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