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