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 #include "linux/ism.h"
  21
  22 struct smcd_dev_list smcd_dev_list = {
  23         .list = LIST_HEAD_INIT(smcd_dev_list.list),
  24         .mutex = __MUTEX_INITIALIZER(smcd_dev_list.mutex)
  25 };
  26
  27 static bool smc_ism_v2_capable;
  28 static u8 smc_ism_v2_system_eid[SMC_MAX_EID_LEN];
  29
  30 #if IS_ENABLED(CONFIG_ISM)
  31 static void smcd_register_dev(struct ism_dev *ism);
  32 static void smcd_unregister_dev(struct ism_dev *ism);
  33 static void smcd_handle_event(struct ism_dev *ism, struct ism_event *event);
  34 static void smcd_handle_irq(struct ism_dev *ism, unsigned int dmbno,
  35                             u16 dmbemask);
  36
  37 static struct ism_client smc_ism_client = {
  38         .name = "SMC-D",
  39         .add = smcd_register_dev,
  40         .remove = smcd_unregister_dev,
  41         .handle_event = smcd_handle_event,
  42         .handle_irq = smcd_handle_irq,
  43 };
  44 #endif
  45
  46 /* Test if an ISM communication is possible - same CPC */
  47 int smc_ism_cantalk(u64 peer_gid, unsigned short vlan_id, struct smcd_dev *smcd)
  48 {
  49         return smcd->ops->query_remote_gid(smcd, peer_gid, vlan_id ? 1 : 0,
  50                                            vlan_id);
  51 }
  52
  53 void smc_ism_get_system_eid(u8 **eid)
  54 {
  55         if (!smc_ism_v2_capable)
  56                 *eid = NULL;
  57         else
  58                 *eid = smc_ism_v2_system_eid;
  59 }
  60
  61 u16 smc_ism_get_chid(struct smcd_dev *smcd)
  62 {
  63         return smcd->ops->get_chid(smcd);
  64 }
  65
  66 /* HW supports ISM V2 and thus System EID is defined */
  67 bool smc_ism_is_v2_capable(void)
  68 {
  69         return smc_ism_v2_capable;
  70 }
  71
  72 /* Set a connection using this DMBE. */
  73 void smc_ism_set_conn(struct smc_connection *conn)
  74 {
  75         unsigned long flags;
  76
  77         spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
  78         conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = conn;
  79         spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
  80 }
  81
  82 /* Unset a connection using this DMBE. */
  83 void smc_ism_unset_conn(struct smc_connection *conn)
  84 {
  85         unsigned long flags;
  86
  87         if (!conn->rmb_desc)
  88                 return;
  89
  90         spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
  91         conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = NULL;
  92         spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
  93 }
  94
  95 /* Register a VLAN identifier with the ISM device. Use a reference count
  96  * and add a VLAN identifier only when the first DMB using this VLAN is
  97  * registered.
  98  */
  99 int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid)
 100 {
 101         struct smc_ism_vlanid *new_vlan, *vlan;
 102         unsigned long flags;
 103         int rc = 0;
 104
 105         if (!vlanid)                    /* No valid vlan id */
 106                 return -EINVAL;
 107
 108         /* create new vlan entry, in case we need it */
 109         new_vlan = kzalloc(sizeof(*new_vlan), GFP_KERNEL);
 110         if (!new_vlan)
 111                 return -ENOMEM;
 112         new_vlan->vlanid = vlanid;
 113         refcount_set(&new_vlan->refcnt, 1);
 114
 115         /* if there is an existing entry, increase count and return */
 116         spin_lock_irqsave(&smcd->lock, flags);
 117         list_for_each_entry(vlan, &smcd->vlan, list) {
 118                 if (vlan->vlanid == vlanid) {
 119                         refcount_inc(&vlan->refcnt);
 120                         kfree(new_vlan);
 121                         goto out;
 122                 }
 123         }
 124
 125         /* no existing entry found.
 126          * add new entry to device; might fail, e.g., if HW limit reached
 127          */
 128         if (smcd->ops->add_vlan_id(smcd, vlanid)) {
 129                 kfree(new_vlan);
 130                 rc = -EIO;
 131                 goto out;
 132         }
 133         list_add_tail(&new_vlan->list, &smcd->vlan);
 134 out:
 135         spin_unlock_irqrestore(&smcd->lock, flags);
 136         return rc;
 137 }
 138
 139 /* Unregister a VLAN identifier with the ISM device. Use a reference count
 140  * and remove a VLAN identifier only when the last DMB using this VLAN is
 141  * unregistered.
 142  */
 143 int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)
 144 {
 145         struct smc_ism_vlanid *vlan;
 146         unsigned long flags;
 147         bool found = false;
 148         int rc = 0;
 149
 150         if (!vlanid)                    /* No valid vlan id */
 151                 return -EINVAL;
 152
 153         spin_lock_irqsave(&smcd->lock, flags);
 154         list_for_each_entry(vlan, &smcd->vlan, list) {
 155                 if (vlan->vlanid == vlanid) {
 156                         if (!refcount_dec_and_test(&vlan->refcnt))
 157                                 goto out;
 158                         found = true;
 159                         break;
 160                 }
 161         }
 162         if (!found) {
 163                 rc = -ENOENT;
 164                 goto out;               /* VLAN id not in table */
 165         }
 166
 167         /* Found and the last reference just gone */
 168         if (smcd->ops->del_vlan_id(smcd, vlanid))
 169                 rc = -EIO;
 170         list_del(&vlan->list);
 171         kfree(vlan);
 172 out:
 173         spin_unlock_irqrestore(&smcd->lock, flags);
 174         return rc;
 175 }
 176
 177 int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
 178 {
 179         struct smcd_dmb dmb;
 180         int rc = 0;
 181
 182         if (!dmb_desc->dma_addr)
 183                 return rc;
 184
 185         memset(&dmb, 0, sizeof(dmb));
 186         dmb.dmb_tok = dmb_desc->token;
 187         dmb.sba_idx = dmb_desc->sba_idx;
 188         dmb.cpu_addr = dmb_desc->cpu_addr;
 189         dmb.dma_addr = dmb_desc->dma_addr;
 190         dmb.dmb_len = dmb_desc->len;
 191         rc = smcd->ops->unregister_dmb(smcd, &dmb);
 192         if (!rc || rc == ISM_ERROR) {
 193                 dmb_desc->cpu_addr = NULL;
 194                 dmb_desc->dma_addr = 0;
 195         }
 196
 197         return rc;
 198 }
 199
 200 int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
 201                          struct smc_buf_desc *dmb_desc)
 202 {
 203 #if IS_ENABLED(CONFIG_ISM)
 204         struct smcd_dmb dmb;
 205         int rc;
 206
 207         memset(&dmb, 0, sizeof(dmb));
 208         dmb.dmb_len = dmb_len;
 209         dmb.sba_idx = dmb_desc->sba_idx;
 210         dmb.vlan_id = lgr->vlan_id;
 211         dmb.rgid = lgr->peer_gid;
 212         rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb, &smc_ism_client);
 213         if (!rc) {
 214                 dmb_desc->sba_idx = dmb.sba_idx;
 215                 dmb_desc->token = dmb.dmb_tok;
 216                 dmb_desc->cpu_addr = dmb.cpu_addr;
 217                 dmb_desc->dma_addr = dmb.dma_addr;
 218                 dmb_desc->len = dmb.dmb_len;
 219         }
 220         return rc;
 221 #else
 222         return 0;
 223 #endif
 224 }
 225
 226 static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd,
 227                                   struct sk_buff *skb,
 228                                   struct netlink_callback *cb)
 229 {
 230         char smc_pnet[SMC_MAX_PNETID_LEN + 1];
 231         struct smc_pci_dev smc_pci_dev;
 232         struct nlattr *port_attrs;
 233         struct nlattr *attrs;
 234         struct ism_dev *ism;
 235         int use_cnt = 0;
 236         void *nlh;
 237
 238         ism = smcd->priv;
 239         nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 240                           &smc_gen_nl_family, NLM_F_MULTI,
 241                           SMC_NETLINK_GET_DEV_SMCD);
 242         if (!nlh)
 243                 goto errmsg;
 244         attrs = nla_nest_start(skb, SMC_GEN_DEV_SMCD);
 245         if (!attrs)
 246                 goto errout;
 247         use_cnt = atomic_read(&smcd->lgr_cnt);
 248         if (nla_put_u32(skb, SMC_NLA_DEV_USE_CNT, use_cnt))
 249                 goto errattr;
 250         if (nla_put_u8(skb, SMC_NLA_DEV_IS_CRIT, use_cnt > 0))
 251                 goto errattr;
 252         memset(&smc_pci_dev, 0, sizeof(smc_pci_dev));
 253         smc_set_pci_values(to_pci_dev(ism->dev.parent), &smc_pci_dev);
 254         if (nla_put_u32(skb, SMC_NLA_DEV_PCI_FID, smc_pci_dev.pci_fid))
 255                 goto errattr;
 256         if (nla_put_u16(skb, SMC_NLA_DEV_PCI_CHID, smc_pci_dev.pci_pchid))
 257                 goto errattr;
 258         if (nla_put_u16(skb, SMC_NLA_DEV_PCI_VENDOR, smc_pci_dev.pci_vendor))
 259                 goto errattr;
 260         if (nla_put_u16(skb, SMC_NLA_DEV_PCI_DEVICE, smc_pci_dev.pci_device))
 261                 goto errattr;
 262         if (nla_put_string(skb, SMC_NLA_DEV_PCI_ID, smc_pci_dev.pci_id))
 263                 goto errattr;
 264
 265         port_attrs = nla_nest_start(skb, SMC_NLA_DEV_PORT);
 266         if (!port_attrs)
 267                 goto errattr;
 268         if (nla_put_u8(skb, SMC_NLA_DEV_PORT_PNET_USR, smcd->pnetid_by_user))
 269                 goto errportattr;
 270         memcpy(smc_pnet, smcd->pnetid, SMC_MAX_PNETID_LEN);
 271         smc_pnet[SMC_MAX_PNETID_LEN] = 0;
 272         if (nla_put_string(skb, SMC_NLA_DEV_PORT_PNETID, smc_pnet))
 273                 goto errportattr;
 274
 275         nla_nest_end(skb, port_attrs);
 276         nla_nest_end(skb, attrs);
 277         genlmsg_end(skb, nlh);
 278         return 0;
 279
 280 errportattr:
 281         nla_nest_cancel(skb, port_attrs);
 282 errattr:
 283         nla_nest_cancel(skb, attrs);
 284 errout:
 285         nlmsg_cancel(skb, nlh);
 286 errmsg:
 287         return -EMSGSIZE;
 288 }
 289
 290 static void smc_nl_prep_smcd_dev(struct smcd_dev_list *dev_list,
 291                                  struct sk_buff *skb,
 292                                  struct netlink_callback *cb)
 293 {
 294         struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
 295         int snum = cb_ctx->pos[0];
 296         struct smcd_dev *smcd;
 297         int num = 0;
 298
 299         mutex_lock(&dev_list->mutex);
 300         list_for_each_entry(smcd, &dev_list->list, list) {
 301                 if (num < snum)
 302                         goto next;
 303                 if (smc_nl_handle_smcd_dev(smcd, skb, cb))
 304                         goto errout;
 305 next:
 306                 num++;
 307         }
 308 errout:
 309         mutex_unlock(&dev_list->mutex);
 310         cb_ctx->pos[0] = num;
 311 }
 312
 313 int smcd_nl_get_device(struct sk_buff *skb, struct netlink_callback *cb)
 314 {
 315         smc_nl_prep_smcd_dev(&smcd_dev_list, skb, cb);
 316         return skb->len;
 317 }
 318
 319 #if IS_ENABLED(CONFIG_ISM)
 320 struct smc_ism_event_work {
 321         struct work_struct work;
 322         struct smcd_dev *smcd;
 323         struct ism_event event;
 324 };
 325
 326 #define ISM_EVENT_REQUEST               0x0001
 327 #define ISM_EVENT_RESPONSE              0x0002
 328 #define ISM_EVENT_REQUEST_IR            0x00000001
 329 #define ISM_EVENT_CODE_SHUTDOWN         0x80
 330 #define ISM_EVENT_CODE_TESTLINK         0x83
 331
 332 union smcd_sw_event_info {
 333         u64     info;
 334         struct {
 335                 u8              uid[SMC_LGR_ID_SIZE];
 336                 unsigned short  vlan_id;
 337                 u16             code;
 338         };
 339 };
 340
 341 static void smcd_handle_sw_event(struct smc_ism_event_work *wrk)
 342 {
 343         union smcd_sw_event_info ev_info;
 344
 345         ev_info.info = wrk->event.info;
 346         switch (wrk->event.code) {
 347         case ISM_EVENT_CODE_SHUTDOWN:   /* Peer shut down DMBs */
 348                 smc_smcd_terminate(wrk->smcd, wrk->event.tok, ev_info.vlan_id);
 349                 break;
 350         case ISM_EVENT_CODE_TESTLINK:   /* Activity timer */
 351                 if (ev_info.code == ISM_EVENT_REQUEST) {
 352                         ev_info.code = ISM_EVENT_RESPONSE;
 353                         wrk->smcd->ops->signal_event(wrk->smcd,
 354                                                      wrk->event.tok,
 355                                                      ISM_EVENT_REQUEST_IR,
 356                                                      ISM_EVENT_CODE_TESTLINK,
 357                                                      ev_info.info);
 358                         }
 359                 break;
 360         }
 361 }
 362
 363 /* worker for SMC-D events */
 364 static void smc_ism_event_work(struct work_struct *work)
 365 {
 366         struct smc_ism_event_work *wrk =
 367                 container_of(work, struct smc_ism_event_work, work);
 368
 369         switch (wrk->event.type) {
 370         case ISM_EVENT_GID:     /* GID event, token is peer GID */
 371                 smc_smcd_terminate(wrk->smcd, wrk->event.tok, VLAN_VID_MASK);
 372                 break;
 373         case ISM_EVENT_DMB:
 374                 break;
 375         case ISM_EVENT_SWR:     /* Software defined event */
 376                 smcd_handle_sw_event(wrk);
 377                 break;
 378         }
 379         kfree(wrk);
 380 }
 381
 382 static struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name,
 383                                        const struct smcd_ops *ops, int max_dmbs)
 384 {
 385         struct smcd_dev *smcd;
 386
 387         smcd = devm_kzalloc(parent, sizeof(*smcd), GFP_KERNEL);
 388         if (!smcd)
 389                 return NULL;
 390         smcd->conn = devm_kcalloc(parent, max_dmbs,
 391                                   sizeof(struct smc_connection *), GFP_KERNEL);
 392         if (!smcd->conn)
 393                 return NULL;
 394
 395         smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)",
 396                                                  WQ_MEM_RECLAIM, name);
 397         if (!smcd->event_wq)
 398                 return NULL;
 399
 400         smcd->ops = ops;
 401
 402         spin_lock_init(&smcd->lock);
 403         spin_lock_init(&smcd->lgr_lock);
 404         INIT_LIST_HEAD(&smcd->vlan);
 405         INIT_LIST_HEAD(&smcd->lgr_list);
 406         init_waitqueue_head(&smcd->lgrs_deleted);
 407         return smcd;
 408 }
 409
 410 static void smcd_register_dev(struct ism_dev *ism)
 411 {
 412         const struct smcd_ops *ops = ism_get_smcd_ops();
 413         struct smcd_dev *smcd;
 414
 415         if (!ops)
 416                 return;
 417
 418         smcd = smcd_alloc_dev(&ism->pdev->dev, dev_name(&ism->pdev->dev), ops,
 419                               ISM_NR_DMBS);
 420         if (!smcd)
 421                 return;
 422         smcd->priv = ism;
 423         ism_set_priv(ism, &smc_ism_client, smcd);
 424         if (smc_pnetid_by_dev_port(&ism->pdev->dev, 0, smcd->pnetid))
 425                 smc_pnetid_by_table_smcd(smcd);
 426
 427         mutex_lock(&smcd_dev_list.mutex);
 428         if (list_empty(&smcd_dev_list.list)) {
 429                 u8 *system_eid = NULL;
 430
 431                 system_eid = smcd->ops->get_system_eid();
 432                 if (smcd->ops->supports_v2()) {
 433                         smc_ism_v2_capable = true;
 434                         memcpy(smc_ism_v2_system_eid, system_eid,
 435                                SMC_MAX_EID_LEN);
 436                 }
 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(&ism->dev), smcd->pnetid,
 447                             smcd->pnetid_by_user ? " (user defined)" : "");
 448
 449         return;
 450 }
 451
 452 static void smcd_unregister_dev(struct ism_dev *ism)
 453 {
 454         struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client);
 455
 456         pr_warn_ratelimited("smc: removing smcd device %s\n",
 457                             dev_name(&ism->dev));
 458         smcd->going_away = 1;
 459         smc_smcd_terminate_all(smcd);
 460         mutex_lock(&smcd_dev_list.mutex);
 461         list_del_init(&smcd->list);
 462         mutex_unlock(&smcd_dev_list.mutex);
 463         destroy_workqueue(smcd->event_wq);
 464 }
 465
 466 /* SMCD Device event handler. Called from ISM device interrupt handler.
 467  * Parameters are ism device pointer,
 468  * - event->type (0 --> DMB, 1 --> GID),
 469  * - event->code (event code),
 470  * - event->tok (either DMB token when event type 0, or GID when event type 1)
 471  * - event->time (time of day)
 472  * - event->info (debug info).
 473  *
 474  * Context:
 475  * - Function called in IRQ context from ISM device driver event handler.
 476  */
 477 static void smcd_handle_event(struct ism_dev *ism, struct ism_event *event)
 478 {
 479         struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client);
 480         struct smc_ism_event_work *wrk;
 481
 482         if (smcd->going_away)
 483                 return;
 484         /* copy event to event work queue, and let it be handled there */
 485         wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
 486         if (!wrk)
 487                 return;
 488         INIT_WORK(&wrk->work, smc_ism_event_work);
 489         wrk->smcd = smcd;
 490         wrk->event = *event;
 491         queue_work(smcd->event_wq, &wrk->work);
 492 }
 493
 494 /* SMCD Device interrupt handler. Called from ISM device interrupt handler.
 495  * Parameters are the ism device pointer, DMB number, and the DMBE bitmask.
 496  * Find the connection and schedule the tasklet for this connection.
 497  *
 498  * Context:
 499  * - Function called in IRQ context from ISM device driver IRQ handler.
 500  */
 501 static void smcd_handle_irq(struct ism_dev *ism, unsigned int dmbno,
 502                             u16 dmbemask)
 503 {
 504         struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client);
 505         struct smc_connection *conn = NULL;
 506         unsigned long flags;
 507
 508         spin_lock_irqsave(&smcd->lock, flags);
 509         conn = smcd->conn[dmbno];
 510         if (conn && !conn->killed)
 511                 tasklet_schedule(&conn->rx_tsklet);
 512         spin_unlock_irqrestore(&smcd->lock, flags);
 513 }
 514 #endif
 515
 516 int smc_ism_signal_shutdown(struct smc_link_group *lgr)
 517 {
 518         int rc = 0;
 519 #if IS_ENABLED(CONFIG_ISM)
 520         union smcd_sw_event_info ev_info;
 521
 522         if (lgr->peer_shutdown)
 523                 return 0;
 524
 525         memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE);
 526         ev_info.vlan_id = lgr->vlan_id;
 527         ev_info.code = ISM_EVENT_REQUEST;
 528         rc = lgr->smcd->ops->signal_event(lgr->smcd, lgr->peer_gid,
 529                                           ISM_EVENT_REQUEST_IR,
 530                                           ISM_EVENT_CODE_SHUTDOWN,
 531                                           ev_info.info);
 532 #endif
 533         return rc;
 534 }
 535
 536 int smc_ism_init(void)
 537 {
 538         int rc = 0;
 539
 540 #if IS_ENABLED(CONFIG_ISM)
 541         smc_ism_v2_capable = false;
 542         memset(smc_ism_v2_system_eid, 0, SMC_MAX_EID_LEN);
 543
 544         rc = ism_register_client(&smc_ism_client);
 545 #endif
 546         return rc;
 547 }
 548
 549 void smc_ism_exit(void)
 550 {
 551 #if IS_ENABLED(CONFIG_ISM)
 552         ism_unregister_client(&smc_ism_client);
 553 #endif
 554 }