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authorIsaku Yamahata <yamahata@valinux.co.jp>2008-04-02 13:53:55 -0400
committerIngo Molnar <mingo@elte.hu>2008-04-24 17:57:32 -0400
commite04d0d0767a9c272d3c7300fb7a5221c5e3a71eb (patch)
tree41316aa05a218fcce5d619c11a57242c4f488d55 /arch/x86/xen/events.c
parentaf711cda4f94b5fddcdc5eb4134387ae026e3171 (diff)
xen: move events.c to drivers/xen for IA64/Xen support
move arch/x86/xen/events.c undedr drivers/xen to share codes with x86 and ia64. And minor adjustment to compile. ia64/xen also uses events.c Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com> Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/xen/events.c')
-rw-r--r--arch/x86/xen/events.c658
1 files changed, 0 insertions, 658 deletions
diff --git a/arch/x86/xen/events.c b/arch/x86/xen/events.c
deleted file mode 100644
index 85bac298b3cb..000000000000
--- a/arch/x86/xen/events.c
+++ /dev/null
@@ -1,658 +0,0 @@
1/*
2 * Xen event channels
3 *
4 * Xen models interrupts with abstract event channels. Because each
5 * domain gets 1024 event channels, but NR_IRQ is not that large, we
6 * must dynamically map irqs<->event channels. The event channels
7 * interface with the rest of the kernel by defining a xen interrupt
8 * chip. When an event is recieved, it is mapped to an irq and sent
9 * through the normal interrupt processing path.
10 *
11 * There are four kinds of events which can be mapped to an event
12 * channel:
13 *
14 * 1. Inter-domain notifications. This includes all the virtual
15 * device events, since they're driven by front-ends in another domain
16 * (typically dom0).
17 * 2. VIRQs, typically used for timers. These are per-cpu events.
18 * 3. IPIs.
19 * 4. Hardware interrupts. Not supported at present.
20 *
21 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
22 */
23
24#include <linux/linkage.h>
25#include <linux/interrupt.h>
26#include <linux/irq.h>
27#include <linux/module.h>
28#include <linux/string.h>
29
30#include <asm/ptrace.h>
31#include <asm/irq.h>
32#include <asm/sync_bitops.h>
33#include <asm/xen/hypercall.h>
34#include <asm/xen/hypervisor.h>
35
36#include <xen/events.h>
37#include <xen/interface/xen.h>
38#include <xen/interface/event_channel.h>
39
40#include "xen-ops.h"
41
42/*
43 * This lock protects updates to the following mapping and reference-count
44 * arrays. The lock does not need to be acquired to read the mapping tables.
45 */
46static DEFINE_SPINLOCK(irq_mapping_update_lock);
47
48/* IRQ <-> VIRQ mapping. */
49static DEFINE_PER_CPU(int, virq_to_irq[NR_VIRQS]) = {[0 ... NR_VIRQS-1] = -1};
50
51/* IRQ <-> IPI mapping */
52static DEFINE_PER_CPU(int, ipi_to_irq[XEN_NR_IPIS]) = {[0 ... XEN_NR_IPIS-1] = -1};
53
54/* Packed IRQ information: binding type, sub-type index, and event channel. */
55struct packed_irq
56{
57 unsigned short evtchn;
58 unsigned char index;
59 unsigned char type;
60};
61
62static struct packed_irq irq_info[NR_IRQS];
63
64/* Binding types. */
65enum {
66 IRQT_UNBOUND,
67 IRQT_PIRQ,
68 IRQT_VIRQ,
69 IRQT_IPI,
70 IRQT_EVTCHN
71};
72
73/* Convenient shorthand for packed representation of an unbound IRQ. */
74#define IRQ_UNBOUND mk_irq_info(IRQT_UNBOUND, 0, 0)
75
76static int evtchn_to_irq[NR_EVENT_CHANNELS] = {
77 [0 ... NR_EVENT_CHANNELS-1] = -1
78};
79static unsigned long cpu_evtchn_mask[NR_CPUS][NR_EVENT_CHANNELS/BITS_PER_LONG];
80static u8 cpu_evtchn[NR_EVENT_CHANNELS];
81
82/* Reference counts for bindings to IRQs. */
83static int irq_bindcount[NR_IRQS];
84
85/* Xen will never allocate port zero for any purpose. */
86#define VALID_EVTCHN(chn) ((chn) != 0)
87
88/*
89 * Force a proper event-channel callback from Xen after clearing the
90 * callback mask. We do this in a very simple manner, by making a call
91 * down into Xen. The pending flag will be checked by Xen on return.
92 */
93void force_evtchn_callback(void)
94{
95 (void)HYPERVISOR_xen_version(0, NULL);
96}
97EXPORT_SYMBOL_GPL(force_evtchn_callback);
98
99static struct irq_chip xen_dynamic_chip;
100
101/* Constructor for packed IRQ information. */
102static inline struct packed_irq mk_irq_info(u32 type, u32 index, u32 evtchn)
103{
104 return (struct packed_irq) { evtchn, index, type };
105}
106
107/*
108 * Accessors for packed IRQ information.
109 */
110static inline unsigned int evtchn_from_irq(int irq)
111{
112 return irq_info[irq].evtchn;
113}
114
115static inline unsigned int index_from_irq(int irq)
116{
117 return irq_info[irq].index;
118}
119
120static inline unsigned int type_from_irq(int irq)
121{
122 return irq_info[irq].type;
123}
124
125static inline unsigned long active_evtchns(unsigned int cpu,
126 struct shared_info *sh,
127 unsigned int idx)
128{
129 return (sh->evtchn_pending[idx] &
130 cpu_evtchn_mask[cpu][idx] &
131 ~sh->evtchn_mask[idx]);
132}
133
134static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
135{
136 int irq = evtchn_to_irq[chn];
137
138 BUG_ON(irq == -1);
139#ifdef CONFIG_SMP
140 irq_desc[irq].affinity = cpumask_of_cpu(cpu);
141#endif
142
143 __clear_bit(chn, cpu_evtchn_mask[cpu_evtchn[chn]]);
144 __set_bit(chn, cpu_evtchn_mask[cpu]);
145
146 cpu_evtchn[chn] = cpu;
147}
148
149static void init_evtchn_cpu_bindings(void)
150{
151#ifdef CONFIG_SMP
152 int i;
153 /* By default all event channels notify CPU#0. */
154 for (i = 0; i < NR_IRQS; i++)
155 irq_desc[i].affinity = cpumask_of_cpu(0);
156#endif
157
158 memset(cpu_evtchn, 0, sizeof(cpu_evtchn));
159 memset(cpu_evtchn_mask[0], ~0, sizeof(cpu_evtchn_mask[0]));
160}
161
162static inline unsigned int cpu_from_evtchn(unsigned int evtchn)
163{
164 return cpu_evtchn[evtchn];
165}
166
167static inline void clear_evtchn(int port)
168{
169 struct shared_info *s = HYPERVISOR_shared_info;
170 sync_clear_bit(port, &s->evtchn_pending[0]);
171}
172
173static inline void set_evtchn(int port)
174{
175 struct shared_info *s = HYPERVISOR_shared_info;
176 sync_set_bit(port, &s->evtchn_pending[0]);
177}
178
179
180/**
181 * notify_remote_via_irq - send event to remote end of event channel via irq
182 * @irq: irq of event channel to send event to
183 *
184 * Unlike notify_remote_via_evtchn(), this is safe to use across
185 * save/restore. Notifications on a broken connection are silently
186 * dropped.
187 */
188void notify_remote_via_irq(int irq)
189{
190 int evtchn = evtchn_from_irq(irq);
191
192 if (VALID_EVTCHN(evtchn))
193 notify_remote_via_evtchn(evtchn);
194}
195EXPORT_SYMBOL_GPL(notify_remote_via_irq);
196
197static void mask_evtchn(int port)
198{
199 struct shared_info *s = HYPERVISOR_shared_info;
200 sync_set_bit(port, &s->evtchn_mask[0]);
201}
202
203static void unmask_evtchn(int port)
204{
205 struct shared_info *s = HYPERVISOR_shared_info;
206 unsigned int cpu = get_cpu();
207
208 BUG_ON(!irqs_disabled());
209
210 /* Slow path (hypercall) if this is a non-local port. */
211 if (unlikely(cpu != cpu_from_evtchn(port))) {
212 struct evtchn_unmask unmask = { .port = port };
213 (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
214 } else {
215 struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
216
217 sync_clear_bit(port, &s->evtchn_mask[0]);
218
219 /*
220 * The following is basically the equivalent of
221 * 'hw_resend_irq'. Just like a real IO-APIC we 'lose
222 * the interrupt edge' if the channel is masked.
223 */
224 if (sync_test_bit(port, &s->evtchn_pending[0]) &&
225 !sync_test_and_set_bit(port / BITS_PER_LONG,
226 &vcpu_info->evtchn_pending_sel))
227 vcpu_info->evtchn_upcall_pending = 1;
228 }
229
230 put_cpu();
231}
232
233static int find_unbound_irq(void)
234{
235 int irq;
236
237 /* Only allocate from dynirq range */
238 for (irq = 0; irq < NR_IRQS; irq++)
239 if (irq_bindcount[irq] == 0)
240 break;
241
242 if (irq == NR_IRQS)
243 panic("No available IRQ to bind to: increase NR_IRQS!\n");
244
245 return irq;
246}
247
248int bind_evtchn_to_irq(unsigned int evtchn)
249{
250 int irq;
251
252 spin_lock(&irq_mapping_update_lock);
253
254 irq = evtchn_to_irq[evtchn];
255
256 if (irq == -1) {
257 irq = find_unbound_irq();
258
259 dynamic_irq_init(irq);
260 set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
261 handle_level_irq, "event");
262
263 evtchn_to_irq[evtchn] = irq;
264 irq_info[irq] = mk_irq_info(IRQT_EVTCHN, 0, evtchn);
265 }
266
267 irq_bindcount[irq]++;
268
269 spin_unlock(&irq_mapping_update_lock);
270
271 return irq;
272}
273EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
274
275static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
276{
277 struct evtchn_bind_ipi bind_ipi;
278 int evtchn, irq;
279
280 spin_lock(&irq_mapping_update_lock);
281
282 irq = per_cpu(ipi_to_irq, cpu)[ipi];
283 if (irq == -1) {
284 irq = find_unbound_irq();
285 if (irq < 0)
286 goto out;
287
288 dynamic_irq_init(irq);
289 set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
290 handle_level_irq, "ipi");
291
292 bind_ipi.vcpu = cpu;
293 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
294 &bind_ipi) != 0)
295 BUG();
296 evtchn = bind_ipi.port;
297
298 evtchn_to_irq[evtchn] = irq;
299 irq_info[irq] = mk_irq_info(IRQT_IPI, ipi, evtchn);
300
301 per_cpu(ipi_to_irq, cpu)[ipi] = irq;
302
303 bind_evtchn_to_cpu(evtchn, cpu);
304 }
305
306 irq_bindcount[irq]++;
307
308 out:
309 spin_unlock(&irq_mapping_update_lock);
310 return irq;
311}
312
313
314static int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
315{
316 struct evtchn_bind_virq bind_virq;
317 int evtchn, irq;
318
319 spin_lock(&irq_mapping_update_lock);
320
321 irq = per_cpu(virq_to_irq, cpu)[virq];
322
323 if (irq == -1) {
324 bind_virq.virq = virq;
325 bind_virq.vcpu = cpu;
326 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
327 &bind_virq) != 0)
328 BUG();
329 evtchn = bind_virq.port;
330
331 irq = find_unbound_irq();
332
333 dynamic_irq_init(irq);
334 set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
335 handle_level_irq, "virq");
336
337 evtchn_to_irq[evtchn] = irq;
338 irq_info[irq] = mk_irq_info(IRQT_VIRQ, virq, evtchn);
339
340 per_cpu(virq_to_irq, cpu)[virq] = irq;
341
342 bind_evtchn_to_cpu(evtchn, cpu);
343 }
344
345 irq_bindcount[irq]++;
346
347 spin_unlock(&irq_mapping_update_lock);
348
349 return irq;
350}
351
352static void unbind_from_irq(unsigned int irq)
353{
354 struct evtchn_close close;
355 int evtchn = evtchn_from_irq(irq);
356
357 spin_lock(&irq_mapping_update_lock);
358
359 if (VALID_EVTCHN(evtchn) && (--irq_bindcount[irq] == 0)) {
360 close.port = evtchn;
361 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
362 BUG();
363
364 switch (type_from_irq(irq)) {
365 case IRQT_VIRQ:
366 per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
367 [index_from_irq(irq)] = -1;
368 break;
369 default:
370 break;
371 }
372
373 /* Closed ports are implicitly re-bound to VCPU0. */
374 bind_evtchn_to_cpu(evtchn, 0);
375
376 evtchn_to_irq[evtchn] = -1;
377 irq_info[irq] = IRQ_UNBOUND;
378
379 dynamic_irq_init(irq);
380 }
381
382 spin_unlock(&irq_mapping_update_lock);
383}
384
385int bind_evtchn_to_irqhandler(unsigned int evtchn,
386 irq_handler_t handler,
387 unsigned long irqflags,
388 const char *devname, void *dev_id)
389{
390 unsigned int irq;
391 int retval;
392
393 irq = bind_evtchn_to_irq(evtchn);
394 retval = request_irq(irq, handler, irqflags, devname, dev_id);
395 if (retval != 0) {
396 unbind_from_irq(irq);
397 return retval;
398 }
399
400 return irq;
401}
402EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
403
404int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
405 irq_handler_t handler,
406 unsigned long irqflags, const char *devname, void *dev_id)
407{
408 unsigned int irq;
409 int retval;
410
411 irq = bind_virq_to_irq(virq, cpu);
412 retval = request_irq(irq, handler, irqflags, devname, dev_id);
413 if (retval != 0) {
414 unbind_from_irq(irq);
415 return retval;
416 }
417
418 return irq;
419}
420EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
421
422int bind_ipi_to_irqhandler(enum ipi_vector ipi,
423 unsigned int cpu,
424 irq_handler_t handler,
425 unsigned long irqflags,
426 const char *devname,
427 void *dev_id)
428{
429 int irq, retval;
430
431 irq = bind_ipi_to_irq(ipi, cpu);
432 if (irq < 0)
433 return irq;
434
435 retval = request_irq(irq, handler, irqflags, devname, dev_id);
436 if (retval != 0) {
437 unbind_from_irq(irq);
438 return retval;
439 }
440
441 return irq;
442}
443
444void unbind_from_irqhandler(unsigned int irq, void *dev_id)
445{
446 free_irq(irq, dev_id);
447 unbind_from_irq(irq);
448}
449EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
450
451void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
452{
453 int irq = per_cpu(ipi_to_irq, cpu)[vector];
454 BUG_ON(irq < 0);
455 notify_remote_via_irq(irq);
456}
457
458irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
459{
460 struct shared_info *sh = HYPERVISOR_shared_info;
461 int cpu = smp_processor_id();
462 int i;
463 unsigned long flags;
464 static DEFINE_SPINLOCK(debug_lock);
465
466 spin_lock_irqsave(&debug_lock, flags);
467
468 printk("vcpu %d\n ", cpu);
469
470 for_each_online_cpu(i) {
471 struct vcpu_info *v = per_cpu(xen_vcpu, i);
472 printk("%d: masked=%d pending=%d event_sel %08lx\n ", i,
473 (get_irq_regs() && i == cpu) ? !(get_irq_regs()->flags & X86_EFLAGS_IF) : v->evtchn_upcall_mask,
474 v->evtchn_upcall_pending,
475 v->evtchn_pending_sel);
476 }
477 printk("pending:\n ");
478 for(i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
479 printk("%08lx%s", sh->evtchn_pending[i],
480 i % 8 == 0 ? "\n " : " ");
481 printk("\nmasks:\n ");
482 for(i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
483 printk("%08lx%s", sh->evtchn_mask[i],
484 i % 8 == 0 ? "\n " : " ");
485
486 printk("\nunmasked:\n ");
487 for(i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
488 printk("%08lx%s", sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
489 i % 8 == 0 ? "\n " : " ");
490
491 printk("\npending list:\n");
492 for(i = 0; i < NR_EVENT_CHANNELS; i++) {
493 if (sync_test_bit(i, sh->evtchn_pending)) {
494 printk(" %d: event %d -> irq %d\n",
495 cpu_evtchn[i], i,
496 evtchn_to_irq[i]);
497 }
498 }
499
500 spin_unlock_irqrestore(&debug_lock, flags);
501
502 return IRQ_HANDLED;
503}
504
505
506/*
507 * Search the CPUs pending events bitmasks. For each one found, map
508 * the event number to an irq, and feed it into do_IRQ() for
509 * handling.
510 *
511 * Xen uses a two-level bitmap to speed searching. The first level is
512 * a bitset of words which contain pending event bits. The second
513 * level is a bitset of pending events themselves.
514 */
515void xen_evtchn_do_upcall(struct pt_regs *regs)
516{
517 int cpu = get_cpu();
518 struct shared_info *s = HYPERVISOR_shared_info;
519 struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
520 static DEFINE_PER_CPU(unsigned, nesting_count);
521 unsigned count;
522
523 do {
524 unsigned long pending_words;
525
526 vcpu_info->evtchn_upcall_pending = 0;
527
528 if (__get_cpu_var(nesting_count)++)
529 goto out;
530
531 /* NB. No need for a barrier here -- XCHG is a barrier on x86. */
532 pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
533 while (pending_words != 0) {
534 unsigned long pending_bits;
535 int word_idx = __ffs(pending_words);
536 pending_words &= ~(1UL << word_idx);
537
538 while ((pending_bits = active_evtchns(cpu, s, word_idx)) != 0) {
539 int bit_idx = __ffs(pending_bits);
540 int port = (word_idx * BITS_PER_LONG) + bit_idx;
541 int irq = evtchn_to_irq[port];
542
543 if (irq != -1) {
544 regs->orig_ax = ~irq;
545 do_IRQ(regs);
546 }
547 }
548 }
549
550 BUG_ON(!irqs_disabled());
551
552 count = __get_cpu_var(nesting_count);
553 __get_cpu_var(nesting_count) = 0;
554 } while(count != 1);
555
556out:
557 put_cpu();
558}
559
560/* Rebind an evtchn so that it gets delivered to a specific cpu */
561static void rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
562{
563 struct evtchn_bind_vcpu bind_vcpu;
564 int evtchn = evtchn_from_irq(irq);
565
566 if (!VALID_EVTCHN(evtchn))
567 return;
568
569 /* Send future instances of this interrupt to other vcpu. */
570 bind_vcpu.port = evtchn;
571 bind_vcpu.vcpu = tcpu;
572
573 /*
574 * If this fails, it usually just indicates that we're dealing with a
575 * virq or IPI channel, which don't actually need to be rebound. Ignore
576 * it, but don't do the xenlinux-level rebind in that case.
577 */
578 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
579 bind_evtchn_to_cpu(evtchn, tcpu);
580}
581
582
583static void set_affinity_irq(unsigned irq, cpumask_t dest)
584{
585 unsigned tcpu = first_cpu(dest);
586 rebind_irq_to_cpu(irq, tcpu);
587}
588
589static void enable_dynirq(unsigned int irq)
590{
591 int evtchn = evtchn_from_irq(irq);
592
593 if (VALID_EVTCHN(evtchn))
594 unmask_evtchn(evtchn);
595}
596
597static void disable_dynirq(unsigned int irq)
598{
599 int evtchn = evtchn_from_irq(irq);
600
601 if (VALID_EVTCHN(evtchn))
602 mask_evtchn(evtchn);
603}
604
605static void ack_dynirq(unsigned int irq)
606{
607 int evtchn = evtchn_from_irq(irq);
608
609 move_native_irq(irq);
610
611 if (VALID_EVTCHN(evtchn))
612 clear_evtchn(evtchn);
613}
614
615static int retrigger_dynirq(unsigned int irq)
616{
617 int evtchn = evtchn_from_irq(irq);
618 struct shared_info *sh = HYPERVISOR_shared_info;
619 int ret = 0;
620
621 if (VALID_EVTCHN(evtchn)) {
622 int masked;
623
624 masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
625 sync_set_bit(evtchn, sh->evtchn_pending);
626 if (!masked)
627 unmask_evtchn(evtchn);
628 ret = 1;
629 }
630
631 return ret;
632}
633
634static struct irq_chip xen_dynamic_chip __read_mostly = {
635 .name = "xen-dyn",
636 .mask = disable_dynirq,
637 .unmask = enable_dynirq,
638 .ack = ack_dynirq,
639 .set_affinity = set_affinity_irq,
640 .retrigger = retrigger_dynirq,
641};
642
643void __init xen_init_IRQ(void)
644{
645 int i;
646
647 init_evtchn_cpu_bindings();
648
649 /* No event channels are 'live' right now. */
650 for (i = 0; i < NR_EVENT_CHANNELS; i++)
651 mask_evtchn(i);
652
653 /* Dynamic IRQ space is currently unbound. Zero the refcnts. */
654 for (i = 0; i < NR_IRQS; i++)
655 irq_bindcount[i] = 0;
656
657 irq_ctx_init(smp_processor_id());
658}
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