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 114c06b540aSTom Tucker #define RPCDBG_FACILITY RPCDBG_SVCXPRT 115c06b540aSTom Tucker 1164201c746SChuck Lever static void svc_rdma_wc_send(struct ib_cq *cq, struct ib_wc *wc); 1174201c746SChuck Lever 1184201c746SChuck Lever static inline struct svc_rdma_send_ctxt * 1194201c746SChuck Lever svc_rdma_next_send_ctxt(struct list_head *list) 1204201c746SChuck Lever { 1214201c746SChuck Lever return list_first_entry_or_null(list, struct svc_rdma_send_ctxt, 1224201c746SChuck Lever sc_list); 1234201c746SChuck Lever } 1244201c746SChuck Lever 1253ac56c2fSChuck Lever static void svc_rdma_send_cid_init(struct svcxprt_rdma *rdma, 1263ac56c2fSChuck Lever struct rpc_rdma_cid *cid) 1273ac56c2fSChuck Lever { 1283ac56c2fSChuck Lever cid->ci_queue_id = rdma->sc_sq_cq->res.id; 1293ac56c2fSChuck Lever cid->ci_completion_id = atomic_inc_return(&rdma->sc_completion_ids); 1303ac56c2fSChuck Lever } 1313ac56c2fSChuck Lever 1324201c746SChuck Lever static struct svc_rdma_send_ctxt * 1334201c746SChuck Lever svc_rdma_send_ctxt_alloc(struct svcxprt_rdma *rdma) 1344201c746SChuck Lever { 1354201c746SChuck Lever struct svc_rdma_send_ctxt *ctxt; 13699722fe4SChuck Lever dma_addr_t addr; 13799722fe4SChuck Lever void *buffer; 13825fd86ecSChuck Lever size_t size; 1394201c746SChuck Lever int i; 1404201c746SChuck Lever 14125fd86ecSChuck Lever size = sizeof(*ctxt); 14225fd86ecSChuck Lever size += rdma->sc_max_send_sges * sizeof(struct ib_sge); 14325fd86ecSChuck Lever ctxt = kmalloc(size, GFP_KERNEL); 1444201c746SChuck Lever if (!ctxt) 14599722fe4SChuck Lever goto fail0; 14699722fe4SChuck Lever buffer = kmalloc(rdma->sc_max_req_size, GFP_KERNEL); 14799722fe4SChuck Lever if (!buffer) 14899722fe4SChuck Lever goto fail1; 14999722fe4SChuck Lever addr = ib_dma_map_single(rdma->sc_pd->device, buffer, 15099722fe4SChuck Lever rdma->sc_max_req_size, DMA_TO_DEVICE); 15199722fe4SChuck Lever if (ib_dma_mapping_error(rdma->sc_pd->device, addr)) 15299722fe4SChuck Lever goto fail2; 1534201c746SChuck Lever 1543ac56c2fSChuck Lever svc_rdma_send_cid_init(rdma, &ctxt->sc_cid); 1553ac56c2fSChuck Lever 1564201c746SChuck Lever ctxt->sc_send_wr.next = NULL; 1574201c746SChuck Lever ctxt->sc_send_wr.wr_cqe = &ctxt->sc_cqe; 1584201c746SChuck Lever ctxt->sc_send_wr.sg_list = ctxt->sc_sges; 1594201c746SChuck Lever ctxt->sc_send_wr.send_flags = IB_SEND_SIGNALED; 16099722fe4SChuck Lever ctxt->sc_cqe.done = svc_rdma_wc_send; 16199722fe4SChuck Lever ctxt->sc_xprt_buf = buffer; 1626fd5034dSChuck Lever xdr_buf_init(&ctxt->sc_hdrbuf, ctxt->sc_xprt_buf, 1636fd5034dSChuck Lever rdma->sc_max_req_size); 16499722fe4SChuck Lever ctxt->sc_sges[0].addr = addr; 16599722fe4SChuck Lever 16625fd86ecSChuck Lever for (i = 0; i < rdma->sc_max_send_sges; i++) 1674201c746SChuck Lever ctxt->sc_sges[i].lkey = rdma->sc_pd->local_dma_lkey; 1684201c746SChuck Lever return ctxt; 16999722fe4SChuck Lever 17099722fe4SChuck Lever fail2: 17199722fe4SChuck Lever kfree(buffer); 17299722fe4SChuck Lever fail1: 17399722fe4SChuck Lever kfree(ctxt); 17499722fe4SChuck Lever fail0: 17599722fe4SChuck Lever return NULL; 1764201c746SChuck Lever } 1774201c746SChuck Lever 1784201c746SChuck Lever /** 1794201c746SChuck Lever * svc_rdma_send_ctxts_destroy - Release all send_ctxt's for an xprt 1804201c746SChuck Lever * @rdma: svcxprt_rdma being torn down 1814201c746SChuck Lever * 1824201c746SChuck Lever */ 1834201c746SChuck Lever void svc_rdma_send_ctxts_destroy(struct svcxprt_rdma *rdma) 1844201c746SChuck Lever { 1854201c746SChuck Lever struct svc_rdma_send_ctxt *ctxt; 1864201c746SChuck Lever 1874201c746SChuck Lever while ((ctxt = svc_rdma_next_send_ctxt(&rdma->sc_send_ctxts))) { 1884201c746SChuck Lever list_del(&ctxt->sc_list); 18999722fe4SChuck Lever ib_dma_unmap_single(rdma->sc_pd->device, 19099722fe4SChuck Lever ctxt->sc_sges[0].addr, 19199722fe4SChuck Lever rdma->sc_max_req_size, 19299722fe4SChuck Lever DMA_TO_DEVICE); 19399722fe4SChuck Lever kfree(ctxt->sc_xprt_buf); 1944201c746SChuck Lever kfree(ctxt); 1954201c746SChuck Lever } 1964201c746SChuck Lever } 1974201c746SChuck Lever 1984201c746SChuck Lever /** 1994201c746SChuck Lever * svc_rdma_send_ctxt_get - Get a free send_ctxt 2004201c746SChuck Lever * @rdma: controlling svcxprt_rdma 2014201c746SChuck Lever * 2024201c746SChuck Lever * Returns a ready-to-use send_ctxt, or NULL if none are 2034201c746SChuck Lever * available and a fresh one cannot be allocated. 2044201c746SChuck Lever */ 2054201c746SChuck Lever struct svc_rdma_send_ctxt *svc_rdma_send_ctxt_get(struct svcxprt_rdma *rdma) 2064201c746SChuck Lever { 2074201c746SChuck Lever struct svc_rdma_send_ctxt *ctxt; 2084201c746SChuck Lever 2094201c746SChuck Lever spin_lock(&rdma->sc_send_lock); 2104201c746SChuck Lever ctxt = svc_rdma_next_send_ctxt(&rdma->sc_send_ctxts); 2114201c746SChuck Lever if (!ctxt) 2124201c746SChuck Lever goto out_empty; 2134201c746SChuck Lever list_del(&ctxt->sc_list); 2144201c746SChuck Lever spin_unlock(&rdma->sc_send_lock); 2154201c746SChuck Lever 2164201c746SChuck Lever out: 2176fd5034dSChuck Lever rpcrdma_set_xdrlen(&ctxt->sc_hdrbuf, 0); 2186fd5034dSChuck Lever xdr_init_encode(&ctxt->sc_stream, &ctxt->sc_hdrbuf, 2196fd5034dSChuck Lever ctxt->sc_xprt_buf, NULL); 2206fd5034dSChuck Lever 2214201c746SChuck Lever ctxt->sc_send_wr.num_sge = 0; 22299722fe4SChuck Lever ctxt->sc_cur_sge_no = 0; 2234201c746SChuck Lever ctxt->sc_page_count = 0; 2244201c746SChuck Lever return ctxt; 2254201c746SChuck Lever 2264201c746SChuck Lever out_empty: 2274201c746SChuck Lever spin_unlock(&rdma->sc_send_lock); 2284201c746SChuck Lever ctxt = svc_rdma_send_ctxt_alloc(rdma); 2294201c746SChuck Lever if (!ctxt) 2304201c746SChuck Lever return NULL; 2314201c746SChuck Lever goto out; 2324201c746SChuck Lever } 2334201c746SChuck Lever 2344201c746SChuck Lever /** 2354201c746SChuck Lever * svc_rdma_send_ctxt_put - Return send_ctxt to free list 2364201c746SChuck Lever * @rdma: controlling svcxprt_rdma 2374201c746SChuck Lever * @ctxt: object to return to the free list 2384201c746SChuck Lever * 2394201c746SChuck Lever * Pages left in sc_pages are DMA unmapped and released. 2404201c746SChuck Lever */ 2414201c746SChuck Lever void svc_rdma_send_ctxt_put(struct svcxprt_rdma *rdma, 2424201c746SChuck Lever struct svc_rdma_send_ctxt *ctxt) 2434201c746SChuck Lever { 2444201c746SChuck Lever struct ib_device *device = rdma->sc_cm_id->device; 2454201c746SChuck Lever unsigned int i; 2464201c746SChuck Lever 24799722fe4SChuck Lever /* The first SGE contains the transport header, which 24899722fe4SChuck Lever * remains mapped until @ctxt is destroyed. 24999722fe4SChuck Lever */ 250832b2cb9SChuck Lever for (i = 1; i < ctxt->sc_send_wr.num_sge; i++) { 2514201c746SChuck Lever ib_dma_unmap_page(device, 2524201c746SChuck Lever ctxt->sc_sges[i].addr, 2534201c746SChuck Lever ctxt->sc_sges[i].length, 2544201c746SChuck Lever DMA_TO_DEVICE); 255832b2cb9SChuck Lever trace_svcrdma_dma_unmap_page(rdma, 256832b2cb9SChuck Lever ctxt->sc_sges[i].addr, 257832b2cb9SChuck Lever ctxt->sc_sges[i].length); 258832b2cb9SChuck Lever } 2594201c746SChuck Lever 2604201c746SChuck Lever for (i = 0; i < ctxt->sc_page_count; ++i) 2614201c746SChuck Lever put_page(ctxt->sc_pages[i]); 2624201c746SChuck Lever 2634201c746SChuck Lever spin_lock(&rdma->sc_send_lock); 2644201c746SChuck Lever list_add(&ctxt->sc_list, &rdma->sc_send_ctxts); 2654201c746SChuck Lever spin_unlock(&rdma->sc_send_lock); 2664201c746SChuck Lever } 2674201c746SChuck Lever 2684201c746SChuck Lever /** 2694201c746SChuck Lever * svc_rdma_wc_send - Invoked by RDMA provider for each polled Send WC 2704201c746SChuck Lever * @cq: Completion Queue context 2714201c746SChuck Lever * @wc: Work Completion object 2724201c746SChuck Lever * 2734201c746SChuck Lever * NB: The svc_xprt/svcxprt_rdma is pinned whenever it's possible that 2744201c746SChuck Lever * the Send completion handler could be running. 2754201c746SChuck Lever */ 2764201c746SChuck Lever static void svc_rdma_wc_send(struct ib_cq *cq, struct ib_wc *wc) 2774201c746SChuck Lever { 2784201c746SChuck Lever struct svcxprt_rdma *rdma = cq->cq_context; 2794201c746SChuck Lever struct ib_cqe *cqe = wc->wr_cqe; 2803ac56c2fSChuck Lever struct svc_rdma_send_ctxt *ctxt = 2813ac56c2fSChuck Lever container_of(cqe, struct svc_rdma_send_ctxt, sc_cqe); 2824201c746SChuck Lever 2833ac56c2fSChuck Lever trace_svcrdma_wc_send(wc, &ctxt->sc_cid); 2844201c746SChuck Lever 2854201c746SChuck Lever atomic_inc(&rdma->sc_sq_avail); 2864201c746SChuck Lever wake_up(&rdma->sc_send_wait); 2874201c746SChuck Lever 2884201c746SChuck Lever svc_rdma_send_ctxt_put(rdma, ctxt); 2894201c746SChuck Lever 2904201c746SChuck Lever if (unlikely(wc->status != IB_WC_SUCCESS)) { 2914201c746SChuck Lever set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags); 2924201c746SChuck Lever svc_xprt_enqueue(&rdma->sc_xprt); 2934201c746SChuck Lever } 2944201c746SChuck Lever } 2954201c746SChuck Lever 2963abb03faSChuck Lever /** 2973abb03faSChuck Lever * svc_rdma_send - Post a single Send WR 2983abb03faSChuck Lever * @rdma: transport on which to post the WR 29917f70f8dSChuck Lever * @ctxt: send ctxt with a Send WR ready to post 3003abb03faSChuck Lever * 3013abb03faSChuck Lever * Returns zero the Send WR was posted successfully. Otherwise, a 3023abb03faSChuck Lever * negative errno is returned. 3033abb03faSChuck Lever */ 30417f70f8dSChuck Lever int svc_rdma_send(struct svcxprt_rdma *rdma, struct svc_rdma_send_ctxt *ctxt) 3054201c746SChuck Lever { 30617f70f8dSChuck Lever struct ib_send_wr *wr = &ctxt->sc_send_wr; 3074201c746SChuck Lever int ret; 3084201c746SChuck Lever 3093abb03faSChuck Lever might_sleep(); 3104201c746SChuck Lever 311aee4b74aSChuck Lever /* Sync the transport header buffer */ 312aee4b74aSChuck Lever ib_dma_sync_single_for_device(rdma->sc_pd->device, 313aee4b74aSChuck Lever wr->sg_list[0].addr, 314aee4b74aSChuck Lever wr->sg_list[0].length, 315aee4b74aSChuck Lever DMA_TO_DEVICE); 316aee4b74aSChuck Lever 3174201c746SChuck Lever /* If the SQ is full, wait until an SQ entry is available */ 3184201c746SChuck Lever while (1) { 3193abb03faSChuck Lever if ((atomic_dec_return(&rdma->sc_sq_avail) < 0)) { 3204201c746SChuck Lever atomic_inc(&rdma_stat_sq_starve); 3214201c746SChuck Lever trace_svcrdma_sq_full(rdma); 3223abb03faSChuck Lever atomic_inc(&rdma->sc_sq_avail); 3234201c746SChuck Lever wait_event(rdma->sc_send_wait, 3243abb03faSChuck Lever atomic_read(&rdma->sc_sq_avail) > 1); 3254201c746SChuck Lever if (test_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags)) 3264201c746SChuck Lever return -ENOTCONN; 3274201c746SChuck Lever trace_svcrdma_sq_retry(rdma); 3284201c746SChuck Lever continue; 3294201c746SChuck Lever } 3304201c746SChuck Lever 33117f70f8dSChuck Lever trace_svcrdma_post_send(ctxt); 332ed288d74SBart Van Assche ret = ib_post_send(rdma->sc_qp, wr, NULL); 333e28b4fc6SChuck Lever if (ret) 334e28b4fc6SChuck Lever break; 335e28b4fc6SChuck Lever return 0; 336e28b4fc6SChuck Lever } 337e28b4fc6SChuck Lever 338e28b4fc6SChuck Lever trace_svcrdma_sq_post_err(rdma, ret); 3394201c746SChuck Lever set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags); 3404201c746SChuck Lever wake_up(&rdma->sc_send_wait); 3414201c746SChuck Lever return ret; 3424201c746SChuck Lever } 3434201c746SChuck Lever 3446fd5034dSChuck Lever /** 3456fd5034dSChuck Lever * svc_rdma_encode_read_list - Encode RPC Reply's Read chunk list 3466fd5034dSChuck Lever * @sctxt: Send context for the RPC Reply 3479a6a180bSChuck Lever * 3486fd5034dSChuck Lever * Return values: 3496fd5034dSChuck Lever * On success, returns length in bytes of the Reply XDR buffer 3506fd5034dSChuck Lever * that was consumed by the Reply Read list 3516fd5034dSChuck Lever * %-EMSGSIZE on XDR buffer overflow 3529a6a180bSChuck Lever */ 3536fd5034dSChuck Lever static ssize_t svc_rdma_encode_read_list(struct svc_rdma_send_ctxt *sctxt) 3546fd5034dSChuck Lever { 3556fd5034dSChuck Lever /* RPC-over-RDMA version 1 replies never have a Read list. */ 3566fd5034dSChuck Lever return xdr_stream_encode_item_absent(&sctxt->sc_stream); 3576fd5034dSChuck Lever } 3586fd5034dSChuck Lever 3596fd5034dSChuck Lever /** 3606fd5034dSChuck Lever * svc_rdma_encode_write_segment - Encode one Write segment 3616fd5034dSChuck Lever * @src: matching Write chunk in the RPC Call header 3626fd5034dSChuck Lever * @sctxt: Send context for the RPC Reply 3636fd5034dSChuck Lever * @remaining: remaining bytes of the payload left in the Write chunk 3646fd5034dSChuck Lever * 3656fd5034dSChuck Lever * Return values: 3666fd5034dSChuck Lever * On success, returns length in bytes of the Reply XDR buffer 3676fd5034dSChuck Lever * that was consumed by the Write segment 3686fd5034dSChuck Lever * %-EMSGSIZE on XDR buffer overflow 3696fd5034dSChuck Lever */ 3706fd5034dSChuck Lever static ssize_t svc_rdma_encode_write_segment(__be32 *src, 3716fd5034dSChuck Lever struct svc_rdma_send_ctxt *sctxt, 3726fd5034dSChuck Lever unsigned int *remaining) 3736fd5034dSChuck Lever { 3746fd5034dSChuck Lever __be32 *p; 3756fd5034dSChuck Lever const size_t len = rpcrdma_segment_maxsz * sizeof(*p); 3766fd5034dSChuck Lever u32 handle, length; 3776fd5034dSChuck Lever u64 offset; 3786fd5034dSChuck Lever 3796fd5034dSChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, len); 3806fd5034dSChuck Lever if (!p) 3816fd5034dSChuck Lever return -EMSGSIZE; 3826fd5034dSChuck Lever 383f60a0869SChuck Lever xdr_decode_rdma_segment(src, &handle, &length, &offset); 3846fd5034dSChuck Lever 3856fd5034dSChuck Lever if (*remaining < length) { 3866fd5034dSChuck Lever /* segment only partly filled */ 3876fd5034dSChuck Lever length = *remaining; 3886fd5034dSChuck Lever *remaining = 0; 3896fd5034dSChuck Lever } else { 3906fd5034dSChuck Lever /* entire segment was consumed */ 3916fd5034dSChuck Lever *remaining -= length; 3926fd5034dSChuck Lever } 393379c3bc6SChuck Lever xdr_encode_rdma_segment(p, handle, length, offset); 3946fd5034dSChuck Lever 3956fd5034dSChuck Lever trace_svcrdma_encode_wseg(handle, length, offset); 3966fd5034dSChuck Lever return len; 3976fd5034dSChuck Lever } 3986fd5034dSChuck Lever 3996fd5034dSChuck Lever /** 4006fd5034dSChuck Lever * svc_rdma_encode_write_chunk - Encode one Write chunk 4016fd5034dSChuck Lever * @src: matching Write chunk in the RPC Call header 4026fd5034dSChuck Lever * @sctxt: Send context for the RPC Reply 4036fd5034dSChuck Lever * @remaining: size in bytes of the payload in the Write chunk 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 */ 4146fd5034dSChuck Lever static ssize_t svc_rdma_encode_write_chunk(__be32 *src, 4156fd5034dSChuck Lever struct svc_rdma_send_ctxt *sctxt, 4169a6a180bSChuck Lever unsigned int remaining) 4179a6a180bSChuck Lever { 4189a6a180bSChuck Lever unsigned int i, nsegs; 4196fd5034dSChuck Lever ssize_t len, ret; 4209a6a180bSChuck Lever 4216fd5034dSChuck Lever len = 0; 4226fd5034dSChuck Lever trace_svcrdma_encode_write_chunk(remaining); 4239a6a180bSChuck Lever 4246fd5034dSChuck Lever src++; 4256fd5034dSChuck Lever ret = xdr_stream_encode_item_present(&sctxt->sc_stream); 4266fd5034dSChuck Lever if (ret < 0) 4276fd5034dSChuck Lever return -EMSGSIZE; 4286fd5034dSChuck Lever len += ret; 4296fd5034dSChuck Lever 4306fd5034dSChuck Lever nsegs = be32_to_cpup(src++); 4316fd5034dSChuck Lever ret = xdr_stream_encode_u32(&sctxt->sc_stream, nsegs); 4326fd5034dSChuck Lever if (ret < 0) 4336fd5034dSChuck Lever return -EMSGSIZE; 4346fd5034dSChuck Lever len += ret; 4359a6a180bSChuck Lever 4369a6a180bSChuck Lever for (i = nsegs; i; i--) { 4376fd5034dSChuck Lever ret = svc_rdma_encode_write_segment(src, sctxt, &remaining); 4386fd5034dSChuck Lever if (ret < 0) 4396fd5034dSChuck Lever return -EMSGSIZE; 4406fd5034dSChuck Lever src += rpcrdma_segment_maxsz; 4416fd5034dSChuck Lever len += ret; 4429a6a180bSChuck Lever } 4439a6a180bSChuck Lever 4446fd5034dSChuck Lever return len; 4459a6a180bSChuck Lever } 4469a6a180bSChuck Lever 4476fd5034dSChuck Lever /** 4486fd5034dSChuck Lever * svc_rdma_encode_write_list - Encode RPC Reply's Write chunk list 4496fd5034dSChuck Lever * @rctxt: Reply context with information about the RPC Call 4506fd5034dSChuck Lever * @sctxt: Send context for the RPC Reply 4516fd5034dSChuck Lever * 4526fd5034dSChuck Lever * The client provides a Write chunk list in the Call message. Fill 4536fd5034dSChuck Lever * in the segments in the first Write chunk in the Reply's transport 4549a6a180bSChuck Lever * header with the number of bytes consumed in each segment. 4559a6a180bSChuck Lever * Remaining chunks are returned unused. 4569a6a180bSChuck Lever * 4579a6a180bSChuck Lever * Assumptions: 4589a6a180bSChuck Lever * - Client has provided only one Write chunk 4596fd5034dSChuck Lever * 4606fd5034dSChuck Lever * Return values: 4616fd5034dSChuck Lever * On success, returns length in bytes of the Reply XDR buffer 4626fd5034dSChuck Lever * that was consumed by the Reply's Write list 4636fd5034dSChuck Lever * %-EMSGSIZE on XDR buffer overflow 4649a6a180bSChuck Lever */ 4656fd5034dSChuck Lever static ssize_t 4666fd5034dSChuck Lever svc_rdma_encode_write_list(const struct svc_rdma_recv_ctxt *rctxt, 46776e5492bSChuck Lever struct svc_rdma_send_ctxt *sctxt) 4689a6a180bSChuck Lever { 4696fd5034dSChuck Lever ssize_t len, ret; 4709a6a180bSChuck Lever 471f6ad7759SChuck Lever len = 0; 472f6ad7759SChuck Lever if (rctxt->rc_write_list) { 47376e5492bSChuck Lever ret = svc_rdma_encode_write_chunk(rctxt->rc_write_list, sctxt, 47476e5492bSChuck Lever rctxt->rc_read_payload_length); 4756fd5034dSChuck Lever if (ret < 0) 4766fd5034dSChuck Lever return ret; 4776fd5034dSChuck Lever len = ret; 478f6ad7759SChuck Lever } 4799a6a180bSChuck Lever 4806fd5034dSChuck Lever /* Terminate the Write list */ 4816fd5034dSChuck Lever ret = xdr_stream_encode_item_absent(&sctxt->sc_stream); 4826fd5034dSChuck Lever if (ret < 0) 4836fd5034dSChuck Lever return ret; 4846fd5034dSChuck Lever 4856fd5034dSChuck Lever return len + ret; 4869a6a180bSChuck Lever } 4879a6a180bSChuck Lever 4886fd5034dSChuck Lever /** 4896fd5034dSChuck Lever * svc_rdma_encode_reply_chunk - Encode RPC Reply's Reply chunk 4906fd5034dSChuck Lever * @rctxt: Reply context with information about the RPC Call 4916fd5034dSChuck Lever * @sctxt: Send context for the RPC Reply 4926fd5034dSChuck Lever * @length: size in bytes of the payload in the Reply chunk 4939a6a180bSChuck Lever * 4949a6a180bSChuck Lever * Assumptions: 4956fd5034dSChuck Lever * - Reply can always fit in the client-provided Reply chunk 4966fd5034dSChuck Lever * 4976fd5034dSChuck Lever * Return values: 4986fd5034dSChuck Lever * On success, returns length in bytes of the Reply XDR buffer 4996fd5034dSChuck Lever * that was consumed by the Reply's Reply chunk 5006fd5034dSChuck Lever * %-EMSGSIZE on XDR buffer overflow 5019a6a180bSChuck Lever */ 5026fd5034dSChuck Lever static ssize_t 5036fd5034dSChuck Lever svc_rdma_encode_reply_chunk(const struct svc_rdma_recv_ctxt *rctxt, 5046fd5034dSChuck Lever struct svc_rdma_send_ctxt *sctxt, 5056fd5034dSChuck Lever unsigned int length) 5069a6a180bSChuck Lever { 507*ded380f1SChuck Lever if (!rctxt->rc_reply_chunk) 508*ded380f1SChuck Lever return xdr_stream_encode_item_absent(&sctxt->sc_stream); 509*ded380f1SChuck Lever 5106fd5034dSChuck Lever return svc_rdma_encode_write_chunk(rctxt->rc_reply_chunk, sctxt, 5116fd5034dSChuck Lever length); 5129a6a180bSChuck Lever } 5139a6a180bSChuck Lever 5146e6092caSChuck Lever static int svc_rdma_dma_map_page(struct svcxprt_rdma *rdma, 5154201c746SChuck Lever struct svc_rdma_send_ctxt *ctxt, 5166e6092caSChuck Lever struct page *page, 517f016f305SChuck Lever unsigned long offset, 5186e6092caSChuck Lever unsigned int len) 5196e6092caSChuck Lever { 5206e6092caSChuck Lever struct ib_device *dev = rdma->sc_cm_id->device; 5216e6092caSChuck Lever dma_addr_t dma_addr; 5226e6092caSChuck Lever 5236e6092caSChuck Lever dma_addr = ib_dma_map_page(dev, page, offset, len, DMA_TO_DEVICE); 524832b2cb9SChuck Lever trace_svcrdma_dma_map_page(rdma, dma_addr, len); 5256e6092caSChuck Lever if (ib_dma_mapping_error(dev, dma_addr)) 52691a08eaeSChuck Lever goto out_maperr; 5276e6092caSChuck Lever 52825fd86ecSChuck Lever ctxt->sc_sges[ctxt->sc_cur_sge_no].addr = dma_addr; 52925fd86ecSChuck Lever ctxt->sc_sges[ctxt->sc_cur_sge_no].length = len; 5304201c746SChuck Lever ctxt->sc_send_wr.num_sge++; 5316e6092caSChuck Lever return 0; 53291a08eaeSChuck Lever 53391a08eaeSChuck Lever out_maperr: 53491a08eaeSChuck Lever return -EIO; 5356e6092caSChuck Lever } 5366e6092caSChuck Lever 537f016f305SChuck Lever /* ib_dma_map_page() is used here because svc_rdma_dma_unmap() 538f016f305SChuck Lever * handles DMA-unmap and it uses ib_dma_unmap_page() exclusively. 539f016f305SChuck Lever */ 540f016f305SChuck Lever static int svc_rdma_dma_map_buf(struct svcxprt_rdma *rdma, 5414201c746SChuck Lever struct svc_rdma_send_ctxt *ctxt, 542f016f305SChuck Lever unsigned char *base, 543f016f305SChuck Lever unsigned int len) 544f016f305SChuck Lever { 54525fd86ecSChuck Lever return svc_rdma_dma_map_page(rdma, ctxt, virt_to_page(base), 546f016f305SChuck Lever offset_in_page(base), len); 547f016f305SChuck Lever } 548f016f305SChuck Lever 5496e6092caSChuck Lever /** 5504554755eSChuck Lever * svc_rdma_pull_up_needed - Determine whether to use pull-up 5514554755eSChuck Lever * @rdma: controlling transport 5520dabe948SChuck Lever * @sctxt: send_ctxt for the Send WR 5534554755eSChuck Lever * @rctxt: Write and Reply chunks provided by client 5544554755eSChuck Lever * @xdr: xdr_buf containing RPC message to transmit 5554554755eSChuck Lever * 5564554755eSChuck Lever * Returns: 5574554755eSChuck Lever * %true if pull-up must be used 5584554755eSChuck Lever * %false otherwise 559e248aa7bSChuck Lever */ 560e248aa7bSChuck Lever static bool svc_rdma_pull_up_needed(struct svcxprt_rdma *rdma, 5610dabe948SChuck Lever struct svc_rdma_send_ctxt *sctxt, 5624554755eSChuck Lever const struct svc_rdma_recv_ctxt *rctxt, 5634554755eSChuck Lever struct xdr_buf *xdr) 564e248aa7bSChuck Lever { 565f6ad7759SChuck Lever bool write_chunk_present = rctxt && rctxt->rc_write_list; 566e248aa7bSChuck Lever int elements; 567e248aa7bSChuck Lever 5680dabe948SChuck Lever /* For small messages, copying bytes is cheaper than DMA mapping. 5690dabe948SChuck Lever */ 570f6ad7759SChuck Lever if (!write_chunk_present && 571f6ad7759SChuck Lever sctxt->sc_hdrbuf.len + xdr->len < RPCRDMA_PULLUP_THRESH) 5720dabe948SChuck Lever return true; 5730dabe948SChuck Lever 5740dabe948SChuck Lever /* Check whether the xdr_buf has more elements than can 5750dabe948SChuck Lever * fit in a single RDMA Send. 5760dabe948SChuck Lever */ 577e248aa7bSChuck Lever /* xdr->head */ 578e248aa7bSChuck Lever elements = 1; 579e248aa7bSChuck Lever 580e248aa7bSChuck Lever /* xdr->pages */ 5814554755eSChuck Lever if (!rctxt || !rctxt->rc_write_list) { 582e248aa7bSChuck Lever unsigned int remaining; 583e248aa7bSChuck Lever unsigned long pageoff; 584e248aa7bSChuck Lever 585e248aa7bSChuck Lever pageoff = xdr->page_base & ~PAGE_MASK; 586e248aa7bSChuck Lever remaining = xdr->page_len; 587e248aa7bSChuck Lever while (remaining) { 588e248aa7bSChuck Lever ++elements; 589e248aa7bSChuck Lever remaining -= min_t(u32, PAGE_SIZE - pageoff, 590e248aa7bSChuck Lever remaining); 591e248aa7bSChuck Lever pageoff = 0; 592e248aa7bSChuck Lever } 593e248aa7bSChuck Lever } 594e248aa7bSChuck Lever 595e248aa7bSChuck Lever /* xdr->tail */ 596e248aa7bSChuck Lever if (xdr->tail[0].iov_len) 597e248aa7bSChuck Lever ++elements; 598e248aa7bSChuck Lever 599e248aa7bSChuck Lever /* assume 1 SGE is needed for the transport header */ 600e248aa7bSChuck Lever return elements >= rdma->sc_max_send_sges; 601e248aa7bSChuck Lever } 602e248aa7bSChuck Lever 6034554755eSChuck Lever /** 6044554755eSChuck Lever * svc_rdma_pull_up_reply_msg - Copy Reply into a single buffer 6054554755eSChuck Lever * @rdma: controlling transport 6064554755eSChuck Lever * @sctxt: send_ctxt for the Send WR; xprt hdr is already prepared 6074554755eSChuck Lever * @rctxt: Write and Reply chunks provided by client 6084554755eSChuck Lever * @xdr: prepared xdr_buf containing RPC message 6094554755eSChuck Lever * 6104554755eSChuck Lever * The device is not capable of sending the reply directly. 6114554755eSChuck Lever * Assemble the elements of @xdr into the transport header buffer. 6124554755eSChuck Lever * 6134554755eSChuck Lever * Returns zero on success, or a negative errno on failure. 614e248aa7bSChuck Lever */ 615e248aa7bSChuck Lever static int svc_rdma_pull_up_reply_msg(struct svcxprt_rdma *rdma, 6164554755eSChuck Lever struct svc_rdma_send_ctxt *sctxt, 6174554755eSChuck Lever const struct svc_rdma_recv_ctxt *rctxt, 6184554755eSChuck Lever const struct xdr_buf *xdr) 619e248aa7bSChuck Lever { 620e248aa7bSChuck Lever unsigned char *dst, *tailbase; 621e248aa7bSChuck Lever unsigned int taillen; 622e248aa7bSChuck Lever 623aee4b74aSChuck Lever dst = sctxt->sc_xprt_buf + sctxt->sc_hdrbuf.len; 624e248aa7bSChuck Lever memcpy(dst, xdr->head[0].iov_base, xdr->head[0].iov_len); 625e248aa7bSChuck Lever dst += xdr->head[0].iov_len; 626e248aa7bSChuck Lever 627e248aa7bSChuck Lever tailbase = xdr->tail[0].iov_base; 628e248aa7bSChuck Lever taillen = xdr->tail[0].iov_len; 6294554755eSChuck Lever if (rctxt && rctxt->rc_write_list) { 630e248aa7bSChuck Lever u32 xdrpad; 631e248aa7bSChuck Lever 63296f194b7SChuck Lever xdrpad = xdr_pad_size(xdr->page_len); 633e248aa7bSChuck Lever if (taillen && xdrpad) { 634e248aa7bSChuck Lever tailbase += xdrpad; 635e248aa7bSChuck Lever taillen -= xdrpad; 636e248aa7bSChuck Lever } 637e248aa7bSChuck Lever } else { 638e248aa7bSChuck Lever unsigned int len, remaining; 639e248aa7bSChuck Lever unsigned long pageoff; 640e248aa7bSChuck Lever struct page **ppages; 641e248aa7bSChuck Lever 642e248aa7bSChuck Lever ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT); 643e248aa7bSChuck Lever pageoff = xdr->page_base & ~PAGE_MASK; 644e248aa7bSChuck Lever remaining = xdr->page_len; 645e248aa7bSChuck Lever while (remaining) { 646e248aa7bSChuck Lever len = min_t(u32, PAGE_SIZE - pageoff, remaining); 647e248aa7bSChuck Lever 648c327a310SDan Aloni memcpy(dst, page_address(*ppages) + pageoff, len); 649e248aa7bSChuck Lever remaining -= len; 650e248aa7bSChuck Lever dst += len; 651e248aa7bSChuck Lever pageoff = 0; 652c327a310SDan Aloni ppages++; 653e248aa7bSChuck Lever } 654e248aa7bSChuck Lever } 655e248aa7bSChuck Lever 656e248aa7bSChuck Lever if (taillen) 657e248aa7bSChuck Lever memcpy(dst, tailbase, taillen); 658e248aa7bSChuck Lever 6594554755eSChuck Lever sctxt->sc_sges[0].length += xdr->len; 6600dabe948SChuck Lever trace_svcrdma_send_pullup(sctxt->sc_sges[0].length); 661e248aa7bSChuck Lever return 0; 662e248aa7bSChuck Lever } 663e248aa7bSChuck Lever 6644554755eSChuck Lever /* svc_rdma_map_reply_msg - DMA map the buffer holding RPC message 66599722fe4SChuck Lever * @rdma: controlling transport 6664554755eSChuck Lever * @sctxt: send_ctxt for the Send WR 6674554755eSChuck Lever * @rctxt: Write and Reply chunks provided by client 66899722fe4SChuck Lever * @xdr: prepared xdr_buf containing RPC message 66999722fe4SChuck Lever * 67099722fe4SChuck Lever * Load the xdr_buf into the ctxt's sge array, and DMA map each 671aee4b74aSChuck Lever * element as it is added. The Send WR's num_sge field is set. 6729a6a180bSChuck Lever * 67323262790SChuck Lever * Returns zero on success, or a negative errno on failure. 674c06b540aSTom Tucker */ 67599722fe4SChuck Lever int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma, 6764554755eSChuck Lever struct svc_rdma_send_ctxt *sctxt, 6774554755eSChuck Lever const struct svc_rdma_recv_ctxt *rctxt, 6784554755eSChuck Lever struct xdr_buf *xdr) 679c06b540aSTom Tucker { 68025fd86ecSChuck Lever unsigned int len, remaining; 681f016f305SChuck Lever unsigned long page_off; 6829a6a180bSChuck Lever struct page **ppages; 6839a6a180bSChuck Lever unsigned char *base; 6849a6a180bSChuck Lever u32 xdr_pad; 685c06b540aSTom Tucker int ret; 686c06b540aSTom Tucker 687aee4b74aSChuck Lever /* Set up the (persistently-mapped) transport header SGE. */ 688aee4b74aSChuck Lever sctxt->sc_send_wr.num_sge = 1; 689aee4b74aSChuck Lever sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len; 690aee4b74aSChuck Lever 691aee4b74aSChuck Lever /* If there is a Reply chunk, nothing follows the transport 692aee4b74aSChuck Lever * header, and we're done here. 693aee4b74aSChuck Lever */ 694aee4b74aSChuck Lever if (rctxt && rctxt->rc_reply_chunk) 695aee4b74aSChuck Lever return 0; 696aee4b74aSChuck Lever 697aee4b74aSChuck Lever /* For pull-up, svc_rdma_send() will sync the transport header. 698aee4b74aSChuck Lever * No additional DMA mapping is necessary. 699aee4b74aSChuck Lever */ 7000dabe948SChuck Lever if (svc_rdma_pull_up_needed(rdma, sctxt, rctxt, xdr)) 7014554755eSChuck Lever return svc_rdma_pull_up_reply_msg(rdma, sctxt, rctxt, xdr); 702e248aa7bSChuck Lever 7034554755eSChuck Lever ++sctxt->sc_cur_sge_no; 7044554755eSChuck Lever ret = svc_rdma_dma_map_buf(rdma, sctxt, 7059a6a180bSChuck Lever xdr->head[0].iov_base, 7069a6a180bSChuck Lever xdr->head[0].iov_len); 7079a6a180bSChuck Lever if (ret < 0) 7089a6a180bSChuck Lever return ret; 709c06b540aSTom Tucker 7109a6a180bSChuck Lever /* If a Write chunk is present, the xdr_buf's page list 7119a6a180bSChuck Lever * is not included inline. However the Upper Layer may 7129a6a180bSChuck Lever * have added XDR padding in the tail buffer, and that 7139a6a180bSChuck Lever * should not be included inline. 7149a6a180bSChuck Lever */ 7154554755eSChuck Lever if (rctxt && rctxt->rc_write_list) { 7169a6a180bSChuck Lever base = xdr->tail[0].iov_base; 7179a6a180bSChuck Lever len = xdr->tail[0].iov_len; 71896f194b7SChuck Lever xdr_pad = xdr_pad_size(xdr->page_len); 719c06b540aSTom Tucker 7209a6a180bSChuck Lever if (len && xdr_pad) { 7219a6a180bSChuck Lever base += xdr_pad; 7229a6a180bSChuck Lever len -= xdr_pad; 723c06b540aSTom Tucker } 724c06b540aSTom Tucker 7259a6a180bSChuck Lever goto tail; 726c06b540aSTom Tucker } 7279a6a180bSChuck Lever 7289a6a180bSChuck Lever ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT); 7299a6a180bSChuck Lever page_off = xdr->page_base & ~PAGE_MASK; 7309a6a180bSChuck Lever remaining = xdr->page_len; 7319a6a180bSChuck Lever while (remaining) { 7329a6a180bSChuck Lever len = min_t(u32, PAGE_SIZE - page_off, remaining); 7339a6a180bSChuck Lever 7344554755eSChuck Lever ++sctxt->sc_cur_sge_no; 7354554755eSChuck Lever ret = svc_rdma_dma_map_page(rdma, sctxt, *ppages++, 73625fd86ecSChuck Lever page_off, len); 7379a6a180bSChuck Lever if (ret < 0) 7389a6a180bSChuck Lever return ret; 7399a6a180bSChuck Lever 7409a6a180bSChuck Lever remaining -= len; 7419a6a180bSChuck Lever page_off = 0; 742c06b540aSTom Tucker } 743c06b540aSTom Tucker 7449a6a180bSChuck Lever base = xdr->tail[0].iov_base; 7459a6a180bSChuck Lever len = xdr->tail[0].iov_len; 7469a6a180bSChuck Lever tail: 7479a6a180bSChuck Lever if (len) { 7484554755eSChuck Lever ++sctxt->sc_cur_sge_no; 7494554755eSChuck Lever ret = svc_rdma_dma_map_buf(rdma, sctxt, base, len); 7509a6a180bSChuck Lever if (ret < 0) 7519a6a180bSChuck Lever return ret; 7529a6a180bSChuck Lever } 75308ae4e7fSChuck Lever 75423262790SChuck Lever return 0; 755c06b540aSTom Tucker } 756c06b540aSTom Tucker 757c55ab070SChuck Lever /* The svc_rqst and all resources it owns are released as soon as 758c55ab070SChuck Lever * svc_rdma_sendto returns. Transfer pages under I/O to the ctxt 759c55ab070SChuck Lever * so they are released by the Send completion handler. 760c55ab070SChuck Lever */ 761c55ab070SChuck Lever static void svc_rdma_save_io_pages(struct svc_rqst *rqstp, 7624201c746SChuck Lever struct svc_rdma_send_ctxt *ctxt) 763c55ab070SChuck Lever { 764c55ab070SChuck Lever int i, pages = rqstp->rq_next_page - rqstp->rq_respages; 765c55ab070SChuck Lever 7664201c746SChuck Lever ctxt->sc_page_count += pages; 767c55ab070SChuck Lever for (i = 0; i < pages; i++) { 76899722fe4SChuck Lever ctxt->sc_pages[i] = rqstp->rq_respages[i]; 769c55ab070SChuck Lever rqstp->rq_respages[i] = NULL; 770c55ab070SChuck Lever } 771a53d5cb0SChuck Lever 772a53d5cb0SChuck Lever /* Prevent svc_xprt_release from releasing pages in rq_pages */ 773a53d5cb0SChuck Lever rqstp->rq_next_page = rqstp->rq_respages; 774c55ab070SChuck Lever } 775c55ab070SChuck Lever 7769a6a180bSChuck Lever /* Prepare the portion of the RPC Reply that will be transmitted 7779a6a180bSChuck Lever * via RDMA Send. The RPC-over-RDMA transport header is prepared 7784201c746SChuck Lever * in sc_sges[0], and the RPC xdr_buf is prepared in following sges. 7799a6a180bSChuck Lever * 7809a6a180bSChuck Lever * Depending on whether a Write list or Reply chunk is present, 7819a6a180bSChuck Lever * the server may send all, a portion of, or none of the xdr_buf. 7824201c746SChuck Lever * In the latter case, only the transport header (sc_sges[0]) is 7839a6a180bSChuck Lever * transmitted. 7849a6a180bSChuck Lever * 7859a6a180bSChuck Lever * RDMA Send is the last step of transmitting an RPC reply. Pages 7869a6a180bSChuck Lever * involved in the earlier RDMA Writes are here transferred out 78797bce634SChuck Lever * of the rqstp and into the sctxt's page array. These pages are 7889a6a180bSChuck Lever * DMA unmapped by each Write completion, but the subsequent Send 7899a6a180bSChuck Lever * completion finally releases these pages. 7909a6a180bSChuck Lever * 7919a6a180bSChuck Lever * Assumptions: 7929a6a180bSChuck Lever * - The Reply's transport header will never be larger than a page. 793c06b540aSTom Tucker */ 7949a6a180bSChuck Lever static int svc_rdma_send_reply_msg(struct svcxprt_rdma *rdma, 79597bce634SChuck Lever struct svc_rdma_send_ctxt *sctxt, 796db9602e4SChuck Lever const struct svc_rdma_recv_ctxt *rctxt, 797db9602e4SChuck Lever struct svc_rqst *rqstp) 798c06b540aSTom Tucker { 7999a6a180bSChuck Lever int ret; 8000e7f011aSTom Tucker 801aee4b74aSChuck Lever ret = svc_rdma_map_reply_msg(rdma, sctxt, rctxt, &rqstp->rq_res); 8029a6a180bSChuck Lever if (ret < 0) 80399722fe4SChuck Lever return ret; 804c06b540aSTom Tucker 80597bce634SChuck Lever svc_rdma_save_io_pages(rqstp, sctxt); 8060bf48289SSteve Wise 80797bce634SChuck Lever if (rctxt->rc_inv_rkey) { 80897bce634SChuck Lever sctxt->sc_send_wr.opcode = IB_WR_SEND_WITH_INV; 80997bce634SChuck Lever sctxt->sc_send_wr.ex.invalidate_rkey = rctxt->rc_inv_rkey; 81097bce634SChuck Lever } else { 81197bce634SChuck Lever sctxt->sc_send_wr.opcode = IB_WR_SEND; 812986b7889SChuck Lever } 81317f70f8dSChuck Lever return svc_rdma_send(rdma, sctxt); 814c06b540aSTom Tucker } 815c06b540aSTom Tucker 816c65b326bSChuck Lever /** 817c65b326bSChuck Lever * svc_rdma_send_error_msg - Send an RPC/RDMA v1 error response 818c65b326bSChuck Lever * @rdma: controlling transport context 819c65b326bSChuck Lever * @sctxt: Send context for the response 820c65b326bSChuck Lever * @rctxt: Receive context for incoming bad message 821c65b326bSChuck Lever * @status: negative errno indicating error that occurred 8224757d90bSChuck Lever * 823c65b326bSChuck Lever * Given the client-provided Read, Write, and Reply chunks, the 824c65b326bSChuck Lever * server was not able to parse the Call or form a complete Reply. 825c65b326bSChuck Lever * Return an RDMA_ERROR message so the client can retire the RPC 826c65b326bSChuck Lever * transaction. 827c65b326bSChuck Lever * 828c65b326bSChuck Lever * The caller does not have to release @sctxt. It is released by 829c65b326bSChuck Lever * Send completion, or by this function on error. 8304757d90bSChuck Lever */ 831c65b326bSChuck Lever void svc_rdma_send_error_msg(struct svcxprt_rdma *rdma, 832d1f6e236SChuck Lever struct svc_rdma_send_ctxt *sctxt, 8334f200bd8SChuck Lever struct svc_rdma_recv_ctxt *rctxt, 8344f200bd8SChuck Lever int status) 8354757d90bSChuck Lever { 8366fd5034dSChuck Lever __be32 *rdma_argp = rctxt->rc_recv_buf; 8374757d90bSChuck Lever __be32 *p; 8384757d90bSChuck Lever 839d1f6e236SChuck Lever rpcrdma_set_xdrlen(&sctxt->sc_hdrbuf, 0); 840d1f6e236SChuck Lever xdr_init_encode(&sctxt->sc_stream, &sctxt->sc_hdrbuf, 841d1f6e236SChuck Lever sctxt->sc_xprt_buf, NULL); 8426fd5034dSChuck Lever 8434f200bd8SChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, 8444f200bd8SChuck Lever rpcrdma_fixed_maxsz * sizeof(*p)); 8456fd5034dSChuck Lever if (!p) 846605c61beSChuck Lever goto put_ctxt; 8476fd5034dSChuck Lever 8486fd5034dSChuck Lever *p++ = *rdma_argp; 8496fd5034dSChuck Lever *p++ = *(rdma_argp + 1); 8506fd5034dSChuck Lever *p++ = rdma->sc_fc_credits; 8514f200bd8SChuck Lever *p = rdma_error; 8524f200bd8SChuck Lever 8534f200bd8SChuck Lever switch (status) { 8544f200bd8SChuck Lever case -EPROTONOSUPPORT: 8554f200bd8SChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, 3 * sizeof(*p)); 8564f200bd8SChuck Lever if (!p) 857605c61beSChuck Lever goto put_ctxt; 8584f200bd8SChuck Lever 8594f200bd8SChuck Lever *p++ = err_vers; 8604f200bd8SChuck Lever *p++ = rpcrdma_version; 8614f200bd8SChuck Lever *p = rpcrdma_version; 8624f200bd8SChuck Lever trace_svcrdma_err_vers(*rdma_argp); 8634f200bd8SChuck Lever break; 8644f200bd8SChuck Lever default: 8654f200bd8SChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, sizeof(*p)); 8664f200bd8SChuck Lever if (!p) 867605c61beSChuck Lever goto put_ctxt; 8684f200bd8SChuck Lever 8694757d90bSChuck Lever *p = err_chunk; 8706fd5034dSChuck Lever trace_svcrdma_err_chunk(*rdma_argp); 8714f200bd8SChuck Lever } 8726fd5034dSChuck Lever 873c65b326bSChuck Lever /* Remote Invalidation is skipped for simplicity. */ 874d1f6e236SChuck Lever sctxt->sc_send_wr.num_sge = 1; 875d1f6e236SChuck Lever sctxt->sc_send_wr.opcode = IB_WR_SEND; 876d1f6e236SChuck Lever sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len; 87717f70f8dSChuck Lever if (svc_rdma_send(rdma, sctxt)) 878605c61beSChuck Lever goto put_ctxt; 879605c61beSChuck Lever return; 880605c61beSChuck Lever 881605c61beSChuck Lever put_ctxt: 882605c61beSChuck Lever svc_rdma_send_ctxt_put(rdma, sctxt); 88399722fe4SChuck Lever } 88499722fe4SChuck Lever 8859a6a180bSChuck Lever /** 8869a6a180bSChuck Lever * svc_rdma_sendto - Transmit an RPC reply 8879a6a180bSChuck Lever * @rqstp: processed RPC request, reply XDR already in ::rq_res 8889a6a180bSChuck Lever * 8899a6a180bSChuck Lever * Any resources still associated with @rqstp are released upon return. 8909a6a180bSChuck Lever * If no reply message was possible, the connection is closed. 8919a6a180bSChuck Lever * 8929a6a180bSChuck Lever * Returns: 8939a6a180bSChuck Lever * %0 if an RPC reply has been successfully posted, 8949a6a180bSChuck Lever * %-ENOMEM if a resource shortage occurred (connection is lost), 8959a6a180bSChuck Lever * %-ENOTCONN if posting failed (connection is lost). 8969a6a180bSChuck Lever */ 897c06b540aSTom Tucker int svc_rdma_sendto(struct svc_rqst *rqstp) 898c06b540aSTom Tucker { 899c06b540aSTom Tucker struct svc_xprt *xprt = rqstp->rq_xprt; 900c06b540aSTom Tucker struct svcxprt_rdma *rdma = 901c06b540aSTom Tucker container_of(xprt, struct svcxprt_rdma, sc_xprt); 9023a88092eSChuck Lever struct svc_rdma_recv_ctxt *rctxt = rqstp->rq_xprt_ctxt; 9032fe8c446SChuck Lever __be32 *rdma_argp = rctxt->rc_recv_buf; 90499722fe4SChuck Lever struct svc_rdma_send_ctxt *sctxt; 9056fd5034dSChuck Lever __be32 *p; 9069a6a180bSChuck Lever int ret; 907c06b540aSTom Tucker 908ca4faf54SChuck Lever ret = -ENOTCONN; 909ca4faf54SChuck Lever if (svc_xprt_is_dead(xprt)) 910ca4faf54SChuck Lever goto err0; 911ca4faf54SChuck Lever 91278da2b3cSChuck Lever ret = -ENOMEM; 91399722fe4SChuck Lever sctxt = svc_rdma_send_ctxt_get(rdma); 91499722fe4SChuck Lever if (!sctxt) 91578da2b3cSChuck Lever goto err0; 91698fc21d3SChuck Lever 9176fd5034dSChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, 9186fd5034dSChuck Lever rpcrdma_fixed_maxsz * sizeof(*p)); 9196fd5034dSChuck Lever if (!p) 9206fd5034dSChuck Lever goto err0; 921*ded380f1SChuck Lever 922*ded380f1SChuck Lever ret = svc_rdma_send_reply_chunk(rdma, rctxt, &rqstp->rq_res); 923*ded380f1SChuck Lever if (ret < 0) 924*ded380f1SChuck Lever goto err2; 925*ded380f1SChuck Lever 9269a6a180bSChuck Lever *p++ = *rdma_argp; 9279a6a180bSChuck Lever *p++ = *(rdma_argp + 1); 92898fc21d3SChuck Lever *p++ = rdma->sc_fc_credits; 929*ded380f1SChuck Lever *p = rctxt->rc_reply_chunk ? rdma_nomsg : rdma_msg; 93098fc21d3SChuck Lever 9316fd5034dSChuck Lever if (svc_rdma_encode_read_list(sctxt) < 0) 9326fd5034dSChuck Lever goto err0; 93376e5492bSChuck Lever if (svc_rdma_encode_write_list(rctxt, sctxt) < 0) 9346fd5034dSChuck Lever goto err0; 9356fd5034dSChuck Lever if (svc_rdma_encode_reply_chunk(rctxt, sctxt, ret) < 0) 9366fd5034dSChuck Lever goto err0; 937c06b540aSTom Tucker 938db9602e4SChuck Lever ret = svc_rdma_send_reply_msg(rdma, sctxt, rctxt, rqstp); 9393e1eeb98SChuck Lever if (ret < 0) 94099722fe4SChuck Lever goto err1; 94123cf1ee1SChuck Lever return 0; 942afd566eaSTom Tucker 9434757d90bSChuck Lever err2: 944b20dae70SColin Ian King if (ret != -E2BIG && ret != -EINVAL) 9454757d90bSChuck Lever goto err1; 9464757d90bSChuck Lever 9476e9fab70SChuck Lever /* Send completion releases payload pages that were part 9486e9fab70SChuck Lever * of previously posted RDMA Writes. 9496e9fab70SChuck Lever */ 9506e9fab70SChuck Lever svc_rdma_save_io_pages(rqstp, sctxt); 951605c61beSChuck Lever svc_rdma_send_error_msg(rdma, sctxt, rctxt, ret); 95223cf1ee1SChuck Lever return 0; 9534757d90bSChuck Lever 954afd566eaSTom Tucker err1: 95599722fe4SChuck Lever svc_rdma_send_ctxt_put(rdma, sctxt); 956afd566eaSTom Tucker err0: 9573f8f25c6SChuck Lever trace_svcrdma_send_err(rqstp, ret); 9589a6a180bSChuck Lever set_bit(XPT_CLOSE, &xprt->xpt_flags); 95923cf1ee1SChuck Lever return -ENOTCONN; 960c06b540aSTom Tucker } 96141205539SChuck Lever 96241205539SChuck Lever /** 96303493bcaSChuck Lever * svc_rdma_result_payload - special processing for a result payload 96441205539SChuck Lever * @rqstp: svc_rqst to operate on 96541205539SChuck Lever * @offset: payload's byte offset in @xdr 96641205539SChuck Lever * @length: size of payload, in bytes 96741205539SChuck Lever * 968f6ad7759SChuck Lever * Return values: 969f6ad7759SChuck Lever * %0 if successful or nothing needed to be done 970f6ad7759SChuck Lever * %-EMSGSIZE on XDR buffer overflow 971f6ad7759SChuck Lever * %-E2BIG if the payload was larger than the Write chunk 972f6ad7759SChuck Lever * %-EINVAL if client provided too many segments 973f6ad7759SChuck Lever * %-ENOMEM if rdma_rw context pool was exhausted 974f6ad7759SChuck Lever * %-ENOTCONN if posting failed (connection is lost) 975f6ad7759SChuck Lever * %-EIO if rdma_rw initialization failed (DMA mapping, etc) 97641205539SChuck Lever */ 97703493bcaSChuck Lever int svc_rdma_result_payload(struct svc_rqst *rqstp, unsigned int offset, 97841205539SChuck Lever unsigned int length) 97941205539SChuck Lever { 98041205539SChuck Lever struct svc_rdma_recv_ctxt *rctxt = rqstp->rq_xprt_ctxt; 981f6ad7759SChuck Lever struct svcxprt_rdma *rdma; 982f6ad7759SChuck Lever struct xdr_buf subbuf; 983f6ad7759SChuck Lever int ret; 984f6ad7759SChuck Lever 985f6ad7759SChuck Lever if (!rctxt->rc_write_list || !length) 986f6ad7759SChuck Lever return 0; 98741205539SChuck Lever 98841205539SChuck Lever /* XXX: Just one READ payload slot for now, since our 98941205539SChuck Lever * transport implementation currently supports only one 99041205539SChuck Lever * Write chunk. 99141205539SChuck Lever */ 99241205539SChuck Lever rctxt->rc_read_payload_offset = offset; 99341205539SChuck Lever rctxt->rc_read_payload_length = length; 99441205539SChuck Lever 995f6ad7759SChuck Lever if (xdr_buf_subsegment(&rqstp->rq_res, &subbuf, offset, length)) 996f6ad7759SChuck Lever return -EMSGSIZE; 997f6ad7759SChuck Lever 998f6ad7759SChuck Lever rdma = container_of(rqstp->rq_xprt, struct svcxprt_rdma, sc_xprt); 999f6ad7759SChuck Lever ret = svc_rdma_send_write_chunk(rdma, rctxt->rc_write_list, &subbuf); 1000f6ad7759SChuck Lever if (ret < 0) 1001f6ad7759SChuck Lever return ret; 100241205539SChuck Lever return 0; 100341205539SChuck Lever } 1004