verbs.c 40.7 KB
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/*
C
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 * Copyright (c) 2014-2017 Oracle.  All rights reserved.
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 * 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.
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 */

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/*
 * verbs.c
 *
 * Encapsulates the major functions managing:
 *  o adapters
 *  o endpoints
 *  o connections
 *  o buffer memory
 */

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#include <linux/interrupt.h>
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#include <linux/slab.h>
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#include <linux/sunrpc/addr.h>
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#include <linux/sunrpc/svc_rdma.h>
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#include <asm-generic/barrier.h>
57
#include <asm/bitops.h>
58

59
#include <rdma/ib_cm.h>
60

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#include "xprt_rdma.h"

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/*
 * Globals/Macros
 */

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#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
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# define RPCDBG_FACILITY	RPCDBG_TRANS
#endif

/*
 * internal functions
 */
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static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt);
static void rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf);
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static void rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb);
77

78
struct workqueue_struct *rpcrdma_receive_wq __read_mostly;
79

80 81
int
rpcrdma_alloc_wq(void)
82
{
83
	struct workqueue_struct *recv_wq;
84

85
	recv_wq = alloc_workqueue("xprtrdma_receive",
86
				  WQ_MEM_RECLAIM | WQ_HIGHPRI,
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				  0);
	if (!recv_wq)
		return -ENOMEM;
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91 92
	rpcrdma_receive_wq = recv_wq;
	return 0;
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}

95 96
void
rpcrdma_destroy_wq(void)
97
{
98
	struct workqueue_struct *wq;
99

100 101 102 103 104
	if (rpcrdma_receive_wq) {
		wq = rpcrdma_receive_wq;
		rpcrdma_receive_wq = NULL;
		destroy_workqueue(wq);
	}
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}

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static void
rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
{
	struct rpcrdma_ep *ep = context;

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	pr_err("rpcrdma: %s on device %s ep %p\n",
	       ib_event_msg(event->event), event->device->name, context);

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	if (ep->rep_connected == 1) {
		ep->rep_connected = -EIO;
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		rpcrdma_conn_func(ep);
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		wake_up_all(&ep->rep_connect_wait);
	}
}

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/**
 * rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC
 * @cq:	completion queue (ignored)
 * @wc:	completed WR
 *
127 128
 */
static void
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rpcrdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
130
{
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	struct ib_cqe *cqe = wc->wr_cqe;
	struct rpcrdma_sendctx *sc =
		container_of(cqe, struct rpcrdma_sendctx, sc_cqe);

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	/* WARNING: Only wr_cqe and status are reliable at this point */
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	trace_xprtrdma_wc_send(sc, wc);
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	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);
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	rpcrdma_sendctx_put_locked(sc);
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}
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145
/**
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 * rpcrdma_wc_receive - Invoked by RDMA provider for each polled Receive WC
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 * @cq:	completion queue (ignored)
 * @wc:	completed WR
 *
 */
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static void
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rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
153
{
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	struct ib_cqe *cqe = wc->wr_cqe;
	struct rpcrdma_rep *rep = container_of(cqe, struct rpcrdma_rep,
					       rr_cqe);
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	/* WARNING: Only wr_id and status are reliable at this point */
	if (wc->status != IB_WC_SUCCESS)
		goto out_fail;
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	/* status == SUCCESS means all fields in wc are trustworthy */
	dprintk("RPC:       %s: rep %p opcode 'recv', length %u: success\n",
		__func__, rep, wc->byte_len);

166
	rpcrdma_set_xdrlen(&rep->rr_hdrbuf, wc->byte_len);
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	rep->rr_wc_flags = wc->wc_flags;
	rep->rr_inv_rkey = wc->ex.invalidate_rkey;

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	ib_dma_sync_single_for_cpu(rdmab_device(rep->rr_rdmabuf),
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				   rdmab_addr(rep->rr_rdmabuf),
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				   wc->byte_len, DMA_FROM_DEVICE);
173

174
out_schedule:
175
	rpcrdma_reply_handler(rep);
176
	return;
177

178 179
out_fail:
	if (wc->status != IB_WC_WR_FLUSH_ERR)
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		pr_err("rpcrdma: Recv: %s (%u/0x%x)\n",
		       ib_wc_status_msg(wc->status),
		       wc->status, wc->vendor_err);
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	rpcrdma_set_xdrlen(&rep->rr_hdrbuf, 0);
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	goto out_schedule;
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}

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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;

195
	/* Default settings for RPC-over-RDMA Version One */
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	r_xprt->rx_ia.ri_implicit_roundup = xprt_rdma_pad_optimize;
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	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) {
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		r_xprt->rx_ia.ri_implicit_roundup = true;
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		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;
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	dprintk("RPC:       %s: max send %u, max recv %u\n",
		__func__, cdata->inline_wsize, cdata->inline_rsize);
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	rpcrdma_set_max_header_sizes(r_xprt);
}

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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;

	switch (event->event) {
	case RDMA_CM_EVENT_ADDR_RESOLVED:
	case RDMA_CM_EVENT_ROUTE_RESOLVED:
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		ia->ri_async_rc = 0;
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		complete(&ia->ri_done);
		break;
	case RDMA_CM_EVENT_ADDR_ERROR:
		ia->ri_async_rc = -EHOSTUNREACH;
		dprintk("RPC:       %s: CM address resolution error, ep 0x%p\n",
			__func__, ep);
		complete(&ia->ri_done);
		break;
	case RDMA_CM_EVENT_ROUTE_ERROR:
		ia->ri_async_rc = -ENETUNREACH;
		dprintk("RPC:       %s: CM route resolution error, ep 0x%p\n",
			__func__, ep);
		complete(&ia->ri_done);
		break;
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	case RDMA_CM_EVENT_DEVICE_REMOVAL:
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
245
		pr_info("rpcrdma: removing device %s for %s:%s\n",
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			ia->ri_device->name,
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			rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt));
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#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_pd = NULL;
		ia->ri_device = NULL;
		/* Return 1 to ensure the core destroys the id. */
		return 1;
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	case RDMA_CM_EVENT_ESTABLISHED:
		connstate = 1;
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		rpcrdma_update_connect_private(xprt, &event->param.conn);
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		goto connected;
	case RDMA_CM_EVENT_CONNECT_ERROR:
		connstate = -ENOTCONN;
		goto connected;
	case RDMA_CM_EVENT_UNREACHABLE:
		connstate = -ENETDOWN;
		goto connected;
	case RDMA_CM_EVENT_REJECTED:
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		dprintk("rpcrdma: connection to %s:%s rejected: %s\n",
			rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt),
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			rdma_reject_msg(id, event->status));
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		connstate = -ECONNREFUSED;
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		if (event->status == IB_CM_REJ_STALE_CONN)
			connstate = -EAGAIN;
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		goto connected;
	case RDMA_CM_EVENT_DISCONNECTED:
		connstate = -ECONNABORTED;
connected:
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		xprt->rx_buf.rb_credits = 1;
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		ep->rep_connected = connstate;
282
		rpcrdma_conn_func(ep);
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		wake_up_all(&ep->rep_connect_wait);
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		/*FALLTHROUGH*/
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	default:
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		dprintk("RPC:       %s: %s:%s on %s/%s (ep 0x%p): %s\n",
			__func__,
			rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt),
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			ia->ri_device->name, ia->ri_ops->ro_displayname,
			ep, rdma_event_msg(event->event));
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		break;
	}

	return 0;
}

static struct rdma_cm_id *
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rpcrdma_create_id(struct rpcrdma_xprt *xprt, struct rpcrdma_ia *ia)
299
{
300
	unsigned long wtimeout = msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1;
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	struct rdma_cm_id *id;
	int rc;

304
	init_completion(&ia->ri_done);
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	init_completion(&ia->ri_remove_done);
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	id = rdma_create_id(&init_net, rpcrdma_conn_upcall, xprt, RDMA_PS_TCP,
			    IB_QPT_RC);
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	if (IS_ERR(id)) {
		rc = PTR_ERR(id);
		dprintk("RPC:       %s: rdma_create_id() failed %i\n",
			__func__, rc);
		return id;
	}

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	ia->ri_async_rc = -ETIMEDOUT;
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	rc = rdma_resolve_addr(id, NULL,
			       (struct sockaddr *)&xprt->rx_xprt.addr,
			       RDMA_RESOLVE_TIMEOUT);
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	if (rc) {
		dprintk("RPC:       %s: rdma_resolve_addr() failed %i\n",
			__func__, rc);
		goto out;
	}
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	rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
	if (rc < 0) {
		dprintk("RPC:       %s: wait() exited: %i\n",
			__func__, rc);
		goto out;
	}
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	rc = ia->ri_async_rc;
	if (rc)
		goto out;

336
	ia->ri_async_rc = -ETIMEDOUT;
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	rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
	if (rc) {
		dprintk("RPC:       %s: rdma_resolve_route() failed %i\n",
			__func__, rc);
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		goto out;
342
	}
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	rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
	if (rc < 0) {
		dprintk("RPC:       %s: wait() exited: %i\n",
			__func__, rc);
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		goto out;
348
	}
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	rc = ia->ri_async_rc;
	if (rc)
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		goto out;
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	return id;
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out:
	rdma_destroy_id(id);
	return ERR_PTR(rc);
}

/*
 * Exported functions.
 */

364 365
/**
 * rpcrdma_ia_open - Open and initialize an Interface Adapter.
366
 * @xprt: transport with IA to (re)initialize
367 368 369
 *
 * Returns 0 on success, negative errno if an appropriate
 * Interface Adapter could not be found and opened.
370 371
 */
int
372
rpcrdma_ia_open(struct rpcrdma_xprt *xprt)
373 374
{
	struct rpcrdma_ia *ia = &xprt->rx_ia;
375 376
	int rc;

377
	ia->ri_id = rpcrdma_create_id(xprt, ia);
378 379
	if (IS_ERR(ia->ri_id)) {
		rc = PTR_ERR(ia->ri_id);
380
		goto out_err;
381
	}
382
	ia->ri_device = ia->ri_id->device;
383

384
	ia->ri_pd = ib_alloc_pd(ia->ri_device, 0);
385 386
	if (IS_ERR(ia->ri_pd)) {
		rc = PTR_ERR(ia->ri_pd);
387
		pr_err("rpcrdma: ib_alloc_pd() returned %d\n", rc);
388
		goto out_err;
389 390
	}

391
	switch (xprt_rdma_memreg_strategy) {
392
	case RPCRDMA_FRWR:
393 394 395 396 397
		if (frwr_is_supported(ia)) {
			ia->ri_ops = &rpcrdma_frwr_memreg_ops;
			break;
		}
		/*FALLTHROUGH*/
398
	case RPCRDMA_MTHCAFMR:
399 400 401 402 403
		if (fmr_is_supported(ia)) {
			ia->ri_ops = &rpcrdma_fmr_memreg_ops;
			break;
		}
		/*FALLTHROUGH*/
404
	default:
405 406
		pr_err("rpcrdma: Device %s does not support memreg mode %d\n",
		       ia->ri_device->name, xprt_rdma_memreg_strategy);
407
		rc = -EINVAL;
408
		goto out_err;
409 410 411
	}

	return 0;
412

413 414
out_err:
	rpcrdma_ia_close(ia);
415 416 417
	return rc;
}

418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461
/**
 * 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);
	ib_free_cq(ep->rep_attr.send_cq);

	/* 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);
	}
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	rpcrdma_mrs_destroy(buf);
463 464 465 466 467

	/* Allow waiters to continue */
	complete(&ia->ri_remove_done);
}

468 469 470 471
/**
 * rpcrdma_ia_close - Clean up/close an IA.
 * @ia: interface adapter to close
 *
472 473 474 475 476
 */
void
rpcrdma_ia_close(struct rpcrdma_ia *ia)
{
	dprintk("RPC:       %s: entering\n", __func__);
477 478 479
	if (ia->ri_id != NULL && !IS_ERR(ia->ri_id)) {
		if (ia->ri_id->qp)
			rdma_destroy_qp(ia->ri_id);
480
		rdma_destroy_id(ia->ri_id);
481
	}
482 483
	ia->ri_id = NULL;
	ia->ri_device = NULL;
484 485 486

	/* If the pd is still busy, xprtrdma missed freeing a resource */
	if (ia->ri_pd && !IS_ERR(ia->ri_pd))
487
		ib_dealloc_pd(ia->ri_pd);
488
	ia->ri_pd = NULL;
489 490 491 492 493 494 495
}

/*
 * Create unconnected endpoint.
 */
int
rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
496
		  struct rpcrdma_create_data_internal *cdata)
497
{
498
	struct rpcrdma_connect_private *pmsg = &ep->rep_cm_private;
499
	unsigned int max_qp_wr, max_sge;
500
	struct ib_cq *sendcq, *recvcq;
501
	int rc;
502

503 504
	max_sge = min_t(unsigned int, ia->ri_device->attrs.max_sge,
			RPCRDMA_MAX_SEND_SGES);
505 506
	if (max_sge < RPCRDMA_MIN_SEND_SGES) {
		pr_warn("rpcrdma: HCA provides only %d send SGEs\n", max_sge);
507 508
		return -ENOMEM;
	}
509
	ia->ri_max_send_sges = max_sge - RPCRDMA_MIN_SEND_SGES;
510

511
	if (ia->ri_device->attrs.max_qp_wr <= RPCRDMA_BACKWARD_WRS) {
512 513 514 515
		dprintk("RPC:       %s: insufficient wqe's available\n",
			__func__);
		return -ENOMEM;
	}
516
	max_qp_wr = ia->ri_device->attrs.max_qp_wr - RPCRDMA_BACKWARD_WRS - 1;
517

518
	/* check provider's send/recv wr limits */
519 520
	if (cdata->max_requests > max_qp_wr)
		cdata->max_requests = max_qp_wr;
521 522 523 524 525

	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_wr = cdata->max_requests;
526
	ep->rep_attr.cap.max_send_wr += RPCRDMA_BACKWARD_WRS;
527
	ep->rep_attr.cap.max_send_wr += 1;	/* drain cqe */
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	rc = ia->ri_ops->ro_open(ia, ep, cdata);
	if (rc)
		return rc;
531
	ep->rep_attr.cap.max_recv_wr = cdata->max_requests;
532
	ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS;
533
	ep->rep_attr.cap.max_recv_wr += 1;	/* drain cqe */
534
	ep->rep_attr.cap.max_send_sge = max_sge;
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	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 */
550 551 552
	ep->rep_send_batch = min_t(unsigned int, RPCRDMA_MAX_SEND_BATCH,
				   cdata->max_requests >> 2);
	ep->rep_send_count = ep->rep_send_batch;
553
	init_waitqueue_head(&ep->rep_connect_wait);
554
	INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
555

556 557
	sendcq = ib_alloc_cq(ia->ri_device, NULL,
			     ep->rep_attr.cap.max_send_wr + 1,
558
			     1, IB_POLL_WORKQUEUE);
559 560 561
	if (IS_ERR(sendcq)) {
		rc = PTR_ERR(sendcq);
		dprintk("RPC:       %s: failed to create send CQ: %i\n",
562 563 564 565
			__func__, rc);
		goto out1;
	}

566 567
	recvcq = ib_alloc_cq(ia->ri_device, NULL,
			     ep->rep_attr.cap.max_recv_wr + 1,
568
			     0, IB_POLL_WORKQUEUE);
569 570 571 572 573 574 575 576 577
	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;
578 579

	/* Initialize cma parameters */
580
	memset(&ep->rep_remote_cma, 0, sizeof(ep->rep_remote_cma));
581

582 583 584
	/* Prepare RDMA-CM private message */
	pmsg->cp_magic = rpcrdma_cmp_magic;
	pmsg->cp_version = RPCRDMA_CMP_VERSION;
585
	pmsg->cp_flags |= ia->ri_ops->ro_send_w_inv_ok;
586 587 588 589
	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);
590 591

	/* Client offers RDMA Read but does not initiate */
592
	ep->rep_remote_cma.initiator_depth = 0;
593
	if (ia->ri_device->attrs.max_qp_rd_atom > 32)	/* arbitrary but <= 255 */
594 595
		ep->rep_remote_cma.responder_resources = 32;
	else
596
		ep->rep_remote_cma.responder_resources =
597
						ia->ri_device->attrs.max_qp_rd_atom;
598

599 600 601 602 603 604 605 606 607 608
	/* 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).
	 */
609 610 611 612 613 614
	ep->rep_remote_cma.flow_control = 0;
	ep->rep_remote_cma.rnr_retry_count = 0;

	return 0;

out2:
615
	ib_free_cq(sendcq);
616 617 618 619 620 621 622 623 624 625 626
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.
 */
627
void
628 629 630 631 632
rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
	dprintk("RPC:       %s: entering, connected is %d\n",
		__func__, ep->rep_connected);

633 634
	cancel_delayed_work_sync(&ep->rep_connect_worker);

635
	if (ia->ri_id->qp) {
636
		rpcrdma_ep_disconnect(ep, ia);
637 638
		rdma_destroy_qp(ia->ri_id);
		ia->ri_id->qp = NULL;
639 640
	}

641
	ib_free_cq(ep->rep_attr.recv_cq);
642
	ib_free_cq(ep->rep_attr.send_cq);
643 644
}

645 646 647 648 649 650 651 652 653 654 655 656 657
/* 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;

	pr_info("%s: r_xprt = %p\n", __func__, r_xprt);

	rc = -EHOSTUNREACH;
658
	if (rpcrdma_ia_open(r_xprt))
659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674
		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;
	}

C
Chuck Lever 已提交
675
	rpcrdma_mrs_create(r_xprt);
676 677 678 679 680 681 682 683 684 685
	return 0;

out3:
	rpcrdma_ep_destroy(ep, ia);
out2:
	rpcrdma_ia_close(ia);
out1:
	return rc;
}

686 687 688 689 690 691 692 693 694 695 696 697
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;

	dprintk("RPC:       %s: reconnecting...\n", __func__);

	rpcrdma_ep_disconnect(ep, ia);

	rc = -EHOSTUNREACH;
698
	id = rpcrdma_create_id(r_xprt, ia);
699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730
	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:
731
	rdma_destroy_id(old);
732 733 734 735
out:
	return rc;
}

736 737 738 739 740 741
/*
 * Connect unconnected endpoint.
 */
int
rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
742 743 744
	struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
						   rx_ia);
	unsigned int extras;
745
	int rc;
746 747

retry:
748 749
	switch (ep->rep_connected) {
	case 0:
750 751 752 753 754
		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);
755 756
			rc = -ENETUNREACH;
			goto out_noupdate;
757
		}
758
		break;
759 760 761 762 763
	case -ENODEV:
		rc = rpcrdma_ep_recreate_xprt(r_xprt, ep, ia);
		if (rc)
			goto out_noupdate;
		break;
764 765 766 767
	default:
		rc = rpcrdma_ep_reconnect(r_xprt, ep, ia);
		if (rc)
			goto out;
768 769 770 771 772 773 774 775 776 777 778 779 780
	}

	ep->rep_connected = 0;

	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) {
781
		if (ep->rep_connected == -EAGAIN)
782 783
			goto retry;
		rc = ep->rep_connected;
784
		goto out;
785 786
	}

787 788 789 790 791
	dprintk("RPC:       %s: connected\n", __func__);
	extras = r_xprt->rx_buf.rb_bc_srv_max_requests;
	if (extras)
		rpcrdma_ep_post_extra_recv(r_xprt, extras);

792 793 794
out:
	if (rc)
		ep->rep_connected = rc;
795 796

out_noupdate:
797 798 799 800 801 802 803 804 805 806 807 808
	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.
 */
809
void
810 811 812 813 814 815 816 817 818 819 820 821 822 823 824
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);
		dprintk("RPC:       %s: after wait, %sconnected\n", __func__,
			(ep->rep_connected == 1) ? "still " : "dis");
	} else {
		dprintk("RPC:       %s: rdma_disconnect %i\n", __func__, rc);
		ep->rep_connected = rc;
	}
825 826

	ib_drain_qp(ia->ri_id->qp);
827 828
}

829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990
/* 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;
	}

	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.
	 */
	dprintk("RPC:       %s: empty sendctx queue\n", __func__);
	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).
 */
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);
}

991 992 993 994 995
static void
rpcrdma_mr_recovery_worker(struct work_struct *work)
{
	struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
						  rb_recovery_worker.work);
C
Chuck Lever 已提交
996
	struct rpcrdma_mr *mr;
997 998 999

	spin_lock(&buf->rb_recovery_lock);
	while (!list_empty(&buf->rb_stale_mrs)) {
C
Chuck Lever 已提交
1000
		mr = rpcrdma_mr_pop(&buf->rb_stale_mrs);
1001 1002
		spin_unlock(&buf->rb_recovery_lock);

C
Chuck Lever 已提交
1003 1004
		dprintk("RPC:       %s: recovering MR %p\n", __func__, mr);
		mr->mr_xprt->rx_ia.ri_ops->ro_recover_mr(mr);
1005 1006

		spin_lock(&buf->rb_recovery_lock);
1007
	}
1008 1009 1010 1011
	spin_unlock(&buf->rb_recovery_lock);
}

void
C
Chuck Lever 已提交
1012
rpcrdma_mr_defer_recovery(struct rpcrdma_mr *mr)
1013
{
C
Chuck Lever 已提交
1014
	struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
1015 1016 1017
	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;

	spin_lock(&buf->rb_recovery_lock);
C
Chuck Lever 已提交
1018
	rpcrdma_mr_push(mr, &buf->rb_stale_mrs);
1019 1020 1021 1022 1023
	spin_unlock(&buf->rb_recovery_lock);

	schedule_delayed_work(&buf->rb_recovery_worker, 0);
}

C
Chuck Lever 已提交
1024
static void
C
Chuck Lever 已提交
1025
rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt)
C
Chuck Lever 已提交
1026 1027 1028 1029 1030 1031 1032 1033
{
	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 < 32; count++) {
C
Chuck Lever 已提交
1034
		struct rpcrdma_mr *mr;
C
Chuck Lever 已提交
1035 1036
		int rc;

C
Chuck Lever 已提交
1037 1038
		mr = kzalloc(sizeof(*mr), GFP_KERNEL);
		if (!mr)
C
Chuck Lever 已提交
1039 1040
			break;

C
Chuck Lever 已提交
1041
		rc = ia->ri_ops->ro_init_mr(ia, mr);
C
Chuck Lever 已提交
1042
		if (rc) {
C
Chuck Lever 已提交
1043
			kfree(mr);
C
Chuck Lever 已提交
1044 1045 1046
			break;
		}

C
Chuck Lever 已提交
1047
		mr->mr_xprt = r_xprt;
C
Chuck Lever 已提交
1048

C
Chuck Lever 已提交
1049 1050
		list_add(&mr->mr_list, &free);
		list_add(&mr->mr_all, &all);
C
Chuck Lever 已提交
1051 1052
	}

C
Chuck Lever 已提交
1053 1054
	spin_lock(&buf->rb_mrlock);
	list_splice(&free, &buf->rb_mrs);
C
Chuck Lever 已提交
1055 1056
	list_splice(&all, &buf->rb_all);
	r_xprt->rx_stats.mrs_allocated += count;
C
Chuck Lever 已提交
1057
	spin_unlock(&buf->rb_mrlock);
C
Chuck Lever 已提交
1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069

	dprintk("RPC:       %s: created %u MRs\n", __func__, count);
}

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);

C
Chuck Lever 已提交
1070
	rpcrdma_mrs_create(r_xprt);
C
Chuck Lever 已提交
1071 1072
}

1073
struct rpcrdma_req *
1074 1075
rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
{
1076
	struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
1077 1078
	struct rpcrdma_req *req;

1079
	req = kzalloc(sizeof(*req), GFP_KERNEL);
1080
	if (req == NULL)
1081
		return ERR_PTR(-ENOMEM);
1082

1083 1084 1085
	spin_lock(&buffer->rb_reqslock);
	list_add(&req->rl_all, &buffer->rb_allreqs);
	spin_unlock(&buffer->rb_reqslock);
1086
	req->rl_buffer = &r_xprt->rx_buf;
1087
	INIT_LIST_HEAD(&req->rl_registered);
1088 1089 1090
	return req;
}

1091 1092 1093 1094 1095 1096 1097
/**
 * rpcrdma_create_rep - Allocate an rpcrdma_rep object
 * @r_xprt: controlling transport
 *
 * Returns 0 on success or a negative errno on failure.
 */
int
1098 1099 1100
rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
{
	struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
1101
	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1102 1103 1104 1105
	struct rpcrdma_rep *rep;
	int rc;

	rc = -ENOMEM;
1106
	rep = kzalloc(sizeof(*rep), GFP_KERNEL);
1107 1108 1109
	if (rep == NULL)
		goto out;

1110
	rep->rr_rdmabuf = rpcrdma_alloc_regbuf(cdata->inline_rsize,
1111
					       DMA_FROM_DEVICE, GFP_KERNEL);
1112 1113
	if (IS_ERR(rep->rr_rdmabuf)) {
		rc = PTR_ERR(rep->rr_rdmabuf);
1114
		goto out_free;
1115
	}
1116 1117
	xdr_buf_init(&rep->rr_hdrbuf, rep->rr_rdmabuf->rg_base,
		     rdmab_length(rep->rr_rdmabuf));
1118

1119
	rep->rr_cqe.done = rpcrdma_wc_receive;
1120
	rep->rr_rxprt = r_xprt;
1121
	INIT_WORK(&rep->rr_work, rpcrdma_deferred_completion);
1122 1123 1124 1125
	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;
1126 1127 1128 1129 1130

	spin_lock(&buf->rb_lock);
	list_add(&rep->rr_list, &buf->rb_recv_bufs);
	spin_unlock(&buf->rb_lock);
	return 0;
1131 1132 1133 1134

out_free:
	kfree(rep);
out:
1135 1136 1137
	dprintk("RPC:       %s: reply buffer %d alloc failed\n",
		__func__, rc);
	return rc;
1138 1139
}

1140
int
1141
rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
1142
{
1143
	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1144 1145
	int i, rc;

1146
	buf->rb_max_requests = r_xprt->rx_data.max_requests;
1147
	buf->rb_bc_srv_max_requests = 0;
C
Chuck Lever 已提交
1148
	spin_lock_init(&buf->rb_mrlock);
1149 1150
	spin_lock_init(&buf->rb_lock);
	spin_lock_init(&buf->rb_recovery_lock);
C
Chuck Lever 已提交
1151
	INIT_LIST_HEAD(&buf->rb_mrs);
C
Chuck Lever 已提交
1152
	INIT_LIST_HEAD(&buf->rb_all);
1153
	INIT_LIST_HEAD(&buf->rb_stale_mrs);
C
Chuck Lever 已提交
1154 1155
	INIT_DELAYED_WORK(&buf->rb_refresh_worker,
			  rpcrdma_mr_refresh_worker);
1156 1157
	INIT_DELAYED_WORK(&buf->rb_recovery_worker,
			  rpcrdma_mr_recovery_worker);
1158

C
Chuck Lever 已提交
1159
	rpcrdma_mrs_create(r_xprt);
1160

1161
	INIT_LIST_HEAD(&buf->rb_send_bufs);
1162 1163
	INIT_LIST_HEAD(&buf->rb_allreqs);
	spin_lock_init(&buf->rb_reqslock);
1164 1165 1166
	for (i = 0; i < buf->rb_max_requests; i++) {
		struct rpcrdma_req *req;

1167 1168
		req = rpcrdma_create_req(r_xprt);
		if (IS_ERR(req)) {
1169 1170
			dprintk("RPC:       %s: request buffer %d alloc"
				" failed\n", __func__, i);
1171
			rc = PTR_ERR(req);
1172 1173
			goto out;
		}
1174
		list_add(&req->rl_list, &buf->rb_send_bufs);
1175 1176 1177
	}

	INIT_LIST_HEAD(&buf->rb_recv_bufs);
1178 1179 1180
	for (i = 0; i <= buf->rb_max_requests; i++) {
		rc = rpcrdma_create_rep(r_xprt);
		if (rc)
1181 1182
			goto out;
	}
1183

1184 1185 1186 1187
	rc = rpcrdma_sendctxs_create(r_xprt);
	if (rc)
		goto out;

1188 1189 1190 1191 1192 1193
	return 0;
out:
	rpcrdma_buffer_destroy(buf);
	return rc;
}

1194 1195 1196 1197 1198 1199
static struct rpcrdma_req *
rpcrdma_buffer_get_req_locked(struct rpcrdma_buffer *buf)
{
	struct rpcrdma_req *req;

	req = list_first_entry(&buf->rb_send_bufs,
1200
			       struct rpcrdma_req, rl_list);
1201
	list_del_init(&req->rl_list);
1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215
	return req;
}

static struct rpcrdma_rep *
rpcrdma_buffer_get_rep_locked(struct rpcrdma_buffer *buf)
{
	struct rpcrdma_rep *rep;

	rep = list_first_entry(&buf->rb_recv_bufs,
			       struct rpcrdma_rep, rr_list);
	list_del(&rep->rr_list);
	return rep;
}

1216
static void
1217
rpcrdma_destroy_rep(struct rpcrdma_rep *rep)
1218
{
1219
	rpcrdma_free_regbuf(rep->rr_rdmabuf);
1220 1221 1222
	kfree(rep);
}

1223
void
1224
rpcrdma_destroy_req(struct rpcrdma_req *req)
1225
{
1226 1227 1228
	rpcrdma_free_regbuf(req->rl_recvbuf);
	rpcrdma_free_regbuf(req->rl_sendbuf);
	rpcrdma_free_regbuf(req->rl_rdmabuf);
1229 1230 1231
	kfree(req);
}

C
Chuck Lever 已提交
1232
static void
C
Chuck Lever 已提交
1233
rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf)
C
Chuck Lever 已提交
1234 1235 1236 1237
{
	struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
						   rx_buf);
	struct rpcrdma_ia *ia = rdmab_to_ia(buf);
C
Chuck Lever 已提交
1238
	struct rpcrdma_mr *mr;
C
Chuck Lever 已提交
1239 1240 1241
	unsigned int count;

	count = 0;
C
Chuck Lever 已提交
1242
	spin_lock(&buf->rb_mrlock);
C
Chuck Lever 已提交
1243
	while (!list_empty(&buf->rb_all)) {
C
Chuck Lever 已提交
1244 1245
		mr = list_entry(buf->rb_all.next, struct rpcrdma_mr, mr_all);
		list_del(&mr->mr_all);
C
Chuck Lever 已提交
1246

C
Chuck Lever 已提交
1247 1248
		spin_unlock(&buf->rb_mrlock);
		ia->ri_ops->ro_release_mr(mr);
C
Chuck Lever 已提交
1249
		count++;
C
Chuck Lever 已提交
1250
		spin_lock(&buf->rb_mrlock);
C
Chuck Lever 已提交
1251
	}
C
Chuck Lever 已提交
1252
	spin_unlock(&buf->rb_mrlock);
C
Chuck Lever 已提交
1253 1254 1255 1256 1257
	r_xprt->rx_stats.mrs_allocated = 0;

	dprintk("RPC:       %s: released %u MRs\n", __func__, count);
}

1258 1259 1260
void
rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
{
1261
	cancel_delayed_work_sync(&buf->rb_recovery_worker);
1262
	cancel_delayed_work_sync(&buf->rb_refresh_worker);
1263

1264 1265
	rpcrdma_sendctxs_destroy(buf);

1266 1267
	while (!list_empty(&buf->rb_recv_bufs)) {
		struct rpcrdma_rep *rep;
1268

1269
		rep = rpcrdma_buffer_get_rep_locked(buf);
1270
		rpcrdma_destroy_rep(rep);
1271
	}
1272
	buf->rb_send_count = 0;
1273

1274 1275
	spin_lock(&buf->rb_reqslock);
	while (!list_empty(&buf->rb_allreqs)) {
1276
		struct rpcrdma_req *req;
A
Allen Andrews 已提交
1277

1278 1279 1280 1281 1282
		req = list_first_entry(&buf->rb_allreqs,
				       struct rpcrdma_req, rl_all);
		list_del(&req->rl_all);

		spin_unlock(&buf->rb_reqslock);
1283
		rpcrdma_destroy_req(req);
1284
		spin_lock(&buf->rb_reqslock);
1285
	}
1286
	spin_unlock(&buf->rb_reqslock);
1287
	buf->rb_recv_count = 0;
A
Allen Andrews 已提交
1288

C
Chuck Lever 已提交
1289
	rpcrdma_mrs_destroy(buf);
1290 1291
}

C
Chuck Lever 已提交
1292 1293 1294 1295 1296 1297 1298 1299 1300
/**
 * 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)
1301
{
1302
	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
C
Chuck Lever 已提交
1303
	struct rpcrdma_mr *mr = NULL;
1304

C
Chuck Lever 已提交
1305 1306 1307 1308
	spin_lock(&buf->rb_mrlock);
	if (!list_empty(&buf->rb_mrs))
		mr = rpcrdma_mr_pop(&buf->rb_mrs);
	spin_unlock(&buf->rb_mrlock);
1309

C
Chuck Lever 已提交
1310 1311 1312
	if (!mr)
		goto out_nomrs;
	return mr;
C
Chuck Lever 已提交
1313

C
Chuck Lever 已提交
1314 1315
out_nomrs:
	dprintk("RPC:       %s: no MRs available\n", __func__);
1316 1317
	if (r_xprt->rx_ep.rep_connected != -ENODEV)
		schedule_delayed_work(&buf->rb_refresh_worker, 0);
C
Chuck Lever 已提交
1318 1319 1320 1321 1322

	/* Allow the reply handler and refresh worker to run */
	cond_resched();

	return NULL;
1323 1324
}

1325 1326 1327 1328 1329 1330 1331 1332
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);
}

C
Chuck Lever 已提交
1333 1334 1335 1336 1337
/**
 * rpcrdma_mr_put - Release an rpcrdma_mr object
 * @mr: object to release
 *
 */
1338
void
C
Chuck Lever 已提交
1339
rpcrdma_mr_put(struct rpcrdma_mr *mr)
1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350
{
	__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)
1351
{
C
Chuck Lever 已提交
1352
	struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
1353

1354 1355 1356
	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);
1357 1358
}

1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375
static struct rpcrdma_rep *
rpcrdma_buffer_get_rep(struct rpcrdma_buffer *buffers)
{
	/* If an RPC previously completed without a reply (say, a
	 * credential problem or a soft timeout occurs) then hold off
	 * on supplying more Receive buffers until the number of new
	 * pending RPCs catches up to the number of posted Receives.
	 */
	if (unlikely(buffers->rb_send_count < buffers->rb_recv_count))
		return NULL;

	if (unlikely(list_empty(&buffers->rb_recv_bufs)))
		return NULL;
	buffers->rb_recv_count++;
	return rpcrdma_buffer_get_rep_locked(buffers);
}

1376 1377
/*
 * Get a set of request/reply buffers.
1378 1379
 *
 * Reply buffer (if available) is attached to send buffer upon return.
1380 1381 1382 1383 1384
 */
struct rpcrdma_req *
rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
{
	struct rpcrdma_req *req;
1385

1386
	spin_lock(&buffers->rb_lock);
1387 1388
	if (list_empty(&buffers->rb_send_bufs))
		goto out_reqbuf;
1389
	buffers->rb_send_count++;
1390
	req = rpcrdma_buffer_get_req_locked(buffers);
1391
	req->rl_reply = rpcrdma_buffer_get_rep(buffers);
1392
	spin_unlock(&buffers->rb_lock);
1393
	return req;
1394

1395
out_reqbuf:
1396
	spin_unlock(&buffers->rb_lock);
1397
	pr_warn("RPC:       %s: out of request buffers\n", __func__);
1398
	return NULL;
1399 1400 1401 1402 1403 1404 1405 1406 1407 1408
}

/*
 * Put request/reply buffers back into pool.
 * Pre-decrement counter/array index.
 */
void
rpcrdma_buffer_put(struct rpcrdma_req *req)
{
	struct rpcrdma_buffer *buffers = req->rl_buffer;
1409
	struct rpcrdma_rep *rep = req->rl_reply;
1410

1411 1412
	req->rl_reply = NULL;

1413
	spin_lock(&buffers->rb_lock);
1414
	buffers->rb_send_count--;
1415
	list_add_tail(&req->rl_list, &buffers->rb_send_bufs);
1416 1417
	if (rep) {
		buffers->rb_recv_count--;
1418
		list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
1419
	}
1420
	spin_unlock(&buffers->rb_lock);
1421 1422 1423 1424
}

/*
 * Recover reply buffers from pool.
1425
 * This happens when recovering from disconnect.
1426 1427 1428 1429 1430 1431
 */
void
rpcrdma_recv_buffer_get(struct rpcrdma_req *req)
{
	struct rpcrdma_buffer *buffers = req->rl_buffer;

1432
	spin_lock(&buffers->rb_lock);
1433
	req->rl_reply = rpcrdma_buffer_get_rep(buffers);
1434
	spin_unlock(&buffers->rb_lock);
1435 1436 1437 1438
}

/*
 * Put reply buffers back into pool when not attached to
1439
 * request. This happens in error conditions.
1440 1441 1442 1443
 */
void
rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
{
1444
	struct rpcrdma_buffer *buffers = &rep->rr_rxprt->rx_buf;
1445

1446
	spin_lock(&buffers->rb_lock);
1447
	buffers->rb_recv_count--;
1448
	list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
1449
	spin_unlock(&buffers->rb_lock);
1450 1451
}

1452
/**
1453
 * rpcrdma_alloc_regbuf - allocate and DMA-map memory for SEND/RECV buffers
1454
 * @size: size of buffer to be allocated, in bytes
1455
 * @direction: direction of data movement
1456 1457
 * @flags: GFP flags
 *
1458 1459
 * Returns an ERR_PTR, or a pointer to a regbuf, a buffer that
 * can be persistently DMA-mapped for I/O.
1460 1461
 *
 * xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
1462 1463
 * receiving the payload of RDMA RECV operations. During Long Calls
 * or Replies they may be registered externally via ro_map.
1464 1465
 */
struct rpcrdma_regbuf *
1466 1467
rpcrdma_alloc_regbuf(size_t size, enum dma_data_direction direction,
		     gfp_t flags)
1468 1469 1470 1471 1472
{
	struct rpcrdma_regbuf *rb;

	rb = kmalloc(sizeof(*rb) + size, flags);
	if (rb == NULL)
1473
		return ERR_PTR(-ENOMEM);
1474

1475
	rb->rg_device = NULL;
1476
	rb->rg_direction = direction;
1477
	rb->rg_iov.length = size;
1478 1479

	return rb;
1480
}
1481

1482 1483 1484 1485 1486 1487 1488 1489
/**
 * __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)
{
1490 1491
	struct ib_device *device = ia->ri_device;

1492 1493 1494
	if (rb->rg_direction == DMA_NONE)
		return false;

1495
	rb->rg_iov.addr = ib_dma_map_single(device,
1496 1497 1498
					    (void *)rb->rg_base,
					    rdmab_length(rb),
					    rb->rg_direction);
1499
	if (ib_dma_mapping_error(device, rdmab_addr(rb)))
1500 1501
		return false;

1502
	rb->rg_device = device;
1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515
	rb->rg_iov.lkey = ia->ri_pd->local_dma_lkey;
	return true;
}

static void
rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb)
{
	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;
1516 1517 1518 1519 1520 1521 1522
}

/**
 * rpcrdma_free_regbuf - deregister and free registered buffer
 * @rb: regbuf to be deregistered and freed
 */
void
1523
rpcrdma_free_regbuf(struct rpcrdma_regbuf *rb)
1524
{
1525 1526 1527
	if (!rb)
		return;

1528
	rpcrdma_dma_unmap_regbuf(rb);
1529
	kfree(rb);
1530 1531
}

1532 1533 1534 1535 1536 1537 1538 1539 1540 1541
/*
 * 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)
{
1542
	struct ib_send_wr *send_wr = &req->rl_sendctx->sc_wr;
1543
	struct ib_send_wr *send_wr_fail;
1544
	int rc;
1545

1546 1547
	if (req->rl_reply) {
		rc = rpcrdma_ep_post_recv(ia, req->rl_reply);
1548
		if (rc)
1549
			return rc;
1550 1551 1552
		req->rl_reply = NULL;
	}

1553 1554
	if (!ep->rep_send_count ||
	    test_bit(RPCRDMA_REQ_F_TX_RESOURCES, &req->rl_flags)) {
1555 1556 1557 1558 1559 1560
		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;
	}
1561

1562
	rc = ib_post_send(ia->ri_id->qp, send_wr, &send_wr_fail);
1563
	trace_xprtrdma_post_send(req, rc);
1564
	if (rc)
1565
		return -ENOTCONN;
1566
	return 0;
1567 1568 1569 1570 1571 1572
}

int
rpcrdma_ep_post_recv(struct rpcrdma_ia *ia,
		     struct rpcrdma_rep *rep)
{
1573
	struct ib_recv_wr *recv_wr_fail;
1574 1575
	int rc;

1576 1577
	if (!rpcrdma_dma_map_regbuf(ia, rep->rr_rdmabuf))
		goto out_map;
1578
	rc = ib_post_recv(ia->ri_id->qp, &rep->rr_recv_wr, &recv_wr_fail);
1579
	if (rc)
1580 1581 1582
		goto out_postrecv;
	return 0;

1583 1584 1585 1586
out_map:
	pr_err("rpcrdma: failed to DMA map the Receive buffer\n");
	return -EIO;

1587 1588 1589
out_postrecv:
	pr_err("rpcrdma: ib_post_recv returned %i\n", rc);
	return -ENOTCONN;
1590
}
1591

1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607
/**
 * rpcrdma_ep_post_extra_recv - Post buffers for incoming backchannel requests
 * @r_xprt: transport associated with these backchannel resources
 * @min_reqs: minimum number of incoming requests expected
 *
 * Returns zero if all requested buffers were posted, or a negative errno.
 */
int
rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *r_xprt, unsigned int count)
{
	struct rpcrdma_buffer *buffers = &r_xprt->rx_buf;
	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
	struct rpcrdma_rep *rep;
	int rc;

	while (count--) {
1608
		spin_lock(&buffers->rb_lock);
1609 1610 1611
		if (list_empty(&buffers->rb_recv_bufs))
			goto out_reqbuf;
		rep = rpcrdma_buffer_get_rep_locked(buffers);
1612
		spin_unlock(&buffers->rb_lock);
1613

1614
		rc = rpcrdma_ep_post_recv(ia, rep);
1615 1616 1617 1618 1619 1620 1621
		if (rc)
			goto out_rc;
	}

	return 0;

out_reqbuf:
1622
	spin_unlock(&buffers->rb_lock);
1623 1624 1625 1626 1627 1628 1629
	pr_warn("%s: no extra receive buffers\n", __func__);
	return -ENOMEM;

out_rc:
	rpcrdma_recv_buffer_put(rep);
	return rc;
}