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