/*
 * Copyright(c) 2015-2017 Intel Corporation.
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that 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.
 *
 * BSD LICENSE
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  - Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  - Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  - Neither the name of Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <linux/spinlock.h>
#include <linux/pci.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/prefetch.h>
#include <rdma/ib_verbs.h>

#include "hfi.h"
#include "trace.h"
#include "qp.h"
#include "sdma.h"
#include "debugfs.h"
#include "vnic.h"

#undef pr_fmt
#define pr_fmt(fmt) DRIVER_NAME ": " fmt

/*
 * The size has to be longer than this string, so we can append
 * board/chip information to it in the initialization code.
 */
const char ib_hfi1_version[] = HFI1_DRIVER_VERSION "\n";

DEFINE_SPINLOCK(hfi1_devs_lock);
LIST_HEAD(hfi1_dev_list);
DEFINE_MUTEX(hfi1_mutex);       /* general driver use */

unsigned int hfi1_max_mtu = HFI1_DEFAULT_MAX_MTU;
module_param_named(max_mtu, hfi1_max_mtu, uint, S_IRUGO);
MODULE_PARM_DESC(max_mtu, "Set max MTU bytes, default is " __stringify(
                 HFI1_DEFAULT_MAX_MTU));

unsigned int hfi1_cu = 1;
module_param_named(cu, hfi1_cu, uint, S_IRUGO);
MODULE_PARM_DESC(cu, "Credit return units");

unsigned long hfi1_cap_mask = HFI1_CAP_MASK_DEFAULT;
static int hfi1_caps_set(const char *val, const struct kernel_param *kp);
static int hfi1_caps_get(char *buffer, const struct kernel_param *kp);
static const struct kernel_param_ops cap_ops = {
        .set = hfi1_caps_set,
        .get = hfi1_caps_get
};
module_param_cb(cap_mask, &cap_ops, &hfi1_cap_mask, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(cap_mask, "Bit mask of enabled/disabled HW features");

MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("Intel Omni-Path Architecture driver");

/*
 * MAX_PKT_RCV is the max # if packets processed per receive interrupt.
 */
#define MAX_PKT_RECV 64
/*
 * MAX_PKT_THREAD_RCV is the max # of packets processed before
 * the qp_wait_list queue is flushed.
 */
#define MAX_PKT_RECV_THREAD (MAX_PKT_RECV * 4)
#define EGR_HEAD_UPDATE_THRESHOLD 16

struct hfi1_ib_stats hfi1_stats;

static int hfi1_caps_set(const char *val, const struct kernel_param *kp)
{
        int ret = 0;
        unsigned long *cap_mask_ptr = (unsigned long *)kp->arg,
                cap_mask = *cap_mask_ptr, value, diff,
                write_mask = ((HFI1_CAP_WRITABLE_MASK << HFI1_CAP_USER_SHIFT) |
                              HFI1_CAP_WRITABLE_MASK);

        ret = kstrtoul(val, 0, &value);
        if (ret) {
                pr_warn("Invalid module parameter value for 'cap_mask'\n");
                goto done;
        }
        /* Get the changed bits (except the locked bit) */
        diff = value ^ (cap_mask & ~HFI1_CAP_LOCKED_SMASK);

        /* Remove any bits that are not allowed to change after driver load */
        if (HFI1_CAP_LOCKED() && (diff & ~write_mask)) {
                pr_warn("Ignoring non-writable capability bits %#lx\n",
                        diff & ~write_mask);
                diff &= write_mask;
        }

        /* Mask off any reserved bits */
        diff &= ~HFI1_CAP_RESERVED_MASK;
        /* Clear any previously set and changing bits */
        cap_mask &= ~diff;
        /* Update the bits with the new capability */
        cap_mask |= (value & diff);
        /* Check for any kernel/user restrictions */
        diff = (cap_mask & (HFI1_CAP_MUST_HAVE_KERN << HFI1_CAP_USER_SHIFT)) ^
                ((cap_mask & HFI1_CAP_MUST_HAVE_KERN) << HFI1_CAP_USER_SHIFT);
        cap_mask &= ~diff;
        /* Set the bitmask to the final set */
        *cap_mask_ptr = cap_mask;
done:
        return ret;
}

static int hfi1_caps_get(char *buffer, const struct kernel_param *kp)
{
        unsigned long cap_mask = *(unsigned long *)kp->arg;

        cap_mask &= ~HFI1_CAP_LOCKED_SMASK;
        cap_mask |= ((cap_mask & HFI1_CAP_K2U) << HFI1_CAP_USER_SHIFT);

        return scnprintf(buffer, PAGE_SIZE, "0x%lx", cap_mask);
}

const char *get_unit_name(int unit)
{
        static char iname[16];

        snprintf(iname, sizeof(iname), DRIVER_NAME "_%u", unit);
        return iname;
}

const char *get_card_name(struct rvt_dev_info *rdi)
{
        struct hfi1_ibdev *ibdev = container_of(rdi, struct hfi1_ibdev, rdi);
        struct hfi1_devdata *dd = container_of(ibdev,
                                               struct hfi1_devdata, verbs_dev);
        return get_unit_name(dd->unit);
}

struct pci_dev *get_pci_dev(struct rvt_dev_info *rdi)
{
        struct hfi1_ibdev *ibdev = container_of(rdi, struct hfi1_ibdev, rdi);
        struct hfi1_devdata *dd = container_of(ibdev,
                                               struct hfi1_devdata, verbs_dev);
        return dd->pcidev;
}

/*
 * Return count of units with at least one port ACTIVE.
 */
int hfi1_count_active_units(void)
{
        struct hfi1_devdata *dd;
        struct hfi1_pportdata *ppd;
        unsigned long flags;
        int pidx, nunits_active = 0;

        spin_lock_irqsave(&hfi1_devs_lock, flags);
        list_for_each_entry(dd, &hfi1_dev_list, list) {
                if (!(dd->flags & HFI1_PRESENT) || !dd->kregbase1)
                        continue;
                for (pidx = 0; pidx < dd->num_pports; ++pidx) {
                        ppd = dd->pport + pidx;
                        if (ppd->lid && ppd->linkup) {
                                nunits_active++;
                                break;
                        }
                }
        }
        spin_unlock_irqrestore(&hfi1_devs_lock, flags);
        return nunits_active;
}

/*
 * Get address of eager buffer from it's index (allocated in chunks, not
 * contiguous).
 */
static inline void *get_egrbuf(const struct hfi1_ctxtdata *rcd, u64 rhf,
                               u8 *update)
{
        u32 idx = rhf_egr_index(rhf), offset = rhf_egr_buf_offset(rhf);

        *update |= !(idx & (rcd->egrbufs.threshold - 1)) && !offset;
        return (void *)(((u64)(rcd->egrbufs.rcvtids[idx].addr)) +
                        (offset * RCV_BUF_BLOCK_SIZE));
}

static inline void *hfi1_get_header(struct hfi1_devdata *dd,
                                    __le32 *rhf_addr)
{
        u32 offset = rhf_hdrq_offset(rhf_to_cpu(rhf_addr));

        return (void *)(rhf_addr - dd->rhf_offset + offset);
}

static inline struct ib_header *hfi1_get_msgheader(struct hfi1_devdata *dd,
                                                   __le32 *rhf_addr)
{
        return (struct ib_header *)hfi1_get_header(dd, rhf_addr);
}

static inline struct hfi1_16b_header
                *hfi1_get_16B_header(struct hfi1_devdata *dd,
                                     __le32 *rhf_addr)
{
        return (struct hfi1_16b_header *)hfi1_get_header(dd, rhf_addr);
}

/*
 * Validate and encode the a given RcvArray Buffer size.
 * The function will check whether the given size falls within
 * allowed size ranges for the respective type and, optionally,
 * return the proper encoding.
 */
int hfi1_rcvbuf_validate(u32 size, u8 type, u16 *encoded)
{
        if (unlikely(!PAGE_ALIGNED(size)))
                return 0;
        if (unlikely(size < MIN_EAGER_BUFFER))
                return 0;
        if (size >
            (type == PT_EAGER ? MAX_EAGER_BUFFER : MAX_EXPECTED_BUFFER))
                return 0;
        if (encoded)
                *encoded = ilog2(size / PAGE_SIZE) + 1;
        return 1;
}

static void rcv_hdrerr(struct hfi1_ctxtdata *rcd, struct hfi1_pportdata *ppd,
                       struct hfi1_packet *packet)
{
        struct ib_header *rhdr = packet->hdr;
        u32 rte = rhf_rcv_type_err(packet->rhf);
        u32 mlid_base;
        struct hfi1_ibport *ibp = rcd_to_iport(rcd);
        struct hfi1_devdata *dd = ppd->dd;
        struct rvt_dev_info *rdi = &dd->verbs_dev.rdi;

        if (packet->rhf & (RHF_VCRC_ERR | RHF_ICRC_ERR))
                return;

        if (packet->etype == RHF_RCV_TYPE_BYPASS) {
                goto drop;
        } else {
                u8 lnh = ib_get_lnh(rhdr);

                mlid_base = be16_to_cpu(IB_MULTICAST_LID_BASE);
                if (lnh == HFI1_LRH_BTH) {
                        packet->ohdr = &rhdr->u.oth;
                } else if (lnh == HFI1_LRH_GRH) {
                        packet->ohdr = &rhdr->u.l.oth;
                        packet->grh = &rhdr->u.l.grh;
                } else {
                        goto drop;
                }
        }

        if (packet->rhf & RHF_TID_ERR) {
                /* For TIDERR and RC QPs preemptively schedule a NAK */
                u32 tlen = rhf_pkt_len(packet->rhf); /* in bytes */
                u32 dlid = ib_get_dlid(rhdr);
                u32 qp_num;

                /* Sanity check packet */
                if (tlen < 24)
                        goto drop;

                /* Check for GRH */
                if (packet->grh) {
                        u32 vtf;
                        struct ib_grh *grh = packet->grh;

                        if (grh->next_hdr != IB_GRH_NEXT_HDR)
                                goto drop;
                        vtf = be32_to_cpu(grh->version_tclass_flow);
                        if ((vtf >> IB_GRH_VERSION_SHIFT) != IB_GRH_VERSION)
                                goto drop;
                }

                /* Get the destination QP number. */
                qp_num = ib_bth_get_qpn(packet->ohdr);
                if (dlid < mlid_base) {
                        struct rvt_qp *qp;
                        unsigned long flags;

                        rcu_read_lock();
                        qp = rvt_lookup_qpn(rdi, &ibp->rvp, qp_num);
                        if (!qp) {
                                rcu_read_unlock();
                                goto drop;
                        }

                        /*
                         * Handle only RC QPs - for other QP types drop error
                         * packet.
                         */
                        spin_lock_irqsave(&qp->r_lock, flags);

                        /* Check for valid receive state. */
                        if (!(ib_rvt_state_ops[qp->state] &
                              RVT_PROCESS_RECV_OK)) {
                                ibp->rvp.n_pkt_drops++;
                        }

                        switch (qp->ibqp.qp_type) {
                        case IB_QPT_RC:
                                hfi1_rc_hdrerr(rcd, packet, qp);
                                break;
                        default:
                                /* For now don't handle any other QP types */
                                break;
                        }

                        spin_unlock_irqrestore(&qp->r_lock, flags);
                        rcu_read_unlock();
                } /* Unicast QP */
        } /* Valid packet with TIDErr */

        /* handle "RcvTypeErr" flags */
        switch (rte) {
        case RHF_RTE_ERROR_OP_CODE_ERR:
        {
                void *ebuf = NULL;
                u8 opcode;

                if (rhf_use_egr_bfr(packet->rhf))
                        ebuf = packet->ebuf;

                if (!ebuf)
                        goto drop; /* this should never happen */

                opcode = ib_bth_get_opcode(packet->ohdr);
                if (opcode == IB_OPCODE_CNP) {
                        /*
                         * Only in pre-B0 h/w is the CNP_OPCODE handled
                         * via this code path.
                         */
                        struct rvt_qp *qp = NULL;
                        u32 lqpn, rqpn;
                        u16 rlid;
                        u8 svc_type, sl, sc5;

                        sc5 = hfi1_9B_get_sc5(rhdr, packet->rhf);
                        sl = ibp->sc_to_sl[sc5];

                        lqpn = ib_bth_get_qpn(packet->ohdr);
                        rcu_read_lock();
                        qp = rvt_lookup_qpn(rdi, &ibp->rvp, lqpn);
                        if (!qp) {
                                rcu_read_unlock();
                                goto drop;
                        }

                        switch (qp->ibqp.qp_type) {
                        case IB_QPT_UD:
                                rlid = 0;
                                rqpn = 0;
                                svc_type = IB_CC_SVCTYPE_UD;
                                break;
                        case IB_QPT_UC:
                                rlid = ib_get_slid(rhdr);
                                rqpn = qp->remote_qpn;
                                svc_type = IB_CC_SVCTYPE_UC;
                                break;
                        default:
                                goto drop;
                        }

                        process_becn(ppd, sl, rlid, lqpn, rqpn, svc_type);
                        rcu_read_unlock();
                }

                packet->rhf &= ~RHF_RCV_TYPE_ERR_SMASK;
                break;
        }
        default:
                break;
        }

drop:
        return;
}

static inline void init_packet(struct hfi1_ctxtdata *rcd,
                               struct hfi1_packet *packet)
{
        packet->rsize = rcd->rcvhdrqentsize; /* words */
        packet->maxcnt = rcd->rcvhdrq_cnt * packet->rsize; /* words */
        packet->rcd = rcd;
        packet->updegr = 0;
        packet->etail = -1;
        packet->rhf_addr = get_rhf_addr(rcd);
        packet->rhf = rhf_to_cpu(packet->rhf_addr);
        packet->rhqoff = rcd->head;
        packet->numpkt = 0;
}

void hfi1_process_ecn_slowpath(struct rvt_qp *qp, struct hfi1_packet *pkt,
                               bool do_cnp)
{
        struct hfi1_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
        struct ib_other_headers *ohdr = pkt->ohdr;
        struct ib_grh *grh = pkt->grh;
        u32 rqpn = 0, bth1;
        u16 pkey, rlid, dlid = ib_get_dlid(pkt->hdr);
        u8 hdr_type, sc, svc_type;
        bool is_mcast = false;

        if (pkt->etype == RHF_RCV_TYPE_BYPASS) {
                is_mcast = hfi1_is_16B_mcast(dlid);
                pkey = hfi1_16B_get_pkey(pkt->hdr);
                sc = hfi1_16B_get_sc(pkt->hdr);
                hdr_type = HFI1_PKT_TYPE_16B;
        } else {
                is_mcast = (dlid > be16_to_cpu(IB_MULTICAST_LID_BASE)) &&
                           (dlid != be16_to_cpu(IB_LID_PERMISSIVE));
                pkey = ib_bth_get_pkey(ohdr);
                sc = hfi1_9B_get_sc5(pkt->hdr, pkt->rhf);
                hdr_type = HFI1_PKT_TYPE_9B;
        }

        switch (qp->ibqp.qp_type) {
        case IB_QPT_SMI:
        case IB_QPT_GSI:
        case IB_QPT_UD:
                rlid = ib_get_slid(pkt->hdr);
                rqpn = ib_get_sqpn(pkt->ohdr);
                svc_type = IB_CC_SVCTYPE_UD;
                break;
        case IB_QPT_UC:
                rlid = rdma_ah_get_dlid(&qp->remote_ah_attr);
                rqpn = qp->remote_qpn;
                svc_type = IB_CC_SVCTYPE_UC;
                break;
        case IB_QPT_RC:
                rlid = rdma_ah_get_dlid(&qp->remote_ah_attr);
                rqpn = qp->remote_qpn;
                svc_type = IB_CC_SVCTYPE_RC;
                break;
        default:
                return;
        }

        bth1 = be32_to_cpu(ohdr->bth[1]);
        /* Call appropriate CNP handler */
        if (do_cnp && (bth1 & IB_FECN_SMASK))
                hfi1_handle_cnp_tbl[hdr_type](ibp, qp, rqpn, pkey,
                                              dlid, rlid, sc, grh);

        if (!is_mcast && (bth1 & IB_BECN_SMASK)) {
                struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
                u32 lqpn = bth1 & RVT_QPN_MASK;
                u8 sl = ibp->sc_to_sl[sc];

                process_becn(ppd, sl, rlid, lqpn, rqpn, svc_type);
        }

}

struct ps_mdata {
        struct hfi1_ctxtdata *rcd;
        u32 rsize;
        u32 maxcnt;
        u32 ps_head;
        u32 ps_tail;
        u32 ps_seq;
};

static inline void init_ps_mdata(struct ps_mdata *mdata,
                                 struct hfi1_packet *packet)
{
        struct hfi1_ctxtdata *rcd = packet->rcd;

        mdata->rcd = rcd;
        mdata->rsize = packet->rsize;
        mdata->maxcnt = packet->maxcnt;
        mdata->ps_head = packet->rhqoff;

        if (HFI1_CAP_KGET_MASK(rcd->flags, DMA_RTAIL)) {
                mdata->ps_tail = get_rcvhdrtail(rcd);
                if (rcd->ctxt == HFI1_CTRL_CTXT)
                        mdata->ps_seq = rcd->seq_cnt;
                else
                        mdata->ps_seq = 0; /* not used with DMA_RTAIL */
        } else {
                mdata->ps_tail = 0; /* used only with DMA_RTAIL*/
                mdata->ps_seq = rcd->seq_cnt;
        }
}

static inline int ps_done(struct ps_mdata *mdata, u64 rhf,
                          struct hfi1_ctxtdata *rcd)
{
        if (HFI1_CAP_KGET_MASK(rcd->flags, DMA_RTAIL))
                return mdata->ps_head == mdata->ps_tail;
        return mdata->ps_seq != rhf_rcv_seq(rhf);
}

static inline int ps_skip(struct ps_mdata *mdata, u64 rhf,
                          struct hfi1_ctxtdata *rcd)
{
        /*
         * Control context can potentially receive an invalid rhf.
         * Drop such packets.
         */
        if ((rcd->ctxt == HFI1_CTRL_CTXT) && (mdata->ps_head != mdata->ps_tail))
                return mdata->ps_seq != rhf_rcv_seq(rhf);

        return 0;
}

static inline void update_ps_mdata(struct ps_mdata *mdata,
                                   struct hfi1_ctxtdata *rcd)
{
        mdata->ps_head += mdata->rsize;
        if (mdata->ps_head >= mdata->maxcnt)
                mdata->ps_head = 0;

        /* Control context must do seq counting */
        if (!HFI1_CAP_KGET_MASK(rcd->flags, DMA_RTAIL) ||
            (rcd->ctxt == HFI1_CTRL_CTXT)) {
                if (++mdata->ps_seq > 13)
                        mdata->ps_seq = 1;
        }
}

/*
 * prescan_rxq - search through the receive queue looking for packets
 * containing Excplicit Congestion Notifications (FECNs, or BECNs).
 * When an ECN is found, process the Congestion Notification, and toggle
 * it off.
 * This is declared as a macro to allow quick checking of the port to avoid
 * the overhead of a function call if not enabled.
 */
#define prescan_rxq(rcd, packet) \
        do { \
                if (rcd->ppd->cc_prescan) \
                        __prescan_rxq(packet); \
        } while (0)
static void __prescan_rxq(struct hfi1_packet *packet)
{
        struct hfi1_ctxtdata *rcd = packet->rcd;
        struct ps_mdata mdata;

        init_ps_mdata(&mdata, packet);

        while (1) {
                struct hfi1_devdata *dd = rcd->dd;
                struct hfi1_ibport *ibp = rcd_to_iport(rcd);
                __le32 *rhf_addr = (__le32 *)rcd->rcvhdrq + mdata.ps_head +
                                         dd->rhf_offset;
                struct rvt_qp *qp;
                struct ib_header *hdr;
                struct rvt_dev_info *rdi = &dd->verbs_dev.rdi;
                u64 rhf = rhf_to_cpu(rhf_addr);
                u32 etype = rhf_rcv_type(rhf), qpn, bth1;
                int is_ecn = 0;
                u8 lnh;

                if (ps_done(&mdata, rhf, rcd))
                        break;

                if (ps_skip(&mdata, rhf, rcd))
                        goto next;

                if (etype != RHF_RCV_TYPE_IB)
                        goto next;

                packet->hdr = hfi1_get_msgheader(dd, rhf_addr);
                hdr = packet->hdr;
                lnh = ib_get_lnh(hdr);

                if (lnh == HFI1_LRH_BTH) {
                        packet->ohdr = &hdr->u.oth;
                        packet->grh = NULL;
                } else if (lnh == HFI1_LRH_GRH) {
                        packet->ohdr = &hdr->u.l.oth;
                        packet->grh = &hdr->u.l.grh;
                } else {
                        goto next; /* just in case */
                }

                bth1 = be32_to_cpu(packet->ohdr->bth[1]);
                is_ecn = !!(bth1 & (IB_FECN_SMASK | IB_BECN_SMASK));

                if (!is_ecn)
                        goto next;

                qpn = bth1 & RVT_QPN_MASK;
                rcu_read_lock();
                qp = rvt_lookup_qpn(rdi, &ibp->rvp, qpn);

                if (!qp) {
                        rcu_read_unlock();
                        goto next;
                }

                process_ecn(qp, packet, true);
                rcu_read_unlock();

                /* turn off BECN, FECN */
                bth1 &= ~(IB_FECN_SMASK | IB_BECN_SMASK);
                packet->ohdr->bth[1] = cpu_to_be32(bth1);
next:
                update_ps_mdata(&mdata, rcd);
        }
}

static void process_rcv_qp_work(struct hfi1_ctxtdata *rcd)
{
        struct rvt_qp *qp, *nqp;

        /*
         * Iterate over all QPs waiting to respond.
         * The list won't change since the IRQ is only run on one CPU.
         */
        list_for_each_entry_safe(qp, nqp, &rcd->qp_wait_list, rspwait) {
                list_del_init(&qp->rspwait);
                if (qp->r_flags & RVT_R_RSP_NAK) {
                        qp->r_flags &= ~RVT_R_RSP_NAK;
                        hfi1_send_rc_ack(rcd, qp, 0);
                }
                if (qp->r_flags & RVT_R_RSP_SEND) {
                        unsigned long flags;

                        qp->r_flags &= ~RVT_R_RSP_SEND;
                        spin_lock_irqsave(&qp->s_lock, flags);
                        if (ib_rvt_state_ops[qp->state] &
                                        RVT_PROCESS_OR_FLUSH_SEND)
                                hfi1_schedule_send(qp);
                        spin_unlock_irqrestore(&qp->s_lock, flags);
                }
                rvt_put_qp(qp);
        }
}

static noinline int max_packet_exceeded(struct hfi1_packet *packet, int thread)
{
        if (thread) {
                if ((packet->numpkt & (MAX_PKT_RECV_THREAD - 1)) == 0)
                        /* allow defered processing */
                        process_rcv_qp_work(packet->rcd);
                cond_resched();
                return RCV_PKT_OK;
        } else {
                this_cpu_inc(*packet->rcd->dd->rcv_limit);
                return RCV_PKT_LIMIT;
        }
}

static inline int check_max_packet(struct hfi1_packet *packet, int thread)
{
        int ret = RCV_PKT_OK;

        if (unlikely((packet->numpkt & (MAX_PKT_RECV - 1)) == 0))
                ret = max_packet_exceeded(packet, thread);
        return ret;
}

static noinline int skip_rcv_packet(struct hfi1_packet *packet, int thread)
{
        int ret;

        /* Set up for the next packet */
        packet->rhqoff += packet->rsize;
        if (packet->rhqoff >= packet->maxcnt)
                packet->rhqoff = 0;

        packet->numpkt++;
        ret = check_max_packet(packet, thread);

        packet->rhf_addr = (__le32 *)packet->rcd->rcvhdrq + packet->rhqoff +
                                     packet->rcd->dd->rhf_offset;
        packet->rhf = rhf_to_cpu(packet->rhf_addr);

        return ret;
}

static inline int process_rcv_packet(struct hfi1_packet *packet, int thread)
{
        int ret;

        packet->etype = rhf_rcv_type(packet->rhf);

        /* total length */
        packet->tlen = rhf_pkt_len(packet->rhf); /* in bytes */
        /* retrieve eager buffer details */
        packet->ebuf = NULL;
        if (rhf_use_egr_bfr(packet->rhf)) {
                packet->etail = rhf_egr_index(packet->rhf);
                packet->ebuf = get_egrbuf(packet->rcd, packet->rhf,
                                 &packet->updegr);
                /*
                 * Prefetch the contents of the eager buffer.  It is
                 * OK to send a negative length to prefetch_range().
                 * The +2 is the size of the RHF.
                 */
                prefetch_range(packet->ebuf,
                               packet->tlen - ((packet->rcd->rcvhdrqentsize -
                                               (rhf_hdrq_offset(packet->rhf)
                                                + 2)) * 4));
        }

        /*
         * Call a type specific handler for the packet. We
         * should be able to trust that etype won't be beyond
         * the range of valid indexes. If so something is really
         * wrong and we can probably just let things come
         * crashing down. There is no need to eat another
         * comparison in this performance critical code.
         */
        packet->rcd->dd->rhf_rcv_function_map[packet->etype](packet);
        packet->numpkt++;

        /* Set up for the next packet */
        packet->rhqoff += packet->rsize;
        if (packet->rhqoff >= packet->maxcnt)
                packet->rhqoff = 0;

        ret = check_max_packet(packet, thread);

        packet->rhf_addr = (__le32 *)packet->rcd->rcvhdrq + packet->rhqoff +
                                      packet->rcd->dd->rhf_offset;
        packet->rhf = rhf_to_cpu(packet->rhf_addr);

        return ret;
}

static inline void process_rcv_update(int last, struct hfi1_packet *packet)
{
        /*
         * Update head regs etc., every 16 packets, if not last pkt,
         * to help prevent rcvhdrq overflows, when many packets
         * are processed and queue is nearly full.
         * Don't request an interrupt for intermediate updates.
         */
        if (!last && !(packet->numpkt & 0xf)) {
                update_usrhead(packet->rcd, packet->rhqoff, packet->updegr,
                               packet->etail, 0, 0);
                packet->updegr = 0;
        }
        packet->grh = NULL;
}

static inline void finish_packet(struct hfi1_packet *packet)
{
        /*
         * Nothing we need to free for the packet.
         *
         * The only thing we need to do is a final update and call for an
         * interrupt
         */
        update_usrhead(packet->rcd, packet->rcd->head, packet->updegr,
                       packet->etail, rcv_intr_dynamic, packet->numpkt);
}

/*
 * Handle receive interrupts when using the no dma rtail option.
 */
int handle_receive_interrupt_nodma_rtail(struct hfi1_ctxtdata *rcd, int thread)
{
        u32 seq;
        int last = RCV_PKT_OK;
        struct hfi1_packet packet;

        init_packet(rcd, &packet);
        seq = rhf_rcv_seq(packet.rhf);
        if (seq != rcd->seq_cnt) {
                last = RCV_PKT_DONE;
                goto bail;
        }

        prescan_rxq(rcd, &packet);

        while (last == RCV_PKT_OK) {
                last = process_rcv_packet(&packet, thread);
                seq = rhf_rcv_seq(packet.rhf);
                if (++rcd->seq_cnt > 13)
                        rcd->seq_cnt = 1;
                if (seq != rcd->seq_cnt)
                        last = RCV_PKT_DONE;
                process_rcv_update(last, &packet);
        }
        process_rcv_qp_work(rcd);
        rcd->head = packet.rhqoff;
bail:
        finish_packet(&packet);
        return last;
}

int handle_receive_interrupt_dma_rtail(struct hfi1_ctxtdata *rcd, int thread)
{
        u32 hdrqtail;
        int last = RCV_PKT_OK;
        struct hfi1_packet packet;

        init_packet(rcd, &packet);
        hdrqtail = get_rcvhdrtail(rcd);
        if (packet.rhqoff == hdrqtail) {
                last = RCV_PKT_DONE;
                goto bail;
        }
        smp_rmb();  /* prevent speculative reads of dma'ed hdrq */

        prescan_rxq(rcd, &packet);

        while (last == RCV_PKT_OK) {
                last = process_rcv_packet(&packet, thread);
                if (packet.rhqoff == hdrqtail)
                        last = RCV_PKT_DONE;
                process_rcv_update(last, &packet);
        }
        process_rcv_qp_work(rcd);
        rcd->head = packet.rhqoff;
bail:
        finish_packet(&packet);
        return last;
}

static inline void set_nodma_rtail(struct hfi1_devdata *dd, u16 ctxt)
{
        struct hfi1_ctxtdata *rcd;
        u16 i;

        /*
         * For dynamically allocated kernel contexts (like vnic) switch
         * interrupt handler only for that context. Otherwise, switch
         * interrupt handler for all statically allocated kernel contexts.
         */
        if (ctxt >= dd->first_dyn_alloc_ctxt) {
                rcd = hfi1_rcd_get_by_index(dd, ctxt);
                if (rcd) {
                        rcd->do_interrupt =
                                &handle_receive_interrupt_nodma_rtail;
                        hfi1_rcd_put(rcd);
                }
                return;
        }

        for (i = HFI1_CTRL_CTXT + 1; i < dd->first_dyn_alloc_ctxt; i++) {
                rcd = hfi1_rcd_get_by_index(dd, i);
                if (rcd)
                        rcd->do_interrupt =
                                &handle_receive_interrupt_nodma_rtail;
                hfi1_rcd_put(rcd);
        }
}

static inline void set_dma_rtail(struct hfi1_devdata *dd, u16 ctxt)
{
        struct hfi1_ctxtdata *rcd;
        u16 i;

        /*
         * For dynamically allocated kernel contexts (like vnic) switch
         * interrupt handler only for that context. Otherwise, switch
         * interrupt handler for all statically allocated kernel contexts.
         */
        if (ctxt >= dd->first_dyn_alloc_ctxt) {
                rcd = hfi1_rcd_get_by_index(dd, ctxt);
                if (rcd) {
                        rcd->do_interrupt =
                                &handle_receive_interrupt_dma_rtail;
                        hfi1_rcd_put(rcd);
                }
                return;
        }

        for (i = HFI1_CTRL_CTXT + 1; i < dd->first_dyn_alloc_ctxt; i++) {
                rcd = hfi1_rcd_get_by_index(dd, i);
                if (rcd)
                        rcd->do_interrupt =
                                &handle_receive_interrupt_dma_rtail;
                hfi1_rcd_put(rcd);
        }
}

void set_all_slowpath(struct hfi1_devdata *dd)
{
        struct hfi1_ctxtdata *rcd;
        u16 i;

        /* HFI1_CTRL_CTXT must always use the slow path interrupt handler */
        for (i = HFI1_CTRL_CTXT + 1; i < dd->num_rcv_contexts; i++) {
                rcd = hfi1_rcd_get_by_index(dd, i);
                if (!rcd)
                        continue;
                if ((i < dd->first_dyn_alloc_ctxt) ||
                    (rcd->sc && (rcd->sc->type == SC_KERNEL))) {
                        rcd->do_interrupt = &handle_receive_interrupt;
                }
                hfi1_rcd_put(rcd);
        }
}

static inline int set_armed_to_active(struct hfi1_ctxtdata *rcd,
                                      struct hfi1_packet *packet,
                                      struct hfi1_devdata *dd)
{
        struct work_struct *lsaw = &rcd->ppd->linkstate_active_work;
        u8 etype = rhf_rcv_type(packet->rhf);
        u8 sc = SC15_PACKET;

        if (etype == RHF_RCV_TYPE_IB) {
                struct ib_header *hdr = hfi1_get_msgheader(packet->rcd->dd,
                                                           packet->rhf_addr);
                sc = hfi1_9B_get_sc5(hdr, packet->rhf);
        } else if (etype == RHF_RCV_TYPE_BYPASS) {
                struct hfi1_16b_header *hdr = hfi1_get_16B_header(
                                                packet->rcd->dd,
                                                packet->rhf_addr);
                sc = hfi1_16B_get_sc(hdr);
        }
        if (sc != SC15_PACKET) {
                int hwstate = driver_lstate(rcd->ppd);

                if (hwstate != IB_PORT_ACTIVE) {
                        dd_dev_info(dd,
                                    "Unexpected link state %s\n",
                                    opa_lstate_name(hwstate));
                        return 0;
                }

                queue_work(rcd->ppd->link_wq, lsaw);
                return 1;
        }
        return 0;
}

/*
 * handle_receive_interrupt - receive a packet
 * @rcd: the context
 *
 * Called from interrupt handler for errors or receive interrupt.
 * This is the slow path interrupt handler.
 */
int handle_receive_interrupt(struct hfi1_ctxtdata *rcd, int thread)
{
        struct hfi1_devdata *dd = rcd->dd;
        u32 hdrqtail;
        int needset, last = RCV_PKT_OK;
        struct hfi1_packet packet;
        int skip_pkt = 0;

        /* Control context will always use the slow path interrupt handler */
        needset = (rcd->ctxt == HFI1_CTRL_CTXT) ? 0 : 1;

        init_packet(rcd, &packet);

        if (!HFI1_CAP_KGET_MASK(rcd->flags, DMA_RTAIL)) {
                u32 seq = rhf_rcv_seq(packet.rhf);

                if (seq != rcd->seq_cnt) {
                        last = RCV_PKT_DONE;
                        goto bail;
                }
                hdrqtail = 0;
        } else {
                hdrqtail = get_rcvhdrtail(rcd);
                if (packet.rhqoff == hdrqtail) {
                        last = RCV_PKT_DONE;
                        goto bail;

                }
                smp_rmb();  /* prevent speculative reads of dma'ed hdrq */

                /*
                 * Control context can potentially receive an invalid
                 * rhf. Drop such packets.
                 */
                if (rcd->ctxt == HFI1_CTRL_CTXT) {
                        u32 seq = rhf_rcv_seq(packet.rhf);

                        if (seq != rcd->seq_cnt)
                                skip_pkt = 1;
                }
        }

        prescan_rxq(rcd, &packet);

        while (last == RCV_PKT_OK) {
                if (unlikely(dd->do_drop &&
                             atomic_xchg(&dd->drop_packet, DROP_PACKET_OFF) ==
                             DROP_PACKET_ON)) {
                        dd->do_drop = 0;

                        /* On to the next packet */
                        packet.rhqoff += packet.rsize;
                        packet.rhf_addr = (__le32 *)rcd->rcvhdrq +
                                          packet.rhqoff +
                                          dd->rhf_offset;
                        packet.rhf = rhf_to_cpu(packet.rhf_addr);

                } else if (skip_pkt) {
                        last = skip_rcv_packet(&packet, thread);
                        skip_pkt = 0;
                } else {
                        /* Auto activate link on non-SC15 packet receive */
                        if (unlikely(rcd->ppd->host_link_state ==
                                     HLS_UP_ARMED) &&
                            set_armed_to_active(rcd, &packet, dd))
                                goto bail;
                        last = process_rcv_packet(&packet, thread);
                }

                if (!HFI1_CAP_KGET_MASK(rcd->flags, DMA_RTAIL)) {
                        u32 seq = rhf_rcv_seq(packet.rhf);

                        if (++rcd->seq_cnt > 13)
                                rcd->seq_cnt = 1;
                        if (seq != rcd->seq_cnt)
                                last = RCV_PKT_DONE;
                        if (needset) {
                                dd_dev_info(dd, "Switching to NO_DMA_RTAIL\n");
                                set_nodma_rtail(dd, rcd->ctxt);
                                needset = 0;
                        }
                } else {
                        if (packet.rhqoff == hdrqtail)
                                last = RCV_PKT_DONE;
                        /*
                         * Control context can potentially receive an invalid
                         * rhf. Drop such packets.
                         */
                        if (rcd->ctxt == HFI1_CTRL_CTXT) {
                                u32 seq = rhf_rcv_seq(packet.rhf);

                                if (++rcd->seq_cnt > 13)
                                        rcd->seq_cnt = 1;
                                if (!last && (seq != rcd->seq_cnt))
                                        skip_pkt = 1;
                        }

                        if (needset) {
                                dd_dev_info(dd,
                                            "Switching to DMA_RTAIL\n");
                                set_dma_rtail(dd, rcd->ctxt);
                                needset = 0;
                        }
                }

                process_rcv_update(last, &packet);
        }

        process_rcv_qp_work(rcd);
        rcd->head = packet.rhqoff;

bail:
        /*
         * Always write head at end, and setup rcv interrupt, even
         * if no packets were processed.
         */
        finish_packet(&packet);
        return last;
}

/*
 * We may discover in the interrupt that the hardware link state has
 * changed from ARMED to ACTIVE (due to the arrival of a non-SC15 packet),
 * and we need to update the driver's notion of the link state.  We cannot
 * run set_link_state from interrupt context, so we queue this function on
 * a workqueue.
 *
 * We delay the regular interrupt processing until after the state changes
 * so that the link will be in the correct state by the time any application
 * we wake up attempts to send a reply to any message it received.
 * (Subsequent receive interrupts may possibly force the wakeup before we
 * update the link state.)
 *
 * The rcd is freed in hfi1_free_ctxtdata after hfi1_postinit_cleanup invokes
 * dd->f_cleanup(dd) to disable the interrupt handler and flush workqueues,
 * so we're safe from use-after-free of the rcd.
 */
void receive_interrupt_work(struct work_struct *work)
{
        struct hfi1_pportdata *ppd = container_of(work, struct hfi1_pportdata,
                                                  linkstate_active_work);
        struct hfi1_devdata *dd = ppd->dd;
        struct hfi1_ctxtdata *rcd;
        u16 i;

        /* Received non-SC15 packet implies neighbor_normal */
        ppd->neighbor_normal = 1;
        set_link_state(ppd, HLS_UP_ACTIVE);

        /*
         * Interrupt all statically allocated kernel contexts that could
         * have had an interrupt during auto activation.
         */
        for (i = HFI1_CTRL_CTXT; i < dd->first_dyn_alloc_ctxt; i++) {
                rcd = hfi1_rcd_get_by_index(dd, i);
                if (rcd)
                        force_recv_intr(rcd);
                hfi1_rcd_put(rcd);
        }
}

/*
 * Convert a given MTU size to the on-wire MAD packet enumeration.
 * Return -1 if the size is invalid.
 */
int mtu_to_enum(u32 mtu, int default_if_bad)
{
        switch (mtu) {
        case     0: return OPA_MTU_0;
        case   256: return OPA_MTU_256;
        case   512: return OPA_MTU_512;
        case  1024: return OPA_MTU_1024;
        case  2048: return OPA_MTU_2048;
        case  4096: return OPA_MTU_4096;
        case  8192: return OPA_MTU_8192;
        case 10240: return OPA_MTU_10240;
        }
        return default_if_bad;
}

u16 enum_to_mtu(int mtu)
{
        switch (mtu) {
        case OPA_MTU_0:     return 0;
        case OPA_MTU_256:   return 256;
        case OPA_MTU_512:   return 512;
        case OPA_MTU_1024:  return 1024;
        case OPA_MTU_2048:  return 2048;
        case OPA_MTU_4096:  return 4096;
        case OPA_MTU_8192:  return 8192;
        case OPA_MTU_10240: return 10240;
        default: return 0xffff;
        }
}

/*
 * set_mtu - set the MTU
 * @ppd: the per port data
 *
 * We can handle "any" incoming size, the issue here is whether we
 * need to restrict our outgoing size.  We do not deal with what happens
 * to programs that are already running when the size changes.
 */
int set_mtu(struct hfi1_pportdata *ppd)
{
        struct hfi1_devdata *dd = ppd->dd;
        int i, drain, ret = 0, is_up = 0;

        ppd->ibmtu = 0;
        for (i = 0; i < ppd->vls_supported; i++)
                if (ppd->ibmtu < dd->vld[i].mtu)
                        ppd->ibmtu = dd->vld[i].mtu;
        ppd->ibmaxlen = ppd->ibmtu + lrh_max_header_bytes(ppd->dd);

        mutex_lock(&ppd->hls_lock);
        if (ppd->host_link_state == HLS_UP_INIT ||
            ppd->host_link_state == HLS_UP_ARMED ||
            ppd->host_link_state == HLS_UP_ACTIVE)
                is_up = 1;

        drain = !is_ax(dd) && is_up;

        if (drain)
                /*
                 * MTU is specified per-VL. To ensure that no packet gets
                 * stuck (due, e.g., to the MTU for the packet's VL being
                 * reduced), empty the per-VL FIFOs before adjusting MTU.
                 */
                ret = stop_drain_data_vls(dd);

        if (ret) {
                dd_dev_err(dd, "%s: cannot stop/drain VLs - refusing to change per-VL MTUs\n",
                           __func__);
                goto err;
        }

        hfi1_set_ib_cfg(ppd, HFI1_IB_CFG_MTU, 0);

        if (drain)
                open_fill_data_vls(dd); /* reopen all VLs */

err:
        mutex_unlock(&ppd->hls_lock);

        return ret;
}

int hfi1_set_lid(struct hfi1_pportdata *ppd, u32 lid, u8 lmc)
{
        struct hfi1_devdata *dd = ppd->dd;

        ppd->lid = lid;
        ppd->lmc = lmc;
        hfi1_set_ib_cfg(ppd, HFI1_IB_CFG_LIDLMC, 0);

        dd_dev_info(dd, "port %u: got a lid: 0x%x\n", ppd->port, lid);

        return 0;
}

void shutdown_led_override(struct hfi1_pportdata *ppd)
{
        struct hfi1_devdata *dd = ppd->dd;

        /*
         * This pairs with the memory barrier in hfi1_start_led_override to
         * ensure that we read the correct state of LED beaconing represented
         * by led_override_timer_active
         */
        smp_rmb();
        if (atomic_read(&ppd->led_override_timer_active)) {
                del_timer_sync(&ppd->led_override_timer);
                atomic_set(&ppd->led_override_timer_active, 0);
                /* Ensure the atomic_set is visible to all CPUs */
                smp_wmb();
        }

        /* Hand control of the LED to the DC for normal operation */
        write_csr(dd, DCC_CFG_LED_CNTRL, 0);
}

static void run_led_override(unsigned long opaque)
{
        struct hfi1_pportdata *ppd = (struct hfi1_pportdata *)opaque;
        struct hfi1_devdata *dd = ppd->dd;
        unsigned long timeout;
        int phase_idx;

        if (!(dd->flags & HFI1_INITTED))
                return;

        phase_idx = ppd->led_override_phase & 1;

        setextled(dd, phase_idx);

        timeout = ppd->led_override_vals[phase_idx];

        /* Set up for next phase */
        ppd->led_override_phase = !ppd->led_override_phase;

        mod_timer(&ppd->led_override_timer, jiffies + timeout);
}

/*
 * To have the LED blink in a particular pattern, provide timeon and timeoff
 * in milliseconds.
 * To turn off custom blinking and return to normal operation, use
 * shutdown_led_override()
 */
void hfi1_start_led_override(struct hfi1_pportdata *ppd, unsigned int timeon,
                             unsigned int timeoff)
{
        if (!(ppd->dd->flags & HFI1_INITTED))
                return;

        /* Convert to jiffies for direct use in timer */
        ppd->led_override_vals[0] = msecs_to_jiffies(timeoff);
        ppd->led_override_vals[1] = msecs_to_jiffies(timeon);

        /* Arbitrarily start from LED on phase */
        ppd->led_override_phase = 1;

        /*
         * If the timer has not already been started, do so. Use a "quick"
         * timeout so the handler will be called soon to look at our request.
         */
        if (!timer_pending(&ppd->led_override_timer)) {
                setup_timer(&ppd->led_override_timer, run_led_override,
                            (unsigned long)ppd);
                ppd->led_override_timer.expires = jiffies + 1;
                add_timer(&ppd->led_override_timer);
                atomic_set(&ppd->led_override_timer_active, 1);
                /* Ensure the atomic_set is visible to all CPUs */
                smp_wmb();
        }
}

/**
 * hfi1_reset_device - reset the chip if possible
 * @unit: the device to reset
 *
 * Whether or not reset is successful, we attempt to re-initialize the chip
 * (that is, much like a driver unload/reload).  We clear the INITTED flag
 * so that the various entry points will fail until we reinitialize.  For
 * now, we only allow this if no user contexts are open that use chip resources
 */
int hfi1_reset_device(int unit)
{
        int ret;
        struct hfi1_devdata *dd = hfi1_lookup(unit);
        struct hfi1_pportdata *ppd;
        int pidx;

        if (!dd) {
                ret = -ENODEV;
                goto bail;
        }

        dd_dev_info(dd, "Reset on unit %u requested\n", unit);

        if (!dd->kregbase1 || !(dd->flags & HFI1_PRESENT)) {
                dd_dev_info(dd,
                            "Invalid unit number %u or not initialized or not present\n",
                            unit);
                ret = -ENXIO;
                goto bail;
        }

        /* If there are any user/vnic contexts, we cannot reset */
        mutex_lock(&hfi1_mutex);
        if (dd->rcd)
                if (hfi1_stats.sps_ctxts) {
                        mutex_unlock(&hfi1_mutex);
                        ret = -EBUSY;
                        goto bail;
                }
        mutex_unlock(&hfi1_mutex);

        for (pidx = 0; pidx < dd->num_pports; ++pidx) {
                ppd = dd->pport + pidx;

                shutdown_led_override(ppd);
        }
        if (dd->flags & HFI1_HAS_SEND_DMA)
                sdma_exit(dd);

        hfi1_reset_cpu_counters(dd);

        ret = hfi1_init(dd, 1);

        if (ret)
                dd_dev_err(dd,
                           "Reinitialize unit %u after reset failed with %d\n",
                           unit, ret);
        else
                dd_dev_info(dd, "Reinitialized unit %u after resetting\n",
                            unit);

bail:
        return ret;
}

static inline void hfi1_setup_ib_header(struct hfi1_packet *packet)
{
        packet->hdr = (struct hfi1_ib_message_header *)
                        hfi1_get_msgheader(packet->rcd->dd,
                                           packet->rhf_addr);
        packet->hlen = (u8 *)packet->rhf_addr - (u8 *)packet->hdr;
}

static int hfi1_bypass_ingress_pkt_check(struct hfi1_packet *packet)
{
        struct hfi1_pportdata *ppd = packet->rcd->ppd;

        /* slid and dlid cannot be 0 */
        if ((!packet->slid) || (!packet->dlid))
                return -EINVAL;

        /* Compare port lid with incoming packet dlid */
        if ((!(hfi1_is_16B_mcast(packet->dlid))) &&
            (packet->dlid !=
                opa_get_lid(be32_to_cpu(OPA_LID_PERMISSIVE), 16B))) {
                if (packet->dlid != ppd->lid)
                        return -EINVAL;
        }

        /* No multicast packets with SC15 */
        if ((hfi1_is_16B_mcast(packet->dlid)) && (packet->sc == 0xF))
                return -EINVAL;

        /* Packets with permissive DLID always on SC15 */
        if ((packet->dlid == opa_get_lid(be32_to_cpu(OPA_LID_PERMISSIVE),
                                         16B)) &&
            (packet->sc != 0xF))
                return -EINVAL;

        return 0;
}

static int hfi1_setup_9B_packet(struct hfi1_packet *packet)
{
        struct hfi1_ibport *ibp = rcd_to_iport(packet->rcd);
        struct ib_header *hdr;
        u8 lnh;

        hfi1_setup_ib_header(packet);
        hdr = packet->hdr;

        lnh = ib_get_lnh(hdr);
        if (lnh == HFI1_LRH_BTH) {
                packet->ohdr = &hdr->u.oth;
                packet->grh = NULL;
        } else if (lnh == HFI1_LRH_GRH) {
                u32 vtf;

                packet->ohdr = &hdr->u.l.oth;
                packet->grh = &hdr->u.l.grh;
                if (packet->grh->next_hdr != IB_GRH_NEXT_HDR)
                        goto drop;
                vtf = be32_to_cpu(packet->grh->version_tclass_flow);
                if ((vtf >> IB_GRH_VERSION_SHIFT) != IB_GRH_VERSION)
                        goto drop;
        } else {
                goto drop;
        }

        /* Query commonly used fields from packet header */
        packet->payload = packet->ebuf;
        packet->opcode = ib_bth_get_opcode(packet->ohdr);
        packet->slid = ib_get_slid(hdr);
        packet->dlid = ib_get_dlid(hdr);
        if (unlikely((packet->dlid >= be16_to_cpu(IB_MULTICAST_LID_BASE)) &&
                     (packet->dlid != be16_to_cpu(IB_LID_PERMISSIVE))))
                packet->dlid += opa_get_mcast_base(OPA_MCAST_NR) -
                                be16_to_cpu(IB_MULTICAST_LID_BASE);
        packet->sl = ib_get_sl(hdr);
        packet->sc = hfi1_9B_get_sc5(hdr, packet->rhf);
        packet->pad = ib_bth_get_pad(packet->ohdr);
        packet->extra_byte = 0;
        packet->fecn = ib_bth_get_fecn(packet->ohdr);
        packet->becn = ib_bth_get_becn(packet->ohdr);

        return 0;
drop:
        ibp->rvp.n_pkt_drops++;
        return -EINVAL;
}

static int hfi1_setup_bypass_packet(struct hfi1_packet *packet)
{
        /*
         * Bypass packets have a different header/payload split
         * compared to an IB packet.
         * Current split is set such that 16 bytes of the actual
         * header is in the header buffer and the remining is in
         * the eager buffer. We chose 16 since hfi1 driver only
         * supports 16B bypass packets and we will be able to
         * receive the entire LRH with such a split.
         */

        struct hfi1_ctxtdata *rcd = packet->rcd;
        struct hfi1_pportdata *ppd = rcd->ppd;
        struct hfi1_ibport *ibp = &ppd->ibport_data;
        u8 l4;
        u8 grh_len;

        packet->hdr = (struct hfi1_16b_header *)
                        hfi1_get_16B_header(packet->rcd->dd,
                                            packet->rhf_addr);
        packet->hlen = (u8 *)packet->rhf_addr - (u8 *)packet->hdr;

        l4 = hfi1_16B_get_l4(packet->hdr);
        if (l4 == OPA_16B_L4_IB_LOCAL) {
                grh_len = 0;
                packet->ohdr = packet->ebuf;
                packet->grh = NULL;
        } else if (l4 == OPA_16B_L4_IB_GLOBAL) {
                u32 vtf;

                grh_len = sizeof(struct ib_grh);
                packet->ohdr = packet->ebuf + grh_len;
                packet->grh = packet->ebuf;
                if (packet->grh->next_hdr != IB_GRH_NEXT_HDR)
                        goto drop;
                vtf = be32_to_cpu(packet->grh->version_tclass_flow);
                if ((vtf >> IB_GRH_VERSION_SHIFT) != IB_GRH_VERSION)
                        goto drop;
        } else {
                goto drop;
        }

        /* Query commonly used fields from packet header */
        packet->opcode = ib_bth_get_opcode(packet->ohdr);
        packet->hlen = hdr_len_by_opcode[packet->opcode] + 8 + grh_len;
        packet->payload = packet->ebuf + packet->hlen - (4 * sizeof(u32));
        packet->slid = hfi1_16B_get_slid(packet->hdr);
        packet->dlid = hfi1_16B_get_dlid(packet->hdr);
        if (unlikely(hfi1_is_16B_mcast(packet->dlid)))
                packet->dlid += opa_get_mcast_base(OPA_MCAST_NR) -
                                opa_get_lid(opa_get_mcast_base(OPA_MCAST_NR),
                                            16B);
        packet->sc = hfi1_16B_get_sc(packet->hdr);
        packet->sl = ibp->sc_to_sl[packet->sc];
        packet->pad = hfi1_16B_bth_get_pad(packet->ohdr);
        packet->extra_byte = SIZE_OF_LT;
        packet->fecn = hfi1_16B_get_fecn(packet->hdr);
        packet->becn = hfi1_16B_get_becn(packet->hdr);

        if (hfi1_bypass_ingress_pkt_check(packet))
                goto drop;

        return 0;
drop:
        hfi1_cdbg(PKT, "%s: packet dropped\n", __func__);
        ibp->rvp.n_pkt_drops++;
        return -EINVAL;
}

void handle_eflags(struct hfi1_packet *packet)
{
        struct hfi1_ctxtdata *rcd = packet->rcd;
        u32 rte = rhf_rcv_type_err(packet->rhf);

        rcv_hdrerr(rcd, rcd->ppd, packet);
        if (rhf_err_flags(packet->rhf))
                dd_dev_err(rcd->dd,
                           "receive context %d: rhf 0x%016llx, errs [ %s%s%s%s%s%s%s%s] rte 0x%x\n",
                           rcd->ctxt, packet->rhf,
                           packet->rhf & RHF_K_HDR_LEN_ERR ? "k_hdr_len " : "",
                           packet->rhf & RHF_DC_UNC_ERR ? "dc_unc " : "",
                           packet->rhf & RHF_DC_ERR ? "dc " : "",
                           packet->rhf & RHF_TID_ERR ? "tid " : "",
                           packet->rhf & RHF_LEN_ERR ? "len " : "",
                           packet->rhf & RHF_ECC_ERR ? "ecc " : "",
                           packet->rhf & RHF_VCRC_ERR ? "vcrc " : "",
                           packet->rhf & RHF_ICRC_ERR ? "icrc " : "",
                           rte);
}

/*
 * The following functions are called by the interrupt handler. They are type
 * specific handlers for each packet type.
 */
int process_receive_ib(struct hfi1_packet *packet)
{
        if (unlikely(hfi1_dbg_fault_packet(packet)))
                return RHF_RCV_CONTINUE;

        if (hfi1_setup_9B_packet(packet))
                return RHF_RCV_CONTINUE;

        trace_hfi1_rcvhdr(packet->rcd->ppd->dd,
                          packet->rcd->ctxt,
                          rhf_err_flags(packet->rhf),
                          RHF_RCV_TYPE_IB,
                          packet->hlen,
                          packet->tlen,
                          packet->updegr,
                          rhf_egr_index(packet->rhf));

        if (unlikely(
                 (hfi1_dbg_fault_suppress_err(&packet->rcd->dd->verbs_dev) &&
                 (packet->rhf & RHF_DC_ERR))))
                return RHF_RCV_CONTINUE;

        if (unlikely(rhf_err_flags(packet->rhf))) {
                handle_eflags(packet);
                return RHF_RCV_CONTINUE;
        }

        hfi1_ib_rcv(packet);
        return RHF_RCV_CONTINUE;
}

static inline bool hfi1_is_vnic_packet(struct hfi1_packet *packet)
{
        /* Packet received in VNIC context via RSM */
        if (packet->rcd->is_vnic)
                return true;

        if ((hfi1_16B_get_l2(packet->ebuf) == OPA_16B_L2_TYPE) &&
            (hfi1_16B_get_l4(packet->ebuf) == OPA_16B_L4_ETHR))
                return true;

        return false;
}

int process_receive_bypass(struct hfi1_packet *packet)
{
        struct hfi1_devdata *dd = packet->rcd->dd;

        if (hfi1_is_vnic_packet(packet)) {
                hfi1_vnic_bypass_rcv(packet);
                return RHF_RCV_CONTINUE;
        }

        if (hfi1_setup_bypass_packet(packet))
                return RHF_RCV_CONTINUE;

        if (unlikely(rhf_err_flags(packet->rhf))) {
                handle_eflags(packet);
                return RHF_RCV_CONTINUE;
        }

        if (hfi1_16B_get_l2(packet->hdr) == 0x2) {
                hfi1_16B_rcv(packet);
        } else {
                dd_dev_err(dd,
                           "Bypass packets other than 16B are not supported in normal operation. Dropping\n");
                incr_cntr64(&dd->sw_rcv_bypass_packet_errors);
                if (!(dd->err_info_rcvport.status_and_code &
                      OPA_EI_STATUS_SMASK)) {
                        u64 *flits = packet->ebuf;

                        if (flits && !(packet->rhf & RHF_LEN_ERR)) {
                                dd->err_info_rcvport.packet_flit1 = flits[0];
                                dd->err_info_rcvport.packet_flit2 =
                                        packet->tlen > sizeof(flits[0]) ?
                                        flits[1] : 0;
                        }
                        dd->err_info_rcvport.status_and_code |=
                                (OPA_EI_STATUS_SMASK | BAD_L2_ERR);
                }
        }
        return RHF_RCV_CONTINUE;
}

int process_receive_error(struct hfi1_packet *packet)
{
        /* KHdrHCRCErr -- KDETH packet with a bad HCRC */
        if (unlikely(
                 hfi1_dbg_fault_suppress_err(&packet->rcd->dd->verbs_dev) &&
                 rhf_rcv_type_err(packet->rhf) == 3))
                return RHF_RCV_CONTINUE;

        hfi1_setup_ib_header(packet);
        handle_eflags(packet);

        if (unlikely(rhf_err_flags(packet->rhf)))
                dd_dev_err(packet->rcd->dd,
                           "Unhandled error packet received. Dropping.\n");

        return RHF_RCV_CONTINUE;
}

int kdeth_process_expected(struct hfi1_packet *packet)
{
        if (unlikely(hfi1_dbg_fault_packet(packet)))
                return RHF_RCV_CONTINUE;

        hfi1_setup_ib_header(packet);
        if (unlikely(rhf_err_flags(packet->rhf)))
                handle_eflags(packet);

        dd_dev_err(packet->rcd->dd,
                   "Unhandled expected packet received. Dropping.\n");
        return RHF_RCV_CONTINUE;
}

int kdeth_process_eager(struct hfi1_packet *packet)
{
        hfi1_setup_ib_header(packet);
        if (unlikely(rhf_err_flags(packet->rhf)))
                handle_eflags(packet);
        if (unlikely(hfi1_dbg_fault_packet(packet)))
                return RHF_RCV_CONTINUE;

        dd_dev_err(packet->rcd->dd,
                   "Unhandled eager packet received. Dropping.\n");
        return RHF_RCV_CONTINUE;
}

int process_receive_invalid(struct hfi1_packet *packet)
{
        dd_dev_err(packet->rcd->dd, "Invalid packet type %d. Dropping\n",
                   rhf_rcv_type(packet->rhf));
        return RHF_RCV_CONTINUE;
}

void seqfile_dump_rcd(struct seq_file *s, struct hfi1_ctxtdata *rcd)
{
        struct hfi1_packet packet;
        struct ps_mdata mdata;

        seq_printf(s, "Rcd %u: RcvHdr cnt %u entsize %u %s head %llu tail %llu\n",
                   rcd->ctxt, rcd->rcvhdrq_cnt, rcd->rcvhdrqentsize,
                   HFI1_CAP_KGET_MASK(rcd->flags, DMA_RTAIL) ?
                   "dma_rtail" : "nodma_rtail",
                   read_uctxt_csr(rcd->dd, rcd->ctxt, RCV_HDR_HEAD) &
                   RCV_HDR_HEAD_HEAD_MASK,
                   read_uctxt_csr(rcd->dd, rcd->ctxt, RCV_HDR_TAIL));

        init_packet(rcd, &packet);
        init_ps_mdata(&mdata, &packet);

        while (1) {
                struct hfi1_devdata *dd = rcd->dd;
                __le32 *rhf_addr = (__le32 *)rcd->rcvhdrq + mdata.ps_head +
                                         dd->rhf_offset;
                struct ib_header *hdr;
                u64 rhf = rhf_to_cpu(rhf_addr);
                u32 etype = rhf_rcv_type(rhf), qpn;
                u8 opcode;
                u32 psn;
                u8 lnh;

                if (ps_done(&mdata, rhf, rcd))
                        break;

                if (ps_skip(&mdata, rhf, rcd))
                        goto next;

                if (etype > RHF_RCV_TYPE_IB)
                        goto next;

                packet.hdr = hfi1_get_msgheader(dd, rhf_addr);
                hdr = packet.hdr;

                lnh = be16_to_cpu(hdr->lrh[0]) & 3;

                if (lnh == HFI1_LRH_BTH)
                        packet.ohdr = &hdr->u.oth;
                else if (lnh == HFI1_LRH_GRH)
                        packet.ohdr = &hdr->u.l.oth;
                else
                        goto next; /* just in case */

                opcode = (be32_to_cpu(packet.ohdr->bth[0]) >> 24);
                qpn = be32_to_cpu(packet.ohdr->bth[1]) & RVT_QPN_MASK;
                psn = mask_psn(be32_to_cpu(packet.ohdr->bth[2]));

                seq_printf(s, "\tEnt %u: opcode 0x%x, qpn 0x%x, psn 0x%x\n",
                           mdata.ps_head, opcode, qpn, psn);
next:
                update_ps_mdata(&mdata, rcd);
        }
}