SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/xen/events.c

   1 /*
   2  * Xen event channels
   3  *
   4  * Xen models interrupts with abstract event channels.  Because each
   5  * domain gets 1024 event channels, but NR_IRQ is not that large, we
   6  * must dynamically map irqs<->event channels.  The event channels
   7  * interface with the rest of the kernel by defining a xen interrupt
   8  * chip.  When an event is recieved, it is mapped to an irq and sent
   9  * through the normal interrupt processing path.
  10  *
  11  * There are four kinds of events which can be mapped to an event
  12  * channel:
  13  *
  14  * 1. Inter-domain notifications.  This includes all the virtual
  15  *    device events, since they're driven by front-ends in another domain
  16  *    (typically dom0).
  17  * 2. VIRQs, typically used for timers.  These are per-cpu events.
  18  * 3. IPIs.
  19  * 4. 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/xen-ops.h>
  37 #include <xen/events.h>
  38 #include <xen/interface/xen.h>
  39 #include <xen/interface/event_channel.h>
  40
  41 /*
  42  * This lock protects updates to the following mapping and reference-count
  43  * arrays. The lock does not need to be acquired to read the mapping tables.
  44  */
  45 static DEFINE_SPINLOCK(irq_mapping_update_lock);
  46
  47 /* IRQ <-> VIRQ mapping. */
  48 static DEFINE_PER_CPU(int, virq_to_irq[NR_VIRQS]) = {[0 ... NR_VIRQS-1] = -1};
  49
  50 /* IRQ <-> IPI mapping */
  51 static DEFINE_PER_CPU(int, ipi_to_irq[XEN_NR_IPIS]) = {[0 ... XEN_NR_IPIS-1] = -1};
  52
  53 /* Packed IRQ information: binding type, sub-type index, and event channel. */
  54 struct packed_irq
  55 {
  56         unsigned short evtchn;
  57         unsigned char index;
  58         unsigned char type;
  59 };
  60
  61 static struct packed_irq irq_info[NR_IRQS];
  62
  63 /* Binding types. */
  64 enum {
  65         IRQT_UNBOUND,
  66         IRQT_PIRQ,
  67         IRQT_VIRQ,
  68         IRQT_IPI,
  69         IRQT_EVTCHN
  70 };
  71
  72 /* Convenient shorthand for packed representation of an unbound IRQ. */
  73 #define IRQ_UNBOUND     mk_irq_info(IRQT_UNBOUND, 0, 0)
  74
  75 static int evtchn_to_irq[NR_EVENT_CHANNELS] = {
  76         [0 ... NR_EVENT_CHANNELS-1] = -1
  77 };
  78 static unsigned long cpu_evtchn_mask[NR_CPUS][NR_EVENT_CHANNELS/BITS_PER_LONG];
  79 static u8 cpu_evtchn[NR_EVENT_CHANNELS];
  80
  81 /* Reference counts for bindings to IRQs. */
  82 static int irq_bindcount[NR_IRQS];
  83
  84 /* Xen will never allocate port zero for any purpose. */
  85 #define VALID_EVTCHN(chn)       ((chn) != 0)
  86
  87 static struct irq_chip xen_dynamic_chip;
  88
  89 /* Constructor for packed IRQ information. */
  90 static inline struct packed_irq mk_irq_info(u32 type, u32 index, u32 evtchn)
  91 {
  92         return (struct packed_irq) { evtchn, index, type };
  93 }
  94
  95 /*
  96  * Accessors for packed IRQ information.
  97  */
  98 static inline unsigned int evtchn_from_irq(int irq)
  99 {
 100         return irq_info[irq].evtchn;
 101 }
 102
 103 static inline unsigned int index_from_irq(int irq)
 104 {
 105         return irq_info[irq].index;
 106 }
 107
 108 static inline unsigned int type_from_irq(int irq)
 109 {
 110         return irq_info[irq].type;
 111 }
 112
 113 static inline unsigned long active_evtchns(unsigned int cpu,
 114                                            struct shared_info *sh,
 115                                            unsigned int idx)
 116 {
 117         return (sh->evtchn_pending[idx] &
 118                 cpu_evtchn_mask[cpu][idx] &
 119                 ~sh->evtchn_mask[idx]);
 120 }
 121
 122 static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
 123 {
 124         int irq = evtchn_to_irq[chn];
 125
 126         BUG_ON(irq == -1);
 127 #ifdef CONFIG_SMP
 128         irq_to_desc(irq)->affinity = cpumask_of_cpu(cpu);
 129 #endif
 130
 131         __clear_bit(chn, cpu_evtchn_mask[cpu_evtchn[chn]]);
 132         __set_bit(chn, cpu_evtchn_mask[cpu]);
 133
 134         cpu_evtchn[chn] = cpu;
 135 }
 136
 137 static void init_evtchn_cpu_bindings(void)
 138 {
 139 #ifdef CONFIG_SMP
 140         struct irq_desc *desc;
 141         int i;
 142
 143         /* By default all event channels notify CPU#0. */
 144         for_each_irq_desc(i, desc) {
 145                 desc->affinity = cpumask_of_cpu(0);
 146         }
 147 #endif
 148
 149         memset(cpu_evtchn, 0, sizeof(cpu_evtchn));
 150         memset(cpu_evtchn_mask[0], ~0, sizeof(cpu_evtchn_mask[0]));
 151 }
 152
 153 static inline unsigned int cpu_from_evtchn(unsigned int evtchn)
 154 {
 155         return cpu_evtchn[evtchn];
 156 }
 157
 158 static inline void clear_evtchn(int port)
 159 {
 160         struct shared_info *s = HYPERVISOR_shared_info;
 161         sync_clear_bit(port, &s->evtchn_pending[0]);
 162 }
 163
 164 static inline void set_evtchn(int port)
 165 {
 166         struct shared_info *s = HYPERVISOR_shared_info;
 167         sync_set_bit(port, &s->evtchn_pending[0]);
 168 }
 169
 170 static inline int test_evtchn(int port)
 171 {
 172         struct shared_info *s = HYPERVISOR_shared_info;
 173         return sync_test_bit(port, &s->evtchn_pending[0]);
 174 }
 175
 176
 177 /**
 178  * notify_remote_via_irq - send event to remote end of event channel via irq
 179  * @irq: irq of event channel to send event to
 180  *
 181  * Unlike notify_remote_via_evtchn(), this is safe to use across
 182  * save/restore. Notifications on a broken connection are silently
 183  * dropped.
 184  */
 185 void notify_remote_via_irq(int irq)
 186 {
 187         int evtchn = evtchn_from_irq(irq);
 188
 189         if (VALID_EVTCHN(evtchn))
 190                 notify_remote_via_evtchn(evtchn);
 191 }
 192 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
 193
 194 static void mask_evtchn(int port)
 195 {
 196         struct shared_info *s = HYPERVISOR_shared_info;
 197         sync_set_bit(port, &s->evtchn_mask[0]);
 198 }
 199
 200 static void unmask_evtchn(int port)
 201 {
 202         struct shared_info *s = HYPERVISOR_shared_info;
 203         unsigned int cpu = get_cpu();
 204
 205         BUG_ON(!irqs_disabled());
 206
 207         /* Slow path (hypercall) if this is a non-local port. */
 208         if (unlikely(cpu != cpu_from_evtchn(port))) {
 209                 struct evtchn_unmask unmask = { .port = port };
 210                 (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
 211         } else {
 212                 struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
 213
 214                 sync_clear_bit(port, &s->evtchn_mask[0]);
 215
 216                 /*
 217                  * The following is basically the equivalent of
 218                  * 'hw_resend_irq'. Just like a real IO-APIC we 'lose
 219                  * the interrupt edge' if the channel is masked.
 220                  */
 221                 if (sync_test_bit(port, &s->evtchn_pending[0]) &&
 222                     !sync_test_and_set_bit(port / BITS_PER_LONG,
 223                                            &vcpu_info->evtchn_pending_sel))
 224                         vcpu_info->evtchn_upcall_pending = 1;
 225         }
 226
 227         put_cpu();
 228 }
 229
 230 static int find_unbound_irq(void)
 231 {
 232         int irq;
 233         struct irq_desc *desc;
 234
 235         /* Only allocate from dynirq range */
 236         for (irq = 0; irq < nr_irqs; irq++)
 237                 if (irq_bindcount[irq] == 0)
 238                         break;
 239
 240         if (irq == nr_irqs)
 241                 panic("No available IRQ to bind to: increase nr_irqs!\n");
 242
 243         desc = irq_to_desc_alloc_cpu(irq, 0);
 244         if (WARN_ON(desc == NULL))
 245                 return -1;
 246
 247         return irq;
 248 }
 249
 250 int bind_evtchn_to_irq(unsigned int evtchn)
 251 {
 252         int irq;
 253
 254         spin_lock(&irq_mapping_update_lock);
 255
 256         irq = evtchn_to_irq[evtchn];
 257
 258         if (irq == -1) {
 259                 irq = find_unbound_irq();
 260
 261                 dynamic_irq_init(irq);
 262                 set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
 263                                               handle_level_irq, "event");
 264
 265                 evtchn_to_irq[evtchn] = irq;
 266                 irq_info[irq] = mk_irq_info(IRQT_EVTCHN, 0, evtchn);
 267         }
 268
 269         irq_bindcount[irq]++;
 270
 271         spin_unlock(&irq_mapping_update_lock);
 272
 273         return irq;
 274 }
 275 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
 276
 277 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 278 {
 279         struct evtchn_bind_ipi bind_ipi;
 280         int evtchn, irq;
 281
 282         spin_lock(&irq_mapping_update_lock);
 283
 284         irq = per_cpu(ipi_to_irq, cpu)[ipi];
 285         if (irq == -1) {
 286                 irq = find_unbound_irq();
 287                 if (irq < 0)
 288                         goto out;
 289
 290                 dynamic_irq_init(irq);
 291                 set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
 292                                               handle_level_irq, "ipi");
 293
 294                 bind_ipi.vcpu = cpu;
 295                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
 296                                                 &bind_ipi) != 0)
 297                         BUG();
 298                 evtchn = bind_ipi.port;
 299
 300                 evtchn_to_irq[evtchn] = irq;
 301                 irq_info[irq] = mk_irq_info(IRQT_IPI, ipi, evtchn);
 302
 303                 per_cpu(ipi_to_irq, cpu)[ipi] = irq;
 304
 305                 bind_evtchn_to_cpu(evtchn, cpu);
 306         }
 307
 308         irq_bindcount[irq]++;
 309
 310  out:
 311         spin_unlock(&irq_mapping_update_lock);
 312         return irq;
 313 }
 314
 315
 316 static int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 317 {
 318         struct evtchn_bind_virq bind_virq;
 319         int evtchn, irq;
 320
 321         spin_lock(&irq_mapping_update_lock);
 322
 323         irq = per_cpu(virq_to_irq, cpu)[virq];
 324
 325         if (irq == -1) {
 326                 bind_virq.virq = virq;
 327                 bind_virq.vcpu = cpu;
 328                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
 329                                                 &bind_virq) != 0)
 330                         BUG();
 331                 evtchn = bind_virq.port;
 332
 333                 irq = find_unbound_irq();
 334
 335                 dynamic_irq_init(irq);
 336                 set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
 337                                               handle_level_irq, "virq");
 338
 339                 evtchn_to_irq[evtchn] = irq;
 340                 irq_info[irq] = mk_irq_info(IRQT_VIRQ, virq, evtchn);
 341
 342                 per_cpu(virq_to_irq, cpu)[virq] = irq;
 343
 344                 bind_evtchn_to_cpu(evtchn, cpu);
 345         }
 346
 347         irq_bindcount[irq]++;
 348
 349         spin_unlock(&irq_mapping_update_lock);
 350
 351         return irq;
 352 }
 353
 354 static void unbind_from_irq(unsigned int irq)
 355 {
 356         struct evtchn_close close;
 357         int evtchn = evtchn_from_irq(irq);
 358
 359         spin_lock(&irq_mapping_update_lock);
 360
 361         if ((--irq_bindcount[irq] == 0) && VALID_EVTCHN(evtchn)) {
 362                 close.port = evtchn;
 363                 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 364                         BUG();
 365
 366                 switch (type_from_irq(irq)) {
 367                 case IRQT_VIRQ:
 368                         per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
 369                                 [index_from_irq(irq)] = -1;
 370                         break;
 371                 case IRQT_IPI:
 372                         per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn))
 373                                 [index_from_irq(irq)] = -1;
 374                         break;
 375                 default:
 376                         break;
 377                 }
 378
 379                 /* Closed ports are implicitly re-bound to VCPU0. */
 380                 bind_evtchn_to_cpu(evtchn, 0);
 381
 382                 evtchn_to_irq[evtchn] = -1;
 383                 irq_info[irq] = IRQ_UNBOUND;
 384
 385                 dynamic_irq_cleanup(irq);
 386         }
 387
 388         spin_unlock(&irq_mapping_update_lock);
 389 }
 390
 391 int bind_evtchn_to_irqhandler(unsigned int evtchn,
 392                               irq_handler_t handler,
 393                               unsigned long irqflags,
 394                               const char *devname, void *dev_id)
 395 {
 396         unsigned int irq;
 397         int retval;
 398
 399         irq = bind_evtchn_to_irq(evtchn);
 400         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 401         if (retval != 0) {
 402                 unbind_from_irq(irq);
 403                 return retval;
 404         }
 405
 406         return irq;
 407 }
 408 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
 409
 410 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
 411                             irq_handler_t handler,
 412                             unsigned long irqflags, const char *devname, void *dev_id)
 413 {
 414         unsigned int irq;
 415         int retval;
 416
 417         irq = bind_virq_to_irq(virq, cpu);
 418         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 419         if (retval != 0) {
 420                 unbind_from_irq(irq);
 421                 return retval;
 422         }
 423
 424         return irq;
 425 }
 426 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
 427
 428 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
 429                            unsigned int cpu,
 430                            irq_handler_t handler,
 431                            unsigned long irqflags,
 432                            const char *devname,
 433                            void *dev_id)
 434 {
 435         int irq, retval;
 436
 437         irq = bind_ipi_to_irq(ipi, cpu);
 438         if (irq < 0)
 439                 return irq;
 440
 441         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 442         if (retval != 0) {
 443                 unbind_from_irq(irq);
 444                 return retval;
 445         }
 446
 447         return irq;
 448 }
 449
 450 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
 451 {
 452         free_irq(irq, dev_id);
 453         unbind_from_irq(irq);
 454 }
 455 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
 456
 457 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
 458 {
 459         int irq = per_cpu(ipi_to_irq, cpu)[vector];
 460         BUG_ON(irq < 0);
 461         notify_remote_via_irq(irq);
 462 }
 463
 464 irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
 465 {
 466         struct shared_info *sh = HYPERVISOR_shared_info;
 467         int cpu = smp_processor_id();
 468         int i;
 469         unsigned long flags;
 470         static DEFINE_SPINLOCK(debug_lock);
 471
 472         spin_lock_irqsave(&debug_lock, flags);
 473
 474         printk("vcpu %d\n  ", cpu);
 475
 476         for_each_online_cpu(i) {
 477                 struct vcpu_info *v = per_cpu(xen_vcpu, i);
 478                 printk("%d: masked=%d pending=%d event_sel %08lx\n  ", i,
 479                         (get_irq_regs() && i == cpu) ? xen_irqs_disabled(get_irq_regs()) : v->evtchn_upcall_mask,
 480                         v->evtchn_upcall_pending,
 481                         v->evtchn_pending_sel);
 482         }
 483         printk("pending:\n   ");
 484         for(i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
 485                 printk("%08lx%s", sh->evtchn_pending[i],
 486                         i % 8 == 0 ? "\n   " : " ");
 487         printk("\nmasks:\n   ");
 488         for(i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
 489                 printk("%08lx%s", sh->evtchn_mask[i],
 490                         i % 8 == 0 ? "\n   " : " ");
 491
 492         printk("\nunmasked:\n   ");
 493         for(i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
 494                 printk("%08lx%s", sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
 495                         i % 8 == 0 ? "\n   " : " ");
 496
 497         printk("\npending list:\n");
 498         for(i = 0; i < NR_EVENT_CHANNELS; i++) {
 499                 if (sync_test_bit(i, sh->evtchn_pending)) {
 500                         printk("  %d: event %d -> irq %d\n",
 501                                 cpu_evtchn[i], i,
 502                                 evtchn_to_irq[i]);
 503                 }
 504         }
 505
 506         spin_unlock_irqrestore(&debug_lock, flags);
 507
 508         return IRQ_HANDLED;
 509 }
 510
 511
 512 /*
 513  * Search the CPUs pending events bitmasks.  For each one found, map
 514  * the event number to an irq, and feed it into do_IRQ() for
 515  * handling.
 516  *
 517  * Xen uses a two-level bitmap to speed searching.  The first level is
 518  * a bitset of words which contain pending event bits.  The second
 519  * level is a bitset of pending events themselves.
 520  */
 521 void xen_evtchn_do_upcall(struct pt_regs *regs)
 522 {
 523         int cpu = get_cpu();
 524         struct shared_info *s = HYPERVISOR_shared_info;
 525         struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
 526         static DEFINE_PER_CPU(unsigned, nesting_count);
 527         unsigned count;
 528
 529         do {
 530                 unsigned long pending_words;
 531
 532                 vcpu_info->evtchn_upcall_pending = 0;
 533
 534                 if (__get_cpu_var(nesting_count)++)
 535                         goto out;
 536
 537 #ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
 538                 /* Clear master flag /before/ clearing selector flag. */
 539                 wmb();
 540 #endif
 541                 pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
 542                 while (pending_words != 0) {
 543                         unsigned long pending_bits;
 544                         int word_idx = __ffs(pending_words);
 545                         pending_words &= ~(1UL << word_idx);
 546
 547                         while ((pending_bits = active_evtchns(cpu, s, word_idx)) != 0) {
 548                                 int bit_idx = __ffs(pending_bits);
 549                                 int port = (word_idx * BITS_PER_LONG) + bit_idx;
 550                                 int irq = evtchn_to_irq[port];
 551
 552                                 if (irq != -1)
 553                                         xen_do_IRQ(irq, regs);
 554                         }
 555                 }
 556
 557                 BUG_ON(!irqs_disabled());
 558
 559                 count = __get_cpu_var(nesting_count);
 560                 __get_cpu_var(nesting_count) = 0;
 561         } while(count != 1);
 562
 563 out:
 564         put_cpu();
 565 }
 566
 567 /* Rebind a new event channel to an existing irq. */
 568 void rebind_evtchn_irq(int evtchn, int irq)
 569 {
 570         /* Make sure the irq is masked, since the new event channel
 571            will also be masked. */
 572         disable_irq(irq);
 573
 574         spin_lock(&irq_mapping_update_lock);
 575
 576         /* After resume the irq<->evtchn mappings are all cleared out */
 577         BUG_ON(evtchn_to_irq[evtchn] != -1);
 578         /* Expect irq to have been bound before,
 579            so the bindcount should be non-0 */
 580         BUG_ON(irq_bindcount[irq] == 0);
 581
 582         evtchn_to_irq[evtchn] = irq;
 583         irq_info[irq] = mk_irq_info(IRQT_EVTCHN, 0, evtchn);
 584
 585         spin_unlock(&irq_mapping_update_lock);
 586
 587         /* new event channels are always bound to cpu 0 */
 588         irq_set_affinity(irq, cpumask_of_cpu(0));
 589
 590         /* Unmask the event channel. */
 591         enable_irq(irq);
 592 }
 593
 594 /* Rebind an evtchn so that it gets delivered to a specific cpu */
 595 static void rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
 596 {
 597         struct evtchn_bind_vcpu bind_vcpu;
 598         int evtchn = evtchn_from_irq(irq);
 599
 600         if (!VALID_EVTCHN(evtchn))
 601                 return;
 602
 603         /* Send future instances of this interrupt to other vcpu. */
 604         bind_vcpu.port = evtchn;
 605         bind_vcpu.vcpu = tcpu;
 606
 607         /*
 608          * If this fails, it usually just indicates that we're dealing with a
 609          * virq or IPI channel, which don't actually need to be rebound. Ignore
 610          * it, but don't do the xenlinux-level rebind in that case.
 611          */
 612         if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
 613                 bind_evtchn_to_cpu(evtchn, tcpu);
 614 }
 615
 616
 617 static void set_affinity_irq(unsigned irq, cpumask_t dest)
 618 {
 619         unsigned tcpu = first_cpu(dest);
 620         rebind_irq_to_cpu(irq, tcpu);
 621 }
 622
 623 int resend_irq_on_evtchn(unsigned int irq)
 624 {
 625         int masked, evtchn = evtchn_from_irq(irq);
 626         struct shared_info *s = HYPERVISOR_shared_info;
 627
 628         if (!VALID_EVTCHN(evtchn))
 629                 return 1;
 630
 631         masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
 632         sync_set_bit(evtchn, s->evtchn_pending);
 633         if (!masked)
 634                 unmask_evtchn(evtchn);
 635
 636         return 1;
 637 }
 638
 639 static void enable_dynirq(unsigned int irq)
 640 {
 641         int evtchn = evtchn_from_irq(irq);
 642
 643         if (VALID_EVTCHN(evtchn))
 644                 unmask_evtchn(evtchn);
 645 }
 646
 647 static void disable_dynirq(unsigned int irq)
 648 {
 649         int evtchn = evtchn_from_irq(irq);
 650
 651         if (VALID_EVTCHN(evtchn))
 652                 mask_evtchn(evtchn);
 653 }
 654
 655 static void ack_dynirq(unsigned int irq)
 656 {
 657         int evtchn = evtchn_from_irq(irq);
 658
 659         move_native_irq(irq);
 660
 661         if (VALID_EVTCHN(evtchn))
 662                 clear_evtchn(evtchn);
 663 }
 664
 665 static int retrigger_dynirq(unsigned int irq)
 666 {
 667         int evtchn = evtchn_from_irq(irq);
 668         struct shared_info *sh = HYPERVISOR_shared_info;
 669         int ret = 0;
 670
 671         if (VALID_EVTCHN(evtchn)) {
 672                 int masked;
 673
 674                 masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
 675                 sync_set_bit(evtchn, sh->evtchn_pending);
 676                 if (!masked)
 677                         unmask_evtchn(evtchn);
 678                 ret = 1;
 679         }
 680
 681         return ret;
 682 }
 683
 684 static void restore_cpu_virqs(unsigned int cpu)
 685 {
 686         struct evtchn_bind_virq bind_virq;
 687         int virq, irq, evtchn;
 688
 689         for (virq = 0; virq < NR_VIRQS; virq++) {
 690                 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
 691                         continue;
 692
 693                 BUG_ON(irq_info[irq].type != IRQT_VIRQ);
 694                 BUG_ON(irq_info[irq].index != virq);
 695
 696                 /* Get a new binding from Xen. */
 697                 bind_virq.virq = virq;
 698                 bind_virq.vcpu = cpu;
 699                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
 700                                                 &bind_virq) != 0)
 701                         BUG();
 702                 evtchn = bind_virq.port;
 703
 704                 /* Record the new mapping. */
 705                 evtchn_to_irq[evtchn] = irq;
 706                 irq_info[irq] = mk_irq_info(IRQT_VIRQ, virq, evtchn);
 707                 bind_evtchn_to_cpu(evtchn, cpu);
 708
 709                 /* Ready for use. */
 710                 unmask_evtchn(evtchn);
 711         }
 712 }
 713
 714 static void restore_cpu_ipis(unsigned int cpu)
 715 {
 716         struct evtchn_bind_ipi bind_ipi;
 717         int ipi, irq, evtchn;
 718
 719         for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
 720                 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
 721                         continue;
 722
 723                 BUG_ON(irq_info[irq].type != IRQT_IPI);
 724                 BUG_ON(irq_info[irq].index != ipi);
 725
 726                 /* Get a new binding from Xen. */
 727                 bind_ipi.vcpu = cpu;
 728                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
 729                                                 &bind_ipi) != 0)
 730                         BUG();
 731                 evtchn = bind_ipi.port;
 732
 733                 /* Record the new mapping. */
 734                 evtchn_to_irq[evtchn] = irq;
 735                 irq_info[irq] = mk_irq_info(IRQT_IPI, ipi, evtchn);
 736                 bind_evtchn_to_cpu(evtchn, cpu);
 737
 738                 /* Ready for use. */
 739                 unmask_evtchn(evtchn);
 740
 741         }
 742 }
 743
 744 /* Clear an irq's pending state, in preparation for polling on it */
 745 void xen_clear_irq_pending(int irq)
 746 {
 747         int evtchn = evtchn_from_irq(irq);
 748
 749         if (VALID_EVTCHN(evtchn))
 750                 clear_evtchn(evtchn);
 751 }
 752
 753 void xen_set_irq_pending(int irq)
 754 {
 755         int evtchn = evtchn_from_irq(irq);
 756
 757         if (VALID_EVTCHN(evtchn))
 758                 set_evtchn(evtchn);
 759 }
 760
 761 bool xen_test_irq_pending(int irq)
 762 {
 763         int evtchn = evtchn_from_irq(irq);
 764         bool ret = false;
 765
 766         if (VALID_EVTCHN(evtchn))
 767                 ret = test_evtchn(evtchn);
 768
 769         return ret;
 770 }
 771
 772 /* Poll waiting for an irq to become pending.  In the usual case, the
 773    irq will be disabled so it won't deliver an interrupt. */
 774 void xen_poll_irq(int irq)
 775 {
 776         evtchn_port_t evtchn = evtchn_from_irq(irq);
 777
 778         if (VALID_EVTCHN(evtchn)) {
 779                 struct sched_poll poll;
 780
 781                 poll.nr_ports = 1;
 782                 poll.timeout = 0;
 783                 set_xen_guest_handle(poll.ports, &evtchn);
 784
 785                 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
 786                         BUG();
 787         }
 788 }
 789
 790 void xen_irq_resume(void)
 791 {
 792         unsigned int cpu, irq, evtchn;
 793
 794         init_evtchn_cpu_bindings();
 795
 796         /* New event-channel space is not 'live' yet. */
 797         for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
 798                 mask_evtchn(evtchn);
 799
 800         /* No IRQ <-> event-channel mappings. */
 801         for (irq = 0; irq < nr_irqs; irq++)
 802                 irq_info[irq].evtchn = 0; /* zap event-channel binding */
 803
 804         for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
 805                 evtchn_to_irq[evtchn] = -1;
 806
 807         for_each_possible_cpu(cpu) {
 808                 restore_cpu_virqs(cpu);
 809                 restore_cpu_ipis(cpu);
 810         }
 811 }
 812
 813 static struct irq_chip xen_dynamic_chip __read_mostly = {
 814         .name           = "xen-dyn",
 815         .mask           = disable_dynirq,
 816         .unmask         = enable_dynirq,
 817         .ack            = ack_dynirq,
 818         .set_affinity   = set_affinity_irq,
 819         .retrigger      = retrigger_dynirq,
 820 };
 821
 822 void __init xen_init_IRQ(void)
 823 {
 824         int i;
 825
 826         init_evtchn_cpu_bindings();
 827
 828         /* No event channels are 'live' right now. */
 829         for (i = 0; i < NR_EVENT_CHANNELS; i++)
 830                 mask_evtchn(i);
 831
 832         /* Dynamic IRQ space is currently unbound. Zero the refcnts. */
 833         for (i = 0; i < nr_irqs; i++)
 834                 irq_bindcount[i] = 0;
 835
 836         irq_ctx_init(smp_processor_id());
 837 }