drivers/xen/xenoprof/xenoprofile.c

   1 /**
   2  * @file xenoprofile.c
   3  *
   4  * @remark Copyright 2002 OProfile authors
   5  * @remark Read the file COPYING
   6  *
   7  * @author John Levon <levon@movementarian.org>
   8  *
   9  * Modified by Aravind Menon and Jose Renato Santos for Xen
  10  * These modifications are:
  11  * Copyright (C) 2005 Hewlett-Packard Co.
  12  *
  13  * Separated out arch-generic part
  14  * Copyright (c) 2006 Isaku Yamahata <yamahata at valinux co jp>
  15  *                    VA Linux Systems Japan K.K.
  16  */
  17
  18 #include <linux/init.h>
  19 #include <linux/notifier.h>
  20 #include <linux/smp.h>
  21 #include <linux/oprofile.h>
  22 #include <linux/sysdev.h>
  23 #include <linux/slab.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/vmalloc.h>
  26 #include <asm/pgtable.h>
  27 #include <xen/evtchn.h>
  28 #include <xen/xenoprof.h>
  29 #include <xen/driver_util.h>
  30 #include <xen/interface/xen.h>
  31 #include <xen/interface/xenoprof.h>
  32 #include "../../../drivers/oprofile/cpu_buffer.h"
  33 #include "../../../drivers/oprofile/event_buffer.h"
  34
  35 #define MAX_XENOPROF_SAMPLES 16
  36
  37 /* sample buffers shared with Xen */
  38 xenoprof_buf_t * xenoprof_buf[MAX_VIRT_CPUS];
  39 /* Shared buffer area */
  40 struct xenoprof_shared_buffer shared_buffer;
  41
  42 /* Passive sample buffers shared with Xen */
  43 xenoprof_buf_t *p_xenoprof_buf[MAX_OPROF_DOMAINS][MAX_VIRT_CPUS];
  44 /* Passive shared buffer area */
  45 struct xenoprof_shared_buffer p_shared_buffer[MAX_OPROF_DOMAINS];
  46
  47 static int xenoprof_start(void);
  48 static void xenoprof_stop(void);
  49
  50 static int xenoprof_enabled = 0;
  51 static int xenoprof_is_primary = 0;
  52 static int active_defined;
  53
  54 /* Number of buffers in shared area (one per VCPU) */
  55 int nbuf;
  56 /* Mappings of VIRQ_XENOPROF to irq number (per cpu) */
  57 int ovf_irq[NR_CPUS];
  58 /* cpu model type string - copied from Xen memory space on XENOPROF_init command */
  59 char cpu_type[XENOPROF_CPU_TYPE_SIZE];
  60
  61 #ifdef CONFIG_PM
  62
  63 static int xenoprof_suspend(struct sys_device * dev, pm_message_t state)
  64 {
  65         if (xenoprof_enabled == 1)
  66                 xenoprof_stop();
  67         return 0;
  68 }
  69
  70
  71 static int xenoprof_resume(struct sys_device * dev)
  72 {
  73         if (xenoprof_enabled == 1)
  74                 xenoprof_start();
  75         return 0;
  76 }
  77
  78
  79 static struct sysdev_class oprofile_sysclass = {
  80         set_kset_name("oprofile"),
  81         .resume         = xenoprof_resume,
  82         .suspend        = xenoprof_suspend
  83 };
  84
  85
  86 static struct sys_device device_oprofile = {
  87         .id     = 0,
  88         .cls    = &oprofile_sysclass,
  89 };
  90
  91
  92 static int __init init_driverfs(void)
  93 {
  94         int error;
  95         if (!(error = sysdev_class_register(&oprofile_sysclass)))
  96                 error = sysdev_register(&device_oprofile);
  97         return error;
  98 }
  99
 100
 101 static void exit_driverfs(void)
 102 {
 103         sysdev_unregister(&device_oprofile);
 104         sysdev_class_unregister(&oprofile_sysclass);
 105 }
 106
 107 #else
 108 #define init_driverfs() do { } while (0)
 109 #define exit_driverfs() do { } while (0)
 110 #endif /* CONFIG_PM */
 111
 112 unsigned long long oprofile_samples = 0;
 113 unsigned long long p_oprofile_samples = 0;
 114
 115 unsigned int pdomains;
 116 struct xenoprof_passive passive_domains[MAX_OPROF_DOMAINS];
 117
 118 static void xenoprof_add_pc(xenoprof_buf_t *buf, int is_passive)
 119 {
 120         int head, tail, size;
 121
 122         head = buf->event_head;
 123         tail = buf->event_tail;
 124         size = buf->event_size;
 125
 126         if (tail > head) {
 127                 while (tail < size) {
 128                         oprofile_add_pc(buf->event_log[tail].eip,
 129                                         buf->event_log[tail].mode,
 130                                         buf->event_log[tail].event);
 131                         if (!is_passive)
 132                                 oprofile_samples++;
 133                         else
 134                                 p_oprofile_samples++;
 135                         tail++;
 136                 }
 137                 tail = 0;
 138         }
 139         while (tail < head) {
 140                 oprofile_add_pc(buf->event_log[tail].eip,
 141                                 buf->event_log[tail].mode,
 142                                 buf->event_log[tail].event);
 143                 if (!is_passive)
 144                         oprofile_samples++;
 145                 else
 146                         p_oprofile_samples++;
 147                 tail++;
 148         }
 149
 150         buf->event_tail = tail;
 151 }
 152
 153 static void xenoprof_handle_passive(void)
 154 {
 155         int i, j;
 156         int flag_domain, flag_switch = 0;
 157
 158         for (i = 0; i < pdomains; i++) {
 159                 flag_domain = 0;
 160                 for (j = 0; j < passive_domains[i].nbuf; j++) {
 161                         xenoprof_buf_t *buf = p_xenoprof_buf[i][j];
 162                         if (buf->event_head == buf->event_tail)
 163                                 continue;
 164                         if (!flag_domain) {
 165                                 if (!oprofile_add_domain_switch(passive_domains[i].
 166                                                                 domain_id))
 167                                         goto done;
 168                                 flag_domain = 1;
 169                         }
 170                         xenoprof_add_pc(buf, 1);
 171                         flag_switch = 1;
 172                 }
 173         }
 174 done:
 175         if (flag_switch)
 176                 oprofile_add_domain_switch(COORDINATOR_DOMAIN);
 177 }
 178
 179 static irqreturn_t
 180 xenoprof_ovf_interrupt(int irq, void * dev_id)
 181 {
 182         struct xenoprof_buf * buf;
 183         int cpu;
 184         static unsigned long flag;
 185
 186         cpu = smp_processor_id();
 187         buf = xenoprof_buf[cpu];
 188
 189         xenoprof_add_pc(buf, 0);
 190
 191         if (xenoprof_is_primary && !test_and_set_bit(0, &flag)) {
 192                 xenoprof_handle_passive();
 193                 smp_mb__before_clear_bit();
 194                 clear_bit(0, &flag);
 195         }
 196
 197         return IRQ_HANDLED;
 198 }
 199
 200
 201 static void unbind_virq(void)
 202 {
 203         int i;
 204
 205         for_each_online_cpu(i) {
 206                 if (ovf_irq[i] >= 0) {
 207                         unbind_from_irqhandler(ovf_irq[i], NULL);
 208                         ovf_irq[i] = -1;
 209                 }
 210         }
 211 }
 212
 213
 214 static int bind_virq(void)
 215 {
 216         int i, result;
 217
 218         for_each_online_cpu(i) {
 219                 result = bind_virq_to_irqhandler(VIRQ_XENOPROF,
 220                                                  i,
 221                                                  xenoprof_ovf_interrupt,
 222                                                  SA_INTERRUPT,
 223                                                  "xenoprof",
 224                                                  NULL);
 225
 226                 if (result < 0) {
 227                         unbind_virq();
 228                         return result;
 229                 }
 230
 231                 ovf_irq[i] = result;
 232         }
 233
 234         return 0;
 235 }
 236
 237
 238 static void unmap_passive_list(void)
 239 {
 240         int i;
 241         for (i = 0; i < pdomains; i++)
 242                 xenoprof_arch_unmap_shared_buffer(&p_shared_buffer[i]);
 243         pdomains = 0;
 244 }
 245
 246
 247 static int map_xenoprof_buffer(int max_samples)
 248 {
 249         struct xenoprof_get_buffer get_buffer;
 250         struct xenoprof_buf *buf;
 251         int ret, i;
 252
 253         if ( shared_buffer.buffer )
 254                 return 0;
 255
 256         get_buffer.max_samples = max_samples;
 257         ret = xenoprof_arch_map_shared_buffer(&get_buffer, &shared_buffer);
 258         if (ret)
 259                 return ret;
 260         nbuf = get_buffer.nbuf;
 261
 262         for (i=0; i< nbuf; i++) {
 263                 buf = (struct xenoprof_buf*)
 264                         &shared_buffer.buffer[i * get_buffer.bufsize];
 265                 BUG_ON(buf->vcpu_id >= MAX_VIRT_CPUS);
 266                 xenoprof_buf[buf->vcpu_id] = buf;
 267         }
 268
 269         return 0;
 270 }
 271
 272
 273 static int xenoprof_setup(void)
 274 {
 275         int ret;
 276
 277         if ( (ret = map_xenoprof_buffer(MAX_XENOPROF_SAMPLES)) )
 278                 return ret;
 279
 280         if ( (ret = bind_virq()) )
 281                 return ret;
 282
 283         if (xenoprof_is_primary) {
 284                 /* Define dom0 as an active domain if not done yet */
 285                 if (!active_defined) {
 286                         domid_t domid;
 287                         ret = HYPERVISOR_xenoprof_op(XENOPROF_reset_active_list, NULL);
 288                         if (ret)
 289                                 goto err;
 290                         domid = 0;
 291                         ret = HYPERVISOR_xenoprof_op(XENOPROF_set_active, &domid);
 292                         if (ret)
 293                                 goto err;
 294                         active_defined = 1;
 295                 }
 296
 297                 ret = HYPERVISOR_xenoprof_op(XENOPROF_reserve_counters, NULL);
 298                 if (ret)
 299                         goto err;
 300                 xenoprof_arch_counter();
 301                 ret = HYPERVISOR_xenoprof_op(XENOPROF_setup_events, NULL);
 302
 303                 if (ret)
 304                         goto err;
 305         }
 306
 307         ret = HYPERVISOR_xenoprof_op(XENOPROF_enable_virq, NULL);
 308         if (ret)
 309                 goto err;
 310
 311         xenoprof_enabled = 1;
 312         return 0;
 313  err:
 314         unbind_virq();
 315         return ret;
 316 }
 317
 318
 319 static void xenoprof_shutdown(void)
 320 {
 321         xenoprof_enabled = 0;
 322
 323         HYPERVISOR_xenoprof_op(XENOPROF_disable_virq, NULL);
 324
 325         if (xenoprof_is_primary) {
 326                 HYPERVISOR_xenoprof_op(XENOPROF_release_counters, NULL);
 327                 active_defined = 0;
 328         }
 329
 330         unbind_virq();
 331
 332         xenoprof_arch_unmap_shared_buffer(&shared_buffer);
 333         if (xenoprof_is_primary)
 334                 unmap_passive_list();
 335 }
 336
 337
 338 static int xenoprof_start(void)
 339 {
 340         int ret = 0;
 341
 342         if (xenoprof_is_primary)
 343                 ret = HYPERVISOR_xenoprof_op(XENOPROF_start, NULL);
 344         if (!ret)
 345                 xenoprof_arch_start();
 346         return ret;
 347 }
 348
 349
 350 static void xenoprof_stop(void)
 351 {
 352         if (xenoprof_is_primary)
 353                 HYPERVISOR_xenoprof_op(XENOPROF_stop, NULL);
 354         xenoprof_arch_stop();
 355 }
 356
 357
 358 static int xenoprof_set_active(int * active_domains,
 359                                unsigned int adomains)
 360 {
 361         int ret = 0;
 362         int i;
 363         int set_dom0 = 0;
 364         domid_t domid;
 365
 366         if (!xenoprof_is_primary)
 367                 return 0;
 368
 369         if (adomains > MAX_OPROF_DOMAINS)
 370                 return -E2BIG;
 371
 372         ret = HYPERVISOR_xenoprof_op(XENOPROF_reset_active_list, NULL);
 373         if (ret)
 374                 return ret;
 375
 376         for (i=0; i<adomains; i++) {
 377                 domid = active_domains[i];
 378                 if (domid != active_domains[i]) {
 379                         ret = -EINVAL;
 380                         goto out;
 381                 }
 382                 ret = HYPERVISOR_xenoprof_op(XENOPROF_set_active, &domid);
 383                 if (ret)
 384                         goto out;
 385                 if (active_domains[i] == 0)
 386                         set_dom0 = 1;
 387         }
 388         /* dom0 must always be active but may not be in the list */
 389         if (!set_dom0) {
 390                 domid = 0;
 391                 ret = HYPERVISOR_xenoprof_op(XENOPROF_set_active, &domid);
 392         }
 393
 394 out:
 395         if (ret)
 396                 HYPERVISOR_xenoprof_op(XENOPROF_reset_active_list, NULL);
 397         active_defined = !ret;
 398         return ret;
 399 }
 400
 401 static int xenoprof_set_passive(int * p_domains,
 402                                 unsigned int pdoms)
 403 {
 404         int ret;
 405         int i, j;
 406         struct xenoprof_buf *buf;
 407
 408         if (!xenoprof_is_primary)
 409                 return 0;
 410
 411         if (pdoms > MAX_OPROF_DOMAINS)
 412                 return -E2BIG;
 413
 414         ret = HYPERVISOR_xenoprof_op(XENOPROF_reset_passive_list, NULL);
 415         if (ret)
 416                 return ret;
 417         unmap_passive_list();
 418
 419         for (i = 0; i < pdoms; i++) {
 420                 passive_domains[i].domain_id = p_domains[i];
 421                 passive_domains[i].max_samples = 2048;
 422                 ret = xenoprof_arch_set_passive(&passive_domains[i],
 423                                                 &p_shared_buffer[i]);
 424                 if (ret)
 425                         goto out;
 426                 for (j = 0; j < passive_domains[i].nbuf; j++) {
 427                         buf = (struct xenoprof_buf *)
 428                                 &p_shared_buffer[i].buffer[j * passive_domains[i].bufsize];
 429                         BUG_ON(buf->vcpu_id >= MAX_VIRT_CPUS);
 430                         p_xenoprof_buf[i][buf->vcpu_id] = buf;
 431                 }
 432         }
 433
 434         pdomains = pdoms;
 435         return 0;
 436
 437 out:
 438         for (j = 0; j < i; j++)
 439                 xenoprof_arch_unmap_shared_buffer(&p_shared_buffer[i]);
 440
 441         return ret;
 442 }
 443
 444 struct oprofile_operations xenoprof_ops = {
 445 #ifdef HAVE_XENOPROF_CREATE_FILES
 446         .create_files   = xenoprof_create_files,
 447 #endif
 448         .set_active     = xenoprof_set_active,
 449         .set_passive    = xenoprof_set_passive,
 450         .setup          = xenoprof_setup,
 451         .shutdown       = xenoprof_shutdown,
 452         .start          = xenoprof_start,
 453         .stop           = xenoprof_stop
 454 };
 455
 456
 457 /* in order to get driverfs right */
 458 static int using_xenoprof;
 459
 460 int __init xenoprofile_init(struct oprofile_operations * ops)
 461 {
 462         struct xenoprof_init init;
 463         int ret, i;
 464
 465         ret = HYPERVISOR_xenoprof_op(XENOPROF_init, &init);
 466         if (!ret) {
 467                 xenoprof_arch_init_counter(&init);
 468                 xenoprof_is_primary = init.is_primary;
 469
 470                 /*  cpu_type is detected by Xen */
 471                 cpu_type[XENOPROF_CPU_TYPE_SIZE-1] = 0;
 472                 strncpy(cpu_type, init.cpu_type, XENOPROF_CPU_TYPE_SIZE - 1);
 473                 xenoprof_ops.cpu_type = cpu_type;
 474
 475                 init_driverfs();
 476                 using_xenoprof = 1;
 477                 *ops = xenoprof_ops;
 478
 479                 for (i=0; i<NR_CPUS; i++)
 480                         ovf_irq[i] = -1;
 481
 482                 active_defined = 0;
 483         }
 484         printk(KERN_INFO "%s: ret %d, events %d, xenoprof_is_primary %d\n",
 485                __func__, ret, init.num_events, xenoprof_is_primary);
 486         return ret;
 487 }
 488
 489
 490 void xenoprofile_exit(void)
 491 {
 492         if (using_xenoprof)
 493                 exit_driverfs();
 494
 495         xenoprof_arch_unmap_shared_buffer(&shared_buffer);
 496         if (xenoprof_is_primary) {
 497                 unmap_passive_list();
 498                 HYPERVISOR_xenoprof_op(XENOPROF_shutdown, NULL);
 499         }
 500 }