arch/ia64/kernel/smpboot.c

   1 /*
   2  * SMP boot-related support
   3  *
   4  * Copyright (C) 1998-2003, 2005 Hewlett-Packard Co
   5  *      David Mosberger-Tang <davidm@hpl.hp.com>
   6  * Copyright (C) 2001, 2004-2005 Intel Corp
   7  *      Rohit Seth <rohit.seth@intel.com>
   8  *      Suresh Siddha <suresh.b.siddha@intel.com>
   9  *      Gordon Jin <gordon.jin@intel.com>
  10  *      Ashok Raj  <ashok.raj@intel.com>
  11  *
  12  * 01/05/16 Rohit Seth <rohit.seth@intel.com>   Moved SMP booting functions from smp.c to here.
  13  * 01/04/27 David Mosberger <davidm@hpl.hp.com> Added ITC synching code.
  14  * 02/07/31 David Mosberger <davidm@hpl.hp.com> Switch over to hotplug-CPU boot-sequence.
  15  *                                              smp_boot_cpus()/smp_commence() is replaced by
  16  *                                              smp_prepare_cpus()/__cpu_up()/smp_cpus_done().
  17  * 04/06/21 Ashok Raj           <ashok.raj@intel.com> Added CPU Hotplug Support
  18  * 04/12/26 Jin Gordon <gordon.jin@intel.com>
  19  * 04/12/26 Rohit Seth <rohit.seth@intel.com>
  20  *                                              Add multi-threading and multi-core detection
  21  * 05/01/30 Suresh Siddha <suresh.b.siddha@intel.com>
  22  *                                              Setup cpu_sibling_map and cpu_core_map
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/acpi.h>
  27 #include <linux/bootmem.h>
  28 #include <linux/cpu.h>
  29 #include <linux/delay.h>
  30 #include <linux/init.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/irq.h>
  33 #include <linux/kernel.h>
  34 #include <linux/kernel_stat.h>
  35 #include <linux/mm.h>
  36 #include <linux/notifier.h>
  37 #include <linux/smp.h>
  38 #include <linux/spinlock.h>
  39 #include <linux/efi.h>
  40 #include <linux/percpu.h>
  41 #include <linux/bitops.h>
  42
  43 #include <asm/atomic.h>
  44 #include <asm/cache.h>
  45 #include <asm/current.h>
  46 #include <asm/delay.h>
  47 #include <asm/io.h>
  48 #include <asm/irq.h>
  49 #include <asm/machvec.h>
  50 #include <asm/mca.h>
  51 #include <asm/page.h>
  52 #include <asm/paravirt.h>
  53 #include <asm/pgalloc.h>
  54 #include <asm/pgtable.h>
  55 #include <asm/processor.h>
  56 #include <asm/ptrace.h>
  57 #include <asm/sal.h>
  58 #include <asm/system.h>
  59 #include <asm/tlbflush.h>
  60 #include <asm/unistd.h>
  61 #include <asm/sn/arch.h>
  62
  63 #define SMP_DEBUG 0
  64
  65 #if SMP_DEBUG
  66 #define Dprintk(x...)  printk(x)
  67 #else
  68 #define Dprintk(x...)
  69 #endif
  70
  71 #ifdef CONFIG_HOTPLUG_CPU
  72 #ifdef CONFIG_PERMIT_BSP_REMOVE
  73 #define bsp_remove_ok   1
  74 #else
  75 #define bsp_remove_ok   0
  76 #endif
  77
  78 /*
  79  * Store all idle threads, this can be reused instead of creating
  80  * a new thread. Also avoids complicated thread destroy functionality
  81  * for idle threads.
  82  */
  83 struct task_struct *idle_thread_array[NR_CPUS];
  84
  85 /*
  86  * Global array allocated for NR_CPUS at boot time
  87  */
  88 struct sal_to_os_boot sal_boot_rendez_state[NR_CPUS];
  89
  90 /*
  91  * start_ap in head.S uses this to store current booting cpu
  92  * info.
  93  */
  94 struct sal_to_os_boot *sal_state_for_booting_cpu = &sal_boot_rendez_state[0];
  95
  96 #define set_brendez_area(x) (sal_state_for_booting_cpu = &sal_boot_rendez_state[(x)]);
  97
  98 #define get_idle_for_cpu(x)             (idle_thread_array[(x)])
  99 #define set_idle_for_cpu(x,p)   (idle_thread_array[(x)] = (p))
 100
 101 #else
 102
 103 #define get_idle_for_cpu(x)             (NULL)
 104 #define set_idle_for_cpu(x,p)
 105 #define set_brendez_area(x)
 106 #endif
 107
 108
 109 /*
 110  * ITC synchronization related stuff:
 111  */
 112 #define MASTER  (0)
 113 #define SLAVE   (SMP_CACHE_BYTES/8)
 114
 115 #define NUM_ROUNDS      64      /* magic value */
 116 #define NUM_ITERS       5       /* likewise */
 117
 118 static DEFINE_SPINLOCK(itc_sync_lock);
 119 static volatile unsigned long go[SLAVE + 1];
 120
 121 #define DEBUG_ITC_SYNC  0
 122
 123 extern void start_ap (void);
 124 extern unsigned long ia64_iobase;
 125
 126 struct task_struct *task_for_booting_cpu;
 127
 128 /*
 129  * State for each CPU
 130  */
 131 DEFINE_PER_CPU(int, cpu_state);
 132
 133 cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
 134 EXPORT_SYMBOL(cpu_core_map);
 135 DEFINE_PER_CPU_SHARED_ALIGNED(cpumask_t, cpu_sibling_map);
 136 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
 137
 138 int smp_num_siblings = 1;
 139
 140 /* which logical CPU number maps to which CPU (physical APIC ID) */
 141 volatile int ia64_cpu_to_sapicid[NR_CPUS];
 142 EXPORT_SYMBOL(ia64_cpu_to_sapicid);
 143
 144 static volatile cpumask_t cpu_callin_map;
 145
 146 struct smp_boot_data smp_boot_data __initdata;
 147
 148 unsigned long ap_wakeup_vector = -1; /* External Int use to wakeup APs */
 149
 150 char __initdata no_int_routing;
 151
 152 unsigned char smp_int_redirect; /* are INT and IPI redirectable by the chipset? */
 153
 154 #ifdef CONFIG_FORCE_CPEI_RETARGET
 155 #define CPEI_OVERRIDE_DEFAULT   (1)
 156 #else
 157 #define CPEI_OVERRIDE_DEFAULT   (0)
 158 #endif
 159
 160 unsigned int force_cpei_retarget = CPEI_OVERRIDE_DEFAULT;
 161
 162 static int __init
 163 cmdl_force_cpei(char *str)
 164 {
 165         int value=0;
 166
 167         get_option (&str, &value);
 168         force_cpei_retarget = value;
 169
 170         return 1;
 171 }
 172
 173 __setup("force_cpei=", cmdl_force_cpei);
 174
 175 static int __init
 176 nointroute (char *str)
 177 {
 178         no_int_routing = 1;
 179         printk ("no_int_routing on\n");
 180         return 1;
 181 }
 182
 183 __setup("nointroute", nointroute);
 184
 185 static void fix_b0_for_bsp(void)
 186 {
 187 #ifdef CONFIG_HOTPLUG_CPU
 188         int cpuid;
 189         static int fix_bsp_b0 = 1;
 190
 191         cpuid = smp_processor_id();
 192
 193         /*
 194          * Cache the b0 value on the first AP that comes up
 195          */
 196         if (!(fix_bsp_b0 && cpuid))
 197                 return;
 198
 199         sal_boot_rendez_state[0].br[0] = sal_boot_rendez_state[cpuid].br[0];
 200         printk ("Fixed BSP b0 value from CPU %d\n", cpuid);
 201
 202         fix_bsp_b0 = 0;
 203 #endif
 204 }
 205
 206 void
 207 sync_master (void *arg)
 208 {
 209         unsigned long flags, i;
 210
 211         go[MASTER] = 0;
 212
 213         local_irq_save(flags);
 214         {
 215                 for (i = 0; i < NUM_ROUNDS*NUM_ITERS; ++i) {
 216                         while (!go[MASTER])
 217                                 cpu_relax();
 218                         go[MASTER] = 0;
 219                         go[SLAVE] = ia64_get_itc();
 220                 }
 221         }
 222         local_irq_restore(flags);
 223 }
 224
 225 /*
 226  * Return the number of cycles by which our itc differs from the itc on the master
 227  * (time-keeper) CPU.  A positive number indicates our itc is ahead of the master,
 228  * negative that it is behind.
 229  */
 230 static inline long
 231 get_delta (long *rt, long *master)
 232 {
 233         unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0;
 234         unsigned long tcenter, t0, t1, tm;
 235         long i;
 236
 237         for (i = 0; i < NUM_ITERS; ++i) {
 238                 t0 = ia64_get_itc();
 239                 go[MASTER] = 1;
 240                 while (!(tm = go[SLAVE]))
 241                         cpu_relax();
 242                 go[SLAVE] = 0;
 243                 t1 = ia64_get_itc();
 244
 245                 if (t1 - t0 < best_t1 - best_t0)
 246                         best_t0 = t0, best_t1 = t1, best_tm = tm;
 247         }
 248
 249         *rt = best_t1 - best_t0;
 250         *master = best_tm - best_t0;
 251
 252         /* average best_t0 and best_t1 without overflow: */
 253         tcenter = (best_t0/2 + best_t1/2);
 254         if (best_t0 % 2 + best_t1 % 2 == 2)
 255                 ++tcenter;
 256         return tcenter - best_tm;
 257 }
 258
 259 /*
 260  * Synchronize ar.itc of the current (slave) CPU with the ar.itc of the MASTER CPU
 261  * (normally the time-keeper CPU).  We use a closed loop to eliminate the possibility of
 262  * unaccounted-for errors (such as getting a machine check in the middle of a calibration
 263  * step).  The basic idea is for the slave to ask the master what itc value it has and to
 264  * read its own itc before and after the master responds.  Each iteration gives us three
 265  * timestamps:
 266  *
 267  *      slave           master
 268  *
 269  *      t0 ---\
 270  *             ---\
 271  *                 --->
 272  *                      tm
 273  *                 /---
 274  *             /---
 275  *      t1 <---
 276  *
 277  *
 278  * The goal is to adjust the slave's ar.itc such that tm falls exactly half-way between t0
 279  * and t1.  If we achieve this, the clocks are synchronized provided the interconnect
 280  * between the slave and the master is symmetric.  Even if the interconnect were
 281  * asymmetric, we would still know that the synchronization error is smaller than the
 282  * roundtrip latency (t0 - t1).
 283  *
 284  * When the interconnect is quiet and symmetric, this lets us synchronize the itc to
 285  * within one or two cycles.  However, we can only *guarantee* that the synchronization is
 286  * accurate to within a round-trip time, which is typically in the range of several
 287  * hundred cycles (e.g., ~500 cycles).  In practice, this means that the itc's are usually
 288  * almost perfectly synchronized, but we shouldn't assume that the accuracy is much better
 289  * than half a micro second or so.
 290  */
 291 void
 292 ia64_sync_itc (unsigned int master)
 293 {
 294         long i, delta, adj, adjust_latency = 0, done = 0;
 295         unsigned long flags, rt, master_time_stamp, bound;
 296 #if DEBUG_ITC_SYNC
 297         struct {
 298                 long rt;        /* roundtrip time */
 299                 long master;    /* master's timestamp */
 300                 long diff;      /* difference between midpoint and master's timestamp */
 301                 long lat;       /* estimate of itc adjustment latency */
 302         } t[NUM_ROUNDS];
 303 #endif
 304
 305         /*
 306          * Make sure local timer ticks are disabled while we sync.  If
 307          * they were enabled, we'd have to worry about nasty issues
 308          * like setting the ITC ahead of (or a long time before) the
 309          * next scheduled tick.
 310          */
 311         BUG_ON((ia64_get_itv() & (1 << 16)) == 0);
 312
 313         go[MASTER] = 1;
 314
 315         if (smp_call_function_single(master, sync_master, NULL, 0) < 0) {
 316                 printk(KERN_ERR "sync_itc: failed to get attention of CPU %u!\n", master);
 317                 return;
 318         }
 319
 320         while (go[MASTER])
 321                 cpu_relax();    /* wait for master to be ready */
 322
 323         spin_lock_irqsave(&itc_sync_lock, flags);
 324         {
 325                 for (i = 0; i < NUM_ROUNDS; ++i) {
 326                         delta = get_delta(&rt, &master_time_stamp);
 327                         if (delta == 0) {
 328                                 done = 1;       /* let's lock on to this... */
 329                                 bound = rt;
 330                         }
 331
 332                         if (!done) {
 333                                 if (i > 0) {
 334                                         adjust_latency += -delta;
 335                                         adj = -delta + adjust_latency/4;
 336                                 } else
 337                                         adj = -delta;
 338
 339                                 ia64_set_itc(ia64_get_itc() + adj);
 340                         }
 341 #if DEBUG_ITC_SYNC
 342                         t[i].rt = rt;
 343                         t[i].master = master_time_stamp;
 344                         t[i].diff = delta;
 345                         t[i].lat = adjust_latency/4;
 346 #endif
 347                 }
 348         }
 349         spin_unlock_irqrestore(&itc_sync_lock, flags);
 350
 351 #if DEBUG_ITC_SYNC
 352         for (i = 0; i < NUM_ROUNDS; ++i)
 353                 printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n",
 354                        t[i].rt, t[i].master, t[i].diff, t[i].lat);
 355 #endif
 356
 357         printk(KERN_INFO "CPU %d: synchronized ITC with CPU %u (last diff %ld cycles, "
 358                "maxerr %lu cycles)\n", smp_processor_id(), master, delta, rt);
 359 }
 360
 361 /*
 362  * Ideally sets up per-cpu profiling hooks.  Doesn't do much now...
 363  */
 364 static inline void __devinit
 365 smp_setup_percpu_timer (void)
 366 {
 367 }
 368
 369 static void __cpuinit
 370 smp_callin (void)
 371 {
 372         int cpuid, phys_id, itc_master;
 373         struct cpuinfo_ia64 *last_cpuinfo, *this_cpuinfo;
 374         extern void ia64_init_itm(void);
 375         extern volatile int time_keeper_id;
 376
 377 #ifdef CONFIG_PERFMON
 378         extern void pfm_init_percpu(void);
 379 #endif
 380
 381         cpuid = smp_processor_id();
 382         phys_id = hard_smp_processor_id();
 383         itc_master = time_keeper_id;
 384
 385         if (cpu_online(cpuid)) {
 386                 printk(KERN_ERR "huh, phys CPU#0x%x, CPU#0x%x already present??\n",
 387                        phys_id, cpuid);
 388                 BUG();
 389         }
 390
 391         fix_b0_for_bsp();
 392
 393         /*
 394          * numa_node_id() works after this.
 395          */
 396         set_numa_node(cpu_to_node_map[cpuid]);
 397
 398         ipi_call_lock_irq();
 399         spin_lock(&vector_lock);
 400         /* Setup the per cpu irq handling data structures */
 401         __setup_vector_irq(cpuid);
 402         notify_cpu_starting(cpuid);
 403         cpu_set(cpuid, cpu_online_map);
 404         per_cpu(cpu_state, cpuid) = CPU_ONLINE;
 405         spin_unlock(&vector_lock);
 406         ipi_call_unlock_irq();
 407
 408         smp_setup_percpu_timer();
 409
 410         ia64_mca_cmc_vector_setup();    /* Setup vector on AP */
 411
 412 #ifdef CONFIG_PERFMON
 413         pfm_init_percpu();
 414 #endif
 415
 416         local_irq_enable();
 417
 418         if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
 419                 /*
 420                  * Synchronize the ITC with the BP.  Need to do this after irqs are
 421                  * enabled because ia64_sync_itc() calls smp_call_function_single(), which
 422                  * calls spin_unlock_bh(), which calls spin_unlock_bh(), which calls
 423                  * local_bh_enable(), which bugs out if irqs are not enabled...
 424                  */
 425                 Dprintk("Going to syncup ITC with ITC Master.\n");
 426                 ia64_sync_itc(itc_master);
 427         }
 428
 429         /*
 430          * Get our bogomips.
 431          */
 432         ia64_init_itm();
 433
 434         /*
 435          * Delay calibration can be skipped if new processor is identical to the
 436          * previous processor.
 437          */
 438         last_cpuinfo = cpu_data(cpuid - 1);
 439         this_cpuinfo = local_cpu_data;
 440         if (last_cpuinfo->itc_freq != this_cpuinfo->itc_freq ||
 441             last_cpuinfo->proc_freq != this_cpuinfo->proc_freq ||
 442             last_cpuinfo->features != this_cpuinfo->features ||
 443             last_cpuinfo->revision != this_cpuinfo->revision ||
 444             last_cpuinfo->family != this_cpuinfo->family ||
 445             last_cpuinfo->archrev != this_cpuinfo->archrev ||
 446             last_cpuinfo->model != this_cpuinfo->model)
 447                 calibrate_delay();
 448         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 449
 450         /*
 451          * Allow the master to continue.
 452          */
 453         cpu_set(cpuid, cpu_callin_map);
 454         Dprintk("Stack on CPU %d at about %p\n",cpuid, &cpuid);
 455 }
 456
 457
 458 /*
 459  * Activate a secondary processor.  head.S calls this.
 460  */
 461 int __cpuinit
 462 start_secondary (void *unused)
 463 {
 464         /* Early console may use I/O ports */
 465         ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
 466 #ifndef CONFIG_PRINTK_TIME
 467         Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id());
 468 #endif
 469         efi_map_pal_code();
 470         cpu_init();
 471         preempt_disable();
 472         smp_callin();
 473
 474         cpu_idle();
 475         return 0;
 476 }
 477
 478 struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
 479 {
 480         return NULL;
 481 }
 482
 483 struct create_idle {
 484         struct work_struct work;
 485         struct task_struct *idle;
 486         struct completion done;
 487         int cpu;
 488 };
 489
 490 void __cpuinit
 491 do_fork_idle(struct work_struct *work)
 492 {
 493         struct create_idle *c_idle =
 494                 container_of(work, struct create_idle, work);
 495
 496         c_idle->idle = fork_idle(c_idle->cpu);
 497         complete(&c_idle->done);
 498 }
 499
 500 static int __cpuinit
 501 do_boot_cpu (int sapicid, int cpu)
 502 {
 503         int timeout;
 504         struct create_idle c_idle = {
 505                 .work = __WORK_INITIALIZER(c_idle.work, do_fork_idle),
 506                 .cpu    = cpu,
 507                 .done   = COMPLETION_INITIALIZER(c_idle.done),
 508         };
 509
 510         c_idle.idle = get_idle_for_cpu(cpu);
 511         if (c_idle.idle) {
 512                 init_idle(c_idle.idle, cpu);
 513                 goto do_rest;
 514         }
 515
 516         /*
 517          * We can't use kernel_thread since we must avoid to reschedule the child.
 518          */
 519         if (!keventd_up() || current_is_keventd())
 520                 c_idle.work.func(&c_idle.work);
 521         else {
 522                 schedule_work(&c_idle.work);
 523                 wait_for_completion(&c_idle.done);
 524         }
 525
 526         if (IS_ERR(c_idle.idle))
 527                 panic("failed fork for CPU %d", cpu);
 528
 529         set_idle_for_cpu(cpu, c_idle.idle);
 530
 531 do_rest:
 532         task_for_booting_cpu = c_idle.idle;
 533
 534         Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
 535
 536         set_brendez_area(cpu);
 537         platform_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0);
 538
 539         /*
 540          * Wait 10s total for the AP to start
 541          */
 542         Dprintk("Waiting on callin_map ...");
 543         for (timeout = 0; timeout < 100000; timeout++) {
 544                 if (cpu_isset(cpu, cpu_callin_map))
 545                         break;  /* It has booted */
 546                 udelay(100);
 547         }
 548         Dprintk("\n");
 549
 550         if (!cpu_isset(cpu, cpu_callin_map)) {
 551                 printk(KERN_ERR "Processor 0x%x/0x%x is stuck.\n", cpu, sapicid);
 552                 ia64_cpu_to_sapicid[cpu] = -1;
 553                 cpu_clear(cpu, cpu_online_map);  /* was set in smp_callin() */
 554                 return -EINVAL;
 555         }
 556         return 0;
 557 }
 558
 559 static int __init
 560 decay (char *str)
 561 {
 562         int ticks;
 563         get_option (&str, &ticks);
 564         return 1;
 565 }
 566
 567 __setup("decay=", decay);
 568
 569 /*
 570  * Initialize the logical CPU number to SAPICID mapping
 571  */
 572 void __init
 573 smp_build_cpu_map (void)
 574 {
 575         int sapicid, cpu, i;
 576         int boot_cpu_id = hard_smp_processor_id();
 577
 578         for (cpu = 0; cpu < NR_CPUS; cpu++) {
 579                 ia64_cpu_to_sapicid[cpu] = -1;
 580         }
 581
 582         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 583         cpus_clear(cpu_present_map);
 584         set_cpu_present(0, true);
 585         set_cpu_possible(0, true);
 586         for (cpu = 1, i = 0; i < smp_boot_data.cpu_count; i++) {
 587                 sapicid = smp_boot_data.cpu_phys_id[i];
 588                 if (sapicid == boot_cpu_id)
 589                         continue;
 590                 set_cpu_present(cpu, true);
 591                 set_cpu_possible(cpu, true);
 592                 ia64_cpu_to_sapicid[cpu] = sapicid;
 593                 cpu++;
 594         }
 595 }
 596
 597 /*
 598  * Cycle through the APs sending Wakeup IPIs to boot each.
 599  */
 600 void __init
 601 smp_prepare_cpus (unsigned int max_cpus)
 602 {
 603         int boot_cpu_id = hard_smp_processor_id();
 604
 605         /*
 606          * Initialize the per-CPU profiling counter/multiplier
 607          */
 608
 609         smp_setup_percpu_timer();
 610
 611         /*
 612          * We have the boot CPU online for sure.
 613          */
 614         cpu_set(0, cpu_online_map);
 615         cpu_set(0, cpu_callin_map);
 616
 617         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 618         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 619
 620         printk(KERN_INFO "Boot processor id 0x%x/0x%x\n", 0, boot_cpu_id);
 621
 622         current_thread_info()->cpu = 0;
 623
 624         /*
 625          * If SMP should be disabled, then really disable it!
 626          */
 627         if (!max_cpus) {
 628                 printk(KERN_INFO "SMP mode deactivated.\n");
 629                 init_cpu_online(cpumask_of(0));
 630                 init_cpu_present(cpumask_of(0));
 631                 init_cpu_possible(cpumask_of(0));
 632                 return;
 633         }
 634 }
 635
 636 void __devinit smp_prepare_boot_cpu(void)
 637 {
 638         cpu_set(smp_processor_id(), cpu_online_map);
 639         cpu_set(smp_processor_id(), cpu_callin_map);
 640         set_numa_node(cpu_to_node_map[smp_processor_id()]);
 641         per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
 642         paravirt_post_smp_prepare_boot_cpu();
 643 }
 644
 645 #ifdef CONFIG_HOTPLUG_CPU
 646 static inline void
 647 clear_cpu_sibling_map(int cpu)
 648 {
 649         int i;
 650
 651         for_each_cpu_mask(i, per_cpu(cpu_sibling_map, cpu))
 652                 cpu_clear(cpu, per_cpu(cpu_sibling_map, i));
 653         for_each_cpu_mask(i, cpu_core_map[cpu])
 654                 cpu_clear(cpu, cpu_core_map[i]);
 655
 656         per_cpu(cpu_sibling_map, cpu) = cpu_core_map[cpu] = CPU_MASK_NONE;
 657 }
 658
 659 static void
 660 remove_siblinginfo(int cpu)
 661 {
 662         int last = 0;
 663
 664         if (cpu_data(cpu)->threads_per_core == 1 &&
 665             cpu_data(cpu)->cores_per_socket == 1) {
 666                 cpu_clear(cpu, cpu_core_map[cpu]);
 667                 cpu_clear(cpu, per_cpu(cpu_sibling_map, cpu));
 668                 return;
 669         }
 670
 671         last = (cpus_weight(cpu_core_map[cpu]) == 1 ? 1 : 0);
 672
 673         /* remove it from all sibling map's */
 674         clear_cpu_sibling_map(cpu);
 675 }
 676
 677 extern void fixup_irqs(void);
 678
 679 int migrate_platform_irqs(unsigned int cpu)
 680 {
 681         int new_cpei_cpu;
 682         struct irq_desc *desc = NULL;
 683         const struct cpumask *mask;
 684         int             retval = 0;
 685
 686         /*
 687          * dont permit CPEI target to removed.
 688          */
 689         if (cpe_vector > 0 && is_cpu_cpei_target(cpu)) {
 690                 printk ("CPU (%d) is CPEI Target\n", cpu);
 691                 if (can_cpei_retarget()) {
 692                         /*
 693                          * Now re-target the CPEI to a different processor
 694                          */
 695                         new_cpei_cpu = any_online_cpu(cpu_online_map);
 696                         mask = cpumask_of(new_cpei_cpu);
 697                         set_cpei_target_cpu(new_cpei_cpu);
 698                         desc = irq_desc + ia64_cpe_irq;
 699                         /*
 700                          * Switch for now, immediately, we need to do fake intr
 701                          * as other interrupts, but need to study CPEI behaviour with
 702                          * polling before making changes.
 703                          */
 704                         if (desc) {
 705                                 desc->chip->disable(ia64_cpe_irq);
 706                                 desc->chip->set_affinity(ia64_cpe_irq, mask);
 707                                 desc->chip->enable(ia64_cpe_irq);
 708                                 printk ("Re-targetting CPEI to cpu %d\n", new_cpei_cpu);
 709                         }
 710                 }
 711                 if (!desc) {
 712                         printk ("Unable to retarget CPEI, offline cpu [%d] failed\n", cpu);
 713                         retval = -EBUSY;
 714                 }
 715         }
 716         return retval;
 717 }
 718
 719 /* must be called with cpucontrol mutex held */
 720 int __cpu_disable(void)
 721 {
 722         int cpu = smp_processor_id();
 723
 724         /*
 725          * dont permit boot processor for now
 726          */
 727         if (cpu == 0 && !bsp_remove_ok) {
 728                 printk ("Your platform does not support removal of BSP\n");
 729                 return (-EBUSY);
 730         }
 731
 732         if (ia64_platform_is("sn2")) {
 733                 if (!sn_cpu_disable_allowed(cpu))
 734                         return -EBUSY;
 735         }
 736
 737         cpu_clear(cpu, cpu_online_map);
 738
 739         if (migrate_platform_irqs(cpu)) {
 740                 cpu_set(cpu, cpu_online_map);
 741                 return -EBUSY;
 742         }
 743
 744         remove_siblinginfo(cpu);
 745         fixup_irqs();
 746         local_flush_tlb_all();
 747         cpu_clear(cpu, cpu_callin_map);
 748         return 0;
 749 }
 750
 751 void __cpu_die(unsigned int cpu)
 752 {
 753         unsigned int i;
 754
 755         for (i = 0; i < 100; i++) {
 756                 /* They ack this in play_dead by setting CPU_DEAD */
 757                 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
 758                 {
 759                         printk ("CPU %d is now offline\n", cpu);
 760                         return;
 761                 }
 762                 msleep(100);
 763         }
 764         printk(KERN_ERR "CPU %u didn't die...\n", cpu);
 765 }
 766 #endif /* CONFIG_HOTPLUG_CPU */
 767
 768 void
 769 smp_cpus_done (unsigned int dummy)
 770 {
 771         int cpu;
 772         unsigned long bogosum = 0;
 773
 774         /*
 775          * Allow the user to impress friends.
 776          */
 777
 778         for_each_online_cpu(cpu) {
 779                 bogosum += cpu_data(cpu)->loops_per_jiffy;
 780         }
 781
 782         printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
 783                (int)num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100);
 784 }
 785
 786 static inline void __devinit
 787 set_cpu_sibling_map(int cpu)
 788 {
 789         int i;
 790
 791         for_each_online_cpu(i) {
 792                 if ((cpu_data(cpu)->socket_id == cpu_data(i)->socket_id)) {
 793                         cpu_set(i, cpu_core_map[cpu]);
 794                         cpu_set(cpu, cpu_core_map[i]);
 795                         if (cpu_data(cpu)->core_id == cpu_data(i)->core_id) {
 796                                 cpu_set(i, per_cpu(cpu_sibling_map, cpu));
 797                                 cpu_set(cpu, per_cpu(cpu_sibling_map, i));
 798                         }
 799                 }
 800         }
 801 }
 802
 803 int __cpuinit
 804 __cpu_up (unsigned int cpu)
 805 {
 806         int ret;
 807         int sapicid;
 808
 809         sapicid = ia64_cpu_to_sapicid[cpu];
 810         if (sapicid == -1)
 811                 return -EINVAL;
 812
 813         /*
 814          * Already booted cpu? not valid anymore since we dont
 815          * do idle loop tightspin anymore.
 816          */
 817         if (cpu_isset(cpu, cpu_callin_map))
 818                 return -EINVAL;
 819
 820         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 821         /* Processor goes to start_secondary(), sets online flag */
 822         ret = do_boot_cpu(sapicid, cpu);
 823         if (ret < 0)
 824                 return ret;
 825
 826         if (cpu_data(cpu)->threads_per_core == 1 &&
 827             cpu_data(cpu)->cores_per_socket == 1) {
 828                 cpu_set(cpu, per_cpu(cpu_sibling_map, cpu));
 829                 cpu_set(cpu, cpu_core_map[cpu]);
 830                 return 0;
 831         }
 832
 833         set_cpu_sibling_map(cpu);
 834
 835         return 0;
 836 }
 837
 838 /*
 839  * Assume that CPUs have been discovered by some platform-dependent interface.  For
 840  * SoftSDV/Lion, that would be ACPI.
 841  *
 842  * Setup of the IPI irq handler is done in irq.c:init_IRQ_SMP().
 843  */
 844 void __init
 845 init_smp_config(void)
 846 {
 847         struct fptr {
 848                 unsigned long fp;
 849                 unsigned long gp;
 850         } *ap_startup;
 851         long sal_ret;
 852
 853         /* Tell SAL where to drop the APs.  */
 854         ap_startup = (struct fptr *) start_ap;
 855         sal_ret = ia64_sal_set_vectors(SAL_VECTOR_OS_BOOT_RENDEZ,
 856                                        ia64_tpa(ap_startup->fp), ia64_tpa(ap_startup->gp), 0, 0, 0, 0);
 857         if (sal_ret < 0)
 858                 printk(KERN_ERR "SMP: Can't set SAL AP Boot Rendezvous: %s\n",
 859                        ia64_sal_strerror(sal_ret));
 860 }
 861
 862 /*
 863  * identify_siblings(cpu) gets called from identify_cpu. This populates the
 864  * information related to logical execution units in per_cpu_data structure.
 865  */
 866 void __devinit
 867 identify_siblings(struct cpuinfo_ia64 *c)
 868 {
 869         long status;
 870         u16 pltid;
 871         pal_logical_to_physical_t info;
 872
 873         status = ia64_pal_logical_to_phys(-1, &info);
 874         if (status != PAL_STATUS_SUCCESS) {
 875                 if (status != PAL_STATUS_UNIMPLEMENTED) {
 876                         printk(KERN_ERR
 877                                 "ia64_pal_logical_to_phys failed with %ld\n",
 878                                 status);
 879                         return;
 880                 }
 881
 882                 info.overview_ppid = 0;
 883                 info.overview_cpp  = 1;
 884                 info.overview_tpc  = 1;
 885         }
 886
 887         status = ia64_sal_physical_id_info(&pltid);
 888         if (status != PAL_STATUS_SUCCESS) {
 889                 if (status != PAL_STATUS_UNIMPLEMENTED)
 890                         printk(KERN_ERR
 891                                 "ia64_sal_pltid failed with %ld\n",
 892                                 status);
 893                 return;
 894         }
 895
 896         c->socket_id =  (pltid << 8) | info.overview_ppid;
 897
 898         if (info.overview_cpp == 1 && info.overview_tpc == 1)
 899                 return;
 900
 901         c->cores_per_socket = info.overview_cpp;
 902         c->threads_per_core = info.overview_tpc;
 903         c->num_log = info.overview_num_log;
 904
 905         c->core_id = info.log1_cid;
 906         c->thread_id = info.log1_tid;
 907 }
 908
 909 /*
 910  * returns non zero, if multi-threading is enabled
 911  * on at least one physical package. Due to hotplug cpu
 912  * and (maxcpus=), all threads may not necessarily be enabled
 913  * even though the processor supports multi-threading.
 914  */
 915 int is_multithreading_enabled(void)
 916 {
 917         int i, j;
 918
 919         for_each_present_cpu(i) {
 920                 for_each_present_cpu(j) {
 921                         if (j == i)
 922                                 continue;
 923                         if ((cpu_data(j)->socket_id == cpu_data(i)->socket_id)) {
 924                                 if (cpu_data(j)->core_id == cpu_data(i)->core_id)
 925                                         return 1;
 926                         }
 927                 }
 928         }
 929         return 0;
 930 }
 931 EXPORT_SYMBOL_GPL(is_multithreading_enabled);