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 snprintf(smc_pnet, sizeof(smc_pnet), "%s", smcd->pnetid); 254 if (nla_put_string(skb, SMC_NLA_DEV_PORT_PNETID, smc_pnet)) 255 goto errportattr; 256 257 nla_nest_end(skb, port_attrs); 258 nla_nest_end(skb, attrs); 259 genlmsg_end(skb, nlh); 260 return 0; 261 262 errportattr: 263 nla_nest_cancel(skb, port_attrs); 264 errattr: 265 nla_nest_cancel(skb, attrs); 266 errout: 267 nlmsg_cancel(skb, nlh); 268 errmsg: 269 return -EMSGSIZE; 270 } 271 272 static void smc_nl_prep_smcd_dev(struct smcd_dev_list *dev_list, 273 struct sk_buff *skb, 274 struct netlink_callback *cb) 275 { 276 struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb); 277 int snum = cb_ctx->pos[0]; 278 struct smcd_dev *smcd; 279 int num = 0; 280 281 mutex_lock(&dev_list->mutex); 282 list_for_each_entry(smcd, &dev_list->list, list) { 283 if (num < snum) 284 goto next; 285 if (smc_nl_handle_smcd_dev(smcd, skb, cb)) 286 goto errout; 287 next: 288 num++; 289 } 290 errout: 291 mutex_unlock(&dev_list->mutex); 292 cb_ctx->pos[0] = num; 293 } 294 295 int smcd_nl_get_device(struct sk_buff *skb, struct netlink_callback *cb) 296 { 297 smc_nl_prep_smcd_dev(&smcd_dev_list, skb, cb); 298 return skb->len; 299 } 300 301 struct smc_ism_event_work { 302 struct work_struct work; 303 struct smcd_dev *smcd; 304 struct smcd_event event; 305 }; 306 307 #define ISM_EVENT_REQUEST 0x0001 308 #define ISM_EVENT_RESPONSE 0x0002 309 #define ISM_EVENT_REQUEST_IR 0x00000001 310 #define ISM_EVENT_CODE_SHUTDOWN 0x80 311 #define ISM_EVENT_CODE_TESTLINK 0x83 312 313 union smcd_sw_event_info { 314 u64 info; 315 struct { 316 u8 uid[SMC_LGR_ID_SIZE]; 317 unsigned short vlan_id; 318 u16 code; 319 }; 320 }; 321 322 static void smcd_handle_sw_event(struct smc_ism_event_work *wrk) 323 { 324 union smcd_sw_event_info ev_info; 325 326 ev_info.info = wrk->event.info; 327 switch (wrk->event.code) { 328 case ISM_EVENT_CODE_SHUTDOWN: /* Peer shut down DMBs */ 329 smc_smcd_terminate(wrk->smcd, wrk->event.tok, ev_info.vlan_id); 330 break; 331 case ISM_EVENT_CODE_TESTLINK: /* Activity timer */ 332 if (ev_info.code == ISM_EVENT_REQUEST) { 333 ev_info.code = ISM_EVENT_RESPONSE; 334 wrk->smcd->ops->signal_event(wrk->smcd, 335 wrk->event.tok, 336 ISM_EVENT_REQUEST_IR, 337 ISM_EVENT_CODE_TESTLINK, 338 ev_info.info); 339 } 340 break; 341 } 342 } 343 344 int smc_ism_signal_shutdown(struct smc_link_group *lgr) 345 { 346 int rc; 347 union smcd_sw_event_info ev_info; 348 349 if (lgr->peer_shutdown) 350 return 0; 351 352 memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE); 353 ev_info.vlan_id = lgr->vlan_id; 354 ev_info.code = ISM_EVENT_REQUEST; 355 rc = lgr->smcd->ops->signal_event(lgr->smcd, lgr->peer_gid, 356 ISM_EVENT_REQUEST_IR, 357 ISM_EVENT_CODE_SHUTDOWN, 358 ev_info.info); 359 return rc; 360 } 361 362 /* worker for SMC-D events */ 363 static void smc_ism_event_work(struct work_struct *work) 364 { 365 struct smc_ism_event_work *wrk = 366 container_of(work, struct smc_ism_event_work, work); 367 368 switch (wrk->event.type) { 369 case ISM_EVENT_GID: /* GID event, token is peer GID */ 370 smc_smcd_terminate(wrk->smcd, wrk->event.tok, VLAN_VID_MASK); 371 break; 372 case ISM_EVENT_DMB: 373 break; 374 case ISM_EVENT_SWR: /* Software defined event */ 375 smcd_handle_sw_event(wrk); 376 break; 377 } 378 kfree(wrk); 379 } 380 381 static void smcd_release(struct device *dev) 382 { 383 struct smcd_dev *smcd = container_of(dev, struct smcd_dev, dev); 384 385 kfree(smcd->conn); 386 kfree(smcd); 387 } 388 389 struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name, 390 const struct smcd_ops *ops, int max_dmbs) 391 { 392 struct smcd_dev *smcd; 393 394 smcd = kzalloc(sizeof(*smcd), GFP_KERNEL); 395 if (!smcd) 396 return NULL; 397 smcd->conn = kcalloc(max_dmbs, sizeof(struct smc_connection *), 398 GFP_KERNEL); 399 if (!smcd->conn) { 400 kfree(smcd); 401 return NULL; 402 } 403 404 smcd->dev.parent = parent; 405 smcd->dev.release = smcd_release; 406 device_initialize(&smcd->dev); 407 dev_set_name(&smcd->dev, name); 408 smcd->ops = ops; 409 if (smc_pnetid_by_dev_port(parent, 0, smcd->pnetid)) 410 smc_pnetid_by_table_smcd(smcd); 411 412 spin_lock_init(&smcd->lock); 413 spin_lock_init(&smcd->lgr_lock); 414 INIT_LIST_HEAD(&smcd->vlan); 415 INIT_LIST_HEAD(&smcd->lgr_list); 416 init_waitqueue_head(&smcd->lgrs_deleted); 417 smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)", 418 WQ_MEM_RECLAIM, name); 419 if (!smcd->event_wq) { 420 kfree(smcd->conn); 421 kfree(smcd); 422 return NULL; 423 } 424 return smcd; 425 } 426 EXPORT_SYMBOL_GPL(smcd_alloc_dev); 427 428 int smcd_register_dev(struct smcd_dev *smcd) 429 { 430 mutex_lock(&smcd_dev_list.mutex); 431 if (list_empty(&smcd_dev_list.list)) { 432 u8 *system_eid = NULL; 433 434 smc_ism_get_system_eid(smcd, &system_eid); 435 if (system_eid[24] != '0' || system_eid[28] != '0') 436 smc_ism_v2_capable = true; 437 } 438 /* sort list: devices without pnetid before devices with pnetid */ 439 if (smcd->pnetid[0]) 440 list_add_tail(&smcd->list, &smcd_dev_list.list); 441 else 442 list_add(&smcd->list, &smcd_dev_list.list); 443 mutex_unlock(&smcd_dev_list.mutex); 444 445 pr_warn_ratelimited("smc: adding smcd device %s with pnetid %.16s%s\n", 446 dev_name(&smcd->dev), smcd->pnetid, 447 smcd->pnetid_by_user ? " (user defined)" : ""); 448 449 return device_add(&smcd->dev); 450 } 451 EXPORT_SYMBOL_GPL(smcd_register_dev); 452 453 void smcd_unregister_dev(struct smcd_dev *smcd) 454 { 455 pr_warn_ratelimited("smc: removing smcd device %s\n", 456 dev_name(&smcd->dev)); 457 mutex_lock(&smcd_dev_list.mutex); 458 list_del_init(&smcd->list); 459 mutex_unlock(&smcd_dev_list.mutex); 460 smcd->going_away = 1; 461 smc_smcd_terminate_all(smcd); 462 flush_workqueue(smcd->event_wq); 463 destroy_workqueue(smcd->event_wq); 464 465 device_del(&smcd->dev); 466 } 467 EXPORT_SYMBOL_GPL(smcd_unregister_dev); 468 469 void smcd_free_dev(struct smcd_dev *smcd) 470 { 471 put_device(&smcd->dev); 472 } 473 EXPORT_SYMBOL_GPL(smcd_free_dev); 474 475 /* SMCD Device event handler. Called from ISM device interrupt handler. 476 * Parameters are smcd device pointer, 477 * - event->type (0 --> DMB, 1 --> GID), 478 * - event->code (event code), 479 * - event->tok (either DMB token when event type 0, or GID when event type 1) 480 * - event->time (time of day) 481 * - event->info (debug info). 482 * 483 * Context: 484 * - Function called in IRQ context from ISM device driver event handler. 485 */ 486 void smcd_handle_event(struct smcd_dev *smcd, struct smcd_event *event) 487 { 488 struct smc_ism_event_work *wrk; 489 490 if (smcd->going_away) 491 return; 492 /* copy event to event work queue, and let it be handled there */ 493 wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC); 494 if (!wrk) 495 return; 496 INIT_WORK(&wrk->work, smc_ism_event_work); 497 wrk->smcd = smcd; 498 wrk->event = *event; 499 queue_work(smcd->event_wq, &wrk->work); 500 } 501 EXPORT_SYMBOL_GPL(smcd_handle_event); 502 503 /* SMCD Device interrupt handler. Called from ISM device interrupt handler. 504 * Parameters are smcd device pointer and DMB number. Find the connection and 505 * schedule the tasklet for this connection. 506 * 507 * Context: 508 * - Function called in IRQ context from ISM device driver IRQ handler. 509 */ 510 void smcd_handle_irq(struct smcd_dev *smcd, unsigned int dmbno) 511 { 512 struct smc_connection *conn = NULL; 513 unsigned long flags; 514 515 spin_lock_irqsave(&smcd->lock, flags); 516 conn = smcd->conn[dmbno]; 517 if (conn && !conn->killed) 518 tasklet_schedule(&conn->rx_tsklet); 519 spin_unlock_irqrestore(&smcd->lock, flags); 520 } 521 EXPORT_SYMBOL_GPL(smcd_handle_irq); 522 523 void __init smc_ism_init(void) 524 { 525 smc_ism_v2_capable = false; 526 } 527