// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause

/* Authors: Bernard Metzler <bmt@zurich.ibm.com> */
/* Copyright (c) 2008-2019, IBM Corporation */

#include <linux/errno.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/vmalloc.h>
#include <linux/xarray.h>

#include <rdma/iw_cm.h>
#include <rdma/ib_verbs.h>
#include <rdma/ib_user_verbs.h>
#include <rdma/uverbs_ioctl.h>

#include "siw.h"
#include "siw_verbs.h"
#include "siw_mem.h"

static int ib_qp_state_to_siw_qp_state[IB_QPS_ERR + 1] = {
        [IB_QPS_RESET] = SIW_QP_STATE_IDLE,
        [IB_QPS_INIT] = SIW_QP_STATE_IDLE,
        [IB_QPS_RTR] = SIW_QP_STATE_RTR,
        [IB_QPS_RTS] = SIW_QP_STATE_RTS,
        [IB_QPS_SQD] = SIW_QP_STATE_CLOSING,
        [IB_QPS_SQE] = SIW_QP_STATE_TERMINATE,
        [IB_QPS_ERR] = SIW_QP_STATE_ERROR
};

static char ib_qp_state_to_string[IB_QPS_ERR + 1][sizeof("RESET")] = {
        [IB_QPS_RESET] = "RESET", [IB_QPS_INIT] = "INIT", [IB_QPS_RTR] = "RTR",
        [IB_QPS_RTS] = "RTS",     [IB_QPS_SQD] = "SQD",   [IB_QPS_SQE] = "SQE",
        [IB_QPS_ERR] = "ERR"
};

void siw_mmap_free(struct rdma_user_mmap_entry *rdma_entry)
{
        struct siw_user_mmap_entry *entry = to_siw_mmap_entry(rdma_entry);

        kfree(entry);
}

int siw_mmap(struct ib_ucontext *ctx, struct vm_area_struct *vma)
{
        struct siw_ucontext *uctx = to_siw_ctx(ctx);
        size_t size = vma->vm_end - vma->vm_start;
        struct rdma_user_mmap_entry *rdma_entry;
        struct siw_user_mmap_entry *entry;
        int rv = -EINVAL;

        /*
         * Must be page aligned
         */
        if (vma->vm_start & (PAGE_SIZE - 1)) {
                pr_warn("siw: mmap not page aligned\n");
                return -EINVAL;
        }
        rdma_entry = rdma_user_mmap_entry_get(&uctx->base_ucontext, vma);
        if (!rdma_entry) {
                siw_dbg(&uctx->sdev->base_dev, "mmap lookup failed: %lu, %#zx\n",
                        vma->vm_pgoff, size);
                return -EINVAL;
        }
        entry = to_siw_mmap_entry(rdma_entry);

        rv = remap_vmalloc_range(vma, entry->address, 0);
        if (rv) {
                pr_warn("remap_vmalloc_range failed: %lu, %zu\n", vma->vm_pgoff,
                        size);
                goto out;
        }
out:
        rdma_user_mmap_entry_put(rdma_entry);

        return rv;
}

int siw_alloc_ucontext(struct ib_ucontext *base_ctx, struct ib_udata *udata)
{
        struct siw_device *sdev = to_siw_dev(base_ctx->device);
        struct siw_ucontext *ctx = to_siw_ctx(base_ctx);
        struct siw_uresp_alloc_ctx uresp = {};
        int rv;

        if (atomic_inc_return(&sdev->num_ctx) > SIW_MAX_CONTEXT) {
                rv = -ENOMEM;
                goto err_out;
        }
        ctx->sdev = sdev;

        uresp.dev_id = sdev->vendor_part_id;

        if (udata->outlen < sizeof(uresp)) {
                rv = -EINVAL;
                goto err_out;
        }
        rv = ib_copy_to_udata(udata, &uresp, sizeof(uresp));
        if (rv)
                goto err_out;

        siw_dbg(base_ctx->device, "success. now %d context(s)\n",
                atomic_read(&sdev->num_ctx));

        return 0;

err_out:
        atomic_dec(&sdev->num_ctx);
        siw_dbg(base_ctx->device, "failure %d. now %d context(s)\n", rv,
                atomic_read(&sdev->num_ctx));

        return rv;
}

void siw_dealloc_ucontext(struct ib_ucontext *base_ctx)
{
        struct siw_ucontext *uctx = to_siw_ctx(base_ctx);

        atomic_dec(&uctx->sdev->num_ctx);
}

int siw_query_device(struct ib_device *base_dev, struct ib_device_attr *attr,
                     struct ib_udata *udata)
{
        struct siw_device *sdev = to_siw_dev(base_dev);

        if (udata->inlen || udata->outlen)
                return -EINVAL;

        memset(attr, 0, sizeof(*attr));

        /* Revisit atomic caps if RFC 7306 gets supported */
        attr->atomic_cap = 0;
        attr->device_cap_flags =
                IB_DEVICE_MEM_MGT_EXTENSIONS | IB_DEVICE_ALLOW_USER_UNREG;
        attr->max_cq = sdev->attrs.max_cq;
        attr->max_cqe = sdev->attrs.max_cqe;
        attr->max_fast_reg_page_list_len = SIW_MAX_SGE_PBL;
        attr->max_mr = sdev->attrs.max_mr;
        attr->max_mw = sdev->attrs.max_mw;
        attr->max_mr_size = ~0ull;
        attr->max_pd = sdev->attrs.max_pd;
        attr->max_qp = sdev->attrs.max_qp;
        attr->max_qp_init_rd_atom = sdev->attrs.max_ird;
        attr->max_qp_rd_atom = sdev->attrs.max_ord;
        attr->max_qp_wr = sdev->attrs.max_qp_wr;
        attr->max_recv_sge = sdev->attrs.max_sge;
        attr->max_res_rd_atom = sdev->attrs.max_qp * sdev->attrs.max_ird;
        attr->max_send_sge = sdev->attrs.max_sge;
        attr->max_sge_rd = sdev->attrs.max_sge_rd;
        attr->max_srq = sdev->attrs.max_srq;
        attr->max_srq_sge = sdev->attrs.max_srq_sge;
        attr->max_srq_wr = sdev->attrs.max_srq_wr;
        attr->page_size_cap = PAGE_SIZE;
        attr->vendor_id = SIW_VENDOR_ID;
        attr->vendor_part_id = sdev->vendor_part_id;

        memcpy(&attr->sys_image_guid, sdev->netdev->dev_addr, 6);

        return 0;
}

int siw_query_port(struct ib_device *base_dev, u32 port,
                   struct ib_port_attr *attr)
{
        struct siw_device *sdev = to_siw_dev(base_dev);
        int rv;

        memset(attr, 0, sizeof(*attr));

        rv = ib_get_eth_speed(base_dev, port, &attr->active_speed,
                         &attr->active_width);
        attr->gid_tbl_len = 1;
        attr->max_msg_sz = -1;
        attr->max_mtu = ib_mtu_int_to_enum(sdev->netdev->mtu);
        attr->active_mtu = ib_mtu_int_to_enum(sdev->netdev->mtu);
        attr->phys_state = sdev->state == IB_PORT_ACTIVE ?
                IB_PORT_PHYS_STATE_LINK_UP : IB_PORT_PHYS_STATE_DISABLED;
        attr->port_cap_flags = IB_PORT_CM_SUP | IB_PORT_DEVICE_MGMT_SUP;
        attr->state = sdev->state;
        /*
         * All zero
         *
         * attr->lid = 0;
         * attr->bad_pkey_cntr = 0;
         * attr->qkey_viol_cntr = 0;
         * attr->sm_lid = 0;
         * attr->lmc = 0;
         * attr->max_vl_num = 0;
         * attr->sm_sl = 0;
         * attr->subnet_timeout = 0;
         * attr->init_type_repy = 0;
         */
        return rv;
}

int siw_get_port_immutable(struct ib_device *base_dev, u32 port,
                           struct ib_port_immutable *port_immutable)
{
        struct ib_port_attr attr;
        int rv = siw_query_port(base_dev, port, &attr);

        if (rv)
                return rv;

        port_immutable->gid_tbl_len = attr.gid_tbl_len;
        port_immutable->core_cap_flags = RDMA_CORE_PORT_IWARP;

        return 0;
}

int siw_query_gid(struct ib_device *base_dev, u32 port, int idx,
                  union ib_gid *gid)
{
        struct siw_device *sdev = to_siw_dev(base_dev);

        /* subnet_prefix == interface_id == 0; */
        memset(gid, 0, sizeof(*gid));
        memcpy(&gid->raw[0], sdev->netdev->dev_addr, 6);

        return 0;
}

int siw_alloc_pd(struct ib_pd *pd, struct ib_udata *udata)
{
        struct siw_device *sdev = to_siw_dev(pd->device);

        if (atomic_inc_return(&sdev->num_pd) > SIW_MAX_PD) {
                atomic_dec(&sdev->num_pd);
                return -ENOMEM;
        }
        siw_dbg_pd(pd, "now %d PD's(s)\n", atomic_read(&sdev->num_pd));

        return 0;
}

int siw_dealloc_pd(struct ib_pd *pd, struct ib_udata *udata)
{
        struct siw_device *sdev = to_siw_dev(pd->device);

        siw_dbg_pd(pd, "free PD\n");
        atomic_dec(&sdev->num_pd);
        return 0;
}

void siw_qp_get_ref(struct ib_qp *base_qp)
{
        siw_qp_get(to_siw_qp(base_qp));
}

void siw_qp_put_ref(struct ib_qp *base_qp)
{
        siw_qp_put(to_siw_qp(base_qp));
}

static struct rdma_user_mmap_entry *
siw_mmap_entry_insert(struct siw_ucontext *uctx,
                      void *address, size_t length,
                      u64 *offset)
{
        struct siw_user_mmap_entry *entry = kzalloc(sizeof(*entry), GFP_KERNEL);
        int rv;

        *offset = SIW_INVAL_UOBJ_KEY;
        if (!entry)
                return NULL;

        entry->address = address;

        rv = rdma_user_mmap_entry_insert(&uctx->base_ucontext,
                                         &entry->rdma_entry,
                                         length);
        if (rv) {
                kfree(entry);
                return NULL;
        }

        *offset = rdma_user_mmap_get_offset(&entry->rdma_entry);

        return &entry->rdma_entry;
}

/*
 * siw_create_qp()
 *
 * Create QP of requested size on given device.
 *
 * @qp:         Queue pait
 * @attrs:      Initial QP attributes.
 * @udata:      used to provide QP ID, SQ and RQ size back to user.
 */

int siw_create_qp(struct ib_qp *ibqp, struct ib_qp_init_attr *attrs,
                  struct ib_udata *udata)
{
        struct ib_pd *pd = ibqp->pd;
        struct siw_qp *qp = to_siw_qp(ibqp);
        struct ib_device *base_dev = pd->device;
        struct siw_device *sdev = to_siw_dev(base_dev);
        struct siw_ucontext *uctx =
                rdma_udata_to_drv_context(udata, struct siw_ucontext,
                                          base_ucontext);
        unsigned long flags;
        int num_sqe, num_rqe, rv = 0;
        size_t length;

        siw_dbg(base_dev, "create new QP\n");

        if (attrs->create_flags)
                return -EOPNOTSUPP;

        if (atomic_inc_return(&sdev->num_qp) > SIW_MAX_QP) {
                siw_dbg(base_dev, "too many QP's\n");
                return -ENOMEM;
        }
        if (attrs->qp_type != IB_QPT_RC) {
                siw_dbg(base_dev, "only RC QP's supported\n");
                rv = -EOPNOTSUPP;
                goto err_atomic;
        }
        if ((attrs->cap.max_send_wr > SIW_MAX_QP_WR) ||
            (attrs->cap.max_recv_wr > SIW_MAX_QP_WR) ||
            (attrs->cap.max_send_sge > SIW_MAX_SGE) ||
            (attrs->cap.max_recv_sge > SIW_MAX_SGE)) {
                siw_dbg(base_dev, "QP size error\n");
                rv = -EINVAL;
                goto err_atomic;
        }
        if (attrs->cap.max_inline_data > SIW_MAX_INLINE) {
                siw_dbg(base_dev, "max inline send: %d > %d\n",
                        attrs->cap.max_inline_data, (int)SIW_MAX_INLINE);
                rv = -EINVAL;
                goto err_atomic;
        }
        /*
         * NOTE: we allow for zero element SQ and RQ WQE's SGL's
         * but not for a QP unable to hold any WQE (SQ + RQ)
         */
        if (attrs->cap.max_send_wr + attrs->cap.max_recv_wr == 0) {
                siw_dbg(base_dev, "QP must have send or receive queue\n");
                rv = -EINVAL;
                goto err_atomic;
        }

        if (!attrs->send_cq || (!attrs->recv_cq && !attrs->srq)) {
                siw_dbg(base_dev, "send CQ or receive CQ invalid\n");
                rv = -EINVAL;
                goto err_atomic;
        }

        init_rwsem(&qp->state_lock);
        spin_lock_init(&qp->sq_lock);
        spin_lock_init(&qp->rq_lock);
        spin_lock_init(&qp->orq_lock);

        rv = siw_qp_add(sdev, qp);
        if (rv)
                goto err_atomic;

        num_sqe = attrs->cap.max_send_wr;
        num_rqe = attrs->cap.max_recv_wr;

        /* All queue indices are derived from modulo operations
         * on a free running 'get' (consumer) and 'put' (producer)
         * unsigned counter. Having queue sizes at power of two
         * avoids handling counter wrap around.
         */
        if (num_sqe)
                num_sqe = roundup_pow_of_two(num_sqe);
        else {
                /* Zero sized SQ is not supported */
                rv = -EINVAL;
                goto err_out_xa;
        }
        if (num_rqe)
                num_rqe = roundup_pow_of_two(num_rqe);

        if (udata)
                qp->sendq = vmalloc_user(num_sqe * sizeof(struct siw_sqe));
        else
                qp->sendq = vzalloc(num_sqe * sizeof(struct siw_sqe));

        if (qp->sendq == NULL) {
                rv = -ENOMEM;
                goto err_out_xa;
        }
        if (attrs->sq_sig_type != IB_SIGNAL_REQ_WR) {
                if (attrs->sq_sig_type == IB_SIGNAL_ALL_WR)
                        qp->attrs.flags |= SIW_SIGNAL_ALL_WR;
                else {
                        rv = -EINVAL;
                        goto err_out_xa;
                }
        }
        qp->pd = pd;
        qp->scq = to_siw_cq(attrs->send_cq);
        qp->rcq = to_siw_cq(attrs->recv_cq);

        if (attrs->srq) {
                /*
                 * SRQ support.
                 * Verbs 6.3.7: ignore RQ size, if SRQ present
                 * Verbs 6.3.5: do not check PD of SRQ against PD of QP
                 */
                qp->srq = to_siw_srq(attrs->srq);
                qp->attrs.rq_size = 0;
                siw_dbg(base_dev, "QP [%u]: SRQ attached\n",
                        qp->base_qp.qp_num);
        } else if (num_rqe) {
                if (udata)
                        qp->recvq =
                                vmalloc_user(num_rqe * sizeof(struct siw_rqe));
                else
                        qp->recvq = vzalloc(num_rqe * sizeof(struct siw_rqe));

                if (qp->recvq == NULL) {
                        rv = -ENOMEM;
                        goto err_out_xa;
                }
                qp->attrs.rq_size = num_rqe;
        }
        qp->attrs.sq_size = num_sqe;
        qp->attrs.sq_max_sges = attrs->cap.max_send_sge;
        qp->attrs.rq_max_sges = attrs->cap.max_recv_sge;

        /* Make those two tunables fixed for now. */
        qp->tx_ctx.gso_seg_limit = 1;
        qp->tx_ctx.zcopy_tx = zcopy_tx;

        qp->attrs.state = SIW_QP_STATE_IDLE;

        if (udata) {
                struct siw_uresp_create_qp uresp = {};

                uresp.num_sqe = num_sqe;
                uresp.num_rqe = num_rqe;
                uresp.qp_id = qp_id(qp);

                if (qp->sendq) {
                        length = num_sqe * sizeof(struct siw_sqe);
                        qp->sq_entry =
                                siw_mmap_entry_insert(uctx, qp->sendq,
                                                      length, &uresp.sq_key);
                        if (!qp->sq_entry) {
                                rv = -ENOMEM;
                                goto err_out_xa;
                        }
                }

                if (qp->recvq) {
                        length = num_rqe * sizeof(struct siw_rqe);
                        qp->rq_entry =
                                siw_mmap_entry_insert(uctx, qp->recvq,
                                                      length, &uresp.rq_key);
                        if (!qp->rq_entry) {
                                uresp.sq_key = SIW_INVAL_UOBJ_KEY;
                                rv = -ENOMEM;
                                goto err_out_xa;
                        }
                }

                if (udata->outlen < sizeof(uresp)) {
                        rv = -EINVAL;
                        goto err_out_xa;
                }
                rv = ib_copy_to_udata(udata, &uresp, sizeof(uresp));
                if (rv)
                        goto err_out_xa;
        }
        qp->tx_cpu = siw_get_tx_cpu(sdev);
        if (qp->tx_cpu < 0) {
                rv = -EINVAL;
                goto err_out_xa;
        }
        INIT_LIST_HEAD(&qp->devq);
        spin_lock_irqsave(&sdev->lock, flags);
        list_add_tail(&qp->devq, &sdev->qp_list);
        spin_unlock_irqrestore(&sdev->lock, flags);

        return 0;

err_out_xa:
        xa_erase(&sdev->qp_xa, qp_id(qp));
        if (uctx) {
                rdma_user_mmap_entry_remove(qp->sq_entry);
                rdma_user_mmap_entry_remove(qp->rq_entry);
        }
        vfree(qp->sendq);
        vfree(qp->recvq);

err_atomic:
        atomic_dec(&sdev->num_qp);
        return rv;
}

/*
 * Minimum siw_query_qp() verb interface.
 *
 * @qp_attr_mask is not used but all available information is provided
 */
int siw_query_qp(struct ib_qp *base_qp, struct ib_qp_attr *qp_attr,
                 int qp_attr_mask, struct ib_qp_init_attr *qp_init_attr)
{
        struct siw_qp *qp;
        struct siw_device *sdev;

        if (base_qp && qp_attr && qp_init_attr) {
                qp = to_siw_qp(base_qp);
                sdev = to_siw_dev(base_qp->device);
        } else {
                return -EINVAL;
        }
        qp_attr->cap.max_inline_data = SIW_MAX_INLINE;
        qp_attr->cap.max_send_wr = qp->attrs.sq_size;
        qp_attr->cap.max_send_sge = qp->attrs.sq_max_sges;
        qp_attr->cap.max_recv_wr = qp->attrs.rq_size;
        qp_attr->cap.max_recv_sge = qp->attrs.rq_max_sges;
        qp_attr->path_mtu = ib_mtu_int_to_enum(sdev->netdev->mtu);
        qp_attr->max_rd_atomic = qp->attrs.irq_size;
        qp_attr->max_dest_rd_atomic = qp->attrs.orq_size;

        qp_attr->qp_access_flags = IB_ACCESS_LOCAL_WRITE |
                                   IB_ACCESS_REMOTE_WRITE |
                                   IB_ACCESS_REMOTE_READ;

        qp_init_attr->qp_type = base_qp->qp_type;
        qp_init_attr->send_cq = base_qp->send_cq;
        qp_init_attr->recv_cq = base_qp->recv_cq;
        qp_init_attr->srq = base_qp->srq;

        qp_init_attr->cap = qp_attr->cap;

        return 0;
}

int siw_verbs_modify_qp(struct ib_qp *base_qp, struct ib_qp_attr *attr,
                        int attr_mask, struct ib_udata *udata)
{
        struct siw_qp_attrs new_attrs;
        enum siw_qp_attr_mask siw_attr_mask = 0;
        struct siw_qp *qp = to_siw_qp(base_qp);
        int rv = 0;

        if (!attr_mask)
                return 0;

        if (attr_mask & ~IB_QP_ATTR_STANDARD_BITS)
                return -EOPNOTSUPP;

        memset(&new_attrs, 0, sizeof(new_attrs));

        if (attr_mask & IB_QP_ACCESS_FLAGS) {
                siw_attr_mask = SIW_QP_ATTR_ACCESS_FLAGS;

                if (attr->qp_access_flags & IB_ACCESS_REMOTE_READ)
                        new_attrs.flags |= SIW_RDMA_READ_ENABLED;
                if (attr->qp_access_flags & IB_ACCESS_REMOTE_WRITE)
                        new_attrs.flags |= SIW_RDMA_WRITE_ENABLED;
                if (attr->qp_access_flags & IB_ACCESS_MW_BIND)
                        new_attrs.flags |= SIW_RDMA_BIND_ENABLED;
        }
        if (attr_mask & IB_QP_STATE) {
                siw_dbg_qp(qp, "desired IB QP state: %s\n",
                           ib_qp_state_to_string[attr->qp_state]);

                new_attrs.state = ib_qp_state_to_siw_qp_state[attr->qp_state];

                if (new_attrs.state > SIW_QP_STATE_RTS)
                        qp->tx_ctx.tx_suspend = 1;

                siw_attr_mask |= SIW_QP_ATTR_STATE;
        }
        if (!siw_attr_mask)
                goto out;

        down_write(&qp->state_lock);

        rv = siw_qp_modify(qp, &new_attrs, siw_attr_mask);

        up_write(&qp->state_lock);
out:
        return rv;
}

int siw_destroy_qp(struct ib_qp *base_qp, struct ib_udata *udata)
{
        struct siw_qp *qp = to_siw_qp(base_qp);
        struct siw_ucontext *uctx =
                rdma_udata_to_drv_context(udata, struct siw_ucontext,
                                          base_ucontext);
        struct siw_qp_attrs qp_attrs;

        siw_dbg_qp(qp, "state %d\n", qp->attrs.state);

        /*
         * Mark QP as in process of destruction to prevent from
         * any async callbacks to RDMA core
         */
        qp->attrs.flags |= SIW_QP_IN_DESTROY;
        qp->rx_stream.rx_suspend = 1;

        if (uctx) {
                rdma_user_mmap_entry_remove(qp->sq_entry);
                rdma_user_mmap_entry_remove(qp->rq_entry);
        }

        down_write(&qp->state_lock);

        qp_attrs.state = SIW_QP_STATE_ERROR;
        siw_qp_modify(qp, &qp_attrs, SIW_QP_ATTR_STATE);

        if (qp->cep) {
                siw_cep_put(qp->cep);
                qp->cep = NULL;
        }
        up_write(&qp->state_lock);

        kfree(qp->tx_ctx.mpa_crc_hd);
        kfree(qp->rx_stream.mpa_crc_hd);

        qp->scq = qp->rcq = NULL;

        siw_qp_put(qp);

        return 0;
}

/*
 * siw_copy_inline_sgl()
 *
 * Prepare sgl of inlined data for sending. For userland callers
 * function checks if given buffer addresses and len's are within
 * process context bounds.
 * Data from all provided sge's are copied together into the wqe,
 * referenced by a single sge.
 */
static int siw_copy_inline_sgl(const struct ib_send_wr *core_wr,
                               struct siw_sqe *sqe)
{
        struct ib_sge *core_sge = core_wr->sg_list;
        void *kbuf = &sqe->sge[1];
        int num_sge = core_wr->num_sge, bytes = 0;

        sqe->sge[0].laddr = (uintptr_t)kbuf;
        sqe->sge[0].lkey = 0;

        while (num_sge--) {
                if (!core_sge->length) {
                        core_sge++;
                        continue;
                }
                bytes += core_sge->length;
                if (bytes > SIW_MAX_INLINE) {
                        bytes = -EINVAL;
                        break;
                }
                memcpy(kbuf, (void *)(uintptr_t)core_sge->addr,
                       core_sge->length);

                kbuf += core_sge->length;
                core_sge++;
        }
        sqe->sge[0].length = bytes > 0 ? bytes : 0;
        sqe->num_sge = bytes > 0 ? 1 : 0;

        return bytes;
}

/* Complete SQ WR's without processing */
static int siw_sq_flush_wr(struct siw_qp *qp, const struct ib_send_wr *wr,
                           const struct ib_send_wr **bad_wr)
{
        struct siw_sqe sqe = {};
        int rv = 0;

        while (wr) {
                sqe.id = wr->wr_id;
                sqe.opcode = wr->opcode;
                rv = siw_sqe_complete(qp, &sqe, 0, SIW_WC_WR_FLUSH_ERR);
                if (rv) {
                        if (bad_wr)
                                *bad_wr = wr;
                        break;
                }
                wr = wr->next;
        }
        return rv;
}

/* Complete RQ WR's without processing */
static int siw_rq_flush_wr(struct siw_qp *qp, const struct ib_recv_wr *wr,
                           const struct ib_recv_wr **bad_wr)
{
        struct siw_rqe rqe = {};
        int rv = 0;

        while (wr) {
                rqe.id = wr->wr_id;
                rv = siw_rqe_complete(qp, &rqe, 0, 0, SIW_WC_WR_FLUSH_ERR);
                if (rv) {
                        if (bad_wr)
                                *bad_wr = wr;
                        break;
                }
                wr = wr->next;
        }
        return rv;
}

/*
 * siw_post_send()
 *
 * Post a list of S-WR's to a SQ.
 *
 * @base_qp:    Base QP contained in siw QP
 * @wr:         Null terminated list of user WR's
 * @bad_wr:     Points to failing WR in case of synchronous failure.
 */
int siw_post_send(struct ib_qp *base_qp, const struct ib_send_wr *wr,
                  const struct ib_send_wr **bad_wr)
{
        struct siw_qp *qp = to_siw_qp(base_qp);
        struct siw_wqe *wqe = tx_wqe(qp);

        unsigned long flags;
        int rv = 0;

        if (wr && !rdma_is_kernel_res(&qp->base_qp.res)) {
                siw_dbg_qp(qp, "wr must be empty for user mapped sq\n");
                *bad_wr = wr;
                return -EINVAL;
        }

        /*
         * Try to acquire QP state lock. Must be non-blocking
         * to accommodate kernel clients needs.
         */
        if (!down_read_trylock(&qp->state_lock)) {
                if (qp->attrs.state == SIW_QP_STATE_ERROR) {
                        /*
                         * ERROR state is final, so we can be sure
                         * this state will not change as long as the QP
                         * exists.
                         *
                         * This handles an ib_drain_sq() call with
                         * a concurrent request to set the QP state
                         * to ERROR.
                         */
                        rv = siw_sq_flush_wr(qp, wr, bad_wr);
                } else {
                        siw_dbg_qp(qp, "QP locked, state %d\n",
                                   qp->attrs.state);
                        *bad_wr = wr;
                        rv = -ENOTCONN;
                }
                return rv;
        }
        if (unlikely(qp->attrs.state != SIW_QP_STATE_RTS)) {
                if (qp->attrs.state == SIW_QP_STATE_ERROR) {
                        /*
                         * Immediately flush this WR to CQ, if QP
                         * is in ERROR state. SQ is guaranteed to
                         * be empty, so WR complets in-order.
                         *
                         * Typically triggered by ib_drain_sq().
                         */
                        rv = siw_sq_flush_wr(qp, wr, bad_wr);
                } else {
                        siw_dbg_qp(qp, "QP out of state %d\n",
                                   qp->attrs.state);
                        *bad_wr = wr;
                        rv = -ENOTCONN;
                }
                up_read(&qp->state_lock);
                return rv;
        }
        spin_lock_irqsave(&qp->sq_lock, flags);

        while (wr) {
                u32 idx = qp->sq_put % qp->attrs.sq_size;
                struct siw_sqe *sqe = &qp->sendq[idx];

                if (sqe->flags) {
                        siw_dbg_qp(qp, "sq full\n");
                        rv = -ENOMEM;
                        break;
                }
                if (wr->num_sge > qp->attrs.sq_max_sges) {
                        siw_dbg_qp(qp, "too many sge's: %d\n", wr->num_sge);
                        rv = -EINVAL;
                        break;
                }
                sqe->id = wr->wr_id;

                if ((wr->send_flags & IB_SEND_SIGNALED) ||
                    (qp->attrs.flags & SIW_SIGNAL_ALL_WR))
                        sqe->flags |= SIW_WQE_SIGNALLED;

                if (wr->send_flags & IB_SEND_FENCE)
                        sqe->flags |= SIW_WQE_READ_FENCE;

                switch (wr->opcode) {
                case IB_WR_SEND:
                case IB_WR_SEND_WITH_INV:
                        if (wr->send_flags & IB_SEND_SOLICITED)
                                sqe->flags |= SIW_WQE_SOLICITED;

                        if (!(wr->send_flags & IB_SEND_INLINE)) {
                                siw_copy_sgl(wr->sg_list, sqe->sge,
                                             wr->num_sge);
                                sqe->num_sge = wr->num_sge;
                        } else {
                                rv = siw_copy_inline_sgl(wr, sqe);
                                if (rv <= 0) {
                                        rv = -EINVAL;
                                        break;
                                }
                                sqe->flags |= SIW_WQE_INLINE;
                                sqe->num_sge = 1;
                        }
                        if (wr->opcode == IB_WR_SEND)
                                sqe->opcode = SIW_OP_SEND;
                        else {
                                sqe->opcode = SIW_OP_SEND_REMOTE_INV;
                                sqe->rkey = wr->ex.invalidate_rkey;
                        }
                        break;

                case IB_WR_RDMA_READ_WITH_INV:
                case IB_WR_RDMA_READ:
                        /*
                         * iWarp restricts RREAD sink to SGL containing
                         * 1 SGE only. we could relax to SGL with multiple
                         * elements referring the SAME ltag or even sending
                         * a private per-rreq tag referring to a checked
                         * local sgl with MULTIPLE ltag's.
                         */
                        if (unlikely(wr->num_sge != 1)) {
                                rv = -EINVAL;
                                break;
                        }
                        siw_copy_sgl(wr->sg_list, &sqe->sge[0], 1);
                        /*
                         * NOTE: zero length RREAD is allowed!
                         */
                        sqe->raddr = rdma_wr(wr)->remote_addr;
                        sqe->rkey = rdma_wr(wr)->rkey;
                        sqe->num_sge = 1;

                        if (wr->opcode == IB_WR_RDMA_READ)
                                sqe->opcode = SIW_OP_READ;
                        else
                                sqe->opcode = SIW_OP_READ_LOCAL_INV;
                        break;

                case IB_WR_RDMA_WRITE:
                        if (!(wr->send_flags & IB_SEND_INLINE)) {
                                siw_copy_sgl(wr->sg_list, &sqe->sge[0],
                                             wr->num_sge);
                                sqe->num_sge = wr->num_sge;
                        } else {
                                rv = siw_copy_inline_sgl(wr, sqe);
                                if (unlikely(rv < 0)) {
                                        rv = -EINVAL;
                                        break;
                                }
                                sqe->flags |= SIW_WQE_INLINE;
                                sqe->num_sge = 1;
                        }
                        sqe->raddr = rdma_wr(wr)->remote_addr;
                        sqe->rkey = rdma_wr(wr)->rkey;
                        sqe->opcode = SIW_OP_WRITE;
                        break;

                case IB_WR_REG_MR:
                        sqe->base_mr = (uintptr_t)reg_wr(wr)->mr;
                        sqe->rkey = reg_wr(wr)->key;
                        sqe->access = reg_wr(wr)->access & IWARP_ACCESS_MASK;
                        sqe->opcode = SIW_OP_REG_MR;
                        break;

                case IB_WR_LOCAL_INV:
                        sqe->rkey = wr->ex.invalidate_rkey;
                        sqe->opcode = SIW_OP_INVAL_STAG;
                        break;

                default:
                        siw_dbg_qp(qp, "ib wr type %d unsupported\n",
                                   wr->opcode);
                        rv = -EINVAL;
                        break;
                }
                siw_dbg_qp(qp, "opcode %d, flags 0x%x, wr_id 0x%pK\n",
                           sqe->opcode, sqe->flags,
                           (void *)(uintptr_t)sqe->id);

                if (unlikely(rv < 0))
                        break;

                /* make SQE only valid after completely written */
                smp_wmb();
                sqe->flags |= SIW_WQE_VALID;

                qp->sq_put++;
                wr = wr->next;
        }

        /*
         * Send directly if SQ processing is not in progress.
         * Eventual immediate errors (rv < 0) do not affect the involved
         * RI resources (Verbs, 8.3.1) and thus do not prevent from SQ
         * processing, if new work is already pending. But rv must be passed
         * to caller.
         */
        if (wqe->wr_status != SIW_WR_IDLE) {
                spin_unlock_irqrestore(&qp->sq_lock, flags);
                goto skip_direct_sending;
        }
        rv = siw_activate_tx(qp);
        spin_unlock_irqrestore(&qp->sq_lock, flags);

        if (rv <= 0)
                goto skip_direct_sending;

        if (rdma_is_kernel_res(&qp->base_qp.res)) {
                rv = siw_sq_start(qp);
        } else {
                qp->tx_ctx.in_syscall = 1;

                if (siw_qp_sq_process(qp) != 0 && !(qp->tx_ctx.tx_suspend))
                        siw_qp_cm_drop(qp, 0);

                qp->tx_ctx.in_syscall = 0;
        }
skip_direct_sending:

        up_read(&qp->state_lock);

        if (rv >= 0)
                return 0;
        /*
         * Immediate error
         */
        siw_dbg_qp(qp, "error %d\n", rv);

        *bad_wr = wr;
        return rv;
}

/*
 * siw_post_receive()
 *
 * Post a list of R-WR's to a RQ.
 *
 * @base_qp:    Base QP contained in siw QP
 * @wr:         Null terminated list of user WR's
 * @bad_wr:     Points to failing WR in case of synchronous failure.
 */
int siw_post_receive(struct ib_qp *base_qp, const struct ib_recv_wr *wr,
                     const struct ib_recv_wr **bad_wr)
{
        struct siw_qp *qp = to_siw_qp(base_qp);
        unsigned long flags;
        int rv = 0;

        if (qp->srq || qp->attrs.rq_size == 0) {
                *bad_wr = wr;
                return -EINVAL;
        }
        if (!rdma_is_kernel_res(&qp->base_qp.res)) {
                siw_dbg_qp(qp, "no kernel post_recv for user mapped rq\n");
                *bad_wr = wr;
                return -EINVAL;
        }

        /*
         * Try to acquire QP state lock. Must be non-blocking
         * to accommodate kernel clients needs.
         */
        if (!down_read_trylock(&qp->state_lock)) {
                if (qp->attrs.state == SIW_QP_STATE_ERROR) {
                        /*
                         * ERROR state is final, so we can be sure
                         * this state will not change as long as the QP
                         * exists.
                         *
                         * This handles an ib_drain_rq() call with
                         * a concurrent request to set the QP state
                         * to ERROR.
                         */
                        rv = siw_rq_flush_wr(qp, wr, bad_wr);
                } else {
                        siw_dbg_qp(qp, "QP locked, state %d\n",
                                   qp->attrs.state);
                        *bad_wr = wr;
                        rv = -ENOTCONN;
                }
                return rv;
        }
        if (qp->attrs.state > SIW_QP_STATE_RTS) {

                if (qp->attrs.state == SIW_QP_STATE_ERROR) {
                        /*
                         * Immediately flush this WR to CQ, if QP
                         * is in ERROR state. RQ is guaranteed to
                         * be empty, so WR complets in-order.
                         *
                         * Typically triggered by ib_drain_rq().
                         */
                        rv = siw_rq_flush_wr(qp, wr, bad_wr);
                } else {
                        siw_dbg_qp(qp, "QP out of state %d\n",
                                   qp->attrs.state);
                        *bad_wr = wr;
                        rv = -ENOTCONN;
                }
                up_read(&qp->state_lock);
                return rv;
        }
        /*
         * Serialize potentially multiple producers.
         * Not needed for single threaded consumer side.
         */
        spin_lock_irqsave(&qp->rq_lock, flags);

        while (wr) {
                u32 idx = qp->rq_put % qp->attrs.rq_size;
                struct siw_rqe *rqe = &qp->recvq[idx];

                if (rqe->flags) {
                        siw_dbg_qp(qp, "RQ full\n");
                        rv = -ENOMEM;
                        break;
                }
                if (wr->num_sge > qp->attrs.rq_max_sges) {
                        siw_dbg_qp(qp, "too many sge's: %d\n", wr->num_sge);
                        rv = -EINVAL;
                        break;
                }
                rqe->id = wr->wr_id;
                rqe->num_sge = wr->num_sge;
                siw_copy_sgl(wr->sg_list, rqe->sge, wr->num_sge);

                /* make sure RQE is completely written before valid */
                smp_wmb();

                rqe->flags = SIW_WQE_VALID;

                qp->rq_put++;
                wr = wr->next;
        }
        spin_unlock_irqrestore(&qp->rq_lock, flags);

        up_read(&qp->state_lock);

        if (rv < 0) {
                siw_dbg_qp(qp, "error %d\n", rv);
                *bad_wr = wr;
        }
        return rv > 0 ? 0 : rv;
}

int siw_destroy_cq(struct ib_cq *base_cq, struct ib_udata *udata)
{
        struct siw_cq *cq = to_siw_cq(base_cq);
        struct siw_device *sdev = to_siw_dev(base_cq->device);
        struct siw_ucontext *ctx =
                rdma_udata_to_drv_context(udata, struct siw_ucontext,
                                          base_ucontext);

        siw_dbg_cq(cq, "free CQ resources\n");

        siw_cq_flush(cq);

        if (ctx)
                rdma_user_mmap_entry_remove(cq->cq_entry);

        atomic_dec(&sdev->num_cq);

        vfree(cq->queue);
        return 0;
}

/*
 * siw_create_cq()
 *
 * Populate CQ of requested size
 *
 * @base_cq: CQ as allocated by RDMA midlayer
 * @attr: Initial CQ attributes
 * @udata: relates to user context
 */

int siw_create_cq(struct ib_cq *base_cq, const struct ib_cq_init_attr *attr,
                  struct ib_udata *udata)
{
        struct siw_device *sdev = to_siw_dev(base_cq->device);
        struct siw_cq *cq = to_siw_cq(base_cq);
        int rv, size = attr->cqe;

        if (attr->flags)
                return -EOPNOTSUPP;

        if (atomic_inc_return(&sdev->num_cq) > SIW_MAX_CQ) {
                siw_dbg(base_cq->device, "too many CQ's\n");
                rv = -ENOMEM;
                goto err_out;
        }
        if (size < 1 || size > sdev->attrs.max_cqe) {
                siw_dbg(base_cq->device, "CQ size error: %d\n", size);
                rv = -EINVAL;
                goto err_out;
        }
        size = roundup_pow_of_two(size);
        cq->base_cq.cqe = size;
        cq->num_cqe = size;

        if (udata)
                cq->queue = vmalloc_user(size * sizeof(struct siw_cqe) +
                                         sizeof(struct siw_cq_ctrl));
        else
                cq->queue = vzalloc(size * sizeof(struct siw_cqe) +
                                    sizeof(struct siw_cq_ctrl));

        if (cq->queue == NULL) {
                rv = -ENOMEM;
                goto err_out;
        }
        get_random_bytes(&cq->id, 4);
        siw_dbg(base_cq->device, "new CQ [%u]\n", cq->id);

        spin_lock_init(&cq->lock);

        cq->notify = (struct siw_cq_ctrl *)&cq->queue[size];

        if (udata) {
                struct siw_uresp_create_cq uresp = {};
                struct siw_ucontext *ctx =
                        rdma_udata_to_drv_context(udata, struct siw_ucontext,
                                                  base_ucontext);
                size_t length = size * sizeof(struct siw_cqe) +
                        sizeof(struct siw_cq_ctrl);

                cq->cq_entry =
                        siw_mmap_entry_insert(ctx, cq->queue,
                                              length, &uresp.cq_key);
                if (!cq->cq_entry) {
                        rv = -ENOMEM;
                        goto err_out;
                }

                uresp.cq_id = cq->id;
                uresp.num_cqe = size;

                if (udata->outlen < sizeof(uresp)) {
                        rv = -EINVAL;
                        goto err_out;
                }
                rv = ib_copy_to_udata(udata, &uresp, sizeof(uresp));
                if (rv)
                        goto err_out;
        }
        return 0;

err_out:
        siw_dbg(base_cq->device, "CQ creation failed: %d", rv);

        if (cq && cq->queue) {
                struct siw_ucontext *ctx =
                        rdma_udata_to_drv_context(udata, struct siw_ucontext,
                                                  base_ucontext);
                if (ctx)
                        rdma_user_mmap_entry_remove(cq->cq_entry);
                vfree(cq->queue);
        }
        atomic_dec(&sdev->num_cq);

        return rv;
}

/*
 * siw_poll_cq()
 *
 * Reap CQ entries if available and copy work completion status into
 * array of WC's provided by caller. Returns number of reaped CQE's.
 *
 * @base_cq:    Base CQ contained in siw CQ.
 * @num_cqe:    Maximum number of CQE's to reap.
 * @wc:         Array of work completions to be filled by siw.
 */
int siw_poll_cq(struct ib_cq *base_cq, int num_cqe, struct ib_wc *wc)
{
        struct siw_cq *cq = to_siw_cq(base_cq);
        int i;

        for (i = 0; i < num_cqe; i++) {
                if (!siw_reap_cqe(cq, wc))
                        break;
                wc++;
        }
        return i;
}

/*
 * siw_req_notify_cq()
 *
 * Request notification for new CQE's added to that CQ.
 * Defined flags:
 * o SIW_CQ_NOTIFY_SOLICITED lets siw trigger a notification
 *   event if a WQE with notification flag set enters the CQ
 * o SIW_CQ_NOTIFY_NEXT_COMP lets siw trigger a notification
 *   event if a WQE enters the CQ.
 * o IB_CQ_REPORT_MISSED_EVENTS: return value will provide the
 *   number of not reaped CQE's regardless of its notification
 *   type and current or new CQ notification settings.
 *
 * @base_cq:    Base CQ contained in siw CQ.
 * @flags:      Requested notification flags.
 */
int siw_req_notify_cq(struct ib_cq *base_cq, enum ib_cq_notify_flags flags)
{
        struct siw_cq *cq = to_siw_cq(base_cq);

        siw_dbg_cq(cq, "flags: 0x%02x\n", flags);

        if ((flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED)
                /*
                 * Enable CQ event for next solicited completion.
                 * and make it visible to all associated producers.
                 */
                smp_store_mb(cq->notify->flags, SIW_NOTIFY_SOLICITED);
        else
                /*
                 * Enable CQ event for any signalled completion.
                 * and make it visible to all associated producers.
                 */
                smp_store_mb(cq->notify->flags, SIW_NOTIFY_ALL);

        if (flags & IB_CQ_REPORT_MISSED_EVENTS)
                return cq->cq_put - cq->cq_get;

        return 0;
}

/*
 * siw_dereg_mr()
 *
 * Release Memory Region.
 *
 * @base_mr: Base MR contained in siw MR.
 * @udata: points to user context, unused.
 */
int siw_dereg_mr(struct ib_mr *base_mr, struct ib_udata *udata)
{
        struct siw_mr *mr = to_siw_mr(base_mr);
        struct siw_device *sdev = to_siw_dev(base_mr->device);

        siw_dbg_mem(mr->mem, "deregister MR\n");

        atomic_dec(&sdev->num_mr);

        siw_mr_drop_mem(mr);
        kfree_rcu(mr, rcu);

        return 0;
}

/*
 * siw_reg_user_mr()
 *
 * Register Memory Region.
 *
 * @pd:         Protection Domain
 * @start:      starting address of MR (virtual address)
 * @len:        len of MR
 * @rnic_va:    not used by siw
 * @rights:     MR access rights
 * @udata:      user buffer to communicate STag and Key.
 */
struct ib_mr *siw_reg_user_mr(struct ib_pd *pd, u64 start, u64 len,
                              u64 rnic_va, int rights, struct ib_udata *udata)
{
        struct siw_mr *mr = NULL;
        struct siw_umem *umem = NULL;
        struct siw_ureq_reg_mr ureq;
        struct siw_device *sdev = to_siw_dev(pd->device);

        unsigned long mem_limit = rlimit(RLIMIT_MEMLOCK);
        int rv;

        siw_dbg_pd(pd, "start: 0x%pK, va: 0x%pK, len: %llu\n",
                   (void *)(uintptr_t)start, (void *)(uintptr_t)rnic_va,
                   (unsigned long long)len);

        if (atomic_inc_return(&sdev->num_mr) > SIW_MAX_MR) {
                siw_dbg_pd(pd, "too many mr's\n");
                rv = -ENOMEM;
                goto err_out;
        }
        if (!len) {
                rv = -EINVAL;
                goto err_out;
        }
        if (mem_limit != RLIM_INFINITY) {
                unsigned long num_pages =
                        (PAGE_ALIGN(len + (start & ~PAGE_MASK))) >> PAGE_SHIFT;
                mem_limit >>= PAGE_SHIFT;

                if (num_pages > mem_limit - current->mm->locked_vm) {
                        siw_dbg_pd(pd, "pages req %lu, max %lu, lock %lu\n",
                                   num_pages, mem_limit,
                                   current->mm->locked_vm);
                        rv = -ENOMEM;
                        goto err_out;
                }
        }
        umem = siw_umem_get(start, len, ib_access_writable(rights));
        if (IS_ERR(umem)) {
                rv = PTR_ERR(umem);
                siw_dbg_pd(pd, "getting user memory failed: %d\n", rv);
                umem = NULL;
                goto err_out;
        }
        mr = kzalloc(sizeof(*mr), GFP_KERNEL);
        if (!mr) {
                rv = -ENOMEM;
                goto err_out;
        }
        rv = siw_mr_add_mem(mr, pd, umem, start, len, rights);
        if (rv)
                goto err_out;

        if (udata) {
                struct siw_uresp_reg_mr uresp = {};
                struct siw_mem *mem = mr->mem;

                if (udata->inlen < sizeof(ureq)) {
                        rv = -EINVAL;
                        goto err_out;
                }
                rv = ib_copy_from_udata(&ureq, udata, sizeof(ureq));
                if (rv)
                        goto err_out;

                mr->base_mr.lkey |= ureq.stag_key;
                mr->base_mr.rkey |= ureq.stag_key;
                mem->stag |= ureq.stag_key;
                uresp.stag = mem->stag;

                if (udata->outlen < sizeof(uresp)) {
                        rv = -EINVAL;
                        goto err_out;
                }
                rv = ib_copy_to_udata(udata, &uresp, sizeof(uresp));
                if (rv)
                        goto err_out;
        }
        mr->mem->stag_valid = 1;

        return &mr->base_mr;

err_out:
        atomic_dec(&sdev->num_mr);
        if (mr) {
                if (mr->mem)
                        siw_mr_drop_mem(mr);
                kfree_rcu(mr, rcu);
        } else {
                if (umem)
                        siw_umem_release(umem, false);
        }
        return ERR_PTR(rv);
}

struct ib_mr *siw_alloc_mr(struct ib_pd *pd, enum ib_mr_type mr_type,
                           u32 max_sge)
{
        struct siw_device *sdev = to_siw_dev(pd->device);
        struct siw_mr *mr = NULL;
        struct siw_pbl *pbl = NULL;
        int rv;

        if (atomic_inc_return(&sdev->num_mr) > SIW_MAX_MR) {
                siw_dbg_pd(pd, "too many mr's\n");
                rv = -ENOMEM;
                goto err_out;
        }
        if (mr_type != IB_MR_TYPE_MEM_REG) {
                siw_dbg_pd(pd, "mr type %d unsupported\n", mr_type);
                rv = -EOPNOTSUPP;
                goto err_out;
        }
        if (max_sge > SIW_MAX_SGE_PBL) {
                siw_dbg_pd(pd, "too many sge's: %d\n", max_sge);
                rv = -ENOMEM;
                goto err_out;
        }
        pbl = siw_pbl_alloc(max_sge);
        if (IS_ERR(pbl)) {
                rv = PTR_ERR(pbl);
                siw_dbg_pd(pd, "pbl allocation failed: %d\n", rv);
                pbl = NULL;
                goto err_out;
        }
        mr = kzalloc(sizeof(*mr), GFP_KERNEL);
        if (!mr) {
                rv = -ENOMEM;
                goto err_out;
        }
        rv = siw_mr_add_mem(mr, pd, pbl, 0, max_sge * PAGE_SIZE, 0);
        if (rv)
                goto err_out;

        mr->mem->is_pbl = 1;

        siw_dbg_pd(pd, "[MEM %u]: success\n", mr->mem->stag);

        return &mr->base_mr;

err_out:
        atomic_dec(&sdev->num_mr);

        if (!mr) {
                kfree(pbl);
        } else {
                if (mr->mem)
                        siw_mr_drop_mem(mr);
                kfree_rcu(mr, rcu);
        }
        siw_dbg_pd(pd, "failed: %d\n", rv);

        return ERR_PTR(rv);
}

/* Just used to count number of pages being mapped */
static int siw_set_pbl_page(struct ib_mr *base_mr, u64 buf_addr)
{
        return 0;
}

int siw_map_mr_sg(struct ib_mr *base_mr, struct scatterlist *sl, int num_sle,
                  unsigned int *sg_off)
{
        struct scatterlist *slp;
        struct siw_mr *mr = to_siw_mr(base_mr);
        struct siw_mem *mem = mr->mem;
        struct siw_pbl *pbl = mem->pbl;
        struct siw_pble *pble;
        unsigned long pbl_size;
        int i, rv;

        if (!pbl) {
                siw_dbg_mem(mem, "no PBL allocated\n");
                return -EINVAL;
        }
        pble = pbl->pbe;

        if (pbl->max_buf < num_sle) {
                siw_dbg_mem(mem, "too many SGE's: %d > %d\n",
                            mem->pbl->max_buf, num_sle);
                return -ENOMEM;
        }
        for_each_sg(sl, slp, num_sle, i) {
                if (sg_dma_len(slp) == 0) {
                        siw_dbg_mem(mem, "empty SGE\n");
                        return -EINVAL;
                }
                if (i == 0) {
                        pble->addr = sg_dma_address(slp);
                        pble->size = sg_dma_len(slp);
                        pble->pbl_off = 0;
                        pbl_size = pble->size;
                        pbl->num_buf = 1;
                } else {
                        /* Merge PBL entries if adjacent */
                        if (pble->addr + pble->size == sg_dma_address(slp)) {
                                pble->size += sg_dma_len(slp);
                        } else {
                                pble++;
                                pbl->num_buf++;
                                pble->addr = sg_dma_address(slp);
                                pble->size = sg_dma_len(slp);
                                pble->pbl_off = pbl_size;
                        }
                        pbl_size += sg_dma_len(slp);
                }
                siw_dbg_mem(mem,
                        "sge[%d], size %u, addr 0x%p, total %lu\n",
                        i, pble->size, (void *)(uintptr_t)pble->addr,
                        pbl_size);
        }
        rv = ib_sg_to_pages(base_mr, sl, num_sle, sg_off, siw_set_pbl_page);
        if (rv > 0) {
                mem->len = base_mr->length;
                mem->va = base_mr->iova;
                siw_dbg_mem(mem,
                        "%llu bytes, start 0x%pK, %u SLE to %u entries\n",
                        mem->len, (void *)(uintptr_t)mem->va, num_sle,
                        pbl->num_buf);
        }
        return rv;
}

/*
 * siw_get_dma_mr()
 *
 * Create a (empty) DMA memory region, where no umem is attached.
 */
struct ib_mr *siw_get_dma_mr(struct ib_pd *pd, int rights)
{
        struct siw_device *sdev = to_siw_dev(pd->device);
        struct siw_mr *mr = NULL;
        int rv;

        if (atomic_inc_return(&sdev->num_mr) > SIW_MAX_MR) {
                siw_dbg_pd(pd, "too many mr's\n");
                rv = -ENOMEM;
                goto err_out;
        }
        mr = kzalloc(sizeof(*mr), GFP_KERNEL);
        if (!mr) {
                rv = -ENOMEM;
                goto err_out;
        }
        rv = siw_mr_add_mem(mr, pd, NULL, 0, ULONG_MAX, rights);
        if (rv)
                goto err_out;

        mr->mem->stag_valid = 1;

        siw_dbg_pd(pd, "[MEM %u]: success\n", mr->mem->stag);

        return &mr->base_mr;

err_out:
        if (rv)
                kfree(mr);

        atomic_dec(&sdev->num_mr);

        return ERR_PTR(rv);
}

/*
 * siw_create_srq()
 *
 * Create Shared Receive Queue of attributes @init_attrs
 * within protection domain given by @pd.
 *
 * @base_srq:   Base SRQ contained in siw SRQ.
 * @init_attrs: SRQ init attributes.
 * @udata:      points to user context
 */
int siw_create_srq(struct ib_srq *base_srq,
                   struct ib_srq_init_attr *init_attrs, struct ib_udata *udata)
{
        struct siw_srq *srq = to_siw_srq(base_srq);
        struct ib_srq_attr *attrs = &init_attrs->attr;
        struct siw_device *sdev = to_siw_dev(base_srq->device);
        struct siw_ucontext *ctx =
                rdma_udata_to_drv_context(udata, struct siw_ucontext,
                                          base_ucontext);
        int rv;

        if (init_attrs->srq_type != IB_SRQT_BASIC)
                return -EOPNOTSUPP;

        if (atomic_inc_return(&sdev->num_srq) > SIW_MAX_SRQ) {
                siw_dbg_pd(base_srq->pd, "too many SRQ's\n");
                rv = -ENOMEM;
                goto err_out;
        }
        if (attrs->max_wr == 0 || attrs->max_wr > SIW_MAX_SRQ_WR ||
            attrs->max_sge > SIW_MAX_SGE || attrs->srq_limit > attrs->max_wr) {
                rv = -EINVAL;
                goto err_out;
        }
        srq->max_sge = attrs->max_sge;
        srq->num_rqe = roundup_pow_of_two(attrs->max_wr);
        srq->limit = attrs->srq_limit;
        if (srq->limit)
                srq->armed = true;

        srq->is_kernel_res = !udata;

        if (udata)
                srq->recvq =
                        vmalloc_user(srq->num_rqe * sizeof(struct siw_rqe));
        else
                srq->recvq = vzalloc(srq->num_rqe * sizeof(struct siw_rqe));

        if (srq->recvq == NULL) {
                rv = -ENOMEM;
                goto err_out;
        }
        if (udata) {
                struct siw_uresp_create_srq uresp = {};
                size_t length = srq->num_rqe * sizeof(struct siw_rqe);

                srq->srq_entry =
                        siw_mmap_entry_insert(ctx, srq->recvq,
                                              length, &uresp.srq_key);
                if (!srq->srq_entry) {
                        rv = -ENOMEM;
                        goto err_out;
                }

                uresp.num_rqe = srq->num_rqe;

                if (udata->outlen < sizeof(uresp)) {
                        rv = -EINVAL;
                        goto err_out;
                }
                rv = ib_copy_to_udata(udata, &uresp, sizeof(uresp));
                if (rv)
                        goto err_out;
        }
        spin_lock_init(&srq->lock);

        siw_dbg_pd(base_srq->pd, "[SRQ]: success\n");

        return 0;

err_out:
        if (srq->recvq) {
                if (ctx)
                        rdma_user_mmap_entry_remove(srq->srq_entry);
                vfree(srq->recvq);
        }
        atomic_dec(&sdev->num_srq);

        return rv;
}

/*
 * siw_modify_srq()
 *
 * Modify SRQ. The caller may resize SRQ and/or set/reset notification
 * limit and (re)arm IB_EVENT_SRQ_LIMIT_REACHED notification.
 *
 * NOTE: it is unclear if RDMA core allows for changing the MAX_SGE
 * parameter. siw_modify_srq() does not check the attrs->max_sge param.
 */
int siw_modify_srq(struct ib_srq *base_srq, struct ib_srq_attr *attrs,
                   enum ib_srq_attr_mask attr_mask, struct ib_udata *udata)
{
        struct siw_srq *srq = to_siw_srq(base_srq);
        unsigned long flags;
        int rv = 0;

        spin_lock_irqsave(&srq->lock, flags);

        if (attr_mask & IB_SRQ_MAX_WR) {
                /* resize request not yet supported */
                rv = -EOPNOTSUPP;
                goto out;
        }
        if (attr_mask & IB_SRQ_LIMIT) {
                if (attrs->srq_limit) {
                        if (unlikely(attrs->srq_limit > srq->num_rqe)) {
                                rv = -EINVAL;
                                goto out;
                        }
                        srq->armed = true;
                } else {
                        srq->armed = false;
                }
                srq->limit = attrs->srq_limit;
        }
out:
        spin_unlock_irqrestore(&srq->lock, flags);

        return rv;
}

/*
 * siw_query_srq()
 *
 * Query SRQ attributes.
 */
int siw_query_srq(struct ib_srq *base_srq, struct ib_srq_attr *attrs)
{
        struct siw_srq *srq = to_siw_srq(base_srq);
        unsigned long flags;

        spin_lock_irqsave(&srq->lock, flags);

        attrs->max_wr = srq->num_rqe;
        attrs->max_sge = srq->max_sge;
        attrs->srq_limit = srq->limit;

        spin_unlock_irqrestore(&srq->lock, flags);

        return 0;
}

/*
 * siw_destroy_srq()
 *
 * Destroy SRQ.
 * It is assumed that the SRQ is not referenced by any
 * QP anymore - the code trusts the RDMA core environment to keep track
 * of QP references.
 */
int siw_destroy_srq(struct ib_srq *base_srq, struct ib_udata *udata)
{
        struct siw_srq *srq = to_siw_srq(base_srq);
        struct siw_device *sdev = to_siw_dev(base_srq->device);
        struct siw_ucontext *ctx =
                rdma_udata_to_drv_context(udata, struct siw_ucontext,
                                          base_ucontext);

        if (ctx)
                rdma_user_mmap_entry_remove(srq->srq_entry);
        vfree(srq->recvq);
        atomic_dec(&sdev->num_srq);
        return 0;
}

/*
 * siw_post_srq_recv()
 *
 * Post a list of receive queue elements to SRQ.
 * NOTE: The function does not check or lock a certain SRQ state
 *       during the post operation. The code simply trusts the
 *       RDMA core environment.
 *
 * @base_srq:   Base SRQ contained in siw SRQ
 * @wr:         List of R-WR's
 * @bad_wr:     Updated to failing WR if posting fails.
 */
int siw_post_srq_recv(struct ib_srq *base_srq, const struct ib_recv_wr *wr,
                      const struct ib_recv_wr **bad_wr)
{
        struct siw_srq *srq = to_siw_srq(base_srq);
        unsigned long flags;
        int rv = 0;

        if (unlikely(!srq->is_kernel_res)) {
                siw_dbg_pd(base_srq->pd,
                           "[SRQ]: no kernel post_recv for mapped srq\n");
                rv = -EINVAL;
                goto out;
        }
        /*
         * Serialize potentially multiple producers.
         * Also needed to serialize potentially multiple
         * consumers.
         */
        spin_lock_irqsave(&srq->lock, flags);

        while (wr) {
                u32 idx = srq->rq_put % srq->num_rqe;
                struct siw_rqe *rqe = &srq->recvq[idx];

                if (rqe->flags) {
                        siw_dbg_pd(base_srq->pd, "SRQ full\n");
                        rv = -ENOMEM;
                        break;
                }
                if (unlikely(wr->num_sge > srq->max_sge)) {
                        siw_dbg_pd(base_srq->pd,
                                   "[SRQ]: too many sge's: %d\n", wr->num_sge);
                        rv = -EINVAL;
                        break;
                }
                rqe->id = wr->wr_id;
                rqe->num_sge = wr->num_sge;
                siw_copy_sgl(wr->sg_list, rqe->sge, wr->num_sge);

                /* Make sure S-RQE is completely written before valid */
                smp_wmb();

                rqe->flags = SIW_WQE_VALID;

                srq->rq_put++;
                wr = wr->next;
        }
        spin_unlock_irqrestore(&srq->lock, flags);
out:
        if (unlikely(rv < 0)) {
                siw_dbg_pd(base_srq->pd, "[SRQ]: error %d\n", rv);
                *bad_wr = wr;
        }
        return rv;
}

void siw_qp_event(struct siw_qp *qp, enum ib_event_type etype)
{
        struct ib_event event;
        struct ib_qp *base_qp = &qp->base_qp;

        /*
         * Do not report asynchronous errors on QP which gets
         * destroyed via verbs interface (siw_destroy_qp())
         */
        if (qp->attrs.flags & SIW_QP_IN_DESTROY)
                return;

        event.event = etype;
        event.device = base_qp->device;
        event.element.qp = base_qp;

        if (base_qp->event_handler) {
                siw_dbg_qp(qp, "reporting event %d\n", etype);
                base_qp->event_handler(&event, base_qp->qp_context);
        }
}

void siw_cq_event(struct siw_cq *cq, enum ib_event_type etype)
{
        struct ib_event event;
        struct ib_cq *base_cq = &cq->base_cq;

        event.event = etype;
        event.device = base_cq->device;
        event.element.cq = base_cq;

        if (base_cq->event_handler) {
                siw_dbg_cq(cq, "reporting CQ event %d\n", etype);
                base_cq->event_handler(&event, base_cq->cq_context);
        }
}

void siw_srq_event(struct siw_srq *srq, enum ib_event_type etype)
{
        struct ib_event event;
        struct ib_srq *base_srq = &srq->base_srq;

        event.event = etype;
        event.device = base_srq->device;
        event.element.srq = base_srq;

        if (base_srq->event_handler) {
                siw_dbg_pd(srq->base_srq.pd,
                           "reporting SRQ event %d\n", etype);
                base_srq->event_handler(&event, base_srq->srq_context);
        }
}

void siw_port_event(struct siw_device *sdev, u32 port, enum ib_event_type etype)
{
        struct ib_event event;

        event.event = etype;
        event.device = &sdev->base_dev;
        event.element.port_num = port;

        siw_dbg(&sdev->base_dev, "reporting port event %d\n", etype);

        ib_dispatch_event(&event);
}