apic.c revision 25970852280c9d5fb2de899769880d3e97332baa
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/module.h>
27#include <linux/syscore_ops.h>
28#include <linux/delay.h>
29#include <linux/timex.h>
30#include <linux/dmar.h>
31#include <linux/init.h>
32#include <linux/cpu.h>
33#include <linux/dmi.h>
34#include <linux/smp.h>
35#include <linux/mm.h>
36
37#include <asm/perf_event.h>
38#include <asm/x86_init.h>
39#include <asm/pgalloc.h>
40#include <asm/atomic.h>
41#include <asm/mpspec.h>
42#include <asm/i8253.h>
43#include <asm/i8259.h>
44#include <asm/proto.h>
45#include <asm/apic.h>
46#include <asm/io_apic.h>
47#include <asm/desc.h>
48#include <asm/hpet.h>
49#include <asm/idle.h>
50#include <asm/mtrr.h>
51#include <asm/smp.h>
52#include <asm/mce.h>
53#include <asm/tsc.h>
54#include <asm/hypervisor.h>
55
56unsigned int num_processors;
57
58unsigned disabled_cpus __cpuinitdata;
59
60/* Processor that is doing the boot up */
61unsigned int boot_cpu_physical_apicid = -1U;
62
63/*
64 * The highest APIC ID seen during enumeration.
65 */
66unsigned int max_physical_apicid;
67
68/*
69 * Bitmask of physically existing CPUs:
70 */
71physid_mask_t phys_cpu_present_map;
72
73/*
74 * Map cpu index to physical APIC ID
75 */
76DEFINE_EARLY_PER_CPU(u16, x86_cpu_to_apicid, BAD_APICID);
77DEFINE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid, BAD_APICID);
78EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
79EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
80
81#ifdef CONFIG_X86_32
82
83/*
84 * On x86_32, the mapping between cpu and logical apicid may vary
85 * depending on apic in use.  The following early percpu variable is
86 * used for the mapping.  This is where the behaviors of x86_64 and 32
87 * actually diverge.  Let's keep it ugly for now.
88 */
89DEFINE_EARLY_PER_CPU(int, x86_cpu_to_logical_apicid, BAD_APICID);
90
91/*
92 * Knob to control our willingness to enable the local APIC.
93 *
94 * +1=force-enable
95 */
96static int force_enable_local_apic __initdata;
97/*
98 * APIC command line parameters
99 */
100static int __init parse_lapic(char *arg)
101{
102	force_enable_local_apic = 1;
103	return 0;
104}
105early_param("lapic", parse_lapic);
106/* Local APIC was disabled by the BIOS and enabled by the kernel */
107static int enabled_via_apicbase;
108
109/*
110 * Handle interrupt mode configuration register (IMCR).
111 * This register controls whether the interrupt signals
112 * that reach the BSP come from the master PIC or from the
113 * local APIC. Before entering Symmetric I/O Mode, either
114 * the BIOS or the operating system must switch out of
115 * PIC Mode by changing the IMCR.
116 */
117static inline void imcr_pic_to_apic(void)
118{
119	/* select IMCR register */
120	outb(0x70, 0x22);
121	/* NMI and 8259 INTR go through APIC */
122	outb(0x01, 0x23);
123}
124
125static inline void imcr_apic_to_pic(void)
126{
127	/* select IMCR register */
128	outb(0x70, 0x22);
129	/* NMI and 8259 INTR go directly to BSP */
130	outb(0x00, 0x23);
131}
132#endif
133
134#ifdef CONFIG_X86_64
135static int apic_calibrate_pmtmr __initdata;
136static __init int setup_apicpmtimer(char *s)
137{
138	apic_calibrate_pmtmr = 1;
139	notsc_setup(NULL);
140	return 0;
141}
142__setup("apicpmtimer", setup_apicpmtimer);
143#endif
144
145int x2apic_mode;
146#ifdef CONFIG_X86_X2APIC
147/* x2apic enabled before OS handover */
148static int x2apic_preenabled;
149static __init int setup_nox2apic(char *str)
150{
151	if (x2apic_enabled()) {
152		pr_warning("Bios already enabled x2apic, "
153			   "can't enforce nox2apic");
154		return 0;
155	}
156
157	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
158	return 0;
159}
160early_param("nox2apic", setup_nox2apic);
161#endif
162
163unsigned long mp_lapic_addr;
164int disable_apic;
165/* Disable local APIC timer from the kernel commandline or via dmi quirk */
166static int disable_apic_timer __initdata;
167/* Local APIC timer works in C2 */
168int local_apic_timer_c2_ok;
169EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
170
171int first_system_vector = 0xfe;
172
173/*
174 * Debug level, exported for io_apic.c
175 */
176unsigned int apic_verbosity;
177
178int pic_mode;
179
180/* Have we found an MP table */
181int smp_found_config;
182
183static struct resource lapic_resource = {
184	.name = "Local APIC",
185	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
186};
187
188static unsigned int calibration_result;
189
190static void apic_pm_activate(void);
191
192static unsigned long apic_phys;
193
194/*
195 * Get the LAPIC version
196 */
197static inline int lapic_get_version(void)
198{
199	return GET_APIC_VERSION(apic_read(APIC_LVR));
200}
201
202/*
203 * Check, if the APIC is integrated or a separate chip
204 */
205static inline int lapic_is_integrated(void)
206{
207#ifdef CONFIG_X86_64
208	return 1;
209#else
210	return APIC_INTEGRATED(lapic_get_version());
211#endif
212}
213
214/*
215 * Check, whether this is a modern or a first generation APIC
216 */
217static int modern_apic(void)
218{
219	/* AMD systems use old APIC versions, so check the CPU */
220	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
221	    boot_cpu_data.x86 >= 0xf)
222		return 1;
223	return lapic_get_version() >= 0x14;
224}
225
226/*
227 * right after this call apic become NOOP driven
228 * so apic->write/read doesn't do anything
229 */
230static void __init apic_disable(void)
231{
232	pr_info("APIC: switched to apic NOOP\n");
233	apic = &apic_noop;
234}
235
236void native_apic_wait_icr_idle(void)
237{
238	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
239		cpu_relax();
240}
241
242u32 native_safe_apic_wait_icr_idle(void)
243{
244	u32 send_status;
245	int timeout;
246
247	timeout = 0;
248	do {
249		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
250		if (!send_status)
251			break;
252		udelay(100);
253	} while (timeout++ < 1000);
254
255	return send_status;
256}
257
258void native_apic_icr_write(u32 low, u32 id)
259{
260	apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
261	apic_write(APIC_ICR, low);
262}
263
264u64 native_apic_icr_read(void)
265{
266	u32 icr1, icr2;
267
268	icr2 = apic_read(APIC_ICR2);
269	icr1 = apic_read(APIC_ICR);
270
271	return icr1 | ((u64)icr2 << 32);
272}
273
274#ifdef CONFIG_X86_32
275/**
276 * get_physical_broadcast - Get number of physical broadcast IDs
277 */
278int get_physical_broadcast(void)
279{
280	return modern_apic() ? 0xff : 0xf;
281}
282#endif
283
284/**
285 * lapic_get_maxlvt - get the maximum number of local vector table entries
286 */
287int lapic_get_maxlvt(void)
288{
289	unsigned int v;
290
291	v = apic_read(APIC_LVR);
292	/*
293	 * - we always have APIC integrated on 64bit mode
294	 * - 82489DXs do not report # of LVT entries
295	 */
296	return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
297}
298
299/*
300 * Local APIC timer
301 */
302
303/* Clock divisor */
304#define APIC_DIVISOR 16
305
306/*
307 * This function sets up the local APIC timer, with a timeout of
308 * 'clocks' APIC bus clock. During calibration we actually call
309 * this function twice on the boot CPU, once with a bogus timeout
310 * value, second time for real. The other (noncalibrating) CPUs
311 * call this function only once, with the real, calibrated value.
312 *
313 * We do reads before writes even if unnecessary, to get around the
314 * P5 APIC double write bug.
315 */
316static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
317{
318	unsigned int lvtt_value, tmp_value;
319
320	lvtt_value = LOCAL_TIMER_VECTOR;
321	if (!oneshot)
322		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
323	if (!lapic_is_integrated())
324		lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
325
326	if (!irqen)
327		lvtt_value |= APIC_LVT_MASKED;
328
329	apic_write(APIC_LVTT, lvtt_value);
330
331	/*
332	 * Divide PICLK by 16
333	 */
334	tmp_value = apic_read(APIC_TDCR);
335	apic_write(APIC_TDCR,
336		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
337		APIC_TDR_DIV_16);
338
339	if (!oneshot)
340		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
341}
342
343/*
344 * Setup extended LVT, AMD specific
345 *
346 * Software should use the LVT offsets the BIOS provides.  The offsets
347 * are determined by the subsystems using it like those for MCE
348 * threshold or IBS.  On K8 only offset 0 (APIC500) and MCE interrupts
349 * are supported. Beginning with family 10h at least 4 offsets are
350 * available.
351 *
352 * Since the offsets must be consistent for all cores, we keep track
353 * of the LVT offsets in software and reserve the offset for the same
354 * vector also to be used on other cores. An offset is freed by
355 * setting the entry to APIC_EILVT_MASKED.
356 *
357 * If the BIOS is right, there should be no conflicts. Otherwise a
358 * "[Firmware Bug]: ..." error message is generated. However, if
359 * software does not properly determines the offsets, it is not
360 * necessarily a BIOS bug.
361 */
362
363static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
364
365static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
366{
367	return (old & APIC_EILVT_MASKED)
368		|| (new == APIC_EILVT_MASKED)
369		|| ((new & ~APIC_EILVT_MASKED) == old);
370}
371
372static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
373{
374	unsigned int rsvd;			/* 0: uninitialized */
375
376	if (offset >= APIC_EILVT_NR_MAX)
377		return ~0;
378
379	rsvd = atomic_read(&eilvt_offsets[offset]) & ~APIC_EILVT_MASKED;
380	do {
381		if (rsvd &&
382		    !eilvt_entry_is_changeable(rsvd, new))
383			/* may not change if vectors are different */
384			return rsvd;
385		rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new);
386	} while (rsvd != new);
387
388	return new;
389}
390
391/*
392 * If mask=1, the LVT entry does not generate interrupts while mask=0
393 * enables the vector. See also the BKDGs. Must be called with
394 * preemption disabled.
395 */
396
397int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
398{
399	unsigned long reg = APIC_EILVTn(offset);
400	unsigned int new, old, reserved;
401
402	new = (mask << 16) | (msg_type << 8) | vector;
403	old = apic_read(reg);
404	reserved = reserve_eilvt_offset(offset, new);
405
406	if (reserved != new) {
407		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
408		       "vector 0x%x, but the register is already in use for "
409		       "vector 0x%x on another cpu\n",
410		       smp_processor_id(), reg, offset, new, reserved);
411		return -EINVAL;
412	}
413
414	if (!eilvt_entry_is_changeable(old, new)) {
415		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
416		       "vector 0x%x, but the register is already in use for "
417		       "vector 0x%x on this cpu\n",
418		       smp_processor_id(), reg, offset, new, old);
419		return -EBUSY;
420	}
421
422	apic_write(reg, new);
423
424	return 0;
425}
426EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
427
428/*
429 * Program the next event, relative to now
430 */
431static int lapic_next_event(unsigned long delta,
432			    struct clock_event_device *evt)
433{
434	apic_write(APIC_TMICT, delta);
435	return 0;
436}
437
438/*
439 * Setup the lapic timer in periodic or oneshot mode
440 */
441static void lapic_timer_setup(enum clock_event_mode mode,
442			      struct clock_event_device *evt)
443{
444	unsigned long flags;
445	unsigned int v;
446
447	/* Lapic used as dummy for broadcast ? */
448	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
449		return;
450
451	local_irq_save(flags);
452
453	switch (mode) {
454	case CLOCK_EVT_MODE_PERIODIC:
455	case CLOCK_EVT_MODE_ONESHOT:
456		__setup_APIC_LVTT(calibration_result,
457				  mode != CLOCK_EVT_MODE_PERIODIC, 1);
458		break;
459	case CLOCK_EVT_MODE_UNUSED:
460	case CLOCK_EVT_MODE_SHUTDOWN:
461		v = apic_read(APIC_LVTT);
462		v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
463		apic_write(APIC_LVTT, v);
464		apic_write(APIC_TMICT, 0);
465		break;
466	case CLOCK_EVT_MODE_RESUME:
467		/* Nothing to do here */
468		break;
469	}
470
471	local_irq_restore(flags);
472}
473
474/*
475 * Local APIC timer broadcast function
476 */
477static void lapic_timer_broadcast(const struct cpumask *mask)
478{
479#ifdef CONFIG_SMP
480	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
481#endif
482}
483
484
485/*
486 * The local apic timer can be used for any function which is CPU local.
487 */
488static struct clock_event_device lapic_clockevent = {
489	.name		= "lapic",
490	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
491			| CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
492	.shift		= 32,
493	.set_mode	= lapic_timer_setup,
494	.set_next_event	= lapic_next_event,
495	.broadcast	= lapic_timer_broadcast,
496	.rating		= 100,
497	.irq		= -1,
498};
499static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
500
501/*
502 * Setup the local APIC timer for this CPU. Copy the initialized values
503 * of the boot CPU and register the clock event in the framework.
504 */
505static void __cpuinit setup_APIC_timer(void)
506{
507	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
508
509	if (this_cpu_has(X86_FEATURE_ARAT)) {
510		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
511		/* Make LAPIC timer preferrable over percpu HPET */
512		lapic_clockevent.rating = 150;
513	}
514
515	memcpy(levt, &lapic_clockevent, sizeof(*levt));
516	levt->cpumask = cpumask_of(smp_processor_id());
517
518	clockevents_register_device(levt);
519}
520
521/*
522 * In this functions we calibrate APIC bus clocks to the external timer.
523 *
524 * We want to do the calibration only once since we want to have local timer
525 * irqs syncron. CPUs connected by the same APIC bus have the very same bus
526 * frequency.
527 *
528 * This was previously done by reading the PIT/HPET and waiting for a wrap
529 * around to find out, that a tick has elapsed. I have a box, where the PIT
530 * readout is broken, so it never gets out of the wait loop again. This was
531 * also reported by others.
532 *
533 * Monitoring the jiffies value is inaccurate and the clockevents
534 * infrastructure allows us to do a simple substitution of the interrupt
535 * handler.
536 *
537 * The calibration routine also uses the pm_timer when possible, as the PIT
538 * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
539 * back to normal later in the boot process).
540 */
541
542#define LAPIC_CAL_LOOPS		(HZ/10)
543
544static __initdata int lapic_cal_loops = -1;
545static __initdata long lapic_cal_t1, lapic_cal_t2;
546static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
547static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
548static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
549
550/*
551 * Temporary interrupt handler.
552 */
553static void __init lapic_cal_handler(struct clock_event_device *dev)
554{
555	unsigned long long tsc = 0;
556	long tapic = apic_read(APIC_TMCCT);
557	unsigned long pm = acpi_pm_read_early();
558
559	if (cpu_has_tsc)
560		rdtscll(tsc);
561
562	switch (lapic_cal_loops++) {
563	case 0:
564		lapic_cal_t1 = tapic;
565		lapic_cal_tsc1 = tsc;
566		lapic_cal_pm1 = pm;
567		lapic_cal_j1 = jiffies;
568		break;
569
570	case LAPIC_CAL_LOOPS:
571		lapic_cal_t2 = tapic;
572		lapic_cal_tsc2 = tsc;
573		if (pm < lapic_cal_pm1)
574			pm += ACPI_PM_OVRRUN;
575		lapic_cal_pm2 = pm;
576		lapic_cal_j2 = jiffies;
577		break;
578	}
579}
580
581static int __init
582calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
583{
584	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
585	const long pm_thresh = pm_100ms / 100;
586	unsigned long mult;
587	u64 res;
588
589#ifndef CONFIG_X86_PM_TIMER
590	return -1;
591#endif
592
593	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
594
595	/* Check, if the PM timer is available */
596	if (!deltapm)
597		return -1;
598
599	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
600
601	if (deltapm > (pm_100ms - pm_thresh) &&
602	    deltapm < (pm_100ms + pm_thresh)) {
603		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
604		return 0;
605	}
606
607	res = (((u64)deltapm) *  mult) >> 22;
608	do_div(res, 1000000);
609	pr_warning("APIC calibration not consistent "
610		   "with PM-Timer: %ldms instead of 100ms\n",(long)res);
611
612	/* Correct the lapic counter value */
613	res = (((u64)(*delta)) * pm_100ms);
614	do_div(res, deltapm);
615	pr_info("APIC delta adjusted to PM-Timer: "
616		"%lu (%ld)\n", (unsigned long)res, *delta);
617	*delta = (long)res;
618
619	/* Correct the tsc counter value */
620	if (cpu_has_tsc) {
621		res = (((u64)(*deltatsc)) * pm_100ms);
622		do_div(res, deltapm);
623		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
624					  "PM-Timer: %lu (%ld)\n",
625					(unsigned long)res, *deltatsc);
626		*deltatsc = (long)res;
627	}
628
629	return 0;
630}
631
632static int __init calibrate_APIC_clock(void)
633{
634	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
635	void (*real_handler)(struct clock_event_device *dev);
636	unsigned long deltaj;
637	long delta, deltatsc;
638	int pm_referenced = 0;
639
640	local_irq_disable();
641
642	/* Replace the global interrupt handler */
643	real_handler = global_clock_event->event_handler;
644	global_clock_event->event_handler = lapic_cal_handler;
645
646	/*
647	 * Setup the APIC counter to maximum. There is no way the lapic
648	 * can underflow in the 100ms detection time frame
649	 */
650	__setup_APIC_LVTT(0xffffffff, 0, 0);
651
652	/* Let the interrupts run */
653	local_irq_enable();
654
655	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
656		cpu_relax();
657
658	local_irq_disable();
659
660	/* Restore the real event handler */
661	global_clock_event->event_handler = real_handler;
662
663	/* Build delta t1-t2 as apic timer counts down */
664	delta = lapic_cal_t1 - lapic_cal_t2;
665	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
666
667	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
668
669	/* we trust the PM based calibration if possible */
670	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
671					&delta, &deltatsc);
672
673	/* Calculate the scaled math multiplication factor */
674	lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
675				       lapic_clockevent.shift);
676	lapic_clockevent.max_delta_ns =
677		clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
678	lapic_clockevent.min_delta_ns =
679		clockevent_delta2ns(0xF, &lapic_clockevent);
680
681	calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
682
683	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
684	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
685	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
686		    calibration_result);
687
688	if (cpu_has_tsc) {
689		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
690			    "%ld.%04ld MHz.\n",
691			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
692			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
693	}
694
695	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
696		    "%u.%04u MHz.\n",
697		    calibration_result / (1000000 / HZ),
698		    calibration_result % (1000000 / HZ));
699
700	/*
701	 * Do a sanity check on the APIC calibration result
702	 */
703	if (calibration_result < (1000000 / HZ)) {
704		local_irq_enable();
705		pr_warning("APIC frequency too slow, disabling apic timer\n");
706		return -1;
707	}
708
709	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
710
711	/*
712	 * PM timer calibration failed or not turned on
713	 * so lets try APIC timer based calibration
714	 */
715	if (!pm_referenced) {
716		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
717
718		/*
719		 * Setup the apic timer manually
720		 */
721		levt->event_handler = lapic_cal_handler;
722		lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
723		lapic_cal_loops = -1;
724
725		/* Let the interrupts run */
726		local_irq_enable();
727
728		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
729			cpu_relax();
730
731		/* Stop the lapic timer */
732		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
733
734		/* Jiffies delta */
735		deltaj = lapic_cal_j2 - lapic_cal_j1;
736		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
737
738		/* Check, if the jiffies result is consistent */
739		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
740			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
741		else
742			levt->features |= CLOCK_EVT_FEAT_DUMMY;
743	} else
744		local_irq_enable();
745
746	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
747		pr_warning("APIC timer disabled due to verification failure\n");
748			return -1;
749	}
750
751	return 0;
752}
753
754/*
755 * Setup the boot APIC
756 *
757 * Calibrate and verify the result.
758 */
759void __init setup_boot_APIC_clock(void)
760{
761	/*
762	 * The local apic timer can be disabled via the kernel
763	 * commandline or from the CPU detection code. Register the lapic
764	 * timer as a dummy clock event source on SMP systems, so the
765	 * broadcast mechanism is used. On UP systems simply ignore it.
766	 */
767	if (disable_apic_timer) {
768		pr_info("Disabling APIC timer\n");
769		/* No broadcast on UP ! */
770		if (num_possible_cpus() > 1) {
771			lapic_clockevent.mult = 1;
772			setup_APIC_timer();
773		}
774		return;
775	}
776
777	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
778		    "calibrating APIC timer ...\n");
779
780	if (calibrate_APIC_clock()) {
781		/* No broadcast on UP ! */
782		if (num_possible_cpus() > 1)
783			setup_APIC_timer();
784		return;
785	}
786
787	/*
788	 * If nmi_watchdog is set to IO_APIC, we need the
789	 * PIT/HPET going.  Otherwise register lapic as a dummy
790	 * device.
791	 */
792	lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
793
794	/* Setup the lapic or request the broadcast */
795	setup_APIC_timer();
796}
797
798void __cpuinit setup_secondary_APIC_clock(void)
799{
800	setup_APIC_timer();
801}
802
803/*
804 * The guts of the apic timer interrupt
805 */
806static void local_apic_timer_interrupt(void)
807{
808	int cpu = smp_processor_id();
809	struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
810
811	/*
812	 * Normally we should not be here till LAPIC has been initialized but
813	 * in some cases like kdump, its possible that there is a pending LAPIC
814	 * timer interrupt from previous kernel's context and is delivered in
815	 * new kernel the moment interrupts are enabled.
816	 *
817	 * Interrupts are enabled early and LAPIC is setup much later, hence
818	 * its possible that when we get here evt->event_handler is NULL.
819	 * Check for event_handler being NULL and discard the interrupt as
820	 * spurious.
821	 */
822	if (!evt->event_handler) {
823		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu);
824		/* Switch it off */
825		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
826		return;
827	}
828
829	/*
830	 * the NMI deadlock-detector uses this.
831	 */
832	inc_irq_stat(apic_timer_irqs);
833
834	evt->event_handler(evt);
835}
836
837/*
838 * Local APIC timer interrupt. This is the most natural way for doing
839 * local interrupts, but local timer interrupts can be emulated by
840 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
841 *
842 * [ if a single-CPU system runs an SMP kernel then we call the local
843 *   interrupt as well. Thus we cannot inline the local irq ... ]
844 */
845void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
846{
847	struct pt_regs *old_regs = set_irq_regs(regs);
848
849	/*
850	 * NOTE! We'd better ACK the irq immediately,
851	 * because timer handling can be slow.
852	 */
853	ack_APIC_irq();
854	/*
855	 * update_process_times() expects us to have done irq_enter().
856	 * Besides, if we don't timer interrupts ignore the global
857	 * interrupt lock, which is the WrongThing (tm) to do.
858	 */
859	exit_idle();
860	irq_enter();
861	local_apic_timer_interrupt();
862	irq_exit();
863
864	set_irq_regs(old_regs);
865}
866
867int setup_profiling_timer(unsigned int multiplier)
868{
869	return -EINVAL;
870}
871
872/*
873 * Local APIC start and shutdown
874 */
875
876/**
877 * clear_local_APIC - shutdown the local APIC
878 *
879 * This is called, when a CPU is disabled and before rebooting, so the state of
880 * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
881 * leftovers during boot.
882 */
883void clear_local_APIC(void)
884{
885	int maxlvt;
886	u32 v;
887
888	/* APIC hasn't been mapped yet */
889	if (!x2apic_mode && !apic_phys)
890		return;
891
892	maxlvt = lapic_get_maxlvt();
893	/*
894	 * Masking an LVT entry can trigger a local APIC error
895	 * if the vector is zero. Mask LVTERR first to prevent this.
896	 */
897	if (maxlvt >= 3) {
898		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
899		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
900	}
901	/*
902	 * Careful: we have to set masks only first to deassert
903	 * any level-triggered sources.
904	 */
905	v = apic_read(APIC_LVTT);
906	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
907	v = apic_read(APIC_LVT0);
908	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
909	v = apic_read(APIC_LVT1);
910	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
911	if (maxlvt >= 4) {
912		v = apic_read(APIC_LVTPC);
913		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
914	}
915
916	/* lets not touch this if we didn't frob it */
917#ifdef CONFIG_X86_THERMAL_VECTOR
918	if (maxlvt >= 5) {
919		v = apic_read(APIC_LVTTHMR);
920		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
921	}
922#endif
923#ifdef CONFIG_X86_MCE_INTEL
924	if (maxlvt >= 6) {
925		v = apic_read(APIC_LVTCMCI);
926		if (!(v & APIC_LVT_MASKED))
927			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
928	}
929#endif
930
931	/*
932	 * Clean APIC state for other OSs:
933	 */
934	apic_write(APIC_LVTT, APIC_LVT_MASKED);
935	apic_write(APIC_LVT0, APIC_LVT_MASKED);
936	apic_write(APIC_LVT1, APIC_LVT_MASKED);
937	if (maxlvt >= 3)
938		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
939	if (maxlvt >= 4)
940		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
941
942	/* Integrated APIC (!82489DX) ? */
943	if (lapic_is_integrated()) {
944		if (maxlvt > 3)
945			/* Clear ESR due to Pentium errata 3AP and 11AP */
946			apic_write(APIC_ESR, 0);
947		apic_read(APIC_ESR);
948	}
949}
950
951/**
952 * disable_local_APIC - clear and disable the local APIC
953 */
954void disable_local_APIC(void)
955{
956	unsigned int value;
957
958	/* APIC hasn't been mapped yet */
959	if (!x2apic_mode && !apic_phys)
960		return;
961
962	clear_local_APIC();
963
964	/*
965	 * Disable APIC (implies clearing of registers
966	 * for 82489DX!).
967	 */
968	value = apic_read(APIC_SPIV);
969	value &= ~APIC_SPIV_APIC_ENABLED;
970	apic_write(APIC_SPIV, value);
971
972#ifdef CONFIG_X86_32
973	/*
974	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
975	 * restore the disabled state.
976	 */
977	if (enabled_via_apicbase) {
978		unsigned int l, h;
979
980		rdmsr(MSR_IA32_APICBASE, l, h);
981		l &= ~MSR_IA32_APICBASE_ENABLE;
982		wrmsr(MSR_IA32_APICBASE, l, h);
983	}
984#endif
985}
986
987/*
988 * If Linux enabled the LAPIC against the BIOS default disable it down before
989 * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
990 * not power-off.  Additionally clear all LVT entries before disable_local_APIC
991 * for the case where Linux didn't enable the LAPIC.
992 */
993void lapic_shutdown(void)
994{
995	unsigned long flags;
996
997	if (!cpu_has_apic && !apic_from_smp_config())
998		return;
999
1000	local_irq_save(flags);
1001
1002#ifdef CONFIG_X86_32
1003	if (!enabled_via_apicbase)
1004		clear_local_APIC();
1005	else
1006#endif
1007		disable_local_APIC();
1008
1009
1010	local_irq_restore(flags);
1011}
1012
1013/*
1014 * This is to verify that we're looking at a real local APIC.
1015 * Check these against your board if the CPUs aren't getting
1016 * started for no apparent reason.
1017 */
1018int __init verify_local_APIC(void)
1019{
1020	unsigned int reg0, reg1;
1021
1022	/*
1023	 * The version register is read-only in a real APIC.
1024	 */
1025	reg0 = apic_read(APIC_LVR);
1026	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
1027	apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
1028	reg1 = apic_read(APIC_LVR);
1029	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
1030
1031	/*
1032	 * The two version reads above should print the same
1033	 * numbers.  If the second one is different, then we
1034	 * poke at a non-APIC.
1035	 */
1036	if (reg1 != reg0)
1037		return 0;
1038
1039	/*
1040	 * Check if the version looks reasonably.
1041	 */
1042	reg1 = GET_APIC_VERSION(reg0);
1043	if (reg1 == 0x00 || reg1 == 0xff)
1044		return 0;
1045	reg1 = lapic_get_maxlvt();
1046	if (reg1 < 0x02 || reg1 == 0xff)
1047		return 0;
1048
1049	/*
1050	 * The ID register is read/write in a real APIC.
1051	 */
1052	reg0 = apic_read(APIC_ID);
1053	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
1054	apic_write(APIC_ID, reg0 ^ apic->apic_id_mask);
1055	reg1 = apic_read(APIC_ID);
1056	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
1057	apic_write(APIC_ID, reg0);
1058	if (reg1 != (reg0 ^ apic->apic_id_mask))
1059		return 0;
1060
1061	/*
1062	 * The next two are just to see if we have sane values.
1063	 * They're only really relevant if we're in Virtual Wire
1064	 * compatibility mode, but most boxes are anymore.
1065	 */
1066	reg0 = apic_read(APIC_LVT0);
1067	apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
1068	reg1 = apic_read(APIC_LVT1);
1069	apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
1070
1071	return 1;
1072}
1073
1074/**
1075 * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1076 */
1077void __init sync_Arb_IDs(void)
1078{
1079	/*
1080	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1081	 * needed on AMD.
1082	 */
1083	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1084		return;
1085
1086	/*
1087	 * Wait for idle.
1088	 */
1089	apic_wait_icr_idle();
1090
1091	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1092	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1093			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1094}
1095
1096/*
1097 * An initial setup of the virtual wire mode.
1098 */
1099void __init init_bsp_APIC(void)
1100{
1101	unsigned int value;
1102
1103	/*
1104	 * Don't do the setup now if we have a SMP BIOS as the
1105	 * through-I/O-APIC virtual wire mode might be active.
1106	 */
1107	if (smp_found_config || !cpu_has_apic)
1108		return;
1109
1110	/*
1111	 * Do not trust the local APIC being empty at bootup.
1112	 */
1113	clear_local_APIC();
1114
1115	/*
1116	 * Enable APIC.
1117	 */
1118	value = apic_read(APIC_SPIV);
1119	value &= ~APIC_VECTOR_MASK;
1120	value |= APIC_SPIV_APIC_ENABLED;
1121
1122#ifdef CONFIG_X86_32
1123	/* This bit is reserved on P4/Xeon and should be cleared */
1124	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1125	    (boot_cpu_data.x86 == 15))
1126		value &= ~APIC_SPIV_FOCUS_DISABLED;
1127	else
1128#endif
1129		value |= APIC_SPIV_FOCUS_DISABLED;
1130	value |= SPURIOUS_APIC_VECTOR;
1131	apic_write(APIC_SPIV, value);
1132
1133	/*
1134	 * Set up the virtual wire mode.
1135	 */
1136	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1137	value = APIC_DM_NMI;
1138	if (!lapic_is_integrated())		/* 82489DX */
1139		value |= APIC_LVT_LEVEL_TRIGGER;
1140	apic_write(APIC_LVT1, value);
1141}
1142
1143static void __cpuinit lapic_setup_esr(void)
1144{
1145	unsigned int oldvalue, value, maxlvt;
1146
1147	if (!lapic_is_integrated()) {
1148		pr_info("No ESR for 82489DX.\n");
1149		return;
1150	}
1151
1152	if (apic->disable_esr) {
1153		/*
1154		 * Something untraceable is creating bad interrupts on
1155		 * secondary quads ... for the moment, just leave the
1156		 * ESR disabled - we can't do anything useful with the
1157		 * errors anyway - mbligh
1158		 */
1159		pr_info("Leaving ESR disabled.\n");
1160		return;
1161	}
1162
1163	maxlvt = lapic_get_maxlvt();
1164	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1165		apic_write(APIC_ESR, 0);
1166	oldvalue = apic_read(APIC_ESR);
1167
1168	/* enables sending errors */
1169	value = ERROR_APIC_VECTOR;
1170	apic_write(APIC_LVTERR, value);
1171
1172	/*
1173	 * spec says clear errors after enabling vector.
1174	 */
1175	if (maxlvt > 3)
1176		apic_write(APIC_ESR, 0);
1177	value = apic_read(APIC_ESR);
1178	if (value != oldvalue)
1179		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1180			"vector: 0x%08x  after: 0x%08x\n",
1181			oldvalue, value);
1182}
1183
1184/**
1185 * setup_local_APIC - setup the local APIC
1186 *
1187 * Used to setup local APIC while initializing BSP or bringin up APs.
1188 * Always called with preemption disabled.
1189 */
1190void __cpuinit setup_local_APIC(void)
1191{
1192	int cpu = smp_processor_id();
1193	unsigned int value, queued;
1194	int i, j, acked = 0;
1195	unsigned long long tsc = 0, ntsc;
1196	long long max_loops = cpu_khz;
1197
1198	if (cpu_has_tsc)
1199		rdtscll(tsc);
1200
1201	if (disable_apic) {
1202		disable_ioapic_support();
1203		return;
1204	}
1205
1206#ifdef CONFIG_X86_32
1207	/* Pound the ESR really hard over the head with a big hammer - mbligh */
1208	if (lapic_is_integrated() && apic->disable_esr) {
1209		apic_write(APIC_ESR, 0);
1210		apic_write(APIC_ESR, 0);
1211		apic_write(APIC_ESR, 0);
1212		apic_write(APIC_ESR, 0);
1213	}
1214#endif
1215	perf_events_lapic_init();
1216
1217	/*
1218	 * Double-check whether this APIC is really registered.
1219	 * This is meaningless in clustered apic mode, so we skip it.
1220	 */
1221	BUG_ON(!apic->apic_id_registered());
1222
1223	/*
1224	 * Intel recommends to set DFR, LDR and TPR before enabling
1225	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
1226	 * document number 292116).  So here it goes...
1227	 */
1228	apic->init_apic_ldr();
1229
1230#ifdef CONFIG_X86_32
1231	/*
1232	 * APIC LDR is initialized.  If logical_apicid mapping was
1233	 * initialized during get_smp_config(), make sure it matches the
1234	 * actual value.
1235	 */
1236	i = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
1237	WARN_ON(i != BAD_APICID && i != logical_smp_processor_id());
1238	/* always use the value from LDR */
1239	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
1240		logical_smp_processor_id();
1241
1242	/*
1243	 * Some NUMA implementations (NUMAQ) don't initialize apicid to
1244	 * node mapping during NUMA init.  Now that logical apicid is
1245	 * guaranteed to be known, give it another chance.  This is already
1246	 * a bit too late - percpu allocation has already happened without
1247	 * proper NUMA affinity.
1248	 */
1249	if (apic->x86_32_numa_cpu_node)
1250		set_apicid_to_node(early_per_cpu(x86_cpu_to_apicid, cpu),
1251				   apic->x86_32_numa_cpu_node(cpu));
1252#endif
1253
1254	/*
1255	 * Set Task Priority to 'accept all'. We never change this
1256	 * later on.
1257	 */
1258	value = apic_read(APIC_TASKPRI);
1259	value &= ~APIC_TPRI_MASK;
1260	apic_write(APIC_TASKPRI, value);
1261
1262	/*
1263	 * After a crash, we no longer service the interrupts and a pending
1264	 * interrupt from previous kernel might still have ISR bit set.
1265	 *
1266	 * Most probably by now CPU has serviced that pending interrupt and
1267	 * it might not have done the ack_APIC_irq() because it thought,
1268	 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1269	 * does not clear the ISR bit and cpu thinks it has already serivced
1270	 * the interrupt. Hence a vector might get locked. It was noticed
1271	 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1272	 */
1273	do {
1274		queued = 0;
1275		for (i = APIC_ISR_NR - 1; i >= 0; i--)
1276			queued |= apic_read(APIC_IRR + i*0x10);
1277
1278		for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1279			value = apic_read(APIC_ISR + i*0x10);
1280			for (j = 31; j >= 0; j--) {
1281				if (value & (1<<j)) {
1282					ack_APIC_irq();
1283					acked++;
1284				}
1285			}
1286		}
1287		if (acked > 256) {
1288			printk(KERN_ERR "LAPIC pending interrupts after %d EOI\n",
1289			       acked);
1290			break;
1291		}
1292		if (cpu_has_tsc) {
1293			rdtscll(ntsc);
1294			max_loops = (cpu_khz << 10) - (ntsc - tsc);
1295		} else
1296			max_loops--;
1297	} while (queued && max_loops > 0);
1298	WARN_ON(max_loops <= 0);
1299
1300	/*
1301	 * Now that we are all set up, enable the APIC
1302	 */
1303	value = apic_read(APIC_SPIV);
1304	value &= ~APIC_VECTOR_MASK;
1305	/*
1306	 * Enable APIC
1307	 */
1308	value |= APIC_SPIV_APIC_ENABLED;
1309
1310#ifdef CONFIG_X86_32
1311	/*
1312	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1313	 * certain networking cards. If high frequency interrupts are
1314	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1315	 * entry is masked/unmasked at a high rate as well then sooner or
1316	 * later IOAPIC line gets 'stuck', no more interrupts are received
1317	 * from the device. If focus CPU is disabled then the hang goes
1318	 * away, oh well :-(
1319	 *
1320	 * [ This bug can be reproduced easily with a level-triggered
1321	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1322	 *   BX chipset. ]
1323	 */
1324	/*
1325	 * Actually disabling the focus CPU check just makes the hang less
1326	 * frequent as it makes the interrupt distributon model be more
1327	 * like LRU than MRU (the short-term load is more even across CPUs).
1328	 * See also the comment in end_level_ioapic_irq().  --macro
1329	 */
1330
1331	/*
1332	 * - enable focus processor (bit==0)
1333	 * - 64bit mode always use processor focus
1334	 *   so no need to set it
1335	 */
1336	value &= ~APIC_SPIV_FOCUS_DISABLED;
1337#endif
1338
1339	/*
1340	 * Set spurious IRQ vector
1341	 */
1342	value |= SPURIOUS_APIC_VECTOR;
1343	apic_write(APIC_SPIV, value);
1344
1345	/*
1346	 * Set up LVT0, LVT1:
1347	 *
1348	 * set up through-local-APIC on the BP's LINT0. This is not
1349	 * strictly necessary in pure symmetric-IO mode, but sometimes
1350	 * we delegate interrupts to the 8259A.
1351	 */
1352	/*
1353	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1354	 */
1355	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1356	if (!cpu && (pic_mode || !value)) {
1357		value = APIC_DM_EXTINT;
1358		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
1359	} else {
1360		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1361		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
1362	}
1363	apic_write(APIC_LVT0, value);
1364
1365	/*
1366	 * only the BP should see the LINT1 NMI signal, obviously.
1367	 */
1368	if (!cpu)
1369		value = APIC_DM_NMI;
1370	else
1371		value = APIC_DM_NMI | APIC_LVT_MASKED;
1372	if (!lapic_is_integrated())		/* 82489DX */
1373		value |= APIC_LVT_LEVEL_TRIGGER;
1374	apic_write(APIC_LVT1, value);
1375
1376#ifdef CONFIG_X86_MCE_INTEL
1377	/* Recheck CMCI information after local APIC is up on CPU #0 */
1378	if (!cpu)
1379		cmci_recheck();
1380#endif
1381}
1382
1383void __cpuinit end_local_APIC_setup(void)
1384{
1385	lapic_setup_esr();
1386
1387#ifdef CONFIG_X86_32
1388	{
1389		unsigned int value;
1390		/* Disable the local apic timer */
1391		value = apic_read(APIC_LVTT);
1392		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1393		apic_write(APIC_LVTT, value);
1394	}
1395#endif
1396
1397	apic_pm_activate();
1398}
1399
1400void __init bsp_end_local_APIC_setup(void)
1401{
1402	end_local_APIC_setup();
1403
1404	/*
1405	 * Now that local APIC setup is completed for BP, configure the fault
1406	 * handling for interrupt remapping.
1407	 */
1408	if (intr_remapping_enabled)
1409		enable_drhd_fault_handling();
1410
1411}
1412
1413#ifdef CONFIG_X86_X2APIC
1414void check_x2apic(void)
1415{
1416	if (x2apic_enabled()) {
1417		pr_info("x2apic enabled by BIOS, switching to x2apic ops\n");
1418		x2apic_preenabled = x2apic_mode = 1;
1419	}
1420}
1421
1422void enable_x2apic(void)
1423{
1424	int msr, msr2;
1425
1426	if (!x2apic_mode)
1427		return;
1428
1429	rdmsr(MSR_IA32_APICBASE, msr, msr2);
1430	if (!(msr & X2APIC_ENABLE)) {
1431		printk_once(KERN_INFO "Enabling x2apic\n");
1432		wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, msr2);
1433	}
1434}
1435#endif /* CONFIG_X86_X2APIC */
1436
1437int __init enable_IR(void)
1438{
1439#ifdef CONFIG_INTR_REMAP
1440	if (!intr_remapping_supported()) {
1441		pr_debug("intr-remapping not supported\n");
1442		return 0;
1443	}
1444
1445	if (!x2apic_preenabled && skip_ioapic_setup) {
1446		pr_info("Skipped enabling intr-remap because of skipping "
1447			"io-apic setup\n");
1448		return 0;
1449	}
1450
1451	if (enable_intr_remapping(x2apic_supported()))
1452		return 0;
1453
1454	pr_info("Enabled Interrupt-remapping\n");
1455
1456	return 1;
1457
1458#endif
1459	return 0;
1460}
1461
1462void __init enable_IR_x2apic(void)
1463{
1464	unsigned long flags;
1465	int ret, x2apic_enabled = 0;
1466	int dmar_table_init_ret;
1467
1468	dmar_table_init_ret = dmar_table_init();
1469	if (dmar_table_init_ret && !x2apic_supported())
1470		return;
1471
1472	ret = save_ioapic_entries();
1473	if (ret) {
1474		pr_info("Saving IO-APIC state failed: %d\n", ret);
1475		goto out;
1476	}
1477
1478	local_irq_save(flags);
1479	legacy_pic->mask_all();
1480	mask_ioapic_entries();
1481
1482	if (dmar_table_init_ret)
1483		ret = 0;
1484	else
1485		ret = enable_IR();
1486
1487	if (!ret) {
1488		/* IR is required if there is APIC ID > 255 even when running
1489		 * under KVM
1490		 */
1491		if (max_physical_apicid > 255 ||
1492		    !hypervisor_x2apic_available())
1493			goto nox2apic;
1494		/*
1495		 * without IR all CPUs can be addressed by IOAPIC/MSI
1496		 * only in physical mode
1497		 */
1498		x2apic_force_phys();
1499	}
1500
1501	x2apic_enabled = 1;
1502
1503	if (x2apic_supported() && !x2apic_mode) {
1504		x2apic_mode = 1;
1505		enable_x2apic();
1506		pr_info("Enabled x2apic\n");
1507	}
1508
1509nox2apic:
1510	if (!ret) /* IR enabling failed */
1511		restore_ioapic_entries();
1512	legacy_pic->restore_mask();
1513	local_irq_restore(flags);
1514
1515out:
1516	if (x2apic_enabled)
1517		return;
1518
1519	if (x2apic_preenabled)
1520		panic("x2apic: enabled by BIOS but kernel init failed.");
1521	else if (cpu_has_x2apic)
1522		pr_info("Not enabling x2apic, Intr-remapping init failed.\n");
1523}
1524
1525#ifdef CONFIG_X86_64
1526/*
1527 * Detect and enable local APICs on non-SMP boards.
1528 * Original code written by Keir Fraser.
1529 * On AMD64 we trust the BIOS - if it says no APIC it is likely
1530 * not correctly set up (usually the APIC timer won't work etc.)
1531 */
1532static int __init detect_init_APIC(void)
1533{
1534	if (!cpu_has_apic) {
1535		pr_info("No local APIC present\n");
1536		return -1;
1537	}
1538
1539	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1540	return 0;
1541}
1542#else
1543
1544static int __init apic_verify(void)
1545{
1546	u32 features, h, l;
1547
1548	/*
1549	 * The APIC feature bit should now be enabled
1550	 * in `cpuid'
1551	 */
1552	features = cpuid_edx(1);
1553	if (!(features & (1 << X86_FEATURE_APIC))) {
1554		pr_warning("Could not enable APIC!\n");
1555		return -1;
1556	}
1557	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1558	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1559
1560	/* The BIOS may have set up the APIC at some other address */
1561	rdmsr(MSR_IA32_APICBASE, l, h);
1562	if (l & MSR_IA32_APICBASE_ENABLE)
1563		mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1564
1565	pr_info("Found and enabled local APIC!\n");
1566	return 0;
1567}
1568
1569int __init apic_force_enable(unsigned long addr)
1570{
1571	u32 h, l;
1572
1573	if (disable_apic)
1574		return -1;
1575
1576	/*
1577	 * Some BIOSes disable the local APIC in the APIC_BASE
1578	 * MSR. This can only be done in software for Intel P6 or later
1579	 * and AMD K7 (Model > 1) or later.
1580	 */
1581	rdmsr(MSR_IA32_APICBASE, l, h);
1582	if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1583		pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1584		l &= ~MSR_IA32_APICBASE_BASE;
1585		l |= MSR_IA32_APICBASE_ENABLE | addr;
1586		wrmsr(MSR_IA32_APICBASE, l, h);
1587		enabled_via_apicbase = 1;
1588	}
1589	return apic_verify();
1590}
1591
1592/*
1593 * Detect and initialize APIC
1594 */
1595static int __init detect_init_APIC(void)
1596{
1597	/* Disabled by kernel option? */
1598	if (disable_apic)
1599		return -1;
1600
1601	switch (boot_cpu_data.x86_vendor) {
1602	case X86_VENDOR_AMD:
1603		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1604		    (boot_cpu_data.x86 >= 15))
1605			break;
1606		goto no_apic;
1607	case X86_VENDOR_INTEL:
1608		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1609		    (boot_cpu_data.x86 == 5 && cpu_has_apic))
1610			break;
1611		goto no_apic;
1612	default:
1613		goto no_apic;
1614	}
1615
1616	if (!cpu_has_apic) {
1617		/*
1618		 * Over-ride BIOS and try to enable the local APIC only if
1619		 * "lapic" specified.
1620		 */
1621		if (!force_enable_local_apic) {
1622			pr_info("Local APIC disabled by BIOS -- "
1623				"you can enable it with \"lapic\"\n");
1624			return -1;
1625		}
1626		if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
1627			return -1;
1628	} else {
1629		if (apic_verify())
1630			return -1;
1631	}
1632
1633	apic_pm_activate();
1634
1635	return 0;
1636
1637no_apic:
1638	pr_info("No local APIC present or hardware disabled\n");
1639	return -1;
1640}
1641#endif
1642
1643/**
1644 * init_apic_mappings - initialize APIC mappings
1645 */
1646void __init init_apic_mappings(void)
1647{
1648	unsigned int new_apicid;
1649
1650	if (x2apic_mode) {
1651		boot_cpu_physical_apicid = read_apic_id();
1652		return;
1653	}
1654
1655	/* If no local APIC can be found return early */
1656	if (!smp_found_config && detect_init_APIC()) {
1657		/* lets NOP'ify apic operations */
1658		pr_info("APIC: disable apic facility\n");
1659		apic_disable();
1660	} else {
1661		apic_phys = mp_lapic_addr;
1662
1663		/*
1664		 * acpi lapic path already maps that address in
1665		 * acpi_register_lapic_address()
1666		 */
1667		if (!acpi_lapic && !smp_found_config)
1668			register_lapic_address(apic_phys);
1669	}
1670
1671	/*
1672	 * Fetch the APIC ID of the BSP in case we have a
1673	 * default configuration (or the MP table is broken).
1674	 */
1675	new_apicid = read_apic_id();
1676	if (boot_cpu_physical_apicid != new_apicid) {
1677		boot_cpu_physical_apicid = new_apicid;
1678		/*
1679		 * yeah -- we lie about apic_version
1680		 * in case if apic was disabled via boot option
1681		 * but it's not a problem for SMP compiled kernel
1682		 * since smp_sanity_check is prepared for such a case
1683		 * and disable smp mode
1684		 */
1685		apic_version[new_apicid] =
1686			 GET_APIC_VERSION(apic_read(APIC_LVR));
1687	}
1688}
1689
1690void __init register_lapic_address(unsigned long address)
1691{
1692	mp_lapic_addr = address;
1693
1694	if (!x2apic_mode) {
1695		set_fixmap_nocache(FIX_APIC_BASE, address);
1696		apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
1697			    APIC_BASE, mp_lapic_addr);
1698	}
1699	if (boot_cpu_physical_apicid == -1U) {
1700		boot_cpu_physical_apicid  = read_apic_id();
1701		apic_version[boot_cpu_physical_apicid] =
1702			 GET_APIC_VERSION(apic_read(APIC_LVR));
1703	}
1704}
1705
1706/*
1707 * This initializes the IO-APIC and APIC hardware if this is
1708 * a UP kernel.
1709 */
1710int apic_version[MAX_LOCAL_APIC];
1711
1712int __init APIC_init_uniprocessor(void)
1713{
1714	if (disable_apic) {
1715		pr_info("Apic disabled\n");
1716		return -1;
1717	}
1718#ifdef CONFIG_X86_64
1719	if (!cpu_has_apic) {
1720		disable_apic = 1;
1721		pr_info("Apic disabled by BIOS\n");
1722		return -1;
1723	}
1724#else
1725	if (!smp_found_config && !cpu_has_apic)
1726		return -1;
1727
1728	/*
1729	 * Complain if the BIOS pretends there is one.
1730	 */
1731	if (!cpu_has_apic &&
1732	    APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
1733		pr_err("BIOS bug, local APIC 0x%x not detected!...\n",
1734			boot_cpu_physical_apicid);
1735		return -1;
1736	}
1737#endif
1738
1739	default_setup_apic_routing();
1740
1741	verify_local_APIC();
1742	connect_bsp_APIC();
1743
1744#ifdef CONFIG_X86_64
1745	apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
1746#else
1747	/*
1748	 * Hack: In case of kdump, after a crash, kernel might be booting
1749	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
1750	 * might be zero if read from MP tables. Get it from LAPIC.
1751	 */
1752# ifdef CONFIG_CRASH_DUMP
1753	boot_cpu_physical_apicid = read_apic_id();
1754# endif
1755#endif
1756	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
1757	setup_local_APIC();
1758
1759#ifdef CONFIG_X86_IO_APIC
1760	/*
1761	 * Now enable IO-APICs, actually call clear_IO_APIC
1762	 * We need clear_IO_APIC before enabling error vector
1763	 */
1764	if (!skip_ioapic_setup && nr_ioapics)
1765		enable_IO_APIC();
1766#endif
1767
1768	bsp_end_local_APIC_setup();
1769
1770#ifdef CONFIG_X86_IO_APIC
1771	if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1772		setup_IO_APIC();
1773	else {
1774		nr_ioapics = 0;
1775	}
1776#endif
1777
1778	x86_init.timers.setup_percpu_clockev();
1779	return 0;
1780}
1781
1782/*
1783 * Local APIC interrupts
1784 */
1785
1786/*
1787 * This interrupt should _never_ happen with our APIC/SMP architecture
1788 */
1789void smp_spurious_interrupt(struct pt_regs *regs)
1790{
1791	u32 v;
1792
1793	exit_idle();
1794	irq_enter();
1795	/*
1796	 * Check if this really is a spurious interrupt and ACK it
1797	 * if it is a vectored one.  Just in case...
1798	 * Spurious interrupts should not be ACKed.
1799	 */
1800	v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1801	if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1802		ack_APIC_irq();
1803
1804	inc_irq_stat(irq_spurious_count);
1805
1806	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
1807	pr_info("spurious APIC interrupt on CPU#%d, "
1808		"should never happen.\n", smp_processor_id());
1809	irq_exit();
1810}
1811
1812/*
1813 * This interrupt should never happen with our APIC/SMP architecture
1814 */
1815void smp_error_interrupt(struct pt_regs *regs)
1816{
1817	u32 v0, v1;
1818	u32 i = 0;
1819	static const char * const error_interrupt_reason[] = {
1820		"Send CS error",		/* APIC Error Bit 0 */
1821		"Receive CS error",		/* APIC Error Bit 1 */
1822		"Send accept error",		/* APIC Error Bit 2 */
1823		"Receive accept error",		/* APIC Error Bit 3 */
1824		"Redirectable IPI",		/* APIC Error Bit 4 */
1825		"Send illegal vector",		/* APIC Error Bit 5 */
1826		"Received illegal vector",	/* APIC Error Bit 6 */
1827		"Illegal register address",	/* APIC Error Bit 7 */
1828	};
1829
1830	exit_idle();
1831	irq_enter();
1832	/* First tickle the hardware, only then report what went on. -- REW */
1833	v0 = apic_read(APIC_ESR);
1834	apic_write(APIC_ESR, 0);
1835	v1 = apic_read(APIC_ESR);
1836	ack_APIC_irq();
1837	atomic_inc(&irq_err_count);
1838
1839	apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x(%02x)",
1840		    smp_processor_id(), v0 , v1);
1841
1842	v1 = v1 & 0xff;
1843	while (v1) {
1844		if (v1 & 0x1)
1845			apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
1846		i++;
1847		v1 >>= 1;
1848	};
1849
1850	apic_printk(APIC_DEBUG, KERN_CONT "\n");
1851
1852	irq_exit();
1853}
1854
1855/**
1856 * connect_bsp_APIC - attach the APIC to the interrupt system
1857 */
1858void __init connect_bsp_APIC(void)
1859{
1860#ifdef CONFIG_X86_32
1861	if (pic_mode) {
1862		/*
1863		 * Do not trust the local APIC being empty at bootup.
1864		 */
1865		clear_local_APIC();
1866		/*
1867		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
1868		 * local APIC to INT and NMI lines.
1869		 */
1870		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
1871				"enabling APIC mode.\n");
1872		imcr_pic_to_apic();
1873	}
1874#endif
1875	if (apic->enable_apic_mode)
1876		apic->enable_apic_mode();
1877}
1878
1879/**
1880 * disconnect_bsp_APIC - detach the APIC from the interrupt system
1881 * @virt_wire_setup:	indicates, whether virtual wire mode is selected
1882 *
1883 * Virtual wire mode is necessary to deliver legacy interrupts even when the
1884 * APIC is disabled.
1885 */
1886void disconnect_bsp_APIC(int virt_wire_setup)
1887{
1888	unsigned int value;
1889
1890#ifdef CONFIG_X86_32
1891	if (pic_mode) {
1892		/*
1893		 * Put the board back into PIC mode (has an effect only on
1894		 * certain older boards).  Note that APIC interrupts, including
1895		 * IPIs, won't work beyond this point!  The only exception are
1896		 * INIT IPIs.
1897		 */
1898		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
1899				"entering PIC mode.\n");
1900		imcr_apic_to_pic();
1901		return;
1902	}
1903#endif
1904
1905	/* Go back to Virtual Wire compatibility mode */
1906
1907	/* For the spurious interrupt use vector F, and enable it */
1908	value = apic_read(APIC_SPIV);
1909	value &= ~APIC_VECTOR_MASK;
1910	value |= APIC_SPIV_APIC_ENABLED;
1911	value |= 0xf;
1912	apic_write(APIC_SPIV, value);
1913
1914	if (!virt_wire_setup) {
1915		/*
1916		 * For LVT0 make it edge triggered, active high,
1917		 * external and enabled
1918		 */
1919		value = apic_read(APIC_LVT0);
1920		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1921			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1922			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1923		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1924		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1925		apic_write(APIC_LVT0, value);
1926	} else {
1927		/* Disable LVT0 */
1928		apic_write(APIC_LVT0, APIC_LVT_MASKED);
1929	}
1930
1931	/*
1932	 * For LVT1 make it edge triggered, active high,
1933	 * nmi and enabled
1934	 */
1935	value = apic_read(APIC_LVT1);
1936	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1937			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1938			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1939	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1940	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1941	apic_write(APIC_LVT1, value);
1942}
1943
1944void __cpuinit generic_processor_info(int apicid, int version)
1945{
1946	int cpu;
1947
1948	if (num_processors >= nr_cpu_ids) {
1949		int max = nr_cpu_ids;
1950		int thiscpu = max + disabled_cpus;
1951
1952		pr_warning(
1953			"ACPI: NR_CPUS/possible_cpus limit of %i reached."
1954			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
1955
1956		disabled_cpus++;
1957		return;
1958	}
1959
1960	num_processors++;
1961	if (apicid == boot_cpu_physical_apicid) {
1962		/*
1963		 * x86_bios_cpu_apicid is required to have processors listed
1964		 * in same order as logical cpu numbers. Hence the first
1965		 * entry is BSP, and so on.
1966		 * boot_cpu_init() already hold bit 0 in cpu_present_mask
1967		 * for BSP.
1968		 */
1969		cpu = 0;
1970	} else
1971		cpu = cpumask_next_zero(-1, cpu_present_mask);
1972
1973	/*
1974	 * Validate version
1975	 */
1976	if (version == 0x0) {
1977		pr_warning("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
1978			   cpu, apicid);
1979		version = 0x10;
1980	}
1981	apic_version[apicid] = version;
1982
1983	if (version != apic_version[boot_cpu_physical_apicid]) {
1984		pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
1985			apic_version[boot_cpu_physical_apicid], cpu, version);
1986	}
1987
1988	physid_set(apicid, phys_cpu_present_map);
1989	if (apicid > max_physical_apicid)
1990		max_physical_apicid = apicid;
1991
1992#if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
1993	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
1994	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
1995#endif
1996#ifdef CONFIG_X86_32
1997	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
1998		apic->x86_32_early_logical_apicid(cpu);
1999#endif
2000	set_cpu_possible(cpu, true);
2001	set_cpu_present(cpu, true);
2002}
2003
2004int hard_smp_processor_id(void)
2005{
2006	return read_apic_id();
2007}
2008
2009void default_init_apic_ldr(void)
2010{
2011	unsigned long val;
2012
2013	apic_write(APIC_DFR, APIC_DFR_VALUE);
2014	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
2015	val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
2016	apic_write(APIC_LDR, val);
2017}
2018
2019/*
2020 * Power management
2021 */
2022#ifdef CONFIG_PM
2023
2024static struct {
2025	/*
2026	 * 'active' is true if the local APIC was enabled by us and
2027	 * not the BIOS; this signifies that we are also responsible
2028	 * for disabling it before entering apm/acpi suspend
2029	 */
2030	int active;
2031	/* r/w apic fields */
2032	unsigned int apic_id;
2033	unsigned int apic_taskpri;
2034	unsigned int apic_ldr;
2035	unsigned int apic_dfr;
2036	unsigned int apic_spiv;
2037	unsigned int apic_lvtt;
2038	unsigned int apic_lvtpc;
2039	unsigned int apic_lvt0;
2040	unsigned int apic_lvt1;
2041	unsigned int apic_lvterr;
2042	unsigned int apic_tmict;
2043	unsigned int apic_tdcr;
2044	unsigned int apic_thmr;
2045} apic_pm_state;
2046
2047static int lapic_suspend(void)
2048{
2049	unsigned long flags;
2050	int maxlvt;
2051
2052	if (!apic_pm_state.active)
2053		return 0;
2054
2055	maxlvt = lapic_get_maxlvt();
2056
2057	apic_pm_state.apic_id = apic_read(APIC_ID);
2058	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2059	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2060	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2061	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2062	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2063	if (maxlvt >= 4)
2064		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2065	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2066	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2067	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2068	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2069	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2070#ifdef CONFIG_X86_THERMAL_VECTOR
2071	if (maxlvt >= 5)
2072		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2073#endif
2074
2075	local_irq_save(flags);
2076	disable_local_APIC();
2077
2078	if (intr_remapping_enabled)
2079		disable_intr_remapping();
2080
2081	local_irq_restore(flags);
2082	return 0;
2083}
2084
2085static void lapic_resume(void)
2086{
2087	unsigned int l, h;
2088	unsigned long flags;
2089	int maxlvt;
2090
2091	if (!apic_pm_state.active)
2092		return;
2093
2094	local_irq_save(flags);
2095	if (intr_remapping_enabled) {
2096		/*
2097		 * IO-APIC and PIC have their own resume routines.
2098		 * We just mask them here to make sure the interrupt
2099		 * subsystem is completely quiet while we enable x2apic
2100		 * and interrupt-remapping.
2101		 */
2102		mask_ioapic_entries();
2103		legacy_pic->mask_all();
2104	}
2105
2106	if (x2apic_mode)
2107		enable_x2apic();
2108	else {
2109		/*
2110		 * Make sure the APICBASE points to the right address
2111		 *
2112		 * FIXME! This will be wrong if we ever support suspend on
2113		 * SMP! We'll need to do this as part of the CPU restore!
2114		 */
2115		rdmsr(MSR_IA32_APICBASE, l, h);
2116		l &= ~MSR_IA32_APICBASE_BASE;
2117		l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2118		wrmsr(MSR_IA32_APICBASE, l, h);
2119	}
2120
2121	maxlvt = lapic_get_maxlvt();
2122	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2123	apic_write(APIC_ID, apic_pm_state.apic_id);
2124	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2125	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2126	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2127	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2128	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2129	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2130#if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
2131	if (maxlvt >= 5)
2132		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2133#endif
2134	if (maxlvt >= 4)
2135		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2136	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2137	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2138	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2139	apic_write(APIC_ESR, 0);
2140	apic_read(APIC_ESR);
2141	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2142	apic_write(APIC_ESR, 0);
2143	apic_read(APIC_ESR);
2144
2145	if (intr_remapping_enabled)
2146		reenable_intr_remapping(x2apic_mode);
2147
2148	local_irq_restore(flags);
2149}
2150
2151/*
2152 * This device has no shutdown method - fully functioning local APICs
2153 * are needed on every CPU up until machine_halt/restart/poweroff.
2154 */
2155
2156static struct syscore_ops lapic_syscore_ops = {
2157	.resume		= lapic_resume,
2158	.suspend	= lapic_suspend,
2159};
2160
2161static void __cpuinit apic_pm_activate(void)
2162{
2163	apic_pm_state.active = 1;
2164}
2165
2166static int __init init_lapic_sysfs(void)
2167{
2168	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2169	if (cpu_has_apic)
2170		register_syscore_ops(&lapic_syscore_ops);
2171
2172	return 0;
2173}
2174
2175/* local apic needs to resume before other devices access its registers. */
2176core_initcall(init_lapic_sysfs);
2177
2178#else	/* CONFIG_PM */
2179
2180static void apic_pm_activate(void) { }
2181
2182#endif	/* CONFIG_PM */
2183
2184#ifdef CONFIG_X86_64
2185
2186static int __cpuinit apic_cluster_num(void)
2187{
2188	int i, clusters, zeros;
2189	unsigned id;
2190	u16 *bios_cpu_apicid;
2191	DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
2192
2193	bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
2194	bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
2195
2196	for (i = 0; i < nr_cpu_ids; i++) {
2197		/* are we being called early in kernel startup? */
2198		if (bios_cpu_apicid) {
2199			id = bios_cpu_apicid[i];
2200		} else if (i < nr_cpu_ids) {
2201			if (cpu_present(i))
2202				id = per_cpu(x86_bios_cpu_apicid, i);
2203			else
2204				continue;
2205		} else
2206			break;
2207
2208		if (id != BAD_APICID)
2209			__set_bit(APIC_CLUSTERID(id), clustermap);
2210	}
2211
2212	/* Problem:  Partially populated chassis may not have CPUs in some of
2213	 * the APIC clusters they have been allocated.  Only present CPUs have
2214	 * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap.
2215	 * Since clusters are allocated sequentially, count zeros only if
2216	 * they are bounded by ones.
2217	 */
2218	clusters = 0;
2219	zeros = 0;
2220	for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
2221		if (test_bit(i, clustermap)) {
2222			clusters += 1 + zeros;
2223			zeros = 0;
2224		} else
2225			++zeros;
2226	}
2227
2228	return clusters;
2229}
2230
2231static int __cpuinitdata multi_checked;
2232static int __cpuinitdata multi;
2233
2234static int __cpuinit set_multi(const struct dmi_system_id *d)
2235{
2236	if (multi)
2237		return 0;
2238	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2239	multi = 1;
2240	return 0;
2241}
2242
2243static const __cpuinitconst struct dmi_system_id multi_dmi_table[] = {
2244	{
2245		.callback = set_multi,
2246		.ident = "IBM System Summit2",
2247		.matches = {
2248			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2249			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2250		},
2251	},
2252	{}
2253};
2254
2255static void __cpuinit dmi_check_multi(void)
2256{
2257	if (multi_checked)
2258		return;
2259
2260	dmi_check_system(multi_dmi_table);
2261	multi_checked = 1;
2262}
2263
2264/*
2265 * apic_is_clustered_box() -- Check if we can expect good TSC
2266 *
2267 * Thus far, the major user of this is IBM's Summit2 series:
2268 * Clustered boxes may have unsynced TSC problems if they are
2269 * multi-chassis.
2270 * Use DMI to check them
2271 */
2272__cpuinit int apic_is_clustered_box(void)
2273{
2274	dmi_check_multi();
2275	if (multi)
2276		return 1;
2277
2278	if (!is_vsmp_box())
2279		return 0;
2280
2281	/*
2282	 * ScaleMP vSMPowered boxes have one cluster per board and TSCs are
2283	 * not guaranteed to be synced between boards
2284	 */
2285	if (apic_cluster_num() > 1)
2286		return 1;
2287
2288	return 0;
2289}
2290#endif
2291
2292/*
2293 * APIC command line parameters
2294 */
2295static int __init setup_disableapic(char *arg)
2296{
2297	disable_apic = 1;
2298	setup_clear_cpu_cap(X86_FEATURE_APIC);
2299	return 0;
2300}
2301early_param("disableapic", setup_disableapic);
2302
2303/* same as disableapic, for compatibility */
2304static int __init setup_nolapic(char *arg)
2305{
2306	return setup_disableapic(arg);
2307}
2308early_param("nolapic", setup_nolapic);
2309
2310static int __init parse_lapic_timer_c2_ok(char *arg)
2311{
2312	local_apic_timer_c2_ok = 1;
2313	return 0;
2314}
2315early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2316
2317static int __init parse_disable_apic_timer(char *arg)
2318{
2319	disable_apic_timer = 1;
2320	return 0;
2321}
2322early_param("noapictimer", parse_disable_apic_timer);
2323
2324static int __init parse_nolapic_timer(char *arg)
2325{
2326	disable_apic_timer = 1;
2327	return 0;
2328}
2329early_param("nolapic_timer", parse_nolapic_timer);
2330
2331static int __init apic_set_verbosity(char *arg)
2332{
2333	if (!arg)  {
2334#ifdef CONFIG_X86_64
2335		skip_ioapic_setup = 0;
2336		return 0;
2337#endif
2338		return -EINVAL;
2339	}
2340
2341	if (strcmp("debug", arg) == 0)
2342		apic_verbosity = APIC_DEBUG;
2343	else if (strcmp("verbose", arg) == 0)
2344		apic_verbosity = APIC_VERBOSE;
2345	else {
2346		pr_warning("APIC Verbosity level %s not recognised"
2347			" use apic=verbose or apic=debug\n", arg);
2348		return -EINVAL;
2349	}
2350
2351	return 0;
2352}
2353early_param("apic", apic_set_verbosity);
2354
2355static int __init lapic_insert_resource(void)
2356{
2357	if (!apic_phys)
2358		return -1;
2359
2360	/* Put local APIC into the resource map. */
2361	lapic_resource.start = apic_phys;
2362	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2363	insert_resource(&iomem_resource, &lapic_resource);
2364
2365	return 0;
2366}
2367
2368/*
2369 * need call insert after e820_reserve_resources()
2370 * that is using request_resource
2371 */
2372late_initcall(lapic_insert_resource);
2373