arch/x86/oprofile/nmi_int.c

   1 /**
   2  * @file nmi_int.c
   3  *
   4  * @remark Copyright 2002 OProfile authors
   5  * @remark Read the file COPYING
   6  *
   7  * @author John Levon <levon@movementarian.org>
   8  */
   9
  10 #include <linux/init.h>
  11 #include <linux/notifier.h>
  12 #include <linux/smp.h>
  13 #include <linux/oprofile.h>
  14 #include <linux/sysdev.h>
  15 #include <linux/slab.h>
  16 #include <linux/moduleparam.h>
  17 #include <linux/kdebug.h>
  18 #include <asm/nmi.h>
  19 #include <asm/msr.h>
  20 #include <asm/apic.h>
  21
  22 #include "op_counter.h"
  23 #include "op_x86_model.h"
  24
  25 static struct op_x86_model_spec const * model;
  26 static struct op_msrs cpu_msrs[NR_CPUS];
  27 static unsigned long saved_lvtpc[NR_CPUS];
  28
  29 static int nmi_start(void);
  30 static void nmi_stop(void);
  31
  32 /* 0 == registered but off, 1 == registered and on */
  33 static int nmi_enabled = 0;
  34
  35 #ifdef CONFIG_PM
  36
  37 static int nmi_suspend(struct sys_device *dev, pm_message_t state)
  38 {
  39         if (nmi_enabled == 1)
  40                 nmi_stop();
  41         return 0;
  42 }
  43
  44
  45 static int nmi_resume(struct sys_device *dev)
  46 {
  47         if (nmi_enabled == 1)
  48                 nmi_start();
  49         return 0;
  50 }
  51
  52
  53 static struct sysdev_class oprofile_sysclass = {
  54         set_kset_name("oprofile"),
  55         .resume         = nmi_resume,
  56         .suspend        = nmi_suspend,
  57 };
  58
  59
  60 static struct sys_device device_oprofile = {
  61         .id     = 0,
  62         .cls    = &oprofile_sysclass,
  63 };
  64
  65
  66 static int __init init_sysfs(void)
  67 {
  68         int error;
  69         if (!(error = sysdev_class_register(&oprofile_sysclass)))
  70                 error = sysdev_register(&device_oprofile);
  71         return error;
  72 }
  73
  74
  75 static void exit_sysfs(void)
  76 {
  77         sysdev_unregister(&device_oprofile);
  78         sysdev_class_unregister(&oprofile_sysclass);
  79 }
  80
  81 #else
  82 #define init_sysfs() do { } while (0)
  83 #define exit_sysfs() do { } while (0)
  84 #endif /* CONFIG_PM */
  85
  86 static int profile_exceptions_notify(struct notifier_block *self,
  87                                      unsigned long val, void *data)
  88 {
  89         struct die_args *args = (struct die_args *)data;
  90         int ret = NOTIFY_DONE;
  91         int cpu = smp_processor_id();
  92
  93         switch(val) {
  94         case DIE_NMI:
  95                 if (model->check_ctrs(args->regs, &cpu_msrs[cpu]))
  96                         ret = NOTIFY_STOP;
  97                 break;
  98         default:
  99                 break;
 100         }
 101         return ret;
 102 }
 103
 104 static void nmi_cpu_save_registers(struct op_msrs * msrs)
 105 {
 106         unsigned int const nr_ctrs = model->num_counters;
 107         unsigned int const nr_ctrls = model->num_controls;
 108         struct op_msr * counters = msrs->counters;
 109         struct op_msr * controls = msrs->controls;
 110         unsigned int i;
 111
 112         for (i = 0; i < nr_ctrs; ++i) {
 113                 if (counters[i].addr){
 114                         rdmsr(counters[i].addr,
 115                                 counters[i].saved.low,
 116                                 counters[i].saved.high);
 117                 }
 118         }
 119
 120         for (i = 0; i < nr_ctrls; ++i) {
 121                 if (controls[i].addr){
 122                         rdmsr(controls[i].addr,
 123                                 controls[i].saved.low,
 124                                 controls[i].saved.high);
 125                 }
 126         }
 127 }
 128
 129
 130 static void nmi_save_registers(void * dummy)
 131 {
 132         int cpu = smp_processor_id();
 133         struct op_msrs * msrs = &cpu_msrs[cpu];
 134         nmi_cpu_save_registers(msrs);
 135 }
 136
 137
 138 static void free_msrs(void)
 139 {
 140         int i;
 141         for_each_possible_cpu(i) {
 142                 kfree(cpu_msrs[i].counters);
 143                 cpu_msrs[i].counters = NULL;
 144                 kfree(cpu_msrs[i].controls);
 145                 cpu_msrs[i].controls = NULL;
 146         }
 147 }
 148
 149
 150 static int allocate_msrs(void)
 151 {
 152         int success = 1;
 153         size_t controls_size = sizeof(struct op_msr) * model->num_controls;
 154         size_t counters_size = sizeof(struct op_msr) * model->num_counters;
 155
 156         int i;
 157         for_each_possible_cpu(i) {
 158                 cpu_msrs[i].counters = kmalloc(counters_size, GFP_KERNEL);
 159                 if (!cpu_msrs[i].counters) {
 160                         success = 0;
 161                         break;
 162                 }
 163                 cpu_msrs[i].controls = kmalloc(controls_size, GFP_KERNEL);
 164                 if (!cpu_msrs[i].controls) {
 165                         success = 0;
 166                         break;
 167                 }
 168         }
 169
 170         if (!success)
 171                 free_msrs();
 172
 173         return success;
 174 }
 175
 176
 177 static void nmi_cpu_setup(void * dummy)
 178 {
 179         int cpu = smp_processor_id();
 180         struct op_msrs * msrs = &cpu_msrs[cpu];
 181         spin_lock(&oprofilefs_lock);
 182         model->setup_ctrs(msrs);
 183         spin_unlock(&oprofilefs_lock);
 184         saved_lvtpc[cpu] = apic_read(APIC_LVTPC);
 185         apic_write(APIC_LVTPC, APIC_DM_NMI);
 186 }
 187
 188 static struct notifier_block profile_exceptions_nb = {
 189         .notifier_call = profile_exceptions_notify,
 190         .next = NULL,
 191         .priority = 0
 192 };
 193
 194 static int nmi_setup(void)
 195 {
 196         int err=0;
 197         int cpu;
 198
 199         if (!allocate_msrs())
 200                 return -ENOMEM;
 201
 202         if ((err = register_die_notifier(&profile_exceptions_nb))){
 203                 free_msrs();
 204                 return err;
 205         }
 206
 207         /* We need to serialize save and setup for HT because the subset
 208          * of msrs are distinct for save and setup operations
 209          */
 210
 211         /* Assume saved/restored counters are the same on all CPUs */
 212         model->fill_in_addresses(&cpu_msrs[0]);
 213         for_each_possible_cpu (cpu) {
 214                 if (cpu != 0) {
 215                         memcpy(cpu_msrs[cpu].counters, cpu_msrs[0].counters,
 216                                 sizeof(struct op_msr) * model->num_counters);
 217
 218                         memcpy(cpu_msrs[cpu].controls, cpu_msrs[0].controls,
 219                                 sizeof(struct op_msr) * model->num_controls);
 220                 }
 221
 222         }
 223         on_each_cpu(nmi_save_registers, NULL, 0, 1);
 224         on_each_cpu(nmi_cpu_setup, NULL, 0, 1);
 225         nmi_enabled = 1;
 226         return 0;
 227 }
 228
 229
 230 static void nmi_restore_registers(struct op_msrs * msrs)
 231 {
 232         unsigned int const nr_ctrs = model->num_counters;
 233         unsigned int const nr_ctrls = model->num_controls;
 234         struct op_msr * counters = msrs->counters;
 235         struct op_msr * controls = msrs->controls;
 236         unsigned int i;
 237
 238         for (i = 0; i < nr_ctrls; ++i) {
 239                 if (controls[i].addr){
 240                         wrmsr(controls[i].addr,
 241                                 controls[i].saved.low,
 242                                 controls[i].saved.high);
 243                 }
 244         }
 245
 246         for (i = 0; i < nr_ctrs; ++i) {
 247                 if (counters[i].addr){
 248                         wrmsr(counters[i].addr,
 249                                 counters[i].saved.low,
 250                                 counters[i].saved.high);
 251                 }
 252         }
 253 }
 254
 255
 256 static void nmi_cpu_shutdown(void * dummy)
 257 {
 258         unsigned int v;
 259         int cpu = smp_processor_id();
 260         struct op_msrs * msrs = &cpu_msrs[cpu];
 261
 262         /* restoring APIC_LVTPC can trigger an apic error because the delivery
 263          * mode and vector nr combination can be illegal. That's by design: on
 264          * power on apic lvt contain a zero vector nr which are legal only for
 265          * NMI delivery mode. So inhibit apic err before restoring lvtpc
 266          */
 267         v = apic_read(APIC_LVTERR);
 268         apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
 269         apic_write(APIC_LVTPC, saved_lvtpc[cpu]);
 270         apic_write(APIC_LVTERR, v);
 271         nmi_restore_registers(msrs);
 272 }
 273
 274
 275 static void nmi_shutdown(void)
 276 {
 277         nmi_enabled = 0;
 278         on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1);
 279         unregister_die_notifier(&profile_exceptions_nb);
 280         model->shutdown(cpu_msrs);
 281         free_msrs();
 282 }
 283
 284
 285 static void nmi_cpu_start(void * dummy)
 286 {
 287         struct op_msrs const * msrs = &cpu_msrs[smp_processor_id()];
 288         model->start(msrs);
 289 }
 290
 291
 292 static int nmi_start(void)
 293 {
 294         on_each_cpu(nmi_cpu_start, NULL, 0, 1);
 295         return 0;
 296 }
 297
 298
 299 static void nmi_cpu_stop(void * dummy)
 300 {
 301         struct op_msrs const * msrs = &cpu_msrs[smp_processor_id()];
 302         model->stop(msrs);
 303 }
 304
 305
 306 static void nmi_stop(void)
 307 {
 308         on_each_cpu(nmi_cpu_stop, NULL, 0, 1);
 309 }
 310
 311
 312 struct op_counter_config counter_config[OP_MAX_COUNTER];
 313
 314 static int nmi_create_files(struct super_block * sb, struct dentry * root)
 315 {
 316         unsigned int i;
 317
 318         for (i = 0; i < model->num_counters; ++i) {
 319                 struct dentry * dir;
 320                 char buf[4];
 321
 322                 /* quick little hack to _not_ expose a counter if it is not
 323                  * available for use.  This should protect userspace app.
 324                  * NOTE:  assumes 1:1 mapping here (that counters are organized
 325                  *        sequentially in their struct assignment).
 326                  */
 327                 if (unlikely(!avail_to_resrv_perfctr_nmi_bit(i)))
 328                         continue;
 329
 330                 snprintf(buf,  sizeof(buf), "%d", i);
 331                 dir = oprofilefs_mkdir(sb, root, buf);
 332                 oprofilefs_create_ulong(sb, dir, "enabled", &counter_config[i].enabled);
 333                 oprofilefs_create_ulong(sb, dir, "event", &counter_config[i].event);
 334                 oprofilefs_create_ulong(sb, dir, "count", &counter_config[i].count);
 335                 oprofilefs_create_ulong(sb, dir, "unit_mask", &counter_config[i].unit_mask);
 336                 oprofilefs_create_ulong(sb, dir, "kernel", &counter_config[i].kernel);
 337                 oprofilefs_create_ulong(sb, dir, "user", &counter_config[i].user);
 338         }
 339
 340         return 0;
 341 }
 342
 343 static int p4force;
 344 module_param(p4force, int, 0);
 345
 346 static int __init p4_init(char ** cpu_type)
 347 {
 348         __u8 cpu_model = boot_cpu_data.x86_model;
 349
 350         if (!p4force && (cpu_model > 6 || cpu_model == 5))
 351                 return 0;
 352
 353 #ifndef CONFIG_SMP
 354         *cpu_type = "i386/p4";
 355         model = &op_p4_spec;
 356         return 1;
 357 #else
 358         switch (smp_num_siblings) {
 359                 case 1:
 360                         *cpu_type = "i386/p4";
 361                         model = &op_p4_spec;
 362                         return 1;
 363
 364                 case 2:
 365                         *cpu_type = "i386/p4-ht";
 366                         model = &op_p4_ht2_spec;
 367                         return 1;
 368         }
 369 #endif
 370
 371         printk(KERN_INFO "oprofile: P4 HyperThreading detected with > 2 threads\n");
 372         printk(KERN_INFO "oprofile: Reverting to timer mode.\n");
 373         return 0;
 374 }
 375
 376
 377 static int __init ppro_init(char ** cpu_type)
 378 {
 379         __u8 cpu_model = boot_cpu_data.x86_model;
 380
 381         if (cpu_model == 14)
 382                 *cpu_type = "i386/core";
 383         else if (cpu_model == 15)
 384                 *cpu_type = "i386/core_2";
 385         else if (cpu_model > 0xd)
 386                 return 0;
 387         else if (cpu_model == 9) {
 388                 *cpu_type = "i386/p6_mobile";
 389         } else if (cpu_model > 5) {
 390                 *cpu_type = "i386/piii";
 391         } else if (cpu_model > 2) {
 392                 *cpu_type = "i386/pii";
 393         } else {
 394                 *cpu_type = "i386/ppro";
 395         }
 396
 397         model = &op_ppro_spec;
 398         return 1;
 399 }
 400
 401 /* in order to get sysfs right */
 402 static int using_nmi;
 403
 404 int __init op_nmi_init(struct oprofile_operations *ops)
 405 {
 406         __u8 vendor = boot_cpu_data.x86_vendor;
 407         __u8 family = boot_cpu_data.x86;
 408         char *cpu_type;
 409
 410         if (!cpu_has_apic)
 411                 return -ENODEV;
 412
 413         switch (vendor) {
 414                 case X86_VENDOR_AMD:
 415                         /* Needs to be at least an Athlon (or hammer in 32bit mode) */
 416
 417                         switch (family) {
 418                         default:
 419                                 return -ENODEV;
 420                         case 6:
 421                                 model = &op_athlon_spec;
 422                                 cpu_type = "i386/athlon";
 423                                 break;
 424                         case 0xf:
 425                                 model = &op_athlon_spec;
 426                                 /* Actually it could be i386/hammer too, but give
 427                                    user space an consistent name. */
 428                                 cpu_type = "x86-64/hammer";
 429                                 break;
 430                         case 0x10:
 431                                 model = &op_athlon_spec;
 432                                 cpu_type = "x86-64/family10";
 433                                 break;
 434                         }
 435                         break;
 436
 437                 case X86_VENDOR_INTEL:
 438                         switch (family) {
 439                                 /* Pentium IV */
 440                                 case 0xf:
 441                                         if (!p4_init(&cpu_type))
 442                                                 return -ENODEV;
 443                                         break;
 444
 445                                 /* A P6-class processor */
 446                                 case 6:
 447                                         if (!ppro_init(&cpu_type))
 448                                                 return -ENODEV;
 449                                         break;
 450
 451                                 default:
 452                                         return -ENODEV;
 453                         }
 454                         break;
 455
 456                 default:
 457                         return -ENODEV;
 458         }
 459
 460         init_sysfs();
 461         using_nmi = 1;
 462         ops->create_files = nmi_create_files;
 463         ops->setup = nmi_setup;
 464         ops->shutdown = nmi_shutdown;
 465         ops->start = nmi_start;
 466         ops->stop = nmi_stop;
 467         ops->cpu_type = cpu_type;
 468         printk(KERN_INFO "oprofile: using NMI interrupt.\n");
 469         return 0;
 470 }
 471
 472
 473 void op_nmi_exit(void)
 474 {
 475         if (using_nmi)
 476                 exit_sysfs();
 477 }