// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
 * Copyright(c) 2016 Intel Corporation.
 */

#include <linux/err.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <rdma/uverbs_ioctl.h>

#include "srq.h"
#include "vt.h"
#include "qp.h"
/**
 * rvt_driver_srq_init - init srq resources on a per driver basis
 * @rdi: rvt dev structure
 *
 * Do any initialization needed when a driver registers with rdmavt.
 */
void rvt_driver_srq_init(struct rvt_dev_info *rdi)
{
        spin_lock_init(&rdi->n_srqs_lock);
        rdi->n_srqs_allocated = 0;
}

/**
 * rvt_create_srq - create a shared receive queue
 * @ibsrq: the protection domain of the SRQ to create
 * @srq_init_attr: the attributes of the SRQ
 * @udata: data from libibverbs when creating a user SRQ
 *
 * Return: 0 on success
 */
int rvt_create_srq(struct ib_srq *ibsrq, struct ib_srq_init_attr *srq_init_attr,
                   struct ib_udata *udata)
{
        struct rvt_dev_info *dev = ib_to_rvt(ibsrq->device);
        struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);
        u32 sz;
        int ret;

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

        if (srq_init_attr->attr.max_sge == 0 ||
            srq_init_attr->attr.max_sge > dev->dparms.props.max_srq_sge ||
            srq_init_attr->attr.max_wr == 0 ||
            srq_init_attr->attr.max_wr > dev->dparms.props.max_srq_wr)
                return -EINVAL;

        /*
         * Need to use vmalloc() if we want to support large #s of entries.
         */
        srq->rq.size = srq_init_attr->attr.max_wr + 1;
        srq->rq.max_sge = srq_init_attr->attr.max_sge;
        sz = sizeof(struct ib_sge) * srq->rq.max_sge +
                sizeof(struct rvt_rwqe);
        if (rvt_alloc_rq(&srq->rq, srq->rq.size * sz,
                         dev->dparms.node, udata)) {
                ret = -ENOMEM;
                goto bail_srq;
        }

        /*
         * Return the address of the RWQ as the offset to mmap.
         * See rvt_mmap() for details.
         */
        if (udata && udata->outlen >= sizeof(__u64)) {
                u32 s = sizeof(struct rvt_rwq) + srq->rq.size * sz;

                srq->ip = rvt_create_mmap_info(dev, s, udata, srq->rq.wq);
                if (IS_ERR(srq->ip)) {
                        ret = PTR_ERR(srq->ip);
                        goto bail_wq;
                }

                ret = ib_copy_to_udata(udata, &srq->ip->offset,
                                       sizeof(srq->ip->offset));
                if (ret)
                        goto bail_ip;
        }

        /*
         * ib_create_srq() will initialize srq->ibsrq.
         */
        spin_lock_init(&srq->rq.lock);
        srq->limit = srq_init_attr->attr.srq_limit;

        spin_lock(&dev->n_srqs_lock);
        if (dev->n_srqs_allocated == dev->dparms.props.max_srq) {
                spin_unlock(&dev->n_srqs_lock);
                ret = -ENOMEM;
                goto bail_ip;
        }

        dev->n_srqs_allocated++;
        spin_unlock(&dev->n_srqs_lock);

        if (srq->ip) {
                spin_lock_irq(&dev->pending_lock);
                list_add(&srq->ip->pending_mmaps, &dev->pending_mmaps);
                spin_unlock_irq(&dev->pending_lock);
        }

        return 0;

bail_ip:
        kfree(srq->ip);
bail_wq:
        rvt_free_rq(&srq->rq);
bail_srq:
        return ret;
}

/**
 * rvt_modify_srq - modify a shared receive queue
 * @ibsrq: the SRQ to modify
 * @attr: the new attributes of the SRQ
 * @attr_mask: indicates which attributes to modify
 * @udata: user data for libibverbs.so
 *
 * Return: 0 on success
 */
int rvt_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
                   enum ib_srq_attr_mask attr_mask,
                   struct ib_udata *udata)
{
        struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);
        struct rvt_dev_info *dev = ib_to_rvt(ibsrq->device);
        struct rvt_rq tmp_rq = {};
        int ret = 0;

        if (attr_mask & IB_SRQ_MAX_WR) {
                struct rvt_krwq *okwq = NULL;
                struct rvt_rwq *owq = NULL;
                struct rvt_rwqe *p;
                u32 sz, size, n, head, tail;

                /* Check that the requested sizes are below the limits. */
                if ((attr->max_wr > dev->dparms.props.max_srq_wr) ||
                    ((attr_mask & IB_SRQ_LIMIT) ?
                     attr->srq_limit : srq->limit) > attr->max_wr)
                        return -EINVAL;
                sz = sizeof(struct rvt_rwqe) +
                        srq->rq.max_sge * sizeof(struct ib_sge);
                size = attr->max_wr + 1;
                if (rvt_alloc_rq(&tmp_rq, size * sz, dev->dparms.node,
                                 udata))
                        return -ENOMEM;
                /* Check that we can write the offset to mmap. */
                if (udata && udata->inlen >= sizeof(__u64)) {
                        __u64 offset_addr;
                        __u64 offset = 0;

                        ret = ib_copy_from_udata(&offset_addr, udata,
                                                 sizeof(offset_addr));
                        if (ret)
                                goto bail_free;
                        udata->outbuf = (void __user *)
                                        (unsigned long)offset_addr;
                        ret = ib_copy_to_udata(udata, &offset,
                                               sizeof(offset));
                        if (ret)
                                goto bail_free;
                }

                spin_lock_irq(&srq->rq.kwq->c_lock);
                /*
                 * validate head and tail pointer values and compute
                 * the number of remaining WQEs.
                 */
                if (udata) {
                        owq = srq->rq.wq;
                        head = RDMA_READ_UAPI_ATOMIC(owq->head);
                        tail = RDMA_READ_UAPI_ATOMIC(owq->tail);
                } else {
                        okwq = srq->rq.kwq;
                        head = okwq->head;
                        tail = okwq->tail;
                }
                if (head >= srq->rq.size || tail >= srq->rq.size) {
                        ret = -EINVAL;
                        goto bail_unlock;
                }
                n = head;
                if (n < tail)
                        n += srq->rq.size - tail;
                else
                        n -= tail;
                if (size <= n) {
                        ret = -EINVAL;
                        goto bail_unlock;
                }
                n = 0;
                p = tmp_rq.kwq->curr_wq;
                while (tail != head) {
                        struct rvt_rwqe *wqe;
                        int i;

                        wqe = rvt_get_rwqe_ptr(&srq->rq, tail);
                        p->wr_id = wqe->wr_id;
                        p->num_sge = wqe->num_sge;
                        for (i = 0; i < wqe->num_sge; i++)
                                p->sg_list[i] = wqe->sg_list[i];
                        n++;
                        p = (struct rvt_rwqe *)((char *)p + sz);
                        if (++tail >= srq->rq.size)
                                tail = 0;
                }
                srq->rq.kwq = tmp_rq.kwq;
                if (udata) {
                        srq->rq.wq = tmp_rq.wq;
                        RDMA_WRITE_UAPI_ATOMIC(tmp_rq.wq->head, n);
                        RDMA_WRITE_UAPI_ATOMIC(tmp_rq.wq->tail, 0);
                } else {
                        tmp_rq.kwq->head = n;
                        tmp_rq.kwq->tail = 0;
                }
                srq->rq.size = size;
                if (attr_mask & IB_SRQ_LIMIT)
                        srq->limit = attr->srq_limit;
                spin_unlock_irq(&srq->rq.kwq->c_lock);

                vfree(owq);
                kvfree(okwq);

                if (srq->ip) {
                        struct rvt_mmap_info *ip = srq->ip;
                        struct rvt_dev_info *dev = ib_to_rvt(srq->ibsrq.device);
                        u32 s = sizeof(struct rvt_rwq) + size * sz;

                        rvt_update_mmap_info(dev, ip, s, tmp_rq.wq);

                        /*
                         * Return the offset to mmap.
                         * See rvt_mmap() for details.
                         */
                        if (udata && udata->inlen >= sizeof(__u64)) {
                                ret = ib_copy_to_udata(udata, &ip->offset,
                                                       sizeof(ip->offset));
                                if (ret)
                                        return ret;
                        }

                        /*
                         * Put user mapping info onto the pending list
                         * unless it already is on the list.
                         */
                        spin_lock_irq(&dev->pending_lock);
                        if (list_empty(&ip->pending_mmaps))
                                list_add(&ip->pending_mmaps,
                                         &dev->pending_mmaps);
                        spin_unlock_irq(&dev->pending_lock);
                }
        } else if (attr_mask & IB_SRQ_LIMIT) {
                spin_lock_irq(&srq->rq.kwq->c_lock);
                if (attr->srq_limit >= srq->rq.size)
                        ret = -EINVAL;
                else
                        srq->limit = attr->srq_limit;
                spin_unlock_irq(&srq->rq.kwq->c_lock);
        }
        return ret;

bail_unlock:
        spin_unlock_irq(&srq->rq.kwq->c_lock);
bail_free:
        rvt_free_rq(&tmp_rq);
        return ret;
}

/**
 * rvt_query_srq - query srq data
 * @ibsrq: srq to query
 * @attr: return info in attr
 *
 * Return: always 0
 */
int rvt_query_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr)
{
        struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);

        attr->max_wr = srq->rq.size - 1;
        attr->max_sge = srq->rq.max_sge;
        attr->srq_limit = srq->limit;
        return 0;
}

/**
 * rvt_destroy_srq - destory an srq
 * @ibsrq: srq object to destroy
 * @udata: user data for libibverbs.so
 */
int rvt_destroy_srq(struct ib_srq *ibsrq, struct ib_udata *udata)
{
        struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);
        struct rvt_dev_info *dev = ib_to_rvt(ibsrq->device);

        spin_lock(&dev->n_srqs_lock);
        dev->n_srqs_allocated--;
        spin_unlock(&dev->n_srqs_lock);
        if (srq->ip)
                kref_put(&srq->ip->ref, rvt_release_mmap_info);
        kvfree(srq->rq.kwq);
        return 0;
}