git.oblomov.eu Git - linux-2.6/blob - drivers/infiniband/hw/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  *
   9  *  Copyright (c) 2005 IBM Corporation
  10  *
  11  *  All rights reserved.
  12  *
  13  *  This source code is distributed under a dual license of GPL v2.0 and OpenIB
  14  *  BSD.
  15  *
  16  * OpenIB BSD License
  17  *
  18  * Redistribution and use in source and binary forms, with or without
  19  * modification, are permitted provided that the following conditions are met:
  20  *
  21  * Redistributions of source code must retain the above copyright notice, this
  22  * list of conditions and the following disclaimer.
  23  *
  24  * Redistributions in binary form must reproduce the above copyright notice,
  25  * this list of conditions and the following disclaimer in the documentation
  26  * and/or other materials
  27  * provided with the distribution.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  30  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  33  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  34  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  35  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  36  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
  37  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  38  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  39  * POSSIBILITY OF SUCH DAMAGE.
  40  */
  41
  42 #include "ehca_classes.h"
  43 #include "ehca_irq.h"
  44 #include "ehca_iverbs.h"
  45 #include "ehca_tools.h"
  46 #include "hcp_if.h"
  47 #include "hipz_fns.h"
  48
  49 #define EQE_COMPLETION_EVENT   EHCA_BMASK_IBM(1,1)
  50 #define EQE_CQ_QP_NUMBER       EHCA_BMASK_IBM(8,31)
  51 #define EQE_EE_IDENTIFIER      EHCA_BMASK_IBM(2,7)
  52 #define EQE_CQ_NUMBER          EHCA_BMASK_IBM(8,31)
  53 #define EQE_QP_NUMBER          EHCA_BMASK_IBM(8,31)
  54 #define EQE_QP_TOKEN           EHCA_BMASK_IBM(32,63)
  55 #define EQE_CQ_TOKEN           EHCA_BMASK_IBM(32,63)
  56
  57 #define NEQE_COMPLETION_EVENT  EHCA_BMASK_IBM(1,1)
  58 #define NEQE_EVENT_CODE        EHCA_BMASK_IBM(2,7)
  59 #define NEQE_PORT_NUMBER       EHCA_BMASK_IBM(8,15)
  60 #define NEQE_PORT_AVAILABILITY EHCA_BMASK_IBM(16,16)
  61
  62 #define ERROR_DATA_LENGTH      EHCA_BMASK_IBM(52,63)
  63 #define ERROR_DATA_TYPE        EHCA_BMASK_IBM(0,7)
  64
  65 #ifdef CONFIG_INFINIBAND_EHCA_SCALING
  66
  67 static void queue_comp_task(struct ehca_cq *__cq);
  68
  69 static struct ehca_comp_pool* pool;
  70 static struct notifier_block comp_pool_callback_nb;
  71
  72 #endif
  73
  74 static inline void comp_event_callback(struct ehca_cq *cq)
  75 {
  76         if (!cq->ib_cq.comp_handler)
  77                 return;
  78
  79         spin_lock(&cq->cb_lock);
  80         cq->ib_cq.comp_handler(&cq->ib_cq, cq->ib_cq.cq_context);
  81         spin_unlock(&cq->cb_lock);
  82
  83         return;
  84 }
  85
  86 static void print_error_data(struct ehca_shca * shca, void* data,
  87                              u64* rblock, int length)
  88 {
  89         u64 type = EHCA_BMASK_GET(ERROR_DATA_TYPE, rblock[2]);
  90         u64 resource = rblock[1];
  91
  92         switch (type) {
  93         case 0x1: /* Queue Pair */
  94         {
  95                 struct ehca_qp *qp = (struct ehca_qp*)data;
  96
  97                 /* only print error data if AER is set */
  98                 if (rblock[6] == 0)
  99                         return;
 100
 101                 ehca_err(&shca->ib_device,
 102                          "QP 0x%x (resource=%lx) has errors.",
 103                          qp->ib_qp.qp_num, resource);
 104                 break;
 105         }
 106         case 0x4: /* Completion Queue */
 107         {
 108                 struct ehca_cq *cq = (struct ehca_cq*)data;
 109
 110                 ehca_err(&shca->ib_device,
 111                          "CQ 0x%x (resource=%lx) has errors.",
 112                          cq->cq_number, resource);
 113                 break;
 114         }
 115         default:
 116                 ehca_err(&shca->ib_device,
 117                          "Unknown errror type: %lx on %s.",
 118                          type, shca->ib_device.name);
 119                 break;
 120         }
 121
 122         ehca_err(&shca->ib_device, "Error data is available: %lx.", resource);
 123         ehca_err(&shca->ib_device, "EHCA ----- error data begin "
 124                  "---------------------------------------------------");
 125         ehca_dmp(rblock, length, "resource=%lx", resource);
 126         ehca_err(&shca->ib_device, "EHCA ----- error data end "
 127                  "----------------------------------------------------");
 128
 129         return;
 130 }
 131
 132 int ehca_error_data(struct ehca_shca *shca, void *data,
 133                     u64 resource)
 134 {
 135
 136         unsigned long ret;
 137         u64 *rblock;
 138         unsigned long block_count;
 139
 140         rblock = kzalloc(H_CB_ALIGNMENT, GFP_KERNEL);
 141         if (!rblock) {
 142                 ehca_err(&shca->ib_device, "Cannot allocate rblock memory.");
 143                 ret = -ENOMEM;
 144                 goto error_data1;
 145         }
 146
 147         ret = hipz_h_error_data(shca->ipz_hca_handle,
 148                                 resource,
 149                                 rblock,
 150                                 &block_count);
 151
 152         if (ret == H_R_STATE) {
 153                 ehca_err(&shca->ib_device,
 154                          "No error data is available: %lx.", resource);
 155         }
 156         else if (ret == H_SUCCESS) {
 157                 int length;
 158
 159                 length = EHCA_BMASK_GET(ERROR_DATA_LENGTH, rblock[0]);
 160
 161                 if (length > PAGE_SIZE)
 162                         length = PAGE_SIZE;
 163
 164                 print_error_data(shca, data, rblock, length);
 165         }
 166         else {
 167                 ehca_err(&shca->ib_device,
 168                          "Error data could not be fetched: %lx", resource);
 169         }
 170
 171         kfree(rblock);
 172
 173 error_data1:
 174         return ret;
 175
 176 }
 177
 178 static void qp_event_callback(struct ehca_shca *shca,
 179                               u64 eqe,
 180                               enum ib_event_type event_type)
 181 {
 182         struct ib_event event;
 183         struct ehca_qp *qp;
 184         unsigned long flags;
 185         u32 token = EHCA_BMASK_GET(EQE_QP_TOKEN, eqe);
 186
 187         spin_lock_irqsave(&ehca_qp_idr_lock, flags);
 188         qp = idr_find(&ehca_qp_idr, token);
 189         spin_unlock_irqrestore(&ehca_qp_idr_lock, flags);
 190
 191
 192         if (!qp)
 193                 return;
 194
 195         ehca_error_data(shca, qp, qp->ipz_qp_handle.handle);
 196
 197         if (!qp->ib_qp.event_handler)
 198                 return;
 199
 200         event.device     = &shca->ib_device;
 201         event.event      = event_type;
 202         event.element.qp = &qp->ib_qp;
 203
 204         qp->ib_qp.event_handler(&event, qp->ib_qp.qp_context);
 205
 206         return;
 207 }
 208
 209 static void cq_event_callback(struct ehca_shca *shca,
 210                                           u64 eqe)
 211 {
 212         struct ehca_cq *cq;
 213         unsigned long flags;
 214         u32 token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe);
 215
 216         spin_lock_irqsave(&ehca_cq_idr_lock, flags);
 217         cq = idr_find(&ehca_cq_idr, token);
 218         spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);
 219
 220         if (!cq)
 221                 return;
 222
 223         ehca_error_data(shca, cq, cq->ipz_cq_handle.handle);
 224
 225         return;
 226 }
 227
 228 static void parse_identifier(struct ehca_shca *shca, u64 eqe)
 229 {
 230         u8 identifier = EHCA_BMASK_GET(EQE_EE_IDENTIFIER, eqe);
 231
 232         switch (identifier) {
 233         case 0x02: /* path migrated */
 234                 qp_event_callback(shca, eqe, IB_EVENT_PATH_MIG);
 235                 break;
 236         case 0x03: /* communication established */
 237                 qp_event_callback(shca, eqe, IB_EVENT_COMM_EST);
 238                 break;
 239         case 0x04: /* send queue drained */
 240                 qp_event_callback(shca, eqe, IB_EVENT_SQ_DRAINED);
 241                 break;
 242         case 0x05: /* QP error */
 243         case 0x06: /* QP error */
 244                 qp_event_callback(shca, eqe, IB_EVENT_QP_FATAL);
 245                 break;
 246         case 0x07: /* CQ error */
 247         case 0x08: /* CQ error */
 248                 cq_event_callback(shca, eqe);
 249                 break;
 250         case 0x09: /* MRMWPTE error */
 251                 ehca_err(&shca->ib_device, "MRMWPTE error.");
 252                 break;
 253         case 0x0A: /* port event */
 254                 ehca_err(&shca->ib_device, "Port event.");
 255                 break;
 256         case 0x0B: /* MR access error */
 257                 ehca_err(&shca->ib_device, "MR access error.");
 258                 break;
 259         case 0x0C: /* EQ error */
 260                 ehca_err(&shca->ib_device, "EQ error.");
 261                 break;
 262         case 0x0D: /* P/Q_Key mismatch */
 263                 ehca_err(&shca->ib_device, "P/Q_Key mismatch.");
 264                 break;
 265         case 0x10: /* sampling complete */
 266                 ehca_err(&shca->ib_device, "Sampling complete.");
 267                 break;
 268         case 0x11: /* unaffiliated access error */
 269                 ehca_err(&shca->ib_device, "Unaffiliated access error.");
 270                 break;
 271         case 0x12: /* path migrating error */
 272                 ehca_err(&shca->ib_device, "Path migration error.");
 273                 break;
 274         case 0x13: /* interface trace stopped */
 275                 ehca_err(&shca->ib_device, "Interface trace stopped.");
 276                 break;
 277         case 0x14: /* first error capture info available */
 278         default:
 279                 ehca_err(&shca->ib_device, "Unknown identifier: %x on %s.",
 280                          identifier, shca->ib_device.name);
 281                 break;
 282         }
 283
 284         return;
 285 }
 286
 287 static void parse_ec(struct ehca_shca *shca, u64 eqe)
 288 {
 289         struct ib_event event;
 290         u8 ec   = EHCA_BMASK_GET(NEQE_EVENT_CODE, eqe);
 291         u8 port = EHCA_BMASK_GET(NEQE_PORT_NUMBER, eqe);
 292
 293         switch (ec) {
 294         case 0x30: /* port availability change */
 295                 if (EHCA_BMASK_GET(NEQE_PORT_AVAILABILITY, eqe)) {
 296                         ehca_info(&shca->ib_device,
 297                                   "port %x is active.", port);
 298                         event.device = &shca->ib_device;
 299                         event.event = IB_EVENT_PORT_ACTIVE;
 300                         event.element.port_num = port;
 301                         shca->sport[port - 1].port_state = IB_PORT_ACTIVE;
 302                         ib_dispatch_event(&event);
 303                 } else {
 304                         ehca_info(&shca->ib_device,
 305                                   "port %x is inactive.", port);
 306                         event.device = &shca->ib_device;
 307                         event.event = IB_EVENT_PORT_ERR;
 308                         event.element.port_num = port;
 309                         shca->sport[port - 1].port_state = IB_PORT_DOWN;
 310                         ib_dispatch_event(&event);
 311                 }
 312                 break;
 313         case 0x31:
 314                 /* port configuration change
 315                  * disruptive change is caused by
 316                  * LID, PKEY or SM change
 317                  */
 318                 ehca_warn(&shca->ib_device,
 319                           "disruptive port %x configuration change", port);
 320
 321                 ehca_info(&shca->ib_device,
 322                          "port %x is inactive.", port);
 323                 event.device = &shca->ib_device;
 324                 event.event = IB_EVENT_PORT_ERR;
 325                 event.element.port_num = port;
 326                 shca->sport[port - 1].port_state = IB_PORT_DOWN;
 327                 ib_dispatch_event(&event);
 328
 329                 ehca_info(&shca->ib_device,
 330                          "port %x is active.", port);
 331                 event.device = &shca->ib_device;
 332                 event.event = IB_EVENT_PORT_ACTIVE;
 333                 event.element.port_num = port;
 334                 shca->sport[port - 1].port_state = IB_PORT_ACTIVE;
 335                 ib_dispatch_event(&event);
 336                 break;
 337         case 0x32: /* adapter malfunction */
 338                 ehca_err(&shca->ib_device, "Adapter malfunction.");
 339                 break;
 340         case 0x33:  /* trace stopped */
 341                 ehca_err(&shca->ib_device, "Traced stopped.");
 342                 break;
 343         default:
 344                 ehca_err(&shca->ib_device, "Unknown event code: %x on %s.",
 345                          ec, shca->ib_device.name);
 346                 break;
 347         }
 348
 349         return;
 350 }
 351
 352 static inline void reset_eq_pending(struct ehca_cq *cq)
 353 {
 354         u64 CQx_EP;
 355         struct h_galpa gal = cq->galpas.kernel;
 356
 357         hipz_galpa_store_cq(gal, cqx_ep, 0x0);
 358         CQx_EP = hipz_galpa_load(gal, CQTEMM_OFFSET(cqx_ep));
 359
 360         return;
 361 }
 362
 363 irqreturn_t ehca_interrupt_neq(int irq, void *dev_id, struct pt_regs *regs)
 364 {
 365         struct ehca_shca *shca = (struct ehca_shca*)dev_id;
 366
 367         tasklet_hi_schedule(&shca->neq.interrupt_task);
 368
 369         return IRQ_HANDLED;
 370 }
 371
 372 void ehca_tasklet_neq(unsigned long data)
 373 {
 374         struct ehca_shca *shca = (struct ehca_shca*)data;
 375         struct ehca_eqe *eqe;
 376         u64 ret;
 377
 378         eqe = (struct ehca_eqe *)ehca_poll_eq(shca, &shca->neq);
 379
 380         while (eqe) {
 381                 if (!EHCA_BMASK_GET(NEQE_COMPLETION_EVENT, eqe->entry))
 382                         parse_ec(shca, eqe->entry);
 383
 384                 eqe = (struct ehca_eqe *)ehca_poll_eq(shca, &shca->neq);
 385         }
 386
 387         ret = hipz_h_reset_event(shca->ipz_hca_handle,
 388                                  shca->neq.ipz_eq_handle, 0xFFFFFFFFFFFFFFFFL);
 389
 390         if (ret != H_SUCCESS)
 391                 ehca_err(&shca->ib_device, "Can't clear notification events.");
 392
 393         return;
 394 }
 395
 396 irqreturn_t ehca_interrupt_eq(int irq, void *dev_id, struct pt_regs *regs)
 397 {
 398         struct ehca_shca *shca = (struct ehca_shca*)dev_id;
 399
 400         tasklet_hi_schedule(&shca->eq.interrupt_task);
 401
 402         return IRQ_HANDLED;
 403 }
 404
 405 void ehca_tasklet_eq(unsigned long data)
 406 {
 407         struct ehca_shca *shca = (struct ehca_shca*)data;
 408         struct ehca_eqe *eqe;
 409         int int_state;
 410         int query_cnt = 0;
 411
 412         do {
 413                 eqe = (struct ehca_eqe *)ehca_poll_eq(shca, &shca->eq);
 414
 415                 if ((shca->hw_level >= 2) && eqe)
 416                         int_state = 1;
 417                 else
 418                         int_state = 0;
 419
 420                 while ((int_state == 1) || eqe) {
 421                         while (eqe) {
 422                                 u64 eqe_value = eqe->entry;
 423
 424                                 ehca_dbg(&shca->ib_device,
 425                                          "eqe_value=%lx", eqe_value);
 426
 427                                 /* TODO: better structure */
 428                                 if (EHCA_BMASK_GET(EQE_COMPLETION_EVENT,
 429                                                    eqe_value)) {
 430                                         unsigned long flags;
 431                                         u32 token;
 432                                         struct ehca_cq *cq;
 433
 434                                         ehca_dbg(&shca->ib_device,
 435                                                  "... completion event");
 436                                         token =
 437                                                 EHCA_BMASK_GET(EQE_CQ_TOKEN,
 438                                                                eqe_value);
 439                                         spin_lock_irqsave(&ehca_cq_idr_lock,
 440                                                           flags);
 441                                         cq = idr_find(&ehca_cq_idr, token);
 442
 443                                         if (cq == NULL) {
 444                                                 spin_unlock(&ehca_cq_idr_lock);
 445                                                 break;
 446                                         }
 447
 448                                         reset_eq_pending(cq);
 449 #ifdef CONFIG_INFINIBAND_EHCA_SCALING
 450                                         queue_comp_task(cq);
 451                                         spin_unlock_irqrestore(&ehca_cq_idr_lock,
 452                                                                flags);
 453 #else
 454                                         spin_unlock_irqrestore(&ehca_cq_idr_lock,
 455                                                                flags);
 456                                         comp_event_callback(cq);
 457 #endif
 458                                 } else {
 459                                         ehca_dbg(&shca->ib_device,
 460                                                  "... non completion event");
 461                                         parse_identifier(shca, eqe_value);
 462                                 }
 463                                 eqe =
 464                                         (struct ehca_eqe *)ehca_poll_eq(shca,
 465                                                                     &shca->eq);
 466                         }
 467
 468                         if (shca->hw_level >= 2) {
 469                                 int_state =
 470                                     hipz_h_query_int_state(shca->ipz_hca_handle,
 471                                                            shca->eq.ist);
 472                                 query_cnt++;
 473                                 iosync();
 474                                 if (query_cnt >= 100) {
 475                                         query_cnt = 0;
 476                                         int_state = 0;
 477                                 }
 478                         }
 479                         eqe = (struct ehca_eqe *)ehca_poll_eq(shca, &shca->eq);
 480
 481                 }
 482         } while (int_state != 0);
 483
 484         return;
 485 }
 486
 487 #ifdef CONFIG_INFINIBAND_EHCA_SCALING
 488
 489 static inline int find_next_online_cpu(struct ehca_comp_pool* pool)
 490 {
 491         unsigned long flags_last_cpu;
 492
 493         if (ehca_debug_level)
 494                 ehca_dmp(&cpu_online_map, sizeof(cpumask_t), "");
 495
 496         spin_lock_irqsave(&pool->last_cpu_lock, flags_last_cpu);
 497         pool->last_cpu = next_cpu(pool->last_cpu, cpu_online_map);
 498         if (pool->last_cpu == NR_CPUS)
 499                 pool->last_cpu = first_cpu(cpu_online_map);
 500         spin_unlock_irqrestore(&pool->last_cpu_lock, flags_last_cpu);
 501
 502         return pool->last_cpu;
 503 }
 504
 505 static void __queue_comp_task(struct ehca_cq *__cq,
 506                               struct ehca_cpu_comp_task *cct)
 507 {
 508         unsigned long flags_cct;
 509         unsigned long flags_cq;
 510
 511         spin_lock_irqsave(&cct->task_lock, flags_cct);
 512         spin_lock_irqsave(&__cq->task_lock, flags_cq);
 513
 514         if (__cq->nr_callbacks == 0) {
 515                 __cq->nr_callbacks++;
 516                 list_add_tail(&__cq->entry, &cct->cq_list);
 517                 cct->cq_jobs++;
 518                 wake_up(&cct->wait_queue);
 519         }
 520         else
 521                 __cq->nr_callbacks++;
 522
 523         spin_unlock_irqrestore(&__cq->task_lock, flags_cq);
 524         spin_unlock_irqrestore(&cct->task_lock, flags_cct);
 525 }
 526
 527 static void queue_comp_task(struct ehca_cq *__cq)
 528 {
 529         int cpu;
 530         int cpu_id;
 531         struct ehca_cpu_comp_task *cct;
 532
 533         cpu = get_cpu();
 534         cpu_id = find_next_online_cpu(pool);
 535
 536         BUG_ON(!cpu_online(cpu_id));
 537
 538         cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu_id);
 539
 540         if (cct->cq_jobs > 0) {
 541                 cpu_id = find_next_online_cpu(pool);
 542                 cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu_id);
 543         }
 544
 545         __queue_comp_task(__cq, cct);
 546
 547         put_cpu();
 548
 549         return;
 550 }
 551
 552 static void run_comp_task(struct ehca_cpu_comp_task* cct)
 553 {
 554         struct ehca_cq *cq;
 555         unsigned long flags_cct;
 556         unsigned long flags_cq;
 557
 558         spin_lock_irqsave(&cct->task_lock, flags_cct);
 559
 560         while (!list_empty(&cct->cq_list)) {
 561                 cq = list_entry(cct->cq_list.next, struct ehca_cq, entry);
 562                 spin_unlock_irqrestore(&cct->task_lock, flags_cct);
 563                 comp_event_callback(cq);
 564                 spin_lock_irqsave(&cct->task_lock, flags_cct);
 565
 566                 spin_lock_irqsave(&cq->task_lock, flags_cq);
 567                 cq->nr_callbacks--;
 568                 if (cq->nr_callbacks == 0) {
 569                         list_del_init(cct->cq_list.next);
 570                         cct->cq_jobs--;
 571                 }
 572                 spin_unlock_irqrestore(&cq->task_lock, flags_cq);
 573
 574         }
 575
 576         spin_unlock_irqrestore(&cct->task_lock, flags_cct);
 577
 578         return;
 579 }
 580
 581 static int comp_task(void *__cct)
 582 {
 583         struct ehca_cpu_comp_task* cct = __cct;
 584         DECLARE_WAITQUEUE(wait, current);
 585
 586         set_current_state(TASK_INTERRUPTIBLE);
 587         while(!kthread_should_stop()) {
 588                 add_wait_queue(&cct->wait_queue, &wait);
 589
 590                 if (list_empty(&cct->cq_list))
 591                         schedule();
 592                 else
 593                         __set_current_state(TASK_RUNNING);
 594
 595                 remove_wait_queue(&cct->wait_queue, &wait);
 596
 597                 if (!list_empty(&cct->cq_list))
 598                         run_comp_task(__cct);
 599
 600                 set_current_state(TASK_INTERRUPTIBLE);
 601         }
 602         __set_current_state(TASK_RUNNING);
 603
 604         return 0;
 605 }
 606
 607 static struct task_struct *create_comp_task(struct ehca_comp_pool *pool,
 608                                             int cpu)
 609 {
 610         struct ehca_cpu_comp_task *cct;
 611
 612         cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 613         spin_lock_init(&cct->task_lock);
 614         INIT_LIST_HEAD(&cct->cq_list);
 615         init_waitqueue_head(&cct->wait_queue);
 616         cct->task = kthread_create(comp_task, cct, "ehca_comp/%d", cpu);
 617
 618         return cct->task;
 619 }
 620
 621 static void destroy_comp_task(struct ehca_comp_pool *pool,
 622                               int cpu)
 623 {
 624         struct ehca_cpu_comp_task *cct;
 625         struct task_struct *task;
 626         unsigned long flags_cct;
 627
 628         cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 629
 630         spin_lock_irqsave(&cct->task_lock, flags_cct);
 631
 632         task = cct->task;
 633         cct->task = NULL;
 634         cct->cq_jobs = 0;
 635
 636         spin_unlock_irqrestore(&cct->task_lock, flags_cct);
 637
 638         if (task)
 639                 kthread_stop(task);
 640
 641         return;
 642 }
 643
 644 static void take_over_work(struct ehca_comp_pool *pool,
 645                            int cpu)
 646 {
 647         struct ehca_cpu_comp_task *cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 648         LIST_HEAD(list);
 649         struct ehca_cq *cq;
 650         unsigned long flags_cct;
 651
 652         spin_lock_irqsave(&cct->task_lock, flags_cct);
 653
 654         list_splice_init(&cct->cq_list, &list);
 655
 656         while(!list_empty(&list)) {
 657                cq = list_entry(cct->cq_list.next, struct ehca_cq, entry);
 658
 659                list_del(&cq->entry);
 660                __queue_comp_task(cq, per_cpu_ptr(pool->cpu_comp_tasks,
 661                                                  smp_processor_id()));
 662         }
 663
 664         spin_unlock_irqrestore(&cct->task_lock, flags_cct);
 665
 666 }
 667
 668 static int comp_pool_callback(struct notifier_block *nfb,
 669                               unsigned long action,
 670                               void *hcpu)
 671 {
 672         unsigned int cpu = (unsigned long)hcpu;
 673         struct ehca_cpu_comp_task *cct;
 674
 675         switch (action) {
 676         case CPU_UP_PREPARE:
 677                 ehca_gen_dbg("CPU: %x (CPU_PREPARE)", cpu);
 678                 if(!create_comp_task(pool, cpu)) {
 679                         ehca_gen_err("Can't create comp_task for cpu: %x", cpu);
 680                         return NOTIFY_BAD;
 681                 }
 682                 break;
 683         case CPU_UP_CANCELED:
 684                 ehca_gen_dbg("CPU: %x (CPU_CANCELED)", cpu);
 685                 cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 686                 kthread_bind(cct->task, any_online_cpu(cpu_online_map));
 687                 destroy_comp_task(pool, cpu);
 688                 break;
 689         case CPU_ONLINE:
 690                 ehca_gen_dbg("CPU: %x (CPU_ONLINE)", cpu);
 691                 cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 692                 kthread_bind(cct->task, cpu);
 693                 wake_up_process(cct->task);
 694                 break;
 695         case CPU_DOWN_PREPARE:
 696                 ehca_gen_dbg("CPU: %x (CPU_DOWN_PREPARE)", cpu);
 697                 break;
 698         case CPU_DOWN_FAILED:
 699                 ehca_gen_dbg("CPU: %x (CPU_DOWN_FAILED)", cpu);
 700                 break;
 701         case CPU_DEAD:
 702                 ehca_gen_dbg("CPU: %x (CPU_DEAD)", cpu);
 703                 destroy_comp_task(pool, cpu);
 704                 take_over_work(pool, cpu);
 705                 break;
 706         }
 707
 708         return NOTIFY_OK;
 709 }
 710
 711 #endif
 712
 713 int ehca_create_comp_pool(void)
 714 {
 715 #ifdef CONFIG_INFINIBAND_EHCA_SCALING
 716         int cpu;
 717         struct task_struct *task;
 718
 719         pool = kzalloc(sizeof(struct ehca_comp_pool), GFP_KERNEL);
 720         if (pool == NULL)
 721                 return -ENOMEM;
 722
 723         spin_lock_init(&pool->last_cpu_lock);
 724         pool->last_cpu = any_online_cpu(cpu_online_map);
 725
 726         pool->cpu_comp_tasks = alloc_percpu(struct ehca_cpu_comp_task);
 727         if (pool->cpu_comp_tasks == NULL) {
 728                 kfree(pool);
 729                 return -EINVAL;
 730         }
 731
 732         for_each_online_cpu(cpu) {
 733                 task = create_comp_task(pool, cpu);
 734                 if (task) {
 735                         kthread_bind(task, cpu);
 736                         wake_up_process(task);
 737                 }
 738         }
 739
 740         comp_pool_callback_nb.notifier_call = comp_pool_callback;
 741         comp_pool_callback_nb.priority =0;
 742         register_cpu_notifier(&comp_pool_callback_nb);
 743 #endif
 744
 745         return 0;
 746 }
 747
 748 void ehca_destroy_comp_pool(void)
 749 {
 750 #ifdef CONFIG_INFINIBAND_EHCA_SCALING
 751         int i;
 752
 753         unregister_cpu_notifier(&comp_pool_callback_nb);
 754
 755         for (i = 0; i < NR_CPUS; i++) {
 756                 if (cpu_online(i))
 757                         destroy_comp_task(pool, i);
 758         }
 759 #endif
 760
 761         return;
 762 }