1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Xen event channels
4 *
5 * Xen models interrupts with abstract event channels. Because each
6 * domain gets 1024 event channels, but NR_IRQ is not that large, we
7 * must dynamically map irqs<->event channels. The event channels
8 * interface with the rest of the kernel by defining a xen interrupt
9 * chip. When an event is received, it is mapped to an irq and sent
10 * through the normal interrupt processing path.
11 *
12 * There are four kinds of events which can be mapped to an event
13 * channel:
14 *
15 * 1. Inter-domain notifications. This includes all the virtual
16 * device events, since they're driven by front-ends in another domain
17 * (typically dom0).
18 * 2. VIRQs, typically used for timers. These are per-cpu events.
19 * 3. IPIs.
20 * 4. PIRQs - Hardware interrupts.
21 *
22 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
23 */
24
25#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
26
27#include <linux/linkage.h>
28#include <linux/interrupt.h>
29#include <linux/irq.h>
30#include <linux/moduleparam.h>
31#include <linux/string.h>
32#include <linux/memblock.h>
33#include <linux/slab.h>
34#include <linux/irqnr.h>
35#include <linux/pci.h>
36#include <linux/rcupdate.h>
37#include <linux/spinlock.h>
38#include <linux/cpuhotplug.h>
39#include <linux/atomic.h>
40#include <linux/ktime.h>
41
42#ifdef CONFIG_X86
43#include <asm/desc.h>
44#include <asm/ptrace.h>
45#include <asm/idtentry.h>
46#include <asm/irq.h>
47#include <asm/io_apic.h>
48#include <asm/i8259.h>
49#include <asm/xen/cpuid.h>
50#include <asm/xen/pci.h>
51#endif
52#include <asm/sync_bitops.h>
53#include <asm/xen/hypercall.h>
54#include <asm/xen/hypervisor.h>
55#include <xen/page.h>
56
57#include <xen/xen.h>
58#include <xen/hvm.h>
59#include <xen/xen-ops.h>
60#include <xen/events.h>
61#include <xen/interface/xen.h>
62#include <xen/interface/event_channel.h>
63#include <xen/interface/hvm/hvm_op.h>
64#include <xen/interface/hvm/params.h>
65#include <xen/interface/physdev.h>
66#include <xen/interface/sched.h>
67#include <xen/interface/vcpu.h>
68#include <xen/xenbus.h>
69#include <asm/hw_irq.h>
70
71#include "events_internal.h"
72
73#undef MODULE_PARAM_PREFIX
74#define MODULE_PARAM_PREFIX "xen."
75
76/* Interrupt types. */
77enum xen_irq_type {
78 IRQT_UNBOUND = 0,
79 IRQT_PIRQ,
80 IRQT_VIRQ,
81 IRQT_IPI,
82 IRQT_EVTCHN
83};
84
85/*
86 * Packed IRQ information:
87 * type - enum xen_irq_type
88 * event channel - irq->event channel mapping
89 * cpu - cpu this event channel is bound to
90 * index - type-specific information:
91 * PIRQ - vector, with MSB being "needs EIO", or physical IRQ of the HVM
92 * guest, or GSI (real passthrough IRQ) of the device.
93 * VIRQ - virq number
94 * IPI - IPI vector
95 * EVTCHN -
96 */
97struct irq_info {
98 struct list_head list;
99 struct list_head eoi_list;
100 struct rcu_work rwork;
101 short refcnt;
102 u8 spurious_cnt;
103 u8 is_accounted;
104 short type; /* type: IRQT_* */
105 u8 mask_reason; /* Why is event channel masked */
106#define EVT_MASK_REASON_EXPLICIT 0x01
107#define EVT_MASK_REASON_TEMPORARY 0x02
108#define EVT_MASK_REASON_EOI_PENDING 0x04
109 u8 is_active; /* Is event just being handled? */
110 unsigned irq;
111 evtchn_port_t evtchn; /* event channel */
112 unsigned short cpu; /* cpu bound */
113 unsigned short eoi_cpu; /* EOI must happen on this cpu-1 */
114 unsigned int irq_epoch; /* If eoi_cpu valid: irq_epoch of event */
115 u64 eoi_time; /* Time in jiffies when to EOI. */
116 raw_spinlock_t lock;
117 bool is_static; /* Is event channel static */
118
119 union {
120 unsigned short virq;
121 enum ipi_vector ipi;
122 struct {
123 unsigned short pirq;
124 unsigned short gsi;
125 unsigned char vector;
126 unsigned char flags;
127 uint16_t domid;
128 } pirq;
129 struct xenbus_device *interdomain;
130 } u;
131};
132
133#define PIRQ_NEEDS_EOI (1 << 0)
134#define PIRQ_SHAREABLE (1 << 1)
135#define PIRQ_MSI_GROUP (1 << 2)
136
137static uint __read_mostly event_loop_timeout = 2;
138module_param(event_loop_timeout, uint, 0644);
139
140static uint __read_mostly event_eoi_delay = 10;
141module_param(event_eoi_delay, uint, 0644);
142
143const struct evtchn_ops *evtchn_ops;
144
145/*
146 * This lock protects updates to the following mapping and reference-count
147 * arrays. The lock does not need to be acquired to read the mapping tables.
148 */
149static DEFINE_MUTEX(irq_mapping_update_lock);
150
151/*
152 * Lock hierarchy:
153 *
154 * irq_mapping_update_lock
155 * IRQ-desc lock
156 * percpu eoi_list_lock
157 * irq_info->lock
158 */
159
160static LIST_HEAD(xen_irq_list_head);
161
162/* IRQ <-> VIRQ mapping. */
163static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
164
165/* IRQ <-> IPI mapping */
166static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
167/* Cache for IPI event channels - needed for hot cpu unplug (avoid RCU usage). */
168static DEFINE_PER_CPU(evtchn_port_t [XEN_NR_IPIS], ipi_to_evtchn) = {[0 ... XEN_NR_IPIS-1] = 0};
169
170/* Event channel distribution data */
171static atomic_t channels_on_cpu[NR_CPUS];
172
173static int **evtchn_to_irq;
174#ifdef CONFIG_X86
175static unsigned long *pirq_eoi_map;
176#endif
177static bool (*pirq_needs_eoi)(struct irq_info *info);
178
179#define EVTCHN_ROW(e) (e / (PAGE_SIZE/sizeof(**evtchn_to_irq)))
180#define EVTCHN_COL(e) (e % (PAGE_SIZE/sizeof(**evtchn_to_irq)))
181#define EVTCHN_PER_ROW (PAGE_SIZE / sizeof(**evtchn_to_irq))
182
183/* Xen will never allocate port zero for any purpose. */
184#define VALID_EVTCHN(chn) ((chn) != 0)
185
186static struct irq_info *legacy_info_ptrs[NR_IRQS_LEGACY];
187
188static struct irq_chip xen_dynamic_chip;
189static struct irq_chip xen_lateeoi_chip;
190static struct irq_chip xen_percpu_chip;
191static struct irq_chip xen_pirq_chip;
192static void enable_dynirq(struct irq_data *data);
193
194static DEFINE_PER_CPU(unsigned int, irq_epoch);
195
196static void clear_evtchn_to_irq_row(int *evtchn_row)
197{
198 unsigned col;
199
200 for (col = 0; col < EVTCHN_PER_ROW; col++)
201 WRITE_ONCE(evtchn_row[col], -1);
202}
203
204static void clear_evtchn_to_irq_all(void)
205{
206 unsigned row;
207
208 for (row = 0; row < EVTCHN_ROW(xen_evtchn_max_channels()); row++) {
209 if (evtchn_to_irq[row] == NULL)
210 continue;
211 clear_evtchn_to_irq_row(evtchn_row: evtchn_to_irq[row]);
212 }
213}
214
215static int set_evtchn_to_irq(evtchn_port_t evtchn, unsigned int irq)
216{
217 unsigned row;
218 unsigned col;
219 int *evtchn_row;
220
221 if (evtchn >= xen_evtchn_max_channels())
222 return -EINVAL;
223
224 row = EVTCHN_ROW(evtchn);
225 col = EVTCHN_COL(evtchn);
226
227 if (evtchn_to_irq[row] == NULL) {
228 /* Unallocated irq entries return -1 anyway */
229 if (irq == -1)
230 return 0;
231
232 evtchn_row = (int *) __get_free_pages(GFP_KERNEL, order: 0);
233 if (evtchn_row == NULL)
234 return -ENOMEM;
235
236 clear_evtchn_to_irq_row(evtchn_row);
237
238 /*
239 * We've prepared an empty row for the mapping. If a different
240 * thread was faster inserting it, we can drop ours.
241 */
242 if (cmpxchg(&evtchn_to_irq[row], NULL, evtchn_row) != NULL)
243 free_page((unsigned long) evtchn_row);
244 }
245
246 WRITE_ONCE(evtchn_to_irq[row][col], irq);
247 return 0;
248}
249
250/* Get info for IRQ */
251static struct irq_info *info_for_irq(unsigned irq)
252{
253 if (irq < nr_legacy_irqs())
254 return legacy_info_ptrs[irq];
255 else
256 return irq_get_chip_data(irq);
257}
258
259static void set_info_for_irq(unsigned int irq, struct irq_info *info)
260{
261 if (irq < nr_legacy_irqs())
262 legacy_info_ptrs[irq] = info;
263 else
264 irq_set_chip_data(irq, data: info);
265}
266
267static struct irq_info *evtchn_to_info(evtchn_port_t evtchn)
268{
269 int irq;
270
271 if (evtchn >= xen_evtchn_max_channels())
272 return NULL;
273 if (evtchn_to_irq[EVTCHN_ROW(evtchn)] == NULL)
274 return NULL;
275 irq = READ_ONCE(evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)]);
276
277 return (irq < 0) ? NULL : info_for_irq(irq);
278}
279
280/* Per CPU channel accounting */
281static void channels_on_cpu_dec(struct irq_info *info)
282{
283 if (!info->is_accounted)
284 return;
285
286 info->is_accounted = 0;
287
288 if (WARN_ON_ONCE(info->cpu >= nr_cpu_ids))
289 return;
290
291 WARN_ON_ONCE(!atomic_add_unless(&channels_on_cpu[info->cpu], -1 , 0));
292}
293
294static void channels_on_cpu_inc(struct irq_info *info)
295{
296 if (WARN_ON_ONCE(info->cpu >= nr_cpu_ids))
297 return;
298
299 if (WARN_ON_ONCE(!atomic_add_unless(&channels_on_cpu[info->cpu], 1,
300 INT_MAX)))
301 return;
302
303 info->is_accounted = 1;
304}
305
306static void xen_irq_free_desc(unsigned int irq)
307{
308 /* Legacy IRQ descriptors are managed by the arch. */
309 if (irq >= nr_legacy_irqs())
310 irq_free_desc(irq);
311}
312
313static void delayed_free_irq(struct work_struct *work)
314{
315 struct irq_info *info = container_of(to_rcu_work(work), struct irq_info,
316 rwork);
317 unsigned int irq = info->irq;
318
319 /* Remove the info pointer only now, with no potential users left. */
320 set_info_for_irq(irq, NULL);
321
322 kfree(objp: info);
323
324 xen_irq_free_desc(irq);
325}
326
327/* Constructors for packed IRQ information. */
328static int xen_irq_info_common_setup(struct irq_info *info,
329 enum xen_irq_type type,
330 evtchn_port_t evtchn,
331 unsigned short cpu)
332{
333 int ret;
334
335 BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
336
337 info->type = type;
338 info->evtchn = evtchn;
339 info->cpu = cpu;
340 info->mask_reason = EVT_MASK_REASON_EXPLICIT;
341 raw_spin_lock_init(&info->lock);
342
343 ret = set_evtchn_to_irq(evtchn, irq: info->irq);
344 if (ret < 0)
345 return ret;
346
347 irq_clear_status_flags(irq: info->irq, clr: IRQ_NOREQUEST | IRQ_NOAUTOEN);
348
349 return xen_evtchn_port_setup(evtchn);
350}
351
352static int xen_irq_info_evtchn_setup(struct irq_info *info,
353 evtchn_port_t evtchn,
354 struct xenbus_device *dev)
355{
356 int ret;
357
358 ret = xen_irq_info_common_setup(info, type: IRQT_EVTCHN, evtchn, cpu: 0);
359 info->u.interdomain = dev;
360 if (dev)
361 atomic_inc(v: &dev->event_channels);
362
363 return ret;
364}
365
366static int xen_irq_info_ipi_setup(struct irq_info *info, unsigned int cpu,
367 evtchn_port_t evtchn, enum ipi_vector ipi)
368{
369 info->u.ipi = ipi;
370
371 per_cpu(ipi_to_irq, cpu)[ipi] = info->irq;
372 per_cpu(ipi_to_evtchn, cpu)[ipi] = evtchn;
373
374 return xen_irq_info_common_setup(info, type: IRQT_IPI, evtchn, cpu: 0);
375}
376
377static int xen_irq_info_virq_setup(struct irq_info *info, unsigned int cpu,
378 evtchn_port_t evtchn, unsigned int virq)
379{
380 info->u.virq = virq;
381
382 per_cpu(virq_to_irq, cpu)[virq] = info->irq;
383
384 return xen_irq_info_common_setup(info, type: IRQT_VIRQ, evtchn, cpu: 0);
385}
386
387static int xen_irq_info_pirq_setup(struct irq_info *info, evtchn_port_t evtchn,
388 unsigned int pirq, unsigned int gsi,
389 uint16_t domid, unsigned char flags)
390{
391 info->u.pirq.pirq = pirq;
392 info->u.pirq.gsi = gsi;
393 info->u.pirq.domid = domid;
394 info->u.pirq.flags = flags;
395
396 return xen_irq_info_common_setup(info, type: IRQT_PIRQ, evtchn, cpu: 0);
397}
398
399static void xen_irq_info_cleanup(struct irq_info *info)
400{
401 set_evtchn_to_irq(evtchn: info->evtchn, irq: -1);
402 xen_evtchn_port_remove(evtchn: info->evtchn, cpu: info->cpu);
403 info->evtchn = 0;
404 channels_on_cpu_dec(info);
405}
406
407/*
408 * Accessors for packed IRQ information.
409 */
410static evtchn_port_t evtchn_from_irq(unsigned int irq)
411{
412 const struct irq_info *info = NULL;
413
414 if (likely(irq < nr_irqs))
415 info = info_for_irq(irq);
416 if (!info)
417 return 0;
418
419 return info->evtchn;
420}
421
422unsigned int irq_from_evtchn(evtchn_port_t evtchn)
423{
424 struct irq_info *info = evtchn_to_info(evtchn);
425
426 return info ? info->irq : -1;
427}
428EXPORT_SYMBOL_GPL(irq_from_evtchn);
429
430int irq_evtchn_from_virq(unsigned int cpu, unsigned int virq,
431 evtchn_port_t *evtchn)
432{
433 int irq = per_cpu(virq_to_irq, cpu)[virq];
434
435 *evtchn = evtchn_from_irq(irq);
436
437 return irq;
438}
439
440static enum ipi_vector ipi_from_irq(struct irq_info *info)
441{
442 BUG_ON(info == NULL);
443 BUG_ON(info->type != IRQT_IPI);
444
445 return info->u.ipi;
446}
447
448static unsigned int virq_from_irq(struct irq_info *info)
449{
450 BUG_ON(info == NULL);
451 BUG_ON(info->type != IRQT_VIRQ);
452
453 return info->u.virq;
454}
455
456static unsigned int pirq_from_irq(struct irq_info *info)
457{
458 BUG_ON(info == NULL);
459 BUG_ON(info->type != IRQT_PIRQ);
460
461 return info->u.pirq.pirq;
462}
463
464unsigned int cpu_from_evtchn(evtchn_port_t evtchn)
465{
466 struct irq_info *info = evtchn_to_info(evtchn);
467
468 return info ? info->cpu : 0;
469}
470
471static void do_mask(struct irq_info *info, u8 reason)
472{
473 unsigned long flags;
474
475 raw_spin_lock_irqsave(&info->lock, flags);
476
477 if (!info->mask_reason)
478 mask_evtchn(port: info->evtchn);
479
480 info->mask_reason |= reason;
481
482 raw_spin_unlock_irqrestore(&info->lock, flags);
483}
484
485static void do_unmask(struct irq_info *info, u8 reason)
486{
487 unsigned long flags;
488
489 raw_spin_lock_irqsave(&info->lock, flags);
490
491 info->mask_reason &= ~reason;
492
493 if (!info->mask_reason)
494 unmask_evtchn(port: info->evtchn);
495
496 raw_spin_unlock_irqrestore(&info->lock, flags);
497}
498
499#ifdef CONFIG_X86
500static bool pirq_check_eoi_map(struct irq_info *info)
501{
502 return test_bit(pirq_from_irq(info), pirq_eoi_map);
503}
504#endif
505
506static bool pirq_needs_eoi_flag(struct irq_info *info)
507{
508 BUG_ON(info->type != IRQT_PIRQ);
509
510 return info->u.pirq.flags & PIRQ_NEEDS_EOI;
511}
512
513static void bind_evtchn_to_cpu(struct irq_info *info, unsigned int cpu,
514 bool force_affinity)
515{
516 if (IS_ENABLED(CONFIG_SMP) && force_affinity) {
517 struct irq_data *data = irq_get_irq_data(irq: info->irq);
518
519 irq_data_update_affinity(d: data, cpumask_of(cpu));
520 irq_data_update_effective_affinity(d: data, cpumask_of(cpu));
521 }
522
523 xen_evtchn_port_bind_to_cpu(evtchn: info->evtchn, cpu, old_cpu: info->cpu);
524
525 channels_on_cpu_dec(info);
526 info->cpu = cpu;
527 channels_on_cpu_inc(info);
528}
529
530/**
531 * notify_remote_via_irq - send event to remote end of event channel via irq
532 * @irq: irq of event channel to send event to
533 *
534 * Unlike notify_remote_via_evtchn(), this is safe to use across
535 * save/restore. Notifications on a broken connection are silently
536 * dropped.
537 */
538void notify_remote_via_irq(int irq)
539{
540 evtchn_port_t evtchn = evtchn_from_irq(irq);
541
542 if (VALID_EVTCHN(evtchn))
543 notify_remote_via_evtchn(port: evtchn);
544}
545EXPORT_SYMBOL_GPL(notify_remote_via_irq);
546
547struct lateeoi_work {
548 struct delayed_work delayed;
549 spinlock_t eoi_list_lock;
550 struct list_head eoi_list;
551};
552
553static DEFINE_PER_CPU(struct lateeoi_work, lateeoi);
554
555static void lateeoi_list_del(struct irq_info *info)
556{
557 struct lateeoi_work *eoi = &per_cpu(lateeoi, info->eoi_cpu);
558 unsigned long flags;
559
560 spin_lock_irqsave(&eoi->eoi_list_lock, flags);
561 list_del_init(entry: &info->eoi_list);
562 spin_unlock_irqrestore(lock: &eoi->eoi_list_lock, flags);
563}
564
565static void lateeoi_list_add(struct irq_info *info)
566{
567 struct lateeoi_work *eoi = &per_cpu(lateeoi, info->eoi_cpu);
568 struct irq_info *elem;
569 u64 now = get_jiffies_64();
570 unsigned long delay;
571 unsigned long flags;
572
573 if (now < info->eoi_time)
574 delay = info->eoi_time - now;
575 else
576 delay = 1;
577
578 spin_lock_irqsave(&eoi->eoi_list_lock, flags);
579
580 elem = list_first_entry_or_null(&eoi->eoi_list, struct irq_info,
581 eoi_list);
582 if (!elem || info->eoi_time < elem->eoi_time) {
583 list_add(new: &info->eoi_list, head: &eoi->eoi_list);
584 mod_delayed_work_on(cpu: info->eoi_cpu, wq: system_wq,
585 dwork: &eoi->delayed, delay);
586 } else {
587 list_for_each_entry_reverse(elem, &eoi->eoi_list, eoi_list) {
588 if (elem->eoi_time <= info->eoi_time)
589 break;
590 }
591 list_add(new: &info->eoi_list, head: &elem->eoi_list);
592 }
593
594 spin_unlock_irqrestore(lock: &eoi->eoi_list_lock, flags);
595}
596
597static void xen_irq_lateeoi_locked(struct irq_info *info, bool spurious)
598{
599 evtchn_port_t evtchn;
600 unsigned int cpu;
601 unsigned int delay = 0;
602
603 evtchn = info->evtchn;
604 if (!VALID_EVTCHN(evtchn) || !list_empty(head: &info->eoi_list))
605 return;
606
607 if (spurious) {
608 struct xenbus_device *dev = info->u.interdomain;
609 unsigned int threshold = 1;
610
611 if (dev && dev->spurious_threshold)
612 threshold = dev->spurious_threshold;
613
614 if ((1 << info->spurious_cnt) < (HZ << 2)) {
615 if (info->spurious_cnt != 0xFF)
616 info->spurious_cnt++;
617 }
618 if (info->spurious_cnt > threshold) {
619 delay = 1 << (info->spurious_cnt - 1 - threshold);
620 if (delay > HZ)
621 delay = HZ;
622 if (!info->eoi_time)
623 info->eoi_cpu = smp_processor_id();
624 info->eoi_time = get_jiffies_64() + delay;
625 if (dev)
626 atomic_add(i: delay, v: &dev->jiffies_eoi_delayed);
627 }
628 if (dev)
629 atomic_inc(v: &dev->spurious_events);
630 } else {
631 info->spurious_cnt = 0;
632 }
633
634 cpu = info->eoi_cpu;
635 if (info->eoi_time &&
636 (info->irq_epoch == per_cpu(irq_epoch, cpu) || delay)) {
637 lateeoi_list_add(info);
638 return;
639 }
640
641 info->eoi_time = 0;
642
643 /* is_active hasn't been reset yet, do it now. */
644 smp_store_release(&info->is_active, 0);
645 do_unmask(info, EVT_MASK_REASON_EOI_PENDING);
646}
647
648static void xen_irq_lateeoi_worker(struct work_struct *work)
649{
650 struct lateeoi_work *eoi;
651 struct irq_info *info;
652 u64 now = get_jiffies_64();
653 unsigned long flags;
654
655 eoi = container_of(to_delayed_work(work), struct lateeoi_work, delayed);
656
657 rcu_read_lock();
658
659 while (true) {
660 spin_lock_irqsave(&eoi->eoi_list_lock, flags);
661
662 info = list_first_entry_or_null(&eoi->eoi_list, struct irq_info,
663 eoi_list);
664
665 if (info == NULL)
666 break;
667
668 if (now < info->eoi_time) {
669 mod_delayed_work_on(cpu: info->eoi_cpu, wq: system_wq,
670 dwork: &eoi->delayed,
671 delay: info->eoi_time - now);
672 break;
673 }
674
675 list_del_init(entry: &info->eoi_list);
676
677 spin_unlock_irqrestore(lock: &eoi->eoi_list_lock, flags);
678
679 info->eoi_time = 0;
680
681 xen_irq_lateeoi_locked(info, spurious: false);
682 }
683
684 spin_unlock_irqrestore(lock: &eoi->eoi_list_lock, flags);
685
686 rcu_read_unlock();
687}
688
689static void xen_cpu_init_eoi(unsigned int cpu)
690{
691 struct lateeoi_work *eoi = &per_cpu(lateeoi, cpu);
692
693 INIT_DELAYED_WORK(&eoi->delayed, xen_irq_lateeoi_worker);
694 spin_lock_init(&eoi->eoi_list_lock);
695 INIT_LIST_HEAD(list: &eoi->eoi_list);
696}
697
698void xen_irq_lateeoi(unsigned int irq, unsigned int eoi_flags)
699{
700 struct irq_info *info;
701
702 rcu_read_lock();
703
704 info = info_for_irq(irq);
705
706 if (info)
707 xen_irq_lateeoi_locked(info, spurious: eoi_flags & XEN_EOI_FLAG_SPURIOUS);
708
709 rcu_read_unlock();
710}
711EXPORT_SYMBOL_GPL(xen_irq_lateeoi);
712
713static struct irq_info *xen_irq_init(unsigned int irq)
714{
715 struct irq_info *info;
716
717 info = kzalloc(size: sizeof(*info), GFP_KERNEL);
718 if (info) {
719 info->irq = irq;
720 info->type = IRQT_UNBOUND;
721 info->refcnt = -1;
722 INIT_RCU_WORK(&info->rwork, delayed_free_irq);
723
724 set_info_for_irq(irq, info);
725 /*
726 * Interrupt affinity setting can be immediate. No point
727 * in delaying it until an interrupt is handled.
728 */
729 irq_set_status_flags(irq, set: IRQ_MOVE_PCNTXT);
730
731 INIT_LIST_HEAD(list: &info->eoi_list);
732 list_add_tail(new: &info->list, head: &xen_irq_list_head);
733 }
734
735 return info;
736}
737
738static struct irq_info *xen_allocate_irq_dynamic(void)
739{
740 int irq = irq_alloc_desc_from(0, -1);
741 struct irq_info *info = NULL;
742
743 if (irq >= 0) {
744 info = xen_irq_init(irq);
745 if (!info)
746 xen_irq_free_desc(irq);
747 }
748
749 return info;
750}
751
752static struct irq_info *xen_allocate_irq_gsi(unsigned int gsi)
753{
754 int irq;
755 struct irq_info *info;
756
757 /*
758 * A PV guest has no concept of a GSI (since it has no ACPI
759 * nor access to/knowledge of the physical APICs). Therefore
760 * all IRQs are dynamically allocated from the entire IRQ
761 * space.
762 */
763 if (xen_pv_domain() && !xen_initial_domain())
764 return xen_allocate_irq_dynamic();
765
766 /* Legacy IRQ descriptors are already allocated by the arch. */
767 if (gsi < nr_legacy_irqs())
768 irq = gsi;
769 else
770 irq = irq_alloc_desc_at(gsi, -1);
771
772 info = xen_irq_init(irq);
773 if (!info)
774 xen_irq_free_desc(irq);
775
776 return info;
777}
778
779static void xen_free_irq(struct irq_info *info)
780{
781 if (WARN_ON(!info))
782 return;
783
784 if (!list_empty(head: &info->eoi_list))
785 lateeoi_list_del(info);
786
787 list_del(entry: &info->list);
788
789 WARN_ON(info->refcnt > 0);
790
791 queue_rcu_work(wq: system_wq, rwork: &info->rwork);
792}
793
794/* Not called for lateeoi events. */
795static void event_handler_exit(struct irq_info *info)
796{
797 smp_store_release(&info->is_active, 0);
798 clear_evtchn(port: info->evtchn);
799}
800
801static void pirq_query_unmask(struct irq_info *info)
802{
803 struct physdev_irq_status_query irq_status;
804
805 irq_status.irq = pirq_from_irq(info);
806 if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, arg: &irq_status))
807 irq_status.flags = 0;
808
809 info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
810 if (irq_status.flags & XENIRQSTAT_needs_eoi)
811 info->u.pirq.flags |= PIRQ_NEEDS_EOI;
812}
813
814static void do_eoi_pirq(struct irq_info *info)
815{
816 struct physdev_eoi eoi = { .irq = pirq_from_irq(info) };
817 int rc = 0;
818
819 if (!VALID_EVTCHN(info->evtchn))
820 return;
821
822 event_handler_exit(info);
823
824 if (pirq_needs_eoi(info)) {
825 rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, arg: &eoi);
826 WARN_ON(rc);
827 }
828}
829
830static void eoi_pirq(struct irq_data *data)
831{
832 struct irq_info *info = info_for_irq(irq: data->irq);
833
834 do_eoi_pirq(info);
835}
836
837static void do_disable_dynirq(struct irq_info *info)
838{
839 if (VALID_EVTCHN(info->evtchn))
840 do_mask(info, EVT_MASK_REASON_EXPLICIT);
841}
842
843static void disable_dynirq(struct irq_data *data)
844{
845 struct irq_info *info = info_for_irq(irq: data->irq);
846
847 if (info)
848 do_disable_dynirq(info);
849}
850
851static void mask_ack_pirq(struct irq_data *data)
852{
853 struct irq_info *info = info_for_irq(irq: data->irq);
854
855 if (info) {
856 do_disable_dynirq(info);
857 do_eoi_pirq(info);
858 }
859}
860
861static unsigned int __startup_pirq(struct irq_info *info)
862{
863 struct evtchn_bind_pirq bind_pirq;
864 evtchn_port_t evtchn = info->evtchn;
865 int rc;
866
867 if (VALID_EVTCHN(evtchn))
868 goto out;
869
870 bind_pirq.pirq = pirq_from_irq(info);
871 /* NB. We are happy to share unless we are probing. */
872 bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
873 BIND_PIRQ__WILL_SHARE : 0;
874 rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, arg: &bind_pirq);
875 if (rc != 0) {
876 pr_warn("Failed to obtain physical IRQ %d\n", info->irq);
877 return 0;
878 }
879 evtchn = bind_pirq.port;
880
881 pirq_query_unmask(info);
882
883 rc = set_evtchn_to_irq(evtchn, irq: info->irq);
884 if (rc)
885 goto err;
886
887 info->evtchn = evtchn;
888 bind_evtchn_to_cpu(info, cpu: 0, force_affinity: false);
889
890 rc = xen_evtchn_port_setup(evtchn);
891 if (rc)
892 goto err;
893
894out:
895 do_unmask(info, EVT_MASK_REASON_EXPLICIT);
896
897 do_eoi_pirq(info);
898
899 return 0;
900
901err:
902 pr_err("irq%d: Failed to set port to irq mapping (%d)\n", info->irq,
903 rc);
904 xen_evtchn_close(port: evtchn);
905 return 0;
906}
907
908static unsigned int startup_pirq(struct irq_data *data)
909{
910 struct irq_info *info = info_for_irq(irq: data->irq);
911
912 return __startup_pirq(info);
913}
914
915static void shutdown_pirq(struct irq_data *data)
916{
917 struct irq_info *info = info_for_irq(irq: data->irq);
918 evtchn_port_t evtchn = info->evtchn;
919
920 BUG_ON(info->type != IRQT_PIRQ);
921
922 if (!VALID_EVTCHN(evtchn))
923 return;
924
925 do_mask(info, EVT_MASK_REASON_EXPLICIT);
926 xen_irq_info_cleanup(info);
927 xen_evtchn_close(port: evtchn);
928}
929
930static void enable_pirq(struct irq_data *data)
931{
932 enable_dynirq(data);
933}
934
935static void disable_pirq(struct irq_data *data)
936{
937 disable_dynirq(data);
938}
939
940int xen_irq_from_gsi(unsigned gsi)
941{
942 struct irq_info *info;
943
944 list_for_each_entry(info, &xen_irq_list_head, list) {
945 if (info->type != IRQT_PIRQ)
946 continue;
947
948 if (info->u.pirq.gsi == gsi)
949 return info->irq;
950 }
951
952 return -1;
953}
954EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
955
956static void __unbind_from_irq(struct irq_info *info, unsigned int irq)
957{
958 evtchn_port_t evtchn;
959 bool close_evtchn = false;
960
961 if (!info) {
962 xen_irq_free_desc(irq);
963 return;
964 }
965
966 if (info->refcnt > 0) {
967 info->refcnt--;
968 if (info->refcnt != 0)
969 return;
970 }
971
972 evtchn = info->evtchn;
973
974 if (VALID_EVTCHN(evtchn)) {
975 unsigned int cpu = info->cpu;
976 struct xenbus_device *dev;
977
978 if (!info->is_static)
979 close_evtchn = true;
980
981 switch (info->type) {
982 case IRQT_VIRQ:
983 per_cpu(virq_to_irq, cpu)[virq_from_irq(info)] = -1;
984 break;
985 case IRQT_IPI:
986 per_cpu(ipi_to_irq, cpu)[ipi_from_irq(info)] = -1;
987 per_cpu(ipi_to_evtchn, cpu)[ipi_from_irq(info)] = 0;
988 break;
989 case IRQT_EVTCHN:
990 dev = info->u.interdomain;
991 if (dev)
992 atomic_dec(v: &dev->event_channels);
993 break;
994 default:
995 break;
996 }
997
998 xen_irq_info_cleanup(info);
999
1000 if (close_evtchn)
1001 xen_evtchn_close(port: evtchn);
1002 }
1003
1004 xen_free_irq(info);
1005}
1006
1007/*
1008 * Do not make any assumptions regarding the relationship between the
1009 * IRQ number returned here and the Xen pirq argument.
1010 *
1011 * Note: We don't assign an event channel until the irq actually started
1012 * up. Return an existing irq if we've already got one for the gsi.
1013 *
1014 * Shareable implies level triggered, not shareable implies edge
1015 * triggered here.
1016 */
1017int xen_bind_pirq_gsi_to_irq(unsigned gsi,
1018 unsigned pirq, int shareable, char *name)
1019{
1020 struct irq_info *info;
1021 struct physdev_irq irq_op;
1022 int ret;
1023
1024 mutex_lock(&irq_mapping_update_lock);
1025
1026 ret = xen_irq_from_gsi(gsi);
1027 if (ret != -1) {
1028 pr_info("%s: returning irq %d for gsi %u\n",
1029 __func__, ret, gsi);
1030 goto out;
1031 }
1032
1033 info = xen_allocate_irq_gsi(gsi);
1034 if (!info)
1035 goto out;
1036
1037 irq_op.irq = info->irq;
1038 irq_op.vector = 0;
1039
1040 /* Only the privileged domain can do this. For non-priv, the pcifront
1041 * driver provides a PCI bus that does the call to do exactly
1042 * this in the priv domain. */
1043 if (xen_initial_domain() &&
1044 HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, arg: &irq_op)) {
1045 xen_free_irq(info);
1046 ret = -ENOSPC;
1047 goto out;
1048 }
1049
1050 ret = xen_irq_info_pirq_setup(info, evtchn: 0, pirq, gsi, DOMID_SELF,
1051 flags: shareable ? PIRQ_SHAREABLE : 0);
1052 if (ret < 0) {
1053 __unbind_from_irq(info, irq: info->irq);
1054 goto out;
1055 }
1056
1057 pirq_query_unmask(info);
1058 /* We try to use the handler with the appropriate semantic for the
1059 * type of interrupt: if the interrupt is an edge triggered
1060 * interrupt we use handle_edge_irq.
1061 *
1062 * On the other hand if the interrupt is level triggered we use
1063 * handle_fasteoi_irq like the native code does for this kind of
1064 * interrupts.
1065 *
1066 * Depending on the Xen version, pirq_needs_eoi might return true
1067 * not only for level triggered interrupts but for edge triggered
1068 * interrupts too. In any case Xen always honors the eoi mechanism,
1069 * not injecting any more pirqs of the same kind if the first one
1070 * hasn't received an eoi yet. Therefore using the fasteoi handler
1071 * is the right choice either way.
1072 */
1073 if (shareable)
1074 irq_set_chip_and_handler_name(irq: info->irq, chip: &xen_pirq_chip,
1075 handle: handle_fasteoi_irq, name);
1076 else
1077 irq_set_chip_and_handler_name(irq: info->irq, chip: &xen_pirq_chip,
1078 handle: handle_edge_irq, name);
1079
1080 ret = info->irq;
1081
1082out:
1083 mutex_unlock(lock: &irq_mapping_update_lock);
1084
1085 return ret;
1086}
1087
1088#ifdef CONFIG_PCI_MSI
1089int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
1090{
1091 int rc;
1092 struct physdev_get_free_pirq op_get_free_pirq;
1093
1094 op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
1095 rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, arg: &op_get_free_pirq);
1096
1097 WARN_ONCE(rc == -ENOSYS,
1098 "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
1099
1100 return rc ? -1 : op_get_free_pirq.pirq;
1101}
1102
1103int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
1104 int pirq, int nvec, const char *name, domid_t domid)
1105{
1106 int i, irq, ret;
1107 struct irq_info *info;
1108
1109 mutex_lock(&irq_mapping_update_lock);
1110
1111 irq = irq_alloc_descs(-1, 0, nvec, -1);
1112 if (irq < 0)
1113 goto out;
1114
1115 for (i = 0; i < nvec; i++) {
1116 info = xen_irq_init(irq: irq + i);
1117 if (!info) {
1118 ret = -ENOMEM;
1119 goto error_irq;
1120 }
1121
1122 irq_set_chip_and_handler_name(irq: irq + i, chip: &xen_pirq_chip, handle: handle_edge_irq, name);
1123
1124 ret = xen_irq_info_pirq_setup(info, evtchn: 0, pirq: pirq + i, gsi: 0, domid,
1125 flags: i == 0 ? 0 : PIRQ_MSI_GROUP);
1126 if (ret < 0)
1127 goto error_irq;
1128 }
1129
1130 ret = irq_set_msi_desc(irq, entry: msidesc);
1131 if (ret < 0)
1132 goto error_irq;
1133out:
1134 mutex_unlock(lock: &irq_mapping_update_lock);
1135 return irq;
1136
1137error_irq:
1138 while (nvec--) {
1139 info = info_for_irq(irq: irq + nvec);
1140 __unbind_from_irq(info, irq: irq + nvec);
1141 }
1142 mutex_unlock(lock: &irq_mapping_update_lock);
1143 return ret;
1144}
1145#endif
1146
1147int xen_destroy_irq(int irq)
1148{
1149 struct physdev_unmap_pirq unmap_irq;
1150 struct irq_info *info = info_for_irq(irq);
1151 int rc = -ENOENT;
1152
1153 mutex_lock(&irq_mapping_update_lock);
1154
1155 /*
1156 * If trying to remove a vector in a MSI group different
1157 * than the first one skip the PIRQ unmap unless this vector
1158 * is the first one in the group.
1159 */
1160 if (xen_initial_domain() && !(info->u.pirq.flags & PIRQ_MSI_GROUP)) {
1161 unmap_irq.pirq = info->u.pirq.pirq;
1162 unmap_irq.domid = info->u.pirq.domid;
1163 rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, arg: &unmap_irq);
1164 /* If another domain quits without making the pci_disable_msix
1165 * call, the Xen hypervisor takes care of freeing the PIRQs
1166 * (free_domain_pirqs).
1167 */
1168 if ((rc == -ESRCH && info->u.pirq.domid != DOMID_SELF))
1169 pr_info("domain %d does not have %d anymore\n",
1170 info->u.pirq.domid, info->u.pirq.pirq);
1171 else if (rc) {
1172 pr_warn("unmap irq failed %d\n", rc);
1173 goto out;
1174 }
1175 }
1176
1177 xen_free_irq(info);
1178
1179out:
1180 mutex_unlock(lock: &irq_mapping_update_lock);
1181 return rc;
1182}
1183
1184int xen_pirq_from_irq(unsigned irq)
1185{
1186 struct irq_info *info = info_for_irq(irq);
1187
1188 return pirq_from_irq(info);
1189}
1190EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
1191
1192static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip,
1193 struct xenbus_device *dev, bool shared)
1194{
1195 int ret = -ENOMEM;
1196 struct irq_info *info;
1197
1198 if (evtchn >= xen_evtchn_max_channels())
1199 return -ENOMEM;
1200
1201 mutex_lock(&irq_mapping_update_lock);
1202
1203 info = evtchn_to_info(evtchn);
1204
1205 if (!info) {
1206 info = xen_allocate_irq_dynamic();
1207 if (!info)
1208 goto out;
1209
1210 irq_set_chip_and_handler_name(irq: info->irq, chip,
1211 handle: handle_edge_irq, name: "event");
1212
1213 ret = xen_irq_info_evtchn_setup(info, evtchn, dev);
1214 if (ret < 0) {
1215 __unbind_from_irq(info, irq: info->irq);
1216 goto out;
1217 }
1218 /*
1219 * New interdomain events are initially bound to vCPU0 This
1220 * is required to setup the event channel in the first
1221 * place and also important for UP guests because the
1222 * affinity setting is not invoked on them so nothing would
1223 * bind the channel.
1224 */
1225 bind_evtchn_to_cpu(info, cpu: 0, force_affinity: false);
1226 } else if (!WARN_ON(info->type != IRQT_EVTCHN)) {
1227 if (shared && !WARN_ON(info->refcnt < 0))
1228 info->refcnt++;
1229 }
1230
1231 ret = info->irq;
1232
1233out:
1234 mutex_unlock(lock: &irq_mapping_update_lock);
1235
1236 return ret;
1237}
1238
1239int bind_evtchn_to_irq(evtchn_port_t evtchn)
1240{
1241 return bind_evtchn_to_irq_chip(evtchn, chip: &xen_dynamic_chip, NULL, shared: false);
1242}
1243EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
1244
1245int bind_evtchn_to_irq_lateeoi(evtchn_port_t evtchn)
1246{
1247 return bind_evtchn_to_irq_chip(evtchn, chip: &xen_lateeoi_chip, NULL, shared: false);
1248}
1249EXPORT_SYMBOL_GPL(bind_evtchn_to_irq_lateeoi);
1250
1251static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
1252{
1253 struct evtchn_bind_ipi bind_ipi;
1254 evtchn_port_t evtchn;
1255 struct irq_info *info;
1256 int ret;
1257
1258 mutex_lock(&irq_mapping_update_lock);
1259
1260 ret = per_cpu(ipi_to_irq, cpu)[ipi];
1261
1262 if (ret == -1) {
1263 info = xen_allocate_irq_dynamic();
1264 if (!info)
1265 goto out;
1266
1267 irq_set_chip_and_handler_name(irq: info->irq, chip: &xen_percpu_chip,
1268 handle: handle_percpu_irq, name: "ipi");
1269
1270 bind_ipi.vcpu = xen_vcpu_nr(cpu);
1271 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1272 arg: &bind_ipi) != 0)
1273 BUG();
1274 evtchn = bind_ipi.port;
1275
1276 ret = xen_irq_info_ipi_setup(info, cpu, evtchn, ipi);
1277 if (ret < 0) {
1278 __unbind_from_irq(info, irq: info->irq);
1279 goto out;
1280 }
1281 /*
1282 * Force the affinity mask to the target CPU so proc shows
1283 * the correct target.
1284 */
1285 bind_evtchn_to_cpu(info, cpu, force_affinity: true);
1286 ret = info->irq;
1287 } else {
1288 info = info_for_irq(irq: ret);
1289 WARN_ON(info == NULL || info->type != IRQT_IPI);
1290 }
1291
1292 out:
1293 mutex_unlock(lock: &irq_mapping_update_lock);
1294 return ret;
1295}
1296
1297static int bind_interdomain_evtchn_to_irq_chip(struct xenbus_device *dev,
1298 evtchn_port_t remote_port,
1299 struct irq_chip *chip,
1300 bool shared)
1301{
1302 struct evtchn_bind_interdomain bind_interdomain;
1303 int err;
1304
1305 bind_interdomain.remote_dom = dev->otherend_id;
1306 bind_interdomain.remote_port = remote_port;
1307
1308 err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
1309 arg: &bind_interdomain);
1310
1311 return err ? : bind_evtchn_to_irq_chip(evtchn: bind_interdomain.local_port,
1312 chip, dev, shared);
1313}
1314
1315int bind_interdomain_evtchn_to_irq_lateeoi(struct xenbus_device *dev,
1316 evtchn_port_t remote_port)
1317{
1318 return bind_interdomain_evtchn_to_irq_chip(dev, remote_port,
1319 chip: &xen_lateeoi_chip, shared: false);
1320}
1321EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq_lateeoi);
1322
1323static int find_virq(unsigned int virq, unsigned int cpu, evtchn_port_t *evtchn)
1324{
1325 struct evtchn_status status;
1326 evtchn_port_t port;
1327 int rc = -ENOENT;
1328
1329 memset(&status, 0, sizeof(status));
1330 for (port = 0; port < xen_evtchn_max_channels(); port++) {
1331 status.dom = DOMID_SELF;
1332 status.port = port;
1333 rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, arg: &status);
1334 if (rc < 0)
1335 continue;
1336 if (status.status != EVTCHNSTAT_virq)
1337 continue;
1338 if (status.u.virq == virq && status.vcpu == xen_vcpu_nr(cpu)) {
1339 *evtchn = port;
1340 break;
1341 }
1342 }
1343 return rc;
1344}
1345
1346/**
1347 * xen_evtchn_nr_channels - number of usable event channel ports
1348 *
1349 * This may be less than the maximum supported by the current
1350 * hypervisor ABI. Use xen_evtchn_max_channels() for the maximum
1351 * supported.
1352 */
1353unsigned xen_evtchn_nr_channels(void)
1354{
1355 return evtchn_ops->nr_channels();
1356}
1357EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
1358
1359int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
1360{
1361 struct evtchn_bind_virq bind_virq;
1362 evtchn_port_t evtchn = 0;
1363 struct irq_info *info;
1364 int ret;
1365
1366 mutex_lock(&irq_mapping_update_lock);
1367
1368 ret = per_cpu(virq_to_irq, cpu)[virq];
1369
1370 if (ret == -1) {
1371 info = xen_allocate_irq_dynamic();
1372 if (!info)
1373 goto out;
1374
1375 if (percpu)
1376 irq_set_chip_and_handler_name(irq: info->irq, chip: &xen_percpu_chip,
1377 handle: handle_percpu_irq, name: "virq");
1378 else
1379 irq_set_chip_and_handler_name(irq: info->irq, chip: &xen_dynamic_chip,
1380 handle: handle_edge_irq, name: "virq");
1381
1382 bind_virq.virq = virq;
1383 bind_virq.vcpu = xen_vcpu_nr(cpu);
1384 ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1385 arg: &bind_virq);
1386 if (ret == 0)
1387 evtchn = bind_virq.port;
1388 else {
1389 if (ret == -EEXIST)
1390 ret = find_virq(virq, cpu, evtchn: &evtchn);
1391 BUG_ON(ret < 0);
1392 }
1393
1394 ret = xen_irq_info_virq_setup(info, cpu, evtchn, virq);
1395 if (ret < 0) {
1396 __unbind_from_irq(info, irq: info->irq);
1397 goto out;
1398 }
1399
1400 /*
1401 * Force the affinity mask for percpu interrupts so proc
1402 * shows the correct target.
1403 */
1404 bind_evtchn_to_cpu(info, cpu, force_affinity: percpu);
1405 ret = info->irq;
1406 } else {
1407 info = info_for_irq(irq: ret);
1408 WARN_ON(info == NULL || info->type != IRQT_VIRQ);
1409 }
1410
1411out:
1412 mutex_unlock(lock: &irq_mapping_update_lock);
1413
1414 return ret;
1415}
1416
1417static void unbind_from_irq(unsigned int irq)
1418{
1419 struct irq_info *info;
1420
1421 mutex_lock(&irq_mapping_update_lock);
1422 info = info_for_irq(irq);
1423 __unbind_from_irq(info, irq);
1424 mutex_unlock(lock: &irq_mapping_update_lock);
1425}
1426
1427static int bind_evtchn_to_irqhandler_chip(evtchn_port_t evtchn,
1428 irq_handler_t handler,
1429 unsigned long irqflags,
1430 const char *devname, void *dev_id,
1431 struct irq_chip *chip)
1432{
1433 int irq, retval;
1434
1435 irq = bind_evtchn_to_irq_chip(evtchn, chip, NULL,
1436 shared: irqflags & IRQF_SHARED);
1437 if (irq < 0)
1438 return irq;
1439 retval = request_irq(irq, handler, flags: irqflags, name: devname, dev: dev_id);
1440 if (retval != 0) {
1441 unbind_from_irq(irq);
1442 return retval;
1443 }
1444
1445 return irq;
1446}
1447
1448int bind_evtchn_to_irqhandler(evtchn_port_t evtchn,
1449 irq_handler_t handler,
1450 unsigned long irqflags,
1451 const char *devname, void *dev_id)
1452{
1453 return bind_evtchn_to_irqhandler_chip(evtchn, handler, irqflags,
1454 devname, dev_id,
1455 chip: &xen_dynamic_chip);
1456}
1457EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
1458
1459int bind_evtchn_to_irqhandler_lateeoi(evtchn_port_t evtchn,
1460 irq_handler_t handler,
1461 unsigned long irqflags,
1462 const char *devname, void *dev_id)
1463{
1464 return bind_evtchn_to_irqhandler_chip(evtchn, handler, irqflags,
1465 devname, dev_id,
1466 chip: &xen_lateeoi_chip);
1467}
1468EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler_lateeoi);
1469
1470static int bind_interdomain_evtchn_to_irqhandler_chip(
1471 struct xenbus_device *dev, evtchn_port_t remote_port,
1472 irq_handler_t handler, unsigned long irqflags,
1473 const char *devname, void *dev_id, struct irq_chip *chip)
1474{
1475 int irq, retval;
1476
1477 irq = bind_interdomain_evtchn_to_irq_chip(dev, remote_port, chip,
1478 shared: irqflags & IRQF_SHARED);
1479 if (irq < 0)
1480 return irq;
1481
1482 retval = request_irq(irq, handler, flags: irqflags, name: devname, dev: dev_id);
1483 if (retval != 0) {
1484 unbind_from_irq(irq);
1485 return retval;
1486 }
1487
1488 return irq;
1489}
1490
1491int bind_interdomain_evtchn_to_irqhandler_lateeoi(struct xenbus_device *dev,
1492 evtchn_port_t remote_port,
1493 irq_handler_t handler,
1494 unsigned long irqflags,
1495 const char *devname,
1496 void *dev_id)
1497{
1498 return bind_interdomain_evtchn_to_irqhandler_chip(dev,
1499 remote_port, handler, irqflags, devname,
1500 dev_id, chip: &xen_lateeoi_chip);
1501}
1502EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler_lateeoi);
1503
1504int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
1505 irq_handler_t handler,
1506 unsigned long irqflags, const char *devname, void *dev_id)
1507{
1508 int irq, retval;
1509
1510 irq = bind_virq_to_irq(virq, cpu, percpu: irqflags & IRQF_PERCPU);
1511 if (irq < 0)
1512 return irq;
1513 retval = request_irq(irq, handler, flags: irqflags, name: devname, dev: dev_id);
1514 if (retval != 0) {
1515 unbind_from_irq(irq);
1516 return retval;
1517 }
1518
1519 return irq;
1520}
1521EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
1522
1523int bind_ipi_to_irqhandler(enum ipi_vector ipi,
1524 unsigned int cpu,
1525 irq_handler_t handler,
1526 unsigned long irqflags,
1527 const char *devname,
1528 void *dev_id)
1529{
1530 int irq, retval;
1531
1532 irq = bind_ipi_to_irq(ipi, cpu);
1533 if (irq < 0)
1534 return irq;
1535
1536 irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME | IRQF_EARLY_RESUME;
1537 retval = request_irq(irq, handler, flags: irqflags, name: devname, dev: dev_id);
1538 if (retval != 0) {
1539 unbind_from_irq(irq);
1540 return retval;
1541 }
1542
1543 return irq;
1544}
1545
1546void unbind_from_irqhandler(unsigned int irq, void *dev_id)
1547{
1548 struct irq_info *info = info_for_irq(irq);
1549
1550 if (WARN_ON(!info))
1551 return;
1552 free_irq(irq, dev_id);
1553 unbind_from_irq(irq);
1554}
1555EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
1556
1557/**
1558 * xen_set_irq_priority() - set an event channel priority.
1559 * @irq:irq bound to an event channel.
1560 * @priority: priority between XEN_IRQ_PRIORITY_MAX and XEN_IRQ_PRIORITY_MIN.
1561 */
1562int xen_set_irq_priority(unsigned irq, unsigned priority)
1563{
1564 struct evtchn_set_priority set_priority;
1565
1566 set_priority.port = evtchn_from_irq(irq);
1567 set_priority.priority = priority;
1568
1569 return HYPERVISOR_event_channel_op(EVTCHNOP_set_priority,
1570 arg: &set_priority);
1571}
1572EXPORT_SYMBOL_GPL(xen_set_irq_priority);
1573
1574int evtchn_make_refcounted(evtchn_port_t evtchn, bool is_static)
1575{
1576 struct irq_info *info = evtchn_to_info(evtchn);
1577
1578 if (!info)
1579 return -ENOENT;
1580
1581 WARN_ON(info->refcnt != -1);
1582
1583 info->refcnt = 1;
1584 info->is_static = is_static;
1585
1586 return 0;
1587}
1588EXPORT_SYMBOL_GPL(evtchn_make_refcounted);
1589
1590int evtchn_get(evtchn_port_t evtchn)
1591{
1592 struct irq_info *info;
1593 int err = -ENOENT;
1594
1595 if (evtchn >= xen_evtchn_max_channels())
1596 return -EINVAL;
1597
1598 mutex_lock(&irq_mapping_update_lock);
1599
1600 info = evtchn_to_info(evtchn);
1601
1602 if (!info)
1603 goto done;
1604
1605 err = -EINVAL;
1606 if (info->refcnt <= 0 || info->refcnt == SHRT_MAX)
1607 goto done;
1608
1609 info->refcnt++;
1610 err = 0;
1611 done:
1612 mutex_unlock(lock: &irq_mapping_update_lock);
1613
1614 return err;
1615}
1616EXPORT_SYMBOL_GPL(evtchn_get);
1617
1618void evtchn_put(evtchn_port_t evtchn)
1619{
1620 struct irq_info *info = evtchn_to_info(evtchn);
1621
1622 if (WARN_ON(!info))
1623 return;
1624 unbind_from_irq(irq: info->irq);
1625}
1626EXPORT_SYMBOL_GPL(evtchn_put);
1627
1628void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
1629{
1630 evtchn_port_t evtchn;
1631
1632#ifdef CONFIG_X86
1633 if (unlikely(vector == XEN_NMI_VECTOR)) {
1634 int rc = HYPERVISOR_vcpu_op(VCPUOP_send_nmi, vcpuid: xen_vcpu_nr(cpu),
1635 NULL);
1636 if (rc < 0)
1637 printk(KERN_WARNING "Sending nmi to CPU%d failed (rc:%d)\n", cpu, rc);
1638 return;
1639 }
1640#endif
1641 evtchn = per_cpu(ipi_to_evtchn, cpu)[vector];
1642 BUG_ON(evtchn == 0);
1643 notify_remote_via_evtchn(port: evtchn);
1644}
1645
1646struct evtchn_loop_ctrl {
1647 ktime_t timeout;
1648 unsigned count;
1649 bool defer_eoi;
1650};
1651
1652void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl)
1653{
1654 struct irq_info *info = evtchn_to_info(evtchn: port);
1655 struct xenbus_device *dev;
1656
1657 if (!info)
1658 return;
1659
1660 /*
1661 * Check for timeout every 256 events.
1662 * We are setting the timeout value only after the first 256
1663 * events in order to not hurt the common case of few loop
1664 * iterations. The 256 is basically an arbitrary value.
1665 *
1666 * In case we are hitting the timeout we need to defer all further
1667 * EOIs in order to ensure to leave the event handling loop rather
1668 * sooner than later.
1669 */
1670 if (!ctrl->defer_eoi && !(++ctrl->count & 0xff)) {
1671 ktime_t kt = ktime_get();
1672
1673 if (!ctrl->timeout) {
1674 kt = ktime_add_ms(kt,
1675 msec: jiffies_to_msecs(j: event_loop_timeout));
1676 ctrl->timeout = kt;
1677 } else if (kt > ctrl->timeout) {
1678 ctrl->defer_eoi = true;
1679 }
1680 }
1681
1682 if (xchg_acquire(&info->is_active, 1))
1683 return;
1684
1685 dev = (info->type == IRQT_EVTCHN) ? info->u.interdomain : NULL;
1686 if (dev)
1687 atomic_inc(v: &dev->events);
1688
1689 if (ctrl->defer_eoi) {
1690 info->eoi_cpu = smp_processor_id();
1691 info->irq_epoch = __this_cpu_read(irq_epoch);
1692 info->eoi_time = get_jiffies_64() + event_eoi_delay;
1693 }
1694
1695 generic_handle_irq(irq: info->irq);
1696}
1697
1698int xen_evtchn_do_upcall(void)
1699{
1700 struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1701 int ret = vcpu_info->evtchn_upcall_pending ? IRQ_HANDLED : IRQ_NONE;
1702 int cpu = smp_processor_id();
1703 struct evtchn_loop_ctrl ctrl = { 0 };
1704
1705 /*
1706 * When closing an event channel the associated IRQ must not be freed
1707 * until all cpus have left the event handling loop. This is ensured
1708 * by taking the rcu_read_lock() while handling events, as freeing of
1709 * the IRQ is handled via queue_rcu_work() _after_ closing the event
1710 * channel.
1711 */
1712 rcu_read_lock();
1713
1714 do {
1715 vcpu_info->evtchn_upcall_pending = 0;
1716
1717 xen_evtchn_handle_events(cpu, ctrl: &ctrl);
1718
1719 BUG_ON(!irqs_disabled());
1720
1721 virt_rmb(); /* Hypervisor can set upcall pending. */
1722
1723 } while (vcpu_info->evtchn_upcall_pending);
1724
1725 rcu_read_unlock();
1726
1727 /*
1728 * Increment irq_epoch only now to defer EOIs only for
1729 * xen_irq_lateeoi() invocations occurring from inside the loop
1730 * above.
1731 */
1732 __this_cpu_inc(irq_epoch);
1733
1734 return ret;
1735}
1736EXPORT_SYMBOL_GPL(xen_evtchn_do_upcall);
1737
1738/* Rebind a new event channel to an existing irq. */
1739void rebind_evtchn_irq(evtchn_port_t evtchn, int irq)
1740{
1741 struct irq_info *info = info_for_irq(irq);
1742
1743 if (WARN_ON(!info))
1744 return;
1745
1746 /* Make sure the irq is masked, since the new event channel
1747 will also be masked. */
1748 disable_irq(irq);
1749
1750 mutex_lock(&irq_mapping_update_lock);
1751
1752 /* After resume the irq<->evtchn mappings are all cleared out */
1753 BUG_ON(evtchn_to_info(evtchn));
1754 /* Expect irq to have been bound before,
1755 so there should be a proper type */
1756 BUG_ON(info->type == IRQT_UNBOUND);
1757
1758 info->irq = irq;
1759 (void)xen_irq_info_evtchn_setup(info, evtchn, NULL);
1760
1761 mutex_unlock(lock: &irq_mapping_update_lock);
1762
1763 bind_evtchn_to_cpu(info, cpu: info->cpu, force_affinity: false);
1764
1765 /* Unmask the event channel. */
1766 enable_irq(irq);
1767}
1768
1769/* Rebind an evtchn so that it gets delivered to a specific cpu */
1770static int xen_rebind_evtchn_to_cpu(struct irq_info *info, unsigned int tcpu)
1771{
1772 struct evtchn_bind_vcpu bind_vcpu;
1773 evtchn_port_t evtchn = info ? info->evtchn : 0;
1774
1775 if (!VALID_EVTCHN(evtchn))
1776 return -1;
1777
1778 if (!xen_support_evtchn_rebind())
1779 return -1;
1780
1781 /* Send future instances of this interrupt to other vcpu. */
1782 bind_vcpu.port = evtchn;
1783 bind_vcpu.vcpu = xen_vcpu_nr(cpu: tcpu);
1784
1785 /*
1786 * Mask the event while changing the VCPU binding to prevent
1787 * it being delivered on an unexpected VCPU.
1788 */
1789 do_mask(info, EVT_MASK_REASON_TEMPORARY);
1790
1791 /*
1792 * If this fails, it usually just indicates that we're dealing with a
1793 * virq or IPI channel, which don't actually need to be rebound. Ignore
1794 * it, but don't do the xenlinux-level rebind in that case.
1795 */
1796 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, arg: &bind_vcpu) >= 0)
1797 bind_evtchn_to_cpu(info, cpu: tcpu, force_affinity: false);
1798
1799 do_unmask(info, EVT_MASK_REASON_TEMPORARY);
1800
1801 return 0;
1802}
1803
1804/*
1805 * Find the CPU within @dest mask which has the least number of channels
1806 * assigned. This is not precise as the per cpu counts can be modified
1807 * concurrently.
1808 */
1809static unsigned int select_target_cpu(const struct cpumask *dest)
1810{
1811 unsigned int cpu, best_cpu = UINT_MAX, minch = UINT_MAX;
1812
1813 for_each_cpu_and(cpu, dest, cpu_online_mask) {
1814 unsigned int curch = atomic_read(v: &channels_on_cpu[cpu]);
1815
1816 if (curch < minch) {
1817 minch = curch;
1818 best_cpu = cpu;
1819 }
1820 }
1821
1822 /*
1823 * Catch the unlikely case that dest contains no online CPUs. Can't
1824 * recurse.
1825 */
1826 if (best_cpu == UINT_MAX)
1827 return select_target_cpu(cpu_online_mask);
1828
1829 return best_cpu;
1830}
1831
1832static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1833 bool force)
1834{
1835 unsigned int tcpu = select_target_cpu(dest);
1836 int ret;
1837
1838 ret = xen_rebind_evtchn_to_cpu(info: info_for_irq(irq: data->irq), tcpu);
1839 if (!ret)
1840 irq_data_update_effective_affinity(d: data, cpumask_of(tcpu));
1841
1842 return ret;
1843}
1844
1845static void enable_dynirq(struct irq_data *data)
1846{
1847 struct irq_info *info = info_for_irq(irq: data->irq);
1848 evtchn_port_t evtchn = info ? info->evtchn : 0;
1849
1850 if (VALID_EVTCHN(evtchn))
1851 do_unmask(info, EVT_MASK_REASON_EXPLICIT);
1852}
1853
1854static void do_ack_dynirq(struct irq_info *info)
1855{
1856 evtchn_port_t evtchn = info->evtchn;
1857
1858 if (VALID_EVTCHN(evtchn))
1859 event_handler_exit(info);
1860}
1861
1862static void ack_dynirq(struct irq_data *data)
1863{
1864 struct irq_info *info = info_for_irq(irq: data->irq);
1865
1866 if (info)
1867 do_ack_dynirq(info);
1868}
1869
1870static void mask_ack_dynirq(struct irq_data *data)
1871{
1872 struct irq_info *info = info_for_irq(irq: data->irq);
1873
1874 if (info) {
1875 do_disable_dynirq(info);
1876 do_ack_dynirq(info);
1877 }
1878}
1879
1880static void lateeoi_ack_dynirq(struct irq_data *data)
1881{
1882 struct irq_info *info = info_for_irq(irq: data->irq);
1883 evtchn_port_t evtchn = info ? info->evtchn : 0;
1884
1885 if (VALID_EVTCHN(evtchn)) {
1886 do_mask(info, EVT_MASK_REASON_EOI_PENDING);
1887 /*
1888 * Don't call event_handler_exit().
1889 * Need to keep is_active non-zero in order to ignore re-raised
1890 * events after cpu affinity changes while a lateeoi is pending.
1891 */
1892 clear_evtchn(port: evtchn);
1893 }
1894}
1895
1896static void lateeoi_mask_ack_dynirq(struct irq_data *data)
1897{
1898 struct irq_info *info = info_for_irq(irq: data->irq);
1899 evtchn_port_t evtchn = info ? info->evtchn : 0;
1900
1901 if (VALID_EVTCHN(evtchn)) {
1902 do_mask(info, EVT_MASK_REASON_EXPLICIT);
1903 event_handler_exit(info);
1904 }
1905}
1906
1907static int retrigger_dynirq(struct irq_data *data)
1908{
1909 struct irq_info *info = info_for_irq(irq: data->irq);
1910 evtchn_port_t evtchn = info ? info->evtchn : 0;
1911
1912 if (!VALID_EVTCHN(evtchn))
1913 return 0;
1914
1915 do_mask(info, EVT_MASK_REASON_TEMPORARY);
1916 set_evtchn(evtchn);
1917 do_unmask(info, EVT_MASK_REASON_TEMPORARY);
1918
1919 return 1;
1920}
1921
1922static void restore_pirqs(void)
1923{
1924 int pirq, rc, irq, gsi;
1925 struct physdev_map_pirq map_irq;
1926 struct irq_info *info;
1927
1928 list_for_each_entry(info, &xen_irq_list_head, list) {
1929 if (info->type != IRQT_PIRQ)
1930 continue;
1931
1932 pirq = info->u.pirq.pirq;
1933 gsi = info->u.pirq.gsi;
1934 irq = info->irq;
1935
1936 /* save/restore of PT devices doesn't work, so at this point the
1937 * only devices present are GSI based emulated devices */
1938 if (!gsi)
1939 continue;
1940
1941 map_irq.domid = DOMID_SELF;
1942 map_irq.type = MAP_PIRQ_TYPE_GSI;
1943 map_irq.index = gsi;
1944 map_irq.pirq = pirq;
1945
1946 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, arg: &map_irq);
1947 if (rc) {
1948 pr_warn("xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1949 gsi, irq, pirq, rc);
1950 xen_free_irq(info);
1951 continue;
1952 }
1953
1954 printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1955
1956 __startup_pirq(info);
1957 }
1958}
1959
1960static void restore_cpu_virqs(unsigned int cpu)
1961{
1962 struct evtchn_bind_virq bind_virq;
1963 evtchn_port_t evtchn;
1964 struct irq_info *info;
1965 int virq, irq;
1966
1967 for (virq = 0; virq < NR_VIRQS; virq++) {
1968 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1969 continue;
1970 info = info_for_irq(irq);
1971
1972 BUG_ON(virq_from_irq(info) != virq);
1973
1974 /* Get a new binding from Xen. */
1975 bind_virq.virq = virq;
1976 bind_virq.vcpu = xen_vcpu_nr(cpu);
1977 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1978 arg: &bind_virq) != 0)
1979 BUG();
1980 evtchn = bind_virq.port;
1981
1982 /* Record the new mapping. */
1983 xen_irq_info_virq_setup(info, cpu, evtchn, virq);
1984 /* The affinity mask is still valid */
1985 bind_evtchn_to_cpu(info, cpu, force_affinity: false);
1986 }
1987}
1988
1989static void restore_cpu_ipis(unsigned int cpu)
1990{
1991 struct evtchn_bind_ipi bind_ipi;
1992 evtchn_port_t evtchn;
1993 struct irq_info *info;
1994 int ipi, irq;
1995
1996 for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1997 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1998 continue;
1999 info = info_for_irq(irq);
2000
2001 BUG_ON(ipi_from_irq(info) != ipi);
2002
2003 /* Get a new binding from Xen. */
2004 bind_ipi.vcpu = xen_vcpu_nr(cpu);
2005 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
2006 arg: &bind_ipi) != 0)
2007 BUG();
2008 evtchn = bind_ipi.port;
2009
2010 /* Record the new mapping. */
2011 xen_irq_info_ipi_setup(info, cpu, evtchn, ipi);
2012 /* The affinity mask is still valid */
2013 bind_evtchn_to_cpu(info, cpu, force_affinity: false);
2014 }
2015}
2016
2017/* Clear an irq's pending state, in preparation for polling on it */
2018void xen_clear_irq_pending(int irq)
2019{
2020 struct irq_info *info = info_for_irq(irq);
2021 evtchn_port_t evtchn = info ? info->evtchn : 0;
2022
2023 if (VALID_EVTCHN(evtchn))
2024 event_handler_exit(info);
2025}
2026EXPORT_SYMBOL(xen_clear_irq_pending);
2027
2028bool xen_test_irq_pending(int irq)
2029{
2030 evtchn_port_t evtchn = evtchn_from_irq(irq);
2031 bool ret = false;
2032
2033 if (VALID_EVTCHN(evtchn))
2034 ret = test_evtchn(port: evtchn);
2035
2036 return ret;
2037}
2038
2039/* Poll waiting for an irq to become pending with timeout. In the usual case,
2040 * the irq will be disabled so it won't deliver an interrupt. */
2041void xen_poll_irq_timeout(int irq, u64 timeout)
2042{
2043 evtchn_port_t evtchn = evtchn_from_irq(irq);
2044
2045 if (VALID_EVTCHN(evtchn)) {
2046 struct sched_poll poll;
2047
2048 poll.nr_ports = 1;
2049 poll.timeout = timeout;
2050 set_xen_guest_handle(poll.ports, &evtchn);
2051
2052 if (HYPERVISOR_sched_op(SCHEDOP_poll, arg: &poll) != 0)
2053 BUG();
2054 }
2055}
2056EXPORT_SYMBOL(xen_poll_irq_timeout);
2057/* Poll waiting for an irq to become pending. In the usual case, the
2058 * irq will be disabled so it won't deliver an interrupt. */
2059void xen_poll_irq(int irq)
2060{
2061 xen_poll_irq_timeout(irq, 0 /* no timeout */);
2062}
2063
2064/* Check whether the IRQ line is shared with other guests. */
2065int xen_test_irq_shared(int irq)
2066{
2067 struct irq_info *info = info_for_irq(irq);
2068 struct physdev_irq_status_query irq_status;
2069
2070 if (WARN_ON(!info))
2071 return -ENOENT;
2072
2073 irq_status.irq = info->u.pirq.pirq;
2074
2075 if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, arg: &irq_status))
2076 return 0;
2077 return !(irq_status.flags & XENIRQSTAT_shared);
2078}
2079EXPORT_SYMBOL_GPL(xen_test_irq_shared);
2080
2081void xen_irq_resume(void)
2082{
2083 unsigned int cpu;
2084 struct irq_info *info;
2085
2086 /* New event-channel space is not 'live' yet. */
2087 xen_evtchn_resume();
2088
2089 /* No IRQ <-> event-channel mappings. */
2090 list_for_each_entry(info, &xen_irq_list_head, list) {
2091 /* Zap event-channel binding */
2092 info->evtchn = 0;
2093 /* Adjust accounting */
2094 channels_on_cpu_dec(info);
2095 }
2096
2097 clear_evtchn_to_irq_all();
2098
2099 for_each_possible_cpu(cpu) {
2100 restore_cpu_virqs(cpu);
2101 restore_cpu_ipis(cpu);
2102 }
2103
2104 restore_pirqs();
2105}
2106
2107static struct irq_chip xen_dynamic_chip __read_mostly = {
2108 .name = "xen-dyn",
2109
2110 .irq_disable = disable_dynirq,
2111 .irq_mask = disable_dynirq,
2112 .irq_unmask = enable_dynirq,
2113
2114 .irq_ack = ack_dynirq,
2115 .irq_mask_ack = mask_ack_dynirq,
2116
2117 .irq_set_affinity = set_affinity_irq,
2118 .irq_retrigger = retrigger_dynirq,
2119};
2120
2121static struct irq_chip xen_lateeoi_chip __read_mostly = {
2122 /* The chip name needs to contain "xen-dyn" for irqbalance to work. */
2123 .name = "xen-dyn-lateeoi",
2124
2125 .irq_disable = disable_dynirq,
2126 .irq_mask = disable_dynirq,
2127 .irq_unmask = enable_dynirq,
2128
2129 .irq_ack = lateeoi_ack_dynirq,
2130 .irq_mask_ack = lateeoi_mask_ack_dynirq,
2131
2132 .irq_set_affinity = set_affinity_irq,
2133 .irq_retrigger = retrigger_dynirq,
2134};
2135
2136static struct irq_chip xen_pirq_chip __read_mostly = {
2137 .name = "xen-pirq",
2138
2139 .irq_startup = startup_pirq,
2140 .irq_shutdown = shutdown_pirq,
2141 .irq_enable = enable_pirq,
2142 .irq_disable = disable_pirq,
2143
2144 .irq_mask = disable_dynirq,
2145 .irq_unmask = enable_dynirq,
2146
2147 .irq_ack = eoi_pirq,
2148 .irq_eoi = eoi_pirq,
2149 .irq_mask_ack = mask_ack_pirq,
2150
2151 .irq_set_affinity = set_affinity_irq,
2152
2153 .irq_retrigger = retrigger_dynirq,
2154};
2155
2156static struct irq_chip xen_percpu_chip __read_mostly = {
2157 .name = "xen-percpu",
2158
2159 .irq_disable = disable_dynirq,
2160 .irq_mask = disable_dynirq,
2161 .irq_unmask = enable_dynirq,
2162
2163 .irq_ack = ack_dynirq,
2164};
2165
2166#ifdef CONFIG_X86
2167#ifdef CONFIG_XEN_PVHVM
2168/* Vector callbacks are better than PCI interrupts to receive event
2169 * channel notifications because we can receive vector callbacks on any
2170 * vcpu and we don't need PCI support or APIC interactions. */
2171void xen_setup_callback_vector(void)
2172{
2173 uint64_t callback_via;
2174
2175 if (xen_have_vector_callback) {
2176 callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
2177 if (xen_set_callback_via(via: callback_via)) {
2178 pr_err("Request for Xen HVM callback vector failed\n");
2179 xen_have_vector_callback = false;
2180 }
2181 }
2182}
2183
2184/*
2185 * Setup per-vCPU vector-type callbacks. If this setup is unavailable,
2186 * fallback to the global vector-type callback.
2187 */
2188static __init void xen_init_setup_upcall_vector(void)
2189{
2190 if (!xen_have_vector_callback)
2191 return;
2192
2193 if ((cpuid_eax(op: xen_cpuid_base() + 4) & XEN_HVM_CPUID_UPCALL_VECTOR) &&
2194 !xen_set_upcall_vector(cpu: 0))
2195 xen_percpu_upcall = true;
2196 else if (xen_feature(XENFEAT_hvm_callback_vector))
2197 xen_setup_callback_vector();
2198 else
2199 xen_have_vector_callback = false;
2200}
2201
2202int xen_set_upcall_vector(unsigned int cpu)
2203{
2204 int rc;
2205 xen_hvm_evtchn_upcall_vector_t op = {
2206 .vector = HYPERVISOR_CALLBACK_VECTOR,
2207 .vcpu = per_cpu(xen_vcpu_id, cpu),
2208 };
2209
2210 rc = HYPERVISOR_hvm_op(HVMOP_set_evtchn_upcall_vector, arg: &op);
2211 if (rc)
2212 return rc;
2213
2214 /* Trick toolstack to think we are enlightened. */
2215 if (!cpu)
2216 rc = xen_set_callback_via(via: 1);
2217
2218 return rc;
2219}
2220
2221static __init void xen_alloc_callback_vector(void)
2222{
2223 if (!xen_have_vector_callback)
2224 return;
2225
2226 pr_info("Xen HVM callback vector for event delivery is enabled\n");
2227 sysvec_install(HYPERVISOR_CALLBACK_VECTOR, sysvec_xen_hvm_callback);
2228}
2229#else
2230void xen_setup_callback_vector(void) {}
2231static inline void xen_init_setup_upcall_vector(void) {}
2232int xen_set_upcall_vector(unsigned int cpu) {}
2233static inline void xen_alloc_callback_vector(void) {}
2234#endif /* CONFIG_XEN_PVHVM */
2235#endif /* CONFIG_X86 */
2236
2237bool xen_fifo_events = true;
2238module_param_named(fifo_events, xen_fifo_events, bool, 0);
2239
2240static int xen_evtchn_cpu_prepare(unsigned int cpu)
2241{
2242 int ret = 0;
2243
2244 xen_cpu_init_eoi(cpu);
2245
2246 if (evtchn_ops->percpu_init)
2247 ret = evtchn_ops->percpu_init(cpu);
2248
2249 return ret;
2250}
2251
2252static int xen_evtchn_cpu_dead(unsigned int cpu)
2253{
2254 int ret = 0;
2255
2256 if (evtchn_ops->percpu_deinit)
2257 ret = evtchn_ops->percpu_deinit(cpu);
2258
2259 return ret;
2260}
2261
2262void __init xen_init_IRQ(void)
2263{
2264 int ret = -EINVAL;
2265 evtchn_port_t evtchn;
2266
2267 if (xen_fifo_events)
2268 ret = xen_evtchn_fifo_init();
2269 if (ret < 0) {
2270 xen_evtchn_2l_init();
2271 xen_fifo_events = false;
2272 }
2273
2274 xen_cpu_init_eoi(smp_processor_id());
2275
2276 cpuhp_setup_state_nocalls(state: CPUHP_XEN_EVTCHN_PREPARE,
2277 name: "xen/evtchn:prepare",
2278 startup: xen_evtchn_cpu_prepare, teardown: xen_evtchn_cpu_dead);
2279
2280 evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()),
2281 size: sizeof(*evtchn_to_irq), GFP_KERNEL);
2282 BUG_ON(!evtchn_to_irq);
2283
2284 /* No event channels are 'live' right now. */
2285 for (evtchn = 0; evtchn < xen_evtchn_nr_channels(); evtchn++)
2286 mask_evtchn(port: evtchn);
2287
2288 pirq_needs_eoi = pirq_needs_eoi_flag;
2289
2290#ifdef CONFIG_X86
2291 if (xen_pv_domain()) {
2292 if (xen_initial_domain())
2293 pci_xen_initial_domain();
2294 }
2295 xen_init_setup_upcall_vector();
2296 xen_alloc_callback_vector();
2297
2298
2299 if (xen_hvm_domain()) {
2300 native_init_IRQ();
2301 /* pci_xen_hvm_init must be called after native_init_IRQ so that
2302 * __acpi_register_gsi can point at the right function */
2303 pci_xen_hvm_init();
2304 } else {
2305 int rc;
2306 struct physdev_pirq_eoi_gmfn eoi_gmfn;
2307
2308 pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
2309 eoi_gmfn.gmfn = virt_to_gfn(pirq_eoi_map);
2310 rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, arg: &eoi_gmfn);
2311 if (rc != 0) {
2312 free_page((unsigned long) pirq_eoi_map);
2313 pirq_eoi_map = NULL;
2314 } else
2315 pirq_needs_eoi = pirq_check_eoi_map;
2316 }
2317#endif
2318}
2319

source code of linux/drivers/xen/events/events_base.c