xref: /openbmc/linux/arch/x86/kernel/apic/apic.c (revision 1802d0be)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *	Local APIC handling, local APIC timers
4  *
5  *	(c) 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
6  *
7  *	Fixes
8  *	Maciej W. Rozycki	:	Bits for genuine 82489DX APICs;
9  *					thanks to Eric Gilmore
10  *					and Rolf G. Tews
11  *					for testing these extensively.
12  *	Maciej W. Rozycki	:	Various updates and fixes.
13  *	Mikael Pettersson	:	Power Management for UP-APIC.
14  *	Pavel Machek and
15  *	Mikael Pettersson	:	PM converted to driver model.
16  */
17 
18 #include <linux/perf_event.h>
19 #include <linux/kernel_stat.h>
20 #include <linux/mc146818rtc.h>
21 #include <linux/acpi_pmtmr.h>
22 #include <linux/clockchips.h>
23 #include <linux/interrupt.h>
24 #include <linux/memblock.h>
25 #include <linux/ftrace.h>
26 #include <linux/ioport.h>
27 #include <linux/export.h>
28 #include <linux/syscore_ops.h>
29 #include <linux/delay.h>
30 #include <linux/timex.h>
31 #include <linux/i8253.h>
32 #include <linux/dmar.h>
33 #include <linux/init.h>
34 #include <linux/cpu.h>
35 #include <linux/dmi.h>
36 #include <linux/smp.h>
37 #include <linux/mm.h>
38 
39 #include <asm/trace/irq_vectors.h>
40 #include <asm/irq_remapping.h>
41 #include <asm/perf_event.h>
42 #include <asm/x86_init.h>
43 #include <asm/pgalloc.h>
44 #include <linux/atomic.h>
45 #include <asm/mpspec.h>
46 #include <asm/i8259.h>
47 #include <asm/proto.h>
48 #include <asm/traps.h>
49 #include <asm/apic.h>
50 #include <asm/io_apic.h>
51 #include <asm/desc.h>
52 #include <asm/hpet.h>
53 #include <asm/mtrr.h>
54 #include <asm/time.h>
55 #include <asm/smp.h>
56 #include <asm/mce.h>
57 #include <asm/tsc.h>
58 #include <asm/hypervisor.h>
59 #include <asm/cpu_device_id.h>
60 #include <asm/intel-family.h>
61 #include <asm/irq_regs.h>
62 
63 unsigned int num_processors;
64 
65 unsigned disabled_cpus;
66 
67 /* Processor that is doing the boot up */
68 unsigned int boot_cpu_physical_apicid = -1U;
69 EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
70 
71 u8 boot_cpu_apic_version;
72 
73 /*
74  * The highest APIC ID seen during enumeration.
75  */
76 static unsigned int max_physical_apicid;
77 
78 /*
79  * Bitmask of physically existing CPUs:
80  */
81 physid_mask_t phys_cpu_present_map;
82 
83 /*
84  * Processor to be disabled specified by kernel parameter
85  * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
86  * avoid undefined behaviour caused by sending INIT from AP to BSP.
87  */
88 static unsigned int disabled_cpu_apicid __read_mostly = BAD_APICID;
89 
90 /*
91  * This variable controls which CPUs receive external NMIs.  By default,
92  * external NMIs are delivered only to the BSP.
93  */
94 static int apic_extnmi = APIC_EXTNMI_BSP;
95 
96 /*
97  * Map cpu index to physical APIC ID
98  */
99 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid, BAD_APICID);
100 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_bios_cpu_apicid, BAD_APICID);
101 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, U32_MAX);
102 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
103 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
104 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
105 
106 #ifdef CONFIG_X86_32
107 
108 /*
109  * On x86_32, the mapping between cpu and logical apicid may vary
110  * depending on apic in use.  The following early percpu variable is
111  * used for the mapping.  This is where the behaviors of x86_64 and 32
112  * actually diverge.  Let's keep it ugly for now.
113  */
114 DEFINE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid, BAD_APICID);
115 
116 /* Local APIC was disabled by the BIOS and enabled by the kernel */
117 static int enabled_via_apicbase;
118 
119 /*
120  * Handle interrupt mode configuration register (IMCR).
121  * This register controls whether the interrupt signals
122  * that reach the BSP come from the master PIC or from the
123  * local APIC. Before entering Symmetric I/O Mode, either
124  * the BIOS or the operating system must switch out of
125  * PIC Mode by changing the IMCR.
126  */
127 static inline void imcr_pic_to_apic(void)
128 {
129 	/* select IMCR register */
130 	outb(0x70, 0x22);
131 	/* NMI and 8259 INTR go through APIC */
132 	outb(0x01, 0x23);
133 }
134 
135 static inline void imcr_apic_to_pic(void)
136 {
137 	/* select IMCR register */
138 	outb(0x70, 0x22);
139 	/* NMI and 8259 INTR go directly to BSP */
140 	outb(0x00, 0x23);
141 }
142 #endif
143 
144 /*
145  * Knob to control our willingness to enable the local APIC.
146  *
147  * +1=force-enable
148  */
149 static int force_enable_local_apic __initdata;
150 
151 /*
152  * APIC command line parameters
153  */
154 static int __init parse_lapic(char *arg)
155 {
156 	if (IS_ENABLED(CONFIG_X86_32) && !arg)
157 		force_enable_local_apic = 1;
158 	else if (arg && !strncmp(arg, "notscdeadline", 13))
159 		setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
160 	return 0;
161 }
162 early_param("lapic", parse_lapic);
163 
164 #ifdef CONFIG_X86_64
165 static int apic_calibrate_pmtmr __initdata;
166 static __init int setup_apicpmtimer(char *s)
167 {
168 	apic_calibrate_pmtmr = 1;
169 	notsc_setup(NULL);
170 	return 0;
171 }
172 __setup("apicpmtimer", setup_apicpmtimer);
173 #endif
174 
175 unsigned long mp_lapic_addr;
176 int disable_apic;
177 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
178 static int disable_apic_timer __initdata;
179 /* Local APIC timer works in C2 */
180 int local_apic_timer_c2_ok;
181 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
182 
183 /*
184  * Debug level, exported for io_apic.c
185  */
186 unsigned int apic_verbosity;
187 
188 int pic_mode;
189 
190 /* Have we found an MP table */
191 int smp_found_config;
192 
193 static struct resource lapic_resource = {
194 	.name = "Local APIC",
195 	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
196 };
197 
198 unsigned int lapic_timer_frequency = 0;
199 
200 static void apic_pm_activate(void);
201 
202 static unsigned long apic_phys;
203 
204 /*
205  * Get the LAPIC version
206  */
207 static inline int lapic_get_version(void)
208 {
209 	return GET_APIC_VERSION(apic_read(APIC_LVR));
210 }
211 
212 /*
213  * Check, if the APIC is integrated or a separate chip
214  */
215 static inline int lapic_is_integrated(void)
216 {
217 	return APIC_INTEGRATED(lapic_get_version());
218 }
219 
220 /*
221  * Check, whether this is a modern or a first generation APIC
222  */
223 static int modern_apic(void)
224 {
225 	/* AMD systems use old APIC versions, so check the CPU */
226 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
227 	    boot_cpu_data.x86 >= 0xf)
228 		return 1;
229 
230 	/* Hygon systems use modern APIC */
231 	if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
232 		return 1;
233 
234 	return lapic_get_version() >= 0x14;
235 }
236 
237 /*
238  * right after this call apic become NOOP driven
239  * so apic->write/read doesn't do anything
240  */
241 static void __init apic_disable(void)
242 {
243 	pr_info("APIC: switched to apic NOOP\n");
244 	apic = &apic_noop;
245 }
246 
247 void native_apic_wait_icr_idle(void)
248 {
249 	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
250 		cpu_relax();
251 }
252 
253 u32 native_safe_apic_wait_icr_idle(void)
254 {
255 	u32 send_status;
256 	int timeout;
257 
258 	timeout = 0;
259 	do {
260 		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
261 		if (!send_status)
262 			break;
263 		inc_irq_stat(icr_read_retry_count);
264 		udelay(100);
265 	} while (timeout++ < 1000);
266 
267 	return send_status;
268 }
269 
270 void native_apic_icr_write(u32 low, u32 id)
271 {
272 	unsigned long flags;
273 
274 	local_irq_save(flags);
275 	apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
276 	apic_write(APIC_ICR, low);
277 	local_irq_restore(flags);
278 }
279 
280 u64 native_apic_icr_read(void)
281 {
282 	u32 icr1, icr2;
283 
284 	icr2 = apic_read(APIC_ICR2);
285 	icr1 = apic_read(APIC_ICR);
286 
287 	return icr1 | ((u64)icr2 << 32);
288 }
289 
290 #ifdef CONFIG_X86_32
291 /**
292  * get_physical_broadcast - Get number of physical broadcast IDs
293  */
294 int get_physical_broadcast(void)
295 {
296 	return modern_apic() ? 0xff : 0xf;
297 }
298 #endif
299 
300 /**
301  * lapic_get_maxlvt - get the maximum number of local vector table entries
302  */
303 int lapic_get_maxlvt(void)
304 {
305 	/*
306 	 * - we always have APIC integrated on 64bit mode
307 	 * - 82489DXs do not report # of LVT entries
308 	 */
309 	return lapic_is_integrated() ? GET_APIC_MAXLVT(apic_read(APIC_LVR)) : 2;
310 }
311 
312 /*
313  * Local APIC timer
314  */
315 
316 /* Clock divisor */
317 #define APIC_DIVISOR 16
318 #define TSC_DIVISOR  8
319 
320 /*
321  * This function sets up the local APIC timer, with a timeout of
322  * 'clocks' APIC bus clock. During calibration we actually call
323  * this function twice on the boot CPU, once with a bogus timeout
324  * value, second time for real. The other (noncalibrating) CPUs
325  * call this function only once, with the real, calibrated value.
326  *
327  * We do reads before writes even if unnecessary, to get around the
328  * P5 APIC double write bug.
329  */
330 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
331 {
332 	unsigned int lvtt_value, tmp_value;
333 
334 	lvtt_value = LOCAL_TIMER_VECTOR;
335 	if (!oneshot)
336 		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
337 	else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
338 		lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE;
339 
340 	if (!lapic_is_integrated())
341 		lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
342 
343 	if (!irqen)
344 		lvtt_value |= APIC_LVT_MASKED;
345 
346 	apic_write(APIC_LVTT, lvtt_value);
347 
348 	if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) {
349 		/*
350 		 * See Intel SDM: TSC-Deadline Mode chapter. In xAPIC mode,
351 		 * writing to the APIC LVTT and TSC_DEADLINE MSR isn't serialized.
352 		 * According to Intel, MFENCE can do the serialization here.
353 		 */
354 		asm volatile("mfence" : : : "memory");
355 
356 		printk_once(KERN_DEBUG "TSC deadline timer enabled\n");
357 		return;
358 	}
359 
360 	/*
361 	 * Divide PICLK by 16
362 	 */
363 	tmp_value = apic_read(APIC_TDCR);
364 	apic_write(APIC_TDCR,
365 		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
366 		APIC_TDR_DIV_16);
367 
368 	if (!oneshot)
369 		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
370 }
371 
372 /*
373  * Setup extended LVT, AMD specific
374  *
375  * Software should use the LVT offsets the BIOS provides.  The offsets
376  * are determined by the subsystems using it like those for MCE
377  * threshold or IBS.  On K8 only offset 0 (APIC500) and MCE interrupts
378  * are supported. Beginning with family 10h at least 4 offsets are
379  * available.
380  *
381  * Since the offsets must be consistent for all cores, we keep track
382  * of the LVT offsets in software and reserve the offset for the same
383  * vector also to be used on other cores. An offset is freed by
384  * setting the entry to APIC_EILVT_MASKED.
385  *
386  * If the BIOS is right, there should be no conflicts. Otherwise a
387  * "[Firmware Bug]: ..." error message is generated. However, if
388  * software does not properly determines the offsets, it is not
389  * necessarily a BIOS bug.
390  */
391 
392 static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
393 
394 static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
395 {
396 	return (old & APIC_EILVT_MASKED)
397 		|| (new == APIC_EILVT_MASKED)
398 		|| ((new & ~APIC_EILVT_MASKED) == old);
399 }
400 
401 static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
402 {
403 	unsigned int rsvd, vector;
404 
405 	if (offset >= APIC_EILVT_NR_MAX)
406 		return ~0;
407 
408 	rsvd = atomic_read(&eilvt_offsets[offset]);
409 	do {
410 		vector = rsvd & ~APIC_EILVT_MASKED;	/* 0: unassigned */
411 		if (vector && !eilvt_entry_is_changeable(vector, new))
412 			/* may not change if vectors are different */
413 			return rsvd;
414 		rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new);
415 	} while (rsvd != new);
416 
417 	rsvd &= ~APIC_EILVT_MASKED;
418 	if (rsvd && rsvd != vector)
419 		pr_info("LVT offset %d assigned for vector 0x%02x\n",
420 			offset, rsvd);
421 
422 	return new;
423 }
424 
425 /*
426  * If mask=1, the LVT entry does not generate interrupts while mask=0
427  * enables the vector. See also the BKDGs. Must be called with
428  * preemption disabled.
429  */
430 
431 int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
432 {
433 	unsigned long reg = APIC_EILVTn(offset);
434 	unsigned int new, old, reserved;
435 
436 	new = (mask << 16) | (msg_type << 8) | vector;
437 	old = apic_read(reg);
438 	reserved = reserve_eilvt_offset(offset, new);
439 
440 	if (reserved != new) {
441 		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
442 		       "vector 0x%x, but the register is already in use for "
443 		       "vector 0x%x on another cpu\n",
444 		       smp_processor_id(), reg, offset, new, reserved);
445 		return -EINVAL;
446 	}
447 
448 	if (!eilvt_entry_is_changeable(old, new)) {
449 		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
450 		       "vector 0x%x, but the register is already in use for "
451 		       "vector 0x%x on this cpu\n",
452 		       smp_processor_id(), reg, offset, new, old);
453 		return -EBUSY;
454 	}
455 
456 	apic_write(reg, new);
457 
458 	return 0;
459 }
460 EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
461 
462 /*
463  * Program the next event, relative to now
464  */
465 static int lapic_next_event(unsigned long delta,
466 			    struct clock_event_device *evt)
467 {
468 	apic_write(APIC_TMICT, delta);
469 	return 0;
470 }
471 
472 static int lapic_next_deadline(unsigned long delta,
473 			       struct clock_event_device *evt)
474 {
475 	u64 tsc;
476 
477 	tsc = rdtsc();
478 	wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR));
479 	return 0;
480 }
481 
482 static int lapic_timer_shutdown(struct clock_event_device *evt)
483 {
484 	unsigned int v;
485 
486 	/* Lapic used as dummy for broadcast ? */
487 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
488 		return 0;
489 
490 	v = apic_read(APIC_LVTT);
491 	v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
492 	apic_write(APIC_LVTT, v);
493 	apic_write(APIC_TMICT, 0);
494 	return 0;
495 }
496 
497 static inline int
498 lapic_timer_set_periodic_oneshot(struct clock_event_device *evt, bool oneshot)
499 {
500 	/* Lapic used as dummy for broadcast ? */
501 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
502 		return 0;
503 
504 	__setup_APIC_LVTT(lapic_timer_frequency, oneshot, 1);
505 	return 0;
506 }
507 
508 static int lapic_timer_set_periodic(struct clock_event_device *evt)
509 {
510 	return lapic_timer_set_periodic_oneshot(evt, false);
511 }
512 
513 static int lapic_timer_set_oneshot(struct clock_event_device *evt)
514 {
515 	return lapic_timer_set_periodic_oneshot(evt, true);
516 }
517 
518 /*
519  * Local APIC timer broadcast function
520  */
521 static void lapic_timer_broadcast(const struct cpumask *mask)
522 {
523 #ifdef CONFIG_SMP
524 	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
525 #endif
526 }
527 
528 
529 /*
530  * The local apic timer can be used for any function which is CPU local.
531  */
532 static struct clock_event_device lapic_clockevent = {
533 	.name				= "lapic",
534 	.features			= CLOCK_EVT_FEAT_PERIODIC |
535 					  CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP
536 					  | CLOCK_EVT_FEAT_DUMMY,
537 	.shift				= 32,
538 	.set_state_shutdown		= lapic_timer_shutdown,
539 	.set_state_periodic		= lapic_timer_set_periodic,
540 	.set_state_oneshot		= lapic_timer_set_oneshot,
541 	.set_state_oneshot_stopped	= lapic_timer_shutdown,
542 	.set_next_event			= lapic_next_event,
543 	.broadcast			= lapic_timer_broadcast,
544 	.rating				= 100,
545 	.irq				= -1,
546 };
547 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
548 
549 #define DEADLINE_MODEL_MATCH_FUNC(model, func)	\
550 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&func }
551 
552 #define DEADLINE_MODEL_MATCH_REV(model, rev)	\
553 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)rev }
554 
555 static u32 hsx_deadline_rev(void)
556 {
557 	switch (boot_cpu_data.x86_stepping) {
558 	case 0x02: return 0x3a; /* EP */
559 	case 0x04: return 0x0f; /* EX */
560 	}
561 
562 	return ~0U;
563 }
564 
565 static u32 bdx_deadline_rev(void)
566 {
567 	switch (boot_cpu_data.x86_stepping) {
568 	case 0x02: return 0x00000011;
569 	case 0x03: return 0x0700000e;
570 	case 0x04: return 0x0f00000c;
571 	case 0x05: return 0x0e000003;
572 	}
573 
574 	return ~0U;
575 }
576 
577 static u32 skx_deadline_rev(void)
578 {
579 	switch (boot_cpu_data.x86_stepping) {
580 	case 0x03: return 0x01000136;
581 	case 0x04: return 0x02000014;
582 	}
583 
584 	if (boot_cpu_data.x86_stepping > 4)
585 		return 0;
586 
587 	return ~0U;
588 }
589 
590 static const struct x86_cpu_id deadline_match[] = {
591 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_HASWELL_X,	hsx_deadline_rev),
592 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_X,	0x0b000020),
593 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_BROADWELL_XEON_D,	bdx_deadline_rev),
594 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_SKYLAKE_X,	skx_deadline_rev),
595 
596 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_CORE,	0x22),
597 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_ULT,	0x20),
598 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_GT3E,	0x17),
599 
600 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_CORE,	0x25),
601 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_GT3E,	0x17),
602 
603 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_MOBILE,	0xb2),
604 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_DESKTOP,	0xb2),
605 
606 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_MOBILE,	0x52),
607 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_DESKTOP,	0x52),
608 
609 	{},
610 };
611 
612 static void apic_check_deadline_errata(void)
613 {
614 	const struct x86_cpu_id *m;
615 	u32 rev;
616 
617 	if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER) ||
618 	    boot_cpu_has(X86_FEATURE_HYPERVISOR))
619 		return;
620 
621 	m = x86_match_cpu(deadline_match);
622 	if (!m)
623 		return;
624 
625 	/*
626 	 * Function pointers will have the MSB set due to address layout,
627 	 * immediate revisions will not.
628 	 */
629 	if ((long)m->driver_data < 0)
630 		rev = ((u32 (*)(void))(m->driver_data))();
631 	else
632 		rev = (u32)m->driver_data;
633 
634 	if (boot_cpu_data.microcode >= rev)
635 		return;
636 
637 	setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
638 	pr_err(FW_BUG "TSC_DEADLINE disabled due to Errata; "
639 	       "please update microcode to version: 0x%x (or later)\n", rev);
640 }
641 
642 /*
643  * Setup the local APIC timer for this CPU. Copy the initialized values
644  * of the boot CPU and register the clock event in the framework.
645  */
646 static void setup_APIC_timer(void)
647 {
648 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
649 
650 	if (this_cpu_has(X86_FEATURE_ARAT)) {
651 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
652 		/* Make LAPIC timer preferrable over percpu HPET */
653 		lapic_clockevent.rating = 150;
654 	}
655 
656 	memcpy(levt, &lapic_clockevent, sizeof(*levt));
657 	levt->cpumask = cpumask_of(smp_processor_id());
658 
659 	if (this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
660 		levt->name = "lapic-deadline";
661 		levt->features &= ~(CLOCK_EVT_FEAT_PERIODIC |
662 				    CLOCK_EVT_FEAT_DUMMY);
663 		levt->set_next_event = lapic_next_deadline;
664 		clockevents_config_and_register(levt,
665 						tsc_khz * (1000 / TSC_DIVISOR),
666 						0xF, ~0UL);
667 	} else
668 		clockevents_register_device(levt);
669 }
670 
671 /*
672  * Install the updated TSC frequency from recalibration at the TSC
673  * deadline clockevent devices.
674  */
675 static void __lapic_update_tsc_freq(void *info)
676 {
677 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
678 
679 	if (!this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
680 		return;
681 
682 	clockevents_update_freq(levt, tsc_khz * (1000 / TSC_DIVISOR));
683 }
684 
685 void lapic_update_tsc_freq(void)
686 {
687 	/*
688 	 * The clockevent device's ->mult and ->shift can both be
689 	 * changed. In order to avoid races, schedule the frequency
690 	 * update code on each CPU.
691 	 */
692 	on_each_cpu(__lapic_update_tsc_freq, NULL, 0);
693 }
694 
695 /*
696  * In this functions we calibrate APIC bus clocks to the external timer.
697  *
698  * We want to do the calibration only once since we want to have local timer
699  * irqs syncron. CPUs connected by the same APIC bus have the very same bus
700  * frequency.
701  *
702  * This was previously done by reading the PIT/HPET and waiting for a wrap
703  * around to find out, that a tick has elapsed. I have a box, where the PIT
704  * readout is broken, so it never gets out of the wait loop again. This was
705  * also reported by others.
706  *
707  * Monitoring the jiffies value is inaccurate and the clockevents
708  * infrastructure allows us to do a simple substitution of the interrupt
709  * handler.
710  *
711  * The calibration routine also uses the pm_timer when possible, as the PIT
712  * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
713  * back to normal later in the boot process).
714  */
715 
716 #define LAPIC_CAL_LOOPS		(HZ/10)
717 
718 static __initdata int lapic_cal_loops = -1;
719 static __initdata long lapic_cal_t1, lapic_cal_t2;
720 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
721 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
722 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
723 
724 /*
725  * Temporary interrupt handler.
726  */
727 static void __init lapic_cal_handler(struct clock_event_device *dev)
728 {
729 	unsigned long long tsc = 0;
730 	long tapic = apic_read(APIC_TMCCT);
731 	unsigned long pm = acpi_pm_read_early();
732 
733 	if (boot_cpu_has(X86_FEATURE_TSC))
734 		tsc = rdtsc();
735 
736 	switch (lapic_cal_loops++) {
737 	case 0:
738 		lapic_cal_t1 = tapic;
739 		lapic_cal_tsc1 = tsc;
740 		lapic_cal_pm1 = pm;
741 		lapic_cal_j1 = jiffies;
742 		break;
743 
744 	case LAPIC_CAL_LOOPS:
745 		lapic_cal_t2 = tapic;
746 		lapic_cal_tsc2 = tsc;
747 		if (pm < lapic_cal_pm1)
748 			pm += ACPI_PM_OVRRUN;
749 		lapic_cal_pm2 = pm;
750 		lapic_cal_j2 = jiffies;
751 		break;
752 	}
753 }
754 
755 static int __init
756 calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
757 {
758 	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
759 	const long pm_thresh = pm_100ms / 100;
760 	unsigned long mult;
761 	u64 res;
762 
763 #ifndef CONFIG_X86_PM_TIMER
764 	return -1;
765 #endif
766 
767 	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
768 
769 	/* Check, if the PM timer is available */
770 	if (!deltapm)
771 		return -1;
772 
773 	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
774 
775 	if (deltapm > (pm_100ms - pm_thresh) &&
776 	    deltapm < (pm_100ms + pm_thresh)) {
777 		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
778 		return 0;
779 	}
780 
781 	res = (((u64)deltapm) *  mult) >> 22;
782 	do_div(res, 1000000);
783 	pr_warning("APIC calibration not consistent "
784 		   "with PM-Timer: %ldms instead of 100ms\n",(long)res);
785 
786 	/* Correct the lapic counter value */
787 	res = (((u64)(*delta)) * pm_100ms);
788 	do_div(res, deltapm);
789 	pr_info("APIC delta adjusted to PM-Timer: "
790 		"%lu (%ld)\n", (unsigned long)res, *delta);
791 	*delta = (long)res;
792 
793 	/* Correct the tsc counter value */
794 	if (boot_cpu_has(X86_FEATURE_TSC)) {
795 		res = (((u64)(*deltatsc)) * pm_100ms);
796 		do_div(res, deltapm);
797 		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
798 					  "PM-Timer: %lu (%ld)\n",
799 					(unsigned long)res, *deltatsc);
800 		*deltatsc = (long)res;
801 	}
802 
803 	return 0;
804 }
805 
806 static int __init lapic_init_clockevent(void)
807 {
808 	if (!lapic_timer_frequency)
809 		return -1;
810 
811 	/* Calculate the scaled math multiplication factor */
812 	lapic_clockevent.mult = div_sc(lapic_timer_frequency/APIC_DIVISOR,
813 					TICK_NSEC, lapic_clockevent.shift);
814 	lapic_clockevent.max_delta_ns =
815 		clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
816 	lapic_clockevent.max_delta_ticks = 0x7FFFFFFF;
817 	lapic_clockevent.min_delta_ns =
818 		clockevent_delta2ns(0xF, &lapic_clockevent);
819 	lapic_clockevent.min_delta_ticks = 0xF;
820 
821 	return 0;
822 }
823 
824 static int __init calibrate_APIC_clock(void)
825 {
826 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
827 	void (*real_handler)(struct clock_event_device *dev);
828 	unsigned long deltaj;
829 	long delta, deltatsc;
830 	int pm_referenced = 0;
831 
832 	if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
833 		return 0;
834 
835 	/*
836 	 * Check if lapic timer has already been calibrated by platform
837 	 * specific routine, such as tsc calibration code. If so just fill
838 	 * in the clockevent structure and return.
839 	 */
840 	if (!lapic_init_clockevent()) {
841 		apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
842 			    lapic_timer_frequency);
843 		/*
844 		 * Direct calibration methods must have an always running
845 		 * local APIC timer, no need for broadcast timer.
846 		 */
847 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
848 		return 0;
849 	}
850 
851 	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
852 		    "calibrating APIC timer ...\n");
853 
854 	local_irq_disable();
855 
856 	/* Replace the global interrupt handler */
857 	real_handler = global_clock_event->event_handler;
858 	global_clock_event->event_handler = lapic_cal_handler;
859 
860 	/*
861 	 * Setup the APIC counter to maximum. There is no way the lapic
862 	 * can underflow in the 100ms detection time frame
863 	 */
864 	__setup_APIC_LVTT(0xffffffff, 0, 0);
865 
866 	/* Let the interrupts run */
867 	local_irq_enable();
868 
869 	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
870 		cpu_relax();
871 
872 	local_irq_disable();
873 
874 	/* Restore the real event handler */
875 	global_clock_event->event_handler = real_handler;
876 
877 	/* Build delta t1-t2 as apic timer counts down */
878 	delta = lapic_cal_t1 - lapic_cal_t2;
879 	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
880 
881 	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
882 
883 	/* we trust the PM based calibration if possible */
884 	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
885 					&delta, &deltatsc);
886 
887 	lapic_timer_frequency = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
888 	lapic_init_clockevent();
889 
890 	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
891 	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
892 	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
893 		    lapic_timer_frequency);
894 
895 	if (boot_cpu_has(X86_FEATURE_TSC)) {
896 		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
897 			    "%ld.%04ld MHz.\n",
898 			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
899 			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
900 	}
901 
902 	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
903 		    "%u.%04u MHz.\n",
904 		    lapic_timer_frequency / (1000000 / HZ),
905 		    lapic_timer_frequency % (1000000 / HZ));
906 
907 	/*
908 	 * Do a sanity check on the APIC calibration result
909 	 */
910 	if (lapic_timer_frequency < (1000000 / HZ)) {
911 		local_irq_enable();
912 		pr_warning("APIC frequency too slow, disabling apic timer\n");
913 		return -1;
914 	}
915 
916 	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
917 
918 	/*
919 	 * PM timer calibration failed or not turned on
920 	 * so lets try APIC timer based calibration
921 	 */
922 	if (!pm_referenced) {
923 		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
924 
925 		/*
926 		 * Setup the apic timer manually
927 		 */
928 		levt->event_handler = lapic_cal_handler;
929 		lapic_timer_set_periodic(levt);
930 		lapic_cal_loops = -1;
931 
932 		/* Let the interrupts run */
933 		local_irq_enable();
934 
935 		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
936 			cpu_relax();
937 
938 		/* Stop the lapic timer */
939 		local_irq_disable();
940 		lapic_timer_shutdown(levt);
941 
942 		/* Jiffies delta */
943 		deltaj = lapic_cal_j2 - lapic_cal_j1;
944 		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
945 
946 		/* Check, if the jiffies result is consistent */
947 		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
948 			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
949 		else
950 			levt->features |= CLOCK_EVT_FEAT_DUMMY;
951 	}
952 	local_irq_enable();
953 
954 	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
955 		pr_warning("APIC timer disabled due to verification failure\n");
956 		return -1;
957 	}
958 
959 	return 0;
960 }
961 
962 /*
963  * Setup the boot APIC
964  *
965  * Calibrate and verify the result.
966  */
967 void __init setup_boot_APIC_clock(void)
968 {
969 	/*
970 	 * The local apic timer can be disabled via the kernel
971 	 * commandline or from the CPU detection code. Register the lapic
972 	 * timer as a dummy clock event source on SMP systems, so the
973 	 * broadcast mechanism is used. On UP systems simply ignore it.
974 	 */
975 	if (disable_apic_timer) {
976 		pr_info("Disabling APIC timer\n");
977 		/* No broadcast on UP ! */
978 		if (num_possible_cpus() > 1) {
979 			lapic_clockevent.mult = 1;
980 			setup_APIC_timer();
981 		}
982 		return;
983 	}
984 
985 	if (calibrate_APIC_clock()) {
986 		/* No broadcast on UP ! */
987 		if (num_possible_cpus() > 1)
988 			setup_APIC_timer();
989 		return;
990 	}
991 
992 	/*
993 	 * If nmi_watchdog is set to IO_APIC, we need the
994 	 * PIT/HPET going.  Otherwise register lapic as a dummy
995 	 * device.
996 	 */
997 	lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
998 
999 	/* Setup the lapic or request the broadcast */
1000 	setup_APIC_timer();
1001 	amd_e400_c1e_apic_setup();
1002 }
1003 
1004 void setup_secondary_APIC_clock(void)
1005 {
1006 	setup_APIC_timer();
1007 	amd_e400_c1e_apic_setup();
1008 }
1009 
1010 /*
1011  * The guts of the apic timer interrupt
1012  */
1013 static void local_apic_timer_interrupt(void)
1014 {
1015 	struct clock_event_device *evt = this_cpu_ptr(&lapic_events);
1016 
1017 	/*
1018 	 * Normally we should not be here till LAPIC has been initialized but
1019 	 * in some cases like kdump, its possible that there is a pending LAPIC
1020 	 * timer interrupt from previous kernel's context and is delivered in
1021 	 * new kernel the moment interrupts are enabled.
1022 	 *
1023 	 * Interrupts are enabled early and LAPIC is setup much later, hence
1024 	 * its possible that when we get here evt->event_handler is NULL.
1025 	 * Check for event_handler being NULL and discard the interrupt as
1026 	 * spurious.
1027 	 */
1028 	if (!evt->event_handler) {
1029 		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n",
1030 			   smp_processor_id());
1031 		/* Switch it off */
1032 		lapic_timer_shutdown(evt);
1033 		return;
1034 	}
1035 
1036 	/*
1037 	 * the NMI deadlock-detector uses this.
1038 	 */
1039 	inc_irq_stat(apic_timer_irqs);
1040 
1041 	evt->event_handler(evt);
1042 }
1043 
1044 /*
1045  * Local APIC timer interrupt. This is the most natural way for doing
1046  * local interrupts, but local timer interrupts can be emulated by
1047  * broadcast interrupts too. [in case the hw doesn't support APIC timers]
1048  *
1049  * [ if a single-CPU system runs an SMP kernel then we call the local
1050  *   interrupt as well. Thus we cannot inline the local irq ... ]
1051  */
1052 __visible void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
1053 {
1054 	struct pt_regs *old_regs = set_irq_regs(regs);
1055 
1056 	/*
1057 	 * NOTE! We'd better ACK the irq immediately,
1058 	 * because timer handling can be slow.
1059 	 *
1060 	 * update_process_times() expects us to have done irq_enter().
1061 	 * Besides, if we don't timer interrupts ignore the global
1062 	 * interrupt lock, which is the WrongThing (tm) to do.
1063 	 */
1064 	entering_ack_irq();
1065 	trace_local_timer_entry(LOCAL_TIMER_VECTOR);
1066 	local_apic_timer_interrupt();
1067 	trace_local_timer_exit(LOCAL_TIMER_VECTOR);
1068 	exiting_irq();
1069 
1070 	set_irq_regs(old_regs);
1071 }
1072 
1073 int setup_profiling_timer(unsigned int multiplier)
1074 {
1075 	return -EINVAL;
1076 }
1077 
1078 /*
1079  * Local APIC start and shutdown
1080  */
1081 
1082 /**
1083  * clear_local_APIC - shutdown the local APIC
1084  *
1085  * This is called, when a CPU is disabled and before rebooting, so the state of
1086  * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
1087  * leftovers during boot.
1088  */
1089 void clear_local_APIC(void)
1090 {
1091 	int maxlvt;
1092 	u32 v;
1093 
1094 	/* APIC hasn't been mapped yet */
1095 	if (!x2apic_mode && !apic_phys)
1096 		return;
1097 
1098 	maxlvt = lapic_get_maxlvt();
1099 	/*
1100 	 * Masking an LVT entry can trigger a local APIC error
1101 	 * if the vector is zero. Mask LVTERR first to prevent this.
1102 	 */
1103 	if (maxlvt >= 3) {
1104 		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
1105 		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
1106 	}
1107 	/*
1108 	 * Careful: we have to set masks only first to deassert
1109 	 * any level-triggered sources.
1110 	 */
1111 	v = apic_read(APIC_LVTT);
1112 	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
1113 	v = apic_read(APIC_LVT0);
1114 	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
1115 	v = apic_read(APIC_LVT1);
1116 	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
1117 	if (maxlvt >= 4) {
1118 		v = apic_read(APIC_LVTPC);
1119 		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
1120 	}
1121 
1122 	/* lets not touch this if we didn't frob it */
1123 #ifdef CONFIG_X86_THERMAL_VECTOR
1124 	if (maxlvt >= 5) {
1125 		v = apic_read(APIC_LVTTHMR);
1126 		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
1127 	}
1128 #endif
1129 #ifdef CONFIG_X86_MCE_INTEL
1130 	if (maxlvt >= 6) {
1131 		v = apic_read(APIC_LVTCMCI);
1132 		if (!(v & APIC_LVT_MASKED))
1133 			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
1134 	}
1135 #endif
1136 
1137 	/*
1138 	 * Clean APIC state for other OSs:
1139 	 */
1140 	apic_write(APIC_LVTT, APIC_LVT_MASKED);
1141 	apic_write(APIC_LVT0, APIC_LVT_MASKED);
1142 	apic_write(APIC_LVT1, APIC_LVT_MASKED);
1143 	if (maxlvt >= 3)
1144 		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
1145 	if (maxlvt >= 4)
1146 		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
1147 
1148 	/* Integrated APIC (!82489DX) ? */
1149 	if (lapic_is_integrated()) {
1150 		if (maxlvt > 3)
1151 			/* Clear ESR due to Pentium errata 3AP and 11AP */
1152 			apic_write(APIC_ESR, 0);
1153 		apic_read(APIC_ESR);
1154 	}
1155 }
1156 
1157 /**
1158  * disable_local_APIC - clear and disable the local APIC
1159  */
1160 void disable_local_APIC(void)
1161 {
1162 	unsigned int value;
1163 
1164 	/* APIC hasn't been mapped yet */
1165 	if (!x2apic_mode && !apic_phys)
1166 		return;
1167 
1168 	clear_local_APIC();
1169 
1170 	/*
1171 	 * Disable APIC (implies clearing of registers
1172 	 * for 82489DX!).
1173 	 */
1174 	value = apic_read(APIC_SPIV);
1175 	value &= ~APIC_SPIV_APIC_ENABLED;
1176 	apic_write(APIC_SPIV, value);
1177 
1178 #ifdef CONFIG_X86_32
1179 	/*
1180 	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
1181 	 * restore the disabled state.
1182 	 */
1183 	if (enabled_via_apicbase) {
1184 		unsigned int l, h;
1185 
1186 		rdmsr(MSR_IA32_APICBASE, l, h);
1187 		l &= ~MSR_IA32_APICBASE_ENABLE;
1188 		wrmsr(MSR_IA32_APICBASE, l, h);
1189 	}
1190 #endif
1191 }
1192 
1193 /*
1194  * If Linux enabled the LAPIC against the BIOS default disable it down before
1195  * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
1196  * not power-off.  Additionally clear all LVT entries before disable_local_APIC
1197  * for the case where Linux didn't enable the LAPIC.
1198  */
1199 void lapic_shutdown(void)
1200 {
1201 	unsigned long flags;
1202 
1203 	if (!boot_cpu_has(X86_FEATURE_APIC) && !apic_from_smp_config())
1204 		return;
1205 
1206 	local_irq_save(flags);
1207 
1208 #ifdef CONFIG_X86_32
1209 	if (!enabled_via_apicbase)
1210 		clear_local_APIC();
1211 	else
1212 #endif
1213 		disable_local_APIC();
1214 
1215 
1216 	local_irq_restore(flags);
1217 }
1218 
1219 /**
1220  * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1221  */
1222 void __init sync_Arb_IDs(void)
1223 {
1224 	/*
1225 	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1226 	 * needed on AMD.
1227 	 */
1228 	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1229 		return;
1230 
1231 	/*
1232 	 * Wait for idle.
1233 	 */
1234 	apic_wait_icr_idle();
1235 
1236 	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1237 	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1238 			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1239 }
1240 
1241 enum apic_intr_mode_id apic_intr_mode;
1242 
1243 static int __init apic_intr_mode_select(void)
1244 {
1245 	/* Check kernel option */
1246 	if (disable_apic) {
1247 		pr_info("APIC disabled via kernel command line\n");
1248 		return APIC_PIC;
1249 	}
1250 
1251 	/* Check BIOS */
1252 #ifdef CONFIG_X86_64
1253 	/* On 64-bit, the APIC must be integrated, Check local APIC only */
1254 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1255 		disable_apic = 1;
1256 		pr_info("APIC disabled by BIOS\n");
1257 		return APIC_PIC;
1258 	}
1259 #else
1260 	/* On 32-bit, the APIC may be integrated APIC or 82489DX */
1261 
1262 	/* Neither 82489DX nor integrated APIC ? */
1263 	if (!boot_cpu_has(X86_FEATURE_APIC) && !smp_found_config) {
1264 		disable_apic = 1;
1265 		return APIC_PIC;
1266 	}
1267 
1268 	/* If the BIOS pretends there is an integrated APIC ? */
1269 	if (!boot_cpu_has(X86_FEATURE_APIC) &&
1270 		APIC_INTEGRATED(boot_cpu_apic_version)) {
1271 		disable_apic = 1;
1272 		pr_err(FW_BUG "Local APIC %d not detected, force emulation\n",
1273 				       boot_cpu_physical_apicid);
1274 		return APIC_PIC;
1275 	}
1276 #endif
1277 
1278 	/* Check MP table or ACPI MADT configuration */
1279 	if (!smp_found_config) {
1280 		disable_ioapic_support();
1281 		if (!acpi_lapic) {
1282 			pr_info("APIC: ACPI MADT or MP tables are not detected\n");
1283 			return APIC_VIRTUAL_WIRE_NO_CONFIG;
1284 		}
1285 		return APIC_VIRTUAL_WIRE;
1286 	}
1287 
1288 #ifdef CONFIG_SMP
1289 	/* If SMP should be disabled, then really disable it! */
1290 	if (!setup_max_cpus) {
1291 		pr_info("APIC: SMP mode deactivated\n");
1292 		return APIC_SYMMETRIC_IO_NO_ROUTING;
1293 	}
1294 
1295 	if (read_apic_id() != boot_cpu_physical_apicid) {
1296 		panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
1297 		     read_apic_id(), boot_cpu_physical_apicid);
1298 		/* Or can we switch back to PIC here? */
1299 	}
1300 #endif
1301 
1302 	return APIC_SYMMETRIC_IO;
1303 }
1304 
1305 /*
1306  * An initial setup of the virtual wire mode.
1307  */
1308 void __init init_bsp_APIC(void)
1309 {
1310 	unsigned int value;
1311 
1312 	/*
1313 	 * Don't do the setup now if we have a SMP BIOS as the
1314 	 * through-I/O-APIC virtual wire mode might be active.
1315 	 */
1316 	if (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC))
1317 		return;
1318 
1319 	/*
1320 	 * Do not trust the local APIC being empty at bootup.
1321 	 */
1322 	clear_local_APIC();
1323 
1324 	/*
1325 	 * Enable APIC.
1326 	 */
1327 	value = apic_read(APIC_SPIV);
1328 	value &= ~APIC_VECTOR_MASK;
1329 	value |= APIC_SPIV_APIC_ENABLED;
1330 
1331 #ifdef CONFIG_X86_32
1332 	/* This bit is reserved on P4/Xeon and should be cleared */
1333 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1334 	    (boot_cpu_data.x86 == 15))
1335 		value &= ~APIC_SPIV_FOCUS_DISABLED;
1336 	else
1337 #endif
1338 		value |= APIC_SPIV_FOCUS_DISABLED;
1339 	value |= SPURIOUS_APIC_VECTOR;
1340 	apic_write(APIC_SPIV, value);
1341 
1342 	/*
1343 	 * Set up the virtual wire mode.
1344 	 */
1345 	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1346 	value = APIC_DM_NMI;
1347 	if (!lapic_is_integrated())		/* 82489DX */
1348 		value |= APIC_LVT_LEVEL_TRIGGER;
1349 	if (apic_extnmi == APIC_EXTNMI_NONE)
1350 		value |= APIC_LVT_MASKED;
1351 	apic_write(APIC_LVT1, value);
1352 }
1353 
1354 /* Init the interrupt delivery mode for the BSP */
1355 void __init apic_intr_mode_init(void)
1356 {
1357 	bool upmode = IS_ENABLED(CONFIG_UP_LATE_INIT);
1358 
1359 	apic_intr_mode = apic_intr_mode_select();
1360 
1361 	switch (apic_intr_mode) {
1362 	case APIC_PIC:
1363 		pr_info("APIC: Keep in PIC mode(8259)\n");
1364 		return;
1365 	case APIC_VIRTUAL_WIRE:
1366 		pr_info("APIC: Switch to virtual wire mode setup\n");
1367 		default_setup_apic_routing();
1368 		break;
1369 	case APIC_VIRTUAL_WIRE_NO_CONFIG:
1370 		pr_info("APIC: Switch to virtual wire mode setup with no configuration\n");
1371 		upmode = true;
1372 		default_setup_apic_routing();
1373 		break;
1374 	case APIC_SYMMETRIC_IO:
1375 		pr_info("APIC: Switch to symmetric I/O mode setup\n");
1376 		default_setup_apic_routing();
1377 		break;
1378 	case APIC_SYMMETRIC_IO_NO_ROUTING:
1379 		pr_info("APIC: Switch to symmetric I/O mode setup in no SMP routine\n");
1380 		break;
1381 	}
1382 
1383 	apic_bsp_setup(upmode);
1384 }
1385 
1386 static void lapic_setup_esr(void)
1387 {
1388 	unsigned int oldvalue, value, maxlvt;
1389 
1390 	if (!lapic_is_integrated()) {
1391 		pr_info("No ESR for 82489DX.\n");
1392 		return;
1393 	}
1394 
1395 	if (apic->disable_esr) {
1396 		/*
1397 		 * Something untraceable is creating bad interrupts on
1398 		 * secondary quads ... for the moment, just leave the
1399 		 * ESR disabled - we can't do anything useful with the
1400 		 * errors anyway - mbligh
1401 		 */
1402 		pr_info("Leaving ESR disabled.\n");
1403 		return;
1404 	}
1405 
1406 	maxlvt = lapic_get_maxlvt();
1407 	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1408 		apic_write(APIC_ESR, 0);
1409 	oldvalue = apic_read(APIC_ESR);
1410 
1411 	/* enables sending errors */
1412 	value = ERROR_APIC_VECTOR;
1413 	apic_write(APIC_LVTERR, value);
1414 
1415 	/*
1416 	 * spec says clear errors after enabling vector.
1417 	 */
1418 	if (maxlvt > 3)
1419 		apic_write(APIC_ESR, 0);
1420 	value = apic_read(APIC_ESR);
1421 	if (value != oldvalue)
1422 		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1423 			"vector: 0x%08x  after: 0x%08x\n",
1424 			oldvalue, value);
1425 }
1426 
1427 static void apic_pending_intr_clear(void)
1428 {
1429 	long long max_loops = cpu_khz ? cpu_khz : 1000000;
1430 	unsigned long long tsc = 0, ntsc;
1431 	unsigned int queued;
1432 	unsigned long value;
1433 	int i, j, acked = 0;
1434 
1435 	if (boot_cpu_has(X86_FEATURE_TSC))
1436 		tsc = rdtsc();
1437 	/*
1438 	 * After a crash, we no longer service the interrupts and a pending
1439 	 * interrupt from previous kernel might still have ISR bit set.
1440 	 *
1441 	 * Most probably by now CPU has serviced that pending interrupt and
1442 	 * it might not have done the ack_APIC_irq() because it thought,
1443 	 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1444 	 * does not clear the ISR bit and cpu thinks it has already serivced
1445 	 * the interrupt. Hence a vector might get locked. It was noticed
1446 	 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1447 	 */
1448 	do {
1449 		queued = 0;
1450 		for (i = APIC_ISR_NR - 1; i >= 0; i--)
1451 			queued |= apic_read(APIC_IRR + i*0x10);
1452 
1453 		for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1454 			value = apic_read(APIC_ISR + i*0x10);
1455 			for_each_set_bit(j, &value, 32) {
1456 				ack_APIC_irq();
1457 				acked++;
1458 			}
1459 		}
1460 		if (acked > 256) {
1461 			pr_err("LAPIC pending interrupts after %d EOI\n", acked);
1462 			break;
1463 		}
1464 		if (queued) {
1465 			if (boot_cpu_has(X86_FEATURE_TSC) && cpu_khz) {
1466 				ntsc = rdtsc();
1467 				max_loops = (cpu_khz << 10) - (ntsc - tsc);
1468 			} else {
1469 				max_loops--;
1470 			}
1471 		}
1472 	} while (queued && max_loops > 0);
1473 	WARN_ON(max_loops <= 0);
1474 }
1475 
1476 /**
1477  * setup_local_APIC - setup the local APIC
1478  *
1479  * Used to setup local APIC while initializing BSP or bringing up APs.
1480  * Always called with preemption disabled.
1481  */
1482 static void setup_local_APIC(void)
1483 {
1484 	int cpu = smp_processor_id();
1485 	unsigned int value;
1486 #ifdef CONFIG_X86_32
1487 	int logical_apicid, ldr_apicid;
1488 #endif
1489 
1490 
1491 	if (disable_apic) {
1492 		disable_ioapic_support();
1493 		return;
1494 	}
1495 
1496 #ifdef CONFIG_X86_32
1497 	/* Pound the ESR really hard over the head with a big hammer - mbligh */
1498 	if (lapic_is_integrated() && apic->disable_esr) {
1499 		apic_write(APIC_ESR, 0);
1500 		apic_write(APIC_ESR, 0);
1501 		apic_write(APIC_ESR, 0);
1502 		apic_write(APIC_ESR, 0);
1503 	}
1504 #endif
1505 	perf_events_lapic_init();
1506 
1507 	/*
1508 	 * Double-check whether this APIC is really registered.
1509 	 * This is meaningless in clustered apic mode, so we skip it.
1510 	 */
1511 	BUG_ON(!apic->apic_id_registered());
1512 
1513 	/*
1514 	 * Intel recommends to set DFR, LDR and TPR before enabling
1515 	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
1516 	 * document number 292116).  So here it goes...
1517 	 */
1518 	apic->init_apic_ldr();
1519 
1520 #ifdef CONFIG_X86_32
1521 	/*
1522 	 * APIC LDR is initialized.  If logical_apicid mapping was
1523 	 * initialized during get_smp_config(), make sure it matches the
1524 	 * actual value.
1525 	 */
1526 	logical_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
1527 	ldr_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
1528 	WARN_ON(logical_apicid != BAD_APICID && logical_apicid != ldr_apicid);
1529 	/* always use the value from LDR */
1530 	early_per_cpu(x86_cpu_to_logical_apicid, cpu) = ldr_apicid;
1531 #endif
1532 
1533 	/*
1534 	 * Set Task Priority to 'accept all'. We never change this
1535 	 * later on.
1536 	 */
1537 	value = apic_read(APIC_TASKPRI);
1538 	value &= ~APIC_TPRI_MASK;
1539 	apic_write(APIC_TASKPRI, value);
1540 
1541 	apic_pending_intr_clear();
1542 
1543 	/*
1544 	 * Now that we are all set up, enable the APIC
1545 	 */
1546 	value = apic_read(APIC_SPIV);
1547 	value &= ~APIC_VECTOR_MASK;
1548 	/*
1549 	 * Enable APIC
1550 	 */
1551 	value |= APIC_SPIV_APIC_ENABLED;
1552 
1553 #ifdef CONFIG_X86_32
1554 	/*
1555 	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1556 	 * certain networking cards. If high frequency interrupts are
1557 	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1558 	 * entry is masked/unmasked at a high rate as well then sooner or
1559 	 * later IOAPIC line gets 'stuck', no more interrupts are received
1560 	 * from the device. If focus CPU is disabled then the hang goes
1561 	 * away, oh well :-(
1562 	 *
1563 	 * [ This bug can be reproduced easily with a level-triggered
1564 	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1565 	 *   BX chipset. ]
1566 	 */
1567 	/*
1568 	 * Actually disabling the focus CPU check just makes the hang less
1569 	 * frequent as it makes the interrupt distributon model be more
1570 	 * like LRU than MRU (the short-term load is more even across CPUs).
1571 	 */
1572 
1573 	/*
1574 	 * - enable focus processor (bit==0)
1575 	 * - 64bit mode always use processor focus
1576 	 *   so no need to set it
1577 	 */
1578 	value &= ~APIC_SPIV_FOCUS_DISABLED;
1579 #endif
1580 
1581 	/*
1582 	 * Set spurious IRQ vector
1583 	 */
1584 	value |= SPURIOUS_APIC_VECTOR;
1585 	apic_write(APIC_SPIV, value);
1586 
1587 	/*
1588 	 * Set up LVT0, LVT1:
1589 	 *
1590 	 * set up through-local-APIC on the boot CPU's LINT0. This is not
1591 	 * strictly necessary in pure symmetric-IO mode, but sometimes
1592 	 * we delegate interrupts to the 8259A.
1593 	 */
1594 	/*
1595 	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1596 	 */
1597 	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1598 	if (!cpu && (pic_mode || !value || skip_ioapic_setup)) {
1599 		value = APIC_DM_EXTINT;
1600 		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
1601 	} else {
1602 		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1603 		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
1604 	}
1605 	apic_write(APIC_LVT0, value);
1606 
1607 	/*
1608 	 * Only the BSP sees the LINT1 NMI signal by default. This can be
1609 	 * modified by apic_extnmi= boot option.
1610 	 */
1611 	if ((!cpu && apic_extnmi != APIC_EXTNMI_NONE) ||
1612 	    apic_extnmi == APIC_EXTNMI_ALL)
1613 		value = APIC_DM_NMI;
1614 	else
1615 		value = APIC_DM_NMI | APIC_LVT_MASKED;
1616 
1617 	/* Is 82489DX ? */
1618 	if (!lapic_is_integrated())
1619 		value |= APIC_LVT_LEVEL_TRIGGER;
1620 	apic_write(APIC_LVT1, value);
1621 
1622 #ifdef CONFIG_X86_MCE_INTEL
1623 	/* Recheck CMCI information after local APIC is up on CPU #0 */
1624 	if (!cpu)
1625 		cmci_recheck();
1626 #endif
1627 }
1628 
1629 static void end_local_APIC_setup(void)
1630 {
1631 	lapic_setup_esr();
1632 
1633 #ifdef CONFIG_X86_32
1634 	{
1635 		unsigned int value;
1636 		/* Disable the local apic timer */
1637 		value = apic_read(APIC_LVTT);
1638 		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1639 		apic_write(APIC_LVTT, value);
1640 	}
1641 #endif
1642 
1643 	apic_pm_activate();
1644 }
1645 
1646 /*
1647  * APIC setup function for application processors. Called from smpboot.c
1648  */
1649 void apic_ap_setup(void)
1650 {
1651 	setup_local_APIC();
1652 	end_local_APIC_setup();
1653 }
1654 
1655 #ifdef CONFIG_X86_X2APIC
1656 int x2apic_mode;
1657 
1658 enum {
1659 	X2APIC_OFF,
1660 	X2APIC_ON,
1661 	X2APIC_DISABLED,
1662 };
1663 static int x2apic_state;
1664 
1665 static void __x2apic_disable(void)
1666 {
1667 	u64 msr;
1668 
1669 	if (!boot_cpu_has(X86_FEATURE_APIC))
1670 		return;
1671 
1672 	rdmsrl(MSR_IA32_APICBASE, msr);
1673 	if (!(msr & X2APIC_ENABLE))
1674 		return;
1675 	/* Disable xapic and x2apic first and then reenable xapic mode */
1676 	wrmsrl(MSR_IA32_APICBASE, msr & ~(X2APIC_ENABLE | XAPIC_ENABLE));
1677 	wrmsrl(MSR_IA32_APICBASE, msr & ~X2APIC_ENABLE);
1678 	printk_once(KERN_INFO "x2apic disabled\n");
1679 }
1680 
1681 static void __x2apic_enable(void)
1682 {
1683 	u64 msr;
1684 
1685 	rdmsrl(MSR_IA32_APICBASE, msr);
1686 	if (msr & X2APIC_ENABLE)
1687 		return;
1688 	wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE);
1689 	printk_once(KERN_INFO "x2apic enabled\n");
1690 }
1691 
1692 static int __init setup_nox2apic(char *str)
1693 {
1694 	if (x2apic_enabled()) {
1695 		int apicid = native_apic_msr_read(APIC_ID);
1696 
1697 		if (apicid >= 255) {
1698 			pr_warning("Apicid: %08x, cannot enforce nox2apic\n",
1699 				   apicid);
1700 			return 0;
1701 		}
1702 		pr_warning("x2apic already enabled.\n");
1703 		__x2apic_disable();
1704 	}
1705 	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
1706 	x2apic_state = X2APIC_DISABLED;
1707 	x2apic_mode = 0;
1708 	return 0;
1709 }
1710 early_param("nox2apic", setup_nox2apic);
1711 
1712 /* Called from cpu_init() to enable x2apic on (secondary) cpus */
1713 void x2apic_setup(void)
1714 {
1715 	/*
1716 	 * If x2apic is not in ON state, disable it if already enabled
1717 	 * from BIOS.
1718 	 */
1719 	if (x2apic_state != X2APIC_ON) {
1720 		__x2apic_disable();
1721 		return;
1722 	}
1723 	__x2apic_enable();
1724 }
1725 
1726 static __init void x2apic_disable(void)
1727 {
1728 	u32 x2apic_id, state = x2apic_state;
1729 
1730 	x2apic_mode = 0;
1731 	x2apic_state = X2APIC_DISABLED;
1732 
1733 	if (state != X2APIC_ON)
1734 		return;
1735 
1736 	x2apic_id = read_apic_id();
1737 	if (x2apic_id >= 255)
1738 		panic("Cannot disable x2apic, id: %08x\n", x2apic_id);
1739 
1740 	__x2apic_disable();
1741 	register_lapic_address(mp_lapic_addr);
1742 }
1743 
1744 static __init void x2apic_enable(void)
1745 {
1746 	if (x2apic_state != X2APIC_OFF)
1747 		return;
1748 
1749 	x2apic_mode = 1;
1750 	x2apic_state = X2APIC_ON;
1751 	__x2apic_enable();
1752 }
1753 
1754 static __init void try_to_enable_x2apic(int remap_mode)
1755 {
1756 	if (x2apic_state == X2APIC_DISABLED)
1757 		return;
1758 
1759 	if (remap_mode != IRQ_REMAP_X2APIC_MODE) {
1760 		/* IR is required if there is APIC ID > 255 even when running
1761 		 * under KVM
1762 		 */
1763 		if (max_physical_apicid > 255 ||
1764 		    !x86_init.hyper.x2apic_available()) {
1765 			pr_info("x2apic: IRQ remapping doesn't support X2APIC mode\n");
1766 			x2apic_disable();
1767 			return;
1768 		}
1769 
1770 		/*
1771 		 * without IR all CPUs can be addressed by IOAPIC/MSI
1772 		 * only in physical mode
1773 		 */
1774 		x2apic_phys = 1;
1775 	}
1776 	x2apic_enable();
1777 }
1778 
1779 void __init check_x2apic(void)
1780 {
1781 	if (x2apic_enabled()) {
1782 		pr_info("x2apic: enabled by BIOS, switching to x2apic ops\n");
1783 		x2apic_mode = 1;
1784 		x2apic_state = X2APIC_ON;
1785 	} else if (!boot_cpu_has(X86_FEATURE_X2APIC)) {
1786 		x2apic_state = X2APIC_DISABLED;
1787 	}
1788 }
1789 #else /* CONFIG_X86_X2APIC */
1790 static int __init validate_x2apic(void)
1791 {
1792 	if (!apic_is_x2apic_enabled())
1793 		return 0;
1794 	/*
1795 	 * Checkme: Can we simply turn off x2apic here instead of panic?
1796 	 */
1797 	panic("BIOS has enabled x2apic but kernel doesn't support x2apic, please disable x2apic in BIOS.\n");
1798 }
1799 early_initcall(validate_x2apic);
1800 
1801 static inline void try_to_enable_x2apic(int remap_mode) { }
1802 static inline void __x2apic_enable(void) { }
1803 #endif /* !CONFIG_X86_X2APIC */
1804 
1805 void __init enable_IR_x2apic(void)
1806 {
1807 	unsigned long flags;
1808 	int ret, ir_stat;
1809 
1810 	if (skip_ioapic_setup) {
1811 		pr_info("Not enabling interrupt remapping due to skipped IO-APIC setup\n");
1812 		return;
1813 	}
1814 
1815 	ir_stat = irq_remapping_prepare();
1816 	if (ir_stat < 0 && !x2apic_supported())
1817 		return;
1818 
1819 	ret = save_ioapic_entries();
1820 	if (ret) {
1821 		pr_info("Saving IO-APIC state failed: %d\n", ret);
1822 		return;
1823 	}
1824 
1825 	local_irq_save(flags);
1826 	legacy_pic->mask_all();
1827 	mask_ioapic_entries();
1828 
1829 	/* If irq_remapping_prepare() succeeded, try to enable it */
1830 	if (ir_stat >= 0)
1831 		ir_stat = irq_remapping_enable();
1832 	/* ir_stat contains the remap mode or an error code */
1833 	try_to_enable_x2apic(ir_stat);
1834 
1835 	if (ir_stat < 0)
1836 		restore_ioapic_entries();
1837 	legacy_pic->restore_mask();
1838 	local_irq_restore(flags);
1839 }
1840 
1841 #ifdef CONFIG_X86_64
1842 /*
1843  * Detect and enable local APICs on non-SMP boards.
1844  * Original code written by Keir Fraser.
1845  * On AMD64 we trust the BIOS - if it says no APIC it is likely
1846  * not correctly set up (usually the APIC timer won't work etc.)
1847  */
1848 static int __init detect_init_APIC(void)
1849 {
1850 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1851 		pr_info("No local APIC present\n");
1852 		return -1;
1853 	}
1854 
1855 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1856 	return 0;
1857 }
1858 #else
1859 
1860 static int __init apic_verify(void)
1861 {
1862 	u32 features, h, l;
1863 
1864 	/*
1865 	 * The APIC feature bit should now be enabled
1866 	 * in `cpuid'
1867 	 */
1868 	features = cpuid_edx(1);
1869 	if (!(features & (1 << X86_FEATURE_APIC))) {
1870 		pr_warning("Could not enable APIC!\n");
1871 		return -1;
1872 	}
1873 	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1874 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1875 
1876 	/* The BIOS may have set up the APIC at some other address */
1877 	if (boot_cpu_data.x86 >= 6) {
1878 		rdmsr(MSR_IA32_APICBASE, l, h);
1879 		if (l & MSR_IA32_APICBASE_ENABLE)
1880 			mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1881 	}
1882 
1883 	pr_info("Found and enabled local APIC!\n");
1884 	return 0;
1885 }
1886 
1887 int __init apic_force_enable(unsigned long addr)
1888 {
1889 	u32 h, l;
1890 
1891 	if (disable_apic)
1892 		return -1;
1893 
1894 	/*
1895 	 * Some BIOSes disable the local APIC in the APIC_BASE
1896 	 * MSR. This can only be done in software for Intel P6 or later
1897 	 * and AMD K7 (Model > 1) or later.
1898 	 */
1899 	if (boot_cpu_data.x86 >= 6) {
1900 		rdmsr(MSR_IA32_APICBASE, l, h);
1901 		if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1902 			pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1903 			l &= ~MSR_IA32_APICBASE_BASE;
1904 			l |= MSR_IA32_APICBASE_ENABLE | addr;
1905 			wrmsr(MSR_IA32_APICBASE, l, h);
1906 			enabled_via_apicbase = 1;
1907 		}
1908 	}
1909 	return apic_verify();
1910 }
1911 
1912 /*
1913  * Detect and initialize APIC
1914  */
1915 static int __init detect_init_APIC(void)
1916 {
1917 	/* Disabled by kernel option? */
1918 	if (disable_apic)
1919 		return -1;
1920 
1921 	switch (boot_cpu_data.x86_vendor) {
1922 	case X86_VENDOR_AMD:
1923 		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1924 		    (boot_cpu_data.x86 >= 15))
1925 			break;
1926 		goto no_apic;
1927 	case X86_VENDOR_HYGON:
1928 		break;
1929 	case X86_VENDOR_INTEL:
1930 		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1931 		    (boot_cpu_data.x86 == 5 && boot_cpu_has(X86_FEATURE_APIC)))
1932 			break;
1933 		goto no_apic;
1934 	default:
1935 		goto no_apic;
1936 	}
1937 
1938 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1939 		/*
1940 		 * Over-ride BIOS and try to enable the local APIC only if
1941 		 * "lapic" specified.
1942 		 */
1943 		if (!force_enable_local_apic) {
1944 			pr_info("Local APIC disabled by BIOS -- "
1945 				"you can enable it with \"lapic\"\n");
1946 			return -1;
1947 		}
1948 		if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
1949 			return -1;
1950 	} else {
1951 		if (apic_verify())
1952 			return -1;
1953 	}
1954 
1955 	apic_pm_activate();
1956 
1957 	return 0;
1958 
1959 no_apic:
1960 	pr_info("No local APIC present or hardware disabled\n");
1961 	return -1;
1962 }
1963 #endif
1964 
1965 /**
1966  * init_apic_mappings - initialize APIC mappings
1967  */
1968 void __init init_apic_mappings(void)
1969 {
1970 	unsigned int new_apicid;
1971 
1972 	apic_check_deadline_errata();
1973 
1974 	if (x2apic_mode) {
1975 		boot_cpu_physical_apicid = read_apic_id();
1976 		return;
1977 	}
1978 
1979 	/* If no local APIC can be found return early */
1980 	if (!smp_found_config && detect_init_APIC()) {
1981 		/* lets NOP'ify apic operations */
1982 		pr_info("APIC: disable apic facility\n");
1983 		apic_disable();
1984 	} else {
1985 		apic_phys = mp_lapic_addr;
1986 
1987 		/*
1988 		 * If the system has ACPI MADT tables or MP info, the LAPIC
1989 		 * address is already registered.
1990 		 */
1991 		if (!acpi_lapic && !smp_found_config)
1992 			register_lapic_address(apic_phys);
1993 	}
1994 
1995 	/*
1996 	 * Fetch the APIC ID of the BSP in case we have a
1997 	 * default configuration (or the MP table is broken).
1998 	 */
1999 	new_apicid = read_apic_id();
2000 	if (boot_cpu_physical_apicid != new_apicid) {
2001 		boot_cpu_physical_apicid = new_apicid;
2002 		/*
2003 		 * yeah -- we lie about apic_version
2004 		 * in case if apic was disabled via boot option
2005 		 * but it's not a problem for SMP compiled kernel
2006 		 * since apic_intr_mode_select is prepared for such
2007 		 * a case and disable smp mode
2008 		 */
2009 		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
2010 	}
2011 }
2012 
2013 void __init register_lapic_address(unsigned long address)
2014 {
2015 	mp_lapic_addr = address;
2016 
2017 	if (!x2apic_mode) {
2018 		set_fixmap_nocache(FIX_APIC_BASE, address);
2019 		apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
2020 			    APIC_BASE, address);
2021 	}
2022 	if (boot_cpu_physical_apicid == -1U) {
2023 		boot_cpu_physical_apicid  = read_apic_id();
2024 		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
2025 	}
2026 }
2027 
2028 /*
2029  * Local APIC interrupts
2030  */
2031 
2032 /*
2033  * This interrupt should _never_ happen with our APIC/SMP architecture
2034  */
2035 __visible void __irq_entry smp_spurious_interrupt(struct pt_regs *regs)
2036 {
2037 	u8 vector = ~regs->orig_ax;
2038 	u32 v;
2039 
2040 	entering_irq();
2041 	trace_spurious_apic_entry(vector);
2042 
2043 	/*
2044 	 * Check if this really is a spurious interrupt and ACK it
2045 	 * if it is a vectored one.  Just in case...
2046 	 * Spurious interrupts should not be ACKed.
2047 	 */
2048 	v = apic_read(APIC_ISR + ((vector & ~0x1f) >> 1));
2049 	if (v & (1 << (vector & 0x1f)))
2050 		ack_APIC_irq();
2051 
2052 	inc_irq_stat(irq_spurious_count);
2053 
2054 	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
2055 	pr_info("spurious APIC interrupt through vector %02x on CPU#%d, "
2056 		"should never happen.\n", vector, smp_processor_id());
2057 
2058 	trace_spurious_apic_exit(vector);
2059 	exiting_irq();
2060 }
2061 
2062 /*
2063  * This interrupt should never happen with our APIC/SMP architecture
2064  */
2065 __visible void __irq_entry smp_error_interrupt(struct pt_regs *regs)
2066 {
2067 	static const char * const error_interrupt_reason[] = {
2068 		"Send CS error",		/* APIC Error Bit 0 */
2069 		"Receive CS error",		/* APIC Error Bit 1 */
2070 		"Send accept error",		/* APIC Error Bit 2 */
2071 		"Receive accept error",		/* APIC Error Bit 3 */
2072 		"Redirectable IPI",		/* APIC Error Bit 4 */
2073 		"Send illegal vector",		/* APIC Error Bit 5 */
2074 		"Received illegal vector",	/* APIC Error Bit 6 */
2075 		"Illegal register address",	/* APIC Error Bit 7 */
2076 	};
2077 	u32 v, i = 0;
2078 
2079 	entering_irq();
2080 	trace_error_apic_entry(ERROR_APIC_VECTOR);
2081 
2082 	/* First tickle the hardware, only then report what went on. -- REW */
2083 	if (lapic_get_maxlvt() > 3)	/* Due to the Pentium erratum 3AP. */
2084 		apic_write(APIC_ESR, 0);
2085 	v = apic_read(APIC_ESR);
2086 	ack_APIC_irq();
2087 	atomic_inc(&irq_err_count);
2088 
2089 	apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x",
2090 		    smp_processor_id(), v);
2091 
2092 	v &= 0xff;
2093 	while (v) {
2094 		if (v & 0x1)
2095 			apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
2096 		i++;
2097 		v >>= 1;
2098 	}
2099 
2100 	apic_printk(APIC_DEBUG, KERN_CONT "\n");
2101 
2102 	trace_error_apic_exit(ERROR_APIC_VECTOR);
2103 	exiting_irq();
2104 }
2105 
2106 /**
2107  * connect_bsp_APIC - attach the APIC to the interrupt system
2108  */
2109 static void __init connect_bsp_APIC(void)
2110 {
2111 #ifdef CONFIG_X86_32
2112 	if (pic_mode) {
2113 		/*
2114 		 * Do not trust the local APIC being empty at bootup.
2115 		 */
2116 		clear_local_APIC();
2117 		/*
2118 		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
2119 		 * local APIC to INT and NMI lines.
2120 		 */
2121 		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
2122 				"enabling APIC mode.\n");
2123 		imcr_pic_to_apic();
2124 	}
2125 #endif
2126 }
2127 
2128 /**
2129  * disconnect_bsp_APIC - detach the APIC from the interrupt system
2130  * @virt_wire_setup:	indicates, whether virtual wire mode is selected
2131  *
2132  * Virtual wire mode is necessary to deliver legacy interrupts even when the
2133  * APIC is disabled.
2134  */
2135 void disconnect_bsp_APIC(int virt_wire_setup)
2136 {
2137 	unsigned int value;
2138 
2139 #ifdef CONFIG_X86_32
2140 	if (pic_mode) {
2141 		/*
2142 		 * Put the board back into PIC mode (has an effect only on
2143 		 * certain older boards).  Note that APIC interrupts, including
2144 		 * IPIs, won't work beyond this point!  The only exception are
2145 		 * INIT IPIs.
2146 		 */
2147 		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
2148 				"entering PIC mode.\n");
2149 		imcr_apic_to_pic();
2150 		return;
2151 	}
2152 #endif
2153 
2154 	/* Go back to Virtual Wire compatibility mode */
2155 
2156 	/* For the spurious interrupt use vector F, and enable it */
2157 	value = apic_read(APIC_SPIV);
2158 	value &= ~APIC_VECTOR_MASK;
2159 	value |= APIC_SPIV_APIC_ENABLED;
2160 	value |= 0xf;
2161 	apic_write(APIC_SPIV, value);
2162 
2163 	if (!virt_wire_setup) {
2164 		/*
2165 		 * For LVT0 make it edge triggered, active high,
2166 		 * external and enabled
2167 		 */
2168 		value = apic_read(APIC_LVT0);
2169 		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2170 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2171 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2172 		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2173 		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
2174 		apic_write(APIC_LVT0, value);
2175 	} else {
2176 		/* Disable LVT0 */
2177 		apic_write(APIC_LVT0, APIC_LVT_MASKED);
2178 	}
2179 
2180 	/*
2181 	 * For LVT1 make it edge triggered, active high,
2182 	 * nmi and enabled
2183 	 */
2184 	value = apic_read(APIC_LVT1);
2185 	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2186 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2187 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2188 	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2189 	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
2190 	apic_write(APIC_LVT1, value);
2191 }
2192 
2193 /*
2194  * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
2195  * contiguously, it equals to current allocated max logical CPU ID plus 1.
2196  * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
2197  * so the maximum of nr_logical_cpuids is nr_cpu_ids.
2198  *
2199  * NOTE: Reserve 0 for BSP.
2200  */
2201 static int nr_logical_cpuids = 1;
2202 
2203 /*
2204  * Used to store mapping between logical CPU IDs and APIC IDs.
2205  */
2206 static int cpuid_to_apicid[] = {
2207 	[0 ... NR_CPUS - 1] = -1,
2208 };
2209 
2210 #ifdef CONFIG_SMP
2211 /**
2212  * apic_id_is_primary_thread - Check whether APIC ID belongs to a primary thread
2213  * @id:	APIC ID to check
2214  */
2215 bool apic_id_is_primary_thread(unsigned int apicid)
2216 {
2217 	u32 mask;
2218 
2219 	if (smp_num_siblings == 1)
2220 		return true;
2221 	/* Isolate the SMT bit(s) in the APICID and check for 0 */
2222 	mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
2223 	return !(apicid & mask);
2224 }
2225 #endif
2226 
2227 /*
2228  * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
2229  * and cpuid_to_apicid[] synchronized.
2230  */
2231 static int allocate_logical_cpuid(int apicid)
2232 {
2233 	int i;
2234 
2235 	/*
2236 	 * cpuid <-> apicid mapping is persistent, so when a cpu is up,
2237 	 * check if the kernel has allocated a cpuid for it.
2238 	 */
2239 	for (i = 0; i < nr_logical_cpuids; i++) {
2240 		if (cpuid_to_apicid[i] == apicid)
2241 			return i;
2242 	}
2243 
2244 	/* Allocate a new cpuid. */
2245 	if (nr_logical_cpuids >= nr_cpu_ids) {
2246 		WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
2247 			     "Processor %d/0x%x and the rest are ignored.\n",
2248 			     nr_cpu_ids, nr_logical_cpuids, apicid);
2249 		return -EINVAL;
2250 	}
2251 
2252 	cpuid_to_apicid[nr_logical_cpuids] = apicid;
2253 	return nr_logical_cpuids++;
2254 }
2255 
2256 int generic_processor_info(int apicid, int version)
2257 {
2258 	int cpu, max = nr_cpu_ids;
2259 	bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
2260 				phys_cpu_present_map);
2261 
2262 	/*
2263 	 * boot_cpu_physical_apicid is designed to have the apicid
2264 	 * returned by read_apic_id(), i.e, the apicid of the
2265 	 * currently booting-up processor. However, on some platforms,
2266 	 * it is temporarily modified by the apicid reported as BSP
2267 	 * through MP table. Concretely:
2268 	 *
2269 	 * - arch/x86/kernel/mpparse.c: MP_processor_info()
2270 	 * - arch/x86/mm/amdtopology.c: amd_numa_init()
2271 	 *
2272 	 * This function is executed with the modified
2273 	 * boot_cpu_physical_apicid. So, disabled_cpu_apicid kernel
2274 	 * parameter doesn't work to disable APs on kdump 2nd kernel.
2275 	 *
2276 	 * Since fixing handling of boot_cpu_physical_apicid requires
2277 	 * another discussion and tests on each platform, we leave it
2278 	 * for now and here we use read_apic_id() directly in this
2279 	 * function, generic_processor_info().
2280 	 */
2281 	if (disabled_cpu_apicid != BAD_APICID &&
2282 	    disabled_cpu_apicid != read_apic_id() &&
2283 	    disabled_cpu_apicid == apicid) {
2284 		int thiscpu = num_processors + disabled_cpus;
2285 
2286 		pr_warning("APIC: Disabling requested cpu."
2287 			   " Processor %d/0x%x ignored.\n",
2288 			   thiscpu, apicid);
2289 
2290 		disabled_cpus++;
2291 		return -ENODEV;
2292 	}
2293 
2294 	/*
2295 	 * If boot cpu has not been detected yet, then only allow upto
2296 	 * nr_cpu_ids - 1 processors and keep one slot free for boot cpu
2297 	 */
2298 	if (!boot_cpu_detected && num_processors >= nr_cpu_ids - 1 &&
2299 	    apicid != boot_cpu_physical_apicid) {
2300 		int thiscpu = max + disabled_cpus - 1;
2301 
2302 		pr_warning(
2303 			"APIC: NR_CPUS/possible_cpus limit of %i almost"
2304 			" reached. Keeping one slot for boot cpu."
2305 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
2306 
2307 		disabled_cpus++;
2308 		return -ENODEV;
2309 	}
2310 
2311 	if (num_processors >= nr_cpu_ids) {
2312 		int thiscpu = max + disabled_cpus;
2313 
2314 		pr_warning("APIC: NR_CPUS/possible_cpus limit of %i "
2315 			   "reached. Processor %d/0x%x ignored.\n",
2316 			   max, thiscpu, apicid);
2317 
2318 		disabled_cpus++;
2319 		return -EINVAL;
2320 	}
2321 
2322 	if (apicid == boot_cpu_physical_apicid) {
2323 		/*
2324 		 * x86_bios_cpu_apicid is required to have processors listed
2325 		 * in same order as logical cpu numbers. Hence the first
2326 		 * entry is BSP, and so on.
2327 		 * boot_cpu_init() already hold bit 0 in cpu_present_mask
2328 		 * for BSP.
2329 		 */
2330 		cpu = 0;
2331 
2332 		/* Logical cpuid 0 is reserved for BSP. */
2333 		cpuid_to_apicid[0] = apicid;
2334 	} else {
2335 		cpu = allocate_logical_cpuid(apicid);
2336 		if (cpu < 0) {
2337 			disabled_cpus++;
2338 			return -EINVAL;
2339 		}
2340 	}
2341 
2342 	/*
2343 	 * Validate version
2344 	 */
2345 	if (version == 0x0) {
2346 		pr_warning("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
2347 			   cpu, apicid);
2348 		version = 0x10;
2349 	}
2350 
2351 	if (version != boot_cpu_apic_version) {
2352 		pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
2353 			boot_cpu_apic_version, cpu, version);
2354 	}
2355 
2356 	if (apicid > max_physical_apicid)
2357 		max_physical_apicid = apicid;
2358 
2359 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
2360 	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
2361 	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
2362 #endif
2363 #ifdef CONFIG_X86_32
2364 	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
2365 		apic->x86_32_early_logical_apicid(cpu);
2366 #endif
2367 	set_cpu_possible(cpu, true);
2368 	physid_set(apicid, phys_cpu_present_map);
2369 	set_cpu_present(cpu, true);
2370 	num_processors++;
2371 
2372 	return cpu;
2373 }
2374 
2375 int hard_smp_processor_id(void)
2376 {
2377 	return read_apic_id();
2378 }
2379 
2380 /*
2381  * Override the generic EOI implementation with an optimized version.
2382  * Only called during early boot when only one CPU is active and with
2383  * interrupts disabled, so we know this does not race with actual APIC driver
2384  * use.
2385  */
2386 void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v))
2387 {
2388 	struct apic **drv;
2389 
2390 	for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
2391 		/* Should happen once for each apic */
2392 		WARN_ON((*drv)->eoi_write == eoi_write);
2393 		(*drv)->native_eoi_write = (*drv)->eoi_write;
2394 		(*drv)->eoi_write = eoi_write;
2395 	}
2396 }
2397 
2398 static void __init apic_bsp_up_setup(void)
2399 {
2400 #ifdef CONFIG_X86_64
2401 	apic_write(APIC_ID, apic->set_apic_id(boot_cpu_physical_apicid));
2402 #else
2403 	/*
2404 	 * Hack: In case of kdump, after a crash, kernel might be booting
2405 	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
2406 	 * might be zero if read from MP tables. Get it from LAPIC.
2407 	 */
2408 # ifdef CONFIG_CRASH_DUMP
2409 	boot_cpu_physical_apicid = read_apic_id();
2410 # endif
2411 #endif
2412 	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
2413 }
2414 
2415 /**
2416  * apic_bsp_setup - Setup function for local apic and io-apic
2417  * @upmode:		Force UP mode (for APIC_init_uniprocessor)
2418  *
2419  * Returns:
2420  * apic_id of BSP APIC
2421  */
2422 void __init apic_bsp_setup(bool upmode)
2423 {
2424 	connect_bsp_APIC();
2425 	if (upmode)
2426 		apic_bsp_up_setup();
2427 	setup_local_APIC();
2428 
2429 	enable_IO_APIC();
2430 	end_local_APIC_setup();
2431 	irq_remap_enable_fault_handling();
2432 	setup_IO_APIC();
2433 }
2434 
2435 #ifdef CONFIG_UP_LATE_INIT
2436 void __init up_late_init(void)
2437 {
2438 	if (apic_intr_mode == APIC_PIC)
2439 		return;
2440 
2441 	/* Setup local timer */
2442 	x86_init.timers.setup_percpu_clockev();
2443 }
2444 #endif
2445 
2446 /*
2447  * Power management
2448  */
2449 #ifdef CONFIG_PM
2450 
2451 static struct {
2452 	/*
2453 	 * 'active' is true if the local APIC was enabled by us and
2454 	 * not the BIOS; this signifies that we are also responsible
2455 	 * for disabling it before entering apm/acpi suspend
2456 	 */
2457 	int active;
2458 	/* r/w apic fields */
2459 	unsigned int apic_id;
2460 	unsigned int apic_taskpri;
2461 	unsigned int apic_ldr;
2462 	unsigned int apic_dfr;
2463 	unsigned int apic_spiv;
2464 	unsigned int apic_lvtt;
2465 	unsigned int apic_lvtpc;
2466 	unsigned int apic_lvt0;
2467 	unsigned int apic_lvt1;
2468 	unsigned int apic_lvterr;
2469 	unsigned int apic_tmict;
2470 	unsigned int apic_tdcr;
2471 	unsigned int apic_thmr;
2472 	unsigned int apic_cmci;
2473 } apic_pm_state;
2474 
2475 static int lapic_suspend(void)
2476 {
2477 	unsigned long flags;
2478 	int maxlvt;
2479 
2480 	if (!apic_pm_state.active)
2481 		return 0;
2482 
2483 	maxlvt = lapic_get_maxlvt();
2484 
2485 	apic_pm_state.apic_id = apic_read(APIC_ID);
2486 	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2487 	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2488 	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2489 	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2490 	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2491 	if (maxlvt >= 4)
2492 		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2493 	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2494 	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2495 	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2496 	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2497 	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2498 #ifdef CONFIG_X86_THERMAL_VECTOR
2499 	if (maxlvt >= 5)
2500 		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2501 #endif
2502 #ifdef CONFIG_X86_MCE_INTEL
2503 	if (maxlvt >= 6)
2504 		apic_pm_state.apic_cmci = apic_read(APIC_LVTCMCI);
2505 #endif
2506 
2507 	local_irq_save(flags);
2508 	disable_local_APIC();
2509 
2510 	irq_remapping_disable();
2511 
2512 	local_irq_restore(flags);
2513 	return 0;
2514 }
2515 
2516 static void lapic_resume(void)
2517 {
2518 	unsigned int l, h;
2519 	unsigned long flags;
2520 	int maxlvt;
2521 
2522 	if (!apic_pm_state.active)
2523 		return;
2524 
2525 	local_irq_save(flags);
2526 
2527 	/*
2528 	 * IO-APIC and PIC have their own resume routines.
2529 	 * We just mask them here to make sure the interrupt
2530 	 * subsystem is completely quiet while we enable x2apic
2531 	 * and interrupt-remapping.
2532 	 */
2533 	mask_ioapic_entries();
2534 	legacy_pic->mask_all();
2535 
2536 	if (x2apic_mode) {
2537 		__x2apic_enable();
2538 	} else {
2539 		/*
2540 		 * Make sure the APICBASE points to the right address
2541 		 *
2542 		 * FIXME! This will be wrong if we ever support suspend on
2543 		 * SMP! We'll need to do this as part of the CPU restore!
2544 		 */
2545 		if (boot_cpu_data.x86 >= 6) {
2546 			rdmsr(MSR_IA32_APICBASE, l, h);
2547 			l &= ~MSR_IA32_APICBASE_BASE;
2548 			l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2549 			wrmsr(MSR_IA32_APICBASE, l, h);
2550 		}
2551 	}
2552 
2553 	maxlvt = lapic_get_maxlvt();
2554 	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2555 	apic_write(APIC_ID, apic_pm_state.apic_id);
2556 	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2557 	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2558 	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2559 	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2560 	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2561 	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2562 #ifdef CONFIG_X86_THERMAL_VECTOR
2563 	if (maxlvt >= 5)
2564 		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2565 #endif
2566 #ifdef CONFIG_X86_MCE_INTEL
2567 	if (maxlvt >= 6)
2568 		apic_write(APIC_LVTCMCI, apic_pm_state.apic_cmci);
2569 #endif
2570 	if (maxlvt >= 4)
2571 		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2572 	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2573 	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2574 	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2575 	apic_write(APIC_ESR, 0);
2576 	apic_read(APIC_ESR);
2577 	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2578 	apic_write(APIC_ESR, 0);
2579 	apic_read(APIC_ESR);
2580 
2581 	irq_remapping_reenable(x2apic_mode);
2582 
2583 	local_irq_restore(flags);
2584 }
2585 
2586 /*
2587  * This device has no shutdown method - fully functioning local APICs
2588  * are needed on every CPU up until machine_halt/restart/poweroff.
2589  */
2590 
2591 static struct syscore_ops lapic_syscore_ops = {
2592 	.resume		= lapic_resume,
2593 	.suspend	= lapic_suspend,
2594 };
2595 
2596 static void apic_pm_activate(void)
2597 {
2598 	apic_pm_state.active = 1;
2599 }
2600 
2601 static int __init init_lapic_sysfs(void)
2602 {
2603 	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2604 	if (boot_cpu_has(X86_FEATURE_APIC))
2605 		register_syscore_ops(&lapic_syscore_ops);
2606 
2607 	return 0;
2608 }
2609 
2610 /* local apic needs to resume before other devices access its registers. */
2611 core_initcall(init_lapic_sysfs);
2612 
2613 #else	/* CONFIG_PM */
2614 
2615 static void apic_pm_activate(void) { }
2616 
2617 #endif	/* CONFIG_PM */
2618 
2619 #ifdef CONFIG_X86_64
2620 
2621 static int multi_checked;
2622 static int multi;
2623 
2624 static int set_multi(const struct dmi_system_id *d)
2625 {
2626 	if (multi)
2627 		return 0;
2628 	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2629 	multi = 1;
2630 	return 0;
2631 }
2632 
2633 static const struct dmi_system_id multi_dmi_table[] = {
2634 	{
2635 		.callback = set_multi,
2636 		.ident = "IBM System Summit2",
2637 		.matches = {
2638 			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2639 			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2640 		},
2641 	},
2642 	{}
2643 };
2644 
2645 static void dmi_check_multi(void)
2646 {
2647 	if (multi_checked)
2648 		return;
2649 
2650 	dmi_check_system(multi_dmi_table);
2651 	multi_checked = 1;
2652 }
2653 
2654 /*
2655  * apic_is_clustered_box() -- Check if we can expect good TSC
2656  *
2657  * Thus far, the major user of this is IBM's Summit2 series:
2658  * Clustered boxes may have unsynced TSC problems if they are
2659  * multi-chassis.
2660  * Use DMI to check them
2661  */
2662 int apic_is_clustered_box(void)
2663 {
2664 	dmi_check_multi();
2665 	return multi;
2666 }
2667 #endif
2668 
2669 /*
2670  * APIC command line parameters
2671  */
2672 static int __init setup_disableapic(char *arg)
2673 {
2674 	disable_apic = 1;
2675 	setup_clear_cpu_cap(X86_FEATURE_APIC);
2676 	return 0;
2677 }
2678 early_param("disableapic", setup_disableapic);
2679 
2680 /* same as disableapic, for compatibility */
2681 static int __init setup_nolapic(char *arg)
2682 {
2683 	return setup_disableapic(arg);
2684 }
2685 early_param("nolapic", setup_nolapic);
2686 
2687 static int __init parse_lapic_timer_c2_ok(char *arg)
2688 {
2689 	local_apic_timer_c2_ok = 1;
2690 	return 0;
2691 }
2692 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2693 
2694 static int __init parse_disable_apic_timer(char *arg)
2695 {
2696 	disable_apic_timer = 1;
2697 	return 0;
2698 }
2699 early_param("noapictimer", parse_disable_apic_timer);
2700 
2701 static int __init parse_nolapic_timer(char *arg)
2702 {
2703 	disable_apic_timer = 1;
2704 	return 0;
2705 }
2706 early_param("nolapic_timer", parse_nolapic_timer);
2707 
2708 static int __init apic_set_verbosity(char *arg)
2709 {
2710 	if (!arg)  {
2711 #ifdef CONFIG_X86_64
2712 		skip_ioapic_setup = 0;
2713 		return 0;
2714 #endif
2715 		return -EINVAL;
2716 	}
2717 
2718 	if (strcmp("debug", arg) == 0)
2719 		apic_verbosity = APIC_DEBUG;
2720 	else if (strcmp("verbose", arg) == 0)
2721 		apic_verbosity = APIC_VERBOSE;
2722 #ifdef CONFIG_X86_64
2723 	else {
2724 		pr_warning("APIC Verbosity level %s not recognised"
2725 			" use apic=verbose or apic=debug\n", arg);
2726 		return -EINVAL;
2727 	}
2728 #endif
2729 
2730 	return 0;
2731 }
2732 early_param("apic", apic_set_verbosity);
2733 
2734 static int __init lapic_insert_resource(void)
2735 {
2736 	if (!apic_phys)
2737 		return -1;
2738 
2739 	/* Put local APIC into the resource map. */
2740 	lapic_resource.start = apic_phys;
2741 	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2742 	insert_resource(&iomem_resource, &lapic_resource);
2743 
2744 	return 0;
2745 }
2746 
2747 /*
2748  * need call insert after e820__reserve_resources()
2749  * that is using request_resource
2750  */
2751 late_initcall(lapic_insert_resource);
2752 
2753 static int __init apic_set_disabled_cpu_apicid(char *arg)
2754 {
2755 	if (!arg || !get_option(&arg, &disabled_cpu_apicid))
2756 		return -EINVAL;
2757 
2758 	return 0;
2759 }
2760 early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);
2761 
2762 static int __init apic_set_extnmi(char *arg)
2763 {
2764 	if (!arg)
2765 		return -EINVAL;
2766 
2767 	if (!strncmp("all", arg, 3))
2768 		apic_extnmi = APIC_EXTNMI_ALL;
2769 	else if (!strncmp("none", arg, 4))
2770 		apic_extnmi = APIC_EXTNMI_NONE;
2771 	else if (!strncmp("bsp", arg, 3))
2772 		apic_extnmi = APIC_EXTNMI_BSP;
2773 	else {
2774 		pr_warn("Unknown external NMI delivery mode `%s' ignored\n", arg);
2775 		return -EINVAL;
2776 	}
2777 
2778 	return 0;
2779 }
2780 early_param("apic_extnmi", apic_set_extnmi);
2781