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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Shared Memory Communications over RDMA (SMC-R) and RoCE
4 *
5 * IB infrastructure:
6 * Establish SMC-R as an Infiniband Client to be notified about added and
7 * removed IB devices of type RDMA.
8 * Determine device and port characteristics for these IB devices.
9 *
10 * Copyright IBM Corp. 2016
11 *
12 * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
13 */
14
15#include <linux/random.h>
16#include <linux/workqueue.h>
17#include <linux/scatterlist.h>
18#include <rdma/ib_verbs.h>
19
20#include "smc_pnet.h"
21#include "smc_ib.h"
22#include "smc_core.h"
23#include "smc_wr.h"
24#include "smc.h"
25
26#define SMC_MAX_CQE 32766 /* max. # of completion queue elements */
27
28#define SMC_QP_MIN_RNR_TIMER 5
29#define SMC_QP_TIMEOUT 15 /* 4096 * 2 ** timeout usec */
30#define SMC_QP_RETRY_CNT 7 /* 7: infinite */
31#define SMC_QP_RNR_RETRY 7 /* 7: infinite */
32
33struct smc_ib_devices smc_ib_devices = { /* smc-registered ib devices */
34 .lock = __SPIN_LOCK_UNLOCKED(smc_ib_devices.lock),
35 .list = LIST_HEAD_INIT(smc_ib_devices.list),
36};
37
38#define SMC_LOCAL_SYSTEMID_RESET "%%%%%%%"
39
40u8 local_systemid[SMC_SYSTEMID_LEN] = SMC_LOCAL_SYSTEMID_RESET; /* unique system
41 * identifier
42 */
43
44static int smc_ib_modify_qp_init(struct smc_link *lnk)
45{
46 struct ib_qp_attr qp_attr;
47
48 memset(&qp_attr, 0, sizeof(qp_attr));
49 qp_attr.qp_state = IB_QPS_INIT;
50 qp_attr.pkey_index = 0;
51 qp_attr.port_num = lnk->ibport;
52 qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE
53 | IB_ACCESS_REMOTE_WRITE;
54 return ib_modify_qp(lnk->roce_qp, &qp_attr,
55 IB_QP_STATE | IB_QP_PKEY_INDEX |
56 IB_QP_ACCESS_FLAGS | IB_QP_PORT);
57}
58
59static int smc_ib_modify_qp_rtr(struct smc_link *lnk)
60{
61 enum ib_qp_attr_mask qp_attr_mask =
62 IB_QP_STATE | IB_QP_AV | IB_QP_PATH_MTU | IB_QP_DEST_QPN |
63 IB_QP_RQ_PSN | IB_QP_MAX_DEST_RD_ATOMIC | IB_QP_MIN_RNR_TIMER;
64 struct ib_qp_attr qp_attr;
65
66 memset(&qp_attr, 0, sizeof(qp_attr));
67 qp_attr.qp_state = IB_QPS_RTR;
68 qp_attr.path_mtu = min(lnk->path_mtu, lnk->peer_mtu);
69 qp_attr.ah_attr.type = RDMA_AH_ATTR_TYPE_ROCE;
70 rdma_ah_set_port_num(&qp_attr.ah_attr, lnk->ibport);
71 rdma_ah_set_grh(&qp_attr.ah_attr, NULL, 0, 0, 1, 0);
72 rdma_ah_set_dgid_raw(&qp_attr.ah_attr, lnk->peer_gid);
73 memcpy(&qp_attr.ah_attr.roce.dmac, lnk->peer_mac,
74 sizeof(lnk->peer_mac));
75 qp_attr.dest_qp_num = lnk->peer_qpn;
76 qp_attr.rq_psn = lnk->peer_psn; /* starting receive packet seq # */
77 qp_attr.max_dest_rd_atomic = 1; /* max # of resources for incoming
78 * requests
79 */
80 qp_attr.min_rnr_timer = SMC_QP_MIN_RNR_TIMER;
81
82 return ib_modify_qp(lnk->roce_qp, &qp_attr, qp_attr_mask);
83}
84
85int smc_ib_modify_qp_rts(struct smc_link *lnk)
86{
87 struct ib_qp_attr qp_attr;
88
89 memset(&qp_attr, 0, sizeof(qp_attr));
90 qp_attr.qp_state = IB_QPS_RTS;
91 qp_attr.timeout = SMC_QP_TIMEOUT; /* local ack timeout */
92 qp_attr.retry_cnt = SMC_QP_RETRY_CNT; /* retry count */
93 qp_attr.rnr_retry = SMC_QP_RNR_RETRY; /* RNR retries, 7=infinite */
94 qp_attr.sq_psn = lnk->psn_initial; /* starting send packet seq # */
95 qp_attr.max_rd_atomic = 1; /* # of outstanding RDMA reads and
96 * atomic ops allowed
97 */
98 return ib_modify_qp(lnk->roce_qp, &qp_attr,
99 IB_QP_STATE | IB_QP_TIMEOUT | IB_QP_RETRY_CNT |
100 IB_QP_SQ_PSN | IB_QP_RNR_RETRY |
101 IB_QP_MAX_QP_RD_ATOMIC);
102}
103
104int smc_ib_modify_qp_reset(struct smc_link *lnk)
105{
106 struct ib_qp_attr qp_attr;
107
108 memset(&qp_attr, 0, sizeof(qp_attr));
109 qp_attr.qp_state = IB_QPS_RESET;
110 return ib_modify_qp(lnk->roce_qp, &qp_attr, IB_QP_STATE);
111}
112
113int smc_ib_ready_link(struct smc_link *lnk)
114{
115 struct smc_link_group *lgr =
116 container_of(lnk, struct smc_link_group, lnk[0]);
117 int rc = 0;
118
119 rc = smc_ib_modify_qp_init(lnk);
120 if (rc)
121 goto out;
122
123 rc = smc_ib_modify_qp_rtr(lnk);
124 if (rc)
125 goto out;
126 smc_wr_remember_qp_attr(lnk);
127 rc = ib_req_notify_cq(lnk->smcibdev->roce_cq_recv,
128 IB_CQ_SOLICITED_MASK);
129 if (rc)
130 goto out;
131 rc = smc_wr_rx_post_init(lnk);
132 if (rc)
133 goto out;
134 smc_wr_remember_qp_attr(lnk);
135
136 if (lgr->role == SMC_SERV) {
137 rc = smc_ib_modify_qp_rts(lnk);
138 if (rc)
139 goto out;
140 smc_wr_remember_qp_attr(lnk);
141 }
142out:
143 return rc;
144}
145
146static void smc_ib_port_terminate(struct smc_ib_device *smcibdev, u8 ibport)
147{
148 struct smc_link_group *lgr, *l;
149
150 list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
151 if (lgr->lnk[SMC_SINGLE_LINK].smcibdev == smcibdev &&
152 lgr->lnk[SMC_SINGLE_LINK].ibport == ibport)
153 smc_lgr_terminate(lgr);
154 }
155}
156
157/* process context wrapper for might_sleep smc_ib_remember_port_attr */
158static void smc_ib_port_event_work(struct work_struct *work)
159{
160 struct smc_ib_device *smcibdev = container_of(
161 work, struct smc_ib_device, port_event_work);
162 u8 port_idx;
163
164 for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) {
165 smc_ib_remember_port_attr(smcibdev, port_idx + 1);
166 clear_bit(port_idx, &smcibdev->port_event_mask);
167 if (!smc_ib_port_active(smcibdev, port_idx + 1))
168 smc_ib_port_terminate(smcibdev, port_idx + 1);
169 }
170}
171
172/* can be called in IRQ context */
173static void smc_ib_global_event_handler(struct ib_event_handler *handler,
174 struct ib_event *ibevent)
175{
176 struct smc_ib_device *smcibdev;
177 u8 port_idx;
178
179 smcibdev = container_of(handler, struct smc_ib_device, event_handler);
180
181 switch (ibevent->event) {
182 case IB_EVENT_PORT_ERR:
183 case IB_EVENT_DEVICE_FATAL:
184 case IB_EVENT_PORT_ACTIVE:
185 port_idx = ibevent->element.port_num - 1;
186 set_bit(port_idx, &smcibdev->port_event_mask);
187 schedule_work(&smcibdev->port_event_work);
188 break;
189 default:
190 break;
191 }
192}
193
194void smc_ib_dealloc_protection_domain(struct smc_link *lnk)
195{
196 if (lnk->roce_pd)
197 ib_dealloc_pd(lnk->roce_pd);
198 lnk->roce_pd = NULL;
199}
200
201int smc_ib_create_protection_domain(struct smc_link *lnk)
202{
203 int rc;
204
205 lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
206 rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
207 if (IS_ERR(lnk->roce_pd))
208 lnk->roce_pd = NULL;
209 return rc;
210}
211
212static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv)
213{
214 struct smc_ib_device *smcibdev =
215 (struct smc_ib_device *)ibevent->device;
216 u8 port_idx;
217
218 switch (ibevent->event) {
219 case IB_EVENT_DEVICE_FATAL:
220 case IB_EVENT_GID_CHANGE:
221 case IB_EVENT_PORT_ERR:
222 case IB_EVENT_QP_ACCESS_ERR:
223 port_idx = ibevent->element.port_num - 1;
224 set_bit(port_idx, &smcibdev->port_event_mask);
225 schedule_work(&smcibdev->port_event_work);
226 break;
227 default:
228 break;
229 }
230}
231
232void smc_ib_destroy_queue_pair(struct smc_link *lnk)
233{
234 if (lnk->roce_qp)
235 ib_destroy_qp(lnk->roce_qp);
236 lnk->roce_qp = NULL;
237}
238
239/* create a queue pair within the protection domain for a link */
240int smc_ib_create_queue_pair(struct smc_link *lnk)
241{
242 struct ib_qp_init_attr qp_attr = {
243 .event_handler = smc_ib_qp_event_handler,
244 .qp_context = lnk,
245 .send_cq = lnk->smcibdev->roce_cq_send,
246 .recv_cq = lnk->smcibdev->roce_cq_recv,
247 .srq = NULL,
248 .cap = {
249 /* include unsolicited rdma_writes as well,
250 * there are max. 2 RDMA_WRITE per 1 WR_SEND
251 */
252 .max_send_wr = SMC_WR_BUF_CNT * 3,
253 .max_recv_wr = SMC_WR_BUF_CNT * 3,
254 .max_send_sge = SMC_IB_MAX_SEND_SGE,
255 .max_recv_sge = 1,
256 },
257 .sq_sig_type = IB_SIGNAL_REQ_WR,
258 .qp_type = IB_QPT_RC,
259 };
260 int rc;
261
262 lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr);
263 rc = PTR_ERR_OR_ZERO(lnk->roce_qp);
264 if (IS_ERR(lnk->roce_qp))
265 lnk->roce_qp = NULL;
266 else
267 smc_wr_remember_qp_attr(lnk);
268 return rc;
269}
270
271void smc_ib_put_memory_region(struct ib_mr *mr)
272{
273 ib_dereg_mr(mr);
274}
275
276static int smc_ib_map_mr_sg(struct smc_buf_desc *buf_slot)
277{
278 unsigned int offset = 0;
279 int sg_num;
280
281 /* map the largest prefix of a dma mapped SG list */
282 sg_num = ib_map_mr_sg(buf_slot->mr_rx[SMC_SINGLE_LINK],
283 buf_slot->sgt[SMC_SINGLE_LINK].sgl,
284 buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
285 &offset, PAGE_SIZE);
286
287 return sg_num;
288}
289
290/* Allocate a memory region and map the dma mapped SG list of buf_slot */
291int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
292 struct smc_buf_desc *buf_slot)
293{
294 if (buf_slot->mr_rx[SMC_SINGLE_LINK])
295 return 0; /* already done */
296
297 buf_slot->mr_rx[SMC_SINGLE_LINK] =
298 ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, 1 << buf_slot->order);
299 if (IS_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK])) {
300 int rc;
301
302 rc = PTR_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK]);
303 buf_slot->mr_rx[SMC_SINGLE_LINK] = NULL;
304 return rc;
305 }
306
307 if (smc_ib_map_mr_sg(buf_slot) != 1)
308 return -EINVAL;
309
310 return 0;
311}
312
313/* synchronize buffer usage for cpu access */
314void smc_ib_sync_sg_for_cpu(struct smc_ib_device *smcibdev,
315 struct smc_buf_desc *buf_slot,
316 enum dma_data_direction data_direction)
317{
318 struct scatterlist *sg;
319 unsigned int i;
320
321 /* for now there is just one DMA address */
322 for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
323 buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
324 if (!sg_dma_len(sg))
325 break;
326 ib_dma_sync_single_for_cpu(smcibdev->ibdev,
327 sg_dma_address(sg),
328 sg_dma_len(sg),
329 data_direction);
330 }
331}
332
333/* synchronize buffer usage for device access */
334void smc_ib_sync_sg_for_device(struct smc_ib_device *smcibdev,
335 struct smc_buf_desc *buf_slot,
336 enum dma_data_direction data_direction)
337{
338 struct scatterlist *sg;
339 unsigned int i;
340
341 /* for now there is just one DMA address */
342 for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
343 buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
344 if (!sg_dma_len(sg))
345 break;
346 ib_dma_sync_single_for_device(smcibdev->ibdev,
347 sg_dma_address(sg),
348 sg_dma_len(sg),
349 data_direction);
350 }
351}
352
353/* Map a new TX or RX buffer SG-table to DMA */
354int smc_ib_buf_map_sg(struct smc_ib_device *smcibdev,
355 struct smc_buf_desc *buf_slot,
356 enum dma_data_direction data_direction)
357{
358 int mapped_nents;
359
360 mapped_nents = ib_dma_map_sg(smcibdev->ibdev,
361 buf_slot->sgt[SMC_SINGLE_LINK].sgl,
362 buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
363 data_direction);
364 if (!mapped_nents)
365 return -ENOMEM;
366
367 return mapped_nents;
368}
369
370void smc_ib_buf_unmap_sg(struct smc_ib_device *smcibdev,
371 struct smc_buf_desc *buf_slot,
372 enum dma_data_direction data_direction)
373{
374 if (!buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address)
375 return; /* already unmapped */
376
377 ib_dma_unmap_sg(smcibdev->ibdev,
378 buf_slot->sgt[SMC_SINGLE_LINK].sgl,
379 buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
380 data_direction);
381 buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address = 0;
382}
383
384static int smc_ib_fill_gid_and_mac(struct smc_ib_device *smcibdev, u8 ibport)
385{
386 struct ib_gid_attr gattr;
387 int rc;
388
389 rc = ib_query_gid(smcibdev->ibdev, ibport, 0,
390 &smcibdev->gid[ibport - 1], &gattr);
391 if (rc || !gattr.ndev)
392 return -ENODEV;
393
394 memcpy(smcibdev->mac[ibport - 1], gattr.ndev->dev_addr, ETH_ALEN);
395 dev_put(gattr.ndev);
396 return 0;
397}
398
399/* Create an identifier unique for this instance of SMC-R.
400 * The MAC-address of the first active registered IB device
401 * plus a random 2-byte number is used to create this identifier.
402 * This name is delivered to the peer during connection initialization.
403 */
404static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev,
405 u8 ibport)
406{
407 memcpy(&local_systemid[2], &smcibdev->mac[ibport - 1],
408 sizeof(smcibdev->mac[ibport - 1]));
409 get_random_bytes(&local_systemid[0], 2);
410}
411
412bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport)
413{
414 return smcibdev->pattr[ibport - 1].state == IB_PORT_ACTIVE;
415}
416
417int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport)
418{
419 int rc;
420
421 memset(&smcibdev->pattr[ibport - 1], 0,
422 sizeof(smcibdev->pattr[ibport - 1]));
423 rc = ib_query_port(smcibdev->ibdev, ibport,
424 &smcibdev->pattr[ibport - 1]);
425 if (rc)
426 goto out;
427 /* the SMC protocol requires specification of the RoCE MAC address */
428 rc = smc_ib_fill_gid_and_mac(smcibdev, ibport);
429 if (rc)
430 goto out;
431 if (!strncmp(local_systemid, SMC_LOCAL_SYSTEMID_RESET,
432 sizeof(local_systemid)) &&
433 smc_ib_port_active(smcibdev, ibport))
434 /* create unique system identifier */
435 smc_ib_define_local_systemid(smcibdev, ibport);
436out:
437 return rc;
438}
439
440long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
441{
442 struct ib_cq_init_attr cqattr = {
443 .cqe = SMC_MAX_CQE, .comp_vector = 0 };
444 int cqe_size_order, smc_order;
445 long rc;
446
447 /* the calculated number of cq entries fits to mlx5 cq allocation */
448 cqe_size_order = cache_line_size() == 128 ? 7 : 6;
449 smc_order = MAX_ORDER - cqe_size_order - 1;
450 if (SMC_MAX_CQE + 2 > (0x00000001 << smc_order) * PAGE_SIZE)
451 cqattr.cqe = (0x00000001 << smc_order) * PAGE_SIZE - 2;
452 smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev,
453 smc_wr_tx_cq_handler, NULL,
454 smcibdev, &cqattr);
455 rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send);
456 if (IS_ERR(smcibdev->roce_cq_send)) {
457 smcibdev->roce_cq_send = NULL;
458 return rc;
459 }
460 smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev,
461 smc_wr_rx_cq_handler, NULL,
462 smcibdev, &cqattr);
463 rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv);
464 if (IS_ERR(smcibdev->roce_cq_recv)) {
465 smcibdev->roce_cq_recv = NULL;
466 goto err;
467 }
468 INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
469 smc_ib_global_event_handler);
470 ib_register_event_handler(&smcibdev->event_handler);
471 smc_wr_add_dev(smcibdev);
472 smcibdev->initialized = 1;
473 return rc;
474
475err:
476 ib_destroy_cq(smcibdev->roce_cq_send);
477 return rc;
478}
479
480static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
481{
482 if (!smcibdev->initialized)
483 return;
484 smcibdev->initialized = 0;
485 smc_wr_remove_dev(smcibdev);
486 ib_unregister_event_handler(&smcibdev->event_handler);
487 ib_destroy_cq(smcibdev->roce_cq_recv);
488 ib_destroy_cq(smcibdev->roce_cq_send);
489}
490
491static struct ib_client smc_ib_client;
492
493/* callback function for ib_register_client() */
494static void smc_ib_add_dev(struct ib_device *ibdev)
495{
496 struct smc_ib_device *smcibdev;
497
498 if (ibdev->node_type != RDMA_NODE_IB_CA)
499 return;
500
501 smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL);
502 if (!smcibdev)
503 return;
504
505 smcibdev->ibdev = ibdev;
506 INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
507
508 spin_lock(&smc_ib_devices.lock);
509 list_add_tail(&smcibdev->list, &smc_ib_devices.list);
510 spin_unlock(&smc_ib_devices.lock);
511 ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
512}
513
514/* callback function for ib_register_client() */
515static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
516{
517 struct smc_ib_device *smcibdev;
518
519 smcibdev = ib_get_client_data(ibdev, &smc_ib_client);
520 ib_set_client_data(ibdev, &smc_ib_client, NULL);
521 spin_lock(&smc_ib_devices.lock);
522 list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
523 spin_unlock(&smc_ib_devices.lock);
524 smc_pnet_remove_by_ibdev(smcibdev);
525 smc_ib_cleanup_per_ibdev(smcibdev);
526 kfree(smcibdev);
527}
528
529static struct ib_client smc_ib_client = {
530 .name = "smc_ib",
531 .add = smc_ib_add_dev,
532 .remove = smc_ib_remove_dev,
533};
534
535int __init smc_ib_register_client(void)
536{
537 return ib_register_client(&smc_ib_client);
538}
539
540void smc_ib_unregister_client(void)
541{
542 ib_unregister_client(&smc_ib_client);
543}