srq.c

/*
 * Copyright (c) 2013, Mellanox Technologies inc.  All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

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

#include "mlx5_ib.h"
#include "user.h"

/* not supported currently */
static int srq_signature;

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, 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_create_srq_mbox_in **in,
			   struct ib_udata *udata, int buf_size, int *inlen)
{
	struct mlx5_ib_dev *dev = to_mdev(pd->device);
	struct mlx5_ib_create_srq ucmd;
	int err;
	int npages;
	int page_shift;
	int ncont;
	u32 offset;

	if (ib_copy_from_udata(&ucmd, udata, sizeof(ucmd))) {
		mlx5_ib_dbg(dev, "failed copy udata\n");
		return -EFAULT;
	}
	srq->wq_sig = !!(ucmd.flags & MLX5_SRQ_FLAG_SIGNATURE);

	srq->umem = ib_umem_get(pd->uobject->context, 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, &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;
	}

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

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

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

	(*in)->ctx.log_pg_sz = page_shift - PAGE_SHIFT;
	(*in)->ctx.pgoff_cqn = cpu_to_be32(offset << 26);

	return 0;

err_in:
	mlx5_vfree(*in);

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_create_srq_mbox_in **in, int buf_size,
			     int *inlen)
{
	int err;
	int i;
	struct mlx5_wqe_srq_next_seg *next;
	int page_shift;
	int npages;

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

	*srq->db.db = 0;

	if (mlx5_buf_alloc(&dev->mdev, buf_size, PAGE_SIZE * 2, &srq->buf)) {
		mlx5_ib_dbg(dev, "buf alloc failed\n");
		err = -ENOMEM;
		goto err_db;
	}
	page_shift = srq->buf.page_shift;

	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));
	}

	npages = DIV_ROUND_UP(srq->buf.npages, 1 << (page_shift - PAGE_SHIFT));
	mlx5_ib_dbg(dev, "buf_size %d, page_shift %d, npages %d, calc npages %d\n",
		    buf_size, page_shift, srq->buf.npages, npages);
	*inlen = sizeof(**in) + sizeof(*(*in)->pas) * npages;
	*in = mlx5_vzalloc(*inlen);
	if (!*in) {
		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) {
		mlx5_ib_dbg(dev, "kmalloc failed %lu\n",
			    (unsigned long)(srq->msrq.max * sizeof(u64)));
		err = -ENOMEM;
		goto err_in;
	}
	srq->wq_sig = !!srq_signature;

	(*in)->ctx.log_pg_sz = page_shift - PAGE_SHIFT;

	return 0;

err_in:
	mlx5_vfree(*in);

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)
{
	mlx5_ib_db_unmap_user(to_mucontext(pd->uobject->context), &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);
}

struct ib_srq *mlx5_ib_create_srq(struct ib_pd *pd,
				  struct ib_srq_init_attr *init_attr,
				  struct ib_udata *udata)
{
	struct mlx5_ib_dev *dev = to_mdev(pd->device);
	struct mlx5_ib_srq *srq;
	int desc_size;
	int buf_size;
	int err;
	struct mlx5_create_srq_mbox_in *uninitialized_var(in);
	int uninitialized_var(inlen);
	int is_xrc;
	u32 flgs, xrcdn;

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

	srq = kmalloc(sizeof(*srq), GFP_KERNEL);
	if (!srq)
		return ERR_PTR(-ENOMEM);

	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);
	desc_size = roundup_pow_of_two(desc_size);
	desc_size = max_t(int, 32, desc_size);
	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;
	mlx5_ib_dbg(dev, "desc_size 0x%x, req wr 0x%x, srq size 0x%x, max_gs 0x%x, max_avail_gather 0x%x\n",
		    desc_size, init_attr->attr.max_wr, srq->msrq.max, srq->msrq.max_gs,
		    srq->msrq.max_avail_gather);

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

	if (err) {
		mlx5_ib_warn(dev, "create srq %s failed, err %d\n",
			     pd->uobject ? "user" : "kernel", err);
		goto err_srq;
	}

	is_xrc = (init_attr->srq_type == IB_SRQT_XRC);
	in->ctx.state_log_sz = ilog2(srq->msrq.max);
	flgs = ((srq->msrq.wqe_shift - 4) | (is_xrc << 5) | (srq->wq_sig << 7)) << 24;
	xrcdn = 0;
	if (is_xrc) {
		xrcdn = to_mxrcd(init_attr->ext.xrc.xrcd)->xrcdn;
		in->ctx.pgoff_cqn |= cpu_to_be32(to_mcq(init_attr->ext.xrc.cq)->mcq.cqn);
	} else if (init_attr->srq_type == IB_SRQT_BASIC) {
		xrcdn = to_mxrcd(dev->devr.x0)->xrcdn;
		in->ctx.pgoff_cqn |= cpu_to_be32(to_mcq(dev->devr.c0)->mcq.cqn);
	}

	in->ctx.flags_xrcd = cpu_to_be32((flgs & 0xFF000000) | (xrcdn & 0xFFFFFF));

	in->ctx.pd = cpu_to_be32(to_mpd(pd)->pdn);
	in->ctx.db_record = cpu_to_be64(srq->db.dma);
	err = mlx5_core_create_srq(&dev->mdev, &srq->msrq, in, inlen);
	mlx5_vfree(in);
	if (err) {
		mlx5_ib_dbg(dev, "create SRQ failed, err %d\n", err);
		goto err_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 (pd->uobject)
		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 &srq->ibsrq;

err_core:
	mlx5_core_destroy_srq(&dev->mdev, &srq->msrq);
	if (pd->uobject)
		destroy_srq_user(pd, srq);
	else
		destroy_srq_kernel(dev, srq);

err_srq:
	kfree(srq);

	return ERR_PTR(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_query_srq_mbox_out *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 = be16_to_cpu(out->ctx.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 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(to_mucontext(srq->uobject->context), &msrq->db);
		ib_umem_release(msrq->umem);
	} else {
		kfree(msrq->wrid);
		mlx5_buf_free(&dev->mdev, &msrq->buf);
		mlx5_db_free(&dev->mdev, &msrq->db);
	}

	kfree(srq);
	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, struct ib_recv_wr *wr,
			  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;
	unsigned long flags;
	int err = 0;
	int nreq;
	int i;

	spin_lock_irqsave(&srq->lock, flags);

	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);
	}

	spin_unlock_irqrestore(&srq->lock, flags);

	return err;
}