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/dmar.h>
31 #include <linux/init.h>
32 #include <linux/cpu.h>
33 #include <linux/dmi.h>
34 #include <linux/smp.h>
35 #include <linux/mm.h>
36 
37 #include <asm/perf_event.h>
38 #include <asm/x86_init.h>
39 #include <asm/pgalloc.h>
40 #include <asm/atomic.h>
41 #include <asm/mpspec.h>
42 #include <asm/i8253.h>
43 #include <asm/i8259.h>
44 #include <asm/proto.h>
45 #include <asm/apic.h>
46 #include <asm/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/smp.h>
52 #include <asm/mce.h>
53 #include <asm/tsc.h>
54 #include <asm/hypervisor.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 /*
84  * On x86_32, the mapping between cpu and logical apicid may vary
85  * depending on apic in use.  The following early percpu variable is
86  * used for the mapping.  This is where the behaviors of x86_64 and 32
87  * actually diverge.  Let's keep it ugly for now.
88  */
89 DEFINE_EARLY_PER_CPU(int, x86_cpu_to_logical_apicid, BAD_APICID);
90 
91 /*
92  * Knob to control our willingness to enable the local APIC.
93  *
94  * +1=force-enable
95  */
96 static int force_enable_local_apic __initdata;
97 /*
98  * APIC command line parameters
99  */
parse_lapic(char * arg)100 static int __init parse_lapic(char *arg)
101 {
102 	force_enable_local_apic = 1;
103 	return 0;
104 }
105 early_param("lapic", parse_lapic);
106 /* Local APIC was disabled by the BIOS and enabled by the kernel */
107 static int enabled_via_apicbase;
108 
109 /*
110  * Handle interrupt mode configuration register (IMCR).
111  * This register controls whether the interrupt signals
112  * that reach the BSP come from the master PIC or from the
113  * local APIC. Before entering Symmetric I/O Mode, either
114  * the BIOS or the operating system must switch out of
115  * PIC Mode by changing the IMCR.
116  */
imcr_pic_to_apic(void)117 static inline void imcr_pic_to_apic(void)
118 {
119 	/* select IMCR register */
120 	outb(0x70, 0x22);
121 	/* NMI and 8259 INTR go through APIC */
122 	outb(0x01, 0x23);
123 }
124 
imcr_apic_to_pic(void)125 static inline void imcr_apic_to_pic(void)
126 {
127 	/* select IMCR register */
128 	outb(0x70, 0x22);
129 	/* NMI and 8259 INTR go directly to BSP */
130 	outb(0x00, 0x23);
131 }
132 #endif
133 
134 #ifdef CONFIG_X86_64
135 static int apic_calibrate_pmtmr __initdata;
setup_apicpmtimer(char * s)136 static __init int setup_apicpmtimer(char *s)
137 {
138 	apic_calibrate_pmtmr = 1;
139 	notsc_setup(NULL);
140 	return 0;
141 }
142 __setup("apicpmtimer", setup_apicpmtimer);
143 #endif
144 
145 int x2apic_mode;
146 #ifdef CONFIG_X86_X2APIC
147 /* x2apic enabled before OS handover */
148 static int x2apic_preenabled;
setup_nox2apic(char * str)149 static __init int setup_nox2apic(char *str)
150 {
151 	if (x2apic_enabled()) {
152 		pr_warning("Bios already enabled x2apic, "
153 			   "can't enforce nox2apic");
154 		return 0;
155 	}
156 
157 	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
158 	return 0;
159 }
160 early_param("nox2apic", setup_nox2apic);
161 #endif
162 
163 unsigned long mp_lapic_addr;
164 int disable_apic;
165 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
166 static int disable_apic_timer __initdata;
167 /* Local APIC timer works in C2 */
168 int local_apic_timer_c2_ok;
169 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
170 
171 int first_system_vector = 0xfe;
172 
173 /*
174  * Debug level, exported for io_apic.c
175  */
176 unsigned int apic_verbosity;
177 
178 int pic_mode;
179 
180 /* Have we found an MP table */
181 int smp_found_config;
182 
183 static struct resource lapic_resource = {
184 	.name = "Local APIC",
185 	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
186 };
187 
188 static unsigned int calibration_result;
189 
190 static void apic_pm_activate(void);
191 
192 static unsigned long apic_phys;
193 
194 /*
195  * Get the LAPIC version
196  */
lapic_get_version(void)197 static inline int lapic_get_version(void)
198 {
199 	return GET_APIC_VERSION(apic_read(APIC_LVR));
200 }
201 
202 /*
203  * Check, if the APIC is integrated or a separate chip
204  */
lapic_is_integrated(void)205 static inline int lapic_is_integrated(void)
206 {
207 #ifdef CONFIG_X86_64
208 	return 1;
209 #else
210 	return APIC_INTEGRATED(lapic_get_version());
211 #endif
212 }
213 
214 /*
215  * Check, whether this is a modern or a first generation APIC
216  */
modern_apic(void)217 static int modern_apic(void)
218 {
219 	/* AMD systems use old APIC versions, so check the CPU */
220 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
221 	    boot_cpu_data.x86 >= 0xf)
222 		return 1;
223 	return lapic_get_version() >= 0x14;
224 }
225 
226 /*
227  * right after this call apic become NOOP driven
228  * so apic->write/read doesn't do anything
229  */
apic_disable(void)230 static void __init apic_disable(void)
231 {
232 	pr_info("APIC: switched to apic NOOP\n");
233 	apic = &apic_noop;
234 }
235 
native_apic_wait_icr_idle(void)236 void native_apic_wait_icr_idle(void)
237 {
238 	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
239 		cpu_relax();
240 }
241 
native_safe_apic_wait_icr_idle(void)242 u32 native_safe_apic_wait_icr_idle(void)
243 {
244 	u32 send_status;
245 	int timeout;
246 
247 	timeout = 0;
248 	do {
249 		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
250 		if (!send_status)
251 			break;
252 		udelay(100);
253 	} while (timeout++ < 1000);
254 
255 	return send_status;
256 }
257 
native_apic_icr_write(u32 low,u32 id)258 void native_apic_icr_write(u32 low, u32 id)
259 {
260 	apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
261 	apic_write(APIC_ICR, low);
262 }
263 
native_apic_icr_read(void)264 u64 native_apic_icr_read(void)
265 {
266 	u32 icr1, icr2;
267 
268 	icr2 = apic_read(APIC_ICR2);
269 	icr1 = apic_read(APIC_ICR);
270 
271 	return icr1 | ((u64)icr2 << 32);
272 }
273 
274 #ifdef CONFIG_X86_32
275 /**
276  * get_physical_broadcast - Get number of physical broadcast IDs
277  */
get_physical_broadcast(void)278 int get_physical_broadcast(void)
279 {
280 	return modern_apic() ? 0xff : 0xf;
281 }
282 #endif
283 
284 /**
285  * lapic_get_maxlvt - get the maximum number of local vector table entries
286  */
lapic_get_maxlvt(void)287 int lapic_get_maxlvt(void)
288 {
289 	unsigned int v;
290 
291 	v = apic_read(APIC_LVR);
292 	/*
293 	 * - we always have APIC integrated on 64bit mode
294 	 * - 82489DXs do not report # of LVT entries
295 	 */
296 	return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
297 }
298 
299 /*
300  * Local APIC timer
301  */
302 
303 /* Clock divisor */
304 #define APIC_DIVISOR 16
305 
306 /*
307  * This function sets up the local APIC timer, with a timeout of
308  * 'clocks' APIC bus clock. During calibration we actually call
309  * this function twice on the boot CPU, once with a bogus timeout
310  * value, second time for real. The other (noncalibrating) CPUs
311  * call this function only once, with the real, calibrated value.
312  *
313  * We do reads before writes even if unnecessary, to get around the
314  * P5 APIC double write bug.
315  */
__setup_APIC_LVTT(unsigned int clocks,int oneshot,int irqen)316 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
317 {
318 	unsigned int lvtt_value, tmp_value;
319 
320 	lvtt_value = LOCAL_TIMER_VECTOR;
321 	if (!oneshot)
322 		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
323 	if (!lapic_is_integrated())
324 		lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
325 
326 	if (!irqen)
327 		lvtt_value |= APIC_LVT_MASKED;
328 
329 	apic_write(APIC_LVTT, lvtt_value);
330 
331 	/*
332 	 * Divide PICLK by 16
333 	 */
334 	tmp_value = apic_read(APIC_TDCR);
335 	apic_write(APIC_TDCR,
336 		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
337 		APIC_TDR_DIV_16);
338 
339 	if (!oneshot)
340 		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
341 }
342 
343 /*
344  * Setup extended LVT, AMD specific
345  *
346  * Software should use the LVT offsets the BIOS provides.  The offsets
347  * are determined by the subsystems using it like those for MCE
348  * threshold or IBS.  On K8 only offset 0 (APIC500) and MCE interrupts
349  * are supported. Beginning with family 10h at least 4 offsets are
350  * available.
351  *
352  * Since the offsets must be consistent for all cores, we keep track
353  * of the LVT offsets in software and reserve the offset for the same
354  * vector also to be used on other cores. An offset is freed by
355  * setting the entry to APIC_EILVT_MASKED.
356  *
357  * If the BIOS is right, there should be no conflicts. Otherwise a
358  * "[Firmware Bug]: ..." error message is generated. However, if
359  * software does not properly determines the offsets, it is not
360  * necessarily a BIOS bug.
361  */
362 
363 static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
364 
eilvt_entry_is_changeable(unsigned int old,unsigned int new)365 static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
366 {
367 	return (old & APIC_EILVT_MASKED)
368 		|| (new == APIC_EILVT_MASKED)
369 		|| ((new & ~APIC_EILVT_MASKED) == old);
370 }
371 
reserve_eilvt_offset(int offset,unsigned int new)372 static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
373 {
374 	unsigned int rsvd;			/* 0: uninitialized */
375 
376 	if (offset >= APIC_EILVT_NR_MAX)
377 		return ~0;
378 
379 	rsvd = atomic_read(&eilvt_offsets[offset]) & ~APIC_EILVT_MASKED;
380 	do {
381 		if (rsvd &&
382 		    !eilvt_entry_is_changeable(rsvd, new))
383 			/* may not change if vectors are different */
384 			return rsvd;
385 		rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new);
386 	} while (rsvd != new);
387 
388 	return new;
389 }
390 
391 /*
392  * If mask=1, the LVT entry does not generate interrupts while mask=0
393  * enables the vector. See also the BKDGs.
394  */
395 
setup_APIC_eilvt(u8 offset,u8 vector,u8 msg_type,u8 mask)396 int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
397 {
398 	unsigned long reg = APIC_EILVTn(offset);
399 	unsigned int new, old, reserved;
400 
401 	new = (mask << 16) | (msg_type << 8) | vector;
402 	old = apic_read(reg);
403 	reserved = reserve_eilvt_offset(offset, new);
404 
405 	if (reserved != new) {
406 		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
407 		       "vector 0x%x, but the register is already in use for "
408 		       "vector 0x%x on another cpu\n",
409 		       smp_processor_id(), reg, offset, new, reserved);
410 		return -EINVAL;
411 	}
412 
413 	if (!eilvt_entry_is_changeable(old, new)) {
414 		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
415 		       "vector 0x%x, but the register is already in use for "
416 		       "vector 0x%x on this cpu\n",
417 		       smp_processor_id(), reg, offset, new, old);
418 		return -EBUSY;
419 	}
420 
421 	apic_write(reg, new);
422 
423 	return 0;
424 }
425 EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
426 
427 /*
428  * Program the next event, relative to now
429  */
lapic_next_event(unsigned long delta,struct clock_event_device * evt)430 static int lapic_next_event(unsigned long delta,
431 			    struct clock_event_device *evt)
432 {
433 	apic_write(APIC_TMICT, delta);
434 	return 0;
435 }
436 
437 /*
438  * Setup the lapic timer in periodic or oneshot mode
439  */
lapic_timer_setup(enum clock_event_mode mode,struct clock_event_device * evt)440 static void lapic_timer_setup(enum clock_event_mode mode,
441 			      struct clock_event_device *evt)
442 {
443 	unsigned long flags;
444 	unsigned int v;
445 
446 	/* Lapic used as dummy for broadcast ? */
447 	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
448 		return;
449 
450 	local_irq_save(flags);
451 
452 	switch (mode) {
453 	case CLOCK_EVT_MODE_PERIODIC:
454 	case CLOCK_EVT_MODE_ONESHOT:
455 		__setup_APIC_LVTT(calibration_result,
456 				  mode != CLOCK_EVT_MODE_PERIODIC, 1);
457 		break;
458 	case CLOCK_EVT_MODE_UNUSED:
459 	case CLOCK_EVT_MODE_SHUTDOWN:
460 		v = apic_read(APIC_LVTT);
461 		v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
462 		apic_write(APIC_LVTT, v);
463 		apic_write(APIC_TMICT, 0);
464 		break;
465 	case CLOCK_EVT_MODE_RESUME:
466 		/* Nothing to do here */
467 		break;
468 	}
469 
470 	local_irq_restore(flags);
471 }
472 
473 /*
474  * Local APIC timer broadcast function
475  */
lapic_timer_broadcast(const struct cpumask * mask)476 static void lapic_timer_broadcast(const struct cpumask *mask)
477 {
478 #ifdef CONFIG_SMP
479 	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
480 #endif
481 }
482 
483 
484 /*
485  * The local apic timer can be used for any function which is CPU local.
486  */
487 static struct clock_event_device lapic_clockevent = {
488 	.name		= "lapic",
489 	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
490 			| CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
491 	.shift		= 32,
492 	.set_mode	= lapic_timer_setup,
493 	.set_next_event	= lapic_next_event,
494 	.broadcast	= lapic_timer_broadcast,
495 	.rating		= 100,
496 	.irq		= -1,
497 };
498 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
499 
500 /*
501  * Setup the local APIC timer for this CPU. Copy the initialized values
502  * of the boot CPU and register the clock event in the framework.
503  */
setup_APIC_timer(void)504 static void __cpuinit setup_APIC_timer(void)
505 {
506 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
507 
508 	if (cpu_has(__this_cpu_ptr(&cpu_info), X86_FEATURE_ARAT)) {
509 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
510 		/* Make LAPIC timer preferrable over percpu HPET */
511 		lapic_clockevent.rating = 150;
512 	}
513 
514 	memcpy(levt, &lapic_clockevent, sizeof(*levt));
515 	levt->cpumask = cpumask_of(smp_processor_id());
516 
517 	clockevents_register_device(levt);
518 }
519 
520 /*
521  * In this functions we calibrate APIC bus clocks to the external timer.
522  *
523  * We want to do the calibration only once since we want to have local timer
524  * irqs syncron. CPUs connected by the same APIC bus have the very same bus
525  * frequency.
526  *
527  * This was previously done by reading the PIT/HPET and waiting for a wrap
528  * around to find out, that a tick has elapsed. I have a box, where the PIT
529  * readout is broken, so it never gets out of the wait loop again. This was
530  * also reported by others.
531  *
532  * Monitoring the jiffies value is inaccurate and the clockevents
533  * infrastructure allows us to do a simple substitution of the interrupt
534  * handler.
535  *
536  * The calibration routine also uses the pm_timer when possible, as the PIT
537  * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
538  * back to normal later in the boot process).
539  */
540 
541 #define LAPIC_CAL_LOOPS		(HZ/10)
542 
543 static __initdata int lapic_cal_loops = -1;
544 static __initdata long lapic_cal_t1, lapic_cal_t2;
545 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
546 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
547 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
548 
549 /*
550  * Temporary interrupt handler.
551  */
lapic_cal_handler(struct clock_event_device * dev)552 static void __init lapic_cal_handler(struct clock_event_device *dev)
553 {
554 	unsigned long long tsc = 0;
555 	long tapic = apic_read(APIC_TMCCT);
556 	unsigned long pm = acpi_pm_read_early();
557 
558 	if (cpu_has_tsc)
559 		rdtscll(tsc);
560 
561 	switch (lapic_cal_loops++) {
562 	case 0:
563 		lapic_cal_t1 = tapic;
564 		lapic_cal_tsc1 = tsc;
565 		lapic_cal_pm1 = pm;
566 		lapic_cal_j1 = jiffies;
567 		break;
568 
569 	case LAPIC_CAL_LOOPS:
570 		lapic_cal_t2 = tapic;
571 		lapic_cal_tsc2 = tsc;
572 		if (pm < lapic_cal_pm1)
573 			pm += ACPI_PM_OVRRUN;
574 		lapic_cal_pm2 = pm;
575 		lapic_cal_j2 = jiffies;
576 		break;
577 	}
578 }
579 
580 static int __init
calibrate_by_pmtimer(long deltapm,long * delta,long * deltatsc)581 calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
582 {
583 	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
584 	const long pm_thresh = pm_100ms / 100;
585 	unsigned long mult;
586 	u64 res;
587 
588 #ifndef CONFIG_X86_PM_TIMER
589 	return -1;
590 #endif
591 
592 	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
593 
594 	/* Check, if the PM timer is available */
595 	if (!deltapm)
596 		return -1;
597 
598 	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
599 
600 	if (deltapm > (pm_100ms - pm_thresh) &&
601 	    deltapm < (pm_100ms + pm_thresh)) {
602 		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
603 		return 0;
604 	}
605 
606 	res = (((u64)deltapm) *  mult) >> 22;
607 	do_div(res, 1000000);
608 	pr_warning("APIC calibration not consistent "
609 		   "with PM-Timer: %ldms instead of 100ms\n",(long)res);
610 
611 	/* Correct the lapic counter value */
612 	res = (((u64)(*delta)) * pm_100ms);
613 	do_div(res, deltapm);
614 	pr_info("APIC delta adjusted to PM-Timer: "
615 		"%lu (%ld)\n", (unsigned long)res, *delta);
616 	*delta = (long)res;
617 
618 	/* Correct the tsc counter value */
619 	if (cpu_has_tsc) {
620 		res = (((u64)(*deltatsc)) * pm_100ms);
621 		do_div(res, deltapm);
622 		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
623 					  "PM-Timer: %lu (%ld)\n",
624 					(unsigned long)res, *deltatsc);
625 		*deltatsc = (long)res;
626 	}
627 
628 	return 0;
629 }
630 
calibrate_APIC_clock(void)631 static int __init calibrate_APIC_clock(void)
632 {
633 	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
634 	void (*real_handler)(struct clock_event_device *dev);
635 	unsigned long deltaj;
636 	long delta, deltatsc;
637 	int pm_referenced = 0;
638 
639 	local_irq_disable();
640 
641 	/* Replace the global interrupt handler */
642 	real_handler = global_clock_event->event_handler;
643 	global_clock_event->event_handler = lapic_cal_handler;
644 
645 	/*
646 	 * Setup the APIC counter to maximum. There is no way the lapic
647 	 * can underflow in the 100ms detection time frame
648 	 */
649 	__setup_APIC_LVTT(0xffffffff, 0, 0);
650 
651 	/* Let the interrupts run */
652 	local_irq_enable();
653 
654 	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
655 		cpu_relax();
656 
657 	local_irq_disable();
658 
659 	/* Restore the real event handler */
660 	global_clock_event->event_handler = real_handler;
661 
662 	/* Build delta t1-t2 as apic timer counts down */
663 	delta = lapic_cal_t1 - lapic_cal_t2;
664 	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
665 
666 	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
667 
668 	/* we trust the PM based calibration if possible */
669 	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
670 					&delta, &deltatsc);
671 
672 	/* Calculate the scaled math multiplication factor */
673 	lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
674 				       lapic_clockevent.shift);
675 	lapic_clockevent.max_delta_ns =
676 		clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
677 	lapic_clockevent.min_delta_ns =
678 		clockevent_delta2ns(0xF, &lapic_clockevent);
679 
680 	calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
681 
682 	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
683 	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
684 	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
685 		    calibration_result);
686 
687 	if (cpu_has_tsc) {
688 		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
689 			    "%ld.%04ld MHz.\n",
690 			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
691 			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
692 	}
693 
694 	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
695 		    "%u.%04u MHz.\n",
696 		    calibration_result / (1000000 / HZ),
697 		    calibration_result % (1000000 / HZ));
698 
699 	/*
700 	 * Do a sanity check on the APIC calibration result
701 	 */
702 	if (calibration_result < (1000000 / HZ)) {
703 		local_irq_enable();
704 		pr_warning("APIC frequency too slow, disabling apic timer\n");
705 		return -1;
706 	}
707 
708 	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
709 
710 	/*
711 	 * PM timer calibration failed or not turned on
712 	 * so lets try APIC timer based calibration
713 	 */
714 	if (!pm_referenced) {
715 		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
716 
717 		/*
718 		 * Setup the apic timer manually
719 		 */
720 		levt->event_handler = lapic_cal_handler;
721 		lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
722 		lapic_cal_loops = -1;
723 
724 		/* Let the interrupts run */
725 		local_irq_enable();
726 
727 		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
728 			cpu_relax();
729 
730 		/* Stop the lapic timer */
731 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
732 
733 		/* Jiffies delta */
734 		deltaj = lapic_cal_j2 - lapic_cal_j1;
735 		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
736 
737 		/* Check, if the jiffies result is consistent */
738 		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
739 			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
740 		else
741 			levt->features |= CLOCK_EVT_FEAT_DUMMY;
742 	} else
743 		local_irq_enable();
744 
745 	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
746 		pr_warning("APIC timer disabled due to verification failure\n");
747 			return -1;
748 	}
749 
750 	return 0;
751 }
752 
753 /*
754  * Setup the boot APIC
755  *
756  * Calibrate and verify the result.
757  */
setup_boot_APIC_clock(void)758 void __init setup_boot_APIC_clock(void)
759 {
760 	/*
761 	 * The local apic timer can be disabled via the kernel
762 	 * commandline or from the CPU detection code. Register the lapic
763 	 * timer as a dummy clock event source on SMP systems, so the
764 	 * broadcast mechanism is used. On UP systems simply ignore it.
765 	 */
766 	if (disable_apic_timer) {
767 		pr_info("Disabling APIC timer\n");
768 		/* No broadcast on UP ! */
769 		if (num_possible_cpus() > 1) {
770 			lapic_clockevent.mult = 1;
771 			setup_APIC_timer();
772 		}
773 		return;
774 	}
775 
776 	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
777 		    "calibrating APIC timer ...\n");
778 
779 	if (calibrate_APIC_clock()) {
780 		/* No broadcast on UP ! */
781 		if (num_possible_cpus() > 1)
782 			setup_APIC_timer();
783 		return;
784 	}
785 
786 	/*
787 	 * If nmi_watchdog is set to IO_APIC, we need the
788 	 * PIT/HPET going.  Otherwise register lapic as a dummy
789 	 * device.
790 	 */
791 	lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
792 
793 	/* Setup the lapic or request the broadcast */
794 	setup_APIC_timer();
795 }
796 
setup_secondary_APIC_clock(void)797 void __cpuinit setup_secondary_APIC_clock(void)
798 {
799 	setup_APIC_timer();
800 }
801 
802 /*
803  * The guts of the apic timer interrupt
804  */
local_apic_timer_interrupt(void)805 static void local_apic_timer_interrupt(void)
806 {
807 	int cpu = smp_processor_id();
808 	struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
809 
810 	/*
811 	 * Normally we should not be here till LAPIC has been initialized but
812 	 * in some cases like kdump, its possible that there is a pending LAPIC
813 	 * timer interrupt from previous kernel's context and is delivered in
814 	 * new kernel the moment interrupts are enabled.
815 	 *
816 	 * Interrupts are enabled early and LAPIC is setup much later, hence
817 	 * its possible that when we get here evt->event_handler is NULL.
818 	 * Check for event_handler being NULL and discard the interrupt as
819 	 * spurious.
820 	 */
821 	if (!evt->event_handler) {
822 		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu);
823 		/* Switch it off */
824 		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
825 		return;
826 	}
827 
828 	/*
829 	 * the NMI deadlock-detector uses this.
830 	 */
831 	inc_irq_stat(apic_timer_irqs);
832 
833 	evt->event_handler(evt);
834 }
835 
836 /*
837  * Local APIC timer interrupt. This is the most natural way for doing
838  * local interrupts, but local timer interrupts can be emulated by
839  * broadcast interrupts too. [in case the hw doesn't support APIC timers]
840  *
841  * [ if a single-CPU system runs an SMP kernel then we call the local
842  *   interrupt as well. Thus we cannot inline the local irq ... ]
843  */
smp_apic_timer_interrupt(struct pt_regs * regs)844 void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
845 {
846 	struct pt_regs *old_regs = set_irq_regs(regs);
847 
848 	/*
849 	 * NOTE! We'd better ACK the irq immediately,
850 	 * because timer handling can be slow.
851 	 */
852 	ack_APIC_irq();
853 	/*
854 	 * update_process_times() expects us to have done irq_enter().
855 	 * Besides, if we don't timer interrupts ignore the global
856 	 * interrupt lock, which is the WrongThing (tm) to do.
857 	 */
858 	exit_idle();
859 	irq_enter();
860 	local_apic_timer_interrupt();
861 	irq_exit();
862 
863 	set_irq_regs(old_regs);
864 }
865 
setup_profiling_timer(unsigned int multiplier)866 int setup_profiling_timer(unsigned int multiplier)
867 {
868 	return -EINVAL;
869 }
870 
871 /*
872  * Local APIC start and shutdown
873  */
874 
875 /**
876  * clear_local_APIC - shutdown the local APIC
877  *
878  * This is called, when a CPU is disabled and before rebooting, so the state of
879  * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
880  * leftovers during boot.
881  */
clear_local_APIC(void)882 void clear_local_APIC(void)
883 {
884 	int maxlvt;
885 	u32 v;
886 
887 	/* APIC hasn't been mapped yet */
888 	if (!x2apic_mode && !apic_phys)
889 		return;
890 
891 	maxlvt = lapic_get_maxlvt();
892 	/*
893 	 * Masking an LVT entry can trigger a local APIC error
894 	 * if the vector is zero. Mask LVTERR first to prevent this.
895 	 */
896 	if (maxlvt >= 3) {
897 		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
898 		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
899 	}
900 	/*
901 	 * Careful: we have to set masks only first to deassert
902 	 * any level-triggered sources.
903 	 */
904 	v = apic_read(APIC_LVTT);
905 	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
906 	v = apic_read(APIC_LVT0);
907 	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
908 	v = apic_read(APIC_LVT1);
909 	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
910 	if (maxlvt >= 4) {
911 		v = apic_read(APIC_LVTPC);
912 		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
913 	}
914 
915 	/* lets not touch this if we didn't frob it */
916 #ifdef CONFIG_X86_THERMAL_VECTOR
917 	if (maxlvt >= 5) {
918 		v = apic_read(APIC_LVTTHMR);
919 		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
920 	}
921 #endif
922 #ifdef CONFIG_X86_MCE_INTEL
923 	if (maxlvt >= 6) {
924 		v = apic_read(APIC_LVTCMCI);
925 		if (!(v & APIC_LVT_MASKED))
926 			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
927 	}
928 #endif
929 
930 	/*
931 	 * Clean APIC state for other OSs:
932 	 */
933 	apic_write(APIC_LVTT, APIC_LVT_MASKED);
934 	apic_write(APIC_LVT0, APIC_LVT_MASKED);
935 	apic_write(APIC_LVT1, APIC_LVT_MASKED);
936 	if (maxlvt >= 3)
937 		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
938 	if (maxlvt >= 4)
939 		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
940 
941 	/* Integrated APIC (!82489DX) ? */
942 	if (lapic_is_integrated()) {
943 		if (maxlvt > 3)
944 			/* Clear ESR due to Pentium errata 3AP and 11AP */
945 			apic_write(APIC_ESR, 0);
946 		apic_read(APIC_ESR);
947 	}
948 }
949 
950 /**
951  * disable_local_APIC - clear and disable the local APIC
952  */
disable_local_APIC(void)953 void disable_local_APIC(void)
954 {
955 	unsigned int value;
956 
957 	/* APIC hasn't been mapped yet */
958 	if (!x2apic_mode && !apic_phys)
959 		return;
960 
961 	clear_local_APIC();
962 
963 	/*
964 	 * Disable APIC (implies clearing of registers
965 	 * for 82489DX!).
966 	 */
967 	value = apic_read(APIC_SPIV);
968 	value &= ~APIC_SPIV_APIC_ENABLED;
969 	apic_write(APIC_SPIV, value);
970 
971 #ifdef CONFIG_X86_32
972 	/*
973 	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
974 	 * restore the disabled state.
975 	 */
976 	if (enabled_via_apicbase) {
977 		unsigned int l, h;
978 
979 		rdmsr(MSR_IA32_APICBASE, l, h);
980 		l &= ~MSR_IA32_APICBASE_ENABLE;
981 		wrmsr(MSR_IA32_APICBASE, l, h);
982 	}
983 #endif
984 }
985 
986 /*
987  * If Linux enabled the LAPIC against the BIOS default disable it down before
988  * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
989  * not power-off.  Additionally clear all LVT entries before disable_local_APIC
990  * for the case where Linux didn't enable the LAPIC.
991  */
lapic_shutdown(void)992 void lapic_shutdown(void)
993 {
994 	unsigned long flags;
995 
996 	if (!cpu_has_apic && !apic_from_smp_config())
997 		return;
998 
999 	local_irq_save(flags);
1000 
1001 #ifdef CONFIG_X86_32
1002 	if (!enabled_via_apicbase)
1003 		clear_local_APIC();
1004 	else
1005 #endif
1006 		disable_local_APIC();
1007 
1008 
1009 	local_irq_restore(flags);
1010 }
1011 
1012 /*
1013  * This is to verify that we're looking at a real local APIC.
1014  * Check these against your board if the CPUs aren't getting
1015  * started for no apparent reason.
1016  */
verify_local_APIC(void)1017 int __init verify_local_APIC(void)
1018 {
1019 	unsigned int reg0, reg1;
1020 
1021 	/*
1022 	 * The version register is read-only in a real APIC.
1023 	 */
1024 	reg0 = apic_read(APIC_LVR);
1025 	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
1026 	apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
1027 	reg1 = apic_read(APIC_LVR);
1028 	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
1029 
1030 	/*
1031 	 * The two version reads above should print the same
1032 	 * numbers.  If the second one is different, then we
1033 	 * poke at a non-APIC.
1034 	 */
1035 	if (reg1 != reg0)
1036 		return 0;
1037 
1038 	/*
1039 	 * Check if the version looks reasonably.
1040 	 */
1041 	reg1 = GET_APIC_VERSION(reg0);
1042 	if (reg1 == 0x00 || reg1 == 0xff)
1043 		return 0;
1044 	reg1 = lapic_get_maxlvt();
1045 	if (reg1 < 0x02 || reg1 == 0xff)
1046 		return 0;
1047 
1048 	/*
1049 	 * The ID register is read/write in a real APIC.
1050 	 */
1051 	reg0 = apic_read(APIC_ID);
1052 	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
1053 	apic_write(APIC_ID, reg0 ^ apic->apic_id_mask);
1054 	reg1 = apic_read(APIC_ID);
1055 	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
1056 	apic_write(APIC_ID, reg0);
1057 	if (reg1 != (reg0 ^ apic->apic_id_mask))
1058 		return 0;
1059 
1060 	/*
1061 	 * The next two are just to see if we have sane values.
1062 	 * They're only really relevant if we're in Virtual Wire
1063 	 * compatibility mode, but most boxes are anymore.
1064 	 */
1065 	reg0 = apic_read(APIC_LVT0);
1066 	apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
1067 	reg1 = apic_read(APIC_LVT1);
1068 	apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
1069 
1070 	return 1;
1071 }
1072 
1073 /**
1074  * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1075  */
sync_Arb_IDs(void)1076 void __init sync_Arb_IDs(void)
1077 {
1078 	/*
1079 	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1080 	 * needed on AMD.
1081 	 */
1082 	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1083 		return;
1084 
1085 	/*
1086 	 * Wait for idle.
1087 	 */
1088 	apic_wait_icr_idle();
1089 
1090 	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1091 	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1092 			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1093 }
1094 
1095 /*
1096  * An initial setup of the virtual wire mode.
1097  */
init_bsp_APIC(void)1098 void __init init_bsp_APIC(void)
1099 {
1100 	unsigned int value;
1101 
1102 	/*
1103 	 * Don't do the setup now if we have a SMP BIOS as the
1104 	 * through-I/O-APIC virtual wire mode might be active.
1105 	 */
1106 	if (smp_found_config || !cpu_has_apic)
1107 		return;
1108 
1109 	/*
1110 	 * Do not trust the local APIC being empty at bootup.
1111 	 */
1112 	clear_local_APIC();
1113 
1114 	/*
1115 	 * Enable APIC.
1116 	 */
1117 	value = apic_read(APIC_SPIV);
1118 	value &= ~APIC_VECTOR_MASK;
1119 	value |= APIC_SPIV_APIC_ENABLED;
1120 
1121 #ifdef CONFIG_X86_32
1122 	/* This bit is reserved on P4/Xeon and should be cleared */
1123 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1124 	    (boot_cpu_data.x86 == 15))
1125 		value &= ~APIC_SPIV_FOCUS_DISABLED;
1126 	else
1127 #endif
1128 		value |= APIC_SPIV_FOCUS_DISABLED;
1129 	value |= SPURIOUS_APIC_VECTOR;
1130 	apic_write(APIC_SPIV, value);
1131 
1132 	/*
1133 	 * Set up the virtual wire mode.
1134 	 */
1135 	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1136 	value = APIC_DM_NMI;
1137 	if (!lapic_is_integrated())		/* 82489DX */
1138 		value |= APIC_LVT_LEVEL_TRIGGER;
1139 	apic_write(APIC_LVT1, value);
1140 }
1141 
lapic_setup_esr(void)1142 static void __cpuinit lapic_setup_esr(void)
1143 {
1144 	unsigned int oldvalue, value, maxlvt;
1145 
1146 	if (!lapic_is_integrated()) {
1147 		pr_info("No ESR for 82489DX.\n");
1148 		return;
1149 	}
1150 
1151 	if (apic->disable_esr) {
1152 		/*
1153 		 * Something untraceable is creating bad interrupts on
1154 		 * secondary quads ... for the moment, just leave the
1155 		 * ESR disabled - we can't do anything useful with the
1156 		 * errors anyway - mbligh
1157 		 */
1158 		pr_info("Leaving ESR disabled.\n");
1159 		return;
1160 	}
1161 
1162 	maxlvt = lapic_get_maxlvt();
1163 	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1164 		apic_write(APIC_ESR, 0);
1165 	oldvalue = apic_read(APIC_ESR);
1166 
1167 	/* enables sending errors */
1168 	value = ERROR_APIC_VECTOR;
1169 	apic_write(APIC_LVTERR, value);
1170 
1171 	/*
1172 	 * spec says clear errors after enabling vector.
1173 	 */
1174 	if (maxlvt > 3)
1175 		apic_write(APIC_ESR, 0);
1176 	value = apic_read(APIC_ESR);
1177 	if (value != oldvalue)
1178 		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1179 			"vector: 0x%08x  after: 0x%08x\n",
1180 			oldvalue, value);
1181 }
1182 
1183 /**
1184  * setup_local_APIC - setup the local APIC
1185  *
1186  * Used to setup local APIC while initializing BSP or bringin up APs.
1187  * Always called with preemption disabled.
1188  */
setup_local_APIC(void)1189 void __cpuinit setup_local_APIC(void)
1190 {
1191 	int cpu = smp_processor_id();
1192 	unsigned int value, queued;
1193 	int i, j, acked = 0;
1194 	unsigned long long tsc = 0, ntsc;
1195 	long long max_loops = cpu_khz;
1196 
1197 	if (cpu_has_tsc)
1198 		rdtscll(tsc);
1199 
1200 	if (disable_apic) {
1201 		disable_ioapic_support();
1202 		return;
1203 	}
1204 
1205 #ifdef CONFIG_X86_32
1206 	/* Pound the ESR really hard over the head with a big hammer - mbligh */
1207 	if (lapic_is_integrated() && apic->disable_esr) {
1208 		apic_write(APIC_ESR, 0);
1209 		apic_write(APIC_ESR, 0);
1210 		apic_write(APIC_ESR, 0);
1211 		apic_write(APIC_ESR, 0);
1212 	}
1213 #endif
1214 	perf_events_lapic_init();
1215 
1216 	/*
1217 	 * Double-check whether this APIC is really registered.
1218 	 * This is meaningless in clustered apic mode, so we skip it.
1219 	 */
1220 	BUG_ON(!apic->apic_id_registered());
1221 
1222 	/*
1223 	 * Intel recommends to set DFR, LDR and TPR before enabling
1224 	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
1225 	 * document number 292116).  So here it goes...
1226 	 */
1227 	apic->init_apic_ldr();
1228 
1229 #ifdef CONFIG_X86_32
1230 	/*
1231 	 * APIC LDR is initialized.  If logical_apicid mapping was
1232 	 * initialized during get_smp_config(), make sure it matches the
1233 	 * actual value.
1234 	 */
1235 	i = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
1236 	WARN_ON(i != BAD_APICID && i != logical_smp_processor_id());
1237 	/* always use the value from LDR */
1238 	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
1239 		logical_smp_processor_id();
1240 #endif
1241 
1242 	/*
1243 	 * Set Task Priority to 'accept all'. We never change this
1244 	 * later on.
1245 	 */
1246 	value = apic_read(APIC_TASKPRI);
1247 	value &= ~APIC_TPRI_MASK;
1248 	apic_write(APIC_TASKPRI, value);
1249 
1250 	/*
1251 	 * After a crash, we no longer service the interrupts and a pending
1252 	 * interrupt from previous kernel might still have ISR bit set.
1253 	 *
1254 	 * Most probably by now CPU has serviced that pending interrupt and
1255 	 * it might not have done the ack_APIC_irq() because it thought,
1256 	 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1257 	 * does not clear the ISR bit and cpu thinks it has already serivced
1258 	 * the interrupt. Hence a vector might get locked. It was noticed
1259 	 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1260 	 */
1261 	do {
1262 		queued = 0;
1263 		for (i = APIC_ISR_NR - 1; i >= 0; i--)
1264 			queued |= apic_read(APIC_IRR + i*0x10);
1265 
1266 		for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1267 			value = apic_read(APIC_ISR + i*0x10);
1268 			for (j = 31; j >= 0; j--) {
1269 				if (value & (1<<j)) {
1270 					ack_APIC_irq();
1271 					acked++;
1272 				}
1273 			}
1274 		}
1275 		if (acked > 256) {
1276 			printk(KERN_ERR "LAPIC pending interrupts after %d EOI\n",
1277 			       acked);
1278 			break;
1279 		}
1280 		if (cpu_has_tsc) {
1281 			rdtscll(ntsc);
1282 			max_loops = (cpu_khz << 10) - (ntsc - tsc);
1283 		} else
1284 			max_loops--;
1285 	} while (queued && max_loops > 0);
1286 	WARN_ON(max_loops <= 0);
1287 
1288 	/*
1289 	 * Now that we are all set up, enable the APIC
1290 	 */
1291 	value = apic_read(APIC_SPIV);
1292 	value &= ~APIC_VECTOR_MASK;
1293 	/*
1294 	 * Enable APIC
1295 	 */
1296 	value |= APIC_SPIV_APIC_ENABLED;
1297 
1298 #ifdef CONFIG_X86_32
1299 	/*
1300 	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1301 	 * certain networking cards. If high frequency interrupts are
1302 	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1303 	 * entry is masked/unmasked at a high rate as well then sooner or
1304 	 * later IOAPIC line gets 'stuck', no more interrupts are received
1305 	 * from the device. If focus CPU is disabled then the hang goes
1306 	 * away, oh well :-(
1307 	 *
1308 	 * [ This bug can be reproduced easily with a level-triggered
1309 	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1310 	 *   BX chipset. ]
1311 	 */
1312 	/*
1313 	 * Actually disabling the focus CPU check just makes the hang less
1314 	 * frequent as it makes the interrupt distributon model be more
1315 	 * like LRU than MRU (the short-term load is more even across CPUs).
1316 	 * See also the comment in end_level_ioapic_irq().  --macro
1317 	 */
1318 
1319 	/*
1320 	 * - enable focus processor (bit==0)
1321 	 * - 64bit mode always use processor focus
1322 	 *   so no need to set it
1323 	 */
1324 	value &= ~APIC_SPIV_FOCUS_DISABLED;
1325 #endif
1326 
1327 	/*
1328 	 * Set spurious IRQ vector
1329 	 */
1330 	value |= SPURIOUS_APIC_VECTOR;
1331 	apic_write(APIC_SPIV, value);
1332 
1333 	/*
1334 	 * Set up LVT0, LVT1:
1335 	 *
1336 	 * set up through-local-APIC on the BP's LINT0. This is not
1337 	 * strictly necessary in pure symmetric-IO mode, but sometimes
1338 	 * we delegate interrupts to the 8259A.
1339 	 */
1340 	/*
1341 	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1342 	 */
1343 	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1344 	if (!cpu && (pic_mode || !value)) {
1345 		value = APIC_DM_EXTINT;
1346 		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
1347 	} else {
1348 		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1349 		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
1350 	}
1351 	apic_write(APIC_LVT0, value);
1352 
1353 	/*
1354 	 * only the BP should see the LINT1 NMI signal, obviously.
1355 	 */
1356 	if (!cpu)
1357 		value = APIC_DM_NMI;
1358 	else
1359 		value = APIC_DM_NMI | APIC_LVT_MASKED;
1360 	if (!lapic_is_integrated())		/* 82489DX */
1361 		value |= APIC_LVT_LEVEL_TRIGGER;
1362 	apic_write(APIC_LVT1, value);
1363 
1364 #ifdef CONFIG_X86_MCE_INTEL
1365 	/* Recheck CMCI information after local APIC is up on CPU #0 */
1366 	if (!cpu)
1367 		cmci_recheck();
1368 #endif
1369 }
1370 
end_local_APIC_setup(void)1371 void __cpuinit end_local_APIC_setup(void)
1372 {
1373 	lapic_setup_esr();
1374 
1375 #ifdef CONFIG_X86_32
1376 	{
1377 		unsigned int value;
1378 		/* Disable the local apic timer */
1379 		value = apic_read(APIC_LVTT);
1380 		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1381 		apic_write(APIC_LVTT, value);
1382 	}
1383 #endif
1384 
1385 	apic_pm_activate();
1386 }
1387 
bsp_end_local_APIC_setup(void)1388 void __init bsp_end_local_APIC_setup(void)
1389 {
1390 	end_local_APIC_setup();
1391 
1392 	/*
1393 	 * Now that local APIC setup is completed for BP, configure the fault
1394 	 * handling for interrupt remapping.
1395 	 */
1396 	if (intr_remapping_enabled)
1397 		enable_drhd_fault_handling();
1398 
1399 }
1400 
1401 #ifdef CONFIG_X86_X2APIC
check_x2apic(void)1402 void check_x2apic(void)
1403 {
1404 	if (x2apic_enabled()) {
1405 		pr_info("x2apic enabled by BIOS, switching to x2apic ops\n");
1406 		x2apic_preenabled = x2apic_mode = 1;
1407 	}
1408 }
1409 
enable_x2apic(void)1410 void enable_x2apic(void)
1411 {
1412 	int msr, msr2;
1413 
1414 	if (!x2apic_mode)
1415 		return;
1416 
1417 	rdmsr(MSR_IA32_APICBASE, msr, msr2);
1418 	if (!(msr & X2APIC_ENABLE)) {
1419 		printk_once(KERN_INFO "Enabling x2apic\n");
1420 		wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, 0);
1421 	}
1422 }
1423 #endif /* CONFIG_X86_X2APIC */
1424 
enable_IR(void)1425 int __init enable_IR(void)
1426 {
1427 #ifdef CONFIG_INTR_REMAP
1428 	if (!intr_remapping_supported()) {
1429 		pr_debug("intr-remapping not supported\n");
1430 		return 0;
1431 	}
1432 
1433 	if (!x2apic_preenabled && skip_ioapic_setup) {
1434 		pr_info("Skipped enabling intr-remap because of skipping "
1435 			"io-apic setup\n");
1436 		return 0;
1437 	}
1438 
1439 	if (enable_intr_remapping(x2apic_supported()))
1440 		return 0;
1441 
1442 	pr_info("Enabled Interrupt-remapping\n");
1443 
1444 	return 1;
1445 
1446 #endif
1447 	return 0;
1448 }
1449 
enable_IR_x2apic(void)1450 void __init enable_IR_x2apic(void)
1451 {
1452 	unsigned long flags;
1453 	struct IO_APIC_route_entry **ioapic_entries;
1454 	int ret, x2apic_enabled = 0;
1455 	int dmar_table_init_ret;
1456 
1457 	dmar_table_init_ret = dmar_table_init();
1458 	if (dmar_table_init_ret && !x2apic_supported())
1459 		return;
1460 
1461 	ioapic_entries = alloc_ioapic_entries();
1462 	if (!ioapic_entries) {
1463 		pr_err("Allocate ioapic_entries failed\n");
1464 		goto out;
1465 	}
1466 
1467 	ret = save_IO_APIC_setup(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_IO_APIC_setup(ioapic_entries);
1476 
1477 	if (dmar_table_init_ret)
1478 		ret = 0;
1479 	else
1480 		ret = enable_IR();
1481 
1482 	if (!ret) {
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 	x2apic_enabled = 1;
1497 
1498 	if (x2apic_supported() && !x2apic_mode) {
1499 		x2apic_mode = 1;
1500 		enable_x2apic();
1501 		pr_info("Enabled x2apic\n");
1502 	}
1503 
1504 nox2apic:
1505 	if (!ret) /* IR enabling failed */
1506 		restore_IO_APIC_setup(ioapic_entries);
1507 	legacy_pic->restore_mask();
1508 	local_irq_restore(flags);
1509 
1510 out:
1511 	if (ioapic_entries)
1512 		free_ioapic_entries(ioapic_entries);
1513 
1514 	if (x2apic_enabled)
1515 		return;
1516 
1517 	if (x2apic_preenabled)
1518 		panic("x2apic: enabled by BIOS but kernel init failed.");
1519 	else if (cpu_has_x2apic)
1520 		pr_info("Not enabling x2apic, Intr-remapping init failed.\n");
1521 }
1522 
1523 #ifdef CONFIG_X86_64
1524 /*
1525  * Detect and enable local APICs on non-SMP boards.
1526  * Original code written by Keir Fraser.
1527  * On AMD64 we trust the BIOS - if it says no APIC it is likely
1528  * not correctly set up (usually the APIC timer won't work etc.)
1529  */
detect_init_APIC(void)1530 static int __init detect_init_APIC(void)
1531 {
1532 	if (!cpu_has_apic) {
1533 		pr_info("No local APIC present\n");
1534 		return -1;
1535 	}
1536 
1537 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1538 	return 0;
1539 }
1540 #else
1541 
apic_verify(void)1542 static int __init apic_verify(void)
1543 {
1544 	u32 features, h, l;
1545 
1546 	/*
1547 	 * The APIC feature bit should now be enabled
1548 	 * in `cpuid'
1549 	 */
1550 	features = cpuid_edx(1);
1551 	if (!(features & (1 << X86_FEATURE_APIC))) {
1552 		pr_warning("Could not enable APIC!\n");
1553 		return -1;
1554 	}
1555 	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1556 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1557 
1558 	/* The BIOS may have set up the APIC at some other address */
1559 	rdmsr(MSR_IA32_APICBASE, l, h);
1560 	if (l & MSR_IA32_APICBASE_ENABLE)
1561 		mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1562 
1563 	pr_info("Found and enabled local APIC!\n");
1564 	return 0;
1565 }
1566 
apic_force_enable(unsigned long addr)1567 int __init apic_force_enable(unsigned long addr)
1568 {
1569 	u32 h, l;
1570 
1571 	if (disable_apic)
1572 		return -1;
1573 
1574 	/*
1575 	 * Some BIOSes disable the local APIC in the APIC_BASE
1576 	 * MSR. This can only be done in software for Intel P6 or later
1577 	 * and AMD K7 (Model > 1) or later.
1578 	 */
1579 	rdmsr(MSR_IA32_APICBASE, l, h);
1580 	if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1581 		pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1582 		l &= ~MSR_IA32_APICBASE_BASE;
1583 		l |= MSR_IA32_APICBASE_ENABLE | addr;
1584 		wrmsr(MSR_IA32_APICBASE, l, h);
1585 		enabled_via_apicbase = 1;
1586 	}
1587 	return apic_verify();
1588 }
1589 
1590 /*
1591  * Detect and initialize APIC
1592  */
detect_init_APIC(void)1593 static int __init detect_init_APIC(void)
1594 {
1595 	/* Disabled by kernel option? */
1596 	if (disable_apic)
1597 		return -1;
1598 
1599 	switch (boot_cpu_data.x86_vendor) {
1600 	case X86_VENDOR_AMD:
1601 		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1602 		    (boot_cpu_data.x86 >= 15))
1603 			break;
1604 		goto no_apic;
1605 	case X86_VENDOR_INTEL:
1606 		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1607 		    (boot_cpu_data.x86 == 5 && cpu_has_apic))
1608 			break;
1609 		goto no_apic;
1610 	default:
1611 		goto no_apic;
1612 	}
1613 
1614 	if (!cpu_has_apic) {
1615 		/*
1616 		 * Over-ride BIOS and try to enable the local APIC only if
1617 		 * "lapic" specified.
1618 		 */
1619 		if (!force_enable_local_apic) {
1620 			pr_info("Local APIC disabled by BIOS -- "
1621 				"you can enable it with \"lapic\"\n");
1622 			return -1;
1623 		}
1624 		if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
1625 			return -1;
1626 	} else {
1627 		if (apic_verify())
1628 			return -1;
1629 	}
1630 
1631 	apic_pm_activate();
1632 
1633 	return 0;
1634 
1635 no_apic:
1636 	pr_info("No local APIC present or hardware disabled\n");
1637 	return -1;
1638 }
1639 #endif
1640 
1641 /**
1642  * init_apic_mappings - initialize APIC mappings
1643  */
init_apic_mappings(void)1644 void __init init_apic_mappings(void)
1645 {
1646 	unsigned int new_apicid;
1647 
1648 	if (x2apic_mode) {
1649 		boot_cpu_physical_apicid = read_apic_id();
1650 		return;
1651 	}
1652 
1653 	/* If no local APIC can be found return early */
1654 	if (!smp_found_config && detect_init_APIC()) {
1655 		/* lets NOP'ify apic operations */
1656 		pr_info("APIC: disable apic facility\n");
1657 		apic_disable();
1658 	} else {
1659 		apic_phys = mp_lapic_addr;
1660 
1661 		/*
1662 		 * acpi lapic path already maps that address in
1663 		 * acpi_register_lapic_address()
1664 		 */
1665 		if (!acpi_lapic && !smp_found_config)
1666 			register_lapic_address(apic_phys);
1667 	}
1668 
1669 	/*
1670 	 * Fetch the APIC ID of the BSP in case we have a
1671 	 * default configuration (or the MP table is broken).
1672 	 */
1673 	new_apicid = read_apic_id();
1674 	if (boot_cpu_physical_apicid != new_apicid) {
1675 		boot_cpu_physical_apicid = new_apicid;
1676 		/*
1677 		 * yeah -- we lie about apic_version
1678 		 * in case if apic was disabled via boot option
1679 		 * but it's not a problem for SMP compiled kernel
1680 		 * since smp_sanity_check is prepared for such a case
1681 		 * and disable smp mode
1682 		 */
1683 		apic_version[new_apicid] =
1684 			 GET_APIC_VERSION(apic_read(APIC_LVR));
1685 	}
1686 }
1687 
register_lapic_address(unsigned long address)1688 void __init register_lapic_address(unsigned long address)
1689 {
1690 	mp_lapic_addr = address;
1691 
1692 	if (!x2apic_mode) {
1693 		set_fixmap_nocache(FIX_APIC_BASE, address);
1694 		apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
1695 			    APIC_BASE, mp_lapic_addr);
1696 	}
1697 	if (boot_cpu_physical_apicid == -1U) {
1698 		boot_cpu_physical_apicid  = read_apic_id();
1699 		apic_version[boot_cpu_physical_apicid] =
1700 			 GET_APIC_VERSION(apic_read(APIC_LVR));
1701 	}
1702 }
1703 
1704 /*
1705  * This initializes the IO-APIC and APIC hardware if this is
1706  * a UP kernel.
1707  */
1708 int apic_version[MAX_LOCAL_APIC];
1709 
APIC_init_uniprocessor(void)1710 int __init APIC_init_uniprocessor(void)
1711 {
1712 	if (disable_apic) {
1713 		pr_info("Apic disabled\n");
1714 		return -1;
1715 	}
1716 #ifdef CONFIG_X86_64
1717 	if (!cpu_has_apic) {
1718 		disable_apic = 1;
1719 		pr_info("Apic disabled by BIOS\n");
1720 		return -1;
1721 	}
1722 #else
1723 	if (!smp_found_config && !cpu_has_apic)
1724 		return -1;
1725 
1726 	/*
1727 	 * Complain if the BIOS pretends there is one.
1728 	 */
1729 	if (!cpu_has_apic &&
1730 	    APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
1731 		pr_err("BIOS bug, local APIC 0x%x not detected!...\n",
1732 			boot_cpu_physical_apicid);
1733 		return -1;
1734 	}
1735 #endif
1736 
1737 	default_setup_apic_routing();
1738 
1739 	verify_local_APIC();
1740 	connect_bsp_APIC();
1741 
1742 #ifdef CONFIG_X86_64
1743 	apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
1744 #else
1745 	/*
1746 	 * Hack: In case of kdump, after a crash, kernel might be booting
1747 	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
1748 	 * might be zero if read from MP tables. Get it from LAPIC.
1749 	 */
1750 # ifdef CONFIG_CRASH_DUMP
1751 	boot_cpu_physical_apicid = read_apic_id();
1752 # endif
1753 #endif
1754 	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
1755 	setup_local_APIC();
1756 
1757 #ifdef CONFIG_X86_IO_APIC
1758 	/*
1759 	 * Now enable IO-APICs, actually call clear_IO_APIC
1760 	 * We need clear_IO_APIC before enabling error vector
1761 	 */
1762 	if (!skip_ioapic_setup && nr_ioapics)
1763 		enable_IO_APIC();
1764 #endif
1765 
1766 	bsp_end_local_APIC_setup();
1767 
1768 #ifdef CONFIG_X86_IO_APIC
1769 	if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1770 		setup_IO_APIC();
1771 	else {
1772 		nr_ioapics = 0;
1773 	}
1774 #endif
1775 
1776 	x86_init.timers.setup_percpu_clockev();
1777 	return 0;
1778 }
1779 
1780 /*
1781  * Local APIC interrupts
1782  */
1783 
1784 /*
1785  * This interrupt should _never_ happen with our APIC/SMP architecture
1786  */
smp_spurious_interrupt(struct pt_regs * regs)1787 void smp_spurious_interrupt(struct pt_regs *regs)
1788 {
1789 	u32 v;
1790 
1791 	exit_idle();
1792 	irq_enter();
1793 	/*
1794 	 * Check if this really is a spurious interrupt and ACK it
1795 	 * if it is a vectored one.  Just in case...
1796 	 * Spurious interrupts should not be ACKed.
1797 	 */
1798 	v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1799 	if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1800 		ack_APIC_irq();
1801 
1802 	inc_irq_stat(irq_spurious_count);
1803 
1804 	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
1805 	pr_info("spurious APIC interrupt on CPU#%d, "
1806 		"should never happen.\n", smp_processor_id());
1807 	irq_exit();
1808 }
1809 
1810 /*
1811  * This interrupt should never happen with our APIC/SMP architecture
1812  */
smp_error_interrupt(struct pt_regs * regs)1813 void smp_error_interrupt(struct pt_regs *regs)
1814 {
1815 	u32 v, v1;
1816 
1817 	exit_idle();
1818 	irq_enter();
1819 	/* First tickle the hardware, only then report what went on. -- REW */
1820 	v = apic_read(APIC_ESR);
1821 	apic_write(APIC_ESR, 0);
1822 	v1 = apic_read(APIC_ESR);
1823 	ack_APIC_irq();
1824 	atomic_inc(&irq_err_count);
1825 
1826 	/*
1827 	 * Here is what the APIC error bits mean:
1828 	 * 0: Send CS error
1829 	 * 1: Receive CS error
1830 	 * 2: Send accept error
1831 	 * 3: Receive accept error
1832 	 * 4: Reserved
1833 	 * 5: Send illegal vector
1834 	 * 6: Received illegal vector
1835 	 * 7: Illegal register address
1836 	 */
1837 	pr_debug("APIC error on CPU%d: %02x(%02x)\n",
1838 		smp_processor_id(), v , v1);
1839 	irq_exit();
1840 }
1841 
1842 /**
1843  * connect_bsp_APIC - attach the APIC to the interrupt system
1844  */
connect_bsp_APIC(void)1845 void __init connect_bsp_APIC(void)
1846 {
1847 #ifdef CONFIG_X86_32
1848 	if (pic_mode) {
1849 		/*
1850 		 * Do not trust the local APIC being empty at bootup.
1851 		 */
1852 		clear_local_APIC();
1853 		/*
1854 		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
1855 		 * local APIC to INT and NMI lines.
1856 		 */
1857 		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
1858 				"enabling APIC mode.\n");
1859 		imcr_pic_to_apic();
1860 	}
1861 #endif
1862 	if (apic->enable_apic_mode)
1863 		apic->enable_apic_mode();
1864 }
1865 
1866 /**
1867  * disconnect_bsp_APIC - detach the APIC from the interrupt system
1868  * @virt_wire_setup:	indicates, whether virtual wire mode is selected
1869  *
1870  * Virtual wire mode is necessary to deliver legacy interrupts even when the
1871  * APIC is disabled.
1872  */
disconnect_bsp_APIC(int virt_wire_setup)1873 void disconnect_bsp_APIC(int virt_wire_setup)
1874 {
1875 	unsigned int value;
1876 
1877 #ifdef CONFIG_X86_32
1878 	if (pic_mode) {
1879 		/*
1880 		 * Put the board back into PIC mode (has an effect only on
1881 		 * certain older boards).  Note that APIC interrupts, including
1882 		 * IPIs, won't work beyond this point!  The only exception are
1883 		 * INIT IPIs.
1884 		 */
1885 		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
1886 				"entering PIC mode.\n");
1887 		imcr_apic_to_pic();
1888 		return;
1889 	}
1890 #endif
1891 
1892 	/* Go back to Virtual Wire compatibility mode */
1893 
1894 	/* For the spurious interrupt use vector F, and enable it */
1895 	value = apic_read(APIC_SPIV);
1896 	value &= ~APIC_VECTOR_MASK;
1897 	value |= APIC_SPIV_APIC_ENABLED;
1898 	value |= 0xf;
1899 	apic_write(APIC_SPIV, value);
1900 
1901 	if (!virt_wire_setup) {
1902 		/*
1903 		 * For LVT0 make it edge triggered, active high,
1904 		 * external and enabled
1905 		 */
1906 		value = apic_read(APIC_LVT0);
1907 		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1908 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1909 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1910 		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1911 		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1912 		apic_write(APIC_LVT0, value);
1913 	} else {
1914 		/* Disable LVT0 */
1915 		apic_write(APIC_LVT0, APIC_LVT_MASKED);
1916 	}
1917 
1918 	/*
1919 	 * For LVT1 make it edge triggered, active high,
1920 	 * nmi and enabled
1921 	 */
1922 	value = apic_read(APIC_LVT1);
1923 	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1924 			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1925 			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1926 	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1927 	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1928 	apic_write(APIC_LVT1, value);
1929 }
1930 
generic_processor_info(int apicid,int version)1931 void __cpuinit generic_processor_info(int apicid, int version)
1932 {
1933 	int cpu;
1934 
1935 	if (num_processors >= nr_cpu_ids) {
1936 		int max = nr_cpu_ids;
1937 		int thiscpu = max + disabled_cpus;
1938 
1939 		pr_warning(
1940 			"ACPI: NR_CPUS/possible_cpus limit of %i reached."
1941 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
1942 
1943 		disabled_cpus++;
1944 		return;
1945 	}
1946 
1947 	num_processors++;
1948 	if (apicid == boot_cpu_physical_apicid) {
1949 		/*
1950 		 * x86_bios_cpu_apicid is required to have processors listed
1951 		 * in same order as logical cpu numbers. Hence the first
1952 		 * entry is BSP, and so on.
1953 		 * boot_cpu_init() already hold bit 0 in cpu_present_mask
1954 		 * for BSP.
1955 		 */
1956 		cpu = 0;
1957 	} else
1958 		cpu = cpumask_next_zero(-1, cpu_present_mask);
1959 
1960 	/*
1961 	 * Validate version
1962 	 */
1963 	if (version == 0x0) {
1964 		pr_warning("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
1965 			   cpu, apicid);
1966 		version = 0x10;
1967 	}
1968 	apic_version[apicid] = version;
1969 
1970 	if (version != apic_version[boot_cpu_physical_apicid]) {
1971 		pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
1972 			apic_version[boot_cpu_physical_apicid], cpu, version);
1973 	}
1974 
1975 	physid_set(apicid, phys_cpu_present_map);
1976 	if (apicid > max_physical_apicid)
1977 		max_physical_apicid = apicid;
1978 
1979 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
1980 	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
1981 	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
1982 #endif
1983 #ifdef CONFIG_X86_32
1984 	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
1985 		apic->x86_32_early_logical_apicid(cpu);
1986 #endif
1987 	set_cpu_possible(cpu, true);
1988 	set_cpu_present(cpu, true);
1989 }
1990 
hard_smp_processor_id(void)1991 int hard_smp_processor_id(void)
1992 {
1993 	return read_apic_id();
1994 }
1995 
default_init_apic_ldr(void)1996 void default_init_apic_ldr(void)
1997 {
1998 	unsigned long val;
1999 
2000 	apic_write(APIC_DFR, APIC_DFR_VALUE);
2001 	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
2002 	val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
2003 	apic_write(APIC_LDR, val);
2004 }
2005 
2006 #ifdef CONFIG_X86_32
default_x86_32_numa_cpu_node(int cpu)2007 int default_x86_32_numa_cpu_node(int cpu)
2008 {
2009 #ifdef CONFIG_NUMA
2010 	int apicid = early_per_cpu(x86_cpu_to_apicid, cpu);
2011 
2012 	if (apicid != BAD_APICID)
2013 		return __apicid_to_node[apicid];
2014 	return NUMA_NO_NODE;
2015 #else
2016 	return 0;
2017 #endif
2018 }
2019 #endif
2020 
2021 /*
2022  * Power management
2023  */
2024 #ifdef CONFIG_PM
2025 
2026 static struct {
2027 	/*
2028 	 * 'active' is true if the local APIC was enabled by us and
2029 	 * not the BIOS; this signifies that we are also responsible
2030 	 * for disabling it before entering apm/acpi suspend
2031 	 */
2032 	int active;
2033 	/* r/w apic fields */
2034 	unsigned int apic_id;
2035 	unsigned int apic_taskpri;
2036 	unsigned int apic_ldr;
2037 	unsigned int apic_dfr;
2038 	unsigned int apic_spiv;
2039 	unsigned int apic_lvtt;
2040 	unsigned int apic_lvtpc;
2041 	unsigned int apic_lvt0;
2042 	unsigned int apic_lvt1;
2043 	unsigned int apic_lvterr;
2044 	unsigned int apic_tmict;
2045 	unsigned int apic_tdcr;
2046 	unsigned int apic_thmr;
2047 } apic_pm_state;
2048 
lapic_suspend(void)2049 static int lapic_suspend(void)
2050 {
2051 	unsigned long flags;
2052 	int maxlvt;
2053 
2054 	if (!apic_pm_state.active)
2055 		return 0;
2056 
2057 	maxlvt = lapic_get_maxlvt();
2058 
2059 	apic_pm_state.apic_id = apic_read(APIC_ID);
2060 	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2061 	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2062 	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2063 	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2064 	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2065 	if (maxlvt >= 4)
2066 		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2067 	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2068 	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2069 	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2070 	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2071 	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2072 #ifdef CONFIG_X86_THERMAL_VECTOR
2073 	if (maxlvt >= 5)
2074 		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2075 #endif
2076 
2077 	local_irq_save(flags);
2078 	disable_local_APIC();
2079 
2080 	if (intr_remapping_enabled)
2081 		disable_intr_remapping();
2082 
2083 	local_irq_restore(flags);
2084 	return 0;
2085 }
2086 
lapic_resume(void)2087 static void lapic_resume(void)
2088 {
2089 	unsigned int l, h;
2090 	unsigned long flags;
2091 	int maxlvt, ret;
2092 	struct IO_APIC_route_entry **ioapic_entries = NULL;
2093 
2094 	if (!apic_pm_state.active)
2095 		return;
2096 
2097 	local_irq_save(flags);
2098 	if (intr_remapping_enabled) {
2099 		ioapic_entries = alloc_ioapic_entries();
2100 		if (!ioapic_entries) {
2101 			WARN(1, "Alloc ioapic_entries in lapic resume failed.");
2102 			goto restore;
2103 		}
2104 
2105 		ret = save_IO_APIC_setup(ioapic_entries);
2106 		if (ret) {
2107 			WARN(1, "Saving IO-APIC state failed: %d\n", ret);
2108 			free_ioapic_entries(ioapic_entries);
2109 			goto restore;
2110 		}
2111 
2112 		mask_IO_APIC_setup(ioapic_entries);
2113 		legacy_pic->mask_all();
2114 	}
2115 
2116 	if (x2apic_mode)
2117 		enable_x2apic();
2118 	else {
2119 		/*
2120 		 * Make sure the APICBASE points to the right address
2121 		 *
2122 		 * FIXME! This will be wrong if we ever support suspend on
2123 		 * SMP! We'll need to do this as part of the CPU restore!
2124 		 */
2125 		rdmsr(MSR_IA32_APICBASE, l, h);
2126 		l &= ~MSR_IA32_APICBASE_BASE;
2127 		l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2128 		wrmsr(MSR_IA32_APICBASE, l, h);
2129 	}
2130 
2131 	maxlvt = lapic_get_maxlvt();
2132 	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2133 	apic_write(APIC_ID, apic_pm_state.apic_id);
2134 	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2135 	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2136 	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2137 	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2138 	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2139 	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2140 #if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
2141 	if (maxlvt >= 5)
2142 		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2143 #endif
2144 	if (maxlvt >= 4)
2145 		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2146 	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2147 	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2148 	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2149 	apic_write(APIC_ESR, 0);
2150 	apic_read(APIC_ESR);
2151 	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2152 	apic_write(APIC_ESR, 0);
2153 	apic_read(APIC_ESR);
2154 
2155 	if (intr_remapping_enabled) {
2156 		reenable_intr_remapping(x2apic_mode);
2157 		legacy_pic->restore_mask();
2158 		restore_IO_APIC_setup(ioapic_entries);
2159 		free_ioapic_entries(ioapic_entries);
2160 	}
2161 restore:
2162 	local_irq_restore(flags);
2163 }
2164 
2165 /*
2166  * This device has no shutdown method - fully functioning local APICs
2167  * are needed on every CPU up until machine_halt/restart/poweroff.
2168  */
2169 
2170 static struct syscore_ops lapic_syscore_ops = {
2171 	.resume		= lapic_resume,
2172 	.suspend	= lapic_suspend,
2173 };
2174 
apic_pm_activate(void)2175 static void __cpuinit apic_pm_activate(void)
2176 {
2177 	apic_pm_state.active = 1;
2178 }
2179 
init_lapic_sysfs(void)2180 static int __init init_lapic_sysfs(void)
2181 {
2182 	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2183 	if (cpu_has_apic)
2184 		register_syscore_ops(&lapic_syscore_ops);
2185 
2186 	return 0;
2187 }
2188 
2189 /* local apic needs to resume before other devices access its registers. */
2190 core_initcall(init_lapic_sysfs);
2191 
2192 #else	/* CONFIG_PM */
2193 
apic_pm_activate(void)2194 static void apic_pm_activate(void) { }
2195 
2196 #endif	/* CONFIG_PM */
2197 
2198 #ifdef CONFIG_X86_64
2199 
apic_cluster_num(void)2200 static int __cpuinit apic_cluster_num(void)
2201 {
2202 	int i, clusters, zeros;
2203 	unsigned id;
2204 	u16 *bios_cpu_apicid;
2205 	DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
2206 
2207 	bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
2208 	bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
2209 
2210 	for (i = 0; i < nr_cpu_ids; i++) {
2211 		/* are we being called early in kernel startup? */
2212 		if (bios_cpu_apicid) {
2213 			id = bios_cpu_apicid[i];
2214 		} else if (i < nr_cpu_ids) {
2215 			if (cpu_present(i))
2216 				id = per_cpu(x86_bios_cpu_apicid, i);
2217 			else
2218 				continue;
2219 		} else
2220 			break;
2221 
2222 		if (id != BAD_APICID)
2223 			__set_bit(APIC_CLUSTERID(id), clustermap);
2224 	}
2225 
2226 	/* Problem:  Partially populated chassis may not have CPUs in some of
2227 	 * the APIC clusters they have been allocated.  Only present CPUs have
2228 	 * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap.
2229 	 * Since clusters are allocated sequentially, count zeros only if
2230 	 * they are bounded by ones.
2231 	 */
2232 	clusters = 0;
2233 	zeros = 0;
2234 	for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
2235 		if (test_bit(i, clustermap)) {
2236 			clusters += 1 + zeros;
2237 			zeros = 0;
2238 		} else
2239 			++zeros;
2240 	}
2241 
2242 	return clusters;
2243 }
2244 
2245 static int __cpuinitdata multi_checked;
2246 static int __cpuinitdata multi;
2247 
set_multi(const struct dmi_system_id * d)2248 static int __cpuinit set_multi(const struct dmi_system_id *d)
2249 {
2250 	if (multi)
2251 		return 0;
2252 	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2253 	multi = 1;
2254 	return 0;
2255 }
2256 
2257 static const __cpuinitconst struct dmi_system_id multi_dmi_table[] = {
2258 	{
2259 		.callback = set_multi,
2260 		.ident = "IBM System Summit2",
2261 		.matches = {
2262 			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2263 			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2264 		},
2265 	},
2266 	{}
2267 };
2268 
dmi_check_multi(void)2269 static void __cpuinit dmi_check_multi(void)
2270 {
2271 	if (multi_checked)
2272 		return;
2273 
2274 	dmi_check_system(multi_dmi_table);
2275 	multi_checked = 1;
2276 }
2277 
2278 /*
2279  * apic_is_clustered_box() -- Check if we can expect good TSC
2280  *
2281  * Thus far, the major user of this is IBM's Summit2 series:
2282  * Clustered boxes may have unsynced TSC problems if they are
2283  * multi-chassis.
2284  * Use DMI to check them
2285  */
apic_is_clustered_box(void)2286 __cpuinit int apic_is_clustered_box(void)
2287 {
2288 	dmi_check_multi();
2289 	if (multi)
2290 		return 1;
2291 
2292 	if (!is_vsmp_box())
2293 		return 0;
2294 
2295 	/*
2296 	 * ScaleMP vSMPowered boxes have one cluster per board and TSCs are
2297 	 * not guaranteed to be synced between boards
2298 	 */
2299 	if (apic_cluster_num() > 1)
2300 		return 1;
2301 
2302 	return 0;
2303 }
2304 #endif
2305 
2306 /*
2307  * APIC command line parameters
2308  */
setup_disableapic(char * arg)2309 static int __init setup_disableapic(char *arg)
2310 {
2311 	disable_apic = 1;
2312 	setup_clear_cpu_cap(X86_FEATURE_APIC);
2313 	return 0;
2314 }
2315 early_param("disableapic", setup_disableapic);
2316 
2317 /* same as disableapic, for compatibility */
setup_nolapic(char * arg)2318 static int __init setup_nolapic(char *arg)
2319 {
2320 	return setup_disableapic(arg);
2321 }
2322 early_param("nolapic", setup_nolapic);
2323 
parse_lapic_timer_c2_ok(char * arg)2324 static int __init parse_lapic_timer_c2_ok(char *arg)
2325 {
2326 	local_apic_timer_c2_ok = 1;
2327 	return 0;
2328 }
2329 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2330 
parse_disable_apic_timer(char * arg)2331 static int __init parse_disable_apic_timer(char *arg)
2332 {
2333 	disable_apic_timer = 1;
2334 	return 0;
2335 }
2336 early_param("noapictimer", parse_disable_apic_timer);
2337 
parse_nolapic_timer(char * arg)2338 static int __init parse_nolapic_timer(char *arg)
2339 {
2340 	disable_apic_timer = 1;
2341 	return 0;
2342 }
2343 early_param("nolapic_timer", parse_nolapic_timer);
2344 
apic_set_verbosity(char * arg)2345 static int __init apic_set_verbosity(char *arg)
2346 {
2347 	if (!arg)  {
2348 #ifdef CONFIG_X86_64
2349 		skip_ioapic_setup = 0;
2350 		return 0;
2351 #endif
2352 		return -EINVAL;
2353 	}
2354 
2355 	if (strcmp("debug", arg) == 0)
2356 		apic_verbosity = APIC_DEBUG;
2357 	else if (strcmp("verbose", arg) == 0)
2358 		apic_verbosity = APIC_VERBOSE;
2359 	else {
2360 		pr_warning("APIC Verbosity level %s not recognised"
2361 			" use apic=verbose or apic=debug\n", arg);
2362 		return -EINVAL;
2363 	}
2364 
2365 	return 0;
2366 }
2367 early_param("apic", apic_set_verbosity);
2368 
lapic_insert_resource(void)2369 static int __init lapic_insert_resource(void)
2370 {
2371 	if (!apic_phys)
2372 		return -1;
2373 
2374 	/* Put local APIC into the resource map. */
2375 	lapic_resource.start = apic_phys;
2376 	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2377 	insert_resource(&iomem_resource, &lapic_resource);
2378 
2379 	return 0;
2380 }
2381 
2382 /*
2383  * need call insert after e820_reserve_resources()
2384  * that is using request_resource
2385  */
2386 late_initcall(lapic_insert_resource);
2387