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/if_vlan.h> 10#include <linux/spinlock.h> 11#include <linux/mutex.h> 12#include <linux/slab.h> 13#include <asm/page.h> 14 15#include "smc.h" 16#include "smc_core.h" 17#include "smc_ism.h" 18#include "smc_pnet.h" 19#include "smc_netlink.h" 20#include "linux/ism.h" 21 22struct smcd_dev_list smcd_dev_list = { 23 .list = LIST_HEAD_INIT(smcd_dev_list.list), 24 .mutex = __MUTEX_INITIALIZER(smcd_dev_list.mutex) 25}; 26 27static bool smc_ism_v2_capable; 28static u8 smc_ism_v2_system_eid[SMC_MAX_EID_LEN]; 29 30#if IS_ENABLED(CONFIG_ISM) 31static void smcd_register_dev(struct ism_dev *ism); 32static void smcd_unregister_dev(struct ism_dev *ism); 33static void smcd_handle_event(struct ism_dev *ism, struct ism_event *event); 34static void smcd_handle_irq(struct ism_dev *ism, unsigned int dmbno, 35 u16 dmbemask); 36 37static struct ism_client smc_ism_client = { 38 .name = "SMC-D", 39 .add = smcd_register_dev, 40 .remove = smcd_unregister_dev, 41 .handle_event = smcd_handle_event, 42 .handle_irq = smcd_handle_irq, 43}; 44#endif 45 46/* Test if an ISM communication is possible - same CPC */ 47int smc_ism_cantalk(u64 peer_gid, unsigned short vlan_id, struct smcd_dev *smcd) 48{ 49 return smcd->ops->query_remote_gid(smcd, peer_gid, vlan_id ? 1 : 0, 50 vlan_id); 51} 52 53void smc_ism_get_system_eid(u8 **eid) 54{ 55 if (!smc_ism_v2_capable) 56 *eid = NULL; 57 else 58 *eid = smc_ism_v2_system_eid; 59} 60 61u16 smc_ism_get_chid(struct smcd_dev *smcd) 62{ 63 return smcd->ops->get_chid(smcd); 64} 65 66/* HW supports ISM V2 and thus System EID is defined */ 67bool smc_ism_is_v2_capable(void) 68{ 69 return smc_ism_v2_capable; 70} 71 72/* Set a connection using this DMBE. */ 73void smc_ism_set_conn(struct smc_connection *conn) 74{ 75 unsigned long flags; 76 77 spin_lock_irqsave(&conn->lgr->smcd->lock, flags); 78 conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = conn; 79 spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags); 80} 81 82/* Unset a connection using this DMBE. */ 83void smc_ism_unset_conn(struct smc_connection *conn) 84{ 85 unsigned long flags; 86 87 if (!conn->rmb_desc) 88 return; 89 90 spin_lock_irqsave(&conn->lgr->smcd->lock, flags); 91 conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = NULL; 92 spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags); 93} 94 95/* Register a VLAN identifier with the ISM device. Use a reference count 96 * and add a VLAN identifier only when the first DMB using this VLAN is 97 * registered. 98 */ 99int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid) 100{ 101 struct smc_ism_vlanid *new_vlan, *vlan; 102 unsigned long flags; 103 int rc = 0; 104 105 if (!vlanid) /* No valid vlan id */ 106 return -EINVAL; 107 108 /* create new vlan entry, in case we need it */ 109 new_vlan = kzalloc(sizeof(*new_vlan), GFP_KERNEL); 110 if (!new_vlan) 111 return -ENOMEM; 112 new_vlan->vlanid = vlanid; 113 refcount_set(&new_vlan->refcnt, 1); 114 115 /* if there is an existing entry, increase count and return */ 116 spin_lock_irqsave(&smcd->lock, flags); 117 list_for_each_entry(vlan, &smcd->vlan, list) { 118 if (vlan->vlanid == vlanid) { 119 refcount_inc(&vlan->refcnt); 120 kfree(new_vlan); 121 goto out; 122 } 123 } 124 125 /* no existing entry found. 126 * add new entry to device; might fail, e.g., if HW limit reached 127 */ 128 if (smcd->ops->add_vlan_id(smcd, vlanid)) { 129 kfree(new_vlan); 130 rc = -EIO; 131 goto out; 132 } 133 list_add_tail(&new_vlan->list, &smcd->vlan); 134out: 135 spin_unlock_irqrestore(&smcd->lock, flags); 136 return rc; 137} 138 139/* Unregister a VLAN identifier with the ISM device. Use a reference count 140 * and remove a VLAN identifier only when the last DMB using this VLAN is 141 * unregistered. 142 */ 143int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid) 144{ 145 struct smc_ism_vlanid *vlan; 146 unsigned long flags; 147 bool found = false; 148 int rc = 0; 149 150 if (!vlanid) /* No valid vlan id */ 151 return -EINVAL; 152 153 spin_lock_irqsave(&smcd->lock, flags); 154 list_for_each_entry(vlan, &smcd->vlan, list) { 155 if (vlan->vlanid == vlanid) { 156 if (!refcount_dec_and_test(&vlan->refcnt)) 157 goto out; 158 found = true; 159 break; 160 } 161 } 162 if (!found) { 163 rc = -ENOENT; 164 goto out; /* VLAN id not in table */ 165 } 166 167 /* Found and the last reference just gone */ 168 if (smcd->ops->del_vlan_id(smcd, vlanid)) 169 rc = -EIO; 170 list_del(&vlan->list); 171 kfree(vlan); 172out: 173 spin_unlock_irqrestore(&smcd->lock, flags); 174 return rc; 175} 176 177int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc) 178{ 179 struct smcd_dmb dmb; 180 int rc = 0; 181 182 if (!dmb_desc->dma_addr) 183 return rc; 184 185 memset(&dmb, 0, sizeof(dmb)); 186 dmb.dmb_tok = dmb_desc->token; 187 dmb.sba_idx = dmb_desc->sba_idx; 188 dmb.cpu_addr = dmb_desc->cpu_addr; 189 dmb.dma_addr = dmb_desc->dma_addr; 190 dmb.dmb_len = dmb_desc->len; 191 rc = smcd->ops->unregister_dmb(smcd, &dmb); 192 if (!rc || rc == ISM_ERROR) { 193 dmb_desc->cpu_addr = NULL; 194 dmb_desc->dma_addr = 0; 195 } 196 197 return rc; 198} 199 200int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len, 201 struct smc_buf_desc *dmb_desc) 202{ 203#if IS_ENABLED(CONFIG_ISM) 204 struct smcd_dmb dmb; 205 int rc; 206 207 memset(&dmb, 0, sizeof(dmb)); 208 dmb.dmb_len = dmb_len; 209 dmb.sba_idx = dmb_desc->sba_idx; 210 dmb.vlan_id = lgr->vlan_id; 211 dmb.rgid = lgr->peer_gid; 212 rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb, &smc_ism_client); 213 if (!rc) { 214 dmb_desc->sba_idx = dmb.sba_idx; 215 dmb_desc->token = dmb.dmb_tok; 216 dmb_desc->cpu_addr = dmb.cpu_addr; 217 dmb_desc->dma_addr = dmb.dma_addr; 218 dmb_desc->len = dmb.dmb_len; 219 } 220 return rc; 221#else 222 return 0; 223#endif 224} 225 226static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd, 227 struct sk_buff *skb, 228 struct netlink_callback *cb) 229{ 230 char smc_pnet[SMC_MAX_PNETID_LEN + 1]; 231 struct smc_pci_dev smc_pci_dev; 232 struct nlattr *port_attrs; 233 struct nlattr *attrs; 234 struct ism_dev *ism; 235 int use_cnt = 0; 236 void *nlh; 237 238 ism = smcd->priv; 239 nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, 240 &smc_gen_nl_family, NLM_F_MULTI, 241 SMC_NETLINK_GET_DEV_SMCD); 242 if (!nlh) 243 goto errmsg; 244 attrs = nla_nest_start(skb, SMC_GEN_DEV_SMCD); 245 if (!attrs) 246 goto errout; 247 use_cnt = atomic_read(&smcd->lgr_cnt); 248 if (nla_put_u32(skb, SMC_NLA_DEV_USE_CNT, use_cnt)) 249 goto errattr; 250 if (nla_put_u8(skb, SMC_NLA_DEV_IS_CRIT, use_cnt > 0)) 251 goto errattr; 252 memset(&smc_pci_dev, 0, sizeof(smc_pci_dev)); 253 smc_set_pci_values(to_pci_dev(ism->dev.parent), &smc_pci_dev); 254 if (nla_put_u32(skb, SMC_NLA_DEV_PCI_FID, smc_pci_dev.pci_fid)) 255 goto errattr; 256 if (nla_put_u16(skb, SMC_NLA_DEV_PCI_CHID, smc_pci_dev.pci_pchid)) 257 goto errattr; 258 if (nla_put_u16(skb, SMC_NLA_DEV_PCI_VENDOR, smc_pci_dev.pci_vendor)) 259 goto errattr; 260 if (nla_put_u16(skb, SMC_NLA_DEV_PCI_DEVICE, smc_pci_dev.pci_device)) 261 goto errattr; 262 if (nla_put_string(skb, SMC_NLA_DEV_PCI_ID, smc_pci_dev.pci_id)) 263 goto errattr; 264 265 port_attrs = nla_nest_start(skb, SMC_NLA_DEV_PORT); 266 if (!port_attrs) 267 goto errattr; 268 if (nla_put_u8(skb, SMC_NLA_DEV_PORT_PNET_USR, smcd->pnetid_by_user)) 269 goto errportattr; 270 memcpy(smc_pnet, smcd->pnetid, SMC_MAX_PNETID_LEN); 271 smc_pnet[SMC_MAX_PNETID_LEN] = 0; 272 if (nla_put_string(skb, SMC_NLA_DEV_PORT_PNETID, smc_pnet)) 273 goto errportattr; 274 275 nla_nest_end(skb, port_attrs); 276 nla_nest_end(skb, attrs); 277 genlmsg_end(skb, nlh); 278 return 0; 279 280errportattr: 281 nla_nest_cancel(skb, port_attrs); 282errattr: 283 nla_nest_cancel(skb, attrs); 284errout: 285 nlmsg_cancel(skb, nlh); 286errmsg: 287 return -EMSGSIZE; 288} 289 290static void smc_nl_prep_smcd_dev(struct smcd_dev_list *dev_list, 291 struct sk_buff *skb, 292 struct netlink_callback *cb) 293{ 294 struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb); 295 int snum = cb_ctx->pos[0]; 296 struct smcd_dev *smcd; 297 int num = 0; 298 299 mutex_lock(&dev_list->mutex); 300 list_for_each_entry(smcd, &dev_list->list, list) { 301 if (num < snum) 302 goto next; 303 if (smc_nl_handle_smcd_dev(smcd, skb, cb)) 304 goto errout; 305next: 306 num++; 307 } 308errout: 309 mutex_unlock(&dev_list->mutex); 310 cb_ctx->pos[0] = num; 311} 312 313int smcd_nl_get_device(struct sk_buff *skb, struct netlink_callback *cb) 314{ 315 smc_nl_prep_smcd_dev(&smcd_dev_list, skb, cb); 316 return skb->len; 317} 318 319#if IS_ENABLED(CONFIG_ISM) 320struct smc_ism_event_work { 321 struct work_struct work; 322 struct smcd_dev *smcd; 323 struct ism_event event; 324}; 325 326#define ISM_EVENT_REQUEST 0x0001 327#define ISM_EVENT_RESPONSE 0x0002 328#define ISM_EVENT_REQUEST_IR 0x00000001 329#define ISM_EVENT_CODE_SHUTDOWN 0x80 330#define ISM_EVENT_CODE_TESTLINK 0x83 331 332union smcd_sw_event_info { 333 u64 info; 334 struct { 335 u8 uid[SMC_LGR_ID_SIZE]; 336 unsigned short vlan_id; 337 u16 code; 338 }; 339}; 340 341static void smcd_handle_sw_event(struct smc_ism_event_work *wrk) 342{ 343 union smcd_sw_event_info ev_info; 344 345 ev_info.info = wrk->event.info; 346 switch (wrk->event.code) { 347 case ISM_EVENT_CODE_SHUTDOWN: /* Peer shut down DMBs */ 348 smc_smcd_terminate(wrk->smcd, wrk->event.tok, ev_info.vlan_id); 349 break; 350 case ISM_EVENT_CODE_TESTLINK: /* Activity timer */ 351 if (ev_info.code == ISM_EVENT_REQUEST) { 352 ev_info.code = ISM_EVENT_RESPONSE; 353 wrk->smcd->ops->signal_event(wrk->smcd, 354 wrk->event.tok, 355 ISM_EVENT_REQUEST_IR, 356 ISM_EVENT_CODE_TESTLINK, 357 ev_info.info); 358 } 359 break; 360 } 361} 362 363/* worker for SMC-D events */ 364static 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 382static struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name, 383 const struct smcd_ops *ops, int max_dmbs) 384{ 385 struct smcd_dev *smcd; 386 387 smcd = devm_kzalloc(parent, sizeof(*smcd), GFP_KERNEL); 388 if (!smcd) 389 return NULL; 390 smcd->conn = devm_kcalloc(parent, max_dmbs, 391 sizeof(struct smc_connection *), GFP_KERNEL); 392 if (!smcd->conn) 393 return NULL; 394 395 smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)", 396 WQ_MEM_RECLAIM, name); 397 if (!smcd->event_wq) 398 return NULL; 399 400 smcd->ops = ops; 401 402 spin_lock_init(&smcd->lock); 403 spin_lock_init(&smcd->lgr_lock); 404 INIT_LIST_HEAD(&smcd->vlan); 405 INIT_LIST_HEAD(&smcd->lgr_list); 406 init_waitqueue_head(&smcd->lgrs_deleted); 407 return smcd; 408} 409 410static void smcd_register_dev(struct ism_dev *ism) 411{ 412 const struct smcd_ops *ops = ism_get_smcd_ops(); 413 struct smcd_dev *smcd; 414 415 if (!ops) 416 return; 417 418 smcd = smcd_alloc_dev(&ism->pdev->dev, dev_name(&ism->pdev->dev), ops, 419 ISM_NR_DMBS); 420 if (!smcd) 421 return; 422 smcd->priv = ism; 423 ism_set_priv(ism, &smc_ism_client, smcd); 424 if (smc_pnetid_by_dev_port(&ism->pdev->dev, 0, smcd->pnetid)) 425 smc_pnetid_by_table_smcd(smcd); 426 427 mutex_lock(&smcd_dev_list.mutex); 428 if (list_empty(&smcd_dev_list.list)) { 429 u8 *system_eid = NULL; 430 431 system_eid = smcd->ops->get_system_eid(); 432 if (smcd->ops->supports_v2()) { 433 smc_ism_v2_capable = true; 434 memcpy(smc_ism_v2_system_eid, system_eid, 435 SMC_MAX_EID_LEN); 436 } 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(&ism->dev), smcd->pnetid, 447 smcd->pnetid_by_user ? " (user defined)" : ""); 448 449 return; 450} 451 452static void smcd_unregister_dev(struct ism_dev *ism) 453{ 454 struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client); 455 456 pr_warn_ratelimited("smc: removing smcd device %s\n", 457 dev_name(&ism->dev)); 458 smcd->going_away = 1; 459 smc_smcd_terminate_all(smcd); 460 mutex_lock(&smcd_dev_list.mutex); 461 list_del_init(&smcd->list); 462 mutex_unlock(&smcd_dev_list.mutex); 463 destroy_workqueue(smcd->event_wq); 464} 465 466/* SMCD Device event handler. Called from ISM device interrupt handler. 467 * Parameters are ism device pointer, 468 * - event->type (0 --> DMB, 1 --> GID), 469 * - event->code (event code), 470 * - event->tok (either DMB token when event type 0, or GID when event type 1) 471 * - event->time (time of day) 472 * - event->info (debug info). 473 * 474 * Context: 475 * - Function called in IRQ context from ISM device driver event handler. 476 */ 477static void smcd_handle_event(struct ism_dev *ism, struct ism_event *event) 478{ 479 struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client); 480 struct smc_ism_event_work *wrk; 481 482 if (smcd->going_away) 483 return; 484 /* copy event to event work queue, and let it be handled there */ 485 wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC); 486 if (!wrk) 487 return; 488 INIT_WORK(&wrk->work, smc_ism_event_work); 489 wrk->smcd = smcd; 490 wrk->event = *event; 491 queue_work(smcd->event_wq, &wrk->work); 492} 493 494/* SMCD Device interrupt handler. Called from ISM device interrupt handler. 495 * Parameters are the ism device pointer, DMB number, and the DMBE bitmask. 496 * Find the connection and schedule the tasklet for this connection. 497 * 498 * Context: 499 * - Function called in IRQ context from ISM device driver IRQ handler. 500 */ 501static void smcd_handle_irq(struct ism_dev *ism, unsigned int dmbno, 502 u16 dmbemask) 503{ 504 struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client); 505 struct smc_connection *conn = NULL; 506 unsigned long flags; 507 508 spin_lock_irqsave(&smcd->lock, flags); 509 conn = smcd->conn[dmbno]; 510 if (conn && !conn->killed) 511 tasklet_schedule(&conn->rx_tsklet); 512 spin_unlock_irqrestore(&smcd->lock, flags); 513} 514#endif 515 516int smc_ism_signal_shutdown(struct smc_link_group *lgr) 517{ 518 int rc = 0; 519#if IS_ENABLED(CONFIG_ISM) 520 union smcd_sw_event_info ev_info; 521 522 if (lgr->peer_shutdown) 523 return 0; 524 525 memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE); 526 ev_info.vlan_id = lgr->vlan_id; 527 ev_info.code = ISM_EVENT_REQUEST; 528 rc = lgr->smcd->ops->signal_event(lgr->smcd, lgr->peer_gid, 529 ISM_EVENT_REQUEST_IR, 530 ISM_EVENT_CODE_SHUTDOWN, 531 ev_info.info); 532#endif 533 return rc; 534} 535 536int smc_ism_init(void) 537{ 538 int rc = 0; 539 540#if IS_ENABLED(CONFIG_ISM) 541 smc_ism_v2_capable = false; 542 memset(smc_ism_v2_system_eid, 0, SMC_MAX_EID_LEN); 543 544 rc = ism_register_client(&smc_ism_client); 545#endif 546 return rc; 547} 548 549void smc_ism_exit(void) 550{ 551#if IS_ENABLED(CONFIG_ISM) 552 ism_unregister_client(&smc_ism_client); 553#endif 554} 555