xref: /openbmc/linux/arch/x86/kernel/apic/vector.c (revision a06c488d)
1 /*
2  * Local APIC related interfaces to support IOAPIC, MSI, HT_IRQ etc.
3  *
4  * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
5  *	Moved from arch/x86/kernel/apic/io_apic.c.
6  * Jiang Liu <jiang.liu@linux.intel.com>
7  *	Enable support of hierarchical irqdomains
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 #include <linux/interrupt.h>
14 #include <linux/init.h>
15 #include <linux/compiler.h>
16 #include <linux/slab.h>
17 #include <asm/irqdomain.h>
18 #include <asm/hw_irq.h>
19 #include <asm/apic.h>
20 #include <asm/i8259.h>
21 #include <asm/desc.h>
22 #include <asm/irq_remapping.h>
23 
24 struct apic_chip_data {
25 	struct irq_cfg		cfg;
26 	cpumask_var_t		domain;
27 	cpumask_var_t		old_domain;
28 	u8			move_in_progress : 1;
29 };
30 
31 struct irq_domain *x86_vector_domain;
32 EXPORT_SYMBOL_GPL(x86_vector_domain);
33 static DEFINE_RAW_SPINLOCK(vector_lock);
34 static cpumask_var_t vector_cpumask;
35 static struct irq_chip lapic_controller;
36 #ifdef	CONFIG_X86_IO_APIC
37 static struct apic_chip_data *legacy_irq_data[NR_IRQS_LEGACY];
38 #endif
39 
40 void lock_vector_lock(void)
41 {
42 	/* Used to the online set of cpus does not change
43 	 * during assign_irq_vector.
44 	 */
45 	raw_spin_lock(&vector_lock);
46 }
47 
48 void unlock_vector_lock(void)
49 {
50 	raw_spin_unlock(&vector_lock);
51 }
52 
53 static struct apic_chip_data *apic_chip_data(struct irq_data *irq_data)
54 {
55 	if (!irq_data)
56 		return NULL;
57 
58 	while (irq_data->parent_data)
59 		irq_data = irq_data->parent_data;
60 
61 	return irq_data->chip_data;
62 }
63 
64 struct irq_cfg *irqd_cfg(struct irq_data *irq_data)
65 {
66 	struct apic_chip_data *data = apic_chip_data(irq_data);
67 
68 	return data ? &data->cfg : NULL;
69 }
70 EXPORT_SYMBOL_GPL(irqd_cfg);
71 
72 struct irq_cfg *irq_cfg(unsigned int irq)
73 {
74 	return irqd_cfg(irq_get_irq_data(irq));
75 }
76 
77 static struct apic_chip_data *alloc_apic_chip_data(int node)
78 {
79 	struct apic_chip_data *data;
80 
81 	data = kzalloc_node(sizeof(*data), GFP_KERNEL, node);
82 	if (!data)
83 		return NULL;
84 	if (!zalloc_cpumask_var_node(&data->domain, GFP_KERNEL, node))
85 		goto out_data;
86 	if (!zalloc_cpumask_var_node(&data->old_domain, GFP_KERNEL, node))
87 		goto out_domain;
88 	return data;
89 out_domain:
90 	free_cpumask_var(data->domain);
91 out_data:
92 	kfree(data);
93 	return NULL;
94 }
95 
96 static void free_apic_chip_data(struct apic_chip_data *data)
97 {
98 	if (data) {
99 		free_cpumask_var(data->domain);
100 		free_cpumask_var(data->old_domain);
101 		kfree(data);
102 	}
103 }
104 
105 static int __assign_irq_vector(int irq, struct apic_chip_data *d,
106 			       const struct cpumask *mask)
107 {
108 	/*
109 	 * NOTE! The local APIC isn't very good at handling
110 	 * multiple interrupts at the same interrupt level.
111 	 * As the interrupt level is determined by taking the
112 	 * vector number and shifting that right by 4, we
113 	 * want to spread these out a bit so that they don't
114 	 * all fall in the same interrupt level.
115 	 *
116 	 * Also, we've got to be careful not to trash gate
117 	 * 0x80, because int 0x80 is hm, kind of importantish. ;)
118 	 */
119 	static int current_vector = FIRST_EXTERNAL_VECTOR + VECTOR_OFFSET_START;
120 	static int current_offset = VECTOR_OFFSET_START % 16;
121 	int cpu, err;
122 
123 	if (d->move_in_progress)
124 		return -EBUSY;
125 
126 	/* Only try and allocate irqs on cpus that are present */
127 	err = -ENOSPC;
128 	cpumask_clear(d->old_domain);
129 	cpu = cpumask_first_and(mask, cpu_online_mask);
130 	while (cpu < nr_cpu_ids) {
131 		int new_cpu, vector, offset;
132 
133 		apic->vector_allocation_domain(cpu, vector_cpumask, mask);
134 
135 		if (cpumask_subset(vector_cpumask, d->domain)) {
136 			err = 0;
137 			if (cpumask_equal(vector_cpumask, d->domain))
138 				break;
139 			/*
140 			 * New cpumask using the vector is a proper subset of
141 			 * the current in use mask. So cleanup the vector
142 			 * allocation for the members that are not used anymore.
143 			 */
144 			cpumask_andnot(d->old_domain, d->domain,
145 				       vector_cpumask);
146 			d->move_in_progress =
147 			   cpumask_intersects(d->old_domain, cpu_online_mask);
148 			cpumask_and(d->domain, d->domain, vector_cpumask);
149 			break;
150 		}
151 
152 		vector = current_vector;
153 		offset = current_offset;
154 next:
155 		vector += 16;
156 		if (vector >= first_system_vector) {
157 			offset = (offset + 1) % 16;
158 			vector = FIRST_EXTERNAL_VECTOR + offset;
159 		}
160 
161 		if (unlikely(current_vector == vector)) {
162 			cpumask_or(d->old_domain, d->old_domain,
163 				   vector_cpumask);
164 			cpumask_andnot(vector_cpumask, mask, d->old_domain);
165 			cpu = cpumask_first_and(vector_cpumask,
166 						cpu_online_mask);
167 			continue;
168 		}
169 
170 		if (test_bit(vector, used_vectors))
171 			goto next;
172 
173 		for_each_cpu_and(new_cpu, vector_cpumask, cpu_online_mask) {
174 			if (!IS_ERR_OR_NULL(per_cpu(vector_irq, new_cpu)[vector]))
175 				goto next;
176 		}
177 		/* Found one! */
178 		current_vector = vector;
179 		current_offset = offset;
180 		if (d->cfg.vector) {
181 			cpumask_copy(d->old_domain, d->domain);
182 			d->move_in_progress =
183 			   cpumask_intersects(d->old_domain, cpu_online_mask);
184 		}
185 		for_each_cpu_and(new_cpu, vector_cpumask, cpu_online_mask)
186 			per_cpu(vector_irq, new_cpu)[vector] = irq_to_desc(irq);
187 		d->cfg.vector = vector;
188 		cpumask_copy(d->domain, vector_cpumask);
189 		err = 0;
190 		break;
191 	}
192 
193 	if (!err) {
194 		/* cache destination APIC IDs into cfg->dest_apicid */
195 		err = apic->cpu_mask_to_apicid_and(mask, d->domain,
196 						   &d->cfg.dest_apicid);
197 	}
198 
199 	return err;
200 }
201 
202 static int assign_irq_vector(int irq, struct apic_chip_data *data,
203 			     const struct cpumask *mask)
204 {
205 	int err;
206 	unsigned long flags;
207 
208 	raw_spin_lock_irqsave(&vector_lock, flags);
209 	err = __assign_irq_vector(irq, data, mask);
210 	raw_spin_unlock_irqrestore(&vector_lock, flags);
211 	return err;
212 }
213 
214 static int assign_irq_vector_policy(int irq, int node,
215 				    struct apic_chip_data *data,
216 				    struct irq_alloc_info *info)
217 {
218 	if (info && info->mask)
219 		return assign_irq_vector(irq, data, info->mask);
220 	if (node != NUMA_NO_NODE &&
221 	    assign_irq_vector(irq, data, cpumask_of_node(node)) == 0)
222 		return 0;
223 	return assign_irq_vector(irq, data, apic->target_cpus());
224 }
225 
226 static void clear_irq_vector(int irq, struct apic_chip_data *data)
227 {
228 	struct irq_desc *desc;
229 	unsigned long flags;
230 	int cpu, vector;
231 
232 	raw_spin_lock_irqsave(&vector_lock, flags);
233 	BUG_ON(!data->cfg.vector);
234 
235 	vector = data->cfg.vector;
236 	for_each_cpu_and(cpu, data->domain, cpu_online_mask)
237 		per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED;
238 
239 	data->cfg.vector = 0;
240 	cpumask_clear(data->domain);
241 
242 	if (likely(!data->move_in_progress)) {
243 		raw_spin_unlock_irqrestore(&vector_lock, flags);
244 		return;
245 	}
246 
247 	desc = irq_to_desc(irq);
248 	for_each_cpu_and(cpu, data->old_domain, cpu_online_mask) {
249 		for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS;
250 		     vector++) {
251 			if (per_cpu(vector_irq, cpu)[vector] != desc)
252 				continue;
253 			per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED;
254 			break;
255 		}
256 	}
257 	data->move_in_progress = 0;
258 	raw_spin_unlock_irqrestore(&vector_lock, flags);
259 }
260 
261 void init_irq_alloc_info(struct irq_alloc_info *info,
262 			 const struct cpumask *mask)
263 {
264 	memset(info, 0, sizeof(*info));
265 	info->mask = mask;
266 }
267 
268 void copy_irq_alloc_info(struct irq_alloc_info *dst, struct irq_alloc_info *src)
269 {
270 	if (src)
271 		*dst = *src;
272 	else
273 		memset(dst, 0, sizeof(*dst));
274 }
275 
276 static void x86_vector_free_irqs(struct irq_domain *domain,
277 				 unsigned int virq, unsigned int nr_irqs)
278 {
279 	struct irq_data *irq_data;
280 	int i;
281 
282 	for (i = 0; i < nr_irqs; i++) {
283 		irq_data = irq_domain_get_irq_data(x86_vector_domain, virq + i);
284 		if (irq_data && irq_data->chip_data) {
285 			clear_irq_vector(virq + i, irq_data->chip_data);
286 			free_apic_chip_data(irq_data->chip_data);
287 #ifdef	CONFIG_X86_IO_APIC
288 			if (virq + i < nr_legacy_irqs())
289 				legacy_irq_data[virq + i] = NULL;
290 #endif
291 			irq_domain_reset_irq_data(irq_data);
292 		}
293 	}
294 }
295 
296 static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq,
297 				 unsigned int nr_irqs, void *arg)
298 {
299 	struct irq_alloc_info *info = arg;
300 	struct apic_chip_data *data;
301 	struct irq_data *irq_data;
302 	int i, err, node;
303 
304 	if (disable_apic)
305 		return -ENXIO;
306 
307 	/* Currently vector allocator can't guarantee contiguous allocations */
308 	if ((info->flags & X86_IRQ_ALLOC_CONTIGUOUS_VECTORS) && nr_irqs > 1)
309 		return -ENOSYS;
310 
311 	for (i = 0; i < nr_irqs; i++) {
312 		irq_data = irq_domain_get_irq_data(domain, virq + i);
313 		BUG_ON(!irq_data);
314 		node = irq_data_get_node(irq_data);
315 #ifdef	CONFIG_X86_IO_APIC
316 		if (virq + i < nr_legacy_irqs() && legacy_irq_data[virq + i])
317 			data = legacy_irq_data[virq + i];
318 		else
319 #endif
320 			data = alloc_apic_chip_data(node);
321 		if (!data) {
322 			err = -ENOMEM;
323 			goto error;
324 		}
325 
326 		irq_data->chip = &lapic_controller;
327 		irq_data->chip_data = data;
328 		irq_data->hwirq = virq + i;
329 		err = assign_irq_vector_policy(virq + i, node, data, info);
330 		if (err)
331 			goto error;
332 	}
333 
334 	return 0;
335 
336 error:
337 	x86_vector_free_irqs(domain, virq, i + 1);
338 	return err;
339 }
340 
341 static const struct irq_domain_ops x86_vector_domain_ops = {
342 	.alloc	= x86_vector_alloc_irqs,
343 	.free	= x86_vector_free_irqs,
344 };
345 
346 int __init arch_probe_nr_irqs(void)
347 {
348 	int nr;
349 
350 	if (nr_irqs > (NR_VECTORS * nr_cpu_ids))
351 		nr_irqs = NR_VECTORS * nr_cpu_ids;
352 
353 	nr = (gsi_top + nr_legacy_irqs()) + 8 * nr_cpu_ids;
354 #if defined(CONFIG_PCI_MSI) || defined(CONFIG_HT_IRQ)
355 	/*
356 	 * for MSI and HT dyn irq
357 	 */
358 	if (gsi_top <= NR_IRQS_LEGACY)
359 		nr +=  8 * nr_cpu_ids;
360 	else
361 		nr += gsi_top * 16;
362 #endif
363 	if (nr < nr_irqs)
364 		nr_irqs = nr;
365 
366 	/*
367 	 * We don't know if PIC is present at this point so we need to do
368 	 * probe() to get the right number of legacy IRQs.
369 	 */
370 	return legacy_pic->probe();
371 }
372 
373 #ifdef	CONFIG_X86_IO_APIC
374 static void init_legacy_irqs(void)
375 {
376 	int i, node = cpu_to_node(0);
377 	struct apic_chip_data *data;
378 
379 	/*
380 	 * For legacy IRQ's, start with assigning irq0 to irq15 to
381 	 * ISA_IRQ_VECTOR(i) for all cpu's.
382 	 */
383 	for (i = 0; i < nr_legacy_irqs(); i++) {
384 		data = legacy_irq_data[i] = alloc_apic_chip_data(node);
385 		BUG_ON(!data);
386 
387 		data->cfg.vector = ISA_IRQ_VECTOR(i);
388 		cpumask_setall(data->domain);
389 		irq_set_chip_data(i, data);
390 	}
391 }
392 #else
393 static void init_legacy_irqs(void) { }
394 #endif
395 
396 int __init arch_early_irq_init(void)
397 {
398 	init_legacy_irqs();
399 
400 	x86_vector_domain = irq_domain_add_tree(NULL, &x86_vector_domain_ops,
401 						NULL);
402 	BUG_ON(x86_vector_domain == NULL);
403 	irq_set_default_host(x86_vector_domain);
404 
405 	arch_init_msi_domain(x86_vector_domain);
406 	arch_init_htirq_domain(x86_vector_domain);
407 
408 	BUG_ON(!alloc_cpumask_var(&vector_cpumask, GFP_KERNEL));
409 
410 	return arch_early_ioapic_init();
411 }
412 
413 /* Initialize vector_irq on a new cpu */
414 static void __setup_vector_irq(int cpu)
415 {
416 	struct apic_chip_data *data;
417 	struct irq_desc *desc;
418 	int irq, vector;
419 
420 	/* Mark the inuse vectors */
421 	for_each_irq_desc(irq, desc) {
422 		struct irq_data *idata = irq_desc_get_irq_data(desc);
423 
424 		data = apic_chip_data(idata);
425 		if (!data || !cpumask_test_cpu(cpu, data->domain))
426 			continue;
427 		vector = data->cfg.vector;
428 		per_cpu(vector_irq, cpu)[vector] = desc;
429 	}
430 	/* Mark the free vectors */
431 	for (vector = 0; vector < NR_VECTORS; ++vector) {
432 		desc = per_cpu(vector_irq, cpu)[vector];
433 		if (IS_ERR_OR_NULL(desc))
434 			continue;
435 
436 		data = apic_chip_data(irq_desc_get_irq_data(desc));
437 		if (!cpumask_test_cpu(cpu, data->domain))
438 			per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED;
439 	}
440 }
441 
442 /*
443  * Setup the vector to irq mappings. Must be called with vector_lock held.
444  */
445 void setup_vector_irq(int cpu)
446 {
447 	int irq;
448 
449 	lockdep_assert_held(&vector_lock);
450 	/*
451 	 * On most of the platforms, legacy PIC delivers the interrupts on the
452 	 * boot cpu. But there are certain platforms where PIC interrupts are
453 	 * delivered to multiple cpu's. If the legacy IRQ is handled by the
454 	 * legacy PIC, for the new cpu that is coming online, setup the static
455 	 * legacy vector to irq mapping:
456 	 */
457 	for (irq = 0; irq < nr_legacy_irqs(); irq++)
458 		per_cpu(vector_irq, cpu)[ISA_IRQ_VECTOR(irq)] = irq_to_desc(irq);
459 
460 	__setup_vector_irq(cpu);
461 }
462 
463 static int apic_retrigger_irq(struct irq_data *irq_data)
464 {
465 	struct apic_chip_data *data = apic_chip_data(irq_data);
466 	unsigned long flags;
467 	int cpu;
468 
469 	raw_spin_lock_irqsave(&vector_lock, flags);
470 	cpu = cpumask_first_and(data->domain, cpu_online_mask);
471 	apic->send_IPI_mask(cpumask_of(cpu), data->cfg.vector);
472 	raw_spin_unlock_irqrestore(&vector_lock, flags);
473 
474 	return 1;
475 }
476 
477 void apic_ack_edge(struct irq_data *data)
478 {
479 	irq_complete_move(irqd_cfg(data));
480 	irq_move_irq(data);
481 	ack_APIC_irq();
482 }
483 
484 static int apic_set_affinity(struct irq_data *irq_data,
485 			     const struct cpumask *dest, bool force)
486 {
487 	struct apic_chip_data *data = irq_data->chip_data;
488 	int err, irq = irq_data->irq;
489 
490 	if (!config_enabled(CONFIG_SMP))
491 		return -EPERM;
492 
493 	if (!cpumask_intersects(dest, cpu_online_mask))
494 		return -EINVAL;
495 
496 	err = assign_irq_vector(irq, data, dest);
497 	if (err) {
498 		if (assign_irq_vector(irq, data,
499 				      irq_data_get_affinity_mask(irq_data)))
500 			pr_err("Failed to recover vector for irq %d\n", irq);
501 		return err;
502 	}
503 
504 	return IRQ_SET_MASK_OK;
505 }
506 
507 static struct irq_chip lapic_controller = {
508 	.irq_ack		= apic_ack_edge,
509 	.irq_set_affinity	= apic_set_affinity,
510 	.irq_retrigger		= apic_retrigger_irq,
511 };
512 
513 #ifdef CONFIG_SMP
514 static void __send_cleanup_vector(struct apic_chip_data *data)
515 {
516 	cpumask_var_t cleanup_mask;
517 
518 	if (unlikely(!alloc_cpumask_var(&cleanup_mask, GFP_ATOMIC))) {
519 		unsigned int i;
520 
521 		for_each_cpu_and(i, data->old_domain, cpu_online_mask)
522 			apic->send_IPI_mask(cpumask_of(i),
523 					    IRQ_MOVE_CLEANUP_VECTOR);
524 	} else {
525 		cpumask_and(cleanup_mask, data->old_domain, cpu_online_mask);
526 		apic->send_IPI_mask(cleanup_mask, IRQ_MOVE_CLEANUP_VECTOR);
527 		free_cpumask_var(cleanup_mask);
528 	}
529 	data->move_in_progress = 0;
530 }
531 
532 void send_cleanup_vector(struct irq_cfg *cfg)
533 {
534 	struct apic_chip_data *data;
535 
536 	data = container_of(cfg, struct apic_chip_data, cfg);
537 	if (data->move_in_progress)
538 		__send_cleanup_vector(data);
539 }
540 
541 asmlinkage __visible void smp_irq_move_cleanup_interrupt(void)
542 {
543 	unsigned vector, me;
544 
545 	entering_ack_irq();
546 
547 	/* Prevent vectors vanishing under us */
548 	raw_spin_lock(&vector_lock);
549 
550 	me = smp_processor_id();
551 	for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
552 		struct apic_chip_data *data;
553 		struct irq_desc *desc;
554 		unsigned int irr;
555 
556 	retry:
557 		desc = __this_cpu_read(vector_irq[vector]);
558 		if (IS_ERR_OR_NULL(desc))
559 			continue;
560 
561 		if (!raw_spin_trylock(&desc->lock)) {
562 			raw_spin_unlock(&vector_lock);
563 			cpu_relax();
564 			raw_spin_lock(&vector_lock);
565 			goto retry;
566 		}
567 
568 		data = apic_chip_data(irq_desc_get_irq_data(desc));
569 		if (!data)
570 			goto unlock;
571 
572 		/*
573 		 * Check if the irq migration is in progress. If so, we
574 		 * haven't received the cleanup request yet for this irq.
575 		 */
576 		if (data->move_in_progress)
577 			goto unlock;
578 
579 		if (vector == data->cfg.vector &&
580 		    cpumask_test_cpu(me, data->domain))
581 			goto unlock;
582 
583 		irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
584 		/*
585 		 * Check if the vector that needs to be cleanedup is
586 		 * registered at the cpu's IRR. If so, then this is not
587 		 * the best time to clean it up. Lets clean it up in the
588 		 * next attempt by sending another IRQ_MOVE_CLEANUP_VECTOR
589 		 * to myself.
590 		 */
591 		if (irr  & (1 << (vector % 32))) {
592 			apic->send_IPI_self(IRQ_MOVE_CLEANUP_VECTOR);
593 			goto unlock;
594 		}
595 		__this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
596 unlock:
597 		raw_spin_unlock(&desc->lock);
598 	}
599 
600 	raw_spin_unlock(&vector_lock);
601 
602 	exiting_irq();
603 }
604 
605 static void __irq_complete_move(struct irq_cfg *cfg, unsigned vector)
606 {
607 	unsigned me;
608 	struct apic_chip_data *data;
609 
610 	data = container_of(cfg, struct apic_chip_data, cfg);
611 	if (likely(!data->move_in_progress))
612 		return;
613 
614 	me = smp_processor_id();
615 	if (vector == data->cfg.vector && cpumask_test_cpu(me, data->domain))
616 		__send_cleanup_vector(data);
617 }
618 
619 void irq_complete_move(struct irq_cfg *cfg)
620 {
621 	__irq_complete_move(cfg, ~get_irq_regs()->orig_ax);
622 }
623 
624 void irq_force_complete_move(int irq)
625 {
626 	struct irq_cfg *cfg = irq_cfg(irq);
627 
628 	if (cfg)
629 		__irq_complete_move(cfg, cfg->vector);
630 }
631 #endif
632 
633 static void __init print_APIC_field(int base)
634 {
635 	int i;
636 
637 	printk(KERN_DEBUG);
638 
639 	for (i = 0; i < 8; i++)
640 		pr_cont("%08x", apic_read(base + i*0x10));
641 
642 	pr_cont("\n");
643 }
644 
645 static void __init print_local_APIC(void *dummy)
646 {
647 	unsigned int i, v, ver, maxlvt;
648 	u64 icr;
649 
650 	pr_debug("printing local APIC contents on CPU#%d/%d:\n",
651 		 smp_processor_id(), hard_smp_processor_id());
652 	v = apic_read(APIC_ID);
653 	pr_info("... APIC ID:      %08x (%01x)\n", v, read_apic_id());
654 	v = apic_read(APIC_LVR);
655 	pr_info("... APIC VERSION: %08x\n", v);
656 	ver = GET_APIC_VERSION(v);
657 	maxlvt = lapic_get_maxlvt();
658 
659 	v = apic_read(APIC_TASKPRI);
660 	pr_debug("... APIC TASKPRI: %08x (%02x)\n", v, v & APIC_TPRI_MASK);
661 
662 	/* !82489DX */
663 	if (APIC_INTEGRATED(ver)) {
664 		if (!APIC_XAPIC(ver)) {
665 			v = apic_read(APIC_ARBPRI);
666 			pr_debug("... APIC ARBPRI: %08x (%02x)\n",
667 				 v, v & APIC_ARBPRI_MASK);
668 		}
669 		v = apic_read(APIC_PROCPRI);
670 		pr_debug("... APIC PROCPRI: %08x\n", v);
671 	}
672 
673 	/*
674 	 * Remote read supported only in the 82489DX and local APIC for
675 	 * Pentium processors.
676 	 */
677 	if (!APIC_INTEGRATED(ver) || maxlvt == 3) {
678 		v = apic_read(APIC_RRR);
679 		pr_debug("... APIC RRR: %08x\n", v);
680 	}
681 
682 	v = apic_read(APIC_LDR);
683 	pr_debug("... APIC LDR: %08x\n", v);
684 	if (!x2apic_enabled()) {
685 		v = apic_read(APIC_DFR);
686 		pr_debug("... APIC DFR: %08x\n", v);
687 	}
688 	v = apic_read(APIC_SPIV);
689 	pr_debug("... APIC SPIV: %08x\n", v);
690 
691 	pr_debug("... APIC ISR field:\n");
692 	print_APIC_field(APIC_ISR);
693 	pr_debug("... APIC TMR field:\n");
694 	print_APIC_field(APIC_TMR);
695 	pr_debug("... APIC IRR field:\n");
696 	print_APIC_field(APIC_IRR);
697 
698 	/* !82489DX */
699 	if (APIC_INTEGRATED(ver)) {
700 		/* Due to the Pentium erratum 3AP. */
701 		if (maxlvt > 3)
702 			apic_write(APIC_ESR, 0);
703 
704 		v = apic_read(APIC_ESR);
705 		pr_debug("... APIC ESR: %08x\n", v);
706 	}
707 
708 	icr = apic_icr_read();
709 	pr_debug("... APIC ICR: %08x\n", (u32)icr);
710 	pr_debug("... APIC ICR2: %08x\n", (u32)(icr >> 32));
711 
712 	v = apic_read(APIC_LVTT);
713 	pr_debug("... APIC LVTT: %08x\n", v);
714 
715 	if (maxlvt > 3) {
716 		/* PC is LVT#4. */
717 		v = apic_read(APIC_LVTPC);
718 		pr_debug("... APIC LVTPC: %08x\n", v);
719 	}
720 	v = apic_read(APIC_LVT0);
721 	pr_debug("... APIC LVT0: %08x\n", v);
722 	v = apic_read(APIC_LVT1);
723 	pr_debug("... APIC LVT1: %08x\n", v);
724 
725 	if (maxlvt > 2) {
726 		/* ERR is LVT#3. */
727 		v = apic_read(APIC_LVTERR);
728 		pr_debug("... APIC LVTERR: %08x\n", v);
729 	}
730 
731 	v = apic_read(APIC_TMICT);
732 	pr_debug("... APIC TMICT: %08x\n", v);
733 	v = apic_read(APIC_TMCCT);
734 	pr_debug("... APIC TMCCT: %08x\n", v);
735 	v = apic_read(APIC_TDCR);
736 	pr_debug("... APIC TDCR: %08x\n", v);
737 
738 	if (boot_cpu_has(X86_FEATURE_EXTAPIC)) {
739 		v = apic_read(APIC_EFEAT);
740 		maxlvt = (v >> 16) & 0xff;
741 		pr_debug("... APIC EFEAT: %08x\n", v);
742 		v = apic_read(APIC_ECTRL);
743 		pr_debug("... APIC ECTRL: %08x\n", v);
744 		for (i = 0; i < maxlvt; i++) {
745 			v = apic_read(APIC_EILVTn(i));
746 			pr_debug("... APIC EILVT%d: %08x\n", i, v);
747 		}
748 	}
749 	pr_cont("\n");
750 }
751 
752 static void __init print_local_APICs(int maxcpu)
753 {
754 	int cpu;
755 
756 	if (!maxcpu)
757 		return;
758 
759 	preempt_disable();
760 	for_each_online_cpu(cpu) {
761 		if (cpu >= maxcpu)
762 			break;
763 		smp_call_function_single(cpu, print_local_APIC, NULL, 1);
764 	}
765 	preempt_enable();
766 }
767 
768 static void __init print_PIC(void)
769 {
770 	unsigned int v;
771 	unsigned long flags;
772 
773 	if (!nr_legacy_irqs())
774 		return;
775 
776 	pr_debug("\nprinting PIC contents\n");
777 
778 	raw_spin_lock_irqsave(&i8259A_lock, flags);
779 
780 	v = inb(0xa1) << 8 | inb(0x21);
781 	pr_debug("... PIC  IMR: %04x\n", v);
782 
783 	v = inb(0xa0) << 8 | inb(0x20);
784 	pr_debug("... PIC  IRR: %04x\n", v);
785 
786 	outb(0x0b, 0xa0);
787 	outb(0x0b, 0x20);
788 	v = inb(0xa0) << 8 | inb(0x20);
789 	outb(0x0a, 0xa0);
790 	outb(0x0a, 0x20);
791 
792 	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
793 
794 	pr_debug("... PIC  ISR: %04x\n", v);
795 
796 	v = inb(0x4d1) << 8 | inb(0x4d0);
797 	pr_debug("... PIC ELCR: %04x\n", v);
798 }
799 
800 static int show_lapic __initdata = 1;
801 static __init int setup_show_lapic(char *arg)
802 {
803 	int num = -1;
804 
805 	if (strcmp(arg, "all") == 0) {
806 		show_lapic = CONFIG_NR_CPUS;
807 	} else {
808 		get_option(&arg, &num);
809 		if (num >= 0)
810 			show_lapic = num;
811 	}
812 
813 	return 1;
814 }
815 __setup("show_lapic=", setup_show_lapic);
816 
817 static int __init print_ICs(void)
818 {
819 	if (apic_verbosity == APIC_QUIET)
820 		return 0;
821 
822 	print_PIC();
823 
824 	/* don't print out if apic is not there */
825 	if (!cpu_has_apic && !apic_from_smp_config())
826 		return 0;
827 
828 	print_local_APICs(show_lapic);
829 	print_IO_APICs();
830 
831 	return 0;
832 }
833 
834 late_initcall(print_ICs);
835