xref: /openbmc/linux/arch/x86/kernel/apic/apic.c (revision 58f9d806)
1 /*
2  *	Local APIC handling, local APIC timers
3  *
4  *	(c) 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
5  *
6  *	Fixes
7  *	Maciej W. Rozycki	:	Bits for genuine 82489DX APICs;
8  *					thanks to Eric Gilmore
9  *					and Rolf G. Tews
10  *					for testing these extensively.
11  *	Maciej W. Rozycki	:	Various updates and fixes.
12  *	Mikael Pettersson	:	Power Management for UP-APIC.
13  *	Pavel Machek and
14  *	Mikael Pettersson	:	PM converted to driver model.
15  */
16 
17 #include <linux/perf_event.h>
18 #include <linux/kernel_stat.h>
19 #include <linux/mc146818rtc.h>
20 #include <linux/acpi_pmtmr.h>
21 #include <linux/clockchips.h>
22 #include <linux/interrupt.h>
23 #include <linux/memblock.h>
24 #include <linux/ftrace.h>
25 #include <linux/ioport.h>
26 #include <linux/export.h>
27 #include <linux/syscore_ops.h>
28 #include <linux/delay.h>
29 #include <linux/timex.h>
30 #include <linux/i8253.h>
31 #include <linux/dmar.h>
32 #include <linux/init.h>
33 #include <linux/cpu.h>
34 #include <linux/dmi.h>
35 #include <linux/smp.h>
36 #include <linux/mm.h>
37 
38 #include <asm/trace/irq_vectors.h>
39 #include <asm/irq_remapping.h>
40 #include <asm/perf_event.h>
41 #include <asm/x86_init.h>
42 #include <asm/pgalloc.h>
43 #include <linux/atomic.h>
44 #include <asm/mpspec.h>
45 #include <asm/i8259.h>
46 #include <asm/proto.h>
47 #include <asm/apic.h>
48 #include <asm/io_apic.h>
49 #include <asm/desc.h>
50 #include <asm/hpet.h>
51 #include <asm/mtrr.h>
52 #include <asm/time.h>
53 #include <asm/smp.h>
54 #include <asm/mce.h>
55 #include <asm/tsc.h>
56 #include <asm/hypervisor.h>
57 #include <asm/cpu_device_id.h>
58 #include <asm/intel-family.h>
59 #include <asm/irq_regs.h>
60 
61 unsigned int num_processors;
62 
63 unsigned disabled_cpus;
64 
65 /* Processor that is doing the boot up */
66 unsigned int boot_cpu_physical_apicid = -1U;
67 EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
68 
69 u8 boot_cpu_apic_version;
70 
71 /*
72  * The highest APIC ID seen during enumeration.
73  */
74 static unsigned int max_physical_apicid;
75 
76 /*
77  * Bitmask of physically existing CPUs:
78  */
79 physid_mask_t phys_cpu_present_map;
80 
81 /*
82  * Processor to be disabled specified by kernel parameter
83  * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
84  * avoid undefined behaviour caused by sending INIT from AP to BSP.
85  */
86 static unsigned int disabled_cpu_apicid __read_mostly = BAD_APICID;
87 
88 /*
89  * This variable controls which CPUs receive external NMIs.  By default,
90  * external NMIs are delivered only to the BSP.
91  */
92 static int apic_extnmi = APIC_EXTNMI_BSP;
93 
94 /*
95  * Map cpu index to physical APIC ID
96  */
97 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid, BAD_APICID);
98 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_bios_cpu_apicid, BAD_APICID);
99 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, U32_MAX);
100 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
101 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
102 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
103 
104 #ifdef CONFIG_X86_32
105 
106 /*
107  * On x86_32, the mapping between cpu and logical apicid may vary
108  * depending on apic in use.  The following early percpu variable is
109  * used for the mapping.  This is where the behaviors of x86_64 and 32
110  * actually diverge.  Let's keep it ugly for now.
111  */
112 DEFINE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid, BAD_APICID);
113 
114 /* Local APIC was disabled by the BIOS and enabled by the kernel */
115 static int enabled_via_apicbase;
116 
117 /*
118  * Handle interrupt mode configuration register (IMCR).
119  * This register controls whether the interrupt signals
120  * that reach the BSP come from the master PIC or from the
121  * local APIC. Before entering Symmetric I/O Mode, either
122  * the BIOS or the operating system must switch out of
123  * PIC Mode by changing the IMCR.
124  */
125 static inline void imcr_pic_to_apic(void)
126 {
127 	/* select IMCR register */
128 	outb(0x70, 0x22);
129 	/* NMI and 8259 INTR go through APIC */
130 	outb(0x01, 0x23);
131 }
132 
133 static inline void imcr_apic_to_pic(void)
134 {
135 	/* select IMCR register */
136 	outb(0x70, 0x22);
137 	/* NMI and 8259 INTR go directly to BSP */
138 	outb(0x00, 0x23);
139 }
140 #endif
141 
142 /*
143  * Knob to control our willingness to enable the local APIC.
144  *
145  * +1=force-enable
146  */
147 static int force_enable_local_apic __initdata;
148 
149 /*
150  * APIC command line parameters
151  */
152 static int __init parse_lapic(char *arg)
153 {
154 	if (IS_ENABLED(CONFIG_X86_32) && !arg)
155 		force_enable_local_apic = 1;
156 	else if (arg && !strncmp(arg, "notscdeadline", 13))
157 		setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
158 	return 0;
159 }
160 early_param("lapic", parse_lapic);
161 
162 #ifdef CONFIG_X86_64
163 static int apic_calibrate_pmtmr __initdata;
164 static __init int setup_apicpmtimer(char *s)
165 {
166 	apic_calibrate_pmtmr = 1;
167 	notsc_setup(NULL);
168 	return 0;
169 }
170 __setup("apicpmtimer", setup_apicpmtimer);
171 #endif
172 
173 unsigned long mp_lapic_addr;
174 int disable_apic;
175 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
176 static int disable_apic_timer __initdata;
177 /* Local APIC timer works in C2 */
178 int local_apic_timer_c2_ok;
179 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
180 
181 /*
182  * Debug level, exported for io_apic.c
183  */
184 unsigned int apic_verbosity;
185 
186 int pic_mode;
187 
188 /* Have we found an MP table */
189 int smp_found_config;
190 
191 static struct resource lapic_resource = {
192 	.name = "Local APIC",
193 	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
194 };
195 
196 unsigned int lapic_timer_frequency = 0;
197 
198 static void apic_pm_activate(void);
199 
200 static unsigned long apic_phys;
201 
202 /*
203  * Get the LAPIC version
204  */
205 static inline int lapic_get_version(void)
206 {
207 	return GET_APIC_VERSION(apic_read(APIC_LVR));
208 }
209 
210 /*
211  * Check, if the APIC is integrated or a separate chip
212  */
213 static inline int lapic_is_integrated(void)
214 {
215 	return APIC_INTEGRATED(lapic_get_version());
216 }
217 
218 /*
219  * Check, whether this is a modern or a first generation APIC
220  */
221 static int modern_apic(void)
222 {
223 	/* AMD systems use old APIC versions, so check the CPU */
224 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
225 	    boot_cpu_data.x86 >= 0xf)
226 		return 1;
227 
228 	/* Hygon systems use modern APIC */
229 	if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
230 		return 1;
231 
232 	return lapic_get_version() >= 0x14;
233 }
234 
235 /*
236  * right after this call apic become NOOP driven
237  * so apic->write/read doesn't do anything
238  */
239 static void __init apic_disable(void)
240 {
241 	pr_info("APIC: switched to apic NOOP\n");
242 	apic = &apic_noop;
243 }
244 
245 void native_apic_wait_icr_idle(void)
246 {
247 	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
248 		cpu_relax();
249 }
250 
251 u32 native_safe_apic_wait_icr_idle(void)
252 {
253 	u32 send_status;
254 	int timeout;
255 
256 	timeout = 0;
257 	do {
258 		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
259 		if (!send_status)
260 			break;
261 		inc_irq_stat(icr_read_retry_count);
262 		udelay(100);
263 	} while (timeout++ < 1000);
264 
265 	return send_status;
266 }
267 
268 void native_apic_icr_write(u32 low, u32 id)
269 {
270 	unsigned long flags;
271 
272 	local_irq_save(flags);
273 	apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
274 	apic_write(APIC_ICR, low);
275 	local_irq_restore(flags);
276 }
277 
278 u64 native_apic_icr_read(void)
279 {
280 	u32 icr1, icr2;
281 
282 	icr2 = apic_read(APIC_ICR2);
283 	icr1 = apic_read(APIC_ICR);
284 
285 	return icr1 | ((u64)icr2 << 32);
286 }
287 
288 #ifdef CONFIG_X86_32
289 /**
290  * get_physical_broadcast - Get number of physical broadcast IDs
291  */
292 int get_physical_broadcast(void)
293 {
294 	return modern_apic() ? 0xff : 0xf;
295 }
296 #endif
297 
298 /**
299  * lapic_get_maxlvt - get the maximum number of local vector table entries
300  */
301 int lapic_get_maxlvt(void)
302 {
303 	/*
304 	 * - we always have APIC integrated on 64bit mode
305 	 * - 82489DXs do not report # of LVT entries
306 	 */
307 	return lapic_is_integrated() ? GET_APIC_MAXLVT(apic_read(APIC_LVR)) : 2;
308 }
309 
310 /*
311  * Local APIC timer
312  */
313 
314 /* Clock divisor */
315 #define APIC_DIVISOR 16
316 #define TSC_DIVISOR  8
317 
318 /*
319  * This function sets up the local APIC timer, with a timeout of
320  * 'clocks' APIC bus clock. During calibration we actually call
321  * this function twice on the boot CPU, once with a bogus timeout
322  * value, second time for real. The other (noncalibrating) CPUs
323  * call this function only once, with the real, calibrated value.
324  *
325  * We do reads before writes even if unnecessary, to get around the
326  * P5 APIC double write bug.
327  */
328 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
329 {
330 	unsigned int lvtt_value, tmp_value;
331 
332 	lvtt_value = LOCAL_TIMER_VECTOR;
333 	if (!oneshot)
334 		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
335 	else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
336 		lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE;
337 
338 	if (!lapic_is_integrated())
339 		lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
340 
341 	if (!irqen)
342 		lvtt_value |= APIC_LVT_MASKED;
343 
344 	apic_write(APIC_LVTT, lvtt_value);
345 
346 	if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) {
347 		/*
348 		 * See Intel SDM: TSC-Deadline Mode chapter. In xAPIC mode,
349 		 * writing to the APIC LVTT and TSC_DEADLINE MSR isn't serialized.
350 		 * According to Intel, MFENCE can do the serialization here.
351 		 */
352 		asm volatile("mfence" : : : "memory");
353 
354 		printk_once(KERN_DEBUG "TSC deadline timer enabled\n");
355 		return;
356 	}
357 
358 	/*
359 	 * Divide PICLK by 16
360 	 */
361 	tmp_value = apic_read(APIC_TDCR);
362 	apic_write(APIC_TDCR,
363 		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
364 		APIC_TDR_DIV_16);
365 
366 	if (!oneshot)
367 		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
368 }
369 
370 /*
371  * Setup extended LVT, AMD specific
372  *
373  * Software should use the LVT offsets the BIOS provides.  The offsets
374  * are determined by the subsystems using it like those for MCE
375  * threshold or IBS.  On K8 only offset 0 (APIC500) and MCE interrupts
376  * are supported. Beginning with family 10h at least 4 offsets are
377  * available.
378  *
379  * Since the offsets must be consistent for all cores, we keep track
380  * of the LVT offsets in software and reserve the offset for the same
381  * vector also to be used on other cores. An offset is freed by
382  * setting the entry to APIC_EILVT_MASKED.
383  *
384  * If the BIOS is right, there should be no conflicts. Otherwise a
385  * "[Firmware Bug]: ..." error message is generated. However, if
386  * software does not properly determines the offsets, it is not
387  * necessarily a BIOS bug.
388  */
389 
390 static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
391 
392 static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
393 {
394 	return (old & APIC_EILVT_MASKED)
395 		|| (new == APIC_EILVT_MASKED)
396 		|| ((new & ~APIC_EILVT_MASKED) == old);
397 }
398 
399 static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
400 {
401 	unsigned int rsvd, vector;
402 
403 	if (offset >= APIC_EILVT_NR_MAX)
404 		return ~0;
405 
406 	rsvd = atomic_read(&eilvt_offsets[offset]);
407 	do {
408 		vector = rsvd & ~APIC_EILVT_MASKED;	/* 0: unassigned */
409 		if (vector && !eilvt_entry_is_changeable(vector, new))
410 			/* may not change if vectors are different */
411 			return rsvd;
412 		rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new);
413 	} while (rsvd != new);
414 
415 	rsvd &= ~APIC_EILVT_MASKED;
416 	if (rsvd && rsvd != vector)
417 		pr_info("LVT offset %d assigned for vector 0x%02x\n",
418 			offset, rsvd);
419 
420 	return new;
421 }
422 
423 /*
424  * If mask=1, the LVT entry does not generate interrupts while mask=0
425  * enables the vector. See also the BKDGs. Must be called with
426  * preemption disabled.
427  */
428 
429 int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
430 {
431 	unsigned long reg = APIC_EILVTn(offset);
432 	unsigned int new, old, reserved;
433 
434 	new = (mask << 16) | (msg_type << 8) | vector;
435 	old = apic_read(reg);
436 	reserved = reserve_eilvt_offset(offset, new);
437 
438 	if (reserved != new) {
439 		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
440 		       "vector 0x%x, but the register is already in use for "
441 		       "vector 0x%x on another cpu\n",
442 		       smp_processor_id(), reg, offset, new, reserved);
443 		return -EINVAL;
444 	}
445 
446 	if (!eilvt_entry_is_changeable(old, new)) {
447 		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
448 		       "vector 0x%x, but the register is already in use for "
449 		       "vector 0x%x on this cpu\n",
450 		       smp_processor_id(), reg, offset, new, old);
451 		return -EBUSY;
452 	}
453 
454 	apic_write(reg, new);
455 
456 	return 0;
457 }
458 EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
459 
460 /*
461  * Program the next event, relative to now
462  */
463 static int lapic_next_event(unsigned long delta,
464 			    struct clock_event_device *evt)
465 {
466 	apic_write(APIC_TMICT, delta);
467 	return 0;
468 }
469 
470 static int lapic_next_deadline(unsigned long delta,
471 			       struct clock_event_device *evt)
472 {
473 	u64 tsc;
474 
475 	tsc = rdtsc();
476 	wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR));
477 	return 0;
478 }
479 
480 static int lapic_timer_shutdown(struct clock_event_device *evt)
481 {
482 	unsigned int v;
483 
484 	/* Lapic used as dummy for broadcast ? */
485 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
486 		return 0;
487 
488 	v = apic_read(APIC_LVTT);
489 	v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
490 	apic_write(APIC_LVTT, v);
491 	apic_write(APIC_TMICT, 0);
492 	return 0;
493 }
494 
495 static inline int
496 lapic_timer_set_periodic_oneshot(struct clock_event_device *evt, bool oneshot)
497 {
498 	/* Lapic used as dummy for broadcast ? */
499 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
500 		return 0;
501 
502 	__setup_APIC_LVTT(lapic_timer_frequency, oneshot, 1);
503 	return 0;
504 }
505 
506 static int lapic_timer_set_periodic(struct clock_event_device *evt)
507 {
508 	return lapic_timer_set_periodic_oneshot(evt, false);
509 }
510 
511 static int lapic_timer_set_oneshot(struct clock_event_device *evt)
512 {
513 	return lapic_timer_set_periodic_oneshot(evt, true);
514 }
515 
516 /*
517  * Local APIC timer broadcast function
518  */
519 static void lapic_timer_broadcast(const struct cpumask *mask)
520 {
521 #ifdef CONFIG_SMP
522 	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
523 #endif
524 }
525 
526 
527 /*
528  * The local apic timer can be used for any function which is CPU local.
529  */
530 static struct clock_event_device lapic_clockevent = {
531 	.name				= "lapic",
532 	.features			= CLOCK_EVT_FEAT_PERIODIC |
533 					  CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP
534 					  | CLOCK_EVT_FEAT_DUMMY,
535 	.shift				= 32,
536 	.set_state_shutdown		= lapic_timer_shutdown,
537 	.set_state_periodic		= lapic_timer_set_periodic,
538 	.set_state_oneshot		= lapic_timer_set_oneshot,
539 	.set_state_oneshot_stopped	= lapic_timer_shutdown,
540 	.set_next_event			= lapic_next_event,
541 	.broadcast			= lapic_timer_broadcast,
542 	.rating				= 100,
543 	.irq				= -1,
544 };
545 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
546 
547 #define DEADLINE_MODEL_MATCH_FUNC(model, func)	\
548 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&func }
549 
550 #define DEADLINE_MODEL_MATCH_REV(model, rev)	\
551 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)rev }
552 
553 static u32 hsx_deadline_rev(void)
554 {
555 	switch (boot_cpu_data.x86_stepping) {
556 	case 0x02: return 0x3a; /* EP */
557 	case 0x04: return 0x0f; /* EX */
558 	}
559 
560 	return ~0U;
561 }
562 
563 static u32 bdx_deadline_rev(void)
564 {
565 	switch (boot_cpu_data.x86_stepping) {
566 	case 0x02: return 0x00000011;
567 	case 0x03: return 0x0700000e;
568 	case 0x04: return 0x0f00000c;
569 	case 0x05: return 0x0e000003;
570 	}
571 
572 	return ~0U;
573 }
574 
575 static u32 skx_deadline_rev(void)
576 {
577 	switch (boot_cpu_data.x86_stepping) {
578 	case 0x03: return 0x01000136;
579 	case 0x04: return 0x02000014;
580 	}
581 
582 	if (boot_cpu_data.x86_stepping > 4)
583 		return 0;
584 
585 	return ~0U;
586 }
587 
588 static const struct x86_cpu_id deadline_match[] = {
589 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_HASWELL_X,	hsx_deadline_rev),
590 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_X,	0x0b000020),
591 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_BROADWELL_XEON_D,	bdx_deadline_rev),
592 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_SKYLAKE_X,	skx_deadline_rev),
593 
594 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_CORE,	0x22),
595 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_ULT,	0x20),
596 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_GT3E,	0x17),
597 
598 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_CORE,	0x25),
599 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_GT3E,	0x17),
600 
601 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_MOBILE,	0xb2),
602 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_DESKTOP,	0xb2),
603 
604 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_MOBILE,	0x52),
605 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_DESKTOP,	0x52),
606 
607 	{},
608 };
609 
610 static void apic_check_deadline_errata(void)
611 {
612 	const struct x86_cpu_id *m;
613 	u32 rev;
614 
615 	if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER) ||
616 	    boot_cpu_has(X86_FEATURE_HYPERVISOR))
617 		return;
618 
619 	m = x86_match_cpu(deadline_match);
620 	if (!m)
621 		return;
622 
623 	/*
624 	 * Function pointers will have the MSB set due to address layout,
625 	 * immediate revisions will not.
626 	 */
627 	if ((long)m->driver_data < 0)
628 		rev = ((u32 (*)(void))(m->driver_data))();
629 	else
630 		rev = (u32)m->driver_data;
631 
632 	if (boot_cpu_data.microcode >= rev)
633 		return;
634 
635 	setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
636 	pr_err(FW_BUG "TSC_DEADLINE disabled due to Errata; "
637 	       "please update microcode to version: 0x%x (or later)\n", rev);
638 }
639 
640 /*
641  * Setup the local APIC timer for this CPU. Copy the initialized values
642  * of the boot CPU and register the clock event in the framework.
643  */
644 static void setup_APIC_timer(void)
645 {
646 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
647 
648 	if (this_cpu_has(X86_FEATURE_ARAT)) {
649 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
650 		/* Make LAPIC timer preferrable over percpu HPET */
651 		lapic_clockevent.rating = 150;
652 	}
653 
654 	memcpy(levt, &lapic_clockevent, sizeof(*levt));
655 	levt->cpumask = cpumask_of(smp_processor_id());
656 
657 	if (this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
658 		levt->name = "lapic-deadline";
659 		levt->features &= ~(CLOCK_EVT_FEAT_PERIODIC |
660 				    CLOCK_EVT_FEAT_DUMMY);
661 		levt->set_next_event = lapic_next_deadline;
662 		clockevents_config_and_register(levt,
663 						tsc_khz * (1000 / TSC_DIVISOR),
664 						0xF, ~0UL);
665 	} else
666 		clockevents_register_device(levt);
667 }
668 
669 /*
670  * Install the updated TSC frequency from recalibration at the TSC
671  * deadline clockevent devices.
672  */
673 static void __lapic_update_tsc_freq(void *info)
674 {
675 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
676 
677 	if (!this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
678 		return;
679 
680 	clockevents_update_freq(levt, tsc_khz * (1000 / TSC_DIVISOR));
681 }
682 
683 void lapic_update_tsc_freq(void)
684 {
685 	/*
686 	 * The clockevent device's ->mult and ->shift can both be
687 	 * changed. In order to avoid races, schedule the frequency
688 	 * update code on each CPU.
689 	 */
690 	on_each_cpu(__lapic_update_tsc_freq, NULL, 0);
691 }
692 
693 /*
694  * In this functions we calibrate APIC bus clocks to the external timer.
695  *
696  * We want to do the calibration only once since we want to have local timer
697  * irqs syncron. CPUs connected by the same APIC bus have the very same bus
698  * frequency.
699  *
700  * This was previously done by reading the PIT/HPET and waiting for a wrap
701  * around to find out, that a tick has elapsed. I have a box, where the PIT
702  * readout is broken, so it never gets out of the wait loop again. This was
703  * also reported by others.
704  *
705  * Monitoring the jiffies value is inaccurate and the clockevents
706  * infrastructure allows us to do a simple substitution of the interrupt
707  * handler.
708  *
709  * The calibration routine also uses the pm_timer when possible, as the PIT
710  * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
711  * back to normal later in the boot process).
712  */
713 
714 #define LAPIC_CAL_LOOPS		(HZ/10)
715 
716 static __initdata int lapic_cal_loops = -1;
717 static __initdata long lapic_cal_t1, lapic_cal_t2;
718 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
719 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
720 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
721 
722 /*
723  * Temporary interrupt handler.
724  */
725 static void __init lapic_cal_handler(struct clock_event_device *dev)
726 {
727 	unsigned long long tsc = 0;
728 	long tapic = apic_read(APIC_TMCCT);
729 	unsigned long pm = acpi_pm_read_early();
730 
731 	if (boot_cpu_has(X86_FEATURE_TSC))
732 		tsc = rdtsc();
733 
734 	switch (lapic_cal_loops++) {
735 	case 0:
736 		lapic_cal_t1 = tapic;
737 		lapic_cal_tsc1 = tsc;
738 		lapic_cal_pm1 = pm;
739 		lapic_cal_j1 = jiffies;
740 		break;
741 
742 	case LAPIC_CAL_LOOPS:
743 		lapic_cal_t2 = tapic;
744 		lapic_cal_tsc2 = tsc;
745 		if (pm < lapic_cal_pm1)
746 			pm += ACPI_PM_OVRRUN;
747 		lapic_cal_pm2 = pm;
748 		lapic_cal_j2 = jiffies;
749 		break;
750 	}
751 }
752 
753 static int __init
754 calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
755 {
756 	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
757 	const long pm_thresh = pm_100ms / 100;
758 	unsigned long mult;
759 	u64 res;
760 
761 #ifndef CONFIG_X86_PM_TIMER
762 	return -1;
763 #endif
764 
765 	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
766 
767 	/* Check, if the PM timer is available */
768 	if (!deltapm)
769 		return -1;
770 
771 	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
772 
773 	if (deltapm > (pm_100ms - pm_thresh) &&
774 	    deltapm < (pm_100ms + pm_thresh)) {
775 		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
776 		return 0;
777 	}
778 
779 	res = (((u64)deltapm) *  mult) >> 22;
780 	do_div(res, 1000000);
781 	pr_warning("APIC calibration not consistent "
782 		   "with PM-Timer: %ldms instead of 100ms\n",(long)res);
783 
784 	/* Correct the lapic counter value */
785 	res = (((u64)(*delta)) * pm_100ms);
786 	do_div(res, deltapm);
787 	pr_info("APIC delta adjusted to PM-Timer: "
788 		"%lu (%ld)\n", (unsigned long)res, *delta);
789 	*delta = (long)res;
790 
791 	/* Correct the tsc counter value */
792 	if (boot_cpu_has(X86_FEATURE_TSC)) {
793 		res = (((u64)(*deltatsc)) * pm_100ms);
794 		do_div(res, deltapm);
795 		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
796 					  "PM-Timer: %lu (%ld)\n",
797 					(unsigned long)res, *deltatsc);
798 		*deltatsc = (long)res;
799 	}
800 
801 	return 0;
802 }
803 
804 static int __init calibrate_APIC_clock(void)
805 {
806 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
807 	void (*real_handler)(struct clock_event_device *dev);
808 	unsigned long deltaj;
809 	long delta, deltatsc;
810 	int pm_referenced = 0;
811 
812 	/**
813 	 * check if lapic timer has already been calibrated by platform
814 	 * specific routine, such as tsc calibration code. if so, we just fill
815 	 * in the clockevent structure and return.
816 	 */
817 
818 	if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
819 		return 0;
820 	} else if (lapic_timer_frequency) {
821 		apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
822 				lapic_timer_frequency);
823 		lapic_clockevent.mult = div_sc(lapic_timer_frequency/APIC_DIVISOR,
824 					TICK_NSEC, lapic_clockevent.shift);
825 		lapic_clockevent.max_delta_ns =
826 			clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
827 		lapic_clockevent.max_delta_ticks = 0x7FFFFF;
828 		lapic_clockevent.min_delta_ns =
829 			clockevent_delta2ns(0xF, &lapic_clockevent);
830 		lapic_clockevent.min_delta_ticks = 0xF;
831 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
832 		return 0;
833 	}
834 
835 	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
836 		    "calibrating APIC timer ...\n");
837 
838 	local_irq_disable();
839 
840 	/* Replace the global interrupt handler */
841 	real_handler = global_clock_event->event_handler;
842 	global_clock_event->event_handler = lapic_cal_handler;
843 
844 	/*
845 	 * Setup the APIC counter to maximum. There is no way the lapic
846 	 * can underflow in the 100ms detection time frame
847 	 */
848 	__setup_APIC_LVTT(0xffffffff, 0, 0);
849 
850 	/* Let the interrupts run */
851 	local_irq_enable();
852 
853 	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
854 		cpu_relax();
855 
856 	local_irq_disable();
857 
858 	/* Restore the real event handler */
859 	global_clock_event->event_handler = real_handler;
860 
861 	/* Build delta t1-t2 as apic timer counts down */
862 	delta = lapic_cal_t1 - lapic_cal_t2;
863 	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
864 
865 	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
866 
867 	/* we trust the PM based calibration if possible */
868 	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
869 					&delta, &deltatsc);
870 
871 	/* Calculate the scaled math multiplication factor */
872 	lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
873 				       lapic_clockevent.shift);
874 	lapic_clockevent.max_delta_ns =
875 		clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
876 	lapic_clockevent.max_delta_ticks = 0x7FFFFFFF;
877 	lapic_clockevent.min_delta_ns =
878 		clockevent_delta2ns(0xF, &lapic_clockevent);
879 	lapic_clockevent.min_delta_ticks = 0xF;
880 
881 	lapic_timer_frequency = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
882 
883 	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
884 	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
885 	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
886 		    lapic_timer_frequency);
887 
888 	if (boot_cpu_has(X86_FEATURE_TSC)) {
889 		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
890 			    "%ld.%04ld MHz.\n",
891 			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
892 			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
893 	}
894 
895 	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
896 		    "%u.%04u MHz.\n",
897 		    lapic_timer_frequency / (1000000 / HZ),
898 		    lapic_timer_frequency % (1000000 / HZ));
899 
900 	/*
901 	 * Do a sanity check on the APIC calibration result
902 	 */
903 	if (lapic_timer_frequency < (1000000 / HZ)) {
904 		local_irq_enable();
905 		pr_warning("APIC frequency too slow, disabling apic timer\n");
906 		return -1;
907 	}
908 
909 	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
910 
911 	/*
912 	 * PM timer calibration failed or not turned on
913 	 * so lets try APIC timer based calibration
914 	 */
915 	if (!pm_referenced) {
916 		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
917 
918 		/*
919 		 * Setup the apic timer manually
920 		 */
921 		levt->event_handler = lapic_cal_handler;
922 		lapic_timer_set_periodic(levt);
923 		lapic_cal_loops = -1;
924 
925 		/* Let the interrupts run */
926 		local_irq_enable();
927 
928 		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
929 			cpu_relax();
930 
931 		/* Stop the lapic timer */
932 		local_irq_disable();
933 		lapic_timer_shutdown(levt);
934 
935 		/* Jiffies delta */
936 		deltaj = lapic_cal_j2 - lapic_cal_j1;
937 		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
938 
939 		/* Check, if the jiffies result is consistent */
940 		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
941 			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
942 		else
943 			levt->features |= CLOCK_EVT_FEAT_DUMMY;
944 	}
945 	local_irq_enable();
946 
947 	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
948 		pr_warning("APIC timer disabled due to verification failure\n");
949 		return -1;
950 	}
951 
952 	return 0;
953 }
954 
955 /*
956  * Setup the boot APIC
957  *
958  * Calibrate and verify the result.
959  */
960 void __init setup_boot_APIC_clock(void)
961 {
962 	/*
963 	 * The local apic timer can be disabled via the kernel
964 	 * commandline or from the CPU detection code. Register the lapic
965 	 * timer as a dummy clock event source on SMP systems, so the
966 	 * broadcast mechanism is used. On UP systems simply ignore it.
967 	 */
968 	if (disable_apic_timer) {
969 		pr_info("Disabling APIC timer\n");
970 		/* No broadcast on UP ! */
971 		if (num_possible_cpus() > 1) {
972 			lapic_clockevent.mult = 1;
973 			setup_APIC_timer();
974 		}
975 		return;
976 	}
977 
978 	if (calibrate_APIC_clock()) {
979 		/* No broadcast on UP ! */
980 		if (num_possible_cpus() > 1)
981 			setup_APIC_timer();
982 		return;
983 	}
984 
985 	/*
986 	 * If nmi_watchdog is set to IO_APIC, we need the
987 	 * PIT/HPET going.  Otherwise register lapic as a dummy
988 	 * device.
989 	 */
990 	lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
991 
992 	/* Setup the lapic or request the broadcast */
993 	setup_APIC_timer();
994 	amd_e400_c1e_apic_setup();
995 }
996 
997 void setup_secondary_APIC_clock(void)
998 {
999 	setup_APIC_timer();
1000 	amd_e400_c1e_apic_setup();
1001 }
1002 
1003 /*
1004  * The guts of the apic timer interrupt
1005  */
1006 static void local_apic_timer_interrupt(void)
1007 {
1008 	struct clock_event_device *evt = this_cpu_ptr(&lapic_events);
1009 
1010 	/*
1011 	 * Normally we should not be here till LAPIC has been initialized but
1012 	 * in some cases like kdump, its possible that there is a pending LAPIC
1013 	 * timer interrupt from previous kernel's context and is delivered in
1014 	 * new kernel the moment interrupts are enabled.
1015 	 *
1016 	 * Interrupts are enabled early and LAPIC is setup much later, hence
1017 	 * its possible that when we get here evt->event_handler is NULL.
1018 	 * Check for event_handler being NULL and discard the interrupt as
1019 	 * spurious.
1020 	 */
1021 	if (!evt->event_handler) {
1022 		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n",
1023 			   smp_processor_id());
1024 		/* Switch it off */
1025 		lapic_timer_shutdown(evt);
1026 		return;
1027 	}
1028 
1029 	/*
1030 	 * the NMI deadlock-detector uses this.
1031 	 */
1032 	inc_irq_stat(apic_timer_irqs);
1033 
1034 	evt->event_handler(evt);
1035 }
1036 
1037 /*
1038  * Local APIC timer interrupt. This is the most natural way for doing
1039  * local interrupts, but local timer interrupts can be emulated by
1040  * broadcast interrupts too. [in case the hw doesn't support APIC timers]
1041  *
1042  * [ if a single-CPU system runs an SMP kernel then we call the local
1043  *   interrupt as well. Thus we cannot inline the local irq ... ]
1044  */
1045 __visible void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
1046 {
1047 	struct pt_regs *old_regs = set_irq_regs(regs);
1048 
1049 	/*
1050 	 * NOTE! We'd better ACK the irq immediately,
1051 	 * because timer handling can be slow.
1052 	 *
1053 	 * update_process_times() expects us to have done irq_enter().
1054 	 * Besides, if we don't timer interrupts ignore the global
1055 	 * interrupt lock, which is the WrongThing (tm) to do.
1056 	 */
1057 	entering_ack_irq();
1058 	trace_local_timer_entry(LOCAL_TIMER_VECTOR);
1059 	local_apic_timer_interrupt();
1060 	trace_local_timer_exit(LOCAL_TIMER_VECTOR);
1061 	exiting_irq();
1062 
1063 	set_irq_regs(old_regs);
1064 }
1065 
1066 int setup_profiling_timer(unsigned int multiplier)
1067 {
1068 	return -EINVAL;
1069 }
1070 
1071 /*
1072  * Local APIC start and shutdown
1073  */
1074 
1075 /**
1076  * clear_local_APIC - shutdown the local APIC
1077  *
1078  * This is called, when a CPU is disabled and before rebooting, so the state of
1079  * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
1080  * leftovers during boot.
1081  */
1082 void clear_local_APIC(void)
1083 {
1084 	int maxlvt;
1085 	u32 v;
1086 
1087 	/* APIC hasn't been mapped yet */
1088 	if (!x2apic_mode && !apic_phys)
1089 		return;
1090 
1091 	maxlvt = lapic_get_maxlvt();
1092 	/*
1093 	 * Masking an LVT entry can trigger a local APIC error
1094 	 * if the vector is zero. Mask LVTERR first to prevent this.
1095 	 */
1096 	if (maxlvt >= 3) {
1097 		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
1098 		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
1099 	}
1100 	/*
1101 	 * Careful: we have to set masks only first to deassert
1102 	 * any level-triggered sources.
1103 	 */
1104 	v = apic_read(APIC_LVTT);
1105 	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
1106 	v = apic_read(APIC_LVT0);
1107 	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
1108 	v = apic_read(APIC_LVT1);
1109 	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
1110 	if (maxlvt >= 4) {
1111 		v = apic_read(APIC_LVTPC);
1112 		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
1113 	}
1114 
1115 	/* lets not touch this if we didn't frob it */
1116 #ifdef CONFIG_X86_THERMAL_VECTOR
1117 	if (maxlvt >= 5) {
1118 		v = apic_read(APIC_LVTTHMR);
1119 		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
1120 	}
1121 #endif
1122 #ifdef CONFIG_X86_MCE_INTEL
1123 	if (maxlvt >= 6) {
1124 		v = apic_read(APIC_LVTCMCI);
1125 		if (!(v & APIC_LVT_MASKED))
1126 			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
1127 	}
1128 #endif
1129 
1130 	/*
1131 	 * Clean APIC state for other OSs:
1132 	 */
1133 	apic_write(APIC_LVTT, APIC_LVT_MASKED);
1134 	apic_write(APIC_LVT0, APIC_LVT_MASKED);
1135 	apic_write(APIC_LVT1, APIC_LVT_MASKED);
1136 	if (maxlvt >= 3)
1137 		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
1138 	if (maxlvt >= 4)
1139 		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
1140 
1141 	/* Integrated APIC (!82489DX) ? */
1142 	if (lapic_is_integrated()) {
1143 		if (maxlvt > 3)
1144 			/* Clear ESR due to Pentium errata 3AP and 11AP */
1145 			apic_write(APIC_ESR, 0);
1146 		apic_read(APIC_ESR);
1147 	}
1148 }
1149 
1150 /**
1151  * disable_local_APIC - clear and disable the local APIC
1152  */
1153 void disable_local_APIC(void)
1154 {
1155 	unsigned int value;
1156 
1157 	/* APIC hasn't been mapped yet */
1158 	if (!x2apic_mode && !apic_phys)
1159 		return;
1160 
1161 	clear_local_APIC();
1162 
1163 	/*
1164 	 * Disable APIC (implies clearing of registers
1165 	 * for 82489DX!).
1166 	 */
1167 	value = apic_read(APIC_SPIV);
1168 	value &= ~APIC_SPIV_APIC_ENABLED;
1169 	apic_write(APIC_SPIV, value);
1170 
1171 #ifdef CONFIG_X86_32
1172 	/*
1173 	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
1174 	 * restore the disabled state.
1175 	 */
1176 	if (enabled_via_apicbase) {
1177 		unsigned int l, h;
1178 
1179 		rdmsr(MSR_IA32_APICBASE, l, h);
1180 		l &= ~MSR_IA32_APICBASE_ENABLE;
1181 		wrmsr(MSR_IA32_APICBASE, l, h);
1182 	}
1183 #endif
1184 }
1185 
1186 /*
1187  * If Linux enabled the LAPIC against the BIOS default disable it down before
1188  * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
1189  * not power-off.  Additionally clear all LVT entries before disable_local_APIC
1190  * for the case where Linux didn't enable the LAPIC.
1191  */
1192 void lapic_shutdown(void)
1193 {
1194 	unsigned long flags;
1195 
1196 	if (!boot_cpu_has(X86_FEATURE_APIC) && !apic_from_smp_config())
1197 		return;
1198 
1199 	local_irq_save(flags);
1200 
1201 #ifdef CONFIG_X86_32
1202 	if (!enabled_via_apicbase)
1203 		clear_local_APIC();
1204 	else
1205 #endif
1206 		disable_local_APIC();
1207 
1208 
1209 	local_irq_restore(flags);
1210 }
1211 
1212 /**
1213  * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1214  */
1215 void __init sync_Arb_IDs(void)
1216 {
1217 	/*
1218 	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1219 	 * needed on AMD.
1220 	 */
1221 	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1222 		return;
1223 
1224 	/*
1225 	 * Wait for idle.
1226 	 */
1227 	apic_wait_icr_idle();
1228 
1229 	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1230 	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1231 			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1232 }
1233 
1234 enum apic_intr_mode_id apic_intr_mode;
1235 
1236 static int __init apic_intr_mode_select(void)
1237 {
1238 	/* Check kernel option */
1239 	if (disable_apic) {
1240 		pr_info("APIC disabled via kernel command line\n");
1241 		return APIC_PIC;
1242 	}
1243 
1244 	/* Check BIOS */
1245 #ifdef CONFIG_X86_64
1246 	/* On 64-bit, the APIC must be integrated, Check local APIC only */
1247 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1248 		disable_apic = 1;
1249 		pr_info("APIC disabled by BIOS\n");
1250 		return APIC_PIC;
1251 	}
1252 #else
1253 	/* On 32-bit, the APIC may be integrated APIC or 82489DX */
1254 
1255 	/* Neither 82489DX nor integrated APIC ? */
1256 	if (!boot_cpu_has(X86_FEATURE_APIC) && !smp_found_config) {
1257 		disable_apic = 1;
1258 		return APIC_PIC;
1259 	}
1260 
1261 	/* If the BIOS pretends there is an integrated APIC ? */
1262 	if (!boot_cpu_has(X86_FEATURE_APIC) &&
1263 		APIC_INTEGRATED(boot_cpu_apic_version)) {
1264 		disable_apic = 1;
1265 		pr_err(FW_BUG "Local APIC %d not detected, force emulation\n",
1266 				       boot_cpu_physical_apicid);
1267 		return APIC_PIC;
1268 	}
1269 #endif
1270 
1271 	/* Check MP table or ACPI MADT configuration */
1272 	if (!smp_found_config) {
1273 		disable_ioapic_support();
1274 		if (!acpi_lapic) {
1275 			pr_info("APIC: ACPI MADT or MP tables are not detected\n");
1276 			return APIC_VIRTUAL_WIRE_NO_CONFIG;
1277 		}
1278 		return APIC_VIRTUAL_WIRE;
1279 	}
1280 
1281 #ifdef CONFIG_SMP
1282 	/* If SMP should be disabled, then really disable it! */
1283 	if (!setup_max_cpus) {
1284 		pr_info("APIC: SMP mode deactivated\n");
1285 		return APIC_SYMMETRIC_IO_NO_ROUTING;
1286 	}
1287 
1288 	if (read_apic_id() != boot_cpu_physical_apicid) {
1289 		panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
1290 		     read_apic_id(), boot_cpu_physical_apicid);
1291 		/* Or can we switch back to PIC here? */
1292 	}
1293 #endif
1294 
1295 	return APIC_SYMMETRIC_IO;
1296 }
1297 
1298 /*
1299  * An initial setup of the virtual wire mode.
1300  */
1301 void __init init_bsp_APIC(void)
1302 {
1303 	unsigned int value;
1304 
1305 	/*
1306 	 * Don't do the setup now if we have a SMP BIOS as the
1307 	 * through-I/O-APIC virtual wire mode might be active.
1308 	 */
1309 	if (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC))
1310 		return;
1311 
1312 	/*
1313 	 * Do not trust the local APIC being empty at bootup.
1314 	 */
1315 	clear_local_APIC();
1316 
1317 	/*
1318 	 * Enable APIC.
1319 	 */
1320 	value = apic_read(APIC_SPIV);
1321 	value &= ~APIC_VECTOR_MASK;
1322 	value |= APIC_SPIV_APIC_ENABLED;
1323 
1324 #ifdef CONFIG_X86_32
1325 	/* This bit is reserved on P4/Xeon and should be cleared */
1326 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1327 	    (boot_cpu_data.x86 == 15))
1328 		value &= ~APIC_SPIV_FOCUS_DISABLED;
1329 	else
1330 #endif
1331 		value |= APIC_SPIV_FOCUS_DISABLED;
1332 	value |= SPURIOUS_APIC_VECTOR;
1333 	apic_write(APIC_SPIV, value);
1334 
1335 	/*
1336 	 * Set up the virtual wire mode.
1337 	 */
1338 	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1339 	value = APIC_DM_NMI;
1340 	if (!lapic_is_integrated())		/* 82489DX */
1341 		value |= APIC_LVT_LEVEL_TRIGGER;
1342 	if (apic_extnmi == APIC_EXTNMI_NONE)
1343 		value |= APIC_LVT_MASKED;
1344 	apic_write(APIC_LVT1, value);
1345 }
1346 
1347 /* Init the interrupt delivery mode for the BSP */
1348 void __init apic_intr_mode_init(void)
1349 {
1350 	bool upmode = IS_ENABLED(CONFIG_UP_LATE_INIT);
1351 
1352 	apic_intr_mode = apic_intr_mode_select();
1353 
1354 	switch (apic_intr_mode) {
1355 	case APIC_PIC:
1356 		pr_info("APIC: Keep in PIC mode(8259)\n");
1357 		return;
1358 	case APIC_VIRTUAL_WIRE:
1359 		pr_info("APIC: Switch to virtual wire mode setup\n");
1360 		default_setup_apic_routing();
1361 		break;
1362 	case APIC_VIRTUAL_WIRE_NO_CONFIG:
1363 		pr_info("APIC: Switch to virtual wire mode setup with no configuration\n");
1364 		upmode = true;
1365 		default_setup_apic_routing();
1366 		break;
1367 	case APIC_SYMMETRIC_IO:
1368 		pr_info("APIC: Switch to symmetric I/O mode setup\n");
1369 		default_setup_apic_routing();
1370 		break;
1371 	case APIC_SYMMETRIC_IO_NO_ROUTING:
1372 		pr_info("APIC: Switch to symmetric I/O mode setup in no SMP routine\n");
1373 		break;
1374 	}
1375 
1376 	apic_bsp_setup(upmode);
1377 }
1378 
1379 static void lapic_setup_esr(void)
1380 {
1381 	unsigned int oldvalue, value, maxlvt;
1382 
1383 	if (!lapic_is_integrated()) {
1384 		pr_info("No ESR for 82489DX.\n");
1385 		return;
1386 	}
1387 
1388 	if (apic->disable_esr) {
1389 		/*
1390 		 * Something untraceable is creating bad interrupts on
1391 		 * secondary quads ... for the moment, just leave the
1392 		 * ESR disabled - we can't do anything useful with the
1393 		 * errors anyway - mbligh
1394 		 */
1395 		pr_info("Leaving ESR disabled.\n");
1396 		return;
1397 	}
1398 
1399 	maxlvt = lapic_get_maxlvt();
1400 	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1401 		apic_write(APIC_ESR, 0);
1402 	oldvalue = apic_read(APIC_ESR);
1403 
1404 	/* enables sending errors */
1405 	value = ERROR_APIC_VECTOR;
1406 	apic_write(APIC_LVTERR, value);
1407 
1408 	/*
1409 	 * spec says clear errors after enabling vector.
1410 	 */
1411 	if (maxlvt > 3)
1412 		apic_write(APIC_ESR, 0);
1413 	value = apic_read(APIC_ESR);
1414 	if (value != oldvalue)
1415 		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1416 			"vector: 0x%08x  after: 0x%08x\n",
1417 			oldvalue, value);
1418 }
1419 
1420 static void apic_pending_intr_clear(void)
1421 {
1422 	long long max_loops = cpu_khz ? cpu_khz : 1000000;
1423 	unsigned long long tsc = 0, ntsc;
1424 	unsigned int queued;
1425 	unsigned long value;
1426 	int i, j, acked = 0;
1427 
1428 	if (boot_cpu_has(X86_FEATURE_TSC))
1429 		tsc = rdtsc();
1430 	/*
1431 	 * After a crash, we no longer service the interrupts and a pending
1432 	 * interrupt from previous kernel might still have ISR bit set.
1433 	 *
1434 	 * Most probably by now CPU has serviced that pending interrupt and
1435 	 * it might not have done the ack_APIC_irq() because it thought,
1436 	 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1437 	 * does not clear the ISR bit and cpu thinks it has already serivced
1438 	 * the interrupt. Hence a vector might get locked. It was noticed
1439 	 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1440 	 */
1441 	do {
1442 		queued = 0;
1443 		for (i = APIC_ISR_NR - 1; i >= 0; i--)
1444 			queued |= apic_read(APIC_IRR + i*0x10);
1445 
1446 		for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1447 			value = apic_read(APIC_ISR + i*0x10);
1448 			for_each_set_bit(j, &value, 32) {
1449 				ack_APIC_irq();
1450 				acked++;
1451 			}
1452 		}
1453 		if (acked > 256) {
1454 			pr_err("LAPIC pending interrupts after %d EOI\n", acked);
1455 			break;
1456 		}
1457 		if (queued) {
1458 			if (boot_cpu_has(X86_FEATURE_TSC) && cpu_khz) {
1459 				ntsc = rdtsc();
1460 				max_loops = (cpu_khz << 10) - (ntsc - tsc);
1461 			} else {
1462 				max_loops--;
1463 			}
1464 		}
1465 	} while (queued && max_loops > 0);
1466 	WARN_ON(max_loops <= 0);
1467 }
1468 
1469 /**
1470  * setup_local_APIC - setup the local APIC
1471  *
1472  * Used to setup local APIC while initializing BSP or bringing up APs.
1473  * Always called with preemption disabled.
1474  */
1475 static void setup_local_APIC(void)
1476 {
1477 	int cpu = smp_processor_id();
1478 	unsigned int value;
1479 #ifdef CONFIG_X86_32
1480 	int logical_apicid, ldr_apicid;
1481 #endif
1482 
1483 
1484 	if (disable_apic) {
1485 		disable_ioapic_support();
1486 		return;
1487 	}
1488 
1489 #ifdef CONFIG_X86_32
1490 	/* Pound the ESR really hard over the head with a big hammer - mbligh */
1491 	if (lapic_is_integrated() && apic->disable_esr) {
1492 		apic_write(APIC_ESR, 0);
1493 		apic_write(APIC_ESR, 0);
1494 		apic_write(APIC_ESR, 0);
1495 		apic_write(APIC_ESR, 0);
1496 	}
1497 #endif
1498 	perf_events_lapic_init();
1499 
1500 	/*
1501 	 * Double-check whether this APIC is really registered.
1502 	 * This is meaningless in clustered apic mode, so we skip it.
1503 	 */
1504 	BUG_ON(!apic->apic_id_registered());
1505 
1506 	/*
1507 	 * Intel recommends to set DFR, LDR and TPR before enabling
1508 	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
1509 	 * document number 292116).  So here it goes...
1510 	 */
1511 	apic->init_apic_ldr();
1512 
1513 #ifdef CONFIG_X86_32
1514 	/*
1515 	 * APIC LDR is initialized.  If logical_apicid mapping was
1516 	 * initialized during get_smp_config(), make sure it matches the
1517 	 * actual value.
1518 	 */
1519 	logical_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
1520 	ldr_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
1521 	WARN_ON(logical_apicid != BAD_APICID && logical_apicid != ldr_apicid);
1522 	/* always use the value from LDR */
1523 	early_per_cpu(x86_cpu_to_logical_apicid, cpu) = ldr_apicid;
1524 #endif
1525 
1526 	/*
1527 	 * Set Task Priority to 'accept all'. We never change this
1528 	 * later on.
1529 	 */
1530 	value = apic_read(APIC_TASKPRI);
1531 	value &= ~APIC_TPRI_MASK;
1532 	apic_write(APIC_TASKPRI, value);
1533 
1534 	apic_pending_intr_clear();
1535 
1536 	/*
1537 	 * Now that we are all set up, enable the APIC
1538 	 */
1539 	value = apic_read(APIC_SPIV);
1540 	value &= ~APIC_VECTOR_MASK;
1541 	/*
1542 	 * Enable APIC
1543 	 */
1544 	value |= APIC_SPIV_APIC_ENABLED;
1545 
1546 #ifdef CONFIG_X86_32
1547 	/*
1548 	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1549 	 * certain networking cards. If high frequency interrupts are
1550 	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1551 	 * entry is masked/unmasked at a high rate as well then sooner or
1552 	 * later IOAPIC line gets 'stuck', no more interrupts are received
1553 	 * from the device. If focus CPU is disabled then the hang goes
1554 	 * away, oh well :-(
1555 	 *
1556 	 * [ This bug can be reproduced easily with a level-triggered
1557 	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1558 	 *   BX chipset. ]
1559 	 */
1560 	/*
1561 	 * Actually disabling the focus CPU check just makes the hang less
1562 	 * frequent as it makes the interrupt distributon model be more
1563 	 * like LRU than MRU (the short-term load is more even across CPUs).
1564 	 */
1565 
1566 	/*
1567 	 * - enable focus processor (bit==0)
1568 	 * - 64bit mode always use processor focus
1569 	 *   so no need to set it
1570 	 */
1571 	value &= ~APIC_SPIV_FOCUS_DISABLED;
1572 #endif
1573 
1574 	/*
1575 	 * Set spurious IRQ vector
1576 	 */
1577 	value |= SPURIOUS_APIC_VECTOR;
1578 	apic_write(APIC_SPIV, value);
1579 
1580 	/*
1581 	 * Set up LVT0, LVT1:
1582 	 *
1583 	 * set up through-local-APIC on the boot CPU's LINT0. This is not
1584 	 * strictly necessary in pure symmetric-IO mode, but sometimes
1585 	 * we delegate interrupts to the 8259A.
1586 	 */
1587 	/*
1588 	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1589 	 */
1590 	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1591 	if (!cpu && (pic_mode || !value || skip_ioapic_setup)) {
1592 		value = APIC_DM_EXTINT;
1593 		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
1594 	} else {
1595 		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1596 		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
1597 	}
1598 	apic_write(APIC_LVT0, value);
1599 
1600 	/*
1601 	 * Only the BSP sees the LINT1 NMI signal by default. This can be
1602 	 * modified by apic_extnmi= boot option.
1603 	 */
1604 	if ((!cpu && apic_extnmi != APIC_EXTNMI_NONE) ||
1605 	    apic_extnmi == APIC_EXTNMI_ALL)
1606 		value = APIC_DM_NMI;
1607 	else
1608 		value = APIC_DM_NMI | APIC_LVT_MASKED;
1609 
1610 	/* Is 82489DX ? */
1611 	if (!lapic_is_integrated())
1612 		value |= APIC_LVT_LEVEL_TRIGGER;
1613 	apic_write(APIC_LVT1, value);
1614 
1615 #ifdef CONFIG_X86_MCE_INTEL
1616 	/* Recheck CMCI information after local APIC is up on CPU #0 */
1617 	if (!cpu)
1618 		cmci_recheck();
1619 #endif
1620 }
1621 
1622 static void end_local_APIC_setup(void)
1623 {
1624 	lapic_setup_esr();
1625 
1626 #ifdef CONFIG_X86_32
1627 	{
1628 		unsigned int value;
1629 		/* Disable the local apic timer */
1630 		value = apic_read(APIC_LVTT);
1631 		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1632 		apic_write(APIC_LVTT, value);
1633 	}
1634 #endif
1635 
1636 	apic_pm_activate();
1637 }
1638 
1639 /*
1640  * APIC setup function for application processors. Called from smpboot.c
1641  */
1642 void apic_ap_setup(void)
1643 {
1644 	setup_local_APIC();
1645 	end_local_APIC_setup();
1646 }
1647 
1648 #ifdef CONFIG_X86_X2APIC
1649 int x2apic_mode;
1650 
1651 enum {
1652 	X2APIC_OFF,
1653 	X2APIC_ON,
1654 	X2APIC_DISABLED,
1655 };
1656 static int x2apic_state;
1657 
1658 static void __x2apic_disable(void)
1659 {
1660 	u64 msr;
1661 
1662 	if (!boot_cpu_has(X86_FEATURE_APIC))
1663 		return;
1664 
1665 	rdmsrl(MSR_IA32_APICBASE, msr);
1666 	if (!(msr & X2APIC_ENABLE))
1667 		return;
1668 	/* Disable xapic and x2apic first and then reenable xapic mode */
1669 	wrmsrl(MSR_IA32_APICBASE, msr & ~(X2APIC_ENABLE | XAPIC_ENABLE));
1670 	wrmsrl(MSR_IA32_APICBASE, msr & ~X2APIC_ENABLE);
1671 	printk_once(KERN_INFO "x2apic disabled\n");
1672 }
1673 
1674 static void __x2apic_enable(void)
1675 {
1676 	u64 msr;
1677 
1678 	rdmsrl(MSR_IA32_APICBASE, msr);
1679 	if (msr & X2APIC_ENABLE)
1680 		return;
1681 	wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE);
1682 	printk_once(KERN_INFO "x2apic enabled\n");
1683 }
1684 
1685 static int __init setup_nox2apic(char *str)
1686 {
1687 	if (x2apic_enabled()) {
1688 		int apicid = native_apic_msr_read(APIC_ID);
1689 
1690 		if (apicid >= 255) {
1691 			pr_warning("Apicid: %08x, cannot enforce nox2apic\n",
1692 				   apicid);
1693 			return 0;
1694 		}
1695 		pr_warning("x2apic already enabled.\n");
1696 		__x2apic_disable();
1697 	}
1698 	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
1699 	x2apic_state = X2APIC_DISABLED;
1700 	x2apic_mode = 0;
1701 	return 0;
1702 }
1703 early_param("nox2apic", setup_nox2apic);
1704 
1705 /* Called from cpu_init() to enable x2apic on (secondary) cpus */
1706 void x2apic_setup(void)
1707 {
1708 	/*
1709 	 * If x2apic is not in ON state, disable it if already enabled
1710 	 * from BIOS.
1711 	 */
1712 	if (x2apic_state != X2APIC_ON) {
1713 		__x2apic_disable();
1714 		return;
1715 	}
1716 	__x2apic_enable();
1717 }
1718 
1719 static __init void x2apic_disable(void)
1720 {
1721 	u32 x2apic_id, state = x2apic_state;
1722 
1723 	x2apic_mode = 0;
1724 	x2apic_state = X2APIC_DISABLED;
1725 
1726 	if (state != X2APIC_ON)
1727 		return;
1728 
1729 	x2apic_id = read_apic_id();
1730 	if (x2apic_id >= 255)
1731 		panic("Cannot disable x2apic, id: %08x\n", x2apic_id);
1732 
1733 	__x2apic_disable();
1734 	register_lapic_address(mp_lapic_addr);
1735 }
1736 
1737 static __init void x2apic_enable(void)
1738 {
1739 	if (x2apic_state != X2APIC_OFF)
1740 		return;
1741 
1742 	x2apic_mode = 1;
1743 	x2apic_state = X2APIC_ON;
1744 	__x2apic_enable();
1745 }
1746 
1747 static __init void try_to_enable_x2apic(int remap_mode)
1748 {
1749 	if (x2apic_state == X2APIC_DISABLED)
1750 		return;
1751 
1752 	if (remap_mode != IRQ_REMAP_X2APIC_MODE) {
1753 		/* IR is required if there is APIC ID > 255 even when running
1754 		 * under KVM
1755 		 */
1756 		if (max_physical_apicid > 255 ||
1757 		    !x86_init.hyper.x2apic_available()) {
1758 			pr_info("x2apic: IRQ remapping doesn't support X2APIC mode\n");
1759 			x2apic_disable();
1760 			return;
1761 		}
1762 
1763 		/*
1764 		 * without IR all CPUs can be addressed by IOAPIC/MSI
1765 		 * only in physical mode
1766 		 */
1767 		x2apic_phys = 1;
1768 	}
1769 	x2apic_enable();
1770 }
1771 
1772 void __init check_x2apic(void)
1773 {
1774 	if (x2apic_enabled()) {
1775 		pr_info("x2apic: enabled by BIOS, switching to x2apic ops\n");
1776 		x2apic_mode = 1;
1777 		x2apic_state = X2APIC_ON;
1778 	} else if (!boot_cpu_has(X86_FEATURE_X2APIC)) {
1779 		x2apic_state = X2APIC_DISABLED;
1780 	}
1781 }
1782 #else /* CONFIG_X86_X2APIC */
1783 static int __init validate_x2apic(void)
1784 {
1785 	if (!apic_is_x2apic_enabled())
1786 		return 0;
1787 	/*
1788 	 * Checkme: Can we simply turn off x2apic here instead of panic?
1789 	 */
1790 	panic("BIOS has enabled x2apic but kernel doesn't support x2apic, please disable x2apic in BIOS.\n");
1791 }
1792 early_initcall(validate_x2apic);
1793 
1794 static inline void try_to_enable_x2apic(int remap_mode) { }
1795 static inline void __x2apic_enable(void) { }
1796 #endif /* !CONFIG_X86_X2APIC */
1797 
1798 void __init enable_IR_x2apic(void)
1799 {
1800 	unsigned long flags;
1801 	int ret, ir_stat;
1802 
1803 	if (skip_ioapic_setup) {
1804 		pr_info("Not enabling interrupt remapping due to skipped IO-APIC setup\n");
1805 		return;
1806 	}
1807 
1808 	ir_stat = irq_remapping_prepare();
1809 	if (ir_stat < 0 && !x2apic_supported())
1810 		return;
1811 
1812 	ret = save_ioapic_entries();
1813 	if (ret) {
1814 		pr_info("Saving IO-APIC state failed: %d\n", ret);
1815 		return;
1816 	}
1817 
1818 	local_irq_save(flags);
1819 	legacy_pic->mask_all();
1820 	mask_ioapic_entries();
1821 
1822 	/* If irq_remapping_prepare() succeeded, try to enable it */
1823 	if (ir_stat >= 0)
1824 		ir_stat = irq_remapping_enable();
1825 	/* ir_stat contains the remap mode or an error code */
1826 	try_to_enable_x2apic(ir_stat);
1827 
1828 	if (ir_stat < 0)
1829 		restore_ioapic_entries();
1830 	legacy_pic->restore_mask();
1831 	local_irq_restore(flags);
1832 }
1833 
1834 #ifdef CONFIG_X86_64
1835 /*
1836  * Detect and enable local APICs on non-SMP boards.
1837  * Original code written by Keir Fraser.
1838  * On AMD64 we trust the BIOS - if it says no APIC it is likely
1839  * not correctly set up (usually the APIC timer won't work etc.)
1840  */
1841 static int __init detect_init_APIC(void)
1842 {
1843 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1844 		pr_info("No local APIC present\n");
1845 		return -1;
1846 	}
1847 
1848 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1849 	return 0;
1850 }
1851 #else
1852 
1853 static int __init apic_verify(void)
1854 {
1855 	u32 features, h, l;
1856 
1857 	/*
1858 	 * The APIC feature bit should now be enabled
1859 	 * in `cpuid'
1860 	 */
1861 	features = cpuid_edx(1);
1862 	if (!(features & (1 << X86_FEATURE_APIC))) {
1863 		pr_warning("Could not enable APIC!\n");
1864 		return -1;
1865 	}
1866 	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1867 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1868 
1869 	/* The BIOS may have set up the APIC at some other address */
1870 	if (boot_cpu_data.x86 >= 6) {
1871 		rdmsr(MSR_IA32_APICBASE, l, h);
1872 		if (l & MSR_IA32_APICBASE_ENABLE)
1873 			mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1874 	}
1875 
1876 	pr_info("Found and enabled local APIC!\n");
1877 	return 0;
1878 }
1879 
1880 int __init apic_force_enable(unsigned long addr)
1881 {
1882 	u32 h, l;
1883 
1884 	if (disable_apic)
1885 		return -1;
1886 
1887 	/*
1888 	 * Some BIOSes disable the local APIC in the APIC_BASE
1889 	 * MSR. This can only be done in software for Intel P6 or later
1890 	 * and AMD K7 (Model > 1) or later.
1891 	 */
1892 	if (boot_cpu_data.x86 >= 6) {
1893 		rdmsr(MSR_IA32_APICBASE, l, h);
1894 		if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1895 			pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1896 			l &= ~MSR_IA32_APICBASE_BASE;
1897 			l |= MSR_IA32_APICBASE_ENABLE | addr;
1898 			wrmsr(MSR_IA32_APICBASE, l, h);
1899 			enabled_via_apicbase = 1;
1900 		}
1901 	}
1902 	return apic_verify();
1903 }
1904 
1905 /*
1906  * Detect and initialize APIC
1907  */
1908 static int __init detect_init_APIC(void)
1909 {
1910 	/* Disabled by kernel option? */
1911 	if (disable_apic)
1912 		return -1;
1913 
1914 	switch (boot_cpu_data.x86_vendor) {
1915 	case X86_VENDOR_AMD:
1916 		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1917 		    (boot_cpu_data.x86 >= 15))
1918 			break;
1919 		goto no_apic;
1920 	case X86_VENDOR_HYGON:
1921 		break;
1922 	case X86_VENDOR_INTEL:
1923 		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1924 		    (boot_cpu_data.x86 == 5 && boot_cpu_has(X86_FEATURE_APIC)))
1925 			break;
1926 		goto no_apic;
1927 	default:
1928 		goto no_apic;
1929 	}
1930 
1931 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1932 		/*
1933 		 * Over-ride BIOS and try to enable the local APIC only if
1934 		 * "lapic" specified.
1935 		 */
1936 		if (!force_enable_local_apic) {
1937 			pr_info("Local APIC disabled by BIOS -- "
1938 				"you can enable it with \"lapic\"\n");
1939 			return -1;
1940 		}
1941 		if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
1942 			return -1;
1943 	} else {
1944 		if (apic_verify())
1945 			return -1;
1946 	}
1947 
1948 	apic_pm_activate();
1949 
1950 	return 0;
1951 
1952 no_apic:
1953 	pr_info("No local APIC present or hardware disabled\n");
1954 	return -1;
1955 }
1956 #endif
1957 
1958 /**
1959  * init_apic_mappings - initialize APIC mappings
1960  */
1961 void __init init_apic_mappings(void)
1962 {
1963 	unsigned int new_apicid;
1964 
1965 	apic_check_deadline_errata();
1966 
1967 	if (x2apic_mode) {
1968 		boot_cpu_physical_apicid = read_apic_id();
1969 		return;
1970 	}
1971 
1972 	/* If no local APIC can be found return early */
1973 	if (!smp_found_config && detect_init_APIC()) {
1974 		/* lets NOP'ify apic operations */
1975 		pr_info("APIC: disable apic facility\n");
1976 		apic_disable();
1977 	} else {
1978 		apic_phys = mp_lapic_addr;
1979 
1980 		/*
1981 		 * If the system has ACPI MADT tables or MP info, the LAPIC
1982 		 * address is already registered.
1983 		 */
1984 		if (!acpi_lapic && !smp_found_config)
1985 			register_lapic_address(apic_phys);
1986 	}
1987 
1988 	/*
1989 	 * Fetch the APIC ID of the BSP in case we have a
1990 	 * default configuration (or the MP table is broken).
1991 	 */
1992 	new_apicid = read_apic_id();
1993 	if (boot_cpu_physical_apicid != new_apicid) {
1994 		boot_cpu_physical_apicid = new_apicid;
1995 		/*
1996 		 * yeah -- we lie about apic_version
1997 		 * in case if apic was disabled via boot option
1998 		 * but it's not a problem for SMP compiled kernel
1999 		 * since apic_intr_mode_select is prepared for such
2000 		 * a case and disable smp mode
2001 		 */
2002 		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
2003 	}
2004 }
2005 
2006 void __init register_lapic_address(unsigned long address)
2007 {
2008 	mp_lapic_addr = address;
2009 
2010 	if (!x2apic_mode) {
2011 		set_fixmap_nocache(FIX_APIC_BASE, address);
2012 		apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
2013 			    APIC_BASE, address);
2014 	}
2015 	if (boot_cpu_physical_apicid == -1U) {
2016 		boot_cpu_physical_apicid  = read_apic_id();
2017 		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
2018 	}
2019 }
2020 
2021 /*
2022  * Local APIC interrupts
2023  */
2024 
2025 /*
2026  * This interrupt should _never_ happen with our APIC/SMP architecture
2027  */
2028 __visible void __irq_entry smp_spurious_interrupt(struct pt_regs *regs)
2029 {
2030 	u8 vector = ~regs->orig_ax;
2031 	u32 v;
2032 
2033 	entering_irq();
2034 	trace_spurious_apic_entry(vector);
2035 
2036 	/*
2037 	 * Check if this really is a spurious interrupt and ACK it
2038 	 * if it is a vectored one.  Just in case...
2039 	 * Spurious interrupts should not be ACKed.
2040 	 */
2041 	v = apic_read(APIC_ISR + ((vector & ~0x1f) >> 1));
2042 	if (v & (1 << (vector & 0x1f)))
2043 		ack_APIC_irq();
2044 
2045 	inc_irq_stat(irq_spurious_count);
2046 
2047 	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
2048 	pr_info("spurious APIC interrupt through vector %02x on CPU#%d, "
2049 		"should never happen.\n", vector, smp_processor_id());
2050 
2051 	trace_spurious_apic_exit(vector);
2052 	exiting_irq();
2053 }
2054 
2055 /*
2056  * This interrupt should never happen with our APIC/SMP architecture
2057  */
2058 __visible void __irq_entry smp_error_interrupt(struct pt_regs *regs)
2059 {
2060 	static const char * const error_interrupt_reason[] = {
2061 		"Send CS error",		/* APIC Error Bit 0 */
2062 		"Receive CS error",		/* APIC Error Bit 1 */
2063 		"Send accept error",		/* APIC Error Bit 2 */
2064 		"Receive accept error",		/* APIC Error Bit 3 */
2065 		"Redirectable IPI",		/* APIC Error Bit 4 */
2066 		"Send illegal vector",		/* APIC Error Bit 5 */
2067 		"Received illegal vector",	/* APIC Error Bit 6 */
2068 		"Illegal register address",	/* APIC Error Bit 7 */
2069 	};
2070 	u32 v, i = 0;
2071 
2072 	entering_irq();
2073 	trace_error_apic_entry(ERROR_APIC_VECTOR);
2074 
2075 	/* First tickle the hardware, only then report what went on. -- REW */
2076 	if (lapic_get_maxlvt() > 3)	/* Due to the Pentium erratum 3AP. */
2077 		apic_write(APIC_ESR, 0);
2078 	v = apic_read(APIC_ESR);
2079 	ack_APIC_irq();
2080 	atomic_inc(&irq_err_count);
2081 
2082 	apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x",
2083 		    smp_processor_id(), v);
2084 
2085 	v &= 0xff;
2086 	while (v) {
2087 		if (v & 0x1)
2088 			apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
2089 		i++;
2090 		v >>= 1;
2091 	}
2092 
2093 	apic_printk(APIC_DEBUG, KERN_CONT "\n");
2094 
2095 	trace_error_apic_exit(ERROR_APIC_VECTOR);
2096 	exiting_irq();
2097 }
2098 
2099 /**
2100  * connect_bsp_APIC - attach the APIC to the interrupt system
2101  */
2102 static void __init connect_bsp_APIC(void)
2103 {
2104 #ifdef CONFIG_X86_32
2105 	if (pic_mode) {
2106 		/*
2107 		 * Do not trust the local APIC being empty at bootup.
2108 		 */
2109 		clear_local_APIC();
2110 		/*
2111 		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
2112 		 * local APIC to INT and NMI lines.
2113 		 */
2114 		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
2115 				"enabling APIC mode.\n");
2116 		imcr_pic_to_apic();
2117 	}
2118 #endif
2119 }
2120 
2121 /**
2122  * disconnect_bsp_APIC - detach the APIC from the interrupt system
2123  * @virt_wire_setup:	indicates, whether virtual wire mode is selected
2124  *
2125  * Virtual wire mode is necessary to deliver legacy interrupts even when the
2126  * APIC is disabled.
2127  */
2128 void disconnect_bsp_APIC(int virt_wire_setup)
2129 {
2130 	unsigned int value;
2131 
2132 #ifdef CONFIG_X86_32
2133 	if (pic_mode) {
2134 		/*
2135 		 * Put the board back into PIC mode (has an effect only on
2136 		 * certain older boards).  Note that APIC interrupts, including
2137 		 * IPIs, won't work beyond this point!  The only exception are
2138 		 * INIT IPIs.
2139 		 */
2140 		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
2141 				"entering PIC mode.\n");
2142 		imcr_apic_to_pic();
2143 		return;
2144 	}
2145 #endif
2146 
2147 	/* Go back to Virtual Wire compatibility mode */
2148 
2149 	/* For the spurious interrupt use vector F, and enable it */
2150 	value = apic_read(APIC_SPIV);
2151 	value &= ~APIC_VECTOR_MASK;
2152 	value |= APIC_SPIV_APIC_ENABLED;
2153 	value |= 0xf;
2154 	apic_write(APIC_SPIV, value);
2155 
2156 	if (!virt_wire_setup) {
2157 		/*
2158 		 * For LVT0 make it edge triggered, active high,
2159 		 * external and enabled
2160 		 */
2161 		value = apic_read(APIC_LVT0);
2162 		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2163 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2164 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2165 		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2166 		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
2167 		apic_write(APIC_LVT0, value);
2168 	} else {
2169 		/* Disable LVT0 */
2170 		apic_write(APIC_LVT0, APIC_LVT_MASKED);
2171 	}
2172 
2173 	/*
2174 	 * For LVT1 make it edge triggered, active high,
2175 	 * nmi and enabled
2176 	 */
2177 	value = apic_read(APIC_LVT1);
2178 	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2179 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2180 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2181 	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2182 	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
2183 	apic_write(APIC_LVT1, value);
2184 }
2185 
2186 /*
2187  * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
2188  * contiguously, it equals to current allocated max logical CPU ID plus 1.
2189  * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
2190  * so the maximum of nr_logical_cpuids is nr_cpu_ids.
2191  *
2192  * NOTE: Reserve 0 for BSP.
2193  */
2194 static int nr_logical_cpuids = 1;
2195 
2196 /*
2197  * Used to store mapping between logical CPU IDs and APIC IDs.
2198  */
2199 static int cpuid_to_apicid[] = {
2200 	[0 ... NR_CPUS - 1] = -1,
2201 };
2202 
2203 #ifdef CONFIG_SMP
2204 /**
2205  * apic_id_is_primary_thread - Check whether APIC ID belongs to a primary thread
2206  * @id:	APIC ID to check
2207  */
2208 bool apic_id_is_primary_thread(unsigned int apicid)
2209 {
2210 	u32 mask;
2211 
2212 	if (smp_num_siblings == 1)
2213 		return true;
2214 	/* Isolate the SMT bit(s) in the APICID and check for 0 */
2215 	mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
2216 	return !(apicid & mask);
2217 }
2218 #endif
2219 
2220 /*
2221  * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
2222  * and cpuid_to_apicid[] synchronized.
2223  */
2224 static int allocate_logical_cpuid(int apicid)
2225 {
2226 	int i;
2227 
2228 	/*
2229 	 * cpuid <-> apicid mapping is persistent, so when a cpu is up,
2230 	 * check if the kernel has allocated a cpuid for it.
2231 	 */
2232 	for (i = 0; i < nr_logical_cpuids; i++) {
2233 		if (cpuid_to_apicid[i] == apicid)
2234 			return i;
2235 	}
2236 
2237 	/* Allocate a new cpuid. */
2238 	if (nr_logical_cpuids >= nr_cpu_ids) {
2239 		WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
2240 			     "Processor %d/0x%x and the rest are ignored.\n",
2241 			     nr_cpu_ids, nr_logical_cpuids, apicid);
2242 		return -EINVAL;
2243 	}
2244 
2245 	cpuid_to_apicid[nr_logical_cpuids] = apicid;
2246 	return nr_logical_cpuids++;
2247 }
2248 
2249 int generic_processor_info(int apicid, int version)
2250 {
2251 	int cpu, max = nr_cpu_ids;
2252 	bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
2253 				phys_cpu_present_map);
2254 
2255 	/*
2256 	 * boot_cpu_physical_apicid is designed to have the apicid
2257 	 * returned by read_apic_id(), i.e, the apicid of the
2258 	 * currently booting-up processor. However, on some platforms,
2259 	 * it is temporarily modified by the apicid reported as BSP
2260 	 * through MP table. Concretely:
2261 	 *
2262 	 * - arch/x86/kernel/mpparse.c: MP_processor_info()
2263 	 * - arch/x86/mm/amdtopology.c: amd_numa_init()
2264 	 *
2265 	 * This function is executed with the modified
2266 	 * boot_cpu_physical_apicid. So, disabled_cpu_apicid kernel
2267 	 * parameter doesn't work to disable APs on kdump 2nd kernel.
2268 	 *
2269 	 * Since fixing handling of boot_cpu_physical_apicid requires
2270 	 * another discussion and tests on each platform, we leave it
2271 	 * for now and here we use read_apic_id() directly in this
2272 	 * function, generic_processor_info().
2273 	 */
2274 	if (disabled_cpu_apicid != BAD_APICID &&
2275 	    disabled_cpu_apicid != read_apic_id() &&
2276 	    disabled_cpu_apicid == apicid) {
2277 		int thiscpu = num_processors + disabled_cpus;
2278 
2279 		pr_warning("APIC: Disabling requested cpu."
2280 			   " Processor %d/0x%x ignored.\n",
2281 			   thiscpu, apicid);
2282 
2283 		disabled_cpus++;
2284 		return -ENODEV;
2285 	}
2286 
2287 	/*
2288 	 * If boot cpu has not been detected yet, then only allow upto
2289 	 * nr_cpu_ids - 1 processors and keep one slot free for boot cpu
2290 	 */
2291 	if (!boot_cpu_detected && num_processors >= nr_cpu_ids - 1 &&
2292 	    apicid != boot_cpu_physical_apicid) {
2293 		int thiscpu = max + disabled_cpus - 1;
2294 
2295 		pr_warning(
2296 			"APIC: NR_CPUS/possible_cpus limit of %i almost"
2297 			" reached. Keeping one slot for boot cpu."
2298 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
2299 
2300 		disabled_cpus++;
2301 		return -ENODEV;
2302 	}
2303 
2304 	if (num_processors >= nr_cpu_ids) {
2305 		int thiscpu = max + disabled_cpus;
2306 
2307 		pr_warning("APIC: NR_CPUS/possible_cpus limit of %i "
2308 			   "reached. Processor %d/0x%x ignored.\n",
2309 			   max, thiscpu, apicid);
2310 
2311 		disabled_cpus++;
2312 		return -EINVAL;
2313 	}
2314 
2315 	if (apicid == boot_cpu_physical_apicid) {
2316 		/*
2317 		 * x86_bios_cpu_apicid is required to have processors listed
2318 		 * in same order as logical cpu numbers. Hence the first
2319 		 * entry is BSP, and so on.
2320 		 * boot_cpu_init() already hold bit 0 in cpu_present_mask
2321 		 * for BSP.
2322 		 */
2323 		cpu = 0;
2324 
2325 		/* Logical cpuid 0 is reserved for BSP. */
2326 		cpuid_to_apicid[0] = apicid;
2327 	} else {
2328 		cpu = allocate_logical_cpuid(apicid);
2329 		if (cpu < 0) {
2330 			disabled_cpus++;
2331 			return -EINVAL;
2332 		}
2333 	}
2334 
2335 	/*
2336 	 * Validate version
2337 	 */
2338 	if (version == 0x0) {
2339 		pr_warning("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
2340 			   cpu, apicid);
2341 		version = 0x10;
2342 	}
2343 
2344 	if (version != boot_cpu_apic_version) {
2345 		pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
2346 			boot_cpu_apic_version, cpu, version);
2347 	}
2348 
2349 	if (apicid > max_physical_apicid)
2350 		max_physical_apicid = apicid;
2351 
2352 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
2353 	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
2354 	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
2355 #endif
2356 #ifdef CONFIG_X86_32
2357 	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
2358 		apic->x86_32_early_logical_apicid(cpu);
2359 #endif
2360 	set_cpu_possible(cpu, true);
2361 	physid_set(apicid, phys_cpu_present_map);
2362 	set_cpu_present(cpu, true);
2363 	num_processors++;
2364 
2365 	return cpu;
2366 }
2367 
2368 int hard_smp_processor_id(void)
2369 {
2370 	return read_apic_id();
2371 }
2372 
2373 /*
2374  * Override the generic EOI implementation with an optimized version.
2375  * Only called during early boot when only one CPU is active and with
2376  * interrupts disabled, so we know this does not race with actual APIC driver
2377  * use.
2378  */
2379 void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v))
2380 {
2381 	struct apic **drv;
2382 
2383 	for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
2384 		/* Should happen once for each apic */
2385 		WARN_ON((*drv)->eoi_write == eoi_write);
2386 		(*drv)->native_eoi_write = (*drv)->eoi_write;
2387 		(*drv)->eoi_write = eoi_write;
2388 	}
2389 }
2390 
2391 static void __init apic_bsp_up_setup(void)
2392 {
2393 #ifdef CONFIG_X86_64
2394 	apic_write(APIC_ID, apic->set_apic_id(boot_cpu_physical_apicid));
2395 #else
2396 	/*
2397 	 * Hack: In case of kdump, after a crash, kernel might be booting
2398 	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
2399 	 * might be zero if read from MP tables. Get it from LAPIC.
2400 	 */
2401 # ifdef CONFIG_CRASH_DUMP
2402 	boot_cpu_physical_apicid = read_apic_id();
2403 # endif
2404 #endif
2405 	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
2406 }
2407 
2408 /**
2409  * apic_bsp_setup - Setup function for local apic and io-apic
2410  * @upmode:		Force UP mode (for APIC_init_uniprocessor)
2411  *
2412  * Returns:
2413  * apic_id of BSP APIC
2414  */
2415 void __init apic_bsp_setup(bool upmode)
2416 {
2417 	connect_bsp_APIC();
2418 	if (upmode)
2419 		apic_bsp_up_setup();
2420 	setup_local_APIC();
2421 
2422 	enable_IO_APIC();
2423 	end_local_APIC_setup();
2424 	irq_remap_enable_fault_handling();
2425 	setup_IO_APIC();
2426 }
2427 
2428 #ifdef CONFIG_UP_LATE_INIT
2429 void __init up_late_init(void)
2430 {
2431 	if (apic_intr_mode == APIC_PIC)
2432 		return;
2433 
2434 	/* Setup local timer */
2435 	x86_init.timers.setup_percpu_clockev();
2436 }
2437 #endif
2438 
2439 /*
2440  * Power management
2441  */
2442 #ifdef CONFIG_PM
2443 
2444 static struct {
2445 	/*
2446 	 * 'active' is true if the local APIC was enabled by us and
2447 	 * not the BIOS; this signifies that we are also responsible
2448 	 * for disabling it before entering apm/acpi suspend
2449 	 */
2450 	int active;
2451 	/* r/w apic fields */
2452 	unsigned int apic_id;
2453 	unsigned int apic_taskpri;
2454 	unsigned int apic_ldr;
2455 	unsigned int apic_dfr;
2456 	unsigned int apic_spiv;
2457 	unsigned int apic_lvtt;
2458 	unsigned int apic_lvtpc;
2459 	unsigned int apic_lvt0;
2460 	unsigned int apic_lvt1;
2461 	unsigned int apic_lvterr;
2462 	unsigned int apic_tmict;
2463 	unsigned int apic_tdcr;
2464 	unsigned int apic_thmr;
2465 	unsigned int apic_cmci;
2466 } apic_pm_state;
2467 
2468 static int lapic_suspend(void)
2469 {
2470 	unsigned long flags;
2471 	int maxlvt;
2472 
2473 	if (!apic_pm_state.active)
2474 		return 0;
2475 
2476 	maxlvt = lapic_get_maxlvt();
2477 
2478 	apic_pm_state.apic_id = apic_read(APIC_ID);
2479 	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2480 	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2481 	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2482 	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2483 	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2484 	if (maxlvt >= 4)
2485 		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2486 	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2487 	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2488 	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2489 	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2490 	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2491 #ifdef CONFIG_X86_THERMAL_VECTOR
2492 	if (maxlvt >= 5)
2493 		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2494 #endif
2495 #ifdef CONFIG_X86_MCE_INTEL
2496 	if (maxlvt >= 6)
2497 		apic_pm_state.apic_cmci = apic_read(APIC_LVTCMCI);
2498 #endif
2499 
2500 	local_irq_save(flags);
2501 	disable_local_APIC();
2502 
2503 	irq_remapping_disable();
2504 
2505 	local_irq_restore(flags);
2506 	return 0;
2507 }
2508 
2509 static void lapic_resume(void)
2510 {
2511 	unsigned int l, h;
2512 	unsigned long flags;
2513 	int maxlvt;
2514 
2515 	if (!apic_pm_state.active)
2516 		return;
2517 
2518 	local_irq_save(flags);
2519 
2520 	/*
2521 	 * IO-APIC and PIC have their own resume routines.
2522 	 * We just mask them here to make sure the interrupt
2523 	 * subsystem is completely quiet while we enable x2apic
2524 	 * and interrupt-remapping.
2525 	 */
2526 	mask_ioapic_entries();
2527 	legacy_pic->mask_all();
2528 
2529 	if (x2apic_mode) {
2530 		__x2apic_enable();
2531 	} else {
2532 		/*
2533 		 * Make sure the APICBASE points to the right address
2534 		 *
2535 		 * FIXME! This will be wrong if we ever support suspend on
2536 		 * SMP! We'll need to do this as part of the CPU restore!
2537 		 */
2538 		if (boot_cpu_data.x86 >= 6) {
2539 			rdmsr(MSR_IA32_APICBASE, l, h);
2540 			l &= ~MSR_IA32_APICBASE_BASE;
2541 			l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2542 			wrmsr(MSR_IA32_APICBASE, l, h);
2543 		}
2544 	}
2545 
2546 	maxlvt = lapic_get_maxlvt();
2547 	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2548 	apic_write(APIC_ID, apic_pm_state.apic_id);
2549 	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2550 	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2551 	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2552 	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2553 	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2554 	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2555 #ifdef CONFIG_X86_THERMAL_VECTOR
2556 	if (maxlvt >= 5)
2557 		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2558 #endif
2559 #ifdef CONFIG_X86_MCE_INTEL
2560 	if (maxlvt >= 6)
2561 		apic_write(APIC_LVTCMCI, apic_pm_state.apic_cmci);
2562 #endif
2563 	if (maxlvt >= 4)
2564 		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2565 	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2566 	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2567 	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2568 	apic_write(APIC_ESR, 0);
2569 	apic_read(APIC_ESR);
2570 	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2571 	apic_write(APIC_ESR, 0);
2572 	apic_read(APIC_ESR);
2573 
2574 	irq_remapping_reenable(x2apic_mode);
2575 
2576 	local_irq_restore(flags);
2577 }
2578 
2579 /*
2580  * This device has no shutdown method - fully functioning local APICs
2581  * are needed on every CPU up until machine_halt/restart/poweroff.
2582  */
2583 
2584 static struct syscore_ops lapic_syscore_ops = {
2585 	.resume		= lapic_resume,
2586 	.suspend	= lapic_suspend,
2587 };
2588 
2589 static void apic_pm_activate(void)
2590 {
2591 	apic_pm_state.active = 1;
2592 }
2593 
2594 static int __init init_lapic_sysfs(void)
2595 {
2596 	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2597 	if (boot_cpu_has(X86_FEATURE_APIC))
2598 		register_syscore_ops(&lapic_syscore_ops);
2599 
2600 	return 0;
2601 }
2602 
2603 /* local apic needs to resume before other devices access its registers. */
2604 core_initcall(init_lapic_sysfs);
2605 
2606 #else	/* CONFIG_PM */
2607 
2608 static void apic_pm_activate(void) { }
2609 
2610 #endif	/* CONFIG_PM */
2611 
2612 #ifdef CONFIG_X86_64
2613 
2614 static int multi_checked;
2615 static int multi;
2616 
2617 static int set_multi(const struct dmi_system_id *d)
2618 {
2619 	if (multi)
2620 		return 0;
2621 	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2622 	multi = 1;
2623 	return 0;
2624 }
2625 
2626 static const struct dmi_system_id multi_dmi_table[] = {
2627 	{
2628 		.callback = set_multi,
2629 		.ident = "IBM System Summit2",
2630 		.matches = {
2631 			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2632 			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2633 		},
2634 	},
2635 	{}
2636 };
2637 
2638 static void dmi_check_multi(void)
2639 {
2640 	if (multi_checked)
2641 		return;
2642 
2643 	dmi_check_system(multi_dmi_table);
2644 	multi_checked = 1;
2645 }
2646 
2647 /*
2648  * apic_is_clustered_box() -- Check if we can expect good TSC
2649  *
2650  * Thus far, the major user of this is IBM's Summit2 series:
2651  * Clustered boxes may have unsynced TSC problems if they are
2652  * multi-chassis.
2653  * Use DMI to check them
2654  */
2655 int apic_is_clustered_box(void)
2656 {
2657 	dmi_check_multi();
2658 	return multi;
2659 }
2660 #endif
2661 
2662 /*
2663  * APIC command line parameters
2664  */
2665 static int __init setup_disableapic(char *arg)
2666 {
2667 	disable_apic = 1;
2668 	setup_clear_cpu_cap(X86_FEATURE_APIC);
2669 	return 0;
2670 }
2671 early_param("disableapic", setup_disableapic);
2672 
2673 /* same as disableapic, for compatibility */
2674 static int __init setup_nolapic(char *arg)
2675 {
2676 	return setup_disableapic(arg);
2677 }
2678 early_param("nolapic", setup_nolapic);
2679 
2680 static int __init parse_lapic_timer_c2_ok(char *arg)
2681 {
2682 	local_apic_timer_c2_ok = 1;
2683 	return 0;
2684 }
2685 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2686 
2687 static int __init parse_disable_apic_timer(char *arg)
2688 {
2689 	disable_apic_timer = 1;
2690 	return 0;
2691 }
2692 early_param("noapictimer", parse_disable_apic_timer);
2693 
2694 static int __init parse_nolapic_timer(char *arg)
2695 {
2696 	disable_apic_timer = 1;
2697 	return 0;
2698 }
2699 early_param("nolapic_timer", parse_nolapic_timer);
2700 
2701 static int __init apic_set_verbosity(char *arg)
2702 {
2703 	if (!arg)  {
2704 #ifdef CONFIG_X86_64
2705 		skip_ioapic_setup = 0;
2706 		return 0;
2707 #endif
2708 		return -EINVAL;
2709 	}
2710 
2711 	if (strcmp("debug", arg) == 0)
2712 		apic_verbosity = APIC_DEBUG;
2713 	else if (strcmp("verbose", arg) == 0)
2714 		apic_verbosity = APIC_VERBOSE;
2715 #ifdef CONFIG_X86_64
2716 	else {
2717 		pr_warning("APIC Verbosity level %s not recognised"
2718 			" use apic=verbose or apic=debug\n", arg);
2719 		return -EINVAL;
2720 	}
2721 #endif
2722 
2723 	return 0;
2724 }
2725 early_param("apic", apic_set_verbosity);
2726 
2727 static int __init lapic_insert_resource(void)
2728 {
2729 	if (!apic_phys)
2730 		return -1;
2731 
2732 	/* Put local APIC into the resource map. */
2733 	lapic_resource.start = apic_phys;
2734 	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2735 	insert_resource(&iomem_resource, &lapic_resource);
2736 
2737 	return 0;
2738 }
2739 
2740 /*
2741  * need call insert after e820__reserve_resources()
2742  * that is using request_resource
2743  */
2744 late_initcall(lapic_insert_resource);
2745 
2746 static int __init apic_set_disabled_cpu_apicid(char *arg)
2747 {
2748 	if (!arg || !get_option(&arg, &disabled_cpu_apicid))
2749 		return -EINVAL;
2750 
2751 	return 0;
2752 }
2753 early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);
2754 
2755 static int __init apic_set_extnmi(char *arg)
2756 {
2757 	if (!arg)
2758 		return -EINVAL;
2759 
2760 	if (!strncmp("all", arg, 3))
2761 		apic_extnmi = APIC_EXTNMI_ALL;
2762 	else if (!strncmp("none", arg, 4))
2763 		apic_extnmi = APIC_EXTNMI_NONE;
2764 	else if (!strncmp("bsp", arg, 3))
2765 		apic_extnmi = APIC_EXTNMI_BSP;
2766 	else {
2767 		pr_warn("Unknown external NMI delivery mode `%s' ignored\n", arg);
2768 		return -EINVAL;
2769 	}
2770 
2771 	return 0;
2772 }
2773 early_param("apic_extnmi", apic_set_extnmi);
2774