1 /* local apic based NMI watchdog for various CPUs. 2 This file also handles reservation of performance counters for coordination 3 with other users (like oprofile). 4 5 Note that these events normally don't tick when the CPU idles. This means 6 the frequency varies with CPU load. 7 8 Original code for K7/P6 written by Keith Owens */ 9 10 #include <linux/percpu.h> 11 #include <linux/module.h> 12 #include <linux/kernel.h> 13 #include <linux/bitops.h> 14 #include <linux/smp.h> 15 #include <linux/nmi.h> 16 #include <asm/apic.h> 17 #include <asm/intel_arch_perfmon.h> 18 19 struct nmi_watchdog_ctlblk { 20 unsigned int cccr_msr; 21 unsigned int perfctr_msr; /* the MSR to reset in NMI handler */ 22 unsigned int evntsel_msr; /* the MSR to select the events to handle */ 23 }; 24 25 /* Interface defining a CPU specific perfctr watchdog */ 26 struct wd_ops { 27 int (*reserve)(void); 28 void (*unreserve)(void); 29 int (*setup)(unsigned nmi_hz); 30 void (*rearm)(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz); 31 void (*stop)(void); 32 unsigned perfctr; 33 unsigned evntsel; 34 u64 checkbit; 35 }; 36 37 static const struct wd_ops *wd_ops; 38 39 /* this number is calculated from Intel's MSR_P4_CRU_ESCR5 register and it's 40 * offset from MSR_P4_BSU_ESCR0. It will be the max for all platforms (for now) 41 */ 42 #define NMI_MAX_COUNTER_BITS 66 43 44 /* perfctr_nmi_owner tracks the ownership of the perfctr registers: 45 * evtsel_nmi_owner tracks the ownership of the event selection 46 * - different performance counters/ event selection may be reserved for 47 * different subsystems this reservation system just tries to coordinate 48 * things a little 49 */ 50 static DECLARE_BITMAP(perfctr_nmi_owner, NMI_MAX_COUNTER_BITS); 51 static DECLARE_BITMAP(evntsel_nmi_owner, NMI_MAX_COUNTER_BITS); 52 53 static DEFINE_PER_CPU(struct nmi_watchdog_ctlblk, nmi_watchdog_ctlblk); 54 55 /* converts an msr to an appropriate reservation bit */ 56 static inline unsigned int nmi_perfctr_msr_to_bit(unsigned int msr) 57 { 58 /* returns the bit offset of the performance counter register */ 59 switch (boot_cpu_data.x86_vendor) { 60 case X86_VENDOR_AMD: 61 return (msr - MSR_K7_PERFCTR0); 62 case X86_VENDOR_INTEL: 63 if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) 64 return (msr - MSR_ARCH_PERFMON_PERFCTR0); 65 66 switch (boot_cpu_data.x86) { 67 case 6: 68 return (msr - MSR_P6_PERFCTR0); 69 case 15: 70 return (msr - MSR_P4_BPU_PERFCTR0); 71 } 72 } 73 return 0; 74 } 75 76 /* converts an msr to an appropriate reservation bit */ 77 /* returns the bit offset of the event selection register */ 78 static inline unsigned int nmi_evntsel_msr_to_bit(unsigned int msr) 79 { 80 /* returns the bit offset of the event selection register */ 81 switch (boot_cpu_data.x86_vendor) { 82 case X86_VENDOR_AMD: 83 return (msr - MSR_K7_EVNTSEL0); 84 case X86_VENDOR_INTEL: 85 if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) 86 return (msr - MSR_ARCH_PERFMON_EVENTSEL0); 87 88 switch (boot_cpu_data.x86) { 89 case 6: 90 return (msr - MSR_P6_EVNTSEL0); 91 case 15: 92 return (msr - MSR_P4_BSU_ESCR0); 93 } 94 } 95 return 0; 96 97 } 98 99 /* checks for a bit availability (hack for oprofile) */ 100 int avail_to_resrv_perfctr_nmi_bit(unsigned int counter) 101 { 102 BUG_ON(counter > NMI_MAX_COUNTER_BITS); 103 104 return (!test_bit(counter, perfctr_nmi_owner)); 105 } 106 107 /* checks the an msr for availability */ 108 int avail_to_resrv_perfctr_nmi(unsigned int msr) 109 { 110 unsigned int counter; 111 112 counter = nmi_perfctr_msr_to_bit(msr); 113 BUG_ON(counter > NMI_MAX_COUNTER_BITS); 114 115 return (!test_bit(counter, perfctr_nmi_owner)); 116 } 117 118 int reserve_perfctr_nmi(unsigned int msr) 119 { 120 unsigned int counter; 121 122 counter = nmi_perfctr_msr_to_bit(msr); 123 BUG_ON(counter > NMI_MAX_COUNTER_BITS); 124 125 if (!test_and_set_bit(counter, perfctr_nmi_owner)) 126 return 1; 127 return 0; 128 } 129 130 void release_perfctr_nmi(unsigned int msr) 131 { 132 unsigned int counter; 133 134 counter = nmi_perfctr_msr_to_bit(msr); 135 BUG_ON(counter > NMI_MAX_COUNTER_BITS); 136 137 clear_bit(counter, perfctr_nmi_owner); 138 } 139 140 int reserve_evntsel_nmi(unsigned int msr) 141 { 142 unsigned int counter; 143 144 counter = nmi_evntsel_msr_to_bit(msr); 145 BUG_ON(counter > NMI_MAX_COUNTER_BITS); 146 147 if (!test_and_set_bit(counter, evntsel_nmi_owner)) 148 return 1; 149 return 0; 150 } 151 152 void release_evntsel_nmi(unsigned int msr) 153 { 154 unsigned int counter; 155 156 counter = nmi_evntsel_msr_to_bit(msr); 157 BUG_ON(counter > NMI_MAX_COUNTER_BITS); 158 159 clear_bit(counter, evntsel_nmi_owner); 160 } 161 162 EXPORT_SYMBOL(avail_to_resrv_perfctr_nmi); 163 EXPORT_SYMBOL(avail_to_resrv_perfctr_nmi_bit); 164 EXPORT_SYMBOL(reserve_perfctr_nmi); 165 EXPORT_SYMBOL(release_perfctr_nmi); 166 EXPORT_SYMBOL(reserve_evntsel_nmi); 167 EXPORT_SYMBOL(release_evntsel_nmi); 168 169 void disable_lapic_nmi_watchdog(void) 170 { 171 BUG_ON(nmi_watchdog != NMI_LOCAL_APIC); 172 173 if (atomic_read(&nmi_active) <= 0) 174 return; 175 176 on_each_cpu(stop_apic_nmi_watchdog, NULL, 0, 1); 177 wd_ops->unreserve(); 178 179 BUG_ON(atomic_read(&nmi_active) != 0); 180 } 181 182 void enable_lapic_nmi_watchdog(void) 183 { 184 BUG_ON(nmi_watchdog != NMI_LOCAL_APIC); 185 186 /* are we already enabled */ 187 if (atomic_read(&nmi_active) != 0) 188 return; 189 190 /* are we lapic aware */ 191 if (!wd_ops) 192 return; 193 if (!wd_ops->reserve()) { 194 printk(KERN_ERR "NMI watchdog: cannot reserve perfctrs\n"); 195 return; 196 } 197 198 on_each_cpu(setup_apic_nmi_watchdog, NULL, 0, 1); 199 touch_nmi_watchdog(); 200 } 201 202 /* 203 * Activate the NMI watchdog via the local APIC. 204 */ 205 206 static unsigned int adjust_for_32bit_ctr(unsigned int hz) 207 { 208 u64 counter_val; 209 unsigned int retval = hz; 210 211 /* 212 * On Intel CPUs with P6/ARCH_PERFMON only 32 bits in the counter 213 * are writable, with higher bits sign extending from bit 31. 214 * So, we can only program the counter with 31 bit values and 215 * 32nd bit should be 1, for 33.. to be 1. 216 * Find the appropriate nmi_hz 217 */ 218 counter_val = (u64)cpu_khz * 1000; 219 do_div(counter_val, retval); 220 if (counter_val > 0x7fffffffULL) { 221 u64 count = (u64)cpu_khz * 1000; 222 do_div(count, 0x7fffffffUL); 223 retval = count + 1; 224 } 225 return retval; 226 } 227 228 static void 229 write_watchdog_counter(unsigned int perfctr_msr, const char *descr, unsigned nmi_hz) 230 { 231 u64 count = (u64)cpu_khz * 1000; 232 233 do_div(count, nmi_hz); 234 if(descr) 235 Dprintk("setting %s to -0x%08Lx\n", descr, count); 236 wrmsrl(perfctr_msr, 0 - count); 237 } 238 239 static void write_watchdog_counter32(unsigned int perfctr_msr, 240 const char *descr, unsigned nmi_hz) 241 { 242 u64 count = (u64)cpu_khz * 1000; 243 244 do_div(count, nmi_hz); 245 if(descr) 246 Dprintk("setting %s to -0x%08Lx\n", descr, count); 247 wrmsr(perfctr_msr, (u32)(-count), 0); 248 } 249 250 /* AMD K7/K8/Family10h/Family11h support. AMD keeps this interface 251 nicely stable so there is not much variety */ 252 253 #define K7_EVNTSEL_ENABLE (1 << 22) 254 #define K7_EVNTSEL_INT (1 << 20) 255 #define K7_EVNTSEL_OS (1 << 17) 256 #define K7_EVNTSEL_USR (1 << 16) 257 #define K7_EVENT_CYCLES_PROCESSOR_IS_RUNNING 0x76 258 #define K7_NMI_EVENT K7_EVENT_CYCLES_PROCESSOR_IS_RUNNING 259 260 static int setup_k7_watchdog(unsigned nmi_hz) 261 { 262 unsigned int perfctr_msr, evntsel_msr; 263 unsigned int evntsel; 264 struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); 265 266 perfctr_msr = wd_ops->perfctr; 267 evntsel_msr = wd_ops->evntsel; 268 269 wrmsrl(perfctr_msr, 0UL); 270 271 evntsel = K7_EVNTSEL_INT 272 | K7_EVNTSEL_OS 273 | K7_EVNTSEL_USR 274 | K7_NMI_EVENT; 275 276 /* setup the timer */ 277 wrmsr(evntsel_msr, evntsel, 0); 278 write_watchdog_counter(perfctr_msr, "K7_PERFCTR0",nmi_hz); 279 apic_write(APIC_LVTPC, APIC_DM_NMI); 280 evntsel |= K7_EVNTSEL_ENABLE; 281 wrmsr(evntsel_msr, evntsel, 0); 282 283 wd->perfctr_msr = perfctr_msr; 284 wd->evntsel_msr = evntsel_msr; 285 wd->cccr_msr = 0; //unused 286 return 1; 287 } 288 289 static void single_msr_stop_watchdog(void) 290 { 291 struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); 292 293 wrmsr(wd->evntsel_msr, 0, 0); 294 } 295 296 static int single_msr_reserve(void) 297 { 298 if (!reserve_perfctr_nmi(wd_ops->perfctr)) 299 return 0; 300 301 if (!reserve_evntsel_nmi(wd_ops->evntsel)) { 302 release_perfctr_nmi(wd_ops->perfctr); 303 return 0; 304 } 305 return 1; 306 } 307 308 static void single_msr_unreserve(void) 309 { 310 release_evntsel_nmi(wd_ops->evntsel); 311 release_perfctr_nmi(wd_ops->perfctr); 312 } 313 314 static void single_msr_rearm(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz) 315 { 316 /* start the cycle over again */ 317 write_watchdog_counter(wd->perfctr_msr, NULL, nmi_hz); 318 } 319 320 static const struct wd_ops k7_wd_ops = { 321 .reserve = single_msr_reserve, 322 .unreserve = single_msr_unreserve, 323 .setup = setup_k7_watchdog, 324 .rearm = single_msr_rearm, 325 .stop = single_msr_stop_watchdog, 326 .perfctr = MSR_K7_PERFCTR0, 327 .evntsel = MSR_K7_EVNTSEL0, 328 .checkbit = 1ULL<<47, 329 }; 330 331 /* Intel Model 6 (PPro+,P2,P3,P-M,Core1) */ 332 333 #define P6_EVNTSEL0_ENABLE (1 << 22) 334 #define P6_EVNTSEL_INT (1 << 20) 335 #define P6_EVNTSEL_OS (1 << 17) 336 #define P6_EVNTSEL_USR (1 << 16) 337 #define P6_EVENT_CPU_CLOCKS_NOT_HALTED 0x79 338 #define P6_NMI_EVENT P6_EVENT_CPU_CLOCKS_NOT_HALTED 339 340 static int setup_p6_watchdog(unsigned nmi_hz) 341 { 342 unsigned int perfctr_msr, evntsel_msr; 343 unsigned int evntsel; 344 struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); 345 346 perfctr_msr = wd_ops->perfctr; 347 evntsel_msr = wd_ops->evntsel; 348 349 /* KVM doesn't implement this MSR */ 350 if (wrmsr_safe(perfctr_msr, 0, 0) < 0) 351 return 0; 352 353 evntsel = P6_EVNTSEL_INT 354 | P6_EVNTSEL_OS 355 | P6_EVNTSEL_USR 356 | P6_NMI_EVENT; 357 358 /* setup the timer */ 359 wrmsr(evntsel_msr, evntsel, 0); 360 nmi_hz = adjust_for_32bit_ctr(nmi_hz); 361 write_watchdog_counter32(perfctr_msr, "P6_PERFCTR0",nmi_hz); 362 apic_write(APIC_LVTPC, APIC_DM_NMI); 363 evntsel |= P6_EVNTSEL0_ENABLE; 364 wrmsr(evntsel_msr, evntsel, 0); 365 366 wd->perfctr_msr = perfctr_msr; 367 wd->evntsel_msr = evntsel_msr; 368 wd->cccr_msr = 0; //unused 369 return 1; 370 } 371 372 static void p6_rearm(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz) 373 { 374 /* P6 based Pentium M need to re-unmask 375 * the apic vector but it doesn't hurt 376 * other P6 variant. 377 * ArchPerfom/Core Duo also needs this */ 378 apic_write(APIC_LVTPC, APIC_DM_NMI); 379 /* P6/ARCH_PERFMON has 32 bit counter write */ 380 write_watchdog_counter32(wd->perfctr_msr, NULL,nmi_hz); 381 } 382 383 static const struct wd_ops p6_wd_ops = { 384 .reserve = single_msr_reserve, 385 .unreserve = single_msr_unreserve, 386 .setup = setup_p6_watchdog, 387 .rearm = p6_rearm, 388 .stop = single_msr_stop_watchdog, 389 .perfctr = MSR_P6_PERFCTR0, 390 .evntsel = MSR_P6_EVNTSEL0, 391 .checkbit = 1ULL<<39, 392 }; 393 394 /* Intel P4 performance counters. By far the most complicated of all. */ 395 396 #define MSR_P4_MISC_ENABLE_PERF_AVAIL (1<<7) 397 #define P4_ESCR_EVENT_SELECT(N) ((N)<<25) 398 #define P4_ESCR_OS (1<<3) 399 #define P4_ESCR_USR (1<<2) 400 #define P4_CCCR_OVF_PMI0 (1<<26) 401 #define P4_CCCR_OVF_PMI1 (1<<27) 402 #define P4_CCCR_THRESHOLD(N) ((N)<<20) 403 #define P4_CCCR_COMPLEMENT (1<<19) 404 #define P4_CCCR_COMPARE (1<<18) 405 #define P4_CCCR_REQUIRED (3<<16) 406 #define P4_CCCR_ESCR_SELECT(N) ((N)<<13) 407 #define P4_CCCR_ENABLE (1<<12) 408 #define P4_CCCR_OVF (1<<31) 409 410 /* Set up IQ_COUNTER0 to behave like a clock, by having IQ_CCCR0 filter 411 CRU_ESCR0 (with any non-null event selector) through a complemented 412 max threshold. [IA32-Vol3, Section 14.9.9] */ 413 414 static int setup_p4_watchdog(unsigned nmi_hz) 415 { 416 unsigned int perfctr_msr, evntsel_msr, cccr_msr; 417 unsigned int evntsel, cccr_val; 418 unsigned int misc_enable, dummy; 419 unsigned int ht_num; 420 struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); 421 422 rdmsr(MSR_IA32_MISC_ENABLE, misc_enable, dummy); 423 if (!(misc_enable & MSR_P4_MISC_ENABLE_PERF_AVAIL)) 424 return 0; 425 426 #ifdef CONFIG_SMP 427 /* detect which hyperthread we are on */ 428 if (smp_num_siblings == 2) { 429 unsigned int ebx, apicid; 430 431 ebx = cpuid_ebx(1); 432 apicid = (ebx >> 24) & 0xff; 433 ht_num = apicid & 1; 434 } else 435 #endif 436 ht_num = 0; 437 438 /* performance counters are shared resources 439 * assign each hyperthread its own set 440 * (re-use the ESCR0 register, seems safe 441 * and keeps the cccr_val the same) 442 */ 443 if (!ht_num) { 444 /* logical cpu 0 */ 445 perfctr_msr = MSR_P4_IQ_PERFCTR0; 446 evntsel_msr = MSR_P4_CRU_ESCR0; 447 cccr_msr = MSR_P4_IQ_CCCR0; 448 cccr_val = P4_CCCR_OVF_PMI0 | P4_CCCR_ESCR_SELECT(4); 449 } else { 450 /* logical cpu 1 */ 451 perfctr_msr = MSR_P4_IQ_PERFCTR1; 452 evntsel_msr = MSR_P4_CRU_ESCR0; 453 cccr_msr = MSR_P4_IQ_CCCR1; 454 cccr_val = P4_CCCR_OVF_PMI1 | P4_CCCR_ESCR_SELECT(4); 455 } 456 457 evntsel = P4_ESCR_EVENT_SELECT(0x3F) 458 | P4_ESCR_OS 459 | P4_ESCR_USR; 460 461 cccr_val |= P4_CCCR_THRESHOLD(15) 462 | P4_CCCR_COMPLEMENT 463 | P4_CCCR_COMPARE 464 | P4_CCCR_REQUIRED; 465 466 wrmsr(evntsel_msr, evntsel, 0); 467 wrmsr(cccr_msr, cccr_val, 0); 468 write_watchdog_counter(perfctr_msr, "P4_IQ_COUNTER0", nmi_hz); 469 apic_write(APIC_LVTPC, APIC_DM_NMI); 470 cccr_val |= P4_CCCR_ENABLE; 471 wrmsr(cccr_msr, cccr_val, 0); 472 wd->perfctr_msr = perfctr_msr; 473 wd->evntsel_msr = evntsel_msr; 474 wd->cccr_msr = cccr_msr; 475 return 1; 476 } 477 478 static void stop_p4_watchdog(void) 479 { 480 struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); 481 wrmsr(wd->cccr_msr, 0, 0); 482 wrmsr(wd->evntsel_msr, 0, 0); 483 } 484 485 static int p4_reserve(void) 486 { 487 if (!reserve_perfctr_nmi(MSR_P4_IQ_PERFCTR0)) 488 return 0; 489 #ifdef CONFIG_SMP 490 if (smp_num_siblings > 1 && !reserve_perfctr_nmi(MSR_P4_IQ_PERFCTR1)) 491 goto fail1; 492 #endif 493 if (!reserve_evntsel_nmi(MSR_P4_CRU_ESCR0)) 494 goto fail2; 495 /* RED-PEN why is ESCR1 not reserved here? */ 496 return 1; 497 fail2: 498 #ifdef CONFIG_SMP 499 if (smp_num_siblings > 1) 500 release_perfctr_nmi(MSR_P4_IQ_PERFCTR1); 501 fail1: 502 #endif 503 release_perfctr_nmi(MSR_P4_IQ_PERFCTR0); 504 return 0; 505 } 506 507 static void p4_unreserve(void) 508 { 509 #ifdef CONFIG_SMP 510 if (smp_num_siblings > 1) 511 release_perfctr_nmi(MSR_P4_IQ_PERFCTR1); 512 #endif 513 release_evntsel_nmi(MSR_P4_CRU_ESCR0); 514 release_perfctr_nmi(MSR_P4_IQ_PERFCTR0); 515 } 516 517 static void p4_rearm(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz) 518 { 519 unsigned dummy; 520 /* 521 * P4 quirks: 522 * - An overflown perfctr will assert its interrupt 523 * until the OVF flag in its CCCR is cleared. 524 * - LVTPC is masked on interrupt and must be 525 * unmasked by the LVTPC handler. 526 */ 527 rdmsrl(wd->cccr_msr, dummy); 528 dummy &= ~P4_CCCR_OVF; 529 wrmsrl(wd->cccr_msr, dummy); 530 apic_write(APIC_LVTPC, APIC_DM_NMI); 531 /* start the cycle over again */ 532 write_watchdog_counter(wd->perfctr_msr, NULL, nmi_hz); 533 } 534 535 static const struct wd_ops p4_wd_ops = { 536 .reserve = p4_reserve, 537 .unreserve = p4_unreserve, 538 .setup = setup_p4_watchdog, 539 .rearm = p4_rearm, 540 .stop = stop_p4_watchdog, 541 /* RED-PEN this is wrong for the other sibling */ 542 .perfctr = MSR_P4_BPU_PERFCTR0, 543 .evntsel = MSR_P4_BSU_ESCR0, 544 .checkbit = 1ULL<<39, 545 }; 546 547 /* Watchdog using the Intel architected PerfMon. Used for Core2 and hopefully 548 all future Intel CPUs. */ 549 550 #define ARCH_PERFMON_NMI_EVENT_SEL ARCH_PERFMON_UNHALTED_CORE_CYCLES_SEL 551 #define ARCH_PERFMON_NMI_EVENT_UMASK ARCH_PERFMON_UNHALTED_CORE_CYCLES_UMASK 552 553 static struct wd_ops intel_arch_wd_ops; 554 555 static int setup_intel_arch_watchdog(unsigned nmi_hz) 556 { 557 unsigned int ebx; 558 union cpuid10_eax eax; 559 unsigned int unused; 560 unsigned int perfctr_msr, evntsel_msr; 561 unsigned int evntsel; 562 struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); 563 564 /* 565 * Check whether the Architectural PerfMon supports 566 * Unhalted Core Cycles Event or not. 567 * NOTE: Corresponding bit = 0 in ebx indicates event present. 568 */ 569 cpuid(10, &(eax.full), &ebx, &unused, &unused); 570 if ((eax.split.mask_length < (ARCH_PERFMON_UNHALTED_CORE_CYCLES_INDEX+1)) || 571 (ebx & ARCH_PERFMON_UNHALTED_CORE_CYCLES_PRESENT)) 572 return 0; 573 574 perfctr_msr = wd_ops->perfctr; 575 evntsel_msr = wd_ops->evntsel; 576 577 wrmsrl(perfctr_msr, 0UL); 578 579 evntsel = ARCH_PERFMON_EVENTSEL_INT 580 | ARCH_PERFMON_EVENTSEL_OS 581 | ARCH_PERFMON_EVENTSEL_USR 582 | ARCH_PERFMON_NMI_EVENT_SEL 583 | ARCH_PERFMON_NMI_EVENT_UMASK; 584 585 /* setup the timer */ 586 wrmsr(evntsel_msr, evntsel, 0); 587 nmi_hz = adjust_for_32bit_ctr(nmi_hz); 588 write_watchdog_counter32(perfctr_msr, "INTEL_ARCH_PERFCTR0", nmi_hz); 589 apic_write(APIC_LVTPC, APIC_DM_NMI); 590 evntsel |= ARCH_PERFMON_EVENTSEL0_ENABLE; 591 wrmsr(evntsel_msr, evntsel, 0); 592 593 wd->perfctr_msr = perfctr_msr; 594 wd->evntsel_msr = evntsel_msr; 595 wd->cccr_msr = 0; //unused 596 intel_arch_wd_ops.checkbit = 1ULL << (eax.split.bit_width - 1); 597 return 1; 598 } 599 600 static struct wd_ops intel_arch_wd_ops __read_mostly = { 601 .reserve = single_msr_reserve, 602 .unreserve = single_msr_unreserve, 603 .setup = setup_intel_arch_watchdog, 604 .rearm = p6_rearm, 605 .stop = single_msr_stop_watchdog, 606 .perfctr = MSR_ARCH_PERFMON_PERFCTR1, 607 .evntsel = MSR_ARCH_PERFMON_EVENTSEL1, 608 }; 609 610 static struct wd_ops coreduo_wd_ops = { 611 .reserve = single_msr_reserve, 612 .unreserve = single_msr_unreserve, 613 .setup = setup_intel_arch_watchdog, 614 .rearm = p6_rearm, 615 .stop = single_msr_stop_watchdog, 616 .perfctr = MSR_ARCH_PERFMON_PERFCTR0, 617 .evntsel = MSR_ARCH_PERFMON_EVENTSEL0, 618 }; 619 620 static void probe_nmi_watchdog(void) 621 { 622 switch (boot_cpu_data.x86_vendor) { 623 case X86_VENDOR_AMD: 624 if (boot_cpu_data.x86 != 6 && boot_cpu_data.x86 != 15 && 625 boot_cpu_data.x86 != 16) 626 return; 627 wd_ops = &k7_wd_ops; 628 break; 629 case X86_VENDOR_INTEL: 630 /* Work around Core Duo (Yonah) errata AE49 where perfctr1 631 doesn't have a working enable bit. */ 632 if (boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model == 14) { 633 wd_ops = &coreduo_wd_ops; 634 break; 635 } 636 if (cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) { 637 wd_ops = &intel_arch_wd_ops; 638 break; 639 } 640 switch (boot_cpu_data.x86) { 641 case 6: 642 if (boot_cpu_data.x86_model > 0xd) 643 return; 644 645 wd_ops = &p6_wd_ops; 646 break; 647 case 15: 648 if (boot_cpu_data.x86_model > 0x4) 649 return; 650 651 wd_ops = &p4_wd_ops; 652 break; 653 default: 654 return; 655 } 656 break; 657 } 658 } 659 660 /* Interface to nmi.c */ 661 662 int lapic_watchdog_init(unsigned nmi_hz) 663 { 664 if (!wd_ops) { 665 probe_nmi_watchdog(); 666 if (!wd_ops) 667 return -1; 668 669 if (!wd_ops->reserve()) { 670 printk(KERN_ERR 671 "NMI watchdog: cannot reserve perfctrs\n"); 672 return -1; 673 } 674 } 675 676 if (!(wd_ops->setup(nmi_hz))) { 677 printk(KERN_ERR "Cannot setup NMI watchdog on CPU %d\n", 678 raw_smp_processor_id()); 679 return -1; 680 } 681 682 return 0; 683 } 684 685 void lapic_watchdog_stop(void) 686 { 687 if (wd_ops) 688 wd_ops->stop(); 689 } 690 691 unsigned lapic_adjust_nmi_hz(unsigned hz) 692 { 693 struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); 694 if (wd->perfctr_msr == MSR_P6_PERFCTR0 || 695 wd->perfctr_msr == MSR_ARCH_PERFMON_PERFCTR1) 696 hz = adjust_for_32bit_ctr(hz); 697 return hz; 698 } 699 700 int lapic_wd_event(unsigned nmi_hz) 701 { 702 struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk); 703 u64 ctr; 704 rdmsrl(wd->perfctr_msr, ctr); 705 if (ctr & wd_ops->checkbit) { /* perfctr still running? */ 706 return 0; 707 } 708 wd_ops->rearm(wd, nmi_hz); 709 return 1; 710 } 711 712 int lapic_watchdog_ok(void) 713 { 714 return wd_ops != NULL; 715 } 716