linux/drivers/infiniband/hw/ehca/ehca_irq.c
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   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 "ehca_classes.h"
  45#include "ehca_irq.h"
  46#include "ehca_iverbs.h"
  47#include "ehca_tools.h"
  48#include "hcp_if.h"
  49#include "hipz_fns.h"
  50#include "ipz_pt_fn.h"
  51
  52#define EQE_COMPLETION_EVENT   EHCA_BMASK_IBM( 1,  1)
  53#define EQE_CQ_QP_NUMBER       EHCA_BMASK_IBM( 8, 31)
  54#define EQE_EE_IDENTIFIER      EHCA_BMASK_IBM( 2,  7)
  55#define EQE_CQ_NUMBER          EHCA_BMASK_IBM( 8, 31)
  56#define EQE_QP_NUMBER          EHCA_BMASK_IBM( 8, 31)
  57#define EQE_QP_TOKEN           EHCA_BMASK_IBM(32, 63)
  58#define EQE_CQ_TOKEN           EHCA_BMASK_IBM(32, 63)
  59
  60#define NEQE_COMPLETION_EVENT  EHCA_BMASK_IBM( 1,  1)
  61#define NEQE_EVENT_CODE        EHCA_BMASK_IBM( 2,  7)
  62#define NEQE_PORT_NUMBER       EHCA_BMASK_IBM( 8, 15)
  63#define NEQE_PORT_AVAILABILITY EHCA_BMASK_IBM(16, 16)
  64#define NEQE_DISRUPTIVE        EHCA_BMASK_IBM(16, 16)
  65#define NEQE_SPECIFIC_EVENT    EHCA_BMASK_IBM(16, 23)
  66
  67#define ERROR_DATA_LENGTH      EHCA_BMASK_IBM(52, 63)
  68#define ERROR_DATA_TYPE        EHCA_BMASK_IBM( 0,  7)
  69
  70static void queue_comp_task(struct ehca_cq *__cq);
  71
  72static struct ehca_comp_pool *pool;
  73
  74static 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
  86static 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=%llx) 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=%llx) has errors.",
 112                         cq->cq_number, resource);
 113                break;
 114        }
 115        default:
 116                ehca_err(&shca->ib_device,
 117                         "Unknown error type: %llx on %s.",
 118                         type, shca->ib_device.name);
 119                break;
 120        }
 121
 122        ehca_err(&shca->ib_device, "Error data is available: %llx.", resource);
 123        ehca_err(&shca->ib_device, "EHCA ----- error data begin "
 124                 "---------------------------------------------------");
 125        ehca_dmp(rblock, length, "resource=%llx", resource);
 126        ehca_err(&shca->ib_device, "EHCA ----- error data end "
 127                 "----------------------------------------------------");
 128
 129        return;
 130}
 131
 132int 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 = ehca_alloc_fw_ctrlblock(GFP_ATOMIC);
 141        if (!rblock) {
 142                ehca_err(&shca->ib_device, "Cannot allocate rblock memory.");
 143                ret = -ENOMEM;
 144                goto error_data1;
 145        }
 146
 147        /* rblock must be 4K aligned and should be 4K large */
 148        ret = hipz_h_error_data(shca->ipz_hca_handle,
 149                                resource,
 150                                rblock,
 151                                &block_count);
 152
 153        if (ret == H_R_STATE)
 154                ehca_err(&shca->ib_device,
 155                         "No error data is available: %llx.", resource);
 156        else if (ret == H_SUCCESS) {
 157                int length;
 158
 159                length = EHCA_BMASK_GET(ERROR_DATA_LENGTH, rblock[0]);
 160
 161                if (length > EHCA_PAGESIZE)
 162                        length = EHCA_PAGESIZE;
 163
 164                print_error_data(shca, data, rblock, length);
 165        } else
 166                ehca_err(&shca->ib_device,
 167                         "Error data could not be fetched: %llx", resource);
 168
 169        ehca_free_fw_ctrlblock(rblock);
 170
 171error_data1:
 172        return ret;
 173
 174}
 175
 176static void dispatch_qp_event(struct ehca_shca *shca, struct ehca_qp *qp,
 177                              enum ib_event_type event_type)
 178{
 179        struct ib_event event;
 180
 181        /* PATH_MIG without the QP ever having been armed is false alarm */
 182        if (event_type == IB_EVENT_PATH_MIG && !qp->mig_armed)
 183                return;
 184
 185        event.device = &shca->ib_device;
 186        event.event = event_type;
 187
 188        if (qp->ext_type == EQPT_SRQ) {
 189                if (!qp->ib_srq.event_handler)
 190                        return;
 191
 192                event.element.srq = &qp->ib_srq;
 193                qp->ib_srq.event_handler(&event, qp->ib_srq.srq_context);
 194        } else {
 195                if (!qp->ib_qp.event_handler)
 196                        return;
 197
 198                event.element.qp = &qp->ib_qp;
 199                qp->ib_qp.event_handler(&event, qp->ib_qp.qp_context);
 200        }
 201}
 202
 203static void qp_event_callback(struct ehca_shca *shca, u64 eqe,
 204                              enum ib_event_type event_type, int fatal)
 205{
 206        struct ehca_qp *qp;
 207        u32 token = EHCA_BMASK_GET(EQE_QP_TOKEN, eqe);
 208
 209        read_lock(&ehca_qp_idr_lock);
 210        qp = idr_find(&ehca_qp_idr, token);
 211        if (qp)
 212                atomic_inc(&qp->nr_events);
 213        read_unlock(&ehca_qp_idr_lock);
 214
 215        if (!qp)
 216                return;
 217
 218        if (fatal)
 219                ehca_error_data(shca, qp, qp->ipz_qp_handle.handle);
 220
 221        dispatch_qp_event(shca, qp, fatal && qp->ext_type == EQPT_SRQ ?
 222                          IB_EVENT_SRQ_ERR : event_type);
 223
 224        /*
 225         * eHCA only processes one WQE at a time for SRQ base QPs,
 226         * so the last WQE has been processed as soon as the QP enters
 227         * error state.
 228         */
 229        if (fatal && qp->ext_type == EQPT_SRQBASE)
 230                dispatch_qp_event(shca, qp, IB_EVENT_QP_LAST_WQE_REACHED);
 231
 232        if (atomic_dec_and_test(&qp->nr_events))
 233                wake_up(&qp->wait_completion);
 234        return;
 235}
 236
 237static void cq_event_callback(struct ehca_shca *shca,
 238                              u64 eqe)
 239{
 240        struct ehca_cq *cq;
 241        u32 token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe);
 242
 243        read_lock(&ehca_cq_idr_lock);
 244        cq = idr_find(&ehca_cq_idr, token);
 245        if (cq)
 246                atomic_inc(&cq->nr_events);
 247        read_unlock(&ehca_cq_idr_lock);
 248
 249        if (!cq)
 250                return;
 251
 252        ehca_error_data(shca, cq, cq->ipz_cq_handle.handle);
 253
 254        if (atomic_dec_and_test(&cq->nr_events))
 255                wake_up(&cq->wait_completion);
 256
 257        return;
 258}
 259
 260static void parse_identifier(struct ehca_shca *shca, u64 eqe)
 261{
 262        u8 identifier = EHCA_BMASK_GET(EQE_EE_IDENTIFIER, eqe);
 263
 264        switch (identifier) {
 265        case 0x02: /* path migrated */
 266                qp_event_callback(shca, eqe, IB_EVENT_PATH_MIG, 0);
 267                break;
 268        case 0x03: /* communication established */
 269                qp_event_callback(shca, eqe, IB_EVENT_COMM_EST, 0);
 270                break;
 271        case 0x04: /* send queue drained */
 272                qp_event_callback(shca, eqe, IB_EVENT_SQ_DRAINED, 0);
 273                break;
 274        case 0x05: /* QP error */
 275        case 0x06: /* QP error */
 276                qp_event_callback(shca, eqe, IB_EVENT_QP_FATAL, 1);
 277                break;
 278        case 0x07: /* CQ error */
 279        case 0x08: /* CQ error */
 280                cq_event_callback(shca, eqe);
 281                break;
 282        case 0x09: /* MRMWPTE error */
 283                ehca_err(&shca->ib_device, "MRMWPTE error.");
 284                break;
 285        case 0x0A: /* port event */
 286                ehca_err(&shca->ib_device, "Port event.");
 287                break;
 288        case 0x0B: /* MR access error */
 289                ehca_err(&shca->ib_device, "MR access error.");
 290                break;
 291        case 0x0C: /* EQ error */
 292                ehca_err(&shca->ib_device, "EQ error.");
 293                break;
 294        case 0x0D: /* P/Q_Key mismatch */
 295                ehca_err(&shca->ib_device, "P/Q_Key mismatch.");
 296                break;
 297        case 0x10: /* sampling complete */
 298                ehca_err(&shca->ib_device, "Sampling complete.");
 299                break;
 300        case 0x11: /* unaffiliated access error */
 301                ehca_err(&shca->ib_device, "Unaffiliated access error.");
 302                break;
 303        case 0x12: /* path migrating */
 304                ehca_err(&shca->ib_device, "Path migrating.");
 305                break;
 306        case 0x13: /* interface trace stopped */
 307                ehca_err(&shca->ib_device, "Interface trace stopped.");
 308                break;
 309        case 0x14: /* first error capture info available */
 310                ehca_info(&shca->ib_device, "First error capture available");
 311                break;
 312        case 0x15: /* SRQ limit reached */
 313                qp_event_callback(shca, eqe, IB_EVENT_SRQ_LIMIT_REACHED, 0);
 314                break;
 315        default:
 316                ehca_err(&shca->ib_device, "Unknown identifier: %x on %s.",
 317                         identifier, shca->ib_device.name);
 318                break;
 319        }
 320
 321        return;
 322}
 323
 324static void dispatch_port_event(struct ehca_shca *shca, int port_num,
 325                                enum ib_event_type type, const char *msg)
 326{
 327        struct ib_event event;
 328
 329        ehca_info(&shca->ib_device, "port %d %s.", port_num, msg);
 330        event.device = &shca->ib_device;
 331        event.event = type;
 332        event.element.port_num = port_num;
 333        ib_dispatch_event(&event);
 334}
 335
 336static void notify_port_conf_change(struct ehca_shca *shca, int port_num)
 337{
 338        struct ehca_sma_attr  new_attr;
 339        struct ehca_sma_attr *old_attr = &shca->sport[port_num - 1].saved_attr;
 340
 341        ehca_query_sma_attr(shca, port_num, &new_attr);
 342
 343        if (new_attr.sm_sl  != old_attr->sm_sl ||
 344            new_attr.sm_lid != old_attr->sm_lid)
 345                dispatch_port_event(shca, port_num, IB_EVENT_SM_CHANGE,
 346                                    "SM changed");
 347
 348        if (new_attr.lid != old_attr->lid ||
 349            new_attr.lmc != old_attr->lmc)
 350                dispatch_port_event(shca, port_num, IB_EVENT_LID_CHANGE,
 351                                    "LID changed");
 352
 353        if (new_attr.pkey_tbl_len != old_attr->pkey_tbl_len ||
 354            memcmp(new_attr.pkeys, old_attr->pkeys,
 355                   sizeof(u16) * new_attr.pkey_tbl_len))
 356                dispatch_port_event(shca, port_num, IB_EVENT_PKEY_CHANGE,
 357                                    "P_Key changed");
 358
 359        *old_attr = new_attr;
 360}
 361
 362/* replay modify_qp for sqps -- return 0 if all is well, 1 if AQP1 destroyed */
 363static int replay_modify_qp(struct ehca_sport *sport)
 364{
 365        int aqp1_destroyed;
 366        unsigned long flags;
 367
 368        spin_lock_irqsave(&sport->mod_sqp_lock, flags);
 369
 370        aqp1_destroyed = !sport->ibqp_sqp[IB_QPT_GSI];
 371
 372        if (sport->ibqp_sqp[IB_QPT_SMI])
 373                ehca_recover_sqp(sport->ibqp_sqp[IB_QPT_SMI]);
 374        if (!aqp1_destroyed)
 375                ehca_recover_sqp(sport->ibqp_sqp[IB_QPT_GSI]);
 376
 377        spin_unlock_irqrestore(&sport->mod_sqp_lock, flags);
 378
 379        return aqp1_destroyed;
 380}
 381
 382static void parse_ec(struct ehca_shca *shca, u64 eqe)
 383{
 384        u8 ec   = EHCA_BMASK_GET(NEQE_EVENT_CODE, eqe);
 385        u8 port = EHCA_BMASK_GET(NEQE_PORT_NUMBER, eqe);
 386        u8 spec_event;
 387        struct ehca_sport *sport = &shca->sport[port - 1];
 388
 389        switch (ec) {
 390        case 0x30: /* port availability change */
 391                if (EHCA_BMASK_GET(NEQE_PORT_AVAILABILITY, eqe)) {
 392                        /* only replay modify_qp calls in autodetect mode;
 393                         * if AQP1 was destroyed, the port is already down
 394                         * again and we can drop the event.
 395                         */
 396                        if (ehca_nr_ports < 0)
 397                                if (replay_modify_qp(sport))
 398                                        break;
 399
 400                        sport->port_state = IB_PORT_ACTIVE;
 401                        dispatch_port_event(shca, port, IB_EVENT_PORT_ACTIVE,
 402                                            "is active");
 403                        ehca_query_sma_attr(shca, port, &sport->saved_attr);
 404                } else {
 405                        sport->port_state = IB_PORT_DOWN;
 406                        dispatch_port_event(shca, port, IB_EVENT_PORT_ERR,
 407                                            "is inactive");
 408                }
 409                break;
 410        case 0x31:
 411                /* port configuration change
 412                 * disruptive change is caused by
 413                 * LID, PKEY or SM change
 414                 */
 415                if (EHCA_BMASK_GET(NEQE_DISRUPTIVE, eqe)) {
 416                        ehca_warn(&shca->ib_device, "disruptive port "
 417                                  "%d configuration change", port);
 418
 419                        sport->port_state = IB_PORT_DOWN;
 420                        dispatch_port_event(shca, port, IB_EVENT_PORT_ERR,
 421                                            "is inactive");
 422
 423                        sport->port_state = IB_PORT_ACTIVE;
 424                        dispatch_port_event(shca, port, IB_EVENT_PORT_ACTIVE,
 425                                            "is active");
 426                        ehca_query_sma_attr(shca, port,
 427                                            &sport->saved_attr);
 428                } else
 429                        notify_port_conf_change(shca, port);
 430                break;
 431        case 0x32: /* adapter malfunction */
 432                ehca_err(&shca->ib_device, "Adapter malfunction.");
 433                break;
 434        case 0x33:  /* trace stopped */
 435                ehca_err(&shca->ib_device, "Traced stopped.");
 436                break;
 437        case 0x34: /* util async event */
 438                spec_event = EHCA_BMASK_GET(NEQE_SPECIFIC_EVENT, eqe);
 439                if (spec_event == 0x80) /* client reregister required */
 440                        dispatch_port_event(shca, port,
 441                                            IB_EVENT_CLIENT_REREGISTER,
 442                                            "client reregister req.");
 443                else
 444                        ehca_warn(&shca->ib_device, "Unknown util async "
 445                                  "event %x on port %x", spec_event, port);
 446                break;
 447        default:
 448                ehca_err(&shca->ib_device, "Unknown event code: %x on %s.",
 449                         ec, shca->ib_device.name);
 450                break;
 451        }
 452
 453        return;
 454}
 455
 456static inline void reset_eq_pending(struct ehca_cq *cq)
 457{
 458        u64 CQx_EP;
 459        struct h_galpa gal = cq->galpas.kernel;
 460
 461        hipz_galpa_store_cq(gal, cqx_ep, 0x0);
 462        CQx_EP = hipz_galpa_load(gal, CQTEMM_OFFSET(cqx_ep));
 463
 464        return;
 465}
 466
 467irqreturn_t ehca_interrupt_neq(int irq, void *dev_id)
 468{
 469        struct ehca_shca *shca = (struct ehca_shca*)dev_id;
 470
 471        tasklet_hi_schedule(&shca->neq.interrupt_task);
 472
 473        return IRQ_HANDLED;
 474}
 475
 476void ehca_tasklet_neq(unsigned long data)
 477{
 478        struct ehca_shca *shca = (struct ehca_shca*)data;
 479        struct ehca_eqe *eqe;
 480        u64 ret;
 481
 482        eqe = ehca_poll_eq(shca, &shca->neq);
 483
 484        while (eqe) {
 485                if (!EHCA_BMASK_GET(NEQE_COMPLETION_EVENT, eqe->entry))
 486                        parse_ec(shca, eqe->entry);
 487
 488                eqe = ehca_poll_eq(shca, &shca->neq);
 489        }
 490
 491        ret = hipz_h_reset_event(shca->ipz_hca_handle,
 492                                 shca->neq.ipz_eq_handle, 0xFFFFFFFFFFFFFFFFL);
 493
 494        if (ret != H_SUCCESS)
 495                ehca_err(&shca->ib_device, "Can't clear notification events.");
 496
 497        return;
 498}
 499
 500irqreturn_t ehca_interrupt_eq(int irq, void *dev_id)
 501{
 502        struct ehca_shca *shca = (struct ehca_shca*)dev_id;
 503
 504        tasklet_hi_schedule(&shca->eq.interrupt_task);
 505
 506        return IRQ_HANDLED;
 507}
 508
 509
 510static inline void process_eqe(struct ehca_shca *shca, struct ehca_eqe *eqe)
 511{
 512        u64 eqe_value;
 513        u32 token;
 514        struct ehca_cq *cq;
 515
 516        eqe_value = eqe->entry;
 517        ehca_dbg(&shca->ib_device, "eqe_value=%llx", eqe_value);
 518        if (EHCA_BMASK_GET(EQE_COMPLETION_EVENT, eqe_value)) {
 519                ehca_dbg(&shca->ib_device, "Got completion event");
 520                token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe_value);
 521                read_lock(&ehca_cq_idr_lock);
 522                cq = idr_find(&ehca_cq_idr, token);
 523                if (cq)
 524                        atomic_inc(&cq->nr_events);
 525                read_unlock(&ehca_cq_idr_lock);
 526                if (cq == NULL) {
 527                        ehca_err(&shca->ib_device,
 528                                 "Invalid eqe for non-existing cq token=%x",
 529                                 token);
 530                        return;
 531                }
 532                reset_eq_pending(cq);
 533                if (ehca_scaling_code)
 534                        queue_comp_task(cq);
 535                else {
 536                        comp_event_callback(cq);
 537                        if (atomic_dec_and_test(&cq->nr_events))
 538                                wake_up(&cq->wait_completion);
 539                }
 540        } else {
 541                ehca_dbg(&shca->ib_device, "Got non completion event");
 542                parse_identifier(shca, eqe_value);
 543        }
 544}
 545
 546void ehca_process_eq(struct ehca_shca *shca, int is_irq)
 547{
 548        struct ehca_eq *eq = &shca->eq;
 549        struct ehca_eqe_cache_entry *eqe_cache = eq->eqe_cache;
 550        u64 eqe_value, ret;
 551        unsigned long flags;
 552        int eqe_cnt, i;
 553        int eq_empty = 0;
 554
 555        spin_lock_irqsave(&eq->irq_spinlock, flags);
 556        if (is_irq) {
 557                const int max_query_cnt = 100;
 558                int query_cnt = 0;
 559                int int_state = 1;
 560                do {
 561                        int_state = hipz_h_query_int_state(
 562                                shca->ipz_hca_handle, eq->ist);
 563                        query_cnt++;
 564                        iosync();
 565                } while (int_state && query_cnt < max_query_cnt);
 566                if (unlikely((query_cnt == max_query_cnt)))
 567                        ehca_dbg(&shca->ib_device, "int_state=%x query_cnt=%x",
 568                                 int_state, query_cnt);
 569        }
 570
 571        /* read out all eqes */
 572        eqe_cnt = 0;
 573        do {
 574                u32 token;
 575                eqe_cache[eqe_cnt].eqe = ehca_poll_eq(shca, eq);
 576                if (!eqe_cache[eqe_cnt].eqe)
 577                        break;
 578                eqe_value = eqe_cache[eqe_cnt].eqe->entry;
 579                if (EHCA_BMASK_GET(EQE_COMPLETION_EVENT, eqe_value)) {
 580                        token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe_value);
 581                        read_lock(&ehca_cq_idr_lock);
 582                        eqe_cache[eqe_cnt].cq = idr_find(&ehca_cq_idr, token);
 583                        if (eqe_cache[eqe_cnt].cq)
 584                                atomic_inc(&eqe_cache[eqe_cnt].cq->nr_events);
 585                        read_unlock(&ehca_cq_idr_lock);
 586                        if (!eqe_cache[eqe_cnt].cq) {
 587                                ehca_err(&shca->ib_device,
 588                                         "Invalid eqe for non-existing cq "
 589                                         "token=%x", token);
 590                                continue;
 591                        }
 592                } else
 593                        eqe_cache[eqe_cnt].cq = NULL;
 594                eqe_cnt++;
 595        } while (eqe_cnt < EHCA_EQE_CACHE_SIZE);
 596        if (!eqe_cnt) {
 597                if (is_irq)
 598                        ehca_dbg(&shca->ib_device,
 599                                 "No eqe found for irq event");
 600                goto unlock_irq_spinlock;
 601        } else if (!is_irq) {
 602                ret = hipz_h_eoi(eq->ist);
 603                if (ret != H_SUCCESS)
 604                        ehca_err(&shca->ib_device,
 605                                 "bad return code EOI -rc = %lld\n", ret);
 606                ehca_dbg(&shca->ib_device, "deadman found %x eqe", eqe_cnt);
 607        }
 608        if (unlikely(eqe_cnt == EHCA_EQE_CACHE_SIZE))
 609                ehca_dbg(&shca->ib_device, "too many eqes for one irq event");
 610        /* enable irq for new packets */
 611        for (i = 0; i < eqe_cnt; i++) {
 612                if (eq->eqe_cache[i].cq)
 613                        reset_eq_pending(eq->eqe_cache[i].cq);
 614        }
 615        /* check eq */
 616        spin_lock(&eq->spinlock);
 617        eq_empty = (!ipz_eqit_eq_peek_valid(&shca->eq.ipz_queue));
 618        spin_unlock(&eq->spinlock);
 619        /* call completion handler for cached eqes */
 620        for (i = 0; i < eqe_cnt; i++)
 621                if (eq->eqe_cache[i].cq) {
 622                        if (ehca_scaling_code)
 623                                queue_comp_task(eq->eqe_cache[i].cq);
 624                        else {
 625                                struct ehca_cq *cq = eq->eqe_cache[i].cq;
 626                                comp_event_callback(cq);
 627                                if (atomic_dec_and_test(&cq->nr_events))
 628                                        wake_up(&cq->wait_completion);
 629                        }
 630                } else {
 631                        ehca_dbg(&shca->ib_device, "Got non completion event");
 632                        parse_identifier(shca, eq->eqe_cache[i].eqe->entry);
 633                }
 634        /* poll eq if not empty */
 635        if (eq_empty)
 636                goto unlock_irq_spinlock;
 637        do {
 638                struct ehca_eqe *eqe;
 639                eqe = ehca_poll_eq(shca, &shca->eq);
 640                if (!eqe)
 641                        break;
 642                process_eqe(shca, eqe);
 643        } while (1);
 644
 645unlock_irq_spinlock:
 646        spin_unlock_irqrestore(&eq->irq_spinlock, flags);
 647}
 648
 649void ehca_tasklet_eq(unsigned long data)
 650{
 651        ehca_process_eq((struct ehca_shca*)data, 1);
 652}
 653
 654static inline int find_next_online_cpu(struct ehca_comp_pool *pool)
 655{
 656        int cpu;
 657        unsigned long flags;
 658
 659        WARN_ON_ONCE(!in_interrupt());
 660        if (ehca_debug_level >= 3)
 661                ehca_dmp(cpu_online_mask, cpumask_size(), "");
 662
 663        spin_lock_irqsave(&pool->last_cpu_lock, flags);
 664        cpu = cpumask_next(pool->last_cpu, cpu_online_mask);
 665        if (cpu >= nr_cpu_ids)
 666                cpu = cpumask_first(cpu_online_mask);
 667        pool->last_cpu = cpu;
 668        spin_unlock_irqrestore(&pool->last_cpu_lock, flags);
 669
 670        return cpu;
 671}
 672
 673static void __queue_comp_task(struct ehca_cq *__cq,
 674                              struct ehca_cpu_comp_task *cct)
 675{
 676        unsigned long flags;
 677
 678        spin_lock_irqsave(&cct->task_lock, flags);
 679        spin_lock(&__cq->task_lock);
 680
 681        if (__cq->nr_callbacks == 0) {
 682                __cq->nr_callbacks++;
 683                list_add_tail(&__cq->entry, &cct->cq_list);
 684                cct->cq_jobs++;
 685                wake_up(&cct->wait_queue);
 686        } else
 687                __cq->nr_callbacks++;
 688
 689        spin_unlock(&__cq->task_lock);
 690        spin_unlock_irqrestore(&cct->task_lock, flags);
 691}
 692
 693static void queue_comp_task(struct ehca_cq *__cq)
 694{
 695        int cpu_id;
 696        struct ehca_cpu_comp_task *cct;
 697        int cq_jobs;
 698        unsigned long flags;
 699
 700        cpu_id = find_next_online_cpu(pool);
 701        BUG_ON(!cpu_online(cpu_id));
 702
 703        cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu_id);
 704        BUG_ON(!cct);
 705
 706        spin_lock_irqsave(&cct->task_lock, flags);
 707        cq_jobs = cct->cq_jobs;
 708        spin_unlock_irqrestore(&cct->task_lock, flags);
 709        if (cq_jobs > 0) {
 710                cpu_id = find_next_online_cpu(pool);
 711                cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu_id);
 712                BUG_ON(!cct);
 713        }
 714
 715        __queue_comp_task(__cq, cct);
 716}
 717
 718static void run_comp_task(struct ehca_cpu_comp_task *cct)
 719{
 720        struct ehca_cq *cq;
 721        unsigned long flags;
 722
 723        spin_lock_irqsave(&cct->task_lock, flags);
 724
 725        while (!list_empty(&cct->cq_list)) {
 726                cq = list_entry(cct->cq_list.next, struct ehca_cq, entry);
 727                spin_unlock_irqrestore(&cct->task_lock, flags);
 728
 729                comp_event_callback(cq);
 730                if (atomic_dec_and_test(&cq->nr_events))
 731                        wake_up(&cq->wait_completion);
 732
 733                spin_lock_irqsave(&cct->task_lock, flags);
 734                spin_lock(&cq->task_lock);
 735                cq->nr_callbacks--;
 736                if (!cq->nr_callbacks) {
 737                        list_del_init(cct->cq_list.next);
 738                        cct->cq_jobs--;
 739                }
 740                spin_unlock(&cq->task_lock);
 741        }
 742
 743        spin_unlock_irqrestore(&cct->task_lock, flags);
 744}
 745
 746static int comp_task(void *__cct)
 747{
 748        struct ehca_cpu_comp_task *cct = __cct;
 749        int cql_empty;
 750        DECLARE_WAITQUEUE(wait, current);
 751
 752        set_current_state(TASK_INTERRUPTIBLE);
 753        while (!kthread_should_stop()) {
 754                add_wait_queue(&cct->wait_queue, &wait);
 755
 756                spin_lock_irq(&cct->task_lock);
 757                cql_empty = list_empty(&cct->cq_list);
 758                spin_unlock_irq(&cct->task_lock);
 759                if (cql_empty)
 760                        schedule();
 761                else
 762                        __set_current_state(TASK_RUNNING);
 763
 764                remove_wait_queue(&cct->wait_queue, &wait);
 765
 766                spin_lock_irq(&cct->task_lock);
 767                cql_empty = list_empty(&cct->cq_list);
 768                spin_unlock_irq(&cct->task_lock);
 769                if (!cql_empty)
 770                        run_comp_task(__cct);
 771
 772                set_current_state(TASK_INTERRUPTIBLE);
 773        }
 774        __set_current_state(TASK_RUNNING);
 775
 776        return 0;
 777}
 778
 779static struct task_struct *create_comp_task(struct ehca_comp_pool *pool,
 780                                            int cpu)
 781{
 782        struct ehca_cpu_comp_task *cct;
 783
 784        cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 785        spin_lock_init(&cct->task_lock);
 786        INIT_LIST_HEAD(&cct->cq_list);
 787        init_waitqueue_head(&cct->wait_queue);
 788        cct->task = kthread_create(comp_task, cct, "ehca_comp/%d", cpu);
 789
 790        return cct->task;
 791}
 792
 793static void destroy_comp_task(struct ehca_comp_pool *pool,
 794                              int cpu)
 795{
 796        struct ehca_cpu_comp_task *cct;
 797        struct task_struct *task;
 798        unsigned long flags_cct;
 799
 800        cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 801
 802        spin_lock_irqsave(&cct->task_lock, flags_cct);
 803
 804        task = cct->task;
 805        cct->task = NULL;
 806        cct->cq_jobs = 0;
 807
 808        spin_unlock_irqrestore(&cct->task_lock, flags_cct);
 809
 810        if (task)
 811                kthread_stop(task);
 812}
 813
 814static void __cpuinit take_over_work(struct ehca_comp_pool *pool, int cpu)
 815{
 816        struct ehca_cpu_comp_task *cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 817        LIST_HEAD(list);
 818        struct ehca_cq *cq;
 819        unsigned long flags_cct;
 820
 821        spin_lock_irqsave(&cct->task_lock, flags_cct);
 822
 823        list_splice_init(&cct->cq_list, &list);
 824
 825        while (!list_empty(&list)) {
 826                cq = list_entry(cct->cq_list.next, struct ehca_cq, entry);
 827
 828                list_del(&cq->entry);
 829                __queue_comp_task(cq, per_cpu_ptr(pool->cpu_comp_tasks,
 830                                                  smp_processor_id()));
 831        }
 832
 833        spin_unlock_irqrestore(&cct->task_lock, flags_cct);
 834
 835}
 836
 837static int __cpuinit comp_pool_callback(struct notifier_block *nfb,
 838                                        unsigned long action,
 839                                        void *hcpu)
 840{
 841        unsigned int cpu = (unsigned long)hcpu;
 842        struct ehca_cpu_comp_task *cct;
 843
 844        switch (action) {
 845        case CPU_UP_PREPARE:
 846        case CPU_UP_PREPARE_FROZEN:
 847                ehca_gen_dbg("CPU: %x (CPU_PREPARE)", cpu);
 848                if (!create_comp_task(pool, cpu)) {
 849                        ehca_gen_err("Can't create comp_task for cpu: %x", cpu);
 850                        return NOTIFY_BAD;
 851                }
 852                break;
 853        case CPU_UP_CANCELED:
 854        case CPU_UP_CANCELED_FROZEN:
 855                ehca_gen_dbg("CPU: %x (CPU_CANCELED)", cpu);
 856                cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 857                kthread_bind(cct->task, cpumask_any(cpu_online_mask));
 858                destroy_comp_task(pool, cpu);
 859                break;
 860        case CPU_ONLINE:
 861        case CPU_ONLINE_FROZEN:
 862                ehca_gen_dbg("CPU: %x (CPU_ONLINE)", cpu);
 863                cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
 864                kthread_bind(cct->task, cpu);
 865                wake_up_process(cct->task);
 866                break;
 867        case CPU_DOWN_PREPARE:
 868        case CPU_DOWN_PREPARE_FROZEN:
 869                ehca_gen_dbg("CPU: %x (CPU_DOWN_PREPARE)", cpu);
 870                break;
 871        case CPU_DOWN_FAILED:
 872        case CPU_DOWN_FAILED_FROZEN:
 873                ehca_gen_dbg("CPU: %x (CPU_DOWN_FAILED)", cpu);
 874                break;
 875        case CPU_DEAD:
 876        case CPU_DEAD_FROZEN:
 877                ehca_gen_dbg("CPU: %x (CPU_DEAD)", cpu);
 878                destroy_comp_task(pool, cpu);
 879                take_over_work(pool, cpu);
 880                break;
 881        }
 882
 883        return NOTIFY_OK;
 884}
 885
 886static struct notifier_block comp_pool_callback_nb __cpuinitdata = {
 887        .notifier_call  = comp_pool_callback,
 888        .priority       = 0,
 889};
 890
 891int ehca_create_comp_pool(void)
 892{
 893        int cpu;
 894        struct task_struct *task;
 895
 896        if (!ehca_scaling_code)
 897                return 0;
 898
 899        pool = kzalloc(sizeof(struct ehca_comp_pool), GFP_KERNEL);
 900        if (pool == NULL)
 901                return -ENOMEM;
 902
 903        spin_lock_init(&pool->last_cpu_lock);
 904        pool->last_cpu = cpumask_any(cpu_online_mask);
 905
 906        pool->cpu_comp_tasks = alloc_percpu(struct ehca_cpu_comp_task);
 907        if (pool->cpu_comp_tasks == NULL) {
 908                kfree(pool);
 909                return -EINVAL;
 910        }
 911
 912        for_each_online_cpu(cpu) {
 913                task = create_comp_task(pool, cpu);
 914                if (task) {
 915                        kthread_bind(task, cpu);
 916                        wake_up_process(task);
 917                }
 918        }
 919
 920        register_hotcpu_notifier(&comp_pool_callback_nb);
 921
 922        printk(KERN_INFO "eHCA scaling code enabled\n");
 923
 924        return 0;
 925}
 926
 927void ehca_destroy_comp_pool(void)
 928{
 929        int i;
 930
 931        if (!ehca_scaling_code)
 932                return;
 933
 934        unregister_hotcpu_notifier(&comp_pool_callback_nb);
 935
 936        for_each_online_cpu(i)
 937                destroy_comp_task(pool, i);
 938
 939        free_percpu(pool->cpu_comp_tasks);
 940        kfree(pool);
 941}
 942