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29#include <linux/in.h>
30#include <linux/module.h>
31#include <linux/net.h>
32#include <linux/ipv6.h>
33#include <linux/kthread.h>
34#include <linux/errno.h>
35#include <linux/kernel.h>
36#include <linux/un.h>
37#include <linux/uaccess.h>
38#include <linux/inet.h>
39#include <linux/idr.h>
40#include <linux/file.h>
41#include <linux/parser.h>
42#include <linux/semaphore.h>
43#include <net/9p/9p.h>
44#include <net/9p/client.h>
45#include <net/9p/transport.h>
46#include <rdma/ib_verbs.h>
47#include <rdma/rdma_cm.h>
48
49#define P9_PORT 5640
50#define P9_RDMA_SQ_DEPTH 32
51#define P9_RDMA_RQ_DEPTH 32
52#define P9_RDMA_SEND_SGE 4
53#define P9_RDMA_RECV_SGE 4
54#define P9_RDMA_IRD 0
55#define P9_RDMA_ORD 0
56#define P9_RDMA_TIMEOUT 30000
57#define P9_RDMA_MAXSIZE (4*4096)
58
59
60
61#define P9_RDMA_MAX_SGE (P9_RDMA_MAXSIZE >> PAGE_SHIFT)
62
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80
81struct p9_trans_rdma {
82 enum {
83 P9_RDMA_INIT,
84 P9_RDMA_ADDR_RESOLVED,
85 P9_RDMA_ROUTE_RESOLVED,
86 P9_RDMA_CONNECTED,
87 P9_RDMA_FLUSHING,
88 P9_RDMA_CLOSING,
89 P9_RDMA_CLOSED,
90 } state;
91 struct rdma_cm_id *cm_id;
92 struct ib_pd *pd;
93 struct ib_qp *qp;
94 struct ib_cq *cq;
95 struct ib_mr *dma_mr;
96 u32 lkey;
97 long timeout;
98 int sq_depth;
99 struct semaphore sq_sem;
100 int rq_depth;
101 atomic_t rq_count;
102 struct sockaddr_in addr;
103 spinlock_t req_lock;
104
105 struct completion cm_done;
106};
107
108
109
110
111
112
113
114
115
116struct p9_rdma_req;
117struct p9_rdma_context {
118 enum ib_wc_opcode wc_op;
119 dma_addr_t busa;
120 union {
121 struct p9_req_t *req;
122 struct p9_fcall *rc;
123 };
124};
125
126
127
128
129
130
131
132
133
134struct p9_rdma_opts {
135 short port;
136 int sq_depth;
137 int rq_depth;
138 long timeout;
139};
140
141
142
143
144enum {
145
146 Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout, Opt_err,
147};
148
149static match_table_t tokens = {
150 {Opt_port, "port=%u"},
151 {Opt_sq_depth, "sq=%u"},
152 {Opt_rq_depth, "rq=%u"},
153 {Opt_timeout, "timeout=%u"},
154 {Opt_err, NULL},
155};
156
157
158
159
160
161
162
163
164static int parse_opts(char *params, struct p9_rdma_opts *opts)
165{
166 char *p;
167 substring_t args[MAX_OPT_ARGS];
168 int option;
169 char *options;
170 int ret;
171
172 opts->port = P9_PORT;
173 opts->sq_depth = P9_RDMA_SQ_DEPTH;
174 opts->rq_depth = P9_RDMA_RQ_DEPTH;
175 opts->timeout = P9_RDMA_TIMEOUT;
176
177 if (!params)
178 return 0;
179
180 options = kstrdup(params, GFP_KERNEL);
181 if (!options) {
182 P9_DPRINTK(P9_DEBUG_ERROR,
183 "failed to allocate copy of option string\n");
184 return -ENOMEM;
185 }
186
187 while ((p = strsep(&options, ",")) != NULL) {
188 int token;
189 int r;
190 if (!*p)
191 continue;
192 token = match_token(p, tokens, args);
193 r = match_int(&args[0], &option);
194 if (r < 0) {
195 P9_DPRINTK(P9_DEBUG_ERROR,
196 "integer field, but no integer?\n");
197 ret = r;
198 continue;
199 }
200 switch (token) {
201 case Opt_port:
202 opts->port = option;
203 break;
204 case Opt_sq_depth:
205 opts->sq_depth = option;
206 break;
207 case Opt_rq_depth:
208 opts->rq_depth = option;
209 break;
210 case Opt_timeout:
211 opts->timeout = option;
212 break;
213 default:
214 continue;
215 }
216 }
217
218 opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
219 kfree(options);
220 return 0;
221}
222
223static int
224p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
225{
226 struct p9_client *c = id->context;
227 struct p9_trans_rdma *rdma = c->trans;
228 switch (event->event) {
229 case RDMA_CM_EVENT_ADDR_RESOLVED:
230 BUG_ON(rdma->state != P9_RDMA_INIT);
231 rdma->state = P9_RDMA_ADDR_RESOLVED;
232 break;
233
234 case RDMA_CM_EVENT_ROUTE_RESOLVED:
235 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
236 rdma->state = P9_RDMA_ROUTE_RESOLVED;
237 break;
238
239 case RDMA_CM_EVENT_ESTABLISHED:
240 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
241 rdma->state = P9_RDMA_CONNECTED;
242 break;
243
244 case RDMA_CM_EVENT_DISCONNECTED:
245 if (rdma)
246 rdma->state = P9_RDMA_CLOSED;
247 if (c)
248 c->status = Disconnected;
249 break;
250
251 case RDMA_CM_EVENT_TIMEWAIT_EXIT:
252 break;
253
254 case RDMA_CM_EVENT_ADDR_CHANGE:
255 case RDMA_CM_EVENT_ROUTE_ERROR:
256 case RDMA_CM_EVENT_DEVICE_REMOVAL:
257 case RDMA_CM_EVENT_MULTICAST_JOIN:
258 case RDMA_CM_EVENT_MULTICAST_ERROR:
259 case RDMA_CM_EVENT_REJECTED:
260 case RDMA_CM_EVENT_CONNECT_REQUEST:
261 case RDMA_CM_EVENT_CONNECT_RESPONSE:
262 case RDMA_CM_EVENT_CONNECT_ERROR:
263 case RDMA_CM_EVENT_ADDR_ERROR:
264 case RDMA_CM_EVENT_UNREACHABLE:
265 c->status = Disconnected;
266 rdma_disconnect(rdma->cm_id);
267 break;
268 default:
269 BUG();
270 }
271 complete(&rdma->cm_done);
272 return 0;
273}
274
275static void
276handle_recv(struct p9_client *client, struct p9_trans_rdma *rdma,
277 struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
278{
279 struct p9_req_t *req;
280 int err = 0;
281 int16_t tag;
282
283 req = NULL;
284 ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
285 DMA_FROM_DEVICE);
286
287 if (status != IB_WC_SUCCESS)
288 goto err_out;
289
290 err = p9_parse_header(c->rc, NULL, NULL, &tag, 1);
291 if (err)
292 goto err_out;
293
294 req = p9_tag_lookup(client, tag);
295 if (!req)
296 goto err_out;
297
298 req->rc = c->rc;
299 req->status = REQ_STATUS_RCVD;
300 p9_client_cb(client, req);
301
302 return;
303
304 err_out:
305 P9_DPRINTK(P9_DEBUG_ERROR, "req %p err %d status %d\n",
306 req, err, status);
307 rdma->state = P9_RDMA_FLUSHING;
308 client->status = Disconnected;
309 return;
310}
311
312static void
313handle_send(struct p9_client *client, struct p9_trans_rdma *rdma,
314 struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
315{
316 ib_dma_unmap_single(rdma->cm_id->device,
317 c->busa, c->req->tc->size,
318 DMA_TO_DEVICE);
319}
320
321static void qp_event_handler(struct ib_event *event, void *context)
322{
323 P9_DPRINTK(P9_DEBUG_ERROR, "QP event %d context %p\n", event->event,
324 context);
325}
326
327static void cq_comp_handler(struct ib_cq *cq, void *cq_context)
328{
329 struct p9_client *client = cq_context;
330 struct p9_trans_rdma *rdma = client->trans;
331 int ret;
332 struct ib_wc wc;
333
334 ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
335 while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) {
336 struct p9_rdma_context *c = (void *) (unsigned long) wc.wr_id;
337
338 switch (c->wc_op) {
339 case IB_WC_RECV:
340 atomic_dec(&rdma->rq_count);
341 handle_recv(client, rdma, c, wc.status, wc.byte_len);
342 break;
343
344 case IB_WC_SEND:
345 handle_send(client, rdma, c, wc.status, wc.byte_len);
346 up(&rdma->sq_sem);
347 break;
348
349 default:
350 printk(KERN_ERR "9prdma: unexpected completion type, "
351 "c->wc_op=%d, wc.opcode=%d, status=%d\n",
352 c->wc_op, wc.opcode, wc.status);
353 break;
354 }
355 kfree(c);
356 }
357}
358
359static void cq_event_handler(struct ib_event *e, void *v)
360{
361 P9_DPRINTK(P9_DEBUG_ERROR, "CQ event %d context %p\n", e->event, v);
362}
363
364static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
365{
366 if (!rdma)
367 return;
368
369 if (rdma->dma_mr && !IS_ERR(rdma->dma_mr))
370 ib_dereg_mr(rdma->dma_mr);
371
372 if (rdma->qp && !IS_ERR(rdma->qp))
373 ib_destroy_qp(rdma->qp);
374
375 if (rdma->pd && !IS_ERR(rdma->pd))
376 ib_dealloc_pd(rdma->pd);
377
378 if (rdma->cq && !IS_ERR(rdma->cq))
379 ib_destroy_cq(rdma->cq);
380
381 if (rdma->cm_id && !IS_ERR(rdma->cm_id))
382 rdma_destroy_id(rdma->cm_id);
383
384 kfree(rdma);
385}
386
387static int
388post_recv(struct p9_client *client, struct p9_rdma_context *c)
389{
390 struct p9_trans_rdma *rdma = client->trans;
391 struct ib_recv_wr wr, *bad_wr;
392 struct ib_sge sge;
393
394 c->busa = ib_dma_map_single(rdma->cm_id->device,
395 c->rc->sdata, client->msize,
396 DMA_FROM_DEVICE);
397 if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
398 goto error;
399
400 sge.addr = c->busa;
401 sge.length = client->msize;
402 sge.lkey = rdma->lkey;
403
404 wr.next = NULL;
405 c->wc_op = IB_WC_RECV;
406 wr.wr_id = (unsigned long) c;
407 wr.sg_list = &sge;
408 wr.num_sge = 1;
409 return ib_post_recv(rdma->qp, &wr, &bad_wr);
410
411 error:
412 P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
413 return -EIO;
414}
415
416static int rdma_request(struct p9_client *client, struct p9_req_t *req)
417{
418 struct p9_trans_rdma *rdma = client->trans;
419 struct ib_send_wr wr, *bad_wr;
420 struct ib_sge sge;
421 int err = 0;
422 unsigned long flags;
423 struct p9_rdma_context *c = NULL;
424 struct p9_rdma_context *rpl_context = NULL;
425
426
427 rpl_context = kmalloc(sizeof *rpl_context, GFP_KERNEL);
428 if (!rpl_context)
429 goto err_close;
430
431
432
433
434
435
436 if (!req->rc) {
437 req->rc = kmalloc(sizeof(struct p9_fcall)+client->msize,
438 GFP_KERNEL);
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 kfree(rpl_context);
448 goto err_close;
449 }
450
451
452
453
454
455
456
457
458 if (atomic_inc_return(&rdma->rq_count) <= rdma->rq_depth) {
459 err = post_recv(client, rpl_context);
460 if (err) {
461 kfree(rpl_context->rc);
462 kfree(rpl_context);
463 goto err_close;
464 }
465 } else
466 atomic_dec(&rdma->rq_count);
467
468
469 req->rc = NULL;
470
471
472 c = kmalloc(sizeof *c, GFP_KERNEL);
473 if (!c)
474 goto err_close;
475 c->req = req;
476
477 c->busa = ib_dma_map_single(rdma->cm_id->device,
478 c->req->tc->sdata, c->req->tc->size,
479 DMA_TO_DEVICE);
480 if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
481 goto error;
482
483 sge.addr = c->busa;
484 sge.length = c->req->tc->size;
485 sge.lkey = rdma->lkey;
486
487 wr.next = NULL;
488 c->wc_op = IB_WC_SEND;
489 wr.wr_id = (unsigned long) c;
490 wr.opcode = IB_WR_SEND;
491 wr.send_flags = IB_SEND_SIGNALED;
492 wr.sg_list = &sge;
493 wr.num_sge = 1;
494
495 if (down_interruptible(&rdma->sq_sem))
496 goto error;
497
498 return ib_post_send(rdma->qp, &wr, &bad_wr);
499
500 error:
501 P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
502 return -EIO;
503
504 err_close:
505 spin_lock_irqsave(&rdma->req_lock, flags);
506 if (rdma->state < P9_RDMA_CLOSING) {
507 rdma->state = P9_RDMA_CLOSING;
508 spin_unlock_irqrestore(&rdma->req_lock, flags);
509 rdma_disconnect(rdma->cm_id);
510 } else
511 spin_unlock_irqrestore(&rdma->req_lock, flags);
512 return err;
513}
514
515static void rdma_close(struct p9_client *client)
516{
517 struct p9_trans_rdma *rdma;
518
519 if (!client)
520 return;
521
522 rdma = client->trans;
523 if (!rdma)
524 return;
525
526 client->status = Disconnected;
527 rdma_disconnect(rdma->cm_id);
528 rdma_destroy_trans(rdma);
529}
530
531
532
533
534
535static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
536{
537 struct p9_trans_rdma *rdma;
538
539 rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
540 if (!rdma)
541 return NULL;
542
543 rdma->sq_depth = opts->sq_depth;
544 rdma->rq_depth = opts->rq_depth;
545 rdma->timeout = opts->timeout;
546 spin_lock_init(&rdma->req_lock);
547 init_completion(&rdma->cm_done);
548 sema_init(&rdma->sq_sem, rdma->sq_depth);
549 atomic_set(&rdma->rq_count, 0);
550
551 return rdma;
552}
553
554
555static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
556{
557 return 1;
558}
559
560
561
562
563
564
565
566static int
567rdma_create_trans(struct p9_client *client, const char *addr, char *args)
568{
569 int err;
570 struct p9_rdma_opts opts;
571 struct p9_trans_rdma *rdma;
572 struct rdma_conn_param conn_param;
573 struct ib_qp_init_attr qp_attr;
574 struct ib_device_attr devattr;
575
576
577 err = parse_opts(args, &opts);
578 if (err < 0)
579 return err;
580
581
582 rdma = alloc_rdma(&opts);
583 if (!rdma)
584 return -ENOMEM;
585
586
587 rdma->cm_id = rdma_create_id(p9_cm_event_handler, client, RDMA_PS_TCP);
588 if (IS_ERR(rdma->cm_id))
589 goto error;
590
591
592 client->trans = rdma;
593
594
595 rdma->addr.sin_family = AF_INET;
596 rdma->addr.sin_addr.s_addr = in_aton(addr);
597 rdma->addr.sin_port = htons(opts.port);
598 err = rdma_resolve_addr(rdma->cm_id, NULL,
599 (struct sockaddr *)&rdma->addr,
600 rdma->timeout);
601 if (err)
602 goto error;
603 err = wait_for_completion_interruptible(&rdma->cm_done);
604 if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
605 goto error;
606
607
608 err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
609 if (err)
610 goto error;
611 err = wait_for_completion_interruptible(&rdma->cm_done);
612 if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
613 goto error;
614
615
616 err = ib_query_device(rdma->cm_id->device, &devattr);
617 if (err)
618 goto error;
619
620
621 rdma->cq = ib_create_cq(rdma->cm_id->device, cq_comp_handler,
622 cq_event_handler, client,
623 opts.sq_depth + opts.rq_depth + 1, 0);
624 if (IS_ERR(rdma->cq))
625 goto error;
626 ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
627
628
629 rdma->pd = ib_alloc_pd(rdma->cm_id->device);
630 if (IS_ERR(rdma->pd))
631 goto error;
632
633
634 rdma->dma_mr = NULL;
635 if (devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)
636 rdma->lkey = rdma->cm_id->device->local_dma_lkey;
637 else {
638 rdma->dma_mr = ib_get_dma_mr(rdma->pd, IB_ACCESS_LOCAL_WRITE);
639 if (IS_ERR(rdma->dma_mr))
640 goto error;
641 rdma->lkey = rdma->dma_mr->lkey;
642 }
643
644
645 memset(&qp_attr, 0, sizeof qp_attr);
646 qp_attr.event_handler = qp_event_handler;
647 qp_attr.qp_context = client;
648 qp_attr.cap.max_send_wr = opts.sq_depth;
649 qp_attr.cap.max_recv_wr = opts.rq_depth;
650 qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
651 qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
652 qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
653 qp_attr.qp_type = IB_QPT_RC;
654 qp_attr.send_cq = rdma->cq;
655 qp_attr.recv_cq = rdma->cq;
656 err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
657 if (err)
658 goto error;
659 rdma->qp = rdma->cm_id->qp;
660
661
662 memset(&conn_param, 0, sizeof(conn_param));
663 conn_param.private_data = NULL;
664 conn_param.private_data_len = 0;
665 conn_param.responder_resources = P9_RDMA_IRD;
666 conn_param.initiator_depth = P9_RDMA_ORD;
667 err = rdma_connect(rdma->cm_id, &conn_param);
668 if (err)
669 goto error;
670 err = wait_for_completion_interruptible(&rdma->cm_done);
671 if (err || (rdma->state != P9_RDMA_CONNECTED))
672 goto error;
673
674 client->status = Connected;
675
676 return 0;
677
678error:
679 rdma_destroy_trans(rdma);
680 return -ENOTCONN;
681}
682
683static struct p9_trans_module p9_rdma_trans = {
684 .name = "rdma",
685 .maxsize = P9_RDMA_MAXSIZE,
686 .def = 0,
687 .owner = THIS_MODULE,
688 .create = rdma_create_trans,
689 .close = rdma_close,
690 .request = rdma_request,
691 .cancel = rdma_cancel,
692};
693
694
695
696
697static int __init p9_trans_rdma_init(void)
698{
699 v9fs_register_trans(&p9_rdma_trans);
700 return 0;
701}
702
703static void __exit p9_trans_rdma_exit(void)
704{
705 v9fs_unregister_trans(&p9_rdma_trans);
706}
707
708module_init(p9_trans_rdma_init);
709module_exit(p9_trans_rdma_exit);
710
711MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
712MODULE_DESCRIPTION("RDMA Transport for 9P");
713MODULE_LICENSE("Dual BSD/GPL");
714