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