diff options
Diffstat (limited to 'net/sunrpc/xprtrdma/verbs.c')
| -rw-r--r-- | net/sunrpc/xprtrdma/verbs.c | 1396 |
1 files changed, 1396 insertions, 0 deletions
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c new file mode 100644 index 0000000000..28c0771c4e --- /dev/null +++ b/net/sunrpc/xprtrdma/verbs.c @@ -0,0 +1,1396 @@ +// 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 <linux/interrupt.h> +#include <linux/slab.h> +#include <linux/sunrpc/addr.h> +#include <linux/sunrpc/svc_rdma.h> +#include <linux/log2.h> + +#include <asm-generic/barrier.h> +#include <asm/bitops.h> + +#include <rdma/ib_cm.h> + +#include "xprt_rdma.h" +#include <trace/events/rpcrdma.h> + +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_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); +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); +} + +/* 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). + */ +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 */ + 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) { + 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: + 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; + } + + 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), XPRTRDMA_GFP_FLAGS); + 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.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; + + 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); + ep->re_attr.send_cq = NULL; + 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); + ep->re_attr.recv_cq = NULL; + 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); + ep->re_pd = NULL; + 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, 1, 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); + frwr_wp_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), + XPRTRDMA_GFP_FLAGS); + 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), XPRTRDMA_GFP_FLAGS); + 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; + struct ib_device *device = ep->re_id->device; + unsigned int count; + + /* Try to allocate enough to perform one full-sized I/O */ + for (count = 0; count < ep->re_max_rdma_segs; count++) { + struct rpcrdma_mr *mr; + int rc; + + mr = kzalloc_node(sizeof(*mr), XPRTRDMA_GFP_FLAGS, + ibdev_to_node(device)); + 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) + return; + queue_work(system_highpri_wq, &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 + * + * Returns an allocated and fully initialized rpcrdma_req or NULL. + */ +struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, + size_t size) +{ + struct rpcrdma_buffer *buffer = &r_xprt->rx_buf; + struct rpcrdma_req *req; + + req = kzalloc(sizeof(*req), XPRTRDMA_GFP_FLAGS); + if (req == NULL) + goto out1; + + req->rl_sendbuf = rpcrdma_regbuf_alloc(size, DMA_TO_DEVICE); + if (!req->rl_sendbuf) + goto out2; + + req->rl_recvbuf = rpcrdma_regbuf_alloc(size, DMA_NONE); + 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: + rpcrdma_regbuf_free(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); + 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), XPRTRDMA_GFP_FLAGS); + if (rep == NULL) + goto out; + + rep->rr_rdmabuf = rpcrdma_regbuf_alloc(r_xprt->rx_ep->re_inline_recv, + DMA_FROM_DEVICE); + if (!rep->rr_rdmabuf) + goto out_free; + + 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: + 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); +} + +/** + * rpcrdma_rep_put - Release rpcrdma_rep back to free list + * @buf: buffer pool + * @rep: rep to release + * + */ +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); + 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_mr_release(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_mr_release(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_reply_put - Put reply buffers back into pool + * @buffers: buffer pool + * @req: object to return + * + */ +void rpcrdma_reply_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req) +{ + if (req->rl_reply) { + rpcrdma_rep_put(buffers, req->rl_reply); + req->rl_reply = NULL; + } +} + +/** + * 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) +{ + rpcrdma_reply_put(buffers, req); + + spin_lock(&buffers->rb_lock); + list_add(&req->rl_list, &buffers->rb_send_bufs); + spin_unlock(&buffers->rb_lock); +} + +/* 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) +{ + struct rpcrdma_regbuf *rb; + + rb = kmalloc(sizeof(*rb), XPRTRDMA_GFP_FLAGS); + if (!rb) + return NULL; + rb->rg_data = kmalloc(size, XPRTRDMA_GFP_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_recvs - Refill the Receive Queue + * @r_xprt: controlling transport instance + * @needed: current credit grant + * @temp: mark Receive buffers to be deleted after one use + * + */ +void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed, 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 count, rc; + + rc = 0; + count = 0; + + 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; + if (!rpcrdma_regbuf_dma_map(r_xprt, rep->rr_rdmabuf)) { + rpcrdma_rep_put(buf, 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 (rc) { + trace_xprtrdma_post_recvs_err(r_xprt, rc); + for (wr = bad_wr; wr;) { + struct rpcrdma_rep *rep; + + rep = container_of(wr, struct rpcrdma_rep, rr_recv_wr); + wr = wr->next; + rpcrdma_rep_put(buf, rep); + --count; + } + } + if (atomic_dec_return(&ep->re_receiving) > 0) + complete(&ep->re_done); + +out: + trace_xprtrdma_post_recvs(r_xprt, count); + ep->re_receive_count += count; + return; +} |