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