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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}