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
 146 /* which logical CPU number maps to which CPU (physical APIC ID) */
 147 volatile int ia64_cpu_to_sapicid[NR_CPUS];
 148 EXPORT_SYMBOL(ia64_cpu_to_sapicid);
 149
 150 static volatile cpumask_t cpu_callin_map;
 151
 152 struct smp_boot_data smp_boot_data __initdata;
 153
 154 unsigned long ap_wakeup_vector = -1; /* External Int use to wakeup APs */
 155
 156 char __initdata no_int_routing;
 157
 158 unsigned char smp_int_redirect; /* are INT and IPI redirectable by the chipset? */
 159
 160 #ifdef CONFIG_FORCE_CPEI_RETARGET
 161 #define CPEI_OVERRIDE_DEFAULT   (1)
 162 #else
 163 #define CPEI_OVERRIDE_DEFAULT   (0)
 164 #endif
 165
 166 unsigned int force_cpei_retarget = CPEI_OVERRIDE_DEFAULT;
 167
 168 static int __init
 169 cmdl_force_cpei(char *str)
 170 {
 171         int value=0;
 172
 173         get_option (&str, &value);
 174         force_cpei_retarget = value;
 175
 176         return 1;
 177 }
 178
 179 __setup("force_cpei=", cmdl_force_cpei);
 180
 181 static int __init
 182 nointroute (char *str)
 183 {
 184         no_int_routing = 1;
 185         printk ("no_int_routing on\n");
 186         return 1;
 187 }
 188
 189 __setup("nointroute", nointroute);
 190
 191 static void fix_b0_for_bsp(void)
 192 {
 193 #ifdef CONFIG_HOTPLUG_CPU
 194         int cpuid;
 195         static int fix_bsp_b0 = 1;
 196
 197         cpuid = smp_processor_id();
 198
 199         /*
 200          * Cache the b0 value on the first AP that comes up
 201          */
 202         if (!(fix_bsp_b0 && cpuid))
 203                 return;
 204
 205         sal_boot_rendez_state[0].br[0] = sal_boot_rendez_state[cpuid].br[0];
 206         printk ("Fixed BSP b0 value from CPU %d\n", cpuid);
 207
 208         fix_bsp_b0 = 0;
 209 #endif
 210 }
 211
 212 void
 213 sync_master (void *arg)
 214 {
 215         unsigned long flags, i;
 216
 217         go[MASTER] = 0;
 218
 219         local_irq_save(flags);
 220         {
 221                 for (i = 0; i < NUM_ROUNDS*NUM_ITERS; ++i) {
 222                         while (!go[MASTER])
 223                                 cpu_relax();
 224                         go[MASTER] = 0;
 225                         go[SLAVE] = ia64_get_itc();
 226                 }
 227         }
 228         local_irq_restore(flags);
 229 }
 230
 231 /*
 232  * Return the number of cycles by which our itc differs from the itc on the master
 233  * (time-keeper) CPU.  A positive number indicates our itc is ahead of the master,
 234  * negative that it is behind.
 235  */
 236 static inline long
 237 get_delta (long *rt, long *master)
 238 {
 239         unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0;
 240         unsigned long tcenter, t0, t1, tm;
 241         long i;
 242
 243         for (i = 0; i < NUM_ITERS; ++i) {
 244                 t0 = ia64_get_itc();
 245                 go[MASTER] = 1;
 246                 while (!(tm = go[SLAVE]))
 247                         cpu_relax();
 248                 go[SLAVE] = 0;
 249                 t1 = ia64_get_itc();
 250
 251                 if (t1 - t0 < best_t1 - best_t0)
 252                         best_t0 = t0, best_t1 = t1, best_tm = tm;
 253         }
 254
 255         *rt = best_t1 - best_t0;
 256         *master = best_tm - best_t0;
 257
 258         /* average best_t0 and best_t1 without overflow: */
 259         tcenter = (best_t0/2 + best_t1/2);
 260         if (best_t0 % 2 + best_t1 % 2 == 2)
 261                 ++tcenter;
 262         return tcenter - best_tm;
 263 }
 264
 265 /*
 266  * Synchronize ar.itc of the current (slave) CPU with the ar.itc of the MASTER CPU
 267  * (normally the time-keeper CPU).  We use a closed loop to eliminate the possibility of
 268  * unaccounted-for errors (such as getting a machine check in the middle of a calibration
 269  * step).  The basic idea is for the slave to ask the master what itc value it has and to
 270  * read its own itc before and after the master responds.  Each iteration gives us three
 271  * timestamps:
 272  *
 273  *      slave           master
 274  *
 275  *      t0 ---\
 276  *             ---\
 277  *                 --->
 278  *                      tm
 279  *                 /---
 280  *             /---
 281  *      t1 <---
 282  *
 283  *
 284  * The goal is to adjust the slave's ar.itc such that tm falls exactly half-way between t0
 285  * and t1.  If we achieve this, the clocks are synchronized provided the interconnect
 286  * between the slave and the master is symmetric.  Even if the interconnect were
 287  * asymmetric, we would still know that the synchronization error is smaller than the
 288  * roundtrip latency (t0 - t1).
 289  *
 290  * When the interconnect is quiet and symmetric, this lets us synchronize the itc to
 291  * within one or two cycles.  However, we can only *guarantee* that the synchronization is
 292  * accurate to within a round-trip time, which is typically in the range of several
 293  * hundred cycles (e.g., ~500 cycles).  In practice, this means that the itc's are usually
 294  * almost perfectly synchronized, but we shouldn't assume that the accuracy is much better
 295  * than half a micro second or so.
 296  */
 297 void
 298 ia64_sync_itc (unsigned int master)
 299 {
 300         long i, delta, adj, adjust_latency = 0, done = 0;
 301         unsigned long flags, rt, master_time_stamp, bound;
 302 #if DEBUG_ITC_SYNC
 303         struct {
 304                 long rt;        /* roundtrip time */
 305                 long master;    /* master's timestamp */
 306                 long diff;      /* difference between midpoint and master's timestamp */
 307                 long lat;       /* estimate of itc adjustment latency */
 308         } t[NUM_ROUNDS];
 309 #endif
 310
 311         /*
 312          * Make sure local timer ticks are disabled while we sync.  If
 313          * they were enabled, we'd have to worry about nasty issues
 314          * like setting the ITC ahead of (or a long time before) the
 315          * next scheduled tick.
 316          */
 317         BUG_ON((ia64_get_itv() & (1 << 16)) == 0);
 318
 319         go[MASTER] = 1;
 320
 321         if (smp_call_function_single(master, sync_master, NULL, 1, 0) < 0) {
 322                 printk(KERN_ERR "sync_itc: failed to get attention of CPU %u!\n", master);
 323                 return;
 324         }
 325
 326         while (go[MASTER])
 327                 cpu_relax();    /* wait for master to be ready */
 328
 329         spin_lock_irqsave(&itc_sync_lock, flags);
 330         {
 331                 for (i = 0; i < NUM_ROUNDS; ++i) {
 332                         delta = get_delta(&rt, &master_time_stamp);
 333                         if (delta == 0) {
 334                                 done = 1;       /* let's lock on to this... */
 335                                 bound = rt;
 336                         }
 337
 338                         if (!done) {
 339                                 if (i > 0) {
 340                                         adjust_latency += -delta;
 341                                         adj = -delta + adjust_latency/4;
 342                                 } else
 343                                         adj = -delta;
 344
 345                                 ia64_set_itc(ia64_get_itc() + adj);
 346                         }
 347 #if DEBUG_ITC_SYNC
 348                         t[i].rt = rt;
 349                         t[i].master = master_time_stamp;
 350                         t[i].diff = delta;
 351                         t[i].lat = adjust_latency/4;
 352 #endif
 353                 }
 354         }
 355         spin_unlock_irqrestore(&itc_sync_lock, flags);
 356
 357 #if DEBUG_ITC_SYNC
 358         for (i = 0; i < NUM_ROUNDS; ++i)
 359                 printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n",
 360                        t[i].rt, t[i].master, t[i].diff, t[i].lat);
 361 #endif
 362
 363         printk(KERN_INFO "CPU %d: synchronized ITC with CPU %u (last diff %ld cycles, "
 364                "maxerr %lu cycles)\n", smp_processor_id(), master, delta, rt);
 365 }
 366
 367 /*
 368  * Ideally sets up per-cpu profiling hooks.  Doesn't do much now...
 369  */
 370 static inline void __devinit
 371 smp_setup_percpu_timer (void)
 372 {
 373 }
 374
 375 static void __cpuinit
 376 smp_callin (void)
 377 {
 378         int cpuid, phys_id, itc_master;
 379         struct cpuinfo_ia64 *last_cpuinfo, *this_cpuinfo;
 380         extern void ia64_init_itm(void);
 381         extern volatile int time_keeper_id;
 382
 383 #ifdef CONFIG_PERFMON
 384         extern void pfm_init_percpu(void);
 385 #endif
 386
 387         cpuid = smp_processor_id();
 388         phys_id = hard_smp_processor_id();
 389         itc_master = time_keeper_id;
 390
 391         if (cpu_online(cpuid)) {
 392                 printk(KERN_ERR "huh, phys CPU#0x%x, CPU#0x%x already present??\n",
 393                        phys_id, cpuid);
 394                 BUG();
 395         }
 396
 397         fix_b0_for_bsp();
 398
 399         lock_ipi_calllock();
 400         spin_lock(&vector_lock);
 401         /* Setup the per cpu irq handling data structures */
 402         __setup_vector_irq(cpuid);
 403         cpu_set(cpuid, cpu_online_map);
 404         unlock_ipi_calllock();
 405         per_cpu(cpu_state, cpuid) = CPU_ONLINE;
 406         spin_unlock(&vector_lock);
 407
 408         smp_setup_percpu_timer();
 409
 410         ia64_mca_cmc_vector_setup();    /* Setup vector on AP */
 411
 412 #ifdef CONFIG_PERFMON
 413         pfm_init_percpu();
 414 #endif
 415
 416         local_irq_enable();
 417
 418         if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
 419                 /*
 420                  * Synchronize the ITC with the BP.  Need to do this after irqs are
 421                  * enabled because ia64_sync_itc() calls smp_call_function_single(), which
 422                  * calls spin_unlock_bh(), which calls spin_unlock_bh(), which calls
 423                  * local_bh_enable(), which bugs out if irqs are not enabled...
 424                  */
 425                 Dprintk("Going to syncup ITC with ITC Master.\n");
 426                 ia64_sync_itc(itc_master);
 427         }
 428
 429         /*
 430          * Get our bogomips.
 431          */
 432         ia64_init_itm();
 433
 434         /*
 435          * Delay calibration can be skipped if new processor is identical to the
 436          * previous processor.
 437          */
 438         last_cpuinfo = cpu_data(cpuid - 1);
 439         this_cpuinfo = local_cpu_data;
 440         if (last_cpuinfo->itc_freq != this_cpuinfo->itc_freq ||
 441             last_cpuinfo->proc_freq != this_cpuinfo->proc_freq ||
 442             last_cpuinfo->features != this_cpuinfo->features ||
 443             last_cpuinfo->revision != this_cpuinfo->revision ||
 444             last_cpuinfo->family != this_cpuinfo->family ||
 445             last_cpuinfo->archrev != this_cpuinfo->archrev ||
 446             last_cpuinfo->model != this_cpuinfo->model)
 447                 calibrate_delay();
 448         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 449
 450 #ifdef CONFIG_IA32_SUPPORT
 451         ia32_gdt_init();
 452 #endif
 453
 454         /*
 455          * Allow the master to continue.
 456          */
 457         cpu_set(cpuid, cpu_callin_map);
 458         Dprintk("Stack on CPU %d at about %p\n",cpuid, &cpuid);
 459 }
 460
 461
 462 /*
 463  * Activate a secondary processor.  head.S calls this.
 464  */
 465 int __cpuinit
 466 start_secondary (void *unused)
 467 {
 468         /* Early console may use I/O ports */
 469         ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
 470         Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id());
 471         efi_map_pal_code();
 472         cpu_init();
 473         preempt_disable();
 474         smp_callin();
 475
 476         cpu_idle();
 477         return 0;
 478 }
 479
 480 struct pt_regs * __devinit idle_regs(struct pt_regs *regs)
 481 {
 482         return NULL;
 483 }
 484
 485 struct create_idle {
 486         struct work_struct work;
 487         struct task_struct *idle;
 488         struct completion done;
 489         int cpu;
 490 };
 491
 492 void __cpuinit
 493 do_fork_idle(struct work_struct *work)
 494 {
 495         struct create_idle *c_idle =
 496                 container_of(work, struct create_idle, work);
 497
 498         c_idle->idle = fork_idle(c_idle->cpu);
 499         complete(&c_idle->done);
 500 }
 501
 502 static int __cpuinit
 503 do_boot_cpu (int sapicid, int cpu)
 504 {
 505         int timeout;
 506         struct create_idle c_idle = {
 507                 .work = __WORK_INITIALIZER(c_idle.work, do_fork_idle),
 508                 .cpu    = cpu,
 509                 .done   = COMPLETION_INITIALIZER(c_idle.done),
 510         };
 511
 512         c_idle.idle = get_idle_for_cpu(cpu);
 513         if (c_idle.idle) {
 514                 init_idle(c_idle.idle, cpu);
 515                 goto do_rest;
 516         }
 517
 518         /*
 519          * We can't use kernel_thread since we must avoid to reschedule the child.
 520          */
 521         if (!keventd_up() || current_is_keventd())
 522                 c_idle.work.func(&c_idle.work);
 523         else {
 524                 schedule_work(&c_idle.work);
 525                 wait_for_completion(&c_idle.done);
 526         }
 527
 528         if (IS_ERR(c_idle.idle))
 529                 panic("failed fork for CPU %d", cpu);
 530
 531         set_idle_for_cpu(cpu, c_idle.idle);
 532
 533 do_rest:
 534         task_for_booting_cpu = c_idle.idle;
 535
 536         Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
 537
 538         set_brendez_area(cpu);
 539         platform_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0);
 540
 541         /*
 542          * Wait 10s total for the AP to start
 543          */
 544         Dprintk("Waiting on callin_map ...");
 545         for (timeout = 0; timeout < 100000; timeout++) {
 546                 if (cpu_isset(cpu, cpu_callin_map))
 547                         break;  /* It has booted */
 548                 udelay(100);
 549         }
 550         Dprintk("\n");
 551
 552         if (!cpu_isset(cpu, cpu_callin_map)) {
 553                 printk(KERN_ERR "Processor 0x%x/0x%x is stuck.\n", cpu, sapicid);
 554                 ia64_cpu_to_sapicid[cpu] = -1;
 555                 cpu_clear(cpu, cpu_online_map);  /* was set in smp_callin() */
 556                 return -EINVAL;
 557         }
 558         return 0;
 559 }
 560
 561 static int __init
 562 decay (char *str)
 563 {
 564         int ticks;
 565         get_option (&str, &ticks);
 566         return 1;
 567 }
 568
 569 __setup("decay=", decay);
 570
 571 /*
 572  * Initialize the logical CPU number to SAPICID mapping
 573  */
 574 void __init
 575 smp_build_cpu_map (void)
 576 {
 577         int sapicid, cpu, i;
 578         int boot_cpu_id = hard_smp_processor_id();
 579
 580         for (cpu = 0; cpu < NR_CPUS; cpu++) {
 581                 ia64_cpu_to_sapicid[cpu] = -1;
 582         }
 583
 584         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 585         cpus_clear(cpu_present_map);
 586         cpu_set(0, cpu_present_map);
 587         cpu_set(0, cpu_possible_map);
 588         for (cpu = 1, i = 0; i < smp_boot_data.cpu_count; i++) {
 589                 sapicid = smp_boot_data.cpu_phys_id[i];
 590                 if (sapicid == boot_cpu_id)
 591                         continue;
 592                 cpu_set(cpu, cpu_present_map);
 593                 cpu_set(cpu, cpu_possible_map);
 594                 ia64_cpu_to_sapicid[cpu] = sapicid;
 595                 cpu++;
 596         }
 597 }
 598
 599 /*
 600  * Cycle through the APs sending Wakeup IPIs to boot each.
 601  */
 602 void __init
 603 smp_prepare_cpus (unsigned int max_cpus)
 604 {
 605         int boot_cpu_id = hard_smp_processor_id();
 606
 607         /*
 608          * Initialize the per-CPU profiling counter/multiplier
 609          */
 610
 611         smp_setup_percpu_timer();
 612
 613         /*
 614          * We have the boot CPU online for sure.
 615          */
 616         cpu_set(0, cpu_online_map);
 617         cpu_set(0, cpu_callin_map);
 618
 619         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 620         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 621
 622         printk(KERN_INFO "Boot processor id 0x%x/0x%x\n", 0, boot_cpu_id);
 623
 624         current_thread_info()->cpu = 0;
 625
 626         /*
 627          * If SMP should be disabled, then really disable it!
 628          */
 629         if (!max_cpus) {
 630                 printk(KERN_INFO "SMP mode deactivated.\n");
 631                 cpus_clear(cpu_online_map);
 632                 cpus_clear(cpu_present_map);
 633                 cpus_clear(cpu_possible_map);
 634                 cpu_set(0, cpu_online_map);
 635                 cpu_set(0, cpu_present_map);
 636                 cpu_set(0, cpu_possible_map);
 637                 return;
 638         }
 639 }
 640
 641 void __devinit smp_prepare_boot_cpu(void)
 642 {
 643         cpu_set(smp_processor_id(), cpu_online_map);
 644         cpu_set(smp_processor_id(), cpu_callin_map);
 645         per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
 646 }
 647
 648 #ifdef CONFIG_HOTPLUG_CPU
 649 static inline void
 650 clear_cpu_sibling_map(int cpu)
 651 {
 652         int i;
 653
 654         for_each_cpu_mask(i, per_cpu(cpu_sibling_map, cpu))
 655                 cpu_clear(cpu, per_cpu(cpu_sibling_map, i));
 656         for_each_cpu_mask(i, cpu_core_map[cpu])
 657                 cpu_clear(cpu, cpu_core_map[i]);
 658
 659         per_cpu(cpu_sibling_map, cpu) = cpu_core_map[cpu] = CPU_MASK_NONE;
 660 }
 661
 662 static void
 663 remove_siblinginfo(int cpu)
 664 {
 665         int last = 0;
 666
 667         if (cpu_data(cpu)->threads_per_core == 1 &&
 668             cpu_data(cpu)->cores_per_socket == 1) {
 669                 cpu_clear(cpu, cpu_core_map[cpu]);
 670                 cpu_clear(cpu, per_cpu(cpu_sibling_map, cpu));
 671                 return;
 672         }
 673
 674         last = (cpus_weight(cpu_core_map[cpu]) == 1 ? 1 : 0);
 675
 676         /* remove it from all sibling map's */
 677         clear_cpu_sibling_map(cpu);
 678 }
 679
 680 extern void fixup_irqs(void);
 681
 682 int migrate_platform_irqs(unsigned int cpu)
 683 {
 684         int new_cpei_cpu;
 685         irq_desc_t *desc = NULL;
 686         cpumask_t       mask;
 687         int             retval = 0;
 688
 689         /*
 690          * dont permit CPEI target to removed.
 691          */
 692         if (cpe_vector > 0 && is_cpu_cpei_target(cpu)) {
 693                 printk ("CPU (%d) is CPEI Target\n", cpu);
 694                 if (can_cpei_retarget()) {
 695                         /*
 696                          * Now re-target the CPEI to a different processor
 697                          */
 698                         new_cpei_cpu = any_online_cpu(cpu_online_map);
 699                         mask = cpumask_of_cpu(new_cpei_cpu);
 700                         set_cpei_target_cpu(new_cpei_cpu);
 701                         desc = irq_desc + ia64_cpe_irq;
 702                         /*
 703                          * Switch for now, immediately, we need to do fake intr
 704                          * as other interrupts, but need to study CPEI behaviour with
 705                          * polling before making changes.
 706                          */
 707                         if (desc) {
 708                                 desc->chip->disable(ia64_cpe_irq);
 709                                 desc->chip->set_affinity(ia64_cpe_irq, mask);
 710                                 desc->chip->enable(ia64_cpe_irq);
 711                                 printk ("Re-targetting CPEI to cpu %d\n", new_cpei_cpu);
 712                         }
 713                 }
 714                 if (!desc) {
 715                         printk ("Unable to retarget CPEI, offline cpu [%d] failed\n", cpu);
 716                         retval = -EBUSY;
 717                 }
 718         }
 719         return retval;
 720 }
 721
 722 /* must be called with cpucontrol mutex held */
 723 int __cpu_disable(void)
 724 {
 725         int cpu = smp_processor_id();
 726
 727         /*
 728          * dont permit boot processor for now
 729          */
 730         if (cpu == 0 && !bsp_remove_ok) {
 731                 printk ("Your platform does not support removal of BSP\n");
 732                 return (-EBUSY);
 733         }
 734
 735         if (ia64_platform_is("sn2")) {
 736                 if (!sn_cpu_disable_allowed(cpu))
 737                         return -EBUSY;
 738         }
 739
 740         cpu_clear(cpu, cpu_online_map);
 741
 742         if (migrate_platform_irqs(cpu)) {
 743                 cpu_set(cpu, cpu_online_map);
 744                 return (-EBUSY);
 745         }
 746
 747         remove_siblinginfo(cpu);
 748         cpu_clear(cpu, cpu_online_map);
 749         fixup_irqs();
 750         local_flush_tlb_all();
 751         cpu_clear(cpu, cpu_callin_map);
 752         return 0;
 753 }
 754
 755 void __cpu_die(unsigned int cpu)
 756 {
 757         unsigned int i;
 758
 759         for (i = 0; i < 100; i++) {
 760                 /* They ack this in play_dead by setting CPU_DEAD */
 761                 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
 762                 {
 763                         printk ("CPU %d is now offline\n", cpu);
 764                         return;
 765                 }
 766                 msleep(100);
 767         }
 768         printk(KERN_ERR "CPU %u didn't die...\n", cpu);
 769 }
 770 #else /* !CONFIG_HOTPLUG_CPU */
 771 int __cpu_disable(void)
 772 {
 773         return -ENOSYS;
 774 }
 775
 776 void __cpu_die(unsigned int cpu)
 777 {
 778         /* We said "no" in __cpu_disable */
 779         BUG();
 780 }
 781 #endif /* CONFIG_HOTPLUG_CPU */
 782
 783 void
 784 smp_cpus_done (unsigned int dummy)
 785 {
 786         int cpu;
 787         unsigned long bogosum = 0;
 788
 789         /*
 790          * Allow the user to impress friends.
 791          */
 792
 793         for_each_online_cpu(cpu) {
 794                 bogosum += cpu_data(cpu)->loops_per_jiffy;
 795         }
 796
 797         printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
 798                (int)num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100);
 799 }
 800
 801 static inline void __devinit
 802 set_cpu_sibling_map(int cpu)
 803 {
 804         int i;
 805
 806         for_each_online_cpu(i) {
 807                 if ((cpu_data(cpu)->socket_id == cpu_data(i)->socket_id)) {
 808                         cpu_set(i, cpu_core_map[cpu]);
 809                         cpu_set(cpu, cpu_core_map[i]);
 810                         if (cpu_data(cpu)->core_id == cpu_data(i)->core_id) {
 811                                 cpu_set(i, per_cpu(cpu_sibling_map, cpu));
 812                                 cpu_set(cpu, per_cpu(cpu_sibling_map, i));
 813                         }
 814                 }
 815         }
 816 }
 817
 818 int __cpuinit
 819 __cpu_up (unsigned int cpu)
 820 {
 821         int ret;
 822         int sapicid;
 823
 824         sapicid = ia64_cpu_to_sapicid[cpu];
 825         if (sapicid == -1)
 826                 return -EINVAL;
 827
 828         /*
 829          * Already booted cpu? not valid anymore since we dont
 830          * do idle loop tightspin anymore.
 831          */
 832         if (cpu_isset(cpu, cpu_callin_map))
 833                 return -EINVAL;
 834
 835         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 836         /* Processor goes to start_secondary(), sets online flag */
 837         ret = do_boot_cpu(sapicid, cpu);
 838         if (ret < 0)
 839                 return ret;
 840
 841         if (cpu_data(cpu)->threads_per_core == 1 &&
 842             cpu_data(cpu)->cores_per_socket == 1) {
 843                 cpu_set(cpu, per_cpu(cpu_sibling_map, cpu));
 844                 cpu_set(cpu, cpu_core_map[cpu]);
 845                 return 0;
 846         }
 847
 848         set_cpu_sibling_map(cpu);
 849
 850         return 0;
 851 }
 852
 853 /*
 854  * Assume that CPUs have been discovered by some platform-dependent interface.  For
 855  * SoftSDV/Lion, that would be ACPI.
 856  *
 857  * Setup of the IPI irq handler is done in irq.c:init_IRQ_SMP().
 858  */
 859 void __init
 860 init_smp_config(void)
 861 {
 862         struct fptr {
 863                 unsigned long fp;
 864                 unsigned long gp;
 865         } *ap_startup;
 866         long sal_ret;
 867
 868         /* Tell SAL where to drop the APs.  */
 869         ap_startup = (struct fptr *) start_ap;
 870         sal_ret = ia64_sal_set_vectors(SAL_VECTOR_OS_BOOT_RENDEZ,
 871                                        ia64_tpa(ap_startup->fp), ia64_tpa(ap_startup->gp), 0, 0, 0, 0);
 872         if (sal_ret < 0)
 873                 printk(KERN_ERR "SMP: Can't set SAL AP Boot Rendezvous: %s\n",
 874                        ia64_sal_strerror(sal_ret));
 875 }
 876
 877 /*
 878  * identify_siblings(cpu) gets called from identify_cpu. This populates the
 879  * information related to logical execution units in per_cpu_data structure.
 880  */
 881 void __devinit
 882 identify_siblings(struct cpuinfo_ia64 *c)
 883 {
 884         s64 status;
 885         u16 pltid;
 886         pal_logical_to_physical_t info;
 887
 888         if ((status = ia64_pal_logical_to_phys(-1, &info)) != PAL_STATUS_SUCCESS) {
 889                 if (status != PAL_STATUS_UNIMPLEMENTED) {
 890                         printk(KERN_ERR
 891                                 "ia64_pal_logical_to_phys failed with %ld\n",
 892                                 status);
 893                         return;
 894                 }
 895
 896                 info.overview_ppid = 0;
 897                 info.overview_cpp  = 1;
 898                 info.overview_tpc  = 1;
 899         }
 900         if ((status = ia64_sal_physical_id_info(&pltid)) != PAL_STATUS_SUCCESS) {
 901                 printk(KERN_ERR "ia64_sal_pltid failed with %ld\n", status);
 902                 return;
 903         }
 904
 905         c->socket_id =  (pltid << 8) | info.overview_ppid;
 906
 907         if (info.overview_cpp == 1 && info.overview_tpc == 1)
 908                 return;
 909
 910         c->cores_per_socket = info.overview_cpp;
 911         c->threads_per_core = info.overview_tpc;
 912         c->num_log = info.overview_num_log;
 913
 914         c->core_id = info.log1_cid;
 915         c->thread_id = info.log1_tid;
 916 }
 917
 918 /*
 919  * returns non zero, if multi-threading is enabled
 920  * on at least one physical package. Due to hotplug cpu
 921  * and (maxcpus=), all threads may not necessarily be enabled
 922  * even though the processor supports multi-threading.
 923  */
 924 int is_multithreading_enabled(void)
 925 {
 926         int i, j;
 927
 928         for_each_present_cpu(i) {
 929                 for_each_present_cpu(j) {
 930                         if (j == i)
 931                                 continue;
 932                         if ((cpu_data(j)->socket_id == cpu_data(i)->socket_id)) {
 933                                 if (cpu_data(j)->core_id == cpu_data(i)->core_id)
 934                                         return 1;
 935                         }
 936                 }
 937         }
 938         return 0;
 939 }
 940 EXPORT_SYMBOL_GPL(is_multithreading_enabled);