Merge branches 'stable/irq.fairness' and 'stable/irq.ween_of_nr_irqs' of git://git...
[pandora-kernel.git] / drivers / xen / events.c
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 recieved, 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 #include <linux/linkage.h>
25 #include <linux/interrupt.h>
26 #include <linux/irq.h>
27 #include <linux/module.h>
28 #include <linux/string.h>
29 #include <linux/bootmem.h>
30 #include <linux/slab.h>
31 #include <linux/irqnr.h>
32 #include <linux/pci.h>
33
34 #include <asm/desc.h>
35 #include <asm/ptrace.h>
36 #include <asm/irq.h>
37 #include <asm/idle.h>
38 #include <asm/io_apic.h>
39 #include <asm/sync_bitops.h>
40 #include <asm/xen/pci.h>
41 #include <asm/xen/hypercall.h>
42 #include <asm/xen/hypervisor.h>
43
44 #include <xen/xen.h>
45 #include <xen/hvm.h>
46 #include <xen/xen-ops.h>
47 #include <xen/events.h>
48 #include <xen/interface/xen.h>
49 #include <xen/interface/event_channel.h>
50 #include <xen/interface/hvm/hvm_op.h>
51 #include <xen/interface/hvm/params.h>
52
53 /*
54  * This lock protects updates to the following mapping and reference-count
55  * arrays. The lock does not need to be acquired to read the mapping tables.
56  */
57 static DEFINE_SPINLOCK(irq_mapping_update_lock);
58
59 static LIST_HEAD(xen_irq_list_head);
60
61 /* IRQ <-> VIRQ mapping. */
62 static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
63
64 /* IRQ <-> IPI mapping */
65 static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
66
67 /* Interrupt types. */
68 enum xen_irq_type {
69         IRQT_UNBOUND = 0,
70         IRQT_PIRQ,
71         IRQT_VIRQ,
72         IRQT_IPI,
73         IRQT_EVTCHN
74 };
75
76 /*
77  * Packed IRQ information:
78  * type - enum xen_irq_type
79  * event channel - irq->event channel mapping
80  * cpu - cpu this event channel is bound to
81  * index - type-specific information:
82  *    PIRQ - vector, with MSB being "needs EIO", or physical IRQ of the HVM
83  *           guest, or GSI (real passthrough IRQ) of the device.
84  *    VIRQ - virq number
85  *    IPI - IPI vector
86  *    EVTCHN -
87  */
88 struct irq_info
89 {
90         struct list_head list;
91         enum xen_irq_type type; /* type */
92         unsigned irq;
93         unsigned short evtchn;  /* event channel */
94         unsigned short cpu;     /* cpu bound */
95
96         union {
97                 unsigned short virq;
98                 enum ipi_vector ipi;
99                 struct {
100                         unsigned short pirq;
101                         unsigned short gsi;
102                         unsigned char vector;
103                         unsigned char flags;
104                 } pirq;
105         } u;
106 };
107 #define PIRQ_NEEDS_EOI  (1 << 0)
108 #define PIRQ_SHAREABLE  (1 << 1)
109
110 static int *evtchn_to_irq;
111
112 static DEFINE_PER_CPU(unsigned long [NR_EVENT_CHANNELS/BITS_PER_LONG],
113                       cpu_evtchn_mask);
114
115 /* Xen will never allocate port zero for any purpose. */
116 #define VALID_EVTCHN(chn)       ((chn) != 0)
117
118 static struct irq_chip xen_dynamic_chip;
119 static struct irq_chip xen_percpu_chip;
120 static struct irq_chip xen_pirq_chip;
121
122 /* Get info for IRQ */
123 static struct irq_info *info_for_irq(unsigned irq)
124 {
125         return get_irq_data(irq);
126 }
127
128 /* Constructors for packed IRQ information. */
129 static void xen_irq_info_common_init(struct irq_info *info,
130                                      unsigned irq,
131                                      enum xen_irq_type type,
132                                      unsigned short evtchn,
133                                      unsigned short cpu)
134 {
135
136         BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
137
138         info->type = type;
139         info->irq = irq;
140         info->evtchn = evtchn;
141         info->cpu = cpu;
142
143         evtchn_to_irq[evtchn] = irq;
144 }
145
146 static void xen_irq_info_evtchn_init(unsigned irq,
147                                      unsigned short evtchn)
148 {
149         struct irq_info *info = info_for_irq(irq);
150
151         xen_irq_info_common_init(info, irq, IRQT_EVTCHN, evtchn, 0);
152 }
153
154 static void xen_irq_info_ipi_init(unsigned cpu,
155                                   unsigned irq,
156                                   unsigned short evtchn,
157                                   enum ipi_vector ipi)
158 {
159         struct irq_info *info = info_for_irq(irq);
160
161         xen_irq_info_common_init(info, irq, IRQT_IPI, evtchn, 0);
162
163         info->u.ipi = ipi;
164
165         per_cpu(ipi_to_irq, cpu)[ipi] = irq;
166 }
167
168 static void xen_irq_info_virq_init(unsigned cpu,
169                                    unsigned irq,
170                                    unsigned short evtchn,
171                                    unsigned short virq)
172 {
173         struct irq_info *info = info_for_irq(irq);
174
175         xen_irq_info_common_init(info, irq, IRQT_VIRQ, evtchn, 0);
176
177         info->u.virq = virq;
178
179         per_cpu(virq_to_irq, cpu)[virq] = irq;
180 }
181
182 static void xen_irq_info_pirq_init(unsigned irq,
183                                    unsigned short evtchn,
184                                    unsigned short pirq,
185                                    unsigned short gsi,
186                                    unsigned short vector,
187                                    unsigned char flags)
188 {
189         struct irq_info *info = info_for_irq(irq);
190
191         xen_irq_info_common_init(info, irq, IRQT_PIRQ, evtchn, 0);
192
193         info->u.pirq.pirq = pirq;
194         info->u.pirq.gsi = gsi;
195         info->u.pirq.vector = vector;
196         info->u.pirq.flags = flags;
197 }
198
199 /*
200  * Accessors for packed IRQ information.
201  */
202 static unsigned int evtchn_from_irq(unsigned irq)
203 {
204         if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))
205                 return 0;
206
207         return info_for_irq(irq)->evtchn;
208 }
209
210 unsigned irq_from_evtchn(unsigned int evtchn)
211 {
212         return evtchn_to_irq[evtchn];
213 }
214 EXPORT_SYMBOL_GPL(irq_from_evtchn);
215
216 static enum ipi_vector ipi_from_irq(unsigned irq)
217 {
218         struct irq_info *info = info_for_irq(irq);
219
220         BUG_ON(info == NULL);
221         BUG_ON(info->type != IRQT_IPI);
222
223         return info->u.ipi;
224 }
225
226 static unsigned virq_from_irq(unsigned irq)
227 {
228         struct irq_info *info = info_for_irq(irq);
229
230         BUG_ON(info == NULL);
231         BUG_ON(info->type != IRQT_VIRQ);
232
233         return info->u.virq;
234 }
235
236 static unsigned pirq_from_irq(unsigned irq)
237 {
238         struct irq_info *info = info_for_irq(irq);
239
240         BUG_ON(info == NULL);
241         BUG_ON(info->type != IRQT_PIRQ);
242
243         return info->u.pirq.pirq;
244 }
245
246 static enum xen_irq_type type_from_irq(unsigned irq)
247 {
248         return info_for_irq(irq)->type;
249 }
250
251 static unsigned cpu_from_irq(unsigned irq)
252 {
253         return info_for_irq(irq)->cpu;
254 }
255
256 static unsigned int cpu_from_evtchn(unsigned int evtchn)
257 {
258         int irq = evtchn_to_irq[evtchn];
259         unsigned ret = 0;
260
261         if (irq != -1)
262                 ret = cpu_from_irq(irq);
263
264         return ret;
265 }
266
267 static bool pirq_needs_eoi(unsigned irq)
268 {
269         struct irq_info *info = info_for_irq(irq);
270
271         BUG_ON(info->type != IRQT_PIRQ);
272
273         return info->u.pirq.flags & PIRQ_NEEDS_EOI;
274 }
275
276 static inline unsigned long active_evtchns(unsigned int cpu,
277                                            struct shared_info *sh,
278                                            unsigned int idx)
279 {
280         return (sh->evtchn_pending[idx] &
281                 per_cpu(cpu_evtchn_mask, cpu)[idx] &
282                 ~sh->evtchn_mask[idx]);
283 }
284
285 static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
286 {
287         int irq = evtchn_to_irq[chn];
288
289         BUG_ON(irq == -1);
290 #ifdef CONFIG_SMP
291         cpumask_copy(irq_to_desc(irq)->irq_data.affinity, cpumask_of(cpu));
292 #endif
293
294         clear_bit(chn, per_cpu(cpu_evtchn_mask, cpu_from_irq(irq)));
295         set_bit(chn, per_cpu(cpu_evtchn_mask, cpu));
296
297         info_for_irq(irq)->cpu = cpu;
298 }
299
300 static void init_evtchn_cpu_bindings(void)
301 {
302         int i;
303 #ifdef CONFIG_SMP
304         struct irq_info *info;
305
306         /* By default all event channels notify CPU#0. */
307         list_for_each_entry(info, &xen_irq_list_head, list) {
308                 struct irq_desc *desc = irq_to_desc(info->irq);
309                 cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
310         }
311 #endif
312
313         for_each_possible_cpu(i)
314                 memset(per_cpu(cpu_evtchn_mask, i),
315                        (i == 0) ? ~0 : 0, sizeof(*per_cpu(cpu_evtchn_mask, i)));
316 }
317
318 static inline void clear_evtchn(int port)
319 {
320         struct shared_info *s = HYPERVISOR_shared_info;
321         sync_clear_bit(port, &s->evtchn_pending[0]);
322 }
323
324 static inline void set_evtchn(int port)
325 {
326         struct shared_info *s = HYPERVISOR_shared_info;
327         sync_set_bit(port, &s->evtchn_pending[0]);
328 }
329
330 static inline int test_evtchn(int port)
331 {
332         struct shared_info *s = HYPERVISOR_shared_info;
333         return sync_test_bit(port, &s->evtchn_pending[0]);
334 }
335
336
337 /**
338  * notify_remote_via_irq - send event to remote end of event channel via irq
339  * @irq: irq of event channel to send event to
340  *
341  * Unlike notify_remote_via_evtchn(), this is safe to use across
342  * save/restore. Notifications on a broken connection are silently
343  * dropped.
344  */
345 void notify_remote_via_irq(int irq)
346 {
347         int evtchn = evtchn_from_irq(irq);
348
349         if (VALID_EVTCHN(evtchn))
350                 notify_remote_via_evtchn(evtchn);
351 }
352 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
353
354 static void mask_evtchn(int port)
355 {
356         struct shared_info *s = HYPERVISOR_shared_info;
357         sync_set_bit(port, &s->evtchn_mask[0]);
358 }
359
360 static void unmask_evtchn(int port)
361 {
362         struct shared_info *s = HYPERVISOR_shared_info;
363         unsigned int cpu = get_cpu();
364
365         BUG_ON(!irqs_disabled());
366
367         /* Slow path (hypercall) if this is a non-local port. */
368         if (unlikely(cpu != cpu_from_evtchn(port))) {
369                 struct evtchn_unmask unmask = { .port = port };
370                 (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
371         } else {
372                 struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
373
374                 sync_clear_bit(port, &s->evtchn_mask[0]);
375
376                 /*
377                  * The following is basically the equivalent of
378                  * 'hw_resend_irq'. Just like a real IO-APIC we 'lose
379                  * the interrupt edge' if the channel is masked.
380                  */
381                 if (sync_test_bit(port, &s->evtchn_pending[0]) &&
382                     !sync_test_and_set_bit(port / BITS_PER_LONG,
383                                            &vcpu_info->evtchn_pending_sel))
384                         vcpu_info->evtchn_upcall_pending = 1;
385         }
386
387         put_cpu();
388 }
389
390 static void xen_irq_init(unsigned irq)
391 {
392         struct irq_info *info;
393         struct irq_desc *desc = irq_to_desc(irq);
394
395 #ifdef CONFIG_SMP
396         /* By default all event channels notify CPU#0. */
397         cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
398 #endif
399
400         info = kzalloc(sizeof(*info), GFP_KERNEL);
401         if (info == NULL)
402                 panic("Unable to allocate metadata for IRQ%d\n", irq);
403
404         info->type = IRQT_UNBOUND;
405
406         set_irq_data(irq, info);
407
408         list_add_tail(&info->list, &xen_irq_list_head);
409 }
410
411 static int __must_check xen_allocate_irq_dynamic(void)
412 {
413         int first = 0;
414         int irq;
415
416 #ifdef CONFIG_X86_IO_APIC
417         /*
418          * For an HVM guest or domain 0 which see "real" (emulated or
419          * actual repectively) GSIs we allocate dynamic IRQs
420          * e.g. those corresponding to event channels or MSIs
421          * etc. from the range above those "real" GSIs to avoid
422          * collisions.
423          */
424         if (xen_initial_domain() || xen_hvm_domain())
425                 first = get_nr_irqs_gsi();
426 #endif
427
428         irq = irq_alloc_desc_from(first, -1);
429
430         xen_irq_init(irq);
431
432         return irq;
433 }
434
435 static int __must_check xen_allocate_irq_gsi(unsigned gsi)
436 {
437         int irq;
438
439         /*
440          * A PV guest has no concept of a GSI (since it has no ACPI
441          * nor access to/knowledge of the physical APICs). Therefore
442          * all IRQs are dynamically allocated from the entire IRQ
443          * space.
444          */
445         if (xen_pv_domain() && !xen_initial_domain())
446                 return xen_allocate_irq_dynamic();
447
448         /* Legacy IRQ descriptors are already allocated by the arch. */
449         if (gsi < NR_IRQS_LEGACY)
450                 irq = gsi;
451         else
452                 irq = irq_alloc_desc_at(gsi, -1);
453
454         xen_irq_init(irq);
455
456         return irq;
457 }
458
459 static void xen_free_irq(unsigned irq)
460 {
461         struct irq_info *info = get_irq_data(irq);
462
463         list_del(&info->list);
464
465         set_irq_data(irq, NULL);
466
467         kfree(info);
468
469         /* Legacy IRQ descriptors are managed by the arch. */
470         if (irq < NR_IRQS_LEGACY)
471                 return;
472
473         irq_free_desc(irq);
474 }
475
476 static void pirq_unmask_notify(int irq)
477 {
478         struct physdev_eoi eoi = { .irq = pirq_from_irq(irq) };
479
480         if (unlikely(pirq_needs_eoi(irq))) {
481                 int rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
482                 WARN_ON(rc);
483         }
484 }
485
486 static void pirq_query_unmask(int irq)
487 {
488         struct physdev_irq_status_query irq_status;
489         struct irq_info *info = info_for_irq(irq);
490
491         BUG_ON(info->type != IRQT_PIRQ);
492
493         irq_status.irq = pirq_from_irq(irq);
494         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
495                 irq_status.flags = 0;
496
497         info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
498         if (irq_status.flags & XENIRQSTAT_needs_eoi)
499                 info->u.pirq.flags |= PIRQ_NEEDS_EOI;
500 }
501
502 static bool probing_irq(int irq)
503 {
504         struct irq_desc *desc = irq_to_desc(irq);
505
506         return desc && desc->action == NULL;
507 }
508
509 static unsigned int __startup_pirq(unsigned int irq)
510 {
511         struct evtchn_bind_pirq bind_pirq;
512         struct irq_info *info = info_for_irq(irq);
513         int evtchn = evtchn_from_irq(irq);
514         int rc;
515
516         BUG_ON(info->type != IRQT_PIRQ);
517
518         if (VALID_EVTCHN(evtchn))
519                 goto out;
520
521         bind_pirq.pirq = pirq_from_irq(irq);
522         /* NB. We are happy to share unless we are probing. */
523         bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
524                                         BIND_PIRQ__WILL_SHARE : 0;
525         rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
526         if (rc != 0) {
527                 if (!probing_irq(irq))
528                         printk(KERN_INFO "Failed to obtain physical IRQ %d\n",
529                                irq);
530                 return 0;
531         }
532         evtchn = bind_pirq.port;
533
534         pirq_query_unmask(irq);
535
536         evtchn_to_irq[evtchn] = irq;
537         bind_evtchn_to_cpu(evtchn, 0);
538         info->evtchn = evtchn;
539
540 out:
541         unmask_evtchn(evtchn);
542         pirq_unmask_notify(irq);
543
544         return 0;
545 }
546
547 static unsigned int startup_pirq(struct irq_data *data)
548 {
549         return __startup_pirq(data->irq);
550 }
551
552 static void shutdown_pirq(struct irq_data *data)
553 {
554         struct evtchn_close close;
555         unsigned int irq = data->irq;
556         struct irq_info *info = info_for_irq(irq);
557         int evtchn = evtchn_from_irq(irq);
558
559         BUG_ON(info->type != IRQT_PIRQ);
560
561         if (!VALID_EVTCHN(evtchn))
562                 return;
563
564         mask_evtchn(evtchn);
565
566         close.port = evtchn;
567         if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
568                 BUG();
569
570         bind_evtchn_to_cpu(evtchn, 0);
571         evtchn_to_irq[evtchn] = -1;
572         info->evtchn = 0;
573 }
574
575 static void enable_pirq(struct irq_data *data)
576 {
577         startup_pirq(data);
578 }
579
580 static void disable_pirq(struct irq_data *data)
581 {
582 }
583
584 static void ack_pirq(struct irq_data *data)
585 {
586         int evtchn = evtchn_from_irq(data->irq);
587
588         move_native_irq(data->irq);
589
590         if (VALID_EVTCHN(evtchn)) {
591                 mask_evtchn(evtchn);
592                 clear_evtchn(evtchn);
593         }
594 }
595
596 static int find_irq_by_gsi(unsigned gsi)
597 {
598         struct irq_info *info;
599
600         list_for_each_entry(info, &xen_irq_list_head, list) {
601                 if (info->type != IRQT_PIRQ)
602                         continue;
603
604                 if (info->u.pirq.gsi == gsi)
605                         return info->irq;
606         }
607
608         return -1;
609 }
610
611 int xen_allocate_pirq_gsi(unsigned gsi)
612 {
613         return gsi;
614 }
615
616 /*
617  * Do not make any assumptions regarding the relationship between the
618  * IRQ number returned here and the Xen pirq argument.
619  *
620  * Note: We don't assign an event channel until the irq actually started
621  * up.  Return an existing irq if we've already got one for the gsi.
622  */
623 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
624                              unsigned pirq, int shareable, char *name)
625 {
626         int irq = -1;
627         struct physdev_irq irq_op;
628
629         spin_lock(&irq_mapping_update_lock);
630
631         irq = find_irq_by_gsi(gsi);
632         if (irq != -1) {
633                 printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n",
634                        irq, gsi);
635                 goto out;       /* XXX need refcount? */
636         }
637
638         irq = xen_allocate_irq_gsi(gsi);
639         if (irq < 0)
640                 goto out;
641
642         set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
643                                       handle_level_irq, name);
644
645         irq_op.irq = irq;
646         irq_op.vector = 0;
647
648         /* Only the privileged domain can do this. For non-priv, the pcifront
649          * driver provides a PCI bus that does the call to do exactly
650          * this in the priv domain. */
651         if (xen_initial_domain() &&
652             HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
653                 xen_free_irq(irq);
654                 irq = -ENOSPC;
655                 goto out;
656         }
657
658         xen_irq_info_pirq_init(irq, 0, pirq, gsi, irq_op.vector,
659                                shareable ? PIRQ_SHAREABLE : 0);
660
661 out:
662         spin_unlock(&irq_mapping_update_lock);
663
664         return irq;
665 }
666
667 #ifdef CONFIG_PCI_MSI
668 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
669 {
670         int rc;
671         struct physdev_get_free_pirq op_get_free_pirq;
672
673         op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
674         rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
675
676         WARN_ONCE(rc == -ENOSYS,
677                   "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
678
679         return rc ? -1 : op_get_free_pirq.pirq;
680 }
681
682 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
683                              int pirq, int vector, const char *name)
684 {
685         int irq, ret;
686
687         spin_lock(&irq_mapping_update_lock);
688
689         irq = xen_allocate_irq_dynamic();
690         if (irq == -1)
691                 goto out;
692
693         set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
694                                       handle_level_irq, name);
695
696         xen_irq_info_pirq_init(irq, 0, pirq, 0, vector, 0);
697         ret = irq_set_msi_desc(irq, msidesc);
698         if (ret < 0)
699                 goto error_irq;
700 out:
701         spin_unlock(&irq_mapping_update_lock);
702         return irq;
703 error_irq:
704         spin_unlock(&irq_mapping_update_lock);
705         xen_free_irq(irq);
706         return -1;
707 }
708 #endif
709
710 int xen_destroy_irq(int irq)
711 {
712         struct irq_desc *desc;
713         struct physdev_unmap_pirq unmap_irq;
714         struct irq_info *info = info_for_irq(irq);
715         int rc = -ENOENT;
716
717         spin_lock(&irq_mapping_update_lock);
718
719         desc = irq_to_desc(irq);
720         if (!desc)
721                 goto out;
722
723         if (xen_initial_domain()) {
724                 unmap_irq.pirq = info->u.pirq.pirq;
725                 unmap_irq.domid = DOMID_SELF;
726                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
727                 if (rc) {
728                         printk(KERN_WARNING "unmap irq failed %d\n", rc);
729                         goto out;
730                 }
731         }
732
733         xen_free_irq(irq);
734
735 out:
736         spin_unlock(&irq_mapping_update_lock);
737         return rc;
738 }
739
740 int xen_irq_from_pirq(unsigned pirq)
741 {
742         int irq;
743
744         struct irq_info *info;
745
746         spin_lock(&irq_mapping_update_lock);
747
748         list_for_each_entry(info, &xen_irq_list_head, list) {
749                 if (info == NULL || info->type != IRQT_PIRQ)
750                         continue;
751                 irq = info->irq;
752                 if (info->u.pirq.pirq == pirq)
753                         goto out;
754         }
755         irq = -1;
756 out:
757         spin_unlock(&irq_mapping_update_lock);
758
759         return irq;
760 }
761
762 int bind_evtchn_to_irq(unsigned int evtchn)
763 {
764         int irq;
765
766         spin_lock(&irq_mapping_update_lock);
767
768         irq = evtchn_to_irq[evtchn];
769
770         if (irq == -1) {
771                 irq = xen_allocate_irq_dynamic();
772                 if (irq == -1)
773                         goto out;
774
775                 set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
776                                               handle_fasteoi_irq, "event");
777
778                 xen_irq_info_evtchn_init(irq, evtchn);
779         }
780
781 out:
782         spin_unlock(&irq_mapping_update_lock);
783
784         return irq;
785 }
786 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
787
788 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
789 {
790         struct evtchn_bind_ipi bind_ipi;
791         int evtchn, irq;
792
793         spin_lock(&irq_mapping_update_lock);
794
795         irq = per_cpu(ipi_to_irq, cpu)[ipi];
796
797         if (irq == -1) {
798                 irq = xen_allocate_irq_dynamic();
799                 if (irq < 0)
800                         goto out;
801
802                 set_irq_chip_and_handler_name(irq, &xen_percpu_chip,
803                                               handle_percpu_irq, "ipi");
804
805                 bind_ipi.vcpu = cpu;
806                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
807                                                 &bind_ipi) != 0)
808                         BUG();
809                 evtchn = bind_ipi.port;
810
811                 xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
812
813                 bind_evtchn_to_cpu(evtchn, cpu);
814         }
815
816  out:
817         spin_unlock(&irq_mapping_update_lock);
818         return irq;
819 }
820
821 static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
822                                           unsigned int remote_port)
823 {
824         struct evtchn_bind_interdomain bind_interdomain;
825         int err;
826
827         bind_interdomain.remote_dom  = remote_domain;
828         bind_interdomain.remote_port = remote_port;
829
830         err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
831                                           &bind_interdomain);
832
833         return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
834 }
835
836
837 int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
838 {
839         struct evtchn_bind_virq bind_virq;
840         int evtchn, irq;
841
842         spin_lock(&irq_mapping_update_lock);
843
844         irq = per_cpu(virq_to_irq, cpu)[virq];
845
846         if (irq == -1) {
847                 irq = xen_allocate_irq_dynamic();
848                 if (irq == -1)
849                         goto out;
850
851                 set_irq_chip_and_handler_name(irq, &xen_percpu_chip,
852                                               handle_percpu_irq, "virq");
853
854                 bind_virq.virq = virq;
855                 bind_virq.vcpu = cpu;
856                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
857                                                 &bind_virq) != 0)
858                         BUG();
859                 evtchn = bind_virq.port;
860
861                 xen_irq_info_virq_init(cpu, irq, evtchn, virq);
862
863                 bind_evtchn_to_cpu(evtchn, cpu);
864         }
865
866 out:
867         spin_unlock(&irq_mapping_update_lock);
868
869         return irq;
870 }
871
872 static void unbind_from_irq(unsigned int irq)
873 {
874         struct evtchn_close close;
875         int evtchn = evtchn_from_irq(irq);
876
877         spin_lock(&irq_mapping_update_lock);
878
879         if (VALID_EVTCHN(evtchn)) {
880                 close.port = evtchn;
881                 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
882                         BUG();
883
884                 switch (type_from_irq(irq)) {
885                 case IRQT_VIRQ:
886                         per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
887                                 [virq_from_irq(irq)] = -1;
888                         break;
889                 case IRQT_IPI:
890                         per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn))
891                                 [ipi_from_irq(irq)] = -1;
892                         break;
893                 default:
894                         break;
895                 }
896
897                 /* Closed ports are implicitly re-bound to VCPU0. */
898                 bind_evtchn_to_cpu(evtchn, 0);
899
900                 evtchn_to_irq[evtchn] = -1;
901         }
902
903         BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
904
905         xen_free_irq(irq);
906
907         spin_unlock(&irq_mapping_update_lock);
908 }
909
910 int bind_evtchn_to_irqhandler(unsigned int evtchn,
911                               irq_handler_t handler,
912                               unsigned long irqflags,
913                               const char *devname, void *dev_id)
914 {
915         unsigned int irq;
916         int retval;
917
918         irq = bind_evtchn_to_irq(evtchn);
919         if (irq < 0)
920                 return irq;
921         retval = request_irq(irq, handler, irqflags, devname, dev_id);
922         if (retval != 0) {
923                 unbind_from_irq(irq);
924                 return retval;
925         }
926
927         return irq;
928 }
929 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
930
931 int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
932                                           unsigned int remote_port,
933                                           irq_handler_t handler,
934                                           unsigned long irqflags,
935                                           const char *devname,
936                                           void *dev_id)
937 {
938         int irq, retval;
939
940         irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
941         if (irq < 0)
942                 return irq;
943
944         retval = request_irq(irq, handler, irqflags, devname, dev_id);
945         if (retval != 0) {
946                 unbind_from_irq(irq);
947                 return retval;
948         }
949
950         return irq;
951 }
952 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
953
954 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
955                             irq_handler_t handler,
956                             unsigned long irqflags, const char *devname, void *dev_id)
957 {
958         unsigned int irq;
959         int retval;
960
961         irq = bind_virq_to_irq(virq, cpu);
962         if (irq < 0)
963                 return irq;
964         retval = request_irq(irq, handler, irqflags, devname, dev_id);
965         if (retval != 0) {
966                 unbind_from_irq(irq);
967                 return retval;
968         }
969
970         return irq;
971 }
972 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
973
974 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
975                            unsigned int cpu,
976                            irq_handler_t handler,
977                            unsigned long irqflags,
978                            const char *devname,
979                            void *dev_id)
980 {
981         int irq, retval;
982
983         irq = bind_ipi_to_irq(ipi, cpu);
984         if (irq < 0)
985                 return irq;
986
987         irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME;
988         retval = request_irq(irq, handler, irqflags, devname, dev_id);
989         if (retval != 0) {
990                 unbind_from_irq(irq);
991                 return retval;
992         }
993
994         return irq;
995 }
996
997 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
998 {
999         free_irq(irq, dev_id);
1000         unbind_from_irq(irq);
1001 }
1002 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
1003
1004 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
1005 {
1006         int irq = per_cpu(ipi_to_irq, cpu)[vector];
1007         BUG_ON(irq < 0);
1008         notify_remote_via_irq(irq);
1009 }
1010
1011 irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
1012 {
1013         struct shared_info *sh = HYPERVISOR_shared_info;
1014         int cpu = smp_processor_id();
1015         unsigned long *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu);
1016         int i;
1017         unsigned long flags;
1018         static DEFINE_SPINLOCK(debug_lock);
1019         struct vcpu_info *v;
1020
1021         spin_lock_irqsave(&debug_lock, flags);
1022
1023         printk("\nvcpu %d\n  ", cpu);
1024
1025         for_each_online_cpu(i) {
1026                 int pending;
1027                 v = per_cpu(xen_vcpu, i);
1028                 pending = (get_irq_regs() && i == cpu)
1029                         ? xen_irqs_disabled(get_irq_regs())
1030                         : v->evtchn_upcall_mask;
1031                 printk("%d: masked=%d pending=%d event_sel %0*lx\n  ", i,
1032                        pending, v->evtchn_upcall_pending,
1033                        (int)(sizeof(v->evtchn_pending_sel)*2),
1034                        v->evtchn_pending_sel);
1035         }
1036         v = per_cpu(xen_vcpu, cpu);
1037
1038         printk("\npending:\n   ");
1039         for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
1040                 printk("%0*lx%s", (int)sizeof(sh->evtchn_pending[0])*2,
1041                        sh->evtchn_pending[i],
1042                        i % 8 == 0 ? "\n   " : " ");
1043         printk("\nglobal mask:\n   ");
1044         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
1045                 printk("%0*lx%s",
1046                        (int)(sizeof(sh->evtchn_mask[0])*2),
1047                        sh->evtchn_mask[i],
1048                        i % 8 == 0 ? "\n   " : " ");
1049
1050         printk("\nglobally unmasked:\n   ");
1051         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
1052                 printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
1053                        sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
1054                        i % 8 == 0 ? "\n   " : " ");
1055
1056         printk("\nlocal cpu%d mask:\n   ", cpu);
1057         for (i = (NR_EVENT_CHANNELS/BITS_PER_LONG)-1; i >= 0; i--)
1058                 printk("%0*lx%s", (int)(sizeof(cpu_evtchn[0])*2),
1059                        cpu_evtchn[i],
1060                        i % 8 == 0 ? "\n   " : " ");
1061
1062         printk("\nlocally unmasked:\n   ");
1063         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) {
1064                 unsigned long pending = sh->evtchn_pending[i]
1065                         & ~sh->evtchn_mask[i]
1066                         & cpu_evtchn[i];
1067                 printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
1068                        pending, i % 8 == 0 ? "\n   " : " ");
1069         }
1070
1071         printk("\npending list:\n");
1072         for (i = 0; i < NR_EVENT_CHANNELS; i++) {
1073                 if (sync_test_bit(i, sh->evtchn_pending)) {
1074                         int word_idx = i / BITS_PER_LONG;
1075                         printk("  %d: event %d -> irq %d%s%s%s\n",
1076                                cpu_from_evtchn(i), i,
1077                                evtchn_to_irq[i],
1078                                sync_test_bit(word_idx, &v->evtchn_pending_sel)
1079                                              ? "" : " l2-clear",
1080                                !sync_test_bit(i, sh->evtchn_mask)
1081                                              ? "" : " globally-masked",
1082                                sync_test_bit(i, cpu_evtchn)
1083                                              ? "" : " locally-masked");
1084                 }
1085         }
1086
1087         spin_unlock_irqrestore(&debug_lock, flags);
1088
1089         return IRQ_HANDLED;
1090 }
1091
1092 static DEFINE_PER_CPU(unsigned, xed_nesting_count);
1093 static DEFINE_PER_CPU(unsigned int, current_word_idx);
1094 static DEFINE_PER_CPU(unsigned int, current_bit_idx);
1095
1096 /*
1097  * Mask out the i least significant bits of w
1098  */
1099 #define MASK_LSBS(w, i) (w & ((~0UL) << i))
1100
1101 /*
1102  * Search the CPUs pending events bitmasks.  For each one found, map
1103  * the event number to an irq, and feed it into do_IRQ() for
1104  * handling.
1105  *
1106  * Xen uses a two-level bitmap to speed searching.  The first level is
1107  * a bitset of words which contain pending event bits.  The second
1108  * level is a bitset of pending events themselves.
1109  */
1110 static void __xen_evtchn_do_upcall(void)
1111 {
1112         int start_word_idx, start_bit_idx;
1113         int word_idx, bit_idx;
1114         int i;
1115         int cpu = get_cpu();
1116         struct shared_info *s = HYPERVISOR_shared_info;
1117         struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1118         unsigned count;
1119
1120         do {
1121                 unsigned long pending_words;
1122
1123                 vcpu_info->evtchn_upcall_pending = 0;
1124
1125                 if (__this_cpu_inc_return(xed_nesting_count) - 1)
1126                         goto out;
1127
1128 #ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
1129                 /* Clear master flag /before/ clearing selector flag. */
1130                 wmb();
1131 #endif
1132                 pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
1133
1134                 start_word_idx = __this_cpu_read(current_word_idx);
1135                 start_bit_idx = __this_cpu_read(current_bit_idx);
1136
1137                 word_idx = start_word_idx;
1138
1139                 for (i = 0; pending_words != 0; i++) {
1140                         unsigned long pending_bits;
1141                         unsigned long words;
1142
1143                         words = MASK_LSBS(pending_words, word_idx);
1144
1145                         /*
1146                          * If we masked out all events, wrap to beginning.
1147                          */
1148                         if (words == 0) {
1149                                 word_idx = 0;
1150                                 bit_idx = 0;
1151                                 continue;
1152                         }
1153                         word_idx = __ffs(words);
1154
1155                         pending_bits = active_evtchns(cpu, s, word_idx);
1156                         bit_idx = 0; /* usually scan entire word from start */
1157                         if (word_idx == start_word_idx) {
1158                                 /* We scan the starting word in two parts */
1159                                 if (i == 0)
1160                                         /* 1st time: start in the middle */
1161                                         bit_idx = start_bit_idx;
1162                                 else
1163                                         /* 2nd time: mask bits done already */
1164                                         bit_idx &= (1UL << start_bit_idx) - 1;
1165                         }
1166
1167                         do {
1168                                 unsigned long bits;
1169                                 int port, irq;
1170                                 struct irq_desc *desc;
1171
1172                                 bits = MASK_LSBS(pending_bits, bit_idx);
1173
1174                                 /* If we masked out all events, move on. */
1175                                 if (bits == 0)
1176                                         break;
1177
1178                                 bit_idx = __ffs(bits);
1179
1180                                 /* Process port. */
1181                                 port = (word_idx * BITS_PER_LONG) + bit_idx;
1182                                 irq = evtchn_to_irq[port];
1183
1184                                 mask_evtchn(port);
1185                                 clear_evtchn(port);
1186
1187                                 if (irq != -1) {
1188                                         desc = irq_to_desc(irq);
1189                                         if (desc)
1190                                                 generic_handle_irq_desc(irq, desc);
1191                                 }
1192
1193                                 bit_idx = (bit_idx + 1) % BITS_PER_LONG;
1194
1195                                 /* Next caller starts at last processed + 1 */
1196                                 __this_cpu_write(current_word_idx,
1197                                                  bit_idx ? word_idx :
1198                                                  (word_idx+1) % BITS_PER_LONG);
1199                                 __this_cpu_write(current_bit_idx, bit_idx);
1200                         } while (bit_idx != 0);
1201
1202                         /* Scan start_l1i twice; all others once. */
1203                         if ((word_idx != start_word_idx) || (i != 0))
1204                                 pending_words &= ~(1UL << word_idx);
1205
1206                         word_idx = (word_idx + 1) % BITS_PER_LONG;
1207                 }
1208
1209                 BUG_ON(!irqs_disabled());
1210
1211                 count = __this_cpu_read(xed_nesting_count);
1212                 __this_cpu_write(xed_nesting_count, 0);
1213         } while (count != 1 || vcpu_info->evtchn_upcall_pending);
1214
1215 out:
1216
1217         put_cpu();
1218 }
1219
1220 void xen_evtchn_do_upcall(struct pt_regs *regs)
1221 {
1222         struct pt_regs *old_regs = set_irq_regs(regs);
1223
1224         exit_idle();
1225         irq_enter();
1226
1227         __xen_evtchn_do_upcall();
1228
1229         irq_exit();
1230         set_irq_regs(old_regs);
1231 }
1232
1233 void xen_hvm_evtchn_do_upcall(void)
1234 {
1235         __xen_evtchn_do_upcall();
1236 }
1237 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1238
1239 /* Rebind a new event channel to an existing irq. */
1240 void rebind_evtchn_irq(int evtchn, int irq)
1241 {
1242         struct irq_info *info = info_for_irq(irq);
1243
1244         /* Make sure the irq is masked, since the new event channel
1245            will also be masked. */
1246         disable_irq(irq);
1247
1248         spin_lock(&irq_mapping_update_lock);
1249
1250         /* After resume the irq<->evtchn mappings are all cleared out */
1251         BUG_ON(evtchn_to_irq[evtchn] != -1);
1252         /* Expect irq to have been bound before,
1253            so there should be a proper type */
1254         BUG_ON(info->type == IRQT_UNBOUND);
1255
1256         xen_irq_info_evtchn_init(irq, evtchn);
1257
1258         spin_unlock(&irq_mapping_update_lock);
1259
1260         /* new event channels are always bound to cpu 0 */
1261         irq_set_affinity(irq, cpumask_of(0));
1262
1263         /* Unmask the event channel. */
1264         enable_irq(irq);
1265 }
1266
1267 /* Rebind an evtchn so that it gets delivered to a specific cpu */
1268 static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
1269 {
1270         struct evtchn_bind_vcpu bind_vcpu;
1271         int evtchn = evtchn_from_irq(irq);
1272
1273         if (!VALID_EVTCHN(evtchn))
1274                 return -1;
1275
1276         /*
1277          * Events delivered via platform PCI interrupts are always
1278          * routed to vcpu 0 and hence cannot be rebound.
1279          */
1280         if (xen_hvm_domain() && !xen_have_vector_callback)
1281                 return -1;
1282
1283         /* Send future instances of this interrupt to other vcpu. */
1284         bind_vcpu.port = evtchn;
1285         bind_vcpu.vcpu = tcpu;
1286
1287         /*
1288          * If this fails, it usually just indicates that we're dealing with a
1289          * virq or IPI channel, which don't actually need to be rebound. Ignore
1290          * it, but don't do the xenlinux-level rebind in that case.
1291          */
1292         if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1293                 bind_evtchn_to_cpu(evtchn, tcpu);
1294
1295         return 0;
1296 }
1297
1298 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1299                             bool force)
1300 {
1301         unsigned tcpu = cpumask_first(dest);
1302
1303         return rebind_irq_to_cpu(data->irq, tcpu);
1304 }
1305
1306 int resend_irq_on_evtchn(unsigned int irq)
1307 {
1308         int masked, evtchn = evtchn_from_irq(irq);
1309         struct shared_info *s = HYPERVISOR_shared_info;
1310
1311         if (!VALID_EVTCHN(evtchn))
1312                 return 1;
1313
1314         masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
1315         sync_set_bit(evtchn, s->evtchn_pending);
1316         if (!masked)
1317                 unmask_evtchn(evtchn);
1318
1319         return 1;
1320 }
1321
1322 static void enable_dynirq(struct irq_data *data)
1323 {
1324         int evtchn = evtchn_from_irq(data->irq);
1325
1326         if (VALID_EVTCHN(evtchn))
1327                 unmask_evtchn(evtchn);
1328 }
1329
1330 static void disable_dynirq(struct irq_data *data)
1331 {
1332         int evtchn = evtchn_from_irq(data->irq);
1333
1334         if (VALID_EVTCHN(evtchn))
1335                 mask_evtchn(evtchn);
1336 }
1337
1338 static void ack_dynirq(struct irq_data *data)
1339 {
1340         int evtchn = evtchn_from_irq(data->irq);
1341
1342         move_masked_irq(data->irq);
1343
1344         if (VALID_EVTCHN(evtchn))
1345                 unmask_evtchn(evtchn);
1346 }
1347
1348 static int retrigger_dynirq(struct irq_data *data)
1349 {
1350         int evtchn = evtchn_from_irq(data->irq);
1351         struct shared_info *sh = HYPERVISOR_shared_info;
1352         int ret = 0;
1353
1354         if (VALID_EVTCHN(evtchn)) {
1355                 int masked;
1356
1357                 masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
1358                 sync_set_bit(evtchn, sh->evtchn_pending);
1359                 if (!masked)
1360                         unmask_evtchn(evtchn);
1361                 ret = 1;
1362         }
1363
1364         return ret;
1365 }
1366
1367 static void restore_pirqs(void)
1368 {
1369         int pirq, rc, irq, gsi;
1370         struct physdev_map_pirq map_irq;
1371         struct irq_info *info;
1372
1373         list_for_each_entry(info, &xen_irq_list_head, list) {
1374                 if (info->type != IRQT_PIRQ)
1375                         continue;
1376
1377                 pirq = info->u.pirq.pirq;
1378                 gsi = info->u.pirq.gsi;
1379                 irq = info->irq;
1380
1381                 /* save/restore of PT devices doesn't work, so at this point the
1382                  * only devices present are GSI based emulated devices */
1383                 if (!gsi)
1384                         continue;
1385
1386                 map_irq.domid = DOMID_SELF;
1387                 map_irq.type = MAP_PIRQ_TYPE_GSI;
1388                 map_irq.index = gsi;
1389                 map_irq.pirq = pirq;
1390
1391                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1392                 if (rc) {
1393                         printk(KERN_WARNING "xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1394                                         gsi, irq, pirq, rc);
1395                         xen_free_irq(irq);
1396                         continue;
1397                 }
1398
1399                 printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1400
1401                 __startup_pirq(irq);
1402         }
1403 }
1404
1405 static void restore_cpu_virqs(unsigned int cpu)
1406 {
1407         struct evtchn_bind_virq bind_virq;
1408         int virq, irq, evtchn;
1409
1410         for (virq = 0; virq < NR_VIRQS; virq++) {
1411                 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1412                         continue;
1413
1414                 BUG_ON(virq_from_irq(irq) != virq);
1415
1416                 /* Get a new binding from Xen. */
1417                 bind_virq.virq = virq;
1418                 bind_virq.vcpu = cpu;
1419                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1420                                                 &bind_virq) != 0)
1421                         BUG();
1422                 evtchn = bind_virq.port;
1423
1424                 /* Record the new mapping. */
1425                 xen_irq_info_virq_init(cpu, irq, evtchn, virq);
1426                 bind_evtchn_to_cpu(evtchn, cpu);
1427         }
1428 }
1429
1430 static void restore_cpu_ipis(unsigned int cpu)
1431 {
1432         struct evtchn_bind_ipi bind_ipi;
1433         int ipi, irq, evtchn;
1434
1435         for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1436                 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1437                         continue;
1438
1439                 BUG_ON(ipi_from_irq(irq) != ipi);
1440
1441                 /* Get a new binding from Xen. */
1442                 bind_ipi.vcpu = cpu;
1443                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1444                                                 &bind_ipi) != 0)
1445                         BUG();
1446                 evtchn = bind_ipi.port;
1447
1448                 /* Record the new mapping. */
1449                 xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
1450                 bind_evtchn_to_cpu(evtchn, cpu);
1451         }
1452 }
1453
1454 /* Clear an irq's pending state, in preparation for polling on it */
1455 void xen_clear_irq_pending(int irq)
1456 {
1457         int evtchn = evtchn_from_irq(irq);
1458
1459         if (VALID_EVTCHN(evtchn))
1460                 clear_evtchn(evtchn);
1461 }
1462 EXPORT_SYMBOL(xen_clear_irq_pending);
1463 void xen_set_irq_pending(int irq)
1464 {
1465         int evtchn = evtchn_from_irq(irq);
1466
1467         if (VALID_EVTCHN(evtchn))
1468                 set_evtchn(evtchn);
1469 }
1470
1471 bool xen_test_irq_pending(int irq)
1472 {
1473         int evtchn = evtchn_from_irq(irq);
1474         bool ret = false;
1475
1476         if (VALID_EVTCHN(evtchn))
1477                 ret = test_evtchn(evtchn);
1478
1479         return ret;
1480 }
1481
1482 /* Poll waiting for an irq to become pending with timeout.  In the usual case,
1483  * the irq will be disabled so it won't deliver an interrupt. */
1484 void xen_poll_irq_timeout(int irq, u64 timeout)
1485 {
1486         evtchn_port_t evtchn = evtchn_from_irq(irq);
1487
1488         if (VALID_EVTCHN(evtchn)) {
1489                 struct sched_poll poll;
1490
1491                 poll.nr_ports = 1;
1492                 poll.timeout = timeout;
1493                 set_xen_guest_handle(poll.ports, &evtchn);
1494
1495                 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1496                         BUG();
1497         }
1498 }
1499 EXPORT_SYMBOL(xen_poll_irq_timeout);
1500 /* Poll waiting for an irq to become pending.  In the usual case, the
1501  * irq will be disabled so it won't deliver an interrupt. */
1502 void xen_poll_irq(int irq)
1503 {
1504         xen_poll_irq_timeout(irq, 0 /* no timeout */);
1505 }
1506
1507 void xen_irq_resume(void)
1508 {
1509         unsigned int cpu, evtchn;
1510         struct irq_info *info;
1511
1512         init_evtchn_cpu_bindings();
1513
1514         /* New event-channel space is not 'live' yet. */
1515         for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1516                 mask_evtchn(evtchn);
1517
1518         /* No IRQ <-> event-channel mappings. */
1519         list_for_each_entry(info, &xen_irq_list_head, list)
1520                 info->evtchn = 0; /* zap event-channel binding */
1521
1522         for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1523                 evtchn_to_irq[evtchn] = -1;
1524
1525         for_each_possible_cpu(cpu) {
1526                 restore_cpu_virqs(cpu);
1527                 restore_cpu_ipis(cpu);
1528         }
1529
1530         restore_pirqs();
1531 }
1532
1533 static struct irq_chip xen_dynamic_chip __read_mostly = {
1534         .name                   = "xen-dyn",
1535
1536         .irq_disable            = disable_dynirq,
1537         .irq_mask               = disable_dynirq,
1538         .irq_unmask             = enable_dynirq,
1539
1540         .irq_eoi                = ack_dynirq,
1541         .irq_set_affinity       = set_affinity_irq,
1542         .irq_retrigger          = retrigger_dynirq,
1543 };
1544
1545 static struct irq_chip xen_pirq_chip __read_mostly = {
1546         .name                   = "xen-pirq",
1547
1548         .irq_startup            = startup_pirq,
1549         .irq_shutdown           = shutdown_pirq,
1550
1551         .irq_enable             = enable_pirq,
1552         .irq_unmask             = enable_pirq,
1553
1554         .irq_disable            = disable_pirq,
1555         .irq_mask               = disable_pirq,
1556
1557         .irq_ack                = ack_pirq,
1558
1559         .irq_set_affinity       = set_affinity_irq,
1560
1561         .irq_retrigger          = retrigger_dynirq,
1562 };
1563
1564 static struct irq_chip xen_percpu_chip __read_mostly = {
1565         .name                   = "xen-percpu",
1566
1567         .irq_disable            = disable_dynirq,
1568         .irq_mask               = disable_dynirq,
1569         .irq_unmask             = enable_dynirq,
1570
1571         .irq_ack                = ack_dynirq,
1572 };
1573
1574 int xen_set_callback_via(uint64_t via)
1575 {
1576         struct xen_hvm_param a;
1577         a.domid = DOMID_SELF;
1578         a.index = HVM_PARAM_CALLBACK_IRQ;
1579         a.value = via;
1580         return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1581 }
1582 EXPORT_SYMBOL_GPL(xen_set_callback_via);
1583
1584 #ifdef CONFIG_XEN_PVHVM
1585 /* Vector callbacks are better than PCI interrupts to receive event
1586  * channel notifications because we can receive vector callbacks on any
1587  * vcpu and we don't need PCI support or APIC interactions. */
1588 void xen_callback_vector(void)
1589 {
1590         int rc;
1591         uint64_t callback_via;
1592         if (xen_have_vector_callback) {
1593                 callback_via = HVM_CALLBACK_VECTOR(XEN_HVM_EVTCHN_CALLBACK);
1594                 rc = xen_set_callback_via(callback_via);
1595                 if (rc) {
1596                         printk(KERN_ERR "Request for Xen HVM callback vector"
1597                                         " failed.\n");
1598                         xen_have_vector_callback = 0;
1599                         return;
1600                 }
1601                 printk(KERN_INFO "Xen HVM callback vector for event delivery is "
1602                                 "enabled\n");
1603                 /* in the restore case the vector has already been allocated */
1604                 if (!test_bit(XEN_HVM_EVTCHN_CALLBACK, used_vectors))
1605                         alloc_intr_gate(XEN_HVM_EVTCHN_CALLBACK, xen_hvm_callback_vector);
1606         }
1607 }
1608 #else
1609 void xen_callback_vector(void) {}
1610 #endif
1611
1612 void __init xen_init_IRQ(void)
1613 {
1614         int i;
1615
1616         evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
1617                                     GFP_KERNEL);
1618         for (i = 0; i < NR_EVENT_CHANNELS; i++)
1619                 evtchn_to_irq[i] = -1;
1620
1621         init_evtchn_cpu_bindings();
1622
1623         /* No event channels are 'live' right now. */
1624         for (i = 0; i < NR_EVENT_CHANNELS; i++)
1625                 mask_evtchn(i);
1626
1627         if (xen_hvm_domain()) {
1628                 xen_callback_vector();
1629                 native_init_IRQ();
1630                 /* pci_xen_hvm_init must be called after native_init_IRQ so that
1631                  * __acpi_register_gsi can point at the right function */
1632                 pci_xen_hvm_init();
1633         } else {
1634                 irq_ctx_init(smp_processor_id());
1635                 if (xen_initial_domain())
1636                         xen_setup_pirqs();
1637         }
1638 }