xref: /openbmc/linux/arch/x86/kernel/apic/apic.c (revision a09d2831)
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/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_event.h>
39 #include <asm/x86_init.h>
40 #include <asm/pgalloc.h>
41 #include <asm/atomic.h>
42 #include <asm/mpspec.h>
43 #include <asm/i8253.h>
44 #include <asm/i8259.h>
45 #include <asm/proto.h>
46 #include <asm/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/kvm_para.h>
54 
55 unsigned int num_processors;
56 
57 unsigned disabled_cpus __cpuinitdata;
58 
59 /* Processor that is doing the boot up */
60 unsigned int boot_cpu_physical_apicid = -1U;
61 
62 /*
63  * The highest APIC ID seen during enumeration.
64  *
65  * This determines the messaging protocol we can use: if all APIC IDs
66  * are in the 0 ... 7 range, then we can use logical addressing which
67  * has some performance advantages (better broadcasting).
68  *
69  * If there's an APIC ID above 8, we use physical addressing.
70  */
71 unsigned int max_physical_apicid;
72 
73 /*
74  * Bitmask of physically existing CPUs:
75  */
76 physid_mask_t phys_cpu_present_map;
77 
78 /*
79  * Map cpu index to physical APIC ID
80  */
81 DEFINE_EARLY_PER_CPU(u16, x86_cpu_to_apicid, BAD_APICID);
82 DEFINE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid, BAD_APICID);
83 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
84 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
85 
86 #ifdef CONFIG_X86_32
87 /*
88  * Knob to control our willingness to enable the local APIC.
89  *
90  * +1=force-enable
91  */
92 static int force_enable_local_apic;
93 /*
94  * APIC command line parameters
95  */
96 static int __init parse_lapic(char *arg)
97 {
98 	force_enable_local_apic = 1;
99 	return 0;
100 }
101 early_param("lapic", parse_lapic);
102 /* Local APIC was disabled by the BIOS and enabled by the kernel */
103 static int enabled_via_apicbase;
104 
105 /*
106  * Handle interrupt mode configuration register (IMCR).
107  * This register controls whether the interrupt signals
108  * that reach the BSP come from the master PIC or from the
109  * local APIC. Before entering Symmetric I/O Mode, either
110  * the BIOS or the operating system must switch out of
111  * PIC Mode by changing the IMCR.
112  */
113 static inline void imcr_pic_to_apic(void)
114 {
115 	/* select IMCR register */
116 	outb(0x70, 0x22);
117 	/* NMI and 8259 INTR go through APIC */
118 	outb(0x01, 0x23);
119 }
120 
121 static inline void imcr_apic_to_pic(void)
122 {
123 	/* select IMCR register */
124 	outb(0x70, 0x22);
125 	/* NMI and 8259 INTR go directly to BSP */
126 	outb(0x00, 0x23);
127 }
128 #endif
129 
130 #ifdef CONFIG_X86_64
131 static int apic_calibrate_pmtmr __initdata;
132 static __init int setup_apicpmtimer(char *s)
133 {
134 	apic_calibrate_pmtmr = 1;
135 	notsc_setup(NULL);
136 	return 0;
137 }
138 __setup("apicpmtimer", setup_apicpmtimer);
139 #endif
140 
141 int x2apic_mode;
142 #ifdef CONFIG_X86_X2APIC
143 /* x2apic enabled before OS handover */
144 static int x2apic_preenabled;
145 static __init int setup_nox2apic(char *str)
146 {
147 	if (x2apic_enabled()) {
148 		pr_warning("Bios already enabled x2apic, "
149 			   "can't enforce nox2apic");
150 		return 0;
151 	}
152 
153 	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
154 	return 0;
155 }
156 early_param("nox2apic", setup_nox2apic);
157 #endif
158 
159 unsigned long mp_lapic_addr;
160 int disable_apic;
161 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
162 static int disable_apic_timer __cpuinitdata;
163 /* Local APIC timer works in C2 */
164 int local_apic_timer_c2_ok;
165 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
166 
167 int first_system_vector = 0xfe;
168 
169 /*
170  * Debug level, exported for io_apic.c
171  */
172 unsigned int apic_verbosity;
173 
174 int pic_mode;
175 
176 /* Have we found an MP table */
177 int smp_found_config;
178 
179 static struct resource lapic_resource = {
180 	.name = "Local APIC",
181 	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
182 };
183 
184 static unsigned int calibration_result;
185 
186 static int lapic_next_event(unsigned long delta,
187 			    struct clock_event_device *evt);
188 static void lapic_timer_setup(enum clock_event_mode mode,
189 			      struct clock_event_device *evt);
190 static void lapic_timer_broadcast(const struct cpumask *mask);
191 static void apic_pm_activate(void);
192 
193 /*
194  * The local apic timer can be used for any function which is CPU local.
195  */
196 static struct clock_event_device lapic_clockevent = {
197 	.name		= "lapic",
198 	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
199 			| CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
200 	.shift		= 32,
201 	.set_mode	= lapic_timer_setup,
202 	.set_next_event	= lapic_next_event,
203 	.broadcast	= lapic_timer_broadcast,
204 	.rating		= 100,
205 	.irq		= -1,
206 };
207 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
208 
209 static unsigned long apic_phys;
210 
211 /*
212  * Get the LAPIC version
213  */
214 static inline int lapic_get_version(void)
215 {
216 	return GET_APIC_VERSION(apic_read(APIC_LVR));
217 }
218 
219 /*
220  * Check, if the APIC is integrated or a separate chip
221  */
222 static inline int lapic_is_integrated(void)
223 {
224 #ifdef CONFIG_X86_64
225 	return 1;
226 #else
227 	return APIC_INTEGRATED(lapic_get_version());
228 #endif
229 }
230 
231 /*
232  * Check, whether this is a modern or a first generation APIC
233  */
234 static int modern_apic(void)
235 {
236 	/* AMD systems use old APIC versions, so check the CPU */
237 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
238 	    boot_cpu_data.x86 >= 0xf)
239 		return 1;
240 	return lapic_get_version() >= 0x14;
241 }
242 
243 /*
244  * right after this call apic become NOOP driven
245  * so apic->write/read doesn't do anything
246  */
247 void apic_disable(void)
248 {
249 	pr_info("APIC: switched to apic NOOP\n");
250 	apic = &apic_noop;
251 }
252 
253 void native_apic_wait_icr_idle(void)
254 {
255 	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
256 		cpu_relax();
257 }
258 
259 u32 native_safe_apic_wait_icr_idle(void)
260 {
261 	u32 send_status;
262 	int timeout;
263 
264 	timeout = 0;
265 	do {
266 		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
267 		if (!send_status)
268 			break;
269 		udelay(100);
270 	} while (timeout++ < 1000);
271 
272 	return send_status;
273 }
274 
275 void native_apic_icr_write(u32 low, u32 id)
276 {
277 	apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
278 	apic_write(APIC_ICR, low);
279 }
280 
281 u64 native_apic_icr_read(void)
282 {
283 	u32 icr1, icr2;
284 
285 	icr2 = apic_read(APIC_ICR2);
286 	icr1 = apic_read(APIC_ICR);
287 
288 	return icr1 | ((u64)icr2 << 32);
289 }
290 
291 /**
292  * enable_NMI_through_LVT0 - enable NMI through local vector table 0
293  */
294 void __cpuinit enable_NMI_through_LVT0(void)
295 {
296 	unsigned int v;
297 
298 	/* unmask and set to NMI */
299 	v = APIC_DM_NMI;
300 
301 	/* Level triggered for 82489DX (32bit mode) */
302 	if (!lapic_is_integrated())
303 		v |= APIC_LVT_LEVEL_TRIGGER;
304 
305 	apic_write(APIC_LVT0, v);
306 }
307 
308 #ifdef CONFIG_X86_32
309 /**
310  * get_physical_broadcast - Get number of physical broadcast IDs
311  */
312 int get_physical_broadcast(void)
313 {
314 	return modern_apic() ? 0xff : 0xf;
315 }
316 #endif
317 
318 /**
319  * lapic_get_maxlvt - get the maximum number of local vector table entries
320  */
321 int lapic_get_maxlvt(void)
322 {
323 	unsigned int v;
324 
325 	v = apic_read(APIC_LVR);
326 	/*
327 	 * - we always have APIC integrated on 64bit mode
328 	 * - 82489DXs do not report # of LVT entries
329 	 */
330 	return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
331 }
332 
333 /*
334  * Local APIC timer
335  */
336 
337 /* Clock divisor */
338 #define APIC_DIVISOR 16
339 
340 /*
341  * This function sets up the local APIC timer, with a timeout of
342  * 'clocks' APIC bus clock. During calibration we actually call
343  * this function twice on the boot CPU, once with a bogus timeout
344  * value, second time for real. The other (noncalibrating) CPUs
345  * call this function only once, with the real, calibrated value.
346  *
347  * We do reads before writes even if unnecessary, to get around the
348  * P5 APIC double write bug.
349  */
350 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
351 {
352 	unsigned int lvtt_value, tmp_value;
353 
354 	lvtt_value = LOCAL_TIMER_VECTOR;
355 	if (!oneshot)
356 		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
357 	if (!lapic_is_integrated())
358 		lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
359 
360 	if (!irqen)
361 		lvtt_value |= APIC_LVT_MASKED;
362 
363 	apic_write(APIC_LVTT, lvtt_value);
364 
365 	/*
366 	 * Divide PICLK by 16
367 	 */
368 	tmp_value = apic_read(APIC_TDCR);
369 	apic_write(APIC_TDCR,
370 		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
371 		APIC_TDR_DIV_16);
372 
373 	if (!oneshot)
374 		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
375 }
376 
377 /*
378  * Setup extended LVT, AMD specific (K8, family 10h)
379  *
380  * Vector mappings are hard coded. On K8 only offset 0 (APIC500) and
381  * MCE interrupts are supported. Thus MCE offset must be set to 0.
382  *
383  * If mask=1, the LVT entry does not generate interrupts while mask=0
384  * enables the vector. See also the BKDGs.
385  */
386 
387 #define APIC_EILVT_LVTOFF_MCE 0
388 #define APIC_EILVT_LVTOFF_IBS 1
389 
390 static void setup_APIC_eilvt(u8 lvt_off, u8 vector, u8 msg_type, u8 mask)
391 {
392 	unsigned long reg = (lvt_off << 4) + APIC_EILVTn(0);
393 	unsigned int  v   = (mask << 16) | (msg_type << 8) | vector;
394 
395 	apic_write(reg, v);
396 }
397 
398 u8 setup_APIC_eilvt_mce(u8 vector, u8 msg_type, u8 mask)
399 {
400 	setup_APIC_eilvt(APIC_EILVT_LVTOFF_MCE, vector, msg_type, mask);
401 	return APIC_EILVT_LVTOFF_MCE;
402 }
403 
404 u8 setup_APIC_eilvt_ibs(u8 vector, u8 msg_type, u8 mask)
405 {
406 	setup_APIC_eilvt(APIC_EILVT_LVTOFF_IBS, vector, msg_type, mask);
407 	return APIC_EILVT_LVTOFF_IBS;
408 }
409 EXPORT_SYMBOL_GPL(setup_APIC_eilvt_ibs);
410 
411 /*
412  * Program the next event, relative to now
413  */
414 static int lapic_next_event(unsigned long delta,
415 			    struct clock_event_device *evt)
416 {
417 	apic_write(APIC_TMICT, delta);
418 	return 0;
419 }
420 
421 /*
422  * Setup the lapic timer in periodic or oneshot mode
423  */
424 static void lapic_timer_setup(enum clock_event_mode mode,
425 			      struct clock_event_device *evt)
426 {
427 	unsigned long flags;
428 	unsigned int v;
429 
430 	/* Lapic used as dummy for broadcast ? */
431 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
432 		return;
433 
434 	local_irq_save(flags);
435 
436 	switch (mode) {
437 	case CLOCK_EVT_MODE_PERIODIC:
438 	case CLOCK_EVT_MODE_ONESHOT:
439 		__setup_APIC_LVTT(calibration_result,
440 				  mode != CLOCK_EVT_MODE_PERIODIC, 1);
441 		break;
442 	case CLOCK_EVT_MODE_UNUSED:
443 	case CLOCK_EVT_MODE_SHUTDOWN:
444 		v = apic_read(APIC_LVTT);
445 		v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
446 		apic_write(APIC_LVTT, v);
447 		apic_write(APIC_TMICT, 0);
448 		break;
449 	case CLOCK_EVT_MODE_RESUME:
450 		/* Nothing to do here */
451 		break;
452 	}
453 
454 	local_irq_restore(flags);
455 }
456 
457 /*
458  * Local APIC timer broadcast function
459  */
460 static void lapic_timer_broadcast(const struct cpumask *mask)
461 {
462 #ifdef CONFIG_SMP
463 	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
464 #endif
465 }
466 
467 /*
468  * Setup the local APIC timer for this CPU. Copy the initilized values
469  * of the boot CPU and register the clock event in the framework.
470  */
471 static void __cpuinit setup_APIC_timer(void)
472 {
473 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
474 
475 	if (cpu_has(&current_cpu_data, X86_FEATURE_ARAT)) {
476 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
477 		/* Make LAPIC timer preferrable over percpu HPET */
478 		lapic_clockevent.rating = 150;
479 	}
480 
481 	memcpy(levt, &lapic_clockevent, sizeof(*levt));
482 	levt->cpumask = cpumask_of(smp_processor_id());
483 
484 	clockevents_register_device(levt);
485 }
486 
487 /*
488  * In this functions we calibrate APIC bus clocks to the external timer.
489  *
490  * We want to do the calibration only once since we want to have local timer
491  * irqs syncron. CPUs connected by the same APIC bus have the very same bus
492  * frequency.
493  *
494  * This was previously done by reading the PIT/HPET and waiting for a wrap
495  * around to find out, that a tick has elapsed. I have a box, where the PIT
496  * readout is broken, so it never gets out of the wait loop again. This was
497  * also reported by others.
498  *
499  * Monitoring the jiffies value is inaccurate and the clockevents
500  * infrastructure allows us to do a simple substitution of the interrupt
501  * handler.
502  *
503  * The calibration routine also uses the pm_timer when possible, as the PIT
504  * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
505  * back to normal later in the boot process).
506  */
507 
508 #define LAPIC_CAL_LOOPS		(HZ/10)
509 
510 static __initdata int lapic_cal_loops = -1;
511 static __initdata long lapic_cal_t1, lapic_cal_t2;
512 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
513 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
514 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
515 
516 /*
517  * Temporary interrupt handler.
518  */
519 static void __init lapic_cal_handler(struct clock_event_device *dev)
520 {
521 	unsigned long long tsc = 0;
522 	long tapic = apic_read(APIC_TMCCT);
523 	unsigned long pm = acpi_pm_read_early();
524 
525 	if (cpu_has_tsc)
526 		rdtscll(tsc);
527 
528 	switch (lapic_cal_loops++) {
529 	case 0:
530 		lapic_cal_t1 = tapic;
531 		lapic_cal_tsc1 = tsc;
532 		lapic_cal_pm1 = pm;
533 		lapic_cal_j1 = jiffies;
534 		break;
535 
536 	case LAPIC_CAL_LOOPS:
537 		lapic_cal_t2 = tapic;
538 		lapic_cal_tsc2 = tsc;
539 		if (pm < lapic_cal_pm1)
540 			pm += ACPI_PM_OVRRUN;
541 		lapic_cal_pm2 = pm;
542 		lapic_cal_j2 = jiffies;
543 		break;
544 	}
545 }
546 
547 static int __init
548 calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
549 {
550 	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
551 	const long pm_thresh = pm_100ms / 100;
552 	unsigned long mult;
553 	u64 res;
554 
555 #ifndef CONFIG_X86_PM_TIMER
556 	return -1;
557 #endif
558 
559 	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
560 
561 	/* Check, if the PM timer is available */
562 	if (!deltapm)
563 		return -1;
564 
565 	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
566 
567 	if (deltapm > (pm_100ms - pm_thresh) &&
568 	    deltapm < (pm_100ms + pm_thresh)) {
569 		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
570 		return 0;
571 	}
572 
573 	res = (((u64)deltapm) *  mult) >> 22;
574 	do_div(res, 1000000);
575 	pr_warning("APIC calibration not consistent "
576 		   "with PM-Timer: %ldms instead of 100ms\n",(long)res);
577 
578 	/* Correct the lapic counter value */
579 	res = (((u64)(*delta)) * pm_100ms);
580 	do_div(res, deltapm);
581 	pr_info("APIC delta adjusted to PM-Timer: "
582 		"%lu (%ld)\n", (unsigned long)res, *delta);
583 	*delta = (long)res;
584 
585 	/* Correct the tsc counter value */
586 	if (cpu_has_tsc) {
587 		res = (((u64)(*deltatsc)) * pm_100ms);
588 		do_div(res, deltapm);
589 		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
590 					  "PM-Timer: %lu (%ld) \n",
591 					(unsigned long)res, *deltatsc);
592 		*deltatsc = (long)res;
593 	}
594 
595 	return 0;
596 }
597 
598 static int __init calibrate_APIC_clock(void)
599 {
600 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
601 	void (*real_handler)(struct clock_event_device *dev);
602 	unsigned long deltaj;
603 	long delta, deltatsc;
604 	int pm_referenced = 0;
605 
606 	local_irq_disable();
607 
608 	/* Replace the global interrupt handler */
609 	real_handler = global_clock_event->event_handler;
610 	global_clock_event->event_handler = lapic_cal_handler;
611 
612 	/*
613 	 * Setup the APIC counter to maximum. There is no way the lapic
614 	 * can underflow in the 100ms detection time frame
615 	 */
616 	__setup_APIC_LVTT(0xffffffff, 0, 0);
617 
618 	/* Let the interrupts run */
619 	local_irq_enable();
620 
621 	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
622 		cpu_relax();
623 
624 	local_irq_disable();
625 
626 	/* Restore the real event handler */
627 	global_clock_event->event_handler = real_handler;
628 
629 	/* Build delta t1-t2 as apic timer counts down */
630 	delta = lapic_cal_t1 - lapic_cal_t2;
631 	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
632 
633 	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
634 
635 	/* we trust the PM based calibration if possible */
636 	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
637 					&delta, &deltatsc);
638 
639 	/* Calculate the scaled math multiplication factor */
640 	lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
641 				       lapic_clockevent.shift);
642 	lapic_clockevent.max_delta_ns =
643 		clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
644 	lapic_clockevent.min_delta_ns =
645 		clockevent_delta2ns(0xF, &lapic_clockevent);
646 
647 	calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
648 
649 	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
650 	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
651 	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
652 		    calibration_result);
653 
654 	if (cpu_has_tsc) {
655 		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
656 			    "%ld.%04ld MHz.\n",
657 			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
658 			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
659 	}
660 
661 	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
662 		    "%u.%04u MHz.\n",
663 		    calibration_result / (1000000 / HZ),
664 		    calibration_result % (1000000 / HZ));
665 
666 	/*
667 	 * Do a sanity check on the APIC calibration result
668 	 */
669 	if (calibration_result < (1000000 / HZ)) {
670 		local_irq_enable();
671 		pr_warning("APIC frequency too slow, disabling apic timer\n");
672 		return -1;
673 	}
674 
675 	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
676 
677 	/*
678 	 * PM timer calibration failed or not turned on
679 	 * so lets try APIC timer based calibration
680 	 */
681 	if (!pm_referenced) {
682 		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
683 
684 		/*
685 		 * Setup the apic timer manually
686 		 */
687 		levt->event_handler = lapic_cal_handler;
688 		lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
689 		lapic_cal_loops = -1;
690 
691 		/* Let the interrupts run */
692 		local_irq_enable();
693 
694 		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
695 			cpu_relax();
696 
697 		/* Stop the lapic timer */
698 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
699 
700 		/* Jiffies delta */
701 		deltaj = lapic_cal_j2 - lapic_cal_j1;
702 		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
703 
704 		/* Check, if the jiffies result is consistent */
705 		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
706 			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
707 		else
708 			levt->features |= CLOCK_EVT_FEAT_DUMMY;
709 	} else
710 		local_irq_enable();
711 
712 	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
713 		pr_warning("APIC timer disabled due to verification failure\n");
714 			return -1;
715 	}
716 
717 	return 0;
718 }
719 
720 /*
721  * Setup the boot APIC
722  *
723  * Calibrate and verify the result.
724  */
725 void __init setup_boot_APIC_clock(void)
726 {
727 	/*
728 	 * The local apic timer can be disabled via the kernel
729 	 * commandline or from the CPU detection code. Register the lapic
730 	 * timer as a dummy clock event source on SMP systems, so the
731 	 * broadcast mechanism is used. On UP systems simply ignore it.
732 	 */
733 	if (disable_apic_timer) {
734 		pr_info("Disabling APIC timer\n");
735 		/* No broadcast on UP ! */
736 		if (num_possible_cpus() > 1) {
737 			lapic_clockevent.mult = 1;
738 			setup_APIC_timer();
739 		}
740 		return;
741 	}
742 
743 	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
744 		    "calibrating APIC timer ...\n");
745 
746 	if (calibrate_APIC_clock()) {
747 		/* No broadcast on UP ! */
748 		if (num_possible_cpus() > 1)
749 			setup_APIC_timer();
750 		return;
751 	}
752 
753 	/*
754 	 * If nmi_watchdog is set to IO_APIC, we need the
755 	 * PIT/HPET going.  Otherwise register lapic as a dummy
756 	 * device.
757 	 */
758 	if (nmi_watchdog != NMI_IO_APIC)
759 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
760 	else
761 		pr_warning("APIC timer registered as dummy,"
762 			" due to nmi_watchdog=%d!\n", nmi_watchdog);
763 
764 	/* Setup the lapic or request the broadcast */
765 	setup_APIC_timer();
766 }
767 
768 void __cpuinit setup_secondary_APIC_clock(void)
769 {
770 	setup_APIC_timer();
771 }
772 
773 /*
774  * The guts of the apic timer interrupt
775  */
776 static void local_apic_timer_interrupt(void)
777 {
778 	int cpu = smp_processor_id();
779 	struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
780 
781 	/*
782 	 * Normally we should not be here till LAPIC has been initialized but
783 	 * in some cases like kdump, its possible that there is a pending LAPIC
784 	 * timer interrupt from previous kernel's context and is delivered in
785 	 * new kernel the moment interrupts are enabled.
786 	 *
787 	 * Interrupts are enabled early and LAPIC is setup much later, hence
788 	 * its possible that when we get here evt->event_handler is NULL.
789 	 * Check for event_handler being NULL and discard the interrupt as
790 	 * spurious.
791 	 */
792 	if (!evt->event_handler) {
793 		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu);
794 		/* Switch it off */
795 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
796 		return;
797 	}
798 
799 	/*
800 	 * the NMI deadlock-detector uses this.
801 	 */
802 	inc_irq_stat(apic_timer_irqs);
803 
804 	evt->event_handler(evt);
805 }
806 
807 /*
808  * Local APIC timer interrupt. This is the most natural way for doing
809  * local interrupts, but local timer interrupts can be emulated by
810  * broadcast interrupts too. [in case the hw doesn't support APIC timers]
811  *
812  * [ if a single-CPU system runs an SMP kernel then we call the local
813  *   interrupt as well. Thus we cannot inline the local irq ... ]
814  */
815 void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
816 {
817 	struct pt_regs *old_regs = set_irq_regs(regs);
818 
819 	/*
820 	 * NOTE! We'd better ACK the irq immediately,
821 	 * because timer handling can be slow.
822 	 */
823 	ack_APIC_irq();
824 	/*
825 	 * update_process_times() expects us to have done irq_enter().
826 	 * Besides, if we don't timer interrupts ignore the global
827 	 * interrupt lock, which is the WrongThing (tm) to do.
828 	 */
829 	exit_idle();
830 	irq_enter();
831 	local_apic_timer_interrupt();
832 	irq_exit();
833 
834 	set_irq_regs(old_regs);
835 }
836 
837 int setup_profiling_timer(unsigned int multiplier)
838 {
839 	return -EINVAL;
840 }
841 
842 /*
843  * Local APIC start and shutdown
844  */
845 
846 /**
847  * clear_local_APIC - shutdown the local APIC
848  *
849  * This is called, when a CPU is disabled and before rebooting, so the state of
850  * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
851  * leftovers during boot.
852  */
853 void clear_local_APIC(void)
854 {
855 	int maxlvt;
856 	u32 v;
857 
858 	/* APIC hasn't been mapped yet */
859 	if (!x2apic_mode && !apic_phys)
860 		return;
861 
862 	maxlvt = lapic_get_maxlvt();
863 	/*
864 	 * Masking an LVT entry can trigger a local APIC error
865 	 * if the vector is zero. Mask LVTERR first to prevent this.
866 	 */
867 	if (maxlvt >= 3) {
868 		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
869 		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
870 	}
871 	/*
872 	 * Careful: we have to set masks only first to deassert
873 	 * any level-triggered sources.
874 	 */
875 	v = apic_read(APIC_LVTT);
876 	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
877 	v = apic_read(APIC_LVT0);
878 	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
879 	v = apic_read(APIC_LVT1);
880 	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
881 	if (maxlvt >= 4) {
882 		v = apic_read(APIC_LVTPC);
883 		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
884 	}
885 
886 	/* lets not touch this if we didn't frob it */
887 #ifdef CONFIG_X86_THERMAL_VECTOR
888 	if (maxlvt >= 5) {
889 		v = apic_read(APIC_LVTTHMR);
890 		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
891 	}
892 #endif
893 #ifdef CONFIG_X86_MCE_INTEL
894 	if (maxlvt >= 6) {
895 		v = apic_read(APIC_LVTCMCI);
896 		if (!(v & APIC_LVT_MASKED))
897 			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
898 	}
899 #endif
900 
901 	/*
902 	 * Clean APIC state for other OSs:
903 	 */
904 	apic_write(APIC_LVTT, APIC_LVT_MASKED);
905 	apic_write(APIC_LVT0, APIC_LVT_MASKED);
906 	apic_write(APIC_LVT1, APIC_LVT_MASKED);
907 	if (maxlvt >= 3)
908 		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
909 	if (maxlvt >= 4)
910 		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
911 
912 	/* Integrated APIC (!82489DX) ? */
913 	if (lapic_is_integrated()) {
914 		if (maxlvt > 3)
915 			/* Clear ESR due to Pentium errata 3AP and 11AP */
916 			apic_write(APIC_ESR, 0);
917 		apic_read(APIC_ESR);
918 	}
919 }
920 
921 /**
922  * disable_local_APIC - clear and disable the local APIC
923  */
924 void disable_local_APIC(void)
925 {
926 	unsigned int value;
927 
928 	/* APIC hasn't been mapped yet */
929 	if (!apic_phys)
930 		return;
931 
932 	clear_local_APIC();
933 
934 	/*
935 	 * Disable APIC (implies clearing of registers
936 	 * for 82489DX!).
937 	 */
938 	value = apic_read(APIC_SPIV);
939 	value &= ~APIC_SPIV_APIC_ENABLED;
940 	apic_write(APIC_SPIV, value);
941 
942 #ifdef CONFIG_X86_32
943 	/*
944 	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
945 	 * restore the disabled state.
946 	 */
947 	if (enabled_via_apicbase) {
948 		unsigned int l, h;
949 
950 		rdmsr(MSR_IA32_APICBASE, l, h);
951 		l &= ~MSR_IA32_APICBASE_ENABLE;
952 		wrmsr(MSR_IA32_APICBASE, l, h);
953 	}
954 #endif
955 }
956 
957 /*
958  * If Linux enabled the LAPIC against the BIOS default disable it down before
959  * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
960  * not power-off.  Additionally clear all LVT entries before disable_local_APIC
961  * for the case where Linux didn't enable the LAPIC.
962  */
963 void lapic_shutdown(void)
964 {
965 	unsigned long flags;
966 
967 	if (!cpu_has_apic && !apic_from_smp_config())
968 		return;
969 
970 	local_irq_save(flags);
971 
972 #ifdef CONFIG_X86_32
973 	if (!enabled_via_apicbase)
974 		clear_local_APIC();
975 	else
976 #endif
977 		disable_local_APIC();
978 
979 
980 	local_irq_restore(flags);
981 }
982 
983 /*
984  * This is to verify that we're looking at a real local APIC.
985  * Check these against your board if the CPUs aren't getting
986  * started for no apparent reason.
987  */
988 int __init verify_local_APIC(void)
989 {
990 	unsigned int reg0, reg1;
991 
992 	/*
993 	 * The version register is read-only in a real APIC.
994 	 */
995 	reg0 = apic_read(APIC_LVR);
996 	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
997 	apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
998 	reg1 = apic_read(APIC_LVR);
999 	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
1000 
1001 	/*
1002 	 * The two version reads above should print the same
1003 	 * numbers.  If the second one is different, then we
1004 	 * poke at a non-APIC.
1005 	 */
1006 	if (reg1 != reg0)
1007 		return 0;
1008 
1009 	/*
1010 	 * Check if the version looks reasonably.
1011 	 */
1012 	reg1 = GET_APIC_VERSION(reg0);
1013 	if (reg1 == 0x00 || reg1 == 0xff)
1014 		return 0;
1015 	reg1 = lapic_get_maxlvt();
1016 	if (reg1 < 0x02 || reg1 == 0xff)
1017 		return 0;
1018 
1019 	/*
1020 	 * The ID register is read/write in a real APIC.
1021 	 */
1022 	reg0 = apic_read(APIC_ID);
1023 	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
1024 	apic_write(APIC_ID, reg0 ^ apic->apic_id_mask);
1025 	reg1 = apic_read(APIC_ID);
1026 	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
1027 	apic_write(APIC_ID, reg0);
1028 	if (reg1 != (reg0 ^ apic->apic_id_mask))
1029 		return 0;
1030 
1031 	/*
1032 	 * The next two are just to see if we have sane values.
1033 	 * They're only really relevant if we're in Virtual Wire
1034 	 * compatibility mode, but most boxes are anymore.
1035 	 */
1036 	reg0 = apic_read(APIC_LVT0);
1037 	apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
1038 	reg1 = apic_read(APIC_LVT1);
1039 	apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
1040 
1041 	return 1;
1042 }
1043 
1044 /**
1045  * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1046  */
1047 void __init sync_Arb_IDs(void)
1048 {
1049 	/*
1050 	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1051 	 * needed on AMD.
1052 	 */
1053 	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1054 		return;
1055 
1056 	/*
1057 	 * Wait for idle.
1058 	 */
1059 	apic_wait_icr_idle();
1060 
1061 	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1062 	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1063 			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1064 }
1065 
1066 /*
1067  * An initial setup of the virtual wire mode.
1068  */
1069 void __init init_bsp_APIC(void)
1070 {
1071 	unsigned int value;
1072 
1073 	/*
1074 	 * Don't do the setup now if we have a SMP BIOS as the
1075 	 * through-I/O-APIC virtual wire mode might be active.
1076 	 */
1077 	if (smp_found_config || !cpu_has_apic)
1078 		return;
1079 
1080 	/*
1081 	 * Do not trust the local APIC being empty at bootup.
1082 	 */
1083 	clear_local_APIC();
1084 
1085 	/*
1086 	 * Enable APIC.
1087 	 */
1088 	value = apic_read(APIC_SPIV);
1089 	value &= ~APIC_VECTOR_MASK;
1090 	value |= APIC_SPIV_APIC_ENABLED;
1091 
1092 #ifdef CONFIG_X86_32
1093 	/* This bit is reserved on P4/Xeon and should be cleared */
1094 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1095 	    (boot_cpu_data.x86 == 15))
1096 		value &= ~APIC_SPIV_FOCUS_DISABLED;
1097 	else
1098 #endif
1099 		value |= APIC_SPIV_FOCUS_DISABLED;
1100 	value |= SPURIOUS_APIC_VECTOR;
1101 	apic_write(APIC_SPIV, value);
1102 
1103 	/*
1104 	 * Set up the virtual wire mode.
1105 	 */
1106 	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1107 	value = APIC_DM_NMI;
1108 	if (!lapic_is_integrated())		/* 82489DX */
1109 		value |= APIC_LVT_LEVEL_TRIGGER;
1110 	apic_write(APIC_LVT1, value);
1111 }
1112 
1113 static void __cpuinit lapic_setup_esr(void)
1114 {
1115 	unsigned int oldvalue, value, maxlvt;
1116 
1117 	if (!lapic_is_integrated()) {
1118 		pr_info("No ESR for 82489DX.\n");
1119 		return;
1120 	}
1121 
1122 	if (apic->disable_esr) {
1123 		/*
1124 		 * Something untraceable is creating bad interrupts on
1125 		 * secondary quads ... for the moment, just leave the
1126 		 * ESR disabled - we can't do anything useful with the
1127 		 * errors anyway - mbligh
1128 		 */
1129 		pr_info("Leaving ESR disabled.\n");
1130 		return;
1131 	}
1132 
1133 	maxlvt = lapic_get_maxlvt();
1134 	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1135 		apic_write(APIC_ESR, 0);
1136 	oldvalue = apic_read(APIC_ESR);
1137 
1138 	/* enables sending errors */
1139 	value = ERROR_APIC_VECTOR;
1140 	apic_write(APIC_LVTERR, value);
1141 
1142 	/*
1143 	 * spec says clear errors after enabling vector.
1144 	 */
1145 	if (maxlvt > 3)
1146 		apic_write(APIC_ESR, 0);
1147 	value = apic_read(APIC_ESR);
1148 	if (value != oldvalue)
1149 		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1150 			"vector: 0x%08x  after: 0x%08x\n",
1151 			oldvalue, value);
1152 }
1153 
1154 
1155 /**
1156  * setup_local_APIC - setup the local APIC
1157  */
1158 void __cpuinit setup_local_APIC(void)
1159 {
1160 	unsigned int value;
1161 	int i, j;
1162 
1163 	if (disable_apic) {
1164 		arch_disable_smp_support();
1165 		return;
1166 	}
1167 
1168 #ifdef CONFIG_X86_32
1169 	/* Pound the ESR really hard over the head with a big hammer - mbligh */
1170 	if (lapic_is_integrated() && apic->disable_esr) {
1171 		apic_write(APIC_ESR, 0);
1172 		apic_write(APIC_ESR, 0);
1173 		apic_write(APIC_ESR, 0);
1174 		apic_write(APIC_ESR, 0);
1175 	}
1176 #endif
1177 	perf_events_lapic_init();
1178 
1179 	preempt_disable();
1180 
1181 	/*
1182 	 * Double-check whether this APIC is really registered.
1183 	 * This is meaningless in clustered apic mode, so we skip it.
1184 	 */
1185 	BUG_ON(!apic->apic_id_registered());
1186 
1187 	/*
1188 	 * Intel recommends to set DFR, LDR and TPR before enabling
1189 	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
1190 	 * document number 292116).  So here it goes...
1191 	 */
1192 	apic->init_apic_ldr();
1193 
1194 	/*
1195 	 * Set Task Priority to 'accept all'. We never change this
1196 	 * later on.
1197 	 */
1198 	value = apic_read(APIC_TASKPRI);
1199 	value &= ~APIC_TPRI_MASK;
1200 	apic_write(APIC_TASKPRI, value);
1201 
1202 	/*
1203 	 * After a crash, we no longer service the interrupts and a pending
1204 	 * interrupt from previous kernel might still have ISR bit set.
1205 	 *
1206 	 * Most probably by now CPU has serviced that pending interrupt and
1207 	 * it might not have done the ack_APIC_irq() because it thought,
1208 	 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1209 	 * does not clear the ISR bit and cpu thinks it has already serivced
1210 	 * the interrupt. Hence a vector might get locked. It was noticed
1211 	 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1212 	 */
1213 	for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1214 		value = apic_read(APIC_ISR + i*0x10);
1215 		for (j = 31; j >= 0; j--) {
1216 			if (value & (1<<j))
1217 				ack_APIC_irq();
1218 		}
1219 	}
1220 
1221 	/*
1222 	 * Now that we are all set up, enable the APIC
1223 	 */
1224 	value = apic_read(APIC_SPIV);
1225 	value &= ~APIC_VECTOR_MASK;
1226 	/*
1227 	 * Enable APIC
1228 	 */
1229 	value |= APIC_SPIV_APIC_ENABLED;
1230 
1231 #ifdef CONFIG_X86_32
1232 	/*
1233 	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1234 	 * certain networking cards. If high frequency interrupts are
1235 	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1236 	 * entry is masked/unmasked at a high rate as well then sooner or
1237 	 * later IOAPIC line gets 'stuck', no more interrupts are received
1238 	 * from the device. If focus CPU is disabled then the hang goes
1239 	 * away, oh well :-(
1240 	 *
1241 	 * [ This bug can be reproduced easily with a level-triggered
1242 	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1243 	 *   BX chipset. ]
1244 	 */
1245 	/*
1246 	 * Actually disabling the focus CPU check just makes the hang less
1247 	 * frequent as it makes the interrupt distributon model be more
1248 	 * like LRU than MRU (the short-term load is more even across CPUs).
1249 	 * See also the comment in end_level_ioapic_irq().  --macro
1250 	 */
1251 
1252 	/*
1253 	 * - enable focus processor (bit==0)
1254 	 * - 64bit mode always use processor focus
1255 	 *   so no need to set it
1256 	 */
1257 	value &= ~APIC_SPIV_FOCUS_DISABLED;
1258 #endif
1259 
1260 	/*
1261 	 * Set spurious IRQ vector
1262 	 */
1263 	value |= SPURIOUS_APIC_VECTOR;
1264 	apic_write(APIC_SPIV, value);
1265 
1266 	/*
1267 	 * Set up LVT0, LVT1:
1268 	 *
1269 	 * set up through-local-APIC on the BP's LINT0. This is not
1270 	 * strictly necessary in pure symmetric-IO mode, but sometimes
1271 	 * we delegate interrupts to the 8259A.
1272 	 */
1273 	/*
1274 	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1275 	 */
1276 	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1277 	if (!smp_processor_id() && (pic_mode || !value)) {
1278 		value = APIC_DM_EXTINT;
1279 		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n",
1280 				smp_processor_id());
1281 	} else {
1282 		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1283 		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n",
1284 				smp_processor_id());
1285 	}
1286 	apic_write(APIC_LVT0, value);
1287 
1288 	/*
1289 	 * only the BP should see the LINT1 NMI signal, obviously.
1290 	 */
1291 	if (!smp_processor_id())
1292 		value = APIC_DM_NMI;
1293 	else
1294 		value = APIC_DM_NMI | APIC_LVT_MASKED;
1295 	if (!lapic_is_integrated())		/* 82489DX */
1296 		value |= APIC_LVT_LEVEL_TRIGGER;
1297 	apic_write(APIC_LVT1, value);
1298 
1299 	preempt_enable();
1300 
1301 #ifdef CONFIG_X86_MCE_INTEL
1302 	/* Recheck CMCI information after local APIC is up on CPU #0 */
1303 	if (smp_processor_id() == 0)
1304 		cmci_recheck();
1305 #endif
1306 }
1307 
1308 void __cpuinit end_local_APIC_setup(void)
1309 {
1310 	lapic_setup_esr();
1311 
1312 #ifdef CONFIG_X86_32
1313 	{
1314 		unsigned int value;
1315 		/* Disable the local apic timer */
1316 		value = apic_read(APIC_LVTT);
1317 		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1318 		apic_write(APIC_LVTT, value);
1319 	}
1320 #endif
1321 
1322 	setup_apic_nmi_watchdog(NULL);
1323 	apic_pm_activate();
1324 }
1325 
1326 #ifdef CONFIG_X86_X2APIC
1327 void check_x2apic(void)
1328 {
1329 	if (x2apic_enabled()) {
1330 		pr_info("x2apic enabled by BIOS, switching to x2apic ops\n");
1331 		x2apic_preenabled = x2apic_mode = 1;
1332 	}
1333 }
1334 
1335 void enable_x2apic(void)
1336 {
1337 	int msr, msr2;
1338 
1339 	if (!x2apic_mode)
1340 		return;
1341 
1342 	rdmsr(MSR_IA32_APICBASE, msr, msr2);
1343 	if (!(msr & X2APIC_ENABLE)) {
1344 		printk_once(KERN_INFO "Enabling x2apic\n");
1345 		wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, 0);
1346 	}
1347 }
1348 #endif /* CONFIG_X86_X2APIC */
1349 
1350 int __init enable_IR(void)
1351 {
1352 #ifdef CONFIG_INTR_REMAP
1353 	if (!intr_remapping_supported()) {
1354 		pr_debug("intr-remapping not supported\n");
1355 		return 0;
1356 	}
1357 
1358 	if (!x2apic_preenabled && skip_ioapic_setup) {
1359 		pr_info("Skipped enabling intr-remap because of skipping "
1360 			"io-apic setup\n");
1361 		return 0;
1362 	}
1363 
1364 	if (enable_intr_remapping(x2apic_supported()))
1365 		return 0;
1366 
1367 	pr_info("Enabled Interrupt-remapping\n");
1368 
1369 	return 1;
1370 
1371 #endif
1372 	return 0;
1373 }
1374 
1375 void __init enable_IR_x2apic(void)
1376 {
1377 	unsigned long flags;
1378 	struct IO_APIC_route_entry **ioapic_entries = NULL;
1379 	int ret, x2apic_enabled = 0;
1380 	int dmar_table_init_ret;
1381 
1382 	dmar_table_init_ret = dmar_table_init();
1383 	if (dmar_table_init_ret && !x2apic_supported())
1384 		return;
1385 
1386 	ioapic_entries = alloc_ioapic_entries();
1387 	if (!ioapic_entries) {
1388 		pr_err("Allocate ioapic_entries failed\n");
1389 		goto out;
1390 	}
1391 
1392 	ret = save_IO_APIC_setup(ioapic_entries);
1393 	if (ret) {
1394 		pr_info("Saving IO-APIC state failed: %d\n", ret);
1395 		goto out;
1396 	}
1397 
1398 	local_irq_save(flags);
1399 	mask_8259A();
1400 	mask_IO_APIC_setup(ioapic_entries);
1401 
1402 	if (dmar_table_init_ret)
1403 		ret = 0;
1404 	else
1405 		ret = enable_IR();
1406 
1407 	if (!ret) {
1408 		/* IR is required if there is APIC ID > 255 even when running
1409 		 * under KVM
1410 		 */
1411 		if (max_physical_apicid > 255 || !kvm_para_available())
1412 			goto nox2apic;
1413 		/*
1414 		 * without IR all CPUs can be addressed by IOAPIC/MSI
1415 		 * only in physical mode
1416 		 */
1417 		x2apic_force_phys();
1418 	}
1419 
1420 	x2apic_enabled = 1;
1421 
1422 	if (x2apic_supported() && !x2apic_mode) {
1423 		x2apic_mode = 1;
1424 		enable_x2apic();
1425 		pr_info("Enabled x2apic\n");
1426 	}
1427 
1428 nox2apic:
1429 	if (!ret) /* IR enabling failed */
1430 		restore_IO_APIC_setup(ioapic_entries);
1431 	unmask_8259A();
1432 	local_irq_restore(flags);
1433 
1434 out:
1435 	if (ioapic_entries)
1436 		free_ioapic_entries(ioapic_entries);
1437 
1438 	if (x2apic_enabled)
1439 		return;
1440 
1441 	if (x2apic_preenabled)
1442 		panic("x2apic: enabled by BIOS but kernel init failed.");
1443 	else if (cpu_has_x2apic)
1444 		pr_info("Not enabling x2apic, Intr-remapping init failed.\n");
1445 }
1446 
1447 #ifdef CONFIG_X86_64
1448 /*
1449  * Detect and enable local APICs on non-SMP boards.
1450  * Original code written by Keir Fraser.
1451  * On AMD64 we trust the BIOS - if it says no APIC it is likely
1452  * not correctly set up (usually the APIC timer won't work etc.)
1453  */
1454 static int __init detect_init_APIC(void)
1455 {
1456 	if (!cpu_has_apic) {
1457 		pr_info("No local APIC present\n");
1458 		return -1;
1459 	}
1460 
1461 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1462 	return 0;
1463 }
1464 #else
1465 /*
1466  * Detect and initialize APIC
1467  */
1468 static int __init detect_init_APIC(void)
1469 {
1470 	u32 h, l, features;
1471 
1472 	/* Disabled by kernel option? */
1473 	if (disable_apic)
1474 		return -1;
1475 
1476 	switch (boot_cpu_data.x86_vendor) {
1477 	case X86_VENDOR_AMD:
1478 		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1479 		    (boot_cpu_data.x86 >= 15))
1480 			break;
1481 		goto no_apic;
1482 	case X86_VENDOR_INTEL:
1483 		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1484 		    (boot_cpu_data.x86 == 5 && cpu_has_apic))
1485 			break;
1486 		goto no_apic;
1487 	default:
1488 		goto no_apic;
1489 	}
1490 
1491 	if (!cpu_has_apic) {
1492 		/*
1493 		 * Over-ride BIOS and try to enable the local APIC only if
1494 		 * "lapic" specified.
1495 		 */
1496 		if (!force_enable_local_apic) {
1497 			pr_info("Local APIC disabled by BIOS -- "
1498 				"you can enable it with \"lapic\"\n");
1499 			return -1;
1500 		}
1501 		/*
1502 		 * Some BIOSes disable the local APIC in the APIC_BASE
1503 		 * MSR. This can only be done in software for Intel P6 or later
1504 		 * and AMD K7 (Model > 1) or later.
1505 		 */
1506 		rdmsr(MSR_IA32_APICBASE, l, h);
1507 		if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1508 			pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1509 			l &= ~MSR_IA32_APICBASE_BASE;
1510 			l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE;
1511 			wrmsr(MSR_IA32_APICBASE, l, h);
1512 			enabled_via_apicbase = 1;
1513 		}
1514 	}
1515 	/*
1516 	 * The APIC feature bit should now be enabled
1517 	 * in `cpuid'
1518 	 */
1519 	features = cpuid_edx(1);
1520 	if (!(features & (1 << X86_FEATURE_APIC))) {
1521 		pr_warning("Could not enable APIC!\n");
1522 		return -1;
1523 	}
1524 	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1525 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1526 
1527 	/* The BIOS may have set up the APIC at some other address */
1528 	rdmsr(MSR_IA32_APICBASE, l, h);
1529 	if (l & MSR_IA32_APICBASE_ENABLE)
1530 		mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1531 
1532 	pr_info("Found and enabled local APIC!\n");
1533 
1534 	apic_pm_activate();
1535 
1536 	return 0;
1537 
1538 no_apic:
1539 	pr_info("No local APIC present or hardware disabled\n");
1540 	return -1;
1541 }
1542 #endif
1543 
1544 #ifdef CONFIG_X86_64
1545 void __init early_init_lapic_mapping(void)
1546 {
1547 	/*
1548 	 * If no local APIC can be found then go out
1549 	 * : it means there is no mpatable and MADT
1550 	 */
1551 	if (!smp_found_config)
1552 		return;
1553 
1554 	set_fixmap_nocache(FIX_APIC_BASE, mp_lapic_addr);
1555 	apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
1556 		    APIC_BASE, mp_lapic_addr);
1557 
1558 	/*
1559 	 * Fetch the APIC ID of the BSP in case we have a
1560 	 * default configuration (or the MP table is broken).
1561 	 */
1562 	boot_cpu_physical_apicid = read_apic_id();
1563 }
1564 #endif
1565 
1566 /**
1567  * init_apic_mappings - initialize APIC mappings
1568  */
1569 void __init init_apic_mappings(void)
1570 {
1571 	unsigned int new_apicid;
1572 
1573 	if (x2apic_mode) {
1574 		boot_cpu_physical_apicid = read_apic_id();
1575 		return;
1576 	}
1577 
1578 	/* If no local APIC can be found return early */
1579 	if (!smp_found_config && detect_init_APIC()) {
1580 		/* lets NOP'ify apic operations */
1581 		pr_info("APIC: disable apic facility\n");
1582 		apic_disable();
1583 	} else {
1584 		apic_phys = mp_lapic_addr;
1585 
1586 		/*
1587 		 * acpi lapic path already maps that address in
1588 		 * acpi_register_lapic_address()
1589 		 */
1590 		if (!acpi_lapic)
1591 			set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
1592 
1593 		apic_printk(APIC_VERBOSE, "mapped APIC to %08lx (%08lx)\n",
1594 					APIC_BASE, apic_phys);
1595 	}
1596 
1597 	/*
1598 	 * Fetch the APIC ID of the BSP in case we have a
1599 	 * default configuration (or the MP table is broken).
1600 	 */
1601 	new_apicid = read_apic_id();
1602 	if (boot_cpu_physical_apicid != new_apicid) {
1603 		boot_cpu_physical_apicid = new_apicid;
1604 		/*
1605 		 * yeah -- we lie about apic_version
1606 		 * in case if apic was disabled via boot option
1607 		 * but it's not a problem for SMP compiled kernel
1608 		 * since smp_sanity_check is prepared for such a case
1609 		 * and disable smp mode
1610 		 */
1611 		apic_version[new_apicid] =
1612 			 GET_APIC_VERSION(apic_read(APIC_LVR));
1613 	}
1614 }
1615 
1616 /*
1617  * This initializes the IO-APIC and APIC hardware if this is
1618  * a UP kernel.
1619  */
1620 int apic_version[MAX_APICS];
1621 
1622 int __init APIC_init_uniprocessor(void)
1623 {
1624 	if (disable_apic) {
1625 		pr_info("Apic disabled\n");
1626 		return -1;
1627 	}
1628 #ifdef CONFIG_X86_64
1629 	if (!cpu_has_apic) {
1630 		disable_apic = 1;
1631 		pr_info("Apic disabled by BIOS\n");
1632 		return -1;
1633 	}
1634 #else
1635 	if (!smp_found_config && !cpu_has_apic)
1636 		return -1;
1637 
1638 	/*
1639 	 * Complain if the BIOS pretends there is one.
1640 	 */
1641 	if (!cpu_has_apic &&
1642 	    APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
1643 		pr_err("BIOS bug, local APIC 0x%x not detected!...\n",
1644 			boot_cpu_physical_apicid);
1645 		return -1;
1646 	}
1647 #endif
1648 
1649 	enable_IR_x2apic();
1650 #ifdef CONFIG_X86_64
1651 	default_setup_apic_routing();
1652 #endif
1653 
1654 	verify_local_APIC();
1655 	connect_bsp_APIC();
1656 
1657 #ifdef CONFIG_X86_64
1658 	apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
1659 #else
1660 	/*
1661 	 * Hack: In case of kdump, after a crash, kernel might be booting
1662 	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
1663 	 * might be zero if read from MP tables. Get it from LAPIC.
1664 	 */
1665 # ifdef CONFIG_CRASH_DUMP
1666 	boot_cpu_physical_apicid = read_apic_id();
1667 # endif
1668 #endif
1669 	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
1670 	setup_local_APIC();
1671 
1672 #ifdef CONFIG_X86_IO_APIC
1673 	/*
1674 	 * Now enable IO-APICs, actually call clear_IO_APIC
1675 	 * We need clear_IO_APIC before enabling error vector
1676 	 */
1677 	if (!skip_ioapic_setup && nr_ioapics)
1678 		enable_IO_APIC();
1679 #endif
1680 
1681 	end_local_APIC_setup();
1682 
1683 #ifdef CONFIG_X86_IO_APIC
1684 	if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1685 		setup_IO_APIC();
1686 	else {
1687 		nr_ioapics = 0;
1688 		localise_nmi_watchdog();
1689 	}
1690 #else
1691 	localise_nmi_watchdog();
1692 #endif
1693 
1694 	x86_init.timers.setup_percpu_clockev();
1695 #ifdef CONFIG_X86_64
1696 	check_nmi_watchdog();
1697 #endif
1698 
1699 	return 0;
1700 }
1701 
1702 /*
1703  * Local APIC interrupts
1704  */
1705 
1706 /*
1707  * This interrupt should _never_ happen with our APIC/SMP architecture
1708  */
1709 void smp_spurious_interrupt(struct pt_regs *regs)
1710 {
1711 	u32 v;
1712 
1713 	exit_idle();
1714 	irq_enter();
1715 	/*
1716 	 * Check if this really is a spurious interrupt and ACK it
1717 	 * if it is a vectored one.  Just in case...
1718 	 * Spurious interrupts should not be ACKed.
1719 	 */
1720 	v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1721 	if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1722 		ack_APIC_irq();
1723 
1724 	inc_irq_stat(irq_spurious_count);
1725 
1726 	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
1727 	pr_info("spurious APIC interrupt on CPU#%d, "
1728 		"should never happen.\n", smp_processor_id());
1729 	irq_exit();
1730 }
1731 
1732 /*
1733  * This interrupt should never happen with our APIC/SMP architecture
1734  */
1735 void smp_error_interrupt(struct pt_regs *regs)
1736 {
1737 	u32 v, v1;
1738 
1739 	exit_idle();
1740 	irq_enter();
1741 	/* First tickle the hardware, only then report what went on. -- REW */
1742 	v = apic_read(APIC_ESR);
1743 	apic_write(APIC_ESR, 0);
1744 	v1 = apic_read(APIC_ESR);
1745 	ack_APIC_irq();
1746 	atomic_inc(&irq_err_count);
1747 
1748 	/*
1749 	 * Here is what the APIC error bits mean:
1750 	 * 0: Send CS error
1751 	 * 1: Receive CS error
1752 	 * 2: Send accept error
1753 	 * 3: Receive accept error
1754 	 * 4: Reserved
1755 	 * 5: Send illegal vector
1756 	 * 6: Received illegal vector
1757 	 * 7: Illegal register address
1758 	 */
1759 	pr_debug("APIC error on CPU%d: %02x(%02x)\n",
1760 		smp_processor_id(), v , v1);
1761 	irq_exit();
1762 }
1763 
1764 /**
1765  * connect_bsp_APIC - attach the APIC to the interrupt system
1766  */
1767 void __init connect_bsp_APIC(void)
1768 {
1769 #ifdef CONFIG_X86_32
1770 	if (pic_mode) {
1771 		/*
1772 		 * Do not trust the local APIC being empty at bootup.
1773 		 */
1774 		clear_local_APIC();
1775 		/*
1776 		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
1777 		 * local APIC to INT and NMI lines.
1778 		 */
1779 		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
1780 				"enabling APIC mode.\n");
1781 		imcr_pic_to_apic();
1782 	}
1783 #endif
1784 	if (apic->enable_apic_mode)
1785 		apic->enable_apic_mode();
1786 }
1787 
1788 /**
1789  * disconnect_bsp_APIC - detach the APIC from the interrupt system
1790  * @virt_wire_setup:	indicates, whether virtual wire mode is selected
1791  *
1792  * Virtual wire mode is necessary to deliver legacy interrupts even when the
1793  * APIC is disabled.
1794  */
1795 void disconnect_bsp_APIC(int virt_wire_setup)
1796 {
1797 	unsigned int value;
1798 
1799 #ifdef CONFIG_X86_32
1800 	if (pic_mode) {
1801 		/*
1802 		 * Put the board back into PIC mode (has an effect only on
1803 		 * certain older boards).  Note that APIC interrupts, including
1804 		 * IPIs, won't work beyond this point!  The only exception are
1805 		 * INIT IPIs.
1806 		 */
1807 		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
1808 				"entering PIC mode.\n");
1809 		imcr_apic_to_pic();
1810 		return;
1811 	}
1812 #endif
1813 
1814 	/* Go back to Virtual Wire compatibility mode */
1815 
1816 	/* For the spurious interrupt use vector F, and enable it */
1817 	value = apic_read(APIC_SPIV);
1818 	value &= ~APIC_VECTOR_MASK;
1819 	value |= APIC_SPIV_APIC_ENABLED;
1820 	value |= 0xf;
1821 	apic_write(APIC_SPIV, value);
1822 
1823 	if (!virt_wire_setup) {
1824 		/*
1825 		 * For LVT0 make it edge triggered, active high,
1826 		 * external and enabled
1827 		 */
1828 		value = apic_read(APIC_LVT0);
1829 		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1830 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1831 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1832 		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1833 		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1834 		apic_write(APIC_LVT0, value);
1835 	} else {
1836 		/* Disable LVT0 */
1837 		apic_write(APIC_LVT0, APIC_LVT_MASKED);
1838 	}
1839 
1840 	/*
1841 	 * For LVT1 make it edge triggered, active high,
1842 	 * nmi and enabled
1843 	 */
1844 	value = apic_read(APIC_LVT1);
1845 	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1846 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1847 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1848 	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1849 	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1850 	apic_write(APIC_LVT1, value);
1851 }
1852 
1853 void __cpuinit generic_processor_info(int apicid, int version)
1854 {
1855 	int cpu;
1856 
1857 	/*
1858 	 * Validate version
1859 	 */
1860 	if (version == 0x0) {
1861 		pr_warning("BIOS bug, APIC version is 0 for CPU#%d! "
1862 			   "fixing up to 0x10. (tell your hw vendor)\n",
1863 				version);
1864 		version = 0x10;
1865 	}
1866 	apic_version[apicid] = version;
1867 
1868 	if (num_processors >= nr_cpu_ids) {
1869 		int max = nr_cpu_ids;
1870 		int thiscpu = max + disabled_cpus;
1871 
1872 		pr_warning(
1873 			"ACPI: NR_CPUS/possible_cpus limit of %i reached."
1874 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
1875 
1876 		disabled_cpus++;
1877 		return;
1878 	}
1879 
1880 	num_processors++;
1881 	cpu = cpumask_next_zero(-1, cpu_present_mask);
1882 
1883 	if (version != apic_version[boot_cpu_physical_apicid])
1884 		WARN_ONCE(1,
1885 			"ACPI: apic version mismatch, bootcpu: %x cpu %d: %x\n",
1886 			apic_version[boot_cpu_physical_apicid], cpu, version);
1887 
1888 	physid_set(apicid, phys_cpu_present_map);
1889 	if (apicid == boot_cpu_physical_apicid) {
1890 		/*
1891 		 * x86_bios_cpu_apicid is required to have processors listed
1892 		 * in same order as logical cpu numbers. Hence the first
1893 		 * entry is BSP, and so on.
1894 		 */
1895 		cpu = 0;
1896 	}
1897 	if (apicid > max_physical_apicid)
1898 		max_physical_apicid = apicid;
1899 
1900 #ifdef CONFIG_X86_32
1901 	/*
1902 	 * Would be preferable to switch to bigsmp when CONFIG_HOTPLUG_CPU=y
1903 	 * but we need to work other dependencies like SMP_SUSPEND etc
1904 	 * before this can be done without some confusion.
1905 	 * if (CPU_HOTPLUG_ENABLED || num_processors > 8)
1906 	 *       - Ashok Raj <ashok.raj@intel.com>
1907 	 */
1908 	if (max_physical_apicid >= 8) {
1909 		switch (boot_cpu_data.x86_vendor) {
1910 		case X86_VENDOR_INTEL:
1911 			if (!APIC_XAPIC(version)) {
1912 				def_to_bigsmp = 0;
1913 				break;
1914 			}
1915 			/* If P4 and above fall through */
1916 		case X86_VENDOR_AMD:
1917 			def_to_bigsmp = 1;
1918 		}
1919 	}
1920 #endif
1921 
1922 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
1923 	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
1924 	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
1925 #endif
1926 
1927 	set_cpu_possible(cpu, true);
1928 	set_cpu_present(cpu, true);
1929 }
1930 
1931 int hard_smp_processor_id(void)
1932 {
1933 	return read_apic_id();
1934 }
1935 
1936 void default_init_apic_ldr(void)
1937 {
1938 	unsigned long val;
1939 
1940 	apic_write(APIC_DFR, APIC_DFR_VALUE);
1941 	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
1942 	val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
1943 	apic_write(APIC_LDR, val);
1944 }
1945 
1946 #ifdef CONFIG_X86_32
1947 int default_apicid_to_node(int logical_apicid)
1948 {
1949 #ifdef CONFIG_SMP
1950 	return apicid_2_node[hard_smp_processor_id()];
1951 #else
1952 	return 0;
1953 #endif
1954 }
1955 #endif
1956 
1957 /*
1958  * Power management
1959  */
1960 #ifdef CONFIG_PM
1961 
1962 static struct {
1963 	/*
1964 	 * 'active' is true if the local APIC was enabled by us and
1965 	 * not the BIOS; this signifies that we are also responsible
1966 	 * for disabling it before entering apm/acpi suspend
1967 	 */
1968 	int active;
1969 	/* r/w apic fields */
1970 	unsigned int apic_id;
1971 	unsigned int apic_taskpri;
1972 	unsigned int apic_ldr;
1973 	unsigned int apic_dfr;
1974 	unsigned int apic_spiv;
1975 	unsigned int apic_lvtt;
1976 	unsigned int apic_lvtpc;
1977 	unsigned int apic_lvt0;
1978 	unsigned int apic_lvt1;
1979 	unsigned int apic_lvterr;
1980 	unsigned int apic_tmict;
1981 	unsigned int apic_tdcr;
1982 	unsigned int apic_thmr;
1983 } apic_pm_state;
1984 
1985 static int lapic_suspend(struct sys_device *dev, pm_message_t state)
1986 {
1987 	unsigned long flags;
1988 	int maxlvt;
1989 
1990 	if (!apic_pm_state.active)
1991 		return 0;
1992 
1993 	maxlvt = lapic_get_maxlvt();
1994 
1995 	apic_pm_state.apic_id = apic_read(APIC_ID);
1996 	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
1997 	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
1998 	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
1999 	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2000 	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2001 	if (maxlvt >= 4)
2002 		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2003 	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2004 	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2005 	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2006 	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2007 	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2008 #ifdef CONFIG_X86_THERMAL_VECTOR
2009 	if (maxlvt >= 5)
2010 		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2011 #endif
2012 
2013 	local_irq_save(flags);
2014 	disable_local_APIC();
2015 
2016 	if (intr_remapping_enabled)
2017 		disable_intr_remapping();
2018 
2019 	local_irq_restore(flags);
2020 	return 0;
2021 }
2022 
2023 static int lapic_resume(struct sys_device *dev)
2024 {
2025 	unsigned int l, h;
2026 	unsigned long flags;
2027 	int maxlvt;
2028 	int ret = 0;
2029 	struct IO_APIC_route_entry **ioapic_entries = NULL;
2030 
2031 	if (!apic_pm_state.active)
2032 		return 0;
2033 
2034 	local_irq_save(flags);
2035 	if (intr_remapping_enabled) {
2036 		ioapic_entries = alloc_ioapic_entries();
2037 		if (!ioapic_entries) {
2038 			WARN(1, "Alloc ioapic_entries in lapic resume failed.");
2039 			ret = -ENOMEM;
2040 			goto restore;
2041 		}
2042 
2043 		ret = save_IO_APIC_setup(ioapic_entries);
2044 		if (ret) {
2045 			WARN(1, "Saving IO-APIC state failed: %d\n", ret);
2046 			free_ioapic_entries(ioapic_entries);
2047 			goto restore;
2048 		}
2049 
2050 		mask_IO_APIC_setup(ioapic_entries);
2051 		mask_8259A();
2052 	}
2053 
2054 	if (x2apic_mode)
2055 		enable_x2apic();
2056 	else {
2057 		/*
2058 		 * Make sure the APICBASE points to the right address
2059 		 *
2060 		 * FIXME! This will be wrong if we ever support suspend on
2061 		 * SMP! We'll need to do this as part of the CPU restore!
2062 		 */
2063 		rdmsr(MSR_IA32_APICBASE, l, h);
2064 		l &= ~MSR_IA32_APICBASE_BASE;
2065 		l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2066 		wrmsr(MSR_IA32_APICBASE, l, h);
2067 	}
2068 
2069 	maxlvt = lapic_get_maxlvt();
2070 	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2071 	apic_write(APIC_ID, apic_pm_state.apic_id);
2072 	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2073 	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2074 	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2075 	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2076 	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2077 	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2078 #if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
2079 	if (maxlvt >= 5)
2080 		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2081 #endif
2082 	if (maxlvt >= 4)
2083 		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2084 	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2085 	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2086 	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2087 	apic_write(APIC_ESR, 0);
2088 	apic_read(APIC_ESR);
2089 	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2090 	apic_write(APIC_ESR, 0);
2091 	apic_read(APIC_ESR);
2092 
2093 	if (intr_remapping_enabled) {
2094 		reenable_intr_remapping(x2apic_mode);
2095 		unmask_8259A();
2096 		restore_IO_APIC_setup(ioapic_entries);
2097 		free_ioapic_entries(ioapic_entries);
2098 	}
2099 restore:
2100 	local_irq_restore(flags);
2101 
2102 	return ret;
2103 }
2104 
2105 /*
2106  * This device has no shutdown method - fully functioning local APICs
2107  * are needed on every CPU up until machine_halt/restart/poweroff.
2108  */
2109 
2110 static struct sysdev_class lapic_sysclass = {
2111 	.name		= "lapic",
2112 	.resume		= lapic_resume,
2113 	.suspend	= lapic_suspend,
2114 };
2115 
2116 static struct sys_device device_lapic = {
2117 	.id	= 0,
2118 	.cls	= &lapic_sysclass,
2119 };
2120 
2121 static void __cpuinit apic_pm_activate(void)
2122 {
2123 	apic_pm_state.active = 1;
2124 }
2125 
2126 static int __init init_lapic_sysfs(void)
2127 {
2128 	int error;
2129 
2130 	if (!cpu_has_apic)
2131 		return 0;
2132 	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2133 
2134 	error = sysdev_class_register(&lapic_sysclass);
2135 	if (!error)
2136 		error = sysdev_register(&device_lapic);
2137 	return error;
2138 }
2139 
2140 /* local apic needs to resume before other devices access its registers. */
2141 core_initcall(init_lapic_sysfs);
2142 
2143 #else	/* CONFIG_PM */
2144 
2145 static void apic_pm_activate(void) { }
2146 
2147 #endif	/* CONFIG_PM */
2148 
2149 #ifdef CONFIG_X86_64
2150 
2151 static int __cpuinit apic_cluster_num(void)
2152 {
2153 	int i, clusters, zeros;
2154 	unsigned id;
2155 	u16 *bios_cpu_apicid;
2156 	DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
2157 
2158 	bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
2159 	bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
2160 
2161 	for (i = 0; i < nr_cpu_ids; i++) {
2162 		/* are we being called early in kernel startup? */
2163 		if (bios_cpu_apicid) {
2164 			id = bios_cpu_apicid[i];
2165 		} else if (i < nr_cpu_ids) {
2166 			if (cpu_present(i))
2167 				id = per_cpu(x86_bios_cpu_apicid, i);
2168 			else
2169 				continue;
2170 		} else
2171 			break;
2172 
2173 		if (id != BAD_APICID)
2174 			__set_bit(APIC_CLUSTERID(id), clustermap);
2175 	}
2176 
2177 	/* Problem:  Partially populated chassis may not have CPUs in some of
2178 	 * the APIC clusters they have been allocated.  Only present CPUs have
2179 	 * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap.
2180 	 * Since clusters are allocated sequentially, count zeros only if
2181 	 * they are bounded by ones.
2182 	 */
2183 	clusters = 0;
2184 	zeros = 0;
2185 	for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
2186 		if (test_bit(i, clustermap)) {
2187 			clusters += 1 + zeros;
2188 			zeros = 0;
2189 		} else
2190 			++zeros;
2191 	}
2192 
2193 	return clusters;
2194 }
2195 
2196 static int __cpuinitdata multi_checked;
2197 static int __cpuinitdata multi;
2198 
2199 static int __cpuinit set_multi(const struct dmi_system_id *d)
2200 {
2201 	if (multi)
2202 		return 0;
2203 	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2204 	multi = 1;
2205 	return 0;
2206 }
2207 
2208 static const __cpuinitconst struct dmi_system_id multi_dmi_table[] = {
2209 	{
2210 		.callback = set_multi,
2211 		.ident = "IBM System Summit2",
2212 		.matches = {
2213 			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2214 			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2215 		},
2216 	},
2217 	{}
2218 };
2219 
2220 static void __cpuinit dmi_check_multi(void)
2221 {
2222 	if (multi_checked)
2223 		return;
2224 
2225 	dmi_check_system(multi_dmi_table);
2226 	multi_checked = 1;
2227 }
2228 
2229 /*
2230  * apic_is_clustered_box() -- Check if we can expect good TSC
2231  *
2232  * Thus far, the major user of this is IBM's Summit2 series:
2233  * Clustered boxes may have unsynced TSC problems if they are
2234  * multi-chassis.
2235  * Use DMI to check them
2236  */
2237 __cpuinit int apic_is_clustered_box(void)
2238 {
2239 	dmi_check_multi();
2240 	if (multi)
2241 		return 1;
2242 
2243 	if (!is_vsmp_box())
2244 		return 0;
2245 
2246 	/*
2247 	 * ScaleMP vSMPowered boxes have one cluster per board and TSCs are
2248 	 * not guaranteed to be synced between boards
2249 	 */
2250 	if (apic_cluster_num() > 1)
2251 		return 1;
2252 
2253 	return 0;
2254 }
2255 #endif
2256 
2257 /*
2258  * APIC command line parameters
2259  */
2260 static int __init setup_disableapic(char *arg)
2261 {
2262 	disable_apic = 1;
2263 	setup_clear_cpu_cap(X86_FEATURE_APIC);
2264 	return 0;
2265 }
2266 early_param("disableapic", setup_disableapic);
2267 
2268 /* same as disableapic, for compatibility */
2269 static int __init setup_nolapic(char *arg)
2270 {
2271 	return setup_disableapic(arg);
2272 }
2273 early_param("nolapic", setup_nolapic);
2274 
2275 static int __init parse_lapic_timer_c2_ok(char *arg)
2276 {
2277 	local_apic_timer_c2_ok = 1;
2278 	return 0;
2279 }
2280 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2281 
2282 static int __init parse_disable_apic_timer(char *arg)
2283 {
2284 	disable_apic_timer = 1;
2285 	return 0;
2286 }
2287 early_param("noapictimer", parse_disable_apic_timer);
2288 
2289 static int __init parse_nolapic_timer(char *arg)
2290 {
2291 	disable_apic_timer = 1;
2292 	return 0;
2293 }
2294 early_param("nolapic_timer", parse_nolapic_timer);
2295 
2296 static int __init apic_set_verbosity(char *arg)
2297 {
2298 	if (!arg)  {
2299 #ifdef CONFIG_X86_64
2300 		skip_ioapic_setup = 0;
2301 		return 0;
2302 #endif
2303 		return -EINVAL;
2304 	}
2305 
2306 	if (strcmp("debug", arg) == 0)
2307 		apic_verbosity = APIC_DEBUG;
2308 	else if (strcmp("verbose", arg) == 0)
2309 		apic_verbosity = APIC_VERBOSE;
2310 	else {
2311 		pr_warning("APIC Verbosity level %s not recognised"
2312 			" use apic=verbose or apic=debug\n", arg);
2313 		return -EINVAL;
2314 	}
2315 
2316 	return 0;
2317 }
2318 early_param("apic", apic_set_verbosity);
2319 
2320 static int __init lapic_insert_resource(void)
2321 {
2322 	if (!apic_phys)
2323 		return -1;
2324 
2325 	/* Put local APIC into the resource map. */
2326 	lapic_resource.start = apic_phys;
2327 	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2328 	insert_resource(&iomem_resource, &lapic_resource);
2329 
2330 	return 0;
2331 }
2332 
2333 /*
2334  * need call insert after e820_reserve_resources()
2335  * that is using request_resource
2336  */
2337 late_initcall(lapic_insert_resource);
2338