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