Orange Pi5 kernel

// 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>
 
/*
 * 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_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;
 
<------>/* 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(sc, wc);
<------>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);
<------>--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_destroy(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;
 
<------>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);
<------><------>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);
 
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;
<------>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);
}
 
/* No locking needed here. This function is called only by the
 * Receive completion handler.
 */
static noinline
struct rpcrdma_rep *rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt,
<------><------><------><------>       bool temp)
 {
<------>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;
 
<------>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;
<------>list_add(&rep->rr_all, &r_xprt->rx_buf.rb_all_reps);
<------>return rep;
 
out_free_regbuf:
<------>rpcrdma_regbuf_free(rep->rr_rdmabuf);
out_free:
<------>kfree(rep);
out:
<------>return NULL;
}
 
/* No locking needed here. This function is invoked only by the
 * Receive completion handler, or during transport shutdown.
 */
static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep)
{
<------>list_del(&rep->rr_all);
<------>rpcrdma_regbuf_free(rep->rr_rdmabuf);
<------>kfree(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);
}
 
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;
<------>}
}
 
static void rpcrdma_reps_destroy(struct rpcrdma_buffer *buf)
{
<------>struct rpcrdma_rep *rep;
 
<------>while ((rep = rpcrdma_rep_get_locked(buf)) != NULL)
<------><------>rpcrdma_rep_destroy(rep);
}
 
/**
 * 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_mr_put - DMA unmap an MR and release it
 * @mr: MR to release
 *
 */
void rpcrdma_mr_put(struct rpcrdma_mr *mr)
{
<------>struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
 
<------>if (mr->mr_dir != DMA_NONE) {
<------><------>trace_xprtrdma_mr_unmap(mr);
<------><------>ib_dma_unmap_sg(r_xprt->rx_ep->re_id->device,
<------><------><------><------>mr->mr_sg, mr->mr_nents, mr->mr_dir);
<------><------>mr->mr_dir = DMA_NONE;
<------>}
 
<------>rpcrdma_mr_push(mr, &mr->mr_req->rl_free_mrs);
}
 
/**
 * 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);
}
 
/**
 * 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
 * @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;
 
<------>/* 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;
 
<------><------>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);
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;
}