net/smc/smc_ism.c

   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 #include "smc_netlink.h"
  19
  20 struct smcd_dev_list smcd_dev_list = {
  21         .list = LIST_HEAD_INIT(smcd_dev_list.list),
  22         .mutex = __MUTEX_INITIALIZER(smcd_dev_list.mutex)
  23 };
  24
  25 static bool smc_ism_v2_capable;
  26
  27 /* Test if an ISM communication is possible - same CPC */
  28 int smc_ism_cantalk(u64 peer_gid, unsigned short vlan_id, struct smcd_dev *smcd)
  29 {
  30         return smcd->ops->query_remote_gid(smcd, peer_gid, vlan_id ? 1 : 0,
  31                                            vlan_id);
  32 }
  33
  34 int smc_ism_write(struct smcd_dev *smcd, const struct smc_ism_position *pos,
  35                   void *data, size_t len)
  36 {
  37         int rc;
  38
  39         rc = smcd->ops->move_data(smcd, pos->token, pos->index, pos->signal,
  40                                   pos->offset, data, len);
  41
  42         return rc < 0 ? rc : 0;
  43 }
  44
  45 void smc_ism_get_system_eid(struct smcd_dev *smcd, u8 **eid)
  46 {
  47         smcd->ops->get_system_eid(smcd, eid);
  48 }
  49
  50 u16 smc_ism_get_chid(struct smcd_dev *smcd)
  51 {
  52         return smcd->ops->get_chid(smcd);
  53 }
  54
  55 /* HW supports ISM V2 and thus System EID is defined */
  56 bool smc_ism_is_v2_capable(void)
  57 {
  58         return smc_ism_v2_capable;
  59 }
  60
  61 /* Set a connection using this DMBE. */
  62 void smc_ism_set_conn(struct smc_connection *conn)
  63 {
  64         unsigned long flags;
  65
  66         spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
  67         conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = conn;
  68         spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
  69 }
  70
  71 /* Unset a connection using this DMBE. */
  72 void smc_ism_unset_conn(struct smc_connection *conn)
  73 {
  74         unsigned long flags;
  75
  76         if (!conn->rmb_desc)
  77                 return;
  78
  79         spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
  80         conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = NULL;
  81         spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
  82 }
  83
  84 /* Register a VLAN identifier with the ISM device. Use a reference count
  85  * and add a VLAN identifier only when the first DMB using this VLAN is
  86  * registered.
  87  */
  88 int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid)
  89 {
  90         struct smc_ism_vlanid *new_vlan, *vlan;
  91         unsigned long flags;
  92         int rc = 0;
  93
  94         if (!vlanid)                    /* No valid vlan id */
  95                 return -EINVAL;
  96
  97         /* create new vlan entry, in case we need it */
  98         new_vlan = kzalloc(sizeof(*new_vlan), GFP_KERNEL);
  99         if (!new_vlan)
 100                 return -ENOMEM;
 101         new_vlan->vlanid = vlanid;
 102         refcount_set(&new_vlan->refcnt, 1);
 103
 104         /* if there is an existing entry, increase count and return */
 105         spin_lock_irqsave(&smcd->lock, flags);
 106         list_for_each_entry(vlan, &smcd->vlan, list) {
 107                 if (vlan->vlanid == vlanid) {
 108                         refcount_inc(&vlan->refcnt);
 109                         kfree(new_vlan);
 110                         goto out;
 111                 }
 112         }
 113
 114         /* no existing entry found.
 115          * add new entry to device; might fail, e.g., if HW limit reached
 116          */
 117         if (smcd->ops->add_vlan_id(smcd, vlanid)) {
 118                 kfree(new_vlan);
 119                 rc = -EIO;
 120                 goto out;
 121         }
 122         list_add_tail(&new_vlan->list, &smcd->vlan);
 123 out:
 124         spin_unlock_irqrestore(&smcd->lock, flags);
 125         return rc;
 126 }
 127
 128 /* Unregister a VLAN identifier with the ISM device. Use a reference count
 129  * and remove a VLAN identifier only when the last DMB using this VLAN is
 130  * unregistered.
 131  */
 132 int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)
 133 {
 134         struct smc_ism_vlanid *vlan;
 135         unsigned long flags;
 136         bool found = false;
 137         int rc = 0;
 138
 139         if (!vlanid)                    /* No valid vlan id */
 140                 return -EINVAL;
 141
 142         spin_lock_irqsave(&smcd->lock, flags);
 143         list_for_each_entry(vlan, &smcd->vlan, list) {
 144                 if (vlan->vlanid == vlanid) {
 145                         if (!refcount_dec_and_test(&vlan->refcnt))
 146                                 goto out;
 147                         found = true;
 148                         break;
 149                 }
 150         }
 151         if (!found) {
 152                 rc = -ENOENT;
 153                 goto out;               /* VLAN id not in table */
 154         }
 155
 156         /* Found and the last reference just gone */
 157         if (smcd->ops->del_vlan_id(smcd, vlanid))
 158                 rc = -EIO;
 159         list_del(&vlan->list);
 160         kfree(vlan);
 161 out:
 162         spin_unlock_irqrestore(&smcd->lock, flags);
 163         return rc;
 164 }
 165
 166 int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
 167 {
 168         struct smcd_dmb dmb;
 169         int rc = 0;
 170
 171         if (!dmb_desc->dma_addr)
 172                 return rc;
 173
 174         memset(&dmb, 0, sizeof(dmb));
 175         dmb.dmb_tok = dmb_desc->token;
 176         dmb.sba_idx = dmb_desc->sba_idx;
 177         dmb.cpu_addr = dmb_desc->cpu_addr;
 178         dmb.dma_addr = dmb_desc->dma_addr;
 179         dmb.dmb_len = dmb_desc->len;
 180         rc = smcd->ops->unregister_dmb(smcd, &dmb);
 181         if (!rc || rc == ISM_ERROR) {
 182                 dmb_desc->cpu_addr = NULL;
 183                 dmb_desc->dma_addr = 0;
 184         }
 185
 186         return rc;
 187 }
 188
 189 int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
 190                          struct smc_buf_desc *dmb_desc)
 191 {
 192         struct smcd_dmb dmb;
 193         int rc;
 194
 195         memset(&dmb, 0, sizeof(dmb));
 196         dmb.dmb_len = dmb_len;
 197         dmb.sba_idx = dmb_desc->sba_idx;
 198         dmb.vlan_id = lgr->vlan_id;
 199         dmb.rgid = lgr->peer_gid;
 200         rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb);
 201         if (!rc) {
 202                 dmb_desc->sba_idx = dmb.sba_idx;
 203                 dmb_desc->token = dmb.dmb_tok;
 204                 dmb_desc->cpu_addr = dmb.cpu_addr;
 205                 dmb_desc->dma_addr = dmb.dma_addr;
 206                 dmb_desc->len = dmb.dmb_len;
 207         }
 208         return rc;
 209 }
 210
 211 static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd,
 212                                   struct sk_buff *skb,
 213                                   struct netlink_callback *cb)
 214 {
 215         char smc_pnet[SMC_MAX_PNETID_LEN + 1];
 216         struct smc_pci_dev smc_pci_dev;
 217         struct nlattr *port_attrs;
 218         struct nlattr *attrs;
 219         int use_cnt = 0;
 220         void *nlh;
 221
 222         nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 223                           &smc_gen_nl_family, NLM_F_MULTI,
 224                           SMC_NETLINK_GET_DEV_SMCD);
 225         if (!nlh)
 226                 goto errmsg;
 227         attrs = nla_nest_start(skb, SMC_GEN_DEV_SMCD);
 228         if (!attrs)
 229                 goto errout;
 230         use_cnt = atomic_read(&smcd->lgr_cnt);
 231         if (nla_put_u32(skb, SMC_NLA_DEV_USE_CNT, use_cnt))
 232                 goto errattr;
 233         if (nla_put_u8(skb, SMC_NLA_DEV_IS_CRIT, use_cnt > 0))
 234                 goto errattr;
 235         memset(&smc_pci_dev, 0, sizeof(smc_pci_dev));
 236         smc_set_pci_values(to_pci_dev(smcd->dev.parent), &smc_pci_dev);
 237         if (nla_put_u32(skb, SMC_NLA_DEV_PCI_FID, smc_pci_dev.pci_fid))
 238                 goto errattr;
 239         if (nla_put_u16(skb, SMC_NLA_DEV_PCI_CHID, smc_pci_dev.pci_pchid))
 240                 goto errattr;
 241         if (nla_put_u16(skb, SMC_NLA_DEV_PCI_VENDOR, smc_pci_dev.pci_vendor))
 242                 goto errattr;
 243         if (nla_put_u16(skb, SMC_NLA_DEV_PCI_DEVICE, smc_pci_dev.pci_device))
 244                 goto errattr;
 245         if (nla_put_string(skb, SMC_NLA_DEV_PCI_ID, smc_pci_dev.pci_id))
 246                 goto errattr;
 247
 248         port_attrs = nla_nest_start(skb, SMC_NLA_DEV_PORT);
 249         if (!port_attrs)
 250                 goto errattr;
 251         if (nla_put_u8(skb, SMC_NLA_DEV_PORT_PNET_USR, smcd->pnetid_by_user))
 252                 goto errportattr;
 253         snprintf(smc_pnet, sizeof(smc_pnet), "%s", smcd->pnetid);
 254         if (nla_put_string(skb, SMC_NLA_DEV_PORT_PNETID, smc_pnet))
 255                 goto errportattr;
 256
 257         nla_nest_end(skb, port_attrs);
 258         nla_nest_end(skb, attrs);
 259         genlmsg_end(skb, nlh);
 260         return 0;
 261
 262 errportattr:
 263         nla_nest_cancel(skb, port_attrs);
 264 errattr:
 265         nla_nest_cancel(skb, attrs);
 266 errout:
 267         nlmsg_cancel(skb, nlh);
 268 errmsg:
 269         return -EMSGSIZE;
 270 }
 271
 272 static void smc_nl_prep_smcd_dev(struct smcd_dev_list *dev_list,
 273                                  struct sk_buff *skb,
 274                                  struct netlink_callback *cb)
 275 {
 276         struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
 277         int snum = cb_ctx->pos[0];
 278         struct smcd_dev *smcd;
 279         int num = 0;
 280
 281         mutex_lock(&dev_list->mutex);
 282         list_for_each_entry(smcd, &dev_list->list, list) {
 283                 if (num < snum)
 284                         goto next;
 285                 if (smc_nl_handle_smcd_dev(smcd, skb, cb))
 286                         goto errout;
 287 next:
 288                 num++;
 289         }
 290 errout:
 291         mutex_unlock(&dev_list->mutex);
 292         cb_ctx->pos[0] = num;
 293 }
 294
 295 int smcd_nl_get_device(struct sk_buff *skb, struct netlink_callback *cb)
 296 {
 297         smc_nl_prep_smcd_dev(&smcd_dev_list, skb, cb);
 298         return skb->len;
 299 }
 300
 301 struct smc_ism_event_work {
 302         struct work_struct work;
 303         struct smcd_dev *smcd;
 304         struct smcd_event event;
 305 };
 306
 307 #define ISM_EVENT_REQUEST               0x0001
 308 #define ISM_EVENT_RESPONSE              0x0002
 309 #define ISM_EVENT_REQUEST_IR            0x00000001
 310 #define ISM_EVENT_CODE_SHUTDOWN         0x80
 311 #define ISM_EVENT_CODE_TESTLINK         0x83
 312
 313 union smcd_sw_event_info {
 314         u64     info;
 315         struct {
 316                 u8              uid[SMC_LGR_ID_SIZE];
 317                 unsigned short  vlan_id;
 318                 u16             code;
 319         };
 320 };
 321
 322 static void smcd_handle_sw_event(struct smc_ism_event_work *wrk)
 323 {
 324         union smcd_sw_event_info ev_info;
 325
 326         ev_info.info = wrk->event.info;
 327         switch (wrk->event.code) {
 328         case ISM_EVENT_CODE_SHUTDOWN:   /* Peer shut down DMBs */
 329                 smc_smcd_terminate(wrk->smcd, wrk->event.tok, ev_info.vlan_id);
 330                 break;
 331         case ISM_EVENT_CODE_TESTLINK:   /* Activity timer */
 332                 if (ev_info.code == ISM_EVENT_REQUEST) {
 333                         ev_info.code = ISM_EVENT_RESPONSE;
 334                         wrk->smcd->ops->signal_event(wrk->smcd,
 335                                                      wrk->event.tok,
 336                                                      ISM_EVENT_REQUEST_IR,
 337                                                      ISM_EVENT_CODE_TESTLINK,
 338                                                      ev_info.info);
 339                         }
 340                 break;
 341         }
 342 }
 343
 344 int smc_ism_signal_shutdown(struct smc_link_group *lgr)
 345 {
 346         int rc;
 347         union smcd_sw_event_info ev_info;
 348
 349         if (lgr->peer_shutdown)
 350                 return 0;
 351
 352         memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE);
 353         ev_info.vlan_id = lgr->vlan_id;
 354         ev_info.code = ISM_EVENT_REQUEST;
 355         rc = lgr->smcd->ops->signal_event(lgr->smcd, lgr->peer_gid,
 356                                           ISM_EVENT_REQUEST_IR,
 357                                           ISM_EVENT_CODE_SHUTDOWN,
 358                                           ev_info.info);
 359         return rc;
 360 }
 361
 362 /* worker for SMC-D events */
 363 static void smc_ism_event_work(struct work_struct *work)
 364 {
 365         struct smc_ism_event_work *wrk =
 366                 container_of(work, struct smc_ism_event_work, work);
 367
 368         switch (wrk->event.type) {
 369         case ISM_EVENT_GID:     /* GID event, token is peer GID */
 370                 smc_smcd_terminate(wrk->smcd, wrk->event.tok, VLAN_VID_MASK);
 371                 break;
 372         case ISM_EVENT_DMB:
 373                 break;
 374         case ISM_EVENT_SWR:     /* Software defined event */
 375                 smcd_handle_sw_event(wrk);
 376                 break;
 377         }
 378         kfree(wrk);
 379 }
 380
 381 static void smcd_release(struct device *dev)
 382 {
 383         struct smcd_dev *smcd = container_of(dev, struct smcd_dev, dev);
 384
 385         kfree(smcd->conn);
 386         kfree(smcd);
 387 }
 388
 389 struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name,
 390                                 const struct smcd_ops *ops, int max_dmbs)
 391 {
 392         struct smcd_dev *smcd;
 393
 394         smcd = kzalloc(sizeof(*smcd), GFP_KERNEL);
 395         if (!smcd)
 396                 return NULL;
 397         smcd->conn = kcalloc(max_dmbs, sizeof(struct smc_connection *),
 398                              GFP_KERNEL);
 399         if (!smcd->conn) {
 400                 kfree(smcd);
 401                 return NULL;
 402         }
 403
 404         smcd->dev.parent = parent;
 405         smcd->dev.release = smcd_release;
 406         device_initialize(&smcd->dev);
 407         dev_set_name(&smcd->dev, name);
 408         smcd->ops = ops;
 409         if (smc_pnetid_by_dev_port(parent, 0, smcd->pnetid))
 410                 smc_pnetid_by_table_smcd(smcd);
 411
 412         spin_lock_init(&smcd->lock);
 413         spin_lock_init(&smcd->lgr_lock);
 414         INIT_LIST_HEAD(&smcd->vlan);
 415         INIT_LIST_HEAD(&smcd->lgr_list);
 416         init_waitqueue_head(&smcd->lgrs_deleted);
 417         smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)",
 418                                                  WQ_MEM_RECLAIM, name);
 419         if (!smcd->event_wq) {
 420                 kfree(smcd->conn);
 421                 kfree(smcd);
 422                 return NULL;
 423         }
 424         return smcd;
 425 }
 426 EXPORT_SYMBOL_GPL(smcd_alloc_dev);
 427
 428 int smcd_register_dev(struct smcd_dev *smcd)
 429 {
 430         mutex_lock(&smcd_dev_list.mutex);
 431         if (list_empty(&smcd_dev_list.list)) {
 432                 u8 *system_eid = NULL;
 433
 434                 smc_ism_get_system_eid(smcd, &system_eid);
 435                 if (system_eid[24] != '0' || system_eid[28] != '0')
 436                         smc_ism_v2_capable = true;
 437         }
 438         /* sort list: devices without pnetid before devices with pnetid */
 439         if (smcd->pnetid[0])
 440                 list_add_tail(&smcd->list, &smcd_dev_list.list);
 441         else
 442                 list_add(&smcd->list, &smcd_dev_list.list);
 443         mutex_unlock(&smcd_dev_list.mutex);
 444
 445         pr_warn_ratelimited("smc: adding smcd device %s with pnetid %.16s%s\n",
 446                             dev_name(&smcd->dev), smcd->pnetid,
 447                             smcd->pnetid_by_user ? " (user defined)" : "");
 448
 449         return device_add(&smcd->dev);
 450 }
 451 EXPORT_SYMBOL_GPL(smcd_register_dev);
 452
 453 void smcd_unregister_dev(struct smcd_dev *smcd)
 454 {
 455         pr_warn_ratelimited("smc: removing smcd device %s\n",
 456                             dev_name(&smcd->dev));
 457         mutex_lock(&smcd_dev_list.mutex);
 458         list_del_init(&smcd->list);
 459         mutex_unlock(&smcd_dev_list.mutex);
 460         smcd->going_away = 1;
 461         smc_smcd_terminate_all(smcd);
 462         flush_workqueue(smcd->event_wq);
 463         destroy_workqueue(smcd->event_wq);
 464
 465         device_del(&smcd->dev);
 466 }
 467 EXPORT_SYMBOL_GPL(smcd_unregister_dev);
 468
 469 void smcd_free_dev(struct smcd_dev *smcd)
 470 {
 471         put_device(&smcd->dev);
 472 }
 473 EXPORT_SYMBOL_GPL(smcd_free_dev);
 474
 475 /* SMCD Device event handler. Called from ISM device interrupt handler.
 476  * Parameters are smcd device pointer,
 477  * - event->type (0 --> DMB, 1 --> GID),
 478  * - event->code (event code),
 479  * - event->tok (either DMB token when event type 0, or GID when event type 1)
 480  * - event->time (time of day)
 481  * - event->info (debug info).
 482  *
 483  * Context:
 484  * - Function called in IRQ context from ISM device driver event handler.
 485  */
 486 void smcd_handle_event(struct smcd_dev *smcd, struct smcd_event *event)
 487 {
 488         struct smc_ism_event_work *wrk;
 489
 490         if (smcd->going_away)
 491                 return;
 492         /* copy event to event work queue, and let it be handled there */
 493         wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
 494         if (!wrk)
 495                 return;
 496         INIT_WORK(&wrk->work, smc_ism_event_work);
 497         wrk->smcd = smcd;
 498         wrk->event = *event;
 499         queue_work(smcd->event_wq, &wrk->work);
 500 }
 501 EXPORT_SYMBOL_GPL(smcd_handle_event);
 502
 503 /* SMCD Device interrupt handler. Called from ISM device interrupt handler.
 504  * Parameters are smcd device pointer and DMB number. Find the connection and
 505  * schedule the tasklet for this connection.
 506  *
 507  * Context:
 508  * - Function called in IRQ context from ISM device driver IRQ handler.
 509  */
 510 void smcd_handle_irq(struct smcd_dev *smcd, unsigned int dmbno)
 511 {
 512         struct smc_connection *conn = NULL;
 513         unsigned long flags;
 514
 515         spin_lock_irqsave(&smcd->lock, flags);
 516         conn = smcd->conn[dmbno];
 517         if (conn && !conn->killed)
 518                 tasklet_schedule(&conn->rx_tsklet);
 519         spin_unlock_irqrestore(&smcd->lock, flags);
 520 }
 521 EXPORT_SYMBOL_GPL(smcd_handle_irq);
 522
 523 void __init smc_ism_init(void)
 524 {
 525         smc_ism_v2_capable = false;
 526 }