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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Local APIC handling, local APIC timers
4 *
5 * (c) 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
6 *
7 * Fixes
8 * Maciej W. Rozycki : Bits for genuine 82489DX APICs;
9 * thanks to Eric Gilmore
10 * and Rolf G. Tews
11 * for testing these extensively.
12 * Maciej W. Rozycki : Various updates and fixes.
13 * Mikael Pettersson : Power Management for UP-APIC.
14 * Pavel Machek and
15 * Mikael Pettersson : PM converted to driver model.
16 */
17
18#include <linux/perf_event.h>
19#include <linux/kernel_stat.h>
20#include <linux/mc146818rtc.h>
21#include <linux/acpi_pmtmr.h>
22#include <linux/clockchips.h>
23#include <linux/interrupt.h>
24#include <linux/memblock.h>
25#include <linux/ftrace.h>
26#include <linux/ioport.h>
27#include <linux/export.h>
28#include <linux/syscore_ops.h>
29#include <linux/delay.h>
30#include <linux/timex.h>
31#include <linux/i8253.h>
32#include <linux/dmar.h>
33#include <linux/init.h>
34#include <linux/cpu.h>
35#include <linux/dmi.h>
36#include <linux/smp.h>
37#include <linux/mm.h>
38
39#include <asm/trace/irq_vectors.h>
40#include <asm/irq_remapping.h>
41#include <asm/perf_event.h>
42#include <asm/x86_init.h>
43#include <asm/pgalloc.h>
44#include <linux/atomic.h>
45#include <asm/mpspec.h>
46#include <asm/i8259.h>
47#include <asm/proto.h>
48#include <asm/traps.h>
49#include <asm/apic.h>
50#include <asm/io_apic.h>
51#include <asm/desc.h>
52#include <asm/hpet.h>
53#include <asm/mtrr.h>
54#include <asm/time.h>
55#include <asm/smp.h>
56#include <asm/mce.h>
57#include <asm/tsc.h>
58#include <asm/hypervisor.h>
59#include <asm/cpu_device_id.h>
60#include <asm/intel-family.h>
61#include <asm/irq_regs.h>
62
63unsigned int num_processors;
64
65unsigned disabled_cpus;
66
67/* Processor that is doing the boot up */
68unsigned int boot_cpu_physical_apicid __ro_after_init = -1U;
69EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
70
71u8 boot_cpu_apic_version __ro_after_init;
72
73/*
74 * The highest APIC ID seen during enumeration.
75 */
76static unsigned int max_physical_apicid;
77
78/*
79 * Bitmask of physically existing CPUs:
80 */
81physid_mask_t phys_cpu_present_map;
82
83/*
84 * Processor to be disabled specified by kernel parameter
85 * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
86 * avoid undefined behaviour caused by sending INIT from AP to BSP.
87 */
88static unsigned int disabled_cpu_apicid __ro_after_init = BAD_APICID;
89
90/*
91 * This variable controls which CPUs receive external NMIs. By default,
92 * external NMIs are delivered only to the BSP.
93 */
94static int apic_extnmi __ro_after_init = APIC_EXTNMI_BSP;
95
96/*
97 * Map cpu index to physical APIC ID
98 */
99DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid, BAD_APICID);
100DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_bios_cpu_apicid, BAD_APICID);
101DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, U32_MAX);
102EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
103EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
104EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
105
106#ifdef CONFIG_X86_32
107
108/*
109 * On x86_32, the mapping between cpu and logical apicid may vary
110 * depending on apic in use. The following early percpu variable is
111 * used for the mapping. This is where the behaviors of x86_64 and 32
112 * actually diverge. Let's keep it ugly for now.
113 */
114DEFINE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid, BAD_APICID);
115
116/* Local APIC was disabled by the BIOS and enabled by the kernel */
117static int enabled_via_apicbase __ro_after_init;
118
119/*
120 * Handle interrupt mode configuration register (IMCR).
121 * This register controls whether the interrupt signals
122 * that reach the BSP come from the master PIC or from the
123 * local APIC. Before entering Symmetric I/O Mode, either
124 * the BIOS or the operating system must switch out of
125 * PIC Mode by changing the IMCR.
126 */
127static inline void imcr_pic_to_apic(void)
128{
129 /* select IMCR register */
130 outb(0x70, 0x22);
131 /* NMI and 8259 INTR go through APIC */
132 outb(0x01, 0x23);
133}
134
135static inline void imcr_apic_to_pic(void)
136{
137 /* select IMCR register */
138 outb(0x70, 0x22);
139 /* NMI and 8259 INTR go directly to BSP */
140 outb(0x00, 0x23);
141}
142#endif
143
144/*
145 * Knob to control our willingness to enable the local APIC.
146 *
147 * +1=force-enable
148 */
149static int force_enable_local_apic __initdata;
150
151/*
152 * APIC command line parameters
153 */
154static int __init parse_lapic(char *arg)
155{
156 if (IS_ENABLED(CONFIG_X86_32) && !arg)
157 force_enable_local_apic = 1;
158 else if (arg && !strncmp(arg, "notscdeadline", 13))
159 setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
160 return 0;
161}
162early_param("lapic", parse_lapic);
163
164#ifdef CONFIG_X86_64
165static int apic_calibrate_pmtmr __initdata;
166static __init int setup_apicpmtimer(char *s)
167{
168 apic_calibrate_pmtmr = 1;
169 notsc_setup(NULL);
170 return 0;
171}
172__setup("apicpmtimer", setup_apicpmtimer);
173#endif
174
175unsigned long mp_lapic_addr __ro_after_init;
176int disable_apic __ro_after_init;
177/* Disable local APIC timer from the kernel commandline or via dmi quirk */
178static int disable_apic_timer __initdata;
179/* Local APIC timer works in C2 */
180int local_apic_timer_c2_ok __ro_after_init;
181EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
182
183/*
184 * Debug level, exported for io_apic.c
185 */
186int apic_verbosity __ro_after_init;
187
188int pic_mode __ro_after_init;
189
190/* Have we found an MP table */
191int smp_found_config __ro_after_init;
192
193static struct resource lapic_resource = {
194 .name = "Local APIC",
195 .flags = IORESOURCE_MEM | IORESOURCE_BUSY,
196};
197
198unsigned int lapic_timer_period = 0;
199
200static void apic_pm_activate(void);
201
202static unsigned long apic_phys __ro_after_init;
203
204/*
205 * Get the LAPIC version
206 */
207static inline int lapic_get_version(void)
208{
209 return GET_APIC_VERSION(apic_read(APIC_LVR));
210}
211
212/*
213 * Check, if the APIC is integrated or a separate chip
214 */
215static inline int lapic_is_integrated(void)
216{
217 return APIC_INTEGRATED(lapic_get_version());
218}
219
220/*
221 * Check, whether this is a modern or a first generation APIC
222 */
223static int modern_apic(void)
224{
225 /* AMD systems use old APIC versions, so check the CPU */
226 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
227 boot_cpu_data.x86 >= 0xf)
228 return 1;
229
230 /* Hygon systems use modern APIC */
231 if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
232 return 1;
233
234 return lapic_get_version() >= 0x14;
235}
236
237/*
238 * right after this call apic become NOOP driven
239 * so apic->write/read doesn't do anything
240 */
241static void __init apic_disable(void)
242{
243 pr_info("APIC: switched to apic NOOP\n");
244 apic = &apic_noop;
245}
246
247void native_apic_wait_icr_idle(void)
248{
249 while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
250 cpu_relax();
251}
252
253u32 native_safe_apic_wait_icr_idle(void)
254{
255 u32 send_status;
256 int timeout;
257
258 timeout = 0;
259 do {
260 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
261 if (!send_status)
262 break;
263 inc_irq_stat(icr_read_retry_count);
264 udelay(100);
265 } while (timeout++ < 1000);
266
267 return send_status;
268}
269
270void native_apic_icr_write(u32 low, u32 id)
271{
272 unsigned long flags;
273
274 local_irq_save(flags);
275 apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
276 apic_write(APIC_ICR, low);
277 local_irq_restore(flags);
278}
279
280u64 native_apic_icr_read(void)
281{
282 u32 icr1, icr2;
283
284 icr2 = apic_read(APIC_ICR2);
285 icr1 = apic_read(APIC_ICR);
286
287 return icr1 | ((u64)icr2 << 32);
288}
289
290#ifdef CONFIG_X86_32
291/**
292 * get_physical_broadcast - Get number of physical broadcast IDs
293 */
294int get_physical_broadcast(void)
295{
296 return modern_apic() ? 0xff : 0xf;
297}
298#endif
299
300/**
301 * lapic_get_maxlvt - get the maximum number of local vector table entries
302 */
303int lapic_get_maxlvt(void)
304{
305 /*
306 * - we always have APIC integrated on 64bit mode
307 * - 82489DXs do not report # of LVT entries
308 */
309 return lapic_is_integrated() ? GET_APIC_MAXLVT(apic_read(APIC_LVR)) : 2;
310}
311
312/*
313 * Local APIC timer
314 */
315
316/* Clock divisor */
317#define APIC_DIVISOR 16
318#define TSC_DIVISOR 8
319
320/*
321 * This function sets up the local APIC timer, with a timeout of
322 * 'clocks' APIC bus clock. During calibration we actually call
323 * this function twice on the boot CPU, once with a bogus timeout
324 * value, second time for real. The other (noncalibrating) CPUs
325 * call this function only once, with the real, calibrated value.
326 *
327 * We do reads before writes even if unnecessary, to get around the
328 * P5 APIC double write bug.
329 */
330static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
331{
332 unsigned int lvtt_value, tmp_value;
333
334 lvtt_value = LOCAL_TIMER_VECTOR;
335 if (!oneshot)
336 lvtt_value |= APIC_LVT_TIMER_PERIODIC;
337 else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
338 lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE;
339
340 if (!lapic_is_integrated())
341 lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
342
343 if (!irqen)
344 lvtt_value |= APIC_LVT_MASKED;
345
346 apic_write(APIC_LVTT, lvtt_value);
347
348 if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) {
349 /*
350 * See Intel SDM: TSC-Deadline Mode chapter. In xAPIC mode,
351 * writing to the APIC LVTT and TSC_DEADLINE MSR isn't serialized.
352 * According to Intel, MFENCE can do the serialization here.
353 */
354 asm volatile("mfence" : : : "memory");
355
356 printk_once(KERN_DEBUG "TSC deadline timer enabled\n");
357 return;
358 }
359
360 /*
361 * Divide PICLK by 16
362 */
363 tmp_value = apic_read(APIC_TDCR);
364 apic_write(APIC_TDCR,
365 (tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
366 APIC_TDR_DIV_16);
367
368 if (!oneshot)
369 apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
370}
371
372/*
373 * Setup extended LVT, AMD specific
374 *
375 * Software should use the LVT offsets the BIOS provides. The offsets
376 * are determined by the subsystems using it like those for MCE
377 * threshold or IBS. On K8 only offset 0 (APIC500) and MCE interrupts
378 * are supported. Beginning with family 10h at least 4 offsets are
379 * available.
380 *
381 * Since the offsets must be consistent for all cores, we keep track
382 * of the LVT offsets in software and reserve the offset for the same
383 * vector also to be used on other cores. An offset is freed by
384 * setting the entry to APIC_EILVT_MASKED.
385 *
386 * If the BIOS is right, there should be no conflicts. Otherwise a
387 * "[Firmware Bug]: ..." error message is generated. However, if
388 * software does not properly determines the offsets, it is not
389 * necessarily a BIOS bug.
390 */
391
392static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
393
394static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
395{
396 return (old & APIC_EILVT_MASKED)
397 || (new == APIC_EILVT_MASKED)
398 || ((new & ~APIC_EILVT_MASKED) == old);
399}
400
401static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
402{
403 unsigned int rsvd, vector;
404
405 if (offset >= APIC_EILVT_NR_MAX)
406 return ~0;
407
408 rsvd = atomic_read(&eilvt_offsets[offset]);
409 do {
410 vector = rsvd & ~APIC_EILVT_MASKED; /* 0: unassigned */
411 if (vector && !eilvt_entry_is_changeable(vector, new))
412 /* may not change if vectors are different */
413 return rsvd;
414 rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new);
415 } while (rsvd != new);
416
417 rsvd &= ~APIC_EILVT_MASKED;
418 if (rsvd && rsvd != vector)
419 pr_info("LVT offset %d assigned for vector 0x%02x\n",
420 offset, rsvd);
421
422 return new;
423}
424
425/*
426 * If mask=1, the LVT entry does not generate interrupts while mask=0
427 * enables the vector. See also the BKDGs. Must be called with
428 * preemption disabled.
429 */
430
431int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
432{
433 unsigned long reg = APIC_EILVTn(offset);
434 unsigned int new, old, reserved;
435
436 new = (mask << 16) | (msg_type << 8) | vector;
437 old = apic_read(reg);
438 reserved = reserve_eilvt_offset(offset, new);
439
440 if (reserved != new) {
441 pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
442 "vector 0x%x, but the register is already in use for "
443 "vector 0x%x on another cpu\n",
444 smp_processor_id(), reg, offset, new, reserved);
445 return -EINVAL;
446 }
447
448 if (!eilvt_entry_is_changeable(old, new)) {
449 pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
450 "vector 0x%x, but the register is already in use for "
451 "vector 0x%x on this cpu\n",
452 smp_processor_id(), reg, offset, new, old);
453 return -EBUSY;
454 }
455
456 apic_write(reg, new);
457
458 return 0;
459}
460EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
461
462/*
463 * Program the next event, relative to now
464 */
465static int lapic_next_event(unsigned long delta,
466 struct clock_event_device *evt)
467{
468 apic_write(APIC_TMICT, delta);
469 return 0;
470}
471
472static int lapic_next_deadline(unsigned long delta,
473 struct clock_event_device *evt)
474{
475 u64 tsc;
476
477 tsc = rdtsc();
478 wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR));
479 return 0;
480}
481
482static int lapic_timer_shutdown(struct clock_event_device *evt)
483{
484 unsigned int v;
485
486 /* Lapic used as dummy for broadcast ? */
487 if (evt->features & CLOCK_EVT_FEAT_DUMMY)
488 return 0;
489
490 v = apic_read(APIC_LVTT);
491 v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
492 apic_write(APIC_LVTT, v);
493 apic_write(APIC_TMICT, 0);
494 return 0;
495}
496
497static inline int
498lapic_timer_set_periodic_oneshot(struct clock_event_device *evt, bool oneshot)
499{
500 /* Lapic used as dummy for broadcast ? */
501 if (evt->features & CLOCK_EVT_FEAT_DUMMY)
502 return 0;
503
504 __setup_APIC_LVTT(lapic_timer_period, oneshot, 1);
505 return 0;
506}
507
508static int lapic_timer_set_periodic(struct clock_event_device *evt)
509{
510 return lapic_timer_set_periodic_oneshot(evt, false);
511}
512
513static int lapic_timer_set_oneshot(struct clock_event_device *evt)
514{
515 return lapic_timer_set_periodic_oneshot(evt, true);
516}
517
518/*
519 * Local APIC timer broadcast function
520 */
521static void lapic_timer_broadcast(const struct cpumask *mask)
522{
523#ifdef CONFIG_SMP
524 apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
525#endif
526}
527
528
529/*
530 * The local apic timer can be used for any function which is CPU local.
531 */
532static struct clock_event_device lapic_clockevent = {
533 .name = "lapic",
534 .features = CLOCK_EVT_FEAT_PERIODIC |
535 CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP
536 | CLOCK_EVT_FEAT_DUMMY,
537 .shift = 32,
538 .set_state_shutdown = lapic_timer_shutdown,
539 .set_state_periodic = lapic_timer_set_periodic,
540 .set_state_oneshot = lapic_timer_set_oneshot,
541 .set_state_oneshot_stopped = lapic_timer_shutdown,
542 .set_next_event = lapic_next_event,
543 .broadcast = lapic_timer_broadcast,
544 .rating = 100,
545 .irq = -1,
546};
547static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
548
549#define DEADLINE_MODEL_MATCH_FUNC(model, func) \
550 { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&func }
551
552#define DEADLINE_MODEL_MATCH_REV(model, rev) \
553 { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)rev }
554
555static u32 hsx_deadline_rev(void)
556{
557 switch (boot_cpu_data.x86_stepping) {
558 case 0x02: return 0x3a; /* EP */
559 case 0x04: return 0x0f; /* EX */
560 }
561
562 return ~0U;
563}
564
565static u32 bdx_deadline_rev(void)
566{
567 switch (boot_cpu_data.x86_stepping) {
568 case 0x02: return 0x00000011;
569 case 0x03: return 0x0700000e;
570 case 0x04: return 0x0f00000c;
571 case 0x05: return 0x0e000003;
572 }
573
574 return ~0U;
575}
576
577static u32 skx_deadline_rev(void)
578{
579 switch (boot_cpu_data.x86_stepping) {
580 case 0x03: return 0x01000136;
581 case 0x04: return 0x02000014;
582 }
583
584 if (boot_cpu_data.x86_stepping > 4)
585 return 0;
586
587 return ~0U;
588}
589
590static const struct x86_cpu_id deadline_match[] = {
591 DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_HASWELL_X, hsx_deadline_rev),
592 DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_X, 0x0b000020),
593 DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_BROADWELL_D, bdx_deadline_rev),
594 DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_SKYLAKE_X, skx_deadline_rev),
595
596 DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL, 0x22),
597 DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_L, 0x20),
598 DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_G, 0x17),
599
600 DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL, 0x25),
601 DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_G, 0x17),
602
603 DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_L, 0xb2),
604 DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE, 0xb2),
605
606 DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_L, 0x52),
607 DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE, 0x52),
608
609 {},
610};
611
612static void apic_check_deadline_errata(void)
613{
614 const struct x86_cpu_id *m;
615 u32 rev;
616
617 if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER) ||
618 boot_cpu_has(X86_FEATURE_HYPERVISOR))
619 return;
620
621 m = x86_match_cpu(deadline_match);
622 if (!m)
623 return;
624
625 /*
626 * Function pointers will have the MSB set due to address layout,
627 * immediate revisions will not.
628 */
629 if ((long)m->driver_data < 0)
630 rev = ((u32 (*)(void))(m->driver_data))();
631 else
632 rev = (u32)m->driver_data;
633
634 if (boot_cpu_data.microcode >= rev)
635 return;
636
637 setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
638 pr_err(FW_BUG "TSC_DEADLINE disabled due to Errata; "
639 "please update microcode to version: 0x%x (or later)\n", rev);
640}
641
642/*
643 * Setup the local APIC timer for this CPU. Copy the initialized values
644 * of the boot CPU and register the clock event in the framework.
645 */
646static void setup_APIC_timer(void)
647{
648 struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
649
650 if (this_cpu_has(X86_FEATURE_ARAT)) {
651 lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
652 /* Make LAPIC timer preferrable over percpu HPET */
653 lapic_clockevent.rating = 150;
654 }
655
656 memcpy(levt, &lapic_clockevent, sizeof(*levt));
657 levt->cpumask = cpumask_of(smp_processor_id());
658
659 if (this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
660 levt->name = "lapic-deadline";
661 levt->features &= ~(CLOCK_EVT_FEAT_PERIODIC |
662 CLOCK_EVT_FEAT_DUMMY);
663 levt->set_next_event = lapic_next_deadline;
664 clockevents_config_and_register(levt,
665 tsc_khz * (1000 / TSC_DIVISOR),
666 0xF, ~0UL);
667 } else
668 clockevents_register_device(levt);
669}
670
671/*
672 * Install the updated TSC frequency from recalibration at the TSC
673 * deadline clockevent devices.
674 */
675static void __lapic_update_tsc_freq(void *info)
676{
677 struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
678
679 if (!this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
680 return;
681
682 clockevents_update_freq(levt, tsc_khz * (1000 / TSC_DIVISOR));
683}
684
685void lapic_update_tsc_freq(void)
686{
687 /*
688 * The clockevent device's ->mult and ->shift can both be
689 * changed. In order to avoid races, schedule the frequency
690 * update code on each CPU.
691 */
692 on_each_cpu(__lapic_update_tsc_freq, NULL, 0);
693}
694
695/*
696 * In this functions we calibrate APIC bus clocks to the external timer.
697 *
698 * We want to do the calibration only once since we want to have local timer
699 * irqs syncron. CPUs connected by the same APIC bus have the very same bus
700 * frequency.
701 *
702 * This was previously done by reading the PIT/HPET and waiting for a wrap
703 * around to find out, that a tick has elapsed. I have a box, where the PIT
704 * readout is broken, so it never gets out of the wait loop again. This was
705 * also reported by others.
706 *
707 * Monitoring the jiffies value is inaccurate and the clockevents
708 * infrastructure allows us to do a simple substitution of the interrupt
709 * handler.
710 *
711 * The calibration routine also uses the pm_timer when possible, as the PIT
712 * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
713 * back to normal later in the boot process).
714 */
715
716#define LAPIC_CAL_LOOPS (HZ/10)
717
718static __initdata int lapic_cal_loops = -1;
719static __initdata long lapic_cal_t1, lapic_cal_t2;
720static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
721static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
722static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
723
724/*
725 * Temporary interrupt handler and polled calibration function.
726 */
727static void __init lapic_cal_handler(struct clock_event_device *dev)
728{
729 unsigned long long tsc = 0;
730 long tapic = apic_read(APIC_TMCCT);
731 unsigned long pm = acpi_pm_read_early();
732
733 if (boot_cpu_has(X86_FEATURE_TSC))
734 tsc = rdtsc();
735
736 switch (lapic_cal_loops++) {
737 case 0:
738 lapic_cal_t1 = tapic;
739 lapic_cal_tsc1 = tsc;
740 lapic_cal_pm1 = pm;
741 lapic_cal_j1 = jiffies;
742 break;
743
744 case LAPIC_CAL_LOOPS:
745 lapic_cal_t2 = tapic;
746 lapic_cal_tsc2 = tsc;
747 if (pm < lapic_cal_pm1)
748 pm += ACPI_PM_OVRRUN;
749 lapic_cal_pm2 = pm;
750 lapic_cal_j2 = jiffies;
751 break;
752 }
753}
754
755static int __init
756calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
757{
758 const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
759 const long pm_thresh = pm_100ms / 100;
760 unsigned long mult;
761 u64 res;
762
763#ifndef CONFIG_X86_PM_TIMER
764 return -1;
765#endif
766
767 apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
768
769 /* Check, if the PM timer is available */
770 if (!deltapm)
771 return -1;
772
773 mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
774
775 if (deltapm > (pm_100ms - pm_thresh) &&
776 deltapm < (pm_100ms + pm_thresh)) {
777 apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
778 return 0;
779 }
780
781 res = (((u64)deltapm) * mult) >> 22;
782 do_div(res, 1000000);
783 pr_warning("APIC calibration not consistent "
784 "with PM-Timer: %ldms instead of 100ms\n",(long)res);
785
786 /* Correct the lapic counter value */
787 res = (((u64)(*delta)) * pm_100ms);
788 do_div(res, deltapm);
789 pr_info("APIC delta adjusted to PM-Timer: "
790 "%lu (%ld)\n", (unsigned long)res, *delta);
791 *delta = (long)res;
792
793 /* Correct the tsc counter value */
794 if (boot_cpu_has(X86_FEATURE_TSC)) {
795 res = (((u64)(*deltatsc)) * pm_100ms);
796 do_div(res, deltapm);
797 apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
798 "PM-Timer: %lu (%ld)\n",
799 (unsigned long)res, *deltatsc);
800 *deltatsc = (long)res;
801 }
802
803 return 0;
804}
805
806static int __init lapic_init_clockevent(void)
807{
808 if (!lapic_timer_period)
809 return -1;
810
811 /* Calculate the scaled math multiplication factor */
812 lapic_clockevent.mult = div_sc(lapic_timer_period/APIC_DIVISOR,
813 TICK_NSEC, lapic_clockevent.shift);
814 lapic_clockevent.max_delta_ns =
815 clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
816 lapic_clockevent.max_delta_ticks = 0x7FFFFFFF;
817 lapic_clockevent.min_delta_ns =
818 clockevent_delta2ns(0xF, &lapic_clockevent);
819 lapic_clockevent.min_delta_ticks = 0xF;
820
821 return 0;
822}
823
824bool __init apic_needs_pit(void)
825{
826 /*
827 * If the frequencies are not known, PIT is required for both TSC
828 * and apic timer calibration.
829 */
830 if (!tsc_khz || !cpu_khz)
831 return true;
832
833 /* Is there an APIC at all? */
834 if (!boot_cpu_has(X86_FEATURE_APIC))
835 return true;
836
837 /* Virt guests may lack ARAT, but still have DEADLINE */
838 if (!boot_cpu_has(X86_FEATURE_ARAT))
839 return true;
840
841 /* Deadline timer is based on TSC so no further PIT action required */
842 if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
843 return false;
844
845 /* APIC timer disabled? */
846 if (disable_apic_timer)
847 return true;
848 /*
849 * The APIC timer frequency is known already, no PIT calibration
850 * required. If unknown, let the PIT be initialized.
851 */
852 return lapic_timer_period == 0;
853}
854
855static int __init calibrate_APIC_clock(void)
856{
857 struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
858 u64 tsc_perj = 0, tsc_start = 0;
859 unsigned long jif_start;
860 unsigned long deltaj;
861 long delta, deltatsc;
862 int pm_referenced = 0;
863
864 if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
865 return 0;
866
867 /*
868 * Check if lapic timer has already been calibrated by platform
869 * specific routine, such as tsc calibration code. If so just fill
870 * in the clockevent structure and return.
871 */
872 if (!lapic_init_clockevent()) {
873 apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
874 lapic_timer_period);
875 /*
876 * Direct calibration methods must have an always running
877 * local APIC timer, no need for broadcast timer.
878 */
879 lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
880 return 0;
881 }
882
883 apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
884 "calibrating APIC timer ...\n");
885
886 /*
887 * There are platforms w/o global clockevent devices. Instead of
888 * making the calibration conditional on that, use a polling based
889 * approach everywhere.
890 */
891 local_irq_disable();
892
893 /*
894 * Setup the APIC counter to maximum. There is no way the lapic
895 * can underflow in the 100ms detection time frame
896 */
897 __setup_APIC_LVTT(0xffffffff, 0, 0);
898
899 /*
900 * Methods to terminate the calibration loop:
901 * 1) Global clockevent if available (jiffies)
902 * 2) TSC if available and frequency is known
903 */
904 jif_start = READ_ONCE(jiffies);
905
906 if (tsc_khz) {
907 tsc_start = rdtsc();
908 tsc_perj = div_u64((u64)tsc_khz * 1000, HZ);
909 }
910
911 /*
912 * Enable interrupts so the tick can fire, if a global
913 * clockevent device is available
914 */
915 local_irq_enable();
916
917 while (lapic_cal_loops <= LAPIC_CAL_LOOPS) {
918 /* Wait for a tick to elapse */
919 while (1) {
920 if (tsc_khz) {
921 u64 tsc_now = rdtsc();
922 if ((tsc_now - tsc_start) >= tsc_perj) {
923 tsc_start += tsc_perj;
924 break;
925 }
926 } else {
927 unsigned long jif_now = READ_ONCE(jiffies);
928
929 if (time_after(jif_now, jif_start)) {
930 jif_start = jif_now;
931 break;
932 }
933 }
934 cpu_relax();
935 }
936
937 /* Invoke the calibration routine */
938 local_irq_disable();
939 lapic_cal_handler(NULL);
940 local_irq_enable();
941 }
942
943 local_irq_disable();
944
945 /* Build delta t1-t2 as apic timer counts down */
946 delta = lapic_cal_t1 - lapic_cal_t2;
947 apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
948
949 deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
950
951 /* we trust the PM based calibration if possible */
952 pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
953 &delta, &deltatsc);
954
955 lapic_timer_period = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
956 lapic_init_clockevent();
957
958 apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
959 apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
960 apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
961 lapic_timer_period);
962
963 if (boot_cpu_has(X86_FEATURE_TSC)) {
964 apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
965 "%ld.%04ld MHz.\n",
966 (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
967 (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
968 }
969
970 apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
971 "%u.%04u MHz.\n",
972 lapic_timer_period / (1000000 / HZ),
973 lapic_timer_period % (1000000 / HZ));
974
975 /*
976 * Do a sanity check on the APIC calibration result
977 */
978 if (lapic_timer_period < (1000000 / HZ)) {
979 local_irq_enable();
980 pr_warning("APIC frequency too slow, disabling apic timer\n");
981 return -1;
982 }
983
984 levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
985
986 /*
987 * PM timer calibration failed or not turned on so lets try APIC
988 * timer based calibration, if a global clockevent device is
989 * available.
990 */
991 if (!pm_referenced && global_clock_event) {
992 apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
993
994 /*
995 * Setup the apic timer manually
996 */
997 levt->event_handler = lapic_cal_handler;
998 lapic_timer_set_periodic(levt);
999 lapic_cal_loops = -1;
1000
1001 /* Let the interrupts run */
1002 local_irq_enable();
1003
1004 while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
1005 cpu_relax();
1006
1007 /* Stop the lapic timer */
1008 local_irq_disable();
1009 lapic_timer_shutdown(levt);
1010
1011 /* Jiffies delta */
1012 deltaj = lapic_cal_j2 - lapic_cal_j1;
1013 apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
1014
1015 /* Check, if the jiffies result is consistent */
1016 if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
1017 apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
1018 else
1019 levt->features |= CLOCK_EVT_FEAT_DUMMY;
1020 }
1021 local_irq_enable();
1022
1023 if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
1024 pr_warning("APIC timer disabled due to verification failure\n");
1025 return -1;
1026 }
1027
1028 return 0;
1029}
1030
1031/*
1032 * Setup the boot APIC
1033 *
1034 * Calibrate and verify the result.
1035 */
1036void __init setup_boot_APIC_clock(void)
1037{
1038 /*
1039 * The local apic timer can be disabled via the kernel
1040 * commandline or from the CPU detection code. Register the lapic
1041 * timer as a dummy clock event source on SMP systems, so the
1042 * broadcast mechanism is used. On UP systems simply ignore it.
1043 */
1044 if (disable_apic_timer) {
1045 pr_info("Disabling APIC timer\n");
1046 /* No broadcast on UP ! */
1047 if (num_possible_cpus() > 1) {
1048 lapic_clockevent.mult = 1;
1049 setup_APIC_timer();
1050 }
1051 return;
1052 }
1053
1054 if (calibrate_APIC_clock()) {
1055 /* No broadcast on UP ! */
1056 if (num_possible_cpus() > 1)
1057 setup_APIC_timer();
1058 return;
1059 }
1060
1061 /*
1062 * If nmi_watchdog is set to IO_APIC, we need the
1063 * PIT/HPET going. Otherwise register lapic as a dummy
1064 * device.
1065 */
1066 lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
1067
1068 /* Setup the lapic or request the broadcast */
1069 setup_APIC_timer();
1070 amd_e400_c1e_apic_setup();
1071}
1072
1073void setup_secondary_APIC_clock(void)
1074{
1075 setup_APIC_timer();
1076 amd_e400_c1e_apic_setup();
1077}
1078
1079/*
1080 * The guts of the apic timer interrupt
1081 */
1082static void local_apic_timer_interrupt(void)
1083{
1084 struct clock_event_device *evt = this_cpu_ptr(&lapic_events);
1085
1086 /*
1087 * Normally we should not be here till LAPIC has been initialized but
1088 * in some cases like kdump, its possible that there is a pending LAPIC
1089 * timer interrupt from previous kernel's context and is delivered in
1090 * new kernel the moment interrupts are enabled.
1091 *
1092 * Interrupts are enabled early and LAPIC is setup much later, hence
1093 * its possible that when we get here evt->event_handler is NULL.
1094 * Check for event_handler being NULL and discard the interrupt as
1095 * spurious.
1096 */
1097 if (!evt->event_handler) {
1098 pr_warning("Spurious LAPIC timer interrupt on cpu %d\n",
1099 smp_processor_id());
1100 /* Switch it off */
1101 lapic_timer_shutdown(evt);
1102 return;
1103 }
1104
1105 /*
1106 * the NMI deadlock-detector uses this.
1107 */
1108 inc_irq_stat(apic_timer_irqs);
1109
1110 evt->event_handler(evt);
1111}
1112
1113/*
1114 * Local APIC timer interrupt. This is the most natural way for doing
1115 * local interrupts, but local timer interrupts can be emulated by
1116 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
1117 *
1118 * [ if a single-CPU system runs an SMP kernel then we call the local
1119 * interrupt as well. Thus we cannot inline the local irq ... ]
1120 */
1121__visible void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
1122{
1123 struct pt_regs *old_regs = set_irq_regs(regs);
1124
1125 /*
1126 * NOTE! We'd better ACK the irq immediately,
1127 * because timer handling can be slow.
1128 *
1129 * update_process_times() expects us to have done irq_enter().
1130 * Besides, if we don't timer interrupts ignore the global
1131 * interrupt lock, which is the WrongThing (tm) to do.
1132 */
1133 entering_ack_irq();
1134 trace_local_timer_entry(LOCAL_TIMER_VECTOR);
1135 local_apic_timer_interrupt();
1136 trace_local_timer_exit(LOCAL_TIMER_VECTOR);
1137 exiting_irq();
1138
1139 set_irq_regs(old_regs);
1140}
1141
1142int setup_profiling_timer(unsigned int multiplier)
1143{
1144 return -EINVAL;
1145}
1146
1147/*
1148 * Local APIC start and shutdown
1149 */
1150
1151/**
1152 * clear_local_APIC - shutdown the local APIC
1153 *
1154 * This is called, when a CPU is disabled and before rebooting, so the state of
1155 * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
1156 * leftovers during boot.
1157 */
1158void clear_local_APIC(void)
1159{
1160 int maxlvt;
1161 u32 v;
1162
1163 /* APIC hasn't been mapped yet */
1164 if (!x2apic_mode && !apic_phys)
1165 return;
1166
1167 maxlvt = lapic_get_maxlvt();
1168 /*
1169 * Masking an LVT entry can trigger a local APIC error
1170 * if the vector is zero. Mask LVTERR first to prevent this.
1171 */
1172 if (maxlvt >= 3) {
1173 v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
1174 apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
1175 }
1176 /*
1177 * Careful: we have to set masks only first to deassert
1178 * any level-triggered sources.
1179 */
1180 v = apic_read(APIC_LVTT);
1181 apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
1182 v = apic_read(APIC_LVT0);
1183 apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
1184 v = apic_read(APIC_LVT1);
1185 apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
1186 if (maxlvt >= 4) {
1187 v = apic_read(APIC_LVTPC);
1188 apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
1189 }
1190
1191 /* lets not touch this if we didn't frob it */
1192#ifdef CONFIG_X86_THERMAL_VECTOR
1193 if (maxlvt >= 5) {
1194 v = apic_read(APIC_LVTTHMR);
1195 apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
1196 }
1197#endif
1198#ifdef CONFIG_X86_MCE_INTEL
1199 if (maxlvt >= 6) {
1200 v = apic_read(APIC_LVTCMCI);
1201 if (!(v & APIC_LVT_MASKED))
1202 apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
1203 }
1204#endif
1205
1206 /*
1207 * Clean APIC state for other OSs:
1208 */
1209 apic_write(APIC_LVTT, APIC_LVT_MASKED);
1210 apic_write(APIC_LVT0, APIC_LVT_MASKED);
1211 apic_write(APIC_LVT1, APIC_LVT_MASKED);
1212 if (maxlvt >= 3)
1213 apic_write(APIC_LVTERR, APIC_LVT_MASKED);
1214 if (maxlvt >= 4)
1215 apic_write(APIC_LVTPC, APIC_LVT_MASKED);
1216
1217 /* Integrated APIC (!82489DX) ? */
1218 if (lapic_is_integrated()) {
1219 if (maxlvt > 3)
1220 /* Clear ESR due to Pentium errata 3AP and 11AP */
1221 apic_write(APIC_ESR, 0);
1222 apic_read(APIC_ESR);
1223 }
1224}
1225
1226/**
1227 * apic_soft_disable - Clears and software disables the local APIC on hotplug
1228 *
1229 * Contrary to disable_local_APIC() this does not touch the enable bit in
1230 * MSR_IA32_APICBASE. Clearing that bit on systems based on the 3 wire APIC
1231 * bus would require a hardware reset as the APIC would lose track of bus
1232 * arbitration. On systems with FSB delivery APICBASE could be disabled,
1233 * but it has to be guaranteed that no interrupt is sent to the APIC while
1234 * in that state and it's not clear from the SDM whether it still responds
1235 * to INIT/SIPI messages. Stay on the safe side and use software disable.
1236 */
1237void apic_soft_disable(void)
1238{
1239 u32 value;
1240
1241 clear_local_APIC();
1242
1243 /* Soft disable APIC (implies clearing of registers for 82489DX!). */
1244 value = apic_read(APIC_SPIV);
1245 value &= ~APIC_SPIV_APIC_ENABLED;
1246 apic_write(APIC_SPIV, value);
1247}
1248
1249/**
1250 * disable_local_APIC - clear and disable the local APIC
1251 */
1252void disable_local_APIC(void)
1253{
1254 /* APIC hasn't been mapped yet */
1255 if (!x2apic_mode && !apic_phys)
1256 return;
1257
1258 apic_soft_disable();
1259
1260#ifdef CONFIG_X86_32
1261 /*
1262 * When LAPIC was disabled by the BIOS and enabled by the kernel,
1263 * restore the disabled state.
1264 */
1265 if (enabled_via_apicbase) {
1266 unsigned int l, h;
1267
1268 rdmsr(MSR_IA32_APICBASE, l, h);
1269 l &= ~MSR_IA32_APICBASE_ENABLE;
1270 wrmsr(MSR_IA32_APICBASE, l, h);
1271 }
1272#endif
1273}
1274
1275/*
1276 * If Linux enabled the LAPIC against the BIOS default disable it down before
1277 * re-entering the BIOS on shutdown. Otherwise the BIOS may get confused and
1278 * not power-off. Additionally clear all LVT entries before disable_local_APIC
1279 * for the case where Linux didn't enable the LAPIC.
1280 */
1281void lapic_shutdown(void)
1282{
1283 unsigned long flags;
1284
1285 if (!boot_cpu_has(X86_FEATURE_APIC) && !apic_from_smp_config())
1286 return;
1287
1288 local_irq_save(flags);
1289
1290#ifdef CONFIG_X86_32
1291 if (!enabled_via_apicbase)
1292 clear_local_APIC();
1293 else
1294#endif
1295 disable_local_APIC();
1296
1297
1298 local_irq_restore(flags);
1299}
1300
1301/**
1302 * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1303 */
1304void __init sync_Arb_IDs(void)
1305{
1306 /*
1307 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1308 * needed on AMD.
1309 */
1310 if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1311 return;
1312
1313 /*
1314 * Wait for idle.
1315 */
1316 apic_wait_icr_idle();
1317
1318 apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1319 apic_write(APIC_ICR, APIC_DEST_ALLINC |
1320 APIC_INT_LEVELTRIG | APIC_DM_INIT);
1321}
1322
1323enum apic_intr_mode_id apic_intr_mode __ro_after_init;
1324
1325static int __init apic_intr_mode_select(void)
1326{
1327 /* Check kernel option */
1328 if (disable_apic) {
1329 pr_info("APIC disabled via kernel command line\n");
1330 return APIC_PIC;
1331 }
1332
1333 /* Check BIOS */
1334#ifdef CONFIG_X86_64
1335 /* On 64-bit, the APIC must be integrated, Check local APIC only */
1336 if (!boot_cpu_has(X86_FEATURE_APIC)) {
1337 disable_apic = 1;
1338 pr_info("APIC disabled by BIOS\n");
1339 return APIC_PIC;
1340 }
1341#else
1342 /* On 32-bit, the APIC may be integrated APIC or 82489DX */
1343
1344 /* Neither 82489DX nor integrated APIC ? */
1345 if (!boot_cpu_has(X86_FEATURE_APIC) && !smp_found_config) {
1346 disable_apic = 1;
1347 return APIC_PIC;
1348 }
1349
1350 /* If the BIOS pretends there is an integrated APIC ? */
1351 if (!boot_cpu_has(X86_FEATURE_APIC) &&
1352 APIC_INTEGRATED(boot_cpu_apic_version)) {
1353 disable_apic = 1;
1354 pr_err(FW_BUG "Local APIC %d not detected, force emulation\n",
1355 boot_cpu_physical_apicid);
1356 return APIC_PIC;
1357 }
1358#endif
1359
1360 /* Check MP table or ACPI MADT configuration */
1361 if (!smp_found_config) {
1362 disable_ioapic_support();
1363 if (!acpi_lapic) {
1364 pr_info("APIC: ACPI MADT or MP tables are not detected\n");
1365 return APIC_VIRTUAL_WIRE_NO_CONFIG;
1366 }
1367 return APIC_VIRTUAL_WIRE;
1368 }
1369
1370#ifdef CONFIG_SMP
1371 /* If SMP should be disabled, then really disable it! */
1372 if (!setup_max_cpus) {
1373 pr_info("APIC: SMP mode deactivated\n");
1374 return APIC_SYMMETRIC_IO_NO_ROUTING;
1375 }
1376
1377 if (read_apic_id() != boot_cpu_physical_apicid) {
1378 panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
1379 read_apic_id(), boot_cpu_physical_apicid);
1380 /* Or can we switch back to PIC here? */
1381 }
1382#endif
1383
1384 return APIC_SYMMETRIC_IO;
1385}
1386
1387/*
1388 * An initial setup of the virtual wire mode.
1389 */
1390void __init init_bsp_APIC(void)
1391{
1392 unsigned int value;
1393
1394 /*
1395 * Don't do the setup now if we have a SMP BIOS as the
1396 * through-I/O-APIC virtual wire mode might be active.
1397 */
1398 if (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC))
1399 return;
1400
1401 /*
1402 * Do not trust the local APIC being empty at bootup.
1403 */
1404 clear_local_APIC();
1405
1406 /*
1407 * Enable APIC.
1408 */
1409 value = apic_read(APIC_SPIV);
1410 value &= ~APIC_VECTOR_MASK;
1411 value |= APIC_SPIV_APIC_ENABLED;
1412
1413#ifdef CONFIG_X86_32
1414 /* This bit is reserved on P4/Xeon and should be cleared */
1415 if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1416 (boot_cpu_data.x86 == 15))
1417 value &= ~APIC_SPIV_FOCUS_DISABLED;
1418 else
1419#endif
1420 value |= APIC_SPIV_FOCUS_DISABLED;
1421 value |= SPURIOUS_APIC_VECTOR;
1422 apic_write(APIC_SPIV, value);
1423
1424 /*
1425 * Set up the virtual wire mode.
1426 */
1427 apic_write(APIC_LVT0, APIC_DM_EXTINT);
1428 value = APIC_DM_NMI;
1429 if (!lapic_is_integrated()) /* 82489DX */
1430 value |= APIC_LVT_LEVEL_TRIGGER;
1431 if (apic_extnmi == APIC_EXTNMI_NONE)
1432 value |= APIC_LVT_MASKED;
1433 apic_write(APIC_LVT1, value);
1434}
1435
1436static void __init apic_bsp_setup(bool upmode);
1437
1438/* Init the interrupt delivery mode for the BSP */
1439void __init apic_intr_mode_init(void)
1440{
1441 bool upmode = IS_ENABLED(CONFIG_UP_LATE_INIT);
1442
1443 apic_intr_mode = apic_intr_mode_select();
1444
1445 switch (apic_intr_mode) {
1446 case APIC_PIC:
1447 pr_info("APIC: Keep in PIC mode(8259)\n");
1448 return;
1449 case APIC_VIRTUAL_WIRE:
1450 pr_info("APIC: Switch to virtual wire mode setup\n");
1451 default_setup_apic_routing();
1452 break;
1453 case APIC_VIRTUAL_WIRE_NO_CONFIG:
1454 pr_info("APIC: Switch to virtual wire mode setup with no configuration\n");
1455 upmode = true;
1456 default_setup_apic_routing();
1457 break;
1458 case APIC_SYMMETRIC_IO:
1459 pr_info("APIC: Switch to symmetric I/O mode setup\n");
1460 default_setup_apic_routing();
1461 break;
1462 case APIC_SYMMETRIC_IO_NO_ROUTING:
1463 pr_info("APIC: Switch to symmetric I/O mode setup in no SMP routine\n");
1464 break;
1465 }
1466
1467 apic_bsp_setup(upmode);
1468}
1469
1470static void lapic_setup_esr(void)
1471{
1472 unsigned int oldvalue, value, maxlvt;
1473
1474 if (!lapic_is_integrated()) {
1475 pr_info("No ESR for 82489DX.\n");
1476 return;
1477 }
1478
1479 if (apic->disable_esr) {
1480 /*
1481 * Something untraceable is creating bad interrupts on
1482 * secondary quads ... for the moment, just leave the
1483 * ESR disabled - we can't do anything useful with the
1484 * errors anyway - mbligh
1485 */
1486 pr_info("Leaving ESR disabled.\n");
1487 return;
1488 }
1489
1490 maxlvt = lapic_get_maxlvt();
1491 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
1492 apic_write(APIC_ESR, 0);
1493 oldvalue = apic_read(APIC_ESR);
1494
1495 /* enables sending errors */
1496 value = ERROR_APIC_VECTOR;
1497 apic_write(APIC_LVTERR, value);
1498
1499 /*
1500 * spec says clear errors after enabling vector.
1501 */
1502 if (maxlvt > 3)
1503 apic_write(APIC_ESR, 0);
1504 value = apic_read(APIC_ESR);
1505 if (value != oldvalue)
1506 apic_printk(APIC_VERBOSE, "ESR value before enabling "
1507 "vector: 0x%08x after: 0x%08x\n",
1508 oldvalue, value);
1509}
1510
1511#define APIC_IR_REGS APIC_ISR_NR
1512#define APIC_IR_BITS (APIC_IR_REGS * 32)
1513#define APIC_IR_MAPSIZE (APIC_IR_BITS / BITS_PER_LONG)
1514
1515union apic_ir {
1516 unsigned long map[APIC_IR_MAPSIZE];
1517 u32 regs[APIC_IR_REGS];
1518};
1519
1520static bool apic_check_and_ack(union apic_ir *irr, union apic_ir *isr)
1521{
1522 int i, bit;
1523
1524 /* Read the IRRs */
1525 for (i = 0; i < APIC_IR_REGS; i++)
1526 irr->regs[i] = apic_read(APIC_IRR + i * 0x10);
1527
1528 /* Read the ISRs */
1529 for (i = 0; i < APIC_IR_REGS; i++)
1530 isr->regs[i] = apic_read(APIC_ISR + i * 0x10);
1531
1532 /*
1533 * If the ISR map is not empty. ACK the APIC and run another round
1534 * to verify whether a pending IRR has been unblocked and turned
1535 * into a ISR.
1536 */
1537 if (!bitmap_empty(isr->map, APIC_IR_BITS)) {
1538 /*
1539 * There can be multiple ISR bits set when a high priority
1540 * interrupt preempted a lower priority one. Issue an ACK
1541 * per set bit.
1542 */
1543 for_each_set_bit(bit, isr->map, APIC_IR_BITS)
1544 ack_APIC_irq();
1545 return true;
1546 }
1547
1548 return !bitmap_empty(irr->map, APIC_IR_BITS);
1549}
1550
1551/*
1552 * After a crash, we no longer service the interrupts and a pending
1553 * interrupt from previous kernel might still have ISR bit set.
1554 *
1555 * Most probably by now the CPU has serviced that pending interrupt and it
1556 * might not have done the ack_APIC_irq() because it thought, interrupt
1557 * came from i8259 as ExtInt. LAPIC did not get EOI so it does not clear
1558 * the ISR bit and cpu thinks it has already serivced the interrupt. Hence
1559 * a vector might get locked. It was noticed for timer irq (vector
1560 * 0x31). Issue an extra EOI to clear ISR.
1561 *
1562 * If there are pending IRR bits they turn into ISR bits after a higher
1563 * priority ISR bit has been acked.
1564 */
1565static void apic_pending_intr_clear(void)
1566{
1567 union apic_ir irr, isr;
1568 unsigned int i;
1569
1570 /* 512 loops are way oversized and give the APIC a chance to obey. */
1571 for (i = 0; i < 512; i++) {
1572 if (!apic_check_and_ack(&irr, &isr))
1573 return;
1574 }
1575 /* Dump the IRR/ISR content if that failed */
1576 pr_warn("APIC: Stale IRR: %256pb ISR: %256pb\n", irr.map, isr.map);
1577}
1578
1579/**
1580 * setup_local_APIC - setup the local APIC
1581 *
1582 * Used to setup local APIC while initializing BSP or bringing up APs.
1583 * Always called with preemption disabled.
1584 */
1585static void setup_local_APIC(void)
1586{
1587 int cpu = smp_processor_id();
1588 unsigned int value;
1589
1590 if (disable_apic) {
1591 disable_ioapic_support();
1592 return;
1593 }
1594
1595 /*
1596 * If this comes from kexec/kcrash the APIC might be enabled in
1597 * SPIV. Soft disable it before doing further initialization.
1598 */
1599 value = apic_read(APIC_SPIV);
1600 value &= ~APIC_SPIV_APIC_ENABLED;
1601 apic_write(APIC_SPIV, value);
1602
1603#ifdef CONFIG_X86_32
1604 /* Pound the ESR really hard over the head with a big hammer - mbligh */
1605 if (lapic_is_integrated() && apic->disable_esr) {
1606 apic_write(APIC_ESR, 0);
1607 apic_write(APIC_ESR, 0);
1608 apic_write(APIC_ESR, 0);
1609 apic_write(APIC_ESR, 0);
1610 }
1611#endif
1612 /*
1613 * Double-check whether this APIC is really registered.
1614 * This is meaningless in clustered apic mode, so we skip it.
1615 */
1616 BUG_ON(!apic->apic_id_registered());
1617
1618 /*
1619 * Intel recommends to set DFR, LDR and TPR before enabling
1620 * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
1621 * document number 292116). So here it goes...
1622 */
1623 apic->init_apic_ldr();
1624
1625#ifdef CONFIG_X86_32
1626 if (apic->dest_logical) {
1627 int logical_apicid, ldr_apicid;
1628
1629 /*
1630 * APIC LDR is initialized. If logical_apicid mapping was
1631 * initialized during get_smp_config(), make sure it matches
1632 * the actual value.
1633 */
1634 logical_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
1635 ldr_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
1636 if (logical_apicid != BAD_APICID)
1637 WARN_ON(logical_apicid != ldr_apicid);
1638 /* Always use the value from LDR. */
1639 early_per_cpu(x86_cpu_to_logical_apicid, cpu) = ldr_apicid;
1640 }
1641#endif
1642
1643 /*
1644 * Set Task Priority to 'accept all except vectors 0-31'. An APIC
1645 * vector in the 16-31 range could be delivered if TPR == 0, but we
1646 * would think it's an exception and terrible things will happen. We
1647 * never change this later on.
1648 */
1649 value = apic_read(APIC_TASKPRI);
1650 value &= ~APIC_TPRI_MASK;
1651 value |= 0x10;
1652 apic_write(APIC_TASKPRI, value);
1653
1654 /* Clear eventually stale ISR/IRR bits */
1655 apic_pending_intr_clear();
1656
1657 /*
1658 * Now that we are all set up, enable the APIC
1659 */
1660 value = apic_read(APIC_SPIV);
1661 value &= ~APIC_VECTOR_MASK;
1662 /*
1663 * Enable APIC
1664 */
1665 value |= APIC_SPIV_APIC_ENABLED;
1666
1667#ifdef CONFIG_X86_32
1668 /*
1669 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1670 * certain networking cards. If high frequency interrupts are
1671 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1672 * entry is masked/unmasked at a high rate as well then sooner or
1673 * later IOAPIC line gets 'stuck', no more interrupts are received
1674 * from the device. If focus CPU is disabled then the hang goes
1675 * away, oh well :-(
1676 *
1677 * [ This bug can be reproduced easily with a level-triggered
1678 * PCI Ne2000 networking cards and PII/PIII processors, dual
1679 * BX chipset. ]
1680 */
1681 /*
1682 * Actually disabling the focus CPU check just makes the hang less
1683 * frequent as it makes the interrupt distributon model be more
1684 * like LRU than MRU (the short-term load is more even across CPUs).
1685 */
1686
1687 /*
1688 * - enable focus processor (bit==0)
1689 * - 64bit mode always use processor focus
1690 * so no need to set it
1691 */
1692 value &= ~APIC_SPIV_FOCUS_DISABLED;
1693#endif
1694
1695 /*
1696 * Set spurious IRQ vector
1697 */
1698 value |= SPURIOUS_APIC_VECTOR;
1699 apic_write(APIC_SPIV, value);
1700
1701 perf_events_lapic_init();
1702
1703 /*
1704 * Set up LVT0, LVT1:
1705 *
1706 * set up through-local-APIC on the boot CPU's LINT0. This is not
1707 * strictly necessary in pure symmetric-IO mode, but sometimes
1708 * we delegate interrupts to the 8259A.
1709 */
1710 /*
1711 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1712 */
1713 value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1714 if (!cpu && (pic_mode || !value || skip_ioapic_setup)) {
1715 value = APIC_DM_EXTINT;
1716 apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
1717 } else {
1718 value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1719 apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
1720 }
1721 apic_write(APIC_LVT0, value);
1722
1723 /*
1724 * Only the BSP sees the LINT1 NMI signal by default. This can be
1725 * modified by apic_extnmi= boot option.
1726 */
1727 if ((!cpu && apic_extnmi != APIC_EXTNMI_NONE) ||
1728 apic_extnmi == APIC_EXTNMI_ALL)
1729 value = APIC_DM_NMI;
1730 else
1731 value = APIC_DM_NMI | APIC_LVT_MASKED;
1732
1733 /* Is 82489DX ? */
1734 if (!lapic_is_integrated())
1735 value |= APIC_LVT_LEVEL_TRIGGER;
1736 apic_write(APIC_LVT1, value);
1737
1738#ifdef CONFIG_X86_MCE_INTEL
1739 /* Recheck CMCI information after local APIC is up on CPU #0 */
1740 if (!cpu)
1741 cmci_recheck();
1742#endif
1743}
1744
1745static void end_local_APIC_setup(void)
1746{
1747 lapic_setup_esr();
1748
1749#ifdef CONFIG_X86_32
1750 {
1751 unsigned int value;
1752 /* Disable the local apic timer */
1753 value = apic_read(APIC_LVTT);
1754 value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1755 apic_write(APIC_LVTT, value);
1756 }
1757#endif
1758
1759 apic_pm_activate();
1760}
1761
1762/*
1763 * APIC setup function for application processors. Called from smpboot.c
1764 */
1765void apic_ap_setup(void)
1766{
1767 setup_local_APIC();
1768 end_local_APIC_setup();
1769}
1770
1771#ifdef CONFIG_X86_X2APIC
1772int x2apic_mode;
1773
1774enum {
1775 X2APIC_OFF,
1776 X2APIC_ON,
1777 X2APIC_DISABLED,
1778};
1779static int x2apic_state;
1780
1781static void __x2apic_disable(void)
1782{
1783 u64 msr;
1784
1785 if (!boot_cpu_has(X86_FEATURE_APIC))
1786 return;
1787
1788 rdmsrl(MSR_IA32_APICBASE, msr);
1789 if (!(msr & X2APIC_ENABLE))
1790 return;
1791 /* Disable xapic and x2apic first and then reenable xapic mode */
1792 wrmsrl(MSR_IA32_APICBASE, msr & ~(X2APIC_ENABLE | XAPIC_ENABLE));
1793 wrmsrl(MSR_IA32_APICBASE, msr & ~X2APIC_ENABLE);
1794 printk_once(KERN_INFO "x2apic disabled\n");
1795}
1796
1797static void __x2apic_enable(void)
1798{
1799 u64 msr;
1800
1801 rdmsrl(MSR_IA32_APICBASE, msr);
1802 if (msr & X2APIC_ENABLE)
1803 return;
1804 wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE);
1805 printk_once(KERN_INFO "x2apic enabled\n");
1806}
1807
1808static int __init setup_nox2apic(char *str)
1809{
1810 if (x2apic_enabled()) {
1811 int apicid = native_apic_msr_read(APIC_ID);
1812
1813 if (apicid >= 255) {
1814 pr_warning("Apicid: %08x, cannot enforce nox2apic\n",
1815 apicid);
1816 return 0;
1817 }
1818 pr_warning("x2apic already enabled.\n");
1819 __x2apic_disable();
1820 }
1821 setup_clear_cpu_cap(X86_FEATURE_X2APIC);
1822 x2apic_state = X2APIC_DISABLED;
1823 x2apic_mode = 0;
1824 return 0;
1825}
1826early_param("nox2apic", setup_nox2apic);
1827
1828/* Called from cpu_init() to enable x2apic on (secondary) cpus */
1829void x2apic_setup(void)
1830{
1831 /*
1832 * If x2apic is not in ON state, disable it if already enabled
1833 * from BIOS.
1834 */
1835 if (x2apic_state != X2APIC_ON) {
1836 __x2apic_disable();
1837 return;
1838 }
1839 __x2apic_enable();
1840}
1841
1842static __init void x2apic_disable(void)
1843{
1844 u32 x2apic_id, state = x2apic_state;
1845
1846 x2apic_mode = 0;
1847 x2apic_state = X2APIC_DISABLED;
1848
1849 if (state != X2APIC_ON)
1850 return;
1851
1852 x2apic_id = read_apic_id();
1853 if (x2apic_id >= 255)
1854 panic("Cannot disable x2apic, id: %08x\n", x2apic_id);
1855
1856 __x2apic_disable();
1857 register_lapic_address(mp_lapic_addr);
1858}
1859
1860static __init void x2apic_enable(void)
1861{
1862 if (x2apic_state != X2APIC_OFF)
1863 return;
1864
1865 x2apic_mode = 1;
1866 x2apic_state = X2APIC_ON;
1867 __x2apic_enable();
1868}
1869
1870static __init void try_to_enable_x2apic(int remap_mode)
1871{
1872 if (x2apic_state == X2APIC_DISABLED)
1873 return;
1874
1875 if (remap_mode != IRQ_REMAP_X2APIC_MODE) {
1876 /* IR is required if there is APIC ID > 255 even when running
1877 * under KVM
1878 */
1879 if (max_physical_apicid > 255 ||
1880 !x86_init.hyper.x2apic_available()) {
1881 pr_info("x2apic: IRQ remapping doesn't support X2APIC mode\n");
1882 x2apic_disable();
1883 return;
1884 }
1885
1886 /*
1887 * without IR all CPUs can be addressed by IOAPIC/MSI
1888 * only in physical mode
1889 */
1890 x2apic_phys = 1;
1891 }
1892 x2apic_enable();
1893}
1894
1895void __init check_x2apic(void)
1896{
1897 if (x2apic_enabled()) {
1898 pr_info("x2apic: enabled by BIOS, switching to x2apic ops\n");
1899 x2apic_mode = 1;
1900 x2apic_state = X2APIC_ON;
1901 } else if (!boot_cpu_has(X86_FEATURE_X2APIC)) {
1902 x2apic_state = X2APIC_DISABLED;
1903 }
1904}
1905#else /* CONFIG_X86_X2APIC */
1906static int __init validate_x2apic(void)
1907{
1908 if (!apic_is_x2apic_enabled())
1909 return 0;
1910 /*
1911 * Checkme: Can we simply turn off x2apic here instead of panic?
1912 */
1913 panic("BIOS has enabled x2apic but kernel doesn't support x2apic, please disable x2apic in BIOS.\n");
1914}
1915early_initcall(validate_x2apic);
1916
1917static inline void try_to_enable_x2apic(int remap_mode) { }
1918static inline void __x2apic_enable(void) { }
1919#endif /* !CONFIG_X86_X2APIC */
1920
1921void __init enable_IR_x2apic(void)
1922{
1923 unsigned long flags;
1924 int ret, ir_stat;
1925
1926 if (skip_ioapic_setup) {
1927 pr_info("Not enabling interrupt remapping due to skipped IO-APIC setup\n");
1928 return;
1929 }
1930
1931 ir_stat = irq_remapping_prepare();
1932 if (ir_stat < 0 && !x2apic_supported())
1933 return;
1934
1935 ret = save_ioapic_entries();
1936 if (ret) {
1937 pr_info("Saving IO-APIC state failed: %d\n", ret);
1938 return;
1939 }
1940
1941 local_irq_save(flags);
1942 legacy_pic->mask_all();
1943 mask_ioapic_entries();
1944
1945 /* If irq_remapping_prepare() succeeded, try to enable it */
1946 if (ir_stat >= 0)
1947 ir_stat = irq_remapping_enable();
1948 /* ir_stat contains the remap mode or an error code */
1949 try_to_enable_x2apic(ir_stat);
1950
1951 if (ir_stat < 0)
1952 restore_ioapic_entries();
1953 legacy_pic->restore_mask();
1954 local_irq_restore(flags);
1955}
1956
1957#ifdef CONFIG_X86_64
1958/*
1959 * Detect and enable local APICs on non-SMP boards.
1960 * Original code written by Keir Fraser.
1961 * On AMD64 we trust the BIOS - if it says no APIC it is likely
1962 * not correctly set up (usually the APIC timer won't work etc.)
1963 */
1964static int __init detect_init_APIC(void)
1965{
1966 if (!boot_cpu_has(X86_FEATURE_APIC)) {
1967 pr_info("No local APIC present\n");
1968 return -1;
1969 }
1970
1971 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1972 return 0;
1973}
1974#else
1975
1976static int __init apic_verify(void)
1977{
1978 u32 features, h, l;
1979
1980 /*
1981 * The APIC feature bit should now be enabled
1982 * in `cpuid'
1983 */
1984 features = cpuid_edx(1);
1985 if (!(features & (1 << X86_FEATURE_APIC))) {
1986 pr_warning("Could not enable APIC!\n");
1987 return -1;
1988 }
1989 set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1990 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1991
1992 /* The BIOS may have set up the APIC at some other address */
1993 if (boot_cpu_data.x86 >= 6) {
1994 rdmsr(MSR_IA32_APICBASE, l, h);
1995 if (l & MSR_IA32_APICBASE_ENABLE)
1996 mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1997 }
1998
1999 pr_info("Found and enabled local APIC!\n");
2000 return 0;
2001}
2002
2003int __init apic_force_enable(unsigned long addr)
2004{
2005 u32 h, l;
2006
2007 if (disable_apic)
2008 return -1;
2009
2010 /*
2011 * Some BIOSes disable the local APIC in the APIC_BASE
2012 * MSR. This can only be done in software for Intel P6 or later
2013 * and AMD K7 (Model > 1) or later.
2014 */
2015 if (boot_cpu_data.x86 >= 6) {
2016 rdmsr(MSR_IA32_APICBASE, l, h);
2017 if (!(l & MSR_IA32_APICBASE_ENABLE)) {
2018 pr_info("Local APIC disabled by BIOS -- reenabling.\n");
2019 l &= ~MSR_IA32_APICBASE_BASE;
2020 l |= MSR_IA32_APICBASE_ENABLE | addr;
2021 wrmsr(MSR_IA32_APICBASE, l, h);
2022 enabled_via_apicbase = 1;
2023 }
2024 }
2025 return apic_verify();
2026}
2027
2028/*
2029 * Detect and initialize APIC
2030 */
2031static int __init detect_init_APIC(void)
2032{
2033 /* Disabled by kernel option? */
2034 if (disable_apic)
2035 return -1;
2036
2037 switch (boot_cpu_data.x86_vendor) {
2038 case X86_VENDOR_AMD:
2039 if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
2040 (boot_cpu_data.x86 >= 15))
2041 break;
2042 goto no_apic;
2043 case X86_VENDOR_HYGON:
2044 break;
2045 case X86_VENDOR_INTEL:
2046 if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
2047 (boot_cpu_data.x86 == 5 && boot_cpu_has(X86_FEATURE_APIC)))
2048 break;
2049 goto no_apic;
2050 default:
2051 goto no_apic;
2052 }
2053
2054 if (!boot_cpu_has(X86_FEATURE_APIC)) {
2055 /*
2056 * Over-ride BIOS and try to enable the local APIC only if
2057 * "lapic" specified.
2058 */
2059 if (!force_enable_local_apic) {
2060 pr_info("Local APIC disabled by BIOS -- "
2061 "you can enable it with \"lapic\"\n");
2062 return -1;
2063 }
2064 if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
2065 return -1;
2066 } else {
2067 if (apic_verify())
2068 return -1;
2069 }
2070
2071 apic_pm_activate();
2072
2073 return 0;
2074
2075no_apic:
2076 pr_info("No local APIC present or hardware disabled\n");
2077 return -1;
2078}
2079#endif
2080
2081/**
2082 * init_apic_mappings - initialize APIC mappings
2083 */
2084void __init init_apic_mappings(void)
2085{
2086 unsigned int new_apicid;
2087
2088 apic_check_deadline_errata();
2089
2090 if (x2apic_mode) {
2091 boot_cpu_physical_apicid = read_apic_id();
2092 return;
2093 }
2094
2095 /* If no local APIC can be found return early */
2096 if (!smp_found_config && detect_init_APIC()) {
2097 /* lets NOP'ify apic operations */
2098 pr_info("APIC: disable apic facility\n");
2099 apic_disable();
2100 } else {
2101 apic_phys = mp_lapic_addr;
2102
2103 /*
2104 * If the system has ACPI MADT tables or MP info, the LAPIC
2105 * address is already registered.
2106 */
2107 if (!acpi_lapic && !smp_found_config)
2108 register_lapic_address(apic_phys);
2109 }
2110
2111 /*
2112 * Fetch the APIC ID of the BSP in case we have a
2113 * default configuration (or the MP table is broken).
2114 */
2115 new_apicid = read_apic_id();
2116 if (boot_cpu_physical_apicid != new_apicid) {
2117 boot_cpu_physical_apicid = new_apicid;
2118 /*
2119 * yeah -- we lie about apic_version
2120 * in case if apic was disabled via boot option
2121 * but it's not a problem for SMP compiled kernel
2122 * since apic_intr_mode_select is prepared for such
2123 * a case and disable smp mode
2124 */
2125 boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
2126 }
2127}
2128
2129void __init register_lapic_address(unsigned long address)
2130{
2131 mp_lapic_addr = address;
2132
2133 if (!x2apic_mode) {
2134 set_fixmap_nocache(FIX_APIC_BASE, address);
2135 apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
2136 APIC_BASE, address);
2137 }
2138 if (boot_cpu_physical_apicid == -1U) {
2139 boot_cpu_physical_apicid = read_apic_id();
2140 boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
2141 }
2142}
2143
2144/*
2145 * Local APIC interrupts
2146 */
2147
2148/*
2149 * This interrupt should _never_ happen with our APIC/SMP architecture
2150 */
2151__visible void __irq_entry smp_spurious_interrupt(struct pt_regs *regs)
2152{
2153 u8 vector = ~regs->orig_ax;
2154 u32 v;
2155
2156 entering_irq();
2157 trace_spurious_apic_entry(vector);
2158
2159 inc_irq_stat(irq_spurious_count);
2160
2161 /*
2162 * If this is a spurious interrupt then do not acknowledge
2163 */
2164 if (vector == SPURIOUS_APIC_VECTOR) {
2165 /* See SDM vol 3 */
2166 pr_info("Spurious APIC interrupt (vector 0xFF) on CPU#%d, should never happen.\n",
2167 smp_processor_id());
2168 goto out;
2169 }
2170
2171 /*
2172 * If it is a vectored one, verify it's set in the ISR. If set,
2173 * acknowledge it.
2174 */
2175 v = apic_read(APIC_ISR + ((vector & ~0x1f) >> 1));
2176 if (v & (1 << (vector & 0x1f))) {
2177 pr_info("Spurious interrupt (vector 0x%02x) on CPU#%d. Acked\n",
2178 vector, smp_processor_id());
2179 ack_APIC_irq();
2180 } else {
2181 pr_info("Spurious interrupt (vector 0x%02x) on CPU#%d. Not pending!\n",
2182 vector, smp_processor_id());
2183 }
2184out:
2185 trace_spurious_apic_exit(vector);
2186 exiting_irq();
2187}
2188
2189/*
2190 * This interrupt should never happen with our APIC/SMP architecture
2191 */
2192__visible void __irq_entry smp_error_interrupt(struct pt_regs *regs)
2193{
2194 static const char * const error_interrupt_reason[] = {
2195 "Send CS error", /* APIC Error Bit 0 */
2196 "Receive CS error", /* APIC Error Bit 1 */
2197 "Send accept error", /* APIC Error Bit 2 */
2198 "Receive accept error", /* APIC Error Bit 3 */
2199 "Redirectable IPI", /* APIC Error Bit 4 */
2200 "Send illegal vector", /* APIC Error Bit 5 */
2201 "Received illegal vector", /* APIC Error Bit 6 */
2202 "Illegal register address", /* APIC Error Bit 7 */
2203 };
2204 u32 v, i = 0;
2205
2206 entering_irq();
2207 trace_error_apic_entry(ERROR_APIC_VECTOR);
2208
2209 /* First tickle the hardware, only then report what went on. -- REW */
2210 if (lapic_get_maxlvt() > 3) /* Due to the Pentium erratum 3AP. */
2211 apic_write(APIC_ESR, 0);
2212 v = apic_read(APIC_ESR);
2213 ack_APIC_irq();
2214 atomic_inc(&irq_err_count);
2215
2216 apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x",
2217 smp_processor_id(), v);
2218
2219 v &= 0xff;
2220 while (v) {
2221 if (v & 0x1)
2222 apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
2223 i++;
2224 v >>= 1;
2225 }
2226
2227 apic_printk(APIC_DEBUG, KERN_CONT "\n");
2228
2229 trace_error_apic_exit(ERROR_APIC_VECTOR);
2230 exiting_irq();
2231}
2232
2233/**
2234 * connect_bsp_APIC - attach the APIC to the interrupt system
2235 */
2236static void __init connect_bsp_APIC(void)
2237{
2238#ifdef CONFIG_X86_32
2239 if (pic_mode) {
2240 /*
2241 * Do not trust the local APIC being empty at bootup.
2242 */
2243 clear_local_APIC();
2244 /*
2245 * PIC mode, enable APIC mode in the IMCR, i.e. connect BSP's
2246 * local APIC to INT and NMI lines.
2247 */
2248 apic_printk(APIC_VERBOSE, "leaving PIC mode, "
2249 "enabling APIC mode.\n");
2250 imcr_pic_to_apic();
2251 }
2252#endif
2253}
2254
2255/**
2256 * disconnect_bsp_APIC - detach the APIC from the interrupt system
2257 * @virt_wire_setup: indicates, whether virtual wire mode is selected
2258 *
2259 * Virtual wire mode is necessary to deliver legacy interrupts even when the
2260 * APIC is disabled.
2261 */
2262void disconnect_bsp_APIC(int virt_wire_setup)
2263{
2264 unsigned int value;
2265
2266#ifdef CONFIG_X86_32
2267 if (pic_mode) {
2268 /*
2269 * Put the board back into PIC mode (has an effect only on
2270 * certain older boards). Note that APIC interrupts, including
2271 * IPIs, won't work beyond this point! The only exception are
2272 * INIT IPIs.
2273 */
2274 apic_printk(APIC_VERBOSE, "disabling APIC mode, "
2275 "entering PIC mode.\n");
2276 imcr_apic_to_pic();
2277 return;
2278 }
2279#endif
2280
2281 /* Go back to Virtual Wire compatibility mode */
2282
2283 /* For the spurious interrupt use vector F, and enable it */
2284 value = apic_read(APIC_SPIV);
2285 value &= ~APIC_VECTOR_MASK;
2286 value |= APIC_SPIV_APIC_ENABLED;
2287 value |= 0xf;
2288 apic_write(APIC_SPIV, value);
2289
2290 if (!virt_wire_setup) {
2291 /*
2292 * For LVT0 make it edge triggered, active high,
2293 * external and enabled
2294 */
2295 value = apic_read(APIC_LVT0);
2296 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2297 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2298 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2299 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2300 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
2301 apic_write(APIC_LVT0, value);
2302 } else {
2303 /* Disable LVT0 */
2304 apic_write(APIC_LVT0, APIC_LVT_MASKED);
2305 }
2306
2307 /*
2308 * For LVT1 make it edge triggered, active high,
2309 * nmi and enabled
2310 */
2311 value = apic_read(APIC_LVT1);
2312 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2313 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2314 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2315 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2316 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
2317 apic_write(APIC_LVT1, value);
2318}
2319
2320/*
2321 * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
2322 * contiguously, it equals to current allocated max logical CPU ID plus 1.
2323 * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
2324 * so the maximum of nr_logical_cpuids is nr_cpu_ids.
2325 *
2326 * NOTE: Reserve 0 for BSP.
2327 */
2328static int nr_logical_cpuids = 1;
2329
2330/*
2331 * Used to store mapping between logical CPU IDs and APIC IDs.
2332 */
2333static int cpuid_to_apicid[] = {
2334 [0 ... NR_CPUS - 1] = -1,
2335};
2336
2337#ifdef CONFIG_SMP
2338/**
2339 * apic_id_is_primary_thread - Check whether APIC ID belongs to a primary thread
2340 * @id: APIC ID to check
2341 */
2342bool apic_id_is_primary_thread(unsigned int apicid)
2343{
2344 u32 mask;
2345
2346 if (smp_num_siblings == 1)
2347 return true;
2348 /* Isolate the SMT bit(s) in the APICID and check for 0 */
2349 mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
2350 return !(apicid & mask);
2351}
2352#endif
2353
2354/*
2355 * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
2356 * and cpuid_to_apicid[] synchronized.
2357 */
2358static int allocate_logical_cpuid(int apicid)
2359{
2360 int i;
2361
2362 /*
2363 * cpuid <-> apicid mapping is persistent, so when a cpu is up,
2364 * check if the kernel has allocated a cpuid for it.
2365 */
2366 for (i = 0; i < nr_logical_cpuids; i++) {
2367 if (cpuid_to_apicid[i] == apicid)
2368 return i;
2369 }
2370
2371 /* Allocate a new cpuid. */
2372 if (nr_logical_cpuids >= nr_cpu_ids) {
2373 WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
2374 "Processor %d/0x%x and the rest are ignored.\n",
2375 nr_cpu_ids, nr_logical_cpuids, apicid);
2376 return -EINVAL;
2377 }
2378
2379 cpuid_to_apicid[nr_logical_cpuids] = apicid;
2380 return nr_logical_cpuids++;
2381}
2382
2383int generic_processor_info(int apicid, int version)
2384{
2385 int cpu, max = nr_cpu_ids;
2386 bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
2387 phys_cpu_present_map);
2388
2389 /*
2390 * boot_cpu_physical_apicid is designed to have the apicid
2391 * returned by read_apic_id(), i.e, the apicid of the
2392 * currently booting-up processor. However, on some platforms,
2393 * it is temporarily modified by the apicid reported as BSP
2394 * through MP table. Concretely:
2395 *
2396 * - arch/x86/kernel/mpparse.c: MP_processor_info()
2397 * - arch/x86/mm/amdtopology.c: amd_numa_init()
2398 *
2399 * This function is executed with the modified
2400 * boot_cpu_physical_apicid. So, disabled_cpu_apicid kernel
2401 * parameter doesn't work to disable APs on kdump 2nd kernel.
2402 *
2403 * Since fixing handling of boot_cpu_physical_apicid requires
2404 * another discussion and tests on each platform, we leave it
2405 * for now and here we use read_apic_id() directly in this
2406 * function, generic_processor_info().
2407 */
2408 if (disabled_cpu_apicid != BAD_APICID &&
2409 disabled_cpu_apicid != read_apic_id() &&
2410 disabled_cpu_apicid == apicid) {
2411 int thiscpu = num_processors + disabled_cpus;
2412
2413 pr_warning("APIC: Disabling requested cpu."
2414 " Processor %d/0x%x ignored.\n",
2415 thiscpu, apicid);
2416
2417 disabled_cpus++;
2418 return -ENODEV;
2419 }
2420
2421 /*
2422 * If boot cpu has not been detected yet, then only allow upto
2423 * nr_cpu_ids - 1 processors and keep one slot free for boot cpu
2424 */
2425 if (!boot_cpu_detected && num_processors >= nr_cpu_ids - 1 &&
2426 apicid != boot_cpu_physical_apicid) {
2427 int thiscpu = max + disabled_cpus - 1;
2428
2429 pr_warning(
2430 "APIC: NR_CPUS/possible_cpus limit of %i almost"
2431 " reached. Keeping one slot for boot cpu."
2432 " Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
2433
2434 disabled_cpus++;
2435 return -ENODEV;
2436 }
2437
2438 if (num_processors >= nr_cpu_ids) {
2439 int thiscpu = max + disabled_cpus;
2440
2441 pr_warning("APIC: NR_CPUS/possible_cpus limit of %i "
2442 "reached. Processor %d/0x%x ignored.\n",
2443 max, thiscpu, apicid);
2444
2445 disabled_cpus++;
2446 return -EINVAL;
2447 }
2448
2449 if (apicid == boot_cpu_physical_apicid) {
2450 /*
2451 * x86_bios_cpu_apicid is required to have processors listed
2452 * in same order as logical cpu numbers. Hence the first
2453 * entry is BSP, and so on.
2454 * boot_cpu_init() already hold bit 0 in cpu_present_mask
2455 * for BSP.
2456 */
2457 cpu = 0;
2458
2459 /* Logical cpuid 0 is reserved for BSP. */
2460 cpuid_to_apicid[0] = apicid;
2461 } else {
2462 cpu = allocate_logical_cpuid(apicid);
2463 if (cpu < 0) {
2464 disabled_cpus++;
2465 return -EINVAL;
2466 }
2467 }
2468
2469 /*
2470 * Validate version
2471 */
2472 if (version == 0x0) {
2473 pr_warning("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
2474 cpu, apicid);
2475 version = 0x10;
2476 }
2477
2478 if (version != boot_cpu_apic_version) {
2479 pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
2480 boot_cpu_apic_version, cpu, version);
2481 }
2482
2483 if (apicid > max_physical_apicid)
2484 max_physical_apicid = apicid;
2485
2486#if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
2487 early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
2488 early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
2489#endif
2490#ifdef CONFIG_X86_32
2491 early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
2492 apic->x86_32_early_logical_apicid(cpu);
2493#endif
2494 set_cpu_possible(cpu, true);
2495 physid_set(apicid, phys_cpu_present_map);
2496 set_cpu_present(cpu, true);
2497 num_processors++;
2498
2499 return cpu;
2500}
2501
2502int hard_smp_processor_id(void)
2503{
2504 return read_apic_id();
2505}
2506
2507/*
2508 * Override the generic EOI implementation with an optimized version.
2509 * Only called during early boot when only one CPU is active and with
2510 * interrupts disabled, so we know this does not race with actual APIC driver
2511 * use.
2512 */
2513void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v))
2514{
2515 struct apic **drv;
2516
2517 for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
2518 /* Should happen once for each apic */
2519 WARN_ON((*drv)->eoi_write == eoi_write);
2520 (*drv)->native_eoi_write = (*drv)->eoi_write;
2521 (*drv)->eoi_write = eoi_write;
2522 }
2523}
2524
2525static void __init apic_bsp_up_setup(void)
2526{
2527#ifdef CONFIG_X86_64
2528 apic_write(APIC_ID, apic->set_apic_id(boot_cpu_physical_apicid));
2529#else
2530 /*
2531 * Hack: In case of kdump, after a crash, kernel might be booting
2532 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
2533 * might be zero if read from MP tables. Get it from LAPIC.
2534 */
2535# ifdef CONFIG_CRASH_DUMP
2536 boot_cpu_physical_apicid = read_apic_id();
2537# endif
2538#endif
2539 physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
2540}
2541
2542/**
2543 * apic_bsp_setup - Setup function for local apic and io-apic
2544 * @upmode: Force UP mode (for APIC_init_uniprocessor)
2545 */
2546static void __init apic_bsp_setup(bool upmode)
2547{
2548 connect_bsp_APIC();
2549 if (upmode)
2550 apic_bsp_up_setup();
2551 setup_local_APIC();
2552
2553 enable_IO_APIC();
2554 end_local_APIC_setup();
2555 irq_remap_enable_fault_handling();
2556 setup_IO_APIC();
2557}
2558
2559#ifdef CONFIG_UP_LATE_INIT
2560void __init up_late_init(void)
2561{
2562 if (apic_intr_mode == APIC_PIC)
2563 return;
2564
2565 /* Setup local timer */
2566 x86_init.timers.setup_percpu_clockev();
2567}
2568#endif
2569
2570/*
2571 * Power management
2572 */
2573#ifdef CONFIG_PM
2574
2575static struct {
2576 /*
2577 * 'active' is true if the local APIC was enabled by us and
2578 * not the BIOS; this signifies that we are also responsible
2579 * for disabling it before entering apm/acpi suspend
2580 */
2581 int active;
2582 /* r/w apic fields */
2583 unsigned int apic_id;
2584 unsigned int apic_taskpri;
2585 unsigned int apic_ldr;
2586 unsigned int apic_dfr;
2587 unsigned int apic_spiv;
2588 unsigned int apic_lvtt;
2589 unsigned int apic_lvtpc;
2590 unsigned int apic_lvt0;
2591 unsigned int apic_lvt1;
2592 unsigned int apic_lvterr;
2593 unsigned int apic_tmict;
2594 unsigned int apic_tdcr;
2595 unsigned int apic_thmr;
2596 unsigned int apic_cmci;
2597} apic_pm_state;
2598
2599static int lapic_suspend(void)
2600{
2601 unsigned long flags;
2602 int maxlvt;
2603
2604 if (!apic_pm_state.active)
2605 return 0;
2606
2607 maxlvt = lapic_get_maxlvt();
2608
2609 apic_pm_state.apic_id = apic_read(APIC_ID);
2610 apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2611 apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2612 apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2613 apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2614 apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2615 if (maxlvt >= 4)
2616 apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2617 apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2618 apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2619 apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2620 apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2621 apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2622#ifdef CONFIG_X86_THERMAL_VECTOR
2623 if (maxlvt >= 5)
2624 apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2625#endif
2626#ifdef CONFIG_X86_MCE_INTEL
2627 if (maxlvt >= 6)
2628 apic_pm_state.apic_cmci = apic_read(APIC_LVTCMCI);
2629#endif
2630
2631 local_irq_save(flags);
2632 disable_local_APIC();
2633
2634 irq_remapping_disable();
2635
2636 local_irq_restore(flags);
2637 return 0;
2638}
2639
2640static void lapic_resume(void)
2641{
2642 unsigned int l, h;
2643 unsigned long flags;
2644 int maxlvt;
2645
2646 if (!apic_pm_state.active)
2647 return;
2648
2649 local_irq_save(flags);
2650
2651 /*
2652 * IO-APIC and PIC have their own resume routines.
2653 * We just mask them here to make sure the interrupt
2654 * subsystem is completely quiet while we enable x2apic
2655 * and interrupt-remapping.
2656 */
2657 mask_ioapic_entries();
2658 legacy_pic->mask_all();
2659
2660 if (x2apic_mode) {
2661 __x2apic_enable();
2662 } else {
2663 /*
2664 * Make sure the APICBASE points to the right address
2665 *
2666 * FIXME! This will be wrong if we ever support suspend on
2667 * SMP! We'll need to do this as part of the CPU restore!
2668 */
2669 if (boot_cpu_data.x86 >= 6) {
2670 rdmsr(MSR_IA32_APICBASE, l, h);
2671 l &= ~MSR_IA32_APICBASE_BASE;
2672 l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2673 wrmsr(MSR_IA32_APICBASE, l, h);
2674 }
2675 }
2676
2677 maxlvt = lapic_get_maxlvt();
2678 apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2679 apic_write(APIC_ID, apic_pm_state.apic_id);
2680 apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2681 apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2682 apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2683 apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2684 apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2685 apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2686#ifdef CONFIG_X86_THERMAL_VECTOR
2687 if (maxlvt >= 5)
2688 apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2689#endif
2690#ifdef CONFIG_X86_MCE_INTEL
2691 if (maxlvt >= 6)
2692 apic_write(APIC_LVTCMCI, apic_pm_state.apic_cmci);
2693#endif
2694 if (maxlvt >= 4)
2695 apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2696 apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2697 apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2698 apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2699 apic_write(APIC_ESR, 0);
2700 apic_read(APIC_ESR);
2701 apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2702 apic_write(APIC_ESR, 0);
2703 apic_read(APIC_ESR);
2704
2705 irq_remapping_reenable(x2apic_mode);
2706
2707 local_irq_restore(flags);
2708}
2709
2710/*
2711 * This device has no shutdown method - fully functioning local APICs
2712 * are needed on every CPU up until machine_halt/restart/poweroff.
2713 */
2714
2715static struct syscore_ops lapic_syscore_ops = {
2716 .resume = lapic_resume,
2717 .suspend = lapic_suspend,
2718};
2719
2720static void apic_pm_activate(void)
2721{
2722 apic_pm_state.active = 1;
2723}
2724
2725static int __init init_lapic_sysfs(void)
2726{
2727 /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2728 if (boot_cpu_has(X86_FEATURE_APIC))
2729 register_syscore_ops(&lapic_syscore_ops);
2730
2731 return 0;
2732}
2733
2734/* local apic needs to resume before other devices access its registers. */
2735core_initcall(init_lapic_sysfs);
2736
2737#else /* CONFIG_PM */
2738
2739static void apic_pm_activate(void) { }
2740
2741#endif /* CONFIG_PM */
2742
2743#ifdef CONFIG_X86_64
2744
2745static int multi_checked;
2746static int multi;
2747
2748static int set_multi(const struct dmi_system_id *d)
2749{
2750 if (multi)
2751 return 0;
2752 pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2753 multi = 1;
2754 return 0;
2755}
2756
2757static const struct dmi_system_id multi_dmi_table[] = {
2758 {
2759 .callback = set_multi,
2760 .ident = "IBM System Summit2",
2761 .matches = {
2762 DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2763 DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2764 },
2765 },
2766 {}
2767};
2768
2769static void dmi_check_multi(void)
2770{
2771 if (multi_checked)
2772 return;
2773
2774 dmi_check_system(multi_dmi_table);
2775 multi_checked = 1;
2776}
2777
2778/*
2779 * apic_is_clustered_box() -- Check if we can expect good TSC
2780 *
2781 * Thus far, the major user of this is IBM's Summit2 series:
2782 * Clustered boxes may have unsynced TSC problems if they are
2783 * multi-chassis.
2784 * Use DMI to check them
2785 */
2786int apic_is_clustered_box(void)
2787{
2788 dmi_check_multi();
2789 return multi;
2790}
2791#endif
2792
2793/*
2794 * APIC command line parameters
2795 */
2796static int __init setup_disableapic(char *arg)
2797{
2798 disable_apic = 1;
2799 setup_clear_cpu_cap(X86_FEATURE_APIC);
2800 return 0;
2801}
2802early_param("disableapic", setup_disableapic);
2803
2804/* same as disableapic, for compatibility */
2805static int __init setup_nolapic(char *arg)
2806{
2807 return setup_disableapic(arg);
2808}
2809early_param("nolapic", setup_nolapic);
2810
2811static int __init parse_lapic_timer_c2_ok(char *arg)
2812{
2813 local_apic_timer_c2_ok = 1;
2814 return 0;
2815}
2816early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2817
2818static int __init parse_disable_apic_timer(char *arg)
2819{
2820 disable_apic_timer = 1;
2821 return 0;
2822}
2823early_param("noapictimer", parse_disable_apic_timer);
2824
2825static int __init parse_nolapic_timer(char *arg)
2826{
2827 disable_apic_timer = 1;
2828 return 0;
2829}
2830early_param("nolapic_timer", parse_nolapic_timer);
2831
2832static int __init apic_set_verbosity(char *arg)
2833{
2834 if (!arg) {
2835#ifdef CONFIG_X86_64
2836 skip_ioapic_setup = 0;
2837 return 0;
2838#endif
2839 return -EINVAL;
2840 }
2841
2842 if (strcmp("debug", arg) == 0)
2843 apic_verbosity = APIC_DEBUG;
2844 else if (strcmp("verbose", arg) == 0)
2845 apic_verbosity = APIC_VERBOSE;
2846#ifdef CONFIG_X86_64
2847 else {
2848 pr_warning("APIC Verbosity level %s not recognised"
2849 " use apic=verbose or apic=debug\n", arg);
2850 return -EINVAL;
2851 }
2852#endif
2853
2854 return 0;
2855}
2856early_param("apic", apic_set_verbosity);
2857
2858static int __init lapic_insert_resource(void)
2859{
2860 if (!apic_phys)
2861 return -1;
2862
2863 /* Put local APIC into the resource map. */
2864 lapic_resource.start = apic_phys;
2865 lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2866 insert_resource(&iomem_resource, &lapic_resource);
2867
2868 return 0;
2869}
2870
2871/*
2872 * need call insert after e820__reserve_resources()
2873 * that is using request_resource
2874 */
2875late_initcall(lapic_insert_resource);
2876
2877static int __init apic_set_disabled_cpu_apicid(char *arg)
2878{
2879 if (!arg || !get_option(&arg, &disabled_cpu_apicid))
2880 return -EINVAL;
2881
2882 return 0;
2883}
2884early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);
2885
2886static int __init apic_set_extnmi(char *arg)
2887{
2888 if (!arg)
2889 return -EINVAL;
2890
2891 if (!strncmp("all", arg, 3))
2892 apic_extnmi = APIC_EXTNMI_ALL;
2893 else if (!strncmp("none", arg, 4))
2894 apic_extnmi = APIC_EXTNMI_NONE;
2895 else if (!strncmp("bsp", arg, 3))
2896 apic_extnmi = APIC_EXTNMI_BSP;
2897 else {
2898 pr_warn("Unknown external NMI delivery mode `%s' ignored\n", arg);
2899 return -EINVAL;
2900 }
2901
2902 return 0;
2903}
2904early_param("apic_extnmi", apic_set_extnmi);
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
57unsigned int num_processors;
58
59unsigned disabled_cpus __cpuinitdata;
60
61/* Processor that is doing the boot up */
62unsigned int boot_cpu_physical_apicid = -1U;
63
64/*
65 * The highest APIC ID seen during enumeration.
66 */
67unsigned int max_physical_apicid;
68
69/*
70 * Bitmask of physically existing CPUs:
71 */
72physid_mask_t phys_cpu_present_map;
73
74/*
75 * Map cpu index to physical APIC ID
76 */
77DEFINE_EARLY_PER_CPU(u16, x86_cpu_to_apicid, BAD_APICID);
78DEFINE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid, BAD_APICID);
79EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
80EXPORT_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 */
90DEFINE_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 */
97static int force_enable_local_apic __initdata;
98/*
99 * APIC command line parameters
100 */
101static int __init parse_lapic(char *arg)
102{
103 force_enable_local_apic = 1;
104 return 0;
105}
106early_param("lapic", parse_lapic);
107/* Local APIC was disabled by the BIOS and enabled by the kernel */
108static 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 */
118static 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
126static 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
136static int apic_calibrate_pmtmr __initdata;
137static __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
146int x2apic_mode;
147#ifdef CONFIG_X86_X2APIC
148/* x2apic enabled before OS handover */
149static int x2apic_preenabled;
150static __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}
161early_param("nox2apic", setup_nox2apic);
162#endif
163
164unsigned long mp_lapic_addr;
165int disable_apic;
166/* Disable local APIC timer from the kernel commandline or via dmi quirk */
167static int disable_apic_timer __initdata;
168/* Local APIC timer works in C2 */
169int local_apic_timer_c2_ok;
170EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
171
172int first_system_vector = 0xfe;
173
174/*
175 * Debug level, exported for io_apic.c
176 */
177unsigned int apic_verbosity;
178
179int pic_mode;
180
181/* Have we found an MP table */
182int smp_found_config;
183
184static struct resource lapic_resource = {
185 .name = "Local APIC",
186 .flags = IORESOURCE_MEM | IORESOURCE_BUSY,
187};
188
189static unsigned int calibration_result;
190
191static void apic_pm_activate(void);
192
193static unsigned long apic_phys;
194
195/*
196 * Get the LAPIC version
197 */
198static 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 */
206static 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 */
218static 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 */
231static void __init apic_disable(void)
232{
233 pr_info("APIC: switched to apic NOOP\n");
234 apic = &apic_noop;
235}
236
237void native_apic_wait_icr_idle(void)
238{
239 while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
240 cpu_relax();
241}
242
243u32 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
259void 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
265u64 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 */
279int 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 */
288int 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 */
317static 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
364static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
365
366static 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
373static 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
398int 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}
427EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
428
429/*
430 * Program the next event, relative to now
431 */
432static 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 */
442static 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 */
478static 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 */
489static 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};
500static 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 */
506static 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
545static __initdata int lapic_cal_loops = -1;
546static __initdata long lapic_cal_t1, lapic_cal_t2;
547static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
548static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
549static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
550
551/*
552 * Temporary interrupt handler.
553 */
554static 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
582static int __init
583calibrate_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
633static 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 */
760void __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
799void __cpuinit setup_secondary_APIC_clock(void)
800{
801 setup_APIC_timer();
802}
803
804/*
805 * The guts of the apic timer interrupt
806 */
807static 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 */
846void __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
868int 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 */
884void 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 */
955void 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 */
994void 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 */
1019int __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 */
1078void __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 */
1100void __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
1144static 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 */
1191void __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
1384void __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
1401void __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
1415void 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
1423void 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
1438int __init enable_IR(void)
1439{
1440#ifdef CONFIG_INTR_REMAP
1441 if (!intr_remapping_supported()) {
1442 pr_debug("intr-remapping not supported\n");
1443 return 0;
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 0;
1450 }
1451
1452 if (enable_intr_remapping(x2apic_supported()))
1453 return 0;
1454
1455 pr_info("Enabled Interrupt-remapping\n");
1456
1457 return 1;
1458
1459#endif
1460 return 0;
1461}
1462
1463void __init enable_IR_x2apic(void)
1464{
1465 unsigned long flags;
1466 int ret, x2apic_enabled = 0;
1467 int dmar_table_init_ret;
1468
1469 dmar_table_init_ret = dmar_table_init();
1470 if (dmar_table_init_ret && !x2apic_supported())
1471 return;
1472
1473 ret = save_ioapic_entries();
1474 if (ret) {
1475 pr_info("Saving IO-APIC state failed: %d\n", ret);
1476 goto out;
1477 }
1478
1479 local_irq_save(flags);
1480 legacy_pic->mask_all();
1481 mask_ioapic_entries();
1482
1483 if (dmar_table_init_ret)
1484 ret = 0;
1485 else
1486 ret = enable_IR();
1487
1488 if (!ret) {
1489 /* IR is required if there is APIC ID > 255 even when running
1490 * under KVM
1491 */
1492 if (max_physical_apicid > 255 ||
1493 !hypervisor_x2apic_available())
1494 goto nox2apic;
1495 /*
1496 * without IR all CPUs can be addressed by IOAPIC/MSI
1497 * only in physical mode
1498 */
1499 x2apic_force_phys();
1500 }
1501
1502 x2apic_enabled = 1;
1503
1504 if (x2apic_supported() && !x2apic_mode) {
1505 x2apic_mode = 1;
1506 enable_x2apic();
1507 pr_info("Enabled x2apic\n");
1508 }
1509
1510nox2apic:
1511 if (!ret) /* IR enabling failed */
1512 restore_ioapic_entries();
1513 legacy_pic->restore_mask();
1514 local_irq_restore(flags);
1515
1516out:
1517 if (x2apic_enabled)
1518 return;
1519
1520 if (x2apic_preenabled)
1521 panic("x2apic: enabled by BIOS but kernel init failed.");
1522 else if (cpu_has_x2apic)
1523 pr_info("Not enabling x2apic, Intr-remapping init failed.\n");
1524}
1525
1526#ifdef CONFIG_X86_64
1527/*
1528 * Detect and enable local APICs on non-SMP boards.
1529 * Original code written by Keir Fraser.
1530 * On AMD64 we trust the BIOS - if it says no APIC it is likely
1531 * not correctly set up (usually the APIC timer won't work etc.)
1532 */
1533static int __init detect_init_APIC(void)
1534{
1535 if (!cpu_has_apic) {
1536 pr_info("No local APIC present\n");
1537 return -1;
1538 }
1539
1540 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1541 return 0;
1542}
1543#else
1544
1545static int __init apic_verify(void)
1546{
1547 u32 features, h, l;
1548
1549 /*
1550 * The APIC feature bit should now be enabled
1551 * in `cpuid'
1552 */
1553 features = cpuid_edx(1);
1554 if (!(features & (1 << X86_FEATURE_APIC))) {
1555 pr_warning("Could not enable APIC!\n");
1556 return -1;
1557 }
1558 set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1559 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1560
1561 /* The BIOS may have set up the APIC at some other address */
1562 rdmsr(MSR_IA32_APICBASE, l, h);
1563 if (l & MSR_IA32_APICBASE_ENABLE)
1564 mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1565
1566 pr_info("Found and enabled local APIC!\n");
1567 return 0;
1568}
1569
1570int __init apic_force_enable(unsigned long addr)
1571{
1572 u32 h, l;
1573
1574 if (disable_apic)
1575 return -1;
1576
1577 /*
1578 * Some BIOSes disable the local APIC in the APIC_BASE
1579 * MSR. This can only be done in software for Intel P6 or later
1580 * and AMD K7 (Model > 1) or later.
1581 */
1582 rdmsr(MSR_IA32_APICBASE, l, h);
1583 if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1584 pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1585 l &= ~MSR_IA32_APICBASE_BASE;
1586 l |= MSR_IA32_APICBASE_ENABLE | addr;
1587 wrmsr(MSR_IA32_APICBASE, l, h);
1588 enabled_via_apicbase = 1;
1589 }
1590 return apic_verify();
1591}
1592
1593/*
1594 * Detect and initialize APIC
1595 */
1596static int __init detect_init_APIC(void)
1597{
1598 /* Disabled by kernel option? */
1599 if (disable_apic)
1600 return -1;
1601
1602 switch (boot_cpu_data.x86_vendor) {
1603 case X86_VENDOR_AMD:
1604 if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1605 (boot_cpu_data.x86 >= 15))
1606 break;
1607 goto no_apic;
1608 case X86_VENDOR_INTEL:
1609 if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1610 (boot_cpu_data.x86 == 5 && cpu_has_apic))
1611 break;
1612 goto no_apic;
1613 default:
1614 goto no_apic;
1615 }
1616
1617 if (!cpu_has_apic) {
1618 /*
1619 * Over-ride BIOS and try to enable the local APIC only if
1620 * "lapic" specified.
1621 */
1622 if (!force_enable_local_apic) {
1623 pr_info("Local APIC disabled by BIOS -- "
1624 "you can enable it with \"lapic\"\n");
1625 return -1;
1626 }
1627 if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
1628 return -1;
1629 } else {
1630 if (apic_verify())
1631 return -1;
1632 }
1633
1634 apic_pm_activate();
1635
1636 return 0;
1637
1638no_apic:
1639 pr_info("No local APIC present or hardware disabled\n");
1640 return -1;
1641}
1642#endif
1643
1644/**
1645 * init_apic_mappings - initialize APIC mappings
1646 */
1647void __init init_apic_mappings(void)
1648{
1649 unsigned int new_apicid;
1650
1651 if (x2apic_mode) {
1652 boot_cpu_physical_apicid = read_apic_id();
1653 return;
1654 }
1655
1656 /* If no local APIC can be found return early */
1657 if (!smp_found_config && detect_init_APIC()) {
1658 /* lets NOP'ify apic operations */
1659 pr_info("APIC: disable apic facility\n");
1660 apic_disable();
1661 } else {
1662 apic_phys = mp_lapic_addr;
1663
1664 /*
1665 * acpi lapic path already maps that address in
1666 * acpi_register_lapic_address()
1667 */
1668 if (!acpi_lapic && !smp_found_config)
1669 register_lapic_address(apic_phys);
1670 }
1671
1672 /*
1673 * Fetch the APIC ID of the BSP in case we have a
1674 * default configuration (or the MP table is broken).
1675 */
1676 new_apicid = read_apic_id();
1677 if (boot_cpu_physical_apicid != new_apicid) {
1678 boot_cpu_physical_apicid = new_apicid;
1679 /*
1680 * yeah -- we lie about apic_version
1681 * in case if apic was disabled via boot option
1682 * but it's not a problem for SMP compiled kernel
1683 * since smp_sanity_check is prepared for such a case
1684 * and disable smp mode
1685 */
1686 apic_version[new_apicid] =
1687 GET_APIC_VERSION(apic_read(APIC_LVR));
1688 }
1689}
1690
1691void __init register_lapic_address(unsigned long address)
1692{
1693 mp_lapic_addr = address;
1694
1695 if (!x2apic_mode) {
1696 set_fixmap_nocache(FIX_APIC_BASE, address);
1697 apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
1698 APIC_BASE, mp_lapic_addr);
1699 }
1700 if (boot_cpu_physical_apicid == -1U) {
1701 boot_cpu_physical_apicid = read_apic_id();
1702 apic_version[boot_cpu_physical_apicid] =
1703 GET_APIC_VERSION(apic_read(APIC_LVR));
1704 }
1705}
1706
1707/*
1708 * This initializes the IO-APIC and APIC hardware if this is
1709 * a UP kernel.
1710 */
1711int apic_version[MAX_LOCAL_APIC];
1712
1713int __init APIC_init_uniprocessor(void)
1714{
1715 if (disable_apic) {
1716 pr_info("Apic disabled\n");
1717 return -1;
1718 }
1719#ifdef CONFIG_X86_64
1720 if (!cpu_has_apic) {
1721 disable_apic = 1;
1722 pr_info("Apic disabled by BIOS\n");
1723 return -1;
1724 }
1725#else
1726 if (!smp_found_config && !cpu_has_apic)
1727 return -1;
1728
1729 /*
1730 * Complain if the BIOS pretends there is one.
1731 */
1732 if (!cpu_has_apic &&
1733 APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
1734 pr_err("BIOS bug, local APIC 0x%x not detected!...\n",
1735 boot_cpu_physical_apicid);
1736 return -1;
1737 }
1738#endif
1739
1740 default_setup_apic_routing();
1741
1742 verify_local_APIC();
1743 connect_bsp_APIC();
1744
1745#ifdef CONFIG_X86_64
1746 apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
1747#else
1748 /*
1749 * Hack: In case of kdump, after a crash, kernel might be booting
1750 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
1751 * might be zero if read from MP tables. Get it from LAPIC.
1752 */
1753# ifdef CONFIG_CRASH_DUMP
1754 boot_cpu_physical_apicid = read_apic_id();
1755# endif
1756#endif
1757 physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
1758 setup_local_APIC();
1759
1760#ifdef CONFIG_X86_IO_APIC
1761 /*
1762 * Now enable IO-APICs, actually call clear_IO_APIC
1763 * We need clear_IO_APIC before enabling error vector
1764 */
1765 if (!skip_ioapic_setup && nr_ioapics)
1766 enable_IO_APIC();
1767#endif
1768
1769 bsp_end_local_APIC_setup();
1770
1771#ifdef CONFIG_X86_IO_APIC
1772 if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1773 setup_IO_APIC();
1774 else {
1775 nr_ioapics = 0;
1776 }
1777#endif
1778
1779 x86_init.timers.setup_percpu_clockev();
1780 return 0;
1781}
1782
1783/*
1784 * Local APIC interrupts
1785 */
1786
1787/*
1788 * This interrupt should _never_ happen with our APIC/SMP architecture
1789 */
1790void smp_spurious_interrupt(struct pt_regs *regs)
1791{
1792 u32 v;
1793
1794 exit_idle();
1795 irq_enter();
1796 /*
1797 * Check if this really is a spurious interrupt and ACK it
1798 * if it is a vectored one. Just in case...
1799 * Spurious interrupts should not be ACKed.
1800 */
1801 v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1802 if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1803 ack_APIC_irq();
1804
1805 inc_irq_stat(irq_spurious_count);
1806
1807 /* see sw-dev-man vol 3, chapter 7.4.13.5 */
1808 pr_info("spurious APIC interrupt on CPU#%d, "
1809 "should never happen.\n", smp_processor_id());
1810 irq_exit();
1811}
1812
1813/*
1814 * This interrupt should never happen with our APIC/SMP architecture
1815 */
1816void smp_error_interrupt(struct pt_regs *regs)
1817{
1818 u32 v0, v1;
1819 u32 i = 0;
1820 static const char * const error_interrupt_reason[] = {
1821 "Send CS error", /* APIC Error Bit 0 */
1822 "Receive CS error", /* APIC Error Bit 1 */
1823 "Send accept error", /* APIC Error Bit 2 */
1824 "Receive accept error", /* APIC Error Bit 3 */
1825 "Redirectable IPI", /* APIC Error Bit 4 */
1826 "Send illegal vector", /* APIC Error Bit 5 */
1827 "Received illegal vector", /* APIC Error Bit 6 */
1828 "Illegal register address", /* APIC Error Bit 7 */
1829 };
1830
1831 exit_idle();
1832 irq_enter();
1833 /* First tickle the hardware, only then report what went on. -- REW */
1834 v0 = apic_read(APIC_ESR);
1835 apic_write(APIC_ESR, 0);
1836 v1 = apic_read(APIC_ESR);
1837 ack_APIC_irq();
1838 atomic_inc(&irq_err_count);
1839
1840 apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x(%02x)",
1841 smp_processor_id(), v0 , v1);
1842
1843 v1 = v1 & 0xff;
1844 while (v1) {
1845 if (v1 & 0x1)
1846 apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
1847 i++;
1848 v1 >>= 1;
1849 };
1850
1851 apic_printk(APIC_DEBUG, KERN_CONT "\n");
1852
1853 irq_exit();
1854}
1855
1856/**
1857 * connect_bsp_APIC - attach the APIC to the interrupt system
1858 */
1859void __init connect_bsp_APIC(void)
1860{
1861#ifdef CONFIG_X86_32
1862 if (pic_mode) {
1863 /*
1864 * Do not trust the local APIC being empty at bootup.
1865 */
1866 clear_local_APIC();
1867 /*
1868 * PIC mode, enable APIC mode in the IMCR, i.e. connect BSP's
1869 * local APIC to INT and NMI lines.
1870 */
1871 apic_printk(APIC_VERBOSE, "leaving PIC mode, "
1872 "enabling APIC mode.\n");
1873 imcr_pic_to_apic();
1874 }
1875#endif
1876 if (apic->enable_apic_mode)
1877 apic->enable_apic_mode();
1878}
1879
1880/**
1881 * disconnect_bsp_APIC - detach the APIC from the interrupt system
1882 * @virt_wire_setup: indicates, whether virtual wire mode is selected
1883 *
1884 * Virtual wire mode is necessary to deliver legacy interrupts even when the
1885 * APIC is disabled.
1886 */
1887void disconnect_bsp_APIC(int virt_wire_setup)
1888{
1889 unsigned int value;
1890
1891#ifdef CONFIG_X86_32
1892 if (pic_mode) {
1893 /*
1894 * Put the board back into PIC mode (has an effect only on
1895 * certain older boards). Note that APIC interrupts, including
1896 * IPIs, won't work beyond this point! The only exception are
1897 * INIT IPIs.
1898 */
1899 apic_printk(APIC_VERBOSE, "disabling APIC mode, "
1900 "entering PIC mode.\n");
1901 imcr_apic_to_pic();
1902 return;
1903 }
1904#endif
1905
1906 /* Go back to Virtual Wire compatibility mode */
1907
1908 /* For the spurious interrupt use vector F, and enable it */
1909 value = apic_read(APIC_SPIV);
1910 value &= ~APIC_VECTOR_MASK;
1911 value |= APIC_SPIV_APIC_ENABLED;
1912 value |= 0xf;
1913 apic_write(APIC_SPIV, value);
1914
1915 if (!virt_wire_setup) {
1916 /*
1917 * For LVT0 make it edge triggered, active high,
1918 * external and enabled
1919 */
1920 value = apic_read(APIC_LVT0);
1921 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1922 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1923 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1924 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1925 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1926 apic_write(APIC_LVT0, value);
1927 } else {
1928 /* Disable LVT0 */
1929 apic_write(APIC_LVT0, APIC_LVT_MASKED);
1930 }
1931
1932 /*
1933 * For LVT1 make it edge triggered, active high,
1934 * nmi and enabled
1935 */
1936 value = apic_read(APIC_LVT1);
1937 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1938 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1939 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1940 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1941 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1942 apic_write(APIC_LVT1, value);
1943}
1944
1945void __cpuinit generic_processor_info(int apicid, int version)
1946{
1947 int cpu, max = nr_cpu_ids;
1948 bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
1949 phys_cpu_present_map);
1950
1951 /*
1952 * If boot cpu has not been detected yet, then only allow upto
1953 * nr_cpu_ids - 1 processors and keep one slot free for boot cpu
1954 */
1955 if (!boot_cpu_detected && num_processors >= nr_cpu_ids - 1 &&
1956 apicid != boot_cpu_physical_apicid) {
1957 int thiscpu = max + disabled_cpus - 1;
1958
1959 pr_warning(
1960 "ACPI: NR_CPUS/possible_cpus limit of %i almost"
1961 " reached. Keeping one slot for boot cpu."
1962 " Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
1963
1964 disabled_cpus++;
1965 return;
1966 }
1967
1968 if (num_processors >= nr_cpu_ids) {
1969 int thiscpu = max + disabled_cpus;
1970
1971 pr_warning(
1972 "ACPI: NR_CPUS/possible_cpus limit of %i reached."
1973 " Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
1974
1975 disabled_cpus++;
1976 return;
1977 }
1978
1979 num_processors++;
1980 if (apicid == boot_cpu_physical_apicid) {
1981 /*
1982 * x86_bios_cpu_apicid is required to have processors listed
1983 * in same order as logical cpu numbers. Hence the first
1984 * entry is BSP, and so on.
1985 * boot_cpu_init() already hold bit 0 in cpu_present_mask
1986 * for BSP.
1987 */
1988 cpu = 0;
1989 } else
1990 cpu = cpumask_next_zero(-1, cpu_present_mask);
1991
1992 /*
1993 * Validate version
1994 */
1995 if (version == 0x0) {
1996 pr_warning("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
1997 cpu, apicid);
1998 version = 0x10;
1999 }
2000 apic_version[apicid] = version;
2001
2002 if (version != apic_version[boot_cpu_physical_apicid]) {
2003 pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
2004 apic_version[boot_cpu_physical_apicid], cpu, version);
2005 }
2006
2007 physid_set(apicid, phys_cpu_present_map);
2008 if (apicid > max_physical_apicid)
2009 max_physical_apicid = apicid;
2010
2011#if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
2012 early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
2013 early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
2014#endif
2015#ifdef CONFIG_X86_32
2016 early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
2017 apic->x86_32_early_logical_apicid(cpu);
2018#endif
2019 set_cpu_possible(cpu, true);
2020 set_cpu_present(cpu, true);
2021}
2022
2023int hard_smp_processor_id(void)
2024{
2025 return read_apic_id();
2026}
2027
2028void default_init_apic_ldr(void)
2029{
2030 unsigned long val;
2031
2032 apic_write(APIC_DFR, APIC_DFR_VALUE);
2033 val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
2034 val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
2035 apic_write(APIC_LDR, val);
2036}
2037
2038/*
2039 * Power management
2040 */
2041#ifdef CONFIG_PM
2042
2043static struct {
2044 /*
2045 * 'active' is true if the local APIC was enabled by us and
2046 * not the BIOS; this signifies that we are also responsible
2047 * for disabling it before entering apm/acpi suspend
2048 */
2049 int active;
2050 /* r/w apic fields */
2051 unsigned int apic_id;
2052 unsigned int apic_taskpri;
2053 unsigned int apic_ldr;
2054 unsigned int apic_dfr;
2055 unsigned int apic_spiv;
2056 unsigned int apic_lvtt;
2057 unsigned int apic_lvtpc;
2058 unsigned int apic_lvt0;
2059 unsigned int apic_lvt1;
2060 unsigned int apic_lvterr;
2061 unsigned int apic_tmict;
2062 unsigned int apic_tdcr;
2063 unsigned int apic_thmr;
2064} apic_pm_state;
2065
2066static int lapic_suspend(void)
2067{
2068 unsigned long flags;
2069 int maxlvt;
2070
2071 if (!apic_pm_state.active)
2072 return 0;
2073
2074 maxlvt = lapic_get_maxlvt();
2075
2076 apic_pm_state.apic_id = apic_read(APIC_ID);
2077 apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2078 apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2079 apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2080 apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2081 apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2082 if (maxlvt >= 4)
2083 apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2084 apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2085 apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2086 apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2087 apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2088 apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2089#ifdef CONFIG_X86_THERMAL_VECTOR
2090 if (maxlvt >= 5)
2091 apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2092#endif
2093
2094 local_irq_save(flags);
2095 disable_local_APIC();
2096
2097 if (intr_remapping_enabled)
2098 disable_intr_remapping();
2099
2100 local_irq_restore(flags);
2101 return 0;
2102}
2103
2104static void lapic_resume(void)
2105{
2106 unsigned int l, h;
2107 unsigned long flags;
2108 int maxlvt;
2109
2110 if (!apic_pm_state.active)
2111 return;
2112
2113 local_irq_save(flags);
2114 if (intr_remapping_enabled) {
2115 /*
2116 * IO-APIC and PIC have their own resume routines.
2117 * We just mask them here to make sure the interrupt
2118 * subsystem is completely quiet while we enable x2apic
2119 * and interrupt-remapping.
2120 */
2121 mask_ioapic_entries();
2122 legacy_pic->mask_all();
2123 }
2124
2125 if (x2apic_mode)
2126 enable_x2apic();
2127 else {
2128 /*
2129 * Make sure the APICBASE points to the right address
2130 *
2131 * FIXME! This will be wrong if we ever support suspend on
2132 * SMP! We'll need to do this as part of the CPU restore!
2133 */
2134 rdmsr(MSR_IA32_APICBASE, l, h);
2135 l &= ~MSR_IA32_APICBASE_BASE;
2136 l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2137 wrmsr(MSR_IA32_APICBASE, l, h);
2138 }
2139
2140 maxlvt = lapic_get_maxlvt();
2141 apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2142 apic_write(APIC_ID, apic_pm_state.apic_id);
2143 apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2144 apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2145 apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2146 apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2147 apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2148 apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2149#if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
2150 if (maxlvt >= 5)
2151 apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2152#endif
2153 if (maxlvt >= 4)
2154 apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2155 apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2156 apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2157 apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2158 apic_write(APIC_ESR, 0);
2159 apic_read(APIC_ESR);
2160 apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2161 apic_write(APIC_ESR, 0);
2162 apic_read(APIC_ESR);
2163
2164 if (intr_remapping_enabled)
2165 reenable_intr_remapping(x2apic_mode);
2166
2167 local_irq_restore(flags);
2168}
2169
2170/*
2171 * This device has no shutdown method - fully functioning local APICs
2172 * are needed on every CPU up until machine_halt/restart/poweroff.
2173 */
2174
2175static struct syscore_ops lapic_syscore_ops = {
2176 .resume = lapic_resume,
2177 .suspend = lapic_suspend,
2178};
2179
2180static void __cpuinit apic_pm_activate(void)
2181{
2182 apic_pm_state.active = 1;
2183}
2184
2185static int __init init_lapic_sysfs(void)
2186{
2187 /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2188 if (cpu_has_apic)
2189 register_syscore_ops(&lapic_syscore_ops);
2190
2191 return 0;
2192}
2193
2194/* local apic needs to resume before other devices access its registers. */
2195core_initcall(init_lapic_sysfs);
2196
2197#else /* CONFIG_PM */
2198
2199static void apic_pm_activate(void) { }
2200
2201#endif /* CONFIG_PM */
2202
2203#ifdef CONFIG_X86_64
2204
2205static int __cpuinit apic_cluster_num(void)
2206{
2207 int i, clusters, zeros;
2208 unsigned id;
2209 u16 *bios_cpu_apicid;
2210 DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
2211
2212 bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
2213 bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
2214
2215 for (i = 0; i < nr_cpu_ids; i++) {
2216 /* are we being called early in kernel startup? */
2217 if (bios_cpu_apicid) {
2218 id = bios_cpu_apicid[i];
2219 } else if (i < nr_cpu_ids) {
2220 if (cpu_present(i))
2221 id = per_cpu(x86_bios_cpu_apicid, i);
2222 else
2223 continue;
2224 } else
2225 break;
2226
2227 if (id != BAD_APICID)
2228 __set_bit(APIC_CLUSTERID(id), clustermap);
2229 }
2230
2231 /* Problem: Partially populated chassis may not have CPUs in some of
2232 * the APIC clusters they have been allocated. Only present CPUs have
2233 * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap.
2234 * Since clusters are allocated sequentially, count zeros only if
2235 * they are bounded by ones.
2236 */
2237 clusters = 0;
2238 zeros = 0;
2239 for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
2240 if (test_bit(i, clustermap)) {
2241 clusters += 1 + zeros;
2242 zeros = 0;
2243 } else
2244 ++zeros;
2245 }
2246
2247 return clusters;
2248}
2249
2250static int __cpuinitdata multi_checked;
2251static int __cpuinitdata multi;
2252
2253static int __cpuinit set_multi(const struct dmi_system_id *d)
2254{
2255 if (multi)
2256 return 0;
2257 pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2258 multi = 1;
2259 return 0;
2260}
2261
2262static const __cpuinitconst struct dmi_system_id multi_dmi_table[] = {
2263 {
2264 .callback = set_multi,
2265 .ident = "IBM System Summit2",
2266 .matches = {
2267 DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2268 DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2269 },
2270 },
2271 {}
2272};
2273
2274static void __cpuinit dmi_check_multi(void)
2275{
2276 if (multi_checked)
2277 return;
2278
2279 dmi_check_system(multi_dmi_table);
2280 multi_checked = 1;
2281}
2282
2283/*
2284 * apic_is_clustered_box() -- Check if we can expect good TSC
2285 *
2286 * Thus far, the major user of this is IBM's Summit2 series:
2287 * Clustered boxes may have unsynced TSC problems if they are
2288 * multi-chassis.
2289 * Use DMI to check them
2290 */
2291__cpuinit int apic_is_clustered_box(void)
2292{
2293 dmi_check_multi();
2294 if (multi)
2295 return 1;
2296
2297 if (!is_vsmp_box())
2298 return 0;
2299
2300 /*
2301 * ScaleMP vSMPowered boxes have one cluster per board and TSCs are
2302 * not guaranteed to be synced between boards
2303 */
2304 if (apic_cluster_num() > 1)
2305 return 1;
2306
2307 return 0;
2308}
2309#endif
2310
2311/*
2312 * APIC command line parameters
2313 */
2314static int __init setup_disableapic(char *arg)
2315{
2316 disable_apic = 1;
2317 setup_clear_cpu_cap(X86_FEATURE_APIC);
2318 return 0;
2319}
2320early_param("disableapic", setup_disableapic);
2321
2322/* same as disableapic, for compatibility */
2323static int __init setup_nolapic(char *arg)
2324{
2325 return setup_disableapic(arg);
2326}
2327early_param("nolapic", setup_nolapic);
2328
2329static int __init parse_lapic_timer_c2_ok(char *arg)
2330{
2331 local_apic_timer_c2_ok = 1;
2332 return 0;
2333}
2334early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2335
2336static int __init parse_disable_apic_timer(char *arg)
2337{
2338 disable_apic_timer = 1;
2339 return 0;
2340}
2341early_param("noapictimer", parse_disable_apic_timer);
2342
2343static int __init parse_nolapic_timer(char *arg)
2344{
2345 disable_apic_timer = 1;
2346 return 0;
2347}
2348early_param("nolapic_timer", parse_nolapic_timer);
2349
2350static int __init apic_set_verbosity(char *arg)
2351{
2352 if (!arg) {
2353#ifdef CONFIG_X86_64
2354 skip_ioapic_setup = 0;
2355 return 0;
2356#endif
2357 return -EINVAL;
2358 }
2359
2360 if (strcmp("debug", arg) == 0)
2361 apic_verbosity = APIC_DEBUG;
2362 else if (strcmp("verbose", arg) == 0)
2363 apic_verbosity = APIC_VERBOSE;
2364 else {
2365 pr_warning("APIC Verbosity level %s not recognised"
2366 " use apic=verbose or apic=debug\n", arg);
2367 return -EINVAL;
2368 }
2369
2370 return 0;
2371}
2372early_param("apic", apic_set_verbosity);
2373
2374static int __init lapic_insert_resource(void)
2375{
2376 if (!apic_phys)
2377 return -1;
2378
2379 /* Put local APIC into the resource map. */
2380 lapic_resource.start = apic_phys;
2381 lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2382 insert_resource(&iomem_resource, &lapic_resource);
2383
2384 return 0;
2385}
2386
2387/*
2388 * need call insert after e820_reserve_resources()
2389 * that is using request_resource
2390 */
2391late_initcall(lapic_insert_resource);