1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * RDMA Transport Layer
4 *
5 * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
6 * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
7 * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
8 */
9
10#undef pr_fmt
11#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
12
13#include <linux/module.h>
14#include <linux/mempool.h>
15
16#include "rtrs-srv.h"
17#include "rtrs-log.h"
18#include <rdma/ib_cm.h>
19#include <rdma/ib_verbs.h>
20
21MODULE_DESCRIPTION("RDMA Transport Server");
22MODULE_LICENSE("GPL");
23
24/* Must be power of 2, see mask from mr->page_size in ib_sg_to_pages() */
25#define DEFAULT_MAX_CHUNK_SIZE (128 << 10)
26#define DEFAULT_SESS_QUEUE_DEPTH 512
27#define MAX_HDR_SIZE PAGE_SIZE
28
29/* We guarantee to serve 10 paths at least */
30#define CHUNK_POOL_SZ 10
31
32static struct rtrs_rdma_dev_pd dev_pd;
33static mempool_t *chunk_pool;
34struct class *rtrs_dev_class;
35static struct rtrs_srv_ib_ctx ib_ctx;
36
37static int __read_mostly max_chunk_size = DEFAULT_MAX_CHUNK_SIZE;
38static int __read_mostly sess_queue_depth = DEFAULT_SESS_QUEUE_DEPTH;
39
40static bool always_invalidate = true;
41module_param(always_invalidate, bool, 0444);
42MODULE_PARM_DESC(always_invalidate,
43		 "Invalidate memory registration for contiguous memory regions before accessing.");
44
45module_param_named(max_chunk_size, max_chunk_size, int, 0444);
46MODULE_PARM_DESC(max_chunk_size,
47		 "Max size for each IO request, when change the unit is in byte (default: "
48		 __stringify(DEFAULT_MAX_CHUNK_SIZE) "KB)");
49
50module_param_named(sess_queue_depth, sess_queue_depth, int, 0444);
51MODULE_PARM_DESC(sess_queue_depth,
52		 "Number of buffers for pending I/O requests to allocate per session. Maximum: "
53		 __stringify(MAX_SESS_QUEUE_DEPTH) " (default: "
54		 __stringify(DEFAULT_SESS_QUEUE_DEPTH) ")");
55
56static cpumask_t cq_affinity_mask = { CPU_BITS_ALL };
57
58static struct workqueue_struct *rtrs_wq;
59
60static inline struct rtrs_srv_con *to_srv_con(struct rtrs_con *c)
61{
62	return container_of(c, struct rtrs_srv_con, c);
63}
64
65static inline struct rtrs_srv_sess *to_srv_sess(struct rtrs_sess *s)
66{
67	return container_of(s, struct rtrs_srv_sess, s);
68}
69
70static bool __rtrs_srv_change_state(struct rtrs_srv_sess *sess,
71				     enum rtrs_srv_state new_state)
72{
73	enum rtrs_srv_state old_state;
74	bool changed = false;
75
76	lockdep_assert_held(&sess->state_lock);
77	old_state = sess->state;
78	switch (new_state) {
79	case RTRS_SRV_CONNECTED:
80		switch (old_state) {
81		case RTRS_SRV_CONNECTING:
82			changed = true;
83			fallthrough;
84		default:
85			break;
86		}
87		break;
88	case RTRS_SRV_CLOSING:
89		switch (old_state) {
90		case RTRS_SRV_CONNECTING:
91		case RTRS_SRV_CONNECTED:
92			changed = true;
93			fallthrough;
94		default:
95			break;
96		}
97		break;
98	case RTRS_SRV_CLOSED:
99		switch (old_state) {
100		case RTRS_SRV_CLOSING:
101			changed = true;
102			fallthrough;
103		default:
104			break;
105		}
106		break;
107	default:
108		break;
109	}
110	if (changed)
111		sess->state = new_state;
112
113	return changed;
114}
115
116static bool rtrs_srv_change_state_get_old(struct rtrs_srv_sess *sess,
117					   enum rtrs_srv_state new_state,
118					   enum rtrs_srv_state *old_state)
119{
120	bool changed;
121
122	spin_lock_irq(&sess->state_lock);
123	*old_state = sess->state;
124	changed = __rtrs_srv_change_state(sess, new_state);
125	spin_unlock_irq(&sess->state_lock);
126
127	return changed;
128}
129
130static bool rtrs_srv_change_state(struct rtrs_srv_sess *sess,
131				   enum rtrs_srv_state new_state)
132{
133	enum rtrs_srv_state old_state;
134
135	return rtrs_srv_change_state_get_old(sess, new_state, &old_state);
136}
137
138static void free_id(struct rtrs_srv_op *id)
139{
140	if (!id)
141		return;
142	kfree(id);
143}
144
145static void rtrs_srv_free_ops_ids(struct rtrs_srv_sess *sess)
146{
147	struct rtrs_srv *srv = sess->srv;
148	int i;
149
150	WARN_ON(atomic_read(&sess->ids_inflight));
151	if (sess->ops_ids) {
152		for (i = 0; i < srv->queue_depth; i++)
153			free_id(sess->ops_ids[i]);
154		kfree(sess->ops_ids);
155		sess->ops_ids = NULL;
156	}
157}
158
159static void rtrs_srv_rdma_done(struct ib_cq *cq, struct ib_wc *wc);
160
161static struct ib_cqe io_comp_cqe = {
162	.done = rtrs_srv_rdma_done
163};
164
165static int rtrs_srv_alloc_ops_ids(struct rtrs_srv_sess *sess)
166{
167	struct rtrs_srv *srv = sess->srv;
168	struct rtrs_srv_op *id;
169	int i;
170
171	sess->ops_ids = kcalloc(srv->queue_depth, sizeof(*sess->ops_ids),
172				GFP_KERNEL);
173	if (!sess->ops_ids)
174		goto err;
175
176	for (i = 0; i < srv->queue_depth; ++i) {
177		id = kzalloc(sizeof(*id), GFP_KERNEL);
178		if (!id)
179			goto err;
180
181		sess->ops_ids[i] = id;
182	}
183	init_waitqueue_head(&sess->ids_waitq);
184	atomic_set(&sess->ids_inflight, 0);
185
186	return 0;
187
188err:
189	rtrs_srv_free_ops_ids(sess);
190	return -ENOMEM;
191}
192
193static inline void rtrs_srv_get_ops_ids(struct rtrs_srv_sess *sess)
194{
195	atomic_inc(&sess->ids_inflight);
196}
197
198static inline void rtrs_srv_put_ops_ids(struct rtrs_srv_sess *sess)
199{
200	if (atomic_dec_and_test(&sess->ids_inflight))
201		wake_up(&sess->ids_waitq);
202}
203
204static void rtrs_srv_wait_ops_ids(struct rtrs_srv_sess *sess)
205{
206	wait_event(sess->ids_waitq, !atomic_read(&sess->ids_inflight));
207}
208
209
210static void rtrs_srv_reg_mr_done(struct ib_cq *cq, struct ib_wc *wc)
211{
212	struct rtrs_srv_con *con = cq->cq_context;
213	struct rtrs_sess *s = con->c.sess;
214	struct rtrs_srv_sess *sess = to_srv_sess(s);
215
216	if (unlikely(wc->status != IB_WC_SUCCESS)) {
217		rtrs_err(s, "REG MR failed: %s\n",
218			  ib_wc_status_msg(wc->status));
219		close_sess(sess);
220		return;
221	}
222}
223
224static struct ib_cqe local_reg_cqe = {
225	.done = rtrs_srv_reg_mr_done
226};
227
228static int rdma_write_sg(struct rtrs_srv_op *id)
229{
230	struct rtrs_sess *s = id->con->c.sess;
231	struct rtrs_srv_sess *sess = to_srv_sess(s);
232	dma_addr_t dma_addr = sess->dma_addr[id->msg_id];
233	struct rtrs_srv_mr *srv_mr;
234	struct rtrs_srv *srv = sess->srv;
235	struct ib_send_wr inv_wr;
236	struct ib_rdma_wr imm_wr;
237	struct ib_rdma_wr *wr = NULL;
238	enum ib_send_flags flags;
239	size_t sg_cnt;
240	int err, offset;
241	bool need_inval;
242	u32 rkey = 0;
243	struct ib_reg_wr rwr;
244	struct ib_sge *plist;
245	struct ib_sge list;
246
247	sg_cnt = le16_to_cpu(id->rd_msg->sg_cnt);
248	need_inval = le16_to_cpu(id->rd_msg->flags) & RTRS_MSG_NEED_INVAL_F;
249	if (unlikely(sg_cnt != 1))
250		return -EINVAL;
251
252	offset = 0;
253
254	wr		= &id->tx_wr;
255	plist		= &id->tx_sg;
256	plist->addr	= dma_addr + offset;
257	plist->length	= le32_to_cpu(id->rd_msg->desc[0].len);
258
259	/* WR will fail with length error
260	 * if this is 0
261	 */
262	if (unlikely(plist->length == 0)) {
263		rtrs_err(s, "Invalid RDMA-Write sg list length 0\n");
264		return -EINVAL;
265	}
266
267	plist->lkey = sess->s.dev->ib_pd->local_dma_lkey;
268	offset += plist->length;
269
270	wr->wr.sg_list	= plist;
271	wr->wr.num_sge	= 1;
272	wr->remote_addr	= le64_to_cpu(id->rd_msg->desc[0].addr);
273	wr->rkey	= le32_to_cpu(id->rd_msg->desc[0].key);
274	if (rkey == 0)
275		rkey = wr->rkey;
276	else
277		/* Only one key is actually used */
278		WARN_ON_ONCE(rkey != wr->rkey);
279
280	wr->wr.opcode = IB_WR_RDMA_WRITE;
281	wr->wr.wr_cqe   = &io_comp_cqe;
282	wr->wr.ex.imm_data = 0;
283	wr->wr.send_flags  = 0;
284
285	if (need_inval && always_invalidate) {
286		wr->wr.next = &rwr.wr;
287		rwr.wr.next = &inv_wr;
288		inv_wr.next = &imm_wr.wr;
289	} else if (always_invalidate) {
290		wr->wr.next = &rwr.wr;
291		rwr.wr.next = &imm_wr.wr;
292	} else if (need_inval) {
293		wr->wr.next = &inv_wr;
294		inv_wr.next = &imm_wr.wr;
295	} else {
296		wr->wr.next = &imm_wr.wr;
297	}
298	/*
299	 * From time to time we have to post signaled sends,
300	 * or send queue will fill up and only QP reset can help.
301	 */
302	flags = (atomic_inc_return(&id->con->wr_cnt) % srv->queue_depth) ?
303		0 : IB_SEND_SIGNALED;
304
305	if (need_inval) {
306		inv_wr.sg_list = NULL;
307		inv_wr.num_sge = 0;
308		inv_wr.opcode = IB_WR_SEND_WITH_INV;
309		inv_wr.wr_cqe   = &io_comp_cqe;
310		inv_wr.send_flags = 0;
311		inv_wr.ex.invalidate_rkey = rkey;
312	}
313
314	imm_wr.wr.next = NULL;
315	if (always_invalidate) {
316		struct rtrs_msg_rkey_rsp *msg;
317
318		srv_mr = &sess->mrs[id->msg_id];
319		rwr.wr.opcode = IB_WR_REG_MR;
320		rwr.wr.wr_cqe = &local_reg_cqe;
321		rwr.wr.num_sge = 0;
322		rwr.mr = srv_mr->mr;
323		rwr.wr.send_flags = 0;
324		rwr.key = srv_mr->mr->rkey;
325		rwr.access = (IB_ACCESS_LOCAL_WRITE |
326			      IB_ACCESS_REMOTE_WRITE);
327		msg = srv_mr->iu->buf;
328		msg->buf_id = cpu_to_le16(id->msg_id);
329		msg->type = cpu_to_le16(RTRS_MSG_RKEY_RSP);
330		msg->rkey = cpu_to_le32(srv_mr->mr->rkey);
331
332		list.addr   = srv_mr->iu->dma_addr;
333		list.length = sizeof(*msg);
334		list.lkey   = sess->s.dev->ib_pd->local_dma_lkey;
335		imm_wr.wr.sg_list = &list;
336		imm_wr.wr.num_sge = 1;
337		imm_wr.wr.opcode = IB_WR_SEND_WITH_IMM;
338		ib_dma_sync_single_for_device(sess->s.dev->ib_dev,
339					      srv_mr->iu->dma_addr,
340					      srv_mr->iu->size, DMA_TO_DEVICE);
341	} else {
342		imm_wr.wr.sg_list = NULL;
343		imm_wr.wr.num_sge = 0;
344		imm_wr.wr.opcode = IB_WR_RDMA_WRITE_WITH_IMM;
345	}
346	imm_wr.wr.send_flags = flags;
347	imm_wr.wr.ex.imm_data = cpu_to_be32(rtrs_to_io_rsp_imm(id->msg_id,
348							     0, need_inval));
349
350	imm_wr.wr.wr_cqe   = &io_comp_cqe;
351	ib_dma_sync_single_for_device(sess->s.dev->ib_dev, dma_addr,
352				      offset, DMA_BIDIRECTIONAL);
353
354	err = ib_post_send(id->con->c.qp, &id->tx_wr.wr, NULL);
355	if (unlikely(err))
356		rtrs_err(s,
357			  "Posting RDMA-Write-Request to QP failed, err: %d\n",
358			  err);
359
360	return err;
361}
362
363/**
364 * send_io_resp_imm() - respond to client with empty IMM on failed READ/WRITE
365 *                      requests or on successful WRITE request.
366 * @con:	the connection to send back result
367 * @id:		the id associated with the IO
368 * @errno:	the error number of the IO.
369 *
370 * Return 0 on success, errno otherwise.
371 */
372static int send_io_resp_imm(struct rtrs_srv_con *con, struct rtrs_srv_op *id,
373			    int errno)
374{
375	struct rtrs_sess *s = con->c.sess;
376	struct rtrs_srv_sess *sess = to_srv_sess(s);
377	struct ib_send_wr inv_wr, *wr = NULL;
378	struct ib_rdma_wr imm_wr;
379	struct ib_reg_wr rwr;
380	struct rtrs_srv *srv = sess->srv;
381	struct rtrs_srv_mr *srv_mr;
382	bool need_inval = false;
383	enum ib_send_flags flags;
384	u32 imm;
385	int err;
386
387	if (id->dir == READ) {
388		struct rtrs_msg_rdma_read *rd_msg = id->rd_msg;
389		size_t sg_cnt;
390
391		need_inval = le16_to_cpu(rd_msg->flags) &
392				RTRS_MSG_NEED_INVAL_F;
393		sg_cnt = le16_to_cpu(rd_msg->sg_cnt);
394
395		if (need_inval) {
396			if (likely(sg_cnt)) {
397				inv_wr.wr_cqe   = &io_comp_cqe;
398				inv_wr.sg_list = NULL;
399				inv_wr.num_sge = 0;
400				inv_wr.opcode = IB_WR_SEND_WITH_INV;
401				inv_wr.send_flags = 0;
402				/* Only one key is actually used */
403				inv_wr.ex.invalidate_rkey =
404					le32_to_cpu(rd_msg->desc[0].key);
405			} else {
406				WARN_ON_ONCE(1);
407				need_inval = false;
408			}
409		}
410	}
411
412	if (need_inval && always_invalidate) {
413		wr = &inv_wr;
414		inv_wr.next = &rwr.wr;
415		rwr.wr.next = &imm_wr.wr;
416	} else if (always_invalidate) {
417		wr = &rwr.wr;
418		rwr.wr.next = &imm_wr.wr;
419	} else if (need_inval) {
420		wr = &inv_wr;
421		inv_wr.next = &imm_wr.wr;
422	} else {
423		wr = &imm_wr.wr;
424	}
425	/*
426	 * From time to time we have to post signalled sends,
427	 * or send queue will fill up and only QP reset can help.
428	 */
429	flags = (atomic_inc_return(&con->wr_cnt) % srv->queue_depth) ?
430		0 : IB_SEND_SIGNALED;
431	imm = rtrs_to_io_rsp_imm(id->msg_id, errno, need_inval);
432	imm_wr.wr.next = NULL;
433	if (always_invalidate) {
434		struct ib_sge list;
435		struct rtrs_msg_rkey_rsp *msg;
436
437		srv_mr = &sess->mrs[id->msg_id];
438		rwr.wr.next = &imm_wr.wr;
439		rwr.wr.opcode = IB_WR_REG_MR;
440		rwr.wr.wr_cqe = &local_reg_cqe;
441		rwr.wr.num_sge = 0;
442		rwr.wr.send_flags = 0;
443		rwr.mr = srv_mr->mr;
444		rwr.key = srv_mr->mr->rkey;
445		rwr.access = (IB_ACCESS_LOCAL_WRITE |
446			      IB_ACCESS_REMOTE_WRITE);
447		msg = srv_mr->iu->buf;
448		msg->buf_id = cpu_to_le16(id->msg_id);
449		msg->type = cpu_to_le16(RTRS_MSG_RKEY_RSP);
450		msg->rkey = cpu_to_le32(srv_mr->mr->rkey);
451
452		list.addr   = srv_mr->iu->dma_addr;
453		list.length = sizeof(*msg);
454		list.lkey   = sess->s.dev->ib_pd->local_dma_lkey;
455		imm_wr.wr.sg_list = &list;
456		imm_wr.wr.num_sge = 1;
457		imm_wr.wr.opcode = IB_WR_SEND_WITH_IMM;
458		ib_dma_sync_single_for_device(sess->s.dev->ib_dev,
459					      srv_mr->iu->dma_addr,
460					      srv_mr->iu->size, DMA_TO_DEVICE);
461	} else {
462		imm_wr.wr.sg_list = NULL;
463		imm_wr.wr.num_sge = 0;
464		imm_wr.wr.opcode = IB_WR_RDMA_WRITE_WITH_IMM;
465	}
466	imm_wr.wr.send_flags = flags;
467	imm_wr.wr.wr_cqe   = &io_comp_cqe;
468
469	imm_wr.wr.ex.imm_data = cpu_to_be32(imm);
470
471	err = ib_post_send(id->con->c.qp, wr, NULL);
472	if (unlikely(err))
473		rtrs_err_rl(s, "Posting RDMA-Reply to QP failed, err: %d\n",
474			     err);
475
476	return err;
477}
478
479void close_sess(struct rtrs_srv_sess *sess)
480{
481	enum rtrs_srv_state old_state;
482
483	if (rtrs_srv_change_state_get_old(sess, RTRS_SRV_CLOSING,
484					   &old_state))
485		queue_work(rtrs_wq, &sess->close_work);
486	WARN_ON(sess->state != RTRS_SRV_CLOSING);
487}
488
489static inline const char *rtrs_srv_state_str(enum rtrs_srv_state state)
490{
491	switch (state) {
492	case RTRS_SRV_CONNECTING:
493		return "RTRS_SRV_CONNECTING";
494	case RTRS_SRV_CONNECTED:
495		return "RTRS_SRV_CONNECTED";
496	case RTRS_SRV_CLOSING:
497		return "RTRS_SRV_CLOSING";
498	case RTRS_SRV_CLOSED:
499		return "RTRS_SRV_CLOSED";
500	default:
501		return "UNKNOWN";
502	}
503}
504
505/**
506 * rtrs_srv_resp_rdma() - Finish an RDMA request
507 *
508 * @id:		Internal RTRS operation identifier
509 * @status:	Response Code sent to the other side for this operation.
510 *		0 = success, <=0 error
511 * Context: any
512 *
513 * Finish a RDMA operation. A message is sent to the client and the
514 * corresponding memory areas will be released.
515 */
516bool rtrs_srv_resp_rdma(struct rtrs_srv_op *id, int status)
517{
518	struct rtrs_srv_sess *sess;
519	struct rtrs_srv_con *con;
520	struct rtrs_sess *s;
521	int err;
522
523	if (WARN_ON(!id))
524		return true;
525
526	con = id->con;
527	s = con->c.sess;
528	sess = to_srv_sess(s);
529
530	id->status = status;
531
532	if (unlikely(sess->state != RTRS_SRV_CONNECTED)) {
533		rtrs_err_rl(s,
534			     "Sending I/O response failed,  session is disconnected, sess state %s\n",
535			     rtrs_srv_state_str(sess->state));
536		goto out;
537	}
538	if (always_invalidate) {
539		struct rtrs_srv_mr *mr = &sess->mrs[id->msg_id];
540
541		ib_update_fast_reg_key(mr->mr, ib_inc_rkey(mr->mr->rkey));
542	}
543	if (unlikely(atomic_sub_return(1,
544				       &con->sq_wr_avail) < 0)) {
545		pr_err("IB send queue full\n");
546		atomic_add(1, &con->sq_wr_avail);
547		spin_lock(&con->rsp_wr_wait_lock);
548		list_add_tail(&id->wait_list, &con->rsp_wr_wait_list);
549		spin_unlock(&con->rsp_wr_wait_lock);
550		return false;
551	}
552
553	if (status || id->dir == WRITE || !id->rd_msg->sg_cnt)
554		err = send_io_resp_imm(con, id, status);
555	else
556		err = rdma_write_sg(id);
557
558	if (unlikely(err)) {
559		rtrs_err_rl(s, "IO response failed: %d\n", err);
560		close_sess(sess);
561	}
562out:
563	rtrs_srv_put_ops_ids(sess);
564	return true;
565}
566EXPORT_SYMBOL(rtrs_srv_resp_rdma);
567
568/**
569 * rtrs_srv_set_sess_priv() - Set private pointer in rtrs_srv.
570 * @srv:	Session pointer
571 * @priv:	The private pointer that is associated with the session.
572 */
573void rtrs_srv_set_sess_priv(struct rtrs_srv *srv, void *priv)
574{
575	srv->priv = priv;
576}
577EXPORT_SYMBOL(rtrs_srv_set_sess_priv);
578
579static void unmap_cont_bufs(struct rtrs_srv_sess *sess)
580{
581	int i;
582
583	for (i = 0; i < sess->mrs_num; i++) {
584		struct rtrs_srv_mr *srv_mr;
585
586		srv_mr = &sess->mrs[i];
587		rtrs_iu_free(srv_mr->iu, sess->s.dev->ib_dev, 1);
588		ib_dereg_mr(srv_mr->mr);
589		ib_dma_unmap_sg(sess->s.dev->ib_dev, srv_mr->sgt.sgl,
590				srv_mr->sgt.nents, DMA_BIDIRECTIONAL);
591		sg_free_table(&srv_mr->sgt);
592	}
593	kfree(sess->mrs);
594}
595
596static int map_cont_bufs(struct rtrs_srv_sess *sess)
597{
598	struct rtrs_srv *srv = sess->srv;
599	struct rtrs_sess *ss = &sess->s;
600	int i, mri, err, mrs_num;
601	unsigned int chunk_bits;
602	int chunks_per_mr = 1;
603
604	/*
605	 * Here we map queue_depth chunks to MR.  Firstly we have to
606	 * figure out how many chunks can we map per MR.
607	 */
608	if (always_invalidate) {
609		/*
610		 * in order to do invalidate for each chunks of memory, we needs
611		 * more memory regions.
612		 */
613		mrs_num = srv->queue_depth;
614	} else {
615		chunks_per_mr =
616			sess->s.dev->ib_dev->attrs.max_fast_reg_page_list_len;
617		mrs_num = DIV_ROUND_UP(srv->queue_depth, chunks_per_mr);
618		chunks_per_mr = DIV_ROUND_UP(srv->queue_depth, mrs_num);
619	}
620
621	sess->mrs = kcalloc(mrs_num, sizeof(*sess->mrs), GFP_KERNEL);
622	if (!sess->mrs)
623		return -ENOMEM;
624
625	sess->mrs_num = mrs_num;
626
627	for (mri = 0; mri < mrs_num; mri++) {
628		struct rtrs_srv_mr *srv_mr = &sess->mrs[mri];
629		struct sg_table *sgt = &srv_mr->sgt;
630		struct scatterlist *s;
631		struct ib_mr *mr;
632		int nr, chunks;
633
634		chunks = chunks_per_mr * mri;
635		if (!always_invalidate)
636			chunks_per_mr = min_t(int, chunks_per_mr,
637					      srv->queue_depth - chunks);
638
639		err = sg_alloc_table(sgt, chunks_per_mr, GFP_KERNEL);
640		if (err)
641			goto err;
642
643		for_each_sg(sgt->sgl, s, chunks_per_mr, i)
644			sg_set_page(s, srv->chunks[chunks + i],
645				    max_chunk_size, 0);
646
647		nr = ib_dma_map_sg(sess->s.dev->ib_dev, sgt->sgl,
648				   sgt->nents, DMA_BIDIRECTIONAL);
649		if (nr < sgt->nents) {
650			err = nr < 0 ? nr : -EINVAL;
651			goto free_sg;
652		}
653		mr = ib_alloc_mr(sess->s.dev->ib_pd, IB_MR_TYPE_MEM_REG,
654				 sgt->nents);
655		if (IS_ERR(mr)) {
656			err = PTR_ERR(mr);
657			goto unmap_sg;
658		}
659		nr = ib_map_mr_sg(mr, sgt->sgl, sgt->nents,
660				  NULL, max_chunk_size);
661		if (nr < 0 || nr < sgt->nents) {
662			err = nr < 0 ? nr : -EINVAL;
663			goto dereg_mr;
664		}
665
666		if (always_invalidate) {
667			srv_mr->iu = rtrs_iu_alloc(1,
668					sizeof(struct rtrs_msg_rkey_rsp),
669					GFP_KERNEL, sess->s.dev->ib_dev,
670					DMA_TO_DEVICE, rtrs_srv_rdma_done);
671			if (!srv_mr->iu) {
672				err = -ENOMEM;
673				rtrs_err(ss, "rtrs_iu_alloc(), err: %d\n", err);
674				goto dereg_mr;
675			}
676		}
677		/* Eventually dma addr for each chunk can be cached */
678		for_each_sg(sgt->sgl, s, sgt->orig_nents, i)
679			sess->dma_addr[chunks + i] = sg_dma_address(s);
680
681		ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
682		srv_mr->mr = mr;
683
684		continue;
685err:
686		while (mri--) {
687			srv_mr = &sess->mrs[mri];
688			sgt = &srv_mr->sgt;
689			mr = srv_mr->mr;
690			rtrs_iu_free(srv_mr->iu, sess->s.dev->ib_dev, 1);
691dereg_mr:
692			ib_dereg_mr(mr);
693unmap_sg:
694			ib_dma_unmap_sg(sess->s.dev->ib_dev, sgt->sgl,
695					sgt->nents, DMA_BIDIRECTIONAL);
696free_sg:
697			sg_free_table(sgt);
698		}
699		kfree(sess->mrs);
700
701		return err;
702	}
703
704	chunk_bits = ilog2(srv->queue_depth - 1) + 1;
705	sess->mem_bits = (MAX_IMM_PAYL_BITS - chunk_bits);
706
707	return 0;
708}
709
710static void rtrs_srv_hb_err_handler(struct rtrs_con *c)
711{
712	close_sess(to_srv_sess(c->sess));
713}
714
715static void rtrs_srv_init_hb(struct rtrs_srv_sess *sess)
716{
717	rtrs_init_hb(&sess->s, &io_comp_cqe,
718		      RTRS_HB_INTERVAL_MS,
719		      RTRS_HB_MISSED_MAX,
720		      rtrs_srv_hb_err_handler,
721		      rtrs_wq);
722}
723
724static void rtrs_srv_start_hb(struct rtrs_srv_sess *sess)
725{
726	rtrs_start_hb(&sess->s);
727}
728
729static void rtrs_srv_stop_hb(struct rtrs_srv_sess *sess)
730{
731	rtrs_stop_hb(&sess->s);
732}
733
734static void rtrs_srv_info_rsp_done(struct ib_cq *cq, struct ib_wc *wc)
735{
736	struct rtrs_srv_con *con = cq->cq_context;
737	struct rtrs_sess *s = con->c.sess;
738	struct rtrs_srv_sess *sess = to_srv_sess(s);
739	struct rtrs_iu *iu;
740
741	iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
742	rtrs_iu_free(iu, sess->s.dev->ib_dev, 1);
743
744	if (unlikely(wc->status != IB_WC_SUCCESS)) {
745		rtrs_err(s, "Sess info response send failed: %s\n",
746			  ib_wc_status_msg(wc->status));
747		close_sess(sess);
748		return;
749	}
750	WARN_ON(wc->opcode != IB_WC_SEND);
751}
752
753static void rtrs_srv_sess_up(struct rtrs_srv_sess *sess)
754{
755	struct rtrs_srv *srv = sess->srv;
756	struct rtrs_srv_ctx *ctx = srv->ctx;
757	int up;
758
759	mutex_lock(&srv->paths_ev_mutex);
760	up = ++srv->paths_up;
761	if (up == 1)
762		ctx->ops.link_ev(srv, RTRS_SRV_LINK_EV_CONNECTED, NULL);
763	mutex_unlock(&srv->paths_ev_mutex);
764
765	/* Mark session as established */
766	sess->established = true;
767}
768
769static void rtrs_srv_sess_down(struct rtrs_srv_sess *sess)
770{
771	struct rtrs_srv *srv = sess->srv;
772	struct rtrs_srv_ctx *ctx = srv->ctx;
773
774	if (!sess->established)
775		return;
776
777	sess->established = false;
778	mutex_lock(&srv->paths_ev_mutex);
779	WARN_ON(!srv->paths_up);
780	if (--srv->paths_up == 0)
781		ctx->ops.link_ev(srv, RTRS_SRV_LINK_EV_DISCONNECTED, srv->priv);
782	mutex_unlock(&srv->paths_ev_mutex);
783}
784
785static int post_recv_sess(struct rtrs_srv_sess *sess);
786
787static int process_info_req(struct rtrs_srv_con *con,
788			    struct rtrs_msg_info_req *msg)
789{
790	struct rtrs_sess *s = con->c.sess;
791	struct rtrs_srv_sess *sess = to_srv_sess(s);
792	struct ib_send_wr *reg_wr = NULL;
793	struct rtrs_msg_info_rsp *rsp;
794	struct rtrs_iu *tx_iu;
795	struct ib_reg_wr *rwr;
796	int mri, err;
797	size_t tx_sz;
798
799	err = post_recv_sess(sess);
800	if (unlikely(err)) {
801		rtrs_err(s, "post_recv_sess(), err: %d\n", err);
802		return err;
803	}
804	rwr = kcalloc(sess->mrs_num, sizeof(*rwr), GFP_KERNEL);
805	if (unlikely(!rwr))
806		return -ENOMEM;
807	strlcpy(sess->s.sessname, msg->sessname, sizeof(sess->s.sessname));
808
809	tx_sz  = sizeof(*rsp);
810	tx_sz += sizeof(rsp->desc[0]) * sess->mrs_num;
811	tx_iu = rtrs_iu_alloc(1, tx_sz, GFP_KERNEL, sess->s.dev->ib_dev,
812			       DMA_TO_DEVICE, rtrs_srv_info_rsp_done);
813	if (unlikely(!tx_iu)) {
814		err = -ENOMEM;
815		goto rwr_free;
816	}
817
818	rsp = tx_iu->buf;
819	rsp->type = cpu_to_le16(RTRS_MSG_INFO_RSP);
820	rsp->sg_cnt = cpu_to_le16(sess->mrs_num);
821
822	for (mri = 0; mri < sess->mrs_num; mri++) {
823		struct ib_mr *mr = sess->mrs[mri].mr;
824
825		rsp->desc[mri].addr = cpu_to_le64(mr->iova);
826		rsp->desc[mri].key  = cpu_to_le32(mr->rkey);
827		rsp->desc[mri].len  = cpu_to_le32(mr->length);
828
829		/*
830		 * Fill in reg MR request and chain them *backwards*
831		 */
832		rwr[mri].wr.next = mri ? &rwr[mri - 1].wr : NULL;
833		rwr[mri].wr.opcode = IB_WR_REG_MR;
834		rwr[mri].wr.wr_cqe = &local_reg_cqe;
835		rwr[mri].wr.num_sge = 0;
836		rwr[mri].wr.send_flags = 0;
837		rwr[mri].mr = mr;
838		rwr[mri].key = mr->rkey;
839		rwr[mri].access = (IB_ACCESS_LOCAL_WRITE |
840				   IB_ACCESS_REMOTE_WRITE);
841		reg_wr = &rwr[mri].wr;
842	}
843
844	err = rtrs_srv_create_sess_files(sess);
845	if (unlikely(err))
846		goto iu_free;
847	kobject_get(&sess->kobj);
848	get_device(&sess->srv->dev);
849	rtrs_srv_change_state(sess, RTRS_SRV_CONNECTED);
850	rtrs_srv_start_hb(sess);
851
852	/*
853	 * We do not account number of established connections at the current
854	 * moment, we rely on the client, which should send info request when
855	 * all connections are successfully established.  Thus, simply notify
856	 * listener with a proper event if we are the first path.
857	 */
858	rtrs_srv_sess_up(sess);
859
860	ib_dma_sync_single_for_device(sess->s.dev->ib_dev, tx_iu->dma_addr,
861				      tx_iu->size, DMA_TO_DEVICE);
862
863	/* Send info response */
864	err = rtrs_iu_post_send(&con->c, tx_iu, tx_sz, reg_wr);
865	if (unlikely(err)) {
866		rtrs_err(s, "rtrs_iu_post_send(), err: %d\n", err);
867iu_free:
868		rtrs_iu_free(tx_iu, sess->s.dev->ib_dev, 1);
869	}
870rwr_free:
871	kfree(rwr);
872
873	return err;
874}
875
876static void rtrs_srv_info_req_done(struct ib_cq *cq, struct ib_wc *wc)
877{
878	struct rtrs_srv_con *con = cq->cq_context;
879	struct rtrs_sess *s = con->c.sess;
880	struct rtrs_srv_sess *sess = to_srv_sess(s);
881	struct rtrs_msg_info_req *msg;
882	struct rtrs_iu *iu;
883	int err;
884
885	WARN_ON(con->c.cid);
886
887	iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
888	if (unlikely(wc->status != IB_WC_SUCCESS)) {
889		rtrs_err(s, "Sess info request receive failed: %s\n",
890			  ib_wc_status_msg(wc->status));
891		goto close;
892	}
893	WARN_ON(wc->opcode != IB_WC_RECV);
894
895	if (unlikely(wc->byte_len < sizeof(*msg))) {
896		rtrs_err(s, "Sess info request is malformed: size %d\n",
897			  wc->byte_len);
898		goto close;
899	}
900	ib_dma_sync_single_for_cpu(sess->s.dev->ib_dev, iu->dma_addr,
901				   iu->size, DMA_FROM_DEVICE);
902	msg = iu->buf;
903	if (unlikely(le16_to_cpu(msg->type) != RTRS_MSG_INFO_REQ)) {
904		rtrs_err(s, "Sess info request is malformed: type %d\n",
905			  le16_to_cpu(msg->type));
906		goto close;
907	}
908	err = process_info_req(con, msg);
909	if (unlikely(err))
910		goto close;
911
912out:
913	rtrs_iu_free(iu, sess->s.dev->ib_dev, 1);
914	return;
915close:
916	close_sess(sess);
917	goto out;
918}
919
920static int post_recv_info_req(struct rtrs_srv_con *con)
921{
922	struct rtrs_sess *s = con->c.sess;
923	struct rtrs_srv_sess *sess = to_srv_sess(s);
924	struct rtrs_iu *rx_iu;
925	int err;
926
927	rx_iu = rtrs_iu_alloc(1, sizeof(struct rtrs_msg_info_req),
928			       GFP_KERNEL, sess->s.dev->ib_dev,
929			       DMA_FROM_DEVICE, rtrs_srv_info_req_done);
930	if (unlikely(!rx_iu))
931		return -ENOMEM;
932	/* Prepare for getting info response */
933	err = rtrs_iu_post_recv(&con->c, rx_iu);
934	if (unlikely(err)) {
935		rtrs_err(s, "rtrs_iu_post_recv(), err: %d\n", err);
936		rtrs_iu_free(rx_iu, sess->s.dev->ib_dev, 1);
937		return err;
938	}
939
940	return 0;
941}
942
943static int post_recv_io(struct rtrs_srv_con *con, size_t q_size)
944{
945	int i, err;
946
947	for (i = 0; i < q_size; i++) {
948		err = rtrs_post_recv_empty(&con->c, &io_comp_cqe);
949		if (unlikely(err))
950			return err;
951	}
952
953	return 0;
954}
955
956static int post_recv_sess(struct rtrs_srv_sess *sess)
957{
958	struct rtrs_srv *srv = sess->srv;
959	struct rtrs_sess *s = &sess->s;
960	size_t q_size;
961	int err, cid;
962
963	for (cid = 0; cid < sess->s.con_num; cid++) {
964		if (cid == 0)
965			q_size = SERVICE_CON_QUEUE_DEPTH;
966		else
967			q_size = srv->queue_depth;
968
969		err = post_recv_io(to_srv_con(sess->s.con[cid]), q_size);
970		if (unlikely(err)) {
971			rtrs_err(s, "post_recv_io(), err: %d\n", err);
972			return err;
973		}
974	}
975
976	return 0;
977}
978
979static void process_read(struct rtrs_srv_con *con,
980			 struct rtrs_msg_rdma_read *msg,
981			 u32 buf_id, u32 off)
982{
983	struct rtrs_sess *s = con->c.sess;
984	struct rtrs_srv_sess *sess = to_srv_sess(s);
985	struct rtrs_srv *srv = sess->srv;
986	struct rtrs_srv_ctx *ctx = srv->ctx;
987	struct rtrs_srv_op *id;
988
989	size_t usr_len, data_len;
990	void *data;
991	int ret;
992
993	if (unlikely(sess->state != RTRS_SRV_CONNECTED)) {
994		rtrs_err_rl(s,
995			     "Processing read request failed,  session is disconnected, sess state %s\n",
996			     rtrs_srv_state_str(sess->state));
997		return;
998	}
999	if (unlikely(msg->sg_cnt != 1 && msg->sg_cnt != 0)) {
1000		rtrs_err_rl(s,
1001			    "Processing read request failed, invalid message\n");
1002		return;
1003	}
1004	rtrs_srv_get_ops_ids(sess);
1005	rtrs_srv_update_rdma_stats(sess->stats, off, READ);
1006	id = sess->ops_ids[buf_id];
1007	id->con		= con;
1008	id->dir		= READ;
1009	id->msg_id	= buf_id;
1010	id->rd_msg	= msg;
1011	usr_len = le16_to_cpu(msg->usr_len);
1012	data_len = off - usr_len;
1013	data = page_address(srv->chunks[buf_id]);
1014	ret = ctx->ops.rdma_ev(srv, srv->priv, id, READ, data, data_len,
1015			   data + data_len, usr_len);
1016
1017	if (unlikely(ret)) {
1018		rtrs_err_rl(s,
1019			     "Processing read request failed, user module cb reported for msg_id %d, err: %d\n",
1020			     buf_id, ret);
1021		goto send_err_msg;
1022	}
1023
1024	return;
1025
1026send_err_msg:
1027	ret = send_io_resp_imm(con, id, ret);
1028	if (ret < 0) {
1029		rtrs_err_rl(s,
1030			     "Sending err msg for failed RDMA-Write-Req failed, msg_id %d, err: %d\n",
1031			     buf_id, ret);
1032		close_sess(sess);
1033	}
1034	rtrs_srv_put_ops_ids(sess);
1035}
1036
1037static void process_write(struct rtrs_srv_con *con,
1038			  struct rtrs_msg_rdma_write *req,
1039			  u32 buf_id, u32 off)
1040{
1041	struct rtrs_sess *s = con->c.sess;
1042	struct rtrs_srv_sess *sess = to_srv_sess(s);
1043	struct rtrs_srv *srv = sess->srv;
1044	struct rtrs_srv_ctx *ctx = srv->ctx;
1045	struct rtrs_srv_op *id;
1046
1047	size_t data_len, usr_len;
1048	void *data;
1049	int ret;
1050
1051	if (unlikely(sess->state != RTRS_SRV_CONNECTED)) {
1052		rtrs_err_rl(s,
1053			     "Processing write request failed,  session is disconnected, sess state %s\n",
1054			     rtrs_srv_state_str(sess->state));
1055		return;
1056	}
1057	rtrs_srv_get_ops_ids(sess);
1058	rtrs_srv_update_rdma_stats(sess->stats, off, WRITE);
1059	id = sess->ops_ids[buf_id];
1060	id->con    = con;
1061	id->dir    = WRITE;
1062	id->msg_id = buf_id;
1063
1064	usr_len = le16_to_cpu(req->usr_len);
1065	data_len = off - usr_len;
1066	data = page_address(srv->chunks[buf_id]);
1067	ret = ctx->ops.rdma_ev(srv, srv->priv, id, WRITE, data, data_len,
1068			   data + data_len, usr_len);
1069	if (unlikely(ret)) {
1070		rtrs_err_rl(s,
1071			     "Processing write request failed, user module callback reports err: %d\n",
1072			     ret);
1073		goto send_err_msg;
1074	}
1075
1076	return;
1077
1078send_err_msg:
1079	ret = send_io_resp_imm(con, id, ret);
1080	if (ret < 0) {
1081		rtrs_err_rl(s,
1082			     "Processing write request failed, sending I/O response failed, msg_id %d, err: %d\n",
1083			     buf_id, ret);
1084		close_sess(sess);
1085	}
1086	rtrs_srv_put_ops_ids(sess);
1087}
1088
1089static void process_io_req(struct rtrs_srv_con *con, void *msg,
1090			   u32 id, u32 off)
1091{
1092	struct rtrs_sess *s = con->c.sess;
1093	struct rtrs_srv_sess *sess = to_srv_sess(s);
1094	struct rtrs_msg_rdma_hdr *hdr;
1095	unsigned int type;
1096
1097	ib_dma_sync_single_for_cpu(sess->s.dev->ib_dev, sess->dma_addr[id],
1098				   max_chunk_size, DMA_BIDIRECTIONAL);
1099	hdr = msg;
1100	type = le16_to_cpu(hdr->type);
1101
1102	switch (type) {
1103	case RTRS_MSG_WRITE:
1104		process_write(con, msg, id, off);
1105		break;
1106	case RTRS_MSG_READ:
1107		process_read(con, msg, id, off);
1108		break;
1109	default:
1110		rtrs_err(s,
1111			  "Processing I/O request failed, unknown message type received: 0x%02x\n",
1112			  type);
1113		goto err;
1114	}
1115
1116	return;
1117
1118err:
1119	close_sess(sess);
1120}
1121
1122static void rtrs_srv_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc)
1123{
1124	struct rtrs_srv_mr *mr =
1125		container_of(wc->wr_cqe, typeof(*mr), inv_cqe);
1126	struct rtrs_srv_con *con = cq->cq_context;
1127	struct rtrs_sess *s = con->c.sess;
1128	struct rtrs_srv_sess *sess = to_srv_sess(s);
1129	struct rtrs_srv *srv = sess->srv;
1130	u32 msg_id, off;
1131	void *data;
1132
1133	if (unlikely(wc->status != IB_WC_SUCCESS)) {
1134		rtrs_err(s, "Failed IB_WR_LOCAL_INV: %s\n",
1135			  ib_wc_status_msg(wc->status));
1136		close_sess(sess);
1137	}
1138	msg_id = mr->msg_id;
1139	off = mr->msg_off;
1140	data = page_address(srv->chunks[msg_id]) + off;
1141	process_io_req(con, data, msg_id, off);
1142}
1143
1144static int rtrs_srv_inv_rkey(struct rtrs_srv_con *con,
1145			      struct rtrs_srv_mr *mr)
1146{
1147	struct ib_send_wr wr = {
1148		.opcode		    = IB_WR_LOCAL_INV,
1149		.wr_cqe		    = &mr->inv_cqe,
1150		.send_flags	    = IB_SEND_SIGNALED,
1151		.ex.invalidate_rkey = mr->mr->rkey,
1152	};
1153	mr->inv_cqe.done = rtrs_srv_inv_rkey_done;
1154
1155	return ib_post_send(con->c.qp, &wr, NULL);
1156}
1157
1158static void rtrs_rdma_process_wr_wait_list(struct rtrs_srv_con *con)
1159{
1160	spin_lock(&con->rsp_wr_wait_lock);
1161	while (!list_empty(&con->rsp_wr_wait_list)) {
1162		struct rtrs_srv_op *id;
1163		int ret;
1164
1165		id = list_entry(con->rsp_wr_wait_list.next,
1166				struct rtrs_srv_op, wait_list);
1167		list_del(&id->wait_list);
1168
1169		spin_unlock(&con->rsp_wr_wait_lock);
1170		ret = rtrs_srv_resp_rdma(id, id->status);
1171		spin_lock(&con->rsp_wr_wait_lock);
1172
1173		if (!ret) {
1174			list_add(&id->wait_list, &con->rsp_wr_wait_list);
1175			break;
1176		}
1177	}
1178	spin_unlock(&con->rsp_wr_wait_lock);
1179}
1180
1181static void rtrs_srv_rdma_done(struct ib_cq *cq, struct ib_wc *wc)
1182{
1183	struct rtrs_srv_con *con = cq->cq_context;
1184	struct rtrs_sess *s = con->c.sess;
1185	struct rtrs_srv_sess *sess = to_srv_sess(s);
1186	struct rtrs_srv *srv = sess->srv;
1187	u32 imm_type, imm_payload;
1188	int err;
1189
1190	if (unlikely(wc->status != IB_WC_SUCCESS)) {
1191		if (wc->status != IB_WC_WR_FLUSH_ERR) {
1192			rtrs_err(s,
1193				  "%s (wr_cqe: %p, type: %d, vendor_err: 0x%x, len: %u)\n",
1194				  ib_wc_status_msg(wc->status), wc->wr_cqe,
1195				  wc->opcode, wc->vendor_err, wc->byte_len);
1196			close_sess(sess);
1197		}
1198		return;
1199	}
1200
1201	switch (wc->opcode) {
1202	case IB_WC_RECV_RDMA_WITH_IMM:
1203		/*
1204		 * post_recv() RDMA write completions of IO reqs (read/write)
1205		 * and hb
1206		 */
1207		if (WARN_ON(wc->wr_cqe != &io_comp_cqe))
1208			return;
1209		err = rtrs_post_recv_empty(&con->c, &io_comp_cqe);
1210		if (unlikely(err)) {
1211			rtrs_err(s, "rtrs_post_recv(), err: %d\n", err);
1212			close_sess(sess);
1213			break;
1214		}
1215		rtrs_from_imm(be32_to_cpu(wc->ex.imm_data),
1216			       &imm_type, &imm_payload);
1217		if (likely(imm_type == RTRS_IO_REQ_IMM)) {
1218			u32 msg_id, off;
1219			void *data;
1220
1221			msg_id = imm_payload >> sess->mem_bits;
1222			off = imm_payload & ((1 << sess->mem_bits) - 1);
1223			if (unlikely(msg_id >= srv->queue_depth ||
1224				     off >= max_chunk_size)) {
1225				rtrs_err(s, "Wrong msg_id %u, off %u\n",
1226					  msg_id, off);
1227				close_sess(sess);
1228				return;
1229			}
1230			if (always_invalidate) {
1231				struct rtrs_srv_mr *mr = &sess->mrs[msg_id];
1232
1233				mr->msg_off = off;
1234				mr->msg_id = msg_id;
1235				err = rtrs_srv_inv_rkey(con, mr);
1236				if (unlikely(err)) {
1237					rtrs_err(s, "rtrs_post_recv(), err: %d\n",
1238						  err);
1239					close_sess(sess);
1240					break;
1241				}
1242			} else {
1243				data = page_address(srv->chunks[msg_id]) + off;
1244				process_io_req(con, data, msg_id, off);
1245			}
1246		} else if (imm_type == RTRS_HB_MSG_IMM) {
1247			WARN_ON(con->c.cid);
1248			rtrs_send_hb_ack(&sess->s);
1249		} else if (imm_type == RTRS_HB_ACK_IMM) {
1250			WARN_ON(con->c.cid);
1251			sess->s.hb_missed_cnt = 0;
1252		} else {
1253			rtrs_wrn(s, "Unknown IMM type %u\n", imm_type);
1254		}
1255		break;
1256	case IB_WC_RDMA_WRITE:
1257	case IB_WC_SEND:
1258		/*
1259		 * post_send() RDMA write completions of IO reqs (read/write)
1260		 */
1261		atomic_add(srv->queue_depth, &con->sq_wr_avail);
1262
1263		if (unlikely(!list_empty_careful(&con->rsp_wr_wait_list)))
1264			rtrs_rdma_process_wr_wait_list(con);
1265
1266		break;
1267	default:
1268		rtrs_wrn(s, "Unexpected WC type: %d\n", wc->opcode);
1269		return;
1270	}
1271}
1272
1273/**
1274 * rtrs_srv_get_sess_name() - Get rtrs_srv peer hostname.
1275 * @srv:	Session
1276 * @sessname:	Sessname buffer
1277 * @len:	Length of sessname buffer
1278 */
1279int rtrs_srv_get_sess_name(struct rtrs_srv *srv, char *sessname, size_t len)
1280{
1281	struct rtrs_srv_sess *sess;
1282	int err = -ENOTCONN;
1283
1284	mutex_lock(&srv->paths_mutex);
1285	list_for_each_entry(sess, &srv->paths_list, s.entry) {
1286		if (sess->state != RTRS_SRV_CONNECTED)
1287			continue;
1288		strlcpy(sessname, sess->s.sessname,
1289		       min_t(size_t, sizeof(sess->s.sessname), len));
1290		err = 0;
1291		break;
1292	}
1293	mutex_unlock(&srv->paths_mutex);
1294
1295	return err;
1296}
1297EXPORT_SYMBOL(rtrs_srv_get_sess_name);
1298
1299/**
1300 * rtrs_srv_get_sess_qdepth() - Get rtrs_srv qdepth.
1301 * @srv:	Session
1302 */
1303int rtrs_srv_get_queue_depth(struct rtrs_srv *srv)
1304{
1305	return srv->queue_depth;
1306}
1307EXPORT_SYMBOL(rtrs_srv_get_queue_depth);
1308
1309static int find_next_bit_ring(struct rtrs_srv_sess *sess)
1310{
1311	struct ib_device *ib_dev = sess->s.dev->ib_dev;
1312	int v;
1313
1314	v = cpumask_next(sess->cur_cq_vector, &cq_affinity_mask);
1315	if (v >= nr_cpu_ids || v >= ib_dev->num_comp_vectors)
1316		v = cpumask_first(&cq_affinity_mask);
1317	return v;
1318}
1319
1320static int rtrs_srv_get_next_cq_vector(struct rtrs_srv_sess *sess)
1321{
1322	sess->cur_cq_vector = find_next_bit_ring(sess);
1323
1324	return sess->cur_cq_vector;
1325}
1326
1327static void rtrs_srv_dev_release(struct device *dev)
1328{
1329	struct rtrs_srv *srv = container_of(dev, struct rtrs_srv, dev);
1330
1331	kfree(srv);
1332}
1333
1334static void free_srv(struct rtrs_srv *srv)
1335{
1336	int i;
1337
1338	WARN_ON(refcount_read(&srv->refcount));
1339	for (i = 0; i < srv->queue_depth; i++)
1340		mempool_free(srv->chunks[i], chunk_pool);
1341	kfree(srv->chunks);
1342	mutex_destroy(&srv->paths_mutex);
1343	mutex_destroy(&srv->paths_ev_mutex);
1344	/* last put to release the srv structure */
1345	put_device(&srv->dev);
1346}
1347
1348static struct rtrs_srv *get_or_create_srv(struct rtrs_srv_ctx *ctx,
1349					  const uuid_t *paths_uuid,
1350					  bool first_conn)
1351{
1352	struct rtrs_srv *srv;
1353	int i;
1354
1355	mutex_lock(&ctx->srv_mutex);
1356	list_for_each_entry(srv, &ctx->srv_list, ctx_list) {
1357		if (uuid_equal(&srv->paths_uuid, paths_uuid) &&
1358		    refcount_inc_not_zero(&srv->refcount)) {
1359			mutex_unlock(&ctx->srv_mutex);
1360			return srv;
1361		}
1362	}
1363	mutex_unlock(&ctx->srv_mutex);
1364	/*
1365	 * If this request is not the first connection request from the
1366	 * client for this session then fail and return error.
1367	 */
1368	if (!first_conn)
1369		return ERR_PTR(-ENXIO);
1370
1371	/* need to allocate a new srv */
1372	srv = kzalloc(sizeof(*srv), GFP_KERNEL);
1373	if  (!srv)
1374		return ERR_PTR(-ENOMEM);
1375
1376	INIT_LIST_HEAD(&srv->paths_list);
1377	mutex_init(&srv->paths_mutex);
1378	mutex_init(&srv->paths_ev_mutex);
1379	uuid_copy(&srv->paths_uuid, paths_uuid);
1380	srv->queue_depth = sess_queue_depth;
1381	srv->ctx = ctx;
1382	device_initialize(&srv->dev);
1383	srv->dev.release = rtrs_srv_dev_release;
1384
1385	srv->chunks = kcalloc(srv->queue_depth, sizeof(*srv->chunks),
1386			      GFP_KERNEL);
1387	if (!srv->chunks)
1388		goto err_free_srv;
1389
1390	for (i = 0; i < srv->queue_depth; i++) {
1391		srv->chunks[i] = mempool_alloc(chunk_pool, GFP_KERNEL);
1392		if (!srv->chunks[i])
1393			goto err_free_chunks;
1394	}
1395	refcount_set(&srv->refcount, 1);
1396	mutex_lock(&ctx->srv_mutex);
1397	list_add(&srv->ctx_list, &ctx->srv_list);
1398	mutex_unlock(&ctx->srv_mutex);
1399
1400	return srv;
1401
1402err_free_chunks:
1403	while (i--)
1404		mempool_free(srv->chunks[i], chunk_pool);
1405	kfree(srv->chunks);
1406
1407err_free_srv:
1408	kfree(srv);
1409	return ERR_PTR(-ENOMEM);
1410}
1411
1412static void put_srv(struct rtrs_srv *srv)
1413{
1414	if (refcount_dec_and_test(&srv->refcount)) {
1415		struct rtrs_srv_ctx *ctx = srv->ctx;
1416
1417		WARN_ON(srv->dev.kobj.state_in_sysfs);
1418
1419		mutex_lock(&ctx->srv_mutex);
1420		list_del(&srv->ctx_list);
1421		mutex_unlock(&ctx->srv_mutex);
1422		free_srv(srv);
1423	}
1424}
1425
1426static void __add_path_to_srv(struct rtrs_srv *srv,
1427			      struct rtrs_srv_sess *sess)
1428{
1429	list_add_tail(&sess->s.entry, &srv->paths_list);
1430	srv->paths_num++;
1431	WARN_ON(srv->paths_num >= MAX_PATHS_NUM);
1432}
1433
1434static void del_path_from_srv(struct rtrs_srv_sess *sess)
1435{
1436	struct rtrs_srv *srv = sess->srv;
1437
1438	if (WARN_ON(!srv))
1439		return;
1440
1441	mutex_lock(&srv->paths_mutex);
1442	list_del(&sess->s.entry);
1443	WARN_ON(!srv->paths_num);
1444	srv->paths_num--;
1445	mutex_unlock(&srv->paths_mutex);
1446}
1447
1448/* return true if addresses are the same, error other wise */
1449static int sockaddr_cmp(const struct sockaddr *a, const struct sockaddr *b)
1450{
1451	switch (a->sa_family) {
1452	case AF_IB:
1453		return memcmp(&((struct sockaddr_ib *)a)->sib_addr,
1454			      &((struct sockaddr_ib *)b)->sib_addr,
1455			      sizeof(struct ib_addr)) &&
1456			(b->sa_family == AF_IB);
1457	case AF_INET:
1458		return memcmp(&((struct sockaddr_in *)a)->sin_addr,
1459			      &((struct sockaddr_in *)b)->sin_addr,
1460			      sizeof(struct in_addr)) &&
1461			(b->sa_family == AF_INET);
1462	case AF_INET6:
1463		return memcmp(&((struct sockaddr_in6 *)a)->sin6_addr,
1464			      &((struct sockaddr_in6 *)b)->sin6_addr,
1465			      sizeof(struct in6_addr)) &&
1466			(b->sa_family == AF_INET6);
1467	default:
1468		return -ENOENT;
1469	}
1470}
1471
1472static bool __is_path_w_addr_exists(struct rtrs_srv *srv,
1473				    struct rdma_addr *addr)
1474{
1475	struct rtrs_srv_sess *sess;
1476
1477	list_for_each_entry(sess, &srv->paths_list, s.entry)
1478		if (!sockaddr_cmp((struct sockaddr *)&sess->s.dst_addr,
1479				  (struct sockaddr *)&addr->dst_addr) &&
1480		    !sockaddr_cmp((struct sockaddr *)&sess->s.src_addr,
1481				  (struct sockaddr *)&addr->src_addr))
1482			return true;
1483
1484	return false;
1485}
1486
1487static void free_sess(struct rtrs_srv_sess *sess)
1488{
1489	if (sess->kobj.state_in_sysfs) {
1490		kobject_del(&sess->kobj);
1491		kobject_put(&sess->kobj);
1492	} else {
1493		kfree(sess->stats);
1494		kfree(sess);
1495	}
1496}
1497
1498static void rtrs_srv_close_work(struct work_struct *work)
1499{
1500	struct rtrs_srv_sess *sess;
1501	struct rtrs_srv_con *con;
1502	int i;
1503
1504	sess = container_of(work, typeof(*sess), close_work);
1505
1506	rtrs_srv_destroy_sess_files(sess);
1507	rtrs_srv_stop_hb(sess);
1508
1509	for (i = 0; i < sess->s.con_num; i++) {
1510		if (!sess->s.con[i])
1511			continue;
1512		con = to_srv_con(sess->s.con[i]);
1513		rdma_disconnect(con->c.cm_id);
1514		ib_drain_qp(con->c.qp);
1515	}
1516	/* Wait for all inflights */
1517	rtrs_srv_wait_ops_ids(sess);
1518
1519	/* Notify upper layer if we are the last path */
1520	rtrs_srv_sess_down(sess);
1521
1522	unmap_cont_bufs(sess);
1523	rtrs_srv_free_ops_ids(sess);
1524
1525	for (i = 0; i < sess->s.con_num; i++) {
1526		if (!sess->s.con[i])
1527			continue;
1528		con = to_srv_con(sess->s.con[i]);
1529		rtrs_cq_qp_destroy(&con->c);
1530		rdma_destroy_id(con->c.cm_id);
1531		kfree(con);
1532	}
1533	rtrs_ib_dev_put(sess->s.dev);
1534
1535	del_path_from_srv(sess);
1536	put_srv(sess->srv);
1537	sess->srv = NULL;
1538	rtrs_srv_change_state(sess, RTRS_SRV_CLOSED);
1539
1540	kfree(sess->dma_addr);
1541	kfree(sess->s.con);
1542	free_sess(sess);
1543}
1544
1545static int rtrs_rdma_do_accept(struct rtrs_srv_sess *sess,
1546			       struct rdma_cm_id *cm_id)
1547{
1548	struct rtrs_srv *srv = sess->srv;
1549	struct rtrs_msg_conn_rsp msg;
1550	struct rdma_conn_param param;
1551	int err;
1552
1553	param = (struct rdma_conn_param) {
1554		.rnr_retry_count = 7,
1555		.private_data = &msg,
1556		.private_data_len = sizeof(msg),
1557	};
1558
1559	msg = (struct rtrs_msg_conn_rsp) {
1560		.magic = cpu_to_le16(RTRS_MAGIC),
1561		.version = cpu_to_le16(RTRS_PROTO_VER),
1562		.queue_depth = cpu_to_le16(srv->queue_depth),
1563		.max_io_size = cpu_to_le32(max_chunk_size - MAX_HDR_SIZE),
1564		.max_hdr_size = cpu_to_le32(MAX_HDR_SIZE),
1565	};
1566
1567	if (always_invalidate)
1568		msg.flags = cpu_to_le32(RTRS_MSG_NEW_RKEY_F);
1569
1570	err = rdma_accept(cm_id, &param);
1571	if (err)
1572		pr_err("rdma_accept(), err: %d\n", err);
1573
1574	return err;
1575}
1576
1577static int rtrs_rdma_do_reject(struct rdma_cm_id *cm_id, int errno)
1578{
1579	struct rtrs_msg_conn_rsp msg;
1580	int err;
1581
1582	msg = (struct rtrs_msg_conn_rsp) {
1583		.magic = cpu_to_le16(RTRS_MAGIC),
1584		.version = cpu_to_le16(RTRS_PROTO_VER),
1585		.errno = cpu_to_le16(errno),
1586	};
1587
1588	err = rdma_reject(cm_id, &msg, sizeof(msg), IB_CM_REJ_CONSUMER_DEFINED);
1589	if (err)
1590		pr_err("rdma_reject(), err: %d\n", err);
1591
1592	/* Bounce errno back */
1593	return errno;
1594}
1595
1596static struct rtrs_srv_sess *
1597__find_sess(struct rtrs_srv *srv, const uuid_t *sess_uuid)
1598{
1599	struct rtrs_srv_sess *sess;
1600
1601	list_for_each_entry(sess, &srv->paths_list, s.entry) {
1602		if (uuid_equal(&sess->s.uuid, sess_uuid))
1603			return sess;
1604	}
1605
1606	return NULL;
1607}
1608
1609static int create_con(struct rtrs_srv_sess *sess,
1610		      struct rdma_cm_id *cm_id,
1611		      unsigned int cid)
1612{
1613	struct rtrs_srv *srv = sess->srv;
1614	struct rtrs_sess *s = &sess->s;
1615	struct rtrs_srv_con *con;
1616
1617	u32 cq_size, max_send_wr, max_recv_wr, wr_limit;
1618	int err, cq_vector;
1619
1620	con = kzalloc(sizeof(*con), GFP_KERNEL);
1621	if (!con) {
1622		err = -ENOMEM;
1623		goto err;
1624	}
1625
1626	spin_lock_init(&con->rsp_wr_wait_lock);
1627	INIT_LIST_HEAD(&con->rsp_wr_wait_list);
1628	con->c.cm_id = cm_id;
1629	con->c.sess = &sess->s;
1630	con->c.cid = cid;
1631	atomic_set(&con->wr_cnt, 1);
1632
1633	if (con->c.cid == 0) {
1634		/*
1635		 * All receive and all send (each requiring invalidate)
1636		 * + 2 for drain and heartbeat
1637		 */
1638		max_send_wr = SERVICE_CON_QUEUE_DEPTH * 2 + 2;
1639		max_recv_wr = SERVICE_CON_QUEUE_DEPTH + 2;
1640		cq_size = max_send_wr + max_recv_wr;
1641	} else {
1642		/*
1643		 * In theory we might have queue_depth * 32
1644		 * outstanding requests if an unsafe global key is used
1645		 * and we have queue_depth read requests each consisting
1646		 * of 32 different addresses. div 3 for mlx5.
1647		 */
1648		wr_limit = sess->s.dev->ib_dev->attrs.max_qp_wr / 3;
1649		/* when always_invlaidate enalbed, we need linv+rinv+mr+imm */
1650		if (always_invalidate)
1651			max_send_wr =
1652				min_t(int, wr_limit,
1653				      srv->queue_depth * (1 + 4) + 1);
1654		else
1655			max_send_wr =
1656				min_t(int, wr_limit,
1657				      srv->queue_depth * (1 + 2) + 1);
1658
1659		max_recv_wr = srv->queue_depth + 1;
1660		/*
1661		 * If we have all receive requests posted and
1662		 * all write requests posted and each read request
1663		 * requires an invalidate request + drain
1664		 * and qp gets into error state.
1665		 */
1666		cq_size = max_send_wr + max_recv_wr;
1667	}
1668	atomic_set(&con->sq_wr_avail, max_send_wr);
1669	cq_vector = rtrs_srv_get_next_cq_vector(sess);
1670
1671	/* TODO: SOFTIRQ can be faster, but be careful with softirq context */
1672	err = rtrs_cq_qp_create(&sess->s, &con->c, 1, cq_vector, cq_size,
1673				 max_send_wr, max_recv_wr,
1674				 IB_POLL_WORKQUEUE);
1675	if (err) {
1676		rtrs_err(s, "rtrs_cq_qp_create(), err: %d\n", err);
1677		goto free_con;
1678	}
1679	if (con->c.cid == 0) {
1680		err = post_recv_info_req(con);
1681		if (err)
1682			goto free_cqqp;
1683	}
1684	WARN_ON(sess->s.con[cid]);
1685	sess->s.con[cid] = &con->c;
1686
1687	/*
1688	 * Change context from server to current connection.  The other
1689	 * way is to use cm_id->qp->qp_context, which does not work on OFED.
1690	 */
1691	cm_id->context = &con->c;
1692
1693	return 0;
1694
1695free_cqqp:
1696	rtrs_cq_qp_destroy(&con->c);
1697free_con:
1698	kfree(con);
1699
1700err:
1701	return err;
1702}
1703
1704static struct rtrs_srv_sess *__alloc_sess(struct rtrs_srv *srv,
1705					   struct rdma_cm_id *cm_id,
1706					   unsigned int con_num,
1707					   unsigned int recon_cnt,
1708					   const uuid_t *uuid)
1709{
1710	struct rtrs_srv_sess *sess;
1711	int err = -ENOMEM;
1712
1713	if (srv->paths_num >= MAX_PATHS_NUM) {
1714		err = -ECONNRESET;
1715		goto err;
1716	}
1717	if (__is_path_w_addr_exists(srv, &cm_id->route.addr)) {
1718		err = -EEXIST;
1719		pr_err("Path with same addr exists\n");
1720		goto err;
1721	}
1722	sess = kzalloc(sizeof(*sess), GFP_KERNEL);
1723	if (!sess)
1724		goto err;
1725
1726	sess->stats = kzalloc(sizeof(*sess->stats), GFP_KERNEL);
1727	if (!sess->stats)
1728		goto err_free_sess;
1729
1730	sess->stats->sess = sess;
1731
1732	sess->dma_addr = kcalloc(srv->queue_depth, sizeof(*sess->dma_addr),
1733				 GFP_KERNEL);
1734	if (!sess->dma_addr)
1735		goto err_free_stats;
1736
1737	sess->s.con = kcalloc(con_num, sizeof(*sess->s.con), GFP_KERNEL);
1738	if (!sess->s.con)
1739		goto err_free_dma_addr;
1740
1741	sess->state = RTRS_SRV_CONNECTING;
1742	sess->srv = srv;
1743	sess->cur_cq_vector = -1;
1744	sess->s.dst_addr = cm_id->route.addr.dst_addr;
1745	sess->s.src_addr = cm_id->route.addr.src_addr;
1746	sess->s.con_num = con_num;
1747	sess->s.recon_cnt = recon_cnt;
1748	uuid_copy(&sess->s.uuid, uuid);
1749	spin_lock_init(&sess->state_lock);
1750	INIT_WORK(&sess->close_work, rtrs_srv_close_work);
1751	rtrs_srv_init_hb(sess);
1752
1753	sess->s.dev = rtrs_ib_dev_find_or_add(cm_id->device, &dev_pd);
1754	if (!sess->s.dev) {
1755		err = -ENOMEM;
1756		goto err_free_con;
1757	}
1758	err = map_cont_bufs(sess);
1759	if (err)
1760		goto err_put_dev;
1761
1762	err = rtrs_srv_alloc_ops_ids(sess);
1763	if (err)
1764		goto err_unmap_bufs;
1765
1766	__add_path_to_srv(srv, sess);
1767
1768	return sess;
1769
1770err_unmap_bufs:
1771	unmap_cont_bufs(sess);
1772err_put_dev:
1773	rtrs_ib_dev_put(sess->s.dev);
1774err_free_con:
1775	kfree(sess->s.con);
1776err_free_dma_addr:
1777	kfree(sess->dma_addr);
1778err_free_stats:
1779	kfree(sess->stats);
1780err_free_sess:
1781	kfree(sess);
1782err:
1783	return ERR_PTR(err);
1784}
1785
1786static int rtrs_rdma_connect(struct rdma_cm_id *cm_id,
1787			      const struct rtrs_msg_conn_req *msg,
1788			      size_t len)
1789{
1790	struct rtrs_srv_ctx *ctx = cm_id->context;
1791	struct rtrs_srv_sess *sess;
1792	struct rtrs_srv *srv;
1793
1794	u16 version, con_num, cid;
1795	u16 recon_cnt;
1796	int err;
1797
1798	if (len < sizeof(*msg)) {
1799		pr_err("Invalid RTRS connection request\n");
1800		goto reject_w_econnreset;
1801	}
1802	if (le16_to_cpu(msg->magic) != RTRS_MAGIC) {
1803		pr_err("Invalid RTRS magic\n");
1804		goto reject_w_econnreset;
1805	}
1806	version = le16_to_cpu(msg->version);
1807	if (version >> 8 != RTRS_PROTO_VER_MAJOR) {
1808		pr_err("Unsupported major RTRS version: %d, expected %d\n",
1809		       version >> 8, RTRS_PROTO_VER_MAJOR);
1810		goto reject_w_econnreset;
1811	}
1812	con_num = le16_to_cpu(msg->cid_num);
1813	if (con_num > 4096) {
1814		/* Sanity check */
1815		pr_err("Too many connections requested: %d\n", con_num);
1816		goto reject_w_econnreset;
1817	}
1818	cid = le16_to_cpu(msg->cid);
1819	if (cid >= con_num) {
1820		/* Sanity check */
1821		pr_err("Incorrect cid: %d >= %d\n", cid, con_num);
1822		goto reject_w_econnreset;
1823	}
1824	recon_cnt = le16_to_cpu(msg->recon_cnt);
1825	srv = get_or_create_srv(ctx, &msg->paths_uuid, msg->first_conn);
1826	if (IS_ERR(srv)) {
1827		err = PTR_ERR(srv);
1828		goto reject_w_err;
1829	}
1830	mutex_lock(&srv->paths_mutex);
1831	sess = __find_sess(srv, &msg->sess_uuid);
1832	if (sess) {
1833		struct rtrs_sess *s = &sess->s;
1834
1835		/* Session already holds a reference */
1836		put_srv(srv);
1837
1838		if (sess->state != RTRS_SRV_CONNECTING) {
1839			rtrs_err(s, "Session in wrong state: %s\n",
1840				  rtrs_srv_state_str(sess->state));
1841			mutex_unlock(&srv->paths_mutex);
1842			goto reject_w_econnreset;
1843		}
1844		/*
1845		 * Sanity checks
1846		 */
1847		if (con_num != s->con_num || cid >= s->con_num) {
1848			rtrs_err(s, "Incorrect request: %d, %d\n",
1849				  cid, con_num);
1850			mutex_unlock(&srv->paths_mutex);
1851			goto reject_w_econnreset;
1852		}
1853		if (s->con[cid]) {
1854			rtrs_err(s, "Connection already exists: %d\n",
1855				  cid);
1856			mutex_unlock(&srv->paths_mutex);
1857			goto reject_w_econnreset;
1858		}
1859	} else {
1860		sess = __alloc_sess(srv, cm_id, con_num, recon_cnt,
1861				    &msg->sess_uuid);
1862		if (IS_ERR(sess)) {
1863			mutex_unlock(&srv->paths_mutex);
1864			put_srv(srv);
1865			err = PTR_ERR(sess);
1866			goto reject_w_err;
1867		}
1868	}
1869	err = create_con(sess, cm_id, cid);
1870	if (err) {
1871		(void)rtrs_rdma_do_reject(cm_id, err);
1872		/*
1873		 * Since session has other connections we follow normal way
1874		 * through workqueue, but still return an error to tell cma.c
1875		 * to call rdma_destroy_id() for current connection.
1876		 */
1877		goto close_and_return_err;
1878	}
1879	err = rtrs_rdma_do_accept(sess, cm_id);
1880	if (err) {
1881		(void)rtrs_rdma_do_reject(cm_id, err);
1882		/*
1883		 * Since current connection was successfully added to the
1884		 * session we follow normal way through workqueue to close the
1885		 * session, thus return 0 to tell cma.c we call
1886		 * rdma_destroy_id() ourselves.
1887		 */
1888		err = 0;
1889		goto close_and_return_err;
1890	}
1891	mutex_unlock(&srv->paths_mutex);
1892
1893	return 0;
1894
1895reject_w_err:
1896	return rtrs_rdma_do_reject(cm_id, err);
1897
1898reject_w_econnreset:
1899	return rtrs_rdma_do_reject(cm_id, -ECONNRESET);
1900
1901close_and_return_err:
1902	mutex_unlock(&srv->paths_mutex);
1903	close_sess(sess);
1904
1905	return err;
1906}
1907
1908static int rtrs_srv_rdma_cm_handler(struct rdma_cm_id *cm_id,
1909				     struct rdma_cm_event *ev)
1910{
1911	struct rtrs_srv_sess *sess = NULL;
1912	struct rtrs_sess *s = NULL;
1913
1914	if (ev->event != RDMA_CM_EVENT_CONNECT_REQUEST) {
1915		struct rtrs_con *c = cm_id->context;
1916
1917		s = c->sess;
1918		sess = to_srv_sess(s);
1919	}
1920
1921	switch (ev->event) {
1922	case RDMA_CM_EVENT_CONNECT_REQUEST:
1923		/*
1924		 * In case of error cma.c will destroy cm_id,
1925		 * see cma_process_remove()
1926		 */
1927		return rtrs_rdma_connect(cm_id, ev->param.conn.private_data,
1928					  ev->param.conn.private_data_len);
1929	case RDMA_CM_EVENT_ESTABLISHED:
1930		/* Nothing here */
1931		break;
1932	case RDMA_CM_EVENT_REJECTED:
1933	case RDMA_CM_EVENT_CONNECT_ERROR:
1934	case RDMA_CM_EVENT_UNREACHABLE:
1935		rtrs_err(s, "CM error (CM event: %s, err: %d)\n",
1936			  rdma_event_msg(ev->event), ev->status);
1937		close_sess(sess);
1938		break;
1939	case RDMA_CM_EVENT_DISCONNECTED:
1940	case RDMA_CM_EVENT_ADDR_CHANGE:
1941	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
1942		close_sess(sess);
1943		break;
1944	case RDMA_CM_EVENT_DEVICE_REMOVAL:
1945		close_sess(sess);
1946		break;
1947	default:
1948		pr_err("Ignoring unexpected CM event %s, err %d\n",
1949		       rdma_event_msg(ev->event), ev->status);
1950		break;
1951	}
1952
1953	return 0;
1954}
1955
1956static struct rdma_cm_id *rtrs_srv_cm_init(struct rtrs_srv_ctx *ctx,
1957					    struct sockaddr *addr,
1958					    enum rdma_ucm_port_space ps)
1959{
1960	struct rdma_cm_id *cm_id;
1961	int ret;
1962
1963	cm_id = rdma_create_id(&init_net, rtrs_srv_rdma_cm_handler,
1964			       ctx, ps, IB_QPT_RC);
1965	if (IS_ERR(cm_id)) {
1966		ret = PTR_ERR(cm_id);
1967		pr_err("Creating id for RDMA connection failed, err: %d\n",
1968		       ret);
1969		goto err_out;
1970	}
1971	ret = rdma_bind_addr(cm_id, addr);
1972	if (ret) {
1973		pr_err("Binding RDMA address failed, err: %d\n", ret);
1974		goto err_cm;
1975	}
1976	ret = rdma_listen(cm_id, 64);
1977	if (ret) {
1978		pr_err("Listening on RDMA connection failed, err: %d\n",
1979		       ret);
1980		goto err_cm;
1981	}
1982
1983	return cm_id;
1984
1985err_cm:
1986	rdma_destroy_id(cm_id);
1987err_out:
1988
1989	return ERR_PTR(ret);
1990}
1991
1992static int rtrs_srv_rdma_init(struct rtrs_srv_ctx *ctx, u16 port)
1993{
1994	struct sockaddr_in6 sin = {
1995		.sin6_family	= AF_INET6,
1996		.sin6_addr	= IN6ADDR_ANY_INIT,
1997		.sin6_port	= htons(port),
1998	};
1999	struct sockaddr_ib sib = {
2000		.sib_family			= AF_IB,
2001		.sib_sid	= cpu_to_be64(RDMA_IB_IP_PS_IB | port),
2002		.sib_sid_mask	= cpu_to_be64(0xffffffffffffffffULL),
2003		.sib_pkey	= cpu_to_be16(0xffff),
2004	};
2005	struct rdma_cm_id *cm_ip, *cm_ib;
2006	int ret;
2007
2008	/*
2009	 * We accept both IPoIB and IB connections, so we need to keep
2010	 * two cm id's, one for each socket type and port space.
2011	 * If the cm initialization of one of the id's fails, we abort
2012	 * everything.
2013	 */
2014	cm_ip = rtrs_srv_cm_init(ctx, (struct sockaddr *)&sin, RDMA_PS_TCP);
2015	if (IS_ERR(cm_ip))
2016		return PTR_ERR(cm_ip);
2017
2018	cm_ib = rtrs_srv_cm_init(ctx, (struct sockaddr *)&sib, RDMA_PS_IB);
2019	if (IS_ERR(cm_ib)) {
2020		ret = PTR_ERR(cm_ib);
2021		goto free_cm_ip;
2022	}
2023
2024	ctx->cm_id_ip = cm_ip;
2025	ctx->cm_id_ib = cm_ib;
2026
2027	return 0;
2028
2029free_cm_ip:
2030	rdma_destroy_id(cm_ip);
2031
2032	return ret;
2033}
2034
2035static struct rtrs_srv_ctx *alloc_srv_ctx(struct rtrs_srv_ops *ops)
2036{
2037	struct rtrs_srv_ctx *ctx;
2038
2039	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
2040	if (!ctx)
2041		return NULL;
2042
2043	ctx->ops = *ops;
2044	mutex_init(&ctx->srv_mutex);
2045	INIT_LIST_HEAD(&ctx->srv_list);
2046
2047	return ctx;
2048}
2049
2050static void free_srv_ctx(struct rtrs_srv_ctx *ctx)
2051{
2052	WARN_ON(!list_empty(&ctx->srv_list));
2053	mutex_destroy(&ctx->srv_mutex);
2054	kfree(ctx);
2055}
2056
2057static int rtrs_srv_add_one(struct ib_device *device)
2058{
2059	struct rtrs_srv_ctx *ctx;
2060	int ret = 0;
2061
2062	mutex_lock(&ib_ctx.ib_dev_mutex);
2063	if (ib_ctx.ib_dev_count)
2064		goto out;
2065
2066	/*
2067	 * Since our CM IDs are NOT bound to any ib device we will create them
2068	 * only once
2069	 */
2070	ctx = ib_ctx.srv_ctx;
2071	ret = rtrs_srv_rdma_init(ctx, ib_ctx.port);
2072	if (ret) {
2073		/*
2074		 * We errored out here.
2075		 * According to the ib code, if we encounter an error here then the
2076		 * error code is ignored, and no more calls to our ops are made.
2077		 */
2078		pr_err("Failed to initialize RDMA connection");
2079		goto err_out;
2080	}
2081
2082out:
2083	/*
2084	 * Keep a track on the number of ib devices added
2085	 */
2086	ib_ctx.ib_dev_count++;
2087
2088err_out:
2089	mutex_unlock(&ib_ctx.ib_dev_mutex);
2090	return ret;
2091}
2092
2093static void rtrs_srv_remove_one(struct ib_device *device, void *client_data)
2094{
2095	struct rtrs_srv_ctx *ctx;
2096
2097	mutex_lock(&ib_ctx.ib_dev_mutex);
2098	ib_ctx.ib_dev_count--;
2099
2100	if (ib_ctx.ib_dev_count)
2101		goto out;
2102
2103	/*
2104	 * Since our CM IDs are NOT bound to any ib device we will remove them
2105	 * only once, when the last device is removed
2106	 */
2107	ctx = ib_ctx.srv_ctx;
2108	rdma_destroy_id(ctx->cm_id_ip);
2109	rdma_destroy_id(ctx->cm_id_ib);
2110
2111out:
2112	mutex_unlock(&ib_ctx.ib_dev_mutex);
2113}
2114
2115static struct ib_client rtrs_srv_client = {
2116	.name	= "rtrs_server",
2117	.add	= rtrs_srv_add_one,
2118	.remove	= rtrs_srv_remove_one
2119};
2120
2121/**
2122 * rtrs_srv_open() - open RTRS server context
2123 * @ops:		callback functions
2124 * @port:               port to listen on
2125 *
2126 * Creates server context with specified callbacks.
2127 *
2128 * Return a valid pointer on success otherwise PTR_ERR.
2129 */
2130struct rtrs_srv_ctx *rtrs_srv_open(struct rtrs_srv_ops *ops, u16 port)
2131{
2132	struct rtrs_srv_ctx *ctx;
2133	int err;
2134
2135	ctx = alloc_srv_ctx(ops);
2136	if (!ctx)
2137		return ERR_PTR(-ENOMEM);
2138
2139	mutex_init(&ib_ctx.ib_dev_mutex);
2140	ib_ctx.srv_ctx = ctx;
2141	ib_ctx.port = port;
2142
2143	err = ib_register_client(&rtrs_srv_client);
2144	if (err) {
2145		free_srv_ctx(ctx);
2146		return ERR_PTR(err);
2147	}
2148
2149	return ctx;
2150}
2151EXPORT_SYMBOL(rtrs_srv_open);
2152
2153static void close_sessions(struct rtrs_srv *srv)
2154{
2155	struct rtrs_srv_sess *sess;
2156
2157	mutex_lock(&srv->paths_mutex);
2158	list_for_each_entry(sess, &srv->paths_list, s.entry)
2159		close_sess(sess);
2160	mutex_unlock(&srv->paths_mutex);
2161}
2162
2163static void close_ctx(struct rtrs_srv_ctx *ctx)
2164{
2165	struct rtrs_srv *srv;
2166
2167	mutex_lock(&ctx->srv_mutex);
2168	list_for_each_entry(srv, &ctx->srv_list, ctx_list)
2169		close_sessions(srv);
2170	mutex_unlock(&ctx->srv_mutex);
2171	flush_workqueue(rtrs_wq);
2172}
2173
2174/**
2175 * rtrs_srv_close() - close RTRS server context
2176 * @ctx: pointer to server context
2177 *
2178 * Closes RTRS server context with all client sessions.
2179 */
2180void rtrs_srv_close(struct rtrs_srv_ctx *ctx)
2181{
2182	ib_unregister_client(&rtrs_srv_client);
2183	mutex_destroy(&ib_ctx.ib_dev_mutex);
2184	close_ctx(ctx);
2185	free_srv_ctx(ctx);
2186}
2187EXPORT_SYMBOL(rtrs_srv_close);
2188
2189static int check_module_params(void)
2190{
2191	if (sess_queue_depth < 1 || sess_queue_depth > MAX_SESS_QUEUE_DEPTH) {
2192		pr_err("Invalid sess_queue_depth value %d, has to be >= %d, <= %d.\n",
2193		       sess_queue_depth, 1, MAX_SESS_QUEUE_DEPTH);
2194		return -EINVAL;
2195	}
2196	if (max_chunk_size < MIN_CHUNK_SIZE || !is_power_of_2(max_chunk_size)) {
2197		pr_err("Invalid max_chunk_size value %d, has to be >= %d and should be power of two.\n",
2198		       max_chunk_size, MIN_CHUNK_SIZE);
2199		return -EINVAL;
2200	}
2201
2202	/*
2203	 * Check if IB immediate data size is enough to hold the mem_id and the
2204	 * offset inside the memory chunk
2205	 */
2206	if ((ilog2(sess_queue_depth - 1) + 1) +
2207	    (ilog2(max_chunk_size - 1) + 1) > MAX_IMM_PAYL_BITS) {
2208		pr_err("RDMA immediate size (%db) not enough to encode %d buffers of size %dB. Reduce 'sess_queue_depth' or 'max_chunk_size' parameters.\n",
2209		       MAX_IMM_PAYL_BITS, sess_queue_depth, max_chunk_size);
2210		return -EINVAL;
2211	}
2212
2213	return 0;
2214}
2215
2216static int __init rtrs_server_init(void)
2217{
2218	int err;
2219
2220	pr_info("Loading module %s, proto %s: (max_chunk_size: %d (pure IO %ld, headers %ld) , sess_queue_depth: %d, always_invalidate: %d)\n",
2221		KBUILD_MODNAME, RTRS_PROTO_VER_STRING,
2222		max_chunk_size, max_chunk_size - MAX_HDR_SIZE, MAX_HDR_SIZE,
2223		sess_queue_depth, always_invalidate);
2224
2225	rtrs_rdma_dev_pd_init(0, &dev_pd);
2226
2227	err = check_module_params();
2228	if (err) {
2229		pr_err("Failed to load module, invalid module parameters, err: %d\n",
2230		       err);
2231		return err;
2232	}
2233	chunk_pool = mempool_create_page_pool(sess_queue_depth * CHUNK_POOL_SZ,
2234					      get_order(max_chunk_size));
2235	if (!chunk_pool)
2236		return -ENOMEM;
2237	rtrs_dev_class = class_create(THIS_MODULE, "rtrs-server");
2238	if (IS_ERR(rtrs_dev_class)) {
2239		err = PTR_ERR(rtrs_dev_class);
2240		goto out_chunk_pool;
2241	}
2242	rtrs_wq = alloc_workqueue("rtrs_server_wq", 0, 0);
2243	if (!rtrs_wq) {
2244		err = -ENOMEM;
2245		goto out_dev_class;
2246	}
2247
2248	return 0;
2249
2250out_dev_class:
2251	class_destroy(rtrs_dev_class);
2252out_chunk_pool:
2253	mempool_destroy(chunk_pool);
2254
2255	return err;
2256}
2257
2258static void __exit rtrs_server_exit(void)
2259{
2260	destroy_workqueue(rtrs_wq);
2261	class_destroy(rtrs_dev_class);
2262	mempool_destroy(chunk_pool);
2263	rtrs_rdma_dev_pd_deinit(&dev_pd);
2264}
2265
2266module_init(rtrs_server_init);
2267module_exit(rtrs_server_exit);
2268