1bcf3ffd4SChuck Lever // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause 2c06b540aSTom Tucker /* 3ecf85b23SChuck Lever * Copyright (c) 2016-2018 Oracle. All rights reserved. 40bf48289SSteve Wise * Copyright (c) 2014 Open Grid Computing, Inc. All rights reserved. 5c06b540aSTom Tucker * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved. 6c06b540aSTom Tucker * 7c06b540aSTom Tucker * This software is available to you under a choice of one of two 8c06b540aSTom Tucker * licenses. You may choose to be licensed under the terms of the GNU 9c06b540aSTom Tucker * General Public License (GPL) Version 2, available from the file 10c06b540aSTom Tucker * COPYING in the main directory of this source tree, or the BSD-type 11c06b540aSTom Tucker * license below: 12c06b540aSTom Tucker * 13c06b540aSTom Tucker * Redistribution and use in source and binary forms, with or without 14c06b540aSTom Tucker * modification, are permitted provided that the following conditions 15c06b540aSTom Tucker * are met: 16c06b540aSTom Tucker * 17c06b540aSTom Tucker * Redistributions of source code must retain the above copyright 18c06b540aSTom Tucker * notice, this list of conditions and the following disclaimer. 19c06b540aSTom Tucker * 20c06b540aSTom Tucker * Redistributions in binary form must reproduce the above 21c06b540aSTom Tucker * copyright notice, this list of conditions and the following 22c06b540aSTom Tucker * disclaimer in the documentation and/or other materials provided 23c06b540aSTom Tucker * with the distribution. 24c06b540aSTom Tucker * 25c06b540aSTom Tucker * Neither the name of the Network Appliance, Inc. nor the names of 26c06b540aSTom Tucker * its contributors may be used to endorse or promote products 27c06b540aSTom Tucker * derived from this software without specific prior written 28c06b540aSTom Tucker * permission. 29c06b540aSTom Tucker * 30c06b540aSTom Tucker * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 31c06b540aSTom Tucker * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 32c06b540aSTom Tucker * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 33c06b540aSTom Tucker * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 34c06b540aSTom Tucker * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 35c06b540aSTom Tucker * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 36c06b540aSTom Tucker * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 37c06b540aSTom Tucker * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 38c06b540aSTom Tucker * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 39c06b540aSTom Tucker * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 40c06b540aSTom Tucker * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 41c06b540aSTom Tucker * 42c06b540aSTom Tucker * Author: Tom Tucker <tom@opengridcomputing.com> 43c06b540aSTom Tucker */ 44c06b540aSTom Tucker 459a6a180bSChuck Lever /* Operation 469a6a180bSChuck Lever * 479a6a180bSChuck Lever * The main entry point is svc_rdma_sendto. This is called by the 489a6a180bSChuck Lever * RPC server when an RPC Reply is ready to be transmitted to a client. 499a6a180bSChuck Lever * 509a6a180bSChuck Lever * The passed-in svc_rqst contains a struct xdr_buf which holds an 519a6a180bSChuck Lever * XDR-encoded RPC Reply message. sendto must construct the RPC-over-RDMA 529a6a180bSChuck Lever * transport header, post all Write WRs needed for this Reply, then post 539a6a180bSChuck Lever * a Send WR conveying the transport header and the RPC message itself to 549a6a180bSChuck Lever * the client. 559a6a180bSChuck Lever * 569a6a180bSChuck Lever * svc_rdma_sendto must fully transmit the Reply before returning, as 579a6a180bSChuck Lever * the svc_rqst will be recycled as soon as sendto returns. Remaining 589a6a180bSChuck Lever * resources referred to by the svc_rqst are also recycled at that time. 599a6a180bSChuck Lever * Therefore any resources that must remain longer must be detached 609a6a180bSChuck Lever * from the svc_rqst and released later. 619a6a180bSChuck Lever * 629a6a180bSChuck Lever * Page Management 639a6a180bSChuck Lever * 649a6a180bSChuck Lever * The I/O that performs Reply transmission is asynchronous, and may 659a6a180bSChuck Lever * complete well after sendto returns. Thus pages under I/O must be 669a6a180bSChuck Lever * removed from the svc_rqst before sendto returns. 679a6a180bSChuck Lever * 689a6a180bSChuck Lever * The logic here depends on Send Queue and completion ordering. Since 699a6a180bSChuck Lever * the Send WR is always posted last, it will always complete last. Thus 709a6a180bSChuck Lever * when it completes, it is guaranteed that all previous Write WRs have 719a6a180bSChuck Lever * also completed. 729a6a180bSChuck Lever * 739a6a180bSChuck Lever * Write WRs are constructed and posted. Each Write segment gets its own 749a6a180bSChuck Lever * svc_rdma_rw_ctxt, allowing the Write completion handler to find and 759a6a180bSChuck Lever * DMA-unmap the pages under I/O for that Write segment. The Write 769a6a180bSChuck Lever * completion handler does not release any pages. 779a6a180bSChuck Lever * 784201c746SChuck Lever * When the Send WR is constructed, it also gets its own svc_rdma_send_ctxt. 799a6a180bSChuck Lever * The ownership of all of the Reply's pages are transferred into that 809a6a180bSChuck Lever * ctxt, the Send WR is posted, and sendto returns. 819a6a180bSChuck Lever * 824201c746SChuck Lever * The svc_rdma_send_ctxt is presented when the Send WR completes. The 839a6a180bSChuck Lever * Send completion handler finally releases the Reply's pages. 849a6a180bSChuck Lever * 859a6a180bSChuck Lever * This mechanism also assumes that completions on the transport's Send 869a6a180bSChuck Lever * Completion Queue do not run in parallel. Otherwise a Write completion 879a6a180bSChuck Lever * and Send completion running at the same time could release pages that 889a6a180bSChuck Lever * are still DMA-mapped. 899a6a180bSChuck Lever * 909a6a180bSChuck Lever * Error Handling 919a6a180bSChuck Lever * 929a6a180bSChuck Lever * - If the Send WR is posted successfully, it will either complete 939a6a180bSChuck Lever * successfully, or get flushed. Either way, the Send completion 949a6a180bSChuck Lever * handler releases the Reply's pages. 959a6a180bSChuck Lever * - If the Send WR cannot be not posted, the forward path releases 969a6a180bSChuck Lever * the Reply's pages. 979a6a180bSChuck Lever * 989a6a180bSChuck Lever * This handles the case, without the use of page reference counting, 999a6a180bSChuck Lever * where two different Write segments send portions of the same page. 1009a6a180bSChuck Lever */ 1019a6a180bSChuck Lever 102c06b540aSTom Tucker #include <linux/spinlock.h> 103c06b540aSTom Tucker #include <asm/unaligned.h> 10498895edbSChuck Lever 105c06b540aSTom Tucker #include <rdma/ib_verbs.h> 106c06b540aSTom Tucker #include <rdma/rdma_cm.h> 10798895edbSChuck Lever 10898895edbSChuck Lever #include <linux/sunrpc/debug.h> 109c06b540aSTom Tucker #include <linux/sunrpc/svc_rdma.h> 110c06b540aSTom Tucker 11198895edbSChuck Lever #include "xprt_rdma.h" 11298895edbSChuck Lever #include <trace/events/rpcrdma.h> 11398895edbSChuck Lever 1144201c746SChuck Lever static void svc_rdma_wc_send(struct ib_cq *cq, struct ib_wc *wc); 1154201c746SChuck Lever 1163ac56c2fSChuck Lever static void svc_rdma_send_cid_init(struct svcxprt_rdma *rdma, 1173ac56c2fSChuck Lever struct rpc_rdma_cid *cid) 1183ac56c2fSChuck Lever { 1193ac56c2fSChuck Lever cid->ci_queue_id = rdma->sc_sq_cq->res.id; 1203ac56c2fSChuck Lever cid->ci_completion_id = atomic_inc_return(&rdma->sc_completion_ids); 1213ac56c2fSChuck Lever } 1223ac56c2fSChuck Lever 1234201c746SChuck Lever static struct svc_rdma_send_ctxt * 1244201c746SChuck Lever svc_rdma_send_ctxt_alloc(struct svcxprt_rdma *rdma) 1254201c746SChuck Lever { 126ed51b426SChuck Lever int node = ibdev_to_node(rdma->sc_cm_id->device); 1274201c746SChuck Lever struct svc_rdma_send_ctxt *ctxt; 12899722fe4SChuck Lever dma_addr_t addr; 12999722fe4SChuck Lever void *buffer; 1304201c746SChuck Lever int i; 1314201c746SChuck Lever 132ed51b426SChuck Lever ctxt = kmalloc_node(struct_size(ctxt, sc_sges, rdma->sc_max_send_sges), 133ed51b426SChuck Lever GFP_KERNEL, node); 1344201c746SChuck Lever if (!ctxt) 13599722fe4SChuck Lever goto fail0; 136ed51b426SChuck Lever buffer = kmalloc_node(rdma->sc_max_req_size, GFP_KERNEL, node); 13799722fe4SChuck Lever if (!buffer) 13899722fe4SChuck Lever goto fail1; 13999722fe4SChuck Lever addr = ib_dma_map_single(rdma->sc_pd->device, buffer, 14099722fe4SChuck Lever rdma->sc_max_req_size, DMA_TO_DEVICE); 14199722fe4SChuck Lever if (ib_dma_mapping_error(rdma->sc_pd->device, addr)) 14299722fe4SChuck Lever goto fail2; 1434201c746SChuck Lever 1443ac56c2fSChuck Lever svc_rdma_send_cid_init(rdma, &ctxt->sc_cid); 1453ac56c2fSChuck Lever 1464201c746SChuck Lever ctxt->sc_send_wr.next = NULL; 1474201c746SChuck Lever ctxt->sc_send_wr.wr_cqe = &ctxt->sc_cqe; 1484201c746SChuck Lever ctxt->sc_send_wr.sg_list = ctxt->sc_sges; 1494201c746SChuck Lever ctxt->sc_send_wr.send_flags = IB_SEND_SIGNALED; 15099722fe4SChuck Lever ctxt->sc_cqe.done = svc_rdma_wc_send; 15199722fe4SChuck Lever ctxt->sc_xprt_buf = buffer; 1526fd5034dSChuck Lever xdr_buf_init(&ctxt->sc_hdrbuf, ctxt->sc_xprt_buf, 1536fd5034dSChuck Lever rdma->sc_max_req_size); 15499722fe4SChuck Lever ctxt->sc_sges[0].addr = addr; 15599722fe4SChuck Lever 15625fd86ecSChuck Lever for (i = 0; i < rdma->sc_max_send_sges; i++) 1574201c746SChuck Lever ctxt->sc_sges[i].lkey = rdma->sc_pd->local_dma_lkey; 1584201c746SChuck Lever return ctxt; 15999722fe4SChuck Lever 16099722fe4SChuck Lever fail2: 16199722fe4SChuck Lever kfree(buffer); 16299722fe4SChuck Lever fail1: 16399722fe4SChuck Lever kfree(ctxt); 16499722fe4SChuck Lever fail0: 16599722fe4SChuck Lever return NULL; 1664201c746SChuck Lever } 1674201c746SChuck Lever 1684201c746SChuck Lever /** 1694201c746SChuck Lever * svc_rdma_send_ctxts_destroy - Release all send_ctxt's for an xprt 1704201c746SChuck Lever * @rdma: svcxprt_rdma being torn down 1714201c746SChuck Lever * 1724201c746SChuck Lever */ 1734201c746SChuck Lever void svc_rdma_send_ctxts_destroy(struct svcxprt_rdma *rdma) 1744201c746SChuck Lever { 1754201c746SChuck Lever struct svc_rdma_send_ctxt *ctxt; 176b6c2bfeaSChuck Lever struct llist_node *node; 1774201c746SChuck Lever 178b6c2bfeaSChuck Lever while ((node = llist_del_first(&rdma->sc_send_ctxts)) != NULL) { 179b6c2bfeaSChuck Lever ctxt = llist_entry(node, struct svc_rdma_send_ctxt, sc_node); 18099722fe4SChuck Lever ib_dma_unmap_single(rdma->sc_pd->device, 18199722fe4SChuck Lever ctxt->sc_sges[0].addr, 18299722fe4SChuck Lever rdma->sc_max_req_size, 18399722fe4SChuck Lever DMA_TO_DEVICE); 18499722fe4SChuck Lever kfree(ctxt->sc_xprt_buf); 1854201c746SChuck Lever kfree(ctxt); 1864201c746SChuck Lever } 1874201c746SChuck Lever } 1884201c746SChuck Lever 1894201c746SChuck Lever /** 1904201c746SChuck Lever * svc_rdma_send_ctxt_get - Get a free send_ctxt 1914201c746SChuck Lever * @rdma: controlling svcxprt_rdma 1924201c746SChuck Lever * 1934201c746SChuck Lever * Returns a ready-to-use send_ctxt, or NULL if none are 1944201c746SChuck Lever * available and a fresh one cannot be allocated. 1954201c746SChuck Lever */ 1964201c746SChuck Lever struct svc_rdma_send_ctxt *svc_rdma_send_ctxt_get(struct svcxprt_rdma *rdma) 1974201c746SChuck Lever { 1984201c746SChuck Lever struct svc_rdma_send_ctxt *ctxt; 199b6c2bfeaSChuck Lever struct llist_node *node; 2004201c746SChuck Lever 2014201c746SChuck Lever spin_lock(&rdma->sc_send_lock); 202b6c2bfeaSChuck Lever node = llist_del_first(&rdma->sc_send_ctxts); 203b6c2bfeaSChuck Lever if (!node) 2044201c746SChuck Lever goto out_empty; 205b6c2bfeaSChuck Lever ctxt = llist_entry(node, struct svc_rdma_send_ctxt, sc_node); 2064201c746SChuck Lever spin_unlock(&rdma->sc_send_lock); 2074201c746SChuck Lever 2084201c746SChuck Lever out: 2096fd5034dSChuck Lever rpcrdma_set_xdrlen(&ctxt->sc_hdrbuf, 0); 2106fd5034dSChuck Lever xdr_init_encode(&ctxt->sc_stream, &ctxt->sc_hdrbuf, 2116fd5034dSChuck Lever ctxt->sc_xprt_buf, NULL); 2126fd5034dSChuck Lever 2134201c746SChuck Lever ctxt->sc_send_wr.num_sge = 0; 21499722fe4SChuck Lever ctxt->sc_cur_sge_no = 0; 215a944209cSChuck Lever ctxt->sc_page_count = 0; 2164201c746SChuck Lever return ctxt; 2174201c746SChuck Lever 2184201c746SChuck Lever out_empty: 2194201c746SChuck Lever spin_unlock(&rdma->sc_send_lock); 2204201c746SChuck Lever ctxt = svc_rdma_send_ctxt_alloc(rdma); 2214201c746SChuck Lever if (!ctxt) 2224201c746SChuck Lever return NULL; 2234201c746SChuck Lever goto out; 2244201c746SChuck Lever } 2254201c746SChuck Lever 2264201c746SChuck Lever /** 2274201c746SChuck Lever * svc_rdma_send_ctxt_put - Return send_ctxt to free list 2284201c746SChuck Lever * @rdma: controlling svcxprt_rdma 2294201c746SChuck Lever * @ctxt: object to return to the free list 230a944209cSChuck Lever * 231a944209cSChuck Lever * Pages left in sc_pages are DMA unmapped and released. 2324201c746SChuck Lever */ 2334201c746SChuck Lever void svc_rdma_send_ctxt_put(struct svcxprt_rdma *rdma, 2344201c746SChuck Lever struct svc_rdma_send_ctxt *ctxt) 2354201c746SChuck Lever { 2364201c746SChuck Lever struct ib_device *device = rdma->sc_cm_id->device; 2374201c746SChuck Lever unsigned int i; 2384201c746SChuck Lever 239*5581cf8eSChuck Lever if (ctxt->sc_page_count) 240*5581cf8eSChuck Lever release_pages(ctxt->sc_pages, ctxt->sc_page_count); 241a944209cSChuck Lever 24299722fe4SChuck Lever /* The first SGE contains the transport header, which 24399722fe4SChuck Lever * remains mapped until @ctxt is destroyed. 24499722fe4SChuck Lever */ 245832b2cb9SChuck Lever for (i = 1; i < ctxt->sc_send_wr.num_sge; i++) { 2464201c746SChuck Lever ib_dma_unmap_page(device, 2474201c746SChuck Lever ctxt->sc_sges[i].addr, 2484201c746SChuck Lever ctxt->sc_sges[i].length, 2494201c746SChuck Lever DMA_TO_DEVICE); 250832b2cb9SChuck Lever trace_svcrdma_dma_unmap_page(rdma, 251832b2cb9SChuck Lever ctxt->sc_sges[i].addr, 252832b2cb9SChuck Lever ctxt->sc_sges[i].length); 253832b2cb9SChuck Lever } 2544201c746SChuck Lever 255b6c2bfeaSChuck Lever llist_add(&ctxt->sc_node, &rdma->sc_send_ctxts); 2564201c746SChuck Lever } 2574201c746SChuck Lever 2584201c746SChuck Lever /** 2596c8c84f5SChuck Lever * svc_rdma_wake_send_waiters - manage Send Queue accounting 2606c8c84f5SChuck Lever * @rdma: controlling transport 2616c8c84f5SChuck Lever * @avail: Number of additional SQEs that are now available 2626c8c84f5SChuck Lever * 2636c8c84f5SChuck Lever */ 2646c8c84f5SChuck Lever void svc_rdma_wake_send_waiters(struct svcxprt_rdma *rdma, int avail) 2656c8c84f5SChuck Lever { 2666c8c84f5SChuck Lever atomic_add(avail, &rdma->sc_sq_avail); 2676c8c84f5SChuck Lever smp_mb__after_atomic(); 2686c8c84f5SChuck Lever if (unlikely(waitqueue_active(&rdma->sc_send_wait))) 2696c8c84f5SChuck Lever wake_up(&rdma->sc_send_wait); 2706c8c84f5SChuck Lever } 2716c8c84f5SChuck Lever 2726c8c84f5SChuck Lever /** 2734201c746SChuck Lever * svc_rdma_wc_send - Invoked by RDMA provider for each polled Send WC 2744201c746SChuck Lever * @cq: Completion Queue context 2754201c746SChuck Lever * @wc: Work Completion object 2764201c746SChuck Lever * 2774201c746SChuck Lever * NB: The svc_xprt/svcxprt_rdma is pinned whenever it's possible that 2784201c746SChuck Lever * the Send completion handler could be running. 2794201c746SChuck Lever */ 2804201c746SChuck Lever static void svc_rdma_wc_send(struct ib_cq *cq, struct ib_wc *wc) 2814201c746SChuck Lever { 2824201c746SChuck Lever struct svcxprt_rdma *rdma = cq->cq_context; 2834201c746SChuck Lever struct ib_cqe *cqe = wc->wr_cqe; 2843ac56c2fSChuck Lever struct svc_rdma_send_ctxt *ctxt = 2853ac56c2fSChuck Lever container_of(cqe, struct svc_rdma_send_ctxt, sc_cqe); 2864201c746SChuck Lever 2876c8c84f5SChuck Lever svc_rdma_wake_send_waiters(rdma, 1); 2882a1e4f21SChuck Lever 289e844d307SChuck Lever if (unlikely(wc->status != IB_WC_SUCCESS)) 290eef2d8d4SChuck Lever goto flushed; 291eef2d8d4SChuck Lever 292eef2d8d4SChuck Lever trace_svcrdma_wc_send(wc, &ctxt->sc_cid); 293c4b50cdfSChuck Lever svc_rdma_send_ctxt_put(rdma, ctxt); 294eef2d8d4SChuck Lever return; 295eef2d8d4SChuck Lever 296eef2d8d4SChuck Lever flushed: 297eef2d8d4SChuck Lever if (wc->status != IB_WC_WR_FLUSH_ERR) 298eef2d8d4SChuck Lever trace_svcrdma_wc_send_err(wc, &ctxt->sc_cid); 299eef2d8d4SChuck Lever else 300eef2d8d4SChuck Lever trace_svcrdma_wc_send_flush(wc, &ctxt->sc_cid); 301c4b50cdfSChuck Lever svc_rdma_send_ctxt_put(rdma, ctxt); 302e844d307SChuck Lever svc_xprt_deferred_close(&rdma->sc_xprt); 3034201c746SChuck Lever } 3044201c746SChuck Lever 3053abb03faSChuck Lever /** 3063abb03faSChuck Lever * svc_rdma_send - Post a single Send WR 3073abb03faSChuck Lever * @rdma: transport on which to post the WR 30817f70f8dSChuck Lever * @ctxt: send ctxt with a Send WR ready to post 3093abb03faSChuck Lever * 3102a1e4f21SChuck Lever * Returns zero if the Send WR was posted successfully. Otherwise, a 3113abb03faSChuck Lever * negative errno is returned. 3123abb03faSChuck Lever */ 31317f70f8dSChuck Lever int svc_rdma_send(struct svcxprt_rdma *rdma, struct svc_rdma_send_ctxt *ctxt) 3144201c746SChuck Lever { 31517f70f8dSChuck Lever struct ib_send_wr *wr = &ctxt->sc_send_wr; 3164201c746SChuck Lever int ret; 3174201c746SChuck Lever 318aee4b74aSChuck Lever /* Sync the transport header buffer */ 319aee4b74aSChuck Lever ib_dma_sync_single_for_device(rdma->sc_pd->device, 320aee4b74aSChuck Lever wr->sg_list[0].addr, 321aee4b74aSChuck Lever wr->sg_list[0].length, 322aee4b74aSChuck Lever DMA_TO_DEVICE); 323aee4b74aSChuck Lever 3244201c746SChuck Lever /* If the SQ is full, wait until an SQ entry is available */ 3254201c746SChuck Lever while (1) { 3263abb03faSChuck Lever if ((atomic_dec_return(&rdma->sc_sq_avail) < 0)) { 32722df5a22SChuck Lever percpu_counter_inc(&svcrdma_stat_sq_starve); 3284201c746SChuck Lever trace_svcrdma_sq_full(rdma); 3293abb03faSChuck Lever atomic_inc(&rdma->sc_sq_avail); 3304201c746SChuck Lever wait_event(rdma->sc_send_wait, 3313abb03faSChuck Lever atomic_read(&rdma->sc_sq_avail) > 1); 3324201c746SChuck Lever if (test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags)) 3334201c746SChuck Lever return -ENOTCONN; 3344201c746SChuck Lever trace_svcrdma_sq_retry(rdma); 3354201c746SChuck Lever continue; 3364201c746SChuck Lever } 3374201c746SChuck Lever 33817f70f8dSChuck Lever trace_svcrdma_post_send(ctxt); 339ed288d74SBart Van Assche ret = ib_post_send(rdma->sc_qp, wr, NULL); 340e28b4fc6SChuck Lever if (ret) 341e28b4fc6SChuck Lever break; 342e28b4fc6SChuck Lever return 0; 343e28b4fc6SChuck Lever } 344e28b4fc6SChuck Lever 345e28b4fc6SChuck Lever trace_svcrdma_sq_post_err(rdma, ret); 346e844d307SChuck Lever svc_xprt_deferred_close(&rdma->sc_xprt); 3474201c746SChuck Lever wake_up(&rdma->sc_send_wait); 3484201c746SChuck Lever return ret; 3494201c746SChuck Lever } 3504201c746SChuck Lever 3516fd5034dSChuck Lever /** 3526fd5034dSChuck Lever * svc_rdma_encode_read_list - Encode RPC Reply's Read chunk list 3536fd5034dSChuck Lever * @sctxt: Send context for the RPC Reply 3549a6a180bSChuck Lever * 3556fd5034dSChuck Lever * Return values: 3566fd5034dSChuck Lever * On success, returns length in bytes of the Reply XDR buffer 3576fd5034dSChuck Lever * that was consumed by the Reply Read list 3586fd5034dSChuck Lever * %-EMSGSIZE on XDR buffer overflow 3599a6a180bSChuck Lever */ 3606fd5034dSChuck Lever static ssize_t svc_rdma_encode_read_list(struct svc_rdma_send_ctxt *sctxt) 3616fd5034dSChuck Lever { 3626fd5034dSChuck Lever /* RPC-over-RDMA version 1 replies never have a Read list. */ 3636fd5034dSChuck Lever return xdr_stream_encode_item_absent(&sctxt->sc_stream); 3646fd5034dSChuck Lever } 3656fd5034dSChuck Lever 3666fd5034dSChuck Lever /** 3676fd5034dSChuck Lever * svc_rdma_encode_write_segment - Encode one Write segment 3686fd5034dSChuck Lever * @sctxt: Send context for the RPC Reply 3696911f3e1SChuck Lever * @chunk: Write chunk to push 3706fd5034dSChuck Lever * @remaining: remaining bytes of the payload left in the Write chunk 3716911f3e1SChuck Lever * @segno: which segment in the chunk 3726fd5034dSChuck Lever * 3736fd5034dSChuck Lever * Return values: 3746fd5034dSChuck Lever * On success, returns length in bytes of the Reply XDR buffer 3756911f3e1SChuck Lever * that was consumed by the Write segment, and updates @remaining 3766fd5034dSChuck Lever * %-EMSGSIZE on XDR buffer overflow 3776fd5034dSChuck Lever */ 3786911f3e1SChuck Lever static ssize_t svc_rdma_encode_write_segment(struct svc_rdma_send_ctxt *sctxt, 3796911f3e1SChuck Lever const struct svc_rdma_chunk *chunk, 3806911f3e1SChuck Lever u32 *remaining, unsigned int segno) 3816fd5034dSChuck Lever { 3826911f3e1SChuck Lever const struct svc_rdma_segment *segment = &chunk->ch_segments[segno]; 3836911f3e1SChuck Lever const size_t len = rpcrdma_segment_maxsz * sizeof(__be32); 3846911f3e1SChuck Lever u32 length; 3856fd5034dSChuck Lever __be32 *p; 3866fd5034dSChuck Lever 3876fd5034dSChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, len); 3886fd5034dSChuck Lever if (!p) 3896fd5034dSChuck Lever return -EMSGSIZE; 3906fd5034dSChuck Lever 3916911f3e1SChuck Lever length = min_t(u32, *remaining, segment->rs_length); 3926fd5034dSChuck Lever *remaining -= length; 3936911f3e1SChuck Lever xdr_encode_rdma_segment(p, segment->rs_handle, length, 3946911f3e1SChuck Lever segment->rs_offset); 3956911f3e1SChuck Lever trace_svcrdma_encode_wseg(sctxt, segno, segment->rs_handle, length, 3966911f3e1SChuck Lever segment->rs_offset); 3976fd5034dSChuck Lever return len; 3986fd5034dSChuck Lever } 3996fd5034dSChuck Lever 4006fd5034dSChuck Lever /** 4016fd5034dSChuck Lever * svc_rdma_encode_write_chunk - Encode one Write chunk 4026fd5034dSChuck Lever * @sctxt: Send context for the RPC Reply 4036911f3e1SChuck Lever * @chunk: Write chunk to push 4046fd5034dSChuck Lever * 4056fd5034dSChuck Lever * Copy a Write chunk from the Call transport header to the 4066fd5034dSChuck Lever * Reply transport header. Update each segment's length field 4076fd5034dSChuck Lever * to reflect the number of bytes written in that segment. 4086fd5034dSChuck Lever * 4096fd5034dSChuck Lever * Return values: 4106fd5034dSChuck Lever * On success, returns length in bytes of the Reply XDR buffer 4116fd5034dSChuck Lever * that was consumed by the Write chunk 4126fd5034dSChuck Lever * %-EMSGSIZE on XDR buffer overflow 4136fd5034dSChuck Lever */ 4146911f3e1SChuck Lever static ssize_t svc_rdma_encode_write_chunk(struct svc_rdma_send_ctxt *sctxt, 4156911f3e1SChuck Lever const struct svc_rdma_chunk *chunk) 4169a6a180bSChuck Lever { 4176911f3e1SChuck Lever u32 remaining = chunk->ch_payload_length; 4186911f3e1SChuck Lever unsigned int segno; 4196fd5034dSChuck Lever ssize_t len, ret; 4209a6a180bSChuck Lever 4216911f3e1SChuck Lever len = 0; 4226fd5034dSChuck Lever ret = xdr_stream_encode_item_present(&sctxt->sc_stream); 4236fd5034dSChuck Lever if (ret < 0) 4246911f3e1SChuck Lever return ret; 4256fd5034dSChuck Lever len += ret; 4266fd5034dSChuck Lever 4276911f3e1SChuck Lever ret = xdr_stream_encode_u32(&sctxt->sc_stream, chunk->ch_segcount); 4286fd5034dSChuck Lever if (ret < 0) 4296911f3e1SChuck Lever return ret; 4306fd5034dSChuck Lever len += ret; 4319a6a180bSChuck Lever 4326911f3e1SChuck Lever for (segno = 0; segno < chunk->ch_segcount; segno++) { 4336911f3e1SChuck Lever ret = svc_rdma_encode_write_segment(sctxt, chunk, &remaining, segno); 4346fd5034dSChuck Lever if (ret < 0) 4356911f3e1SChuck Lever return ret; 4366fd5034dSChuck Lever len += ret; 4379a6a180bSChuck Lever } 4389a6a180bSChuck Lever 4396fd5034dSChuck Lever return len; 4409a6a180bSChuck Lever } 4419a6a180bSChuck Lever 4426fd5034dSChuck Lever /** 4436fd5034dSChuck Lever * svc_rdma_encode_write_list - Encode RPC Reply's Write chunk list 4446fd5034dSChuck Lever * @rctxt: Reply context with information about the RPC Call 4456fd5034dSChuck Lever * @sctxt: Send context for the RPC Reply 4466fd5034dSChuck Lever * 4476fd5034dSChuck Lever * Return values: 4486fd5034dSChuck Lever * On success, returns length in bytes of the Reply XDR buffer 4496fd5034dSChuck Lever * that was consumed by the Reply's Write list 4506fd5034dSChuck Lever * %-EMSGSIZE on XDR buffer overflow 4519a6a180bSChuck Lever */ 4526911f3e1SChuck Lever static ssize_t svc_rdma_encode_write_list(struct svc_rdma_recv_ctxt *rctxt, 45376e5492bSChuck Lever struct svc_rdma_send_ctxt *sctxt) 4549a6a180bSChuck Lever { 4557a1cbfa1SChuck Lever struct svc_rdma_chunk *chunk; 4566fd5034dSChuck Lever ssize_t len, ret; 4579a6a180bSChuck Lever 458f6ad7759SChuck Lever len = 0; 4596911f3e1SChuck Lever pcl_for_each_chunk(chunk, &rctxt->rc_write_pcl) { 4606911f3e1SChuck Lever ret = svc_rdma_encode_write_chunk(sctxt, chunk); 4616fd5034dSChuck Lever if (ret < 0) 4626fd5034dSChuck Lever return ret; 4636911f3e1SChuck Lever len += ret; 464f6ad7759SChuck Lever } 4659a6a180bSChuck Lever 4666fd5034dSChuck Lever /* Terminate the Write list */ 4676fd5034dSChuck Lever ret = xdr_stream_encode_item_absent(&sctxt->sc_stream); 4686fd5034dSChuck Lever if (ret < 0) 4696fd5034dSChuck Lever return ret; 4706fd5034dSChuck Lever 4716fd5034dSChuck Lever return len + ret; 4729a6a180bSChuck Lever } 4739a6a180bSChuck Lever 4746fd5034dSChuck Lever /** 4756fd5034dSChuck Lever * svc_rdma_encode_reply_chunk - Encode RPC Reply's Reply chunk 4766fd5034dSChuck Lever * @rctxt: Reply context with information about the RPC Call 4776fd5034dSChuck Lever * @sctxt: Send context for the RPC Reply 4786fd5034dSChuck Lever * @length: size in bytes of the payload in the Reply chunk 4799a6a180bSChuck Lever * 4806fd5034dSChuck Lever * Return values: 4816fd5034dSChuck Lever * On success, returns length in bytes of the Reply XDR buffer 4826fd5034dSChuck Lever * that was consumed by the Reply's Reply chunk 4836fd5034dSChuck Lever * %-EMSGSIZE on XDR buffer overflow 4846911f3e1SChuck Lever * %-E2BIG if the RPC message is larger than the Reply chunk 4859a6a180bSChuck Lever */ 4866fd5034dSChuck Lever static ssize_t 4876911f3e1SChuck Lever svc_rdma_encode_reply_chunk(struct svc_rdma_recv_ctxt *rctxt, 4886fd5034dSChuck Lever struct svc_rdma_send_ctxt *sctxt, 4896fd5034dSChuck Lever unsigned int length) 4909a6a180bSChuck Lever { 4916911f3e1SChuck Lever struct svc_rdma_chunk *chunk; 4926911f3e1SChuck Lever 4936911f3e1SChuck Lever if (pcl_is_empty(&rctxt->rc_reply_pcl)) 494ded380f1SChuck Lever return xdr_stream_encode_item_absent(&sctxt->sc_stream); 495ded380f1SChuck Lever 4966911f3e1SChuck Lever chunk = pcl_first_chunk(&rctxt->rc_reply_pcl); 4976911f3e1SChuck Lever if (length > chunk->ch_length) 4986911f3e1SChuck Lever return -E2BIG; 4996911f3e1SChuck Lever 5006911f3e1SChuck Lever chunk->ch_payload_length = length; 5016911f3e1SChuck Lever return svc_rdma_encode_write_chunk(sctxt, chunk); 5029a6a180bSChuck Lever } 5039a6a180bSChuck Lever 5042371bcc0SChuck Lever struct svc_rdma_map_data { 5052371bcc0SChuck Lever struct svcxprt_rdma *md_rdma; 5062371bcc0SChuck Lever struct svc_rdma_send_ctxt *md_ctxt; 5072371bcc0SChuck Lever }; 5082371bcc0SChuck Lever 5092371bcc0SChuck Lever /** 5102371bcc0SChuck Lever * svc_rdma_page_dma_map - DMA map one page 5112371bcc0SChuck Lever * @data: pointer to arguments 5122371bcc0SChuck Lever * @page: struct page to DMA map 5132371bcc0SChuck Lever * @offset: offset into the page 5142371bcc0SChuck Lever * @len: number of bytes to map 5152371bcc0SChuck Lever * 5162371bcc0SChuck Lever * Returns: 5172371bcc0SChuck Lever * %0 if DMA mapping was successful 5182371bcc0SChuck Lever * %-EIO if the page cannot be DMA mapped 5192371bcc0SChuck Lever */ 5202371bcc0SChuck Lever static int svc_rdma_page_dma_map(void *data, struct page *page, 5212371bcc0SChuck Lever unsigned long offset, unsigned int len) 5226e6092caSChuck Lever { 5232371bcc0SChuck Lever struct svc_rdma_map_data *args = data; 5242371bcc0SChuck Lever struct svcxprt_rdma *rdma = args->md_rdma; 5252371bcc0SChuck Lever struct svc_rdma_send_ctxt *ctxt = args->md_ctxt; 5266e6092caSChuck Lever struct ib_device *dev = rdma->sc_cm_id->device; 5276e6092caSChuck Lever dma_addr_t dma_addr; 5286e6092caSChuck Lever 5292371bcc0SChuck Lever ++ctxt->sc_cur_sge_no; 5302371bcc0SChuck Lever 5316e6092caSChuck Lever dma_addr = ib_dma_map_page(dev, page, offset, len, DMA_TO_DEVICE); 5326e6092caSChuck Lever if (ib_dma_mapping_error(dev, dma_addr)) 53391a08eaeSChuck Lever goto out_maperr; 5346e6092caSChuck Lever 5352371bcc0SChuck Lever trace_svcrdma_dma_map_page(rdma, dma_addr, len); 53625fd86ecSChuck Lever ctxt->sc_sges[ctxt->sc_cur_sge_no].addr = dma_addr; 53725fd86ecSChuck Lever ctxt->sc_sges[ctxt->sc_cur_sge_no].length = len; 5384201c746SChuck Lever ctxt->sc_send_wr.num_sge++; 5396e6092caSChuck Lever return 0; 54091a08eaeSChuck Lever 54191a08eaeSChuck Lever out_maperr: 5422371bcc0SChuck Lever trace_svcrdma_dma_map_err(rdma, dma_addr, len); 54391a08eaeSChuck Lever return -EIO; 5446e6092caSChuck Lever } 5456e6092caSChuck Lever 5462371bcc0SChuck Lever /** 5472371bcc0SChuck Lever * svc_rdma_iov_dma_map - DMA map an iovec 5482371bcc0SChuck Lever * @data: pointer to arguments 5492371bcc0SChuck Lever * @iov: kvec to DMA map 5502371bcc0SChuck Lever * 5512371bcc0SChuck Lever * ib_dma_map_page() is used here because svc_rdma_dma_unmap() 552f016f305SChuck Lever * handles DMA-unmap and it uses ib_dma_unmap_page() exclusively. 5532371bcc0SChuck Lever * 5542371bcc0SChuck Lever * Returns: 5552371bcc0SChuck Lever * %0 if DMA mapping was successful 5562371bcc0SChuck Lever * %-EIO if the iovec cannot be DMA mapped 557f016f305SChuck Lever */ 5582371bcc0SChuck Lever static int svc_rdma_iov_dma_map(void *data, const struct kvec *iov) 559f016f305SChuck Lever { 5602371bcc0SChuck Lever if (!iov->iov_len) 5612371bcc0SChuck Lever return 0; 5622371bcc0SChuck Lever return svc_rdma_page_dma_map(data, virt_to_page(iov->iov_base), 5632371bcc0SChuck Lever offset_in_page(iov->iov_base), 5642371bcc0SChuck Lever iov->iov_len); 5652371bcc0SChuck Lever } 5662371bcc0SChuck Lever 5672371bcc0SChuck Lever /** 5682371bcc0SChuck Lever * svc_rdma_xb_dma_map - DMA map all segments of an xdr_buf 5692371bcc0SChuck Lever * @xdr: xdr_buf containing portion of an RPC message to transmit 5702371bcc0SChuck Lever * @data: pointer to arguments 5712371bcc0SChuck Lever * 5722371bcc0SChuck Lever * Returns: 5732371bcc0SChuck Lever * %0 if DMA mapping was successful 5742371bcc0SChuck Lever * %-EIO if DMA mapping failed 5752371bcc0SChuck Lever * 5762371bcc0SChuck Lever * On failure, any DMA mappings that have been already done must be 5772371bcc0SChuck Lever * unmapped by the caller. 5782371bcc0SChuck Lever */ 5792371bcc0SChuck Lever static int svc_rdma_xb_dma_map(const struct xdr_buf *xdr, void *data) 5802371bcc0SChuck Lever { 5812371bcc0SChuck Lever unsigned int len, remaining; 5822371bcc0SChuck Lever unsigned long pageoff; 5832371bcc0SChuck Lever struct page **ppages; 5842371bcc0SChuck Lever int ret; 5852371bcc0SChuck Lever 5862371bcc0SChuck Lever ret = svc_rdma_iov_dma_map(data, &xdr->head[0]); 5872371bcc0SChuck Lever if (ret < 0) 5882371bcc0SChuck Lever return ret; 5892371bcc0SChuck Lever 5902371bcc0SChuck Lever ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT); 5912371bcc0SChuck Lever pageoff = offset_in_page(xdr->page_base); 5922371bcc0SChuck Lever remaining = xdr->page_len; 5932371bcc0SChuck Lever while (remaining) { 5942371bcc0SChuck Lever len = min_t(u32, PAGE_SIZE - pageoff, remaining); 5952371bcc0SChuck Lever 5962371bcc0SChuck Lever ret = svc_rdma_page_dma_map(data, *ppages++, pageoff, len); 5972371bcc0SChuck Lever if (ret < 0) 5982371bcc0SChuck Lever return ret; 5992371bcc0SChuck Lever 6002371bcc0SChuck Lever remaining -= len; 6012371bcc0SChuck Lever pageoff = 0; 6022371bcc0SChuck Lever } 6032371bcc0SChuck Lever 6042371bcc0SChuck Lever ret = svc_rdma_iov_dma_map(data, &xdr->tail[0]); 6052371bcc0SChuck Lever if (ret < 0) 6062371bcc0SChuck Lever return ret; 6072371bcc0SChuck Lever 6082371bcc0SChuck Lever return xdr->len; 609f016f305SChuck Lever } 610f016f305SChuck Lever 6119d0b09d5SChuck Lever struct svc_rdma_pullup_data { 6129d0b09d5SChuck Lever u8 *pd_dest; 6139d0b09d5SChuck Lever unsigned int pd_length; 6149d0b09d5SChuck Lever unsigned int pd_num_sges; 6159d0b09d5SChuck Lever }; 6169d0b09d5SChuck Lever 6179d0b09d5SChuck Lever /** 6189d0b09d5SChuck Lever * svc_rdma_xb_count_sges - Count how many SGEs will be needed 6199d0b09d5SChuck Lever * @xdr: xdr_buf containing portion of an RPC message to transmit 6209d0b09d5SChuck Lever * @data: pointer to arguments 6219d0b09d5SChuck Lever * 6229d0b09d5SChuck Lever * Returns: 6239d0b09d5SChuck Lever * Number of SGEs needed to Send the contents of @xdr inline 6249d0b09d5SChuck Lever */ 6259d0b09d5SChuck Lever static int svc_rdma_xb_count_sges(const struct xdr_buf *xdr, 6269d0b09d5SChuck Lever void *data) 6279d0b09d5SChuck Lever { 6289d0b09d5SChuck Lever struct svc_rdma_pullup_data *args = data; 6299d0b09d5SChuck Lever unsigned int remaining; 6309d0b09d5SChuck Lever unsigned long offset; 6319d0b09d5SChuck Lever 6329d0b09d5SChuck Lever if (xdr->head[0].iov_len) 6339d0b09d5SChuck Lever ++args->pd_num_sges; 6349d0b09d5SChuck Lever 6359d0b09d5SChuck Lever offset = offset_in_page(xdr->page_base); 6369d0b09d5SChuck Lever remaining = xdr->page_len; 6379d0b09d5SChuck Lever while (remaining) { 6389d0b09d5SChuck Lever ++args->pd_num_sges; 6399d0b09d5SChuck Lever remaining -= min_t(u32, PAGE_SIZE - offset, remaining); 6409d0b09d5SChuck Lever offset = 0; 6419d0b09d5SChuck Lever } 6429d0b09d5SChuck Lever 6439d0b09d5SChuck Lever if (xdr->tail[0].iov_len) 6449d0b09d5SChuck Lever ++args->pd_num_sges; 6459d0b09d5SChuck Lever 6469d0b09d5SChuck Lever args->pd_length += xdr->len; 6479d0b09d5SChuck Lever return 0; 6489d0b09d5SChuck Lever } 6499d0b09d5SChuck Lever 6506e6092caSChuck Lever /** 6514554755eSChuck Lever * svc_rdma_pull_up_needed - Determine whether to use pull-up 6524554755eSChuck Lever * @rdma: controlling transport 6530dabe948SChuck Lever * @sctxt: send_ctxt for the Send WR 6544554755eSChuck Lever * @rctxt: Write and Reply chunks provided by client 6554554755eSChuck Lever * @xdr: xdr_buf containing RPC message to transmit 6564554755eSChuck Lever * 6574554755eSChuck Lever * Returns: 6584554755eSChuck Lever * %true if pull-up must be used 6594554755eSChuck Lever * %false otherwise 660e248aa7bSChuck Lever */ 6619d0b09d5SChuck Lever static bool svc_rdma_pull_up_needed(const struct svcxprt_rdma *rdma, 6629d0b09d5SChuck Lever const struct svc_rdma_send_ctxt *sctxt, 6634554755eSChuck Lever const struct svc_rdma_recv_ctxt *rctxt, 6649d0b09d5SChuck Lever const struct xdr_buf *xdr) 665e248aa7bSChuck Lever { 6669d0b09d5SChuck Lever /* Resources needed for the transport header */ 6679d0b09d5SChuck Lever struct svc_rdma_pullup_data args = { 6689d0b09d5SChuck Lever .pd_length = sctxt->sc_hdrbuf.len, 6699d0b09d5SChuck Lever .pd_num_sges = 1, 6709d0b09d5SChuck Lever }; 6719d0b09d5SChuck Lever int ret; 672e248aa7bSChuck Lever 6739d0b09d5SChuck Lever ret = pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, 6749d0b09d5SChuck Lever svc_rdma_xb_count_sges, &args); 6759d0b09d5SChuck Lever if (ret < 0) 6769d0b09d5SChuck Lever return false; 6779d0b09d5SChuck Lever 6789d0b09d5SChuck Lever if (args.pd_length < RPCRDMA_PULLUP_THRESH) 6790dabe948SChuck Lever return true; 6809d0b09d5SChuck Lever return args.pd_num_sges >= rdma->sc_max_send_sges; 6819d0b09d5SChuck Lever } 6820dabe948SChuck Lever 6839d0b09d5SChuck Lever /** 6849d0b09d5SChuck Lever * svc_rdma_xb_linearize - Copy region of xdr_buf to flat buffer 6859d0b09d5SChuck Lever * @xdr: xdr_buf containing portion of an RPC message to copy 6869d0b09d5SChuck Lever * @data: pointer to arguments 6879d0b09d5SChuck Lever * 6889d0b09d5SChuck Lever * Returns: 6899d0b09d5SChuck Lever * Always zero. 6900dabe948SChuck Lever */ 6919d0b09d5SChuck Lever static int svc_rdma_xb_linearize(const struct xdr_buf *xdr, 6929d0b09d5SChuck Lever void *data) 6939d0b09d5SChuck Lever { 6949d0b09d5SChuck Lever struct svc_rdma_pullup_data *args = data; 6959d0b09d5SChuck Lever unsigned int len, remaining; 696e248aa7bSChuck Lever unsigned long pageoff; 6979d0b09d5SChuck Lever struct page **ppages; 698e248aa7bSChuck Lever 6999d0b09d5SChuck Lever if (xdr->head[0].iov_len) { 7009d0b09d5SChuck Lever memcpy(args->pd_dest, xdr->head[0].iov_base, xdr->head[0].iov_len); 7019d0b09d5SChuck Lever args->pd_dest += xdr->head[0].iov_len; 7029d0b09d5SChuck Lever } 7039d0b09d5SChuck Lever 7049d0b09d5SChuck Lever ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT); 7059d0b09d5SChuck Lever pageoff = offset_in_page(xdr->page_base); 706e248aa7bSChuck Lever remaining = xdr->page_len; 707e248aa7bSChuck Lever while (remaining) { 7089d0b09d5SChuck Lever len = min_t(u32, PAGE_SIZE - pageoff, remaining); 7099d0b09d5SChuck Lever memcpy(args->pd_dest, page_address(*ppages) + pageoff, len); 7109d0b09d5SChuck Lever remaining -= len; 7119d0b09d5SChuck Lever args->pd_dest += len; 712e248aa7bSChuck Lever pageoff = 0; 7139d0b09d5SChuck Lever ppages++; 714e248aa7bSChuck Lever } 715e248aa7bSChuck Lever 7169d0b09d5SChuck Lever if (xdr->tail[0].iov_len) { 7179d0b09d5SChuck Lever memcpy(args->pd_dest, xdr->tail[0].iov_base, xdr->tail[0].iov_len); 7189d0b09d5SChuck Lever args->pd_dest += xdr->tail[0].iov_len; 7199d0b09d5SChuck Lever } 720e248aa7bSChuck Lever 7219d0b09d5SChuck Lever args->pd_length += xdr->len; 7229d0b09d5SChuck Lever return 0; 723e248aa7bSChuck Lever } 724e248aa7bSChuck Lever 7254554755eSChuck Lever /** 7264554755eSChuck Lever * svc_rdma_pull_up_reply_msg - Copy Reply into a single buffer 7274554755eSChuck Lever * @rdma: controlling transport 7284554755eSChuck Lever * @sctxt: send_ctxt for the Send WR; xprt hdr is already prepared 7294554755eSChuck Lever * @rctxt: Write and Reply chunks provided by client 7304554755eSChuck Lever * @xdr: prepared xdr_buf containing RPC message 7314554755eSChuck Lever * 7324554755eSChuck Lever * The device is not capable of sending the reply directly. 7334554755eSChuck Lever * Assemble the elements of @xdr into the transport header buffer. 7344554755eSChuck Lever * 7359d0b09d5SChuck Lever * Assumptions: 7369d0b09d5SChuck Lever * pull_up_needed has determined that @xdr will fit in the buffer. 7379d0b09d5SChuck Lever * 7389d0b09d5SChuck Lever * Returns: 7399d0b09d5SChuck Lever * %0 if pull-up was successful 7409d0b09d5SChuck Lever * %-EMSGSIZE if a buffer manipulation problem occurred 741e248aa7bSChuck Lever */ 7429d0b09d5SChuck Lever static int svc_rdma_pull_up_reply_msg(const struct svcxprt_rdma *rdma, 7434554755eSChuck Lever struct svc_rdma_send_ctxt *sctxt, 7444554755eSChuck Lever const struct svc_rdma_recv_ctxt *rctxt, 7454554755eSChuck Lever const struct xdr_buf *xdr) 746e248aa7bSChuck Lever { 7479d0b09d5SChuck Lever struct svc_rdma_pullup_data args = { 7489d0b09d5SChuck Lever .pd_dest = sctxt->sc_xprt_buf + sctxt->sc_hdrbuf.len, 7499d0b09d5SChuck Lever }; 7509d0b09d5SChuck Lever int ret; 751e248aa7bSChuck Lever 7529d0b09d5SChuck Lever ret = pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, 7539d0b09d5SChuck Lever svc_rdma_xb_linearize, &args); 7549d0b09d5SChuck Lever if (ret < 0) 7559d0b09d5SChuck Lever return ret; 756e248aa7bSChuck Lever 7579d0b09d5SChuck Lever sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len + args.pd_length; 7589d0b09d5SChuck Lever trace_svcrdma_send_pullup(sctxt, args.pd_length); 759e248aa7bSChuck Lever return 0; 760e248aa7bSChuck Lever } 761e248aa7bSChuck Lever 7624554755eSChuck Lever /* svc_rdma_map_reply_msg - DMA map the buffer holding RPC message 76399722fe4SChuck Lever * @rdma: controlling transport 7644554755eSChuck Lever * @sctxt: send_ctxt for the Send WR 7654554755eSChuck Lever * @rctxt: Write and Reply chunks provided by client 76699722fe4SChuck Lever * @xdr: prepared xdr_buf containing RPC message 76799722fe4SChuck Lever * 7682371bcc0SChuck Lever * Returns: 7692371bcc0SChuck Lever * %0 if DMA mapping was successful. 7702371bcc0SChuck Lever * %-EMSGSIZE if a buffer manipulation problem occurred 7712371bcc0SChuck Lever * %-EIO if DMA mapping failed 7729a6a180bSChuck Lever * 7732371bcc0SChuck Lever * The Send WR's num_sge field is set in all cases. 774c06b540aSTom Tucker */ 77599722fe4SChuck Lever int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma, 7764554755eSChuck Lever struct svc_rdma_send_ctxt *sctxt, 7774554755eSChuck Lever const struct svc_rdma_recv_ctxt *rctxt, 7782371bcc0SChuck Lever const struct xdr_buf *xdr) 779c06b540aSTom Tucker { 7802371bcc0SChuck Lever struct svc_rdma_map_data args = { 7812371bcc0SChuck Lever .md_rdma = rdma, 7822371bcc0SChuck Lever .md_ctxt = sctxt, 7832371bcc0SChuck Lever }; 784c06b540aSTom Tucker 785aee4b74aSChuck Lever /* Set up the (persistently-mapped) transport header SGE. */ 786aee4b74aSChuck Lever sctxt->sc_send_wr.num_sge = 1; 787aee4b74aSChuck Lever sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len; 788aee4b74aSChuck Lever 789aee4b74aSChuck Lever /* If there is a Reply chunk, nothing follows the transport 790aee4b74aSChuck Lever * header, and we're done here. 791aee4b74aSChuck Lever */ 7922371bcc0SChuck Lever if (!pcl_is_empty(&rctxt->rc_reply_pcl)) 793aee4b74aSChuck Lever return 0; 794aee4b74aSChuck Lever 795aee4b74aSChuck Lever /* For pull-up, svc_rdma_send() will sync the transport header. 796aee4b74aSChuck Lever * No additional DMA mapping is necessary. 797aee4b74aSChuck Lever */ 7980dabe948SChuck Lever if (svc_rdma_pull_up_needed(rdma, sctxt, rctxt, xdr)) 7994554755eSChuck Lever return svc_rdma_pull_up_reply_msg(rdma, sctxt, rctxt, xdr); 800e248aa7bSChuck Lever 8012371bcc0SChuck Lever return pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, 8022371bcc0SChuck Lever svc_rdma_xb_dma_map, &args); 803c06b540aSTom Tucker } 804c06b540aSTom Tucker 805a944209cSChuck Lever /* The svc_rqst and all resources it owns are released as soon as 806a944209cSChuck Lever * svc_rdma_sendto returns. Transfer pages under I/O to the ctxt 807a944209cSChuck Lever * so they are released by the Send completion handler. 808a944209cSChuck Lever */ 809c4b50cdfSChuck Lever static void svc_rdma_save_io_pages(struct svc_rqst *rqstp, 810a944209cSChuck Lever struct svc_rdma_send_ctxt *ctxt) 811a944209cSChuck Lever { 812a944209cSChuck Lever int i, pages = rqstp->rq_next_page - rqstp->rq_respages; 813a944209cSChuck Lever 814a944209cSChuck Lever ctxt->sc_page_count += pages; 815a944209cSChuck Lever for (i = 0; i < pages; i++) { 816a944209cSChuck Lever ctxt->sc_pages[i] = rqstp->rq_respages[i]; 817a944209cSChuck Lever rqstp->rq_respages[i] = NULL; 818a944209cSChuck Lever } 819a944209cSChuck Lever 820a944209cSChuck Lever /* Prevent svc_xprt_release from releasing pages in rq_pages */ 821a944209cSChuck Lever rqstp->rq_next_page = rqstp->rq_respages; 822a944209cSChuck Lever } 823a944209cSChuck Lever 8249a6a180bSChuck Lever /* Prepare the portion of the RPC Reply that will be transmitted 8259a6a180bSChuck Lever * via RDMA Send. The RPC-over-RDMA transport header is prepared 8264201c746SChuck Lever * in sc_sges[0], and the RPC xdr_buf is prepared in following sges. 8279a6a180bSChuck Lever * 8289a6a180bSChuck Lever * Depending on whether a Write list or Reply chunk is present, 8299a6a180bSChuck Lever * the server may send all, a portion of, or none of the xdr_buf. 8304201c746SChuck Lever * In the latter case, only the transport header (sc_sges[0]) is 8319a6a180bSChuck Lever * transmitted. 8329a6a180bSChuck Lever * 8339a6a180bSChuck Lever * RDMA Send is the last step of transmitting an RPC reply. Pages 8349a6a180bSChuck Lever * involved in the earlier RDMA Writes are here transferred out 83597bce634SChuck Lever * of the rqstp and into the sctxt's page array. These pages are 8369a6a180bSChuck Lever * DMA unmapped by each Write completion, but the subsequent Send 8379a6a180bSChuck Lever * completion finally releases these pages. 8389a6a180bSChuck Lever * 8399a6a180bSChuck Lever * Assumptions: 8409a6a180bSChuck Lever * - The Reply's transport header will never be larger than a page. 841c06b540aSTom Tucker */ 8429a6a180bSChuck Lever static int svc_rdma_send_reply_msg(struct svcxprt_rdma *rdma, 84397bce634SChuck Lever struct svc_rdma_send_ctxt *sctxt, 844db9602e4SChuck Lever const struct svc_rdma_recv_ctxt *rctxt, 845db9602e4SChuck Lever struct svc_rqst *rqstp) 846c06b540aSTom Tucker { 8479a6a180bSChuck Lever int ret; 8480e7f011aSTom Tucker 849aee4b74aSChuck Lever ret = svc_rdma_map_reply_msg(rdma, sctxt, rctxt, &rqstp->rq_res); 8509a6a180bSChuck Lever if (ret < 0) 85199722fe4SChuck Lever return ret; 852c06b540aSTom Tucker 853c4b50cdfSChuck Lever svc_rdma_save_io_pages(rqstp, sctxt); 854c4b50cdfSChuck Lever 85597bce634SChuck Lever if (rctxt->rc_inv_rkey) { 85697bce634SChuck Lever sctxt->sc_send_wr.opcode = IB_WR_SEND_WITH_INV; 85797bce634SChuck Lever sctxt->sc_send_wr.ex.invalidate_rkey = rctxt->rc_inv_rkey; 85897bce634SChuck Lever } else { 85997bce634SChuck Lever sctxt->sc_send_wr.opcode = IB_WR_SEND; 860986b7889SChuck Lever } 8612a1e4f21SChuck Lever 862c4b50cdfSChuck Lever return svc_rdma_send(rdma, sctxt); 863c06b540aSTom Tucker } 864c06b540aSTom Tucker 865c65b326bSChuck Lever /** 866c65b326bSChuck Lever * svc_rdma_send_error_msg - Send an RPC/RDMA v1 error response 867c65b326bSChuck Lever * @rdma: controlling transport context 868c65b326bSChuck Lever * @sctxt: Send context for the response 869c65b326bSChuck Lever * @rctxt: Receive context for incoming bad message 870c65b326bSChuck Lever * @status: negative errno indicating error that occurred 8714757d90bSChuck Lever * 872c65b326bSChuck Lever * Given the client-provided Read, Write, and Reply chunks, the 873c65b326bSChuck Lever * server was not able to parse the Call or form a complete Reply. 874c65b326bSChuck Lever * Return an RDMA_ERROR message so the client can retire the RPC 875c65b326bSChuck Lever * transaction. 876c65b326bSChuck Lever * 877c65b326bSChuck Lever * The caller does not have to release @sctxt. It is released by 878c65b326bSChuck Lever * Send completion, or by this function on error. 8794757d90bSChuck Lever */ 880c65b326bSChuck Lever void svc_rdma_send_error_msg(struct svcxprt_rdma *rdma, 881d1f6e236SChuck Lever struct svc_rdma_send_ctxt *sctxt, 8824f200bd8SChuck Lever struct svc_rdma_recv_ctxt *rctxt, 8834f200bd8SChuck Lever int status) 8844757d90bSChuck Lever { 8856fd5034dSChuck Lever __be32 *rdma_argp = rctxt->rc_recv_buf; 8864757d90bSChuck Lever __be32 *p; 8874757d90bSChuck Lever 888d1f6e236SChuck Lever rpcrdma_set_xdrlen(&sctxt->sc_hdrbuf, 0); 889d1f6e236SChuck Lever xdr_init_encode(&sctxt->sc_stream, &sctxt->sc_hdrbuf, 890d1f6e236SChuck Lever sctxt->sc_xprt_buf, NULL); 8916fd5034dSChuck Lever 8924f200bd8SChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, 8934f200bd8SChuck Lever rpcrdma_fixed_maxsz * sizeof(*p)); 8946fd5034dSChuck Lever if (!p) 895605c61beSChuck Lever goto put_ctxt; 8966fd5034dSChuck Lever 8976fd5034dSChuck Lever *p++ = *rdma_argp; 8986fd5034dSChuck Lever *p++ = *(rdma_argp + 1); 8996fd5034dSChuck Lever *p++ = rdma->sc_fc_credits; 9004f200bd8SChuck Lever *p = rdma_error; 9014f200bd8SChuck Lever 9024f200bd8SChuck Lever switch (status) { 9034f200bd8SChuck Lever case -EPROTONOSUPPORT: 9044f200bd8SChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, 3 * sizeof(*p)); 9054f200bd8SChuck Lever if (!p) 906605c61beSChuck Lever goto put_ctxt; 9074f200bd8SChuck Lever 9084f200bd8SChuck Lever *p++ = err_vers; 9094f200bd8SChuck Lever *p++ = rpcrdma_version; 9104f200bd8SChuck Lever *p = rpcrdma_version; 9114f200bd8SChuck Lever trace_svcrdma_err_vers(*rdma_argp); 9124f200bd8SChuck Lever break; 9134f200bd8SChuck Lever default: 9144f200bd8SChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, sizeof(*p)); 9154f200bd8SChuck Lever if (!p) 916605c61beSChuck Lever goto put_ctxt; 9174f200bd8SChuck Lever 9184757d90bSChuck Lever *p = err_chunk; 9196fd5034dSChuck Lever trace_svcrdma_err_chunk(*rdma_argp); 9204f200bd8SChuck Lever } 9216fd5034dSChuck Lever 922c65b326bSChuck Lever /* Remote Invalidation is skipped for simplicity. */ 923d1f6e236SChuck Lever sctxt->sc_send_wr.num_sge = 1; 924d1f6e236SChuck Lever sctxt->sc_send_wr.opcode = IB_WR_SEND; 925d1f6e236SChuck Lever sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len; 92617f70f8dSChuck Lever if (svc_rdma_send(rdma, sctxt)) 927605c61beSChuck Lever goto put_ctxt; 928c4b50cdfSChuck Lever return; 929605c61beSChuck Lever 930605c61beSChuck Lever put_ctxt: 931605c61beSChuck Lever svc_rdma_send_ctxt_put(rdma, sctxt); 93299722fe4SChuck Lever } 93399722fe4SChuck Lever 9349a6a180bSChuck Lever /** 9359a6a180bSChuck Lever * svc_rdma_sendto - Transmit an RPC reply 9369a6a180bSChuck Lever * @rqstp: processed RPC request, reply XDR already in ::rq_res 9379a6a180bSChuck Lever * 9389a6a180bSChuck Lever * Any resources still associated with @rqstp are released upon return. 9399a6a180bSChuck Lever * If no reply message was possible, the connection is closed. 9409a6a180bSChuck Lever * 9419a6a180bSChuck Lever * Returns: 9429a6a180bSChuck Lever * %0 if an RPC reply has been successfully posted, 9439a6a180bSChuck Lever * %-ENOMEM if a resource shortage occurred (connection is lost), 9449a6a180bSChuck Lever * %-ENOTCONN if posting failed (connection is lost). 9459a6a180bSChuck Lever */ 946c06b540aSTom Tucker int svc_rdma_sendto(struct svc_rqst *rqstp) 947c06b540aSTom Tucker { 948c06b540aSTom Tucker struct svc_xprt *xprt = rqstp->rq_xprt; 949c06b540aSTom Tucker struct svcxprt_rdma *rdma = 950c06b540aSTom Tucker container_of(xprt, struct svcxprt_rdma, sc_xprt); 9513a88092eSChuck Lever struct svc_rdma_recv_ctxt *rctxt = rqstp->rq_xprt_ctxt; 9522fe8c446SChuck Lever __be32 *rdma_argp = rctxt->rc_recv_buf; 95399722fe4SChuck Lever struct svc_rdma_send_ctxt *sctxt; 9548727f788SChuck Lever unsigned int rc_size; 9556fd5034dSChuck Lever __be32 *p; 9569a6a180bSChuck Lever int ret; 957c06b540aSTom Tucker 958ca4faf54SChuck Lever ret = -ENOTCONN; 959ca4faf54SChuck Lever if (svc_xprt_is_dead(xprt)) 960c7731d5eSChuck Lever goto drop_connection; 961ca4faf54SChuck Lever 96278da2b3cSChuck Lever ret = -ENOMEM; 96399722fe4SChuck Lever sctxt = svc_rdma_send_ctxt_get(rdma); 96499722fe4SChuck Lever if (!sctxt) 965c7731d5eSChuck Lever goto drop_connection; 96698fc21d3SChuck Lever 9678727f788SChuck Lever ret = -EMSGSIZE; 9686fd5034dSChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, 9696fd5034dSChuck Lever rpcrdma_fixed_maxsz * sizeof(*p)); 9706fd5034dSChuck Lever if (!p) 971c7731d5eSChuck Lever goto put_ctxt; 972ded380f1SChuck Lever 973ded380f1SChuck Lever ret = svc_rdma_send_reply_chunk(rdma, rctxt, &rqstp->rq_res); 974ded380f1SChuck Lever if (ret < 0) 975c7731d5eSChuck Lever goto reply_chunk; 9768727f788SChuck Lever rc_size = ret; 977ded380f1SChuck Lever 9789a6a180bSChuck Lever *p++ = *rdma_argp; 9799a6a180bSChuck Lever *p++ = *(rdma_argp + 1); 98098fc21d3SChuck Lever *p++ = rdma->sc_fc_credits; 9816911f3e1SChuck Lever *p = pcl_is_empty(&rctxt->rc_reply_pcl) ? rdma_msg : rdma_nomsg; 98298fc21d3SChuck Lever 9838727f788SChuck Lever ret = svc_rdma_encode_read_list(sctxt); 9848727f788SChuck Lever if (ret < 0) 985c7731d5eSChuck Lever goto put_ctxt; 9868727f788SChuck Lever ret = svc_rdma_encode_write_list(rctxt, sctxt); 9878727f788SChuck Lever if (ret < 0) 988c7731d5eSChuck Lever goto put_ctxt; 9898727f788SChuck Lever ret = svc_rdma_encode_reply_chunk(rctxt, sctxt, rc_size); 9908727f788SChuck Lever if (ret < 0) 991c7731d5eSChuck Lever goto put_ctxt; 992c06b540aSTom Tucker 993db9602e4SChuck Lever ret = svc_rdma_send_reply_msg(rdma, sctxt, rctxt, rqstp); 9943e1eeb98SChuck Lever if (ret < 0) 995c7731d5eSChuck Lever goto put_ctxt; 99623cf1ee1SChuck Lever return 0; 997afd566eaSTom Tucker 998c7731d5eSChuck Lever reply_chunk: 999b20dae70SColin Ian King if (ret != -E2BIG && ret != -EINVAL) 1000c7731d5eSChuck Lever goto put_ctxt; 10014757d90bSChuck Lever 1002c4b50cdfSChuck Lever /* Send completion releases payload pages that were part 1003c4b50cdfSChuck Lever * of previously posted RDMA Writes. 1004c4b50cdfSChuck Lever */ 1005c4b50cdfSChuck Lever svc_rdma_save_io_pages(rqstp, sctxt); 1006605c61beSChuck Lever svc_rdma_send_error_msg(rdma, sctxt, rctxt, ret); 100723cf1ee1SChuck Lever return 0; 10084757d90bSChuck Lever 1009c7731d5eSChuck Lever put_ctxt: 101099722fe4SChuck Lever svc_rdma_send_ctxt_put(rdma, sctxt); 1011c7731d5eSChuck Lever drop_connection: 10123f8f25c6SChuck Lever trace_svcrdma_send_err(rqstp, ret); 1013e844d307SChuck Lever svc_xprt_deferred_close(&rdma->sc_xprt); 101423cf1ee1SChuck Lever return -ENOTCONN; 1015c06b540aSTom Tucker } 101641205539SChuck Lever 101741205539SChuck Lever /** 101803493bcaSChuck Lever * svc_rdma_result_payload - special processing for a result payload 101941205539SChuck Lever * @rqstp: svc_rqst to operate on 102041205539SChuck Lever * @offset: payload's byte offset in @xdr 102141205539SChuck Lever * @length: size of payload, in bytes 102241205539SChuck Lever * 1023f6ad7759SChuck Lever * Return values: 1024f6ad7759SChuck Lever * %0 if successful or nothing needed to be done 1025f6ad7759SChuck Lever * %-EMSGSIZE on XDR buffer overflow 1026f6ad7759SChuck Lever * %-E2BIG if the payload was larger than the Write chunk 1027f6ad7759SChuck Lever * %-EINVAL if client provided too many segments 1028f6ad7759SChuck Lever * %-ENOMEM if rdma_rw context pool was exhausted 1029f6ad7759SChuck Lever * %-ENOTCONN if posting failed (connection is lost) 1030f6ad7759SChuck Lever * %-EIO if rdma_rw initialization failed (DMA mapping, etc) 103141205539SChuck Lever */ 103203493bcaSChuck Lever int svc_rdma_result_payload(struct svc_rqst *rqstp, unsigned int offset, 103341205539SChuck Lever unsigned int length) 103441205539SChuck Lever { 103541205539SChuck Lever struct svc_rdma_recv_ctxt *rctxt = rqstp->rq_xprt_ctxt; 10367a1cbfa1SChuck Lever struct svc_rdma_chunk *chunk; 1037f6ad7759SChuck Lever struct svcxprt_rdma *rdma; 1038f6ad7759SChuck Lever struct xdr_buf subbuf; 1039f6ad7759SChuck Lever int ret; 1040f6ad7759SChuck Lever 10417a1cbfa1SChuck Lever chunk = rctxt->rc_cur_result_payload; 10427a1cbfa1SChuck Lever if (!length || !chunk) 1043f6ad7759SChuck Lever return 0; 10447a1cbfa1SChuck Lever rctxt->rc_cur_result_payload = 10457a1cbfa1SChuck Lever pcl_next_chunk(&rctxt->rc_write_pcl, chunk); 10467a1cbfa1SChuck Lever if (length > chunk->ch_length) 10477a1cbfa1SChuck Lever return -E2BIG; 104841205539SChuck Lever 10497a1cbfa1SChuck Lever chunk->ch_position = offset; 10507a1cbfa1SChuck Lever chunk->ch_payload_length = length; 105141205539SChuck Lever 1052f6ad7759SChuck Lever if (xdr_buf_subsegment(&rqstp->rq_res, &subbuf, offset, length)) 1053f6ad7759SChuck Lever return -EMSGSIZE; 1054f6ad7759SChuck Lever 1055f6ad7759SChuck Lever rdma = container_of(rqstp->rq_xprt, struct svcxprt_rdma, sc_xprt); 10567a1cbfa1SChuck Lever ret = svc_rdma_send_write_chunk(rdma, chunk, &subbuf); 1057f6ad7759SChuck Lever if (ret < 0) 1058f6ad7759SChuck Lever return ret; 105941205539SChuck Lever return 0; 106041205539SChuck Lever } 1061