			 xid, ddp->sgl, ddp->sgc);
  		return 0;
  	}
  	i40e_fcoe_ddp_clear(ddp);
  
  	if (!fcoe->ddp_pool) {
  		dev_info(&pf->pdev->dev, "No DDP pool, xid 0x%x
  ", xid);
  		return 0;
  	}
  
  	ddp_pool = per_cpu_ptr(fcoe->ddp_pool, get_cpu());
  	if (!ddp_pool->pool) {
  		dev_info(&pf->pdev->dev, "No percpu ddp pool, xid 0x%x
  ", xid);
  		goto out_noddp;
  	}
  
  	/* setup dma from scsi command sgl */
  	dmacount = dma_map_sg(&pf->pdev->dev, sgl, sgc, DMA_FROM_DEVICE);
  	if (dmacount == 0) {
  		dev_info(&pf->pdev->dev, "dma_map_sg for sgl %p, sgc %d failed
  ",
  			 sgl, sgc);
  		goto out_noddp_unmap;
  	}
  
  	/* alloc the udl from our ddp pool */
  	ddp->udl = dma_pool_alloc(ddp_pool->pool, GFP_ATOMIC, &ddp->udp);
  	if (!ddp->udl) {
  		dev_info(&pf->pdev->dev,
  			 "Failed allocated ddp context, xid 0x%x
  ", xid);
  		goto out_noddp_unmap;
  	}
  
  	j = 0;
  	ddp->len = 0;
  	for_each_sg(sgl, sg, dmacount, i) {
  		addr = sg_dma_address(sg);
  		len = sg_dma_len(sg);
  		ddp->len += len;
  		while (len) {
  			/* max number of buffers allowed in one DDP context */
  			if (j >= I40E_FCOE_DDP_BUFFCNT_MAX) {
  				dev_info(&pf->pdev->dev,
  					 "xid=%x:%d,%d,%d:addr=%llx not enough descriptors
  ",
  					 xid, i, j, dmacount, (u64)addr);
  				goto out_noddp_free;
  			}
  
  			/* get the offset of length of current buffer */
  			thisoff = addr & ((dma_addr_t)bufflen - 1);
  			thislen = min_t(unsigned int, (bufflen - thisoff), len);
  			/* all but the 1st buffer (j == 0)
  			 * must be aligned on bufflen
  			 */
  			if ((j != 0) && (thisoff))
  				goto out_noddp_free;
  
  			/* all but the last buffer
  			 * ((i == (dmacount - 1)) && (thislen == len))
  			 * must end at bufflen
  			 */
  			if (((i != (dmacount - 1)) || (thislen != len)) &&
  			    ((thislen + thisoff) != bufflen))
  				goto out_noddp_free;
  
  			ddp->udl[j] = (u64)(addr - thisoff);
  			/* only the first buffer may have none-zero offset */
  			if (j == 0)
  				firstoff = thisoff;
  			len -= thislen;
  			addr += thislen;
  			j++;
  		}
  	}
  	/* only the last buffer may have non-full bufflen */
  	ddp->lastsize = thisoff + thislen;
  	ddp->firstoff = firstoff;
  	ddp->list_len = j;
  	ddp->pool = ddp_pool->pool;
  	ddp->sgl = sgl;
  	ddp->sgc = sgc;
  	ddp->xid = xid;
  	if (target_mode)
  		set_bit(__I40E_FCOE_DDP_TARGET, &ddp->flags);
  	set_bit(__I40E_FCOE_DDP_INITALIZED, &ddp->flags);
  
  	put_cpu();
  	return 1; /* Success */
  
  out_noddp_free:
  	dma_pool_free(ddp->pool, ddp->udl, ddp->udp);
  	i40e_fcoe_ddp_clear(ddp);
  
  out_noddp_unmap:
  	dma_unmap_sg(&pf->pdev->dev, sgl, sgc, DMA_FROM_DEVICE);
  out_noddp:
  	put_cpu();
  	return 0;
  }
  
  /**
   * i40e_fcoe_ddp_get - called to set up ddp context in initiator mode
   * @netdev: the corresponding net_device
   * @xid: the exchange id requesting ddp
   * @sgl: the scatter-gather list for this request
   * @sgc: the number of scatter-gather items
   *
   * This is the implementation of net_device_ops.ndo_fcoe_ddp_setup
   * and is expected to be called from ULD, e.g., FCP layer of libfc
   * to set up ddp for the corresponding xid of the given sglist for
   * the corresponding I/O.
   *
   * Returns : 1 for success and 0 for no ddp
   **/
  static int i40e_fcoe_ddp_get(struct net_device *netdev, u16 xid,
  			     struct scatterlist *sgl, unsigned int sgc)
  {
  	return i40e_fcoe_ddp_setup(netdev, xid, sgl, sgc, 0);
  }
  
  /**
   * i40e_fcoe_ddp_target - called to set up ddp context in target mode
   * @netdev: the corresponding net_device
   * @xid: the exchange id requesting ddp
   * @sgl: the scatter-gather list for this request
   * @sgc: the number of scatter-gather items
   *
   * This is the implementation of net_device_ops.ndo_fcoe_ddp_target
   * and is expected to be called from ULD, e.g., FCP layer of libfc
   * to set up ddp for the corresponding xid of the given sglist for
   * the corresponding I/O. The DDP in target mode is a write I/O request
   * from the initiator.
   *
   * Returns : 1 for success and 0 for no ddp
   **/
  static int i40e_fcoe_ddp_target(struct net_device *netdev, u16 xid,
  				struct scatterlist *sgl, unsigned int sgc)
  {
  	return i40e_fcoe_ddp_setup(netdev, xid, sgl, sgc, 1);
  }
  
  /**
   * i40e_fcoe_program_ddp - programs the HW DDP related descriptors
   * @tx_ring: transmit ring for this packet
   * @skb:     the packet to be sent out
   * @sof: the SOF to indicate class of service
   *
   * Determine if it is READ/WRITE command, and finds out if there is
   * a matching SW DDP context for this command. DDP is applicable
   * only in case of READ if initiator or WRITE in case of
   * responder (via checking XFER_RDY).
   *
   * Note: caller checks sof and ddp sw context
   *
   * Returns : none
   *
   **/
  static void i40e_fcoe_program_ddp(struct i40e_ring *tx_ring,
  				  struct sk_buff *skb,
  				  struct i40e_fcoe_ddp *ddp, u8 sof)
  {
  	struct i40e_fcoe_filter_context_desc *filter_desc = NULL;
  	struct i40e_fcoe_queue_context_desc *queue_desc = NULL;
  	struct i40e_fcoe_ddp_context_desc *ddp_desc = NULL;
  	struct i40e_pf *pf = tx_ring->vsi->back;
  	u16 i = tx_ring->next_to_use;
  	struct fc_frame_header *fh;
  	u64 flags_rsvd_lanq = 0;
  	bool target_mode;
  
  	/* check if abort is still pending */
  	if (test_bit(__I40E_FCOE_DDP_ABORTED, &ddp->flags)) {
  		dev_warn(&pf->pdev->dev,
  			 "DDP abort is still pending xid:%hx and ddp->flags:%lx:
  ",
  			 ddp->xid, ddp->flags);
  		return;
  	}
  
  	/* set the flag to indicate this is programmed */
  	if (test_and_set_bit(__I40E_FCOE_DDP_PROGRAMMED, &ddp->flags)) {
  		dev_warn(&pf->pdev->dev,
  			 "DDP is already programmed for xid:%hx and ddp->flags:%lx:
  ",
  			 ddp->xid, ddp->flags);
  		return;
  	}
  
  	/* Prepare the DDP context descriptor */
  	ddp_desc = I40E_DDP_CONTEXT_DESC(tx_ring, i);
  	i++;
  	if (i == tx_ring->count)
  		i = 0;
  
  	ddp_desc->type_cmd_foff_lsize =
  				cpu_to_le64(I40E_TX_DESC_DTYPE_DDP_CTX	|
  				((u64)I40E_FCOE_DDP_CTX_DESC_BSIZE_4K  <<
  				I40E_FCOE_DDP_CTX_QW1_CMD_SHIFT)	|
  				((u64)ddp->firstoff		       <<
  				I40E_FCOE_DDP_CTX_QW1_FOFF_SHIFT)	|
  				((u64)ddp->lastsize		       <<
  				I40E_FCOE_DDP_CTX_QW1_LSIZE_SHIFT));
  	ddp_desc->rsvd = cpu_to_le64(0);
  
  	/* target mode needs last packet in the sequence  */
  	target_mode = test_bit(__I40E_FCOE_DDP_TARGET, &ddp->flags);
  	if (target_mode)
  		ddp_desc->type_cmd_foff_lsize |=
  			cpu_to_le64(I40E_FCOE_DDP_CTX_DESC_LASTSEQH);
  
  	/* Prepare queue_context descriptor */
  	queue_desc = I40E_QUEUE_CONTEXT_DESC(tx_ring, i++);
  	if (i == tx_ring->count)
  		i = 0;
  	queue_desc->dmaindx_fbase = cpu_to_le64(ddp->xid | ((u64)ddp->udp));
  	queue_desc->flen_tph = cpu_to_le64(ddp->list_len |
  				((u64)(I40E_FCOE_QUEUE_CTX_DESC_TPHRDESC |
  				I40E_FCOE_QUEUE_CTX_DESC_TPHDATA) <<
  				I40E_FCOE_QUEUE_CTX_QW1_TPH_SHIFT));
  
  	/* Prepare filter_context_desc */
  	filter_desc = I40E_FILTER_CONTEXT_DESC(tx_ring, i);
  	i++;
  	if (i == tx_ring->count)
  		i = 0;
  
  	fh = (struct fc_frame_header *)skb_transport_header(skb);
  	filter_desc->param = cpu_to_le32(ntohl(fh->fh_parm_offset));
  	filter_desc->seqn = cpu_to_le16(ntohs(fh->fh_seq_cnt));
  	filter_desc->rsvd_dmaindx = cpu_to_le16(ddp->xid <<
  				I40E_FCOE_FILTER_CTX_QW0_DMAINDX_SHIFT);
  
  	flags_rsvd_lanq = I40E_FCOE_FILTER_CTX_DESC_CTYP_DDP;
  	flags_rsvd_lanq |= (u64)(target_mode ?
  			I40E_FCOE_FILTER_CTX_DESC_ENODE_RSP :
  			I40E_FCOE_FILTER_CTX_DESC_ENODE_INIT);
  
  	flags_rsvd_lanq |= (u64)((sof == FC_SOF_I2 || sof == FC_SOF_N2) ?
  			I40E_FCOE_FILTER_CTX_DESC_FC_CLASS2 :
  			I40E_FCOE_FILTER_CTX_DESC_FC_CLASS3);
  
  	flags_rsvd_lanq |= ((u64)skb->queue_mapping <<
  				I40E_FCOE_FILTER_CTX_QW1_LANQINDX_SHIFT);
  	filter_desc->flags_rsvd_lanq = cpu_to_le64(flags_rsvd_lanq);
  
  	/* By this time, all offload related descriptors has been programmed */
  	tx_ring->next_to_use = i;
  }
  
  /**
   * i40e_fcoe_invalidate_ddp - invalidates DDP in case of abort
   * @tx_ring: transmit ring for this packet
   * @skb: the packet associated w/ this DDP invalidation, i.e., ABTS
   * @ddp: the SW DDP context for this DDP
   *
   * Programs the Tx context descriptor to do DDP invalidation.
   **/
  static void i40e_fcoe_invalidate_ddp(struct i40e_ring *tx_ring,
  				     struct sk_buff *skb,
  				     struct i40e_fcoe_ddp *ddp)
  {
  	struct i40e_tx_context_desc *context_desc;
  	int i;
  
  	if (test_and_set_bit(__I40E_FCOE_DDP_ABORTED, &ddp->flags))
  		return;
  
  	i = tx_ring->next_to_use;
  	context_desc = I40E_TX_CTXTDESC(tx_ring, i);
  	i++;
  	if (i == tx_ring->count)
  		i = 0;
  
  	context_desc->tunneling_params = cpu_to_le32(0);
  	context_desc->l2tag2 = cpu_to_le16(0);
  	context_desc->rsvd = cpu_to_le16(0);
  	context_desc->type_cmd_tso_mss = cpu_to_le64(
  		I40E_TX_DESC_DTYPE_FCOE_CTX |
  		(I40E_FCOE_TX_CTX_DESC_OPCODE_DDP_CTX_INVL <<
  		I40E_TXD_CTX_QW1_CMD_SHIFT) |
  		(I40E_FCOE_TX_CTX_DESC_OPCODE_SINGLE_SEND <<
  		I40E_TXD_CTX_QW1_CMD_SHIFT));
  	tx_ring->next_to_use = i;
  }
  
  /**
   * i40e_fcoe_handle_ddp - check we should setup or invalidate DDP
   * @tx_ring: transmit ring for this packet
   * @skb: the packet to be sent out
   * @sof: the SOF to indicate class of service
   *
   * Determine if it is ABTS/READ/XFER_RDY, and finds out if there is
   * a matching SW DDP context for this command. DDP is applicable
   * only in case of READ if initiator or WRITE in case of
   * responder (via checking XFER_RDY). In case this is an ABTS, send
   * just invalidate the context.
   **/
  static void i40e_fcoe_handle_ddp(struct i40e_ring *tx_ring,
  				 struct sk_buff *skb, u8 sof)
  {
  	struct i40e_pf *pf = tx_ring->vsi->back;
  	struct i40e_fcoe *fcoe = &pf->fcoe;
  	struct fc_frame_header *fh;
  	struct i40e_fcoe_ddp *ddp;
  	u32 f_ctl;
  	u8 r_ctl;
  	u16 xid;
  
  	fh = (struct fc_frame_header *)skb_transport_header(skb);
  	f_ctl = ntoh24(fh->fh_f_ctl);
  	r_ctl = fh->fh_r_ctl;
  	ddp = NULL;
  
  	if ((r_ctl == FC_RCTL_DD_DATA_DESC) && (f_ctl & FC_FC_EX_CTX)) {
  		/* exchange responder? if so, XFER_RDY for write */
  		xid = ntohs(fh->fh_rx_id);
  		if (i40e_fcoe_xid_is_valid(xid)) {
  			ddp = &fcoe->ddp[xid];
  			if ((ddp->xid == xid) &&
  			    (test_bit(__I40E_FCOE_DDP_TARGET, &ddp->flags)))
  				i40e_fcoe_program_ddp(tx_ring, skb, ddp, sof);
  		}
  	} else if (r_ctl == FC_RCTL_DD_UNSOL_CMD) {
  		/* exchange originator, check READ cmd */
  		xid = ntohs(fh->fh_ox_id);
  		if (i40e_fcoe_xid_is_valid(xid)) {
  			ddp = &fcoe->ddp[xid];
  			if ((ddp->xid == xid) &&
  			    (!test_bit(__I40E_FCOE_DDP_TARGET, &ddp->flags)))
  				i40e_fcoe_program_ddp(tx_ring, skb, ddp, sof);
  		}
  	} else if (r_ctl == FC_RCTL_BA_ABTS) {
  		/* exchange originator, check ABTS */
  		xid = ntohs(fh->fh_ox_id);
  		if (i40e_fcoe_xid_is_valid(xid)) {
  			ddp = &fcoe->ddp[xid];
  			if ((ddp->xid == xid) &&
  			    (!test_bit(__I40E_FCOE_DDP_TARGET, &ddp->flags)))
  				i40e_fcoe_invalidate_ddp(tx_ring, skb, ddp);
  		}
  	}
  }
  
  /**
   * i40e_fcoe_tso - set up FCoE TSO
   * @tx_ring:  ring to send buffer on
   * @skb:      send buffer
   * @tx_flags: collected send information
   * @hdr_len:  the tso header length
   * @sof: the SOF to indicate class of service
   *
   * Note must already have sof checked to be either class 2 or class 3 before
   * calling this function.
   *
   * Returns 1 to indicate sequence segmentation offload is properly setup
   * or returns 0 to indicate no tso is needed, otherwise returns error
   * code to drop the frame.
   **/
  static int i40e_fcoe_tso(struct i40e_ring *tx_ring,
  			 struct sk_buff *skb,
  			 u32 tx_flags, u8 *hdr_len, u8 sof)
  {
  	struct i40e_tx_context_desc *context_desc;
  	u32 cd_type, cd_cmd, cd_tso_len, cd_mss;
  	struct fc_frame_header *fh;
  	u64 cd_type_cmd_tso_mss;
  
  	/* must match gso type as FCoE */
  	if (!skb_is_gso(skb))
  		return 0;
  
  	/* is it the expected gso type for FCoE ?*/
  	if (skb_shinfo(skb)->gso_type != SKB_GSO_FCOE) {
  		netdev_err(skb->dev,
  			   "wrong gso type %d:expecting SKB_GSO_FCOE
  ",
  			   skb_shinfo(skb)->gso_type);
  		return -EINVAL;
  	}
  
  	/* header and trailer are inserted by hw */
  	*hdr_len = skb_transport_offset(skb) + sizeof(struct fc_frame_header) +
  		   sizeof(struct fcoe_crc_eof);
  
  	/* check sof to decide a class 2 or 3 TSO */
  	if (likely(i40e_fcoe_sof_is_class3(sof)))
  		cd_cmd = I40E_FCOE_TX_CTX_DESC_OPCODE_TSO_FC_CLASS3;
  	else
  		cd_cmd = I40E_FCOE_TX_CTX_DESC_OPCODE_TSO_FC_CLASS2;
  
  	/* param field valid? */
  	fh = (struct fc_frame_header *)skb_transport_header(skb);
  	if (fh->fh_f_ctl[2] & FC_FC_REL_OFF)
  		cd_cmd |= I40E_FCOE_TX_CTX_DESC_RELOFF;
  
  	/* fill the field values */
  	cd_type = I40E_TX_DESC_DTYPE_FCOE_CTX;
  	cd_tso_len = skb->len - *hdr_len;
  	cd_mss = skb_shinfo(skb)->gso_size;
  	cd_type_cmd_tso_mss =
  		((u64)cd_type  << I40E_TXD_CTX_QW1_DTYPE_SHIFT)     |
  		((u64)cd_cmd     << I40E_TXD_CTX_QW1_CMD_SHIFT)	    |
  		((u64)cd_tso_len << I40E_TXD_CTX_QW1_TSO_LEN_SHIFT) |
  		((u64)cd_mss     << I40E_TXD_CTX_QW1_MSS_SHIFT);
  
  	/* grab the next descriptor */
  	context_desc = I40E_TX_CTXTDESC(tx_ring, tx_ring->next_to_use);
  	tx_ring->next_to_use++;
  	if (tx_ring->next_to_use == tx_ring->count)
  		tx_ring->next_to_use = 0;
  
  	context_desc->tunneling_params = 0;
  	context_desc->l2tag2 = cpu_to_le16((tx_flags & I40E_TX_FLAGS_VLAN_MASK)
  					    >> I40E_TX_FLAGS_VLAN_SHIFT);
  	context_desc->type_cmd_tso_mss = cpu_to_le64(cd_type_cmd_tso_mss);
  
  	return 1;
  }
  
  /**
   * i40e_fcoe_tx_map - build the tx descriptor
   * @tx_ring:  ring to send buffer on
   * @skb:      send buffer
   * @first:    first buffer info buffer to use
   * @tx_flags: collected send information
   * @hdr_len:  ptr to the size of the packet header
   * @eof:      the frame eof value
   *
   * Note, for FCoE, sof and eof are already checked
   **/
  static void i40e_fcoe_tx_map(struct i40e_ring *tx_ring,
  			     struct sk_buff *skb,
  			     struct i40e_tx_buffer *first,
  			     u32 tx_flags, u8 hdr_len, u8 eof)
  {
  	u32 td_offset = 0;
  	u32 td_cmd = 0;
  	u32 maclen;
  
  	/* insert CRC */
  	td_cmd = I40E_TX_DESC_CMD_ICRC;
  
  	/* setup MACLEN */
  	maclen = skb_network_offset(skb);
  	if (tx_flags & I40E_TX_FLAGS_SW_VLAN)
  		maclen += sizeof(struct vlan_hdr);
  
  	if (skb->protocol == htons(ETH_P_FCOE)) {
  		/* for FCoE, maclen should exclude ether type */
  		maclen -= 2;
  		/* setup type as FCoE and EOF insertion */
  		td_cmd |= (I40E_TX_DESC_CMD_FCOET | i40e_fcoe_ctxt_eof(eof));
  		/* setup FCoELEN and FCLEN */
  		td_offset |= ((((sizeof(struct fcoe_hdr) + 2) >> 2) <<
  				I40E_TX_DESC_LENGTH_IPLEN_SHIFT) |
  			      ((sizeof(struct fc_frame_header) >> 2) <<
  				I40E_TX_DESC_LENGTH_L4_FC_LEN_SHIFT));
  		/* trim to exclude trailer */
  		pskb_trim(skb, skb->len - sizeof(struct fcoe_crc_eof));
  	}
  
  	/* MACLEN is ether header length in words not bytes */
  	td_offset |= (maclen >> 1) << I40E_TX_DESC_LENGTH_MACLEN_SHIFT;
  
  	i40e_tx_map(tx_ring, skb, first, tx_flags, hdr_len, td_cmd, td_offset);
  }
  
  /**
   * i40e_fcoe_set_skb_header - adjust skb header point for FIP/FCoE/FC
   * @skb: the skb to be adjusted
   *
   * Returns true if this skb is a FCoE/FIP or VLAN carried FCoE/FIP and then
   * adjusts the skb header pointers correspondingly. Otherwise, returns false.
   **/
  static inline int i40e_fcoe_set_skb_header(struct sk_buff *skb)
  {
  	__be16 protocol = skb->protocol;
  
  	skb_reset_mac_header(skb);
  	skb->mac_len = sizeof(struct ethhdr);
  	if (protocol == htons(ETH_P_8021Q)) {
  		struct vlan_ethhdr *veth = (struct vlan_ethhdr *)eth_hdr(skb);
  
  		protocol = veth->h_vlan_encapsulated_proto;
  		skb->mac_len += sizeof(struct vlan_hdr);
  	}
  
  	/* FCoE or FIP only */
  	if ((protocol != htons(ETH_P_FIP)) &&
  	    (protocol != htons(ETH_P_FCOE)))
  		return -EINVAL;
  
  	/* set header to L2 of FCoE/FIP */
  	skb_set_network_header(skb, skb->mac_len);
  	if (protocol == htons(ETH_P_FIP))
  		return 0;
  
  	/* set header to L3 of FC */
  	skb_set_transport_header(skb, skb->mac_len + sizeof(struct fcoe_hdr));
  	return 0;
  }
  
  /**
   * i40e_fcoe_xmit_frame - transmit buffer
   * @skb:     send buffer
   * @netdev:  the fcoe netdev
   *
   * Returns 0 if sent, else an error code
   **/
  static netdev_tx_t i40e_fcoe_xmit_frame(struct sk_buff *skb,
  					struct net_device *netdev)
  {
  	struct i40e_netdev_priv *np = netdev_priv(skb->dev);
  	struct i40e_vsi *vsi = np->vsi;
  	struct i40e_ring *tx_ring = vsi->tx_rings[skb->queue_mapping];
  	struct i40e_tx_buffer *first;
  	u32 tx_flags = 0;
  	u8 hdr_len = 0;
  	u8 sof = 0;
  	u8 eof = 0;
  	int fso;
  
  	if (i40e_fcoe_set_skb_header(skb))
  		goto out_drop;
  
  	if (!i40e_xmit_descriptor_count(skb, tx_ring))
  		return NETDEV_TX_BUSY;
  
  	/* prepare the xmit flags */
  	if (i40e_tx_prepare_vlan_flags(skb, tx_ring, &tx_flags))
  		goto out_drop;
  
  	/* record the location of the first descriptor for this packet */
  	first = &tx_ring->tx_bi[tx_ring->next_to_use];
  
  	/* FIP is a regular L2 traffic w/o offload */
  	if (skb->protocol == htons(ETH_P_FIP))
  		goto out_send;
  
  	/* check sof and eof, only supports FC Class 2 or 3 */
  	if (i40e_fcoe_fc_sof(skb, &sof) || i40e_fcoe_fc_eof(skb, &eof)) {
  		netdev_err(netdev, "SOF/EOF error:%02x - %02x
  ", sof, eof);
  		goto out_drop;
  	}
  
  	/* always do FCCRC for FCoE */
  	tx_flags |= I40E_TX_FLAGS_FCCRC;
  
  	/* check we should do sequence offload */
  	fso = i40e_fcoe_tso(tx_ring, skb, tx_flags, &hdr_len, sof);
  	if (fso < 0)
  		goto out_drop;
  	else if (fso)
  		tx_flags |= I40E_TX_FLAGS_FSO;
  	else
  		i40e_fcoe_handle_ddp(tx_ring, skb, sof);
  
  out_send:
  	/* send out the packet */
  	i40e_fcoe_tx_map(tx_ring, skb, first, tx_flags, hdr_len, eof);
  
  	i40e_maybe_stop_tx(tx_ring, DESC_NEEDED);
  	return NETDEV_TX_OK;
  
  out_drop:
  	dev_kfree_skb_any(skb);
  	return NETDEV_TX_OK;
  }
  
  /**
   * i40e_fcoe_change_mtu - NDO callback to change the Maximum Transfer Unit
   * @netdev: network interface device structure
   * @new_mtu: new value for maximum frame size
   *
   * Returns error as operation not permitted
   *
   **/
  static int i40e_fcoe_change_mtu(struct net_device *netdev, int new_mtu)
  {
  	netdev_warn(netdev, "MTU change is not supported on FCoE interfaces
  ");
  	return -EPERM;
  }
  
  /**
   * i40e_fcoe_set_features - set the netdev feature flags
   * @netdev: ptr to the netdev being adjusted
   * @features: the feature set that the stack is suggesting
   *
   **/
  static int i40e_fcoe_set_features(struct net_device *netdev,
  				  netdev_features_t features)
  {
  	struct i40e_netdev_priv *np = netdev_priv(netdev);
  	struct i40e_vsi *vsi = np->vsi;
  
  	if (features & NETIF_F_HW_VLAN_CTAG_RX)
  		i40e_vlan_stripping_enable(vsi);
  	else
  		i40e_vlan_stripping_disable(vsi);
  
  	return 0;
  }
  
  static const struct net_device_ops i40e_fcoe_netdev_ops = {
  	.ndo_open		= i40e_open,
  	.ndo_stop		= i40e_close,
  	.ndo_get_stats64	= i40e_get_netdev_stats_struct,
  	.ndo_set_rx_mode	= i40e_set_rx_mode,
  	.ndo_validate_addr	= eth_validate_addr,
  	.ndo_set_mac_address	= i40e_set_mac,
  	.ndo_change_mtu		= i40e_fcoe_change_mtu,
  	.ndo_do_ioctl		= i40e_ioctl,
  	.ndo_tx_timeout		= i40e_tx_timeout,
  	.ndo_vlan_rx_add_vid	= i40e_vlan_rx_add_vid,
  	.ndo_vlan_rx_kill_vid	= i40e_vlan_rx_kill_vid,
  	.ndo_setup_tc		= i40e_setup_tc,
  
  #ifdef CONFIG_NET_POLL_CONTROLLER
  	.ndo_poll_controller	= i40e_netpoll,
  #endif
  	.ndo_start_xmit		= i40e_fcoe_xmit_frame,
  	.ndo_fcoe_enable	= i40e_fcoe_enable,
  	.ndo_fcoe_disable	= i40e_fcoe_disable,
  	.ndo_fcoe_ddp_setup	= i40e_fcoe_ddp_get,
  	.ndo_fcoe_ddp_done	= i40e_fcoe_ddp_put,
  	.ndo_fcoe_ddp_target	= i40e_fcoe_ddp_target,
  	.ndo_set_features	= i40e_fcoe_set_features,
  };
  
  /* fcoe network device type */
  static struct device_type fcoe_netdev_type = {
  	.name = "fcoe",
  };
  
  /**
   * i40e_fcoe_config_netdev - prepares the VSI context for creating a FCoE VSI
   * @vsi: pointer to the associated VSI struct
   * @ctxt: pointer to the associated VSI context to be passed to HW
   *
   * Returns 0 on success or < 0 on error
   **/
  void i40e_fcoe_config_netdev(struct net_device *netdev, struct i40e_vsi *vsi)
  {
  	struct i40e_hw *hw = &vsi->back->hw;
  	struct i40e_pf *pf = vsi->back;
  
  	if (vsi->type != I40E_VSI_FCOE)
  		return;
  
  	netdev->features = (NETIF_F_HW_VLAN_CTAG_TX |
  			    NETIF_F_HW_VLAN_CTAG_RX |
  			    NETIF_F_HW_VLAN_CTAG_FILTER);
  
  	netdev->vlan_features = netdev->features;
  	netdev->vlan_features &= ~(NETIF_F_HW_VLAN_CTAG_TX |
  				   NETIF_F_HW_VLAN_CTAG_RX |
  				   NETIF_F_HW_VLAN_CTAG_FILTER);
  	netdev->fcoe_ddp_xid = I40E_FCOE_DDP_MAX - 1;
  	netdev->features |= NETIF_F_ALL_FCOE;
  	netdev->vlan_features |= NETIF_F_ALL_FCOE;
  	netdev->hw_features |= netdev->features;
  	netdev->priv_flags |= IFF_UNICAST_FLT;
  	netdev->priv_flags |= IFF_SUPP_NOFCS;
  
  	strlcpy(netdev->name, "fcoe%d", IFNAMSIZ-1);
  	netdev->mtu = FCOE_MTU;
  	SET_NETDEV_DEV(netdev, &pf->pdev->dev);
  	SET_NETDEV_DEVTYPE(netdev, &fcoe_netdev_type);
  	/* set different dev_port value 1 for FCoE netdev than the default
  	 * zero dev_port value for PF netdev, this helps biosdevname user
  	 * tool to differentiate them correctly while both attached to the
  	 * same PCI function.
  	 */
  	netdev->dev_port = 1;
  	spin_lock_bh(&vsi->mac_filter_list_lock);
  	i40e_add_filter(vsi, hw->mac.san_addr, 0, false, false);
  	i40e_add_filter(vsi, (u8[6]) FC_FCOE_FLOGI_MAC, 0, false, false);
  	i40e_add_filter(vsi, FIP_ALL_FCOE_MACS, 0, false, false);
  	i40e_add_filter(vsi, FIP_ALL_ENODE_MACS, 0, false, false);
  	spin_unlock_bh(&vsi->mac_filter_list_lock);
  
  	/* use san mac */
  	ether_addr_copy(netdev->dev_addr, hw->mac.san_addr);
  	ether_addr_copy(netdev->perm_addr, hw->mac.san_addr);
  	/* fcoe netdev ops */
  	netdev->netdev_ops = &i40e_fcoe_netdev_ops;
  }
  
  /**
   * i40e_fcoe_vsi_setup - allocate and set up FCoE VSI
   * @pf: the PF that VSI is associated with
   *
   **/
  void i40e_fcoe_vsi_setup(struct i40e_pf *pf)
  {
  	struct i40e_vsi *vsi;
  	u16 seid;
  	int i;
  
  	if (!(pf->flags & I40E_FLAG_FCOE_ENABLED))
  		return;
  
  	BUG_ON(!pf->vsi[pf->lan_vsi]);
  
  	for (i = 0; i < pf->num_alloc_vsi; i++) {
  		vsi = pf->vsi[i];
  		if (vsi && vsi->type == I40E_VSI_FCOE) {
  			dev_warn(&pf->pdev->dev,
  				 "FCoE VSI already created
  ");
  			return;
  		}
  	}
  
  	seid = pf->vsi[pf->lan_vsi]->seid;
  	vsi = i40e_vsi_setup(pf, I40E_VSI_FCOE, seid, 0);
  	if (vsi) {
  		dev_dbg(&pf->pdev->dev,
  			"Successfully created FCoE VSI seid %d id %d uplink_seid %d PF seid %d
  ",
  			vsi->seid, vsi->id, vsi->uplink_seid, seid);
  	} else {
  		dev_info(&pf->pdev->dev, "Failed to create FCoE VSI
  ");
  	}
  }