xref: /openbmc/linux/arch/x86/kernel/apic/vector.c (revision 4f3db074)
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  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <linux/interrupt.h>
12 #include <linux/init.h>
13 #include <linux/compiler.h>
14 #include <linux/irqdomain.h>
15 #include <linux/slab.h>
16 #include <asm/hw_irq.h>
17 #include <asm/apic.h>
18 #include <asm/i8259.h>
19 #include <asm/desc.h>
20 #include <asm/irq_remapping.h>
21 
22 static DEFINE_RAW_SPINLOCK(vector_lock);
23 
24 void lock_vector_lock(void)
25 {
26 	/* Used to the online set of cpus does not change
27 	 * during assign_irq_vector.
28 	 */
29 	raw_spin_lock(&vector_lock);
30 }
31 
32 void unlock_vector_lock(void)
33 {
34 	raw_spin_unlock(&vector_lock);
35 }
36 
37 struct irq_cfg *irq_cfg(unsigned int irq)
38 {
39 	return irq_get_chip_data(irq);
40 }
41 
42 struct irq_cfg *irqd_cfg(struct irq_data *irq_data)
43 {
44 	return irq_data->chip_data;
45 }
46 
47 static struct irq_cfg *alloc_irq_cfg(unsigned int irq, int node)
48 {
49 	struct irq_cfg *cfg;
50 
51 	cfg = kzalloc_node(sizeof(*cfg), GFP_KERNEL, node);
52 	if (!cfg)
53 		return NULL;
54 	if (!zalloc_cpumask_var_node(&cfg->domain, GFP_KERNEL, node))
55 		goto out_cfg;
56 	if (!zalloc_cpumask_var_node(&cfg->old_domain, GFP_KERNEL, node))
57 		goto out_domain;
58 #ifdef	CONFIG_X86_IO_APIC
59 	INIT_LIST_HEAD(&cfg->irq_2_pin);
60 #endif
61 	return cfg;
62 out_domain:
63 	free_cpumask_var(cfg->domain);
64 out_cfg:
65 	kfree(cfg);
66 	return NULL;
67 }
68 
69 struct irq_cfg *alloc_irq_and_cfg_at(unsigned int at, int node)
70 {
71 	int res = irq_alloc_desc_at(at, node);
72 	struct irq_cfg *cfg;
73 
74 	if (res < 0) {
75 		if (res != -EEXIST)
76 			return NULL;
77 		cfg = irq_cfg(at);
78 		if (cfg)
79 			return cfg;
80 	}
81 
82 	cfg = alloc_irq_cfg(at, node);
83 	if (cfg)
84 		irq_set_chip_data(at, cfg);
85 	else
86 		irq_free_desc(at);
87 	return cfg;
88 }
89 
90 static void free_irq_cfg(unsigned int at, struct irq_cfg *cfg)
91 {
92 	if (!cfg)
93 		return;
94 	irq_set_chip_data(at, NULL);
95 	free_cpumask_var(cfg->domain);
96 	free_cpumask_var(cfg->old_domain);
97 	kfree(cfg);
98 }
99 
100 static int
101 __assign_irq_vector(int irq, struct irq_cfg *cfg, const struct cpumask *mask)
102 {
103 	/*
104 	 * NOTE! The local APIC isn't very good at handling
105 	 * multiple interrupts at the same interrupt level.
106 	 * As the interrupt level is determined by taking the
107 	 * vector number and shifting that right by 4, we
108 	 * want to spread these out a bit so that they don't
109 	 * all fall in the same interrupt level.
110 	 *
111 	 * Also, we've got to be careful not to trash gate
112 	 * 0x80, because int 0x80 is hm, kind of importantish. ;)
113 	 */
114 	static int current_vector = FIRST_EXTERNAL_VECTOR + VECTOR_OFFSET_START;
115 	static int current_offset = VECTOR_OFFSET_START % 16;
116 	int cpu, err;
117 	cpumask_var_t tmp_mask;
118 
119 	if (cfg->move_in_progress)
120 		return -EBUSY;
121 
122 	if (!alloc_cpumask_var(&tmp_mask, GFP_ATOMIC))
123 		return -ENOMEM;
124 
125 	/* Only try and allocate irqs on cpus that are present */
126 	err = -ENOSPC;
127 	cpumask_clear(cfg->old_domain);
128 	cpu = cpumask_first_and(mask, cpu_online_mask);
129 	while (cpu < nr_cpu_ids) {
130 		int new_cpu, vector, offset;
131 
132 		apic->vector_allocation_domain(cpu, tmp_mask, mask);
133 
134 		if (cpumask_subset(tmp_mask, cfg->domain)) {
135 			err = 0;
136 			if (cpumask_equal(tmp_mask, cfg->domain))
137 				break;
138 			/*
139 			 * New cpumask using the vector is a proper subset of
140 			 * the current in use mask. So cleanup the vector
141 			 * allocation for the members that are not used anymore.
142 			 */
143 			cpumask_andnot(cfg->old_domain, cfg->domain, tmp_mask);
144 			cfg->move_in_progress =
145 			   cpumask_intersects(cfg->old_domain, cpu_online_mask);
146 			cpumask_and(cfg->domain, cfg->domain, tmp_mask);
147 			break;
148 		}
149 
150 		vector = current_vector;
151 		offset = current_offset;
152 next:
153 		vector += 16;
154 		if (vector >= first_system_vector) {
155 			offset = (offset + 1) % 16;
156 			vector = FIRST_EXTERNAL_VECTOR + offset;
157 		}
158 
159 		if (unlikely(current_vector == vector)) {
160 			cpumask_or(cfg->old_domain, cfg->old_domain, tmp_mask);
161 			cpumask_andnot(tmp_mask, mask, cfg->old_domain);
162 			cpu = cpumask_first_and(tmp_mask, cpu_online_mask);
163 			continue;
164 		}
165 
166 		if (test_bit(vector, used_vectors))
167 			goto next;
168 
169 		for_each_cpu_and(new_cpu, tmp_mask, cpu_online_mask) {
170 			if (per_cpu(vector_irq, new_cpu)[vector] >
171 			    VECTOR_UNDEFINED)
172 				goto next;
173 		}
174 		/* Found one! */
175 		current_vector = vector;
176 		current_offset = offset;
177 		if (cfg->vector) {
178 			cpumask_copy(cfg->old_domain, cfg->domain);
179 			cfg->move_in_progress =
180 			   cpumask_intersects(cfg->old_domain, cpu_online_mask);
181 		}
182 		for_each_cpu_and(new_cpu, tmp_mask, cpu_online_mask)
183 			per_cpu(vector_irq, new_cpu)[vector] = irq;
184 		cfg->vector = vector;
185 		cpumask_copy(cfg->domain, tmp_mask);
186 		err = 0;
187 		break;
188 	}
189 	free_cpumask_var(tmp_mask);
190 
191 	return err;
192 }
193 
194 int assign_irq_vector(int irq, struct irq_cfg *cfg, const struct cpumask *mask)
195 {
196 	int err;
197 	unsigned long flags;
198 
199 	raw_spin_lock_irqsave(&vector_lock, flags);
200 	err = __assign_irq_vector(irq, cfg, mask);
201 	raw_spin_unlock_irqrestore(&vector_lock, flags);
202 	return err;
203 }
204 
205 void clear_irq_vector(int irq, struct irq_cfg *cfg)
206 {
207 	int cpu, vector;
208 	unsigned long flags;
209 
210 	raw_spin_lock_irqsave(&vector_lock, flags);
211 	BUG_ON(!cfg->vector);
212 
213 	vector = cfg->vector;
214 	for_each_cpu_and(cpu, cfg->domain, cpu_online_mask)
215 		per_cpu(vector_irq, cpu)[vector] = VECTOR_UNDEFINED;
216 
217 	cfg->vector = 0;
218 	cpumask_clear(cfg->domain);
219 
220 	if (likely(!cfg->move_in_progress)) {
221 		raw_spin_unlock_irqrestore(&vector_lock, flags);
222 		return;
223 	}
224 
225 	for_each_cpu_and(cpu, cfg->old_domain, cpu_online_mask) {
226 		for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS;
227 		     vector++) {
228 			if (per_cpu(vector_irq, cpu)[vector] != irq)
229 				continue;
230 			per_cpu(vector_irq, cpu)[vector] = VECTOR_UNDEFINED;
231 			break;
232 		}
233 	}
234 	cfg->move_in_progress = 0;
235 	raw_spin_unlock_irqrestore(&vector_lock, flags);
236 }
237 
238 int __init arch_probe_nr_irqs(void)
239 {
240 	int nr;
241 
242 	if (nr_irqs > (NR_VECTORS * nr_cpu_ids))
243 		nr_irqs = NR_VECTORS * nr_cpu_ids;
244 
245 	nr = (gsi_top + nr_legacy_irqs()) + 8 * nr_cpu_ids;
246 #if defined(CONFIG_PCI_MSI) || defined(CONFIG_HT_IRQ)
247 	/*
248 	 * for MSI and HT dyn irq
249 	 */
250 	if (gsi_top <= NR_IRQS_LEGACY)
251 		nr +=  8 * nr_cpu_ids;
252 	else
253 		nr += gsi_top * 16;
254 #endif
255 	if (nr < nr_irqs)
256 		nr_irqs = nr;
257 
258 	return nr_legacy_irqs();
259 }
260 
261 int __init arch_early_irq_init(void)
262 {
263 	return arch_early_ioapic_init();
264 }
265 
266 static void __setup_vector_irq(int cpu)
267 {
268 	/* Initialize vector_irq on a new cpu */
269 	int irq, vector;
270 	struct irq_cfg *cfg;
271 
272 	/*
273 	 * vector_lock will make sure that we don't run into irq vector
274 	 * assignments that might be happening on another cpu in parallel,
275 	 * while we setup our initial vector to irq mappings.
276 	 */
277 	raw_spin_lock(&vector_lock);
278 	/* Mark the inuse vectors */
279 	for_each_active_irq(irq) {
280 		cfg = irq_cfg(irq);
281 		if (!cfg)
282 			continue;
283 
284 		if (!cpumask_test_cpu(cpu, cfg->domain))
285 			continue;
286 		vector = cfg->vector;
287 		per_cpu(vector_irq, cpu)[vector] = irq;
288 	}
289 	/* Mark the free vectors */
290 	for (vector = 0; vector < NR_VECTORS; ++vector) {
291 		irq = per_cpu(vector_irq, cpu)[vector];
292 		if (irq <= VECTOR_UNDEFINED)
293 			continue;
294 
295 		cfg = irq_cfg(irq);
296 		if (!cpumask_test_cpu(cpu, cfg->domain))
297 			per_cpu(vector_irq, cpu)[vector] = VECTOR_UNDEFINED;
298 	}
299 	raw_spin_unlock(&vector_lock);
300 }
301 
302 /*
303  * Setup the vector to irq mappings.
304  */
305 void setup_vector_irq(int cpu)
306 {
307 	int irq;
308 
309 	/*
310 	 * On most of the platforms, legacy PIC delivers the interrupts on the
311 	 * boot cpu. But there are certain platforms where PIC interrupts are
312 	 * delivered to multiple cpu's. If the legacy IRQ is handled by the
313 	 * legacy PIC, for the new cpu that is coming online, setup the static
314 	 * legacy vector to irq mapping:
315 	 */
316 	for (irq = 0; irq < nr_legacy_irqs(); irq++)
317 		per_cpu(vector_irq, cpu)[IRQ0_VECTOR + irq] = irq;
318 
319 	__setup_vector_irq(cpu);
320 }
321 
322 int apic_retrigger_irq(struct irq_data *data)
323 {
324 	struct irq_cfg *cfg = irqd_cfg(data);
325 	unsigned long flags;
326 	int cpu;
327 
328 	raw_spin_lock_irqsave(&vector_lock, flags);
329 	cpu = cpumask_first_and(cfg->domain, cpu_online_mask);
330 	apic->send_IPI_mask(cpumask_of(cpu), cfg->vector);
331 	raw_spin_unlock_irqrestore(&vector_lock, flags);
332 
333 	return 1;
334 }
335 
336 void apic_ack_edge(struct irq_data *data)
337 {
338 	irq_complete_move(irqd_cfg(data));
339 	irq_move_irq(data);
340 	ack_APIC_irq();
341 }
342 
343 /*
344  * Either sets data->affinity to a valid value, and returns
345  * ->cpu_mask_to_apicid of that in dest_id, or returns -1 and
346  * leaves data->affinity untouched.
347  */
348 int apic_set_affinity(struct irq_data *data, const struct cpumask *mask,
349 		      unsigned int *dest_id)
350 {
351 	struct irq_cfg *cfg = irqd_cfg(data);
352 	unsigned int irq = data->irq;
353 	int err;
354 
355 	if (!config_enabled(CONFIG_SMP))
356 		return -EPERM;
357 
358 	if (!cpumask_intersects(mask, cpu_online_mask))
359 		return -EINVAL;
360 
361 	err = assign_irq_vector(irq, cfg, mask);
362 	if (err)
363 		return err;
364 
365 	err = apic->cpu_mask_to_apicid_and(mask, cfg->domain, dest_id);
366 	if (err) {
367 		if (assign_irq_vector(irq, cfg, data->affinity))
368 			pr_err("Failed to recover vector for irq %d\n", irq);
369 		return err;
370 	}
371 
372 	cpumask_copy(data->affinity, mask);
373 
374 	return 0;
375 }
376 
377 #ifdef CONFIG_SMP
378 void send_cleanup_vector(struct irq_cfg *cfg)
379 {
380 	cpumask_var_t cleanup_mask;
381 
382 	if (unlikely(!alloc_cpumask_var(&cleanup_mask, GFP_ATOMIC))) {
383 		unsigned int i;
384 
385 		for_each_cpu_and(i, cfg->old_domain, cpu_online_mask)
386 			apic->send_IPI_mask(cpumask_of(i),
387 					    IRQ_MOVE_CLEANUP_VECTOR);
388 	} else {
389 		cpumask_and(cleanup_mask, cfg->old_domain, cpu_online_mask);
390 		apic->send_IPI_mask(cleanup_mask, IRQ_MOVE_CLEANUP_VECTOR);
391 		free_cpumask_var(cleanup_mask);
392 	}
393 	cfg->move_in_progress = 0;
394 }
395 
396 asmlinkage __visible void smp_irq_move_cleanup_interrupt(void)
397 {
398 	unsigned vector, me;
399 
400 	ack_APIC_irq();
401 	irq_enter();
402 	exit_idle();
403 
404 	me = smp_processor_id();
405 	for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
406 		int irq;
407 		unsigned int irr;
408 		struct irq_desc *desc;
409 		struct irq_cfg *cfg;
410 
411 		irq = __this_cpu_read(vector_irq[vector]);
412 
413 		if (irq <= VECTOR_UNDEFINED)
414 			continue;
415 
416 		desc = irq_to_desc(irq);
417 		if (!desc)
418 			continue;
419 
420 		cfg = irq_cfg(irq);
421 		if (!cfg)
422 			continue;
423 
424 		raw_spin_lock(&desc->lock);
425 
426 		/*
427 		 * Check if the irq migration is in progress. If so, we
428 		 * haven't received the cleanup request yet for this irq.
429 		 */
430 		if (cfg->move_in_progress)
431 			goto unlock;
432 
433 		if (vector == cfg->vector && cpumask_test_cpu(me, cfg->domain))
434 			goto unlock;
435 
436 		irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
437 		/*
438 		 * Check if the vector that needs to be cleanedup is
439 		 * registered at the cpu's IRR. If so, then this is not
440 		 * the best time to clean it up. Lets clean it up in the
441 		 * next attempt by sending another IRQ_MOVE_CLEANUP_VECTOR
442 		 * to myself.
443 		 */
444 		if (irr  & (1 << (vector % 32))) {
445 			apic->send_IPI_self(IRQ_MOVE_CLEANUP_VECTOR);
446 			goto unlock;
447 		}
448 		__this_cpu_write(vector_irq[vector], VECTOR_UNDEFINED);
449 unlock:
450 		raw_spin_unlock(&desc->lock);
451 	}
452 
453 	irq_exit();
454 }
455 
456 static void __irq_complete_move(struct irq_cfg *cfg, unsigned vector)
457 {
458 	unsigned me;
459 
460 	if (likely(!cfg->move_in_progress))
461 		return;
462 
463 	me = smp_processor_id();
464 
465 	if (vector == cfg->vector && cpumask_test_cpu(me, cfg->domain))
466 		send_cleanup_vector(cfg);
467 }
468 
469 void irq_complete_move(struct irq_cfg *cfg)
470 {
471 	__irq_complete_move(cfg, ~get_irq_regs()->orig_ax);
472 }
473 
474 void irq_force_complete_move(int irq)
475 {
476 	struct irq_cfg *cfg = irq_cfg(irq);
477 
478 	if (!cfg)
479 		return;
480 
481 	__irq_complete_move(cfg, cfg->vector);
482 }
483 #endif
484 
485 /*
486  * Dynamic irq allocate and deallocation. Should be replaced by irq domains!
487  */
488 int arch_setup_hwirq(unsigned int irq, int node)
489 {
490 	struct irq_cfg *cfg;
491 	unsigned long flags;
492 	int ret;
493 
494 	cfg = alloc_irq_cfg(irq, node);
495 	if (!cfg)
496 		return -ENOMEM;
497 
498 	raw_spin_lock_irqsave(&vector_lock, flags);
499 	ret = __assign_irq_vector(irq, cfg, apic->target_cpus());
500 	raw_spin_unlock_irqrestore(&vector_lock, flags);
501 
502 	if (!ret)
503 		irq_set_chip_data(irq, cfg);
504 	else
505 		free_irq_cfg(irq, cfg);
506 	return ret;
507 }
508 
509 void arch_teardown_hwirq(unsigned int irq)
510 {
511 	struct irq_cfg *cfg = irq_cfg(irq);
512 
513 	free_remapped_irq(irq);
514 	clear_irq_vector(irq, cfg);
515 	free_irq_cfg(irq, cfg);
516 }
517 
518 static void __init print_APIC_field(int base)
519 {
520 	int i;
521 
522 	printk(KERN_DEBUG);
523 
524 	for (i = 0; i < 8; i++)
525 		pr_cont("%08x", apic_read(base + i*0x10));
526 
527 	pr_cont("\n");
528 }
529 
530 static void __init print_local_APIC(void *dummy)
531 {
532 	unsigned int i, v, ver, maxlvt;
533 	u64 icr;
534 
535 	pr_debug("printing local APIC contents on CPU#%d/%d:\n",
536 		 smp_processor_id(), hard_smp_processor_id());
537 	v = apic_read(APIC_ID);
538 	pr_info("... APIC ID:      %08x (%01x)\n", v, read_apic_id());
539 	v = apic_read(APIC_LVR);
540 	pr_info("... APIC VERSION: %08x\n", v);
541 	ver = GET_APIC_VERSION(v);
542 	maxlvt = lapic_get_maxlvt();
543 
544 	v = apic_read(APIC_TASKPRI);
545 	pr_debug("... APIC TASKPRI: %08x (%02x)\n", v, v & APIC_TPRI_MASK);
546 
547 	/* !82489DX */
548 	if (APIC_INTEGRATED(ver)) {
549 		if (!APIC_XAPIC(ver)) {
550 			v = apic_read(APIC_ARBPRI);
551 			pr_debug("... APIC ARBPRI: %08x (%02x)\n",
552 				 v, v & APIC_ARBPRI_MASK);
553 		}
554 		v = apic_read(APIC_PROCPRI);
555 		pr_debug("... APIC PROCPRI: %08x\n", v);
556 	}
557 
558 	/*
559 	 * Remote read supported only in the 82489DX and local APIC for
560 	 * Pentium processors.
561 	 */
562 	if (!APIC_INTEGRATED(ver) || maxlvt == 3) {
563 		v = apic_read(APIC_RRR);
564 		pr_debug("... APIC RRR: %08x\n", v);
565 	}
566 
567 	v = apic_read(APIC_LDR);
568 	pr_debug("... APIC LDR: %08x\n", v);
569 	if (!x2apic_enabled()) {
570 		v = apic_read(APIC_DFR);
571 		pr_debug("... APIC DFR: %08x\n", v);
572 	}
573 	v = apic_read(APIC_SPIV);
574 	pr_debug("... APIC SPIV: %08x\n", v);
575 
576 	pr_debug("... APIC ISR field:\n");
577 	print_APIC_field(APIC_ISR);
578 	pr_debug("... APIC TMR field:\n");
579 	print_APIC_field(APIC_TMR);
580 	pr_debug("... APIC IRR field:\n");
581 	print_APIC_field(APIC_IRR);
582 
583 	/* !82489DX */
584 	if (APIC_INTEGRATED(ver)) {
585 		/* Due to the Pentium erratum 3AP. */
586 		if (maxlvt > 3)
587 			apic_write(APIC_ESR, 0);
588 
589 		v = apic_read(APIC_ESR);
590 		pr_debug("... APIC ESR: %08x\n", v);
591 	}
592 
593 	icr = apic_icr_read();
594 	pr_debug("... APIC ICR: %08x\n", (u32)icr);
595 	pr_debug("... APIC ICR2: %08x\n", (u32)(icr >> 32));
596 
597 	v = apic_read(APIC_LVTT);
598 	pr_debug("... APIC LVTT: %08x\n", v);
599 
600 	if (maxlvt > 3) {
601 		/* PC is LVT#4. */
602 		v = apic_read(APIC_LVTPC);
603 		pr_debug("... APIC LVTPC: %08x\n", v);
604 	}
605 	v = apic_read(APIC_LVT0);
606 	pr_debug("... APIC LVT0: %08x\n", v);
607 	v = apic_read(APIC_LVT1);
608 	pr_debug("... APIC LVT1: %08x\n", v);
609 
610 	if (maxlvt > 2) {
611 		/* ERR is LVT#3. */
612 		v = apic_read(APIC_LVTERR);
613 		pr_debug("... APIC LVTERR: %08x\n", v);
614 	}
615 
616 	v = apic_read(APIC_TMICT);
617 	pr_debug("... APIC TMICT: %08x\n", v);
618 	v = apic_read(APIC_TMCCT);
619 	pr_debug("... APIC TMCCT: %08x\n", v);
620 	v = apic_read(APIC_TDCR);
621 	pr_debug("... APIC TDCR: %08x\n", v);
622 
623 	if (boot_cpu_has(X86_FEATURE_EXTAPIC)) {
624 		v = apic_read(APIC_EFEAT);
625 		maxlvt = (v >> 16) & 0xff;
626 		pr_debug("... APIC EFEAT: %08x\n", v);
627 		v = apic_read(APIC_ECTRL);
628 		pr_debug("... APIC ECTRL: %08x\n", v);
629 		for (i = 0; i < maxlvt; i++) {
630 			v = apic_read(APIC_EILVTn(i));
631 			pr_debug("... APIC EILVT%d: %08x\n", i, v);
632 		}
633 	}
634 	pr_cont("\n");
635 }
636 
637 static void __init print_local_APICs(int maxcpu)
638 {
639 	int cpu;
640 
641 	if (!maxcpu)
642 		return;
643 
644 	preempt_disable();
645 	for_each_online_cpu(cpu) {
646 		if (cpu >= maxcpu)
647 			break;
648 		smp_call_function_single(cpu, print_local_APIC, NULL, 1);
649 	}
650 	preempt_enable();
651 }
652 
653 static void __init print_PIC(void)
654 {
655 	unsigned int v;
656 	unsigned long flags;
657 
658 	if (!nr_legacy_irqs())
659 		return;
660 
661 	pr_debug("\nprinting PIC contents\n");
662 
663 	raw_spin_lock_irqsave(&i8259A_lock, flags);
664 
665 	v = inb(0xa1) << 8 | inb(0x21);
666 	pr_debug("... PIC  IMR: %04x\n", v);
667 
668 	v = inb(0xa0) << 8 | inb(0x20);
669 	pr_debug("... PIC  IRR: %04x\n", v);
670 
671 	outb(0x0b, 0xa0);
672 	outb(0x0b, 0x20);
673 	v = inb(0xa0) << 8 | inb(0x20);
674 	outb(0x0a, 0xa0);
675 	outb(0x0a, 0x20);
676 
677 	raw_spin_unlock_irqrestore(&i8259A_lock, flags);
678 
679 	pr_debug("... PIC  ISR: %04x\n", v);
680 
681 	v = inb(0x4d1) << 8 | inb(0x4d0);
682 	pr_debug("... PIC ELCR: %04x\n", v);
683 }
684 
685 static int show_lapic __initdata = 1;
686 static __init int setup_show_lapic(char *arg)
687 {
688 	int num = -1;
689 
690 	if (strcmp(arg, "all") == 0) {
691 		show_lapic = CONFIG_NR_CPUS;
692 	} else {
693 		get_option(&arg, &num);
694 		if (num >= 0)
695 			show_lapic = num;
696 	}
697 
698 	return 1;
699 }
700 __setup("show_lapic=", setup_show_lapic);
701 
702 static int __init print_ICs(void)
703 {
704 	if (apic_verbosity == APIC_QUIET)
705 		return 0;
706 
707 	print_PIC();
708 
709 	/* don't print out if apic is not there */
710 	if (!cpu_has_apic && !apic_from_smp_config())
711 		return 0;
712 
713 	print_local_APICs(show_lapic);
714 	print_IO_APICs();
715 
716 	return 0;
717 }
718 
719 late_initcall(print_ICs);
720