xref: /openbmc/linux/arch/x86/kernel/apic/apic.c (revision 9be08a27)
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 #include <asm/irq_regs.h>
60 
61 unsigned int num_processors;
62 
63 unsigned disabled_cpus;
64 
65 /* Processor that is doing the boot up */
66 unsigned int boot_cpu_physical_apicid = -1U;
67 EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
68 
69 u8 boot_cpu_apic_version;
70 
71 /*
72  * The highest APIC ID seen during enumeration.
73  */
74 static unsigned int max_physical_apicid;
75 
76 /*
77  * Bitmask of physically existing CPUs:
78  */
79 physid_mask_t phys_cpu_present_map;
80 
81 /*
82  * Processor to be disabled specified by kernel parameter
83  * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
84  * avoid undefined behaviour caused by sending INIT from AP to BSP.
85  */
86 static unsigned int disabled_cpu_apicid __read_mostly = BAD_APICID;
87 
88 /*
89  * This variable controls which CPUs receive external NMIs.  By default,
90  * external NMIs are delivered only to the BSP.
91  */
92 static int apic_extnmi = APIC_EXTNMI_BSP;
93 
94 /*
95  * Map cpu index to physical APIC ID
96  */
97 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid, BAD_APICID);
98 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_bios_cpu_apicid, BAD_APICID);
99 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, U32_MAX);
100 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
101 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
102 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
103 
104 #ifdef CONFIG_X86_32
105 
106 /*
107  * On x86_32, the mapping between cpu and logical apicid may vary
108  * depending on apic in use.  The following early percpu variable is
109  * used for the mapping.  This is where the behaviors of x86_64 and 32
110  * actually diverge.  Let's keep it ugly for now.
111  */
112 DEFINE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid, BAD_APICID);
113 
114 /* Local APIC was disabled by the BIOS and enabled by the kernel */
115 static int enabled_via_apicbase;
116 
117 /*
118  * Handle interrupt mode configuration register (IMCR).
119  * This register controls whether the interrupt signals
120  * that reach the BSP come from the master PIC or from the
121  * local APIC. Before entering Symmetric I/O Mode, either
122  * the BIOS or the operating system must switch out of
123  * PIC Mode by changing the IMCR.
124  */
125 static inline void imcr_pic_to_apic(void)
126 {
127 	/* select IMCR register */
128 	outb(0x70, 0x22);
129 	/* NMI and 8259 INTR go through APIC */
130 	outb(0x01, 0x23);
131 }
132 
133 static inline void imcr_apic_to_pic(void)
134 {
135 	/* select IMCR register */
136 	outb(0x70, 0x22);
137 	/* NMI and 8259 INTR go directly to BSP */
138 	outb(0x00, 0x23);
139 }
140 #endif
141 
142 /*
143  * Knob to control our willingness to enable the local APIC.
144  *
145  * +1=force-enable
146  */
147 static int force_enable_local_apic __initdata;
148 
149 /*
150  * APIC command line parameters
151  */
152 static int __init parse_lapic(char *arg)
153 {
154 	if (IS_ENABLED(CONFIG_X86_32) && !arg)
155 		force_enable_local_apic = 1;
156 	else if (arg && !strncmp(arg, "notscdeadline", 13))
157 		setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
158 	return 0;
159 }
160 early_param("lapic", parse_lapic);
161 
162 #ifdef CONFIG_X86_64
163 static int apic_calibrate_pmtmr __initdata;
164 static __init int setup_apicpmtimer(char *s)
165 {
166 	apic_calibrate_pmtmr = 1;
167 	notsc_setup(NULL);
168 	return 0;
169 }
170 __setup("apicpmtimer", setup_apicpmtimer);
171 #endif
172 
173 unsigned long mp_lapic_addr;
174 int disable_apic;
175 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
176 static int disable_apic_timer __initdata;
177 /* Local APIC timer works in C2 */
178 int local_apic_timer_c2_ok;
179 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
180 
181 /*
182  * Debug level, exported for io_apic.c
183  */
184 unsigned int apic_verbosity;
185 
186 int pic_mode;
187 
188 /* Have we found an MP table */
189 int smp_found_config;
190 
191 static struct resource lapic_resource = {
192 	.name = "Local APIC",
193 	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
194 };
195 
196 unsigned int lapic_timer_frequency = 0;
197 
198 static void apic_pm_activate(void);
199 
200 static unsigned long apic_phys;
201 
202 /*
203  * Get the LAPIC version
204  */
205 static inline int lapic_get_version(void)
206 {
207 	return GET_APIC_VERSION(apic_read(APIC_LVR));
208 }
209 
210 /*
211  * Check, if the APIC is integrated or a separate chip
212  */
213 static inline int lapic_is_integrated(void)
214 {
215 	return APIC_INTEGRATED(lapic_get_version());
216 }
217 
218 /*
219  * Check, whether this is a modern or a first generation APIC
220  */
221 static int modern_apic(void)
222 {
223 	/* AMD systems use old APIC versions, so check the CPU */
224 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
225 	    boot_cpu_data.x86 >= 0xf)
226 		return 1;
227 	return lapic_get_version() >= 0x14;
228 }
229 
230 /*
231  * right after this call apic become NOOP driven
232  * so apic->write/read doesn't do anything
233  */
234 static void __init apic_disable(void)
235 {
236 	pr_info("APIC: switched to apic NOOP\n");
237 	apic = &apic_noop;
238 }
239 
240 void native_apic_wait_icr_idle(void)
241 {
242 	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
243 		cpu_relax();
244 }
245 
246 u32 native_safe_apic_wait_icr_idle(void)
247 {
248 	u32 send_status;
249 	int timeout;
250 
251 	timeout = 0;
252 	do {
253 		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
254 		if (!send_status)
255 			break;
256 		inc_irq_stat(icr_read_retry_count);
257 		udelay(100);
258 	} while (timeout++ < 1000);
259 
260 	return send_status;
261 }
262 
263 void native_apic_icr_write(u32 low, u32 id)
264 {
265 	unsigned long flags;
266 
267 	local_irq_save(flags);
268 	apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
269 	apic_write(APIC_ICR, low);
270 	local_irq_restore(flags);
271 }
272 
273 u64 native_apic_icr_read(void)
274 {
275 	u32 icr1, icr2;
276 
277 	icr2 = apic_read(APIC_ICR2);
278 	icr1 = apic_read(APIC_ICR);
279 
280 	return icr1 | ((u64)icr2 << 32);
281 }
282 
283 #ifdef CONFIG_X86_32
284 /**
285  * get_physical_broadcast - Get number of physical broadcast IDs
286  */
287 int get_physical_broadcast(void)
288 {
289 	return modern_apic() ? 0xff : 0xf;
290 }
291 #endif
292 
293 /**
294  * lapic_get_maxlvt - get the maximum number of local vector table entries
295  */
296 int lapic_get_maxlvt(void)
297 {
298 	/*
299 	 * - we always have APIC integrated on 64bit mode
300 	 * - 82489DXs do not report # of LVT entries
301 	 */
302 	return lapic_is_integrated() ? GET_APIC_MAXLVT(apic_read(APIC_LVR)) : 2;
303 }
304 
305 /*
306  * Local APIC timer
307  */
308 
309 /* Clock divisor */
310 #define APIC_DIVISOR 16
311 #define TSC_DIVISOR  8
312 
313 /*
314  * This function sets up the local APIC timer, with a timeout of
315  * 'clocks' APIC bus clock. During calibration we actually call
316  * this function twice on the boot CPU, once with a bogus timeout
317  * value, second time for real. The other (noncalibrating) CPUs
318  * call this function only once, with the real, calibrated value.
319  *
320  * We do reads before writes even if unnecessary, to get around the
321  * P5 APIC double write bug.
322  */
323 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
324 {
325 	unsigned int lvtt_value, tmp_value;
326 
327 	lvtt_value = LOCAL_TIMER_VECTOR;
328 	if (!oneshot)
329 		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
330 	else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
331 		lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE;
332 
333 	if (!lapic_is_integrated())
334 		lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
335 
336 	if (!irqen)
337 		lvtt_value |= APIC_LVT_MASKED;
338 
339 	apic_write(APIC_LVTT, lvtt_value);
340 
341 	if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) {
342 		/*
343 		 * See Intel SDM: TSC-Deadline Mode chapter. In xAPIC mode,
344 		 * writing to the APIC LVTT and TSC_DEADLINE MSR isn't serialized.
345 		 * According to Intel, MFENCE can do the serialization here.
346 		 */
347 		asm volatile("mfence" : : : "memory");
348 
349 		printk_once(KERN_DEBUG "TSC deadline timer enabled\n");
350 		return;
351 	}
352 
353 	/*
354 	 * Divide PICLK by 16
355 	 */
356 	tmp_value = apic_read(APIC_TDCR);
357 	apic_write(APIC_TDCR,
358 		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
359 		APIC_TDR_DIV_16);
360 
361 	if (!oneshot)
362 		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
363 }
364 
365 /*
366  * Setup extended LVT, AMD specific
367  *
368  * Software should use the LVT offsets the BIOS provides.  The offsets
369  * are determined by the subsystems using it like those for MCE
370  * threshold or IBS.  On K8 only offset 0 (APIC500) and MCE interrupts
371  * are supported. Beginning with family 10h at least 4 offsets are
372  * available.
373  *
374  * Since the offsets must be consistent for all cores, we keep track
375  * of the LVT offsets in software and reserve the offset for the same
376  * vector also to be used on other cores. An offset is freed by
377  * setting the entry to APIC_EILVT_MASKED.
378  *
379  * If the BIOS is right, there should be no conflicts. Otherwise a
380  * "[Firmware Bug]: ..." error message is generated. However, if
381  * software does not properly determines the offsets, it is not
382  * necessarily a BIOS bug.
383  */
384 
385 static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
386 
387 static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
388 {
389 	return (old & APIC_EILVT_MASKED)
390 		|| (new == APIC_EILVT_MASKED)
391 		|| ((new & ~APIC_EILVT_MASKED) == old);
392 }
393 
394 static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
395 {
396 	unsigned int rsvd, vector;
397 
398 	if (offset >= APIC_EILVT_NR_MAX)
399 		return ~0;
400 
401 	rsvd = atomic_read(&eilvt_offsets[offset]);
402 	do {
403 		vector = rsvd & ~APIC_EILVT_MASKED;	/* 0: unassigned */
404 		if (vector && !eilvt_entry_is_changeable(vector, new))
405 			/* may not change if vectors are different */
406 			return rsvd;
407 		rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new);
408 	} while (rsvd != new);
409 
410 	rsvd &= ~APIC_EILVT_MASKED;
411 	if (rsvd && rsvd != vector)
412 		pr_info("LVT offset %d assigned for vector 0x%02x\n",
413 			offset, rsvd);
414 
415 	return new;
416 }
417 
418 /*
419  * If mask=1, the LVT entry does not generate interrupts while mask=0
420  * enables the vector. See also the BKDGs. Must be called with
421  * preemption disabled.
422  */
423 
424 int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
425 {
426 	unsigned long reg = APIC_EILVTn(offset);
427 	unsigned int new, old, reserved;
428 
429 	new = (mask << 16) | (msg_type << 8) | vector;
430 	old = apic_read(reg);
431 	reserved = reserve_eilvt_offset(offset, new);
432 
433 	if (reserved != new) {
434 		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
435 		       "vector 0x%x, but the register is already in use for "
436 		       "vector 0x%x on another cpu\n",
437 		       smp_processor_id(), reg, offset, new, reserved);
438 		return -EINVAL;
439 	}
440 
441 	if (!eilvt_entry_is_changeable(old, new)) {
442 		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
443 		       "vector 0x%x, but the register is already in use for "
444 		       "vector 0x%x on this cpu\n",
445 		       smp_processor_id(), reg, offset, new, old);
446 		return -EBUSY;
447 	}
448 
449 	apic_write(reg, new);
450 
451 	return 0;
452 }
453 EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
454 
455 /*
456  * Program the next event, relative to now
457  */
458 static int lapic_next_event(unsigned long delta,
459 			    struct clock_event_device *evt)
460 {
461 	apic_write(APIC_TMICT, delta);
462 	return 0;
463 }
464 
465 static int lapic_next_deadline(unsigned long delta,
466 			       struct clock_event_device *evt)
467 {
468 	u64 tsc;
469 
470 	tsc = rdtsc();
471 	wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR));
472 	return 0;
473 }
474 
475 static int lapic_timer_shutdown(struct clock_event_device *evt)
476 {
477 	unsigned int v;
478 
479 	/* Lapic used as dummy for broadcast ? */
480 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
481 		return 0;
482 
483 	v = apic_read(APIC_LVTT);
484 	v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
485 	apic_write(APIC_LVTT, v);
486 	apic_write(APIC_TMICT, 0);
487 	return 0;
488 }
489 
490 static inline int
491 lapic_timer_set_periodic_oneshot(struct clock_event_device *evt, bool oneshot)
492 {
493 	/* Lapic used as dummy for broadcast ? */
494 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
495 		return 0;
496 
497 	__setup_APIC_LVTT(lapic_timer_frequency, oneshot, 1);
498 	return 0;
499 }
500 
501 static int lapic_timer_set_periodic(struct clock_event_device *evt)
502 {
503 	return lapic_timer_set_periodic_oneshot(evt, false);
504 }
505 
506 static int lapic_timer_set_oneshot(struct clock_event_device *evt)
507 {
508 	return lapic_timer_set_periodic_oneshot(evt, true);
509 }
510 
511 /*
512  * Local APIC timer broadcast function
513  */
514 static void lapic_timer_broadcast(const struct cpumask *mask)
515 {
516 #ifdef CONFIG_SMP
517 	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
518 #endif
519 }
520 
521 
522 /*
523  * The local apic timer can be used for any function which is CPU local.
524  */
525 static struct clock_event_device lapic_clockevent = {
526 	.name				= "lapic",
527 	.features			= CLOCK_EVT_FEAT_PERIODIC |
528 					  CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP
529 					  | CLOCK_EVT_FEAT_DUMMY,
530 	.shift				= 32,
531 	.set_state_shutdown		= lapic_timer_shutdown,
532 	.set_state_periodic		= lapic_timer_set_periodic,
533 	.set_state_oneshot		= lapic_timer_set_oneshot,
534 	.set_state_oneshot_stopped	= lapic_timer_shutdown,
535 	.set_next_event			= lapic_next_event,
536 	.broadcast			= lapic_timer_broadcast,
537 	.rating				= 100,
538 	.irq				= -1,
539 };
540 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
541 
542 #define DEADLINE_MODEL_MATCH_FUNC(model, func)	\
543 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&func }
544 
545 #define DEADLINE_MODEL_MATCH_REV(model, rev)	\
546 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)rev }
547 
548 static u32 hsx_deadline_rev(void)
549 {
550 	switch (boot_cpu_data.x86_stepping) {
551 	case 0x02: return 0x3a; /* EP */
552 	case 0x04: return 0x0f; /* EX */
553 	}
554 
555 	return ~0U;
556 }
557 
558 static u32 bdx_deadline_rev(void)
559 {
560 	switch (boot_cpu_data.x86_stepping) {
561 	case 0x02: return 0x00000011;
562 	case 0x03: return 0x0700000e;
563 	case 0x04: return 0x0f00000c;
564 	case 0x05: return 0x0e000003;
565 	}
566 
567 	return ~0U;
568 }
569 
570 static u32 skx_deadline_rev(void)
571 {
572 	switch (boot_cpu_data.x86_stepping) {
573 	case 0x03: return 0x01000136;
574 	case 0x04: return 0x02000014;
575 	}
576 
577 	if (boot_cpu_data.x86_stepping > 4)
578 		return 0;
579 
580 	return ~0U;
581 }
582 
583 static const struct x86_cpu_id deadline_match[] = {
584 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_HASWELL_X,	hsx_deadline_rev),
585 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_X,	0x0b000020),
586 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_BROADWELL_XEON_D,	bdx_deadline_rev),
587 	DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_SKYLAKE_X,	skx_deadline_rev),
588 
589 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_CORE,	0x22),
590 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_ULT,	0x20),
591 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_GT3E,	0x17),
592 
593 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_CORE,	0x25),
594 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_GT3E,	0x17),
595 
596 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_MOBILE,	0xb2),
597 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_DESKTOP,	0xb2),
598 
599 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_MOBILE,	0x52),
600 	DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_DESKTOP,	0x52),
601 
602 	{},
603 };
604 
605 static void apic_check_deadline_errata(void)
606 {
607 	const struct x86_cpu_id *m;
608 	u32 rev;
609 
610 	if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER) ||
611 	    boot_cpu_has(X86_FEATURE_HYPERVISOR))
612 		return;
613 
614 	m = x86_match_cpu(deadline_match);
615 	if (!m)
616 		return;
617 
618 	/*
619 	 * Function pointers will have the MSB set due to address layout,
620 	 * immediate revisions will not.
621 	 */
622 	if ((long)m->driver_data < 0)
623 		rev = ((u32 (*)(void))(m->driver_data))();
624 	else
625 		rev = (u32)m->driver_data;
626 
627 	if (boot_cpu_data.microcode >= rev)
628 		return;
629 
630 	setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
631 	pr_err(FW_BUG "TSC_DEADLINE disabled due to Errata; "
632 	       "please update microcode to version: 0x%x (or later)\n", rev);
633 }
634 
635 /*
636  * Setup the local APIC timer for this CPU. Copy the initialized values
637  * of the boot CPU and register the clock event in the framework.
638  */
639 static void setup_APIC_timer(void)
640 {
641 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
642 
643 	if (this_cpu_has(X86_FEATURE_ARAT)) {
644 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
645 		/* Make LAPIC timer preferrable over percpu HPET */
646 		lapic_clockevent.rating = 150;
647 	}
648 
649 	memcpy(levt, &lapic_clockevent, sizeof(*levt));
650 	levt->cpumask = cpumask_of(smp_processor_id());
651 
652 	if (this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
653 		levt->name = "lapic-deadline";
654 		levt->features &= ~(CLOCK_EVT_FEAT_PERIODIC |
655 				    CLOCK_EVT_FEAT_DUMMY);
656 		levt->set_next_event = lapic_next_deadline;
657 		clockevents_config_and_register(levt,
658 						tsc_khz * (1000 / TSC_DIVISOR),
659 						0xF, ~0UL);
660 	} else
661 		clockevents_register_device(levt);
662 }
663 
664 /*
665  * Install the updated TSC frequency from recalibration at the TSC
666  * deadline clockevent devices.
667  */
668 static void __lapic_update_tsc_freq(void *info)
669 {
670 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
671 
672 	if (!this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
673 		return;
674 
675 	clockevents_update_freq(levt, tsc_khz * (1000 / TSC_DIVISOR));
676 }
677 
678 void lapic_update_tsc_freq(void)
679 {
680 	/*
681 	 * The clockevent device's ->mult and ->shift can both be
682 	 * changed. In order to avoid races, schedule the frequency
683 	 * update code on each CPU.
684 	 */
685 	on_each_cpu(__lapic_update_tsc_freq, NULL, 0);
686 }
687 
688 /*
689  * In this functions we calibrate APIC bus clocks to the external timer.
690  *
691  * We want to do the calibration only once since we want to have local timer
692  * irqs syncron. CPUs connected by the same APIC bus have the very same bus
693  * frequency.
694  *
695  * This was previously done by reading the PIT/HPET and waiting for a wrap
696  * around to find out, that a tick has elapsed. I have a box, where the PIT
697  * readout is broken, so it never gets out of the wait loop again. This was
698  * also reported by others.
699  *
700  * Monitoring the jiffies value is inaccurate and the clockevents
701  * infrastructure allows us to do a simple substitution of the interrupt
702  * handler.
703  *
704  * The calibration routine also uses the pm_timer when possible, as the PIT
705  * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
706  * back to normal later in the boot process).
707  */
708 
709 #define LAPIC_CAL_LOOPS		(HZ/10)
710 
711 static __initdata int lapic_cal_loops = -1;
712 static __initdata long lapic_cal_t1, lapic_cal_t2;
713 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
714 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
715 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
716 
717 /*
718  * Temporary interrupt handler.
719  */
720 static void __init lapic_cal_handler(struct clock_event_device *dev)
721 {
722 	unsigned long long tsc = 0;
723 	long tapic = apic_read(APIC_TMCCT);
724 	unsigned long pm = acpi_pm_read_early();
725 
726 	if (boot_cpu_has(X86_FEATURE_TSC))
727 		tsc = rdtsc();
728 
729 	switch (lapic_cal_loops++) {
730 	case 0:
731 		lapic_cal_t1 = tapic;
732 		lapic_cal_tsc1 = tsc;
733 		lapic_cal_pm1 = pm;
734 		lapic_cal_j1 = jiffies;
735 		break;
736 
737 	case LAPIC_CAL_LOOPS:
738 		lapic_cal_t2 = tapic;
739 		lapic_cal_tsc2 = tsc;
740 		if (pm < lapic_cal_pm1)
741 			pm += ACPI_PM_OVRRUN;
742 		lapic_cal_pm2 = pm;
743 		lapic_cal_j2 = jiffies;
744 		break;
745 	}
746 }
747 
748 static int __init
749 calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
750 {
751 	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
752 	const long pm_thresh = pm_100ms / 100;
753 	unsigned long mult;
754 	u64 res;
755 
756 #ifndef CONFIG_X86_PM_TIMER
757 	return -1;
758 #endif
759 
760 	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
761 
762 	/* Check, if the PM timer is available */
763 	if (!deltapm)
764 		return -1;
765 
766 	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
767 
768 	if (deltapm > (pm_100ms - pm_thresh) &&
769 	    deltapm < (pm_100ms + pm_thresh)) {
770 		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
771 		return 0;
772 	}
773 
774 	res = (((u64)deltapm) *  mult) >> 22;
775 	do_div(res, 1000000);
776 	pr_warning("APIC calibration not consistent "
777 		   "with PM-Timer: %ldms instead of 100ms\n",(long)res);
778 
779 	/* Correct the lapic counter value */
780 	res = (((u64)(*delta)) * pm_100ms);
781 	do_div(res, deltapm);
782 	pr_info("APIC delta adjusted to PM-Timer: "
783 		"%lu (%ld)\n", (unsigned long)res, *delta);
784 	*delta = (long)res;
785 
786 	/* Correct the tsc counter value */
787 	if (boot_cpu_has(X86_FEATURE_TSC)) {
788 		res = (((u64)(*deltatsc)) * pm_100ms);
789 		do_div(res, deltapm);
790 		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
791 					  "PM-Timer: %lu (%ld)\n",
792 					(unsigned long)res, *deltatsc);
793 		*deltatsc = (long)res;
794 	}
795 
796 	return 0;
797 }
798 
799 static int __init calibrate_APIC_clock(void)
800 {
801 	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
802 	void (*real_handler)(struct clock_event_device *dev);
803 	unsigned long deltaj;
804 	long delta, deltatsc;
805 	int pm_referenced = 0;
806 
807 	/**
808 	 * check if lapic timer has already been calibrated by platform
809 	 * specific routine, such as tsc calibration code. if so, we just fill
810 	 * in the clockevent structure and return.
811 	 */
812 
813 	if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
814 		return 0;
815 	} else if (lapic_timer_frequency) {
816 		apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
817 				lapic_timer_frequency);
818 		lapic_clockevent.mult = div_sc(lapic_timer_frequency/APIC_DIVISOR,
819 					TICK_NSEC, lapic_clockevent.shift);
820 		lapic_clockevent.max_delta_ns =
821 			clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
822 		lapic_clockevent.max_delta_ticks = 0x7FFFFF;
823 		lapic_clockevent.min_delta_ns =
824 			clockevent_delta2ns(0xF, &lapic_clockevent);
825 		lapic_clockevent.min_delta_ticks = 0xF;
826 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
827 		return 0;
828 	}
829 
830 	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
831 		    "calibrating APIC timer ...\n");
832 
833 	local_irq_disable();
834 
835 	/* Replace the global interrupt handler */
836 	real_handler = global_clock_event->event_handler;
837 	global_clock_event->event_handler = lapic_cal_handler;
838 
839 	/*
840 	 * Setup the APIC counter to maximum. There is no way the lapic
841 	 * can underflow in the 100ms detection time frame
842 	 */
843 	__setup_APIC_LVTT(0xffffffff, 0, 0);
844 
845 	/* Let the interrupts run */
846 	local_irq_enable();
847 
848 	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
849 		cpu_relax();
850 
851 	local_irq_disable();
852 
853 	/* Restore the real event handler */
854 	global_clock_event->event_handler = real_handler;
855 
856 	/* Build delta t1-t2 as apic timer counts down */
857 	delta = lapic_cal_t1 - lapic_cal_t2;
858 	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
859 
860 	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
861 
862 	/* we trust the PM based calibration if possible */
863 	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
864 					&delta, &deltatsc);
865 
866 	/* Calculate the scaled math multiplication factor */
867 	lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
868 				       lapic_clockevent.shift);
869 	lapic_clockevent.max_delta_ns =
870 		clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
871 	lapic_clockevent.max_delta_ticks = 0x7FFFFFFF;
872 	lapic_clockevent.min_delta_ns =
873 		clockevent_delta2ns(0xF, &lapic_clockevent);
874 	lapic_clockevent.min_delta_ticks = 0xF;
875 
876 	lapic_timer_frequency = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
877 
878 	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
879 	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
880 	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
881 		    lapic_timer_frequency);
882 
883 	if (boot_cpu_has(X86_FEATURE_TSC)) {
884 		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
885 			    "%ld.%04ld MHz.\n",
886 			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
887 			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
888 	}
889 
890 	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
891 		    "%u.%04u MHz.\n",
892 		    lapic_timer_frequency / (1000000 / HZ),
893 		    lapic_timer_frequency % (1000000 / HZ));
894 
895 	/*
896 	 * Do a sanity check on the APIC calibration result
897 	 */
898 	if (lapic_timer_frequency < (1000000 / HZ)) {
899 		local_irq_enable();
900 		pr_warning("APIC frequency too slow, disabling apic timer\n");
901 		return -1;
902 	}
903 
904 	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
905 
906 	/*
907 	 * PM timer calibration failed or not turned on
908 	 * so lets try APIC timer based calibration
909 	 */
910 	if (!pm_referenced) {
911 		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
912 
913 		/*
914 		 * Setup the apic timer manually
915 		 */
916 		levt->event_handler = lapic_cal_handler;
917 		lapic_timer_set_periodic(levt);
918 		lapic_cal_loops = -1;
919 
920 		/* Let the interrupts run */
921 		local_irq_enable();
922 
923 		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
924 			cpu_relax();
925 
926 		/* Stop the lapic timer */
927 		local_irq_disable();
928 		lapic_timer_shutdown(levt);
929 
930 		/* Jiffies delta */
931 		deltaj = lapic_cal_j2 - lapic_cal_j1;
932 		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
933 
934 		/* Check, if the jiffies result is consistent */
935 		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
936 			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
937 		else
938 			levt->features |= CLOCK_EVT_FEAT_DUMMY;
939 	}
940 	local_irq_enable();
941 
942 	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
943 		pr_warning("APIC timer disabled due to verification failure\n");
944 		return -1;
945 	}
946 
947 	return 0;
948 }
949 
950 /*
951  * Setup the boot APIC
952  *
953  * Calibrate and verify the result.
954  */
955 void __init setup_boot_APIC_clock(void)
956 {
957 	/*
958 	 * The local apic timer can be disabled via the kernel
959 	 * commandline or from the CPU detection code. Register the lapic
960 	 * timer as a dummy clock event source on SMP systems, so the
961 	 * broadcast mechanism is used. On UP systems simply ignore it.
962 	 */
963 	if (disable_apic_timer) {
964 		pr_info("Disabling APIC timer\n");
965 		/* No broadcast on UP ! */
966 		if (num_possible_cpus() > 1) {
967 			lapic_clockevent.mult = 1;
968 			setup_APIC_timer();
969 		}
970 		return;
971 	}
972 
973 	if (calibrate_APIC_clock()) {
974 		/* No broadcast on UP ! */
975 		if (num_possible_cpus() > 1)
976 			setup_APIC_timer();
977 		return;
978 	}
979 
980 	/*
981 	 * If nmi_watchdog is set to IO_APIC, we need the
982 	 * PIT/HPET going.  Otherwise register lapic as a dummy
983 	 * device.
984 	 */
985 	lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
986 
987 	/* Setup the lapic or request the broadcast */
988 	setup_APIC_timer();
989 	amd_e400_c1e_apic_setup();
990 }
991 
992 void setup_secondary_APIC_clock(void)
993 {
994 	setup_APIC_timer();
995 	amd_e400_c1e_apic_setup();
996 }
997 
998 /*
999  * The guts of the apic timer interrupt
1000  */
1001 static void local_apic_timer_interrupt(void)
1002 {
1003 	struct clock_event_device *evt = this_cpu_ptr(&lapic_events);
1004 
1005 	/*
1006 	 * Normally we should not be here till LAPIC has been initialized but
1007 	 * in some cases like kdump, its possible that there is a pending LAPIC
1008 	 * timer interrupt from previous kernel's context and is delivered in
1009 	 * new kernel the moment interrupts are enabled.
1010 	 *
1011 	 * Interrupts are enabled early and LAPIC is setup much later, hence
1012 	 * its possible that when we get here evt->event_handler is NULL.
1013 	 * Check for event_handler being NULL and discard the interrupt as
1014 	 * spurious.
1015 	 */
1016 	if (!evt->event_handler) {
1017 		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n",
1018 			   smp_processor_id());
1019 		/* Switch it off */
1020 		lapic_timer_shutdown(evt);
1021 		return;
1022 	}
1023 
1024 	/*
1025 	 * the NMI deadlock-detector uses this.
1026 	 */
1027 	inc_irq_stat(apic_timer_irqs);
1028 
1029 	evt->event_handler(evt);
1030 }
1031 
1032 /*
1033  * Local APIC timer interrupt. This is the most natural way for doing
1034  * local interrupts, but local timer interrupts can be emulated by
1035  * broadcast interrupts too. [in case the hw doesn't support APIC timers]
1036  *
1037  * [ if a single-CPU system runs an SMP kernel then we call the local
1038  *   interrupt as well. Thus we cannot inline the local irq ... ]
1039  */
1040 __visible void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
1041 {
1042 	struct pt_regs *old_regs = set_irq_regs(regs);
1043 
1044 	/*
1045 	 * NOTE! We'd better ACK the irq immediately,
1046 	 * because timer handling can be slow.
1047 	 *
1048 	 * update_process_times() expects us to have done irq_enter().
1049 	 * Besides, if we don't timer interrupts ignore the global
1050 	 * interrupt lock, which is the WrongThing (tm) to do.
1051 	 */
1052 	entering_ack_irq();
1053 	trace_local_timer_entry(LOCAL_TIMER_VECTOR);
1054 	local_apic_timer_interrupt();
1055 	trace_local_timer_exit(LOCAL_TIMER_VECTOR);
1056 	exiting_irq();
1057 
1058 	set_irq_regs(old_regs);
1059 }
1060 
1061 int setup_profiling_timer(unsigned int multiplier)
1062 {
1063 	return -EINVAL;
1064 }
1065 
1066 /*
1067  * Local APIC start and shutdown
1068  */
1069 
1070 /**
1071  * clear_local_APIC - shutdown the local APIC
1072  *
1073  * This is called, when a CPU is disabled and before rebooting, so the state of
1074  * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
1075  * leftovers during boot.
1076  */
1077 void clear_local_APIC(void)
1078 {
1079 	int maxlvt;
1080 	u32 v;
1081 
1082 	/* APIC hasn't been mapped yet */
1083 	if (!x2apic_mode && !apic_phys)
1084 		return;
1085 
1086 	maxlvt = lapic_get_maxlvt();
1087 	/*
1088 	 * Masking an LVT entry can trigger a local APIC error
1089 	 * if the vector is zero. Mask LVTERR first to prevent this.
1090 	 */
1091 	if (maxlvt >= 3) {
1092 		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
1093 		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
1094 	}
1095 	/*
1096 	 * Careful: we have to set masks only first to deassert
1097 	 * any level-triggered sources.
1098 	 */
1099 	v = apic_read(APIC_LVTT);
1100 	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
1101 	v = apic_read(APIC_LVT0);
1102 	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
1103 	v = apic_read(APIC_LVT1);
1104 	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
1105 	if (maxlvt >= 4) {
1106 		v = apic_read(APIC_LVTPC);
1107 		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
1108 	}
1109 
1110 	/* lets not touch this if we didn't frob it */
1111 #ifdef CONFIG_X86_THERMAL_VECTOR
1112 	if (maxlvt >= 5) {
1113 		v = apic_read(APIC_LVTTHMR);
1114 		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
1115 	}
1116 #endif
1117 #ifdef CONFIG_X86_MCE_INTEL
1118 	if (maxlvt >= 6) {
1119 		v = apic_read(APIC_LVTCMCI);
1120 		if (!(v & APIC_LVT_MASKED))
1121 			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
1122 	}
1123 #endif
1124 
1125 	/*
1126 	 * Clean APIC state for other OSs:
1127 	 */
1128 	apic_write(APIC_LVTT, APIC_LVT_MASKED);
1129 	apic_write(APIC_LVT0, APIC_LVT_MASKED);
1130 	apic_write(APIC_LVT1, APIC_LVT_MASKED);
1131 	if (maxlvt >= 3)
1132 		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
1133 	if (maxlvt >= 4)
1134 		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
1135 
1136 	/* Integrated APIC (!82489DX) ? */
1137 	if (lapic_is_integrated()) {
1138 		if (maxlvt > 3)
1139 			/* Clear ESR due to Pentium errata 3AP and 11AP */
1140 			apic_write(APIC_ESR, 0);
1141 		apic_read(APIC_ESR);
1142 	}
1143 }
1144 
1145 /**
1146  * disable_local_APIC - clear and disable the local APIC
1147  */
1148 void disable_local_APIC(void)
1149 {
1150 	unsigned int value;
1151 
1152 	/* APIC hasn't been mapped yet */
1153 	if (!x2apic_mode && !apic_phys)
1154 		return;
1155 
1156 	clear_local_APIC();
1157 
1158 	/*
1159 	 * Disable APIC (implies clearing of registers
1160 	 * for 82489DX!).
1161 	 */
1162 	value = apic_read(APIC_SPIV);
1163 	value &= ~APIC_SPIV_APIC_ENABLED;
1164 	apic_write(APIC_SPIV, value);
1165 
1166 #ifdef CONFIG_X86_32
1167 	/*
1168 	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
1169 	 * restore the disabled state.
1170 	 */
1171 	if (enabled_via_apicbase) {
1172 		unsigned int l, h;
1173 
1174 		rdmsr(MSR_IA32_APICBASE, l, h);
1175 		l &= ~MSR_IA32_APICBASE_ENABLE;
1176 		wrmsr(MSR_IA32_APICBASE, l, h);
1177 	}
1178 #endif
1179 }
1180 
1181 /*
1182  * If Linux enabled the LAPIC against the BIOS default disable it down before
1183  * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
1184  * not power-off.  Additionally clear all LVT entries before disable_local_APIC
1185  * for the case where Linux didn't enable the LAPIC.
1186  */
1187 void lapic_shutdown(void)
1188 {
1189 	unsigned long flags;
1190 
1191 	if (!boot_cpu_has(X86_FEATURE_APIC) && !apic_from_smp_config())
1192 		return;
1193 
1194 	local_irq_save(flags);
1195 
1196 #ifdef CONFIG_X86_32
1197 	if (!enabled_via_apicbase)
1198 		clear_local_APIC();
1199 	else
1200 #endif
1201 		disable_local_APIC();
1202 
1203 
1204 	local_irq_restore(flags);
1205 }
1206 
1207 /**
1208  * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1209  */
1210 void __init sync_Arb_IDs(void)
1211 {
1212 	/*
1213 	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1214 	 * needed on AMD.
1215 	 */
1216 	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1217 		return;
1218 
1219 	/*
1220 	 * Wait for idle.
1221 	 */
1222 	apic_wait_icr_idle();
1223 
1224 	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1225 	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1226 			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1227 }
1228 
1229 enum apic_intr_mode_id apic_intr_mode;
1230 
1231 static int __init apic_intr_mode_select(void)
1232 {
1233 	/* Check kernel option */
1234 	if (disable_apic) {
1235 		pr_info("APIC disabled via kernel command line\n");
1236 		return APIC_PIC;
1237 	}
1238 
1239 	/* Check BIOS */
1240 #ifdef CONFIG_X86_64
1241 	/* On 64-bit, the APIC must be integrated, Check local APIC only */
1242 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1243 		disable_apic = 1;
1244 		pr_info("APIC disabled by BIOS\n");
1245 		return APIC_PIC;
1246 	}
1247 #else
1248 	/* On 32-bit, the APIC may be integrated APIC or 82489DX */
1249 
1250 	/* Neither 82489DX nor integrated APIC ? */
1251 	if (!boot_cpu_has(X86_FEATURE_APIC) && !smp_found_config) {
1252 		disable_apic = 1;
1253 		return APIC_PIC;
1254 	}
1255 
1256 	/* If the BIOS pretends there is an integrated APIC ? */
1257 	if (!boot_cpu_has(X86_FEATURE_APIC) &&
1258 		APIC_INTEGRATED(boot_cpu_apic_version)) {
1259 		disable_apic = 1;
1260 		pr_err(FW_BUG "Local APIC %d not detected, force emulation\n",
1261 				       boot_cpu_physical_apicid);
1262 		return APIC_PIC;
1263 	}
1264 #endif
1265 
1266 	/* Check MP table or ACPI MADT configuration */
1267 	if (!smp_found_config) {
1268 		disable_ioapic_support();
1269 		if (!acpi_lapic) {
1270 			pr_info("APIC: ACPI MADT or MP tables are not detected\n");
1271 			return APIC_VIRTUAL_WIRE_NO_CONFIG;
1272 		}
1273 		return APIC_VIRTUAL_WIRE;
1274 	}
1275 
1276 #ifdef CONFIG_SMP
1277 	/* If SMP should be disabled, then really disable it! */
1278 	if (!setup_max_cpus) {
1279 		pr_info("APIC: SMP mode deactivated\n");
1280 		return APIC_SYMMETRIC_IO_NO_ROUTING;
1281 	}
1282 
1283 	if (read_apic_id() != boot_cpu_physical_apicid) {
1284 		panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
1285 		     read_apic_id(), boot_cpu_physical_apicid);
1286 		/* Or can we switch back to PIC here? */
1287 	}
1288 #endif
1289 
1290 	return APIC_SYMMETRIC_IO;
1291 }
1292 
1293 /*
1294  * An initial setup of the virtual wire mode.
1295  */
1296 void __init init_bsp_APIC(void)
1297 {
1298 	unsigned int value;
1299 
1300 	/*
1301 	 * Don't do the setup now if we have a SMP BIOS as the
1302 	 * through-I/O-APIC virtual wire mode might be active.
1303 	 */
1304 	if (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC))
1305 		return;
1306 
1307 	/*
1308 	 * Do not trust the local APIC being empty at bootup.
1309 	 */
1310 	clear_local_APIC();
1311 
1312 	/*
1313 	 * Enable APIC.
1314 	 */
1315 	value = apic_read(APIC_SPIV);
1316 	value &= ~APIC_VECTOR_MASK;
1317 	value |= APIC_SPIV_APIC_ENABLED;
1318 
1319 #ifdef CONFIG_X86_32
1320 	/* This bit is reserved on P4/Xeon and should be cleared */
1321 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1322 	    (boot_cpu_data.x86 == 15))
1323 		value &= ~APIC_SPIV_FOCUS_DISABLED;
1324 	else
1325 #endif
1326 		value |= APIC_SPIV_FOCUS_DISABLED;
1327 	value |= SPURIOUS_APIC_VECTOR;
1328 	apic_write(APIC_SPIV, value);
1329 
1330 	/*
1331 	 * Set up the virtual wire mode.
1332 	 */
1333 	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1334 	value = APIC_DM_NMI;
1335 	if (!lapic_is_integrated())		/* 82489DX */
1336 		value |= APIC_LVT_LEVEL_TRIGGER;
1337 	if (apic_extnmi == APIC_EXTNMI_NONE)
1338 		value |= APIC_LVT_MASKED;
1339 	apic_write(APIC_LVT1, value);
1340 }
1341 
1342 /* Init the interrupt delivery mode for the BSP */
1343 void __init apic_intr_mode_init(void)
1344 {
1345 	bool upmode = IS_ENABLED(CONFIG_UP_LATE_INIT);
1346 
1347 	apic_intr_mode = apic_intr_mode_select();
1348 
1349 	switch (apic_intr_mode) {
1350 	case APIC_PIC:
1351 		pr_info("APIC: Keep in PIC mode(8259)\n");
1352 		return;
1353 	case APIC_VIRTUAL_WIRE:
1354 		pr_info("APIC: Switch to virtual wire mode setup\n");
1355 		default_setup_apic_routing();
1356 		break;
1357 	case APIC_VIRTUAL_WIRE_NO_CONFIG:
1358 		pr_info("APIC: Switch to virtual wire mode setup with no configuration\n");
1359 		upmode = true;
1360 		default_setup_apic_routing();
1361 		break;
1362 	case APIC_SYMMETRIC_IO:
1363 		pr_info("APIC: Switch to symmetric I/O mode setup\n");
1364 		default_setup_apic_routing();
1365 		break;
1366 	case APIC_SYMMETRIC_IO_NO_ROUTING:
1367 		pr_info("APIC: Switch to symmetric I/O mode setup in no SMP routine\n");
1368 		break;
1369 	}
1370 
1371 	apic_bsp_setup(upmode);
1372 }
1373 
1374 static void lapic_setup_esr(void)
1375 {
1376 	unsigned int oldvalue, value, maxlvt;
1377 
1378 	if (!lapic_is_integrated()) {
1379 		pr_info("No ESR for 82489DX.\n");
1380 		return;
1381 	}
1382 
1383 	if (apic->disable_esr) {
1384 		/*
1385 		 * Something untraceable is creating bad interrupts on
1386 		 * secondary quads ... for the moment, just leave the
1387 		 * ESR disabled - we can't do anything useful with the
1388 		 * errors anyway - mbligh
1389 		 */
1390 		pr_info("Leaving ESR disabled.\n");
1391 		return;
1392 	}
1393 
1394 	maxlvt = lapic_get_maxlvt();
1395 	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1396 		apic_write(APIC_ESR, 0);
1397 	oldvalue = apic_read(APIC_ESR);
1398 
1399 	/* enables sending errors */
1400 	value = ERROR_APIC_VECTOR;
1401 	apic_write(APIC_LVTERR, value);
1402 
1403 	/*
1404 	 * spec says clear errors after enabling vector.
1405 	 */
1406 	if (maxlvt > 3)
1407 		apic_write(APIC_ESR, 0);
1408 	value = apic_read(APIC_ESR);
1409 	if (value != oldvalue)
1410 		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1411 			"vector: 0x%08x  after: 0x%08x\n",
1412 			oldvalue, value);
1413 }
1414 
1415 static void apic_pending_intr_clear(void)
1416 {
1417 	long long max_loops = cpu_khz ? cpu_khz : 1000000;
1418 	unsigned long long tsc = 0, ntsc;
1419 	unsigned int queued;
1420 	unsigned long value;
1421 	int i, j, acked = 0;
1422 
1423 	if (boot_cpu_has(X86_FEATURE_TSC))
1424 		tsc = rdtsc();
1425 	/*
1426 	 * After a crash, we no longer service the interrupts and a pending
1427 	 * interrupt from previous kernel might still have ISR bit set.
1428 	 *
1429 	 * Most probably by now CPU has serviced that pending interrupt and
1430 	 * it might not have done the ack_APIC_irq() because it thought,
1431 	 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1432 	 * does not clear the ISR bit and cpu thinks it has already serivced
1433 	 * the interrupt. Hence a vector might get locked. It was noticed
1434 	 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1435 	 */
1436 	do {
1437 		queued = 0;
1438 		for (i = APIC_ISR_NR - 1; i >= 0; i--)
1439 			queued |= apic_read(APIC_IRR + i*0x10);
1440 
1441 		for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1442 			value = apic_read(APIC_ISR + i*0x10);
1443 			for_each_set_bit(j, &value, 32) {
1444 				ack_APIC_irq();
1445 				acked++;
1446 			}
1447 		}
1448 		if (acked > 256) {
1449 			pr_err("LAPIC pending interrupts after %d EOI\n", acked);
1450 			break;
1451 		}
1452 		if (queued) {
1453 			if (boot_cpu_has(X86_FEATURE_TSC) && cpu_khz) {
1454 				ntsc = rdtsc();
1455 				max_loops = (cpu_khz << 10) - (ntsc - tsc);
1456 			} else {
1457 				max_loops--;
1458 			}
1459 		}
1460 	} while (queued && max_loops > 0);
1461 	WARN_ON(max_loops <= 0);
1462 }
1463 
1464 /**
1465  * setup_local_APIC - setup the local APIC
1466  *
1467  * Used to setup local APIC while initializing BSP or bringing up APs.
1468  * Always called with preemption disabled.
1469  */
1470 static void setup_local_APIC(void)
1471 {
1472 	int cpu = smp_processor_id();
1473 	unsigned int value;
1474 #ifdef CONFIG_X86_32
1475 	int logical_apicid, ldr_apicid;
1476 #endif
1477 
1478 
1479 	if (disable_apic) {
1480 		disable_ioapic_support();
1481 		return;
1482 	}
1483 
1484 #ifdef CONFIG_X86_32
1485 	/* Pound the ESR really hard over the head with a big hammer - mbligh */
1486 	if (lapic_is_integrated() && apic->disable_esr) {
1487 		apic_write(APIC_ESR, 0);
1488 		apic_write(APIC_ESR, 0);
1489 		apic_write(APIC_ESR, 0);
1490 		apic_write(APIC_ESR, 0);
1491 	}
1492 #endif
1493 	perf_events_lapic_init();
1494 
1495 	/*
1496 	 * Double-check whether this APIC is really registered.
1497 	 * This is meaningless in clustered apic mode, so we skip it.
1498 	 */
1499 	BUG_ON(!apic->apic_id_registered());
1500 
1501 	/*
1502 	 * Intel recommends to set DFR, LDR and TPR before enabling
1503 	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
1504 	 * document number 292116).  So here it goes...
1505 	 */
1506 	apic->init_apic_ldr();
1507 
1508 #ifdef CONFIG_X86_32
1509 	/*
1510 	 * APIC LDR is initialized.  If logical_apicid mapping was
1511 	 * initialized during get_smp_config(), make sure it matches the
1512 	 * actual value.
1513 	 */
1514 	logical_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
1515 	ldr_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
1516 	WARN_ON(logical_apicid != BAD_APICID && logical_apicid != ldr_apicid);
1517 	/* always use the value from LDR */
1518 	early_per_cpu(x86_cpu_to_logical_apicid, cpu) = ldr_apicid;
1519 #endif
1520 
1521 	/*
1522 	 * Set Task Priority to 'accept all'. We never change this
1523 	 * later on.
1524 	 */
1525 	value = apic_read(APIC_TASKPRI);
1526 	value &= ~APIC_TPRI_MASK;
1527 	apic_write(APIC_TASKPRI, value);
1528 
1529 	apic_pending_intr_clear();
1530 
1531 	/*
1532 	 * Now that we are all set up, enable the APIC
1533 	 */
1534 	value = apic_read(APIC_SPIV);
1535 	value &= ~APIC_VECTOR_MASK;
1536 	/*
1537 	 * Enable APIC
1538 	 */
1539 	value |= APIC_SPIV_APIC_ENABLED;
1540 
1541 #ifdef CONFIG_X86_32
1542 	/*
1543 	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1544 	 * certain networking cards. If high frequency interrupts are
1545 	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1546 	 * entry is masked/unmasked at a high rate as well then sooner or
1547 	 * later IOAPIC line gets 'stuck', no more interrupts are received
1548 	 * from the device. If focus CPU is disabled then the hang goes
1549 	 * away, oh well :-(
1550 	 *
1551 	 * [ This bug can be reproduced easily with a level-triggered
1552 	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1553 	 *   BX chipset. ]
1554 	 */
1555 	/*
1556 	 * Actually disabling the focus CPU check just makes the hang less
1557 	 * frequent as it makes the interrupt distributon model be more
1558 	 * like LRU than MRU (the short-term load is more even across CPUs).
1559 	 */
1560 
1561 	/*
1562 	 * - enable focus processor (bit==0)
1563 	 * - 64bit mode always use processor focus
1564 	 *   so no need to set it
1565 	 */
1566 	value &= ~APIC_SPIV_FOCUS_DISABLED;
1567 #endif
1568 
1569 	/*
1570 	 * Set spurious IRQ vector
1571 	 */
1572 	value |= SPURIOUS_APIC_VECTOR;
1573 	apic_write(APIC_SPIV, value);
1574 
1575 	/*
1576 	 * Set up LVT0, LVT1:
1577 	 *
1578 	 * set up through-local-APIC on the boot CPU's LINT0. This is not
1579 	 * strictly necessary in pure symmetric-IO mode, but sometimes
1580 	 * we delegate interrupts to the 8259A.
1581 	 */
1582 	/*
1583 	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1584 	 */
1585 	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1586 	if (!cpu && (pic_mode || !value || skip_ioapic_setup)) {
1587 		value = APIC_DM_EXTINT;
1588 		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
1589 	} else {
1590 		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1591 		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
1592 	}
1593 	apic_write(APIC_LVT0, value);
1594 
1595 	/*
1596 	 * Only the BSP sees the LINT1 NMI signal by default. This can be
1597 	 * modified by apic_extnmi= boot option.
1598 	 */
1599 	if ((!cpu && apic_extnmi != APIC_EXTNMI_NONE) ||
1600 	    apic_extnmi == APIC_EXTNMI_ALL)
1601 		value = APIC_DM_NMI;
1602 	else
1603 		value = APIC_DM_NMI | APIC_LVT_MASKED;
1604 
1605 	/* Is 82489DX ? */
1606 	if (!lapic_is_integrated())
1607 		value |= APIC_LVT_LEVEL_TRIGGER;
1608 	apic_write(APIC_LVT1, value);
1609 
1610 #ifdef CONFIG_X86_MCE_INTEL
1611 	/* Recheck CMCI information after local APIC is up on CPU #0 */
1612 	if (!cpu)
1613 		cmci_recheck();
1614 #endif
1615 }
1616 
1617 static void end_local_APIC_setup(void)
1618 {
1619 	lapic_setup_esr();
1620 
1621 #ifdef CONFIG_X86_32
1622 	{
1623 		unsigned int value;
1624 		/* Disable the local apic timer */
1625 		value = apic_read(APIC_LVTT);
1626 		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1627 		apic_write(APIC_LVTT, value);
1628 	}
1629 #endif
1630 
1631 	apic_pm_activate();
1632 }
1633 
1634 /*
1635  * APIC setup function for application processors. Called from smpboot.c
1636  */
1637 void apic_ap_setup(void)
1638 {
1639 	setup_local_APIC();
1640 	end_local_APIC_setup();
1641 }
1642 
1643 #ifdef CONFIG_X86_X2APIC
1644 int x2apic_mode;
1645 
1646 enum {
1647 	X2APIC_OFF,
1648 	X2APIC_ON,
1649 	X2APIC_DISABLED,
1650 };
1651 static int x2apic_state;
1652 
1653 static void __x2apic_disable(void)
1654 {
1655 	u64 msr;
1656 
1657 	if (!boot_cpu_has(X86_FEATURE_APIC))
1658 		return;
1659 
1660 	rdmsrl(MSR_IA32_APICBASE, msr);
1661 	if (!(msr & X2APIC_ENABLE))
1662 		return;
1663 	/* Disable xapic and x2apic first and then reenable xapic mode */
1664 	wrmsrl(MSR_IA32_APICBASE, msr & ~(X2APIC_ENABLE | XAPIC_ENABLE));
1665 	wrmsrl(MSR_IA32_APICBASE, msr & ~X2APIC_ENABLE);
1666 	printk_once(KERN_INFO "x2apic disabled\n");
1667 }
1668 
1669 static void __x2apic_enable(void)
1670 {
1671 	u64 msr;
1672 
1673 	rdmsrl(MSR_IA32_APICBASE, msr);
1674 	if (msr & X2APIC_ENABLE)
1675 		return;
1676 	wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE);
1677 	printk_once(KERN_INFO "x2apic enabled\n");
1678 }
1679 
1680 static int __init setup_nox2apic(char *str)
1681 {
1682 	if (x2apic_enabled()) {
1683 		int apicid = native_apic_msr_read(APIC_ID);
1684 
1685 		if (apicid >= 255) {
1686 			pr_warning("Apicid: %08x, cannot enforce nox2apic\n",
1687 				   apicid);
1688 			return 0;
1689 		}
1690 		pr_warning("x2apic already enabled.\n");
1691 		__x2apic_disable();
1692 	}
1693 	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
1694 	x2apic_state = X2APIC_DISABLED;
1695 	x2apic_mode = 0;
1696 	return 0;
1697 }
1698 early_param("nox2apic", setup_nox2apic);
1699 
1700 /* Called from cpu_init() to enable x2apic on (secondary) cpus */
1701 void x2apic_setup(void)
1702 {
1703 	/*
1704 	 * If x2apic is not in ON state, disable it if already enabled
1705 	 * from BIOS.
1706 	 */
1707 	if (x2apic_state != X2APIC_ON) {
1708 		__x2apic_disable();
1709 		return;
1710 	}
1711 	__x2apic_enable();
1712 }
1713 
1714 static __init void x2apic_disable(void)
1715 {
1716 	u32 x2apic_id, state = x2apic_state;
1717 
1718 	x2apic_mode = 0;
1719 	x2apic_state = X2APIC_DISABLED;
1720 
1721 	if (state != X2APIC_ON)
1722 		return;
1723 
1724 	x2apic_id = read_apic_id();
1725 	if (x2apic_id >= 255)
1726 		panic("Cannot disable x2apic, id: %08x\n", x2apic_id);
1727 
1728 	__x2apic_disable();
1729 	register_lapic_address(mp_lapic_addr);
1730 }
1731 
1732 static __init void x2apic_enable(void)
1733 {
1734 	if (x2apic_state != X2APIC_OFF)
1735 		return;
1736 
1737 	x2apic_mode = 1;
1738 	x2apic_state = X2APIC_ON;
1739 	__x2apic_enable();
1740 }
1741 
1742 static __init void try_to_enable_x2apic(int remap_mode)
1743 {
1744 	if (x2apic_state == X2APIC_DISABLED)
1745 		return;
1746 
1747 	if (remap_mode != IRQ_REMAP_X2APIC_MODE) {
1748 		/* IR is required if there is APIC ID > 255 even when running
1749 		 * under KVM
1750 		 */
1751 		if (max_physical_apicid > 255 ||
1752 		    !x86_init.hyper.x2apic_available()) {
1753 			pr_info("x2apic: IRQ remapping doesn't support X2APIC mode\n");
1754 			x2apic_disable();
1755 			return;
1756 		}
1757 
1758 		/*
1759 		 * without IR all CPUs can be addressed by IOAPIC/MSI
1760 		 * only in physical mode
1761 		 */
1762 		x2apic_phys = 1;
1763 	}
1764 	x2apic_enable();
1765 }
1766 
1767 void __init check_x2apic(void)
1768 {
1769 	if (x2apic_enabled()) {
1770 		pr_info("x2apic: enabled by BIOS, switching to x2apic ops\n");
1771 		x2apic_mode = 1;
1772 		x2apic_state = X2APIC_ON;
1773 	} else if (!boot_cpu_has(X86_FEATURE_X2APIC)) {
1774 		x2apic_state = X2APIC_DISABLED;
1775 	}
1776 }
1777 #else /* CONFIG_X86_X2APIC */
1778 static int __init validate_x2apic(void)
1779 {
1780 	if (!apic_is_x2apic_enabled())
1781 		return 0;
1782 	/*
1783 	 * Checkme: Can we simply turn off x2apic here instead of panic?
1784 	 */
1785 	panic("BIOS has enabled x2apic but kernel doesn't support x2apic, please disable x2apic in BIOS.\n");
1786 }
1787 early_initcall(validate_x2apic);
1788 
1789 static inline void try_to_enable_x2apic(int remap_mode) { }
1790 static inline void __x2apic_enable(void) { }
1791 #endif /* !CONFIG_X86_X2APIC */
1792 
1793 void __init enable_IR_x2apic(void)
1794 {
1795 	unsigned long flags;
1796 	int ret, ir_stat;
1797 
1798 	if (skip_ioapic_setup) {
1799 		pr_info("Not enabling interrupt remapping due to skipped IO-APIC setup\n");
1800 		return;
1801 	}
1802 
1803 	ir_stat = irq_remapping_prepare();
1804 	if (ir_stat < 0 && !x2apic_supported())
1805 		return;
1806 
1807 	ret = save_ioapic_entries();
1808 	if (ret) {
1809 		pr_info("Saving IO-APIC state failed: %d\n", ret);
1810 		return;
1811 	}
1812 
1813 	local_irq_save(flags);
1814 	legacy_pic->mask_all();
1815 	mask_ioapic_entries();
1816 
1817 	/* If irq_remapping_prepare() succeeded, try to enable it */
1818 	if (ir_stat >= 0)
1819 		ir_stat = irq_remapping_enable();
1820 	/* ir_stat contains the remap mode or an error code */
1821 	try_to_enable_x2apic(ir_stat);
1822 
1823 	if (ir_stat < 0)
1824 		restore_ioapic_entries();
1825 	legacy_pic->restore_mask();
1826 	local_irq_restore(flags);
1827 }
1828 
1829 #ifdef CONFIG_X86_64
1830 /*
1831  * Detect and enable local APICs on non-SMP boards.
1832  * Original code written by Keir Fraser.
1833  * On AMD64 we trust the BIOS - if it says no APIC it is likely
1834  * not correctly set up (usually the APIC timer won't work etc.)
1835  */
1836 static int __init detect_init_APIC(void)
1837 {
1838 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1839 		pr_info("No local APIC present\n");
1840 		return -1;
1841 	}
1842 
1843 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1844 	return 0;
1845 }
1846 #else
1847 
1848 static int __init apic_verify(void)
1849 {
1850 	u32 features, h, l;
1851 
1852 	/*
1853 	 * The APIC feature bit should now be enabled
1854 	 * in `cpuid'
1855 	 */
1856 	features = cpuid_edx(1);
1857 	if (!(features & (1 << X86_FEATURE_APIC))) {
1858 		pr_warning("Could not enable APIC!\n");
1859 		return -1;
1860 	}
1861 	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1862 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1863 
1864 	/* The BIOS may have set up the APIC at some other address */
1865 	if (boot_cpu_data.x86 >= 6) {
1866 		rdmsr(MSR_IA32_APICBASE, l, h);
1867 		if (l & MSR_IA32_APICBASE_ENABLE)
1868 			mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1869 	}
1870 
1871 	pr_info("Found and enabled local APIC!\n");
1872 	return 0;
1873 }
1874 
1875 int __init apic_force_enable(unsigned long addr)
1876 {
1877 	u32 h, l;
1878 
1879 	if (disable_apic)
1880 		return -1;
1881 
1882 	/*
1883 	 * Some BIOSes disable the local APIC in the APIC_BASE
1884 	 * MSR. This can only be done in software for Intel P6 or later
1885 	 * and AMD K7 (Model > 1) or later.
1886 	 */
1887 	if (boot_cpu_data.x86 >= 6) {
1888 		rdmsr(MSR_IA32_APICBASE, l, h);
1889 		if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1890 			pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1891 			l &= ~MSR_IA32_APICBASE_BASE;
1892 			l |= MSR_IA32_APICBASE_ENABLE | addr;
1893 			wrmsr(MSR_IA32_APICBASE, l, h);
1894 			enabled_via_apicbase = 1;
1895 		}
1896 	}
1897 	return apic_verify();
1898 }
1899 
1900 /*
1901  * Detect and initialize APIC
1902  */
1903 static int __init detect_init_APIC(void)
1904 {
1905 	/* Disabled by kernel option? */
1906 	if (disable_apic)
1907 		return -1;
1908 
1909 	switch (boot_cpu_data.x86_vendor) {
1910 	case X86_VENDOR_AMD:
1911 		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1912 		    (boot_cpu_data.x86 >= 15))
1913 			break;
1914 		goto no_apic;
1915 	case X86_VENDOR_INTEL:
1916 		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1917 		    (boot_cpu_data.x86 == 5 && boot_cpu_has(X86_FEATURE_APIC)))
1918 			break;
1919 		goto no_apic;
1920 	default:
1921 		goto no_apic;
1922 	}
1923 
1924 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1925 		/*
1926 		 * Over-ride BIOS and try to enable the local APIC only if
1927 		 * "lapic" specified.
1928 		 */
1929 		if (!force_enable_local_apic) {
1930 			pr_info("Local APIC disabled by BIOS -- "
1931 				"you can enable it with \"lapic\"\n");
1932 			return -1;
1933 		}
1934 		if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
1935 			return -1;
1936 	} else {
1937 		if (apic_verify())
1938 			return -1;
1939 	}
1940 
1941 	apic_pm_activate();
1942 
1943 	return 0;
1944 
1945 no_apic:
1946 	pr_info("No local APIC present or hardware disabled\n");
1947 	return -1;
1948 }
1949 #endif
1950 
1951 /**
1952  * init_apic_mappings - initialize APIC mappings
1953  */
1954 void __init init_apic_mappings(void)
1955 {
1956 	unsigned int new_apicid;
1957 
1958 	apic_check_deadline_errata();
1959 
1960 	if (x2apic_mode) {
1961 		boot_cpu_physical_apicid = read_apic_id();
1962 		return;
1963 	}
1964 
1965 	/* If no local APIC can be found return early */
1966 	if (!smp_found_config && detect_init_APIC()) {
1967 		/* lets NOP'ify apic operations */
1968 		pr_info("APIC: disable apic facility\n");
1969 		apic_disable();
1970 	} else {
1971 		apic_phys = mp_lapic_addr;
1972 
1973 		/*
1974 		 * If the system has ACPI MADT tables or MP info, the LAPIC
1975 		 * address is already registered.
1976 		 */
1977 		if (!acpi_lapic && !smp_found_config)
1978 			register_lapic_address(apic_phys);
1979 	}
1980 
1981 	/*
1982 	 * Fetch the APIC ID of the BSP in case we have a
1983 	 * default configuration (or the MP table is broken).
1984 	 */
1985 	new_apicid = read_apic_id();
1986 	if (boot_cpu_physical_apicid != new_apicid) {
1987 		boot_cpu_physical_apicid = new_apicid;
1988 		/*
1989 		 * yeah -- we lie about apic_version
1990 		 * in case if apic was disabled via boot option
1991 		 * but it's not a problem for SMP compiled kernel
1992 		 * since apic_intr_mode_select is prepared for such
1993 		 * a case and disable smp mode
1994 		 */
1995 		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
1996 	}
1997 }
1998 
1999 void __init register_lapic_address(unsigned long address)
2000 {
2001 	mp_lapic_addr = address;
2002 
2003 	if (!x2apic_mode) {
2004 		set_fixmap_nocache(FIX_APIC_BASE, address);
2005 		apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
2006 			    APIC_BASE, address);
2007 	}
2008 	if (boot_cpu_physical_apicid == -1U) {
2009 		boot_cpu_physical_apicid  = read_apic_id();
2010 		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
2011 	}
2012 }
2013 
2014 /*
2015  * Local APIC interrupts
2016  */
2017 
2018 /*
2019  * This interrupt should _never_ happen with our APIC/SMP architecture
2020  */
2021 __visible void __irq_entry smp_spurious_interrupt(struct pt_regs *regs)
2022 {
2023 	u8 vector = ~regs->orig_ax;
2024 	u32 v;
2025 
2026 	entering_irq();
2027 	trace_spurious_apic_entry(vector);
2028 
2029 	/*
2030 	 * Check if this really is a spurious interrupt and ACK it
2031 	 * if it is a vectored one.  Just in case...
2032 	 * Spurious interrupts should not be ACKed.
2033 	 */
2034 	v = apic_read(APIC_ISR + ((vector & ~0x1f) >> 1));
2035 	if (v & (1 << (vector & 0x1f)))
2036 		ack_APIC_irq();
2037 
2038 	inc_irq_stat(irq_spurious_count);
2039 
2040 	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
2041 	pr_info("spurious APIC interrupt through vector %02x on CPU#%d, "
2042 		"should never happen.\n", vector, smp_processor_id());
2043 
2044 	trace_spurious_apic_exit(vector);
2045 	exiting_irq();
2046 }
2047 
2048 /*
2049  * This interrupt should never happen with our APIC/SMP architecture
2050  */
2051 __visible void __irq_entry smp_error_interrupt(struct pt_regs *regs)
2052 {
2053 	static const char * const error_interrupt_reason[] = {
2054 		"Send CS error",		/* APIC Error Bit 0 */
2055 		"Receive CS error",		/* APIC Error Bit 1 */
2056 		"Send accept error",		/* APIC Error Bit 2 */
2057 		"Receive accept error",		/* APIC Error Bit 3 */
2058 		"Redirectable IPI",		/* APIC Error Bit 4 */
2059 		"Send illegal vector",		/* APIC Error Bit 5 */
2060 		"Received illegal vector",	/* APIC Error Bit 6 */
2061 		"Illegal register address",	/* APIC Error Bit 7 */
2062 	};
2063 	u32 v, i = 0;
2064 
2065 	entering_irq();
2066 	trace_error_apic_entry(ERROR_APIC_VECTOR);
2067 
2068 	/* First tickle the hardware, only then report what went on. -- REW */
2069 	if (lapic_get_maxlvt() > 3)	/* Due to the Pentium erratum 3AP. */
2070 		apic_write(APIC_ESR, 0);
2071 	v = apic_read(APIC_ESR);
2072 	ack_APIC_irq();
2073 	atomic_inc(&irq_err_count);
2074 
2075 	apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x",
2076 		    smp_processor_id(), v);
2077 
2078 	v &= 0xff;
2079 	while (v) {
2080 		if (v & 0x1)
2081 			apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
2082 		i++;
2083 		v >>= 1;
2084 	}
2085 
2086 	apic_printk(APIC_DEBUG, KERN_CONT "\n");
2087 
2088 	trace_error_apic_exit(ERROR_APIC_VECTOR);
2089 	exiting_irq();
2090 }
2091 
2092 /**
2093  * connect_bsp_APIC - attach the APIC to the interrupt system
2094  */
2095 static void __init connect_bsp_APIC(void)
2096 {
2097 #ifdef CONFIG_X86_32
2098 	if (pic_mode) {
2099 		/*
2100 		 * Do not trust the local APIC being empty at bootup.
2101 		 */
2102 		clear_local_APIC();
2103 		/*
2104 		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
2105 		 * local APIC to INT and NMI lines.
2106 		 */
2107 		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
2108 				"enabling APIC mode.\n");
2109 		imcr_pic_to_apic();
2110 	}
2111 #endif
2112 }
2113 
2114 /**
2115  * disconnect_bsp_APIC - detach the APIC from the interrupt system
2116  * @virt_wire_setup:	indicates, whether virtual wire mode is selected
2117  *
2118  * Virtual wire mode is necessary to deliver legacy interrupts even when the
2119  * APIC is disabled.
2120  */
2121 void disconnect_bsp_APIC(int virt_wire_setup)
2122 {
2123 	unsigned int value;
2124 
2125 #ifdef CONFIG_X86_32
2126 	if (pic_mode) {
2127 		/*
2128 		 * Put the board back into PIC mode (has an effect only on
2129 		 * certain older boards).  Note that APIC interrupts, including
2130 		 * IPIs, won't work beyond this point!  The only exception are
2131 		 * INIT IPIs.
2132 		 */
2133 		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
2134 				"entering PIC mode.\n");
2135 		imcr_apic_to_pic();
2136 		return;
2137 	}
2138 #endif
2139 
2140 	/* Go back to Virtual Wire compatibility mode */
2141 
2142 	/* For the spurious interrupt use vector F, and enable it */
2143 	value = apic_read(APIC_SPIV);
2144 	value &= ~APIC_VECTOR_MASK;
2145 	value |= APIC_SPIV_APIC_ENABLED;
2146 	value |= 0xf;
2147 	apic_write(APIC_SPIV, value);
2148 
2149 	if (!virt_wire_setup) {
2150 		/*
2151 		 * For LVT0 make it edge triggered, active high,
2152 		 * external and enabled
2153 		 */
2154 		value = apic_read(APIC_LVT0);
2155 		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2156 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2157 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2158 		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2159 		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
2160 		apic_write(APIC_LVT0, value);
2161 	} else {
2162 		/* Disable LVT0 */
2163 		apic_write(APIC_LVT0, APIC_LVT_MASKED);
2164 	}
2165 
2166 	/*
2167 	 * For LVT1 make it edge triggered, active high,
2168 	 * nmi and enabled
2169 	 */
2170 	value = apic_read(APIC_LVT1);
2171 	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2172 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2173 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2174 	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2175 	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
2176 	apic_write(APIC_LVT1, value);
2177 }
2178 
2179 /*
2180  * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
2181  * contiguously, it equals to current allocated max logical CPU ID plus 1.
2182  * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
2183  * so the maximum of nr_logical_cpuids is nr_cpu_ids.
2184  *
2185  * NOTE: Reserve 0 for BSP.
2186  */
2187 static int nr_logical_cpuids = 1;
2188 
2189 /*
2190  * Used to store mapping between logical CPU IDs and APIC IDs.
2191  */
2192 static int cpuid_to_apicid[] = {
2193 	[0 ... NR_CPUS - 1] = -1,
2194 };
2195 
2196 #ifdef CONFIG_SMP
2197 /**
2198  * apic_id_is_primary_thread - Check whether APIC ID belongs to a primary thread
2199  * @id:	APIC ID to check
2200  */
2201 bool apic_id_is_primary_thread(unsigned int apicid)
2202 {
2203 	u32 mask;
2204 
2205 	if (smp_num_siblings == 1)
2206 		return true;
2207 	/* Isolate the SMT bit(s) in the APICID and check for 0 */
2208 	mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
2209 	return !(apicid & mask);
2210 }
2211 #endif
2212 
2213 /*
2214  * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
2215  * and cpuid_to_apicid[] synchronized.
2216  */
2217 static int allocate_logical_cpuid(int apicid)
2218 {
2219 	int i;
2220 
2221 	/*
2222 	 * cpuid <-> apicid mapping is persistent, so when a cpu is up,
2223 	 * check if the kernel has allocated a cpuid for it.
2224 	 */
2225 	for (i = 0; i < nr_logical_cpuids; i++) {
2226 		if (cpuid_to_apicid[i] == apicid)
2227 			return i;
2228 	}
2229 
2230 	/* Allocate a new cpuid. */
2231 	if (nr_logical_cpuids >= nr_cpu_ids) {
2232 		WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
2233 			     "Processor %d/0x%x and the rest are ignored.\n",
2234 			     nr_cpu_ids, nr_logical_cpuids, apicid);
2235 		return -EINVAL;
2236 	}
2237 
2238 	cpuid_to_apicid[nr_logical_cpuids] = apicid;
2239 	return nr_logical_cpuids++;
2240 }
2241 
2242 int generic_processor_info(int apicid, int version)
2243 {
2244 	int cpu, max = nr_cpu_ids;
2245 	bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
2246 				phys_cpu_present_map);
2247 
2248 	/*
2249 	 * boot_cpu_physical_apicid is designed to have the apicid
2250 	 * returned by read_apic_id(), i.e, the apicid of the
2251 	 * currently booting-up processor. However, on some platforms,
2252 	 * it is temporarily modified by the apicid reported as BSP
2253 	 * through MP table. Concretely:
2254 	 *
2255 	 * - arch/x86/kernel/mpparse.c: MP_processor_info()
2256 	 * - arch/x86/mm/amdtopology.c: amd_numa_init()
2257 	 *
2258 	 * This function is executed with the modified
2259 	 * boot_cpu_physical_apicid. So, disabled_cpu_apicid kernel
2260 	 * parameter doesn't work to disable APs on kdump 2nd kernel.
2261 	 *
2262 	 * Since fixing handling of boot_cpu_physical_apicid requires
2263 	 * another discussion and tests on each platform, we leave it
2264 	 * for now and here we use read_apic_id() directly in this
2265 	 * function, generic_processor_info().
2266 	 */
2267 	if (disabled_cpu_apicid != BAD_APICID &&
2268 	    disabled_cpu_apicid != read_apic_id() &&
2269 	    disabled_cpu_apicid == apicid) {
2270 		int thiscpu = num_processors + disabled_cpus;
2271 
2272 		pr_warning("APIC: Disabling requested cpu."
2273 			   " Processor %d/0x%x ignored.\n",
2274 			   thiscpu, apicid);
2275 
2276 		disabled_cpus++;
2277 		return -ENODEV;
2278 	}
2279 
2280 	/*
2281 	 * If boot cpu has not been detected yet, then only allow upto
2282 	 * nr_cpu_ids - 1 processors and keep one slot free for boot cpu
2283 	 */
2284 	if (!boot_cpu_detected && num_processors >= nr_cpu_ids - 1 &&
2285 	    apicid != boot_cpu_physical_apicid) {
2286 		int thiscpu = max + disabled_cpus - 1;
2287 
2288 		pr_warning(
2289 			"APIC: NR_CPUS/possible_cpus limit of %i almost"
2290 			" reached. Keeping one slot for boot cpu."
2291 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
2292 
2293 		disabled_cpus++;
2294 		return -ENODEV;
2295 	}
2296 
2297 	if (num_processors >= nr_cpu_ids) {
2298 		int thiscpu = max + disabled_cpus;
2299 
2300 		pr_warning("APIC: NR_CPUS/possible_cpus limit of %i "
2301 			   "reached. Processor %d/0x%x ignored.\n",
2302 			   max, thiscpu, apicid);
2303 
2304 		disabled_cpus++;
2305 		return -EINVAL;
2306 	}
2307 
2308 	if (apicid == boot_cpu_physical_apicid) {
2309 		/*
2310 		 * x86_bios_cpu_apicid is required to have processors listed
2311 		 * in same order as logical cpu numbers. Hence the first
2312 		 * entry is BSP, and so on.
2313 		 * boot_cpu_init() already hold bit 0 in cpu_present_mask
2314 		 * for BSP.
2315 		 */
2316 		cpu = 0;
2317 
2318 		/* Logical cpuid 0 is reserved for BSP. */
2319 		cpuid_to_apicid[0] = apicid;
2320 	} else {
2321 		cpu = allocate_logical_cpuid(apicid);
2322 		if (cpu < 0) {
2323 			disabled_cpus++;
2324 			return -EINVAL;
2325 		}
2326 	}
2327 
2328 	/*
2329 	 * Validate version
2330 	 */
2331 	if (version == 0x0) {
2332 		pr_warning("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
2333 			   cpu, apicid);
2334 		version = 0x10;
2335 	}
2336 
2337 	if (version != boot_cpu_apic_version) {
2338 		pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
2339 			boot_cpu_apic_version, cpu, version);
2340 	}
2341 
2342 	if (apicid > max_physical_apicid)
2343 		max_physical_apicid = apicid;
2344 
2345 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
2346 	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
2347 	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
2348 #endif
2349 #ifdef CONFIG_X86_32
2350 	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
2351 		apic->x86_32_early_logical_apicid(cpu);
2352 #endif
2353 	set_cpu_possible(cpu, true);
2354 	physid_set(apicid, phys_cpu_present_map);
2355 	set_cpu_present(cpu, true);
2356 	num_processors++;
2357 
2358 	return cpu;
2359 }
2360 
2361 int hard_smp_processor_id(void)
2362 {
2363 	return read_apic_id();
2364 }
2365 
2366 /*
2367  * Override the generic EOI implementation with an optimized version.
2368  * Only called during early boot when only one CPU is active and with
2369  * interrupts disabled, so we know this does not race with actual APIC driver
2370  * use.
2371  */
2372 void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v))
2373 {
2374 	struct apic **drv;
2375 
2376 	for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
2377 		/* Should happen once for each apic */
2378 		WARN_ON((*drv)->eoi_write == eoi_write);
2379 		(*drv)->native_eoi_write = (*drv)->eoi_write;
2380 		(*drv)->eoi_write = eoi_write;
2381 	}
2382 }
2383 
2384 static void __init apic_bsp_up_setup(void)
2385 {
2386 #ifdef CONFIG_X86_64
2387 	apic_write(APIC_ID, apic->set_apic_id(boot_cpu_physical_apicid));
2388 #else
2389 	/*
2390 	 * Hack: In case of kdump, after a crash, kernel might be booting
2391 	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
2392 	 * might be zero if read from MP tables. Get it from LAPIC.
2393 	 */
2394 # ifdef CONFIG_CRASH_DUMP
2395 	boot_cpu_physical_apicid = read_apic_id();
2396 # endif
2397 #endif
2398 	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
2399 }
2400 
2401 /**
2402  * apic_bsp_setup - Setup function for local apic and io-apic
2403  * @upmode:		Force UP mode (for APIC_init_uniprocessor)
2404  *
2405  * Returns:
2406  * apic_id of BSP APIC
2407  */
2408 void __init apic_bsp_setup(bool upmode)
2409 {
2410 	connect_bsp_APIC();
2411 	if (upmode)
2412 		apic_bsp_up_setup();
2413 	setup_local_APIC();
2414 
2415 	enable_IO_APIC();
2416 	end_local_APIC_setup();
2417 	irq_remap_enable_fault_handling();
2418 	setup_IO_APIC();
2419 }
2420 
2421 #ifdef CONFIG_UP_LATE_INIT
2422 void __init up_late_init(void)
2423 {
2424 	if (apic_intr_mode == APIC_PIC)
2425 		return;
2426 
2427 	/* Setup local timer */
2428 	x86_init.timers.setup_percpu_clockev();
2429 }
2430 #endif
2431 
2432 /*
2433  * Power management
2434  */
2435 #ifdef CONFIG_PM
2436 
2437 static struct {
2438 	/*
2439 	 * 'active' is true if the local APIC was enabled by us and
2440 	 * not the BIOS; this signifies that we are also responsible
2441 	 * for disabling it before entering apm/acpi suspend
2442 	 */
2443 	int active;
2444 	/* r/w apic fields */
2445 	unsigned int apic_id;
2446 	unsigned int apic_taskpri;
2447 	unsigned int apic_ldr;
2448 	unsigned int apic_dfr;
2449 	unsigned int apic_spiv;
2450 	unsigned int apic_lvtt;
2451 	unsigned int apic_lvtpc;
2452 	unsigned int apic_lvt0;
2453 	unsigned int apic_lvt1;
2454 	unsigned int apic_lvterr;
2455 	unsigned int apic_tmict;
2456 	unsigned int apic_tdcr;
2457 	unsigned int apic_thmr;
2458 	unsigned int apic_cmci;
2459 } apic_pm_state;
2460 
2461 static int lapic_suspend(void)
2462 {
2463 	unsigned long flags;
2464 	int maxlvt;
2465 
2466 	if (!apic_pm_state.active)
2467 		return 0;
2468 
2469 	maxlvt = lapic_get_maxlvt();
2470 
2471 	apic_pm_state.apic_id = apic_read(APIC_ID);
2472 	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2473 	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2474 	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2475 	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2476 	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2477 	if (maxlvt >= 4)
2478 		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2479 	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2480 	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2481 	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2482 	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2483 	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2484 #ifdef CONFIG_X86_THERMAL_VECTOR
2485 	if (maxlvt >= 5)
2486 		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2487 #endif
2488 #ifdef CONFIG_X86_MCE_INTEL
2489 	if (maxlvt >= 6)
2490 		apic_pm_state.apic_cmci = apic_read(APIC_LVTCMCI);
2491 #endif
2492 
2493 	local_irq_save(flags);
2494 	disable_local_APIC();
2495 
2496 	irq_remapping_disable();
2497 
2498 	local_irq_restore(flags);
2499 	return 0;
2500 }
2501 
2502 static void lapic_resume(void)
2503 {
2504 	unsigned int l, h;
2505 	unsigned long flags;
2506 	int maxlvt;
2507 
2508 	if (!apic_pm_state.active)
2509 		return;
2510 
2511 	local_irq_save(flags);
2512 
2513 	/*
2514 	 * IO-APIC and PIC have their own resume routines.
2515 	 * We just mask them here to make sure the interrupt
2516 	 * subsystem is completely quiet while we enable x2apic
2517 	 * and interrupt-remapping.
2518 	 */
2519 	mask_ioapic_entries();
2520 	legacy_pic->mask_all();
2521 
2522 	if (x2apic_mode) {
2523 		__x2apic_enable();
2524 	} else {
2525 		/*
2526 		 * Make sure the APICBASE points to the right address
2527 		 *
2528 		 * FIXME! This will be wrong if we ever support suspend on
2529 		 * SMP! We'll need to do this as part of the CPU restore!
2530 		 */
2531 		if (boot_cpu_data.x86 >= 6) {
2532 			rdmsr(MSR_IA32_APICBASE, l, h);
2533 			l &= ~MSR_IA32_APICBASE_BASE;
2534 			l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2535 			wrmsr(MSR_IA32_APICBASE, l, h);
2536 		}
2537 	}
2538 
2539 	maxlvt = lapic_get_maxlvt();
2540 	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2541 	apic_write(APIC_ID, apic_pm_state.apic_id);
2542 	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2543 	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2544 	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2545 	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2546 	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2547 	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2548 #ifdef CONFIG_X86_THERMAL_VECTOR
2549 	if (maxlvt >= 5)
2550 		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2551 #endif
2552 #ifdef CONFIG_X86_MCE_INTEL
2553 	if (maxlvt >= 6)
2554 		apic_write(APIC_LVTCMCI, apic_pm_state.apic_cmci);
2555 #endif
2556 	if (maxlvt >= 4)
2557 		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2558 	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2559 	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2560 	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2561 	apic_write(APIC_ESR, 0);
2562 	apic_read(APIC_ESR);
2563 	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2564 	apic_write(APIC_ESR, 0);
2565 	apic_read(APIC_ESR);
2566 
2567 	irq_remapping_reenable(x2apic_mode);
2568 
2569 	local_irq_restore(flags);
2570 }
2571 
2572 /*
2573  * This device has no shutdown method - fully functioning local APICs
2574  * are needed on every CPU up until machine_halt/restart/poweroff.
2575  */
2576 
2577 static struct syscore_ops lapic_syscore_ops = {
2578 	.resume		= lapic_resume,
2579 	.suspend	= lapic_suspend,
2580 };
2581 
2582 static void apic_pm_activate(void)
2583 {
2584 	apic_pm_state.active = 1;
2585 }
2586 
2587 static int __init init_lapic_sysfs(void)
2588 {
2589 	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2590 	if (boot_cpu_has(X86_FEATURE_APIC))
2591 		register_syscore_ops(&lapic_syscore_ops);
2592 
2593 	return 0;
2594 }
2595 
2596 /* local apic needs to resume before other devices access its registers. */
2597 core_initcall(init_lapic_sysfs);
2598 
2599 #else	/* CONFIG_PM */
2600 
2601 static void apic_pm_activate(void) { }
2602 
2603 #endif	/* CONFIG_PM */
2604 
2605 #ifdef CONFIG_X86_64
2606 
2607 static int multi_checked;
2608 static int multi;
2609 
2610 static int set_multi(const struct dmi_system_id *d)
2611 {
2612 	if (multi)
2613 		return 0;
2614 	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2615 	multi = 1;
2616 	return 0;
2617 }
2618 
2619 static const struct dmi_system_id multi_dmi_table[] = {
2620 	{
2621 		.callback = set_multi,
2622 		.ident = "IBM System Summit2",
2623 		.matches = {
2624 			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2625 			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2626 		},
2627 	},
2628 	{}
2629 };
2630 
2631 static void dmi_check_multi(void)
2632 {
2633 	if (multi_checked)
2634 		return;
2635 
2636 	dmi_check_system(multi_dmi_table);
2637 	multi_checked = 1;
2638 }
2639 
2640 /*
2641  * apic_is_clustered_box() -- Check if we can expect good TSC
2642  *
2643  * Thus far, the major user of this is IBM's Summit2 series:
2644  * Clustered boxes may have unsynced TSC problems if they are
2645  * multi-chassis.
2646  * Use DMI to check them
2647  */
2648 int apic_is_clustered_box(void)
2649 {
2650 	dmi_check_multi();
2651 	return multi;
2652 }
2653 #endif
2654 
2655 /*
2656  * APIC command line parameters
2657  */
2658 static int __init setup_disableapic(char *arg)
2659 {
2660 	disable_apic = 1;
2661 	setup_clear_cpu_cap(X86_FEATURE_APIC);
2662 	return 0;
2663 }
2664 early_param("disableapic", setup_disableapic);
2665 
2666 /* same as disableapic, for compatibility */
2667 static int __init setup_nolapic(char *arg)
2668 {
2669 	return setup_disableapic(arg);
2670 }
2671 early_param("nolapic", setup_nolapic);
2672 
2673 static int __init parse_lapic_timer_c2_ok(char *arg)
2674 {
2675 	local_apic_timer_c2_ok = 1;
2676 	return 0;
2677 }
2678 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2679 
2680 static int __init parse_disable_apic_timer(char *arg)
2681 {
2682 	disable_apic_timer = 1;
2683 	return 0;
2684 }
2685 early_param("noapictimer", parse_disable_apic_timer);
2686 
2687 static int __init parse_nolapic_timer(char *arg)
2688 {
2689 	disable_apic_timer = 1;
2690 	return 0;
2691 }
2692 early_param("nolapic_timer", parse_nolapic_timer);
2693 
2694 static int __init apic_set_verbosity(char *arg)
2695 {
2696 	if (!arg)  {
2697 #ifdef CONFIG_X86_64
2698 		skip_ioapic_setup = 0;
2699 		return 0;
2700 #endif
2701 		return -EINVAL;
2702 	}
2703 
2704 	if (strcmp("debug", arg) == 0)
2705 		apic_verbosity = APIC_DEBUG;
2706 	else if (strcmp("verbose", arg) == 0)
2707 		apic_verbosity = APIC_VERBOSE;
2708 #ifdef CONFIG_X86_64
2709 	else {
2710 		pr_warning("APIC Verbosity level %s not recognised"
2711 			" use apic=verbose or apic=debug\n", arg);
2712 		return -EINVAL;
2713 	}
2714 #endif
2715 
2716 	return 0;
2717 }
2718 early_param("apic", apic_set_verbosity);
2719 
2720 static int __init lapic_insert_resource(void)
2721 {
2722 	if (!apic_phys)
2723 		return -1;
2724 
2725 	/* Put local APIC into the resource map. */
2726 	lapic_resource.start = apic_phys;
2727 	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2728 	insert_resource(&iomem_resource, &lapic_resource);
2729 
2730 	return 0;
2731 }
2732 
2733 /*
2734  * need call insert after e820__reserve_resources()
2735  * that is using request_resource
2736  */
2737 late_initcall(lapic_insert_resource);
2738 
2739 static int __init apic_set_disabled_cpu_apicid(char *arg)
2740 {
2741 	if (!arg || !get_option(&arg, &disabled_cpu_apicid))
2742 		return -EINVAL;
2743 
2744 	return 0;
2745 }
2746 early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);
2747 
2748 static int __init apic_set_extnmi(char *arg)
2749 {
2750 	if (!arg)
2751 		return -EINVAL;
2752 
2753 	if (!strncmp("all", arg, 3))
2754 		apic_extnmi = APIC_EXTNMI_ALL;
2755 	else if (!strncmp("none", arg, 4))
2756 		apic_extnmi = APIC_EXTNMI_NONE;
2757 	else if (!strncmp("bsp", arg, 3))
2758 		apic_extnmi = APIC_EXTNMI_BSP;
2759 	else {
2760 		pr_warn("Unknown external NMI delivery mode `%s' ignored\n", arg);
2761 		return -EINVAL;
2762 	}
2763 
2764 	return 0;
2765 }
2766 early_param("apic_extnmi", apic_set_extnmi);
2767