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/if_vlan.h>
  10 #include <linux/spinlock.h>
  11 #include <linux/mutex.h>
  12 #include <linux/slab.h>
  13 #include <asm/page.h>
  14
  15 #include "smc.h"
  16 #include "smc_core.h"
  17 #include "smc_ism.h"
  18 #include "smc_pnet.h"
  19 #include "smc_netlink.h"
  20
  21 struct smcd_dev_list smcd_dev_list = {
  22         .list = LIST_HEAD_INIT(smcd_dev_list.list),
  23         .mutex = __MUTEX_INITIALIZER(smcd_dev_list.mutex)
  24 };
  25
  26 static bool smc_ism_v2_capable;
  27 static u8 smc_ism_v2_system_eid[SMC_MAX_EID_LEN];
  28
  29 /* Test if an ISM communication is possible - same CPC */
  30 int smc_ism_cantalk(u64 peer_gid, unsigned short vlan_id, struct smcd_dev *smcd)
  31 {
  32         return smcd->ops->query_remote_gid(smcd, peer_gid, vlan_id ? 1 : 0,
  33                                            vlan_id);
  34 }
  35
  36 int smc_ism_write(struct smcd_dev *smcd, const struct smc_ism_position *pos,
  37                   void *data, size_t len)
  38 {
  39         int rc;
  40
  41         rc = smcd->ops->move_data(smcd, pos->token, pos->index, pos->signal,
  42                                   pos->offset, data, len);
  43
  44         return rc < 0 ? rc : 0;
  45 }
  46
  47 void smc_ism_get_system_eid(u8 **eid)
  48 {
  49         if (!smc_ism_v2_capable)
  50                 *eid = NULL;
  51         else
  52                 *eid = smc_ism_v2_system_eid;
  53 }
  54
  55 u16 smc_ism_get_chid(struct smcd_dev *smcd)
  56 {
  57         return smcd->ops->get_chid(smcd);
  58 }
  59
  60 /* HW supports ISM V2 and thus System EID is defined */
  61 bool smc_ism_is_v2_capable(void)
  62 {
  63         return smc_ism_v2_capable;
  64 }
  65
  66 /* Set a connection using this DMBE. */
  67 void smc_ism_set_conn(struct smc_connection *conn)
  68 {
  69         unsigned long flags;
  70
  71         spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
  72         conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = conn;
  73         spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
  74 }
  75
  76 /* Unset a connection using this DMBE. */
  77 void smc_ism_unset_conn(struct smc_connection *conn)
  78 {
  79         unsigned long flags;
  80
  81         if (!conn->rmb_desc)
  82                 return;
  83
  84         spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
  85         conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = NULL;
  86         spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
  87 }
  88
  89 /* Register a VLAN identifier with the ISM device. Use a reference count
  90  * and add a VLAN identifier only when the first DMB using this VLAN is
  91  * registered.
  92  */
  93 int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid)
  94 {
  95         struct smc_ism_vlanid *new_vlan, *vlan;
  96         unsigned long flags;
  97         int rc = 0;
  98
  99         if (!vlanid)                    /* No valid vlan id */
 100                 return -EINVAL;
 101
 102         /* create new vlan entry, in case we need it */
 103         new_vlan = kzalloc(sizeof(*new_vlan), GFP_KERNEL);
 104         if (!new_vlan)
 105                 return -ENOMEM;
 106         new_vlan->vlanid = vlanid;
 107         refcount_set(&new_vlan->refcnt, 1);
 108
 109         /* if there is an existing entry, increase count and return */
 110         spin_lock_irqsave(&smcd->lock, flags);
 111         list_for_each_entry(vlan, &smcd->vlan, list) {
 112                 if (vlan->vlanid == vlanid) {
 113                         refcount_inc(&vlan->refcnt);
 114                         kfree(new_vlan);
 115                         goto out;
 116                 }
 117         }
 118
 119         /* no existing entry found.
 120          * add new entry to device; might fail, e.g., if HW limit reached
 121          */
 122         if (smcd->ops->add_vlan_id(smcd, vlanid)) {
 123                 kfree(new_vlan);
 124                 rc = -EIO;
 125                 goto out;
 126         }
 127         list_add_tail(&new_vlan->list, &smcd->vlan);
 128 out:
 129         spin_unlock_irqrestore(&smcd->lock, flags);
 130         return rc;
 131 }
 132
 133 /* Unregister a VLAN identifier with the ISM device. Use a reference count
 134  * and remove a VLAN identifier only when the last DMB using this VLAN is
 135  * unregistered.
 136  */
 137 int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)
 138 {
 139         struct smc_ism_vlanid *vlan;
 140         unsigned long flags;
 141         bool found = false;
 142         int rc = 0;
 143
 144         if (!vlanid)                    /* No valid vlan id */
 145                 return -EINVAL;
 146
 147         spin_lock_irqsave(&smcd->lock, flags);
 148         list_for_each_entry(vlan, &smcd->vlan, list) {
 149                 if (vlan->vlanid == vlanid) {
 150                         if (!refcount_dec_and_test(&vlan->refcnt))
 151                                 goto out;
 152                         found = true;
 153                         break;
 154                 }
 155         }
 156         if (!found) {
 157                 rc = -ENOENT;
 158                 goto out;               /* VLAN id not in table */
 159         }
 160
 161         /* Found and the last reference just gone */
 162         if (smcd->ops->del_vlan_id(smcd, vlanid))
 163                 rc = -EIO;
 164         list_del(&vlan->list);
 165         kfree(vlan);
 166 out:
 167         spin_unlock_irqrestore(&smcd->lock, flags);
 168         return rc;
 169 }
 170
 171 int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
 172 {
 173         struct smcd_dmb dmb;
 174         int rc = 0;
 175
 176         if (!dmb_desc->dma_addr)
 177                 return rc;
 178
 179         memset(&dmb, 0, sizeof(dmb));
 180         dmb.dmb_tok = dmb_desc->token;
 181         dmb.sba_idx = dmb_desc->sba_idx;
 182         dmb.cpu_addr = dmb_desc->cpu_addr;
 183         dmb.dma_addr = dmb_desc->dma_addr;
 184         dmb.dmb_len = dmb_desc->len;
 185         rc = smcd->ops->unregister_dmb(smcd, &dmb);
 186         if (!rc || rc == ISM_ERROR) {
 187                 dmb_desc->cpu_addr = NULL;
 188                 dmb_desc->dma_addr = 0;
 189         }
 190
 191         return rc;
 192 }
 193
 194 int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
 195                          struct smc_buf_desc *dmb_desc)
 196 {
 197         struct smcd_dmb dmb;
 198         int rc;
 199
 200         memset(&dmb, 0, sizeof(dmb));
 201         dmb.dmb_len = dmb_len;
 202         dmb.sba_idx = dmb_desc->sba_idx;
 203         dmb.vlan_id = lgr->vlan_id;
 204         dmb.rgid = lgr->peer_gid;
 205         rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb);
 206         if (!rc) {
 207                 dmb_desc->sba_idx = dmb.sba_idx;
 208                 dmb_desc->token = dmb.dmb_tok;
 209                 dmb_desc->cpu_addr = dmb.cpu_addr;
 210                 dmb_desc->dma_addr = dmb.dma_addr;
 211                 dmb_desc->len = dmb.dmb_len;
 212         }
 213         return rc;
 214 }
 215
 216 static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd,
 217                                   struct sk_buff *skb,
 218                                   struct netlink_callback *cb)
 219 {
 220         char smc_pnet[SMC_MAX_PNETID_LEN + 1];
 221         struct smc_pci_dev smc_pci_dev;
 222         struct nlattr *port_attrs;
 223         struct nlattr *attrs;
 224         int use_cnt = 0;
 225         void *nlh;
 226
 227         nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 228                           &smc_gen_nl_family, NLM_F_MULTI,
 229                           SMC_NETLINK_GET_DEV_SMCD);
 230         if (!nlh)
 231                 goto errmsg;
 232         attrs = nla_nest_start(skb, SMC_GEN_DEV_SMCD);
 233         if (!attrs)
 234                 goto errout;
 235         use_cnt = atomic_read(&smcd->lgr_cnt);
 236         if (nla_put_u32(skb, SMC_NLA_DEV_USE_CNT, use_cnt))
 237                 goto errattr;
 238         if (nla_put_u8(skb, SMC_NLA_DEV_IS_CRIT, use_cnt > 0))
 239                 goto errattr;
 240         memset(&smc_pci_dev, 0, sizeof(smc_pci_dev));
 241         smc_set_pci_values(to_pci_dev(smcd->dev.parent), &smc_pci_dev);
 242         if (nla_put_u32(skb, SMC_NLA_DEV_PCI_FID, smc_pci_dev.pci_fid))
 243                 goto errattr;
 244         if (nla_put_u16(skb, SMC_NLA_DEV_PCI_CHID, smc_pci_dev.pci_pchid))
 245                 goto errattr;
 246         if (nla_put_u16(skb, SMC_NLA_DEV_PCI_VENDOR, smc_pci_dev.pci_vendor))
 247                 goto errattr;
 248         if (nla_put_u16(skb, SMC_NLA_DEV_PCI_DEVICE, smc_pci_dev.pci_device))
 249                 goto errattr;
 250         if (nla_put_string(skb, SMC_NLA_DEV_PCI_ID, smc_pci_dev.pci_id))
 251                 goto errattr;
 252
 253         port_attrs = nla_nest_start(skb, SMC_NLA_DEV_PORT);
 254         if (!port_attrs)
 255                 goto errattr;
 256         if (nla_put_u8(skb, SMC_NLA_DEV_PORT_PNET_USR, smcd->pnetid_by_user))
 257                 goto errportattr;
 258         memcpy(smc_pnet, smcd->pnetid, SMC_MAX_PNETID_LEN);
 259         smc_pnet[SMC_MAX_PNETID_LEN] = 0;
 260         if (nla_put_string(skb, SMC_NLA_DEV_PORT_PNETID, smc_pnet))
 261                 goto errportattr;
 262
 263         nla_nest_end(skb, port_attrs);
 264         nla_nest_end(skb, attrs);
 265         genlmsg_end(skb, nlh);
 266         return 0;
 267
 268 errportattr:
 269         nla_nest_cancel(skb, port_attrs);
 270 errattr:
 271         nla_nest_cancel(skb, attrs);
 272 errout:
 273         nlmsg_cancel(skb, nlh);
 274 errmsg:
 275         return -EMSGSIZE;
 276 }
 277
 278 static void smc_nl_prep_smcd_dev(struct smcd_dev_list *dev_list,
 279                                  struct sk_buff *skb,
 280                                  struct netlink_callback *cb)
 281 {
 282         struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
 283         int snum = cb_ctx->pos[0];
 284         struct smcd_dev *smcd;
 285         int num = 0;
 286
 287         mutex_lock(&dev_list->mutex);
 288         list_for_each_entry(smcd, &dev_list->list, list) {
 289                 if (num < snum)
 290                         goto next;
 291                 if (smc_nl_handle_smcd_dev(smcd, skb, cb))
 292                         goto errout;
 293 next:
 294                 num++;
 295         }
 296 errout:
 297         mutex_unlock(&dev_list->mutex);
 298         cb_ctx->pos[0] = num;
 299 }
 300
 301 int smcd_nl_get_device(struct sk_buff *skb, struct netlink_callback *cb)
 302 {
 303         smc_nl_prep_smcd_dev(&smcd_dev_list, skb, cb);
 304         return skb->len;
 305 }
 306
 307 struct smc_ism_event_work {
 308         struct work_struct work;
 309         struct smcd_dev *smcd;
 310         struct smcd_event event;
 311 };
 312
 313 #define ISM_EVENT_REQUEST               0x0001
 314 #define ISM_EVENT_RESPONSE              0x0002
 315 #define ISM_EVENT_REQUEST_IR            0x00000001
 316 #define ISM_EVENT_CODE_SHUTDOWN         0x80
 317 #define ISM_EVENT_CODE_TESTLINK         0x83
 318
 319 union smcd_sw_event_info {
 320         u64     info;
 321         struct {
 322                 u8              uid[SMC_LGR_ID_SIZE];
 323                 unsigned short  vlan_id;
 324                 u16             code;
 325         };
 326 };
 327
 328 static void smcd_handle_sw_event(struct smc_ism_event_work *wrk)
 329 {
 330         union smcd_sw_event_info ev_info;
 331
 332         ev_info.info = wrk->event.info;
 333         switch (wrk->event.code) {
 334         case ISM_EVENT_CODE_SHUTDOWN:   /* Peer shut down DMBs */
 335                 smc_smcd_terminate(wrk->smcd, wrk->event.tok, ev_info.vlan_id);
 336                 break;
 337         case ISM_EVENT_CODE_TESTLINK:   /* Activity timer */
 338                 if (ev_info.code == ISM_EVENT_REQUEST) {
 339                         ev_info.code = ISM_EVENT_RESPONSE;
 340                         wrk->smcd->ops->signal_event(wrk->smcd,
 341                                                      wrk->event.tok,
 342                                                      ISM_EVENT_REQUEST_IR,
 343                                                      ISM_EVENT_CODE_TESTLINK,
 344                                                      ev_info.info);
 345                         }
 346                 break;
 347         }
 348 }
 349
 350 int smc_ism_signal_shutdown(struct smc_link_group *lgr)
 351 {
 352         int rc;
 353         union smcd_sw_event_info ev_info;
 354
 355         if (lgr->peer_shutdown)
 356                 return 0;
 357
 358         memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE);
 359         ev_info.vlan_id = lgr->vlan_id;
 360         ev_info.code = ISM_EVENT_REQUEST;
 361         rc = lgr->smcd->ops->signal_event(lgr->smcd, lgr->peer_gid,
 362                                           ISM_EVENT_REQUEST_IR,
 363                                           ISM_EVENT_CODE_SHUTDOWN,
 364                                           ev_info.info);
 365         return rc;
 366 }
 367
 368 /* worker for SMC-D events */
 369 static void smc_ism_event_work(struct work_struct *work)
 370 {
 371         struct smc_ism_event_work *wrk =
 372                 container_of(work, struct smc_ism_event_work, work);
 373
 374         switch (wrk->event.type) {
 375         case ISM_EVENT_GID:     /* GID event, token is peer GID */
 376                 smc_smcd_terminate(wrk->smcd, wrk->event.tok, VLAN_VID_MASK);
 377                 break;
 378         case ISM_EVENT_DMB:
 379                 break;
 380         case ISM_EVENT_SWR:     /* Software defined event */
 381                 smcd_handle_sw_event(wrk);
 382                 break;
 383         }
 384         kfree(wrk);
 385 }
 386
 387 static void smcd_release(struct device *dev)
 388 {
 389         struct smcd_dev *smcd = container_of(dev, struct smcd_dev, dev);
 390
 391         kfree(smcd->conn);
 392         kfree(smcd);
 393 }
 394
 395 struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name,
 396                                 const struct smcd_ops *ops, int max_dmbs)
 397 {
 398         struct smcd_dev *smcd;
 399
 400         smcd = kzalloc(sizeof(*smcd), GFP_KERNEL);
 401         if (!smcd)
 402                 return NULL;
 403         smcd->conn = kcalloc(max_dmbs, sizeof(struct smc_connection *),
 404                              GFP_KERNEL);
 405         if (!smcd->conn) {
 406                 kfree(smcd);
 407                 return NULL;
 408         }
 409
 410         smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)",
 411                                                  WQ_MEM_RECLAIM, name);
 412         if (!smcd->event_wq) {
 413                 kfree(smcd->conn);
 414                 kfree(smcd);
 415                 return NULL;
 416         }
 417
 418         smcd->dev.parent = parent;
 419         smcd->dev.release = smcd_release;
 420         device_initialize(&smcd->dev);
 421         dev_set_name(&smcd->dev, name);
 422         smcd->ops = ops;
 423         if (smc_pnetid_by_dev_port(parent, 0, smcd->pnetid))
 424                 smc_pnetid_by_table_smcd(smcd);
 425
 426         spin_lock_init(&smcd->lock);
 427         spin_lock_init(&smcd->lgr_lock);
 428         INIT_LIST_HEAD(&smcd->vlan);
 429         INIT_LIST_HEAD(&smcd->lgr_list);
 430         init_waitqueue_head(&smcd->lgrs_deleted);
 431         return smcd;
 432 }
 433 EXPORT_SYMBOL_GPL(smcd_alloc_dev);
 434
 435 int smcd_register_dev(struct smcd_dev *smcd)
 436 {
 437         int rc;
 438
 439         mutex_lock(&smcd_dev_list.mutex);
 440         if (list_empty(&smcd_dev_list.list)) {
 441                 u8 *system_eid = NULL;
 442
 443                 smcd->ops->get_system_eid(smcd, &system_eid);
 444                 if (system_eid[24] != '0' || system_eid[28] != '0') {
 445                         smc_ism_v2_capable = true;
 446                         memcpy(smc_ism_v2_system_eid, system_eid,
 447                                SMC_MAX_EID_LEN);
 448                 }
 449         }
 450         /* sort list: devices without pnetid before devices with pnetid */
 451         if (smcd->pnetid[0])
 452                 list_add_tail(&smcd->list, &smcd_dev_list.list);
 453         else
 454                 list_add(&smcd->list, &smcd_dev_list.list);
 455         mutex_unlock(&smcd_dev_list.mutex);
 456
 457         pr_warn_ratelimited("smc: adding smcd device %s with pnetid %.16s%s\n",
 458                             dev_name(&smcd->dev), smcd->pnetid,
 459                             smcd->pnetid_by_user ? " (user defined)" : "");
 460
 461         rc = device_add(&smcd->dev);
 462         if (rc) {
 463                 mutex_lock(&smcd_dev_list.mutex);
 464                 list_del(&smcd->list);
 465                 mutex_unlock(&smcd_dev_list.mutex);
 466         }
 467
 468         return rc;
 469 }
 470 EXPORT_SYMBOL_GPL(smcd_register_dev);
 471
 472 void smcd_unregister_dev(struct smcd_dev *smcd)
 473 {
 474         pr_warn_ratelimited("smc: removing smcd device %s\n",
 475                             dev_name(&smcd->dev));
 476         mutex_lock(&smcd_dev_list.mutex);
 477         list_del_init(&smcd->list);
 478         mutex_unlock(&smcd_dev_list.mutex);
 479         smcd->going_away = 1;
 480         smc_smcd_terminate_all(smcd);
 481         destroy_workqueue(smcd->event_wq);
 482
 483         device_del(&smcd->dev);
 484 }
 485 EXPORT_SYMBOL_GPL(smcd_unregister_dev);
 486
 487 void smcd_free_dev(struct smcd_dev *smcd)
 488 {
 489         put_device(&smcd->dev);
 490 }
 491 EXPORT_SYMBOL_GPL(smcd_free_dev);
 492
 493 /* SMCD Device event handler. Called from ISM device interrupt handler.
 494  * Parameters are smcd device pointer,
 495  * - event->type (0 --> DMB, 1 --> GID),
 496  * - event->code (event code),
 497  * - event->tok (either DMB token when event type 0, or GID when event type 1)
 498  * - event->time (time of day)
 499  * - event->info (debug info).
 500  *
 501  * Context:
 502  * - Function called in IRQ context from ISM device driver event handler.
 503  */
 504 void smcd_handle_event(struct smcd_dev *smcd, struct smcd_event *event)
 505 {
 506         struct smc_ism_event_work *wrk;
 507
 508         if (smcd->going_away)
 509                 return;
 510         /* copy event to event work queue, and let it be handled there */
 511         wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
 512         if (!wrk)
 513                 return;
 514         INIT_WORK(&wrk->work, smc_ism_event_work);
 515         wrk->smcd = smcd;
 516         wrk->event = *event;
 517         queue_work(smcd->event_wq, &wrk->work);
 518 }
 519 EXPORT_SYMBOL_GPL(smcd_handle_event);
 520
 521 /* SMCD Device interrupt handler. Called from ISM device interrupt handler.
 522  * Parameters are smcd device pointer and DMB number. Find the connection and
 523  * schedule the tasklet for this connection.
 524  *
 525  * Context:
 526  * - Function called in IRQ context from ISM device driver IRQ handler.
 527  */
 528 void smcd_handle_irq(struct smcd_dev *smcd, unsigned int dmbno)
 529 {
 530         struct smc_connection *conn = NULL;
 531         unsigned long flags;
 532
 533         spin_lock_irqsave(&smcd->lock, flags);
 534         conn = smcd->conn[dmbno];
 535         if (conn && !conn->killed)
 536                 tasklet_schedule(&conn->rx_tsklet);
 537         spin_unlock_irqrestore(&smcd->lock, flags);
 538 }
 539 EXPORT_SYMBOL_GPL(smcd_handle_irq);
 540
 541 void __init smc_ism_init(void)
 542 {
 543         smc_ism_v2_capable = false;
 544         memset(smc_ism_v2_system_eid, 0, SMC_MAX_EID_LEN);
 545 }