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. */
77 enum 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 */
97 struct 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
137 static uint __read_mostly event_loop_timeout = 2;
138 module_param(event_loop_timeout, uint, 0644);
139
140 static uint __read_mostly event_eoi_delay = 10;
141 module_param(event_eoi_delay, uint, 0644);
142
143 const 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 */
149 static 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
160 static LIST_HEAD(xen_irq_list_head);
161
162 /* IRQ <-> VIRQ mapping. */
163 static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
164
165 /* IRQ <-> IPI mapping */
166 static 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). */
168 static DEFINE_PER_CPU(evtchn_port_t [XEN_NR_IPIS], ipi_to_evtchn) = {[0 ... XEN_NR_IPIS-1] = 0};
169
170 /* Event channel distribution data */
171 static atomic_t channels_on_cpu[NR_CPUS];
172
173 static int **evtchn_to_irq;
174 #ifdef CONFIG_X86
175 static unsigned long *pirq_eoi_map;
176 #endif
177 static 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
186 static struct irq_info *legacy_info_ptrs[NR_IRQS_LEGACY];
187
188 static struct irq_chip xen_dynamic_chip;
189 static struct irq_chip xen_lateeoi_chip;
190 static struct irq_chip xen_percpu_chip;
191 static struct irq_chip xen_pirq_chip;
192 static void enable_dynirq(struct irq_data *data);
193
194 static DEFINE_PER_CPU(unsigned int, irq_epoch);
195
clear_evtchn_to_irq_row(int * evtchn_row)196 static 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
clear_evtchn_to_irq_all(void)204 static 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_to_irq[row]);
212 }
213 }
214
set_evtchn_to_irq(evtchn_port_t evtchn,unsigned int irq)215 static 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, 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 */
info_for_irq(unsigned irq)251 static 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
set_info_for_irq(unsigned int irq,struct irq_info * info)259 static 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, info);
265 }
266
evtchn_to_info(evtchn_port_t evtchn)267 static 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 */
channels_on_cpu_dec(struct irq_info * info)281 static 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
channels_on_cpu_inc(struct irq_info * info)294 static 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
xen_irq_free_desc(unsigned int irq)306 static 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
delayed_free_irq(struct work_struct * work)313 static 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(info);
323
324 xen_irq_free_desc(irq);
325 }
326
327 /* Constructors for packed IRQ information. */
xen_irq_info_common_setup(struct irq_info * info,enum xen_irq_type type,evtchn_port_t evtchn,unsigned short cpu)328 static 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, info->irq);
344 if (ret < 0)
345 return ret;
346
347 irq_clear_status_flags(info->irq, IRQ_NOREQUEST | IRQ_NOAUTOEN);
348
349 return xen_evtchn_port_setup(evtchn);
350 }
351
xen_irq_info_evtchn_setup(struct irq_info * info,evtchn_port_t evtchn,struct xenbus_device * dev)352 static 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, IRQT_EVTCHN, evtchn, 0);
359 info->u.interdomain = dev;
360 if (dev)
361 atomic_inc(&dev->event_channels);
362
363 return ret;
364 }
365
xen_irq_info_ipi_setup(struct irq_info * info,unsigned int cpu,evtchn_port_t evtchn,enum ipi_vector ipi)366 static 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, IRQT_IPI, evtchn, 0);
375 }
376
xen_irq_info_virq_setup(struct irq_info * info,unsigned int cpu,evtchn_port_t evtchn,unsigned int virq)377 static 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, IRQT_VIRQ, evtchn, 0);
385 }
386
xen_irq_info_pirq_setup(struct irq_info * info,evtchn_port_t evtchn,unsigned int pirq,unsigned int gsi,uint16_t domid,unsigned char flags)387 static 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, IRQT_PIRQ, evtchn, 0);
397 }
398
xen_irq_info_cleanup(struct irq_info * info)399 static void xen_irq_info_cleanup(struct irq_info *info)
400 {
401 set_evtchn_to_irq(info->evtchn, -1);
402 xen_evtchn_port_remove(info->evtchn, info->cpu);
403 info->evtchn = 0;
404 channels_on_cpu_dec(info);
405 }
406
407 /*
408 * Accessors for packed IRQ information.
409 */
evtchn_from_irq(unsigned int irq)410 static 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
irq_from_evtchn(evtchn_port_t evtchn)422 unsigned 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 }
428 EXPORT_SYMBOL_GPL(irq_from_evtchn);
429
irq_evtchn_from_virq(unsigned int cpu,unsigned int virq,evtchn_port_t * evtchn)430 int 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
ipi_from_irq(struct irq_info * info)440 static 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
virq_from_irq(struct irq_info * info)448 static 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
pirq_from_irq(struct irq_info * info)456 static 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
cpu_from_evtchn(evtchn_port_t evtchn)464 unsigned 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
do_mask(struct irq_info * info,u8 reason)471 static 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(info->evtchn);
479
480 info->mask_reason |= reason;
481
482 raw_spin_unlock_irqrestore(&info->lock, flags);
483 }
484
do_unmask(struct irq_info * info,u8 reason)485 static 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(info->evtchn);
495
496 raw_spin_unlock_irqrestore(&info->lock, flags);
497 }
498
499 #ifdef CONFIG_X86
pirq_check_eoi_map(struct irq_info * info)500 static 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
pirq_needs_eoi_flag(struct irq_info * info)506 static 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
bind_evtchn_to_cpu(struct irq_info * info,unsigned int cpu,bool force_affinity)513 static 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(info->irq);
518
519 irq_data_update_affinity(data, cpumask_of(cpu));
520 irq_data_update_effective_affinity(data, cpumask_of(cpu));
521 }
522
523 xen_evtchn_port_bind_to_cpu(info->evtchn, 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 */
notify_remote_via_irq(int irq)538 void 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(evtchn);
544 }
545 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
546
547 struct lateeoi_work {
548 struct delayed_work delayed;
549 spinlock_t eoi_list_lock;
550 struct list_head eoi_list;
551 };
552
553 static DEFINE_PER_CPU(struct lateeoi_work, lateeoi);
554
lateeoi_list_del(struct irq_info * info)555 static 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(&info->eoi_list);
562 spin_unlock_irqrestore(&eoi->eoi_list_lock, flags);
563 }
564
lateeoi_list_add(struct irq_info * info)565 static 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(&info->eoi_list, &eoi->eoi_list);
584 mod_delayed_work_on(info->eoi_cpu, system_wq,
585 &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(&info->eoi_list, &elem->eoi_list);
592 }
593
594 spin_unlock_irqrestore(&eoi->eoi_list_lock, flags);
595 }
596
xen_irq_lateeoi_locked(struct irq_info * info,bool spurious)597 static 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(&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(delay, &dev->jiffies_eoi_delayed);
627 }
628 if (dev)
629 atomic_inc(&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
xen_irq_lateeoi_worker(struct work_struct * work)648 static 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(info->eoi_cpu, system_wq,
670 &eoi->delayed,
671 info->eoi_time - now);
672 break;
673 }
674
675 list_del_init(&info->eoi_list);
676
677 spin_unlock_irqrestore(&eoi->eoi_list_lock, flags);
678
679 info->eoi_time = 0;
680
681 xen_irq_lateeoi_locked(info, false);
682 }
683
684 spin_unlock_irqrestore(&eoi->eoi_list_lock, flags);
685
686 rcu_read_unlock();
687 }
688
xen_cpu_init_eoi(unsigned int cpu)689 static 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(&eoi->eoi_list);
696 }
697
xen_irq_lateeoi(unsigned int irq,unsigned int eoi_flags)698 void 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, eoi_flags & XEN_EOI_FLAG_SPURIOUS);
708
709 rcu_read_unlock();
710 }
711 EXPORT_SYMBOL_GPL(xen_irq_lateeoi);
712
xen_irq_init(unsigned int irq)713 static struct irq_info *xen_irq_init(unsigned int irq)
714 {
715 struct irq_info *info;
716
717 info = kzalloc(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, IRQ_MOVE_PCNTXT);
730
731 INIT_LIST_HEAD(&info->eoi_list);
732 list_add_tail(&info->list, &xen_irq_list_head);
733 }
734
735 return info;
736 }
737
xen_allocate_irq_dynamic(void)738 static 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
xen_allocate_irq_gsi(unsigned int gsi)752 static 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
xen_free_irq(struct irq_info * info)779 static void xen_free_irq(struct irq_info *info)
780 {
781 if (WARN_ON(!info))
782 return;
783
784 if (!list_empty(&info->eoi_list))
785 lateeoi_list_del(info);
786
787 list_del(&info->list);
788
789 WARN_ON(info->refcnt > 0);
790
791 queue_rcu_work(system_wq, &info->rwork);
792 }
793
794 /* Not called for lateeoi events. */
event_handler_exit(struct irq_info * info)795 static void event_handler_exit(struct irq_info *info)
796 {
797 smp_store_release(&info->is_active, 0);
798 clear_evtchn(info->evtchn);
799 }
800
pirq_query_unmask(struct irq_info * info)801 static 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, &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
do_eoi_pirq(struct irq_info * info)814 static 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, &eoi);
826 WARN_ON(rc);
827 }
828 }
829
eoi_pirq(struct irq_data * data)830 static void eoi_pirq(struct irq_data *data)
831 {
832 struct irq_info *info = info_for_irq(data->irq);
833
834 do_eoi_pirq(info);
835 }
836
do_disable_dynirq(struct irq_info * info)837 static 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
disable_dynirq(struct irq_data * data)843 static void disable_dynirq(struct irq_data *data)
844 {
845 struct irq_info *info = info_for_irq(data->irq);
846
847 if (info)
848 do_disable_dynirq(info);
849 }
850
mask_ack_pirq(struct irq_data * data)851 static void mask_ack_pirq(struct irq_data *data)
852 {
853 struct irq_info *info = info_for_irq(data->irq);
854
855 if (info) {
856 do_disable_dynirq(info);
857 do_eoi_pirq(info);
858 }
859 }
860
__startup_pirq(struct irq_info * info)861 static 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, &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, info->irq);
884 if (rc)
885 goto err;
886
887 info->evtchn = evtchn;
888 bind_evtchn_to_cpu(info, 0, false);
889
890 rc = xen_evtchn_port_setup(evtchn);
891 if (rc)
892 goto err;
893
894 out:
895 do_unmask(info, EVT_MASK_REASON_EXPLICIT);
896
897 do_eoi_pirq(info);
898
899 return 0;
900
901 err:
902 pr_err("irq%d: Failed to set port to irq mapping (%d)\n", info->irq,
903 rc);
904 xen_evtchn_close(evtchn);
905 return 0;
906 }
907
startup_pirq(struct irq_data * data)908 static unsigned int startup_pirq(struct irq_data *data)
909 {
910 struct irq_info *info = info_for_irq(data->irq);
911
912 return __startup_pirq(info);
913 }
914
shutdown_pirq(struct irq_data * data)915 static void shutdown_pirq(struct irq_data *data)
916 {
917 struct irq_info *info = info_for_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(evtchn);
928 }
929
enable_pirq(struct irq_data * data)930 static void enable_pirq(struct irq_data *data)
931 {
932 enable_dynirq(data);
933 }
934
disable_pirq(struct irq_data * data)935 static void disable_pirq(struct irq_data *data)
936 {
937 disable_dynirq(data);
938 }
939
xen_irq_from_gsi(unsigned gsi)940 int 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 }
954 EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
955
__unbind_from_irq(struct irq_info * info,unsigned int irq)956 static 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(&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(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 */
xen_bind_pirq_gsi_to_irq(unsigned gsi,unsigned pirq,int shareable,char * name)1017 int 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, &irq_op)) {
1045 xen_free_irq(info);
1046 ret = -ENOSPC;
1047 goto out;
1048 }
1049
1050 ret = xen_irq_info_pirq_setup(info, 0, pirq, gsi, DOMID_SELF,
1051 shareable ? PIRQ_SHAREABLE : 0);
1052 if (ret < 0) {
1053 __unbind_from_irq(info, 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(info->irq, &xen_pirq_chip,
1075 handle_fasteoi_irq, name);
1076 else
1077 irq_set_chip_and_handler_name(info->irq, &xen_pirq_chip,
1078 handle_edge_irq, name);
1079
1080 ret = info->irq;
1081
1082 out:
1083 mutex_unlock(&irq_mapping_update_lock);
1084
1085 return ret;
1086 }
1087
1088 #ifdef CONFIG_PCI_MSI
xen_allocate_pirq_msi(struct pci_dev * dev,struct msi_desc * msidesc)1089 int 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, &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
xen_bind_pirq_msi_to_irq(struct pci_dev * dev,struct msi_desc * msidesc,int pirq,int nvec,const char * name,domid_t domid)1103 int 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 + i);
1117 if (!info) {
1118 ret = -ENOMEM;
1119 goto error_irq;
1120 }
1121
1122 irq_set_chip_and_handler_name(irq + i, &xen_pirq_chip, handle_edge_irq, name);
1123
1124 ret = xen_irq_info_pirq_setup(info, 0, pirq + i, 0, domid,
1125 i == 0 ? 0 : PIRQ_MSI_GROUP);
1126 if (ret < 0)
1127 goto error_irq;
1128 }
1129
1130 ret = irq_set_msi_desc(irq, msidesc);
1131 if (ret < 0)
1132 goto error_irq;
1133 out:
1134 mutex_unlock(&irq_mapping_update_lock);
1135 return irq;
1136
1137 error_irq:
1138 while (nvec--) {
1139 info = info_for_irq(irq + nvec);
1140 __unbind_from_irq(info, irq + nvec);
1141 }
1142 mutex_unlock(&irq_mapping_update_lock);
1143 return ret;
1144 }
1145 #endif
1146
xen_destroy_irq(int irq)1147 int 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, &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
1179 out:
1180 mutex_unlock(&irq_mapping_update_lock);
1181 return rc;
1182 }
1183
xen_pirq_from_irq(unsigned irq)1184 int xen_pirq_from_irq(unsigned irq)
1185 {
1186 struct irq_info *info = info_for_irq(irq);
1187
1188 return pirq_from_irq(info);
1189 }
1190 EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
1191
bind_evtchn_to_irq_chip(evtchn_port_t evtchn,struct irq_chip * chip,struct xenbus_device * dev)1192 static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip,
1193 struct xenbus_device *dev)
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(info->irq, chip,
1211 handle_edge_irq, "event");
1212
1213 ret = xen_irq_info_evtchn_setup(info, evtchn, dev);
1214 if (ret < 0) {
1215 __unbind_from_irq(info, 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, 0, false);
1226 } else if (!WARN_ON(info->type != IRQT_EVTCHN)) {
1227 info->refcnt++;
1228 }
1229
1230 ret = info->irq;
1231
1232 out:
1233 mutex_unlock(&irq_mapping_update_lock);
1234
1235 return ret;
1236 }
1237
bind_evtchn_to_irq(evtchn_port_t evtchn)1238 int bind_evtchn_to_irq(evtchn_port_t evtchn)
1239 {
1240 return bind_evtchn_to_irq_chip(evtchn, &xen_dynamic_chip, NULL);
1241 }
1242 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
1243
bind_evtchn_to_irq_lateeoi(evtchn_port_t evtchn)1244 int bind_evtchn_to_irq_lateeoi(evtchn_port_t evtchn)
1245 {
1246 return bind_evtchn_to_irq_chip(evtchn, &xen_lateeoi_chip, NULL);
1247 }
1248 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq_lateeoi);
1249
bind_ipi_to_irq(unsigned int ipi,unsigned int cpu)1250 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
1251 {
1252 struct evtchn_bind_ipi bind_ipi;
1253 evtchn_port_t evtchn;
1254 struct irq_info *info;
1255 int ret;
1256
1257 mutex_lock(&irq_mapping_update_lock);
1258
1259 ret = per_cpu(ipi_to_irq, cpu)[ipi];
1260
1261 if (ret == -1) {
1262 info = xen_allocate_irq_dynamic();
1263 if (!info)
1264 goto out;
1265
1266 irq_set_chip_and_handler_name(info->irq, &xen_percpu_chip,
1267 handle_percpu_irq, "ipi");
1268
1269 bind_ipi.vcpu = xen_vcpu_nr(cpu);
1270 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1271 &bind_ipi) != 0)
1272 BUG();
1273 evtchn = bind_ipi.port;
1274
1275 ret = xen_irq_info_ipi_setup(info, cpu, evtchn, ipi);
1276 if (ret < 0) {
1277 __unbind_from_irq(info, info->irq);
1278 goto out;
1279 }
1280 /*
1281 * Force the affinity mask to the target CPU so proc shows
1282 * the correct target.
1283 */
1284 bind_evtchn_to_cpu(info, cpu, true);
1285 ret = info->irq;
1286 } else {
1287 info = info_for_irq(ret);
1288 WARN_ON(info == NULL || info->type != IRQT_IPI);
1289 }
1290
1291 out:
1292 mutex_unlock(&irq_mapping_update_lock);
1293 return ret;
1294 }
1295
bind_interdomain_evtchn_to_irq_chip(struct xenbus_device * dev,evtchn_port_t remote_port,struct irq_chip * chip)1296 static int bind_interdomain_evtchn_to_irq_chip(struct xenbus_device *dev,
1297 evtchn_port_t remote_port,
1298 struct irq_chip *chip)
1299 {
1300 struct evtchn_bind_interdomain bind_interdomain;
1301 int err;
1302
1303 bind_interdomain.remote_dom = dev->otherend_id;
1304 bind_interdomain.remote_port = remote_port;
1305
1306 err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
1307 &bind_interdomain);
1308
1309 return err ? : bind_evtchn_to_irq_chip(bind_interdomain.local_port,
1310 chip, dev);
1311 }
1312
bind_interdomain_evtchn_to_irq_lateeoi(struct xenbus_device * dev,evtchn_port_t remote_port)1313 int bind_interdomain_evtchn_to_irq_lateeoi(struct xenbus_device *dev,
1314 evtchn_port_t remote_port)
1315 {
1316 return bind_interdomain_evtchn_to_irq_chip(dev, remote_port,
1317 &xen_lateeoi_chip);
1318 }
1319 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq_lateeoi);
1320
find_virq(unsigned int virq,unsigned int cpu,evtchn_port_t * evtchn)1321 static int find_virq(unsigned int virq, unsigned int cpu, evtchn_port_t *evtchn)
1322 {
1323 struct evtchn_status status;
1324 evtchn_port_t port;
1325 int rc = -ENOENT;
1326
1327 memset(&status, 0, sizeof(status));
1328 for (port = 0; port < xen_evtchn_max_channels(); port++) {
1329 status.dom = DOMID_SELF;
1330 status.port = port;
1331 rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status);
1332 if (rc < 0)
1333 continue;
1334 if (status.status != EVTCHNSTAT_virq)
1335 continue;
1336 if (status.u.virq == virq && status.vcpu == xen_vcpu_nr(cpu)) {
1337 *evtchn = port;
1338 break;
1339 }
1340 }
1341 return rc;
1342 }
1343
1344 /**
1345 * xen_evtchn_nr_channels - number of usable event channel ports
1346 *
1347 * This may be less than the maximum supported by the current
1348 * hypervisor ABI. Use xen_evtchn_max_channels() for the maximum
1349 * supported.
1350 */
xen_evtchn_nr_channels(void)1351 unsigned xen_evtchn_nr_channels(void)
1352 {
1353 return evtchn_ops->nr_channels();
1354 }
1355 EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
1356
bind_virq_to_irq(unsigned int virq,unsigned int cpu,bool percpu)1357 int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
1358 {
1359 struct evtchn_bind_virq bind_virq;
1360 evtchn_port_t evtchn = 0;
1361 struct irq_info *info;
1362 int ret;
1363
1364 mutex_lock(&irq_mapping_update_lock);
1365
1366 ret = per_cpu(virq_to_irq, cpu)[virq];
1367
1368 if (ret == -1) {
1369 info = xen_allocate_irq_dynamic();
1370 if (!info)
1371 goto out;
1372
1373 if (percpu)
1374 irq_set_chip_and_handler_name(info->irq, &xen_percpu_chip,
1375 handle_percpu_irq, "virq");
1376 else
1377 irq_set_chip_and_handler_name(info->irq, &xen_dynamic_chip,
1378 handle_edge_irq, "virq");
1379
1380 bind_virq.virq = virq;
1381 bind_virq.vcpu = xen_vcpu_nr(cpu);
1382 ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1383 &bind_virq);
1384 if (ret == 0)
1385 evtchn = bind_virq.port;
1386 else {
1387 if (ret == -EEXIST)
1388 ret = find_virq(virq, cpu, &evtchn);
1389 BUG_ON(ret < 0);
1390 }
1391
1392 ret = xen_irq_info_virq_setup(info, cpu, evtchn, virq);
1393 if (ret < 0) {
1394 __unbind_from_irq(info, info->irq);
1395 goto out;
1396 }
1397
1398 /*
1399 * Force the affinity mask for percpu interrupts so proc
1400 * shows the correct target.
1401 */
1402 bind_evtchn_to_cpu(info, cpu, percpu);
1403 ret = info->irq;
1404 } else {
1405 info = info_for_irq(ret);
1406 WARN_ON(info == NULL || info->type != IRQT_VIRQ);
1407 }
1408
1409 out:
1410 mutex_unlock(&irq_mapping_update_lock);
1411
1412 return ret;
1413 }
1414
unbind_from_irq(unsigned int irq)1415 static void unbind_from_irq(unsigned int irq)
1416 {
1417 struct irq_info *info;
1418
1419 mutex_lock(&irq_mapping_update_lock);
1420 info = info_for_irq(irq);
1421 __unbind_from_irq(info, irq);
1422 mutex_unlock(&irq_mapping_update_lock);
1423 }
1424
bind_evtchn_to_irqhandler_chip(evtchn_port_t evtchn,irq_handler_t handler,unsigned long irqflags,const char * devname,void * dev_id,struct irq_chip * chip)1425 static int bind_evtchn_to_irqhandler_chip(evtchn_port_t evtchn,
1426 irq_handler_t handler,
1427 unsigned long irqflags,
1428 const char *devname, void *dev_id,
1429 struct irq_chip *chip)
1430 {
1431 int irq, retval;
1432
1433 irq = bind_evtchn_to_irq_chip(evtchn, chip, NULL);
1434 if (irq < 0)
1435 return irq;
1436 retval = request_irq(irq, handler, irqflags, devname, dev_id);
1437 if (retval != 0) {
1438 unbind_from_irq(irq);
1439 return retval;
1440 }
1441
1442 return irq;
1443 }
1444
bind_evtchn_to_irqhandler(evtchn_port_t evtchn,irq_handler_t handler,unsigned long irqflags,const char * devname,void * dev_id)1445 int bind_evtchn_to_irqhandler(evtchn_port_t evtchn,
1446 irq_handler_t handler,
1447 unsigned long irqflags,
1448 const char *devname, void *dev_id)
1449 {
1450 return bind_evtchn_to_irqhandler_chip(evtchn, handler, irqflags,
1451 devname, dev_id,
1452 &xen_dynamic_chip);
1453 }
1454 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
1455
bind_evtchn_to_irqhandler_lateeoi(evtchn_port_t evtchn,irq_handler_t handler,unsigned long irqflags,const char * devname,void * dev_id)1456 int bind_evtchn_to_irqhandler_lateeoi(evtchn_port_t evtchn,
1457 irq_handler_t handler,
1458 unsigned long irqflags,
1459 const char *devname, void *dev_id)
1460 {
1461 return bind_evtchn_to_irqhandler_chip(evtchn, handler, irqflags,
1462 devname, dev_id,
1463 &xen_lateeoi_chip);
1464 }
1465 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler_lateeoi);
1466
bind_interdomain_evtchn_to_irqhandler_chip(struct xenbus_device * dev,evtchn_port_t remote_port,irq_handler_t handler,unsigned long irqflags,const char * devname,void * dev_id,struct irq_chip * chip)1467 static int bind_interdomain_evtchn_to_irqhandler_chip(
1468 struct xenbus_device *dev, evtchn_port_t remote_port,
1469 irq_handler_t handler, unsigned long irqflags,
1470 const char *devname, void *dev_id, struct irq_chip *chip)
1471 {
1472 int irq, retval;
1473
1474 irq = bind_interdomain_evtchn_to_irq_chip(dev, remote_port, chip);
1475 if (irq < 0)
1476 return irq;
1477
1478 retval = request_irq(irq, handler, irqflags, devname, dev_id);
1479 if (retval != 0) {
1480 unbind_from_irq(irq);
1481 return retval;
1482 }
1483
1484 return irq;
1485 }
1486
bind_interdomain_evtchn_to_irqhandler_lateeoi(struct xenbus_device * dev,evtchn_port_t remote_port,irq_handler_t handler,unsigned long irqflags,const char * devname,void * dev_id)1487 int bind_interdomain_evtchn_to_irqhandler_lateeoi(struct xenbus_device *dev,
1488 evtchn_port_t remote_port,
1489 irq_handler_t handler,
1490 unsigned long irqflags,
1491 const char *devname,
1492 void *dev_id)
1493 {
1494 return bind_interdomain_evtchn_to_irqhandler_chip(dev,
1495 remote_port, handler, irqflags, devname,
1496 dev_id, &xen_lateeoi_chip);
1497 }
1498 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler_lateeoi);
1499
bind_virq_to_irqhandler(unsigned int virq,unsigned int cpu,irq_handler_t handler,unsigned long irqflags,const char * devname,void * dev_id)1500 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
1501 irq_handler_t handler,
1502 unsigned long irqflags, const char *devname, void *dev_id)
1503 {
1504 int irq, retval;
1505
1506 irq = bind_virq_to_irq(virq, cpu, irqflags & IRQF_PERCPU);
1507 if (irq < 0)
1508 return irq;
1509 retval = request_irq(irq, handler, irqflags, devname, dev_id);
1510 if (retval != 0) {
1511 unbind_from_irq(irq);
1512 return retval;
1513 }
1514
1515 return irq;
1516 }
1517 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
1518
bind_ipi_to_irqhandler(enum ipi_vector ipi,unsigned int cpu,irq_handler_t handler,unsigned long irqflags,const char * devname,void * dev_id)1519 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
1520 unsigned int cpu,
1521 irq_handler_t handler,
1522 unsigned long irqflags,
1523 const char *devname,
1524 void *dev_id)
1525 {
1526 int irq, retval;
1527
1528 irq = bind_ipi_to_irq(ipi, cpu);
1529 if (irq < 0)
1530 return irq;
1531
1532 irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME | IRQF_EARLY_RESUME;
1533 retval = request_irq(irq, handler, irqflags, devname, dev_id);
1534 if (retval != 0) {
1535 unbind_from_irq(irq);
1536 return retval;
1537 }
1538
1539 return irq;
1540 }
1541
unbind_from_irqhandler(unsigned int irq,void * dev_id)1542 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
1543 {
1544 struct irq_info *info = info_for_irq(irq);
1545
1546 if (WARN_ON(!info))
1547 return;
1548 free_irq(irq, dev_id);
1549 unbind_from_irq(irq);
1550 }
1551 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
1552
1553 /**
1554 * xen_set_irq_priority() - set an event channel priority.
1555 * @irq:irq bound to an event channel.
1556 * @priority: priority between XEN_IRQ_PRIORITY_MAX and XEN_IRQ_PRIORITY_MIN.
1557 */
xen_set_irq_priority(unsigned irq,unsigned priority)1558 int xen_set_irq_priority(unsigned irq, unsigned priority)
1559 {
1560 struct evtchn_set_priority set_priority;
1561
1562 set_priority.port = evtchn_from_irq(irq);
1563 set_priority.priority = priority;
1564
1565 return HYPERVISOR_event_channel_op(EVTCHNOP_set_priority,
1566 &set_priority);
1567 }
1568 EXPORT_SYMBOL_GPL(xen_set_irq_priority);
1569
evtchn_make_refcounted(evtchn_port_t evtchn,bool is_static)1570 int evtchn_make_refcounted(evtchn_port_t evtchn, bool is_static)
1571 {
1572 struct irq_info *info = evtchn_to_info(evtchn);
1573
1574 if (!info)
1575 return -ENOENT;
1576
1577 WARN_ON(info->refcnt != -1);
1578
1579 info->refcnt = 1;
1580 info->is_static = is_static;
1581
1582 return 0;
1583 }
1584 EXPORT_SYMBOL_GPL(evtchn_make_refcounted);
1585
evtchn_get(evtchn_port_t evtchn)1586 int evtchn_get(evtchn_port_t evtchn)
1587 {
1588 struct irq_info *info;
1589 int err = -ENOENT;
1590
1591 if (evtchn >= xen_evtchn_max_channels())
1592 return -EINVAL;
1593
1594 mutex_lock(&irq_mapping_update_lock);
1595
1596 info = evtchn_to_info(evtchn);
1597
1598 if (!info)
1599 goto done;
1600
1601 err = -EINVAL;
1602 if (info->refcnt <= 0 || info->refcnt == SHRT_MAX)
1603 goto done;
1604
1605 info->refcnt++;
1606 err = 0;
1607 done:
1608 mutex_unlock(&irq_mapping_update_lock);
1609
1610 return err;
1611 }
1612 EXPORT_SYMBOL_GPL(evtchn_get);
1613
evtchn_put(evtchn_port_t evtchn)1614 void evtchn_put(evtchn_port_t evtchn)
1615 {
1616 struct irq_info *info = evtchn_to_info(evtchn);
1617
1618 if (WARN_ON(!info))
1619 return;
1620 unbind_from_irq(info->irq);
1621 }
1622 EXPORT_SYMBOL_GPL(evtchn_put);
1623
xen_send_IPI_one(unsigned int cpu,enum ipi_vector vector)1624 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
1625 {
1626 evtchn_port_t evtchn;
1627
1628 #ifdef CONFIG_X86
1629 if (unlikely(vector == XEN_NMI_VECTOR)) {
1630 int rc = HYPERVISOR_vcpu_op(VCPUOP_send_nmi, xen_vcpu_nr(cpu),
1631 NULL);
1632 if (rc < 0)
1633 printk(KERN_WARNING "Sending nmi to CPU%d failed (rc:%d)\n", cpu, rc);
1634 return;
1635 }
1636 #endif
1637 evtchn = per_cpu(ipi_to_evtchn, cpu)[vector];
1638 BUG_ON(evtchn == 0);
1639 notify_remote_via_evtchn(evtchn);
1640 }
1641
1642 struct evtchn_loop_ctrl {
1643 ktime_t timeout;
1644 unsigned count;
1645 bool defer_eoi;
1646 };
1647
handle_irq_for_port(evtchn_port_t port,struct evtchn_loop_ctrl * ctrl)1648 void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl)
1649 {
1650 struct irq_info *info = evtchn_to_info(port);
1651 struct xenbus_device *dev;
1652
1653 if (!info)
1654 return;
1655
1656 /*
1657 * Check for timeout every 256 events.
1658 * We are setting the timeout value only after the first 256
1659 * events in order to not hurt the common case of few loop
1660 * iterations. The 256 is basically an arbitrary value.
1661 *
1662 * In case we are hitting the timeout we need to defer all further
1663 * EOIs in order to ensure to leave the event handling loop rather
1664 * sooner than later.
1665 */
1666 if (!ctrl->defer_eoi && !(++ctrl->count & 0xff)) {
1667 ktime_t kt = ktime_get();
1668
1669 if (!ctrl->timeout) {
1670 kt = ktime_add_ms(kt,
1671 jiffies_to_msecs(event_loop_timeout));
1672 ctrl->timeout = kt;
1673 } else if (kt > ctrl->timeout) {
1674 ctrl->defer_eoi = true;
1675 }
1676 }
1677
1678 if (xchg_acquire(&info->is_active, 1))
1679 return;
1680
1681 dev = (info->type == IRQT_EVTCHN) ? info->u.interdomain : NULL;
1682 if (dev)
1683 atomic_inc(&dev->events);
1684
1685 if (ctrl->defer_eoi) {
1686 info->eoi_cpu = smp_processor_id();
1687 info->irq_epoch = __this_cpu_read(irq_epoch);
1688 info->eoi_time = get_jiffies_64() + event_eoi_delay;
1689 }
1690
1691 generic_handle_irq(info->irq);
1692 }
1693
xen_evtchn_do_upcall(void)1694 int xen_evtchn_do_upcall(void)
1695 {
1696 struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1697 int ret = vcpu_info->evtchn_upcall_pending ? IRQ_HANDLED : IRQ_NONE;
1698 int cpu = smp_processor_id();
1699 struct evtchn_loop_ctrl ctrl = { 0 };
1700
1701 /*
1702 * When closing an event channel the associated IRQ must not be freed
1703 * until all cpus have left the event handling loop. This is ensured
1704 * by taking the rcu_read_lock() while handling events, as freeing of
1705 * the IRQ is handled via queue_rcu_work() _after_ closing the event
1706 * channel.
1707 */
1708 rcu_read_lock();
1709
1710 do {
1711 vcpu_info->evtchn_upcall_pending = 0;
1712
1713 xen_evtchn_handle_events(cpu, &ctrl);
1714
1715 BUG_ON(!irqs_disabled());
1716
1717 virt_rmb(); /* Hypervisor can set upcall pending. */
1718
1719 } while (vcpu_info->evtchn_upcall_pending);
1720
1721 rcu_read_unlock();
1722
1723 /*
1724 * Increment irq_epoch only now to defer EOIs only for
1725 * xen_irq_lateeoi() invocations occurring from inside the loop
1726 * above.
1727 */
1728 __this_cpu_inc(irq_epoch);
1729
1730 return ret;
1731 }
1732 EXPORT_SYMBOL_GPL(xen_evtchn_do_upcall);
1733
1734 /* Rebind a new event channel to an existing irq. */
rebind_evtchn_irq(evtchn_port_t evtchn,int irq)1735 void rebind_evtchn_irq(evtchn_port_t evtchn, int irq)
1736 {
1737 struct irq_info *info = info_for_irq(irq);
1738
1739 if (WARN_ON(!info))
1740 return;
1741
1742 /* Make sure the irq is masked, since the new event channel
1743 will also be masked. */
1744 disable_irq(irq);
1745
1746 mutex_lock(&irq_mapping_update_lock);
1747
1748 /* After resume the irq<->evtchn mappings are all cleared out */
1749 BUG_ON(evtchn_to_info(evtchn));
1750 /* Expect irq to have been bound before,
1751 so there should be a proper type */
1752 BUG_ON(info->type == IRQT_UNBOUND);
1753
1754 info->irq = irq;
1755 (void)xen_irq_info_evtchn_setup(info, evtchn, NULL);
1756
1757 mutex_unlock(&irq_mapping_update_lock);
1758
1759 bind_evtchn_to_cpu(info, info->cpu, false);
1760
1761 /* Unmask the event channel. */
1762 enable_irq(irq);
1763 }
1764
1765 /* Rebind an evtchn so that it gets delivered to a specific cpu */
xen_rebind_evtchn_to_cpu(struct irq_info * info,unsigned int tcpu)1766 static int xen_rebind_evtchn_to_cpu(struct irq_info *info, unsigned int tcpu)
1767 {
1768 struct evtchn_bind_vcpu bind_vcpu;
1769 evtchn_port_t evtchn = info ? info->evtchn : 0;
1770
1771 if (!VALID_EVTCHN(evtchn))
1772 return -1;
1773
1774 if (!xen_support_evtchn_rebind())
1775 return -1;
1776
1777 /* Send future instances of this interrupt to other vcpu. */
1778 bind_vcpu.port = evtchn;
1779 bind_vcpu.vcpu = xen_vcpu_nr(tcpu);
1780
1781 /*
1782 * Mask the event while changing the VCPU binding to prevent
1783 * it being delivered on an unexpected VCPU.
1784 */
1785 do_mask(info, EVT_MASK_REASON_TEMPORARY);
1786
1787 /*
1788 * If this fails, it usually just indicates that we're dealing with a
1789 * virq or IPI channel, which don't actually need to be rebound. Ignore
1790 * it, but don't do the xenlinux-level rebind in that case.
1791 */
1792 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1793 bind_evtchn_to_cpu(info, tcpu, false);
1794
1795 do_unmask(info, EVT_MASK_REASON_TEMPORARY);
1796
1797 return 0;
1798 }
1799
1800 /*
1801 * Find the CPU within @dest mask which has the least number of channels
1802 * assigned. This is not precise as the per cpu counts can be modified
1803 * concurrently.
1804 */
select_target_cpu(const struct cpumask * dest)1805 static unsigned int select_target_cpu(const struct cpumask *dest)
1806 {
1807 unsigned int cpu, best_cpu = UINT_MAX, minch = UINT_MAX;
1808
1809 for_each_cpu_and(cpu, dest, cpu_online_mask) {
1810 unsigned int curch = atomic_read(&channels_on_cpu[cpu]);
1811
1812 if (curch < minch) {
1813 minch = curch;
1814 best_cpu = cpu;
1815 }
1816 }
1817
1818 /*
1819 * Catch the unlikely case that dest contains no online CPUs. Can't
1820 * recurse.
1821 */
1822 if (best_cpu == UINT_MAX)
1823 return select_target_cpu(cpu_online_mask);
1824
1825 return best_cpu;
1826 }
1827
set_affinity_irq(struct irq_data * data,const struct cpumask * dest,bool force)1828 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1829 bool force)
1830 {
1831 unsigned int tcpu = select_target_cpu(dest);
1832 int ret;
1833
1834 ret = xen_rebind_evtchn_to_cpu(info_for_irq(data->irq), tcpu);
1835 if (!ret)
1836 irq_data_update_effective_affinity(data, cpumask_of(tcpu));
1837
1838 return ret;
1839 }
1840
enable_dynirq(struct irq_data * data)1841 static void enable_dynirq(struct irq_data *data)
1842 {
1843 struct irq_info *info = info_for_irq(data->irq);
1844 evtchn_port_t evtchn = info ? info->evtchn : 0;
1845
1846 if (VALID_EVTCHN(evtchn))
1847 do_unmask(info, EVT_MASK_REASON_EXPLICIT);
1848 }
1849
do_ack_dynirq(struct irq_info * info)1850 static void do_ack_dynirq(struct irq_info *info)
1851 {
1852 evtchn_port_t evtchn = info->evtchn;
1853
1854 if (VALID_EVTCHN(evtchn))
1855 event_handler_exit(info);
1856 }
1857
ack_dynirq(struct irq_data * data)1858 static void ack_dynirq(struct irq_data *data)
1859 {
1860 struct irq_info *info = info_for_irq(data->irq);
1861
1862 if (info)
1863 do_ack_dynirq(info);
1864 }
1865
mask_ack_dynirq(struct irq_data * data)1866 static void mask_ack_dynirq(struct irq_data *data)
1867 {
1868 struct irq_info *info = info_for_irq(data->irq);
1869
1870 if (info) {
1871 do_disable_dynirq(info);
1872 do_ack_dynirq(info);
1873 }
1874 }
1875
lateeoi_ack_dynirq(struct irq_data * data)1876 static void lateeoi_ack_dynirq(struct irq_data *data)
1877 {
1878 struct irq_info *info = info_for_irq(data->irq);
1879 evtchn_port_t evtchn = info ? info->evtchn : 0;
1880
1881 if (VALID_EVTCHN(evtchn)) {
1882 do_mask(info, EVT_MASK_REASON_EOI_PENDING);
1883 /*
1884 * Don't call event_handler_exit().
1885 * Need to keep is_active non-zero in order to ignore re-raised
1886 * events after cpu affinity changes while a lateeoi is pending.
1887 */
1888 clear_evtchn(evtchn);
1889 }
1890 }
1891
lateeoi_mask_ack_dynirq(struct irq_data * data)1892 static void lateeoi_mask_ack_dynirq(struct irq_data *data)
1893 {
1894 struct irq_info *info = info_for_irq(data->irq);
1895 evtchn_port_t evtchn = info ? info->evtchn : 0;
1896
1897 if (VALID_EVTCHN(evtchn)) {
1898 do_mask(info, EVT_MASK_REASON_EXPLICIT);
1899 event_handler_exit(info);
1900 }
1901 }
1902
retrigger_dynirq(struct irq_data * data)1903 static int retrigger_dynirq(struct irq_data *data)
1904 {
1905 struct irq_info *info = info_for_irq(data->irq);
1906 evtchn_port_t evtchn = info ? info->evtchn : 0;
1907
1908 if (!VALID_EVTCHN(evtchn))
1909 return 0;
1910
1911 do_mask(info, EVT_MASK_REASON_TEMPORARY);
1912 set_evtchn(evtchn);
1913 do_unmask(info, EVT_MASK_REASON_TEMPORARY);
1914
1915 return 1;
1916 }
1917
restore_pirqs(void)1918 static void restore_pirqs(void)
1919 {
1920 int pirq, rc, irq, gsi;
1921 struct physdev_map_pirq map_irq;
1922 struct irq_info *info;
1923
1924 list_for_each_entry(info, &xen_irq_list_head, list) {
1925 if (info->type != IRQT_PIRQ)
1926 continue;
1927
1928 pirq = info->u.pirq.pirq;
1929 gsi = info->u.pirq.gsi;
1930 irq = info->irq;
1931
1932 /* save/restore of PT devices doesn't work, so at this point the
1933 * only devices present are GSI based emulated devices */
1934 if (!gsi)
1935 continue;
1936
1937 map_irq.domid = DOMID_SELF;
1938 map_irq.type = MAP_PIRQ_TYPE_GSI;
1939 map_irq.index = gsi;
1940 map_irq.pirq = pirq;
1941
1942 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1943 if (rc) {
1944 pr_warn("xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1945 gsi, irq, pirq, rc);
1946 xen_free_irq(info);
1947 continue;
1948 }
1949
1950 printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1951
1952 __startup_pirq(info);
1953 }
1954 }
1955
restore_cpu_virqs(unsigned int cpu)1956 static void restore_cpu_virqs(unsigned int cpu)
1957 {
1958 struct evtchn_bind_virq bind_virq;
1959 evtchn_port_t evtchn;
1960 struct irq_info *info;
1961 int virq, irq;
1962
1963 for (virq = 0; virq < NR_VIRQS; virq++) {
1964 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1965 continue;
1966 info = info_for_irq(irq);
1967
1968 BUG_ON(virq_from_irq(info) != virq);
1969
1970 /* Get a new binding from Xen. */
1971 bind_virq.virq = virq;
1972 bind_virq.vcpu = xen_vcpu_nr(cpu);
1973 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1974 &bind_virq) != 0)
1975 BUG();
1976 evtchn = bind_virq.port;
1977
1978 /* Record the new mapping. */
1979 xen_irq_info_virq_setup(info, cpu, evtchn, virq);
1980 /* The affinity mask is still valid */
1981 bind_evtchn_to_cpu(info, cpu, false);
1982 }
1983 }
1984
restore_cpu_ipis(unsigned int cpu)1985 static void restore_cpu_ipis(unsigned int cpu)
1986 {
1987 struct evtchn_bind_ipi bind_ipi;
1988 evtchn_port_t evtchn;
1989 struct irq_info *info;
1990 int ipi, irq;
1991
1992 for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1993 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1994 continue;
1995 info = info_for_irq(irq);
1996
1997 BUG_ON(ipi_from_irq(info) != ipi);
1998
1999 /* Get a new binding from Xen. */
2000 bind_ipi.vcpu = xen_vcpu_nr(cpu);
2001 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
2002 &bind_ipi) != 0)
2003 BUG();
2004 evtchn = bind_ipi.port;
2005
2006 /* Record the new mapping. */
2007 xen_irq_info_ipi_setup(info, cpu, evtchn, ipi);
2008 /* The affinity mask is still valid */
2009 bind_evtchn_to_cpu(info, cpu, false);
2010 }
2011 }
2012
2013 /* Clear an irq's pending state, in preparation for polling on it */
xen_clear_irq_pending(int irq)2014 void xen_clear_irq_pending(int irq)
2015 {
2016 struct irq_info *info = info_for_irq(irq);
2017 evtchn_port_t evtchn = info ? info->evtchn : 0;
2018
2019 if (VALID_EVTCHN(evtchn))
2020 event_handler_exit(info);
2021 }
2022 EXPORT_SYMBOL(xen_clear_irq_pending);
2023
xen_test_irq_pending(int irq)2024 bool xen_test_irq_pending(int irq)
2025 {
2026 evtchn_port_t evtchn = evtchn_from_irq(irq);
2027 bool ret = false;
2028
2029 if (VALID_EVTCHN(evtchn))
2030 ret = test_evtchn(evtchn);
2031
2032 return ret;
2033 }
2034
2035 /* Poll waiting for an irq to become pending with timeout. In the usual case,
2036 * the irq will be disabled so it won't deliver an interrupt. */
xen_poll_irq_timeout(int irq,u64 timeout)2037 void xen_poll_irq_timeout(int irq, u64 timeout)
2038 {
2039 evtchn_port_t evtchn = evtchn_from_irq(irq);
2040
2041 if (VALID_EVTCHN(evtchn)) {
2042 struct sched_poll poll;
2043
2044 poll.nr_ports = 1;
2045 poll.timeout = timeout;
2046 set_xen_guest_handle(poll.ports, &evtchn);
2047
2048 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
2049 BUG();
2050 }
2051 }
2052 EXPORT_SYMBOL(xen_poll_irq_timeout);
2053 /* Poll waiting for an irq to become pending. In the usual case, the
2054 * irq will be disabled so it won't deliver an interrupt. */
xen_poll_irq(int irq)2055 void xen_poll_irq(int irq)
2056 {
2057 xen_poll_irq_timeout(irq, 0 /* no timeout */);
2058 }
2059
2060 /* Check whether the IRQ line is shared with other guests. */
xen_test_irq_shared(int irq)2061 int xen_test_irq_shared(int irq)
2062 {
2063 struct irq_info *info = info_for_irq(irq);
2064 struct physdev_irq_status_query irq_status;
2065
2066 if (WARN_ON(!info))
2067 return -ENOENT;
2068
2069 irq_status.irq = info->u.pirq.pirq;
2070
2071 if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
2072 return 0;
2073 return !(irq_status.flags & XENIRQSTAT_shared);
2074 }
2075 EXPORT_SYMBOL_GPL(xen_test_irq_shared);
2076
xen_irq_resume(void)2077 void xen_irq_resume(void)
2078 {
2079 unsigned int cpu;
2080 struct irq_info *info;
2081
2082 /* New event-channel space is not 'live' yet. */
2083 xen_evtchn_resume();
2084
2085 /* No IRQ <-> event-channel mappings. */
2086 list_for_each_entry(info, &xen_irq_list_head, list) {
2087 /* Zap event-channel binding */
2088 info->evtchn = 0;
2089 /* Adjust accounting */
2090 channels_on_cpu_dec(info);
2091 }
2092
2093 clear_evtchn_to_irq_all();
2094
2095 for_each_possible_cpu(cpu) {
2096 restore_cpu_virqs(cpu);
2097 restore_cpu_ipis(cpu);
2098 }
2099
2100 restore_pirqs();
2101 }
2102
2103 static struct irq_chip xen_dynamic_chip __read_mostly = {
2104 .name = "xen-dyn",
2105
2106 .irq_disable = disable_dynirq,
2107 .irq_mask = disable_dynirq,
2108 .irq_unmask = enable_dynirq,
2109
2110 .irq_ack = ack_dynirq,
2111 .irq_mask_ack = mask_ack_dynirq,
2112
2113 .irq_set_affinity = set_affinity_irq,
2114 .irq_retrigger = retrigger_dynirq,
2115 };
2116
2117 static struct irq_chip xen_lateeoi_chip __read_mostly = {
2118 /* The chip name needs to contain "xen-dyn" for irqbalance to work. */
2119 .name = "xen-dyn-lateeoi",
2120
2121 .irq_disable = disable_dynirq,
2122 .irq_mask = disable_dynirq,
2123 .irq_unmask = enable_dynirq,
2124
2125 .irq_ack = lateeoi_ack_dynirq,
2126 .irq_mask_ack = lateeoi_mask_ack_dynirq,
2127
2128 .irq_set_affinity = set_affinity_irq,
2129 .irq_retrigger = retrigger_dynirq,
2130 };
2131
2132 static struct irq_chip xen_pirq_chip __read_mostly = {
2133 .name = "xen-pirq",
2134
2135 .irq_startup = startup_pirq,
2136 .irq_shutdown = shutdown_pirq,
2137 .irq_enable = enable_pirq,
2138 .irq_disable = disable_pirq,
2139
2140 .irq_mask = disable_dynirq,
2141 .irq_unmask = enable_dynirq,
2142
2143 .irq_ack = eoi_pirq,
2144 .irq_eoi = eoi_pirq,
2145 .irq_mask_ack = mask_ack_pirq,
2146
2147 .irq_set_affinity = set_affinity_irq,
2148
2149 .irq_retrigger = retrigger_dynirq,
2150 };
2151
2152 static struct irq_chip xen_percpu_chip __read_mostly = {
2153 .name = "xen-percpu",
2154
2155 .irq_disable = disable_dynirq,
2156 .irq_mask = disable_dynirq,
2157 .irq_unmask = enable_dynirq,
2158
2159 .irq_ack = ack_dynirq,
2160 };
2161
2162 #ifdef CONFIG_X86
2163 #ifdef CONFIG_XEN_PVHVM
2164 /* Vector callbacks are better than PCI interrupts to receive event
2165 * channel notifications because we can receive vector callbacks on any
2166 * vcpu and we don't need PCI support or APIC interactions. */
xen_setup_callback_vector(void)2167 void xen_setup_callback_vector(void)
2168 {
2169 uint64_t callback_via;
2170
2171 if (xen_have_vector_callback) {
2172 callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
2173 if (xen_set_callback_via(callback_via)) {
2174 pr_err("Request for Xen HVM callback vector failed\n");
2175 xen_have_vector_callback = false;
2176 }
2177 }
2178 }
2179
2180 /*
2181 * Setup per-vCPU vector-type callbacks. If this setup is unavailable,
2182 * fallback to the global vector-type callback.
2183 */
xen_init_setup_upcall_vector(void)2184 static __init void xen_init_setup_upcall_vector(void)
2185 {
2186 if (!xen_have_vector_callback)
2187 return;
2188
2189 if ((cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_UPCALL_VECTOR) &&
2190 !xen_set_upcall_vector(0))
2191 xen_percpu_upcall = true;
2192 else if (xen_feature(XENFEAT_hvm_callback_vector))
2193 xen_setup_callback_vector();
2194 else
2195 xen_have_vector_callback = false;
2196 }
2197
xen_set_upcall_vector(unsigned int cpu)2198 int xen_set_upcall_vector(unsigned int cpu)
2199 {
2200 int rc;
2201 xen_hvm_evtchn_upcall_vector_t op = {
2202 .vector = HYPERVISOR_CALLBACK_VECTOR,
2203 .vcpu = per_cpu(xen_vcpu_id, cpu),
2204 };
2205
2206 rc = HYPERVISOR_hvm_op(HVMOP_set_evtchn_upcall_vector, &op);
2207 if (rc)
2208 return rc;
2209
2210 /* Trick toolstack to think we are enlightened. */
2211 if (!cpu)
2212 rc = xen_set_callback_via(1);
2213
2214 return rc;
2215 }
2216
xen_alloc_callback_vector(void)2217 static __init void xen_alloc_callback_vector(void)
2218 {
2219 if (!xen_have_vector_callback)
2220 return;
2221
2222 pr_info("Xen HVM callback vector for event delivery is enabled\n");
2223 alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_xen_hvm_callback);
2224 }
2225 #else
xen_setup_callback_vector(void)2226 void xen_setup_callback_vector(void) {}
xen_init_setup_upcall_vector(void)2227 static inline void xen_init_setup_upcall_vector(void) {}
xen_set_upcall_vector(unsigned int cpu)2228 int xen_set_upcall_vector(unsigned int cpu) {}
xen_alloc_callback_vector(void)2229 static inline void xen_alloc_callback_vector(void) {}
2230 #endif /* CONFIG_XEN_PVHVM */
2231 #endif /* CONFIG_X86 */
2232
2233 bool xen_fifo_events = true;
2234 module_param_named(fifo_events, xen_fifo_events, bool, 0);
2235
xen_evtchn_cpu_prepare(unsigned int cpu)2236 static int xen_evtchn_cpu_prepare(unsigned int cpu)
2237 {
2238 int ret = 0;
2239
2240 xen_cpu_init_eoi(cpu);
2241
2242 if (evtchn_ops->percpu_init)
2243 ret = evtchn_ops->percpu_init(cpu);
2244
2245 return ret;
2246 }
2247
xen_evtchn_cpu_dead(unsigned int cpu)2248 static int xen_evtchn_cpu_dead(unsigned int cpu)
2249 {
2250 int ret = 0;
2251
2252 if (evtchn_ops->percpu_deinit)
2253 ret = evtchn_ops->percpu_deinit(cpu);
2254
2255 return ret;
2256 }
2257
xen_init_IRQ(void)2258 void __init xen_init_IRQ(void)
2259 {
2260 int ret = -EINVAL;
2261 evtchn_port_t evtchn;
2262
2263 if (xen_fifo_events)
2264 ret = xen_evtchn_fifo_init();
2265 if (ret < 0) {
2266 xen_evtchn_2l_init();
2267 xen_fifo_events = false;
2268 }
2269
2270 xen_cpu_init_eoi(smp_processor_id());
2271
2272 cpuhp_setup_state_nocalls(CPUHP_XEN_EVTCHN_PREPARE,
2273 "xen/evtchn:prepare",
2274 xen_evtchn_cpu_prepare, xen_evtchn_cpu_dead);
2275
2276 evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()),
2277 sizeof(*evtchn_to_irq), GFP_KERNEL);
2278 BUG_ON(!evtchn_to_irq);
2279
2280 /* No event channels are 'live' right now. */
2281 for (evtchn = 0; evtchn < xen_evtchn_nr_channels(); evtchn++)
2282 mask_evtchn(evtchn);
2283
2284 pirq_needs_eoi = pirq_needs_eoi_flag;
2285
2286 #ifdef CONFIG_X86
2287 if (xen_pv_domain()) {
2288 if (xen_initial_domain())
2289 pci_xen_initial_domain();
2290 }
2291 xen_init_setup_upcall_vector();
2292 xen_alloc_callback_vector();
2293
2294
2295 if (xen_hvm_domain()) {
2296 native_init_IRQ();
2297 /* pci_xen_hvm_init must be called after native_init_IRQ so that
2298 * __acpi_register_gsi can point at the right function */
2299 pci_xen_hvm_init();
2300 } else {
2301 int rc;
2302 struct physdev_pirq_eoi_gmfn eoi_gmfn;
2303
2304 pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
2305 eoi_gmfn.gmfn = virt_to_gfn(pirq_eoi_map);
2306 rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn);
2307 if (rc != 0) {
2308 free_page((unsigned long) pirq_eoi_map);
2309 pirq_eoi_map = NULL;
2310 } else
2311 pirq_needs_eoi = pirq_check_eoi_map;
2312 }
2313 #endif
2314 }
2315