xref: /linux/arch/x86/kernel/apic/vector.c (revision fbce3befd60d40639bf3c6b60f7477b2f988f92d)
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, vector_searchmask, searched_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, vector;
122 
123 	/*
124 	 * If there is still a move in progress or the previous move has not
125 	 * been cleaned up completely, tell the caller to come back later.
126 	 */
127 	if (d->move_in_progress ||
128 	    cpumask_intersects(d->old_domain, cpu_online_mask))
129 		return -EBUSY;
130 
131 	/* Only try and allocate irqs on cpus that are present */
132 	cpumask_clear(d->old_domain);
133 	cpumask_clear(searched_cpumask);
134 	cpu = cpumask_first_and(mask, cpu_online_mask);
135 	while (cpu < nr_cpu_ids) {
136 		int new_cpu, offset;
137 
138 		/* Get the possible target cpus for @mask/@cpu from the apic */
139 		apic->vector_allocation_domain(cpu, vector_cpumask, mask);
140 
141 		/*
142 		 * Clear the offline cpus from @vector_cpumask for searching
143 		 * and verify whether the result overlaps with @mask. If true,
144 		 * then the call to apic->cpu_mask_to_apicid_and() will
145 		 * succeed as well. If not, no point in trying to find a
146 		 * vector in this mask.
147 		 */
148 		cpumask_and(vector_searchmask, vector_cpumask, cpu_online_mask);
149 		if (!cpumask_intersects(vector_searchmask, mask))
150 			goto next_cpu;
151 
152 		if (cpumask_subset(vector_cpumask, d->domain)) {
153 			if (cpumask_equal(vector_cpumask, d->domain))
154 				goto success;
155 			/*
156 			 * Mark the cpus which are not longer in the mask for
157 			 * cleanup.
158 			 */
159 			cpumask_andnot(d->old_domain, d->domain, vector_cpumask);
160 			vector = d->cfg.vector;
161 			goto update;
162 		}
163 
164 		vector = current_vector;
165 		offset = current_offset;
166 next:
167 		vector += 16;
168 		if (vector >= first_system_vector) {
169 			offset = (offset + 1) % 16;
170 			vector = FIRST_EXTERNAL_VECTOR + offset;
171 		}
172 
173 		/* If the search wrapped around, try the next cpu */
174 		if (unlikely(current_vector == vector))
175 			goto next_cpu;
176 
177 		if (test_bit(vector, used_vectors))
178 			goto next;
179 
180 		for_each_cpu(new_cpu, vector_searchmask) {
181 			if (!IS_ERR_OR_NULL(per_cpu(vector_irq, new_cpu)[vector]))
182 				goto next;
183 		}
184 		/* Found one! */
185 		current_vector = vector;
186 		current_offset = offset;
187 		/* Schedule the old vector for cleanup on all cpus */
188 		if (d->cfg.vector)
189 			cpumask_copy(d->old_domain, d->domain);
190 		for_each_cpu(new_cpu, vector_searchmask)
191 			per_cpu(vector_irq, new_cpu)[vector] = irq_to_desc(irq);
192 		goto update;
193 
194 next_cpu:
195 		/*
196 		 * We exclude the current @vector_cpumask from the requested
197 		 * @mask and try again with the next online cpu in the
198 		 * result. We cannot modify @mask, so we use @vector_cpumask
199 		 * as a temporary buffer here as it will be reassigned when
200 		 * calling apic->vector_allocation_domain() above.
201 		 */
202 		cpumask_or(searched_cpumask, searched_cpumask, vector_cpumask);
203 		cpumask_andnot(vector_cpumask, mask, searched_cpumask);
204 		cpu = cpumask_first_and(vector_cpumask, cpu_online_mask);
205 		continue;
206 	}
207 	return -ENOSPC;
208 
209 update:
210 	/*
211 	 * Exclude offline cpus from the cleanup mask and set the
212 	 * move_in_progress flag when the result is not empty.
213 	 */
214 	cpumask_and(d->old_domain, d->old_domain, cpu_online_mask);
215 	d->move_in_progress = !cpumask_empty(d->old_domain);
216 	d->cfg.old_vector = d->move_in_progress ? d->cfg.vector : 0;
217 	d->cfg.vector = vector;
218 	cpumask_copy(d->domain, vector_cpumask);
219 success:
220 	/*
221 	 * Cache destination APIC IDs into cfg->dest_apicid. This cannot fail
222 	 * as we already established, that mask & d->domain & cpu_online_mask
223 	 * is not empty.
224 	 */
225 	BUG_ON(apic->cpu_mask_to_apicid_and(mask, d->domain,
226 					    &d->cfg.dest_apicid));
227 	return 0;
228 }
229 
230 static int assign_irq_vector(int irq, struct apic_chip_data *data,
231 			     const struct cpumask *mask)
232 {
233 	int err;
234 	unsigned long flags;
235 
236 	raw_spin_lock_irqsave(&vector_lock, flags);
237 	err = __assign_irq_vector(irq, data, mask);
238 	raw_spin_unlock_irqrestore(&vector_lock, flags);
239 	return err;
240 }
241 
242 static int assign_irq_vector_policy(int irq, int node,
243 				    struct apic_chip_data *data,
244 				    struct irq_alloc_info *info)
245 {
246 	if (info && info->mask)
247 		return assign_irq_vector(irq, data, info->mask);
248 	if (node != NUMA_NO_NODE &&
249 	    assign_irq_vector(irq, data, cpumask_of_node(node)) == 0)
250 		return 0;
251 	return assign_irq_vector(irq, data, apic->target_cpus());
252 }
253 
254 static void clear_irq_vector(int irq, struct apic_chip_data *data)
255 {
256 	struct irq_desc *desc;
257 	int cpu, vector;
258 
259 	if (!data->cfg.vector)
260 		return;
261 
262 	vector = data->cfg.vector;
263 	for_each_cpu_and(cpu, data->domain, cpu_online_mask)
264 		per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED;
265 
266 	data->cfg.vector = 0;
267 	cpumask_clear(data->domain);
268 
269 	/*
270 	 * If move is in progress or the old_domain mask is not empty,
271 	 * i.e. the cleanup IPI has not been processed yet, we need to remove
272 	 * the old references to desc from all cpus vector tables.
273 	 */
274 	if (!data->move_in_progress && cpumask_empty(data->old_domain))
275 		return;
276 
277 	desc = irq_to_desc(irq);
278 	for_each_cpu_and(cpu, data->old_domain, cpu_online_mask) {
279 		for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS;
280 		     vector++) {
281 			if (per_cpu(vector_irq, cpu)[vector] != desc)
282 				continue;
283 			per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED;
284 			break;
285 		}
286 	}
287 	data->move_in_progress = 0;
288 }
289 
290 void init_irq_alloc_info(struct irq_alloc_info *info,
291 			 const struct cpumask *mask)
292 {
293 	memset(info, 0, sizeof(*info));
294 	info->mask = mask;
295 }
296 
297 void copy_irq_alloc_info(struct irq_alloc_info *dst, struct irq_alloc_info *src)
298 {
299 	if (src)
300 		*dst = *src;
301 	else
302 		memset(dst, 0, sizeof(*dst));
303 }
304 
305 static void x86_vector_free_irqs(struct irq_domain *domain,
306 				 unsigned int virq, unsigned int nr_irqs)
307 {
308 	struct apic_chip_data *apic_data;
309 	struct irq_data *irq_data;
310 	unsigned long flags;
311 	int i;
312 
313 	for (i = 0; i < nr_irqs; i++) {
314 		irq_data = irq_domain_get_irq_data(x86_vector_domain, virq + i);
315 		if (irq_data && irq_data->chip_data) {
316 			raw_spin_lock_irqsave(&vector_lock, flags);
317 			clear_irq_vector(virq + i, irq_data->chip_data);
318 			apic_data = irq_data->chip_data;
319 			irq_domain_reset_irq_data(irq_data);
320 			raw_spin_unlock_irqrestore(&vector_lock, flags);
321 			free_apic_chip_data(apic_data);
322 #ifdef	CONFIG_X86_IO_APIC
323 			if (virq + i < nr_legacy_irqs())
324 				legacy_irq_data[virq + i] = NULL;
325 #endif
326 		}
327 	}
328 }
329 
330 static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq,
331 				 unsigned int nr_irqs, void *arg)
332 {
333 	struct irq_alloc_info *info = arg;
334 	struct apic_chip_data *data;
335 	struct irq_data *irq_data;
336 	int i, err, node;
337 
338 	if (disable_apic)
339 		return -ENXIO;
340 
341 	/* Currently vector allocator can't guarantee contiguous allocations */
342 	if ((info->flags & X86_IRQ_ALLOC_CONTIGUOUS_VECTORS) && nr_irqs > 1)
343 		return -ENOSYS;
344 
345 	for (i = 0; i < nr_irqs; i++) {
346 		irq_data = irq_domain_get_irq_data(domain, virq + i);
347 		BUG_ON(!irq_data);
348 		node = irq_data_get_node(irq_data);
349 #ifdef	CONFIG_X86_IO_APIC
350 		if (virq + i < nr_legacy_irqs() && legacy_irq_data[virq + i])
351 			data = legacy_irq_data[virq + i];
352 		else
353 #endif
354 			data = alloc_apic_chip_data(node);
355 		if (!data) {
356 			err = -ENOMEM;
357 			goto error;
358 		}
359 
360 		irq_data->chip = &lapic_controller;
361 		irq_data->chip_data = data;
362 		irq_data->hwirq = virq + i;
363 		err = assign_irq_vector_policy(virq + i, node, data, info);
364 		if (err)
365 			goto error;
366 	}
367 
368 	return 0;
369 
370 error:
371 	x86_vector_free_irqs(domain, virq, i + 1);
372 	return err;
373 }
374 
375 static const struct irq_domain_ops x86_vector_domain_ops = {
376 	.alloc	= x86_vector_alloc_irqs,
377 	.free	= x86_vector_free_irqs,
378 };
379 
380 int __init arch_probe_nr_irqs(void)
381 {
382 	int nr;
383 
384 	if (nr_irqs > (NR_VECTORS * nr_cpu_ids))
385 		nr_irqs = NR_VECTORS * nr_cpu_ids;
386 
387 	nr = (gsi_top + nr_legacy_irqs()) + 8 * nr_cpu_ids;
388 #if defined(CONFIG_PCI_MSI) || defined(CONFIG_HT_IRQ)
389 	/*
390 	 * for MSI and HT dyn irq
391 	 */
392 	if (gsi_top <= NR_IRQS_LEGACY)
393 		nr +=  8 * nr_cpu_ids;
394 	else
395 		nr += gsi_top * 16;
396 #endif
397 	if (nr < nr_irqs)
398 		nr_irqs = nr;
399 
400 	/*
401 	 * We don't know if PIC is present at this point so we need to do
402 	 * probe() to get the right number of legacy IRQs.
403 	 */
404 	return legacy_pic->probe();
405 }
406 
407 #ifdef	CONFIG_X86_IO_APIC
408 static void init_legacy_irqs(void)
409 {
410 	int i, node = cpu_to_node(0);
411 	struct apic_chip_data *data;
412 
413 	/*
414 	 * For legacy IRQ's, start with assigning irq0 to irq15 to
415 	 * ISA_IRQ_VECTOR(i) for all cpu's.
416 	 */
417 	for (i = 0; i < nr_legacy_irqs(); i++) {
418 		data = legacy_irq_data[i] = alloc_apic_chip_data(node);
419 		BUG_ON(!data);
420 
421 		data->cfg.vector = ISA_IRQ_VECTOR(i);
422 		cpumask_setall(data->domain);
423 		irq_set_chip_data(i, data);
424 	}
425 }
426 #else
427 static void init_legacy_irqs(void) { }
428 #endif
429 
430 int __init arch_early_irq_init(void)
431 {
432 	init_legacy_irqs();
433 
434 	x86_vector_domain = irq_domain_add_tree(NULL, &x86_vector_domain_ops,
435 						NULL);
436 	BUG_ON(x86_vector_domain == NULL);
437 	irq_set_default_host(x86_vector_domain);
438 
439 	arch_init_msi_domain(x86_vector_domain);
440 	arch_init_htirq_domain(x86_vector_domain);
441 
442 	BUG_ON(!alloc_cpumask_var(&vector_cpumask, GFP_KERNEL));
443 	BUG_ON(!alloc_cpumask_var(&vector_searchmask, GFP_KERNEL));
444 	BUG_ON(!alloc_cpumask_var(&searched_cpumask, GFP_KERNEL));
445 
446 	return arch_early_ioapic_init();
447 }
448 
449 /* Initialize vector_irq on a new cpu */
450 static void __setup_vector_irq(int cpu)
451 {
452 	struct apic_chip_data *data;
453 	struct irq_desc *desc;
454 	int irq, vector;
455 
456 	/* Mark the inuse vectors */
457 	for_each_irq_desc(irq, desc) {
458 		struct irq_data *idata = irq_desc_get_irq_data(desc);
459 
460 		data = apic_chip_data(idata);
461 		if (!data || !cpumask_test_cpu(cpu, data->domain))
462 			continue;
463 		vector = data->cfg.vector;
464 		per_cpu(vector_irq, cpu)[vector] = desc;
465 	}
466 	/* Mark the free vectors */
467 	for (vector = 0; vector < NR_VECTORS; ++vector) {
468 		desc = per_cpu(vector_irq, cpu)[vector];
469 		if (IS_ERR_OR_NULL(desc))
470 			continue;
471 
472 		data = apic_chip_data(irq_desc_get_irq_data(desc));
473 		if (!cpumask_test_cpu(cpu, data->domain))
474 			per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED;
475 	}
476 }
477 
478 /*
479  * Setup the vector to irq mappings. Must be called with vector_lock held.
480  */
481 void setup_vector_irq(int cpu)
482 {
483 	int irq;
484 
485 	lockdep_assert_held(&vector_lock);
486 	/*
487 	 * On most of the platforms, legacy PIC delivers the interrupts on the
488 	 * boot cpu. But there are certain platforms where PIC interrupts are
489 	 * delivered to multiple cpu's. If the legacy IRQ is handled by the
490 	 * legacy PIC, for the new cpu that is coming online, setup the static
491 	 * legacy vector to irq mapping:
492 	 */
493 	for (irq = 0; irq < nr_legacy_irqs(); irq++)
494 		per_cpu(vector_irq, cpu)[ISA_IRQ_VECTOR(irq)] = irq_to_desc(irq);
495 
496 	__setup_vector_irq(cpu);
497 }
498 
499 static int apic_retrigger_irq(struct irq_data *irq_data)
500 {
501 	struct apic_chip_data *data = apic_chip_data(irq_data);
502 	unsigned long flags;
503 	int cpu;
504 
505 	raw_spin_lock_irqsave(&vector_lock, flags);
506 	cpu = cpumask_first_and(data->domain, cpu_online_mask);
507 	apic->send_IPI_mask(cpumask_of(cpu), data->cfg.vector);
508 	raw_spin_unlock_irqrestore(&vector_lock, flags);
509 
510 	return 1;
511 }
512 
513 void apic_ack_edge(struct irq_data *data)
514 {
515 	irq_complete_move(irqd_cfg(data));
516 	irq_move_irq(data);
517 	ack_APIC_irq();
518 }
519 
520 static int apic_set_affinity(struct irq_data *irq_data,
521 			     const struct cpumask *dest, bool force)
522 {
523 	struct apic_chip_data *data = irq_data->chip_data;
524 	int err, irq = irq_data->irq;
525 
526 	if (!config_enabled(CONFIG_SMP))
527 		return -EPERM;
528 
529 	if (!cpumask_intersects(dest, cpu_online_mask))
530 		return -EINVAL;
531 
532 	err = assign_irq_vector(irq, data, dest);
533 	return err ? err : IRQ_SET_MASK_OK;
534 }
535 
536 static struct irq_chip lapic_controller = {
537 	.irq_ack		= apic_ack_edge,
538 	.irq_set_affinity	= apic_set_affinity,
539 	.irq_retrigger		= apic_retrigger_irq,
540 };
541 
542 #ifdef CONFIG_SMP
543 static void __send_cleanup_vector(struct apic_chip_data *data)
544 {
545 	raw_spin_lock(&vector_lock);
546 	cpumask_and(data->old_domain, data->old_domain, cpu_online_mask);
547 	data->move_in_progress = 0;
548 	if (!cpumask_empty(data->old_domain))
549 		apic->send_IPI_mask(data->old_domain, IRQ_MOVE_CLEANUP_VECTOR);
550 	raw_spin_unlock(&vector_lock);
551 }
552 
553 void send_cleanup_vector(struct irq_cfg *cfg)
554 {
555 	struct apic_chip_data *data;
556 
557 	data = container_of(cfg, struct apic_chip_data, cfg);
558 	if (data->move_in_progress)
559 		__send_cleanup_vector(data);
560 }
561 
562 asmlinkage __visible void smp_irq_move_cleanup_interrupt(void)
563 {
564 	unsigned vector, me;
565 
566 	entering_ack_irq();
567 
568 	/* Prevent vectors vanishing under us */
569 	raw_spin_lock(&vector_lock);
570 
571 	me = smp_processor_id();
572 	for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
573 		struct apic_chip_data *data;
574 		struct irq_desc *desc;
575 		unsigned int irr;
576 
577 	retry:
578 		desc = __this_cpu_read(vector_irq[vector]);
579 		if (IS_ERR_OR_NULL(desc))
580 			continue;
581 
582 		if (!raw_spin_trylock(&desc->lock)) {
583 			raw_spin_unlock(&vector_lock);
584 			cpu_relax();
585 			raw_spin_lock(&vector_lock);
586 			goto retry;
587 		}
588 
589 		data = apic_chip_data(irq_desc_get_irq_data(desc));
590 		if (!data)
591 			goto unlock;
592 
593 		/*
594 		 * Nothing to cleanup if irq migration is in progress
595 		 * or this cpu is not set in the cleanup mask.
596 		 */
597 		if (data->move_in_progress ||
598 		    !cpumask_test_cpu(me, data->old_domain))
599 			goto unlock;
600 
601 		/*
602 		 * We have two cases to handle here:
603 		 * 1) vector is unchanged but the target mask got reduced
604 		 * 2) vector and the target mask has changed
605 		 *
606 		 * #1 is obvious, but in #2 we have two vectors with the same
607 		 * irq descriptor: the old and the new vector. So we need to
608 		 * make sure that we only cleanup the old vector. The new
609 		 * vector has the current @vector number in the config and
610 		 * this cpu is part of the target mask. We better leave that
611 		 * one alone.
612 		 */
613 		if (vector == data->cfg.vector &&
614 		    cpumask_test_cpu(me, data->domain))
615 			goto unlock;
616 
617 		irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
618 		/*
619 		 * Check if the vector that needs to be cleanedup is
620 		 * registered at the cpu's IRR. If so, then this is not
621 		 * the best time to clean it up. Lets clean it up in the
622 		 * next attempt by sending another IRQ_MOVE_CLEANUP_VECTOR
623 		 * to myself.
624 		 */
625 		if (irr  & (1 << (vector % 32))) {
626 			apic->send_IPI_self(IRQ_MOVE_CLEANUP_VECTOR);
627 			goto unlock;
628 		}
629 		__this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
630 		cpumask_clear_cpu(me, data->old_domain);
631 unlock:
632 		raw_spin_unlock(&desc->lock);
633 	}
634 
635 	raw_spin_unlock(&vector_lock);
636 
637 	exiting_irq();
638 }
639 
640 static void __irq_complete_move(struct irq_cfg *cfg, unsigned vector)
641 {
642 	unsigned me;
643 	struct apic_chip_data *data;
644 
645 	data = container_of(cfg, struct apic_chip_data, cfg);
646 	if (likely(!data->move_in_progress))
647 		return;
648 
649 	me = smp_processor_id();
650 	if (vector == data->cfg.vector && cpumask_test_cpu(me, data->domain))
651 		__send_cleanup_vector(data);
652 }
653 
654 void irq_complete_move(struct irq_cfg *cfg)
655 {
656 	__irq_complete_move(cfg, ~get_irq_regs()->orig_ax);
657 }
658 
659 /*
660  * Called from fixup_irqs() with @desc->lock held and interrupts disabled.
661  */
662 void irq_force_complete_move(struct irq_desc *desc)
663 {
664 	struct irq_data *irqdata = irq_desc_get_irq_data(desc);
665 	struct apic_chip_data *data = apic_chip_data(irqdata);
666 	struct irq_cfg *cfg = data ? &data->cfg : NULL;
667 	unsigned int cpu;
668 
669 	if (!cfg)
670 		return;
671 
672 	/*
673 	 * This is tricky. If the cleanup of @data->old_domain has not been
674 	 * done yet, then the following setaffinity call will fail with
675 	 * -EBUSY. This can leave the interrupt in a stale state.
676 	 *
677 	 * All CPUs are stuck in stop machine with interrupts disabled so
678 	 * calling __irq_complete_move() would be completely pointless.
679 	 */
680 	raw_spin_lock(&vector_lock);
681 	/*
682 	 * Clean out all offline cpus (including the outgoing one) from the
683 	 * old_domain mask.
684 	 */
685 	cpumask_and(data->old_domain, data->old_domain, cpu_online_mask);
686 
687 	/*
688 	 * If move_in_progress is cleared and the old_domain mask is empty,
689 	 * then there is nothing to cleanup. fixup_irqs() will take care of
690 	 * the stale vectors on the outgoing cpu.
691 	 */
692 	if (!data->move_in_progress && cpumask_empty(data->old_domain)) {
693 		raw_spin_unlock(&vector_lock);
694 		return;
695 	}
696 
697 	/*
698 	 * 1) The interrupt is in move_in_progress state. That means that we
699 	 *    have not seen an interrupt since the io_apic was reprogrammed to
700 	 *    the new vector.
701 	 *
702 	 * 2) The interrupt has fired on the new vector, but the cleanup IPIs
703 	 *    have not been processed yet.
704 	 */
705 	if (data->move_in_progress) {
706 		/*
707 		 * In theory there is a race:
708 		 *
709 		 * set_ioapic(new_vector) <-- Interrupt is raised before update
710 		 *			      is effective, i.e. it's raised on
711 		 *			      the old vector.
712 		 *
713 		 * So if the target cpu cannot handle that interrupt before
714 		 * the old vector is cleaned up, we get a spurious interrupt
715 		 * and in the worst case the ioapic irq line becomes stale.
716 		 *
717 		 * But in case of cpu hotplug this should be a non issue
718 		 * because if the affinity update happens right before all
719 		 * cpus rendevouz in stop machine, there is no way that the
720 		 * interrupt can be blocked on the target cpu because all cpus
721 		 * loops first with interrupts enabled in stop machine, so the
722 		 * old vector is not yet cleaned up when the interrupt fires.
723 		 *
724 		 * So the only way to run into this issue is if the delivery
725 		 * of the interrupt on the apic/system bus would be delayed
726 		 * beyond the point where the target cpu disables interrupts
727 		 * in stop machine. I doubt that it can happen, but at least
728 		 * there is a theroretical chance. Virtualization might be
729 		 * able to expose this, but AFAICT the IOAPIC emulation is not
730 		 * as stupid as the real hardware.
731 		 *
732 		 * Anyway, there is nothing we can do about that at this point
733 		 * w/o refactoring the whole fixup_irq() business completely.
734 		 * We print at least the irq number and the old vector number,
735 		 * so we have the necessary information when a problem in that
736 		 * area arises.
737 		 */
738 		pr_warn("IRQ fixup: irq %d move in progress, old vector %d\n",
739 			irqdata->irq, cfg->old_vector);
740 	}
741 	/*
742 	 * If old_domain is not empty, then other cpus still have the irq
743 	 * descriptor set in their vector array. Clean it up.
744 	 */
745 	for_each_cpu(cpu, data->old_domain)
746 		per_cpu(vector_irq, cpu)[cfg->old_vector] = VECTOR_UNUSED;
747 
748 	/* Cleanup the left overs of the (half finished) move */
749 	cpumask_clear(data->old_domain);
750 	data->move_in_progress = 0;
751 	raw_spin_unlock(&vector_lock);
752 }
753 #endif
754 
755 static void __init print_APIC_field(int base)
756 {
757 	int i;
758 
759 	printk(KERN_DEBUG);
760 
761 	for (i = 0; i < 8; i++)
762 		pr_cont("%08x", apic_read(base + i*0x10));
763 
764 	pr_cont("\n");
765 }
766 
767 static void __init print_local_APIC(void *dummy)
768 {
769 	unsigned int i, v, ver, maxlvt;
770 	u64 icr;
771 
772 	pr_debug("printing local APIC contents on CPU#%d/%d:\n",
773 		 smp_processor_id(), hard_smp_processor_id());
774 	v = apic_read(APIC_ID);
775 	pr_info("... APIC ID:      %08x (%01x)\n", v, read_apic_id());
776 	v = apic_read(APIC_LVR);
777 	pr_info("... APIC VERSION: %08x\n", v);
778 	ver = GET_APIC_VERSION(v);
779 	maxlvt = lapic_get_maxlvt();
780 
781 	v = apic_read(APIC_TASKPRI);
782 	pr_debug("... APIC TASKPRI: %08x (%02x)\n", v, v & APIC_TPRI_MASK);
783 
784 	/* !82489DX */
785 	if (APIC_INTEGRATED(ver)) {
786 		if (!APIC_XAPIC(ver)) {
787 			v = apic_read(APIC_ARBPRI);
788 			pr_debug("... APIC ARBPRI: %08x (%02x)\n",
789 				 v, v & APIC_ARBPRI_MASK);
790 		}
791 		v = apic_read(APIC_PROCPRI);
792 		pr_debug("... APIC PROCPRI: %08x\n", v);
793 	}
794 
795 	/*
796 	 * Remote read supported only in the 82489DX and local APIC for
797 	 * Pentium processors.
798 	 */
799 	if (!APIC_INTEGRATED(ver) || maxlvt == 3) {
800 		v = apic_read(APIC_RRR);
801 		pr_debug("... APIC RRR: %08x\n", v);
802 	}
803 
804 	v = apic_read(APIC_LDR);
805 	pr_debug("... APIC LDR: %08x\n", v);
806 	if (!x2apic_enabled()) {
807 		v = apic_read(APIC_DFR);
808 		pr_debug("... APIC DFR: %08x\n", v);
809 	}
810 	v = apic_read(APIC_SPIV);
811 	pr_debug("... APIC SPIV: %08x\n", v);
812 
813 	pr_debug("... APIC ISR field:\n");
814 	print_APIC_field(APIC_ISR);
815 	pr_debug("... APIC TMR field:\n");
816 	print_APIC_field(APIC_TMR);
817 	pr_debug("... APIC IRR field:\n");
818 	print_APIC_field(APIC_IRR);
819 
820 	/* !82489DX */
821 	if (APIC_INTEGRATED(ver)) {
822 		/* Due to the Pentium erratum 3AP. */
823 		if (maxlvt > 3)
824 			apic_write(APIC_ESR, 0);
825 
826 		v = apic_read(APIC_ESR);
827 		pr_debug("... APIC ESR: %08x\n", v);
828 	}
829 
830 	icr = apic_icr_read();
831 	pr_debug("... APIC ICR: %08x\n", (u32)icr);
832 	pr_debug("... APIC ICR2: %08x\n", (u32)(icr >> 32));
833 
834 	v = apic_read(APIC_LVTT);
835 	pr_debug("... APIC LVTT: %08x\n", v);
836 
837 	if (maxlvt > 3) {
838 		/* PC is LVT#4. */
839 		v = apic_read(APIC_LVTPC);
840 		pr_debug("... APIC LVTPC: %08x\n", v);
841 	}
842 	v = apic_read(APIC_LVT0);
843 	pr_debug("... APIC LVT0: %08x\n", v);
844 	v = apic_read(APIC_LVT1);
845 	pr_debug("... APIC LVT1: %08x\n", v);
846 
847 	if (maxlvt > 2) {
848 		/* ERR is LVT#3. */
849 		v = apic_read(APIC_LVTERR);
850 		pr_debug("... APIC LVTERR: %08x\n", v);
851 	}
852 
853 	v = apic_read(APIC_TMICT);
854 	pr_debug("... APIC TMICT: %08x\n", v);
855 	v = apic_read(APIC_TMCCT);
856 	pr_debug("... APIC TMCCT: %08x\n", v);
857 	v = apic_read(APIC_TDCR);
858 	pr_debug("... APIC TDCR: %08x\n", v);
859 
860 	if (boot_cpu_has(X86_FEATURE_EXTAPIC)) {
861 		v = apic_read(APIC_EFEAT);
862 		maxlvt = (v >> 16) & 0xff;
863 		pr_debug("... APIC EFEAT: %08x\n", v);
864 		v = apic_read(APIC_ECTRL);
865 		pr_debug("... APIC ECTRL: %08x\n", v);
866 		for (i = 0; i < maxlvt; i++) {
867 			v = apic_read(APIC_EILVTn(i));
868 			pr_debug("... APIC EILVT%d: %08x\n", i, v);
869 		}
870 	}
871 	pr_cont("\n");
872 }
873 
874 static void __init print_local_APICs(int maxcpu)
875 {
876 	int cpu;
877 
878 	if (!maxcpu)
879 		return;
880 
881 	preempt_disable();
882 	for_each_online_cpu(cpu) {
883 		if (cpu >= maxcpu)
884 			break;
885 		smp_call_function_single(cpu, print_local_APIC, NULL, 1);
886 	}
887 	preempt_enable();
888 }
889 
890 static void __init print_PIC(void)
891 {
892 	unsigned int v;
893 	unsigned long flags;
894 
895 	if (!nr_legacy_irqs())
896 		return;
897 
898 	pr_debug("\nprinting PIC contents\n");
899 
900 	raw_spin_lock_irqsave(&i8259A_lock, flags);
901 
902 	v = inb(0xa1) << 8 | inb(0x21);
903 	pr_debug("... PIC  IMR: %04x\n", v);
904 
905 	v = inb(0xa0) << 8 | inb(0x20);
906 	pr_debug("... PIC  IRR: %04x\n", v);
907 
908 	outb(0x0b, 0xa0);
909 	outb(0x0b, 0x20);
910 	v = inb(0xa0) << 8 | inb(0x20);
911 	outb(0x0a, 0xa0);
912 	outb(0x0a, 0x20);
913 
914 	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
915 
916 	pr_debug("... PIC  ISR: %04x\n", v);
917 
918 	v = inb(0x4d1) << 8 | inb(0x4d0);
919 	pr_debug("... PIC ELCR: %04x\n", v);
920 }
921 
922 static int show_lapic __initdata = 1;
923 static __init int setup_show_lapic(char *arg)
924 {
925 	int num = -1;
926 
927 	if (strcmp(arg, "all") == 0) {
928 		show_lapic = CONFIG_NR_CPUS;
929 	} else {
930 		get_option(&arg, &num);
931 		if (num >= 0)
932 			show_lapic = num;
933 	}
934 
935 	return 1;
936 }
937 __setup("show_lapic=", setup_show_lapic);
938 
939 static int __init print_ICs(void)
940 {
941 	if (apic_verbosity == APIC_QUIET)
942 		return 0;
943 
944 	print_PIC();
945 
946 	/* don't print out if apic is not there */
947 	if (!cpu_has_apic && !apic_from_smp_config())
948 		return 0;
949 
950 	print_local_APICs(show_lapic);
951 	print_IO_APICs();
952 
953 	return 0;
954 }
955 
956 late_initcall(print_ICs);
957