/* * Copyright (c) 2005-2006 Network Appliance, 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 BSD-type * 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. * * Neither the name of the Network Appliance, Inc. nor the names of * its contributors may be used to endorse or promote products * derived from this software without specific prior written * permission. * * 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 * OWNER 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. * * Author: Tom Tucker <tom@opengridcomputing.com> */ #include <linux/sunrpc/debug.h> #include <linux/sunrpc/rpc_rdma.h> #include <linux/spinlock.h> #include <asm/unaligned.h> #include <rdma/ib_verbs.h> #include <rdma/rdma_cm.h> #include <linux/sunrpc/svc_rdma.h> #define RPCDBG_FACILITY RPCDBG_SVCXPRT /* Encode an XDR as an array of IB SGE * * Assumptions: * - head[0] is physically contiguous. * - tail[0] is physically contiguous. * - pages[] is not physically or virtually contigous and consists of * PAGE_SIZE elements. * * Output: * SGE[0] reserved for RCPRDMA header * SGE[1] data from xdr->head[] * SGE[2..sge_count-2] data from xdr->pages[] * SGE[sge_count-1] data from xdr->tail. * * The max SGE we need is the length of the XDR / pagesize + one for * head + one for tail + one for RPCRDMA header. Since RPCSVC_MAXPAGES * reserves a page for both the request and the reply header, and this * array is only concerned with the reply we are assured that we have * on extra page for the RPCRMDA header. */ static void xdr_to_sge(struct svcxprt_rdma *xprt, struct xdr_buf *xdr, struct svc_rdma_req_map *vec) { int sge_max = (xdr->len+PAGE_SIZE-1) / PAGE_SIZE + 3; int sge_no; u32 sge_bytes; u32 page_bytes; u32 page_off; int page_no; BUG_ON(xdr->len != (xdr->head[0].iov_len + xdr->page_len + xdr->tail[0].iov_len)); /* Skip the first sge, this is for the RPCRDMA header */ sge_no = 1; /* Head SGE */ vec->sge[sge_no].iov_base = xdr->head[0].iov_base; vec->sge[sge_no].iov_len = xdr->head[0].iov_len; sge_no++; /* pages SGE */ page_no = 0; page_bytes = xdr->page_len; page_off = xdr->page_base; while (page_bytes) { vec->sge[sge_no].iov_base = page_address(xdr->pages[page_no]) + page_off; sge_bytes = min_t(u32, page_bytes, (PAGE_SIZE - page_off)); page_bytes -= sge_bytes; vec->sge[sge_no].iov_len = sge_bytes; sge_no++; page_no++; page_off = 0; /* reset for next time through loop */ } /* Tail SGE */ if (xdr->tail[0].iov_len) { vec->sge[sge_no].iov_base = xdr->tail[0].iov_base; vec->sge[sge_no].iov_len = xdr->tail[0].iov_len; sge_no++; } BUG_ON(sge_no > sge_max); vec->count = sge_no; } /* Assumptions: * - The specified write_len can be represented in sc_max_sge * PAGE_SIZE */ static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp, u32 rmr, u64 to, u32 xdr_off, int write_len, struct svc_rdma_req_map *vec) { struct ib_send_wr write_wr; struct ib_sge *sge; int xdr_sge_no; int sge_no; int sge_bytes; int sge_off; int bc; struct svc_rdma_op_ctxt *ctxt; BUG_ON(vec->count > RPCSVC_MAXPAGES); dprintk("svcrdma: RDMA_WRITE rmr=%x, to=%llx, xdr_off=%d, " "write_len=%d, vec->sge=%p, vec->count=%lu\n", rmr, (unsigned long long)to, xdr_off, write_len, vec->sge, vec->count); ctxt = svc_rdma_get_context(xprt); ctxt->direction = DMA_TO_DEVICE; sge = ctxt->sge; /* Find the SGE associated with xdr_off */ for (bc = xdr_off, xdr_sge_no = 1; bc && xdr_sge_no < vec->count; xdr_sge_no++) { if (vec->sge[xdr_sge_no].iov_len > bc) break; bc -= vec->sge[xdr_sge_no].iov_len; } sge_off = bc; bc = write_len; sge_no = 0; /* Copy the remaining SGE */ while (bc != 0 && xdr_sge_no < vec->count) { sge[sge_no].lkey = xprt->sc_phys_mr->lkey; sge_bytes = min((size_t)bc, (size_t)(vec->sge[xdr_sge_no].iov_len-sge_off)); sge[sge_no].length = sge_bytes; atomic_inc(&xprt->sc_dma_used); sge[sge_no].addr = ib_dma_map_single(xprt->sc_cm_id->device, (void *) vec->sge[xdr_sge_no].iov_base + sge_off, sge_bytes, DMA_TO_DEVICE); if (dma_mapping_error(xprt->sc_cm_id->device->dma_device, sge[sge_no].addr)) goto err; sge_off = 0; sge_no++; ctxt->count++; xdr_sge_no++; bc -= sge_bytes; } BUG_ON(bc != 0); BUG_ON(xdr_sge_no > vec->count); /* Prepare WRITE WR */ memset(&write_wr, 0, sizeof write_wr); ctxt->wr_op = IB_WR_RDMA_WRITE; write_wr.wr_id = (unsigned long)ctxt; write_wr.sg_list = &sge[0]; write_wr.num_sge = sge_no; write_wr.opcode = IB_WR_RDMA_WRITE; write_wr.send_flags = IB_SEND_SIGNALED; write_wr.wr.rdma.rkey = rmr; write_wr.wr.rdma.remote_addr = to; /* Post It */ atomic_inc(&rdma_stat_write); if (svc_rdma_send(xprt, &write_wr)) goto err; return 0; err: svc_rdma_put_context(ctxt, 0); /* Fatal error, close transport */ return -EIO; } static int send_write_chunks(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rdma_argp, struct rpcrdma_msg *rdma_resp, struct svc_rqst *rqstp, struct svc_rdma_req_map *vec) { u32 xfer_len = rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len; int write_len; int max_write; u32 xdr_off; int chunk_off; int chunk_no; struct rpcrdma_write_array *arg_ary; struct rpcrdma_write_array *res_ary; int ret; arg_ary = svc_rdma_get_write_array(rdma_argp); if (!arg_ary) return 0; res_ary = (struct rpcrdma_write_array *) &rdma_resp->rm_body.rm_chunks[1]; max_write = xprt->sc_max_sge * PAGE_SIZE; /* Write chunks start at the pagelist */ for (xdr_off = rqstp->rq_res.head[0].iov_len, chunk_no = 0; xfer_len && chunk_no < arg_ary->wc_nchunks; chunk_no++) { struct rpcrdma_segment *arg_ch; u64 rs_offset; arg_ch = &arg_ary->wc_array[chunk_no].wc_target; write_len = min(xfer_len, arg_ch->rs_length); /* Prepare the response chunk given the length actually * written */ rs_offset = get_unaligned(&(arg_ch->rs_offset)); svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no, arg_ch->rs_handle, rs_offset, write_len); chunk_off = 0; while (write_len) { int this_write; this_write = min(write_len, max_write); ret = send_write(xprt, rqstp, arg_ch->rs_handle, rs_offset + chunk_off, xdr_off, this_write, vec); if (ret) { dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n", ret); return -EIO; } chunk_off += this_write; xdr_off += this_write; xfer_len -= this_write; write_len -= this_write; } } /* Update the req with the number of chunks actually used */ svc_rdma_xdr_encode_write_list(rdma_resp, chunk_no); return rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len; } static int send_reply_chunks(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rdma_argp, struct rpcrdma_msg *rdma_resp, struct svc_rqst *rqstp, struct svc_rdma_req_map *vec) { u32 xfer_len = rqstp->rq_res.len; int write_len; int max_write; u32 xdr_off; int chunk_no; int chunk_off; struct rpcrdma_segment *ch; struct rpcrdma_write_array *arg_ary; struct rpcrdma_write_array *res_ary; int ret; arg_ary = svc_rdma_get_reply_array(rdma_argp); if (!arg_ary) return 0; /* XXX: need to fix when reply lists occur with read-list and or * write-list */ res_ary = (struct rpcrdma_write_array *) &rdma_resp->rm_body.rm_chunks[2]; max_write = xprt->sc_max_sge * PAGE_SIZE; /* xdr offset starts at RPC message */ for (xdr_off = 0, chunk_no = 0; xfer_len && chunk_no < arg_ary->wc_nchunks; chunk_no++) { u64 rs_offset; ch = &arg_ary->wc_array[chunk_no].wc_target; write_len = min(xfer_len, ch->rs_length); /* Prepare the reply chunk given the length actually * written */ rs_offset = get_unaligned(&(ch->rs_offset)); svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no, ch->rs_handle, rs_offset, write_len); chunk_off = 0; while (write_len) { int this_write; this_write = min(write_len, max_write); ret = send_write(xprt, rqstp, ch->rs_handle, rs_offset + chunk_off, xdr_off, this_write, vec); if (ret) { dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n", ret); return -EIO; } chunk_off += this_write; xdr_off += this_write; xfer_len -= this_write; write_len -= this_write; } } /* Update the req with the number of chunks actually used */ svc_rdma_xdr_encode_reply_array(res_ary, chunk_no); return rqstp->rq_res.len; } /* This function prepares the portion of the RPCRDMA message to be * sent in the RDMA_SEND. This function is called after data sent via * RDMA has already been transmitted. There are three cases: * - The RPCRDMA header, RPC header, and payload are all sent in a * single RDMA_SEND. This is the "inline" case. * - The RPCRDMA header and some portion of the RPC header and data * are sent via this RDMA_SEND and another portion of the data is * sent via RDMA. * - The RPCRDMA header [NOMSG] is sent in this RDMA_SEND and the RPC * header and data are all transmitted via RDMA. * In all three cases, this function prepares the RPCRDMA header in * sge[0], the 'type' parameter indicates the type to place in the * RPCRDMA header, and the 'byte_count' field indicates how much of * the XDR to include in this RDMA_SEND. */ static int send_reply(struct svcxprt_rdma *rdma, struct svc_rqst *rqstp, struct page *page, struct rpcrdma_msg *rdma_resp, struct svc_rdma_op_ctxt *ctxt, struct svc_rdma_req_map *vec, int byte_count) { struct ib_send_wr send_wr; int sge_no; int sge_bytes; int page_no; int ret; /* Post a recv buffer to handle another request. */ ret = svc_rdma_post_recv(rdma); if (ret) { printk(KERN_INFO "svcrdma: could not post a receive buffer, err=%d." "Closing transport %p.\n", ret, rdma); set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags); svc_rdma_put_context(ctxt, 0); return -ENOTCONN; } /* Prepare the context */ ctxt->pages[0] = page; ctxt->count = 1; /* Prepare the SGE for the RPCRDMA Header */ atomic_inc(&rdma->sc_dma_used); ctxt->sge[0].addr = ib_dma_map_page(rdma->sc_cm_id->device, page, 0, PAGE_SIZE, DMA_TO_DEVICE); ctxt->direction = DMA_TO_DEVICE; ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp); ctxt->sge[0].lkey = rdma->sc_phys_mr->lkey; /* Determine how many of our SGE are to be transmitted */ for (sge_no = 1; byte_count && sge_no < vec->count; sge_no++) { sge_bytes = min_t(size_t, vec->sge[sge_no].iov_len, byte_count); byte_count -= sge_bytes; atomic_inc(&rdma->sc_dma_used); ctxt->sge[sge_no].addr = ib_dma_map_single(rdma->sc_cm_id->device, vec->sge[sge_no].iov_base, sge_bytes, DMA_TO_DEVICE); ctxt->sge[sge_no].length = sge_bytes; ctxt->sge[sge_no].lkey = rdma->sc_phys_mr->lkey; } BUG_ON(byte_count != 0); /* Save all respages in the ctxt and remove them from the * respages array. They are our pages until the I/O * completes. */ for (page_no = 0; page_no < rqstp->rq_resused; page_no++) { ctxt->pages[page_no+1] = rqstp->rq_respages[page_no]; ctxt->count++; rqstp->rq_respages[page_no] = NULL; /* If there are more pages than SGE, terminate SGE list */ if (page_no+1 >= sge_no) ctxt->sge[page_no+1].length = 0; } BUG_ON(sge_no > rdma->sc_max_sge); memset(&send_wr, 0, sizeof send_wr); ctxt->wr_op = IB_WR_SEND; send_wr.wr_id = (unsigned long)ctxt; send_wr.sg_list = ctxt->sge; send_wr.num_sge = sge_no; send_wr.opcode = IB_WR_SEND; send_wr.send_flags = IB_SEND_SIGNALED; ret = svc_rdma_send(rdma, &send_wr); if (ret) svc_rdma_put_context(ctxt, 1); return ret; } void svc_rdma_prep_reply_hdr(struct svc_rqst *rqstp) { } /* * Return the start of an xdr buffer. */ static void *xdr_start(struct xdr_buf *xdr) { return xdr->head[0].iov_base - (xdr->len - xdr->page_len - xdr->tail[0].iov_len - xdr->head[0].iov_len); } int svc_rdma_sendto(struct svc_rqst *rqstp) { struct svc_xprt *xprt = rqstp->rq_xprt; struct svcxprt_rdma *rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt); struct rpcrdma_msg *rdma_argp; struct rpcrdma_msg *rdma_resp; struct rpcrdma_write_array *reply_ary; enum rpcrdma_proc reply_type; int ret; int inline_bytes; struct page *res_page; struct svc_rdma_op_ctxt *ctxt; struct svc_rdma_req_map *vec; dprintk("svcrdma: sending response for rqstp=%p\n", rqstp); /* Get the RDMA request header. */ rdma_argp = xdr_start(&rqstp->rq_arg); /* Build an req vec for the XDR */ ctxt = svc_rdma_get_context(rdma); ctxt->direction = DMA_TO_DEVICE; vec = svc_rdma_get_req_map(); xdr_to_sge(rdma, &rqstp->rq_res, vec); inline_bytes = rqstp->rq_res.len; /* Create the RDMA response header */ res_page = svc_rdma_get_page(); rdma_resp = page_address(res_page); reply_ary = svc_rdma_get_reply_array(rdma_argp); if (reply_ary) reply_type = RDMA_NOMSG; else reply_type = RDMA_MSG; svc_rdma_xdr_encode_reply_header(rdma, rdma_argp, rdma_resp, reply_type); /* Send any write-chunk data and build resp write-list */ ret = send_write_chunks(rdma, rdma_argp, rdma_resp, rqstp, vec); if (ret < 0) { printk(KERN_ERR "svcrdma: failed to send write chunks, rc=%d\n", ret); goto error; } inline_bytes -= ret; /* Send any reply-list data and update resp reply-list */ ret = send_reply_chunks(rdma, rdma_argp, rdma_resp, rqstp, vec); if (ret < 0) { printk(KERN_ERR "svcrdma: failed to send reply chunks, rc=%d\n", ret); goto error; } inline_bytes -= ret; ret = send_reply(rdma, rqstp, res_page, rdma_resp, ctxt, vec, inline_bytes); svc_rdma_put_req_map(vec); dprintk("svcrdma: send_reply returns %d\n", ret); return ret; error: svc_rdma_put_req_map(vec); svc_rdma_put_context(ctxt, 0); put_page(res_page); return ret; }