Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[mirror_ubuntu-artful-kernel.git] / drivers / net / ethernet / intel / i40e / i40e_fcoe.c

/*******************************************************************************
 *
 * Intel Ethernet Controller XL710 Family Linux Driver
 * Copyright(c) 2013 - 2014 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_fip - returns true if the rx packet type is FIP
 * @ptype: the packet type field from rx descriptor write-back
 **/
static inline bool i40e_rx_is_fip(u16 ptype)
{
        return ptype == I40E_RX_PTYPE_L2_FIP_PAY2;
}

/**
 * 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.
 **/
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:
                /* FIXME: still returns 0 */
                pr_err("Unrecognized EOF %x\n", eof);
                return 0;
        }
}

/**
 * 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
 *
 * Returns 0 if FCoE is supported otherwise the error code
 **/
int 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_info(&pf->pdev->dev, "FCoE capability is disabled\n");
                return 0;
        }

        if (!pf->hw.func_caps.dcb) {
                dev_warn(&pf->pdev->dev,
                         "Hardware is not DCB capable not enabling FCoE.\n");
                return 0;
        }

        /* enable FCoE hash filter */
        val = rd32(hw, I40E_PFQF_HENA(1));
        val |= 1 << (I40E_FILTER_PCTYPE_FCOE_OX - 32);
        val |= 1 << (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 = (1 << I40E_DMA_CNTX_SIZE_4K) *
                                 I40E_DMA_CNTX_BASE_SIZE;
        pf->fcoe_hmc_filt_num = pf->fcoe_hmc_cntx_num +
                                (1 << 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.\n");
        return 0;
}

/**
 * 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_ieee_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 |= (1 << 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\n");
                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 = 0x1;
        ctxt->flags = I40E_AQ_VSI_TYPE_PF;

        /* FCoE VSI would need the following sections */
        info->valid_sections |= cpu_to_le16(I40E_AQ_VSI_PROP_SWITCH_VALID |
                                            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));

        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.\n");
                return -ENODEV;
        }

        if (vsi->type != I40E_VSI_FCOE) {
                netdev_err(netdev, "interface does not support FCoE.\n");
                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\n");
                return -ENODEV;
        }
        if (vsi->type != I40E_VSI_FCOE)
                return -EBUSY;

        if (!atomic_dec_and_test(&fcoe->refcnt))
                return -EINVAL;

        netdev_info(netdev, "FCoE disabled\n");

        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\n", 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\n", 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\n", 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\n",
                    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\n");
                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\n", 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\n",
                    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\n",
                                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\n",
                                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\n",
                                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\n");
                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\n",
                        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\n",
                        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\n", 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\n",
                         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\n",
                         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\n", 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\n", 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\n",
                         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\n", 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\n",
                                         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:\n",
                         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:\n",
                         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\n",
                           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;

        return 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\n", 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\n");
        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,
};

/**
 * 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);
        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);
        i40e_add_filter(vsi, FIP_ALL_VN2VN_MACS, 0, false, false);
        i40e_add_filter(vsi, FIP_ALL_P2P_MACS, 0, false, false);

        /* 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\n");
                        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\n",
                        vsi->seid, vsi->id, vsi->uplink_seid, seid);
        } else {
                dev_info(&pf->pdev->dev, "Failed to create FCoE VSI\n");
        }
}