arch/s390/oprofile/hwsampler.c

   1 /**
   2  * arch/s390/oprofile/hwsampler.c
   3  *
   4  * Copyright IBM Corp. 2010
   5  * Author: Heinz Graalfs <graalfs@de.ibm.com>
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/smp.h>
  11 #include <linux/errno.h>
  12 #include <linux/workqueue.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/notifier.h>
  15 #include <linux/cpu.h>
  16 #include <linux/semaphore.h>
  17 #include <linux/oom.h>
  18 #include <linux/oprofile.h>
  19
  20 #include <asm/lowcore.h>
  21 #include <asm/s390_ext.h>
  22
  23 #include "hwsampler.h"
  24
  25 #define MAX_NUM_SDB 511
  26 #define MIN_NUM_SDB 1
  27
  28 #define ALERT_REQ_MASK   0x4000000000000000ul
  29 #define BUFFER_FULL_MASK 0x8000000000000000ul
  30
  31 #define EI_IEA      (1 << 31)   /* invalid entry address              */
  32 #define EI_ISE      (1 << 30)   /* incorrect SDBT entry               */
  33 #define EI_PRA      (1 << 29)   /* program request alert              */
  34 #define EI_SACA     (1 << 23)   /* sampler authorization change alert */
  35 #define EI_LSDA     (1 << 22)   /* loss of sample data alert          */
  36
  37 DECLARE_PER_CPU(struct hws_cpu_buffer, sampler_cpu_buffer);
  38
  39 struct hws_execute_parms {
  40         void *buffer;
  41         signed int rc;
  42 };
  43
  44 DEFINE_PER_CPU(struct hws_cpu_buffer, sampler_cpu_buffer);
  45 EXPORT_PER_CPU_SYMBOL(sampler_cpu_buffer);
  46
  47 static DEFINE_MUTEX(hws_sem);
  48 static DEFINE_MUTEX(hws_sem_oom);
  49
  50 static unsigned char hws_flush_all;
  51 static unsigned int hws_oom;
  52 static struct workqueue_struct *hws_wq;
  53
  54 static unsigned int hws_state;
  55 enum {
  56         HWS_INIT = 1,
  57         HWS_DEALLOCATED,
  58         HWS_STOPPED,
  59         HWS_STARTED,
  60         HWS_STOPPING };
  61
  62 /* set to 1 if called by kernel during memory allocation */
  63 static unsigned char oom_killer_was_active;
  64 /* size of SDBT and SDB as of allocate API */
  65 static unsigned long num_sdbt = 100;
  66 static unsigned long num_sdb = 511;
  67 /* sampling interval (machine cycles) */
  68 static unsigned long interval;
  69
  70 static unsigned long min_sampler_rate;
  71 static unsigned long max_sampler_rate;
  72
  73 static int ssctl(void *buffer)
  74 {
  75         int cc;
  76
  77         /* set in order to detect a program check */
  78         cc = 1;
  79
  80         asm volatile(
  81                 "0: .insn s,0xB2870000,0(%1)\n"
  82                 "1: ipm %0\n"
  83                 "   srl %0,28\n"
  84                 "2:\n"
  85                 EX_TABLE(0b, 2b) EX_TABLE(1b, 2b)
  86                 : "+d" (cc), "+a" (buffer)
  87                 : "m" (*((struct hws_ssctl_request_block *)buffer))
  88                 : "cc", "memory");
  89
  90         return cc ? -EINVAL : 0 ;
  91 }
  92
  93 static int qsi(void *buffer)
  94 {
  95         int cc;
  96         cc = 1;
  97
  98         asm volatile(
  99                 "0: .insn s,0xB2860000,0(%1)\n"
 100                 "1: lhi %0,0\n"
 101                 "2:\n"
 102                 EX_TABLE(0b, 2b) EX_TABLE(1b, 2b)
 103                 : "=d" (cc), "+a" (buffer)
 104                 : "m" (*((struct hws_qsi_info_block *)buffer))
 105                 : "cc", "memory");
 106
 107         return cc ? -EINVAL : 0;
 108 }
 109
 110 static void execute_qsi(void *parms)
 111 {
 112         struct hws_execute_parms *ep = parms;
 113
 114         ep->rc = qsi(ep->buffer);
 115 }
 116
 117 static void execute_ssctl(void *parms)
 118 {
 119         struct hws_execute_parms *ep = parms;
 120
 121         ep->rc = ssctl(ep->buffer);
 122 }
 123
 124 static int smp_ctl_ssctl_stop(int cpu)
 125 {
 126         int rc;
 127         struct hws_execute_parms ep;
 128         struct hws_cpu_buffer *cb;
 129
 130         cb = &per_cpu(sampler_cpu_buffer, cpu);
 131
 132         cb->ssctl.es = 0;
 133         cb->ssctl.cs = 0;
 134
 135         ep.buffer = &cb->ssctl;
 136         smp_call_function_single(cpu, execute_ssctl, &ep, 1);
 137         rc = ep.rc;
 138         if (rc) {
 139                 printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
 140                 dump_stack();
 141         }
 142
 143         ep.buffer = &cb->qsi;
 144         smp_call_function_single(cpu, execute_qsi, &ep, 1);
 145
 146         if (cb->qsi.es || cb->qsi.cs) {
 147                 printk(KERN_EMERG "CPUMF sampling did not stop properly.\n");
 148                 dump_stack();
 149         }
 150
 151         return rc;
 152 }
 153
 154 static int smp_ctl_ssctl_deactivate(int cpu)
 155 {
 156         int rc;
 157         struct hws_execute_parms ep;
 158         struct hws_cpu_buffer *cb;
 159
 160         cb = &per_cpu(sampler_cpu_buffer, cpu);
 161
 162         cb->ssctl.es = 1;
 163         cb->ssctl.cs = 0;
 164
 165         ep.buffer = &cb->ssctl;
 166         smp_call_function_single(cpu, execute_ssctl, &ep, 1);
 167         rc = ep.rc;
 168         if (rc)
 169                 printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
 170
 171         ep.buffer = &cb->qsi;
 172         smp_call_function_single(cpu, execute_qsi, &ep, 1);
 173
 174         if (cb->qsi.cs)
 175                 printk(KERN_EMERG "CPUMF sampling was not set inactive.\n");
 176
 177         return rc;
 178 }
 179
 180 static int smp_ctl_ssctl_enable_activate(int cpu, unsigned long interval)
 181 {
 182         int rc;
 183         struct hws_execute_parms ep;
 184         struct hws_cpu_buffer *cb;
 185
 186         cb = &per_cpu(sampler_cpu_buffer, cpu);
 187
 188         cb->ssctl.h = 1;
 189         cb->ssctl.tear = cb->first_sdbt;
 190         cb->ssctl.dear = *(unsigned long *) cb->first_sdbt;
 191         cb->ssctl.interval = interval;
 192         cb->ssctl.es = 1;
 193         cb->ssctl.cs = 1;
 194
 195         ep.buffer = &cb->ssctl;
 196         smp_call_function_single(cpu, execute_ssctl, &ep, 1);
 197         rc = ep.rc;
 198         if (rc)
 199                 printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
 200
 201         ep.buffer = &cb->qsi;
 202         smp_call_function_single(cpu, execute_qsi, &ep, 1);
 203         if (ep.rc)
 204                 printk(KERN_ERR "hwsampler: CPU %d CPUMF QSI failed.\n", cpu);
 205
 206         return rc;
 207 }
 208
 209 static int smp_ctl_qsi(int cpu)
 210 {
 211         struct hws_execute_parms ep;
 212         struct hws_cpu_buffer *cb;
 213
 214         cb = &per_cpu(sampler_cpu_buffer, cpu);
 215
 216         ep.buffer = &cb->qsi;
 217         smp_call_function_single(cpu, execute_qsi, &ep, 1);
 218
 219         return ep.rc;
 220 }
 221
 222 static inline unsigned long *trailer_entry_ptr(unsigned long v)
 223 {
 224         void *ret;
 225
 226         ret = (void *)v;
 227         ret += PAGE_SIZE;
 228         ret -= sizeof(struct hws_trailer_entry);
 229
 230         return (unsigned long *) ret;
 231 }
 232
 233 /* prototypes for external interrupt handler and worker */
 234 static void hws_ext_handler(unsigned int ext_int_code,
 235                                 unsigned int param32, unsigned long param64);
 236
 237 static void worker(struct work_struct *work);
 238
 239 static void add_samples_to_oprofile(unsigned cpu, unsigned long *,
 240                                 unsigned long *dear);
 241
 242 static void init_all_cpu_buffers(void)
 243 {
 244         int cpu;
 245         struct hws_cpu_buffer *cb;
 246
 247         for_each_online_cpu(cpu) {
 248                 cb = &per_cpu(sampler_cpu_buffer, cpu);
 249                 memset(cb, 0, sizeof(struct hws_cpu_buffer));
 250         }
 251 }
 252
 253 static int is_link_entry(unsigned long *s)
 254 {
 255         return *s & 0x1ul ? 1 : 0;
 256 }
 257
 258 static unsigned long *get_next_sdbt(unsigned long *s)
 259 {
 260         return (unsigned long *) (*s & ~0x1ul);
 261 }
 262
 263 static int prepare_cpu_buffers(void)
 264 {
 265         int cpu;
 266         int rc;
 267         struct hws_cpu_buffer *cb;
 268
 269         rc = 0;
 270         for_each_online_cpu(cpu) {
 271                 cb = &per_cpu(sampler_cpu_buffer, cpu);
 272                 atomic_set(&cb->ext_params, 0);
 273                 cb->worker_entry = 0;
 274                 cb->sample_overflow = 0;
 275                 cb->req_alert = 0;
 276                 cb->incorrect_sdbt_entry = 0;
 277                 cb->invalid_entry_address = 0;
 278                 cb->loss_of_sample_data = 0;
 279                 cb->sample_auth_change_alert = 0;
 280                 cb->finish = 0;
 281                 cb->oom = 0;
 282                 cb->stop_mode = 0;
 283         }
 284
 285         return rc;
 286 }
 287
 288 /*
 289  * allocate_sdbt() - allocate sampler memory
 290  * @cpu: the cpu for which sampler memory is allocated
 291  *
 292  * A 4K page is allocated for each requested SDBT.
 293  * A maximum of 511 4K pages are allocated for the SDBs in each of the SDBTs.
 294  * Set ALERT_REQ mask in each SDBs trailer.
 295  * Returns zero if successful, <0 otherwise.
 296  */
 297 static int allocate_sdbt(int cpu)
 298 {
 299         int j, k, rc;
 300         unsigned long *sdbt;
 301         unsigned long  sdb;
 302         unsigned long *tail;
 303         unsigned long *trailer;
 304         struct hws_cpu_buffer *cb;
 305
 306         cb = &per_cpu(sampler_cpu_buffer, cpu);
 307
 308         if (cb->first_sdbt)
 309                 return -EINVAL;
 310
 311         sdbt = NULL;
 312         tail = sdbt;
 313
 314         for (j = 0; j < num_sdbt; j++) {
 315                 sdbt = (unsigned long *)get_zeroed_page(GFP_KERNEL);
 316
 317                 mutex_lock(&hws_sem_oom);
 318                 /* OOM killer might have been activated */
 319                 barrier();
 320                 if (oom_killer_was_active || !sdbt) {
 321                         if (sdbt)
 322                                 free_page((unsigned long)sdbt);
 323
 324                         goto allocate_sdbt_error;
 325                 }
 326                 if (cb->first_sdbt == 0)
 327                         cb->first_sdbt = (unsigned long)sdbt;
 328
 329                 /* link current page to tail of chain */
 330                 if (tail)
 331                         *tail = (unsigned long)(void *)sdbt + 1;
 332
 333                 mutex_unlock(&hws_sem_oom);
 334
 335                 for (k = 0; k < num_sdb; k++) {
 336                         /* get and set SDB page */
 337                         sdb = get_zeroed_page(GFP_KERNEL);
 338
 339                         mutex_lock(&hws_sem_oom);
 340                         /* OOM killer might have been activated */
 341                         barrier();
 342                         if (oom_killer_was_active || !sdb) {
 343                                 if (sdb)
 344                                         free_page(sdb);
 345
 346                                 goto allocate_sdbt_error;
 347                         }
 348                         *sdbt = sdb;
 349                         trailer = trailer_entry_ptr(*sdbt);
 350                         *trailer = ALERT_REQ_MASK;
 351                         sdbt++;
 352                         mutex_unlock(&hws_sem_oom);
 353                 }
 354                 tail = sdbt;
 355         }
 356         mutex_lock(&hws_sem_oom);
 357         if (oom_killer_was_active)
 358                 goto allocate_sdbt_error;
 359
 360         rc = 0;
 361         if (tail)
 362                 *tail = (unsigned long)
 363                         ((void *)cb->first_sdbt) + 1;
 364
 365 allocate_sdbt_exit:
 366         mutex_unlock(&hws_sem_oom);
 367         return rc;
 368
 369 allocate_sdbt_error:
 370         rc = -ENOMEM;
 371         goto allocate_sdbt_exit;
 372 }
 373
 374 /*
 375  * deallocate_sdbt() - deallocate all sampler memory
 376  *
 377  * For each online CPU all SDBT trees are deallocated.
 378  * Returns the number of freed pages.
 379  */
 380 static int deallocate_sdbt(void)
 381 {
 382         int cpu;
 383         int counter;
 384
 385         counter = 0;
 386
 387         for_each_online_cpu(cpu) {
 388                 unsigned long start;
 389                 unsigned long sdbt;
 390                 unsigned long *curr;
 391                 struct hws_cpu_buffer *cb;
 392
 393                 cb = &per_cpu(sampler_cpu_buffer, cpu);
 394
 395                 if (!cb->first_sdbt)
 396                         continue;
 397
 398                 sdbt = cb->first_sdbt;
 399                 curr = (unsigned long *) sdbt;
 400                 start = sdbt;
 401
 402                 /* we'll free the SDBT after all SDBs are processed... */
 403                 while (1) {
 404                         if (!*curr || !sdbt)
 405                                 break;
 406
 407                         /* watch for link entry reset if found */
 408                         if (is_link_entry(curr)) {
 409                                 curr = get_next_sdbt(curr);
 410                                 if (sdbt)
 411                                         free_page(sdbt);
 412
 413                                 /* we are done if we reach the start */
 414                                 if ((unsigned long) curr == start)
 415                                         break;
 416                                 else
 417                                         sdbt = (unsigned long) curr;
 418                         } else {
 419                                 /* process SDB pointer */
 420                                 if (*curr) {
 421                                         free_page(*curr);
 422                                         curr++;
 423                                 }
 424                         }
 425                         counter++;
 426                 }
 427                 cb->first_sdbt = 0;
 428         }
 429         return counter;
 430 }
 431
 432 static int start_sampling(int cpu)
 433 {
 434         int rc;
 435         struct hws_cpu_buffer *cb;
 436
 437         cb = &per_cpu(sampler_cpu_buffer, cpu);
 438         rc = smp_ctl_ssctl_enable_activate(cpu, interval);
 439         if (rc) {
 440                 printk(KERN_INFO "hwsampler: CPU %d ssctl failed.\n", cpu);
 441                 goto start_exit;
 442         }
 443
 444         rc = -EINVAL;
 445         if (!cb->qsi.es) {
 446                 printk(KERN_INFO "hwsampler: CPU %d ssctl not enabled.\n", cpu);
 447                 goto start_exit;
 448         }
 449
 450         if (!cb->qsi.cs) {
 451                 printk(KERN_INFO "hwsampler: CPU %d ssctl not active.\n", cpu);
 452                 goto start_exit;
 453         }
 454
 455         printk(KERN_INFO
 456                 "hwsampler: CPU %d, CPUMF Sampling started, interval %lu.\n",
 457                 cpu, interval);
 458
 459         rc = 0;
 460
 461 start_exit:
 462         return rc;
 463 }
 464
 465 static int stop_sampling(int cpu)
 466 {
 467         unsigned long v;
 468         int rc;
 469         struct hws_cpu_buffer *cb;
 470
 471         rc = smp_ctl_qsi(cpu);
 472         WARN_ON(rc);
 473
 474         cb = &per_cpu(sampler_cpu_buffer, cpu);
 475         if (!rc && !cb->qsi.es)
 476                 printk(KERN_INFO "hwsampler: CPU %d, already stopped.\n", cpu);
 477
 478         rc = smp_ctl_ssctl_stop(cpu);
 479         if (rc) {
 480                 printk(KERN_INFO "hwsampler: CPU %d, ssctl stop error %d.\n",
 481                                 cpu, rc);
 482                 goto stop_exit;
 483         }
 484
 485         printk(KERN_INFO "hwsampler: CPU %d, CPUMF Sampling stopped.\n", cpu);
 486
 487 stop_exit:
 488         v = cb->req_alert;
 489         if (v)
 490                 printk(KERN_ERR "hwsampler: CPU %d CPUMF Request alert,"
 491                                 " count=%lu.\n", cpu, v);
 492
 493         v = cb->loss_of_sample_data;
 494         if (v)
 495                 printk(KERN_ERR "hwsampler: CPU %d CPUMF Loss of sample data,"
 496                                 " count=%lu.\n", cpu, v);
 497
 498         v = cb->invalid_entry_address;
 499         if (v)
 500                 printk(KERN_ERR "hwsampler: CPU %d CPUMF Invalid entry address,"
 501                                 " count=%lu.\n", cpu, v);
 502
 503         v = cb->incorrect_sdbt_entry;
 504         if (v)
 505                 printk(KERN_ERR
 506                                 "hwsampler: CPU %d CPUMF Incorrect SDBT address,"
 507                                 " count=%lu.\n", cpu, v);
 508
 509         v = cb->sample_auth_change_alert;
 510         if (v)
 511                 printk(KERN_ERR
 512                                 "hwsampler: CPU %d CPUMF Sample authorization change,"
 513                                 " count=%lu.\n", cpu, v);
 514
 515         return rc;
 516 }
 517
 518 static int check_hardware_prerequisites(void)
 519 {
 520         if (!test_facility(68))
 521                 return -EOPNOTSUPP;
 522         return 0;
 523 }
 524 /*
 525  * hws_oom_callback() - the OOM callback function
 526  *
 527  * In case the callback is invoked during memory allocation for the
 528  *  hw sampler, all obtained memory is deallocated and a flag is set
 529  *  so main sampler memory allocation can exit with a failure code.
 530  * In case the callback is invoked during sampling the hw sampler
 531  *  is deactivated for all CPUs.
 532  */
 533 static int hws_oom_callback(struct notifier_block *nfb,
 534         unsigned long dummy, void *parm)
 535 {
 536         unsigned long *freed;
 537         int cpu;
 538         struct hws_cpu_buffer *cb;
 539
 540         freed = parm;
 541
 542         mutex_lock(&hws_sem_oom);
 543
 544         if (hws_state == HWS_DEALLOCATED) {
 545                 /* during memory allocation */
 546                 if (oom_killer_was_active == 0) {
 547                         oom_killer_was_active = 1;
 548                         *freed += deallocate_sdbt();
 549                 }
 550         } else {
 551                 int i;
 552                 cpu = get_cpu();
 553                 cb = &per_cpu(sampler_cpu_buffer, cpu);
 554
 555                 if (!cb->oom) {
 556                         for_each_online_cpu(i) {
 557                                 smp_ctl_ssctl_deactivate(i);
 558                                 cb->oom = 1;
 559                         }
 560                         cb->finish = 1;
 561
 562                         printk(KERN_INFO
 563                                 "hwsampler: CPU %d, OOM notify during CPUMF Sampling.\n",
 564                                 cpu);
 565                 }
 566         }
 567
 568         mutex_unlock(&hws_sem_oom);
 569
 570         return NOTIFY_OK;
 571 }
 572
 573 static struct notifier_block hws_oom_notifier = {
 574         .notifier_call = hws_oom_callback
 575 };
 576
 577 static int hws_cpu_callback(struct notifier_block *nfb,
 578         unsigned long action, void *hcpu)
 579 {
 580         /* We do not have sampler space available for all possible CPUs.
 581            All CPUs should be online when hw sampling is activated. */
 582         return NOTIFY_BAD;
 583 }
 584
 585 static struct notifier_block hws_cpu_notifier = {
 586         .notifier_call = hws_cpu_callback
 587 };
 588
 589 /**
 590  * hwsampler_deactivate() - set hardware sampling temporarily inactive
 591  * @cpu:  specifies the CPU to be set inactive.
 592  *
 593  * Returns 0 on success, !0 on failure.
 594  */
 595 int hwsampler_deactivate(unsigned int cpu)
 596 {
 597         /*
 598          * Deactivate hw sampling temporarily and flush the buffer
 599          * by pushing all the pending samples to oprofile buffer.
 600          *
 601          * This function can be called under one of the following conditions:
 602          *     Memory unmap, task is exiting.
 603          */
 604         int rc;
 605         struct hws_cpu_buffer *cb;
 606
 607         rc = 0;
 608         mutex_lock(&hws_sem);
 609
 610         cb = &per_cpu(sampler_cpu_buffer, cpu);
 611         if (hws_state == HWS_STARTED) {
 612                 rc = smp_ctl_qsi(cpu);
 613                 WARN_ON(rc);
 614                 if (cb->qsi.cs) {
 615                         rc = smp_ctl_ssctl_deactivate(cpu);
 616                         if (rc) {
 617                                 printk(KERN_INFO
 618                                 "hwsampler: CPU %d, CPUMF Deactivation failed.\n", cpu);
 619                                 cb->finish = 1;
 620                                 hws_state = HWS_STOPPING;
 621                         } else  {
 622                                 hws_flush_all = 1;
 623                                 /* Add work to queue to read pending samples.*/
 624                                 queue_work_on(cpu, hws_wq, &cb->worker);
 625                         }
 626                 }
 627         }
 628         mutex_unlock(&hws_sem);
 629
 630         if (hws_wq)
 631                 flush_workqueue(hws_wq);
 632
 633         return rc;
 634 }
 635
 636 /**
 637  * hwsampler_activate() - activate/resume hardware sampling which was deactivated
 638  * @cpu:  specifies the CPU to be set active.
 639  *
 640  * Returns 0 on success, !0 on failure.
 641  */
 642 int hwsampler_activate(unsigned int cpu)
 643 {
 644         /*
 645          * Re-activate hw sampling. This should be called in pair with
 646          * hwsampler_deactivate().
 647          */
 648         int rc;
 649         struct hws_cpu_buffer *cb;
 650
 651         rc = 0;
 652         mutex_lock(&hws_sem);
 653
 654         cb = &per_cpu(sampler_cpu_buffer, cpu);
 655         if (hws_state == HWS_STARTED) {
 656                 rc = smp_ctl_qsi(cpu);
 657                 WARN_ON(rc);
 658                 if (!cb->qsi.cs) {
 659                         hws_flush_all = 0;
 660                         rc = smp_ctl_ssctl_enable_activate(cpu, interval);
 661                         if (rc) {
 662                                 printk(KERN_ERR
 663                                 "CPU %d, CPUMF activate sampling failed.\n",
 664                                          cpu);
 665                         }
 666                 }
 667         }
 668
 669         mutex_unlock(&hws_sem);
 670
 671         return rc;
 672 }
 673
 674 static void hws_ext_handler(unsigned int ext_int_code,
 675                             unsigned int param32, unsigned long param64)
 676 {
 677         int cpu;
 678         struct hws_cpu_buffer *cb;
 679
 680         cpu = smp_processor_id();
 681         cb = &per_cpu(sampler_cpu_buffer, cpu);
 682
 683         atomic_xchg(
 684                         &cb->ext_params,
 685                         atomic_read(&cb->ext_params)
 686                                 | S390_lowcore.ext_params);
 687
 688         if (hws_wq)
 689                 queue_work(hws_wq, &cb->worker);
 690 }
 691
 692 static int check_qsi_on_setup(void)
 693 {
 694         int rc;
 695         unsigned int cpu;
 696         struct hws_cpu_buffer *cb;
 697
 698         for_each_online_cpu(cpu) {
 699                 cb = &per_cpu(sampler_cpu_buffer, cpu);
 700                 rc = smp_ctl_qsi(cpu);
 701                 WARN_ON(rc);
 702                 if (rc)
 703                         return -EOPNOTSUPP;
 704
 705                 if (!cb->qsi.as) {
 706                         printk(KERN_INFO "hwsampler: CPUMF sampling is not authorized.\n");
 707                         return -EINVAL;
 708                 }
 709
 710                 if (cb->qsi.es) {
 711                         printk(KERN_WARNING "hwsampler: CPUMF is still enabled.\n");
 712                         rc = smp_ctl_ssctl_stop(cpu);
 713                         if (rc)
 714                                 return -EINVAL;
 715
 716                         printk(KERN_INFO
 717                                 "CPU %d, CPUMF Sampling stopped now.\n", cpu);
 718                 }
 719         }
 720         return 0;
 721 }
 722
 723 static int check_qsi_on_start(void)
 724 {
 725         unsigned int cpu;
 726         int rc;
 727         struct hws_cpu_buffer *cb;
 728
 729         for_each_online_cpu(cpu) {
 730                 cb = &per_cpu(sampler_cpu_buffer, cpu);
 731                 rc = smp_ctl_qsi(cpu);
 732                 WARN_ON(rc);
 733
 734                 if (!cb->qsi.as)
 735                         return -EINVAL;
 736
 737                 if (cb->qsi.es)
 738                         return -EINVAL;
 739
 740                 if (cb->qsi.cs)
 741                         return -EINVAL;
 742         }
 743         return 0;
 744 }
 745
 746 static void worker_on_start(unsigned int cpu)
 747 {
 748         struct hws_cpu_buffer *cb;
 749
 750         cb = &per_cpu(sampler_cpu_buffer, cpu);
 751         cb->worker_entry = cb->first_sdbt;
 752 }
 753
 754 static int worker_check_error(unsigned int cpu, int ext_params)
 755 {
 756         int rc;
 757         unsigned long *sdbt;
 758         struct hws_cpu_buffer *cb;
 759
 760         rc = 0;
 761         cb = &per_cpu(sampler_cpu_buffer, cpu);
 762         sdbt = (unsigned long *) cb->worker_entry;
 763
 764         if (!sdbt || !*sdbt)
 765                 return -EINVAL;
 766
 767         if (ext_params & EI_IEA)
 768                 cb->req_alert++;
 769
 770         if (ext_params & EI_LSDA)
 771                 cb->loss_of_sample_data++;
 772
 773         if (ext_params & EI_IEA) {
 774                 cb->invalid_entry_address++;
 775                 rc = -EINVAL;
 776         }
 777
 778         if (ext_params & EI_ISE) {
 779                 cb->incorrect_sdbt_entry++;
 780                 rc = -EINVAL;
 781         }
 782
 783         if (ext_params & EI_SACA) {
 784                 cb->sample_auth_change_alert++;
 785                 rc = -EINVAL;
 786         }
 787
 788         return rc;
 789 }
 790
 791 static void worker_on_finish(unsigned int cpu)
 792 {
 793         int rc, i;
 794         struct hws_cpu_buffer *cb;
 795
 796         cb = &per_cpu(sampler_cpu_buffer, cpu);
 797
 798         if (cb->finish) {
 799                 rc = smp_ctl_qsi(cpu);
 800                 WARN_ON(rc);
 801                 if (cb->qsi.es) {
 802                         printk(KERN_INFO
 803                                 "hwsampler: CPU %d, CPUMF Stop/Deactivate sampling.\n",
 804                                 cpu);
 805                         rc = smp_ctl_ssctl_stop(cpu);
 806                         if (rc)
 807                                 printk(KERN_INFO
 808                                         "hwsampler: CPU %d, CPUMF Deactivation failed.\n",
 809                                         cpu);
 810
 811                         for_each_online_cpu(i) {
 812                                 if (i == cpu)
 813                                         continue;
 814                                 if (!cb->finish) {
 815                                         cb->finish = 1;
 816                                         queue_work_on(i, hws_wq,
 817                                                 &cb->worker);
 818                                 }
 819                         }
 820                 }
 821         }
 822 }
 823
 824 static void worker_on_interrupt(unsigned int cpu)
 825 {
 826         unsigned long *sdbt;
 827         unsigned char done;
 828         struct hws_cpu_buffer *cb;
 829
 830         cb = &per_cpu(sampler_cpu_buffer, cpu);
 831
 832         sdbt = (unsigned long *) cb->worker_entry;
 833
 834         done = 0;
 835         /* do not proceed if stop was entered,
 836          * forget the buffers not yet processed */
 837         while (!done && !cb->stop_mode) {
 838                 unsigned long *trailer;
 839                 struct hws_trailer_entry *te;
 840                 unsigned long *dear = 0;
 841
 842                 trailer = trailer_entry_ptr(*sdbt);
 843                 /* leave loop if no more work to do */
 844                 if (!(*trailer & BUFFER_FULL_MASK)) {
 845                         done = 1;
 846                         if (!hws_flush_all)
 847                                 continue;
 848                 }
 849
 850                 te = (struct hws_trailer_entry *)trailer;
 851                 cb->sample_overflow += te->overflow;
 852
 853                 add_samples_to_oprofile(cpu, sdbt, dear);
 854
 855                 /* reset trailer */
 856                 xchg((unsigned char *) te, 0x40);
 857
 858                 /* advance to next sdb slot in current sdbt */
 859                 sdbt++;
 860                 /* in case link bit is set use address w/o link bit */
 861                 if (is_link_entry(sdbt))
 862                         sdbt = get_next_sdbt(sdbt);
 863
 864                 cb->worker_entry = (unsigned long)sdbt;
 865         }
 866 }
 867
 868 static void add_samples_to_oprofile(unsigned int cpu, unsigned long *sdbt,
 869                 unsigned long *dear)
 870 {
 871         struct hws_data_entry *sample_data_ptr;
 872         unsigned long *trailer;
 873
 874         trailer = trailer_entry_ptr(*sdbt);
 875         if (dear) {
 876                 if (dear > trailer)
 877                         return;
 878                 trailer = dear;
 879         }
 880
 881         sample_data_ptr = (struct hws_data_entry *)(*sdbt);
 882
 883         while ((unsigned long *)sample_data_ptr < trailer) {
 884                 struct pt_regs *regs = NULL;
 885                 struct task_struct *tsk = NULL;
 886
 887                 /*
 888                  * Check sampling mode, 1 indicates basic (=customer) sampling
 889                  * mode.
 890                  */
 891                 if (sample_data_ptr->def != 1) {
 892                         /* sample slot is not yet written */
 893                         break;
 894                 } else {
 895                         /* make sure we don't use it twice,
 896                          * the next time the sampler will set it again */
 897                         sample_data_ptr->def = 0;
 898                 }
 899
 900                 /* Get pt_regs. */
 901                 if (sample_data_ptr->P == 1) {
 902                         /* userspace sample */
 903                         unsigned int pid = sample_data_ptr->prim_asn;
 904                         rcu_read_lock();
 905                         tsk = pid_task(find_vpid(pid), PIDTYPE_PID);
 906                         if (tsk)
 907                                 regs = task_pt_regs(tsk);
 908                         rcu_read_unlock();
 909                 } else {
 910                         /* kernelspace sample */
 911                         regs = task_pt_regs(current);
 912                 }
 913
 914                 mutex_lock(&hws_sem);
 915                 oprofile_add_ext_hw_sample(sample_data_ptr->ia, regs, 0,
 916                                 !sample_data_ptr->P, tsk);
 917                 mutex_unlock(&hws_sem);
 918
 919                 sample_data_ptr++;
 920         }
 921 }
 922
 923 static void worker(struct work_struct *work)
 924 {
 925         unsigned int cpu;
 926         int ext_params;
 927         struct hws_cpu_buffer *cb;
 928
 929         cb = container_of(work, struct hws_cpu_buffer, worker);
 930         cpu = smp_processor_id();
 931         ext_params = atomic_xchg(&cb->ext_params, 0);
 932
 933         if (!cb->worker_entry)
 934                 worker_on_start(cpu);
 935
 936         if (worker_check_error(cpu, ext_params))
 937                 return;
 938
 939         if (!cb->finish)
 940                 worker_on_interrupt(cpu);
 941
 942         if (cb->finish)
 943                 worker_on_finish(cpu);
 944 }
 945
 946 /**
 947  * hwsampler_allocate() - allocate memory for the hardware sampler
 948  * @sdbt:  number of SDBTs per online CPU (must be > 0)
 949  * @sdb:   number of SDBs per SDBT (minimum 1, maximum 511)
 950  *
 951  * Returns 0 on success, !0 on failure.
 952  */
 953 int hwsampler_allocate(unsigned long sdbt, unsigned long sdb)
 954 {
 955         int cpu, rc;
 956         mutex_lock(&hws_sem);
 957
 958         rc = -EINVAL;
 959         if (hws_state != HWS_DEALLOCATED)
 960                 goto allocate_exit;
 961
 962         if (sdbt < 1)
 963                 goto allocate_exit;
 964
 965         if (sdb > MAX_NUM_SDB || sdb < MIN_NUM_SDB)
 966                 goto allocate_exit;
 967
 968         num_sdbt = sdbt;
 969         num_sdb = sdb;
 970
 971         oom_killer_was_active = 0;
 972         register_oom_notifier(&hws_oom_notifier);
 973
 974         for_each_online_cpu(cpu) {
 975                 if (allocate_sdbt(cpu)) {
 976                         unregister_oom_notifier(&hws_oom_notifier);
 977                         goto allocate_error;
 978                 }
 979         }
 980         unregister_oom_notifier(&hws_oom_notifier);
 981         if (oom_killer_was_active)
 982                 goto allocate_error;
 983
 984         hws_state = HWS_STOPPED;
 985         rc = 0;
 986
 987 allocate_exit:
 988         mutex_unlock(&hws_sem);
 989         return rc;
 990
 991 allocate_error:
 992         rc = -ENOMEM;
 993         printk(KERN_ERR "hwsampler: CPUMF Memory allocation failed.\n");
 994         goto allocate_exit;
 995 }
 996
 997 /**
 998  * hwsampler_deallocate() - deallocate hardware sampler memory
 999  *
1000  * Returns 0 on success, !0 on failure.
1001  */
1002 int hwsampler_deallocate()
1003 {
1004         int rc;
1005
1006         mutex_lock(&hws_sem);
1007
1008         rc = -EINVAL;
1009         if (hws_state != HWS_STOPPED)
1010                 goto deallocate_exit;
1011
1012         smp_ctl_clear_bit(0, 5); /* set bit 58 CR0 off */
1013         deallocate_sdbt();
1014
1015         hws_state = HWS_DEALLOCATED;
1016         rc = 0;
1017
1018 deallocate_exit:
1019         mutex_unlock(&hws_sem);
1020
1021         return rc;
1022 }
1023
1024 long hwsampler_query_min_interval(void)
1025 {
1026         if (min_sampler_rate)
1027                 return min_sampler_rate;
1028         else
1029                 return -EINVAL;
1030 }
1031
1032 long hwsampler_query_max_interval(void)
1033 {
1034         if (max_sampler_rate)
1035                 return max_sampler_rate;
1036         else
1037                 return -EINVAL;
1038 }
1039
1040 unsigned long hwsampler_get_sample_overflow_count(unsigned int cpu)
1041 {
1042         struct hws_cpu_buffer *cb;
1043
1044         cb = &per_cpu(sampler_cpu_buffer, cpu);
1045
1046         return cb->sample_overflow;
1047 }
1048
1049 int hwsampler_setup()
1050 {
1051         int rc;
1052         int cpu;
1053         struct hws_cpu_buffer *cb;
1054
1055         mutex_lock(&hws_sem);
1056
1057         rc = -EINVAL;
1058         if (hws_state)
1059                 goto setup_exit;
1060
1061         hws_state = HWS_INIT;
1062
1063         init_all_cpu_buffers();
1064
1065         rc = check_hardware_prerequisites();
1066         if (rc)
1067                 goto setup_exit;
1068
1069         rc = check_qsi_on_setup();
1070         if (rc)
1071                 goto setup_exit;
1072
1073         rc = -EINVAL;
1074         hws_wq = create_workqueue("hwsampler");
1075         if (!hws_wq)
1076                 goto setup_exit;
1077
1078         register_cpu_notifier(&hws_cpu_notifier);
1079
1080         for_each_online_cpu(cpu) {
1081                 cb = &per_cpu(sampler_cpu_buffer, cpu);
1082                 INIT_WORK(&cb->worker, worker);
1083                 rc = smp_ctl_qsi(cpu);
1084                 WARN_ON(rc);
1085                 if (min_sampler_rate != cb->qsi.min_sampl_rate) {
1086                         if (min_sampler_rate) {
1087                                 printk(KERN_WARNING
1088                                         "hwsampler: different min sampler rate values.\n");
1089                                 if (min_sampler_rate < cb->qsi.min_sampl_rate)
1090                                         min_sampler_rate =
1091                                                 cb->qsi.min_sampl_rate;
1092                         } else
1093                                 min_sampler_rate = cb->qsi.min_sampl_rate;
1094                 }
1095                 if (max_sampler_rate != cb->qsi.max_sampl_rate) {
1096                         if (max_sampler_rate) {
1097                                 printk(KERN_WARNING
1098                                         "hwsampler: different max sampler rate values.\n");
1099                                 if (max_sampler_rate > cb->qsi.max_sampl_rate)
1100                                         max_sampler_rate =
1101                                                 cb->qsi.max_sampl_rate;
1102                         } else
1103                                 max_sampler_rate = cb->qsi.max_sampl_rate;
1104                 }
1105         }
1106         register_external_interrupt(0x1407, hws_ext_handler);
1107
1108         hws_state = HWS_DEALLOCATED;
1109         rc = 0;
1110
1111 setup_exit:
1112         mutex_unlock(&hws_sem);
1113         return rc;
1114 }
1115
1116 int hwsampler_shutdown()
1117 {
1118         int rc;
1119
1120         mutex_lock(&hws_sem);
1121
1122         rc = -EINVAL;
1123         if (hws_state == HWS_DEALLOCATED || hws_state == HWS_STOPPED) {
1124                 mutex_unlock(&hws_sem);
1125
1126                 if (hws_wq)
1127                         flush_workqueue(hws_wq);
1128
1129                 mutex_lock(&hws_sem);
1130
1131                 if (hws_state == HWS_STOPPED) {
1132                         smp_ctl_clear_bit(0, 5); /* set bit 58 CR0 off */
1133                         deallocate_sdbt();
1134                 }
1135                 if (hws_wq) {
1136                         destroy_workqueue(hws_wq);
1137                         hws_wq = NULL;
1138                 }
1139
1140                 unregister_external_interrupt(0x1407, hws_ext_handler);
1141                 hws_state = HWS_INIT;
1142                 rc = 0;
1143         }
1144         mutex_unlock(&hws_sem);
1145
1146         unregister_cpu_notifier(&hws_cpu_notifier);
1147
1148         return rc;
1149 }
1150
1151 /**
1152  * hwsampler_start_all() - start hardware sampling on all online CPUs
1153  * @rate:  specifies the used interval when samples are taken
1154  *
1155  * Returns 0 on success, !0 on failure.
1156  */
1157 int hwsampler_start_all(unsigned long rate)
1158 {
1159         int rc, cpu;
1160
1161         mutex_lock(&hws_sem);
1162
1163         hws_oom = 0;
1164
1165         rc = -EINVAL;
1166         if (hws_state != HWS_STOPPED)
1167                 goto start_all_exit;
1168
1169         interval = rate;
1170
1171         /* fail if rate is not valid */
1172         if (interval < min_sampler_rate || interval > max_sampler_rate)
1173                 goto start_all_exit;
1174
1175         rc = check_qsi_on_start();
1176         if (rc)
1177                 goto start_all_exit;
1178
1179         rc = prepare_cpu_buffers();
1180         if (rc)
1181                 goto start_all_exit;
1182
1183         for_each_online_cpu(cpu) {
1184                 rc = start_sampling(cpu);
1185                 if (rc)
1186                         break;
1187         }
1188         if (rc) {
1189                 for_each_online_cpu(cpu) {
1190                         stop_sampling(cpu);
1191                 }
1192                 goto start_all_exit;
1193         }
1194         hws_state = HWS_STARTED;
1195         rc = 0;
1196
1197 start_all_exit:
1198         mutex_unlock(&hws_sem);
1199
1200         if (rc)
1201                 return rc;
1202
1203         register_oom_notifier(&hws_oom_notifier);
1204         hws_oom = 1;
1205         hws_flush_all = 0;
1206         /* now let them in, 1407 CPUMF external interrupts */
1207         smp_ctl_set_bit(0, 5); /* set CR0 bit 58 */
1208
1209         return 0;
1210 }
1211
1212 /**
1213  * hwsampler_stop_all() - stop hardware sampling on all online CPUs
1214  *
1215  * Returns 0 on success, !0 on failure.
1216  */
1217 int hwsampler_stop_all()
1218 {
1219         int tmp_rc, rc, cpu;
1220         struct hws_cpu_buffer *cb;
1221
1222         mutex_lock(&hws_sem);
1223
1224         rc = 0;
1225         if (hws_state == HWS_INIT) {
1226                 mutex_unlock(&hws_sem);
1227                 return rc;
1228         }
1229         hws_state = HWS_STOPPING;
1230         mutex_unlock(&hws_sem);
1231
1232         for_each_online_cpu(cpu) {
1233                 cb = &per_cpu(sampler_cpu_buffer, cpu);
1234                 cb->stop_mode = 1;
1235                 tmp_rc = stop_sampling(cpu);
1236                 if (tmp_rc)
1237                         rc = tmp_rc;
1238         }
1239
1240         if (hws_wq)
1241                 flush_workqueue(hws_wq);
1242
1243         mutex_lock(&hws_sem);
1244         if (hws_oom) {
1245                 unregister_oom_notifier(&hws_oom_notifier);
1246                 hws_oom = 0;
1247         }
1248         hws_state = HWS_STOPPED;
1249         mutex_unlock(&hws_sem);
1250
1251         return rc;
1252 }