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 19 struct smcd_dev_list smcd_dev_list = { 20 .list = LIST_HEAD_INIT(smcd_dev_list.list), 21 .mutex = __MUTEX_INITIALIZER(smcd_dev_list.mutex) 22 }; 23 24 bool smc_ism_v2_capable; 25 26 /* Test if an ISM communication is possible - same CPC */ 27 int smc_ism_cantalk(u64 peer_gid, unsigned short vlan_id, struct smcd_dev *smcd) 28 { 29 return smcd->ops->query_remote_gid(smcd, peer_gid, vlan_id ? 1 : 0, 30 vlan_id); 31 } 32 33 int smc_ism_write(struct smcd_dev *smcd, const struct smc_ism_position *pos, 34 void *data, size_t len) 35 { 36 int rc; 37 38 rc = smcd->ops->move_data(smcd, pos->token, pos->index, pos->signal, 39 pos->offset, data, len); 40 41 return rc < 0 ? rc : 0; 42 } 43 44 void smc_ism_get_system_eid(struct smcd_dev *smcd, u8 **eid) 45 { 46 smcd->ops->get_system_eid(smcd, eid); 47 } 48 49 u16 smc_ism_get_chid(struct smcd_dev *smcd) 50 { 51 return smcd->ops->get_chid(smcd); 52 } 53 54 /* Set a connection using this DMBE. */ 55 void smc_ism_set_conn(struct smc_connection *conn) 56 { 57 unsigned long flags; 58 59 spin_lock_irqsave(&conn->lgr->smcd->lock, flags); 60 conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = conn; 61 spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags); 62 } 63 64 /* Unset a connection using this DMBE. */ 65 void smc_ism_unset_conn(struct smc_connection *conn) 66 { 67 unsigned long flags; 68 69 if (!conn->rmb_desc) 70 return; 71 72 spin_lock_irqsave(&conn->lgr->smcd->lock, flags); 73 conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = NULL; 74 spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags); 75 } 76 77 /* Register a VLAN identifier with the ISM device. Use a reference count 78 * and add a VLAN identifier only when the first DMB using this VLAN is 79 * registered. 80 */ 81 int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid) 82 { 83 struct smc_ism_vlanid *new_vlan, *vlan; 84 unsigned long flags; 85 int rc = 0; 86 87 if (!vlanid) /* No valid vlan id */ 88 return -EINVAL; 89 90 /* create new vlan entry, in case we need it */ 91 new_vlan = kzalloc(sizeof(*new_vlan), GFP_KERNEL); 92 if (!new_vlan) 93 return -ENOMEM; 94 new_vlan->vlanid = vlanid; 95 refcount_set(&new_vlan->refcnt, 1); 96 97 /* if there is an existing entry, increase count and return */ 98 spin_lock_irqsave(&smcd->lock, flags); 99 list_for_each_entry(vlan, &smcd->vlan, list) { 100 if (vlan->vlanid == vlanid) { 101 refcount_inc(&vlan->refcnt); 102 kfree(new_vlan); 103 goto out; 104 } 105 } 106 107 /* no existing entry found. 108 * add new entry to device; might fail, e.g., if HW limit reached 109 */ 110 if (smcd->ops->add_vlan_id(smcd, vlanid)) { 111 kfree(new_vlan); 112 rc = -EIO; 113 goto out; 114 } 115 list_add_tail(&new_vlan->list, &smcd->vlan); 116 out: 117 spin_unlock_irqrestore(&smcd->lock, flags); 118 return rc; 119 } 120 121 /* Unregister a VLAN identifier with the ISM device. Use a reference count 122 * and remove a VLAN identifier only when the last DMB using this VLAN is 123 * unregistered. 124 */ 125 int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid) 126 { 127 struct smc_ism_vlanid *vlan; 128 unsigned long flags; 129 bool found = false; 130 int rc = 0; 131 132 if (!vlanid) /* No valid vlan id */ 133 return -EINVAL; 134 135 spin_lock_irqsave(&smcd->lock, flags); 136 list_for_each_entry(vlan, &smcd->vlan, list) { 137 if (vlan->vlanid == vlanid) { 138 if (!refcount_dec_and_test(&vlan->refcnt)) 139 goto out; 140 found = true; 141 break; 142 } 143 } 144 if (!found) { 145 rc = -ENOENT; 146 goto out; /* VLAN id not in table */ 147 } 148 149 /* Found and the last reference just gone */ 150 if (smcd->ops->del_vlan_id(smcd, vlanid)) 151 rc = -EIO; 152 list_del(&vlan->list); 153 kfree(vlan); 154 out: 155 spin_unlock_irqrestore(&smcd->lock, flags); 156 return rc; 157 } 158 159 int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc) 160 { 161 struct smcd_dmb dmb; 162 int rc = 0; 163 164 if (!dmb_desc->dma_addr) 165 return rc; 166 167 memset(&dmb, 0, sizeof(dmb)); 168 dmb.dmb_tok = dmb_desc->token; 169 dmb.sba_idx = dmb_desc->sba_idx; 170 dmb.cpu_addr = dmb_desc->cpu_addr; 171 dmb.dma_addr = dmb_desc->dma_addr; 172 dmb.dmb_len = dmb_desc->len; 173 rc = smcd->ops->unregister_dmb(smcd, &dmb); 174 if (!rc || rc == ISM_ERROR) { 175 dmb_desc->cpu_addr = NULL; 176 dmb_desc->dma_addr = 0; 177 } 178 179 return rc; 180 } 181 182 int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len, 183 struct smc_buf_desc *dmb_desc) 184 { 185 struct smcd_dmb dmb; 186 int rc; 187 188 memset(&dmb, 0, sizeof(dmb)); 189 dmb.dmb_len = dmb_len; 190 dmb.sba_idx = dmb_desc->sba_idx; 191 dmb.vlan_id = lgr->vlan_id; 192 dmb.rgid = lgr->peer_gid; 193 rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb); 194 if (!rc) { 195 dmb_desc->sba_idx = dmb.sba_idx; 196 dmb_desc->token = dmb.dmb_tok; 197 dmb_desc->cpu_addr = dmb.cpu_addr; 198 dmb_desc->dma_addr = dmb.dma_addr; 199 dmb_desc->len = dmb.dmb_len; 200 } 201 return rc; 202 } 203 204 struct smc_ism_event_work { 205 struct work_struct work; 206 struct smcd_dev *smcd; 207 struct smcd_event event; 208 }; 209 210 #define ISM_EVENT_REQUEST 0x0001 211 #define ISM_EVENT_RESPONSE 0x0002 212 #define ISM_EVENT_REQUEST_IR 0x00000001 213 #define ISM_EVENT_CODE_SHUTDOWN 0x80 214 #define ISM_EVENT_CODE_TESTLINK 0x83 215 216 union smcd_sw_event_info { 217 u64 info; 218 struct { 219 u8 uid[SMC_LGR_ID_SIZE]; 220 unsigned short vlan_id; 221 u16 code; 222 }; 223 }; 224 225 static void smcd_handle_sw_event(struct smc_ism_event_work *wrk) 226 { 227 union smcd_sw_event_info ev_info; 228 229 ev_info.info = wrk->event.info; 230 switch (wrk->event.code) { 231 case ISM_EVENT_CODE_SHUTDOWN: /* Peer shut down DMBs */ 232 smc_smcd_terminate(wrk->smcd, wrk->event.tok, ev_info.vlan_id); 233 break; 234 case ISM_EVENT_CODE_TESTLINK: /* Activity timer */ 235 if (ev_info.code == ISM_EVENT_REQUEST) { 236 ev_info.code = ISM_EVENT_RESPONSE; 237 wrk->smcd->ops->signal_event(wrk->smcd, 238 wrk->event.tok, 239 ISM_EVENT_REQUEST_IR, 240 ISM_EVENT_CODE_TESTLINK, 241 ev_info.info); 242 } 243 break; 244 } 245 } 246 247 int smc_ism_signal_shutdown(struct smc_link_group *lgr) 248 { 249 int rc; 250 union smcd_sw_event_info ev_info; 251 252 if (lgr->peer_shutdown) 253 return 0; 254 255 memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE); 256 ev_info.vlan_id = lgr->vlan_id; 257 ev_info.code = ISM_EVENT_REQUEST; 258 rc = lgr->smcd->ops->signal_event(lgr->smcd, lgr->peer_gid, 259 ISM_EVENT_REQUEST_IR, 260 ISM_EVENT_CODE_SHUTDOWN, 261 ev_info.info); 262 return rc; 263 } 264 265 /* worker for SMC-D events */ 266 static void smc_ism_event_work(struct work_struct *work) 267 { 268 struct smc_ism_event_work *wrk = 269 container_of(work, struct smc_ism_event_work, work); 270 271 switch (wrk->event.type) { 272 case ISM_EVENT_GID: /* GID event, token is peer GID */ 273 smc_smcd_terminate(wrk->smcd, wrk->event.tok, VLAN_VID_MASK); 274 break; 275 case ISM_EVENT_DMB: 276 break; 277 case ISM_EVENT_SWR: /* Software defined event */ 278 smcd_handle_sw_event(wrk); 279 break; 280 } 281 kfree(wrk); 282 } 283 284 static void smcd_release(struct device *dev) 285 { 286 struct smcd_dev *smcd = container_of(dev, struct smcd_dev, dev); 287 288 kfree(smcd->conn); 289 kfree(smcd); 290 } 291 292 struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name, 293 const struct smcd_ops *ops, int max_dmbs) 294 { 295 struct smcd_dev *smcd; 296 297 smcd = kzalloc(sizeof(*smcd), GFP_KERNEL); 298 if (!smcd) 299 return NULL; 300 smcd->conn = kcalloc(max_dmbs, sizeof(struct smc_connection *), 301 GFP_KERNEL); 302 if (!smcd->conn) { 303 kfree(smcd); 304 return NULL; 305 } 306 307 smcd->dev.parent = parent; 308 smcd->dev.release = smcd_release; 309 device_initialize(&smcd->dev); 310 dev_set_name(&smcd->dev, name); 311 smcd->ops = ops; 312 if (smc_pnetid_by_dev_port(parent, 0, smcd->pnetid)) 313 smc_pnetid_by_table_smcd(smcd); 314 315 spin_lock_init(&smcd->lock); 316 spin_lock_init(&smcd->lgr_lock); 317 INIT_LIST_HEAD(&smcd->vlan); 318 INIT_LIST_HEAD(&smcd->lgr_list); 319 init_waitqueue_head(&smcd->lgrs_deleted); 320 smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)", 321 WQ_MEM_RECLAIM, name); 322 if (!smcd->event_wq) { 323 kfree(smcd->conn); 324 kfree(smcd); 325 return NULL; 326 } 327 return smcd; 328 } 329 EXPORT_SYMBOL_GPL(smcd_alloc_dev); 330 331 int smcd_register_dev(struct smcd_dev *smcd) 332 { 333 mutex_lock(&smcd_dev_list.mutex); 334 if (list_empty(&smcd_dev_list.list)) { 335 u8 *system_eid = NULL; 336 337 smc_ism_get_system_eid(smcd, &system_eid); 338 if (system_eid[24] != '0' || system_eid[28] != '0') 339 smc_ism_v2_capable = true; 340 } 341 /* sort list: devices without pnetid before devices with pnetid */ 342 if (smcd->pnetid[0]) 343 list_add_tail(&smcd->list, &smcd_dev_list.list); 344 else 345 list_add(&smcd->list, &smcd_dev_list.list); 346 mutex_unlock(&smcd_dev_list.mutex); 347 348 pr_warn_ratelimited("smc: adding smcd device %s with pnetid %.16s%s\n", 349 dev_name(&smcd->dev), smcd->pnetid, 350 smcd->pnetid_by_user ? " (user defined)" : ""); 351 352 return device_add(&smcd->dev); 353 } 354 EXPORT_SYMBOL_GPL(smcd_register_dev); 355 356 void smcd_unregister_dev(struct smcd_dev *smcd) 357 { 358 pr_warn_ratelimited("smc: removing smcd device %s\n", 359 dev_name(&smcd->dev)); 360 mutex_lock(&smcd_dev_list.mutex); 361 list_del_init(&smcd->list); 362 mutex_unlock(&smcd_dev_list.mutex); 363 smcd->going_away = 1; 364 smc_smcd_terminate_all(smcd); 365 flush_workqueue(smcd->event_wq); 366 destroy_workqueue(smcd->event_wq); 367 368 device_del(&smcd->dev); 369 } 370 EXPORT_SYMBOL_GPL(smcd_unregister_dev); 371 372 void smcd_free_dev(struct smcd_dev *smcd) 373 { 374 put_device(&smcd->dev); 375 } 376 EXPORT_SYMBOL_GPL(smcd_free_dev); 377 378 /* SMCD Device event handler. Called from ISM device interrupt handler. 379 * Parameters are smcd device pointer, 380 * - event->type (0 --> DMB, 1 --> GID), 381 * - event->code (event code), 382 * - event->tok (either DMB token when event type 0, or GID when event type 1) 383 * - event->time (time of day) 384 * - event->info (debug info). 385 * 386 * Context: 387 * - Function called in IRQ context from ISM device driver event handler. 388 */ 389 void smcd_handle_event(struct smcd_dev *smcd, struct smcd_event *event) 390 { 391 struct smc_ism_event_work *wrk; 392 393 if (smcd->going_away) 394 return; 395 /* copy event to event work queue, and let it be handled there */ 396 wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC); 397 if (!wrk) 398 return; 399 INIT_WORK(&wrk->work, smc_ism_event_work); 400 wrk->smcd = smcd; 401 wrk->event = *event; 402 queue_work(smcd->event_wq, &wrk->work); 403 } 404 EXPORT_SYMBOL_GPL(smcd_handle_event); 405 406 /* SMCD Device interrupt handler. Called from ISM device interrupt handler. 407 * Parameters are smcd device pointer and DMB number. Find the connection and 408 * schedule the tasklet for this connection. 409 * 410 * Context: 411 * - Function called in IRQ context from ISM device driver IRQ handler. 412 */ 413 void smcd_handle_irq(struct smcd_dev *smcd, unsigned int dmbno) 414 { 415 struct smc_connection *conn = NULL; 416 unsigned long flags; 417 418 spin_lock_irqsave(&smcd->lock, flags); 419 conn = smcd->conn[dmbno]; 420 if (conn && !conn->killed) 421 tasklet_schedule(&conn->rx_tsklet); 422 spin_unlock_irqrestore(&smcd->lock, flags); 423 } 424 EXPORT_SYMBOL_GPL(smcd_handle_irq); 425 426 void __init smc_ism_init(void) 427 { 428 smc_ism_v2_capable = false; 429 } 430