v4.19.13 snapshot.
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
new file mode 100644
index 0000000..956a5ea
--- /dev/null
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -0,0 +1,1574 @@
+// 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 <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 void rpcrdma_sendctx_put_locked(struct rpcrdma_sendctx *sc);
+static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt);
+static void rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf);
+static int rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt, bool temp);
+static void rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb);
+
+struct workqueue_struct *rpcrdma_receive_wq __read_mostly;
+
+int
+rpcrdma_alloc_wq(void)
+{
+ struct workqueue_struct *recv_wq;
+
+ recv_wq = alloc_workqueue("xprtrdma_receive",
+ WQ_MEM_RECLAIM | WQ_HIGHPRI,
+ 0);
+ if (!recv_wq)
+ return -ENOMEM;
+
+ rpcrdma_receive_wq = recv_wq;
+ return 0;
+}
+
+void
+rpcrdma_destroy_wq(void)
+{
+ struct workqueue_struct *wq;
+
+ if (rpcrdma_receive_wq) {
+ wq = rpcrdma_receive_wq;
+ rpcrdma_receive_wq = NULL;
+ destroy_workqueue(wq);
+ }
+}
+
+static void
+rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
+{
+ struct rpcrdma_ep *ep = context;
+ struct rpcrdma_xprt *r_xprt = container_of(ep, struct rpcrdma_xprt,
+ rx_ep);
+
+ trace_xprtrdma_qp_error(r_xprt, event);
+ pr_err("rpcrdma: %s on device %s ep %p\n",
+ ib_event_msg(event->event), event->device->name, context);
+
+ if (ep->rep_connected == 1) {
+ ep->rep_connected = -EIO;
+ rpcrdma_conn_func(ep);
+ wake_up_all(&ep->rep_connect_wait);
+ }
+}
+
+/**
+ * rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC
+ * @cq: completion queue (ignored)
+ * @wc: completed 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);
+
+ /* WARNING: Only wr_cqe and status are reliable at this point */
+ trace_xprtrdma_wc_send(sc, wc);
+ if (wc->status != IB_WC_SUCCESS && wc->status != IB_WC_WR_FLUSH_ERR)
+ pr_err("rpcrdma: Send: %s (%u/0x%x)\n",
+ ib_wc_status_msg(wc->status),
+ wc->status, wc->vendor_err);
+
+ rpcrdma_sendctx_put_locked(sc);
+}
+
+/**
+ * rpcrdma_wc_receive - Invoked by RDMA provider for each polled Receive WC
+ * @cq: completion queue (ignored)
+ * @wc: completed 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);
+
+ /* WARNING: Only wr_id and status are reliable at this point */
+ trace_xprtrdma_wc_receive(wc);
+ if (wc->status != IB_WC_SUCCESS)
+ goto out_fail;
+
+ /* 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);
+
+out_schedule:
+ rpcrdma_reply_handler(rep);
+ return;
+
+out_fail:
+ if (wc->status != IB_WC_WR_FLUSH_ERR)
+ pr_err("rpcrdma: Recv: %s (%u/0x%x)\n",
+ ib_wc_status_msg(wc->status),
+ wc->status, wc->vendor_err);
+ rpcrdma_set_xdrlen(&rep->rr_hdrbuf, 0);
+ goto out_schedule;
+}
+
+static void
+rpcrdma_update_connect_private(struct rpcrdma_xprt *r_xprt,
+ struct rdma_conn_param *param)
+{
+ struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
+ const struct rpcrdma_connect_private *pmsg = param->private_data;
+ unsigned int rsize, wsize;
+
+ /* Default settings for RPC-over-RDMA Version One */
+ r_xprt->rx_ia.ri_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) {
+ r_xprt->rx_ia.ri_implicit_roundup = true;
+ rsize = rpcrdma_decode_buffer_size(pmsg->cp_send_size);
+ wsize = rpcrdma_decode_buffer_size(pmsg->cp_recv_size);
+ }
+
+ if (rsize < cdata->inline_rsize)
+ cdata->inline_rsize = rsize;
+ if (wsize < cdata->inline_wsize)
+ cdata->inline_wsize = wsize;
+ dprintk("RPC: %s: max send %u, max recv %u\n",
+ __func__, cdata->inline_wsize, cdata->inline_rsize);
+ rpcrdma_set_max_header_sizes(r_xprt);
+}
+
+static int
+rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
+{
+ struct rpcrdma_xprt *xprt = id->context;
+ struct rpcrdma_ia *ia = &xprt->rx_ia;
+ struct rpcrdma_ep *ep = &xprt->rx_ep;
+ int connstate = 0;
+
+ trace_xprtrdma_conn_upcall(xprt, event);
+ switch (event->event) {
+ case RDMA_CM_EVENT_ADDR_RESOLVED:
+ case RDMA_CM_EVENT_ROUTE_RESOLVED:
+ ia->ri_async_rc = 0;
+ complete(&ia->ri_done);
+ break;
+ case RDMA_CM_EVENT_ADDR_ERROR:
+ ia->ri_async_rc = -EPROTO;
+ complete(&ia->ri_done);
+ break;
+ case RDMA_CM_EVENT_ROUTE_ERROR:
+ ia->ri_async_rc = -ENETUNREACH;
+ complete(&ia->ri_done);
+ break;
+ case RDMA_CM_EVENT_DEVICE_REMOVAL:
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+ pr_info("rpcrdma: removing device %s for %s:%s\n",
+ ia->ri_device->name,
+ rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt));
+#endif
+ set_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags);
+ ep->rep_connected = -ENODEV;
+ xprt_force_disconnect(&xprt->rx_xprt);
+ wait_for_completion(&ia->ri_remove_done);
+
+ ia->ri_id = NULL;
+ ia->ri_device = NULL;
+ /* Return 1 to ensure the core destroys the id. */
+ return 1;
+ case RDMA_CM_EVENT_ESTABLISHED:
+ ++xprt->rx_xprt.connect_cookie;
+ connstate = 1;
+ rpcrdma_update_connect_private(xprt, &event->param.conn);
+ goto connected;
+ case RDMA_CM_EVENT_CONNECT_ERROR:
+ connstate = -ENOTCONN;
+ goto connected;
+ case RDMA_CM_EVENT_UNREACHABLE:
+ connstate = -ENETUNREACH;
+ goto connected;
+ case RDMA_CM_EVENT_REJECTED:
+ dprintk("rpcrdma: connection to %s:%s rejected: %s\n",
+ rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt),
+ rdma_reject_msg(id, event->status));
+ connstate = -ECONNREFUSED;
+ if (event->status == IB_CM_REJ_STALE_CONN)
+ connstate = -EAGAIN;
+ goto connected;
+ case RDMA_CM_EVENT_DISCONNECTED:
+ ++xprt->rx_xprt.connect_cookie;
+ connstate = -ECONNABORTED;
+connected:
+ ep->rep_connected = connstate;
+ rpcrdma_conn_func(ep);
+ wake_up_all(&ep->rep_connect_wait);
+ /*FALLTHROUGH*/
+ default:
+ dprintk("RPC: %s: %s:%s on %s/%s (ep 0x%p): %s\n",
+ __func__,
+ rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt),
+ ia->ri_device->name, ia->ri_ops->ro_displayname,
+ ep, rdma_event_msg(event->event));
+ break;
+ }
+
+ return 0;
+}
+
+static struct rdma_cm_id *
+rpcrdma_create_id(struct rpcrdma_xprt *xprt, struct rpcrdma_ia *ia)
+{
+ unsigned long wtimeout = msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1;
+ struct rdma_cm_id *id;
+ int rc;
+
+ trace_xprtrdma_conn_start(xprt);
+
+ init_completion(&ia->ri_done);
+ init_completion(&ia->ri_remove_done);
+
+ id = rdma_create_id(xprt->rx_xprt.xprt_net, rpcrdma_conn_upcall,
+ xprt, RDMA_PS_TCP, IB_QPT_RC);
+ if (IS_ERR(id)) {
+ rc = PTR_ERR(id);
+ dprintk("RPC: %s: rdma_create_id() failed %i\n",
+ __func__, rc);
+ return id;
+ }
+
+ ia->ri_async_rc = -ETIMEDOUT;
+ rc = rdma_resolve_addr(id, NULL,
+ (struct sockaddr *)&xprt->rx_xprt.addr,
+ RDMA_RESOLVE_TIMEOUT);
+ if (rc) {
+ dprintk("RPC: %s: rdma_resolve_addr() failed %i\n",
+ __func__, rc);
+ goto out;
+ }
+ rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
+ if (rc < 0) {
+ trace_xprtrdma_conn_tout(xprt);
+ goto out;
+ }
+
+ rc = ia->ri_async_rc;
+ if (rc)
+ goto out;
+
+ ia->ri_async_rc = -ETIMEDOUT;
+ rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
+ if (rc) {
+ dprintk("RPC: %s: rdma_resolve_route() failed %i\n",
+ __func__, rc);
+ goto out;
+ }
+ rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
+ if (rc < 0) {
+ trace_xprtrdma_conn_tout(xprt);
+ goto out;
+ }
+ rc = ia->ri_async_rc;
+ if (rc)
+ goto out;
+
+ return id;
+
+out:
+ rdma_destroy_id(id);
+ return ERR_PTR(rc);
+}
+
+/*
+ * Exported functions.
+ */
+
+/**
+ * rpcrdma_ia_open - Open and initialize an Interface Adapter.
+ * @xprt: transport with IA to (re)initialize
+ *
+ * Returns 0 on success, negative errno if an appropriate
+ * Interface Adapter could not be found and opened.
+ */
+int
+rpcrdma_ia_open(struct rpcrdma_xprt *xprt)
+{
+ struct rpcrdma_ia *ia = &xprt->rx_ia;
+ int rc;
+
+ ia->ri_id = rpcrdma_create_id(xprt, ia);
+ if (IS_ERR(ia->ri_id)) {
+ rc = PTR_ERR(ia->ri_id);
+ goto out_err;
+ }
+ ia->ri_device = ia->ri_id->device;
+
+ ia->ri_pd = ib_alloc_pd(ia->ri_device, 0);
+ if (IS_ERR(ia->ri_pd)) {
+ rc = PTR_ERR(ia->ri_pd);
+ pr_err("rpcrdma: ib_alloc_pd() returned %d\n", rc);
+ goto out_err;
+ }
+
+ switch (xprt_rdma_memreg_strategy) {
+ case RPCRDMA_FRWR:
+ if (frwr_is_supported(ia)) {
+ ia->ri_ops = &rpcrdma_frwr_memreg_ops;
+ break;
+ }
+ /*FALLTHROUGH*/
+ case RPCRDMA_MTHCAFMR:
+ if (fmr_is_supported(ia)) {
+ ia->ri_ops = &rpcrdma_fmr_memreg_ops;
+ break;
+ }
+ /*FALLTHROUGH*/
+ default:
+ pr_err("rpcrdma: Device %s does not support memreg mode %d\n",
+ ia->ri_device->name, xprt_rdma_memreg_strategy);
+ rc = -EINVAL;
+ goto out_err;
+ }
+
+ return 0;
+
+out_err:
+ rpcrdma_ia_close(ia);
+ return rc;
+}
+
+/**
+ * rpcrdma_ia_remove - Handle device driver unload
+ * @ia: interface adapter being removed
+ *
+ * Divest transport H/W resources associated with this adapter,
+ * but allow it to be restored later.
+ */
+void
+rpcrdma_ia_remove(struct rpcrdma_ia *ia)
+{
+ struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
+ rx_ia);
+ struct rpcrdma_ep *ep = &r_xprt->rx_ep;
+ struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+ struct rpcrdma_req *req;
+ struct rpcrdma_rep *rep;
+
+ cancel_delayed_work_sync(&buf->rb_refresh_worker);
+
+ /* This is similar to rpcrdma_ep_destroy, but:
+ * - Don't cancel the connect worker.
+ * - Don't call rpcrdma_ep_disconnect, which waits
+ * for another conn upcall, which will deadlock.
+ * - rdma_disconnect is unneeded, the underlying
+ * connection is already gone.
+ */
+ if (ia->ri_id->qp) {
+ ib_drain_qp(ia->ri_id->qp);
+ rdma_destroy_qp(ia->ri_id);
+ ia->ri_id->qp = NULL;
+ }
+ ib_free_cq(ep->rep_attr.recv_cq);
+ ep->rep_attr.recv_cq = NULL;
+ ib_free_cq(ep->rep_attr.send_cq);
+ ep->rep_attr.send_cq = NULL;
+
+ /* The ULP is responsible for ensuring all DMA
+ * mappings and MRs are gone.
+ */
+ list_for_each_entry(rep, &buf->rb_recv_bufs, rr_list)
+ rpcrdma_dma_unmap_regbuf(rep->rr_rdmabuf);
+ list_for_each_entry(req, &buf->rb_allreqs, rl_all) {
+ rpcrdma_dma_unmap_regbuf(req->rl_rdmabuf);
+ rpcrdma_dma_unmap_regbuf(req->rl_sendbuf);
+ rpcrdma_dma_unmap_regbuf(req->rl_recvbuf);
+ }
+ rpcrdma_mrs_destroy(buf);
+ ib_dealloc_pd(ia->ri_pd);
+ ia->ri_pd = NULL;
+
+ /* Allow waiters to continue */
+ complete(&ia->ri_remove_done);
+
+ trace_xprtrdma_remove(r_xprt);
+}
+
+/**
+ * rpcrdma_ia_close - Clean up/close an IA.
+ * @ia: interface adapter to close
+ *
+ */
+void
+rpcrdma_ia_close(struct rpcrdma_ia *ia)
+{
+ if (ia->ri_id != NULL && !IS_ERR(ia->ri_id)) {
+ if (ia->ri_id->qp)
+ rdma_destroy_qp(ia->ri_id);
+ rdma_destroy_id(ia->ri_id);
+ }
+ ia->ri_id = NULL;
+ ia->ri_device = NULL;
+
+ /* If the pd is still busy, xprtrdma missed freeing a resource */
+ if (ia->ri_pd && !IS_ERR(ia->ri_pd))
+ ib_dealloc_pd(ia->ri_pd);
+ ia->ri_pd = NULL;
+}
+
+/*
+ * Create unconnected endpoint.
+ */
+int
+rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
+ struct rpcrdma_create_data_internal *cdata)
+{
+ struct rpcrdma_connect_private *pmsg = &ep->rep_cm_private;
+ struct ib_cq *sendcq, *recvcq;
+ unsigned int max_sge;
+ int rc;
+
+ max_sge = min_t(unsigned int, ia->ri_device->attrs.max_send_sge,
+ RPCRDMA_MAX_SEND_SGES);
+ if (max_sge < RPCRDMA_MIN_SEND_SGES) {
+ pr_warn("rpcrdma: HCA provides only %d send SGEs\n", max_sge);
+ return -ENOMEM;
+ }
+ ia->ri_max_send_sges = max_sge;
+
+ rc = ia->ri_ops->ro_open(ia, ep, cdata);
+ if (rc)
+ return rc;
+
+ ep->rep_attr.event_handler = rpcrdma_qp_async_error_upcall;
+ ep->rep_attr.qp_context = ep;
+ ep->rep_attr.srq = NULL;
+ ep->rep_attr.cap.max_send_sge = max_sge;
+ ep->rep_attr.cap.max_recv_sge = 1;
+ ep->rep_attr.cap.max_inline_data = 0;
+ ep->rep_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
+ ep->rep_attr.qp_type = IB_QPT_RC;
+ ep->rep_attr.port_num = ~0;
+
+ dprintk("RPC: %s: requested max: dtos: send %d recv %d; "
+ "iovs: send %d recv %d\n",
+ __func__,
+ ep->rep_attr.cap.max_send_wr,
+ ep->rep_attr.cap.max_recv_wr,
+ ep->rep_attr.cap.max_send_sge,
+ ep->rep_attr.cap.max_recv_sge);
+
+ /* set trigger for requesting send completion */
+ ep->rep_send_batch = min_t(unsigned int, RPCRDMA_MAX_SEND_BATCH,
+ cdata->max_requests >> 2);
+ ep->rep_send_count = ep->rep_send_batch;
+ init_waitqueue_head(&ep->rep_connect_wait);
+ INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
+
+ sendcq = ib_alloc_cq(ia->ri_device, NULL,
+ ep->rep_attr.cap.max_send_wr + 1,
+ 1, IB_POLL_WORKQUEUE);
+ if (IS_ERR(sendcq)) {
+ rc = PTR_ERR(sendcq);
+ dprintk("RPC: %s: failed to create send CQ: %i\n",
+ __func__, rc);
+ goto out1;
+ }
+
+ recvcq = ib_alloc_cq(ia->ri_device, NULL,
+ ep->rep_attr.cap.max_recv_wr + 1,
+ 0, IB_POLL_WORKQUEUE);
+ if (IS_ERR(recvcq)) {
+ rc = PTR_ERR(recvcq);
+ dprintk("RPC: %s: failed to create recv CQ: %i\n",
+ __func__, rc);
+ goto out2;
+ }
+
+ ep->rep_attr.send_cq = sendcq;
+ ep->rep_attr.recv_cq = recvcq;
+
+ /* Initialize cma parameters */
+ memset(&ep->rep_remote_cma, 0, sizeof(ep->rep_remote_cma));
+
+ /* Prepare RDMA-CM private message */
+ pmsg->cp_magic = rpcrdma_cmp_magic;
+ pmsg->cp_version = RPCRDMA_CMP_VERSION;
+ pmsg->cp_flags |= ia->ri_ops->ro_send_w_inv_ok;
+ pmsg->cp_send_size = rpcrdma_encode_buffer_size(cdata->inline_wsize);
+ pmsg->cp_recv_size = rpcrdma_encode_buffer_size(cdata->inline_rsize);
+ ep->rep_remote_cma.private_data = pmsg;
+ ep->rep_remote_cma.private_data_len = sizeof(*pmsg);
+
+ /* Client offers RDMA Read but does not initiate */
+ ep->rep_remote_cma.initiator_depth = 0;
+ ep->rep_remote_cma.responder_resources =
+ min_t(int, U8_MAX, ia->ri_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->rep_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->rep_remote_cma.flow_control = 0;
+ ep->rep_remote_cma.rnr_retry_count = 0;
+
+ return 0;
+
+out2:
+ ib_free_cq(sendcq);
+out1:
+ return rc;
+}
+
+/*
+ * rpcrdma_ep_destroy
+ *
+ * Disconnect and destroy endpoint. After this, the only
+ * valid operations on the ep are to free it (if dynamically
+ * allocated) or re-create it.
+ */
+void
+rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
+{
+ cancel_delayed_work_sync(&ep->rep_connect_worker);
+
+ if (ia->ri_id && ia->ri_id->qp) {
+ rpcrdma_ep_disconnect(ep, ia);
+ rdma_destroy_qp(ia->ri_id);
+ ia->ri_id->qp = NULL;
+ }
+
+ if (ep->rep_attr.recv_cq)
+ ib_free_cq(ep->rep_attr.recv_cq);
+ if (ep->rep_attr.send_cq)
+ ib_free_cq(ep->rep_attr.send_cq);
+}
+
+/* Re-establish a connection after a device removal event.
+ * Unlike a normal reconnection, a fresh PD and a new set
+ * of MRs and buffers is needed.
+ */
+static int
+rpcrdma_ep_recreate_xprt(struct rpcrdma_xprt *r_xprt,
+ struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
+{
+ int rc, err;
+
+ trace_xprtrdma_reinsert(r_xprt);
+
+ rc = -EHOSTUNREACH;
+ if (rpcrdma_ia_open(r_xprt))
+ goto out1;
+
+ rc = -ENOMEM;
+ err = rpcrdma_ep_create(ep, ia, &r_xprt->rx_data);
+ if (err) {
+ pr_err("rpcrdma: rpcrdma_ep_create returned %d\n", err);
+ goto out2;
+ }
+
+ rc = -ENETUNREACH;
+ err = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
+ if (err) {
+ pr_err("rpcrdma: rdma_create_qp returned %d\n", err);
+ goto out3;
+ }
+
+ rpcrdma_mrs_create(r_xprt);
+ return 0;
+
+out3:
+ rpcrdma_ep_destroy(ep, ia);
+out2:
+ rpcrdma_ia_close(ia);
+out1:
+ return rc;
+}
+
+static int
+rpcrdma_ep_reconnect(struct rpcrdma_xprt *r_xprt, struct rpcrdma_ep *ep,
+ struct rpcrdma_ia *ia)
+{
+ struct rdma_cm_id *id, *old;
+ int err, rc;
+
+ trace_xprtrdma_reconnect(r_xprt);
+
+ rpcrdma_ep_disconnect(ep, ia);
+
+ rc = -EHOSTUNREACH;
+ id = rpcrdma_create_id(r_xprt, ia);
+ if (IS_ERR(id))
+ goto out;
+
+ /* As long as the new ID points to the same device as the
+ * old ID, we can reuse the transport's existing PD and all
+ * previously allocated MRs. Also, the same device means
+ * the transport's previous DMA mappings are still valid.
+ *
+ * This is a sanity check only. There should be no way these
+ * point to two different devices here.
+ */
+ old = id;
+ rc = -ENETUNREACH;
+ if (ia->ri_device != id->device) {
+ pr_err("rpcrdma: can't reconnect on different device!\n");
+ goto out_destroy;
+ }
+
+ err = rdma_create_qp(id, ia->ri_pd, &ep->rep_attr);
+ if (err) {
+ dprintk("RPC: %s: rdma_create_qp returned %d\n",
+ __func__, err);
+ goto out_destroy;
+ }
+
+ /* Atomically replace the transport's ID and QP. */
+ rc = 0;
+ old = ia->ri_id;
+ ia->ri_id = id;
+ rdma_destroy_qp(old);
+
+out_destroy:
+ rdma_destroy_id(old);
+out:
+ return rc;
+}
+
+/*
+ * Connect unconnected endpoint.
+ */
+int
+rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
+{
+ struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
+ rx_ia);
+ int rc;
+
+retry:
+ switch (ep->rep_connected) {
+ case 0:
+ dprintk("RPC: %s: connecting...\n", __func__);
+ rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
+ if (rc) {
+ dprintk("RPC: %s: rdma_create_qp failed %i\n",
+ __func__, rc);
+ rc = -ENETUNREACH;
+ goto out_noupdate;
+ }
+ break;
+ case -ENODEV:
+ rc = rpcrdma_ep_recreate_xprt(r_xprt, ep, ia);
+ if (rc)
+ goto out_noupdate;
+ break;
+ default:
+ rc = rpcrdma_ep_reconnect(r_xprt, ep, ia);
+ if (rc)
+ goto out;
+ }
+
+ ep->rep_connected = 0;
+ rpcrdma_post_recvs(r_xprt, true);
+
+ rc = rdma_connect(ia->ri_id, &ep->rep_remote_cma);
+ if (rc) {
+ dprintk("RPC: %s: rdma_connect() failed with %i\n",
+ __func__, rc);
+ goto out;
+ }
+
+ wait_event_interruptible(ep->rep_connect_wait, ep->rep_connected != 0);
+ if (ep->rep_connected <= 0) {
+ if (ep->rep_connected == -EAGAIN)
+ goto retry;
+ rc = ep->rep_connected;
+ goto out;
+ }
+
+ dprintk("RPC: %s: connected\n", __func__);
+
+out:
+ if (rc)
+ ep->rep_connected = rc;
+
+out_noupdate:
+ return rc;
+}
+
+/*
+ * rpcrdma_ep_disconnect
+ *
+ * This is separate from destroy to facilitate the ability
+ * to reconnect without recreating the endpoint.
+ *
+ * This call is not reentrant, and must not be made in parallel
+ * on the same endpoint.
+ */
+void
+rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
+{
+ int rc;
+
+ rc = rdma_disconnect(ia->ri_id);
+ if (!rc)
+ /* returns without wait if not connected */
+ wait_event_interruptible(ep->rep_connect_wait,
+ ep->rep_connected != 1);
+ else
+ ep->rep_connected = rc;
+ trace_xprtrdma_disconnect(container_of(ep, struct rpcrdma_xprt,
+ rx_ep), rc);
+
+ ib_drain_qp(ia->ri_id->qp);
+}
+
+/* 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 ib_drain_qp has flushed all remaining Send
+ * requests.
+ */
+static void rpcrdma_sendctxs_destroy(struct rpcrdma_buffer *buf)
+{
+ unsigned long i;
+
+ for (i = 0; i <= buf->rb_sc_last; i++)
+ kfree(buf->rb_sc_ctxs[i]);
+ kfree(buf->rb_sc_ctxs);
+}
+
+static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ia *ia)
+{
+ struct rpcrdma_sendctx *sc;
+
+ sc = kzalloc(sizeof(*sc) +
+ ia->ri_max_send_sges * sizeof(struct ib_sge),
+ GFP_KERNEL);
+ if (!sc)
+ return NULL;
+
+ sc->sc_wr.wr_cqe = &sc->sc_cqe;
+ sc->sc_wr.sg_list = sc->sc_sges;
+ sc->sc_wr.opcode = IB_WR_SEND;
+ 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 = buf->rb_max_requests + RPCRDMA_MAX_BC_REQUESTS;
+ dprintk("RPC: %s: allocating %lu send_ctxs\n", __func__, i);
+ 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_ia);
+ if (!sc)
+ goto out_destroy;
+
+ sc->sc_xprt = r_xprt;
+ buf->rb_sc_ctxs[i] = sc;
+ }
+ buf->rb_flags = 0;
+
+ return 0;
+
+out_destroy:
+ rpcrdma_sendctxs_destroy(buf);
+ return -ENOMEM;
+}
+
+/* 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
+ * @buf: transport buffers from which to acquire an unused context
+ *
+ * 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 rpcrdma_buffer),
+ * and provides an effective memory barrier that flushes the new value
+ * of rb_sc_head.
+ */
+struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_buffer *buf)
+{
+ struct rpcrdma_xprt *r_xprt;
+ 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.
+ */
+ set_bit(RPCRDMA_BUF_F_EMPTY_SCQ, &buf->rb_flags);
+ r_xprt = container_of(buf, struct rpcrdma_xprt, rx_buf);
+ r_xprt->rx_stats.empty_sendctx_q++;
+ return NULL;
+}
+
+/**
+ * rpcrdma_sendctx_put_locked - Release a send context
+ * @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 rpcrdma_buffer).
+ */
+static void
+rpcrdma_sendctx_put_locked(struct rpcrdma_sendctx *sc)
+{
+ struct rpcrdma_buffer *buf = &sc->sc_xprt->rx_buf;
+ unsigned long next_tail;
+
+ /* Unmap SGEs of previously completed by 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_unmap_sendctx(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);
+
+ if (test_and_clear_bit(RPCRDMA_BUF_F_EMPTY_SCQ, &buf->rb_flags)) {
+ smp_mb__after_atomic();
+ xprt_write_space(&sc->sc_xprt->rx_xprt);
+ }
+}
+
+static void
+rpcrdma_mr_recovery_worker(struct work_struct *work)
+{
+ struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
+ rb_recovery_worker.work);
+ struct rpcrdma_mr *mr;
+
+ spin_lock(&buf->rb_recovery_lock);
+ while (!list_empty(&buf->rb_stale_mrs)) {
+ mr = rpcrdma_mr_pop(&buf->rb_stale_mrs);
+ spin_unlock(&buf->rb_recovery_lock);
+
+ trace_xprtrdma_recover_mr(mr);
+ mr->mr_xprt->rx_ia.ri_ops->ro_recover_mr(mr);
+
+ spin_lock(&buf->rb_recovery_lock);
+ }
+ spin_unlock(&buf->rb_recovery_lock);
+}
+
+void
+rpcrdma_mr_defer_recovery(struct rpcrdma_mr *mr)
+{
+ struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
+ struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+
+ spin_lock(&buf->rb_recovery_lock);
+ rpcrdma_mr_push(mr, &buf->rb_stale_mrs);
+ spin_unlock(&buf->rb_recovery_lock);
+
+ schedule_delayed_work(&buf->rb_recovery_worker, 0);
+}
+
+static void
+rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt)
+{
+ struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+ struct rpcrdma_ia *ia = &r_xprt->rx_ia;
+ unsigned int count;
+ LIST_HEAD(free);
+ LIST_HEAD(all);
+
+ for (count = 0; count < 3; count++) {
+ struct rpcrdma_mr *mr;
+ int rc;
+
+ mr = kzalloc(sizeof(*mr), GFP_KERNEL);
+ if (!mr)
+ break;
+
+ rc = ia->ri_ops->ro_init_mr(ia, mr);
+ if (rc) {
+ kfree(mr);
+ break;
+ }
+
+ mr->mr_xprt = r_xprt;
+
+ list_add(&mr->mr_list, &free);
+ list_add(&mr->mr_all, &all);
+ }
+
+ spin_lock(&buf->rb_mrlock);
+ list_splice(&free, &buf->rb_mrs);
+ list_splice(&all, &buf->rb_all);
+ r_xprt->rx_stats.mrs_allocated += count;
+ spin_unlock(&buf->rb_mrlock);
+ trace_xprtrdma_createmrs(r_xprt, count);
+
+ xprt_write_space(&r_xprt->rx_xprt);
+}
+
+static void
+rpcrdma_mr_refresh_worker(struct work_struct *work)
+{
+ struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
+ rb_refresh_worker.work);
+ struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
+ rx_buf);
+
+ rpcrdma_mrs_create(r_xprt);
+}
+
+struct rpcrdma_req *
+rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
+{
+ struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
+ struct rpcrdma_regbuf *rb;
+ struct rpcrdma_req *req;
+
+ req = kzalloc(sizeof(*req), GFP_KERNEL);
+ if (req == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ rb = rpcrdma_alloc_regbuf(RPCRDMA_HDRBUF_SIZE,
+ DMA_TO_DEVICE, GFP_KERNEL);
+ if (IS_ERR(rb)) {
+ kfree(req);
+ return ERR_PTR(-ENOMEM);
+ }
+ req->rl_rdmabuf = rb;
+ xdr_buf_init(&req->rl_hdrbuf, rb->rg_base, rdmab_length(rb));
+ req->rl_buffer = buffer;
+ INIT_LIST_HEAD(&req->rl_registered);
+
+ spin_lock(&buffer->rb_reqslock);
+ list_add(&req->rl_all, &buffer->rb_allreqs);
+ spin_unlock(&buffer->rb_reqslock);
+ return req;
+}
+
+static int
+rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt, bool temp)
+{
+ struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
+ struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+ struct rpcrdma_rep *rep;
+ int rc;
+
+ rc = -ENOMEM;
+ rep = kzalloc(sizeof(*rep), GFP_KERNEL);
+ if (rep == NULL)
+ goto out;
+
+ rep->rr_rdmabuf = rpcrdma_alloc_regbuf(cdata->inline_rsize,
+ DMA_FROM_DEVICE, GFP_KERNEL);
+ if (IS_ERR(rep->rr_rdmabuf)) {
+ rc = PTR_ERR(rep->rr_rdmabuf);
+ goto out_free;
+ }
+ xdr_buf_init(&rep->rr_hdrbuf, rep->rr_rdmabuf->rg_base,
+ rdmab_length(rep->rr_rdmabuf));
+
+ rep->rr_cqe.done = rpcrdma_wc_receive;
+ rep->rr_rxprt = r_xprt;
+ INIT_WORK(&rep->rr_work, rpcrdma_deferred_completion);
+ 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_list, &buf->rb_recv_bufs);
+ spin_unlock(&buf->rb_lock);
+ return 0;
+
+out_free:
+ kfree(rep);
+out:
+ dprintk("RPC: %s: reply buffer %d alloc failed\n",
+ __func__, rc);
+ return rc;
+}
+
+int
+rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
+{
+ struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+ int i, rc;
+
+ buf->rb_max_requests = r_xprt->rx_data.max_requests;
+ buf->rb_bc_srv_max_requests = 0;
+ spin_lock_init(&buf->rb_mrlock);
+ spin_lock_init(&buf->rb_lock);
+ spin_lock_init(&buf->rb_recovery_lock);
+ INIT_LIST_HEAD(&buf->rb_mrs);
+ INIT_LIST_HEAD(&buf->rb_all);
+ INIT_LIST_HEAD(&buf->rb_stale_mrs);
+ INIT_DELAYED_WORK(&buf->rb_refresh_worker,
+ rpcrdma_mr_refresh_worker);
+ INIT_DELAYED_WORK(&buf->rb_recovery_worker,
+ rpcrdma_mr_recovery_worker);
+
+ rpcrdma_mrs_create(r_xprt);
+
+ INIT_LIST_HEAD(&buf->rb_send_bufs);
+ INIT_LIST_HEAD(&buf->rb_allreqs);
+ spin_lock_init(&buf->rb_reqslock);
+ for (i = 0; i < buf->rb_max_requests; i++) {
+ struct rpcrdma_req *req;
+
+ req = rpcrdma_create_req(r_xprt);
+ if (IS_ERR(req)) {
+ dprintk("RPC: %s: request buffer %d alloc"
+ " failed\n", __func__, i);
+ rc = PTR_ERR(req);
+ goto out;
+ }
+ list_add(&req->rl_list, &buf->rb_send_bufs);
+ }
+
+ buf->rb_credits = 1;
+ buf->rb_posted_receives = 0;
+ INIT_LIST_HEAD(&buf->rb_recv_bufs);
+
+ rc = rpcrdma_sendctxs_create(r_xprt);
+ if (rc)
+ goto out;
+
+ return 0;
+out:
+ rpcrdma_buffer_destroy(buf);
+ return rc;
+}
+
+static void
+rpcrdma_destroy_rep(struct rpcrdma_rep *rep)
+{
+ rpcrdma_free_regbuf(rep->rr_rdmabuf);
+ kfree(rep);
+}
+
+void
+rpcrdma_destroy_req(struct rpcrdma_req *req)
+{
+ rpcrdma_free_regbuf(req->rl_recvbuf);
+ rpcrdma_free_regbuf(req->rl_sendbuf);
+ rpcrdma_free_regbuf(req->rl_rdmabuf);
+ kfree(req);
+}
+
+static void
+rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf)
+{
+ struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
+ rx_buf);
+ struct rpcrdma_ia *ia = rdmab_to_ia(buf);
+ struct rpcrdma_mr *mr;
+ unsigned int count;
+
+ count = 0;
+ spin_lock(&buf->rb_mrlock);
+ while (!list_empty(&buf->rb_all)) {
+ mr = list_entry(buf->rb_all.next, struct rpcrdma_mr, mr_all);
+ list_del(&mr->mr_all);
+
+ spin_unlock(&buf->rb_mrlock);
+
+ /* Ensure MW is not on any rl_registered list */
+ if (!list_empty(&mr->mr_list))
+ list_del(&mr->mr_list);
+
+ ia->ri_ops->ro_release_mr(mr);
+ count++;
+ spin_lock(&buf->rb_mrlock);
+ }
+ spin_unlock(&buf->rb_mrlock);
+ r_xprt->rx_stats.mrs_allocated = 0;
+
+ dprintk("RPC: %s: released %u MRs\n", __func__, count);
+}
+
+void
+rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
+{
+ cancel_delayed_work_sync(&buf->rb_recovery_worker);
+ cancel_delayed_work_sync(&buf->rb_refresh_worker);
+
+ rpcrdma_sendctxs_destroy(buf);
+
+ while (!list_empty(&buf->rb_recv_bufs)) {
+ struct rpcrdma_rep *rep;
+
+ rep = list_first_entry(&buf->rb_recv_bufs,
+ struct rpcrdma_rep, rr_list);
+ list_del(&rep->rr_list);
+ rpcrdma_destroy_rep(rep);
+ }
+
+ spin_lock(&buf->rb_reqslock);
+ while (!list_empty(&buf->rb_allreqs)) {
+ struct rpcrdma_req *req;
+
+ req = list_first_entry(&buf->rb_allreqs,
+ struct rpcrdma_req, rl_all);
+ list_del(&req->rl_all);
+
+ spin_unlock(&buf->rb_reqslock);
+ rpcrdma_destroy_req(req);
+ spin_lock(&buf->rb_reqslock);
+ }
+ spin_unlock(&buf->rb_reqslock);
+
+ rpcrdma_mrs_destroy(buf);
+}
+
+/**
+ * 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 = NULL;
+
+ spin_lock(&buf->rb_mrlock);
+ if (!list_empty(&buf->rb_mrs))
+ mr = rpcrdma_mr_pop(&buf->rb_mrs);
+ spin_unlock(&buf->rb_mrlock);
+
+ if (!mr)
+ goto out_nomrs;
+ return mr;
+
+out_nomrs:
+ trace_xprtrdma_nomrs(r_xprt);
+ if (r_xprt->rx_ep.rep_connected != -ENODEV)
+ schedule_delayed_work(&buf->rb_refresh_worker, 0);
+
+ /* Allow the reply handler and refresh worker to run */
+ cond_resched();
+
+ return NULL;
+}
+
+static void
+__rpcrdma_mr_put(struct rpcrdma_buffer *buf, struct rpcrdma_mr *mr)
+{
+ spin_lock(&buf->rb_mrlock);
+ rpcrdma_mr_push(mr, &buf->rb_mrs);
+ spin_unlock(&buf->rb_mrlock);
+}
+
+/**
+ * rpcrdma_mr_put - Release an rpcrdma_mr object
+ * @mr: object to release
+ *
+ */
+void
+rpcrdma_mr_put(struct rpcrdma_mr *mr)
+{
+ __rpcrdma_mr_put(&mr->mr_xprt->rx_buf, mr);
+}
+
+/**
+ * rpcrdma_mr_unmap_and_put - DMA unmap an MR and release it
+ * @mr: object to release
+ *
+ */
+void
+rpcrdma_mr_unmap_and_put(struct rpcrdma_mr *mr)
+{
+ struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
+
+ trace_xprtrdma_dma_unmap(mr);
+ ib_dma_unmap_sg(r_xprt->rx_ia.ri_device,
+ mr->mr_sg, mr->mr_nents, mr->mr_dir);
+ __rpcrdma_mr_put(&r_xprt->rx_buf, 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
+ * @req: object to return
+ *
+ */
+void
+rpcrdma_buffer_put(struct rpcrdma_req *req)
+{
+ struct rpcrdma_buffer *buffers = req->rl_buffer;
+ struct rpcrdma_rep *rep = req->rl_reply;
+
+ req->rl_reply = NULL;
+
+ spin_lock(&buffers->rb_lock);
+ list_add(&req->rl_list, &buffers->rb_send_bufs);
+ if (rep) {
+ if (!rep->rr_temp) {
+ list_add(&rep->rr_list, &buffers->rb_recv_bufs);
+ rep = NULL;
+ }
+ }
+ spin_unlock(&buffers->rb_lock);
+ if (rep)
+ rpcrdma_destroy_rep(rep);
+}
+
+/*
+ * Put reply buffers back into pool when not attached to
+ * request. This happens in error conditions.
+ */
+void
+rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
+{
+ struct rpcrdma_buffer *buffers = &rep->rr_rxprt->rx_buf;
+
+ if (!rep->rr_temp) {
+ spin_lock(&buffers->rb_lock);
+ list_add(&rep->rr_list, &buffers->rb_recv_bufs);
+ spin_unlock(&buffers->rb_lock);
+ } else {
+ rpcrdma_destroy_rep(rep);
+ }
+}
+
+/**
+ * rpcrdma_alloc_regbuf - allocate and DMA-map memory for SEND/RECV buffers
+ * @size: size of buffer to be allocated, in bytes
+ * @direction: direction of data movement
+ * @flags: GFP flags
+ *
+ * Returns an ERR_PTR, or a pointer to a regbuf, a buffer that
+ * can be persistently DMA-mapped for I/O.
+ *
+ * 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 ro_map.
+ */
+struct rpcrdma_regbuf *
+rpcrdma_alloc_regbuf(size_t size, enum dma_data_direction direction,
+ gfp_t flags)
+{
+ struct rpcrdma_regbuf *rb;
+
+ rb = kmalloc(sizeof(*rb) + size, flags);
+ if (rb == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ rb->rg_device = NULL;
+ rb->rg_direction = direction;
+ rb->rg_iov.length = size;
+
+ return rb;
+}
+
+/**
+ * __rpcrdma_map_regbuf - DMA-map a regbuf
+ * @ia: controlling rpcrdma_ia
+ * @rb: regbuf to be mapped
+ */
+bool
+__rpcrdma_dma_map_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
+{
+ struct ib_device *device = ia->ri_device;
+
+ if (rb->rg_direction == DMA_NONE)
+ return false;
+
+ rb->rg_iov.addr = ib_dma_map_single(device,
+ (void *)rb->rg_base,
+ rdmab_length(rb),
+ rb->rg_direction);
+ if (ib_dma_mapping_error(device, rdmab_addr(rb)))
+ return false;
+
+ rb->rg_device = device;
+ rb->rg_iov.lkey = ia->ri_pd->local_dma_lkey;
+ return true;
+}
+
+static void
+rpcrdma_dma_unmap_regbuf(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;
+}
+
+/**
+ * rpcrdma_free_regbuf - deregister and free registered buffer
+ * @rb: regbuf to be deregistered and freed
+ */
+void
+rpcrdma_free_regbuf(struct rpcrdma_regbuf *rb)
+{
+ rpcrdma_dma_unmap_regbuf(rb);
+ kfree(rb);
+}
+
+/*
+ * Prepost any receive buffer, then post send.
+ *
+ * Receive buffer is donated to hardware, reclaimed upon recv completion.
+ */
+int
+rpcrdma_ep_post(struct rpcrdma_ia *ia,
+ struct rpcrdma_ep *ep,
+ struct rpcrdma_req *req)
+{
+ struct ib_send_wr *send_wr = &req->rl_sendctx->sc_wr;
+ int rc;
+
+ if (!ep->rep_send_count ||
+ test_bit(RPCRDMA_REQ_F_TX_RESOURCES, &req->rl_flags)) {
+ send_wr->send_flags |= IB_SEND_SIGNALED;
+ ep->rep_send_count = ep->rep_send_batch;
+ } else {
+ send_wr->send_flags &= ~IB_SEND_SIGNALED;
+ --ep->rep_send_count;
+ }
+
+ rc = ia->ri_ops->ro_send(ia, req);
+ trace_xprtrdma_post_send(req, rc);
+ if (rc)
+ return -ENOTCONN;
+ return 0;
+}
+
+/**
+ * rpcrdma_post_recvs - Maybe post some Receive buffers
+ * @r_xprt: controlling transport
+ * @temp: when true, allocate temp rpcrdma_rep objects
+ *
+ */
+void
+rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp)
+{
+ struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+ struct ib_recv_wr *wr, *bad_wr;
+ int needed, count, rc;
+
+ needed = buf->rb_credits + (buf->rb_bc_srv_max_requests << 1);
+ if (buf->rb_posted_receives > needed)
+ return;
+ needed -= buf->rb_posted_receives;
+
+ count = 0;
+ wr = NULL;
+ while (needed) {
+ struct rpcrdma_regbuf *rb;
+ struct rpcrdma_rep *rep;
+
+ spin_lock(&buf->rb_lock);
+ rep = list_first_entry_or_null(&buf->rb_recv_bufs,
+ struct rpcrdma_rep, rr_list);
+ if (likely(rep))
+ list_del(&rep->rr_list);
+ spin_unlock(&buf->rb_lock);
+ if (!rep) {
+ if (rpcrdma_create_rep(r_xprt, temp))
+ break;
+ continue;
+ }
+
+ rb = rep->rr_rdmabuf;
+ if (!rpcrdma_regbuf_is_mapped(rb)) {
+ if (!__rpcrdma_dma_map_regbuf(&r_xprt->rx_ia, rb)) {
+ rpcrdma_recv_buffer_put(rep);
+ break;
+ }
+ }
+
+ trace_xprtrdma_post_recv(rep->rr_recv_wr.wr_cqe);
+ rep->rr_recv_wr.next = wr;
+ wr = &rep->rr_recv_wr;
+ ++count;
+ --needed;
+ }
+ if (!count)
+ return;
+
+ rc = ib_post_recv(r_xprt->rx_ia.ri_id->qp, wr,
+ (const struct ib_recv_wr **)&bad_wr);
+ if (rc) {
+ for (wr = bad_wr; wr; wr = wr->next) {
+ struct rpcrdma_rep *rep;
+
+ rep = container_of(wr, struct rpcrdma_rep, rr_recv_wr);
+ rpcrdma_recv_buffer_put(rep);
+ --count;
+ }
+ }
+ buf->rb_posted_receives += count;
+ trace_xprtrdma_post_recvs(r_xprt, count, rc);
+}