1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * x86 SMP booting functions 4 * 5 * (c) 1995 Alan Cox, Building #3 <alan@lxorguk.ukuu.org.uk> 6 * (c) 1998, 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com> 7 * Copyright 2001 Andi Kleen, SuSE Labs. 8 * 9 * Much of the core SMP work is based on previous work by Thomas Radke, to 10 * whom a great many thanks are extended. 11 * 12 * Thanks to Intel for making available several different Pentium, 13 * Pentium Pro and Pentium-II/Xeon MP machines. 14 * Original development of Linux SMP code supported by Caldera. 15 * 16 * Fixes 17 * Felix Koop : NR_CPUS used properly 18 * Jose Renau : Handle single CPU case. 19 * Alan Cox : By repeated request 8) - Total BogoMIPS report. 20 * Greg Wright : Fix for kernel stacks panic. 21 * Erich Boleyn : MP v1.4 and additional changes. 22 * Matthias Sattler : Changes for 2.1 kernel map. 23 * Michel Lespinasse : Changes for 2.1 kernel map. 24 * Michael Chastain : Change trampoline.S to gnu as. 25 * Alan Cox : Dumb bug: 'B' step PPro's are fine 26 * Ingo Molnar : Added APIC timers, based on code 27 * from Jose Renau 28 * Ingo Molnar : various cleanups and rewrites 29 * Tigran Aivazian : fixed "0.00 in /proc/uptime on SMP" bug. 30 * Maciej W. Rozycki : Bits for genuine 82489DX APICs 31 * Andi Kleen : Changed for SMP boot into long mode. 32 * Martin J. Bligh : Added support for multi-quad systems 33 * Dave Jones : Report invalid combinations of Athlon CPUs. 34 * Rusty Russell : Hacked into shape for new "hotplug" boot process. 35 * Andi Kleen : Converted to new state machine. 36 * Ashok Raj : CPU hotplug support 37 * Glauber Costa : i386 and x86_64 integration 38 */ 39 40 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 41 42 #include <linux/init.h> 43 #include <linux/smp.h> 44 #include <linux/export.h> 45 #include <linux/sched.h> 46 #include <linux/sched/topology.h> 47 #include <linux/sched/hotplug.h> 48 #include <linux/sched/task_stack.h> 49 #include <linux/percpu.h> 50 #include <linux/memblock.h> 51 #include <linux/err.h> 52 #include <linux/nmi.h> 53 #include <linux/tboot.h> 54 #include <linux/gfp.h> 55 #include <linux/cpuidle.h> 56 #include <linux/numa.h> 57 #include <linux/pgtable.h> 58 #include <linux/overflow.h> 59 60 #include <asm/acpi.h> 61 #include <asm/desc.h> 62 #include <asm/nmi.h> 63 #include <asm/irq.h> 64 #include <asm/realmode.h> 65 #include <asm/cpu.h> 66 #include <asm/numa.h> 67 #include <asm/tlbflush.h> 68 #include <asm/mtrr.h> 69 #include <asm/mwait.h> 70 #include <asm/apic.h> 71 #include <asm/io_apic.h> 72 #include <asm/fpu/internal.h> 73 #include <asm/setup.h> 74 #include <asm/uv/uv.h> 75 #include <linux/mc146818rtc.h> 76 #include <asm/i8259.h> 77 #include <asm/misc.h> 78 #include <asm/qspinlock.h> 79 #include <asm/intel-family.h> 80 #include <asm/cpu_device_id.h> 81 #include <asm/spec-ctrl.h> 82 #include <asm/hw_irq.h> 83 #include <asm/stackprotector.h> 84 85 /* representing HT siblings of each logical CPU */ 86 DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map); 87 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map); 88 89 /* representing HT and core siblings of each logical CPU */ 90 DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_map); 91 EXPORT_PER_CPU_SYMBOL(cpu_core_map); 92 93 /* representing HT, core, and die siblings of each logical CPU */ 94 DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_die_map); 95 EXPORT_PER_CPU_SYMBOL(cpu_die_map); 96 97 DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_llc_shared_map); 98 99 /* Per CPU bogomips and other parameters */ 100 DEFINE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info); 101 EXPORT_PER_CPU_SYMBOL(cpu_info); 102 103 /* Logical package management. We might want to allocate that dynamically */ 104 unsigned int __max_logical_packages __read_mostly; 105 EXPORT_SYMBOL(__max_logical_packages); 106 static unsigned int logical_packages __read_mostly; 107 static unsigned int logical_die __read_mostly; 108 109 /* Maximum number of SMT threads on any online core */ 110 int __read_mostly __max_smt_threads = 1; 111 112 /* Flag to indicate if a complete sched domain rebuild is required */ 113 bool x86_topology_update; 114 115 int arch_update_cpu_topology(void) 116 { 117 int retval = x86_topology_update; 118 119 x86_topology_update = false; 120 return retval; 121 } 122 123 static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip) 124 { 125 unsigned long flags; 126 127 spin_lock_irqsave(&rtc_lock, flags); 128 CMOS_WRITE(0xa, 0xf); 129 spin_unlock_irqrestore(&rtc_lock, flags); 130 *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_HIGH)) = 131 start_eip >> 4; 132 *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = 133 start_eip & 0xf; 134 } 135 136 static inline void smpboot_restore_warm_reset_vector(void) 137 { 138 unsigned long flags; 139 140 /* 141 * Paranoid: Set warm reset code and vector here back 142 * to default values. 143 */ 144 spin_lock_irqsave(&rtc_lock, flags); 145 CMOS_WRITE(0, 0xf); 146 spin_unlock_irqrestore(&rtc_lock, flags); 147 148 *((volatile u32 *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = 0; 149 } 150 151 static void init_freq_invariance(bool secondary); 152 153 /* 154 * Report back to the Boot Processor during boot time or to the caller processor 155 * during CPU online. 156 */ 157 static void smp_callin(void) 158 { 159 int cpuid; 160 161 /* 162 * If waken up by an INIT in an 82489DX configuration 163 * cpu_callout_mask guarantees we don't get here before 164 * an INIT_deassert IPI reaches our local APIC, so it is 165 * now safe to touch our local APIC. 166 */ 167 cpuid = smp_processor_id(); 168 169 /* 170 * the boot CPU has finished the init stage and is spinning 171 * on callin_map until we finish. We are free to set up this 172 * CPU, first the APIC. (this is probably redundant on most 173 * boards) 174 */ 175 apic_ap_setup(); 176 177 /* 178 * Save our processor parameters. Note: this information 179 * is needed for clock calibration. 180 */ 181 smp_store_cpu_info(cpuid); 182 183 /* 184 * The topology information must be up to date before 185 * calibrate_delay() and notify_cpu_starting(). 186 */ 187 set_cpu_sibling_map(raw_smp_processor_id()); 188 189 init_freq_invariance(true); 190 191 /* 192 * Get our bogomips. 193 * Update loops_per_jiffy in cpu_data. Previous call to 194 * smp_store_cpu_info() stored a value that is close but not as 195 * accurate as the value just calculated. 196 */ 197 calibrate_delay(); 198 cpu_data(cpuid).loops_per_jiffy = loops_per_jiffy; 199 pr_debug("Stack at about %p\n", &cpuid); 200 201 wmb(); 202 203 notify_cpu_starting(cpuid); 204 205 /* 206 * Allow the master to continue. 207 */ 208 cpumask_set_cpu(cpuid, cpu_callin_mask); 209 } 210 211 static int cpu0_logical_apicid; 212 static int enable_start_cpu0; 213 /* 214 * Activate a secondary processor. 215 */ 216 static void notrace start_secondary(void *unused) 217 { 218 /* 219 * Don't put *anything* except direct CPU state initialization 220 * before cpu_init(), SMP booting is too fragile that we want to 221 * limit the things done here to the most necessary things. 222 */ 223 cr4_init(); 224 225 #ifdef CONFIG_X86_32 226 /* switch away from the initial page table */ 227 load_cr3(swapper_pg_dir); 228 __flush_tlb_all(); 229 #endif 230 cpu_init_exception_handling(); 231 cpu_init(); 232 x86_cpuinit.early_percpu_clock_init(); 233 preempt_disable(); 234 smp_callin(); 235 236 enable_start_cpu0 = 0; 237 238 /* otherwise gcc will move up smp_processor_id before the cpu_init */ 239 barrier(); 240 /* 241 * Check TSC synchronization with the boot CPU: 242 */ 243 check_tsc_sync_target(); 244 245 speculative_store_bypass_ht_init(); 246 247 /* 248 * Lock vector_lock, set CPU online and bring the vector 249 * allocator online. Online must be set with vector_lock held 250 * to prevent a concurrent irq setup/teardown from seeing a 251 * half valid vector space. 252 */ 253 lock_vector_lock(); 254 set_cpu_online(smp_processor_id(), true); 255 lapic_online(); 256 unlock_vector_lock(); 257 cpu_set_state_online(smp_processor_id()); 258 x86_platform.nmi_init(); 259 260 /* enable local interrupts */ 261 local_irq_enable(); 262 263 x86_cpuinit.setup_percpu_clockev(); 264 265 wmb(); 266 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); 267 } 268 269 /** 270 * topology_is_primary_thread - Check whether CPU is the primary SMT thread 271 * @cpu: CPU to check 272 */ 273 bool topology_is_primary_thread(unsigned int cpu) 274 { 275 return apic_id_is_primary_thread(per_cpu(x86_cpu_to_apicid, cpu)); 276 } 277 278 /** 279 * topology_smt_supported - Check whether SMT is supported by the CPUs 280 */ 281 bool topology_smt_supported(void) 282 { 283 return smp_num_siblings > 1; 284 } 285 286 /** 287 * topology_phys_to_logical_pkg - Map a physical package id to a logical 288 * 289 * Returns logical package id or -1 if not found 290 */ 291 int topology_phys_to_logical_pkg(unsigned int phys_pkg) 292 { 293 int cpu; 294 295 for_each_possible_cpu(cpu) { 296 struct cpuinfo_x86 *c = &cpu_data(cpu); 297 298 if (c->initialized && c->phys_proc_id == phys_pkg) 299 return c->logical_proc_id; 300 } 301 return -1; 302 } 303 EXPORT_SYMBOL(topology_phys_to_logical_pkg); 304 /** 305 * topology_phys_to_logical_die - Map a physical die id to logical 306 * 307 * Returns logical die id or -1 if not found 308 */ 309 int topology_phys_to_logical_die(unsigned int die_id, unsigned int cur_cpu) 310 { 311 int cpu; 312 int proc_id = cpu_data(cur_cpu).phys_proc_id; 313 314 for_each_possible_cpu(cpu) { 315 struct cpuinfo_x86 *c = &cpu_data(cpu); 316 317 if (c->initialized && c->cpu_die_id == die_id && 318 c->phys_proc_id == proc_id) 319 return c->logical_die_id; 320 } 321 return -1; 322 } 323 EXPORT_SYMBOL(topology_phys_to_logical_die); 324 325 /** 326 * topology_update_package_map - Update the physical to logical package map 327 * @pkg: The physical package id as retrieved via CPUID 328 * @cpu: The cpu for which this is updated 329 */ 330 int topology_update_package_map(unsigned int pkg, unsigned int cpu) 331 { 332 int new; 333 334 /* Already available somewhere? */ 335 new = topology_phys_to_logical_pkg(pkg); 336 if (new >= 0) 337 goto found; 338 339 new = logical_packages++; 340 if (new != pkg) { 341 pr_info("CPU %u Converting physical %u to logical package %u\n", 342 cpu, pkg, new); 343 } 344 found: 345 cpu_data(cpu).logical_proc_id = new; 346 return 0; 347 } 348 /** 349 * topology_update_die_map - Update the physical to logical die map 350 * @die: The die id as retrieved via CPUID 351 * @cpu: The cpu for which this is updated 352 */ 353 int topology_update_die_map(unsigned int die, unsigned int cpu) 354 { 355 int new; 356 357 /* Already available somewhere? */ 358 new = topology_phys_to_logical_die(die, cpu); 359 if (new >= 0) 360 goto found; 361 362 new = logical_die++; 363 if (new != die) { 364 pr_info("CPU %u Converting physical %u to logical die %u\n", 365 cpu, die, new); 366 } 367 found: 368 cpu_data(cpu).logical_die_id = new; 369 return 0; 370 } 371 372 void __init smp_store_boot_cpu_info(void) 373 { 374 int id = 0; /* CPU 0 */ 375 struct cpuinfo_x86 *c = &cpu_data(id); 376 377 *c = boot_cpu_data; 378 c->cpu_index = id; 379 topology_update_package_map(c->phys_proc_id, id); 380 topology_update_die_map(c->cpu_die_id, id); 381 c->initialized = true; 382 } 383 384 /* 385 * The bootstrap kernel entry code has set these up. Save them for 386 * a given CPU 387 */ 388 void smp_store_cpu_info(int id) 389 { 390 struct cpuinfo_x86 *c = &cpu_data(id); 391 392 /* Copy boot_cpu_data only on the first bringup */ 393 if (!c->initialized) 394 *c = boot_cpu_data; 395 c->cpu_index = id; 396 /* 397 * During boot time, CPU0 has this setup already. Save the info when 398 * bringing up AP or offlined CPU0. 399 */ 400 identify_secondary_cpu(c); 401 c->initialized = true; 402 } 403 404 static bool 405 topology_same_node(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) 406 { 407 int cpu1 = c->cpu_index, cpu2 = o->cpu_index; 408 409 return (cpu_to_node(cpu1) == cpu_to_node(cpu2)); 410 } 411 412 static bool 413 topology_sane(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o, const char *name) 414 { 415 int cpu1 = c->cpu_index, cpu2 = o->cpu_index; 416 417 return !WARN_ONCE(!topology_same_node(c, o), 418 "sched: CPU #%d's %s-sibling CPU #%d is not on the same node! " 419 "[node: %d != %d]. Ignoring dependency.\n", 420 cpu1, name, cpu2, cpu_to_node(cpu1), cpu_to_node(cpu2)); 421 } 422 423 #define link_mask(mfunc, c1, c2) \ 424 do { \ 425 cpumask_set_cpu((c1), mfunc(c2)); \ 426 cpumask_set_cpu((c2), mfunc(c1)); \ 427 } while (0) 428 429 static bool match_smt(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) 430 { 431 if (boot_cpu_has(X86_FEATURE_TOPOEXT)) { 432 int cpu1 = c->cpu_index, cpu2 = o->cpu_index; 433 434 if (c->phys_proc_id == o->phys_proc_id && 435 c->cpu_die_id == o->cpu_die_id && 436 per_cpu(cpu_llc_id, cpu1) == per_cpu(cpu_llc_id, cpu2)) { 437 if (c->cpu_core_id == o->cpu_core_id) 438 return topology_sane(c, o, "smt"); 439 440 if ((c->cu_id != 0xff) && 441 (o->cu_id != 0xff) && 442 (c->cu_id == o->cu_id)) 443 return topology_sane(c, o, "smt"); 444 } 445 446 } else if (c->phys_proc_id == o->phys_proc_id && 447 c->cpu_die_id == o->cpu_die_id && 448 c->cpu_core_id == o->cpu_core_id) { 449 return topology_sane(c, o, "smt"); 450 } 451 452 return false; 453 } 454 455 /* 456 * Define snc_cpu[] for SNC (Sub-NUMA Cluster) CPUs. 457 * 458 * These are Intel CPUs that enumerate an LLC that is shared by 459 * multiple NUMA nodes. The LLC on these systems is shared for 460 * off-package data access but private to the NUMA node (half 461 * of the package) for on-package access. 462 * 463 * CPUID (the source of the information about the LLC) can only 464 * enumerate the cache as being shared *or* unshared, but not 465 * this particular configuration. The CPU in this case enumerates 466 * the cache to be shared across the entire package (spanning both 467 * NUMA nodes). 468 */ 469 470 static const struct x86_cpu_id snc_cpu[] = { 471 X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_X, NULL), 472 {} 473 }; 474 475 static bool match_llc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) 476 { 477 int cpu1 = c->cpu_index, cpu2 = o->cpu_index; 478 479 /* Do not match if we do not have a valid APICID for cpu: */ 480 if (per_cpu(cpu_llc_id, cpu1) == BAD_APICID) 481 return false; 482 483 /* Do not match if LLC id does not match: */ 484 if (per_cpu(cpu_llc_id, cpu1) != per_cpu(cpu_llc_id, cpu2)) 485 return false; 486 487 /* 488 * Allow the SNC topology without warning. Return of false 489 * means 'c' does not share the LLC of 'o'. This will be 490 * reflected to userspace. 491 */ 492 if (!topology_same_node(c, o) && x86_match_cpu(snc_cpu)) 493 return false; 494 495 return topology_sane(c, o, "llc"); 496 } 497 498 /* 499 * Unlike the other levels, we do not enforce keeping a 500 * multicore group inside a NUMA node. If this happens, we will 501 * discard the MC level of the topology later. 502 */ 503 static bool match_pkg(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) 504 { 505 if (c->phys_proc_id == o->phys_proc_id) 506 return true; 507 return false; 508 } 509 510 static bool match_die(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) 511 { 512 if ((c->phys_proc_id == o->phys_proc_id) && 513 (c->cpu_die_id == o->cpu_die_id)) 514 return true; 515 return false; 516 } 517 518 519 #if defined(CONFIG_SCHED_SMT) || defined(CONFIG_SCHED_MC) 520 static inline int x86_sched_itmt_flags(void) 521 { 522 return sysctl_sched_itmt_enabled ? SD_ASYM_PACKING : 0; 523 } 524 525 #ifdef CONFIG_SCHED_MC 526 static int x86_core_flags(void) 527 { 528 return cpu_core_flags() | x86_sched_itmt_flags(); 529 } 530 #endif 531 #ifdef CONFIG_SCHED_SMT 532 static int x86_smt_flags(void) 533 { 534 return cpu_smt_flags() | x86_sched_itmt_flags(); 535 } 536 #endif 537 #endif 538 539 static struct sched_domain_topology_level x86_numa_in_package_topology[] = { 540 #ifdef CONFIG_SCHED_SMT 541 { cpu_smt_mask, x86_smt_flags, SD_INIT_NAME(SMT) }, 542 #endif 543 #ifdef CONFIG_SCHED_MC 544 { cpu_coregroup_mask, x86_core_flags, SD_INIT_NAME(MC) }, 545 #endif 546 { NULL, }, 547 }; 548 549 static struct sched_domain_topology_level x86_topology[] = { 550 #ifdef CONFIG_SCHED_SMT 551 { cpu_smt_mask, x86_smt_flags, SD_INIT_NAME(SMT) }, 552 #endif 553 #ifdef CONFIG_SCHED_MC 554 { cpu_coregroup_mask, x86_core_flags, SD_INIT_NAME(MC) }, 555 #endif 556 { cpu_cpu_mask, SD_INIT_NAME(DIE) }, 557 { NULL, }, 558 }; 559 560 /* 561 * Set if a package/die has multiple NUMA nodes inside. 562 * AMD Magny-Cours, Intel Cluster-on-Die, and Intel 563 * Sub-NUMA Clustering have this. 564 */ 565 static bool x86_has_numa_in_package; 566 567 void set_cpu_sibling_map(int cpu) 568 { 569 bool has_smt = smp_num_siblings > 1; 570 bool has_mp = has_smt || boot_cpu_data.x86_max_cores > 1; 571 struct cpuinfo_x86 *c = &cpu_data(cpu); 572 struct cpuinfo_x86 *o; 573 int i, threads; 574 575 cpumask_set_cpu(cpu, cpu_sibling_setup_mask); 576 577 if (!has_mp) { 578 cpumask_set_cpu(cpu, topology_sibling_cpumask(cpu)); 579 cpumask_set_cpu(cpu, cpu_llc_shared_mask(cpu)); 580 cpumask_set_cpu(cpu, topology_core_cpumask(cpu)); 581 cpumask_set_cpu(cpu, topology_die_cpumask(cpu)); 582 c->booted_cores = 1; 583 return; 584 } 585 586 for_each_cpu(i, cpu_sibling_setup_mask) { 587 o = &cpu_data(i); 588 589 if ((i == cpu) || (has_smt && match_smt(c, o))) 590 link_mask(topology_sibling_cpumask, cpu, i); 591 592 if ((i == cpu) || (has_mp && match_llc(c, o))) 593 link_mask(cpu_llc_shared_mask, cpu, i); 594 595 } 596 597 /* 598 * This needs a separate iteration over the cpus because we rely on all 599 * topology_sibling_cpumask links to be set-up. 600 */ 601 for_each_cpu(i, cpu_sibling_setup_mask) { 602 o = &cpu_data(i); 603 604 if ((i == cpu) || (has_mp && match_pkg(c, o))) { 605 link_mask(topology_core_cpumask, cpu, i); 606 607 /* 608 * Does this new cpu bringup a new core? 609 */ 610 if (cpumask_weight( 611 topology_sibling_cpumask(cpu)) == 1) { 612 /* 613 * for each core in package, increment 614 * the booted_cores for this new cpu 615 */ 616 if (cpumask_first( 617 topology_sibling_cpumask(i)) == i) 618 c->booted_cores++; 619 /* 620 * increment the core count for all 621 * the other cpus in this package 622 */ 623 if (i != cpu) 624 cpu_data(i).booted_cores++; 625 } else if (i != cpu && !c->booted_cores) 626 c->booted_cores = cpu_data(i).booted_cores; 627 } 628 if (match_pkg(c, o) && !topology_same_node(c, o)) 629 x86_has_numa_in_package = true; 630 631 if ((i == cpu) || (has_mp && match_die(c, o))) 632 link_mask(topology_die_cpumask, cpu, i); 633 } 634 635 threads = cpumask_weight(topology_sibling_cpumask(cpu)); 636 if (threads > __max_smt_threads) 637 __max_smt_threads = threads; 638 } 639 640 /* maps the cpu to the sched domain representing multi-core */ 641 const struct cpumask *cpu_coregroup_mask(int cpu) 642 { 643 return cpu_llc_shared_mask(cpu); 644 } 645 646 static void impress_friends(void) 647 { 648 int cpu; 649 unsigned long bogosum = 0; 650 /* 651 * Allow the user to impress friends. 652 */ 653 pr_debug("Before bogomips\n"); 654 for_each_possible_cpu(cpu) 655 if (cpumask_test_cpu(cpu, cpu_callout_mask)) 656 bogosum += cpu_data(cpu).loops_per_jiffy; 657 pr_info("Total of %d processors activated (%lu.%02lu BogoMIPS)\n", 658 num_online_cpus(), 659 bogosum/(500000/HZ), 660 (bogosum/(5000/HZ))%100); 661 662 pr_debug("Before bogocount - setting activated=1\n"); 663 } 664 665 void __inquire_remote_apic(int apicid) 666 { 667 unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 }; 668 const char * const names[] = { "ID", "VERSION", "SPIV" }; 669 int timeout; 670 u32 status; 671 672 pr_info("Inquiring remote APIC 0x%x...\n", apicid); 673 674 for (i = 0; i < ARRAY_SIZE(regs); i++) { 675 pr_info("... APIC 0x%x %s: ", apicid, names[i]); 676 677 /* 678 * Wait for idle. 679 */ 680 status = safe_apic_wait_icr_idle(); 681 if (status) 682 pr_cont("a previous APIC delivery may have failed\n"); 683 684 apic_icr_write(APIC_DM_REMRD | regs[i], apicid); 685 686 timeout = 0; 687 do { 688 udelay(100); 689 status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK; 690 } while (status == APIC_ICR_RR_INPROG && timeout++ < 1000); 691 692 switch (status) { 693 case APIC_ICR_RR_VALID: 694 status = apic_read(APIC_RRR); 695 pr_cont("%08x\n", status); 696 break; 697 default: 698 pr_cont("failed\n"); 699 } 700 } 701 } 702 703 /* 704 * The Multiprocessor Specification 1.4 (1997) example code suggests 705 * that there should be a 10ms delay between the BSP asserting INIT 706 * and de-asserting INIT, when starting a remote processor. 707 * But that slows boot and resume on modern processors, which include 708 * many cores and don't require that delay. 709 * 710 * Cmdline "init_cpu_udelay=" is available to over-ride this delay. 711 * Modern processor families are quirked to remove the delay entirely. 712 */ 713 #define UDELAY_10MS_DEFAULT 10000 714 715 static unsigned int init_udelay = UINT_MAX; 716 717 static int __init cpu_init_udelay(char *str) 718 { 719 get_option(&str, &init_udelay); 720 721 return 0; 722 } 723 early_param("cpu_init_udelay", cpu_init_udelay); 724 725 static void __init smp_quirk_init_udelay(void) 726 { 727 /* if cmdline changed it from default, leave it alone */ 728 if (init_udelay != UINT_MAX) 729 return; 730 731 /* if modern processor, use no delay */ 732 if (((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && (boot_cpu_data.x86 == 6)) || 733 ((boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) && (boot_cpu_data.x86 >= 0x18)) || 734 ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && (boot_cpu_data.x86 >= 0xF))) { 735 init_udelay = 0; 736 return; 737 } 738 /* else, use legacy delay */ 739 init_udelay = UDELAY_10MS_DEFAULT; 740 } 741 742 /* 743 * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal 744 * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this 745 * won't ... remember to clear down the APIC, etc later. 746 */ 747 int 748 wakeup_secondary_cpu_via_nmi(int apicid, unsigned long start_eip) 749 { 750 unsigned long send_status, accept_status = 0; 751 int maxlvt; 752 753 /* Target chip */ 754 /* Boot on the stack */ 755 /* Kick the second */ 756 apic_icr_write(APIC_DM_NMI | apic->dest_logical, apicid); 757 758 pr_debug("Waiting for send to finish...\n"); 759 send_status = safe_apic_wait_icr_idle(); 760 761 /* 762 * Give the other CPU some time to accept the IPI. 763 */ 764 udelay(200); 765 if (APIC_INTEGRATED(boot_cpu_apic_version)) { 766 maxlvt = lapic_get_maxlvt(); 767 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ 768 apic_write(APIC_ESR, 0); 769 accept_status = (apic_read(APIC_ESR) & 0xEF); 770 } 771 pr_debug("NMI sent\n"); 772 773 if (send_status) 774 pr_err("APIC never delivered???\n"); 775 if (accept_status) 776 pr_err("APIC delivery error (%lx)\n", accept_status); 777 778 return (send_status | accept_status); 779 } 780 781 static int 782 wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip) 783 { 784 unsigned long send_status = 0, accept_status = 0; 785 int maxlvt, num_starts, j; 786 787 maxlvt = lapic_get_maxlvt(); 788 789 /* 790 * Be paranoid about clearing APIC errors. 791 */ 792 if (APIC_INTEGRATED(boot_cpu_apic_version)) { 793 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ 794 apic_write(APIC_ESR, 0); 795 apic_read(APIC_ESR); 796 } 797 798 pr_debug("Asserting INIT\n"); 799 800 /* 801 * Turn INIT on target chip 802 */ 803 /* 804 * Send IPI 805 */ 806 apic_icr_write(APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT, 807 phys_apicid); 808 809 pr_debug("Waiting for send to finish...\n"); 810 send_status = safe_apic_wait_icr_idle(); 811 812 udelay(init_udelay); 813 814 pr_debug("Deasserting INIT\n"); 815 816 /* Target chip */ 817 /* Send IPI */ 818 apic_icr_write(APIC_INT_LEVELTRIG | APIC_DM_INIT, phys_apicid); 819 820 pr_debug("Waiting for send to finish...\n"); 821 send_status = safe_apic_wait_icr_idle(); 822 823 mb(); 824 825 /* 826 * Should we send STARTUP IPIs ? 827 * 828 * Determine this based on the APIC version. 829 * If we don't have an integrated APIC, don't send the STARTUP IPIs. 830 */ 831 if (APIC_INTEGRATED(boot_cpu_apic_version)) 832 num_starts = 2; 833 else 834 num_starts = 0; 835 836 /* 837 * Run STARTUP IPI loop. 838 */ 839 pr_debug("#startup loops: %d\n", num_starts); 840 841 for (j = 1; j <= num_starts; j++) { 842 pr_debug("Sending STARTUP #%d\n", j); 843 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ 844 apic_write(APIC_ESR, 0); 845 apic_read(APIC_ESR); 846 pr_debug("After apic_write\n"); 847 848 /* 849 * STARTUP IPI 850 */ 851 852 /* Target chip */ 853 /* Boot on the stack */ 854 /* Kick the second */ 855 apic_icr_write(APIC_DM_STARTUP | (start_eip >> 12), 856 phys_apicid); 857 858 /* 859 * Give the other CPU some time to accept the IPI. 860 */ 861 if (init_udelay == 0) 862 udelay(10); 863 else 864 udelay(300); 865 866 pr_debug("Startup point 1\n"); 867 868 pr_debug("Waiting for send to finish...\n"); 869 send_status = safe_apic_wait_icr_idle(); 870 871 /* 872 * Give the other CPU some time to accept the IPI. 873 */ 874 if (init_udelay == 0) 875 udelay(10); 876 else 877 udelay(200); 878 879 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ 880 apic_write(APIC_ESR, 0); 881 accept_status = (apic_read(APIC_ESR) & 0xEF); 882 if (send_status || accept_status) 883 break; 884 } 885 pr_debug("After Startup\n"); 886 887 if (send_status) 888 pr_err("APIC never delivered???\n"); 889 if (accept_status) 890 pr_err("APIC delivery error (%lx)\n", accept_status); 891 892 return (send_status | accept_status); 893 } 894 895 /* reduce the number of lines printed when booting a large cpu count system */ 896 static void announce_cpu(int cpu, int apicid) 897 { 898 static int current_node = NUMA_NO_NODE; 899 int node = early_cpu_to_node(cpu); 900 static int width, node_width; 901 902 if (!width) 903 width = num_digits(num_possible_cpus()) + 1; /* + '#' sign */ 904 905 if (!node_width) 906 node_width = num_digits(num_possible_nodes()) + 1; /* + '#' */ 907 908 if (cpu == 1) 909 printk(KERN_INFO "x86: Booting SMP configuration:\n"); 910 911 if (system_state < SYSTEM_RUNNING) { 912 if (node != current_node) { 913 if (current_node > (-1)) 914 pr_cont("\n"); 915 current_node = node; 916 917 printk(KERN_INFO ".... node %*s#%d, CPUs: ", 918 node_width - num_digits(node), " ", node); 919 } 920 921 /* Add padding for the BSP */ 922 if (cpu == 1) 923 pr_cont("%*s", width + 1, " "); 924 925 pr_cont("%*s#%d", width - num_digits(cpu), " ", cpu); 926 927 } else 928 pr_info("Booting Node %d Processor %d APIC 0x%x\n", 929 node, cpu, apicid); 930 } 931 932 static int wakeup_cpu0_nmi(unsigned int cmd, struct pt_regs *regs) 933 { 934 int cpu; 935 936 cpu = smp_processor_id(); 937 if (cpu == 0 && !cpu_online(cpu) && enable_start_cpu0) 938 return NMI_HANDLED; 939 940 return NMI_DONE; 941 } 942 943 /* 944 * Wake up AP by INIT, INIT, STARTUP sequence. 945 * 946 * Instead of waiting for STARTUP after INITs, BSP will execute the BIOS 947 * boot-strap code which is not a desired behavior for waking up BSP. To 948 * void the boot-strap code, wake up CPU0 by NMI instead. 949 * 950 * This works to wake up soft offlined CPU0 only. If CPU0 is hard offlined 951 * (i.e. physically hot removed and then hot added), NMI won't wake it up. 952 * We'll change this code in the future to wake up hard offlined CPU0 if 953 * real platform and request are available. 954 */ 955 static int 956 wakeup_cpu_via_init_nmi(int cpu, unsigned long start_ip, int apicid, 957 int *cpu0_nmi_registered) 958 { 959 int id; 960 int boot_error; 961 962 preempt_disable(); 963 964 /* 965 * Wake up AP by INIT, INIT, STARTUP sequence. 966 */ 967 if (cpu) { 968 boot_error = wakeup_secondary_cpu_via_init(apicid, start_ip); 969 goto out; 970 } 971 972 /* 973 * Wake up BSP by nmi. 974 * 975 * Register a NMI handler to help wake up CPU0. 976 */ 977 boot_error = register_nmi_handler(NMI_LOCAL, 978 wakeup_cpu0_nmi, 0, "wake_cpu0"); 979 980 if (!boot_error) { 981 enable_start_cpu0 = 1; 982 *cpu0_nmi_registered = 1; 983 if (apic->dest_logical == APIC_DEST_LOGICAL) 984 id = cpu0_logical_apicid; 985 else 986 id = apicid; 987 boot_error = wakeup_secondary_cpu_via_nmi(id, start_ip); 988 } 989 990 out: 991 preempt_enable(); 992 993 return boot_error; 994 } 995 996 int common_cpu_up(unsigned int cpu, struct task_struct *idle) 997 { 998 int ret; 999 1000 /* Just in case we booted with a single CPU. */ 1001 alternatives_enable_smp(); 1002 1003 per_cpu(current_task, cpu) = idle; 1004 cpu_init_stack_canary(cpu, idle); 1005 1006 /* Initialize the interrupt stack(s) */ 1007 ret = irq_init_percpu_irqstack(cpu); 1008 if (ret) 1009 return ret; 1010 1011 #ifdef CONFIG_X86_32 1012 /* Stack for startup_32 can be just as for start_secondary onwards */ 1013 per_cpu(cpu_current_top_of_stack, cpu) = task_top_of_stack(idle); 1014 #else 1015 initial_gs = per_cpu_offset(cpu); 1016 #endif 1017 return 0; 1018 } 1019 1020 /* 1021 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad 1022 * (ie clustered apic addressing mode), this is a LOGICAL apic ID. 1023 * Returns zero if CPU booted OK, else error code from 1024 * ->wakeup_secondary_cpu. 1025 */ 1026 static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle, 1027 int *cpu0_nmi_registered) 1028 { 1029 /* start_ip had better be page-aligned! */ 1030 unsigned long start_ip = real_mode_header->trampoline_start; 1031 1032 unsigned long boot_error = 0; 1033 unsigned long timeout; 1034 1035 idle->thread.sp = (unsigned long)task_pt_regs(idle); 1036 early_gdt_descr.address = (unsigned long)get_cpu_gdt_rw(cpu); 1037 initial_code = (unsigned long)start_secondary; 1038 initial_stack = idle->thread.sp; 1039 1040 /* Enable the espfix hack for this CPU */ 1041 init_espfix_ap(cpu); 1042 1043 /* So we see what's up */ 1044 announce_cpu(cpu, apicid); 1045 1046 /* 1047 * This grunge runs the startup process for 1048 * the targeted processor. 1049 */ 1050 1051 if (x86_platform.legacy.warm_reset) { 1052 1053 pr_debug("Setting warm reset code and vector.\n"); 1054 1055 smpboot_setup_warm_reset_vector(start_ip); 1056 /* 1057 * Be paranoid about clearing APIC errors. 1058 */ 1059 if (APIC_INTEGRATED(boot_cpu_apic_version)) { 1060 apic_write(APIC_ESR, 0); 1061 apic_read(APIC_ESR); 1062 } 1063 } 1064 1065 /* 1066 * AP might wait on cpu_callout_mask in cpu_init() with 1067 * cpu_initialized_mask set if previous attempt to online 1068 * it timed-out. Clear cpu_initialized_mask so that after 1069 * INIT/SIPI it could start with a clean state. 1070 */ 1071 cpumask_clear_cpu(cpu, cpu_initialized_mask); 1072 smp_mb(); 1073 1074 /* 1075 * Wake up a CPU in difference cases: 1076 * - Use the method in the APIC driver if it's defined 1077 * Otherwise, 1078 * - Use an INIT boot APIC message for APs or NMI for BSP. 1079 */ 1080 if (apic->wakeup_secondary_cpu) 1081 boot_error = apic->wakeup_secondary_cpu(apicid, start_ip); 1082 else 1083 boot_error = wakeup_cpu_via_init_nmi(cpu, start_ip, apicid, 1084 cpu0_nmi_registered); 1085 1086 if (!boot_error) { 1087 /* 1088 * Wait 10s total for first sign of life from AP 1089 */ 1090 boot_error = -1; 1091 timeout = jiffies + 10*HZ; 1092 while (time_before(jiffies, timeout)) { 1093 if (cpumask_test_cpu(cpu, cpu_initialized_mask)) { 1094 /* 1095 * Tell AP to proceed with initialization 1096 */ 1097 cpumask_set_cpu(cpu, cpu_callout_mask); 1098 boot_error = 0; 1099 break; 1100 } 1101 schedule(); 1102 } 1103 } 1104 1105 if (!boot_error) { 1106 /* 1107 * Wait till AP completes initial initialization 1108 */ 1109 while (!cpumask_test_cpu(cpu, cpu_callin_mask)) { 1110 /* 1111 * Allow other tasks to run while we wait for the 1112 * AP to come online. This also gives a chance 1113 * for the MTRR work(triggered by the AP coming online) 1114 * to be completed in the stop machine context. 1115 */ 1116 schedule(); 1117 } 1118 } 1119 1120 if (x86_platform.legacy.warm_reset) { 1121 /* 1122 * Cleanup possible dangling ends... 1123 */ 1124 smpboot_restore_warm_reset_vector(); 1125 } 1126 1127 return boot_error; 1128 } 1129 1130 int native_cpu_up(unsigned int cpu, struct task_struct *tidle) 1131 { 1132 int apicid = apic->cpu_present_to_apicid(cpu); 1133 int cpu0_nmi_registered = 0; 1134 unsigned long flags; 1135 int err, ret = 0; 1136 1137 lockdep_assert_irqs_enabled(); 1138 1139 pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu); 1140 1141 if (apicid == BAD_APICID || 1142 !physid_isset(apicid, phys_cpu_present_map) || 1143 !apic->apic_id_valid(apicid)) { 1144 pr_err("%s: bad cpu %d\n", __func__, cpu); 1145 return -EINVAL; 1146 } 1147 1148 /* 1149 * Already booted CPU? 1150 */ 1151 if (cpumask_test_cpu(cpu, cpu_callin_mask)) { 1152 pr_debug("do_boot_cpu %d Already started\n", cpu); 1153 return -ENOSYS; 1154 } 1155 1156 /* 1157 * Save current MTRR state in case it was changed since early boot 1158 * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync: 1159 */ 1160 mtrr_save_state(); 1161 1162 /* x86 CPUs take themselves offline, so delayed offline is OK. */ 1163 err = cpu_check_up_prepare(cpu); 1164 if (err && err != -EBUSY) 1165 return err; 1166 1167 /* the FPU context is blank, nobody can own it */ 1168 per_cpu(fpu_fpregs_owner_ctx, cpu) = NULL; 1169 1170 err = common_cpu_up(cpu, tidle); 1171 if (err) 1172 return err; 1173 1174 err = do_boot_cpu(apicid, cpu, tidle, &cpu0_nmi_registered); 1175 if (err) { 1176 pr_err("do_boot_cpu failed(%d) to wakeup CPU#%u\n", err, cpu); 1177 ret = -EIO; 1178 goto unreg_nmi; 1179 } 1180 1181 /* 1182 * Check TSC synchronization with the AP (keep irqs disabled 1183 * while doing so): 1184 */ 1185 local_irq_save(flags); 1186 check_tsc_sync_source(cpu); 1187 local_irq_restore(flags); 1188 1189 while (!cpu_online(cpu)) { 1190 cpu_relax(); 1191 touch_nmi_watchdog(); 1192 } 1193 1194 unreg_nmi: 1195 /* 1196 * Clean up the nmi handler. Do this after the callin and callout sync 1197 * to avoid impact of possible long unregister time. 1198 */ 1199 if (cpu0_nmi_registered) 1200 unregister_nmi_handler(NMI_LOCAL, "wake_cpu0"); 1201 1202 return ret; 1203 } 1204 1205 /** 1206 * arch_disable_smp_support() - disables SMP support for x86 at runtime 1207 */ 1208 void arch_disable_smp_support(void) 1209 { 1210 disable_ioapic_support(); 1211 } 1212 1213 /* 1214 * Fall back to non SMP mode after errors. 1215 * 1216 * RED-PEN audit/test this more. I bet there is more state messed up here. 1217 */ 1218 static __init void disable_smp(void) 1219 { 1220 pr_info("SMP disabled\n"); 1221 1222 disable_ioapic_support(); 1223 1224 init_cpu_present(cpumask_of(0)); 1225 init_cpu_possible(cpumask_of(0)); 1226 1227 if (smp_found_config) 1228 physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map); 1229 else 1230 physid_set_mask_of_physid(0, &phys_cpu_present_map); 1231 cpumask_set_cpu(0, topology_sibling_cpumask(0)); 1232 cpumask_set_cpu(0, topology_core_cpumask(0)); 1233 cpumask_set_cpu(0, topology_die_cpumask(0)); 1234 } 1235 1236 /* 1237 * Various sanity checks. 1238 */ 1239 static void __init smp_sanity_check(void) 1240 { 1241 preempt_disable(); 1242 1243 #if !defined(CONFIG_X86_BIGSMP) && defined(CONFIG_X86_32) 1244 if (def_to_bigsmp && nr_cpu_ids > 8) { 1245 unsigned int cpu; 1246 unsigned nr; 1247 1248 pr_warn("More than 8 CPUs detected - skipping them\n" 1249 "Use CONFIG_X86_BIGSMP\n"); 1250 1251 nr = 0; 1252 for_each_present_cpu(cpu) { 1253 if (nr >= 8) 1254 set_cpu_present(cpu, false); 1255 nr++; 1256 } 1257 1258 nr = 0; 1259 for_each_possible_cpu(cpu) { 1260 if (nr >= 8) 1261 set_cpu_possible(cpu, false); 1262 nr++; 1263 } 1264 1265 nr_cpu_ids = 8; 1266 } 1267 #endif 1268 1269 if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) { 1270 pr_warn("weird, boot CPU (#%d) not listed by the BIOS\n", 1271 hard_smp_processor_id()); 1272 1273 physid_set(hard_smp_processor_id(), phys_cpu_present_map); 1274 } 1275 1276 /* 1277 * Should not be necessary because the MP table should list the boot 1278 * CPU too, but we do it for the sake of robustness anyway. 1279 */ 1280 if (!apic->check_phys_apicid_present(boot_cpu_physical_apicid)) { 1281 pr_notice("weird, boot CPU (#%d) not listed by the BIOS\n", 1282 boot_cpu_physical_apicid); 1283 physid_set(hard_smp_processor_id(), phys_cpu_present_map); 1284 } 1285 preempt_enable(); 1286 } 1287 1288 static void __init smp_cpu_index_default(void) 1289 { 1290 int i; 1291 struct cpuinfo_x86 *c; 1292 1293 for_each_possible_cpu(i) { 1294 c = &cpu_data(i); 1295 /* mark all to hotplug */ 1296 c->cpu_index = nr_cpu_ids; 1297 } 1298 } 1299 1300 static void __init smp_get_logical_apicid(void) 1301 { 1302 if (x2apic_mode) 1303 cpu0_logical_apicid = apic_read(APIC_LDR); 1304 else 1305 cpu0_logical_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR)); 1306 } 1307 1308 /* 1309 * Prepare for SMP bootup. 1310 * @max_cpus: configured maximum number of CPUs, It is a legacy parameter 1311 * for common interface support. 1312 */ 1313 void __init native_smp_prepare_cpus(unsigned int max_cpus) 1314 { 1315 unsigned int i; 1316 1317 smp_cpu_index_default(); 1318 1319 /* 1320 * Setup boot CPU information 1321 */ 1322 smp_store_boot_cpu_info(); /* Final full version of the data */ 1323 cpumask_copy(cpu_callin_mask, cpumask_of(0)); 1324 mb(); 1325 1326 for_each_possible_cpu(i) { 1327 zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL); 1328 zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL); 1329 zalloc_cpumask_var(&per_cpu(cpu_die_map, i), GFP_KERNEL); 1330 zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL); 1331 } 1332 1333 /* 1334 * Set 'default' x86 topology, this matches default_topology() in that 1335 * it has NUMA nodes as a topology level. See also 1336 * native_smp_cpus_done(). 1337 * 1338 * Must be done before set_cpus_sibling_map() is ran. 1339 */ 1340 set_sched_topology(x86_topology); 1341 1342 set_cpu_sibling_map(0); 1343 init_freq_invariance(false); 1344 smp_sanity_check(); 1345 1346 switch (apic_intr_mode) { 1347 case APIC_PIC: 1348 case APIC_VIRTUAL_WIRE_NO_CONFIG: 1349 disable_smp(); 1350 return; 1351 case APIC_SYMMETRIC_IO_NO_ROUTING: 1352 disable_smp(); 1353 /* Setup local timer */ 1354 x86_init.timers.setup_percpu_clockev(); 1355 return; 1356 case APIC_VIRTUAL_WIRE: 1357 case APIC_SYMMETRIC_IO: 1358 break; 1359 } 1360 1361 /* Setup local timer */ 1362 x86_init.timers.setup_percpu_clockev(); 1363 1364 smp_get_logical_apicid(); 1365 1366 pr_info("CPU0: "); 1367 print_cpu_info(&cpu_data(0)); 1368 1369 uv_system_init(); 1370 1371 set_mtrr_aps_delayed_init(); 1372 1373 smp_quirk_init_udelay(); 1374 1375 speculative_store_bypass_ht_init(); 1376 } 1377 1378 void arch_thaw_secondary_cpus_begin(void) 1379 { 1380 set_mtrr_aps_delayed_init(); 1381 } 1382 1383 void arch_thaw_secondary_cpus_end(void) 1384 { 1385 mtrr_aps_init(); 1386 } 1387 1388 /* 1389 * Early setup to make printk work. 1390 */ 1391 void __init native_smp_prepare_boot_cpu(void) 1392 { 1393 int me = smp_processor_id(); 1394 switch_to_new_gdt(me); 1395 /* already set me in cpu_online_mask in boot_cpu_init() */ 1396 cpumask_set_cpu(me, cpu_callout_mask); 1397 cpu_set_state_online(me); 1398 native_pv_lock_init(); 1399 } 1400 1401 void __init calculate_max_logical_packages(void) 1402 { 1403 int ncpus; 1404 1405 /* 1406 * Today neither Intel nor AMD support heterogenous systems so 1407 * extrapolate the boot cpu's data to all packages. 1408 */ 1409 ncpus = cpu_data(0).booted_cores * topology_max_smt_threads(); 1410 __max_logical_packages = DIV_ROUND_UP(total_cpus, ncpus); 1411 pr_info("Max logical packages: %u\n", __max_logical_packages); 1412 } 1413 1414 void __init native_smp_cpus_done(unsigned int max_cpus) 1415 { 1416 pr_debug("Boot done\n"); 1417 1418 calculate_max_logical_packages(); 1419 1420 if (x86_has_numa_in_package) 1421 set_sched_topology(x86_numa_in_package_topology); 1422 1423 nmi_selftest(); 1424 impress_friends(); 1425 mtrr_aps_init(); 1426 } 1427 1428 static int __initdata setup_possible_cpus = -1; 1429 static int __init _setup_possible_cpus(char *str) 1430 { 1431 get_option(&str, &setup_possible_cpus); 1432 return 0; 1433 } 1434 early_param("possible_cpus", _setup_possible_cpus); 1435 1436 1437 /* 1438 * cpu_possible_mask should be static, it cannot change as cpu's 1439 * are onlined, or offlined. The reason is per-cpu data-structures 1440 * are allocated by some modules at init time, and don't expect to 1441 * do this dynamically on cpu arrival/departure. 1442 * cpu_present_mask on the other hand can change dynamically. 1443 * In case when cpu_hotplug is not compiled, then we resort to current 1444 * behaviour, which is cpu_possible == cpu_present. 1445 * - Ashok Raj 1446 * 1447 * Three ways to find out the number of additional hotplug CPUs: 1448 * - If the BIOS specified disabled CPUs in ACPI/mptables use that. 1449 * - The user can overwrite it with possible_cpus=NUM 1450 * - Otherwise don't reserve additional CPUs. 1451 * We do this because additional CPUs waste a lot of memory. 1452 * -AK 1453 */ 1454 __init void prefill_possible_map(void) 1455 { 1456 int i, possible; 1457 1458 /* No boot processor was found in mptable or ACPI MADT */ 1459 if (!num_processors) { 1460 if (boot_cpu_has(X86_FEATURE_APIC)) { 1461 int apicid = boot_cpu_physical_apicid; 1462 int cpu = hard_smp_processor_id(); 1463 1464 pr_warn("Boot CPU (id %d) not listed by BIOS\n", cpu); 1465 1466 /* Make sure boot cpu is enumerated */ 1467 if (apic->cpu_present_to_apicid(0) == BAD_APICID && 1468 apic->apic_id_valid(apicid)) 1469 generic_processor_info(apicid, boot_cpu_apic_version); 1470 } 1471 1472 if (!num_processors) 1473 num_processors = 1; 1474 } 1475 1476 i = setup_max_cpus ?: 1; 1477 if (setup_possible_cpus == -1) { 1478 possible = num_processors; 1479 #ifdef CONFIG_HOTPLUG_CPU 1480 if (setup_max_cpus) 1481 possible += disabled_cpus; 1482 #else 1483 if (possible > i) 1484 possible = i; 1485 #endif 1486 } else 1487 possible = setup_possible_cpus; 1488 1489 total_cpus = max_t(int, possible, num_processors + disabled_cpus); 1490 1491 /* nr_cpu_ids could be reduced via nr_cpus= */ 1492 if (possible > nr_cpu_ids) { 1493 pr_warn("%d Processors exceeds NR_CPUS limit of %u\n", 1494 possible, nr_cpu_ids); 1495 possible = nr_cpu_ids; 1496 } 1497 1498 #ifdef CONFIG_HOTPLUG_CPU 1499 if (!setup_max_cpus) 1500 #endif 1501 if (possible > i) { 1502 pr_warn("%d Processors exceeds max_cpus limit of %u\n", 1503 possible, setup_max_cpus); 1504 possible = i; 1505 } 1506 1507 nr_cpu_ids = possible; 1508 1509 pr_info("Allowing %d CPUs, %d hotplug CPUs\n", 1510 possible, max_t(int, possible - num_processors, 0)); 1511 1512 reset_cpu_possible_mask(); 1513 1514 for (i = 0; i < possible; i++) 1515 set_cpu_possible(i, true); 1516 } 1517 1518 #ifdef CONFIG_HOTPLUG_CPU 1519 1520 /* Recompute SMT state for all CPUs on offline */ 1521 static void recompute_smt_state(void) 1522 { 1523 int max_threads, cpu; 1524 1525 max_threads = 0; 1526 for_each_online_cpu (cpu) { 1527 int threads = cpumask_weight(topology_sibling_cpumask(cpu)); 1528 1529 if (threads > max_threads) 1530 max_threads = threads; 1531 } 1532 __max_smt_threads = max_threads; 1533 } 1534 1535 static void remove_siblinginfo(int cpu) 1536 { 1537 int sibling; 1538 struct cpuinfo_x86 *c = &cpu_data(cpu); 1539 1540 for_each_cpu(sibling, topology_core_cpumask(cpu)) { 1541 cpumask_clear_cpu(cpu, topology_core_cpumask(sibling)); 1542 /*/ 1543 * last thread sibling in this cpu core going down 1544 */ 1545 if (cpumask_weight(topology_sibling_cpumask(cpu)) == 1) 1546 cpu_data(sibling).booted_cores--; 1547 } 1548 1549 for_each_cpu(sibling, topology_die_cpumask(cpu)) 1550 cpumask_clear_cpu(cpu, topology_die_cpumask(sibling)); 1551 for_each_cpu(sibling, topology_sibling_cpumask(cpu)) 1552 cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling)); 1553 for_each_cpu(sibling, cpu_llc_shared_mask(cpu)) 1554 cpumask_clear_cpu(cpu, cpu_llc_shared_mask(sibling)); 1555 cpumask_clear(cpu_llc_shared_mask(cpu)); 1556 cpumask_clear(topology_sibling_cpumask(cpu)); 1557 cpumask_clear(topology_core_cpumask(cpu)); 1558 cpumask_clear(topology_die_cpumask(cpu)); 1559 c->cpu_core_id = 0; 1560 c->booted_cores = 0; 1561 cpumask_clear_cpu(cpu, cpu_sibling_setup_mask); 1562 recompute_smt_state(); 1563 } 1564 1565 static void remove_cpu_from_maps(int cpu) 1566 { 1567 set_cpu_online(cpu, false); 1568 cpumask_clear_cpu(cpu, cpu_callout_mask); 1569 cpumask_clear_cpu(cpu, cpu_callin_mask); 1570 /* was set by cpu_init() */ 1571 cpumask_clear_cpu(cpu, cpu_initialized_mask); 1572 numa_remove_cpu(cpu); 1573 } 1574 1575 void cpu_disable_common(void) 1576 { 1577 int cpu = smp_processor_id(); 1578 1579 remove_siblinginfo(cpu); 1580 1581 /* It's now safe to remove this processor from the online map */ 1582 lock_vector_lock(); 1583 remove_cpu_from_maps(cpu); 1584 unlock_vector_lock(); 1585 fixup_irqs(); 1586 lapic_offline(); 1587 } 1588 1589 int native_cpu_disable(void) 1590 { 1591 int ret; 1592 1593 ret = lapic_can_unplug_cpu(); 1594 if (ret) 1595 return ret; 1596 1597 cpu_disable_common(); 1598 1599 /* 1600 * Disable the local APIC. Otherwise IPI broadcasts will reach 1601 * it. It still responds normally to INIT, NMI, SMI, and SIPI 1602 * messages. 1603 * 1604 * Disabling the APIC must happen after cpu_disable_common() 1605 * which invokes fixup_irqs(). 1606 * 1607 * Disabling the APIC preserves already set bits in IRR, but 1608 * an interrupt arriving after disabling the local APIC does not 1609 * set the corresponding IRR bit. 1610 * 1611 * fixup_irqs() scans IRR for set bits so it can raise a not 1612 * yet handled interrupt on the new destination CPU via an IPI 1613 * but obviously it can't do so for IRR bits which are not set. 1614 * IOW, interrupts arriving after disabling the local APIC will 1615 * be lost. 1616 */ 1617 apic_soft_disable(); 1618 1619 return 0; 1620 } 1621 1622 int common_cpu_die(unsigned int cpu) 1623 { 1624 int ret = 0; 1625 1626 /* We don't do anything here: idle task is faking death itself. */ 1627 1628 /* They ack this in play_dead() by setting CPU_DEAD */ 1629 if (cpu_wait_death(cpu, 5)) { 1630 if (system_state == SYSTEM_RUNNING) 1631 pr_info("CPU %u is now offline\n", cpu); 1632 } else { 1633 pr_err("CPU %u didn't die...\n", cpu); 1634 ret = -1; 1635 } 1636 1637 return ret; 1638 } 1639 1640 void native_cpu_die(unsigned int cpu) 1641 { 1642 common_cpu_die(cpu); 1643 } 1644 1645 void play_dead_common(void) 1646 { 1647 idle_task_exit(); 1648 1649 /* Ack it */ 1650 (void)cpu_report_death(); 1651 1652 /* 1653 * With physical CPU hotplug, we should halt the cpu 1654 */ 1655 local_irq_disable(); 1656 } 1657 1658 static bool wakeup_cpu0(void) 1659 { 1660 if (smp_processor_id() == 0 && enable_start_cpu0) 1661 return true; 1662 1663 return false; 1664 } 1665 1666 /* 1667 * We need to flush the caches before going to sleep, lest we have 1668 * dirty data in our caches when we come back up. 1669 */ 1670 static inline void mwait_play_dead(void) 1671 { 1672 unsigned int eax, ebx, ecx, edx; 1673 unsigned int highest_cstate = 0; 1674 unsigned int highest_subcstate = 0; 1675 void *mwait_ptr; 1676 int i; 1677 1678 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD || 1679 boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) 1680 return; 1681 if (!this_cpu_has(X86_FEATURE_MWAIT)) 1682 return; 1683 if (!this_cpu_has(X86_FEATURE_CLFLUSH)) 1684 return; 1685 if (__this_cpu_read(cpu_info.cpuid_level) < CPUID_MWAIT_LEAF) 1686 return; 1687 1688 eax = CPUID_MWAIT_LEAF; 1689 ecx = 0; 1690 native_cpuid(&eax, &ebx, &ecx, &edx); 1691 1692 /* 1693 * eax will be 0 if EDX enumeration is not valid. 1694 * Initialized below to cstate, sub_cstate value when EDX is valid. 1695 */ 1696 if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED)) { 1697 eax = 0; 1698 } else { 1699 edx >>= MWAIT_SUBSTATE_SIZE; 1700 for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) { 1701 if (edx & MWAIT_SUBSTATE_MASK) { 1702 highest_cstate = i; 1703 highest_subcstate = edx & MWAIT_SUBSTATE_MASK; 1704 } 1705 } 1706 eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) | 1707 (highest_subcstate - 1); 1708 } 1709 1710 /* 1711 * This should be a memory location in a cache line which is 1712 * unlikely to be touched by other processors. The actual 1713 * content is immaterial as it is not actually modified in any way. 1714 */ 1715 mwait_ptr = ¤t_thread_info()->flags; 1716 1717 wbinvd(); 1718 1719 while (1) { 1720 /* 1721 * The CLFLUSH is a workaround for erratum AAI65 for 1722 * the Xeon 7400 series. It's not clear it is actually 1723 * needed, but it should be harmless in either case. 1724 * The WBINVD is insufficient due to the spurious-wakeup 1725 * case where we return around the loop. 1726 */ 1727 mb(); 1728 clflush(mwait_ptr); 1729 mb(); 1730 __monitor(mwait_ptr, 0, 0); 1731 mb(); 1732 __mwait(eax, 0); 1733 /* 1734 * If NMI wants to wake up CPU0, start CPU0. 1735 */ 1736 if (wakeup_cpu0()) 1737 start_cpu0(); 1738 } 1739 } 1740 1741 void hlt_play_dead(void) 1742 { 1743 if (__this_cpu_read(cpu_info.x86) >= 4) 1744 wbinvd(); 1745 1746 while (1) { 1747 native_halt(); 1748 /* 1749 * If NMI wants to wake up CPU0, start CPU0. 1750 */ 1751 if (wakeup_cpu0()) 1752 start_cpu0(); 1753 } 1754 } 1755 1756 void native_play_dead(void) 1757 { 1758 play_dead_common(); 1759 tboot_shutdown(TB_SHUTDOWN_WFS); 1760 1761 mwait_play_dead(); /* Only returns on failure */ 1762 if (cpuidle_play_dead()) 1763 hlt_play_dead(); 1764 } 1765 1766 #else /* ... !CONFIG_HOTPLUG_CPU */ 1767 int native_cpu_disable(void) 1768 { 1769 return -ENOSYS; 1770 } 1771 1772 void native_cpu_die(unsigned int cpu) 1773 { 1774 /* We said "no" in __cpu_disable */ 1775 BUG(); 1776 } 1777 1778 void native_play_dead(void) 1779 { 1780 BUG(); 1781 } 1782 1783 #endif 1784 1785 #ifdef CONFIG_X86_64 1786 /* 1787 * APERF/MPERF frequency ratio computation. 1788 * 1789 * The scheduler wants to do frequency invariant accounting and needs a <1 1790 * ratio to account for the 'current' frequency, corresponding to 1791 * freq_curr / freq_max. 1792 * 1793 * Since the frequency freq_curr on x86 is controlled by micro-controller and 1794 * our P-state setting is little more than a request/hint, we need to observe 1795 * the effective frequency 'BusyMHz', i.e. the average frequency over a time 1796 * interval after discarding idle time. This is given by: 1797 * 1798 * BusyMHz = delta_APERF / delta_MPERF * freq_base 1799 * 1800 * where freq_base is the max non-turbo P-state. 1801 * 1802 * The freq_max term has to be set to a somewhat arbitrary value, because we 1803 * can't know which turbo states will be available at a given point in time: 1804 * it all depends on the thermal headroom of the entire package. We set it to 1805 * the turbo level with 4 cores active. 1806 * 1807 * Benchmarks show that's a good compromise between the 1C turbo ratio 1808 * (freq_curr/freq_max would rarely reach 1) and something close to freq_base, 1809 * which would ignore the entire turbo range (a conspicuous part, making 1810 * freq_curr/freq_max always maxed out). 1811 * 1812 * An exception to the heuristic above is the Atom uarch, where we choose the 1813 * highest turbo level for freq_max since Atom's are generally oriented towards 1814 * power efficiency. 1815 * 1816 * Setting freq_max to anything less than the 1C turbo ratio makes the ratio 1817 * freq_curr / freq_max to eventually grow >1, in which case we clip it to 1. 1818 */ 1819 1820 DEFINE_STATIC_KEY_FALSE(arch_scale_freq_key); 1821 1822 static DEFINE_PER_CPU(u64, arch_prev_aperf); 1823 static DEFINE_PER_CPU(u64, arch_prev_mperf); 1824 static u64 arch_turbo_freq_ratio = SCHED_CAPACITY_SCALE; 1825 static u64 arch_max_freq_ratio = SCHED_CAPACITY_SCALE; 1826 1827 void arch_set_max_freq_ratio(bool turbo_disabled) 1828 { 1829 arch_max_freq_ratio = turbo_disabled ? SCHED_CAPACITY_SCALE : 1830 arch_turbo_freq_ratio; 1831 } 1832 1833 static bool turbo_disabled(void) 1834 { 1835 u64 misc_en; 1836 int err; 1837 1838 err = rdmsrl_safe(MSR_IA32_MISC_ENABLE, &misc_en); 1839 if (err) 1840 return false; 1841 1842 return (misc_en & MSR_IA32_MISC_ENABLE_TURBO_DISABLE); 1843 } 1844 1845 static bool slv_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq) 1846 { 1847 int err; 1848 1849 err = rdmsrl_safe(MSR_ATOM_CORE_RATIOS, base_freq); 1850 if (err) 1851 return false; 1852 1853 err = rdmsrl_safe(MSR_ATOM_CORE_TURBO_RATIOS, turbo_freq); 1854 if (err) 1855 return false; 1856 1857 *base_freq = (*base_freq >> 16) & 0x3F; /* max P state */ 1858 *turbo_freq = *turbo_freq & 0x3F; /* 1C turbo */ 1859 1860 return true; 1861 } 1862 1863 #include <asm/cpu_device_id.h> 1864 #include <asm/intel-family.h> 1865 1866 #define X86_MATCH(model) \ 1867 X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6, \ 1868 INTEL_FAM6_##model, X86_FEATURE_APERFMPERF, NULL) 1869 1870 static const struct x86_cpu_id has_knl_turbo_ratio_limits[] = { 1871 X86_MATCH(XEON_PHI_KNL), 1872 X86_MATCH(XEON_PHI_KNM), 1873 {} 1874 }; 1875 1876 static const struct x86_cpu_id has_skx_turbo_ratio_limits[] = { 1877 X86_MATCH(SKYLAKE_X), 1878 {} 1879 }; 1880 1881 static const struct x86_cpu_id has_glm_turbo_ratio_limits[] = { 1882 X86_MATCH(ATOM_GOLDMONT), 1883 X86_MATCH(ATOM_GOLDMONT_D), 1884 X86_MATCH(ATOM_GOLDMONT_PLUS), 1885 {} 1886 }; 1887 1888 static bool knl_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq, 1889 int num_delta_fratio) 1890 { 1891 int fratio, delta_fratio, found; 1892 int err, i; 1893 u64 msr; 1894 1895 err = rdmsrl_safe(MSR_PLATFORM_INFO, base_freq); 1896 if (err) 1897 return false; 1898 1899 *base_freq = (*base_freq >> 8) & 0xFF; /* max P state */ 1900 1901 err = rdmsrl_safe(MSR_TURBO_RATIO_LIMIT, &msr); 1902 if (err) 1903 return false; 1904 1905 fratio = (msr >> 8) & 0xFF; 1906 i = 16; 1907 found = 0; 1908 do { 1909 if (found >= num_delta_fratio) { 1910 *turbo_freq = fratio; 1911 return true; 1912 } 1913 1914 delta_fratio = (msr >> (i + 5)) & 0x7; 1915 1916 if (delta_fratio) { 1917 found += 1; 1918 fratio -= delta_fratio; 1919 } 1920 1921 i += 8; 1922 } while (i < 64); 1923 1924 return true; 1925 } 1926 1927 static bool skx_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq, int size) 1928 { 1929 u64 ratios, counts; 1930 u32 group_size; 1931 int err, i; 1932 1933 err = rdmsrl_safe(MSR_PLATFORM_INFO, base_freq); 1934 if (err) 1935 return false; 1936 1937 *base_freq = (*base_freq >> 8) & 0xFF; /* max P state */ 1938 1939 err = rdmsrl_safe(MSR_TURBO_RATIO_LIMIT, &ratios); 1940 if (err) 1941 return false; 1942 1943 err = rdmsrl_safe(MSR_TURBO_RATIO_LIMIT1, &counts); 1944 if (err) 1945 return false; 1946 1947 for (i = 0; i < 64; i += 8) { 1948 group_size = (counts >> i) & 0xFF; 1949 if (group_size >= size) { 1950 *turbo_freq = (ratios >> i) & 0xFF; 1951 return true; 1952 } 1953 } 1954 1955 return false; 1956 } 1957 1958 static bool core_set_max_freq_ratio(u64 *base_freq, u64 *turbo_freq) 1959 { 1960 u64 msr; 1961 int err; 1962 1963 err = rdmsrl_safe(MSR_PLATFORM_INFO, base_freq); 1964 if (err) 1965 return false; 1966 1967 err = rdmsrl_safe(MSR_TURBO_RATIO_LIMIT, &msr); 1968 if (err) 1969 return false; 1970 1971 *base_freq = (*base_freq >> 8) & 0xFF; /* max P state */ 1972 *turbo_freq = (msr >> 24) & 0xFF; /* 4C turbo */ 1973 1974 /* The CPU may have less than 4 cores */ 1975 if (!*turbo_freq) 1976 *turbo_freq = msr & 0xFF; /* 1C turbo */ 1977 1978 return true; 1979 } 1980 1981 static bool intel_set_max_freq_ratio(void) 1982 { 1983 u64 base_freq, turbo_freq; 1984 u64 turbo_ratio; 1985 1986 if (slv_set_max_freq_ratio(&base_freq, &turbo_freq)) 1987 goto out; 1988 1989 if (x86_match_cpu(has_glm_turbo_ratio_limits) && 1990 skx_set_max_freq_ratio(&base_freq, &turbo_freq, 1)) 1991 goto out; 1992 1993 if (x86_match_cpu(has_knl_turbo_ratio_limits) && 1994 knl_set_max_freq_ratio(&base_freq, &turbo_freq, 1)) 1995 goto out; 1996 1997 if (x86_match_cpu(has_skx_turbo_ratio_limits) && 1998 skx_set_max_freq_ratio(&base_freq, &turbo_freq, 4)) 1999 goto out; 2000 2001 if (core_set_max_freq_ratio(&base_freq, &turbo_freq)) 2002 goto out; 2003 2004 return false; 2005 2006 out: 2007 /* 2008 * Some hypervisors advertise X86_FEATURE_APERFMPERF 2009 * but then fill all MSR's with zeroes. 2010 * Some CPUs have turbo boost but don't declare any turbo ratio 2011 * in MSR_TURBO_RATIO_LIMIT. 2012 */ 2013 if (!base_freq || !turbo_freq) { 2014 pr_debug("Couldn't determine cpu base or turbo frequency, necessary for scale-invariant accounting.\n"); 2015 return false; 2016 } 2017 2018 turbo_ratio = div_u64(turbo_freq * SCHED_CAPACITY_SCALE, base_freq); 2019 if (!turbo_ratio) { 2020 pr_debug("Non-zero turbo and base frequencies led to a 0 ratio.\n"); 2021 return false; 2022 } 2023 2024 arch_turbo_freq_ratio = turbo_ratio; 2025 arch_set_max_freq_ratio(turbo_disabled()); 2026 2027 return true; 2028 } 2029 2030 static void init_counter_refs(void) 2031 { 2032 u64 aperf, mperf; 2033 2034 rdmsrl(MSR_IA32_APERF, aperf); 2035 rdmsrl(MSR_IA32_MPERF, mperf); 2036 2037 this_cpu_write(arch_prev_aperf, aperf); 2038 this_cpu_write(arch_prev_mperf, mperf); 2039 } 2040 2041 static void init_freq_invariance(bool secondary) 2042 { 2043 bool ret = false; 2044 2045 if (!boot_cpu_has(X86_FEATURE_APERFMPERF)) 2046 return; 2047 2048 if (secondary) { 2049 if (static_branch_likely(&arch_scale_freq_key)) { 2050 init_counter_refs(); 2051 } 2052 return; 2053 } 2054 2055 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) 2056 ret = intel_set_max_freq_ratio(); 2057 2058 if (ret) { 2059 init_counter_refs(); 2060 static_branch_enable(&arch_scale_freq_key); 2061 } else { 2062 pr_debug("Couldn't determine max cpu frequency, necessary for scale-invariant accounting.\n"); 2063 } 2064 } 2065 2066 static void disable_freq_invariance_workfn(struct work_struct *work) 2067 { 2068 static_branch_disable(&arch_scale_freq_key); 2069 } 2070 2071 static DECLARE_WORK(disable_freq_invariance_work, 2072 disable_freq_invariance_workfn); 2073 2074 DEFINE_PER_CPU(unsigned long, arch_freq_scale) = SCHED_CAPACITY_SCALE; 2075 2076 void arch_scale_freq_tick(void) 2077 { 2078 u64 freq_scale = SCHED_CAPACITY_SCALE; 2079 u64 aperf, mperf; 2080 u64 acnt, mcnt; 2081 2082 if (!arch_scale_freq_invariant()) 2083 return; 2084 2085 rdmsrl(MSR_IA32_APERF, aperf); 2086 rdmsrl(MSR_IA32_MPERF, mperf); 2087 2088 acnt = aperf - this_cpu_read(arch_prev_aperf); 2089 mcnt = mperf - this_cpu_read(arch_prev_mperf); 2090 2091 this_cpu_write(arch_prev_aperf, aperf); 2092 this_cpu_write(arch_prev_mperf, mperf); 2093 2094 if (check_shl_overflow(acnt, 2*SCHED_CAPACITY_SHIFT, &acnt)) 2095 goto error; 2096 2097 if (check_mul_overflow(mcnt, arch_max_freq_ratio, &mcnt) || !mcnt) 2098 goto error; 2099 2100 freq_scale = div64_u64(acnt, mcnt); 2101 if (!freq_scale) 2102 goto error; 2103 2104 if (freq_scale > SCHED_CAPACITY_SCALE) 2105 freq_scale = SCHED_CAPACITY_SCALE; 2106 2107 this_cpu_write(arch_freq_scale, freq_scale); 2108 return; 2109 2110 error: 2111 pr_warn("Scheduler frequency invariance went wobbly, disabling!\n"); 2112 schedule_work(&disable_freq_invariance_work); 2113 } 2114 #else 2115 static inline void init_freq_invariance(bool secondary) 2116 { 2117 } 2118 #endif /* CONFIG_X86_64 */ 2119