xref: /openbmc/linux/arch/x86/kernel/apic/apic.c (revision e6e8c82b)
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/traps.h>
48 #include <asm/apic.h>
49 #include <asm/io_apic.h>
50 #include <asm/desc.h>
51 #include <asm/hpet.h>
52 #include <asm/mtrr.h>
53 #include <asm/time.h>
54 #include <asm/smp.h>
55 #include <asm/mce.h>
56 #include <asm/tsc.h>
57 #include <asm/hypervisor.h>
58 #include <asm/cpu_device_id.h>
59 #include <asm/intel-family.h>
60 #include <asm/irq_regs.h>
61 
62 unsigned int num_processors;
63 
64 unsigned disabled_cpus;
65 
66 /* Processor that is doing the boot up */
67 unsigned int boot_cpu_physical_apicid = -1U;
68 EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
69 
70 u8 boot_cpu_apic_version;
71 
72 /*
73  * The highest APIC ID seen during enumeration.
74  */
75 static unsigned int max_physical_apicid;
76 
77 /*
78  * Bitmask of physically existing CPUs:
79  */
80 physid_mask_t phys_cpu_present_map;
81 
82 /*
83  * Processor to be disabled specified by kernel parameter
84  * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
85  * avoid undefined behaviour caused by sending INIT from AP to BSP.
86  */
87 static unsigned int disabled_cpu_apicid __read_mostly = BAD_APICID;
88 
89 /*
90  * This variable controls which CPUs receive external NMIs.  By default,
91  * external NMIs are delivered only to the BSP.
92  */
93 static int apic_extnmi = APIC_EXTNMI_BSP;
94 
95 /*
96  * Map cpu index to physical APIC ID
97  */
98 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid, BAD_APICID);
99 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_bios_cpu_apicid, BAD_APICID);
100 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, U32_MAX);
101 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
102 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
103 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
104 
105 #ifdef CONFIG_X86_32
106 
107 /*
108  * On x86_32, the mapping between cpu and logical apicid may vary
109  * depending on apic in use.  The following early percpu variable is
110  * used for the mapping.  This is where the behaviors of x86_64 and 32
111  * actually diverge.  Let's keep it ugly for now.
112  */
113 DEFINE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid, BAD_APICID);
114 
115 /* Local APIC was disabled by the BIOS and enabled by the kernel */
116 static int enabled_via_apicbase;
117 
118 /*
119  * Handle interrupt mode configuration register (IMCR).
120  * This register controls whether the interrupt signals
121  * that reach the BSP come from the master PIC or from the
122  * local APIC. Before entering Symmetric I/O Mode, either
123  * the BIOS or the operating system must switch out of
124  * PIC Mode by changing the IMCR.
125  */
126 static inline void imcr_pic_to_apic(void)
127 {
128 	/* select IMCR register */
129 	outb(0x70, 0x22);
130 	/* NMI and 8259 INTR go through APIC */
131 	outb(0x01, 0x23);
132 }
133 
134 static inline void imcr_apic_to_pic(void)
135 {
136 	/* select IMCR register */
137 	outb(0x70, 0x22);
138 	/* NMI and 8259 INTR go directly to BSP */
139 	outb(0x00, 0x23);
140 }
141 #endif
142 
143 /*
144  * Knob to control our willingness to enable the local APIC.
145  *
146  * +1=force-enable
147  */
148 static int force_enable_local_apic __initdata;
149 
150 /*
151  * APIC command line parameters
152  */
153 static int __init parse_lapic(char *arg)
154 {
155 	if (IS_ENABLED(CONFIG_X86_32) && !arg)
156 		force_enable_local_apic = 1;
157 	else if (arg && !strncmp(arg, "notscdeadline", 13))
158 		setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
159 	return 0;
160 }
161 early_param("lapic", parse_lapic);
162 
163 #ifdef CONFIG_X86_64
164 static int apic_calibrate_pmtmr __initdata;
165 static __init int setup_apicpmtimer(char *s)
166 {
167 	apic_calibrate_pmtmr = 1;
168 	notsc_setup(NULL);
169 	return 0;
170 }
171 __setup("apicpmtimer", setup_apicpmtimer);
172 #endif
173 
174 unsigned long mp_lapic_addr;
175 int disable_apic;
176 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
177 static int disable_apic_timer __initdata;
178 /* Local APIC timer works in C2 */
179 int local_apic_timer_c2_ok;
180 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
181 
182 /*
183  * Debug level, exported for io_apic.c
184  */
185 unsigned int apic_verbosity;
186 
187 int pic_mode;
188 
189 /* Have we found an MP table */
190 int smp_found_config;
191 
192 static struct resource lapic_resource = {
193 	.name = "Local APIC",
194 	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
195 };
196 
197 unsigned int lapic_timer_frequency = 0;
198 
199 static void apic_pm_activate(void);
200 
201 static unsigned long apic_phys;
202 
203 /*
204  * Get the LAPIC version
205  */
206 static inline int lapic_get_version(void)
207 {
208 	return GET_APIC_VERSION(apic_read(APIC_LVR));
209 }
210 
211 /*
212  * Check, if the APIC is integrated or a separate chip
213  */
214 static inline int lapic_is_integrated(void)
215 {
216 	return APIC_INTEGRATED(lapic_get_version());
217 }
218 
219 /*
220  * Check, whether this is a modern or a first generation APIC
221  */
222 static int modern_apic(void)
223 {
224 	/* AMD systems use old APIC versions, so check the CPU */
225 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
226 	    boot_cpu_data.x86 >= 0xf)
227 		return 1;
228 
229 	/* Hygon systems use modern APIC */
230 	if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
231 		return 1;
232 
233 	return lapic_get_version() >= 0x14;
234 }
235 
236 /*
237  * right after this call apic become NOOP driven
238  * so apic->write/read doesn't do anything
239  */
240 static void __init apic_disable(void)
241 {
242 	pr_info("APIC: switched to apic NOOP\n");
243 	apic = &apic_noop;
244 }
245 
246 void native_apic_wait_icr_idle(void)
247 {
248 	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
249 		cpu_relax();
250 }
251 
252 u32 native_safe_apic_wait_icr_idle(void)
253 {
254 	u32 send_status;
255 	int timeout;
256 
257 	timeout = 0;
258 	do {
259 		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
260 		if (!send_status)
261 			break;
262 		inc_irq_stat(icr_read_retry_count);
263 		udelay(100);
264 	} while (timeout++ < 1000);
265 
266 	return send_status;
267 }
268 
269 void native_apic_icr_write(u32 low, u32 id)
270 {
271 	unsigned long flags;
272 
273 	local_irq_save(flags);
274 	apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
275 	apic_write(APIC_ICR, low);
276 	local_irq_restore(flags);
277 }
278 
279 u64 native_apic_icr_read(void)
280 {
281 	u32 icr1, icr2;
282 
283 	icr2 = apic_read(APIC_ICR2);
284 	icr1 = apic_read(APIC_ICR);
285 
286 	return icr1 | ((u64)icr2 << 32);
287 }
288 
289 #ifdef CONFIG_X86_32
290 /**
291  * get_physical_broadcast - Get number of physical broadcast IDs
292  */
293 int get_physical_broadcast(void)
294 {
295 	return modern_apic() ? 0xff : 0xf;
296 }
297 #endif
298 
299 /**
300  * lapic_get_maxlvt - get the maximum number of local vector table entries
301  */
302 int lapic_get_maxlvt(void)
303 {
304 	/*
305 	 * - we always have APIC integrated on 64bit mode
306 	 * - 82489DXs do not report # of LVT entries
307 	 */
308 	return lapic_is_integrated() ? GET_APIC_MAXLVT(apic_read(APIC_LVR)) : 2;
309 }
310 
311 /*
312  * Local APIC timer
313  */
314 
315 /* Clock divisor */
316 #define APIC_DIVISOR 16
317 #define TSC_DIVISOR  8
318 
319 /*
320  * This function sets up the local APIC timer, with a timeout of
321  * 'clocks' APIC bus clock. During calibration we actually call
322  * this function twice on the boot CPU, once with a bogus timeout
323  * value, second time for real. The other (noncalibrating) CPUs
324  * call this function only once, with the real, calibrated value.
325  *
326  * We do reads before writes even if unnecessary, to get around the
327  * P5 APIC double write bug.
328  */
329 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
330 {
331 	unsigned int lvtt_value, tmp_value;
332 
333 	lvtt_value = LOCAL_TIMER_VECTOR;
334 	if (!oneshot)
335 		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
336 	else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
337 		lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE;
338 
339 	if (!lapic_is_integrated())
340 		lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
341 
342 	if (!irqen)
343 		lvtt_value |= APIC_LVT_MASKED;
344 
345 	apic_write(APIC_LVTT, lvtt_value);
346 
347 	if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) {
348 		/*
349 		 * See Intel SDM: TSC-Deadline Mode chapter. In xAPIC mode,
350 		 * writing to the APIC LVTT and TSC_DEADLINE MSR isn't serialized.
351 		 * According to Intel, MFENCE can do the serialization here.
352 		 */
353 		asm volatile("mfence" : : : "memory");
354 
355 		printk_once(KERN_DEBUG "TSC deadline timer enabled\n");
356 		return;
357 	}
358 
359 	/*
360 	 * Divide PICLK by 16
361 	 */
362 	tmp_value = apic_read(APIC_TDCR);
363 	apic_write(APIC_TDCR,
364 		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
365 		APIC_TDR_DIV_16);
366 
367 	if (!oneshot)
368 		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
369 }
370 
371 /*
372  * Setup extended LVT, AMD specific
373  *
374  * Software should use the LVT offsets the BIOS provides.  The offsets
375  * are determined by the subsystems using it like those for MCE
376  * threshold or IBS.  On K8 only offset 0 (APIC500) and MCE interrupts
377  * are supported. Beginning with family 10h at least 4 offsets are
378  * available.
379  *
380  * Since the offsets must be consistent for all cores, we keep track
381  * of the LVT offsets in software and reserve the offset for the same
382  * vector also to be used on other cores. An offset is freed by
383  * setting the entry to APIC_EILVT_MASKED.
384  *
385  * If the BIOS is right, there should be no conflicts. Otherwise a
386  * "[Firmware Bug]: ..." error message is generated. However, if
387  * software does not properly determines the offsets, it is not
388  * necessarily a BIOS bug.
389  */
390 
391 static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
392 
393 static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
394 {
395 	return (old & APIC_EILVT_MASKED)
396 		|| (new == APIC_EILVT_MASKED)
397 		|| ((new & ~APIC_EILVT_MASKED) == old);
398 }
399 
400 static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
401 {
402 	unsigned int rsvd, vector;
403 
404 	if (offset >= APIC_EILVT_NR_MAX)
405 		return ~0;
406 
407 	rsvd = atomic_read(&eilvt_offsets[offset]);
408 	do {
409 		vector = rsvd & ~APIC_EILVT_MASKED;	/* 0: unassigned */
410 		if (vector && !eilvt_entry_is_changeable(vector, new))
411 			/* may not change if vectors are different */
412 			return rsvd;
413 		rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new);
414 	} while (rsvd != new);
415 
416 	rsvd &= ~APIC_EILVT_MASKED;
417 	if (rsvd && rsvd != vector)
418 		pr_info("LVT offset %d assigned for vector 0x%02x\n",
419 			offset, rsvd);
420 
421 	return new;
422 }
423 
424 /*
425  * If mask=1, the LVT entry does not generate interrupts while mask=0
426  * enables the vector. See also the BKDGs. Must be called with
427  * preemption disabled.
428  */
429 
430 int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
431 {
432 	unsigned long reg = APIC_EILVTn(offset);
433 	unsigned int new, old, reserved;
434 
435 	new = (mask << 16) | (msg_type << 8) | vector;
436 	old = apic_read(reg);
437 	reserved = reserve_eilvt_offset(offset, new);
438 
439 	if (reserved != new) {
440 		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
441 		       "vector 0x%x, but the register is already in use for "
442 		       "vector 0x%x on another cpu\n",
443 		       smp_processor_id(), reg, offset, new, reserved);
444 		return -EINVAL;
445 	}
446 
447 	if (!eilvt_entry_is_changeable(old, new)) {
448 		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
449 		       "vector 0x%x, but the register is already in use for "
450 		       "vector 0x%x on this cpu\n",
451 		       smp_processor_id(), reg, offset, new, old);
452 		return -EBUSY;
453 	}
454 
455 	apic_write(reg, new);
456 
457 	return 0;
458 }
459 EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
460 
461 /*
462  * Program the next event, relative to now
463  */
464 static int lapic_next_event(unsigned long delta,
465 			    struct clock_event_device *evt)
466 {
467 	apic_write(APIC_TMICT, delta);
468 	return 0;
469 }
470 
471 static int lapic_next_deadline(unsigned long delta,
472 			       struct clock_event_device *evt)
473 {
474 	u64 tsc;
475 
476 	tsc = rdtsc();
477 	wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR));
478 	return 0;
479 }
480 
481 static int lapic_timer_shutdown(struct clock_event_device *evt)
482 {
483 	unsigned int v;
484 
485 	/* Lapic used as dummy for broadcast ? */
486 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
487 		return 0;
488 
489 	v = apic_read(APIC_LVTT);
490 	v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
491 	apic_write(APIC_LVTT, v);
492 	apic_write(APIC_TMICT, 0);
493 	return 0;
494 }
495 
496 static inline int
497 lapic_timer_set_periodic_oneshot(struct clock_event_device *evt, bool oneshot)
498 {
499 	/* Lapic used as dummy for broadcast ? */
500 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
501 		return 0;
502 
503 	__setup_APIC_LVTT(lapic_timer_frequency, oneshot, 1);
504 	return 0;
505 }
506 
507 static int lapic_timer_set_periodic(struct clock_event_device *evt)
508 {
509 	return lapic_timer_set_periodic_oneshot(evt, false);
510 }
511 
512 static int lapic_timer_set_oneshot(struct clock_event_device *evt)
513 {
514 	return lapic_timer_set_periodic_oneshot(evt, true);
515 }
516 
517 /*
518  * Local APIC timer broadcast function
519  */
520 static void lapic_timer_broadcast(const struct cpumask *mask)
521 {
522 #ifdef CONFIG_SMP
523 	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
524 #endif
525 }
526 
527 
528 /*
529  * The local apic timer can be used for any function which is CPU local.
530  */
531 static struct clock_event_device lapic_clockevent = {
532 	.name				= "lapic",
533 	.features			= CLOCK_EVT_FEAT_PERIODIC |
534 					  CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP
535 					  | CLOCK_EVT_FEAT_DUMMY,
536 	.shift				= 32,
537 	.set_state_shutdown		= lapic_timer_shutdown,
538 	.set_state_periodic		= lapic_timer_set_periodic,
539 	.set_state_oneshot		= lapic_timer_set_oneshot,
540 	.set_state_oneshot_stopped	= lapic_timer_shutdown,
541 	.set_next_event			= lapic_next_event,
542 	.broadcast			= lapic_timer_broadcast,
543 	.rating				= 100,
544 	.irq				= -1,
545 };
546 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
547 
548 #define DEADLINE_MODEL_MATCH_FUNC(model, func)	\
549 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&func }
550 
551 #define DEADLINE_MODEL_MATCH_REV(model, rev)	\
552 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)rev }
553 
554 static u32 hsx_deadline_rev(void)
555 {
556 	switch (boot_cpu_data.x86_stepping) {
557 	case 0x02: return 0x3a; /* EP */
558 	case 0x04: return 0x0f; /* EX */
559 	}
560 
561 	return ~0U;
562 }
563 
564 static u32 bdx_deadline_rev(void)
565 {
566 	switch (boot_cpu_data.x86_stepping) {
567 	case 0x02: return 0x00000011;
568 	case 0x03: return 0x0700000e;
569 	case 0x04: return 0x0f00000c;
570 	case 0x05: return 0x0e000003;
571 	}
572 
573 	return ~0U;
574 }
575 
576 static u32 skx_deadline_rev(void)
577 {
578 	switch (boot_cpu_data.x86_stepping) {
579 	case 0x03: return 0x01000136;
580 	case 0x04: return 0x02000014;
581 	}
582 
583 	if (boot_cpu_data.x86_stepping > 4)
584 		return 0;
585 
586 	return ~0U;
587 }
588 
589 static const struct x86_cpu_id deadline_match[] = {
590 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_HASWELL_X,	hsx_deadline_rev),
591 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_X,	0x0b000020),
592 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_BROADWELL_XEON_D,	bdx_deadline_rev),
593 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_SKYLAKE_X,	skx_deadline_rev),
594 
595 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_CORE,	0x22),
596 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_ULT,	0x20),
597 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_GT3E,	0x17),
598 
599 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_CORE,	0x25),
600 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_GT3E,	0x17),
601 
602 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_MOBILE,	0xb2),
603 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_DESKTOP,	0xb2),
604 
605 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_MOBILE,	0x52),
606 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_DESKTOP,	0x52),
607 
608 	{},
609 };
610 
611 static void apic_check_deadline_errata(void)
612 {
613 	const struct x86_cpu_id *m;
614 	u32 rev;
615 
616 	if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER) ||
617 	    boot_cpu_has(X86_FEATURE_HYPERVISOR))
618 		return;
619 
620 	m = x86_match_cpu(deadline_match);
621 	if (!m)
622 		return;
623 
624 	/*
625 	 * Function pointers will have the MSB set due to address layout,
626 	 * immediate revisions will not.
627 	 */
628 	if ((long)m->driver_data < 0)
629 		rev = ((u32 (*)(void))(m->driver_data))();
630 	else
631 		rev = (u32)m->driver_data;
632 
633 	if (boot_cpu_data.microcode >= rev)
634 		return;
635 
636 	setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
637 	pr_err(FW_BUG "TSC_DEADLINE disabled due to Errata; "
638 	       "please update microcode to version: 0x%x (or later)\n", rev);
639 }
640 
641 /*
642  * Setup the local APIC timer for this CPU. Copy the initialized values
643  * of the boot CPU and register the clock event in the framework.
644  */
645 static void setup_APIC_timer(void)
646 {
647 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
648 
649 	if (this_cpu_has(X86_FEATURE_ARAT)) {
650 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
651 		/* Make LAPIC timer preferrable over percpu HPET */
652 		lapic_clockevent.rating = 150;
653 	}
654 
655 	memcpy(levt, &lapic_clockevent, sizeof(*levt));
656 	levt->cpumask = cpumask_of(smp_processor_id());
657 
658 	if (this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
659 		levt->name = "lapic-deadline";
660 		levt->features &= ~(CLOCK_EVT_FEAT_PERIODIC |
661 				    CLOCK_EVT_FEAT_DUMMY);
662 		levt->set_next_event = lapic_next_deadline;
663 		clockevents_config_and_register(levt,
664 						tsc_khz * (1000 / TSC_DIVISOR),
665 						0xF, ~0UL);
666 	} else
667 		clockevents_register_device(levt);
668 }
669 
670 /*
671  * Install the updated TSC frequency from recalibration at the TSC
672  * deadline clockevent devices.
673  */
674 static void __lapic_update_tsc_freq(void *info)
675 {
676 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
677 
678 	if (!this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
679 		return;
680 
681 	clockevents_update_freq(levt, tsc_khz * (1000 / TSC_DIVISOR));
682 }
683 
684 void lapic_update_tsc_freq(void)
685 {
686 	/*
687 	 * The clockevent device's ->mult and ->shift can both be
688 	 * changed. In order to avoid races, schedule the frequency
689 	 * update code on each CPU.
690 	 */
691 	on_each_cpu(__lapic_update_tsc_freq, NULL, 0);
692 }
693 
694 /*
695  * In this functions we calibrate APIC bus clocks to the external timer.
696  *
697  * We want to do the calibration only once since we want to have local timer
698  * irqs syncron. CPUs connected by the same APIC bus have the very same bus
699  * frequency.
700  *
701  * This was previously done by reading the PIT/HPET and waiting for a wrap
702  * around to find out, that a tick has elapsed. I have a box, where the PIT
703  * readout is broken, so it never gets out of the wait loop again. This was
704  * also reported by others.
705  *
706  * Monitoring the jiffies value is inaccurate and the clockevents
707  * infrastructure allows us to do a simple substitution of the interrupt
708  * handler.
709  *
710  * The calibration routine also uses the pm_timer when possible, as the PIT
711  * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
712  * back to normal later in the boot process).
713  */
714 
715 #define LAPIC_CAL_LOOPS		(HZ/10)
716 
717 static __initdata int lapic_cal_loops = -1;
718 static __initdata long lapic_cal_t1, lapic_cal_t2;
719 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
720 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
721 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
722 
723 /*
724  * Temporary interrupt handler.
725  */
726 static void __init lapic_cal_handler(struct clock_event_device *dev)
727 {
728 	unsigned long long tsc = 0;
729 	long tapic = apic_read(APIC_TMCCT);
730 	unsigned long pm = acpi_pm_read_early();
731 
732 	if (boot_cpu_has(X86_FEATURE_TSC))
733 		tsc = rdtsc();
734 
735 	switch (lapic_cal_loops++) {
736 	case 0:
737 		lapic_cal_t1 = tapic;
738 		lapic_cal_tsc1 = tsc;
739 		lapic_cal_pm1 = pm;
740 		lapic_cal_j1 = jiffies;
741 		break;
742 
743 	case LAPIC_CAL_LOOPS:
744 		lapic_cal_t2 = tapic;
745 		lapic_cal_tsc2 = tsc;
746 		if (pm < lapic_cal_pm1)
747 			pm += ACPI_PM_OVRRUN;
748 		lapic_cal_pm2 = pm;
749 		lapic_cal_j2 = jiffies;
750 		break;
751 	}
752 }
753 
754 static int __init
755 calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
756 {
757 	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
758 	const long pm_thresh = pm_100ms / 100;
759 	unsigned long mult;
760 	u64 res;
761 
762 #ifndef CONFIG_X86_PM_TIMER
763 	return -1;
764 #endif
765 
766 	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
767 
768 	/* Check, if the PM timer is available */
769 	if (!deltapm)
770 		return -1;
771 
772 	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
773 
774 	if (deltapm > (pm_100ms - pm_thresh) &&
775 	    deltapm < (pm_100ms + pm_thresh)) {
776 		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
777 		return 0;
778 	}
779 
780 	res = (((u64)deltapm) *  mult) >> 22;
781 	do_div(res, 1000000);
782 	pr_warning("APIC calibration not consistent "
783 		   "with PM-Timer: %ldms instead of 100ms\n",(long)res);
784 
785 	/* Correct the lapic counter value */
786 	res = (((u64)(*delta)) * pm_100ms);
787 	do_div(res, deltapm);
788 	pr_info("APIC delta adjusted to PM-Timer: "
789 		"%lu (%ld)\n", (unsigned long)res, *delta);
790 	*delta = (long)res;
791 
792 	/* Correct the tsc counter value */
793 	if (boot_cpu_has(X86_FEATURE_TSC)) {
794 		res = (((u64)(*deltatsc)) * pm_100ms);
795 		do_div(res, deltapm);
796 		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
797 					  "PM-Timer: %lu (%ld)\n",
798 					(unsigned long)res, *deltatsc);
799 		*deltatsc = (long)res;
800 	}
801 
802 	return 0;
803 }
804 
805 static int __init calibrate_APIC_clock(void)
806 {
807 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
808 	void (*real_handler)(struct clock_event_device *dev);
809 	unsigned long deltaj;
810 	long delta, deltatsc;
811 	int pm_referenced = 0;
812 
813 	/**
814 	 * check if lapic timer has already been calibrated by platform
815 	 * specific routine, such as tsc calibration code. if so, we just fill
816 	 * in the clockevent structure and return.
817 	 */
818 
819 	if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
820 		return 0;
821 	} else if (lapic_timer_frequency) {
822 		apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
823 				lapic_timer_frequency);
824 		lapic_clockevent.mult = div_sc(lapic_timer_frequency/APIC_DIVISOR,
825 					TICK_NSEC, lapic_clockevent.shift);
826 		lapic_clockevent.max_delta_ns =
827 			clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
828 		lapic_clockevent.max_delta_ticks = 0x7FFFFF;
829 		lapic_clockevent.min_delta_ns =
830 			clockevent_delta2ns(0xF, &lapic_clockevent);
831 		lapic_clockevent.min_delta_ticks = 0xF;
832 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
833 		return 0;
834 	}
835 
836 	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
837 		    "calibrating APIC timer ...\n");
838 
839 	local_irq_disable();
840 
841 	/* Replace the global interrupt handler */
842 	real_handler = global_clock_event->event_handler;
843 	global_clock_event->event_handler = lapic_cal_handler;
844 
845 	/*
846 	 * Setup the APIC counter to maximum. There is no way the lapic
847 	 * can underflow in the 100ms detection time frame
848 	 */
849 	__setup_APIC_LVTT(0xffffffff, 0, 0);
850 
851 	/* Let the interrupts run */
852 	local_irq_enable();
853 
854 	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
855 		cpu_relax();
856 
857 	local_irq_disable();
858 
859 	/* Restore the real event handler */
860 	global_clock_event->event_handler = real_handler;
861 
862 	/* Build delta t1-t2 as apic timer counts down */
863 	delta = lapic_cal_t1 - lapic_cal_t2;
864 	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
865 
866 	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
867 
868 	/* we trust the PM based calibration if possible */
869 	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
870 					&delta, &deltatsc);
871 
872 	/* Calculate the scaled math multiplication factor */
873 	lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
874 				       lapic_clockevent.shift);
875 	lapic_clockevent.max_delta_ns =
876 		clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
877 	lapic_clockevent.max_delta_ticks = 0x7FFFFFFF;
878 	lapic_clockevent.min_delta_ns =
879 		clockevent_delta2ns(0xF, &lapic_clockevent);
880 	lapic_clockevent.min_delta_ticks = 0xF;
881 
882 	lapic_timer_frequency = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
883 
884 	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
885 	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
886 	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
887 		    lapic_timer_frequency);
888 
889 	if (boot_cpu_has(X86_FEATURE_TSC)) {
890 		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
891 			    "%ld.%04ld MHz.\n",
892 			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
893 			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
894 	}
895 
896 	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
897 		    "%u.%04u MHz.\n",
898 		    lapic_timer_frequency / (1000000 / HZ),
899 		    lapic_timer_frequency % (1000000 / HZ));
900 
901 	/*
902 	 * Do a sanity check on the APIC calibration result
903 	 */
904 	if (lapic_timer_frequency < (1000000 / HZ)) {
905 		local_irq_enable();
906 		pr_warning("APIC frequency too slow, disabling apic timer\n");
907 		return -1;
908 	}
909 
910 	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
911 
912 	/*
913 	 * PM timer calibration failed or not turned on
914 	 * so lets try APIC timer based calibration
915 	 */
916 	if (!pm_referenced) {
917 		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
918 
919 		/*
920 		 * Setup the apic timer manually
921 		 */
922 		levt->event_handler = lapic_cal_handler;
923 		lapic_timer_set_periodic(levt);
924 		lapic_cal_loops = -1;
925 
926 		/* Let the interrupts run */
927 		local_irq_enable();
928 
929 		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
930 			cpu_relax();
931 
932 		/* Stop the lapic timer */
933 		local_irq_disable();
934 		lapic_timer_shutdown(levt);
935 
936 		/* Jiffies delta */
937 		deltaj = lapic_cal_j2 - lapic_cal_j1;
938 		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
939 
940 		/* Check, if the jiffies result is consistent */
941 		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
942 			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
943 		else
944 			levt->features |= CLOCK_EVT_FEAT_DUMMY;
945 	}
946 	local_irq_enable();
947 
948 	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
949 		pr_warning("APIC timer disabled due to verification failure\n");
950 		return -1;
951 	}
952 
953 	return 0;
954 }
955 
956 /*
957  * Setup the boot APIC
958  *
959  * Calibrate and verify the result.
960  */
961 void __init setup_boot_APIC_clock(void)
962 {
963 	/*
964 	 * The local apic timer can be disabled via the kernel
965 	 * commandline or from the CPU detection code. Register the lapic
966 	 * timer as a dummy clock event source on SMP systems, so the
967 	 * broadcast mechanism is used. On UP systems simply ignore it.
968 	 */
969 	if (disable_apic_timer) {
970 		pr_info("Disabling APIC timer\n");
971 		/* No broadcast on UP ! */
972 		if (num_possible_cpus() > 1) {
973 			lapic_clockevent.mult = 1;
974 			setup_APIC_timer();
975 		}
976 		return;
977 	}
978 
979 	if (calibrate_APIC_clock()) {
980 		/* No broadcast on UP ! */
981 		if (num_possible_cpus() > 1)
982 			setup_APIC_timer();
983 		return;
984 	}
985 
986 	/*
987 	 * If nmi_watchdog is set to IO_APIC, we need the
988 	 * PIT/HPET going.  Otherwise register lapic as a dummy
989 	 * device.
990 	 */
991 	lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
992 
993 	/* Setup the lapic or request the broadcast */
994 	setup_APIC_timer();
995 	amd_e400_c1e_apic_setup();
996 }
997 
998 void setup_secondary_APIC_clock(void)
999 {
1000 	setup_APIC_timer();
1001 	amd_e400_c1e_apic_setup();
1002 }
1003 
1004 /*
1005  * The guts of the apic timer interrupt
1006  */
1007 static void local_apic_timer_interrupt(void)
1008 {
1009 	struct clock_event_device *evt = this_cpu_ptr(&lapic_events);
1010 
1011 	/*
1012 	 * Normally we should not be here till LAPIC has been initialized but
1013 	 * in some cases like kdump, its possible that there is a pending LAPIC
1014 	 * timer interrupt from previous kernel's context and is delivered in
1015 	 * new kernel the moment interrupts are enabled.
1016 	 *
1017 	 * Interrupts are enabled early and LAPIC is setup much later, hence
1018 	 * its possible that when we get here evt->event_handler is NULL.
1019 	 * Check for event_handler being NULL and discard the interrupt as
1020 	 * spurious.
1021 	 */
1022 	if (!evt->event_handler) {
1023 		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n",
1024 			   smp_processor_id());
1025 		/* Switch it off */
1026 		lapic_timer_shutdown(evt);
1027 		return;
1028 	}
1029 
1030 	/*
1031 	 * the NMI deadlock-detector uses this.
1032 	 */
1033 	inc_irq_stat(apic_timer_irqs);
1034 
1035 	evt->event_handler(evt);
1036 }
1037 
1038 /*
1039  * Local APIC timer interrupt. This is the most natural way for doing
1040  * local interrupts, but local timer interrupts can be emulated by
1041  * broadcast interrupts too. [in case the hw doesn't support APIC timers]
1042  *
1043  * [ if a single-CPU system runs an SMP kernel then we call the local
1044  *   interrupt as well. Thus we cannot inline the local irq ... ]
1045  */
1046 __visible void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
1047 {
1048 	struct pt_regs *old_regs = set_irq_regs(regs);
1049 
1050 	/*
1051 	 * NOTE! We'd better ACK the irq immediately,
1052 	 * because timer handling can be slow.
1053 	 *
1054 	 * update_process_times() expects us to have done irq_enter().
1055 	 * Besides, if we don't timer interrupts ignore the global
1056 	 * interrupt lock, which is the WrongThing (tm) to do.
1057 	 */
1058 	entering_ack_irq();
1059 	trace_local_timer_entry(LOCAL_TIMER_VECTOR);
1060 	local_apic_timer_interrupt();
1061 	trace_local_timer_exit(LOCAL_TIMER_VECTOR);
1062 	exiting_irq();
1063 
1064 	set_irq_regs(old_regs);
1065 }
1066 
1067 int setup_profiling_timer(unsigned int multiplier)
1068 {
1069 	return -EINVAL;
1070 }
1071 
1072 /*
1073  * Local APIC start and shutdown
1074  */
1075 
1076 /**
1077  * clear_local_APIC - shutdown the local APIC
1078  *
1079  * This is called, when a CPU is disabled and before rebooting, so the state of
1080  * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
1081  * leftovers during boot.
1082  */
1083 void clear_local_APIC(void)
1084 {
1085 	int maxlvt;
1086 	u32 v;
1087 
1088 	/* APIC hasn't been mapped yet */
1089 	if (!x2apic_mode && !apic_phys)
1090 		return;
1091 
1092 	maxlvt = lapic_get_maxlvt();
1093 	/*
1094 	 * Masking an LVT entry can trigger a local APIC error
1095 	 * if the vector is zero. Mask LVTERR first to prevent this.
1096 	 */
1097 	if (maxlvt >= 3) {
1098 		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
1099 		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
1100 	}
1101 	/*
1102 	 * Careful: we have to set masks only first to deassert
1103 	 * any level-triggered sources.
1104 	 */
1105 	v = apic_read(APIC_LVTT);
1106 	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
1107 	v = apic_read(APIC_LVT0);
1108 	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
1109 	v = apic_read(APIC_LVT1);
1110 	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
1111 	if (maxlvt >= 4) {
1112 		v = apic_read(APIC_LVTPC);
1113 		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
1114 	}
1115 
1116 	/* lets not touch this if we didn't frob it */
1117 #ifdef CONFIG_X86_THERMAL_VECTOR
1118 	if (maxlvt >= 5) {
1119 		v = apic_read(APIC_LVTTHMR);
1120 		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
1121 	}
1122 #endif
1123 #ifdef CONFIG_X86_MCE_INTEL
1124 	if (maxlvt >= 6) {
1125 		v = apic_read(APIC_LVTCMCI);
1126 		if (!(v & APIC_LVT_MASKED))
1127 			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
1128 	}
1129 #endif
1130 
1131 	/*
1132 	 * Clean APIC state for other OSs:
1133 	 */
1134 	apic_write(APIC_LVTT, APIC_LVT_MASKED);
1135 	apic_write(APIC_LVT0, APIC_LVT_MASKED);
1136 	apic_write(APIC_LVT1, APIC_LVT_MASKED);
1137 	if (maxlvt >= 3)
1138 		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
1139 	if (maxlvt >= 4)
1140 		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
1141 
1142 	/* Integrated APIC (!82489DX) ? */
1143 	if (lapic_is_integrated()) {
1144 		if (maxlvt > 3)
1145 			/* Clear ESR due to Pentium errata 3AP and 11AP */
1146 			apic_write(APIC_ESR, 0);
1147 		apic_read(APIC_ESR);
1148 	}
1149 }
1150 
1151 /**
1152  * disable_local_APIC - clear and disable the local APIC
1153  */
1154 void disable_local_APIC(void)
1155 {
1156 	unsigned int value;
1157 
1158 	/* APIC hasn't been mapped yet */
1159 	if (!x2apic_mode && !apic_phys)
1160 		return;
1161 
1162 	clear_local_APIC();
1163 
1164 	/*
1165 	 * Disable APIC (implies clearing of registers
1166 	 * for 82489DX!).
1167 	 */
1168 	value = apic_read(APIC_SPIV);
1169 	value &= ~APIC_SPIV_APIC_ENABLED;
1170 	apic_write(APIC_SPIV, value);
1171 
1172 #ifdef CONFIG_X86_32
1173 	/*
1174 	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
1175 	 * restore the disabled state.
1176 	 */
1177 	if (enabled_via_apicbase) {
1178 		unsigned int l, h;
1179 
1180 		rdmsr(MSR_IA32_APICBASE, l, h);
1181 		l &= ~MSR_IA32_APICBASE_ENABLE;
1182 		wrmsr(MSR_IA32_APICBASE, l, h);
1183 	}
1184 #endif
1185 }
1186 
1187 /*
1188  * If Linux enabled the LAPIC against the BIOS default disable it down before
1189  * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
1190  * not power-off.  Additionally clear all LVT entries before disable_local_APIC
1191  * for the case where Linux didn't enable the LAPIC.
1192  */
1193 void lapic_shutdown(void)
1194 {
1195 	unsigned long flags;
1196 
1197 	if (!boot_cpu_has(X86_FEATURE_APIC) && !apic_from_smp_config())
1198 		return;
1199 
1200 	local_irq_save(flags);
1201 
1202 #ifdef CONFIG_X86_32
1203 	if (!enabled_via_apicbase)
1204 		clear_local_APIC();
1205 	else
1206 #endif
1207 		disable_local_APIC();
1208 
1209 
1210 	local_irq_restore(flags);
1211 }
1212 
1213 /**
1214  * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1215  */
1216 void __init sync_Arb_IDs(void)
1217 {
1218 	/*
1219 	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1220 	 * needed on AMD.
1221 	 */
1222 	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1223 		return;
1224 
1225 	/*
1226 	 * Wait for idle.
1227 	 */
1228 	apic_wait_icr_idle();
1229 
1230 	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1231 	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1232 			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1233 }
1234 
1235 enum apic_intr_mode_id apic_intr_mode;
1236 
1237 static int __init apic_intr_mode_select(void)
1238 {
1239 	/* Check kernel option */
1240 	if (disable_apic) {
1241 		pr_info("APIC disabled via kernel command line\n");
1242 		return APIC_PIC;
1243 	}
1244 
1245 	/* Check BIOS */
1246 #ifdef CONFIG_X86_64
1247 	/* On 64-bit, the APIC must be integrated, Check local APIC only */
1248 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1249 		disable_apic = 1;
1250 		pr_info("APIC disabled by BIOS\n");
1251 		return APIC_PIC;
1252 	}
1253 #else
1254 	/* On 32-bit, the APIC may be integrated APIC or 82489DX */
1255 
1256 	/* Neither 82489DX nor integrated APIC ? */
1257 	if (!boot_cpu_has(X86_FEATURE_APIC) && !smp_found_config) {
1258 		disable_apic = 1;
1259 		return APIC_PIC;
1260 	}
1261 
1262 	/* If the BIOS pretends there is an integrated APIC ? */
1263 	if (!boot_cpu_has(X86_FEATURE_APIC) &&
1264 		APIC_INTEGRATED(boot_cpu_apic_version)) {
1265 		disable_apic = 1;
1266 		pr_err(FW_BUG "Local APIC %d not detected, force emulation\n",
1267 				       boot_cpu_physical_apicid);
1268 		return APIC_PIC;
1269 	}
1270 #endif
1271 
1272 	/* Check MP table or ACPI MADT configuration */
1273 	if (!smp_found_config) {
1274 		disable_ioapic_support();
1275 		if (!acpi_lapic) {
1276 			pr_info("APIC: ACPI MADT or MP tables are not detected\n");
1277 			return APIC_VIRTUAL_WIRE_NO_CONFIG;
1278 		}
1279 		return APIC_VIRTUAL_WIRE;
1280 	}
1281 
1282 #ifdef CONFIG_SMP
1283 	/* If SMP should be disabled, then really disable it! */
1284 	if (!setup_max_cpus) {
1285 		pr_info("APIC: SMP mode deactivated\n");
1286 		return APIC_SYMMETRIC_IO_NO_ROUTING;
1287 	}
1288 
1289 	if (read_apic_id() != boot_cpu_physical_apicid) {
1290 		panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
1291 		     read_apic_id(), boot_cpu_physical_apicid);
1292 		/* Or can we switch back to PIC here? */
1293 	}
1294 #endif
1295 
1296 	return APIC_SYMMETRIC_IO;
1297 }
1298 
1299 /*
1300  * An initial setup of the virtual wire mode.
1301  */
1302 void __init init_bsp_APIC(void)
1303 {
1304 	unsigned int value;
1305 
1306 	/*
1307 	 * Don't do the setup now if we have a SMP BIOS as the
1308 	 * through-I/O-APIC virtual wire mode might be active.
1309 	 */
1310 	if (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC))
1311 		return;
1312 
1313 	/*
1314 	 * Do not trust the local APIC being empty at bootup.
1315 	 */
1316 	clear_local_APIC();
1317 
1318 	/*
1319 	 * Enable APIC.
1320 	 */
1321 	value = apic_read(APIC_SPIV);
1322 	value &= ~APIC_VECTOR_MASK;
1323 	value |= APIC_SPIV_APIC_ENABLED;
1324 
1325 #ifdef CONFIG_X86_32
1326 	/* This bit is reserved on P4/Xeon and should be cleared */
1327 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1328 	    (boot_cpu_data.x86 == 15))
1329 		value &= ~APIC_SPIV_FOCUS_DISABLED;
1330 	else
1331 #endif
1332 		value |= APIC_SPIV_FOCUS_DISABLED;
1333 	value |= SPURIOUS_APIC_VECTOR;
1334 	apic_write(APIC_SPIV, value);
1335 
1336 	/*
1337 	 * Set up the virtual wire mode.
1338 	 */
1339 	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1340 	value = APIC_DM_NMI;
1341 	if (!lapic_is_integrated())		/* 82489DX */
1342 		value |= APIC_LVT_LEVEL_TRIGGER;
1343 	if (apic_extnmi == APIC_EXTNMI_NONE)
1344 		value |= APIC_LVT_MASKED;
1345 	apic_write(APIC_LVT1, value);
1346 }
1347 
1348 /* Init the interrupt delivery mode for the BSP */
1349 void __init apic_intr_mode_init(void)
1350 {
1351 	bool upmode = IS_ENABLED(CONFIG_UP_LATE_INIT);
1352 
1353 	apic_intr_mode = apic_intr_mode_select();
1354 
1355 	switch (apic_intr_mode) {
1356 	case APIC_PIC:
1357 		pr_info("APIC: Keep in PIC mode(8259)\n");
1358 		return;
1359 	case APIC_VIRTUAL_WIRE:
1360 		pr_info("APIC: Switch to virtual wire mode setup\n");
1361 		default_setup_apic_routing();
1362 		break;
1363 	case APIC_VIRTUAL_WIRE_NO_CONFIG:
1364 		pr_info("APIC: Switch to virtual wire mode setup with no configuration\n");
1365 		upmode = true;
1366 		default_setup_apic_routing();
1367 		break;
1368 	case APIC_SYMMETRIC_IO:
1369 		pr_info("APIC: Switch to symmetric I/O mode setup\n");
1370 		default_setup_apic_routing();
1371 		break;
1372 	case APIC_SYMMETRIC_IO_NO_ROUTING:
1373 		pr_info("APIC: Switch to symmetric I/O mode setup in no SMP routine\n");
1374 		break;
1375 	}
1376 
1377 	apic_bsp_setup(upmode);
1378 }
1379 
1380 static void lapic_setup_esr(void)
1381 {
1382 	unsigned int oldvalue, value, maxlvt;
1383 
1384 	if (!lapic_is_integrated()) {
1385 		pr_info("No ESR for 82489DX.\n");
1386 		return;
1387 	}
1388 
1389 	if (apic->disable_esr) {
1390 		/*
1391 		 * Something untraceable is creating bad interrupts on
1392 		 * secondary quads ... for the moment, just leave the
1393 		 * ESR disabled - we can't do anything useful with the
1394 		 * errors anyway - mbligh
1395 		 */
1396 		pr_info("Leaving ESR disabled.\n");
1397 		return;
1398 	}
1399 
1400 	maxlvt = lapic_get_maxlvt();
1401 	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1402 		apic_write(APIC_ESR, 0);
1403 	oldvalue = apic_read(APIC_ESR);
1404 
1405 	/* enables sending errors */
1406 	value = ERROR_APIC_VECTOR;
1407 	apic_write(APIC_LVTERR, value);
1408 
1409 	/*
1410 	 * spec says clear errors after enabling vector.
1411 	 */
1412 	if (maxlvt > 3)
1413 		apic_write(APIC_ESR, 0);
1414 	value = apic_read(APIC_ESR);
1415 	if (value != oldvalue)
1416 		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1417 			"vector: 0x%08x  after: 0x%08x\n",
1418 			oldvalue, value);
1419 }
1420 
1421 static void apic_pending_intr_clear(void)
1422 {
1423 	long long max_loops = cpu_khz ? cpu_khz : 1000000;
1424 	unsigned long long tsc = 0, ntsc;
1425 	unsigned int queued;
1426 	unsigned long value;
1427 	int i, j, acked = 0;
1428 
1429 	if (boot_cpu_has(X86_FEATURE_TSC))
1430 		tsc = rdtsc();
1431 	/*
1432 	 * After a crash, we no longer service the interrupts and a pending
1433 	 * interrupt from previous kernel might still have ISR bit set.
1434 	 *
1435 	 * Most probably by now CPU has serviced that pending interrupt and
1436 	 * it might not have done the ack_APIC_irq() because it thought,
1437 	 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1438 	 * does not clear the ISR bit and cpu thinks it has already serivced
1439 	 * the interrupt. Hence a vector might get locked. It was noticed
1440 	 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1441 	 */
1442 	do {
1443 		queued = 0;
1444 		for (i = APIC_ISR_NR - 1; i >= 0; i--)
1445 			queued |= apic_read(APIC_IRR + i*0x10);
1446 
1447 		for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1448 			value = apic_read(APIC_ISR + i*0x10);
1449 			for_each_set_bit(j, &value, 32) {
1450 				ack_APIC_irq();
1451 				acked++;
1452 			}
1453 		}
1454 		if (acked > 256) {
1455 			pr_err("LAPIC pending interrupts after %d EOI\n", acked);
1456 			break;
1457 		}
1458 		if (queued) {
1459 			if (boot_cpu_has(X86_FEATURE_TSC) && cpu_khz) {
1460 				ntsc = rdtsc();
1461 				max_loops = (cpu_khz << 10) - (ntsc - tsc);
1462 			} else {
1463 				max_loops--;
1464 			}
1465 		}
1466 	} while (queued && max_loops > 0);
1467 	WARN_ON(max_loops <= 0);
1468 }
1469 
1470 /**
1471  * setup_local_APIC - setup the local APIC
1472  *
1473  * Used to setup local APIC while initializing BSP or bringing up APs.
1474  * Always called with preemption disabled.
1475  */
1476 static void setup_local_APIC(void)
1477 {
1478 	int cpu = smp_processor_id();
1479 	unsigned int value;
1480 #ifdef CONFIG_X86_32
1481 	int logical_apicid, ldr_apicid;
1482 #endif
1483 
1484 
1485 	if (disable_apic) {
1486 		disable_ioapic_support();
1487 		return;
1488 	}
1489 
1490 #ifdef CONFIG_X86_32
1491 	/* Pound the ESR really hard over the head with a big hammer - mbligh */
1492 	if (lapic_is_integrated() && apic->disable_esr) {
1493 		apic_write(APIC_ESR, 0);
1494 		apic_write(APIC_ESR, 0);
1495 		apic_write(APIC_ESR, 0);
1496 		apic_write(APIC_ESR, 0);
1497 	}
1498 #endif
1499 	perf_events_lapic_init();
1500 
1501 	/*
1502 	 * Double-check whether this APIC is really registered.
1503 	 * This is meaningless in clustered apic mode, so we skip it.
1504 	 */
1505 	BUG_ON(!apic->apic_id_registered());
1506 
1507 	/*
1508 	 * Intel recommends to set DFR, LDR and TPR before enabling
1509 	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
1510 	 * document number 292116).  So here it goes...
1511 	 */
1512 	apic->init_apic_ldr();
1513 
1514 #ifdef CONFIG_X86_32
1515 	/*
1516 	 * APIC LDR is initialized.  If logical_apicid mapping was
1517 	 * initialized during get_smp_config(), make sure it matches the
1518 	 * actual value.
1519 	 */
1520 	logical_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
1521 	ldr_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
1522 	WARN_ON(logical_apicid != BAD_APICID && logical_apicid != ldr_apicid);
1523 	/* always use the value from LDR */
1524 	early_per_cpu(x86_cpu_to_logical_apicid, cpu) = ldr_apicid;
1525 #endif
1526 
1527 	/*
1528 	 * Set Task Priority to 'accept all'. We never change this
1529 	 * later on.
1530 	 */
1531 	value = apic_read(APIC_TASKPRI);
1532 	value &= ~APIC_TPRI_MASK;
1533 	apic_write(APIC_TASKPRI, value);
1534 
1535 	apic_pending_intr_clear();
1536 
1537 	/*
1538 	 * Now that we are all set up, enable the APIC
1539 	 */
1540 	value = apic_read(APIC_SPIV);
1541 	value &= ~APIC_VECTOR_MASK;
1542 	/*
1543 	 * Enable APIC
1544 	 */
1545 	value |= APIC_SPIV_APIC_ENABLED;
1546 
1547 #ifdef CONFIG_X86_32
1548 	/*
1549 	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1550 	 * certain networking cards. If high frequency interrupts are
1551 	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1552 	 * entry is masked/unmasked at a high rate as well then sooner or
1553 	 * later IOAPIC line gets 'stuck', no more interrupts are received
1554 	 * from the device. If focus CPU is disabled then the hang goes
1555 	 * away, oh well :-(
1556 	 *
1557 	 * [ This bug can be reproduced easily with a level-triggered
1558 	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1559 	 *   BX chipset. ]
1560 	 */
1561 	/*
1562 	 * Actually disabling the focus CPU check just makes the hang less
1563 	 * frequent as it makes the interrupt distributon model be more
1564 	 * like LRU than MRU (the short-term load is more even across CPUs).
1565 	 */
1566 
1567 	/*
1568 	 * - enable focus processor (bit==0)
1569 	 * - 64bit mode always use processor focus
1570 	 *   so no need to set it
1571 	 */
1572 	value &= ~APIC_SPIV_FOCUS_DISABLED;
1573 #endif
1574 
1575 	/*
1576 	 * Set spurious IRQ vector
1577 	 */
1578 	value |= SPURIOUS_APIC_VECTOR;
1579 	apic_write(APIC_SPIV, value);
1580 
1581 	/*
1582 	 * Set up LVT0, LVT1:
1583 	 *
1584 	 * set up through-local-APIC on the boot CPU's LINT0. This is not
1585 	 * strictly necessary in pure symmetric-IO mode, but sometimes
1586 	 * we delegate interrupts to the 8259A.
1587 	 */
1588 	/*
1589 	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1590 	 */
1591 	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1592 	if (!cpu && (pic_mode || !value || skip_ioapic_setup)) {
1593 		value = APIC_DM_EXTINT;
1594 		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
1595 	} else {
1596 		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1597 		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
1598 	}
1599 	apic_write(APIC_LVT0, value);
1600 
1601 	/*
1602 	 * Only the BSP sees the LINT1 NMI signal by default. This can be
1603 	 * modified by apic_extnmi= boot option.
1604 	 */
1605 	if ((!cpu && apic_extnmi != APIC_EXTNMI_NONE) ||
1606 	    apic_extnmi == APIC_EXTNMI_ALL)
1607 		value = APIC_DM_NMI;
1608 	else
1609 		value = APIC_DM_NMI | APIC_LVT_MASKED;
1610 
1611 	/* Is 82489DX ? */
1612 	if (!lapic_is_integrated())
1613 		value |= APIC_LVT_LEVEL_TRIGGER;
1614 	apic_write(APIC_LVT1, value);
1615 
1616 #ifdef CONFIG_X86_MCE_INTEL
1617 	/* Recheck CMCI information after local APIC is up on CPU #0 */
1618 	if (!cpu)
1619 		cmci_recheck();
1620 #endif
1621 }
1622 
1623 static void end_local_APIC_setup(void)
1624 {
1625 	lapic_setup_esr();
1626 
1627 #ifdef CONFIG_X86_32
1628 	{
1629 		unsigned int value;
1630 		/* Disable the local apic timer */
1631 		value = apic_read(APIC_LVTT);
1632 		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1633 		apic_write(APIC_LVTT, value);
1634 	}
1635 #endif
1636 
1637 	apic_pm_activate();
1638 }
1639 
1640 /*
1641  * APIC setup function for application processors. Called from smpboot.c
1642  */
1643 void apic_ap_setup(void)
1644 {
1645 	setup_local_APIC();
1646 	end_local_APIC_setup();
1647 }
1648 
1649 #ifdef CONFIG_X86_X2APIC
1650 int x2apic_mode;
1651 
1652 enum {
1653 	X2APIC_OFF,
1654 	X2APIC_ON,
1655 	X2APIC_DISABLED,
1656 };
1657 static int x2apic_state;
1658 
1659 static void __x2apic_disable(void)
1660 {
1661 	u64 msr;
1662 
1663 	if (!boot_cpu_has(X86_FEATURE_APIC))
1664 		return;
1665 
1666 	rdmsrl(MSR_IA32_APICBASE, msr);
1667 	if (!(msr & X2APIC_ENABLE))
1668 		return;
1669 	/* Disable xapic and x2apic first and then reenable xapic mode */
1670 	wrmsrl(MSR_IA32_APICBASE, msr & ~(X2APIC_ENABLE | XAPIC_ENABLE));
1671 	wrmsrl(MSR_IA32_APICBASE, msr & ~X2APIC_ENABLE);
1672 	printk_once(KERN_INFO "x2apic disabled\n");
1673 }
1674 
1675 static void __x2apic_enable(void)
1676 {
1677 	u64 msr;
1678 
1679 	rdmsrl(MSR_IA32_APICBASE, msr);
1680 	if (msr & X2APIC_ENABLE)
1681 		return;
1682 	wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE);
1683 	printk_once(KERN_INFO "x2apic enabled\n");
1684 }
1685 
1686 static int __init setup_nox2apic(char *str)
1687 {
1688 	if (x2apic_enabled()) {
1689 		int apicid = native_apic_msr_read(APIC_ID);
1690 
1691 		if (apicid >= 255) {
1692 			pr_warning("Apicid: %08x, cannot enforce nox2apic\n",
1693 				   apicid);
1694 			return 0;
1695 		}
1696 		pr_warning("x2apic already enabled.\n");
1697 		__x2apic_disable();
1698 	}
1699 	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
1700 	x2apic_state = X2APIC_DISABLED;
1701 	x2apic_mode = 0;
1702 	return 0;
1703 }
1704 early_param("nox2apic", setup_nox2apic);
1705 
1706 /* Called from cpu_init() to enable x2apic on (secondary) cpus */
1707 void x2apic_setup(void)
1708 {
1709 	/*
1710 	 * If x2apic is not in ON state, disable it if already enabled
1711 	 * from BIOS.
1712 	 */
1713 	if (x2apic_state != X2APIC_ON) {
1714 		__x2apic_disable();
1715 		return;
1716 	}
1717 	__x2apic_enable();
1718 }
1719 
1720 static __init void x2apic_disable(void)
1721 {
1722 	u32 x2apic_id, state = x2apic_state;
1723 
1724 	x2apic_mode = 0;
1725 	x2apic_state = X2APIC_DISABLED;
1726 
1727 	if (state != X2APIC_ON)
1728 		return;
1729 
1730 	x2apic_id = read_apic_id();
1731 	if (x2apic_id >= 255)
1732 		panic("Cannot disable x2apic, id: %08x\n", x2apic_id);
1733 
1734 	__x2apic_disable();
1735 	register_lapic_address(mp_lapic_addr);
1736 }
1737 
1738 static __init void x2apic_enable(void)
1739 {
1740 	if (x2apic_state != X2APIC_OFF)
1741 		return;
1742 
1743 	x2apic_mode = 1;
1744 	x2apic_state = X2APIC_ON;
1745 	__x2apic_enable();
1746 }
1747 
1748 static __init void try_to_enable_x2apic(int remap_mode)
1749 {
1750 	if (x2apic_state == X2APIC_DISABLED)
1751 		return;
1752 
1753 	if (remap_mode != IRQ_REMAP_X2APIC_MODE) {
1754 		/* IR is required if there is APIC ID > 255 even when running
1755 		 * under KVM
1756 		 */
1757 		if (max_physical_apicid > 255 ||
1758 		    !x86_init.hyper.x2apic_available()) {
1759 			pr_info("x2apic: IRQ remapping doesn't support X2APIC mode\n");
1760 			x2apic_disable();
1761 			return;
1762 		}
1763 
1764 		/*
1765 		 * without IR all CPUs can be addressed by IOAPIC/MSI
1766 		 * only in physical mode
1767 		 */
1768 		x2apic_phys = 1;
1769 	}
1770 	x2apic_enable();
1771 }
1772 
1773 void __init check_x2apic(void)
1774 {
1775 	if (x2apic_enabled()) {
1776 		pr_info("x2apic: enabled by BIOS, switching to x2apic ops\n");
1777 		x2apic_mode = 1;
1778 		x2apic_state = X2APIC_ON;
1779 	} else if (!boot_cpu_has(X86_FEATURE_X2APIC)) {
1780 		x2apic_state = X2APIC_DISABLED;
1781 	}
1782 }
1783 #else /* CONFIG_X86_X2APIC */
1784 static int __init validate_x2apic(void)
1785 {
1786 	if (!apic_is_x2apic_enabled())
1787 		return 0;
1788 	/*
1789 	 * Checkme: Can we simply turn off x2apic here instead of panic?
1790 	 */
1791 	panic("BIOS has enabled x2apic but kernel doesn't support x2apic, please disable x2apic in BIOS.\n");
1792 }
1793 early_initcall(validate_x2apic);
1794 
1795 static inline void try_to_enable_x2apic(int remap_mode) { }
1796 static inline void __x2apic_enable(void) { }
1797 #endif /* !CONFIG_X86_X2APIC */
1798 
1799 void __init enable_IR_x2apic(void)
1800 {
1801 	unsigned long flags;
1802 	int ret, ir_stat;
1803 
1804 	if (skip_ioapic_setup) {
1805 		pr_info("Not enabling interrupt remapping due to skipped IO-APIC setup\n");
1806 		return;
1807 	}
1808 
1809 	ir_stat = irq_remapping_prepare();
1810 	if (ir_stat < 0 && !x2apic_supported())
1811 		return;
1812 
1813 	ret = save_ioapic_entries();
1814 	if (ret) {
1815 		pr_info("Saving IO-APIC state failed: %d\n", ret);
1816 		return;
1817 	}
1818 
1819 	local_irq_save(flags);
1820 	legacy_pic->mask_all();
1821 	mask_ioapic_entries();
1822 
1823 	/* If irq_remapping_prepare() succeeded, try to enable it */
1824 	if (ir_stat >= 0)
1825 		ir_stat = irq_remapping_enable();
1826 	/* ir_stat contains the remap mode or an error code */
1827 	try_to_enable_x2apic(ir_stat);
1828 
1829 	if (ir_stat < 0)
1830 		restore_ioapic_entries();
1831 	legacy_pic->restore_mask();
1832 	local_irq_restore(flags);
1833 }
1834 
1835 #ifdef CONFIG_X86_64
1836 /*
1837  * Detect and enable local APICs on non-SMP boards.
1838  * Original code written by Keir Fraser.
1839  * On AMD64 we trust the BIOS - if it says no APIC it is likely
1840  * not correctly set up (usually the APIC timer won't work etc.)
1841  */
1842 static int __init detect_init_APIC(void)
1843 {
1844 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1845 		pr_info("No local APIC present\n");
1846 		return -1;
1847 	}
1848 
1849 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1850 	return 0;
1851 }
1852 #else
1853 
1854 static int __init apic_verify(void)
1855 {
1856 	u32 features, h, l;
1857 
1858 	/*
1859 	 * The APIC feature bit should now be enabled
1860 	 * in `cpuid'
1861 	 */
1862 	features = cpuid_edx(1);
1863 	if (!(features & (1 << X86_FEATURE_APIC))) {
1864 		pr_warning("Could not enable APIC!\n");
1865 		return -1;
1866 	}
1867 	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1868 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1869 
1870 	/* The BIOS may have set up the APIC at some other address */
1871 	if (boot_cpu_data.x86 >= 6) {
1872 		rdmsr(MSR_IA32_APICBASE, l, h);
1873 		if (l & MSR_IA32_APICBASE_ENABLE)
1874 			mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1875 	}
1876 
1877 	pr_info("Found and enabled local APIC!\n");
1878 	return 0;
1879 }
1880 
1881 int __init apic_force_enable(unsigned long addr)
1882 {
1883 	u32 h, l;
1884 
1885 	if (disable_apic)
1886 		return -1;
1887 
1888 	/*
1889 	 * Some BIOSes disable the local APIC in the APIC_BASE
1890 	 * MSR. This can only be done in software for Intel P6 or later
1891 	 * and AMD K7 (Model > 1) or later.
1892 	 */
1893 	if (boot_cpu_data.x86 >= 6) {
1894 		rdmsr(MSR_IA32_APICBASE, l, h);
1895 		if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1896 			pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1897 			l &= ~MSR_IA32_APICBASE_BASE;
1898 			l |= MSR_IA32_APICBASE_ENABLE | addr;
1899 			wrmsr(MSR_IA32_APICBASE, l, h);
1900 			enabled_via_apicbase = 1;
1901 		}
1902 	}
1903 	return apic_verify();
1904 }
1905 
1906 /*
1907  * Detect and initialize APIC
1908  */
1909 static int __init detect_init_APIC(void)
1910 {
1911 	/* Disabled by kernel option? */
1912 	if (disable_apic)
1913 		return -1;
1914 
1915 	switch (boot_cpu_data.x86_vendor) {
1916 	case X86_VENDOR_AMD:
1917 		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1918 		    (boot_cpu_data.x86 >= 15))
1919 			break;
1920 		goto no_apic;
1921 	case X86_VENDOR_HYGON:
1922 		break;
1923 	case X86_VENDOR_INTEL:
1924 		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1925 		    (boot_cpu_data.x86 == 5 && boot_cpu_has(X86_FEATURE_APIC)))
1926 			break;
1927 		goto no_apic;
1928 	default:
1929 		goto no_apic;
1930 	}
1931 
1932 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1933 		/*
1934 		 * Over-ride BIOS and try to enable the local APIC only if
1935 		 * "lapic" specified.
1936 		 */
1937 		if (!force_enable_local_apic) {
1938 			pr_info("Local APIC disabled by BIOS -- "
1939 				"you can enable it with \"lapic\"\n");
1940 			return -1;
1941 		}
1942 		if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
1943 			return -1;
1944 	} else {
1945 		if (apic_verify())
1946 			return -1;
1947 	}
1948 
1949 	apic_pm_activate();
1950 
1951 	return 0;
1952 
1953 no_apic:
1954 	pr_info("No local APIC present or hardware disabled\n");
1955 	return -1;
1956 }
1957 #endif
1958 
1959 /**
1960  * init_apic_mappings - initialize APIC mappings
1961  */
1962 void __init init_apic_mappings(void)
1963 {
1964 	unsigned int new_apicid;
1965 
1966 	apic_check_deadline_errata();
1967 
1968 	if (x2apic_mode) {
1969 		boot_cpu_physical_apicid = read_apic_id();
1970 		return;
1971 	}
1972 
1973 	/* If no local APIC can be found return early */
1974 	if (!smp_found_config && detect_init_APIC()) {
1975 		/* lets NOP'ify apic operations */
1976 		pr_info("APIC: disable apic facility\n");
1977 		apic_disable();
1978 	} else {
1979 		apic_phys = mp_lapic_addr;
1980 
1981 		/*
1982 		 * If the system has ACPI MADT tables or MP info, the LAPIC
1983 		 * address is already registered.
1984 		 */
1985 		if (!acpi_lapic && !smp_found_config)
1986 			register_lapic_address(apic_phys);
1987 	}
1988 
1989 	/*
1990 	 * Fetch the APIC ID of the BSP in case we have a
1991 	 * default configuration (or the MP table is broken).
1992 	 */
1993 	new_apicid = read_apic_id();
1994 	if (boot_cpu_physical_apicid != new_apicid) {
1995 		boot_cpu_physical_apicid = new_apicid;
1996 		/*
1997 		 * yeah -- we lie about apic_version
1998 		 * in case if apic was disabled via boot option
1999 		 * but it's not a problem for SMP compiled kernel
2000 		 * since apic_intr_mode_select is prepared for such
2001 		 * a case and disable smp mode
2002 		 */
2003 		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
2004 	}
2005 }
2006 
2007 void __init register_lapic_address(unsigned long address)
2008 {
2009 	mp_lapic_addr = address;
2010 
2011 	if (!x2apic_mode) {
2012 		set_fixmap_nocache(FIX_APIC_BASE, address);
2013 		apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
2014 			    APIC_BASE, address);
2015 	}
2016 	if (boot_cpu_physical_apicid == -1U) {
2017 		boot_cpu_physical_apicid  = read_apic_id();
2018 		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
2019 	}
2020 }
2021 
2022 /*
2023  * Local APIC interrupts
2024  */
2025 
2026 /*
2027  * This interrupt should _never_ happen with our APIC/SMP architecture
2028  */
2029 __visible void __irq_entry smp_spurious_interrupt(struct pt_regs *regs)
2030 {
2031 	u8 vector = ~regs->orig_ax;
2032 	u32 v;
2033 
2034 	entering_irq();
2035 	trace_spurious_apic_entry(vector);
2036 
2037 	/*
2038 	 * Check if this really is a spurious interrupt and ACK it
2039 	 * if it is a vectored one.  Just in case...
2040 	 * Spurious interrupts should not be ACKed.
2041 	 */
2042 	v = apic_read(APIC_ISR + ((vector & ~0x1f) >> 1));
2043 	if (v & (1 << (vector & 0x1f)))
2044 		ack_APIC_irq();
2045 
2046 	inc_irq_stat(irq_spurious_count);
2047 
2048 	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
2049 	pr_info("spurious APIC interrupt through vector %02x on CPU#%d, "
2050 		"should never happen.\n", vector, smp_processor_id());
2051 
2052 	trace_spurious_apic_exit(vector);
2053 	exiting_irq();
2054 }
2055 
2056 /*
2057  * This interrupt should never happen with our APIC/SMP architecture
2058  */
2059 __visible void __irq_entry smp_error_interrupt(struct pt_regs *regs)
2060 {
2061 	static const char * const error_interrupt_reason[] = {
2062 		"Send CS error",		/* APIC Error Bit 0 */
2063 		"Receive CS error",		/* APIC Error Bit 1 */
2064 		"Send accept error",		/* APIC Error Bit 2 */
2065 		"Receive accept error",		/* APIC Error Bit 3 */
2066 		"Redirectable IPI",		/* APIC Error Bit 4 */
2067 		"Send illegal vector",		/* APIC Error Bit 5 */
2068 		"Received illegal vector",	/* APIC Error Bit 6 */
2069 		"Illegal register address",	/* APIC Error Bit 7 */
2070 	};
2071 	u32 v, i = 0;
2072 
2073 	entering_irq();
2074 	trace_error_apic_entry(ERROR_APIC_VECTOR);
2075 
2076 	/* First tickle the hardware, only then report what went on. -- REW */
2077 	if (lapic_get_maxlvt() > 3)	/* Due to the Pentium erratum 3AP. */
2078 		apic_write(APIC_ESR, 0);
2079 	v = apic_read(APIC_ESR);
2080 	ack_APIC_irq();
2081 	atomic_inc(&irq_err_count);
2082 
2083 	apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x",
2084 		    smp_processor_id(), v);
2085 
2086 	v &= 0xff;
2087 	while (v) {
2088 		if (v & 0x1)
2089 			apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
2090 		i++;
2091 		v >>= 1;
2092 	}
2093 
2094 	apic_printk(APIC_DEBUG, KERN_CONT "\n");
2095 
2096 	trace_error_apic_exit(ERROR_APIC_VECTOR);
2097 	exiting_irq();
2098 }
2099 
2100 /**
2101  * connect_bsp_APIC - attach the APIC to the interrupt system
2102  */
2103 static void __init connect_bsp_APIC(void)
2104 {
2105 #ifdef CONFIG_X86_32
2106 	if (pic_mode) {
2107 		/*
2108 		 * Do not trust the local APIC being empty at bootup.
2109 		 */
2110 		clear_local_APIC();
2111 		/*
2112 		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
2113 		 * local APIC to INT and NMI lines.
2114 		 */
2115 		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
2116 				"enabling APIC mode.\n");
2117 		imcr_pic_to_apic();
2118 	}
2119 #endif
2120 }
2121 
2122 /**
2123  * disconnect_bsp_APIC - detach the APIC from the interrupt system
2124  * @virt_wire_setup:	indicates, whether virtual wire mode is selected
2125  *
2126  * Virtual wire mode is necessary to deliver legacy interrupts even when the
2127  * APIC is disabled.
2128  */
2129 void disconnect_bsp_APIC(int virt_wire_setup)
2130 {
2131 	unsigned int value;
2132 
2133 #ifdef CONFIG_X86_32
2134 	if (pic_mode) {
2135 		/*
2136 		 * Put the board back into PIC mode (has an effect only on
2137 		 * certain older boards).  Note that APIC interrupts, including
2138 		 * IPIs, won't work beyond this point!  The only exception are
2139 		 * INIT IPIs.
2140 		 */
2141 		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
2142 				"entering PIC mode.\n");
2143 		imcr_apic_to_pic();
2144 		return;
2145 	}
2146 #endif
2147 
2148 	/* Go back to Virtual Wire compatibility mode */
2149 
2150 	/* For the spurious interrupt use vector F, and enable it */
2151 	value = apic_read(APIC_SPIV);
2152 	value &= ~APIC_VECTOR_MASK;
2153 	value |= APIC_SPIV_APIC_ENABLED;
2154 	value |= 0xf;
2155 	apic_write(APIC_SPIV, value);
2156 
2157 	if (!virt_wire_setup) {
2158 		/*
2159 		 * For LVT0 make it edge triggered, active high,
2160 		 * external and enabled
2161 		 */
2162 		value = apic_read(APIC_LVT0);
2163 		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2164 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2165 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2166 		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2167 		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
2168 		apic_write(APIC_LVT0, value);
2169 	} else {
2170 		/* Disable LVT0 */
2171 		apic_write(APIC_LVT0, APIC_LVT_MASKED);
2172 	}
2173 
2174 	/*
2175 	 * For LVT1 make it edge triggered, active high,
2176 	 * nmi and enabled
2177 	 */
2178 	value = apic_read(APIC_LVT1);
2179 	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2180 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2181 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2182 	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2183 	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
2184 	apic_write(APIC_LVT1, value);
2185 }
2186 
2187 /*
2188  * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
2189  * contiguously, it equals to current allocated max logical CPU ID plus 1.
2190  * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
2191  * so the maximum of nr_logical_cpuids is nr_cpu_ids.
2192  *
2193  * NOTE: Reserve 0 for BSP.
2194  */
2195 static int nr_logical_cpuids = 1;
2196 
2197 /*
2198  * Used to store mapping between logical CPU IDs and APIC IDs.
2199  */
2200 static int cpuid_to_apicid[] = {
2201 	[0 ... NR_CPUS - 1] = -1,
2202 };
2203 
2204 #ifdef CONFIG_SMP
2205 /**
2206  * apic_id_is_primary_thread - Check whether APIC ID belongs to a primary thread
2207  * @id:	APIC ID to check
2208  */
2209 bool apic_id_is_primary_thread(unsigned int apicid)
2210 {
2211 	u32 mask;
2212 
2213 	if (smp_num_siblings == 1)
2214 		return true;
2215 	/* Isolate the SMT bit(s) in the APICID and check for 0 */
2216 	mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
2217 	return !(apicid & mask);
2218 }
2219 #endif
2220 
2221 /*
2222  * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
2223  * and cpuid_to_apicid[] synchronized.
2224  */
2225 static int allocate_logical_cpuid(int apicid)
2226 {
2227 	int i;
2228 
2229 	/*
2230 	 * cpuid <-> apicid mapping is persistent, so when a cpu is up,
2231 	 * check if the kernel has allocated a cpuid for it.
2232 	 */
2233 	for (i = 0; i < nr_logical_cpuids; i++) {
2234 		if (cpuid_to_apicid[i] == apicid)
2235 			return i;
2236 	}
2237 
2238 	/* Allocate a new cpuid. */
2239 	if (nr_logical_cpuids >= nr_cpu_ids) {
2240 		WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
2241 			     "Processor %d/0x%x and the rest are ignored.\n",
2242 			     nr_cpu_ids, nr_logical_cpuids, apicid);
2243 		return -EINVAL;
2244 	}
2245 
2246 	cpuid_to_apicid[nr_logical_cpuids] = apicid;
2247 	return nr_logical_cpuids++;
2248 }
2249 
2250 int generic_processor_info(int apicid, int version)
2251 {
2252 	int cpu, max = nr_cpu_ids;
2253 	bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
2254 				phys_cpu_present_map);
2255 
2256 	/*
2257 	 * boot_cpu_physical_apicid is designed to have the apicid
2258 	 * returned by read_apic_id(), i.e, the apicid of the
2259 	 * currently booting-up processor. However, on some platforms,
2260 	 * it is temporarily modified by the apicid reported as BSP
2261 	 * through MP table. Concretely:
2262 	 *
2263 	 * - arch/x86/kernel/mpparse.c: MP_processor_info()
2264 	 * - arch/x86/mm/amdtopology.c: amd_numa_init()
2265 	 *
2266 	 * This function is executed with the modified
2267 	 * boot_cpu_physical_apicid. So, disabled_cpu_apicid kernel
2268 	 * parameter doesn't work to disable APs on kdump 2nd kernel.
2269 	 *
2270 	 * Since fixing handling of boot_cpu_physical_apicid requires
2271 	 * another discussion and tests on each platform, we leave it
2272 	 * for now and here we use read_apic_id() directly in this
2273 	 * function, generic_processor_info().
2274 	 */
2275 	if (disabled_cpu_apicid != BAD_APICID &&
2276 	    disabled_cpu_apicid != read_apic_id() &&
2277 	    disabled_cpu_apicid == apicid) {
2278 		int thiscpu = num_processors + disabled_cpus;
2279 
2280 		pr_warning("APIC: Disabling requested cpu."
2281 			   " Processor %d/0x%x ignored.\n",
2282 			   thiscpu, apicid);
2283 
2284 		disabled_cpus++;
2285 		return -ENODEV;
2286 	}
2287 
2288 	/*
2289 	 * If boot cpu has not been detected yet, then only allow upto
2290 	 * nr_cpu_ids - 1 processors and keep one slot free for boot cpu
2291 	 */
2292 	if (!boot_cpu_detected && num_processors >= nr_cpu_ids - 1 &&
2293 	    apicid != boot_cpu_physical_apicid) {
2294 		int thiscpu = max + disabled_cpus - 1;
2295 
2296 		pr_warning(
2297 			"APIC: NR_CPUS/possible_cpus limit of %i almost"
2298 			" reached. Keeping one slot for boot cpu."
2299 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
2300 
2301 		disabled_cpus++;
2302 		return -ENODEV;
2303 	}
2304 
2305 	if (num_processors >= nr_cpu_ids) {
2306 		int thiscpu = max + disabled_cpus;
2307 
2308 		pr_warning("APIC: NR_CPUS/possible_cpus limit of %i "
2309 			   "reached. Processor %d/0x%x ignored.\n",
2310 			   max, thiscpu, apicid);
2311 
2312 		disabled_cpus++;
2313 		return -EINVAL;
2314 	}
2315 
2316 	if (apicid == boot_cpu_physical_apicid) {
2317 		/*
2318 		 * x86_bios_cpu_apicid is required to have processors listed
2319 		 * in same order as logical cpu numbers. Hence the first
2320 		 * entry is BSP, and so on.
2321 		 * boot_cpu_init() already hold bit 0 in cpu_present_mask
2322 		 * for BSP.
2323 		 */
2324 		cpu = 0;
2325 
2326 		/* Logical cpuid 0 is reserved for BSP. */
2327 		cpuid_to_apicid[0] = apicid;
2328 	} else {
2329 		cpu = allocate_logical_cpuid(apicid);
2330 		if (cpu < 0) {
2331 			disabled_cpus++;
2332 			return -EINVAL;
2333 		}
2334 	}
2335 
2336 	/*
2337 	 * Validate version
2338 	 */
2339 	if (version == 0x0) {
2340 		pr_warning("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
2341 			   cpu, apicid);
2342 		version = 0x10;
2343 	}
2344 
2345 	if (version != boot_cpu_apic_version) {
2346 		pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
2347 			boot_cpu_apic_version, cpu, version);
2348 	}
2349 
2350 	if (apicid > max_physical_apicid)
2351 		max_physical_apicid = apicid;
2352 
2353 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
2354 	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
2355 	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
2356 #endif
2357 #ifdef CONFIG_X86_32
2358 	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
2359 		apic->x86_32_early_logical_apicid(cpu);
2360 #endif
2361 	set_cpu_possible(cpu, true);
2362 	physid_set(apicid, phys_cpu_present_map);
2363 	set_cpu_present(cpu, true);
2364 	num_processors++;
2365 
2366 	return cpu;
2367 }
2368 
2369 int hard_smp_processor_id(void)
2370 {
2371 	return read_apic_id();
2372 }
2373 
2374 /*
2375  * Override the generic EOI implementation with an optimized version.
2376  * Only called during early boot when only one CPU is active and with
2377  * interrupts disabled, so we know this does not race with actual APIC driver
2378  * use.
2379  */
2380 void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v))
2381 {
2382 	struct apic **drv;
2383 
2384 	for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
2385 		/* Should happen once for each apic */
2386 		WARN_ON((*drv)->eoi_write == eoi_write);
2387 		(*drv)->native_eoi_write = (*drv)->eoi_write;
2388 		(*drv)->eoi_write = eoi_write;
2389 	}
2390 }
2391 
2392 static void __init apic_bsp_up_setup(void)
2393 {
2394 #ifdef CONFIG_X86_64
2395 	apic_write(APIC_ID, apic->set_apic_id(boot_cpu_physical_apicid));
2396 #else
2397 	/*
2398 	 * Hack: In case of kdump, after a crash, kernel might be booting
2399 	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
2400 	 * might be zero if read from MP tables. Get it from LAPIC.
2401 	 */
2402 # ifdef CONFIG_CRASH_DUMP
2403 	boot_cpu_physical_apicid = read_apic_id();
2404 # endif
2405 #endif
2406 	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
2407 }
2408 
2409 /**
2410  * apic_bsp_setup - Setup function for local apic and io-apic
2411  * @upmode:		Force UP mode (for APIC_init_uniprocessor)
2412  *
2413  * Returns:
2414  * apic_id of BSP APIC
2415  */
2416 void __init apic_bsp_setup(bool upmode)
2417 {
2418 	connect_bsp_APIC();
2419 	if (upmode)
2420 		apic_bsp_up_setup();
2421 	setup_local_APIC();
2422 
2423 	enable_IO_APIC();
2424 	end_local_APIC_setup();
2425 	irq_remap_enable_fault_handling();
2426 	setup_IO_APIC();
2427 }
2428 
2429 #ifdef CONFIG_UP_LATE_INIT
2430 void __init up_late_init(void)
2431 {
2432 	if (apic_intr_mode == APIC_PIC)
2433 		return;
2434 
2435 	/* Setup local timer */
2436 	x86_init.timers.setup_percpu_clockev();
2437 }
2438 #endif
2439 
2440 /*
2441  * Power management
2442  */
2443 #ifdef CONFIG_PM
2444 
2445 static struct {
2446 	/*
2447 	 * 'active' is true if the local APIC was enabled by us and
2448 	 * not the BIOS; this signifies that we are also responsible
2449 	 * for disabling it before entering apm/acpi suspend
2450 	 */
2451 	int active;
2452 	/* r/w apic fields */
2453 	unsigned int apic_id;
2454 	unsigned int apic_taskpri;
2455 	unsigned int apic_ldr;
2456 	unsigned int apic_dfr;
2457 	unsigned int apic_spiv;
2458 	unsigned int apic_lvtt;
2459 	unsigned int apic_lvtpc;
2460 	unsigned int apic_lvt0;
2461 	unsigned int apic_lvt1;
2462 	unsigned int apic_lvterr;
2463 	unsigned int apic_tmict;
2464 	unsigned int apic_tdcr;
2465 	unsigned int apic_thmr;
2466 	unsigned int apic_cmci;
2467 } apic_pm_state;
2468 
2469 static int lapic_suspend(void)
2470 {
2471 	unsigned long flags;
2472 	int maxlvt;
2473 
2474 	if (!apic_pm_state.active)
2475 		return 0;
2476 
2477 	maxlvt = lapic_get_maxlvt();
2478 
2479 	apic_pm_state.apic_id = apic_read(APIC_ID);
2480 	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2481 	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2482 	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2483 	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2484 	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2485 	if (maxlvt >= 4)
2486 		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2487 	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2488 	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2489 	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2490 	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2491 	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2492 #ifdef CONFIG_X86_THERMAL_VECTOR
2493 	if (maxlvt >= 5)
2494 		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2495 #endif
2496 #ifdef CONFIG_X86_MCE_INTEL
2497 	if (maxlvt >= 6)
2498 		apic_pm_state.apic_cmci = apic_read(APIC_LVTCMCI);
2499 #endif
2500 
2501 	local_irq_save(flags);
2502 	disable_local_APIC();
2503 
2504 	irq_remapping_disable();
2505 
2506 	local_irq_restore(flags);
2507 	return 0;
2508 }
2509 
2510 static void lapic_resume(void)
2511 {
2512 	unsigned int l, h;
2513 	unsigned long flags;
2514 	int maxlvt;
2515 
2516 	if (!apic_pm_state.active)
2517 		return;
2518 
2519 	local_irq_save(flags);
2520 
2521 	/*
2522 	 * IO-APIC and PIC have their own resume routines.
2523 	 * We just mask them here to make sure the interrupt
2524 	 * subsystem is completely quiet while we enable x2apic
2525 	 * and interrupt-remapping.
2526 	 */
2527 	mask_ioapic_entries();
2528 	legacy_pic->mask_all();
2529 
2530 	if (x2apic_mode) {
2531 		__x2apic_enable();
2532 	} else {
2533 		/*
2534 		 * Make sure the APICBASE points to the right address
2535 		 *
2536 		 * FIXME! This will be wrong if we ever support suspend on
2537 		 * SMP! We'll need to do this as part of the CPU restore!
2538 		 */
2539 		if (boot_cpu_data.x86 >= 6) {
2540 			rdmsr(MSR_IA32_APICBASE, l, h);
2541 			l &= ~MSR_IA32_APICBASE_BASE;
2542 			l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2543 			wrmsr(MSR_IA32_APICBASE, l, h);
2544 		}
2545 	}
2546 
2547 	maxlvt = lapic_get_maxlvt();
2548 	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2549 	apic_write(APIC_ID, apic_pm_state.apic_id);
2550 	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2551 	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2552 	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2553 	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2554 	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2555 	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2556 #ifdef CONFIG_X86_THERMAL_VECTOR
2557 	if (maxlvt >= 5)
2558 		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2559 #endif
2560 #ifdef CONFIG_X86_MCE_INTEL
2561 	if (maxlvt >= 6)
2562 		apic_write(APIC_LVTCMCI, apic_pm_state.apic_cmci);
2563 #endif
2564 	if (maxlvt >= 4)
2565 		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2566 	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2567 	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2568 	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2569 	apic_write(APIC_ESR, 0);
2570 	apic_read(APIC_ESR);
2571 	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2572 	apic_write(APIC_ESR, 0);
2573 	apic_read(APIC_ESR);
2574 
2575 	irq_remapping_reenable(x2apic_mode);
2576 
2577 	local_irq_restore(flags);
2578 }
2579 
2580 /*
2581  * This device has no shutdown method - fully functioning local APICs
2582  * are needed on every CPU up until machine_halt/restart/poweroff.
2583  */
2584 
2585 static struct syscore_ops lapic_syscore_ops = {
2586 	.resume		= lapic_resume,
2587 	.suspend	= lapic_suspend,
2588 };
2589 
2590 static void apic_pm_activate(void)
2591 {
2592 	apic_pm_state.active = 1;
2593 }
2594 
2595 static int __init init_lapic_sysfs(void)
2596 {
2597 	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2598 	if (boot_cpu_has(X86_FEATURE_APIC))
2599 		register_syscore_ops(&lapic_syscore_ops);
2600 
2601 	return 0;
2602 }
2603 
2604 /* local apic needs to resume before other devices access its registers. */
2605 core_initcall(init_lapic_sysfs);
2606 
2607 #else	/* CONFIG_PM */
2608 
2609 static void apic_pm_activate(void) { }
2610 
2611 #endif	/* CONFIG_PM */
2612 
2613 #ifdef CONFIG_X86_64
2614 
2615 static int multi_checked;
2616 static int multi;
2617 
2618 static int set_multi(const struct dmi_system_id *d)
2619 {
2620 	if (multi)
2621 		return 0;
2622 	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2623 	multi = 1;
2624 	return 0;
2625 }
2626 
2627 static const struct dmi_system_id multi_dmi_table[] = {
2628 	{
2629 		.callback = set_multi,
2630 		.ident = "IBM System Summit2",
2631 		.matches = {
2632 			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2633 			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2634 		},
2635 	},
2636 	{}
2637 };
2638 
2639 static void dmi_check_multi(void)
2640 {
2641 	if (multi_checked)
2642 		return;
2643 
2644 	dmi_check_system(multi_dmi_table);
2645 	multi_checked = 1;
2646 }
2647 
2648 /*
2649  * apic_is_clustered_box() -- Check if we can expect good TSC
2650  *
2651  * Thus far, the major user of this is IBM's Summit2 series:
2652  * Clustered boxes may have unsynced TSC problems if they are
2653  * multi-chassis.
2654  * Use DMI to check them
2655  */
2656 int apic_is_clustered_box(void)
2657 {
2658 	dmi_check_multi();
2659 	return multi;
2660 }
2661 #endif
2662 
2663 /*
2664  * APIC command line parameters
2665  */
2666 static int __init setup_disableapic(char *arg)
2667 {
2668 	disable_apic = 1;
2669 	setup_clear_cpu_cap(X86_FEATURE_APIC);
2670 	return 0;
2671 }
2672 early_param("disableapic", setup_disableapic);
2673 
2674 /* same as disableapic, for compatibility */
2675 static int __init setup_nolapic(char *arg)
2676 {
2677 	return setup_disableapic(arg);
2678 }
2679 early_param("nolapic", setup_nolapic);
2680 
2681 static int __init parse_lapic_timer_c2_ok(char *arg)
2682 {
2683 	local_apic_timer_c2_ok = 1;
2684 	return 0;
2685 }
2686 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2687 
2688 static int __init parse_disable_apic_timer(char *arg)
2689 {
2690 	disable_apic_timer = 1;
2691 	return 0;
2692 }
2693 early_param("noapictimer", parse_disable_apic_timer);
2694 
2695 static int __init parse_nolapic_timer(char *arg)
2696 {
2697 	disable_apic_timer = 1;
2698 	return 0;
2699 }
2700 early_param("nolapic_timer", parse_nolapic_timer);
2701 
2702 static int __init apic_set_verbosity(char *arg)
2703 {
2704 	if (!arg)  {
2705 #ifdef CONFIG_X86_64
2706 		skip_ioapic_setup = 0;
2707 		return 0;
2708 #endif
2709 		return -EINVAL;
2710 	}
2711 
2712 	if (strcmp("debug", arg) == 0)
2713 		apic_verbosity = APIC_DEBUG;
2714 	else if (strcmp("verbose", arg) == 0)
2715 		apic_verbosity = APIC_VERBOSE;
2716 #ifdef CONFIG_X86_64
2717 	else {
2718 		pr_warning("APIC Verbosity level %s not recognised"
2719 			" use apic=verbose or apic=debug\n", arg);
2720 		return -EINVAL;
2721 	}
2722 #endif
2723 
2724 	return 0;
2725 }
2726 early_param("apic", apic_set_verbosity);
2727 
2728 static int __init lapic_insert_resource(void)
2729 {
2730 	if (!apic_phys)
2731 		return -1;
2732 
2733 	/* Put local APIC into the resource map. */
2734 	lapic_resource.start = apic_phys;
2735 	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2736 	insert_resource(&iomem_resource, &lapic_resource);
2737 
2738 	return 0;
2739 }
2740 
2741 /*
2742  * need call insert after e820__reserve_resources()
2743  * that is using request_resource
2744  */
2745 late_initcall(lapic_insert_resource);
2746 
2747 static int __init apic_set_disabled_cpu_apicid(char *arg)
2748 {
2749 	if (!arg || !get_option(&arg, &disabled_cpu_apicid))
2750 		return -EINVAL;
2751 
2752 	return 0;
2753 }
2754 early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);
2755 
2756 static int __init apic_set_extnmi(char *arg)
2757 {
2758 	if (!arg)
2759 		return -EINVAL;
2760 
2761 	if (!strncmp("all", arg, 3))
2762 		apic_extnmi = APIC_EXTNMI_ALL;
2763 	else if (!strncmp("none", arg, 4))
2764 		apic_extnmi = APIC_EXTNMI_NONE;
2765 	else if (!strncmp("bsp", arg, 3))
2766 		apic_extnmi = APIC_EXTNMI_BSP;
2767 	else {
2768 		pr_warn("Unknown external NMI delivery mode `%s' ignored\n", arg);
2769 		return -EINVAL;
2770 	}
2771 
2772 	return 0;
2773 }
2774 early_param("apic_extnmi", apic_set_extnmi);
2775