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 static DEFINE_RAW_SPINLOCK(vector_lock);
33 static cpumask_var_t vector_cpumask, vector_searchmask, searched_cpumask;
34 static struct irq_chip lapic_controller;
35 #ifdef CONFIG_X86_IO_APIC
36 static struct apic_chip_data *legacy_irq_data[NR_IRQS_LEGACY];
37 #endif
38
lock_vector_lock(void)39 void lock_vector_lock(void)
40 {
41 /* Used to the online set of cpus does not change
42 * during assign_irq_vector.
43 */
44 raw_spin_lock(&vector_lock);
45 }
46
unlock_vector_lock(void)47 void unlock_vector_lock(void)
48 {
49 raw_spin_unlock(&vector_lock);
50 }
51
apic_chip_data(struct irq_data * irq_data)52 static struct apic_chip_data *apic_chip_data(struct irq_data *irq_data)
53 {
54 if (!irq_data)
55 return NULL;
56
57 while (irq_data->parent_data)
58 irq_data = irq_data->parent_data;
59
60 return irq_data->chip_data;
61 }
62
irqd_cfg(struct irq_data * irq_data)63 struct irq_cfg *irqd_cfg(struct irq_data *irq_data)
64 {
65 struct apic_chip_data *data = apic_chip_data(irq_data);
66
67 return data ? &data->cfg : NULL;
68 }
69
irq_cfg(unsigned int irq)70 struct irq_cfg *irq_cfg(unsigned int irq)
71 {
72 return irqd_cfg(irq_get_irq_data(irq));
73 }
74
alloc_apic_chip_data(int node)75 static struct apic_chip_data *alloc_apic_chip_data(int node)
76 {
77 struct apic_chip_data *data;
78
79 data = kzalloc_node(sizeof(*data), GFP_KERNEL, node);
80 if (!data)
81 return NULL;
82 if (!zalloc_cpumask_var_node(&data->domain, GFP_KERNEL, node))
83 goto out_data;
84 if (!zalloc_cpumask_var_node(&data->old_domain, GFP_KERNEL, node))
85 goto out_domain;
86 return data;
87 out_domain:
88 free_cpumask_var(data->domain);
89 out_data:
90 kfree(data);
91 return NULL;
92 }
93
free_apic_chip_data(unsigned int virq,struct apic_chip_data * data)94 static void free_apic_chip_data(unsigned int virq, struct apic_chip_data *data)
95 {
96 #ifdef CONFIG_X86_IO_APIC
97 if (virq < nr_legacy_irqs())
98 legacy_irq_data[virq] = NULL;
99 #endif
100 if (data) {
101 free_cpumask_var(data->domain);
102 free_cpumask_var(data->old_domain);
103 kfree(data);
104 }
105 }
106
__assign_irq_vector(int irq,struct apic_chip_data * d,const struct cpumask * mask)107 static int __assign_irq_vector(int irq, struct apic_chip_data *d,
108 const struct cpumask *mask)
109 {
110 /*
111 * NOTE! The local APIC isn't very good at handling
112 * multiple interrupts at the same interrupt level.
113 * As the interrupt level is determined by taking the
114 * vector number and shifting that right by 4, we
115 * want to spread these out a bit so that they don't
116 * all fall in the same interrupt level.
117 *
118 * Also, we've got to be careful not to trash gate
119 * 0x80, because int 0x80 is hm, kind of importantish. ;)
120 */
121 static int current_vector = FIRST_EXTERNAL_VECTOR + VECTOR_OFFSET_START;
122 static int current_offset = VECTOR_OFFSET_START % 16;
123 int cpu, vector;
124
125 /*
126 * If there is still a move in progress or the previous move has not
127 * been cleaned up completely, tell the caller to come back later.
128 */
129 if (d->move_in_progress ||
130 cpumask_intersects(d->old_domain, cpu_online_mask))
131 return -EBUSY;
132
133 /* Only try and allocate irqs on cpus that are present */
134 cpumask_clear(d->old_domain);
135 cpumask_clear(searched_cpumask);
136 cpu = cpumask_first_and(mask, cpu_online_mask);
137 while (cpu < nr_cpu_ids) {
138 int new_cpu, offset;
139
140 /* Get the possible target cpus for @mask/@cpu from the apic */
141 apic->vector_allocation_domain(cpu, vector_cpumask, mask);
142
143 /*
144 * Clear the offline cpus from @vector_cpumask for searching
145 * and verify whether the result overlaps with @mask. If true,
146 * then the call to apic->cpu_mask_to_apicid_and() will
147 * succeed as well. If not, no point in trying to find a
148 * vector in this mask.
149 */
150 cpumask_and(vector_searchmask, vector_cpumask, cpu_online_mask);
151 if (!cpumask_intersects(vector_searchmask, mask))
152 goto next_cpu;
153
154 if (cpumask_subset(vector_cpumask, d->domain)) {
155 if (cpumask_equal(vector_cpumask, d->domain))
156 goto success;
157 /*
158 * Mark the cpus which are not longer in the mask for
159 * cleanup.
160 */
161 cpumask_andnot(d->old_domain, d->domain, vector_cpumask);
162 vector = d->cfg.vector;
163 goto update;
164 }
165
166 vector = current_vector;
167 offset = current_offset;
168 next:
169 vector += 16;
170 if (vector >= first_system_vector) {
171 offset = (offset + 1) % 16;
172 vector = FIRST_EXTERNAL_VECTOR + offset;
173 }
174
175 /* If the search wrapped around, try the next cpu */
176 if (unlikely(current_vector == vector))
177 goto next_cpu;
178
179 if (test_bit(vector, used_vectors))
180 goto next;
181
182 for_each_cpu(new_cpu, vector_searchmask) {
183 if (!IS_ERR_OR_NULL(per_cpu(vector_irq, new_cpu)[vector]))
184 goto next;
185 }
186 /* Found one! */
187 current_vector = vector;
188 current_offset = offset;
189 /* Schedule the old vector for cleanup on all cpus */
190 if (d->cfg.vector)
191 cpumask_copy(d->old_domain, d->domain);
192 for_each_cpu(new_cpu, vector_searchmask)
193 per_cpu(vector_irq, new_cpu)[vector] = irq_to_desc(irq);
194 goto update;
195
196 next_cpu:
197 /*
198 * We exclude the current @vector_cpumask from the requested
199 * @mask and try again with the next online cpu in the
200 * result. We cannot modify @mask, so we use @vector_cpumask
201 * as a temporary buffer here as it will be reassigned when
202 * calling apic->vector_allocation_domain() above.
203 */
204 cpumask_or(searched_cpumask, searched_cpumask, vector_cpumask);
205 cpumask_andnot(vector_cpumask, mask, searched_cpumask);
206 cpu = cpumask_first_and(vector_cpumask, cpu_online_mask);
207 continue;
208 }
209 return -ENOSPC;
210
211 update:
212 /*
213 * Exclude offline cpus from the cleanup mask and set the
214 * move_in_progress flag when the result is not empty.
215 */
216 cpumask_and(d->old_domain, d->old_domain, cpu_online_mask);
217 d->move_in_progress = !cpumask_empty(d->old_domain);
218 d->cfg.old_vector = d->move_in_progress ? d->cfg.vector : 0;
219 d->cfg.vector = vector;
220 cpumask_copy(d->domain, vector_cpumask);
221 success:
222 /*
223 * Cache destination APIC IDs into cfg->dest_apicid. This cannot fail
224 * as we already established, that mask & d->domain & cpu_online_mask
225 * is not empty.
226 */
227 BUG_ON(apic->cpu_mask_to_apicid_and(mask, d->domain,
228 &d->cfg.dest_apicid));
229 return 0;
230 }
231
assign_irq_vector(int irq,struct apic_chip_data * data,const struct cpumask * mask)232 static int assign_irq_vector(int irq, struct apic_chip_data *data,
233 const struct cpumask *mask)
234 {
235 int err;
236 unsigned long flags;
237
238 raw_spin_lock_irqsave(&vector_lock, flags);
239 err = __assign_irq_vector(irq, data, mask);
240 raw_spin_unlock_irqrestore(&vector_lock, flags);
241 return err;
242 }
243
assign_irq_vector_policy(int irq,int node,struct apic_chip_data * data,struct irq_alloc_info * info)244 static int assign_irq_vector_policy(int irq, int node,
245 struct apic_chip_data *data,
246 struct irq_alloc_info *info)
247 {
248 if (info && info->mask)
249 return assign_irq_vector(irq, data, info->mask);
250 if (node != NUMA_NO_NODE &&
251 assign_irq_vector(irq, data, cpumask_of_node(node)) == 0)
252 return 0;
253 return assign_irq_vector(irq, data, apic->target_cpus());
254 }
255
clear_irq_vector(int irq,struct apic_chip_data * data)256 static void clear_irq_vector(int irq, struct apic_chip_data *data)
257 {
258 struct irq_desc *desc;
259 int cpu, vector;
260
261 if (!data->cfg.vector)
262 return;
263
264 vector = data->cfg.vector;
265 for_each_cpu_and(cpu, data->domain, cpu_online_mask)
266 per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED;
267
268 data->cfg.vector = 0;
269 cpumask_clear(data->domain);
270
271 /*
272 * If move is in progress or the old_domain mask is not empty,
273 * i.e. the cleanup IPI has not been processed yet, we need to remove
274 * the old references to desc from all cpus vector tables.
275 */
276 if (!data->move_in_progress && cpumask_empty(data->old_domain))
277 return;
278
279 desc = irq_to_desc(irq);
280 for_each_cpu_and(cpu, data->old_domain, cpu_online_mask) {
281 for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS;
282 vector++) {
283 if (per_cpu(vector_irq, cpu)[vector] != desc)
284 continue;
285 per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED;
286 break;
287 }
288 }
289 data->move_in_progress = 0;
290 }
291
init_irq_alloc_info(struct irq_alloc_info * info,const struct cpumask * mask)292 void init_irq_alloc_info(struct irq_alloc_info *info,
293 const struct cpumask *mask)
294 {
295 memset(info, 0, sizeof(*info));
296 info->mask = mask;
297 }
298
copy_irq_alloc_info(struct irq_alloc_info * dst,struct irq_alloc_info * src)299 void copy_irq_alloc_info(struct irq_alloc_info *dst, struct irq_alloc_info *src)
300 {
301 if (src)
302 *dst = *src;
303 else
304 memset(dst, 0, sizeof(*dst));
305 }
306
x86_vector_free_irqs(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs)307 static void x86_vector_free_irqs(struct irq_domain *domain,
308 unsigned int virq, unsigned int nr_irqs)
309 {
310 struct apic_chip_data *apic_data;
311 struct irq_data *irq_data;
312 unsigned long flags;
313 int i;
314
315 for (i = 0; i < nr_irqs; i++) {
316 irq_data = irq_domain_get_irq_data(x86_vector_domain, virq + i);
317 if (irq_data && irq_data->chip_data) {
318 raw_spin_lock_irqsave(&vector_lock, flags);
319 clear_irq_vector(virq + i, irq_data->chip_data);
320 apic_data = irq_data->chip_data;
321 irq_domain_reset_irq_data(irq_data);
322 raw_spin_unlock_irqrestore(&vector_lock, flags);
323 free_apic_chip_data(virq + i, apic_data);
324 }
325 }
326 }
327
x86_vector_alloc_irqs(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * arg)328 static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq,
329 unsigned int nr_irqs, void *arg)
330 {
331 struct irq_alloc_info *info = arg;
332 struct apic_chip_data *data;
333 struct irq_data *irq_data;
334 int i, err, node;
335
336 if (disable_apic)
337 return -ENXIO;
338
339 /* Currently vector allocator can't guarantee contiguous allocations */
340 if ((info->flags & X86_IRQ_ALLOC_CONTIGUOUS_VECTORS) && nr_irqs > 1)
341 return -ENOSYS;
342
343 for (i = 0; i < nr_irqs; i++) {
344 irq_data = irq_domain_get_irq_data(domain, virq + i);
345 BUG_ON(!irq_data);
346 node = irq_data_get_node(irq_data);
347 #ifdef CONFIG_X86_IO_APIC
348 if (virq + i < nr_legacy_irqs() && legacy_irq_data[virq + i])
349 data = legacy_irq_data[virq + i];
350 else
351 #endif
352 data = alloc_apic_chip_data(node);
353 if (!data) {
354 err = -ENOMEM;
355 goto error;
356 }
357
358 irq_data->chip = &lapic_controller;
359 irq_data->chip_data = data;
360 irq_data->hwirq = virq + i;
361 err = assign_irq_vector_policy(virq + i, node, data, info);
362 if (err) {
363 irq_data->chip_data = NULL;
364 free_apic_chip_data(virq + i, data);
365 goto error;
366 }
367 }
368
369 return 0;
370
371 error:
372 x86_vector_free_irqs(domain, virq, i);
373 return err;
374 }
375
376 static const struct irq_domain_ops x86_vector_domain_ops = {
377 .alloc = x86_vector_alloc_irqs,
378 .free = x86_vector_free_irqs,
379 };
380
arch_probe_nr_irqs(void)381 int __init arch_probe_nr_irqs(void)
382 {
383 int nr;
384
385 if (nr_irqs > (NR_VECTORS * nr_cpu_ids))
386 nr_irqs = NR_VECTORS * nr_cpu_ids;
387
388 nr = (gsi_top + nr_legacy_irqs()) + 8 * nr_cpu_ids;
389 #if defined(CONFIG_PCI_MSI) || defined(CONFIG_HT_IRQ)
390 /*
391 * for MSI and HT dyn irq
392 */
393 if (gsi_top <= NR_IRQS_LEGACY)
394 nr += 8 * nr_cpu_ids;
395 else
396 nr += gsi_top * 16;
397 #endif
398 if (nr < nr_irqs)
399 nr_irqs = nr;
400
401 /*
402 * We don't know if PIC is present at this point so we need to do
403 * probe() to get the right number of legacy IRQs.
404 */
405 return legacy_pic->probe();
406 }
407
408 #ifdef CONFIG_X86_IO_APIC
init_legacy_irqs(void)409 static void init_legacy_irqs(void)
410 {
411 int i, node = cpu_to_node(0);
412 struct apic_chip_data *data;
413
414 /*
415 * For legacy IRQ's, start with assigning irq0 to irq15 to
416 * ISA_IRQ_VECTOR(i) for all cpu's.
417 */
418 for (i = 0; i < nr_legacy_irqs(); i++) {
419 data = legacy_irq_data[i] = alloc_apic_chip_data(node);
420 BUG_ON(!data);
421
422 data->cfg.vector = ISA_IRQ_VECTOR(i);
423 cpumask_setall(data->domain);
424 irq_set_chip_data(i, data);
425 }
426 }
427 #else
init_legacy_irqs(void)428 static void init_legacy_irqs(void) { }
429 #endif
430
arch_early_irq_init(void)431 int __init arch_early_irq_init(void)
432 {
433 init_legacy_irqs();
434
435 x86_vector_domain = irq_domain_add_tree(NULL, &x86_vector_domain_ops,
436 NULL);
437 BUG_ON(x86_vector_domain == NULL);
438 irq_set_default_host(x86_vector_domain);
439
440 arch_init_msi_domain(x86_vector_domain);
441 arch_init_htirq_domain(x86_vector_domain);
442
443 BUG_ON(!alloc_cpumask_var(&vector_cpumask, GFP_KERNEL));
444 BUG_ON(!alloc_cpumask_var(&vector_searchmask, GFP_KERNEL));
445 BUG_ON(!alloc_cpumask_var(&searched_cpumask, GFP_KERNEL));
446
447 return arch_early_ioapic_init();
448 }
449
450 /* Initialize vector_irq on a new cpu */
__setup_vector_irq(int cpu)451 static void __setup_vector_irq(int cpu)
452 {
453 struct apic_chip_data *data;
454 struct irq_desc *desc;
455 int irq, vector;
456
457 /* Mark the inuse vectors */
458 for_each_irq_desc(irq, desc) {
459 struct irq_data *idata = irq_desc_get_irq_data(desc);
460
461 data = apic_chip_data(idata);
462 if (!data || !cpumask_test_cpu(cpu, data->domain))
463 continue;
464 vector = data->cfg.vector;
465 per_cpu(vector_irq, cpu)[vector] = desc;
466 }
467 /* Mark the free vectors */
468 for (vector = 0; vector < NR_VECTORS; ++vector) {
469 desc = per_cpu(vector_irq, cpu)[vector];
470 if (IS_ERR_OR_NULL(desc))
471 continue;
472
473 data = apic_chip_data(irq_desc_get_irq_data(desc));
474 if (!cpumask_test_cpu(cpu, data->domain))
475 per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED;
476 }
477 }
478
479 /*
480 * Setup the vector to irq mappings. Must be called with vector_lock held.
481 */
setup_vector_irq(int cpu)482 void setup_vector_irq(int cpu)
483 {
484 int irq;
485
486 lockdep_assert_held(&vector_lock);
487 /*
488 * On most of the platforms, legacy PIC delivers the interrupts on the
489 * boot cpu. But there are certain platforms where PIC interrupts are
490 * delivered to multiple cpu's. If the legacy IRQ is handled by the
491 * legacy PIC, for the new cpu that is coming online, setup the static
492 * legacy vector to irq mapping:
493 */
494 for (irq = 0; irq < nr_legacy_irqs(); irq++)
495 per_cpu(vector_irq, cpu)[ISA_IRQ_VECTOR(irq)] = irq_to_desc(irq);
496
497 __setup_vector_irq(cpu);
498 }
499
apic_retrigger_irq(struct irq_data * irq_data)500 static int apic_retrigger_irq(struct irq_data *irq_data)
501 {
502 struct apic_chip_data *data = apic_chip_data(irq_data);
503 unsigned long flags;
504 int cpu;
505
506 raw_spin_lock_irqsave(&vector_lock, flags);
507 cpu = cpumask_first_and(data->domain, cpu_online_mask);
508 apic->send_IPI_mask(cpumask_of(cpu), data->cfg.vector);
509 raw_spin_unlock_irqrestore(&vector_lock, flags);
510
511 return 1;
512 }
513
apic_ack_edge(struct irq_data * data)514 void apic_ack_edge(struct irq_data *data)
515 {
516 irq_complete_move(irqd_cfg(data));
517 irq_move_irq(data);
518 ack_APIC_irq();
519 }
520
apic_set_affinity(struct irq_data * irq_data,const struct cpumask * dest,bool force)521 static int apic_set_affinity(struct irq_data *irq_data,
522 const struct cpumask *dest, bool force)
523 {
524 struct apic_chip_data *data = irq_data->chip_data;
525 int err, irq = irq_data->irq;
526
527 if (!config_enabled(CONFIG_SMP))
528 return -EPERM;
529
530 if (!cpumask_intersects(dest, cpu_online_mask))
531 return -EINVAL;
532
533 err = assign_irq_vector(irq, data, dest);
534 return err ? err : IRQ_SET_MASK_OK;
535 }
536
537 static struct irq_chip lapic_controller = {
538 .irq_ack = apic_ack_edge,
539 .irq_set_affinity = apic_set_affinity,
540 .irq_retrigger = apic_retrigger_irq,
541 };
542
543 #ifdef CONFIG_SMP
__send_cleanup_vector(struct apic_chip_data * data)544 static void __send_cleanup_vector(struct apic_chip_data *data)
545 {
546 raw_spin_lock(&vector_lock);
547 cpumask_and(data->old_domain, data->old_domain, cpu_online_mask);
548 data->move_in_progress = 0;
549 if (!cpumask_empty(data->old_domain))
550 apic->send_IPI_mask(data->old_domain, IRQ_MOVE_CLEANUP_VECTOR);
551 raw_spin_unlock(&vector_lock);
552 }
553
send_cleanup_vector(struct irq_cfg * cfg)554 void send_cleanup_vector(struct irq_cfg *cfg)
555 {
556 struct apic_chip_data *data;
557
558 data = container_of(cfg, struct apic_chip_data, cfg);
559 if (data->move_in_progress)
560 __send_cleanup_vector(data);
561 }
562
smp_irq_move_cleanup_interrupt(void)563 asmlinkage __visible void smp_irq_move_cleanup_interrupt(void)
564 {
565 unsigned vector, me;
566
567 entering_ack_irq();
568
569 /* Prevent vectors vanishing under us */
570 raw_spin_lock(&vector_lock);
571
572 me = smp_processor_id();
573 for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
574 struct apic_chip_data *data;
575 struct irq_desc *desc;
576 unsigned int irr;
577
578 retry:
579 desc = __this_cpu_read(vector_irq[vector]);
580 if (IS_ERR_OR_NULL(desc))
581 continue;
582
583 if (!raw_spin_trylock(&desc->lock)) {
584 raw_spin_unlock(&vector_lock);
585 cpu_relax();
586 raw_spin_lock(&vector_lock);
587 goto retry;
588 }
589
590 data = apic_chip_data(irq_desc_get_irq_data(desc));
591 if (!data)
592 goto unlock;
593
594 /*
595 * Nothing to cleanup if irq migration is in progress
596 * or this cpu is not set in the cleanup mask.
597 */
598 if (data->move_in_progress ||
599 !cpumask_test_cpu(me, data->old_domain))
600 goto unlock;
601
602 /*
603 * We have two cases to handle here:
604 * 1) vector is unchanged but the target mask got reduced
605 * 2) vector and the target mask has changed
606 *
607 * #1 is obvious, but in #2 we have two vectors with the same
608 * irq descriptor: the old and the new vector. So we need to
609 * make sure that we only cleanup the old vector. The new
610 * vector has the current @vector number in the config and
611 * this cpu is part of the target mask. We better leave that
612 * one alone.
613 */
614 if (vector == data->cfg.vector &&
615 cpumask_test_cpu(me, data->domain))
616 goto unlock;
617
618 irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
619 /*
620 * Check if the vector that needs to be cleanedup is
621 * registered at the cpu's IRR. If so, then this is not
622 * the best time to clean it up. Lets clean it up in the
623 * next attempt by sending another IRQ_MOVE_CLEANUP_VECTOR
624 * to myself.
625 */
626 if (irr & (1 << (vector % 32))) {
627 apic->send_IPI_self(IRQ_MOVE_CLEANUP_VECTOR);
628 goto unlock;
629 }
630 __this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
631 cpumask_clear_cpu(me, data->old_domain);
632 unlock:
633 raw_spin_unlock(&desc->lock);
634 }
635
636 raw_spin_unlock(&vector_lock);
637
638 exiting_irq();
639 }
640
__irq_complete_move(struct irq_cfg * cfg,unsigned vector)641 static void __irq_complete_move(struct irq_cfg *cfg, unsigned vector)
642 {
643 unsigned me;
644 struct apic_chip_data *data;
645
646 data = container_of(cfg, struct apic_chip_data, cfg);
647 if (likely(!data->move_in_progress))
648 return;
649
650 me = smp_processor_id();
651 if (vector == data->cfg.vector && cpumask_test_cpu(me, data->domain))
652 __send_cleanup_vector(data);
653 }
654
irq_complete_move(struct irq_cfg * cfg)655 void irq_complete_move(struct irq_cfg *cfg)
656 {
657 __irq_complete_move(cfg, ~get_irq_regs()->orig_ax);
658 }
659
660 /*
661 * Called from fixup_irqs() with @desc->lock held and interrupts disabled.
662 */
irq_force_complete_move(struct irq_desc * desc)663 void irq_force_complete_move(struct irq_desc *desc)
664 {
665 struct irq_data *irqdata;
666 struct apic_chip_data *data;
667 struct irq_cfg *cfg;
668 unsigned int cpu;
669
670 /*
671 * The function is called for all descriptors regardless of which
672 * irqdomain they belong to. For example if an IRQ is provided by
673 * an irq_chip as part of a GPIO driver, the chip data for that
674 * descriptor is specific to the irq_chip in question.
675 *
676 * Check first that the chip_data is what we expect
677 * (apic_chip_data) before touching it any further.
678 */
679 irqdata = irq_domain_get_irq_data(x86_vector_domain,
680 irq_desc_get_irq(desc));
681 if (!irqdata)
682 return;
683
684 data = apic_chip_data(irqdata);
685 cfg = data ? &data->cfg : NULL;
686
687 if (!cfg)
688 return;
689
690 /*
691 * This is tricky. If the cleanup of @data->old_domain has not been
692 * done yet, then the following setaffinity call will fail with
693 * -EBUSY. This can leave the interrupt in a stale state.
694 *
695 * All CPUs are stuck in stop machine with interrupts disabled so
696 * calling __irq_complete_move() would be completely pointless.
697 */
698 raw_spin_lock(&vector_lock);
699 /*
700 * Clean out all offline cpus (including the outgoing one) from the
701 * old_domain mask.
702 */
703 cpumask_and(data->old_domain, data->old_domain, cpu_online_mask);
704
705 /*
706 * If move_in_progress is cleared and the old_domain mask is empty,
707 * then there is nothing to cleanup. fixup_irqs() will take care of
708 * the stale vectors on the outgoing cpu.
709 */
710 if (!data->move_in_progress && cpumask_empty(data->old_domain)) {
711 raw_spin_unlock(&vector_lock);
712 return;
713 }
714
715 /*
716 * 1) The interrupt is in move_in_progress state. That means that we
717 * have not seen an interrupt since the io_apic was reprogrammed to
718 * the new vector.
719 *
720 * 2) The interrupt has fired on the new vector, but the cleanup IPIs
721 * have not been processed yet.
722 */
723 if (data->move_in_progress) {
724 /*
725 * In theory there is a race:
726 *
727 * set_ioapic(new_vector) <-- Interrupt is raised before update
728 * is effective, i.e. it's raised on
729 * the old vector.
730 *
731 * So if the target cpu cannot handle that interrupt before
732 * the old vector is cleaned up, we get a spurious interrupt
733 * and in the worst case the ioapic irq line becomes stale.
734 *
735 * But in case of cpu hotplug this should be a non issue
736 * because if the affinity update happens right before all
737 * cpus rendevouz in stop machine, there is no way that the
738 * interrupt can be blocked on the target cpu because all cpus
739 * loops first with interrupts enabled in stop machine, so the
740 * old vector is not yet cleaned up when the interrupt fires.
741 *
742 * So the only way to run into this issue is if the delivery
743 * of the interrupt on the apic/system bus would be delayed
744 * beyond the point where the target cpu disables interrupts
745 * in stop machine. I doubt that it can happen, but at least
746 * there is a theroretical chance. Virtualization might be
747 * able to expose this, but AFAICT the IOAPIC emulation is not
748 * as stupid as the real hardware.
749 *
750 * Anyway, there is nothing we can do about that at this point
751 * w/o refactoring the whole fixup_irq() business completely.
752 * We print at least the irq number and the old vector number,
753 * so we have the necessary information when a problem in that
754 * area arises.
755 */
756 pr_warn("IRQ fixup: irq %d move in progress, old vector %d\n",
757 irqdata->irq, cfg->old_vector);
758 }
759 /*
760 * If old_domain is not empty, then other cpus still have the irq
761 * descriptor set in their vector array. Clean it up.
762 */
763 for_each_cpu(cpu, data->old_domain)
764 per_cpu(vector_irq, cpu)[cfg->old_vector] = VECTOR_UNUSED;
765
766 /* Cleanup the left overs of the (half finished) move */
767 cpumask_clear(data->old_domain);
768 data->move_in_progress = 0;
769 raw_spin_unlock(&vector_lock);
770 }
771 #endif
772
print_APIC_field(int base)773 static void __init print_APIC_field(int base)
774 {
775 int i;
776
777 printk(KERN_DEBUG);
778
779 for (i = 0; i < 8; i++)
780 pr_cont("%08x", apic_read(base + i*0x10));
781
782 pr_cont("\n");
783 }
784
print_local_APIC(void * dummy)785 static void __init print_local_APIC(void *dummy)
786 {
787 unsigned int i, v, ver, maxlvt;
788 u64 icr;
789
790 pr_debug("printing local APIC contents on CPU#%d/%d:\n",
791 smp_processor_id(), hard_smp_processor_id());
792 v = apic_read(APIC_ID);
793 pr_info("... APIC ID: %08x (%01x)\n", v, read_apic_id());
794 v = apic_read(APIC_LVR);
795 pr_info("... APIC VERSION: %08x\n", v);
796 ver = GET_APIC_VERSION(v);
797 maxlvt = lapic_get_maxlvt();
798
799 v = apic_read(APIC_TASKPRI);
800 pr_debug("... APIC TASKPRI: %08x (%02x)\n", v, v & APIC_TPRI_MASK);
801
802 /* !82489DX */
803 if (APIC_INTEGRATED(ver)) {
804 if (!APIC_XAPIC(ver)) {
805 v = apic_read(APIC_ARBPRI);
806 pr_debug("... APIC ARBPRI: %08x (%02x)\n",
807 v, v & APIC_ARBPRI_MASK);
808 }
809 v = apic_read(APIC_PROCPRI);
810 pr_debug("... APIC PROCPRI: %08x\n", v);
811 }
812
813 /*
814 * Remote read supported only in the 82489DX and local APIC for
815 * Pentium processors.
816 */
817 if (!APIC_INTEGRATED(ver) || maxlvt == 3) {
818 v = apic_read(APIC_RRR);
819 pr_debug("... APIC RRR: %08x\n", v);
820 }
821
822 v = apic_read(APIC_LDR);
823 pr_debug("... APIC LDR: %08x\n", v);
824 if (!x2apic_enabled()) {
825 v = apic_read(APIC_DFR);
826 pr_debug("... APIC DFR: %08x\n", v);
827 }
828 v = apic_read(APIC_SPIV);
829 pr_debug("... APIC SPIV: %08x\n", v);
830
831 pr_debug("... APIC ISR field:\n");
832 print_APIC_field(APIC_ISR);
833 pr_debug("... APIC TMR field:\n");
834 print_APIC_field(APIC_TMR);
835 pr_debug("... APIC IRR field:\n");
836 print_APIC_field(APIC_IRR);
837
838 /* !82489DX */
839 if (APIC_INTEGRATED(ver)) {
840 /* Due to the Pentium erratum 3AP. */
841 if (maxlvt > 3)
842 apic_write(APIC_ESR, 0);
843
844 v = apic_read(APIC_ESR);
845 pr_debug("... APIC ESR: %08x\n", v);
846 }
847
848 icr = apic_icr_read();
849 pr_debug("... APIC ICR: %08x\n", (u32)icr);
850 pr_debug("... APIC ICR2: %08x\n", (u32)(icr >> 32));
851
852 v = apic_read(APIC_LVTT);
853 pr_debug("... APIC LVTT: %08x\n", v);
854
855 if (maxlvt > 3) {
856 /* PC is LVT#4. */
857 v = apic_read(APIC_LVTPC);
858 pr_debug("... APIC LVTPC: %08x\n", v);
859 }
860 v = apic_read(APIC_LVT0);
861 pr_debug("... APIC LVT0: %08x\n", v);
862 v = apic_read(APIC_LVT1);
863 pr_debug("... APIC LVT1: %08x\n", v);
864
865 if (maxlvt > 2) {
866 /* ERR is LVT#3. */
867 v = apic_read(APIC_LVTERR);
868 pr_debug("... APIC LVTERR: %08x\n", v);
869 }
870
871 v = apic_read(APIC_TMICT);
872 pr_debug("... APIC TMICT: %08x\n", v);
873 v = apic_read(APIC_TMCCT);
874 pr_debug("... APIC TMCCT: %08x\n", v);
875 v = apic_read(APIC_TDCR);
876 pr_debug("... APIC TDCR: %08x\n", v);
877
878 if (boot_cpu_has(X86_FEATURE_EXTAPIC)) {
879 v = apic_read(APIC_EFEAT);
880 maxlvt = (v >> 16) & 0xff;
881 pr_debug("... APIC EFEAT: %08x\n", v);
882 v = apic_read(APIC_ECTRL);
883 pr_debug("... APIC ECTRL: %08x\n", v);
884 for (i = 0; i < maxlvt; i++) {
885 v = apic_read(APIC_EILVTn(i));
886 pr_debug("... APIC EILVT%d: %08x\n", i, v);
887 }
888 }
889 pr_cont("\n");
890 }
891
print_local_APICs(int maxcpu)892 static void __init print_local_APICs(int maxcpu)
893 {
894 int cpu;
895
896 if (!maxcpu)
897 return;
898
899 preempt_disable();
900 for_each_online_cpu(cpu) {
901 if (cpu >= maxcpu)
902 break;
903 smp_call_function_single(cpu, print_local_APIC, NULL, 1);
904 }
905 preempt_enable();
906 }
907
print_PIC(void)908 static void __init print_PIC(void)
909 {
910 unsigned int v;
911 unsigned long flags;
912
913 if (!nr_legacy_irqs())
914 return;
915
916 pr_debug("\nprinting PIC contents\n");
917
918 raw_spin_lock_irqsave(&i8259A_lock, flags);
919
920 v = inb(0xa1) << 8 | inb(0x21);
921 pr_debug("... PIC IMR: %04x\n", v);
922
923 v = inb(0xa0) << 8 | inb(0x20);
924 pr_debug("... PIC IRR: %04x\n", v);
925
926 outb(0x0b, 0xa0);
927 outb(0x0b, 0x20);
928 v = inb(0xa0) << 8 | inb(0x20);
929 outb(0x0a, 0xa0);
930 outb(0x0a, 0x20);
931
932 raw_spin_unlock_irqrestore(&i8259A_lock, flags);
933
934 pr_debug("... PIC ISR: %04x\n", v);
935
936 v = inb(0x4d1) << 8 | inb(0x4d0);
937 pr_debug("... PIC ELCR: %04x\n", v);
938 }
939
940 static int show_lapic __initdata = 1;
setup_show_lapic(char * arg)941 static __init int setup_show_lapic(char *arg)
942 {
943 int num = -1;
944
945 if (strcmp(arg, "all") == 0) {
946 show_lapic = CONFIG_NR_CPUS;
947 } else {
948 get_option(&arg, &num);
949 if (num >= 0)
950 show_lapic = num;
951 }
952
953 return 1;
954 }
955 __setup("show_lapic=", setup_show_lapic);
956
print_ICs(void)957 static int __init print_ICs(void)
958 {
959 if (apic_verbosity == APIC_QUIET)
960 return 0;
961
962 print_PIC();
963
964 /* don't print out if apic is not there */
965 if (!cpu_has_apic && !apic_from_smp_config())
966 return 0;
967
968 print_local_APICs(show_lapic);
969 print_IO_APICs();
970
971 return 0;
972 }
973
974 late_initcall(print_ICs);
975