arch/ia64/kernel/smpboot.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * SMP boot-related support
   4  *
   5  * Copyright (C) 1998-2003, 2005 Hewlett-Packard Co
   6  *      David Mosberger-Tang <davidm@hpl.hp.com>
   7  * Copyright (C) 2001, 2004-2005 Intel Corp
   8  *      Rohit Seth <rohit.seth@intel.com>
   9  *      Suresh Siddha <suresh.b.siddha@intel.com>
  10  *      Gordon Jin <gordon.jin@intel.com>
  11  *      Ashok Raj  <ashok.raj@intel.com>
  12  *
  13  * 01/05/16 Rohit Seth <rohit.seth@intel.com>   Moved SMP booting functions from smp.c to here.
  14  * 01/04/27 David Mosberger <davidm@hpl.hp.com> Added ITC synching code.
  15  * 02/07/31 David Mosberger <davidm@hpl.hp.com> Switch over to hotplug-CPU boot-sequence.
  16  *                                              smp_boot_cpus()/smp_commence() is replaced by
  17  *                                              smp_prepare_cpus()/__cpu_up()/smp_cpus_done().
  18  * 04/06/21 Ashok Raj           <ashok.raj@intel.com> Added CPU Hotplug Support
  19  * 04/12/26 Jin Gordon <gordon.jin@intel.com>
  20  * 04/12/26 Rohit Seth <rohit.seth@intel.com>
  21  *                                              Add multi-threading and multi-core detection
  22  * 05/01/30 Suresh Siddha <suresh.b.siddha@intel.com>
  23  *                                              Setup cpu_sibling_map and cpu_core_map
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/acpi.h>
  28 #include <linux/memblock.h>
  29 #include <linux/cpu.h>
  30 #include <linux/delay.h>
  31 #include <linux/init.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/irq.h>
  34 #include <linux/kernel.h>
  35 #include <linux/kernel_stat.h>
  36 #include <linux/mm.h>
  37 #include <linux/notifier.h>
  38 #include <linux/smp.h>
  39 #include <linux/spinlock.h>
  40 #include <linux/efi.h>
  41 #include <linux/percpu.h>
  42 #include <linux/bitops.h>
  43
  44 #include <linux/atomic.h>
  45 #include <asm/cache.h>
  46 #include <asm/current.h>
  47 #include <asm/delay.h>
  48 #include <asm/efi.h>
  49 #include <asm/io.h>
  50 #include <asm/irq.h>
  51 #include <asm/mca.h>
  52 #include <asm/page.h>
  53 #include <asm/processor.h>
  54 #include <asm/ptrace.h>
  55 #include <asm/sal.h>
  56 #include <asm/tlbflush.h>
  57 #include <asm/unistd.h>
  58
  59 #define SMP_DEBUG 0
  60
  61 #if SMP_DEBUG
  62 #define Dprintk(x...)  printk(x)
  63 #else
  64 #define Dprintk(x...)
  65 #endif
  66
  67 #ifdef CONFIG_HOTPLUG_CPU
  68 #ifdef CONFIG_PERMIT_BSP_REMOVE
  69 #define bsp_remove_ok   1
  70 #else
  71 #define bsp_remove_ok   0
  72 #endif
  73
  74 /*
  75  * Global array allocated for NR_CPUS at boot time
  76  */
  77 struct sal_to_os_boot sal_boot_rendez_state[NR_CPUS];
  78
  79 /*
  80  * start_ap in head.S uses this to store current booting cpu
  81  * info.
  82  */
  83 struct sal_to_os_boot *sal_state_for_booting_cpu = &sal_boot_rendez_state[0];
  84
  85 #define set_brendez_area(x) (sal_state_for_booting_cpu = &sal_boot_rendez_state[(x)]);
  86
  87 #else
  88 #define set_brendez_area(x)
  89 #endif
  90
  91
  92 /*
  93  * ITC synchronization related stuff:
  94  */
  95 #define MASTER  (0)
  96 #define SLAVE   (SMP_CACHE_BYTES/8)
  97
  98 #define NUM_ROUNDS      64      /* magic value */
  99 #define NUM_ITERS       5       /* likewise */
 100
 101 static DEFINE_SPINLOCK(itc_sync_lock);
 102 static volatile unsigned long go[SLAVE + 1];
 103
 104 #define DEBUG_ITC_SYNC  0
 105
 106 extern void start_ap (void);
 107 extern unsigned long ia64_iobase;
 108
 109 struct task_struct *task_for_booting_cpu;
 110
 111 /*
 112  * State for each CPU
 113  */
 114 DEFINE_PER_CPU(int, cpu_state);
 115
 116 cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
 117 EXPORT_SYMBOL(cpu_core_map);
 118 DEFINE_PER_CPU_SHARED_ALIGNED(cpumask_t, cpu_sibling_map);
 119 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
 120
 121 int smp_num_siblings = 1;
 122
 123 /* which logical CPU number maps to which CPU (physical APIC ID) */
 124 volatile int ia64_cpu_to_sapicid[NR_CPUS];
 125 EXPORT_SYMBOL(ia64_cpu_to_sapicid);
 126
 127 static cpumask_t cpu_callin_map;
 128
 129 struct smp_boot_data smp_boot_data __initdata;
 130
 131 unsigned long ap_wakeup_vector = -1; /* External Int use to wakeup APs */
 132
 133 char __initdata no_int_routing;
 134
 135 unsigned char smp_int_redirect; /* are INT and IPI redirectable by the chipset? */
 136
 137 #ifdef CONFIG_FORCE_CPEI_RETARGET
 138 #define CPEI_OVERRIDE_DEFAULT   (1)
 139 #else
 140 #define CPEI_OVERRIDE_DEFAULT   (0)
 141 #endif
 142
 143 unsigned int force_cpei_retarget = CPEI_OVERRIDE_DEFAULT;
 144
 145 static int __init
 146 cmdl_force_cpei(char *str)
 147 {
 148         int value=0;
 149
 150         get_option (&str, &value);
 151         force_cpei_retarget = value;
 152
 153         return 1;
 154 }
 155
 156 __setup("force_cpei=", cmdl_force_cpei);
 157
 158 static int __init
 159 nointroute (char *str)
 160 {
 161         no_int_routing = 1;
 162         printk ("no_int_routing on\n");
 163         return 1;
 164 }
 165
 166 __setup("nointroute", nointroute);
 167
 168 static void fix_b0_for_bsp(void)
 169 {
 170 #ifdef CONFIG_HOTPLUG_CPU
 171         int cpuid;
 172         static int fix_bsp_b0 = 1;
 173
 174         cpuid = smp_processor_id();
 175
 176         /*
 177          * Cache the b0 value on the first AP that comes up
 178          */
 179         if (!(fix_bsp_b0 && cpuid))
 180                 return;
 181
 182         sal_boot_rendez_state[0].br[0] = sal_boot_rendez_state[cpuid].br[0];
 183         printk ("Fixed BSP b0 value from CPU %d\n", cpuid);
 184
 185         fix_bsp_b0 = 0;
 186 #endif
 187 }
 188
 189 void
 190 sync_master (void *arg)
 191 {
 192         unsigned long flags, i;
 193
 194         go[MASTER] = 0;
 195
 196         local_irq_save(flags);
 197         {
 198                 for (i = 0; i < NUM_ROUNDS*NUM_ITERS; ++i) {
 199                         while (!go[MASTER])
 200                                 cpu_relax();
 201                         go[MASTER] = 0;
 202                         go[SLAVE] = ia64_get_itc();
 203                 }
 204         }
 205         local_irq_restore(flags);
 206 }
 207
 208 /*
 209  * Return the number of cycles by which our itc differs from the itc on the master
 210  * (time-keeper) CPU.  A positive number indicates our itc is ahead of the master,
 211  * negative that it is behind.
 212  */
 213 static inline long
 214 get_delta (long *rt, long *master)
 215 {
 216         unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0;
 217         unsigned long tcenter, t0, t1, tm;
 218         long i;
 219
 220         for (i = 0; i < NUM_ITERS; ++i) {
 221                 t0 = ia64_get_itc();
 222                 go[MASTER] = 1;
 223                 while (!(tm = go[SLAVE]))
 224                         cpu_relax();
 225                 go[SLAVE] = 0;
 226                 t1 = ia64_get_itc();
 227
 228                 if (t1 - t0 < best_t1 - best_t0)
 229                         best_t0 = t0, best_t1 = t1, best_tm = tm;
 230         }
 231
 232         *rt = best_t1 - best_t0;
 233         *master = best_tm - best_t0;
 234
 235         /* average best_t0 and best_t1 without overflow: */
 236         tcenter = (best_t0/2 + best_t1/2);
 237         if (best_t0 % 2 + best_t1 % 2 == 2)
 238                 ++tcenter;
 239         return tcenter - best_tm;
 240 }
 241
 242 /*
 243  * Synchronize ar.itc of the current (slave) CPU with the ar.itc of the MASTER CPU
 244  * (normally the time-keeper CPU).  We use a closed loop to eliminate the possibility of
 245  * unaccounted-for errors (such as getting a machine check in the middle of a calibration
 246  * step).  The basic idea is for the slave to ask the master what itc value it has and to
 247  * read its own itc before and after the master responds.  Each iteration gives us three
 248  * timestamps:
 249  *
 250  *      slave           master
 251  *
 252  *      t0 ---\
 253  *             ---\
 254  *                 --->
 255  *                      tm
 256  *                 /---
 257  *             /---
 258  *      t1 <---
 259  *
 260  *
 261  * The goal is to adjust the slave's ar.itc such that tm falls exactly half-way between t0
 262  * and t1.  If we achieve this, the clocks are synchronized provided the interconnect
 263  * between the slave and the master is symmetric.  Even if the interconnect were
 264  * asymmetric, we would still know that the synchronization error is smaller than the
 265  * roundtrip latency (t0 - t1).
 266  *
 267  * When the interconnect is quiet and symmetric, this lets us synchronize the itc to
 268  * within one or two cycles.  However, we can only *guarantee* that the synchronization is
 269  * accurate to within a round-trip time, which is typically in the range of several
 270  * hundred cycles (e.g., ~500 cycles).  In practice, this means that the itc's are usually
 271  * almost perfectly synchronized, but we shouldn't assume that the accuracy is much better
 272  * than half a micro second or so.
 273  */
 274 void
 275 ia64_sync_itc (unsigned int master)
 276 {
 277         long i, delta, adj, adjust_latency = 0, done = 0;
 278         unsigned long flags, rt, master_time_stamp, bound;
 279 #if DEBUG_ITC_SYNC
 280         struct {
 281                 long rt;        /* roundtrip time */
 282                 long master;    /* master's timestamp */
 283                 long diff;      /* difference between midpoint and master's timestamp */
 284                 long lat;       /* estimate of itc adjustment latency */
 285         } t[NUM_ROUNDS];
 286 #endif
 287
 288         /*
 289          * Make sure local timer ticks are disabled while we sync.  If
 290          * they were enabled, we'd have to worry about nasty issues
 291          * like setting the ITC ahead of (or a long time before) the
 292          * next scheduled tick.
 293          */
 294         BUG_ON((ia64_get_itv() & (1 << 16)) == 0);
 295
 296         go[MASTER] = 1;
 297
 298         if (smp_call_function_single(master, sync_master, NULL, 0) < 0) {
 299                 printk(KERN_ERR "sync_itc: failed to get attention of CPU %u!\n", master);
 300                 return;
 301         }
 302
 303         while (go[MASTER])
 304                 cpu_relax();    /* wait for master to be ready */
 305
 306         spin_lock_irqsave(&itc_sync_lock, flags);
 307         {
 308                 for (i = 0; i < NUM_ROUNDS; ++i) {
 309                         delta = get_delta(&rt, &master_time_stamp);
 310                         if (delta == 0) {
 311                                 done = 1;       /* let's lock on to this... */
 312                                 bound = rt;
 313                         }
 314
 315                         if (!done) {
 316                                 if (i > 0) {
 317                                         adjust_latency += -delta;
 318                                         adj = -delta + adjust_latency/4;
 319                                 } else
 320                                         adj = -delta;
 321
 322                                 ia64_set_itc(ia64_get_itc() + adj);
 323                         }
 324 #if DEBUG_ITC_SYNC
 325                         t[i].rt = rt;
 326                         t[i].master = master_time_stamp;
 327                         t[i].diff = delta;
 328                         t[i].lat = adjust_latency/4;
 329 #endif
 330                 }
 331         }
 332         spin_unlock_irqrestore(&itc_sync_lock, flags);
 333
 334 #if DEBUG_ITC_SYNC
 335         for (i = 0; i < NUM_ROUNDS; ++i)
 336                 printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n",
 337                        t[i].rt, t[i].master, t[i].diff, t[i].lat);
 338 #endif
 339
 340         printk(KERN_INFO "CPU %d: synchronized ITC with CPU %u (last diff %ld cycles, "
 341                "maxerr %lu cycles)\n", smp_processor_id(), master, delta, rt);
 342 }
 343
 344 /*
 345  * Ideally sets up per-cpu profiling hooks.  Doesn't do much now...
 346  */
 347 static inline void smp_setup_percpu_timer(void)
 348 {
 349 }
 350
 351 static void
 352 smp_callin (void)
 353 {
 354         int cpuid, phys_id, itc_master;
 355         struct cpuinfo_ia64 *last_cpuinfo, *this_cpuinfo;
 356         extern void ia64_init_itm(void);
 357         extern volatile int time_keeper_id;
 358
 359         cpuid = smp_processor_id();
 360         phys_id = hard_smp_processor_id();
 361         itc_master = time_keeper_id;
 362
 363         if (cpu_online(cpuid)) {
 364                 printk(KERN_ERR "huh, phys CPU#0x%x, CPU#0x%x already present??\n",
 365                        phys_id, cpuid);
 366                 BUG();
 367         }
 368
 369         fix_b0_for_bsp();
 370
 371         /*
 372          * numa_node_id() works after this.
 373          */
 374         set_numa_node(cpu_to_node_map[cpuid]);
 375         set_numa_mem(local_memory_node(cpu_to_node_map[cpuid]));
 376
 377         spin_lock(&vector_lock);
 378         /* Setup the per cpu irq handling data structures */
 379         __setup_vector_irq(cpuid);
 380         notify_cpu_starting(cpuid);
 381         set_cpu_online(cpuid, true);
 382         per_cpu(cpu_state, cpuid) = CPU_ONLINE;
 383         spin_unlock(&vector_lock);
 384
 385         smp_setup_percpu_timer();
 386
 387         ia64_mca_cmc_vector_setup();    /* Setup vector on AP */
 388
 389         local_irq_enable();
 390
 391         if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
 392                 /*
 393                  * Synchronize the ITC with the BP.  Need to do this after irqs are
 394                  * enabled because ia64_sync_itc() calls smp_call_function_single(), which
 395                  * calls spin_unlock_bh(), which calls spin_unlock_bh(), which calls
 396                  * local_bh_enable(), which bugs out if irqs are not enabled...
 397                  */
 398                 Dprintk("Going to syncup ITC with ITC Master.\n");
 399                 ia64_sync_itc(itc_master);
 400         }
 401
 402         /*
 403          * Get our bogomips.
 404          */
 405         ia64_init_itm();
 406
 407         /*
 408          * Delay calibration can be skipped if new processor is identical to the
 409          * previous processor.
 410          */
 411         last_cpuinfo = cpu_data(cpuid - 1);
 412         this_cpuinfo = local_cpu_data;
 413         if (last_cpuinfo->itc_freq != this_cpuinfo->itc_freq ||
 414             last_cpuinfo->proc_freq != this_cpuinfo->proc_freq ||
 415             last_cpuinfo->features != this_cpuinfo->features ||
 416             last_cpuinfo->revision != this_cpuinfo->revision ||
 417             last_cpuinfo->family != this_cpuinfo->family ||
 418             last_cpuinfo->archrev != this_cpuinfo->archrev ||
 419             last_cpuinfo->model != this_cpuinfo->model)
 420                 calibrate_delay();
 421         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 422
 423         /*
 424          * Allow the master to continue.
 425          */
 426         cpumask_set_cpu(cpuid, &cpu_callin_map);
 427         Dprintk("Stack on CPU %d at about %p\n",cpuid, &cpuid);
 428 }
 429
 430
 431 /*
 432  * Activate a secondary processor.  head.S calls this.
 433  */
 434 int
 435 start_secondary (void *unused)
 436 {
 437         /* Early console may use I/O ports */
 438         ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
 439 #ifndef CONFIG_PRINTK_TIME
 440         Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id());
 441 #endif
 442         efi_map_pal_code();
 443         cpu_init();
 444         preempt_disable();
 445         smp_callin();
 446
 447         cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 448         return 0;
 449 }
 450
 451 static int
 452 do_boot_cpu (int sapicid, int cpu, struct task_struct *idle)
 453 {
 454         int timeout;
 455
 456         task_for_booting_cpu = idle;
 457         Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
 458
 459         set_brendez_area(cpu);
 460         ia64_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0);
 461
 462         /*
 463          * Wait 10s total for the AP to start
 464          */
 465         Dprintk("Waiting on callin_map ...");
 466         for (timeout = 0; timeout < 100000; timeout++) {
 467                 if (cpumask_test_cpu(cpu, &cpu_callin_map))
 468                         break;  /* It has booted */
 469                 barrier(); /* Make sure we re-read cpu_callin_map */
 470                 udelay(100);
 471         }
 472         Dprintk("\n");
 473
 474         if (!cpumask_test_cpu(cpu, &cpu_callin_map)) {
 475                 printk(KERN_ERR "Processor 0x%x/0x%x is stuck.\n", cpu, sapicid);
 476                 ia64_cpu_to_sapicid[cpu] = -1;
 477                 set_cpu_online(cpu, false);  /* was set in smp_callin() */
 478                 return -EINVAL;
 479         }
 480         return 0;
 481 }
 482
 483 static int __init
 484 decay (char *str)
 485 {
 486         int ticks;
 487         get_option (&str, &ticks);
 488         return 1;
 489 }
 490
 491 __setup("decay=", decay);
 492
 493 /*
 494  * Initialize the logical CPU number to SAPICID mapping
 495  */
 496 void __init
 497 smp_build_cpu_map (void)
 498 {
 499         int sapicid, cpu, i;
 500         int boot_cpu_id = hard_smp_processor_id();
 501
 502         for (cpu = 0; cpu < NR_CPUS; cpu++) {
 503                 ia64_cpu_to_sapicid[cpu] = -1;
 504         }
 505
 506         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 507         init_cpu_present(cpumask_of(0));
 508         set_cpu_possible(0, true);
 509         for (cpu = 1, i = 0; i < smp_boot_data.cpu_count; i++) {
 510                 sapicid = smp_boot_data.cpu_phys_id[i];
 511                 if (sapicid == boot_cpu_id)
 512                         continue;
 513                 set_cpu_present(cpu, true);
 514                 set_cpu_possible(cpu, true);
 515                 ia64_cpu_to_sapicid[cpu] = sapicid;
 516                 cpu++;
 517         }
 518 }
 519
 520 /*
 521  * Cycle through the APs sending Wakeup IPIs to boot each.
 522  */
 523 void __init
 524 smp_prepare_cpus (unsigned int max_cpus)
 525 {
 526         int boot_cpu_id = hard_smp_processor_id();
 527
 528         /*
 529          * Initialize the per-CPU profiling counter/multiplier
 530          */
 531
 532         smp_setup_percpu_timer();
 533
 534         cpumask_set_cpu(0, &cpu_callin_map);
 535
 536         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 537         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 538
 539         printk(KERN_INFO "Boot processor id 0x%x/0x%x\n", 0, boot_cpu_id);
 540
 541         current_thread_info()->cpu = 0;
 542
 543         /*
 544          * If SMP should be disabled, then really disable it!
 545          */
 546         if (!max_cpus) {
 547                 printk(KERN_INFO "SMP mode deactivated.\n");
 548                 init_cpu_online(cpumask_of(0));
 549                 init_cpu_present(cpumask_of(0));
 550                 init_cpu_possible(cpumask_of(0));
 551                 return;
 552         }
 553 }
 554
 555 void smp_prepare_boot_cpu(void)
 556 {
 557         set_cpu_online(smp_processor_id(), true);
 558         cpumask_set_cpu(smp_processor_id(), &cpu_callin_map);
 559         set_numa_node(cpu_to_node_map[smp_processor_id()]);
 560         per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
 561 }
 562
 563 #ifdef CONFIG_HOTPLUG_CPU
 564 static inline void
 565 clear_cpu_sibling_map(int cpu)
 566 {
 567         int i;
 568
 569         for_each_cpu(i, &per_cpu(cpu_sibling_map, cpu))
 570                 cpumask_clear_cpu(cpu, &per_cpu(cpu_sibling_map, i));
 571         for_each_cpu(i, &cpu_core_map[cpu])
 572                 cpumask_clear_cpu(cpu, &cpu_core_map[i]);
 573
 574         per_cpu(cpu_sibling_map, cpu) = cpu_core_map[cpu] = CPU_MASK_NONE;
 575 }
 576
 577 static void
 578 remove_siblinginfo(int cpu)
 579 {
 580         int last = 0;
 581
 582         if (cpu_data(cpu)->threads_per_core == 1 &&
 583             cpu_data(cpu)->cores_per_socket == 1) {
 584                 cpumask_clear_cpu(cpu, &cpu_core_map[cpu]);
 585                 cpumask_clear_cpu(cpu, &per_cpu(cpu_sibling_map, cpu));
 586                 return;
 587         }
 588
 589         last = (cpumask_weight(&cpu_core_map[cpu]) == 1 ? 1 : 0);
 590
 591         /* remove it from all sibling map's */
 592         clear_cpu_sibling_map(cpu);
 593 }
 594
 595 extern void fixup_irqs(void);
 596
 597 int migrate_platform_irqs(unsigned int cpu)
 598 {
 599         int new_cpei_cpu;
 600         struct irq_data *data = NULL;
 601         const struct cpumask *mask;
 602         int             retval = 0;
 603
 604         /*
 605          * dont permit CPEI target to removed.
 606          */
 607         if (cpe_vector > 0 && is_cpu_cpei_target(cpu)) {
 608                 printk ("CPU (%d) is CPEI Target\n", cpu);
 609                 if (can_cpei_retarget()) {
 610                         /*
 611                          * Now re-target the CPEI to a different processor
 612                          */
 613                         new_cpei_cpu = cpumask_any(cpu_online_mask);
 614                         mask = cpumask_of(new_cpei_cpu);
 615                         set_cpei_target_cpu(new_cpei_cpu);
 616                         data = irq_get_irq_data(ia64_cpe_irq);
 617                         /*
 618                          * Switch for now, immediately, we need to do fake intr
 619                          * as other interrupts, but need to study CPEI behaviour with
 620                          * polling before making changes.
 621                          */
 622                         if (data && data->chip) {
 623                                 data->chip->irq_disable(data);
 624                                 data->chip->irq_set_affinity(data, mask, false);
 625                                 data->chip->irq_enable(data);
 626                                 printk ("Re-targeting CPEI to cpu %d\n", new_cpei_cpu);
 627                         }
 628                 }
 629                 if (!data) {
 630                         printk ("Unable to retarget CPEI, offline cpu [%d] failed\n", cpu);
 631                         retval = -EBUSY;
 632                 }
 633         }
 634         return retval;
 635 }
 636
 637 /* must be called with cpucontrol mutex held */
 638 int __cpu_disable(void)
 639 {
 640         int cpu = smp_processor_id();
 641
 642         /*
 643          * dont permit boot processor for now
 644          */
 645         if (cpu == 0 && !bsp_remove_ok) {
 646                 printk ("Your platform does not support removal of BSP\n");
 647                 return (-EBUSY);
 648         }
 649
 650         set_cpu_online(cpu, false);
 651
 652         if (migrate_platform_irqs(cpu)) {
 653                 set_cpu_online(cpu, true);
 654                 return -EBUSY;
 655         }
 656
 657         remove_siblinginfo(cpu);
 658         fixup_irqs();
 659         local_flush_tlb_all();
 660         cpumask_clear_cpu(cpu, &cpu_callin_map);
 661         return 0;
 662 }
 663
 664 void __cpu_die(unsigned int cpu)
 665 {
 666         unsigned int i;
 667
 668         for (i = 0; i < 100; i++) {
 669                 /* They ack this in play_dead by setting CPU_DEAD */
 670                 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
 671                 {
 672                         printk ("CPU %d is now offline\n", cpu);
 673                         return;
 674                 }
 675                 msleep(100);
 676         }
 677         printk(KERN_ERR "CPU %u didn't die...\n", cpu);
 678 }
 679 #endif /* CONFIG_HOTPLUG_CPU */
 680
 681 void
 682 smp_cpus_done (unsigned int dummy)
 683 {
 684         int cpu;
 685         unsigned long bogosum = 0;
 686
 687         /*
 688          * Allow the user to impress friends.
 689          */
 690
 691         for_each_online_cpu(cpu) {
 692                 bogosum += cpu_data(cpu)->loops_per_jiffy;
 693         }
 694
 695         printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
 696                (int)num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100);
 697 }
 698
 699 static inline void set_cpu_sibling_map(int cpu)
 700 {
 701         int i;
 702
 703         for_each_online_cpu(i) {
 704                 if ((cpu_data(cpu)->socket_id == cpu_data(i)->socket_id)) {
 705                         cpumask_set_cpu(i, &cpu_core_map[cpu]);
 706                         cpumask_set_cpu(cpu, &cpu_core_map[i]);
 707                         if (cpu_data(cpu)->core_id == cpu_data(i)->core_id) {
 708                                 cpumask_set_cpu(i,
 709                                                 &per_cpu(cpu_sibling_map, cpu));
 710                                 cpumask_set_cpu(cpu,
 711                                                 &per_cpu(cpu_sibling_map, i));
 712                         }
 713                 }
 714         }
 715 }
 716
 717 int
 718 __cpu_up(unsigned int cpu, struct task_struct *tidle)
 719 {
 720         int ret;
 721         int sapicid;
 722
 723         sapicid = ia64_cpu_to_sapicid[cpu];
 724         if (sapicid == -1)
 725                 return -EINVAL;
 726
 727         /*
 728          * Already booted cpu? not valid anymore since we dont
 729          * do idle loop tightspin anymore.
 730          */
 731         if (cpumask_test_cpu(cpu, &cpu_callin_map))
 732                 return -EINVAL;
 733
 734         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 735         /* Processor goes to start_secondary(), sets online flag */
 736         ret = do_boot_cpu(sapicid, cpu, tidle);
 737         if (ret < 0)
 738                 return ret;
 739
 740         if (cpu_data(cpu)->threads_per_core == 1 &&
 741             cpu_data(cpu)->cores_per_socket == 1) {
 742                 cpumask_set_cpu(cpu, &per_cpu(cpu_sibling_map, cpu));
 743                 cpumask_set_cpu(cpu, &cpu_core_map[cpu]);
 744                 return 0;
 745         }
 746
 747         set_cpu_sibling_map(cpu);
 748
 749         return 0;
 750 }
 751
 752 /*
 753  * Assume that CPUs have been discovered by some platform-dependent interface.  For
 754  * SoftSDV/Lion, that would be ACPI.
 755  *
 756  * Setup of the IPI irq handler is done in irq.c:init_IRQ_SMP().
 757  */
 758 void __init
 759 init_smp_config(void)
 760 {
 761         struct fptr {
 762                 unsigned long fp;
 763                 unsigned long gp;
 764         } *ap_startup;
 765         long sal_ret;
 766
 767         /* Tell SAL where to drop the APs.  */
 768         ap_startup = (struct fptr *) start_ap;
 769         sal_ret = ia64_sal_set_vectors(SAL_VECTOR_OS_BOOT_RENDEZ,
 770                                        ia64_tpa(ap_startup->fp), ia64_tpa(ap_startup->gp), 0, 0, 0, 0);
 771         if (sal_ret < 0)
 772                 printk(KERN_ERR "SMP: Can't set SAL AP Boot Rendezvous: %s\n",
 773                        ia64_sal_strerror(sal_ret));
 774 }
 775
 776 /*
 777  * identify_siblings(cpu) gets called from identify_cpu. This populates the
 778  * information related to logical execution units in per_cpu_data structure.
 779  */
 780 void identify_siblings(struct cpuinfo_ia64 *c)
 781 {
 782         long status;
 783         u16 pltid;
 784         pal_logical_to_physical_t info;
 785
 786         status = ia64_pal_logical_to_phys(-1, &info);
 787         if (status != PAL_STATUS_SUCCESS) {
 788                 if (status != PAL_STATUS_UNIMPLEMENTED) {
 789                         printk(KERN_ERR
 790                                 "ia64_pal_logical_to_phys failed with %ld\n",
 791                                 status);
 792                         return;
 793                 }
 794
 795                 info.overview_ppid = 0;
 796                 info.overview_cpp  = 1;
 797                 info.overview_tpc  = 1;
 798         }
 799
 800         status = ia64_sal_physical_id_info(&pltid);
 801         if (status != PAL_STATUS_SUCCESS) {
 802                 if (status != PAL_STATUS_UNIMPLEMENTED)
 803                         printk(KERN_ERR
 804                                 "ia64_sal_pltid failed with %ld\n",
 805                                 status);
 806                 return;
 807         }
 808
 809         c->socket_id =  (pltid << 8) | info.overview_ppid;
 810
 811         if (info.overview_cpp == 1 && info.overview_tpc == 1)
 812                 return;
 813
 814         c->cores_per_socket = info.overview_cpp;
 815         c->threads_per_core = info.overview_tpc;
 816         c->num_log = info.overview_num_log;
 817
 818         c->core_id = info.log1_cid;
 819         c->thread_id = info.log1_tid;
 820 }
 821
 822 /*
 823  * returns non zero, if multi-threading is enabled
 824  * on at least one physical package. Due to hotplug cpu
 825  * and (maxcpus=), all threads may not necessarily be enabled
 826  * even though the processor supports multi-threading.
 827  */
 828 int is_multithreading_enabled(void)
 829 {
 830         int i, j;
 831
 832         for_each_present_cpu(i) {
 833                 for_each_present_cpu(j) {
 834                         if (j == i)
 835                                 continue;
 836                         if ((cpu_data(j)->socket_id == cpu_data(i)->socket_id)) {
 837                                 if (cpu_data(j)->core_id == cpu_data(i)->core_id)
 838                                         return 1;
 839                         }
 840                 }
 841         }
 842         return 0;
 843 }
 844 EXPORT_SYMBOL_GPL(is_multithreading_enabled);