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 #include "ipz_pt_fn.h"
  49
  50 #define EQE_COMPLETION_EVENT   EHCA_BMASK_IBM(1,1)
  51 #define EQE_CQ_QP_NUMBER       EHCA_BMASK_IBM(8,31)
  52 #define EQE_EE_IDENTIFIER      EHCA_BMASK_IBM(2,7)
  53 #define EQE_CQ_NUMBER          EHCA_BMASK_IBM(8,31)
  54 #define EQE_QP_NUMBER          EHCA_BMASK_IBM(8,31)
  55 #define EQE_QP_TOKEN           EHCA_BMASK_IBM(32,63)
  56 #define EQE_CQ_TOKEN           EHCA_BMASK_IBM(32,63)
  57
  58 #define NEQE_COMPLETION_EVENT  EHCA_BMASK_IBM(1,1)
  59 #define NEQE_EVENT_CODE        EHCA_BMASK_IBM(2,7)
  60 #define NEQE_PORT_NUMBER       EHCA_BMASK_IBM(8,15)
  61 #define NEQE_PORT_AVAILABILITY EHCA_BMASK_IBM(16,16)
  62
  63 #define ERROR_DATA_LENGTH      EHCA_BMASK_IBM(52,63)
  64 #define ERROR_DATA_TYPE        EHCA_BMASK_IBM(0,7)
  65
  66 #ifdef CONFIG_INFINIBAND_EHCA_SCALING
  67
  68 static void queue_comp_task(struct ehca_cq *__cq);
  69
  70 static struct ehca_comp_pool* pool;
  71 static struct notifier_block comp_pool_callback_nb;
  72
  73 #endif
  74
  75 static inline void comp_event_callback(struct ehca_cq *cq)
  76 {
  77         if (!cq->ib_cq.comp_handler)
  78                 return;
  79
  80         spin_lock(&cq->cb_lock);
  81         cq->ib_cq.comp_handler(&cq->ib_cq, cq->ib_cq.cq_context);
  82         spin_unlock(&cq->cb_lock);
  83
  84         return;
  85 }
  86
  87 static void print_error_data(struct ehca_shca * shca, void* data,
  88                              u64* rblock, int length)
  89 {
  90         u64 type = EHCA_BMASK_GET(ERROR_DATA_TYPE, rblock[2]);
  91         u64 resource = rblock[1];
  92
  93         switch (type) {
  94         case 0x1: /* Queue Pair */
  95         {
  96                 struct ehca_qp *qp = (struct ehca_qp*)data;
  97
  98                 /* only print error data if AER is set */
  99                 if (rblock[6] == 0)
 100                         return;
 101
 102                 ehca_err(&shca->ib_device,
 103                          "QP 0x%x (resource=%lx) has errors.",
 104                          qp->ib_qp.qp_num, resource);
 105                 break;
 106         }
 107         case 0x4: /* Completion Queue */
 108         {
 109                 struct ehca_cq *cq = (struct ehca_cq*)data;
 110
 111                 ehca_err(&shca->ib_device,
 112                          "CQ 0x%x (resource=%lx) has errors.",
 113                          cq->cq_number, resource);
 114                 break;
 115         }
 116         default:
 117                 ehca_err(&shca->ib_device,
 118                          "Unknown errror type: %lx on %s.",
 119                          type, shca->ib_device.name);
 120                 break;
 121         }
 122
 123         ehca_err(&shca->ib_device, "Error data is available: %lx.", resource);
 124         ehca_err(&shca->ib_device, "EHCA ----- error data begin "
 125                  "---------------------------------------------------");
 126         ehca_dmp(rblock, length, "resource=%lx", resource);
 127         ehca_err(&shca->ib_device, "EHCA ----- error data end "
 128                  "----------------------------------------------------");
 129
 130         return;
 131 }
 132
 133 int ehca_error_data(struct ehca_shca *shca, void *data,
 134                     u64 resource)
 135 {
 136
 137         unsigned long ret;
 138         u64 *rblock;
 139         unsigned long block_count;
 140
 141         rblock = ehca_alloc_fw_ctrlblock(GFP_ATOMIC);
 142         if (!rblock) {
 143                 ehca_err(&shca->ib_device, "Cannot allocate rblock memory.");
 144                 ret = -ENOMEM;
 145                 goto error_data1;
 146         }
 147
 148         /* rblock must be 4K aligned and should be 4K large */
 149         ret = hipz_h_error_data(shca->ipz_hca_handle,
 150                                 resource,
 151                                 rblock,
 152                                 &block_count);
 153
 154         if (ret == H_R_STATE)
 155                 ehca_err(&shca->ib_device,
 156                          "No error data is available: %lx.", resource);
 157         else if (ret == H_SUCCESS) {
 158                 int length;
 159
 160                 length = EHCA_BMASK_GET(ERROR_DATA_LENGTH, rblock[0]);
 161
 162                 if (length > EHCA_PAGESIZE)
 163                         length = EHCA_PAGESIZE;
 164
 165                 print_error_data(shca, data, rblock, length);
 166         } else
 167                 ehca_err(&shca->ib_device,
 168                          "Error data could not be fetched: %lx", resource);
 169
 170         ehca_free_fw_ctrlblock(rblock);
 171
 172 error_data1:
 173         return ret;
 174
 175 }
 176
 177 static void qp_event_callback(struct ehca_shca *shca,
 178                               u64 eqe,
 179                               enum ib_event_type event_type)
 180 {
 181         struct ib_event event;
 182         struct ehca_qp *qp;
 183         unsigned long flags;
 184         u32 token = EHCA_BMASK_GET(EQE_QP_TOKEN, eqe);
 185
 186         spin_lock_irqsave(&ehca_qp_idr_lock, flags);
 187         qp = idr_find(&ehca_qp_idr, token);
 188         spin_unlock_irqrestore(&ehca_qp_idr_lock, flags);
 189
 190
 191         if (!qp)
 192                 return;
 193
 194         ehca_error_data(shca, qp, qp->ipz_qp_handle.handle);
 195
 196         if (!qp->ib_qp.event_handler)
 197                 return;
 198
 199         event.device     = &shca->ib_device;
 200         event.event      = event_type;
 201         event.element.qp = &qp->ib_qp;
 202
 203         qp->ib_qp.event_handler(&event, qp->ib_qp.qp_context);
 204
 205         return;
 206 }
 207
 208 static void cq_event_callback(struct ehca_shca *shca,
 209                                           u64 eqe)
 210 {
 211         struct ehca_cq *cq;
 212         unsigned long flags;
 213         u32 token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe);
 214
 215         spin_lock_irqsave(&ehca_cq_idr_lock, flags);
 216         cq = idr_find(&ehca_cq_idr, token);
 217         spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);
 218
 219         if (!cq)
 220                 return;
 221
 222         ehca_error_data(shca, cq, cq->ipz_cq_handle.handle);
 223
 224         return;
 225 }
 226
 227 static void parse_identifier(struct ehca_shca *shca, u64 eqe)
 228 {
 229         u8 identifier = EHCA_BMASK_GET(EQE_EE_IDENTIFIER, eqe);
 230
 231         switch (identifier) {
 232         case 0x02: /* path migrated */
 233                 qp_event_callback(shca, eqe, IB_EVENT_PATH_MIG);
 234                 break;
 235         case 0x03: /* communication established */
 236                 qp_event_callback(shca, eqe, IB_EVENT_COMM_EST);
 237                 break;
 238         case 0x04: /* send queue drained */
 239                 qp_event_callback(shca, eqe, IB_EVENT_SQ_DRAINED);
 240                 break;
 241         case 0x05: /* QP error */
 242         case 0x06: /* QP error */
 243                 qp_event_callback(shca, eqe, IB_EVENT_QP_FATAL);
 244                 break;
 245         case 0x07: /* CQ error */
 246         case 0x08: /* CQ error */
 247                 cq_event_callback(shca, eqe);
 248                 break;
 249         case 0x09: /* MRMWPTE error */
 250                 ehca_err(&shca->ib_device, "MRMWPTE error.");
 251                 break;
 252         case 0x0A: /* port event */
 253                 ehca_err(&shca->ib_device, "Port event.");
 254                 break;
 255         case 0x0B: /* MR access error */
 256                 ehca_err(&shca->ib_device, "MR access error.");
 257                 break;
 258         case 0x0C: /* EQ error */
 259                 ehca_err(&shca->ib_device, "EQ error.");
 260                 break;
 261         case 0x0D: /* P/Q_Key mismatch */
 262                 ehca_err(&shca->ib_device, "P/Q_Key mismatch.");
 263                 break;
 264         case 0x10: /* sampling complete */
 265                 ehca_err(&shca->ib_device, "Sampling complete.");
 266                 break;
 267         case 0x11: /* unaffiliated access error */
 268                 ehca_err(&shca->ib_device, "Unaffiliated access error.");
 269                 break;
 270         case 0x12: /* path migrating error */
 271                 ehca_err(&shca->ib_device, "Path migration error.");
 272                 break;
 273         case 0x13: /* interface trace stopped */
 274                 ehca_err(&shca->ib_device, "Interface trace stopped.");
 275                 break;
 276         case 0x14: /* first error capture info available */
 277         default:
 278                 ehca_err(&shca->ib_device, "Unknown identifier: %x on %s.",
 279                          identifier, shca->ib_device.name);
 280                 break;
 281         }
 282
 283         return;
 284 }
 285
 286 static void parse_ec(struct ehca_shca *shca, u64 eqe)
 287 {
 288         struct ib_event event;
 289         u8 ec   = EHCA_BMASK_GET(NEQE_EVENT_CODE, eqe);
 290         u8 port = EHCA_BMASK_GET(NEQE_PORT_NUMBER, eqe);
 291
 292         switch (ec) {
 293         case 0x30: /* port availability change */
 294                 if (EHCA_BMASK_GET(NEQE_PORT_AVAILABILITY, eqe)) {
 295                         ehca_info(&shca->ib_device,
 296                                   "port %x is active.", port);
 297                         event.device = &shca->ib_device;
 298                         event.event = IB_EVENT_PORT_ACTIVE;
 299                         event.element.port_num = port;
 300                         shca->sport[port - 1].port_state = IB_PORT_ACTIVE;
 301                         ib_dispatch_event(&event);
 302                 } else {
 303                         ehca_info(&shca->ib_device,
 304                                   "port %x is inactive.", port);
 305                         event.device = &shca->ib_device;
 306                         event.event = IB_EVENT_PORT_ERR;
 307                         event.element.port_num = port;
 308                         shca->sport[port - 1].port_state = IB_PORT_DOWN;
 309                         ib_dispatch_event(&event);
 310                 }
 311                 break;
 312         case 0x31:
 313                 /* port configuration change
 314                  * disruptive change is caused by
 315                  * LID, PKEY or SM change
 316                  */
 317                 ehca_warn(&shca->ib_device,
 318                           "disruptive port %x configuration change", port);
 319
 320                 ehca_info(&shca->ib_device,
 321                          "port %x is inactive.", port);
 322                 event.device = &shca->ib_device;
 323                 event.event = IB_EVENT_PORT_ERR;
 324                 event.element.port_num = port;
 325                 shca->sport[port - 1].port_state = IB_PORT_DOWN;
 326                 ib_dispatch_event(&event);
 327
 328                 ehca_info(&shca->ib_device,
 329                          "port %x is active.", port);
 330                 event.device = &shca->ib_device;
 331                 event.event = IB_EVENT_PORT_ACTIVE;
 332                 event.element.port_num = port;
 333                 shca->sport[port - 1].port_state = IB_PORT_ACTIVE;
 334                 ib_dispatch_event(&event);
 335                 break;
 336         case 0x32: /* adapter malfunction */
 337                 ehca_err(&shca->ib_device, "Adapter malfunction.");
 338                 break;
 339         case 0x33:  /* trace stopped */
 340                 ehca_err(&shca->ib_device, "Traced stopped.");
 341                 break;
 342         default:
 343                 ehca_err(&shca->ib_device, "Unknown event code: %x on %s.",
 344                          ec, shca->ib_device.name);
 345                 break;
 346         }
 347
 348         return;
 349 }
 350
 351 static inline void reset_eq_pending(struct ehca_cq *cq)
 352 {
 353         u64 CQx_EP;
 354         struct h_galpa gal = cq->galpas.kernel;
 355
 356         hipz_galpa_store_cq(gal, cqx_ep, 0x0);
 357         CQx_EP = hipz_galpa_load(gal, CQTEMM_OFFSET(cqx_ep));
 358
 359         return;
 360 }
 361
 362 irqreturn_t ehca_interrupt_neq(int irq, void *dev_id)
 363 {
 364         struct ehca_shca *shca = (struct ehca_shca*)dev_id;
 365
 366         tasklet_hi_schedule(&shca->neq.interrupt_task);
 367
 368         return IRQ_HANDLED;
 369 }
 370
 371 void ehca_tasklet_neq(unsigned long data)
 372 {
 373         struct ehca_shca *shca = (struct ehca_shca*)data;
 374         struct ehca_eqe *eqe;
 375         u64 ret;
 376
 377         eqe = (struct ehca_eqe *)ehca_poll_eq(shca, &shca->neq);
 378
 379         while (eqe) {
 380                 if (!EHCA_BMASK_GET(NEQE_COMPLETION_EVENT, eqe->entry))
 381                         parse_ec(shca, eqe->entry);
 382
 383                 eqe = (struct ehca_eqe *)ehca_poll_eq(shca, &shca->neq);
 384         }
 385
 386         ret = hipz_h_reset_event(shca->ipz_hca_handle,
 387                                  shca->neq.ipz_eq_handle, 0xFFFFFFFFFFFFFFFFL);
 388
 389         if (ret != H_SUCCESS)
 390                 ehca_err(&shca->ib_device, "Can't clear notification events.");
 391
 392         return;
 393 }
 394
 395 irqreturn_t ehca_interrupt_eq(int irq, void *dev_id)
 396 {
 397         struct ehca_shca *shca = (struct ehca_shca*)dev_id;
 398
 399         tasklet_hi_schedule(&shca->eq.interrupt_task);
 400
 401         return IRQ_HANDLED;
 402 }
 403
 404 void ehca_tasklet_eq(unsigned long data)
 405 {
 406         struct ehca_shca *shca = (struct ehca_shca*)data;
 407         struct ehca_eqe *eqe;
 408         int int_state;
 409         int query_cnt = 0;
 410
 411         do {
 412                 eqe = (struct ehca_eqe *)ehca_poll_eq(shca, &shca->eq);
 413
 414                 if ((shca->hw_level >= 2) && eqe)
 415                         int_state = 1;
 416                 else
 417                         int_state = 0;
 418
 419                 while ((int_state == 1) || eqe) {
 420                         while (eqe) {
 421                                 u64 eqe_value = eqe->entry;
 422
 423                                 ehca_dbg(&shca->ib_device,
 424                                          "eqe_value=%lx", eqe_value);
 425
 426                                 /* TODO: better structure */
 427                                 if (EHCA_BMASK_GET(EQE_COMPLETION_EVENT,
 428                                                    eqe_value)) {
 429                                         unsigned long flags;
 430                                         u32 token;
 431                                         struct ehca_cq *cq;
 432
 433                                         ehca_dbg(&shca->ib_device,
 434                                                  "... completion event");
 435                                         token =
 436                                                 EHCA_BMASK_GET(EQE_CQ_TOKEN,
 437                                                                eqe_value);
 438                                         spin_lock_irqsave(&ehca_cq_idr_lock,
 439                                                           flags);
 440                                         cq = idr_find(&ehca_cq_idr, token);
 441
 442                                         if (cq == NULL) {
 443                                                 spin_unlock(&ehca_cq_idr_lock);
 444                                                 break;
 445                                         }
 446
 447                                         reset_eq_pending(cq);
 448 #ifdef CONFIG_INFINIBAND_EHCA_SCALING
 449                                         queue_comp_task(cq);
 450                                         spin_unlock_irqrestore(&ehca_cq_idr_lock,
 451                                                                flags);
 452 #else
 453                                         spin_unlock_irqrestore(&ehca_cq_idr_lock,
 454                                                                flags);
 455                                         comp_event_callback(cq);
 456 #endif
 457                                 } else {
 458                                         ehca_dbg(&shca->ib_device,
 459                                                  "... non completion event");
 460                                         parse_identifier(shca, eqe_value);
 461                                 }
 462                                 eqe =
 463                                         (struct ehca_eqe *)ehca_poll_eq(shca,
 464                                                                     &shca->eq);
 465                         }
 466
 467                         if (shca->hw_level >= 2) {
 468                                 int_state =
 469                                     hipz_h_query_int_state(shca->ipz_hca_handle,
 470                                                            shca->eq.ist);
 471                                 query_cnt++;
 472                                 iosync();
 473                                 if (query_cnt >= 100) {
 474                                         query_cnt = 0;
 475                                         int_state = 0;
 476                                 }
 477                         }
 478                         eqe = (struct ehca_eqe *)ehca_poll_eq(shca, &shca->eq);
 479
 480                 }
 481         } while (int_state != 0);
 482
 483         return;
 484 }
 485
 486 #ifdef CONFIG_INFINIBAND_EHCA_SCALING
 487
 488 static inline int find_next_online_cpu(struct ehca_comp_pool* pool)
 489 {
 490         unsigned long flags_last_cpu;
 491
 492         if (ehca_debug_level)
 493                 ehca_dmp(&cpu_online_map, sizeof(cpumask_t), "");
 494
 495         spin_lock_irqsave(&pool->last_cpu_lock, flags_last_cpu);
 496         pool->last_cpu = next_cpu(pool->last_cpu, cpu_online_map);
 497         if (pool->last_cpu == NR_CPUS)
 498                 pool->last_cpu = first_cpu(cpu_online_map);
 499         spin_unlock_irqrestore(&pool->last_cpu_lock, flags_last_cpu);
 500
 501         return pool->last_cpu;
 502 }
 503
 504 static void __queue_comp_task(struct ehca_cq *__cq,
 505                               struct ehca_cpu_comp_task *cct)
 506 {
 507         unsigned long flags_cct;
 508         unsigned long flags_cq;
 509
 510         spin_lock_irqsave(&cct->task_lock, flags_cct);
 511         spin_lock_irqsave(&__cq->task_lock, flags_cq);
 512
 513         if (__cq->nr_callbacks == 0) {
 514                 __cq->nr_callbacks++;
 515                 list_add_tail(&__cq->entry, &cct->cq_list);
 516                 cct->cq_jobs++;
 517                 wake_up(&cct->wait_queue);
 518         }
 519         else
 520                 __cq->nr_callbacks++;
 521
 522         spin_unlock_irqrestore(&__cq->task_lock, flags_cq);
 523         spin_unlock_irqrestore(&cct->task_lock, flags_cct);
 524 }
 525
 526 static void queue_comp_task(struct ehca_cq *__cq)
 527 {
 528         int cpu;
 529         int cpu_id;
 530         struct ehca_cpu_comp_task *cct;
 531
 532         cpu = get_cpu();
 533         cpu_id = find_next_online_cpu(pool);
 534
 535         BUG_ON(!cpu_online(cpu_id));
 536
 537         cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu_id);
 538
 539         if (cct->cq_jobs > 0) {
 540                 cpu_id = find_next_online_cpu(pool);
 541                 cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu_id);
 542         }
 543
 544         __queue_comp_task(__cq, cct);
 545
 546         put_cpu();
 547
 548         return;
 549 }
 550
 551 static void run_comp_task(struct ehca_cpu_comp_task* cct)
 552 {
 553         struct ehca_cq *cq;
 554         unsigned long flags_cct;
 555         unsigned long flags_cq;
 556
 557         spin_lock_irqsave(&cct->task_lock, flags_cct);
 558
 559         while (!list_empty(&cct->cq_list)) {
 560                 cq = list_entry(cct->cq_list.next, struct ehca_cq, entry);
 561                 spin_unlock_irqrestore(&cct->task_lock, flags_cct);
 562                 comp_event_callback(cq);
 563                 spin_lock_irqsave(&cct->task_lock, flags_cct);
 564
 565                 spin_lock_irqsave(&cq->task_lock, flags_cq);
 566                 cq->nr_callbacks--;
 567                 if (cq->nr_callbacks == 0) {
 568                         list_del_init(cct->cq_list.next);
 569                         cct->cq_jobs--;
 570                 }
 571                 spin_unlock_irqrestore(&cq->task_lock, flags_cq);
 572
 573         }
 574
 575         spin_unlock_irqrestore(&cct->task_lock, flags_cct);
 576
 577         return;
 578 }
 579
 580 static int comp_task(void *__cct)
 581 {
 582         struct ehca_cpu_comp_task* cct = __cct;
 583         DECLARE_WAITQUEUE(wait, current);
 584
 585         set_current_state(TASK_INTERRUPTIBLE);
 586         while(!kthread_should_stop()) {
 587                 add_wait_queue(&cct->wait_queue, &wait);
 588
 589                 if (list_empty(&cct->cq_list))
 590                         schedule();
 591                 else
 592                         __set_current_state(TASK_RUNNING);
 593
 594                 remove_wait_queue(&cct->wait_queue, &wait);
 595
 596                 if (!list_empty(&cct->cq_list))
 597                         run_comp_task(__cct);
 598
 599                 set_current_state(TASK_INTERRUPTIBLE);
 600         }
 601         __set_current_state(TASK_RUNNING);
 602
 603         return 0;
 604 }
 605
 606 static struct task_struct *create_comp_task(struct ehca_comp_pool *pool,
 607                                             int cpu)
 608 {
 609         struct ehca_cpu_comp_task *cct;
 610
 611         cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 612         spin_lock_init(&cct->task_lock);
 613         INIT_LIST_HEAD(&cct->cq_list);
 614         init_waitqueue_head(&cct->wait_queue);
 615         cct->task = kthread_create(comp_task, cct, "ehca_comp/%d", cpu);
 616
 617         return cct->task;
 618 }
 619
 620 static void destroy_comp_task(struct ehca_comp_pool *pool,
 621                               int cpu)
 622 {
 623         struct ehca_cpu_comp_task *cct;
 624         struct task_struct *task;
 625         unsigned long flags_cct;
 626
 627         cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 628
 629         spin_lock_irqsave(&cct->task_lock, flags_cct);
 630
 631         task = cct->task;
 632         cct->task = NULL;
 633         cct->cq_jobs = 0;
 634
 635         spin_unlock_irqrestore(&cct->task_lock, flags_cct);
 636
 637         if (task)
 638                 kthread_stop(task);
 639
 640         return;
 641 }
 642
 643 static void take_over_work(struct ehca_comp_pool *pool,
 644                            int cpu)
 645 {
 646         struct ehca_cpu_comp_task *cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 647         LIST_HEAD(list);
 648         struct ehca_cq *cq;
 649         unsigned long flags_cct;
 650
 651         spin_lock_irqsave(&cct->task_lock, flags_cct);
 652
 653         list_splice_init(&cct->cq_list, &list);
 654
 655         while(!list_empty(&list)) {
 656                cq = list_entry(cct->cq_list.next, struct ehca_cq, entry);
 657
 658                list_del(&cq->entry);
 659                __queue_comp_task(cq, per_cpu_ptr(pool->cpu_comp_tasks,
 660                                                  smp_processor_id()));
 661         }
 662
 663         spin_unlock_irqrestore(&cct->task_lock, flags_cct);
 664
 665 }
 666
 667 static int comp_pool_callback(struct notifier_block *nfb,
 668                               unsigned long action,
 669                               void *hcpu)
 670 {
 671         unsigned int cpu = (unsigned long)hcpu;
 672         struct ehca_cpu_comp_task *cct;
 673
 674         switch (action) {
 675         case CPU_UP_PREPARE:
 676                 ehca_gen_dbg("CPU: %x (CPU_PREPARE)", cpu);
 677                 if(!create_comp_task(pool, cpu)) {
 678                         ehca_gen_err("Can't create comp_task for cpu: %x", cpu);
 679                         return NOTIFY_BAD;
 680                 }
 681                 break;
 682         case CPU_UP_CANCELED:
 683                 ehca_gen_dbg("CPU: %x (CPU_CANCELED)", cpu);
 684                 cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 685                 kthread_bind(cct->task, any_online_cpu(cpu_online_map));
 686                 destroy_comp_task(pool, cpu);
 687                 break;
 688         case CPU_ONLINE:
 689                 ehca_gen_dbg("CPU: %x (CPU_ONLINE)", cpu);
 690                 cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 691                 kthread_bind(cct->task, cpu);
 692                 wake_up_process(cct->task);
 693                 break;
 694         case CPU_DOWN_PREPARE:
 695                 ehca_gen_dbg("CPU: %x (CPU_DOWN_PREPARE)", cpu);
 696                 break;
 697         case CPU_DOWN_FAILED:
 698                 ehca_gen_dbg("CPU: %x (CPU_DOWN_FAILED)", cpu);
 699                 break;
 700         case CPU_DEAD:
 701                 ehca_gen_dbg("CPU: %x (CPU_DEAD)", cpu);
 702                 destroy_comp_task(pool, cpu);
 703                 take_over_work(pool, cpu);
 704                 break;
 705         }
 706
 707         return NOTIFY_OK;
 708 }
 709
 710 #endif
 711
 712 int ehca_create_comp_pool(void)
 713 {
 714 #ifdef CONFIG_INFINIBAND_EHCA_SCALING
 715         int cpu;
 716         struct task_struct *task;
 717
 718         pool = kzalloc(sizeof(struct ehca_comp_pool), GFP_KERNEL);
 719         if (pool == NULL)
 720                 return -ENOMEM;
 721
 722         spin_lock_init(&pool->last_cpu_lock);
 723         pool->last_cpu = any_online_cpu(cpu_online_map);
 724
 725         pool->cpu_comp_tasks = alloc_percpu(struct ehca_cpu_comp_task);
 726         if (pool->cpu_comp_tasks == NULL) {
 727                 kfree(pool);
 728                 return -EINVAL;
 729         }
 730
 731         for_each_online_cpu(cpu) {
 732                 task = create_comp_task(pool, cpu);
 733                 if (task) {
 734                         kthread_bind(task, cpu);
 735                         wake_up_process(task);
 736                 }
 737         }
 738
 739         comp_pool_callback_nb.notifier_call = comp_pool_callback;
 740         comp_pool_callback_nb.priority =0;
 741         register_cpu_notifier(&comp_pool_callback_nb);
 742 #endif
 743
 744         return 0;
 745 }
 746
 747 void ehca_destroy_comp_pool(void)
 748 {
 749 #ifdef CONFIG_INFINIBAND_EHCA_SCALING
 750         int i;
 751
 752         unregister_cpu_notifier(&comp_pool_callback_nb);
 753
 754         for (i = 0; i < NR_CPUS; i++) {
 755                 if (cpu_online(i))
 756                         destroy_comp_task(pool, i);
 757         }
 758 #endif
 759
 760         return;
 761 }