// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause /* * Copyright (c) 2014-2017 Oracle. All rights reserved. * Copyright (c) 2003-2007 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. */ /* * verbs.c * * Encapsulates the major functions managing: * o adapters * o endpoints * o connections * o buffer memory */ #include #include #include #include #include #include #include #include #include "xprt_rdma.h" #include /* * Globals/Macros */ #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) # define RPCDBG_FACILITY RPCDBG_TRANS #endif /* * internal functions */ static int rpcrdma_sendctxs_create(struct rpcrdma_xprt *r_xprt); static void rpcrdma_sendctxs_destroy(struct rpcrdma_xprt *r_xprt); static void rpcrdma_sendctx_put_locked(struct rpcrdma_xprt *r_xprt, struct rpcrdma_sendctx *sc); static int rpcrdma_reqs_setup(struct rpcrdma_xprt *r_xprt); static void rpcrdma_reqs_reset(struct rpcrdma_xprt *r_xprt); static void rpcrdma_rep_put(struct rpcrdma_buffer *buf, struct rpcrdma_rep *rep); static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep); static void rpcrdma_reps_unmap(struct rpcrdma_xprt *r_xprt); static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt); static void rpcrdma_mrs_destroy(struct rpcrdma_xprt *r_xprt); static void rpcrdma_ep_get(struct rpcrdma_ep *ep); static int rpcrdma_ep_put(struct rpcrdma_ep *ep); static struct rpcrdma_regbuf * rpcrdma_regbuf_alloc(size_t size, enum dma_data_direction direction, gfp_t flags); static void rpcrdma_regbuf_dma_unmap(struct rpcrdma_regbuf *rb); static void rpcrdma_regbuf_free(struct rpcrdma_regbuf *rb); /* Wait for outstanding transport work to finish. ib_drain_qp * handles the drains in the wrong order for us, so open code * them here. */ static void rpcrdma_xprt_drain(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_ep *ep = r_xprt->rx_ep; struct rdma_cm_id *id = ep->re_id; /* Wait for rpcrdma_post_recvs() to leave its critical * section. */ if (atomic_inc_return(&ep->re_receiving) > 1) wait_for_completion(&ep->re_done); /* Flush Receives, then wait for deferred Reply work * to complete. */ ib_drain_rq(id->qp); /* Deferred Reply processing might have scheduled * local invalidations. */ ib_drain_sq(id->qp); rpcrdma_ep_put(ep); } /** * rpcrdma_qp_event_handler - Handle one QP event (error notification) * @event: details of the event * @context: ep that owns QP where event occurred * * Called from the RDMA provider (device driver) possibly in an interrupt * context. The QP is always destroyed before the ID, so the ID will be * reliably available when this handler is invoked. */ static void rpcrdma_qp_event_handler(struct ib_event *event, void *context) { struct rpcrdma_ep *ep = context; trace_xprtrdma_qp_event(ep, event); } /* Ensure xprt_force_disconnect() is invoked exactly once when a * connection is closed or lost. (The important thing is it needs * to be invoked "at least" once). */ static void rpcrdma_force_disconnect(struct rpcrdma_ep *ep) { if (atomic_add_unless(&ep->re_force_disconnect, 1, 1)) xprt_force_disconnect(ep->re_xprt); } /** * rpcrdma_flush_disconnect - Disconnect on flushed completion * @r_xprt: transport to disconnect * @wc: work completion entry * * Must be called in process context. */ void rpcrdma_flush_disconnect(struct rpcrdma_xprt *r_xprt, struct ib_wc *wc) { if (wc->status != IB_WC_SUCCESS) rpcrdma_force_disconnect(r_xprt->rx_ep); } /** * rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC * @cq: completion queue * @wc: WCE for a completed Send WR * */ static void rpcrdma_wc_send(struct ib_cq *cq, struct ib_wc *wc) { struct ib_cqe *cqe = wc->wr_cqe; struct rpcrdma_sendctx *sc = container_of(cqe, struct rpcrdma_sendctx, sc_cqe); struct rpcrdma_xprt *r_xprt = cq->cq_context; /* WARNING: Only wr_cqe and status are reliable at this point */ trace_xprtrdma_wc_send(wc, &sc->sc_cid); rpcrdma_sendctx_put_locked(r_xprt, sc); rpcrdma_flush_disconnect(r_xprt, wc); } /** * rpcrdma_wc_receive - Invoked by RDMA provider for each polled Receive WC * @cq: completion queue * @wc: WCE for a completed Receive WR * */ static void rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc) { struct ib_cqe *cqe = wc->wr_cqe; struct rpcrdma_rep *rep = container_of(cqe, struct rpcrdma_rep, rr_cqe); struct rpcrdma_xprt *r_xprt = cq->cq_context; /* WARNING: Only wr_cqe and status are reliable at this point */ trace_xprtrdma_wc_receive(wc, &rep->rr_cid); --r_xprt->rx_ep->re_receive_count; if (wc->status != IB_WC_SUCCESS) goto out_flushed; /* status == SUCCESS means all fields in wc are trustworthy */ rpcrdma_set_xdrlen(&rep->rr_hdrbuf, wc->byte_len); rep->rr_wc_flags = wc->wc_flags; rep->rr_inv_rkey = wc->ex.invalidate_rkey; ib_dma_sync_single_for_cpu(rdmab_device(rep->rr_rdmabuf), rdmab_addr(rep->rr_rdmabuf), wc->byte_len, DMA_FROM_DEVICE); rpcrdma_reply_handler(rep); return; out_flushed: rpcrdma_flush_disconnect(r_xprt, wc); rpcrdma_rep_put(&r_xprt->rx_buf, rep); } static void rpcrdma_update_cm_private(struct rpcrdma_ep *ep, struct rdma_conn_param *param) { const struct rpcrdma_connect_private *pmsg = param->private_data; unsigned int rsize, wsize; /* Default settings for RPC-over-RDMA Version One */ ep->re_implicit_roundup = xprt_rdma_pad_optimize; rsize = RPCRDMA_V1_DEF_INLINE_SIZE; wsize = RPCRDMA_V1_DEF_INLINE_SIZE; if (pmsg && pmsg->cp_magic == rpcrdma_cmp_magic && pmsg->cp_version == RPCRDMA_CMP_VERSION) { ep->re_implicit_roundup = true; rsize = rpcrdma_decode_buffer_size(pmsg->cp_send_size); wsize = rpcrdma_decode_buffer_size(pmsg->cp_recv_size); } if (rsize < ep->re_inline_recv) ep->re_inline_recv = rsize; if (wsize < ep->re_inline_send) ep->re_inline_send = wsize; rpcrdma_set_max_header_sizes(ep); } /** * rpcrdma_cm_event_handler - Handle RDMA CM events * @id: rdma_cm_id on which an event has occurred * @event: details of the event * * Called with @id's mutex held. Returns 1 if caller should * destroy @id, otherwise 0. */ static int rpcrdma_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event) { struct sockaddr *sap = (struct sockaddr *)&id->route.addr.dst_addr; struct rpcrdma_ep *ep = id->context; might_sleep(); switch (event->event) { case RDMA_CM_EVENT_ADDR_RESOLVED: case RDMA_CM_EVENT_ROUTE_RESOLVED: ep->re_async_rc = 0; complete(&ep->re_done); return 0; case RDMA_CM_EVENT_ADDR_ERROR: ep->re_async_rc = -EPROTO; complete(&ep->re_done); return 0; case RDMA_CM_EVENT_ROUTE_ERROR: ep->re_async_rc = -ENETUNREACH; complete(&ep->re_done); return 0; case RDMA_CM_EVENT_DEVICE_REMOVAL: pr_info("rpcrdma: removing device %s for %pISpc\n", ep->re_id->device->name, sap); fallthrough; case RDMA_CM_EVENT_ADDR_CHANGE: ep->re_connect_status = -ENODEV; goto disconnected; case RDMA_CM_EVENT_ESTABLISHED: rpcrdma_ep_get(ep); ep->re_connect_status = 1; rpcrdma_update_cm_private(ep, &event->param.conn); trace_xprtrdma_inline_thresh(ep); wake_up_all(&ep->re_connect_wait); break; case RDMA_CM_EVENT_CONNECT_ERROR: ep->re_connect_status = -ENOTCONN; goto wake_connect_worker; case RDMA_CM_EVENT_UNREACHABLE: ep->re_connect_status = -ENETUNREACH; goto wake_connect_worker; case RDMA_CM_EVENT_REJECTED: dprintk("rpcrdma: connection to %pISpc rejected: %s\n", sap, rdma_reject_msg(id, event->status)); ep->re_connect_status = -ECONNREFUSED; if (event->status == IB_CM_REJ_STALE_CONN) ep->re_connect_status = -ENOTCONN; wake_connect_worker: wake_up_all(&ep->re_connect_wait); return 0; case RDMA_CM_EVENT_DISCONNECTED: ep->re_connect_status = -ECONNABORTED; disconnected: rpcrdma_force_disconnect(ep); return rpcrdma_ep_put(ep); default: break; } dprintk("RPC: %s: %pISpc on %s/frwr: %s\n", __func__, sap, ep->re_id->device->name, rdma_event_msg(event->event)); return 0; } static struct rdma_cm_id *rpcrdma_create_id(struct rpcrdma_xprt *r_xprt, struct rpcrdma_ep *ep) { unsigned long wtimeout = msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1; struct rpc_xprt *xprt = &r_xprt->rx_xprt; struct rdma_cm_id *id; int rc; init_completion(&ep->re_done); id = rdma_create_id(xprt->xprt_net, rpcrdma_cm_event_handler, ep, RDMA_PS_TCP, IB_QPT_RC); if (IS_ERR(id)) return id; ep->re_async_rc = -ETIMEDOUT; rc = rdma_resolve_addr(id, NULL, (struct sockaddr *)&xprt->addr, RDMA_RESOLVE_TIMEOUT); if (rc) goto out; rc = wait_for_completion_interruptible_timeout(&ep->re_done, wtimeout); if (rc < 0) goto out; rc = ep->re_async_rc; if (rc) goto out; ep->re_async_rc = -ETIMEDOUT; rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT); if (rc) goto out; rc = wait_for_completion_interruptible_timeout(&ep->re_done, wtimeout); if (rc < 0) goto out; rc = ep->re_async_rc; if (rc) goto out; return id; out: rdma_destroy_id(id); return ERR_PTR(rc); } static void rpcrdma_ep_destroy(struct kref *kref) { struct rpcrdma_ep *ep = container_of(kref, struct rpcrdma_ep, re_kref); if (ep->re_id->qp) { rdma_destroy_qp(ep->re_id); ep->re_id->qp = NULL; } if (ep->re_attr.recv_cq) ib_free_cq(ep->re_attr.recv_cq); ep->re_attr.recv_cq = NULL; if (ep->re_attr.send_cq) ib_free_cq(ep->re_attr.send_cq); ep->re_attr.send_cq = NULL; if (ep->re_pd) ib_dealloc_pd(ep->re_pd); ep->re_pd = NULL; kfree(ep); module_put(THIS_MODULE); } static noinline void rpcrdma_ep_get(struct rpcrdma_ep *ep) { kref_get(&ep->re_kref); } /* Returns: * %0 if @ep still has a positive kref count, or * %1 if @ep was destroyed successfully. */ static noinline int rpcrdma_ep_put(struct rpcrdma_ep *ep) { return kref_put(&ep->re_kref, rpcrdma_ep_destroy); } static int rpcrdma_ep_create(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_connect_private *pmsg; struct ib_device *device; struct rdma_cm_id *id; struct rpcrdma_ep *ep; int rc; ep = kzalloc(sizeof(*ep), GFP_NOFS); if (!ep) return -ENOTCONN; ep->re_xprt = &r_xprt->rx_xprt; kref_init(&ep->re_kref); id = rpcrdma_create_id(r_xprt, ep); if (IS_ERR(id)) { kfree(ep); return PTR_ERR(id); } __module_get(THIS_MODULE); device = id->device; ep->re_id = id; reinit_completion(&ep->re_done); ep->re_max_requests = r_xprt->rx_xprt.max_reqs; ep->re_inline_send = xprt_rdma_max_inline_write; ep->re_inline_recv = xprt_rdma_max_inline_read; rc = frwr_query_device(ep, device); if (rc) goto out_destroy; r_xprt->rx_buf.rb_max_requests = cpu_to_be32(ep->re_max_requests); ep->re_attr.event_handler = rpcrdma_qp_event_handler; ep->re_attr.qp_context = ep; ep->re_attr.srq = NULL; ep->re_attr.cap.max_inline_data = 0; ep->re_attr.sq_sig_type = IB_SIGNAL_REQ_WR; ep->re_attr.qp_type = IB_QPT_RC; ep->re_attr.port_num = ~0; dprintk("RPC: %s: requested max: dtos: send %d recv %d; " "iovs: send %d recv %d\n", __func__, ep->re_attr.cap.max_send_wr, ep->re_attr.cap.max_recv_wr, ep->re_attr.cap.max_send_sge, ep->re_attr.cap.max_recv_sge); ep->re_send_batch = ep->re_max_requests >> 3; ep->re_send_count = ep->re_send_batch; init_waitqueue_head(&ep->re_connect_wait); ep->re_attr.send_cq = ib_alloc_cq_any(device, r_xprt, ep->re_attr.cap.max_send_wr, IB_POLL_WORKQUEUE); if (IS_ERR(ep->re_attr.send_cq)) { rc = PTR_ERR(ep->re_attr.send_cq); goto out_destroy; } ep->re_attr.recv_cq = ib_alloc_cq_any(device, r_xprt, ep->re_attr.cap.max_recv_wr, IB_POLL_WORKQUEUE); if (IS_ERR(ep->re_attr.recv_cq)) { rc = PTR_ERR(ep->re_attr.recv_cq); goto out_destroy; } ep->re_receive_count = 0; /* Initialize cma parameters */ memset(&ep->re_remote_cma, 0, sizeof(ep->re_remote_cma)); /* Prepare RDMA-CM private message */ pmsg = &ep->re_cm_private; pmsg->cp_magic = rpcrdma_cmp_magic; pmsg->cp_version = RPCRDMA_CMP_VERSION; pmsg->cp_flags |= RPCRDMA_CMP_F_SND_W_INV_OK; pmsg->cp_send_size = rpcrdma_encode_buffer_size(ep->re_inline_send); pmsg->cp_recv_size = rpcrdma_encode_buffer_size(ep->re_inline_recv); ep->re_remote_cma.private_data = pmsg; ep->re_remote_cma.private_data_len = sizeof(*pmsg); /* Client offers RDMA Read but does not initiate */ ep->re_remote_cma.initiator_depth = 0; ep->re_remote_cma.responder_resources = min_t(int, U8_MAX, device->attrs.max_qp_rd_atom); /* Limit transport retries so client can detect server * GID changes quickly. RPC layer handles re-establishing * transport connection and retransmission. */ ep->re_remote_cma.retry_count = 6; /* RPC-over-RDMA handles its own flow control. In addition, * make all RNR NAKs visible so we know that RPC-over-RDMA * flow control is working correctly (no NAKs should be seen). */ ep->re_remote_cma.flow_control = 0; ep->re_remote_cma.rnr_retry_count = 0; ep->re_pd = ib_alloc_pd(device, 0); if (IS_ERR(ep->re_pd)) { rc = PTR_ERR(ep->re_pd); goto out_destroy; } rc = rdma_create_qp(id, ep->re_pd, &ep->re_attr); if (rc) goto out_destroy; r_xprt->rx_ep = ep; return 0; out_destroy: rpcrdma_ep_put(ep); rdma_destroy_id(id); return rc; } /** * rpcrdma_xprt_connect - Connect an unconnected transport * @r_xprt: controlling transport instance * * Returns 0 on success or a negative errno. */ int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt) { struct rpc_xprt *xprt = &r_xprt->rx_xprt; struct rpcrdma_ep *ep; int rc; rc = rpcrdma_ep_create(r_xprt); if (rc) return rc; ep = r_xprt->rx_ep; xprt_clear_connected(xprt); rpcrdma_reset_cwnd(r_xprt); /* Bump the ep's reference count while there are * outstanding Receives. */ rpcrdma_ep_get(ep); rpcrdma_post_recvs(r_xprt, true); rc = rdma_connect(ep->re_id, &ep->re_remote_cma); if (rc) goto out; if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO) xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO; wait_event_interruptible(ep->re_connect_wait, ep->re_connect_status != 0); if (ep->re_connect_status <= 0) { rc = ep->re_connect_status; goto out; } rc = rpcrdma_sendctxs_create(r_xprt); if (rc) { rc = -ENOTCONN; goto out; } rc = rpcrdma_reqs_setup(r_xprt); if (rc) { rc = -ENOTCONN; goto out; } rpcrdma_mrs_create(r_xprt); out: trace_xprtrdma_connect(r_xprt, rc); return rc; } /** * rpcrdma_xprt_disconnect - Disconnect underlying transport * @r_xprt: controlling transport instance * * Caller serializes. Either the transport send lock is held, * or we're being called to destroy the transport. * * On return, @r_xprt is completely divested of all hardware * resources and prepared for the next ->connect operation. */ void rpcrdma_xprt_disconnect(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_ep *ep = r_xprt->rx_ep; struct rdma_cm_id *id; int rc; if (!ep) return; id = ep->re_id; rc = rdma_disconnect(id); trace_xprtrdma_disconnect(r_xprt, rc); rpcrdma_xprt_drain(r_xprt); rpcrdma_reps_unmap(r_xprt); rpcrdma_reqs_reset(r_xprt); rpcrdma_mrs_destroy(r_xprt); rpcrdma_sendctxs_destroy(r_xprt); if (rpcrdma_ep_put(ep)) rdma_destroy_id(id); r_xprt->rx_ep = NULL; } /* Fixed-size circular FIFO queue. This implementation is wait-free and * lock-free. * * Consumer is the code path that posts Sends. This path dequeues a * sendctx for use by a Send operation. Multiple consumer threads * are serialized by the RPC transport lock, which allows only one * ->send_request call at a time. * * Producer is the code path that handles Send completions. This path * enqueues a sendctx that has been completed. Multiple producer * threads are serialized by the ib_poll_cq() function. */ /* rpcrdma_sendctxs_destroy() assumes caller has already quiesced * queue activity, and rpcrdma_xprt_drain has flushed all remaining * Send requests. */ static void rpcrdma_sendctxs_destroy(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; unsigned long i; if (!buf->rb_sc_ctxs) return; for (i = 0; i <= buf->rb_sc_last; i++) kfree(buf->rb_sc_ctxs[i]); kfree(buf->rb_sc_ctxs); buf->rb_sc_ctxs = NULL; } static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ep *ep) { struct rpcrdma_sendctx *sc; sc = kzalloc(struct_size(sc, sc_sges, ep->re_attr.cap.max_send_sge), GFP_KERNEL); if (!sc) return NULL; sc->sc_cqe.done = rpcrdma_wc_send; sc->sc_cid.ci_queue_id = ep->re_attr.send_cq->res.id; sc->sc_cid.ci_completion_id = atomic_inc_return(&ep->re_completion_ids); return sc; } static int rpcrdma_sendctxs_create(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpcrdma_sendctx *sc; unsigned long i; /* Maximum number of concurrent outstanding Send WRs. Capping * the circular queue size stops Send Queue overflow by causing * the ->send_request call to fail temporarily before too many * Sends are posted. */ i = r_xprt->rx_ep->re_max_requests + RPCRDMA_MAX_BC_REQUESTS; buf->rb_sc_ctxs = kcalloc(i, sizeof(sc), GFP_KERNEL); if (!buf->rb_sc_ctxs) return -ENOMEM; buf->rb_sc_last = i - 1; for (i = 0; i <= buf->rb_sc_last; i++) { sc = rpcrdma_sendctx_create(r_xprt->rx_ep); if (!sc) return -ENOMEM; buf->rb_sc_ctxs[i] = sc; } buf->rb_sc_head = 0; buf->rb_sc_tail = 0; return 0; } /* The sendctx queue is not guaranteed to have a size that is a * power of two, thus the helpers in circ_buf.h cannot be used. * The other option is to use modulus (%), which can be expensive. */ static unsigned long rpcrdma_sendctx_next(struct rpcrdma_buffer *buf, unsigned long item) { return likely(item < buf->rb_sc_last) ? item + 1 : 0; } /** * rpcrdma_sendctx_get_locked - Acquire a send context * @r_xprt: controlling transport instance * * Returns pointer to a free send completion context; or NULL if * the queue is empty. * * Usage: Called to acquire an SGE array before preparing a Send WR. * * The caller serializes calls to this function (per transport), and * provides an effective memory barrier that flushes the new value * of rb_sc_head. */ struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpcrdma_sendctx *sc; unsigned long next_head; next_head = rpcrdma_sendctx_next(buf, buf->rb_sc_head); if (next_head == READ_ONCE(buf->rb_sc_tail)) goto out_emptyq; /* ORDER: item must be accessed _before_ head is updated */ sc = buf->rb_sc_ctxs[next_head]; /* Releasing the lock in the caller acts as a memory * barrier that flushes rb_sc_head. */ buf->rb_sc_head = next_head; return sc; out_emptyq: /* The queue is "empty" if there have not been enough Send * completions recently. This is a sign the Send Queue is * backing up. Cause the caller to pause and try again. */ xprt_wait_for_buffer_space(&r_xprt->rx_xprt); r_xprt->rx_stats.empty_sendctx_q++; return NULL; } /** * rpcrdma_sendctx_put_locked - Release a send context * @r_xprt: controlling transport instance * @sc: send context to release * * Usage: Called from Send completion to return a sendctxt * to the queue. * * The caller serializes calls to this function (per transport). */ static void rpcrdma_sendctx_put_locked(struct rpcrdma_xprt *r_xprt, struct rpcrdma_sendctx *sc) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; unsigned long next_tail; /* Unmap SGEs of previously completed but unsignaled * Sends by walking up the queue until @sc is found. */ next_tail = buf->rb_sc_tail; do { next_tail = rpcrdma_sendctx_next(buf, next_tail); /* ORDER: item must be accessed _before_ tail is updated */ rpcrdma_sendctx_unmap(buf->rb_sc_ctxs[next_tail]); } while (buf->rb_sc_ctxs[next_tail] != sc); /* Paired with READ_ONCE */ smp_store_release(&buf->rb_sc_tail, next_tail); xprt_write_space(&r_xprt->rx_xprt); } static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpcrdma_ep *ep = r_xprt->rx_ep; unsigned int count; for (count = 0; count < ep->re_max_rdma_segs; count++) { struct rpcrdma_mr *mr; int rc; mr = kzalloc(sizeof(*mr), GFP_NOFS); if (!mr) break; rc = frwr_mr_init(r_xprt, mr); if (rc) { kfree(mr); break; } spin_lock(&buf->rb_lock); rpcrdma_mr_push(mr, &buf->rb_mrs); list_add(&mr->mr_all, &buf->rb_all_mrs); spin_unlock(&buf->rb_lock); } r_xprt->rx_stats.mrs_allocated += count; trace_xprtrdma_createmrs(r_xprt, count); } static void rpcrdma_mr_refresh_worker(struct work_struct *work) { struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer, rb_refresh_worker); struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt, rx_buf); rpcrdma_mrs_create(r_xprt); xprt_write_space(&r_xprt->rx_xprt); } /** * rpcrdma_mrs_refresh - Wake the MR refresh worker * @r_xprt: controlling transport instance * */ void rpcrdma_mrs_refresh(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpcrdma_ep *ep = r_xprt->rx_ep; /* If there is no underlying connection, it's no use * to wake the refresh worker. */ if (ep->re_connect_status == 1) { /* The work is scheduled on a WQ_MEM_RECLAIM * workqueue in order to prevent MR allocation * from recursing into NFS during direct reclaim. */ queue_work(xprtiod_workqueue, &buf->rb_refresh_worker); } } /** * rpcrdma_req_create - Allocate an rpcrdma_req object * @r_xprt: controlling r_xprt * @size: initial size, in bytes, of send and receive buffers * @flags: GFP flags passed to memory allocators * * Returns an allocated and fully initialized rpcrdma_req or NULL. */ struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, size_t size, gfp_t flags) { struct rpcrdma_buffer *buffer = &r_xprt->rx_buf; struct rpcrdma_req *req; req = kzalloc(sizeof(*req), flags); if (req == NULL) goto out1; req->rl_sendbuf = rpcrdma_regbuf_alloc(size, DMA_TO_DEVICE, flags); if (!req->rl_sendbuf) goto out2; req->rl_recvbuf = rpcrdma_regbuf_alloc(size, DMA_NONE, flags); if (!req->rl_recvbuf) goto out3; INIT_LIST_HEAD(&req->rl_free_mrs); INIT_LIST_HEAD(&req->rl_registered); spin_lock(&buffer->rb_lock); list_add(&req->rl_all, &buffer->rb_allreqs); spin_unlock(&buffer->rb_lock); return req; out3: kfree(req->rl_sendbuf); out2: kfree(req); out1: return NULL; } /** * rpcrdma_req_setup - Per-connection instance setup of an rpcrdma_req object * @r_xprt: controlling transport instance * @req: rpcrdma_req object to set up * * Returns zero on success, and a negative errno on failure. */ int rpcrdma_req_setup(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req) { struct rpcrdma_regbuf *rb; size_t maxhdrsize; /* Compute maximum header buffer size in bytes */ maxhdrsize = rpcrdma_fixed_maxsz + 3 + r_xprt->rx_ep->re_max_rdma_segs * rpcrdma_readchunk_maxsz; maxhdrsize *= sizeof(__be32); rb = rpcrdma_regbuf_alloc(__roundup_pow_of_two(maxhdrsize), DMA_TO_DEVICE, GFP_KERNEL); if (!rb) goto out; if (!__rpcrdma_regbuf_dma_map(r_xprt, rb)) goto out_free; req->rl_rdmabuf = rb; xdr_buf_init(&req->rl_hdrbuf, rdmab_data(rb), rdmab_length(rb)); return 0; out_free: rpcrdma_regbuf_free(rb); out: return -ENOMEM; } /* ASSUMPTION: the rb_allreqs list is stable for the duration, * and thus can be walked without holding rb_lock. Eg. the * caller is holding the transport send lock to exclude * device removal or disconnection. */ static int rpcrdma_reqs_setup(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpcrdma_req *req; int rc; list_for_each_entry(req, &buf->rb_allreqs, rl_all) { rc = rpcrdma_req_setup(r_xprt, req); if (rc) return rc; } return 0; } static void rpcrdma_req_reset(struct rpcrdma_req *req) { /* Credits are valid for only one connection */ req->rl_slot.rq_cong = 0; rpcrdma_regbuf_free(req->rl_rdmabuf); req->rl_rdmabuf = NULL; rpcrdma_regbuf_dma_unmap(req->rl_sendbuf); rpcrdma_regbuf_dma_unmap(req->rl_recvbuf); frwr_reset(req); } /* ASSUMPTION: the rb_allreqs list is stable for the duration, * and thus can be walked without holding rb_lock. Eg. the * caller is holding the transport send lock to exclude * device removal or disconnection. */ static void rpcrdma_reqs_reset(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpcrdma_req *req; list_for_each_entry(req, &buf->rb_allreqs, rl_all) rpcrdma_req_reset(req); } static noinline struct rpcrdma_rep *rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt, bool temp) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpcrdma_rep *rep; rep = kzalloc(sizeof(*rep), GFP_KERNEL); if (rep == NULL) goto out; rep->rr_rdmabuf = rpcrdma_regbuf_alloc(r_xprt->rx_ep->re_inline_recv, DMA_FROM_DEVICE, GFP_KERNEL); if (!rep->rr_rdmabuf) goto out_free; if (!rpcrdma_regbuf_dma_map(r_xprt, rep->rr_rdmabuf)) goto out_free_regbuf; rep->rr_cid.ci_completion_id = atomic_inc_return(&r_xprt->rx_ep->re_completion_ids); xdr_buf_init(&rep->rr_hdrbuf, rdmab_data(rep->rr_rdmabuf), rdmab_length(rep->rr_rdmabuf)); rep->rr_cqe.done = rpcrdma_wc_receive; rep->rr_rxprt = r_xprt; rep->rr_recv_wr.next = NULL; rep->rr_recv_wr.wr_cqe = &rep->rr_cqe; rep->rr_recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov; rep->rr_recv_wr.num_sge = 1; rep->rr_temp = temp; spin_lock(&buf->rb_lock); list_add(&rep->rr_all, &buf->rb_all_reps); spin_unlock(&buf->rb_lock); return rep; out_free_regbuf: rpcrdma_regbuf_free(rep->rr_rdmabuf); out_free: kfree(rep); out: return NULL; } static void rpcrdma_rep_free(struct rpcrdma_rep *rep) { rpcrdma_regbuf_free(rep->rr_rdmabuf); kfree(rep); } static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep) { struct rpcrdma_buffer *buf = &rep->rr_rxprt->rx_buf; spin_lock(&buf->rb_lock); list_del(&rep->rr_all); spin_unlock(&buf->rb_lock); rpcrdma_rep_free(rep); } static struct rpcrdma_rep *rpcrdma_rep_get_locked(struct rpcrdma_buffer *buf) { struct llist_node *node; /* Calls to llist_del_first are required to be serialized */ node = llist_del_first(&buf->rb_free_reps); if (!node) return NULL; return llist_entry(node, struct rpcrdma_rep, rr_node); } static void rpcrdma_rep_put(struct rpcrdma_buffer *buf, struct rpcrdma_rep *rep) { llist_add(&rep->rr_node, &buf->rb_free_reps); } /* Caller must ensure the QP is quiescent (RQ is drained) before * invoking this function, to guarantee rb_all_reps is not * changing. */ static void rpcrdma_reps_unmap(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpcrdma_rep *rep; list_for_each_entry(rep, &buf->rb_all_reps, rr_all) { rpcrdma_regbuf_dma_unmap(rep->rr_rdmabuf); rep->rr_temp = true; /* Mark this rep for destruction */ } } static void rpcrdma_reps_destroy(struct rpcrdma_buffer *buf) { struct rpcrdma_rep *rep; spin_lock(&buf->rb_lock); while ((rep = list_first_entry_or_null(&buf->rb_all_reps, struct rpcrdma_rep, rr_all)) != NULL) { list_del(&rep->rr_all); spin_unlock(&buf->rb_lock); rpcrdma_rep_free(rep); spin_lock(&buf->rb_lock); } spin_unlock(&buf->rb_lock); } /** * rpcrdma_buffer_create - Create initial set of req/rep objects * @r_xprt: transport instance to (re)initialize * * Returns zero on success, otherwise a negative errno. */ int rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; int i, rc; buf->rb_bc_srv_max_requests = 0; spin_lock_init(&buf->rb_lock); INIT_LIST_HEAD(&buf->rb_mrs); INIT_LIST_HEAD(&buf->rb_all_mrs); INIT_WORK(&buf->rb_refresh_worker, rpcrdma_mr_refresh_worker); INIT_LIST_HEAD(&buf->rb_send_bufs); INIT_LIST_HEAD(&buf->rb_allreqs); INIT_LIST_HEAD(&buf->rb_all_reps); rc = -ENOMEM; for (i = 0; i < r_xprt->rx_xprt.max_reqs; i++) { struct rpcrdma_req *req; req = rpcrdma_req_create(r_xprt, RPCRDMA_V1_DEF_INLINE_SIZE * 2, GFP_KERNEL); if (!req) goto out; list_add(&req->rl_list, &buf->rb_send_bufs); } init_llist_head(&buf->rb_free_reps); return 0; out: rpcrdma_buffer_destroy(buf); return rc; } /** * rpcrdma_req_destroy - Destroy an rpcrdma_req object * @req: unused object to be destroyed * * Relies on caller holding the transport send lock to protect * removing req->rl_all from buf->rb_all_reqs safely. */ void rpcrdma_req_destroy(struct rpcrdma_req *req) { struct rpcrdma_mr *mr; list_del(&req->rl_all); while ((mr = rpcrdma_mr_pop(&req->rl_free_mrs))) { struct rpcrdma_buffer *buf = &mr->mr_xprt->rx_buf; spin_lock(&buf->rb_lock); list_del(&mr->mr_all); spin_unlock(&buf->rb_lock); frwr_release_mr(mr); } rpcrdma_regbuf_free(req->rl_recvbuf); rpcrdma_regbuf_free(req->rl_sendbuf); rpcrdma_regbuf_free(req->rl_rdmabuf); kfree(req); } /** * rpcrdma_mrs_destroy - Release all of a transport's MRs * @r_xprt: controlling transport instance * * Relies on caller holding the transport send lock to protect * removing mr->mr_list from req->rl_free_mrs safely. */ static void rpcrdma_mrs_destroy(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpcrdma_mr *mr; cancel_work_sync(&buf->rb_refresh_worker); spin_lock(&buf->rb_lock); while ((mr = list_first_entry_or_null(&buf->rb_all_mrs, struct rpcrdma_mr, mr_all)) != NULL) { list_del(&mr->mr_list); list_del(&mr->mr_all); spin_unlock(&buf->rb_lock); frwr_release_mr(mr); spin_lock(&buf->rb_lock); } spin_unlock(&buf->rb_lock); } /** * rpcrdma_buffer_destroy - Release all hw resources * @buf: root control block for resources * * ORDERING: relies on a prior rpcrdma_xprt_drain : * - No more Send or Receive completions can occur * - All MRs, reps, and reqs are returned to their free lists */ void rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf) { rpcrdma_reps_destroy(buf); while (!list_empty(&buf->rb_send_bufs)) { struct rpcrdma_req *req; req = list_first_entry(&buf->rb_send_bufs, struct rpcrdma_req, rl_list); list_del(&req->rl_list); rpcrdma_req_destroy(req); } } /** * rpcrdma_mr_get - Allocate an rpcrdma_mr object * @r_xprt: controlling transport * * Returns an initialized rpcrdma_mr or NULL if no free * rpcrdma_mr objects are available. */ struct rpcrdma_mr * rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpcrdma_mr *mr; spin_lock(&buf->rb_lock); mr = rpcrdma_mr_pop(&buf->rb_mrs); spin_unlock(&buf->rb_lock); return mr; } /** * rpcrdma_buffer_get - Get a request buffer * @buffers: Buffer pool from which to obtain a buffer * * Returns a fresh rpcrdma_req, or NULL if none are available. */ struct rpcrdma_req * rpcrdma_buffer_get(struct rpcrdma_buffer *buffers) { struct rpcrdma_req *req; spin_lock(&buffers->rb_lock); req = list_first_entry_or_null(&buffers->rb_send_bufs, struct rpcrdma_req, rl_list); if (req) list_del_init(&req->rl_list); spin_unlock(&buffers->rb_lock); return req; } /** * rpcrdma_buffer_put - Put request/reply buffers back into pool * @buffers: buffer pool * @req: object to return * */ void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req) { if (req->rl_reply) rpcrdma_rep_put(buffers, req->rl_reply); req->rl_reply = NULL; spin_lock(&buffers->rb_lock); list_add(&req->rl_list, &buffers->rb_send_bufs); spin_unlock(&buffers->rb_lock); } /** * rpcrdma_recv_buffer_put - Release rpcrdma_rep back to free list * @rep: rep to release * * Used after error conditions. */ void rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep) { rpcrdma_rep_put(&rep->rr_rxprt->rx_buf, rep); } /* Returns a pointer to a rpcrdma_regbuf object, or NULL. * * xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for * receiving the payload of RDMA RECV operations. During Long Calls * or Replies they may be registered externally via frwr_map. */ static struct rpcrdma_regbuf * rpcrdma_regbuf_alloc(size_t size, enum dma_data_direction direction, gfp_t flags) { struct rpcrdma_regbuf *rb; rb = kmalloc(sizeof(*rb), flags); if (!rb) return NULL; rb->rg_data = kmalloc(size, flags); if (!rb->rg_data) { kfree(rb); return NULL; } rb->rg_device = NULL; rb->rg_direction = direction; rb->rg_iov.length = size; return rb; } /** * rpcrdma_regbuf_realloc - re-allocate a SEND/RECV buffer * @rb: regbuf to reallocate * @size: size of buffer to be allocated, in bytes * @flags: GFP flags * * Returns true if reallocation was successful. If false is * returned, @rb is left untouched. */ bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size, gfp_t flags) { void *buf; buf = kmalloc(size, flags); if (!buf) return false; rpcrdma_regbuf_dma_unmap(rb); kfree(rb->rg_data); rb->rg_data = buf; rb->rg_iov.length = size; return true; } /** * __rpcrdma_regbuf_dma_map - DMA-map a regbuf * @r_xprt: controlling transport instance * @rb: regbuf to be mapped * * Returns true if the buffer is now DMA mapped to @r_xprt's device */ bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_regbuf *rb) { struct ib_device *device = r_xprt->rx_ep->re_id->device; if (rb->rg_direction == DMA_NONE) return false; rb->rg_iov.addr = ib_dma_map_single(device, rdmab_data(rb), rdmab_length(rb), rb->rg_direction); if (ib_dma_mapping_error(device, rdmab_addr(rb))) { trace_xprtrdma_dma_maperr(rdmab_addr(rb)); return false; } rb->rg_device = device; rb->rg_iov.lkey = r_xprt->rx_ep->re_pd->local_dma_lkey; return true; } static void rpcrdma_regbuf_dma_unmap(struct rpcrdma_regbuf *rb) { if (!rb) return; if (!rpcrdma_regbuf_is_mapped(rb)) return; ib_dma_unmap_single(rb->rg_device, rdmab_addr(rb), rdmab_length(rb), rb->rg_direction); rb->rg_device = NULL; } static void rpcrdma_regbuf_free(struct rpcrdma_regbuf *rb) { rpcrdma_regbuf_dma_unmap(rb); if (rb) kfree(rb->rg_data); kfree(rb); } /** * rpcrdma_post_sends - Post WRs to a transport's Send Queue * @r_xprt: controlling transport instance * @req: rpcrdma_req containing the Send WR to post * * Returns 0 if the post was successful, otherwise -ENOTCONN * is returned. */ int rpcrdma_post_sends(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req) { struct ib_send_wr *send_wr = &req->rl_wr; struct rpcrdma_ep *ep = r_xprt->rx_ep; int rc; if (!ep->re_send_count || kref_read(&req->rl_kref) > 1) { send_wr->send_flags |= IB_SEND_SIGNALED; ep->re_send_count = ep->re_send_batch; } else { send_wr->send_flags &= ~IB_SEND_SIGNALED; --ep->re_send_count; } trace_xprtrdma_post_send(req); rc = frwr_send(r_xprt, req); if (rc) return -ENOTCONN; return 0; } /** * rpcrdma_post_recvs - Refill the Receive Queue * @r_xprt: controlling transport instance * @temp: mark Receive buffers to be deleted after use * */ void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp) { struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpcrdma_ep *ep = r_xprt->rx_ep; struct ib_recv_wr *wr, *bad_wr; struct rpcrdma_rep *rep; int needed, count, rc; rc = 0; count = 0; needed = buf->rb_credits + (buf->rb_bc_srv_max_requests << 1); if (likely(ep->re_receive_count > needed)) goto out; needed -= ep->re_receive_count; if (!temp) needed += RPCRDMA_MAX_RECV_BATCH; if (atomic_inc_return(&ep->re_receiving) > 1) goto out; /* fast path: all needed reps can be found on the free list */ wr = NULL; while (needed) { rep = rpcrdma_rep_get_locked(buf); if (rep && rep->rr_temp) { rpcrdma_rep_destroy(rep); continue; } if (!rep) rep = rpcrdma_rep_create(r_xprt, temp); if (!rep) break; rep->rr_cid.ci_queue_id = ep->re_attr.recv_cq->res.id; trace_xprtrdma_post_recv(rep); rep->rr_recv_wr.next = wr; wr = &rep->rr_recv_wr; --needed; ++count; } if (!wr) goto out; rc = ib_post_recv(ep->re_id->qp, wr, (const struct ib_recv_wr **)&bad_wr); if (atomic_dec_return(&ep->re_receiving) > 0) complete(&ep->re_done); out: trace_xprtrdma_post_recvs(r_xprt, count, rc); if (rc) { for (wr = bad_wr; wr;) { struct rpcrdma_rep *rep; rep = container_of(wr, struct rpcrdma_rep, rr_recv_wr); wr = wr->next; rpcrdma_recv_buffer_put(rep); --count; } } ep->re_receive_count += count; return; }