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 static void queue_comp_task(struct ehca_cq *__cq);
  67
  68 static struct ehca_comp_pool* pool;
  69 static struct notifier_block comp_pool_callback_nb;
  70
  71 static inline void comp_event_callback(struct ehca_cq *cq)
  72 {
  73         if (!cq->ib_cq.comp_handler)
  74                 return;
  75
  76         spin_lock(&cq->cb_lock);
  77         cq->ib_cq.comp_handler(&cq->ib_cq, cq->ib_cq.cq_context);
  78         spin_unlock(&cq->cb_lock);
  79
  80         return;
  81 }
  82
  83 static void print_error_data(struct ehca_shca * shca, void* data,
  84                              u64* rblock, int length)
  85 {
  86         u64 type = EHCA_BMASK_GET(ERROR_DATA_TYPE, rblock[2]);
  87         u64 resource = rblock[1];
  88
  89         switch (type) {
  90         case 0x1: /* Queue Pair */
  91         {
  92                 struct ehca_qp *qp = (struct ehca_qp*)data;
  93
  94                 /* only print error data if AER is set */
  95                 if (rblock[6] == 0)
  96                         return;
  97
  98                 ehca_err(&shca->ib_device,
  99                          "QP 0x%x (resource=%lx) has errors.",
 100                          qp->ib_qp.qp_num, resource);
 101                 break;
 102         }
 103         case 0x4: /* Completion Queue */
 104         {
 105                 struct ehca_cq *cq = (struct ehca_cq*)data;
 106
 107                 ehca_err(&shca->ib_device,
 108                          "CQ 0x%x (resource=%lx) has errors.",
 109                          cq->cq_number, resource);
 110                 break;
 111         }
 112         default:
 113                 ehca_err(&shca->ib_device,
 114                          "Unknown errror type: %lx on %s.",
 115                          type, shca->ib_device.name);
 116                 break;
 117         }
 118
 119         ehca_err(&shca->ib_device, "Error data is available: %lx.", resource);
 120         ehca_err(&shca->ib_device, "EHCA ----- error data begin "
 121                  "---------------------------------------------------");
 122         ehca_dmp(rblock, length, "resource=%lx", resource);
 123         ehca_err(&shca->ib_device, "EHCA ----- error data end "
 124                  "----------------------------------------------------");
 125
 126         return;
 127 }
 128
 129 int ehca_error_data(struct ehca_shca *shca, void *data,
 130                     u64 resource)
 131 {
 132
 133         unsigned long ret;
 134         u64 *rblock;
 135         unsigned long block_count;
 136
 137         rblock = ehca_alloc_fw_ctrlblock(GFP_ATOMIC);
 138         if (!rblock) {
 139                 ehca_err(&shca->ib_device, "Cannot allocate rblock memory.");
 140                 ret = -ENOMEM;
 141                 goto error_data1;
 142         }
 143
 144         /* rblock must be 4K aligned and should be 4K large */
 145         ret = hipz_h_error_data(shca->ipz_hca_handle,
 146                                 resource,
 147                                 rblock,
 148                                 &block_count);
 149
 150         if (ret == H_R_STATE)
 151                 ehca_err(&shca->ib_device,
 152                          "No error data is available: %lx.", resource);
 153         else if (ret == H_SUCCESS) {
 154                 int length;
 155
 156                 length = EHCA_BMASK_GET(ERROR_DATA_LENGTH, rblock[0]);
 157
 158                 if (length > EHCA_PAGESIZE)
 159                         length = EHCA_PAGESIZE;
 160
 161                 print_error_data(shca, data, rblock, length);
 162         } else
 163                 ehca_err(&shca->ib_device,
 164                          "Error data could not be fetched: %lx", resource);
 165
 166         ehca_free_fw_ctrlblock(rblock);
 167
 168 error_data1:
 169         return ret;
 170
 171 }
 172
 173 static void qp_event_callback(struct ehca_shca *shca,
 174                               u64 eqe,
 175                               enum ib_event_type event_type)
 176 {
 177         struct ib_event event;
 178         struct ehca_qp *qp;
 179         unsigned long flags;
 180         u32 token = EHCA_BMASK_GET(EQE_QP_TOKEN, eqe);
 181
 182         spin_lock_irqsave(&ehca_qp_idr_lock, flags);
 183         qp = idr_find(&ehca_qp_idr, token);
 184         spin_unlock_irqrestore(&ehca_qp_idr_lock, flags);
 185
 186
 187         if (!qp)
 188                 return;
 189
 190         ehca_error_data(shca, qp, qp->ipz_qp_handle.handle);
 191
 192         if (!qp->ib_qp.event_handler)
 193                 return;
 194
 195         event.device     = &shca->ib_device;
 196         event.event      = event_type;
 197         event.element.qp = &qp->ib_qp;
 198
 199         qp->ib_qp.event_handler(&event, qp->ib_qp.qp_context);
 200
 201         return;
 202 }
 203
 204 static void cq_event_callback(struct ehca_shca *shca,
 205                               u64 eqe)
 206 {
 207         struct ehca_cq *cq;
 208         unsigned long flags;
 209         u32 token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe);
 210
 211         spin_lock_irqsave(&ehca_cq_idr_lock, flags);
 212         cq = idr_find(&ehca_cq_idr, token);
 213         spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);
 214
 215         if (!cq)
 216                 return;
 217
 218         ehca_error_data(shca, cq, cq->ipz_cq_handle.handle);
 219
 220         return;
 221 }
 222
 223 static void parse_identifier(struct ehca_shca *shca, u64 eqe)
 224 {
 225         u8 identifier = EHCA_BMASK_GET(EQE_EE_IDENTIFIER, eqe);
 226
 227         switch (identifier) {
 228         case 0x02: /* path migrated */
 229                 qp_event_callback(shca, eqe, IB_EVENT_PATH_MIG);
 230                 break;
 231         case 0x03: /* communication established */
 232                 qp_event_callback(shca, eqe, IB_EVENT_COMM_EST);
 233                 break;
 234         case 0x04: /* send queue drained */
 235                 qp_event_callback(shca, eqe, IB_EVENT_SQ_DRAINED);
 236                 break;
 237         case 0x05: /* QP error */
 238         case 0x06: /* QP error */
 239                 qp_event_callback(shca, eqe, IB_EVENT_QP_FATAL);
 240                 break;
 241         case 0x07: /* CQ error */
 242         case 0x08: /* CQ error */
 243                 cq_event_callback(shca, eqe);
 244                 break;
 245         case 0x09: /* MRMWPTE error */
 246                 ehca_err(&shca->ib_device, "MRMWPTE error.");
 247                 break;
 248         case 0x0A: /* port event */
 249                 ehca_err(&shca->ib_device, "Port event.");
 250                 break;
 251         case 0x0B: /* MR access error */
 252                 ehca_err(&shca->ib_device, "MR access error.");
 253                 break;
 254         case 0x0C: /* EQ error */
 255                 ehca_err(&shca->ib_device, "EQ error.");
 256                 break;
 257         case 0x0D: /* P/Q_Key mismatch */
 258                 ehca_err(&shca->ib_device, "P/Q_Key mismatch.");
 259                 break;
 260         case 0x10: /* sampling complete */
 261                 ehca_err(&shca->ib_device, "Sampling complete.");
 262                 break;
 263         case 0x11: /* unaffiliated access error */
 264                 ehca_err(&shca->ib_device, "Unaffiliated access error.");
 265                 break;
 266         case 0x12: /* path migrating error */
 267                 ehca_err(&shca->ib_device, "Path migration error.");
 268                 break;
 269         case 0x13: /* interface trace stopped */
 270                 ehca_err(&shca->ib_device, "Interface trace stopped.");
 271                 break;
 272         case 0x14: /* first error capture info available */
 273         default:
 274                 ehca_err(&shca->ib_device, "Unknown identifier: %x on %s.",
 275                          identifier, shca->ib_device.name);
 276                 break;
 277         }
 278
 279         return;
 280 }
 281
 282 static void parse_ec(struct ehca_shca *shca, u64 eqe)
 283 {
 284         struct ib_event event;
 285         u8 ec   = EHCA_BMASK_GET(NEQE_EVENT_CODE, eqe);
 286         u8 port = EHCA_BMASK_GET(NEQE_PORT_NUMBER, eqe);
 287
 288         switch (ec) {
 289         case 0x30: /* port availability change */
 290                 if (EHCA_BMASK_GET(NEQE_PORT_AVAILABILITY, eqe)) {
 291                         ehca_info(&shca->ib_device,
 292                                   "port %x is active.", port);
 293                         event.device = &shca->ib_device;
 294                         event.event = IB_EVENT_PORT_ACTIVE;
 295                         event.element.port_num = port;
 296                         shca->sport[port - 1].port_state = IB_PORT_ACTIVE;
 297                         ib_dispatch_event(&event);
 298                 } else {
 299                         ehca_info(&shca->ib_device,
 300                                   "port %x is inactive.", port);
 301                         event.device = &shca->ib_device;
 302                         event.event = IB_EVENT_PORT_ERR;
 303                         event.element.port_num = port;
 304                         shca->sport[port - 1].port_state = IB_PORT_DOWN;
 305                         ib_dispatch_event(&event);
 306                 }
 307                 break;
 308         case 0x31:
 309                 /* port configuration change
 310                  * disruptive change is caused by
 311                  * LID, PKEY or SM change
 312                  */
 313                 ehca_warn(&shca->ib_device,
 314                           "disruptive port %x configuration change", port);
 315
 316                 ehca_info(&shca->ib_device,
 317                           "port %x is inactive.", port);
 318                 event.device = &shca->ib_device;
 319                 event.event = IB_EVENT_PORT_ERR;
 320                 event.element.port_num = port;
 321                 shca->sport[port - 1].port_state = IB_PORT_DOWN;
 322                 ib_dispatch_event(&event);
 323
 324                 ehca_info(&shca->ib_device,
 325                           "port %x is active.", port);
 326                 event.device = &shca->ib_device;
 327                 event.event = IB_EVENT_PORT_ACTIVE;
 328                 event.element.port_num = port;
 329                 shca->sport[port - 1].port_state = IB_PORT_ACTIVE;
 330                 ib_dispatch_event(&event);
 331                 break;
 332         case 0x32: /* adapter malfunction */
 333                 ehca_err(&shca->ib_device, "Adapter malfunction.");
 334                 break;
 335         case 0x33:  /* trace stopped */
 336                 ehca_err(&shca->ib_device, "Traced stopped.");
 337                 break;
 338         default:
 339                 ehca_err(&shca->ib_device, "Unknown event code: %x on %s.",
 340                          ec, shca->ib_device.name);
 341                 break;
 342         }
 343
 344         return;
 345 }
 346
 347 static inline void reset_eq_pending(struct ehca_cq *cq)
 348 {
 349         u64 CQx_EP;
 350         struct h_galpa gal = cq->galpas.kernel;
 351
 352         hipz_galpa_store_cq(gal, cqx_ep, 0x0);
 353         CQx_EP = hipz_galpa_load(gal, CQTEMM_OFFSET(cqx_ep));
 354
 355         return;
 356 }
 357
 358 irqreturn_t ehca_interrupt_neq(int irq, void *dev_id)
 359 {
 360         struct ehca_shca *shca = (struct ehca_shca*)dev_id;
 361
 362         tasklet_hi_schedule(&shca->neq.interrupt_task);
 363
 364         return IRQ_HANDLED;
 365 }
 366
 367 void ehca_tasklet_neq(unsigned long data)
 368 {
 369         struct ehca_shca *shca = (struct ehca_shca*)data;
 370         struct ehca_eqe *eqe;
 371         u64 ret;
 372
 373         eqe = (struct ehca_eqe *)ehca_poll_eq(shca, &shca->neq);
 374
 375         while (eqe) {
 376                 if (!EHCA_BMASK_GET(NEQE_COMPLETION_EVENT, eqe->entry))
 377                         parse_ec(shca, eqe->entry);
 378
 379                 eqe = (struct ehca_eqe *)ehca_poll_eq(shca, &shca->neq);
 380         }
 381
 382         ret = hipz_h_reset_event(shca->ipz_hca_handle,
 383                                  shca->neq.ipz_eq_handle, 0xFFFFFFFFFFFFFFFFL);
 384
 385         if (ret != H_SUCCESS)
 386                 ehca_err(&shca->ib_device, "Can't clear notification events.");
 387
 388         return;
 389 }
 390
 391 irqreturn_t ehca_interrupt_eq(int irq, void *dev_id)
 392 {
 393         struct ehca_shca *shca = (struct ehca_shca*)dev_id;
 394
 395         tasklet_hi_schedule(&shca->eq.interrupt_task);
 396
 397         return IRQ_HANDLED;
 398 }
 399
 400
 401 static inline void process_eqe(struct ehca_shca *shca, struct ehca_eqe *eqe)
 402 {
 403         u64 eqe_value;
 404         u32 token;
 405         unsigned long flags;
 406         struct ehca_cq *cq;
 407
 408         eqe_value = eqe->entry;
 409         ehca_dbg(&shca->ib_device, "eqe_value=%lx", eqe_value);
 410         if (EHCA_BMASK_GET(EQE_COMPLETION_EVENT, eqe_value)) {
 411                 ehca_dbg(&shca->ib_device, "Got completion event");
 412                 token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe_value);
 413                 spin_lock_irqsave(&ehca_cq_idr_lock, flags);
 414                 cq = idr_find(&ehca_cq_idr, token);
 415                 if (cq == NULL) {
 416                         spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);
 417                         ehca_err(&shca->ib_device,
 418                                  "Invalid eqe for non-existing cq token=%x",
 419                                  token);
 420                         return;
 421                 }
 422                 reset_eq_pending(cq);
 423                 cq->nr_events++;
 424                 spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);
 425                 if (ehca_scaling_code)
 426                         queue_comp_task(cq);
 427                 else {
 428                         comp_event_callback(cq);
 429                         spin_lock_irqsave(&ehca_cq_idr_lock, flags);
 430                         cq->nr_events--;
 431                         if (!cq->nr_events)
 432                                 wake_up(&cq->wait_completion);
 433                         spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);
 434                 }
 435         } else {
 436                 ehca_dbg(&shca->ib_device, "Got non completion event");
 437                 parse_identifier(shca, eqe_value);
 438         }
 439 }
 440
 441 void ehca_process_eq(struct ehca_shca *shca, int is_irq)
 442 {
 443         struct ehca_eq *eq = &shca->eq;
 444         struct ehca_eqe_cache_entry *eqe_cache = eq->eqe_cache;
 445         u64 eqe_value;
 446         unsigned long flags;
 447         int eqe_cnt, i;
 448         int eq_empty = 0;
 449
 450         spin_lock_irqsave(&eq->irq_spinlock, flags);
 451         if (is_irq) {
 452                 const int max_query_cnt = 100;
 453                 int query_cnt = 0;
 454                 int int_state = 1;
 455                 do {
 456                         int_state = hipz_h_query_int_state(
 457                                 shca->ipz_hca_handle, eq->ist);
 458                         query_cnt++;
 459                         iosync();
 460                 } while (int_state && query_cnt < max_query_cnt);
 461                 if (unlikely((query_cnt == max_query_cnt)))
 462                         ehca_dbg(&shca->ib_device, "int_state=%x query_cnt=%x",
 463                                  int_state, query_cnt);
 464         }
 465
 466         /* read out all eqes */
 467         eqe_cnt = 0;
 468         do {
 469                 u32 token;
 470                 eqe_cache[eqe_cnt].eqe =
 471                         (struct ehca_eqe *)ehca_poll_eq(shca, eq);
 472                 if (!eqe_cache[eqe_cnt].eqe)
 473                         break;
 474                 eqe_value = eqe_cache[eqe_cnt].eqe->entry;
 475                 if (EHCA_BMASK_GET(EQE_COMPLETION_EVENT, eqe_value)) {
 476                         token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe_value);
 477                         spin_lock(&ehca_cq_idr_lock);
 478                         eqe_cache[eqe_cnt].cq = idr_find(&ehca_cq_idr, token);
 479                         if (!eqe_cache[eqe_cnt].cq) {
 480                                 spin_unlock(&ehca_cq_idr_lock);
 481                                 ehca_err(&shca->ib_device,
 482                                          "Invalid eqe for non-existing cq "
 483                                          "token=%x", token);
 484                                 continue;
 485                         }
 486                         eqe_cache[eqe_cnt].cq->nr_events++;
 487                         spin_unlock(&ehca_cq_idr_lock);
 488                 } else
 489                         eqe_cache[eqe_cnt].cq = NULL;
 490                 eqe_cnt++;
 491         } while (eqe_cnt < EHCA_EQE_CACHE_SIZE);
 492         if (!eqe_cnt) {
 493                 if (is_irq)
 494                         ehca_dbg(&shca->ib_device,
 495                                  "No eqe found for irq event");
 496                 goto unlock_irq_spinlock;
 497         } else if (!is_irq)
 498                 ehca_dbg(&shca->ib_device, "deadman found %x eqe", eqe_cnt);
 499         if (unlikely(eqe_cnt == EHCA_EQE_CACHE_SIZE))
 500                 ehca_dbg(&shca->ib_device, "too many eqes for one irq event");
 501         /* enable irq for new packets */
 502         for (i = 0; i < eqe_cnt; i++) {
 503                 if (eq->eqe_cache[i].cq)
 504                         reset_eq_pending(eq->eqe_cache[i].cq);
 505         }
 506         /* check eq */
 507         spin_lock(&eq->spinlock);
 508         eq_empty = (!ipz_eqit_eq_peek_valid(&shca->eq.ipz_queue));
 509         spin_unlock(&eq->spinlock);
 510         /* call completion handler for cached eqes */
 511         for (i = 0; i < eqe_cnt; i++)
 512                 if (eq->eqe_cache[i].cq) {
 513                         if (ehca_scaling_code)
 514                                 queue_comp_task(eq->eqe_cache[i].cq);
 515                         else {
 516                                 struct ehca_cq *cq = eq->eqe_cache[i].cq;
 517                                 comp_event_callback(cq);
 518                                 spin_lock_irqsave(&ehca_cq_idr_lock, flags);
 519                                 cq->nr_events--;
 520                                 if (!cq->nr_events)
 521                                         wake_up(&cq->wait_completion);
 522                                 spin_unlock_irqrestore(&ehca_cq_idr_lock,
 523                                                        flags);
 524                         }
 525                 } else {
 526                         ehca_dbg(&shca->ib_device, "Got non completion event");
 527                         parse_identifier(shca, eq->eqe_cache[i].eqe->entry);
 528                 }
 529         /* poll eq if not empty */
 530         if (eq_empty)
 531                 goto unlock_irq_spinlock;
 532         do {
 533                 struct ehca_eqe *eqe;
 534                 eqe = (struct ehca_eqe *)ehca_poll_eq(shca, &shca->eq);
 535                 if (!eqe)
 536                         break;
 537                 process_eqe(shca, eqe);
 538         } while (1);
 539
 540 unlock_irq_spinlock:
 541         spin_unlock_irqrestore(&eq->irq_spinlock, flags);
 542 }
 543
 544 void ehca_tasklet_eq(unsigned long data)
 545 {
 546         ehca_process_eq((struct ehca_shca*)data, 1);
 547 }
 548
 549 static inline int find_next_online_cpu(struct ehca_comp_pool* pool)
 550 {
 551         int cpu;
 552         unsigned long flags;
 553
 554         WARN_ON_ONCE(!in_interrupt());
 555         if (ehca_debug_level)
 556                 ehca_dmp(&cpu_online_map, sizeof(cpumask_t), "");
 557
 558         spin_lock_irqsave(&pool->last_cpu_lock, flags);
 559         cpu = next_cpu(pool->last_cpu, cpu_online_map);
 560         if (cpu == NR_CPUS)
 561                 cpu = first_cpu(cpu_online_map);
 562         pool->last_cpu = cpu;
 563         spin_unlock_irqrestore(&pool->last_cpu_lock, flags);
 564
 565         return cpu;
 566 }
 567
 568 static void __queue_comp_task(struct ehca_cq *__cq,
 569                               struct ehca_cpu_comp_task *cct)
 570 {
 571         unsigned long flags;
 572
 573         spin_lock_irqsave(&cct->task_lock, flags);
 574         spin_lock(&__cq->task_lock);
 575
 576         if (__cq->nr_callbacks == 0) {
 577                 __cq->nr_callbacks++;
 578                 list_add_tail(&__cq->entry, &cct->cq_list);
 579                 cct->cq_jobs++;
 580                 wake_up(&cct->wait_queue);
 581         } else
 582                 __cq->nr_callbacks++;
 583
 584         spin_unlock(&__cq->task_lock);
 585         spin_unlock_irqrestore(&cct->task_lock, flags);
 586 }
 587
 588 static void queue_comp_task(struct ehca_cq *__cq)
 589 {
 590         int cpu_id;
 591         struct ehca_cpu_comp_task *cct;
 592         int cq_jobs;
 593         unsigned long flags;
 594
 595         cpu_id = find_next_online_cpu(pool);
 596         BUG_ON(!cpu_online(cpu_id));
 597
 598         cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu_id);
 599         BUG_ON(!cct);
 600
 601         spin_lock_irqsave(&cct->task_lock, flags);
 602         cq_jobs = cct->cq_jobs;
 603         spin_unlock_irqrestore(&cct->task_lock, flags);
 604         if (cq_jobs > 0) {
 605                 cpu_id = find_next_online_cpu(pool);
 606                 cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu_id);
 607                 BUG_ON(!cct);
 608         }
 609
 610         __queue_comp_task(__cq, cct);
 611 }
 612
 613 static void run_comp_task(struct ehca_cpu_comp_task* cct)
 614 {
 615         struct ehca_cq *cq;
 616         unsigned long flags;
 617
 618         spin_lock_irqsave(&cct->task_lock, flags);
 619
 620         while (!list_empty(&cct->cq_list)) {
 621                 cq = list_entry(cct->cq_list.next, struct ehca_cq, entry);
 622                 spin_unlock_irqrestore(&cct->task_lock, flags);
 623                 comp_event_callback(cq);
 624
 625                 spin_lock_irqsave(&ehca_cq_idr_lock, flags);
 626                 cq->nr_events--;
 627                 if (!cq->nr_events)
 628                         wake_up(&cq->wait_completion);
 629                 spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);
 630
 631                 spin_lock_irqsave(&cct->task_lock, flags);
 632                 spin_lock(&cq->task_lock);
 633                 cq->nr_callbacks--;
 634                 if (!cq->nr_callbacks) {
 635                         list_del_init(cct->cq_list.next);
 636                         cct->cq_jobs--;
 637                 }
 638                 spin_unlock(&cq->task_lock);
 639         }
 640
 641         spin_unlock_irqrestore(&cct->task_lock, flags);
 642 }
 643
 644 static int comp_task(void *__cct)
 645 {
 646         struct ehca_cpu_comp_task* cct = __cct;
 647         int cql_empty;
 648         DECLARE_WAITQUEUE(wait, current);
 649
 650         set_current_state(TASK_INTERRUPTIBLE);
 651         while(!kthread_should_stop()) {
 652                 add_wait_queue(&cct->wait_queue, &wait);
 653
 654                 spin_lock_irq(&cct->task_lock);
 655                 cql_empty = list_empty(&cct->cq_list);
 656                 spin_unlock_irq(&cct->task_lock);
 657                 if (cql_empty)
 658                         schedule();
 659                 else
 660                         __set_current_state(TASK_RUNNING);
 661
 662                 remove_wait_queue(&cct->wait_queue, &wait);
 663
 664                 spin_lock_irq(&cct->task_lock);
 665                 cql_empty = list_empty(&cct->cq_list);
 666                 spin_unlock_irq(&cct->task_lock);
 667                 if (!cql_empty)
 668                         run_comp_task(__cct);
 669
 670                 set_current_state(TASK_INTERRUPTIBLE);
 671         }
 672         __set_current_state(TASK_RUNNING);
 673
 674         return 0;
 675 }
 676
 677 static struct task_struct *create_comp_task(struct ehca_comp_pool *pool,
 678                                             int cpu)
 679 {
 680         struct ehca_cpu_comp_task *cct;
 681
 682         cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 683         spin_lock_init(&cct->task_lock);
 684         INIT_LIST_HEAD(&cct->cq_list);
 685         init_waitqueue_head(&cct->wait_queue);
 686         cct->task = kthread_create(comp_task, cct, "ehca_comp/%d", cpu);
 687
 688         return cct->task;
 689 }
 690
 691 static void destroy_comp_task(struct ehca_comp_pool *pool,
 692                               int cpu)
 693 {
 694         struct ehca_cpu_comp_task *cct;
 695         struct task_struct *task;
 696         unsigned long flags_cct;
 697
 698         cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 699
 700         spin_lock_irqsave(&cct->task_lock, flags_cct);
 701
 702         task = cct->task;
 703         cct->task = NULL;
 704         cct->cq_jobs = 0;
 705
 706         spin_unlock_irqrestore(&cct->task_lock, flags_cct);
 707
 708         if (task)
 709                 kthread_stop(task);
 710 }
 711
 712 static void take_over_work(struct ehca_comp_pool *pool,
 713                            int cpu)
 714 {
 715         struct ehca_cpu_comp_task *cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 716         LIST_HEAD(list);
 717         struct ehca_cq *cq;
 718         unsigned long flags_cct;
 719
 720         spin_lock_irqsave(&cct->task_lock, flags_cct);
 721
 722         list_splice_init(&cct->cq_list, &list);
 723
 724         while(!list_empty(&list)) {
 725                 cq = list_entry(cct->cq_list.next, struct ehca_cq, entry);
 726
 727                 list_del(&cq->entry);
 728                 __queue_comp_task(cq, per_cpu_ptr(pool->cpu_comp_tasks,
 729                                                   smp_processor_id()));
 730         }
 731
 732         spin_unlock_irqrestore(&cct->task_lock, flags_cct);
 733
 734 }
 735
 736 static int comp_pool_callback(struct notifier_block *nfb,
 737                               unsigned long action,
 738                               void *hcpu)
 739 {
 740         unsigned int cpu = (unsigned long)hcpu;
 741         struct ehca_cpu_comp_task *cct;
 742
 743         switch (action) {
 744         case CPU_UP_PREPARE:
 745                 ehca_gen_dbg("CPU: %x (CPU_PREPARE)", cpu);
 746                 if(!create_comp_task(pool, cpu)) {
 747                         ehca_gen_err("Can't create comp_task for cpu: %x", cpu);
 748                         return NOTIFY_BAD;
 749                 }
 750                 break;
 751         case CPU_UP_CANCELED:
 752                 ehca_gen_dbg("CPU: %x (CPU_CANCELED)", cpu);
 753                 cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 754                 kthread_bind(cct->task, any_online_cpu(cpu_online_map));
 755                 destroy_comp_task(pool, cpu);
 756                 break;
 757         case CPU_ONLINE:
 758                 ehca_gen_dbg("CPU: %x (CPU_ONLINE)", cpu);
 759                 cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 760                 kthread_bind(cct->task, cpu);
 761                 wake_up_process(cct->task);
 762                 break;
 763         case CPU_DOWN_PREPARE:
 764                 ehca_gen_dbg("CPU: %x (CPU_DOWN_PREPARE)", cpu);
 765                 break;
 766         case CPU_DOWN_FAILED:
 767                 ehca_gen_dbg("CPU: %x (CPU_DOWN_FAILED)", cpu);
 768                 break;
 769         case CPU_DEAD:
 770                 ehca_gen_dbg("CPU: %x (CPU_DEAD)", cpu);
 771                 destroy_comp_task(pool, cpu);
 772                 take_over_work(pool, cpu);
 773                 break;
 774         }
 775
 776         return NOTIFY_OK;
 777 }
 778
 779 int ehca_create_comp_pool(void)
 780 {
 781         int cpu;
 782         struct task_struct *task;
 783
 784         if (!ehca_scaling_code)
 785                 return 0;
 786
 787         pool = kzalloc(sizeof(struct ehca_comp_pool), GFP_KERNEL);
 788         if (pool == NULL)
 789                 return -ENOMEM;
 790
 791         spin_lock_init(&pool->last_cpu_lock);
 792         pool->last_cpu = any_online_cpu(cpu_online_map);
 793
 794         pool->cpu_comp_tasks = alloc_percpu(struct ehca_cpu_comp_task);
 795         if (pool->cpu_comp_tasks == NULL) {
 796                 kfree(pool);
 797                 return -EINVAL;
 798         }
 799
 800         for_each_online_cpu(cpu) {
 801                 task = create_comp_task(pool, cpu);
 802                 if (task) {
 803                         kthread_bind(task, cpu);
 804                         wake_up_process(task);
 805                 }
 806         }
 807
 808         comp_pool_callback_nb.notifier_call = comp_pool_callback;
 809         comp_pool_callback_nb.priority =0;
 810         register_cpu_notifier(&comp_pool_callback_nb);
 811
 812         printk(KERN_INFO "eHCA scaling code enabled\n");
 813
 814         return 0;
 815 }
 816
 817 void ehca_destroy_comp_pool(void)
 818 {
 819         int i;
 820
 821         if (!ehca_scaling_code)
 822                 return;
 823
 824         unregister_cpu_notifier(&comp_pool_callback_nb);
 825
 826         for (i = 0; i < NR_CPUS; i++) {
 827                 if (cpu_online(i))
 828                         destroy_comp_task(pool, i);
 829         }
 830         free_percpu(pool->cpu_comp_tasks);
 831         kfree(pool);
 832 }