git.oblomov.eu Git - linux-2.6/blob - 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/ia32.h>
  48 #include <asm/io.h>
  49 #include <asm/irq.h>
  50 #include <asm/machvec.h>
  51 #include <asm/mca.h>
  52 #include <asm/page.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 __devinit calibrate_delay (void);
 124 extern void start_ap (void);
 125 extern unsigned long ia64_iobase;
 126
 127 struct task_struct *task_for_booting_cpu;
 128
 129 /*
 130  * State for each CPU
 131  */
 132 DEFINE_PER_CPU(int, cpu_state);
 133
 134 /* Bitmasks of currently online, and possible CPUs */
 135 cpumask_t cpu_online_map;
 136 EXPORT_SYMBOL(cpu_online_map);
 137 cpumask_t cpu_possible_map = CPU_MASK_NONE;
 138 EXPORT_SYMBOL(cpu_possible_map);
 139
 140 cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
 141 DEFINE_PER_CPU_SHARED_ALIGNED(cpumask_t, cpu_sibling_map);
 142 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
 143
 144 int smp_num_siblings = 1;
 145 int smp_num_cpucores = 1;
 146
 147 /* which logical CPU number maps to which CPU (physical APIC ID) */
 148 volatile int ia64_cpu_to_sapicid[NR_CPUS];
 149 EXPORT_SYMBOL(ia64_cpu_to_sapicid);
 150
 151 static volatile cpumask_t cpu_callin_map;
 152
 153 struct smp_boot_data smp_boot_data __initdata;
 154
 155 unsigned long ap_wakeup_vector = -1; /* External Int use to wakeup APs */
 156
 157 char __initdata no_int_routing;
 158
 159 unsigned char smp_int_redirect; /* are INT and IPI redirectable by the chipset? */
 160
 161 #ifdef CONFIG_FORCE_CPEI_RETARGET
 162 #define CPEI_OVERRIDE_DEFAULT   (1)
 163 #else
 164 #define CPEI_OVERRIDE_DEFAULT   (0)
 165 #endif
 166
 167 unsigned int force_cpei_retarget = CPEI_OVERRIDE_DEFAULT;
 168
 169 static int __init
 170 cmdl_force_cpei(char *str)
 171 {
 172         int value=0;
 173
 174         get_option (&str, &value);
 175         force_cpei_retarget = value;
 176
 177         return 1;
 178 }
 179
 180 __setup("force_cpei=", cmdl_force_cpei);
 181
 182 static int __init
 183 nointroute (char *str)
 184 {
 185         no_int_routing = 1;
 186         printk ("no_int_routing on\n");
 187         return 1;
 188 }
 189
 190 __setup("nointroute", nointroute);
 191
 192 static void fix_b0_for_bsp(void)
 193 {
 194 #ifdef CONFIG_HOTPLUG_CPU
 195         int cpuid;
 196         static int fix_bsp_b0 = 1;
 197
 198         cpuid = smp_processor_id();
 199
 200         /*
 201          * Cache the b0 value on the first AP that comes up
 202          */
 203         if (!(fix_bsp_b0 && cpuid))
 204                 return;
 205
 206         sal_boot_rendez_state[0].br[0] = sal_boot_rendez_state[cpuid].br[0];
 207         printk ("Fixed BSP b0 value from CPU %d\n", cpuid);
 208
 209         fix_bsp_b0 = 0;
 210 #endif
 211 }
 212
 213 void
 214 sync_master (void *arg)
 215 {
 216         unsigned long flags, i;
 217
 218         go[MASTER] = 0;
 219
 220         local_irq_save(flags);
 221         {
 222                 for (i = 0; i < NUM_ROUNDS*NUM_ITERS; ++i) {
 223                         while (!go[MASTER])
 224                                 cpu_relax();
 225                         go[MASTER] = 0;
 226                         go[SLAVE] = ia64_get_itc();
 227                 }
 228         }
 229         local_irq_restore(flags);
 230 }
 231
 232 /*
 233  * Return the number of cycles by which our itc differs from the itc on the master
 234  * (time-keeper) CPU.  A positive number indicates our itc is ahead of the master,
 235  * negative that it is behind.
 236  */
 237 static inline long
 238 get_delta (long *rt, long *master)
 239 {
 240         unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0;
 241         unsigned long tcenter, t0, t1, tm;
 242         long i;
 243
 244         for (i = 0; i < NUM_ITERS; ++i) {
 245                 t0 = ia64_get_itc();
 246                 go[MASTER] = 1;
 247                 while (!(tm = go[SLAVE]))
 248                         cpu_relax();
 249                 go[SLAVE] = 0;
 250                 t1 = ia64_get_itc();
 251
 252                 if (t1 - t0 < best_t1 - best_t0)
 253                         best_t0 = t0, best_t1 = t1, best_tm = tm;
 254         }
 255
 256         *rt = best_t1 - best_t0;
 257         *master = best_tm - best_t0;
 258
 259         /* average best_t0 and best_t1 without overflow: */
 260         tcenter = (best_t0/2 + best_t1/2);
 261         if (best_t0 % 2 + best_t1 % 2 == 2)
 262                 ++tcenter;
 263         return tcenter - best_tm;
 264 }
 265
 266 /*
 267  * Synchronize ar.itc of the current (slave) CPU with the ar.itc of the MASTER CPU
 268  * (normally the time-keeper CPU).  We use a closed loop to eliminate the possibility of
 269  * unaccounted-for errors (such as getting a machine check in the middle of a calibration
 270  * step).  The basic idea is for the slave to ask the master what itc value it has and to
 271  * read its own itc before and after the master responds.  Each iteration gives us three
 272  * timestamps:
 273  *
 274  *      slave           master
 275  *
 276  *      t0 ---\
 277  *             ---\
 278  *                 --->
 279  *                      tm
 280  *                 /---
 281  *             /---
 282  *      t1 <---
 283  *
 284  *
 285  * The goal is to adjust the slave's ar.itc such that tm falls exactly half-way between t0
 286  * and t1.  If we achieve this, the clocks are synchronized provided the interconnect
 287  * between the slave and the master is symmetric.  Even if the interconnect were
 288  * asymmetric, we would still know that the synchronization error is smaller than the
 289  * roundtrip latency (t0 - t1).
 290  *
 291  * When the interconnect is quiet and symmetric, this lets us synchronize the itc to
 292  * within one or two cycles.  However, we can only *guarantee* that the synchronization is
 293  * accurate to within a round-trip time, which is typically in the range of several
 294  * hundred cycles (e.g., ~500 cycles).  In practice, this means that the itc's are usually
 295  * almost perfectly synchronized, but we shouldn't assume that the accuracy is much better
 296  * than half a micro second or so.
 297  */
 298 void
 299 ia64_sync_itc (unsigned int master)
 300 {
 301         long i, delta, adj, adjust_latency = 0, done = 0;
 302         unsigned long flags, rt, master_time_stamp, bound;
 303 #if DEBUG_ITC_SYNC
 304         struct {
 305                 long rt;        /* roundtrip time */
 306                 long master;    /* master's timestamp */
 307                 long diff;      /* difference between midpoint and master's timestamp */
 308                 long lat;       /* estimate of itc adjustment latency */
 309         } t[NUM_ROUNDS];
 310 #endif
 311
 312         /*
 313          * Make sure local timer ticks are disabled while we sync.  If
 314          * they were enabled, we'd have to worry about nasty issues
 315          * like setting the ITC ahead of (or a long time before) the
 316          * next scheduled tick.
 317          */
 318         BUG_ON((ia64_get_itv() & (1 << 16)) == 0);
 319
 320         go[MASTER] = 1;
 321
 322         if (smp_call_function_single(master, sync_master, NULL, 1, 0) < 0) {
 323                 printk(KERN_ERR "sync_itc: failed to get attention of CPU %u!\n", master);
 324                 return;
 325         }
 326
 327         while (go[MASTER])
 328                 cpu_relax();    /* wait for master to be ready */
 329
 330         spin_lock_irqsave(&itc_sync_lock, flags);
 331         {
 332                 for (i = 0; i < NUM_ROUNDS; ++i) {
 333                         delta = get_delta(&rt, &master_time_stamp);
 334                         if (delta == 0) {
 335                                 done = 1;       /* let's lock on to this... */
 336                                 bound = rt;
 337                         }
 338
 339                         if (!done) {
 340                                 if (i > 0) {
 341                                         adjust_latency += -delta;
 342                                         adj = -delta + adjust_latency/4;
 343                                 } else
 344                                         adj = -delta;
 345
 346                                 ia64_set_itc(ia64_get_itc() + adj);
 347                         }
 348 #if DEBUG_ITC_SYNC
 349                         t[i].rt = rt;
 350                         t[i].master = master_time_stamp;
 351                         t[i].diff = delta;
 352                         t[i].lat = adjust_latency/4;
 353 #endif
 354                 }
 355         }
 356         spin_unlock_irqrestore(&itc_sync_lock, flags);
 357
 358 #if DEBUG_ITC_SYNC
 359         for (i = 0; i < NUM_ROUNDS; ++i)
 360                 printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n",
 361                        t[i].rt, t[i].master, t[i].diff, t[i].lat);
 362 #endif
 363
 364         printk(KERN_INFO "CPU %d: synchronized ITC with CPU %u (last diff %ld cycles, "
 365                "maxerr %lu cycles)\n", smp_processor_id(), master, delta, rt);
 366 }
 367
 368 /*
 369  * Ideally sets up per-cpu profiling hooks.  Doesn't do much now...
 370  */
 371 static inline void __devinit
 372 smp_setup_percpu_timer (void)
 373 {
 374 }
 375
 376 static void __cpuinit
 377 smp_callin (void)
 378 {
 379         int cpuid, phys_id, itc_master;
 380         struct cpuinfo_ia64 *last_cpuinfo, *this_cpuinfo;
 381         extern void ia64_init_itm(void);
 382         extern volatile int time_keeper_id;
 383
 384 #ifdef CONFIG_PERFMON
 385         extern void pfm_init_percpu(void);
 386 #endif
 387
 388         cpuid = smp_processor_id();
 389         phys_id = hard_smp_processor_id();
 390         itc_master = time_keeper_id;
 391
 392         if (cpu_online(cpuid)) {
 393                 printk(KERN_ERR "huh, phys CPU#0x%x, CPU#0x%x already present??\n",
 394                        phys_id, cpuid);
 395                 BUG();
 396         }
 397
 398         fix_b0_for_bsp();
 399
 400         lock_ipi_calllock();
 401         spin_lock(&vector_lock);
 402         /* Setup the per cpu irq handling data structures */
 403         __setup_vector_irq(cpuid);
 404         cpu_set(cpuid, cpu_online_map);
 405         unlock_ipi_calllock();
 406         per_cpu(cpu_state, cpuid) = CPU_ONLINE;
 407         spin_unlock(&vector_lock);
 408
 409         smp_setup_percpu_timer();
 410
 411         ia64_mca_cmc_vector_setup();    /* Setup vector on AP */
 412
 413 #ifdef CONFIG_PERFMON
 414         pfm_init_percpu();
 415 #endif
 416
 417         local_irq_enable();
 418
 419         if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
 420                 /*
 421                  * Synchronize the ITC with the BP.  Need to do this after irqs are
 422                  * enabled because ia64_sync_itc() calls smp_call_function_single(), which
 423                  * calls spin_unlock_bh(), which calls spin_unlock_bh(), which calls
 424                  * local_bh_enable(), which bugs out if irqs are not enabled...
 425                  */
 426                 Dprintk("Going to syncup ITC with ITC Master.\n");
 427                 ia64_sync_itc(itc_master);
 428         }
 429
 430         /*
 431          * Get our bogomips.
 432          */
 433         ia64_init_itm();
 434
 435         /*
 436          * Delay calibration can be skipped if new processor is identical to the
 437          * previous processor.
 438          */
 439         last_cpuinfo = cpu_data(cpuid - 1);
 440         this_cpuinfo = local_cpu_data;
 441         if (last_cpuinfo->itc_freq != this_cpuinfo->itc_freq ||
 442             last_cpuinfo->proc_freq != this_cpuinfo->proc_freq ||
 443             last_cpuinfo->features != this_cpuinfo->features ||
 444             last_cpuinfo->revision != this_cpuinfo->revision ||
 445             last_cpuinfo->family != this_cpuinfo->family ||
 446             last_cpuinfo->archrev != this_cpuinfo->archrev ||
 447             last_cpuinfo->model != this_cpuinfo->model)
 448                 calibrate_delay();
 449         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 450
 451 #ifdef CONFIG_IA32_SUPPORT
 452         ia32_gdt_init();
 453 #endif
 454
 455         /*
 456          * Allow the master to continue.
 457          */
 458         cpu_set(cpuid, cpu_callin_map);
 459         Dprintk("Stack on CPU %d at about %p\n",cpuid, &cpuid);
 460 }
 461
 462
 463 /*
 464  * Activate a secondary processor.  head.S calls this.
 465  */
 466 int __cpuinit
 467 start_secondary (void *unused)
 468 {
 469         /* Early console may use I/O ports */
 470         ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
 471         Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id());
 472         efi_map_pal_code();
 473         cpu_init();
 474         preempt_disable();
 475         smp_callin();
 476
 477         cpu_idle();
 478         return 0;
 479 }
 480
 481 struct pt_regs * __devinit idle_regs(struct pt_regs *regs)
 482 {
 483         return NULL;
 484 }
 485
 486 struct create_idle {
 487         struct work_struct work;
 488         struct task_struct *idle;
 489         struct completion done;
 490         int cpu;
 491 };
 492
 493 void __cpuinit
 494 do_fork_idle(struct work_struct *work)
 495 {
 496         struct create_idle *c_idle =
 497                 container_of(work, struct create_idle, work);
 498
 499         c_idle->idle = fork_idle(c_idle->cpu);
 500         complete(&c_idle->done);
 501 }
 502
 503 static int __cpuinit
 504 do_boot_cpu (int sapicid, int cpu)
 505 {
 506         int timeout;
 507         struct create_idle c_idle = {
 508                 .work = __WORK_INITIALIZER(c_idle.work, do_fork_idle),
 509                 .cpu    = cpu,
 510                 .done   = COMPLETION_INITIALIZER(c_idle.done),
 511         };
 512
 513         c_idle.idle = get_idle_for_cpu(cpu);
 514         if (c_idle.idle) {
 515                 init_idle(c_idle.idle, cpu);
 516                 goto do_rest;
 517         }
 518
 519         /*
 520          * We can't use kernel_thread since we must avoid to reschedule the child.
 521          */
 522         if (!keventd_up() || current_is_keventd())
 523                 c_idle.work.func(&c_idle.work);
 524         else {
 525                 schedule_work(&c_idle.work);
 526                 wait_for_completion(&c_idle.done);
 527         }
 528
 529         if (IS_ERR(c_idle.idle))
 530                 panic("failed fork for CPU %d", cpu);
 531
 532         set_idle_for_cpu(cpu, c_idle.idle);
 533
 534 do_rest:
 535         task_for_booting_cpu = c_idle.idle;
 536
 537         Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
 538
 539         set_brendez_area(cpu);
 540         platform_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0);
 541
 542         /*
 543          * Wait 10s total for the AP to start
 544          */
 545         Dprintk("Waiting on callin_map ...");
 546         for (timeout = 0; timeout < 100000; timeout++) {
 547                 if (cpu_isset(cpu, cpu_callin_map))
 548                         break;  /* It has booted */
 549                 udelay(100);
 550         }
 551         Dprintk("\n");
 552
 553         if (!cpu_isset(cpu, cpu_callin_map)) {
 554                 printk(KERN_ERR "Processor 0x%x/0x%x is stuck.\n", cpu, sapicid);
 555                 ia64_cpu_to_sapicid[cpu] = -1;
 556                 cpu_clear(cpu, cpu_online_map);  /* was set in smp_callin() */
 557                 return -EINVAL;
 558         }
 559         return 0;
 560 }
 561
 562 static int __init
 563 decay (char *str)
 564 {
 565         int ticks;
 566         get_option (&str, &ticks);
 567         return 1;
 568 }
 569
 570 __setup("decay=", decay);
 571
 572 /*
 573  * Initialize the logical CPU number to SAPICID mapping
 574  */
 575 void __init
 576 smp_build_cpu_map (void)
 577 {
 578         int sapicid, cpu, i;
 579         int boot_cpu_id = hard_smp_processor_id();
 580
 581         for (cpu = 0; cpu < NR_CPUS; cpu++) {
 582                 ia64_cpu_to_sapicid[cpu] = -1;
 583         }
 584
 585         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 586         cpus_clear(cpu_present_map);
 587         cpu_set(0, cpu_present_map);
 588         cpu_set(0, cpu_possible_map);
 589         for (cpu = 1, i = 0; i < smp_boot_data.cpu_count; i++) {
 590                 sapicid = smp_boot_data.cpu_phys_id[i];
 591                 if (sapicid == boot_cpu_id)
 592                         continue;
 593                 cpu_set(cpu, cpu_present_map);
 594                 cpu_set(cpu, cpu_possible_map);
 595                 ia64_cpu_to_sapicid[cpu] = sapicid;
 596                 cpu++;
 597         }
 598 }
 599
 600 /*
 601  * Cycle through the APs sending Wakeup IPIs to boot each.
 602  */
 603 void __init
 604 smp_prepare_cpus (unsigned int max_cpus)
 605 {
 606         int boot_cpu_id = hard_smp_processor_id();
 607
 608         /*
 609          * Initialize the per-CPU profiling counter/multiplier
 610          */
 611
 612         smp_setup_percpu_timer();
 613
 614         /*
 615          * We have the boot CPU online for sure.
 616          */
 617         cpu_set(0, cpu_online_map);
 618         cpu_set(0, cpu_callin_map);
 619
 620         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 621         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 622
 623         printk(KERN_INFO "Boot processor id 0x%x/0x%x\n", 0, boot_cpu_id);
 624
 625         current_thread_info()->cpu = 0;
 626
 627         /*
 628          * If SMP should be disabled, then really disable it!
 629          */
 630         if (!max_cpus) {
 631                 printk(KERN_INFO "SMP mode deactivated.\n");
 632                 cpus_clear(cpu_online_map);
 633                 cpus_clear(cpu_present_map);
 634                 cpus_clear(cpu_possible_map);
 635                 cpu_set(0, cpu_online_map);
 636                 cpu_set(0, cpu_present_map);
 637                 cpu_set(0, cpu_possible_map);
 638                 return;
 639         }
 640 }
 641
 642 void __devinit smp_prepare_boot_cpu(void)
 643 {
 644         cpu_set(smp_processor_id(), cpu_online_map);
 645         cpu_set(smp_processor_id(), cpu_callin_map);
 646         per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
 647 }
 648
 649 #ifdef CONFIG_HOTPLUG_CPU
 650 static inline void
 651 clear_cpu_sibling_map(int cpu)
 652 {
 653         int i;
 654
 655         for_each_cpu_mask(i, per_cpu(cpu_sibling_map, cpu))
 656                 cpu_clear(cpu, per_cpu(cpu_sibling_map, i));
 657         for_each_cpu_mask(i, cpu_core_map[cpu])
 658                 cpu_clear(cpu, cpu_core_map[i]);
 659
 660         per_cpu(cpu_sibling_map, cpu) = cpu_core_map[cpu] = CPU_MASK_NONE;
 661 }
 662
 663 static void
 664 remove_siblinginfo(int cpu)
 665 {
 666         int last = 0;
 667
 668         if (cpu_data(cpu)->threads_per_core == 1 &&
 669             cpu_data(cpu)->cores_per_socket == 1) {
 670                 cpu_clear(cpu, cpu_core_map[cpu]);
 671                 cpu_clear(cpu, per_cpu(cpu_sibling_map, cpu));
 672                 return;
 673         }
 674
 675         last = (cpus_weight(cpu_core_map[cpu]) == 1 ? 1 : 0);
 676
 677         /* remove it from all sibling map's */
 678         clear_cpu_sibling_map(cpu);
 679 }
 680
 681 extern void fixup_irqs(void);
 682
 683 int migrate_platform_irqs(unsigned int cpu)
 684 {
 685         int new_cpei_cpu;
 686         irq_desc_t *desc = NULL;
 687         cpumask_t       mask;
 688         int             retval = 0;
 689
 690         /*
 691          * dont permit CPEI target to removed.
 692          */
 693         if (cpe_vector > 0 && is_cpu_cpei_target(cpu)) {
 694                 printk ("CPU (%d) is CPEI Target\n", cpu);
 695                 if (can_cpei_retarget()) {
 696                         /*
 697                          * Now re-target the CPEI to a different processor
 698                          */
 699                         new_cpei_cpu = any_online_cpu(cpu_online_map);
 700                         mask = cpumask_of_cpu(new_cpei_cpu);
 701                         set_cpei_target_cpu(new_cpei_cpu);
 702                         desc = irq_desc + ia64_cpe_irq;
 703                         /*
 704                          * Switch for now, immediately, we need to do fake intr
 705                          * as other interrupts, but need to study CPEI behaviour with
 706                          * polling before making changes.
 707                          */
 708                         if (desc) {
 709                                 desc->chip->disable(ia64_cpe_irq);
 710                                 desc->chip->set_affinity(ia64_cpe_irq, mask);
 711                                 desc->chip->enable(ia64_cpe_irq);
 712                                 printk ("Re-targetting CPEI to cpu %d\n", new_cpei_cpu);
 713                         }
 714                 }
 715                 if (!desc) {
 716                         printk ("Unable to retarget CPEI, offline cpu [%d] failed\n", cpu);
 717                         retval = -EBUSY;
 718                 }
 719         }
 720         return retval;
 721 }
 722
 723 /* must be called with cpucontrol mutex held */
 724 int __cpu_disable(void)
 725 {
 726         int cpu = smp_processor_id();
 727
 728         /*
 729          * dont permit boot processor for now
 730          */
 731         if (cpu == 0 && !bsp_remove_ok) {
 732                 printk ("Your platform does not support removal of BSP\n");
 733                 return (-EBUSY);
 734         }
 735
 736         if (ia64_platform_is("sn2")) {
 737                 if (!sn_cpu_disable_allowed(cpu))
 738                         return -EBUSY;
 739         }
 740
 741         cpu_clear(cpu, cpu_online_map);
 742
 743         if (migrate_platform_irqs(cpu)) {
 744                 cpu_set(cpu, cpu_online_map);
 745                 return (-EBUSY);
 746         }
 747
 748         remove_siblinginfo(cpu);
 749         cpu_clear(cpu, cpu_online_map);
 750         fixup_irqs();
 751         local_flush_tlb_all();
 752         cpu_clear(cpu, cpu_callin_map);
 753         return 0;
 754 }
 755
 756 void __cpu_die(unsigned int cpu)
 757 {
 758         unsigned int i;
 759
 760         for (i = 0; i < 100; i++) {
 761                 /* They ack this in play_dead by setting CPU_DEAD */
 762                 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
 763                 {
 764                         printk ("CPU %d is now offline\n", cpu);
 765                         return;
 766                 }
 767                 msleep(100);
 768         }
 769         printk(KERN_ERR "CPU %u didn't die...\n", cpu);
 770 }
 771 #else /* !CONFIG_HOTPLUG_CPU */
 772 int __cpu_disable(void)
 773 {
 774         return -ENOSYS;
 775 }
 776
 777 void __cpu_die(unsigned int cpu)
 778 {
 779         /* We said "no" in __cpu_disable */
 780         BUG();
 781 }
 782 #endif /* CONFIG_HOTPLUG_CPU */
 783
 784 void
 785 smp_cpus_done (unsigned int dummy)
 786 {
 787         int cpu;
 788         unsigned long bogosum = 0;
 789
 790         /*
 791          * Allow the user to impress friends.
 792          */
 793
 794         for_each_online_cpu(cpu) {
 795                 bogosum += cpu_data(cpu)->loops_per_jiffy;
 796         }
 797
 798         printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
 799                (int)num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100);
 800 }
 801
 802 static inline void __devinit
 803 set_cpu_sibling_map(int cpu)
 804 {
 805         int i;
 806
 807         for_each_online_cpu(i) {
 808                 if ((cpu_data(cpu)->socket_id == cpu_data(i)->socket_id)) {
 809                         cpu_set(i, cpu_core_map[cpu]);
 810                         cpu_set(cpu, cpu_core_map[i]);
 811                         if (cpu_data(cpu)->core_id == cpu_data(i)->core_id) {
 812                                 cpu_set(i, per_cpu(cpu_sibling_map, cpu));
 813                                 cpu_set(cpu, per_cpu(cpu_sibling_map, i));
 814                         }
 815                 }
 816         }
 817 }
 818
 819 int __cpuinit
 820 __cpu_up (unsigned int cpu)
 821 {
 822         int ret;
 823         int sapicid;
 824
 825         sapicid = ia64_cpu_to_sapicid[cpu];
 826         if (sapicid == -1)
 827                 return -EINVAL;
 828
 829         /*
 830          * Already booted cpu? not valid anymore since we dont
 831          * do idle loop tightspin anymore.
 832          */
 833         if (cpu_isset(cpu, cpu_callin_map))
 834                 return -EINVAL;
 835
 836         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 837         /* Processor goes to start_secondary(), sets online flag */
 838         ret = do_boot_cpu(sapicid, cpu);
 839         if (ret < 0)
 840                 return ret;
 841
 842         if (cpu_data(cpu)->threads_per_core == 1 &&
 843             cpu_data(cpu)->cores_per_socket == 1) {
 844                 cpu_set(cpu, per_cpu(cpu_sibling_map, cpu));
 845                 cpu_set(cpu, cpu_core_map[cpu]);
 846                 return 0;
 847         }
 848
 849         set_cpu_sibling_map(cpu);
 850
 851         return 0;
 852 }
 853
 854 /*
 855  * Assume that CPUs have been discovered by some platform-dependent interface.  For
 856  * SoftSDV/Lion, that would be ACPI.
 857  *
 858  * Setup of the IPI irq handler is done in irq.c:init_IRQ_SMP().
 859  */
 860 void __init
 861 init_smp_config(void)
 862 {
 863         struct fptr {
 864                 unsigned long fp;
 865                 unsigned long gp;
 866         } *ap_startup;
 867         long sal_ret;
 868
 869         /* Tell SAL where to drop the APs.  */
 870         ap_startup = (struct fptr *) start_ap;
 871         sal_ret = ia64_sal_set_vectors(SAL_VECTOR_OS_BOOT_RENDEZ,
 872                                        ia64_tpa(ap_startup->fp), ia64_tpa(ap_startup->gp), 0, 0, 0, 0);
 873         if (sal_ret < 0)
 874                 printk(KERN_ERR "SMP: Can't set SAL AP Boot Rendezvous: %s\n",
 875                        ia64_sal_strerror(sal_ret));
 876 }
 877
 878 /*
 879  * identify_siblings(cpu) gets called from identify_cpu. This populates the
 880  * information related to logical execution units in per_cpu_data structure.
 881  */
 882 void __devinit
 883 identify_siblings(struct cpuinfo_ia64 *c)
 884 {
 885         s64 status;
 886         u16 pltid;
 887         pal_logical_to_physical_t info;
 888
 889         if (smp_num_cpucores == 1 && smp_num_siblings == 1)
 890                 return;
 891
 892         if ((status = ia64_pal_logical_to_phys(-1, &info)) != PAL_STATUS_SUCCESS) {
 893                 printk(KERN_ERR "ia64_pal_logical_to_phys failed with %ld\n",
 894                        status);
 895                 return;
 896         }
 897         if ((status = ia64_sal_physical_id_info(&pltid)) != PAL_STATUS_SUCCESS) {
 898                 printk(KERN_ERR "ia64_sal_pltid failed with %ld\n", status);
 899                 return;
 900         }
 901
 902         c->socket_id =  (pltid << 8) | info.overview_ppid;
 903         c->cores_per_socket = info.overview_cpp;
 904         c->threads_per_core = info.overview_tpc;
 905         c->num_log = info.overview_num_log;
 906
 907         c->core_id = info.log1_cid;
 908         c->thread_id = info.log1_tid;
 909 }
 910
 911 /*
 912  * returns non zero, if multi-threading is enabled
 913  * on at least one physical package. Due to hotplug cpu
 914  * and (maxcpus=), all threads may not necessarily be enabled
 915  * even though the processor supports multi-threading.
 916  */
 917 int is_multithreading_enabled(void)
 918 {
 919         int i, j;
 920
 921         for_each_present_cpu(i) {
 922                 for_each_present_cpu(j) {
 923                         if (j == i)
 924                                 continue;
 925                         if ((cpu_data(j)->socket_id == cpu_data(i)->socket_id)) {
 926                                 if (cpu_data(j)->core_id == cpu_data(i)->core_id)
 927                                         return 1;
 928                         }
 929                 }
 930         }
 931         return 0;
 932 }
 933 EXPORT_SYMBOL_GPL(is_multithreading_enabled);