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