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 /* worker for SMC-D events */ 188 static void smc_ism_event_work(struct work_struct *work) 189 { 190 struct smc_ism_event_work *wrk = 191 container_of(work, struct smc_ism_event_work, work); 192 193 switch (wrk->event.type) { 194 case ISM_EVENT_GID: /* GID event, token is peer GID */ 195 smc_smcd_terminate(wrk->smcd, wrk->event.tok); 196 break; 197 case ISM_EVENT_DMB: 198 break; 199 } 200 kfree(wrk); 201 } 202 203 static void smcd_release(struct device *dev) 204 { 205 struct smcd_dev *smcd = container_of(dev, struct smcd_dev, dev); 206 207 kfree(smcd->conn); 208 kfree(smcd); 209 } 210 211 struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name, 212 const struct smcd_ops *ops, int max_dmbs) 213 { 214 struct smcd_dev *smcd; 215 216 smcd = kzalloc(sizeof(*smcd), GFP_KERNEL); 217 if (!smcd) 218 return NULL; 219 smcd->conn = kcalloc(max_dmbs, sizeof(struct smc_connection *), 220 GFP_KERNEL); 221 if (!smcd->conn) { 222 kfree(smcd); 223 return NULL; 224 } 225 226 smcd->dev.parent = parent; 227 smcd->dev.release = smcd_release; 228 device_initialize(&smcd->dev); 229 dev_set_name(&smcd->dev, name); 230 smcd->ops = ops; 231 smc_pnetid_by_dev_port(parent, 0, smcd->pnetid); 232 233 spin_lock_init(&smcd->lock); 234 INIT_LIST_HEAD(&smcd->vlan); 235 smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)", 236 WQ_MEM_RECLAIM, name); 237 return smcd; 238 } 239 EXPORT_SYMBOL_GPL(smcd_alloc_dev); 240 241 int smcd_register_dev(struct smcd_dev *smcd) 242 { 243 spin_lock(&smcd_dev_list.lock); 244 list_add_tail(&smcd->list, &smcd_dev_list.list); 245 spin_unlock(&smcd_dev_list.lock); 246 247 return device_add(&smcd->dev); 248 } 249 EXPORT_SYMBOL_GPL(smcd_register_dev); 250 251 void smcd_unregister_dev(struct smcd_dev *smcd) 252 { 253 spin_lock(&smcd_dev_list.lock); 254 list_del(&smcd->list); 255 spin_unlock(&smcd_dev_list.lock); 256 flush_workqueue(smcd->event_wq); 257 destroy_workqueue(smcd->event_wq); 258 smc_smcd_terminate(smcd, 0); 259 260 device_del(&smcd->dev); 261 } 262 EXPORT_SYMBOL_GPL(smcd_unregister_dev); 263 264 void smcd_free_dev(struct smcd_dev *smcd) 265 { 266 put_device(&smcd->dev); 267 } 268 EXPORT_SYMBOL_GPL(smcd_free_dev); 269 270 /* SMCD Device event handler. Called from ISM device interrupt handler. 271 * Parameters are smcd device pointer, 272 * - event->type (0 --> DMB, 1 --> GID), 273 * - event->code (event code), 274 * - event->tok (either DMB token when event type 0, or GID when event type 1) 275 * - event->time (time of day) 276 * - event->info (debug info). 277 * 278 * Context: 279 * - Function called in IRQ context from ISM device driver event handler. 280 */ 281 void smcd_handle_event(struct smcd_dev *smcd, struct smcd_event *event) 282 { 283 struct smc_ism_event_work *wrk; 284 285 /* copy event to event work queue, and let it be handled there */ 286 wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC); 287 if (!wrk) 288 return; 289 INIT_WORK(&wrk->work, smc_ism_event_work); 290 wrk->smcd = smcd; 291 wrk->event = *event; 292 queue_work(smcd->event_wq, &wrk->work); 293 } 294 EXPORT_SYMBOL_GPL(smcd_handle_event); 295 296 /* SMCD Device interrupt handler. Called from ISM device interrupt handler. 297 * Parameters are smcd device pointer and DMB number. Find the connection and 298 * schedule the tasklet for this connection. 299 * 300 * Context: 301 * - Function called in IRQ context from ISM device driver IRQ handler. 302 */ 303 void smcd_handle_irq(struct smcd_dev *smcd, unsigned int dmbno) 304 { 305 struct smc_connection *conn = NULL; 306 unsigned long flags; 307 308 spin_lock_irqsave(&smcd->lock, flags); 309 conn = smcd->conn[dmbno]; 310 if (conn) 311 tasklet_schedule(&conn->rx_tsklet); 312 spin_unlock_irqrestore(&smcd->lock, flags); 313 } 314 EXPORT_SYMBOL_GPL(smcd_handle_irq); 315