blob: 928f2bb9bf8d5d4d43d6324c3ea989a9daf12728 [file] [log] [blame]
Tom Tuckerfc79d4b2008-10-22 18:47:39 -05001/*
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
Joe Perches5d385152011-11-28 10:40:46 -080029#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
30
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050031#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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090045#include <linux/slab.h>
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050046#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>
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050051
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 */
Simon Derr3fcc62f2013-06-21 15:32:37 +020060#define P9_RDMA_MAXSIZE (1024*1024) /* 1MB */
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050061
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050062/**
63 * struct p9_trans_rdma - RDMA transport instance
64 *
65 * @state: tracks the transport state machine for connection setup and tear down
66 * @cm_id: The RDMA CM ID
67 * @pd: Protection Domain pointer
68 * @qp: Queue Pair pointer
69 * @cq: Completion Queue pointer
Abhishek Kulkarni0e155972009-07-19 13:41:55 -060070 * @dm_mr: DMA Memory Region pointer
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050071 * @lkey: The local access only memory region key
72 * @timeout: Number of uSecs to wait for connection management events
73 * @sq_depth: The depth of the Send Queue
74 * @sq_sem: Semaphore for the SQ
75 * @rq_depth: The depth of the Receive Queue.
Simon Derrfd453d02013-06-21 15:32:39 +020076 * @rq_sem: Semaphore for the RQ
Simon Derr1cff3302013-06-21 15:32:42 +020077 * @excess_rc : Amount of posted Receive Contexts without a pending request.
78 * See rdma_request()
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050079 * @addr: The remote peer's address
80 * @req_lock: Protects the active request list
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050081 * @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;
Simon Derrfd453d02013-06-21 15:32:39 +0200103 struct semaphore rq_sem;
Simon Derr1cff3302013-06-21 15:32:42 +0200104 atomic_t excess_rc;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500105 struct sockaddr_in addr;
106 spinlock_t req_lock;
107
108 struct completion cm_done;
109};
110
111/**
112 * p9_rdma_context - Keeps track of in-process WR
113 *
114 * @wc_op: The original WR op for when the CQE completes in error.
115 * @busa: Bus address to unmap when the WR completes
116 * @req: Keeps track of requests (send)
117 * @rc: Keepts track of replies (receive)
118 */
119struct p9_rdma_req;
120struct p9_rdma_context {
121 enum ib_wc_opcode wc_op;
122 dma_addr_t busa;
123 union {
124 struct p9_req_t *req;
125 struct p9_fcall *rc;
126 };
127};
128
129/**
130 * p9_rdma_opts - Collection of mount options
131 * @port: port of connection
132 * @sq_depth: The requested depth of the SQ. This really doesn't need
133 * to be any deeper than the number of threads used in the client
134 * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
135 * @timeout: Time to wait in msecs for CM events
136 */
137struct p9_rdma_opts {
138 short port;
139 int sq_depth;
140 int rq_depth;
141 long timeout;
142};
143
144/*
145 * Option Parsing (code inspired by NFS code)
146 */
147enum {
148 /* Options that take integer arguments */
149 Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout, Opt_err,
150};
151
152static match_table_t tokens = {
153 {Opt_port, "port=%u"},
154 {Opt_sq_depth, "sq=%u"},
155 {Opt_rq_depth, "rq=%u"},
156 {Opt_timeout, "timeout=%u"},
157 {Opt_err, NULL},
158};
159
160/**
Abhishek Kulkarni0e155972009-07-19 13:41:55 -0600161 * parse_opts - parse mount options into rdma options structure
162 * @params: options string passed from mount
163 * @opts: rdma transport-specific structure to parse options into
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500164 *
165 * Returns 0 upon success, -ERRNO upon failure
166 */
167static int parse_opts(char *params, struct p9_rdma_opts *opts)
168{
169 char *p;
170 substring_t args[MAX_OPT_ARGS];
171 int option;
Eric Van Hensbergend8c8a9e2010-02-08 16:23:23 -0600172 char *options, *tmp_options;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500173
174 opts->port = P9_PORT;
175 opts->sq_depth = P9_RDMA_SQ_DEPTH;
176 opts->rq_depth = P9_RDMA_RQ_DEPTH;
177 opts->timeout = P9_RDMA_TIMEOUT;
178
179 if (!params)
180 return 0;
181
Eric Van Hensbergend8c8a9e2010-02-08 16:23:23 -0600182 tmp_options = kstrdup(params, GFP_KERNEL);
183 if (!tmp_options) {
Joe Perches5d385152011-11-28 10:40:46 -0800184 p9_debug(P9_DEBUG_ERROR,
185 "failed to allocate copy of option string\n");
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500186 return -ENOMEM;
187 }
Eric Van Hensbergend8c8a9e2010-02-08 16:23:23 -0600188 options = tmp_options;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500189
190 while ((p = strsep(&options, ",")) != NULL) {
191 int token;
192 int r;
193 if (!*p)
194 continue;
195 token = match_token(p, tokens, args);
196 r = match_int(&args[0], &option);
197 if (r < 0) {
Joe Perches5d385152011-11-28 10:40:46 -0800198 p9_debug(P9_DEBUG_ERROR,
199 "integer field, but no integer?\n");
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500200 continue;
201 }
202 switch (token) {
203 case Opt_port:
204 opts->port = option;
205 break;
206 case Opt_sq_depth:
207 opts->sq_depth = option;
208 break;
209 case Opt_rq_depth:
210 opts->rq_depth = option;
211 break;
212 case Opt_timeout:
213 opts->timeout = option;
214 break;
215 default:
216 continue;
217 }
218 }
219 /* RQ must be at least as large as the SQ */
220 opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
Eric Van Hensbergend8c8a9e2010-02-08 16:23:23 -0600221 kfree(tmp_options);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500222 return 0;
223}
224
225static int
226p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
227{
228 struct p9_client *c = id->context;
229 struct p9_trans_rdma *rdma = c->trans;
230 switch (event->event) {
231 case RDMA_CM_EVENT_ADDR_RESOLVED:
232 BUG_ON(rdma->state != P9_RDMA_INIT);
233 rdma->state = P9_RDMA_ADDR_RESOLVED;
234 break;
235
236 case RDMA_CM_EVENT_ROUTE_RESOLVED:
237 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
238 rdma->state = P9_RDMA_ROUTE_RESOLVED;
239 break;
240
241 case RDMA_CM_EVENT_ESTABLISHED:
242 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
243 rdma->state = P9_RDMA_CONNECTED;
244 break;
245
246 case RDMA_CM_EVENT_DISCONNECTED:
247 if (rdma)
248 rdma->state = P9_RDMA_CLOSED;
249 if (c)
250 c->status = Disconnected;
251 break;
252
253 case RDMA_CM_EVENT_TIMEWAIT_EXIT:
254 break;
255
256 case RDMA_CM_EVENT_ADDR_CHANGE:
257 case RDMA_CM_EVENT_ROUTE_ERROR:
258 case RDMA_CM_EVENT_DEVICE_REMOVAL:
259 case RDMA_CM_EVENT_MULTICAST_JOIN:
260 case RDMA_CM_EVENT_MULTICAST_ERROR:
261 case RDMA_CM_EVENT_REJECTED:
262 case RDMA_CM_EVENT_CONNECT_REQUEST:
263 case RDMA_CM_EVENT_CONNECT_RESPONSE:
264 case RDMA_CM_EVENT_CONNECT_ERROR:
265 case RDMA_CM_EVENT_ADDR_ERROR:
266 case RDMA_CM_EVENT_UNREACHABLE:
267 c->status = Disconnected;
268 rdma_disconnect(rdma->cm_id);
269 break;
270 default:
271 BUG();
272 }
273 complete(&rdma->cm_done);
274 return 0;
275}
276
277static void
278handle_recv(struct p9_client *client, struct p9_trans_rdma *rdma,
279 struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
280{
281 struct p9_req_t *req;
282 int err = 0;
283 int16_t tag;
284
285 req = NULL;
286 ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
287 DMA_FROM_DEVICE);
288
289 if (status != IB_WC_SUCCESS)
290 goto err_out;
291
292 err = p9_parse_header(c->rc, NULL, NULL, &tag, 1);
293 if (err)
294 goto err_out;
295
296 req = p9_tag_lookup(client, tag);
297 if (!req)
298 goto err_out;
299
Simon Derr47229ff2013-06-21 15:32:38 +0200300 /* Check that we have not yet received a reply for this request.
301 */
302 if (unlikely(req->rc)) {
303 pr_err("Duplicate reply for request %d", tag);
304 goto err_out;
305 }
306
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500307 req->rc = c->rc;
Latchesar Ionkov1bab88b2009-04-05 16:28:59 -0500308 req->status = REQ_STATUS_RCVD;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500309 p9_client_cb(client, req);
310
311 return;
312
313 err_out:
Joe Perches5d385152011-11-28 10:40:46 -0800314 p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n", req, err, status);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500315 rdma->state = P9_RDMA_FLUSHING;
316 client->status = Disconnected;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500317}
318
319static void
320handle_send(struct p9_client *client, struct p9_trans_rdma *rdma,
321 struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
322{
323 ib_dma_unmap_single(rdma->cm_id->device,
324 c->busa, c->req->tc->size,
325 DMA_TO_DEVICE);
326}
327
328static void qp_event_handler(struct ib_event *event, void *context)
329{
Joe Perches5d385152011-11-28 10:40:46 -0800330 p9_debug(P9_DEBUG_ERROR, "QP event %d context %p\n",
331 event->event, context);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500332}
333
334static void cq_comp_handler(struct ib_cq *cq, void *cq_context)
335{
336 struct p9_client *client = cq_context;
337 struct p9_trans_rdma *rdma = client->trans;
338 int ret;
339 struct ib_wc wc;
340
341 ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
342 while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) {
343 struct p9_rdma_context *c = (void *) (unsigned long) wc.wr_id;
344
345 switch (c->wc_op) {
346 case IB_WC_RECV:
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500347 handle_recv(client, rdma, c, wc.status, wc.byte_len);
Simon Derrfd453d02013-06-21 15:32:39 +0200348 up(&rdma->rq_sem);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500349 break;
350
351 case IB_WC_SEND:
352 handle_send(client, rdma, c, wc.status, wc.byte_len);
353 up(&rdma->sq_sem);
354 break;
355
356 default:
Joe Perches5d385152011-11-28 10:40:46 -0800357 pr_err("unexpected completion type, c->wc_op=%d, wc.opcode=%d, status=%d\n",
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500358 c->wc_op, wc.opcode, wc.status);
359 break;
360 }
361 kfree(c);
362 }
363}
364
365static void cq_event_handler(struct ib_event *e, void *v)
366{
Joe Perches5d385152011-11-28 10:40:46 -0800367 p9_debug(P9_DEBUG_ERROR, "CQ event %d context %p\n", e->event, v);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500368}
369
370static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
371{
372 if (!rdma)
373 return;
374
375 if (rdma->dma_mr && !IS_ERR(rdma->dma_mr))
376 ib_dereg_mr(rdma->dma_mr);
377
378 if (rdma->qp && !IS_ERR(rdma->qp))
379 ib_destroy_qp(rdma->qp);
380
381 if (rdma->pd && !IS_ERR(rdma->pd))
382 ib_dealloc_pd(rdma->pd);
383
384 if (rdma->cq && !IS_ERR(rdma->cq))
385 ib_destroy_cq(rdma->cq);
386
387 if (rdma->cm_id && !IS_ERR(rdma->cm_id))
388 rdma_destroy_id(rdma->cm_id);
389
390 kfree(rdma);
391}
392
393static int
394post_recv(struct p9_client *client, struct p9_rdma_context *c)
395{
396 struct p9_trans_rdma *rdma = client->trans;
397 struct ib_recv_wr wr, *bad_wr;
398 struct ib_sge sge;
399
400 c->busa = ib_dma_map_single(rdma->cm_id->device,
401 c->rc->sdata, client->msize,
402 DMA_FROM_DEVICE);
403 if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
404 goto error;
405
406 sge.addr = c->busa;
407 sge.length = client->msize;
408 sge.lkey = rdma->lkey;
409
410 wr.next = NULL;
411 c->wc_op = IB_WC_RECV;
412 wr.wr_id = (unsigned long) c;
413 wr.sg_list = &sge;
414 wr.num_sge = 1;
415 return ib_post_recv(rdma->qp, &wr, &bad_wr);
416
417 error:
Joe Perches5d385152011-11-28 10:40:46 -0800418 p9_debug(P9_DEBUG_ERROR, "EIO\n");
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500419 return -EIO;
420}
421
422static int rdma_request(struct p9_client *client, struct p9_req_t *req)
423{
424 struct p9_trans_rdma *rdma = client->trans;
425 struct ib_send_wr wr, *bad_wr;
426 struct ib_sge sge;
427 int err = 0;
428 unsigned long flags;
429 struct p9_rdma_context *c = NULL;
430 struct p9_rdma_context *rpl_context = NULL;
431
Simon Derr1cff3302013-06-21 15:32:42 +0200432 /* When an error occurs between posting the recv and the send,
433 * there will be a receive context posted without a pending request.
434 * Since there is no way to "un-post" it, we remember it and skip
435 * post_recv() for the next request.
436 * So here,
437 * see if we are this `next request' and need to absorb an excess rc.
438 * If yes, then drop and free our own, and do not recv_post().
439 **/
440 if (unlikely(atomic_read(&rdma->excess_rc) > 0)) {
441 if ((atomic_sub_return(1, &rdma->excess_rc) >= 0)) {
442 /* Got one ! */
443 kfree(req->rc);
444 req->rc = NULL;
445 goto dont_need_post_recv;
446 } else {
447 /* We raced and lost. */
448 atomic_inc(&rdma->excess_rc);
449 }
450 }
451
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500452 /* Allocate an fcall for the reply */
Aneesh Kumar K.Veeff66e2011-03-08 16:39:47 +0530453 rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS);
Davidlohr Bueso1d6400c2010-09-13 15:53:18 +0000454 if (!rpl_context) {
455 err = -ENOMEM;
Simon Derr2f52d072013-06-21 15:32:41 +0200456 goto recv_error;
Davidlohr Bueso1d6400c2010-09-13 15:53:18 +0000457 }
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500458 rpl_context->rc = req->rc;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500459
460 /*
461 * Post a receive buffer for this request. We need to ensure
462 * there is a reply buffer available for every outstanding
463 * request. A flushed request can result in no reply for an
464 * outstanding request, so we must keep a count to avoid
465 * overflowing the RQ.
466 */
Simon Derr2f52d072013-06-21 15:32:41 +0200467 if (down_interruptible(&rdma->rq_sem)) {
468 err = -EINTR;
469 goto recv_error;
470 }
Simon Derrfd453d02013-06-21 15:32:39 +0200471
472 err = post_recv(client, rpl_context);
473 if (err) {
474 p9_debug(P9_DEBUG_FCALL, "POST RECV failed\n");
Simon Derr2f52d072013-06-21 15:32:41 +0200475 goto recv_error;
Simon Derrfd453d02013-06-21 15:32:39 +0200476 }
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500477 /* remove posted receive buffer from request structure */
478 req->rc = NULL;
479
Simon Derr1cff3302013-06-21 15:32:42 +0200480dont_need_post_recv:
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500481 /* Post the request */
Aneesh Kumar K.Veeff66e2011-03-08 16:39:47 +0530482 c = kmalloc(sizeof *c, GFP_NOFS);
Davidlohr Bueso1d6400c2010-09-13 15:53:18 +0000483 if (!c) {
484 err = -ENOMEM;
Simon Derr2f52d072013-06-21 15:32:41 +0200485 goto send_error;
Davidlohr Bueso1d6400c2010-09-13 15:53:18 +0000486 }
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500487 c->req = req;
488
489 c->busa = ib_dma_map_single(rdma->cm_id->device,
490 c->req->tc->sdata, c->req->tc->size,
491 DMA_TO_DEVICE);
Simon Derr2f52d072013-06-21 15:32:41 +0200492 if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) {
493 err = -EIO;
494 goto send_error;
495 }
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500496
497 sge.addr = c->busa;
498 sge.length = c->req->tc->size;
499 sge.lkey = rdma->lkey;
500
501 wr.next = NULL;
502 c->wc_op = IB_WC_SEND;
503 wr.wr_id = (unsigned long) c;
504 wr.opcode = IB_WR_SEND;
505 wr.send_flags = IB_SEND_SIGNALED;
506 wr.sg_list = &sge;
507 wr.num_sge = 1;
508
Simon Derr2f52d072013-06-21 15:32:41 +0200509 if (down_interruptible(&rdma->sq_sem)) {
510 err = -EINTR;
511 goto send_error;
512 }
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500513
Simon Derr2f52d072013-06-21 15:32:41 +0200514 err = ib_post_send(rdma->qp, &wr, &bad_wr);
515 if (err)
516 goto send_error;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500517
Simon Derr2f52d072013-06-21 15:32:41 +0200518 /* Success */
519 return 0;
520
521 /* Handle errors that happened during or while preparing the send: */
522 send_error:
Davidlohr Bueso1d6400c2010-09-13 15:53:18 +0000523 kfree(c);
Simon Derr2f52d072013-06-21 15:32:41 +0200524 p9_debug(P9_DEBUG_ERROR, "Error %d in rdma_request()\n", err);
Simon Derr1cff3302013-06-21 15:32:42 +0200525
526 /* Ach.
527 * We did recv_post(), but not send. We have one recv_post in excess.
528 */
529 atomic_inc(&rdma->excess_rc);
Simon Derr2f52d072013-06-21 15:32:41 +0200530 return err;
531
532 /* Handle errors that happened during or while preparing post_recv(): */
533 recv_error:
Davidlohr Bueso1d6400c2010-09-13 15:53:18 +0000534 kfree(rpl_context);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500535 spin_lock_irqsave(&rdma->req_lock, flags);
536 if (rdma->state < P9_RDMA_CLOSING) {
537 rdma->state = P9_RDMA_CLOSING;
538 spin_unlock_irqrestore(&rdma->req_lock, flags);
539 rdma_disconnect(rdma->cm_id);
540 } else
541 spin_unlock_irqrestore(&rdma->req_lock, flags);
542 return err;
543}
544
545static void rdma_close(struct p9_client *client)
546{
547 struct p9_trans_rdma *rdma;
548
549 if (!client)
550 return;
551
552 rdma = client->trans;
553 if (!rdma)
554 return;
555
556 client->status = Disconnected;
557 rdma_disconnect(rdma->cm_id);
558 rdma_destroy_trans(rdma);
559}
560
561/**
562 * alloc_rdma - Allocate and initialize the rdma transport structure
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500563 * @opts: Mount options structure
564 */
565static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
566{
567 struct p9_trans_rdma *rdma;
568
569 rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
570 if (!rdma)
571 return NULL;
572
573 rdma->sq_depth = opts->sq_depth;
574 rdma->rq_depth = opts->rq_depth;
575 rdma->timeout = opts->timeout;
576 spin_lock_init(&rdma->req_lock);
577 init_completion(&rdma->cm_done);
578 sema_init(&rdma->sq_sem, rdma->sq_depth);
Simon Derrfd453d02013-06-21 15:32:39 +0200579 sema_init(&rdma->rq_sem, rdma->rq_depth);
Simon Derr1cff3302013-06-21 15:32:42 +0200580 atomic_set(&rdma->excess_rc, 0);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500581
582 return rdma;
583}
584
585/* its not clear to me we can do anything after send has been posted */
586static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
587{
588 return 1;
589}
590
Simon Derr80b45262013-06-21 15:32:43 +0200591/* A request has been fully flushed without a reply.
592 * That means we have posted one buffer in excess.
593 */
594static int rdma_cancelled(struct p9_client *client, struct p9_req_t *req)
595{
596 struct p9_trans_rdma *rdma = client->trans;
597
598 atomic_inc(&rdma->excess_rc);
599 return 0;
600}
601
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500602/**
603 * trans_create_rdma - Transport method for creating atransport instance
604 * @client: client instance
605 * @addr: IP address string
606 * @args: Mount options string
607 */
608static int
609rdma_create_trans(struct p9_client *client, const char *addr, char *args)
610{
611 int err;
612 struct p9_rdma_opts opts;
613 struct p9_trans_rdma *rdma;
614 struct rdma_conn_param conn_param;
615 struct ib_qp_init_attr qp_attr;
616 struct ib_device_attr devattr;
617
618 /* Parse the transport specific mount options */
619 err = parse_opts(args, &opts);
620 if (err < 0)
621 return err;
622
623 /* Create and initialize the RDMA transport structure */
624 rdma = alloc_rdma(&opts);
625 if (!rdma)
626 return -ENOMEM;
627
628 /* Create the RDMA CM ID */
Sean Heftyb26f9b92010-04-01 17:08:41 +0000629 rdma->cm_id = rdma_create_id(p9_cm_event_handler, client, RDMA_PS_TCP,
630 IB_QPT_RC);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500631 if (IS_ERR(rdma->cm_id))
632 goto error;
633
Tom Tucker517ac452008-10-23 16:30:13 -0500634 /* Associate the client with the transport */
635 client->trans = rdma;
636
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500637 /* Resolve the server's address */
638 rdma->addr.sin_family = AF_INET;
639 rdma->addr.sin_addr.s_addr = in_aton(addr);
640 rdma->addr.sin_port = htons(opts.port);
641 err = rdma_resolve_addr(rdma->cm_id, NULL,
642 (struct sockaddr *)&rdma->addr,
643 rdma->timeout);
644 if (err)
645 goto error;
646 err = wait_for_completion_interruptible(&rdma->cm_done);
647 if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
648 goto error;
649
650 /* Resolve the route to the server */
651 err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
652 if (err)
653 goto error;
654 err = wait_for_completion_interruptible(&rdma->cm_done);
655 if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
656 goto error;
657
658 /* Query the device attributes */
659 err = ib_query_device(rdma->cm_id->device, &devattr);
660 if (err)
661 goto error;
662
663 /* Create the Completion Queue */
664 rdma->cq = ib_create_cq(rdma->cm_id->device, cq_comp_handler,
665 cq_event_handler, client,
666 opts.sq_depth + opts.rq_depth + 1, 0);
667 if (IS_ERR(rdma->cq))
668 goto error;
669 ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
670
671 /* Create the Protection Domain */
672 rdma->pd = ib_alloc_pd(rdma->cm_id->device);
673 if (IS_ERR(rdma->pd))
674 goto error;
675
676 /* Cache the DMA lkey in the transport */
677 rdma->dma_mr = NULL;
678 if (devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)
679 rdma->lkey = rdma->cm_id->device->local_dma_lkey;
680 else {
681 rdma->dma_mr = ib_get_dma_mr(rdma->pd, IB_ACCESS_LOCAL_WRITE);
682 if (IS_ERR(rdma->dma_mr))
683 goto error;
684 rdma->lkey = rdma->dma_mr->lkey;
685 }
686
687 /* Create the Queue Pair */
688 memset(&qp_attr, 0, sizeof qp_attr);
689 qp_attr.event_handler = qp_event_handler;
690 qp_attr.qp_context = client;
691 qp_attr.cap.max_send_wr = opts.sq_depth;
692 qp_attr.cap.max_recv_wr = opts.rq_depth;
693 qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
694 qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
695 qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
696 qp_attr.qp_type = IB_QPT_RC;
697 qp_attr.send_cq = rdma->cq;
698 qp_attr.recv_cq = rdma->cq;
699 err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
700 if (err)
701 goto error;
702 rdma->qp = rdma->cm_id->qp;
703
704 /* Request a connection */
705 memset(&conn_param, 0, sizeof(conn_param));
706 conn_param.private_data = NULL;
707 conn_param.private_data_len = 0;
708 conn_param.responder_resources = P9_RDMA_IRD;
709 conn_param.initiator_depth = P9_RDMA_ORD;
710 err = rdma_connect(rdma->cm_id, &conn_param);
711 if (err)
712 goto error;
713 err = wait_for_completion_interruptible(&rdma->cm_done);
714 if (err || (rdma->state != P9_RDMA_CONNECTED))
715 goto error;
716
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500717 client->status = Connected;
718
719 return 0;
720
721error:
722 rdma_destroy_trans(rdma);
723 return -ENOTCONN;
724}
725
726static struct p9_trans_module p9_rdma_trans = {
727 .name = "rdma",
728 .maxsize = P9_RDMA_MAXSIZE,
729 .def = 0,
730 .owner = THIS_MODULE,
731 .create = rdma_create_trans,
732 .close = rdma_close,
733 .request = rdma_request,
734 .cancel = rdma_cancel,
735};
736
737/**
738 * p9_trans_rdma_init - Register the 9P RDMA transport driver
739 */
740static int __init p9_trans_rdma_init(void)
741{
742 v9fs_register_trans(&p9_rdma_trans);
743 return 0;
744}
745
746static void __exit p9_trans_rdma_exit(void)
747{
748 v9fs_unregister_trans(&p9_rdma_trans);
749}
750
751module_init(p9_trans_rdma_init);
752module_exit(p9_trans_rdma_exit);
753
754MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
755MODULE_DESCRIPTION("RDMA Transport for 9P");
756MODULE_LICENSE("Dual BSD/GPL");