xref: /linux/arch/x86/kernel/apic/apic.c (revision 2277ab4a1df50e05bc732fe9488d4e902bb8399a)
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_counter.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/sysdev.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/nmi.h>
35 #include <linux/smp.h>
36 #include <linux/mm.h>
37 
38 #include <asm/perf_counter.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/desc.h>
47 #include <asm/hpet.h>
48 #include <asm/idle.h>
49 #include <asm/mtrr.h>
50 #include <asm/smp.h>
51 #include <asm/mce.h>
52 
53 unsigned int num_processors;
54 
55 unsigned disabled_cpus __cpuinitdata;
56 
57 /* Processor that is doing the boot up */
58 unsigned int boot_cpu_physical_apicid = -1U;
59 
60 /*
61  * The highest APIC ID seen during enumeration.
62  *
63  * This determines the messaging protocol we can use: if all APIC IDs
64  * are in the 0 ... 7 range, then we can use logical addressing which
65  * has some performance advantages (better broadcasting).
66  *
67  * If there's an APIC ID above 8, we use physical addressing.
68  */
69 unsigned int max_physical_apicid;
70 
71 /*
72  * Bitmask of physically existing CPUs:
73  */
74 physid_mask_t phys_cpu_present_map;
75 
76 /*
77  * Map cpu index to physical APIC ID
78  */
79 DEFINE_EARLY_PER_CPU(u16, x86_cpu_to_apicid, BAD_APICID);
80 DEFINE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid, BAD_APICID);
81 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
82 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
83 
84 #ifdef CONFIG_X86_32
85 /*
86  * Knob to control our willingness to enable the local APIC.
87  *
88  * +1=force-enable
89  */
90 static int force_enable_local_apic;
91 /*
92  * APIC command line parameters
93  */
94 static int __init parse_lapic(char *arg)
95 {
96 	force_enable_local_apic = 1;
97 	return 0;
98 }
99 early_param("lapic", parse_lapic);
100 /* Local APIC was disabled by the BIOS and enabled by the kernel */
101 static int enabled_via_apicbase;
102 
103 /*
104  * Handle interrupt mode configuration register (IMCR).
105  * This register controls whether the interrupt signals
106  * that reach the BSP come from the master PIC or from the
107  * local APIC. Before entering Symmetric I/O Mode, either
108  * the BIOS or the operating system must switch out of
109  * PIC Mode by changing the IMCR.
110  */
111 static inline void imcr_pic_to_apic(void)
112 {
113 	/* select IMCR register */
114 	outb(0x70, 0x22);
115 	/* NMI and 8259 INTR go through APIC */
116 	outb(0x01, 0x23);
117 }
118 
119 static inline void imcr_apic_to_pic(void)
120 {
121 	/* select IMCR register */
122 	outb(0x70, 0x22);
123 	/* NMI and 8259 INTR go directly to BSP */
124 	outb(0x00, 0x23);
125 }
126 #endif
127 
128 #ifdef CONFIG_X86_64
129 static int apic_calibrate_pmtmr __initdata;
130 static __init int setup_apicpmtimer(char *s)
131 {
132 	apic_calibrate_pmtmr = 1;
133 	notsc_setup(NULL);
134 	return 0;
135 }
136 __setup("apicpmtimer", setup_apicpmtimer);
137 #endif
138 
139 int x2apic_mode;
140 #ifdef CONFIG_X86_X2APIC
141 /* x2apic enabled before OS handover */
142 static int x2apic_preenabled;
143 static __init int setup_nox2apic(char *str)
144 {
145 	if (x2apic_enabled()) {
146 		pr_warning("Bios already enabled x2apic, "
147 			   "can't enforce nox2apic");
148 		return 0;
149 	}
150 
151 	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
152 	return 0;
153 }
154 early_param("nox2apic", setup_nox2apic);
155 #endif
156 
157 unsigned long mp_lapic_addr;
158 int disable_apic;
159 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
160 static int disable_apic_timer __cpuinitdata;
161 /* Local APIC timer works in C2 */
162 int local_apic_timer_c2_ok;
163 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
164 
165 int first_system_vector = 0xfe;
166 
167 /*
168  * Debug level, exported for io_apic.c
169  */
170 unsigned int apic_verbosity;
171 
172 int pic_mode;
173 
174 /* Have we found an MP table */
175 int smp_found_config;
176 
177 static struct resource lapic_resource = {
178 	.name = "Local APIC",
179 	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
180 };
181 
182 static unsigned int calibration_result;
183 
184 static int lapic_next_event(unsigned long delta,
185 			    struct clock_event_device *evt);
186 static void lapic_timer_setup(enum clock_event_mode mode,
187 			      struct clock_event_device *evt);
188 static void lapic_timer_broadcast(const struct cpumask *mask);
189 static void apic_pm_activate(void);
190 
191 /*
192  * The local apic timer can be used for any function which is CPU local.
193  */
194 static struct clock_event_device lapic_clockevent = {
195 	.name		= "lapic",
196 	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
197 			| CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
198 	.shift		= 32,
199 	.set_mode	= lapic_timer_setup,
200 	.set_next_event	= lapic_next_event,
201 	.broadcast	= lapic_timer_broadcast,
202 	.rating		= 100,
203 	.irq		= -1,
204 };
205 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
206 
207 static unsigned long apic_phys;
208 
209 /*
210  * Get the LAPIC version
211  */
212 static inline int lapic_get_version(void)
213 {
214 	return GET_APIC_VERSION(apic_read(APIC_LVR));
215 }
216 
217 /*
218  * Check, if the APIC is integrated or a separate chip
219  */
220 static inline int lapic_is_integrated(void)
221 {
222 #ifdef CONFIG_X86_64
223 	return 1;
224 #else
225 	return APIC_INTEGRATED(lapic_get_version());
226 #endif
227 }
228 
229 /*
230  * Check, whether this is a modern or a first generation APIC
231  */
232 static int modern_apic(void)
233 {
234 	/* AMD systems use old APIC versions, so check the CPU */
235 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
236 	    boot_cpu_data.x86 >= 0xf)
237 		return 1;
238 	return lapic_get_version() >= 0x14;
239 }
240 
241 /*
242  * bare function to substitute write operation
243  * and it's _that_ fast :)
244  */
245 static void native_apic_write_dummy(u32 reg, u32 v)
246 {
247 	WARN_ON_ONCE((cpu_has_apic || !disable_apic));
248 }
249 
250 static u32 native_apic_read_dummy(u32 reg)
251 {
252 	WARN_ON_ONCE((cpu_has_apic && !disable_apic));
253 	return 0;
254 }
255 
256 /*
257  * right after this call apic->write/read doesn't do anything
258  * note that there is no restore operation it works one way
259  */
260 void apic_disable(void)
261 {
262 	apic->read = native_apic_read_dummy;
263 	apic->write = native_apic_write_dummy;
264 }
265 
266 void native_apic_wait_icr_idle(void)
267 {
268 	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
269 		cpu_relax();
270 }
271 
272 u32 native_safe_apic_wait_icr_idle(void)
273 {
274 	u32 send_status;
275 	int timeout;
276 
277 	timeout = 0;
278 	do {
279 		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
280 		if (!send_status)
281 			break;
282 		udelay(100);
283 	} while (timeout++ < 1000);
284 
285 	return send_status;
286 }
287 
288 void native_apic_icr_write(u32 low, u32 id)
289 {
290 	apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
291 	apic_write(APIC_ICR, low);
292 }
293 
294 u64 native_apic_icr_read(void)
295 {
296 	u32 icr1, icr2;
297 
298 	icr2 = apic_read(APIC_ICR2);
299 	icr1 = apic_read(APIC_ICR);
300 
301 	return icr1 | ((u64)icr2 << 32);
302 }
303 
304 /**
305  * enable_NMI_through_LVT0 - enable NMI through local vector table 0
306  */
307 void __cpuinit enable_NMI_through_LVT0(void)
308 {
309 	unsigned int v;
310 
311 	/* unmask and set to NMI */
312 	v = APIC_DM_NMI;
313 
314 	/* Level triggered for 82489DX (32bit mode) */
315 	if (!lapic_is_integrated())
316 		v |= APIC_LVT_LEVEL_TRIGGER;
317 
318 	apic_write(APIC_LVT0, v);
319 }
320 
321 #ifdef CONFIG_X86_32
322 /**
323  * get_physical_broadcast - Get number of physical broadcast IDs
324  */
325 int get_physical_broadcast(void)
326 {
327 	return modern_apic() ? 0xff : 0xf;
328 }
329 #endif
330 
331 /**
332  * lapic_get_maxlvt - get the maximum number of local vector table entries
333  */
334 int lapic_get_maxlvt(void)
335 {
336 	unsigned int v;
337 
338 	v = apic_read(APIC_LVR);
339 	/*
340 	 * - we always have APIC integrated on 64bit mode
341 	 * - 82489DXs do not report # of LVT entries
342 	 */
343 	return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
344 }
345 
346 /*
347  * Local APIC timer
348  */
349 
350 /* Clock divisor */
351 #define APIC_DIVISOR 16
352 
353 /*
354  * This function sets up the local APIC timer, with a timeout of
355  * 'clocks' APIC bus clock. During calibration we actually call
356  * this function twice on the boot CPU, once with a bogus timeout
357  * value, second time for real. The other (noncalibrating) CPUs
358  * call this function only once, with the real, calibrated value.
359  *
360  * We do reads before writes even if unnecessary, to get around the
361  * P5 APIC double write bug.
362  */
363 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
364 {
365 	unsigned int lvtt_value, tmp_value;
366 
367 	lvtt_value = LOCAL_TIMER_VECTOR;
368 	if (!oneshot)
369 		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
370 	if (!lapic_is_integrated())
371 		lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
372 
373 	if (!irqen)
374 		lvtt_value |= APIC_LVT_MASKED;
375 
376 	apic_write(APIC_LVTT, lvtt_value);
377 
378 	/*
379 	 * Divide PICLK by 16
380 	 */
381 	tmp_value = apic_read(APIC_TDCR);
382 	apic_write(APIC_TDCR,
383 		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
384 		APIC_TDR_DIV_16);
385 
386 	if (!oneshot)
387 		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
388 }
389 
390 /*
391  * Setup extended LVT, AMD specific (K8, family 10h)
392  *
393  * Vector mappings are hard coded. On K8 only offset 0 (APIC500) and
394  * MCE interrupts are supported. Thus MCE offset must be set to 0.
395  *
396  * If mask=1, the LVT entry does not generate interrupts while mask=0
397  * enables the vector. See also the BKDGs.
398  */
399 
400 #define APIC_EILVT_LVTOFF_MCE 0
401 #define APIC_EILVT_LVTOFF_IBS 1
402 
403 static void setup_APIC_eilvt(u8 lvt_off, u8 vector, u8 msg_type, u8 mask)
404 {
405 	unsigned long reg = (lvt_off << 4) + APIC_EILVTn(0);
406 	unsigned int  v   = (mask << 16) | (msg_type << 8) | vector;
407 
408 	apic_write(reg, v);
409 }
410 
411 u8 setup_APIC_eilvt_mce(u8 vector, u8 msg_type, u8 mask)
412 {
413 	setup_APIC_eilvt(APIC_EILVT_LVTOFF_MCE, vector, msg_type, mask);
414 	return APIC_EILVT_LVTOFF_MCE;
415 }
416 
417 u8 setup_APIC_eilvt_ibs(u8 vector, u8 msg_type, u8 mask)
418 {
419 	setup_APIC_eilvt(APIC_EILVT_LVTOFF_IBS, vector, msg_type, mask);
420 	return APIC_EILVT_LVTOFF_IBS;
421 }
422 EXPORT_SYMBOL_GPL(setup_APIC_eilvt_ibs);
423 
424 /*
425  * Program the next event, relative to now
426  */
427 static int lapic_next_event(unsigned long delta,
428 			    struct clock_event_device *evt)
429 {
430 	apic_write(APIC_TMICT, delta);
431 	return 0;
432 }
433 
434 /*
435  * Setup the lapic timer in periodic or oneshot mode
436  */
437 static void lapic_timer_setup(enum clock_event_mode mode,
438 			      struct clock_event_device *evt)
439 {
440 	unsigned long flags;
441 	unsigned int v;
442 
443 	/* Lapic used as dummy for broadcast ? */
444 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
445 		return;
446 
447 	local_irq_save(flags);
448 
449 	switch (mode) {
450 	case CLOCK_EVT_MODE_PERIODIC:
451 	case CLOCK_EVT_MODE_ONESHOT:
452 		__setup_APIC_LVTT(calibration_result,
453 				  mode != CLOCK_EVT_MODE_PERIODIC, 1);
454 		break;
455 	case CLOCK_EVT_MODE_UNUSED:
456 	case CLOCK_EVT_MODE_SHUTDOWN:
457 		v = apic_read(APIC_LVTT);
458 		v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
459 		apic_write(APIC_LVTT, v);
460 		apic_write(APIC_TMICT, 0xffffffff);
461 		break;
462 	case CLOCK_EVT_MODE_RESUME:
463 		/* Nothing to do here */
464 		break;
465 	}
466 
467 	local_irq_restore(flags);
468 }
469 
470 /*
471  * Local APIC timer broadcast function
472  */
473 static void lapic_timer_broadcast(const struct cpumask *mask)
474 {
475 #ifdef CONFIG_SMP
476 	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
477 #endif
478 }
479 
480 /*
481  * Setup the local APIC timer for this CPU. Copy the initilized values
482  * of the boot CPU and register the clock event in the framework.
483  */
484 static void __cpuinit setup_APIC_timer(void)
485 {
486 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
487 
488 	if (cpu_has(&current_cpu_data, X86_FEATURE_ARAT)) {
489 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
490 		/* Make LAPIC timer preferrable over percpu HPET */
491 		lapic_clockevent.rating = 150;
492 	}
493 
494 	memcpy(levt, &lapic_clockevent, sizeof(*levt));
495 	levt->cpumask = cpumask_of(smp_processor_id());
496 
497 	clockevents_register_device(levt);
498 }
499 
500 /*
501  * In this functions we calibrate APIC bus clocks to the external timer.
502  *
503  * We want to do the calibration only once since we want to have local timer
504  * irqs syncron. CPUs connected by the same APIC bus have the very same bus
505  * frequency.
506  *
507  * This was previously done by reading the PIT/HPET and waiting for a wrap
508  * around to find out, that a tick has elapsed. I have a box, where the PIT
509  * readout is broken, so it never gets out of the wait loop again. This was
510  * also reported by others.
511  *
512  * Monitoring the jiffies value is inaccurate and the clockevents
513  * infrastructure allows us to do a simple substitution of the interrupt
514  * handler.
515  *
516  * The calibration routine also uses the pm_timer when possible, as the PIT
517  * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
518  * back to normal later in the boot process).
519  */
520 
521 #define LAPIC_CAL_LOOPS		(HZ/10)
522 
523 static __initdata int lapic_cal_loops = -1;
524 static __initdata long lapic_cal_t1, lapic_cal_t2;
525 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
526 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
527 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
528 
529 /*
530  * Temporary interrupt handler.
531  */
532 static void __init lapic_cal_handler(struct clock_event_device *dev)
533 {
534 	unsigned long long tsc = 0;
535 	long tapic = apic_read(APIC_TMCCT);
536 	unsigned long pm = acpi_pm_read_early();
537 
538 	if (cpu_has_tsc)
539 		rdtscll(tsc);
540 
541 	switch (lapic_cal_loops++) {
542 	case 0:
543 		lapic_cal_t1 = tapic;
544 		lapic_cal_tsc1 = tsc;
545 		lapic_cal_pm1 = pm;
546 		lapic_cal_j1 = jiffies;
547 		break;
548 
549 	case LAPIC_CAL_LOOPS:
550 		lapic_cal_t2 = tapic;
551 		lapic_cal_tsc2 = tsc;
552 		if (pm < lapic_cal_pm1)
553 			pm += ACPI_PM_OVRRUN;
554 		lapic_cal_pm2 = pm;
555 		lapic_cal_j2 = jiffies;
556 		break;
557 	}
558 }
559 
560 static int __init
561 calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
562 {
563 	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
564 	const long pm_thresh = pm_100ms / 100;
565 	unsigned long mult;
566 	u64 res;
567 
568 #ifndef CONFIG_X86_PM_TIMER
569 	return -1;
570 #endif
571 
572 	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
573 
574 	/* Check, if the PM timer is available */
575 	if (!deltapm)
576 		return -1;
577 
578 	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
579 
580 	if (deltapm > (pm_100ms - pm_thresh) &&
581 	    deltapm < (pm_100ms + pm_thresh)) {
582 		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
583 		return 0;
584 	}
585 
586 	res = (((u64)deltapm) *  mult) >> 22;
587 	do_div(res, 1000000);
588 	pr_warning("APIC calibration not consistent "
589 		   "with PM-Timer: %ldms instead of 100ms\n",(long)res);
590 
591 	/* Correct the lapic counter value */
592 	res = (((u64)(*delta)) * pm_100ms);
593 	do_div(res, deltapm);
594 	pr_info("APIC delta adjusted to PM-Timer: "
595 		"%lu (%ld)\n", (unsigned long)res, *delta);
596 	*delta = (long)res;
597 
598 	/* Correct the tsc counter value */
599 	if (cpu_has_tsc) {
600 		res = (((u64)(*deltatsc)) * pm_100ms);
601 		do_div(res, deltapm);
602 		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
603 					  "PM-Timer: %lu (%ld) \n",
604 					(unsigned long)res, *deltatsc);
605 		*deltatsc = (long)res;
606 	}
607 
608 	return 0;
609 }
610 
611 static int __init calibrate_APIC_clock(void)
612 {
613 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
614 	void (*real_handler)(struct clock_event_device *dev);
615 	unsigned long deltaj;
616 	long delta, deltatsc;
617 	int pm_referenced = 0;
618 
619 	local_irq_disable();
620 
621 	/* Replace the global interrupt handler */
622 	real_handler = global_clock_event->event_handler;
623 	global_clock_event->event_handler = lapic_cal_handler;
624 
625 	/*
626 	 * Setup the APIC counter to maximum. There is no way the lapic
627 	 * can underflow in the 100ms detection time frame
628 	 */
629 	__setup_APIC_LVTT(0xffffffff, 0, 0);
630 
631 	/* Let the interrupts run */
632 	local_irq_enable();
633 
634 	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
635 		cpu_relax();
636 
637 	local_irq_disable();
638 
639 	/* Restore the real event handler */
640 	global_clock_event->event_handler = real_handler;
641 
642 	/* Build delta t1-t2 as apic timer counts down */
643 	delta = lapic_cal_t1 - lapic_cal_t2;
644 	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
645 
646 	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
647 
648 	/* we trust the PM based calibration if possible */
649 	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
650 					&delta, &deltatsc);
651 
652 	/* Calculate the scaled math multiplication factor */
653 	lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
654 				       lapic_clockevent.shift);
655 	lapic_clockevent.max_delta_ns =
656 		clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
657 	lapic_clockevent.min_delta_ns =
658 		clockevent_delta2ns(0xF, &lapic_clockevent);
659 
660 	calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
661 
662 	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
663 	apic_printk(APIC_VERBOSE, "..... mult: %ld\n", lapic_clockevent.mult);
664 	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
665 		    calibration_result);
666 
667 	if (cpu_has_tsc) {
668 		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
669 			    "%ld.%04ld MHz.\n",
670 			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
671 			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
672 	}
673 
674 	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
675 		    "%u.%04u MHz.\n",
676 		    calibration_result / (1000000 / HZ),
677 		    calibration_result % (1000000 / HZ));
678 
679 	/*
680 	 * Do a sanity check on the APIC calibration result
681 	 */
682 	if (calibration_result < (1000000 / HZ)) {
683 		local_irq_enable();
684 		pr_warning("APIC frequency too slow, disabling apic timer\n");
685 		return -1;
686 	}
687 
688 	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
689 
690 	/*
691 	 * PM timer calibration failed or not turned on
692 	 * so lets try APIC timer based calibration
693 	 */
694 	if (!pm_referenced) {
695 		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
696 
697 		/*
698 		 * Setup the apic timer manually
699 		 */
700 		levt->event_handler = lapic_cal_handler;
701 		lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
702 		lapic_cal_loops = -1;
703 
704 		/* Let the interrupts run */
705 		local_irq_enable();
706 
707 		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
708 			cpu_relax();
709 
710 		/* Stop the lapic timer */
711 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
712 
713 		/* Jiffies delta */
714 		deltaj = lapic_cal_j2 - lapic_cal_j1;
715 		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
716 
717 		/* Check, if the jiffies result is consistent */
718 		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
719 			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
720 		else
721 			levt->features |= CLOCK_EVT_FEAT_DUMMY;
722 	} else
723 		local_irq_enable();
724 
725 	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
726 		pr_warning("APIC timer disabled due to verification failure\n");
727 			return -1;
728 	}
729 
730 	return 0;
731 }
732 
733 /*
734  * Setup the boot APIC
735  *
736  * Calibrate and verify the result.
737  */
738 void __init setup_boot_APIC_clock(void)
739 {
740 	/*
741 	 * The local apic timer can be disabled via the kernel
742 	 * commandline or from the CPU detection code. Register the lapic
743 	 * timer as a dummy clock event source on SMP systems, so the
744 	 * broadcast mechanism is used. On UP systems simply ignore it.
745 	 */
746 	if (disable_apic_timer) {
747 		pr_info("Disabling APIC timer\n");
748 		/* No broadcast on UP ! */
749 		if (num_possible_cpus() > 1) {
750 			lapic_clockevent.mult = 1;
751 			setup_APIC_timer();
752 		}
753 		return;
754 	}
755 
756 	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
757 		    "calibrating APIC timer ...\n");
758 
759 	if (calibrate_APIC_clock()) {
760 		/* No broadcast on UP ! */
761 		if (num_possible_cpus() > 1)
762 			setup_APIC_timer();
763 		return;
764 	}
765 
766 	/*
767 	 * If nmi_watchdog is set to IO_APIC, we need the
768 	 * PIT/HPET going.  Otherwise register lapic as a dummy
769 	 * device.
770 	 */
771 	if (nmi_watchdog != NMI_IO_APIC)
772 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
773 	else
774 		pr_warning("APIC timer registered as dummy,"
775 			" due to nmi_watchdog=%d!\n", nmi_watchdog);
776 
777 	/* Setup the lapic or request the broadcast */
778 	setup_APIC_timer();
779 }
780 
781 void __cpuinit setup_secondary_APIC_clock(void)
782 {
783 	setup_APIC_timer();
784 }
785 
786 /*
787  * The guts of the apic timer interrupt
788  */
789 static void local_apic_timer_interrupt(void)
790 {
791 	int cpu = smp_processor_id();
792 	struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
793 
794 	/*
795 	 * Normally we should not be here till LAPIC has been initialized but
796 	 * in some cases like kdump, its possible that there is a pending LAPIC
797 	 * timer interrupt from previous kernel's context and is delivered in
798 	 * new kernel the moment interrupts are enabled.
799 	 *
800 	 * Interrupts are enabled early and LAPIC is setup much later, hence
801 	 * its possible that when we get here evt->event_handler is NULL.
802 	 * Check for event_handler being NULL and discard the interrupt as
803 	 * spurious.
804 	 */
805 	if (!evt->event_handler) {
806 		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu);
807 		/* Switch it off */
808 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
809 		return;
810 	}
811 
812 	/*
813 	 * the NMI deadlock-detector uses this.
814 	 */
815 	inc_irq_stat(apic_timer_irqs);
816 
817 	evt->event_handler(evt);
818 }
819 
820 /*
821  * Local APIC timer interrupt. This is the most natural way for doing
822  * local interrupts, but local timer interrupts can be emulated by
823  * broadcast interrupts too. [in case the hw doesn't support APIC timers]
824  *
825  * [ if a single-CPU system runs an SMP kernel then we call the local
826  *   interrupt as well. Thus we cannot inline the local irq ... ]
827  */
828 void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
829 {
830 	struct pt_regs *old_regs = set_irq_regs(regs);
831 
832 	/*
833 	 * NOTE! We'd better ACK the irq immediately,
834 	 * because timer handling can be slow.
835 	 */
836 	ack_APIC_irq();
837 	/*
838 	 * update_process_times() expects us to have done irq_enter().
839 	 * Besides, if we don't timer interrupts ignore the global
840 	 * interrupt lock, which is the WrongThing (tm) to do.
841 	 */
842 	exit_idle();
843 	irq_enter();
844 	local_apic_timer_interrupt();
845 	irq_exit();
846 
847 	set_irq_regs(old_regs);
848 }
849 
850 int setup_profiling_timer(unsigned int multiplier)
851 {
852 	return -EINVAL;
853 }
854 
855 /*
856  * Local APIC start and shutdown
857  */
858 
859 /**
860  * clear_local_APIC - shutdown the local APIC
861  *
862  * This is called, when a CPU is disabled and before rebooting, so the state of
863  * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
864  * leftovers during boot.
865  */
866 void clear_local_APIC(void)
867 {
868 	int maxlvt;
869 	u32 v;
870 
871 	/* APIC hasn't been mapped yet */
872 	if (!x2apic_mode && !apic_phys)
873 		return;
874 
875 	maxlvt = lapic_get_maxlvt();
876 	/*
877 	 * Masking an LVT entry can trigger a local APIC error
878 	 * if the vector is zero. Mask LVTERR first to prevent this.
879 	 */
880 	if (maxlvt >= 3) {
881 		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
882 		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
883 	}
884 	/*
885 	 * Careful: we have to set masks only first to deassert
886 	 * any level-triggered sources.
887 	 */
888 	v = apic_read(APIC_LVTT);
889 	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
890 	v = apic_read(APIC_LVT0);
891 	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
892 	v = apic_read(APIC_LVT1);
893 	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
894 	if (maxlvt >= 4) {
895 		v = apic_read(APIC_LVTPC);
896 		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
897 	}
898 
899 	/* lets not touch this if we didn't frob it */
900 #ifdef CONFIG_X86_THERMAL_VECTOR
901 	if (maxlvt >= 5) {
902 		v = apic_read(APIC_LVTTHMR);
903 		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
904 	}
905 #endif
906 #ifdef CONFIG_X86_MCE_INTEL
907 	if (maxlvt >= 6) {
908 		v = apic_read(APIC_LVTCMCI);
909 		if (!(v & APIC_LVT_MASKED))
910 			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
911 	}
912 #endif
913 
914 	/*
915 	 * Clean APIC state for other OSs:
916 	 */
917 	apic_write(APIC_LVTT, APIC_LVT_MASKED);
918 	apic_write(APIC_LVT0, APIC_LVT_MASKED);
919 	apic_write(APIC_LVT1, APIC_LVT_MASKED);
920 	if (maxlvt >= 3)
921 		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
922 	if (maxlvt >= 4)
923 		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
924 
925 	/* Integrated APIC (!82489DX) ? */
926 	if (lapic_is_integrated()) {
927 		if (maxlvt > 3)
928 			/* Clear ESR due to Pentium errata 3AP and 11AP */
929 			apic_write(APIC_ESR, 0);
930 		apic_read(APIC_ESR);
931 	}
932 }
933 
934 /**
935  * disable_local_APIC - clear and disable the local APIC
936  */
937 void disable_local_APIC(void)
938 {
939 	unsigned int value;
940 
941 	/* APIC hasn't been mapped yet */
942 	if (!apic_phys)
943 		return;
944 
945 	clear_local_APIC();
946 
947 	/*
948 	 * Disable APIC (implies clearing of registers
949 	 * for 82489DX!).
950 	 */
951 	value = apic_read(APIC_SPIV);
952 	value &= ~APIC_SPIV_APIC_ENABLED;
953 	apic_write(APIC_SPIV, value);
954 
955 #ifdef CONFIG_X86_32
956 	/*
957 	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
958 	 * restore the disabled state.
959 	 */
960 	if (enabled_via_apicbase) {
961 		unsigned int l, h;
962 
963 		rdmsr(MSR_IA32_APICBASE, l, h);
964 		l &= ~MSR_IA32_APICBASE_ENABLE;
965 		wrmsr(MSR_IA32_APICBASE, l, h);
966 	}
967 #endif
968 }
969 
970 /*
971  * If Linux enabled the LAPIC against the BIOS default disable it down before
972  * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
973  * not power-off.  Additionally clear all LVT entries before disable_local_APIC
974  * for the case where Linux didn't enable the LAPIC.
975  */
976 void lapic_shutdown(void)
977 {
978 	unsigned long flags;
979 
980 	if (!cpu_has_apic)
981 		return;
982 
983 	local_irq_save(flags);
984 
985 #ifdef CONFIG_X86_32
986 	if (!enabled_via_apicbase)
987 		clear_local_APIC();
988 	else
989 #endif
990 		disable_local_APIC();
991 
992 
993 	local_irq_restore(flags);
994 }
995 
996 /*
997  * This is to verify that we're looking at a real local APIC.
998  * Check these against your board if the CPUs aren't getting
999  * started for no apparent reason.
1000  */
1001 int __init verify_local_APIC(void)
1002 {
1003 	unsigned int reg0, reg1;
1004 
1005 	/*
1006 	 * The version register is read-only in a real APIC.
1007 	 */
1008 	reg0 = apic_read(APIC_LVR);
1009 	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
1010 	apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
1011 	reg1 = apic_read(APIC_LVR);
1012 	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
1013 
1014 	/*
1015 	 * The two version reads above should print the same
1016 	 * numbers.  If the second one is different, then we
1017 	 * poke at a non-APIC.
1018 	 */
1019 	if (reg1 != reg0)
1020 		return 0;
1021 
1022 	/*
1023 	 * Check if the version looks reasonably.
1024 	 */
1025 	reg1 = GET_APIC_VERSION(reg0);
1026 	if (reg1 == 0x00 || reg1 == 0xff)
1027 		return 0;
1028 	reg1 = lapic_get_maxlvt();
1029 	if (reg1 < 0x02 || reg1 == 0xff)
1030 		return 0;
1031 
1032 	/*
1033 	 * The ID register is read/write in a real APIC.
1034 	 */
1035 	reg0 = apic_read(APIC_ID);
1036 	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
1037 	apic_write(APIC_ID, reg0 ^ apic->apic_id_mask);
1038 	reg1 = apic_read(APIC_ID);
1039 	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
1040 	apic_write(APIC_ID, reg0);
1041 	if (reg1 != (reg0 ^ apic->apic_id_mask))
1042 		return 0;
1043 
1044 	/*
1045 	 * The next two are just to see if we have sane values.
1046 	 * They're only really relevant if we're in Virtual Wire
1047 	 * compatibility mode, but most boxes are anymore.
1048 	 */
1049 	reg0 = apic_read(APIC_LVT0);
1050 	apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
1051 	reg1 = apic_read(APIC_LVT1);
1052 	apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
1053 
1054 	return 1;
1055 }
1056 
1057 /**
1058  * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1059  */
1060 void __init sync_Arb_IDs(void)
1061 {
1062 	/*
1063 	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1064 	 * needed on AMD.
1065 	 */
1066 	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1067 		return;
1068 
1069 	/*
1070 	 * Wait for idle.
1071 	 */
1072 	apic_wait_icr_idle();
1073 
1074 	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1075 	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1076 			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1077 }
1078 
1079 /*
1080  * An initial setup of the virtual wire mode.
1081  */
1082 void __init init_bsp_APIC(void)
1083 {
1084 	unsigned int value;
1085 
1086 	/*
1087 	 * Don't do the setup now if we have a SMP BIOS as the
1088 	 * through-I/O-APIC virtual wire mode might be active.
1089 	 */
1090 	if (smp_found_config || !cpu_has_apic)
1091 		return;
1092 
1093 	/*
1094 	 * Do not trust the local APIC being empty at bootup.
1095 	 */
1096 	clear_local_APIC();
1097 
1098 	/*
1099 	 * Enable APIC.
1100 	 */
1101 	value = apic_read(APIC_SPIV);
1102 	value &= ~APIC_VECTOR_MASK;
1103 	value |= APIC_SPIV_APIC_ENABLED;
1104 
1105 #ifdef CONFIG_X86_32
1106 	/* This bit is reserved on P4/Xeon and should be cleared */
1107 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1108 	    (boot_cpu_data.x86 == 15))
1109 		value &= ~APIC_SPIV_FOCUS_DISABLED;
1110 	else
1111 #endif
1112 		value |= APIC_SPIV_FOCUS_DISABLED;
1113 	value |= SPURIOUS_APIC_VECTOR;
1114 	apic_write(APIC_SPIV, value);
1115 
1116 	/*
1117 	 * Set up the virtual wire mode.
1118 	 */
1119 	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1120 	value = APIC_DM_NMI;
1121 	if (!lapic_is_integrated())		/* 82489DX */
1122 		value |= APIC_LVT_LEVEL_TRIGGER;
1123 	apic_write(APIC_LVT1, value);
1124 }
1125 
1126 static void __cpuinit lapic_setup_esr(void)
1127 {
1128 	unsigned int oldvalue, value, maxlvt;
1129 
1130 	if (!lapic_is_integrated()) {
1131 		pr_info("No ESR for 82489DX.\n");
1132 		return;
1133 	}
1134 
1135 	if (apic->disable_esr) {
1136 		/*
1137 		 * Something untraceable is creating bad interrupts on
1138 		 * secondary quads ... for the moment, just leave the
1139 		 * ESR disabled - we can't do anything useful with the
1140 		 * errors anyway - mbligh
1141 		 */
1142 		pr_info("Leaving ESR disabled.\n");
1143 		return;
1144 	}
1145 
1146 	maxlvt = lapic_get_maxlvt();
1147 	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1148 		apic_write(APIC_ESR, 0);
1149 	oldvalue = apic_read(APIC_ESR);
1150 
1151 	/* enables sending errors */
1152 	value = ERROR_APIC_VECTOR;
1153 	apic_write(APIC_LVTERR, value);
1154 
1155 	/*
1156 	 * spec says clear errors after enabling vector.
1157 	 */
1158 	if (maxlvt > 3)
1159 		apic_write(APIC_ESR, 0);
1160 	value = apic_read(APIC_ESR);
1161 	if (value != oldvalue)
1162 		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1163 			"vector: 0x%08x  after: 0x%08x\n",
1164 			oldvalue, value);
1165 }
1166 
1167 
1168 /**
1169  * setup_local_APIC - setup the local APIC
1170  */
1171 void __cpuinit setup_local_APIC(void)
1172 {
1173 	unsigned int value;
1174 	int i, j;
1175 
1176 	if (disable_apic) {
1177 		arch_disable_smp_support();
1178 		return;
1179 	}
1180 
1181 #ifdef CONFIG_X86_32
1182 	/* Pound the ESR really hard over the head with a big hammer - mbligh */
1183 	if (lapic_is_integrated() && apic->disable_esr) {
1184 		apic_write(APIC_ESR, 0);
1185 		apic_write(APIC_ESR, 0);
1186 		apic_write(APIC_ESR, 0);
1187 		apic_write(APIC_ESR, 0);
1188 	}
1189 #endif
1190 	perf_counters_lapic_init();
1191 
1192 	preempt_disable();
1193 
1194 	/*
1195 	 * Double-check whether this APIC is really registered.
1196 	 * This is meaningless in clustered apic mode, so we skip it.
1197 	 */
1198 	if (!apic->apic_id_registered())
1199 		BUG();
1200 
1201 	/*
1202 	 * Intel recommends to set DFR, LDR and TPR before enabling
1203 	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
1204 	 * document number 292116).  So here it goes...
1205 	 */
1206 	apic->init_apic_ldr();
1207 
1208 	/*
1209 	 * Set Task Priority to 'accept all'. We never change this
1210 	 * later on.
1211 	 */
1212 	value = apic_read(APIC_TASKPRI);
1213 	value &= ~APIC_TPRI_MASK;
1214 	apic_write(APIC_TASKPRI, value);
1215 
1216 	/*
1217 	 * After a crash, we no longer service the interrupts and a pending
1218 	 * interrupt from previous kernel might still have ISR bit set.
1219 	 *
1220 	 * Most probably by now CPU has serviced that pending interrupt and
1221 	 * it might not have done the ack_APIC_irq() because it thought,
1222 	 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1223 	 * does not clear the ISR bit and cpu thinks it has already serivced
1224 	 * the interrupt. Hence a vector might get locked. It was noticed
1225 	 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1226 	 */
1227 	for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1228 		value = apic_read(APIC_ISR + i*0x10);
1229 		for (j = 31; j >= 0; j--) {
1230 			if (value & (1<<j))
1231 				ack_APIC_irq();
1232 		}
1233 	}
1234 
1235 	/*
1236 	 * Now that we are all set up, enable the APIC
1237 	 */
1238 	value = apic_read(APIC_SPIV);
1239 	value &= ~APIC_VECTOR_MASK;
1240 	/*
1241 	 * Enable APIC
1242 	 */
1243 	value |= APIC_SPIV_APIC_ENABLED;
1244 
1245 #ifdef CONFIG_X86_32
1246 	/*
1247 	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1248 	 * certain networking cards. If high frequency interrupts are
1249 	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1250 	 * entry is masked/unmasked at a high rate as well then sooner or
1251 	 * later IOAPIC line gets 'stuck', no more interrupts are received
1252 	 * from the device. If focus CPU is disabled then the hang goes
1253 	 * away, oh well :-(
1254 	 *
1255 	 * [ This bug can be reproduced easily with a level-triggered
1256 	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1257 	 *   BX chipset. ]
1258 	 */
1259 	/*
1260 	 * Actually disabling the focus CPU check just makes the hang less
1261 	 * frequent as it makes the interrupt distributon model be more
1262 	 * like LRU than MRU (the short-term load is more even across CPUs).
1263 	 * See also the comment in end_level_ioapic_irq().  --macro
1264 	 */
1265 
1266 	/*
1267 	 * - enable focus processor (bit==0)
1268 	 * - 64bit mode always use processor focus
1269 	 *   so no need to set it
1270 	 */
1271 	value &= ~APIC_SPIV_FOCUS_DISABLED;
1272 #endif
1273 
1274 	/*
1275 	 * Set spurious IRQ vector
1276 	 */
1277 	value |= SPURIOUS_APIC_VECTOR;
1278 	apic_write(APIC_SPIV, value);
1279 
1280 	/*
1281 	 * Set up LVT0, LVT1:
1282 	 *
1283 	 * set up through-local-APIC on the BP's LINT0. This is not
1284 	 * strictly necessary in pure symmetric-IO mode, but sometimes
1285 	 * we delegate interrupts to the 8259A.
1286 	 */
1287 	/*
1288 	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1289 	 */
1290 	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1291 	if (!smp_processor_id() && (pic_mode || !value)) {
1292 		value = APIC_DM_EXTINT;
1293 		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n",
1294 				smp_processor_id());
1295 	} else {
1296 		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1297 		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n",
1298 				smp_processor_id());
1299 	}
1300 	apic_write(APIC_LVT0, value);
1301 
1302 	/*
1303 	 * only the BP should see the LINT1 NMI signal, obviously.
1304 	 */
1305 	if (!smp_processor_id())
1306 		value = APIC_DM_NMI;
1307 	else
1308 		value = APIC_DM_NMI | APIC_LVT_MASKED;
1309 	if (!lapic_is_integrated())		/* 82489DX */
1310 		value |= APIC_LVT_LEVEL_TRIGGER;
1311 	apic_write(APIC_LVT1, value);
1312 
1313 	preempt_enable();
1314 
1315 #ifdef CONFIG_X86_MCE_INTEL
1316 	/* Recheck CMCI information after local APIC is up on CPU #0 */
1317 	if (smp_processor_id() == 0)
1318 		cmci_recheck();
1319 #endif
1320 }
1321 
1322 void __cpuinit end_local_APIC_setup(void)
1323 {
1324 	lapic_setup_esr();
1325 
1326 #ifdef CONFIG_X86_32
1327 	{
1328 		unsigned int value;
1329 		/* Disable the local apic timer */
1330 		value = apic_read(APIC_LVTT);
1331 		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1332 		apic_write(APIC_LVTT, value);
1333 	}
1334 #endif
1335 
1336 	setup_apic_nmi_watchdog(NULL);
1337 	apic_pm_activate();
1338 }
1339 
1340 #ifdef CONFIG_X86_X2APIC
1341 void check_x2apic(void)
1342 {
1343 	if (x2apic_enabled()) {
1344 		pr_info("x2apic enabled by BIOS, switching to x2apic ops\n");
1345 		x2apic_preenabled = x2apic_mode = 1;
1346 	}
1347 }
1348 
1349 void enable_x2apic(void)
1350 {
1351 	int msr, msr2;
1352 
1353 	if (!x2apic_mode)
1354 		return;
1355 
1356 	rdmsr(MSR_IA32_APICBASE, msr, msr2);
1357 	if (!(msr & X2APIC_ENABLE)) {
1358 		pr_info("Enabling x2apic\n");
1359 		wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, 0);
1360 	}
1361 }
1362 #endif /* CONFIG_X86_X2APIC */
1363 
1364 void __init enable_IR_x2apic(void)
1365 {
1366 #ifdef CONFIG_INTR_REMAP
1367 	int ret;
1368 	unsigned long flags;
1369 	struct IO_APIC_route_entry **ioapic_entries = NULL;
1370 
1371 	ret = dmar_table_init();
1372 	if (ret) {
1373 		pr_debug("dmar_table_init() failed with %d:\n", ret);
1374 		goto ir_failed;
1375 	}
1376 
1377 	if (!intr_remapping_supported()) {
1378 		pr_debug("intr-remapping not supported\n");
1379 		goto ir_failed;
1380 	}
1381 
1382 
1383 	if (!x2apic_preenabled && skip_ioapic_setup) {
1384 		pr_info("Skipped enabling intr-remap because of skipping "
1385 			"io-apic setup\n");
1386 		return;
1387 	}
1388 
1389 	ioapic_entries = alloc_ioapic_entries();
1390 	if (!ioapic_entries) {
1391 		pr_info("Allocate ioapic_entries failed: %d\n", ret);
1392 		goto end;
1393 	}
1394 
1395 	ret = save_IO_APIC_setup(ioapic_entries);
1396 	if (ret) {
1397 		pr_info("Saving IO-APIC state failed: %d\n", ret);
1398 		goto end;
1399 	}
1400 
1401 	local_irq_save(flags);
1402 	mask_IO_APIC_setup(ioapic_entries);
1403 	mask_8259A();
1404 
1405 	ret = enable_intr_remapping(x2apic_supported());
1406 	if (ret)
1407 		goto end_restore;
1408 
1409 	pr_info("Enabled Interrupt-remapping\n");
1410 
1411 	if (x2apic_supported() && !x2apic_mode) {
1412 		x2apic_mode = 1;
1413 		enable_x2apic();
1414 		pr_info("Enabled x2apic\n");
1415 	}
1416 
1417 end_restore:
1418 	if (ret)
1419 		/*
1420 		 * IR enabling failed
1421 		 */
1422 		restore_IO_APIC_setup(ioapic_entries);
1423 
1424 	unmask_8259A();
1425 	local_irq_restore(flags);
1426 
1427 end:
1428 	if (ioapic_entries)
1429 		free_ioapic_entries(ioapic_entries);
1430 
1431 	if (!ret)
1432 		return;
1433 
1434 ir_failed:
1435 	if (x2apic_preenabled)
1436 		panic("x2apic enabled by bios. But IR enabling failed");
1437 	else if (cpu_has_x2apic)
1438 		pr_info("Not enabling x2apic,Intr-remapping\n");
1439 #else
1440 	if (!cpu_has_x2apic)
1441 		return;
1442 
1443 	if (x2apic_preenabled)
1444 		panic("x2apic enabled prior OS handover,"
1445 		      " enable CONFIG_X86_X2APIC, CONFIG_INTR_REMAP");
1446 #endif
1447 
1448 	return;
1449 }
1450 
1451 
1452 #ifdef CONFIG_X86_64
1453 /*
1454  * Detect and enable local APICs on non-SMP boards.
1455  * Original code written by Keir Fraser.
1456  * On AMD64 we trust the BIOS - if it says no APIC it is likely
1457  * not correctly set up (usually the APIC timer won't work etc.)
1458  */
1459 static int __init detect_init_APIC(void)
1460 {
1461 	if (!cpu_has_apic) {
1462 		pr_info("No local APIC present\n");
1463 		return -1;
1464 	}
1465 
1466 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1467 	return 0;
1468 }
1469 #else
1470 /*
1471  * Detect and initialize APIC
1472  */
1473 static int __init detect_init_APIC(void)
1474 {
1475 	u32 h, l, features;
1476 
1477 	/* Disabled by kernel option? */
1478 	if (disable_apic)
1479 		return -1;
1480 
1481 	switch (boot_cpu_data.x86_vendor) {
1482 	case X86_VENDOR_AMD:
1483 		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1484 		    (boot_cpu_data.x86 >= 15))
1485 			break;
1486 		goto no_apic;
1487 	case X86_VENDOR_INTEL:
1488 		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1489 		    (boot_cpu_data.x86 == 5 && cpu_has_apic))
1490 			break;
1491 		goto no_apic;
1492 	default:
1493 		goto no_apic;
1494 	}
1495 
1496 	if (!cpu_has_apic) {
1497 		/*
1498 		 * Over-ride BIOS and try to enable the local APIC only if
1499 		 * "lapic" specified.
1500 		 */
1501 		if (!force_enable_local_apic) {
1502 			pr_info("Local APIC disabled by BIOS -- "
1503 				"you can enable it with \"lapic\"\n");
1504 			return -1;
1505 		}
1506 		/*
1507 		 * Some BIOSes disable the local APIC in the APIC_BASE
1508 		 * MSR. This can only be done in software for Intel P6 or later
1509 		 * and AMD K7 (Model > 1) or later.
1510 		 */
1511 		rdmsr(MSR_IA32_APICBASE, l, h);
1512 		if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1513 			pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1514 			l &= ~MSR_IA32_APICBASE_BASE;
1515 			l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE;
1516 			wrmsr(MSR_IA32_APICBASE, l, h);
1517 			enabled_via_apicbase = 1;
1518 		}
1519 	}
1520 	/*
1521 	 * The APIC feature bit should now be enabled
1522 	 * in `cpuid'
1523 	 */
1524 	features = cpuid_edx(1);
1525 	if (!(features & (1 << X86_FEATURE_APIC))) {
1526 		pr_warning("Could not enable APIC!\n");
1527 		return -1;
1528 	}
1529 	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1530 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1531 
1532 	/* The BIOS may have set up the APIC at some other address */
1533 	rdmsr(MSR_IA32_APICBASE, l, h);
1534 	if (l & MSR_IA32_APICBASE_ENABLE)
1535 		mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1536 
1537 	pr_info("Found and enabled local APIC!\n");
1538 
1539 	apic_pm_activate();
1540 
1541 	return 0;
1542 
1543 no_apic:
1544 	pr_info("No local APIC present or hardware disabled\n");
1545 	return -1;
1546 }
1547 #endif
1548 
1549 #ifdef CONFIG_X86_64
1550 void __init early_init_lapic_mapping(void)
1551 {
1552 	unsigned long phys_addr;
1553 
1554 	/*
1555 	 * If no local APIC can be found then go out
1556 	 * : it means there is no mpatable and MADT
1557 	 */
1558 	if (!smp_found_config)
1559 		return;
1560 
1561 	phys_addr = mp_lapic_addr;
1562 
1563 	set_fixmap_nocache(FIX_APIC_BASE, phys_addr);
1564 	apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
1565 		    APIC_BASE, phys_addr);
1566 
1567 	/*
1568 	 * Fetch the APIC ID of the BSP in case we have a
1569 	 * default configuration (or the MP table is broken).
1570 	 */
1571 	boot_cpu_physical_apicid = read_apic_id();
1572 }
1573 #endif
1574 
1575 /**
1576  * init_apic_mappings - initialize APIC mappings
1577  */
1578 void __init init_apic_mappings(void)
1579 {
1580 	unsigned int new_apicid;
1581 
1582 	if (x2apic_mode) {
1583 		boot_cpu_physical_apicid = read_apic_id();
1584 		return;
1585 	}
1586 
1587 	/* If no local APIC can be found return early */
1588 	if (!smp_found_config && detect_init_APIC()) {
1589 		/* lets NOP'ify apic operations */
1590 		pr_info("APIC: disable apic facility\n");
1591 		apic_disable();
1592 	} else {
1593 		apic_phys = mp_lapic_addr;
1594 
1595 		/*
1596 		 * acpi lapic path already maps that address in
1597 		 * acpi_register_lapic_address()
1598 		 */
1599 		if (!acpi_lapic)
1600 			set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
1601 
1602 		apic_printk(APIC_VERBOSE, "mapped APIC to %08lx (%08lx)\n",
1603 					APIC_BASE, apic_phys);
1604 	}
1605 
1606 	/*
1607 	 * Fetch the APIC ID of the BSP in case we have a
1608 	 * default configuration (or the MP table is broken).
1609 	 */
1610 	new_apicid = read_apic_id();
1611 	if (boot_cpu_physical_apicid != new_apicid) {
1612 		boot_cpu_physical_apicid = new_apicid;
1613 		/*
1614 		 * yeah -- we lie about apic_version
1615 		 * in case if apic was disabled via boot option
1616 		 * but it's not a problem for SMP compiled kernel
1617 		 * since smp_sanity_check is prepared for such a case
1618 		 * and disable smp mode
1619 		 */
1620 		apic_version[new_apicid] =
1621 			 GET_APIC_VERSION(apic_read(APIC_LVR));
1622 	}
1623 }
1624 
1625 /*
1626  * This initializes the IO-APIC and APIC hardware if this is
1627  * a UP kernel.
1628  */
1629 int apic_version[MAX_APICS];
1630 
1631 int __init APIC_init_uniprocessor(void)
1632 {
1633 	if (disable_apic) {
1634 		pr_info("Apic disabled\n");
1635 		return -1;
1636 	}
1637 #ifdef CONFIG_X86_64
1638 	if (!cpu_has_apic) {
1639 		disable_apic = 1;
1640 		pr_info("Apic disabled by BIOS\n");
1641 		return -1;
1642 	}
1643 #else
1644 	if (!smp_found_config && !cpu_has_apic)
1645 		return -1;
1646 
1647 	/*
1648 	 * Complain if the BIOS pretends there is one.
1649 	 */
1650 	if (!cpu_has_apic &&
1651 	    APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
1652 		pr_err("BIOS bug, local APIC 0x%x not detected!...\n",
1653 			boot_cpu_physical_apicid);
1654 		clear_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1655 		return -1;
1656 	}
1657 #endif
1658 
1659 	enable_IR_x2apic();
1660 #ifdef CONFIG_X86_64
1661 	default_setup_apic_routing();
1662 #endif
1663 
1664 	verify_local_APIC();
1665 	connect_bsp_APIC();
1666 
1667 #ifdef CONFIG_X86_64
1668 	apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
1669 #else
1670 	/*
1671 	 * Hack: In case of kdump, after a crash, kernel might be booting
1672 	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
1673 	 * might be zero if read from MP tables. Get it from LAPIC.
1674 	 */
1675 # ifdef CONFIG_CRASH_DUMP
1676 	boot_cpu_physical_apicid = read_apic_id();
1677 # endif
1678 #endif
1679 	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
1680 	setup_local_APIC();
1681 
1682 #ifdef CONFIG_X86_IO_APIC
1683 	/*
1684 	 * Now enable IO-APICs, actually call clear_IO_APIC
1685 	 * We need clear_IO_APIC before enabling error vector
1686 	 */
1687 	if (!skip_ioapic_setup && nr_ioapics)
1688 		enable_IO_APIC();
1689 #endif
1690 
1691 	end_local_APIC_setup();
1692 
1693 #ifdef CONFIG_X86_IO_APIC
1694 	if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1695 		setup_IO_APIC();
1696 	else {
1697 		nr_ioapics = 0;
1698 		localise_nmi_watchdog();
1699 	}
1700 #else
1701 	localise_nmi_watchdog();
1702 #endif
1703 
1704 	setup_boot_clock();
1705 #ifdef CONFIG_X86_64
1706 	check_nmi_watchdog();
1707 #endif
1708 
1709 	return 0;
1710 }
1711 
1712 /*
1713  * Local APIC interrupts
1714  */
1715 
1716 /*
1717  * This interrupt should _never_ happen with our APIC/SMP architecture
1718  */
1719 void smp_spurious_interrupt(struct pt_regs *regs)
1720 {
1721 	u32 v;
1722 
1723 	exit_idle();
1724 	irq_enter();
1725 	/*
1726 	 * Check if this really is a spurious interrupt and ACK it
1727 	 * if it is a vectored one.  Just in case...
1728 	 * Spurious interrupts should not be ACKed.
1729 	 */
1730 	v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1731 	if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1732 		ack_APIC_irq();
1733 
1734 	inc_irq_stat(irq_spurious_count);
1735 
1736 	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
1737 	pr_info("spurious APIC interrupt on CPU#%d, "
1738 		"should never happen.\n", smp_processor_id());
1739 	irq_exit();
1740 }
1741 
1742 /*
1743  * This interrupt should never happen with our APIC/SMP architecture
1744  */
1745 void smp_error_interrupt(struct pt_regs *regs)
1746 {
1747 	u32 v, v1;
1748 
1749 	exit_idle();
1750 	irq_enter();
1751 	/* First tickle the hardware, only then report what went on. -- REW */
1752 	v = apic_read(APIC_ESR);
1753 	apic_write(APIC_ESR, 0);
1754 	v1 = apic_read(APIC_ESR);
1755 	ack_APIC_irq();
1756 	atomic_inc(&irq_err_count);
1757 
1758 	/*
1759 	 * Here is what the APIC error bits mean:
1760 	 * 0: Send CS error
1761 	 * 1: Receive CS error
1762 	 * 2: Send accept error
1763 	 * 3: Receive accept error
1764 	 * 4: Reserved
1765 	 * 5: Send illegal vector
1766 	 * 6: Received illegal vector
1767 	 * 7: Illegal register address
1768 	 */
1769 	pr_debug("APIC error on CPU%d: %02x(%02x)\n",
1770 		smp_processor_id(), v , v1);
1771 	irq_exit();
1772 }
1773 
1774 /**
1775  * connect_bsp_APIC - attach the APIC to the interrupt system
1776  */
1777 void __init connect_bsp_APIC(void)
1778 {
1779 #ifdef CONFIG_X86_32
1780 	if (pic_mode) {
1781 		/*
1782 		 * Do not trust the local APIC being empty at bootup.
1783 		 */
1784 		clear_local_APIC();
1785 		/*
1786 		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
1787 		 * local APIC to INT and NMI lines.
1788 		 */
1789 		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
1790 				"enabling APIC mode.\n");
1791 		imcr_pic_to_apic();
1792 	}
1793 #endif
1794 	if (apic->enable_apic_mode)
1795 		apic->enable_apic_mode();
1796 }
1797 
1798 /**
1799  * disconnect_bsp_APIC - detach the APIC from the interrupt system
1800  * @virt_wire_setup:	indicates, whether virtual wire mode is selected
1801  *
1802  * Virtual wire mode is necessary to deliver legacy interrupts even when the
1803  * APIC is disabled.
1804  */
1805 void disconnect_bsp_APIC(int virt_wire_setup)
1806 {
1807 	unsigned int value;
1808 
1809 #ifdef CONFIG_X86_32
1810 	if (pic_mode) {
1811 		/*
1812 		 * Put the board back into PIC mode (has an effect only on
1813 		 * certain older boards).  Note that APIC interrupts, including
1814 		 * IPIs, won't work beyond this point!  The only exception are
1815 		 * INIT IPIs.
1816 		 */
1817 		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
1818 				"entering PIC mode.\n");
1819 		imcr_apic_to_pic();
1820 		return;
1821 	}
1822 #endif
1823 
1824 	/* Go back to Virtual Wire compatibility mode */
1825 
1826 	/* For the spurious interrupt use vector F, and enable it */
1827 	value = apic_read(APIC_SPIV);
1828 	value &= ~APIC_VECTOR_MASK;
1829 	value |= APIC_SPIV_APIC_ENABLED;
1830 	value |= 0xf;
1831 	apic_write(APIC_SPIV, value);
1832 
1833 	if (!virt_wire_setup) {
1834 		/*
1835 		 * For LVT0 make it edge triggered, active high,
1836 		 * external and enabled
1837 		 */
1838 		value = apic_read(APIC_LVT0);
1839 		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1840 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1841 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1842 		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1843 		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1844 		apic_write(APIC_LVT0, value);
1845 	} else {
1846 		/* Disable LVT0 */
1847 		apic_write(APIC_LVT0, APIC_LVT_MASKED);
1848 	}
1849 
1850 	/*
1851 	 * For LVT1 make it edge triggered, active high,
1852 	 * nmi and enabled
1853 	 */
1854 	value = apic_read(APIC_LVT1);
1855 	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1856 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1857 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1858 	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1859 	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1860 	apic_write(APIC_LVT1, value);
1861 }
1862 
1863 void __cpuinit generic_processor_info(int apicid, int version)
1864 {
1865 	int cpu;
1866 
1867 	/*
1868 	 * Validate version
1869 	 */
1870 	if (version == 0x0) {
1871 		pr_warning("BIOS bug, APIC version is 0 for CPU#%d! "
1872 			   "fixing up to 0x10. (tell your hw vendor)\n",
1873 				version);
1874 		version = 0x10;
1875 	}
1876 	apic_version[apicid] = version;
1877 
1878 	if (num_processors >= nr_cpu_ids) {
1879 		int max = nr_cpu_ids;
1880 		int thiscpu = max + disabled_cpus;
1881 
1882 		pr_warning(
1883 			"ACPI: NR_CPUS/possible_cpus limit of %i reached."
1884 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
1885 
1886 		disabled_cpus++;
1887 		return;
1888 	}
1889 
1890 	num_processors++;
1891 	cpu = cpumask_next_zero(-1, cpu_present_mask);
1892 
1893 	if (version != apic_version[boot_cpu_physical_apicid])
1894 		WARN_ONCE(1,
1895 			"ACPI: apic version mismatch, bootcpu: %x cpu %d: %x\n",
1896 			apic_version[boot_cpu_physical_apicid], cpu, version);
1897 
1898 	physid_set(apicid, phys_cpu_present_map);
1899 	if (apicid == boot_cpu_physical_apicid) {
1900 		/*
1901 		 * x86_bios_cpu_apicid is required to have processors listed
1902 		 * in same order as logical cpu numbers. Hence the first
1903 		 * entry is BSP, and so on.
1904 		 */
1905 		cpu = 0;
1906 	}
1907 	if (apicid > max_physical_apicid)
1908 		max_physical_apicid = apicid;
1909 
1910 #ifdef CONFIG_X86_32
1911 	/*
1912 	 * Would be preferable to switch to bigsmp when CONFIG_HOTPLUG_CPU=y
1913 	 * but we need to work other dependencies like SMP_SUSPEND etc
1914 	 * before this can be done without some confusion.
1915 	 * if (CPU_HOTPLUG_ENABLED || num_processors > 8)
1916 	 *       - Ashok Raj <ashok.raj@intel.com>
1917 	 */
1918 	if (max_physical_apicid >= 8) {
1919 		switch (boot_cpu_data.x86_vendor) {
1920 		case X86_VENDOR_INTEL:
1921 			if (!APIC_XAPIC(version)) {
1922 				def_to_bigsmp = 0;
1923 				break;
1924 			}
1925 			/* If P4 and above fall through */
1926 		case X86_VENDOR_AMD:
1927 			def_to_bigsmp = 1;
1928 		}
1929 	}
1930 #endif
1931 
1932 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
1933 	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
1934 	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
1935 #endif
1936 
1937 	set_cpu_possible(cpu, true);
1938 	set_cpu_present(cpu, true);
1939 }
1940 
1941 int hard_smp_processor_id(void)
1942 {
1943 	return read_apic_id();
1944 }
1945 
1946 void default_init_apic_ldr(void)
1947 {
1948 	unsigned long val;
1949 
1950 	apic_write(APIC_DFR, APIC_DFR_VALUE);
1951 	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
1952 	val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
1953 	apic_write(APIC_LDR, val);
1954 }
1955 
1956 #ifdef CONFIG_X86_32
1957 int default_apicid_to_node(int logical_apicid)
1958 {
1959 #ifdef CONFIG_SMP
1960 	return apicid_2_node[hard_smp_processor_id()];
1961 #else
1962 	return 0;
1963 #endif
1964 }
1965 #endif
1966 
1967 /*
1968  * Power management
1969  */
1970 #ifdef CONFIG_PM
1971 
1972 static struct {
1973 	/*
1974 	 * 'active' is true if the local APIC was enabled by us and
1975 	 * not the BIOS; this signifies that we are also responsible
1976 	 * for disabling it before entering apm/acpi suspend
1977 	 */
1978 	int active;
1979 	/* r/w apic fields */
1980 	unsigned int apic_id;
1981 	unsigned int apic_taskpri;
1982 	unsigned int apic_ldr;
1983 	unsigned int apic_dfr;
1984 	unsigned int apic_spiv;
1985 	unsigned int apic_lvtt;
1986 	unsigned int apic_lvtpc;
1987 	unsigned int apic_lvt0;
1988 	unsigned int apic_lvt1;
1989 	unsigned int apic_lvterr;
1990 	unsigned int apic_tmict;
1991 	unsigned int apic_tdcr;
1992 	unsigned int apic_thmr;
1993 } apic_pm_state;
1994 
1995 static int lapic_suspend(struct sys_device *dev, pm_message_t state)
1996 {
1997 	unsigned long flags;
1998 	int maxlvt;
1999 
2000 	if (!apic_pm_state.active)
2001 		return 0;
2002 
2003 	maxlvt = lapic_get_maxlvt();
2004 
2005 	apic_pm_state.apic_id = apic_read(APIC_ID);
2006 	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2007 	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2008 	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2009 	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2010 	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2011 	if (maxlvt >= 4)
2012 		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2013 	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2014 	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2015 	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2016 	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2017 	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2018 #ifdef CONFIG_X86_THERMAL_VECTOR
2019 	if (maxlvt >= 5)
2020 		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2021 #endif
2022 
2023 	local_irq_save(flags);
2024 	disable_local_APIC();
2025 
2026 	if (intr_remapping_enabled)
2027 		disable_intr_remapping();
2028 
2029 	local_irq_restore(flags);
2030 	return 0;
2031 }
2032 
2033 static int lapic_resume(struct sys_device *dev)
2034 {
2035 	unsigned int l, h;
2036 	unsigned long flags;
2037 	int maxlvt;
2038 	int ret = 0;
2039 	struct IO_APIC_route_entry **ioapic_entries = NULL;
2040 
2041 	if (!apic_pm_state.active)
2042 		return 0;
2043 
2044 	local_irq_save(flags);
2045 	if (intr_remapping_enabled) {
2046 		ioapic_entries = alloc_ioapic_entries();
2047 		if (!ioapic_entries) {
2048 			WARN(1, "Alloc ioapic_entries in lapic resume failed.");
2049 			ret = -ENOMEM;
2050 			goto restore;
2051 		}
2052 
2053 		ret = save_IO_APIC_setup(ioapic_entries);
2054 		if (ret) {
2055 			WARN(1, "Saving IO-APIC state failed: %d\n", ret);
2056 			free_ioapic_entries(ioapic_entries);
2057 			goto restore;
2058 		}
2059 
2060 		mask_IO_APIC_setup(ioapic_entries);
2061 		mask_8259A();
2062 	}
2063 
2064 	if (x2apic_mode)
2065 		enable_x2apic();
2066 	else {
2067 		/*
2068 		 * Make sure the APICBASE points to the right address
2069 		 *
2070 		 * FIXME! This will be wrong if we ever support suspend on
2071 		 * SMP! We'll need to do this as part of the CPU restore!
2072 		 */
2073 		rdmsr(MSR_IA32_APICBASE, l, h);
2074 		l &= ~MSR_IA32_APICBASE_BASE;
2075 		l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2076 		wrmsr(MSR_IA32_APICBASE, l, h);
2077 	}
2078 
2079 	maxlvt = lapic_get_maxlvt();
2080 	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2081 	apic_write(APIC_ID, apic_pm_state.apic_id);
2082 	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2083 	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2084 	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2085 	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2086 	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2087 	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2088 #if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
2089 	if (maxlvt >= 5)
2090 		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2091 #endif
2092 	if (maxlvt >= 4)
2093 		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2094 	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2095 	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2096 	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2097 	apic_write(APIC_ESR, 0);
2098 	apic_read(APIC_ESR);
2099 	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2100 	apic_write(APIC_ESR, 0);
2101 	apic_read(APIC_ESR);
2102 
2103 	if (intr_remapping_enabled) {
2104 		reenable_intr_remapping(x2apic_mode);
2105 		unmask_8259A();
2106 		restore_IO_APIC_setup(ioapic_entries);
2107 		free_ioapic_entries(ioapic_entries);
2108 	}
2109 restore:
2110 	local_irq_restore(flags);
2111 
2112 	return ret;
2113 }
2114 
2115 /*
2116  * This device has no shutdown method - fully functioning local APICs
2117  * are needed on every CPU up until machine_halt/restart/poweroff.
2118  */
2119 
2120 static struct sysdev_class lapic_sysclass = {
2121 	.name		= "lapic",
2122 	.resume		= lapic_resume,
2123 	.suspend	= lapic_suspend,
2124 };
2125 
2126 static struct sys_device device_lapic = {
2127 	.id	= 0,
2128 	.cls	= &lapic_sysclass,
2129 };
2130 
2131 static void __cpuinit apic_pm_activate(void)
2132 {
2133 	apic_pm_state.active = 1;
2134 }
2135 
2136 static int __init init_lapic_sysfs(void)
2137 {
2138 	int error;
2139 
2140 	if (!cpu_has_apic)
2141 		return 0;
2142 	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2143 
2144 	error = sysdev_class_register(&lapic_sysclass);
2145 	if (!error)
2146 		error = sysdev_register(&device_lapic);
2147 	return error;
2148 }
2149 
2150 /* local apic needs to resume before other devices access its registers. */
2151 core_initcall(init_lapic_sysfs);
2152 
2153 #else	/* CONFIG_PM */
2154 
2155 static void apic_pm_activate(void) { }
2156 
2157 #endif	/* CONFIG_PM */
2158 
2159 #ifdef CONFIG_X86_64
2160 
2161 static int __cpuinit apic_cluster_num(void)
2162 {
2163 	int i, clusters, zeros;
2164 	unsigned id;
2165 	u16 *bios_cpu_apicid;
2166 	DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
2167 
2168 	bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
2169 	bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
2170 
2171 	for (i = 0; i < nr_cpu_ids; i++) {
2172 		/* are we being called early in kernel startup? */
2173 		if (bios_cpu_apicid) {
2174 			id = bios_cpu_apicid[i];
2175 		} else if (i < nr_cpu_ids) {
2176 			if (cpu_present(i))
2177 				id = per_cpu(x86_bios_cpu_apicid, i);
2178 			else
2179 				continue;
2180 		} else
2181 			break;
2182 
2183 		if (id != BAD_APICID)
2184 			__set_bit(APIC_CLUSTERID(id), clustermap);
2185 	}
2186 
2187 	/* Problem:  Partially populated chassis may not have CPUs in some of
2188 	 * the APIC clusters they have been allocated.  Only present CPUs have
2189 	 * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap.
2190 	 * Since clusters are allocated sequentially, count zeros only if
2191 	 * they are bounded by ones.
2192 	 */
2193 	clusters = 0;
2194 	zeros = 0;
2195 	for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
2196 		if (test_bit(i, clustermap)) {
2197 			clusters += 1 + zeros;
2198 			zeros = 0;
2199 		} else
2200 			++zeros;
2201 	}
2202 
2203 	return clusters;
2204 }
2205 
2206 static int __cpuinitdata multi_checked;
2207 static int __cpuinitdata multi;
2208 
2209 static int __cpuinit set_multi(const struct dmi_system_id *d)
2210 {
2211 	if (multi)
2212 		return 0;
2213 	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2214 	multi = 1;
2215 	return 0;
2216 }
2217 
2218 static const __cpuinitconst struct dmi_system_id multi_dmi_table[] = {
2219 	{
2220 		.callback = set_multi,
2221 		.ident = "IBM System Summit2",
2222 		.matches = {
2223 			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2224 			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2225 		},
2226 	},
2227 	{}
2228 };
2229 
2230 static void __cpuinit dmi_check_multi(void)
2231 {
2232 	if (multi_checked)
2233 		return;
2234 
2235 	dmi_check_system(multi_dmi_table);
2236 	multi_checked = 1;
2237 }
2238 
2239 /*
2240  * apic_is_clustered_box() -- Check if we can expect good TSC
2241  *
2242  * Thus far, the major user of this is IBM's Summit2 series:
2243  * Clustered boxes may have unsynced TSC problems if they are
2244  * multi-chassis.
2245  * Use DMI to check them
2246  */
2247 __cpuinit int apic_is_clustered_box(void)
2248 {
2249 	dmi_check_multi();
2250 	if (multi)
2251 		return 1;
2252 
2253 	if (!is_vsmp_box())
2254 		return 0;
2255 
2256 	/*
2257 	 * ScaleMP vSMPowered boxes have one cluster per board and TSCs are
2258 	 * not guaranteed to be synced between boards
2259 	 */
2260 	if (apic_cluster_num() > 1)
2261 		return 1;
2262 
2263 	return 0;
2264 }
2265 #endif
2266 
2267 /*
2268  * APIC command line parameters
2269  */
2270 static int __init setup_disableapic(char *arg)
2271 {
2272 	disable_apic = 1;
2273 	setup_clear_cpu_cap(X86_FEATURE_APIC);
2274 	return 0;
2275 }
2276 early_param("disableapic", setup_disableapic);
2277 
2278 /* same as disableapic, for compatibility */
2279 static int __init setup_nolapic(char *arg)
2280 {
2281 	return setup_disableapic(arg);
2282 }
2283 early_param("nolapic", setup_nolapic);
2284 
2285 static int __init parse_lapic_timer_c2_ok(char *arg)
2286 {
2287 	local_apic_timer_c2_ok = 1;
2288 	return 0;
2289 }
2290 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2291 
2292 static int __init parse_disable_apic_timer(char *arg)
2293 {
2294 	disable_apic_timer = 1;
2295 	return 0;
2296 }
2297 early_param("noapictimer", parse_disable_apic_timer);
2298 
2299 static int __init parse_nolapic_timer(char *arg)
2300 {
2301 	disable_apic_timer = 1;
2302 	return 0;
2303 }
2304 early_param("nolapic_timer", parse_nolapic_timer);
2305 
2306 static int __init apic_set_verbosity(char *arg)
2307 {
2308 	if (!arg)  {
2309 #ifdef CONFIG_X86_64
2310 		skip_ioapic_setup = 0;
2311 		return 0;
2312 #endif
2313 		return -EINVAL;
2314 	}
2315 
2316 	if (strcmp("debug", arg) == 0)
2317 		apic_verbosity = APIC_DEBUG;
2318 	else if (strcmp("verbose", arg) == 0)
2319 		apic_verbosity = APIC_VERBOSE;
2320 	else {
2321 		pr_warning("APIC Verbosity level %s not recognised"
2322 			" use apic=verbose or apic=debug\n", arg);
2323 		return -EINVAL;
2324 	}
2325 
2326 	return 0;
2327 }
2328 early_param("apic", apic_set_verbosity);
2329 
2330 static int __init lapic_insert_resource(void)
2331 {
2332 	if (!apic_phys)
2333 		return -1;
2334 
2335 	/* Put local APIC into the resource map. */
2336 	lapic_resource.start = apic_phys;
2337 	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2338 	insert_resource(&iomem_resource, &lapic_resource);
2339 
2340 	return 0;
2341 }
2342 
2343 /*
2344  * need call insert after e820_reserve_resources()
2345  * that is using request_resource
2346  */
2347 late_initcall(lapic_insert_resource);
2348