root/drivers/infiniband/hw/mlx5/srq.c
// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/*
 * Copyright (c) 2013-2018, Mellanox Technologies inc.  All rights reserved.
 */

#include <linux/mlx5/qp.h>
#include <linux/slab.h>
#include <rdma/ib_umem.h>
#include <rdma/ib_user_verbs.h>
#include "mlx5_ib.h"
#include "srq.h"

static void *get_wqe(struct mlx5_ib_srq *srq, int n)
{
        return mlx5_frag_buf_get_wqe(&srq->fbc, n);
}

static void mlx5_ib_srq_event(struct mlx5_core_srq *srq, enum mlx5_event type)
{
        struct ib_event event;
        struct ib_srq *ibsrq = &to_mibsrq(srq)->ibsrq;

        if (ibsrq->event_handler) {
                event.device      = ibsrq->device;
                event.element.srq = ibsrq;
                switch (type) {
                case MLX5_EVENT_TYPE_SRQ_RQ_LIMIT:
                        event.event = IB_EVENT_SRQ_LIMIT_REACHED;
                        break;
                case MLX5_EVENT_TYPE_SRQ_CATAS_ERROR:
                        event.event = IB_EVENT_SRQ_ERR;
                        break;
                default:
                        pr_warn("mlx5_ib: Unexpected event type %d on SRQ %06x\n",
                                type, srq->srqn);
                        return;
                }

                ibsrq->event_handler(&event, ibsrq->srq_context);
        }
}

static int create_srq_user(struct ib_pd *pd, struct mlx5_ib_srq *srq,
                           struct mlx5_srq_attr *in,
                           struct ib_udata *udata, int buf_size)
{
        struct mlx5_ib_dev *dev = to_mdev(pd->device);
        struct mlx5_ib_create_srq ucmd = {};
        struct mlx5_ib_ucontext *ucontext = rdma_udata_to_drv_context(
                udata, struct mlx5_ib_ucontext, ibucontext);
        size_t ucmdlen;
        int err;
        u32 uidx = MLX5_IB_DEFAULT_UIDX;

        ucmdlen = min(udata->inlen, sizeof(ucmd));

        if (ib_copy_from_udata(&ucmd, udata, ucmdlen)) {
                mlx5_ib_dbg(dev, "failed copy udata\n");
                return -EFAULT;
        }

        if (ucmd.reserved0 || ucmd.reserved1)
                return -EINVAL;

        if (udata->inlen > sizeof(ucmd) &&
            !ib_is_udata_cleared(udata, sizeof(ucmd),
                                 udata->inlen - sizeof(ucmd)))
                return -EINVAL;

        if (in->type != IB_SRQT_BASIC) {
                err = get_srq_user_index(ucontext, &ucmd, udata->inlen, &uidx);
                if (err)
                        return err;
        }

        srq->wq_sig = !!(ucmd.flags & MLX5_SRQ_FLAG_SIGNATURE);

        srq->umem = ib_umem_get(pd->device, ucmd.buf_addr, buf_size, 0);
        if (IS_ERR(srq->umem)) {
                mlx5_ib_dbg(dev, "failed umem get, size %d\n", buf_size);
                err = PTR_ERR(srq->umem);
                return err;
        }
        in->umem = srq->umem;

        err = mlx5_ib_db_map_user(ucontext, ucmd.db_addr, &srq->db);
        if (err) {
                mlx5_ib_dbg(dev, "map doorbell failed\n");
                goto err_umem;
        }

        in->uid = (in->type != IB_SRQT_XRC) ?  to_mpd(pd)->uid : 0;
        if (MLX5_CAP_GEN(dev->mdev, cqe_version) == MLX5_CQE_VERSION_V1 &&
            in->type != IB_SRQT_BASIC)
                in->user_index = uidx;

        return 0;

err_umem:
        ib_umem_release(srq->umem);

        return err;
}

static int create_srq_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_srq *srq,
                             struct mlx5_srq_attr *in, int buf_size)
{
        int err;
        int i;
        struct mlx5_wqe_srq_next_seg *next;

        err = mlx5_db_alloc(dev->mdev, &srq->db);
        if (err) {
                mlx5_ib_warn(dev, "alloc dbell rec failed\n");
                return err;
        }

        if (mlx5_frag_buf_alloc_node(dev->mdev, buf_size, &srq->buf,
                                     dev->mdev->priv.numa_node)) {
                mlx5_ib_dbg(dev, "buf alloc failed\n");
                err = -ENOMEM;
                goto err_db;
        }

        mlx5_init_fbc(srq->buf.frags, srq->msrq.wqe_shift, ilog2(srq->msrq.max),
                      &srq->fbc);

        srq->head    = 0;
        srq->tail    = srq->msrq.max - 1;
        srq->wqe_ctr = 0;

        for (i = 0; i < srq->msrq.max; i++) {
                next = get_wqe(srq, i);
                next->next_wqe_index =
                        cpu_to_be16((i + 1) & (srq->msrq.max - 1));
        }

        mlx5_ib_dbg(dev, "srq->buf.page_shift = %d\n", srq->buf.page_shift);
        in->pas = kvcalloc(srq->buf.npages, sizeof(*in->pas), GFP_KERNEL);
        if (!in->pas) {
                err = -ENOMEM;
                goto err_buf;
        }
        mlx5_fill_page_frag_array(&srq->buf, in->pas);

        srq->wrid = kvmalloc_array(srq->msrq.max, sizeof(u64), GFP_KERNEL);
        if (!srq->wrid) {
                err = -ENOMEM;
                goto err_in;
        }
        srq->wq_sig = 0;

        in->log_page_size = srq->buf.page_shift - MLX5_ADAPTER_PAGE_SHIFT;
        if (MLX5_CAP_GEN(dev->mdev, cqe_version) == MLX5_CQE_VERSION_V1 &&
            in->type != IB_SRQT_BASIC)
                in->user_index = MLX5_IB_DEFAULT_UIDX;

        return 0;

err_in:
        kvfree(in->pas);

err_buf:
        mlx5_frag_buf_free(dev->mdev, &srq->buf);

err_db:
        mlx5_db_free(dev->mdev, &srq->db);
        return err;
}

static void destroy_srq_user(struct ib_pd *pd, struct mlx5_ib_srq *srq,
                             struct ib_udata *udata)
{
        mlx5_ib_db_unmap_user(
                rdma_udata_to_drv_context(
                        udata,
                        struct mlx5_ib_ucontext,
                        ibucontext),
                &srq->db);
        ib_umem_release(srq->umem);
}


static void destroy_srq_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_srq *srq)
{
        kvfree(srq->wrid);
        mlx5_frag_buf_free(dev->mdev, &srq->buf);
        mlx5_db_free(dev->mdev, &srq->db);
}

int mlx5_ib_create_srq(struct ib_srq *ib_srq,
                       struct ib_srq_init_attr *init_attr,
                       struct ib_udata *udata)
{
        struct mlx5_ib_dev *dev = to_mdev(ib_srq->device);
        struct mlx5_ib_srq *srq = to_msrq(ib_srq);
        size_t desc_size;
        size_t buf_size;
        int err;
        struct mlx5_srq_attr in = {};
        __u32 max_srq_wqes = 1 << MLX5_CAP_GEN(dev->mdev, log_max_srq_sz);
        __u32 max_sge_sz =  MLX5_CAP_GEN(dev->mdev, max_wqe_sz_rq) /
                            sizeof(struct mlx5_wqe_data_seg);

        if (init_attr->srq_type != IB_SRQT_BASIC &&
            init_attr->srq_type != IB_SRQT_XRC &&
            init_attr->srq_type != IB_SRQT_TM)
                return -EOPNOTSUPP;

        /* Sanity check SRQ and sge size before proceeding */
        if (init_attr->attr.max_wr >= max_srq_wqes ||
            init_attr->attr.max_sge > max_sge_sz) {
                mlx5_ib_dbg(dev, "max_wr %d,wr_cap %d,max_sge %d, sge_cap:%d\n",
                            init_attr->attr.max_wr, max_srq_wqes,
                            init_attr->attr.max_sge, max_sge_sz);
                return -EINVAL;
        }

        err = mlx5_ib_dev_res_cq_init(dev);
        if (err)
                return err;

        mutex_init(&srq->mutex);
        spin_lock_init(&srq->lock);
        srq->msrq.max    = roundup_pow_of_two(init_attr->attr.max_wr + 1);
        srq->msrq.max_gs = init_attr->attr.max_sge;

        desc_size = sizeof(struct mlx5_wqe_srq_next_seg) +
                    srq->msrq.max_gs * sizeof(struct mlx5_wqe_data_seg);
        if (desc_size == 0 || srq->msrq.max_gs > desc_size)
                return -EINVAL;

        desc_size = roundup_pow_of_two(desc_size);
        desc_size = max_t(size_t, 32, desc_size);
        if (desc_size < sizeof(struct mlx5_wqe_srq_next_seg))
                return -EINVAL;

        srq->msrq.max_avail_gather = (desc_size - sizeof(struct mlx5_wqe_srq_next_seg)) /
                sizeof(struct mlx5_wqe_data_seg);
        srq->msrq.wqe_shift = ilog2(desc_size);
        buf_size = srq->msrq.max * desc_size;
        if (buf_size < desc_size)
                return -EINVAL;

        in.type = init_attr->srq_type;

        if (udata)
                err = create_srq_user(ib_srq->pd, srq, &in, udata, buf_size);
        else
                err = create_srq_kernel(dev, srq, &in, buf_size);

        if (err) {
                mlx5_ib_warn(dev, "create srq %s failed, err %d\n",
                             udata ? "user" : "kernel", err);
                return err;
        }

        in.log_size = ilog2(srq->msrq.max);
        in.wqe_shift = srq->msrq.wqe_shift - 4;
        if (srq->wq_sig)
                in.flags |= MLX5_SRQ_FLAG_WQ_SIG;

        if (init_attr->srq_type == IB_SRQT_XRC && init_attr->ext.xrc.xrcd)
                in.xrcd = to_mxrcd(init_attr->ext.xrc.xrcd)->xrcdn;
        else
                in.xrcd = dev->devr.xrcdn0;

        if (init_attr->srq_type == IB_SRQT_TM) {
                in.tm_log_list_size =
                        ilog2(init_attr->ext.tag_matching.max_num_tags) + 1;
                if (in.tm_log_list_size >
                    MLX5_CAP_GEN(dev->mdev, log_tag_matching_list_sz)) {
                        mlx5_ib_dbg(dev, "TM SRQ max_num_tags exceeding limit\n");
                        err = -EINVAL;
                        goto err_usr_kern_srq;
                }
                in.flags |= MLX5_SRQ_FLAG_RNDV;
        }

        if (ib_srq_has_cq(init_attr->srq_type))
                in.cqn = to_mcq(init_attr->ext.cq)->mcq.cqn;
        else
                in.cqn = to_mcq(dev->devr.c0)->mcq.cqn;

        in.pd = to_mpd(ib_srq->pd)->pdn;
        in.db_record = srq->db.dma;
        err = mlx5_cmd_create_srq(dev, &srq->msrq, &in);
        kvfree(in.pas);
        if (err) {
                mlx5_ib_dbg(dev, "create SRQ failed, err %d\n", err);
                goto err_usr_kern_srq;
        }

        mlx5_ib_dbg(dev, "create SRQ with srqn 0x%x\n", srq->msrq.srqn);

        srq->msrq.event = mlx5_ib_srq_event;
        srq->ibsrq.ext.xrc.srq_num = srq->msrq.srqn;

        if (udata) {
                struct mlx5_ib_create_srq_resp resp = {
                        .srqn = srq->msrq.srqn,
                };

                if (ib_copy_to_udata(udata, &resp, min(udata->outlen,
                                     sizeof(resp)))) {
                        mlx5_ib_dbg(dev, "copy to user failed\n");
                        err = -EFAULT;
                        goto err_core;
                }
        }

        init_attr->attr.max_wr = srq->msrq.max - 1;

        return 0;

err_core:
        mlx5_cmd_destroy_srq(dev, &srq->msrq);

err_usr_kern_srq:
        if (udata)
                destroy_srq_user(ib_srq->pd, srq, udata);
        else
                destroy_srq_kernel(dev, srq);

        return err;
}

int mlx5_ib_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
                       enum ib_srq_attr_mask attr_mask, struct ib_udata *udata)
{
        struct mlx5_ib_dev *dev = to_mdev(ibsrq->device);
        struct mlx5_ib_srq *srq = to_msrq(ibsrq);
        int ret;

        /* We don't support resizing SRQs yet */
        if (attr_mask & IB_SRQ_MAX_WR)
                return -EINVAL;

        if (attr_mask & IB_SRQ_LIMIT) {
                if (attr->srq_limit >= srq->msrq.max)
                        return -EINVAL;

                mutex_lock(&srq->mutex);
                ret = mlx5_cmd_arm_srq(dev, &srq->msrq, attr->srq_limit, 1);
                mutex_unlock(&srq->mutex);

                if (ret)
                        return ret;
        }

        return 0;
}

int mlx5_ib_query_srq(struct ib_srq *ibsrq, struct ib_srq_attr *srq_attr)
{
        struct mlx5_ib_dev *dev = to_mdev(ibsrq->device);
        struct mlx5_ib_srq *srq = to_msrq(ibsrq);
        int ret;
        struct mlx5_srq_attr *out;

        out = kzalloc_obj(*out);
        if (!out)
                return -ENOMEM;

        ret = mlx5_cmd_query_srq(dev, &srq->msrq, out);
        if (ret)
                goto out_box;

        srq_attr->srq_limit = out->lwm;
        srq_attr->max_wr    = srq->msrq.max - 1;
        srq_attr->max_sge   = srq->msrq.max_gs;

out_box:
        kfree(out);
        return ret;
}

int mlx5_ib_destroy_srq(struct ib_srq *srq, struct ib_udata *udata)
{
        struct mlx5_ib_dev *dev = to_mdev(srq->device);
        struct mlx5_ib_srq *msrq = to_msrq(srq);
        int ret;

        ret = mlx5_cmd_destroy_srq(dev, &msrq->msrq);
        if (ret)
                return ret;

        if (udata)
                destroy_srq_user(srq->pd, msrq, udata);
        else
                destroy_srq_kernel(dev, msrq);
        return 0;
}

void mlx5_ib_free_srq_wqe(struct mlx5_ib_srq *srq, int wqe_index)
{
        struct mlx5_wqe_srq_next_seg *next;

        /* always called with interrupts disabled. */
        spin_lock(&srq->lock);

        next = get_wqe(srq, srq->tail);
        next->next_wqe_index = cpu_to_be16(wqe_index);
        srq->tail = wqe_index;

        spin_unlock(&srq->lock);
}

int mlx5_ib_post_srq_recv(struct ib_srq *ibsrq, const struct ib_recv_wr *wr,
                          const struct ib_recv_wr **bad_wr)
{
        struct mlx5_ib_srq *srq = to_msrq(ibsrq);
        struct mlx5_wqe_srq_next_seg *next;
        struct mlx5_wqe_data_seg *scat;
        struct mlx5_ib_dev *dev = to_mdev(ibsrq->device);
        struct mlx5_core_dev *mdev = dev->mdev;
        unsigned long flags;
        int err = 0;
        int nreq;
        int i;

        spin_lock_irqsave(&srq->lock, flags);

        if (mdev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR) {
                err = -EIO;
                *bad_wr = wr;
                goto out;
        }

        for (nreq = 0; wr; nreq++, wr = wr->next) {
                if (unlikely(wr->num_sge > srq->msrq.max_gs)) {
                        err = -EINVAL;
                        *bad_wr = wr;
                        break;
                }

                if (unlikely(srq->head == srq->tail)) {
                        err = -ENOMEM;
                        *bad_wr = wr;
                        break;
                }

                srq->wrid[srq->head] = wr->wr_id;

                next      = get_wqe(srq, srq->head);
                srq->head = be16_to_cpu(next->next_wqe_index);
                scat      = (struct mlx5_wqe_data_seg *)(next + 1);

                for (i = 0; i < wr->num_sge; i++) {
                        scat[i].byte_count = cpu_to_be32(wr->sg_list[i].length);
                        scat[i].lkey       = cpu_to_be32(wr->sg_list[i].lkey);
                        scat[i].addr       = cpu_to_be64(wr->sg_list[i].addr);
                }

                if (i < srq->msrq.max_avail_gather) {
                        scat[i].byte_count = 0;
                        scat[i].lkey = dev->mkeys.terminate_scatter_list_mkey;
                        scat[i].addr       = 0;
                }
        }

        if (likely(nreq)) {
                srq->wqe_ctr += nreq;

                /* Make sure that descriptors are written before
                 * doorbell record.
                 */
                wmb();

                *srq->db.db = cpu_to_be32(srq->wqe_ctr);
        }
out:
        spin_unlock_irqrestore(&srq->lock, flags);

        return err;
}