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 #include <linux/config.h>
  25
  26 #include <linux/module.h>
  27 #include <linux/acpi.h>
  28 #include <linux/bootmem.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/smp_lock.h>
  40 #include <linux/spinlock.h>
  41 #include <linux/efi.h>
  42 #include <linux/percpu.h>
  43 #include <linux/bitops.h>
  44
  45 #include <asm/atomic.h>
  46 #include <asm/cache.h>
  47 #include <asm/current.h>
  48 #include <asm/delay.h>
  49 #include <asm/ia32.h>
  50 #include <asm/io.h>
  51 #include <asm/irq.h>
  52 #include <asm/machvec.h>
  53 #include <asm/mca.h>
  54 #include <asm/page.h>
  55 #include <asm/pgalloc.h>
  56 #include <asm/pgtable.h>
  57 #include <asm/processor.h>
  58 #include <asm/ptrace.h>
  59 #include <asm/sal.h>
  60 #include <asm/system.h>
  61 #include <asm/tlbflush.h>
  62 #include <asm/unistd.h>
  63
  64 #define SMP_DEBUG 0
  65
  66 #if SMP_DEBUG
  67 #define Dprintk(x...)  printk(x)
  68 #else
  69 #define Dprintk(x...)
  70 #endif
  71
  72 #ifdef CONFIG_HOTPLUG_CPU
  73 #ifdef CONFIG_PERMIT_BSP_REMOVE
  74 #define bsp_remove_ok   1
  75 #else
  76 #define bsp_remove_ok   0
  77 #endif
  78
  79 /*
  80  * Store all idle threads, this can be reused instead of creating
  81  * a new thread. Also avoids complicated thread destroy functionality
  82  * for idle threads.
  83  */
  84 struct task_struct *idle_thread_array[NR_CPUS];
  85
  86 /*
  87  * Global array allocated for NR_CPUS at boot time
  88  */
  89 struct sal_to_os_boot sal_boot_rendez_state[NR_CPUS];
  90
  91 /*
  92  * start_ap in head.S uses this to store current booting cpu
  93  * info.
  94  */
  95 struct sal_to_os_boot *sal_state_for_booting_cpu = &sal_boot_rendez_state[0];
  96
  97 #define set_brendez_area(x) (sal_state_for_booting_cpu = &sal_boot_rendez_state[(x)]);
  98
  99 #define get_idle_for_cpu(x)             (idle_thread_array[(x)])
 100 #define set_idle_for_cpu(x,p)   (idle_thread_array[(x)] = (p))
 101
 102 #else
 103
 104 #define get_idle_for_cpu(x)             (NULL)
 105 #define set_idle_for_cpu(x,p)
 106 #define set_brendez_area(x)
 107 #endif
 108
 109
 110 /*
 111  * ITC synchronization related stuff:
 112  */
 113 #define MASTER  (0)
 114 #define SLAVE   (SMP_CACHE_BYTES/8)
 115
 116 #define NUM_ROUNDS      64      /* magic value */
 117 #define NUM_ITERS       5       /* likewise */
 118
 119 static DEFINE_SPINLOCK(itc_sync_lock);
 120 static volatile unsigned long go[SLAVE + 1];
 121
 122 #define DEBUG_ITC_SYNC  0
 123
 124 extern void __devinit calibrate_delay (void);
 125 extern void start_ap (void);
 126 extern unsigned long ia64_iobase;
 127
 128 task_t *task_for_booting_cpu;
 129
 130 /*
 131  * State for each CPU
 132  */
 133 DEFINE_PER_CPU(int, cpu_state);
 134
 135 /* Bitmasks of currently online, and possible CPUs */
 136 cpumask_t cpu_online_map;
 137 EXPORT_SYMBOL(cpu_online_map);
 138 cpumask_t cpu_possible_map = CPU_MASK_NONE;
 139 EXPORT_SYMBOL(cpu_possible_map);
 140
 141 cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
 142 cpumask_t cpu_sibling_map[NR_CPUS] __cacheline_aligned;
 143 int smp_num_siblings = 1;
 144 int smp_num_cpucores = 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 __devinit
 376 smp_callin (void)
 377 {
 378         int cpuid, phys_id, itc_master;
 379         extern void ia64_init_itm(void);
 380         extern volatile int time_keeper_id;
 381
 382 #ifdef CONFIG_PERFMON
 383         extern void pfm_init_percpu(void);
 384 #endif
 385
 386         cpuid = smp_processor_id();
 387         phys_id = hard_smp_processor_id();
 388         itc_master = time_keeper_id;
 389
 390         if (cpu_online(cpuid)) {
 391                 printk(KERN_ERR "huh, phys CPU#0x%x, CPU#0x%x already present??\n",
 392                        phys_id, cpuid);
 393                 BUG();
 394         }
 395
 396         fix_b0_for_bsp();
 397
 398         lock_ipi_calllock();
 399         cpu_set(cpuid, cpu_online_map);
 400         unlock_ipi_calllock();
 401         per_cpu(cpu_state, cpuid) = CPU_ONLINE;
 402
 403         smp_setup_percpu_timer();
 404
 405         ia64_mca_cmc_vector_setup();    /* Setup vector on AP */
 406
 407 #ifdef CONFIG_PERFMON
 408         pfm_init_percpu();
 409 #endif
 410
 411         local_irq_enable();
 412
 413         if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
 414                 /*
 415                  * Synchronize the ITC with the BP.  Need to do this after irqs are
 416                  * enabled because ia64_sync_itc() calls smp_call_function_single(), which
 417                  * calls spin_unlock_bh(), which calls spin_unlock_bh(), which calls
 418                  * local_bh_enable(), which bugs out if irqs are not enabled...
 419                  */
 420                 Dprintk("Going to syncup ITC with ITC Master.\n");
 421                 ia64_sync_itc(itc_master);
 422         }
 423
 424         /*
 425          * Get our bogomips.
 426          */
 427         ia64_init_itm();
 428         calibrate_delay();
 429         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 430
 431 #ifdef CONFIG_IA32_SUPPORT
 432         ia32_gdt_init();
 433 #endif
 434
 435         /*
 436          * Allow the master to continue.
 437          */
 438         cpu_set(cpuid, cpu_callin_map);
 439         Dprintk("Stack on CPU %d at about %p\n",cpuid, &cpuid);
 440 }
 441
 442
 443 /*
 444  * Activate a secondary processor.  head.S calls this.
 445  */
 446 int __devinit
 447 start_secondary (void *unused)
 448 {
 449         /* Early console may use I/O ports */
 450         ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
 451         Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id());
 452         efi_map_pal_code();
 453         cpu_init();
 454         preempt_disable();
 455         smp_callin();
 456
 457         cpu_idle();
 458         return 0;
 459 }
 460
 461 struct pt_regs * __devinit idle_regs(struct pt_regs *regs)
 462 {
 463         return NULL;
 464 }
 465
 466 struct create_idle {
 467         struct task_struct *idle;
 468         struct completion done;
 469         int cpu;
 470 };
 471
 472 void
 473 do_fork_idle(void *_c_idle)
 474 {
 475         struct create_idle *c_idle = _c_idle;
 476
 477         c_idle->idle = fork_idle(c_idle->cpu);
 478         complete(&c_idle->done);
 479 }
 480
 481 static int __devinit
 482 do_boot_cpu (int sapicid, int cpu)
 483 {
 484         int timeout;
 485         struct create_idle c_idle = {
 486                 .cpu    = cpu,
 487                 .done   = COMPLETION_INITIALIZER(c_idle.done),
 488         };
 489         DECLARE_WORK(work, do_fork_idle, &c_idle);
 490
 491         c_idle.idle = get_idle_for_cpu(cpu);
 492         if (c_idle.idle) {
 493                 init_idle(c_idle.idle, cpu);
 494                 goto do_rest;
 495         }
 496
 497         /*
 498          * We can't use kernel_thread since we must avoid to reschedule the child.
 499          */
 500         if (!keventd_up() || current_is_keventd())
 501                 work.func(work.data);
 502         else {
 503                 schedule_work(&work);
 504                 wait_for_completion(&c_idle.done);
 505         }
 506
 507         if (IS_ERR(c_idle.idle))
 508                 panic("failed fork for CPU %d", cpu);
 509
 510         set_idle_for_cpu(cpu, c_idle.idle);
 511
 512 do_rest:
 513         task_for_booting_cpu = c_idle.idle;
 514
 515         Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
 516
 517         set_brendez_area(cpu);
 518         platform_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0);
 519
 520         /*
 521          * Wait 10s total for the AP to start
 522          */
 523         Dprintk("Waiting on callin_map ...");
 524         for (timeout = 0; timeout < 100000; timeout++) {
 525                 if (cpu_isset(cpu, cpu_callin_map))
 526                         break;  /* It has booted */
 527                 udelay(100);
 528         }
 529         Dprintk("\n");
 530
 531         if (!cpu_isset(cpu, cpu_callin_map)) {
 532                 printk(KERN_ERR "Processor 0x%x/0x%x is stuck.\n", cpu, sapicid);
 533                 ia64_cpu_to_sapicid[cpu] = -1;
 534                 cpu_clear(cpu, cpu_online_map);  /* was set in smp_callin() */
 535                 return -EINVAL;
 536         }
 537         return 0;
 538 }
 539
 540 static int __init
 541 decay (char *str)
 542 {
 543         int ticks;
 544         get_option (&str, &ticks);
 545         return 1;
 546 }
 547
 548 __setup("decay=", decay);
 549
 550 /*
 551  * Initialize the logical CPU number to SAPICID mapping
 552  */
 553 void __init
 554 smp_build_cpu_map (void)
 555 {
 556         int sapicid, cpu, i;
 557         int boot_cpu_id = hard_smp_processor_id();
 558
 559         for (cpu = 0; cpu < NR_CPUS; cpu++) {
 560                 ia64_cpu_to_sapicid[cpu] = -1;
 561         }
 562
 563         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 564         cpus_clear(cpu_present_map);
 565         cpu_set(0, cpu_present_map);
 566         cpu_set(0, cpu_possible_map);
 567         for (cpu = 1, i = 0; i < smp_boot_data.cpu_count; i++) {
 568                 sapicid = smp_boot_data.cpu_phys_id[i];
 569                 if (sapicid == boot_cpu_id)
 570                         continue;
 571                 cpu_set(cpu, cpu_present_map);
 572                 cpu_set(cpu, cpu_possible_map);
 573                 ia64_cpu_to_sapicid[cpu] = sapicid;
 574                 cpu++;
 575         }
 576 }
 577
 578 /*
 579  * Cycle through the APs sending Wakeup IPIs to boot each.
 580  */
 581 void __init
 582 smp_prepare_cpus (unsigned int max_cpus)
 583 {
 584         int boot_cpu_id = hard_smp_processor_id();
 585
 586         /*
 587          * Initialize the per-CPU profiling counter/multiplier
 588          */
 589
 590         smp_setup_percpu_timer();
 591
 592         /*
 593          * We have the boot CPU online for sure.
 594          */
 595         cpu_set(0, cpu_online_map);
 596         cpu_set(0, cpu_callin_map);
 597
 598         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 599         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 600
 601         printk(KERN_INFO "Boot processor id 0x%x/0x%x\n", 0, boot_cpu_id);
 602
 603         current_thread_info()->cpu = 0;
 604
 605         /*
 606          * If SMP should be disabled, then really disable it!
 607          */
 608         if (!max_cpus) {
 609                 printk(KERN_INFO "SMP mode deactivated.\n");
 610                 cpus_clear(cpu_online_map);
 611                 cpus_clear(cpu_present_map);
 612                 cpus_clear(cpu_possible_map);
 613                 cpu_set(0, cpu_online_map);
 614                 cpu_set(0, cpu_present_map);
 615                 cpu_set(0, cpu_possible_map);
 616                 return;
 617         }
 618 }
 619
 620 void __devinit smp_prepare_boot_cpu(void)
 621 {
 622         cpu_set(smp_processor_id(), cpu_online_map);
 623         cpu_set(smp_processor_id(), cpu_callin_map);
 624         per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
 625 }
 626
 627 /*
 628  * mt_info[] is a temporary store for all info returned by
 629  * PAL_LOGICAL_TO_PHYSICAL, to be copied into cpuinfo_ia64 when the
 630  * specific cpu comes.
 631  */
 632 static struct {
 633         __u32   socket_id;
 634         __u16   core_id;
 635         __u16   thread_id;
 636         __u16   proc_fixed_addr;
 637         __u8    valid;
 638 } mt_info[NR_CPUS] __devinitdata;
 639
 640 #ifdef CONFIG_HOTPLUG_CPU
 641 static inline void
 642 remove_from_mtinfo(int cpu)
 643 {
 644         int i;
 645
 646         for_each_cpu(i)
 647                 if (mt_info[i].valid &&  mt_info[i].socket_id ==
 648                                                 cpu_data(cpu)->socket_id)
 649                         mt_info[i].valid = 0;
 650 }
 651
 652 static inline void
 653 clear_cpu_sibling_map(int cpu)
 654 {
 655         int i;
 656
 657         for_each_cpu_mask(i, cpu_sibling_map[cpu])
 658                 cpu_clear(cpu, cpu_sibling_map[i]);
 659         for_each_cpu_mask(i, cpu_core_map[cpu])
 660                 cpu_clear(cpu, cpu_core_map[i]);
 661
 662         cpu_sibling_map[cpu] = cpu_core_map[cpu] = CPU_MASK_NONE;
 663 }
 664
 665 static void
 666 remove_siblinginfo(int cpu)
 667 {
 668         int last = 0;
 669
 670         if (cpu_data(cpu)->threads_per_core == 1 &&
 671             cpu_data(cpu)->cores_per_socket == 1) {
 672                 cpu_clear(cpu, cpu_core_map[cpu]);
 673                 cpu_clear(cpu, cpu_sibling_map[cpu]);
 674                 return;
 675         }
 676
 677         last = (cpus_weight(cpu_core_map[cpu]) == 1 ? 1 : 0);
 678
 679         /* remove it from all sibling map's */
 680         clear_cpu_sibling_map(cpu);
 681
 682         /* if this cpu is the last in the core group, remove all its info
 683          * from mt_info structure
 684          */
 685         if (last)
 686                 remove_from_mtinfo(cpu);
 687 }
 688
 689 extern void fixup_irqs(void);
 690
 691 int migrate_platform_irqs(unsigned int cpu)
 692 {
 693         int new_cpei_cpu;
 694         irq_desc_t *desc = NULL;
 695         cpumask_t       mask;
 696         int             retval = 0;
 697
 698         /*
 699          * dont permit CPEI target to removed.
 700          */
 701         if (cpe_vector > 0 && is_cpu_cpei_target(cpu)) {
 702                 printk ("CPU (%d) is CPEI Target\n", cpu);
 703                 if (can_cpei_retarget()) {
 704                         /*
 705                          * Now re-target the CPEI to a different processor
 706                          */
 707                         new_cpei_cpu = any_online_cpu(cpu_online_map);
 708                         mask = cpumask_of_cpu(new_cpei_cpu);
 709                         set_cpei_target_cpu(new_cpei_cpu);
 710                         desc = irq_descp(ia64_cpe_irq);
 711                         /*
 712                          * Switch for now, immediatly, we need to do fake intr
 713                          * as other interrupts, but need to study CPEI behaviour with
 714                          * polling before making changes.
 715                          */
 716                         if (desc) {
 717                                 desc->handler->disable(ia64_cpe_irq);
 718                                 desc->handler->set_affinity(ia64_cpe_irq, mask);
 719                                 desc->handler->enable(ia64_cpe_irq);
 720                                 printk ("Re-targetting CPEI to cpu %d\n", new_cpei_cpu);
 721                         }
 722                 }
 723                 if (!desc) {
 724                         printk ("Unable to retarget CPEI, offline cpu [%d] failed\n", cpu);
 725                         retval = -EBUSY;
 726                 }
 727         }
 728         return retval;
 729 }
 730
 731 /* must be called with cpucontrol mutex held */
 732 int __cpu_disable(void)
 733 {
 734         int cpu = smp_processor_id();
 735
 736         /*
 737          * dont permit boot processor for now
 738          */
 739         if (cpu == 0 && !bsp_remove_ok) {
 740                 printk ("Your platform does not support removal of BSP\n");
 741                 return (-EBUSY);
 742         }
 743
 744         cpu_clear(cpu, cpu_online_map);
 745
 746         if (migrate_platform_irqs(cpu)) {
 747                 cpu_set(cpu, cpu_online_map);
 748                 return (-EBUSY);
 749         }
 750
 751         remove_siblinginfo(cpu);
 752         cpu_clear(cpu, cpu_online_map);
 753         fixup_irqs();
 754         local_flush_tlb_all();
 755         cpu_clear(cpu, cpu_callin_map);
 756         return 0;
 757 }
 758
 759 void __cpu_die(unsigned int cpu)
 760 {
 761         unsigned int i;
 762
 763         for (i = 0; i < 100; i++) {
 764                 /* They ack this in play_dead by setting CPU_DEAD */
 765                 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
 766                 {
 767                         printk ("CPU %d is now offline\n", cpu);
 768                         return;
 769                 }
 770                 msleep(100);
 771         }
 772         printk(KERN_ERR "CPU %u didn't die...\n", cpu);
 773 }
 774 #else /* !CONFIG_HOTPLUG_CPU */
 775 int __cpu_disable(void)
 776 {
 777         return -ENOSYS;
 778 }
 779
 780 void __cpu_die(unsigned int cpu)
 781 {
 782         /* We said "no" in __cpu_disable */
 783         BUG();
 784 }
 785 #endif /* CONFIG_HOTPLUG_CPU */
 786
 787 void
 788 smp_cpus_done (unsigned int dummy)
 789 {
 790         int cpu;
 791         unsigned long bogosum = 0;
 792
 793         /*
 794          * Allow the user to impress friends.
 795          */
 796
 797         for_each_online_cpu(cpu) {
 798                 bogosum += cpu_data(cpu)->loops_per_jiffy;
 799         }
 800
 801         printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
 802                (int)num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100);
 803 }
 804
 805 static inline void __devinit
 806 set_cpu_sibling_map(int cpu)
 807 {
 808         int i;
 809
 810         for_each_online_cpu(i) {
 811                 if ((cpu_data(cpu)->socket_id == cpu_data(i)->socket_id)) {
 812                         cpu_set(i, cpu_core_map[cpu]);
 813                         cpu_set(cpu, cpu_core_map[i]);
 814                         if (cpu_data(cpu)->core_id == cpu_data(i)->core_id) {
 815                                 cpu_set(i, cpu_sibling_map[cpu]);
 816                                 cpu_set(cpu, cpu_sibling_map[i]);
 817                         }
 818                 }
 819         }
 820 }
 821
 822 int __devinit
 823 __cpu_up (unsigned int cpu)
 824 {
 825         int ret;
 826         int sapicid;
 827
 828         sapicid = ia64_cpu_to_sapicid[cpu];
 829         if (sapicid == -1)
 830                 return -EINVAL;
 831
 832         /*
 833          * Already booted cpu? not valid anymore since we dont
 834          * do idle loop tightspin anymore.
 835          */
 836         if (cpu_isset(cpu, cpu_callin_map))
 837                 return -EINVAL;
 838
 839         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 840         /* Processor goes to start_secondary(), sets online flag */
 841         ret = do_boot_cpu(sapicid, cpu);
 842         if (ret < 0)
 843                 return ret;
 844
 845         if (cpu_data(cpu)->threads_per_core == 1 &&
 846             cpu_data(cpu)->cores_per_socket == 1) {
 847                 cpu_set(cpu, cpu_sibling_map[cpu]);
 848                 cpu_set(cpu, cpu_core_map[cpu]);
 849                 return 0;
 850         }
 851
 852         set_cpu_sibling_map(cpu);
 853
 854         return 0;
 855 }
 856
 857 /*
 858  * Assume that CPU's have been discovered by some platform-dependent interface.  For
 859  * SoftSDV/Lion, that would be ACPI.
 860  *
 861  * Setup of the IPI irq handler is done in irq.c:init_IRQ_SMP().
 862  */
 863 void __init
 864 init_smp_config(void)
 865 {
 866         struct fptr {
 867                 unsigned long fp;
 868                 unsigned long gp;
 869         } *ap_startup;
 870         long sal_ret;
 871
 872         /* Tell SAL where to drop the AP's.  */
 873         ap_startup = (struct fptr *) start_ap;
 874         sal_ret = ia64_sal_set_vectors(SAL_VECTOR_OS_BOOT_RENDEZ,
 875                                        ia64_tpa(ap_startup->fp), ia64_tpa(ap_startup->gp), 0, 0, 0, 0);
 876         if (sal_ret < 0)
 877                 printk(KERN_ERR "SMP: Can't set SAL AP Boot Rendezvous: %s\n",
 878                        ia64_sal_strerror(sal_ret));
 879 }
 880
 881 static inline int __devinit
 882 check_for_mtinfo_index(void)
 883 {
 884         int i;
 885
 886         for_each_cpu(i)
 887                 if (!mt_info[i].valid)
 888                         return i;
 889
 890         return -1;
 891 }
 892
 893 /*
 894  * Search the mt_info to find out if this socket's cid/tid information is
 895  * cached or not. If the socket exists, fill in the core_id and thread_id
 896  * in cpuinfo
 897  */
 898 static int __devinit
 899 check_for_new_socket(__u16 logical_address, struct cpuinfo_ia64 *c)
 900 {
 901         int i;
 902         __u32 sid = c->socket_id;
 903
 904         for_each_cpu(i) {
 905                 if (mt_info[i].valid && mt_info[i].proc_fixed_addr == logical_address
 906                     && mt_info[i].socket_id == sid) {
 907                         c->core_id = mt_info[i].core_id;
 908                         c->thread_id = mt_info[i].thread_id;
 909                         return 1; /* not a new socket */
 910                 }
 911         }
 912         return 0;
 913 }
 914
 915 /*
 916  * identify_siblings(cpu) gets called from identify_cpu. This populates the
 917  * information related to logical execution units in per_cpu_data structure.
 918  */
 919 void __devinit
 920 identify_siblings(struct cpuinfo_ia64 *c)
 921 {
 922         s64 status;
 923         u16 pltid;
 924         u64 proc_fixed_addr;
 925         int count, i;
 926         pal_logical_to_physical_t info;
 927
 928         if (smp_num_cpucores == 1 && smp_num_siblings == 1)
 929                 return;
 930
 931         if ((status = ia64_pal_logical_to_phys(0, &info)) != PAL_STATUS_SUCCESS) {
 932                 printk(KERN_ERR "ia64_pal_logical_to_phys failed with %ld\n",
 933                        status);
 934                 return;
 935         }
 936         if ((status = ia64_sal_physical_id_info(&pltid)) != PAL_STATUS_SUCCESS) {
 937                 printk(KERN_ERR "ia64_sal_pltid failed with %ld\n", status);
 938                 return;
 939         }
 940         if ((status = ia64_pal_fixed_addr(&proc_fixed_addr)) != PAL_STATUS_SUCCESS) {
 941                 printk(KERN_ERR "ia64_pal_fixed_addr failed with %ld\n", status);
 942                 return;
 943         }
 944
 945         c->socket_id =  (pltid << 8) | info.overview_ppid;
 946         c->cores_per_socket = info.overview_cpp;
 947         c->threads_per_core = info.overview_tpc;
 948         count = c->num_log = info.overview_num_log;
 949
 950         /* If the thread and core id information is already cached, then
 951          * we will simply update cpu_info and return. Otherwise, we will
 952          * do the PAL calls and cache core and thread id's of all the siblings.
 953          */
 954         if (check_for_new_socket(proc_fixed_addr, c))
 955                 return;
 956
 957         for (i = 0; i < count; i++) {
 958                 int index;
 959
 960                 if (i && (status = ia64_pal_logical_to_phys(i, &info))
 961                           != PAL_STATUS_SUCCESS) {
 962                         printk(KERN_ERR "ia64_pal_logical_to_phys failed"
 963                                         " with %ld\n", status);
 964                         return;
 965                 }
 966                 if (info.log2_la == proc_fixed_addr) {
 967                         c->core_id = info.log1_cid;
 968                         c->thread_id = info.log1_tid;
 969                 }
 970
 971                 index = check_for_mtinfo_index();
 972                 /* We will not do the mt_info caching optimization in this case.
 973                  */
 974                 if (index < 0)
 975                         continue;
 976
 977                 mt_info[index].valid = 1;
 978                 mt_info[index].socket_id = c->socket_id;
 979                 mt_info[index].core_id = info.log1_cid;
 980                 mt_info[index].thread_id = info.log1_tid;
 981                 mt_info[index].proc_fixed_addr = info.log2_la;
 982         }
 983 }