xref: /linux/arch/x86/kernel/smpboot.c (revision e464640c)
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 #include <linux/stackprotector.h>
60 
61 #include <asm/acpi.h>
62 #include <asm/cacheinfo.h>
63 #include <asm/desc.h>
64 #include <asm/nmi.h>
65 #include <asm/irq.h>
66 #include <asm/realmode.h>
67 #include <asm/cpu.h>
68 #include <asm/numa.h>
69 #include <asm/tlbflush.h>
70 #include <asm/mtrr.h>
71 #include <asm/mwait.h>
72 #include <asm/apic.h>
73 #include <asm/io_apic.h>
74 #include <asm/fpu/api.h>
75 #include <asm/setup.h>
76 #include <asm/uv/uv.h>
77 #include <linux/mc146818rtc.h>
78 #include <asm/i8259.h>
79 #include <asm/misc.h>
80 #include <asm/qspinlock.h>
81 #include <asm/intel-family.h>
82 #include <asm/cpu_device_id.h>
83 #include <asm/spec-ctrl.h>
84 #include <asm/hw_irq.h>
85 #include <asm/stackprotector.h>
86 #include <asm/sev.h>
87 
88 /* representing HT siblings of each logical CPU */
89 DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);
90 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
91 
92 /* representing HT and core siblings of each logical CPU */
93 DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_map);
94 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
95 
96 /* representing HT, core, and die siblings of each logical CPU */
97 DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_die_map);
98 EXPORT_PER_CPU_SYMBOL(cpu_die_map);
99 
100 /* Per CPU bogomips and other parameters */
101 DEFINE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);
102 EXPORT_PER_CPU_SYMBOL(cpu_info);
103 
104 /* All of these masks are initialized in setup_cpu_local_masks() */
105 static cpumask_var_t cpu_initialized_mask;
106 static cpumask_var_t cpu_callout_mask;
107 /* Representing CPUs for which sibling maps can be computed */
108 static cpumask_var_t cpu_sibling_setup_mask;
109 
110 /* Logical package management. We might want to allocate that dynamically */
111 unsigned int __max_logical_packages __read_mostly;
112 EXPORT_SYMBOL(__max_logical_packages);
113 static unsigned int logical_packages __read_mostly;
114 static unsigned int logical_die __read_mostly;
115 
116 /* Maximum number of SMT threads on any online core */
117 int __read_mostly __max_smt_threads = 1;
118 
119 /* Flag to indicate if a complete sched domain rebuild is required */
120 bool x86_topology_update;
121 
122 int arch_update_cpu_topology(void)
123 {
124 	int retval = x86_topology_update;
125 
126 	x86_topology_update = false;
127 	return retval;
128 }
129 
130 
131 static unsigned int smpboot_warm_reset_vector_count;
132 
133 static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip)
134 {
135 	unsigned long flags;
136 
137 	spin_lock_irqsave(&rtc_lock, flags);
138 	if (!smpboot_warm_reset_vector_count++) {
139 		CMOS_WRITE(0xa, 0xf);
140 		*((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_HIGH)) = start_eip >> 4;
141 		*((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = start_eip & 0xf;
142 	}
143 	spin_unlock_irqrestore(&rtc_lock, flags);
144 }
145 
146 static inline void smpboot_restore_warm_reset_vector(void)
147 {
148 	unsigned long flags;
149 
150 	/*
151 	 * Paranoid:  Set warm reset code and vector here back
152 	 * to default values.
153 	 */
154 	spin_lock_irqsave(&rtc_lock, flags);
155 	if (!--smpboot_warm_reset_vector_count) {
156 		CMOS_WRITE(0, 0xf);
157 		*((volatile u32 *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = 0;
158 	}
159 	spin_unlock_irqrestore(&rtc_lock, flags);
160 
161 }
162 
163 /* Run the next set of setup steps for the upcoming CPU */
164 static void ap_starting(void)
165 {
166 	int cpuid = smp_processor_id();
167 
168 	/*
169 	 * If woken up by an INIT in an 82489DX configuration
170 	 * cpu_callout_mask guarantees the CPU does not reach this point
171 	 * before an INIT_deassert IPI reaches the local APIC, so it is now
172 	 * safe to touch the local APIC.
173 	 *
174 	 * Set up this CPU, first the APIC, which is probably redundant on
175 	 * most boards.
176 	 */
177 	apic_ap_setup();
178 
179 	/* Save the processor parameters. */
180 	smp_store_cpu_info(cpuid);
181 
182 	/*
183 	 * The topology information must be up to date before
184 	 * notify_cpu_starting().
185 	 */
186 	set_cpu_sibling_map(cpuid);
187 
188 	ap_init_aperfmperf();
189 
190 	pr_debug("Stack at about %p\n", &cpuid);
191 
192 	wmb();
193 
194 	/*
195 	 * This runs the AP through all the cpuhp states to its target
196 	 * state CPUHP_ONLINE.
197 	 */
198 	notify_cpu_starting(cpuid);
199 }
200 
201 static void ap_calibrate_delay(void)
202 {
203 	/*
204 	 * Calibrate the delay loop and update loops_per_jiffy in cpu_data.
205 	 * smp_store_cpu_info() stored a value that is close but not as
206 	 * accurate as the value just calculated.
207 	 *
208 	 * As this is invoked after the TSC synchronization check,
209 	 * calibrate_delay_is_known() will skip the calibration routine
210 	 * when TSC is synchronized across sockets.
211 	 */
212 	calibrate_delay();
213 	cpu_data(smp_processor_id()).loops_per_jiffy = loops_per_jiffy;
214 }
215 
216 static void wait_for_master_cpu(int cpu)
217 {
218 	/*
219 	 * Wait for release by control CPU before continuing with AP
220 	 * initialization.
221 	 */
222 	WARN_ON(cpumask_test_and_set_cpu(cpu, cpu_initialized_mask));
223 	while (!cpumask_test_cpu(cpu, cpu_callout_mask))
224 		cpu_relax();
225 }
226 
227 /*
228  * Activate a secondary processor.
229  */
230 static void notrace start_secondary(void *unused)
231 {
232 	/*
233 	 * Don't put *anything* except direct CPU state initialization
234 	 * before cpu_init(), SMP booting is too fragile that we want to
235 	 * limit the things done here to the most necessary things.
236 	 */
237 	cr4_init();
238 
239 #ifdef CONFIG_X86_32
240 	/* switch away from the initial page table */
241 	load_cr3(swapper_pg_dir);
242 	__flush_tlb_all();
243 #endif
244 	cpu_init_exception_handling();
245 
246 	/*
247 	 * Sync point with wait_cpu_initialized(). Sets AP in
248 	 * cpu_initialized_mask and then waits for the control CPU
249 	 * to release it.
250 	 */
251 	wait_for_master_cpu(raw_smp_processor_id());
252 
253 	cpu_init();
254 	rcu_cpu_starting(raw_smp_processor_id());
255 	x86_cpuinit.early_percpu_clock_init();
256 
257 	ap_starting();
258 
259 	/* Check TSC synchronization with the control CPU. */
260 	check_tsc_sync_target();
261 
262 	/*
263 	 * Calibrate the delay loop after the TSC synchronization check.
264 	 * This allows to skip the calibration when TSC is synchronized
265 	 * across sockets.
266 	 */
267 	ap_calibrate_delay();
268 
269 	speculative_store_bypass_ht_init();
270 
271 	/*
272 	 * Lock vector_lock, set CPU online and bring the vector
273 	 * allocator online. Online must be set with vector_lock held
274 	 * to prevent a concurrent irq setup/teardown from seeing a
275 	 * half valid vector space.
276 	 */
277 	lock_vector_lock();
278 	set_cpu_online(smp_processor_id(), true);
279 	lapic_online();
280 	unlock_vector_lock();
281 	cpu_set_state_online(smp_processor_id());
282 	x86_platform.nmi_init();
283 
284 	/* enable local interrupts */
285 	local_irq_enable();
286 
287 	x86_cpuinit.setup_percpu_clockev();
288 
289 	wmb();
290 	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
291 }
292 
293 /**
294  * topology_is_primary_thread - Check whether CPU is the primary SMT thread
295  * @cpu:	CPU to check
296  */
297 bool topology_is_primary_thread(unsigned int cpu)
298 {
299 	return apic_id_is_primary_thread(per_cpu(x86_cpu_to_apicid, cpu));
300 }
301 
302 /**
303  * topology_smt_supported - Check whether SMT is supported by the CPUs
304  */
305 bool topology_smt_supported(void)
306 {
307 	return smp_num_siblings > 1;
308 }
309 
310 /**
311  * topology_phys_to_logical_pkg - Map a physical package id to a logical
312  * @phys_pkg:	The physical package id to map
313  *
314  * Returns logical package id or -1 if not found
315  */
316 int topology_phys_to_logical_pkg(unsigned int phys_pkg)
317 {
318 	int cpu;
319 
320 	for_each_possible_cpu(cpu) {
321 		struct cpuinfo_x86 *c = &cpu_data(cpu);
322 
323 		if (c->initialized && c->phys_proc_id == phys_pkg)
324 			return c->logical_proc_id;
325 	}
326 	return -1;
327 }
328 EXPORT_SYMBOL(topology_phys_to_logical_pkg);
329 
330 /**
331  * topology_phys_to_logical_die - Map a physical die id to logical
332  * @die_id:	The physical die id to map
333  * @cur_cpu:	The CPU for which the mapping is done
334  *
335  * Returns logical die id or -1 if not found
336  */
337 static int topology_phys_to_logical_die(unsigned int die_id, unsigned int cur_cpu)
338 {
339 	int cpu, proc_id = cpu_data(cur_cpu).phys_proc_id;
340 
341 	for_each_possible_cpu(cpu) {
342 		struct cpuinfo_x86 *c = &cpu_data(cpu);
343 
344 		if (c->initialized && c->cpu_die_id == die_id &&
345 		    c->phys_proc_id == proc_id)
346 			return c->logical_die_id;
347 	}
348 	return -1;
349 }
350 
351 /**
352  * topology_update_package_map - Update the physical to logical package map
353  * @pkg:	The physical package id as retrieved via CPUID
354  * @cpu:	The cpu for which this is updated
355  */
356 int topology_update_package_map(unsigned int pkg, unsigned int cpu)
357 {
358 	int new;
359 
360 	/* Already available somewhere? */
361 	new = topology_phys_to_logical_pkg(pkg);
362 	if (new >= 0)
363 		goto found;
364 
365 	new = logical_packages++;
366 	if (new != pkg) {
367 		pr_info("CPU %u Converting physical %u to logical package %u\n",
368 			cpu, pkg, new);
369 	}
370 found:
371 	cpu_data(cpu).logical_proc_id = new;
372 	return 0;
373 }
374 /**
375  * topology_update_die_map - Update the physical to logical die map
376  * @die:	The die id as retrieved via CPUID
377  * @cpu:	The cpu for which this is updated
378  */
379 int topology_update_die_map(unsigned int die, unsigned int cpu)
380 {
381 	int new;
382 
383 	/* Already available somewhere? */
384 	new = topology_phys_to_logical_die(die, cpu);
385 	if (new >= 0)
386 		goto found;
387 
388 	new = logical_die++;
389 	if (new != die) {
390 		pr_info("CPU %u Converting physical %u to logical die %u\n",
391 			cpu, die, new);
392 	}
393 found:
394 	cpu_data(cpu).logical_die_id = new;
395 	return 0;
396 }
397 
398 void __init smp_store_boot_cpu_info(void)
399 {
400 	int id = 0; /* CPU 0 */
401 	struct cpuinfo_x86 *c = &cpu_data(id);
402 
403 	*c = boot_cpu_data;
404 	c->cpu_index = id;
405 	topology_update_package_map(c->phys_proc_id, id);
406 	topology_update_die_map(c->cpu_die_id, id);
407 	c->initialized = true;
408 }
409 
410 /*
411  * The bootstrap kernel entry code has set these up. Save them for
412  * a given CPU
413  */
414 void smp_store_cpu_info(int id)
415 {
416 	struct cpuinfo_x86 *c = &cpu_data(id);
417 
418 	/* Copy boot_cpu_data only on the first bringup */
419 	if (!c->initialized)
420 		*c = boot_cpu_data;
421 	c->cpu_index = id;
422 	/*
423 	 * During boot time, CPU0 has this setup already. Save the info when
424 	 * bringing up an AP.
425 	 */
426 	identify_secondary_cpu(c);
427 	c->initialized = true;
428 }
429 
430 static bool
431 topology_same_node(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
432 {
433 	int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
434 
435 	return (cpu_to_node(cpu1) == cpu_to_node(cpu2));
436 }
437 
438 static bool
439 topology_sane(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o, const char *name)
440 {
441 	int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
442 
443 	return !WARN_ONCE(!topology_same_node(c, o),
444 		"sched: CPU #%d's %s-sibling CPU #%d is not on the same node! "
445 		"[node: %d != %d]. Ignoring dependency.\n",
446 		cpu1, name, cpu2, cpu_to_node(cpu1), cpu_to_node(cpu2));
447 }
448 
449 #define link_mask(mfunc, c1, c2)					\
450 do {									\
451 	cpumask_set_cpu((c1), mfunc(c2));				\
452 	cpumask_set_cpu((c2), mfunc(c1));				\
453 } while (0)
454 
455 static bool match_smt(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
456 {
457 	if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
458 		int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
459 
460 		if (c->phys_proc_id == o->phys_proc_id &&
461 		    c->cpu_die_id == o->cpu_die_id &&
462 		    per_cpu(cpu_llc_id, cpu1) == per_cpu(cpu_llc_id, cpu2)) {
463 			if (c->cpu_core_id == o->cpu_core_id)
464 				return topology_sane(c, o, "smt");
465 
466 			if ((c->cu_id != 0xff) &&
467 			    (o->cu_id != 0xff) &&
468 			    (c->cu_id == o->cu_id))
469 				return topology_sane(c, o, "smt");
470 		}
471 
472 	} else if (c->phys_proc_id == o->phys_proc_id &&
473 		   c->cpu_die_id == o->cpu_die_id &&
474 		   c->cpu_core_id == o->cpu_core_id) {
475 		return topology_sane(c, o, "smt");
476 	}
477 
478 	return false;
479 }
480 
481 static bool match_die(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
482 {
483 	if (c->phys_proc_id == o->phys_proc_id &&
484 	    c->cpu_die_id == o->cpu_die_id)
485 		return true;
486 	return false;
487 }
488 
489 static bool match_l2c(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
490 {
491 	int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
492 
493 	/* If the arch didn't set up l2c_id, fall back to SMT */
494 	if (per_cpu(cpu_l2c_id, cpu1) == BAD_APICID)
495 		return match_smt(c, o);
496 
497 	/* Do not match if L2 cache id does not match: */
498 	if (per_cpu(cpu_l2c_id, cpu1) != per_cpu(cpu_l2c_id, cpu2))
499 		return false;
500 
501 	return topology_sane(c, o, "l2c");
502 }
503 
504 /*
505  * Unlike the other levels, we do not enforce keeping a
506  * multicore group inside a NUMA node.  If this happens, we will
507  * discard the MC level of the topology later.
508  */
509 static bool match_pkg(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
510 {
511 	if (c->phys_proc_id == o->phys_proc_id)
512 		return true;
513 	return false;
514 }
515 
516 /*
517  * Define intel_cod_cpu[] for Intel COD (Cluster-on-Die) CPUs.
518  *
519  * Any Intel CPU that has multiple nodes per package and does not
520  * match intel_cod_cpu[] has the SNC (Sub-NUMA Cluster) topology.
521  *
522  * When in SNC mode, these CPUs enumerate an LLC that is shared
523  * by multiple NUMA nodes. The LLC is shared for off-package data
524  * access but private to the NUMA node (half of the package) for
525  * on-package access. CPUID (the source of the information about
526  * the LLC) can only enumerate the cache as shared or unshared,
527  * but not this particular configuration.
528  */
529 
530 static const struct x86_cpu_id intel_cod_cpu[] = {
531 	X86_MATCH_INTEL_FAM6_MODEL(HASWELL_X, 0),	/* COD */
532 	X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_X, 0),	/* COD */
533 	X86_MATCH_INTEL_FAM6_MODEL(ANY, 1),		/* SNC */
534 	{}
535 };
536 
537 static bool match_llc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
538 {
539 	const struct x86_cpu_id *id = x86_match_cpu(intel_cod_cpu);
540 	int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
541 	bool intel_snc = id && id->driver_data;
542 
543 	/* Do not match if we do not have a valid APICID for cpu: */
544 	if (per_cpu(cpu_llc_id, cpu1) == BAD_APICID)
545 		return false;
546 
547 	/* Do not match if LLC id does not match: */
548 	if (per_cpu(cpu_llc_id, cpu1) != per_cpu(cpu_llc_id, cpu2))
549 		return false;
550 
551 	/*
552 	 * Allow the SNC topology without warning. Return of false
553 	 * means 'c' does not share the LLC of 'o'. This will be
554 	 * reflected to userspace.
555 	 */
556 	if (match_pkg(c, o) && !topology_same_node(c, o) && intel_snc)
557 		return false;
558 
559 	return topology_sane(c, o, "llc");
560 }
561 
562 
563 #if defined(CONFIG_SCHED_SMT) || defined(CONFIG_SCHED_CLUSTER) || defined(CONFIG_SCHED_MC)
564 static inline int x86_sched_itmt_flags(void)
565 {
566 	return sysctl_sched_itmt_enabled ? SD_ASYM_PACKING : 0;
567 }
568 
569 #ifdef CONFIG_SCHED_MC
570 static int x86_core_flags(void)
571 {
572 	return cpu_core_flags() | x86_sched_itmt_flags();
573 }
574 #endif
575 #ifdef CONFIG_SCHED_SMT
576 static int x86_smt_flags(void)
577 {
578 	return cpu_smt_flags() | x86_sched_itmt_flags();
579 }
580 #endif
581 #ifdef CONFIG_SCHED_CLUSTER
582 static int x86_cluster_flags(void)
583 {
584 	return cpu_cluster_flags() | x86_sched_itmt_flags();
585 }
586 #endif
587 #endif
588 
589 static struct sched_domain_topology_level x86_numa_in_package_topology[] = {
590 #ifdef CONFIG_SCHED_SMT
591 	{ cpu_smt_mask, x86_smt_flags, SD_INIT_NAME(SMT) },
592 #endif
593 #ifdef CONFIG_SCHED_CLUSTER
594 	{ cpu_clustergroup_mask, x86_cluster_flags, SD_INIT_NAME(CLS) },
595 #endif
596 #ifdef CONFIG_SCHED_MC
597 	{ cpu_coregroup_mask, x86_core_flags, SD_INIT_NAME(MC) },
598 #endif
599 	{ NULL, },
600 };
601 
602 static struct sched_domain_topology_level x86_hybrid_topology[] = {
603 #ifdef CONFIG_SCHED_SMT
604 	{ cpu_smt_mask, x86_smt_flags, SD_INIT_NAME(SMT) },
605 #endif
606 #ifdef CONFIG_SCHED_MC
607 	{ cpu_coregroup_mask, x86_core_flags, SD_INIT_NAME(MC) },
608 #endif
609 	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
610 	{ NULL, },
611 };
612 
613 static struct sched_domain_topology_level x86_topology[] = {
614 #ifdef CONFIG_SCHED_SMT
615 	{ cpu_smt_mask, x86_smt_flags, SD_INIT_NAME(SMT) },
616 #endif
617 #ifdef CONFIG_SCHED_CLUSTER
618 	{ cpu_clustergroup_mask, x86_cluster_flags, SD_INIT_NAME(CLS) },
619 #endif
620 #ifdef CONFIG_SCHED_MC
621 	{ cpu_coregroup_mask, x86_core_flags, SD_INIT_NAME(MC) },
622 #endif
623 	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
624 	{ NULL, },
625 };
626 
627 /*
628  * Set if a package/die has multiple NUMA nodes inside.
629  * AMD Magny-Cours, Intel Cluster-on-Die, and Intel
630  * Sub-NUMA Clustering have this.
631  */
632 static bool x86_has_numa_in_package;
633 
634 void set_cpu_sibling_map(int cpu)
635 {
636 	bool has_smt = smp_num_siblings > 1;
637 	bool has_mp = has_smt || boot_cpu_data.x86_max_cores > 1;
638 	struct cpuinfo_x86 *c = &cpu_data(cpu);
639 	struct cpuinfo_x86 *o;
640 	int i, threads;
641 
642 	cpumask_set_cpu(cpu, cpu_sibling_setup_mask);
643 
644 	if (!has_mp) {
645 		cpumask_set_cpu(cpu, topology_sibling_cpumask(cpu));
646 		cpumask_set_cpu(cpu, cpu_llc_shared_mask(cpu));
647 		cpumask_set_cpu(cpu, cpu_l2c_shared_mask(cpu));
648 		cpumask_set_cpu(cpu, topology_core_cpumask(cpu));
649 		cpumask_set_cpu(cpu, topology_die_cpumask(cpu));
650 		c->booted_cores = 1;
651 		return;
652 	}
653 
654 	for_each_cpu(i, cpu_sibling_setup_mask) {
655 		o = &cpu_data(i);
656 
657 		if (match_pkg(c, o) && !topology_same_node(c, o))
658 			x86_has_numa_in_package = true;
659 
660 		if ((i == cpu) || (has_smt && match_smt(c, o)))
661 			link_mask(topology_sibling_cpumask, cpu, i);
662 
663 		if ((i == cpu) || (has_mp && match_llc(c, o)))
664 			link_mask(cpu_llc_shared_mask, cpu, i);
665 
666 		if ((i == cpu) || (has_mp && match_l2c(c, o)))
667 			link_mask(cpu_l2c_shared_mask, cpu, i);
668 
669 		if ((i == cpu) || (has_mp && match_die(c, o)))
670 			link_mask(topology_die_cpumask, cpu, i);
671 	}
672 
673 	threads = cpumask_weight(topology_sibling_cpumask(cpu));
674 	if (threads > __max_smt_threads)
675 		__max_smt_threads = threads;
676 
677 	for_each_cpu(i, topology_sibling_cpumask(cpu))
678 		cpu_data(i).smt_active = threads > 1;
679 
680 	/*
681 	 * This needs a separate iteration over the cpus because we rely on all
682 	 * topology_sibling_cpumask links to be set-up.
683 	 */
684 	for_each_cpu(i, cpu_sibling_setup_mask) {
685 		o = &cpu_data(i);
686 
687 		if ((i == cpu) || (has_mp && match_pkg(c, o))) {
688 			link_mask(topology_core_cpumask, cpu, i);
689 
690 			/*
691 			 *  Does this new cpu bringup a new core?
692 			 */
693 			if (threads == 1) {
694 				/*
695 				 * for each core in package, increment
696 				 * the booted_cores for this new cpu
697 				 */
698 				if (cpumask_first(
699 				    topology_sibling_cpumask(i)) == i)
700 					c->booted_cores++;
701 				/*
702 				 * increment the core count for all
703 				 * the other cpus in this package
704 				 */
705 				if (i != cpu)
706 					cpu_data(i).booted_cores++;
707 			} else if (i != cpu && !c->booted_cores)
708 				c->booted_cores = cpu_data(i).booted_cores;
709 		}
710 	}
711 }
712 
713 /* maps the cpu to the sched domain representing multi-core */
714 const struct cpumask *cpu_coregroup_mask(int cpu)
715 {
716 	return cpu_llc_shared_mask(cpu);
717 }
718 
719 const struct cpumask *cpu_clustergroup_mask(int cpu)
720 {
721 	return cpu_l2c_shared_mask(cpu);
722 }
723 
724 static void impress_friends(void)
725 {
726 	int cpu;
727 	unsigned long bogosum = 0;
728 	/*
729 	 * Allow the user to impress friends.
730 	 */
731 	pr_debug("Before bogomips\n");
732 	for_each_possible_cpu(cpu)
733 		if (cpumask_test_cpu(cpu, cpu_callout_mask))
734 			bogosum += cpu_data(cpu).loops_per_jiffy;
735 	pr_info("Total of %d processors activated (%lu.%02lu BogoMIPS)\n",
736 		num_online_cpus(),
737 		bogosum/(500000/HZ),
738 		(bogosum/(5000/HZ))%100);
739 
740 	pr_debug("Before bogocount - setting activated=1\n");
741 }
742 
743 void __inquire_remote_apic(int apicid)
744 {
745 	unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
746 	const char * const names[] = { "ID", "VERSION", "SPIV" };
747 	int timeout;
748 	u32 status;
749 
750 	pr_info("Inquiring remote APIC 0x%x...\n", apicid);
751 
752 	for (i = 0; i < ARRAY_SIZE(regs); i++) {
753 		pr_info("... APIC 0x%x %s: ", apicid, names[i]);
754 
755 		/*
756 		 * Wait for idle.
757 		 */
758 		status = safe_apic_wait_icr_idle();
759 		if (status)
760 			pr_cont("a previous APIC delivery may have failed\n");
761 
762 		apic_icr_write(APIC_DM_REMRD | regs[i], apicid);
763 
764 		timeout = 0;
765 		do {
766 			udelay(100);
767 			status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK;
768 		} while (status == APIC_ICR_RR_INPROG && timeout++ < 1000);
769 
770 		switch (status) {
771 		case APIC_ICR_RR_VALID:
772 			status = apic_read(APIC_RRR);
773 			pr_cont("%08x\n", status);
774 			break;
775 		default:
776 			pr_cont("failed\n");
777 		}
778 	}
779 }
780 
781 /*
782  * The Multiprocessor Specification 1.4 (1997) example code suggests
783  * that there should be a 10ms delay between the BSP asserting INIT
784  * and de-asserting INIT, when starting a remote processor.
785  * But that slows boot and resume on modern processors, which include
786  * many cores and don't require that delay.
787  *
788  * Cmdline "init_cpu_udelay=" is available to over-ride this delay.
789  * Modern processor families are quirked to remove the delay entirely.
790  */
791 #define UDELAY_10MS_DEFAULT 10000
792 
793 static unsigned int init_udelay = UINT_MAX;
794 
795 static int __init cpu_init_udelay(char *str)
796 {
797 	get_option(&str, &init_udelay);
798 
799 	return 0;
800 }
801 early_param("cpu_init_udelay", cpu_init_udelay);
802 
803 static void __init smp_quirk_init_udelay(void)
804 {
805 	/* if cmdline changed it from default, leave it alone */
806 	if (init_udelay != UINT_MAX)
807 		return;
808 
809 	/* if modern processor, use no delay */
810 	if (((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && (boot_cpu_data.x86 == 6)) ||
811 	    ((boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) && (boot_cpu_data.x86 >= 0x18)) ||
812 	    ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && (boot_cpu_data.x86 >= 0xF))) {
813 		init_udelay = 0;
814 		return;
815 	}
816 	/* else, use legacy delay */
817 	init_udelay = UDELAY_10MS_DEFAULT;
818 }
819 
820 /*
821  * Wake up AP by INIT, INIT, STARTUP sequence.
822  */
823 static int wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)
824 {
825 	unsigned long send_status = 0, accept_status = 0;
826 	int maxlvt, num_starts, j;
827 
828 	preempt_disable();
829 	maxlvt = lapic_get_maxlvt();
830 
831 	/*
832 	 * Be paranoid about clearing APIC errors.
833 	 */
834 	if (APIC_INTEGRATED(boot_cpu_apic_version)) {
835 		if (maxlvt > 3)		/* Due to the Pentium erratum 3AP.  */
836 			apic_write(APIC_ESR, 0);
837 		apic_read(APIC_ESR);
838 	}
839 
840 	pr_debug("Asserting INIT\n");
841 
842 	/*
843 	 * Turn INIT on target chip
844 	 */
845 	/*
846 	 * Send IPI
847 	 */
848 	apic_icr_write(APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT,
849 		       phys_apicid);
850 
851 	pr_debug("Waiting for send to finish...\n");
852 	send_status = safe_apic_wait_icr_idle();
853 
854 	udelay(init_udelay);
855 
856 	pr_debug("Deasserting INIT\n");
857 
858 	/* Target chip */
859 	/* Send IPI */
860 	apic_icr_write(APIC_INT_LEVELTRIG | APIC_DM_INIT, phys_apicid);
861 
862 	pr_debug("Waiting for send to finish...\n");
863 	send_status = safe_apic_wait_icr_idle();
864 
865 	mb();
866 
867 	/*
868 	 * Should we send STARTUP IPIs ?
869 	 *
870 	 * Determine this based on the APIC version.
871 	 * If we don't have an integrated APIC, don't send the STARTUP IPIs.
872 	 */
873 	if (APIC_INTEGRATED(boot_cpu_apic_version))
874 		num_starts = 2;
875 	else
876 		num_starts = 0;
877 
878 	/*
879 	 * Run STARTUP IPI loop.
880 	 */
881 	pr_debug("#startup loops: %d\n", num_starts);
882 
883 	for (j = 1; j <= num_starts; j++) {
884 		pr_debug("Sending STARTUP #%d\n", j);
885 		if (maxlvt > 3)		/* Due to the Pentium erratum 3AP.  */
886 			apic_write(APIC_ESR, 0);
887 		apic_read(APIC_ESR);
888 		pr_debug("After apic_write\n");
889 
890 		/*
891 		 * STARTUP IPI
892 		 */
893 
894 		/* Target chip */
895 		/* Boot on the stack */
896 		/* Kick the second */
897 		apic_icr_write(APIC_DM_STARTUP | (start_eip >> 12),
898 			       phys_apicid);
899 
900 		/*
901 		 * Give the other CPU some time to accept the IPI.
902 		 */
903 		if (init_udelay == 0)
904 			udelay(10);
905 		else
906 			udelay(300);
907 
908 		pr_debug("Startup point 1\n");
909 
910 		pr_debug("Waiting for send to finish...\n");
911 		send_status = safe_apic_wait_icr_idle();
912 
913 		/*
914 		 * Give the other CPU some time to accept the IPI.
915 		 */
916 		if (init_udelay == 0)
917 			udelay(10);
918 		else
919 			udelay(200);
920 
921 		if (maxlvt > 3)		/* Due to the Pentium erratum 3AP.  */
922 			apic_write(APIC_ESR, 0);
923 		accept_status = (apic_read(APIC_ESR) & 0xEF);
924 		if (send_status || accept_status)
925 			break;
926 	}
927 	pr_debug("After Startup\n");
928 
929 	if (send_status)
930 		pr_err("APIC never delivered???\n");
931 	if (accept_status)
932 		pr_err("APIC delivery error (%lx)\n", accept_status);
933 
934 	preempt_enable();
935 	return (send_status | accept_status);
936 }
937 
938 /* reduce the number of lines printed when booting a large cpu count system */
939 static void announce_cpu(int cpu, int apicid)
940 {
941 	static int current_node = NUMA_NO_NODE;
942 	int node = early_cpu_to_node(cpu);
943 	static int width, node_width;
944 
945 	if (!width)
946 		width = num_digits(num_possible_cpus()) + 1; /* + '#' sign */
947 
948 	if (!node_width)
949 		node_width = num_digits(num_possible_nodes()) + 1; /* + '#' */
950 
951 	if (cpu == 1)
952 		printk(KERN_INFO "x86: Booting SMP configuration:\n");
953 
954 	if (system_state < SYSTEM_RUNNING) {
955 		if (node != current_node) {
956 			if (current_node > (-1))
957 				pr_cont("\n");
958 			current_node = node;
959 
960 			printk(KERN_INFO ".... node %*s#%d, CPUs:  ",
961 			       node_width - num_digits(node), " ", node);
962 		}
963 
964 		/* Add padding for the BSP */
965 		if (cpu == 1)
966 			pr_cont("%*s", width + 1, " ");
967 
968 		pr_cont("%*s#%d", width - num_digits(cpu), " ", cpu);
969 
970 	} else
971 		pr_info("Booting Node %d Processor %d APIC 0x%x\n",
972 			node, cpu, apicid);
973 }
974 
975 int common_cpu_up(unsigned int cpu, struct task_struct *idle)
976 {
977 	int ret;
978 
979 	/* Just in case we booted with a single CPU. */
980 	alternatives_enable_smp();
981 
982 	per_cpu(pcpu_hot.current_task, cpu) = idle;
983 	cpu_init_stack_canary(cpu, idle);
984 
985 	/* Initialize the interrupt stack(s) */
986 	ret = irq_init_percpu_irqstack(cpu);
987 	if (ret)
988 		return ret;
989 
990 #ifdef CONFIG_X86_32
991 	/* Stack for startup_32 can be just as for start_secondary onwards */
992 	per_cpu(pcpu_hot.top_of_stack, cpu) = task_top_of_stack(idle);
993 #endif
994 	return 0;
995 }
996 
997 /*
998  * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
999  * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
1000  * Returns zero if startup was successfully sent, else error code from
1001  * ->wakeup_secondary_cpu.
1002  */
1003 static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
1004 {
1005 	unsigned long start_ip = real_mode_header->trampoline_start;
1006 
1007 #ifdef CONFIG_X86_64
1008 	/* If 64-bit wakeup method exists, use the 64-bit mode trampoline IP */
1009 	if (apic->wakeup_secondary_cpu_64)
1010 		start_ip = real_mode_header->trampoline_start64;
1011 #endif
1012 	idle->thread.sp = (unsigned long)task_pt_regs(idle);
1013 	initial_code = (unsigned long)start_secondary;
1014 
1015 	if (IS_ENABLED(CONFIG_X86_32)) {
1016 		early_gdt_descr.address = (unsigned long)get_cpu_gdt_rw(cpu);
1017 		initial_stack  = idle->thread.sp;
1018 	} else {
1019 		smpboot_control = cpu;
1020 	}
1021 
1022 	/* Enable the espfix hack for this CPU */
1023 	init_espfix_ap(cpu);
1024 
1025 	/* So we see what's up */
1026 	announce_cpu(cpu, apicid);
1027 
1028 	/*
1029 	 * This grunge runs the startup process for
1030 	 * the targeted processor.
1031 	 */
1032 	if (x86_platform.legacy.warm_reset) {
1033 
1034 		pr_debug("Setting warm reset code and vector.\n");
1035 
1036 		smpboot_setup_warm_reset_vector(start_ip);
1037 		/*
1038 		 * Be paranoid about clearing APIC errors.
1039 		*/
1040 		if (APIC_INTEGRATED(boot_cpu_apic_version)) {
1041 			apic_write(APIC_ESR, 0);
1042 			apic_read(APIC_ESR);
1043 		}
1044 	}
1045 
1046 	/*
1047 	 * AP might wait on cpu_callout_mask in cpu_init() with
1048 	 * cpu_initialized_mask set if previous attempt to online
1049 	 * it timed-out. Clear cpu_initialized_mask so that after
1050 	 * INIT/SIPI it could start with a clean state.
1051 	 */
1052 	cpumask_clear_cpu(cpu, cpu_initialized_mask);
1053 	smp_mb();
1054 
1055 	/*
1056 	 * Wake up a CPU in difference cases:
1057 	 * - Use a method from the APIC driver if one defined, with wakeup
1058 	 *   straight to 64-bit mode preferred over wakeup to RM.
1059 	 * Otherwise,
1060 	 * - Use an INIT boot APIC message
1061 	 */
1062 	if (apic->wakeup_secondary_cpu_64)
1063 		return apic->wakeup_secondary_cpu_64(apicid, start_ip);
1064 	else if (apic->wakeup_secondary_cpu)
1065 		return apic->wakeup_secondary_cpu(apicid, start_ip);
1066 
1067 	return wakeup_secondary_cpu_via_init(apicid, start_ip);
1068 }
1069 
1070 static int wait_cpu_cpumask(unsigned int cpu, const struct cpumask *mask)
1071 {
1072 	unsigned long timeout;
1073 
1074 	/*
1075 	 * Wait up to 10s for the CPU to report in.
1076 	 */
1077 	timeout = jiffies + 10*HZ;
1078 	while (time_before(jiffies, timeout)) {
1079 		if (cpumask_test_cpu(cpu, mask))
1080 			return 0;
1081 
1082 		schedule();
1083 	}
1084 	return -1;
1085 }
1086 
1087 /*
1088  * Bringup step two: Wait for the target AP to reach cpu_init_secondary()
1089  * and thus wait_for_master_cpu(), then set cpu_callout_mask to allow it
1090  * to proceed.  The AP will then proceed past setting its 'callin' bit
1091  * and end up waiting in check_tsc_sync_target() until we reach
1092  * wait_cpu_online() to tend to it.
1093  */
1094 static int wait_cpu_initialized(unsigned int cpu)
1095 {
1096 	/*
1097 	 * Wait for first sign of life from AP.
1098 	 */
1099 	if (wait_cpu_cpumask(cpu, cpu_initialized_mask))
1100 		return -1;
1101 
1102 	cpumask_set_cpu(cpu, cpu_callout_mask);
1103 	return 0;
1104 }
1105 
1106 static int native_kick_ap(unsigned int cpu, struct task_struct *tidle)
1107 {
1108 	int apicid = apic->cpu_present_to_apicid(cpu);
1109 	int err;
1110 
1111 	lockdep_assert_irqs_enabled();
1112 
1113 	pr_debug("++++++++++++++++++++=_---CPU UP  %u\n", cpu);
1114 
1115 	if (apicid == BAD_APICID ||
1116 	    !physid_isset(apicid, phys_cpu_present_map) ||
1117 	    !apic->apic_id_valid(apicid)) {
1118 		pr_err("%s: bad cpu %d\n", __func__, cpu);
1119 		return -EINVAL;
1120 	}
1121 
1122 	/*
1123 	 * Save current MTRR state in case it was changed since early boot
1124 	 * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
1125 	 */
1126 	mtrr_save_state();
1127 
1128 	/* x86 CPUs take themselves offline, so delayed offline is OK. */
1129 	err = cpu_check_up_prepare(cpu);
1130 	if (err && err != -EBUSY)
1131 		return err;
1132 
1133 	/* the FPU context is blank, nobody can own it */
1134 	per_cpu(fpu_fpregs_owner_ctx, cpu) = NULL;
1135 
1136 	err = common_cpu_up(cpu, tidle);
1137 	if (err)
1138 		return err;
1139 
1140 	err = do_boot_cpu(apicid, cpu, tidle);
1141 	if (err)
1142 		pr_err("do_boot_cpu failed(%d) to wakeup CPU#%u\n", err, cpu);
1143 
1144 	return err;
1145 }
1146 
1147 int native_cpu_up(unsigned int cpu, struct task_struct *tidle)
1148 {
1149 	int ret;
1150 
1151 	ret = native_kick_ap(cpu, tidle);
1152 	if (!ret)
1153 		ret = wait_cpu_initialized(cpu);
1154 
1155 	/* Cleanup possible dangling ends... */
1156 	if (x86_platform.legacy.warm_reset)
1157 		smpboot_restore_warm_reset_vector();
1158 
1159 	return ret;
1160 }
1161 
1162 /**
1163  * arch_disable_smp_support() - Disables SMP support for x86 at boottime
1164  */
1165 void __init arch_disable_smp_support(void)
1166 {
1167 	disable_ioapic_support();
1168 }
1169 
1170 /*
1171  * Fall back to non SMP mode after errors.
1172  *
1173  * RED-PEN audit/test this more. I bet there is more state messed up here.
1174  */
1175 static __init void disable_smp(void)
1176 {
1177 	pr_info("SMP disabled\n");
1178 
1179 	disable_ioapic_support();
1180 
1181 	init_cpu_present(cpumask_of(0));
1182 	init_cpu_possible(cpumask_of(0));
1183 
1184 	if (smp_found_config)
1185 		physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
1186 	else
1187 		physid_set_mask_of_physid(0, &phys_cpu_present_map);
1188 	cpumask_set_cpu(0, topology_sibling_cpumask(0));
1189 	cpumask_set_cpu(0, topology_core_cpumask(0));
1190 	cpumask_set_cpu(0, topology_die_cpumask(0));
1191 }
1192 
1193 /*
1194  * Various sanity checks.
1195  */
1196 static void __init smp_sanity_check(void)
1197 {
1198 	preempt_disable();
1199 
1200 #if !defined(CONFIG_X86_BIGSMP) && defined(CONFIG_X86_32)
1201 	if (def_to_bigsmp && nr_cpu_ids > 8) {
1202 		unsigned int cpu;
1203 		unsigned nr;
1204 
1205 		pr_warn("More than 8 CPUs detected - skipping them\n"
1206 			"Use CONFIG_X86_BIGSMP\n");
1207 
1208 		nr = 0;
1209 		for_each_present_cpu(cpu) {
1210 			if (nr >= 8)
1211 				set_cpu_present(cpu, false);
1212 			nr++;
1213 		}
1214 
1215 		nr = 0;
1216 		for_each_possible_cpu(cpu) {
1217 			if (nr >= 8)
1218 				set_cpu_possible(cpu, false);
1219 			nr++;
1220 		}
1221 
1222 		set_nr_cpu_ids(8);
1223 	}
1224 #endif
1225 
1226 	if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
1227 		pr_warn("weird, boot CPU (#%d) not listed by the BIOS\n",
1228 			hard_smp_processor_id());
1229 
1230 		physid_set(hard_smp_processor_id(), phys_cpu_present_map);
1231 	}
1232 
1233 	/*
1234 	 * Should not be necessary because the MP table should list the boot
1235 	 * CPU too, but we do it for the sake of robustness anyway.
1236 	 */
1237 	if (!apic->check_phys_apicid_present(boot_cpu_physical_apicid)) {
1238 		pr_notice("weird, boot CPU (#%d) not listed by the BIOS\n",
1239 			  boot_cpu_physical_apicid);
1240 		physid_set(hard_smp_processor_id(), phys_cpu_present_map);
1241 	}
1242 	preempt_enable();
1243 }
1244 
1245 static void __init smp_cpu_index_default(void)
1246 {
1247 	int i;
1248 	struct cpuinfo_x86 *c;
1249 
1250 	for_each_possible_cpu(i) {
1251 		c = &cpu_data(i);
1252 		/* mark all to hotplug */
1253 		c->cpu_index = nr_cpu_ids;
1254 	}
1255 }
1256 
1257 void __init smp_prepare_cpus_common(void)
1258 {
1259 	unsigned int i;
1260 
1261 	smp_cpu_index_default();
1262 
1263 	/*
1264 	 * Setup boot CPU information
1265 	 */
1266 	smp_store_boot_cpu_info(); /* Final full version of the data */
1267 	mb();
1268 
1269 	for_each_possible_cpu(i) {
1270 		zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
1271 		zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
1272 		zalloc_cpumask_var(&per_cpu(cpu_die_map, i), GFP_KERNEL);
1273 		zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL);
1274 		zalloc_cpumask_var(&per_cpu(cpu_l2c_shared_map, i), GFP_KERNEL);
1275 	}
1276 
1277 	/*
1278 	 * Set 'default' x86 topology, this matches default_topology() in that
1279 	 * it has NUMA nodes as a topology level. See also
1280 	 * native_smp_cpus_done().
1281 	 *
1282 	 * Must be done before set_cpus_sibling_map() is ran.
1283 	 */
1284 	set_sched_topology(x86_topology);
1285 
1286 	set_cpu_sibling_map(0);
1287 }
1288 
1289 /*
1290  * Prepare for SMP bootup.
1291  * @max_cpus: configured maximum number of CPUs, It is a legacy parameter
1292  *            for common interface support.
1293  */
1294 void __init native_smp_prepare_cpus(unsigned int max_cpus)
1295 {
1296 	smp_prepare_cpus_common();
1297 
1298 	smp_sanity_check();
1299 
1300 	switch (apic_intr_mode) {
1301 	case APIC_PIC:
1302 	case APIC_VIRTUAL_WIRE_NO_CONFIG:
1303 		disable_smp();
1304 		return;
1305 	case APIC_SYMMETRIC_IO_NO_ROUTING:
1306 		disable_smp();
1307 		/* Setup local timer */
1308 		x86_init.timers.setup_percpu_clockev();
1309 		return;
1310 	case APIC_VIRTUAL_WIRE:
1311 	case APIC_SYMMETRIC_IO:
1312 		break;
1313 	}
1314 
1315 	/* Setup local timer */
1316 	x86_init.timers.setup_percpu_clockev();
1317 
1318 	pr_info("CPU0: ");
1319 	print_cpu_info(&cpu_data(0));
1320 
1321 	uv_system_init();
1322 
1323 	smp_quirk_init_udelay();
1324 
1325 	speculative_store_bypass_ht_init();
1326 
1327 	snp_set_wakeup_secondary_cpu();
1328 }
1329 
1330 void arch_thaw_secondary_cpus_begin(void)
1331 {
1332 	set_cache_aps_delayed_init(true);
1333 }
1334 
1335 void arch_thaw_secondary_cpus_end(void)
1336 {
1337 	cache_aps_init();
1338 }
1339 
1340 /*
1341  * Early setup to make printk work.
1342  */
1343 void __init native_smp_prepare_boot_cpu(void)
1344 {
1345 	int me = smp_processor_id();
1346 
1347 	/* SMP handles this from setup_per_cpu_areas() */
1348 	if (!IS_ENABLED(CONFIG_SMP))
1349 		switch_gdt_and_percpu_base(me);
1350 
1351 	/* already set me in cpu_online_mask in boot_cpu_init() */
1352 	cpumask_set_cpu(me, cpu_callout_mask);
1353 	cpu_set_state_online(me);
1354 	native_pv_lock_init();
1355 }
1356 
1357 void __init calculate_max_logical_packages(void)
1358 {
1359 	int ncpus;
1360 
1361 	/*
1362 	 * Today neither Intel nor AMD support heterogeneous systems so
1363 	 * extrapolate the boot cpu's data to all packages.
1364 	 */
1365 	ncpus = cpu_data(0).booted_cores * topology_max_smt_threads();
1366 	__max_logical_packages = DIV_ROUND_UP(total_cpus, ncpus);
1367 	pr_info("Max logical packages: %u\n", __max_logical_packages);
1368 }
1369 
1370 void __init native_smp_cpus_done(unsigned int max_cpus)
1371 {
1372 	pr_debug("Boot done\n");
1373 
1374 	calculate_max_logical_packages();
1375 
1376 	/* XXX for now assume numa-in-package and hybrid don't overlap */
1377 	if (x86_has_numa_in_package)
1378 		set_sched_topology(x86_numa_in_package_topology);
1379 	if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))
1380 		set_sched_topology(x86_hybrid_topology);
1381 
1382 	nmi_selftest();
1383 	impress_friends();
1384 	cache_aps_init();
1385 }
1386 
1387 static int __initdata setup_possible_cpus = -1;
1388 static int __init _setup_possible_cpus(char *str)
1389 {
1390 	get_option(&str, &setup_possible_cpus);
1391 	return 0;
1392 }
1393 early_param("possible_cpus", _setup_possible_cpus);
1394 
1395 
1396 /*
1397  * cpu_possible_mask should be static, it cannot change as cpu's
1398  * are onlined, or offlined. The reason is per-cpu data-structures
1399  * are allocated by some modules at init time, and don't expect to
1400  * do this dynamically on cpu arrival/departure.
1401  * cpu_present_mask on the other hand can change dynamically.
1402  * In case when cpu_hotplug is not compiled, then we resort to current
1403  * behaviour, which is cpu_possible == cpu_present.
1404  * - Ashok Raj
1405  *
1406  * Three ways to find out the number of additional hotplug CPUs:
1407  * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
1408  * - The user can overwrite it with possible_cpus=NUM
1409  * - Otherwise don't reserve additional CPUs.
1410  * We do this because additional CPUs waste a lot of memory.
1411  * -AK
1412  */
1413 __init void prefill_possible_map(void)
1414 {
1415 	int i, possible;
1416 
1417 	/* No boot processor was found in mptable or ACPI MADT */
1418 	if (!num_processors) {
1419 		if (boot_cpu_has(X86_FEATURE_APIC)) {
1420 			int apicid = boot_cpu_physical_apicid;
1421 			int cpu = hard_smp_processor_id();
1422 
1423 			pr_warn("Boot CPU (id %d) not listed by BIOS\n", cpu);
1424 
1425 			/* Make sure boot cpu is enumerated */
1426 			if (apic->cpu_present_to_apicid(0) == BAD_APICID &&
1427 			    apic->apic_id_valid(apicid))
1428 				generic_processor_info(apicid, boot_cpu_apic_version);
1429 		}
1430 
1431 		if (!num_processors)
1432 			num_processors = 1;
1433 	}
1434 
1435 	i = setup_max_cpus ?: 1;
1436 	if (setup_possible_cpus == -1) {
1437 		possible = num_processors;
1438 #ifdef CONFIG_HOTPLUG_CPU
1439 		if (setup_max_cpus)
1440 			possible += disabled_cpus;
1441 #else
1442 		if (possible > i)
1443 			possible = i;
1444 #endif
1445 	} else
1446 		possible = setup_possible_cpus;
1447 
1448 	total_cpus = max_t(int, possible, num_processors + disabled_cpus);
1449 
1450 	/* nr_cpu_ids could be reduced via nr_cpus= */
1451 	if (possible > nr_cpu_ids) {
1452 		pr_warn("%d Processors exceeds NR_CPUS limit of %u\n",
1453 			possible, nr_cpu_ids);
1454 		possible = nr_cpu_ids;
1455 	}
1456 
1457 #ifdef CONFIG_HOTPLUG_CPU
1458 	if (!setup_max_cpus)
1459 #endif
1460 	if (possible > i) {
1461 		pr_warn("%d Processors exceeds max_cpus limit of %u\n",
1462 			possible, setup_max_cpus);
1463 		possible = i;
1464 	}
1465 
1466 	set_nr_cpu_ids(possible);
1467 
1468 	pr_info("Allowing %d CPUs, %d hotplug CPUs\n",
1469 		possible, max_t(int, possible - num_processors, 0));
1470 
1471 	reset_cpu_possible_mask();
1472 
1473 	for (i = 0; i < possible; i++)
1474 		set_cpu_possible(i, true);
1475 }
1476 
1477 /* correctly size the local cpu masks */
1478 void __init setup_cpu_local_masks(void)
1479 {
1480 	alloc_bootmem_cpumask_var(&cpu_initialized_mask);
1481 	alloc_bootmem_cpumask_var(&cpu_callout_mask);
1482 	alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask);
1483 }
1484 
1485 #ifdef CONFIG_HOTPLUG_CPU
1486 
1487 /* Recompute SMT state for all CPUs on offline */
1488 static void recompute_smt_state(void)
1489 {
1490 	int max_threads, cpu;
1491 
1492 	max_threads = 0;
1493 	for_each_online_cpu (cpu) {
1494 		int threads = cpumask_weight(topology_sibling_cpumask(cpu));
1495 
1496 		if (threads > max_threads)
1497 			max_threads = threads;
1498 	}
1499 	__max_smt_threads = max_threads;
1500 }
1501 
1502 static void remove_siblinginfo(int cpu)
1503 {
1504 	int sibling;
1505 	struct cpuinfo_x86 *c = &cpu_data(cpu);
1506 
1507 	for_each_cpu(sibling, topology_core_cpumask(cpu)) {
1508 		cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
1509 		/*/
1510 		 * last thread sibling in this cpu core going down
1511 		 */
1512 		if (cpumask_weight(topology_sibling_cpumask(cpu)) == 1)
1513 			cpu_data(sibling).booted_cores--;
1514 	}
1515 
1516 	for_each_cpu(sibling, topology_die_cpumask(cpu))
1517 		cpumask_clear_cpu(cpu, topology_die_cpumask(sibling));
1518 
1519 	for_each_cpu(sibling, topology_sibling_cpumask(cpu)) {
1520 		cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling));
1521 		if (cpumask_weight(topology_sibling_cpumask(sibling)) == 1)
1522 			cpu_data(sibling).smt_active = false;
1523 	}
1524 
1525 	for_each_cpu(sibling, cpu_llc_shared_mask(cpu))
1526 		cpumask_clear_cpu(cpu, cpu_llc_shared_mask(sibling));
1527 	for_each_cpu(sibling, cpu_l2c_shared_mask(cpu))
1528 		cpumask_clear_cpu(cpu, cpu_l2c_shared_mask(sibling));
1529 	cpumask_clear(cpu_llc_shared_mask(cpu));
1530 	cpumask_clear(cpu_l2c_shared_mask(cpu));
1531 	cpumask_clear(topology_sibling_cpumask(cpu));
1532 	cpumask_clear(topology_core_cpumask(cpu));
1533 	cpumask_clear(topology_die_cpumask(cpu));
1534 	c->cpu_core_id = 0;
1535 	c->booted_cores = 0;
1536 	cpumask_clear_cpu(cpu, cpu_sibling_setup_mask);
1537 	recompute_smt_state();
1538 }
1539 
1540 static void remove_cpu_from_maps(int cpu)
1541 {
1542 	set_cpu_online(cpu, false);
1543 	cpumask_clear_cpu(cpu, cpu_callout_mask);
1544 	/* was set by cpu_init() */
1545 	cpumask_clear_cpu(cpu, cpu_initialized_mask);
1546 	numa_remove_cpu(cpu);
1547 }
1548 
1549 void cpu_disable_common(void)
1550 {
1551 	int cpu = smp_processor_id();
1552 
1553 	remove_siblinginfo(cpu);
1554 
1555 	/* It's now safe to remove this processor from the online map */
1556 	lock_vector_lock();
1557 	remove_cpu_from_maps(cpu);
1558 	unlock_vector_lock();
1559 	fixup_irqs();
1560 	lapic_offline();
1561 }
1562 
1563 int native_cpu_disable(void)
1564 {
1565 	int ret;
1566 
1567 	ret = lapic_can_unplug_cpu();
1568 	if (ret)
1569 		return ret;
1570 
1571 	cpu_disable_common();
1572 
1573         /*
1574          * Disable the local APIC. Otherwise IPI broadcasts will reach
1575          * it. It still responds normally to INIT, NMI, SMI, and SIPI
1576          * messages.
1577          *
1578          * Disabling the APIC must happen after cpu_disable_common()
1579          * which invokes fixup_irqs().
1580          *
1581          * Disabling the APIC preserves already set bits in IRR, but
1582          * an interrupt arriving after disabling the local APIC does not
1583          * set the corresponding IRR bit.
1584          *
1585          * fixup_irqs() scans IRR for set bits so it can raise a not
1586          * yet handled interrupt on the new destination CPU via an IPI
1587          * but obviously it can't do so for IRR bits which are not set.
1588          * IOW, interrupts arriving after disabling the local APIC will
1589          * be lost.
1590          */
1591 	apic_soft_disable();
1592 
1593 	return 0;
1594 }
1595 
1596 int common_cpu_die(unsigned int cpu)
1597 {
1598 	int ret = 0;
1599 
1600 	/* We don't do anything here: idle task is faking death itself. */
1601 
1602 	/* They ack this in play_dead() by setting CPU_DEAD */
1603 	if (cpu_wait_death(cpu, 5)) {
1604 		if (system_state == SYSTEM_RUNNING)
1605 			pr_info("CPU %u is now offline\n", cpu);
1606 	} else {
1607 		pr_err("CPU %u didn't die...\n", cpu);
1608 		ret = -1;
1609 	}
1610 
1611 	return ret;
1612 }
1613 
1614 void native_cpu_die(unsigned int cpu)
1615 {
1616 	common_cpu_die(cpu);
1617 }
1618 
1619 void play_dead_common(void)
1620 {
1621 	idle_task_exit();
1622 
1623 	/* Ack it */
1624 	(void)cpu_report_death();
1625 
1626 	/*
1627 	 * With physical CPU hotplug, we should halt the cpu
1628 	 */
1629 	local_irq_disable();
1630 }
1631 
1632 /*
1633  * We need to flush the caches before going to sleep, lest we have
1634  * dirty data in our caches when we come back up.
1635  */
1636 static inline void mwait_play_dead(void)
1637 {
1638 	unsigned int eax, ebx, ecx, edx;
1639 	unsigned int highest_cstate = 0;
1640 	unsigned int highest_subcstate = 0;
1641 	void *mwait_ptr;
1642 	int i;
1643 
1644 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
1645 	    boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
1646 		return;
1647 	if (!this_cpu_has(X86_FEATURE_MWAIT))
1648 		return;
1649 	if (!this_cpu_has(X86_FEATURE_CLFLUSH))
1650 		return;
1651 	if (__this_cpu_read(cpu_info.cpuid_level) < CPUID_MWAIT_LEAF)
1652 		return;
1653 
1654 	eax = CPUID_MWAIT_LEAF;
1655 	ecx = 0;
1656 	native_cpuid(&eax, &ebx, &ecx, &edx);
1657 
1658 	/*
1659 	 * eax will be 0 if EDX enumeration is not valid.
1660 	 * Initialized below to cstate, sub_cstate value when EDX is valid.
1661 	 */
1662 	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED)) {
1663 		eax = 0;
1664 	} else {
1665 		edx >>= MWAIT_SUBSTATE_SIZE;
1666 		for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) {
1667 			if (edx & MWAIT_SUBSTATE_MASK) {
1668 				highest_cstate = i;
1669 				highest_subcstate = edx & MWAIT_SUBSTATE_MASK;
1670 			}
1671 		}
1672 		eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) |
1673 			(highest_subcstate - 1);
1674 	}
1675 
1676 	/*
1677 	 * This should be a memory location in a cache line which is
1678 	 * unlikely to be touched by other processors.  The actual
1679 	 * content is immaterial as it is not actually modified in any way.
1680 	 */
1681 	mwait_ptr = &current_thread_info()->flags;
1682 
1683 	wbinvd();
1684 
1685 	while (1) {
1686 		/*
1687 		 * The CLFLUSH is a workaround for erratum AAI65 for
1688 		 * the Xeon 7400 series.  It's not clear it is actually
1689 		 * needed, but it should be harmless in either case.
1690 		 * The WBINVD is insufficient due to the spurious-wakeup
1691 		 * case where we return around the loop.
1692 		 */
1693 		mb();
1694 		clflush(mwait_ptr);
1695 		mb();
1696 		__monitor(mwait_ptr, 0, 0);
1697 		mb();
1698 		__mwait(eax, 0);
1699 	}
1700 }
1701 
1702 void __noreturn hlt_play_dead(void)
1703 {
1704 	if (__this_cpu_read(cpu_info.x86) >= 4)
1705 		wbinvd();
1706 
1707 	while (1)
1708 		native_halt();
1709 }
1710 
1711 void native_play_dead(void)
1712 {
1713 	play_dead_common();
1714 	tboot_shutdown(TB_SHUTDOWN_WFS);
1715 
1716 	mwait_play_dead();
1717 	if (cpuidle_play_dead())
1718 		hlt_play_dead();
1719 }
1720 
1721 #else /* ... !CONFIG_HOTPLUG_CPU */
1722 int native_cpu_disable(void)
1723 {
1724 	return -ENOSYS;
1725 }
1726 
1727 void native_cpu_die(unsigned int cpu)
1728 {
1729 	/* We said "no" in __cpu_disable */
1730 	BUG();
1731 }
1732 
1733 void native_play_dead(void)
1734 {
1735 	BUG();
1736 }
1737 
1738 #endif
1739