linux/drivers/xen/events.c
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   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 received, it is mapped to an irq and sent
   9 * through the normal interrupt processing path.
  10 *
  11 * There are four kinds of events which can be mapped to an event
  12 * channel:
  13 *
  14 * 1. Inter-domain notifications.  This includes all the virtual
  15 *    device events, since they're driven by front-ends in another domain
  16 *    (typically dom0).
  17 * 2. VIRQs, typically used for timers.  These are per-cpu events.
  18 * 3. IPIs.
  19 * 4. PIRQs - Hardware interrupts.
  20 *
  21 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
  22 */
  23
  24#include <linux/linkage.h>
  25#include <linux/interrupt.h>
  26#include <linux/irq.h>
  27#include <linux/module.h>
  28#include <linux/string.h>
  29#include <linux/bootmem.h>
  30#include <linux/slab.h>
  31#include <linux/irqnr.h>
  32#include <linux/pci.h>
  33
  34#include <asm/desc.h>
  35#include <asm/ptrace.h>
  36#include <asm/irq.h>
  37#include <asm/idle.h>
  38#include <asm/io_apic.h>
  39#include <asm/sync_bitops.h>
  40#include <asm/xen/page.h>
  41#include <asm/xen/pci.h>
  42#include <asm/xen/hypercall.h>
  43#include <asm/xen/hypervisor.h>
  44
  45#include <xen/xen.h>
  46#include <xen/hvm.h>
  47#include <xen/xen-ops.h>
  48#include <xen/events.h>
  49#include <xen/interface/xen.h>
  50#include <xen/interface/event_channel.h>
  51#include <xen/interface/hvm/hvm_op.h>
  52#include <xen/interface/hvm/params.h>
  53
  54/*
  55 * This lock protects updates to the following mapping and reference-count
  56 * arrays. The lock does not need to be acquired to read the mapping tables.
  57 */
  58static DEFINE_MUTEX(irq_mapping_update_lock);
  59
  60static LIST_HEAD(xen_irq_list_head);
  61
  62/* IRQ <-> VIRQ mapping. */
  63static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
  64
  65/* IRQ <-> IPI mapping */
  66static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
  67
  68/* Interrupt types. */
  69enum xen_irq_type {
  70        IRQT_UNBOUND = 0,
  71        IRQT_PIRQ,
  72        IRQT_VIRQ,
  73        IRQT_IPI,
  74        IRQT_EVTCHN
  75};
  76
  77/*
  78 * Packed IRQ information:
  79 * type - enum xen_irq_type
  80 * event channel - irq->event channel mapping
  81 * cpu - cpu this event channel is bound to
  82 * index - type-specific information:
  83 *    PIRQ - vector, with MSB being "needs EIO", or physical IRQ of the HVM
  84 *           guest, or GSI (real passthrough IRQ) of the device.
  85 *    VIRQ - virq number
  86 *    IPI - IPI vector
  87 *    EVTCHN -
  88 */
  89struct irq_info {
  90        struct list_head list;
  91        int refcnt;
  92        enum xen_irq_type type; /* type */
  93        unsigned irq;
  94        unsigned short evtchn;  /* event channel */
  95        unsigned short cpu;     /* cpu bound */
  96
  97        union {
  98                unsigned short virq;
  99                enum ipi_vector ipi;
 100                struct {
 101                        unsigned short pirq;
 102                        unsigned short gsi;
 103                        unsigned char vector;
 104                        unsigned char flags;
 105                        uint16_t domid;
 106                } pirq;
 107        } u;
 108};
 109#define PIRQ_NEEDS_EOI  (1 << 0)
 110#define PIRQ_SHAREABLE  (1 << 1)
 111
 112static int *evtchn_to_irq;
 113static unsigned long *pirq_eoi_map;
 114static bool (*pirq_needs_eoi)(unsigned irq);
 115
 116static DEFINE_PER_CPU(unsigned long [NR_EVENT_CHANNELS/BITS_PER_LONG],
 117                      cpu_evtchn_mask);
 118
 119/* Xen will never allocate port zero for any purpose. */
 120#define VALID_EVTCHN(chn)       ((chn) != 0)
 121
 122static struct irq_chip xen_dynamic_chip;
 123static struct irq_chip xen_percpu_chip;
 124static struct irq_chip xen_pirq_chip;
 125static void enable_dynirq(struct irq_data *data);
 126static void disable_dynirq(struct irq_data *data);
 127
 128/* Get info for IRQ */
 129static struct irq_info *info_for_irq(unsigned irq)
 130{
 131        return irq_get_handler_data(irq);
 132}
 133
 134/* Constructors for packed IRQ information. */
 135static void xen_irq_info_common_init(struct irq_info *info,
 136                                     unsigned irq,
 137                                     enum xen_irq_type type,
 138                                     unsigned short evtchn,
 139                                     unsigned short cpu)
 140{
 141
 142        BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
 143
 144        info->type = type;
 145        info->irq = irq;
 146        info->evtchn = evtchn;
 147        info->cpu = cpu;
 148
 149        evtchn_to_irq[evtchn] = irq;
 150}
 151
 152static void xen_irq_info_evtchn_init(unsigned irq,
 153                                     unsigned short evtchn)
 154{
 155        struct irq_info *info = info_for_irq(irq);
 156
 157        xen_irq_info_common_init(info, irq, IRQT_EVTCHN, evtchn, 0);
 158}
 159
 160static void xen_irq_info_ipi_init(unsigned cpu,
 161                                  unsigned irq,
 162                                  unsigned short evtchn,
 163                                  enum ipi_vector ipi)
 164{
 165        struct irq_info *info = info_for_irq(irq);
 166
 167        xen_irq_info_common_init(info, irq, IRQT_IPI, evtchn, 0);
 168
 169        info->u.ipi = ipi;
 170
 171        per_cpu(ipi_to_irq, cpu)[ipi] = irq;
 172}
 173
 174static void xen_irq_info_virq_init(unsigned cpu,
 175                                   unsigned irq,
 176                                   unsigned short evtchn,
 177                                   unsigned short virq)
 178{
 179        struct irq_info *info = info_for_irq(irq);
 180
 181        xen_irq_info_common_init(info, irq, IRQT_VIRQ, evtchn, 0);
 182
 183        info->u.virq = virq;
 184
 185        per_cpu(virq_to_irq, cpu)[virq] = irq;
 186}
 187
 188static void xen_irq_info_pirq_init(unsigned irq,
 189                                   unsigned short evtchn,
 190                                   unsigned short pirq,
 191                                   unsigned short gsi,
 192                                   unsigned short vector,
 193                                   uint16_t domid,
 194                                   unsigned char flags)
 195{
 196        struct irq_info *info = info_for_irq(irq);
 197
 198        xen_irq_info_common_init(info, irq, IRQT_PIRQ, evtchn, 0);
 199
 200        info->u.pirq.pirq = pirq;
 201        info->u.pirq.gsi = gsi;
 202        info->u.pirq.vector = vector;
 203        info->u.pirq.domid = domid;
 204        info->u.pirq.flags = flags;
 205}
 206
 207/*
 208 * Accessors for packed IRQ information.
 209 */
 210static unsigned int evtchn_from_irq(unsigned irq)
 211{
 212        if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))
 213                return 0;
 214
 215        return info_for_irq(irq)->evtchn;
 216}
 217
 218unsigned irq_from_evtchn(unsigned int evtchn)
 219{
 220        return evtchn_to_irq[evtchn];
 221}
 222EXPORT_SYMBOL_GPL(irq_from_evtchn);
 223
 224static enum ipi_vector ipi_from_irq(unsigned irq)
 225{
 226        struct irq_info *info = info_for_irq(irq);
 227
 228        BUG_ON(info == NULL);
 229        BUG_ON(info->type != IRQT_IPI);
 230
 231        return info->u.ipi;
 232}
 233
 234static unsigned virq_from_irq(unsigned irq)
 235{
 236        struct irq_info *info = info_for_irq(irq);
 237
 238        BUG_ON(info == NULL);
 239        BUG_ON(info->type != IRQT_VIRQ);
 240
 241        return info->u.virq;
 242}
 243
 244static unsigned pirq_from_irq(unsigned irq)
 245{
 246        struct irq_info *info = info_for_irq(irq);
 247
 248        BUG_ON(info == NULL);
 249        BUG_ON(info->type != IRQT_PIRQ);
 250
 251        return info->u.pirq.pirq;
 252}
 253
 254static enum xen_irq_type type_from_irq(unsigned irq)
 255{
 256        return info_for_irq(irq)->type;
 257}
 258
 259static unsigned cpu_from_irq(unsigned irq)
 260{
 261        return info_for_irq(irq)->cpu;
 262}
 263
 264static unsigned int cpu_from_evtchn(unsigned int evtchn)
 265{
 266        int irq = evtchn_to_irq[evtchn];
 267        unsigned ret = 0;
 268
 269        if (irq != -1)
 270                ret = cpu_from_irq(irq);
 271
 272        return ret;
 273}
 274
 275static bool pirq_check_eoi_map(unsigned irq)
 276{
 277        return test_bit(pirq_from_irq(irq), pirq_eoi_map);
 278}
 279
 280static bool pirq_needs_eoi_flag(unsigned irq)
 281{
 282        struct irq_info *info = info_for_irq(irq);
 283        BUG_ON(info->type != IRQT_PIRQ);
 284
 285        return info->u.pirq.flags & PIRQ_NEEDS_EOI;
 286}
 287
 288static inline unsigned long active_evtchns(unsigned int cpu,
 289                                           struct shared_info *sh,
 290                                           unsigned int idx)
 291{
 292        return sh->evtchn_pending[idx] &
 293                per_cpu(cpu_evtchn_mask, cpu)[idx] &
 294                ~sh->evtchn_mask[idx];
 295}
 296
 297static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
 298{
 299        int irq = evtchn_to_irq[chn];
 300
 301        BUG_ON(irq == -1);
 302#ifdef CONFIG_SMP
 303        cpumask_copy(irq_to_desc(irq)->irq_data.affinity, cpumask_of(cpu));
 304#endif
 305
 306        clear_bit(chn, per_cpu(cpu_evtchn_mask, cpu_from_irq(irq)));
 307        set_bit(chn, per_cpu(cpu_evtchn_mask, cpu));
 308
 309        info_for_irq(irq)->cpu = cpu;
 310}
 311
 312static void init_evtchn_cpu_bindings(void)
 313{
 314        int i;
 315#ifdef CONFIG_SMP
 316        struct irq_info *info;
 317
 318        /* By default all event channels notify CPU#0. */
 319        list_for_each_entry(info, &xen_irq_list_head, list) {
 320                struct irq_desc *desc = irq_to_desc(info->irq);
 321                cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
 322        }
 323#endif
 324
 325        for_each_possible_cpu(i)
 326                memset(per_cpu(cpu_evtchn_mask, i),
 327                       (i == 0) ? ~0 : 0, sizeof(*per_cpu(cpu_evtchn_mask, i)));
 328}
 329
 330static inline void clear_evtchn(int port)
 331{
 332        struct shared_info *s = HYPERVISOR_shared_info;
 333        sync_clear_bit(port, &s->evtchn_pending[0]);
 334}
 335
 336static inline void set_evtchn(int port)
 337{
 338        struct shared_info *s = HYPERVISOR_shared_info;
 339        sync_set_bit(port, &s->evtchn_pending[0]);
 340}
 341
 342static inline int test_evtchn(int port)
 343{
 344        struct shared_info *s = HYPERVISOR_shared_info;
 345        return sync_test_bit(port, &s->evtchn_pending[0]);
 346}
 347
 348
 349/**
 350 * notify_remote_via_irq - send event to remote end of event channel via irq
 351 * @irq: irq of event channel to send event to
 352 *
 353 * Unlike notify_remote_via_evtchn(), this is safe to use across
 354 * save/restore. Notifications on a broken connection are silently
 355 * dropped.
 356 */
 357void notify_remote_via_irq(int irq)
 358{
 359        int evtchn = evtchn_from_irq(irq);
 360
 361        if (VALID_EVTCHN(evtchn))
 362                notify_remote_via_evtchn(evtchn);
 363}
 364EXPORT_SYMBOL_GPL(notify_remote_via_irq);
 365
 366static void mask_evtchn(int port)
 367{
 368        struct shared_info *s = HYPERVISOR_shared_info;
 369        sync_set_bit(port, &s->evtchn_mask[0]);
 370}
 371
 372static void unmask_evtchn(int port)
 373{
 374        struct shared_info *s = HYPERVISOR_shared_info;
 375        unsigned int cpu = get_cpu();
 376
 377        BUG_ON(!irqs_disabled());
 378
 379        /* Slow path (hypercall) if this is a non-local port. */
 380        if (unlikely(cpu != cpu_from_evtchn(port))) {
 381                struct evtchn_unmask unmask = { .port = port };
 382                (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
 383        } else {
 384                struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
 385
 386                sync_clear_bit(port, &s->evtchn_mask[0]);
 387
 388                /*
 389                 * The following is basically the equivalent of
 390                 * 'hw_resend_irq'. Just like a real IO-APIC we 'lose
 391                 * the interrupt edge' if the channel is masked.
 392                 */
 393                if (sync_test_bit(port, &s->evtchn_pending[0]) &&
 394                    !sync_test_and_set_bit(port / BITS_PER_LONG,
 395                                           &vcpu_info->evtchn_pending_sel))
 396                        vcpu_info->evtchn_upcall_pending = 1;
 397        }
 398
 399        put_cpu();
 400}
 401
 402static void xen_irq_init(unsigned irq)
 403{
 404        struct irq_info *info;
 405#ifdef CONFIG_SMP
 406        struct irq_desc *desc = irq_to_desc(irq);
 407
 408        /* By default all event channels notify CPU#0. */
 409        cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
 410#endif
 411
 412        info = kzalloc(sizeof(*info), GFP_KERNEL);
 413        if (info == NULL)
 414                panic("Unable to allocate metadata for IRQ%d\n", irq);
 415
 416        info->type = IRQT_UNBOUND;
 417        info->refcnt = -1;
 418
 419        irq_set_handler_data(irq, info);
 420
 421        list_add_tail(&info->list, &xen_irq_list_head);
 422}
 423
 424static int __must_check xen_allocate_irq_dynamic(void)
 425{
 426        int first = 0;
 427        int irq;
 428
 429#ifdef CONFIG_X86_IO_APIC
 430        /*
 431         * For an HVM guest or domain 0 which see "real" (emulated or
 432         * actual respectively) GSIs we allocate dynamic IRQs
 433         * e.g. those corresponding to event channels or MSIs
 434         * etc. from the range above those "real" GSIs to avoid
 435         * collisions.
 436         */
 437        if (xen_initial_domain() || xen_hvm_domain())
 438                first = get_nr_irqs_gsi();
 439#endif
 440
 441        irq = irq_alloc_desc_from(first, -1);
 442
 443        if (irq >= 0)
 444                xen_irq_init(irq);
 445
 446        return irq;
 447}
 448
 449static int __must_check xen_allocate_irq_gsi(unsigned gsi)
 450{
 451        int irq;
 452
 453        /*
 454         * A PV guest has no concept of a GSI (since it has no ACPI
 455         * nor access to/knowledge of the physical APICs). Therefore
 456         * all IRQs are dynamically allocated from the entire IRQ
 457         * space.
 458         */
 459        if (xen_pv_domain() && !xen_initial_domain())
 460                return xen_allocate_irq_dynamic();
 461
 462        /* Legacy IRQ descriptors are already allocated by the arch. */
 463        if (gsi < NR_IRQS_LEGACY)
 464                irq = gsi;
 465        else
 466                irq = irq_alloc_desc_at(gsi, -1);
 467
 468        xen_irq_init(irq);
 469
 470        return irq;
 471}
 472
 473static void xen_free_irq(unsigned irq)
 474{
 475        struct irq_info *info = irq_get_handler_data(irq);
 476
 477        list_del(&info->list);
 478
 479        irq_set_handler_data(irq, NULL);
 480
 481        WARN_ON(info->refcnt > 0);
 482
 483        kfree(info);
 484
 485        /* Legacy IRQ descriptors are managed by the arch. */
 486        if (irq < NR_IRQS_LEGACY)
 487                return;
 488
 489        irq_free_desc(irq);
 490}
 491
 492static void pirq_query_unmask(int irq)
 493{
 494        struct physdev_irq_status_query irq_status;
 495        struct irq_info *info = info_for_irq(irq);
 496
 497        BUG_ON(info->type != IRQT_PIRQ);
 498
 499        irq_status.irq = pirq_from_irq(irq);
 500        if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
 501                irq_status.flags = 0;
 502
 503        info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
 504        if (irq_status.flags & XENIRQSTAT_needs_eoi)
 505                info->u.pirq.flags |= PIRQ_NEEDS_EOI;
 506}
 507
 508static bool probing_irq(int irq)
 509{
 510        struct irq_desc *desc = irq_to_desc(irq);
 511
 512        return desc && desc->action == NULL;
 513}
 514
 515static void eoi_pirq(struct irq_data *data)
 516{
 517        int evtchn = evtchn_from_irq(data->irq);
 518        struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
 519        int rc = 0;
 520
 521        irq_move_irq(data);
 522
 523        if (VALID_EVTCHN(evtchn))
 524                clear_evtchn(evtchn);
 525
 526        if (pirq_needs_eoi(data->irq)) {
 527                rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
 528                WARN_ON(rc);
 529        }
 530}
 531
 532static void mask_ack_pirq(struct irq_data *data)
 533{
 534        disable_dynirq(data);
 535        eoi_pirq(data);
 536}
 537
 538static unsigned int __startup_pirq(unsigned int irq)
 539{
 540        struct evtchn_bind_pirq bind_pirq;
 541        struct irq_info *info = info_for_irq(irq);
 542        int evtchn = evtchn_from_irq(irq);
 543        int rc;
 544
 545        BUG_ON(info->type != IRQT_PIRQ);
 546
 547        if (VALID_EVTCHN(evtchn))
 548                goto out;
 549
 550        bind_pirq.pirq = pirq_from_irq(irq);
 551        /* NB. We are happy to share unless we are probing. */
 552        bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
 553                                        BIND_PIRQ__WILL_SHARE : 0;
 554        rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
 555        if (rc != 0) {
 556                if (!probing_irq(irq))
 557                        printk(KERN_INFO "Failed to obtain physical IRQ %d\n",
 558                               irq);
 559                return 0;
 560        }
 561        evtchn = bind_pirq.port;
 562
 563        pirq_query_unmask(irq);
 564
 565        evtchn_to_irq[evtchn] = irq;
 566        bind_evtchn_to_cpu(evtchn, 0);
 567        info->evtchn = evtchn;
 568
 569out:
 570        unmask_evtchn(evtchn);
 571        eoi_pirq(irq_get_irq_data(irq));
 572
 573        return 0;
 574}
 575
 576static unsigned int startup_pirq(struct irq_data *data)
 577{
 578        return __startup_pirq(data->irq);
 579}
 580
 581static void shutdown_pirq(struct irq_data *data)
 582{
 583        struct evtchn_close close;
 584        unsigned int irq = data->irq;
 585        struct irq_info *info = info_for_irq(irq);
 586        int evtchn = evtchn_from_irq(irq);
 587
 588        BUG_ON(info->type != IRQT_PIRQ);
 589
 590        if (!VALID_EVTCHN(evtchn))
 591                return;
 592
 593        mask_evtchn(evtchn);
 594
 595        close.port = evtchn;
 596        if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 597                BUG();
 598
 599        bind_evtchn_to_cpu(evtchn, 0);
 600        evtchn_to_irq[evtchn] = -1;
 601        info->evtchn = 0;
 602}
 603
 604static void enable_pirq(struct irq_data *data)
 605{
 606        startup_pirq(data);
 607}
 608
 609static void disable_pirq(struct irq_data *data)
 610{
 611        disable_dynirq(data);
 612}
 613
 614int xen_irq_from_gsi(unsigned gsi)
 615{
 616        struct irq_info *info;
 617
 618        list_for_each_entry(info, &xen_irq_list_head, list) {
 619                if (info->type != IRQT_PIRQ)
 620                        continue;
 621
 622                if (info->u.pirq.gsi == gsi)
 623                        return info->irq;
 624        }
 625
 626        return -1;
 627}
 628EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
 629
 630/*
 631 * Do not make any assumptions regarding the relationship between the
 632 * IRQ number returned here and the Xen pirq argument.
 633 *
 634 * Note: We don't assign an event channel until the irq actually started
 635 * up.  Return an existing irq if we've already got one for the gsi.
 636 *
 637 * Shareable implies level triggered, not shareable implies edge
 638 * triggered here.
 639 */
 640int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 641                             unsigned pirq, int shareable, char *name)
 642{
 643        int irq = -1;
 644        struct physdev_irq irq_op;
 645
 646        mutex_lock(&irq_mapping_update_lock);
 647
 648        irq = xen_irq_from_gsi(gsi);
 649        if (irq != -1) {
 650                printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n",
 651                       irq, gsi);
 652                goto out;
 653        }
 654
 655        irq = xen_allocate_irq_gsi(gsi);
 656        if (irq < 0)
 657                goto out;
 658
 659        irq_op.irq = irq;
 660        irq_op.vector = 0;
 661
 662        /* Only the privileged domain can do this. For non-priv, the pcifront
 663         * driver provides a PCI bus that does the call to do exactly
 664         * this in the priv domain. */
 665        if (xen_initial_domain() &&
 666            HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
 667                xen_free_irq(irq);
 668                irq = -ENOSPC;
 669                goto out;
 670        }
 671
 672        xen_irq_info_pirq_init(irq, 0, pirq, gsi, irq_op.vector, DOMID_SELF,
 673                               shareable ? PIRQ_SHAREABLE : 0);
 674
 675        pirq_query_unmask(irq);
 676        /* We try to use the handler with the appropriate semantic for the
 677         * type of interrupt: if the interrupt is an edge triggered
 678         * interrupt we use handle_edge_irq.
 679         *
 680         * On the other hand if the interrupt is level triggered we use
 681         * handle_fasteoi_irq like the native code does for this kind of
 682         * interrupts.
 683         *
 684         * Depending on the Xen version, pirq_needs_eoi might return true
 685         * not only for level triggered interrupts but for edge triggered
 686         * interrupts too. In any case Xen always honors the eoi mechanism,
 687         * not injecting any more pirqs of the same kind if the first one
 688         * hasn't received an eoi yet. Therefore using the fasteoi handler
 689         * is the right choice either way.
 690         */
 691        if (shareable)
 692                irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 693                                handle_fasteoi_irq, name);
 694        else
 695                irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 696                                handle_edge_irq, name);
 697
 698out:
 699        mutex_unlock(&irq_mapping_update_lock);
 700
 701        return irq;
 702}
 703
 704#ifdef CONFIG_PCI_MSI
 705int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
 706{
 707        int rc;
 708        struct physdev_get_free_pirq op_get_free_pirq;
 709
 710        op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
 711        rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
 712
 713        WARN_ONCE(rc == -ENOSYS,
 714                  "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
 715
 716        return rc ? -1 : op_get_free_pirq.pirq;
 717}
 718
 719int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
 720                             int pirq, int vector, const char *name,
 721                             domid_t domid)
 722{
 723        int irq, ret;
 724
 725        mutex_lock(&irq_mapping_update_lock);
 726
 727        irq = xen_allocate_irq_dynamic();
 728        if (irq < 0)
 729                goto out;
 730
 731        irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_edge_irq,
 732                        name);
 733
 734        xen_irq_info_pirq_init(irq, 0, pirq, 0, vector, domid, 0);
 735        ret = irq_set_msi_desc(irq, msidesc);
 736        if (ret < 0)
 737                goto error_irq;
 738out:
 739        mutex_unlock(&irq_mapping_update_lock);
 740        return irq;
 741error_irq:
 742        mutex_unlock(&irq_mapping_update_lock);
 743        xen_free_irq(irq);
 744        return ret;
 745}
 746#endif
 747
 748int xen_destroy_irq(int irq)
 749{
 750        struct irq_desc *desc;
 751        struct physdev_unmap_pirq unmap_irq;
 752        struct irq_info *info = info_for_irq(irq);
 753        int rc = -ENOENT;
 754
 755        mutex_lock(&irq_mapping_update_lock);
 756
 757        desc = irq_to_desc(irq);
 758        if (!desc)
 759                goto out;
 760
 761        if (xen_initial_domain()) {
 762                unmap_irq.pirq = info->u.pirq.pirq;
 763                unmap_irq.domid = info->u.pirq.domid;
 764                rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
 765                /* If another domain quits without making the pci_disable_msix
 766                 * call, the Xen hypervisor takes care of freeing the PIRQs
 767                 * (free_domain_pirqs).
 768                 */
 769                if ((rc == -ESRCH && info->u.pirq.domid != DOMID_SELF))
 770                        printk(KERN_INFO "domain %d does not have %d anymore\n",
 771                                info->u.pirq.domid, info->u.pirq.pirq);
 772                else if (rc) {
 773                        printk(KERN_WARNING "unmap irq failed %d\n", rc);
 774                        goto out;
 775                }
 776        }
 777
 778        xen_free_irq(irq);
 779
 780out:
 781        mutex_unlock(&irq_mapping_update_lock);
 782        return rc;
 783}
 784
 785int xen_irq_from_pirq(unsigned pirq)
 786{
 787        int irq;
 788
 789        struct irq_info *info;
 790
 791        mutex_lock(&irq_mapping_update_lock);
 792
 793        list_for_each_entry(info, &xen_irq_list_head, list) {
 794                if (info->type != IRQT_PIRQ)
 795                        continue;
 796                irq = info->irq;
 797                if (info->u.pirq.pirq == pirq)
 798                        goto out;
 799        }
 800        irq = -1;
 801out:
 802        mutex_unlock(&irq_mapping_update_lock);
 803
 804        return irq;
 805}
 806
 807
 808int xen_pirq_from_irq(unsigned irq)
 809{
 810        return pirq_from_irq(irq);
 811}
 812EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
 813int bind_evtchn_to_irq(unsigned int evtchn)
 814{
 815        int irq;
 816
 817        mutex_lock(&irq_mapping_update_lock);
 818
 819        irq = evtchn_to_irq[evtchn];
 820
 821        if (irq == -1) {
 822                irq = xen_allocate_irq_dynamic();
 823                if (irq == -1)
 824                        goto out;
 825
 826                irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
 827                                              handle_edge_irq, "event");
 828
 829                xen_irq_info_evtchn_init(irq, evtchn);
 830        } else {
 831                struct irq_info *info = info_for_irq(irq);
 832                WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
 833        }
 834
 835out:
 836        mutex_unlock(&irq_mapping_update_lock);
 837
 838        return irq;
 839}
 840EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
 841
 842static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 843{
 844        struct evtchn_bind_ipi bind_ipi;
 845        int evtchn, irq;
 846
 847        mutex_lock(&irq_mapping_update_lock);
 848
 849        irq = per_cpu(ipi_to_irq, cpu)[ipi];
 850
 851        if (irq == -1) {
 852                irq = xen_allocate_irq_dynamic();
 853                if (irq < 0)
 854                        goto out;
 855
 856                irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 857                                              handle_percpu_irq, "ipi");
 858
 859                bind_ipi.vcpu = cpu;
 860                if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
 861                                                &bind_ipi) != 0)
 862                        BUG();
 863                evtchn = bind_ipi.port;
 864
 865                xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
 866
 867                bind_evtchn_to_cpu(evtchn, cpu);
 868        } else {
 869                struct irq_info *info = info_for_irq(irq);
 870                WARN_ON(info == NULL || info->type != IRQT_IPI);
 871        }
 872
 873 out:
 874        mutex_unlock(&irq_mapping_update_lock);
 875        return irq;
 876}
 877
 878static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
 879                                          unsigned int remote_port)
 880{
 881        struct evtchn_bind_interdomain bind_interdomain;
 882        int err;
 883
 884        bind_interdomain.remote_dom  = remote_domain;
 885        bind_interdomain.remote_port = remote_port;
 886
 887        err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
 888                                          &bind_interdomain);
 889
 890        return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
 891}
 892
 893static int find_virq(unsigned int virq, unsigned int cpu)
 894{
 895        struct evtchn_status status;
 896        int port, rc = -ENOENT;
 897
 898        memset(&status, 0, sizeof(status));
 899        for (port = 0; port <= NR_EVENT_CHANNELS; port++) {
 900                status.dom = DOMID_SELF;
 901                status.port = port;
 902                rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status);
 903                if (rc < 0)
 904                        continue;
 905                if (status.status != EVTCHNSTAT_virq)
 906                        continue;
 907                if (status.u.virq == virq && status.vcpu == cpu) {
 908                        rc = port;
 909                        break;
 910                }
 911        }
 912        return rc;
 913}
 914
 915int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 916{
 917        struct evtchn_bind_virq bind_virq;
 918        int evtchn, irq, ret;
 919
 920        mutex_lock(&irq_mapping_update_lock);
 921
 922        irq = per_cpu(virq_to_irq, cpu)[virq];
 923
 924        if (irq == -1) {
 925                irq = xen_allocate_irq_dynamic();
 926                if (irq == -1)
 927                        goto out;
 928
 929                irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 930                                              handle_percpu_irq, "virq");
 931
 932                bind_virq.virq = virq;
 933                bind_virq.vcpu = cpu;
 934                ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
 935                                                &bind_virq);
 936                if (ret == 0)
 937                        evtchn = bind_virq.port;
 938                else {
 939                        if (ret == -EEXIST)
 940                                ret = find_virq(virq, cpu);
 941                        BUG_ON(ret < 0);
 942                        evtchn = ret;
 943                }
 944
 945                xen_irq_info_virq_init(cpu, irq, evtchn, virq);
 946
 947                bind_evtchn_to_cpu(evtchn, cpu);
 948        } else {
 949                struct irq_info *info = info_for_irq(irq);
 950                WARN_ON(info == NULL || info->type != IRQT_VIRQ);
 951        }
 952
 953out:
 954        mutex_unlock(&irq_mapping_update_lock);
 955
 956        return irq;
 957}
 958
 959static void unbind_from_irq(unsigned int irq)
 960{
 961        struct evtchn_close close;
 962        int evtchn = evtchn_from_irq(irq);
 963        struct irq_info *info = irq_get_handler_data(irq);
 964
 965        mutex_lock(&irq_mapping_update_lock);
 966
 967        if (info->refcnt > 0) {
 968                info->refcnt--;
 969                if (info->refcnt != 0)
 970                        goto done;
 971        }
 972
 973        if (VALID_EVTCHN(evtchn)) {
 974                close.port = evtchn;
 975                if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 976                        BUG();
 977
 978                switch (type_from_irq(irq)) {
 979                case IRQT_VIRQ:
 980                        per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
 981                                [virq_from_irq(irq)] = -1;
 982                        break;
 983                case IRQT_IPI:
 984                        per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn))
 985                                [ipi_from_irq(irq)] = -1;
 986                        break;
 987                default:
 988                        break;
 989                }
 990
 991                /* Closed ports are implicitly re-bound to VCPU0. */
 992                bind_evtchn_to_cpu(evtchn, 0);
 993
 994                evtchn_to_irq[evtchn] = -1;
 995        }
 996
 997        BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
 998
 999        xen_free_irq(irq);
1000
1001 done:
1002        mutex_unlock(&irq_mapping_update_lock);
1003}
1004
1005int bind_evtchn_to_irqhandler(unsigned int evtchn,
1006                              irq_handler_t handler,
1007                              unsigned long irqflags,
1008                              const char *devname, void *dev_id)
1009{
1010        int irq, retval;
1011
1012        irq = bind_evtchn_to_irq(evtchn);
1013        if (irq < 0)
1014                return irq;
1015        retval = request_irq(irq, handler, irqflags, devname, dev_id);
1016        if (retval != 0) {
1017                unbind_from_irq(irq);
1018                return retval;
1019        }
1020
1021        return irq;
1022}
1023EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
1024
1025int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
1026                                          unsigned int remote_port,
1027                                          irq_handler_t handler,
1028                                          unsigned long irqflags,
1029                                          const char *devname,
1030                                          void *dev_id)
1031{
1032        int irq, retval;
1033
1034        irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
1035        if (irq < 0)
1036                return irq;
1037
1038        retval = request_irq(irq, handler, irqflags, devname, dev_id);
1039        if (retval != 0) {
1040                unbind_from_irq(irq);
1041                return retval;
1042        }
1043
1044        return irq;
1045}
1046EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
1047
1048int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
1049                            irq_handler_t handler,
1050                            unsigned long irqflags, const char *devname, void *dev_id)
1051{
1052        int irq, retval;
1053
1054        irq = bind_virq_to_irq(virq, cpu);
1055        if (irq < 0)
1056                return irq;
1057        retval = request_irq(irq, handler, irqflags, devname, dev_id);
1058        if (retval != 0) {
1059                unbind_from_irq(irq);
1060                return retval;
1061        }
1062
1063        return irq;
1064}
1065EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
1066
1067int bind_ipi_to_irqhandler(enum ipi_vector ipi,
1068                           unsigned int cpu,
1069                           irq_handler_t handler,
1070                           unsigned long irqflags,
1071                           const char *devname,
1072                           void *dev_id)
1073{
1074        int irq, retval;
1075
1076        irq = bind_ipi_to_irq(ipi, cpu);
1077        if (irq < 0)
1078                return irq;
1079
1080        irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME | IRQF_EARLY_RESUME;
1081        retval = request_irq(irq, handler, irqflags, devname, dev_id);
1082        if (retval != 0) {
1083                unbind_from_irq(irq);
1084                return retval;
1085        }
1086
1087        return irq;
1088}
1089
1090void unbind_from_irqhandler(unsigned int irq, void *dev_id)
1091{
1092        free_irq(irq, dev_id);
1093        unbind_from_irq(irq);
1094}
1095EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
1096
1097int evtchn_make_refcounted(unsigned int evtchn)
1098{
1099        int irq = evtchn_to_irq[evtchn];
1100        struct irq_info *info;
1101
1102        if (irq == -1)
1103                return -ENOENT;
1104
1105        info = irq_get_handler_data(irq);
1106
1107        if (!info)
1108                return -ENOENT;
1109
1110        WARN_ON(info->refcnt != -1);
1111
1112        info->refcnt = 1;
1113
1114        return 0;
1115}
1116EXPORT_SYMBOL_GPL(evtchn_make_refcounted);
1117
1118int evtchn_get(unsigned int evtchn)
1119{
1120        int irq;
1121        struct irq_info *info;
1122        int err = -ENOENT;
1123
1124        if (evtchn >= NR_EVENT_CHANNELS)
1125                return -EINVAL;
1126
1127        mutex_lock(&irq_mapping_update_lock);
1128
1129        irq = evtchn_to_irq[evtchn];
1130        if (irq == -1)
1131                goto done;
1132
1133        info = irq_get_handler_data(irq);
1134
1135        if (!info)
1136                goto done;
1137
1138        err = -EINVAL;
1139        if (info->refcnt <= 0)
1140                goto done;
1141
1142        info->refcnt++;
1143        err = 0;
1144 done:
1145        mutex_unlock(&irq_mapping_update_lock);
1146
1147        return err;
1148}
1149EXPORT_SYMBOL_GPL(evtchn_get);
1150
1151void evtchn_put(unsigned int evtchn)
1152{
1153        int irq = evtchn_to_irq[evtchn];
1154        if (WARN_ON(irq == -1))
1155                return;
1156        unbind_from_irq(irq);
1157}
1158EXPORT_SYMBOL_GPL(evtchn_put);
1159
1160void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
1161{
1162        int irq = per_cpu(ipi_to_irq, cpu)[vector];
1163        BUG_ON(irq < 0);
1164        notify_remote_via_irq(irq);
1165}
1166
1167irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
1168{
1169        struct shared_info *sh = HYPERVISOR_shared_info;
1170        int cpu = smp_processor_id();
1171        unsigned long *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu);
1172        int i;
1173        unsigned long flags;
1174        static DEFINE_SPINLOCK(debug_lock);
1175        struct vcpu_info *v;
1176
1177        spin_lock_irqsave(&debug_lock, flags);
1178
1179        printk("\nvcpu %d\n  ", cpu);
1180
1181        for_each_online_cpu(i) {
1182                int pending;
1183                v = per_cpu(xen_vcpu, i);
1184                pending = (get_irq_regs() && i == cpu)
1185                        ? xen_irqs_disabled(get_irq_regs())
1186                        : v->evtchn_upcall_mask;
1187                printk("%d: masked=%d pending=%d event_sel %0*lx\n  ", i,
1188                       pending, v->evtchn_upcall_pending,
1189                       (int)(sizeof(v->evtchn_pending_sel)*2),
1190                       v->evtchn_pending_sel);
1191        }
1192        v = per_cpu(xen_vcpu, cpu);
1193
1194        printk("\npending:\n   ");
1195        for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
1196                printk("%0*lx%s", (int)sizeof(sh->evtchn_pending[0])*2,
1197                       sh->evtchn_pending[i],
1198                       i % 8 == 0 ? "\n   " : " ");
1199        printk("\nglobal mask:\n   ");
1200        for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
1201                printk("%0*lx%s",
1202                       (int)(sizeof(sh->evtchn_mask[0])*2),
1203                       sh->evtchn_mask[i],
1204                       i % 8 == 0 ? "\n   " : " ");
1205
1206        printk("\nglobally unmasked:\n   ");
1207        for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
1208                printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
1209                       sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
1210                       i % 8 == 0 ? "\n   " : " ");
1211
1212        printk("\nlocal cpu%d mask:\n   ", cpu);
1213        for (i = (NR_EVENT_CHANNELS/BITS_PER_LONG)-1; i >= 0; i--)
1214                printk("%0*lx%s", (int)(sizeof(cpu_evtchn[0])*2),
1215                       cpu_evtchn[i],
1216                       i % 8 == 0 ? "\n   " : " ");
1217
1218        printk("\nlocally unmasked:\n   ");
1219        for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) {
1220                unsigned long pending = sh->evtchn_pending[i]
1221                        & ~sh->evtchn_mask[i]
1222                        & cpu_evtchn[i];
1223                printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
1224                       pending, i % 8 == 0 ? "\n   " : " ");
1225        }
1226
1227        printk("\npending list:\n");
1228        for (i = 0; i < NR_EVENT_CHANNELS; i++) {
1229                if (sync_test_bit(i, sh->evtchn_pending)) {
1230                        int word_idx = i / BITS_PER_LONG;
1231                        printk("  %d: event %d -> irq %d%s%s%s\n",
1232                               cpu_from_evtchn(i), i,
1233                               evtchn_to_irq[i],
1234                               sync_test_bit(word_idx, &v->evtchn_pending_sel)
1235                                             ? "" : " l2-clear",
1236                               !sync_test_bit(i, sh->evtchn_mask)
1237                                             ? "" : " globally-masked",
1238                               sync_test_bit(i, cpu_evtchn)
1239                                             ? "" : " locally-masked");
1240                }
1241        }
1242
1243        spin_unlock_irqrestore(&debug_lock, flags);
1244
1245        return IRQ_HANDLED;
1246}
1247
1248static DEFINE_PER_CPU(unsigned, xed_nesting_count);
1249static DEFINE_PER_CPU(unsigned int, current_word_idx);
1250static DEFINE_PER_CPU(unsigned int, current_bit_idx);
1251
1252/*
1253 * Mask out the i least significant bits of w
1254 */
1255#define MASK_LSBS(w, i) (w & ((~0UL) << i))
1256
1257/*
1258 * Search the CPUs pending events bitmasks.  For each one found, map
1259 * the event number to an irq, and feed it into do_IRQ() for
1260 * handling.
1261 *
1262 * Xen uses a two-level bitmap to speed searching.  The first level is
1263 * a bitset of words which contain pending event bits.  The second
1264 * level is a bitset of pending events themselves.
1265 */
1266static void __xen_evtchn_do_upcall(void)
1267{
1268        int start_word_idx, start_bit_idx;
1269        int word_idx, bit_idx;
1270        int i;
1271        int cpu = get_cpu();
1272        struct shared_info *s = HYPERVISOR_shared_info;
1273        struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1274        unsigned count;
1275
1276        do {
1277                unsigned long pending_words;
1278
1279                vcpu_info->evtchn_upcall_pending = 0;
1280
1281                if (__this_cpu_inc_return(xed_nesting_count) - 1)
1282                        goto out;
1283
1284#ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
1285                /* Clear master flag /before/ clearing selector flag. */
1286                wmb();
1287#endif
1288                pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
1289
1290                start_word_idx = __this_cpu_read(current_word_idx);
1291                start_bit_idx = __this_cpu_read(current_bit_idx);
1292
1293                word_idx = start_word_idx;
1294
1295                for (i = 0; pending_words != 0; i++) {
1296                        unsigned long pending_bits;
1297                        unsigned long words;
1298
1299                        words = MASK_LSBS(pending_words, word_idx);
1300
1301                        /*
1302                         * If we masked out all events, wrap to beginning.
1303                         */
1304                        if (words == 0) {
1305                                word_idx = 0;
1306                                bit_idx = 0;
1307                                continue;
1308                        }
1309                        word_idx = __ffs(words);
1310
1311                        pending_bits = active_evtchns(cpu, s, word_idx);
1312                        bit_idx = 0; /* usually scan entire word from start */
1313                        if (word_idx == start_word_idx) {
1314                                /* We scan the starting word in two parts */
1315                                if (i == 0)
1316                                        /* 1st time: start in the middle */
1317                                        bit_idx = start_bit_idx;
1318                                else
1319                                        /* 2nd time: mask bits done already */
1320                                        bit_idx &= (1UL << start_bit_idx) - 1;
1321                        }
1322
1323                        do {
1324                                unsigned long bits;
1325                                int port, irq;
1326                                struct irq_desc *desc;
1327
1328                                bits = MASK_LSBS(pending_bits, bit_idx);
1329
1330                                /* If we masked out all events, move on. */
1331                                if (bits == 0)
1332                                        break;
1333
1334                                bit_idx = __ffs(bits);
1335
1336                                /* Process port. */
1337                                port = (word_idx * BITS_PER_LONG) + bit_idx;
1338                                irq = evtchn_to_irq[port];
1339
1340                                if (irq != -1) {
1341                                        desc = irq_to_desc(irq);
1342                                        if (desc)
1343                                                generic_handle_irq_desc(irq, desc);
1344                                }
1345
1346                                bit_idx = (bit_idx + 1) % BITS_PER_LONG;
1347
1348                                /* Next caller starts at last processed + 1 */
1349                                __this_cpu_write(current_word_idx,
1350                                                 bit_idx ? word_idx :
1351                                                 (word_idx+1) % BITS_PER_LONG);
1352                                __this_cpu_write(current_bit_idx, bit_idx);
1353                        } while (bit_idx != 0);
1354
1355                        /* Scan start_l1i twice; all others once. */
1356                        if ((word_idx != start_word_idx) || (i != 0))
1357                                pending_words &= ~(1UL << word_idx);
1358
1359                        word_idx = (word_idx + 1) % BITS_PER_LONG;
1360                }
1361
1362                BUG_ON(!irqs_disabled());
1363
1364                count = __this_cpu_read(xed_nesting_count);
1365                __this_cpu_write(xed_nesting_count, 0);
1366        } while (count != 1 || vcpu_info->evtchn_upcall_pending);
1367
1368out:
1369
1370        put_cpu();
1371}
1372
1373void xen_evtchn_do_upcall(struct pt_regs *regs)
1374{
1375        struct pt_regs *old_regs = set_irq_regs(regs);
1376
1377        irq_enter();
1378        exit_idle();
1379
1380        __xen_evtchn_do_upcall();
1381
1382        irq_exit();
1383        set_irq_regs(old_regs);
1384}
1385
1386void xen_hvm_evtchn_do_upcall(void)
1387{
1388        __xen_evtchn_do_upcall();
1389}
1390EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1391
1392/* Rebind a new event channel to an existing irq. */
1393void rebind_evtchn_irq(int evtchn, int irq)
1394{
1395        struct irq_info *info = info_for_irq(irq);
1396
1397        /* Make sure the irq is masked, since the new event channel
1398           will also be masked. */
1399        disable_irq(irq);
1400
1401        mutex_lock(&irq_mapping_update_lock);
1402
1403        /* After resume the irq<->evtchn mappings are all cleared out */
1404        BUG_ON(evtchn_to_irq[evtchn] != -1);
1405        /* Expect irq to have been bound before,
1406           so there should be a proper type */
1407        BUG_ON(info->type == IRQT_UNBOUND);
1408
1409        xen_irq_info_evtchn_init(irq, evtchn);
1410
1411        mutex_unlock(&irq_mapping_update_lock);
1412
1413        /* new event channels are always bound to cpu 0 */
1414        irq_set_affinity(irq, cpumask_of(0));
1415
1416        /* Unmask the event channel. */
1417        enable_irq(irq);
1418}
1419
1420/* Rebind an evtchn so that it gets delivered to a specific cpu */
1421static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
1422{
1423        struct evtchn_bind_vcpu bind_vcpu;
1424        int evtchn = evtchn_from_irq(irq);
1425
1426        if (!VALID_EVTCHN(evtchn))
1427                return -1;
1428
1429        /*
1430         * Events delivered via platform PCI interrupts are always
1431         * routed to vcpu 0 and hence cannot be rebound.
1432         */
1433        if (xen_hvm_domain() && !xen_have_vector_callback)
1434                return -1;
1435
1436        /* Send future instances of this interrupt to other vcpu. */
1437        bind_vcpu.port = evtchn;
1438        bind_vcpu.vcpu = tcpu;
1439
1440        /*
1441         * If this fails, it usually just indicates that we're dealing with a
1442         * virq or IPI channel, which don't actually need to be rebound. Ignore
1443         * it, but don't do the xenlinux-level rebind in that case.
1444         */
1445        if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1446                bind_evtchn_to_cpu(evtchn, tcpu);
1447
1448        return 0;
1449}
1450
1451static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1452                            bool force)
1453{
1454        unsigned tcpu = cpumask_first(dest);
1455
1456        return rebind_irq_to_cpu(data->irq, tcpu);
1457}
1458
1459int resend_irq_on_evtchn(unsigned int irq)
1460{
1461        int masked, evtchn = evtchn_from_irq(irq);
1462        struct shared_info *s = HYPERVISOR_shared_info;
1463
1464        if (!VALID_EVTCHN(evtchn))
1465                return 1;
1466
1467        masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
1468        sync_set_bit(evtchn, s->evtchn_pending);
1469        if (!masked)
1470                unmask_evtchn(evtchn);
1471
1472        return 1;
1473}
1474
1475static void enable_dynirq(struct irq_data *data)
1476{
1477        int evtchn = evtchn_from_irq(data->irq);
1478
1479        if (VALID_EVTCHN(evtchn))
1480                unmask_evtchn(evtchn);
1481}
1482
1483static void disable_dynirq(struct irq_data *data)
1484{
1485        int evtchn = evtchn_from_irq(data->irq);
1486
1487        if (VALID_EVTCHN(evtchn))
1488                mask_evtchn(evtchn);
1489}
1490
1491static void ack_dynirq(struct irq_data *data)
1492{
1493        int evtchn = evtchn_from_irq(data->irq);
1494
1495        irq_move_irq(data);
1496
1497        if (VALID_EVTCHN(evtchn))
1498                clear_evtchn(evtchn);
1499}
1500
1501static void mask_ack_dynirq(struct irq_data *data)
1502{
1503        disable_dynirq(data);
1504        ack_dynirq(data);
1505}
1506
1507static int retrigger_dynirq(struct irq_data *data)
1508{
1509        int evtchn = evtchn_from_irq(data->irq);
1510        struct shared_info *sh = HYPERVISOR_shared_info;
1511        int ret = 0;
1512
1513        if (VALID_EVTCHN(evtchn)) {
1514                int masked;
1515
1516                masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
1517                sync_set_bit(evtchn, sh->evtchn_pending);
1518                if (!masked)
1519                        unmask_evtchn(evtchn);
1520                ret = 1;
1521        }
1522
1523        return ret;
1524}
1525
1526static void restore_pirqs(void)
1527{
1528        int pirq, rc, irq, gsi;
1529        struct physdev_map_pirq map_irq;
1530        struct irq_info *info;
1531
1532        list_for_each_entry(info, &xen_irq_list_head, list) {
1533                if (info->type != IRQT_PIRQ)
1534                        continue;
1535
1536                pirq = info->u.pirq.pirq;
1537                gsi = info->u.pirq.gsi;
1538                irq = info->irq;
1539
1540                /* save/restore of PT devices doesn't work, so at this point the
1541                 * only devices present are GSI based emulated devices */
1542                if (!gsi)
1543                        continue;
1544
1545                map_irq.domid = DOMID_SELF;
1546                map_irq.type = MAP_PIRQ_TYPE_GSI;
1547                map_irq.index = gsi;
1548                map_irq.pirq = pirq;
1549
1550                rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1551                if (rc) {
1552                        printk(KERN_WARNING "xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1553                                        gsi, irq, pirq, rc);
1554                        xen_free_irq(irq);
1555                        continue;
1556                }
1557
1558                printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1559
1560                __startup_pirq(irq);
1561        }
1562}
1563
1564static void restore_cpu_virqs(unsigned int cpu)
1565{
1566        struct evtchn_bind_virq bind_virq;
1567        int virq, irq, evtchn;
1568
1569        for (virq = 0; virq < NR_VIRQS; virq++) {
1570                if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1571                        continue;
1572
1573                BUG_ON(virq_from_irq(irq) != virq);
1574
1575                /* Get a new binding from Xen. */
1576                bind_virq.virq = virq;
1577                bind_virq.vcpu = cpu;
1578                if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1579                                                &bind_virq) != 0)
1580                        BUG();
1581                evtchn = bind_virq.port;
1582
1583                /* Record the new mapping. */
1584                xen_irq_info_virq_init(cpu, irq, evtchn, virq);
1585                bind_evtchn_to_cpu(evtchn, cpu);
1586        }
1587}
1588
1589static void restore_cpu_ipis(unsigned int cpu)
1590{
1591        struct evtchn_bind_ipi bind_ipi;
1592        int ipi, irq, evtchn;
1593
1594        for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1595                if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1596                        continue;
1597
1598                BUG_ON(ipi_from_irq(irq) != ipi);
1599
1600                /* Get a new binding from Xen. */
1601                bind_ipi.vcpu = cpu;
1602                if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1603                                                &bind_ipi) != 0)
1604                        BUG();
1605                evtchn = bind_ipi.port;
1606
1607                /* Record the new mapping. */
1608                xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
1609                bind_evtchn_to_cpu(evtchn, cpu);
1610        }
1611}
1612
1613/* Clear an irq's pending state, in preparation for polling on it */
1614void xen_clear_irq_pending(int irq)
1615{
1616        int evtchn = evtchn_from_irq(irq);
1617
1618        if (VALID_EVTCHN(evtchn))
1619                clear_evtchn(evtchn);
1620}
1621EXPORT_SYMBOL(xen_clear_irq_pending);
1622void xen_set_irq_pending(int irq)
1623{
1624        int evtchn = evtchn_from_irq(irq);
1625
1626        if (VALID_EVTCHN(evtchn))
1627                set_evtchn(evtchn);
1628}
1629
1630bool xen_test_irq_pending(int irq)
1631{
1632        int evtchn = evtchn_from_irq(irq);
1633        bool ret = false;
1634
1635        if (VALID_EVTCHN(evtchn))
1636                ret = test_evtchn(evtchn);
1637
1638        return ret;
1639}
1640
1641/* Poll waiting for an irq to become pending with timeout.  In the usual case,
1642 * the irq will be disabled so it won't deliver an interrupt. */
1643void xen_poll_irq_timeout(int irq, u64 timeout)
1644{
1645        evtchn_port_t evtchn = evtchn_from_irq(irq);
1646
1647        if (VALID_EVTCHN(evtchn)) {
1648                struct sched_poll poll;
1649
1650                poll.nr_ports = 1;
1651                poll.timeout = timeout;
1652                set_xen_guest_handle(poll.ports, &evtchn);
1653
1654                if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1655                        BUG();
1656        }
1657}
1658EXPORT_SYMBOL(xen_poll_irq_timeout);
1659/* Poll waiting for an irq to become pending.  In the usual case, the
1660 * irq will be disabled so it won't deliver an interrupt. */
1661void xen_poll_irq(int irq)
1662{
1663        xen_poll_irq_timeout(irq, 0 /* no timeout */);
1664}
1665
1666/* Check whether the IRQ line is shared with other guests. */
1667int xen_test_irq_shared(int irq)
1668{
1669        struct irq_info *info = info_for_irq(irq);
1670        struct physdev_irq_status_query irq_status = { .irq = info->u.pirq.pirq };
1671
1672        if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
1673                return 0;
1674        return !(irq_status.flags & XENIRQSTAT_shared);
1675}
1676EXPORT_SYMBOL_GPL(xen_test_irq_shared);
1677
1678void xen_irq_resume(void)
1679{
1680        unsigned int cpu, evtchn;
1681        struct irq_info *info;
1682
1683        init_evtchn_cpu_bindings();
1684
1685        /* New event-channel space is not 'live' yet. */
1686        for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1687                mask_evtchn(evtchn);
1688
1689        /* No IRQ <-> event-channel mappings. */
1690        list_for_each_entry(info, &xen_irq_list_head, list)
1691                info->evtchn = 0; /* zap event-channel binding */
1692
1693        for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1694                evtchn_to_irq[evtchn] = -1;
1695
1696        for_each_possible_cpu(cpu) {
1697                restore_cpu_virqs(cpu);
1698                restore_cpu_ipis(cpu);
1699        }
1700
1701        restore_pirqs();
1702}
1703
1704static struct irq_chip xen_dynamic_chip __read_mostly = {
1705        .name                   = "xen-dyn",
1706
1707        .irq_disable            = disable_dynirq,
1708        .irq_mask               = disable_dynirq,
1709        .irq_unmask             = enable_dynirq,
1710
1711        .irq_ack                = ack_dynirq,
1712        .irq_mask_ack           = mask_ack_dynirq,
1713
1714        .irq_set_affinity       = set_affinity_irq,
1715        .irq_retrigger          = retrigger_dynirq,
1716};
1717
1718static struct irq_chip xen_pirq_chip __read_mostly = {
1719        .name                   = "xen-pirq",
1720
1721        .irq_startup            = startup_pirq,
1722        .irq_shutdown           = shutdown_pirq,
1723        .irq_enable             = enable_pirq,
1724        .irq_disable            = disable_pirq,
1725
1726        .irq_mask               = disable_dynirq,
1727        .irq_unmask             = enable_dynirq,
1728
1729        .irq_ack                = eoi_pirq,
1730        .irq_eoi                = eoi_pirq,
1731        .irq_mask_ack           = mask_ack_pirq,
1732
1733        .irq_set_affinity       = set_affinity_irq,
1734
1735        .irq_retrigger          = retrigger_dynirq,
1736};
1737
1738static struct irq_chip xen_percpu_chip __read_mostly = {
1739        .name                   = "xen-percpu",
1740
1741        .irq_disable            = disable_dynirq,
1742        .irq_mask               = disable_dynirq,
1743        .irq_unmask             = enable_dynirq,
1744
1745        .irq_ack                = ack_dynirq,
1746};
1747
1748int xen_set_callback_via(uint64_t via)
1749{
1750        struct xen_hvm_param a;
1751        a.domid = DOMID_SELF;
1752        a.index = HVM_PARAM_CALLBACK_IRQ;
1753        a.value = via;
1754        return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1755}
1756EXPORT_SYMBOL_GPL(xen_set_callback_via);
1757
1758#ifdef CONFIG_XEN_PVHVM
1759/* Vector callbacks are better than PCI interrupts to receive event
1760 * channel notifications because we can receive vector callbacks on any
1761 * vcpu and we don't need PCI support or APIC interactions. */
1762void xen_callback_vector(void)
1763{
1764        int rc;
1765        uint64_t callback_via;
1766        if (xen_have_vector_callback) {
1767                callback_via = HVM_CALLBACK_VECTOR(XEN_HVM_EVTCHN_CALLBACK);
1768                rc = xen_set_callback_via(callback_via);
1769                if (rc) {
1770                        printk(KERN_ERR "Request for Xen HVM callback vector"
1771                                        " failed.\n");
1772                        xen_have_vector_callback = 0;
1773                        return;
1774                }
1775                printk(KERN_INFO "Xen HVM callback vector for event delivery is "
1776                                "enabled\n");
1777                /* in the restore case the vector has already been allocated */
1778                if (!test_bit(XEN_HVM_EVTCHN_CALLBACK, used_vectors))
1779                        alloc_intr_gate(XEN_HVM_EVTCHN_CALLBACK, xen_hvm_callback_vector);
1780        }
1781}
1782#else
1783void xen_callback_vector(void) {}
1784#endif
1785
1786void __init xen_init_IRQ(void)
1787{
1788        int i, rc;
1789
1790        evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
1791                                    GFP_KERNEL);
1792        BUG_ON(!evtchn_to_irq);
1793        for (i = 0; i < NR_EVENT_CHANNELS; i++)
1794                evtchn_to_irq[i] = -1;
1795
1796        init_evtchn_cpu_bindings();
1797
1798        /* No event channels are 'live' right now. */
1799        for (i = 0; i < NR_EVENT_CHANNELS; i++)
1800                mask_evtchn(i);
1801
1802        pirq_needs_eoi = pirq_needs_eoi_flag;
1803
1804        if (xen_hvm_domain()) {
1805                xen_callback_vector();
1806                native_init_IRQ();
1807                /* pci_xen_hvm_init must be called after native_init_IRQ so that
1808                 * __acpi_register_gsi can point at the right function */
1809                pci_xen_hvm_init();
1810        } else {
1811                struct physdev_pirq_eoi_gmfn eoi_gmfn;
1812
1813                irq_ctx_init(smp_processor_id());
1814                if (xen_initial_domain())
1815                        pci_xen_initial_domain();
1816
1817                pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
1818                eoi_gmfn.gmfn = virt_to_mfn(pirq_eoi_map);
1819                rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn);
1820                if (rc != 0) {
1821                        free_page((unsigned long) pirq_eoi_map);
1822                        pirq_eoi_map = NULL;
1823                } else
1824                        pirq_needs_eoi = pirq_check_eoi_map;
1825        }
1826}
1827
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