arch/x86/xen/smp.c

   1 /*
   2  * Xen SMP support
   3  *
   4  * This file implements the Xen versions of smp_ops.  SMP under Xen is
   5  * very straightforward.  Bringing a CPU up is simply a matter of
   6  * loading its initial context and setting it running.
   7  *
   8  * IPIs are handled through the Xen event mechanism.
   9  *
  10  * Because virtual CPUs can be scheduled onto any real CPU, there's no
  11  * useful topology information for the kernel to make use of.  As a
  12  * result, all CPUs are treated as if they're single-core and
  13  * single-threaded.
  14  */
  15 #include <linux/sched.h>
  16 #include <linux/err.h>
  17 #include <linux/slab.h>
  18 #include <linux/smp.h>
  19 #include <linux/irq_work.h>
  20 #include <linux/tick.h>
  21
  22 #include <asm/paravirt.h>
  23 #include <asm/desc.h>
  24 #include <asm/pgtable.h>
  25 #include <asm/cpu.h>
  26
  27 #include <xen/interface/xen.h>
  28 #include <xen/interface/vcpu.h>
  29
  30 #include <asm/xen/interface.h>
  31 #include <asm/xen/hypercall.h>
  32
  33 #include <xen/xen.h>
  34 #include <xen/page.h>
  35 #include <xen/events.h>
  36
  37 #include <xen/hvc-console.h>
  38 #include "xen-ops.h"
  39 #include "mmu.h"
  40 #include "smp.h"
  41
  42 cpumask_var_t xen_cpu_initialized_map;
  43
  44 struct xen_common_irq {
  45         int irq;
  46         char *name;
  47 };
  48 static DEFINE_PER_CPU(struct xen_common_irq, xen_resched_irq) = { .irq = -1 };
  49 static DEFINE_PER_CPU(struct xen_common_irq, xen_callfunc_irq) = { .irq = -1 };
  50 static DEFINE_PER_CPU(struct xen_common_irq, xen_callfuncsingle_irq) = { .irq = -1 };
  51 static DEFINE_PER_CPU(struct xen_common_irq, xen_irq_work) = { .irq = -1 };
  52 static DEFINE_PER_CPU(struct xen_common_irq, xen_debug_irq) = { .irq = -1 };
  53
  54 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
  55 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
  56 static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id);
  57
  58 /*
  59  * Reschedule call back.
  60  */
  61 static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
  62 {
  63         inc_irq_stat(irq_resched_count);
  64         scheduler_ipi();
  65
  66         return IRQ_HANDLED;
  67 }
  68
  69 static void cpu_bringup(void)
  70 {
  71         int cpu;
  72
  73         cpu_init();
  74         touch_softlockup_watchdog();
  75         preempt_disable();
  76
  77         /* PVH runs in ring 0 and allows us to do native syscalls. Yay! */
  78         if (!xen_feature(XENFEAT_supervisor_mode_kernel)) {
  79                 xen_enable_sysenter();
  80                 xen_enable_syscall();
  81         }
  82         cpu = smp_processor_id();
  83         smp_store_cpu_info(cpu);
  84         cpu_data(cpu).x86_max_cores = 1;
  85         set_cpu_sibling_map(cpu);
  86
  87         xen_setup_cpu_clockevents();
  88
  89         notify_cpu_starting(cpu);
  90
  91         set_cpu_online(cpu, true);
  92
  93         this_cpu_write(cpu_state, CPU_ONLINE);
  94
  95         wmb();
  96
  97         /* We can take interrupts now: we're officially "up". */
  98         local_irq_enable();
  99
 100         wmb();                  /* make sure everything is out */
 101 }
 102
 103 /*
 104  * Note: cpu parameter is only relevant for PVH. The reason for passing it
 105  * is we can't do smp_processor_id until the percpu segments are loaded, for
 106  * which we need the cpu number! So we pass it in rdi as first parameter.
 107  */
 108 asmlinkage __visible void cpu_bringup_and_idle(int cpu)
 109 {
 110 #ifdef CONFIG_XEN_PVH
 111         if (xen_feature(XENFEAT_auto_translated_physmap) &&
 112             xen_feature(XENFEAT_supervisor_mode_kernel))
 113                 xen_pvh_secondary_vcpu_init(cpu);
 114 #endif
 115         cpu_bringup();
 116         cpu_startup_entry(CPUHP_ONLINE);
 117 }
 118
 119 static void xen_smp_intr_free(unsigned int cpu)
 120 {
 121         if (per_cpu(xen_resched_irq, cpu).irq >= 0) {
 122                 unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu).irq, NULL);
 123                 per_cpu(xen_resched_irq, cpu).irq = -1;
 124                 kfree(per_cpu(xen_resched_irq, cpu).name);
 125                 per_cpu(xen_resched_irq, cpu).name = NULL;
 126         }
 127         if (per_cpu(xen_callfunc_irq, cpu).irq >= 0) {
 128                 unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu).irq, NULL);
 129                 per_cpu(xen_callfunc_irq, cpu).irq = -1;
 130                 kfree(per_cpu(xen_callfunc_irq, cpu).name);
 131                 per_cpu(xen_callfunc_irq, cpu).name = NULL;
 132         }
 133         if (per_cpu(xen_debug_irq, cpu).irq >= 0) {
 134                 unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu).irq, NULL);
 135                 per_cpu(xen_debug_irq, cpu).irq = -1;
 136                 kfree(per_cpu(xen_debug_irq, cpu).name);
 137                 per_cpu(xen_debug_irq, cpu).name = NULL;
 138         }
 139         if (per_cpu(xen_callfuncsingle_irq, cpu).irq >= 0) {
 140                 unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu).irq,
 141                                        NULL);
 142                 per_cpu(xen_callfuncsingle_irq, cpu).irq = -1;
 143                 kfree(per_cpu(xen_callfuncsingle_irq, cpu).name);
 144                 per_cpu(xen_callfuncsingle_irq, cpu).name = NULL;
 145         }
 146         if (xen_hvm_domain())
 147                 return;
 148
 149         if (per_cpu(xen_irq_work, cpu).irq >= 0) {
 150                 unbind_from_irqhandler(per_cpu(xen_irq_work, cpu).irq, NULL);
 151                 per_cpu(xen_irq_work, cpu).irq = -1;
 152                 kfree(per_cpu(xen_irq_work, cpu).name);
 153                 per_cpu(xen_irq_work, cpu).name = NULL;
 154         }
 155 };
 156 static int xen_smp_intr_init(unsigned int cpu)
 157 {
 158         int rc;
 159         char *resched_name, *callfunc_name, *debug_name;
 160
 161         resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
 162         rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
 163                                     cpu,
 164                                     xen_reschedule_interrupt,
 165                                     IRQF_PERCPU|IRQF_NOBALANCING,
 166                                     resched_name,
 167                                     NULL);
 168         if (rc < 0)
 169                 goto fail;
 170         per_cpu(xen_resched_irq, cpu).irq = rc;
 171         per_cpu(xen_resched_irq, cpu).name = resched_name;
 172
 173         callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
 174         rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
 175                                     cpu,
 176                                     xen_call_function_interrupt,
 177                                     IRQF_PERCPU|IRQF_NOBALANCING,
 178                                     callfunc_name,
 179                                     NULL);
 180         if (rc < 0)
 181                 goto fail;
 182         per_cpu(xen_callfunc_irq, cpu).irq = rc;
 183         per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
 184
 185         debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
 186         rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt,
 187                                      IRQF_PERCPU | IRQF_NOBALANCING,
 188                                      debug_name, NULL);
 189         if (rc < 0)
 190                 goto fail;
 191         per_cpu(xen_debug_irq, cpu).irq = rc;
 192         per_cpu(xen_debug_irq, cpu).name = debug_name;
 193
 194         callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
 195         rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
 196                                     cpu,
 197                                     xen_call_function_single_interrupt,
 198                                     IRQF_PERCPU|IRQF_NOBALANCING,
 199                                     callfunc_name,
 200                                     NULL);
 201         if (rc < 0)
 202                 goto fail;
 203         per_cpu(xen_callfuncsingle_irq, cpu).irq = rc;
 204         per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
 205
 206         /*
 207          * The IRQ worker on PVHVM goes through the native path and uses the
 208          * IPI mechanism.
 209          */
 210         if (xen_hvm_domain())
 211                 return 0;
 212
 213         callfunc_name = kasprintf(GFP_KERNEL, "irqwork%d", cpu);
 214         rc = bind_ipi_to_irqhandler(XEN_IRQ_WORK_VECTOR,
 215                                     cpu,
 216                                     xen_irq_work_interrupt,
 217                                     IRQF_PERCPU|IRQF_NOBALANCING,
 218                                     callfunc_name,
 219                                     NULL);
 220         if (rc < 0)
 221                 goto fail;
 222         per_cpu(xen_irq_work, cpu).irq = rc;
 223         per_cpu(xen_irq_work, cpu).name = callfunc_name;
 224
 225         return 0;
 226
 227  fail:
 228         xen_smp_intr_free(cpu);
 229         return rc;
 230 }
 231
 232 static void __init xen_fill_possible_map(void)
 233 {
 234         int i, rc;
 235
 236         if (xen_initial_domain())
 237                 return;
 238
 239         for (i = 0; i < nr_cpu_ids; i++) {
 240                 rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
 241                 if (rc >= 0) {
 242                         num_processors++;
 243                         set_cpu_possible(i, true);
 244                 }
 245         }
 246 }
 247
 248 static void __init xen_filter_cpu_maps(void)
 249 {
 250         int i, rc;
 251         unsigned int subtract = 0;
 252
 253         if (!xen_initial_domain())
 254                 return;
 255
 256         num_processors = 0;
 257         disabled_cpus = 0;
 258         for (i = 0; i < nr_cpu_ids; i++) {
 259                 rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
 260                 if (rc >= 0) {
 261                         num_processors++;
 262                         set_cpu_possible(i, true);
 263                 } else {
 264                         set_cpu_possible(i, false);
 265                         set_cpu_present(i, false);
 266                         subtract++;
 267                 }
 268         }
 269 #ifdef CONFIG_HOTPLUG_CPU
 270         /* This is akin to using 'nr_cpus' on the Linux command line.
 271          * Which is OK as when we use 'dom0_max_vcpus=X' we can only
 272          * have up to X, while nr_cpu_ids is greater than X. This
 273          * normally is not a problem, except when CPU hotplugging
 274          * is involved and then there might be more than X CPUs
 275          * in the guest - which will not work as there is no
 276          * hypercall to expand the max number of VCPUs an already
 277          * running guest has. So cap it up to X. */
 278         if (subtract)
 279                 nr_cpu_ids = nr_cpu_ids - subtract;
 280 #endif
 281
 282 }
 283
 284 static void __init xen_smp_prepare_boot_cpu(void)
 285 {
 286         BUG_ON(smp_processor_id() != 0);
 287         native_smp_prepare_boot_cpu();
 288
 289         if (xen_pv_domain()) {
 290                 if (!xen_feature(XENFEAT_writable_page_tables))
 291                         /* We've switched to the "real" per-cpu gdt, so make
 292                          * sure the old memory can be recycled. */
 293                         make_lowmem_page_readwrite(xen_initial_gdt);
 294
 295 #ifdef CONFIG_X86_32
 296                 /*
 297                  * Xen starts us with XEN_FLAT_RING1_DS, but linux code
 298                  * expects __USER_DS
 299                  */
 300                 loadsegment(ds, __USER_DS);
 301                 loadsegment(es, __USER_DS);
 302 #endif
 303
 304                 xen_filter_cpu_maps();
 305                 xen_setup_vcpu_info_placement();
 306         }
 307         /*
 308          * The alternative logic (which patches the unlock/lock) runs before
 309          * the smp bootup up code is activated. Hence we need to set this up
 310          * the core kernel is being patched. Otherwise we will have only
 311          * modules patched but not core code.
 312          */
 313         xen_init_spinlocks();
 314 }
 315
 316 static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
 317 {
 318         unsigned cpu;
 319         unsigned int i;
 320
 321         if (skip_ioapic_setup) {
 322                 char *m = (max_cpus == 0) ?
 323                         "The nosmp parameter is incompatible with Xen; " \
 324                         "use Xen dom0_max_vcpus=1 parameter" :
 325                         "The noapic parameter is incompatible with Xen";
 326
 327                 xen_raw_printk(m);
 328                 panic(m);
 329         }
 330         xen_init_lock_cpu(0);
 331
 332         smp_store_boot_cpu_info();
 333         cpu_data(0).x86_max_cores = 1;
 334
 335         for_each_possible_cpu(i) {
 336                 zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
 337                 zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
 338                 zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL);
 339         }
 340         set_cpu_sibling_map(0);
 341
 342         if (xen_smp_intr_init(0))
 343                 BUG();
 344
 345         if (!alloc_cpumask_var(&xen_cpu_initialized_map, GFP_KERNEL))
 346                 panic("could not allocate xen_cpu_initialized_map\n");
 347
 348         cpumask_copy(xen_cpu_initialized_map, cpumask_of(0));
 349
 350         /* Restrict the possible_map according to max_cpus. */
 351         while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) {
 352                 for (cpu = nr_cpu_ids - 1; !cpu_possible(cpu); cpu--)
 353                         continue;
 354                 set_cpu_possible(cpu, false);
 355         }
 356
 357         for_each_possible_cpu(cpu)
 358                 set_cpu_present(cpu, true);
 359 }
 360
 361 static int
 362 cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 363 {
 364         struct vcpu_guest_context *ctxt;
 365         struct desc_struct *gdt;
 366         unsigned long gdt_mfn;
 367
 368         /* used to tell cpu_init() that it can proceed with initialization */
 369         cpumask_set_cpu(cpu, cpu_callout_mask);
 370         if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
 371                 return 0;
 372
 373         ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
 374         if (ctxt == NULL)
 375                 return -ENOMEM;
 376
 377         gdt = get_cpu_gdt_table(cpu);
 378
 379 #ifdef CONFIG_X86_32
 380         /* Note: PVH is not yet supported on x86_32. */
 381         ctxt->user_regs.fs = __KERNEL_PERCPU;
 382         ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
 383 #endif
 384         memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));
 385
 386         if (!xen_feature(XENFEAT_auto_translated_physmap)) {
 387                 ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
 388                 ctxt->flags = VGCF_IN_KERNEL;
 389                 ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
 390                 ctxt->user_regs.ds = __USER_DS;
 391                 ctxt->user_regs.es = __USER_DS;
 392                 ctxt->user_regs.ss = __KERNEL_DS;
 393
 394                 xen_copy_trap_info(ctxt->trap_ctxt);
 395
 396                 ctxt->ldt_ents = 0;
 397
 398                 BUG_ON((unsigned long)gdt & ~PAGE_MASK);
 399
 400                 gdt_mfn = arbitrary_virt_to_mfn(gdt);
 401                 make_lowmem_page_readonly(gdt);
 402                 make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));
 403
 404                 ctxt->gdt_frames[0] = gdt_mfn;
 405                 ctxt->gdt_ents      = GDT_ENTRIES;
 406
 407                 ctxt->kernel_ss = __KERNEL_DS;
 408                 ctxt->kernel_sp = idle->thread.sp0;
 409
 410 #ifdef CONFIG_X86_32
 411                 ctxt->event_callback_cs     = __KERNEL_CS;
 412                 ctxt->failsafe_callback_cs  = __KERNEL_CS;
 413 #else
 414                 ctxt->gs_base_kernel = per_cpu_offset(cpu);
 415 #endif
 416                 ctxt->event_callback_eip    =
 417                                         (unsigned long)xen_hypervisor_callback;
 418                 ctxt->failsafe_callback_eip =
 419                                         (unsigned long)xen_failsafe_callback;
 420                 ctxt->user_regs.cs = __KERNEL_CS;
 421                 per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
 422         }
 423 #ifdef CONFIG_XEN_PVH
 424         else {
 425                 /*
 426                  * The vcpu comes on kernel page tables which have the NX pte
 427                  * bit set. This means before DS/SS is touched, NX in
 428                  * EFER must be set. Hence the following assembly glue code.
 429                  */
 430                 ctxt->user_regs.eip = (unsigned long)xen_pvh_early_cpu_init;
 431                 ctxt->user_regs.rdi = cpu;
 432                 ctxt->user_regs.rsi = true;  /* entry == true */
 433         }
 434 #endif
 435         ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
 436         ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));
 437         if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
 438                 BUG();
 439
 440         kfree(ctxt);
 441         return 0;
 442 }
 443
 444 static int xen_cpu_up(unsigned int cpu, struct task_struct *idle)
 445 {
 446         int rc;
 447
 448         per_cpu(current_task, cpu) = idle;
 449 #ifdef CONFIG_X86_32
 450         irq_ctx_init(cpu);
 451 #else
 452         clear_tsk_thread_flag(idle, TIF_FORK);
 453 #endif
 454         per_cpu(kernel_stack, cpu) =
 455                 (unsigned long)task_stack_page(idle) -
 456                 KERNEL_STACK_OFFSET + THREAD_SIZE;
 457
 458         xen_setup_runstate_info(cpu);
 459         xen_setup_timer(cpu);
 460         xen_init_lock_cpu(cpu);
 461
 462         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 463
 464         /* make sure interrupts start blocked */
 465         per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;
 466
 467         rc = cpu_initialize_context(cpu, idle);
 468         if (rc)
 469                 return rc;
 470
 471         if (num_online_cpus() == 1)
 472                 /* Just in case we booted with a single CPU. */
 473                 alternatives_enable_smp();
 474
 475         rc = xen_smp_intr_init(cpu);
 476         if (rc)
 477                 return rc;
 478
 479         rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
 480         BUG_ON(rc);
 481
 482         while(per_cpu(cpu_state, cpu) != CPU_ONLINE) {
 483                 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
 484                 barrier();
 485         }
 486
 487         return 0;
 488 }
 489
 490 static void xen_smp_cpus_done(unsigned int max_cpus)
 491 {
 492 }
 493
 494 #ifdef CONFIG_HOTPLUG_CPU
 495 static int xen_cpu_disable(void)
 496 {
 497         unsigned int cpu = smp_processor_id();
 498         if (cpu == 0)
 499                 return -EBUSY;
 500
 501         cpu_disable_common();
 502
 503         load_cr3(swapper_pg_dir);
 504         return 0;
 505 }
 506
 507 static void xen_cpu_die(unsigned int cpu)
 508 {
 509         while (xen_pv_domain() && HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) {
 510                 __set_current_state(TASK_UNINTERRUPTIBLE);
 511                 schedule_timeout(HZ/10);
 512         }
 513
 514         cpu_die_common(cpu);
 515
 516         xen_smp_intr_free(cpu);
 517         xen_uninit_lock_cpu(cpu);
 518         xen_teardown_timer(cpu);
 519 }
 520
 521 static void xen_play_dead(void) /* used only with HOTPLUG_CPU */
 522 {
 523         play_dead_common();
 524         HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
 525         cpu_bringup();
 526         /*
 527          * commit 4b0c0f294 (tick: Cleanup NOHZ per cpu data on cpu down)
 528          * clears certain data that the cpu_idle loop (which called us
 529          * and that we return from) expects. The only way to get that
 530          * data back is to call:
 531          */
 532         tick_nohz_idle_enter();
 533 }
 534
 535 #else /* !CONFIG_HOTPLUG_CPU */
 536 static int xen_cpu_disable(void)
 537 {
 538         return -ENOSYS;
 539 }
 540
 541 static void xen_cpu_die(unsigned int cpu)
 542 {
 543         BUG();
 544 }
 545
 546 static void xen_play_dead(void)
 547 {
 548         BUG();
 549 }
 550
 551 #endif
 552 static void stop_self(void *v)
 553 {
 554         int cpu = smp_processor_id();
 555
 556         /* make sure we're not pinning something down */
 557         load_cr3(swapper_pg_dir);
 558         /* should set up a minimal gdt */
 559
 560         set_cpu_online(cpu, false);
 561
 562         HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL);
 563         BUG();
 564 }
 565
 566 static void xen_stop_other_cpus(int wait)
 567 {
 568         smp_call_function(stop_self, NULL, wait);
 569 }
 570
 571 static void xen_smp_send_reschedule(int cpu)
 572 {
 573         xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
 574 }
 575
 576 static void __xen_send_IPI_mask(const struct cpumask *mask,
 577                               int vector)
 578 {
 579         unsigned cpu;
 580
 581         for_each_cpu_and(cpu, mask, cpu_online_mask)
 582                 xen_send_IPI_one(cpu, vector);
 583 }
 584
 585 static void xen_smp_send_call_function_ipi(const struct cpumask *mask)
 586 {
 587         int cpu;
 588
 589         __xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
 590
 591         /* Make sure other vcpus get a chance to run if they need to. */
 592         for_each_cpu(cpu, mask) {
 593                 if (xen_vcpu_stolen(cpu)) {
 594                         HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
 595                         break;
 596                 }
 597         }
 598 }
 599
 600 static void xen_smp_send_call_function_single_ipi(int cpu)
 601 {
 602         __xen_send_IPI_mask(cpumask_of(cpu),
 603                           XEN_CALL_FUNCTION_SINGLE_VECTOR);
 604 }
 605
 606 static inline int xen_map_vector(int vector)
 607 {
 608         int xen_vector;
 609
 610         switch (vector) {
 611         case RESCHEDULE_VECTOR:
 612                 xen_vector = XEN_RESCHEDULE_VECTOR;
 613                 break;
 614         case CALL_FUNCTION_VECTOR:
 615                 xen_vector = XEN_CALL_FUNCTION_VECTOR;
 616                 break;
 617         case CALL_FUNCTION_SINGLE_VECTOR:
 618                 xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
 619                 break;
 620         case IRQ_WORK_VECTOR:
 621                 xen_vector = XEN_IRQ_WORK_VECTOR;
 622                 break;
 623 #ifdef CONFIG_X86_64
 624         case NMI_VECTOR:
 625         case APIC_DM_NMI: /* Some use that instead of NMI_VECTOR */
 626                 xen_vector = XEN_NMI_VECTOR;
 627                 break;
 628 #endif
 629         default:
 630                 xen_vector = -1;
 631                 printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
 632                         vector);
 633         }
 634
 635         return xen_vector;
 636 }
 637
 638 void xen_send_IPI_mask(const struct cpumask *mask,
 639                               int vector)
 640 {
 641         int xen_vector = xen_map_vector(vector);
 642
 643         if (xen_vector >= 0)
 644                 __xen_send_IPI_mask(mask, xen_vector);
 645 }
 646
 647 void xen_send_IPI_all(int vector)
 648 {
 649         int xen_vector = xen_map_vector(vector);
 650
 651         if (xen_vector >= 0)
 652                 __xen_send_IPI_mask(cpu_online_mask, xen_vector);
 653 }
 654
 655 void xen_send_IPI_self(int vector)
 656 {
 657         int xen_vector = xen_map_vector(vector);
 658
 659         if (xen_vector >= 0)
 660                 xen_send_IPI_one(smp_processor_id(), xen_vector);
 661 }
 662
 663 void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
 664                                 int vector)
 665 {
 666         unsigned cpu;
 667         unsigned int this_cpu = smp_processor_id();
 668         int xen_vector = xen_map_vector(vector);
 669
 670         if (!(num_online_cpus() > 1) || (xen_vector < 0))
 671                 return;
 672
 673         for_each_cpu_and(cpu, mask, cpu_online_mask) {
 674                 if (this_cpu == cpu)
 675                         continue;
 676
 677                 xen_send_IPI_one(cpu, xen_vector);
 678         }
 679 }
 680
 681 void xen_send_IPI_allbutself(int vector)
 682 {
 683         xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
 684 }
 685
 686 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
 687 {
 688         irq_enter();
 689         generic_smp_call_function_interrupt();
 690         inc_irq_stat(irq_call_count);
 691         irq_exit();
 692
 693         return IRQ_HANDLED;
 694 }
 695
 696 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
 697 {
 698         irq_enter();
 699         generic_smp_call_function_single_interrupt();
 700         inc_irq_stat(irq_call_count);
 701         irq_exit();
 702
 703         return IRQ_HANDLED;
 704 }
 705
 706 static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id)
 707 {
 708         irq_enter();
 709         irq_work_run();
 710         inc_irq_stat(apic_irq_work_irqs);
 711         irq_exit();
 712
 713         return IRQ_HANDLED;
 714 }
 715
 716 static const struct smp_ops xen_smp_ops __initconst = {
 717         .smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
 718         .smp_prepare_cpus = xen_smp_prepare_cpus,
 719         .smp_cpus_done = xen_smp_cpus_done,
 720
 721         .cpu_up = xen_cpu_up,
 722         .cpu_die = xen_cpu_die,
 723         .cpu_disable = xen_cpu_disable,
 724         .play_dead = xen_play_dead,
 725
 726         .stop_other_cpus = xen_stop_other_cpus,
 727         .smp_send_reschedule = xen_smp_send_reschedule,
 728
 729         .send_call_func_ipi = xen_smp_send_call_function_ipi,
 730         .send_call_func_single_ipi = xen_smp_send_call_function_single_ipi,
 731 };
 732
 733 void __init xen_smp_init(void)
 734 {
 735         smp_ops = xen_smp_ops;
 736         xen_fill_possible_map();
 737 }
 738
 739 static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
 740 {
 741         native_smp_prepare_cpus(max_cpus);
 742         WARN_ON(xen_smp_intr_init(0));
 743
 744         xen_init_lock_cpu(0);
 745 }
 746
 747 static int xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle)
 748 {
 749         int rc;
 750         /*
 751          * xen_smp_intr_init() needs to run before native_cpu_up()
 752          * so that IPI vectors are set up on the booting CPU before
 753          * it is marked online in native_cpu_up().
 754         */
 755         rc = xen_smp_intr_init(cpu);
 756         WARN_ON(rc);
 757         if (!rc)
 758                 rc =  native_cpu_up(cpu, tidle);
 759
 760         /*
 761          * We must initialize the slowpath CPU kicker _after_ the native
 762          * path has executed. If we initialized it before none of the
 763          * unlocker IPI kicks would reach the booting CPU as the booting
 764          * CPU had not set itself 'online' in cpu_online_mask. That mask
 765          * is checked when IPIs are sent (on HVM at least).
 766          */
 767         xen_init_lock_cpu(cpu);
 768         return rc;
 769 }
 770
 771 static void xen_hvm_cpu_die(unsigned int cpu)
 772 {
 773         xen_cpu_die(cpu);
 774         native_cpu_die(cpu);
 775 }
 776
 777 void __init xen_hvm_smp_init(void)
 778 {
 779         if (!xen_have_vector_callback)
 780                 return;
 781         smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
 782         smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
 783         smp_ops.cpu_up = xen_hvm_cpu_up;
 784         smp_ops.cpu_die = xen_hvm_cpu_die;
 785         smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
 786         smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;
 787         smp_ops.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu;
 788 }