1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Local APIC related interfaces to support IOAPIC, MSI, etc.
4 *
5 * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
6 * Moved from arch/x86/kernel/apic/io_apic.c.
7 * Jiang Liu <jiang.liu@linux.intel.com>
8 * Enable support of hierarchical irqdomains
9 */
10#include <linux/interrupt.h>
11#include <linux/irq.h>
12#include <linux/seq_file.h>
13#include <linux/init.h>
14#include <linux/compiler.h>
15#include <linux/slab.h>
16#include <asm/irqdomain.h>
17#include <asm/hw_irq.h>
18#include <asm/traps.h>
19#include <asm/apic.h>
20#include <asm/i8259.h>
21#include <asm/desc.h>
22#include <asm/irq_remapping.h>
23
24#include <asm/trace/irq_vectors.h>
25
26struct apic_chip_data {
27 struct irq_cfg hw_irq_cfg;
28 unsigned int vector;
29 unsigned int prev_vector;
30 unsigned int cpu;
31 unsigned int prev_cpu;
32 unsigned int irq;
33 struct hlist_node clist;
34 unsigned int move_in_progress : 1,
35 is_managed : 1,
36 can_reserve : 1,
37 has_reserved : 1;
38};
39
40struct irq_domain *x86_vector_domain;
41EXPORT_SYMBOL_GPL(x86_vector_domain);
42static DEFINE_RAW_SPINLOCK(vector_lock);
43static cpumask_var_t vector_searchmask;
44static struct irq_chip lapic_controller;
45static struct irq_matrix *vector_matrix;
46#ifdef CONFIG_SMP
47
48static void vector_cleanup_callback(struct timer_list *tmr);
49
50struct vector_cleanup {
51 struct hlist_head head;
52 struct timer_list timer;
53};
54
55static DEFINE_PER_CPU(struct vector_cleanup, vector_cleanup) = {
56 .head = HLIST_HEAD_INIT,
57 .timer = __TIMER_INITIALIZER(vector_cleanup_callback, TIMER_PINNED),
58};
59#endif
60
61void lock_vector_lock(void)
62{
63 /* Used to the online set of cpus does not change
64 * during assign_irq_vector.
65 */
66 raw_spin_lock(&vector_lock);
67}
68
69void unlock_vector_lock(void)
70{
71 raw_spin_unlock(&vector_lock);
72}
73
74void init_irq_alloc_info(struct irq_alloc_info *info,
75 const struct cpumask *mask)
76{
77 memset(info, 0, sizeof(*info));
78 info->mask = mask;
79}
80
81void copy_irq_alloc_info(struct irq_alloc_info *dst, struct irq_alloc_info *src)
82{
83 if (src)
84 *dst = *src;
85 else
86 memset(dst, 0, sizeof(*dst));
87}
88
89static struct apic_chip_data *apic_chip_data(struct irq_data *irqd)
90{
91 if (!irqd)
92 return NULL;
93
94 while (irqd->parent_data)
95 irqd = irqd->parent_data;
96
97 return irqd->chip_data;
98}
99
100struct irq_cfg *irqd_cfg(struct irq_data *irqd)
101{
102 struct apic_chip_data *apicd = apic_chip_data(irqd);
103
104 return apicd ? &apicd->hw_irq_cfg : NULL;
105}
106EXPORT_SYMBOL_GPL(irqd_cfg);
107
108struct irq_cfg *irq_cfg(unsigned int irq)
109{
110 return irqd_cfg(irq_get_irq_data(irq));
111}
112
113static struct apic_chip_data *alloc_apic_chip_data(int node)
114{
115 struct apic_chip_data *apicd;
116
117 apicd = kzalloc_node(sizeof(*apicd), GFP_KERNEL, node);
118 if (apicd)
119 INIT_HLIST_NODE(h: &apicd->clist);
120 return apicd;
121}
122
123static void free_apic_chip_data(struct apic_chip_data *apicd)
124{
125 kfree(objp: apicd);
126}
127
128static void apic_update_irq_cfg(struct irq_data *irqd, unsigned int vector,
129 unsigned int cpu)
130{
131 struct apic_chip_data *apicd = apic_chip_data(irqd);
132
133 lockdep_assert_held(&vector_lock);
134
135 apicd->hw_irq_cfg.vector = vector;
136 apicd->hw_irq_cfg.dest_apicid = apic->calc_dest_apicid(cpu);
137
138 apic_update_vector(cpu, vector, set: true);
139
140 irq_data_update_effective_affinity(d: irqd, cpumask_of(cpu));
141 trace_vector_config(irq: irqd->irq, vector, cpu, apicdest: apicd->hw_irq_cfg.dest_apicid);
142}
143
144static void apic_free_vector(unsigned int cpu, unsigned int vector, bool managed)
145{
146 apic_update_vector(cpu, vector, set: false);
147 irq_matrix_free(m: vector_matrix, cpu, bit: vector, managed);
148}
149
150static void chip_data_update(struct irq_data *irqd, unsigned int newvec, unsigned int newcpu)
151{
152 struct apic_chip_data *apicd = apic_chip_data(irqd);
153 struct irq_desc *desc = irq_data_to_desc(data: irqd);
154 bool managed = irqd_affinity_is_managed(d: irqd);
155
156 lockdep_assert_held(&vector_lock);
157
158 trace_vector_update(irq: irqd->irq, vector: newvec, cpu: newcpu, prev_vector: apicd->vector,
159 prev_cpu: apicd->cpu);
160
161 /*
162 * If there is no vector associated or if the associated vector is
163 * the shutdown vector, which is associated to make PCI/MSI
164 * shutdown mode work, then there is nothing to release. Clear out
165 * prev_vector for this and the offlined target case.
166 */
167 apicd->prev_vector = 0;
168 if (!apicd->vector || apicd->vector == MANAGED_IRQ_SHUTDOWN_VECTOR)
169 goto setnew;
170 /*
171 * If the target CPU of the previous vector is online, then mark
172 * the vector as move in progress and store it for cleanup when the
173 * first interrupt on the new vector arrives. If the target CPU is
174 * offline then the regular release mechanism via the cleanup
175 * vector is not possible and the vector can be immediately freed
176 * in the underlying matrix allocator.
177 */
178 if (cpu_online(cpu: apicd->cpu)) {
179 apicd->move_in_progress = true;
180 apicd->prev_vector = apicd->vector;
181 apicd->prev_cpu = apicd->cpu;
182 WARN_ON_ONCE(apicd->cpu == newcpu);
183 } else {
184 apic_free_vector(cpu: apicd->cpu, vector: apicd->vector, managed);
185 }
186
187setnew:
188 apicd->vector = newvec;
189 apicd->cpu = newcpu;
190 BUG_ON(!IS_ERR_OR_NULL(per_cpu(vector_irq, newcpu)[newvec]));
191 per_cpu(vector_irq, newcpu)[newvec] = desc;
192 apic_update_irq_cfg(irqd, vector: newvec, cpu: newcpu);
193}
194
195static void vector_assign_managed_shutdown(struct irq_data *irqd)
196{
197 unsigned int cpu = cpumask_first(cpu_online_mask);
198
199 apic_update_irq_cfg(irqd, MANAGED_IRQ_SHUTDOWN_VECTOR, cpu);
200}
201
202static int reserve_managed_vector(struct irq_data *irqd)
203{
204 const struct cpumask *affmsk = irq_data_get_affinity_mask(d: irqd);
205 struct apic_chip_data *apicd = apic_chip_data(irqd);
206 unsigned long flags;
207 int ret;
208
209 raw_spin_lock_irqsave(&vector_lock, flags);
210 apicd->is_managed = true;
211 ret = irq_matrix_reserve_managed(m: vector_matrix, msk: affmsk);
212 raw_spin_unlock_irqrestore(&vector_lock, flags);
213 trace_vector_reserve_managed(irq: irqd->irq, ret);
214 return ret;
215}
216
217static void reserve_irq_vector_locked(struct irq_data *irqd)
218{
219 struct apic_chip_data *apicd = apic_chip_data(irqd);
220
221 irq_matrix_reserve(m: vector_matrix);
222 apicd->can_reserve = true;
223 apicd->has_reserved = true;
224 irqd_set_can_reserve(d: irqd);
225 trace_vector_reserve(irq: irqd->irq, ret: 0);
226 vector_assign_managed_shutdown(irqd);
227}
228
229static int reserve_irq_vector(struct irq_data *irqd)
230{
231 unsigned long flags;
232
233 raw_spin_lock_irqsave(&vector_lock, flags);
234 reserve_irq_vector_locked(irqd);
235 raw_spin_unlock_irqrestore(&vector_lock, flags);
236 return 0;
237}
238
239static int
240assign_vector_locked(struct irq_data *irqd, const struct cpumask *dest)
241{
242 struct apic_chip_data *apicd = apic_chip_data(irqd);
243 bool resvd = apicd->has_reserved;
244 unsigned int cpu = apicd->cpu;
245 int vector = apicd->vector;
246
247 lockdep_assert_held(&vector_lock);
248
249 /*
250 * If the current target CPU is online and in the new requested
251 * affinity mask, there is no point in moving the interrupt from
252 * one CPU to another.
253 */
254 if (vector && cpu_online(cpu) && cpumask_test_cpu(cpu, cpumask: dest))
255 return 0;
256
257 /*
258 * Careful here. @apicd might either have move_in_progress set or
259 * be enqueued for cleanup. Assigning a new vector would either
260 * leave a stale vector on some CPU around or in case of a pending
261 * cleanup corrupt the hlist.
262 */
263 if (apicd->move_in_progress || !hlist_unhashed(h: &apicd->clist))
264 return -EBUSY;
265
266 vector = irq_matrix_alloc(m: vector_matrix, msk: dest, reserved: resvd, mapped_cpu: &cpu);
267 trace_vector_alloc(irq: irqd->irq, vector, reserved: resvd, ret: vector);
268 if (vector < 0)
269 return vector;
270 chip_data_update(irqd, newvec: vector, newcpu: cpu);
271
272 return 0;
273}
274
275static int assign_irq_vector(struct irq_data *irqd, const struct cpumask *dest)
276{
277 unsigned long flags;
278 int ret;
279
280 raw_spin_lock_irqsave(&vector_lock, flags);
281 cpumask_and(dstp: vector_searchmask, src1p: dest, cpu_online_mask);
282 ret = assign_vector_locked(irqd, dest: vector_searchmask);
283 raw_spin_unlock_irqrestore(&vector_lock, flags);
284 return ret;
285}
286
287static int assign_irq_vector_any_locked(struct irq_data *irqd)
288{
289 /* Get the affinity mask - either irq_default_affinity or (user) set */
290 const struct cpumask *affmsk = irq_data_get_affinity_mask(d: irqd);
291 int node = irq_data_get_node(d: irqd);
292
293 if (node != NUMA_NO_NODE) {
294 /* Try the intersection of @affmsk and node mask */
295 cpumask_and(dstp: vector_searchmask, src1p: cpumask_of_node(node), src2p: affmsk);
296 if (!assign_vector_locked(irqd, dest: vector_searchmask))
297 return 0;
298 }
299
300 /* Try the full affinity mask */
301 cpumask_and(dstp: vector_searchmask, src1p: affmsk, cpu_online_mask);
302 if (!assign_vector_locked(irqd, dest: vector_searchmask))
303 return 0;
304
305 if (node != NUMA_NO_NODE) {
306 /* Try the node mask */
307 if (!assign_vector_locked(irqd, dest: cpumask_of_node(node)))
308 return 0;
309 }
310
311 /* Try the full online mask */
312 return assign_vector_locked(irqd, cpu_online_mask);
313}
314
315static int
316assign_irq_vector_policy(struct irq_data *irqd, struct irq_alloc_info *info)
317{
318 if (irqd_affinity_is_managed(d: irqd))
319 return reserve_managed_vector(irqd);
320 if (info->mask)
321 return assign_irq_vector(irqd, dest: info->mask);
322 /*
323 * Make only a global reservation with no guarantee. A real vector
324 * is associated at activation time.
325 */
326 return reserve_irq_vector(irqd);
327}
328
329static int
330assign_managed_vector(struct irq_data *irqd, const struct cpumask *dest)
331{
332 const struct cpumask *affmsk = irq_data_get_affinity_mask(d: irqd);
333 struct apic_chip_data *apicd = apic_chip_data(irqd);
334 int vector, cpu;
335
336 cpumask_and(dstp: vector_searchmask, src1p: dest, src2p: affmsk);
337
338 /* set_affinity might call here for nothing */
339 if (apicd->vector && cpumask_test_cpu(cpu: apicd->cpu, cpumask: vector_searchmask))
340 return 0;
341 vector = irq_matrix_alloc_managed(m: vector_matrix, msk: vector_searchmask,
342 mapped_cpu: &cpu);
343 trace_vector_alloc_managed(irq: irqd->irq, vector, ret: vector);
344 if (vector < 0)
345 return vector;
346 chip_data_update(irqd, newvec: vector, newcpu: cpu);
347
348 return 0;
349}
350
351static void clear_irq_vector(struct irq_data *irqd)
352{
353 struct apic_chip_data *apicd = apic_chip_data(irqd);
354 bool managed = irqd_affinity_is_managed(d: irqd);
355 unsigned int vector = apicd->vector;
356
357 lockdep_assert_held(&vector_lock);
358
359 if (!vector)
360 return;
361
362 trace_vector_clear(irq: irqd->irq, vector, cpu: apicd->cpu, prev_vector: apicd->prev_vector,
363 prev_cpu: apicd->prev_cpu);
364
365 per_cpu(vector_irq, apicd->cpu)[vector] = VECTOR_SHUTDOWN;
366 apic_free_vector(cpu: apicd->cpu, vector, managed);
367 apicd->vector = 0;
368
369 /* Clean up move in progress */
370 vector = apicd->prev_vector;
371 if (!vector)
372 return;
373
374 per_cpu(vector_irq, apicd->prev_cpu)[vector] = VECTOR_SHUTDOWN;
375 apic_free_vector(cpu: apicd->prev_cpu, vector, managed);
376 apicd->prev_vector = 0;
377 apicd->move_in_progress = 0;
378 hlist_del_init(n: &apicd->clist);
379}
380
381static void x86_vector_deactivate(struct irq_domain *dom, struct irq_data *irqd)
382{
383 struct apic_chip_data *apicd = apic_chip_data(irqd);
384 unsigned long flags;
385
386 trace_vector_deactivate(irq: irqd->irq, is_managed: apicd->is_managed,
387 can_reserve: apicd->can_reserve, reserve: false);
388
389 /* Regular fixed assigned interrupt */
390 if (!apicd->is_managed && !apicd->can_reserve)
391 return;
392 /* If the interrupt has a global reservation, nothing to do */
393 if (apicd->has_reserved)
394 return;
395
396 raw_spin_lock_irqsave(&vector_lock, flags);
397 clear_irq_vector(irqd);
398 if (apicd->can_reserve)
399 reserve_irq_vector_locked(irqd);
400 else
401 vector_assign_managed_shutdown(irqd);
402 raw_spin_unlock_irqrestore(&vector_lock, flags);
403}
404
405static int activate_reserved(struct irq_data *irqd)
406{
407 struct apic_chip_data *apicd = apic_chip_data(irqd);
408 int ret;
409
410 ret = assign_irq_vector_any_locked(irqd);
411 if (!ret) {
412 apicd->has_reserved = false;
413 /*
414 * Core might have disabled reservation mode after
415 * allocating the irq descriptor. Ideally this should
416 * happen before allocation time, but that would require
417 * completely convoluted ways of transporting that
418 * information.
419 */
420 if (!irqd_can_reserve(d: irqd))
421 apicd->can_reserve = false;
422 }
423
424 /*
425 * Check to ensure that the effective affinity mask is a subset
426 * the user supplied affinity mask, and warn the user if it is not
427 */
428 if (!cpumask_subset(src1p: irq_data_get_effective_affinity_mask(d: irqd),
429 src2p: irq_data_get_affinity_mask(d: irqd))) {
430 pr_warn("irq %u: Affinity broken due to vector space exhaustion.\n",
431 irqd->irq);
432 }
433
434 return ret;
435}
436
437static int activate_managed(struct irq_data *irqd)
438{
439 const struct cpumask *dest = irq_data_get_affinity_mask(d: irqd);
440 int ret;
441
442 cpumask_and(dstp: vector_searchmask, src1p: dest, cpu_online_mask);
443 if (WARN_ON_ONCE(cpumask_empty(vector_searchmask))) {
444 /* Something in the core code broke! Survive gracefully */
445 pr_err("Managed startup for irq %u, but no CPU\n", irqd->irq);
446 return -EINVAL;
447 }
448
449 ret = assign_managed_vector(irqd, dest: vector_searchmask);
450 /*
451 * This should not happen. The vector reservation got buggered. Handle
452 * it gracefully.
453 */
454 if (WARN_ON_ONCE(ret < 0)) {
455 pr_err("Managed startup irq %u, no vector available\n",
456 irqd->irq);
457 }
458 return ret;
459}
460
461static int x86_vector_activate(struct irq_domain *dom, struct irq_data *irqd,
462 bool reserve)
463{
464 struct apic_chip_data *apicd = apic_chip_data(irqd);
465 unsigned long flags;
466 int ret = 0;
467
468 trace_vector_activate(irq: irqd->irq, is_managed: apicd->is_managed,
469 can_reserve: apicd->can_reserve, reserve);
470
471 raw_spin_lock_irqsave(&vector_lock, flags);
472 if (!apicd->can_reserve && !apicd->is_managed)
473 assign_irq_vector_any_locked(irqd);
474 else if (reserve || irqd_is_managed_and_shutdown(d: irqd))
475 vector_assign_managed_shutdown(irqd);
476 else if (apicd->is_managed)
477 ret = activate_managed(irqd);
478 else if (apicd->has_reserved)
479 ret = activate_reserved(irqd);
480 raw_spin_unlock_irqrestore(&vector_lock, flags);
481 return ret;
482}
483
484static void vector_free_reserved_and_managed(struct irq_data *irqd)
485{
486 const struct cpumask *dest = irq_data_get_affinity_mask(d: irqd);
487 struct apic_chip_data *apicd = apic_chip_data(irqd);
488
489 trace_vector_teardown(irq: irqd->irq, is_managed: apicd->is_managed,
490 has_reserved: apicd->has_reserved);
491
492 if (apicd->has_reserved)
493 irq_matrix_remove_reserved(m: vector_matrix);
494 if (apicd->is_managed)
495 irq_matrix_remove_managed(m: vector_matrix, msk: dest);
496}
497
498static void x86_vector_free_irqs(struct irq_domain *domain,
499 unsigned int virq, unsigned int nr_irqs)
500{
501 struct apic_chip_data *apicd;
502 struct irq_data *irqd;
503 unsigned long flags;
504 int i;
505
506 for (i = 0; i < nr_irqs; i++) {
507 irqd = irq_domain_get_irq_data(domain: x86_vector_domain, virq: virq + i);
508 if (irqd && irqd->chip_data) {
509 raw_spin_lock_irqsave(&vector_lock, flags);
510 clear_irq_vector(irqd);
511 vector_free_reserved_and_managed(irqd);
512 apicd = irqd->chip_data;
513 irq_domain_reset_irq_data(irq_data: irqd);
514 raw_spin_unlock_irqrestore(&vector_lock, flags);
515 free_apic_chip_data(apicd);
516 }
517 }
518}
519
520static bool vector_configure_legacy(unsigned int virq, struct irq_data *irqd,
521 struct apic_chip_data *apicd)
522{
523 unsigned long flags;
524 bool realloc = false;
525
526 apicd->vector = ISA_IRQ_VECTOR(virq);
527 apicd->cpu = 0;
528
529 raw_spin_lock_irqsave(&vector_lock, flags);
530 /*
531 * If the interrupt is activated, then it must stay at this vector
532 * position. That's usually the timer interrupt (0).
533 */
534 if (irqd_is_activated(d: irqd)) {
535 trace_vector_setup(irq: virq, is_legacy: true, ret: 0);
536 apic_update_irq_cfg(irqd, vector: apicd->vector, cpu: apicd->cpu);
537 } else {
538 /* Release the vector */
539 apicd->can_reserve = true;
540 irqd_set_can_reserve(d: irqd);
541 clear_irq_vector(irqd);
542 realloc = true;
543 }
544 raw_spin_unlock_irqrestore(&vector_lock, flags);
545 return realloc;
546}
547
548static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq,
549 unsigned int nr_irqs, void *arg)
550{
551 struct irq_alloc_info *info = arg;
552 struct apic_chip_data *apicd;
553 struct irq_data *irqd;
554 int i, err, node;
555
556 if (apic_is_disabled)
557 return -ENXIO;
558
559 /*
560 * Catch any attempt to touch the cascade interrupt on a PIC
561 * equipped system.
562 */
563 if (WARN_ON_ONCE(info->flags & X86_IRQ_ALLOC_LEGACY &&
564 virq == PIC_CASCADE_IR))
565 return -EINVAL;
566
567 for (i = 0; i < nr_irqs; i++) {
568 irqd = irq_domain_get_irq_data(domain, virq: virq + i);
569 BUG_ON(!irqd);
570 node = irq_data_get_node(d: irqd);
571 WARN_ON_ONCE(irqd->chip_data);
572 apicd = alloc_apic_chip_data(node);
573 if (!apicd) {
574 err = -ENOMEM;
575 goto error;
576 }
577
578 apicd->irq = virq + i;
579 irqd->chip = &lapic_controller;
580 irqd->chip_data = apicd;
581 irqd->hwirq = virq + i;
582 irqd_set_single_target(d: irqd);
583 /*
584 * Prevent that any of these interrupts is invoked in
585 * non interrupt context via e.g. generic_handle_irq()
586 * as that can corrupt the affinity move state.
587 */
588 irqd_set_handle_enforce_irqctx(d: irqd);
589
590 /* Don't invoke affinity setter on deactivated interrupts */
591 irqd_set_affinity_on_activate(d: irqd);
592
593 /*
594 * Legacy vectors are already assigned when the IOAPIC
595 * takes them over. They stay on the same vector. This is
596 * required for check_timer() to work correctly as it might
597 * switch back to legacy mode. Only update the hardware
598 * config.
599 */
600 if (info->flags & X86_IRQ_ALLOC_LEGACY) {
601 if (!vector_configure_legacy(virq: virq + i, irqd, apicd))
602 continue;
603 }
604
605 err = assign_irq_vector_policy(irqd, info);
606 trace_vector_setup(irq: virq + i, is_legacy: false, ret: err);
607 if (err) {
608 irqd->chip_data = NULL;
609 free_apic_chip_data(apicd);
610 goto error;
611 }
612 }
613
614 return 0;
615
616error:
617 x86_vector_free_irqs(domain, virq, nr_irqs: i);
618 return err;
619}
620
621#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
622static void x86_vector_debug_show(struct seq_file *m, struct irq_domain *d,
623 struct irq_data *irqd, int ind)
624{
625 struct apic_chip_data apicd;
626 unsigned long flags;
627 int irq;
628
629 if (!irqd) {
630 irq_matrix_debug_show(sf: m, m: vector_matrix, ind);
631 return;
632 }
633
634 irq = irqd->irq;
635 if (irq < nr_legacy_irqs() && !test_bit(irq, &io_apic_irqs)) {
636 seq_printf(m, fmt: "%*sVector: %5d\n", ind, "", ISA_IRQ_VECTOR(irq));
637 seq_printf(m, fmt: "%*sTarget: Legacy PIC all CPUs\n", ind, "");
638 return;
639 }
640
641 if (!irqd->chip_data) {
642 seq_printf(m, fmt: "%*sVector: Not assigned\n", ind, "");
643 return;
644 }
645
646 raw_spin_lock_irqsave(&vector_lock, flags);
647 memcpy(&apicd, irqd->chip_data, sizeof(apicd));
648 raw_spin_unlock_irqrestore(&vector_lock, flags);
649
650 seq_printf(m, fmt: "%*sVector: %5u\n", ind, "", apicd.vector);
651 seq_printf(m, fmt: "%*sTarget: %5u\n", ind, "", apicd.cpu);
652 if (apicd.prev_vector) {
653 seq_printf(m, fmt: "%*sPrevious vector: %5u\n", ind, "", apicd.prev_vector);
654 seq_printf(m, fmt: "%*sPrevious target: %5u\n", ind, "", apicd.prev_cpu);
655 }
656 seq_printf(m, fmt: "%*smove_in_progress: %u\n", ind, "", apicd.move_in_progress ? 1 : 0);
657 seq_printf(m, fmt: "%*sis_managed: %u\n", ind, "", apicd.is_managed ? 1 : 0);
658 seq_printf(m, fmt: "%*scan_reserve: %u\n", ind, "", apicd.can_reserve ? 1 : 0);
659 seq_printf(m, fmt: "%*shas_reserved: %u\n", ind, "", apicd.has_reserved ? 1 : 0);
660 seq_printf(m, fmt: "%*scleanup_pending: %u\n", ind, "", !hlist_unhashed(h: &apicd.clist));
661}
662#endif
663
664int x86_fwspec_is_ioapic(struct irq_fwspec *fwspec)
665{
666 if (fwspec->param_count != 1)
667 return 0;
668
669 if (is_fwnode_irqchip(fwnode: fwspec->fwnode)) {
670 const char *fwname = fwnode_get_name(fwnode: fwspec->fwnode);
671 return fwname && !strncmp(fwname, "IO-APIC-", 8) &&
672 simple_strtol(fwname+8, NULL, 10) == fwspec->param[0];
673 }
674 return to_of_node(fwspec->fwnode) &&
675 of_device_is_compatible(to_of_node(fwspec->fwnode),
676 "intel,ce4100-ioapic");
677}
678
679int x86_fwspec_is_hpet(struct irq_fwspec *fwspec)
680{
681 if (fwspec->param_count != 1)
682 return 0;
683
684 if (is_fwnode_irqchip(fwnode: fwspec->fwnode)) {
685 const char *fwname = fwnode_get_name(fwnode: fwspec->fwnode);
686 return fwname && !strncmp(fwname, "HPET-MSI-", 9) &&
687 simple_strtol(fwname+9, NULL, 10) == fwspec->param[0];
688 }
689 return 0;
690}
691
692static int x86_vector_select(struct irq_domain *d, struct irq_fwspec *fwspec,
693 enum irq_domain_bus_token bus_token)
694{
695 /*
696 * HPET and I/OAPIC cannot be parented in the vector domain
697 * if IRQ remapping is enabled. APIC IDs above 15 bits are
698 * only permitted if IRQ remapping is enabled, so check that.
699 */
700 if (apic_id_valid(apic_id: 32768))
701 return 0;
702
703 return x86_fwspec_is_ioapic(fwspec) || x86_fwspec_is_hpet(fwspec);
704}
705
706static const struct irq_domain_ops x86_vector_domain_ops = {
707 .select = x86_vector_select,
708 .alloc = x86_vector_alloc_irqs,
709 .free = x86_vector_free_irqs,
710 .activate = x86_vector_activate,
711 .deactivate = x86_vector_deactivate,
712#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
713 .debug_show = x86_vector_debug_show,
714#endif
715};
716
717int __init arch_probe_nr_irqs(void)
718{
719 int nr;
720
721 if (irq_get_nr_irqs() > NR_VECTORS * nr_cpu_ids)
722 irq_set_nr_irqs(NR_VECTORS * nr_cpu_ids);
723
724 nr = (gsi_top + nr_legacy_irqs()) + 8 * nr_cpu_ids;
725#if defined(CONFIG_PCI_MSI)
726 /*
727 * for MSI and HT dyn irq
728 */
729 if (gsi_top <= NR_IRQS_LEGACY)
730 nr += 8 * nr_cpu_ids;
731 else
732 nr += gsi_top * 16;
733#endif
734 if (nr < irq_get_nr_irqs())
735 irq_set_nr_irqs(nr);
736
737 /*
738 * We don't know if PIC is present at this point so we need to do
739 * probe() to get the right number of legacy IRQs.
740 */
741 return legacy_pic->probe();
742}
743
744void lapic_assign_legacy_vector(unsigned int irq, bool replace)
745{
746 /*
747 * Use assign system here so it won't get accounted as allocated
748 * and movable in the cpu hotplug check and it prevents managed
749 * irq reservation from touching it.
750 */
751 irq_matrix_assign_system(m: vector_matrix, ISA_IRQ_VECTOR(irq), replace);
752}
753
754void __init lapic_update_legacy_vectors(void)
755{
756 unsigned int i;
757
758 if (IS_ENABLED(CONFIG_X86_IO_APIC) && nr_ioapics > 0)
759 return;
760
761 /*
762 * If the IO/APIC is disabled via config, kernel command line or
763 * lack of enumeration then all legacy interrupts are routed
764 * through the PIC. Make sure that they are marked as legacy
765 * vectors. PIC_CASCADE_IRQ has already been marked in
766 * lapic_assign_system_vectors().
767 */
768 for (i = 0; i < nr_legacy_irqs(); i++) {
769 if (i != PIC_CASCADE_IR)
770 lapic_assign_legacy_vector(irq: i, replace: true);
771 }
772}
773
774void __init lapic_assign_system_vectors(void)
775{
776 unsigned int i, vector;
777
778 for_each_set_bit(vector, system_vectors, NR_VECTORS)
779 irq_matrix_assign_system(m: vector_matrix, bit: vector, replace: false);
780
781 if (nr_legacy_irqs() > 1)
782 lapic_assign_legacy_vector(PIC_CASCADE_IR, replace: false);
783
784 /* System vectors are reserved, online it */
785 irq_matrix_online(m: vector_matrix);
786
787 /* Mark the preallocated legacy interrupts */
788 for (i = 0; i < nr_legacy_irqs(); i++) {
789 /*
790 * Don't touch the cascade interrupt. It's unusable
791 * on PIC equipped machines. See the large comment
792 * in the IO/APIC code.
793 */
794 if (i != PIC_CASCADE_IR)
795 irq_matrix_assign(m: vector_matrix, ISA_IRQ_VECTOR(i));
796 }
797}
798
799int __init arch_early_irq_init(void)
800{
801 struct fwnode_handle *fn;
802
803 fn = irq_domain_alloc_named_fwnode(name: "VECTOR");
804 BUG_ON(!fn);
805 x86_vector_domain = irq_domain_create_tree(fwnode: fn, ops: &x86_vector_domain_ops,
806 NULL);
807 BUG_ON(x86_vector_domain == NULL);
808 irq_set_default_domain(domain: x86_vector_domain);
809
810 BUG_ON(!alloc_cpumask_var(&vector_searchmask, GFP_KERNEL));
811
812 /*
813 * Allocate the vector matrix allocator data structure and limit the
814 * search area.
815 */
816 vector_matrix = irq_alloc_matrix(NR_VECTORS, FIRST_EXTERNAL_VECTOR,
817 FIRST_SYSTEM_VECTOR);
818 BUG_ON(!vector_matrix);
819
820 return arch_early_ioapic_init();
821}
822
823#ifdef CONFIG_SMP
824
825static struct irq_desc *__setup_vector_irq(int vector)
826{
827 int isairq = vector - ISA_IRQ_VECTOR(0);
828
829 /* Check whether the irq is in the legacy space */
830 if (isairq < 0 || isairq >= nr_legacy_irqs())
831 return VECTOR_UNUSED;
832 /* Check whether the irq is handled by the IOAPIC */
833 if (test_bit(isairq, &io_apic_irqs))
834 return VECTOR_UNUSED;
835 return irq_to_desc(irq: isairq);
836}
837
838/* Online the local APIC infrastructure and initialize the vectors */
839void lapic_online(void)
840{
841 unsigned int vector;
842
843 lockdep_assert_held(&vector_lock);
844
845 /* Online the vector matrix array for this CPU */
846 irq_matrix_online(m: vector_matrix);
847
848 /*
849 * The interrupt affinity logic never targets interrupts to offline
850 * CPUs. The exception are the legacy PIC interrupts. In general
851 * they are only targeted to CPU0, but depending on the platform
852 * they can be distributed to any online CPU in hardware. The
853 * kernel has no influence on that. So all active legacy vectors
854 * must be installed on all CPUs. All non legacy interrupts can be
855 * cleared.
856 */
857 for (vector = 0; vector < NR_VECTORS; vector++)
858 this_cpu_write(vector_irq[vector], __setup_vector_irq(vector));
859}
860
861static void __vector_cleanup(struct vector_cleanup *cl, bool check_irr);
862
863void lapic_offline(void)
864{
865 struct vector_cleanup *cl = this_cpu_ptr(&vector_cleanup);
866
867 lock_vector_lock();
868
869 /* In case the vector cleanup timer has not expired */
870 __vector_cleanup(cl, check_irr: false);
871
872 irq_matrix_offline(m: vector_matrix);
873 WARN_ON_ONCE(timer_delete_sync_try(&cl->timer) < 0);
874 WARN_ON_ONCE(!hlist_empty(&cl->head));
875
876 unlock_vector_lock();
877}
878
879static int apic_set_affinity(struct irq_data *irqd,
880 const struct cpumask *dest, bool force)
881{
882 int err;
883
884 if (WARN_ON_ONCE(!irqd_is_activated(irqd)))
885 return -EIO;
886
887 raw_spin_lock(&vector_lock);
888 cpumask_and(dstp: vector_searchmask, src1p: dest, cpu_online_mask);
889 if (irqd_affinity_is_managed(d: irqd))
890 err = assign_managed_vector(irqd, dest: vector_searchmask);
891 else
892 err = assign_vector_locked(irqd, dest: vector_searchmask);
893 raw_spin_unlock(&vector_lock);
894 return err ? err : IRQ_SET_MASK_OK;
895}
896
897static void free_moved_vector(struct apic_chip_data *apicd)
898{
899 unsigned int vector = apicd->prev_vector;
900 unsigned int cpu = apicd->prev_cpu;
901 bool managed = apicd->is_managed;
902
903 /*
904 * Managed interrupts are usually not migrated away
905 * from an online CPU, but CPU isolation 'managed_irq'
906 * can make that happen.
907 * 1) Activation does not take the isolation into account
908 * to keep the code simple
909 * 2) Migration away from an isolated CPU can happen when
910 * a non-isolated CPU which is in the calculated
911 * affinity mask comes online.
912 */
913 trace_vector_free_moved(irq: apicd->irq, cpu, vector, is_managed: managed);
914 apic_free_vector(cpu, vector, managed);
915 per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED;
916 hlist_del_init(n: &apicd->clist);
917 apicd->prev_vector = 0;
918 apicd->move_in_progress = 0;
919}
920
921/*
922 * Called from fixup_irqs() with @desc->lock held and interrupts disabled.
923 */
924static void apic_force_complete_move(struct irq_data *irqd)
925{
926 unsigned int cpu = smp_processor_id();
927 struct apic_chip_data *apicd;
928 unsigned int vector;
929
930 guard(raw_spinlock)(l: &vector_lock);
931 apicd = apic_chip_data(irqd);
932 if (!apicd)
933 return;
934
935 /*
936 * If prev_vector is empty or the descriptor is neither currently
937 * nor previously on the outgoing CPU no action required.
938 */
939 vector = apicd->prev_vector;
940 if (!vector || (apicd->cpu != cpu && apicd->prev_cpu != cpu))
941 return;
942
943 /*
944 * This is tricky. If the cleanup of the old vector has not been
945 * done yet, then the following setaffinity call will fail with
946 * -EBUSY. This can leave the interrupt in a stale state.
947 *
948 * All CPUs are stuck in stop machine with interrupts disabled so
949 * calling __irq_complete_move() would be completely pointless.
950 *
951 * 1) The interrupt is in move_in_progress state. That means that we
952 * have not seen an interrupt since the io_apic was reprogrammed to
953 * the new vector.
954 *
955 * 2) The interrupt has fired on the new vector, but the cleanup IPIs
956 * have not been processed yet.
957 */
958 if (apicd->move_in_progress) {
959 /*
960 * In theory there is a race:
961 *
962 * set_ioapic(new_vector) <-- Interrupt is raised before update
963 * is effective, i.e. it's raised on
964 * the old vector.
965 *
966 * So if the target cpu cannot handle that interrupt before
967 * the old vector is cleaned up, we get a spurious interrupt
968 * and in the worst case the ioapic irq line becomes stale.
969 *
970 * But in case of cpu hotplug this should be a non issue
971 * because if the affinity update happens right before all
972 * cpus rendezvous in stop machine, there is no way that the
973 * interrupt can be blocked on the target cpu because all cpus
974 * loops first with interrupts enabled in stop machine, so the
975 * old vector is not yet cleaned up when the interrupt fires.
976 *
977 * So the only way to run into this issue is if the delivery
978 * of the interrupt on the apic/system bus would be delayed
979 * beyond the point where the target cpu disables interrupts
980 * in stop machine. I doubt that it can happen, but at least
981 * there is a theoretical chance. Virtualization might be
982 * able to expose this, but AFAICT the IOAPIC emulation is not
983 * as stupid as the real hardware.
984 *
985 * Anyway, there is nothing we can do about that at this point
986 * w/o refactoring the whole fixup_irq() business completely.
987 * We print at least the irq number and the old vector number,
988 * so we have the necessary information when a problem in that
989 * area arises.
990 */
991 pr_warn("IRQ fixup: irq %d move in progress, old vector %d\n",
992 irqd->irq, vector);
993 }
994 free_moved_vector(apicd);
995}
996
997#else
998# define apic_set_affinity NULL
999# define apic_force_complete_move NULL
1000#endif
1001
1002static int apic_retrigger_irq(struct irq_data *irqd)
1003{
1004 struct apic_chip_data *apicd = apic_chip_data(irqd);
1005 unsigned long flags;
1006
1007 raw_spin_lock_irqsave(&vector_lock, flags);
1008 __apic_send_IPI(cpu: apicd->cpu, vector: apicd->vector);
1009 raw_spin_unlock_irqrestore(&vector_lock, flags);
1010
1011 return 1;
1012}
1013
1014void apic_ack_irq(struct irq_data *irqd)
1015{
1016 irq_move_irq(data: irqd);
1017 apic_eoi();
1018}
1019
1020void apic_ack_edge(struct irq_data *irqd)
1021{
1022 irq_complete_move(cfg: irqd_cfg(irqd));
1023 apic_ack_irq(irqd);
1024}
1025
1026static void x86_vector_msi_compose_msg(struct irq_data *data,
1027 struct msi_msg *msg)
1028{
1029 __irq_msi_compose_msg(cfg: irqd_cfg(data), msg, dmar: false);
1030}
1031
1032static struct irq_chip lapic_controller = {
1033 .name = "APIC",
1034 .irq_ack = apic_ack_edge,
1035 .irq_set_affinity = apic_set_affinity,
1036 .irq_compose_msi_msg = x86_vector_msi_compose_msg,
1037 .irq_force_complete_move = apic_force_complete_move,
1038 .irq_retrigger = apic_retrigger_irq,
1039};
1040
1041#ifdef CONFIG_SMP
1042
1043static void __vector_cleanup(struct vector_cleanup *cl, bool check_irr)
1044{
1045 struct apic_chip_data *apicd;
1046 struct hlist_node *tmp;
1047 bool rearm = false;
1048
1049 lockdep_assert_held(&vector_lock);
1050
1051 hlist_for_each_entry_safe(apicd, tmp, &cl->head, clist) {
1052 unsigned int vector = apicd->prev_vector;
1053
1054 /*
1055 * Paranoia: Check if the vector that needs to be cleaned
1056 * up is registered at the APICs IRR. That's clearly a
1057 * hardware issue if the vector arrived on the old target
1058 * _after_ interrupts were disabled above. Keep @apicd
1059 * on the list and schedule the timer again to give the CPU
1060 * a chance to handle the pending interrupt.
1061 *
1062 * Do not check IRR when called from lapic_offline(), because
1063 * fixup_irqs() was just called to scan IRR for set bits and
1064 * forward them to new destination CPUs via IPIs.
1065 */
1066 if (check_irr && is_vector_pending(vector)) {
1067 pr_warn_once("Moved interrupt pending in old target APIC %u\n", apicd->irq);
1068 rearm = true;
1069 continue;
1070 }
1071 free_moved_vector(apicd);
1072 }
1073
1074 /*
1075 * Must happen under vector_lock to make the timer_pending() check
1076 * in __vector_schedule_cleanup() race free against the rearm here.
1077 */
1078 if (rearm)
1079 mod_timer(timer: &cl->timer, expires: jiffies + 1);
1080}
1081
1082static void vector_cleanup_callback(struct timer_list *tmr)
1083{
1084 struct vector_cleanup *cl = container_of(tmr, typeof(*cl), timer);
1085
1086 /* Prevent vectors vanishing under us */
1087 raw_spin_lock_irq(&vector_lock);
1088 __vector_cleanup(cl, check_irr: true);
1089 raw_spin_unlock_irq(&vector_lock);
1090}
1091
1092static void __vector_schedule_cleanup(struct apic_chip_data *apicd)
1093{
1094 unsigned int cpu = apicd->prev_cpu;
1095
1096 raw_spin_lock(&vector_lock);
1097 apicd->move_in_progress = 0;
1098 if (cpu_online(cpu)) {
1099 struct vector_cleanup *cl = per_cpu_ptr(&vector_cleanup, cpu);
1100
1101 hlist_add_head(n: &apicd->clist, h: &cl->head);
1102
1103 /*
1104 * The lockless timer_pending() check is safe here. If it
1105 * returns true, then the callback will observe this new
1106 * apic data in the hlist as everything is serialized by
1107 * vector lock.
1108 *
1109 * If it returns false then the timer is either not armed
1110 * or the other CPU executes the callback, which again
1111 * would be blocked on vector lock. Rearming it in the
1112 * latter case makes it fire for nothing.
1113 *
1114 * This is also safe against the callback rearming the timer
1115 * because that's serialized via vector lock too.
1116 */
1117 if (!timer_pending(timer: &cl->timer)) {
1118 cl->timer.expires = jiffies + 1;
1119 add_timer_on(timer: &cl->timer, cpu);
1120 }
1121 } else {
1122 pr_warn("IRQ %u schedule cleanup for offline CPU %u\n", apicd->irq, cpu);
1123 free_moved_vector(apicd);
1124 }
1125 raw_spin_unlock(&vector_lock);
1126}
1127
1128void vector_schedule_cleanup(struct irq_cfg *cfg)
1129{
1130 struct apic_chip_data *apicd;
1131
1132 apicd = container_of(cfg, struct apic_chip_data, hw_irq_cfg);
1133 if (apicd->move_in_progress)
1134 __vector_schedule_cleanup(apicd);
1135}
1136
1137void irq_complete_move(struct irq_cfg *cfg)
1138{
1139 struct apic_chip_data *apicd;
1140
1141 apicd = container_of(cfg, struct apic_chip_data, hw_irq_cfg);
1142 if (likely(!apicd->move_in_progress))
1143 return;
1144
1145 /*
1146 * If the interrupt arrived on the new target CPU, cleanup the
1147 * vector on the old target CPU. A vector check is not required
1148 * because an interrupt can never move from one vector to another
1149 * on the same CPU.
1150 */
1151 if (apicd->cpu == smp_processor_id())
1152 __vector_schedule_cleanup(apicd);
1153}
1154
1155#ifdef CONFIG_HOTPLUG_CPU
1156/*
1157 * Note, this is not accurate accounting, but at least good enough to
1158 * prevent that the actual interrupt move will run out of vectors.
1159 */
1160int lapic_can_unplug_cpu(void)
1161{
1162 unsigned int rsvd, avl, tomove, cpu = smp_processor_id();
1163 int ret = 0;
1164
1165 raw_spin_lock(&vector_lock);
1166 tomove = irq_matrix_allocated(m: vector_matrix);
1167 avl = irq_matrix_available(m: vector_matrix, cpudown: true);
1168 if (avl < tomove) {
1169 pr_warn("CPU %u has %u vectors, %u available. Cannot disable CPU\n",
1170 cpu, tomove, avl);
1171 ret = -ENOSPC;
1172 goto out;
1173 }
1174 rsvd = irq_matrix_reserved(m: vector_matrix);
1175 if (avl < rsvd) {
1176 pr_warn("Reserved vectors %u > available %u. IRQ request may fail\n",
1177 rsvd, avl);
1178 }
1179out:
1180 raw_spin_unlock(&vector_lock);
1181 return ret;
1182}
1183#endif /* HOTPLUG_CPU */
1184#endif /* SMP */
1185
1186static void __init print_APIC_field(int base)
1187{
1188 int i;
1189
1190 printk(KERN_DEBUG);
1191
1192 for (i = 0; i < 8; i++)
1193 pr_cont("%08x", apic_read(base + i*0x10));
1194
1195 pr_cont("\n");
1196}
1197
1198static void __init print_local_APIC(void *dummy)
1199{
1200 unsigned int i, v, ver, maxlvt;
1201 u64 icr;
1202
1203 pr_debug("printing local APIC contents on CPU#%d/%d:\n",
1204 smp_processor_id(), read_apic_id());
1205 v = apic_read(APIC_ID);
1206 pr_info("... APIC ID: %08x (%01x)\n", v, read_apic_id());
1207 v = apic_read(APIC_LVR);
1208 pr_info("... APIC VERSION: %08x\n", v);
1209 ver = GET_APIC_VERSION(v);
1210 maxlvt = lapic_get_maxlvt();
1211
1212 v = apic_read(APIC_TASKPRI);
1213 pr_debug("... APIC TASKPRI: %08x (%02x)\n", v, v & APIC_TPRI_MASK);
1214
1215 /* !82489DX */
1216 if (APIC_INTEGRATED(ver)) {
1217 if (!APIC_XAPIC(ver)) {
1218 v = apic_read(APIC_ARBPRI);
1219 pr_debug("... APIC ARBPRI: %08x (%02x)\n",
1220 v, v & APIC_ARBPRI_MASK);
1221 }
1222 v = apic_read(APIC_PROCPRI);
1223 pr_debug("... APIC PROCPRI: %08x\n", v);
1224 }
1225
1226 /*
1227 * Remote read supported only in the 82489DX and local APIC for
1228 * Pentium processors.
1229 */
1230 if (!APIC_INTEGRATED(ver) || maxlvt == 3) {
1231 v = apic_read(APIC_RRR);
1232 pr_debug("... APIC RRR: %08x\n", v);
1233 }
1234
1235 v = apic_read(APIC_LDR);
1236 pr_debug("... APIC LDR: %08x\n", v);
1237 if (!x2apic_enabled()) {
1238 v = apic_read(APIC_DFR);
1239 pr_debug("... APIC DFR: %08x\n", v);
1240 }
1241 v = apic_read(APIC_SPIV);
1242 pr_debug("... APIC SPIV: %08x\n", v);
1243
1244 pr_debug("... APIC ISR field:\n");
1245 print_APIC_field(APIC_ISR);
1246 pr_debug("... APIC TMR field:\n");
1247 print_APIC_field(APIC_TMR);
1248 pr_debug("... APIC IRR field:\n");
1249 print_APIC_field(APIC_IRR);
1250
1251 /* !82489DX */
1252 if (APIC_INTEGRATED(ver)) {
1253 /* Due to the Pentium erratum 3AP. */
1254 if (maxlvt > 3)
1255 apic_write(APIC_ESR, val: 0);
1256
1257 v = apic_read(APIC_ESR);
1258 pr_debug("... APIC ESR: %08x\n", v);
1259 }
1260
1261 icr = apic_icr_read();
1262 pr_debug("... APIC ICR: %08x\n", (u32)icr);
1263 pr_debug("... APIC ICR2: %08x\n", (u32)(icr >> 32));
1264
1265 v = apic_read(APIC_LVTT);
1266 pr_debug("... APIC LVTT: %08x\n", v);
1267
1268 if (maxlvt > 3) {
1269 /* PC is LVT#4. */
1270 v = apic_read(APIC_LVTPC);
1271 pr_debug("... APIC LVTPC: %08x\n", v);
1272 }
1273 v = apic_read(APIC_LVT0);
1274 pr_debug("... APIC LVT0: %08x\n", v);
1275 v = apic_read(APIC_LVT1);
1276 pr_debug("... APIC LVT1: %08x\n", v);
1277
1278 if (maxlvt > 2) {
1279 /* ERR is LVT#3. */
1280 v = apic_read(APIC_LVTERR);
1281 pr_debug("... APIC LVTERR: %08x\n", v);
1282 }
1283
1284 v = apic_read(APIC_TMICT);
1285 pr_debug("... APIC TMICT: %08x\n", v);
1286 v = apic_read(APIC_TMCCT);
1287 pr_debug("... APIC TMCCT: %08x\n", v);
1288 v = apic_read(APIC_TDCR);
1289 pr_debug("... APIC TDCR: %08x\n", v);
1290
1291 if (boot_cpu_has(X86_FEATURE_EXTAPIC)) {
1292 v = apic_read(APIC_EFEAT);
1293 maxlvt = (v >> 16) & 0xff;
1294 pr_debug("... APIC EFEAT: %08x\n", v);
1295 v = apic_read(APIC_ECTRL);
1296 pr_debug("... APIC ECTRL: %08x\n", v);
1297 for (i = 0; i < maxlvt; i++) {
1298 v = apic_read(APIC_EILVTn(i));
1299 pr_debug("... APIC EILVT%d: %08x\n", i, v);
1300 }
1301 }
1302 pr_cont("\n");
1303}
1304
1305static void __init print_local_APICs(int maxcpu)
1306{
1307 int cpu;
1308
1309 if (!maxcpu)
1310 return;
1311
1312 preempt_disable();
1313 for_each_online_cpu(cpu) {
1314 if (cpu >= maxcpu)
1315 break;
1316 smp_call_function_single(cpuid: cpu, func: print_local_APIC, NULL, wait: 1);
1317 }
1318 preempt_enable();
1319}
1320
1321static void __init print_PIC(void)
1322{
1323 unsigned int v;
1324 unsigned long flags;
1325
1326 if (!nr_legacy_irqs())
1327 return;
1328
1329 pr_debug("\nprinting PIC contents\n");
1330
1331 raw_spin_lock_irqsave(&i8259A_lock, flags);
1332
1333 v = inb(port: 0xa1) << 8 | inb(port: 0x21);
1334 pr_debug("... PIC IMR: %04x\n", v);
1335
1336 v = inb(port: 0xa0) << 8 | inb(port: 0x20);
1337 pr_debug("... PIC IRR: %04x\n", v);
1338
1339 outb(value: 0x0b, port: 0xa0);
1340 outb(value: 0x0b, port: 0x20);
1341 v = inb(port: 0xa0) << 8 | inb(port: 0x20);
1342 outb(value: 0x0a, port: 0xa0);
1343 outb(value: 0x0a, port: 0x20);
1344
1345 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
1346
1347 pr_debug("... PIC ISR: %04x\n", v);
1348
1349 v = inb(PIC_ELCR2) << 8 | inb(PIC_ELCR1);
1350 pr_debug("... PIC ELCR: %04x\n", v);
1351}
1352
1353static int show_lapic __initdata = 1;
1354static __init int setup_show_lapic(char *arg)
1355{
1356 int num = -1;
1357
1358 if (strcmp(arg, "all") == 0) {
1359 show_lapic = CONFIG_NR_CPUS;
1360 } else {
1361 get_option(str: &arg, pint: &num);
1362 if (num >= 0)
1363 show_lapic = num;
1364 }
1365
1366 return 1;
1367}
1368__setup("show_lapic=", setup_show_lapic);
1369
1370static int __init print_ICs(void)
1371{
1372 if (apic_verbosity == APIC_QUIET)
1373 return 0;
1374
1375 print_PIC();
1376
1377 /* don't print out if apic is not there */
1378 if (!boot_cpu_has(X86_FEATURE_APIC) && !apic_from_smp_config())
1379 return 0;
1380
1381 print_local_APICs(maxcpu: show_lapic);
1382 print_IO_APICs();
1383
1384 return 0;
1385}
1386
1387late_initcall(print_ICs);
1388

source code of linux/arch/x86/kernel/apic/vector.c