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/io.h>
  49 #include <asm/irq.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
  60 #define SMP_DEBUG 0
  61
  62 #if SMP_DEBUG
  63 #define Dprintk(x...)  printk(x)
  64 #else
  65 #define Dprintk(x...)
  66 #endif
  67
  68 #ifdef CONFIG_HOTPLUG_CPU
  69 #ifdef CONFIG_PERMIT_BSP_REMOVE
  70 #define bsp_remove_ok   1
  71 #else
  72 #define bsp_remove_ok   0
  73 #endif
  74
  75 /*
  76  * Global array allocated for NR_CPUS at boot time
  77  */
  78 struct sal_to_os_boot sal_boot_rendez_state[NR_CPUS];
  79
  80 /*
  81  * start_ap in head.S uses this to store current booting cpu
  82  * info.
  83  */
  84 struct sal_to_os_boot *sal_state_for_booting_cpu = &sal_boot_rendez_state[0];
  85
  86 #define set_brendez_area(x) (sal_state_for_booting_cpu = &sal_boot_rendez_state[(x)]);
  87
  88 #else
  89 #define set_brendez_area(x)
  90 #endif
  91
  92
  93 /*
  94  * ITC synchronization related stuff:
  95  */
  96 #define MASTER  (0)
  97 #define SLAVE   (SMP_CACHE_BYTES/8)
  98
  99 #define NUM_ROUNDS      64      /* magic value */
 100 #define NUM_ITERS       5       /* likewise */
 101
 102 static DEFINE_SPINLOCK(itc_sync_lock);
 103 static volatile unsigned long go[SLAVE + 1];
 104
 105 #define DEBUG_ITC_SYNC  0
 106
 107 extern void start_ap (void);
 108 extern unsigned long ia64_iobase;
 109
 110 struct task_struct *task_for_booting_cpu;
 111
 112 /*
 113  * State for each CPU
 114  */
 115 DEFINE_PER_CPU(int, cpu_state);
 116
 117 cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
 118 EXPORT_SYMBOL(cpu_core_map);
 119 DEFINE_PER_CPU_SHARED_ALIGNED(cpumask_t, cpu_sibling_map);
 120 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
 121
 122 int smp_num_siblings = 1;
 123
 124 /* which logical CPU number maps to which CPU (physical APIC ID) */
 125 volatile int ia64_cpu_to_sapicid[NR_CPUS];
 126 EXPORT_SYMBOL(ia64_cpu_to_sapicid);
 127
 128 static cpumask_t cpu_callin_map;
 129
 130 struct smp_boot_data smp_boot_data __initdata;
 131
 132 unsigned long ap_wakeup_vector = -1; /* External Int use to wakeup APs */
 133
 134 char __initdata no_int_routing;
 135
 136 unsigned char smp_int_redirect; /* are INT and IPI redirectable by the chipset? */
 137
 138 #ifdef CONFIG_FORCE_CPEI_RETARGET
 139 #define CPEI_OVERRIDE_DEFAULT   (1)
 140 #else
 141 #define CPEI_OVERRIDE_DEFAULT   (0)
 142 #endif
 143
 144 unsigned int force_cpei_retarget = CPEI_OVERRIDE_DEFAULT;
 145
 146 static int __init
 147 cmdl_force_cpei(char *str)
 148 {
 149         int value=0;
 150
 151         get_option (&str, &value);
 152         force_cpei_retarget = value;
 153
 154         return 1;
 155 }
 156
 157 __setup("force_cpei=", cmdl_force_cpei);
 158
 159 static int __init
 160 nointroute (char *str)
 161 {
 162         no_int_routing = 1;
 163         printk ("no_int_routing on\n");
 164         return 1;
 165 }
 166
 167 __setup("nointroute", nointroute);
 168
 169 static void fix_b0_for_bsp(void)
 170 {
 171 #ifdef CONFIG_HOTPLUG_CPU
 172         int cpuid;
 173         static int fix_bsp_b0 = 1;
 174
 175         cpuid = smp_processor_id();
 176
 177         /*
 178          * Cache the b0 value on the first AP that comes up
 179          */
 180         if (!(fix_bsp_b0 && cpuid))
 181                 return;
 182
 183         sal_boot_rendez_state[0].br[0] = sal_boot_rendez_state[cpuid].br[0];
 184         printk ("Fixed BSP b0 value from CPU %d\n", cpuid);
 185
 186         fix_bsp_b0 = 0;
 187 #endif
 188 }
 189
 190 void
 191 sync_master (void *arg)
 192 {
 193         unsigned long flags, i;
 194
 195         go[MASTER] = 0;
 196
 197         local_irq_save(flags);
 198         {
 199                 for (i = 0; i < NUM_ROUNDS*NUM_ITERS; ++i) {
 200                         while (!go[MASTER])
 201                                 cpu_relax();
 202                         go[MASTER] = 0;
 203                         go[SLAVE] = ia64_get_itc();
 204                 }
 205         }
 206         local_irq_restore(flags);
 207 }
 208
 209 /*
 210  * Return the number of cycles by which our itc differs from the itc on the master
 211  * (time-keeper) CPU.  A positive number indicates our itc is ahead of the master,
 212  * negative that it is behind.
 213  */
 214 static inline long
 215 get_delta (long *rt, long *master)
 216 {
 217         unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0;
 218         unsigned long tcenter, t0, t1, tm;
 219         long i;
 220
 221         for (i = 0; i < NUM_ITERS; ++i) {
 222                 t0 = ia64_get_itc();
 223                 go[MASTER] = 1;
 224                 while (!(tm = go[SLAVE]))
 225                         cpu_relax();
 226                 go[SLAVE] = 0;
 227                 t1 = ia64_get_itc();
 228
 229                 if (t1 - t0 < best_t1 - best_t0)
 230                         best_t0 = t0, best_t1 = t1, best_tm = tm;
 231         }
 232
 233         *rt = best_t1 - best_t0;
 234         *master = best_tm - best_t0;
 235
 236         /* average best_t0 and best_t1 without overflow: */
 237         tcenter = (best_t0/2 + best_t1/2);
 238         if (best_t0 % 2 + best_t1 % 2 == 2)
 239                 ++tcenter;
 240         return tcenter - best_tm;
 241 }
 242
 243 /*
 244  * Synchronize ar.itc of the current (slave) CPU with the ar.itc of the MASTER CPU
 245  * (normally the time-keeper CPU).  We use a closed loop to eliminate the possibility of
 246  * unaccounted-for errors (such as getting a machine check in the middle of a calibration
 247  * step).  The basic idea is for the slave to ask the master what itc value it has and to
 248  * read its own itc before and after the master responds.  Each iteration gives us three
 249  * timestamps:
 250  *
 251  *      slave           master
 252  *
 253  *      t0 ---\
 254  *             ---\
 255  *                 --->
 256  *                      tm
 257  *                 /---
 258  *             /---
 259  *      t1 <---
 260  *
 261  *
 262  * The goal is to adjust the slave's ar.itc such that tm falls exactly half-way between t0
 263  * and t1.  If we achieve this, the clocks are synchronized provided the interconnect
 264  * between the slave and the master is symmetric.  Even if the interconnect were
 265  * asymmetric, we would still know that the synchronization error is smaller than the
 266  * roundtrip latency (t0 - t1).
 267  *
 268  * When the interconnect is quiet and symmetric, this lets us synchronize the itc to
 269  * within one or two cycles.  However, we can only *guarantee* that the synchronization is
 270  * accurate to within a round-trip time, which is typically in the range of several
 271  * hundred cycles (e.g., ~500 cycles).  In practice, this means that the itc's are usually
 272  * almost perfectly synchronized, but we shouldn't assume that the accuracy is much better
 273  * than half a micro second or so.
 274  */
 275 void
 276 ia64_sync_itc (unsigned int master)
 277 {
 278         long i, delta, adj, adjust_latency = 0, done = 0;
 279         unsigned long flags, rt, master_time_stamp, bound;
 280 #if DEBUG_ITC_SYNC
 281         struct {
 282                 long rt;        /* roundtrip time */
 283                 long master;    /* master's timestamp */
 284                 long diff;      /* difference between midpoint and master's timestamp */
 285                 long lat;       /* estimate of itc adjustment latency */
 286         } t[NUM_ROUNDS];
 287 #endif
 288
 289         /*
 290          * Make sure local timer ticks are disabled while we sync.  If
 291          * they were enabled, we'd have to worry about nasty issues
 292          * like setting the ITC ahead of (or a long time before) the
 293          * next scheduled tick.
 294          */
 295         BUG_ON((ia64_get_itv() & (1 << 16)) == 0);
 296
 297         go[MASTER] = 1;
 298
 299         if (smp_call_function_single(master, sync_master, NULL, 0) < 0) {
 300                 printk(KERN_ERR "sync_itc: failed to get attention of CPU %u!\n", master);
 301                 return;
 302         }
 303
 304         while (go[MASTER])
 305                 cpu_relax();    /* wait for master to be ready */
 306
 307         spin_lock_irqsave(&itc_sync_lock, flags);
 308         {
 309                 for (i = 0; i < NUM_ROUNDS; ++i) {
 310                         delta = get_delta(&rt, &master_time_stamp);
 311                         if (delta == 0) {
 312                                 done = 1;       /* let's lock on to this... */
 313                                 bound = rt;
 314                         }
 315
 316                         if (!done) {
 317                                 if (i > 0) {
 318                                         adjust_latency += -delta;
 319                                         adj = -delta + adjust_latency/4;
 320                                 } else
 321                                         adj = -delta;
 322
 323                                 ia64_set_itc(ia64_get_itc() + adj);
 324                         }
 325 #if DEBUG_ITC_SYNC
 326                         t[i].rt = rt;
 327                         t[i].master = master_time_stamp;
 328                         t[i].diff = delta;
 329                         t[i].lat = adjust_latency/4;
 330 #endif
 331                 }
 332         }
 333         spin_unlock_irqrestore(&itc_sync_lock, flags);
 334
 335 #if DEBUG_ITC_SYNC
 336         for (i = 0; i < NUM_ROUNDS; ++i)
 337                 printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n",
 338                        t[i].rt, t[i].master, t[i].diff, t[i].lat);
 339 #endif
 340
 341         printk(KERN_INFO "CPU %d: synchronized ITC with CPU %u (last diff %ld cycles, "
 342                "maxerr %lu cycles)\n", smp_processor_id(), master, delta, rt);
 343 }
 344
 345 /*
 346  * Ideally sets up per-cpu profiling hooks.  Doesn't do much now...
 347  */
 348 static inline void smp_setup_percpu_timer(void)
 349 {
 350 }
 351
 352 static void
 353 smp_callin (void)
 354 {
 355         int cpuid, phys_id, itc_master;
 356         struct cpuinfo_ia64 *last_cpuinfo, *this_cpuinfo;
 357         extern void ia64_init_itm(void);
 358         extern volatile int time_keeper_id;
 359
 360 #ifdef CONFIG_PERFMON
 361         extern void pfm_init_percpu(void);
 362 #endif
 363
 364         cpuid = smp_processor_id();
 365         phys_id = hard_smp_processor_id();
 366         itc_master = time_keeper_id;
 367
 368         if (cpu_online(cpuid)) {
 369                 printk(KERN_ERR "huh, phys CPU#0x%x, CPU#0x%x already present??\n",
 370                        phys_id, cpuid);
 371                 BUG();
 372         }
 373
 374         fix_b0_for_bsp();
 375
 376         /*
 377          * numa_node_id() works after this.
 378          */
 379         set_numa_node(cpu_to_node_map[cpuid]);
 380         set_numa_mem(local_memory_node(cpu_to_node_map[cpuid]));
 381
 382         spin_lock(&vector_lock);
 383         /* Setup the per cpu irq handling data structures */
 384         __setup_vector_irq(cpuid);
 385         notify_cpu_starting(cpuid);
 386         set_cpu_online(cpuid, true);
 387         per_cpu(cpu_state, cpuid) = CPU_ONLINE;
 388         spin_unlock(&vector_lock);
 389
 390         smp_setup_percpu_timer();
 391
 392         ia64_mca_cmc_vector_setup();    /* Setup vector on AP */
 393
 394 #ifdef CONFIG_PERFMON
 395         pfm_init_percpu();
 396 #endif
 397
 398         local_irq_enable();
 399
 400         if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
 401                 /*
 402                  * Synchronize the ITC with the BP.  Need to do this after irqs are
 403                  * enabled because ia64_sync_itc() calls smp_call_function_single(), which
 404                  * calls spin_unlock_bh(), which calls spin_unlock_bh(), which calls
 405                  * local_bh_enable(), which bugs out if irqs are not enabled...
 406                  */
 407                 Dprintk("Going to syncup ITC with ITC Master.\n");
 408                 ia64_sync_itc(itc_master);
 409         }
 410
 411         /*
 412          * Get our bogomips.
 413          */
 414         ia64_init_itm();
 415
 416         /*
 417          * Delay calibration can be skipped if new processor is identical to the
 418          * previous processor.
 419          */
 420         last_cpuinfo = cpu_data(cpuid - 1);
 421         this_cpuinfo = local_cpu_data;
 422         if (last_cpuinfo->itc_freq != this_cpuinfo->itc_freq ||
 423             last_cpuinfo->proc_freq != this_cpuinfo->proc_freq ||
 424             last_cpuinfo->features != this_cpuinfo->features ||
 425             last_cpuinfo->revision != this_cpuinfo->revision ||
 426             last_cpuinfo->family != this_cpuinfo->family ||
 427             last_cpuinfo->archrev != this_cpuinfo->archrev ||
 428             last_cpuinfo->model != this_cpuinfo->model)
 429                 calibrate_delay();
 430         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 431
 432         /*
 433          * Allow the master to continue.
 434          */
 435         cpumask_set_cpu(cpuid, &cpu_callin_map);
 436         Dprintk("Stack on CPU %d at about %p\n",cpuid, &cpuid);
 437 }
 438
 439
 440 /*
 441  * Activate a secondary processor.  head.S calls this.
 442  */
 443 int
 444 start_secondary (void *unused)
 445 {
 446         /* Early console may use I/O ports */
 447         ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
 448 #ifndef CONFIG_PRINTK_TIME
 449         Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id());
 450 #endif
 451         efi_map_pal_code();
 452         cpu_init();
 453         preempt_disable();
 454         smp_callin();
 455
 456         cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 457         return 0;
 458 }
 459
 460 static int
 461 do_boot_cpu (int sapicid, int cpu, struct task_struct *idle)
 462 {
 463         int timeout;
 464
 465         task_for_booting_cpu = idle;
 466         Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
 467
 468         set_brendez_area(cpu);
 469         ia64_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0);
 470
 471         /*
 472          * Wait 10s total for the AP to start
 473          */
 474         Dprintk("Waiting on callin_map ...");
 475         for (timeout = 0; timeout < 100000; timeout++) {
 476                 if (cpumask_test_cpu(cpu, &cpu_callin_map))
 477                         break;  /* It has booted */
 478                 barrier(); /* Make sure we re-read cpu_callin_map */
 479                 udelay(100);
 480         }
 481         Dprintk("\n");
 482
 483         if (!cpumask_test_cpu(cpu, &cpu_callin_map)) {
 484                 printk(KERN_ERR "Processor 0x%x/0x%x is stuck.\n", cpu, sapicid);
 485                 ia64_cpu_to_sapicid[cpu] = -1;
 486                 set_cpu_online(cpu, false);  /* was set in smp_callin() */
 487                 return -EINVAL;
 488         }
 489         return 0;
 490 }
 491
 492 static int __init
 493 decay (char *str)
 494 {
 495         int ticks;
 496         get_option (&str, &ticks);
 497         return 1;
 498 }
 499
 500 __setup("decay=", decay);
 501
 502 /*
 503  * Initialize the logical CPU number to SAPICID mapping
 504  */
 505 void __init
 506 smp_build_cpu_map (void)
 507 {
 508         int sapicid, cpu, i;
 509         int boot_cpu_id = hard_smp_processor_id();
 510
 511         for (cpu = 0; cpu < NR_CPUS; cpu++) {
 512                 ia64_cpu_to_sapicid[cpu] = -1;
 513         }
 514
 515         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 516         init_cpu_present(cpumask_of(0));
 517         set_cpu_possible(0, true);
 518         for (cpu = 1, i = 0; i < smp_boot_data.cpu_count; i++) {
 519                 sapicid = smp_boot_data.cpu_phys_id[i];
 520                 if (sapicid == boot_cpu_id)
 521                         continue;
 522                 set_cpu_present(cpu, true);
 523                 set_cpu_possible(cpu, true);
 524                 ia64_cpu_to_sapicid[cpu] = sapicid;
 525                 cpu++;
 526         }
 527 }
 528
 529 /*
 530  * Cycle through the APs sending Wakeup IPIs to boot each.
 531  */
 532 void __init
 533 smp_prepare_cpus (unsigned int max_cpus)
 534 {
 535         int boot_cpu_id = hard_smp_processor_id();
 536
 537         /*
 538          * Initialize the per-CPU profiling counter/multiplier
 539          */
 540
 541         smp_setup_percpu_timer();
 542
 543         cpumask_set_cpu(0, &cpu_callin_map);
 544
 545         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 546         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 547
 548         printk(KERN_INFO "Boot processor id 0x%x/0x%x\n", 0, boot_cpu_id);
 549
 550         current_thread_info()->cpu = 0;
 551
 552         /*
 553          * If SMP should be disabled, then really disable it!
 554          */
 555         if (!max_cpus) {
 556                 printk(KERN_INFO "SMP mode deactivated.\n");
 557                 init_cpu_online(cpumask_of(0));
 558                 init_cpu_present(cpumask_of(0));
 559                 init_cpu_possible(cpumask_of(0));
 560                 return;
 561         }
 562 }
 563
 564 void smp_prepare_boot_cpu(void)
 565 {
 566         set_cpu_online(smp_processor_id(), true);
 567         cpumask_set_cpu(smp_processor_id(), &cpu_callin_map);
 568         set_numa_node(cpu_to_node_map[smp_processor_id()]);
 569         per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
 570 }
 571
 572 #ifdef CONFIG_HOTPLUG_CPU
 573 static inline void
 574 clear_cpu_sibling_map(int cpu)
 575 {
 576         int i;
 577
 578         for_each_cpu(i, &per_cpu(cpu_sibling_map, cpu))
 579                 cpumask_clear_cpu(cpu, &per_cpu(cpu_sibling_map, i));
 580         for_each_cpu(i, &cpu_core_map[cpu])
 581                 cpumask_clear_cpu(cpu, &cpu_core_map[i]);
 582
 583         per_cpu(cpu_sibling_map, cpu) = cpu_core_map[cpu] = CPU_MASK_NONE;
 584 }
 585
 586 static void
 587 remove_siblinginfo(int cpu)
 588 {
 589         int last = 0;
 590
 591         if (cpu_data(cpu)->threads_per_core == 1 &&
 592             cpu_data(cpu)->cores_per_socket == 1) {
 593                 cpumask_clear_cpu(cpu, &cpu_core_map[cpu]);
 594                 cpumask_clear_cpu(cpu, &per_cpu(cpu_sibling_map, cpu));
 595                 return;
 596         }
 597
 598         last = (cpumask_weight(&cpu_core_map[cpu]) == 1 ? 1 : 0);
 599
 600         /* remove it from all sibling map's */
 601         clear_cpu_sibling_map(cpu);
 602 }
 603
 604 extern void fixup_irqs(void);
 605
 606 int migrate_platform_irqs(unsigned int cpu)
 607 {
 608         int new_cpei_cpu;
 609         struct irq_data *data = NULL;
 610         const struct cpumask *mask;
 611         int             retval = 0;
 612
 613         /*
 614          * dont permit CPEI target to removed.
 615          */
 616         if (cpe_vector > 0 && is_cpu_cpei_target(cpu)) {
 617                 printk ("CPU (%d) is CPEI Target\n", cpu);
 618                 if (can_cpei_retarget()) {
 619                         /*
 620                          * Now re-target the CPEI to a different processor
 621                          */
 622                         new_cpei_cpu = cpumask_any(cpu_online_mask);
 623                         mask = cpumask_of(new_cpei_cpu);
 624                         set_cpei_target_cpu(new_cpei_cpu);
 625                         data = irq_get_irq_data(ia64_cpe_irq);
 626                         /*
 627                          * Switch for now, immediately, we need to do fake intr
 628                          * as other interrupts, but need to study CPEI behaviour with
 629                          * polling before making changes.
 630                          */
 631                         if (data && data->chip) {
 632                                 data->chip->irq_disable(data);
 633                                 data->chip->irq_set_affinity(data, mask, false);
 634                                 data->chip->irq_enable(data);
 635                                 printk ("Re-targeting CPEI to cpu %d\n", new_cpei_cpu);
 636                         }
 637                 }
 638                 if (!data) {
 639                         printk ("Unable to retarget CPEI, offline cpu [%d] failed\n", cpu);
 640                         retval = -EBUSY;
 641                 }
 642         }
 643         return retval;
 644 }
 645
 646 /* must be called with cpucontrol mutex held */
 647 int __cpu_disable(void)
 648 {
 649         int cpu = smp_processor_id();
 650
 651         /*
 652          * dont permit boot processor for now
 653          */
 654         if (cpu == 0 && !bsp_remove_ok) {
 655                 printk ("Your platform does not support removal of BSP\n");
 656                 return (-EBUSY);
 657         }
 658
 659         set_cpu_online(cpu, false);
 660
 661         if (migrate_platform_irqs(cpu)) {
 662                 set_cpu_online(cpu, true);
 663                 return -EBUSY;
 664         }
 665
 666         remove_siblinginfo(cpu);
 667         fixup_irqs();
 668         local_flush_tlb_all();
 669         cpumask_clear_cpu(cpu, &cpu_callin_map);
 670         return 0;
 671 }
 672
 673 void __cpu_die(unsigned int cpu)
 674 {
 675         unsigned int i;
 676
 677         for (i = 0; i < 100; i++) {
 678                 /* They ack this in play_dead by setting CPU_DEAD */
 679                 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
 680                 {
 681                         printk ("CPU %d is now offline\n", cpu);
 682                         return;
 683                 }
 684                 msleep(100);
 685         }
 686         printk(KERN_ERR "CPU %u didn't die...\n", cpu);
 687 }
 688 #endif /* CONFIG_HOTPLUG_CPU */
 689
 690 void
 691 smp_cpus_done (unsigned int dummy)
 692 {
 693         int cpu;
 694         unsigned long bogosum = 0;
 695
 696         /*
 697          * Allow the user to impress friends.
 698          */
 699
 700         for_each_online_cpu(cpu) {
 701                 bogosum += cpu_data(cpu)->loops_per_jiffy;
 702         }
 703
 704         printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
 705                (int)num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100);
 706 }
 707
 708 static inline void set_cpu_sibling_map(int cpu)
 709 {
 710         int i;
 711
 712         for_each_online_cpu(i) {
 713                 if ((cpu_data(cpu)->socket_id == cpu_data(i)->socket_id)) {
 714                         cpumask_set_cpu(i, &cpu_core_map[cpu]);
 715                         cpumask_set_cpu(cpu, &cpu_core_map[i]);
 716                         if (cpu_data(cpu)->core_id == cpu_data(i)->core_id) {
 717                                 cpumask_set_cpu(i,
 718                                                 &per_cpu(cpu_sibling_map, cpu));
 719                                 cpumask_set_cpu(cpu,
 720                                                 &per_cpu(cpu_sibling_map, i));
 721                         }
 722                 }
 723         }
 724 }
 725
 726 int
 727 __cpu_up(unsigned int cpu, struct task_struct *tidle)
 728 {
 729         int ret;
 730         int sapicid;
 731
 732         sapicid = ia64_cpu_to_sapicid[cpu];
 733         if (sapicid == -1)
 734                 return -EINVAL;
 735
 736         /*
 737          * Already booted cpu? not valid anymore since we dont
 738          * do idle loop tightspin anymore.
 739          */
 740         if (cpumask_test_cpu(cpu, &cpu_callin_map))
 741                 return -EINVAL;
 742
 743         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 744         /* Processor goes to start_secondary(), sets online flag */
 745         ret = do_boot_cpu(sapicid, cpu, tidle);
 746         if (ret < 0)
 747                 return ret;
 748
 749         if (cpu_data(cpu)->threads_per_core == 1 &&
 750             cpu_data(cpu)->cores_per_socket == 1) {
 751                 cpumask_set_cpu(cpu, &per_cpu(cpu_sibling_map, cpu));
 752                 cpumask_set_cpu(cpu, &cpu_core_map[cpu]);
 753                 return 0;
 754         }
 755
 756         set_cpu_sibling_map(cpu);
 757
 758         return 0;
 759 }
 760
 761 /*
 762  * Assume that CPUs have been discovered by some platform-dependent interface.  For
 763  * SoftSDV/Lion, that would be ACPI.
 764  *
 765  * Setup of the IPI irq handler is done in irq.c:init_IRQ_SMP().
 766  */
 767 void __init
 768 init_smp_config(void)
 769 {
 770         struct fptr {
 771                 unsigned long fp;
 772                 unsigned long gp;
 773         } *ap_startup;
 774         long sal_ret;
 775
 776         /* Tell SAL where to drop the APs.  */
 777         ap_startup = (struct fptr *) start_ap;
 778         sal_ret = ia64_sal_set_vectors(SAL_VECTOR_OS_BOOT_RENDEZ,
 779                                        ia64_tpa(ap_startup->fp), ia64_tpa(ap_startup->gp), 0, 0, 0, 0);
 780         if (sal_ret < 0)
 781                 printk(KERN_ERR "SMP: Can't set SAL AP Boot Rendezvous: %s\n",
 782                        ia64_sal_strerror(sal_ret));
 783 }
 784
 785 /*
 786  * identify_siblings(cpu) gets called from identify_cpu. This populates the
 787  * information related to logical execution units in per_cpu_data structure.
 788  */
 789 void identify_siblings(struct cpuinfo_ia64 *c)
 790 {
 791         long status;
 792         u16 pltid;
 793         pal_logical_to_physical_t info;
 794
 795         status = ia64_pal_logical_to_phys(-1, &info);
 796         if (status != PAL_STATUS_SUCCESS) {
 797                 if (status != PAL_STATUS_UNIMPLEMENTED) {
 798                         printk(KERN_ERR
 799                                 "ia64_pal_logical_to_phys failed with %ld\n",
 800                                 status);
 801                         return;
 802                 }
 803
 804                 info.overview_ppid = 0;
 805                 info.overview_cpp  = 1;
 806                 info.overview_tpc  = 1;
 807         }
 808
 809         status = ia64_sal_physical_id_info(&pltid);
 810         if (status != PAL_STATUS_SUCCESS) {
 811                 if (status != PAL_STATUS_UNIMPLEMENTED)
 812                         printk(KERN_ERR
 813                                 "ia64_sal_pltid failed with %ld\n",
 814                                 status);
 815                 return;
 816         }
 817
 818         c->socket_id =  (pltid << 8) | info.overview_ppid;
 819
 820         if (info.overview_cpp == 1 && info.overview_tpc == 1)
 821                 return;
 822
 823         c->cores_per_socket = info.overview_cpp;
 824         c->threads_per_core = info.overview_tpc;
 825         c->num_log = info.overview_num_log;
 826
 827         c->core_id = info.log1_cid;
 828         c->thread_id = info.log1_tid;
 829 }
 830
 831 /*
 832  * returns non zero, if multi-threading is enabled
 833  * on at least one physical package. Due to hotplug cpu
 834  * and (maxcpus=), all threads may not necessarily be enabled
 835  * even though the processor supports multi-threading.
 836  */
 837 int is_multithreading_enabled(void)
 838 {
 839         int i, j;
 840
 841         for_each_present_cpu(i) {
 842                 for_each_present_cpu(j) {
 843                         if (j == i)
 844                                 continue;
 845                         if ((cpu_data(j)->socket_id == cpu_data(i)->socket_id)) {
 846                                 if (cpu_data(j)->core_id == cpu_data(i)->core_id)
 847                                         return 1;
 848                         }
 849                 }
 850         }
 851         return 0;
 852 }
 853 EXPORT_SYMBOL_GPL(is_multithreading_enabled);