Merge branch 'for-2.6.25' of master.kernel.org:/pub/scm/linux/kernel/git/galak/powerp...
[linux-2.6] / 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  *           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
70 static void queue_comp_task(struct ehca_cq *__cq);
71
72 static struct ehca_comp_pool *pool;
73
74 static inline void comp_event_callback(struct ehca_cq *cq)
75 {
76         if (!cq->ib_cq.comp_handler)
77                 return;
78
79         spin_lock(&cq->cb_lock);
80         cq->ib_cq.comp_handler(&cq->ib_cq, cq->ib_cq.cq_context);
81         spin_unlock(&cq->cb_lock);
82
83         return;
84 }
85
86 static void print_error_data(struct ehca_shca *shca, void *data,
87                              u64 *rblock, int length)
88 {
89         u64 type = EHCA_BMASK_GET(ERROR_DATA_TYPE, rblock[2]);
90         u64 resource = rblock[1];
91
92         switch (type) {
93         case 0x1: /* Queue Pair */
94         {
95                 struct ehca_qp *qp = (struct ehca_qp *)data;
96
97                 /* only print error data if AER is set */
98                 if (rblock[6] == 0)
99                         return;
100
101                 ehca_err(&shca->ib_device,
102                          "QP 0x%x (resource=%lx) has errors.",
103                          qp->ib_qp.qp_num, resource);
104                 break;
105         }
106         case 0x4: /* Completion Queue */
107         {
108                 struct ehca_cq *cq = (struct ehca_cq *)data;
109
110                 ehca_err(&shca->ib_device,
111                          "CQ 0x%x (resource=%lx) has errors.",
112                          cq->cq_number, resource);
113                 break;
114         }
115         default:
116                 ehca_err(&shca->ib_device,
117                          "Unknown error type: %lx on %s.",
118                          type, shca->ib_device.name);
119                 break;
120         }
121
122         ehca_err(&shca->ib_device, "Error data is available: %lx.", resource);
123         ehca_err(&shca->ib_device, "EHCA ----- error data begin "
124                  "---------------------------------------------------");
125         ehca_dmp(rblock, length, "resource=%lx", resource);
126         ehca_err(&shca->ib_device, "EHCA ----- error data end "
127                  "----------------------------------------------------");
128
129         return;
130 }
131
132 int ehca_error_data(struct ehca_shca *shca, void *data,
133                     u64 resource)
134 {
135
136         unsigned long ret;
137         u64 *rblock;
138         unsigned long block_count;
139
140         rblock = 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: %lx.", 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: %lx", resource);
168
169         ehca_free_fw_ctrlblock(rblock);
170
171 error_data1:
172         return ret;
173
174 }
175
176 static 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         event.device = &shca->ib_device;
182         event.event = event_type;
183
184         if (qp->ext_type == EQPT_SRQ) {
185                 if (!qp->ib_srq.event_handler)
186                         return;
187
188                 event.element.srq = &qp->ib_srq;
189                 qp->ib_srq.event_handler(&event, qp->ib_srq.srq_context);
190         } else {
191                 if (!qp->ib_qp.event_handler)
192                         return;
193
194                 event.element.qp = &qp->ib_qp;
195                 qp->ib_qp.event_handler(&event, qp->ib_qp.qp_context);
196         }
197 }
198
199 static void qp_event_callback(struct ehca_shca *shca, u64 eqe,
200                               enum ib_event_type event_type, int fatal)
201 {
202         struct ehca_qp *qp;
203         u32 token = EHCA_BMASK_GET(EQE_QP_TOKEN, eqe);
204
205         read_lock(&ehca_qp_idr_lock);
206         qp = idr_find(&ehca_qp_idr, token);
207         read_unlock(&ehca_qp_idr_lock);
208
209         if (!qp)
210                 return;
211
212         if (fatal)
213                 ehca_error_data(shca, qp, qp->ipz_qp_handle.handle);
214
215         dispatch_qp_event(shca, qp, fatal && qp->ext_type == EQPT_SRQ ?
216                           IB_EVENT_SRQ_ERR : event_type);
217
218         /*
219          * eHCA only processes one WQE at a time for SRQ base QPs,
220          * so the last WQE has been processed as soon as the QP enters
221          * error state.
222          */
223         if (fatal && qp->ext_type == EQPT_SRQBASE)
224                 dispatch_qp_event(shca, qp, IB_EVENT_QP_LAST_WQE_REACHED);
225
226         return;
227 }
228
229 static void cq_event_callback(struct ehca_shca *shca,
230                               u64 eqe)
231 {
232         struct ehca_cq *cq;
233         u32 token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe);
234
235         read_lock(&ehca_cq_idr_lock);
236         cq = idr_find(&ehca_cq_idr, token);
237         if (cq)
238                 atomic_inc(&cq->nr_events);
239         read_unlock(&ehca_cq_idr_lock);
240
241         if (!cq)
242                 return;
243
244         ehca_error_data(shca, cq, cq->ipz_cq_handle.handle);
245
246         if (atomic_dec_and_test(&cq->nr_events))
247                 wake_up(&cq->wait_completion);
248
249         return;
250 }
251
252 static void parse_identifier(struct ehca_shca *shca, u64 eqe)
253 {
254         u8 identifier = EHCA_BMASK_GET(EQE_EE_IDENTIFIER, eqe);
255
256         switch (identifier) {
257         case 0x02: /* path migrated */
258                 qp_event_callback(shca, eqe, IB_EVENT_PATH_MIG, 0);
259                 break;
260         case 0x03: /* communication established */
261                 qp_event_callback(shca, eqe, IB_EVENT_COMM_EST, 0);
262                 break;
263         case 0x04: /* send queue drained */
264                 qp_event_callback(shca, eqe, IB_EVENT_SQ_DRAINED, 0);
265                 break;
266         case 0x05: /* QP error */
267         case 0x06: /* QP error */
268                 qp_event_callback(shca, eqe, IB_EVENT_QP_FATAL, 1);
269                 break;
270         case 0x07: /* CQ error */
271         case 0x08: /* CQ error */
272                 cq_event_callback(shca, eqe);
273                 break;
274         case 0x09: /* MRMWPTE error */
275                 ehca_err(&shca->ib_device, "MRMWPTE error.");
276                 break;
277         case 0x0A: /* port event */
278                 ehca_err(&shca->ib_device, "Port event.");
279                 break;
280         case 0x0B: /* MR access error */
281                 ehca_err(&shca->ib_device, "MR access error.");
282                 break;
283         case 0x0C: /* EQ error */
284                 ehca_err(&shca->ib_device, "EQ error.");
285                 break;
286         case 0x0D: /* P/Q_Key mismatch */
287                 ehca_err(&shca->ib_device, "P/Q_Key mismatch.");
288                 break;
289         case 0x10: /* sampling complete */
290                 ehca_err(&shca->ib_device, "Sampling complete.");
291                 break;
292         case 0x11: /* unaffiliated access error */
293                 ehca_err(&shca->ib_device, "Unaffiliated access error.");
294                 break;
295         case 0x12: /* path migrating */
296                 ehca_err(&shca->ib_device, "Path migrating.");
297                 break;
298         case 0x13: /* interface trace stopped */
299                 ehca_err(&shca->ib_device, "Interface trace stopped.");
300                 break;
301         case 0x14: /* first error capture info available */
302                 ehca_info(&shca->ib_device, "First error capture available");
303                 break;
304         case 0x15: /* SRQ limit reached */
305                 qp_event_callback(shca, eqe, IB_EVENT_SRQ_LIMIT_REACHED, 0);
306                 break;
307         default:
308                 ehca_err(&shca->ib_device, "Unknown identifier: %x on %s.",
309                          identifier, shca->ib_device.name);
310                 break;
311         }
312
313         return;
314 }
315
316 static void dispatch_port_event(struct ehca_shca *shca, int port_num,
317                                 enum ib_event_type type, const char *msg)
318 {
319         struct ib_event event;
320
321         ehca_info(&shca->ib_device, "port %d %s.", port_num, msg);
322         event.device = &shca->ib_device;
323         event.event = type;
324         event.element.port_num = port_num;
325         ib_dispatch_event(&event);
326 }
327
328 static void notify_port_conf_change(struct ehca_shca *shca, int port_num)
329 {
330         struct ehca_sma_attr  new_attr;
331         struct ehca_sma_attr *old_attr = &shca->sport[port_num - 1].saved_attr;
332
333         ehca_query_sma_attr(shca, port_num, &new_attr);
334
335         if (new_attr.sm_sl  != old_attr->sm_sl ||
336             new_attr.sm_lid != old_attr->sm_lid)
337                 dispatch_port_event(shca, port_num, IB_EVENT_SM_CHANGE,
338                                     "SM changed");
339
340         if (new_attr.lid != old_attr->lid ||
341             new_attr.lmc != old_attr->lmc)
342                 dispatch_port_event(shca, port_num, IB_EVENT_LID_CHANGE,
343                                     "LID changed");
344
345         if (new_attr.pkey_tbl_len != old_attr->pkey_tbl_len ||
346             memcmp(new_attr.pkeys, old_attr->pkeys,
347                    sizeof(u16) * new_attr.pkey_tbl_len))
348                 dispatch_port_event(shca, port_num, IB_EVENT_PKEY_CHANGE,
349                                     "P_Key changed");
350
351         *old_attr = new_attr;
352 }
353
354 static void parse_ec(struct ehca_shca *shca, u64 eqe)
355 {
356         u8 ec   = EHCA_BMASK_GET(NEQE_EVENT_CODE, eqe);
357         u8 port = EHCA_BMASK_GET(NEQE_PORT_NUMBER, eqe);
358         u8 spec_event;
359         struct ehca_sport *sport = &shca->sport[port - 1];
360         unsigned long flags;
361
362         switch (ec) {
363         case 0x30: /* port availability change */
364                 if (EHCA_BMASK_GET(NEQE_PORT_AVAILABILITY, eqe)) {
365                         int suppress_event;
366                         /* replay modify_qp for sqps */
367                         spin_lock_irqsave(&sport->mod_sqp_lock, flags);
368                         suppress_event = !sport->ibqp_sqp[IB_QPT_GSI];
369                         if (sport->ibqp_sqp[IB_QPT_SMI])
370                                 ehca_recover_sqp(sport->ibqp_sqp[IB_QPT_SMI]);
371                         if (!suppress_event)
372                                 ehca_recover_sqp(sport->ibqp_sqp[IB_QPT_GSI]);
373                         spin_unlock_irqrestore(&sport->mod_sqp_lock, flags);
374
375                         /* AQP1 was destroyed, ignore this event */
376                         if (suppress_event)
377                                 break;
378
379                         sport->port_state = IB_PORT_ACTIVE;
380                         dispatch_port_event(shca, port, IB_EVENT_PORT_ACTIVE,
381                                             "is active");
382                         ehca_query_sma_attr(shca, port,
383                                             &sport->saved_attr);
384                 } else {
385                         sport->port_state = IB_PORT_DOWN;
386                         dispatch_port_event(shca, port, IB_EVENT_PORT_ERR,
387                                             "is inactive");
388                 }
389                 break;
390         case 0x31:
391                 /* port configuration change
392                  * disruptive change is caused by
393                  * LID, PKEY or SM change
394                  */
395                 if (EHCA_BMASK_GET(NEQE_DISRUPTIVE, eqe)) {
396                         ehca_warn(&shca->ib_device, "disruptive port "
397                                   "%d configuration change", port);
398
399                         sport->port_state = IB_PORT_DOWN;
400                         dispatch_port_event(shca, port, IB_EVENT_PORT_ERR,
401                                             "is inactive");
402
403                         sport->port_state = IB_PORT_ACTIVE;
404                         dispatch_port_event(shca, port, IB_EVENT_PORT_ACTIVE,
405                                             "is active");
406                         ehca_query_sma_attr(shca, port,
407                                             &sport->saved_attr);
408                 } else
409                         notify_port_conf_change(shca, port);
410                 break;
411         case 0x32: /* adapter malfunction */
412                 ehca_err(&shca->ib_device, "Adapter malfunction.");
413                 break;
414         case 0x33:  /* trace stopped */
415                 ehca_err(&shca->ib_device, "Traced stopped.");
416                 break;
417         case 0x34: /* util async event */
418                 spec_event = EHCA_BMASK_GET(NEQE_SPECIFIC_EVENT, eqe);
419                 if (spec_event == 0x80) /* client reregister required */
420                         dispatch_port_event(shca, port,
421                                             IB_EVENT_CLIENT_REREGISTER,
422                                             "client reregister req.");
423                 else
424                         ehca_warn(&shca->ib_device, "Unknown util async "
425                                   "event %x on port %x", spec_event, port);
426                 break;
427         default:
428                 ehca_err(&shca->ib_device, "Unknown event code: %x on %s.",
429                          ec, shca->ib_device.name);
430                 break;
431         }
432
433         return;
434 }
435
436 static inline void reset_eq_pending(struct ehca_cq *cq)
437 {
438         u64 CQx_EP;
439         struct h_galpa gal = cq->galpas.kernel;
440
441         hipz_galpa_store_cq(gal, cqx_ep, 0x0);
442         CQx_EP = hipz_galpa_load(gal, CQTEMM_OFFSET(cqx_ep));
443
444         return;
445 }
446
447 irqreturn_t ehca_interrupt_neq(int irq, void *dev_id)
448 {
449         struct ehca_shca *shca = (struct ehca_shca*)dev_id;
450
451         tasklet_hi_schedule(&shca->neq.interrupt_task);
452
453         return IRQ_HANDLED;
454 }
455
456 void ehca_tasklet_neq(unsigned long data)
457 {
458         struct ehca_shca *shca = (struct ehca_shca*)data;
459         struct ehca_eqe *eqe;
460         u64 ret;
461
462         eqe = (struct ehca_eqe *)ehca_poll_eq(shca, &shca->neq);
463
464         while (eqe) {
465                 if (!EHCA_BMASK_GET(NEQE_COMPLETION_EVENT, eqe->entry))
466                         parse_ec(shca, eqe->entry);
467
468                 eqe = (struct ehca_eqe *)ehca_poll_eq(shca, &shca->neq);
469         }
470
471         ret = hipz_h_reset_event(shca->ipz_hca_handle,
472                                  shca->neq.ipz_eq_handle, 0xFFFFFFFFFFFFFFFFL);
473
474         if (ret != H_SUCCESS)
475                 ehca_err(&shca->ib_device, "Can't clear notification events.");
476
477         return;
478 }
479
480 irqreturn_t ehca_interrupt_eq(int irq, void *dev_id)
481 {
482         struct ehca_shca *shca = (struct ehca_shca*)dev_id;
483
484         tasklet_hi_schedule(&shca->eq.interrupt_task);
485
486         return IRQ_HANDLED;
487 }
488
489
490 static inline void process_eqe(struct ehca_shca *shca, struct ehca_eqe *eqe)
491 {
492         u64 eqe_value;
493         u32 token;
494         struct ehca_cq *cq;
495
496         eqe_value = eqe->entry;
497         ehca_dbg(&shca->ib_device, "eqe_value=%lx", eqe_value);
498         if (EHCA_BMASK_GET(EQE_COMPLETION_EVENT, eqe_value)) {
499                 ehca_dbg(&shca->ib_device, "Got completion event");
500                 token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe_value);
501                 read_lock(&ehca_cq_idr_lock);
502                 cq = idr_find(&ehca_cq_idr, token);
503                 if (cq)
504                         atomic_inc(&cq->nr_events);
505                 read_unlock(&ehca_cq_idr_lock);
506                 if (cq == NULL) {
507                         ehca_err(&shca->ib_device,
508                                  "Invalid eqe for non-existing cq token=%x",
509                                  token);
510                         return;
511                 }
512                 reset_eq_pending(cq);
513                 if (ehca_scaling_code)
514                         queue_comp_task(cq);
515                 else {
516                         comp_event_callback(cq);
517                         if (atomic_dec_and_test(&cq->nr_events))
518                                 wake_up(&cq->wait_completion);
519                 }
520         } else {
521                 ehca_dbg(&shca->ib_device, "Got non completion event");
522                 parse_identifier(shca, eqe_value);
523         }
524 }
525
526 void ehca_process_eq(struct ehca_shca *shca, int is_irq)
527 {
528         struct ehca_eq *eq = &shca->eq;
529         struct ehca_eqe_cache_entry *eqe_cache = eq->eqe_cache;
530         u64 eqe_value;
531         unsigned long flags;
532         int eqe_cnt, i;
533         int eq_empty = 0;
534
535         spin_lock_irqsave(&eq->irq_spinlock, flags);
536         if (is_irq) {
537                 const int max_query_cnt = 100;
538                 int query_cnt = 0;
539                 int int_state = 1;
540                 do {
541                         int_state = hipz_h_query_int_state(
542                                 shca->ipz_hca_handle, eq->ist);
543                         query_cnt++;
544                         iosync();
545                 } while (int_state && query_cnt < max_query_cnt);
546                 if (unlikely((query_cnt == max_query_cnt)))
547                         ehca_dbg(&shca->ib_device, "int_state=%x query_cnt=%x",
548                                  int_state, query_cnt);
549         }
550
551         /* read out all eqes */
552         eqe_cnt = 0;
553         do {
554                 u32 token;
555                 eqe_cache[eqe_cnt].eqe =
556                         (struct ehca_eqe *)ehca_poll_eq(shca, eq);
557                 if (!eqe_cache[eqe_cnt].eqe)
558                         break;
559                 eqe_value = eqe_cache[eqe_cnt].eqe->entry;
560                 if (EHCA_BMASK_GET(EQE_COMPLETION_EVENT, eqe_value)) {
561                         token = EHCA_BMASK_GET(EQE_CQ_TOKEN, eqe_value);
562                         read_lock(&ehca_cq_idr_lock);
563                         eqe_cache[eqe_cnt].cq = idr_find(&ehca_cq_idr, token);
564                         if (eqe_cache[eqe_cnt].cq)
565                                 atomic_inc(&eqe_cache[eqe_cnt].cq->nr_events);
566                         read_unlock(&ehca_cq_idr_lock);
567                         if (!eqe_cache[eqe_cnt].cq) {
568                                 ehca_err(&shca->ib_device,
569                                          "Invalid eqe for non-existing cq "
570                                          "token=%x", token);
571                                 continue;
572                         }
573                 } else
574                         eqe_cache[eqe_cnt].cq = NULL;
575                 eqe_cnt++;
576         } while (eqe_cnt < EHCA_EQE_CACHE_SIZE);
577         if (!eqe_cnt) {
578                 if (is_irq)
579                         ehca_dbg(&shca->ib_device,
580                                  "No eqe found for irq event");
581                 goto unlock_irq_spinlock;
582         } else if (!is_irq)
583                 ehca_dbg(&shca->ib_device, "deadman found %x eqe", eqe_cnt);
584         if (unlikely(eqe_cnt == EHCA_EQE_CACHE_SIZE))
585                 ehca_dbg(&shca->ib_device, "too many eqes for one irq event");
586         /* enable irq for new packets */
587         for (i = 0; i < eqe_cnt; i++) {
588                 if (eq->eqe_cache[i].cq)
589                         reset_eq_pending(eq->eqe_cache[i].cq);
590         }
591         /* check eq */
592         spin_lock(&eq->spinlock);
593         eq_empty = (!ipz_eqit_eq_peek_valid(&shca->eq.ipz_queue));
594         spin_unlock(&eq->spinlock);
595         /* call completion handler for cached eqes */
596         for (i = 0; i < eqe_cnt; i++)
597                 if (eq->eqe_cache[i].cq) {
598                         if (ehca_scaling_code)
599                                 queue_comp_task(eq->eqe_cache[i].cq);
600                         else {
601                                 struct ehca_cq *cq = eq->eqe_cache[i].cq;
602                                 comp_event_callback(cq);
603                                 if (atomic_dec_and_test(&cq->nr_events))
604                                         wake_up(&cq->wait_completion);
605                         }
606                 } else {
607                         ehca_dbg(&shca->ib_device, "Got non completion event");
608                         parse_identifier(shca, eq->eqe_cache[i].eqe->entry);
609                 }
610         /* poll eq if not empty */
611         if (eq_empty)
612                 goto unlock_irq_spinlock;
613         do {
614                 struct ehca_eqe *eqe;
615                 eqe = (struct ehca_eqe *)ehca_poll_eq(shca, &shca->eq);
616                 if (!eqe)
617                         break;
618                 process_eqe(shca, eqe);
619         } while (1);
620
621 unlock_irq_spinlock:
622         spin_unlock_irqrestore(&eq->irq_spinlock, flags);
623 }
624
625 void ehca_tasklet_eq(unsigned long data)
626 {
627         ehca_process_eq((struct ehca_shca*)data, 1);
628 }
629
630 static inline int find_next_online_cpu(struct ehca_comp_pool *pool)
631 {
632         int cpu;
633         unsigned long flags;
634
635         WARN_ON_ONCE(!in_interrupt());
636         if (ehca_debug_level)
637                 ehca_dmp(&cpu_online_map, sizeof(cpumask_t), "");
638
639         spin_lock_irqsave(&pool->last_cpu_lock, flags);
640         cpu = next_cpu(pool->last_cpu, cpu_online_map);
641         if (cpu == NR_CPUS)
642                 cpu = first_cpu(cpu_online_map);
643         pool->last_cpu = cpu;
644         spin_unlock_irqrestore(&pool->last_cpu_lock, flags);
645
646         return cpu;
647 }
648
649 static void __queue_comp_task(struct ehca_cq *__cq,
650                               struct ehca_cpu_comp_task *cct)
651 {
652         unsigned long flags;
653
654         spin_lock_irqsave(&cct->task_lock, flags);
655         spin_lock(&__cq->task_lock);
656
657         if (__cq->nr_callbacks == 0) {
658                 __cq->nr_callbacks++;
659                 list_add_tail(&__cq->entry, &cct->cq_list);
660                 cct->cq_jobs++;
661                 wake_up(&cct->wait_queue);
662         } else
663                 __cq->nr_callbacks++;
664
665         spin_unlock(&__cq->task_lock);
666         spin_unlock_irqrestore(&cct->task_lock, flags);
667 }
668
669 static void queue_comp_task(struct ehca_cq *__cq)
670 {
671         int cpu_id;
672         struct ehca_cpu_comp_task *cct;
673         int cq_jobs;
674         unsigned long flags;
675
676         cpu_id = find_next_online_cpu(pool);
677         BUG_ON(!cpu_online(cpu_id));
678
679         cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu_id);
680         BUG_ON(!cct);
681
682         spin_lock_irqsave(&cct->task_lock, flags);
683         cq_jobs = cct->cq_jobs;
684         spin_unlock_irqrestore(&cct->task_lock, flags);
685         if (cq_jobs > 0) {
686                 cpu_id = find_next_online_cpu(pool);
687                 cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu_id);
688                 BUG_ON(!cct);
689         }
690
691         __queue_comp_task(__cq, cct);
692 }
693
694 static void run_comp_task(struct ehca_cpu_comp_task *cct)
695 {
696         struct ehca_cq *cq;
697         unsigned long flags;
698
699         spin_lock_irqsave(&cct->task_lock, flags);
700
701         while (!list_empty(&cct->cq_list)) {
702                 cq = list_entry(cct->cq_list.next, struct ehca_cq, entry);
703                 spin_unlock_irqrestore(&cct->task_lock, flags);
704
705                 comp_event_callback(cq);
706                 if (atomic_dec_and_test(&cq->nr_events))
707                         wake_up(&cq->wait_completion);
708
709                 spin_lock_irqsave(&cct->task_lock, flags);
710                 spin_lock(&cq->task_lock);
711                 cq->nr_callbacks--;
712                 if (!cq->nr_callbacks) {
713                         list_del_init(cct->cq_list.next);
714                         cct->cq_jobs--;
715                 }
716                 spin_unlock(&cq->task_lock);
717         }
718
719         spin_unlock_irqrestore(&cct->task_lock, flags);
720 }
721
722 static int comp_task(void *__cct)
723 {
724         struct ehca_cpu_comp_task *cct = __cct;
725         int cql_empty;
726         DECLARE_WAITQUEUE(wait, current);
727
728         set_current_state(TASK_INTERRUPTIBLE);
729         while (!kthread_should_stop()) {
730                 add_wait_queue(&cct->wait_queue, &wait);
731
732                 spin_lock_irq(&cct->task_lock);
733                 cql_empty = list_empty(&cct->cq_list);
734                 spin_unlock_irq(&cct->task_lock);
735                 if (cql_empty)
736                         schedule();
737                 else
738                         __set_current_state(TASK_RUNNING);
739
740                 remove_wait_queue(&cct->wait_queue, &wait);
741
742                 spin_lock_irq(&cct->task_lock);
743                 cql_empty = list_empty(&cct->cq_list);
744                 spin_unlock_irq(&cct->task_lock);
745                 if (!cql_empty)
746                         run_comp_task(__cct);
747
748                 set_current_state(TASK_INTERRUPTIBLE);
749         }
750         __set_current_state(TASK_RUNNING);
751
752         return 0;
753 }
754
755 static struct task_struct *create_comp_task(struct ehca_comp_pool *pool,
756                                             int cpu)
757 {
758         struct ehca_cpu_comp_task *cct;
759
760         cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
761         spin_lock_init(&cct->task_lock);
762         INIT_LIST_HEAD(&cct->cq_list);
763         init_waitqueue_head(&cct->wait_queue);
764         cct->task = kthread_create(comp_task, cct, "ehca_comp/%d", cpu);
765
766         return cct->task;
767 }
768
769 static void destroy_comp_task(struct ehca_comp_pool *pool,
770                               int cpu)
771 {
772         struct ehca_cpu_comp_task *cct;
773         struct task_struct *task;
774         unsigned long flags_cct;
775
776         cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
777
778         spin_lock_irqsave(&cct->task_lock, flags_cct);
779
780         task = cct->task;
781         cct->task = NULL;
782         cct->cq_jobs = 0;
783
784         spin_unlock_irqrestore(&cct->task_lock, flags_cct);
785
786         if (task)
787                 kthread_stop(task);
788 }
789
790 static void __cpuinit take_over_work(struct ehca_comp_pool *pool, int cpu)
791 {
792         struct ehca_cpu_comp_task *cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
793         LIST_HEAD(list);
794         struct ehca_cq *cq;
795         unsigned long flags_cct;
796
797         spin_lock_irqsave(&cct->task_lock, flags_cct);
798
799         list_splice_init(&cct->cq_list, &list);
800
801         while (!list_empty(&list)) {
802                 cq = list_entry(cct->cq_list.next, struct ehca_cq, entry);
803
804                 list_del(&cq->entry);
805                 __queue_comp_task(cq, per_cpu_ptr(pool->cpu_comp_tasks,
806                                                   smp_processor_id()));
807         }
808
809         spin_unlock_irqrestore(&cct->task_lock, flags_cct);
810
811 }
812
813 static int __cpuinit comp_pool_callback(struct notifier_block *nfb,
814                                         unsigned long action,
815                                         void *hcpu)
816 {
817         unsigned int cpu = (unsigned long)hcpu;
818         struct ehca_cpu_comp_task *cct;
819
820         switch (action) {
821         case CPU_UP_PREPARE:
822         case CPU_UP_PREPARE_FROZEN:
823                 ehca_gen_dbg("CPU: %x (CPU_PREPARE)", cpu);
824                 if (!create_comp_task(pool, cpu)) {
825                         ehca_gen_err("Can't create comp_task for cpu: %x", cpu);
826                         return NOTIFY_BAD;
827                 }
828                 break;
829         case CPU_UP_CANCELED:
830         case CPU_UP_CANCELED_FROZEN:
831                 ehca_gen_dbg("CPU: %x (CPU_CANCELED)", cpu);
832                 cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
833                 kthread_bind(cct->task, any_online_cpu(cpu_online_map));
834                 destroy_comp_task(pool, cpu);
835                 break;
836         case CPU_ONLINE:
837         case CPU_ONLINE_FROZEN:
838                 ehca_gen_dbg("CPU: %x (CPU_ONLINE)", cpu);
839                 cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
840                 kthread_bind(cct->task, cpu);
841                 wake_up_process(cct->task);
842                 break;
843         case CPU_DOWN_PREPARE:
844         case CPU_DOWN_PREPARE_FROZEN:
845                 ehca_gen_dbg("CPU: %x (CPU_DOWN_PREPARE)", cpu);
846                 break;
847         case CPU_DOWN_FAILED:
848         case CPU_DOWN_FAILED_FROZEN:
849                 ehca_gen_dbg("CPU: %x (CPU_DOWN_FAILED)", cpu);
850                 break;
851         case CPU_DEAD:
852         case CPU_DEAD_FROZEN:
853                 ehca_gen_dbg("CPU: %x (CPU_DEAD)", cpu);
854                 destroy_comp_task(pool, cpu);
855                 take_over_work(pool, cpu);
856                 break;
857         }
858
859         return NOTIFY_OK;
860 }
861
862 static struct notifier_block comp_pool_callback_nb __cpuinitdata = {
863         .notifier_call  = comp_pool_callback,
864         .priority       = 0,
865 };
866
867 int ehca_create_comp_pool(void)
868 {
869         int cpu;
870         struct task_struct *task;
871
872         if (!ehca_scaling_code)
873                 return 0;
874
875         pool = kzalloc(sizeof(struct ehca_comp_pool), GFP_KERNEL);
876         if (pool == NULL)
877                 return -ENOMEM;
878
879         spin_lock_init(&pool->last_cpu_lock);
880         pool->last_cpu = any_online_cpu(cpu_online_map);
881
882         pool->cpu_comp_tasks = alloc_percpu(struct ehca_cpu_comp_task);
883         if (pool->cpu_comp_tasks == NULL) {
884                 kfree(pool);
885                 return -EINVAL;
886         }
887
888         for_each_online_cpu(cpu) {
889                 task = create_comp_task(pool, cpu);
890                 if (task) {
891                         kthread_bind(task, cpu);
892                         wake_up_process(task);
893                 }
894         }
895
896         register_hotcpu_notifier(&comp_pool_callback_nb);
897
898         printk(KERN_INFO "eHCA scaling code enabled\n");
899
900         return 0;
901 }
902
903 void ehca_destroy_comp_pool(void)
904 {
905         int i;
906
907         if (!ehca_scaling_code)
908                 return;
909
910         unregister_hotcpu_notifier(&comp_pool_callback_nb);
911
912         for (i = 0; i < NR_CPUS; i++) {
913                 if (cpu_online(i))
914                         destroy_comp_task(pool, i);
915         }
916         free_percpu(pool->cpu_comp_tasks);
917         kfree(pool);
918 }