/* * Copyright (c) 2014 Open Grid Computing, Inc. All rights reserved. * Copyright (c) 2005-2007 Network Appliance, Inc. All rights reserved. * * This software is available to you under a choice of one of two * licenses. You may choose to be licensed under the terms of the GNU * General Public License (GPL) Version 2, available from the file * COPYING in the main directory of this source tree, or the BSD-type * license below: * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials provided * with the distribution. * * Neither the name of the Network Appliance, Inc. nor the names of * its contributors may be used to endorse or promote products * derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * Author: Tom Tucker */ #include #include #include #include #include #include #include #include #include #include #include #include #include "xprt_rdma.h" #define RPCDBG_FACILITY RPCDBG_SVCXPRT static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *, int); static struct svc_xprt *svc_rdma_create(struct svc_serv *serv, struct net *net, struct sockaddr *sa, int salen, int flags); static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt); static void svc_rdma_release_rqst(struct svc_rqst *); static void dto_tasklet_func(unsigned long data); static void svc_rdma_detach(struct svc_xprt *xprt); static void svc_rdma_free(struct svc_xprt *xprt); static int svc_rdma_has_wspace(struct svc_xprt *xprt); static int svc_rdma_secure_port(struct svc_rqst *); static void rq_cq_reap(struct svcxprt_rdma *xprt); static void sq_cq_reap(struct svcxprt_rdma *xprt); static DECLARE_TASKLET(dto_tasklet, dto_tasklet_func, 0UL); static DEFINE_SPINLOCK(dto_lock); static LIST_HEAD(dto_xprt_q); static struct svc_xprt_ops svc_rdma_ops = { .xpo_create = svc_rdma_create, .xpo_recvfrom = svc_rdma_recvfrom, .xpo_sendto = svc_rdma_sendto, .xpo_release_rqst = svc_rdma_release_rqst, .xpo_detach = svc_rdma_detach, .xpo_free = svc_rdma_free, .xpo_prep_reply_hdr = svc_rdma_prep_reply_hdr, .xpo_has_wspace = svc_rdma_has_wspace, .xpo_accept = svc_rdma_accept, .xpo_secure_port = svc_rdma_secure_port, }; struct svc_xprt_class svc_rdma_class = { .xcl_name = "rdma", .xcl_owner = THIS_MODULE, .xcl_ops = &svc_rdma_ops, .xcl_max_payload = RPCSVC_MAXPAYLOAD_RDMA, .xcl_ident = XPRT_TRANSPORT_RDMA, }; #if defined(CONFIG_SUNRPC_BACKCHANNEL) static struct svc_xprt *svc_rdma_bc_create(struct svc_serv *, struct net *, struct sockaddr *, int, int); static void svc_rdma_bc_detach(struct svc_xprt *); static void svc_rdma_bc_free(struct svc_xprt *); static struct svc_xprt_ops svc_rdma_bc_ops = { .xpo_create = svc_rdma_bc_create, .xpo_detach = svc_rdma_bc_detach, .xpo_free = svc_rdma_bc_free, .xpo_prep_reply_hdr = svc_rdma_prep_reply_hdr, .xpo_secure_port = svc_rdma_secure_port, }; struct svc_xprt_class svc_rdma_bc_class = { .xcl_name = "rdma-bc", .xcl_owner = THIS_MODULE, .xcl_ops = &svc_rdma_bc_ops, .xcl_max_payload = (1024 - RPCRDMA_HDRLEN_MIN) }; static struct svc_xprt *svc_rdma_bc_create(struct svc_serv *serv, struct net *net, struct sockaddr *sa, int salen, int flags) { struct svcxprt_rdma *cma_xprt; struct svc_xprt *xprt; cma_xprt = rdma_create_xprt(serv, 0); if (!cma_xprt) return ERR_PTR(-ENOMEM); xprt = &cma_xprt->sc_xprt; svc_xprt_init(net, &svc_rdma_bc_class, xprt, serv); serv->sv_bc_xprt = xprt; dprintk("svcrdma: %s(%p)\n", __func__, xprt); return xprt; } static void svc_rdma_bc_detach(struct svc_xprt *xprt) { dprintk("svcrdma: %s(%p)\n", __func__, xprt); } static void svc_rdma_bc_free(struct svc_xprt *xprt) { struct svcxprt_rdma *rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt); dprintk("svcrdma: %s(%p)\n", __func__, xprt); if (xprt) kfree(rdma); } #endif /* CONFIG_SUNRPC_BACKCHANNEL */ static struct svc_rdma_op_ctxt *alloc_ctxt(struct svcxprt_rdma *xprt, gfp_t flags) { struct svc_rdma_op_ctxt *ctxt; ctxt = kmalloc(sizeof(*ctxt), flags); if (ctxt) { ctxt->xprt = xprt; INIT_LIST_HEAD(&ctxt->free); INIT_LIST_HEAD(&ctxt->dto_q); } return ctxt; } static bool svc_rdma_prealloc_ctxts(struct svcxprt_rdma *xprt) { int i; /* Each RPC/RDMA credit can consume a number of send * and receive WQEs. One ctxt is allocated for each. */ i = xprt->sc_sq_depth + xprt->sc_max_requests; while (i--) { struct svc_rdma_op_ctxt *ctxt; ctxt = alloc_ctxt(xprt, GFP_KERNEL); if (!ctxt) { dprintk("svcrdma: No memory for RDMA ctxt\n"); return false; } list_add(&ctxt->free, &xprt->sc_ctxts); } return true; } struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt) { struct svc_rdma_op_ctxt *ctxt = NULL; spin_lock_bh(&xprt->sc_ctxt_lock); xprt->sc_ctxt_used++; if (list_empty(&xprt->sc_ctxts)) goto out_empty; ctxt = list_first_entry(&xprt->sc_ctxts, struct svc_rdma_op_ctxt, free); list_del_init(&ctxt->free); spin_unlock_bh(&xprt->sc_ctxt_lock); out: ctxt->count = 0; ctxt->frmr = NULL; return ctxt; out_empty: /* Either pre-allocation missed the mark, or send * queue accounting is broken. */ spin_unlock_bh(&xprt->sc_ctxt_lock); ctxt = alloc_ctxt(xprt, GFP_NOIO); if (ctxt) goto out; spin_lock_bh(&xprt->sc_ctxt_lock); xprt->sc_ctxt_used--; spin_unlock_bh(&xprt->sc_ctxt_lock); WARN_ONCE(1, "svcrdma: empty RDMA ctxt list?\n"); return NULL; } void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt) { struct svcxprt_rdma *xprt = ctxt->xprt; int i; for (i = 0; i < ctxt->count && ctxt->sge[i].length; i++) { /* * Unmap the DMA addr in the SGE if the lkey matches * the sc_dma_lkey, otherwise, ignore it since it is * an FRMR lkey and will be unmapped later when the * last WR that uses it completes. */ if (ctxt->sge[i].lkey == xprt->sc_dma_lkey) { atomic_dec(&xprt->sc_dma_used); ib_dma_unmap_page(xprt->sc_cm_id->device, ctxt->sge[i].addr, ctxt->sge[i].length, ctxt->direction); } } } void svc_rdma_put_context(struct svc_rdma_op_ctxt *ctxt, int free_pages) { struct svcxprt_rdma *xprt = ctxt->xprt; int i; if (free_pages) for (i = 0; i < ctxt->count; i++) put_page(ctxt->pages[i]); spin_lock_bh(&xprt->sc_ctxt_lock); xprt->sc_ctxt_used--; list_add(&ctxt->free, &xprt->sc_ctxts); spin_unlock_bh(&xprt->sc_ctxt_lock); } static void svc_rdma_destroy_ctxts(struct svcxprt_rdma *xprt) { while (!list_empty(&xprt->sc_ctxts)) { struct svc_rdma_op_ctxt *ctxt; ctxt = list_first_entry(&xprt->sc_ctxts, struct svc_rdma_op_ctxt, free); list_del(&ctxt->free); kfree(ctxt); } } static struct svc_rdma_req_map *alloc_req_map(gfp_t flags) { struct svc_rdma_req_map *map; map = kmalloc(sizeof(*map), flags); if (map) INIT_LIST_HEAD(&map->free); return map; } static bool svc_rdma_prealloc_maps(struct svcxprt_rdma *xprt) { int i; /* One for each receive buffer on this connection. */ i = xprt->sc_max_requests; while (i--) { struct svc_rdma_req_map *map; map = alloc_req_map(GFP_KERNEL); if (!map) { dprintk("svcrdma: No memory for request map\n"); return false; } list_add(&map->free, &xprt->sc_maps); } return true; } struct svc_rdma_req_map *svc_rdma_get_req_map(struct svcxprt_rdma *xprt) { struct svc_rdma_req_map *map = NULL; spin_lock(&xprt->sc_map_lock); if (list_empty(&xprt->sc_maps)) goto out_empty; map = list_first_entry(&xprt->sc_maps, struct svc_rdma_req_map, free); list_del_init(&map->free); spin_unlock(&xprt->sc_map_lock); out: map->count = 0; return map; out_empty: spin_unlock(&xprt->sc_map_lock); /* Pre-allocation amount was incorrect */ map = alloc_req_map(GFP_NOIO); if (map) goto out; WARN_ONCE(1, "svcrdma: empty request map list?\n"); return NULL; } void svc_rdma_put_req_map(struct svcxprt_rdma *xprt, struct svc_rdma_req_map *map) { spin_lock(&xprt->sc_map_lock); list_add(&map->free, &xprt->sc_maps); spin_unlock(&xprt->sc_map_lock); } static void svc_rdma_destroy_maps(struct svcxprt_rdma *xprt) { while (!list_empty(&xprt->sc_maps)) { struct svc_rdma_req_map *map; map = list_first_entry(&xprt->sc_maps, struct svc_rdma_req_map, free); list_del(&map->free); kfree(map); } } /* ib_cq event handler */ static void cq_event_handler(struct ib_event *event, void *context) { struct svc_xprt *xprt = context; dprintk("svcrdma: received CQ event %s (%d), context=%p\n", ib_event_msg(event->event), event->event, context); set_bit(XPT_CLOSE, &xprt->xpt_flags); } /* QP event handler */ static void qp_event_handler(struct ib_event *event, void *context) { struct svc_xprt *xprt = context; switch (event->event) { /* These are considered benign events */ case IB_EVENT_PATH_MIG: case IB_EVENT_COMM_EST: case IB_EVENT_SQ_DRAINED: case IB_EVENT_QP_LAST_WQE_REACHED: dprintk("svcrdma: QP event %s (%d) received for QP=%p\n", ib_event_msg(event->event), event->event, event->element.qp); break; /* These are considered fatal events */ case IB_EVENT_PATH_MIG_ERR: case IB_EVENT_QP_FATAL: case IB_EVENT_QP_REQ_ERR: case IB_EVENT_QP_ACCESS_ERR: case IB_EVENT_DEVICE_FATAL: default: dprintk("svcrdma: QP ERROR event %s (%d) received for QP=%p, " "closing transport\n", ib_event_msg(event->event), event->event, event->element.qp); set_bit(XPT_CLOSE, &xprt->xpt_flags); break; } } /* * Data Transfer Operation Tasklet * * Walks a list of transports with I/O pending, removing entries as * they are added to the server's I/O pending list. Two bits indicate * if SQ, RQ, or both have I/O pending. The dto_lock is an irqsave * spinlock that serializes access to the transport list with the RQ * and SQ interrupt handlers. */ static void dto_tasklet_func(unsigned long data) { struct svcxprt_rdma *xprt; unsigned long flags; spin_lock_irqsave(&dto_lock, flags); while (!list_empty(&dto_xprt_q)) { xprt = list_entry(dto_xprt_q.next, struct svcxprt_rdma, sc_dto_q); list_del_init(&xprt->sc_dto_q); spin_unlock_irqrestore(&dto_lock, flags); rq_cq_reap(xprt); sq_cq_reap(xprt); svc_xprt_put(&xprt->sc_xprt); spin_lock_irqsave(&dto_lock, flags); } spin_unlock_irqrestore(&dto_lock, flags); } /* * Receive Queue Completion Handler * * Since an RQ completion handler is called on interrupt context, we * need to defer the handling of the I/O to a tasklet */ static void rq_comp_handler(struct ib_cq *cq, void *cq_context) { struct svcxprt_rdma *xprt = cq_context; unsigned long flags; /* Guard against unconditional flush call for destroyed QP */ if (atomic_read(&xprt->sc_xprt.xpt_ref.refcount)==0) return; /* * Set the bit regardless of whether or not it's on the list * because it may be on the list already due to an SQ * completion. */ set_bit(RDMAXPRT_RQ_PENDING, &xprt->sc_flags); /* * If this transport is not already on the DTO transport queue, * add it */ spin_lock_irqsave(&dto_lock, flags); if (list_empty(&xprt->sc_dto_q)) { svc_xprt_get(&xprt->sc_xprt); list_add_tail(&xprt->sc_dto_q, &dto_xprt_q); } spin_unlock_irqrestore(&dto_lock, flags); /* Tasklet does all the work to avoid irqsave locks. */ tasklet_schedule(&dto_tasklet); } /* * rq_cq_reap - Process the RQ CQ. * * Take all completing WC off the CQE and enqueue the associated DTO * context on the dto_q for the transport. * * Note that caller must hold a transport reference. */ static void rq_cq_reap(struct svcxprt_rdma *xprt) { int ret; struct ib_wc wc; struct svc_rdma_op_ctxt *ctxt = NULL; if (!test_and_clear_bit(RDMAXPRT_RQ_PENDING, &xprt->sc_flags)) return; ib_req_notify_cq(xprt->sc_rq_cq, IB_CQ_NEXT_COMP); atomic_inc(&rdma_stat_rq_poll); while ((ret = ib_poll_cq(xprt->sc_rq_cq, 1, &wc)) > 0) { ctxt = (struct svc_rdma_op_ctxt *)(unsigned long)wc.wr_id; ctxt->wc_status = wc.status; ctxt->byte_len = wc.byte_len; svc_rdma_unmap_dma(ctxt); if (wc.status != IB_WC_SUCCESS) { /* Close the transport */ dprintk("svcrdma: transport closing putting ctxt %p\n", ctxt); set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); svc_rdma_put_context(ctxt, 1); svc_xprt_put(&xprt->sc_xprt); continue; } spin_lock_bh(&xprt->sc_rq_dto_lock); list_add_tail(&ctxt->dto_q, &xprt->sc_rq_dto_q); spin_unlock_bh(&xprt->sc_rq_dto_lock); svc_xprt_put(&xprt->sc_xprt); } if (ctxt) atomic_inc(&rdma_stat_rq_prod); set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags); /* * If data arrived before established event, * don't enqueue. This defers RPC I/O until the * RDMA connection is complete. */ if (!test_bit(RDMAXPRT_CONN_PENDING, &xprt->sc_flags)) svc_xprt_enqueue(&xprt->sc_xprt); } /* * Process a completion context */ static void process_context(struct svcxprt_rdma *xprt, struct svc_rdma_op_ctxt *ctxt) { struct svc_rdma_op_ctxt *read_hdr; int free_pages = 0; svc_rdma_unmap_dma(ctxt); switch (ctxt->wr_op) { case IB_WR_SEND: free_pages = 1; break; case IB_WR_RDMA_WRITE: break; case IB_WR_RDMA_READ: case IB_WR_RDMA_READ_WITH_INV: svc_rdma_put_frmr(xprt, ctxt->frmr); if (!test_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags)) break; read_hdr = ctxt->read_hdr; svc_rdma_put_context(ctxt, 0); spin_lock_bh(&xprt->sc_rq_dto_lock); set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags); list_add_tail(&read_hdr->dto_q, &xprt->sc_read_complete_q); spin_unlock_bh(&xprt->sc_rq_dto_lock); svc_xprt_enqueue(&xprt->sc_xprt); return; default: dprintk("svcrdma: unexpected completion opcode=%d\n", ctxt->wr_op); break; } svc_rdma_put_context(ctxt, free_pages); } /* * Send Queue Completion Handler - potentially called on interrupt context. * * Note that caller must hold a transport reference. */ static void sq_cq_reap(struct svcxprt_rdma *xprt) { struct svc_rdma_op_ctxt *ctxt = NULL; struct ib_wc wc_a[6]; struct ib_wc *wc; struct ib_cq *cq = xprt->sc_sq_cq; int ret; memset(wc_a, 0, sizeof(wc_a)); if (!test_and_clear_bit(RDMAXPRT_SQ_PENDING, &xprt->sc_flags)) return; ib_req_notify_cq(xprt->sc_sq_cq, IB_CQ_NEXT_COMP); atomic_inc(&rdma_stat_sq_poll); while ((ret = ib_poll_cq(cq, ARRAY_SIZE(wc_a), wc_a)) > 0) { int i; for (i = 0; i < ret; i++) { wc = &wc_a[i]; if (wc->status != IB_WC_SUCCESS) { dprintk("svcrdma: sq wc err status %s (%d)\n", ib_wc_status_msg(wc->status), wc->status); /* Close the transport */ set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); } /* Decrement used SQ WR count */ atomic_dec(&xprt->sc_sq_count); wake_up(&xprt->sc_send_wait); ctxt = (struct svc_rdma_op_ctxt *) (unsigned long)wc->wr_id; if (ctxt) process_context(xprt, ctxt); svc_xprt_put(&xprt->sc_xprt); } } if (ctxt) atomic_inc(&rdma_stat_sq_prod); } static void sq_comp_handler(struct ib_cq *cq, void *cq_context) { struct svcxprt_rdma *xprt = cq_context; unsigned long flags; /* Guard against unconditional flush call for destroyed QP */ if (atomic_read(&xprt->sc_xprt.xpt_ref.refcount)==0) return; /* * Set the bit regardless of whether or not it's on the list * because it may be on the list already due to an RQ * completion. */ set_bit(RDMAXPRT_SQ_PENDING, &xprt->sc_flags); /* * If this transport is not already on the DTO transport queue, * add it */ spin_lock_irqsave(&dto_lock, flags); if (list_empty(&xprt->sc_dto_q)) { svc_xprt_get(&xprt->sc_xprt); list_add_tail(&xprt->sc_dto_q, &dto_xprt_q); } spin_unlock_irqrestore(&dto_lock, flags); /* Tasklet does all the work to avoid irqsave locks. */ tasklet_schedule(&dto_tasklet); } static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv, int listener) { struct svcxprt_rdma *cma_xprt = kzalloc(sizeof *cma_xprt, GFP_KERNEL); if (!cma_xprt) return NULL; svc_xprt_init(&init_net, &svc_rdma_class, &cma_xprt->sc_xprt, serv); INIT_LIST_HEAD(&cma_xprt->sc_accept_q); INIT_LIST_HEAD(&cma_xprt->sc_dto_q); INIT_LIST_HEAD(&cma_xprt->sc_rq_dto_q); INIT_LIST_HEAD(&cma_xprt->sc_read_complete_q); INIT_LIST_HEAD(&cma_xprt->sc_frmr_q); INIT_LIST_HEAD(&cma_xprt->sc_ctxts); INIT_LIST_HEAD(&cma_xprt->sc_maps); init_waitqueue_head(&cma_xprt->sc_send_wait); spin_lock_init(&cma_xprt->sc_lock); spin_lock_init(&cma_xprt->sc_rq_dto_lock); spin_lock_init(&cma_xprt->sc_frmr_q_lock); spin_lock_init(&cma_xprt->sc_ctxt_lock); spin_lock_init(&cma_xprt->sc_map_lock); if (listener) set_bit(XPT_LISTENER, &cma_xprt->sc_xprt.xpt_flags); return cma_xprt; } int svc_rdma_post_recv(struct svcxprt_rdma *xprt) { struct ib_recv_wr recv_wr, *bad_recv_wr; struct svc_rdma_op_ctxt *ctxt; struct page *page; dma_addr_t pa; int sge_no; int buflen; int ret; ctxt = svc_rdma_get_context(xprt); buflen = 0; ctxt->direction = DMA_FROM_DEVICE; for (sge_no = 0; buflen < xprt->sc_max_req_size; sge_no++) { if (sge_no >= xprt->sc_max_sge) { pr_err("svcrdma: Too many sges (%d)\n", sge_no); goto err_put_ctxt; } page = alloc_page(GFP_KERNEL | __GFP_NOFAIL); ctxt->pages[sge_no] = page; pa = ib_dma_map_page(xprt->sc_cm_id->device, page, 0, PAGE_SIZE, DMA_FROM_DEVICE); if (ib_dma_mapping_error(xprt->sc_cm_id->device, pa)) goto err_put_ctxt; atomic_inc(&xprt->sc_dma_used); ctxt->sge[sge_no].addr = pa; ctxt->sge[sge_no].length = PAGE_SIZE; ctxt->sge[sge_no].lkey = xprt->sc_dma_lkey; ctxt->count = sge_no + 1; buflen += PAGE_SIZE; } recv_wr.next = NULL; recv_wr.sg_list = &ctxt->sge[0]; recv_wr.num_sge = ctxt->count; recv_wr.wr_id = (u64)(unsigned long)ctxt; svc_xprt_get(&xprt->sc_xprt); ret = ib_post_recv(xprt->sc_qp, &recv_wr, &bad_recv_wr); if (ret) { svc_rdma_unmap_dma(ctxt); svc_rdma_put_context(ctxt, 1); svc_xprt_put(&xprt->sc_xprt); } return ret; err_put_ctxt: svc_rdma_unmap_dma(ctxt); svc_rdma_put_context(ctxt, 1); return -ENOMEM; } /* * This function handles the CONNECT_REQUEST event on a listening * endpoint. It is passed the cma_id for the _new_ connection. The context in * this cma_id is inherited from the listening cma_id and is the svc_xprt * structure for the listening endpoint. * * This function creates a new xprt for the new connection and enqueues it on * the accept queue for the listent xprt. When the listen thread is kicked, it * will call the recvfrom method on the listen xprt which will accept the new * connection. */ static void handle_connect_req(struct rdma_cm_id *new_cma_id, size_t client_ird) { struct svcxprt_rdma *listen_xprt = new_cma_id->context; struct svcxprt_rdma *newxprt; struct sockaddr *sa; /* Create a new transport */ newxprt = rdma_create_xprt(listen_xprt->sc_xprt.xpt_server, 0); if (!newxprt) { dprintk("svcrdma: failed to create new transport\n"); return; } newxprt->sc_cm_id = new_cma_id; new_cma_id->context = newxprt; dprintk("svcrdma: Creating newxprt=%p, cm_id=%p, listenxprt=%p\n", newxprt, newxprt->sc_cm_id, listen_xprt); /* Save client advertised inbound read limit for use later in accept. */ newxprt->sc_ord = client_ird; /* Set the local and remote addresses in the transport */ sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr; svc_xprt_set_remote(&newxprt->sc_xprt, sa, svc_addr_len(sa)); sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr; svc_xprt_set_local(&newxprt->sc_xprt, sa, svc_addr_len(sa)); /* * Enqueue the new transport on the accept queue of the listening * transport */ spin_lock_bh(&listen_xprt->sc_lock); list_add_tail(&newxprt->sc_accept_q, &listen_xprt->sc_accept_q); spin_unlock_bh(&listen_xprt->sc_lock); set_bit(XPT_CONN, &listen_xprt->sc_xprt.xpt_flags); svc_xprt_enqueue(&listen_xprt->sc_xprt); } /* * Handles events generated on the listening endpoint. These events will be * either be incoming connect requests or adapter removal events. */ static int rdma_listen_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event) { struct svcxprt_rdma *xprt = cma_id->context; int ret = 0; switch (event->event) { case RDMA_CM_EVENT_CONNECT_REQUEST: dprintk("svcrdma: Connect request on cma_id=%p, xprt = %p, " "event = %s (%d)\n", cma_id, cma_id->context, rdma_event_msg(event->event), event->event); handle_connect_req(cma_id, event->param.conn.initiator_depth); break; case RDMA_CM_EVENT_ESTABLISHED: /* Accept complete */ dprintk("svcrdma: Connection completed on LISTEN xprt=%p, " "cm_id=%p\n", xprt, cma_id); break; case RDMA_CM_EVENT_DEVICE_REMOVAL: dprintk("svcrdma: Device removal xprt=%p, cm_id=%p\n", xprt, cma_id); if (xprt) set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); break; default: dprintk("svcrdma: Unexpected event on listening endpoint %p, " "event = %s (%d)\n", cma_id, rdma_event_msg(event->event), event->event); break; } return ret; } static int rdma_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event) { struct svc_xprt *xprt = cma_id->context; struct svcxprt_rdma *rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt); switch (event->event) { case RDMA_CM_EVENT_ESTABLISHED: /* Accept complete */ svc_xprt_get(xprt); dprintk("svcrdma: Connection completed on DTO xprt=%p, " "cm_id=%p\n", xprt, cma_id); clear_bit(RDMAXPRT_CONN_PENDING, &rdma->sc_flags); svc_xprt_enqueue(xprt); break; case RDMA_CM_EVENT_DISCONNECTED: dprintk("svcrdma: Disconnect on DTO xprt=%p, cm_id=%p\n", xprt, cma_id); if (xprt) { set_bit(XPT_CLOSE, &xprt->xpt_flags); svc_xprt_enqueue(xprt); svc_xprt_put(xprt); } break; case RDMA_CM_EVENT_DEVICE_REMOVAL: dprintk("svcrdma: Device removal cma_id=%p, xprt = %p, " "event = %s (%d)\n", cma_id, xprt, rdma_event_msg(event->event), event->event); if (xprt) { set_bit(XPT_CLOSE, &xprt->xpt_flags); svc_xprt_enqueue(xprt); svc_xprt_put(xprt); } break; default: dprintk("svcrdma: Unexpected event on DTO endpoint %p, " "event = %s (%d)\n", cma_id, rdma_event_msg(event->event), event->event); break; } return 0; } /* * Create a listening RDMA service endpoint. */ static struct svc_xprt *svc_rdma_create(struct svc_serv *serv, struct net *net, struct sockaddr *sa, int salen, int flags) { struct rdma_cm_id *listen_id; struct svcxprt_rdma *cma_xprt; int ret; dprintk("svcrdma: Creating RDMA socket\n"); if (sa->sa_family != AF_INET) { dprintk("svcrdma: Address family %d is not supported.\n", sa->sa_family); return ERR_PTR(-EAFNOSUPPORT); } cma_xprt = rdma_create_xprt(serv, 1); if (!cma_xprt) return ERR_PTR(-ENOMEM); listen_id = rdma_create_id(&init_net, rdma_listen_handler, cma_xprt, RDMA_PS_TCP, IB_QPT_RC); if (IS_ERR(listen_id)) { ret = PTR_ERR(listen_id); dprintk("svcrdma: rdma_create_id failed = %d\n", ret); goto err0; } ret = rdma_bind_addr(listen_id, sa); if (ret) { dprintk("svcrdma: rdma_bind_addr failed = %d\n", ret); goto err1; } cma_xprt->sc_cm_id = listen_id; ret = rdma_listen(listen_id, RPCRDMA_LISTEN_BACKLOG); if (ret) { dprintk("svcrdma: rdma_listen failed = %d\n", ret); goto err1; } /* * We need to use the address from the cm_id in case the * caller specified 0 for the port number. */ sa = (struct sockaddr *)&cma_xprt->sc_cm_id->route.addr.src_addr; svc_xprt_set_local(&cma_xprt->sc_xprt, sa, salen); return &cma_xprt->sc_xprt; err1: rdma_destroy_id(listen_id); err0: kfree(cma_xprt); return ERR_PTR(ret); } static struct svc_rdma_fastreg_mr *rdma_alloc_frmr(struct svcxprt_rdma *xprt) { struct ib_mr *mr; struct scatterlist *sg; struct svc_rdma_fastreg_mr *frmr; u32 num_sg; frmr = kmalloc(sizeof(*frmr), GFP_KERNEL); if (!frmr) goto err; num_sg = min_t(u32, RPCSVC_MAXPAGES, xprt->sc_frmr_pg_list_len); mr = ib_alloc_mr(xprt->sc_pd, IB_MR_TYPE_MEM_REG, num_sg); if (IS_ERR(mr)) goto err_free_frmr; sg = kcalloc(RPCSVC_MAXPAGES, sizeof(*sg), GFP_KERNEL); if (!sg) goto err_free_mr; sg_init_table(sg, RPCSVC_MAXPAGES); frmr->mr = mr; frmr->sg = sg; INIT_LIST_HEAD(&frmr->frmr_list); return frmr; err_free_mr: ib_dereg_mr(mr); err_free_frmr: kfree(frmr); err: return ERR_PTR(-ENOMEM); } static void rdma_dealloc_frmr_q(struct svcxprt_rdma *xprt) { struct svc_rdma_fastreg_mr *frmr; while (!list_empty(&xprt->sc_frmr_q)) { frmr = list_entry(xprt->sc_frmr_q.next, struct svc_rdma_fastreg_mr, frmr_list); list_del_init(&frmr->frmr_list); kfree(frmr->sg); ib_dereg_mr(frmr->mr); kfree(frmr); } } struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *rdma) { struct svc_rdma_fastreg_mr *frmr = NULL; spin_lock_bh(&rdma->sc_frmr_q_lock); if (!list_empty(&rdma->sc_frmr_q)) { frmr = list_entry(rdma->sc_frmr_q.next, struct svc_rdma_fastreg_mr, frmr_list); list_del_init(&frmr->frmr_list); frmr->sg_nents = 0; } spin_unlock_bh(&rdma->sc_frmr_q_lock); if (frmr) return frmr; return rdma_alloc_frmr(rdma); } void svc_rdma_put_frmr(struct svcxprt_rdma *rdma, struct svc_rdma_fastreg_mr *frmr) { if (frmr) { ib_dma_unmap_sg(rdma->sc_cm_id->device, frmr->sg, frmr->sg_nents, frmr->direction); atomic_dec(&rdma->sc_dma_used); spin_lock_bh(&rdma->sc_frmr_q_lock); WARN_ON_ONCE(!list_empty(&frmr->frmr_list)); list_add(&frmr->frmr_list, &rdma->sc_frmr_q); spin_unlock_bh(&rdma->sc_frmr_q_lock); } } /* * This is the xpo_recvfrom function for listening endpoints. Its * purpose is to accept incoming connections. The CMA callback handler * has already created a new transport and attached it to the new CMA * ID. * * There is a queue of pending connections hung on the listening * transport. This queue contains the new svc_xprt structure. This * function takes svc_xprt structures off the accept_q and completes * the connection. */ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) { struct svcxprt_rdma *listen_rdma; struct svcxprt_rdma *newxprt = NULL; struct rdma_conn_param conn_param; struct ib_cq_init_attr cq_attr = {}; struct ib_qp_init_attr qp_attr; struct ib_device *dev; int uninitialized_var(dma_mr_acc); int need_dma_mr = 0; int ret = 0; int i; listen_rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt); clear_bit(XPT_CONN, &xprt->xpt_flags); /* Get the next entry off the accept list */ spin_lock_bh(&listen_rdma->sc_lock); if (!list_empty(&listen_rdma->sc_accept_q)) { newxprt = list_entry(listen_rdma->sc_accept_q.next, struct svcxprt_rdma, sc_accept_q); list_del_init(&newxprt->sc_accept_q); } if (!list_empty(&listen_rdma->sc_accept_q)) set_bit(XPT_CONN, &listen_rdma->sc_xprt.xpt_flags); spin_unlock_bh(&listen_rdma->sc_lock); if (!newxprt) return NULL; dprintk("svcrdma: newxprt from accept queue = %p, cm_id=%p\n", newxprt, newxprt->sc_cm_id); dev = newxprt->sc_cm_id->device; /* Qualify the transport resource defaults with the * capabilities of this particular device */ newxprt->sc_max_sge = min((size_t)dev->attrs.max_sge, (size_t)RPCSVC_MAXPAGES); newxprt->sc_max_sge_rd = min_t(size_t, dev->attrs.max_sge_rd, RPCSVC_MAXPAGES); newxprt->sc_max_req_size = svcrdma_max_req_size; newxprt->sc_max_requests = min((size_t)dev->attrs.max_qp_wr, (size_t)svcrdma_max_requests); newxprt->sc_sq_depth = RPCRDMA_SQ_DEPTH_MULT * newxprt->sc_max_requests; if (!svc_rdma_prealloc_ctxts(newxprt)) goto errout; if (!svc_rdma_prealloc_maps(newxprt)) goto errout; /* * Limit ORD based on client limit, local device limit, and * configured svcrdma limit. */ newxprt->sc_ord = min_t(size_t, dev->attrs.max_qp_rd_atom, newxprt->sc_ord); newxprt->sc_ord = min_t(size_t, svcrdma_ord, newxprt->sc_ord); newxprt->sc_pd = ib_alloc_pd(dev); if (IS_ERR(newxprt->sc_pd)) { dprintk("svcrdma: error creating PD for connect request\n"); goto errout; } cq_attr.cqe = newxprt->sc_sq_depth; newxprt->sc_sq_cq = ib_create_cq(dev, sq_comp_handler, cq_event_handler, newxprt, &cq_attr); if (IS_ERR(newxprt->sc_sq_cq)) { dprintk("svcrdma: error creating SQ CQ for connect request\n"); goto errout; } cq_attr.cqe = newxprt->sc_max_requests; newxprt->sc_rq_cq = ib_create_cq(dev, rq_comp_handler, cq_event_handler, newxprt, &cq_attr); if (IS_ERR(newxprt->sc_rq_cq)) { dprintk("svcrdma: error creating RQ CQ for connect request\n"); goto errout; } memset(&qp_attr, 0, sizeof qp_attr); qp_attr.event_handler = qp_event_handler; qp_attr.qp_context = &newxprt->sc_xprt; qp_attr.cap.max_send_wr = newxprt->sc_sq_depth; qp_attr.cap.max_recv_wr = newxprt->sc_max_requests; qp_attr.cap.max_send_sge = newxprt->sc_max_sge; qp_attr.cap.max_recv_sge = newxprt->sc_max_sge; qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR; qp_attr.qp_type = IB_QPT_RC; qp_attr.send_cq = newxprt->sc_sq_cq; qp_attr.recv_cq = newxprt->sc_rq_cq; dprintk("svcrdma: newxprt->sc_cm_id=%p, newxprt->sc_pd=%p\n" " cm_id->device=%p, sc_pd->device=%p\n" " cap.max_send_wr = %d\n" " cap.max_recv_wr = %d\n" " cap.max_send_sge = %d\n" " cap.max_recv_sge = %d\n", newxprt->sc_cm_id, newxprt->sc_pd, dev, newxprt->sc_pd->device, qp_attr.cap.max_send_wr, qp_attr.cap.max_recv_wr, qp_attr.cap.max_send_sge, qp_attr.cap.max_recv_sge); ret = rdma_create_qp(newxprt->sc_cm_id, newxprt->sc_pd, &qp_attr); if (ret) { dprintk("svcrdma: failed to create QP, ret=%d\n", ret); goto errout; } newxprt->sc_qp = newxprt->sc_cm_id->qp; /* * Use the most secure set of MR resources based on the * transport type and available memory management features in * the device. Here's the table implemented below: * * Fast Global DMA Remote WR * Reg LKEY MR Access * Sup'd Sup'd Needed Needed * * IWARP N N Y Y * N Y Y Y * Y N Y N * Y Y N - * * IB N N Y N * N Y N - * Y N Y N * Y Y N - * * NB: iWARP requires remote write access for the data sink * of an RDMA_READ. IB does not. */ newxprt->sc_reader = rdma_read_chunk_lcl; if (dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) { newxprt->sc_frmr_pg_list_len = dev->attrs.max_fast_reg_page_list_len; newxprt->sc_dev_caps |= SVCRDMA_DEVCAP_FAST_REG; newxprt->sc_reader = rdma_read_chunk_frmr; } /* * Determine if a DMA MR is required and if so, what privs are required */ if (!rdma_protocol_iwarp(dev, newxprt->sc_cm_id->port_num) && !rdma_ib_or_roce(dev, newxprt->sc_cm_id->port_num)) goto errout; if (!(newxprt->sc_dev_caps & SVCRDMA_DEVCAP_FAST_REG) || !(dev->attrs.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)) { need_dma_mr = 1; dma_mr_acc = IB_ACCESS_LOCAL_WRITE; if (rdma_protocol_iwarp(dev, newxprt->sc_cm_id->port_num) && !(newxprt->sc_dev_caps & SVCRDMA_DEVCAP_FAST_REG)) dma_mr_acc |= IB_ACCESS_REMOTE_WRITE; } if (rdma_protocol_iwarp(dev, newxprt->sc_cm_id->port_num)) newxprt->sc_dev_caps |= SVCRDMA_DEVCAP_READ_W_INV; /* Create the DMA MR if needed, otherwise, use the DMA LKEY */ if (need_dma_mr) { /* Register all of physical memory */ newxprt->sc_phys_mr = ib_get_dma_mr(newxprt->sc_pd, dma_mr_acc); if (IS_ERR(newxprt->sc_phys_mr)) { dprintk("svcrdma: Failed to create DMA MR ret=%d\n", ret); goto errout; } newxprt->sc_dma_lkey = newxprt->sc_phys_mr->lkey; } else newxprt->sc_dma_lkey = dev->local_dma_lkey; /* Post receive buffers */ for (i = 0; i < newxprt->sc_max_requests; i++) { ret = svc_rdma_post_recv(newxprt); if (ret) { dprintk("svcrdma: failure posting receive buffers\n"); goto errout; } } /* Swap out the handler */ newxprt->sc_cm_id->event_handler = rdma_cma_handler; /* * Arm the CQs for the SQ and RQ before accepting so we can't * miss the first message */ ib_req_notify_cq(newxprt->sc_sq_cq, IB_CQ_NEXT_COMP); ib_req_notify_cq(newxprt->sc_rq_cq, IB_CQ_NEXT_COMP); /* Accept Connection */ set_bit(RDMAXPRT_CONN_PENDING, &newxprt->sc_flags); memset(&conn_param, 0, sizeof conn_param); conn_param.responder_resources = 0; conn_param.initiator_depth = newxprt->sc_ord; ret = rdma_accept(newxprt->sc_cm_id, &conn_param); if (ret) { dprintk("svcrdma: failed to accept new connection, ret=%d\n", ret); goto errout; } dprintk("svcrdma: new connection %p accepted with the following " "attributes:\n" " local_ip : %pI4\n" " local_port : %d\n" " remote_ip : %pI4\n" " remote_port : %d\n" " max_sge : %d\n" " max_sge_rd : %d\n" " sq_depth : %d\n" " max_requests : %d\n" " ord : %d\n", newxprt, &((struct sockaddr_in *)&newxprt->sc_cm_id-> route.addr.src_addr)->sin_addr.s_addr, ntohs(((struct sockaddr_in *)&newxprt->sc_cm_id-> route.addr.src_addr)->sin_port), &((struct sockaddr_in *)&newxprt->sc_cm_id-> route.addr.dst_addr)->sin_addr.s_addr, ntohs(((struct sockaddr_in *)&newxprt->sc_cm_id-> route.addr.dst_addr)->sin_port), newxprt->sc_max_sge, newxprt->sc_max_sge_rd, newxprt->sc_sq_depth, newxprt->sc_max_requests, newxprt->sc_ord); return &newxprt->sc_xprt; errout: dprintk("svcrdma: failure accepting new connection rc=%d.\n", ret); /* Take a reference in case the DTO handler runs */ svc_xprt_get(&newxprt->sc_xprt); if (newxprt->sc_qp && !IS_ERR(newxprt->sc_qp)) ib_destroy_qp(newxprt->sc_qp); rdma_destroy_id(newxprt->sc_cm_id); /* This call to put will destroy the transport */ svc_xprt_put(&newxprt->sc_xprt); return NULL; } static void svc_rdma_release_rqst(struct svc_rqst *rqstp) { } /* * When connected, an svc_xprt has at least two references: * * - A reference held by the cm_id between the ESTABLISHED and * DISCONNECTED events. If the remote peer disconnected first, this * reference could be gone. * * - A reference held by the svc_recv code that called this function * as part of close processing. * * At a minimum one references should still be held. */ static void svc_rdma_detach(struct svc_xprt *xprt) { struct svcxprt_rdma *rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt); dprintk("svc: svc_rdma_detach(%p)\n", xprt); /* Disconnect and flush posted WQE */ rdma_disconnect(rdma->sc_cm_id); } static void __svc_rdma_free(struct work_struct *work) { struct svcxprt_rdma *rdma = container_of(work, struct svcxprt_rdma, sc_work); dprintk("svcrdma: svc_rdma_free(%p)\n", rdma); /* We should only be called from kref_put */ if (atomic_read(&rdma->sc_xprt.xpt_ref.refcount) != 0) pr_err("svcrdma: sc_xprt still in use? (%d)\n", atomic_read(&rdma->sc_xprt.xpt_ref.refcount)); /* * Destroy queued, but not processed read completions. Note * that this cleanup has to be done before destroying the * cm_id because the device ptr is needed to unmap the dma in * svc_rdma_put_context. */ while (!list_empty(&rdma->sc_read_complete_q)) { struct svc_rdma_op_ctxt *ctxt; ctxt = list_entry(rdma->sc_read_complete_q.next, struct svc_rdma_op_ctxt, dto_q); list_del_init(&ctxt->dto_q); svc_rdma_put_context(ctxt, 1); } /* Destroy queued, but not processed recv completions */ while (!list_empty(&rdma->sc_rq_dto_q)) { struct svc_rdma_op_ctxt *ctxt; ctxt = list_entry(rdma->sc_rq_dto_q.next, struct svc_rdma_op_ctxt, dto_q); list_del_init(&ctxt->dto_q); svc_rdma_put_context(ctxt, 1); } /* Warn if we leaked a resource or under-referenced */ if (rdma->sc_ctxt_used != 0) pr_err("svcrdma: ctxt still in use? (%d)\n", rdma->sc_ctxt_used); if (atomic_read(&rdma->sc_dma_used) != 0) pr_err("svcrdma: dma still in use? (%d)\n", atomic_read(&rdma->sc_dma_used)); rdma_dealloc_frmr_q(rdma); svc_rdma_destroy_ctxts(rdma); svc_rdma_destroy_maps(rdma); /* Destroy the QP if present (not a listener) */ if (rdma->sc_qp && !IS_ERR(rdma->sc_qp)) ib_destroy_qp(rdma->sc_qp); if (rdma->sc_sq_cq && !IS_ERR(rdma->sc_sq_cq)) ib_destroy_cq(rdma->sc_sq_cq); if (rdma->sc_rq_cq && !IS_ERR(rdma->sc_rq_cq)) ib_destroy_cq(rdma->sc_rq_cq); if (rdma->sc_phys_mr && !IS_ERR(rdma->sc_phys_mr)) ib_dereg_mr(rdma->sc_phys_mr); if (rdma->sc_pd && !IS_ERR(rdma->sc_pd)) ib_dealloc_pd(rdma->sc_pd); /* Destroy the CM ID */ rdma_destroy_id(rdma->sc_cm_id); kfree(rdma); } static void svc_rdma_free(struct svc_xprt *xprt) { struct svcxprt_rdma *rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt); INIT_WORK(&rdma->sc_work, __svc_rdma_free); queue_work(svc_rdma_wq, &rdma->sc_work); } static int svc_rdma_has_wspace(struct svc_xprt *xprt) { struct svcxprt_rdma *rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt); /* * If there are already waiters on the SQ, * return false. */ if (waitqueue_active(&rdma->sc_send_wait)) return 0; /* Otherwise return true. */ return 1; } static int svc_rdma_secure_port(struct svc_rqst *rqstp) { return 1; } int svc_rdma_send(struct svcxprt_rdma *xprt, struct ib_send_wr *wr) { struct ib_send_wr *bad_wr, *n_wr; int wr_count; int i; int ret; if (test_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags)) return -ENOTCONN; wr_count = 1; for (n_wr = wr->next; n_wr; n_wr = n_wr->next) wr_count++; /* If the SQ is full, wait until an SQ entry is available */ while (1) { spin_lock_bh(&xprt->sc_lock); if (xprt->sc_sq_depth < atomic_read(&xprt->sc_sq_count) + wr_count) { spin_unlock_bh(&xprt->sc_lock); atomic_inc(&rdma_stat_sq_starve); /* See if we can opportunistically reap SQ WR to make room */ sq_cq_reap(xprt); /* Wait until SQ WR available if SQ still full */ wait_event(xprt->sc_send_wait, atomic_read(&xprt->sc_sq_count) < xprt->sc_sq_depth); if (test_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags)) return -ENOTCONN; continue; } /* Take a transport ref for each WR posted */ for (i = 0; i < wr_count; i++) svc_xprt_get(&xprt->sc_xprt); /* Bump used SQ WR count and post */ atomic_add(wr_count, &xprt->sc_sq_count); ret = ib_post_send(xprt->sc_qp, wr, &bad_wr); if (ret) { set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); atomic_sub(wr_count, &xprt->sc_sq_count); for (i = 0; i < wr_count; i ++) svc_xprt_put(&xprt->sc_xprt); dprintk("svcrdma: failed to post SQ WR rc=%d, " "sc_sq_count=%d, sc_sq_depth=%d\n", ret, atomic_read(&xprt->sc_sq_count), xprt->sc_sq_depth); } spin_unlock_bh(&xprt->sc_lock); if (ret) wake_up(&xprt->sc_send_wait); break; } return ret; } void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp, enum rpcrdma_errcode err) { struct ib_send_wr err_wr; struct page *p; struct svc_rdma_op_ctxt *ctxt; __be32 *va; int length; int ret; p = alloc_page(GFP_KERNEL | __GFP_NOFAIL); va = page_address(p); /* XDR encode error */ length = svc_rdma_xdr_encode_error(xprt, rmsgp, err, va); ctxt = svc_rdma_get_context(xprt); ctxt->direction = DMA_FROM_DEVICE; ctxt->count = 1; ctxt->pages[0] = p; /* Prepare SGE for local address */ ctxt->sge[0].addr = ib_dma_map_page(xprt->sc_cm_id->device, p, 0, length, DMA_FROM_DEVICE); if (ib_dma_mapping_error(xprt->sc_cm_id->device, ctxt->sge[0].addr)) { put_page(p); svc_rdma_put_context(ctxt, 1); return; } atomic_inc(&xprt->sc_dma_used); ctxt->sge[0].lkey = xprt->sc_dma_lkey; ctxt->sge[0].length = length; /* Prepare SEND WR */ memset(&err_wr, 0, sizeof err_wr); ctxt->wr_op = IB_WR_SEND; err_wr.wr_id = (unsigned long)ctxt; err_wr.sg_list = ctxt->sge; err_wr.num_sge = 1; err_wr.opcode = IB_WR_SEND; err_wr.send_flags = IB_SEND_SIGNALED; /* Post It */ ret = svc_rdma_send(xprt, &err_wr); if (ret) { dprintk("svcrdma: Error %d posting send for protocol error\n", ret); svc_rdma_unmap_dma(ctxt); svc_rdma_put_context(ctxt, 1); } }