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