/*-
 * Copyright (c) 2013-2020, Mellanox Technologies, Ltd.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY AUTHOR 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 AUTHOR 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 "opt_rss.h"
#include "opt_ratelimit.h"

#include <linux/module.h>
#include <dev/mlx5/qp.h>
#include <dev/mlx5/srq.h>
#include <linux/slab.h>
#include <rdma/ib_umem.h>
#include <rdma/ib_user_verbs.h>
#include <rdma/uverbs_ioctl.h>

#include <dev/mlx5/mlx5_ib/mlx5_ib.h>

static void *get_wqe(struct mlx5_ib_srq *srq, int n)
{
	return mlx5_buf_offset(&srq->buf, n << srq->msrq.wqe_shift);
}

static void mlx5_ib_srq_event(struct mlx5_core_srq *srq, int 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;
	int npages;
	int page_shift;
	int ncont;
	u32 offset;
	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(&ucontext->ibucontext, ucmd.buf_addr, buf_size, 0, 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;
	}

	mlx5_ib_cont_pages(srq->umem, ucmd.buf_addr, 0, &npages,
			   &page_shift, &ncont, NULL);
	err = mlx5_ib_get_buf_offset(ucmd.buf_addr, page_shift,
				     &offset);
	if (err) {
		mlx5_ib_warn(dev, "bad offset\n");
		goto err_umem;
	}

	in->pas = mlx5_vzalloc(sizeof(*in->pas) * ncont);
	if (!in->pas) {
		err = -ENOMEM;
		goto err_umem;
	}

	mlx5_ib_populate_pas(dev, srq->umem, page_shift, in->pas, 0);

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

	in->log_page_size = page_shift - MLX5_ADAPTER_PAGE_SHIFT;
	in->page_offset = offset;
	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_in:
	kvfree(in->pas);

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_buf_alloc(dev->mdev, buf_size, 2 * PAGE_SIZE, &srq->buf)) {
		mlx5_ib_dbg(dev, "buf alloc failed\n");
		err = -ENOMEM;
		goto err_db;
	}

	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 = mlx5_vzalloc(sizeof(*in->pas) * srq->buf.npages);
	if (!in->pas) {
		err = -ENOMEM;
		goto err_buf;
	}
	mlx5_fill_page_array(&srq->buf, in->pas);

	srq->wrid = kmalloc(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_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)
{
	kfree(srq->wrid);
	mlx5_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);

	/* Sanity check SRQ size before proceeding */
	if (init_attr->attr.max_wr >= max_srq_wqes) {
		mlx5_ib_dbg(dev, "max_wr %d, cap %d\n",
			    init_attr->attr.max_wr,
			    max_srq_wqes);
		return -EINVAL;
	}

	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)
		in.xrcd = to_mxrcd(init_attr->ext.xrc.xrcd)->xrcdn;
	else
		in.xrcd = to_mxrcd(dev->devr.x0)->xrcdn;

	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_core_create_srq(dev->mdev, &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)
		if (ib_copy_to_udata(udata, &srq->msrq.srqn, sizeof(__u32))) {
			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_core_destroy_srq(dev->mdev, &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_core_arm_srq(dev->mdev, &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(sizeof(*out), GFP_KERNEL);
	if (!out)
		return -ENOMEM;

	ret = mlx5_core_query_srq(dev->mdev, &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;
}

void 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);

	mlx5_core_destroy_srq(dev->mdev, &msrq->msrq);

	if (srq->uobject) {
		mlx5_ib_db_unmap_user(
			rdma_udata_to_drv_context(
				udata,
				struct mlx5_ib_ucontext,
				ibucontext),
			&msrq->db);
		ib_umem_release(msrq->umem);
	} else {
		destroy_srq_kernel(dev, msrq);
	}
}

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       = cpu_to_be32(MLX5_INVALID_LKEY);
			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;
}