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/slab.h> 11 #include <asm/page.h> 12 13 #include "smc.h" 14 #include "smc_core.h" 15 #include "smc_ism.h" 16 #include "smc_pnet.h" 17 18 struct smcd_dev_list smcd_dev_list = { 19 .list = LIST_HEAD_INIT(smcd_dev_list.list), 20 .lock = __SPIN_LOCK_UNLOCKED(smcd_dev_list.lock) 21 }; 22 23 /* Test if an ISM communication is possible. */ 24 int smc_ism_cantalk(u64 peer_gid, unsigned short vlan_id, struct smcd_dev *smcd) 25 { 26 return smcd->ops->query_remote_gid(smcd, peer_gid, vlan_id ? 1 : 0, 27 vlan_id); 28 } 29 30 int smc_ism_write(struct smcd_dev *smcd, const struct smc_ism_position *pos, 31 void *data, size_t len) 32 { 33 int rc; 34 35 rc = smcd->ops->move_data(smcd, pos->token, pos->index, pos->signal, 36 pos->offset, data, len); 37 38 return rc < 0 ? rc : 0; 39 } 40 41 /* Set a connection using this DMBE. */ 42 void smc_ism_set_conn(struct smc_connection *conn) 43 { 44 unsigned long flags; 45 46 spin_lock_irqsave(&conn->lgr->smcd->lock, flags); 47 conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = conn; 48 spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags); 49 } 50 51 /* Unset a connection using this DMBE. */ 52 void smc_ism_unset_conn(struct smc_connection *conn) 53 { 54 unsigned long flags; 55 56 if (!conn->rmb_desc) 57 return; 58 59 spin_lock_irqsave(&conn->lgr->smcd->lock, flags); 60 conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = NULL; 61 spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags); 62 } 63 64 /* Register a VLAN identifier with the ISM device. Use a reference count 65 * and add a VLAN identifier only when the first DMB using this VLAN is 66 * registered. 67 */ 68 int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid) 69 { 70 struct smc_ism_vlanid *new_vlan, *vlan; 71 unsigned long flags; 72 int rc = 0; 73 74 if (!vlanid) /* No valid vlan id */ 75 return -EINVAL; 76 77 /* create new vlan entry, in case we need it */ 78 new_vlan = kzalloc(sizeof(*new_vlan), GFP_KERNEL); 79 if (!new_vlan) 80 return -ENOMEM; 81 new_vlan->vlanid = vlanid; 82 refcount_set(&new_vlan->refcnt, 1); 83 84 /* if there is an existing entry, increase count and return */ 85 spin_lock_irqsave(&smcd->lock, flags); 86 list_for_each_entry(vlan, &smcd->vlan, list) { 87 if (vlan->vlanid == vlanid) { 88 refcount_inc(&vlan->refcnt); 89 kfree(new_vlan); 90 goto out; 91 } 92 } 93 94 /* no existing entry found. 95 * add new entry to device; might fail, e.g., if HW limit reached 96 */ 97 if (smcd->ops->add_vlan_id(smcd, vlanid)) { 98 kfree(new_vlan); 99 rc = -EIO; 100 goto out; 101 } 102 list_add_tail(&new_vlan->list, &smcd->vlan); 103 out: 104 spin_unlock_irqrestore(&smcd->lock, flags); 105 return rc; 106 } 107 108 /* Unregister a VLAN identifier with the ISM device. Use a reference count 109 * and remove a VLAN identifier only when the last DMB using this VLAN is 110 * unregistered. 111 */ 112 int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid) 113 { 114 struct smc_ism_vlanid *vlan; 115 unsigned long flags; 116 bool found = false; 117 int rc = 0; 118 119 if (!vlanid) /* No valid vlan id */ 120 return -EINVAL; 121 122 spin_lock_irqsave(&smcd->lock, flags); 123 list_for_each_entry(vlan, &smcd->vlan, list) { 124 if (vlan->vlanid == vlanid) { 125 if (!refcount_dec_and_test(&vlan->refcnt)) 126 goto out; 127 found = true; 128 break; 129 } 130 } 131 if (!found) { 132 rc = -ENOENT; 133 goto out; /* VLAN id not in table */ 134 } 135 136 /* Found and the last reference just gone */ 137 if (smcd->ops->del_vlan_id(smcd, vlanid)) 138 rc = -EIO; 139 list_del(&vlan->list); 140 kfree(vlan); 141 out: 142 spin_unlock_irqrestore(&smcd->lock, flags); 143 return rc; 144 } 145 146 int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc) 147 { 148 struct smcd_dmb dmb; 149 int rc = 0; 150 151 if (!dmb_desc->dma_addr) 152 return rc; 153 154 memset(&dmb, 0, sizeof(dmb)); 155 dmb.dmb_tok = dmb_desc->token; 156 dmb.sba_idx = dmb_desc->sba_idx; 157 dmb.cpu_addr = dmb_desc->cpu_addr; 158 dmb.dma_addr = dmb_desc->dma_addr; 159 dmb.dmb_len = dmb_desc->len; 160 rc = smcd->ops->unregister_dmb(smcd, &dmb); 161 if (!rc || rc == ISM_ERROR) { 162 dmb_desc->cpu_addr = NULL; 163 dmb_desc->dma_addr = 0; 164 } 165 166 return rc; 167 } 168 169 int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len, 170 struct smc_buf_desc *dmb_desc) 171 { 172 struct smcd_dmb dmb; 173 int rc; 174 175 memset(&dmb, 0, sizeof(dmb)); 176 dmb.dmb_len = dmb_len; 177 dmb.sba_idx = dmb_desc->sba_idx; 178 dmb.vlan_id = lgr->vlan_id; 179 dmb.rgid = lgr->peer_gid; 180 rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb); 181 if (!rc) { 182 dmb_desc->sba_idx = dmb.sba_idx; 183 dmb_desc->token = dmb.dmb_tok; 184 dmb_desc->cpu_addr = dmb.cpu_addr; 185 dmb_desc->dma_addr = dmb.dma_addr; 186 dmb_desc->len = dmb.dmb_len; 187 } 188 return rc; 189 } 190 191 struct smc_ism_event_work { 192 struct work_struct work; 193 struct smcd_dev *smcd; 194 struct smcd_event event; 195 }; 196 197 #define ISM_EVENT_REQUEST 0x0001 198 #define ISM_EVENT_RESPONSE 0x0002 199 #define ISM_EVENT_REQUEST_IR 0x00000001 200 #define ISM_EVENT_CODE_SHUTDOWN 0x80 201 #define ISM_EVENT_CODE_TESTLINK 0x83 202 203 union smcd_sw_event_info { 204 u64 info; 205 struct { 206 u8 uid[SMC_LGR_ID_SIZE]; 207 unsigned short vlan_id; 208 u16 code; 209 }; 210 }; 211 212 static void smcd_handle_sw_event(struct smc_ism_event_work *wrk) 213 { 214 union smcd_sw_event_info ev_info; 215 216 ev_info.info = wrk->event.info; 217 switch (wrk->event.code) { 218 case ISM_EVENT_CODE_SHUTDOWN: /* Peer shut down DMBs */ 219 smc_smcd_terminate(wrk->smcd, wrk->event.tok, ev_info.vlan_id); 220 break; 221 case ISM_EVENT_CODE_TESTLINK: /* Activity timer */ 222 if (ev_info.code == ISM_EVENT_REQUEST) { 223 ev_info.code = ISM_EVENT_RESPONSE; 224 wrk->smcd->ops->signal_event(wrk->smcd, 225 wrk->event.tok, 226 ISM_EVENT_REQUEST_IR, 227 ISM_EVENT_CODE_TESTLINK, 228 ev_info.info); 229 } 230 break; 231 } 232 } 233 234 int smc_ism_signal_shutdown(struct smc_link_group *lgr) 235 { 236 int rc; 237 union smcd_sw_event_info ev_info; 238 239 if (lgr->peer_shutdown) 240 return 0; 241 242 memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE); 243 ev_info.vlan_id = lgr->vlan_id; 244 ev_info.code = ISM_EVENT_REQUEST; 245 rc = lgr->smcd->ops->signal_event(lgr->smcd, lgr->peer_gid, 246 ISM_EVENT_REQUEST_IR, 247 ISM_EVENT_CODE_SHUTDOWN, 248 ev_info.info); 249 return rc; 250 } 251 252 /* worker for SMC-D events */ 253 static void smc_ism_event_work(struct work_struct *work) 254 { 255 struct smc_ism_event_work *wrk = 256 container_of(work, struct smc_ism_event_work, work); 257 258 switch (wrk->event.type) { 259 case ISM_EVENT_GID: /* GID event, token is peer GID */ 260 smc_smcd_terminate(wrk->smcd, wrk->event.tok, VLAN_VID_MASK); 261 break; 262 case ISM_EVENT_DMB: 263 break; 264 case ISM_EVENT_SWR: /* Software defined event */ 265 smcd_handle_sw_event(wrk); 266 break; 267 } 268 kfree(wrk); 269 } 270 271 static void smcd_release(struct device *dev) 272 { 273 struct smcd_dev *smcd = container_of(dev, struct smcd_dev, dev); 274 275 kfree(smcd->conn); 276 kfree(smcd); 277 } 278 279 struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name, 280 const struct smcd_ops *ops, int max_dmbs) 281 { 282 struct smcd_dev *smcd; 283 284 smcd = kzalloc(sizeof(*smcd), GFP_KERNEL); 285 if (!smcd) 286 return NULL; 287 smcd->conn = kcalloc(max_dmbs, sizeof(struct smc_connection *), 288 GFP_KERNEL); 289 if (!smcd->conn) { 290 kfree(smcd); 291 return NULL; 292 } 293 294 smcd->dev.parent = parent; 295 smcd->dev.release = smcd_release; 296 device_initialize(&smcd->dev); 297 dev_set_name(&smcd->dev, name); 298 smcd->ops = ops; 299 smc_pnetid_by_dev_port(parent, 0, smcd->pnetid); 300 301 spin_lock_init(&smcd->lock); 302 spin_lock_init(&smcd->lgr_lock); 303 INIT_LIST_HEAD(&smcd->vlan); 304 INIT_LIST_HEAD(&smcd->lgr_list); 305 init_waitqueue_head(&smcd->lgrs_deleted); 306 smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)", 307 WQ_MEM_RECLAIM, name); 308 if (!smcd->event_wq) { 309 kfree(smcd->conn); 310 kfree(smcd); 311 return NULL; 312 } 313 return smcd; 314 } 315 EXPORT_SYMBOL_GPL(smcd_alloc_dev); 316 317 int smcd_register_dev(struct smcd_dev *smcd) 318 { 319 spin_lock(&smcd_dev_list.lock); 320 list_add_tail(&smcd->list, &smcd_dev_list.list); 321 spin_unlock(&smcd_dev_list.lock); 322 323 return device_add(&smcd->dev); 324 } 325 EXPORT_SYMBOL_GPL(smcd_register_dev); 326 327 void smcd_unregister_dev(struct smcd_dev *smcd) 328 { 329 spin_lock(&smcd_dev_list.lock); 330 list_del_init(&smcd->list); 331 spin_unlock(&smcd_dev_list.lock); 332 smcd->going_away = 1; 333 smc_smcd_terminate_all(smcd); 334 flush_workqueue(smcd->event_wq); 335 destroy_workqueue(smcd->event_wq); 336 337 device_del(&smcd->dev); 338 } 339 EXPORT_SYMBOL_GPL(smcd_unregister_dev); 340 341 void smcd_free_dev(struct smcd_dev *smcd) 342 { 343 put_device(&smcd->dev); 344 } 345 EXPORT_SYMBOL_GPL(smcd_free_dev); 346 347 /* SMCD Device event handler. Called from ISM device interrupt handler. 348 * Parameters are smcd device pointer, 349 * - event->type (0 --> DMB, 1 --> GID), 350 * - event->code (event code), 351 * - event->tok (either DMB token when event type 0, or GID when event type 1) 352 * - event->time (time of day) 353 * - event->info (debug info). 354 * 355 * Context: 356 * - Function called in IRQ context from ISM device driver event handler. 357 */ 358 void smcd_handle_event(struct smcd_dev *smcd, struct smcd_event *event) 359 { 360 struct smc_ism_event_work *wrk; 361 362 if (smcd->going_away) 363 return; 364 /* copy event to event work queue, and let it be handled there */ 365 wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC); 366 if (!wrk) 367 return; 368 INIT_WORK(&wrk->work, smc_ism_event_work); 369 wrk->smcd = smcd; 370 wrk->event = *event; 371 queue_work(smcd->event_wq, &wrk->work); 372 } 373 EXPORT_SYMBOL_GPL(smcd_handle_event); 374 375 /* SMCD Device interrupt handler. Called from ISM device interrupt handler. 376 * Parameters are smcd device pointer and DMB number. Find the connection and 377 * schedule the tasklet for this connection. 378 * 379 * Context: 380 * - Function called in IRQ context from ISM device driver IRQ handler. 381 */ 382 void smcd_handle_irq(struct smcd_dev *smcd, unsigned int dmbno) 383 { 384 struct smc_connection *conn = NULL; 385 unsigned long flags; 386 387 spin_lock_irqsave(&smcd->lock, flags); 388 conn = smcd->conn[dmbno]; 389 if (conn && !conn->killed) 390 tasklet_schedule(&conn->rx_tsklet); 391 spin_unlock_irqrestore(&smcd->lock, flags); 392 } 393 EXPORT_SYMBOL_GPL(smcd_handle_irq); 394