xref: /openbmc/linux/arch/x86/kernel/apic/apic.c (revision b9b77222)
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/bootmem.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 
60 unsigned int num_processors;
61 
62 unsigned disabled_cpus;
63 
64 /* Processor that is doing the boot up */
65 unsigned int boot_cpu_physical_apicid = -1U;
66 EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
67 
68 u8 boot_cpu_apic_version;
69 
70 /*
71  * The highest APIC ID seen during enumeration.
72  */
73 static unsigned int max_physical_apicid;
74 
75 /*
76  * Bitmask of physically existing CPUs:
77  */
78 physid_mask_t phys_cpu_present_map;
79 
80 /*
81  * Processor to be disabled specified by kernel parameter
82  * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
83  * avoid undefined behaviour caused by sending INIT from AP to BSP.
84  */
85 static unsigned int disabled_cpu_apicid __read_mostly = BAD_APICID;
86 
87 /*
88  * This variable controls which CPUs receive external NMIs.  By default,
89  * external NMIs are delivered only to the BSP.
90  */
91 static int apic_extnmi = APIC_EXTNMI_BSP;
92 
93 /*
94  * Map cpu index to physical APIC ID
95  */
96 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid, BAD_APICID);
97 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_bios_cpu_apicid, BAD_APICID);
98 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, U32_MAX);
99 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
100 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
101 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
102 
103 #ifdef CONFIG_X86_32
104 
105 /*
106  * On x86_32, the mapping between cpu and logical apicid may vary
107  * depending on apic in use.  The following early percpu variable is
108  * used for the mapping.  This is where the behaviors of x86_64 and 32
109  * actually diverge.  Let's keep it ugly for now.
110  */
111 DEFINE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid, BAD_APICID);
112 
113 /* Local APIC was disabled by the BIOS and enabled by the kernel */
114 static int enabled_via_apicbase;
115 
116 /*
117  * Handle interrupt mode configuration register (IMCR).
118  * This register controls whether the interrupt signals
119  * that reach the BSP come from the master PIC or from the
120  * local APIC. Before entering Symmetric I/O Mode, either
121  * the BIOS or the operating system must switch out of
122  * PIC Mode by changing the IMCR.
123  */
124 static inline void imcr_pic_to_apic(void)
125 {
126 	/* select IMCR register */
127 	outb(0x70, 0x22);
128 	/* NMI and 8259 INTR go through APIC */
129 	outb(0x01, 0x23);
130 }
131 
132 static inline void imcr_apic_to_pic(void)
133 {
134 	/* select IMCR register */
135 	outb(0x70, 0x22);
136 	/* NMI and 8259 INTR go directly to BSP */
137 	outb(0x00, 0x23);
138 }
139 #endif
140 
141 /*
142  * Knob to control our willingness to enable the local APIC.
143  *
144  * +1=force-enable
145  */
146 static int force_enable_local_apic __initdata;
147 
148 /*
149  * APIC command line parameters
150  */
151 static int __init parse_lapic(char *arg)
152 {
153 	if (IS_ENABLED(CONFIG_X86_32) && !arg)
154 		force_enable_local_apic = 1;
155 	else if (arg && !strncmp(arg, "notscdeadline", 13))
156 		setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
157 	return 0;
158 }
159 early_param("lapic", parse_lapic);
160 
161 #ifdef CONFIG_X86_64
162 static int apic_calibrate_pmtmr __initdata;
163 static __init int setup_apicpmtimer(char *s)
164 {
165 	apic_calibrate_pmtmr = 1;
166 	notsc_setup(NULL);
167 	return 0;
168 }
169 __setup("apicpmtimer", setup_apicpmtimer);
170 #endif
171 
172 unsigned long mp_lapic_addr;
173 int disable_apic;
174 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
175 static int disable_apic_timer __initdata;
176 /* Local APIC timer works in C2 */
177 int local_apic_timer_c2_ok;
178 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
179 
180 /*
181  * Debug level, exported for io_apic.c
182  */
183 unsigned int apic_verbosity;
184 
185 int pic_mode;
186 
187 /* Have we found an MP table */
188 int smp_found_config;
189 
190 static struct resource lapic_resource = {
191 	.name = "Local APIC",
192 	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
193 };
194 
195 unsigned int lapic_timer_frequency = 0;
196 
197 static void apic_pm_activate(void);
198 
199 static unsigned long apic_phys;
200 
201 /*
202  * Get the LAPIC version
203  */
204 static inline int lapic_get_version(void)
205 {
206 	return GET_APIC_VERSION(apic_read(APIC_LVR));
207 }
208 
209 /*
210  * Check, if the APIC is integrated or a separate chip
211  */
212 static inline int lapic_is_integrated(void)
213 {
214 	return APIC_INTEGRATED(lapic_get_version());
215 }
216 
217 /*
218  * Check, whether this is a modern or a first generation APIC
219  */
220 static int modern_apic(void)
221 {
222 	/* AMD systems use old APIC versions, so check the CPU */
223 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
224 	    boot_cpu_data.x86 >= 0xf)
225 		return 1;
226 	return lapic_get_version() >= 0x14;
227 }
228 
229 /*
230  * right after this call apic become NOOP driven
231  * so apic->write/read doesn't do anything
232  */
233 static void __init apic_disable(void)
234 {
235 	pr_info("APIC: switched to apic NOOP\n");
236 	apic = &apic_noop;
237 }
238 
239 void native_apic_wait_icr_idle(void)
240 {
241 	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
242 		cpu_relax();
243 }
244 
245 u32 native_safe_apic_wait_icr_idle(void)
246 {
247 	u32 send_status;
248 	int timeout;
249 
250 	timeout = 0;
251 	do {
252 		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
253 		if (!send_status)
254 			break;
255 		inc_irq_stat(icr_read_retry_count);
256 		udelay(100);
257 	} while (timeout++ < 1000);
258 
259 	return send_status;
260 }
261 
262 void native_apic_icr_write(u32 low, u32 id)
263 {
264 	unsigned long flags;
265 
266 	local_irq_save(flags);
267 	apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
268 	apic_write(APIC_ICR, low);
269 	local_irq_restore(flags);
270 }
271 
272 u64 native_apic_icr_read(void)
273 {
274 	u32 icr1, icr2;
275 
276 	icr2 = apic_read(APIC_ICR2);
277 	icr1 = apic_read(APIC_ICR);
278 
279 	return icr1 | ((u64)icr2 << 32);
280 }
281 
282 #ifdef CONFIG_X86_32
283 /**
284  * get_physical_broadcast - Get number of physical broadcast IDs
285  */
286 int get_physical_broadcast(void)
287 {
288 	return modern_apic() ? 0xff : 0xf;
289 }
290 #endif
291 
292 /**
293  * lapic_get_maxlvt - get the maximum number of local vector table entries
294  */
295 int lapic_get_maxlvt(void)
296 {
297 	/*
298 	 * - we always have APIC integrated on 64bit mode
299 	 * - 82489DXs do not report # of LVT entries
300 	 */
301 	return lapic_is_integrated() ? GET_APIC_MAXLVT(apic_read(APIC_LVR)) : 2;
302 }
303 
304 /*
305  * Local APIC timer
306  */
307 
308 /* Clock divisor */
309 #define APIC_DIVISOR 16
310 #define TSC_DIVISOR  8
311 
312 /*
313  * This function sets up the local APIC timer, with a timeout of
314  * 'clocks' APIC bus clock. During calibration we actually call
315  * this function twice on the boot CPU, once with a bogus timeout
316  * value, second time for real. The other (noncalibrating) CPUs
317  * call this function only once, with the real, calibrated value.
318  *
319  * We do reads before writes even if unnecessary, to get around the
320  * P5 APIC double write bug.
321  */
322 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
323 {
324 	unsigned int lvtt_value, tmp_value;
325 
326 	lvtt_value = LOCAL_TIMER_VECTOR;
327 	if (!oneshot)
328 		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
329 	else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
330 		lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE;
331 
332 	if (!lapic_is_integrated())
333 		lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
334 
335 	if (!irqen)
336 		lvtt_value |= APIC_LVT_MASKED;
337 
338 	apic_write(APIC_LVTT, lvtt_value);
339 
340 	if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) {
341 		/*
342 		 * See Intel SDM: TSC-Deadline Mode chapter. In xAPIC mode,
343 		 * writing to the APIC LVTT and TSC_DEADLINE MSR isn't serialized.
344 		 * According to Intel, MFENCE can do the serialization here.
345 		 */
346 		asm volatile("mfence" : : : "memory");
347 
348 		printk_once(KERN_DEBUG "TSC deadline timer enabled\n");
349 		return;
350 	}
351 
352 	/*
353 	 * Divide PICLK by 16
354 	 */
355 	tmp_value = apic_read(APIC_TDCR);
356 	apic_write(APIC_TDCR,
357 		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
358 		APIC_TDR_DIV_16);
359 
360 	if (!oneshot)
361 		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
362 }
363 
364 /*
365  * Setup extended LVT, AMD specific
366  *
367  * Software should use the LVT offsets the BIOS provides.  The offsets
368  * are determined by the subsystems using it like those for MCE
369  * threshold or IBS.  On K8 only offset 0 (APIC500) and MCE interrupts
370  * are supported. Beginning with family 10h at least 4 offsets are
371  * available.
372  *
373  * Since the offsets must be consistent for all cores, we keep track
374  * of the LVT offsets in software and reserve the offset for the same
375  * vector also to be used on other cores. An offset is freed by
376  * setting the entry to APIC_EILVT_MASKED.
377  *
378  * If the BIOS is right, there should be no conflicts. Otherwise a
379  * "[Firmware Bug]: ..." error message is generated. However, if
380  * software does not properly determines the offsets, it is not
381  * necessarily a BIOS bug.
382  */
383 
384 static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
385 
386 static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
387 {
388 	return (old & APIC_EILVT_MASKED)
389 		|| (new == APIC_EILVT_MASKED)
390 		|| ((new & ~APIC_EILVT_MASKED) == old);
391 }
392 
393 static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
394 {
395 	unsigned int rsvd, vector;
396 
397 	if (offset >= APIC_EILVT_NR_MAX)
398 		return ~0;
399 
400 	rsvd = atomic_read(&eilvt_offsets[offset]);
401 	do {
402 		vector = rsvd & ~APIC_EILVT_MASKED;	/* 0: unassigned */
403 		if (vector && !eilvt_entry_is_changeable(vector, new))
404 			/* may not change if vectors are different */
405 			return rsvd;
406 		rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new);
407 	} while (rsvd != new);
408 
409 	rsvd &= ~APIC_EILVT_MASKED;
410 	if (rsvd && rsvd != vector)
411 		pr_info("LVT offset %d assigned for vector 0x%02x\n",
412 			offset, rsvd);
413 
414 	return new;
415 }
416 
417 /*
418  * If mask=1, the LVT entry does not generate interrupts while mask=0
419  * enables the vector. See also the BKDGs. Must be called with
420  * preemption disabled.
421  */
422 
423 int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
424 {
425 	unsigned long reg = APIC_EILVTn(offset);
426 	unsigned int new, old, reserved;
427 
428 	new = (mask << 16) | (msg_type << 8) | vector;
429 	old = apic_read(reg);
430 	reserved = reserve_eilvt_offset(offset, new);
431 
432 	if (reserved != new) {
433 		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
434 		       "vector 0x%x, but the register is already in use for "
435 		       "vector 0x%x on another cpu\n",
436 		       smp_processor_id(), reg, offset, new, reserved);
437 		return -EINVAL;
438 	}
439 
440 	if (!eilvt_entry_is_changeable(old, new)) {
441 		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
442 		       "vector 0x%x, but the register is already in use for "
443 		       "vector 0x%x on this cpu\n",
444 		       smp_processor_id(), reg, offset, new, old);
445 		return -EBUSY;
446 	}
447 
448 	apic_write(reg, new);
449 
450 	return 0;
451 }
452 EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
453 
454 /*
455  * Program the next event, relative to now
456  */
457 static int lapic_next_event(unsigned long delta,
458 			    struct clock_event_device *evt)
459 {
460 	apic_write(APIC_TMICT, delta);
461 	return 0;
462 }
463 
464 static int lapic_next_deadline(unsigned long delta,
465 			       struct clock_event_device *evt)
466 {
467 	u64 tsc;
468 
469 	tsc = rdtsc();
470 	wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR));
471 	return 0;
472 }
473 
474 static int lapic_timer_shutdown(struct clock_event_device *evt)
475 {
476 	unsigned int v;
477 
478 	/* Lapic used as dummy for broadcast ? */
479 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
480 		return 0;
481 
482 	v = apic_read(APIC_LVTT);
483 	v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
484 	apic_write(APIC_LVTT, v);
485 	apic_write(APIC_TMICT, 0);
486 	return 0;
487 }
488 
489 static inline int
490 lapic_timer_set_periodic_oneshot(struct clock_event_device *evt, bool oneshot)
491 {
492 	/* Lapic used as dummy for broadcast ? */
493 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
494 		return 0;
495 
496 	__setup_APIC_LVTT(lapic_timer_frequency, oneshot, 1);
497 	return 0;
498 }
499 
500 static int lapic_timer_set_periodic(struct clock_event_device *evt)
501 {
502 	return lapic_timer_set_periodic_oneshot(evt, false);
503 }
504 
505 static int lapic_timer_set_oneshot(struct clock_event_device *evt)
506 {
507 	return lapic_timer_set_periodic_oneshot(evt, true);
508 }
509 
510 /*
511  * Local APIC timer broadcast function
512  */
513 static void lapic_timer_broadcast(const struct cpumask *mask)
514 {
515 #ifdef CONFIG_SMP
516 	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
517 #endif
518 }
519 
520 
521 /*
522  * The local apic timer can be used for any function which is CPU local.
523  */
524 static struct clock_event_device lapic_clockevent = {
525 	.name				= "lapic",
526 	.features			= CLOCK_EVT_FEAT_PERIODIC |
527 					  CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP
528 					  | CLOCK_EVT_FEAT_DUMMY,
529 	.shift				= 32,
530 	.set_state_shutdown		= lapic_timer_shutdown,
531 	.set_state_periodic		= lapic_timer_set_periodic,
532 	.set_state_oneshot		= lapic_timer_set_oneshot,
533 	.set_state_oneshot_stopped	= lapic_timer_shutdown,
534 	.set_next_event			= lapic_next_event,
535 	.broadcast			= lapic_timer_broadcast,
536 	.rating				= 100,
537 	.irq				= -1,
538 };
539 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
540 
541 #define DEADLINE_MODEL_MATCH_FUNC(model, func)	\
542 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&func }
543 
544 #define DEADLINE_MODEL_MATCH_REV(model, rev)	\
545 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)rev }
546 
547 static u32 hsx_deadline_rev(void)
548 {
549 	switch (boot_cpu_data.x86_stepping) {
550 	case 0x02: return 0x3a; /* EP */
551 	case 0x04: return 0x0f; /* EX */
552 	}
553 
554 	return ~0U;
555 }
556 
557 static u32 bdx_deadline_rev(void)
558 {
559 	switch (boot_cpu_data.x86_stepping) {
560 	case 0x02: return 0x00000011;
561 	case 0x03: return 0x0700000e;
562 	case 0x04: return 0x0f00000c;
563 	case 0x05: return 0x0e000003;
564 	}
565 
566 	return ~0U;
567 }
568 
569 static u32 skx_deadline_rev(void)
570 {
571 	switch (boot_cpu_data.x86_stepping) {
572 	case 0x03: return 0x01000136;
573 	case 0x04: return 0x02000014;
574 	}
575 
576 	if (boot_cpu_data.x86_stepping > 4)
577 		return 0;
578 
579 	return ~0U;
580 }
581 
582 static const struct x86_cpu_id deadline_match[] = {
583 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_HASWELL_X,	hsx_deadline_rev),
584 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_X,	0x0b000020),
585 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_BROADWELL_XEON_D,	bdx_deadline_rev),
586 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_SKYLAKE_X,	skx_deadline_rev),
587 
588 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_CORE,	0x22),
589 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_ULT,	0x20),
590 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_GT3E,	0x17),
591 
592 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_CORE,	0x25),
593 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_GT3E,	0x17),
594 
595 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_MOBILE,	0xb2),
596 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_DESKTOP,	0xb2),
597 
598 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_MOBILE,	0x52),
599 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_DESKTOP,	0x52),
600 
601 	{},
602 };
603 
604 static void apic_check_deadline_errata(void)
605 {
606 	const struct x86_cpu_id *m;
607 	u32 rev;
608 
609 	if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER) ||
610 	    boot_cpu_has(X86_FEATURE_HYPERVISOR))
611 		return;
612 
613 	m = x86_match_cpu(deadline_match);
614 	if (!m)
615 		return;
616 
617 	/*
618 	 * Function pointers will have the MSB set due to address layout,
619 	 * immediate revisions will not.
620 	 */
621 	if ((long)m->driver_data < 0)
622 		rev = ((u32 (*)(void))(m->driver_data))();
623 	else
624 		rev = (u32)m->driver_data;
625 
626 	if (boot_cpu_data.microcode >= rev)
627 		return;
628 
629 	setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
630 	pr_err(FW_BUG "TSC_DEADLINE disabled due to Errata; "
631 	       "please update microcode to version: 0x%x (or later)\n", rev);
632 }
633 
634 /*
635  * Setup the local APIC timer for this CPU. Copy the initialized values
636  * of the boot CPU and register the clock event in the framework.
637  */
638 static void setup_APIC_timer(void)
639 {
640 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
641 
642 	if (this_cpu_has(X86_FEATURE_ARAT)) {
643 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
644 		/* Make LAPIC timer preferrable over percpu HPET */
645 		lapic_clockevent.rating = 150;
646 	}
647 
648 	memcpy(levt, &lapic_clockevent, sizeof(*levt));
649 	levt->cpumask = cpumask_of(smp_processor_id());
650 
651 	if (this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
652 		levt->name = "lapic-deadline";
653 		levt->features &= ~(CLOCK_EVT_FEAT_PERIODIC |
654 				    CLOCK_EVT_FEAT_DUMMY);
655 		levt->set_next_event = lapic_next_deadline;
656 		clockevents_config_and_register(levt,
657 						tsc_khz * (1000 / TSC_DIVISOR),
658 						0xF, ~0UL);
659 	} else
660 		clockevents_register_device(levt);
661 }
662 
663 /*
664  * Install the updated TSC frequency from recalibration at the TSC
665  * deadline clockevent devices.
666  */
667 static void __lapic_update_tsc_freq(void *info)
668 {
669 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
670 
671 	if (!this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
672 		return;
673 
674 	clockevents_update_freq(levt, tsc_khz * (1000 / TSC_DIVISOR));
675 }
676 
677 void lapic_update_tsc_freq(void)
678 {
679 	/*
680 	 * The clockevent device's ->mult and ->shift can both be
681 	 * changed. In order to avoid races, schedule the frequency
682 	 * update code on each CPU.
683 	 */
684 	on_each_cpu(__lapic_update_tsc_freq, NULL, 0);
685 }
686 
687 /*
688  * In this functions we calibrate APIC bus clocks to the external timer.
689  *
690  * We want to do the calibration only once since we want to have local timer
691  * irqs syncron. CPUs connected by the same APIC bus have the very same bus
692  * frequency.
693  *
694  * This was previously done by reading the PIT/HPET and waiting for a wrap
695  * around to find out, that a tick has elapsed. I have a box, where the PIT
696  * readout is broken, so it never gets out of the wait loop again. This was
697  * also reported by others.
698  *
699  * Monitoring the jiffies value is inaccurate and the clockevents
700  * infrastructure allows us to do a simple substitution of the interrupt
701  * handler.
702  *
703  * The calibration routine also uses the pm_timer when possible, as the PIT
704  * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
705  * back to normal later in the boot process).
706  */
707 
708 #define LAPIC_CAL_LOOPS		(HZ/10)
709 
710 static __initdata int lapic_cal_loops = -1;
711 static __initdata long lapic_cal_t1, lapic_cal_t2;
712 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
713 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
714 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
715 
716 /*
717  * Temporary interrupt handler.
718  */
719 static void __init lapic_cal_handler(struct clock_event_device *dev)
720 {
721 	unsigned long long tsc = 0;
722 	long tapic = apic_read(APIC_TMCCT);
723 	unsigned long pm = acpi_pm_read_early();
724 
725 	if (boot_cpu_has(X86_FEATURE_TSC))
726 		tsc = rdtsc();
727 
728 	switch (lapic_cal_loops++) {
729 	case 0:
730 		lapic_cal_t1 = tapic;
731 		lapic_cal_tsc1 = tsc;
732 		lapic_cal_pm1 = pm;
733 		lapic_cal_j1 = jiffies;
734 		break;
735 
736 	case LAPIC_CAL_LOOPS:
737 		lapic_cal_t2 = tapic;
738 		lapic_cal_tsc2 = tsc;
739 		if (pm < lapic_cal_pm1)
740 			pm += ACPI_PM_OVRRUN;
741 		lapic_cal_pm2 = pm;
742 		lapic_cal_j2 = jiffies;
743 		break;
744 	}
745 }
746 
747 static int __init
748 calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
749 {
750 	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
751 	const long pm_thresh = pm_100ms / 100;
752 	unsigned long mult;
753 	u64 res;
754 
755 #ifndef CONFIG_X86_PM_TIMER
756 	return -1;
757 #endif
758 
759 	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
760 
761 	/* Check, if the PM timer is available */
762 	if (!deltapm)
763 		return -1;
764 
765 	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
766 
767 	if (deltapm > (pm_100ms - pm_thresh) &&
768 	    deltapm < (pm_100ms + pm_thresh)) {
769 		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
770 		return 0;
771 	}
772 
773 	res = (((u64)deltapm) *  mult) >> 22;
774 	do_div(res, 1000000);
775 	pr_warning("APIC calibration not consistent "
776 		   "with PM-Timer: %ldms instead of 100ms\n",(long)res);
777 
778 	/* Correct the lapic counter value */
779 	res = (((u64)(*delta)) * pm_100ms);
780 	do_div(res, deltapm);
781 	pr_info("APIC delta adjusted to PM-Timer: "
782 		"%lu (%ld)\n", (unsigned long)res, *delta);
783 	*delta = (long)res;
784 
785 	/* Correct the tsc counter value */
786 	if (boot_cpu_has(X86_FEATURE_TSC)) {
787 		res = (((u64)(*deltatsc)) * pm_100ms);
788 		do_div(res, deltapm);
789 		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
790 					  "PM-Timer: %lu (%ld)\n",
791 					(unsigned long)res, *deltatsc);
792 		*deltatsc = (long)res;
793 	}
794 
795 	return 0;
796 }
797 
798 static int __init calibrate_APIC_clock(void)
799 {
800 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
801 	void (*real_handler)(struct clock_event_device *dev);
802 	unsigned long deltaj;
803 	long delta, deltatsc;
804 	int pm_referenced = 0;
805 
806 	/**
807 	 * check if lapic timer has already been calibrated by platform
808 	 * specific routine, such as tsc calibration code. if so, we just fill
809 	 * in the clockevent structure and return.
810 	 */
811 
812 	if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
813 		return 0;
814 	} else if (lapic_timer_frequency) {
815 		apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
816 				lapic_timer_frequency);
817 		lapic_clockevent.mult = div_sc(lapic_timer_frequency/APIC_DIVISOR,
818 					TICK_NSEC, lapic_clockevent.shift);
819 		lapic_clockevent.max_delta_ns =
820 			clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
821 		lapic_clockevent.max_delta_ticks = 0x7FFFFF;
822 		lapic_clockevent.min_delta_ns =
823 			clockevent_delta2ns(0xF, &lapic_clockevent);
824 		lapic_clockevent.min_delta_ticks = 0xF;
825 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
826 		return 0;
827 	}
828 
829 	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
830 		    "calibrating APIC timer ...\n");
831 
832 	local_irq_disable();
833 
834 	/* Replace the global interrupt handler */
835 	real_handler = global_clock_event->event_handler;
836 	global_clock_event->event_handler = lapic_cal_handler;
837 
838 	/*
839 	 * Setup the APIC counter to maximum. There is no way the lapic
840 	 * can underflow in the 100ms detection time frame
841 	 */
842 	__setup_APIC_LVTT(0xffffffff, 0, 0);
843 
844 	/* Let the interrupts run */
845 	local_irq_enable();
846 
847 	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
848 		cpu_relax();
849 
850 	local_irq_disable();
851 
852 	/* Restore the real event handler */
853 	global_clock_event->event_handler = real_handler;
854 
855 	/* Build delta t1-t2 as apic timer counts down */
856 	delta = lapic_cal_t1 - lapic_cal_t2;
857 	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
858 
859 	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
860 
861 	/* we trust the PM based calibration if possible */
862 	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
863 					&delta, &deltatsc);
864 
865 	/* Calculate the scaled math multiplication factor */
866 	lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
867 				       lapic_clockevent.shift);
868 	lapic_clockevent.max_delta_ns =
869 		clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
870 	lapic_clockevent.max_delta_ticks = 0x7FFFFFFF;
871 	lapic_clockevent.min_delta_ns =
872 		clockevent_delta2ns(0xF, &lapic_clockevent);
873 	lapic_clockevent.min_delta_ticks = 0xF;
874 
875 	lapic_timer_frequency = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
876 
877 	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
878 	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
879 	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
880 		    lapic_timer_frequency);
881 
882 	if (boot_cpu_has(X86_FEATURE_TSC)) {
883 		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
884 			    "%ld.%04ld MHz.\n",
885 			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
886 			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
887 	}
888 
889 	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
890 		    "%u.%04u MHz.\n",
891 		    lapic_timer_frequency / (1000000 / HZ),
892 		    lapic_timer_frequency % (1000000 / HZ));
893 
894 	/*
895 	 * Do a sanity check on the APIC calibration result
896 	 */
897 	if (lapic_timer_frequency < (1000000 / HZ)) {
898 		local_irq_enable();
899 		pr_warning("APIC frequency too slow, disabling apic timer\n");
900 		return -1;
901 	}
902 
903 	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
904 
905 	/*
906 	 * PM timer calibration failed or not turned on
907 	 * so lets try APIC timer based calibration
908 	 */
909 	if (!pm_referenced) {
910 		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
911 
912 		/*
913 		 * Setup the apic timer manually
914 		 */
915 		levt->event_handler = lapic_cal_handler;
916 		lapic_timer_set_periodic(levt);
917 		lapic_cal_loops = -1;
918 
919 		/* Let the interrupts run */
920 		local_irq_enable();
921 
922 		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
923 			cpu_relax();
924 
925 		/* Stop the lapic timer */
926 		local_irq_disable();
927 		lapic_timer_shutdown(levt);
928 
929 		/* Jiffies delta */
930 		deltaj = lapic_cal_j2 - lapic_cal_j1;
931 		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
932 
933 		/* Check, if the jiffies result is consistent */
934 		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
935 			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
936 		else
937 			levt->features |= CLOCK_EVT_FEAT_DUMMY;
938 	}
939 	local_irq_enable();
940 
941 	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
942 		pr_warning("APIC timer disabled due to verification failure\n");
943 			return -1;
944 	}
945 
946 	return 0;
947 }
948 
949 /*
950  * Setup the boot APIC
951  *
952  * Calibrate and verify the result.
953  */
954 void __init setup_boot_APIC_clock(void)
955 {
956 	/*
957 	 * The local apic timer can be disabled via the kernel
958 	 * commandline or from the CPU detection code. Register the lapic
959 	 * timer as a dummy clock event source on SMP systems, so the
960 	 * broadcast mechanism is used. On UP systems simply ignore it.
961 	 */
962 	if (disable_apic_timer) {
963 		pr_info("Disabling APIC timer\n");
964 		/* No broadcast on UP ! */
965 		if (num_possible_cpus() > 1) {
966 			lapic_clockevent.mult = 1;
967 			setup_APIC_timer();
968 		}
969 		return;
970 	}
971 
972 	if (calibrate_APIC_clock()) {
973 		/* No broadcast on UP ! */
974 		if (num_possible_cpus() > 1)
975 			setup_APIC_timer();
976 		return;
977 	}
978 
979 	/*
980 	 * If nmi_watchdog is set to IO_APIC, we need the
981 	 * PIT/HPET going.  Otherwise register lapic as a dummy
982 	 * device.
983 	 */
984 	lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
985 
986 	/* Setup the lapic or request the broadcast */
987 	setup_APIC_timer();
988 	amd_e400_c1e_apic_setup();
989 }
990 
991 void setup_secondary_APIC_clock(void)
992 {
993 	setup_APIC_timer();
994 	amd_e400_c1e_apic_setup();
995 }
996 
997 /*
998  * The guts of the apic timer interrupt
999  */
1000 static void local_apic_timer_interrupt(void)
1001 {
1002 	struct clock_event_device *evt = this_cpu_ptr(&lapic_events);
1003 
1004 	/*
1005 	 * Normally we should not be here till LAPIC has been initialized but
1006 	 * in some cases like kdump, its possible that there is a pending LAPIC
1007 	 * timer interrupt from previous kernel's context and is delivered in
1008 	 * new kernel the moment interrupts are enabled.
1009 	 *
1010 	 * Interrupts are enabled early and LAPIC is setup much later, hence
1011 	 * its possible that when we get here evt->event_handler is NULL.
1012 	 * Check for event_handler being NULL and discard the interrupt as
1013 	 * spurious.
1014 	 */
1015 	if (!evt->event_handler) {
1016 		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n",
1017 			   smp_processor_id());
1018 		/* Switch it off */
1019 		lapic_timer_shutdown(evt);
1020 		return;
1021 	}
1022 
1023 	/*
1024 	 * the NMI deadlock-detector uses this.
1025 	 */
1026 	inc_irq_stat(apic_timer_irqs);
1027 
1028 	evt->event_handler(evt);
1029 }
1030 
1031 /*
1032  * Local APIC timer interrupt. This is the most natural way for doing
1033  * local interrupts, but local timer interrupts can be emulated by
1034  * broadcast interrupts too. [in case the hw doesn't support APIC timers]
1035  *
1036  * [ if a single-CPU system runs an SMP kernel then we call the local
1037  *   interrupt as well. Thus we cannot inline the local irq ... ]
1038  */
1039 __visible void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
1040 {
1041 	struct pt_regs *old_regs = set_irq_regs(regs);
1042 
1043 	/*
1044 	 * NOTE! We'd better ACK the irq immediately,
1045 	 * because timer handling can be slow.
1046 	 *
1047 	 * update_process_times() expects us to have done irq_enter().
1048 	 * Besides, if we don't timer interrupts ignore the global
1049 	 * interrupt lock, which is the WrongThing (tm) to do.
1050 	 */
1051 	entering_ack_irq();
1052 	trace_local_timer_entry(LOCAL_TIMER_VECTOR);
1053 	local_apic_timer_interrupt();
1054 	trace_local_timer_exit(LOCAL_TIMER_VECTOR);
1055 	exiting_irq();
1056 
1057 	set_irq_regs(old_regs);
1058 }
1059 
1060 int setup_profiling_timer(unsigned int multiplier)
1061 {
1062 	return -EINVAL;
1063 }
1064 
1065 /*
1066  * Local APIC start and shutdown
1067  */
1068 
1069 /**
1070  * clear_local_APIC - shutdown the local APIC
1071  *
1072  * This is called, when a CPU is disabled and before rebooting, so the state of
1073  * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
1074  * leftovers during boot.
1075  */
1076 void clear_local_APIC(void)
1077 {
1078 	int maxlvt;
1079 	u32 v;
1080 
1081 	/* APIC hasn't been mapped yet */
1082 	if (!x2apic_mode && !apic_phys)
1083 		return;
1084 
1085 	maxlvt = lapic_get_maxlvt();
1086 	/*
1087 	 * Masking an LVT entry can trigger a local APIC error
1088 	 * if the vector is zero. Mask LVTERR first to prevent this.
1089 	 */
1090 	if (maxlvt >= 3) {
1091 		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
1092 		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
1093 	}
1094 	/*
1095 	 * Careful: we have to set masks only first to deassert
1096 	 * any level-triggered sources.
1097 	 */
1098 	v = apic_read(APIC_LVTT);
1099 	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
1100 	v = apic_read(APIC_LVT0);
1101 	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
1102 	v = apic_read(APIC_LVT1);
1103 	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
1104 	if (maxlvt >= 4) {
1105 		v = apic_read(APIC_LVTPC);
1106 		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
1107 	}
1108 
1109 	/* lets not touch this if we didn't frob it */
1110 #ifdef CONFIG_X86_THERMAL_VECTOR
1111 	if (maxlvt >= 5) {
1112 		v = apic_read(APIC_LVTTHMR);
1113 		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
1114 	}
1115 #endif
1116 #ifdef CONFIG_X86_MCE_INTEL
1117 	if (maxlvt >= 6) {
1118 		v = apic_read(APIC_LVTCMCI);
1119 		if (!(v & APIC_LVT_MASKED))
1120 			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
1121 	}
1122 #endif
1123 
1124 	/*
1125 	 * Clean APIC state for other OSs:
1126 	 */
1127 	apic_write(APIC_LVTT, APIC_LVT_MASKED);
1128 	apic_write(APIC_LVT0, APIC_LVT_MASKED);
1129 	apic_write(APIC_LVT1, APIC_LVT_MASKED);
1130 	if (maxlvt >= 3)
1131 		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
1132 	if (maxlvt >= 4)
1133 		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
1134 
1135 	/* Integrated APIC (!82489DX) ? */
1136 	if (lapic_is_integrated()) {
1137 		if (maxlvt > 3)
1138 			/* Clear ESR due to Pentium errata 3AP and 11AP */
1139 			apic_write(APIC_ESR, 0);
1140 		apic_read(APIC_ESR);
1141 	}
1142 }
1143 
1144 /**
1145  * disable_local_APIC - clear and disable the local APIC
1146  */
1147 void disable_local_APIC(void)
1148 {
1149 	unsigned int value;
1150 
1151 	/* APIC hasn't been mapped yet */
1152 	if (!x2apic_mode && !apic_phys)
1153 		return;
1154 
1155 	clear_local_APIC();
1156 
1157 	/*
1158 	 * Disable APIC (implies clearing of registers
1159 	 * for 82489DX!).
1160 	 */
1161 	value = apic_read(APIC_SPIV);
1162 	value &= ~APIC_SPIV_APIC_ENABLED;
1163 	apic_write(APIC_SPIV, value);
1164 
1165 #ifdef CONFIG_X86_32
1166 	/*
1167 	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
1168 	 * restore the disabled state.
1169 	 */
1170 	if (enabled_via_apicbase) {
1171 		unsigned int l, h;
1172 
1173 		rdmsr(MSR_IA32_APICBASE, l, h);
1174 		l &= ~MSR_IA32_APICBASE_ENABLE;
1175 		wrmsr(MSR_IA32_APICBASE, l, h);
1176 	}
1177 #endif
1178 }
1179 
1180 /*
1181  * If Linux enabled the LAPIC against the BIOS default disable it down before
1182  * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
1183  * not power-off.  Additionally clear all LVT entries before disable_local_APIC
1184  * for the case where Linux didn't enable the LAPIC.
1185  */
1186 void lapic_shutdown(void)
1187 {
1188 	unsigned long flags;
1189 
1190 	if (!boot_cpu_has(X86_FEATURE_APIC) && !apic_from_smp_config())
1191 		return;
1192 
1193 	local_irq_save(flags);
1194 
1195 #ifdef CONFIG_X86_32
1196 	if (!enabled_via_apicbase)
1197 		clear_local_APIC();
1198 	else
1199 #endif
1200 		disable_local_APIC();
1201 
1202 
1203 	local_irq_restore(flags);
1204 }
1205 
1206 /**
1207  * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1208  */
1209 void __init sync_Arb_IDs(void)
1210 {
1211 	/*
1212 	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1213 	 * needed on AMD.
1214 	 */
1215 	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1216 		return;
1217 
1218 	/*
1219 	 * Wait for idle.
1220 	 */
1221 	apic_wait_icr_idle();
1222 
1223 	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1224 	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1225 			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1226 }
1227 
1228 enum apic_intr_mode_id apic_intr_mode;
1229 
1230 static int __init apic_intr_mode_select(void)
1231 {
1232 	/* Check kernel option */
1233 	if (disable_apic) {
1234 		pr_info("APIC disabled via kernel command line\n");
1235 		return APIC_PIC;
1236 	}
1237 
1238 	/* Check BIOS */
1239 #ifdef CONFIG_X86_64
1240 	/* On 64-bit, the APIC must be integrated, Check local APIC only */
1241 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1242 		disable_apic = 1;
1243 		pr_info("APIC disabled by BIOS\n");
1244 		return APIC_PIC;
1245 	}
1246 #else
1247 	/* On 32-bit, the APIC may be integrated APIC or 82489DX */
1248 
1249 	/* Neither 82489DX nor integrated APIC ? */
1250 	if (!boot_cpu_has(X86_FEATURE_APIC) && !smp_found_config) {
1251 		disable_apic = 1;
1252 		return APIC_PIC;
1253 	}
1254 
1255 	/* If the BIOS pretends there is an integrated APIC ? */
1256 	if (!boot_cpu_has(X86_FEATURE_APIC) &&
1257 		APIC_INTEGRATED(boot_cpu_apic_version)) {
1258 		disable_apic = 1;
1259 		pr_err(FW_BUG "Local APIC %d not detected, force emulation\n",
1260 				       boot_cpu_physical_apicid);
1261 		return APIC_PIC;
1262 	}
1263 #endif
1264 
1265 	/* Check MP table or ACPI MADT configuration */
1266 	if (!smp_found_config) {
1267 		disable_ioapic_support();
1268 		if (!acpi_lapic) {
1269 			pr_info("APIC: ACPI MADT or MP tables are not detected\n");
1270 			return APIC_VIRTUAL_WIRE_NO_CONFIG;
1271 		}
1272 		return APIC_VIRTUAL_WIRE;
1273 	}
1274 
1275 #ifdef CONFIG_SMP
1276 	/* If SMP should be disabled, then really disable it! */
1277 	if (!setup_max_cpus) {
1278 		pr_info("APIC: SMP mode deactivated\n");
1279 		return APIC_SYMMETRIC_IO_NO_ROUTING;
1280 	}
1281 
1282 	if (read_apic_id() != boot_cpu_physical_apicid) {
1283 		panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
1284 		     read_apic_id(), boot_cpu_physical_apicid);
1285 		/* Or can we switch back to PIC here? */
1286 	}
1287 #endif
1288 
1289 	return APIC_SYMMETRIC_IO;
1290 }
1291 
1292 /*
1293  * An initial setup of the virtual wire mode.
1294  */
1295 void __init init_bsp_APIC(void)
1296 {
1297 	unsigned int value;
1298 
1299 	/*
1300 	 * Don't do the setup now if we have a SMP BIOS as the
1301 	 * through-I/O-APIC virtual wire mode might be active.
1302 	 */
1303 	if (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC))
1304 		return;
1305 
1306 	/*
1307 	 * Do not trust the local APIC being empty at bootup.
1308 	 */
1309 	clear_local_APIC();
1310 
1311 	/*
1312 	 * Enable APIC.
1313 	 */
1314 	value = apic_read(APIC_SPIV);
1315 	value &= ~APIC_VECTOR_MASK;
1316 	value |= APIC_SPIV_APIC_ENABLED;
1317 
1318 #ifdef CONFIG_X86_32
1319 	/* This bit is reserved on P4/Xeon and should be cleared */
1320 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1321 	    (boot_cpu_data.x86 == 15))
1322 		value &= ~APIC_SPIV_FOCUS_DISABLED;
1323 	else
1324 #endif
1325 		value |= APIC_SPIV_FOCUS_DISABLED;
1326 	value |= SPURIOUS_APIC_VECTOR;
1327 	apic_write(APIC_SPIV, value);
1328 
1329 	/*
1330 	 * Set up the virtual wire mode.
1331 	 */
1332 	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1333 	value = APIC_DM_NMI;
1334 	if (!lapic_is_integrated())		/* 82489DX */
1335 		value |= APIC_LVT_LEVEL_TRIGGER;
1336 	if (apic_extnmi == APIC_EXTNMI_NONE)
1337 		value |= APIC_LVT_MASKED;
1338 	apic_write(APIC_LVT1, value);
1339 }
1340 
1341 /* Init the interrupt delivery mode for the BSP */
1342 void __init apic_intr_mode_init(void)
1343 {
1344 	bool upmode = IS_ENABLED(CONFIG_UP_LATE_INIT);
1345 
1346 	apic_intr_mode = apic_intr_mode_select();
1347 
1348 	switch (apic_intr_mode) {
1349 	case APIC_PIC:
1350 		pr_info("APIC: Keep in PIC mode(8259)\n");
1351 		return;
1352 	case APIC_VIRTUAL_WIRE:
1353 		pr_info("APIC: Switch to virtual wire mode setup\n");
1354 		default_setup_apic_routing();
1355 		break;
1356 	case APIC_VIRTUAL_WIRE_NO_CONFIG:
1357 		pr_info("APIC: Switch to virtual wire mode setup with no configuration\n");
1358 		upmode = true;
1359 		default_setup_apic_routing();
1360 		break;
1361 	case APIC_SYMMETRIC_IO:
1362 		pr_info("APIC: Switch to symmetric I/O mode setup\n");
1363 		default_setup_apic_routing();
1364 		break;
1365 	case APIC_SYMMETRIC_IO_NO_ROUTING:
1366 		pr_info("APIC: Switch to symmetric I/O mode setup in no SMP routine\n");
1367 		break;
1368 	}
1369 
1370 	apic_bsp_setup(upmode);
1371 }
1372 
1373 static void lapic_setup_esr(void)
1374 {
1375 	unsigned int oldvalue, value, maxlvt;
1376 
1377 	if (!lapic_is_integrated()) {
1378 		pr_info("No ESR for 82489DX.\n");
1379 		return;
1380 	}
1381 
1382 	if (apic->disable_esr) {
1383 		/*
1384 		 * Something untraceable is creating bad interrupts on
1385 		 * secondary quads ... for the moment, just leave the
1386 		 * ESR disabled - we can't do anything useful with the
1387 		 * errors anyway - mbligh
1388 		 */
1389 		pr_info("Leaving ESR disabled.\n");
1390 		return;
1391 	}
1392 
1393 	maxlvt = lapic_get_maxlvt();
1394 	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1395 		apic_write(APIC_ESR, 0);
1396 	oldvalue = apic_read(APIC_ESR);
1397 
1398 	/* enables sending errors */
1399 	value = ERROR_APIC_VECTOR;
1400 	apic_write(APIC_LVTERR, value);
1401 
1402 	/*
1403 	 * spec says clear errors after enabling vector.
1404 	 */
1405 	if (maxlvt > 3)
1406 		apic_write(APIC_ESR, 0);
1407 	value = apic_read(APIC_ESR);
1408 	if (value != oldvalue)
1409 		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1410 			"vector: 0x%08x  after: 0x%08x\n",
1411 			oldvalue, value);
1412 }
1413 
1414 static void apic_pending_intr_clear(void)
1415 {
1416 	long long max_loops = cpu_khz ? cpu_khz : 1000000;
1417 	unsigned long long tsc = 0, ntsc;
1418 	unsigned int queued;
1419 	unsigned long value;
1420 	int i, j, acked = 0;
1421 
1422 	if (boot_cpu_has(X86_FEATURE_TSC))
1423 		tsc = rdtsc();
1424 	/*
1425 	 * After a crash, we no longer service the interrupts and a pending
1426 	 * interrupt from previous kernel might still have ISR bit set.
1427 	 *
1428 	 * Most probably by now CPU has serviced that pending interrupt and
1429 	 * it might not have done the ack_APIC_irq() because it thought,
1430 	 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1431 	 * does not clear the ISR bit and cpu thinks it has already serivced
1432 	 * the interrupt. Hence a vector might get locked. It was noticed
1433 	 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1434 	 */
1435 	do {
1436 		queued = 0;
1437 		for (i = APIC_ISR_NR - 1; i >= 0; i--)
1438 			queued |= apic_read(APIC_IRR + i*0x10);
1439 
1440 		for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1441 			value = apic_read(APIC_ISR + i*0x10);
1442 			for_each_set_bit(j, &value, 32) {
1443 				ack_APIC_irq();
1444 				acked++;
1445 			}
1446 		}
1447 		if (acked > 256) {
1448 			pr_err("LAPIC pending interrupts after %d EOI\n", acked);
1449 			break;
1450 		}
1451 		if (queued) {
1452 			if (boot_cpu_has(X86_FEATURE_TSC) && cpu_khz) {
1453 				ntsc = rdtsc();
1454 				max_loops = (cpu_khz << 10) - (ntsc - tsc);
1455 			} else {
1456 				max_loops--;
1457 			}
1458 		}
1459 	} while (queued && max_loops > 0);
1460 	WARN_ON(max_loops <= 0);
1461 }
1462 
1463 /**
1464  * setup_local_APIC - setup the local APIC
1465  *
1466  * Used to setup local APIC while initializing BSP or bringing up APs.
1467  * Always called with preemption disabled.
1468  */
1469 static void setup_local_APIC(void)
1470 {
1471 	int cpu = smp_processor_id();
1472 	unsigned int value;
1473 #ifdef CONFIG_X86_32
1474 	int logical_apicid, ldr_apicid;
1475 #endif
1476 
1477 
1478 	if (disable_apic) {
1479 		disable_ioapic_support();
1480 		return;
1481 	}
1482 
1483 #ifdef CONFIG_X86_32
1484 	/* Pound the ESR really hard over the head with a big hammer - mbligh */
1485 	if (lapic_is_integrated() && apic->disable_esr) {
1486 		apic_write(APIC_ESR, 0);
1487 		apic_write(APIC_ESR, 0);
1488 		apic_write(APIC_ESR, 0);
1489 		apic_write(APIC_ESR, 0);
1490 	}
1491 #endif
1492 	perf_events_lapic_init();
1493 
1494 	/*
1495 	 * Double-check whether this APIC is really registered.
1496 	 * This is meaningless in clustered apic mode, so we skip it.
1497 	 */
1498 	BUG_ON(!apic->apic_id_registered());
1499 
1500 	/*
1501 	 * Intel recommends to set DFR, LDR and TPR before enabling
1502 	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
1503 	 * document number 292116).  So here it goes...
1504 	 */
1505 	apic->init_apic_ldr();
1506 
1507 #ifdef CONFIG_X86_32
1508 	/*
1509 	 * APIC LDR is initialized.  If logical_apicid mapping was
1510 	 * initialized during get_smp_config(), make sure it matches the
1511 	 * actual value.
1512 	 */
1513 	logical_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
1514 	ldr_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
1515 	WARN_ON(logical_apicid != BAD_APICID && logical_apicid != ldr_apicid);
1516 	/* always use the value from LDR */
1517 	early_per_cpu(x86_cpu_to_logical_apicid, cpu) = ldr_apicid;
1518 #endif
1519 
1520 	/*
1521 	 * Set Task Priority to 'accept all'. We never change this
1522 	 * later on.
1523 	 */
1524 	value = apic_read(APIC_TASKPRI);
1525 	value &= ~APIC_TPRI_MASK;
1526 	apic_write(APIC_TASKPRI, value);
1527 
1528 	apic_pending_intr_clear();
1529 
1530 	/*
1531 	 * Now that we are all set up, enable the APIC
1532 	 */
1533 	value = apic_read(APIC_SPIV);
1534 	value &= ~APIC_VECTOR_MASK;
1535 	/*
1536 	 * Enable APIC
1537 	 */
1538 	value |= APIC_SPIV_APIC_ENABLED;
1539 
1540 #ifdef CONFIG_X86_32
1541 	/*
1542 	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1543 	 * certain networking cards. If high frequency interrupts are
1544 	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1545 	 * entry is masked/unmasked at a high rate as well then sooner or
1546 	 * later IOAPIC line gets 'stuck', no more interrupts are received
1547 	 * from the device. If focus CPU is disabled then the hang goes
1548 	 * away, oh well :-(
1549 	 *
1550 	 * [ This bug can be reproduced easily with a level-triggered
1551 	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1552 	 *   BX chipset. ]
1553 	 */
1554 	/*
1555 	 * Actually disabling the focus CPU check just makes the hang less
1556 	 * frequent as it makes the interrupt distributon model be more
1557 	 * like LRU than MRU (the short-term load is more even across CPUs).
1558 	 */
1559 
1560 	/*
1561 	 * - enable focus processor (bit==0)
1562 	 * - 64bit mode always use processor focus
1563 	 *   so no need to set it
1564 	 */
1565 	value &= ~APIC_SPIV_FOCUS_DISABLED;
1566 #endif
1567 
1568 	/*
1569 	 * Set spurious IRQ vector
1570 	 */
1571 	value |= SPURIOUS_APIC_VECTOR;
1572 	apic_write(APIC_SPIV, value);
1573 
1574 	/*
1575 	 * Set up LVT0, LVT1:
1576 	 *
1577 	 * set up through-local-APIC on the boot CPU's LINT0. This is not
1578 	 * strictly necessary in pure symmetric-IO mode, but sometimes
1579 	 * we delegate interrupts to the 8259A.
1580 	 */
1581 	/*
1582 	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1583 	 */
1584 	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1585 	if (!cpu && (pic_mode || !value || skip_ioapic_setup)) {
1586 		value = APIC_DM_EXTINT;
1587 		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
1588 	} else {
1589 		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1590 		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
1591 	}
1592 	apic_write(APIC_LVT0, value);
1593 
1594 	/*
1595 	 * Only the BSP sees the LINT1 NMI signal by default. This can be
1596 	 * modified by apic_extnmi= boot option.
1597 	 */
1598 	if ((!cpu && apic_extnmi != APIC_EXTNMI_NONE) ||
1599 	    apic_extnmi == APIC_EXTNMI_ALL)
1600 		value = APIC_DM_NMI;
1601 	else
1602 		value = APIC_DM_NMI | APIC_LVT_MASKED;
1603 
1604 	/* Is 82489DX ? */
1605 	if (!lapic_is_integrated())
1606 		value |= APIC_LVT_LEVEL_TRIGGER;
1607 	apic_write(APIC_LVT1, value);
1608 
1609 #ifdef CONFIG_X86_MCE_INTEL
1610 	/* Recheck CMCI information after local APIC is up on CPU #0 */
1611 	if (!cpu)
1612 		cmci_recheck();
1613 #endif
1614 }
1615 
1616 static void end_local_APIC_setup(void)
1617 {
1618 	lapic_setup_esr();
1619 
1620 #ifdef CONFIG_X86_32
1621 	{
1622 		unsigned int value;
1623 		/* Disable the local apic timer */
1624 		value = apic_read(APIC_LVTT);
1625 		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1626 		apic_write(APIC_LVTT, value);
1627 	}
1628 #endif
1629 
1630 	apic_pm_activate();
1631 }
1632 
1633 /*
1634  * APIC setup function for application processors. Called from smpboot.c
1635  */
1636 void apic_ap_setup(void)
1637 {
1638 	setup_local_APIC();
1639 	end_local_APIC_setup();
1640 }
1641 
1642 #ifdef CONFIG_X86_X2APIC
1643 int x2apic_mode;
1644 
1645 enum {
1646 	X2APIC_OFF,
1647 	X2APIC_ON,
1648 	X2APIC_DISABLED,
1649 };
1650 static int x2apic_state;
1651 
1652 static void __x2apic_disable(void)
1653 {
1654 	u64 msr;
1655 
1656 	if (!boot_cpu_has(X86_FEATURE_APIC))
1657 		return;
1658 
1659 	rdmsrl(MSR_IA32_APICBASE, msr);
1660 	if (!(msr & X2APIC_ENABLE))
1661 		return;
1662 	/* Disable xapic and x2apic first and then reenable xapic mode */
1663 	wrmsrl(MSR_IA32_APICBASE, msr & ~(X2APIC_ENABLE | XAPIC_ENABLE));
1664 	wrmsrl(MSR_IA32_APICBASE, msr & ~X2APIC_ENABLE);
1665 	printk_once(KERN_INFO "x2apic disabled\n");
1666 }
1667 
1668 static void __x2apic_enable(void)
1669 {
1670 	u64 msr;
1671 
1672 	rdmsrl(MSR_IA32_APICBASE, msr);
1673 	if (msr & X2APIC_ENABLE)
1674 		return;
1675 	wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE);
1676 	printk_once(KERN_INFO "x2apic enabled\n");
1677 }
1678 
1679 static int __init setup_nox2apic(char *str)
1680 {
1681 	if (x2apic_enabled()) {
1682 		int apicid = native_apic_msr_read(APIC_ID);
1683 
1684 		if (apicid >= 255) {
1685 			pr_warning("Apicid: %08x, cannot enforce nox2apic\n",
1686 				   apicid);
1687 			return 0;
1688 		}
1689 		pr_warning("x2apic already enabled.\n");
1690 		__x2apic_disable();
1691 	}
1692 	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
1693 	x2apic_state = X2APIC_DISABLED;
1694 	x2apic_mode = 0;
1695 	return 0;
1696 }
1697 early_param("nox2apic", setup_nox2apic);
1698 
1699 /* Called from cpu_init() to enable x2apic on (secondary) cpus */
1700 void x2apic_setup(void)
1701 {
1702 	/*
1703 	 * If x2apic is not in ON state, disable it if already enabled
1704 	 * from BIOS.
1705 	 */
1706 	if (x2apic_state != X2APIC_ON) {
1707 		__x2apic_disable();
1708 		return;
1709 	}
1710 	__x2apic_enable();
1711 }
1712 
1713 static __init void x2apic_disable(void)
1714 {
1715 	u32 x2apic_id, state = x2apic_state;
1716 
1717 	x2apic_mode = 0;
1718 	x2apic_state = X2APIC_DISABLED;
1719 
1720 	if (state != X2APIC_ON)
1721 		return;
1722 
1723 	x2apic_id = read_apic_id();
1724 	if (x2apic_id >= 255)
1725 		panic("Cannot disable x2apic, id: %08x\n", x2apic_id);
1726 
1727 	__x2apic_disable();
1728 	register_lapic_address(mp_lapic_addr);
1729 }
1730 
1731 static __init void x2apic_enable(void)
1732 {
1733 	if (x2apic_state != X2APIC_OFF)
1734 		return;
1735 
1736 	x2apic_mode = 1;
1737 	x2apic_state = X2APIC_ON;
1738 	__x2apic_enable();
1739 }
1740 
1741 static __init void try_to_enable_x2apic(int remap_mode)
1742 {
1743 	if (x2apic_state == X2APIC_DISABLED)
1744 		return;
1745 
1746 	if (remap_mode != IRQ_REMAP_X2APIC_MODE) {
1747 		/* IR is required if there is APIC ID > 255 even when running
1748 		 * under KVM
1749 		 */
1750 		if (max_physical_apicid > 255 ||
1751 		    !x86_init.hyper.x2apic_available()) {
1752 			pr_info("x2apic: IRQ remapping doesn't support X2APIC mode\n");
1753 			x2apic_disable();
1754 			return;
1755 		}
1756 
1757 		/*
1758 		 * without IR all CPUs can be addressed by IOAPIC/MSI
1759 		 * only in physical mode
1760 		 */
1761 		x2apic_phys = 1;
1762 	}
1763 	x2apic_enable();
1764 }
1765 
1766 void __init check_x2apic(void)
1767 {
1768 	if (x2apic_enabled()) {
1769 		pr_info("x2apic: enabled by BIOS, switching to x2apic ops\n");
1770 		x2apic_mode = 1;
1771 		x2apic_state = X2APIC_ON;
1772 	} else if (!boot_cpu_has(X86_FEATURE_X2APIC)) {
1773 		x2apic_state = X2APIC_DISABLED;
1774 	}
1775 }
1776 #else /* CONFIG_X86_X2APIC */
1777 static int __init validate_x2apic(void)
1778 {
1779 	if (!apic_is_x2apic_enabled())
1780 		return 0;
1781 	/*
1782 	 * Checkme: Can we simply turn off x2apic here instead of panic?
1783 	 */
1784 	panic("BIOS has enabled x2apic but kernel doesn't support x2apic, please disable x2apic in BIOS.\n");
1785 }
1786 early_initcall(validate_x2apic);
1787 
1788 static inline void try_to_enable_x2apic(int remap_mode) { }
1789 static inline void __x2apic_enable(void) { }
1790 #endif /* !CONFIG_X86_X2APIC */
1791 
1792 void __init enable_IR_x2apic(void)
1793 {
1794 	unsigned long flags;
1795 	int ret, ir_stat;
1796 
1797 	if (skip_ioapic_setup) {
1798 		pr_info("Not enabling interrupt remapping due to skipped IO-APIC setup\n");
1799 		return;
1800 	}
1801 
1802 	ir_stat = irq_remapping_prepare();
1803 	if (ir_stat < 0 && !x2apic_supported())
1804 		return;
1805 
1806 	ret = save_ioapic_entries();
1807 	if (ret) {
1808 		pr_info("Saving IO-APIC state failed: %d\n", ret);
1809 		return;
1810 	}
1811 
1812 	local_irq_save(flags);
1813 	legacy_pic->mask_all();
1814 	mask_ioapic_entries();
1815 
1816 	/* If irq_remapping_prepare() succeeded, try to enable it */
1817 	if (ir_stat >= 0)
1818 		ir_stat = irq_remapping_enable();
1819 	/* ir_stat contains the remap mode or an error code */
1820 	try_to_enable_x2apic(ir_stat);
1821 
1822 	if (ir_stat < 0)
1823 		restore_ioapic_entries();
1824 	legacy_pic->restore_mask();
1825 	local_irq_restore(flags);
1826 }
1827 
1828 #ifdef CONFIG_X86_64
1829 /*
1830  * Detect and enable local APICs on non-SMP boards.
1831  * Original code written by Keir Fraser.
1832  * On AMD64 we trust the BIOS - if it says no APIC it is likely
1833  * not correctly set up (usually the APIC timer won't work etc.)
1834  */
1835 static int __init detect_init_APIC(void)
1836 {
1837 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1838 		pr_info("No local APIC present\n");
1839 		return -1;
1840 	}
1841 
1842 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1843 	return 0;
1844 }
1845 #else
1846 
1847 static int __init apic_verify(void)
1848 {
1849 	u32 features, h, l;
1850 
1851 	/*
1852 	 * The APIC feature bit should now be enabled
1853 	 * in `cpuid'
1854 	 */
1855 	features = cpuid_edx(1);
1856 	if (!(features & (1 << X86_FEATURE_APIC))) {
1857 		pr_warning("Could not enable APIC!\n");
1858 		return -1;
1859 	}
1860 	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1861 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1862 
1863 	/* The BIOS may have set up the APIC at some other address */
1864 	if (boot_cpu_data.x86 >= 6) {
1865 		rdmsr(MSR_IA32_APICBASE, l, h);
1866 		if (l & MSR_IA32_APICBASE_ENABLE)
1867 			mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1868 	}
1869 
1870 	pr_info("Found and enabled local APIC!\n");
1871 	return 0;
1872 }
1873 
1874 int __init apic_force_enable(unsigned long addr)
1875 {
1876 	u32 h, l;
1877 
1878 	if (disable_apic)
1879 		return -1;
1880 
1881 	/*
1882 	 * Some BIOSes disable the local APIC in the APIC_BASE
1883 	 * MSR. This can only be done in software for Intel P6 or later
1884 	 * and AMD K7 (Model > 1) or later.
1885 	 */
1886 	if (boot_cpu_data.x86 >= 6) {
1887 		rdmsr(MSR_IA32_APICBASE, l, h);
1888 		if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1889 			pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1890 			l &= ~MSR_IA32_APICBASE_BASE;
1891 			l |= MSR_IA32_APICBASE_ENABLE | addr;
1892 			wrmsr(MSR_IA32_APICBASE, l, h);
1893 			enabled_via_apicbase = 1;
1894 		}
1895 	}
1896 	return apic_verify();
1897 }
1898 
1899 /*
1900  * Detect and initialize APIC
1901  */
1902 static int __init detect_init_APIC(void)
1903 {
1904 	/* Disabled by kernel option? */
1905 	if (disable_apic)
1906 		return -1;
1907 
1908 	switch (boot_cpu_data.x86_vendor) {
1909 	case X86_VENDOR_AMD:
1910 		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1911 		    (boot_cpu_data.x86 >= 15))
1912 			break;
1913 		goto no_apic;
1914 	case X86_VENDOR_INTEL:
1915 		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1916 		    (boot_cpu_data.x86 == 5 && boot_cpu_has(X86_FEATURE_APIC)))
1917 			break;
1918 		goto no_apic;
1919 	default:
1920 		goto no_apic;
1921 	}
1922 
1923 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1924 		/*
1925 		 * Over-ride BIOS and try to enable the local APIC only if
1926 		 * "lapic" specified.
1927 		 */
1928 		if (!force_enable_local_apic) {
1929 			pr_info("Local APIC disabled by BIOS -- "
1930 				"you can enable it with \"lapic\"\n");
1931 			return -1;
1932 		}
1933 		if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
1934 			return -1;
1935 	} else {
1936 		if (apic_verify())
1937 			return -1;
1938 	}
1939 
1940 	apic_pm_activate();
1941 
1942 	return 0;
1943 
1944 no_apic:
1945 	pr_info("No local APIC present or hardware disabled\n");
1946 	return -1;
1947 }
1948 #endif
1949 
1950 /**
1951  * init_apic_mappings - initialize APIC mappings
1952  */
1953 void __init init_apic_mappings(void)
1954 {
1955 	unsigned int new_apicid;
1956 
1957 	apic_check_deadline_errata();
1958 
1959 	if (x2apic_mode) {
1960 		boot_cpu_physical_apicid = read_apic_id();
1961 		return;
1962 	}
1963 
1964 	/* If no local APIC can be found return early */
1965 	if (!smp_found_config && detect_init_APIC()) {
1966 		/* lets NOP'ify apic operations */
1967 		pr_info("APIC: disable apic facility\n");
1968 		apic_disable();
1969 	} else {
1970 		apic_phys = mp_lapic_addr;
1971 
1972 		/*
1973 		 * If the system has ACPI MADT tables or MP info, the LAPIC
1974 		 * address is already registered.
1975 		 */
1976 		if (!acpi_lapic && !smp_found_config)
1977 			register_lapic_address(apic_phys);
1978 	}
1979 
1980 	/*
1981 	 * Fetch the APIC ID of the BSP in case we have a
1982 	 * default configuration (or the MP table is broken).
1983 	 */
1984 	new_apicid = read_apic_id();
1985 	if (boot_cpu_physical_apicid != new_apicid) {
1986 		boot_cpu_physical_apicid = new_apicid;
1987 		/*
1988 		 * yeah -- we lie about apic_version
1989 		 * in case if apic was disabled via boot option
1990 		 * but it's not a problem for SMP compiled kernel
1991 		 * since apic_intr_mode_select is prepared for such
1992 		 * a case and disable smp mode
1993 		 */
1994 		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
1995 	}
1996 }
1997 
1998 void __init register_lapic_address(unsigned long address)
1999 {
2000 	mp_lapic_addr = address;
2001 
2002 	if (!x2apic_mode) {
2003 		set_fixmap_nocache(FIX_APIC_BASE, address);
2004 		apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
2005 			    APIC_BASE, address);
2006 	}
2007 	if (boot_cpu_physical_apicid == -1U) {
2008 		boot_cpu_physical_apicid  = read_apic_id();
2009 		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
2010 	}
2011 }
2012 
2013 /*
2014  * Local APIC interrupts
2015  */
2016 
2017 /*
2018  * This interrupt should _never_ happen with our APIC/SMP architecture
2019  */
2020 __visible void __irq_entry smp_spurious_interrupt(struct pt_regs *regs)
2021 {
2022 	u8 vector = ~regs->orig_ax;
2023 	u32 v;
2024 
2025 	entering_irq();
2026 	trace_spurious_apic_entry(vector);
2027 
2028 	/*
2029 	 * Check if this really is a spurious interrupt and ACK it
2030 	 * if it is a vectored one.  Just in case...
2031 	 * Spurious interrupts should not be ACKed.
2032 	 */
2033 	v = apic_read(APIC_ISR + ((vector & ~0x1f) >> 1));
2034 	if (v & (1 << (vector & 0x1f)))
2035 		ack_APIC_irq();
2036 
2037 	inc_irq_stat(irq_spurious_count);
2038 
2039 	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
2040 	pr_info("spurious APIC interrupt through vector %02x on CPU#%d, "
2041 		"should never happen.\n", vector, smp_processor_id());
2042 
2043 	trace_spurious_apic_exit(vector);
2044 	exiting_irq();
2045 }
2046 
2047 /*
2048  * This interrupt should never happen with our APIC/SMP architecture
2049  */
2050 __visible void __irq_entry smp_error_interrupt(struct pt_regs *regs)
2051 {
2052 	static const char * const error_interrupt_reason[] = {
2053 		"Send CS error",		/* APIC Error Bit 0 */
2054 		"Receive CS error",		/* APIC Error Bit 1 */
2055 		"Send accept error",		/* APIC Error Bit 2 */
2056 		"Receive accept error",		/* APIC Error Bit 3 */
2057 		"Redirectable IPI",		/* APIC Error Bit 4 */
2058 		"Send illegal vector",		/* APIC Error Bit 5 */
2059 		"Received illegal vector",	/* APIC Error Bit 6 */
2060 		"Illegal register address",	/* APIC Error Bit 7 */
2061 	};
2062 	u32 v, i = 0;
2063 
2064 	entering_irq();
2065 	trace_error_apic_entry(ERROR_APIC_VECTOR);
2066 
2067 	/* First tickle the hardware, only then report what went on. -- REW */
2068 	if (lapic_get_maxlvt() > 3)	/* Due to the Pentium erratum 3AP. */
2069 		apic_write(APIC_ESR, 0);
2070 	v = apic_read(APIC_ESR);
2071 	ack_APIC_irq();
2072 	atomic_inc(&irq_err_count);
2073 
2074 	apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x",
2075 		    smp_processor_id(), v);
2076 
2077 	v &= 0xff;
2078 	while (v) {
2079 		if (v & 0x1)
2080 			apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
2081 		i++;
2082 		v >>= 1;
2083 	}
2084 
2085 	apic_printk(APIC_DEBUG, KERN_CONT "\n");
2086 
2087 	trace_error_apic_exit(ERROR_APIC_VECTOR);
2088 	exiting_irq();
2089 }
2090 
2091 /**
2092  * connect_bsp_APIC - attach the APIC to the interrupt system
2093  */
2094 static void __init connect_bsp_APIC(void)
2095 {
2096 #ifdef CONFIG_X86_32
2097 	if (pic_mode) {
2098 		/*
2099 		 * Do not trust the local APIC being empty at bootup.
2100 		 */
2101 		clear_local_APIC();
2102 		/*
2103 		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
2104 		 * local APIC to INT and NMI lines.
2105 		 */
2106 		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
2107 				"enabling APIC mode.\n");
2108 		imcr_pic_to_apic();
2109 	}
2110 #endif
2111 }
2112 
2113 /**
2114  * disconnect_bsp_APIC - detach the APIC from the interrupt system
2115  * @virt_wire_setup:	indicates, whether virtual wire mode is selected
2116  *
2117  * Virtual wire mode is necessary to deliver legacy interrupts even when the
2118  * APIC is disabled.
2119  */
2120 void disconnect_bsp_APIC(int virt_wire_setup)
2121 {
2122 	unsigned int value;
2123 
2124 #ifdef CONFIG_X86_32
2125 	if (pic_mode) {
2126 		/*
2127 		 * Put the board back into PIC mode (has an effect only on
2128 		 * certain older boards).  Note that APIC interrupts, including
2129 		 * IPIs, won't work beyond this point!  The only exception are
2130 		 * INIT IPIs.
2131 		 */
2132 		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
2133 				"entering PIC mode.\n");
2134 		imcr_apic_to_pic();
2135 		return;
2136 	}
2137 #endif
2138 
2139 	/* Go back to Virtual Wire compatibility mode */
2140 
2141 	/* For the spurious interrupt use vector F, and enable it */
2142 	value = apic_read(APIC_SPIV);
2143 	value &= ~APIC_VECTOR_MASK;
2144 	value |= APIC_SPIV_APIC_ENABLED;
2145 	value |= 0xf;
2146 	apic_write(APIC_SPIV, value);
2147 
2148 	if (!virt_wire_setup) {
2149 		/*
2150 		 * For LVT0 make it edge triggered, active high,
2151 		 * external and enabled
2152 		 */
2153 		value = apic_read(APIC_LVT0);
2154 		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2155 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2156 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2157 		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2158 		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
2159 		apic_write(APIC_LVT0, value);
2160 	} else {
2161 		/* Disable LVT0 */
2162 		apic_write(APIC_LVT0, APIC_LVT_MASKED);
2163 	}
2164 
2165 	/*
2166 	 * For LVT1 make it edge triggered, active high,
2167 	 * nmi and enabled
2168 	 */
2169 	value = apic_read(APIC_LVT1);
2170 	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2171 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2172 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2173 	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2174 	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
2175 	apic_write(APIC_LVT1, value);
2176 }
2177 
2178 /*
2179  * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
2180  * contiguously, it equals to current allocated max logical CPU ID plus 1.
2181  * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
2182  * so the maximum of nr_logical_cpuids is nr_cpu_ids.
2183  *
2184  * NOTE: Reserve 0 for BSP.
2185  */
2186 static int nr_logical_cpuids = 1;
2187 
2188 /*
2189  * Used to store mapping between logical CPU IDs and APIC IDs.
2190  */
2191 static int cpuid_to_apicid[] = {
2192 	[0 ... NR_CPUS - 1] = -1,
2193 };
2194 
2195 /*
2196  * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
2197  * and cpuid_to_apicid[] synchronized.
2198  */
2199 static int allocate_logical_cpuid(int apicid)
2200 {
2201 	int i;
2202 
2203 	/*
2204 	 * cpuid <-> apicid mapping is persistent, so when a cpu is up,
2205 	 * check if the kernel has allocated a cpuid for it.
2206 	 */
2207 	for (i = 0; i < nr_logical_cpuids; i++) {
2208 		if (cpuid_to_apicid[i] == apicid)
2209 			return i;
2210 	}
2211 
2212 	/* Allocate a new cpuid. */
2213 	if (nr_logical_cpuids >= nr_cpu_ids) {
2214 		WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
2215 			     "Processor %d/0x%x and the rest are ignored.\n",
2216 			     nr_cpu_ids, nr_logical_cpuids, apicid);
2217 		return -EINVAL;
2218 	}
2219 
2220 	cpuid_to_apicid[nr_logical_cpuids] = apicid;
2221 	return nr_logical_cpuids++;
2222 }
2223 
2224 int generic_processor_info(int apicid, int version)
2225 {
2226 	int cpu, max = nr_cpu_ids;
2227 	bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
2228 				phys_cpu_present_map);
2229 
2230 	/*
2231 	 * boot_cpu_physical_apicid is designed to have the apicid
2232 	 * returned by read_apic_id(), i.e, the apicid of the
2233 	 * currently booting-up processor. However, on some platforms,
2234 	 * it is temporarily modified by the apicid reported as BSP
2235 	 * through MP table. Concretely:
2236 	 *
2237 	 * - arch/x86/kernel/mpparse.c: MP_processor_info()
2238 	 * - arch/x86/mm/amdtopology.c: amd_numa_init()
2239 	 *
2240 	 * This function is executed with the modified
2241 	 * boot_cpu_physical_apicid. So, disabled_cpu_apicid kernel
2242 	 * parameter doesn't work to disable APs on kdump 2nd kernel.
2243 	 *
2244 	 * Since fixing handling of boot_cpu_physical_apicid requires
2245 	 * another discussion and tests on each platform, we leave it
2246 	 * for now and here we use read_apic_id() directly in this
2247 	 * function, generic_processor_info().
2248 	 */
2249 	if (disabled_cpu_apicid != BAD_APICID &&
2250 	    disabled_cpu_apicid != read_apic_id() &&
2251 	    disabled_cpu_apicid == apicid) {
2252 		int thiscpu = num_processors + disabled_cpus;
2253 
2254 		pr_warning("APIC: Disabling requested cpu."
2255 			   " Processor %d/0x%x ignored.\n",
2256 			   thiscpu, apicid);
2257 
2258 		disabled_cpus++;
2259 		return -ENODEV;
2260 	}
2261 
2262 	/*
2263 	 * If boot cpu has not been detected yet, then only allow upto
2264 	 * nr_cpu_ids - 1 processors and keep one slot free for boot cpu
2265 	 */
2266 	if (!boot_cpu_detected && num_processors >= nr_cpu_ids - 1 &&
2267 	    apicid != boot_cpu_physical_apicid) {
2268 		int thiscpu = max + disabled_cpus - 1;
2269 
2270 		pr_warning(
2271 			"APIC: NR_CPUS/possible_cpus limit of %i almost"
2272 			" reached. Keeping one slot for boot cpu."
2273 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
2274 
2275 		disabled_cpus++;
2276 		return -ENODEV;
2277 	}
2278 
2279 	if (num_processors >= nr_cpu_ids) {
2280 		int thiscpu = max + disabled_cpus;
2281 
2282 		pr_warning("APIC: NR_CPUS/possible_cpus limit of %i "
2283 			   "reached. Processor %d/0x%x ignored.\n",
2284 			   max, thiscpu, apicid);
2285 
2286 		disabled_cpus++;
2287 		return -EINVAL;
2288 	}
2289 
2290 	if (apicid == boot_cpu_physical_apicid) {
2291 		/*
2292 		 * x86_bios_cpu_apicid is required to have processors listed
2293 		 * in same order as logical cpu numbers. Hence the first
2294 		 * entry is BSP, and so on.
2295 		 * boot_cpu_init() already hold bit 0 in cpu_present_mask
2296 		 * for BSP.
2297 		 */
2298 		cpu = 0;
2299 
2300 		/* Logical cpuid 0 is reserved for BSP. */
2301 		cpuid_to_apicid[0] = apicid;
2302 	} else {
2303 		cpu = allocate_logical_cpuid(apicid);
2304 		if (cpu < 0) {
2305 			disabled_cpus++;
2306 			return -EINVAL;
2307 		}
2308 	}
2309 
2310 	/*
2311 	 * Validate version
2312 	 */
2313 	if (version == 0x0) {
2314 		pr_warning("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
2315 			   cpu, apicid);
2316 		version = 0x10;
2317 	}
2318 
2319 	if (version != boot_cpu_apic_version) {
2320 		pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
2321 			boot_cpu_apic_version, cpu, version);
2322 	}
2323 
2324 	if (apicid > max_physical_apicid)
2325 		max_physical_apicid = apicid;
2326 
2327 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
2328 	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
2329 	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
2330 #endif
2331 #ifdef CONFIG_X86_32
2332 	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
2333 		apic->x86_32_early_logical_apicid(cpu);
2334 #endif
2335 	set_cpu_possible(cpu, true);
2336 	physid_set(apicid, phys_cpu_present_map);
2337 	set_cpu_present(cpu, true);
2338 	num_processors++;
2339 
2340 	return cpu;
2341 }
2342 
2343 int hard_smp_processor_id(void)
2344 {
2345 	return read_apic_id();
2346 }
2347 
2348 /*
2349  * Override the generic EOI implementation with an optimized version.
2350  * Only called during early boot when only one CPU is active and with
2351  * interrupts disabled, so we know this does not race with actual APIC driver
2352  * use.
2353  */
2354 void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v))
2355 {
2356 	struct apic **drv;
2357 
2358 	for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
2359 		/* Should happen once for each apic */
2360 		WARN_ON((*drv)->eoi_write == eoi_write);
2361 		(*drv)->native_eoi_write = (*drv)->eoi_write;
2362 		(*drv)->eoi_write = eoi_write;
2363 	}
2364 }
2365 
2366 static void __init apic_bsp_up_setup(void)
2367 {
2368 #ifdef CONFIG_X86_64
2369 	apic_write(APIC_ID, apic->set_apic_id(boot_cpu_physical_apicid));
2370 #else
2371 	/*
2372 	 * Hack: In case of kdump, after a crash, kernel might be booting
2373 	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
2374 	 * might be zero if read from MP tables. Get it from LAPIC.
2375 	 */
2376 # ifdef CONFIG_CRASH_DUMP
2377 	boot_cpu_physical_apicid = read_apic_id();
2378 # endif
2379 #endif
2380 	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
2381 }
2382 
2383 /**
2384  * apic_bsp_setup - Setup function for local apic and io-apic
2385  * @upmode:		Force UP mode (for APIC_init_uniprocessor)
2386  *
2387  * Returns:
2388  * apic_id of BSP APIC
2389  */
2390 void __init apic_bsp_setup(bool upmode)
2391 {
2392 	connect_bsp_APIC();
2393 	if (upmode)
2394 		apic_bsp_up_setup();
2395 	setup_local_APIC();
2396 
2397 	enable_IO_APIC();
2398 	end_local_APIC_setup();
2399 	irq_remap_enable_fault_handling();
2400 	setup_IO_APIC();
2401 }
2402 
2403 #ifdef CONFIG_UP_LATE_INIT
2404 void __init up_late_init(void)
2405 {
2406 	if (apic_intr_mode == APIC_PIC)
2407 		return;
2408 
2409 	/* Setup local timer */
2410 	x86_init.timers.setup_percpu_clockev();
2411 }
2412 #endif
2413 
2414 /*
2415  * Power management
2416  */
2417 #ifdef CONFIG_PM
2418 
2419 static struct {
2420 	/*
2421 	 * 'active' is true if the local APIC was enabled by us and
2422 	 * not the BIOS; this signifies that we are also responsible
2423 	 * for disabling it before entering apm/acpi suspend
2424 	 */
2425 	int active;
2426 	/* r/w apic fields */
2427 	unsigned int apic_id;
2428 	unsigned int apic_taskpri;
2429 	unsigned int apic_ldr;
2430 	unsigned int apic_dfr;
2431 	unsigned int apic_spiv;
2432 	unsigned int apic_lvtt;
2433 	unsigned int apic_lvtpc;
2434 	unsigned int apic_lvt0;
2435 	unsigned int apic_lvt1;
2436 	unsigned int apic_lvterr;
2437 	unsigned int apic_tmict;
2438 	unsigned int apic_tdcr;
2439 	unsigned int apic_thmr;
2440 	unsigned int apic_cmci;
2441 } apic_pm_state;
2442 
2443 static int lapic_suspend(void)
2444 {
2445 	unsigned long flags;
2446 	int maxlvt;
2447 
2448 	if (!apic_pm_state.active)
2449 		return 0;
2450 
2451 	maxlvt = lapic_get_maxlvt();
2452 
2453 	apic_pm_state.apic_id = apic_read(APIC_ID);
2454 	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2455 	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2456 	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2457 	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2458 	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2459 	if (maxlvt >= 4)
2460 		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2461 	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2462 	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2463 	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2464 	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2465 	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2466 #ifdef CONFIG_X86_THERMAL_VECTOR
2467 	if (maxlvt >= 5)
2468 		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2469 #endif
2470 #ifdef CONFIG_X86_MCE_INTEL
2471 	if (maxlvt >= 6)
2472 		apic_pm_state.apic_cmci = apic_read(APIC_LVTCMCI);
2473 #endif
2474 
2475 	local_irq_save(flags);
2476 	disable_local_APIC();
2477 
2478 	irq_remapping_disable();
2479 
2480 	local_irq_restore(flags);
2481 	return 0;
2482 }
2483 
2484 static void lapic_resume(void)
2485 {
2486 	unsigned int l, h;
2487 	unsigned long flags;
2488 	int maxlvt;
2489 
2490 	if (!apic_pm_state.active)
2491 		return;
2492 
2493 	local_irq_save(flags);
2494 
2495 	/*
2496 	 * IO-APIC and PIC have their own resume routines.
2497 	 * We just mask them here to make sure the interrupt
2498 	 * subsystem is completely quiet while we enable x2apic
2499 	 * and interrupt-remapping.
2500 	 */
2501 	mask_ioapic_entries();
2502 	legacy_pic->mask_all();
2503 
2504 	if (x2apic_mode) {
2505 		__x2apic_enable();
2506 	} else {
2507 		/*
2508 		 * Make sure the APICBASE points to the right address
2509 		 *
2510 		 * FIXME! This will be wrong if we ever support suspend on
2511 		 * SMP! We'll need to do this as part of the CPU restore!
2512 		 */
2513 		if (boot_cpu_data.x86 >= 6) {
2514 			rdmsr(MSR_IA32_APICBASE, l, h);
2515 			l &= ~MSR_IA32_APICBASE_BASE;
2516 			l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2517 			wrmsr(MSR_IA32_APICBASE, l, h);
2518 		}
2519 	}
2520 
2521 	maxlvt = lapic_get_maxlvt();
2522 	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2523 	apic_write(APIC_ID, apic_pm_state.apic_id);
2524 	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2525 	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2526 	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2527 	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2528 	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2529 	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2530 #ifdef CONFIG_X86_THERMAL_VECTOR
2531 	if (maxlvt >= 5)
2532 		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2533 #endif
2534 #ifdef CONFIG_X86_MCE_INTEL
2535 	if (maxlvt >= 6)
2536 		apic_write(APIC_LVTCMCI, apic_pm_state.apic_cmci);
2537 #endif
2538 	if (maxlvt >= 4)
2539 		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2540 	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2541 	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2542 	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2543 	apic_write(APIC_ESR, 0);
2544 	apic_read(APIC_ESR);
2545 	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2546 	apic_write(APIC_ESR, 0);
2547 	apic_read(APIC_ESR);
2548 
2549 	irq_remapping_reenable(x2apic_mode);
2550 
2551 	local_irq_restore(flags);
2552 }
2553 
2554 /*
2555  * This device has no shutdown method - fully functioning local APICs
2556  * are needed on every CPU up until machine_halt/restart/poweroff.
2557  */
2558 
2559 static struct syscore_ops lapic_syscore_ops = {
2560 	.resume		= lapic_resume,
2561 	.suspend	= lapic_suspend,
2562 };
2563 
2564 static void apic_pm_activate(void)
2565 {
2566 	apic_pm_state.active = 1;
2567 }
2568 
2569 static int __init init_lapic_sysfs(void)
2570 {
2571 	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2572 	if (boot_cpu_has(X86_FEATURE_APIC))
2573 		register_syscore_ops(&lapic_syscore_ops);
2574 
2575 	return 0;
2576 }
2577 
2578 /* local apic needs to resume before other devices access its registers. */
2579 core_initcall(init_lapic_sysfs);
2580 
2581 #else	/* CONFIG_PM */
2582 
2583 static void apic_pm_activate(void) { }
2584 
2585 #endif	/* CONFIG_PM */
2586 
2587 #ifdef CONFIG_X86_64
2588 
2589 static int multi_checked;
2590 static int multi;
2591 
2592 static int set_multi(const struct dmi_system_id *d)
2593 {
2594 	if (multi)
2595 		return 0;
2596 	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2597 	multi = 1;
2598 	return 0;
2599 }
2600 
2601 static const struct dmi_system_id multi_dmi_table[] = {
2602 	{
2603 		.callback = set_multi,
2604 		.ident = "IBM System Summit2",
2605 		.matches = {
2606 			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2607 			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2608 		},
2609 	},
2610 	{}
2611 };
2612 
2613 static void dmi_check_multi(void)
2614 {
2615 	if (multi_checked)
2616 		return;
2617 
2618 	dmi_check_system(multi_dmi_table);
2619 	multi_checked = 1;
2620 }
2621 
2622 /*
2623  * apic_is_clustered_box() -- Check if we can expect good TSC
2624  *
2625  * Thus far, the major user of this is IBM's Summit2 series:
2626  * Clustered boxes may have unsynced TSC problems if they are
2627  * multi-chassis.
2628  * Use DMI to check them
2629  */
2630 int apic_is_clustered_box(void)
2631 {
2632 	dmi_check_multi();
2633 	return multi;
2634 }
2635 #endif
2636 
2637 /*
2638  * APIC command line parameters
2639  */
2640 static int __init setup_disableapic(char *arg)
2641 {
2642 	disable_apic = 1;
2643 	setup_clear_cpu_cap(X86_FEATURE_APIC);
2644 	return 0;
2645 }
2646 early_param("disableapic", setup_disableapic);
2647 
2648 /* same as disableapic, for compatibility */
2649 static int __init setup_nolapic(char *arg)
2650 {
2651 	return setup_disableapic(arg);
2652 }
2653 early_param("nolapic", setup_nolapic);
2654 
2655 static int __init parse_lapic_timer_c2_ok(char *arg)
2656 {
2657 	local_apic_timer_c2_ok = 1;
2658 	return 0;
2659 }
2660 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2661 
2662 static int __init parse_disable_apic_timer(char *arg)
2663 {
2664 	disable_apic_timer = 1;
2665 	return 0;
2666 }
2667 early_param("noapictimer", parse_disable_apic_timer);
2668 
2669 static int __init parse_nolapic_timer(char *arg)
2670 {
2671 	disable_apic_timer = 1;
2672 	return 0;
2673 }
2674 early_param("nolapic_timer", parse_nolapic_timer);
2675 
2676 static int __init apic_set_verbosity(char *arg)
2677 {
2678 	if (!arg)  {
2679 #ifdef CONFIG_X86_64
2680 		skip_ioapic_setup = 0;
2681 		return 0;
2682 #endif
2683 		return -EINVAL;
2684 	}
2685 
2686 	if (strcmp("debug", arg) == 0)
2687 		apic_verbosity = APIC_DEBUG;
2688 	else if (strcmp("verbose", arg) == 0)
2689 		apic_verbosity = APIC_VERBOSE;
2690 #ifdef CONFIG_X86_64
2691 	else {
2692 		pr_warning("APIC Verbosity level %s not recognised"
2693 			" use apic=verbose or apic=debug\n", arg);
2694 		return -EINVAL;
2695 	}
2696 #endif
2697 
2698 	return 0;
2699 }
2700 early_param("apic", apic_set_verbosity);
2701 
2702 static int __init lapic_insert_resource(void)
2703 {
2704 	if (!apic_phys)
2705 		return -1;
2706 
2707 	/* Put local APIC into the resource map. */
2708 	lapic_resource.start = apic_phys;
2709 	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2710 	insert_resource(&iomem_resource, &lapic_resource);
2711 
2712 	return 0;
2713 }
2714 
2715 /*
2716  * need call insert after e820__reserve_resources()
2717  * that is using request_resource
2718  */
2719 late_initcall(lapic_insert_resource);
2720 
2721 static int __init apic_set_disabled_cpu_apicid(char *arg)
2722 {
2723 	if (!arg || !get_option(&arg, &disabled_cpu_apicid))
2724 		return -EINVAL;
2725 
2726 	return 0;
2727 }
2728 early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);
2729 
2730 static int __init apic_set_extnmi(char *arg)
2731 {
2732 	if (!arg)
2733 		return -EINVAL;
2734 
2735 	if (!strncmp("all", arg, 3))
2736 		apic_extnmi = APIC_EXTNMI_ALL;
2737 	else if (!strncmp("none", arg, 4))
2738 		apic_extnmi = APIC_EXTNMI_NONE;
2739 	else if (!strncmp("bsp", arg, 3))
2740 		apic_extnmi = APIC_EXTNMI_BSP;
2741 	else {
2742 		pr_warn("Unknown external NMI delivery mode `%s' ignored\n", arg);
2743 		return -EINVAL;
2744 	}
2745 
2746 	return 0;
2747 }
2748 early_param("apic_extnmi", apic_set_extnmi);
2749