xref: /openbmc/linux/arch/x86/kernel/apic/apic.c (revision 82ced6fd)
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/kernel_stat.h>
18 #include <linux/mc146818rtc.h>
19 #include <linux/acpi_pmtmr.h>
20 #include <linux/clockchips.h>
21 #include <linux/interrupt.h>
22 #include <linux/bootmem.h>
23 #include <linux/ftrace.h>
24 #include <linux/ioport.h>
25 #include <linux/module.h>
26 #include <linux/sysdev.h>
27 #include <linux/delay.h>
28 #include <linux/timex.h>
29 #include <linux/dmar.h>
30 #include <linux/init.h>
31 #include <linux/cpu.h>
32 #include <linux/dmi.h>
33 #include <linux/nmi.h>
34 #include <linux/smp.h>
35 #include <linux/mm.h>
36 
37 #include <asm/pgalloc.h>
38 #include <asm/atomic.h>
39 #include <asm/mpspec.h>
40 #include <asm/i8253.h>
41 #include <asm/i8259.h>
42 #include <asm/proto.h>
43 #include <asm/apic.h>
44 #include <asm/desc.h>
45 #include <asm/hpet.h>
46 #include <asm/idle.h>
47 #include <asm/mtrr.h>
48 #include <asm/smp.h>
49 #include <asm/mce.h>
50 
51 unsigned int num_processors;
52 
53 unsigned disabled_cpus __cpuinitdata;
54 
55 /* Processor that is doing the boot up */
56 unsigned int boot_cpu_physical_apicid = -1U;
57 
58 /*
59  * The highest APIC ID seen during enumeration.
60  *
61  * This determines the messaging protocol we can use: if all APIC IDs
62  * are in the 0 ... 7 range, then we can use logical addressing which
63  * has some performance advantages (better broadcasting).
64  *
65  * If there's an APIC ID above 8, we use physical addressing.
66  */
67 unsigned int max_physical_apicid;
68 
69 /*
70  * Bitmask of physically existing CPUs:
71  */
72 physid_mask_t phys_cpu_present_map;
73 
74 /*
75  * Map cpu index to physical APIC ID
76  */
77 DEFINE_EARLY_PER_CPU(u16, x86_cpu_to_apicid, BAD_APICID);
78 DEFINE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid, BAD_APICID);
79 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
80 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
81 
82 #ifdef CONFIG_X86_32
83 /*
84  * Knob to control our willingness to enable the local APIC.
85  *
86  * +1=force-enable
87  */
88 static int force_enable_local_apic;
89 /*
90  * APIC command line parameters
91  */
92 static int __init parse_lapic(char *arg)
93 {
94 	force_enable_local_apic = 1;
95 	return 0;
96 }
97 early_param("lapic", parse_lapic);
98 /* Local APIC was disabled by the BIOS and enabled by the kernel */
99 static int enabled_via_apicbase;
100 
101 #endif
102 
103 #ifdef CONFIG_X86_64
104 static int apic_calibrate_pmtmr __initdata;
105 static __init int setup_apicpmtimer(char *s)
106 {
107 	apic_calibrate_pmtmr = 1;
108 	notsc_setup(NULL);
109 	return 0;
110 }
111 __setup("apicpmtimer", setup_apicpmtimer);
112 #endif
113 
114 #ifdef CONFIG_X86_X2APIC
115 int x2apic;
116 /* x2apic enabled before OS handover */
117 static int x2apic_preenabled;
118 static int disable_x2apic;
119 static __init int setup_nox2apic(char *str)
120 {
121 	disable_x2apic = 1;
122 	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
123 	return 0;
124 }
125 early_param("nox2apic", setup_nox2apic);
126 #endif
127 
128 unsigned long mp_lapic_addr;
129 int disable_apic;
130 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
131 static int disable_apic_timer __cpuinitdata;
132 /* Local APIC timer works in C2 */
133 int local_apic_timer_c2_ok;
134 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
135 
136 int first_system_vector = 0xfe;
137 
138 /*
139  * Debug level, exported for io_apic.c
140  */
141 unsigned int apic_verbosity;
142 
143 int pic_mode;
144 
145 /* Have we found an MP table */
146 int smp_found_config;
147 
148 static struct resource lapic_resource = {
149 	.name = "Local APIC",
150 	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
151 };
152 
153 static unsigned int calibration_result;
154 
155 static int lapic_next_event(unsigned long delta,
156 			    struct clock_event_device *evt);
157 static void lapic_timer_setup(enum clock_event_mode mode,
158 			      struct clock_event_device *evt);
159 static void lapic_timer_broadcast(const struct cpumask *mask);
160 static void apic_pm_activate(void);
161 
162 /*
163  * The local apic timer can be used for any function which is CPU local.
164  */
165 static struct clock_event_device lapic_clockevent = {
166 	.name		= "lapic",
167 	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
168 			| CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
169 	.shift		= 32,
170 	.set_mode	= lapic_timer_setup,
171 	.set_next_event	= lapic_next_event,
172 	.broadcast	= lapic_timer_broadcast,
173 	.rating		= 100,
174 	.irq		= -1,
175 };
176 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
177 
178 static unsigned long apic_phys;
179 
180 /*
181  * Get the LAPIC version
182  */
183 static inline int lapic_get_version(void)
184 {
185 	return GET_APIC_VERSION(apic_read(APIC_LVR));
186 }
187 
188 /*
189  * Check, if the APIC is integrated or a separate chip
190  */
191 static inline int lapic_is_integrated(void)
192 {
193 #ifdef CONFIG_X86_64
194 	return 1;
195 #else
196 	return APIC_INTEGRATED(lapic_get_version());
197 #endif
198 }
199 
200 /*
201  * Check, whether this is a modern or a first generation APIC
202  */
203 static int modern_apic(void)
204 {
205 	/* AMD systems use old APIC versions, so check the CPU */
206 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
207 	    boot_cpu_data.x86 >= 0xf)
208 		return 1;
209 	return lapic_get_version() >= 0x14;
210 }
211 
212 void native_apic_wait_icr_idle(void)
213 {
214 	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
215 		cpu_relax();
216 }
217 
218 u32 native_safe_apic_wait_icr_idle(void)
219 {
220 	u32 send_status;
221 	int timeout;
222 
223 	timeout = 0;
224 	do {
225 		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
226 		if (!send_status)
227 			break;
228 		udelay(100);
229 	} while (timeout++ < 1000);
230 
231 	return send_status;
232 }
233 
234 void native_apic_icr_write(u32 low, u32 id)
235 {
236 	apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
237 	apic_write(APIC_ICR, low);
238 }
239 
240 u64 native_apic_icr_read(void)
241 {
242 	u32 icr1, icr2;
243 
244 	icr2 = apic_read(APIC_ICR2);
245 	icr1 = apic_read(APIC_ICR);
246 
247 	return icr1 | ((u64)icr2 << 32);
248 }
249 
250 /**
251  * enable_NMI_through_LVT0 - enable NMI through local vector table 0
252  */
253 void __cpuinit enable_NMI_through_LVT0(void)
254 {
255 	unsigned int v;
256 
257 	/* unmask and set to NMI */
258 	v = APIC_DM_NMI;
259 
260 	/* Level triggered for 82489DX (32bit mode) */
261 	if (!lapic_is_integrated())
262 		v |= APIC_LVT_LEVEL_TRIGGER;
263 
264 	apic_write(APIC_LVT0, v);
265 }
266 
267 #ifdef CONFIG_X86_32
268 /**
269  * get_physical_broadcast - Get number of physical broadcast IDs
270  */
271 int get_physical_broadcast(void)
272 {
273 	return modern_apic() ? 0xff : 0xf;
274 }
275 #endif
276 
277 /**
278  * lapic_get_maxlvt - get the maximum number of local vector table entries
279  */
280 int lapic_get_maxlvt(void)
281 {
282 	unsigned int v;
283 
284 	v = apic_read(APIC_LVR);
285 	/*
286 	 * - we always have APIC integrated on 64bit mode
287 	 * - 82489DXs do not report # of LVT entries
288 	 */
289 	return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
290 }
291 
292 /*
293  * Local APIC timer
294  */
295 
296 /* Clock divisor */
297 #define APIC_DIVISOR 16
298 
299 /*
300  * This function sets up the local APIC timer, with a timeout of
301  * 'clocks' APIC bus clock. During calibration we actually call
302  * this function twice on the boot CPU, once with a bogus timeout
303  * value, second time for real. The other (noncalibrating) CPUs
304  * call this function only once, with the real, calibrated value.
305  *
306  * We do reads before writes even if unnecessary, to get around the
307  * P5 APIC double write bug.
308  */
309 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
310 {
311 	unsigned int lvtt_value, tmp_value;
312 
313 	lvtt_value = LOCAL_TIMER_VECTOR;
314 	if (!oneshot)
315 		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
316 	if (!lapic_is_integrated())
317 		lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
318 
319 	if (!irqen)
320 		lvtt_value |= APIC_LVT_MASKED;
321 
322 	apic_write(APIC_LVTT, lvtt_value);
323 
324 	/*
325 	 * Divide PICLK by 16
326 	 */
327 	tmp_value = apic_read(APIC_TDCR);
328 	apic_write(APIC_TDCR,
329 		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
330 		APIC_TDR_DIV_16);
331 
332 	if (!oneshot)
333 		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
334 }
335 
336 /*
337  * Setup extended LVT, AMD specific (K8, family 10h)
338  *
339  * Vector mappings are hard coded. On K8 only offset 0 (APIC500) and
340  * MCE interrupts are supported. Thus MCE offset must be set to 0.
341  *
342  * If mask=1, the LVT entry does not generate interrupts while mask=0
343  * enables the vector. See also the BKDGs.
344  */
345 
346 #define APIC_EILVT_LVTOFF_MCE 0
347 #define APIC_EILVT_LVTOFF_IBS 1
348 
349 static void setup_APIC_eilvt(u8 lvt_off, u8 vector, u8 msg_type, u8 mask)
350 {
351 	unsigned long reg = (lvt_off << 4) + APIC_EILVT0;
352 	unsigned int  v   = (mask << 16) | (msg_type << 8) | vector;
353 
354 	apic_write(reg, v);
355 }
356 
357 u8 setup_APIC_eilvt_mce(u8 vector, u8 msg_type, u8 mask)
358 {
359 	setup_APIC_eilvt(APIC_EILVT_LVTOFF_MCE, vector, msg_type, mask);
360 	return APIC_EILVT_LVTOFF_MCE;
361 }
362 
363 u8 setup_APIC_eilvt_ibs(u8 vector, u8 msg_type, u8 mask)
364 {
365 	setup_APIC_eilvt(APIC_EILVT_LVTOFF_IBS, vector, msg_type, mask);
366 	return APIC_EILVT_LVTOFF_IBS;
367 }
368 EXPORT_SYMBOL_GPL(setup_APIC_eilvt_ibs);
369 
370 /*
371  * Program the next event, relative to now
372  */
373 static int lapic_next_event(unsigned long delta,
374 			    struct clock_event_device *evt)
375 {
376 	apic_write(APIC_TMICT, delta);
377 	return 0;
378 }
379 
380 /*
381  * Setup the lapic timer in periodic or oneshot mode
382  */
383 static void lapic_timer_setup(enum clock_event_mode mode,
384 			      struct clock_event_device *evt)
385 {
386 	unsigned long flags;
387 	unsigned int v;
388 
389 	/* Lapic used as dummy for broadcast ? */
390 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
391 		return;
392 
393 	local_irq_save(flags);
394 
395 	switch (mode) {
396 	case CLOCK_EVT_MODE_PERIODIC:
397 	case CLOCK_EVT_MODE_ONESHOT:
398 		__setup_APIC_LVTT(calibration_result,
399 				  mode != CLOCK_EVT_MODE_PERIODIC, 1);
400 		break;
401 	case CLOCK_EVT_MODE_UNUSED:
402 	case CLOCK_EVT_MODE_SHUTDOWN:
403 		v = apic_read(APIC_LVTT);
404 		v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
405 		apic_write(APIC_LVTT, v);
406 		apic_write(APIC_TMICT, 0xffffffff);
407 		break;
408 	case CLOCK_EVT_MODE_RESUME:
409 		/* Nothing to do here */
410 		break;
411 	}
412 
413 	local_irq_restore(flags);
414 }
415 
416 /*
417  * Local APIC timer broadcast function
418  */
419 static void lapic_timer_broadcast(const struct cpumask *mask)
420 {
421 #ifdef CONFIG_SMP
422 	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
423 #endif
424 }
425 
426 /*
427  * Setup the local APIC timer for this CPU. Copy the initilized values
428  * of the boot CPU and register the clock event in the framework.
429  */
430 static void __cpuinit setup_APIC_timer(void)
431 {
432 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
433 
434 	if (cpu_has(&current_cpu_data, X86_FEATURE_ARAT)) {
435 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
436 		/* Make LAPIC timer preferrable over percpu HPET */
437 		lapic_clockevent.rating = 150;
438 	}
439 
440 	memcpy(levt, &lapic_clockevent, sizeof(*levt));
441 	levt->cpumask = cpumask_of(smp_processor_id());
442 
443 	clockevents_register_device(levt);
444 }
445 
446 /*
447  * In this functions we calibrate APIC bus clocks to the external timer.
448  *
449  * We want to do the calibration only once since we want to have local timer
450  * irqs syncron. CPUs connected by the same APIC bus have the very same bus
451  * frequency.
452  *
453  * This was previously done by reading the PIT/HPET and waiting for a wrap
454  * around to find out, that a tick has elapsed. I have a box, where the PIT
455  * readout is broken, so it never gets out of the wait loop again. This was
456  * also reported by others.
457  *
458  * Monitoring the jiffies value is inaccurate and the clockevents
459  * infrastructure allows us to do a simple substitution of the interrupt
460  * handler.
461  *
462  * The calibration routine also uses the pm_timer when possible, as the PIT
463  * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
464  * back to normal later in the boot process).
465  */
466 
467 #define LAPIC_CAL_LOOPS		(HZ/10)
468 
469 static __initdata int lapic_cal_loops = -1;
470 static __initdata long lapic_cal_t1, lapic_cal_t2;
471 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
472 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
473 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
474 
475 /*
476  * Temporary interrupt handler.
477  */
478 static void __init lapic_cal_handler(struct clock_event_device *dev)
479 {
480 	unsigned long long tsc = 0;
481 	long tapic = apic_read(APIC_TMCCT);
482 	unsigned long pm = acpi_pm_read_early();
483 
484 	if (cpu_has_tsc)
485 		rdtscll(tsc);
486 
487 	switch (lapic_cal_loops++) {
488 	case 0:
489 		lapic_cal_t1 = tapic;
490 		lapic_cal_tsc1 = tsc;
491 		lapic_cal_pm1 = pm;
492 		lapic_cal_j1 = jiffies;
493 		break;
494 
495 	case LAPIC_CAL_LOOPS:
496 		lapic_cal_t2 = tapic;
497 		lapic_cal_tsc2 = tsc;
498 		if (pm < lapic_cal_pm1)
499 			pm += ACPI_PM_OVRRUN;
500 		lapic_cal_pm2 = pm;
501 		lapic_cal_j2 = jiffies;
502 		break;
503 	}
504 }
505 
506 static int __init
507 calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
508 {
509 	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
510 	const long pm_thresh = pm_100ms / 100;
511 	unsigned long mult;
512 	u64 res;
513 
514 #ifndef CONFIG_X86_PM_TIMER
515 	return -1;
516 #endif
517 
518 	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
519 
520 	/* Check, if the PM timer is available */
521 	if (!deltapm)
522 		return -1;
523 
524 	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
525 
526 	if (deltapm > (pm_100ms - pm_thresh) &&
527 	    deltapm < (pm_100ms + pm_thresh)) {
528 		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
529 		return 0;
530 	}
531 
532 	res = (((u64)deltapm) *  mult) >> 22;
533 	do_div(res, 1000000);
534 	pr_warning("APIC calibration not consistent "
535 		   "with PM-Timer: %ldms instead of 100ms\n",(long)res);
536 
537 	/* Correct the lapic counter value */
538 	res = (((u64)(*delta)) * pm_100ms);
539 	do_div(res, deltapm);
540 	pr_info("APIC delta adjusted to PM-Timer: "
541 		"%lu (%ld)\n", (unsigned long)res, *delta);
542 	*delta = (long)res;
543 
544 	/* Correct the tsc counter value */
545 	if (cpu_has_tsc) {
546 		res = (((u64)(*deltatsc)) * pm_100ms);
547 		do_div(res, deltapm);
548 		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
549 					  "PM-Timer: %lu (%ld) \n",
550 					(unsigned long)res, *deltatsc);
551 		*deltatsc = (long)res;
552 	}
553 
554 	return 0;
555 }
556 
557 static int __init calibrate_APIC_clock(void)
558 {
559 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
560 	void (*real_handler)(struct clock_event_device *dev);
561 	unsigned long deltaj;
562 	long delta, deltatsc;
563 	int pm_referenced = 0;
564 
565 	local_irq_disable();
566 
567 	/* Replace the global interrupt handler */
568 	real_handler = global_clock_event->event_handler;
569 	global_clock_event->event_handler = lapic_cal_handler;
570 
571 	/*
572 	 * Setup the APIC counter to maximum. There is no way the lapic
573 	 * can underflow in the 100ms detection time frame
574 	 */
575 	__setup_APIC_LVTT(0xffffffff, 0, 0);
576 
577 	/* Let the interrupts run */
578 	local_irq_enable();
579 
580 	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
581 		cpu_relax();
582 
583 	local_irq_disable();
584 
585 	/* Restore the real event handler */
586 	global_clock_event->event_handler = real_handler;
587 
588 	/* Build delta t1-t2 as apic timer counts down */
589 	delta = lapic_cal_t1 - lapic_cal_t2;
590 	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
591 
592 	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
593 
594 	/* we trust the PM based calibration if possible */
595 	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
596 					&delta, &deltatsc);
597 
598 	/* Calculate the scaled math multiplication factor */
599 	lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
600 				       lapic_clockevent.shift);
601 	lapic_clockevent.max_delta_ns =
602 		clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
603 	lapic_clockevent.min_delta_ns =
604 		clockevent_delta2ns(0xF, &lapic_clockevent);
605 
606 	calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
607 
608 	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
609 	apic_printk(APIC_VERBOSE, "..... mult: %ld\n", lapic_clockevent.mult);
610 	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
611 		    calibration_result);
612 
613 	if (cpu_has_tsc) {
614 		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
615 			    "%ld.%04ld MHz.\n",
616 			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
617 			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
618 	}
619 
620 	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
621 		    "%u.%04u MHz.\n",
622 		    calibration_result / (1000000 / HZ),
623 		    calibration_result % (1000000 / HZ));
624 
625 	/*
626 	 * Do a sanity check on the APIC calibration result
627 	 */
628 	if (calibration_result < (1000000 / HZ)) {
629 		local_irq_enable();
630 		pr_warning("APIC frequency too slow, disabling apic timer\n");
631 		return -1;
632 	}
633 
634 	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
635 
636 	/*
637 	 * PM timer calibration failed or not turned on
638 	 * so lets try APIC timer based calibration
639 	 */
640 	if (!pm_referenced) {
641 		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
642 
643 		/*
644 		 * Setup the apic timer manually
645 		 */
646 		levt->event_handler = lapic_cal_handler;
647 		lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
648 		lapic_cal_loops = -1;
649 
650 		/* Let the interrupts run */
651 		local_irq_enable();
652 
653 		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
654 			cpu_relax();
655 
656 		/* Stop the lapic timer */
657 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
658 
659 		/* Jiffies delta */
660 		deltaj = lapic_cal_j2 - lapic_cal_j1;
661 		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
662 
663 		/* Check, if the jiffies result is consistent */
664 		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
665 			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
666 		else
667 			levt->features |= CLOCK_EVT_FEAT_DUMMY;
668 	} else
669 		local_irq_enable();
670 
671 	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
672 		pr_warning("APIC timer disabled due to verification failure\n");
673 			return -1;
674 	}
675 
676 	return 0;
677 }
678 
679 /*
680  * Setup the boot APIC
681  *
682  * Calibrate and verify the result.
683  */
684 void __init setup_boot_APIC_clock(void)
685 {
686 	/*
687 	 * The local apic timer can be disabled via the kernel
688 	 * commandline or from the CPU detection code. Register the lapic
689 	 * timer as a dummy clock event source on SMP systems, so the
690 	 * broadcast mechanism is used. On UP systems simply ignore it.
691 	 */
692 	if (disable_apic_timer) {
693 		pr_info("Disabling APIC timer\n");
694 		/* No broadcast on UP ! */
695 		if (num_possible_cpus() > 1) {
696 			lapic_clockevent.mult = 1;
697 			setup_APIC_timer();
698 		}
699 		return;
700 	}
701 
702 	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
703 		    "calibrating APIC timer ...\n");
704 
705 	if (calibrate_APIC_clock()) {
706 		/* No broadcast on UP ! */
707 		if (num_possible_cpus() > 1)
708 			setup_APIC_timer();
709 		return;
710 	}
711 
712 	/*
713 	 * If nmi_watchdog is set to IO_APIC, we need the
714 	 * PIT/HPET going.  Otherwise register lapic as a dummy
715 	 * device.
716 	 */
717 	if (nmi_watchdog != NMI_IO_APIC)
718 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
719 	else
720 		pr_warning("APIC timer registered as dummy,"
721 			" due to nmi_watchdog=%d!\n", nmi_watchdog);
722 
723 	/* Setup the lapic or request the broadcast */
724 	setup_APIC_timer();
725 }
726 
727 void __cpuinit setup_secondary_APIC_clock(void)
728 {
729 	setup_APIC_timer();
730 }
731 
732 /*
733  * The guts of the apic timer interrupt
734  */
735 static void local_apic_timer_interrupt(void)
736 {
737 	int cpu = smp_processor_id();
738 	struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
739 
740 	/*
741 	 * Normally we should not be here till LAPIC has been initialized but
742 	 * in some cases like kdump, its possible that there is a pending LAPIC
743 	 * timer interrupt from previous kernel's context and is delivered in
744 	 * new kernel the moment interrupts are enabled.
745 	 *
746 	 * Interrupts are enabled early and LAPIC is setup much later, hence
747 	 * its possible that when we get here evt->event_handler is NULL.
748 	 * Check for event_handler being NULL and discard the interrupt as
749 	 * spurious.
750 	 */
751 	if (!evt->event_handler) {
752 		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu);
753 		/* Switch it off */
754 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
755 		return;
756 	}
757 
758 	/*
759 	 * the NMI deadlock-detector uses this.
760 	 */
761 	inc_irq_stat(apic_timer_irqs);
762 
763 	evt->event_handler(evt);
764 }
765 
766 /*
767  * Local APIC timer interrupt. This is the most natural way for doing
768  * local interrupts, but local timer interrupts can be emulated by
769  * broadcast interrupts too. [in case the hw doesn't support APIC timers]
770  *
771  * [ if a single-CPU system runs an SMP kernel then we call the local
772  *   interrupt as well. Thus we cannot inline the local irq ... ]
773  */
774 void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
775 {
776 	struct pt_regs *old_regs = set_irq_regs(regs);
777 
778 	/*
779 	 * NOTE! We'd better ACK the irq immediately,
780 	 * because timer handling can be slow.
781 	 */
782 	ack_APIC_irq();
783 	/*
784 	 * update_process_times() expects us to have done irq_enter().
785 	 * Besides, if we don't timer interrupts ignore the global
786 	 * interrupt lock, which is the WrongThing (tm) to do.
787 	 */
788 	exit_idle();
789 	irq_enter();
790 	local_apic_timer_interrupt();
791 	irq_exit();
792 
793 	set_irq_regs(old_regs);
794 }
795 
796 int setup_profiling_timer(unsigned int multiplier)
797 {
798 	return -EINVAL;
799 }
800 
801 /*
802  * Local APIC start and shutdown
803  */
804 
805 /**
806  * clear_local_APIC - shutdown the local APIC
807  *
808  * This is called, when a CPU is disabled and before rebooting, so the state of
809  * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
810  * leftovers during boot.
811  */
812 void clear_local_APIC(void)
813 {
814 	int maxlvt;
815 	u32 v;
816 
817 	/* APIC hasn't been mapped yet */
818 	if (!x2apic && !apic_phys)
819 		return;
820 
821 	maxlvt = lapic_get_maxlvt();
822 	/*
823 	 * Masking an LVT entry can trigger a local APIC error
824 	 * if the vector is zero. Mask LVTERR first to prevent this.
825 	 */
826 	if (maxlvt >= 3) {
827 		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
828 		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
829 	}
830 	/*
831 	 * Careful: we have to set masks only first to deassert
832 	 * any level-triggered sources.
833 	 */
834 	v = apic_read(APIC_LVTT);
835 	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
836 	v = apic_read(APIC_LVT0);
837 	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
838 	v = apic_read(APIC_LVT1);
839 	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
840 	if (maxlvt >= 4) {
841 		v = apic_read(APIC_LVTPC);
842 		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
843 	}
844 
845 	/* lets not touch this if we didn't frob it */
846 #if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
847 	if (maxlvt >= 5) {
848 		v = apic_read(APIC_LVTTHMR);
849 		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
850 	}
851 #endif
852 #ifdef CONFIG_X86_MCE_INTEL
853 	if (maxlvt >= 6) {
854 		v = apic_read(APIC_LVTCMCI);
855 		if (!(v & APIC_LVT_MASKED))
856 			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
857 	}
858 #endif
859 
860 	/*
861 	 * Clean APIC state for other OSs:
862 	 */
863 	apic_write(APIC_LVTT, APIC_LVT_MASKED);
864 	apic_write(APIC_LVT0, APIC_LVT_MASKED);
865 	apic_write(APIC_LVT1, APIC_LVT_MASKED);
866 	if (maxlvt >= 3)
867 		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
868 	if (maxlvt >= 4)
869 		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
870 
871 	/* Integrated APIC (!82489DX) ? */
872 	if (lapic_is_integrated()) {
873 		if (maxlvt > 3)
874 			/* Clear ESR due to Pentium errata 3AP and 11AP */
875 			apic_write(APIC_ESR, 0);
876 		apic_read(APIC_ESR);
877 	}
878 }
879 
880 /**
881  * disable_local_APIC - clear and disable the local APIC
882  */
883 void disable_local_APIC(void)
884 {
885 	unsigned int value;
886 
887 	/* APIC hasn't been mapped yet */
888 	if (!apic_phys)
889 		return;
890 
891 	clear_local_APIC();
892 
893 	/*
894 	 * Disable APIC (implies clearing of registers
895 	 * for 82489DX!).
896 	 */
897 	value = apic_read(APIC_SPIV);
898 	value &= ~APIC_SPIV_APIC_ENABLED;
899 	apic_write(APIC_SPIV, value);
900 
901 #ifdef CONFIG_X86_32
902 	/*
903 	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
904 	 * restore the disabled state.
905 	 */
906 	if (enabled_via_apicbase) {
907 		unsigned int l, h;
908 
909 		rdmsr(MSR_IA32_APICBASE, l, h);
910 		l &= ~MSR_IA32_APICBASE_ENABLE;
911 		wrmsr(MSR_IA32_APICBASE, l, h);
912 	}
913 #endif
914 }
915 
916 /*
917  * If Linux enabled the LAPIC against the BIOS default disable it down before
918  * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
919  * not power-off.  Additionally clear all LVT entries before disable_local_APIC
920  * for the case where Linux didn't enable the LAPIC.
921  */
922 void lapic_shutdown(void)
923 {
924 	unsigned long flags;
925 
926 	if (!cpu_has_apic)
927 		return;
928 
929 	local_irq_save(flags);
930 
931 #ifdef CONFIG_X86_32
932 	if (!enabled_via_apicbase)
933 		clear_local_APIC();
934 	else
935 #endif
936 		disable_local_APIC();
937 
938 
939 	local_irq_restore(flags);
940 }
941 
942 /*
943  * This is to verify that we're looking at a real local APIC.
944  * Check these against your board if the CPUs aren't getting
945  * started for no apparent reason.
946  */
947 int __init verify_local_APIC(void)
948 {
949 	unsigned int reg0, reg1;
950 
951 	/*
952 	 * The version register is read-only in a real APIC.
953 	 */
954 	reg0 = apic_read(APIC_LVR);
955 	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
956 	apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
957 	reg1 = apic_read(APIC_LVR);
958 	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
959 
960 	/*
961 	 * The two version reads above should print the same
962 	 * numbers.  If the second one is different, then we
963 	 * poke at a non-APIC.
964 	 */
965 	if (reg1 != reg0)
966 		return 0;
967 
968 	/*
969 	 * Check if the version looks reasonably.
970 	 */
971 	reg1 = GET_APIC_VERSION(reg0);
972 	if (reg1 == 0x00 || reg1 == 0xff)
973 		return 0;
974 	reg1 = lapic_get_maxlvt();
975 	if (reg1 < 0x02 || reg1 == 0xff)
976 		return 0;
977 
978 	/*
979 	 * The ID register is read/write in a real APIC.
980 	 */
981 	reg0 = apic_read(APIC_ID);
982 	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
983 	apic_write(APIC_ID, reg0 ^ apic->apic_id_mask);
984 	reg1 = apic_read(APIC_ID);
985 	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
986 	apic_write(APIC_ID, reg0);
987 	if (reg1 != (reg0 ^ apic->apic_id_mask))
988 		return 0;
989 
990 	/*
991 	 * The next two are just to see if we have sane values.
992 	 * They're only really relevant if we're in Virtual Wire
993 	 * compatibility mode, but most boxes are anymore.
994 	 */
995 	reg0 = apic_read(APIC_LVT0);
996 	apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
997 	reg1 = apic_read(APIC_LVT1);
998 	apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
999 
1000 	return 1;
1001 }
1002 
1003 /**
1004  * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1005  */
1006 void __init sync_Arb_IDs(void)
1007 {
1008 	/*
1009 	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1010 	 * needed on AMD.
1011 	 */
1012 	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1013 		return;
1014 
1015 	/*
1016 	 * Wait for idle.
1017 	 */
1018 	apic_wait_icr_idle();
1019 
1020 	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1021 	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1022 			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1023 }
1024 
1025 /*
1026  * An initial setup of the virtual wire mode.
1027  */
1028 void __init init_bsp_APIC(void)
1029 {
1030 	unsigned int value;
1031 
1032 	/*
1033 	 * Don't do the setup now if we have a SMP BIOS as the
1034 	 * through-I/O-APIC virtual wire mode might be active.
1035 	 */
1036 	if (smp_found_config || !cpu_has_apic)
1037 		return;
1038 
1039 	/*
1040 	 * Do not trust the local APIC being empty at bootup.
1041 	 */
1042 	clear_local_APIC();
1043 
1044 	/*
1045 	 * Enable APIC.
1046 	 */
1047 	value = apic_read(APIC_SPIV);
1048 	value &= ~APIC_VECTOR_MASK;
1049 	value |= APIC_SPIV_APIC_ENABLED;
1050 
1051 #ifdef CONFIG_X86_32
1052 	/* This bit is reserved on P4/Xeon and should be cleared */
1053 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1054 	    (boot_cpu_data.x86 == 15))
1055 		value &= ~APIC_SPIV_FOCUS_DISABLED;
1056 	else
1057 #endif
1058 		value |= APIC_SPIV_FOCUS_DISABLED;
1059 	value |= SPURIOUS_APIC_VECTOR;
1060 	apic_write(APIC_SPIV, value);
1061 
1062 	/*
1063 	 * Set up the virtual wire mode.
1064 	 */
1065 	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1066 	value = APIC_DM_NMI;
1067 	if (!lapic_is_integrated())		/* 82489DX */
1068 		value |= APIC_LVT_LEVEL_TRIGGER;
1069 	apic_write(APIC_LVT1, value);
1070 }
1071 
1072 static void __cpuinit lapic_setup_esr(void)
1073 {
1074 	unsigned int oldvalue, value, maxlvt;
1075 
1076 	if (!lapic_is_integrated()) {
1077 		pr_info("No ESR for 82489DX.\n");
1078 		return;
1079 	}
1080 
1081 	if (apic->disable_esr) {
1082 		/*
1083 		 * Something untraceable is creating bad interrupts on
1084 		 * secondary quads ... for the moment, just leave the
1085 		 * ESR disabled - we can't do anything useful with the
1086 		 * errors anyway - mbligh
1087 		 */
1088 		pr_info("Leaving ESR disabled.\n");
1089 		return;
1090 	}
1091 
1092 	maxlvt = lapic_get_maxlvt();
1093 	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1094 		apic_write(APIC_ESR, 0);
1095 	oldvalue = apic_read(APIC_ESR);
1096 
1097 	/* enables sending errors */
1098 	value = ERROR_APIC_VECTOR;
1099 	apic_write(APIC_LVTERR, value);
1100 
1101 	/*
1102 	 * spec says clear errors after enabling vector.
1103 	 */
1104 	if (maxlvt > 3)
1105 		apic_write(APIC_ESR, 0);
1106 	value = apic_read(APIC_ESR);
1107 	if (value != oldvalue)
1108 		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1109 			"vector: 0x%08x  after: 0x%08x\n",
1110 			oldvalue, value);
1111 }
1112 
1113 
1114 /**
1115  * setup_local_APIC - setup the local APIC
1116  */
1117 void __cpuinit setup_local_APIC(void)
1118 {
1119 	unsigned int value;
1120 	int i, j;
1121 
1122 	if (disable_apic) {
1123 		arch_disable_smp_support();
1124 		return;
1125 	}
1126 
1127 #ifdef CONFIG_X86_32
1128 	/* Pound the ESR really hard over the head with a big hammer - mbligh */
1129 	if (lapic_is_integrated() && apic->disable_esr) {
1130 		apic_write(APIC_ESR, 0);
1131 		apic_write(APIC_ESR, 0);
1132 		apic_write(APIC_ESR, 0);
1133 		apic_write(APIC_ESR, 0);
1134 	}
1135 #endif
1136 
1137 	preempt_disable();
1138 
1139 	/*
1140 	 * Double-check whether this APIC is really registered.
1141 	 * This is meaningless in clustered apic mode, so we skip it.
1142 	 */
1143 	if (!apic->apic_id_registered())
1144 		BUG();
1145 
1146 	/*
1147 	 * Intel recommends to set DFR, LDR and TPR before enabling
1148 	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
1149 	 * document number 292116).  So here it goes...
1150 	 */
1151 	apic->init_apic_ldr();
1152 
1153 	/*
1154 	 * Set Task Priority to 'accept all'. We never change this
1155 	 * later on.
1156 	 */
1157 	value = apic_read(APIC_TASKPRI);
1158 	value &= ~APIC_TPRI_MASK;
1159 	apic_write(APIC_TASKPRI, value);
1160 
1161 	/*
1162 	 * After a crash, we no longer service the interrupts and a pending
1163 	 * interrupt from previous kernel might still have ISR bit set.
1164 	 *
1165 	 * Most probably by now CPU has serviced that pending interrupt and
1166 	 * it might not have done the ack_APIC_irq() because it thought,
1167 	 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1168 	 * does not clear the ISR bit and cpu thinks it has already serivced
1169 	 * the interrupt. Hence a vector might get locked. It was noticed
1170 	 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1171 	 */
1172 	for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1173 		value = apic_read(APIC_ISR + i*0x10);
1174 		for (j = 31; j >= 0; j--) {
1175 			if (value & (1<<j))
1176 				ack_APIC_irq();
1177 		}
1178 	}
1179 
1180 	/*
1181 	 * Now that we are all set up, enable the APIC
1182 	 */
1183 	value = apic_read(APIC_SPIV);
1184 	value &= ~APIC_VECTOR_MASK;
1185 	/*
1186 	 * Enable APIC
1187 	 */
1188 	value |= APIC_SPIV_APIC_ENABLED;
1189 
1190 #ifdef CONFIG_X86_32
1191 	/*
1192 	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1193 	 * certain networking cards. If high frequency interrupts are
1194 	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1195 	 * entry is masked/unmasked at a high rate as well then sooner or
1196 	 * later IOAPIC line gets 'stuck', no more interrupts are received
1197 	 * from the device. If focus CPU is disabled then the hang goes
1198 	 * away, oh well :-(
1199 	 *
1200 	 * [ This bug can be reproduced easily with a level-triggered
1201 	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1202 	 *   BX chipset. ]
1203 	 */
1204 	/*
1205 	 * Actually disabling the focus CPU check just makes the hang less
1206 	 * frequent as it makes the interrupt distributon model be more
1207 	 * like LRU than MRU (the short-term load is more even across CPUs).
1208 	 * See also the comment in end_level_ioapic_irq().  --macro
1209 	 */
1210 
1211 	/*
1212 	 * - enable focus processor (bit==0)
1213 	 * - 64bit mode always use processor focus
1214 	 *   so no need to set it
1215 	 */
1216 	value &= ~APIC_SPIV_FOCUS_DISABLED;
1217 #endif
1218 
1219 	/*
1220 	 * Set spurious IRQ vector
1221 	 */
1222 	value |= SPURIOUS_APIC_VECTOR;
1223 	apic_write(APIC_SPIV, value);
1224 
1225 	/*
1226 	 * Set up LVT0, LVT1:
1227 	 *
1228 	 * set up through-local-APIC on the BP's LINT0. This is not
1229 	 * strictly necessary in pure symmetric-IO mode, but sometimes
1230 	 * we delegate interrupts to the 8259A.
1231 	 */
1232 	/*
1233 	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1234 	 */
1235 	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1236 	if (!smp_processor_id() && (pic_mode || !value)) {
1237 		value = APIC_DM_EXTINT;
1238 		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n",
1239 				smp_processor_id());
1240 	} else {
1241 		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1242 		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n",
1243 				smp_processor_id());
1244 	}
1245 	apic_write(APIC_LVT0, value);
1246 
1247 	/*
1248 	 * only the BP should see the LINT1 NMI signal, obviously.
1249 	 */
1250 	if (!smp_processor_id())
1251 		value = APIC_DM_NMI;
1252 	else
1253 		value = APIC_DM_NMI | APIC_LVT_MASKED;
1254 	if (!lapic_is_integrated())		/* 82489DX */
1255 		value |= APIC_LVT_LEVEL_TRIGGER;
1256 	apic_write(APIC_LVT1, value);
1257 
1258 	preempt_enable();
1259 
1260 #ifdef CONFIG_X86_MCE_INTEL
1261 	/* Recheck CMCI information after local APIC is up on CPU #0 */
1262 	if (smp_processor_id() == 0)
1263 		cmci_recheck();
1264 #endif
1265 }
1266 
1267 void __cpuinit end_local_APIC_setup(void)
1268 {
1269 	lapic_setup_esr();
1270 
1271 #ifdef CONFIG_X86_32
1272 	{
1273 		unsigned int value;
1274 		/* Disable the local apic timer */
1275 		value = apic_read(APIC_LVTT);
1276 		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1277 		apic_write(APIC_LVTT, value);
1278 	}
1279 #endif
1280 
1281 	setup_apic_nmi_watchdog(NULL);
1282 	apic_pm_activate();
1283 }
1284 
1285 #ifdef CONFIG_X86_X2APIC
1286 void check_x2apic(void)
1287 {
1288 	if (x2apic_enabled()) {
1289 		pr_info("x2apic enabled by BIOS, switching to x2apic ops\n");
1290 		x2apic_preenabled = x2apic = 1;
1291 	}
1292 }
1293 
1294 void enable_x2apic(void)
1295 {
1296 	int msr, msr2;
1297 
1298 	if (!x2apic)
1299 		return;
1300 
1301 	rdmsr(MSR_IA32_APICBASE, msr, msr2);
1302 	if (!(msr & X2APIC_ENABLE)) {
1303 		pr_info("Enabling x2apic\n");
1304 		wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, 0);
1305 	}
1306 }
1307 
1308 void __init enable_IR_x2apic(void)
1309 {
1310 #ifdef CONFIG_INTR_REMAP
1311 	int ret;
1312 	unsigned long flags;
1313 	struct IO_APIC_route_entry **ioapic_entries = NULL;
1314 
1315 	if (!cpu_has_x2apic)
1316 		return;
1317 
1318 	if (!x2apic_preenabled && disable_x2apic) {
1319 		pr_info("Skipped enabling x2apic and Interrupt-remapping "
1320 			"because of nox2apic\n");
1321 		return;
1322 	}
1323 
1324 	if (x2apic_preenabled && disable_x2apic)
1325 		panic("Bios already enabled x2apic, can't enforce nox2apic");
1326 
1327 	if (!x2apic_preenabled && skip_ioapic_setup) {
1328 		pr_info("Skipped enabling x2apic and Interrupt-remapping "
1329 			"because of skipping io-apic setup\n");
1330 		return;
1331 	}
1332 
1333 	ret = dmar_table_init();
1334 	if (ret) {
1335 		pr_info("dmar_table_init() failed with %d:\n", ret);
1336 
1337 		if (x2apic_preenabled)
1338 			panic("x2apic enabled by bios. But IR enabling failed");
1339 		else
1340 			pr_info("Not enabling x2apic,Intr-remapping\n");
1341 		return;
1342 	}
1343 
1344 	ioapic_entries = alloc_ioapic_entries();
1345 	if (!ioapic_entries) {
1346 		pr_info("Allocate ioapic_entries failed: %d\n", ret);
1347 		goto end;
1348 	}
1349 
1350 	ret = save_IO_APIC_setup(ioapic_entries);
1351 	if (ret) {
1352 		pr_info("Saving IO-APIC state failed: %d\n", ret);
1353 		goto end;
1354 	}
1355 
1356 	local_irq_save(flags);
1357 	mask_IO_APIC_setup(ioapic_entries);
1358 	mask_8259A();
1359 
1360 	ret = enable_intr_remapping(EIM_32BIT_APIC_ID);
1361 
1362 	if (ret && x2apic_preenabled) {
1363 		local_irq_restore(flags);
1364 		panic("x2apic enabled by bios. But IR enabling failed");
1365 	}
1366 
1367 	if (ret)
1368 		goto end_restore;
1369 
1370 	if (!x2apic) {
1371 		x2apic = 1;
1372 		enable_x2apic();
1373 	}
1374 
1375 end_restore:
1376 	if (ret)
1377 		/*
1378 		 * IR enabling failed
1379 		 */
1380 		restore_IO_APIC_setup(ioapic_entries);
1381 	else
1382 		reinit_intr_remapped_IO_APIC(x2apic_preenabled, ioapic_entries);
1383 
1384 	unmask_8259A();
1385 	local_irq_restore(flags);
1386 
1387 end:
1388 	if (!ret) {
1389 		if (!x2apic_preenabled)
1390 			pr_info("Enabled x2apic and interrupt-remapping\n");
1391 		else
1392 			pr_info("Enabled Interrupt-remapping\n");
1393 	} else
1394 		pr_err("Failed to enable Interrupt-remapping and x2apic\n");
1395 	if (ioapic_entries)
1396 		free_ioapic_entries(ioapic_entries);
1397 #else
1398 	if (!cpu_has_x2apic)
1399 		return;
1400 
1401 	if (x2apic_preenabled)
1402 		panic("x2apic enabled prior OS handover,"
1403 		      " enable CONFIG_INTR_REMAP");
1404 
1405 	pr_info("Enable CONFIG_INTR_REMAP for enabling intr-remapping "
1406 		" and x2apic\n");
1407 #endif
1408 
1409 	return;
1410 }
1411 #endif /* CONFIG_X86_X2APIC */
1412 
1413 #ifdef CONFIG_X86_64
1414 /*
1415  * Detect and enable local APICs on non-SMP boards.
1416  * Original code written by Keir Fraser.
1417  * On AMD64 we trust the BIOS - if it says no APIC it is likely
1418  * not correctly set up (usually the APIC timer won't work etc.)
1419  */
1420 static int __init detect_init_APIC(void)
1421 {
1422 	if (!cpu_has_apic) {
1423 		pr_info("No local APIC present\n");
1424 		return -1;
1425 	}
1426 
1427 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1428 	boot_cpu_physical_apicid = 0;
1429 	return 0;
1430 }
1431 #else
1432 /*
1433  * Detect and initialize APIC
1434  */
1435 static int __init detect_init_APIC(void)
1436 {
1437 	u32 h, l, features;
1438 
1439 	/* Disabled by kernel option? */
1440 	if (disable_apic)
1441 		return -1;
1442 
1443 	switch (boot_cpu_data.x86_vendor) {
1444 	case X86_VENDOR_AMD:
1445 		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1446 		    (boot_cpu_data.x86 >= 15))
1447 			break;
1448 		goto no_apic;
1449 	case X86_VENDOR_INTEL:
1450 		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1451 		    (boot_cpu_data.x86 == 5 && cpu_has_apic))
1452 			break;
1453 		goto no_apic;
1454 	default:
1455 		goto no_apic;
1456 	}
1457 
1458 	if (!cpu_has_apic) {
1459 		/*
1460 		 * Over-ride BIOS and try to enable the local APIC only if
1461 		 * "lapic" specified.
1462 		 */
1463 		if (!force_enable_local_apic) {
1464 			pr_info("Local APIC disabled by BIOS -- "
1465 				"you can enable it with \"lapic\"\n");
1466 			return -1;
1467 		}
1468 		/*
1469 		 * Some BIOSes disable the local APIC in the APIC_BASE
1470 		 * MSR. This can only be done in software for Intel P6 or later
1471 		 * and AMD K7 (Model > 1) or later.
1472 		 */
1473 		rdmsr(MSR_IA32_APICBASE, l, h);
1474 		if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1475 			pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1476 			l &= ~MSR_IA32_APICBASE_BASE;
1477 			l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE;
1478 			wrmsr(MSR_IA32_APICBASE, l, h);
1479 			enabled_via_apicbase = 1;
1480 		}
1481 	}
1482 	/*
1483 	 * The APIC feature bit should now be enabled
1484 	 * in `cpuid'
1485 	 */
1486 	features = cpuid_edx(1);
1487 	if (!(features & (1 << X86_FEATURE_APIC))) {
1488 		pr_warning("Could not enable APIC!\n");
1489 		return -1;
1490 	}
1491 	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1492 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1493 
1494 	/* The BIOS may have set up the APIC at some other address */
1495 	rdmsr(MSR_IA32_APICBASE, l, h);
1496 	if (l & MSR_IA32_APICBASE_ENABLE)
1497 		mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1498 
1499 	pr_info("Found and enabled local APIC!\n");
1500 
1501 	apic_pm_activate();
1502 
1503 	return 0;
1504 
1505 no_apic:
1506 	pr_info("No local APIC present or hardware disabled\n");
1507 	return -1;
1508 }
1509 #endif
1510 
1511 #ifdef CONFIG_X86_64
1512 void __init early_init_lapic_mapping(void)
1513 {
1514 	unsigned long phys_addr;
1515 
1516 	/*
1517 	 * If no local APIC can be found then go out
1518 	 * : it means there is no mpatable and MADT
1519 	 */
1520 	if (!smp_found_config)
1521 		return;
1522 
1523 	phys_addr = mp_lapic_addr;
1524 
1525 	set_fixmap_nocache(FIX_APIC_BASE, phys_addr);
1526 	apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
1527 		    APIC_BASE, phys_addr);
1528 
1529 	/*
1530 	 * Fetch the APIC ID of the BSP in case we have a
1531 	 * default configuration (or the MP table is broken).
1532 	 */
1533 	boot_cpu_physical_apicid = read_apic_id();
1534 }
1535 #endif
1536 
1537 /**
1538  * init_apic_mappings - initialize APIC mappings
1539  */
1540 void __init init_apic_mappings(void)
1541 {
1542 	if (x2apic) {
1543 		boot_cpu_physical_apicid = read_apic_id();
1544 		return;
1545 	}
1546 
1547 	/*
1548 	 * If no local APIC can be found then set up a fake all
1549 	 * zeroes page to simulate the local APIC and another
1550 	 * one for the IO-APIC.
1551 	 */
1552 	if (!smp_found_config && detect_init_APIC()) {
1553 		apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
1554 		apic_phys = __pa(apic_phys);
1555 	} else
1556 		apic_phys = mp_lapic_addr;
1557 
1558 	set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
1559 	apic_printk(APIC_VERBOSE, "mapped APIC to %08lx (%08lx)\n",
1560 				APIC_BASE, apic_phys);
1561 
1562 	/*
1563 	 * Fetch the APIC ID of the BSP in case we have a
1564 	 * default configuration (or the MP table is broken).
1565 	 */
1566 	if (boot_cpu_physical_apicid == -1U)
1567 		boot_cpu_physical_apicid = read_apic_id();
1568 }
1569 
1570 /*
1571  * This initializes the IO-APIC and APIC hardware if this is
1572  * a UP kernel.
1573  */
1574 int apic_version[MAX_APICS];
1575 
1576 int __init APIC_init_uniprocessor(void)
1577 {
1578 	if (disable_apic) {
1579 		pr_info("Apic disabled\n");
1580 		return -1;
1581 	}
1582 #ifdef CONFIG_X86_64
1583 	if (!cpu_has_apic) {
1584 		disable_apic = 1;
1585 		pr_info("Apic disabled by BIOS\n");
1586 		return -1;
1587 	}
1588 #else
1589 	if (!smp_found_config && !cpu_has_apic)
1590 		return -1;
1591 
1592 	/*
1593 	 * Complain if the BIOS pretends there is one.
1594 	 */
1595 	if (!cpu_has_apic &&
1596 	    APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
1597 		pr_err("BIOS bug, local APIC 0x%x not detected!...\n",
1598 			boot_cpu_physical_apicid);
1599 		clear_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1600 		return -1;
1601 	}
1602 #endif
1603 
1604 	enable_IR_x2apic();
1605 #ifdef CONFIG_X86_64
1606 	default_setup_apic_routing();
1607 #endif
1608 
1609 	verify_local_APIC();
1610 	connect_bsp_APIC();
1611 
1612 #ifdef CONFIG_X86_64
1613 	apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
1614 #else
1615 	/*
1616 	 * Hack: In case of kdump, after a crash, kernel might be booting
1617 	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
1618 	 * might be zero if read from MP tables. Get it from LAPIC.
1619 	 */
1620 # ifdef CONFIG_CRASH_DUMP
1621 	boot_cpu_physical_apicid = read_apic_id();
1622 # endif
1623 #endif
1624 	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
1625 	setup_local_APIC();
1626 
1627 #ifdef CONFIG_X86_IO_APIC
1628 	/*
1629 	 * Now enable IO-APICs, actually call clear_IO_APIC
1630 	 * We need clear_IO_APIC before enabling error vector
1631 	 */
1632 	if (!skip_ioapic_setup && nr_ioapics)
1633 		enable_IO_APIC();
1634 #endif
1635 
1636 	end_local_APIC_setup();
1637 
1638 #ifdef CONFIG_X86_IO_APIC
1639 	if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1640 		setup_IO_APIC();
1641 	else {
1642 		nr_ioapics = 0;
1643 		localise_nmi_watchdog();
1644 	}
1645 #else
1646 	localise_nmi_watchdog();
1647 #endif
1648 
1649 	setup_boot_clock();
1650 #ifdef CONFIG_X86_64
1651 	check_nmi_watchdog();
1652 #endif
1653 
1654 	return 0;
1655 }
1656 
1657 /*
1658  * Local APIC interrupts
1659  */
1660 
1661 /*
1662  * This interrupt should _never_ happen with our APIC/SMP architecture
1663  */
1664 void smp_spurious_interrupt(struct pt_regs *regs)
1665 {
1666 	u32 v;
1667 
1668 	exit_idle();
1669 	irq_enter();
1670 	/*
1671 	 * Check if this really is a spurious interrupt and ACK it
1672 	 * if it is a vectored one.  Just in case...
1673 	 * Spurious interrupts should not be ACKed.
1674 	 */
1675 	v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1676 	if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1677 		ack_APIC_irq();
1678 
1679 	inc_irq_stat(irq_spurious_count);
1680 
1681 	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
1682 	pr_info("spurious APIC interrupt on CPU#%d, "
1683 		"should never happen.\n", smp_processor_id());
1684 	irq_exit();
1685 }
1686 
1687 /*
1688  * This interrupt should never happen with our APIC/SMP architecture
1689  */
1690 void smp_error_interrupt(struct pt_regs *regs)
1691 {
1692 	u32 v, v1;
1693 
1694 	exit_idle();
1695 	irq_enter();
1696 	/* First tickle the hardware, only then report what went on. -- REW */
1697 	v = apic_read(APIC_ESR);
1698 	apic_write(APIC_ESR, 0);
1699 	v1 = apic_read(APIC_ESR);
1700 	ack_APIC_irq();
1701 	atomic_inc(&irq_err_count);
1702 
1703 	/*
1704 	 * Here is what the APIC error bits mean:
1705 	 * 0: Send CS error
1706 	 * 1: Receive CS error
1707 	 * 2: Send accept error
1708 	 * 3: Receive accept error
1709 	 * 4: Reserved
1710 	 * 5: Send illegal vector
1711 	 * 6: Received illegal vector
1712 	 * 7: Illegal register address
1713 	 */
1714 	pr_debug("APIC error on CPU%d: %02x(%02x)\n",
1715 		smp_processor_id(), v , v1);
1716 	irq_exit();
1717 }
1718 
1719 /**
1720  * connect_bsp_APIC - attach the APIC to the interrupt system
1721  */
1722 void __init connect_bsp_APIC(void)
1723 {
1724 #ifdef CONFIG_X86_32
1725 	if (pic_mode) {
1726 		/*
1727 		 * Do not trust the local APIC being empty at bootup.
1728 		 */
1729 		clear_local_APIC();
1730 		/*
1731 		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
1732 		 * local APIC to INT and NMI lines.
1733 		 */
1734 		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
1735 				"enabling APIC mode.\n");
1736 		outb(0x70, 0x22);
1737 		outb(0x01, 0x23);
1738 	}
1739 #endif
1740 	if (apic->enable_apic_mode)
1741 		apic->enable_apic_mode();
1742 }
1743 
1744 /**
1745  * disconnect_bsp_APIC - detach the APIC from the interrupt system
1746  * @virt_wire_setup:	indicates, whether virtual wire mode is selected
1747  *
1748  * Virtual wire mode is necessary to deliver legacy interrupts even when the
1749  * APIC is disabled.
1750  */
1751 void disconnect_bsp_APIC(int virt_wire_setup)
1752 {
1753 	unsigned int value;
1754 
1755 #ifdef CONFIG_X86_32
1756 	if (pic_mode) {
1757 		/*
1758 		 * Put the board back into PIC mode (has an effect only on
1759 		 * certain older boards).  Note that APIC interrupts, including
1760 		 * IPIs, won't work beyond this point!  The only exception are
1761 		 * INIT IPIs.
1762 		 */
1763 		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
1764 				"entering PIC mode.\n");
1765 		outb(0x70, 0x22);
1766 		outb(0x00, 0x23);
1767 		return;
1768 	}
1769 #endif
1770 
1771 	/* Go back to Virtual Wire compatibility mode */
1772 
1773 	/* For the spurious interrupt use vector F, and enable it */
1774 	value = apic_read(APIC_SPIV);
1775 	value &= ~APIC_VECTOR_MASK;
1776 	value |= APIC_SPIV_APIC_ENABLED;
1777 	value |= 0xf;
1778 	apic_write(APIC_SPIV, value);
1779 
1780 	if (!virt_wire_setup) {
1781 		/*
1782 		 * For LVT0 make it edge triggered, active high,
1783 		 * external and enabled
1784 		 */
1785 		value = apic_read(APIC_LVT0);
1786 		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1787 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1788 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1789 		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1790 		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1791 		apic_write(APIC_LVT0, value);
1792 	} else {
1793 		/* Disable LVT0 */
1794 		apic_write(APIC_LVT0, APIC_LVT_MASKED);
1795 	}
1796 
1797 	/*
1798 	 * For LVT1 make it edge triggered, active high,
1799 	 * nmi and enabled
1800 	 */
1801 	value = apic_read(APIC_LVT1);
1802 	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1803 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1804 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1805 	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1806 	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1807 	apic_write(APIC_LVT1, value);
1808 }
1809 
1810 void __cpuinit generic_processor_info(int apicid, int version)
1811 {
1812 	int cpu;
1813 
1814 	/*
1815 	 * Validate version
1816 	 */
1817 	if (version == 0x0) {
1818 		pr_warning("BIOS bug, APIC version is 0 for CPU#%d! "
1819 			   "fixing up to 0x10. (tell your hw vendor)\n",
1820 				version);
1821 		version = 0x10;
1822 	}
1823 	apic_version[apicid] = version;
1824 
1825 	if (num_processors >= nr_cpu_ids) {
1826 		int max = nr_cpu_ids;
1827 		int thiscpu = max + disabled_cpus;
1828 
1829 		pr_warning(
1830 			"ACPI: NR_CPUS/possible_cpus limit of %i reached."
1831 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
1832 
1833 		disabled_cpus++;
1834 		return;
1835 	}
1836 
1837 	num_processors++;
1838 	cpu = cpumask_next_zero(-1, cpu_present_mask);
1839 
1840 	if (version != apic_version[boot_cpu_physical_apicid])
1841 		WARN_ONCE(1,
1842 			"ACPI: apic version mismatch, bootcpu: %x cpu %d: %x\n",
1843 			apic_version[boot_cpu_physical_apicid], cpu, version);
1844 
1845 	physid_set(apicid, phys_cpu_present_map);
1846 	if (apicid == boot_cpu_physical_apicid) {
1847 		/*
1848 		 * x86_bios_cpu_apicid is required to have processors listed
1849 		 * in same order as logical cpu numbers. Hence the first
1850 		 * entry is BSP, and so on.
1851 		 */
1852 		cpu = 0;
1853 	}
1854 	if (apicid > max_physical_apicid)
1855 		max_physical_apicid = apicid;
1856 
1857 #ifdef CONFIG_X86_32
1858 	/*
1859 	 * Would be preferable to switch to bigsmp when CONFIG_HOTPLUG_CPU=y
1860 	 * but we need to work other dependencies like SMP_SUSPEND etc
1861 	 * before this can be done without some confusion.
1862 	 * if (CPU_HOTPLUG_ENABLED || num_processors > 8)
1863 	 *       - Ashok Raj <ashok.raj@intel.com>
1864 	 */
1865 	if (max_physical_apicid >= 8) {
1866 		switch (boot_cpu_data.x86_vendor) {
1867 		case X86_VENDOR_INTEL:
1868 			if (!APIC_XAPIC(version)) {
1869 				def_to_bigsmp = 0;
1870 				break;
1871 			}
1872 			/* If P4 and above fall through */
1873 		case X86_VENDOR_AMD:
1874 			def_to_bigsmp = 1;
1875 		}
1876 	}
1877 #endif
1878 
1879 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
1880 	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
1881 	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
1882 #endif
1883 
1884 	set_cpu_possible(cpu, true);
1885 	set_cpu_present(cpu, true);
1886 }
1887 
1888 int hard_smp_processor_id(void)
1889 {
1890 	return read_apic_id();
1891 }
1892 
1893 void default_init_apic_ldr(void)
1894 {
1895 	unsigned long val;
1896 
1897 	apic_write(APIC_DFR, APIC_DFR_VALUE);
1898 	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
1899 	val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
1900 	apic_write(APIC_LDR, val);
1901 }
1902 
1903 #ifdef CONFIG_X86_32
1904 int default_apicid_to_node(int logical_apicid)
1905 {
1906 #ifdef CONFIG_SMP
1907 	return apicid_2_node[hard_smp_processor_id()];
1908 #else
1909 	return 0;
1910 #endif
1911 }
1912 #endif
1913 
1914 /*
1915  * Power management
1916  */
1917 #ifdef CONFIG_PM
1918 
1919 static struct {
1920 	/*
1921 	 * 'active' is true if the local APIC was enabled by us and
1922 	 * not the BIOS; this signifies that we are also responsible
1923 	 * for disabling it before entering apm/acpi suspend
1924 	 */
1925 	int active;
1926 	/* r/w apic fields */
1927 	unsigned int apic_id;
1928 	unsigned int apic_taskpri;
1929 	unsigned int apic_ldr;
1930 	unsigned int apic_dfr;
1931 	unsigned int apic_spiv;
1932 	unsigned int apic_lvtt;
1933 	unsigned int apic_lvtpc;
1934 	unsigned int apic_lvt0;
1935 	unsigned int apic_lvt1;
1936 	unsigned int apic_lvterr;
1937 	unsigned int apic_tmict;
1938 	unsigned int apic_tdcr;
1939 	unsigned int apic_thmr;
1940 } apic_pm_state;
1941 
1942 static int lapic_suspend(struct sys_device *dev, pm_message_t state)
1943 {
1944 	unsigned long flags;
1945 	int maxlvt;
1946 
1947 	if (!apic_pm_state.active)
1948 		return 0;
1949 
1950 	maxlvt = lapic_get_maxlvt();
1951 
1952 	apic_pm_state.apic_id = apic_read(APIC_ID);
1953 	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
1954 	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
1955 	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
1956 	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
1957 	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
1958 	if (maxlvt >= 4)
1959 		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
1960 	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
1961 	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
1962 	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
1963 	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
1964 	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
1965 #if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
1966 	if (maxlvt >= 5)
1967 		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
1968 #endif
1969 
1970 	local_irq_save(flags);
1971 	disable_local_APIC();
1972 #ifdef CONFIG_INTR_REMAP
1973 	if (intr_remapping_enabled)
1974 		disable_intr_remapping();
1975 #endif
1976 	local_irq_restore(flags);
1977 	return 0;
1978 }
1979 
1980 static int lapic_resume(struct sys_device *dev)
1981 {
1982 	unsigned int l, h;
1983 	unsigned long flags;
1984 	int maxlvt;
1985 
1986 #ifdef CONFIG_INTR_REMAP
1987 	int ret;
1988 	struct IO_APIC_route_entry **ioapic_entries = NULL;
1989 
1990 	if (!apic_pm_state.active)
1991 		return 0;
1992 
1993 	local_irq_save(flags);
1994 	if (x2apic) {
1995 		ioapic_entries = alloc_ioapic_entries();
1996 		if (!ioapic_entries) {
1997 			WARN(1, "Alloc ioapic_entries in lapic resume failed.");
1998 			return -ENOMEM;
1999 		}
2000 
2001 		ret = save_IO_APIC_setup(ioapic_entries);
2002 		if (ret) {
2003 			WARN(1, "Saving IO-APIC state failed: %d\n", ret);
2004 			free_ioapic_entries(ioapic_entries);
2005 			return ret;
2006 		}
2007 
2008 		mask_IO_APIC_setup(ioapic_entries);
2009 		mask_8259A();
2010 		enable_x2apic();
2011 	}
2012 #else
2013 	if (!apic_pm_state.active)
2014 		return 0;
2015 
2016 	local_irq_save(flags);
2017 	if (x2apic)
2018 		enable_x2apic();
2019 #endif
2020 
2021 	else {
2022 		/*
2023 		 * Make sure the APICBASE points to the right address
2024 		 *
2025 		 * FIXME! This will be wrong if we ever support suspend on
2026 		 * SMP! We'll need to do this as part of the CPU restore!
2027 		 */
2028 		rdmsr(MSR_IA32_APICBASE, l, h);
2029 		l &= ~MSR_IA32_APICBASE_BASE;
2030 		l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2031 		wrmsr(MSR_IA32_APICBASE, l, h);
2032 	}
2033 
2034 	maxlvt = lapic_get_maxlvt();
2035 	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2036 	apic_write(APIC_ID, apic_pm_state.apic_id);
2037 	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2038 	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2039 	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2040 	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2041 	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2042 	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2043 #if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
2044 	if (maxlvt >= 5)
2045 		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2046 #endif
2047 	if (maxlvt >= 4)
2048 		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2049 	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2050 	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2051 	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2052 	apic_write(APIC_ESR, 0);
2053 	apic_read(APIC_ESR);
2054 	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2055 	apic_write(APIC_ESR, 0);
2056 	apic_read(APIC_ESR);
2057 
2058 #ifdef CONFIG_INTR_REMAP
2059 	if (intr_remapping_enabled)
2060 		reenable_intr_remapping(EIM_32BIT_APIC_ID);
2061 
2062 	if (x2apic) {
2063 		unmask_8259A();
2064 		restore_IO_APIC_setup(ioapic_entries);
2065 		free_ioapic_entries(ioapic_entries);
2066 	}
2067 #endif
2068 
2069 	local_irq_restore(flags);
2070 
2071 
2072 	return 0;
2073 }
2074 
2075 /*
2076  * This device has no shutdown method - fully functioning local APICs
2077  * are needed on every CPU up until machine_halt/restart/poweroff.
2078  */
2079 
2080 static struct sysdev_class lapic_sysclass = {
2081 	.name		= "lapic",
2082 	.resume		= lapic_resume,
2083 	.suspend	= lapic_suspend,
2084 };
2085 
2086 static struct sys_device device_lapic = {
2087 	.id	= 0,
2088 	.cls	= &lapic_sysclass,
2089 };
2090 
2091 static void __cpuinit apic_pm_activate(void)
2092 {
2093 	apic_pm_state.active = 1;
2094 }
2095 
2096 static int __init init_lapic_sysfs(void)
2097 {
2098 	int error;
2099 
2100 	if (!cpu_has_apic)
2101 		return 0;
2102 	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2103 
2104 	error = sysdev_class_register(&lapic_sysclass);
2105 	if (!error)
2106 		error = sysdev_register(&device_lapic);
2107 	return error;
2108 }
2109 
2110 /* local apic needs to resume before other devices access its registers. */
2111 core_initcall(init_lapic_sysfs);
2112 
2113 #else	/* CONFIG_PM */
2114 
2115 static void apic_pm_activate(void) { }
2116 
2117 #endif	/* CONFIG_PM */
2118 
2119 #ifdef CONFIG_X86_64
2120 /*
2121  * apic_is_clustered_box() -- Check if we can expect good TSC
2122  *
2123  * Thus far, the major user of this is IBM's Summit2 series:
2124  *
2125  * Clustered boxes may have unsynced TSC problems if they are
2126  * multi-chassis. Use available data to take a good guess.
2127  * If in doubt, go HPET.
2128  */
2129 __cpuinit int apic_is_clustered_box(void)
2130 {
2131 	int i, clusters, zeros;
2132 	unsigned id;
2133 	u16 *bios_cpu_apicid;
2134 	DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
2135 
2136 	/*
2137 	 * there is not this kind of box with AMD CPU yet.
2138 	 * Some AMD box with quadcore cpu and 8 sockets apicid
2139 	 * will be [4, 0x23] or [8, 0x27] could be thought to
2140 	 * vsmp box still need checking...
2141 	 */
2142 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && !is_vsmp_box())
2143 		return 0;
2144 
2145 	bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
2146 	bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
2147 
2148 	for (i = 0; i < nr_cpu_ids; i++) {
2149 		/* are we being called early in kernel startup? */
2150 		if (bios_cpu_apicid) {
2151 			id = bios_cpu_apicid[i];
2152 		} else if (i < nr_cpu_ids) {
2153 			if (cpu_present(i))
2154 				id = per_cpu(x86_bios_cpu_apicid, i);
2155 			else
2156 				continue;
2157 		} else
2158 			break;
2159 
2160 		if (id != BAD_APICID)
2161 			__set_bit(APIC_CLUSTERID(id), clustermap);
2162 	}
2163 
2164 	/* Problem:  Partially populated chassis may not have CPUs in some of
2165 	 * the APIC clusters they have been allocated.  Only present CPUs have
2166 	 * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap.
2167 	 * Since clusters are allocated sequentially, count zeros only if
2168 	 * they are bounded by ones.
2169 	 */
2170 	clusters = 0;
2171 	zeros = 0;
2172 	for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
2173 		if (test_bit(i, clustermap)) {
2174 			clusters += 1 + zeros;
2175 			zeros = 0;
2176 		} else
2177 			++zeros;
2178 	}
2179 
2180 	/* ScaleMP vSMPowered boxes have one cluster per board and TSCs are
2181 	 * not guaranteed to be synced between boards
2182 	 */
2183 	if (is_vsmp_box() && clusters > 1)
2184 		return 1;
2185 
2186 	/*
2187 	 * If clusters > 2, then should be multi-chassis.
2188 	 * May have to revisit this when multi-core + hyperthreaded CPUs come
2189 	 * out, but AFAIK this will work even for them.
2190 	 */
2191 	return (clusters > 2);
2192 }
2193 #endif
2194 
2195 /*
2196  * APIC command line parameters
2197  */
2198 static int __init setup_disableapic(char *arg)
2199 {
2200 	disable_apic = 1;
2201 	setup_clear_cpu_cap(X86_FEATURE_APIC);
2202 	return 0;
2203 }
2204 early_param("disableapic", setup_disableapic);
2205 
2206 /* same as disableapic, for compatibility */
2207 static int __init setup_nolapic(char *arg)
2208 {
2209 	return setup_disableapic(arg);
2210 }
2211 early_param("nolapic", setup_nolapic);
2212 
2213 static int __init parse_lapic_timer_c2_ok(char *arg)
2214 {
2215 	local_apic_timer_c2_ok = 1;
2216 	return 0;
2217 }
2218 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2219 
2220 static int __init parse_disable_apic_timer(char *arg)
2221 {
2222 	disable_apic_timer = 1;
2223 	return 0;
2224 }
2225 early_param("noapictimer", parse_disable_apic_timer);
2226 
2227 static int __init parse_nolapic_timer(char *arg)
2228 {
2229 	disable_apic_timer = 1;
2230 	return 0;
2231 }
2232 early_param("nolapic_timer", parse_nolapic_timer);
2233 
2234 static int __init apic_set_verbosity(char *arg)
2235 {
2236 	if (!arg)  {
2237 #ifdef CONFIG_X86_64
2238 		skip_ioapic_setup = 0;
2239 		return 0;
2240 #endif
2241 		return -EINVAL;
2242 	}
2243 
2244 	if (strcmp("debug", arg) == 0)
2245 		apic_verbosity = APIC_DEBUG;
2246 	else if (strcmp("verbose", arg) == 0)
2247 		apic_verbosity = APIC_VERBOSE;
2248 	else {
2249 		pr_warning("APIC Verbosity level %s not recognised"
2250 			" use apic=verbose or apic=debug\n", arg);
2251 		return -EINVAL;
2252 	}
2253 
2254 	return 0;
2255 }
2256 early_param("apic", apic_set_verbosity);
2257 
2258 static int __init lapic_insert_resource(void)
2259 {
2260 	if (!apic_phys)
2261 		return -1;
2262 
2263 	/* Put local APIC into the resource map. */
2264 	lapic_resource.start = apic_phys;
2265 	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2266 	insert_resource(&iomem_resource, &lapic_resource);
2267 
2268 	return 0;
2269 }
2270 
2271 /*
2272  * need call insert after e820_reserve_resources()
2273  * that is using request_resource
2274  */
2275 late_initcall(lapic_insert_resource);
2276