drivers/staging/rdma/ehca/ehca_irq.c

   1 /*
   2  *  IBM eServer eHCA Infiniband device driver for Linux on POWER
   3  *
   4  *  Functions for EQs, NEQs and interrupts
   5  *
   6  *  Authors: Heiko J Schick <schickhj@de.ibm.com>
   7  *           Khadija Souissi <souissi@de.ibm.com>
   8  *           Hoang-Nam Nguyen <hnguyen@de.ibm.com>
   9  *           Joachim Fenkes <fenkes@de.ibm.com>
  10  *
  11  *  Copyright (c) 2005 IBM Corporation
  12  *
  13  *  All rights reserved.
  14  *
  15  *  This source code is distributed under a dual license of GPL v2.0 and OpenIB
  16  *  BSD.
  17  *
  18  * OpenIB BSD License
  19  *
  20  * Redistribution and use in source and binary forms, with or without
  21  * modification, are permitted provided that the following conditions are met:
  22  *
  23  * Redistributions of source code must retain the above copyright notice, this
  24  * list of conditions and the following disclaimer.
  25  *
  26  * Redistributions in binary form must reproduce the above copyright notice,
  27  * this list of conditions and the following disclaimer in the documentation
  28  * and/or other materials
  29  * provided with the distribution.
  30  *
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  32  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  33  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  34  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  35  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  36  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  37  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  38  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
  39  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  40  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGE.
  42  */
  43
  44 #include <linux/slab.h>
  45 #include <linux/smpboot.h>
  46
  47 #include "ehca_classes.h"
  48 #include "ehca_irq.h"
  49 #include "ehca_iverbs.h"
  50 #include "ehca_tools.h"
  51 #include "hcp_if.h"
  52 #include "hipz_fns.h"
  53 #include "ipz_pt_fn.h"
  54
  55 #define EQE_COMPLETION_EVENT   EHCA_BMASK_IBM( 1,  1)
  56 #define EQE_CQ_QP_NUMBER       EHCA_BMASK_IBM( 8, 31)
  57 #define EQE_EE_IDENTIFIER      EHCA_BMASK_IBM( 2,  7)
  58 #define EQE_CQ_NUMBER          EHCA_BMASK_IBM( 8, 31)
  59 #define EQE_QP_NUMBER          EHCA_BMASK_IBM( 8, 31)
  60 #define EQE_QP_TOKEN           EHCA_BMASK_IBM(32, 63)
  61 #define EQE_CQ_TOKEN           EHCA_BMASK_IBM(32, 63)
  62
  63 #define NEQE_COMPLETION_EVENT  EHCA_BMASK_IBM( 1,  1)
  64 #define NEQE_EVENT_CODE        EHCA_BMASK_IBM( 2,  7)
  65 #define NEQE_PORT_NUMBER       EHCA_BMASK_IBM( 8, 15)
  66 #define NEQE_PORT_AVAILABILITY EHCA_BMASK_IBM(16, 16)
  67 #define NEQE_DISRUPTIVE        EHCA_BMASK_IBM(16, 16)
  68 #define NEQE_SPECIFIC_EVENT    EHCA_BMASK_IBM(16, 23)
  69
  70 #define ERROR_DATA_LENGTH      EHCA_BMASK_IBM(52, 63)
  71 #define ERROR_DATA_TYPE        EHCA_BMASK_IBM( 0,  7)
  72
  73 static void queue_comp_task(struct ehca_cq *__cq);
  74
  75 static struct ehca_comp_pool *pool;
  76
  77 static inline void comp_event_callback(struct ehca_cq *cq)
  78 {
  79         if (!cq->ib_cq.comp_handler)
  80                 return;
  81
  82         spin_lock(&cq->cb_lock);
  83         cq->ib_cq.comp_handler(&cq->ib_cq, cq->ib_cq.cq_context);
  84         spin_unlock(&cq->cb_lock);
  85
  86         return;
  87 }
  88
  89 static void print_error_data(struct ehca_shca *shca, void *data,
  90                              u64 *rblock, int length)
  91 {
  92         u64 type = EHCA_BMASK_GET(ERROR_DATA_TYPE, rblock[2]);
  93         u64 resource = rblock[1];
  94
  95         switch (type) {
  96         case 0x1: /* Queue Pair */
  97         {
  98                 struct ehca_qp *qp = (struct ehca_qp *)data;
  99
 100                 /* only print error data if AER is set */
 101                 if (rblock[6] == 0)
 102                         return;
 103
 104                 ehca_err(&shca->ib_device,
 105                          "QP 0x%x (resource=%llx) has errors.",
 106                          qp->ib_qp.qp_num, resource);
 107                 break;
 108         }
 109         case 0x4: /* Completion Queue */
 110         {
 111                 struct ehca_cq *cq = (struct ehca_cq *)data;
 112
 113                 ehca_err(&shca->ib_device,
 114                          "CQ 0x%x (resource=%llx) has errors.",
 115                          cq->cq_number, resource);
 116                 break;
 117         }
 118         default:
 119                 ehca_err(&shca->ib_device,
 120                          "Unknown error type: %llx on %s.",
 121                          type, shca->ib_device.name);
 122                 break;
 123         }
 124
 125         ehca_err(&shca->ib_device, "Error data is available: %llx.", resource);
 126         ehca_err(&shca->ib_device, "EHCA ----- error data begin "
 127                  "---------------------------------------------------");
 128         ehca_dmp(rblock, length, "resource=%llx", resource);
 129         ehca_err(&shca->ib_device, "EHCA ----- error data end "
 130                  "----------------------------------------------------");
 131
 132         return;
 133 }
 134
 135 int ehca_error_data(struct ehca_shca *shca, void *data,
 136                     u64 resource)
 137 {
 138
 139         unsigned long ret;
 140         u64 *rblock;
 141         unsigned long block_count;
 142
 143         rblock = ehca_alloc_fw_ctrlblock(GFP_ATOMIC);
 144         if (!rblock) {
 145                 ehca_err(&shca->ib_device, "Cannot allocate rblock memory.");
 146                 ret = -ENOMEM;
 147                 goto error_data1;
 148         }
 149
 150         /* rblock must be 4K aligned and should be 4K large */
 151         ret = hipz_h_error_data(shca->ipz_hca_handle,
 152                                 resource,
 153                                 rblock,
 154                                 &block_count);
 155
 156         if (ret == H_R_STATE)
 157                 ehca_err(&shca->ib_device,
 158                          "No error data is available: %llx.", resource);
 159         else if (ret == H_SUCCESS) {
 160                 int length;
 161
 162                 length = EHCA_BMASK_GET(ERROR_DATA_LENGTH, rblock[0]);
 163
 164                 if (length > EHCA_PAGESIZE)
 165                         length = EHCA_PAGESIZE;
 166
 167                 print_error_data(shca, data, rblock, length);
 168         } else
 169                 ehca_err(&shca->ib_device,
 170                          "Error data could not be fetched: %llx", resource);
 171
 172         ehca_free_fw_ctrlblock(rblock);
 173
 174 error_data1:
 175         return ret;
 176
 177 }
 178
 179 static void dispatch_qp_event(struct ehca_shca *shca, struct ehca_qp *qp,
 180                               enum ib_event_type event_type)
 181 {
 182         struct ib_event event;
 183
 184         /* PATH_MIG without the QP ever having been armed is false alarm */
 185         if (event_type == IB_EVENT_PATH_MIG && !qp->mig_armed)
 186                 return;
 187
 188         event.device = &shca->ib_device;
 189         event.event = event_type;
 190
 191         if (qp->ext_type == EQPT_SRQ) {
 192                 if (!qp->ib_srq.event_handler)
 193                         return;
 194
 195                 event.element.srq = &qp->ib_srq;
 196                 qp->ib_srq.event_handler(&event, qp->ib_srq.srq_context);
 197         } else {
 198                 if (!qp->ib_qp.event_handler)
 199                         return;
 200
 201                 event.element.qp = &qp->ib_qp;
 202                 qp->ib_qp.event_handler(&event, qp->ib_qp.qp_context);
 203         }
 204 }
 205
 206 static void qp_event_callback(struct ehca_shca *shca, u64 eqe,
 207                               enum ib_event_type event_type, int fatal)
 208 {
 209         struct ehca_qp *qp;
 210         u32 token = EHCA_BMASK_GET(EQE_QP_TOKEN, eqe);
 211
 212         read_lock(&ehca_qp_idr_lock);
 213         qp = idr_find(&ehca_qp_idr, token);
 214         if (qp)
 215                 atomic_inc(&qp->nr_events);
 216         read_unlock(&ehca_qp_idr_lock);
 217
 218         if (!qp)
 219                 return;
 220
 221         if (fatal)
 222                 ehca_error_data(shca, qp, qp->ipz_qp_handle.handle);
 223
 224         dispatch_qp_event(shca, qp, fatal && qp->ext_type == EQPT_SRQ ?
 225                           IB_EVENT_SRQ_ERR : event_type);
 226
 227         /*
 228          * eHCA only processes one WQE at a time for SRQ base QPs,
 229          * so the last WQE has been processed as soon as the QP enters
 230          * error state.
 231          */
 232         if (fatal && qp->ext_type == EQPT_SRQBASE)
 233                 dispatch_qp_event(shca, qp, IB_EVENT_QP_LAST_WQE_REACHED);
 234
 235         if (atomic_dec_and_test(&qp->nr_events))
 236                 wake_up(&qp->wait_completion);
 237         return;
 238 }
 239
 240 static void cq_event_callback(struct ehca_shca *shca,
 241                               u64 eqe)
 242 {
 243         struct ehca_cq *cq;
 244         u32 token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe);
 245
 246         read_lock(&ehca_cq_idr_lock);
 247         cq = idr_find(&ehca_cq_idr, token);
 248         if (cq)
 249                 atomic_inc(&cq->nr_events);
 250         read_unlock(&ehca_cq_idr_lock);
 251
 252         if (!cq)
 253                 return;
 254
 255         ehca_error_data(shca, cq, cq->ipz_cq_handle.handle);
 256
 257         if (atomic_dec_and_test(&cq->nr_events))
 258                 wake_up(&cq->wait_completion);
 259
 260         return;
 261 }
 262
 263 static void parse_identifier(struct ehca_shca *shca, u64 eqe)
 264 {
 265         u8 identifier = EHCA_BMASK_GET(EQE_EE_IDENTIFIER, eqe);
 266
 267         switch (identifier) {
 268         case 0x02: /* path migrated */
 269                 qp_event_callback(shca, eqe, IB_EVENT_PATH_MIG, 0);
 270                 break;
 271         case 0x03: /* communication established */
 272                 qp_event_callback(shca, eqe, IB_EVENT_COMM_EST, 0);
 273                 break;
 274         case 0x04: /* send queue drained */
 275                 qp_event_callback(shca, eqe, IB_EVENT_SQ_DRAINED, 0);
 276                 break;
 277         case 0x05: /* QP error */
 278         case 0x06: /* QP error */
 279                 qp_event_callback(shca, eqe, IB_EVENT_QP_FATAL, 1);
 280                 break;
 281         case 0x07: /* CQ error */
 282         case 0x08: /* CQ error */
 283                 cq_event_callback(shca, eqe);
 284                 break;
 285         case 0x09: /* MRMWPTE error */
 286                 ehca_err(&shca->ib_device, "MRMWPTE error.");
 287                 break;
 288         case 0x0A: /* port event */
 289                 ehca_err(&shca->ib_device, "Port event.");
 290                 break;
 291         case 0x0B: /* MR access error */
 292                 ehca_err(&shca->ib_device, "MR access error.");
 293                 break;
 294         case 0x0C: /* EQ error */
 295                 ehca_err(&shca->ib_device, "EQ error.");
 296                 break;
 297         case 0x0D: /* P/Q_Key mismatch */
 298                 ehca_err(&shca->ib_device, "P/Q_Key mismatch.");
 299                 break;
 300         case 0x10: /* sampling complete */
 301                 ehca_err(&shca->ib_device, "Sampling complete.");
 302                 break;
 303         case 0x11: /* unaffiliated access error */
 304                 ehca_err(&shca->ib_device, "Unaffiliated access error.");
 305                 break;
 306         case 0x12: /* path migrating */
 307                 ehca_err(&shca->ib_device, "Path migrating.");
 308                 break;
 309         case 0x13: /* interface trace stopped */
 310                 ehca_err(&shca->ib_device, "Interface trace stopped.");
 311                 break;
 312         case 0x14: /* first error capture info available */
 313                 ehca_info(&shca->ib_device, "First error capture available");
 314                 break;
 315         case 0x15: /* SRQ limit reached */
 316                 qp_event_callback(shca, eqe, IB_EVENT_SRQ_LIMIT_REACHED, 0);
 317                 break;
 318         default:
 319                 ehca_err(&shca->ib_device, "Unknown identifier: %x on %s.",
 320                          identifier, shca->ib_device.name);
 321                 break;
 322         }
 323
 324         return;
 325 }
 326
 327 static void dispatch_port_event(struct ehca_shca *shca, int port_num,
 328                                 enum ib_event_type type, const char *msg)
 329 {
 330         struct ib_event event;
 331
 332         ehca_info(&shca->ib_device, "port %d %s.", port_num, msg);
 333         event.device = &shca->ib_device;
 334         event.event = type;
 335         event.element.port_num = port_num;
 336         ib_dispatch_event(&event);
 337 }
 338
 339 static void notify_port_conf_change(struct ehca_shca *shca, int port_num)
 340 {
 341         struct ehca_sma_attr  new_attr;
 342         struct ehca_sma_attr *old_attr = &shca->sport[port_num - 1].saved_attr;
 343
 344         ehca_query_sma_attr(shca, port_num, &new_attr);
 345
 346         if (new_attr.sm_sl  != old_attr->sm_sl ||
 347             new_attr.sm_lid != old_attr->sm_lid)
 348                 dispatch_port_event(shca, port_num, IB_EVENT_SM_CHANGE,
 349                                     "SM changed");
 350
 351         if (new_attr.lid != old_attr->lid ||
 352             new_attr.lmc != old_attr->lmc)
 353                 dispatch_port_event(shca, port_num, IB_EVENT_LID_CHANGE,
 354                                     "LID changed");
 355
 356         if (new_attr.pkey_tbl_len != old_attr->pkey_tbl_len ||
 357             memcmp(new_attr.pkeys, old_attr->pkeys,
 358                    sizeof(u16) * new_attr.pkey_tbl_len))
 359                 dispatch_port_event(shca, port_num, IB_EVENT_PKEY_CHANGE,
 360                                     "P_Key changed");
 361
 362         *old_attr = new_attr;
 363 }
 364
 365 /* replay modify_qp for sqps -- return 0 if all is well, 1 if AQP1 destroyed */
 366 static int replay_modify_qp(struct ehca_sport *sport)
 367 {
 368         int aqp1_destroyed;
 369         unsigned long flags;
 370
 371         spin_lock_irqsave(&sport->mod_sqp_lock, flags);
 372
 373         aqp1_destroyed = !sport->ibqp_sqp[IB_QPT_GSI];
 374
 375         if (sport->ibqp_sqp[IB_QPT_SMI])
 376                 ehca_recover_sqp(sport->ibqp_sqp[IB_QPT_SMI]);
 377         if (!aqp1_destroyed)
 378                 ehca_recover_sqp(sport->ibqp_sqp[IB_QPT_GSI]);
 379
 380         spin_unlock_irqrestore(&sport->mod_sqp_lock, flags);
 381
 382         return aqp1_destroyed;
 383 }
 384
 385 static void parse_ec(struct ehca_shca *shca, u64 eqe)
 386 {
 387         u8 ec   = EHCA_BMASK_GET(NEQE_EVENT_CODE, eqe);
 388         u8 port = EHCA_BMASK_GET(NEQE_PORT_NUMBER, eqe);
 389         u8 spec_event;
 390         struct ehca_sport *sport = &shca->sport[port - 1];
 391
 392         switch (ec) {
 393         case 0x30: /* port availability change */
 394                 if (EHCA_BMASK_GET(NEQE_PORT_AVAILABILITY, eqe)) {
 395                         /* only replay modify_qp calls in autodetect mode;
 396                          * if AQP1 was destroyed, the port is already down
 397                          * again and we can drop the event.
 398                          */
 399                         if (ehca_nr_ports < 0)
 400                                 if (replay_modify_qp(sport))
 401                                         break;
 402
 403                         sport->port_state = IB_PORT_ACTIVE;
 404                         dispatch_port_event(shca, port, IB_EVENT_PORT_ACTIVE,
 405                                             "is active");
 406                         ehca_query_sma_attr(shca, port, &sport->saved_attr);
 407                 } else {
 408                         sport->port_state = IB_PORT_DOWN;
 409                         dispatch_port_event(shca, port, IB_EVENT_PORT_ERR,
 410                                             "is inactive");
 411                 }
 412                 break;
 413         case 0x31:
 414                 /* port configuration change
 415                  * disruptive change is caused by
 416                  * LID, PKEY or SM change
 417                  */
 418                 if (EHCA_BMASK_GET(NEQE_DISRUPTIVE, eqe)) {
 419                         ehca_warn(&shca->ib_device, "disruptive port "
 420                                   "%d configuration change", port);
 421
 422                         sport->port_state = IB_PORT_DOWN;
 423                         dispatch_port_event(shca, port, IB_EVENT_PORT_ERR,
 424                                             "is inactive");
 425
 426                         sport->port_state = IB_PORT_ACTIVE;
 427                         dispatch_port_event(shca, port, IB_EVENT_PORT_ACTIVE,
 428                                             "is active");
 429                         ehca_query_sma_attr(shca, port,
 430                                             &sport->saved_attr);
 431                 } else
 432                         notify_port_conf_change(shca, port);
 433                 break;
 434         case 0x32: /* adapter malfunction */
 435                 ehca_err(&shca->ib_device, "Adapter malfunction.");
 436                 break;
 437         case 0x33:  /* trace stopped */
 438                 ehca_err(&shca->ib_device, "Traced stopped.");
 439                 break;
 440         case 0x34: /* util async event */
 441                 spec_event = EHCA_BMASK_GET(NEQE_SPECIFIC_EVENT, eqe);
 442                 if (spec_event == 0x80) /* client reregister required */
 443                         dispatch_port_event(shca, port,
 444                                             IB_EVENT_CLIENT_REREGISTER,
 445                                             "client reregister req.");
 446                 else
 447                         ehca_warn(&shca->ib_device, "Unknown util async "
 448                                   "event %x on port %x", spec_event, port);
 449                 break;
 450         default:
 451                 ehca_err(&shca->ib_device, "Unknown event code: %x on %s.",
 452                          ec, shca->ib_device.name);
 453                 break;
 454         }
 455
 456         return;
 457 }
 458
 459 static inline void reset_eq_pending(struct ehca_cq *cq)
 460 {
 461         u64 CQx_EP;
 462         struct h_galpa gal = cq->galpas.kernel;
 463
 464         hipz_galpa_store_cq(gal, cqx_ep, 0x0);
 465         CQx_EP = hipz_galpa_load(gal, CQTEMM_OFFSET(cqx_ep));
 466
 467         return;
 468 }
 469
 470 irqreturn_t ehca_interrupt_neq(int irq, void *dev_id)
 471 {
 472         struct ehca_shca *shca = (struct ehca_shca*)dev_id;
 473
 474         tasklet_hi_schedule(&shca->neq.interrupt_task);
 475
 476         return IRQ_HANDLED;
 477 }
 478
 479 void ehca_tasklet_neq(unsigned long data)
 480 {
 481         struct ehca_shca *shca = (struct ehca_shca*)data;
 482         struct ehca_eqe *eqe;
 483         u64 ret;
 484
 485         eqe = ehca_poll_eq(shca, &shca->neq);
 486
 487         while (eqe) {
 488                 if (!EHCA_BMASK_GET(NEQE_COMPLETION_EVENT, eqe->entry))
 489                         parse_ec(shca, eqe->entry);
 490
 491                 eqe = ehca_poll_eq(shca, &shca->neq);
 492         }
 493
 494         ret = hipz_h_reset_event(shca->ipz_hca_handle,
 495                                  shca->neq.ipz_eq_handle, 0xFFFFFFFFFFFFFFFFL);
 496
 497         if (ret != H_SUCCESS)
 498                 ehca_err(&shca->ib_device, "Can't clear notification events.");
 499
 500         return;
 501 }
 502
 503 irqreturn_t ehca_interrupt_eq(int irq, void *dev_id)
 504 {
 505         struct ehca_shca *shca = (struct ehca_shca*)dev_id;
 506
 507         tasklet_hi_schedule(&shca->eq.interrupt_task);
 508
 509         return IRQ_HANDLED;
 510 }
 511
 512
 513 static inline void process_eqe(struct ehca_shca *shca, struct ehca_eqe *eqe)
 514 {
 515         u64 eqe_value;
 516         u32 token;
 517         struct ehca_cq *cq;
 518
 519         eqe_value = eqe->entry;
 520         ehca_dbg(&shca->ib_device, "eqe_value=%llx", eqe_value);
 521         if (EHCA_BMASK_GET(EQE_COMPLETION_EVENT, eqe_value)) {
 522                 ehca_dbg(&shca->ib_device, "Got completion event");
 523                 token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe_value);
 524                 read_lock(&ehca_cq_idr_lock);
 525                 cq = idr_find(&ehca_cq_idr, token);
 526                 if (cq)
 527                         atomic_inc(&cq->nr_events);
 528                 read_unlock(&ehca_cq_idr_lock);
 529                 if (cq == NULL) {
 530                         ehca_err(&shca->ib_device,
 531                                  "Invalid eqe for non-existing cq token=%x",
 532                                  token);
 533                         return;
 534                 }
 535                 reset_eq_pending(cq);
 536                 if (ehca_scaling_code)
 537                         queue_comp_task(cq);
 538                 else {
 539                         comp_event_callback(cq);
 540                         if (atomic_dec_and_test(&cq->nr_events))
 541                                 wake_up(&cq->wait_completion);
 542                 }
 543         } else {
 544                 ehca_dbg(&shca->ib_device, "Got non completion event");
 545                 parse_identifier(shca, eqe_value);
 546         }
 547 }
 548
 549 void ehca_process_eq(struct ehca_shca *shca, int is_irq)
 550 {
 551         struct ehca_eq *eq = &shca->eq;
 552         struct ehca_eqe_cache_entry *eqe_cache = eq->eqe_cache;
 553         u64 eqe_value, ret;
 554         int eqe_cnt, i;
 555         int eq_empty = 0;
 556
 557         spin_lock(&eq->irq_spinlock);
 558         if (is_irq) {
 559                 const int max_query_cnt = 100;
 560                 int query_cnt = 0;
 561                 int int_state = 1;
 562                 do {
 563                         int_state = hipz_h_query_int_state(
 564                                 shca->ipz_hca_handle, eq->ist);
 565                         query_cnt++;
 566                         iosync();
 567                 } while (int_state && query_cnt < max_query_cnt);
 568                 if (unlikely((query_cnt == max_query_cnt)))
 569                         ehca_dbg(&shca->ib_device, "int_state=%x query_cnt=%x",
 570                                  int_state, query_cnt);
 571         }
 572
 573         /* read out all eqes */
 574         eqe_cnt = 0;
 575         do {
 576                 u32 token;
 577                 eqe_cache[eqe_cnt].eqe = ehca_poll_eq(shca, eq);
 578                 if (!eqe_cache[eqe_cnt].eqe)
 579                         break;
 580                 eqe_value = eqe_cache[eqe_cnt].eqe->entry;
 581                 if (EHCA_BMASK_GET(EQE_COMPLETION_EVENT, eqe_value)) {
 582                         token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe_value);
 583                         read_lock(&ehca_cq_idr_lock);
 584                         eqe_cache[eqe_cnt].cq = idr_find(&ehca_cq_idr, token);
 585                         if (eqe_cache[eqe_cnt].cq)
 586                                 atomic_inc(&eqe_cache[eqe_cnt].cq->nr_events);
 587                         read_unlock(&ehca_cq_idr_lock);
 588                         if (!eqe_cache[eqe_cnt].cq) {
 589                                 ehca_err(&shca->ib_device,
 590                                          "Invalid eqe for non-existing cq "
 591                                          "token=%x", token);
 592                                 continue;
 593                         }
 594                 } else
 595                         eqe_cache[eqe_cnt].cq = NULL;
 596                 eqe_cnt++;
 597         } while (eqe_cnt < EHCA_EQE_CACHE_SIZE);
 598         if (!eqe_cnt) {
 599                 if (is_irq)
 600                         ehca_dbg(&shca->ib_device,
 601                                  "No eqe found for irq event");
 602                 goto unlock_irq_spinlock;
 603         } else if (!is_irq) {
 604                 ret = hipz_h_eoi(eq->ist);
 605                 if (ret != H_SUCCESS)
 606                         ehca_err(&shca->ib_device,
 607                                  "bad return code EOI -rc = %lld\n", ret);
 608                 ehca_dbg(&shca->ib_device, "deadman found %x eqe", eqe_cnt);
 609         }
 610         if (unlikely(eqe_cnt == EHCA_EQE_CACHE_SIZE))
 611                 ehca_dbg(&shca->ib_device, "too many eqes for one irq event");
 612         /* enable irq for new packets */
 613         for (i = 0; i < eqe_cnt; i++) {
 614                 if (eq->eqe_cache[i].cq)
 615                         reset_eq_pending(eq->eqe_cache[i].cq);
 616         }
 617         /* check eq */
 618         spin_lock(&eq->spinlock);
 619         eq_empty = (!ipz_eqit_eq_peek_valid(&shca->eq.ipz_queue));
 620         spin_unlock(&eq->spinlock);
 621         /* call completion handler for cached eqes */
 622         for (i = 0; i < eqe_cnt; i++)
 623                 if (eq->eqe_cache[i].cq) {
 624                         if (ehca_scaling_code)
 625                                 queue_comp_task(eq->eqe_cache[i].cq);
 626                         else {
 627                                 struct ehca_cq *cq = eq->eqe_cache[i].cq;
 628                                 comp_event_callback(cq);
 629                                 if (atomic_dec_and_test(&cq->nr_events))
 630                                         wake_up(&cq->wait_completion);
 631                         }
 632                 } else {
 633                         ehca_dbg(&shca->ib_device, "Got non completion event");
 634                         parse_identifier(shca, eq->eqe_cache[i].eqe->entry);
 635                 }
 636         /* poll eq if not empty */
 637         if (eq_empty)
 638                 goto unlock_irq_spinlock;
 639         do {
 640                 struct ehca_eqe *eqe;
 641                 eqe = ehca_poll_eq(shca, &shca->eq);
 642                 if (!eqe)
 643                         break;
 644                 process_eqe(shca, eqe);
 645         } while (1);
 646
 647 unlock_irq_spinlock:
 648         spin_unlock(&eq->irq_spinlock);
 649 }
 650
 651 void ehca_tasklet_eq(unsigned long data)
 652 {
 653         ehca_process_eq((struct ehca_shca*)data, 1);
 654 }
 655
 656 static int find_next_online_cpu(struct ehca_comp_pool *pool)
 657 {
 658         int cpu;
 659         unsigned long flags;
 660
 661         WARN_ON_ONCE(!in_interrupt());
 662         if (ehca_debug_level >= 3)
 663                 ehca_dmp(cpu_online_mask, cpumask_size(), "");
 664
 665         spin_lock_irqsave(&pool->last_cpu_lock, flags);
 666         do {
 667                 cpu = cpumask_next(pool->last_cpu, cpu_online_mask);
 668                 if (cpu >= nr_cpu_ids)
 669                         cpu = cpumask_first(cpu_online_mask);
 670                 pool->last_cpu = cpu;
 671         } while (!per_cpu_ptr(pool->cpu_comp_tasks, cpu)->active);
 672         spin_unlock_irqrestore(&pool->last_cpu_lock, flags);
 673
 674         return cpu;
 675 }
 676
 677 static void __queue_comp_task(struct ehca_cq *__cq,
 678                               struct ehca_cpu_comp_task *cct,
 679                               struct task_struct *thread)
 680 {
 681         unsigned long flags;
 682
 683         spin_lock_irqsave(&cct->task_lock, flags);
 684         spin_lock(&__cq->task_lock);
 685
 686         if (__cq->nr_callbacks == 0) {
 687                 __cq->nr_callbacks++;
 688                 list_add_tail(&__cq->entry, &cct->cq_list);
 689                 cct->cq_jobs++;
 690                 wake_up_process(thread);
 691         } else
 692                 __cq->nr_callbacks++;
 693
 694         spin_unlock(&__cq->task_lock);
 695         spin_unlock_irqrestore(&cct->task_lock, flags);
 696 }
 697
 698 static void queue_comp_task(struct ehca_cq *__cq)
 699 {
 700         int cpu_id;
 701         struct ehca_cpu_comp_task *cct;
 702         struct task_struct *thread;
 703         int cq_jobs;
 704         unsigned long flags;
 705
 706         cpu_id = find_next_online_cpu(pool);
 707         BUG_ON(!cpu_online(cpu_id));
 708
 709         cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu_id);
 710         thread = *per_cpu_ptr(pool->cpu_comp_threads, cpu_id);
 711         BUG_ON(!cct || !thread);
 712
 713         spin_lock_irqsave(&cct->task_lock, flags);
 714         cq_jobs = cct->cq_jobs;
 715         spin_unlock_irqrestore(&cct->task_lock, flags);
 716         if (cq_jobs > 0) {
 717                 cpu_id = find_next_online_cpu(pool);
 718                 cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu_id);
 719                 thread = *per_cpu_ptr(pool->cpu_comp_threads, cpu_id);
 720                 BUG_ON(!cct || !thread);
 721         }
 722         __queue_comp_task(__cq, cct, thread);
 723 }
 724
 725 static void run_comp_task(struct ehca_cpu_comp_task *cct)
 726 {
 727         struct ehca_cq *cq;
 728
 729         while (!list_empty(&cct->cq_list)) {
 730                 cq = list_entry(cct->cq_list.next, struct ehca_cq, entry);
 731                 spin_unlock_irq(&cct->task_lock);
 732
 733                 comp_event_callback(cq);
 734                 if (atomic_dec_and_test(&cq->nr_events))
 735                         wake_up(&cq->wait_completion);
 736
 737                 spin_lock_irq(&cct->task_lock);
 738                 spin_lock(&cq->task_lock);
 739                 cq->nr_callbacks--;
 740                 if (!cq->nr_callbacks) {
 741                         list_del_init(cct->cq_list.next);
 742                         cct->cq_jobs--;
 743                 }
 744                 spin_unlock(&cq->task_lock);
 745         }
 746 }
 747
 748 static void comp_task_park(unsigned int cpu)
 749 {
 750         struct ehca_cpu_comp_task *cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 751         struct ehca_cpu_comp_task *target;
 752         struct task_struct *thread;
 753         struct ehca_cq *cq, *tmp;
 754         LIST_HEAD(list);
 755
 756         spin_lock_irq(&cct->task_lock);
 757         cct->cq_jobs = 0;
 758         cct->active = 0;
 759         list_splice_init(&cct->cq_list, &list);
 760         spin_unlock_irq(&cct->task_lock);
 761
 762         cpu = find_next_online_cpu(pool);
 763         target = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 764         thread = *per_cpu_ptr(pool->cpu_comp_threads, cpu);
 765         spin_lock_irq(&target->task_lock);
 766         list_for_each_entry_safe(cq, tmp, &list, entry) {
 767                 list_del(&cq->entry);
 768                 __queue_comp_task(cq, target, thread);
 769         }
 770         spin_unlock_irq(&target->task_lock);
 771 }
 772
 773 static void comp_task_stop(unsigned int cpu, bool online)
 774 {
 775         struct ehca_cpu_comp_task *cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 776
 777         spin_lock_irq(&cct->task_lock);
 778         cct->cq_jobs = 0;
 779         cct->active = 0;
 780         WARN_ON(!list_empty(&cct->cq_list));
 781         spin_unlock_irq(&cct->task_lock);
 782 }
 783
 784 static int comp_task_should_run(unsigned int cpu)
 785 {
 786         struct ehca_cpu_comp_task *cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 787
 788         return cct->cq_jobs;
 789 }
 790
 791 static void comp_task(unsigned int cpu)
 792 {
 793         struct ehca_cpu_comp_task *cct = this_cpu_ptr(pool->cpu_comp_tasks);
 794         int cql_empty;
 795
 796         spin_lock_irq(&cct->task_lock);
 797         cql_empty = list_empty(&cct->cq_list);
 798         if (!cql_empty) {
 799                 __set_current_state(TASK_RUNNING);
 800                 run_comp_task(cct);
 801         }
 802         spin_unlock_irq(&cct->task_lock);
 803 }
 804
 805 static struct smp_hotplug_thread comp_pool_threads = {
 806         .thread_should_run      = comp_task_should_run,
 807         .thread_fn              = comp_task,
 808         .thread_comm            = "ehca_comp/%u",
 809         .cleanup                = comp_task_stop,
 810         .park                   = comp_task_park,
 811 };
 812
 813 int ehca_create_comp_pool(void)
 814 {
 815         int cpu, ret = -ENOMEM;
 816
 817         if (!ehca_scaling_code)
 818                 return 0;
 819
 820         pool = kzalloc(sizeof(struct ehca_comp_pool), GFP_KERNEL);
 821         if (pool == NULL)
 822                 return -ENOMEM;
 823
 824         spin_lock_init(&pool->last_cpu_lock);
 825         pool->last_cpu = cpumask_any(cpu_online_mask);
 826
 827         pool->cpu_comp_tasks = alloc_percpu(struct ehca_cpu_comp_task);
 828         if (!pool->cpu_comp_tasks)
 829                 goto out_pool;
 830
 831         pool->cpu_comp_threads = alloc_percpu(struct task_struct *);
 832         if (!pool->cpu_comp_threads)
 833                 goto out_tasks;
 834
 835         for_each_present_cpu(cpu) {
 836                 struct ehca_cpu_comp_task *cct;
 837
 838                 cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 839                 spin_lock_init(&cct->task_lock);
 840                 INIT_LIST_HEAD(&cct->cq_list);
 841         }
 842
 843         comp_pool_threads.store = pool->cpu_comp_threads;
 844         ret = smpboot_register_percpu_thread(&comp_pool_threads);
 845         if (ret)
 846                 goto out_threads;
 847
 848         pr_info("eHCA scaling code enabled\n");
 849         return ret;
 850
 851 out_threads:
 852         free_percpu(pool->cpu_comp_threads);
 853 out_tasks:
 854         free_percpu(pool->cpu_comp_tasks);
 855 out_pool:
 856         kfree(pool);
 857         return ret;
 858 }
 859
 860 void ehca_destroy_comp_pool(void)
 861 {
 862         if (!ehca_scaling_code)
 863                 return;
 864
 865         smpboot_unregister_percpu_thread(&comp_pool_threads);
 866
 867         free_percpu(pool->cpu_comp_threads);
 868         free_percpu(pool->cpu_comp_tasks);
 869         kfree(pool);
 870 }