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/module.h>
  27 #include <linux/init.h>
  28 #include <linux/mm.h>
  29 #include <linux/err.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/kernel_stat.h>
  32 #include <linux/delay.h>
  33 #include <linux/cache.h>
  34 #include <linux/interrupt.h>
  35 #include <linux/irqflags.h>
  36 #include <linux/cpu.h>
  37 #include <linux/timex.h>
  38 #include <linux/bootmem.h>
  39 #include <linux/slab.h>
  40 #include <asm/asm-offsets.h>
  41 #include <asm/ipl.h>
  42 #include <asm/setup.h>
  43 #include <asm/sigp.h>
  44 #include <asm/pgalloc.h>
  45 #include <asm/irq.h>
  46 #include <asm/s390_ext.h>
  47 #include <asm/cpcmd.h>
  48 #include <asm/tlbflush.h>
  49 #include <asm/timer.h>
  50 #include <asm/lowcore.h>
  51 #include <asm/sclp.h>
  52 #include <asm/cputime.h>
  53 #include <asm/vdso.h>
  54 #include <asm/cpu.h>
  55 #include "entry.h"
  56
  57 /* logical cpu to cpu address */
  58 unsigned short __cpu_logical_map[NR_CPUS];
  59
  60 static struct task_struct *current_set[NR_CPUS];
  61
  62 static u8 smp_cpu_type;
  63 static int smp_use_sigp_detection;
  64
  65 enum s390_cpu_state {
  66         CPU_STATE_STANDBY,
  67         CPU_STATE_CONFIGURED,
  68 };
  69
  70 DEFINE_MUTEX(smp_cpu_state_mutex);
  71 int smp_cpu_polarization[NR_CPUS];
  72 static int smp_cpu_state[NR_CPUS];
  73 static int cpu_management;
  74
  75 static DEFINE_PER_CPU(struct cpu, cpu_devices);
  76
  77 static void smp_ext_bitcall(int, int);
  78
  79 static int raw_cpu_stopped(int cpu)
  80 {
  81         u32 status;
  82
  83         switch (raw_sigp_ps(&status, 0, cpu, sigp_sense)) {
  84         case sigp_status_stored:
  85                 /* Check for stopped and check stop state */
  86                 if (status & 0x50)
  87                         return 1;
  88                 break;
  89         default:
  90                 break;
  91         }
  92         return 0;
  93 }
  94
  95 static inline int cpu_stopped(int cpu)
  96 {
  97         return raw_cpu_stopped(cpu_logical_map(cpu));
  98 }
  99
 100 void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
 101 {
 102         struct _lowcore *lc, *current_lc;
 103         struct stack_frame *sf;
 104         struct pt_regs *regs;
 105         unsigned long sp;
 106
 107         if (smp_processor_id() == 0)
 108                 func(data);
 109         __load_psw_mask(PSW_BASE_BITS | PSW_DEFAULT_KEY);
 110         /* Disable lowcore protection */
 111         __ctl_clear_bit(0, 28);
 112         current_lc = lowcore_ptr[smp_processor_id()];
 113         lc = lowcore_ptr[0];
 114         if (!lc)
 115                 lc = current_lc;
 116         lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
 117         lc->restart_psw.addr = PSW_ADDR_AMODE | (unsigned long) smp_restart_cpu;
 118         if (!cpu_online(0))
 119                 smp_switch_to_cpu(func, data, 0, stap(), __cpu_logical_map[0]);
 120         while (sigp(0, sigp_stop_and_store_status) == sigp_busy)
 121                 cpu_relax();
 122         sp = lc->panic_stack;
 123         sp -= sizeof(struct pt_regs);
 124         regs = (struct pt_regs *) sp;
 125         memcpy(&regs->gprs, &current_lc->gpregs_save_area, sizeof(regs->gprs));
 126         regs->psw = lc->psw_save_area;
 127         sp -= STACK_FRAME_OVERHEAD;
 128         sf = (struct stack_frame *) sp;
 129         sf->back_chain = regs->gprs[15];
 130         smp_switch_to_cpu(func, data, sp, stap(), __cpu_logical_map[0]);
 131 }
 132
 133 void smp_send_stop(void)
 134 {
 135         int cpu, rc;
 136
 137         /* Disable all interrupts/machine checks */
 138         __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
 139         trace_hardirqs_off();
 140
 141         /* stop all processors */
 142         for_each_online_cpu(cpu) {
 143                 if (cpu == smp_processor_id())
 144                         continue;
 145                 do {
 146                         rc = sigp(cpu, sigp_stop);
 147                 } while (rc == sigp_busy);
 148
 149                 while (!cpu_stopped(cpu))
 150                         cpu_relax();
 151         }
 152 }
 153
 154 /*
 155  * This is the main routine where commands issued by other
 156  * cpus are handled.
 157  */
 158
 159 static void do_ext_call_interrupt(__u16 code)
 160 {
 161         unsigned long bits;
 162
 163         /*
 164          * handle bit signal external calls
 165          *
 166          * For the ec_schedule signal we have to do nothing. All the work
 167          * is done automatically when we return from the interrupt.
 168          */
 169         bits = xchg(&S390_lowcore.ext_call_fast, 0);
 170
 171         if (test_bit(ec_call_function, &bits))
 172                 generic_smp_call_function_interrupt();
 173
 174         if (test_bit(ec_call_function_single, &bits))
 175                 generic_smp_call_function_single_interrupt();
 176 }
 177
 178 /*
 179  * Send an external call sigp to another cpu and return without waiting
 180  * for its completion.
 181  */
 182 static void smp_ext_bitcall(int cpu, int sig)
 183 {
 184         /*
 185          * Set signaling bit in lowcore of target cpu and kick it
 186          */
 187         set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
 188         while (sigp(cpu, sigp_emergency_signal) == sigp_busy)
 189                 udelay(10);
 190 }
 191
 192 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 193 {
 194         int cpu;
 195
 196         for_each_cpu(cpu, mask)
 197                 smp_ext_bitcall(cpu, ec_call_function);
 198 }
 199
 200 void arch_send_call_function_single_ipi(int cpu)
 201 {
 202         smp_ext_bitcall(cpu, ec_call_function_single);
 203 }
 204
 205 #ifndef CONFIG_64BIT
 206 /*
 207  * this function sends a 'purge tlb' signal to another CPU.
 208  */
 209 static void smp_ptlb_callback(void *info)
 210 {
 211         __tlb_flush_local();
 212 }
 213
 214 void smp_ptlb_all(void)
 215 {
 216         on_each_cpu(smp_ptlb_callback, NULL, 1);
 217 }
 218 EXPORT_SYMBOL(smp_ptlb_all);
 219 #endif /* ! CONFIG_64BIT */
 220
 221 /*
 222  * this function sends a 'reschedule' IPI to another CPU.
 223  * it goes straight through and wastes no time serializing
 224  * anything. Worst case is that we lose a reschedule ...
 225  */
 226 void smp_send_reschedule(int cpu)
 227 {
 228         smp_ext_bitcall(cpu, ec_schedule);
 229 }
 230
 231 /*
 232  * parameter area for the set/clear control bit callbacks
 233  */
 234 struct ec_creg_mask_parms {
 235         unsigned long orvals[16];
 236         unsigned long andvals[16];
 237 };
 238
 239 /*
 240  * callback for setting/clearing control bits
 241  */
 242 static void smp_ctl_bit_callback(void *info)
 243 {
 244         struct ec_creg_mask_parms *pp = info;
 245         unsigned long cregs[16];
 246         int i;
 247
 248         __ctl_store(cregs, 0, 15);
 249         for (i = 0; i <= 15; i++)
 250                 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
 251         __ctl_load(cregs, 0, 15);
 252 }
 253
 254 /*
 255  * Set a bit in a control register of all cpus
 256  */
 257 void smp_ctl_set_bit(int cr, int bit)
 258 {
 259         struct ec_creg_mask_parms parms;
 260
 261         memset(&parms.orvals, 0, sizeof(parms.orvals));
 262         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
 263         parms.orvals[cr] = 1 << bit;
 264         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 265 }
 266 EXPORT_SYMBOL(smp_ctl_set_bit);
 267
 268 /*
 269  * Clear a bit in a control register of all cpus
 270  */
 271 void smp_ctl_clear_bit(int cr, int bit)
 272 {
 273         struct ec_creg_mask_parms parms;
 274
 275         memset(&parms.orvals, 0, sizeof(parms.orvals));
 276         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
 277         parms.andvals[cr] = ~(1L << bit);
 278         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 279 }
 280 EXPORT_SYMBOL(smp_ctl_clear_bit);
 281
 282 #ifdef CONFIG_ZFCPDUMP
 283
 284 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
 285 {
 286         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
 287                 return;
 288         if (cpu >= NR_CPUS) {
 289                 pr_warning("CPU %i exceeds the maximum %i and is excluded from "
 290                            "the dump\n", cpu, NR_CPUS - 1);
 291                 return;
 292         }
 293         zfcpdump_save_areas[cpu] = kmalloc(sizeof(struct save_area), GFP_KERNEL);
 294         while (raw_sigp(phy_cpu, sigp_stop_and_store_status) == sigp_busy)
 295                 cpu_relax();
 296         memcpy_real(zfcpdump_save_areas[cpu],
 297                     (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
 298                     sizeof(struct save_area));
 299 }
 300
 301 struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
 302 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
 303
 304 #else
 305
 306 static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
 307
 308 #endif /* CONFIG_ZFCPDUMP */
 309
 310 static int cpu_known(int cpu_id)
 311 {
 312         int cpu;
 313
 314         for_each_present_cpu(cpu) {
 315                 if (__cpu_logical_map[cpu] == cpu_id)
 316                         return 1;
 317         }
 318         return 0;
 319 }
 320
 321 static int smp_rescan_cpus_sigp(cpumask_t avail)
 322 {
 323         int cpu_id, logical_cpu;
 324
 325         logical_cpu = cpumask_first(&avail);
 326         if (logical_cpu >= nr_cpu_ids)
 327                 return 0;
 328         for (cpu_id = 0; cpu_id <= MAX_CPU_ADDRESS; cpu_id++) {
 329                 if (cpu_known(cpu_id))
 330                         continue;
 331                 __cpu_logical_map[logical_cpu] = cpu_id;
 332                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
 333                 if (!cpu_stopped(logical_cpu))
 334                         continue;
 335                 cpu_set(logical_cpu, cpu_present_map);
 336                 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
 337                 logical_cpu = cpumask_next(logical_cpu, &avail);
 338                 if (logical_cpu >= nr_cpu_ids)
 339                         break;
 340         }
 341         return 0;
 342 }
 343
 344 static int smp_rescan_cpus_sclp(cpumask_t avail)
 345 {
 346         struct sclp_cpu_info *info;
 347         int cpu_id, logical_cpu, cpu;
 348         int rc;
 349
 350         logical_cpu = cpumask_first(&avail);
 351         if (logical_cpu >= nr_cpu_ids)
 352                 return 0;
 353         info = kmalloc(sizeof(*info), GFP_KERNEL);
 354         if (!info)
 355                 return -ENOMEM;
 356         rc = sclp_get_cpu_info(info);
 357         if (rc)
 358                 goto out;
 359         for (cpu = 0; cpu < info->combined; cpu++) {
 360                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
 361                         continue;
 362                 cpu_id = info->cpu[cpu].address;
 363                 if (cpu_known(cpu_id))
 364                         continue;
 365                 __cpu_logical_map[logical_cpu] = cpu_id;
 366                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
 367                 cpu_set(logical_cpu, cpu_present_map);
 368                 if (cpu >= info->configured)
 369                         smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
 370                 else
 371                         smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
 372                 logical_cpu = cpumask_next(logical_cpu, &avail);
 373                 if (logical_cpu >= nr_cpu_ids)
 374                         break;
 375         }
 376 out:
 377         kfree(info);
 378         return rc;
 379 }
 380
 381 static int __smp_rescan_cpus(void)
 382 {
 383         cpumask_t avail;
 384
 385         cpus_xor(avail, cpu_possible_map, cpu_present_map);
 386         if (smp_use_sigp_detection)
 387                 return smp_rescan_cpus_sigp(avail);
 388         else
 389                 return smp_rescan_cpus_sclp(avail);
 390 }
 391
 392 static void __init smp_detect_cpus(void)
 393 {
 394         unsigned int cpu, c_cpus, s_cpus;
 395         struct sclp_cpu_info *info;
 396         u16 boot_cpu_addr, cpu_addr;
 397
 398         c_cpus = 1;
 399         s_cpus = 0;
 400         boot_cpu_addr = __cpu_logical_map[0];
 401         info = kmalloc(sizeof(*info), GFP_KERNEL);
 402         if (!info)
 403                 panic("smp_detect_cpus failed to allocate memory\n");
 404         /* Use sigp detection algorithm if sclp doesn't work. */
 405         if (sclp_get_cpu_info(info)) {
 406                 smp_use_sigp_detection = 1;
 407                 for (cpu = 0; cpu <= MAX_CPU_ADDRESS; cpu++) {
 408                         if (cpu == boot_cpu_addr)
 409                                 continue;
 410                         if (!raw_cpu_stopped(cpu))
 411                                 continue;
 412                         smp_get_save_area(c_cpus, cpu);
 413                         c_cpus++;
 414                 }
 415                 goto out;
 416         }
 417
 418         if (info->has_cpu_type) {
 419                 for (cpu = 0; cpu < info->combined; cpu++) {
 420                         if (info->cpu[cpu].address == boot_cpu_addr) {
 421                                 smp_cpu_type = info->cpu[cpu].type;
 422                                 break;
 423                         }
 424                 }
 425         }
 426
 427         for (cpu = 0; cpu < info->combined; cpu++) {
 428                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
 429                         continue;
 430                 cpu_addr = info->cpu[cpu].address;
 431                 if (cpu_addr == boot_cpu_addr)
 432                         continue;
 433                 if (!raw_cpu_stopped(cpu_addr)) {
 434                         s_cpus++;
 435                         continue;
 436                 }
 437                 smp_get_save_area(c_cpus, cpu_addr);
 438                 c_cpus++;
 439         }
 440 out:
 441         kfree(info);
 442         pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
 443         get_online_cpus();
 444         __smp_rescan_cpus();
 445         put_online_cpus();
 446 }
 447
 448 /*
 449  *      Activate a secondary processor.
 450  */
 451 int __cpuinit start_secondary(void *cpuvoid)
 452 {
 453         /* Setup the cpu */
 454         cpu_init();
 455         preempt_disable();
 456         /* Enable TOD clock interrupts on the secondary cpu. */
 457         init_cpu_timer();
 458         /* Enable cpu timer interrupts on the secondary cpu. */
 459         init_cpu_vtimer();
 460         /* Enable pfault pseudo page faults on this cpu. */
 461         pfault_init();
 462
 463         /* call cpu notifiers */
 464         notify_cpu_starting(smp_processor_id());
 465         /* Mark this cpu as online */
 466         ipi_call_lock();
 467         cpu_set(smp_processor_id(), cpu_online_map);
 468         ipi_call_unlock();
 469         /* Switch on interrupts */
 470         local_irq_enable();
 471         /* Print info about this processor */
 472         print_cpu_info();
 473         /* cpu_idle will call schedule for us */
 474         cpu_idle();
 475         return 0;
 476 }
 477
 478 static void __init smp_create_idle(unsigned int cpu)
 479 {
 480         struct task_struct *p;
 481
 482         /*
 483          *  don't care about the psw and regs settings since we'll never
 484          *  reschedule the forked task.
 485          */
 486         p = fork_idle(cpu);
 487         if (IS_ERR(p))
 488                 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
 489         current_set[cpu] = p;
 490 }
 491
 492 static int __cpuinit smp_alloc_lowcore(int cpu)
 493 {
 494         unsigned long async_stack, panic_stack;
 495         struct _lowcore *lowcore;
 496
 497         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
 498         if (!lowcore)
 499                 return -ENOMEM;
 500         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
 501         panic_stack = __get_free_page(GFP_KERNEL);
 502         if (!panic_stack || !async_stack)
 503                 goto out;
 504         memcpy(lowcore, &S390_lowcore, 512);
 505         memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
 506         lowcore->async_stack = async_stack + ASYNC_SIZE;
 507         lowcore->panic_stack = panic_stack + PAGE_SIZE;
 508
 509 #ifndef CONFIG_64BIT
 510         if (MACHINE_HAS_IEEE) {
 511                 unsigned long save_area;
 512
 513                 save_area = get_zeroed_page(GFP_KERNEL);
 514                 if (!save_area)
 515                         goto out;
 516                 lowcore->extended_save_area_addr = (u32) save_area;
 517         }
 518 #else
 519         if (vdso_alloc_per_cpu(cpu, lowcore))
 520                 goto out;
 521 #endif
 522         lowcore_ptr[cpu] = lowcore;
 523         return 0;
 524
 525 out:
 526         free_page(panic_stack);
 527         free_pages(async_stack, ASYNC_ORDER);
 528         free_pages((unsigned long) lowcore, LC_ORDER);
 529         return -ENOMEM;
 530 }
 531
 532 static void smp_free_lowcore(int cpu)
 533 {
 534         struct _lowcore *lowcore;
 535
 536         lowcore = lowcore_ptr[cpu];
 537 #ifndef CONFIG_64BIT
 538         if (MACHINE_HAS_IEEE)
 539                 free_page((unsigned long) lowcore->extended_save_area_addr);
 540 #else
 541         vdso_free_per_cpu(cpu, lowcore);
 542 #endif
 543         free_page(lowcore->panic_stack - PAGE_SIZE);
 544         free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
 545         free_pages((unsigned long) lowcore, LC_ORDER);
 546         lowcore_ptr[cpu] = NULL;
 547 }
 548
 549 /* Upping and downing of CPUs */
 550 int __cpuinit __cpu_up(unsigned int cpu)
 551 {
 552         struct _lowcore *cpu_lowcore;
 553         struct task_struct *idle;
 554         struct stack_frame *sf;
 555         u32 lowcore;
 556         int ccode;
 557
 558         if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
 559                 return -EIO;
 560         if (smp_alloc_lowcore(cpu))
 561                 return -ENOMEM;
 562         do {
 563                 ccode = sigp(cpu, sigp_initial_cpu_reset);
 564                 if (ccode == sigp_busy)
 565                         udelay(10);
 566                 if (ccode == sigp_not_operational)
 567                         goto err_out;
 568         } while (ccode == sigp_busy);
 569
 570         lowcore = (u32)(unsigned long)lowcore_ptr[cpu];
 571         while (sigp_p(lowcore, cpu, sigp_set_prefix) == sigp_busy)
 572                 udelay(10);
 573
 574         idle = current_set[cpu];
 575         cpu_lowcore = lowcore_ptr[cpu];
 576         cpu_lowcore->kernel_stack = (unsigned long)
 577                 task_stack_page(idle) + THREAD_SIZE;
 578         cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
 579         sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
 580                                      - sizeof(struct pt_regs)
 581                                      - sizeof(struct stack_frame));
 582         memset(sf, 0, sizeof(struct stack_frame));
 583         sf->gprs[9] = (unsigned long) sf;
 584         cpu_lowcore->save_area[15] = (unsigned long) sf;
 585         __ctl_store(cpu_lowcore->cregs_save_area, 0, 15);
 586         asm volatile(
 587                 "       stam    0,15,0(%0)"
 588                 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
 589         cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
 590         cpu_lowcore->current_task = (unsigned long) idle;
 591         cpu_lowcore->cpu_nr = cpu;
 592         cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
 593         cpu_lowcore->machine_flags = S390_lowcore.machine_flags;
 594         cpu_lowcore->ftrace_func = S390_lowcore.ftrace_func;
 595         eieio();
 596
 597         while (sigp(cpu, sigp_restart) == sigp_busy)
 598                 udelay(10);
 599
 600         while (!cpu_online(cpu))
 601                 cpu_relax();
 602         return 0;
 603
 604 err_out:
 605         smp_free_lowcore(cpu);
 606         return -EIO;
 607 }
 608
 609 static int __init setup_possible_cpus(char *s)
 610 {
 611         int pcpus, cpu;
 612
 613         pcpus = simple_strtoul(s, NULL, 0);
 614         init_cpu_possible(cpumask_of(0));
 615         for (cpu = 1; cpu < pcpus && cpu < nr_cpu_ids; cpu++)
 616                 set_cpu_possible(cpu, true);
 617         return 0;
 618 }
 619 early_param("possible_cpus", setup_possible_cpus);
 620
 621 #ifdef CONFIG_HOTPLUG_CPU
 622
 623 int __cpu_disable(void)
 624 {
 625         struct ec_creg_mask_parms cr_parms;
 626         int cpu = smp_processor_id();
 627
 628         cpu_clear(cpu, cpu_online_map);
 629
 630         /* Disable pfault pseudo page faults on this cpu. */
 631         pfault_fini();
 632
 633         memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
 634         memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
 635
 636         /* disable all external interrupts */
 637         cr_parms.orvals[0] = 0;
 638         cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 12 |
 639                                 1 << 11 | 1 << 10 | 1 <<  6 | 1 <<  4);
 640         /* disable all I/O interrupts */
 641         cr_parms.orvals[6] = 0;
 642         cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
 643                                 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
 644         /* disable most machine checks */
 645         cr_parms.orvals[14] = 0;
 646         cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
 647                                  1 << 25 | 1 << 24);
 648
 649         smp_ctl_bit_callback(&cr_parms);
 650
 651         return 0;
 652 }
 653
 654 void __cpu_die(unsigned int cpu)
 655 {
 656         /* Wait until target cpu is down */
 657         while (!cpu_stopped(cpu))
 658                 cpu_relax();
 659         while (sigp_p(0, cpu, sigp_set_prefix) == sigp_busy)
 660                 udelay(10);
 661         smp_free_lowcore(cpu);
 662         pr_info("Processor %d stopped\n", cpu);
 663 }
 664
 665 void cpu_die(void)
 666 {
 667         idle_task_exit();
 668         while (sigp(smp_processor_id(), sigp_stop) == sigp_busy)
 669                 cpu_relax();
 670         for (;;);
 671 }
 672
 673 #endif /* CONFIG_HOTPLUG_CPU */
 674
 675 void __init smp_prepare_cpus(unsigned int max_cpus)
 676 {
 677 #ifndef CONFIG_64BIT
 678         unsigned long save_area = 0;
 679 #endif
 680         unsigned long async_stack, panic_stack;
 681         struct _lowcore *lowcore;
 682         unsigned int cpu;
 683
 684         smp_detect_cpus();
 685
 686         /* request the 0x1201 emergency signal external interrupt */
 687         if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
 688                 panic("Couldn't request external interrupt 0x1201");
 689         print_cpu_info();
 690
 691         /* Reallocate current lowcore, but keep its contents. */
 692         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
 693         panic_stack = __get_free_page(GFP_KERNEL);
 694         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
 695         BUG_ON(!lowcore || !panic_stack || !async_stack);
 696 #ifndef CONFIG_64BIT
 697         if (MACHINE_HAS_IEEE)
 698                 save_area = get_zeroed_page(GFP_KERNEL);
 699 #endif
 700         local_irq_disable();
 701         local_mcck_disable();
 702         lowcore_ptr[smp_processor_id()] = lowcore;
 703         *lowcore = S390_lowcore;
 704         lowcore->panic_stack = panic_stack + PAGE_SIZE;
 705         lowcore->async_stack = async_stack + ASYNC_SIZE;
 706 #ifndef CONFIG_64BIT
 707         if (MACHINE_HAS_IEEE)
 708                 lowcore->extended_save_area_addr = (u32) save_area;
 709 #endif
 710         set_prefix((u32)(unsigned long) lowcore);
 711         local_mcck_enable();
 712         local_irq_enable();
 713 #ifdef CONFIG_64BIT
 714         if (vdso_alloc_per_cpu(smp_processor_id(), &S390_lowcore))
 715                 BUG();
 716 #endif
 717         for_each_possible_cpu(cpu)
 718                 if (cpu != smp_processor_id())
 719                         smp_create_idle(cpu);
 720 }
 721
 722 void __init smp_prepare_boot_cpu(void)
 723 {
 724         BUG_ON(smp_processor_id() != 0);
 725
 726         current_thread_info()->cpu = 0;
 727         cpu_set(0, cpu_present_map);
 728         cpu_set(0, cpu_online_map);
 729         S390_lowcore.percpu_offset = __per_cpu_offset[0];
 730         current_set[0] = current;
 731         smp_cpu_state[0] = CPU_STATE_CONFIGURED;
 732         smp_cpu_polarization[0] = POLARIZATION_UNKNWN;
 733 }
 734
 735 void __init smp_cpus_done(unsigned int max_cpus)
 736 {
 737 }
 738
 739 void __init smp_setup_processor_id(void)
 740 {
 741         S390_lowcore.cpu_nr = 0;
 742         __cpu_logical_map[0] = stap();
 743 }
 744
 745 /*
 746  * the frequency of the profiling timer can be changed
 747  * by writing a multiplier value into /proc/profile.
 748  *
 749  * usually you want to run this on all CPUs ;)
 750  */
 751 int setup_profiling_timer(unsigned int multiplier)
 752 {
 753         return 0;
 754 }
 755
 756 #ifdef CONFIG_HOTPLUG_CPU
 757 static ssize_t cpu_configure_show(struct sys_device *dev,
 758                                 struct sysdev_attribute *attr, char *buf)
 759 {
 760         ssize_t count;
 761
 762         mutex_lock(&smp_cpu_state_mutex);
 763         count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
 764         mutex_unlock(&smp_cpu_state_mutex);
 765         return count;
 766 }
 767
 768 static ssize_t cpu_configure_store(struct sys_device *dev,
 769                                   struct sysdev_attribute *attr,
 770                                   const char *buf, size_t count)
 771 {
 772         int cpu = dev->id;
 773         int val, rc;
 774         char delim;
 775
 776         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 777                 return -EINVAL;
 778         if (val != 0 && val != 1)
 779                 return -EINVAL;
 780
 781         get_online_cpus();
 782         mutex_lock(&smp_cpu_state_mutex);
 783         rc = -EBUSY;
 784         /* disallow configuration changes of online cpus and cpu 0 */
 785         if (cpu_online(cpu) || cpu == 0)
 786                 goto out;
 787         rc = 0;
 788         switch (val) {
 789         case 0:
 790                 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
 791                         rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
 792                         if (!rc) {
 793                                 smp_cpu_state[cpu] = CPU_STATE_STANDBY;
 794                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 795                         }
 796                 }
 797                 break;
 798         case 1:
 799                 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
 800                         rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
 801                         if (!rc) {
 802                                 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
 803                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 804                         }
 805                 }
 806                 break;
 807         default:
 808                 break;
 809         }
 810 out:
 811         mutex_unlock(&smp_cpu_state_mutex);
 812         put_online_cpus();
 813         return rc ? rc : count;
 814 }
 815 static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
 816 #endif /* CONFIG_HOTPLUG_CPU */
 817
 818 static ssize_t cpu_polarization_show(struct sys_device *dev,
 819                                      struct sysdev_attribute *attr, char *buf)
 820 {
 821         int cpu = dev->id;
 822         ssize_t count;
 823
 824         mutex_lock(&smp_cpu_state_mutex);
 825         switch (smp_cpu_polarization[cpu]) {
 826         case POLARIZATION_HRZ:
 827                 count = sprintf(buf, "horizontal\n");
 828                 break;
 829         case POLARIZATION_VL:
 830                 count = sprintf(buf, "vertical:low\n");
 831                 break;
 832         case POLARIZATION_VM:
 833                 count = sprintf(buf, "vertical:medium\n");
 834                 break;
 835         case POLARIZATION_VH:
 836                 count = sprintf(buf, "vertical:high\n");
 837                 break;
 838         default:
 839                 count = sprintf(buf, "unknown\n");
 840                 break;
 841         }
 842         mutex_unlock(&smp_cpu_state_mutex);
 843         return count;
 844 }
 845 static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL);
 846
 847 static ssize_t show_cpu_address(struct sys_device *dev,
 848                                 struct sysdev_attribute *attr, char *buf)
 849 {
 850         return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
 851 }
 852 static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
 853
 854
 855 static struct attribute *cpu_common_attrs[] = {
 856 #ifdef CONFIG_HOTPLUG_CPU
 857         &attr_configure.attr,
 858 #endif
 859         &attr_address.attr,
 860         &attr_polarization.attr,
 861         NULL,
 862 };
 863
 864 static struct attribute_group cpu_common_attr_group = {
 865         .attrs = cpu_common_attrs,
 866 };
 867
 868 static ssize_t show_capability(struct sys_device *dev,
 869                                 struct sysdev_attribute *attr, char *buf)
 870 {
 871         unsigned int capability;
 872         int rc;
 873
 874         rc = get_cpu_capability(&capability);
 875         if (rc)
 876                 return rc;
 877         return sprintf(buf, "%u\n", capability);
 878 }
 879 static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
 880
 881 static ssize_t show_idle_count(struct sys_device *dev,
 882                                 struct sysdev_attribute *attr, char *buf)
 883 {
 884         struct s390_idle_data *idle;
 885         unsigned long long idle_count;
 886         unsigned int sequence;
 887
 888         idle = &per_cpu(s390_idle, dev->id);
 889 repeat:
 890         sequence = idle->sequence;
 891         smp_rmb();
 892         if (sequence & 1)
 893                 goto repeat;
 894         idle_count = idle->idle_count;
 895         if (idle->idle_enter)
 896                 idle_count++;
 897         smp_rmb();
 898         if (idle->sequence != sequence)
 899                 goto repeat;
 900         return sprintf(buf, "%llu\n", idle_count);
 901 }
 902 static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL);
 903
 904 static ssize_t show_idle_time(struct sys_device *dev,
 905                                 struct sysdev_attribute *attr, char *buf)
 906 {
 907         struct s390_idle_data *idle;
 908         unsigned long long now, idle_time, idle_enter;
 909         unsigned int sequence;
 910
 911         idle = &per_cpu(s390_idle, dev->id);
 912         now = get_clock();
 913 repeat:
 914         sequence = idle->sequence;
 915         smp_rmb();
 916         if (sequence & 1)
 917                 goto repeat;
 918         idle_time = idle->idle_time;
 919         idle_enter = idle->idle_enter;
 920         if (idle_enter != 0ULL && idle_enter < now)
 921                 idle_time += now - idle_enter;
 922         smp_rmb();
 923         if (idle->sequence != sequence)
 924                 goto repeat;
 925         return sprintf(buf, "%llu\n", idle_time >> 12);
 926 }
 927 static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
 928
 929 static struct attribute *cpu_online_attrs[] = {
 930         &attr_capability.attr,
 931         &attr_idle_count.attr,
 932         &attr_idle_time_us.attr,
 933         NULL,
 934 };
 935
 936 static struct attribute_group cpu_online_attr_group = {
 937         .attrs = cpu_online_attrs,
 938 };
 939
 940 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
 941                                     unsigned long action, void *hcpu)
 942 {
 943         unsigned int cpu = (unsigned int)(long)hcpu;
 944         struct cpu *c = &per_cpu(cpu_devices, cpu);
 945         struct sys_device *s = &c->sysdev;
 946         struct s390_idle_data *idle;
 947         int err = 0;
 948
 949         switch (action) {
 950         case CPU_ONLINE:
 951         case CPU_ONLINE_FROZEN:
 952                 idle = &per_cpu(s390_idle, cpu);
 953                 memset(idle, 0, sizeof(struct s390_idle_data));
 954                 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
 955                 break;
 956         case CPU_DEAD:
 957         case CPU_DEAD_FROZEN:
 958                 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
 959                 break;
 960         }
 961         return notifier_from_errno(err);
 962 }
 963
 964 static struct notifier_block __cpuinitdata smp_cpu_nb = {
 965         .notifier_call = smp_cpu_notify,
 966 };
 967
 968 static int __devinit smp_add_present_cpu(int cpu)
 969 {
 970         struct cpu *c = &per_cpu(cpu_devices, cpu);
 971         struct sys_device *s = &c->sysdev;
 972         int rc;
 973
 974         c->hotpluggable = 1;
 975         rc = register_cpu(c, cpu);
 976         if (rc)
 977                 goto out;
 978         rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
 979         if (rc)
 980                 goto out_cpu;
 981         if (!cpu_online(cpu))
 982                 goto out;
 983         rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
 984         if (!rc)
 985                 return 0;
 986         sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
 987 out_cpu:
 988 #ifdef CONFIG_HOTPLUG_CPU
 989         unregister_cpu(c);
 990 #endif
 991 out:
 992         return rc;
 993 }
 994
 995 #ifdef CONFIG_HOTPLUG_CPU
 996
 997 int __ref smp_rescan_cpus(void)
 998 {
 999         cpumask_t newcpus;
1000         int cpu;
1001         int rc;
1002
1003         get_online_cpus();
1004         mutex_lock(&smp_cpu_state_mutex);
1005         newcpus = cpu_present_map;
1006         rc = __smp_rescan_cpus();
1007         if (rc)
1008                 goto out;
1009         cpus_andnot(newcpus, cpu_present_map, newcpus);
1010         for_each_cpu_mask(cpu, newcpus) {
1011                 rc = smp_add_present_cpu(cpu);
1012                 if (rc)
1013                         cpu_clear(cpu, cpu_present_map);
1014         }
1015         rc = 0;
1016 out:
1017         mutex_unlock(&smp_cpu_state_mutex);
1018         put_online_cpus();
1019         if (!cpus_empty(newcpus))
1020                 topology_schedule_update();
1021         return rc;
1022 }
1023
1024 static ssize_t __ref rescan_store(struct sysdev_class *class,
1025                                   struct sysdev_class_attribute *attr,
1026                                   const char *buf,
1027                                   size_t count)
1028 {
1029         int rc;
1030
1031         rc = smp_rescan_cpus();
1032         return rc ? rc : count;
1033 }
1034 static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store);
1035 #endif /* CONFIG_HOTPLUG_CPU */
1036
1037 static ssize_t dispatching_show(struct sysdev_class *class,
1038                                 struct sysdev_class_attribute *attr,
1039                                 char *buf)
1040 {
1041         ssize_t count;
1042
1043         mutex_lock(&smp_cpu_state_mutex);
1044         count = sprintf(buf, "%d\n", cpu_management);
1045         mutex_unlock(&smp_cpu_state_mutex);
1046         return count;
1047 }
1048
1049 static ssize_t dispatching_store(struct sysdev_class *dev,
1050                                  struct sysdev_class_attribute *attr,
1051                                  const char *buf,
1052                                  size_t count)
1053 {
1054         int val, rc;
1055         char delim;
1056
1057         if (sscanf(buf, "%d %c", &val, &delim) != 1)
1058                 return -EINVAL;
1059         if (val != 0 && val != 1)
1060                 return -EINVAL;
1061         rc = 0;
1062         get_online_cpus();
1063         mutex_lock(&smp_cpu_state_mutex);
1064         if (cpu_management == val)
1065                 goto out;
1066         rc = topology_set_cpu_management(val);
1067         if (!rc)
1068                 cpu_management = val;
1069 out:
1070         mutex_unlock(&smp_cpu_state_mutex);
1071         put_online_cpus();
1072         return rc ? rc : count;
1073 }
1074 static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
1075                          dispatching_store);
1076
1077 static int __init topology_init(void)
1078 {
1079         int cpu;
1080         int rc;
1081
1082         register_cpu_notifier(&smp_cpu_nb);
1083
1084 #ifdef CONFIG_HOTPLUG_CPU
1085         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan);
1086         if (rc)
1087                 return rc;
1088 #endif
1089         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching);
1090         if (rc)
1091                 return rc;
1092         for_each_present_cpu(cpu) {
1093                 rc = smp_add_present_cpu(cpu);
1094                 if (rc)
1095                         return rc;
1096         }
1097         return 0;
1098 }
1099 subsys_initcall(topology_init);