1 // SPDX-License-Identifier: GPL-2.0
3 * Shared Memory Communications over RDMA (SMC-R) and RoCE
5 * Basic Transport Functions exploiting Infiniband API
7 * Copyright IBM Corp. 2016
9 * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
12 #include <linux/socket.h>
13 #include <linux/if_vlan.h>
14 #include <linux/random.h>
15 #include <linux/workqueue.h>
18 #include <rdma/ib_verbs.h>
27 #include "smc_close.h"
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)
33 static u32 smc_lgr_num
; /* unique link group number */
35 /* Register connection's alert token in our lookup structure.
36 * To use rbtrees we have to implement our own insert core.
37 * Requires @conns_lock
38 * @smc connection to register
39 * Returns 0 on success, != otherwise.
41 static void smc_lgr_add_alert_token(struct smc_connection
*conn
)
43 struct rb_node
**link
, *parent
= NULL
;
44 u32 token
= conn
->alert_token_local
;
46 link
= &conn
->lgr
->conns_all
.rb_node
;
48 struct smc_connection
*cur
= rb_entry(*link
,
49 struct smc_connection
, alert_node
);
52 if (cur
->alert_token_local
> token
)
53 link
= &parent
->rb_left
;
55 link
= &parent
->rb_right
;
57 /* Put the new node there */
58 rb_link_node(&conn
->alert_node
, parent
, link
);
59 rb_insert_color(&conn
->alert_node
, &conn
->lgr
->conns_all
);
62 /* Register connection in link group by assigning an alert token
63 * registered in a search tree.
64 * Requires @conns_lock
65 * Note that '0' is a reserved value and not assigned.
67 static void smc_lgr_register_conn(struct smc_connection
*conn
)
69 struct smc_sock
*smc
= container_of(conn
, struct smc_sock
, conn
);
70 static atomic_t nexttoken
= ATOMIC_INIT(0);
72 /* find a new alert_token_local value not yet used by some connection
75 sock_hold(&smc
->sk
); /* sock_put in smc_lgr_unregister_conn() */
76 while (!conn
->alert_token_local
) {
77 conn
->alert_token_local
= atomic_inc_return(&nexttoken
);
78 if (smc_lgr_find_conn(conn
->alert_token_local
, conn
->lgr
))
79 conn
->alert_token_local
= 0;
81 smc_lgr_add_alert_token(conn
);
82 conn
->lgr
->conns_num
++;
85 /* Unregister connection and reset the alert token of the given connection<
87 static void __smc_lgr_unregister_conn(struct smc_connection
*conn
)
89 struct smc_sock
*smc
= container_of(conn
, struct smc_sock
, conn
);
90 struct smc_link_group
*lgr
= conn
->lgr
;
92 rb_erase(&conn
->alert_node
, &lgr
->conns_all
);
94 conn
->alert_token_local
= 0;
96 sock_put(&smc
->sk
); /* sock_hold in smc_lgr_register_conn() */
99 /* Unregister connection and trigger lgr freeing if applicable
101 static void smc_lgr_unregister_conn(struct smc_connection
*conn
)
103 struct smc_link_group
*lgr
= conn
->lgr
;
106 write_lock_bh(&lgr
->conns_lock
);
107 if (conn
->alert_token_local
) {
109 __smc_lgr_unregister_conn(conn
);
111 write_unlock_bh(&lgr
->conns_lock
);
112 if (!reduced
|| lgr
->conns_num
)
114 /* client link group creation always follows the server link group
115 * creation. For client use a somewhat higher removal delay time,
116 * otherwise there is a risk of out-of-sync link groups.
118 mod_delayed_work(system_wq
, &lgr
->free_work
,
119 lgr
->role
== SMC_CLNT
? SMC_LGR_FREE_DELAY_CLNT
:
120 SMC_LGR_FREE_DELAY_SERV
);
123 static void smc_lgr_free_work(struct work_struct
*work
)
125 struct smc_link_group
*lgr
= container_of(to_delayed_work(work
),
126 struct smc_link_group
,
130 spin_lock_bh(&smc_lgr_list
.lock
);
131 read_lock_bh(&lgr
->conns_lock
);
132 conns
= RB_EMPTY_ROOT(&lgr
->conns_all
);
133 read_unlock_bh(&lgr
->conns_lock
);
134 if (!conns
) { /* number of lgr connections is no longer zero */
135 spin_unlock_bh(&smc_lgr_list
.lock
);
138 list_del_init(&lgr
->list
); /* remove from smc_lgr_list */
139 spin_unlock_bh(&smc_lgr_list
.lock
);
143 /* create a new SMC link group */
144 static int smc_lgr_create(struct smc_sock
*smc
, __be32 peer_in_addr
,
145 struct smc_ib_device
*smcibdev
, u8 ibport
,
146 char *peer_systemid
, unsigned short vlan_id
)
148 struct smc_link_group
*lgr
;
149 struct smc_link
*lnk
;
154 lgr
= kzalloc(sizeof(*lgr
), GFP_KERNEL
);
159 lgr
->role
= smc
->listen_smc
? SMC_SERV
: SMC_CLNT
;
160 lgr
->sync_err
= false;
161 lgr
->daddr
= peer_in_addr
;
162 memcpy(lgr
->peer_systemid
, peer_systemid
, SMC_SYSTEMID_LEN
);
163 lgr
->vlan_id
= vlan_id
;
164 rwlock_init(&lgr
->sndbufs_lock
);
165 rwlock_init(&lgr
->rmbs_lock
);
166 for (i
= 0; i
< SMC_RMBE_SIZES
; i
++) {
167 INIT_LIST_HEAD(&lgr
->sndbufs
[i
]);
168 INIT_LIST_HEAD(&lgr
->rmbs
[i
]);
170 smc_lgr_num
+= SMC_LGR_NUM_INCR
;
171 memcpy(&lgr
->id
, (u8
*)&smc_lgr_num
, SMC_LGR_ID_SIZE
);
172 INIT_DELAYED_WORK(&lgr
->free_work
, smc_lgr_free_work
);
173 lgr
->conns_all
= RB_ROOT
;
175 lnk
= &lgr
->lnk
[SMC_SINGLE_LINK
];
176 /* initialize link */
177 lnk
->smcibdev
= smcibdev
;
178 lnk
->ibport
= ibport
;
179 lnk
->path_mtu
= smcibdev
->pattr
[ibport
- 1].active_mtu
;
180 if (!smcibdev
->initialized
)
181 smc_ib_setup_per_ibdev(smcibdev
);
182 get_random_bytes(rndvec
, sizeof(rndvec
));
183 lnk
->psn_initial
= rndvec
[0] + (rndvec
[1] << 8) + (rndvec
[2] << 16);
184 rc
= smc_wr_alloc_link_mem(lnk
);
187 rc
= smc_ib_create_protection_domain(lnk
);
190 rc
= smc_ib_create_queue_pair(lnk
);
193 rc
= smc_wr_create_link(lnk
);
196 init_completion(&lnk
->llc_confirm
);
197 init_completion(&lnk
->llc_confirm_resp
);
200 rwlock_init(&lgr
->conns_lock
);
201 spin_lock_bh(&smc_lgr_list
.lock
);
202 list_add(&lgr
->list
, &smc_lgr_list
.list
);
203 spin_unlock_bh(&smc_lgr_list
.lock
);
207 smc_ib_destroy_queue_pair(lnk
);
209 smc_ib_dealloc_protection_domain(lnk
);
211 smc_wr_free_link_mem(lnk
);
218 static void smc_buf_unuse(struct smc_connection
*conn
)
220 if (conn
->sndbuf_desc
) {
221 conn
->sndbuf_desc
->used
= 0;
222 conn
->sndbuf_size
= 0;
224 if (conn
->rmb_desc
) {
225 conn
->rmb_desc
->reused
= true;
226 conn
->rmb_desc
->used
= 0;
231 /* remove a finished connection from its link group */
232 void smc_conn_free(struct smc_connection
*conn
)
234 struct smc_link_group
*lgr
= conn
->lgr
;
238 smc_cdc_tx_dismiss_slots(conn
);
239 smc_lgr_unregister_conn(conn
);
243 static void smc_link_clear(struct smc_link
*lnk
)
246 smc_ib_modify_qp_reset(lnk
);
247 smc_wr_free_link(lnk
);
248 smc_ib_destroy_queue_pair(lnk
);
249 smc_ib_dealloc_protection_domain(lnk
);
250 smc_wr_free_link_mem(lnk
);
253 static void smc_buf_free(struct smc_buf_desc
*buf_desc
, struct smc_link
*lnk
,
257 if (buf_desc
->mr_rx
[SMC_SINGLE_LINK
])
258 smc_ib_put_memory_region(
259 buf_desc
->mr_rx
[SMC_SINGLE_LINK
]);
260 smc_ib_buf_unmap_sg(lnk
->smcibdev
, buf_desc
,
263 smc_ib_buf_unmap_sg(lnk
->smcibdev
, buf_desc
,
266 sg_free_table(&buf_desc
->sgt
[SMC_SINGLE_LINK
]);
267 if (buf_desc
->cpu_addr
)
268 free_pages((unsigned long)buf_desc
->cpu_addr
, buf_desc
->order
);
272 static void __smc_lgr_free_bufs(struct smc_link_group
*lgr
, bool is_rmb
)
274 struct smc_link
*lnk
= &lgr
->lnk
[SMC_SINGLE_LINK
];
275 struct smc_buf_desc
*buf_desc
, *bf_desc
;
276 struct list_head
*buf_list
;
279 for (i
= 0; i
< SMC_RMBE_SIZES
; i
++) {
281 buf_list
= &lgr
->rmbs
[i
];
283 buf_list
= &lgr
->sndbufs
[i
];
284 list_for_each_entry_safe(buf_desc
, bf_desc
, buf_list
,
286 list_del(&buf_desc
->list
);
287 smc_buf_free(buf_desc
, lnk
, is_rmb
);
292 static void smc_lgr_free_bufs(struct smc_link_group
*lgr
)
294 /* free send buffers */
295 __smc_lgr_free_bufs(lgr
, false);
297 __smc_lgr_free_bufs(lgr
, true);
300 /* remove a link group */
301 void smc_lgr_free(struct smc_link_group
*lgr
)
303 smc_lgr_free_bufs(lgr
);
304 smc_link_clear(&lgr
->lnk
[SMC_SINGLE_LINK
]);
308 /* terminate linkgroup abnormally */
309 void smc_lgr_terminate(struct smc_link_group
*lgr
)
311 struct smc_connection
*conn
;
312 struct smc_sock
*smc
;
313 struct rb_node
*node
;
315 spin_lock_bh(&smc_lgr_list
.lock
);
316 if (list_empty(&lgr
->list
)) {
317 /* termination already triggered */
318 spin_unlock_bh(&smc_lgr_list
.lock
);
321 /* do not use this link group for new connections */
322 list_del_init(&lgr
->list
);
323 spin_unlock_bh(&smc_lgr_list
.lock
);
325 write_lock_bh(&lgr
->conns_lock
);
326 node
= rb_first(&lgr
->conns_all
);
328 conn
= rb_entry(node
, struct smc_connection
, alert_node
);
329 smc
= container_of(conn
, struct smc_sock
, conn
);
331 __smc_lgr_unregister_conn(conn
);
332 schedule_work(&conn
->close_work
);
334 node
= rb_first(&lgr
->conns_all
);
336 write_unlock_bh(&lgr
->conns_lock
);
339 /* Determine vlan of internal TCP socket.
340 * @vlan_id: address to store the determined vlan id into
342 static int smc_vlan_by_tcpsk(struct socket
*clcsock
, unsigned short *vlan_id
)
344 struct dst_entry
*dst
= sk_dst_get(clcsock
->sk
);
357 if (is_vlan_dev(dst
->dev
))
358 *vlan_id
= vlan_dev_vlan_id(dst
->dev
);
366 /* determine the link gid matching the vlan id of the link group */
367 static int smc_link_determine_gid(struct smc_link_group
*lgr
)
369 struct smc_link
*lnk
= &lgr
->lnk
[SMC_SINGLE_LINK
];
370 struct ib_gid_attr gattr
;
375 lnk
->gid
= lnk
->smcibdev
->gid
[lnk
->ibport
- 1];
379 for (i
= 0; i
< lnk
->smcibdev
->pattr
[lnk
->ibport
- 1].gid_tbl_len
;
381 if (ib_query_gid(lnk
->smcibdev
->ibdev
, lnk
->ibport
, i
, &gid
,
385 (vlan_dev_vlan_id(gattr
.ndev
) == lgr
->vlan_id
)) {
393 /* create a new SMC connection (and a new link group if necessary) */
394 int smc_conn_create(struct smc_sock
*smc
, __be32 peer_in_addr
,
395 struct smc_ib_device
*smcibdev
, u8 ibport
,
396 struct smc_clc_msg_local
*lcl
, int srv_first_contact
)
398 struct smc_connection
*conn
= &smc
->conn
;
399 struct smc_link_group
*lgr
;
400 unsigned short vlan_id
;
401 enum smc_lgr_role role
;
402 int local_contact
= SMC_FIRST_CONTACT
;
405 role
= smc
->listen_smc
? SMC_SERV
: SMC_CLNT
;
406 rc
= smc_vlan_by_tcpsk(smc
->clcsock
, &vlan_id
);
410 if ((role
== SMC_CLNT
) && srv_first_contact
)
411 /* create new link group as well */
414 /* determine if an existing link group can be reused */
415 spin_lock_bh(&smc_lgr_list
.lock
);
416 list_for_each_entry(lgr
, &smc_lgr_list
.list
, list
) {
417 write_lock_bh(&lgr
->conns_lock
);
418 if (!memcmp(lgr
->peer_systemid
, lcl
->id_for_peer
,
420 !memcmp(lgr
->lnk
[SMC_SINGLE_LINK
].peer_gid
, &lcl
->gid
,
422 !memcmp(lgr
->lnk
[SMC_SINGLE_LINK
].peer_mac
, lcl
->mac
,
425 (lgr
->role
== role
) &&
426 (lgr
->vlan_id
== vlan_id
) &&
427 ((role
== SMC_CLNT
) ||
428 (lgr
->conns_num
< SMC_RMBS_PER_LGR_MAX
))) {
429 /* link group found */
430 local_contact
= SMC_REUSE_CONTACT
;
432 smc_lgr_register_conn(conn
); /* add smc conn to lgr */
433 write_unlock_bh(&lgr
->conns_lock
);
436 write_unlock_bh(&lgr
->conns_lock
);
438 spin_unlock_bh(&smc_lgr_list
.lock
);
440 if (role
== SMC_CLNT
&& !srv_first_contact
&&
441 (local_contact
== SMC_FIRST_CONTACT
)) {
442 /* Server reuses a link group, but Client wants to start
444 * send out_of_sync decline, reason synchr. error
450 if (local_contact
== SMC_FIRST_CONTACT
) {
451 rc
= smc_lgr_create(smc
, peer_in_addr
, smcibdev
, ibport
,
452 lcl
->id_for_peer
, vlan_id
);
455 smc_lgr_register_conn(conn
); /* add smc conn to lgr */
456 rc
= smc_link_determine_gid(conn
->lgr
);
458 conn
->local_tx_ctrl
.common
.type
= SMC_CDC_MSG_TYPE
;
459 conn
->local_tx_ctrl
.len
= sizeof(struct smc_cdc_msg
);
460 #ifndef KERNEL_HAS_ATOMIC64
461 spin_lock_init(&conn
->acurs_lock
);
465 return rc
? rc
: local_contact
;
468 /* try to reuse a sndbuf or rmb description slot for a certain
469 * buffer size; if not available, return NULL
472 struct smc_buf_desc
*smc_buf_get_slot(struct smc_link_group
*lgr
,
473 int compressed_bufsize
,
475 struct list_head
*buf_list
)
477 struct smc_buf_desc
*buf_slot
;
480 list_for_each_entry(buf_slot
, buf_list
, list
) {
481 if (cmpxchg(&buf_slot
->used
, 0, 1) == 0) {
482 read_unlock_bh(lock
);
486 read_unlock_bh(lock
);
490 /* one of the conditions for announcing a receiver's current window size is
491 * that it "results in a minimum increase in the window size of 10% of the
492 * receive buffer space" [RFC7609]
494 static inline int smc_rmb_wnd_update_limit(int rmbe_size
)
496 return min_t(int, rmbe_size
/ 10, SOCK_MIN_SNDBUF
/ 2);
499 static struct smc_buf_desc
*smc_new_buf_create(struct smc_link_group
*lgr
,
500 bool is_rmb
, int bufsize
)
502 struct smc_buf_desc
*buf_desc
;
503 struct smc_link
*lnk
;
506 /* try to alloc a new buffer */
507 buf_desc
= kzalloc(sizeof(*buf_desc
), GFP_KERNEL
);
509 return ERR_PTR(-ENOMEM
);
512 (void *)__get_free_pages(GFP_KERNEL
| __GFP_NOWARN
|
514 __GFP_NORETRY
| __GFP_ZERO
,
516 if (!buf_desc
->cpu_addr
) {
518 return ERR_PTR(-EAGAIN
);
520 buf_desc
->order
= get_order(bufsize
);
522 /* build the sg table from the pages */
523 lnk
= &lgr
->lnk
[SMC_SINGLE_LINK
];
524 rc
= sg_alloc_table(&buf_desc
->sgt
[SMC_SINGLE_LINK
], 1,
527 smc_buf_free(buf_desc
, lnk
, is_rmb
);
530 sg_set_buf(buf_desc
->sgt
[SMC_SINGLE_LINK
].sgl
,
531 buf_desc
->cpu_addr
, bufsize
);
533 /* map sg table to DMA address */
534 rc
= smc_ib_buf_map_sg(lnk
->smcibdev
, buf_desc
,
535 is_rmb
? DMA_FROM_DEVICE
: DMA_TO_DEVICE
);
536 /* SMC protocol depends on mapping to one DMA address only */
538 smc_buf_free(buf_desc
, lnk
, is_rmb
);
539 return ERR_PTR(-EAGAIN
);
542 /* create a new memory region for the RMB */
544 rc
= smc_ib_get_memory_region(lnk
->roce_pd
,
545 IB_ACCESS_REMOTE_WRITE
|
546 IB_ACCESS_LOCAL_WRITE
,
549 smc_buf_free(buf_desc
, lnk
, is_rmb
);
557 static int __smc_buf_create(struct smc_sock
*smc
, bool is_rmb
)
559 struct smc_connection
*conn
= &smc
->conn
;
560 struct smc_link_group
*lgr
= conn
->lgr
;
561 struct smc_buf_desc
*buf_desc
= NULL
;
562 struct list_head
*buf_list
;
563 int bufsize
, bufsize_short
;
568 /* use socket recv buffer size (w/o overhead) as start value */
569 sk_buf_size
= smc
->sk
.sk_rcvbuf
/ 2;
571 /* use socket send buffer size (w/o overhead) as start value */
572 sk_buf_size
= smc
->sk
.sk_sndbuf
/ 2;
574 for (bufsize_short
= smc_compress_bufsize(smc
->sk
.sk_sndbuf
/ 2);
575 bufsize_short
>= 0; bufsize_short
--) {
578 lock
= &lgr
->rmbs_lock
;
579 buf_list
= &lgr
->rmbs
[bufsize_short
];
581 lock
= &lgr
->sndbufs_lock
;
582 buf_list
= &lgr
->sndbufs
[bufsize_short
];
584 bufsize
= smc_uncompress_bufsize(bufsize_short
);
585 if ((1 << get_order(bufsize
)) > SG_MAX_SINGLE_ALLOC
)
588 /* check for reusable slot in the link group */
589 buf_desc
= smc_buf_get_slot(lgr
, bufsize_short
, lock
, buf_list
);
591 memset(buf_desc
->cpu_addr
, 0, bufsize
);
592 break; /* found reusable slot */
595 buf_desc
= smc_new_buf_create(lgr
, is_rmb
, bufsize
);
596 if (PTR_ERR(buf_desc
) == -ENOMEM
)
598 if (IS_ERR(buf_desc
))
603 list_add(&buf_desc
->list
, buf_list
);
604 write_unlock_bh(lock
);
608 if (IS_ERR(buf_desc
))
612 conn
->rmb_desc
= buf_desc
;
613 conn
->rmbe_size
= bufsize
;
614 conn
->rmbe_size_short
= bufsize_short
;
615 smc
->sk
.sk_rcvbuf
= bufsize
* 2;
616 atomic_set(&conn
->bytes_to_rcv
, 0);
617 conn
->rmbe_update_limit
= smc_rmb_wnd_update_limit(bufsize
);
619 conn
->sndbuf_desc
= buf_desc
;
620 conn
->sndbuf_size
= bufsize
;
621 smc
->sk
.sk_sndbuf
= bufsize
* 2;
622 atomic_set(&conn
->sndbuf_space
, bufsize
);
627 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection
*conn
)
629 struct smc_link_group
*lgr
= conn
->lgr
;
631 smc_ib_sync_sg_for_cpu(lgr
->lnk
[SMC_SINGLE_LINK
].smcibdev
,
632 conn
->sndbuf_desc
, DMA_TO_DEVICE
);
635 void smc_sndbuf_sync_sg_for_device(struct smc_connection
*conn
)
637 struct smc_link_group
*lgr
= conn
->lgr
;
639 smc_ib_sync_sg_for_device(lgr
->lnk
[SMC_SINGLE_LINK
].smcibdev
,
640 conn
->sndbuf_desc
, DMA_TO_DEVICE
);
643 void smc_rmb_sync_sg_for_cpu(struct smc_connection
*conn
)
645 struct smc_link_group
*lgr
= conn
->lgr
;
647 smc_ib_sync_sg_for_cpu(lgr
->lnk
[SMC_SINGLE_LINK
].smcibdev
,
648 conn
->rmb_desc
, DMA_FROM_DEVICE
);
651 void smc_rmb_sync_sg_for_device(struct smc_connection
*conn
)
653 struct smc_link_group
*lgr
= conn
->lgr
;
655 smc_ib_sync_sg_for_device(lgr
->lnk
[SMC_SINGLE_LINK
].smcibdev
,
656 conn
->rmb_desc
, DMA_FROM_DEVICE
);
659 /* create the send and receive buffer for an SMC socket;
660 * receive buffers are called RMBs;
661 * (even though the SMC protocol allows more than one RMB-element per RMB,
662 * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
663 * extra RMB for every connection in a link group
665 int smc_buf_create(struct smc_sock
*smc
)
669 /* create send buffer */
670 rc
= __smc_buf_create(smc
, false);
674 rc
= __smc_buf_create(smc
, true);
676 smc_buf_free(smc
->conn
.sndbuf_desc
,
677 &smc
->conn
.lgr
->lnk
[SMC_SINGLE_LINK
], false);
681 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group
*lgr
)
685 for_each_clear_bit(i
, lgr
->rtokens_used_mask
, SMC_RMBS_PER_LGR_MAX
) {
686 if (!test_and_set_bit(i
, lgr
->rtokens_used_mask
))
692 /* save rkey and dma_addr received from peer during clc handshake */
693 int smc_rmb_rtoken_handling(struct smc_connection
*conn
,
694 struct smc_clc_msg_accept_confirm
*clc
)
696 u64 dma_addr
= be64_to_cpu(clc
->rmb_dma_addr
);
697 struct smc_link_group
*lgr
= conn
->lgr
;
698 u32 rkey
= ntohl(clc
->rmb_rkey
);
701 for (i
= 0; i
< SMC_RMBS_PER_LGR_MAX
; i
++) {
702 if ((lgr
->rtokens
[i
][SMC_SINGLE_LINK
].rkey
== rkey
) &&
703 (lgr
->rtokens
[i
][SMC_SINGLE_LINK
].dma_addr
== dma_addr
) &&
704 test_bit(i
, lgr
->rtokens_used_mask
)) {
705 conn
->rtoken_idx
= i
;
709 conn
->rtoken_idx
= smc_rmb_reserve_rtoken_idx(lgr
);
710 if (conn
->rtoken_idx
< 0)
711 return conn
->rtoken_idx
;
712 lgr
->rtokens
[conn
->rtoken_idx
][SMC_SINGLE_LINK
].rkey
= rkey
;
713 lgr
->rtokens
[conn
->rtoken_idx
][SMC_SINGLE_LINK
].dma_addr
= dma_addr
;