1 /* 2 * x86 SMP booting functions 3 * 4 * (c) 1995 Alan Cox, Building #3 <alan@lxorguk.ukuu.org.uk> 5 * (c) 1998, 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com> 6 * Copyright 2001 Andi Kleen, SuSE Labs. 7 * 8 * Much of the core SMP work is based on previous work by Thomas Radke, to 9 * whom a great many thanks are extended. 10 * 11 * Thanks to Intel for making available several different Pentium, 12 * Pentium Pro and Pentium-II/Xeon MP machines. 13 * Original development of Linux SMP code supported by Caldera. 14 * 15 * This code is released under the GNU General Public License version 2 or 16 * later. 17 * 18 * Fixes 19 * Felix Koop : NR_CPUS used properly 20 * Jose Renau : Handle single CPU case. 21 * Alan Cox : By repeated request 8) - Total BogoMIPS report. 22 * Greg Wright : Fix for kernel stacks panic. 23 * Erich Boleyn : MP v1.4 and additional changes. 24 * Matthias Sattler : Changes for 2.1 kernel map. 25 * Michel Lespinasse : Changes for 2.1 kernel map. 26 * Michael Chastain : Change trampoline.S to gnu as. 27 * Alan Cox : Dumb bug: 'B' step PPro's are fine 28 * Ingo Molnar : Added APIC timers, based on code 29 * from Jose Renau 30 * Ingo Molnar : various cleanups and rewrites 31 * Tigran Aivazian : fixed "0.00 in /proc/uptime on SMP" bug. 32 * Maciej W. Rozycki : Bits for genuine 82489DX APICs 33 * Andi Kleen : Changed for SMP boot into long mode. 34 * Martin J. Bligh : Added support for multi-quad systems 35 * Dave Jones : Report invalid combinations of Athlon CPUs. 36 * Rusty Russell : Hacked into shape for new "hotplug" boot process. 37 * Andi Kleen : Converted to new state machine. 38 * Ashok Raj : CPU hotplug support 39 * Glauber Costa : i386 and x86_64 integration 40 */ 41 42 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 43 44 #include <linux/init.h> 45 #include <linux/smp.h> 46 #include <linux/export.h> 47 #include <linux/sched.h> 48 #include <linux/sched/topology.h> 49 #include <linux/sched/hotplug.h> 50 #include <linux/sched/task_stack.h> 51 #include <linux/percpu.h> 52 #include <linux/bootmem.h> 53 #include <linux/err.h> 54 #include <linux/nmi.h> 55 #include <linux/tboot.h> 56 #include <linux/stackprotector.h> 57 #include <linux/gfp.h> 58 #include <linux/cpuidle.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/pgtable.h> 68 #include <asm/tlbflush.h> 69 #include <asm/mtrr.h> 70 #include <asm/mwait.h> 71 #include <asm/apic.h> 72 #include <asm/io_apic.h> 73 #include <asm/fpu/internal.h> 74 #include <asm/setup.h> 75 #include <asm/uv/uv.h> 76 #include <linux/mc146818rtc.h> 77 #include <asm/i8259.h> 78 #include <asm/realmode.h> 79 #include <asm/misc.h> 80 #include <asm/qspinlock.h> 81 82 /* Number of siblings per CPU package */ 83 int smp_num_siblings = 1; 84 EXPORT_SYMBOL(smp_num_siblings); 85 86 /* Last level cache ID of each logical CPU */ 87 DEFINE_PER_CPU_READ_MOSTLY(u16, cpu_llc_id) = BAD_APICID; 88 89 /* representing HT siblings of each logical CPU */ 90 DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map); 91 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map); 92 93 /* representing HT and core siblings of each logical CPU */ 94 DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_map); 95 EXPORT_PER_CPU_SYMBOL(cpu_core_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; 107 108 /* Maximum number of SMT threads on any online core */ 109 int __max_smt_threads __read_mostly; 110 111 /* Flag to indicate if a complete sched domain rebuild is required */ 112 bool x86_topology_update; 113 114 int arch_update_cpu_topology(void) 115 { 116 int retval = x86_topology_update; 117 118 x86_topology_update = false; 119 return retval; 120 } 121 122 static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip) 123 { 124 unsigned long flags; 125 126 spin_lock_irqsave(&rtc_lock, flags); 127 CMOS_WRITE(0xa, 0xf); 128 spin_unlock_irqrestore(&rtc_lock, flags); 129 local_flush_tlb(); 130 pr_debug("1.\n"); 131 *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_HIGH)) = 132 start_eip >> 4; 133 pr_debug("2.\n"); 134 *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = 135 start_eip & 0xf; 136 pr_debug("3.\n"); 137 } 138 139 static inline void smpboot_restore_warm_reset_vector(void) 140 { 141 unsigned long flags; 142 143 /* 144 * Install writable page 0 entry to set BIOS data area. 145 */ 146 local_flush_tlb(); 147 148 /* 149 * Paranoid: Set warm reset code and vector here back 150 * to default values. 151 */ 152 spin_lock_irqsave(&rtc_lock, flags); 153 CMOS_WRITE(0, 0xf); 154 spin_unlock_irqrestore(&rtc_lock, flags); 155 156 *((volatile u32 *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = 0; 157 } 158 159 /* 160 * Report back to the Boot Processor during boot time or to the caller processor 161 * during CPU online. 162 */ 163 static void smp_callin(void) 164 { 165 int cpuid, phys_id; 166 167 /* 168 * If waken up by an INIT in an 82489DX configuration 169 * cpu_callout_mask guarantees we don't get here before 170 * an INIT_deassert IPI reaches our local APIC, so it is 171 * now safe to touch our local APIC. 172 */ 173 cpuid = smp_processor_id(); 174 175 /* 176 * (This works even if the APIC is not enabled.) 177 */ 178 phys_id = read_apic_id(); 179 180 /* 181 * the boot CPU has finished the init stage and is spinning 182 * on callin_map until we finish. We are free to set up this 183 * CPU, first the APIC. (this is probably redundant on most 184 * boards) 185 */ 186 apic_ap_setup(); 187 188 /* 189 * Save our processor parameters. Note: this information 190 * is needed for clock calibration. 191 */ 192 smp_store_cpu_info(cpuid); 193 194 /* 195 * The topology information must be up to date before 196 * calibrate_delay() and notify_cpu_starting(). 197 */ 198 set_cpu_sibling_map(raw_smp_processor_id()); 199 200 /* 201 * Get our bogomips. 202 * Update loops_per_jiffy in cpu_data. Previous call to 203 * smp_store_cpu_info() stored a value that is close but not as 204 * accurate as the value just calculated. 205 */ 206 calibrate_delay(); 207 cpu_data(cpuid).loops_per_jiffy = loops_per_jiffy; 208 pr_debug("Stack at about %p\n", &cpuid); 209 210 wmb(); 211 212 notify_cpu_starting(cpuid); 213 214 /* 215 * Allow the master to continue. 216 */ 217 cpumask_set_cpu(cpuid, cpu_callin_mask); 218 } 219 220 static int cpu0_logical_apicid; 221 static int enable_start_cpu0; 222 /* 223 * Activate a secondary processor. 224 */ 225 static void notrace start_secondary(void *unused) 226 { 227 /* 228 * Don't put *anything* except direct CPU state initialization 229 * before cpu_init(), SMP booting is too fragile that we want to 230 * limit the things done here to the most necessary things. 231 */ 232 if (boot_cpu_has(X86_FEATURE_PCID)) 233 __write_cr4(__read_cr4() | X86_CR4_PCIDE); 234 235 #ifdef CONFIG_X86_32 236 /* switch away from the initial page table */ 237 load_cr3(swapper_pg_dir); 238 __flush_tlb_all(); 239 #endif 240 load_current_idt(); 241 cpu_init(); 242 x86_cpuinit.early_percpu_clock_init(); 243 preempt_disable(); 244 smp_callin(); 245 246 enable_start_cpu0 = 0; 247 248 /* otherwise gcc will move up smp_processor_id before the cpu_init */ 249 barrier(); 250 /* 251 * Check TSC synchronization with the boot CPU: 252 */ 253 check_tsc_sync_target(); 254 255 /* 256 * Lock vector_lock, set CPU online and bring the vector 257 * allocator online. Online must be set with vector_lock held 258 * to prevent a concurrent irq setup/teardown from seeing a 259 * half valid vector space. 260 */ 261 lock_vector_lock(); 262 set_cpu_online(smp_processor_id(), true); 263 lapic_online(); 264 unlock_vector_lock(); 265 cpu_set_state_online(smp_processor_id()); 266 x86_platform.nmi_init(); 267 268 /* enable local interrupts */ 269 local_irq_enable(); 270 271 /* to prevent fake stack check failure in clock setup */ 272 boot_init_stack_canary(); 273 274 x86_cpuinit.setup_percpu_clockev(); 275 276 wmb(); 277 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); 278 } 279 280 /** 281 * topology_phys_to_logical_pkg - Map a physical package id to a logical 282 * 283 * Returns logical package id or -1 if not found 284 */ 285 int topology_phys_to_logical_pkg(unsigned int phys_pkg) 286 { 287 int cpu; 288 289 for_each_possible_cpu(cpu) { 290 struct cpuinfo_x86 *c = &cpu_data(cpu); 291 292 if (c->initialized && c->phys_proc_id == phys_pkg) 293 return c->logical_proc_id; 294 } 295 return -1; 296 } 297 EXPORT_SYMBOL(topology_phys_to_logical_pkg); 298 299 /** 300 * topology_update_package_map - Update the physical to logical package map 301 * @pkg: The physical package id as retrieved via CPUID 302 * @cpu: The cpu for which this is updated 303 */ 304 int topology_update_package_map(unsigned int pkg, unsigned int cpu) 305 { 306 int new; 307 308 /* Already available somewhere? */ 309 new = topology_phys_to_logical_pkg(pkg); 310 if (new >= 0) 311 goto found; 312 313 new = logical_packages++; 314 if (new != pkg) { 315 pr_info("CPU %u Converting physical %u to logical package %u\n", 316 cpu, pkg, new); 317 } 318 found: 319 cpu_data(cpu).logical_proc_id = new; 320 return 0; 321 } 322 323 void __init smp_store_boot_cpu_info(void) 324 { 325 int id = 0; /* CPU 0 */ 326 struct cpuinfo_x86 *c = &cpu_data(id); 327 328 *c = boot_cpu_data; 329 c->cpu_index = id; 330 topology_update_package_map(c->phys_proc_id, id); 331 c->initialized = true; 332 } 333 334 /* 335 * The bootstrap kernel entry code has set these up. Save them for 336 * a given CPU 337 */ 338 void smp_store_cpu_info(int id) 339 { 340 struct cpuinfo_x86 *c = &cpu_data(id); 341 342 /* Copy boot_cpu_data only on the first bringup */ 343 if (!c->initialized) 344 *c = boot_cpu_data; 345 c->cpu_index = id; 346 /* 347 * During boot time, CPU0 has this setup already. Save the info when 348 * bringing up AP or offlined CPU0. 349 */ 350 identify_secondary_cpu(c); 351 c->initialized = true; 352 } 353 354 static bool 355 topology_same_node(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) 356 { 357 int cpu1 = c->cpu_index, cpu2 = o->cpu_index; 358 359 return (cpu_to_node(cpu1) == cpu_to_node(cpu2)); 360 } 361 362 static bool 363 topology_sane(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o, const char *name) 364 { 365 int cpu1 = c->cpu_index, cpu2 = o->cpu_index; 366 367 return !WARN_ONCE(!topology_same_node(c, o), 368 "sched: CPU #%d's %s-sibling CPU #%d is not on the same node! " 369 "[node: %d != %d]. Ignoring dependency.\n", 370 cpu1, name, cpu2, cpu_to_node(cpu1), cpu_to_node(cpu2)); 371 } 372 373 #define link_mask(mfunc, c1, c2) \ 374 do { \ 375 cpumask_set_cpu((c1), mfunc(c2)); \ 376 cpumask_set_cpu((c2), mfunc(c1)); \ 377 } while (0) 378 379 static bool match_smt(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) 380 { 381 if (boot_cpu_has(X86_FEATURE_TOPOEXT)) { 382 int cpu1 = c->cpu_index, cpu2 = o->cpu_index; 383 384 if (c->phys_proc_id == o->phys_proc_id && 385 per_cpu(cpu_llc_id, cpu1) == per_cpu(cpu_llc_id, cpu2)) { 386 if (c->cpu_core_id == o->cpu_core_id) 387 return topology_sane(c, o, "smt"); 388 389 if ((c->cu_id != 0xff) && 390 (o->cu_id != 0xff) && 391 (c->cu_id == o->cu_id)) 392 return topology_sane(c, o, "smt"); 393 } 394 395 } else if (c->phys_proc_id == o->phys_proc_id && 396 c->cpu_core_id == o->cpu_core_id) { 397 return topology_sane(c, o, "smt"); 398 } 399 400 return false; 401 } 402 403 static bool match_llc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) 404 { 405 int cpu1 = c->cpu_index, cpu2 = o->cpu_index; 406 407 if (per_cpu(cpu_llc_id, cpu1) != BAD_APICID && 408 per_cpu(cpu_llc_id, cpu1) == per_cpu(cpu_llc_id, cpu2)) 409 return topology_sane(c, o, "llc"); 410 411 return false; 412 } 413 414 /* 415 * Unlike the other levels, we do not enforce keeping a 416 * multicore group inside a NUMA node. If this happens, we will 417 * discard the MC level of the topology later. 418 */ 419 static bool match_die(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) 420 { 421 if (c->phys_proc_id == o->phys_proc_id) 422 return true; 423 return false; 424 } 425 426 #if defined(CONFIG_SCHED_SMT) || defined(CONFIG_SCHED_MC) 427 static inline int x86_sched_itmt_flags(void) 428 { 429 return sysctl_sched_itmt_enabled ? SD_ASYM_PACKING : 0; 430 } 431 432 #ifdef CONFIG_SCHED_MC 433 static int x86_core_flags(void) 434 { 435 return cpu_core_flags() | x86_sched_itmt_flags(); 436 } 437 #endif 438 #ifdef CONFIG_SCHED_SMT 439 static int x86_smt_flags(void) 440 { 441 return cpu_smt_flags() | x86_sched_itmt_flags(); 442 } 443 #endif 444 #endif 445 446 static struct sched_domain_topology_level x86_numa_in_package_topology[] = { 447 #ifdef CONFIG_SCHED_SMT 448 { cpu_smt_mask, x86_smt_flags, SD_INIT_NAME(SMT) }, 449 #endif 450 #ifdef CONFIG_SCHED_MC 451 { cpu_coregroup_mask, x86_core_flags, SD_INIT_NAME(MC) }, 452 #endif 453 { NULL, }, 454 }; 455 456 static struct sched_domain_topology_level x86_topology[] = { 457 #ifdef CONFIG_SCHED_SMT 458 { cpu_smt_mask, x86_smt_flags, SD_INIT_NAME(SMT) }, 459 #endif 460 #ifdef CONFIG_SCHED_MC 461 { cpu_coregroup_mask, x86_core_flags, SD_INIT_NAME(MC) }, 462 #endif 463 { cpu_cpu_mask, SD_INIT_NAME(DIE) }, 464 { NULL, }, 465 }; 466 467 /* 468 * Set if a package/die has multiple NUMA nodes inside. 469 * AMD Magny-Cours and Intel Cluster-on-Die have this. 470 */ 471 static bool x86_has_numa_in_package; 472 473 void set_cpu_sibling_map(int cpu) 474 { 475 bool has_smt = smp_num_siblings > 1; 476 bool has_mp = has_smt || boot_cpu_data.x86_max_cores > 1; 477 struct cpuinfo_x86 *c = &cpu_data(cpu); 478 struct cpuinfo_x86 *o; 479 int i, threads; 480 481 cpumask_set_cpu(cpu, cpu_sibling_setup_mask); 482 483 if (!has_mp) { 484 cpumask_set_cpu(cpu, topology_sibling_cpumask(cpu)); 485 cpumask_set_cpu(cpu, cpu_llc_shared_mask(cpu)); 486 cpumask_set_cpu(cpu, topology_core_cpumask(cpu)); 487 c->booted_cores = 1; 488 return; 489 } 490 491 for_each_cpu(i, cpu_sibling_setup_mask) { 492 o = &cpu_data(i); 493 494 if ((i == cpu) || (has_smt && match_smt(c, o))) 495 link_mask(topology_sibling_cpumask, cpu, i); 496 497 if ((i == cpu) || (has_mp && match_llc(c, o))) 498 link_mask(cpu_llc_shared_mask, cpu, i); 499 500 } 501 502 /* 503 * This needs a separate iteration over the cpus because we rely on all 504 * topology_sibling_cpumask links to be set-up. 505 */ 506 for_each_cpu(i, cpu_sibling_setup_mask) { 507 o = &cpu_data(i); 508 509 if ((i == cpu) || (has_mp && match_die(c, o))) { 510 link_mask(topology_core_cpumask, cpu, i); 511 512 /* 513 * Does this new cpu bringup a new core? 514 */ 515 if (cpumask_weight( 516 topology_sibling_cpumask(cpu)) == 1) { 517 /* 518 * for each core in package, increment 519 * the booted_cores for this new cpu 520 */ 521 if (cpumask_first( 522 topology_sibling_cpumask(i)) == i) 523 c->booted_cores++; 524 /* 525 * increment the core count for all 526 * the other cpus in this package 527 */ 528 if (i != cpu) 529 cpu_data(i).booted_cores++; 530 } else if (i != cpu && !c->booted_cores) 531 c->booted_cores = cpu_data(i).booted_cores; 532 } 533 if (match_die(c, o) && !topology_same_node(c, o)) 534 x86_has_numa_in_package = true; 535 } 536 537 threads = cpumask_weight(topology_sibling_cpumask(cpu)); 538 if (threads > __max_smt_threads) 539 __max_smt_threads = threads; 540 } 541 542 /* maps the cpu to the sched domain representing multi-core */ 543 const struct cpumask *cpu_coregroup_mask(int cpu) 544 { 545 return cpu_llc_shared_mask(cpu); 546 } 547 548 static void impress_friends(void) 549 { 550 int cpu; 551 unsigned long bogosum = 0; 552 /* 553 * Allow the user to impress friends. 554 */ 555 pr_debug("Before bogomips\n"); 556 for_each_possible_cpu(cpu) 557 if (cpumask_test_cpu(cpu, cpu_callout_mask)) 558 bogosum += cpu_data(cpu).loops_per_jiffy; 559 pr_info("Total of %d processors activated (%lu.%02lu BogoMIPS)\n", 560 num_online_cpus(), 561 bogosum/(500000/HZ), 562 (bogosum/(5000/HZ))%100); 563 564 pr_debug("Before bogocount - setting activated=1\n"); 565 } 566 567 void __inquire_remote_apic(int apicid) 568 { 569 unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 }; 570 const char * const names[] = { "ID", "VERSION", "SPIV" }; 571 int timeout; 572 u32 status; 573 574 pr_info("Inquiring remote APIC 0x%x...\n", apicid); 575 576 for (i = 0; i < ARRAY_SIZE(regs); i++) { 577 pr_info("... APIC 0x%x %s: ", apicid, names[i]); 578 579 /* 580 * Wait for idle. 581 */ 582 status = safe_apic_wait_icr_idle(); 583 if (status) 584 pr_cont("a previous APIC delivery may have failed\n"); 585 586 apic_icr_write(APIC_DM_REMRD | regs[i], apicid); 587 588 timeout = 0; 589 do { 590 udelay(100); 591 status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK; 592 } while (status == APIC_ICR_RR_INPROG && timeout++ < 1000); 593 594 switch (status) { 595 case APIC_ICR_RR_VALID: 596 status = apic_read(APIC_RRR); 597 pr_cont("%08x\n", status); 598 break; 599 default: 600 pr_cont("failed\n"); 601 } 602 } 603 } 604 605 /* 606 * The Multiprocessor Specification 1.4 (1997) example code suggests 607 * that there should be a 10ms delay between the BSP asserting INIT 608 * and de-asserting INIT, when starting a remote processor. 609 * But that slows boot and resume on modern processors, which include 610 * many cores and don't require that delay. 611 * 612 * Cmdline "init_cpu_udelay=" is available to over-ride this delay. 613 * Modern processor families are quirked to remove the delay entirely. 614 */ 615 #define UDELAY_10MS_DEFAULT 10000 616 617 static unsigned int init_udelay = UINT_MAX; 618 619 static int __init cpu_init_udelay(char *str) 620 { 621 get_option(&str, &init_udelay); 622 623 return 0; 624 } 625 early_param("cpu_init_udelay", cpu_init_udelay); 626 627 static void __init smp_quirk_init_udelay(void) 628 { 629 /* if cmdline changed it from default, leave it alone */ 630 if (init_udelay != UINT_MAX) 631 return; 632 633 /* if modern processor, use no delay */ 634 if (((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && (boot_cpu_data.x86 == 6)) || 635 ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && (boot_cpu_data.x86 >= 0xF))) { 636 init_udelay = 0; 637 return; 638 } 639 /* else, use legacy delay */ 640 init_udelay = UDELAY_10MS_DEFAULT; 641 } 642 643 /* 644 * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal 645 * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this 646 * won't ... remember to clear down the APIC, etc later. 647 */ 648 int 649 wakeup_secondary_cpu_via_nmi(int apicid, unsigned long start_eip) 650 { 651 unsigned long send_status, accept_status = 0; 652 int maxlvt; 653 654 /* Target chip */ 655 /* Boot on the stack */ 656 /* Kick the second */ 657 apic_icr_write(APIC_DM_NMI | apic->dest_logical, apicid); 658 659 pr_debug("Waiting for send to finish...\n"); 660 send_status = safe_apic_wait_icr_idle(); 661 662 /* 663 * Give the other CPU some time to accept the IPI. 664 */ 665 udelay(200); 666 if (APIC_INTEGRATED(boot_cpu_apic_version)) { 667 maxlvt = lapic_get_maxlvt(); 668 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ 669 apic_write(APIC_ESR, 0); 670 accept_status = (apic_read(APIC_ESR) & 0xEF); 671 } 672 pr_debug("NMI sent\n"); 673 674 if (send_status) 675 pr_err("APIC never delivered???\n"); 676 if (accept_status) 677 pr_err("APIC delivery error (%lx)\n", accept_status); 678 679 return (send_status | accept_status); 680 } 681 682 static int 683 wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip) 684 { 685 unsigned long send_status = 0, accept_status = 0; 686 int maxlvt, num_starts, j; 687 688 maxlvt = lapic_get_maxlvt(); 689 690 /* 691 * Be paranoid about clearing APIC errors. 692 */ 693 if (APIC_INTEGRATED(boot_cpu_apic_version)) { 694 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ 695 apic_write(APIC_ESR, 0); 696 apic_read(APIC_ESR); 697 } 698 699 pr_debug("Asserting INIT\n"); 700 701 /* 702 * Turn INIT on target chip 703 */ 704 /* 705 * Send IPI 706 */ 707 apic_icr_write(APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT, 708 phys_apicid); 709 710 pr_debug("Waiting for send to finish...\n"); 711 send_status = safe_apic_wait_icr_idle(); 712 713 udelay(init_udelay); 714 715 pr_debug("Deasserting INIT\n"); 716 717 /* Target chip */ 718 /* Send IPI */ 719 apic_icr_write(APIC_INT_LEVELTRIG | APIC_DM_INIT, phys_apicid); 720 721 pr_debug("Waiting for send to finish...\n"); 722 send_status = safe_apic_wait_icr_idle(); 723 724 mb(); 725 726 /* 727 * Should we send STARTUP IPIs ? 728 * 729 * Determine this based on the APIC version. 730 * If we don't have an integrated APIC, don't send the STARTUP IPIs. 731 */ 732 if (APIC_INTEGRATED(boot_cpu_apic_version)) 733 num_starts = 2; 734 else 735 num_starts = 0; 736 737 /* 738 * Run STARTUP IPI loop. 739 */ 740 pr_debug("#startup loops: %d\n", num_starts); 741 742 for (j = 1; j <= num_starts; j++) { 743 pr_debug("Sending STARTUP #%d\n", j); 744 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ 745 apic_write(APIC_ESR, 0); 746 apic_read(APIC_ESR); 747 pr_debug("After apic_write\n"); 748 749 /* 750 * STARTUP IPI 751 */ 752 753 /* Target chip */ 754 /* Boot on the stack */ 755 /* Kick the second */ 756 apic_icr_write(APIC_DM_STARTUP | (start_eip >> 12), 757 phys_apicid); 758 759 /* 760 * Give the other CPU some time to accept the IPI. 761 */ 762 if (init_udelay == 0) 763 udelay(10); 764 else 765 udelay(300); 766 767 pr_debug("Startup point 1\n"); 768 769 pr_debug("Waiting for send to finish...\n"); 770 send_status = safe_apic_wait_icr_idle(); 771 772 /* 773 * Give the other CPU some time to accept the IPI. 774 */ 775 if (init_udelay == 0) 776 udelay(10); 777 else 778 udelay(200); 779 780 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ 781 apic_write(APIC_ESR, 0); 782 accept_status = (apic_read(APIC_ESR) & 0xEF); 783 if (send_status || accept_status) 784 break; 785 } 786 pr_debug("After Startup\n"); 787 788 if (send_status) 789 pr_err("APIC never delivered???\n"); 790 if (accept_status) 791 pr_err("APIC delivery error (%lx)\n", accept_status); 792 793 return (send_status | accept_status); 794 } 795 796 /* reduce the number of lines printed when booting a large cpu count system */ 797 static void announce_cpu(int cpu, int apicid) 798 { 799 static int current_node = -1; 800 int node = early_cpu_to_node(cpu); 801 static int width, node_width; 802 803 if (!width) 804 width = num_digits(num_possible_cpus()) + 1; /* + '#' sign */ 805 806 if (!node_width) 807 node_width = num_digits(num_possible_nodes()) + 1; /* + '#' */ 808 809 if (cpu == 1) 810 printk(KERN_INFO "x86: Booting SMP configuration:\n"); 811 812 if (system_state < SYSTEM_RUNNING) { 813 if (node != current_node) { 814 if (current_node > (-1)) 815 pr_cont("\n"); 816 current_node = node; 817 818 printk(KERN_INFO ".... node %*s#%d, CPUs: ", 819 node_width - num_digits(node), " ", node); 820 } 821 822 /* Add padding for the BSP */ 823 if (cpu == 1) 824 pr_cont("%*s", width + 1, " "); 825 826 pr_cont("%*s#%d", width - num_digits(cpu), " ", cpu); 827 828 } else 829 pr_info("Booting Node %d Processor %d APIC 0x%x\n", 830 node, cpu, apicid); 831 } 832 833 static int wakeup_cpu0_nmi(unsigned int cmd, struct pt_regs *regs) 834 { 835 int cpu; 836 837 cpu = smp_processor_id(); 838 if (cpu == 0 && !cpu_online(cpu) && enable_start_cpu0) 839 return NMI_HANDLED; 840 841 return NMI_DONE; 842 } 843 844 /* 845 * Wake up AP by INIT, INIT, STARTUP sequence. 846 * 847 * Instead of waiting for STARTUP after INITs, BSP will execute the BIOS 848 * boot-strap code which is not a desired behavior for waking up BSP. To 849 * void the boot-strap code, wake up CPU0 by NMI instead. 850 * 851 * This works to wake up soft offlined CPU0 only. If CPU0 is hard offlined 852 * (i.e. physically hot removed and then hot added), NMI won't wake it up. 853 * We'll change this code in the future to wake up hard offlined CPU0 if 854 * real platform and request are available. 855 */ 856 static int 857 wakeup_cpu_via_init_nmi(int cpu, unsigned long start_ip, int apicid, 858 int *cpu0_nmi_registered) 859 { 860 int id; 861 int boot_error; 862 863 preempt_disable(); 864 865 /* 866 * Wake up AP by INIT, INIT, STARTUP sequence. 867 */ 868 if (cpu) { 869 boot_error = wakeup_secondary_cpu_via_init(apicid, start_ip); 870 goto out; 871 } 872 873 /* 874 * Wake up BSP by nmi. 875 * 876 * Register a NMI handler to help wake up CPU0. 877 */ 878 boot_error = register_nmi_handler(NMI_LOCAL, 879 wakeup_cpu0_nmi, 0, "wake_cpu0"); 880 881 if (!boot_error) { 882 enable_start_cpu0 = 1; 883 *cpu0_nmi_registered = 1; 884 if (apic->dest_logical == APIC_DEST_LOGICAL) 885 id = cpu0_logical_apicid; 886 else 887 id = apicid; 888 boot_error = wakeup_secondary_cpu_via_nmi(id, start_ip); 889 } 890 891 out: 892 preempt_enable(); 893 894 return boot_error; 895 } 896 897 void common_cpu_up(unsigned int cpu, struct task_struct *idle) 898 { 899 /* Just in case we booted with a single CPU. */ 900 alternatives_enable_smp(); 901 902 per_cpu(current_task, cpu) = idle; 903 904 #ifdef CONFIG_X86_32 905 /* Stack for startup_32 can be just as for start_secondary onwards */ 906 irq_ctx_init(cpu); 907 per_cpu(cpu_current_top_of_stack, cpu) = task_top_of_stack(idle); 908 #else 909 initial_gs = per_cpu_offset(cpu); 910 #endif 911 } 912 913 /* 914 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad 915 * (ie clustered apic addressing mode), this is a LOGICAL apic ID. 916 * Returns zero if CPU booted OK, else error code from 917 * ->wakeup_secondary_cpu. 918 */ 919 static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle, 920 int *cpu0_nmi_registered) 921 { 922 volatile u32 *trampoline_status = 923 (volatile u32 *) __va(real_mode_header->trampoline_status); 924 /* start_ip had better be page-aligned! */ 925 unsigned long start_ip = real_mode_header->trampoline_start; 926 927 unsigned long boot_error = 0; 928 unsigned long timeout; 929 930 idle->thread.sp = (unsigned long)task_pt_regs(idle); 931 early_gdt_descr.address = (unsigned long)get_cpu_gdt_rw(cpu); 932 initial_code = (unsigned long)start_secondary; 933 initial_stack = idle->thread.sp; 934 935 /* 936 * Enable the espfix hack for this CPU 937 */ 938 #ifdef CONFIG_X86_ESPFIX64 939 init_espfix_ap(cpu); 940 #endif 941 942 /* So we see what's up */ 943 announce_cpu(cpu, apicid); 944 945 /* 946 * This grunge runs the startup process for 947 * the targeted processor. 948 */ 949 950 if (get_uv_system_type() != UV_NON_UNIQUE_APIC) { 951 952 pr_debug("Setting warm reset code and vector.\n"); 953 954 smpboot_setup_warm_reset_vector(start_ip); 955 /* 956 * Be paranoid about clearing APIC errors. 957 */ 958 if (APIC_INTEGRATED(boot_cpu_apic_version)) { 959 apic_write(APIC_ESR, 0); 960 apic_read(APIC_ESR); 961 } 962 } 963 964 /* 965 * AP might wait on cpu_callout_mask in cpu_init() with 966 * cpu_initialized_mask set if previous attempt to online 967 * it timed-out. Clear cpu_initialized_mask so that after 968 * INIT/SIPI it could start with a clean state. 969 */ 970 cpumask_clear_cpu(cpu, cpu_initialized_mask); 971 smp_mb(); 972 973 /* 974 * Wake up a CPU in difference cases: 975 * - Use the method in the APIC driver if it's defined 976 * Otherwise, 977 * - Use an INIT boot APIC message for APs or NMI for BSP. 978 */ 979 if (apic->wakeup_secondary_cpu) 980 boot_error = apic->wakeup_secondary_cpu(apicid, start_ip); 981 else 982 boot_error = wakeup_cpu_via_init_nmi(cpu, start_ip, apicid, 983 cpu0_nmi_registered); 984 985 if (!boot_error) { 986 /* 987 * Wait 10s total for first sign of life from AP 988 */ 989 boot_error = -1; 990 timeout = jiffies + 10*HZ; 991 while (time_before(jiffies, timeout)) { 992 if (cpumask_test_cpu(cpu, cpu_initialized_mask)) { 993 /* 994 * Tell AP to proceed with initialization 995 */ 996 cpumask_set_cpu(cpu, cpu_callout_mask); 997 boot_error = 0; 998 break; 999 } 1000 schedule(); 1001 } 1002 } 1003 1004 if (!boot_error) { 1005 /* 1006 * Wait till AP completes initial initialization 1007 */ 1008 while (!cpumask_test_cpu(cpu, cpu_callin_mask)) { 1009 /* 1010 * Allow other tasks to run while we wait for the 1011 * AP to come online. This also gives a chance 1012 * for the MTRR work(triggered by the AP coming online) 1013 * to be completed in the stop machine context. 1014 */ 1015 schedule(); 1016 } 1017 } 1018 1019 /* mark "stuck" area as not stuck */ 1020 *trampoline_status = 0; 1021 1022 if (get_uv_system_type() != UV_NON_UNIQUE_APIC) { 1023 /* 1024 * Cleanup possible dangling ends... 1025 */ 1026 smpboot_restore_warm_reset_vector(); 1027 } 1028 1029 return boot_error; 1030 } 1031 1032 int native_cpu_up(unsigned int cpu, struct task_struct *tidle) 1033 { 1034 int apicid = apic->cpu_present_to_apicid(cpu); 1035 int cpu0_nmi_registered = 0; 1036 unsigned long flags; 1037 int err, ret = 0; 1038 1039 lockdep_assert_irqs_enabled(); 1040 1041 pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu); 1042 1043 if (apicid == BAD_APICID || 1044 !physid_isset(apicid, phys_cpu_present_map) || 1045 !apic->apic_id_valid(apicid)) { 1046 pr_err("%s: bad cpu %d\n", __func__, cpu); 1047 return -EINVAL; 1048 } 1049 1050 /* 1051 * Already booted CPU? 1052 */ 1053 if (cpumask_test_cpu(cpu, cpu_callin_mask)) { 1054 pr_debug("do_boot_cpu %d Already started\n", cpu); 1055 return -ENOSYS; 1056 } 1057 1058 /* 1059 * Save current MTRR state in case it was changed since early boot 1060 * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync: 1061 */ 1062 mtrr_save_state(); 1063 1064 /* x86 CPUs take themselves offline, so delayed offline is OK. */ 1065 err = cpu_check_up_prepare(cpu); 1066 if (err && err != -EBUSY) 1067 return err; 1068 1069 /* the FPU context is blank, nobody can own it */ 1070 per_cpu(fpu_fpregs_owner_ctx, cpu) = NULL; 1071 1072 common_cpu_up(cpu, tidle); 1073 1074 err = do_boot_cpu(apicid, cpu, tidle, &cpu0_nmi_registered); 1075 if (err) { 1076 pr_err("do_boot_cpu failed(%d) to wakeup CPU#%u\n", err, cpu); 1077 ret = -EIO; 1078 goto unreg_nmi; 1079 } 1080 1081 /* 1082 * Check TSC synchronization with the AP (keep irqs disabled 1083 * while doing so): 1084 */ 1085 local_irq_save(flags); 1086 check_tsc_sync_source(cpu); 1087 local_irq_restore(flags); 1088 1089 while (!cpu_online(cpu)) { 1090 cpu_relax(); 1091 touch_nmi_watchdog(); 1092 } 1093 1094 unreg_nmi: 1095 /* 1096 * Clean up the nmi handler. Do this after the callin and callout sync 1097 * to avoid impact of possible long unregister time. 1098 */ 1099 if (cpu0_nmi_registered) 1100 unregister_nmi_handler(NMI_LOCAL, "wake_cpu0"); 1101 1102 return ret; 1103 } 1104 1105 /** 1106 * arch_disable_smp_support() - disables SMP support for x86 at runtime 1107 */ 1108 void arch_disable_smp_support(void) 1109 { 1110 disable_ioapic_support(); 1111 } 1112 1113 /* 1114 * Fall back to non SMP mode after errors. 1115 * 1116 * RED-PEN audit/test this more. I bet there is more state messed up here. 1117 */ 1118 static __init void disable_smp(void) 1119 { 1120 pr_info("SMP disabled\n"); 1121 1122 disable_ioapic_support(); 1123 1124 init_cpu_present(cpumask_of(0)); 1125 init_cpu_possible(cpumask_of(0)); 1126 1127 if (smp_found_config) 1128 physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map); 1129 else 1130 physid_set_mask_of_physid(0, &phys_cpu_present_map); 1131 cpumask_set_cpu(0, topology_sibling_cpumask(0)); 1132 cpumask_set_cpu(0, topology_core_cpumask(0)); 1133 } 1134 1135 /* 1136 * Various sanity checks. 1137 */ 1138 static void __init smp_sanity_check(void) 1139 { 1140 preempt_disable(); 1141 1142 #if !defined(CONFIG_X86_BIGSMP) && defined(CONFIG_X86_32) 1143 if (def_to_bigsmp && nr_cpu_ids > 8) { 1144 unsigned int cpu; 1145 unsigned nr; 1146 1147 pr_warn("More than 8 CPUs detected - skipping them\n" 1148 "Use CONFIG_X86_BIGSMP\n"); 1149 1150 nr = 0; 1151 for_each_present_cpu(cpu) { 1152 if (nr >= 8) 1153 set_cpu_present(cpu, false); 1154 nr++; 1155 } 1156 1157 nr = 0; 1158 for_each_possible_cpu(cpu) { 1159 if (nr >= 8) 1160 set_cpu_possible(cpu, false); 1161 nr++; 1162 } 1163 1164 nr_cpu_ids = 8; 1165 } 1166 #endif 1167 1168 if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) { 1169 pr_warn("weird, boot CPU (#%d) not listed by the BIOS\n", 1170 hard_smp_processor_id()); 1171 1172 physid_set(hard_smp_processor_id(), phys_cpu_present_map); 1173 } 1174 1175 /* 1176 * Should not be necessary because the MP table should list the boot 1177 * CPU too, but we do it for the sake of robustness anyway. 1178 */ 1179 if (!apic->check_phys_apicid_present(boot_cpu_physical_apicid)) { 1180 pr_notice("weird, boot CPU (#%d) not listed by the BIOS\n", 1181 boot_cpu_physical_apicid); 1182 physid_set(hard_smp_processor_id(), phys_cpu_present_map); 1183 } 1184 preempt_enable(); 1185 } 1186 1187 static void __init smp_cpu_index_default(void) 1188 { 1189 int i; 1190 struct cpuinfo_x86 *c; 1191 1192 for_each_possible_cpu(i) { 1193 c = &cpu_data(i); 1194 /* mark all to hotplug */ 1195 c->cpu_index = nr_cpu_ids; 1196 } 1197 } 1198 1199 static void __init smp_get_logical_apicid(void) 1200 { 1201 if (x2apic_mode) 1202 cpu0_logical_apicid = apic_read(APIC_LDR); 1203 else 1204 cpu0_logical_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR)); 1205 } 1206 1207 /* 1208 * Prepare for SMP bootup. 1209 * @max_cpus: configured maximum number of CPUs, It is a legacy parameter 1210 * for common interface support. 1211 */ 1212 void __init native_smp_prepare_cpus(unsigned int max_cpus) 1213 { 1214 unsigned int i; 1215 1216 smp_cpu_index_default(); 1217 1218 /* 1219 * Setup boot CPU information 1220 */ 1221 smp_store_boot_cpu_info(); /* Final full version of the data */ 1222 cpumask_copy(cpu_callin_mask, cpumask_of(0)); 1223 mb(); 1224 1225 for_each_possible_cpu(i) { 1226 zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL); 1227 zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL); 1228 zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL); 1229 } 1230 1231 /* 1232 * Set 'default' x86 topology, this matches default_topology() in that 1233 * it has NUMA nodes as a topology level. See also 1234 * native_smp_cpus_done(). 1235 * 1236 * Must be done before set_cpus_sibling_map() is ran. 1237 */ 1238 set_sched_topology(x86_topology); 1239 1240 set_cpu_sibling_map(0); 1241 1242 smp_sanity_check(); 1243 1244 switch (apic_intr_mode) { 1245 case APIC_PIC: 1246 case APIC_VIRTUAL_WIRE_NO_CONFIG: 1247 disable_smp(); 1248 return; 1249 case APIC_SYMMETRIC_IO_NO_ROUTING: 1250 disable_smp(); 1251 /* Setup local timer */ 1252 x86_init.timers.setup_percpu_clockev(); 1253 return; 1254 case APIC_VIRTUAL_WIRE: 1255 case APIC_SYMMETRIC_IO: 1256 break; 1257 } 1258 1259 /* Setup local timer */ 1260 x86_init.timers.setup_percpu_clockev(); 1261 1262 smp_get_logical_apicid(); 1263 1264 pr_info("CPU0: "); 1265 print_cpu_info(&cpu_data(0)); 1266 1267 native_pv_lock_init(); 1268 1269 uv_system_init(); 1270 1271 set_mtrr_aps_delayed_init(); 1272 1273 smp_quirk_init_udelay(); 1274 } 1275 1276 void arch_enable_nonboot_cpus_begin(void) 1277 { 1278 set_mtrr_aps_delayed_init(); 1279 } 1280 1281 void arch_enable_nonboot_cpus_end(void) 1282 { 1283 mtrr_aps_init(); 1284 } 1285 1286 /* 1287 * Early setup to make printk work. 1288 */ 1289 void __init native_smp_prepare_boot_cpu(void) 1290 { 1291 int me = smp_processor_id(); 1292 switch_to_new_gdt(me); 1293 /* already set me in cpu_online_mask in boot_cpu_init() */ 1294 cpumask_set_cpu(me, cpu_callout_mask); 1295 cpu_set_state_online(me); 1296 } 1297 1298 void __init native_smp_cpus_done(unsigned int max_cpus) 1299 { 1300 int ncpus; 1301 1302 pr_debug("Boot done\n"); 1303 /* 1304 * Today neither Intel nor AMD support heterogenous systems so 1305 * extrapolate the boot cpu's data to all packages. 1306 */ 1307 ncpus = cpu_data(0).booted_cores * smp_num_siblings; 1308 __max_logical_packages = DIV_ROUND_UP(nr_cpu_ids, ncpus); 1309 pr_info("Max logical packages: %u\n", __max_logical_packages); 1310 1311 if (x86_has_numa_in_package) 1312 set_sched_topology(x86_numa_in_package_topology); 1313 1314 nmi_selftest(); 1315 impress_friends(); 1316 mtrr_aps_init(); 1317 } 1318 1319 static int __initdata setup_possible_cpus = -1; 1320 static int __init _setup_possible_cpus(char *str) 1321 { 1322 get_option(&str, &setup_possible_cpus); 1323 return 0; 1324 } 1325 early_param("possible_cpus", _setup_possible_cpus); 1326 1327 1328 /* 1329 * cpu_possible_mask should be static, it cannot change as cpu's 1330 * are onlined, or offlined. The reason is per-cpu data-structures 1331 * are allocated by some modules at init time, and dont expect to 1332 * do this dynamically on cpu arrival/departure. 1333 * cpu_present_mask on the other hand can change dynamically. 1334 * In case when cpu_hotplug is not compiled, then we resort to current 1335 * behaviour, which is cpu_possible == cpu_present. 1336 * - Ashok Raj 1337 * 1338 * Three ways to find out the number of additional hotplug CPUs: 1339 * - If the BIOS specified disabled CPUs in ACPI/mptables use that. 1340 * - The user can overwrite it with possible_cpus=NUM 1341 * - Otherwise don't reserve additional CPUs. 1342 * We do this because additional CPUs waste a lot of memory. 1343 * -AK 1344 */ 1345 __init void prefill_possible_map(void) 1346 { 1347 int i, possible; 1348 1349 /* No boot processor was found in mptable or ACPI MADT */ 1350 if (!num_processors) { 1351 if (boot_cpu_has(X86_FEATURE_APIC)) { 1352 int apicid = boot_cpu_physical_apicid; 1353 int cpu = hard_smp_processor_id(); 1354 1355 pr_warn("Boot CPU (id %d) not listed by BIOS\n", cpu); 1356 1357 /* Make sure boot cpu is enumerated */ 1358 if (apic->cpu_present_to_apicid(0) == BAD_APICID && 1359 apic->apic_id_valid(apicid)) 1360 generic_processor_info(apicid, boot_cpu_apic_version); 1361 } 1362 1363 if (!num_processors) 1364 num_processors = 1; 1365 } 1366 1367 i = setup_max_cpus ?: 1; 1368 if (setup_possible_cpus == -1) { 1369 possible = num_processors; 1370 #ifdef CONFIG_HOTPLUG_CPU 1371 if (setup_max_cpus) 1372 possible += disabled_cpus; 1373 #else 1374 if (possible > i) 1375 possible = i; 1376 #endif 1377 } else 1378 possible = setup_possible_cpus; 1379 1380 total_cpus = max_t(int, possible, num_processors + disabled_cpus); 1381 1382 /* nr_cpu_ids could be reduced via nr_cpus= */ 1383 if (possible > nr_cpu_ids) { 1384 pr_warn("%d Processors exceeds NR_CPUS limit of %u\n", 1385 possible, nr_cpu_ids); 1386 possible = nr_cpu_ids; 1387 } 1388 1389 #ifdef CONFIG_HOTPLUG_CPU 1390 if (!setup_max_cpus) 1391 #endif 1392 if (possible > i) { 1393 pr_warn("%d Processors exceeds max_cpus limit of %u\n", 1394 possible, setup_max_cpus); 1395 possible = i; 1396 } 1397 1398 nr_cpu_ids = possible; 1399 1400 pr_info("Allowing %d CPUs, %d hotplug CPUs\n", 1401 possible, max_t(int, possible - num_processors, 0)); 1402 1403 reset_cpu_possible_mask(); 1404 1405 for (i = 0; i < possible; i++) 1406 set_cpu_possible(i, true); 1407 } 1408 1409 #ifdef CONFIG_HOTPLUG_CPU 1410 1411 /* Recompute SMT state for all CPUs on offline */ 1412 static void recompute_smt_state(void) 1413 { 1414 int max_threads, cpu; 1415 1416 max_threads = 0; 1417 for_each_online_cpu (cpu) { 1418 int threads = cpumask_weight(topology_sibling_cpumask(cpu)); 1419 1420 if (threads > max_threads) 1421 max_threads = threads; 1422 } 1423 __max_smt_threads = max_threads; 1424 } 1425 1426 static void remove_siblinginfo(int cpu) 1427 { 1428 int sibling; 1429 struct cpuinfo_x86 *c = &cpu_data(cpu); 1430 1431 for_each_cpu(sibling, topology_core_cpumask(cpu)) { 1432 cpumask_clear_cpu(cpu, topology_core_cpumask(sibling)); 1433 /*/ 1434 * last thread sibling in this cpu core going down 1435 */ 1436 if (cpumask_weight(topology_sibling_cpumask(cpu)) == 1) 1437 cpu_data(sibling).booted_cores--; 1438 } 1439 1440 for_each_cpu(sibling, topology_sibling_cpumask(cpu)) 1441 cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling)); 1442 for_each_cpu(sibling, cpu_llc_shared_mask(cpu)) 1443 cpumask_clear_cpu(cpu, cpu_llc_shared_mask(sibling)); 1444 cpumask_clear(cpu_llc_shared_mask(cpu)); 1445 cpumask_clear(topology_sibling_cpumask(cpu)); 1446 cpumask_clear(topology_core_cpumask(cpu)); 1447 c->phys_proc_id = 0; 1448 c->cpu_core_id = 0; 1449 cpumask_clear_cpu(cpu, cpu_sibling_setup_mask); 1450 recompute_smt_state(); 1451 } 1452 1453 static void remove_cpu_from_maps(int cpu) 1454 { 1455 set_cpu_online(cpu, false); 1456 cpumask_clear_cpu(cpu, cpu_callout_mask); 1457 cpumask_clear_cpu(cpu, cpu_callin_mask); 1458 /* was set by cpu_init() */ 1459 cpumask_clear_cpu(cpu, cpu_initialized_mask); 1460 numa_remove_cpu(cpu); 1461 } 1462 1463 void cpu_disable_common(void) 1464 { 1465 int cpu = smp_processor_id(); 1466 1467 remove_siblinginfo(cpu); 1468 1469 /* It's now safe to remove this processor from the online map */ 1470 lock_vector_lock(); 1471 remove_cpu_from_maps(cpu); 1472 unlock_vector_lock(); 1473 fixup_irqs(); 1474 lapic_offline(); 1475 } 1476 1477 int native_cpu_disable(void) 1478 { 1479 int ret; 1480 1481 ret = lapic_can_unplug_cpu(); 1482 if (ret) 1483 return ret; 1484 1485 clear_local_APIC(); 1486 cpu_disable_common(); 1487 1488 return 0; 1489 } 1490 1491 int common_cpu_die(unsigned int cpu) 1492 { 1493 int ret = 0; 1494 1495 /* We don't do anything here: idle task is faking death itself. */ 1496 1497 /* They ack this in play_dead() by setting CPU_DEAD */ 1498 if (cpu_wait_death(cpu, 5)) { 1499 if (system_state == SYSTEM_RUNNING) 1500 pr_info("CPU %u is now offline\n", cpu); 1501 } else { 1502 pr_err("CPU %u didn't die...\n", cpu); 1503 ret = -1; 1504 } 1505 1506 return ret; 1507 } 1508 1509 void native_cpu_die(unsigned int cpu) 1510 { 1511 common_cpu_die(cpu); 1512 } 1513 1514 void play_dead_common(void) 1515 { 1516 idle_task_exit(); 1517 1518 /* Ack it */ 1519 (void)cpu_report_death(); 1520 1521 /* 1522 * With physical CPU hotplug, we should halt the cpu 1523 */ 1524 local_irq_disable(); 1525 } 1526 1527 static bool wakeup_cpu0(void) 1528 { 1529 if (smp_processor_id() == 0 && enable_start_cpu0) 1530 return true; 1531 1532 return false; 1533 } 1534 1535 /* 1536 * We need to flush the caches before going to sleep, lest we have 1537 * dirty data in our caches when we come back up. 1538 */ 1539 static inline void mwait_play_dead(void) 1540 { 1541 unsigned int eax, ebx, ecx, edx; 1542 unsigned int highest_cstate = 0; 1543 unsigned int highest_subcstate = 0; 1544 void *mwait_ptr; 1545 int i; 1546 1547 if (!this_cpu_has(X86_FEATURE_MWAIT)) 1548 return; 1549 if (!this_cpu_has(X86_FEATURE_CLFLUSH)) 1550 return; 1551 if (__this_cpu_read(cpu_info.cpuid_level) < CPUID_MWAIT_LEAF) 1552 return; 1553 1554 eax = CPUID_MWAIT_LEAF; 1555 ecx = 0; 1556 native_cpuid(&eax, &ebx, &ecx, &edx); 1557 1558 /* 1559 * eax will be 0 if EDX enumeration is not valid. 1560 * Initialized below to cstate, sub_cstate value when EDX is valid. 1561 */ 1562 if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED)) { 1563 eax = 0; 1564 } else { 1565 edx >>= MWAIT_SUBSTATE_SIZE; 1566 for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) { 1567 if (edx & MWAIT_SUBSTATE_MASK) { 1568 highest_cstate = i; 1569 highest_subcstate = edx & MWAIT_SUBSTATE_MASK; 1570 } 1571 } 1572 eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) | 1573 (highest_subcstate - 1); 1574 } 1575 1576 /* 1577 * This should be a memory location in a cache line which is 1578 * unlikely to be touched by other processors. The actual 1579 * content is immaterial as it is not actually modified in any way. 1580 */ 1581 mwait_ptr = ¤t_thread_info()->flags; 1582 1583 wbinvd(); 1584 1585 while (1) { 1586 /* 1587 * The CLFLUSH is a workaround for erratum AAI65 for 1588 * the Xeon 7400 series. It's not clear it is actually 1589 * needed, but it should be harmless in either case. 1590 * The WBINVD is insufficient due to the spurious-wakeup 1591 * case where we return around the loop. 1592 */ 1593 mb(); 1594 clflush(mwait_ptr); 1595 mb(); 1596 __monitor(mwait_ptr, 0, 0); 1597 mb(); 1598 __mwait(eax, 0); 1599 /* 1600 * If NMI wants to wake up CPU0, start CPU0. 1601 */ 1602 if (wakeup_cpu0()) 1603 start_cpu0(); 1604 } 1605 } 1606 1607 void hlt_play_dead(void) 1608 { 1609 if (__this_cpu_read(cpu_info.x86) >= 4) 1610 wbinvd(); 1611 1612 while (1) { 1613 native_halt(); 1614 /* 1615 * If NMI wants to wake up CPU0, start CPU0. 1616 */ 1617 if (wakeup_cpu0()) 1618 start_cpu0(); 1619 } 1620 } 1621 1622 void native_play_dead(void) 1623 { 1624 play_dead_common(); 1625 tboot_shutdown(TB_SHUTDOWN_WFS); 1626 1627 mwait_play_dead(); /* Only returns on failure */ 1628 if (cpuidle_play_dead()) 1629 hlt_play_dead(); 1630 } 1631 1632 #else /* ... !CONFIG_HOTPLUG_CPU */ 1633 int native_cpu_disable(void) 1634 { 1635 return -ENOSYS; 1636 } 1637 1638 void native_cpu_die(unsigned int cpu) 1639 { 1640 /* We said "no" in __cpu_disable */ 1641 BUG(); 1642 } 1643 1644 void native_play_dead(void) 1645 { 1646 BUG(); 1647 } 1648 1649 #endif 1650