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  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  Shared Memory Communications over RDMA (SMC-R) and RoCE
  4 *
  5 *  Basic Transport Functions exploiting Infiniband API
  6 *
  7 *  Copyright IBM Corp. 2016
  8 *
  9 *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
 10 */
 11
 12#include <linux/socket.h>
 13#include <linux/if_vlan.h>
 14#include <linux/random.h>
 15#include <linux/workqueue.h>
 16#include <net/tcp.h>
 17#include <net/sock.h>
 18#include <rdma/ib_verbs.h>
 19
 20#include "smc.h"
 21#include "smc_clc.h"
 22#include "smc_core.h"
 23#include "smc_ib.h"
 24#include "smc_wr.h"
 25#include "smc_llc.h"
 26#include "smc_cdc.h"
 27#include "smc_close.h"
 28
 29#define SMC_LGR_NUM_INCR		256
 30#define SMC_LGR_FREE_DELAY_SERV		(600 * HZ)
 31#define SMC_LGR_FREE_DELAY_CLNT		(SMC_LGR_FREE_DELAY_SERV + 10)
 32
 33static u32 smc_lgr_num;			/* unique link group number */
 34
 35static void smc_buf_free(struct smc_buf_desc *buf_desc, struct smc_link *lnk,
 36			 bool is_rmb);
 37
 38static void smc_lgr_schedule_free_work(struct smc_link_group *lgr)
 39{
 40	/* client link group creation always follows the server link group
 41	 * creation. For client use a somewhat higher removal delay time,
 42	 * otherwise there is a risk of out-of-sync link groups.
 43	 */
 44	mod_delayed_work(system_wq, &lgr->free_work,
 45			 lgr->role == SMC_CLNT ? SMC_LGR_FREE_DELAY_CLNT :
 46						 SMC_LGR_FREE_DELAY_SERV);
 47}
 48
 49/* Register connection's alert token in our lookup structure.
 50 * To use rbtrees we have to implement our own insert core.
 51 * Requires @conns_lock
 52 * @smc		connection to register
 53 * Returns 0 on success, != otherwise.
 54 */
 55static void smc_lgr_add_alert_token(struct smc_connection *conn)
 56{
 57	struct rb_node **link, *parent = NULL;
 58	u32 token = conn->alert_token_local;
 59
 60	link = &conn->lgr->conns_all.rb_node;
 61	while (*link) {
 62		struct smc_connection *cur = rb_entry(*link,
 63					struct smc_connection, alert_node);
 64
 65		parent = *link;
 66		if (cur->alert_token_local > token)
 67			link = &parent->rb_left;
 68		else
 69			link = &parent->rb_right;
 70	}
 71	/* Put the new node there */
 72	rb_link_node(&conn->alert_node, parent, link);
 73	rb_insert_color(&conn->alert_node, &conn->lgr->conns_all);
 74}
 75
 76/* Register connection in link group by assigning an alert token
 77 * registered in a search tree.
 78 * Requires @conns_lock
 79 * Note that '0' is a reserved value and not assigned.
 80 */
 81static void smc_lgr_register_conn(struct smc_connection *conn)
 82{
 83	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 84	static atomic_t nexttoken = ATOMIC_INIT(0);
 85
 86	/* find a new alert_token_local value not yet used by some connection
 87	 * in this link group
 88	 */
 89	sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */
 90	while (!conn->alert_token_local) {
 91		conn->alert_token_local = atomic_inc_return(&nexttoken);
 92		if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr))
 93			conn->alert_token_local = 0;
 94	}
 95	smc_lgr_add_alert_token(conn);
 96	conn->lgr->conns_num++;
 97}
 98
 99/* Unregister connection and reset the alert token of the given connection<
100 */
101static void __smc_lgr_unregister_conn(struct smc_connection *conn)
102{
103	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
104	struct smc_link_group *lgr = conn->lgr;
105
106	rb_erase(&conn->alert_node, &lgr->conns_all);
107	lgr->conns_num--;
108	conn->alert_token_local = 0;
109	conn->lgr = NULL;
110	sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
111}
112
113/* Unregister connection and trigger lgr freeing if applicable
114 */
115static void smc_lgr_unregister_conn(struct smc_connection *conn)
116{
117	struct smc_link_group *lgr = conn->lgr;
118	int reduced = 0;
119
120	write_lock_bh(&lgr->conns_lock);
121	if (conn->alert_token_local) {
122		reduced = 1;
123		__smc_lgr_unregister_conn(conn);
124	}
125	write_unlock_bh(&lgr->conns_lock);
126	if (!reduced || lgr->conns_num)
127		return;
128	smc_lgr_schedule_free_work(lgr);
129}
130
131static void smc_lgr_free_work(struct work_struct *work)
132{
133	struct smc_link_group *lgr = container_of(to_delayed_work(work),
134						  struct smc_link_group,
135						  free_work);
136	bool conns;
137
138	spin_lock_bh(&smc_lgr_list.lock);
139	if (list_empty(&lgr->list))
140		goto free;
141	read_lock_bh(&lgr->conns_lock);
142	conns = RB_EMPTY_ROOT(&lgr->conns_all);
143	read_unlock_bh(&lgr->conns_lock);
144	if (!conns) { /* number of lgr connections is no longer zero */
145		spin_unlock_bh(&smc_lgr_list.lock);
146		return;
147	}
148	list_del_init(&lgr->list); /* remove from smc_lgr_list */
149free:
150	spin_unlock_bh(&smc_lgr_list.lock);
151	if (!delayed_work_pending(&lgr->free_work))
152		smc_lgr_free(lgr);
153}
154
155/* create a new SMC link group */
156static int smc_lgr_create(struct smc_sock *smc,
157			  struct smc_ib_device *smcibdev, u8 ibport,
158			  char *peer_systemid, unsigned short vlan_id)
159{
160	struct smc_link_group *lgr;
161	struct smc_link *lnk;
162	u8 rndvec[3];
163	int rc = 0;
164	int i;
165
166	lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
167	if (!lgr) {
168		rc = -ENOMEM;
169		goto out;
170	}
171	lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
172	lgr->sync_err = false;
173	memcpy(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN);
174	lgr->vlan_id = vlan_id;
175	rwlock_init(&lgr->sndbufs_lock);
176	rwlock_init(&lgr->rmbs_lock);
177	for (i = 0; i < SMC_RMBE_SIZES; i++) {
178		INIT_LIST_HEAD(&lgr->sndbufs[i]);
179		INIT_LIST_HEAD(&lgr->rmbs[i]);
180	}
181	smc_lgr_num += SMC_LGR_NUM_INCR;
182	memcpy(&lgr->id, (u8 *)&smc_lgr_num, SMC_LGR_ID_SIZE);
183	INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
184	lgr->conns_all = RB_ROOT;
185
186	lnk = &lgr->lnk[SMC_SINGLE_LINK];
187	/* initialize link */
188	lnk->state = SMC_LNK_ACTIVATING;
189	lnk->link_id = SMC_SINGLE_LINK;
190	lnk->smcibdev = smcibdev;
191	lnk->ibport = ibport;
192	lnk->path_mtu = smcibdev->pattr[ibport - 1].active_mtu;
193	if (!smcibdev->initialized)
194		smc_ib_setup_per_ibdev(smcibdev);
195	get_random_bytes(rndvec, sizeof(rndvec));
196	lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) + (rndvec[2] << 16);
197	rc = smc_wr_alloc_link_mem(lnk);
198	if (rc)
199		goto free_lgr;
200	rc = smc_ib_create_protection_domain(lnk);
201	if (rc)
202		goto free_link_mem;
203	rc = smc_ib_create_queue_pair(lnk);
204	if (rc)
205		goto dealloc_pd;
206	rc = smc_wr_create_link(lnk);
207	if (rc)
208		goto destroy_qp;
209	init_completion(&lnk->llc_confirm);
210	init_completion(&lnk->llc_confirm_resp);
211	init_completion(&lnk->llc_add);
212	init_completion(&lnk->llc_add_resp);
213
214	smc->conn.lgr = lgr;
215	rwlock_init(&lgr->conns_lock);
216	spin_lock_bh(&smc_lgr_list.lock);
217	list_add(&lgr->list, &smc_lgr_list.list);
218	spin_unlock_bh(&smc_lgr_list.lock);
219	return 0;
220
221destroy_qp:
222	smc_ib_destroy_queue_pair(lnk);
223dealloc_pd:
224	smc_ib_dealloc_protection_domain(lnk);
225free_link_mem:
226	smc_wr_free_link_mem(lnk);
227free_lgr:
228	kfree(lgr);
229out:
230	return rc;
231}
232
233static void smc_buf_unuse(struct smc_connection *conn)
234{
235	if (conn->sndbuf_desc) {
236		conn->sndbuf_desc->used = 0;
237		conn->sndbuf_size = 0;
238	}
239	if (conn->rmb_desc) {
240		if (!conn->rmb_desc->regerr) {
241			conn->rmb_desc->reused = 1;
242			conn->rmb_desc->used = 0;
243			conn->rmbe_size = 0;
244		} else {
245			/* buf registration failed, reuse not possible */
246			struct smc_link_group *lgr = conn->lgr;
247			struct smc_link *lnk;
248
249			write_lock_bh(&lgr->rmbs_lock);
250			list_del(&conn->rmb_desc->list);
251			write_unlock_bh(&lgr->rmbs_lock);
252
253			lnk = &lgr->lnk[SMC_SINGLE_LINK];
254			smc_buf_free(conn->rmb_desc, lnk, true);
255		}
256	}
257}
258
259/* remove a finished connection from its link group */
260void smc_conn_free(struct smc_connection *conn)
261{
262	if (!conn->lgr)
263		return;
264	smc_cdc_tx_dismiss_slots(conn);
265	smc_lgr_unregister_conn(conn);
266	smc_buf_unuse(conn);
267}
268
269static void smc_link_clear(struct smc_link *lnk)
270{
271	lnk->peer_qpn = 0;
272	smc_ib_modify_qp_reset(lnk);
273	smc_wr_free_link(lnk);
274	smc_ib_destroy_queue_pair(lnk);
275	smc_ib_dealloc_protection_domain(lnk);
276	smc_wr_free_link_mem(lnk);
277}
278
279static void smc_buf_free(struct smc_buf_desc *buf_desc, struct smc_link *lnk,
280			 bool is_rmb)
281{
282	if (is_rmb) {
283		if (buf_desc->mr_rx[SMC_SINGLE_LINK])
284			smc_ib_put_memory_region(
285					buf_desc->mr_rx[SMC_SINGLE_LINK]);
286		smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,
287				    DMA_FROM_DEVICE);
288	} else {
289		smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,
290				    DMA_TO_DEVICE);
291	}
292	sg_free_table(&buf_desc->sgt[SMC_SINGLE_LINK]);
293	if (buf_desc->cpu_addr)
294		free_pages((unsigned long)buf_desc->cpu_addr, buf_desc->order);
295	kfree(buf_desc);
296}
297
298static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
299{
300	struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
301	struct smc_buf_desc *buf_desc, *bf_desc;
302	struct list_head *buf_list;
303	int i;
304
305	for (i = 0; i < SMC_RMBE_SIZES; i++) {
306		if (is_rmb)
307			buf_list = &lgr->rmbs[i];
308		else
309			buf_list = &lgr->sndbufs[i];
310		list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
311					 list) {
312			list_del(&buf_desc->list);
313			smc_buf_free(buf_desc, lnk, is_rmb);
314		}
315	}
316}
317
318static void smc_lgr_free_bufs(struct smc_link_group *lgr)
319{
320	/* free send buffers */
321	__smc_lgr_free_bufs(lgr, false);
322	/* free rmbs */
323	__smc_lgr_free_bufs(lgr, true);
324}
325
326/* remove a link group */
327void smc_lgr_free(struct smc_link_group *lgr)
328{
329	smc_lgr_free_bufs(lgr);
330	smc_link_clear(&lgr->lnk[SMC_SINGLE_LINK]);
331	kfree(lgr);
332}
333
334void smc_lgr_forget(struct smc_link_group *lgr)
335{
336	spin_lock_bh(&smc_lgr_list.lock);
337	/* do not use this link group for new connections */
338	if (!list_empty(&lgr->list))
339		list_del_init(&lgr->list);
340	spin_unlock_bh(&smc_lgr_list.lock);
341}
342
343/* terminate linkgroup abnormally */
344void smc_lgr_terminate(struct smc_link_group *lgr)
345{
346	struct smc_connection *conn;
347	struct smc_sock *smc;
348	struct rb_node *node;
349
350	smc_lgr_forget(lgr);
351
352	write_lock_bh(&lgr->conns_lock);
353	node = rb_first(&lgr->conns_all);
354	while (node) {
355		conn = rb_entry(node, struct smc_connection, alert_node);
356		smc = container_of(conn, struct smc_sock, conn);
357		sock_hold(&smc->sk); /* sock_put in close work */
358		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
359		__smc_lgr_unregister_conn(conn);
360		write_unlock_bh(&lgr->conns_lock);
361		if (!schedule_work(&conn->close_work))
362			sock_put(&smc->sk);
363		write_lock_bh(&lgr->conns_lock);
364		node = rb_first(&lgr->conns_all);
365	}
366	write_unlock_bh(&lgr->conns_lock);
367	wake_up(&lgr->lnk[SMC_SINGLE_LINK].wr_reg_wait);
368	smc_lgr_schedule_free_work(lgr);
369}
370
371/* Determine vlan of internal TCP socket.
372 * @vlan_id: address to store the determined vlan id into
373 */
374static int smc_vlan_by_tcpsk(struct socket *clcsock, unsigned short *vlan_id)
375{
376	struct dst_entry *dst = sk_dst_get(clcsock->sk);
377	int rc = 0;
378
379	*vlan_id = 0;
380	if (!dst) {
381		rc = -ENOTCONN;
382		goto out;
383	}
384	if (!dst->dev) {
385		rc = -ENODEV;
386		goto out_rel;
387	}
388
389	if (is_vlan_dev(dst->dev))
390		*vlan_id = vlan_dev_vlan_id(dst->dev);
391
392out_rel:
393	dst_release(dst);
394out:
395	return rc;
396}
397
398/* determine the link gid matching the vlan id of the link group */
399static int smc_link_determine_gid(struct smc_link_group *lgr)
400{
401	struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
402	struct ib_gid_attr gattr;
403	union ib_gid gid;
404	int i;
405
406	if (!lgr->vlan_id) {
407		lnk->gid = lnk->smcibdev->gid[lnk->ibport - 1];
408		return 0;
409	}
410
411	for (i = 0; i < lnk->smcibdev->pattr[lnk->ibport - 1].gid_tbl_len;
412	     i++) {
413		if (ib_query_gid(lnk->smcibdev->ibdev, lnk->ibport, i, &gid,
414				 &gattr))
415			continue;
416		if (gattr.ndev) {
417			if (is_vlan_dev(gattr.ndev) &&
418			    vlan_dev_vlan_id(gattr.ndev) == lgr->vlan_id) {
419				lnk->gid = gid;
420				dev_put(gattr.ndev);
421				return 0;
422			}
423			dev_put(gattr.ndev);
424		}
425	}
426	return -ENODEV;
427}
428
429/* create a new SMC connection (and a new link group if necessary) */
430int smc_conn_create(struct smc_sock *smc,
431		    struct smc_ib_device *smcibdev, u8 ibport,
432		    struct smc_clc_msg_local *lcl, int srv_first_contact)
433{
434	struct smc_connection *conn = &smc->conn;
435	struct smc_link_group *lgr;
436	unsigned short vlan_id;
437	enum smc_lgr_role role;
438	int local_contact = SMC_FIRST_CONTACT;
439	int rc = 0;
440
441	role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
442	rc = smc_vlan_by_tcpsk(smc->clcsock, &vlan_id);
443	if (rc)
444		return rc;
445
446	if ((role == SMC_CLNT) && srv_first_contact)
447		/* create new link group as well */
448		goto create;
449
450	/* determine if an existing link group can be reused */
451	spin_lock_bh(&smc_lgr_list.lock);
452	list_for_each_entry(lgr, &smc_lgr_list.list, list) {
453		write_lock_bh(&lgr->conns_lock);
454		if (!memcmp(lgr->peer_systemid, lcl->id_for_peer,
455			    SMC_SYSTEMID_LEN) &&
456		    !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_gid, &lcl->gid,
457			    SMC_GID_SIZE) &&
458		    !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_mac, lcl->mac,
459			    sizeof(lcl->mac)) &&
460		    !lgr->sync_err &&
461		    (lgr->role == role) &&
462		    (lgr->vlan_id == vlan_id) &&
463		    ((role == SMC_CLNT) ||
464		     (lgr->conns_num < SMC_RMBS_PER_LGR_MAX))) {
465			/* link group found */
466			local_contact = SMC_REUSE_CONTACT;
467			conn->lgr = lgr;
468			smc_lgr_register_conn(conn); /* add smc conn to lgr */
469			write_unlock_bh(&lgr->conns_lock);
470			break;
471		}
472		write_unlock_bh(&lgr->conns_lock);
473	}
474	spin_unlock_bh(&smc_lgr_list.lock);
475
476	if (role == SMC_CLNT && !srv_first_contact &&
477	    (local_contact == SMC_FIRST_CONTACT)) {
478		/* Server reuses a link group, but Client wants to start
479		 * a new one
480		 * send out_of_sync decline, reason synchr. error
481		 */
482		return -ENOLINK;
483	}
484
485create:
486	if (local_contact == SMC_FIRST_CONTACT) {
487		rc = smc_lgr_create(smc, smcibdev, ibport,
488				    lcl->id_for_peer, vlan_id);
489		if (rc)
490			goto out;
491		smc_lgr_register_conn(conn); /* add smc conn to lgr */
492		rc = smc_link_determine_gid(conn->lgr);
493	}
494	conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
495	conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
496#ifndef KERNEL_HAS_ATOMIC64
497	spin_lock_init(&conn->acurs_lock);
498#endif
499
500out:
501	return rc ? rc : local_contact;
502}
503
504/* try to reuse a sndbuf or rmb description slot for a certain
505 * buffer size; if not available, return NULL
506 */
507static inline
508struct smc_buf_desc *smc_buf_get_slot(struct smc_link_group *lgr,
509				      int compressed_bufsize,
510				      rwlock_t *lock,
511				      struct list_head *buf_list)
512{
513	struct smc_buf_desc *buf_slot;
514
515	read_lock_bh(lock);
516	list_for_each_entry(buf_slot, buf_list, list) {
517		if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
518			read_unlock_bh(lock);
519			return buf_slot;
520		}
521	}
522	read_unlock_bh(lock);
523	return NULL;
524}
525
526/* one of the conditions for announcing a receiver's current window size is
527 * that it "results in a minimum increase in the window size of 10% of the
528 * receive buffer space" [RFC7609]
529 */
530static inline int smc_rmb_wnd_update_limit(int rmbe_size)
531{
532	return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
533}
534
535static struct smc_buf_desc *smc_new_buf_create(struct smc_link_group *lgr,
536					       bool is_rmb, int bufsize)
537{
538	struct smc_buf_desc *buf_desc;
539	struct smc_link *lnk;
540	int rc;
541
542	/* try to alloc a new buffer */
543	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
544	if (!buf_desc)
545		return ERR_PTR(-ENOMEM);
546
547	buf_desc->cpu_addr =
548		(void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN |
549					 __GFP_NOMEMALLOC |
550					 __GFP_NORETRY | __GFP_ZERO,
551					 get_order(bufsize));
552	if (!buf_desc->cpu_addr) {
553		kfree(buf_desc);
554		return ERR_PTR(-EAGAIN);
555	}
556	buf_desc->order = get_order(bufsize);
557
558	/* build the sg table from the pages */
559	lnk = &lgr->lnk[SMC_SINGLE_LINK];
560	rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1,
561			    GFP_KERNEL);
562	if (rc) {
563		smc_buf_free(buf_desc, lnk, is_rmb);
564		return ERR_PTR(rc);
565	}
566	sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl,
567		   buf_desc->cpu_addr, bufsize);
568
569	/* map sg table to DMA address */
570	rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc,
571			       is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
572	/* SMC protocol depends on mapping to one DMA address only */
573	if (rc != 1)  {
574		smc_buf_free(buf_desc, lnk, is_rmb);
575		return ERR_PTR(-EAGAIN);
576	}
577
578	/* create a new memory region for the RMB */
579	if (is_rmb) {
580		rc = smc_ib_get_memory_region(lnk->roce_pd,
581					      IB_ACCESS_REMOTE_WRITE |
582					      IB_ACCESS_LOCAL_WRITE,
583					      buf_desc);
584		if (rc) {
585			smc_buf_free(buf_desc, lnk, is_rmb);
586			return ERR_PTR(rc);
587		}
588	}
589
590	return buf_desc;
591}
592
593static int __smc_buf_create(struct smc_sock *smc, bool is_rmb)
594{
595	struct smc_connection *conn = &smc->conn;
596	struct smc_link_group *lgr = conn->lgr;
597	struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
598	struct list_head *buf_list;
599	int bufsize, bufsize_short;
600	int sk_buf_size;
601	rwlock_t *lock;
602
603	if (is_rmb)
604		/* use socket recv buffer size (w/o overhead) as start value */
605		sk_buf_size = smc->sk.sk_rcvbuf / 2;
606	else
607		/* use socket send buffer size (w/o overhead) as start value */
608		sk_buf_size = smc->sk.sk_sndbuf / 2;
609
610	for (bufsize_short = smc_compress_bufsize(sk_buf_size);
611	     bufsize_short >= 0; bufsize_short--) {
612
613		if (is_rmb) {
614			lock = &lgr->rmbs_lock;
615			buf_list = &lgr->rmbs[bufsize_short];
616		} else {
617			lock = &lgr->sndbufs_lock;
618			buf_list = &lgr->sndbufs[bufsize_short];
619		}
620		bufsize = smc_uncompress_bufsize(bufsize_short);
621		if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC)
622			continue;
623
624		/* check for reusable slot in the link group */
625		buf_desc = smc_buf_get_slot(lgr, bufsize_short, lock, buf_list);
626		if (buf_desc) {
627			memset(buf_desc->cpu_addr, 0, bufsize);
628			break; /* found reusable slot */
629		}
630
631		buf_desc = smc_new_buf_create(lgr, is_rmb, bufsize);
632		if (PTR_ERR(buf_desc) == -ENOMEM)
633			break;
634		if (IS_ERR(buf_desc))
635			continue;
636
637		buf_desc->used = 1;
638		write_lock_bh(lock);
639		list_add(&buf_desc->list, buf_list);
640		write_unlock_bh(lock);
641		break; /* found */
642	}
643
644	if (IS_ERR(buf_desc))
645		return -ENOMEM;
646
647	if (is_rmb) {
648		conn->rmb_desc = buf_desc;
649		conn->rmbe_size = bufsize;
650		conn->rmbe_size_short = bufsize_short;
651		smc->sk.sk_rcvbuf = bufsize * 2;
652		atomic_set(&conn->bytes_to_rcv, 0);
653		conn->rmbe_update_limit = smc_rmb_wnd_update_limit(bufsize);
654	} else {
655		conn->sndbuf_desc = buf_desc;
656		conn->sndbuf_size = bufsize;
657		smc->sk.sk_sndbuf = bufsize * 2;
658		atomic_set(&conn->sndbuf_space, bufsize);
659	}
660	return 0;
661}
662
663void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn)
664{
665	struct smc_link_group *lgr = conn->lgr;
666
667	smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
668			       conn->sndbuf_desc, DMA_TO_DEVICE);
669}
670
671void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
672{
673	struct smc_link_group *lgr = conn->lgr;
674
675	smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
676				  conn->sndbuf_desc, DMA_TO_DEVICE);
677}
678
679void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
680{
681	struct smc_link_group *lgr = conn->lgr;
682
683	smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
684			       conn->rmb_desc, DMA_FROM_DEVICE);
685}
686
687void smc_rmb_sync_sg_for_device(struct smc_connection *conn)
688{
689	struct smc_link_group *lgr = conn->lgr;
690
691	smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
692				  conn->rmb_desc, DMA_FROM_DEVICE);
693}
694
695/* create the send and receive buffer for an SMC socket;
696 * receive buffers are called RMBs;
697 * (even though the SMC protocol allows more than one RMB-element per RMB,
698 * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
699 * extra RMB for every connection in a link group
700 */
701int smc_buf_create(struct smc_sock *smc)
702{
703	int rc;
704
705	/* create send buffer */
706	rc = __smc_buf_create(smc, false);
707	if (rc)
708		return rc;
709	/* create rmb */
710	rc = __smc_buf_create(smc, true);
711	if (rc)
712		smc_buf_free(smc->conn.sndbuf_desc,
713			     &smc->conn.lgr->lnk[SMC_SINGLE_LINK], false);
714	return rc;
715}
716
717static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
718{
719	int i;
720
721	for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
722		if (!test_and_set_bit(i, lgr->rtokens_used_mask))
723			return i;
724	}
725	return -ENOSPC;
726}
727
728/* add a new rtoken from peer */
729int smc_rtoken_add(struct smc_link_group *lgr, __be64 nw_vaddr, __be32 nw_rkey)
730{
731	u64 dma_addr = be64_to_cpu(nw_vaddr);
732	u32 rkey = ntohl(nw_rkey);
733	int i;
734
735	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
736		if ((lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey) &&
737		    (lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr == dma_addr) &&
738		    test_bit(i, lgr->rtokens_used_mask)) {
739			/* already in list */
740			return i;
741		}
742	}
743	i = smc_rmb_reserve_rtoken_idx(lgr);
744	if (i < 0)
745		return i;
746	lgr->rtokens[i][SMC_SINGLE_LINK].rkey = rkey;
747	lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = dma_addr;
748	return i;
749}
750
751/* delete an rtoken */
752int smc_rtoken_delete(struct smc_link_group *lgr, __be32 nw_rkey)
753{
754	u32 rkey = ntohl(nw_rkey);
755	int i;
756
757	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
758		if (lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey &&
759		    test_bit(i, lgr->rtokens_used_mask)) {
760			lgr->rtokens[i][SMC_SINGLE_LINK].rkey = 0;
761			lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = 0;
762
763			clear_bit(i, lgr->rtokens_used_mask);
764			return 0;
765		}
766	}
767	return -ENOENT;
768}
769
770/* save rkey and dma_addr received from peer during clc handshake */
771int smc_rmb_rtoken_handling(struct smc_connection *conn,
772			    struct smc_clc_msg_accept_confirm *clc)
773{
774	conn->rtoken_idx = smc_rtoken_add(conn->lgr, clc->rmb_dma_addr,
775					  clc->rmb_rkey);
776	if (conn->rtoken_idx < 0)
777		return conn->rtoken_idx;
778	return 0;
779}