1/*
2 * linux/fs/9p/trans_rdma.c
3 *
4 * RDMA transport layer based on the trans_fd.c implementation.
5 *
6 *  Copyright (C) 2008 by Tom Tucker <tom@opengridcomputing.com>
7 *  Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
8 *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
9 *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
10 *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
11 *
12 *  This program is free software; you can redistribute it and/or modify
13 *  it under the terms of the GNU General Public License version 2
14 *  as published by the Free Software Foundation.
15 *
16 *  This program is distributed in the hope that it will be useful,
17 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
18 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 *  GNU General Public License for more details.
20 *
21 *  You should have received a copy of the GNU General Public License
22 *  along with this program; if not, write to:
23 *  Free Software Foundation
24 *  51 Franklin Street, Fifth Floor
25 *  Boston, MA  02111-1301  USA
26 *
27 */
28
29#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
30
31#include <linux/in.h>
32#include <linux/module.h>
33#include <linux/net.h>
34#include <linux/ipv6.h>
35#include <linux/kthread.h>
36#include <linux/errno.h>
37#include <linux/kernel.h>
38#include <linux/un.h>
39#include <linux/uaccess.h>
40#include <linux/inet.h>
41#include <linux/idr.h>
42#include <linux/file.h>
43#include <linux/parser.h>
44#include <linux/semaphore.h>
45#include <linux/slab.h>
46#include <net/9p/9p.h>
47#include <net/9p/client.h>
48#include <net/9p/transport.h>
49#include <rdma/ib_verbs.h>
50#include <rdma/rdma_cm.h>
51
52#define P9_PORT			5640
53#define P9_RDMA_SQ_DEPTH	32
54#define P9_RDMA_RQ_DEPTH	32
55#define P9_RDMA_SEND_SGE	4
56#define P9_RDMA_RECV_SGE	4
57#define P9_RDMA_IRD		0
58#define P9_RDMA_ORD		0
59#define P9_RDMA_TIMEOUT		30000		/* 30 seconds */
60#define P9_RDMA_MAXSIZE		(4*4096)	/* Min SGE is 4, so we can
61						 * safely advertise a maxsize
62						 * of 64k */
63
64/**
65 * struct p9_trans_rdma - RDMA transport instance
66 *
67 * @state: tracks the transport state machine for connection setup and tear down
68 * @cm_id: The RDMA CM ID
69 * @pd: Protection Domain pointer
70 * @qp: Queue Pair pointer
71 * @cq: Completion Queue pointer
72 * @dm_mr: DMA Memory Region pointer
73 * @lkey: The local access only memory region key
74 * @timeout: Number of uSecs to wait for connection management events
75 * @sq_depth: The depth of the Send Queue
76 * @sq_sem: Semaphore for the SQ
77 * @rq_depth: The depth of the Receive Queue.
78 * @rq_count: Count of requests in the Receive Queue.
79 * @addr: The remote peer's address
80 * @req_lock: Protects the active request list
81 * @cm_done: Completion event for connection management tracking
82 */
83struct p9_trans_rdma {
84	enum {
85		P9_RDMA_INIT,
86		P9_RDMA_ADDR_RESOLVED,
87		P9_RDMA_ROUTE_RESOLVED,
88		P9_RDMA_CONNECTED,
89		P9_RDMA_FLUSHING,
90		P9_RDMA_CLOSING,
91		P9_RDMA_CLOSED,
92	} state;
93	struct rdma_cm_id *cm_id;
94	struct ib_pd *pd;
95	struct ib_qp *qp;
96	struct ib_cq *cq;
97	struct ib_mr *dma_mr;
98	u32 lkey;
99	long timeout;
100	int sq_depth;
101	struct semaphore sq_sem;
102	int rq_depth;
103	atomic_t rq_count;
104	struct sockaddr_in addr;
105	spinlock_t req_lock;
106
107	struct completion cm_done;
108};
109
110/**
111 * p9_rdma_context - Keeps track of in-process WR
112 *
113 * @wc_op: The original WR op for when the CQE completes in error.
114 * @busa: Bus address to unmap when the WR completes
115 * @req: Keeps track of requests (send)
116 * @rc: Keepts track of replies (receive)
117 */
118struct p9_rdma_req;
119struct p9_rdma_context {
120	enum ib_wc_opcode wc_op;
121	dma_addr_t busa;
122	union {
123		struct p9_req_t *req;
124		struct p9_fcall *rc;
125	};
126};
127
128/**
129 * p9_rdma_opts - Collection of mount options
130 * @port: port of connection
131 * @sq_depth: The requested depth of the SQ. This really doesn't need
132 * to be any deeper than the number of threads used in the client
133 * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
134 * @timeout: Time to wait in msecs for CM events
135 */
136struct p9_rdma_opts {
137	short port;
138	int sq_depth;
139	int rq_depth;
140	long timeout;
141};
142
143/*
144 * Option Parsing (code inspired by NFS code)
145 */
146enum {
147	/* Options that take integer arguments */
148	Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout, Opt_err,
149};
150
151static match_table_t tokens = {
152	{Opt_port, "port=%u"},
153	{Opt_sq_depth, "sq=%u"},
154	{Opt_rq_depth, "rq=%u"},
155	{Opt_timeout, "timeout=%u"},
156	{Opt_err, NULL},
157};
158
159/**
160 * parse_opts - parse mount options into rdma options structure
161 * @params: options string passed from mount
162 * @opts: rdma transport-specific structure to parse options into
163 *
164 * Returns 0 upon success, -ERRNO upon failure
165 */
166static int parse_opts(char *params, struct p9_rdma_opts *opts)
167{
168	char *p;
169	substring_t args[MAX_OPT_ARGS];
170	int option;
171	char *options, *tmp_options;
172
173	opts->port = P9_PORT;
174	opts->sq_depth = P9_RDMA_SQ_DEPTH;
175	opts->rq_depth = P9_RDMA_RQ_DEPTH;
176	opts->timeout = P9_RDMA_TIMEOUT;
177
178	if (!params)
179		return 0;
180
181	tmp_options = kstrdup(params, GFP_KERNEL);
182	if (!tmp_options) {
183		p9_debug(P9_DEBUG_ERROR,
184			 "failed to allocate copy of option string\n");
185		return -ENOMEM;
186	}
187	options = tmp_options;
188
189	while ((p = strsep(&options, ",")) != NULL) {
190		int token;
191		int r;
192		if (!*p)
193			continue;
194		token = match_token(p, tokens, args);
195		r = match_int(&args[0], &option);
196		if (r < 0) {
197			p9_debug(P9_DEBUG_ERROR,
198				 "integer field, but no integer?\n");
199			continue;
200		}
201		switch (token) {
202		case Opt_port:
203			opts->port = option;
204			break;
205		case Opt_sq_depth:
206			opts->sq_depth = option;
207			break;
208		case Opt_rq_depth:
209			opts->rq_depth = option;
210			break;
211		case Opt_timeout:
212			opts->timeout = option;
213			break;
214		default:
215			continue;
216		}
217	}
218	/* RQ must be at least as large as the SQ */
219	opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
220	kfree(tmp_options);
221	return 0;
222}
223
224static int
225p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
226{
227	struct p9_client *c = id->context;
228	struct p9_trans_rdma *rdma = c->trans;
229	switch (event->event) {
230	case RDMA_CM_EVENT_ADDR_RESOLVED:
231		BUG_ON(rdma->state != P9_RDMA_INIT);
232		rdma->state = P9_RDMA_ADDR_RESOLVED;
233		break;
234
235	case RDMA_CM_EVENT_ROUTE_RESOLVED:
236		BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
237		rdma->state = P9_RDMA_ROUTE_RESOLVED;
238		break;
239
240	case RDMA_CM_EVENT_ESTABLISHED:
241		BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
242		rdma->state = P9_RDMA_CONNECTED;
243		break;
244
245	case RDMA_CM_EVENT_DISCONNECTED:
246		if (rdma)
247			rdma->state = P9_RDMA_CLOSED;
248		if (c)
249			c->status = Disconnected;
250		break;
251
252	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
253		break;
254
255	case RDMA_CM_EVENT_ADDR_CHANGE:
256	case RDMA_CM_EVENT_ROUTE_ERROR:
257	case RDMA_CM_EVENT_DEVICE_REMOVAL:
258	case RDMA_CM_EVENT_MULTICAST_JOIN:
259	case RDMA_CM_EVENT_MULTICAST_ERROR:
260	case RDMA_CM_EVENT_REJECTED:
261	case RDMA_CM_EVENT_CONNECT_REQUEST:
262	case RDMA_CM_EVENT_CONNECT_RESPONSE:
263	case RDMA_CM_EVENT_CONNECT_ERROR:
264	case RDMA_CM_EVENT_ADDR_ERROR:
265	case RDMA_CM_EVENT_UNREACHABLE:
266		c->status = Disconnected;
267		rdma_disconnect(rdma->cm_id);
268		break;
269	default:
270		BUG();
271	}
272	complete(&rdma->cm_done);
273	return 0;
274}
275
276static void
277handle_recv(struct p9_client *client, struct p9_trans_rdma *rdma,
278	    struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
279{
280	struct p9_req_t *req;
281	int err = 0;
282	int16_t tag;
283
284	req = NULL;
285	ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
286							 DMA_FROM_DEVICE);
287
288	if (status != IB_WC_SUCCESS)
289		goto err_out;
290
291	err = p9_parse_header(c->rc, NULL, NULL, &tag, 1);
292	if (err)
293		goto err_out;
294
295	req = p9_tag_lookup(client, tag);
296	if (!req)
297		goto err_out;
298
299	req->rc = c->rc;
300	req->status = REQ_STATUS_RCVD;
301	p9_client_cb(client, req);
302
303	return;
304
305 err_out:
306	p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n", req, err, status);
307	rdma->state = P9_RDMA_FLUSHING;
308	client->status = Disconnected;
309}
310
311static void
312handle_send(struct p9_client *client, struct p9_trans_rdma *rdma,
313	    struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
314{
315	ib_dma_unmap_single(rdma->cm_id->device,
316			    c->busa, c->req->tc->size,
317			    DMA_TO_DEVICE);
318}
319
320static void qp_event_handler(struct ib_event *event, void *context)
321{
322	p9_debug(P9_DEBUG_ERROR, "QP event %d context %p\n",
323		 event->event, context);
324}
325
326static void cq_comp_handler(struct ib_cq *cq, void *cq_context)
327{
328	struct p9_client *client = cq_context;
329	struct p9_trans_rdma *rdma = client->trans;
330	int ret;
331	struct ib_wc wc;
332
333	ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
334	while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) {
335		struct p9_rdma_context *c = (void *) (unsigned long) wc.wr_id;
336
337		switch (c->wc_op) {
338		case IB_WC_RECV:
339			atomic_dec(&rdma->rq_count);
340			handle_recv(client, rdma, c, wc.status, wc.byte_len);
341			break;
342
343		case IB_WC_SEND:
344			handle_send(client, rdma, c, wc.status, wc.byte_len);
345			up(&rdma->sq_sem);
346			break;
347
348		default:
349			pr_err("unexpected completion type, c->wc_op=%d, wc.opcode=%d, status=%d\n",
350			       c->wc_op, wc.opcode, wc.status);
351			break;
352		}
353		kfree(c);
354	}
355}
356
357static void cq_event_handler(struct ib_event *e, void *v)
358{
359	p9_debug(P9_DEBUG_ERROR, "CQ event %d context %p\n", e->event, v);
360}
361
362static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
363{
364	if (!rdma)
365		return;
366
367	if (rdma->dma_mr && !IS_ERR(rdma->dma_mr))
368		ib_dereg_mr(rdma->dma_mr);
369
370	if (rdma->qp && !IS_ERR(rdma->qp))
371		ib_destroy_qp(rdma->qp);
372
373	if (rdma->pd && !IS_ERR(rdma->pd))
374		ib_dealloc_pd(rdma->pd);
375
376	if (rdma->cq && !IS_ERR(rdma->cq))
377		ib_destroy_cq(rdma->cq);
378
379	if (rdma->cm_id && !IS_ERR(rdma->cm_id))
380		rdma_destroy_id(rdma->cm_id);
381
382	kfree(rdma);
383}
384
385static int
386post_recv(struct p9_client *client, struct p9_rdma_context *c)
387{
388	struct p9_trans_rdma *rdma = client->trans;
389	struct ib_recv_wr wr, *bad_wr;
390	struct ib_sge sge;
391
392	c->busa = ib_dma_map_single(rdma->cm_id->device,
393				    c->rc->sdata, client->msize,
394				    DMA_FROM_DEVICE);
395	if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
396		goto error;
397
398	sge.addr = c->busa;
399	sge.length = client->msize;
400	sge.lkey = rdma->lkey;
401
402	wr.next = NULL;
403	c->wc_op = IB_WC_RECV;
404	wr.wr_id = (unsigned long) c;
405	wr.sg_list = &sge;
406	wr.num_sge = 1;
407	return ib_post_recv(rdma->qp, &wr, &bad_wr);
408
409 error:
410	p9_debug(P9_DEBUG_ERROR, "EIO\n");
411	return -EIO;
412}
413
414static int rdma_request(struct p9_client *client, struct p9_req_t *req)
415{
416	struct p9_trans_rdma *rdma = client->trans;
417	struct ib_send_wr wr, *bad_wr;
418	struct ib_sge sge;
419	int err = 0;
420	unsigned long flags;
421	struct p9_rdma_context *c = NULL;
422	struct p9_rdma_context *rpl_context = NULL;
423
424	/* Allocate an fcall for the reply */
425	rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS);
426	if (!rpl_context) {
427		err = -ENOMEM;
428		goto err_close;
429	}
430
431	/*
432	 * If the request has a buffer, steal it, otherwise
433	 * allocate a new one.  Typically, requests should already
434	 * have receive buffers allocated and just swap them around
435	 */
436	if (!req->rc) {
437		req->rc = kmalloc(sizeof(struct p9_fcall)+client->msize,
438				  GFP_NOFS);
439		if (req->rc) {
440			req->rc->sdata = (char *) req->rc +
441						sizeof(struct p9_fcall);
442			req->rc->capacity = client->msize;
443		}
444	}
445	rpl_context->rc = req->rc;
446	if (!rpl_context->rc) {
447		err = -ENOMEM;
448		goto err_free2;
449	}
450
451	/*
452	 * Post a receive buffer for this request. We need to ensure
453	 * there is a reply buffer available for every outstanding
454	 * request. A flushed request can result in no reply for an
455	 * outstanding request, so we must keep a count to avoid
456	 * overflowing the RQ.
457	 */
458	if (atomic_inc_return(&rdma->rq_count) <= rdma->rq_depth) {
459		err = post_recv(client, rpl_context);
460		if (err)
461			goto err_free1;
462	} else
463		atomic_dec(&rdma->rq_count);
464
465	/* remove posted receive buffer from request structure */
466	req->rc = NULL;
467
468	/* Post the request */
469	c = kmalloc(sizeof *c, GFP_NOFS);
470	if (!c) {
471		err = -ENOMEM;
472		goto err_free1;
473	}
474	c->req = req;
475
476	c->busa = ib_dma_map_single(rdma->cm_id->device,
477				    c->req->tc->sdata, c->req->tc->size,
478				    DMA_TO_DEVICE);
479	if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
480		goto error;
481
482	sge.addr = c->busa;
483	sge.length = c->req->tc->size;
484	sge.lkey = rdma->lkey;
485
486	wr.next = NULL;
487	c->wc_op = IB_WC_SEND;
488	wr.wr_id = (unsigned long) c;
489	wr.opcode = IB_WR_SEND;
490	wr.send_flags = IB_SEND_SIGNALED;
491	wr.sg_list = &sge;
492	wr.num_sge = 1;
493
494	if (down_interruptible(&rdma->sq_sem))
495		goto error;
496
497	return ib_post_send(rdma->qp, &wr, &bad_wr);
498
499 error:
500	kfree(c);
501	kfree(rpl_context->rc);
502	kfree(rpl_context);
503	p9_debug(P9_DEBUG_ERROR, "EIO\n");
504	return -EIO;
505 err_free1:
506	kfree(rpl_context->rc);
507 err_free2:
508	kfree(rpl_context);
509 err_close:
510	spin_lock_irqsave(&rdma->req_lock, flags);
511	if (rdma->state < P9_RDMA_CLOSING) {
512		rdma->state = P9_RDMA_CLOSING;
513		spin_unlock_irqrestore(&rdma->req_lock, flags);
514		rdma_disconnect(rdma->cm_id);
515	} else
516		spin_unlock_irqrestore(&rdma->req_lock, flags);
517	return err;
518}
519
520static void rdma_close(struct p9_client *client)
521{
522	struct p9_trans_rdma *rdma;
523
524	if (!client)
525		return;
526
527	rdma = client->trans;
528	if (!rdma)
529		return;
530
531	client->status = Disconnected;
532	rdma_disconnect(rdma->cm_id);
533	rdma_destroy_trans(rdma);
534}
535
536/**
537 * alloc_rdma - Allocate and initialize the rdma transport structure
538 * @opts: Mount options structure
539 */
540static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
541{
542	struct p9_trans_rdma *rdma;
543
544	rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
545	if (!rdma)
546		return NULL;
547
548	rdma->sq_depth = opts->sq_depth;
549	rdma->rq_depth = opts->rq_depth;
550	rdma->timeout = opts->timeout;
551	spin_lock_init(&rdma->req_lock);
552	init_completion(&rdma->cm_done);
553	sema_init(&rdma->sq_sem, rdma->sq_depth);
554	atomic_set(&rdma->rq_count, 0);
555
556	return rdma;
557}
558
559/* its not clear to me we can do anything after send has been posted */
560static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
561{
562	return 1;
563}
564
565/**
566 * trans_create_rdma - Transport method for creating atransport instance
567 * @client: client instance
568 * @addr: IP address string
569 * @args: Mount options string
570 */
571static int
572rdma_create_trans(struct p9_client *client, const char *addr, char *args)
573{
574	int err;
575	struct p9_rdma_opts opts;
576	struct p9_trans_rdma *rdma;
577	struct rdma_conn_param conn_param;
578	struct ib_qp_init_attr qp_attr;
579	struct ib_device_attr devattr;
580
581	/* Parse the transport specific mount options */
582	err = parse_opts(args, &opts);
583	if (err < 0)
584		return err;
585
586	/* Create and initialize the RDMA transport structure */
587	rdma = alloc_rdma(&opts);
588	if (!rdma)
589		return -ENOMEM;
590
591	/* Create the RDMA CM ID */
592	rdma->cm_id = rdma_create_id(p9_cm_event_handler, client, RDMA_PS_TCP,
593				     IB_QPT_RC);
594	if (IS_ERR(rdma->cm_id))
595		goto error;
596
597	/* Associate the client with the transport */
598	client->trans = rdma;
599
600	/* Resolve the server's address */
601	rdma->addr.sin_family = AF_INET;
602	rdma->addr.sin_addr.s_addr = in_aton(addr);
603	rdma->addr.sin_port = htons(opts.port);
604	err = rdma_resolve_addr(rdma->cm_id, NULL,
605				(struct sockaddr *)&rdma->addr,
606				rdma->timeout);
607	if (err)
608		goto error;
609	err = wait_for_completion_interruptible(&rdma->cm_done);
610	if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
611		goto error;
612
613	/* Resolve the route to the server */
614	err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
615	if (err)
616		goto error;
617	err = wait_for_completion_interruptible(&rdma->cm_done);
618	if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
619		goto error;
620
621	/* Query the device attributes */
622	err = ib_query_device(rdma->cm_id->device, &devattr);
623	if (err)
624		goto error;
625
626	/* Create the Completion Queue */
627	rdma->cq = ib_create_cq(rdma->cm_id->device, cq_comp_handler,
628				cq_event_handler, client,
629				opts.sq_depth + opts.rq_depth + 1, 0);
630	if (IS_ERR(rdma->cq))
631		goto error;
632	ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
633
634	/* Create the Protection Domain */
635	rdma->pd = ib_alloc_pd(rdma->cm_id->device);
636	if (IS_ERR(rdma->pd))
637		goto error;
638
639	/* Cache the DMA lkey in the transport */
640	rdma->dma_mr = NULL;
641	if (devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)
642		rdma->lkey = rdma->cm_id->device->local_dma_lkey;
643	else {
644		rdma->dma_mr = ib_get_dma_mr(rdma->pd, IB_ACCESS_LOCAL_WRITE);
645		if (IS_ERR(rdma->dma_mr))
646			goto error;
647		rdma->lkey = rdma->dma_mr->lkey;
648	}
649
650	/* Create the Queue Pair */
651	memset(&qp_attr, 0, sizeof qp_attr);
652	qp_attr.event_handler = qp_event_handler;
653	qp_attr.qp_context = client;
654	qp_attr.cap.max_send_wr = opts.sq_depth;
655	qp_attr.cap.max_recv_wr = opts.rq_depth;
656	qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
657	qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
658	qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
659	qp_attr.qp_type = IB_QPT_RC;
660	qp_attr.send_cq = rdma->cq;
661	qp_attr.recv_cq = rdma->cq;
662	err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
663	if (err)
664		goto error;
665	rdma->qp = rdma->cm_id->qp;
666
667	/* Request a connection */
668	memset(&conn_param, 0, sizeof(conn_param));
669	conn_param.private_data = NULL;
670	conn_param.private_data_len = 0;
671	conn_param.responder_resources = P9_RDMA_IRD;
672	conn_param.initiator_depth = P9_RDMA_ORD;
673	err = rdma_connect(rdma->cm_id, &conn_param);
674	if (err)
675		goto error;
676	err = wait_for_completion_interruptible(&rdma->cm_done);
677	if (err || (rdma->state != P9_RDMA_CONNECTED))
678		goto error;
679
680	client->status = Connected;
681
682	return 0;
683
684error:
685	rdma_destroy_trans(rdma);
686	return -ENOTCONN;
687}
688
689static struct p9_trans_module p9_rdma_trans = {
690	.name = "rdma",
691	.maxsize = P9_RDMA_MAXSIZE,
692	.def = 0,
693	.owner = THIS_MODULE,
694	.create = rdma_create_trans,
695	.close = rdma_close,
696	.request = rdma_request,
697	.cancel = rdma_cancel,
698};
699
700/**
701 * p9_trans_rdma_init - Register the 9P RDMA transport driver
702 */
703static int __init p9_trans_rdma_init(void)
704{
705	v9fs_register_trans(&p9_rdma_trans);
706	return 0;
707}
708
709static void __exit p9_trans_rdma_exit(void)
710{
711	v9fs_unregister_trans(&p9_rdma_trans);
712}
713
714module_init(p9_trans_rdma_init);
715module_exit(p9_trans_rdma_exit);
716
717MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
718MODULE_DESCRIPTION("RDMA Transport for 9P");
719MODULE_LICENSE("Dual BSD/GPL");
720