xref: /linux/arch/x86/kernel/apic/apic.c (revision a67ff6a54095e27093ea501fb143fefe51a536c2)
1 /*
2  *	Local APIC handling, local APIC timers
3  *
4  *	(c) 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
5  *
6  *	Fixes
7  *	Maciej W. Rozycki	:	Bits for genuine 82489DX APICs;
8  *					thanks to Eric Gilmore
9  *					and Rolf G. Tews
10  *					for testing these extensively.
11  *	Maciej W. Rozycki	:	Various updates and fixes.
12  *	Mikael Pettersson	:	Power Management for UP-APIC.
13  *	Pavel Machek and
14  *	Mikael Pettersson	:	PM converted to driver model.
15  */
16 
17 #include <linux/perf_event.h>
18 #include <linux/kernel_stat.h>
19 #include <linux/mc146818rtc.h>
20 #include <linux/acpi_pmtmr.h>
21 #include <linux/clockchips.h>
22 #include <linux/interrupt.h>
23 #include <linux/bootmem.h>
24 #include <linux/ftrace.h>
25 #include <linux/ioport.h>
26 #include <linux/module.h>
27 #include <linux/syscore_ops.h>
28 #include <linux/delay.h>
29 #include <linux/timex.h>
30 #include <linux/i8253.h>
31 #include <linux/dmar.h>
32 #include <linux/init.h>
33 #include <linux/cpu.h>
34 #include <linux/dmi.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 <linux/atomic.h>
42 #include <asm/mpspec.h>
43 #include <asm/i8259.h>
44 #include <asm/proto.h>
45 #include <asm/apic.h>
46 #include <asm/io_apic.h>
47 #include <asm/desc.h>
48 #include <asm/hpet.h>
49 #include <asm/idle.h>
50 #include <asm/mtrr.h>
51 #include <asm/time.h>
52 #include <asm/smp.h>
53 #include <asm/mce.h>
54 #include <asm/tsc.h>
55 #include <asm/hypervisor.h>
56 
57 unsigned int num_processors;
58 
59 unsigned disabled_cpus __cpuinitdata;
60 
61 /* Processor that is doing the boot up */
62 unsigned int boot_cpu_physical_apicid = -1U;
63 
64 /*
65  * The highest APIC ID seen during enumeration.
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 /*
85  * On x86_32, the mapping between cpu and logical apicid may vary
86  * depending on apic in use.  The following early percpu variable is
87  * used for the mapping.  This is where the behaviors of x86_64 and 32
88  * actually diverge.  Let's keep it ugly for now.
89  */
90 DEFINE_EARLY_PER_CPU(int, x86_cpu_to_logical_apicid, BAD_APICID);
91 
92 /*
93  * Knob to control our willingness to enable the local APIC.
94  *
95  * +1=force-enable
96  */
97 static int force_enable_local_apic __initdata;
98 /*
99  * APIC command line parameters
100  */
101 static int __init parse_lapic(char *arg)
102 {
103 	force_enable_local_apic = 1;
104 	return 0;
105 }
106 early_param("lapic", parse_lapic);
107 /* Local APIC was disabled by the BIOS and enabled by the kernel */
108 static int enabled_via_apicbase;
109 
110 /*
111  * Handle interrupt mode configuration register (IMCR).
112  * This register controls whether the interrupt signals
113  * that reach the BSP come from the master PIC or from the
114  * local APIC. Before entering Symmetric I/O Mode, either
115  * the BIOS or the operating system must switch out of
116  * PIC Mode by changing the IMCR.
117  */
118 static inline void imcr_pic_to_apic(void)
119 {
120 	/* select IMCR register */
121 	outb(0x70, 0x22);
122 	/* NMI and 8259 INTR go through APIC */
123 	outb(0x01, 0x23);
124 }
125 
126 static inline void imcr_apic_to_pic(void)
127 {
128 	/* select IMCR register */
129 	outb(0x70, 0x22);
130 	/* NMI and 8259 INTR go directly to BSP */
131 	outb(0x00, 0x23);
132 }
133 #endif
134 
135 #ifdef CONFIG_X86_64
136 static int apic_calibrate_pmtmr __initdata;
137 static __init int setup_apicpmtimer(char *s)
138 {
139 	apic_calibrate_pmtmr = 1;
140 	notsc_setup(NULL);
141 	return 0;
142 }
143 __setup("apicpmtimer", setup_apicpmtimer);
144 #endif
145 
146 int x2apic_mode;
147 #ifdef CONFIG_X86_X2APIC
148 /* x2apic enabled before OS handover */
149 static int x2apic_preenabled;
150 static __init int setup_nox2apic(char *str)
151 {
152 	if (x2apic_enabled()) {
153 		pr_warning("Bios already enabled x2apic, "
154 			   "can't enforce nox2apic");
155 		return 0;
156 	}
157 
158 	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
159 	return 0;
160 }
161 early_param("nox2apic", setup_nox2apic);
162 #endif
163 
164 unsigned long mp_lapic_addr;
165 int disable_apic;
166 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
167 static int disable_apic_timer __initdata;
168 /* Local APIC timer works in C2 */
169 int local_apic_timer_c2_ok;
170 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
171 
172 int first_system_vector = 0xfe;
173 
174 /*
175  * Debug level, exported for io_apic.c
176  */
177 unsigned int apic_verbosity;
178 
179 int pic_mode;
180 
181 /* Have we found an MP table */
182 int smp_found_config;
183 
184 static struct resource lapic_resource = {
185 	.name = "Local APIC",
186 	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
187 };
188 
189 static unsigned int calibration_result;
190 
191 static void apic_pm_activate(void);
192 
193 static unsigned long apic_phys;
194 
195 /*
196  * Get the LAPIC version
197  */
198 static inline int lapic_get_version(void)
199 {
200 	return GET_APIC_VERSION(apic_read(APIC_LVR));
201 }
202 
203 /*
204  * Check, if the APIC is integrated or a separate chip
205  */
206 static inline int lapic_is_integrated(void)
207 {
208 #ifdef CONFIG_X86_64
209 	return 1;
210 #else
211 	return APIC_INTEGRATED(lapic_get_version());
212 #endif
213 }
214 
215 /*
216  * Check, whether this is a modern or a first generation APIC
217  */
218 static int modern_apic(void)
219 {
220 	/* AMD systems use old APIC versions, so check the CPU */
221 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
222 	    boot_cpu_data.x86 >= 0xf)
223 		return 1;
224 	return lapic_get_version() >= 0x14;
225 }
226 
227 /*
228  * right after this call apic become NOOP driven
229  * so apic->write/read doesn't do anything
230  */
231 static void __init apic_disable(void)
232 {
233 	pr_info("APIC: switched to apic NOOP\n");
234 	apic = &apic_noop;
235 }
236 
237 void native_apic_wait_icr_idle(void)
238 {
239 	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
240 		cpu_relax();
241 }
242 
243 u32 native_safe_apic_wait_icr_idle(void)
244 {
245 	u32 send_status;
246 	int timeout;
247 
248 	timeout = 0;
249 	do {
250 		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
251 		if (!send_status)
252 			break;
253 		udelay(100);
254 	} while (timeout++ < 1000);
255 
256 	return send_status;
257 }
258 
259 void native_apic_icr_write(u32 low, u32 id)
260 {
261 	apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
262 	apic_write(APIC_ICR, low);
263 }
264 
265 u64 native_apic_icr_read(void)
266 {
267 	u32 icr1, icr2;
268 
269 	icr2 = apic_read(APIC_ICR2);
270 	icr1 = apic_read(APIC_ICR);
271 
272 	return icr1 | ((u64)icr2 << 32);
273 }
274 
275 #ifdef CONFIG_X86_32
276 /**
277  * get_physical_broadcast - Get number of physical broadcast IDs
278  */
279 int get_physical_broadcast(void)
280 {
281 	return modern_apic() ? 0xff : 0xf;
282 }
283 #endif
284 
285 /**
286  * lapic_get_maxlvt - get the maximum number of local vector table entries
287  */
288 int lapic_get_maxlvt(void)
289 {
290 	unsigned int v;
291 
292 	v = apic_read(APIC_LVR);
293 	/*
294 	 * - we always have APIC integrated on 64bit mode
295 	 * - 82489DXs do not report # of LVT entries
296 	 */
297 	return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
298 }
299 
300 /*
301  * Local APIC timer
302  */
303 
304 /* Clock divisor */
305 #define APIC_DIVISOR 16
306 
307 /*
308  * This function sets up the local APIC timer, with a timeout of
309  * 'clocks' APIC bus clock. During calibration we actually call
310  * this function twice on the boot CPU, once with a bogus timeout
311  * value, second time for real. The other (noncalibrating) CPUs
312  * call this function only once, with the real, calibrated value.
313  *
314  * We do reads before writes even if unnecessary, to get around the
315  * P5 APIC double write bug.
316  */
317 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
318 {
319 	unsigned int lvtt_value, tmp_value;
320 
321 	lvtt_value = LOCAL_TIMER_VECTOR;
322 	if (!oneshot)
323 		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
324 	if (!lapic_is_integrated())
325 		lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
326 
327 	if (!irqen)
328 		lvtt_value |= APIC_LVT_MASKED;
329 
330 	apic_write(APIC_LVTT, lvtt_value);
331 
332 	/*
333 	 * Divide PICLK by 16
334 	 */
335 	tmp_value = apic_read(APIC_TDCR);
336 	apic_write(APIC_TDCR,
337 		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
338 		APIC_TDR_DIV_16);
339 
340 	if (!oneshot)
341 		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
342 }
343 
344 /*
345  * Setup extended LVT, AMD specific
346  *
347  * Software should use the LVT offsets the BIOS provides.  The offsets
348  * are determined by the subsystems using it like those for MCE
349  * threshold or IBS.  On K8 only offset 0 (APIC500) and MCE interrupts
350  * are supported. Beginning with family 10h at least 4 offsets are
351  * available.
352  *
353  * Since the offsets must be consistent for all cores, we keep track
354  * of the LVT offsets in software and reserve the offset for the same
355  * vector also to be used on other cores. An offset is freed by
356  * setting the entry to APIC_EILVT_MASKED.
357  *
358  * If the BIOS is right, there should be no conflicts. Otherwise a
359  * "[Firmware Bug]: ..." error message is generated. However, if
360  * software does not properly determines the offsets, it is not
361  * necessarily a BIOS bug.
362  */
363 
364 static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
365 
366 static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
367 {
368 	return (old & APIC_EILVT_MASKED)
369 		|| (new == APIC_EILVT_MASKED)
370 		|| ((new & ~APIC_EILVT_MASKED) == old);
371 }
372 
373 static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
374 {
375 	unsigned int rsvd;			/* 0: uninitialized */
376 
377 	if (offset >= APIC_EILVT_NR_MAX)
378 		return ~0;
379 
380 	rsvd = atomic_read(&eilvt_offsets[offset]) & ~APIC_EILVT_MASKED;
381 	do {
382 		if (rsvd &&
383 		    !eilvt_entry_is_changeable(rsvd, new))
384 			/* may not change if vectors are different */
385 			return rsvd;
386 		rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new);
387 	} while (rsvd != new);
388 
389 	return new;
390 }
391 
392 /*
393  * If mask=1, the LVT entry does not generate interrupts while mask=0
394  * enables the vector. See also the BKDGs. Must be called with
395  * preemption disabled.
396  */
397 
398 int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
399 {
400 	unsigned long reg = APIC_EILVTn(offset);
401 	unsigned int new, old, reserved;
402 
403 	new = (mask << 16) | (msg_type << 8) | vector;
404 	old = apic_read(reg);
405 	reserved = reserve_eilvt_offset(offset, new);
406 
407 	if (reserved != new) {
408 		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
409 		       "vector 0x%x, but the register is already in use for "
410 		       "vector 0x%x on another cpu\n",
411 		       smp_processor_id(), reg, offset, new, reserved);
412 		return -EINVAL;
413 	}
414 
415 	if (!eilvt_entry_is_changeable(old, new)) {
416 		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
417 		       "vector 0x%x, but the register is already in use for "
418 		       "vector 0x%x on this cpu\n",
419 		       smp_processor_id(), reg, offset, new, old);
420 		return -EBUSY;
421 	}
422 
423 	apic_write(reg, new);
424 
425 	return 0;
426 }
427 EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
428 
429 /*
430  * Program the next event, relative to now
431  */
432 static int lapic_next_event(unsigned long delta,
433 			    struct clock_event_device *evt)
434 {
435 	apic_write(APIC_TMICT, delta);
436 	return 0;
437 }
438 
439 /*
440  * Setup the lapic timer in periodic or oneshot mode
441  */
442 static void lapic_timer_setup(enum clock_event_mode mode,
443 			      struct clock_event_device *evt)
444 {
445 	unsigned long flags;
446 	unsigned int v;
447 
448 	/* Lapic used as dummy for broadcast ? */
449 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
450 		return;
451 
452 	local_irq_save(flags);
453 
454 	switch (mode) {
455 	case CLOCK_EVT_MODE_PERIODIC:
456 	case CLOCK_EVT_MODE_ONESHOT:
457 		__setup_APIC_LVTT(calibration_result,
458 				  mode != CLOCK_EVT_MODE_PERIODIC, 1);
459 		break;
460 	case CLOCK_EVT_MODE_UNUSED:
461 	case CLOCK_EVT_MODE_SHUTDOWN:
462 		v = apic_read(APIC_LVTT);
463 		v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
464 		apic_write(APIC_LVTT, v);
465 		apic_write(APIC_TMICT, 0);
466 		break;
467 	case CLOCK_EVT_MODE_RESUME:
468 		/* Nothing to do here */
469 		break;
470 	}
471 
472 	local_irq_restore(flags);
473 }
474 
475 /*
476  * Local APIC timer broadcast function
477  */
478 static void lapic_timer_broadcast(const struct cpumask *mask)
479 {
480 #ifdef CONFIG_SMP
481 	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
482 #endif
483 }
484 
485 
486 /*
487  * The local apic timer can be used for any function which is CPU local.
488  */
489 static struct clock_event_device lapic_clockevent = {
490 	.name		= "lapic",
491 	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
492 			| CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
493 	.shift		= 32,
494 	.set_mode	= lapic_timer_setup,
495 	.set_next_event	= lapic_next_event,
496 	.broadcast	= lapic_timer_broadcast,
497 	.rating		= 100,
498 	.irq		= -1,
499 };
500 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
501 
502 /*
503  * Setup the local APIC timer for this CPU. Copy the initialized values
504  * of the boot CPU and register the clock event in the framework.
505  */
506 static void __cpuinit setup_APIC_timer(void)
507 {
508 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
509 
510 	if (this_cpu_has(X86_FEATURE_ARAT)) {
511 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
512 		/* Make LAPIC timer preferrable over percpu HPET */
513 		lapic_clockevent.rating = 150;
514 	}
515 
516 	memcpy(levt, &lapic_clockevent, sizeof(*levt));
517 	levt->cpumask = cpumask_of(smp_processor_id());
518 
519 	clockevents_register_device(levt);
520 }
521 
522 /*
523  * In this functions we calibrate APIC bus clocks to the external timer.
524  *
525  * We want to do the calibration only once since we want to have local timer
526  * irqs syncron. CPUs connected by the same APIC bus have the very same bus
527  * frequency.
528  *
529  * This was previously done by reading the PIT/HPET and waiting for a wrap
530  * around to find out, that a tick has elapsed. I have a box, where the PIT
531  * readout is broken, so it never gets out of the wait loop again. This was
532  * also reported by others.
533  *
534  * Monitoring the jiffies value is inaccurate and the clockevents
535  * infrastructure allows us to do a simple substitution of the interrupt
536  * handler.
537  *
538  * The calibration routine also uses the pm_timer when possible, as the PIT
539  * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
540  * back to normal later in the boot process).
541  */
542 
543 #define LAPIC_CAL_LOOPS		(HZ/10)
544 
545 static __initdata int lapic_cal_loops = -1;
546 static __initdata long lapic_cal_t1, lapic_cal_t2;
547 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
548 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
549 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
550 
551 /*
552  * Temporary interrupt handler.
553  */
554 static void __init lapic_cal_handler(struct clock_event_device *dev)
555 {
556 	unsigned long long tsc = 0;
557 	long tapic = apic_read(APIC_TMCCT);
558 	unsigned long pm = acpi_pm_read_early();
559 
560 	if (cpu_has_tsc)
561 		rdtscll(tsc);
562 
563 	switch (lapic_cal_loops++) {
564 	case 0:
565 		lapic_cal_t1 = tapic;
566 		lapic_cal_tsc1 = tsc;
567 		lapic_cal_pm1 = pm;
568 		lapic_cal_j1 = jiffies;
569 		break;
570 
571 	case LAPIC_CAL_LOOPS:
572 		lapic_cal_t2 = tapic;
573 		lapic_cal_tsc2 = tsc;
574 		if (pm < lapic_cal_pm1)
575 			pm += ACPI_PM_OVRRUN;
576 		lapic_cal_pm2 = pm;
577 		lapic_cal_j2 = jiffies;
578 		break;
579 	}
580 }
581 
582 static int __init
583 calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
584 {
585 	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
586 	const long pm_thresh = pm_100ms / 100;
587 	unsigned long mult;
588 	u64 res;
589 
590 #ifndef CONFIG_X86_PM_TIMER
591 	return -1;
592 #endif
593 
594 	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
595 
596 	/* Check, if the PM timer is available */
597 	if (!deltapm)
598 		return -1;
599 
600 	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
601 
602 	if (deltapm > (pm_100ms - pm_thresh) &&
603 	    deltapm < (pm_100ms + pm_thresh)) {
604 		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
605 		return 0;
606 	}
607 
608 	res = (((u64)deltapm) *  mult) >> 22;
609 	do_div(res, 1000000);
610 	pr_warning("APIC calibration not consistent "
611 		   "with PM-Timer: %ldms instead of 100ms\n",(long)res);
612 
613 	/* Correct the lapic counter value */
614 	res = (((u64)(*delta)) * pm_100ms);
615 	do_div(res, deltapm);
616 	pr_info("APIC delta adjusted to PM-Timer: "
617 		"%lu (%ld)\n", (unsigned long)res, *delta);
618 	*delta = (long)res;
619 
620 	/* Correct the tsc counter value */
621 	if (cpu_has_tsc) {
622 		res = (((u64)(*deltatsc)) * pm_100ms);
623 		do_div(res, deltapm);
624 		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
625 					  "PM-Timer: %lu (%ld)\n",
626 					(unsigned long)res, *deltatsc);
627 		*deltatsc = (long)res;
628 	}
629 
630 	return 0;
631 }
632 
633 static int __init calibrate_APIC_clock(void)
634 {
635 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
636 	void (*real_handler)(struct clock_event_device *dev);
637 	unsigned long deltaj;
638 	long delta, deltatsc;
639 	int pm_referenced = 0;
640 
641 	local_irq_disable();
642 
643 	/* Replace the global interrupt handler */
644 	real_handler = global_clock_event->event_handler;
645 	global_clock_event->event_handler = lapic_cal_handler;
646 
647 	/*
648 	 * Setup the APIC counter to maximum. There is no way the lapic
649 	 * can underflow in the 100ms detection time frame
650 	 */
651 	__setup_APIC_LVTT(0xffffffff, 0, 0);
652 
653 	/* Let the interrupts run */
654 	local_irq_enable();
655 
656 	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
657 		cpu_relax();
658 
659 	local_irq_disable();
660 
661 	/* Restore the real event handler */
662 	global_clock_event->event_handler = real_handler;
663 
664 	/* Build delta t1-t2 as apic timer counts down */
665 	delta = lapic_cal_t1 - lapic_cal_t2;
666 	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
667 
668 	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
669 
670 	/* we trust the PM based calibration if possible */
671 	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
672 					&delta, &deltatsc);
673 
674 	/* Calculate the scaled math multiplication factor */
675 	lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
676 				       lapic_clockevent.shift);
677 	lapic_clockevent.max_delta_ns =
678 		clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
679 	lapic_clockevent.min_delta_ns =
680 		clockevent_delta2ns(0xF, &lapic_clockevent);
681 
682 	calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
683 
684 	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
685 	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
686 	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
687 		    calibration_result);
688 
689 	if (cpu_has_tsc) {
690 		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
691 			    "%ld.%04ld MHz.\n",
692 			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
693 			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
694 	}
695 
696 	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
697 		    "%u.%04u MHz.\n",
698 		    calibration_result / (1000000 / HZ),
699 		    calibration_result % (1000000 / HZ));
700 
701 	/*
702 	 * Do a sanity check on the APIC calibration result
703 	 */
704 	if (calibration_result < (1000000 / HZ)) {
705 		local_irq_enable();
706 		pr_warning("APIC frequency too slow, disabling apic timer\n");
707 		return -1;
708 	}
709 
710 	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
711 
712 	/*
713 	 * PM timer calibration failed or not turned on
714 	 * so lets try APIC timer based calibration
715 	 */
716 	if (!pm_referenced) {
717 		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
718 
719 		/*
720 		 * Setup the apic timer manually
721 		 */
722 		levt->event_handler = lapic_cal_handler;
723 		lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
724 		lapic_cal_loops = -1;
725 
726 		/* Let the interrupts run */
727 		local_irq_enable();
728 
729 		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
730 			cpu_relax();
731 
732 		/* Stop the lapic timer */
733 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
734 
735 		/* Jiffies delta */
736 		deltaj = lapic_cal_j2 - lapic_cal_j1;
737 		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
738 
739 		/* Check, if the jiffies result is consistent */
740 		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
741 			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
742 		else
743 			levt->features |= CLOCK_EVT_FEAT_DUMMY;
744 	} else
745 		local_irq_enable();
746 
747 	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
748 		pr_warning("APIC timer disabled due to verification failure\n");
749 			return -1;
750 	}
751 
752 	return 0;
753 }
754 
755 /*
756  * Setup the boot APIC
757  *
758  * Calibrate and verify the result.
759  */
760 void __init setup_boot_APIC_clock(void)
761 {
762 	/*
763 	 * The local apic timer can be disabled via the kernel
764 	 * commandline or from the CPU detection code. Register the lapic
765 	 * timer as a dummy clock event source on SMP systems, so the
766 	 * broadcast mechanism is used. On UP systems simply ignore it.
767 	 */
768 	if (disable_apic_timer) {
769 		pr_info("Disabling APIC timer\n");
770 		/* No broadcast on UP ! */
771 		if (num_possible_cpus() > 1) {
772 			lapic_clockevent.mult = 1;
773 			setup_APIC_timer();
774 		}
775 		return;
776 	}
777 
778 	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
779 		    "calibrating APIC timer ...\n");
780 
781 	if (calibrate_APIC_clock()) {
782 		/* No broadcast on UP ! */
783 		if (num_possible_cpus() > 1)
784 			setup_APIC_timer();
785 		return;
786 	}
787 
788 	/*
789 	 * If nmi_watchdog is set to IO_APIC, we need the
790 	 * PIT/HPET going.  Otherwise register lapic as a dummy
791 	 * device.
792 	 */
793 	lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
794 
795 	/* Setup the lapic or request the broadcast */
796 	setup_APIC_timer();
797 }
798 
799 void __cpuinit setup_secondary_APIC_clock(void)
800 {
801 	setup_APIC_timer();
802 }
803 
804 /*
805  * The guts of the apic timer interrupt
806  */
807 static void local_apic_timer_interrupt(void)
808 {
809 	int cpu = smp_processor_id();
810 	struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
811 
812 	/*
813 	 * Normally we should not be here till LAPIC has been initialized but
814 	 * in some cases like kdump, its possible that there is a pending LAPIC
815 	 * timer interrupt from previous kernel's context and is delivered in
816 	 * new kernel the moment interrupts are enabled.
817 	 *
818 	 * Interrupts are enabled early and LAPIC is setup much later, hence
819 	 * its possible that when we get here evt->event_handler is NULL.
820 	 * Check for event_handler being NULL and discard the interrupt as
821 	 * spurious.
822 	 */
823 	if (!evt->event_handler) {
824 		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu);
825 		/* Switch it off */
826 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
827 		return;
828 	}
829 
830 	/*
831 	 * the NMI deadlock-detector uses this.
832 	 */
833 	inc_irq_stat(apic_timer_irqs);
834 
835 	evt->event_handler(evt);
836 }
837 
838 /*
839  * Local APIC timer interrupt. This is the most natural way for doing
840  * local interrupts, but local timer interrupts can be emulated by
841  * broadcast interrupts too. [in case the hw doesn't support APIC timers]
842  *
843  * [ if a single-CPU system runs an SMP kernel then we call the local
844  *   interrupt as well. Thus we cannot inline the local irq ... ]
845  */
846 void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
847 {
848 	struct pt_regs *old_regs = set_irq_regs(regs);
849 
850 	/*
851 	 * NOTE! We'd better ACK the irq immediately,
852 	 * because timer handling can be slow.
853 	 */
854 	ack_APIC_irq();
855 	/*
856 	 * update_process_times() expects us to have done irq_enter().
857 	 * Besides, if we don't timer interrupts ignore the global
858 	 * interrupt lock, which is the WrongThing (tm) to do.
859 	 */
860 	exit_idle();
861 	irq_enter();
862 	local_apic_timer_interrupt();
863 	irq_exit();
864 
865 	set_irq_regs(old_regs);
866 }
867 
868 int setup_profiling_timer(unsigned int multiplier)
869 {
870 	return -EINVAL;
871 }
872 
873 /*
874  * Local APIC start and shutdown
875  */
876 
877 /**
878  * clear_local_APIC - shutdown the local APIC
879  *
880  * This is called, when a CPU is disabled and before rebooting, so the state of
881  * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
882  * leftovers during boot.
883  */
884 void clear_local_APIC(void)
885 {
886 	int maxlvt;
887 	u32 v;
888 
889 	/* APIC hasn't been mapped yet */
890 	if (!x2apic_mode && !apic_phys)
891 		return;
892 
893 	maxlvt = lapic_get_maxlvt();
894 	/*
895 	 * Masking an LVT entry can trigger a local APIC error
896 	 * if the vector is zero. Mask LVTERR first to prevent this.
897 	 */
898 	if (maxlvt >= 3) {
899 		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
900 		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
901 	}
902 	/*
903 	 * Careful: we have to set masks only first to deassert
904 	 * any level-triggered sources.
905 	 */
906 	v = apic_read(APIC_LVTT);
907 	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
908 	v = apic_read(APIC_LVT0);
909 	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
910 	v = apic_read(APIC_LVT1);
911 	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
912 	if (maxlvt >= 4) {
913 		v = apic_read(APIC_LVTPC);
914 		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
915 	}
916 
917 	/* lets not touch this if we didn't frob it */
918 #ifdef CONFIG_X86_THERMAL_VECTOR
919 	if (maxlvt >= 5) {
920 		v = apic_read(APIC_LVTTHMR);
921 		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
922 	}
923 #endif
924 #ifdef CONFIG_X86_MCE_INTEL
925 	if (maxlvt >= 6) {
926 		v = apic_read(APIC_LVTCMCI);
927 		if (!(v & APIC_LVT_MASKED))
928 			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
929 	}
930 #endif
931 
932 	/*
933 	 * Clean APIC state for other OSs:
934 	 */
935 	apic_write(APIC_LVTT, APIC_LVT_MASKED);
936 	apic_write(APIC_LVT0, APIC_LVT_MASKED);
937 	apic_write(APIC_LVT1, APIC_LVT_MASKED);
938 	if (maxlvt >= 3)
939 		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
940 	if (maxlvt >= 4)
941 		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
942 
943 	/* Integrated APIC (!82489DX) ? */
944 	if (lapic_is_integrated()) {
945 		if (maxlvt > 3)
946 			/* Clear ESR due to Pentium errata 3AP and 11AP */
947 			apic_write(APIC_ESR, 0);
948 		apic_read(APIC_ESR);
949 	}
950 }
951 
952 /**
953  * disable_local_APIC - clear and disable the local APIC
954  */
955 void disable_local_APIC(void)
956 {
957 	unsigned int value;
958 
959 	/* APIC hasn't been mapped yet */
960 	if (!x2apic_mode && !apic_phys)
961 		return;
962 
963 	clear_local_APIC();
964 
965 	/*
966 	 * Disable APIC (implies clearing of registers
967 	 * for 82489DX!).
968 	 */
969 	value = apic_read(APIC_SPIV);
970 	value &= ~APIC_SPIV_APIC_ENABLED;
971 	apic_write(APIC_SPIV, value);
972 
973 #ifdef CONFIG_X86_32
974 	/*
975 	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
976 	 * restore the disabled state.
977 	 */
978 	if (enabled_via_apicbase) {
979 		unsigned int l, h;
980 
981 		rdmsr(MSR_IA32_APICBASE, l, h);
982 		l &= ~MSR_IA32_APICBASE_ENABLE;
983 		wrmsr(MSR_IA32_APICBASE, l, h);
984 	}
985 #endif
986 }
987 
988 /*
989  * If Linux enabled the LAPIC against the BIOS default disable it down before
990  * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
991  * not power-off.  Additionally clear all LVT entries before disable_local_APIC
992  * for the case where Linux didn't enable the LAPIC.
993  */
994 void lapic_shutdown(void)
995 {
996 	unsigned long flags;
997 
998 	if (!cpu_has_apic && !apic_from_smp_config())
999 		return;
1000 
1001 	local_irq_save(flags);
1002 
1003 #ifdef CONFIG_X86_32
1004 	if (!enabled_via_apicbase)
1005 		clear_local_APIC();
1006 	else
1007 #endif
1008 		disable_local_APIC();
1009 
1010 
1011 	local_irq_restore(flags);
1012 }
1013 
1014 /*
1015  * This is to verify that we're looking at a real local APIC.
1016  * Check these against your board if the CPUs aren't getting
1017  * started for no apparent reason.
1018  */
1019 int __init verify_local_APIC(void)
1020 {
1021 	unsigned int reg0, reg1;
1022 
1023 	/*
1024 	 * The version register is read-only in a real APIC.
1025 	 */
1026 	reg0 = apic_read(APIC_LVR);
1027 	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
1028 	apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
1029 	reg1 = apic_read(APIC_LVR);
1030 	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
1031 
1032 	/*
1033 	 * The two version reads above should print the same
1034 	 * numbers.  If the second one is different, then we
1035 	 * poke at a non-APIC.
1036 	 */
1037 	if (reg1 != reg0)
1038 		return 0;
1039 
1040 	/*
1041 	 * Check if the version looks reasonably.
1042 	 */
1043 	reg1 = GET_APIC_VERSION(reg0);
1044 	if (reg1 == 0x00 || reg1 == 0xff)
1045 		return 0;
1046 	reg1 = lapic_get_maxlvt();
1047 	if (reg1 < 0x02 || reg1 == 0xff)
1048 		return 0;
1049 
1050 	/*
1051 	 * The ID register is read/write in a real APIC.
1052 	 */
1053 	reg0 = apic_read(APIC_ID);
1054 	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
1055 	apic_write(APIC_ID, reg0 ^ apic->apic_id_mask);
1056 	reg1 = apic_read(APIC_ID);
1057 	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
1058 	apic_write(APIC_ID, reg0);
1059 	if (reg1 != (reg0 ^ apic->apic_id_mask))
1060 		return 0;
1061 
1062 	/*
1063 	 * The next two are just to see if we have sane values.
1064 	 * They're only really relevant if we're in Virtual Wire
1065 	 * compatibility mode, but most boxes are anymore.
1066 	 */
1067 	reg0 = apic_read(APIC_LVT0);
1068 	apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
1069 	reg1 = apic_read(APIC_LVT1);
1070 	apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
1071 
1072 	return 1;
1073 }
1074 
1075 /**
1076  * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1077  */
1078 void __init sync_Arb_IDs(void)
1079 {
1080 	/*
1081 	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1082 	 * needed on AMD.
1083 	 */
1084 	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1085 		return;
1086 
1087 	/*
1088 	 * Wait for idle.
1089 	 */
1090 	apic_wait_icr_idle();
1091 
1092 	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1093 	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1094 			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1095 }
1096 
1097 /*
1098  * An initial setup of the virtual wire mode.
1099  */
1100 void __init init_bsp_APIC(void)
1101 {
1102 	unsigned int value;
1103 
1104 	/*
1105 	 * Don't do the setup now if we have a SMP BIOS as the
1106 	 * through-I/O-APIC virtual wire mode might be active.
1107 	 */
1108 	if (smp_found_config || !cpu_has_apic)
1109 		return;
1110 
1111 	/*
1112 	 * Do not trust the local APIC being empty at bootup.
1113 	 */
1114 	clear_local_APIC();
1115 
1116 	/*
1117 	 * Enable APIC.
1118 	 */
1119 	value = apic_read(APIC_SPIV);
1120 	value &= ~APIC_VECTOR_MASK;
1121 	value |= APIC_SPIV_APIC_ENABLED;
1122 
1123 #ifdef CONFIG_X86_32
1124 	/* This bit is reserved on P4/Xeon and should be cleared */
1125 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1126 	    (boot_cpu_data.x86 == 15))
1127 		value &= ~APIC_SPIV_FOCUS_DISABLED;
1128 	else
1129 #endif
1130 		value |= APIC_SPIV_FOCUS_DISABLED;
1131 	value |= SPURIOUS_APIC_VECTOR;
1132 	apic_write(APIC_SPIV, value);
1133 
1134 	/*
1135 	 * Set up the virtual wire mode.
1136 	 */
1137 	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1138 	value = APIC_DM_NMI;
1139 	if (!lapic_is_integrated())		/* 82489DX */
1140 		value |= APIC_LVT_LEVEL_TRIGGER;
1141 	apic_write(APIC_LVT1, value);
1142 }
1143 
1144 static void __cpuinit lapic_setup_esr(void)
1145 {
1146 	unsigned int oldvalue, value, maxlvt;
1147 
1148 	if (!lapic_is_integrated()) {
1149 		pr_info("No ESR for 82489DX.\n");
1150 		return;
1151 	}
1152 
1153 	if (apic->disable_esr) {
1154 		/*
1155 		 * Something untraceable is creating bad interrupts on
1156 		 * secondary quads ... for the moment, just leave the
1157 		 * ESR disabled - we can't do anything useful with the
1158 		 * errors anyway - mbligh
1159 		 */
1160 		pr_info("Leaving ESR disabled.\n");
1161 		return;
1162 	}
1163 
1164 	maxlvt = lapic_get_maxlvt();
1165 	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1166 		apic_write(APIC_ESR, 0);
1167 	oldvalue = apic_read(APIC_ESR);
1168 
1169 	/* enables sending errors */
1170 	value = ERROR_APIC_VECTOR;
1171 	apic_write(APIC_LVTERR, value);
1172 
1173 	/*
1174 	 * spec says clear errors after enabling vector.
1175 	 */
1176 	if (maxlvt > 3)
1177 		apic_write(APIC_ESR, 0);
1178 	value = apic_read(APIC_ESR);
1179 	if (value != oldvalue)
1180 		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1181 			"vector: 0x%08x  after: 0x%08x\n",
1182 			oldvalue, value);
1183 }
1184 
1185 /**
1186  * setup_local_APIC - setup the local APIC
1187  *
1188  * Used to setup local APIC while initializing BSP or bringin up APs.
1189  * Always called with preemption disabled.
1190  */
1191 void __cpuinit setup_local_APIC(void)
1192 {
1193 	int cpu = smp_processor_id();
1194 	unsigned int value, queued;
1195 	int i, j, acked = 0;
1196 	unsigned long long tsc = 0, ntsc;
1197 	long long max_loops = cpu_khz;
1198 
1199 	if (cpu_has_tsc)
1200 		rdtscll(tsc);
1201 
1202 	if (disable_apic) {
1203 		disable_ioapic_support();
1204 		return;
1205 	}
1206 
1207 #ifdef CONFIG_X86_32
1208 	/* Pound the ESR really hard over the head with a big hammer - mbligh */
1209 	if (lapic_is_integrated() && apic->disable_esr) {
1210 		apic_write(APIC_ESR, 0);
1211 		apic_write(APIC_ESR, 0);
1212 		apic_write(APIC_ESR, 0);
1213 		apic_write(APIC_ESR, 0);
1214 	}
1215 #endif
1216 	perf_events_lapic_init();
1217 
1218 	/*
1219 	 * Double-check whether this APIC is really registered.
1220 	 * This is meaningless in clustered apic mode, so we skip it.
1221 	 */
1222 	BUG_ON(!apic->apic_id_registered());
1223 
1224 	/*
1225 	 * Intel recommends to set DFR, LDR and TPR before enabling
1226 	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
1227 	 * document number 292116).  So here it goes...
1228 	 */
1229 	apic->init_apic_ldr();
1230 
1231 #ifdef CONFIG_X86_32
1232 	/*
1233 	 * APIC LDR is initialized.  If logical_apicid mapping was
1234 	 * initialized during get_smp_config(), make sure it matches the
1235 	 * actual value.
1236 	 */
1237 	i = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
1238 	WARN_ON(i != BAD_APICID && i != logical_smp_processor_id());
1239 	/* always use the value from LDR */
1240 	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
1241 		logical_smp_processor_id();
1242 
1243 	/*
1244 	 * Some NUMA implementations (NUMAQ) don't initialize apicid to
1245 	 * node mapping during NUMA init.  Now that logical apicid is
1246 	 * guaranteed to be known, give it another chance.  This is already
1247 	 * a bit too late - percpu allocation has already happened without
1248 	 * proper NUMA affinity.
1249 	 */
1250 	if (apic->x86_32_numa_cpu_node)
1251 		set_apicid_to_node(early_per_cpu(x86_cpu_to_apicid, cpu),
1252 				   apic->x86_32_numa_cpu_node(cpu));
1253 #endif
1254 
1255 	/*
1256 	 * Set Task Priority to 'accept all'. We never change this
1257 	 * later on.
1258 	 */
1259 	value = apic_read(APIC_TASKPRI);
1260 	value &= ~APIC_TPRI_MASK;
1261 	apic_write(APIC_TASKPRI, value);
1262 
1263 	/*
1264 	 * After a crash, we no longer service the interrupts and a pending
1265 	 * interrupt from previous kernel might still have ISR bit set.
1266 	 *
1267 	 * Most probably by now CPU has serviced that pending interrupt and
1268 	 * it might not have done the ack_APIC_irq() because it thought,
1269 	 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1270 	 * does not clear the ISR bit and cpu thinks it has already serivced
1271 	 * the interrupt. Hence a vector might get locked. It was noticed
1272 	 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1273 	 */
1274 	do {
1275 		queued = 0;
1276 		for (i = APIC_ISR_NR - 1; i >= 0; i--)
1277 			queued |= apic_read(APIC_IRR + i*0x10);
1278 
1279 		for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1280 			value = apic_read(APIC_ISR + i*0x10);
1281 			for (j = 31; j >= 0; j--) {
1282 				if (value & (1<<j)) {
1283 					ack_APIC_irq();
1284 					acked++;
1285 				}
1286 			}
1287 		}
1288 		if (acked > 256) {
1289 			printk(KERN_ERR "LAPIC pending interrupts after %d EOI\n",
1290 			       acked);
1291 			break;
1292 		}
1293 		if (cpu_has_tsc) {
1294 			rdtscll(ntsc);
1295 			max_loops = (cpu_khz << 10) - (ntsc - tsc);
1296 		} else
1297 			max_loops--;
1298 	} while (queued && max_loops > 0);
1299 	WARN_ON(max_loops <= 0);
1300 
1301 	/*
1302 	 * Now that we are all set up, enable the APIC
1303 	 */
1304 	value = apic_read(APIC_SPIV);
1305 	value &= ~APIC_VECTOR_MASK;
1306 	/*
1307 	 * Enable APIC
1308 	 */
1309 	value |= APIC_SPIV_APIC_ENABLED;
1310 
1311 #ifdef CONFIG_X86_32
1312 	/*
1313 	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1314 	 * certain networking cards. If high frequency interrupts are
1315 	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1316 	 * entry is masked/unmasked at a high rate as well then sooner or
1317 	 * later IOAPIC line gets 'stuck', no more interrupts are received
1318 	 * from the device. If focus CPU is disabled then the hang goes
1319 	 * away, oh well :-(
1320 	 *
1321 	 * [ This bug can be reproduced easily with a level-triggered
1322 	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1323 	 *   BX chipset. ]
1324 	 */
1325 	/*
1326 	 * Actually disabling the focus CPU check just makes the hang less
1327 	 * frequent as it makes the interrupt distributon model be more
1328 	 * like LRU than MRU (the short-term load is more even across CPUs).
1329 	 * See also the comment in end_level_ioapic_irq().  --macro
1330 	 */
1331 
1332 	/*
1333 	 * - enable focus processor (bit==0)
1334 	 * - 64bit mode always use processor focus
1335 	 *   so no need to set it
1336 	 */
1337 	value &= ~APIC_SPIV_FOCUS_DISABLED;
1338 #endif
1339 
1340 	/*
1341 	 * Set spurious IRQ vector
1342 	 */
1343 	value |= SPURIOUS_APIC_VECTOR;
1344 	apic_write(APIC_SPIV, value);
1345 
1346 	/*
1347 	 * Set up LVT0, LVT1:
1348 	 *
1349 	 * set up through-local-APIC on the BP's LINT0. This is not
1350 	 * strictly necessary in pure symmetric-IO mode, but sometimes
1351 	 * we delegate interrupts to the 8259A.
1352 	 */
1353 	/*
1354 	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1355 	 */
1356 	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1357 	if (!cpu && (pic_mode || !value)) {
1358 		value = APIC_DM_EXTINT;
1359 		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
1360 	} else {
1361 		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1362 		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
1363 	}
1364 	apic_write(APIC_LVT0, value);
1365 
1366 	/*
1367 	 * only the BP should see the LINT1 NMI signal, obviously.
1368 	 */
1369 	if (!cpu)
1370 		value = APIC_DM_NMI;
1371 	else
1372 		value = APIC_DM_NMI | APIC_LVT_MASKED;
1373 	if (!lapic_is_integrated())		/* 82489DX */
1374 		value |= APIC_LVT_LEVEL_TRIGGER;
1375 	apic_write(APIC_LVT1, value);
1376 
1377 #ifdef CONFIG_X86_MCE_INTEL
1378 	/* Recheck CMCI information after local APIC is up on CPU #0 */
1379 	if (!cpu)
1380 		cmci_recheck();
1381 #endif
1382 }
1383 
1384 void __cpuinit end_local_APIC_setup(void)
1385 {
1386 	lapic_setup_esr();
1387 
1388 #ifdef CONFIG_X86_32
1389 	{
1390 		unsigned int value;
1391 		/* Disable the local apic timer */
1392 		value = apic_read(APIC_LVTT);
1393 		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1394 		apic_write(APIC_LVTT, value);
1395 	}
1396 #endif
1397 
1398 	apic_pm_activate();
1399 }
1400 
1401 void __init bsp_end_local_APIC_setup(void)
1402 {
1403 	end_local_APIC_setup();
1404 
1405 	/*
1406 	 * Now that local APIC setup is completed for BP, configure the fault
1407 	 * handling for interrupt remapping.
1408 	 */
1409 	if (intr_remapping_enabled)
1410 		enable_drhd_fault_handling();
1411 
1412 }
1413 
1414 #ifdef CONFIG_X86_X2APIC
1415 void check_x2apic(void)
1416 {
1417 	if (x2apic_enabled()) {
1418 		pr_info("x2apic enabled by BIOS, switching to x2apic ops\n");
1419 		x2apic_preenabled = x2apic_mode = 1;
1420 	}
1421 }
1422 
1423 void enable_x2apic(void)
1424 {
1425 	int msr, msr2;
1426 
1427 	if (!x2apic_mode)
1428 		return;
1429 
1430 	rdmsr(MSR_IA32_APICBASE, msr, msr2);
1431 	if (!(msr & X2APIC_ENABLE)) {
1432 		printk_once(KERN_INFO "Enabling x2apic\n");
1433 		wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, msr2);
1434 	}
1435 }
1436 #endif /* CONFIG_X86_X2APIC */
1437 
1438 int __init enable_IR(void)
1439 {
1440 #ifdef CONFIG_IRQ_REMAP
1441 	if (!intr_remapping_supported()) {
1442 		pr_debug("intr-remapping not supported\n");
1443 		return -1;
1444 	}
1445 
1446 	if (!x2apic_preenabled && skip_ioapic_setup) {
1447 		pr_info("Skipped enabling intr-remap because of skipping "
1448 			"io-apic setup\n");
1449 		return -1;
1450 	}
1451 
1452 	return enable_intr_remapping();
1453 #endif
1454 	return -1;
1455 }
1456 
1457 void __init enable_IR_x2apic(void)
1458 {
1459 	unsigned long flags;
1460 	int ret, x2apic_enabled = 0;
1461 	int dmar_table_init_ret;
1462 
1463 	dmar_table_init_ret = dmar_table_init();
1464 	if (dmar_table_init_ret && !x2apic_supported())
1465 		return;
1466 
1467 	ret = save_ioapic_entries();
1468 	if (ret) {
1469 		pr_info("Saving IO-APIC state failed: %d\n", ret);
1470 		goto out;
1471 	}
1472 
1473 	local_irq_save(flags);
1474 	legacy_pic->mask_all();
1475 	mask_ioapic_entries();
1476 
1477 	if (dmar_table_init_ret)
1478 		ret = -1;
1479 	else
1480 		ret = enable_IR();
1481 
1482 	if (ret < 0) {
1483 		/* IR is required if there is APIC ID > 255 even when running
1484 		 * under KVM
1485 		 */
1486 		if (max_physical_apicid > 255 ||
1487 		    !hypervisor_x2apic_available())
1488 			goto nox2apic;
1489 		/*
1490 		 * without IR all CPUs can be addressed by IOAPIC/MSI
1491 		 * only in physical mode
1492 		 */
1493 		x2apic_force_phys();
1494 	}
1495 
1496 	if (ret == IRQ_REMAP_XAPIC_MODE)
1497 		goto nox2apic;
1498 
1499 	x2apic_enabled = 1;
1500 
1501 	if (x2apic_supported() && !x2apic_mode) {
1502 		x2apic_mode = 1;
1503 		enable_x2apic();
1504 		pr_info("Enabled x2apic\n");
1505 	}
1506 
1507 nox2apic:
1508 	if (ret < 0) /* IR enabling failed */
1509 		restore_ioapic_entries();
1510 	legacy_pic->restore_mask();
1511 	local_irq_restore(flags);
1512 
1513 out:
1514 	if (x2apic_enabled || !x2apic_supported())
1515 		return;
1516 
1517 	if (x2apic_preenabled)
1518 		panic("x2apic: enabled by BIOS but kernel init failed.");
1519 	else if (ret == IRQ_REMAP_XAPIC_MODE)
1520 		pr_info("x2apic not enabled, IRQ remapping is in xapic mode\n");
1521 	else if (ret < 0)
1522 		pr_info("x2apic not enabled, IRQ remapping init failed\n");
1523 }
1524 
1525 #ifdef CONFIG_X86_64
1526 /*
1527  * Detect and enable local APICs on non-SMP boards.
1528  * Original code written by Keir Fraser.
1529  * On AMD64 we trust the BIOS - if it says no APIC it is likely
1530  * not correctly set up (usually the APIC timer won't work etc.)
1531  */
1532 static int __init detect_init_APIC(void)
1533 {
1534 	if (!cpu_has_apic) {
1535 		pr_info("No local APIC present\n");
1536 		return -1;
1537 	}
1538 
1539 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1540 	return 0;
1541 }
1542 #else
1543 
1544 static int __init apic_verify(void)
1545 {
1546 	u32 features, h, l;
1547 
1548 	/*
1549 	 * The APIC feature bit should now be enabled
1550 	 * in `cpuid'
1551 	 */
1552 	features = cpuid_edx(1);
1553 	if (!(features & (1 << X86_FEATURE_APIC))) {
1554 		pr_warning("Could not enable APIC!\n");
1555 		return -1;
1556 	}
1557 	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1558 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1559 
1560 	/* The BIOS may have set up the APIC at some other address */
1561 	rdmsr(MSR_IA32_APICBASE, l, h);
1562 	if (l & MSR_IA32_APICBASE_ENABLE)
1563 		mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1564 
1565 	pr_info("Found and enabled local APIC!\n");
1566 	return 0;
1567 }
1568 
1569 int __init apic_force_enable(unsigned long addr)
1570 {
1571 	u32 h, l;
1572 
1573 	if (disable_apic)
1574 		return -1;
1575 
1576 	/*
1577 	 * Some BIOSes disable the local APIC in the APIC_BASE
1578 	 * MSR. This can only be done in software for Intel P6 or later
1579 	 * and AMD K7 (Model > 1) or later.
1580 	 */
1581 	rdmsr(MSR_IA32_APICBASE, l, h);
1582 	if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1583 		pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1584 		l &= ~MSR_IA32_APICBASE_BASE;
1585 		l |= MSR_IA32_APICBASE_ENABLE | addr;
1586 		wrmsr(MSR_IA32_APICBASE, l, h);
1587 		enabled_via_apicbase = 1;
1588 	}
1589 	return apic_verify();
1590 }
1591 
1592 /*
1593  * Detect and initialize APIC
1594  */
1595 static int __init detect_init_APIC(void)
1596 {
1597 	/* Disabled by kernel option? */
1598 	if (disable_apic)
1599 		return -1;
1600 
1601 	switch (boot_cpu_data.x86_vendor) {
1602 	case X86_VENDOR_AMD:
1603 		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1604 		    (boot_cpu_data.x86 >= 15))
1605 			break;
1606 		goto no_apic;
1607 	case X86_VENDOR_INTEL:
1608 		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1609 		    (boot_cpu_data.x86 == 5 && cpu_has_apic))
1610 			break;
1611 		goto no_apic;
1612 	default:
1613 		goto no_apic;
1614 	}
1615 
1616 	if (!cpu_has_apic) {
1617 		/*
1618 		 * Over-ride BIOS and try to enable the local APIC only if
1619 		 * "lapic" specified.
1620 		 */
1621 		if (!force_enable_local_apic) {
1622 			pr_info("Local APIC disabled by BIOS -- "
1623 				"you can enable it with \"lapic\"\n");
1624 			return -1;
1625 		}
1626 		if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
1627 			return -1;
1628 	} else {
1629 		if (apic_verify())
1630 			return -1;
1631 	}
1632 
1633 	apic_pm_activate();
1634 
1635 	return 0;
1636 
1637 no_apic:
1638 	pr_info("No local APIC present or hardware disabled\n");
1639 	return -1;
1640 }
1641 #endif
1642 
1643 /**
1644  * init_apic_mappings - initialize APIC mappings
1645  */
1646 void __init init_apic_mappings(void)
1647 {
1648 	unsigned int new_apicid;
1649 
1650 	if (x2apic_mode) {
1651 		boot_cpu_physical_apicid = read_apic_id();
1652 		return;
1653 	}
1654 
1655 	/* If no local APIC can be found return early */
1656 	if (!smp_found_config && detect_init_APIC()) {
1657 		/* lets NOP'ify apic operations */
1658 		pr_info("APIC: disable apic facility\n");
1659 		apic_disable();
1660 	} else {
1661 		apic_phys = mp_lapic_addr;
1662 
1663 		/*
1664 		 * acpi lapic path already maps that address in
1665 		 * acpi_register_lapic_address()
1666 		 */
1667 		if (!acpi_lapic && !smp_found_config)
1668 			register_lapic_address(apic_phys);
1669 	}
1670 
1671 	/*
1672 	 * Fetch the APIC ID of the BSP in case we have a
1673 	 * default configuration (or the MP table is broken).
1674 	 */
1675 	new_apicid = read_apic_id();
1676 	if (boot_cpu_physical_apicid != new_apicid) {
1677 		boot_cpu_physical_apicid = new_apicid;
1678 		/*
1679 		 * yeah -- we lie about apic_version
1680 		 * in case if apic was disabled via boot option
1681 		 * but it's not a problem for SMP compiled kernel
1682 		 * since smp_sanity_check is prepared for such a case
1683 		 * and disable smp mode
1684 		 */
1685 		apic_version[new_apicid] =
1686 			 GET_APIC_VERSION(apic_read(APIC_LVR));
1687 	}
1688 }
1689 
1690 void __init register_lapic_address(unsigned long address)
1691 {
1692 	mp_lapic_addr = address;
1693 
1694 	if (!x2apic_mode) {
1695 		set_fixmap_nocache(FIX_APIC_BASE, address);
1696 		apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
1697 			    APIC_BASE, mp_lapic_addr);
1698 	}
1699 	if (boot_cpu_physical_apicid == -1U) {
1700 		boot_cpu_physical_apicid  = read_apic_id();
1701 		apic_version[boot_cpu_physical_apicid] =
1702 			 GET_APIC_VERSION(apic_read(APIC_LVR));
1703 	}
1704 }
1705 
1706 /*
1707  * This initializes the IO-APIC and APIC hardware if this is
1708  * a UP kernel.
1709  */
1710 int apic_version[MAX_LOCAL_APIC];
1711 
1712 int __init APIC_init_uniprocessor(void)
1713 {
1714 	if (disable_apic) {
1715 		pr_info("Apic disabled\n");
1716 		return -1;
1717 	}
1718 #ifdef CONFIG_X86_64
1719 	if (!cpu_has_apic) {
1720 		disable_apic = 1;
1721 		pr_info("Apic disabled by BIOS\n");
1722 		return -1;
1723 	}
1724 #else
1725 	if (!smp_found_config && !cpu_has_apic)
1726 		return -1;
1727 
1728 	/*
1729 	 * Complain if the BIOS pretends there is one.
1730 	 */
1731 	if (!cpu_has_apic &&
1732 	    APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
1733 		pr_err("BIOS bug, local APIC 0x%x not detected!...\n",
1734 			boot_cpu_physical_apicid);
1735 		return -1;
1736 	}
1737 #endif
1738 
1739 	default_setup_apic_routing();
1740 
1741 	verify_local_APIC();
1742 	connect_bsp_APIC();
1743 
1744 #ifdef CONFIG_X86_64
1745 	apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
1746 #else
1747 	/*
1748 	 * Hack: In case of kdump, after a crash, kernel might be booting
1749 	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
1750 	 * might be zero if read from MP tables. Get it from LAPIC.
1751 	 */
1752 # ifdef CONFIG_CRASH_DUMP
1753 	boot_cpu_physical_apicid = read_apic_id();
1754 # endif
1755 #endif
1756 	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
1757 	setup_local_APIC();
1758 
1759 #ifdef CONFIG_X86_IO_APIC
1760 	/*
1761 	 * Now enable IO-APICs, actually call clear_IO_APIC
1762 	 * We need clear_IO_APIC before enabling error vector
1763 	 */
1764 	if (!skip_ioapic_setup && nr_ioapics)
1765 		enable_IO_APIC();
1766 #endif
1767 
1768 	bsp_end_local_APIC_setup();
1769 
1770 #ifdef CONFIG_X86_IO_APIC
1771 	if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1772 		setup_IO_APIC();
1773 	else {
1774 		nr_ioapics = 0;
1775 	}
1776 #endif
1777 
1778 	x86_init.timers.setup_percpu_clockev();
1779 	return 0;
1780 }
1781 
1782 /*
1783  * Local APIC interrupts
1784  */
1785 
1786 /*
1787  * This interrupt should _never_ happen with our APIC/SMP architecture
1788  */
1789 void smp_spurious_interrupt(struct pt_regs *regs)
1790 {
1791 	u32 v;
1792 
1793 	exit_idle();
1794 	irq_enter();
1795 	/*
1796 	 * Check if this really is a spurious interrupt and ACK it
1797 	 * if it is a vectored one.  Just in case...
1798 	 * Spurious interrupts should not be ACKed.
1799 	 */
1800 	v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1801 	if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1802 		ack_APIC_irq();
1803 
1804 	inc_irq_stat(irq_spurious_count);
1805 
1806 	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
1807 	pr_info("spurious APIC interrupt on CPU#%d, "
1808 		"should never happen.\n", smp_processor_id());
1809 	irq_exit();
1810 }
1811 
1812 /*
1813  * This interrupt should never happen with our APIC/SMP architecture
1814  */
1815 void smp_error_interrupt(struct pt_regs *regs)
1816 {
1817 	u32 v0, v1;
1818 	u32 i = 0;
1819 	static const char * const error_interrupt_reason[] = {
1820 		"Send CS error",		/* APIC Error Bit 0 */
1821 		"Receive CS error",		/* APIC Error Bit 1 */
1822 		"Send accept error",		/* APIC Error Bit 2 */
1823 		"Receive accept error",		/* APIC Error Bit 3 */
1824 		"Redirectable IPI",		/* APIC Error Bit 4 */
1825 		"Send illegal vector",		/* APIC Error Bit 5 */
1826 		"Received illegal vector",	/* APIC Error Bit 6 */
1827 		"Illegal register address",	/* APIC Error Bit 7 */
1828 	};
1829 
1830 	exit_idle();
1831 	irq_enter();
1832 	/* First tickle the hardware, only then report what went on. -- REW */
1833 	v0 = apic_read(APIC_ESR);
1834 	apic_write(APIC_ESR, 0);
1835 	v1 = apic_read(APIC_ESR);
1836 	ack_APIC_irq();
1837 	atomic_inc(&irq_err_count);
1838 
1839 	apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x(%02x)",
1840 		    smp_processor_id(), v0 , v1);
1841 
1842 	v1 = v1 & 0xff;
1843 	while (v1) {
1844 		if (v1 & 0x1)
1845 			apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
1846 		i++;
1847 		v1 >>= 1;
1848 	};
1849 
1850 	apic_printk(APIC_DEBUG, KERN_CONT "\n");
1851 
1852 	irq_exit();
1853 }
1854 
1855 /**
1856  * connect_bsp_APIC - attach the APIC to the interrupt system
1857  */
1858 void __init connect_bsp_APIC(void)
1859 {
1860 #ifdef CONFIG_X86_32
1861 	if (pic_mode) {
1862 		/*
1863 		 * Do not trust the local APIC being empty at bootup.
1864 		 */
1865 		clear_local_APIC();
1866 		/*
1867 		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
1868 		 * local APIC to INT and NMI lines.
1869 		 */
1870 		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
1871 				"enabling APIC mode.\n");
1872 		imcr_pic_to_apic();
1873 	}
1874 #endif
1875 	if (apic->enable_apic_mode)
1876 		apic->enable_apic_mode();
1877 }
1878 
1879 /**
1880  * disconnect_bsp_APIC - detach the APIC from the interrupt system
1881  * @virt_wire_setup:	indicates, whether virtual wire mode is selected
1882  *
1883  * Virtual wire mode is necessary to deliver legacy interrupts even when the
1884  * APIC is disabled.
1885  */
1886 void disconnect_bsp_APIC(int virt_wire_setup)
1887 {
1888 	unsigned int value;
1889 
1890 #ifdef CONFIG_X86_32
1891 	if (pic_mode) {
1892 		/*
1893 		 * Put the board back into PIC mode (has an effect only on
1894 		 * certain older boards).  Note that APIC interrupts, including
1895 		 * IPIs, won't work beyond this point!  The only exception are
1896 		 * INIT IPIs.
1897 		 */
1898 		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
1899 				"entering PIC mode.\n");
1900 		imcr_apic_to_pic();
1901 		return;
1902 	}
1903 #endif
1904 
1905 	/* Go back to Virtual Wire compatibility mode */
1906 
1907 	/* For the spurious interrupt use vector F, and enable it */
1908 	value = apic_read(APIC_SPIV);
1909 	value &= ~APIC_VECTOR_MASK;
1910 	value |= APIC_SPIV_APIC_ENABLED;
1911 	value |= 0xf;
1912 	apic_write(APIC_SPIV, value);
1913 
1914 	if (!virt_wire_setup) {
1915 		/*
1916 		 * For LVT0 make it edge triggered, active high,
1917 		 * external and enabled
1918 		 */
1919 		value = apic_read(APIC_LVT0);
1920 		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1921 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1922 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1923 		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1924 		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1925 		apic_write(APIC_LVT0, value);
1926 	} else {
1927 		/* Disable LVT0 */
1928 		apic_write(APIC_LVT0, APIC_LVT_MASKED);
1929 	}
1930 
1931 	/*
1932 	 * For LVT1 make it edge triggered, active high,
1933 	 * nmi and enabled
1934 	 */
1935 	value = apic_read(APIC_LVT1);
1936 	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1937 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1938 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1939 	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1940 	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1941 	apic_write(APIC_LVT1, value);
1942 }
1943 
1944 void __cpuinit generic_processor_info(int apicid, int version)
1945 {
1946 	int cpu, max = nr_cpu_ids;
1947 	bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
1948 				phys_cpu_present_map);
1949 
1950 	/*
1951 	 * If boot cpu has not been detected yet, then only allow upto
1952 	 * nr_cpu_ids - 1 processors and keep one slot free for boot cpu
1953 	 */
1954 	if (!boot_cpu_detected && num_processors >= nr_cpu_ids - 1 &&
1955 	    apicid != boot_cpu_physical_apicid) {
1956 		int thiscpu = max + disabled_cpus - 1;
1957 
1958 		pr_warning(
1959 			"ACPI: NR_CPUS/possible_cpus limit of %i almost"
1960 			" reached. Keeping one slot for boot cpu."
1961 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
1962 
1963 		disabled_cpus++;
1964 		return;
1965 	}
1966 
1967 	if (num_processors >= nr_cpu_ids) {
1968 		int thiscpu = max + disabled_cpus;
1969 
1970 		pr_warning(
1971 			"ACPI: NR_CPUS/possible_cpus limit of %i reached."
1972 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
1973 
1974 		disabled_cpus++;
1975 		return;
1976 	}
1977 
1978 	num_processors++;
1979 	if (apicid == boot_cpu_physical_apicid) {
1980 		/*
1981 		 * x86_bios_cpu_apicid is required to have processors listed
1982 		 * in same order as logical cpu numbers. Hence the first
1983 		 * entry is BSP, and so on.
1984 		 * boot_cpu_init() already hold bit 0 in cpu_present_mask
1985 		 * for BSP.
1986 		 */
1987 		cpu = 0;
1988 	} else
1989 		cpu = cpumask_next_zero(-1, cpu_present_mask);
1990 
1991 	/*
1992 	 * Validate version
1993 	 */
1994 	if (version == 0x0) {
1995 		pr_warning("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
1996 			   cpu, apicid);
1997 		version = 0x10;
1998 	}
1999 	apic_version[apicid] = version;
2000 
2001 	if (version != apic_version[boot_cpu_physical_apicid]) {
2002 		pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
2003 			apic_version[boot_cpu_physical_apicid], cpu, version);
2004 	}
2005 
2006 	physid_set(apicid, phys_cpu_present_map);
2007 	if (apicid > max_physical_apicid)
2008 		max_physical_apicid = apicid;
2009 
2010 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
2011 	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
2012 	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
2013 #endif
2014 #ifdef CONFIG_X86_32
2015 	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
2016 		apic->x86_32_early_logical_apicid(cpu);
2017 #endif
2018 	set_cpu_possible(cpu, true);
2019 	set_cpu_present(cpu, true);
2020 }
2021 
2022 int hard_smp_processor_id(void)
2023 {
2024 	return read_apic_id();
2025 }
2026 
2027 void default_init_apic_ldr(void)
2028 {
2029 	unsigned long val;
2030 
2031 	apic_write(APIC_DFR, APIC_DFR_VALUE);
2032 	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
2033 	val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
2034 	apic_write(APIC_LDR, val);
2035 }
2036 
2037 /*
2038  * Power management
2039  */
2040 #ifdef CONFIG_PM
2041 
2042 static struct {
2043 	/*
2044 	 * 'active' is true if the local APIC was enabled by us and
2045 	 * not the BIOS; this signifies that we are also responsible
2046 	 * for disabling it before entering apm/acpi suspend
2047 	 */
2048 	int active;
2049 	/* r/w apic fields */
2050 	unsigned int apic_id;
2051 	unsigned int apic_taskpri;
2052 	unsigned int apic_ldr;
2053 	unsigned int apic_dfr;
2054 	unsigned int apic_spiv;
2055 	unsigned int apic_lvtt;
2056 	unsigned int apic_lvtpc;
2057 	unsigned int apic_lvt0;
2058 	unsigned int apic_lvt1;
2059 	unsigned int apic_lvterr;
2060 	unsigned int apic_tmict;
2061 	unsigned int apic_tdcr;
2062 	unsigned int apic_thmr;
2063 } apic_pm_state;
2064 
2065 static int lapic_suspend(void)
2066 {
2067 	unsigned long flags;
2068 	int maxlvt;
2069 
2070 	if (!apic_pm_state.active)
2071 		return 0;
2072 
2073 	maxlvt = lapic_get_maxlvt();
2074 
2075 	apic_pm_state.apic_id = apic_read(APIC_ID);
2076 	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2077 	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2078 	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2079 	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2080 	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2081 	if (maxlvt >= 4)
2082 		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2083 	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2084 	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2085 	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2086 	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2087 	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2088 #ifdef CONFIG_X86_THERMAL_VECTOR
2089 	if (maxlvt >= 5)
2090 		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2091 #endif
2092 
2093 	local_irq_save(flags);
2094 	disable_local_APIC();
2095 
2096 	if (intr_remapping_enabled)
2097 		disable_intr_remapping();
2098 
2099 	local_irq_restore(flags);
2100 	return 0;
2101 }
2102 
2103 static void lapic_resume(void)
2104 {
2105 	unsigned int l, h;
2106 	unsigned long flags;
2107 	int maxlvt;
2108 
2109 	if (!apic_pm_state.active)
2110 		return;
2111 
2112 	local_irq_save(flags);
2113 	if (intr_remapping_enabled) {
2114 		/*
2115 		 * IO-APIC and PIC have their own resume routines.
2116 		 * We just mask them here to make sure the interrupt
2117 		 * subsystem is completely quiet while we enable x2apic
2118 		 * and interrupt-remapping.
2119 		 */
2120 		mask_ioapic_entries();
2121 		legacy_pic->mask_all();
2122 	}
2123 
2124 	if (x2apic_mode)
2125 		enable_x2apic();
2126 	else {
2127 		/*
2128 		 * Make sure the APICBASE points to the right address
2129 		 *
2130 		 * FIXME! This will be wrong if we ever support suspend on
2131 		 * SMP! We'll need to do this as part of the CPU restore!
2132 		 */
2133 		rdmsr(MSR_IA32_APICBASE, l, h);
2134 		l &= ~MSR_IA32_APICBASE_BASE;
2135 		l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2136 		wrmsr(MSR_IA32_APICBASE, l, h);
2137 	}
2138 
2139 	maxlvt = lapic_get_maxlvt();
2140 	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2141 	apic_write(APIC_ID, apic_pm_state.apic_id);
2142 	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2143 	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2144 	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2145 	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2146 	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2147 	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2148 #if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
2149 	if (maxlvt >= 5)
2150 		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2151 #endif
2152 	if (maxlvt >= 4)
2153 		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2154 	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2155 	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2156 	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2157 	apic_write(APIC_ESR, 0);
2158 	apic_read(APIC_ESR);
2159 	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2160 	apic_write(APIC_ESR, 0);
2161 	apic_read(APIC_ESR);
2162 
2163 	if (intr_remapping_enabled)
2164 		reenable_intr_remapping(x2apic_mode);
2165 
2166 	local_irq_restore(flags);
2167 }
2168 
2169 /*
2170  * This device has no shutdown method - fully functioning local APICs
2171  * are needed on every CPU up until machine_halt/restart/poweroff.
2172  */
2173 
2174 static struct syscore_ops lapic_syscore_ops = {
2175 	.resume		= lapic_resume,
2176 	.suspend	= lapic_suspend,
2177 };
2178 
2179 static void __cpuinit apic_pm_activate(void)
2180 {
2181 	apic_pm_state.active = 1;
2182 }
2183 
2184 static int __init init_lapic_sysfs(void)
2185 {
2186 	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2187 	if (cpu_has_apic)
2188 		register_syscore_ops(&lapic_syscore_ops);
2189 
2190 	return 0;
2191 }
2192 
2193 /* local apic needs to resume before other devices access its registers. */
2194 core_initcall(init_lapic_sysfs);
2195 
2196 #else	/* CONFIG_PM */
2197 
2198 static void apic_pm_activate(void) { }
2199 
2200 #endif	/* CONFIG_PM */
2201 
2202 #ifdef CONFIG_X86_64
2203 
2204 static int __cpuinit apic_cluster_num(void)
2205 {
2206 	int i, clusters, zeros;
2207 	unsigned id;
2208 	u16 *bios_cpu_apicid;
2209 	DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
2210 
2211 	bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
2212 	bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
2213 
2214 	for (i = 0; i < nr_cpu_ids; i++) {
2215 		/* are we being called early in kernel startup? */
2216 		if (bios_cpu_apicid) {
2217 			id = bios_cpu_apicid[i];
2218 		} else if (i < nr_cpu_ids) {
2219 			if (cpu_present(i))
2220 				id = per_cpu(x86_bios_cpu_apicid, i);
2221 			else
2222 				continue;
2223 		} else
2224 			break;
2225 
2226 		if (id != BAD_APICID)
2227 			__set_bit(APIC_CLUSTERID(id), clustermap);
2228 	}
2229 
2230 	/* Problem:  Partially populated chassis may not have CPUs in some of
2231 	 * the APIC clusters they have been allocated.  Only present CPUs have
2232 	 * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap.
2233 	 * Since clusters are allocated sequentially, count zeros only if
2234 	 * they are bounded by ones.
2235 	 */
2236 	clusters = 0;
2237 	zeros = 0;
2238 	for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
2239 		if (test_bit(i, clustermap)) {
2240 			clusters += 1 + zeros;
2241 			zeros = 0;
2242 		} else
2243 			++zeros;
2244 	}
2245 
2246 	return clusters;
2247 }
2248 
2249 static int __cpuinitdata multi_checked;
2250 static int __cpuinitdata multi;
2251 
2252 static int __cpuinit set_multi(const struct dmi_system_id *d)
2253 {
2254 	if (multi)
2255 		return 0;
2256 	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2257 	multi = 1;
2258 	return 0;
2259 }
2260 
2261 static const __cpuinitconst struct dmi_system_id multi_dmi_table[] = {
2262 	{
2263 		.callback = set_multi,
2264 		.ident = "IBM System Summit2",
2265 		.matches = {
2266 			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2267 			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2268 		},
2269 	},
2270 	{}
2271 };
2272 
2273 static void __cpuinit dmi_check_multi(void)
2274 {
2275 	if (multi_checked)
2276 		return;
2277 
2278 	dmi_check_system(multi_dmi_table);
2279 	multi_checked = 1;
2280 }
2281 
2282 /*
2283  * apic_is_clustered_box() -- Check if we can expect good TSC
2284  *
2285  * Thus far, the major user of this is IBM's Summit2 series:
2286  * Clustered boxes may have unsynced TSC problems if they are
2287  * multi-chassis.
2288  * Use DMI to check them
2289  */
2290 __cpuinit int apic_is_clustered_box(void)
2291 {
2292 	dmi_check_multi();
2293 	if (multi)
2294 		return 1;
2295 
2296 	if (!is_vsmp_box())
2297 		return 0;
2298 
2299 	/*
2300 	 * ScaleMP vSMPowered boxes have one cluster per board and TSCs are
2301 	 * not guaranteed to be synced between boards
2302 	 */
2303 	if (apic_cluster_num() > 1)
2304 		return 1;
2305 
2306 	return 0;
2307 }
2308 #endif
2309 
2310 /*
2311  * APIC command line parameters
2312  */
2313 static int __init setup_disableapic(char *arg)
2314 {
2315 	disable_apic = 1;
2316 	setup_clear_cpu_cap(X86_FEATURE_APIC);
2317 	return 0;
2318 }
2319 early_param("disableapic", setup_disableapic);
2320 
2321 /* same as disableapic, for compatibility */
2322 static int __init setup_nolapic(char *arg)
2323 {
2324 	return setup_disableapic(arg);
2325 }
2326 early_param("nolapic", setup_nolapic);
2327 
2328 static int __init parse_lapic_timer_c2_ok(char *arg)
2329 {
2330 	local_apic_timer_c2_ok = 1;
2331 	return 0;
2332 }
2333 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2334 
2335 static int __init parse_disable_apic_timer(char *arg)
2336 {
2337 	disable_apic_timer = 1;
2338 	return 0;
2339 }
2340 early_param("noapictimer", parse_disable_apic_timer);
2341 
2342 static int __init parse_nolapic_timer(char *arg)
2343 {
2344 	disable_apic_timer = 1;
2345 	return 0;
2346 }
2347 early_param("nolapic_timer", parse_nolapic_timer);
2348 
2349 static int __init apic_set_verbosity(char *arg)
2350 {
2351 	if (!arg)  {
2352 #ifdef CONFIG_X86_64
2353 		skip_ioapic_setup = 0;
2354 		return 0;
2355 #endif
2356 		return -EINVAL;
2357 	}
2358 
2359 	if (strcmp("debug", arg) == 0)
2360 		apic_verbosity = APIC_DEBUG;
2361 	else if (strcmp("verbose", arg) == 0)
2362 		apic_verbosity = APIC_VERBOSE;
2363 	else {
2364 		pr_warning("APIC Verbosity level %s not recognised"
2365 			" use apic=verbose or apic=debug\n", arg);
2366 		return -EINVAL;
2367 	}
2368 
2369 	return 0;
2370 }
2371 early_param("apic", apic_set_verbosity);
2372 
2373 static int __init lapic_insert_resource(void)
2374 {
2375 	if (!apic_phys)
2376 		return -1;
2377 
2378 	/* Put local APIC into the resource map. */
2379 	lapic_resource.start = apic_phys;
2380 	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2381 	insert_resource(&iomem_resource, &lapic_resource);
2382 
2383 	return 0;
2384 }
2385 
2386 /*
2387  * need call insert after e820_reserve_resources()
2388  * that is using request_resource
2389  */
2390 late_initcall(lapic_insert_resource);
2391