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         if (xen_pv_domain()) {
 277                 /* We've switched to the "real" per-cpu gdt, so make sure the
 278                    old memory can be recycled */
 279                 make_lowmem_page_readwrite(xen_initial_gdt);
 280
 281                 xen_filter_cpu_maps();
 282                 xen_setup_vcpu_info_placement();
 283         }
 284         /*
 285          * The alternative logic (which patches the unlock/lock) runs before
 286          * the smp bootup up code is activated. Hence we need to set this up
 287          * the core kernel is being patched. Otherwise we will have only
 288          * modules patched but not core code.
 289          */
 290         xen_init_spinlocks();
 291 }
 292
 293 static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
 294 {
 295         unsigned cpu;
 296         unsigned int i;
 297
 298         if (skip_ioapic_setup) {
 299                 char *m = (max_cpus == 0) ?
 300                         "The nosmp parameter is incompatible with Xen; " \
 301                         "use Xen dom0_max_vcpus=1 parameter" :
 302                         "The noapic parameter is incompatible with Xen";
 303
 304                 xen_raw_printk(m);
 305                 panic(m);
 306         }
 307         xen_init_lock_cpu(0);
 308
 309         smp_store_boot_cpu_info();
 310         cpu_data(0).x86_max_cores = 1;
 311
 312         for_each_possible_cpu(i) {
 313                 zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
 314                 zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
 315                 zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL);
 316         }
 317         set_cpu_sibling_map(0);
 318
 319         if (xen_smp_intr_init(0))
 320                 BUG();
 321
 322         if (!alloc_cpumask_var(&xen_cpu_initialized_map, GFP_KERNEL))
 323                 panic("could not allocate xen_cpu_initialized_map\n");
 324
 325         cpumask_copy(xen_cpu_initialized_map, cpumask_of(0));
 326
 327         /* Restrict the possible_map according to max_cpus. */
 328         while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) {
 329                 for (cpu = nr_cpu_ids - 1; !cpu_possible(cpu); cpu--)
 330                         continue;
 331                 set_cpu_possible(cpu, false);
 332         }
 333
 334         for_each_possible_cpu(cpu)
 335                 set_cpu_present(cpu, true);
 336 }
 337
 338 static int
 339 cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 340 {
 341         struct vcpu_guest_context *ctxt;
 342         struct desc_struct *gdt;
 343         unsigned long gdt_mfn;
 344
 345         if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
 346                 return 0;
 347
 348         ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
 349         if (ctxt == NULL)
 350                 return -ENOMEM;
 351
 352         gdt = get_cpu_gdt_table(cpu);
 353
 354         ctxt->flags = VGCF_IN_KERNEL;
 355         ctxt->user_regs.ss = __KERNEL_DS;
 356 #ifdef CONFIG_X86_32
 357         ctxt->user_regs.fs = __KERNEL_PERCPU;
 358         ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
 359 #else
 360         ctxt->gs_base_kernel = per_cpu_offset(cpu);
 361 #endif
 362         ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
 363
 364         memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));
 365
 366         {
 367                 ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
 368                 ctxt->user_regs.ds = __USER_DS;
 369                 ctxt->user_regs.es = __USER_DS;
 370
 371                 xen_copy_trap_info(ctxt->trap_ctxt);
 372
 373                 ctxt->ldt_ents = 0;
 374
 375                 BUG_ON((unsigned long)gdt & ~PAGE_MASK);
 376
 377                 gdt_mfn = arbitrary_virt_to_mfn(gdt);
 378                 make_lowmem_page_readonly(gdt);
 379                 make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));
 380
 381                 ctxt->gdt_frames[0] = gdt_mfn;
 382                 ctxt->gdt_ents      = GDT_ENTRIES;
 383
 384                 ctxt->kernel_ss = __KERNEL_DS;
 385                 ctxt->kernel_sp = idle->thread.sp0;
 386
 387 #ifdef CONFIG_X86_32
 388                 ctxt->event_callback_cs     = __KERNEL_CS;
 389                 ctxt->failsafe_callback_cs  = __KERNEL_CS;
 390 #endif
 391                 ctxt->event_callback_eip    =
 392                                         (unsigned long)xen_hypervisor_callback;
 393                 ctxt->failsafe_callback_eip =
 394                                         (unsigned long)xen_failsafe_callback;
 395         }
 396         ctxt->user_regs.cs = __KERNEL_CS;
 397         ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
 398
 399         per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
 400         ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));
 401
 402         if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
 403                 BUG();
 404
 405         kfree(ctxt);
 406         return 0;
 407 }
 408
 409 static int xen_cpu_up(unsigned int cpu, struct task_struct *idle)
 410 {
 411         int rc;
 412
 413         per_cpu(current_task, cpu) = idle;
 414 #ifdef CONFIG_X86_32
 415         irq_ctx_init(cpu);
 416 #else
 417         clear_tsk_thread_flag(idle, TIF_FORK);
 418         per_cpu(kernel_stack, cpu) =
 419                 (unsigned long)task_stack_page(idle) -
 420                 KERNEL_STACK_OFFSET + THREAD_SIZE;
 421 #endif
 422         xen_setup_runstate_info(cpu);
 423         xen_setup_timer(cpu);
 424         xen_init_lock_cpu(cpu);
 425
 426         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 427
 428         /* make sure interrupts start blocked */
 429         per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;
 430
 431         rc = cpu_initialize_context(cpu, idle);
 432         if (rc)
 433                 return rc;
 434
 435         if (num_online_cpus() == 1)
 436                 /* Just in case we booted with a single CPU. */
 437                 alternatives_enable_smp();
 438
 439         rc = xen_smp_intr_init(cpu);
 440         if (rc)
 441                 return rc;
 442
 443         rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
 444         BUG_ON(rc);
 445
 446         while(per_cpu(cpu_state, cpu) != CPU_ONLINE) {
 447                 HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
 448                 barrier();
 449         }
 450
 451         return 0;
 452 }
 453
 454 static void xen_smp_cpus_done(unsigned int max_cpus)
 455 {
 456 }
 457
 458 #ifdef CONFIG_HOTPLUG_CPU
 459 static int xen_cpu_disable(void)
 460 {
 461         unsigned int cpu = smp_processor_id();
 462         if (cpu == 0)
 463                 return -EBUSY;
 464
 465         cpu_disable_common();
 466
 467         load_cr3(swapper_pg_dir);
 468         return 0;
 469 }
 470
 471 static void xen_cpu_die(unsigned int cpu)
 472 {
 473         while (xen_pv_domain() && HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) {
 474                 current->state = TASK_UNINTERRUPTIBLE;
 475                 schedule_timeout(HZ/10);
 476         }
 477         xen_smp_intr_free(cpu);
 478         xen_uninit_lock_cpu(cpu);
 479         xen_teardown_timer(cpu);
 480 }
 481
 482 static void xen_play_dead(void) /* used only with HOTPLUG_CPU */
 483 {
 484         play_dead_common();
 485         HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
 486         cpu_bringup();
 487         /*
 488          * commit 4b0c0f294 (tick: Cleanup NOHZ per cpu data on cpu down)
 489          * clears certain data that the cpu_idle loop (which called us
 490          * and that we return from) expects. The only way to get that
 491          * data back is to call:
 492          */
 493         tick_nohz_idle_enter();
 494 }
 495
 496 #else /* !CONFIG_HOTPLUG_CPU */
 497 static int xen_cpu_disable(void)
 498 {
 499         return -ENOSYS;
 500 }
 501
 502 static void xen_cpu_die(unsigned int cpu)
 503 {
 504         BUG();
 505 }
 506
 507 static void xen_play_dead(void)
 508 {
 509         BUG();
 510 }
 511
 512 #endif
 513 static void stop_self(void *v)
 514 {
 515         int cpu = smp_processor_id();
 516
 517         /* make sure we're not pinning something down */
 518         load_cr3(swapper_pg_dir);
 519         /* should set up a minimal gdt */
 520
 521         set_cpu_online(cpu, false);
 522
 523         HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL);
 524         BUG();
 525 }
 526
 527 static void xen_stop_other_cpus(int wait)
 528 {
 529         smp_call_function(stop_self, NULL, wait);
 530 }
 531
 532 static void xen_smp_send_reschedule(int cpu)
 533 {
 534         xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
 535 }
 536
 537 static void __xen_send_IPI_mask(const struct cpumask *mask,
 538                               int vector)
 539 {
 540         unsigned cpu;
 541
 542         for_each_cpu_and(cpu, mask, cpu_online_mask)
 543                 xen_send_IPI_one(cpu, vector);
 544 }
 545
 546 static void xen_smp_send_call_function_ipi(const struct cpumask *mask)
 547 {
 548         int cpu;
 549
 550         __xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
 551
 552         /* Make sure other vcpus get a chance to run if they need to. */
 553         for_each_cpu(cpu, mask) {
 554                 if (xen_vcpu_stolen(cpu)) {
 555                         HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
 556                         break;
 557                 }
 558         }
 559 }
 560
 561 static void xen_smp_send_call_function_single_ipi(int cpu)
 562 {
 563         __xen_send_IPI_mask(cpumask_of(cpu),
 564                           XEN_CALL_FUNCTION_SINGLE_VECTOR);
 565 }
 566
 567 static inline int xen_map_vector(int vector)
 568 {
 569         int xen_vector;
 570
 571         switch (vector) {
 572         case RESCHEDULE_VECTOR:
 573                 xen_vector = XEN_RESCHEDULE_VECTOR;
 574                 break;
 575         case CALL_FUNCTION_VECTOR:
 576                 xen_vector = XEN_CALL_FUNCTION_VECTOR;
 577                 break;
 578         case CALL_FUNCTION_SINGLE_VECTOR:
 579                 xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
 580                 break;
 581         case IRQ_WORK_VECTOR:
 582                 xen_vector = XEN_IRQ_WORK_VECTOR;
 583                 break;
 584 #ifdef CONFIG_X86_64
 585         case NMI_VECTOR:
 586         case APIC_DM_NMI: /* Some use that instead of NMI_VECTOR */
 587                 xen_vector = XEN_NMI_VECTOR;
 588                 break;
 589 #endif
 590         default:
 591                 xen_vector = -1;
 592                 printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
 593                         vector);
 594         }
 595
 596         return xen_vector;
 597 }
 598
 599 void xen_send_IPI_mask(const struct cpumask *mask,
 600                               int vector)
 601 {
 602         int xen_vector = xen_map_vector(vector);
 603
 604         if (xen_vector >= 0)
 605                 __xen_send_IPI_mask(mask, xen_vector);
 606 }
 607
 608 void xen_send_IPI_all(int vector)
 609 {
 610         int xen_vector = xen_map_vector(vector);
 611
 612         if (xen_vector >= 0)
 613                 __xen_send_IPI_mask(cpu_online_mask, xen_vector);
 614 }
 615
 616 void xen_send_IPI_self(int vector)
 617 {
 618         int xen_vector = xen_map_vector(vector);
 619
 620         if (xen_vector >= 0)
 621                 xen_send_IPI_one(smp_processor_id(), xen_vector);
 622 }
 623
 624 void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
 625                                 int vector)
 626 {
 627         unsigned cpu;
 628         unsigned int this_cpu = smp_processor_id();
 629         int xen_vector = xen_map_vector(vector);
 630
 631         if (!(num_online_cpus() > 1) || (xen_vector < 0))
 632                 return;
 633
 634         for_each_cpu_and(cpu, mask, cpu_online_mask) {
 635                 if (this_cpu == cpu)
 636                         continue;
 637
 638                 xen_send_IPI_one(cpu, xen_vector);
 639         }
 640 }
 641
 642 void xen_send_IPI_allbutself(int vector)
 643 {
 644         xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
 645 }
 646
 647 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
 648 {
 649         irq_enter();
 650         generic_smp_call_function_interrupt();
 651         inc_irq_stat(irq_call_count);
 652         irq_exit();
 653
 654         return IRQ_HANDLED;
 655 }
 656
 657 static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
 658 {
 659         irq_enter();
 660         generic_smp_call_function_single_interrupt();
 661         inc_irq_stat(irq_call_count);
 662         irq_exit();
 663
 664         return IRQ_HANDLED;
 665 }
 666
 667 static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id)
 668 {
 669         irq_enter();
 670         irq_work_run();
 671         inc_irq_stat(apic_irq_work_irqs);
 672         irq_exit();
 673
 674         return IRQ_HANDLED;
 675 }
 676
 677 static const struct smp_ops xen_smp_ops __initconst = {
 678         .smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
 679         .smp_prepare_cpus = xen_smp_prepare_cpus,
 680         .smp_cpus_done = xen_smp_cpus_done,
 681
 682         .cpu_up = xen_cpu_up,
 683         .cpu_die = xen_cpu_die,
 684         .cpu_disable = xen_cpu_disable,
 685         .play_dead = xen_play_dead,
 686
 687         .stop_other_cpus = xen_stop_other_cpus,
 688         .smp_send_reschedule = xen_smp_send_reschedule,
 689
 690         .send_call_func_ipi = xen_smp_send_call_function_ipi,
 691         .send_call_func_single_ipi = xen_smp_send_call_function_single_ipi,
 692 };
 693
 694 void __init xen_smp_init(void)
 695 {
 696         smp_ops = xen_smp_ops;
 697         xen_fill_possible_map();
 698 }
 699
 700 static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
 701 {
 702         native_smp_prepare_cpus(max_cpus);
 703         WARN_ON(xen_smp_intr_init(0));
 704
 705         xen_init_lock_cpu(0);
 706 }
 707
 708 static int xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle)
 709 {
 710         int rc;
 711         /*
 712          * xen_smp_intr_init() needs to run before native_cpu_up()
 713          * so that IPI vectors are set up on the booting CPU before
 714          * it is marked online in native_cpu_up().
 715         */
 716         rc = xen_smp_intr_init(cpu);
 717         WARN_ON(rc);
 718         if (!rc)
 719                 rc =  native_cpu_up(cpu, tidle);
 720
 721         /*
 722          * We must initialize the slowpath CPU kicker _after_ the native
 723          * path has executed. If we initialized it before none of the
 724          * unlocker IPI kicks would reach the booting CPU as the booting
 725          * CPU had not set itself 'online' in cpu_online_mask. That mask
 726          * is checked when IPIs are sent (on HVM at least).
 727          */
 728         xen_init_lock_cpu(cpu);
 729         return rc;
 730 }
 731
 732 static void xen_hvm_cpu_die(unsigned int cpu)
 733 {
 734         xen_cpu_die(cpu);
 735         native_cpu_die(cpu);
 736 }
 737
 738 void __init xen_hvm_smp_init(void)
 739 {
 740         if (!xen_have_vector_callback)
 741                 return;
 742         smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
 743         smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
 744         smp_ops.cpu_up = xen_hvm_cpu_up;
 745         smp_ops.cpu_die = xen_hvm_cpu_die;
 746         smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
 747         smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;
 748         smp_ops.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu;
 749 }