Pileus Git - ~andy/linux/blob - arch/s390/kernel/smp.c

   1 /*
   2  *  arch/s390/kernel/smp.c
   3  *
   4  *    Copyright IBM Corp. 1999, 2009
   5  *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
   6  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   7  *               Heiko Carstens (heiko.carstens@de.ibm.com)
   8  *
   9  *  based on other smp stuff by
  10  *    (c) 1995 Alan Cox, CymruNET Ltd  <alan@cymru.net>
  11  *    (c) 1998 Ingo Molnar
  12  *
  13  * We work with logical cpu numbering everywhere we can. The only
  14  * functions using the real cpu address (got from STAP) are the sigp
  15  * functions. For all other functions we use the identity mapping.
  16  * That means that cpu_number_map[i] == i for every cpu. cpu_number_map is
  17  * used e.g. to find the idle task belonging to a logical cpu. Every array
  18  * in the kernel is sorted by the logical cpu number and not by the physical
  19  * one which is causing all the confusion with __cpu_logical_map and
  20  * cpu_number_map in other architectures.
  21  */
  22
  23 #define KMSG_COMPONENT "cpu"
  24 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  25
  26 #include <linux/workqueue.h>
  27 #include <linux/module.h>
  28 #include <linux/init.h>
  29 #include <linux/mm.h>
  30 #include <linux/err.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/kernel_stat.h>
  33 #include <linux/delay.h>
  34 #include <linux/cache.h>
  35 #include <linux/interrupt.h>
  36 #include <linux/irqflags.h>
  37 #include <linux/cpu.h>
  38 #include <linux/timex.h>
  39 #include <linux/bootmem.h>
  40 #include <linux/slab.h>
  41 #include <linux/crash_dump.h>
  42 #include <asm/asm-offsets.h>
  43 #include <asm/ipl.h>
  44 #include <asm/setup.h>
  45 #include <asm/sigp.h>
  46 #include <asm/pgalloc.h>
  47 #include <asm/irq.h>
  48 #include <asm/cpcmd.h>
  49 #include <asm/tlbflush.h>
  50 #include <asm/timer.h>
  51 #include <asm/lowcore.h>
  52 #include <asm/sclp.h>
  53 #include <asm/cputime.h>
  54 #include <asm/vdso.h>
  55 #include <asm/cpu.h>
  56 #include "entry.h"
  57
  58 /* logical cpu to cpu address */
  59 unsigned short __cpu_logical_map[NR_CPUS];
  60
  61 static struct task_struct *current_set[NR_CPUS];
  62
  63 static u8 smp_cpu_type;
  64 static int smp_use_sigp_detection;
  65
  66 enum s390_cpu_state {
  67         CPU_STATE_STANDBY,
  68         CPU_STATE_CONFIGURED,
  69 };
  70
  71 DEFINE_MUTEX(smp_cpu_state_mutex);
  72 static int smp_cpu_state[NR_CPUS];
  73
  74 static DEFINE_PER_CPU(struct cpu, cpu_devices);
  75
  76 static void smp_ext_bitcall(int, int);
  77
  78 static int raw_cpu_stopped(int cpu)
  79 {
  80         u32 status;
  81
  82         switch (raw_sigp_ps(&status, 0, cpu, sigp_sense)) {
  83         case sigp_status_stored:
  84                 /* Check for stopped and check stop state */
  85                 if (status & 0x50)
  86                         return 1;
  87                 break;
  88         default:
  89                 break;
  90         }
  91         return 0;
  92 }
  93
  94 static inline int cpu_stopped(int cpu)
  95 {
  96         return raw_cpu_stopped(cpu_logical_map(cpu));
  97 }
  98
  99 /*
 100  * Ensure that PSW restart is done on an online CPU
 101  */
 102 void smp_restart_with_online_cpu(void)
 103 {
 104         int cpu;
 105
 106         for_each_online_cpu(cpu) {
 107                 if (stap() == __cpu_logical_map[cpu]) {
 108                         /* We are online: Enable DAT again and return */
 109                         __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT);
 110                         return;
 111                 }
 112         }
 113         /* We are not online: Do PSW restart on an online CPU */
 114         while (sigp(cpu, sigp_restart) == sigp_busy)
 115                 cpu_relax();
 116         /* And stop ourself */
 117         while (raw_sigp(stap(), sigp_stop) == sigp_busy)
 118                 cpu_relax();
 119         for (;;);
 120 }
 121
 122 void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
 123 {
 124         struct _lowcore *lc, *current_lc;
 125         struct stack_frame *sf;
 126         struct pt_regs *regs;
 127         unsigned long sp;
 128
 129         if (smp_processor_id() == 0)
 130                 func(data);
 131         __load_psw_mask(PSW_DEFAULT_KEY | PSW_MASK_BASE |
 132                         PSW_MASK_EA | PSW_MASK_BA);
 133         /* Disable lowcore protection */
 134         __ctl_clear_bit(0, 28);
 135         current_lc = lowcore_ptr[smp_processor_id()];
 136         lc = lowcore_ptr[0];
 137         if (!lc)
 138                 lc = current_lc;
 139         lc->restart_psw.mask =
 140                 PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA;
 141         lc->restart_psw.addr = PSW_ADDR_AMODE | (unsigned long) smp_restart_cpu;
 142         if (!cpu_online(0))
 143                 smp_switch_to_cpu(func, data, 0, stap(), __cpu_logical_map[0]);
 144         while (sigp(0, sigp_stop_and_store_status) == sigp_busy)
 145                 cpu_relax();
 146         sp = lc->panic_stack;
 147         sp -= sizeof(struct pt_regs);
 148         regs = (struct pt_regs *) sp;
 149         memcpy(&regs->gprs, &current_lc->gpregs_save_area, sizeof(regs->gprs));
 150         regs->psw = current_lc->psw_save_area;
 151         sp -= STACK_FRAME_OVERHEAD;
 152         sf = (struct stack_frame *) sp;
 153         sf->back_chain = 0;
 154         smp_switch_to_cpu(func, data, sp, stap(), __cpu_logical_map[0]);
 155 }
 156
 157 static void smp_stop_cpu(void)
 158 {
 159         while (sigp(smp_processor_id(), sigp_stop) == sigp_busy)
 160                 cpu_relax();
 161 }
 162
 163 void smp_send_stop(void)
 164 {
 165         cpumask_t cpumask;
 166         int cpu;
 167         u64 end;
 168
 169         /* Disable all interrupts/machine checks */
 170         __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT);
 171         trace_hardirqs_off();
 172
 173         cpumask_copy(&cpumask, cpu_online_mask);
 174         cpumask_clear_cpu(smp_processor_id(), &cpumask);
 175
 176         if (oops_in_progress) {
 177                 /*
 178                  * Give the other cpus the opportunity to complete
 179                  * outstanding interrupts before stopping them.
 180                  */
 181                 end = get_clock() + (1000000UL << 12);
 182                 for_each_cpu(cpu, &cpumask) {
 183                         set_bit(ec_stop_cpu, (unsigned long *)
 184                                 &lowcore_ptr[cpu]->ext_call_fast);
 185                         while (sigp(cpu, sigp_emergency_signal) == sigp_busy &&
 186                                get_clock() < end)
 187                                 cpu_relax();
 188                 }
 189                 while (get_clock() < end) {
 190                         for_each_cpu(cpu, &cpumask)
 191                                 if (cpu_stopped(cpu))
 192                                         cpumask_clear_cpu(cpu, &cpumask);
 193                         if (cpumask_empty(&cpumask))
 194                                 break;
 195                         cpu_relax();
 196                 }
 197         }
 198
 199         /* stop all processors */
 200         for_each_cpu(cpu, &cpumask) {
 201                 while (sigp(cpu, sigp_stop) == sigp_busy)
 202                         cpu_relax();
 203                 while (!cpu_stopped(cpu))
 204                         cpu_relax();
 205         }
 206 }
 207
 208 /*
 209  * This is the main routine where commands issued by other
 210  * cpus are handled.
 211  */
 212
 213 static void do_ext_call_interrupt(unsigned int ext_int_code,
 214                                   unsigned int param32, unsigned long param64)
 215 {
 216         unsigned long bits;
 217
 218         if ((ext_int_code & 0xffff) == 0x1202)
 219                 kstat_cpu(smp_processor_id()).irqs[EXTINT_EXC]++;
 220         else
 221                 kstat_cpu(smp_processor_id()).irqs[EXTINT_EMS]++;
 222         /*
 223          * handle bit signal external calls
 224          */
 225         bits = xchg(&S390_lowcore.ext_call_fast, 0);
 226
 227         if (test_bit(ec_stop_cpu, &bits))
 228                 smp_stop_cpu();
 229
 230         if (test_bit(ec_schedule, &bits))
 231                 scheduler_ipi();
 232
 233         if (test_bit(ec_call_function, &bits))
 234                 generic_smp_call_function_interrupt();
 235
 236         if (test_bit(ec_call_function_single, &bits))
 237                 generic_smp_call_function_single_interrupt();
 238
 239 }
 240
 241 /*
 242  * Send an external call sigp to another cpu and return without waiting
 243  * for its completion.
 244  */
 245 static void smp_ext_bitcall(int cpu, int sig)
 246 {
 247         int order;
 248
 249         /*
 250          * Set signaling bit in lowcore of target cpu and kick it
 251          */
 252         set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
 253         while (1) {
 254                 order = smp_vcpu_scheduled(cpu) ?
 255                         sigp_external_call : sigp_emergency_signal;
 256                 if (sigp(cpu, order) != sigp_busy)
 257                         break;
 258                 udelay(10);
 259         }
 260 }
 261
 262 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 263 {
 264         int cpu;
 265
 266         for_each_cpu(cpu, mask)
 267                 smp_ext_bitcall(cpu, ec_call_function);
 268 }
 269
 270 void arch_send_call_function_single_ipi(int cpu)
 271 {
 272         smp_ext_bitcall(cpu, ec_call_function_single);
 273 }
 274
 275 #ifndef CONFIG_64BIT
 276 /*
 277  * this function sends a 'purge tlb' signal to another CPU.
 278  */
 279 static void smp_ptlb_callback(void *info)
 280 {
 281         __tlb_flush_local();
 282 }
 283
 284 void smp_ptlb_all(void)
 285 {
 286         on_each_cpu(smp_ptlb_callback, NULL, 1);
 287 }
 288 EXPORT_SYMBOL(smp_ptlb_all);
 289 #endif /* ! CONFIG_64BIT */
 290
 291 /*
 292  * this function sends a 'reschedule' IPI to another CPU.
 293  * it goes straight through and wastes no time serializing
 294  * anything. Worst case is that we lose a reschedule ...
 295  */
 296 void smp_send_reschedule(int cpu)
 297 {
 298         smp_ext_bitcall(cpu, ec_schedule);
 299 }
 300
 301 /*
 302  * parameter area for the set/clear control bit callbacks
 303  */
 304 struct ec_creg_mask_parms {
 305         unsigned long orvals[16];
 306         unsigned long andvals[16];
 307 };
 308
 309 /*
 310  * callback for setting/clearing control bits
 311  */
 312 static void smp_ctl_bit_callback(void *info)
 313 {
 314         struct ec_creg_mask_parms *pp = info;
 315         unsigned long cregs[16];
 316         int i;
 317
 318         __ctl_store(cregs, 0, 15);
 319         for (i = 0; i <= 15; i++)
 320                 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
 321         __ctl_load(cregs, 0, 15);
 322 }
 323
 324 /*
 325  * Set a bit in a control register of all cpus
 326  */
 327 void smp_ctl_set_bit(int cr, int bit)
 328 {
 329         struct ec_creg_mask_parms parms;
 330
 331         memset(&parms.orvals, 0, sizeof(parms.orvals));
 332         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
 333         parms.orvals[cr] = 1UL << bit;
 334         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 335 }
 336 EXPORT_SYMBOL(smp_ctl_set_bit);
 337
 338 /*
 339  * Clear a bit in a control register of all cpus
 340  */
 341 void smp_ctl_clear_bit(int cr, int bit)
 342 {
 343         struct ec_creg_mask_parms parms;
 344
 345         memset(&parms.orvals, 0, sizeof(parms.orvals));
 346         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
 347         parms.andvals[cr] = ~(1UL << bit);
 348         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 349 }
 350 EXPORT_SYMBOL(smp_ctl_clear_bit);
 351
 352 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_CRASH_DUMP)
 353
 354 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
 355 {
 356         if (ipl_info.type != IPL_TYPE_FCP_DUMP && !OLDMEM_BASE)
 357                 return;
 358         if (is_kdump_kernel())
 359                 return;
 360         if (cpu >= NR_CPUS) {
 361                 pr_warning("CPU %i exceeds the maximum %i and is excluded from "
 362                            "the dump\n", cpu, NR_CPUS - 1);
 363                 return;
 364         }
 365         zfcpdump_save_areas[cpu] = kmalloc(sizeof(struct save_area), GFP_KERNEL);
 366         while (raw_sigp(phy_cpu, sigp_stop_and_store_status) == sigp_busy)
 367                 cpu_relax();
 368         memcpy_real(zfcpdump_save_areas[cpu],
 369                     (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
 370                     sizeof(struct save_area));
 371 }
 372
 373 struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
 374 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
 375
 376 #else
 377
 378 static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
 379
 380 #endif /* CONFIG_ZFCPDUMP */
 381
 382 static int cpu_known(int cpu_id)
 383 {
 384         int cpu;
 385
 386         for_each_present_cpu(cpu) {
 387                 if (__cpu_logical_map[cpu] == cpu_id)
 388                         return 1;
 389         }
 390         return 0;
 391 }
 392
 393 static int smp_rescan_cpus_sigp(cpumask_t avail)
 394 {
 395         int cpu_id, logical_cpu;
 396
 397         logical_cpu = cpumask_first(&avail);
 398         if (logical_cpu >= nr_cpu_ids)
 399                 return 0;
 400         for (cpu_id = 0; cpu_id <= MAX_CPU_ADDRESS; cpu_id++) {
 401                 if (cpu_known(cpu_id))
 402                         continue;
 403                 __cpu_logical_map[logical_cpu] = cpu_id;
 404                 cpu_set_polarization(logical_cpu, POLARIZATION_UNKNOWN);
 405                 if (!cpu_stopped(logical_cpu))
 406                         continue;
 407                 set_cpu_present(logical_cpu, true);
 408                 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
 409                 logical_cpu = cpumask_next(logical_cpu, &avail);
 410                 if (logical_cpu >= nr_cpu_ids)
 411                         break;
 412         }
 413         return 0;
 414 }
 415
 416 static int smp_rescan_cpus_sclp(cpumask_t avail)
 417 {
 418         struct sclp_cpu_info *info;
 419         int cpu_id, logical_cpu, cpu;
 420         int rc;
 421
 422         logical_cpu = cpumask_first(&avail);
 423         if (logical_cpu >= nr_cpu_ids)
 424                 return 0;
 425         info = kmalloc(sizeof(*info), GFP_KERNEL);
 426         if (!info)
 427                 return -ENOMEM;
 428         rc = sclp_get_cpu_info(info);
 429         if (rc)
 430                 goto out;
 431         for (cpu = 0; cpu < info->combined; cpu++) {
 432                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
 433                         continue;
 434                 cpu_id = info->cpu[cpu].address;
 435                 if (cpu_known(cpu_id))
 436                         continue;
 437                 __cpu_logical_map[logical_cpu] = cpu_id;
 438                 cpu_set_polarization(logical_cpu, POLARIZATION_UNKNOWN);
 439                 set_cpu_present(logical_cpu, true);
 440                 if (cpu >= info->configured)
 441                         smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
 442                 else
 443                         smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
 444                 logical_cpu = cpumask_next(logical_cpu, &avail);
 445                 if (logical_cpu >= nr_cpu_ids)
 446                         break;
 447         }
 448 out:
 449         kfree(info);
 450         return rc;
 451 }
 452
 453 static int __smp_rescan_cpus(void)
 454 {
 455         cpumask_t avail;
 456
 457         cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
 458         if (smp_use_sigp_detection)
 459                 return smp_rescan_cpus_sigp(avail);
 460         else
 461                 return smp_rescan_cpus_sclp(avail);
 462 }
 463
 464 static void __init smp_detect_cpus(void)
 465 {
 466         unsigned int cpu, c_cpus, s_cpus;
 467         struct sclp_cpu_info *info;
 468         u16 boot_cpu_addr, cpu_addr;
 469
 470         c_cpus = 1;
 471         s_cpus = 0;
 472         boot_cpu_addr = __cpu_logical_map[0];
 473         info = kmalloc(sizeof(*info), GFP_KERNEL);
 474         if (!info)
 475                 panic("smp_detect_cpus failed to allocate memory\n");
 476 #ifdef CONFIG_CRASH_DUMP
 477         if (OLDMEM_BASE && !is_kdump_kernel()) {
 478                 struct save_area *save_area;
 479
 480                 save_area = kmalloc(sizeof(*save_area), GFP_KERNEL);
 481                 if (!save_area)
 482                         panic("could not allocate memory for save area\n");
 483                 copy_oldmem_page(1, (void *) save_area, sizeof(*save_area),
 484                                  0x200, 0);
 485                 zfcpdump_save_areas[0] = save_area;
 486         }
 487 #endif
 488         /* Use sigp detection algorithm if sclp doesn't work. */
 489         if (sclp_get_cpu_info(info)) {
 490                 smp_use_sigp_detection = 1;
 491                 for (cpu = 0; cpu <= MAX_CPU_ADDRESS; cpu++) {
 492                         if (cpu == boot_cpu_addr)
 493                                 continue;
 494                         if (!raw_cpu_stopped(cpu))
 495                                 continue;
 496                         smp_get_save_area(c_cpus, cpu);
 497                         c_cpus++;
 498                 }
 499                 goto out;
 500         }
 501
 502         if (info->has_cpu_type) {
 503                 for (cpu = 0; cpu < info->combined; cpu++) {
 504                         if (info->cpu[cpu].address == boot_cpu_addr) {
 505                                 smp_cpu_type = info->cpu[cpu].type;
 506                                 break;
 507                         }
 508                 }
 509         }
 510
 511         for (cpu = 0; cpu < info->combined; cpu++) {
 512                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
 513                         continue;
 514                 cpu_addr = info->cpu[cpu].address;
 515                 if (cpu_addr == boot_cpu_addr)
 516                         continue;
 517                 if (!raw_cpu_stopped(cpu_addr)) {
 518                         s_cpus++;
 519                         continue;
 520                 }
 521                 smp_get_save_area(c_cpus, cpu_addr);
 522                 c_cpus++;
 523         }
 524 out:
 525         kfree(info);
 526         pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
 527         get_online_cpus();
 528         __smp_rescan_cpus();
 529         put_online_cpus();
 530 }
 531
 532 /*
 533  *      Activate a secondary processor.
 534  */
 535 int __cpuinit start_secondary(void *cpuvoid)
 536 {
 537         cpu_init();
 538         preempt_disable();
 539         init_cpu_timer();
 540         init_cpu_vtimer();
 541         pfault_init();
 542
 543         notify_cpu_starting(smp_processor_id());
 544         ipi_call_lock();
 545         set_cpu_online(smp_processor_id(), true);
 546         ipi_call_unlock();
 547         __ctl_clear_bit(0, 28); /* Disable lowcore protection */
 548         S390_lowcore.restart_psw.mask =
 549                 PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA;
 550         S390_lowcore.restart_psw.addr =
 551                 PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler;
 552         __ctl_set_bit(0, 28); /* Enable lowcore protection */
 553         /*
 554          * Wait until the cpu which brought this one up marked it
 555          * active before enabling interrupts.
 556          */
 557         while (!cpumask_test_cpu(smp_processor_id(), cpu_active_mask))
 558                 cpu_relax();
 559         local_irq_enable();
 560         /* cpu_idle will call schedule for us */
 561         cpu_idle();
 562         return 0;
 563 }
 564
 565 struct create_idle {
 566         struct work_struct work;
 567         struct task_struct *idle;
 568         struct completion done;
 569         int cpu;
 570 };
 571
 572 static void __cpuinit smp_fork_idle(struct work_struct *work)
 573 {
 574         struct create_idle *c_idle;
 575
 576         c_idle = container_of(work, struct create_idle, work);
 577         c_idle->idle = fork_idle(c_idle->cpu);
 578         complete(&c_idle->done);
 579 }
 580
 581 static int __cpuinit smp_alloc_lowcore(int cpu)
 582 {
 583         unsigned long async_stack, panic_stack;
 584         struct _lowcore *lowcore;
 585
 586         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
 587         if (!lowcore)
 588                 return -ENOMEM;
 589         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
 590         panic_stack = __get_free_page(GFP_KERNEL);
 591         if (!panic_stack || !async_stack)
 592                 goto out;
 593         memcpy(lowcore, &S390_lowcore, 512);
 594         memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
 595         lowcore->async_stack = async_stack + ASYNC_SIZE;
 596         lowcore->panic_stack = panic_stack + PAGE_SIZE;
 597         lowcore->restart_psw.mask =
 598                 PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA;
 599         lowcore->restart_psw.addr =
 600                 PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
 601         if (user_mode != HOME_SPACE_MODE)
 602                 lowcore->restart_psw.mask |= PSW_ASC_HOME;
 603 #ifndef CONFIG_64BIT
 604         if (MACHINE_HAS_IEEE) {
 605                 unsigned long save_area;
 606
 607                 save_area = get_zeroed_page(GFP_KERNEL);
 608                 if (!save_area)
 609                         goto out;
 610                 lowcore->extended_save_area_addr = (u32) save_area;
 611         }
 612 #else
 613         if (vdso_alloc_per_cpu(cpu, lowcore))
 614                 goto out;
 615 #endif
 616         lowcore_ptr[cpu] = lowcore;
 617         return 0;
 618
 619 out:
 620         free_page(panic_stack);
 621         free_pages(async_stack, ASYNC_ORDER);
 622         free_pages((unsigned long) lowcore, LC_ORDER);
 623         return -ENOMEM;
 624 }
 625
 626 static void smp_free_lowcore(int cpu)
 627 {
 628         struct _lowcore *lowcore;
 629
 630         lowcore = lowcore_ptr[cpu];
 631 #ifndef CONFIG_64BIT
 632         if (MACHINE_HAS_IEEE)
 633                 free_page((unsigned long) lowcore->extended_save_area_addr);
 634 #else
 635         vdso_free_per_cpu(cpu, lowcore);
 636 #endif
 637         free_page(lowcore->panic_stack - PAGE_SIZE);
 638         free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
 639         free_pages((unsigned long) lowcore, LC_ORDER);
 640         lowcore_ptr[cpu] = NULL;
 641 }
 642
 643 /* Upping and downing of CPUs */
 644 int __cpuinit __cpu_up(unsigned int cpu)
 645 {
 646         struct _lowcore *cpu_lowcore;
 647         struct create_idle c_idle;
 648         struct task_struct *idle;
 649         struct stack_frame *sf;
 650         u32 lowcore;
 651         int ccode;
 652
 653         if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
 654                 return -EIO;
 655         idle = current_set[cpu];
 656         if (!idle) {
 657                 c_idle.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done);
 658                 INIT_WORK_ONSTACK(&c_idle.work, smp_fork_idle);
 659                 c_idle.cpu = cpu;
 660                 schedule_work(&c_idle.work);
 661                 wait_for_completion(&c_idle.done);
 662                 if (IS_ERR(c_idle.idle))
 663                         return PTR_ERR(c_idle.idle);
 664                 idle = c_idle.idle;
 665                 current_set[cpu] = c_idle.idle;
 666         }
 667         init_idle(idle, cpu);
 668         if (smp_alloc_lowcore(cpu))
 669                 return -ENOMEM;
 670         do {
 671                 ccode = sigp(cpu, sigp_initial_cpu_reset);
 672                 if (ccode == sigp_busy)
 673                         udelay(10);
 674                 if (ccode == sigp_not_operational)
 675                         goto err_out;
 676         } while (ccode == sigp_busy);
 677
 678         lowcore = (u32)(unsigned long)lowcore_ptr[cpu];
 679         while (sigp_p(lowcore, cpu, sigp_set_prefix) == sigp_busy)
 680                 udelay(10);
 681
 682         cpu_lowcore = lowcore_ptr[cpu];
 683         cpu_lowcore->kernel_stack = (unsigned long)
 684                 task_stack_page(idle) + THREAD_SIZE;
 685         cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
 686         sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
 687                                      - sizeof(struct pt_regs)
 688                                      - sizeof(struct stack_frame));
 689         memset(sf, 0, sizeof(struct stack_frame));
 690         sf->gprs[9] = (unsigned long) sf;
 691         cpu_lowcore->gpregs_save_area[15] = (unsigned long) sf;
 692         __ctl_store(cpu_lowcore->cregs_save_area, 0, 15);
 693         atomic_inc(&init_mm.context.attach_count);
 694         asm volatile(
 695                 "       stam    0,15,0(%0)"
 696                 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
 697         cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
 698         cpu_lowcore->current_task = (unsigned long) idle;
 699         cpu_lowcore->cpu_nr = cpu;
 700         cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
 701         cpu_lowcore->machine_flags = S390_lowcore.machine_flags;
 702         cpu_lowcore->ftrace_func = S390_lowcore.ftrace_func;
 703         memcpy(cpu_lowcore->stfle_fac_list, S390_lowcore.stfle_fac_list,
 704                MAX_FACILITY_BIT/8);
 705         eieio();
 706
 707         while (sigp(cpu, sigp_restart) == sigp_busy)
 708                 udelay(10);
 709
 710         while (!cpu_online(cpu))
 711                 cpu_relax();
 712         return 0;
 713
 714 err_out:
 715         smp_free_lowcore(cpu);
 716         return -EIO;
 717 }
 718
 719 static int __init setup_possible_cpus(char *s)
 720 {
 721         int pcpus, cpu;
 722
 723         pcpus = simple_strtoul(s, NULL, 0);
 724         init_cpu_possible(cpumask_of(0));
 725         for (cpu = 1; cpu < pcpus && cpu < nr_cpu_ids; cpu++)
 726                 set_cpu_possible(cpu, true);
 727         return 0;
 728 }
 729 early_param("possible_cpus", setup_possible_cpus);
 730
 731 #ifdef CONFIG_HOTPLUG_CPU
 732
 733 int __cpu_disable(void)
 734 {
 735         struct ec_creg_mask_parms cr_parms;
 736         int cpu = smp_processor_id();
 737
 738         set_cpu_online(cpu, false);
 739
 740         /* Disable pfault pseudo page faults on this cpu. */
 741         pfault_fini();
 742
 743         memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
 744         memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
 745
 746         /* disable all external interrupts */
 747         cr_parms.orvals[0] = 0;
 748         cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 11 |
 749                                 1 << 10 | 1 <<  9 | 1 <<  6 | 1 <<  5 |
 750                                 1 <<  4);
 751         /* disable all I/O interrupts */
 752         cr_parms.orvals[6] = 0;
 753         cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
 754                                 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
 755         /* disable most machine checks */
 756         cr_parms.orvals[14] = 0;
 757         cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
 758                                  1 << 25 | 1 << 24);
 759
 760         smp_ctl_bit_callback(&cr_parms);
 761
 762         return 0;
 763 }
 764
 765 void __cpu_die(unsigned int cpu)
 766 {
 767         /* Wait until target cpu is down */
 768         while (!cpu_stopped(cpu))
 769                 cpu_relax();
 770         while (sigp_p(0, cpu, sigp_set_prefix) == sigp_busy)
 771                 udelay(10);
 772         smp_free_lowcore(cpu);
 773         atomic_dec(&init_mm.context.attach_count);
 774 }
 775
 776 void __noreturn cpu_die(void)
 777 {
 778         idle_task_exit();
 779         while (sigp(smp_processor_id(), sigp_stop) == sigp_busy)
 780                 cpu_relax();
 781         for (;;);
 782 }
 783
 784 #endif /* CONFIG_HOTPLUG_CPU */
 785
 786 void __init smp_prepare_cpus(unsigned int max_cpus)
 787 {
 788 #ifndef CONFIG_64BIT
 789         unsigned long save_area = 0;
 790 #endif
 791         unsigned long async_stack, panic_stack;
 792         struct _lowcore *lowcore;
 793
 794         smp_detect_cpus();
 795
 796         /* request the 0x1201 emergency signal external interrupt */
 797         if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
 798                 panic("Couldn't request external interrupt 0x1201");
 799         /* request the 0x1202 external call external interrupt */
 800         if (register_external_interrupt(0x1202, do_ext_call_interrupt) != 0)
 801                 panic("Couldn't request external interrupt 0x1202");
 802
 803         /* Reallocate current lowcore, but keep its contents. */
 804         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
 805         panic_stack = __get_free_page(GFP_KERNEL);
 806         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
 807         BUG_ON(!lowcore || !panic_stack || !async_stack);
 808 #ifndef CONFIG_64BIT
 809         if (MACHINE_HAS_IEEE)
 810                 save_area = get_zeroed_page(GFP_KERNEL);
 811 #endif
 812         local_irq_disable();
 813         local_mcck_disable();
 814         lowcore_ptr[smp_processor_id()] = lowcore;
 815         *lowcore = S390_lowcore;
 816         lowcore->panic_stack = panic_stack + PAGE_SIZE;
 817         lowcore->async_stack = async_stack + ASYNC_SIZE;
 818 #ifndef CONFIG_64BIT
 819         if (MACHINE_HAS_IEEE)
 820                 lowcore->extended_save_area_addr = (u32) save_area;
 821 #endif
 822         set_prefix((u32)(unsigned long) lowcore);
 823         local_mcck_enable();
 824         local_irq_enable();
 825 #ifdef CONFIG_64BIT
 826         if (vdso_alloc_per_cpu(smp_processor_id(), &S390_lowcore))
 827                 BUG();
 828 #endif
 829 }
 830
 831 void __init smp_prepare_boot_cpu(void)
 832 {
 833         BUG_ON(smp_processor_id() != 0);
 834
 835         current_thread_info()->cpu = 0;
 836         set_cpu_present(0, true);
 837         set_cpu_online(0, true);
 838         S390_lowcore.percpu_offset = __per_cpu_offset[0];
 839         current_set[0] = current;
 840         smp_cpu_state[0] = CPU_STATE_CONFIGURED;
 841         cpu_set_polarization(0, POLARIZATION_UNKNOWN);
 842 }
 843
 844 void __init smp_cpus_done(unsigned int max_cpus)
 845 {
 846 }
 847
 848 void __init smp_setup_processor_id(void)
 849 {
 850         S390_lowcore.cpu_nr = 0;
 851         __cpu_logical_map[0] = stap();
 852 }
 853
 854 /*
 855  * the frequency of the profiling timer can be changed
 856  * by writing a multiplier value into /proc/profile.
 857  *
 858  * usually you want to run this on all CPUs ;)
 859  */
 860 int setup_profiling_timer(unsigned int multiplier)
 861 {
 862         return 0;
 863 }
 864
 865 #ifdef CONFIG_HOTPLUG_CPU
 866 static ssize_t cpu_configure_show(struct device *dev,
 867                                 struct device_attribute *attr, char *buf)
 868 {
 869         ssize_t count;
 870
 871         mutex_lock(&smp_cpu_state_mutex);
 872         count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
 873         mutex_unlock(&smp_cpu_state_mutex);
 874         return count;
 875 }
 876
 877 static ssize_t cpu_configure_store(struct device *dev,
 878                                   struct device_attribute *attr,
 879                                   const char *buf, size_t count)
 880 {
 881         int cpu = dev->id;
 882         int val, rc;
 883         char delim;
 884
 885         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 886                 return -EINVAL;
 887         if (val != 0 && val != 1)
 888                 return -EINVAL;
 889
 890         get_online_cpus();
 891         mutex_lock(&smp_cpu_state_mutex);
 892         rc = -EBUSY;
 893         /* disallow configuration changes of online cpus and cpu 0 */
 894         if (cpu_online(cpu) || cpu == 0)
 895                 goto out;
 896         rc = 0;
 897         switch (val) {
 898         case 0:
 899                 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
 900                         rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
 901                         if (!rc) {
 902                                 smp_cpu_state[cpu] = CPU_STATE_STANDBY;
 903                                 cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
 904                                 topology_expect_change();
 905                         }
 906                 }
 907                 break;
 908         case 1:
 909                 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
 910                         rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
 911                         if (!rc) {
 912                                 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
 913                                 cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
 914                                 topology_expect_change();
 915                         }
 916                 }
 917                 break;
 918         default:
 919                 break;
 920         }
 921 out:
 922         mutex_unlock(&smp_cpu_state_mutex);
 923         put_online_cpus();
 924         return rc ? rc : count;
 925 }
 926 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
 927 #endif /* CONFIG_HOTPLUG_CPU */
 928
 929 static ssize_t show_cpu_address(struct device *dev,
 930                                 struct device_attribute *attr, char *buf)
 931 {
 932         return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
 933 }
 934 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
 935
 936 static struct attribute *cpu_common_attrs[] = {
 937 #ifdef CONFIG_HOTPLUG_CPU
 938         &dev_attr_configure.attr,
 939 #endif
 940         &dev_attr_address.attr,
 941         NULL,
 942 };
 943
 944 static struct attribute_group cpu_common_attr_group = {
 945         .attrs = cpu_common_attrs,
 946 };
 947
 948 static ssize_t show_capability(struct device *dev,
 949                                 struct device_attribute *attr, char *buf)
 950 {
 951         unsigned int capability;
 952         int rc;
 953
 954         rc = get_cpu_capability(&capability);
 955         if (rc)
 956                 return rc;
 957         return sprintf(buf, "%u\n", capability);
 958 }
 959 static DEVICE_ATTR(capability, 0444, show_capability, NULL);
 960
 961 static ssize_t show_idle_count(struct device *dev,
 962                                 struct device_attribute *attr, char *buf)
 963 {
 964         struct s390_idle_data *idle;
 965         unsigned long long idle_count;
 966         unsigned int sequence;
 967
 968         idle = &per_cpu(s390_idle, dev->id);
 969 repeat:
 970         sequence = idle->sequence;
 971         smp_rmb();
 972         if (sequence & 1)
 973                 goto repeat;
 974         idle_count = idle->idle_count;
 975         if (idle->idle_enter)
 976                 idle_count++;
 977         smp_rmb();
 978         if (idle->sequence != sequence)
 979                 goto repeat;
 980         return sprintf(buf, "%llu\n", idle_count);
 981 }
 982 static DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL);
 983
 984 static ssize_t show_idle_time(struct device *dev,
 985                                 struct device_attribute *attr, char *buf)
 986 {
 987         struct s390_idle_data *idle;
 988         unsigned long long now, idle_time, idle_enter;
 989         unsigned int sequence;
 990
 991         idle = &per_cpu(s390_idle, dev->id);
 992         now = get_clock();
 993 repeat:
 994         sequence = idle->sequence;
 995         smp_rmb();
 996         if (sequence & 1)
 997                 goto repeat;
 998         idle_time = idle->idle_time;
 999         idle_enter = idle->idle_enter;
1000         if (idle_enter != 0ULL && idle_enter < now)
1001                 idle_time += now - idle_enter;
1002         smp_rmb();
1003         if (idle->sequence != sequence)
1004                 goto repeat;
1005         return sprintf(buf, "%llu\n", idle_time >> 12);
1006 }
1007 static DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL);
1008
1009 static struct attribute *cpu_online_attrs[] = {
1010         &dev_attr_capability.attr,
1011         &dev_attr_idle_count.attr,
1012         &dev_attr_idle_time_us.attr,
1013         NULL,
1014 };
1015
1016 static struct attribute_group cpu_online_attr_group = {
1017         .attrs = cpu_online_attrs,
1018 };
1019
1020 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
1021                                     unsigned long action, void *hcpu)
1022 {
1023         unsigned int cpu = (unsigned int)(long)hcpu;
1024         struct cpu *c = &per_cpu(cpu_devices, cpu);
1025         struct device *s = &c->dev;
1026         struct s390_idle_data *idle;
1027         int err = 0;
1028
1029         switch (action) {
1030         case CPU_ONLINE:
1031         case CPU_ONLINE_FROZEN:
1032                 idle = &per_cpu(s390_idle, cpu);
1033                 memset(idle, 0, sizeof(struct s390_idle_data));
1034                 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1035                 break;
1036         case CPU_DEAD:
1037         case CPU_DEAD_FROZEN:
1038                 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1039                 break;
1040         }
1041         return notifier_from_errno(err);
1042 }
1043
1044 static struct notifier_block __cpuinitdata smp_cpu_nb = {
1045         .notifier_call = smp_cpu_notify,
1046 };
1047
1048 static int __devinit smp_add_present_cpu(int cpu)
1049 {
1050         struct cpu *c = &per_cpu(cpu_devices, cpu);
1051         struct device *s = &c->dev;
1052         int rc;
1053
1054         c->hotpluggable = 1;
1055         rc = register_cpu(c, cpu);
1056         if (rc)
1057                 goto out;
1058         rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1059         if (rc)
1060                 goto out_cpu;
1061         if (cpu_online(cpu)) {
1062                 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1063                 if (rc)
1064                         goto out_online;
1065         }
1066         rc = topology_cpu_init(c);
1067         if (rc)
1068                 goto out_topology;
1069         return 0;
1070
1071 out_topology:
1072         if (cpu_online(cpu))
1073                 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1074 out_online:
1075         sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1076 out_cpu:
1077 #ifdef CONFIG_HOTPLUG_CPU
1078         unregister_cpu(c);
1079 #endif
1080 out:
1081         return rc;
1082 }
1083
1084 #ifdef CONFIG_HOTPLUG_CPU
1085
1086 int __ref smp_rescan_cpus(void)
1087 {
1088         cpumask_t newcpus;
1089         int cpu;
1090         int rc;
1091
1092         get_online_cpus();
1093         mutex_lock(&smp_cpu_state_mutex);
1094         cpumask_copy(&newcpus, cpu_present_mask);
1095         rc = __smp_rescan_cpus();
1096         if (rc)
1097                 goto out;
1098         cpumask_andnot(&newcpus, cpu_present_mask, &newcpus);
1099         for_each_cpu(cpu, &newcpus) {
1100                 rc = smp_add_present_cpu(cpu);
1101                 if (rc)
1102                         set_cpu_present(cpu, false);
1103         }
1104         rc = 0;
1105 out:
1106         mutex_unlock(&smp_cpu_state_mutex);
1107         put_online_cpus();
1108         if (!cpumask_empty(&newcpus))
1109                 topology_schedule_update();
1110         return rc;
1111 }
1112
1113 static ssize_t __ref rescan_store(struct device *dev,
1114                                   struct device_attribute *attr,
1115                                   const char *buf,
1116                                   size_t count)
1117 {
1118         int rc;
1119
1120         rc = smp_rescan_cpus();
1121         return rc ? rc : count;
1122 }
1123 static DEVICE_ATTR(rescan, 0200, NULL, rescan_store);
1124 #endif /* CONFIG_HOTPLUG_CPU */
1125
1126 static int __init s390_smp_init(void)
1127 {
1128         int cpu, rc;
1129
1130         register_cpu_notifier(&smp_cpu_nb);
1131 #ifdef CONFIG_HOTPLUG_CPU
1132         rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1133         if (rc)
1134                 return rc;
1135 #endif
1136         for_each_present_cpu(cpu) {
1137                 rc = smp_add_present_cpu(cpu);
1138                 if (rc)
1139                         return rc;
1140         }
1141         return 0;
1142 }
1143 subsys_initcall(s390_smp_init);