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

On Wed, Aug 03, 2016 at 04:27:39PM -0700, Adit Ranadive wrote:

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

--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html