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 static void smc_ism_create_system_eid(void)
  47 {
  48         struct smc_ism_seid *seid =
  49                 (struct smc_ism_seid *)smc_ism_v2_system_eid;
  50 #if IS_ENABLED(CONFIG_S390)
  51         struct cpuid id;
  52         u16 ident_tail;
  53         char tmp[5];
  54
  55         memcpy(seid->seid_string, "IBM-SYSZ-ISMSEID00000000", 24);
  56         get_cpu_id(&id);
  57         ident_tail = (u16)(id.ident & SMC_ISM_IDENT_MASK);
  58         snprintf(tmp, 5, "%04X", ident_tail);
  59         memcpy(seid->serial_number, tmp, 4);
  60         snprintf(tmp, 5, "%04X", id.machine);
  61         memcpy(seid->type, tmp, 4);
  62 #else
  63         memset(seid, 0, SMC_MAX_EID_LEN);
  64 #endif
  65 }
  66
  67 /* Test if an ISM communication is possible - same CPC */
  68 int smc_ism_cantalk(struct smcd_gid *peer_gid, unsigned short vlan_id,
  69                     struct smcd_dev *smcd)
  70 {
  71         return smcd->ops->query_remote_gid(smcd, peer_gid, vlan_id ? 1 : 0,
  72                                            vlan_id);
  73 }
  74
  75 void smc_ism_get_system_eid(u8 **eid)
  76 {
  77         if (!smc_ism_v2_capable)
  78                 *eid = NULL;
  79         else
  80                 *eid = smc_ism_v2_system_eid;
  81 }
  82
  83 u16 smc_ism_get_chid(struct smcd_dev *smcd)
  84 {
  85         return smcd->ops->get_chid(smcd);
  86 }
  87
  88 /* HW supports ISM V2 and thus System EID is defined */
  89 bool smc_ism_is_v2_capable(void)
  90 {
  91         return smc_ism_v2_capable;
  92 }
  93
  94 /* Set a connection using this DMBE. */
  95 void smc_ism_set_conn(struct smc_connection *conn)
  96 {
  97         unsigned long flags;
  98
  99         spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
 100         conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = conn;
 101         spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
 102 }
 103
 104 /* Unset a connection using this DMBE. */
 105 void smc_ism_unset_conn(struct smc_connection *conn)
 106 {
 107         unsigned long flags;
 108
 109         if (!conn->rmb_desc)
 110                 return;
 111
 112         spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
 113         conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = NULL;
 114         spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
 115 }
 116
 117 /* Register a VLAN identifier with the ISM device. Use a reference count
 118  * and add a VLAN identifier only when the first DMB using this VLAN is
 119  * registered.
 120  */
 121 int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid)
 122 {
 123         struct smc_ism_vlanid *new_vlan, *vlan;
 124         unsigned long flags;
 125         int rc = 0;
 126
 127         if (!vlanid)                    /* No valid vlan id */
 128                 return -EINVAL;
 129
 130         /* create new vlan entry, in case we need it */
 131         new_vlan = kzalloc(sizeof(*new_vlan), GFP_KERNEL);
 132         if (!new_vlan)
 133                 return -ENOMEM;
 134         new_vlan->vlanid = vlanid;
 135         refcount_set(&new_vlan->refcnt, 1);
 136
 137         /* if there is an existing entry, increase count and return */
 138         spin_lock_irqsave(&smcd->lock, flags);
 139         list_for_each_entry(vlan, &smcd->vlan, list) {
 140                 if (vlan->vlanid == vlanid) {
 141                         refcount_inc(&vlan->refcnt);
 142                         kfree(new_vlan);
 143                         goto out;
 144                 }
 145         }
 146
 147         /* no existing entry found.
 148          * add new entry to device; might fail, e.g., if HW limit reached
 149          */
 150         if (smcd->ops->add_vlan_id(smcd, vlanid)) {
 151                 kfree(new_vlan);
 152                 rc = -EIO;
 153                 goto out;
 154         }
 155         list_add_tail(&new_vlan->list, &smcd->vlan);
 156 out:
 157         spin_unlock_irqrestore(&smcd->lock, flags);
 158         return rc;
 159 }
 160
 161 /* Unregister a VLAN identifier with the ISM device. Use a reference count
 162  * and remove a VLAN identifier only when the last DMB using this VLAN is
 163  * unregistered.
 164  */
 165 int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)
 166 {
 167         struct smc_ism_vlanid *vlan;
 168         unsigned long flags;
 169         bool found = false;
 170         int rc = 0;
 171
 172         if (!vlanid)                    /* No valid vlan id */
 173                 return -EINVAL;
 174
 175         spin_lock_irqsave(&smcd->lock, flags);
 176         list_for_each_entry(vlan, &smcd->vlan, list) {
 177                 if (vlan->vlanid == vlanid) {
 178                         if (!refcount_dec_and_test(&vlan->refcnt))
 179                                 goto out;
 180                         found = true;
 181                         break;
 182                 }
 183         }
 184         if (!found) {
 185                 rc = -ENOENT;
 186                 goto out;               /* VLAN id not in table */
 187         }
 188
 189         /* Found and the last reference just gone */
 190         if (smcd->ops->del_vlan_id(smcd, vlanid))
 191                 rc = -EIO;
 192         list_del(&vlan->list);
 193         kfree(vlan);
 194 out:
 195         spin_unlock_irqrestore(&smcd->lock, flags);
 196         return rc;
 197 }
 198
 199 int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
 200 {
 201         struct smcd_dmb dmb;
 202         int rc = 0;
 203
 204         if (!dmb_desc->dma_addr)
 205                 return rc;
 206
 207         memset(&dmb, 0, sizeof(dmb));
 208         dmb.dmb_tok = dmb_desc->token;
 209         dmb.sba_idx = dmb_desc->sba_idx;
 210         dmb.cpu_addr = dmb_desc->cpu_addr;
 211         dmb.dma_addr = dmb_desc->dma_addr;
 212         dmb.dmb_len = dmb_desc->len;
 213         rc = smcd->ops->unregister_dmb(smcd, &dmb);
 214         if (!rc || rc == ISM_ERROR) {
 215                 dmb_desc->cpu_addr = NULL;
 216                 dmb_desc->dma_addr = 0;
 217         }
 218
 219         return rc;
 220 }
 221
 222 int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
 223                          struct smc_buf_desc *dmb_desc)
 224 {
 225 #if IS_ENABLED(CONFIG_ISM)
 226         struct smcd_dmb dmb;
 227         int rc;
 228
 229         memset(&dmb, 0, sizeof(dmb));
 230         dmb.dmb_len = dmb_len;
 231         dmb.sba_idx = dmb_desc->sba_idx;
 232         dmb.vlan_id = lgr->vlan_id;
 233         dmb.rgid = lgr->peer_gid.gid;
 234         rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb, &smc_ism_client);
 235         if (!rc) {
 236                 dmb_desc->sba_idx = dmb.sba_idx;
 237                 dmb_desc->token = dmb.dmb_tok;
 238                 dmb_desc->cpu_addr = dmb.cpu_addr;
 239                 dmb_desc->dma_addr = dmb.dma_addr;
 240                 dmb_desc->len = dmb.dmb_len;
 241         }
 242         return rc;
 243 #else
 244         return 0;
 245 #endif
 246 }
 247
 248 static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd,
 249                                   struct sk_buff *skb,
 250                                   struct netlink_callback *cb)
 251 {
 252         char smc_pnet[SMC_MAX_PNETID_LEN + 1];
 253         struct smc_pci_dev smc_pci_dev;
 254         struct nlattr *port_attrs;
 255         struct nlattr *attrs;
 256         struct ism_dev *ism;
 257         int use_cnt = 0;
 258         void *nlh;
 259
 260         ism = smcd->priv;
 261         nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 262                           &smc_gen_nl_family, NLM_F_MULTI,
 263                           SMC_NETLINK_GET_DEV_SMCD);
 264         if (!nlh)
 265                 goto errmsg;
 266         attrs = nla_nest_start(skb, SMC_GEN_DEV_SMCD);
 267         if (!attrs)
 268                 goto errout;
 269         use_cnt = atomic_read(&smcd->lgr_cnt);
 270         if (nla_put_u32(skb, SMC_NLA_DEV_USE_CNT, use_cnt))
 271                 goto errattr;
 272         if (nla_put_u8(skb, SMC_NLA_DEV_IS_CRIT, use_cnt > 0))
 273                 goto errattr;
 274         memset(&smc_pci_dev, 0, sizeof(smc_pci_dev));
 275         smc_set_pci_values(to_pci_dev(ism->dev.parent), &smc_pci_dev);
 276         if (nla_put_u32(skb, SMC_NLA_DEV_PCI_FID, smc_pci_dev.pci_fid))
 277                 goto errattr;
 278         if (nla_put_u16(skb, SMC_NLA_DEV_PCI_CHID, smc_pci_dev.pci_pchid))
 279                 goto errattr;
 280         if (nla_put_u16(skb, SMC_NLA_DEV_PCI_VENDOR, smc_pci_dev.pci_vendor))
 281                 goto errattr;
 282         if (nla_put_u16(skb, SMC_NLA_DEV_PCI_DEVICE, smc_pci_dev.pci_device))
 283                 goto errattr;
 284         if (nla_put_string(skb, SMC_NLA_DEV_PCI_ID, smc_pci_dev.pci_id))
 285                 goto errattr;
 286
 287         port_attrs = nla_nest_start(skb, SMC_NLA_DEV_PORT);
 288         if (!port_attrs)
 289                 goto errattr;
 290         if (nla_put_u8(skb, SMC_NLA_DEV_PORT_PNET_USR, smcd->pnetid_by_user))
 291                 goto errportattr;
 292         memcpy(smc_pnet, smcd->pnetid, SMC_MAX_PNETID_LEN);
 293         smc_pnet[SMC_MAX_PNETID_LEN] = 0;
 294         if (nla_put_string(skb, SMC_NLA_DEV_PORT_PNETID, smc_pnet))
 295                 goto errportattr;
 296
 297         nla_nest_end(skb, port_attrs);
 298         nla_nest_end(skb, attrs);
 299         genlmsg_end(skb, nlh);
 300         return 0;
 301
 302 errportattr:
 303         nla_nest_cancel(skb, port_attrs);
 304 errattr:
 305         nla_nest_cancel(skb, attrs);
 306 errout:
 307         nlmsg_cancel(skb, nlh);
 308 errmsg:
 309         return -EMSGSIZE;
 310 }
 311
 312 static void smc_nl_prep_smcd_dev(struct smcd_dev_list *dev_list,
 313                                  struct sk_buff *skb,
 314                                  struct netlink_callback *cb)
 315 {
 316         struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
 317         int snum = cb_ctx->pos[0];
 318         struct smcd_dev *smcd;
 319         int num = 0;
 320
 321         mutex_lock(&dev_list->mutex);
 322         list_for_each_entry(smcd, &dev_list->list, list) {
 323                 if (num < snum)
 324                         goto next;
 325                 if (smc_nl_handle_smcd_dev(smcd, skb, cb))
 326                         goto errout;
 327 next:
 328                 num++;
 329         }
 330 errout:
 331         mutex_unlock(&dev_list->mutex);
 332         cb_ctx->pos[0] = num;
 333 }
 334
 335 int smcd_nl_get_device(struct sk_buff *skb, struct netlink_callback *cb)
 336 {
 337         smc_nl_prep_smcd_dev(&smcd_dev_list, skb, cb);
 338         return skb->len;
 339 }
 340
 341 #if IS_ENABLED(CONFIG_ISM)
 342 struct smc_ism_event_work {
 343         struct work_struct work;
 344         struct smcd_dev *smcd;
 345         struct ism_event event;
 346 };
 347
 348 #define ISM_EVENT_REQUEST               0x0001
 349 #define ISM_EVENT_RESPONSE              0x0002
 350 #define ISM_EVENT_REQUEST_IR            0x00000001
 351 #define ISM_EVENT_CODE_SHUTDOWN         0x80
 352 #define ISM_EVENT_CODE_TESTLINK         0x83
 353
 354 union smcd_sw_event_info {
 355         u64     info;
 356         struct {
 357                 u8              uid[SMC_LGR_ID_SIZE];
 358                 unsigned short  vlan_id;
 359                 u16             code;
 360         };
 361 };
 362
 363 static void smcd_handle_sw_event(struct smc_ism_event_work *wrk)
 364 {
 365         struct smcd_gid peer_gid = { .gid = wrk->event.tok,
 366                                      .gid_ext = 0 };
 367         union smcd_sw_event_info ev_info;
 368
 369         ev_info.info = wrk->event.info;
 370         switch (wrk->event.code) {
 371         case ISM_EVENT_CODE_SHUTDOWN:   /* Peer shut down DMBs */
 372                 smc_smcd_terminate(wrk->smcd, &peer_gid, ev_info.vlan_id);
 373                 break;
 374         case ISM_EVENT_CODE_TESTLINK:   /* Activity timer */
 375                 if (ev_info.code == ISM_EVENT_REQUEST) {
 376                         ev_info.code = ISM_EVENT_RESPONSE;
 377                         wrk->smcd->ops->signal_event(wrk->smcd,
 378                                                      &peer_gid,
 379                                                      ISM_EVENT_REQUEST_IR,
 380                                                      ISM_EVENT_CODE_TESTLINK,
 381                                                      ev_info.info);
 382                         }
 383                 break;
 384         }
 385 }
 386
 387 /* worker for SMC-D events */
 388 static void smc_ism_event_work(struct work_struct *work)
 389 {
 390         struct smc_ism_event_work *wrk =
 391                 container_of(work, struct smc_ism_event_work, work);
 392         struct smcd_gid smcd_gid = { .gid = wrk->event.tok,
 393                                      .gid_ext = 0 };
 394
 395         switch (wrk->event.type) {
 396         case ISM_EVENT_GID:     /* GID event, token is peer GID */
 397                 smc_smcd_terminate(wrk->smcd, &smcd_gid, VLAN_VID_MASK);
 398                 break;
 399         case ISM_EVENT_DMB:
 400                 break;
 401         case ISM_EVENT_SWR:     /* Software defined event */
 402                 smcd_handle_sw_event(wrk);
 403                 break;
 404         }
 405         kfree(wrk);
 406 }
 407
 408 static struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name,
 409                                        const struct smcd_ops *ops, int max_dmbs)
 410 {
 411         struct smcd_dev *smcd;
 412
 413         smcd = devm_kzalloc(parent, sizeof(*smcd), GFP_KERNEL);
 414         if (!smcd)
 415                 return NULL;
 416         smcd->conn = devm_kcalloc(parent, max_dmbs,
 417                                   sizeof(struct smc_connection *), GFP_KERNEL);
 418         if (!smcd->conn)
 419                 return NULL;
 420
 421         smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)",
 422                                                  WQ_MEM_RECLAIM, name);
 423         if (!smcd->event_wq)
 424                 return NULL;
 425
 426         smcd->ops = ops;
 427
 428         spin_lock_init(&smcd->lock);
 429         spin_lock_init(&smcd->lgr_lock);
 430         INIT_LIST_HEAD(&smcd->vlan);
 431         INIT_LIST_HEAD(&smcd->lgr_list);
 432         init_waitqueue_head(&smcd->lgrs_deleted);
 433         return smcd;
 434 }
 435
 436 static void smcd_register_dev(struct ism_dev *ism)
 437 {
 438         const struct smcd_ops *ops = ism_get_smcd_ops();
 439         struct smcd_dev *smcd;
 440
 441         if (!ops)
 442                 return;
 443
 444         smcd = smcd_alloc_dev(&ism->pdev->dev, dev_name(&ism->pdev->dev), ops,
 445                               ISM_NR_DMBS);
 446         if (!smcd)
 447                 return;
 448         smcd->priv = ism;
 449         ism_set_priv(ism, &smc_ism_client, smcd);
 450         if (smc_pnetid_by_dev_port(&ism->pdev->dev, 0, smcd->pnetid))
 451                 smc_pnetid_by_table_smcd(smcd);
 452
 453         mutex_lock(&smcd_dev_list.mutex);
 454         if (list_empty(&smcd_dev_list.list)) {
 455                 if (smcd->ops->supports_v2())
 456                         smc_ism_v2_capable = true;
 457         }
 458         /* sort list: devices without pnetid before devices with pnetid */
 459         if (smcd->pnetid[0])
 460                 list_add_tail(&smcd->list, &smcd_dev_list.list);
 461         else
 462                 list_add(&smcd->list, &smcd_dev_list.list);
 463         mutex_unlock(&smcd_dev_list.mutex);
 464
 465         pr_warn_ratelimited("smc: adding smcd device %s with pnetid %.16s%s\n",
 466                             dev_name(&ism->dev), smcd->pnetid,
 467                             smcd->pnetid_by_user ? " (user defined)" : "");
 468
 469         return;
 470 }
 471
 472 static void smcd_unregister_dev(struct ism_dev *ism)
 473 {
 474         struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client);
 475
 476         pr_warn_ratelimited("smc: removing smcd device %s\n",
 477                             dev_name(&ism->dev));
 478         smcd->going_away = 1;
 479         smc_smcd_terminate_all(smcd);
 480         mutex_lock(&smcd_dev_list.mutex);
 481         list_del_init(&smcd->list);
 482         mutex_unlock(&smcd_dev_list.mutex);
 483         destroy_workqueue(smcd->event_wq);
 484 }
 485
 486 /* SMCD Device event handler. Called from ISM device interrupt handler.
 487  * Parameters are ism device pointer,
 488  * - event->type (0 --> DMB, 1 --> GID),
 489  * - event->code (event code),
 490  * - event->tok (either DMB token when event type 0, or GID when event type 1)
 491  * - event->time (time of day)
 492  * - event->info (debug info).
 493  *
 494  * Context:
 495  * - Function called in IRQ context from ISM device driver event handler.
 496  */
 497 static void smcd_handle_event(struct ism_dev *ism, struct ism_event *event)
 498 {
 499         struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client);
 500         struct smc_ism_event_work *wrk;
 501
 502         if (smcd->going_away)
 503                 return;
 504         /* copy event to event work queue, and let it be handled there */
 505         wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
 506         if (!wrk)
 507                 return;
 508         INIT_WORK(&wrk->work, smc_ism_event_work);
 509         wrk->smcd = smcd;
 510         wrk->event = *event;
 511         queue_work(smcd->event_wq, &wrk->work);
 512 }
 513
 514 /* SMCD Device interrupt handler. Called from ISM device interrupt handler.
 515  * Parameters are the ism device pointer, DMB number, and the DMBE bitmask.
 516  * Find the connection and schedule the tasklet for this connection.
 517  *
 518  * Context:
 519  * - Function called in IRQ context from ISM device driver IRQ handler.
 520  */
 521 static void smcd_handle_irq(struct ism_dev *ism, unsigned int dmbno,
 522                             u16 dmbemask)
 523 {
 524         struct smcd_dev *smcd = ism_get_priv(ism, &smc_ism_client);
 525         struct smc_connection *conn = NULL;
 526         unsigned long flags;
 527
 528         spin_lock_irqsave(&smcd->lock, flags);
 529         conn = smcd->conn[dmbno];
 530         if (conn && !conn->killed)
 531                 tasklet_schedule(&conn->rx_tsklet);
 532         spin_unlock_irqrestore(&smcd->lock, flags);
 533 }
 534 #endif
 535
 536 int smc_ism_signal_shutdown(struct smc_link_group *lgr)
 537 {
 538         int rc = 0;
 539 #if IS_ENABLED(CONFIG_ISM)
 540         union smcd_sw_event_info ev_info;
 541
 542         if (lgr->peer_shutdown)
 543                 return 0;
 544
 545         memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE);
 546         ev_info.vlan_id = lgr->vlan_id;
 547         ev_info.code = ISM_EVENT_REQUEST;
 548         rc = lgr->smcd->ops->signal_event(lgr->smcd, &lgr->peer_gid,
 549                                           ISM_EVENT_REQUEST_IR,
 550                                           ISM_EVENT_CODE_SHUTDOWN,
 551                                           ev_info.info);
 552 #endif
 553         return rc;
 554 }
 555
 556 int smc_ism_init(void)
 557 {
 558         int rc = 0;
 559
 560         smc_ism_v2_capable = false;
 561         smc_ism_create_system_eid();
 562
 563 #if IS_ENABLED(CONFIG_ISM)
 564         rc = ism_register_client(&smc_ism_client);
 565 #endif
 566         return rc;
 567 }
 568
 569 void smc_ism_exit(void)
 570 {
 571 #if IS_ENABLED(CONFIG_ISM)
 572         ism_unregister_client(&smc_ism_client);
 573 #endif
 574 }