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 #include <linux/config.h>
  25
  26 #include <linux/module.h>
  27 #include <linux/acpi.h>
  28 #include <linux/bootmem.h>
  29 #include <linux/cpu.h>
  30 #include <linux/delay.h>
  31 #include <linux/init.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/irq.h>
  34 #include <linux/kernel.h>
  35 #include <linux/kernel_stat.h>
  36 #include <linux/mm.h>
  37 #include <linux/notifier.h>
  38 #include <linux/smp.h>
  39 #include <linux/smp_lock.h>
  40 #include <linux/spinlock.h>
  41 #include <linux/efi.h>
  42 #include <linux/percpu.h>
  43 #include <linux/bitops.h>
  44
  45 #include <asm/atomic.h>
  46 #include <asm/cache.h>
  47 #include <asm/current.h>
  48 #include <asm/delay.h>
  49 #include <asm/ia32.h>
  50 #include <asm/io.h>
  51 #include <asm/irq.h>
  52 #include <asm/machvec.h>
  53 #include <asm/mca.h>
  54 #include <asm/page.h>
  55 #include <asm/pgalloc.h>
  56 #include <asm/pgtable.h>
  57 #include <asm/processor.h>
  58 #include <asm/ptrace.h>
  59 #include <asm/sal.h>
  60 #include <asm/system.h>
  61 #include <asm/tlbflush.h>
  62 #include <asm/unistd.h>
  63
  64 #define SMP_DEBUG 0
  65
  66 #if SMP_DEBUG
  67 #define Dprintk(x...)  printk(x)
  68 #else
  69 #define Dprintk(x...)
  70 #endif
  71
  72 #ifdef CONFIG_HOTPLUG_CPU
  73 /*
  74  * Store all idle threads, this can be reused instead of creating
  75  * a new thread. Also avoids complicated thread destroy functionality
  76  * for idle threads.
  77  */
  78 struct task_struct *idle_thread_array[NR_CPUS];
  79
  80 /*
  81  * Global array allocated for NR_CPUS at boot time
  82  */
  83 struct sal_to_os_boot sal_boot_rendez_state[NR_CPUS];
  84
  85 /*
  86  * start_ap in head.S uses this to store current booting cpu
  87  * info.
  88  */
  89 struct sal_to_os_boot *sal_state_for_booting_cpu = &sal_boot_rendez_state[0];
  90
  91 #define set_brendez_area(x) (sal_state_for_booting_cpu = &sal_boot_rendez_state[(x)]);
  92
  93 #define get_idle_for_cpu(x)             (idle_thread_array[(x)])
  94 #define set_idle_for_cpu(x,p)   (idle_thread_array[(x)] = (p))
  95
  96 #else
  97
  98 #define get_idle_for_cpu(x)             (NULL)
  99 #define set_idle_for_cpu(x,p)
 100 #define set_brendez_area(x)
 101 #endif
 102
 103
 104 /*
 105  * ITC synchronization related stuff:
 106  */
 107 #define MASTER  0
 108 #define SLAVE   (SMP_CACHE_BYTES/8)
 109
 110 #define NUM_ROUNDS      64      /* magic value */
 111 #define NUM_ITERS       5       /* likewise */
 112
 113 static DEFINE_SPINLOCK(itc_sync_lock);
 114 static volatile unsigned long go[SLAVE + 1];
 115
 116 #define DEBUG_ITC_SYNC  0
 117
 118 extern void __devinit calibrate_delay (void);
 119 extern void start_ap (void);
 120 extern unsigned long ia64_iobase;
 121
 122 task_t *task_for_booting_cpu;
 123
 124 /*
 125  * State for each CPU
 126  */
 127 DEFINE_PER_CPU(int, cpu_state);
 128
 129 /* Bitmasks of currently online, and possible CPUs */
 130 cpumask_t cpu_online_map;
 131 EXPORT_SYMBOL(cpu_online_map);
 132 cpumask_t cpu_possible_map;
 133 EXPORT_SYMBOL(cpu_possible_map);
 134
 135 cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
 136 cpumask_t cpu_sibling_map[NR_CPUS] __cacheline_aligned;
 137 int smp_num_siblings = 1;
 138 int smp_num_cpucores = 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 static int __init
 155 nointroute (char *str)
 156 {
 157         no_int_routing = 1;
 158         printk ("no_int_routing on\n");
 159         return 1;
 160 }
 161
 162 __setup("nointroute", nointroute);
 163
 164 void
 165 sync_master (void *arg)
 166 {
 167         unsigned long flags, i;
 168
 169         go[MASTER] = 0;
 170
 171         local_irq_save(flags);
 172         {
 173                 for (i = 0; i < NUM_ROUNDS*NUM_ITERS; ++i) {
 174                         while (!go[MASTER])
 175                                 cpu_relax();
 176                         go[MASTER] = 0;
 177                         go[SLAVE] = ia64_get_itc();
 178                 }
 179         }
 180         local_irq_restore(flags);
 181 }
 182
 183 /*
 184  * Return the number of cycles by which our itc differs from the itc on the master
 185  * (time-keeper) CPU.  A positive number indicates our itc is ahead of the master,
 186  * negative that it is behind.
 187  */
 188 static inline long
 189 get_delta (long *rt, long *master)
 190 {
 191         unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0;
 192         unsigned long tcenter, t0, t1, tm;
 193         long i;
 194
 195         for (i = 0; i < NUM_ITERS; ++i) {
 196                 t0 = ia64_get_itc();
 197                 go[MASTER] = 1;
 198                 while (!(tm = go[SLAVE]))
 199                         cpu_relax();
 200                 go[SLAVE] = 0;
 201                 t1 = ia64_get_itc();
 202
 203                 if (t1 - t0 < best_t1 - best_t0)
 204                         best_t0 = t0, best_t1 = t1, best_tm = tm;
 205         }
 206
 207         *rt = best_t1 - best_t0;
 208         *master = best_tm - best_t0;
 209
 210         /* average best_t0 and best_t1 without overflow: */
 211         tcenter = (best_t0/2 + best_t1/2);
 212         if (best_t0 % 2 + best_t1 % 2 == 2)
 213                 ++tcenter;
 214         return tcenter - best_tm;
 215 }
 216
 217 /*
 218  * Synchronize ar.itc of the current (slave) CPU with the ar.itc of the MASTER CPU
 219  * (normally the time-keeper CPU).  We use a closed loop to eliminate the possibility of
 220  * unaccounted-for errors (such as getting a machine check in the middle of a calibration
 221  * step).  The basic idea is for the slave to ask the master what itc value it has and to
 222  * read its own itc before and after the master responds.  Each iteration gives us three
 223  * timestamps:
 224  *
 225  *      slave           master
 226  *
 227  *      t0 ---\
 228  *             ---\
 229  *                 --->
 230  *                      tm
 231  *                 /---
 232  *             /---
 233  *      t1 <---
 234  *
 235  *
 236  * The goal is to adjust the slave's ar.itc such that tm falls exactly half-way between t0
 237  * and t1.  If we achieve this, the clocks are synchronized provided the interconnect
 238  * between the slave and the master is symmetric.  Even if the interconnect were
 239  * asymmetric, we would still know that the synchronization error is smaller than the
 240  * roundtrip latency (t0 - t1).
 241  *
 242  * When the interconnect is quiet and symmetric, this lets us synchronize the itc to
 243  * within one or two cycles.  However, we can only *guarantee* that the synchronization is
 244  * accurate to within a round-trip time, which is typically in the range of several
 245  * hundred cycles (e.g., ~500 cycles).  In practice, this means that the itc's are usually
 246  * almost perfectly synchronized, but we shouldn't assume that the accuracy is much better
 247  * than half a micro second or so.
 248  */
 249 void
 250 ia64_sync_itc (unsigned int master)
 251 {
 252         long i, delta, adj, adjust_latency = 0, done = 0;
 253         unsigned long flags, rt, master_time_stamp, bound;
 254 #if DEBUG_ITC_SYNC
 255         struct {
 256                 long rt;        /* roundtrip time */
 257                 long master;    /* master's timestamp */
 258                 long diff;      /* difference between midpoint and master's timestamp */
 259                 long lat;       /* estimate of itc adjustment latency */
 260         } t[NUM_ROUNDS];
 261 #endif
 262
 263         /*
 264          * Make sure local timer ticks are disabled while we sync.  If
 265          * they were enabled, we'd have to worry about nasty issues
 266          * like setting the ITC ahead of (or a long time before) the
 267          * next scheduled tick.
 268          */
 269         BUG_ON((ia64_get_itv() & (1 << 16)) == 0);
 270
 271         go[MASTER] = 1;
 272
 273         if (smp_call_function_single(master, sync_master, NULL, 1, 0) < 0) {
 274                 printk(KERN_ERR "sync_itc: failed to get attention of CPU %u!\n", master);
 275                 return;
 276         }
 277
 278         while (go[MASTER])
 279                 cpu_relax();    /* wait for master to be ready */
 280
 281         spin_lock_irqsave(&itc_sync_lock, flags);
 282         {
 283                 for (i = 0; i < NUM_ROUNDS; ++i) {
 284                         delta = get_delta(&rt, &master_time_stamp);
 285                         if (delta == 0) {
 286                                 done = 1;       /* let's lock on to this... */
 287                                 bound = rt;
 288                         }
 289
 290                         if (!done) {
 291                                 if (i > 0) {
 292                                         adjust_latency += -delta;
 293                                         adj = -delta + adjust_latency/4;
 294                                 } else
 295                                         adj = -delta;
 296
 297                                 ia64_set_itc(ia64_get_itc() + adj);
 298                         }
 299 #if DEBUG_ITC_SYNC
 300                         t[i].rt = rt;
 301                         t[i].master = master_time_stamp;
 302                         t[i].diff = delta;
 303                         t[i].lat = adjust_latency/4;
 304 #endif
 305                 }
 306         }
 307         spin_unlock_irqrestore(&itc_sync_lock, flags);
 308
 309 #if DEBUG_ITC_SYNC
 310         for (i = 0; i < NUM_ROUNDS; ++i)
 311                 printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n",
 312                        t[i].rt, t[i].master, t[i].diff, t[i].lat);
 313 #endif
 314
 315         printk(KERN_INFO "CPU %d: synchronized ITC with CPU %u (last diff %ld cycles, "
 316                "maxerr %lu cycles)\n", smp_processor_id(), master, delta, rt);
 317 }
 318
 319 /*
 320  * Ideally sets up per-cpu profiling hooks.  Doesn't do much now...
 321  */
 322 static inline void __devinit
 323 smp_setup_percpu_timer (void)
 324 {
 325 }
 326
 327 static void __devinit
 328 smp_callin (void)
 329 {
 330         int cpuid, phys_id;
 331         extern void ia64_init_itm(void);
 332
 333 #ifdef CONFIG_PERFMON
 334         extern void pfm_init_percpu(void);
 335 #endif
 336
 337         cpuid = smp_processor_id();
 338         phys_id = hard_smp_processor_id();
 339
 340         if (cpu_online(cpuid)) {
 341                 printk(KERN_ERR "huh, phys CPU#0x%x, CPU#0x%x already present??\n",
 342                        phys_id, cpuid);
 343                 BUG();
 344         }
 345
 346         lock_ipi_calllock();
 347         cpu_set(cpuid, cpu_online_map);
 348         unlock_ipi_calllock();
 349
 350         smp_setup_percpu_timer();
 351
 352         ia64_mca_cmc_vector_setup();    /* Setup vector on AP */
 353
 354 #ifdef CONFIG_PERFMON
 355         pfm_init_percpu();
 356 #endif
 357
 358         local_irq_enable();
 359
 360         if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
 361                 /*
 362                  * Synchronize the ITC with the BP.  Need to do this after irqs are
 363                  * enabled because ia64_sync_itc() calls smp_call_function_single(), which
 364                  * calls spin_unlock_bh(), which calls spin_unlock_bh(), which calls
 365                  * local_bh_enable(), which bugs out if irqs are not enabled...
 366                  */
 367                 Dprintk("Going to syncup ITC with BP.\n");
 368                 ia64_sync_itc(0);
 369         }
 370
 371         /*
 372          * Get our bogomips.
 373          */
 374         ia64_init_itm();
 375         calibrate_delay();
 376         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 377
 378 #ifdef CONFIG_IA32_SUPPORT
 379         ia32_gdt_init();
 380 #endif
 381
 382         /*
 383          * Allow the master to continue.
 384          */
 385         cpu_set(cpuid, cpu_callin_map);
 386         Dprintk("Stack on CPU %d at about %p\n",cpuid, &cpuid);
 387 }
 388
 389
 390 /*
 391  * Activate a secondary processor.  head.S calls this.
 392  */
 393 int __devinit
 394 start_secondary (void *unused)
 395 {
 396         /* Early console may use I/O ports */
 397         ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
 398         Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id());
 399         efi_map_pal_code();
 400         cpu_init();
 401         smp_callin();
 402
 403         cpu_idle();
 404         return 0;
 405 }
 406
 407 struct pt_regs * __devinit idle_regs(struct pt_regs *regs)
 408 {
 409         return NULL;
 410 }
 411
 412 struct create_idle {
 413         struct task_struct *idle;
 414         struct completion done;
 415         int cpu;
 416 };
 417
 418 void
 419 do_fork_idle(void *_c_idle)
 420 {
 421         struct create_idle *c_idle = _c_idle;
 422
 423         c_idle->idle = fork_idle(c_idle->cpu);
 424         complete(&c_idle->done);
 425 }
 426
 427 static int __devinit
 428 do_boot_cpu (int sapicid, int cpu)
 429 {
 430         int timeout;
 431         struct create_idle c_idle = {
 432                 .cpu    = cpu,
 433                 .done   = COMPLETION_INITIALIZER(c_idle.done),
 434         };
 435         DECLARE_WORK(work, do_fork_idle, &c_idle);
 436
 437         c_idle.idle = get_idle_for_cpu(cpu);
 438         if (c_idle.idle) {
 439                 init_idle(c_idle.idle, cpu);
 440                 goto do_rest;
 441         }
 442
 443         /*
 444          * We can't use kernel_thread since we must avoid to reschedule the child.
 445          */
 446         if (!keventd_up() || current_is_keventd())
 447                 work.func(work.data);
 448         else {
 449                 schedule_work(&work);
 450                 wait_for_completion(&c_idle.done);
 451         }
 452
 453         if (IS_ERR(c_idle.idle))
 454                 panic("failed fork for CPU %d", cpu);
 455
 456         set_idle_for_cpu(cpu, c_idle.idle);
 457
 458 do_rest:
 459         task_for_booting_cpu = c_idle.idle;
 460
 461         Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
 462
 463         set_brendez_area(cpu);
 464         platform_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0);
 465
 466         /*
 467          * Wait 10s total for the AP to start
 468          */
 469         Dprintk("Waiting on callin_map ...");
 470         for (timeout = 0; timeout < 100000; timeout++) {
 471                 if (cpu_isset(cpu, cpu_callin_map))
 472                         break;  /* It has booted */
 473                 udelay(100);
 474         }
 475         Dprintk("\n");
 476
 477         if (!cpu_isset(cpu, cpu_callin_map)) {
 478                 printk(KERN_ERR "Processor 0x%x/0x%x is stuck.\n", cpu, sapicid);
 479                 ia64_cpu_to_sapicid[cpu] = -1;
 480                 cpu_clear(cpu, cpu_online_map);  /* was set in smp_callin() */
 481                 return -EINVAL;
 482         }
 483         return 0;
 484 }
 485
 486 static int __init
 487 decay (char *str)
 488 {
 489         int ticks;
 490         get_option (&str, &ticks);
 491         return 1;
 492 }
 493
 494 __setup("decay=", decay);
 495
 496 /*
 497  * Initialize the logical CPU number to SAPICID mapping
 498  */
 499 void __init
 500 smp_build_cpu_map (void)
 501 {
 502         int sapicid, cpu, i;
 503         int boot_cpu_id = hard_smp_processor_id();
 504
 505         for (cpu = 0; cpu < NR_CPUS; cpu++) {
 506                 ia64_cpu_to_sapicid[cpu] = -1;
 507 #ifdef CONFIG_HOTPLUG_CPU
 508                 cpu_set(cpu, cpu_possible_map);
 509 #endif
 510         }
 511
 512         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 513         cpus_clear(cpu_present_map);
 514         cpu_set(0, cpu_present_map);
 515         cpu_set(0, cpu_possible_map);
 516         for (cpu = 1, i = 0; i < smp_boot_data.cpu_count; i++) {
 517                 sapicid = smp_boot_data.cpu_phys_id[i];
 518                 if (sapicid == boot_cpu_id)
 519                         continue;
 520                 cpu_set(cpu, cpu_present_map);
 521                 cpu_set(cpu, cpu_possible_map);
 522                 ia64_cpu_to_sapicid[cpu] = sapicid;
 523                 cpu++;
 524         }
 525 }
 526
 527 #ifdef CONFIG_NUMA
 528
 529 /* on which node is each logical CPU (one cacheline even for 64 CPUs) */
 530 u8 cpu_to_node_map[NR_CPUS] __cacheline_aligned;
 531 EXPORT_SYMBOL(cpu_to_node_map);
 532 /* which logical CPUs are on which nodes */
 533 cpumask_t node_to_cpu_mask[MAX_NUMNODES] __cacheline_aligned;
 534
 535 /*
 536  * Build cpu to node mapping and initialize the per node cpu masks.
 537  */
 538 void __init
 539 build_cpu_to_node_map (void)
 540 {
 541         int cpu, i, node;
 542
 543         for(node=0; node<MAX_NUMNODES; node++)
 544                 cpus_clear(node_to_cpu_mask[node]);
 545         for(cpu = 0; cpu < NR_CPUS; ++cpu) {
 546                 /*
 547                  * All Itanium NUMA platforms I know use ACPI, so maybe we
 548                  * can drop this ifdef completely.                    [EF]
 549                  */
 550 #ifdef CONFIG_ACPI_NUMA
 551                 node = -1;
 552                 for (i = 0; i < NR_CPUS; ++i)
 553                         if (cpu_physical_id(cpu) == node_cpuid[i].phys_id) {
 554                                 node = node_cpuid[i].nid;
 555                                 break;
 556                         }
 557 #else
 558 #               error Fixme: Dunno how to build CPU-to-node map.
 559 #endif
 560                 cpu_to_node_map[cpu] = (node >= 0) ? node : 0;
 561                 if (node >= 0)
 562                         cpu_set(cpu, node_to_cpu_mask[node]);
 563         }
 564 }
 565
 566 #endif /* CONFIG_NUMA */
 567
 568 /*
 569  * Cycle through the APs sending Wakeup IPIs to boot each.
 570  */
 571 void __init
 572 smp_prepare_cpus (unsigned int max_cpus)
 573 {
 574         int boot_cpu_id = hard_smp_processor_id();
 575
 576         /*
 577          * Initialize the per-CPU profiling counter/multiplier
 578          */
 579
 580         smp_setup_percpu_timer();
 581
 582         /*
 583          * We have the boot CPU online for sure.
 584          */
 585         cpu_set(0, cpu_online_map);
 586         cpu_set(0, cpu_callin_map);
 587
 588         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 589         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 590
 591         printk(KERN_INFO "Boot processor id 0x%x/0x%x\n", 0, boot_cpu_id);
 592
 593         current_thread_info()->cpu = 0;
 594
 595         /*
 596          * If SMP should be disabled, then really disable it!
 597          */
 598         if (!max_cpus) {
 599                 printk(KERN_INFO "SMP mode deactivated.\n");
 600                 cpus_clear(cpu_online_map);
 601                 cpus_clear(cpu_present_map);
 602                 cpus_clear(cpu_possible_map);
 603                 cpu_set(0, cpu_online_map);
 604                 cpu_set(0, cpu_present_map);
 605                 cpu_set(0, cpu_possible_map);
 606                 return;
 607         }
 608 }
 609
 610 void __devinit smp_prepare_boot_cpu(void)
 611 {
 612         cpu_set(smp_processor_id(), cpu_online_map);
 613         cpu_set(smp_processor_id(), cpu_callin_map);
 614 }
 615
 616 /*
 617  * mt_info[] is a temporary store for all info returned by
 618  * PAL_LOGICAL_TO_PHYSICAL, to be copied into cpuinfo_ia64 when the
 619  * specific cpu comes.
 620  */
 621 static struct {
 622         __u32   socket_id;
 623         __u16   core_id;
 624         __u16   thread_id;
 625         __u16   proc_fixed_addr;
 626         __u8    valid;
 627 } mt_info[NR_CPUS] __devinitdata;
 628
 629 #ifdef CONFIG_HOTPLUG_CPU
 630 static inline void
 631 remove_from_mtinfo(int cpu)
 632 {
 633         int i;
 634
 635         for_each_cpu(i)
 636                 if (mt_info[i].valid &&  mt_info[i].socket_id ==
 637                                                 cpu_data(cpu)->socket_id)
 638                         mt_info[i].valid = 0;
 639 }
 640
 641 static inline void
 642 clear_cpu_sibling_map(int cpu)
 643 {
 644         int i;
 645
 646         for_each_cpu_mask(i, cpu_sibling_map[cpu])
 647                 cpu_clear(cpu, cpu_sibling_map[i]);
 648         for_each_cpu_mask(i, cpu_core_map[cpu])
 649                 cpu_clear(cpu, cpu_core_map[i]);
 650
 651         cpu_sibling_map[cpu] = cpu_core_map[cpu] = CPU_MASK_NONE;
 652 }
 653
 654 static void
 655 remove_siblinginfo(int cpu)
 656 {
 657         int last = 0;
 658
 659         if (cpu_data(cpu)->threads_per_core == 1 &&
 660             cpu_data(cpu)->cores_per_socket == 1) {
 661                 cpu_clear(cpu, cpu_core_map[cpu]);
 662                 cpu_clear(cpu, cpu_sibling_map[cpu]);
 663                 return;
 664         }
 665
 666         last = (cpus_weight(cpu_core_map[cpu]) == 1 ? 1 : 0);
 667
 668         /* remove it from all sibling map's */
 669         clear_cpu_sibling_map(cpu);
 670
 671         /* if this cpu is the last in the core group, remove all its info
 672          * from mt_info structure
 673          */
 674         if (last)
 675                 remove_from_mtinfo(cpu);
 676 }
 677
 678 extern void fixup_irqs(void);
 679 /* must be called with cpucontrol mutex held */
 680 int __cpu_disable(void)
 681 {
 682         int cpu = smp_processor_id();
 683
 684         /*
 685          * dont permit boot processor for now
 686          */
 687         if (cpu == 0)
 688                 return -EBUSY;
 689
 690         remove_siblinginfo(cpu);
 691         fixup_irqs();
 692         local_flush_tlb_all();
 693         cpu_clear(cpu, cpu_callin_map);
 694         return 0;
 695 }
 696
 697 void __cpu_die(unsigned int cpu)
 698 {
 699         unsigned int i;
 700
 701         for (i = 0; i < 100; i++) {
 702                 /* They ack this in play_dead by setting CPU_DEAD */
 703                 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
 704                 {
 705                         printk ("CPU %d is now offline\n", cpu);
 706                         return;
 707                 }
 708                 msleep(100);
 709         }
 710         printk(KERN_ERR "CPU %u didn't die...\n", cpu);
 711 }
 712 #else /* !CONFIG_HOTPLUG_CPU */
 713 int __cpu_disable(void)
 714 {
 715         return -ENOSYS;
 716 }
 717
 718 void __cpu_die(unsigned int cpu)
 719 {
 720         /* We said "no" in __cpu_disable */
 721         BUG();
 722 }
 723 #endif /* CONFIG_HOTPLUG_CPU */
 724
 725 void
 726 smp_cpus_done (unsigned int dummy)
 727 {
 728         int cpu;
 729         unsigned long bogosum = 0;
 730
 731         /*
 732          * Allow the user to impress friends.
 733          */
 734
 735         for (cpu = 0; cpu < NR_CPUS; cpu++)
 736                 if (cpu_online(cpu))
 737                         bogosum += cpu_data(cpu)->loops_per_jiffy;
 738
 739         printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
 740                (int)num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100);
 741 }
 742
 743 static inline void __devinit
 744 set_cpu_sibling_map(int cpu)
 745 {
 746         int i;
 747
 748         for_each_online_cpu(i) {
 749                 if ((cpu_data(cpu)->socket_id == cpu_data(i)->socket_id)) {
 750                         cpu_set(i, cpu_core_map[cpu]);
 751                         cpu_set(cpu, cpu_core_map[i]);
 752                         if (cpu_data(cpu)->core_id == cpu_data(i)->core_id) {
 753                                 cpu_set(i, cpu_sibling_map[cpu]);
 754                                 cpu_set(cpu, cpu_sibling_map[i]);
 755                         }
 756                 }
 757         }
 758 }
 759
 760 int __devinit
 761 __cpu_up (unsigned int cpu)
 762 {
 763         int ret;
 764         int sapicid;
 765
 766         sapicid = ia64_cpu_to_sapicid[cpu];
 767         if (sapicid == -1)
 768                 return -EINVAL;
 769
 770         /*
 771          * Already booted cpu? not valid anymore since we dont
 772          * do idle loop tightspin anymore.
 773          */
 774         if (cpu_isset(cpu, cpu_callin_map))
 775                 return -EINVAL;
 776
 777         /* Processor goes to start_secondary(), sets online flag */
 778         ret = do_boot_cpu(sapicid, cpu);
 779         if (ret < 0)
 780                 return ret;
 781
 782         if (cpu_data(cpu)->threads_per_core == 1 &&
 783             cpu_data(cpu)->cores_per_socket == 1) {
 784                 cpu_set(cpu, cpu_sibling_map[cpu]);
 785                 cpu_set(cpu, cpu_core_map[cpu]);
 786                 return 0;
 787         }
 788
 789         set_cpu_sibling_map(cpu);
 790
 791         return 0;
 792 }
 793
 794 /*
 795  * Assume that CPU's have been discovered by some platform-dependent interface.  For
 796  * SoftSDV/Lion, that would be ACPI.
 797  *
 798  * Setup of the IPI irq handler is done in irq.c:init_IRQ_SMP().
 799  */
 800 void __init
 801 init_smp_config(void)
 802 {
 803         struct fptr {
 804                 unsigned long fp;
 805                 unsigned long gp;
 806         } *ap_startup;
 807         long sal_ret;
 808
 809         /* Tell SAL where to drop the AP's.  */
 810         ap_startup = (struct fptr *) start_ap;
 811         sal_ret = ia64_sal_set_vectors(SAL_VECTOR_OS_BOOT_RENDEZ,
 812                                        ia64_tpa(ap_startup->fp), ia64_tpa(ap_startup->gp), 0, 0, 0, 0);
 813         if (sal_ret < 0)
 814                 printk(KERN_ERR "SMP: Can't set SAL AP Boot Rendezvous: %s\n",
 815                        ia64_sal_strerror(sal_ret));
 816 }
 817
 818 static inline int __devinit
 819 check_for_mtinfo_index(void)
 820 {
 821         int i;
 822
 823         for_each_cpu(i)
 824                 if (!mt_info[i].valid)
 825                         return i;
 826
 827         return -1;
 828 }
 829
 830 /*
 831  * Search the mt_info to find out if this socket's cid/tid information is
 832  * cached or not. If the socket exists, fill in the core_id and thread_id
 833  * in cpuinfo
 834  */
 835 static int __devinit
 836 check_for_new_socket(__u16 logical_address, struct cpuinfo_ia64 *c)
 837 {
 838         int i;
 839         __u32 sid = c->socket_id;
 840
 841         for_each_cpu(i) {
 842                 if (mt_info[i].valid && mt_info[i].proc_fixed_addr == logical_address
 843                     && mt_info[i].socket_id == sid) {
 844                         c->core_id = mt_info[i].core_id;
 845                         c->thread_id = mt_info[i].thread_id;
 846                         return 1; /* not a new socket */
 847                 }
 848         }
 849         return 0;
 850 }
 851
 852 /*
 853  * identify_siblings(cpu) gets called from identify_cpu. This populates the
 854  * information related to logical execution units in per_cpu_data structure.
 855  */
 856 void __devinit
 857 identify_siblings(struct cpuinfo_ia64 *c)
 858 {
 859         s64 status;
 860         u16 pltid;
 861         u64 proc_fixed_addr;
 862         int count, i;
 863         pal_logical_to_physical_t info;
 864
 865         if (smp_num_cpucores == 1 && smp_num_siblings == 1)
 866                 return;
 867
 868         if ((status = ia64_pal_logical_to_phys(0, &info)) != PAL_STATUS_SUCCESS) {
 869                 printk(KERN_ERR "ia64_pal_logical_to_phys failed with %ld\n",
 870                        status);
 871                 return;
 872         }
 873         if ((status = ia64_sal_physical_id_info(&pltid)) != PAL_STATUS_SUCCESS) {
 874                 printk(KERN_ERR "ia64_sal_pltid failed with %ld\n", status);
 875                 return;
 876         }
 877         if ((status = ia64_pal_fixed_addr(&proc_fixed_addr)) != PAL_STATUS_SUCCESS) {
 878                 printk(KERN_ERR "ia64_pal_fixed_addr failed with %ld\n", status);
 879                 return;
 880         }
 881
 882         c->socket_id =  (pltid << 8) | info.overview_ppid;
 883         c->cores_per_socket = info.overview_cpp;
 884         c->threads_per_core = info.overview_tpc;
 885         count = c->num_log = info.overview_num_log;
 886
 887         /* If the thread and core id information is already cached, then
 888          * we will simply update cpu_info and return. Otherwise, we will
 889          * do the PAL calls and cache core and thread id's of all the siblings.
 890          */
 891         if (check_for_new_socket(proc_fixed_addr, c))
 892                 return;
 893
 894         for (i = 0; i < count; i++) {
 895                 int index;
 896
 897                 if (i && (status = ia64_pal_logical_to_phys(i, &info))
 898                           != PAL_STATUS_SUCCESS) {
 899                         printk(KERN_ERR "ia64_pal_logical_to_phys failed"
 900                                         " with %ld\n", status);
 901                         return;
 902                 }
 903                 if (info.log2_la == proc_fixed_addr) {
 904                         c->core_id = info.log1_cid;
 905                         c->thread_id = info.log1_tid;
 906                 }
 907
 908                 index = check_for_mtinfo_index();
 909                 /* We will not do the mt_info caching optimization in this case.
 910                  */
 911                 if (index < 0)
 912                         continue;
 913
 914                 mt_info[index].valid = 1;
 915                 mt_info[index].socket_id = c->socket_id;
 916                 mt_info[index].core_id = info.log1_cid;
 917                 mt_info[index].thread_id = info.log1_tid;
 918                 mt_info[index].proc_fixed_addr = info.log2_la;
 919         }
 920 }