net/sunrpc/xprtrdma/frwr_ops.c

Source file repositories/reference/linux-study-clean/net/sunrpc/xprtrdma/frwr_ops.c

File Facts

System
Linux kernel
Corpus path
net/sunrpc/xprtrdma/frwr_ops.c
Extension
.c
Size
22660 bytes
Lines
811
Domain
Networking Core
Bucket
Sockets, Protocols, Packet Path, And Network Policy
Inferred role
Networking Core: implementation source
Status
source implementation candidate

Why This File Exists

Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.

Dependency Surface

Detected Declarations

Annotated Snippet

while (remaining > 0 && i < max_depth) {
			unsigned int len;

			len = min_t(unsigned int,
				    PAGE_SIZE - page_base, remaining);
			sg_set_page(&mr->mr_sg[i], *ppages,
				    len, page_base);
			cur->xc_page_offset += len;
			i++;
			ppages++;
			remaining -= len;

			if (!sg_gaps && remaining > 0 &&
			    offset_in_page(page_base + len))
				goto finish;
			page_base = 0;
		}
		if (remaining == 0)
			cur->xc_flags |= XC_PAGES_DONE;
	} else if (!(cur->xc_flags & XC_PAGES_DONE)) {
		cur->xc_flags |= XC_PAGES_DONE;
	}

	/* Tail kvec */
	if (!(cur->xc_flags & XC_TAIL_DONE) && xdrbuf->tail[0].iov_len &&
	    i < max_depth) {
		const struct kvec *tail = &xdrbuf->tail[0];

		if (!sg_gaps && i > 0) {
			struct scatterlist *prev = &mr->mr_sg[i - 1];

			if (offset_in_page(prev->offset + prev->length) ||
			    offset_in_page(tail->iov_base))
				goto finish;
		}
		sg_set_page(&mr->mr_sg[i],
			    virt_to_page(tail->iov_base),
			    tail->iov_len,
			    offset_in_page(tail->iov_base));
		cur->xc_flags |= XC_TAIL_DONE;
		i++;
	} else if (!(cur->xc_flags & XC_TAIL_DONE) &&
		   !xdrbuf->tail[0].iov_len) {
		cur->xc_flags |= XC_TAIL_DONE;
	}

finish:
	mr->mr_dir = rpcrdma_data_dir(writing);
	mr->mr_nents = i;

	dma_nents = ib_dma_map_sg(ep->re_id->device, mr->mr_sg, mr->mr_nents,
				  mr->mr_dir);
	if (!dma_nents)
		goto out_dmamap_err;
	mr->mr_device = ep->re_id->device;

	ibmr = mr->mr_ibmr;
	n = ib_map_mr_sg(ibmr, mr->mr_sg, dma_nents, NULL, PAGE_SIZE);
	if (n != dma_nents)
		goto out_mapmr_err;

	ibmr->iova &= 0x00000000ffffffff;
	ibmr->iova |= ((u64)be32_to_cpu(xid)) << 32;
	key = (u8)(ibmr->rkey & 0x000000FF);
	ib_update_fast_reg_key(ibmr, ++key);

	reg_wr = &mr->mr_regwr;
	reg_wr->mr = ibmr;
	reg_wr->key = ibmr->rkey;
	reg_wr->access = writing ?
			 IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
			 IB_ACCESS_REMOTE_READ;

	mr->mr_handle = ibmr->rkey;
	mr->mr_length = ibmr->length;
	mr->mr_offset = ibmr->iova;
	trace_xprtrdma_mr_map(mr);

	return 0;

out_dmamap_err:
	trace_xprtrdma_frwr_sgerr(mr, i);
	return -EIO;

out_mapmr_err:
	trace_xprtrdma_frwr_maperr(mr, n);
	return -EIO;
}

/**

Annotation

Implementation Notes