1 // SPDX-License-Identifier: GPL-2.0 2 /* Shared Memory Communications Direct over ISM devices (SMC-D) 3 * 4 * Functions for ISM device. 5 * 6 * Copyright IBM Corp. 2018 7 */ 8 9 #include <linux/spinlock.h> 10 #include <linux/mutex.h> 11 #include <linux/slab.h> 12 #include <asm/page.h> 13 14 #include "smc.h" 15 #include "smc_core.h" 16 #include "smc_ism.h" 17 #include "smc_pnet.h" 18 #include "smc_netlink.h" 19 20 struct smcd_dev_list smcd_dev_list = { 21 .list = LIST_HEAD_INIT(smcd_dev_list.list), 22 .mutex = __MUTEX_INITIALIZER(smcd_dev_list.mutex) 23 }; 24 25 static bool smc_ism_v2_capable; 26 27 /* Test if an ISM communication is possible - same CPC */ 28 int smc_ism_cantalk(u64 peer_gid, unsigned short vlan_id, struct smcd_dev *smcd) 29 { 30 return smcd->ops->query_remote_gid(smcd, peer_gid, vlan_id ? 1 : 0, 31 vlan_id); 32 } 33 34 int smc_ism_write(struct smcd_dev *smcd, const struct smc_ism_position *pos, 35 void *data, size_t len) 36 { 37 int rc; 38 39 rc = smcd->ops->move_data(smcd, pos->token, pos->index, pos->signal, 40 pos->offset, data, len); 41 42 return rc < 0 ? rc : 0; 43 } 44 45 void smc_ism_get_system_eid(struct smcd_dev *smcd, u8 **eid) 46 { 47 smcd->ops->get_system_eid(smcd, eid); 48 } 49 50 u16 smc_ism_get_chid(struct smcd_dev *smcd) 51 { 52 return smcd->ops->get_chid(smcd); 53 } 54 55 /* HW supports ISM V2 and thus System EID is defined */ 56 bool smc_ism_is_v2_capable(void) 57 { 58 return smc_ism_v2_capable; 59 } 60 61 /* Set a connection using this DMBE. */ 62 void smc_ism_set_conn(struct smc_connection *conn) 63 { 64 unsigned long flags; 65 66 spin_lock_irqsave(&conn->lgr->smcd->lock, flags); 67 conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = conn; 68 spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags); 69 } 70 71 /* Unset a connection using this DMBE. */ 72 void smc_ism_unset_conn(struct smc_connection *conn) 73 { 74 unsigned long flags; 75 76 if (!conn->rmb_desc) 77 return; 78 79 spin_lock_irqsave(&conn->lgr->smcd->lock, flags); 80 conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = NULL; 81 spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags); 82 } 83 84 /* Register a VLAN identifier with the ISM device. Use a reference count 85 * and add a VLAN identifier only when the first DMB using this VLAN is 86 * registered. 87 */ 88 int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid) 89 { 90 struct smc_ism_vlanid *new_vlan, *vlan; 91 unsigned long flags; 92 int rc = 0; 93 94 if (!vlanid) /* No valid vlan id */ 95 return -EINVAL; 96 97 /* create new vlan entry, in case we need it */ 98 new_vlan = kzalloc(sizeof(*new_vlan), GFP_KERNEL); 99 if (!new_vlan) 100 return -ENOMEM; 101 new_vlan->vlanid = vlanid; 102 refcount_set(&new_vlan->refcnt, 1); 103 104 /* if there is an existing entry, increase count and return */ 105 spin_lock_irqsave(&smcd->lock, flags); 106 list_for_each_entry(vlan, &smcd->vlan, list) { 107 if (vlan->vlanid == vlanid) { 108 refcount_inc(&vlan->refcnt); 109 kfree(new_vlan); 110 goto out; 111 } 112 } 113 114 /* no existing entry found. 115 * add new entry to device; might fail, e.g., if HW limit reached 116 */ 117 if (smcd->ops->add_vlan_id(smcd, vlanid)) { 118 kfree(new_vlan); 119 rc = -EIO; 120 goto out; 121 } 122 list_add_tail(&new_vlan->list, &smcd->vlan); 123 out: 124 spin_unlock_irqrestore(&smcd->lock, flags); 125 return rc; 126 } 127 128 /* Unregister a VLAN identifier with the ISM device. Use a reference count 129 * and remove a VLAN identifier only when the last DMB using this VLAN is 130 * unregistered. 131 */ 132 int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid) 133 { 134 struct smc_ism_vlanid *vlan; 135 unsigned long flags; 136 bool found = false; 137 int rc = 0; 138 139 if (!vlanid) /* No valid vlan id */ 140 return -EINVAL; 141 142 spin_lock_irqsave(&smcd->lock, flags); 143 list_for_each_entry(vlan, &smcd->vlan, list) { 144 if (vlan->vlanid == vlanid) { 145 if (!refcount_dec_and_test(&vlan->refcnt)) 146 goto out; 147 found = true; 148 break; 149 } 150 } 151 if (!found) { 152 rc = -ENOENT; 153 goto out; /* VLAN id not in table */ 154 } 155 156 /* Found and the last reference just gone */ 157 if (smcd->ops->del_vlan_id(smcd, vlanid)) 158 rc = -EIO; 159 list_del(&vlan->list); 160 kfree(vlan); 161 out: 162 spin_unlock_irqrestore(&smcd->lock, flags); 163 return rc; 164 } 165 166 int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc) 167 { 168 struct smcd_dmb dmb; 169 int rc = 0; 170 171 if (!dmb_desc->dma_addr) 172 return rc; 173 174 memset(&dmb, 0, sizeof(dmb)); 175 dmb.dmb_tok = dmb_desc->token; 176 dmb.sba_idx = dmb_desc->sba_idx; 177 dmb.cpu_addr = dmb_desc->cpu_addr; 178 dmb.dma_addr = dmb_desc->dma_addr; 179 dmb.dmb_len = dmb_desc->len; 180 rc = smcd->ops->unregister_dmb(smcd, &dmb); 181 if (!rc || rc == ISM_ERROR) { 182 dmb_desc->cpu_addr = NULL; 183 dmb_desc->dma_addr = 0; 184 } 185 186 return rc; 187 } 188 189 int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len, 190 struct smc_buf_desc *dmb_desc) 191 { 192 struct smcd_dmb dmb; 193 int rc; 194 195 memset(&dmb, 0, sizeof(dmb)); 196 dmb.dmb_len = dmb_len; 197 dmb.sba_idx = dmb_desc->sba_idx; 198 dmb.vlan_id = lgr->vlan_id; 199 dmb.rgid = lgr->peer_gid; 200 rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb); 201 if (!rc) { 202 dmb_desc->sba_idx = dmb.sba_idx; 203 dmb_desc->token = dmb.dmb_tok; 204 dmb_desc->cpu_addr = dmb.cpu_addr; 205 dmb_desc->dma_addr = dmb.dma_addr; 206 dmb_desc->len = dmb.dmb_len; 207 } 208 return rc; 209 } 210 211 static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd, 212 struct sk_buff *skb, 213 struct netlink_callback *cb) 214 { 215 char smc_pnet[SMC_MAX_PNETID_LEN + 1]; 216 struct smc_pci_dev smc_pci_dev; 217 struct nlattr *port_attrs; 218 struct nlattr *attrs; 219 int use_cnt = 0; 220 void *nlh; 221 222 nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, 223 &smc_gen_nl_family, NLM_F_MULTI, 224 SMC_NETLINK_GET_DEV_SMCD); 225 if (!nlh) 226 goto errmsg; 227 attrs = nla_nest_start(skb, SMC_GEN_DEV_SMCD); 228 if (!attrs) 229 goto errout; 230 use_cnt = atomic_read(&smcd->lgr_cnt); 231 if (nla_put_u32(skb, SMC_NLA_DEV_USE_CNT, use_cnt)) 232 goto errattr; 233 if (nla_put_u8(skb, SMC_NLA_DEV_IS_CRIT, use_cnt > 0)) 234 goto errattr; 235 memset(&smc_pci_dev, 0, sizeof(smc_pci_dev)); 236 smc_set_pci_values(to_pci_dev(smcd->dev.parent), &smc_pci_dev); 237 if (nla_put_u32(skb, SMC_NLA_DEV_PCI_FID, smc_pci_dev.pci_fid)) 238 goto errattr; 239 if (nla_put_u16(skb, SMC_NLA_DEV_PCI_CHID, smc_pci_dev.pci_pchid)) 240 goto errattr; 241 if (nla_put_u16(skb, SMC_NLA_DEV_PCI_VENDOR, smc_pci_dev.pci_vendor)) 242 goto errattr; 243 if (nla_put_u16(skb, SMC_NLA_DEV_PCI_DEVICE, smc_pci_dev.pci_device)) 244 goto errattr; 245 if (nla_put_string(skb, SMC_NLA_DEV_PCI_ID, smc_pci_dev.pci_id)) 246 goto errattr; 247 248 port_attrs = nla_nest_start(skb, SMC_NLA_DEV_PORT); 249 if (!port_attrs) 250 goto errattr; 251 if (nla_put_u8(skb, SMC_NLA_DEV_PORT_PNET_USR, smcd->pnetid_by_user)) 252 goto errportattr; 253 memcpy(smc_pnet, smcd->pnetid, SMC_MAX_PNETID_LEN); 254 smc_pnet[SMC_MAX_PNETID_LEN] = 0; 255 if (nla_put_string(skb, SMC_NLA_DEV_PORT_PNETID, smc_pnet)) 256 goto errportattr; 257 258 nla_nest_end(skb, port_attrs); 259 nla_nest_end(skb, attrs); 260 genlmsg_end(skb, nlh); 261 return 0; 262 263 errportattr: 264 nla_nest_cancel(skb, port_attrs); 265 errattr: 266 nla_nest_cancel(skb, attrs); 267 errout: 268 nlmsg_cancel(skb, nlh); 269 errmsg: 270 return -EMSGSIZE; 271 } 272 273 static void smc_nl_prep_smcd_dev(struct smcd_dev_list *dev_list, 274 struct sk_buff *skb, 275 struct netlink_callback *cb) 276 { 277 struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb); 278 int snum = cb_ctx->pos[0]; 279 struct smcd_dev *smcd; 280 int num = 0; 281 282 mutex_lock(&dev_list->mutex); 283 list_for_each_entry(smcd, &dev_list->list, list) { 284 if (num < snum) 285 goto next; 286 if (smc_nl_handle_smcd_dev(smcd, skb, cb)) 287 goto errout; 288 next: 289 num++; 290 } 291 errout: 292 mutex_unlock(&dev_list->mutex); 293 cb_ctx->pos[0] = num; 294 } 295 296 int smcd_nl_get_device(struct sk_buff *skb, struct netlink_callback *cb) 297 { 298 smc_nl_prep_smcd_dev(&smcd_dev_list, skb, cb); 299 return skb->len; 300 } 301 302 struct smc_ism_event_work { 303 struct work_struct work; 304 struct smcd_dev *smcd; 305 struct smcd_event event; 306 }; 307 308 #define ISM_EVENT_REQUEST 0x0001 309 #define ISM_EVENT_RESPONSE 0x0002 310 #define ISM_EVENT_REQUEST_IR 0x00000001 311 #define ISM_EVENT_CODE_SHUTDOWN 0x80 312 #define ISM_EVENT_CODE_TESTLINK 0x83 313 314 union smcd_sw_event_info { 315 u64 info; 316 struct { 317 u8 uid[SMC_LGR_ID_SIZE]; 318 unsigned short vlan_id; 319 u16 code; 320 }; 321 }; 322 323 static void smcd_handle_sw_event(struct smc_ism_event_work *wrk) 324 { 325 union smcd_sw_event_info ev_info; 326 327 ev_info.info = wrk->event.info; 328 switch (wrk->event.code) { 329 case ISM_EVENT_CODE_SHUTDOWN: /* Peer shut down DMBs */ 330 smc_smcd_terminate(wrk->smcd, wrk->event.tok, ev_info.vlan_id); 331 break; 332 case ISM_EVENT_CODE_TESTLINK: /* Activity timer */ 333 if (ev_info.code == ISM_EVENT_REQUEST) { 334 ev_info.code = ISM_EVENT_RESPONSE; 335 wrk->smcd->ops->signal_event(wrk->smcd, 336 wrk->event.tok, 337 ISM_EVENT_REQUEST_IR, 338 ISM_EVENT_CODE_TESTLINK, 339 ev_info.info); 340 } 341 break; 342 } 343 } 344 345 int smc_ism_signal_shutdown(struct smc_link_group *lgr) 346 { 347 int rc; 348 union smcd_sw_event_info ev_info; 349 350 if (lgr->peer_shutdown) 351 return 0; 352 353 memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE); 354 ev_info.vlan_id = lgr->vlan_id; 355 ev_info.code = ISM_EVENT_REQUEST; 356 rc = lgr->smcd->ops->signal_event(lgr->smcd, lgr->peer_gid, 357 ISM_EVENT_REQUEST_IR, 358 ISM_EVENT_CODE_SHUTDOWN, 359 ev_info.info); 360 return rc; 361 } 362 363 /* worker for SMC-D events */ 364 static void smc_ism_event_work(struct work_struct *work) 365 { 366 struct smc_ism_event_work *wrk = 367 container_of(work, struct smc_ism_event_work, work); 368 369 switch (wrk->event.type) { 370 case ISM_EVENT_GID: /* GID event, token is peer GID */ 371 smc_smcd_terminate(wrk->smcd, wrk->event.tok, VLAN_VID_MASK); 372 break; 373 case ISM_EVENT_DMB: 374 break; 375 case ISM_EVENT_SWR: /* Software defined event */ 376 smcd_handle_sw_event(wrk); 377 break; 378 } 379 kfree(wrk); 380 } 381 382 static void smcd_release(struct device *dev) 383 { 384 struct smcd_dev *smcd = container_of(dev, struct smcd_dev, dev); 385 386 kfree(smcd->conn); 387 kfree(smcd); 388 } 389 390 struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name, 391 const struct smcd_ops *ops, int max_dmbs) 392 { 393 struct smcd_dev *smcd; 394 395 smcd = kzalloc(sizeof(*smcd), GFP_KERNEL); 396 if (!smcd) 397 return NULL; 398 smcd->conn = kcalloc(max_dmbs, sizeof(struct smc_connection *), 399 GFP_KERNEL); 400 if (!smcd->conn) { 401 kfree(smcd); 402 return NULL; 403 } 404 405 smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)", 406 WQ_MEM_RECLAIM, name); 407 if (!smcd->event_wq) { 408 kfree(smcd->conn); 409 kfree(smcd); 410 return NULL; 411 } 412 413 smcd->dev.parent = parent; 414 smcd->dev.release = smcd_release; 415 device_initialize(&smcd->dev); 416 dev_set_name(&smcd->dev, name); 417 smcd->ops = ops; 418 if (smc_pnetid_by_dev_port(parent, 0, smcd->pnetid)) 419 smc_pnetid_by_table_smcd(smcd); 420 421 spin_lock_init(&smcd->lock); 422 spin_lock_init(&smcd->lgr_lock); 423 INIT_LIST_HEAD(&smcd->vlan); 424 INIT_LIST_HEAD(&smcd->lgr_list); 425 init_waitqueue_head(&smcd->lgrs_deleted); 426 return smcd; 427 } 428 EXPORT_SYMBOL_GPL(smcd_alloc_dev); 429 430 int smcd_register_dev(struct smcd_dev *smcd) 431 { 432 int rc; 433 434 mutex_lock(&smcd_dev_list.mutex); 435 if (list_empty(&smcd_dev_list.list)) { 436 u8 *system_eid = NULL; 437 438 smc_ism_get_system_eid(smcd, &system_eid); 439 if (system_eid[24] != '0' || system_eid[28] != '0') 440 smc_ism_v2_capable = true; 441 } 442 /* sort list: devices without pnetid before devices with pnetid */ 443 if (smcd->pnetid[0]) 444 list_add_tail(&smcd->list, &smcd_dev_list.list); 445 else 446 list_add(&smcd->list, &smcd_dev_list.list); 447 mutex_unlock(&smcd_dev_list.mutex); 448 449 pr_warn_ratelimited("smc: adding smcd device %s with pnetid %.16s%s\n", 450 dev_name(&smcd->dev), smcd->pnetid, 451 smcd->pnetid_by_user ? " (user defined)" : ""); 452 453 rc = device_add(&smcd->dev); 454 if (rc) { 455 mutex_lock(&smcd_dev_list.mutex); 456 list_del(&smcd->list); 457 mutex_unlock(&smcd_dev_list.mutex); 458 } 459 460 return rc; 461 } 462 EXPORT_SYMBOL_GPL(smcd_register_dev); 463 464 void smcd_unregister_dev(struct smcd_dev *smcd) 465 { 466 pr_warn_ratelimited("smc: removing smcd device %s\n", 467 dev_name(&smcd->dev)); 468 mutex_lock(&smcd_dev_list.mutex); 469 list_del_init(&smcd->list); 470 mutex_unlock(&smcd_dev_list.mutex); 471 smcd->going_away = 1; 472 smc_smcd_terminate_all(smcd); 473 destroy_workqueue(smcd->event_wq); 474 475 device_del(&smcd->dev); 476 } 477 EXPORT_SYMBOL_GPL(smcd_unregister_dev); 478 479 void smcd_free_dev(struct smcd_dev *smcd) 480 { 481 put_device(&smcd->dev); 482 } 483 EXPORT_SYMBOL_GPL(smcd_free_dev); 484 485 /* SMCD Device event handler. Called from ISM device interrupt handler. 486 * Parameters are smcd device pointer, 487 * - event->type (0 --> DMB, 1 --> GID), 488 * - event->code (event code), 489 * - event->tok (either DMB token when event type 0, or GID when event type 1) 490 * - event->time (time of day) 491 * - event->info (debug info). 492 * 493 * Context: 494 * - Function called in IRQ context from ISM device driver event handler. 495 */ 496 void smcd_handle_event(struct smcd_dev *smcd, struct smcd_event *event) 497 { 498 struct smc_ism_event_work *wrk; 499 500 if (smcd->going_away) 501 return; 502 /* copy event to event work queue, and let it be handled there */ 503 wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC); 504 if (!wrk) 505 return; 506 INIT_WORK(&wrk->work, smc_ism_event_work); 507 wrk->smcd = smcd; 508 wrk->event = *event; 509 queue_work(smcd->event_wq, &wrk->work); 510 } 511 EXPORT_SYMBOL_GPL(smcd_handle_event); 512 513 /* SMCD Device interrupt handler. Called from ISM device interrupt handler. 514 * Parameters are smcd device pointer and DMB number. Find the connection and 515 * schedule the tasklet for this connection. 516 * 517 * Context: 518 * - Function called in IRQ context from ISM device driver IRQ handler. 519 */ 520 void smcd_handle_irq(struct smcd_dev *smcd, unsigned int dmbno) 521 { 522 struct smc_connection *conn = NULL; 523 unsigned long flags; 524 525 spin_lock_irqsave(&smcd->lock, flags); 526 conn = smcd->conn[dmbno]; 527 if (conn && !conn->killed) 528 tasklet_schedule(&conn->rx_tsklet); 529 spin_unlock_irqrestore(&smcd->lock, flags); 530 } 531 EXPORT_SYMBOL_GPL(smcd_handle_irq); 532 533 void __init smc_ism_init(void) 534 { 535 smc_ism_v2_capable = false; 536 } 537