+int fast_reg_xdr(struct svcxprt_rdma *xprt,
+ struct xdr_buf *xdr,
+ struct svc_rdma_req_map *vec)
+{
+ int sge_no;
+ u32 sge_bytes;
+ u32 page_bytes;
+ u32 page_off;
+ int page_no = 0;
+ u8 *frva;
+ struct svc_rdma_fastreg_mr *frmr;
+
+ frmr = svc_rdma_get_frmr(xprt);
+ if (IS_ERR(frmr))
+ return -ENOMEM;
+ vec->frmr = frmr;
+
+ /* Skip the RPCRDMA header */
+ sge_no = 1;
+
+ /* Map the head. */
+ frva = (void *)((unsigned long)(xdr->head[0].iov_base) & PAGE_MASK);
+ vec->sge[sge_no].iov_base = xdr->head[0].iov_base;
+ vec->sge[sge_no].iov_len = xdr->head[0].iov_len;
+ vec->count = 2;
+ sge_no++;
+
+ /* Build the FRMR */
+ frmr->kva = frva;
+ frmr->direction = DMA_TO_DEVICE;
+ frmr->access_flags = 0;
+ frmr->map_len = PAGE_SIZE;
+ frmr->page_list_len = 1;
+ frmr->page_list->page_list[page_no] =
+ ib_dma_map_single(xprt->sc_cm_id->device,
+ (void *)xdr->head[0].iov_base,
+ PAGE_SIZE, DMA_TO_DEVICE);
+ if (ib_dma_mapping_error(xprt->sc_cm_id->device,
+ frmr->page_list->page_list[page_no]))
+ goto fatal_err;
+ atomic_inc(&xprt->sc_dma_used);
+
+ page_off = xdr->page_base;
+ page_bytes = xdr->page_len + page_off;
+ if (!page_bytes)
+ goto encode_tail;
+
+ /* Map the pages */
+ vec->sge[sge_no].iov_base = frva + frmr->map_len + page_off;
+ vec->sge[sge_no].iov_len = page_bytes;
+ sge_no++;
+ while (page_bytes) {
+ struct page *page;
+
+ page = xdr->pages[page_no++];
+ sge_bytes = min_t(u32, page_bytes, (PAGE_SIZE - page_off));
+ page_bytes -= sge_bytes;
+
+ frmr->page_list->page_list[page_no] =
+ ib_dma_map_page(xprt->sc_cm_id->device, page, 0,
+ PAGE_SIZE, DMA_TO_DEVICE);
+ if (ib_dma_mapping_error(xprt->sc_cm_id->device,
+ frmr->page_list->page_list[page_no]))
+ goto fatal_err;
+
+ atomic_inc(&xprt->sc_dma_used);
+ page_off = 0; /* reset for next time through loop */
+ frmr->map_len += PAGE_SIZE;
+ frmr->page_list_len++;
+ }
+ vec->count++;
+
+ encode_tail:
+ /* Map tail */
+ if (0 == xdr->tail[0].iov_len)
+ goto done;
+
+ vec->count++;
+ vec->sge[sge_no].iov_len = xdr->tail[0].iov_len;
+
+ if (((unsigned long)xdr->tail[0].iov_base & PAGE_MASK) ==
+ ((unsigned long)xdr->head[0].iov_base & PAGE_MASK)) {
+ /*
+ * If head and tail use the same page, we don't need
+ * to map it again.
+ */
+ vec->sge[sge_no].iov_base = xdr->tail[0].iov_base;
+ } else {
+ void *va;
+
+ /* Map another page for the tail */
+ page_off = (unsigned long)xdr->tail[0].iov_base & ~PAGE_MASK;
+ va = (void *)((unsigned long)xdr->tail[0].iov_base & PAGE_MASK);
+ vec->sge[sge_no].iov_base = frva + frmr->map_len + page_off;
+
+ frmr->page_list->page_list[page_no] =
+ ib_dma_map_single(xprt->sc_cm_id->device, va, PAGE_SIZE,
+ DMA_TO_DEVICE);
+ if (ib_dma_mapping_error(xprt->sc_cm_id->device,
+ frmr->page_list->page_list[page_no]))
+ goto fatal_err;
+ atomic_inc(&xprt->sc_dma_used);
+ frmr->map_len += PAGE_SIZE;
+ frmr->page_list_len++;
+ }
+
+ done:
+ if (svc_rdma_fastreg(xprt, frmr))
+ goto fatal_err;
+
+ return 0;
+
+ fatal_err:
+ printk("svcrdma: Error fast registering memory for xprt %p\n", xprt);
+ svc_rdma_put_frmr(xprt, frmr);
+ return -EIO;
+}
+
+static int map_xdr(struct svcxprt_rdma *xprt,
+ struct xdr_buf *xdr,
+ struct svc_rdma_req_map *vec)