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