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 * @sctxt: Send context for the RPC Reply 3626911f3e1SChuck Lever * @chunk: Write chunk to push 3636fd5034dSChuck Lever * @remaining: remaining bytes of the payload left in the Write chunk 3646911f3e1SChuck Lever * @segno: which segment in the chunk 3656fd5034dSChuck Lever * 3666fd5034dSChuck Lever * Return values: 3676fd5034dSChuck Lever * On success, returns length in bytes of the Reply XDR buffer 3686911f3e1SChuck Lever * that was consumed by the Write segment, and updates @remaining 3696fd5034dSChuck Lever * %-EMSGSIZE on XDR buffer overflow 3706fd5034dSChuck Lever */ 3716911f3e1SChuck Lever static ssize_t svc_rdma_encode_write_segment(struct svc_rdma_send_ctxt *sctxt, 3726911f3e1SChuck Lever const struct svc_rdma_chunk *chunk, 3736911f3e1SChuck Lever u32 *remaining, unsigned int segno) 3746fd5034dSChuck Lever { 3756911f3e1SChuck Lever const struct svc_rdma_segment *segment = &chunk->ch_segments[segno]; 3766911f3e1SChuck Lever const size_t len = rpcrdma_segment_maxsz * sizeof(__be32); 3776911f3e1SChuck Lever u32 length; 3786fd5034dSChuck Lever __be32 *p; 3796fd5034dSChuck Lever 3806fd5034dSChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, len); 3816fd5034dSChuck Lever if (!p) 3826fd5034dSChuck Lever return -EMSGSIZE; 3836fd5034dSChuck Lever 3846911f3e1SChuck Lever length = min_t(u32, *remaining, segment->rs_length); 3856fd5034dSChuck Lever *remaining -= length; 3866911f3e1SChuck Lever xdr_encode_rdma_segment(p, segment->rs_handle, length, 3876911f3e1SChuck Lever segment->rs_offset); 3886911f3e1SChuck Lever trace_svcrdma_encode_wseg(sctxt, segno, segment->rs_handle, length, 3896911f3e1SChuck Lever segment->rs_offset); 3906fd5034dSChuck Lever return len; 3916fd5034dSChuck Lever } 3926fd5034dSChuck Lever 3936fd5034dSChuck Lever /** 3946fd5034dSChuck Lever * svc_rdma_encode_write_chunk - Encode one Write chunk 3956fd5034dSChuck Lever * @sctxt: Send context for the RPC Reply 3966911f3e1SChuck Lever * @chunk: Write chunk to push 3976fd5034dSChuck Lever * 3986fd5034dSChuck Lever * Copy a Write chunk from the Call transport header to the 3996fd5034dSChuck Lever * Reply transport header. Update each segment's length field 4006fd5034dSChuck Lever * to reflect the number of bytes written in that segment. 4016fd5034dSChuck Lever * 4026fd5034dSChuck Lever * Return values: 4036fd5034dSChuck Lever * On success, returns length in bytes of the Reply XDR buffer 4046fd5034dSChuck Lever * that was consumed by the Write chunk 4056fd5034dSChuck Lever * %-EMSGSIZE on XDR buffer overflow 4066fd5034dSChuck Lever */ 4076911f3e1SChuck Lever static ssize_t svc_rdma_encode_write_chunk(struct svc_rdma_send_ctxt *sctxt, 4086911f3e1SChuck Lever const struct svc_rdma_chunk *chunk) 4099a6a180bSChuck Lever { 4106911f3e1SChuck Lever u32 remaining = chunk->ch_payload_length; 4116911f3e1SChuck Lever unsigned int segno; 4126fd5034dSChuck Lever ssize_t len, ret; 4139a6a180bSChuck Lever 4146fd5034dSChuck Lever trace_svcrdma_encode_write_chunk(remaining); 4159a6a180bSChuck Lever 4166911f3e1SChuck Lever len = 0; 4176fd5034dSChuck Lever ret = xdr_stream_encode_item_present(&sctxt->sc_stream); 4186fd5034dSChuck Lever if (ret < 0) 4196911f3e1SChuck Lever return ret; 4206fd5034dSChuck Lever len += ret; 4216fd5034dSChuck Lever 4226911f3e1SChuck Lever ret = xdr_stream_encode_u32(&sctxt->sc_stream, chunk->ch_segcount); 4236fd5034dSChuck Lever if (ret < 0) 4246911f3e1SChuck Lever return ret; 4256fd5034dSChuck Lever len += ret; 4269a6a180bSChuck Lever 4276911f3e1SChuck Lever for (segno = 0; segno < chunk->ch_segcount; segno++) { 4286911f3e1SChuck Lever ret = svc_rdma_encode_write_segment(sctxt, chunk, &remaining, segno); 4296fd5034dSChuck Lever if (ret < 0) 4306911f3e1SChuck Lever return ret; 4316fd5034dSChuck Lever len += ret; 4329a6a180bSChuck Lever } 4339a6a180bSChuck Lever 4346fd5034dSChuck Lever return len; 4359a6a180bSChuck Lever } 4369a6a180bSChuck Lever 4376fd5034dSChuck Lever /** 4386fd5034dSChuck Lever * svc_rdma_encode_write_list - Encode RPC Reply's Write chunk list 4396fd5034dSChuck Lever * @rctxt: Reply context with information about the RPC Call 4406fd5034dSChuck Lever * @sctxt: Send context for the RPC Reply 4416fd5034dSChuck Lever * 4426fd5034dSChuck Lever * Return values: 4436fd5034dSChuck Lever * On success, returns length in bytes of the Reply XDR buffer 4446fd5034dSChuck Lever * that was consumed by the Reply's Write list 4456fd5034dSChuck Lever * %-EMSGSIZE on XDR buffer overflow 4469a6a180bSChuck Lever */ 4476911f3e1SChuck Lever static ssize_t svc_rdma_encode_write_list(struct svc_rdma_recv_ctxt *rctxt, 44876e5492bSChuck Lever struct svc_rdma_send_ctxt *sctxt) 4499a6a180bSChuck Lever { 4507a1cbfa1SChuck Lever struct svc_rdma_chunk *chunk; 4516fd5034dSChuck Lever ssize_t len, ret; 4529a6a180bSChuck Lever 453f6ad7759SChuck Lever len = 0; 4546911f3e1SChuck Lever pcl_for_each_chunk(chunk, &rctxt->rc_write_pcl) { 4556911f3e1SChuck Lever ret = svc_rdma_encode_write_chunk(sctxt, chunk); 4566fd5034dSChuck Lever if (ret < 0) 4576fd5034dSChuck Lever return ret; 4586911f3e1SChuck Lever len += ret; 459f6ad7759SChuck Lever } 4609a6a180bSChuck Lever 4616fd5034dSChuck Lever /* Terminate the Write list */ 4626fd5034dSChuck Lever ret = xdr_stream_encode_item_absent(&sctxt->sc_stream); 4636fd5034dSChuck Lever if (ret < 0) 4646fd5034dSChuck Lever return ret; 4656fd5034dSChuck Lever 4666fd5034dSChuck Lever return len + ret; 4679a6a180bSChuck Lever } 4689a6a180bSChuck Lever 4696fd5034dSChuck Lever /** 4706fd5034dSChuck Lever * svc_rdma_encode_reply_chunk - Encode RPC Reply's Reply chunk 4716fd5034dSChuck Lever * @rctxt: Reply context with information about the RPC Call 4726fd5034dSChuck Lever * @sctxt: Send context for the RPC Reply 4736fd5034dSChuck Lever * @length: size in bytes of the payload in the Reply chunk 4749a6a180bSChuck Lever * 4756fd5034dSChuck Lever * Return values: 4766fd5034dSChuck Lever * On success, returns length in bytes of the Reply XDR buffer 4776fd5034dSChuck Lever * that was consumed by the Reply's Reply chunk 4786fd5034dSChuck Lever * %-EMSGSIZE on XDR buffer overflow 4796911f3e1SChuck Lever * %-E2BIG if the RPC message is larger than the Reply chunk 4809a6a180bSChuck Lever */ 4816fd5034dSChuck Lever static ssize_t 4826911f3e1SChuck Lever svc_rdma_encode_reply_chunk(struct svc_rdma_recv_ctxt *rctxt, 4836fd5034dSChuck Lever struct svc_rdma_send_ctxt *sctxt, 4846fd5034dSChuck Lever unsigned int length) 4859a6a180bSChuck Lever { 4866911f3e1SChuck Lever struct svc_rdma_chunk *chunk; 4876911f3e1SChuck Lever 4886911f3e1SChuck Lever if (pcl_is_empty(&rctxt->rc_reply_pcl)) 489ded380f1SChuck Lever return xdr_stream_encode_item_absent(&sctxt->sc_stream); 490ded380f1SChuck Lever 4916911f3e1SChuck Lever chunk = pcl_first_chunk(&rctxt->rc_reply_pcl); 4926911f3e1SChuck Lever if (length > chunk->ch_length) 4936911f3e1SChuck Lever return -E2BIG; 4946911f3e1SChuck Lever 4956911f3e1SChuck Lever chunk->ch_payload_length = length; 4966911f3e1SChuck Lever return svc_rdma_encode_write_chunk(sctxt, chunk); 4979a6a180bSChuck Lever } 4989a6a180bSChuck Lever 499*2371bcc0SChuck Lever struct svc_rdma_map_data { 500*2371bcc0SChuck Lever struct svcxprt_rdma *md_rdma; 501*2371bcc0SChuck Lever struct svc_rdma_send_ctxt *md_ctxt; 502*2371bcc0SChuck Lever }; 503*2371bcc0SChuck Lever 504*2371bcc0SChuck Lever /** 505*2371bcc0SChuck Lever * svc_rdma_page_dma_map - DMA map one page 506*2371bcc0SChuck Lever * @data: pointer to arguments 507*2371bcc0SChuck Lever * @page: struct page to DMA map 508*2371bcc0SChuck Lever * @offset: offset into the page 509*2371bcc0SChuck Lever * @len: number of bytes to map 510*2371bcc0SChuck Lever * 511*2371bcc0SChuck Lever * Returns: 512*2371bcc0SChuck Lever * %0 if DMA mapping was successful 513*2371bcc0SChuck Lever * %-EIO if the page cannot be DMA mapped 514*2371bcc0SChuck Lever */ 515*2371bcc0SChuck Lever static int svc_rdma_page_dma_map(void *data, struct page *page, 516*2371bcc0SChuck Lever unsigned long offset, unsigned int len) 5176e6092caSChuck Lever { 518*2371bcc0SChuck Lever struct svc_rdma_map_data *args = data; 519*2371bcc0SChuck Lever struct svcxprt_rdma *rdma = args->md_rdma; 520*2371bcc0SChuck Lever struct svc_rdma_send_ctxt *ctxt = args->md_ctxt; 5216e6092caSChuck Lever struct ib_device *dev = rdma->sc_cm_id->device; 5226e6092caSChuck Lever dma_addr_t dma_addr; 5236e6092caSChuck Lever 524*2371bcc0SChuck Lever ++ctxt->sc_cur_sge_no; 525*2371bcc0SChuck Lever 5266e6092caSChuck Lever dma_addr = ib_dma_map_page(dev, page, offset, len, DMA_TO_DEVICE); 5276e6092caSChuck Lever if (ib_dma_mapping_error(dev, dma_addr)) 52891a08eaeSChuck Lever goto out_maperr; 5296e6092caSChuck Lever 530*2371bcc0SChuck Lever trace_svcrdma_dma_map_page(rdma, dma_addr, len); 53125fd86ecSChuck Lever ctxt->sc_sges[ctxt->sc_cur_sge_no].addr = dma_addr; 53225fd86ecSChuck Lever ctxt->sc_sges[ctxt->sc_cur_sge_no].length = len; 5334201c746SChuck Lever ctxt->sc_send_wr.num_sge++; 5346e6092caSChuck Lever return 0; 53591a08eaeSChuck Lever 53691a08eaeSChuck Lever out_maperr: 537*2371bcc0SChuck Lever trace_svcrdma_dma_map_err(rdma, dma_addr, len); 53891a08eaeSChuck Lever return -EIO; 5396e6092caSChuck Lever } 5406e6092caSChuck Lever 541*2371bcc0SChuck Lever /** 542*2371bcc0SChuck Lever * svc_rdma_iov_dma_map - DMA map an iovec 543*2371bcc0SChuck Lever * @data: pointer to arguments 544*2371bcc0SChuck Lever * @iov: kvec to DMA map 545*2371bcc0SChuck Lever * 546*2371bcc0SChuck Lever * ib_dma_map_page() is used here because svc_rdma_dma_unmap() 547f016f305SChuck Lever * handles DMA-unmap and it uses ib_dma_unmap_page() exclusively. 548*2371bcc0SChuck Lever * 549*2371bcc0SChuck Lever * Returns: 550*2371bcc0SChuck Lever * %0 if DMA mapping was successful 551*2371bcc0SChuck Lever * %-EIO if the iovec cannot be DMA mapped 552f016f305SChuck Lever */ 553*2371bcc0SChuck Lever static int svc_rdma_iov_dma_map(void *data, const struct kvec *iov) 554f016f305SChuck Lever { 555*2371bcc0SChuck Lever if (!iov->iov_len) 556*2371bcc0SChuck Lever return 0; 557*2371bcc0SChuck Lever return svc_rdma_page_dma_map(data, virt_to_page(iov->iov_base), 558*2371bcc0SChuck Lever offset_in_page(iov->iov_base), 559*2371bcc0SChuck Lever iov->iov_len); 560*2371bcc0SChuck Lever } 561*2371bcc0SChuck Lever 562*2371bcc0SChuck Lever /** 563*2371bcc0SChuck Lever * svc_rdma_xb_dma_map - DMA map all segments of an xdr_buf 564*2371bcc0SChuck Lever * @xdr: xdr_buf containing portion of an RPC message to transmit 565*2371bcc0SChuck Lever * @data: pointer to arguments 566*2371bcc0SChuck Lever * 567*2371bcc0SChuck Lever * Returns: 568*2371bcc0SChuck Lever * %0 if DMA mapping was successful 569*2371bcc0SChuck Lever * %-EIO if DMA mapping failed 570*2371bcc0SChuck Lever * 571*2371bcc0SChuck Lever * On failure, any DMA mappings that have been already done must be 572*2371bcc0SChuck Lever * unmapped by the caller. 573*2371bcc0SChuck Lever */ 574*2371bcc0SChuck Lever static int svc_rdma_xb_dma_map(const struct xdr_buf *xdr, void *data) 575*2371bcc0SChuck Lever { 576*2371bcc0SChuck Lever unsigned int len, remaining; 577*2371bcc0SChuck Lever unsigned long pageoff; 578*2371bcc0SChuck Lever struct page **ppages; 579*2371bcc0SChuck Lever int ret; 580*2371bcc0SChuck Lever 581*2371bcc0SChuck Lever ret = svc_rdma_iov_dma_map(data, &xdr->head[0]); 582*2371bcc0SChuck Lever if (ret < 0) 583*2371bcc0SChuck Lever return ret; 584*2371bcc0SChuck Lever 585*2371bcc0SChuck Lever ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT); 586*2371bcc0SChuck Lever pageoff = offset_in_page(xdr->page_base); 587*2371bcc0SChuck Lever remaining = xdr->page_len; 588*2371bcc0SChuck Lever while (remaining) { 589*2371bcc0SChuck Lever len = min_t(u32, PAGE_SIZE - pageoff, remaining); 590*2371bcc0SChuck Lever 591*2371bcc0SChuck Lever ret = svc_rdma_page_dma_map(data, *ppages++, pageoff, len); 592*2371bcc0SChuck Lever if (ret < 0) 593*2371bcc0SChuck Lever return ret; 594*2371bcc0SChuck Lever 595*2371bcc0SChuck Lever remaining -= len; 596*2371bcc0SChuck Lever pageoff = 0; 597*2371bcc0SChuck Lever } 598*2371bcc0SChuck Lever 599*2371bcc0SChuck Lever ret = svc_rdma_iov_dma_map(data, &xdr->tail[0]); 600*2371bcc0SChuck Lever if (ret < 0) 601*2371bcc0SChuck Lever return ret; 602*2371bcc0SChuck Lever 603*2371bcc0SChuck Lever return xdr->len; 604f016f305SChuck Lever } 605f016f305SChuck Lever 6069d0b09d5SChuck Lever struct svc_rdma_pullup_data { 6079d0b09d5SChuck Lever u8 *pd_dest; 6089d0b09d5SChuck Lever unsigned int pd_length; 6099d0b09d5SChuck Lever unsigned int pd_num_sges; 6109d0b09d5SChuck Lever }; 6119d0b09d5SChuck Lever 6129d0b09d5SChuck Lever /** 6139d0b09d5SChuck Lever * svc_rdma_xb_count_sges - Count how many SGEs will be needed 6149d0b09d5SChuck Lever * @xdr: xdr_buf containing portion of an RPC message to transmit 6159d0b09d5SChuck Lever * @data: pointer to arguments 6169d0b09d5SChuck Lever * 6179d0b09d5SChuck Lever * Returns: 6189d0b09d5SChuck Lever * Number of SGEs needed to Send the contents of @xdr inline 6199d0b09d5SChuck Lever */ 6209d0b09d5SChuck Lever static int svc_rdma_xb_count_sges(const struct xdr_buf *xdr, 6219d0b09d5SChuck Lever void *data) 6229d0b09d5SChuck Lever { 6239d0b09d5SChuck Lever struct svc_rdma_pullup_data *args = data; 6249d0b09d5SChuck Lever unsigned int remaining; 6259d0b09d5SChuck Lever unsigned long offset; 6269d0b09d5SChuck Lever 6279d0b09d5SChuck Lever if (xdr->head[0].iov_len) 6289d0b09d5SChuck Lever ++args->pd_num_sges; 6299d0b09d5SChuck Lever 6309d0b09d5SChuck Lever offset = offset_in_page(xdr->page_base); 6319d0b09d5SChuck Lever remaining = xdr->page_len; 6329d0b09d5SChuck Lever while (remaining) { 6339d0b09d5SChuck Lever ++args->pd_num_sges; 6349d0b09d5SChuck Lever remaining -= min_t(u32, PAGE_SIZE - offset, remaining); 6359d0b09d5SChuck Lever offset = 0; 6369d0b09d5SChuck Lever } 6379d0b09d5SChuck Lever 6389d0b09d5SChuck Lever if (xdr->tail[0].iov_len) 6399d0b09d5SChuck Lever ++args->pd_num_sges; 6409d0b09d5SChuck Lever 6419d0b09d5SChuck Lever args->pd_length += xdr->len; 6429d0b09d5SChuck Lever return 0; 6439d0b09d5SChuck Lever } 6449d0b09d5SChuck Lever 6456e6092caSChuck Lever /** 6464554755eSChuck Lever * svc_rdma_pull_up_needed - Determine whether to use pull-up 6474554755eSChuck Lever * @rdma: controlling transport 6480dabe948SChuck Lever * @sctxt: send_ctxt for the Send WR 6494554755eSChuck Lever * @rctxt: Write and Reply chunks provided by client 6504554755eSChuck Lever * @xdr: xdr_buf containing RPC message to transmit 6514554755eSChuck Lever * 6524554755eSChuck Lever * Returns: 6534554755eSChuck Lever * %true if pull-up must be used 6544554755eSChuck Lever * %false otherwise 655e248aa7bSChuck Lever */ 6569d0b09d5SChuck Lever static bool svc_rdma_pull_up_needed(const struct svcxprt_rdma *rdma, 6579d0b09d5SChuck Lever const struct svc_rdma_send_ctxt *sctxt, 6584554755eSChuck Lever const struct svc_rdma_recv_ctxt *rctxt, 6599d0b09d5SChuck Lever const struct xdr_buf *xdr) 660e248aa7bSChuck Lever { 6619d0b09d5SChuck Lever /* Resources needed for the transport header */ 6629d0b09d5SChuck Lever struct svc_rdma_pullup_data args = { 6639d0b09d5SChuck Lever .pd_length = sctxt->sc_hdrbuf.len, 6649d0b09d5SChuck Lever .pd_num_sges = 1, 6659d0b09d5SChuck Lever }; 6669d0b09d5SChuck Lever int ret; 667e248aa7bSChuck Lever 6689d0b09d5SChuck Lever ret = pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, 6699d0b09d5SChuck Lever svc_rdma_xb_count_sges, &args); 6709d0b09d5SChuck Lever if (ret < 0) 6719d0b09d5SChuck Lever return false; 6729d0b09d5SChuck Lever 6739d0b09d5SChuck Lever if (args.pd_length < RPCRDMA_PULLUP_THRESH) 6740dabe948SChuck Lever return true; 6759d0b09d5SChuck Lever return args.pd_num_sges >= rdma->sc_max_send_sges; 6769d0b09d5SChuck Lever } 6770dabe948SChuck Lever 6789d0b09d5SChuck Lever /** 6799d0b09d5SChuck Lever * svc_rdma_xb_linearize - Copy region of xdr_buf to flat buffer 6809d0b09d5SChuck Lever * @xdr: xdr_buf containing portion of an RPC message to copy 6819d0b09d5SChuck Lever * @data: pointer to arguments 6829d0b09d5SChuck Lever * 6839d0b09d5SChuck Lever * Returns: 6849d0b09d5SChuck Lever * Always zero. 6850dabe948SChuck Lever */ 6869d0b09d5SChuck Lever static int svc_rdma_xb_linearize(const struct xdr_buf *xdr, 6879d0b09d5SChuck Lever void *data) 6889d0b09d5SChuck Lever { 6899d0b09d5SChuck Lever struct svc_rdma_pullup_data *args = data; 6909d0b09d5SChuck Lever unsigned int len, remaining; 691e248aa7bSChuck Lever unsigned long pageoff; 6929d0b09d5SChuck Lever struct page **ppages; 693e248aa7bSChuck Lever 6949d0b09d5SChuck Lever if (xdr->head[0].iov_len) { 6959d0b09d5SChuck Lever memcpy(args->pd_dest, xdr->head[0].iov_base, xdr->head[0].iov_len); 6969d0b09d5SChuck Lever args->pd_dest += xdr->head[0].iov_len; 6979d0b09d5SChuck Lever } 6989d0b09d5SChuck Lever 6999d0b09d5SChuck Lever ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT); 7009d0b09d5SChuck Lever pageoff = offset_in_page(xdr->page_base); 701e248aa7bSChuck Lever remaining = xdr->page_len; 702e248aa7bSChuck Lever while (remaining) { 7039d0b09d5SChuck Lever len = min_t(u32, PAGE_SIZE - pageoff, remaining); 7049d0b09d5SChuck Lever memcpy(args->pd_dest, page_address(*ppages) + pageoff, len); 7059d0b09d5SChuck Lever remaining -= len; 7069d0b09d5SChuck Lever args->pd_dest += len; 707e248aa7bSChuck Lever pageoff = 0; 7089d0b09d5SChuck Lever ppages++; 709e248aa7bSChuck Lever } 710e248aa7bSChuck Lever 7119d0b09d5SChuck Lever if (xdr->tail[0].iov_len) { 7129d0b09d5SChuck Lever memcpy(args->pd_dest, xdr->tail[0].iov_base, xdr->tail[0].iov_len); 7139d0b09d5SChuck Lever args->pd_dest += xdr->tail[0].iov_len; 7149d0b09d5SChuck Lever } 715e248aa7bSChuck Lever 7169d0b09d5SChuck Lever args->pd_length += xdr->len; 7179d0b09d5SChuck Lever return 0; 718e248aa7bSChuck Lever } 719e248aa7bSChuck Lever 7204554755eSChuck Lever /** 7214554755eSChuck Lever * svc_rdma_pull_up_reply_msg - Copy Reply into a single buffer 7224554755eSChuck Lever * @rdma: controlling transport 7234554755eSChuck Lever * @sctxt: send_ctxt for the Send WR; xprt hdr is already prepared 7244554755eSChuck Lever * @rctxt: Write and Reply chunks provided by client 7254554755eSChuck Lever * @xdr: prepared xdr_buf containing RPC message 7264554755eSChuck Lever * 7274554755eSChuck Lever * The device is not capable of sending the reply directly. 7284554755eSChuck Lever * Assemble the elements of @xdr into the transport header buffer. 7294554755eSChuck Lever * 7309d0b09d5SChuck Lever * Assumptions: 7319d0b09d5SChuck Lever * pull_up_needed has determined that @xdr will fit in the buffer. 7329d0b09d5SChuck Lever * 7339d0b09d5SChuck Lever * Returns: 7349d0b09d5SChuck Lever * %0 if pull-up was successful 7359d0b09d5SChuck Lever * %-EMSGSIZE if a buffer manipulation problem occurred 736e248aa7bSChuck Lever */ 7379d0b09d5SChuck Lever static int svc_rdma_pull_up_reply_msg(const struct svcxprt_rdma *rdma, 7384554755eSChuck Lever struct svc_rdma_send_ctxt *sctxt, 7394554755eSChuck Lever const struct svc_rdma_recv_ctxt *rctxt, 7404554755eSChuck Lever const struct xdr_buf *xdr) 741e248aa7bSChuck Lever { 7429d0b09d5SChuck Lever struct svc_rdma_pullup_data args = { 7439d0b09d5SChuck Lever .pd_dest = sctxt->sc_xprt_buf + sctxt->sc_hdrbuf.len, 7449d0b09d5SChuck Lever }; 7459d0b09d5SChuck Lever int ret; 746e248aa7bSChuck Lever 7479d0b09d5SChuck Lever ret = pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, 7489d0b09d5SChuck Lever svc_rdma_xb_linearize, &args); 7499d0b09d5SChuck Lever if (ret < 0) 7509d0b09d5SChuck Lever return ret; 751e248aa7bSChuck Lever 7529d0b09d5SChuck Lever sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len + args.pd_length; 7539d0b09d5SChuck Lever trace_svcrdma_send_pullup(sctxt, args.pd_length); 754e248aa7bSChuck Lever return 0; 755e248aa7bSChuck Lever } 756e248aa7bSChuck Lever 7574554755eSChuck Lever /* svc_rdma_map_reply_msg - DMA map the buffer holding RPC message 75899722fe4SChuck Lever * @rdma: controlling transport 7594554755eSChuck Lever * @sctxt: send_ctxt for the Send WR 7604554755eSChuck Lever * @rctxt: Write and Reply chunks provided by client 76199722fe4SChuck Lever * @xdr: prepared xdr_buf containing RPC message 76299722fe4SChuck Lever * 763*2371bcc0SChuck Lever * Returns: 764*2371bcc0SChuck Lever * %0 if DMA mapping was successful. 765*2371bcc0SChuck Lever * %-EMSGSIZE if a buffer manipulation problem occurred 766*2371bcc0SChuck Lever * %-EIO if DMA mapping failed 7679a6a180bSChuck Lever * 768*2371bcc0SChuck Lever * The Send WR's num_sge field is set in all cases. 769c06b540aSTom Tucker */ 77099722fe4SChuck Lever int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma, 7714554755eSChuck Lever struct svc_rdma_send_ctxt *sctxt, 7724554755eSChuck Lever const struct svc_rdma_recv_ctxt *rctxt, 773*2371bcc0SChuck Lever const struct xdr_buf *xdr) 774c06b540aSTom Tucker { 775*2371bcc0SChuck Lever struct svc_rdma_map_data args = { 776*2371bcc0SChuck Lever .md_rdma = rdma, 777*2371bcc0SChuck Lever .md_ctxt = sctxt, 778*2371bcc0SChuck Lever }; 779c06b540aSTom Tucker 780aee4b74aSChuck Lever /* Set up the (persistently-mapped) transport header SGE. */ 781aee4b74aSChuck Lever sctxt->sc_send_wr.num_sge = 1; 782aee4b74aSChuck Lever sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len; 783aee4b74aSChuck Lever 784aee4b74aSChuck Lever /* If there is a Reply chunk, nothing follows the transport 785aee4b74aSChuck Lever * header, and we're done here. 786aee4b74aSChuck Lever */ 787*2371bcc0SChuck Lever if (!pcl_is_empty(&rctxt->rc_reply_pcl)) 788aee4b74aSChuck Lever return 0; 789aee4b74aSChuck Lever 790aee4b74aSChuck Lever /* For pull-up, svc_rdma_send() will sync the transport header. 791aee4b74aSChuck Lever * No additional DMA mapping is necessary. 792aee4b74aSChuck Lever */ 7930dabe948SChuck Lever if (svc_rdma_pull_up_needed(rdma, sctxt, rctxt, xdr)) 7944554755eSChuck Lever return svc_rdma_pull_up_reply_msg(rdma, sctxt, rctxt, xdr); 795e248aa7bSChuck Lever 796*2371bcc0SChuck Lever return pcl_process_nonpayloads(&rctxt->rc_write_pcl, xdr, 797*2371bcc0SChuck Lever svc_rdma_xb_dma_map, &args); 798c06b540aSTom Tucker } 799c06b540aSTom Tucker 800c55ab070SChuck Lever /* The svc_rqst and all resources it owns are released as soon as 801c55ab070SChuck Lever * svc_rdma_sendto returns. Transfer pages under I/O to the ctxt 802c55ab070SChuck Lever * so they are released by the Send completion handler. 803c55ab070SChuck Lever */ 804c55ab070SChuck Lever static void svc_rdma_save_io_pages(struct svc_rqst *rqstp, 8054201c746SChuck Lever struct svc_rdma_send_ctxt *ctxt) 806c55ab070SChuck Lever { 807c55ab070SChuck Lever int i, pages = rqstp->rq_next_page - rqstp->rq_respages; 808c55ab070SChuck Lever 8094201c746SChuck Lever ctxt->sc_page_count += pages; 810c55ab070SChuck Lever for (i = 0; i < pages; i++) { 81199722fe4SChuck Lever ctxt->sc_pages[i] = rqstp->rq_respages[i]; 812c55ab070SChuck Lever rqstp->rq_respages[i] = NULL; 813c55ab070SChuck Lever } 814a53d5cb0SChuck Lever 815a53d5cb0SChuck Lever /* Prevent svc_xprt_release from releasing pages in rq_pages */ 816a53d5cb0SChuck Lever rqstp->rq_next_page = rqstp->rq_respages; 817c55ab070SChuck Lever } 818c55ab070SChuck Lever 8199a6a180bSChuck Lever /* Prepare the portion of the RPC Reply that will be transmitted 8209a6a180bSChuck Lever * via RDMA Send. The RPC-over-RDMA transport header is prepared 8214201c746SChuck Lever * in sc_sges[0], and the RPC xdr_buf is prepared in following sges. 8229a6a180bSChuck Lever * 8239a6a180bSChuck Lever * Depending on whether a Write list or Reply chunk is present, 8249a6a180bSChuck Lever * the server may send all, a portion of, or none of the xdr_buf. 8254201c746SChuck Lever * In the latter case, only the transport header (sc_sges[0]) is 8269a6a180bSChuck Lever * transmitted. 8279a6a180bSChuck Lever * 8289a6a180bSChuck Lever * RDMA Send is the last step of transmitting an RPC reply. Pages 8299a6a180bSChuck Lever * involved in the earlier RDMA Writes are here transferred out 83097bce634SChuck Lever * of the rqstp and into the sctxt's page array. These pages are 8319a6a180bSChuck Lever * DMA unmapped by each Write completion, but the subsequent Send 8329a6a180bSChuck Lever * completion finally releases these pages. 8339a6a180bSChuck Lever * 8349a6a180bSChuck Lever * Assumptions: 8359a6a180bSChuck Lever * - The Reply's transport header will never be larger than a page. 836c06b540aSTom Tucker */ 8379a6a180bSChuck Lever static int svc_rdma_send_reply_msg(struct svcxprt_rdma *rdma, 83897bce634SChuck Lever struct svc_rdma_send_ctxt *sctxt, 839db9602e4SChuck Lever const struct svc_rdma_recv_ctxt *rctxt, 840db9602e4SChuck Lever struct svc_rqst *rqstp) 841c06b540aSTom Tucker { 8429a6a180bSChuck Lever int ret; 8430e7f011aSTom Tucker 844aee4b74aSChuck Lever ret = svc_rdma_map_reply_msg(rdma, sctxt, rctxt, &rqstp->rq_res); 8459a6a180bSChuck Lever if (ret < 0) 84699722fe4SChuck Lever return ret; 847c06b540aSTom Tucker 84897bce634SChuck Lever svc_rdma_save_io_pages(rqstp, sctxt); 8490bf48289SSteve Wise 85097bce634SChuck Lever if (rctxt->rc_inv_rkey) { 85197bce634SChuck Lever sctxt->sc_send_wr.opcode = IB_WR_SEND_WITH_INV; 85297bce634SChuck Lever sctxt->sc_send_wr.ex.invalidate_rkey = rctxt->rc_inv_rkey; 85397bce634SChuck Lever } else { 85497bce634SChuck Lever sctxt->sc_send_wr.opcode = IB_WR_SEND; 855986b7889SChuck Lever } 85617f70f8dSChuck Lever return svc_rdma_send(rdma, sctxt); 857c06b540aSTom Tucker } 858c06b540aSTom Tucker 859c65b326bSChuck Lever /** 860c65b326bSChuck Lever * svc_rdma_send_error_msg - Send an RPC/RDMA v1 error response 861c65b326bSChuck Lever * @rdma: controlling transport context 862c65b326bSChuck Lever * @sctxt: Send context for the response 863c65b326bSChuck Lever * @rctxt: Receive context for incoming bad message 864c65b326bSChuck Lever * @status: negative errno indicating error that occurred 8654757d90bSChuck Lever * 866c65b326bSChuck Lever * Given the client-provided Read, Write, and Reply chunks, the 867c65b326bSChuck Lever * server was not able to parse the Call or form a complete Reply. 868c65b326bSChuck Lever * Return an RDMA_ERROR message so the client can retire the RPC 869c65b326bSChuck Lever * transaction. 870c65b326bSChuck Lever * 871c65b326bSChuck Lever * The caller does not have to release @sctxt. It is released by 872c65b326bSChuck Lever * Send completion, or by this function on error. 8734757d90bSChuck Lever */ 874c65b326bSChuck Lever void svc_rdma_send_error_msg(struct svcxprt_rdma *rdma, 875d1f6e236SChuck Lever struct svc_rdma_send_ctxt *sctxt, 8764f200bd8SChuck Lever struct svc_rdma_recv_ctxt *rctxt, 8774f200bd8SChuck Lever int status) 8784757d90bSChuck Lever { 8796fd5034dSChuck Lever __be32 *rdma_argp = rctxt->rc_recv_buf; 8804757d90bSChuck Lever __be32 *p; 8814757d90bSChuck Lever 882d1f6e236SChuck Lever rpcrdma_set_xdrlen(&sctxt->sc_hdrbuf, 0); 883d1f6e236SChuck Lever xdr_init_encode(&sctxt->sc_stream, &sctxt->sc_hdrbuf, 884d1f6e236SChuck Lever sctxt->sc_xprt_buf, NULL); 8856fd5034dSChuck Lever 8864f200bd8SChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, 8874f200bd8SChuck Lever rpcrdma_fixed_maxsz * sizeof(*p)); 8886fd5034dSChuck Lever if (!p) 889605c61beSChuck Lever goto put_ctxt; 8906fd5034dSChuck Lever 8916fd5034dSChuck Lever *p++ = *rdma_argp; 8926fd5034dSChuck Lever *p++ = *(rdma_argp + 1); 8936fd5034dSChuck Lever *p++ = rdma->sc_fc_credits; 8944f200bd8SChuck Lever *p = rdma_error; 8954f200bd8SChuck Lever 8964f200bd8SChuck Lever switch (status) { 8974f200bd8SChuck Lever case -EPROTONOSUPPORT: 8984f200bd8SChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, 3 * sizeof(*p)); 8994f200bd8SChuck Lever if (!p) 900605c61beSChuck Lever goto put_ctxt; 9014f200bd8SChuck Lever 9024f200bd8SChuck Lever *p++ = err_vers; 9034f200bd8SChuck Lever *p++ = rpcrdma_version; 9044f200bd8SChuck Lever *p = rpcrdma_version; 9054f200bd8SChuck Lever trace_svcrdma_err_vers(*rdma_argp); 9064f200bd8SChuck Lever break; 9074f200bd8SChuck Lever default: 9084f200bd8SChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, sizeof(*p)); 9094f200bd8SChuck Lever if (!p) 910605c61beSChuck Lever goto put_ctxt; 9114f200bd8SChuck Lever 9124757d90bSChuck Lever *p = err_chunk; 9136fd5034dSChuck Lever trace_svcrdma_err_chunk(*rdma_argp); 9144f200bd8SChuck Lever } 9156fd5034dSChuck Lever 916c65b326bSChuck Lever /* Remote Invalidation is skipped for simplicity. */ 917d1f6e236SChuck Lever sctxt->sc_send_wr.num_sge = 1; 918d1f6e236SChuck Lever sctxt->sc_send_wr.opcode = IB_WR_SEND; 919d1f6e236SChuck Lever sctxt->sc_sges[0].length = sctxt->sc_hdrbuf.len; 92017f70f8dSChuck Lever if (svc_rdma_send(rdma, sctxt)) 921605c61beSChuck Lever goto put_ctxt; 922605c61beSChuck Lever return; 923605c61beSChuck Lever 924605c61beSChuck Lever put_ctxt: 925605c61beSChuck Lever svc_rdma_send_ctxt_put(rdma, sctxt); 92699722fe4SChuck Lever } 92799722fe4SChuck Lever 9289a6a180bSChuck Lever /** 9299a6a180bSChuck Lever * svc_rdma_sendto - Transmit an RPC reply 9309a6a180bSChuck Lever * @rqstp: processed RPC request, reply XDR already in ::rq_res 9319a6a180bSChuck Lever * 9329a6a180bSChuck Lever * Any resources still associated with @rqstp are released upon return. 9339a6a180bSChuck Lever * If no reply message was possible, the connection is closed. 9349a6a180bSChuck Lever * 9359a6a180bSChuck Lever * Returns: 9369a6a180bSChuck Lever * %0 if an RPC reply has been successfully posted, 9379a6a180bSChuck Lever * %-ENOMEM if a resource shortage occurred (connection is lost), 9389a6a180bSChuck Lever * %-ENOTCONN if posting failed (connection is lost). 9399a6a180bSChuck Lever */ 940c06b540aSTom Tucker int svc_rdma_sendto(struct svc_rqst *rqstp) 941c06b540aSTom Tucker { 942c06b540aSTom Tucker struct svc_xprt *xprt = rqstp->rq_xprt; 943c06b540aSTom Tucker struct svcxprt_rdma *rdma = 944c06b540aSTom Tucker container_of(xprt, struct svcxprt_rdma, sc_xprt); 9453a88092eSChuck Lever struct svc_rdma_recv_ctxt *rctxt = rqstp->rq_xprt_ctxt; 9462fe8c446SChuck Lever __be32 *rdma_argp = rctxt->rc_recv_buf; 94799722fe4SChuck Lever struct svc_rdma_send_ctxt *sctxt; 9486fd5034dSChuck Lever __be32 *p; 9499a6a180bSChuck Lever int ret; 950c06b540aSTom Tucker 951ca4faf54SChuck Lever ret = -ENOTCONN; 952ca4faf54SChuck Lever if (svc_xprt_is_dead(xprt)) 953ca4faf54SChuck Lever goto err0; 954ca4faf54SChuck Lever 95578da2b3cSChuck Lever ret = -ENOMEM; 95699722fe4SChuck Lever sctxt = svc_rdma_send_ctxt_get(rdma); 95799722fe4SChuck Lever if (!sctxt) 95878da2b3cSChuck Lever goto err0; 95998fc21d3SChuck Lever 9606fd5034dSChuck Lever p = xdr_reserve_space(&sctxt->sc_stream, 9616fd5034dSChuck Lever rpcrdma_fixed_maxsz * sizeof(*p)); 9626fd5034dSChuck Lever if (!p) 9636fd5034dSChuck Lever goto err0; 964ded380f1SChuck Lever 965ded380f1SChuck Lever ret = svc_rdma_send_reply_chunk(rdma, rctxt, &rqstp->rq_res); 966ded380f1SChuck Lever if (ret < 0) 967ded380f1SChuck Lever goto err2; 968ded380f1SChuck Lever 9699a6a180bSChuck Lever *p++ = *rdma_argp; 9709a6a180bSChuck Lever *p++ = *(rdma_argp + 1); 97198fc21d3SChuck Lever *p++ = rdma->sc_fc_credits; 9726911f3e1SChuck Lever *p = pcl_is_empty(&rctxt->rc_reply_pcl) ? rdma_msg : rdma_nomsg; 97398fc21d3SChuck Lever 9746fd5034dSChuck Lever if (svc_rdma_encode_read_list(sctxt) < 0) 9756fd5034dSChuck Lever goto err0; 97676e5492bSChuck Lever if (svc_rdma_encode_write_list(rctxt, sctxt) < 0) 9776fd5034dSChuck Lever goto err0; 9786fd5034dSChuck Lever if (svc_rdma_encode_reply_chunk(rctxt, sctxt, ret) < 0) 9796fd5034dSChuck Lever goto err0; 980c06b540aSTom Tucker 981db9602e4SChuck Lever ret = svc_rdma_send_reply_msg(rdma, sctxt, rctxt, rqstp); 9823e1eeb98SChuck Lever if (ret < 0) 98399722fe4SChuck Lever goto err1; 98423cf1ee1SChuck Lever return 0; 985afd566eaSTom Tucker 9864757d90bSChuck Lever err2: 987b20dae70SColin Ian King if (ret != -E2BIG && ret != -EINVAL) 9884757d90bSChuck Lever goto err1; 9894757d90bSChuck Lever 9906e9fab70SChuck Lever /* Send completion releases payload pages that were part 9916e9fab70SChuck Lever * of previously posted RDMA Writes. 9926e9fab70SChuck Lever */ 9936e9fab70SChuck Lever svc_rdma_save_io_pages(rqstp, sctxt); 994605c61beSChuck Lever svc_rdma_send_error_msg(rdma, sctxt, rctxt, ret); 99523cf1ee1SChuck Lever return 0; 9964757d90bSChuck Lever 997afd566eaSTom Tucker err1: 99899722fe4SChuck Lever svc_rdma_send_ctxt_put(rdma, sctxt); 999afd566eaSTom Tucker err0: 10003f8f25c6SChuck Lever trace_svcrdma_send_err(rqstp, ret); 10019a6a180bSChuck Lever set_bit(XPT_CLOSE, &xprt->xpt_flags); 100223cf1ee1SChuck Lever return -ENOTCONN; 1003c06b540aSTom Tucker } 100441205539SChuck Lever 100541205539SChuck Lever /** 100603493bcaSChuck Lever * svc_rdma_result_payload - special processing for a result payload 100741205539SChuck Lever * @rqstp: svc_rqst to operate on 100841205539SChuck Lever * @offset: payload's byte offset in @xdr 100941205539SChuck Lever * @length: size of payload, in bytes 101041205539SChuck Lever * 1011f6ad7759SChuck Lever * Return values: 1012f6ad7759SChuck Lever * %0 if successful or nothing needed to be done 1013f6ad7759SChuck Lever * %-EMSGSIZE on XDR buffer overflow 1014f6ad7759SChuck Lever * %-E2BIG if the payload was larger than the Write chunk 1015f6ad7759SChuck Lever * %-EINVAL if client provided too many segments 1016f6ad7759SChuck Lever * %-ENOMEM if rdma_rw context pool was exhausted 1017f6ad7759SChuck Lever * %-ENOTCONN if posting failed (connection is lost) 1018f6ad7759SChuck Lever * %-EIO if rdma_rw initialization failed (DMA mapping, etc) 101941205539SChuck Lever */ 102003493bcaSChuck Lever int svc_rdma_result_payload(struct svc_rqst *rqstp, unsigned int offset, 102141205539SChuck Lever unsigned int length) 102241205539SChuck Lever { 102341205539SChuck Lever struct svc_rdma_recv_ctxt *rctxt = rqstp->rq_xprt_ctxt; 10247a1cbfa1SChuck Lever struct svc_rdma_chunk *chunk; 1025f6ad7759SChuck Lever struct svcxprt_rdma *rdma; 1026f6ad7759SChuck Lever struct xdr_buf subbuf; 1027f6ad7759SChuck Lever int ret; 1028f6ad7759SChuck Lever 10297a1cbfa1SChuck Lever chunk = rctxt->rc_cur_result_payload; 10307a1cbfa1SChuck Lever if (!length || !chunk) 1031f6ad7759SChuck Lever return 0; 10327a1cbfa1SChuck Lever rctxt->rc_cur_result_payload = 10337a1cbfa1SChuck Lever pcl_next_chunk(&rctxt->rc_write_pcl, chunk); 10347a1cbfa1SChuck Lever if (length > chunk->ch_length) 10357a1cbfa1SChuck Lever return -E2BIG; 103641205539SChuck Lever 10377a1cbfa1SChuck Lever chunk->ch_position = offset; 10387a1cbfa1SChuck Lever chunk->ch_payload_length = length; 103941205539SChuck Lever 1040f6ad7759SChuck Lever if (xdr_buf_subsegment(&rqstp->rq_res, &subbuf, offset, length)) 1041f6ad7759SChuck Lever return -EMSGSIZE; 1042f6ad7759SChuck Lever 1043f6ad7759SChuck Lever rdma = container_of(rqstp->rq_xprt, struct svcxprt_rdma, sc_xprt); 10447a1cbfa1SChuck Lever ret = svc_rdma_send_write_chunk(rdma, chunk, &subbuf); 1045f6ad7759SChuck Lever if (ret < 0) 1046f6ad7759SChuck Lever return ret; 104741205539SChuck Lever return 0; 104841205539SChuck Lever } 1049