Re: [PATCH v3 10/15] IB/pvrdma: Add support for memory regions

[Yuval Shaia <yuval.shaia-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>]

On Wed, Aug 03, 2016 at 04:27:39PM -0700, Adit Ranadive wrote:
> This patch adds support for creating and destroying memory regions. The
> PVRDMA device supports User MRs, DMA MRs (no Remote Read/Write support),
> Fast Register MRs.
> 
> Changes v2->v3:
>  - Removed boolean in pvrdma_cmd_post.
> 
> Reviewed-by: Jorgen Hansen <jhansen-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
> Reviewed-by: George Zhang <georgezhang-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
> Reviewed-by: Aditya Sarwade <asarwade-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
> Reviewed-by: Bryan Tan <bryantan-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Adit Ranadive <aditr-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
> ---
>  drivers/infiniband/hw/pvrdma/pvrdma_mr.c | 331 +++++++++++++++++++++++++++++++
>  1 file changed, 331 insertions(+)
>  create mode 100644 drivers/infiniband/hw/pvrdma/pvrdma_mr.c
> 
> diff --git a/drivers/infiniband/hw/pvrdma/pvrdma_mr.c b/drivers/infiniband/hw/pvrdma/pvrdma_mr.c
> new file mode 100644
> index 0000000..261b8d4
> --- /dev/null
> +++ b/drivers/infiniband/hw/pvrdma/pvrdma_mr.c
> @@ -0,0 +1,331 @@
> +/*
> + * Copyright (c) 2012-2016 VMware, Inc.  All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of EITHER the GNU General Public License
> + * version 2 as published by the Free Software Foundation or the BSD
> + * 2-Clause License. This program is distributed in the hope that it
> + * will be useful, but WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED
> + * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
> + * See the GNU General Public License version 2 for more details at
> + * http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program available in the file COPYING in the main
> + * directory of this source tree.
> + *
> + * The BSD 2-Clause License
> + *
> + *     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.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 THE
> + * COPYRIGHT HOLDER 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 <linux/list.h>
> +#include <linux/slab.h>
> +
> +#include "pvrdma.h"
> +
> +/**
> + * pvrdma_get_dma_mr - get a DMA memory region
> + * @pd: protection domain
> + * @acc: access flags
> + *
> + * @return: ib_mr pointer on success, otherwise returns an errno.
> + */
> +struct ib_mr *pvrdma_get_dma_mr(struct ib_pd *pd, int acc)
> +{
> +	struct pvrdma_dev *dev = to_vdev(pd->device);
> +	struct pvrdma_user_mr *mr;
> +	union pvrdma_cmd_req req;
> +	union pvrdma_cmd_resp rsp;
> +	struct pvrdma_cmd_create_mr *cmd = &req.create_mr;
> +	struct pvrdma_cmd_create_mr_resp *resp = &rsp.create_mr_resp;
> +	int ret;
> +
> +	if (acc != IB_ACCESS_LOCAL_WRITE) {

Since those access flags are bits i suggest to use bit operations.
	if (!(acc & IB_ACCESS_LOCAL_WRITE))

> +		dev_warn(&dev->pdev->dev, "unsupported dma mr access flags\n");
> +		return ERR_PTR(-EOPNOTSUPP);
> +	}
> +
> +	mr = kzalloc(sizeof(*mr), GFP_KERNEL);
> +	if (!mr)
> +		return ERR_PTR(-ENOMEM);

Suggesting to do this allocation after command succeeds. This way you will
not have to deal with free-ing it when cmd fails.

> +
> +	memset(cmd, 0, sizeof(*cmd));
> +	cmd->hdr.cmd = PVRDMA_CMD_CREATE_MR;
> +	cmd->pd_handle = to_vpd(pd)->pd_handle;
> +	cmd->access_flags = acc;
> +	cmd->flags = PVRDMA_MR_FLAG_DMA;
> +
> +	ret = pvrdma_cmd_post(dev, &req, &rsp);
> +	if (ret < 0) {
> +		dev_warn(&dev->pdev->dev, "could not get DMA mem region\n");
> +		kfree(mr);
> +		return ERR_PTR(ret);
> +	}
> +
> +	mr->mmr.mr_handle = resp->mr_handle;
> +	mr->ibmr.lkey = resp->lkey;
> +	mr->ibmr.rkey = resp->rkey;
> +
> +	return &mr->ibmr;
> +}
> +
> +/**
> + * pvrdma_reg_user_mr - register a userspace memory region
> + * @pd: protection domain
> + * @start: starting address
> + * @length: length of region
> + * @virt_addr: I/O virtual address
> + * @access_flags: access flags for memory region
> + * @udata: user data
> + *
> + * @return: ib_mr pointer on success, otherwise returns an errno.
> + */
> +struct ib_mr *pvrdma_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
> +				 u64 virt_addr, int access_flags,
> +				 struct ib_udata *udata)
> +{
> +	struct pvrdma_dev *dev = to_vdev(pd->device);
> +	struct pvrdma_user_mr *mr = NULL;
> +	struct ib_umem *umem;
> +	union pvrdma_cmd_req req;
> +	union pvrdma_cmd_resp rsp;
> +	struct pvrdma_cmd_create_mr *cmd = &req.create_mr;
> +	struct pvrdma_cmd_create_mr_resp *resp = &rsp.create_mr_resp;
> +	int nchunks;
> +	int ret;
> +	int entry;
> +	struct scatterlist *sg;
> +
> +	if (length == 0 || length > dev->dsr->caps.max_mr_size) {
> +		dev_warn(&dev->pdev->dev, "invalid mem region length\n");
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	umem = ib_umem_get(pd->uobject->context, start,
> +			   length, access_flags, 0);
> +	if (IS_ERR(umem)) {
> +		dev_warn(&dev->pdev->dev,
> +			 "could not get umem for mem region\n");
> +		return ERR_CAST(umem);
> +	}
> +
> +	nchunks = 0;
> +	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry)
> +		nchunks += sg_dma_len(sg) >> PAGE_SHIFT;
> +
> +	if (nchunks < 0 || nchunks > PVRDMA_PAGE_DIR_MAX_PAGES) {
> +		dev_warn(&dev->pdev->dev, "overflow %d pages in mem region\n",
> +			 nchunks);
> +		ret = -EINVAL;
> +		goto err_umem;
> +	}
> +
> +	mr = kzalloc(sizeof(*mr), GFP_KERNEL);
> +	if (!mr) {
> +		ret = -ENOMEM;
> +		goto err_umem;
> +	}
> +
> +	mr->mmr.iova = virt_addr;
> +	mr->mmr.size = length;
> +	mr->umem = umem;
> +
> +	ret = pvrdma_page_dir_init(dev, &mr->pdir, nchunks, false);
> +	if (ret) {
> +		dev_warn(&dev->pdev->dev,
> +			 "could not allocate page directory\n");
> +		goto err_umem;
> +	}
> +
> +	ret = pvrdma_page_dir_insert_umem(&mr->pdir, mr->umem, 0);
> +	if (ret)
> +		goto err_pdir;
> +
> +	/* Send to host */

s/host/device

> +	memset(cmd, 0, sizeof(*cmd));
> +	cmd->hdr.cmd = PVRDMA_CMD_CREATE_MR;
> +	cmd->start = start;
> +	cmd->length = length;
> +	cmd->pd_handle = to_vpd(pd)->pd_handle;
> +	cmd->access_flags = access_flags;
> +	cmd->nchunks = nchunks;
> +	cmd->pdir_dma = mr->pdir.dir_dma;
> +
> +	ret = pvrdma_cmd_post(dev, &req, &rsp);
> +
> +	if (ret < 0 || rsp.hdr.ack != PVRDMA_CMD_CREATE_MR_RESP) {
> +		dev_warn(&dev->pdev->dev, "could not register mem region\n");
> +		goto err_pdir;
> +	}
> +
> +	mr->mmr.mr_handle = resp->mr_handle;
> +	mr->ibmr.lkey = resp->lkey;
> +	mr->ibmr.rkey = resp->rkey;
> +
> +	return &mr->ibmr;
> +
> +err_pdir:
> +	pvrdma_page_dir_cleanup(dev, &mr->pdir);
> +err_umem:
> +	ib_umem_release(umem);
> +	kfree(mr);
> +
> +	return ERR_PTR(ret);
> +}
> +
> +/**
> + * pvrdma_alloc_mr - allocate a memory region
> + * @pd: protection domain
> + * @mr_type: type of memory region
> + * @max_num_sg: maximum number of pages
> + *
> + * @return: ib_mr pointer on success, otherwise returns an errno.
> + */
> +struct ib_mr *pvrdma_alloc_mr(struct ib_pd *pd, enum ib_mr_type mr_type,
> +			      u32 max_num_sg)
> +{
> +	struct pvrdma_dev *dev = to_vdev(pd->device);
> +	struct pvrdma_user_mr *mr;
> +	union pvrdma_cmd_req req;
> +	union pvrdma_cmd_resp rsp;
> +	struct pvrdma_cmd_create_mr *cmd = &req.create_mr;
> +	struct pvrdma_cmd_create_mr_resp *resp = &rsp.create_mr_resp;
> +	int size = max_num_sg * sizeof(u64);
> +	int ret;
> +
> +	if (mr_type != IB_MR_TYPE_MEM_REG ||
> +	    max_num_sg > PVRDMA_MAX_FAST_REG_PAGES)
> +		return ERR_PTR(-EINVAL);
> +
> +	mr = kzalloc(sizeof(*mr), GFP_KERNEL);
> +	if (!mr)
> +		return ERR_PTR(-ENOMEM);
> +
> +	mr->pages = kzalloc(size, GFP_KERNEL);
> +	if (!mr->pages) {
> +		ret = -ENOMEM;
> +		goto freemr;
> +	}
> +
> +	ret = pvrdma_page_dir_init(dev, &mr->pdir, max_num_sg, false);
> +	if (ret) {
> +		dev_warn(&dev->pdev->dev,
> +			 "failed to allocate page dir for mr\n");
> +		ret = -ENOMEM;
> +		goto freepages;
> +	}
> +
> +	memset(cmd, 0, sizeof(*cmd));
> +	cmd->hdr.cmd = PVRDMA_CMD_CREATE_MR;
> +	cmd->pd_handle = to_vpd(pd)->pd_handle;
> +	cmd->access_flags = 0;
> +	cmd->flags = PVRDMA_MR_FLAG_FRMR;
> +	cmd->nchunks = max_num_sg;
> +
> +	ret = pvrdma_cmd_post(dev, &req, &rsp);
> +	if (ret < 0) {
> +		dev_warn(&dev->pdev->dev, "could not create FR mem region\n");
> +		ret = -EINVAL;
> +		goto freepdir;
> +	}
> +
> +	mr->max_pages = max_num_sg;
> +	mr->mmr.mr_handle = resp->mr_handle;
> +	mr->ibmr.lkey = resp->lkey;
> +	mr->ibmr.rkey = resp->rkey;
> +	mr->page_shift = PAGE_SHIFT;
> +	mr->umem = NULL;
> +
> +	return &mr->ibmr;
> +
> +freepdir:
> +	pvrdma_page_dir_cleanup(dev, &mr->pdir);
> +freepages:
> +	kfree(mr->pages);
> +freemr:
> +	kfree(mr);
> +	return ERR_PTR(ret);
> +}
> +
> +/**
> + * pvrdma_dereg_mr - deregister a memory region
> + * @ibmr: memory region
> + *
> + * @return: 0 on success.
> + */
> +int pvrdma_dereg_mr(struct ib_mr *ibmr)
> +{
> +	struct pvrdma_user_mr *mr = to_vmr(ibmr);
> +	struct pvrdma_dev *dev = to_vdev(ibmr->device);
> +	union pvrdma_cmd_req req;
> +	struct pvrdma_cmd_destroy_mr *cmd = &req.destroy_mr;
> +	int ret;
> +
> +	memset(cmd, 0, sizeof(*cmd));
> +	cmd->hdr.cmd = PVRDMA_CMD_DESTROY_MR;
> +	cmd->mr_handle = mr->mmr.mr_handle;
> +	ret = pvrdma_cmd_post(dev, &req, NULL);
> +	if (ret < 0)
> +		dev_warn(&dev->pdev->dev, "could not deregister mem region\n");
> +
> +	pvrdma_page_dir_cleanup(dev, &mr->pdir);
> +	if (mr->umem)
> +		ib_umem_release(mr->umem);
> +
> +	kfree(mr->pages);
> +	kfree(mr);
> +
> +	return 0;
> +}
> +
> +static int pvrdma_set_page(struct ib_mr *ibmr, u64 addr)
> +{
> +	struct pvrdma_user_mr *mr = to_vmr(ibmr);
> +
> +	if (mr->npages == mr->max_pages)
> +		return -ENOMEM;
> +
> +	mr->pages[mr->npages++] = addr;
> +	return 0;
> +}
> +
> +int pvrdma_map_mr_sg(struct ib_mr *ibmr, struct scatterlist *sg, int sg_nents,
> +		     unsigned int *sg_offset)
> +{
> +	struct pvrdma_user_mr *mr = to_vmr(ibmr);
> +	struct pvrdma_dev *dev = to_vdev(ibmr->device);
> +	int ret;
> +
> +	mr->npages = 0;
> +
> +	ret = ib_sg_to_pages(ibmr, sg, sg_nents, sg_offset, pvrdma_set_page);
> +	if (ret < 0)
> +		dev_warn(&dev->pdev->dev, "could not map sg to pages\n");
> +
> +	return ret;
> +}
> -- 
> 2.7.4
> 
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