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; 149 150 memset(&dmb, 0, sizeof(dmb)); 151 dmb.dmb_tok = dmb_desc->token; 152 dmb.sba_idx = dmb_desc->sba_idx; 153 dmb.cpu_addr = dmb_desc->cpu_addr; 154 dmb.dma_addr = dmb_desc->dma_addr; 155 dmb.dmb_len = dmb_desc->len; 156 return smcd->ops->unregister_dmb(smcd, &dmb); 157 } 158 159 int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len, 160 struct smc_buf_desc *dmb_desc) 161 { 162 struct smcd_dmb dmb; 163 int rc; 164 165 memset(&dmb, 0, sizeof(dmb)); 166 dmb.dmb_len = dmb_len; 167 dmb.sba_idx = dmb_desc->sba_idx; 168 dmb.vlan_id = lgr->vlan_id; 169 dmb.rgid = lgr->peer_gid; 170 rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb); 171 if (!rc) { 172 dmb_desc->sba_idx = dmb.sba_idx; 173 dmb_desc->token = dmb.dmb_tok; 174 dmb_desc->cpu_addr = dmb.cpu_addr; 175 dmb_desc->dma_addr = dmb.dma_addr; 176 dmb_desc->len = dmb.dmb_len; 177 } 178 return rc; 179 } 180 181 struct smc_ism_event_work { 182 struct work_struct work; 183 struct smcd_dev *smcd; 184 struct smcd_event event; 185 }; 186 187 #define ISM_EVENT_REQUEST 0x0001 188 #define ISM_EVENT_RESPONSE 0x0002 189 #define ISM_EVENT_REQUEST_IR 0x00000001 190 #define ISM_EVENT_CODE_SHUTDOWN 0x80 191 #define ISM_EVENT_CODE_TESTLINK 0x83 192 193 union smcd_sw_event_info { 194 u64 info; 195 struct { 196 u8 uid[SMC_LGR_ID_SIZE]; 197 unsigned short vlan_id; 198 u16 code; 199 }; 200 }; 201 202 static void smcd_handle_sw_event(struct smc_ism_event_work *wrk) 203 { 204 union smcd_sw_event_info ev_info; 205 206 ev_info.info = wrk->event.info; 207 switch (wrk->event.code) { 208 case ISM_EVENT_CODE_SHUTDOWN: /* Peer shut down DMBs */ 209 smc_smcd_terminate(wrk->smcd, wrk->event.tok, ev_info.vlan_id); 210 break; 211 case ISM_EVENT_CODE_TESTLINK: /* Activity timer */ 212 if (ev_info.code == ISM_EVENT_REQUEST) { 213 ev_info.code = ISM_EVENT_RESPONSE; 214 wrk->smcd->ops->signal_event(wrk->smcd, 215 wrk->event.tok, 216 ISM_EVENT_REQUEST_IR, 217 ISM_EVENT_CODE_TESTLINK, 218 ev_info.info); 219 } 220 break; 221 } 222 } 223 224 int smc_ism_signal_shutdown(struct smc_link_group *lgr) 225 { 226 int rc; 227 union smcd_sw_event_info ev_info; 228 229 memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE); 230 ev_info.vlan_id = lgr->vlan_id; 231 ev_info.code = ISM_EVENT_REQUEST; 232 rc = lgr->smcd->ops->signal_event(lgr->smcd, lgr->peer_gid, 233 ISM_EVENT_REQUEST_IR, 234 ISM_EVENT_CODE_SHUTDOWN, 235 ev_info.info); 236 return rc; 237 } 238 239 /* worker for SMC-D events */ 240 static void smc_ism_event_work(struct work_struct *work) 241 { 242 struct smc_ism_event_work *wrk = 243 container_of(work, struct smc_ism_event_work, work); 244 245 switch (wrk->event.type) { 246 case ISM_EVENT_GID: /* GID event, token is peer GID */ 247 smc_smcd_terminate(wrk->smcd, wrk->event.tok, VLAN_VID_MASK); 248 break; 249 case ISM_EVENT_DMB: 250 break; 251 case ISM_EVENT_SWR: /* Software defined event */ 252 smcd_handle_sw_event(wrk); 253 break; 254 } 255 kfree(wrk); 256 } 257 258 static void smcd_release(struct device *dev) 259 { 260 struct smcd_dev *smcd = container_of(dev, struct smcd_dev, dev); 261 262 kfree(smcd->conn); 263 kfree(smcd); 264 } 265 266 struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name, 267 const struct smcd_ops *ops, int max_dmbs) 268 { 269 struct smcd_dev *smcd; 270 271 smcd = kzalloc(sizeof(*smcd), GFP_KERNEL); 272 if (!smcd) 273 return NULL; 274 smcd->conn = kcalloc(max_dmbs, sizeof(struct smc_connection *), 275 GFP_KERNEL); 276 if (!smcd->conn) { 277 kfree(smcd); 278 return NULL; 279 } 280 281 smcd->dev.parent = parent; 282 smcd->dev.release = smcd_release; 283 device_initialize(&smcd->dev); 284 dev_set_name(&smcd->dev, name); 285 smcd->ops = ops; 286 smc_pnetid_by_dev_port(parent, 0, smcd->pnetid); 287 288 spin_lock_init(&smcd->lock); 289 INIT_LIST_HEAD(&smcd->vlan); 290 smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)", 291 WQ_MEM_RECLAIM, name); 292 if (!smcd->event_wq) { 293 kfree(smcd->conn); 294 kfree(smcd); 295 return NULL; 296 } 297 return smcd; 298 } 299 EXPORT_SYMBOL_GPL(smcd_alloc_dev); 300 301 int smcd_register_dev(struct smcd_dev *smcd) 302 { 303 spin_lock(&smcd_dev_list.lock); 304 list_add_tail(&smcd->list, &smcd_dev_list.list); 305 spin_unlock(&smcd_dev_list.lock); 306 307 return device_add(&smcd->dev); 308 } 309 EXPORT_SYMBOL_GPL(smcd_register_dev); 310 311 void smcd_unregister_dev(struct smcd_dev *smcd) 312 { 313 spin_lock(&smcd_dev_list.lock); 314 list_del(&smcd->list); 315 spin_unlock(&smcd_dev_list.lock); 316 flush_workqueue(smcd->event_wq); 317 destroy_workqueue(smcd->event_wq); 318 smc_smcd_terminate(smcd, 0, VLAN_VID_MASK); 319 320 device_del(&smcd->dev); 321 } 322 EXPORT_SYMBOL_GPL(smcd_unregister_dev); 323 324 void smcd_free_dev(struct smcd_dev *smcd) 325 { 326 put_device(&smcd->dev); 327 } 328 EXPORT_SYMBOL_GPL(smcd_free_dev); 329 330 /* SMCD Device event handler. Called from ISM device interrupt handler. 331 * Parameters are smcd device pointer, 332 * - event->type (0 --> DMB, 1 --> GID), 333 * - event->code (event code), 334 * - event->tok (either DMB token when event type 0, or GID when event type 1) 335 * - event->time (time of day) 336 * - event->info (debug info). 337 * 338 * Context: 339 * - Function called in IRQ context from ISM device driver event handler. 340 */ 341 void smcd_handle_event(struct smcd_dev *smcd, struct smcd_event *event) 342 { 343 struct smc_ism_event_work *wrk; 344 345 /* copy event to event work queue, and let it be handled there */ 346 wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC); 347 if (!wrk) 348 return; 349 INIT_WORK(&wrk->work, smc_ism_event_work); 350 wrk->smcd = smcd; 351 wrk->event = *event; 352 queue_work(smcd->event_wq, &wrk->work); 353 } 354 EXPORT_SYMBOL_GPL(smcd_handle_event); 355 356 /* SMCD Device interrupt handler. Called from ISM device interrupt handler. 357 * Parameters are smcd device pointer and DMB number. Find the connection and 358 * schedule the tasklet for this connection. 359 * 360 * Context: 361 * - Function called in IRQ context from ISM device driver IRQ handler. 362 */ 363 void smcd_handle_irq(struct smcd_dev *smcd, unsigned int dmbno) 364 { 365 struct smc_connection *conn = NULL; 366 unsigned long flags; 367 368 spin_lock_irqsave(&smcd->lock, flags); 369 conn = smcd->conn[dmbno]; 370 if (conn) 371 tasklet_schedule(&conn->rx_tsklet); 372 spin_unlock_irqrestore(&smcd->lock, flags); 373 } 374 EXPORT_SYMBOL_GPL(smcd_handle_irq); 375