xref: /linux/arch/x86/kernel/apic/apic.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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 #include <asm/tsc.h>
55 
56 unsigned int num_processors;
57 
58 unsigned disabled_cpus __cpuinitdata;
59 
60 /* Processor that is doing the boot up */
61 unsigned int boot_cpu_physical_apicid = -1U;
62 
63 /*
64  * The highest APIC ID seen during enumeration.
65  */
66 unsigned int max_physical_apicid;
67 
68 /*
69  * Bitmask of physically existing CPUs:
70  */
71 physid_mask_t phys_cpu_present_map;
72 
73 /*
74  * Map cpu index to physical APIC ID
75  */
76 DEFINE_EARLY_PER_CPU(u16, x86_cpu_to_apicid, BAD_APICID);
77 DEFINE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid, BAD_APICID);
78 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
79 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
80 
81 #ifdef CONFIG_X86_32
82 /*
83  * Knob to control our willingness to enable the local APIC.
84  *
85  * +1=force-enable
86  */
87 static int force_enable_local_apic;
88 /*
89  * APIC command line parameters
90  */
91 static int __init parse_lapic(char *arg)
92 {
93 	force_enable_local_apic = 1;
94 	return 0;
95 }
96 early_param("lapic", parse_lapic);
97 /* Local APIC was disabled by the BIOS and enabled by the kernel */
98 static int enabled_via_apicbase;
99 
100 /*
101  * Handle interrupt mode configuration register (IMCR).
102  * This register controls whether the interrupt signals
103  * that reach the BSP come from the master PIC or from the
104  * local APIC. Before entering Symmetric I/O Mode, either
105  * the BIOS or the operating system must switch out of
106  * PIC Mode by changing the IMCR.
107  */
108 static inline void imcr_pic_to_apic(void)
109 {
110 	/* select IMCR register */
111 	outb(0x70, 0x22);
112 	/* NMI and 8259 INTR go through APIC */
113 	outb(0x01, 0x23);
114 }
115 
116 static inline void imcr_apic_to_pic(void)
117 {
118 	/* select IMCR register */
119 	outb(0x70, 0x22);
120 	/* NMI and 8259 INTR go directly to BSP */
121 	outb(0x00, 0x23);
122 }
123 #endif
124 
125 #ifdef CONFIG_X86_64
126 static int apic_calibrate_pmtmr __initdata;
127 static __init int setup_apicpmtimer(char *s)
128 {
129 	apic_calibrate_pmtmr = 1;
130 	notsc_setup(NULL);
131 	return 0;
132 }
133 __setup("apicpmtimer", setup_apicpmtimer);
134 #endif
135 
136 int x2apic_mode;
137 #ifdef CONFIG_X86_X2APIC
138 /* x2apic enabled before OS handover */
139 static int x2apic_preenabled;
140 static __init int setup_nox2apic(char *str)
141 {
142 	if (x2apic_enabled()) {
143 		pr_warning("Bios already enabled x2apic, "
144 			   "can't enforce nox2apic");
145 		return 0;
146 	}
147 
148 	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
149 	return 0;
150 }
151 early_param("nox2apic", setup_nox2apic);
152 #endif
153 
154 unsigned long mp_lapic_addr;
155 int disable_apic;
156 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
157 static int disable_apic_timer __cpuinitdata;
158 /* Local APIC timer works in C2 */
159 int local_apic_timer_c2_ok;
160 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
161 
162 int first_system_vector = 0xfe;
163 
164 /*
165  * Debug level, exported for io_apic.c
166  */
167 unsigned int apic_verbosity;
168 
169 int pic_mode;
170 
171 /* Have we found an MP table */
172 int smp_found_config;
173 
174 static struct resource lapic_resource = {
175 	.name = "Local APIC",
176 	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
177 };
178 
179 static unsigned int calibration_result;
180 
181 static int lapic_next_event(unsigned long delta,
182 			    struct clock_event_device *evt);
183 static void lapic_timer_setup(enum clock_event_mode mode,
184 			      struct clock_event_device *evt);
185 static void lapic_timer_broadcast(const struct cpumask *mask);
186 static void apic_pm_activate(void);
187 
188 /*
189  * The local apic timer can be used for any function which is CPU local.
190  */
191 static struct clock_event_device lapic_clockevent = {
192 	.name		= "lapic",
193 	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
194 			| CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
195 	.shift		= 32,
196 	.set_mode	= lapic_timer_setup,
197 	.set_next_event	= lapic_next_event,
198 	.broadcast	= lapic_timer_broadcast,
199 	.rating		= 100,
200 	.irq		= -1,
201 };
202 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
203 
204 static unsigned long apic_phys;
205 
206 /*
207  * Get the LAPIC version
208  */
209 static inline int lapic_get_version(void)
210 {
211 	return GET_APIC_VERSION(apic_read(APIC_LVR));
212 }
213 
214 /*
215  * Check, if the APIC is integrated or a separate chip
216  */
217 static inline int lapic_is_integrated(void)
218 {
219 #ifdef CONFIG_X86_64
220 	return 1;
221 #else
222 	return APIC_INTEGRATED(lapic_get_version());
223 #endif
224 }
225 
226 /*
227  * Check, whether this is a modern or a first generation APIC
228  */
229 static int modern_apic(void)
230 {
231 	/* AMD systems use old APIC versions, so check the CPU */
232 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
233 	    boot_cpu_data.x86 >= 0xf)
234 		return 1;
235 	return lapic_get_version() >= 0x14;
236 }
237 
238 /*
239  * right after this call apic become NOOP driven
240  * so apic->write/read doesn't do anything
241  */
242 void apic_disable(void)
243 {
244 	pr_info("APIC: switched to apic NOOP\n");
245 	apic = &apic_noop;
246 }
247 
248 void native_apic_wait_icr_idle(void)
249 {
250 	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
251 		cpu_relax();
252 }
253 
254 u32 native_safe_apic_wait_icr_idle(void)
255 {
256 	u32 send_status;
257 	int timeout;
258 
259 	timeout = 0;
260 	do {
261 		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
262 		if (!send_status)
263 			break;
264 		udelay(100);
265 	} while (timeout++ < 1000);
266 
267 	return send_status;
268 }
269 
270 void native_apic_icr_write(u32 low, u32 id)
271 {
272 	apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
273 	apic_write(APIC_ICR, low);
274 }
275 
276 u64 native_apic_icr_read(void)
277 {
278 	u32 icr1, icr2;
279 
280 	icr2 = apic_read(APIC_ICR2);
281 	icr1 = apic_read(APIC_ICR);
282 
283 	return icr1 | ((u64)icr2 << 32);
284 }
285 
286 /**
287  * enable_NMI_through_LVT0 - enable NMI through local vector table 0
288  */
289 void __cpuinit enable_NMI_through_LVT0(void)
290 {
291 	unsigned int v;
292 
293 	/* unmask and set to NMI */
294 	v = APIC_DM_NMI;
295 
296 	/* Level triggered for 82489DX (32bit mode) */
297 	if (!lapic_is_integrated())
298 		v |= APIC_LVT_LEVEL_TRIGGER;
299 
300 	apic_write(APIC_LVT0, v);
301 }
302 
303 #ifdef CONFIG_X86_32
304 /**
305  * get_physical_broadcast - Get number of physical broadcast IDs
306  */
307 int get_physical_broadcast(void)
308 {
309 	return modern_apic() ? 0xff : 0xf;
310 }
311 #endif
312 
313 /**
314  * lapic_get_maxlvt - get the maximum number of local vector table entries
315  */
316 int lapic_get_maxlvt(void)
317 {
318 	unsigned int v;
319 
320 	v = apic_read(APIC_LVR);
321 	/*
322 	 * - we always have APIC integrated on 64bit mode
323 	 * - 82489DXs do not report # of LVT entries
324 	 */
325 	return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
326 }
327 
328 /*
329  * Local APIC timer
330  */
331 
332 /* Clock divisor */
333 #define APIC_DIVISOR 16
334 
335 /*
336  * This function sets up the local APIC timer, with a timeout of
337  * 'clocks' APIC bus clock. During calibration we actually call
338  * this function twice on the boot CPU, once with a bogus timeout
339  * value, second time for real. The other (noncalibrating) CPUs
340  * call this function only once, with the real, calibrated value.
341  *
342  * We do reads before writes even if unnecessary, to get around the
343  * P5 APIC double write bug.
344  */
345 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
346 {
347 	unsigned int lvtt_value, tmp_value;
348 
349 	lvtt_value = LOCAL_TIMER_VECTOR;
350 	if (!oneshot)
351 		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
352 	if (!lapic_is_integrated())
353 		lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
354 
355 	if (!irqen)
356 		lvtt_value |= APIC_LVT_MASKED;
357 
358 	apic_write(APIC_LVTT, lvtt_value);
359 
360 	/*
361 	 * Divide PICLK by 16
362 	 */
363 	tmp_value = apic_read(APIC_TDCR);
364 	apic_write(APIC_TDCR,
365 		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
366 		APIC_TDR_DIV_16);
367 
368 	if (!oneshot)
369 		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
370 }
371 
372 /*
373  * Setup extended LVT, AMD specific (K8, family 10h)
374  *
375  * Vector mappings are hard coded. On K8 only offset 0 (APIC500) and
376  * MCE interrupts are supported. Thus MCE offset must be set to 0.
377  *
378  * If mask=1, the LVT entry does not generate interrupts while mask=0
379  * enables the vector. See also the BKDGs.
380  */
381 
382 #define APIC_EILVT_LVTOFF_MCE 0
383 #define APIC_EILVT_LVTOFF_IBS 1
384 
385 static void setup_APIC_eilvt(u8 lvt_off, u8 vector, u8 msg_type, u8 mask)
386 {
387 	unsigned long reg = (lvt_off << 4) + APIC_EILVTn(0);
388 	unsigned int  v   = (mask << 16) | (msg_type << 8) | vector;
389 
390 	apic_write(reg, v);
391 }
392 
393 u8 setup_APIC_eilvt_mce(u8 vector, u8 msg_type, u8 mask)
394 {
395 	setup_APIC_eilvt(APIC_EILVT_LVTOFF_MCE, vector, msg_type, mask);
396 	return APIC_EILVT_LVTOFF_MCE;
397 }
398 
399 u8 setup_APIC_eilvt_ibs(u8 vector, u8 msg_type, u8 mask)
400 {
401 	setup_APIC_eilvt(APIC_EILVT_LVTOFF_IBS, vector, msg_type, mask);
402 	return APIC_EILVT_LVTOFF_IBS;
403 }
404 EXPORT_SYMBOL_GPL(setup_APIC_eilvt_ibs);
405 
406 /*
407  * Program the next event, relative to now
408  */
409 static int lapic_next_event(unsigned long delta,
410 			    struct clock_event_device *evt)
411 {
412 	apic_write(APIC_TMICT, delta);
413 	return 0;
414 }
415 
416 /*
417  * Setup the lapic timer in periodic or oneshot mode
418  */
419 static void lapic_timer_setup(enum clock_event_mode mode,
420 			      struct clock_event_device *evt)
421 {
422 	unsigned long flags;
423 	unsigned int v;
424 
425 	/* Lapic used as dummy for broadcast ? */
426 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
427 		return;
428 
429 	local_irq_save(flags);
430 
431 	switch (mode) {
432 	case CLOCK_EVT_MODE_PERIODIC:
433 	case CLOCK_EVT_MODE_ONESHOT:
434 		__setup_APIC_LVTT(calibration_result,
435 				  mode != CLOCK_EVT_MODE_PERIODIC, 1);
436 		break;
437 	case CLOCK_EVT_MODE_UNUSED:
438 	case CLOCK_EVT_MODE_SHUTDOWN:
439 		v = apic_read(APIC_LVTT);
440 		v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
441 		apic_write(APIC_LVTT, v);
442 		apic_write(APIC_TMICT, 0);
443 		break;
444 	case CLOCK_EVT_MODE_RESUME:
445 		/* Nothing to do here */
446 		break;
447 	}
448 
449 	local_irq_restore(flags);
450 }
451 
452 /*
453  * Local APIC timer broadcast function
454  */
455 static void lapic_timer_broadcast(const struct cpumask *mask)
456 {
457 #ifdef CONFIG_SMP
458 	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
459 #endif
460 }
461 
462 /*
463  * Setup the local APIC timer for this CPU. Copy the initialized values
464  * of the boot CPU and register the clock event in the framework.
465  */
466 static void __cpuinit setup_APIC_timer(void)
467 {
468 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
469 
470 	if (cpu_has(&current_cpu_data, X86_FEATURE_ARAT)) {
471 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
472 		/* Make LAPIC timer preferrable over percpu HPET */
473 		lapic_clockevent.rating = 150;
474 	}
475 
476 	memcpy(levt, &lapic_clockevent, sizeof(*levt));
477 	levt->cpumask = cpumask_of(smp_processor_id());
478 
479 	clockevents_register_device(levt);
480 }
481 
482 /*
483  * In this functions we calibrate APIC bus clocks to the external timer.
484  *
485  * We want to do the calibration only once since we want to have local timer
486  * irqs syncron. CPUs connected by the same APIC bus have the very same bus
487  * frequency.
488  *
489  * This was previously done by reading the PIT/HPET and waiting for a wrap
490  * around to find out, that a tick has elapsed. I have a box, where the PIT
491  * readout is broken, so it never gets out of the wait loop again. This was
492  * also reported by others.
493  *
494  * Monitoring the jiffies value is inaccurate and the clockevents
495  * infrastructure allows us to do a simple substitution of the interrupt
496  * handler.
497  *
498  * The calibration routine also uses the pm_timer when possible, as the PIT
499  * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
500  * back to normal later in the boot process).
501  */
502 
503 #define LAPIC_CAL_LOOPS		(HZ/10)
504 
505 static __initdata int lapic_cal_loops = -1;
506 static __initdata long lapic_cal_t1, lapic_cal_t2;
507 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
508 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
509 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
510 
511 /*
512  * Temporary interrupt handler.
513  */
514 static void __init lapic_cal_handler(struct clock_event_device *dev)
515 {
516 	unsigned long long tsc = 0;
517 	long tapic = apic_read(APIC_TMCCT);
518 	unsigned long pm = acpi_pm_read_early();
519 
520 	if (cpu_has_tsc)
521 		rdtscll(tsc);
522 
523 	switch (lapic_cal_loops++) {
524 	case 0:
525 		lapic_cal_t1 = tapic;
526 		lapic_cal_tsc1 = tsc;
527 		lapic_cal_pm1 = pm;
528 		lapic_cal_j1 = jiffies;
529 		break;
530 
531 	case LAPIC_CAL_LOOPS:
532 		lapic_cal_t2 = tapic;
533 		lapic_cal_tsc2 = tsc;
534 		if (pm < lapic_cal_pm1)
535 			pm += ACPI_PM_OVRRUN;
536 		lapic_cal_pm2 = pm;
537 		lapic_cal_j2 = jiffies;
538 		break;
539 	}
540 }
541 
542 static int __init
543 calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
544 {
545 	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
546 	const long pm_thresh = pm_100ms / 100;
547 	unsigned long mult;
548 	u64 res;
549 
550 #ifndef CONFIG_X86_PM_TIMER
551 	return -1;
552 #endif
553 
554 	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
555 
556 	/* Check, if the PM timer is available */
557 	if (!deltapm)
558 		return -1;
559 
560 	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
561 
562 	if (deltapm > (pm_100ms - pm_thresh) &&
563 	    deltapm < (pm_100ms + pm_thresh)) {
564 		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
565 		return 0;
566 	}
567 
568 	res = (((u64)deltapm) *  mult) >> 22;
569 	do_div(res, 1000000);
570 	pr_warning("APIC calibration not consistent "
571 		   "with PM-Timer: %ldms instead of 100ms\n",(long)res);
572 
573 	/* Correct the lapic counter value */
574 	res = (((u64)(*delta)) * pm_100ms);
575 	do_div(res, deltapm);
576 	pr_info("APIC delta adjusted to PM-Timer: "
577 		"%lu (%ld)\n", (unsigned long)res, *delta);
578 	*delta = (long)res;
579 
580 	/* Correct the tsc counter value */
581 	if (cpu_has_tsc) {
582 		res = (((u64)(*deltatsc)) * pm_100ms);
583 		do_div(res, deltapm);
584 		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
585 					  "PM-Timer: %lu (%ld)\n",
586 					(unsigned long)res, *deltatsc);
587 		*deltatsc = (long)res;
588 	}
589 
590 	return 0;
591 }
592 
593 static int __init calibrate_APIC_clock(void)
594 {
595 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
596 	void (*real_handler)(struct clock_event_device *dev);
597 	unsigned long deltaj;
598 	long delta, deltatsc;
599 	int pm_referenced = 0;
600 
601 	local_irq_disable();
602 
603 	/* Replace the global interrupt handler */
604 	real_handler = global_clock_event->event_handler;
605 	global_clock_event->event_handler = lapic_cal_handler;
606 
607 	/*
608 	 * Setup the APIC counter to maximum. There is no way the lapic
609 	 * can underflow in the 100ms detection time frame
610 	 */
611 	__setup_APIC_LVTT(0xffffffff, 0, 0);
612 
613 	/* Let the interrupts run */
614 	local_irq_enable();
615 
616 	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
617 		cpu_relax();
618 
619 	local_irq_disable();
620 
621 	/* Restore the real event handler */
622 	global_clock_event->event_handler = real_handler;
623 
624 	/* Build delta t1-t2 as apic timer counts down */
625 	delta = lapic_cal_t1 - lapic_cal_t2;
626 	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
627 
628 	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
629 
630 	/* we trust the PM based calibration if possible */
631 	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
632 					&delta, &deltatsc);
633 
634 	/* Calculate the scaled math multiplication factor */
635 	lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
636 				       lapic_clockevent.shift);
637 	lapic_clockevent.max_delta_ns =
638 		clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
639 	lapic_clockevent.min_delta_ns =
640 		clockevent_delta2ns(0xF, &lapic_clockevent);
641 
642 	calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
643 
644 	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
645 	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
646 	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
647 		    calibration_result);
648 
649 	if (cpu_has_tsc) {
650 		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
651 			    "%ld.%04ld MHz.\n",
652 			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
653 			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
654 	}
655 
656 	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
657 		    "%u.%04u MHz.\n",
658 		    calibration_result / (1000000 / HZ),
659 		    calibration_result % (1000000 / HZ));
660 
661 	/*
662 	 * Do a sanity check on the APIC calibration result
663 	 */
664 	if (calibration_result < (1000000 / HZ)) {
665 		local_irq_enable();
666 		pr_warning("APIC frequency too slow, disabling apic timer\n");
667 		return -1;
668 	}
669 
670 	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
671 
672 	/*
673 	 * PM timer calibration failed or not turned on
674 	 * so lets try APIC timer based calibration
675 	 */
676 	if (!pm_referenced) {
677 		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
678 
679 		/*
680 		 * Setup the apic timer manually
681 		 */
682 		levt->event_handler = lapic_cal_handler;
683 		lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
684 		lapic_cal_loops = -1;
685 
686 		/* Let the interrupts run */
687 		local_irq_enable();
688 
689 		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
690 			cpu_relax();
691 
692 		/* Stop the lapic timer */
693 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
694 
695 		/* Jiffies delta */
696 		deltaj = lapic_cal_j2 - lapic_cal_j1;
697 		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
698 
699 		/* Check, if the jiffies result is consistent */
700 		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
701 			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
702 		else
703 			levt->features |= CLOCK_EVT_FEAT_DUMMY;
704 	} else
705 		local_irq_enable();
706 
707 	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
708 		pr_warning("APIC timer disabled due to verification failure\n");
709 			return -1;
710 	}
711 
712 	return 0;
713 }
714 
715 /*
716  * Setup the boot APIC
717  *
718  * Calibrate and verify the result.
719  */
720 void __init setup_boot_APIC_clock(void)
721 {
722 	/*
723 	 * The local apic timer can be disabled via the kernel
724 	 * commandline or from the CPU detection code. Register the lapic
725 	 * timer as a dummy clock event source on SMP systems, so the
726 	 * broadcast mechanism is used. On UP systems simply ignore it.
727 	 */
728 	if (disable_apic_timer) {
729 		pr_info("Disabling APIC timer\n");
730 		/* No broadcast on UP ! */
731 		if (num_possible_cpus() > 1) {
732 			lapic_clockevent.mult = 1;
733 			setup_APIC_timer();
734 		}
735 		return;
736 	}
737 
738 	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
739 		    "calibrating APIC timer ...\n");
740 
741 	if (calibrate_APIC_clock()) {
742 		/* No broadcast on UP ! */
743 		if (num_possible_cpus() > 1)
744 			setup_APIC_timer();
745 		return;
746 	}
747 
748 	/*
749 	 * If nmi_watchdog is set to IO_APIC, we need the
750 	 * PIT/HPET going.  Otherwise register lapic as a dummy
751 	 * device.
752 	 */
753 	if (nmi_watchdog != NMI_IO_APIC)
754 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
755 	else
756 		pr_warning("APIC timer registered as dummy,"
757 			" due to nmi_watchdog=%d!\n", nmi_watchdog);
758 
759 	/* Setup the lapic or request the broadcast */
760 	setup_APIC_timer();
761 }
762 
763 void __cpuinit setup_secondary_APIC_clock(void)
764 {
765 	setup_APIC_timer();
766 }
767 
768 /*
769  * The guts of the apic timer interrupt
770  */
771 static void local_apic_timer_interrupt(void)
772 {
773 	int cpu = smp_processor_id();
774 	struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
775 
776 	/*
777 	 * Normally we should not be here till LAPIC has been initialized but
778 	 * in some cases like kdump, its possible that there is a pending LAPIC
779 	 * timer interrupt from previous kernel's context and is delivered in
780 	 * new kernel the moment interrupts are enabled.
781 	 *
782 	 * Interrupts are enabled early and LAPIC is setup much later, hence
783 	 * its possible that when we get here evt->event_handler is NULL.
784 	 * Check for event_handler being NULL and discard the interrupt as
785 	 * spurious.
786 	 */
787 	if (!evt->event_handler) {
788 		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu);
789 		/* Switch it off */
790 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
791 		return;
792 	}
793 
794 	/*
795 	 * the NMI deadlock-detector uses this.
796 	 */
797 	inc_irq_stat(apic_timer_irqs);
798 
799 	evt->event_handler(evt);
800 }
801 
802 /*
803  * Local APIC timer interrupt. This is the most natural way for doing
804  * local interrupts, but local timer interrupts can be emulated by
805  * broadcast interrupts too. [in case the hw doesn't support APIC timers]
806  *
807  * [ if a single-CPU system runs an SMP kernel then we call the local
808  *   interrupt as well. Thus we cannot inline the local irq ... ]
809  */
810 void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
811 {
812 	struct pt_regs *old_regs = set_irq_regs(regs);
813 
814 	/*
815 	 * NOTE! We'd better ACK the irq immediately,
816 	 * because timer handling can be slow.
817 	 */
818 	ack_APIC_irq();
819 	/*
820 	 * update_process_times() expects us to have done irq_enter().
821 	 * Besides, if we don't timer interrupts ignore the global
822 	 * interrupt lock, which is the WrongThing (tm) to do.
823 	 */
824 	exit_idle();
825 	irq_enter();
826 	local_apic_timer_interrupt();
827 	irq_exit();
828 
829 	set_irq_regs(old_regs);
830 }
831 
832 int setup_profiling_timer(unsigned int multiplier)
833 {
834 	return -EINVAL;
835 }
836 
837 /*
838  * Local APIC start and shutdown
839  */
840 
841 /**
842  * clear_local_APIC - shutdown the local APIC
843  *
844  * This is called, when a CPU is disabled and before rebooting, so the state of
845  * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
846  * leftovers during boot.
847  */
848 void clear_local_APIC(void)
849 {
850 	int maxlvt;
851 	u32 v;
852 
853 	/* APIC hasn't been mapped yet */
854 	if (!x2apic_mode && !apic_phys)
855 		return;
856 
857 	maxlvt = lapic_get_maxlvt();
858 	/*
859 	 * Masking an LVT entry can trigger a local APIC error
860 	 * if the vector is zero. Mask LVTERR first to prevent this.
861 	 */
862 	if (maxlvt >= 3) {
863 		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
864 		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
865 	}
866 	/*
867 	 * Careful: we have to set masks only first to deassert
868 	 * any level-triggered sources.
869 	 */
870 	v = apic_read(APIC_LVTT);
871 	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
872 	v = apic_read(APIC_LVT0);
873 	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
874 	v = apic_read(APIC_LVT1);
875 	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
876 	if (maxlvt >= 4) {
877 		v = apic_read(APIC_LVTPC);
878 		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
879 	}
880 
881 	/* lets not touch this if we didn't frob it */
882 #ifdef CONFIG_X86_THERMAL_VECTOR
883 	if (maxlvt >= 5) {
884 		v = apic_read(APIC_LVTTHMR);
885 		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
886 	}
887 #endif
888 #ifdef CONFIG_X86_MCE_INTEL
889 	if (maxlvt >= 6) {
890 		v = apic_read(APIC_LVTCMCI);
891 		if (!(v & APIC_LVT_MASKED))
892 			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
893 	}
894 #endif
895 
896 	/*
897 	 * Clean APIC state for other OSs:
898 	 */
899 	apic_write(APIC_LVTT, APIC_LVT_MASKED);
900 	apic_write(APIC_LVT0, APIC_LVT_MASKED);
901 	apic_write(APIC_LVT1, APIC_LVT_MASKED);
902 	if (maxlvt >= 3)
903 		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
904 	if (maxlvt >= 4)
905 		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
906 
907 	/* Integrated APIC (!82489DX) ? */
908 	if (lapic_is_integrated()) {
909 		if (maxlvt > 3)
910 			/* Clear ESR due to Pentium errata 3AP and 11AP */
911 			apic_write(APIC_ESR, 0);
912 		apic_read(APIC_ESR);
913 	}
914 }
915 
916 /**
917  * disable_local_APIC - clear and disable the local APIC
918  */
919 void disable_local_APIC(void)
920 {
921 	unsigned int value;
922 
923 	/* APIC hasn't been mapped yet */
924 	if (!x2apic_mode && !apic_phys)
925 		return;
926 
927 	clear_local_APIC();
928 
929 	/*
930 	 * Disable APIC (implies clearing of registers
931 	 * for 82489DX!).
932 	 */
933 	value = apic_read(APIC_SPIV);
934 	value &= ~APIC_SPIV_APIC_ENABLED;
935 	apic_write(APIC_SPIV, value);
936 
937 #ifdef CONFIG_X86_32
938 	/*
939 	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
940 	 * restore the disabled state.
941 	 */
942 	if (enabled_via_apicbase) {
943 		unsigned int l, h;
944 
945 		rdmsr(MSR_IA32_APICBASE, l, h);
946 		l &= ~MSR_IA32_APICBASE_ENABLE;
947 		wrmsr(MSR_IA32_APICBASE, l, h);
948 	}
949 #endif
950 }
951 
952 /*
953  * If Linux enabled the LAPIC against the BIOS default disable it down before
954  * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
955  * not power-off.  Additionally clear all LVT entries before disable_local_APIC
956  * for the case where Linux didn't enable the LAPIC.
957  */
958 void lapic_shutdown(void)
959 {
960 	unsigned long flags;
961 
962 	if (!cpu_has_apic && !apic_from_smp_config())
963 		return;
964 
965 	local_irq_save(flags);
966 
967 #ifdef CONFIG_X86_32
968 	if (!enabled_via_apicbase)
969 		clear_local_APIC();
970 	else
971 #endif
972 		disable_local_APIC();
973 
974 
975 	local_irq_restore(flags);
976 }
977 
978 /*
979  * This is to verify that we're looking at a real local APIC.
980  * Check these against your board if the CPUs aren't getting
981  * started for no apparent reason.
982  */
983 int __init verify_local_APIC(void)
984 {
985 	unsigned int reg0, reg1;
986 
987 	/*
988 	 * The version register is read-only in a real APIC.
989 	 */
990 	reg0 = apic_read(APIC_LVR);
991 	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
992 	apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
993 	reg1 = apic_read(APIC_LVR);
994 	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
995 
996 	/*
997 	 * The two version reads above should print the same
998 	 * numbers.  If the second one is different, then we
999 	 * poke at a non-APIC.
1000 	 */
1001 	if (reg1 != reg0)
1002 		return 0;
1003 
1004 	/*
1005 	 * Check if the version looks reasonably.
1006 	 */
1007 	reg1 = GET_APIC_VERSION(reg0);
1008 	if (reg1 == 0x00 || reg1 == 0xff)
1009 		return 0;
1010 	reg1 = lapic_get_maxlvt();
1011 	if (reg1 < 0x02 || reg1 == 0xff)
1012 		return 0;
1013 
1014 	/*
1015 	 * The ID register is read/write in a real APIC.
1016 	 */
1017 	reg0 = apic_read(APIC_ID);
1018 	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
1019 	apic_write(APIC_ID, reg0 ^ apic->apic_id_mask);
1020 	reg1 = apic_read(APIC_ID);
1021 	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
1022 	apic_write(APIC_ID, reg0);
1023 	if (reg1 != (reg0 ^ apic->apic_id_mask))
1024 		return 0;
1025 
1026 	/*
1027 	 * The next two are just to see if we have sane values.
1028 	 * They're only really relevant if we're in Virtual Wire
1029 	 * compatibility mode, but most boxes are anymore.
1030 	 */
1031 	reg0 = apic_read(APIC_LVT0);
1032 	apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
1033 	reg1 = apic_read(APIC_LVT1);
1034 	apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
1035 
1036 	return 1;
1037 }
1038 
1039 /**
1040  * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1041  */
1042 void __init sync_Arb_IDs(void)
1043 {
1044 	/*
1045 	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1046 	 * needed on AMD.
1047 	 */
1048 	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1049 		return;
1050 
1051 	/*
1052 	 * Wait for idle.
1053 	 */
1054 	apic_wait_icr_idle();
1055 
1056 	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1057 	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1058 			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1059 }
1060 
1061 /*
1062  * An initial setup of the virtual wire mode.
1063  */
1064 void __init init_bsp_APIC(void)
1065 {
1066 	unsigned int value;
1067 
1068 	/*
1069 	 * Don't do the setup now if we have a SMP BIOS as the
1070 	 * through-I/O-APIC virtual wire mode might be active.
1071 	 */
1072 	if (smp_found_config || !cpu_has_apic)
1073 		return;
1074 
1075 	/*
1076 	 * Do not trust the local APIC being empty at bootup.
1077 	 */
1078 	clear_local_APIC();
1079 
1080 	/*
1081 	 * Enable APIC.
1082 	 */
1083 	value = apic_read(APIC_SPIV);
1084 	value &= ~APIC_VECTOR_MASK;
1085 	value |= APIC_SPIV_APIC_ENABLED;
1086 
1087 #ifdef CONFIG_X86_32
1088 	/* This bit is reserved on P4/Xeon and should be cleared */
1089 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1090 	    (boot_cpu_data.x86 == 15))
1091 		value &= ~APIC_SPIV_FOCUS_DISABLED;
1092 	else
1093 #endif
1094 		value |= APIC_SPIV_FOCUS_DISABLED;
1095 	value |= SPURIOUS_APIC_VECTOR;
1096 	apic_write(APIC_SPIV, value);
1097 
1098 	/*
1099 	 * Set up the virtual wire mode.
1100 	 */
1101 	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1102 	value = APIC_DM_NMI;
1103 	if (!lapic_is_integrated())		/* 82489DX */
1104 		value |= APIC_LVT_LEVEL_TRIGGER;
1105 	apic_write(APIC_LVT1, value);
1106 }
1107 
1108 static void __cpuinit lapic_setup_esr(void)
1109 {
1110 	unsigned int oldvalue, value, maxlvt;
1111 
1112 	if (!lapic_is_integrated()) {
1113 		pr_info("No ESR for 82489DX.\n");
1114 		return;
1115 	}
1116 
1117 	if (apic->disable_esr) {
1118 		/*
1119 		 * Something untraceable is creating bad interrupts on
1120 		 * secondary quads ... for the moment, just leave the
1121 		 * ESR disabled - we can't do anything useful with the
1122 		 * errors anyway - mbligh
1123 		 */
1124 		pr_info("Leaving ESR disabled.\n");
1125 		return;
1126 	}
1127 
1128 	maxlvt = lapic_get_maxlvt();
1129 	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1130 		apic_write(APIC_ESR, 0);
1131 	oldvalue = apic_read(APIC_ESR);
1132 
1133 	/* enables sending errors */
1134 	value = ERROR_APIC_VECTOR;
1135 	apic_write(APIC_LVTERR, value);
1136 
1137 	/*
1138 	 * spec says clear errors after enabling vector.
1139 	 */
1140 	if (maxlvt > 3)
1141 		apic_write(APIC_ESR, 0);
1142 	value = apic_read(APIC_ESR);
1143 	if (value != oldvalue)
1144 		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1145 			"vector: 0x%08x  after: 0x%08x\n",
1146 			oldvalue, value);
1147 }
1148 
1149 
1150 /**
1151  * setup_local_APIC - setup the local APIC
1152  */
1153 void __cpuinit setup_local_APIC(void)
1154 {
1155 	unsigned int value, queued;
1156 	int i, j, acked = 0;
1157 	unsigned long long tsc = 0, ntsc;
1158 	long long max_loops = cpu_khz;
1159 
1160 	if (cpu_has_tsc)
1161 		rdtscll(tsc);
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 	do {
1214 		queued = 0;
1215 		for (i = APIC_ISR_NR - 1; i >= 0; i--)
1216 			queued |= apic_read(APIC_IRR + i*0x10);
1217 
1218 		for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1219 			value = apic_read(APIC_ISR + i*0x10);
1220 			for (j = 31; j >= 0; j--) {
1221 				if (value & (1<<j)) {
1222 					ack_APIC_irq();
1223 					acked++;
1224 				}
1225 			}
1226 		}
1227 		if (acked > 256) {
1228 			printk(KERN_ERR "LAPIC pending interrupts after %d EOI\n",
1229 			       acked);
1230 			break;
1231 		}
1232 		if (cpu_has_tsc) {
1233 			rdtscll(ntsc);
1234 			max_loops = (cpu_khz << 10) - (ntsc - tsc);
1235 		} else
1236 			max_loops--;
1237 	} while (queued && max_loops > 0);
1238 	WARN_ON(max_loops <= 0);
1239 
1240 	/*
1241 	 * Now that we are all set up, enable the APIC
1242 	 */
1243 	value = apic_read(APIC_SPIV);
1244 	value &= ~APIC_VECTOR_MASK;
1245 	/*
1246 	 * Enable APIC
1247 	 */
1248 	value |= APIC_SPIV_APIC_ENABLED;
1249 
1250 #ifdef CONFIG_X86_32
1251 	/*
1252 	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1253 	 * certain networking cards. If high frequency interrupts are
1254 	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1255 	 * entry is masked/unmasked at a high rate as well then sooner or
1256 	 * later IOAPIC line gets 'stuck', no more interrupts are received
1257 	 * from the device. If focus CPU is disabled then the hang goes
1258 	 * away, oh well :-(
1259 	 *
1260 	 * [ This bug can be reproduced easily with a level-triggered
1261 	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1262 	 *   BX chipset. ]
1263 	 */
1264 	/*
1265 	 * Actually disabling the focus CPU check just makes the hang less
1266 	 * frequent as it makes the interrupt distributon model be more
1267 	 * like LRU than MRU (the short-term load is more even across CPUs).
1268 	 * See also the comment in end_level_ioapic_irq().  --macro
1269 	 */
1270 
1271 	/*
1272 	 * - enable focus processor (bit==0)
1273 	 * - 64bit mode always use processor focus
1274 	 *   so no need to set it
1275 	 */
1276 	value &= ~APIC_SPIV_FOCUS_DISABLED;
1277 #endif
1278 
1279 	/*
1280 	 * Set spurious IRQ vector
1281 	 */
1282 	value |= SPURIOUS_APIC_VECTOR;
1283 	apic_write(APIC_SPIV, value);
1284 
1285 	/*
1286 	 * Set up LVT0, LVT1:
1287 	 *
1288 	 * set up through-local-APIC on the BP's LINT0. This is not
1289 	 * strictly necessary in pure symmetric-IO mode, but sometimes
1290 	 * we delegate interrupts to the 8259A.
1291 	 */
1292 	/*
1293 	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1294 	 */
1295 	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1296 	if (!smp_processor_id() && (pic_mode || !value)) {
1297 		value = APIC_DM_EXTINT;
1298 		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n",
1299 				smp_processor_id());
1300 	} else {
1301 		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1302 		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n",
1303 				smp_processor_id());
1304 	}
1305 	apic_write(APIC_LVT0, value);
1306 
1307 	/*
1308 	 * only the BP should see the LINT1 NMI signal, obviously.
1309 	 */
1310 	if (!smp_processor_id())
1311 		value = APIC_DM_NMI;
1312 	else
1313 		value = APIC_DM_NMI | APIC_LVT_MASKED;
1314 	if (!lapic_is_integrated())		/* 82489DX */
1315 		value |= APIC_LVT_LEVEL_TRIGGER;
1316 	apic_write(APIC_LVT1, value);
1317 
1318 	preempt_enable();
1319 
1320 #ifdef CONFIG_X86_MCE_INTEL
1321 	/* Recheck CMCI information after local APIC is up on CPU #0 */
1322 	if (smp_processor_id() == 0)
1323 		cmci_recheck();
1324 #endif
1325 }
1326 
1327 void __cpuinit end_local_APIC_setup(void)
1328 {
1329 	lapic_setup_esr();
1330 
1331 #ifdef CONFIG_X86_32
1332 	{
1333 		unsigned int value;
1334 		/* Disable the local apic timer */
1335 		value = apic_read(APIC_LVTT);
1336 		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1337 		apic_write(APIC_LVTT, value);
1338 	}
1339 #endif
1340 
1341 	setup_apic_nmi_watchdog(NULL);
1342 	apic_pm_activate();
1343 }
1344 
1345 #ifdef CONFIG_X86_X2APIC
1346 void check_x2apic(void)
1347 {
1348 	if (x2apic_enabled()) {
1349 		pr_info("x2apic enabled by BIOS, switching to x2apic ops\n");
1350 		x2apic_preenabled = x2apic_mode = 1;
1351 	}
1352 }
1353 
1354 void enable_x2apic(void)
1355 {
1356 	int msr, msr2;
1357 
1358 	if (!x2apic_mode)
1359 		return;
1360 
1361 	rdmsr(MSR_IA32_APICBASE, msr, msr2);
1362 	if (!(msr & X2APIC_ENABLE)) {
1363 		printk_once(KERN_INFO "Enabling x2apic\n");
1364 		wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, 0);
1365 	}
1366 }
1367 #endif /* CONFIG_X86_X2APIC */
1368 
1369 int __init enable_IR(void)
1370 {
1371 #ifdef CONFIG_INTR_REMAP
1372 	if (!intr_remapping_supported()) {
1373 		pr_debug("intr-remapping not supported\n");
1374 		return 0;
1375 	}
1376 
1377 	if (!x2apic_preenabled && skip_ioapic_setup) {
1378 		pr_info("Skipped enabling intr-remap because of skipping "
1379 			"io-apic setup\n");
1380 		return 0;
1381 	}
1382 
1383 	if (enable_intr_remapping(x2apic_supported()))
1384 		return 0;
1385 
1386 	pr_info("Enabled Interrupt-remapping\n");
1387 
1388 	return 1;
1389 
1390 #endif
1391 	return 0;
1392 }
1393 
1394 void __init enable_IR_x2apic(void)
1395 {
1396 	unsigned long flags;
1397 	struct IO_APIC_route_entry **ioapic_entries = NULL;
1398 	int ret, x2apic_enabled = 0;
1399 	int dmar_table_init_ret;
1400 
1401 	dmar_table_init_ret = dmar_table_init();
1402 	if (dmar_table_init_ret && !x2apic_supported())
1403 		return;
1404 
1405 	ioapic_entries = alloc_ioapic_entries();
1406 	if (!ioapic_entries) {
1407 		pr_err("Allocate ioapic_entries failed\n");
1408 		goto out;
1409 	}
1410 
1411 	ret = save_IO_APIC_setup(ioapic_entries);
1412 	if (ret) {
1413 		pr_info("Saving IO-APIC state failed: %d\n", ret);
1414 		goto out;
1415 	}
1416 
1417 	local_irq_save(flags);
1418 	legacy_pic->mask_all();
1419 	mask_IO_APIC_setup(ioapic_entries);
1420 
1421 	if (dmar_table_init_ret)
1422 		ret = 0;
1423 	else
1424 		ret = enable_IR();
1425 
1426 	if (!ret) {
1427 		/* IR is required if there is APIC ID > 255 even when running
1428 		 * under KVM
1429 		 */
1430 		if (max_physical_apicid > 255 || !kvm_para_available())
1431 			goto nox2apic;
1432 		/*
1433 		 * without IR all CPUs can be addressed by IOAPIC/MSI
1434 		 * only in physical mode
1435 		 */
1436 		x2apic_force_phys();
1437 	}
1438 
1439 	x2apic_enabled = 1;
1440 
1441 	if (x2apic_supported() && !x2apic_mode) {
1442 		x2apic_mode = 1;
1443 		enable_x2apic();
1444 		pr_info("Enabled x2apic\n");
1445 	}
1446 
1447 nox2apic:
1448 	if (!ret) /* IR enabling failed */
1449 		restore_IO_APIC_setup(ioapic_entries);
1450 	legacy_pic->restore_mask();
1451 	local_irq_restore(flags);
1452 
1453 out:
1454 	if (ioapic_entries)
1455 		free_ioapic_entries(ioapic_entries);
1456 
1457 	if (x2apic_enabled)
1458 		return;
1459 
1460 	if (x2apic_preenabled)
1461 		panic("x2apic: enabled by BIOS but kernel init failed.");
1462 	else if (cpu_has_x2apic)
1463 		pr_info("Not enabling x2apic, Intr-remapping init failed.\n");
1464 }
1465 
1466 #ifdef CONFIG_X86_64
1467 /*
1468  * Detect and enable local APICs on non-SMP boards.
1469  * Original code written by Keir Fraser.
1470  * On AMD64 we trust the BIOS - if it says no APIC it is likely
1471  * not correctly set up (usually the APIC timer won't work etc.)
1472  */
1473 static int __init detect_init_APIC(void)
1474 {
1475 	if (!cpu_has_apic) {
1476 		pr_info("No local APIC present\n");
1477 		return -1;
1478 	}
1479 
1480 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1481 	return 0;
1482 }
1483 #else
1484 /*
1485  * Detect and initialize APIC
1486  */
1487 static int __init detect_init_APIC(void)
1488 {
1489 	u32 h, l, features;
1490 
1491 	/* Disabled by kernel option? */
1492 	if (disable_apic)
1493 		return -1;
1494 
1495 	switch (boot_cpu_data.x86_vendor) {
1496 	case X86_VENDOR_AMD:
1497 		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1498 		    (boot_cpu_data.x86 >= 15))
1499 			break;
1500 		goto no_apic;
1501 	case X86_VENDOR_INTEL:
1502 		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1503 		    (boot_cpu_data.x86 == 5 && cpu_has_apic))
1504 			break;
1505 		goto no_apic;
1506 	default:
1507 		goto no_apic;
1508 	}
1509 
1510 	if (!cpu_has_apic) {
1511 		/*
1512 		 * Over-ride BIOS and try to enable the local APIC only if
1513 		 * "lapic" specified.
1514 		 */
1515 		if (!force_enable_local_apic) {
1516 			pr_info("Local APIC disabled by BIOS -- "
1517 				"you can enable it with \"lapic\"\n");
1518 			return -1;
1519 		}
1520 		/*
1521 		 * Some BIOSes disable the local APIC in the APIC_BASE
1522 		 * MSR. This can only be done in software for Intel P6 or later
1523 		 * and AMD K7 (Model > 1) or later.
1524 		 */
1525 		rdmsr(MSR_IA32_APICBASE, l, h);
1526 		if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1527 			pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1528 			l &= ~MSR_IA32_APICBASE_BASE;
1529 			l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE;
1530 			wrmsr(MSR_IA32_APICBASE, l, h);
1531 			enabled_via_apicbase = 1;
1532 		}
1533 	}
1534 	/*
1535 	 * The APIC feature bit should now be enabled
1536 	 * in `cpuid'
1537 	 */
1538 	features = cpuid_edx(1);
1539 	if (!(features & (1 << X86_FEATURE_APIC))) {
1540 		pr_warning("Could not enable APIC!\n");
1541 		return -1;
1542 	}
1543 	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1544 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1545 
1546 	/* The BIOS may have set up the APIC at some other address */
1547 	rdmsr(MSR_IA32_APICBASE, l, h);
1548 	if (l & MSR_IA32_APICBASE_ENABLE)
1549 		mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1550 
1551 	pr_info("Found and enabled local APIC!\n");
1552 
1553 	apic_pm_activate();
1554 
1555 	return 0;
1556 
1557 no_apic:
1558 	pr_info("No local APIC present or hardware disabled\n");
1559 	return -1;
1560 }
1561 #endif
1562 
1563 #ifdef CONFIG_X86_64
1564 void __init early_init_lapic_mapping(void)
1565 {
1566 	/*
1567 	 * If no local APIC can be found then go out
1568 	 * : it means there is no mpatable and MADT
1569 	 */
1570 	if (!smp_found_config)
1571 		return;
1572 
1573 	set_fixmap_nocache(FIX_APIC_BASE, mp_lapic_addr);
1574 	apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
1575 		    APIC_BASE, mp_lapic_addr);
1576 
1577 	/*
1578 	 * Fetch the APIC ID of the BSP in case we have a
1579 	 * default configuration (or the MP table is broken).
1580 	 */
1581 	boot_cpu_physical_apicid = read_apic_id();
1582 }
1583 #endif
1584 
1585 /**
1586  * init_apic_mappings - initialize APIC mappings
1587  */
1588 void __init init_apic_mappings(void)
1589 {
1590 	unsigned int new_apicid;
1591 
1592 	if (x2apic_mode) {
1593 		boot_cpu_physical_apicid = read_apic_id();
1594 		return;
1595 	}
1596 
1597 	/* If no local APIC can be found return early */
1598 	if (!smp_found_config && detect_init_APIC()) {
1599 		/* lets NOP'ify apic operations */
1600 		pr_info("APIC: disable apic facility\n");
1601 		apic_disable();
1602 	} else {
1603 		apic_phys = mp_lapic_addr;
1604 
1605 		/*
1606 		 * acpi lapic path already maps that address in
1607 		 * acpi_register_lapic_address()
1608 		 */
1609 		if (!acpi_lapic && !smp_found_config)
1610 			set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
1611 
1612 		apic_printk(APIC_VERBOSE, "mapped APIC to %08lx (%08lx)\n",
1613 					APIC_BASE, apic_phys);
1614 	}
1615 
1616 	/*
1617 	 * Fetch the APIC ID of the BSP in case we have a
1618 	 * default configuration (or the MP table is broken).
1619 	 */
1620 	new_apicid = read_apic_id();
1621 	if (boot_cpu_physical_apicid != new_apicid) {
1622 		boot_cpu_physical_apicid = new_apicid;
1623 		/*
1624 		 * yeah -- we lie about apic_version
1625 		 * in case if apic was disabled via boot option
1626 		 * but it's not a problem for SMP compiled kernel
1627 		 * since smp_sanity_check is prepared for such a case
1628 		 * and disable smp mode
1629 		 */
1630 		apic_version[new_apicid] =
1631 			 GET_APIC_VERSION(apic_read(APIC_LVR));
1632 	}
1633 }
1634 
1635 /*
1636  * This initializes the IO-APIC and APIC hardware if this is
1637  * a UP kernel.
1638  */
1639 int apic_version[MAX_APICS];
1640 
1641 int __init APIC_init_uniprocessor(void)
1642 {
1643 	if (disable_apic) {
1644 		pr_info("Apic disabled\n");
1645 		return -1;
1646 	}
1647 #ifdef CONFIG_X86_64
1648 	if (!cpu_has_apic) {
1649 		disable_apic = 1;
1650 		pr_info("Apic disabled by BIOS\n");
1651 		return -1;
1652 	}
1653 #else
1654 	if (!smp_found_config && !cpu_has_apic)
1655 		return -1;
1656 
1657 	/*
1658 	 * Complain if the BIOS pretends there is one.
1659 	 */
1660 	if (!cpu_has_apic &&
1661 	    APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
1662 		pr_err("BIOS bug, local APIC 0x%x not detected!...\n",
1663 			boot_cpu_physical_apicid);
1664 		return -1;
1665 	}
1666 #endif
1667 
1668 #ifndef CONFIG_SMP
1669 	enable_IR_x2apic();
1670 	default_setup_apic_routing();
1671 #endif
1672 
1673 	verify_local_APIC();
1674 	connect_bsp_APIC();
1675 
1676 #ifdef CONFIG_X86_64
1677 	apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
1678 #else
1679 	/*
1680 	 * Hack: In case of kdump, after a crash, kernel might be booting
1681 	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
1682 	 * might be zero if read from MP tables. Get it from LAPIC.
1683 	 */
1684 # ifdef CONFIG_CRASH_DUMP
1685 	boot_cpu_physical_apicid = read_apic_id();
1686 # endif
1687 #endif
1688 	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
1689 	setup_local_APIC();
1690 
1691 #ifdef CONFIG_X86_IO_APIC
1692 	/*
1693 	 * Now enable IO-APICs, actually call clear_IO_APIC
1694 	 * We need clear_IO_APIC before enabling error vector
1695 	 */
1696 	if (!skip_ioapic_setup && nr_ioapics)
1697 		enable_IO_APIC();
1698 #endif
1699 
1700 	end_local_APIC_setup();
1701 
1702 #ifdef CONFIG_X86_IO_APIC
1703 	if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1704 		setup_IO_APIC();
1705 	else {
1706 		nr_ioapics = 0;
1707 		localise_nmi_watchdog();
1708 	}
1709 #else
1710 	localise_nmi_watchdog();
1711 #endif
1712 
1713 	x86_init.timers.setup_percpu_clockev();
1714 #ifdef CONFIG_X86_64
1715 	check_nmi_watchdog();
1716 #endif
1717 
1718 	return 0;
1719 }
1720 
1721 /*
1722  * Local APIC interrupts
1723  */
1724 
1725 /*
1726  * This interrupt should _never_ happen with our APIC/SMP architecture
1727  */
1728 void smp_spurious_interrupt(struct pt_regs *regs)
1729 {
1730 	u32 v;
1731 
1732 	exit_idle();
1733 	irq_enter();
1734 	/*
1735 	 * Check if this really is a spurious interrupt and ACK it
1736 	 * if it is a vectored one.  Just in case...
1737 	 * Spurious interrupts should not be ACKed.
1738 	 */
1739 	v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1740 	if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1741 		ack_APIC_irq();
1742 
1743 	inc_irq_stat(irq_spurious_count);
1744 
1745 	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
1746 	pr_info("spurious APIC interrupt on CPU#%d, "
1747 		"should never happen.\n", smp_processor_id());
1748 	irq_exit();
1749 }
1750 
1751 /*
1752  * This interrupt should never happen with our APIC/SMP architecture
1753  */
1754 void smp_error_interrupt(struct pt_regs *regs)
1755 {
1756 	u32 v, v1;
1757 
1758 	exit_idle();
1759 	irq_enter();
1760 	/* First tickle the hardware, only then report what went on. -- REW */
1761 	v = apic_read(APIC_ESR);
1762 	apic_write(APIC_ESR, 0);
1763 	v1 = apic_read(APIC_ESR);
1764 	ack_APIC_irq();
1765 	atomic_inc(&irq_err_count);
1766 
1767 	/*
1768 	 * Here is what the APIC error bits mean:
1769 	 * 0: Send CS error
1770 	 * 1: Receive CS error
1771 	 * 2: Send accept error
1772 	 * 3: Receive accept error
1773 	 * 4: Reserved
1774 	 * 5: Send illegal vector
1775 	 * 6: Received illegal vector
1776 	 * 7: Illegal register address
1777 	 */
1778 	pr_debug("APIC error on CPU%d: %02x(%02x)\n",
1779 		smp_processor_id(), v , v1);
1780 	irq_exit();
1781 }
1782 
1783 /**
1784  * connect_bsp_APIC - attach the APIC to the interrupt system
1785  */
1786 void __init connect_bsp_APIC(void)
1787 {
1788 #ifdef CONFIG_X86_32
1789 	if (pic_mode) {
1790 		/*
1791 		 * Do not trust the local APIC being empty at bootup.
1792 		 */
1793 		clear_local_APIC();
1794 		/*
1795 		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
1796 		 * local APIC to INT and NMI lines.
1797 		 */
1798 		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
1799 				"enabling APIC mode.\n");
1800 		imcr_pic_to_apic();
1801 	}
1802 #endif
1803 	if (apic->enable_apic_mode)
1804 		apic->enable_apic_mode();
1805 }
1806 
1807 /**
1808  * disconnect_bsp_APIC - detach the APIC from the interrupt system
1809  * @virt_wire_setup:	indicates, whether virtual wire mode is selected
1810  *
1811  * Virtual wire mode is necessary to deliver legacy interrupts even when the
1812  * APIC is disabled.
1813  */
1814 void disconnect_bsp_APIC(int virt_wire_setup)
1815 {
1816 	unsigned int value;
1817 
1818 #ifdef CONFIG_X86_32
1819 	if (pic_mode) {
1820 		/*
1821 		 * Put the board back into PIC mode (has an effect only on
1822 		 * certain older boards).  Note that APIC interrupts, including
1823 		 * IPIs, won't work beyond this point!  The only exception are
1824 		 * INIT IPIs.
1825 		 */
1826 		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
1827 				"entering PIC mode.\n");
1828 		imcr_apic_to_pic();
1829 		return;
1830 	}
1831 #endif
1832 
1833 	/* Go back to Virtual Wire compatibility mode */
1834 
1835 	/* For the spurious interrupt use vector F, and enable it */
1836 	value = apic_read(APIC_SPIV);
1837 	value &= ~APIC_VECTOR_MASK;
1838 	value |= APIC_SPIV_APIC_ENABLED;
1839 	value |= 0xf;
1840 	apic_write(APIC_SPIV, value);
1841 
1842 	if (!virt_wire_setup) {
1843 		/*
1844 		 * For LVT0 make it edge triggered, active high,
1845 		 * external and enabled
1846 		 */
1847 		value = apic_read(APIC_LVT0);
1848 		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1849 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1850 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1851 		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1852 		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1853 		apic_write(APIC_LVT0, value);
1854 	} else {
1855 		/* Disable LVT0 */
1856 		apic_write(APIC_LVT0, APIC_LVT_MASKED);
1857 	}
1858 
1859 	/*
1860 	 * For LVT1 make it edge triggered, active high,
1861 	 * nmi and enabled
1862 	 */
1863 	value = apic_read(APIC_LVT1);
1864 	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1865 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1866 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1867 	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1868 	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1869 	apic_write(APIC_LVT1, value);
1870 }
1871 
1872 void __cpuinit generic_processor_info(int apicid, int version)
1873 {
1874 	int cpu;
1875 
1876 	/*
1877 	 * Validate version
1878 	 */
1879 	if (version == 0x0) {
1880 		pr_warning("BIOS bug, APIC version is 0 for CPU#%d! "
1881 			   "fixing up to 0x10. (tell your hw vendor)\n",
1882 				version);
1883 		version = 0x10;
1884 	}
1885 	apic_version[apicid] = version;
1886 
1887 	if (num_processors >= nr_cpu_ids) {
1888 		int max = nr_cpu_ids;
1889 		int thiscpu = max + disabled_cpus;
1890 
1891 		pr_warning(
1892 			"ACPI: NR_CPUS/possible_cpus limit of %i reached."
1893 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
1894 
1895 		disabled_cpus++;
1896 		return;
1897 	}
1898 
1899 	num_processors++;
1900 	cpu = cpumask_next_zero(-1, cpu_present_mask);
1901 
1902 	if (version != apic_version[boot_cpu_physical_apicid])
1903 		WARN_ONCE(1,
1904 			"ACPI: apic version mismatch, bootcpu: %x cpu %d: %x\n",
1905 			apic_version[boot_cpu_physical_apicid], cpu, version);
1906 
1907 	physid_set(apicid, phys_cpu_present_map);
1908 	if (apicid == boot_cpu_physical_apicid) {
1909 		/*
1910 		 * x86_bios_cpu_apicid is required to have processors listed
1911 		 * in same order as logical cpu numbers. Hence the first
1912 		 * entry is BSP, and so on.
1913 		 */
1914 		cpu = 0;
1915 	}
1916 	if (apicid > max_physical_apicid)
1917 		max_physical_apicid = apicid;
1918 
1919 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
1920 	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
1921 	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
1922 #endif
1923 
1924 	set_cpu_possible(cpu, true);
1925 	set_cpu_present(cpu, true);
1926 }
1927 
1928 int hard_smp_processor_id(void)
1929 {
1930 	return read_apic_id();
1931 }
1932 
1933 void default_init_apic_ldr(void)
1934 {
1935 	unsigned long val;
1936 
1937 	apic_write(APIC_DFR, APIC_DFR_VALUE);
1938 	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
1939 	val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
1940 	apic_write(APIC_LDR, val);
1941 }
1942 
1943 #ifdef CONFIG_X86_32
1944 int default_apicid_to_node(int logical_apicid)
1945 {
1946 #ifdef CONFIG_SMP
1947 	return apicid_2_node[hard_smp_processor_id()];
1948 #else
1949 	return 0;
1950 #endif
1951 }
1952 #endif
1953 
1954 /*
1955  * Power management
1956  */
1957 #ifdef CONFIG_PM
1958 
1959 static struct {
1960 	/*
1961 	 * 'active' is true if the local APIC was enabled by us and
1962 	 * not the BIOS; this signifies that we are also responsible
1963 	 * for disabling it before entering apm/acpi suspend
1964 	 */
1965 	int active;
1966 	/* r/w apic fields */
1967 	unsigned int apic_id;
1968 	unsigned int apic_taskpri;
1969 	unsigned int apic_ldr;
1970 	unsigned int apic_dfr;
1971 	unsigned int apic_spiv;
1972 	unsigned int apic_lvtt;
1973 	unsigned int apic_lvtpc;
1974 	unsigned int apic_lvt0;
1975 	unsigned int apic_lvt1;
1976 	unsigned int apic_lvterr;
1977 	unsigned int apic_tmict;
1978 	unsigned int apic_tdcr;
1979 	unsigned int apic_thmr;
1980 } apic_pm_state;
1981 
1982 static int lapic_suspend(struct sys_device *dev, pm_message_t state)
1983 {
1984 	unsigned long flags;
1985 	int maxlvt;
1986 
1987 	if (!apic_pm_state.active)
1988 		return 0;
1989 
1990 	maxlvt = lapic_get_maxlvt();
1991 
1992 	apic_pm_state.apic_id = apic_read(APIC_ID);
1993 	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
1994 	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
1995 	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
1996 	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
1997 	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
1998 	if (maxlvt >= 4)
1999 		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2000 	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2001 	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2002 	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2003 	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2004 	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2005 #ifdef CONFIG_X86_THERMAL_VECTOR
2006 	if (maxlvt >= 5)
2007 		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2008 #endif
2009 
2010 	local_irq_save(flags);
2011 	disable_local_APIC();
2012 
2013 	if (intr_remapping_enabled)
2014 		disable_intr_remapping();
2015 
2016 	local_irq_restore(flags);
2017 	return 0;
2018 }
2019 
2020 static int lapic_resume(struct sys_device *dev)
2021 {
2022 	unsigned int l, h;
2023 	unsigned long flags;
2024 	int maxlvt;
2025 	int ret = 0;
2026 	struct IO_APIC_route_entry **ioapic_entries = NULL;
2027 
2028 	if (!apic_pm_state.active)
2029 		return 0;
2030 
2031 	local_irq_save(flags);
2032 	if (intr_remapping_enabled) {
2033 		ioapic_entries = alloc_ioapic_entries();
2034 		if (!ioapic_entries) {
2035 			WARN(1, "Alloc ioapic_entries in lapic resume failed.");
2036 			ret = -ENOMEM;
2037 			goto restore;
2038 		}
2039 
2040 		ret = save_IO_APIC_setup(ioapic_entries);
2041 		if (ret) {
2042 			WARN(1, "Saving IO-APIC state failed: %d\n", ret);
2043 			free_ioapic_entries(ioapic_entries);
2044 			goto restore;
2045 		}
2046 
2047 		mask_IO_APIC_setup(ioapic_entries);
2048 		legacy_pic->mask_all();
2049 	}
2050 
2051 	if (x2apic_mode)
2052 		enable_x2apic();
2053 	else {
2054 		/*
2055 		 * Make sure the APICBASE points to the right address
2056 		 *
2057 		 * FIXME! This will be wrong if we ever support suspend on
2058 		 * SMP! We'll need to do this as part of the CPU restore!
2059 		 */
2060 		rdmsr(MSR_IA32_APICBASE, l, h);
2061 		l &= ~MSR_IA32_APICBASE_BASE;
2062 		l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2063 		wrmsr(MSR_IA32_APICBASE, l, h);
2064 	}
2065 
2066 	maxlvt = lapic_get_maxlvt();
2067 	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2068 	apic_write(APIC_ID, apic_pm_state.apic_id);
2069 	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2070 	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2071 	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2072 	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2073 	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2074 	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2075 #if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
2076 	if (maxlvt >= 5)
2077 		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2078 #endif
2079 	if (maxlvt >= 4)
2080 		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2081 	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2082 	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2083 	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2084 	apic_write(APIC_ESR, 0);
2085 	apic_read(APIC_ESR);
2086 	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2087 	apic_write(APIC_ESR, 0);
2088 	apic_read(APIC_ESR);
2089 
2090 	if (intr_remapping_enabled) {
2091 		reenable_intr_remapping(x2apic_mode);
2092 		legacy_pic->restore_mask();
2093 		restore_IO_APIC_setup(ioapic_entries);
2094 		free_ioapic_entries(ioapic_entries);
2095 	}
2096 restore:
2097 	local_irq_restore(flags);
2098 
2099 	return ret;
2100 }
2101 
2102 /*
2103  * This device has no shutdown method - fully functioning local APICs
2104  * are needed on every CPU up until machine_halt/restart/poweroff.
2105  */
2106 
2107 static struct sysdev_class lapic_sysclass = {
2108 	.name		= "lapic",
2109 	.resume		= lapic_resume,
2110 	.suspend	= lapic_suspend,
2111 };
2112 
2113 static struct sys_device device_lapic = {
2114 	.id	= 0,
2115 	.cls	= &lapic_sysclass,
2116 };
2117 
2118 static void __cpuinit apic_pm_activate(void)
2119 {
2120 	apic_pm_state.active = 1;
2121 }
2122 
2123 static int __init init_lapic_sysfs(void)
2124 {
2125 	int error;
2126 
2127 	if (!cpu_has_apic)
2128 		return 0;
2129 	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2130 
2131 	error = sysdev_class_register(&lapic_sysclass);
2132 	if (!error)
2133 		error = sysdev_register(&device_lapic);
2134 	return error;
2135 }
2136 
2137 /* local apic needs to resume before other devices access its registers. */
2138 core_initcall(init_lapic_sysfs);
2139 
2140 #else	/* CONFIG_PM */
2141 
2142 static void apic_pm_activate(void) { }
2143 
2144 #endif	/* CONFIG_PM */
2145 
2146 #ifdef CONFIG_X86_64
2147 
2148 static int __cpuinit apic_cluster_num(void)
2149 {
2150 	int i, clusters, zeros;
2151 	unsigned id;
2152 	u16 *bios_cpu_apicid;
2153 	DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
2154 
2155 	bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
2156 	bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
2157 
2158 	for (i = 0; i < nr_cpu_ids; i++) {
2159 		/* are we being called early in kernel startup? */
2160 		if (bios_cpu_apicid) {
2161 			id = bios_cpu_apicid[i];
2162 		} else if (i < nr_cpu_ids) {
2163 			if (cpu_present(i))
2164 				id = per_cpu(x86_bios_cpu_apicid, i);
2165 			else
2166 				continue;
2167 		} else
2168 			break;
2169 
2170 		if (id != BAD_APICID)
2171 			__set_bit(APIC_CLUSTERID(id), clustermap);
2172 	}
2173 
2174 	/* Problem:  Partially populated chassis may not have CPUs in some of
2175 	 * the APIC clusters they have been allocated.  Only present CPUs have
2176 	 * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap.
2177 	 * Since clusters are allocated sequentially, count zeros only if
2178 	 * they are bounded by ones.
2179 	 */
2180 	clusters = 0;
2181 	zeros = 0;
2182 	for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
2183 		if (test_bit(i, clustermap)) {
2184 			clusters += 1 + zeros;
2185 			zeros = 0;
2186 		} else
2187 			++zeros;
2188 	}
2189 
2190 	return clusters;
2191 }
2192 
2193 static int __cpuinitdata multi_checked;
2194 static int __cpuinitdata multi;
2195 
2196 static int __cpuinit set_multi(const struct dmi_system_id *d)
2197 {
2198 	if (multi)
2199 		return 0;
2200 	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2201 	multi = 1;
2202 	return 0;
2203 }
2204 
2205 static const __cpuinitconst struct dmi_system_id multi_dmi_table[] = {
2206 	{
2207 		.callback = set_multi,
2208 		.ident = "IBM System Summit2",
2209 		.matches = {
2210 			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2211 			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2212 		},
2213 	},
2214 	{}
2215 };
2216 
2217 static void __cpuinit dmi_check_multi(void)
2218 {
2219 	if (multi_checked)
2220 		return;
2221 
2222 	dmi_check_system(multi_dmi_table);
2223 	multi_checked = 1;
2224 }
2225 
2226 /*
2227  * apic_is_clustered_box() -- Check if we can expect good TSC
2228  *
2229  * Thus far, the major user of this is IBM's Summit2 series:
2230  * Clustered boxes may have unsynced TSC problems if they are
2231  * multi-chassis.
2232  * Use DMI to check them
2233  */
2234 __cpuinit int apic_is_clustered_box(void)
2235 {
2236 	dmi_check_multi();
2237 	if (multi)
2238 		return 1;
2239 
2240 	if (!is_vsmp_box())
2241 		return 0;
2242 
2243 	/*
2244 	 * ScaleMP vSMPowered boxes have one cluster per board and TSCs are
2245 	 * not guaranteed to be synced between boards
2246 	 */
2247 	if (apic_cluster_num() > 1)
2248 		return 1;
2249 
2250 	return 0;
2251 }
2252 #endif
2253 
2254 /*
2255  * APIC command line parameters
2256  */
2257 static int __init setup_disableapic(char *arg)
2258 {
2259 	disable_apic = 1;
2260 	setup_clear_cpu_cap(X86_FEATURE_APIC);
2261 	return 0;
2262 }
2263 early_param("disableapic", setup_disableapic);
2264 
2265 /* same as disableapic, for compatibility */
2266 static int __init setup_nolapic(char *arg)
2267 {
2268 	return setup_disableapic(arg);
2269 }
2270 early_param("nolapic", setup_nolapic);
2271 
2272 static int __init parse_lapic_timer_c2_ok(char *arg)
2273 {
2274 	local_apic_timer_c2_ok = 1;
2275 	return 0;
2276 }
2277 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2278 
2279 static int __init parse_disable_apic_timer(char *arg)
2280 {
2281 	disable_apic_timer = 1;
2282 	return 0;
2283 }
2284 early_param("noapictimer", parse_disable_apic_timer);
2285 
2286 static int __init parse_nolapic_timer(char *arg)
2287 {
2288 	disable_apic_timer = 1;
2289 	return 0;
2290 }
2291 early_param("nolapic_timer", parse_nolapic_timer);
2292 
2293 static int __init apic_set_verbosity(char *arg)
2294 {
2295 	if (!arg)  {
2296 #ifdef CONFIG_X86_64
2297 		skip_ioapic_setup = 0;
2298 		return 0;
2299 #endif
2300 		return -EINVAL;
2301 	}
2302 
2303 	if (strcmp("debug", arg) == 0)
2304 		apic_verbosity = APIC_DEBUG;
2305 	else if (strcmp("verbose", arg) == 0)
2306 		apic_verbosity = APIC_VERBOSE;
2307 	else {
2308 		pr_warning("APIC Verbosity level %s not recognised"
2309 			" use apic=verbose or apic=debug\n", arg);
2310 		return -EINVAL;
2311 	}
2312 
2313 	return 0;
2314 }
2315 early_param("apic", apic_set_verbosity);
2316 
2317 static int __init lapic_insert_resource(void)
2318 {
2319 	if (!apic_phys)
2320 		return -1;
2321 
2322 	/* Put local APIC into the resource map. */
2323 	lapic_resource.start = apic_phys;
2324 	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2325 	insert_resource(&iomem_resource, &lapic_resource);
2326 
2327 	return 0;
2328 }
2329 
2330 /*
2331  * need call insert after e820_reserve_resources()
2332  * that is using request_resource
2333  */
2334 late_initcall(lapic_insert_resource);
2335