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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/kexec.h>
57#include <linux/numa.h>
58#include <linux/pgtable.h>
59#include <linux/overflow.h>
60#include <linux/stackprotector.h>
61#include <linux/cpuhotplug.h>
62#include <linux/mc146818rtc.h>
63#include <linux/acpi.h>
64
65#include <asm/acpi.h>
66#include <asm/cacheinfo.h>
67#include <asm/desc.h>
68#include <asm/nmi.h>
69#include <asm/irq.h>
70#include <asm/realmode.h>
71#include <asm/cpu.h>
72#include <asm/numa.h>
73#include <asm/tlbflush.h>
74#include <asm/mtrr.h>
75#include <asm/mwait.h>
76#include <asm/apic.h>
77#include <asm/io_apic.h>
78#include <asm/fpu/api.h>
79#include <asm/setup.h>
80#include <asm/uv/uv.h>
81#include <asm/microcode.h>
82#include <asm/i8259.h>
83#include <asm/misc.h>
84#include <asm/qspinlock.h>
85#include <asm/intel-family.h>
86#include <asm/cpu_device_id.h>
87#include <asm/spec-ctrl.h>
88#include <asm/hw_irq.h>
89#include <asm/stackprotector.h>
90#include <asm/sev.h>
91#include <asm/spec-ctrl.h>
92
93/* representing HT siblings of each logical CPU */
94DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);
95EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
96
97/* representing HT and core siblings of each logical CPU */
98DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_map);
99EXPORT_PER_CPU_SYMBOL(cpu_core_map);
100
101/* representing HT, core, and die siblings of each logical CPU */
102DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_die_map);
103EXPORT_PER_CPU_SYMBOL(cpu_die_map);
104
105/* CPUs which are the primary SMT threads */
106struct cpumask __cpu_primary_thread_mask __read_mostly;
107
108/* Representing CPUs for which sibling maps can be computed */
109static cpumask_var_t cpu_sibling_setup_mask;
110
111struct mwait_cpu_dead {
112 unsigned int control;
113 unsigned int status;
114};
115
116#define CPUDEAD_MWAIT_WAIT 0xDEADBEEF
117#define CPUDEAD_MWAIT_KEXEC_HLT 0x4A17DEAD
118
119/*
120 * Cache line aligned data for mwait_play_dead(). Separate on purpose so
121 * that it's unlikely to be touched by other CPUs.
122 */
123static DEFINE_PER_CPU_ALIGNED(struct mwait_cpu_dead, mwait_cpu_dead);
124
125/* Maximum number of SMT threads on any online core */
126int __read_mostly __max_smt_threads = 1;
127
128/* Flag to indicate if a complete sched domain rebuild is required */
129bool x86_topology_update;
130
131int arch_update_cpu_topology(void)
132{
133 int retval = x86_topology_update;
134
135 x86_topology_update = false;
136 return retval;
137}
138
139static unsigned int smpboot_warm_reset_vector_count;
140
141static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip)
142{
143 unsigned long flags;
144
145 spin_lock_irqsave(&rtc_lock, flags);
146 if (!smpboot_warm_reset_vector_count++) {
147 CMOS_WRITE(0xa, 0xf);
148 *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_HIGH)) = start_eip >> 4;
149 *((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = start_eip & 0xf;
150 }
151 spin_unlock_irqrestore(&rtc_lock, flags);
152}
153
154static inline void smpboot_restore_warm_reset_vector(void)
155{
156 unsigned long flags;
157
158 /*
159 * Paranoid: Set warm reset code and vector here back
160 * to default values.
161 */
162 spin_lock_irqsave(&rtc_lock, flags);
163 if (!--smpboot_warm_reset_vector_count) {
164 CMOS_WRITE(0, 0xf);
165 *((volatile u32 *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = 0;
166 }
167 spin_unlock_irqrestore(&rtc_lock, flags);
168
169}
170
171/* Run the next set of setup steps for the upcoming CPU */
172static void ap_starting(void)
173{
174 int cpuid = smp_processor_id();
175
176 /* Mop up eventual mwait_play_dead() wreckage */
177 this_cpu_write(mwait_cpu_dead.status, 0);
178 this_cpu_write(mwait_cpu_dead.control, 0);
179
180 /*
181 * If woken up by an INIT in an 82489DX configuration the alive
182 * synchronization guarantees that the CPU does not reach this
183 * point before an INIT_deassert IPI reaches the local APIC, so it
184 * is now safe to touch the local APIC.
185 *
186 * Set up this CPU, first the APIC, which is probably redundant on
187 * most boards.
188 */
189 apic_ap_setup();
190
191 /* Save the processor parameters. */
192 smp_store_cpu_info(cpuid);
193
194 /*
195 * The topology information must be up to date before
196 * notify_cpu_starting().
197 */
198 set_cpu_sibling_map(cpuid);
199
200 ap_init_aperfmperf();
201
202 pr_debug("Stack at about %p\n", &cpuid);
203
204 wmb();
205
206 /*
207 * This runs the AP through all the cpuhp states to its target
208 * state CPUHP_ONLINE.
209 */
210 notify_cpu_starting(cpuid);
211}
212
213static void ap_calibrate_delay(void)
214{
215 /*
216 * Calibrate the delay loop and update loops_per_jiffy in cpu_data.
217 * smp_store_cpu_info() stored a value that is close but not as
218 * accurate as the value just calculated.
219 *
220 * As this is invoked after the TSC synchronization check,
221 * calibrate_delay_is_known() will skip the calibration routine
222 * when TSC is synchronized across sockets.
223 */
224 calibrate_delay();
225 cpu_data(smp_processor_id()).loops_per_jiffy = loops_per_jiffy;
226}
227
228/*
229 * Activate a secondary processor.
230 */
231static void notrace start_secondary(void *unused)
232{
233 /*
234 * Don't put *anything* except direct CPU state initialization
235 * before cpu_init(), SMP booting is too fragile that we want to
236 * limit the things done here to the most necessary things.
237 */
238 cr4_init();
239
240 /*
241 * 32-bit specific. 64-bit reaches this code with the correct page
242 * table established. Yet another historical divergence.
243 */
244 if (IS_ENABLED(CONFIG_X86_32)) {
245 /* switch away from the initial page table */
246 load_cr3(swapper_pg_dir);
247 __flush_tlb_all();
248 }
249
250 cpu_init_exception_handling(false);
251
252 /*
253 * Load the microcode before reaching the AP alive synchronization
254 * point below so it is not part of the full per CPU serialized
255 * bringup part when "parallel" bringup is enabled.
256 *
257 * That's even safe when hyperthreading is enabled in the CPU as
258 * the core code starts the primary threads first and leaves the
259 * secondary threads waiting for SIPI. Loading microcode on
260 * physical cores concurrently is a safe operation.
261 *
262 * This covers both the Intel specific issue that concurrent
263 * microcode loading on SMT siblings must be prohibited and the
264 * vendor independent issue`that microcode loading which changes
265 * CPUID, MSRs etc. must be strictly serialized to maintain
266 * software state correctness.
267 */
268 load_ucode_ap();
269
270 /*
271 * Synchronization point with the hotplug core. Sets this CPUs
272 * synchronization state to ALIVE and spin-waits for the control CPU to
273 * release this CPU for further bringup.
274 */
275 cpuhp_ap_sync_alive();
276
277 cpu_init();
278 fpu__init_cpu();
279 rcutree_report_cpu_starting(raw_smp_processor_id());
280 x86_cpuinit.early_percpu_clock_init();
281
282 ap_starting();
283
284 /* Check TSC synchronization with the control CPU. */
285 check_tsc_sync_target();
286
287 /*
288 * Calibrate the delay loop after the TSC synchronization check.
289 * This allows to skip the calibration when TSC is synchronized
290 * across sockets.
291 */
292 ap_calibrate_delay();
293
294 speculative_store_bypass_ht_init();
295
296 /*
297 * Lock vector_lock, set CPU online and bring the vector
298 * allocator online. Online must be set with vector_lock held
299 * to prevent a concurrent irq setup/teardown from seeing a
300 * half valid vector space.
301 */
302 lock_vector_lock();
303 set_cpu_online(smp_processor_id(), true);
304 lapic_online();
305 unlock_vector_lock();
306 x86_platform.nmi_init();
307
308 /* enable local interrupts */
309 local_irq_enable();
310
311 x86_cpuinit.setup_percpu_clockev();
312
313 wmb();
314 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
315}
316
317/*
318 * The bootstrap kernel entry code has set these up. Save them for
319 * a given CPU
320 */
321void smp_store_cpu_info(int id)
322{
323 struct cpuinfo_x86 *c = &cpu_data(id);
324
325 /* Copy boot_cpu_data only on the first bringup */
326 if (!c->initialized)
327 *c = boot_cpu_data;
328 c->cpu_index = id;
329 /*
330 * During boot time, CPU0 has this setup already. Save the info when
331 * bringing up an AP.
332 */
333 identify_secondary_cpu(c);
334 c->initialized = true;
335}
336
337static bool
338topology_same_node(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
339{
340 int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
341
342 return (cpu_to_node(cpu1) == cpu_to_node(cpu2));
343}
344
345static bool
346topology_sane(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o, const char *name)
347{
348 int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
349
350 return !WARN_ONCE(!topology_same_node(c, o),
351 "sched: CPU #%d's %s-sibling CPU #%d is not on the same node! "
352 "[node: %d != %d]. Ignoring dependency.\n",
353 cpu1, name, cpu2, cpu_to_node(cpu1), cpu_to_node(cpu2));
354}
355
356#define link_mask(mfunc, c1, c2) \
357do { \
358 cpumask_set_cpu((c1), mfunc(c2)); \
359 cpumask_set_cpu((c2), mfunc(c1)); \
360} while (0)
361
362static bool match_smt(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
363{
364 if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
365 int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
366
367 if (c->topo.pkg_id == o->topo.pkg_id &&
368 c->topo.die_id == o->topo.die_id &&
369 c->topo.amd_node_id == o->topo.amd_node_id &&
370 per_cpu_llc_id(cpu1) == per_cpu_llc_id(cpu2)) {
371 if (c->topo.core_id == o->topo.core_id)
372 return topology_sane(c, o, "smt");
373
374 if ((c->topo.cu_id != 0xff) &&
375 (o->topo.cu_id != 0xff) &&
376 (c->topo.cu_id == o->topo.cu_id))
377 return topology_sane(c, o, "smt");
378 }
379
380 } else if (c->topo.pkg_id == o->topo.pkg_id &&
381 c->topo.die_id == o->topo.die_id &&
382 c->topo.core_id == o->topo.core_id) {
383 return topology_sane(c, o, "smt");
384 }
385
386 return false;
387}
388
389static bool match_die(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
390{
391 if (c->topo.pkg_id != o->topo.pkg_id || c->topo.die_id != o->topo.die_id)
392 return false;
393
394 if (cpu_feature_enabled(X86_FEATURE_TOPOEXT) && topology_amd_nodes_per_pkg() > 1)
395 return c->topo.amd_node_id == o->topo.amd_node_id;
396
397 return true;
398}
399
400static bool match_l2c(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
401{
402 int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
403
404 /* If the arch didn't set up l2c_id, fall back to SMT */
405 if (per_cpu_l2c_id(cpu1) == BAD_APICID)
406 return match_smt(c, o);
407
408 /* Do not match if L2 cache id does not match: */
409 if (per_cpu_l2c_id(cpu1) != per_cpu_l2c_id(cpu2))
410 return false;
411
412 return topology_sane(c, o, "l2c");
413}
414
415/*
416 * Unlike the other levels, we do not enforce keeping a
417 * multicore group inside a NUMA node. If this happens, we will
418 * discard the MC level of the topology later.
419 */
420static bool match_pkg(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
421{
422 if (c->topo.pkg_id == o->topo.pkg_id)
423 return true;
424 return false;
425}
426
427/*
428 * Define intel_cod_cpu[] for Intel COD (Cluster-on-Die) CPUs.
429 *
430 * Any Intel CPU that has multiple nodes per package and does not
431 * match intel_cod_cpu[] has the SNC (Sub-NUMA Cluster) topology.
432 *
433 * When in SNC mode, these CPUs enumerate an LLC that is shared
434 * by multiple NUMA nodes. The LLC is shared for off-package data
435 * access but private to the NUMA node (half of the package) for
436 * on-package access. CPUID (the source of the information about
437 * the LLC) can only enumerate the cache as shared or unshared,
438 * but not this particular configuration.
439 */
440
441static const struct x86_cpu_id intel_cod_cpu[] = {
442 X86_MATCH_VFM(INTEL_HASWELL_X, 0), /* COD */
443 X86_MATCH_VFM(INTEL_BROADWELL_X, 0), /* COD */
444 X86_MATCH_VFM(INTEL_ANY, 1), /* SNC */
445 {}
446};
447
448static bool match_llc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
449{
450 const struct x86_cpu_id *id = x86_match_cpu(intel_cod_cpu);
451 int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
452 bool intel_snc = id && id->driver_data;
453
454 /* Do not match if we do not have a valid APICID for cpu: */
455 if (per_cpu_llc_id(cpu1) == BAD_APICID)
456 return false;
457
458 /* Do not match if LLC id does not match: */
459 if (per_cpu_llc_id(cpu1) != per_cpu_llc_id(cpu2))
460 return false;
461
462 /*
463 * Allow the SNC topology without warning. Return of false
464 * means 'c' does not share the LLC of 'o'. This will be
465 * reflected to userspace.
466 */
467 if (match_pkg(c, o) && !topology_same_node(c, o) && intel_snc)
468 return false;
469
470 return topology_sane(c, o, "llc");
471}
472
473
474static inline int x86_sched_itmt_flags(void)
475{
476 return sysctl_sched_itmt_enabled ? SD_ASYM_PACKING : 0;
477}
478
479#ifdef CONFIG_SCHED_MC
480static int x86_core_flags(void)
481{
482 return cpu_core_flags() | x86_sched_itmt_flags();
483}
484#endif
485#ifdef CONFIG_SCHED_SMT
486static int x86_smt_flags(void)
487{
488 return cpu_smt_flags();
489}
490#endif
491#ifdef CONFIG_SCHED_CLUSTER
492static int x86_cluster_flags(void)
493{
494 return cpu_cluster_flags() | x86_sched_itmt_flags();
495}
496#endif
497
498/*
499 * Set if a package/die has multiple NUMA nodes inside.
500 * AMD Magny-Cours, Intel Cluster-on-Die, and Intel
501 * Sub-NUMA Clustering have this.
502 */
503static bool x86_has_numa_in_package;
504
505static struct sched_domain_topology_level x86_topology[6];
506
507static void __init build_sched_topology(void)
508{
509 int i = 0;
510
511#ifdef CONFIG_SCHED_SMT
512 x86_topology[i++] = (struct sched_domain_topology_level){
513 cpu_smt_mask, x86_smt_flags, SD_INIT_NAME(SMT)
514 };
515#endif
516#ifdef CONFIG_SCHED_CLUSTER
517 x86_topology[i++] = (struct sched_domain_topology_level){
518 cpu_clustergroup_mask, x86_cluster_flags, SD_INIT_NAME(CLS)
519 };
520#endif
521#ifdef CONFIG_SCHED_MC
522 x86_topology[i++] = (struct sched_domain_topology_level){
523 cpu_coregroup_mask, x86_core_flags, SD_INIT_NAME(MC)
524 };
525#endif
526 /*
527 * When there is NUMA topology inside the package skip the PKG domain
528 * since the NUMA domains will auto-magically create the right spanning
529 * domains based on the SLIT.
530 */
531 if (!x86_has_numa_in_package) {
532 x86_topology[i++] = (struct sched_domain_topology_level){
533 cpu_cpu_mask, x86_sched_itmt_flags, SD_INIT_NAME(PKG)
534 };
535 }
536
537 /*
538 * There must be one trailing NULL entry left.
539 */
540 BUG_ON(i >= ARRAY_SIZE(x86_topology)-1);
541
542 set_sched_topology(x86_topology);
543}
544
545void set_cpu_sibling_map(int cpu)
546{
547 bool has_smt = __max_threads_per_core > 1;
548 bool has_mp = has_smt || topology_num_cores_per_package() > 1;
549 struct cpuinfo_x86 *c = &cpu_data(cpu);
550 struct cpuinfo_x86 *o;
551 int i, threads;
552
553 cpumask_set_cpu(cpu, cpu_sibling_setup_mask);
554
555 if (!has_mp) {
556 cpumask_set_cpu(cpu, topology_sibling_cpumask(cpu));
557 cpumask_set_cpu(cpu, cpu_llc_shared_mask(cpu));
558 cpumask_set_cpu(cpu, cpu_l2c_shared_mask(cpu));
559 cpumask_set_cpu(cpu, topology_core_cpumask(cpu));
560 cpumask_set_cpu(cpu, topology_die_cpumask(cpu));
561 c->booted_cores = 1;
562 return;
563 }
564
565 for_each_cpu(i, cpu_sibling_setup_mask) {
566 o = &cpu_data(i);
567
568 if (match_pkg(c, o) && !topology_same_node(c, o))
569 x86_has_numa_in_package = true;
570
571 if ((i == cpu) || (has_smt && match_smt(c, o)))
572 link_mask(topology_sibling_cpumask, cpu, i);
573
574 if ((i == cpu) || (has_mp && match_llc(c, o)))
575 link_mask(cpu_llc_shared_mask, cpu, i);
576
577 if ((i == cpu) || (has_mp && match_l2c(c, o)))
578 link_mask(cpu_l2c_shared_mask, cpu, i);
579
580 if ((i == cpu) || (has_mp && match_die(c, o)))
581 link_mask(topology_die_cpumask, cpu, i);
582 }
583
584 threads = cpumask_weight(topology_sibling_cpumask(cpu));
585 if (threads > __max_smt_threads)
586 __max_smt_threads = threads;
587
588 for_each_cpu(i, topology_sibling_cpumask(cpu))
589 cpu_data(i).smt_active = threads > 1;
590
591 /*
592 * This needs a separate iteration over the cpus because we rely on all
593 * topology_sibling_cpumask links to be set-up.
594 */
595 for_each_cpu(i, cpu_sibling_setup_mask) {
596 o = &cpu_data(i);
597
598 if ((i == cpu) || (has_mp && match_pkg(c, o))) {
599 link_mask(topology_core_cpumask, cpu, i);
600
601 /*
602 * Does this new cpu bringup a new core?
603 */
604 if (threads == 1) {
605 /*
606 * for each core in package, increment
607 * the booted_cores for this new cpu
608 */
609 if (cpumask_first(
610 topology_sibling_cpumask(i)) == i)
611 c->booted_cores++;
612 /*
613 * increment the core count for all
614 * the other cpus in this package
615 */
616 if (i != cpu)
617 cpu_data(i).booted_cores++;
618 } else if (i != cpu && !c->booted_cores)
619 c->booted_cores = cpu_data(i).booted_cores;
620 }
621 }
622}
623
624/* maps the cpu to the sched domain representing multi-core */
625const struct cpumask *cpu_coregroup_mask(int cpu)
626{
627 return cpu_llc_shared_mask(cpu);
628}
629
630const struct cpumask *cpu_clustergroup_mask(int cpu)
631{
632 return cpu_l2c_shared_mask(cpu);
633}
634EXPORT_SYMBOL_GPL(cpu_clustergroup_mask);
635
636static void impress_friends(void)
637{
638 int cpu;
639 unsigned long bogosum = 0;
640 /*
641 * Allow the user to impress friends.
642 */
643 pr_debug("Before bogomips\n");
644 for_each_online_cpu(cpu)
645 bogosum += cpu_data(cpu).loops_per_jiffy;
646
647 pr_info("Total of %d processors activated (%lu.%02lu BogoMIPS)\n",
648 num_online_cpus(),
649 bogosum/(500000/HZ),
650 (bogosum/(5000/HZ))%100);
651
652 pr_debug("Before bogocount - setting activated=1\n");
653}
654
655/*
656 * The Multiprocessor Specification 1.4 (1997) example code suggests
657 * that there should be a 10ms delay between the BSP asserting INIT
658 * and de-asserting INIT, when starting a remote processor.
659 * But that slows boot and resume on modern processors, which include
660 * many cores and don't require that delay.
661 *
662 * Cmdline "init_cpu_udelay=" is available to over-ride this delay.
663 * Modern processor families are quirked to remove the delay entirely.
664 */
665#define UDELAY_10MS_DEFAULT 10000
666
667static unsigned int init_udelay = UINT_MAX;
668
669static int __init cpu_init_udelay(char *str)
670{
671 get_option(&str, &init_udelay);
672
673 return 0;
674}
675early_param("cpu_init_udelay", cpu_init_udelay);
676
677static void __init smp_quirk_init_udelay(void)
678{
679 /* if cmdline changed it from default, leave it alone */
680 if (init_udelay != UINT_MAX)
681 return;
682
683 /* if modern processor, use no delay */
684 if (((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && (boot_cpu_data.x86 == 6)) ||
685 ((boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) && (boot_cpu_data.x86 >= 0x18)) ||
686 ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && (boot_cpu_data.x86 >= 0xF))) {
687 init_udelay = 0;
688 return;
689 }
690 /* else, use legacy delay */
691 init_udelay = UDELAY_10MS_DEFAULT;
692}
693
694/*
695 * Wake up AP by INIT, INIT, STARTUP sequence.
696 */
697static void send_init_sequence(u32 phys_apicid)
698{
699 int maxlvt = lapic_get_maxlvt();
700
701 /* Be paranoid about clearing APIC errors. */
702 if (APIC_INTEGRATED(boot_cpu_apic_version)) {
703 /* Due to the Pentium erratum 3AP. */
704 if (maxlvt > 3)
705 apic_write(APIC_ESR, 0);
706 apic_read(APIC_ESR);
707 }
708
709 /* Assert INIT on the target CPU */
710 apic_icr_write(APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT, phys_apicid);
711 safe_apic_wait_icr_idle();
712
713 udelay(init_udelay);
714
715 /* Deassert INIT on the target CPU */
716 apic_icr_write(APIC_INT_LEVELTRIG | APIC_DM_INIT, phys_apicid);
717 safe_apic_wait_icr_idle();
718}
719
720/*
721 * Wake up AP by INIT, INIT, STARTUP sequence.
722 */
723static int wakeup_secondary_cpu_via_init(u32 phys_apicid, unsigned long start_eip)
724{
725 unsigned long send_status = 0, accept_status = 0;
726 int num_starts, j, maxlvt;
727
728 preempt_disable();
729 maxlvt = lapic_get_maxlvt();
730 send_init_sequence(phys_apicid);
731
732 mb();
733
734 /*
735 * Should we send STARTUP IPIs ?
736 *
737 * Determine this based on the APIC version.
738 * If we don't have an integrated APIC, don't send the STARTUP IPIs.
739 */
740 if (APIC_INTEGRATED(boot_cpu_apic_version))
741 num_starts = 2;
742 else
743 num_starts = 0;
744
745 /*
746 * Run STARTUP IPI loop.
747 */
748 pr_debug("#startup loops: %d\n", num_starts);
749
750 for (j = 1; j <= num_starts; j++) {
751 pr_debug("Sending STARTUP #%d\n", j);
752 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
753 apic_write(APIC_ESR, 0);
754 apic_read(APIC_ESR);
755 pr_debug("After apic_write\n");
756
757 /*
758 * STARTUP IPI
759 */
760
761 /* Target chip */
762 /* Boot on the stack */
763 /* Kick the second */
764 apic_icr_write(APIC_DM_STARTUP | (start_eip >> 12),
765 phys_apicid);
766
767 /*
768 * Give the other CPU some time to accept the IPI.
769 */
770 if (init_udelay == 0)
771 udelay(10);
772 else
773 udelay(300);
774
775 pr_debug("Startup point 1\n");
776
777 pr_debug("Waiting for send to finish...\n");
778 send_status = safe_apic_wait_icr_idle();
779
780 /*
781 * Give the other CPU some time to accept the IPI.
782 */
783 if (init_udelay == 0)
784 udelay(10);
785 else
786 udelay(200);
787
788 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
789 apic_write(APIC_ESR, 0);
790 accept_status = (apic_read(APIC_ESR) & 0xEF);
791 if (send_status || accept_status)
792 break;
793 }
794 pr_debug("After Startup\n");
795
796 if (send_status)
797 pr_err("APIC never delivered???\n");
798 if (accept_status)
799 pr_err("APIC delivery error (%lx)\n", accept_status);
800
801 preempt_enable();
802 return (send_status | accept_status);
803}
804
805/* reduce the number of lines printed when booting a large cpu count system */
806static void announce_cpu(int cpu, int apicid)
807{
808 static int width, node_width, first = 1;
809 static int current_node = NUMA_NO_NODE;
810 int node = early_cpu_to_node(cpu);
811
812 if (!width)
813 width = num_digits(num_possible_cpus()) + 1; /* + '#' sign */
814
815 if (!node_width)
816 node_width = num_digits(num_possible_nodes()) + 1; /* + '#' */
817
818 if (system_state < SYSTEM_RUNNING) {
819 if (first)
820 pr_info("x86: Booting SMP configuration:\n");
821
822 if (node != current_node) {
823 if (current_node > (-1))
824 pr_cont("\n");
825 current_node = node;
826
827 printk(KERN_INFO ".... node %*s#%d, CPUs: ",
828 node_width - num_digits(node), " ", node);
829 }
830
831 /* Add padding for the BSP */
832 if (first)
833 pr_cont("%*s", width + 1, " ");
834 first = 0;
835
836 pr_cont("%*s#%d", width - num_digits(cpu), " ", cpu);
837 } else
838 pr_info("Booting Node %d Processor %d APIC 0x%x\n",
839 node, cpu, apicid);
840}
841
842int common_cpu_up(unsigned int cpu, struct task_struct *idle)
843{
844 int ret;
845
846 /* Just in case we booted with a single CPU. */
847 alternatives_enable_smp();
848
849 per_cpu(pcpu_hot.current_task, cpu) = idle;
850 cpu_init_stack_canary(cpu, idle);
851
852 /* Initialize the interrupt stack(s) */
853 ret = irq_init_percpu_irqstack(cpu);
854 if (ret)
855 return ret;
856
857#ifdef CONFIG_X86_32
858 /* Stack for startup_32 can be just as for start_secondary onwards */
859 per_cpu(pcpu_hot.top_of_stack, cpu) = task_top_of_stack(idle);
860#endif
861 return 0;
862}
863
864/*
865 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
866 * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
867 * Returns zero if startup was successfully sent, else error code from
868 * ->wakeup_secondary_cpu.
869 */
870static int do_boot_cpu(u32 apicid, int cpu, struct task_struct *idle)
871{
872 unsigned long start_ip = real_mode_header->trampoline_start;
873 int ret;
874
875#ifdef CONFIG_X86_64
876 /* If 64-bit wakeup method exists, use the 64-bit mode trampoline IP */
877 if (apic->wakeup_secondary_cpu_64)
878 start_ip = real_mode_header->trampoline_start64;
879#endif
880 idle->thread.sp = (unsigned long)task_pt_regs(idle);
881 initial_code = (unsigned long)start_secondary;
882
883 if (IS_ENABLED(CONFIG_X86_32)) {
884 early_gdt_descr.address = (unsigned long)get_cpu_gdt_rw(cpu);
885 initial_stack = idle->thread.sp;
886 } else if (!(smpboot_control & STARTUP_PARALLEL_MASK)) {
887 smpboot_control = cpu;
888 }
889
890 /* Enable the espfix hack for this CPU */
891 init_espfix_ap(cpu);
892
893 /* So we see what's up */
894 announce_cpu(cpu, apicid);
895
896 /*
897 * This grunge runs the startup process for
898 * the targeted processor.
899 */
900 if (x86_platform.legacy.warm_reset) {
901
902 pr_debug("Setting warm reset code and vector.\n");
903
904 smpboot_setup_warm_reset_vector(start_ip);
905 /*
906 * Be paranoid about clearing APIC errors.
907 */
908 if (APIC_INTEGRATED(boot_cpu_apic_version)) {
909 apic_write(APIC_ESR, 0);
910 apic_read(APIC_ESR);
911 }
912 }
913
914 smp_mb();
915
916 /*
917 * Wake up a CPU in difference cases:
918 * - Use a method from the APIC driver if one defined, with wakeup
919 * straight to 64-bit mode preferred over wakeup to RM.
920 * Otherwise,
921 * - Use an INIT boot APIC message
922 */
923 if (apic->wakeup_secondary_cpu_64)
924 ret = apic->wakeup_secondary_cpu_64(apicid, start_ip);
925 else if (apic->wakeup_secondary_cpu)
926 ret = apic->wakeup_secondary_cpu(apicid, start_ip);
927 else
928 ret = wakeup_secondary_cpu_via_init(apicid, start_ip);
929
930 /* If the wakeup mechanism failed, cleanup the warm reset vector */
931 if (ret)
932 arch_cpuhp_cleanup_kick_cpu(cpu);
933 return ret;
934}
935
936int native_kick_ap(unsigned int cpu, struct task_struct *tidle)
937{
938 u32 apicid = apic->cpu_present_to_apicid(cpu);
939 int err;
940
941 lockdep_assert_irqs_enabled();
942
943 pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu);
944
945 if (apicid == BAD_APICID || !apic_id_valid(apicid)) {
946 pr_err("CPU %u has invalid APIC ID %x. Aborting bringup\n", cpu, apicid);
947 return -EINVAL;
948 }
949
950 if (!test_bit(apicid, phys_cpu_present_map)) {
951 pr_err("CPU %u APIC ID %x is not present. Aborting bringup\n", cpu, apicid);
952 return -EINVAL;
953 }
954
955 /*
956 * Save current MTRR state in case it was changed since early boot
957 * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
958 */
959 mtrr_save_state();
960
961 /* the FPU context is blank, nobody can own it */
962 per_cpu(fpu_fpregs_owner_ctx, cpu) = NULL;
963
964 err = common_cpu_up(cpu, tidle);
965 if (err)
966 return err;
967
968 err = do_boot_cpu(apicid, cpu, tidle);
969 if (err)
970 pr_err("do_boot_cpu failed(%d) to wakeup CPU#%u\n", err, cpu);
971
972 return err;
973}
974
975int arch_cpuhp_kick_ap_alive(unsigned int cpu, struct task_struct *tidle)
976{
977 return smp_ops.kick_ap_alive(cpu, tidle);
978}
979
980void arch_cpuhp_cleanup_kick_cpu(unsigned int cpu)
981{
982 /* Cleanup possible dangling ends... */
983 if (smp_ops.kick_ap_alive == native_kick_ap && x86_platform.legacy.warm_reset)
984 smpboot_restore_warm_reset_vector();
985}
986
987void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu)
988{
989 if (smp_ops.cleanup_dead_cpu)
990 smp_ops.cleanup_dead_cpu(cpu);
991
992 if (system_state == SYSTEM_RUNNING)
993 pr_info("CPU %u is now offline\n", cpu);
994}
995
996void arch_cpuhp_sync_state_poll(void)
997{
998 if (smp_ops.poll_sync_state)
999 smp_ops.poll_sync_state();
1000}
1001
1002/**
1003 * arch_disable_smp_support() - Disables SMP support for x86 at boottime
1004 */
1005void __init arch_disable_smp_support(void)
1006{
1007 disable_ioapic_support();
1008}
1009
1010/*
1011 * Fall back to non SMP mode after errors.
1012 *
1013 * RED-PEN audit/test this more. I bet there is more state messed up here.
1014 */
1015static __init void disable_smp(void)
1016{
1017 pr_info("SMP disabled\n");
1018
1019 disable_ioapic_support();
1020 topology_reset_possible_cpus_up();
1021
1022 cpumask_set_cpu(0, topology_sibling_cpumask(0));
1023 cpumask_set_cpu(0, topology_core_cpumask(0));
1024 cpumask_set_cpu(0, topology_die_cpumask(0));
1025}
1026
1027void __init smp_prepare_cpus_common(void)
1028{
1029 unsigned int cpu, node;
1030
1031 /* Mark all except the boot CPU as hotpluggable */
1032 for_each_possible_cpu(cpu) {
1033 if (cpu)
1034 per_cpu(cpu_info.cpu_index, cpu) = nr_cpu_ids;
1035 }
1036
1037 for_each_possible_cpu(cpu) {
1038 node = cpu_to_node(cpu);
1039
1040 zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu), GFP_KERNEL, node);
1041 zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu), GFP_KERNEL, node);
1042 zalloc_cpumask_var_node(&per_cpu(cpu_die_map, cpu), GFP_KERNEL, node);
1043 zalloc_cpumask_var_node(&per_cpu(cpu_llc_shared_map, cpu), GFP_KERNEL, node);
1044 zalloc_cpumask_var_node(&per_cpu(cpu_l2c_shared_map, cpu), GFP_KERNEL, node);
1045 }
1046
1047 set_cpu_sibling_map(0);
1048}
1049
1050void __init smp_prepare_boot_cpu(void)
1051{
1052 smp_ops.smp_prepare_boot_cpu();
1053}
1054
1055#ifdef CONFIG_X86_64
1056/* Establish whether parallel bringup can be supported. */
1057bool __init arch_cpuhp_init_parallel_bringup(void)
1058{
1059 if (!x86_cpuinit.parallel_bringup) {
1060 pr_info("Parallel CPU startup disabled by the platform\n");
1061 return false;
1062 }
1063
1064 smpboot_control = STARTUP_READ_APICID;
1065 pr_debug("Parallel CPU startup enabled: 0x%08x\n", smpboot_control);
1066 return true;
1067}
1068#endif
1069
1070/*
1071 * Prepare for SMP bootup.
1072 * @max_cpus: configured maximum number of CPUs, It is a legacy parameter
1073 * for common interface support.
1074 */
1075void __init native_smp_prepare_cpus(unsigned int max_cpus)
1076{
1077 smp_prepare_cpus_common();
1078
1079 switch (apic_intr_mode) {
1080 case APIC_PIC:
1081 case APIC_VIRTUAL_WIRE_NO_CONFIG:
1082 disable_smp();
1083 return;
1084 case APIC_SYMMETRIC_IO_NO_ROUTING:
1085 disable_smp();
1086 /* Setup local timer */
1087 x86_init.timers.setup_percpu_clockev();
1088 return;
1089 case APIC_VIRTUAL_WIRE:
1090 case APIC_SYMMETRIC_IO:
1091 break;
1092 }
1093
1094 /* Setup local timer */
1095 x86_init.timers.setup_percpu_clockev();
1096
1097 pr_info("CPU0: ");
1098 print_cpu_info(&cpu_data(0));
1099
1100 uv_system_init();
1101
1102 smp_quirk_init_udelay();
1103
1104 speculative_store_bypass_ht_init();
1105
1106 snp_set_wakeup_secondary_cpu();
1107}
1108
1109void arch_thaw_secondary_cpus_begin(void)
1110{
1111 set_cache_aps_delayed_init(true);
1112}
1113
1114void arch_thaw_secondary_cpus_end(void)
1115{
1116 cache_aps_init();
1117}
1118
1119/*
1120 * Early setup to make printk work.
1121 */
1122void __init native_smp_prepare_boot_cpu(void)
1123{
1124 int me = smp_processor_id();
1125
1126 /* SMP handles this from setup_per_cpu_areas() */
1127 if (!IS_ENABLED(CONFIG_SMP))
1128 switch_gdt_and_percpu_base(me);
1129
1130 native_pv_lock_init();
1131}
1132
1133void __init native_smp_cpus_done(unsigned int max_cpus)
1134{
1135 pr_debug("Boot done\n");
1136
1137 build_sched_topology();
1138 nmi_selftest();
1139 impress_friends();
1140 cache_aps_init();
1141}
1142
1143/* correctly size the local cpu masks */
1144void __init setup_cpu_local_masks(void)
1145{
1146 alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask);
1147}
1148
1149#ifdef CONFIG_HOTPLUG_CPU
1150
1151/* Recompute SMT state for all CPUs on offline */
1152static void recompute_smt_state(void)
1153{
1154 int max_threads, cpu;
1155
1156 max_threads = 0;
1157 for_each_online_cpu (cpu) {
1158 int threads = cpumask_weight(topology_sibling_cpumask(cpu));
1159
1160 if (threads > max_threads)
1161 max_threads = threads;
1162 }
1163 __max_smt_threads = max_threads;
1164}
1165
1166static void remove_siblinginfo(int cpu)
1167{
1168 int sibling;
1169 struct cpuinfo_x86 *c = &cpu_data(cpu);
1170
1171 for_each_cpu(sibling, topology_core_cpumask(cpu)) {
1172 cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
1173 /*/
1174 * last thread sibling in this cpu core going down
1175 */
1176 if (cpumask_weight(topology_sibling_cpumask(cpu)) == 1)
1177 cpu_data(sibling).booted_cores--;
1178 }
1179
1180 for_each_cpu(sibling, topology_die_cpumask(cpu))
1181 cpumask_clear_cpu(cpu, topology_die_cpumask(sibling));
1182
1183 for_each_cpu(sibling, topology_sibling_cpumask(cpu)) {
1184 cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling));
1185 if (cpumask_weight(topology_sibling_cpumask(sibling)) == 1)
1186 cpu_data(sibling).smt_active = false;
1187 }
1188
1189 for_each_cpu(sibling, cpu_llc_shared_mask(cpu))
1190 cpumask_clear_cpu(cpu, cpu_llc_shared_mask(sibling));
1191 for_each_cpu(sibling, cpu_l2c_shared_mask(cpu))
1192 cpumask_clear_cpu(cpu, cpu_l2c_shared_mask(sibling));
1193 cpumask_clear(cpu_llc_shared_mask(cpu));
1194 cpumask_clear(cpu_l2c_shared_mask(cpu));
1195 cpumask_clear(topology_sibling_cpumask(cpu));
1196 cpumask_clear(topology_core_cpumask(cpu));
1197 cpumask_clear(topology_die_cpumask(cpu));
1198 c->topo.core_id = 0;
1199 c->booted_cores = 0;
1200 cpumask_clear_cpu(cpu, cpu_sibling_setup_mask);
1201 recompute_smt_state();
1202}
1203
1204static void remove_cpu_from_maps(int cpu)
1205{
1206 set_cpu_online(cpu, false);
1207 numa_remove_cpu(cpu);
1208}
1209
1210void cpu_disable_common(void)
1211{
1212 int cpu = smp_processor_id();
1213
1214 remove_siblinginfo(cpu);
1215
1216 /* It's now safe to remove this processor from the online map */
1217 lock_vector_lock();
1218 remove_cpu_from_maps(cpu);
1219 unlock_vector_lock();
1220 fixup_irqs();
1221 lapic_offline();
1222}
1223
1224int native_cpu_disable(void)
1225{
1226 int ret;
1227
1228 ret = lapic_can_unplug_cpu();
1229 if (ret)
1230 return ret;
1231
1232 cpu_disable_common();
1233
1234 /*
1235 * Disable the local APIC. Otherwise IPI broadcasts will reach
1236 * it. It still responds normally to INIT, NMI, SMI, and SIPI
1237 * messages.
1238 *
1239 * Disabling the APIC must happen after cpu_disable_common()
1240 * which invokes fixup_irqs().
1241 *
1242 * Disabling the APIC preserves already set bits in IRR, but
1243 * an interrupt arriving after disabling the local APIC does not
1244 * set the corresponding IRR bit.
1245 *
1246 * fixup_irqs() scans IRR for set bits so it can raise a not
1247 * yet handled interrupt on the new destination CPU via an IPI
1248 * but obviously it can't do so for IRR bits which are not set.
1249 * IOW, interrupts arriving after disabling the local APIC will
1250 * be lost.
1251 */
1252 apic_soft_disable();
1253
1254 return 0;
1255}
1256
1257void play_dead_common(void)
1258{
1259 idle_task_exit();
1260
1261 cpuhp_ap_report_dead();
1262
1263 local_irq_disable();
1264}
1265
1266/*
1267 * We need to flush the caches before going to sleep, lest we have
1268 * dirty data in our caches when we come back up.
1269 */
1270static inline void mwait_play_dead(void)
1271{
1272 struct mwait_cpu_dead *md = this_cpu_ptr(&mwait_cpu_dead);
1273 unsigned int eax, ebx, ecx, edx;
1274 unsigned int highest_cstate = 0;
1275 unsigned int highest_subcstate = 0;
1276 int i;
1277
1278 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
1279 boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
1280 return;
1281 if (!this_cpu_has(X86_FEATURE_MWAIT))
1282 return;
1283 if (!this_cpu_has(X86_FEATURE_CLFLUSH))
1284 return;
1285 if (__this_cpu_read(cpu_info.cpuid_level) < CPUID_MWAIT_LEAF)
1286 return;
1287
1288 eax = CPUID_MWAIT_LEAF;
1289 ecx = 0;
1290 native_cpuid(&eax, &ebx, &ecx, &edx);
1291
1292 /*
1293 * eax will be 0 if EDX enumeration is not valid.
1294 * Initialized below to cstate, sub_cstate value when EDX is valid.
1295 */
1296 if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED)) {
1297 eax = 0;
1298 } else {
1299 edx >>= MWAIT_SUBSTATE_SIZE;
1300 for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) {
1301 if (edx & MWAIT_SUBSTATE_MASK) {
1302 highest_cstate = i;
1303 highest_subcstate = edx & MWAIT_SUBSTATE_MASK;
1304 }
1305 }
1306 eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) |
1307 (highest_subcstate - 1);
1308 }
1309
1310 /* Set up state for the kexec() hack below */
1311 md->status = CPUDEAD_MWAIT_WAIT;
1312 md->control = CPUDEAD_MWAIT_WAIT;
1313
1314 wbinvd();
1315
1316 while (1) {
1317 /*
1318 * The CLFLUSH is a workaround for erratum AAI65 for
1319 * the Xeon 7400 series. It's not clear it is actually
1320 * needed, but it should be harmless in either case.
1321 * The WBINVD is insufficient due to the spurious-wakeup
1322 * case where we return around the loop.
1323 */
1324 mb();
1325 clflush(md);
1326 mb();
1327 __monitor(md, 0, 0);
1328 mb();
1329 __mwait(eax, 0);
1330
1331 if (READ_ONCE(md->control) == CPUDEAD_MWAIT_KEXEC_HLT) {
1332 /*
1333 * Kexec is about to happen. Don't go back into mwait() as
1334 * the kexec kernel might overwrite text and data including
1335 * page tables and stack. So mwait() would resume when the
1336 * monitor cache line is written to and then the CPU goes
1337 * south due to overwritten text, page tables and stack.
1338 *
1339 * Note: This does _NOT_ protect against a stray MCE, NMI,
1340 * SMI. They will resume execution at the instruction
1341 * following the HLT instruction and run into the problem
1342 * which this is trying to prevent.
1343 */
1344 WRITE_ONCE(md->status, CPUDEAD_MWAIT_KEXEC_HLT);
1345 while(1)
1346 native_halt();
1347 }
1348 }
1349}
1350
1351/*
1352 * Kick all "offline" CPUs out of mwait on kexec(). See comment in
1353 * mwait_play_dead().
1354 */
1355void smp_kick_mwait_play_dead(void)
1356{
1357 u32 newstate = CPUDEAD_MWAIT_KEXEC_HLT;
1358 struct mwait_cpu_dead *md;
1359 unsigned int cpu, i;
1360
1361 for_each_cpu_andnot(cpu, cpu_present_mask, cpu_online_mask) {
1362 md = per_cpu_ptr(&mwait_cpu_dead, cpu);
1363
1364 /* Does it sit in mwait_play_dead() ? */
1365 if (READ_ONCE(md->status) != CPUDEAD_MWAIT_WAIT)
1366 continue;
1367
1368 /* Wait up to 5ms */
1369 for (i = 0; READ_ONCE(md->status) != newstate && i < 1000; i++) {
1370 /* Bring it out of mwait */
1371 WRITE_ONCE(md->control, newstate);
1372 udelay(5);
1373 }
1374
1375 if (READ_ONCE(md->status) != newstate)
1376 pr_err_once("CPU%u is stuck in mwait_play_dead()\n", cpu);
1377 }
1378}
1379
1380void __noreturn hlt_play_dead(void)
1381{
1382 if (__this_cpu_read(cpu_info.x86) >= 4)
1383 wbinvd();
1384
1385 while (1)
1386 native_halt();
1387}
1388
1389/*
1390 * native_play_dead() is essentially a __noreturn function, but it can't
1391 * be marked as such as the compiler may complain about it.
1392 */
1393void native_play_dead(void)
1394{
1395 if (cpu_feature_enabled(X86_FEATURE_KERNEL_IBRS))
1396 __update_spec_ctrl(0);
1397
1398 play_dead_common();
1399 tboot_shutdown(TB_SHUTDOWN_WFS);
1400
1401 mwait_play_dead();
1402 if (cpuidle_play_dead())
1403 hlt_play_dead();
1404}
1405
1406#else /* ... !CONFIG_HOTPLUG_CPU */
1407int native_cpu_disable(void)
1408{
1409 return -ENOSYS;
1410}
1411
1412void native_play_dead(void)
1413{
1414 BUG();
1415}
1416
1417#endif
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 */
86DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);
87EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
88
89/* representing HT and core siblings of each logical CPU */
90DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_map);
91EXPORT_PER_CPU_SYMBOL(cpu_core_map);
92
93/* representing HT, core, and die siblings of each logical CPU */
94DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_die_map);
95EXPORT_PER_CPU_SYMBOL(cpu_die_map);
96
97DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_llc_shared_map);
98
99/* Per CPU bogomips and other parameters */
100DEFINE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);
101EXPORT_PER_CPU_SYMBOL(cpu_info);
102
103/* Logical package management. We might want to allocate that dynamically */
104unsigned int __max_logical_packages __read_mostly;
105EXPORT_SYMBOL(__max_logical_packages);
106static unsigned int logical_packages __read_mostly;
107static unsigned int logical_die __read_mostly;
108
109/* Maximum number of SMT threads on any online core */
110int __read_mostly __max_smt_threads = 1;
111
112/* Flag to indicate if a complete sched domain rebuild is required */
113bool x86_topology_update;
114
115int arch_update_cpu_topology(void)
116{
117 int retval = x86_topology_update;
118
119 x86_topology_update = false;
120 return retval;
121}
122
123static 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
136static 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
151static 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 */
157static 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
211static int cpu0_logical_apicid;
212static int enable_start_cpu0;
213/*
214 * Activate a secondary processor.
215 */
216static 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 load_current_idt();
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 */
273bool 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 */
281bool 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 */
291int 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}
303EXPORT_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 */
309int 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}
323EXPORT_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 */
330int 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 }
344found:
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 */
353int 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 }
367found:
368 cpu_data(cpu).logical_die_id = new;
369 return 0;
370}
371
372void __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 */
388void 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
404static bool
405topology_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
412static bool
413topology_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) \
424do { \
425 cpumask_set_cpu((c1), mfunc(c2)); \
426 cpumask_set_cpu((c2), mfunc(c1)); \
427} while (0)
428
429static 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
470static const struct x86_cpu_id snc_cpu[] = {
471 X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_X, NULL),
472 {}
473};
474
475static 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 */
503static 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
510static 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)
520static 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
526static int x86_core_flags(void)
527{
528 return cpu_core_flags() | x86_sched_itmt_flags();
529}
530#endif
531#ifdef CONFIG_SCHED_SMT
532static int x86_smt_flags(void)
533{
534 return cpu_smt_flags() | x86_sched_itmt_flags();
535}
536#endif
537#endif
538
539static 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
549static 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 */
565static bool x86_has_numa_in_package;
566
567void 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 */
641const struct cpumask *cpu_coregroup_mask(int cpu)
642{
643 return cpu_llc_shared_mask(cpu);
644}
645
646static 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
665void __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
715static unsigned int init_udelay = UINT_MAX;
716
717static int __init cpu_init_udelay(char *str)
718{
719 get_option(&str, &init_udelay);
720
721 return 0;
722}
723early_param("cpu_init_udelay", cpu_init_udelay);
724
725static 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 */
747int
748wakeup_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
781static int
782wakeup_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 */
896static 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
932static 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 */
955static int
956wakeup_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
990out:
991 preempt_enable();
992
993 return boot_error;
994}
995
996int 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 */
1026static 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
1130int 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
1194unreg_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 */
1208void 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 */
1218static __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 */
1239static 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
1288static 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
1300static 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 */
1313void __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
1378void arch_thaw_secondary_cpus_begin(void)
1379{
1380 set_mtrr_aps_delayed_init();
1381}
1382
1383void arch_thaw_secondary_cpus_end(void)
1384{
1385 mtrr_aps_init();
1386}
1387
1388/*
1389 * Early setup to make printk work.
1390 */
1391void __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
1401void __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
1414void __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
1428static int __initdata setup_possible_cpus = -1;
1429static int __init _setup_possible_cpus(char *str)
1430{
1431 get_option(&str, &setup_possible_cpus);
1432 return 0;
1433}
1434early_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 */
1521static 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
1535static 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
1565static 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
1575void 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
1589int 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
1622int 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
1640void native_cpu_die(unsigned int cpu)
1641{
1642 common_cpu_die(cpu);
1643}
1644
1645void 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
1658static 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 */
1670static 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
1741void 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
1756void 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 */
1767int native_cpu_disable(void)
1768{
1769 return -ENOSYS;
1770}
1771
1772void native_cpu_die(unsigned int cpu)
1773{
1774 /* We said "no" in __cpu_disable */
1775 BUG();
1776}
1777
1778void 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
1820DEFINE_STATIC_KEY_FALSE(arch_scale_freq_key);
1821
1822static DEFINE_PER_CPU(u64, arch_prev_aperf);
1823static DEFINE_PER_CPU(u64, arch_prev_mperf);
1824static u64 arch_turbo_freq_ratio = SCHED_CAPACITY_SCALE;
1825static u64 arch_max_freq_ratio = SCHED_CAPACITY_SCALE;
1826
1827void 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
1833static 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
1845static 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
1870static 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
1876static const struct x86_cpu_id has_skx_turbo_ratio_limits[] = {
1877 X86_MATCH(SKYLAKE_X),
1878 {}
1879};
1880
1881static 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
1888static 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
1927static 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
1958static 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
1981static 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
2006out:
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
2030static 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
2041static 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
2066static void disable_freq_invariance_workfn(struct work_struct *work)
2067{
2068 static_branch_disable(&arch_scale_freq_key);
2069}
2070
2071static DECLARE_WORK(disable_freq_invariance_work,
2072 disable_freq_invariance_workfn);
2073
2074DEFINE_PER_CPU(unsigned long, arch_freq_scale) = SCHED_CAPACITY_SCALE;
2075
2076void 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
2110error:
2111 pr_warn("Scheduler frequency invariance went wobbly, disabling!\n");
2112 schedule_work(&disable_freq_invariance_work);
2113}
2114#else
2115static inline void init_freq_invariance(bool secondary)
2116{
2117}
2118#endif /* CONFIG_X86_64 */