arch/ia64/kernel/smpboot.c

   1 /*
   2  * SMP boot-related support
   3  *
   4  * Copyright (C) 1998-2003, 2005 Hewlett-Packard Co
   5  *      David Mosberger-Tang <davidm@hpl.hp.com>
   6  * Copyright (C) 2001, 2004-2005 Intel Corp
   7  *      Rohit Seth <rohit.seth@intel.com>
   8  *      Suresh Siddha <suresh.b.siddha@intel.com>
   9  *      Gordon Jin <gordon.jin@intel.com>
  10  *      Ashok Raj  <ashok.raj@intel.com>
  11  *
  12  * 01/05/16 Rohit Seth <rohit.seth@intel.com>   Moved SMP booting functions from smp.c to here.
  13  * 01/04/27 David Mosberger <davidm@hpl.hp.com> Added ITC synching code.
  14  * 02/07/31 David Mosberger <davidm@hpl.hp.com> Switch over to hotplug-CPU boot-sequence.
  15  *                                              smp_boot_cpus()/smp_commence() is replaced by
  16  *                                              smp_prepare_cpus()/__cpu_up()/smp_cpus_done().
  17  * 04/06/21 Ashok Raj           <ashok.raj@intel.com> Added CPU Hotplug Support
  18  * 04/12/26 Jin Gordon <gordon.jin@intel.com>
  19  * 04/12/26 Rohit Seth <rohit.seth@intel.com>
  20  *                                              Add multi-threading and multi-core detection
  21  * 05/01/30 Suresh Siddha <suresh.b.siddha@intel.com>
  22  *                                              Setup cpu_sibling_map and cpu_core_map
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/acpi.h>
  27 #include <linux/bootmem.h>
  28 #include <linux/cpu.h>
  29 #include <linux/delay.h>
  30 #include <linux/init.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/irq.h>
  33 #include <linux/kernel.h>
  34 #include <linux/kernel_stat.h>
  35 #include <linux/mm.h>
  36 #include <linux/notifier.h>
  37 #include <linux/smp.h>
  38 #include <linux/spinlock.h>
  39 #include <linux/efi.h>
  40 #include <linux/percpu.h>
  41 #include <linux/bitops.h>
  42
  43 #include <asm/atomic.h>
  44 #include <asm/cache.h>
  45 #include <asm/current.h>
  46 #include <asm/delay.h>
  47 #include <asm/ia32.h>
  48 #include <asm/io.h>
  49 #include <asm/irq.h>
  50 #include <asm/machvec.h>
  51 #include <asm/mca.h>
  52 #include <asm/page.h>
  53 #include <asm/pgalloc.h>
  54 #include <asm/pgtable.h>
  55 #include <asm/processor.h>
  56 #include <asm/ptrace.h>
  57 #include <asm/sal.h>
  58 #include <asm/system.h>
  59 #include <asm/tlbflush.h>
  60 #include <asm/unistd.h>
  61
  62 #define SMP_DEBUG 0
  63
  64 #if SMP_DEBUG
  65 #define Dprintk(x...)  printk(x)
  66 #else
  67 #define Dprintk(x...)
  68 #endif
  69
  70 #ifdef CONFIG_HOTPLUG_CPU
  71 #ifdef CONFIG_PERMIT_BSP_REMOVE
  72 #define bsp_remove_ok   1
  73 #else
  74 #define bsp_remove_ok   0
  75 #endif
  76
  77 /*
  78  * Store all idle threads, this can be reused instead of creating
  79  * a new thread. Also avoids complicated thread destroy functionality
  80  * for idle threads.
  81  */
  82 struct task_struct *idle_thread_array[NR_CPUS];
  83
  84 /*
  85  * Global array allocated for NR_CPUS at boot time
  86  */
  87 struct sal_to_os_boot sal_boot_rendez_state[NR_CPUS];
  88
  89 /*
  90  * start_ap in head.S uses this to store current booting cpu
  91  * info.
  92  */
  93 struct sal_to_os_boot *sal_state_for_booting_cpu = &sal_boot_rendez_state[0];
  94
  95 #define set_brendez_area(x) (sal_state_for_booting_cpu = &sal_boot_rendez_state[(x)]);
  96
  97 #define get_idle_for_cpu(x)             (idle_thread_array[(x)])
  98 #define set_idle_for_cpu(x,p)   (idle_thread_array[(x)] = (p))
  99
 100 #else
 101
 102 #define get_idle_for_cpu(x)             (NULL)
 103 #define set_idle_for_cpu(x,p)
 104 #define set_brendez_area(x)
 105 #endif
 106
 107
 108 /*
 109  * ITC synchronization related stuff:
 110  */
 111 #define MASTER  (0)
 112 #define SLAVE   (SMP_CACHE_BYTES/8)
 113
 114 #define NUM_ROUNDS      64      /* magic value */
 115 #define NUM_ITERS       5       /* likewise */
 116
 117 static DEFINE_SPINLOCK(itc_sync_lock);
 118 static volatile unsigned long go[SLAVE + 1];
 119
 120 #define DEBUG_ITC_SYNC  0
 121
 122 extern void __devinit calibrate_delay (void);
 123 extern void start_ap (void);
 124 extern unsigned long ia64_iobase;
 125
 126 struct task_struct *task_for_booting_cpu;
 127
 128 /*
 129  * State for each CPU
 130  */
 131 DEFINE_PER_CPU(int, cpu_state);
 132
 133 /* Bitmasks of currently online, and possible CPUs */
 134 cpumask_t cpu_online_map;
 135 EXPORT_SYMBOL(cpu_online_map);
 136 cpumask_t cpu_possible_map = CPU_MASK_NONE;
 137 EXPORT_SYMBOL(cpu_possible_map);
 138
 139 cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
 140 cpumask_t cpu_sibling_map[NR_CPUS] __cacheline_aligned;
 141 int smp_num_siblings = 1;
 142 int smp_num_cpucores = 1;
 143
 144 /* which logical CPU number maps to which CPU (physical APIC ID) */
 145 volatile int ia64_cpu_to_sapicid[NR_CPUS];
 146 EXPORT_SYMBOL(ia64_cpu_to_sapicid);
 147
 148 static volatile cpumask_t cpu_callin_map;
 149
 150 struct smp_boot_data smp_boot_data __initdata;
 151
 152 unsigned long ap_wakeup_vector = -1; /* External Int use to wakeup APs */
 153
 154 char __initdata no_int_routing;
 155
 156 unsigned char smp_int_redirect; /* are INT and IPI redirectable by the chipset? */
 157
 158 #ifdef CONFIG_FORCE_CPEI_RETARGET
 159 #define CPEI_OVERRIDE_DEFAULT   (1)
 160 #else
 161 #define CPEI_OVERRIDE_DEFAULT   (0)
 162 #endif
 163
 164 unsigned int force_cpei_retarget = CPEI_OVERRIDE_DEFAULT;
 165
 166 static int __init
 167 cmdl_force_cpei(char *str)
 168 {
 169         int value=0;
 170
 171         get_option (&str, &value);
 172         force_cpei_retarget = value;
 173
 174         return 1;
 175 }
 176
 177 __setup("force_cpei=", cmdl_force_cpei);
 178
 179 static int __init
 180 nointroute (char *str)
 181 {
 182         no_int_routing = 1;
 183         printk ("no_int_routing on\n");
 184         return 1;
 185 }
 186
 187 __setup("nointroute", nointroute);
 188
 189 static void fix_b0_for_bsp(void)
 190 {
 191 #ifdef CONFIG_HOTPLUG_CPU
 192         int cpuid;
 193         static int fix_bsp_b0 = 1;
 194
 195         cpuid = smp_processor_id();
 196
 197         /*
 198          * Cache the b0 value on the first AP that comes up
 199          */
 200         if (!(fix_bsp_b0 && cpuid))
 201                 return;
 202
 203         sal_boot_rendez_state[0].br[0] = sal_boot_rendez_state[cpuid].br[0];
 204         printk ("Fixed BSP b0 value from CPU %d\n", cpuid);
 205
 206         fix_bsp_b0 = 0;
 207 #endif
 208 }
 209
 210 void
 211 sync_master (void *arg)
 212 {
 213         unsigned long flags, i;
 214
 215         go[MASTER] = 0;
 216
 217         local_irq_save(flags);
 218         {
 219                 for (i = 0; i < NUM_ROUNDS*NUM_ITERS; ++i) {
 220                         while (!go[MASTER])
 221                                 cpu_relax();
 222                         go[MASTER] = 0;
 223                         go[SLAVE] = ia64_get_itc();
 224                 }
 225         }
 226         local_irq_restore(flags);
 227 }
 228
 229 /*
 230  * Return the number of cycles by which our itc differs from the itc on the master
 231  * (time-keeper) CPU.  A positive number indicates our itc is ahead of the master,
 232  * negative that it is behind.
 233  */
 234 static inline long
 235 get_delta (long *rt, long *master)
 236 {
 237         unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0;
 238         unsigned long tcenter, t0, t1, tm;
 239         long i;
 240
 241         for (i = 0; i < NUM_ITERS; ++i) {
 242                 t0 = ia64_get_itc();
 243                 go[MASTER] = 1;
 244                 while (!(tm = go[SLAVE]))
 245                         cpu_relax();
 246                 go[SLAVE] = 0;
 247                 t1 = ia64_get_itc();
 248
 249                 if (t1 - t0 < best_t1 - best_t0)
 250                         best_t0 = t0, best_t1 = t1, best_tm = tm;
 251         }
 252
 253         *rt = best_t1 - best_t0;
 254         *master = best_tm - best_t0;
 255
 256         /* average best_t0 and best_t1 without overflow: */
 257         tcenter = (best_t0/2 + best_t1/2);
 258         if (best_t0 % 2 + best_t1 % 2 == 2)
 259                 ++tcenter;
 260         return tcenter - best_tm;
 261 }
 262
 263 /*
 264  * Synchronize ar.itc of the current (slave) CPU with the ar.itc of the MASTER CPU
 265  * (normally the time-keeper CPU).  We use a closed loop to eliminate the possibility of
 266  * unaccounted-for errors (such as getting a machine check in the middle of a calibration
 267  * step).  The basic idea is for the slave to ask the master what itc value it has and to
 268  * read its own itc before and after the master responds.  Each iteration gives us three
 269  * timestamps:
 270  *
 271  *      slave           master
 272  *
 273  *      t0 ---\
 274  *             ---\
 275  *                 --->
 276  *                      tm
 277  *                 /---
 278  *             /---
 279  *      t1 <---
 280  *
 281  *
 282  * The goal is to adjust the slave's ar.itc such that tm falls exactly half-way between t0
 283  * and t1.  If we achieve this, the clocks are synchronized provided the interconnect
 284  * between the slave and the master is symmetric.  Even if the interconnect were
 285  * asymmetric, we would still know that the synchronization error is smaller than the
 286  * roundtrip latency (t0 - t1).
 287  *
 288  * When the interconnect is quiet and symmetric, this lets us synchronize the itc to
 289  * within one or two cycles.  However, we can only *guarantee* that the synchronization is
 290  * accurate to within a round-trip time, which is typically in the range of several
 291  * hundred cycles (e.g., ~500 cycles).  In practice, this means that the itc's are usually
 292  * almost perfectly synchronized, but we shouldn't assume that the accuracy is much better
 293  * than half a micro second or so.
 294  */
 295 void
 296 ia64_sync_itc (unsigned int master)
 297 {
 298         long i, delta, adj, adjust_latency = 0, done = 0;
 299         unsigned long flags, rt, master_time_stamp, bound;
 300 #if DEBUG_ITC_SYNC
 301         struct {
 302                 long rt;        /* roundtrip time */
 303                 long master;    /* master's timestamp */
 304                 long diff;      /* difference between midpoint and master's timestamp */
 305                 long lat;       /* estimate of itc adjustment latency */
 306         } t[NUM_ROUNDS];
 307 #endif
 308
 309         /*
 310          * Make sure local timer ticks are disabled while we sync.  If
 311          * they were enabled, we'd have to worry about nasty issues
 312          * like setting the ITC ahead of (or a long time before) the
 313          * next scheduled tick.
 314          */
 315         BUG_ON((ia64_get_itv() & (1 << 16)) == 0);
 316
 317         go[MASTER] = 1;
 318
 319         if (smp_call_function_single(master, sync_master, NULL, 1, 0) < 0) {
 320                 printk(KERN_ERR "sync_itc: failed to get attention of CPU %u!\n", master);
 321                 return;
 322         }
 323
 324         while (go[MASTER])
 325                 cpu_relax();    /* wait for master to be ready */
 326
 327         spin_lock_irqsave(&itc_sync_lock, flags);
 328         {
 329                 for (i = 0; i < NUM_ROUNDS; ++i) {
 330                         delta = get_delta(&rt, &master_time_stamp);
 331                         if (delta == 0) {
 332                                 done = 1;       /* let's lock on to this... */
 333                                 bound = rt;
 334                         }
 335
 336                         if (!done) {
 337                                 if (i > 0) {
 338                                         adjust_latency += -delta;
 339                                         adj = -delta + adjust_latency/4;
 340                                 } else
 341                                         adj = -delta;
 342
 343                                 ia64_set_itc(ia64_get_itc() + adj);
 344                         }
 345 #if DEBUG_ITC_SYNC
 346                         t[i].rt = rt;
 347                         t[i].master = master_time_stamp;
 348                         t[i].diff = delta;
 349                         t[i].lat = adjust_latency/4;
 350 #endif
 351                 }
 352         }
 353         spin_unlock_irqrestore(&itc_sync_lock, flags);
 354
 355 #if DEBUG_ITC_SYNC
 356         for (i = 0; i < NUM_ROUNDS; ++i)
 357                 printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n",
 358                        t[i].rt, t[i].master, t[i].diff, t[i].lat);
 359 #endif
 360
 361         printk(KERN_INFO "CPU %d: synchronized ITC with CPU %u (last diff %ld cycles, "
 362                "maxerr %lu cycles)\n", smp_processor_id(), master, delta, rt);
 363 }
 364
 365 /*
 366  * Ideally sets up per-cpu profiling hooks.  Doesn't do much now...
 367  */
 368 static inline void __devinit
 369 smp_setup_percpu_timer (void)
 370 {
 371 }
 372
 373 static void __devinit
 374 smp_callin (void)
 375 {
 376         int cpuid, phys_id, itc_master;
 377         struct cpuinfo_ia64 *last_cpuinfo, *this_cpuinfo;
 378         extern void ia64_init_itm(void);
 379         extern volatile int time_keeper_id;
 380
 381 #ifdef CONFIG_PERFMON
 382         extern void pfm_init_percpu(void);
 383 #endif
 384
 385         cpuid = smp_processor_id();
 386         phys_id = hard_smp_processor_id();
 387         itc_master = time_keeper_id;
 388
 389         if (cpu_online(cpuid)) {
 390                 printk(KERN_ERR "huh, phys CPU#0x%x, CPU#0x%x already present??\n",
 391                        phys_id, cpuid);
 392                 BUG();
 393         }
 394
 395         fix_b0_for_bsp();
 396
 397         lock_ipi_calllock();
 398         cpu_set(cpuid, cpu_online_map);
 399         unlock_ipi_calllock();
 400         per_cpu(cpu_state, cpuid) = CPU_ONLINE;
 401
 402         smp_setup_percpu_timer();
 403
 404         ia64_mca_cmc_vector_setup();    /* Setup vector on AP */
 405
 406 #ifdef CONFIG_PERFMON
 407         pfm_init_percpu();
 408 #endif
 409
 410         local_irq_enable();
 411
 412         if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
 413                 /*
 414                  * Synchronize the ITC with the BP.  Need to do this after irqs are
 415                  * enabled because ia64_sync_itc() calls smp_call_function_single(), which
 416                  * calls spin_unlock_bh(), which calls spin_unlock_bh(), which calls
 417                  * local_bh_enable(), which bugs out if irqs are not enabled...
 418                  */
 419                 Dprintk("Going to syncup ITC with ITC Master.\n");
 420                 ia64_sync_itc(itc_master);
 421         }
 422
 423         /*
 424          * Get our bogomips.
 425          */
 426         ia64_init_itm();
 427
 428         /*
 429          * Delay calibration can be skipped if new processor is identical to the
 430          * previous processor.
 431          */
 432         last_cpuinfo = cpu_data(cpuid - 1);
 433         this_cpuinfo = local_cpu_data;
 434         if (last_cpuinfo->itc_freq != this_cpuinfo->itc_freq ||
 435             last_cpuinfo->proc_freq != this_cpuinfo->proc_freq ||
 436             last_cpuinfo->features != this_cpuinfo->features ||
 437             last_cpuinfo->revision != this_cpuinfo->revision ||
 438             last_cpuinfo->family != this_cpuinfo->family ||
 439             last_cpuinfo->archrev != this_cpuinfo->archrev ||
 440             last_cpuinfo->model != this_cpuinfo->model)
 441                 calibrate_delay();
 442         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 443
 444 #ifdef CONFIG_IA32_SUPPORT
 445         ia32_gdt_init();
 446 #endif
 447
 448         /*
 449          * Allow the master to continue.
 450          */
 451         cpu_set(cpuid, cpu_callin_map);
 452         Dprintk("Stack on CPU %d at about %p\n",cpuid, &cpuid);
 453 }
 454
 455
 456 /*
 457  * Activate a secondary processor.  head.S calls this.
 458  */
 459 int __devinit
 460 start_secondary (void *unused)
 461 {
 462         /* Early console may use I/O ports */
 463         ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
 464         Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id());
 465         efi_map_pal_code();
 466         cpu_init();
 467         preempt_disable();
 468         smp_callin();
 469
 470         cpu_idle();
 471         return 0;
 472 }
 473
 474 struct pt_regs * __devinit idle_regs(struct pt_regs *regs)
 475 {
 476         return NULL;
 477 }
 478
 479 struct create_idle {
 480         struct work_struct work;
 481         struct task_struct *idle;
 482         struct completion done;
 483         int cpu;
 484 };
 485
 486 void
 487 do_fork_idle(struct work_struct *work)
 488 {
 489         struct create_idle *c_idle =
 490                 container_of(work, struct create_idle, work);
 491
 492         c_idle->idle = fork_idle(c_idle->cpu);
 493         complete(&c_idle->done);
 494 }
 495
 496 static int __devinit
 497 do_boot_cpu (int sapicid, int cpu)
 498 {
 499         int timeout;
 500         struct create_idle c_idle = {
 501                 .work = __WORK_INITIALIZER(c_idle.work, do_fork_idle),
 502                 .cpu    = cpu,
 503                 .done   = COMPLETION_INITIALIZER(c_idle.done),
 504         };
 505
 506         c_idle.idle = get_idle_for_cpu(cpu);
 507         if (c_idle.idle) {
 508                 init_idle(c_idle.idle, cpu);
 509                 goto do_rest;
 510         }
 511
 512         /*
 513          * We can't use kernel_thread since we must avoid to reschedule the child.
 514          */
 515         if (!keventd_up() || current_is_keventd())
 516                 c_idle.work.func(&c_idle.work);
 517         else {
 518                 schedule_work(&c_idle.work);
 519                 wait_for_completion(&c_idle.done);
 520         }
 521
 522         if (IS_ERR(c_idle.idle))
 523                 panic("failed fork for CPU %d", cpu);
 524
 525         set_idle_for_cpu(cpu, c_idle.idle);
 526
 527 do_rest:
 528         task_for_booting_cpu = c_idle.idle;
 529
 530         Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
 531
 532         set_brendez_area(cpu);
 533         platform_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0);
 534
 535         /*
 536          * Wait 10s total for the AP to start
 537          */
 538         Dprintk("Waiting on callin_map ...");
 539         for (timeout = 0; timeout < 100000; timeout++) {
 540                 if (cpu_isset(cpu, cpu_callin_map))
 541                         break;  /* It has booted */
 542                 udelay(100);
 543         }
 544         Dprintk("\n");
 545
 546         if (!cpu_isset(cpu, cpu_callin_map)) {
 547                 printk(KERN_ERR "Processor 0x%x/0x%x is stuck.\n", cpu, sapicid);
 548                 ia64_cpu_to_sapicid[cpu] = -1;
 549                 cpu_clear(cpu, cpu_online_map);  /* was set in smp_callin() */
 550                 return -EINVAL;
 551         }
 552         return 0;
 553 }
 554
 555 static int __init
 556 decay (char *str)
 557 {
 558         int ticks;
 559         get_option (&str, &ticks);
 560         return 1;
 561 }
 562
 563 __setup("decay=", decay);
 564
 565 /*
 566  * Initialize the logical CPU number to SAPICID mapping
 567  */
 568 void __init
 569 smp_build_cpu_map (void)
 570 {
 571         int sapicid, cpu, i;
 572         int boot_cpu_id = hard_smp_processor_id();
 573
 574         for (cpu = 0; cpu < NR_CPUS; cpu++) {
 575                 ia64_cpu_to_sapicid[cpu] = -1;
 576         }
 577
 578         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 579         cpus_clear(cpu_present_map);
 580         cpu_set(0, cpu_present_map);
 581         cpu_set(0, cpu_possible_map);
 582         for (cpu = 1, i = 0; i < smp_boot_data.cpu_count; i++) {
 583                 sapicid = smp_boot_data.cpu_phys_id[i];
 584                 if (sapicid == boot_cpu_id)
 585                         continue;
 586                 cpu_set(cpu, cpu_present_map);
 587                 cpu_set(cpu, cpu_possible_map);
 588                 ia64_cpu_to_sapicid[cpu] = sapicid;
 589                 cpu++;
 590         }
 591 }
 592
 593 /*
 594  * Cycle through the APs sending Wakeup IPIs to boot each.
 595  */
 596 void __init
 597 smp_prepare_cpus (unsigned int max_cpus)
 598 {
 599         int boot_cpu_id = hard_smp_processor_id();
 600
 601         /*
 602          * Initialize the per-CPU profiling counter/multiplier
 603          */
 604
 605         smp_setup_percpu_timer();
 606
 607         /*
 608          * We have the boot CPU online for sure.
 609          */
 610         cpu_set(0, cpu_online_map);
 611         cpu_set(0, cpu_callin_map);
 612
 613         local_cpu_data->loops_per_jiffy = loops_per_jiffy;
 614         ia64_cpu_to_sapicid[0] = boot_cpu_id;
 615
 616         printk(KERN_INFO "Boot processor id 0x%x/0x%x\n", 0, boot_cpu_id);
 617
 618         current_thread_info()->cpu = 0;
 619
 620         /*
 621          * If SMP should be disabled, then really disable it!
 622          */
 623         if (!max_cpus) {
 624                 printk(KERN_INFO "SMP mode deactivated.\n");
 625                 cpus_clear(cpu_online_map);
 626                 cpus_clear(cpu_present_map);
 627                 cpus_clear(cpu_possible_map);
 628                 cpu_set(0, cpu_online_map);
 629                 cpu_set(0, cpu_present_map);
 630                 cpu_set(0, cpu_possible_map);
 631                 return;
 632         }
 633 }
 634
 635 void __devinit smp_prepare_boot_cpu(void)
 636 {
 637         cpu_set(smp_processor_id(), cpu_online_map);
 638         cpu_set(smp_processor_id(), cpu_callin_map);
 639         per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
 640 }
 641
 642 #ifdef CONFIG_HOTPLUG_CPU
 643 static inline void
 644 clear_cpu_sibling_map(int cpu)
 645 {
 646         int i;
 647
 648         for_each_cpu_mask(i, cpu_sibling_map[cpu])
 649                 cpu_clear(cpu, cpu_sibling_map[i]);
 650         for_each_cpu_mask(i, cpu_core_map[cpu])
 651                 cpu_clear(cpu, cpu_core_map[i]);
 652
 653         cpu_sibling_map[cpu] = cpu_core_map[cpu] = CPU_MASK_NONE;
 654 }
 655
 656 static void
 657 remove_siblinginfo(int cpu)
 658 {
 659         int last = 0;
 660
 661         if (cpu_data(cpu)->threads_per_core == 1 &&
 662             cpu_data(cpu)->cores_per_socket == 1) {
 663                 cpu_clear(cpu, cpu_core_map[cpu]);
 664                 cpu_clear(cpu, cpu_sibling_map[cpu]);
 665                 return;
 666         }
 667
 668         last = (cpus_weight(cpu_core_map[cpu]) == 1 ? 1 : 0);
 669
 670         /* remove it from all sibling map's */
 671         clear_cpu_sibling_map(cpu);
 672 }
 673
 674 extern void fixup_irqs(void);
 675
 676 int migrate_platform_irqs(unsigned int cpu)
 677 {
 678         int new_cpei_cpu;
 679         irq_desc_t *desc = NULL;
 680         cpumask_t       mask;
 681         int             retval = 0;
 682
 683         /*
 684          * dont permit CPEI target to removed.
 685          */
 686         if (cpe_vector > 0 && is_cpu_cpei_target(cpu)) {
 687                 printk ("CPU (%d) is CPEI Target\n", cpu);
 688                 if (can_cpei_retarget()) {
 689                         /*
 690                          * Now re-target the CPEI to a different processor
 691                          */
 692                         new_cpei_cpu = any_online_cpu(cpu_online_map);
 693                         mask = cpumask_of_cpu(new_cpei_cpu);
 694                         set_cpei_target_cpu(new_cpei_cpu);
 695                         desc = irq_desc + ia64_cpe_irq;
 696                         /*
 697                          * Switch for now, immediatly, we need to do fake intr
 698                          * as other interrupts, but need to study CPEI behaviour with
 699                          * polling before making changes.
 700                          */
 701                         if (desc) {
 702                                 desc->chip->disable(ia64_cpe_irq);
 703                                 desc->chip->set_affinity(ia64_cpe_irq, mask);
 704                                 desc->chip->enable(ia64_cpe_irq);
 705                                 printk ("Re-targetting CPEI to cpu %d\n", new_cpei_cpu);
 706                         }
 707                 }
 708                 if (!desc) {
 709                         printk ("Unable to retarget CPEI, offline cpu [%d] failed\n", cpu);
 710                         retval = -EBUSY;
 711                 }
 712         }
 713         return retval;
 714 }
 715
 716 /* must be called with cpucontrol mutex held */
 717 int __cpu_disable(void)
 718 {
 719         int cpu = smp_processor_id();
 720
 721         /*
 722          * dont permit boot processor for now
 723          */
 724         if (cpu == 0 && !bsp_remove_ok) {
 725                 printk ("Your platform does not support removal of BSP\n");
 726                 return (-EBUSY);
 727         }
 728
 729         cpu_clear(cpu, cpu_online_map);
 730
 731         if (migrate_platform_irqs(cpu)) {
 732                 cpu_set(cpu, cpu_online_map);
 733                 return (-EBUSY);
 734         }
 735
 736         remove_siblinginfo(cpu);
 737         cpu_clear(cpu, cpu_online_map);
 738         fixup_irqs();
 739         local_flush_tlb_all();
 740         cpu_clear(cpu, cpu_callin_map);
 741         return 0;
 742 }
 743
 744 void __cpu_die(unsigned int cpu)
 745 {
 746         unsigned int i;
 747
 748         for (i = 0; i < 100; i++) {
 749                 /* They ack this in play_dead by setting CPU_DEAD */
 750                 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
 751                 {
 752                         printk ("CPU %d is now offline\n", cpu);
 753                         return;
 754                 }
 755                 msleep(100);
 756         }
 757         printk(KERN_ERR "CPU %u didn't die...\n", cpu);
 758 }
 759 #else /* !CONFIG_HOTPLUG_CPU */
 760 int __cpu_disable(void)
 761 {
 762         return -ENOSYS;
 763 }
 764
 765 void __cpu_die(unsigned int cpu)
 766 {
 767         /* We said "no" in __cpu_disable */
 768         BUG();
 769 }
 770 #endif /* CONFIG_HOTPLUG_CPU */
 771
 772 void
 773 smp_cpus_done (unsigned int dummy)
 774 {
 775         int cpu;
 776         unsigned long bogosum = 0;
 777
 778         /*
 779          * Allow the user to impress friends.
 780          */
 781
 782         for_each_online_cpu(cpu) {
 783                 bogosum += cpu_data(cpu)->loops_per_jiffy;
 784         }
 785
 786         printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
 787                (int)num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100);
 788 }
 789
 790 static inline void __devinit
 791 set_cpu_sibling_map(int cpu)
 792 {
 793         int i;
 794
 795         for_each_online_cpu(i) {
 796                 if ((cpu_data(cpu)->socket_id == cpu_data(i)->socket_id)) {
 797                         cpu_set(i, cpu_core_map[cpu]);
 798                         cpu_set(cpu, cpu_core_map[i]);
 799                         if (cpu_data(cpu)->core_id == cpu_data(i)->core_id) {
 800                                 cpu_set(i, cpu_sibling_map[cpu]);
 801                                 cpu_set(cpu, cpu_sibling_map[i]);
 802                         }
 803                 }
 804         }
 805 }
 806
 807 int __devinit
 808 __cpu_up (unsigned int cpu)
 809 {
 810         int ret;
 811         int sapicid;
 812
 813         sapicid = ia64_cpu_to_sapicid[cpu];
 814         if (sapicid == -1)
 815                 return -EINVAL;
 816
 817         /*
 818          * Already booted cpu? not valid anymore since we dont
 819          * do idle loop tightspin anymore.
 820          */
 821         if (cpu_isset(cpu, cpu_callin_map))
 822                 return -EINVAL;
 823
 824         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 825         /* Processor goes to start_secondary(), sets online flag */
 826         ret = do_boot_cpu(sapicid, cpu);
 827         if (ret < 0)
 828                 return ret;
 829
 830         if (cpu_data(cpu)->threads_per_core == 1 &&
 831             cpu_data(cpu)->cores_per_socket == 1) {
 832                 cpu_set(cpu, cpu_sibling_map[cpu]);
 833                 cpu_set(cpu, cpu_core_map[cpu]);
 834                 return 0;
 835         }
 836
 837         set_cpu_sibling_map(cpu);
 838
 839         return 0;
 840 }
 841
 842 /*
 843  * Assume that CPU's have been discovered by some platform-dependent interface.  For
 844  * SoftSDV/Lion, that would be ACPI.
 845  *
 846  * Setup of the IPI irq handler is done in irq.c:init_IRQ_SMP().
 847  */
 848 void __init
 849 init_smp_config(void)
 850 {
 851         struct fptr {
 852                 unsigned long fp;
 853                 unsigned long gp;
 854         } *ap_startup;
 855         long sal_ret;
 856
 857         /* Tell SAL where to drop the AP's.  */
 858         ap_startup = (struct fptr *) start_ap;
 859         sal_ret = ia64_sal_set_vectors(SAL_VECTOR_OS_BOOT_RENDEZ,
 860                                        ia64_tpa(ap_startup->fp), ia64_tpa(ap_startup->gp), 0, 0, 0, 0);
 861         if (sal_ret < 0)
 862                 printk(KERN_ERR "SMP: Can't set SAL AP Boot Rendezvous: %s\n",
 863                        ia64_sal_strerror(sal_ret));
 864 }
 865
 866 /*
 867  * identify_siblings(cpu) gets called from identify_cpu. This populates the
 868  * information related to logical execution units in per_cpu_data structure.
 869  */
 870 void __devinit
 871 identify_siblings(struct cpuinfo_ia64 *c)
 872 {
 873         s64 status;
 874         u16 pltid;
 875         pal_logical_to_physical_t info;
 876
 877         if (smp_num_cpucores == 1 && smp_num_siblings == 1)
 878                 return;
 879
 880         if ((status = ia64_pal_logical_to_phys(-1, &info)) != PAL_STATUS_SUCCESS) {
 881                 printk(KERN_ERR "ia64_pal_logical_to_phys failed with %ld\n",
 882                        status);
 883                 return;
 884         }
 885         if ((status = ia64_sal_physical_id_info(&pltid)) != PAL_STATUS_SUCCESS) {
 886                 printk(KERN_ERR "ia64_sal_pltid failed with %ld\n", status);
 887                 return;
 888         }
 889
 890         c->socket_id =  (pltid << 8) | info.overview_ppid;
 891         c->cores_per_socket = info.overview_cpp;
 892         c->threads_per_core = info.overview_tpc;
 893         c->num_log = info.overview_num_log;
 894
 895         c->core_id = info.log1_cid;
 896         c->thread_id = info.log1_tid;
 897 }
 898
 899 /*
 900  * returns non zero, if multi-threading is enabled
 901  * on at least one physical package. Due to hotplug cpu
 902  * and (maxcpus=), all threads may not necessarily be enabled
 903  * even though the processor supports multi-threading.
 904  */
 905 int is_multithreading_enabled(void)
 906 {
 907         int i, j;
 908
 909         for_each_present_cpu(i) {
 910                 for_each_present_cpu(j) {
 911                         if (j == i)
 912                                 continue;
 913                         if ((cpu_data(j)->socket_id == cpu_data(i)->socket_id)) {
 914                                 if (cpu_data(j)->core_id == cpu_data(i)->core_id)
 915                                         return 1;
 916                         }
 917                 }
 918         }
 919         return 0;
 920 }
 921 EXPORT_SYMBOL_GPL(is_multithreading_enabled);