xref: /linux/drivers/xen/events/events_base.c (revision fcc8487d477a3452a1d0ccbdd4c5e0e1e3cb8bed)
1 /*
2  * Xen event channels
3  *
4  * Xen models interrupts with abstract event channels.  Because each
5  * domain gets 1024 event channels, but NR_IRQ is not that large, we
6  * must dynamically map irqs<->event channels.  The event channels
7  * interface with the rest of the kernel by defining a xen interrupt
8  * chip.  When an event is received, it is mapped to an irq and sent
9  * through the normal interrupt processing path.
10  *
11  * There are four kinds of events which can be mapped to an event
12  * channel:
13  *
14  * 1. Inter-domain notifications.  This includes all the virtual
15  *    device events, since they're driven by front-ends in another domain
16  *    (typically dom0).
17  * 2. VIRQs, typically used for timers.  These are per-cpu events.
18  * 3. IPIs.
19  * 4. PIRQs - Hardware interrupts.
20  *
21  * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
22  */
23 
24 #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
25 
26 #include <linux/linkage.h>
27 #include <linux/interrupt.h>
28 #include <linux/irq.h>
29 #include <linux/moduleparam.h>
30 #include <linux/string.h>
31 #include <linux/bootmem.h>
32 #include <linux/slab.h>
33 #include <linux/irqnr.h>
34 #include <linux/pci.h>
35 
36 #ifdef CONFIG_X86
37 #include <asm/desc.h>
38 #include <asm/ptrace.h>
39 #include <asm/irq.h>
40 #include <asm/io_apic.h>
41 #include <asm/i8259.h>
42 #include <asm/xen/pci.h>
43 #endif
44 #include <asm/sync_bitops.h>
45 #include <asm/xen/hypercall.h>
46 #include <asm/xen/hypervisor.h>
47 #include <xen/page.h>
48 
49 #include <xen/xen.h>
50 #include <xen/hvm.h>
51 #include <xen/xen-ops.h>
52 #include <xen/events.h>
53 #include <xen/interface/xen.h>
54 #include <xen/interface/event_channel.h>
55 #include <xen/interface/hvm/hvm_op.h>
56 #include <xen/interface/hvm/params.h>
57 #include <xen/interface/physdev.h>
58 #include <xen/interface/sched.h>
59 #include <xen/interface/vcpu.h>
60 #include <asm/hw_irq.h>
61 
62 #include "events_internal.h"
63 
64 const struct evtchn_ops *evtchn_ops;
65 
66 /*
67  * This lock protects updates to the following mapping and reference-count
68  * arrays. The lock does not need to be acquired to read the mapping tables.
69  */
70 static DEFINE_MUTEX(irq_mapping_update_lock);
71 
72 static LIST_HEAD(xen_irq_list_head);
73 
74 /* IRQ <-> VIRQ mapping. */
75 static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
76 
77 /* IRQ <-> IPI mapping */
78 static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
79 
80 int **evtchn_to_irq;
81 #ifdef CONFIG_X86
82 static unsigned long *pirq_eoi_map;
83 #endif
84 static bool (*pirq_needs_eoi)(unsigned irq);
85 
86 #define EVTCHN_ROW(e)  (e / (PAGE_SIZE/sizeof(**evtchn_to_irq)))
87 #define EVTCHN_COL(e)  (e % (PAGE_SIZE/sizeof(**evtchn_to_irq)))
88 #define EVTCHN_PER_ROW (PAGE_SIZE / sizeof(**evtchn_to_irq))
89 
90 /* Xen will never allocate port zero for any purpose. */
91 #define VALID_EVTCHN(chn)	((chn) != 0)
92 
93 static struct irq_chip xen_dynamic_chip;
94 static struct irq_chip xen_percpu_chip;
95 static struct irq_chip xen_pirq_chip;
96 static void enable_dynirq(struct irq_data *data);
97 static void disable_dynirq(struct irq_data *data);
98 
99 static void clear_evtchn_to_irq_row(unsigned row)
100 {
101 	unsigned col;
102 
103 	for (col = 0; col < EVTCHN_PER_ROW; col++)
104 		evtchn_to_irq[row][col] = -1;
105 }
106 
107 static void clear_evtchn_to_irq_all(void)
108 {
109 	unsigned row;
110 
111 	for (row = 0; row < EVTCHN_ROW(xen_evtchn_max_channels()); row++) {
112 		if (evtchn_to_irq[row] == NULL)
113 			continue;
114 		clear_evtchn_to_irq_row(row);
115 	}
116 }
117 
118 static int set_evtchn_to_irq(unsigned evtchn, unsigned irq)
119 {
120 	unsigned row;
121 	unsigned col;
122 
123 	if (evtchn >= xen_evtchn_max_channels())
124 		return -EINVAL;
125 
126 	row = EVTCHN_ROW(evtchn);
127 	col = EVTCHN_COL(evtchn);
128 
129 	if (evtchn_to_irq[row] == NULL) {
130 		/* Unallocated irq entries return -1 anyway */
131 		if (irq == -1)
132 			return 0;
133 
134 		evtchn_to_irq[row] = (int *)get_zeroed_page(GFP_KERNEL);
135 		if (evtchn_to_irq[row] == NULL)
136 			return -ENOMEM;
137 
138 		clear_evtchn_to_irq_row(row);
139 	}
140 
141 	evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)] = irq;
142 	return 0;
143 }
144 
145 int get_evtchn_to_irq(unsigned evtchn)
146 {
147 	if (evtchn >= xen_evtchn_max_channels())
148 		return -1;
149 	if (evtchn_to_irq[EVTCHN_ROW(evtchn)] == NULL)
150 		return -1;
151 	return evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)];
152 }
153 
154 /* Get info for IRQ */
155 struct irq_info *info_for_irq(unsigned irq)
156 {
157 	return irq_get_handler_data(irq);
158 }
159 
160 /* Constructors for packed IRQ information. */
161 static int xen_irq_info_common_setup(struct irq_info *info,
162 				     unsigned irq,
163 				     enum xen_irq_type type,
164 				     unsigned evtchn,
165 				     unsigned short cpu)
166 {
167 	int ret;
168 
169 	BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
170 
171 	info->type = type;
172 	info->irq = irq;
173 	info->evtchn = evtchn;
174 	info->cpu = cpu;
175 
176 	ret = set_evtchn_to_irq(evtchn, irq);
177 	if (ret < 0)
178 		return ret;
179 
180 	irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN);
181 
182 	return xen_evtchn_port_setup(info);
183 }
184 
185 static int xen_irq_info_evtchn_setup(unsigned irq,
186 				     unsigned evtchn)
187 {
188 	struct irq_info *info = info_for_irq(irq);
189 
190 	return xen_irq_info_common_setup(info, irq, IRQT_EVTCHN, evtchn, 0);
191 }
192 
193 static int xen_irq_info_ipi_setup(unsigned cpu,
194 				  unsigned irq,
195 				  unsigned evtchn,
196 				  enum ipi_vector ipi)
197 {
198 	struct irq_info *info = info_for_irq(irq);
199 
200 	info->u.ipi = ipi;
201 
202 	per_cpu(ipi_to_irq, cpu)[ipi] = irq;
203 
204 	return xen_irq_info_common_setup(info, irq, IRQT_IPI, evtchn, 0);
205 }
206 
207 static int xen_irq_info_virq_setup(unsigned cpu,
208 				   unsigned irq,
209 				   unsigned evtchn,
210 				   unsigned virq)
211 {
212 	struct irq_info *info = info_for_irq(irq);
213 
214 	info->u.virq = virq;
215 
216 	per_cpu(virq_to_irq, cpu)[virq] = irq;
217 
218 	return xen_irq_info_common_setup(info, irq, IRQT_VIRQ, evtchn, 0);
219 }
220 
221 static int xen_irq_info_pirq_setup(unsigned irq,
222 				   unsigned evtchn,
223 				   unsigned pirq,
224 				   unsigned gsi,
225 				   uint16_t domid,
226 				   unsigned char flags)
227 {
228 	struct irq_info *info = info_for_irq(irq);
229 
230 	info->u.pirq.pirq = pirq;
231 	info->u.pirq.gsi = gsi;
232 	info->u.pirq.domid = domid;
233 	info->u.pirq.flags = flags;
234 
235 	return xen_irq_info_common_setup(info, irq, IRQT_PIRQ, evtchn, 0);
236 }
237 
238 static void xen_irq_info_cleanup(struct irq_info *info)
239 {
240 	set_evtchn_to_irq(info->evtchn, -1);
241 	info->evtchn = 0;
242 }
243 
244 /*
245  * Accessors for packed IRQ information.
246  */
247 unsigned int evtchn_from_irq(unsigned irq)
248 {
249 	if (unlikely(WARN(irq >= nr_irqs, "Invalid irq %d!\n", irq)))
250 		return 0;
251 
252 	return info_for_irq(irq)->evtchn;
253 }
254 
255 unsigned irq_from_evtchn(unsigned int evtchn)
256 {
257 	return get_evtchn_to_irq(evtchn);
258 }
259 EXPORT_SYMBOL_GPL(irq_from_evtchn);
260 
261 int irq_from_virq(unsigned int cpu, unsigned int virq)
262 {
263 	return per_cpu(virq_to_irq, cpu)[virq];
264 }
265 
266 static enum ipi_vector ipi_from_irq(unsigned irq)
267 {
268 	struct irq_info *info = info_for_irq(irq);
269 
270 	BUG_ON(info == NULL);
271 	BUG_ON(info->type != IRQT_IPI);
272 
273 	return info->u.ipi;
274 }
275 
276 static unsigned virq_from_irq(unsigned irq)
277 {
278 	struct irq_info *info = info_for_irq(irq);
279 
280 	BUG_ON(info == NULL);
281 	BUG_ON(info->type != IRQT_VIRQ);
282 
283 	return info->u.virq;
284 }
285 
286 static unsigned pirq_from_irq(unsigned irq)
287 {
288 	struct irq_info *info = info_for_irq(irq);
289 
290 	BUG_ON(info == NULL);
291 	BUG_ON(info->type != IRQT_PIRQ);
292 
293 	return info->u.pirq.pirq;
294 }
295 
296 static enum xen_irq_type type_from_irq(unsigned irq)
297 {
298 	return info_for_irq(irq)->type;
299 }
300 
301 unsigned cpu_from_irq(unsigned irq)
302 {
303 	return info_for_irq(irq)->cpu;
304 }
305 
306 unsigned int cpu_from_evtchn(unsigned int evtchn)
307 {
308 	int irq = get_evtchn_to_irq(evtchn);
309 	unsigned ret = 0;
310 
311 	if (irq != -1)
312 		ret = cpu_from_irq(irq);
313 
314 	return ret;
315 }
316 
317 #ifdef CONFIG_X86
318 static bool pirq_check_eoi_map(unsigned irq)
319 {
320 	return test_bit(pirq_from_irq(irq), pirq_eoi_map);
321 }
322 #endif
323 
324 static bool pirq_needs_eoi_flag(unsigned irq)
325 {
326 	struct irq_info *info = info_for_irq(irq);
327 	BUG_ON(info->type != IRQT_PIRQ);
328 
329 	return info->u.pirq.flags & PIRQ_NEEDS_EOI;
330 }
331 
332 static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
333 {
334 	int irq = get_evtchn_to_irq(chn);
335 	struct irq_info *info = info_for_irq(irq);
336 
337 	BUG_ON(irq == -1);
338 #ifdef CONFIG_SMP
339 	cpumask_copy(irq_get_affinity_mask(irq), cpumask_of(cpu));
340 #endif
341 	xen_evtchn_port_bind_to_cpu(info, cpu);
342 
343 	info->cpu = cpu;
344 }
345 
346 static void xen_evtchn_mask_all(void)
347 {
348 	unsigned int evtchn;
349 
350 	for (evtchn = 0; evtchn < xen_evtchn_nr_channels(); evtchn++)
351 		mask_evtchn(evtchn);
352 }
353 
354 /**
355  * notify_remote_via_irq - send event to remote end of event channel via irq
356  * @irq: irq of event channel to send event to
357  *
358  * Unlike notify_remote_via_evtchn(), this is safe to use across
359  * save/restore. Notifications on a broken connection are silently
360  * dropped.
361  */
362 void notify_remote_via_irq(int irq)
363 {
364 	int evtchn = evtchn_from_irq(irq);
365 
366 	if (VALID_EVTCHN(evtchn))
367 		notify_remote_via_evtchn(evtchn);
368 }
369 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
370 
371 static void xen_irq_init(unsigned irq)
372 {
373 	struct irq_info *info;
374 #ifdef CONFIG_SMP
375 	/* By default all event channels notify CPU#0. */
376 	cpumask_copy(irq_get_affinity_mask(irq), cpumask_of(0));
377 #endif
378 
379 	info = kzalloc(sizeof(*info), GFP_KERNEL);
380 	if (info == NULL)
381 		panic("Unable to allocate metadata for IRQ%d\n", irq);
382 
383 	info->type = IRQT_UNBOUND;
384 	info->refcnt = -1;
385 
386 	irq_set_handler_data(irq, info);
387 
388 	list_add_tail(&info->list, &xen_irq_list_head);
389 }
390 
391 static int __must_check xen_allocate_irqs_dynamic(int nvec)
392 {
393 	int i, irq = irq_alloc_descs(-1, 0, nvec, -1);
394 
395 	if (irq >= 0) {
396 		for (i = 0; i < nvec; i++)
397 			xen_irq_init(irq + i);
398 	}
399 
400 	return irq;
401 }
402 
403 static inline int __must_check xen_allocate_irq_dynamic(void)
404 {
405 
406 	return xen_allocate_irqs_dynamic(1);
407 }
408 
409 static int __must_check xen_allocate_irq_gsi(unsigned gsi)
410 {
411 	int irq;
412 
413 	/*
414 	 * A PV guest has no concept of a GSI (since it has no ACPI
415 	 * nor access to/knowledge of the physical APICs). Therefore
416 	 * all IRQs are dynamically allocated from the entire IRQ
417 	 * space.
418 	 */
419 	if (xen_pv_domain() && !xen_initial_domain())
420 		return xen_allocate_irq_dynamic();
421 
422 	/* Legacy IRQ descriptors are already allocated by the arch. */
423 	if (gsi < nr_legacy_irqs())
424 		irq = gsi;
425 	else
426 		irq = irq_alloc_desc_at(gsi, -1);
427 
428 	xen_irq_init(irq);
429 
430 	return irq;
431 }
432 
433 static void xen_free_irq(unsigned irq)
434 {
435 	struct irq_info *info = irq_get_handler_data(irq);
436 
437 	if (WARN_ON(!info))
438 		return;
439 
440 	list_del(&info->list);
441 
442 	irq_set_handler_data(irq, NULL);
443 
444 	WARN_ON(info->refcnt > 0);
445 
446 	kfree(info);
447 
448 	/* Legacy IRQ descriptors are managed by the arch. */
449 	if (irq < nr_legacy_irqs())
450 		return;
451 
452 	irq_free_desc(irq);
453 }
454 
455 static void xen_evtchn_close(unsigned int port)
456 {
457 	struct evtchn_close close;
458 
459 	close.port = port;
460 	if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
461 		BUG();
462 }
463 
464 static void pirq_query_unmask(int irq)
465 {
466 	struct physdev_irq_status_query irq_status;
467 	struct irq_info *info = info_for_irq(irq);
468 
469 	BUG_ON(info->type != IRQT_PIRQ);
470 
471 	irq_status.irq = pirq_from_irq(irq);
472 	if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
473 		irq_status.flags = 0;
474 
475 	info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
476 	if (irq_status.flags & XENIRQSTAT_needs_eoi)
477 		info->u.pirq.flags |= PIRQ_NEEDS_EOI;
478 }
479 
480 static void eoi_pirq(struct irq_data *data)
481 {
482 	int evtchn = evtchn_from_irq(data->irq);
483 	struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
484 	int rc = 0;
485 
486 	if (!VALID_EVTCHN(evtchn))
487 		return;
488 
489 	if (unlikely(irqd_is_setaffinity_pending(data)) &&
490 	    likely(!irqd_irq_disabled(data))) {
491 		int masked = test_and_set_mask(evtchn);
492 
493 		clear_evtchn(evtchn);
494 
495 		irq_move_masked_irq(data);
496 
497 		if (!masked)
498 			unmask_evtchn(evtchn);
499 	} else
500 		clear_evtchn(evtchn);
501 
502 	if (pirq_needs_eoi(data->irq)) {
503 		rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
504 		WARN_ON(rc);
505 	}
506 }
507 
508 static void mask_ack_pirq(struct irq_data *data)
509 {
510 	disable_dynirq(data);
511 	eoi_pirq(data);
512 }
513 
514 static unsigned int __startup_pirq(unsigned int irq)
515 {
516 	struct evtchn_bind_pirq bind_pirq;
517 	struct irq_info *info = info_for_irq(irq);
518 	int evtchn = evtchn_from_irq(irq);
519 	int rc;
520 
521 	BUG_ON(info->type != IRQT_PIRQ);
522 
523 	if (VALID_EVTCHN(evtchn))
524 		goto out;
525 
526 	bind_pirq.pirq = pirq_from_irq(irq);
527 	/* NB. We are happy to share unless we are probing. */
528 	bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
529 					BIND_PIRQ__WILL_SHARE : 0;
530 	rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
531 	if (rc != 0) {
532 		pr_warn("Failed to obtain physical IRQ %d\n", irq);
533 		return 0;
534 	}
535 	evtchn = bind_pirq.port;
536 
537 	pirq_query_unmask(irq);
538 
539 	rc = set_evtchn_to_irq(evtchn, irq);
540 	if (rc)
541 		goto err;
542 
543 	info->evtchn = evtchn;
544 	bind_evtchn_to_cpu(evtchn, 0);
545 
546 	rc = xen_evtchn_port_setup(info);
547 	if (rc)
548 		goto err;
549 
550 out:
551 	unmask_evtchn(evtchn);
552 	eoi_pirq(irq_get_irq_data(irq));
553 
554 	return 0;
555 
556 err:
557 	pr_err("irq%d: Failed to set port to irq mapping (%d)\n", irq, rc);
558 	xen_evtchn_close(evtchn);
559 	return 0;
560 }
561 
562 static unsigned int startup_pirq(struct irq_data *data)
563 {
564 	return __startup_pirq(data->irq);
565 }
566 
567 static void shutdown_pirq(struct irq_data *data)
568 {
569 	unsigned int irq = data->irq;
570 	struct irq_info *info = info_for_irq(irq);
571 	unsigned evtchn = evtchn_from_irq(irq);
572 
573 	BUG_ON(info->type != IRQT_PIRQ);
574 
575 	if (!VALID_EVTCHN(evtchn))
576 		return;
577 
578 	mask_evtchn(evtchn);
579 	xen_evtchn_close(evtchn);
580 	xen_irq_info_cleanup(info);
581 }
582 
583 static void enable_pirq(struct irq_data *data)
584 {
585 	startup_pirq(data);
586 }
587 
588 static void disable_pirq(struct irq_data *data)
589 {
590 	disable_dynirq(data);
591 }
592 
593 int xen_irq_from_gsi(unsigned gsi)
594 {
595 	struct irq_info *info;
596 
597 	list_for_each_entry(info, &xen_irq_list_head, list) {
598 		if (info->type != IRQT_PIRQ)
599 			continue;
600 
601 		if (info->u.pirq.gsi == gsi)
602 			return info->irq;
603 	}
604 
605 	return -1;
606 }
607 EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
608 
609 static void __unbind_from_irq(unsigned int irq)
610 {
611 	int evtchn = evtchn_from_irq(irq);
612 	struct irq_info *info = irq_get_handler_data(irq);
613 
614 	if (info->refcnt > 0) {
615 		info->refcnt--;
616 		if (info->refcnt != 0)
617 			return;
618 	}
619 
620 	if (VALID_EVTCHN(evtchn)) {
621 		unsigned int cpu = cpu_from_irq(irq);
622 
623 		xen_evtchn_close(evtchn);
624 
625 		switch (type_from_irq(irq)) {
626 		case IRQT_VIRQ:
627 			per_cpu(virq_to_irq, cpu)[virq_from_irq(irq)] = -1;
628 			break;
629 		case IRQT_IPI:
630 			per_cpu(ipi_to_irq, cpu)[ipi_from_irq(irq)] = -1;
631 			break;
632 		default:
633 			break;
634 		}
635 
636 		xen_irq_info_cleanup(info);
637 	}
638 
639 	BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
640 
641 	xen_free_irq(irq);
642 }
643 
644 /*
645  * Do not make any assumptions regarding the relationship between the
646  * IRQ number returned here and the Xen pirq argument.
647  *
648  * Note: We don't assign an event channel until the irq actually started
649  * up.  Return an existing irq if we've already got one for the gsi.
650  *
651  * Shareable implies level triggered, not shareable implies edge
652  * triggered here.
653  */
654 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
655 			     unsigned pirq, int shareable, char *name)
656 {
657 	int irq = -1;
658 	struct physdev_irq irq_op;
659 	int ret;
660 
661 	mutex_lock(&irq_mapping_update_lock);
662 
663 	irq = xen_irq_from_gsi(gsi);
664 	if (irq != -1) {
665 		pr_info("%s: returning irq %d for gsi %u\n",
666 			__func__, irq, gsi);
667 		goto out;
668 	}
669 
670 	irq = xen_allocate_irq_gsi(gsi);
671 	if (irq < 0)
672 		goto out;
673 
674 	irq_op.irq = irq;
675 	irq_op.vector = 0;
676 
677 	/* Only the privileged domain can do this. For non-priv, the pcifront
678 	 * driver provides a PCI bus that does the call to do exactly
679 	 * this in the priv domain. */
680 	if (xen_initial_domain() &&
681 	    HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
682 		xen_free_irq(irq);
683 		irq = -ENOSPC;
684 		goto out;
685 	}
686 
687 	ret = xen_irq_info_pirq_setup(irq, 0, pirq, gsi, DOMID_SELF,
688 			       shareable ? PIRQ_SHAREABLE : 0);
689 	if (ret < 0) {
690 		__unbind_from_irq(irq);
691 		irq = ret;
692 		goto out;
693 	}
694 
695 	pirq_query_unmask(irq);
696 	/* We try to use the handler with the appropriate semantic for the
697 	 * type of interrupt: if the interrupt is an edge triggered
698 	 * interrupt we use handle_edge_irq.
699 	 *
700 	 * On the other hand if the interrupt is level triggered we use
701 	 * handle_fasteoi_irq like the native code does for this kind of
702 	 * interrupts.
703 	 *
704 	 * Depending on the Xen version, pirq_needs_eoi might return true
705 	 * not only for level triggered interrupts but for edge triggered
706 	 * interrupts too. In any case Xen always honors the eoi mechanism,
707 	 * not injecting any more pirqs of the same kind if the first one
708 	 * hasn't received an eoi yet. Therefore using the fasteoi handler
709 	 * is the right choice either way.
710 	 */
711 	if (shareable)
712 		irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
713 				handle_fasteoi_irq, name);
714 	else
715 		irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
716 				handle_edge_irq, name);
717 
718 out:
719 	mutex_unlock(&irq_mapping_update_lock);
720 
721 	return irq;
722 }
723 
724 #ifdef CONFIG_PCI_MSI
725 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
726 {
727 	int rc;
728 	struct physdev_get_free_pirq op_get_free_pirq;
729 
730 	op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
731 	rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
732 
733 	WARN_ONCE(rc == -ENOSYS,
734 		  "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
735 
736 	return rc ? -1 : op_get_free_pirq.pirq;
737 }
738 
739 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
740 			     int pirq, int nvec, const char *name, domid_t domid)
741 {
742 	int i, irq, ret;
743 
744 	mutex_lock(&irq_mapping_update_lock);
745 
746 	irq = xen_allocate_irqs_dynamic(nvec);
747 	if (irq < 0)
748 		goto out;
749 
750 	for (i = 0; i < nvec; i++) {
751 		irq_set_chip_and_handler_name(irq + i, &xen_pirq_chip, handle_edge_irq, name);
752 
753 		ret = xen_irq_info_pirq_setup(irq + i, 0, pirq + i, 0, domid,
754 					      i == 0 ? 0 : PIRQ_MSI_GROUP);
755 		if (ret < 0)
756 			goto error_irq;
757 	}
758 
759 	ret = irq_set_msi_desc(irq, msidesc);
760 	if (ret < 0)
761 		goto error_irq;
762 out:
763 	mutex_unlock(&irq_mapping_update_lock);
764 	return irq;
765 error_irq:
766 	for (; i >= 0; i--)
767 		__unbind_from_irq(irq + i);
768 	mutex_unlock(&irq_mapping_update_lock);
769 	return ret;
770 }
771 #endif
772 
773 int xen_destroy_irq(int irq)
774 {
775 	struct physdev_unmap_pirq unmap_irq;
776 	struct irq_info *info = info_for_irq(irq);
777 	int rc = -ENOENT;
778 
779 	mutex_lock(&irq_mapping_update_lock);
780 
781 	/*
782 	 * If trying to remove a vector in a MSI group different
783 	 * than the first one skip the PIRQ unmap unless this vector
784 	 * is the first one in the group.
785 	 */
786 	if (xen_initial_domain() && !(info->u.pirq.flags & PIRQ_MSI_GROUP)) {
787 		unmap_irq.pirq = info->u.pirq.pirq;
788 		unmap_irq.domid = info->u.pirq.domid;
789 		rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
790 		/* If another domain quits without making the pci_disable_msix
791 		 * call, the Xen hypervisor takes care of freeing the PIRQs
792 		 * (free_domain_pirqs).
793 		 */
794 		if ((rc == -ESRCH && info->u.pirq.domid != DOMID_SELF))
795 			pr_info("domain %d does not have %d anymore\n",
796 				info->u.pirq.domid, info->u.pirq.pirq);
797 		else if (rc) {
798 			pr_warn("unmap irq failed %d\n", rc);
799 			goto out;
800 		}
801 	}
802 
803 	xen_free_irq(irq);
804 
805 out:
806 	mutex_unlock(&irq_mapping_update_lock);
807 	return rc;
808 }
809 
810 int xen_irq_from_pirq(unsigned pirq)
811 {
812 	int irq;
813 
814 	struct irq_info *info;
815 
816 	mutex_lock(&irq_mapping_update_lock);
817 
818 	list_for_each_entry(info, &xen_irq_list_head, list) {
819 		if (info->type != IRQT_PIRQ)
820 			continue;
821 		irq = info->irq;
822 		if (info->u.pirq.pirq == pirq)
823 			goto out;
824 	}
825 	irq = -1;
826 out:
827 	mutex_unlock(&irq_mapping_update_lock);
828 
829 	return irq;
830 }
831 
832 
833 int xen_pirq_from_irq(unsigned irq)
834 {
835 	return pirq_from_irq(irq);
836 }
837 EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
838 
839 int bind_evtchn_to_irq(unsigned int evtchn)
840 {
841 	int irq;
842 	int ret;
843 
844 	if (evtchn >= xen_evtchn_max_channels())
845 		return -ENOMEM;
846 
847 	mutex_lock(&irq_mapping_update_lock);
848 
849 	irq = get_evtchn_to_irq(evtchn);
850 
851 	if (irq == -1) {
852 		irq = xen_allocate_irq_dynamic();
853 		if (irq < 0)
854 			goto out;
855 
856 		irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
857 					      handle_edge_irq, "event");
858 
859 		ret = xen_irq_info_evtchn_setup(irq, evtchn);
860 		if (ret < 0) {
861 			__unbind_from_irq(irq);
862 			irq = ret;
863 			goto out;
864 		}
865 		/* New interdomain events are bound to VCPU 0. */
866 		bind_evtchn_to_cpu(evtchn, 0);
867 	} else {
868 		struct irq_info *info = info_for_irq(irq);
869 		WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
870 	}
871 
872 out:
873 	mutex_unlock(&irq_mapping_update_lock);
874 
875 	return irq;
876 }
877 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
878 
879 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
880 {
881 	struct evtchn_bind_ipi bind_ipi;
882 	int evtchn, irq;
883 	int ret;
884 
885 	mutex_lock(&irq_mapping_update_lock);
886 
887 	irq = per_cpu(ipi_to_irq, cpu)[ipi];
888 
889 	if (irq == -1) {
890 		irq = xen_allocate_irq_dynamic();
891 		if (irq < 0)
892 			goto out;
893 
894 		irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
895 					      handle_percpu_irq, "ipi");
896 
897 		bind_ipi.vcpu = xen_vcpu_nr(cpu);
898 		if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
899 						&bind_ipi) != 0)
900 			BUG();
901 		evtchn = bind_ipi.port;
902 
903 		ret = xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
904 		if (ret < 0) {
905 			__unbind_from_irq(irq);
906 			irq = ret;
907 			goto out;
908 		}
909 		bind_evtchn_to_cpu(evtchn, cpu);
910 	} else {
911 		struct irq_info *info = info_for_irq(irq);
912 		WARN_ON(info == NULL || info->type != IRQT_IPI);
913 	}
914 
915  out:
916 	mutex_unlock(&irq_mapping_update_lock);
917 	return irq;
918 }
919 
920 int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
921 				   unsigned int remote_port)
922 {
923 	struct evtchn_bind_interdomain bind_interdomain;
924 	int err;
925 
926 	bind_interdomain.remote_dom  = remote_domain;
927 	bind_interdomain.remote_port = remote_port;
928 
929 	err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
930 					  &bind_interdomain);
931 
932 	return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
933 }
934 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq);
935 
936 static int find_virq(unsigned int virq, unsigned int cpu)
937 {
938 	struct evtchn_status status;
939 	int port, rc = -ENOENT;
940 
941 	memset(&status, 0, sizeof(status));
942 	for (port = 0; port < xen_evtchn_max_channels(); port++) {
943 		status.dom = DOMID_SELF;
944 		status.port = port;
945 		rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status);
946 		if (rc < 0)
947 			continue;
948 		if (status.status != EVTCHNSTAT_virq)
949 			continue;
950 		if (status.u.virq == virq && status.vcpu == xen_vcpu_nr(cpu)) {
951 			rc = port;
952 			break;
953 		}
954 	}
955 	return rc;
956 }
957 
958 /**
959  * xen_evtchn_nr_channels - number of usable event channel ports
960  *
961  * This may be less than the maximum supported by the current
962  * hypervisor ABI. Use xen_evtchn_max_channels() for the maximum
963  * supported.
964  */
965 unsigned xen_evtchn_nr_channels(void)
966 {
967         return evtchn_ops->nr_channels();
968 }
969 EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
970 
971 int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
972 {
973 	struct evtchn_bind_virq bind_virq;
974 	int evtchn, irq, ret;
975 
976 	mutex_lock(&irq_mapping_update_lock);
977 
978 	irq = per_cpu(virq_to_irq, cpu)[virq];
979 
980 	if (irq == -1) {
981 		irq = xen_allocate_irq_dynamic();
982 		if (irq < 0)
983 			goto out;
984 
985 		if (percpu)
986 			irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
987 						      handle_percpu_irq, "virq");
988 		else
989 			irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
990 						      handle_edge_irq, "virq");
991 
992 		bind_virq.virq = virq;
993 		bind_virq.vcpu = xen_vcpu_nr(cpu);
994 		ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
995 						&bind_virq);
996 		if (ret == 0)
997 			evtchn = bind_virq.port;
998 		else {
999 			if (ret == -EEXIST)
1000 				ret = find_virq(virq, cpu);
1001 			BUG_ON(ret < 0);
1002 			evtchn = ret;
1003 		}
1004 
1005 		ret = xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
1006 		if (ret < 0) {
1007 			__unbind_from_irq(irq);
1008 			irq = ret;
1009 			goto out;
1010 		}
1011 
1012 		bind_evtchn_to_cpu(evtchn, cpu);
1013 	} else {
1014 		struct irq_info *info = info_for_irq(irq);
1015 		WARN_ON(info == NULL || info->type != IRQT_VIRQ);
1016 	}
1017 
1018 out:
1019 	mutex_unlock(&irq_mapping_update_lock);
1020 
1021 	return irq;
1022 }
1023 
1024 static void unbind_from_irq(unsigned int irq)
1025 {
1026 	mutex_lock(&irq_mapping_update_lock);
1027 	__unbind_from_irq(irq);
1028 	mutex_unlock(&irq_mapping_update_lock);
1029 }
1030 
1031 int bind_evtchn_to_irqhandler(unsigned int evtchn,
1032 			      irq_handler_t handler,
1033 			      unsigned long irqflags,
1034 			      const char *devname, void *dev_id)
1035 {
1036 	int irq, retval;
1037 
1038 	irq = bind_evtchn_to_irq(evtchn);
1039 	if (irq < 0)
1040 		return irq;
1041 	retval = request_irq(irq, handler, irqflags, devname, dev_id);
1042 	if (retval != 0) {
1043 		unbind_from_irq(irq);
1044 		return retval;
1045 	}
1046 
1047 	return irq;
1048 }
1049 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
1050 
1051 int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
1052 					  unsigned int remote_port,
1053 					  irq_handler_t handler,
1054 					  unsigned long irqflags,
1055 					  const char *devname,
1056 					  void *dev_id)
1057 {
1058 	int irq, retval;
1059 
1060 	irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
1061 	if (irq < 0)
1062 		return irq;
1063 
1064 	retval = request_irq(irq, handler, irqflags, devname, dev_id);
1065 	if (retval != 0) {
1066 		unbind_from_irq(irq);
1067 		return retval;
1068 	}
1069 
1070 	return irq;
1071 }
1072 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
1073 
1074 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
1075 			    irq_handler_t handler,
1076 			    unsigned long irqflags, const char *devname, void *dev_id)
1077 {
1078 	int irq, retval;
1079 
1080 	irq = bind_virq_to_irq(virq, cpu, irqflags & IRQF_PERCPU);
1081 	if (irq < 0)
1082 		return irq;
1083 	retval = request_irq(irq, handler, irqflags, devname, dev_id);
1084 	if (retval != 0) {
1085 		unbind_from_irq(irq);
1086 		return retval;
1087 	}
1088 
1089 	return irq;
1090 }
1091 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
1092 
1093 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
1094 			   unsigned int cpu,
1095 			   irq_handler_t handler,
1096 			   unsigned long irqflags,
1097 			   const char *devname,
1098 			   void *dev_id)
1099 {
1100 	int irq, retval;
1101 
1102 	irq = bind_ipi_to_irq(ipi, cpu);
1103 	if (irq < 0)
1104 		return irq;
1105 
1106 	irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME | IRQF_EARLY_RESUME;
1107 	retval = request_irq(irq, handler, irqflags, devname, dev_id);
1108 	if (retval != 0) {
1109 		unbind_from_irq(irq);
1110 		return retval;
1111 	}
1112 
1113 	return irq;
1114 }
1115 
1116 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
1117 {
1118 	struct irq_info *info = irq_get_handler_data(irq);
1119 
1120 	if (WARN_ON(!info))
1121 		return;
1122 	free_irq(irq, dev_id);
1123 	unbind_from_irq(irq);
1124 }
1125 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
1126 
1127 /**
1128  * xen_set_irq_priority() - set an event channel priority.
1129  * @irq:irq bound to an event channel.
1130  * @priority: priority between XEN_IRQ_PRIORITY_MAX and XEN_IRQ_PRIORITY_MIN.
1131  */
1132 int xen_set_irq_priority(unsigned irq, unsigned priority)
1133 {
1134 	struct evtchn_set_priority set_priority;
1135 
1136 	set_priority.port = evtchn_from_irq(irq);
1137 	set_priority.priority = priority;
1138 
1139 	return HYPERVISOR_event_channel_op(EVTCHNOP_set_priority,
1140 					   &set_priority);
1141 }
1142 EXPORT_SYMBOL_GPL(xen_set_irq_priority);
1143 
1144 int evtchn_make_refcounted(unsigned int evtchn)
1145 {
1146 	int irq = get_evtchn_to_irq(evtchn);
1147 	struct irq_info *info;
1148 
1149 	if (irq == -1)
1150 		return -ENOENT;
1151 
1152 	info = irq_get_handler_data(irq);
1153 
1154 	if (!info)
1155 		return -ENOENT;
1156 
1157 	WARN_ON(info->refcnt != -1);
1158 
1159 	info->refcnt = 1;
1160 
1161 	return 0;
1162 }
1163 EXPORT_SYMBOL_GPL(evtchn_make_refcounted);
1164 
1165 int evtchn_get(unsigned int evtchn)
1166 {
1167 	int irq;
1168 	struct irq_info *info;
1169 	int err = -ENOENT;
1170 
1171 	if (evtchn >= xen_evtchn_max_channels())
1172 		return -EINVAL;
1173 
1174 	mutex_lock(&irq_mapping_update_lock);
1175 
1176 	irq = get_evtchn_to_irq(evtchn);
1177 	if (irq == -1)
1178 		goto done;
1179 
1180 	info = irq_get_handler_data(irq);
1181 
1182 	if (!info)
1183 		goto done;
1184 
1185 	err = -EINVAL;
1186 	if (info->refcnt <= 0)
1187 		goto done;
1188 
1189 	info->refcnt++;
1190 	err = 0;
1191  done:
1192 	mutex_unlock(&irq_mapping_update_lock);
1193 
1194 	return err;
1195 }
1196 EXPORT_SYMBOL_GPL(evtchn_get);
1197 
1198 void evtchn_put(unsigned int evtchn)
1199 {
1200 	int irq = get_evtchn_to_irq(evtchn);
1201 	if (WARN_ON(irq == -1))
1202 		return;
1203 	unbind_from_irq(irq);
1204 }
1205 EXPORT_SYMBOL_GPL(evtchn_put);
1206 
1207 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
1208 {
1209 	int irq;
1210 
1211 #ifdef CONFIG_X86
1212 	if (unlikely(vector == XEN_NMI_VECTOR)) {
1213 		int rc =  HYPERVISOR_vcpu_op(VCPUOP_send_nmi, xen_vcpu_nr(cpu),
1214 					     NULL);
1215 		if (rc < 0)
1216 			printk(KERN_WARNING "Sending nmi to CPU%d failed (rc:%d)\n", cpu, rc);
1217 		return;
1218 	}
1219 #endif
1220 	irq = per_cpu(ipi_to_irq, cpu)[vector];
1221 	BUG_ON(irq < 0);
1222 	notify_remote_via_irq(irq);
1223 }
1224 
1225 static DEFINE_PER_CPU(unsigned, xed_nesting_count);
1226 
1227 static void __xen_evtchn_do_upcall(void)
1228 {
1229 	struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1230 	int cpu = get_cpu();
1231 	unsigned count;
1232 
1233 	do {
1234 		vcpu_info->evtchn_upcall_pending = 0;
1235 
1236 		if (__this_cpu_inc_return(xed_nesting_count) - 1)
1237 			goto out;
1238 
1239 		xen_evtchn_handle_events(cpu);
1240 
1241 		BUG_ON(!irqs_disabled());
1242 
1243 		count = __this_cpu_read(xed_nesting_count);
1244 		__this_cpu_write(xed_nesting_count, 0);
1245 	} while (count != 1 || vcpu_info->evtchn_upcall_pending);
1246 
1247 out:
1248 
1249 	put_cpu();
1250 }
1251 
1252 void xen_evtchn_do_upcall(struct pt_regs *regs)
1253 {
1254 	struct pt_regs *old_regs = set_irq_regs(regs);
1255 
1256 	irq_enter();
1257 #ifdef CONFIG_X86
1258 	inc_irq_stat(irq_hv_callback_count);
1259 #endif
1260 
1261 	__xen_evtchn_do_upcall();
1262 
1263 	irq_exit();
1264 	set_irq_regs(old_regs);
1265 }
1266 
1267 void xen_hvm_evtchn_do_upcall(void)
1268 {
1269 	__xen_evtchn_do_upcall();
1270 }
1271 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1272 
1273 /* Rebind a new event channel to an existing irq. */
1274 void rebind_evtchn_irq(int evtchn, int irq)
1275 {
1276 	struct irq_info *info = info_for_irq(irq);
1277 
1278 	if (WARN_ON(!info))
1279 		return;
1280 
1281 	/* Make sure the irq is masked, since the new event channel
1282 	   will also be masked. */
1283 	disable_irq(irq);
1284 
1285 	mutex_lock(&irq_mapping_update_lock);
1286 
1287 	/* After resume the irq<->evtchn mappings are all cleared out */
1288 	BUG_ON(get_evtchn_to_irq(evtchn) != -1);
1289 	/* Expect irq to have been bound before,
1290 	   so there should be a proper type */
1291 	BUG_ON(info->type == IRQT_UNBOUND);
1292 
1293 	(void)xen_irq_info_evtchn_setup(irq, evtchn);
1294 
1295 	mutex_unlock(&irq_mapping_update_lock);
1296 
1297         bind_evtchn_to_cpu(evtchn, info->cpu);
1298 	/* This will be deferred until interrupt is processed */
1299 	irq_set_affinity(irq, cpumask_of(info->cpu));
1300 
1301 	/* Unmask the event channel. */
1302 	enable_irq(irq);
1303 }
1304 
1305 /* Rebind an evtchn so that it gets delivered to a specific cpu */
1306 static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
1307 {
1308 	struct evtchn_bind_vcpu bind_vcpu;
1309 	int evtchn = evtchn_from_irq(irq);
1310 	int masked;
1311 
1312 	if (!VALID_EVTCHN(evtchn))
1313 		return -1;
1314 
1315 	if (!xen_support_evtchn_rebind())
1316 		return -1;
1317 
1318 	/* Send future instances of this interrupt to other vcpu. */
1319 	bind_vcpu.port = evtchn;
1320 	bind_vcpu.vcpu = xen_vcpu_nr(tcpu);
1321 
1322 	/*
1323 	 * Mask the event while changing the VCPU binding to prevent
1324 	 * it being delivered on an unexpected VCPU.
1325 	 */
1326 	masked = test_and_set_mask(evtchn);
1327 
1328 	/*
1329 	 * If this fails, it usually just indicates that we're dealing with a
1330 	 * virq or IPI channel, which don't actually need to be rebound. Ignore
1331 	 * it, but don't do the xenlinux-level rebind in that case.
1332 	 */
1333 	if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1334 		bind_evtchn_to_cpu(evtchn, tcpu);
1335 
1336 	if (!masked)
1337 		unmask_evtchn(evtchn);
1338 
1339 	return 0;
1340 }
1341 
1342 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1343 			    bool force)
1344 {
1345 	unsigned tcpu = cpumask_first_and(dest, cpu_online_mask);
1346 
1347 	return rebind_irq_to_cpu(data->irq, tcpu);
1348 }
1349 
1350 static void enable_dynirq(struct irq_data *data)
1351 {
1352 	int evtchn = evtchn_from_irq(data->irq);
1353 
1354 	if (VALID_EVTCHN(evtchn))
1355 		unmask_evtchn(evtchn);
1356 }
1357 
1358 static void disable_dynirq(struct irq_data *data)
1359 {
1360 	int evtchn = evtchn_from_irq(data->irq);
1361 
1362 	if (VALID_EVTCHN(evtchn))
1363 		mask_evtchn(evtchn);
1364 }
1365 
1366 static void ack_dynirq(struct irq_data *data)
1367 {
1368 	int evtchn = evtchn_from_irq(data->irq);
1369 
1370 	if (!VALID_EVTCHN(evtchn))
1371 		return;
1372 
1373 	if (unlikely(irqd_is_setaffinity_pending(data)) &&
1374 	    likely(!irqd_irq_disabled(data))) {
1375 		int masked = test_and_set_mask(evtchn);
1376 
1377 		clear_evtchn(evtchn);
1378 
1379 		irq_move_masked_irq(data);
1380 
1381 		if (!masked)
1382 			unmask_evtchn(evtchn);
1383 	} else
1384 		clear_evtchn(evtchn);
1385 }
1386 
1387 static void mask_ack_dynirq(struct irq_data *data)
1388 {
1389 	disable_dynirq(data);
1390 	ack_dynirq(data);
1391 }
1392 
1393 static int retrigger_dynirq(struct irq_data *data)
1394 {
1395 	unsigned int evtchn = evtchn_from_irq(data->irq);
1396 	int masked;
1397 
1398 	if (!VALID_EVTCHN(evtchn))
1399 		return 0;
1400 
1401 	masked = test_and_set_mask(evtchn);
1402 	set_evtchn(evtchn);
1403 	if (!masked)
1404 		unmask_evtchn(evtchn);
1405 
1406 	return 1;
1407 }
1408 
1409 static void restore_pirqs(void)
1410 {
1411 	int pirq, rc, irq, gsi;
1412 	struct physdev_map_pirq map_irq;
1413 	struct irq_info *info;
1414 
1415 	list_for_each_entry(info, &xen_irq_list_head, list) {
1416 		if (info->type != IRQT_PIRQ)
1417 			continue;
1418 
1419 		pirq = info->u.pirq.pirq;
1420 		gsi = info->u.pirq.gsi;
1421 		irq = info->irq;
1422 
1423 		/* save/restore of PT devices doesn't work, so at this point the
1424 		 * only devices present are GSI based emulated devices */
1425 		if (!gsi)
1426 			continue;
1427 
1428 		map_irq.domid = DOMID_SELF;
1429 		map_irq.type = MAP_PIRQ_TYPE_GSI;
1430 		map_irq.index = gsi;
1431 		map_irq.pirq = pirq;
1432 
1433 		rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1434 		if (rc) {
1435 			pr_warn("xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1436 				gsi, irq, pirq, rc);
1437 			xen_free_irq(irq);
1438 			continue;
1439 		}
1440 
1441 		printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1442 
1443 		__startup_pirq(irq);
1444 	}
1445 }
1446 
1447 static void restore_cpu_virqs(unsigned int cpu)
1448 {
1449 	struct evtchn_bind_virq bind_virq;
1450 	int virq, irq, evtchn;
1451 
1452 	for (virq = 0; virq < NR_VIRQS; virq++) {
1453 		if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1454 			continue;
1455 
1456 		BUG_ON(virq_from_irq(irq) != virq);
1457 
1458 		/* Get a new binding from Xen. */
1459 		bind_virq.virq = virq;
1460 		bind_virq.vcpu = xen_vcpu_nr(cpu);
1461 		if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1462 						&bind_virq) != 0)
1463 			BUG();
1464 		evtchn = bind_virq.port;
1465 
1466 		/* Record the new mapping. */
1467 		(void)xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
1468 		bind_evtchn_to_cpu(evtchn, cpu);
1469 	}
1470 }
1471 
1472 static void restore_cpu_ipis(unsigned int cpu)
1473 {
1474 	struct evtchn_bind_ipi bind_ipi;
1475 	int ipi, irq, evtchn;
1476 
1477 	for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1478 		if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1479 			continue;
1480 
1481 		BUG_ON(ipi_from_irq(irq) != ipi);
1482 
1483 		/* Get a new binding from Xen. */
1484 		bind_ipi.vcpu = xen_vcpu_nr(cpu);
1485 		if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1486 						&bind_ipi) != 0)
1487 			BUG();
1488 		evtchn = bind_ipi.port;
1489 
1490 		/* Record the new mapping. */
1491 		(void)xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
1492 		bind_evtchn_to_cpu(evtchn, cpu);
1493 	}
1494 }
1495 
1496 /* Clear an irq's pending state, in preparation for polling on it */
1497 void xen_clear_irq_pending(int irq)
1498 {
1499 	int evtchn = evtchn_from_irq(irq);
1500 
1501 	if (VALID_EVTCHN(evtchn))
1502 		clear_evtchn(evtchn);
1503 }
1504 EXPORT_SYMBOL(xen_clear_irq_pending);
1505 void xen_set_irq_pending(int irq)
1506 {
1507 	int evtchn = evtchn_from_irq(irq);
1508 
1509 	if (VALID_EVTCHN(evtchn))
1510 		set_evtchn(evtchn);
1511 }
1512 
1513 bool xen_test_irq_pending(int irq)
1514 {
1515 	int evtchn = evtchn_from_irq(irq);
1516 	bool ret = false;
1517 
1518 	if (VALID_EVTCHN(evtchn))
1519 		ret = test_evtchn(evtchn);
1520 
1521 	return ret;
1522 }
1523 
1524 /* Poll waiting for an irq to become pending with timeout.  In the usual case,
1525  * the irq will be disabled so it won't deliver an interrupt. */
1526 void xen_poll_irq_timeout(int irq, u64 timeout)
1527 {
1528 	evtchn_port_t evtchn = evtchn_from_irq(irq);
1529 
1530 	if (VALID_EVTCHN(evtchn)) {
1531 		struct sched_poll poll;
1532 
1533 		poll.nr_ports = 1;
1534 		poll.timeout = timeout;
1535 		set_xen_guest_handle(poll.ports, &evtchn);
1536 
1537 		if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1538 			BUG();
1539 	}
1540 }
1541 EXPORT_SYMBOL(xen_poll_irq_timeout);
1542 /* Poll waiting for an irq to become pending.  In the usual case, the
1543  * irq will be disabled so it won't deliver an interrupt. */
1544 void xen_poll_irq(int irq)
1545 {
1546 	xen_poll_irq_timeout(irq, 0 /* no timeout */);
1547 }
1548 
1549 /* Check whether the IRQ line is shared with other guests. */
1550 int xen_test_irq_shared(int irq)
1551 {
1552 	struct irq_info *info = info_for_irq(irq);
1553 	struct physdev_irq_status_query irq_status;
1554 
1555 	if (WARN_ON(!info))
1556 		return -ENOENT;
1557 
1558 	irq_status.irq = info->u.pirq.pirq;
1559 
1560 	if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
1561 		return 0;
1562 	return !(irq_status.flags & XENIRQSTAT_shared);
1563 }
1564 EXPORT_SYMBOL_GPL(xen_test_irq_shared);
1565 
1566 void xen_irq_resume(void)
1567 {
1568 	unsigned int cpu;
1569 	struct irq_info *info;
1570 
1571 	/* New event-channel space is not 'live' yet. */
1572 	xen_evtchn_mask_all();
1573 	xen_evtchn_resume();
1574 
1575 	/* No IRQ <-> event-channel mappings. */
1576 	list_for_each_entry(info, &xen_irq_list_head, list)
1577 		info->evtchn = 0; /* zap event-channel binding */
1578 
1579 	clear_evtchn_to_irq_all();
1580 
1581 	for_each_possible_cpu(cpu) {
1582 		restore_cpu_virqs(cpu);
1583 		restore_cpu_ipis(cpu);
1584 	}
1585 
1586 	restore_pirqs();
1587 }
1588 
1589 static struct irq_chip xen_dynamic_chip __read_mostly = {
1590 	.name			= "xen-dyn",
1591 
1592 	.irq_disable		= disable_dynirq,
1593 	.irq_mask		= disable_dynirq,
1594 	.irq_unmask		= enable_dynirq,
1595 
1596 	.irq_ack		= ack_dynirq,
1597 	.irq_mask_ack		= mask_ack_dynirq,
1598 
1599 	.irq_set_affinity	= set_affinity_irq,
1600 	.irq_retrigger		= retrigger_dynirq,
1601 };
1602 
1603 static struct irq_chip xen_pirq_chip __read_mostly = {
1604 	.name			= "xen-pirq",
1605 
1606 	.irq_startup		= startup_pirq,
1607 	.irq_shutdown		= shutdown_pirq,
1608 	.irq_enable		= enable_pirq,
1609 	.irq_disable		= disable_pirq,
1610 
1611 	.irq_mask		= disable_dynirq,
1612 	.irq_unmask		= enable_dynirq,
1613 
1614 	.irq_ack		= eoi_pirq,
1615 	.irq_eoi		= eoi_pirq,
1616 	.irq_mask_ack		= mask_ack_pirq,
1617 
1618 	.irq_set_affinity	= set_affinity_irq,
1619 
1620 	.irq_retrigger		= retrigger_dynirq,
1621 };
1622 
1623 static struct irq_chip xen_percpu_chip __read_mostly = {
1624 	.name			= "xen-percpu",
1625 
1626 	.irq_disable		= disable_dynirq,
1627 	.irq_mask		= disable_dynirq,
1628 	.irq_unmask		= enable_dynirq,
1629 
1630 	.irq_ack		= ack_dynirq,
1631 };
1632 
1633 int xen_set_callback_via(uint64_t via)
1634 {
1635 	struct xen_hvm_param a;
1636 	a.domid = DOMID_SELF;
1637 	a.index = HVM_PARAM_CALLBACK_IRQ;
1638 	a.value = via;
1639 	return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1640 }
1641 EXPORT_SYMBOL_GPL(xen_set_callback_via);
1642 
1643 #ifdef CONFIG_XEN_PVHVM
1644 /* Vector callbacks are better than PCI interrupts to receive event
1645  * channel notifications because we can receive vector callbacks on any
1646  * vcpu and we don't need PCI support or APIC interactions. */
1647 void xen_callback_vector(void)
1648 {
1649 	int rc;
1650 	uint64_t callback_via;
1651 
1652 	if (xen_have_vector_callback) {
1653 		callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
1654 		rc = xen_set_callback_via(callback_via);
1655 		if (rc) {
1656 			pr_err("Request for Xen HVM callback vector failed\n");
1657 			xen_have_vector_callback = 0;
1658 			return;
1659 		}
1660 		pr_info("Xen HVM callback vector for event delivery is enabled\n");
1661 		/* in the restore case the vector has already been allocated */
1662 		if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
1663 			alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
1664 					xen_hvm_callback_vector);
1665 	}
1666 }
1667 #else
1668 void xen_callback_vector(void) {}
1669 #endif
1670 
1671 #undef MODULE_PARAM_PREFIX
1672 #define MODULE_PARAM_PREFIX "xen."
1673 
1674 static bool fifo_events = true;
1675 module_param(fifo_events, bool, 0);
1676 
1677 void __init xen_init_IRQ(void)
1678 {
1679 	int ret = -EINVAL;
1680 
1681 	if (fifo_events)
1682 		ret = xen_evtchn_fifo_init();
1683 	if (ret < 0)
1684 		xen_evtchn_2l_init();
1685 
1686 	evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()),
1687 				sizeof(*evtchn_to_irq), GFP_KERNEL);
1688 	BUG_ON(!evtchn_to_irq);
1689 
1690 	/* No event channels are 'live' right now. */
1691 	xen_evtchn_mask_all();
1692 
1693 	pirq_needs_eoi = pirq_needs_eoi_flag;
1694 
1695 #ifdef CONFIG_X86
1696 	if (xen_pv_domain()) {
1697 		irq_ctx_init(smp_processor_id());
1698 		if (xen_initial_domain())
1699 			pci_xen_initial_domain();
1700 	}
1701 	if (xen_feature(XENFEAT_hvm_callback_vector))
1702 		xen_callback_vector();
1703 
1704 	if (xen_hvm_domain()) {
1705 		native_init_IRQ();
1706 		/* pci_xen_hvm_init must be called after native_init_IRQ so that
1707 		 * __acpi_register_gsi can point at the right function */
1708 		pci_xen_hvm_init();
1709 	} else {
1710 		int rc;
1711 		struct physdev_pirq_eoi_gmfn eoi_gmfn;
1712 
1713 		pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
1714 		eoi_gmfn.gmfn = virt_to_gfn(pirq_eoi_map);
1715 		rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn);
1716 		if (rc != 0) {
1717 			free_page((unsigned long) pirq_eoi_map);
1718 			pirq_eoi_map = NULL;
1719 		} else
1720 			pirq_needs_eoi = pirq_check_eoi_map;
1721 	}
1722 #endif
1723 }
1724