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 <asm/ipl.h>
  40 #include <asm/setup.h>
  41 #include <asm/sigp.h>
  42 #include <asm/pgalloc.h>
  43 #include <asm/irq.h>
  44 #include <asm/s390_ext.h>
  45 #include <asm/cpcmd.h>
  46 #include <asm/tlbflush.h>
  47 #include <asm/timer.h>
  48 #include <asm/lowcore.h>
  49 #include <asm/sclp.h>
  50 #include <asm/cputime.h>
  51 #include <asm/vdso.h>
  52 #include <asm/cpu.h>
  53 #include "entry.h"
  54
  55 static struct task_struct *current_set[NR_CPUS];
  56
  57 static u8 smp_cpu_type;
  58 static int smp_use_sigp_detection;
  59
  60 enum s390_cpu_state {
  61         CPU_STATE_STANDBY,
  62         CPU_STATE_CONFIGURED,
  63 };
  64
  65 DEFINE_MUTEX(smp_cpu_state_mutex);
  66 int smp_cpu_polarization[NR_CPUS];
  67 static int smp_cpu_state[NR_CPUS];
  68 static int cpu_management;
  69
  70 static DEFINE_PER_CPU(struct cpu, cpu_devices);
  71
  72 static void smp_ext_bitcall(int, ec_bit_sig);
  73
  74 static int cpu_stopped(int cpu)
  75 {
  76         __u32 status;
  77
  78         switch (signal_processor_ps(&status, 0, cpu, sigp_sense)) {
  79         case sigp_status_stored:
  80                 /* Check for stopped and check stop state */
  81                 if (status & 0x50)
  82                         return 1;
  83                 break;
  84         default:
  85                 break;
  86         }
  87         return 0;
  88 }
  89
  90 void smp_send_stop(void)
  91 {
  92         int cpu, rc;
  93
  94         /* Disable all interrupts/machine checks */
  95         __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
  96         trace_hardirqs_off();
  97
  98         /* stop all processors */
  99         for_each_online_cpu(cpu) {
 100                 if (cpu == smp_processor_id())
 101                         continue;
 102                 do {
 103                         rc = signal_processor(cpu, sigp_stop);
 104                 } while (rc == sigp_busy);
 105
 106                 while (!cpu_stopped(cpu))
 107                         cpu_relax();
 108         }
 109 }
 110
 111 /*
 112  * This is the main routine where commands issued by other
 113  * cpus are handled.
 114  */
 115
 116 static void do_ext_call_interrupt(__u16 code)
 117 {
 118         unsigned long bits;
 119
 120         /*
 121          * handle bit signal external calls
 122          *
 123          * For the ec_schedule signal we have to do nothing. All the work
 124          * is done automatically when we return from the interrupt.
 125          */
 126         bits = xchg(&S390_lowcore.ext_call_fast, 0);
 127
 128         if (test_bit(ec_call_function, &bits))
 129                 generic_smp_call_function_interrupt();
 130
 131         if (test_bit(ec_call_function_single, &bits))
 132                 generic_smp_call_function_single_interrupt();
 133 }
 134
 135 /*
 136  * Send an external call sigp to another cpu and return without waiting
 137  * for its completion.
 138  */
 139 static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
 140 {
 141         /*
 142          * Set signaling bit in lowcore of target cpu and kick it
 143          */
 144         set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
 145         while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
 146                 udelay(10);
 147 }
 148
 149 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 150 {
 151         int cpu;
 152
 153         for_each_cpu(cpu, mask)
 154                 smp_ext_bitcall(cpu, ec_call_function);
 155 }
 156
 157 void arch_send_call_function_single_ipi(int cpu)
 158 {
 159         smp_ext_bitcall(cpu, ec_call_function_single);
 160 }
 161
 162 #ifndef CONFIG_64BIT
 163 /*
 164  * this function sends a 'purge tlb' signal to another CPU.
 165  */
 166 static void smp_ptlb_callback(void *info)
 167 {
 168         __tlb_flush_local();
 169 }
 170
 171 void smp_ptlb_all(void)
 172 {
 173         on_each_cpu(smp_ptlb_callback, NULL, 1);
 174 }
 175 EXPORT_SYMBOL(smp_ptlb_all);
 176 #endif /* ! CONFIG_64BIT */
 177
 178 /*
 179  * this function sends a 'reschedule' IPI to another CPU.
 180  * it goes straight through and wastes no time serializing
 181  * anything. Worst case is that we lose a reschedule ...
 182  */
 183 void smp_send_reschedule(int cpu)
 184 {
 185         smp_ext_bitcall(cpu, ec_schedule);
 186 }
 187
 188 /*
 189  * parameter area for the set/clear control bit callbacks
 190  */
 191 struct ec_creg_mask_parms {
 192         unsigned long orvals[16];
 193         unsigned long andvals[16];
 194 };
 195
 196 /*
 197  * callback for setting/clearing control bits
 198  */
 199 static void smp_ctl_bit_callback(void *info)
 200 {
 201         struct ec_creg_mask_parms *pp = info;
 202         unsigned long cregs[16];
 203         int i;
 204
 205         __ctl_store(cregs, 0, 15);
 206         for (i = 0; i <= 15; i++)
 207                 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
 208         __ctl_load(cregs, 0, 15);
 209 }
 210
 211 /*
 212  * Set a bit in a control register of all cpus
 213  */
 214 void smp_ctl_set_bit(int cr, int bit)
 215 {
 216         struct ec_creg_mask_parms parms;
 217
 218         memset(&parms.orvals, 0, sizeof(parms.orvals));
 219         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
 220         parms.orvals[cr] = 1 << bit;
 221         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 222 }
 223 EXPORT_SYMBOL(smp_ctl_set_bit);
 224
 225 /*
 226  * Clear a bit in a control register of all cpus
 227  */
 228 void smp_ctl_clear_bit(int cr, int bit)
 229 {
 230         struct ec_creg_mask_parms parms;
 231
 232         memset(&parms.orvals, 0, sizeof(parms.orvals));
 233         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
 234         parms.andvals[cr] = ~(1L << bit);
 235         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 236 }
 237 EXPORT_SYMBOL(smp_ctl_clear_bit);
 238
 239 /*
 240  * In early ipl state a temp. logically cpu number is needed, so the sigp
 241  * functions can be used to sense other cpus. Since NR_CPUS is >= 2 on
 242  * CONFIG_SMP and the ipl cpu is logical cpu 0, it must be 1.
 243  */
 244 #define CPU_INIT_NO     1
 245
 246 #ifdef CONFIG_ZFCPDUMP
 247
 248 /*
 249  * zfcpdump_prefix_array holds prefix registers for the following scenario:
 250  * 64 bit zfcpdump kernel and 31 bit kernel which is to be dumped. We have to
 251  * save its prefix registers, since they get lost, when switching from 31 bit
 252  * to 64 bit.
 253  */
 254 unsigned int zfcpdump_prefix_array[NR_CPUS + 1] \
 255         __attribute__((__section__(".data")));
 256
 257 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
 258 {
 259         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
 260                 return;
 261         if (cpu >= NR_CPUS) {
 262                 pr_warning("CPU %i exceeds the maximum %i and is excluded from "
 263                            "the dump\n", cpu, NR_CPUS - 1);
 264                 return;
 265         }
 266         zfcpdump_save_areas[cpu] = kmalloc(sizeof(union save_area), GFP_KERNEL);
 267         __cpu_logical_map[CPU_INIT_NO] = (__u16) phy_cpu;
 268         while (signal_processor(CPU_INIT_NO, sigp_stop_and_store_status) ==
 269                sigp_busy)
 270                 cpu_relax();
 271         memcpy(zfcpdump_save_areas[cpu],
 272                (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
 273                SAVE_AREA_SIZE);
 274 #ifdef CONFIG_64BIT
 275         /* copy original prefix register */
 276         zfcpdump_save_areas[cpu]->s390x.pref_reg = zfcpdump_prefix_array[cpu];
 277 #endif
 278 }
 279
 280 union save_area *zfcpdump_save_areas[NR_CPUS + 1];
 281 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
 282
 283 #else
 284
 285 static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
 286
 287 #endif /* CONFIG_ZFCPDUMP */
 288
 289 static int cpu_known(int cpu_id)
 290 {
 291         int cpu;
 292
 293         for_each_present_cpu(cpu) {
 294                 if (__cpu_logical_map[cpu] == cpu_id)
 295                         return 1;
 296         }
 297         return 0;
 298 }
 299
 300 static int smp_rescan_cpus_sigp(cpumask_t avail)
 301 {
 302         int cpu_id, logical_cpu;
 303
 304         logical_cpu = cpumask_first(&avail);
 305         if (logical_cpu >= nr_cpu_ids)
 306                 return 0;
 307         for (cpu_id = 0; cpu_id <= MAX_CPU_ADDRESS; cpu_id++) {
 308                 if (cpu_known(cpu_id))
 309                         continue;
 310                 __cpu_logical_map[logical_cpu] = cpu_id;
 311                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
 312                 if (!cpu_stopped(logical_cpu))
 313                         continue;
 314                 cpu_set(logical_cpu, cpu_present_map);
 315                 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
 316                 logical_cpu = cpumask_next(logical_cpu, &avail);
 317                 if (logical_cpu >= nr_cpu_ids)
 318                         break;
 319         }
 320         return 0;
 321 }
 322
 323 static int smp_rescan_cpus_sclp(cpumask_t avail)
 324 {
 325         struct sclp_cpu_info *info;
 326         int cpu_id, logical_cpu, cpu;
 327         int rc;
 328
 329         logical_cpu = cpumask_first(&avail);
 330         if (logical_cpu >= nr_cpu_ids)
 331                 return 0;
 332         info = kmalloc(sizeof(*info), GFP_KERNEL);
 333         if (!info)
 334                 return -ENOMEM;
 335         rc = sclp_get_cpu_info(info);
 336         if (rc)
 337                 goto out;
 338         for (cpu = 0; cpu < info->combined; cpu++) {
 339                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
 340                         continue;
 341                 cpu_id = info->cpu[cpu].address;
 342                 if (cpu_known(cpu_id))
 343                         continue;
 344                 __cpu_logical_map[logical_cpu] = cpu_id;
 345                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
 346                 cpu_set(logical_cpu, cpu_present_map);
 347                 if (cpu >= info->configured)
 348                         smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
 349                 else
 350                         smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
 351                 logical_cpu = cpumask_next(logical_cpu, &avail);
 352                 if (logical_cpu >= nr_cpu_ids)
 353                         break;
 354         }
 355 out:
 356         kfree(info);
 357         return rc;
 358 }
 359
 360 static int __smp_rescan_cpus(void)
 361 {
 362         cpumask_t avail;
 363
 364         cpus_xor(avail, cpu_possible_map, cpu_present_map);
 365         if (smp_use_sigp_detection)
 366                 return smp_rescan_cpus_sigp(avail);
 367         else
 368                 return smp_rescan_cpus_sclp(avail);
 369 }
 370
 371 static void __init smp_detect_cpus(void)
 372 {
 373         unsigned int cpu, c_cpus, s_cpus;
 374         struct sclp_cpu_info *info;
 375         u16 boot_cpu_addr, cpu_addr;
 376
 377         c_cpus = 1;
 378         s_cpus = 0;
 379         boot_cpu_addr = __cpu_logical_map[0];
 380         info = kmalloc(sizeof(*info), GFP_KERNEL);
 381         if (!info)
 382                 panic("smp_detect_cpus failed to allocate memory\n");
 383         /* Use sigp detection algorithm if sclp doesn't work. */
 384         if (sclp_get_cpu_info(info)) {
 385                 smp_use_sigp_detection = 1;
 386                 for (cpu = 0; cpu <= MAX_CPU_ADDRESS; cpu++) {
 387                         if (cpu == boot_cpu_addr)
 388                                 continue;
 389                         __cpu_logical_map[CPU_INIT_NO] = cpu;
 390                         if (!cpu_stopped(CPU_INIT_NO))
 391                                 continue;
 392                         smp_get_save_area(c_cpus, cpu);
 393                         c_cpus++;
 394                 }
 395                 goto out;
 396         }
 397
 398         if (info->has_cpu_type) {
 399                 for (cpu = 0; cpu < info->combined; cpu++) {
 400                         if (info->cpu[cpu].address == boot_cpu_addr) {
 401                                 smp_cpu_type = info->cpu[cpu].type;
 402                                 break;
 403                         }
 404                 }
 405         }
 406
 407         for (cpu = 0; cpu < info->combined; cpu++) {
 408                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
 409                         continue;
 410                 cpu_addr = info->cpu[cpu].address;
 411                 if (cpu_addr == boot_cpu_addr)
 412                         continue;
 413                 __cpu_logical_map[CPU_INIT_NO] = cpu_addr;
 414                 if (!cpu_stopped(CPU_INIT_NO)) {
 415                         s_cpus++;
 416                         continue;
 417                 }
 418                 smp_get_save_area(c_cpus, cpu_addr);
 419                 c_cpus++;
 420         }
 421 out:
 422         kfree(info);
 423         pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
 424         get_online_cpus();
 425         __smp_rescan_cpus();
 426         put_online_cpus();
 427 }
 428
 429 /*
 430  *      Activate a secondary processor.
 431  */
 432 int __cpuinit start_secondary(void *cpuvoid)
 433 {
 434         /* Setup the cpu */
 435         cpu_init();
 436         preempt_disable();
 437         /* Enable TOD clock interrupts on the secondary cpu. */
 438         init_cpu_timer();
 439         /* Enable cpu timer interrupts on the secondary cpu. */
 440         init_cpu_vtimer();
 441         /* Enable pfault pseudo page faults on this cpu. */
 442         pfault_init();
 443
 444         /* call cpu notifiers */
 445         notify_cpu_starting(smp_processor_id());
 446         /* Mark this cpu as online */
 447         ipi_call_lock();
 448         cpu_set(smp_processor_id(), cpu_online_map);
 449         ipi_call_unlock();
 450         /* Switch on interrupts */
 451         local_irq_enable();
 452         /* Print info about this processor */
 453         print_cpu_info();
 454         /* cpu_idle will call schedule for us */
 455         cpu_idle();
 456         return 0;
 457 }
 458
 459 static void __init smp_create_idle(unsigned int cpu)
 460 {
 461         struct task_struct *p;
 462
 463         /*
 464          *  don't care about the psw and regs settings since we'll never
 465          *  reschedule the forked task.
 466          */
 467         p = fork_idle(cpu);
 468         if (IS_ERR(p))
 469                 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
 470         current_set[cpu] = p;
 471 }
 472
 473 static int __cpuinit smp_alloc_lowcore(int cpu)
 474 {
 475         unsigned long async_stack, panic_stack;
 476         struct _lowcore *lowcore;
 477
 478         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
 479         if (!lowcore)
 480                 return -ENOMEM;
 481         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
 482         panic_stack = __get_free_page(GFP_KERNEL);
 483         if (!panic_stack || !async_stack)
 484                 goto out;
 485         memcpy(lowcore, &S390_lowcore, 512);
 486         memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
 487         lowcore->async_stack = async_stack + ASYNC_SIZE;
 488         lowcore->panic_stack = panic_stack + PAGE_SIZE;
 489
 490 #ifndef CONFIG_64BIT
 491         if (MACHINE_HAS_IEEE) {
 492                 unsigned long save_area;
 493
 494                 save_area = get_zeroed_page(GFP_KERNEL);
 495                 if (!save_area)
 496                         goto out;
 497                 lowcore->extended_save_area_addr = (u32) save_area;
 498         }
 499 #else
 500         if (vdso_alloc_per_cpu(cpu, lowcore))
 501                 goto out;
 502 #endif
 503         lowcore_ptr[cpu] = lowcore;
 504         return 0;
 505
 506 out:
 507         free_page(panic_stack);
 508         free_pages(async_stack, ASYNC_ORDER);
 509         free_pages((unsigned long) lowcore, LC_ORDER);
 510         return -ENOMEM;
 511 }
 512
 513 static void smp_free_lowcore(int cpu)
 514 {
 515         struct _lowcore *lowcore;
 516
 517         lowcore = lowcore_ptr[cpu];
 518 #ifndef CONFIG_64BIT
 519         if (MACHINE_HAS_IEEE)
 520                 free_page((unsigned long) lowcore->extended_save_area_addr);
 521 #else
 522         vdso_free_per_cpu(cpu, lowcore);
 523 #endif
 524         free_page(lowcore->panic_stack - PAGE_SIZE);
 525         free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
 526         free_pages((unsigned long) lowcore, LC_ORDER);
 527         lowcore_ptr[cpu] = NULL;
 528 }
 529
 530 /* Upping and downing of CPUs */
 531 int __cpuinit __cpu_up(unsigned int cpu)
 532 {
 533         struct task_struct *idle;
 534         struct _lowcore *cpu_lowcore;
 535         struct stack_frame *sf;
 536         sigp_ccode ccode;
 537         u32 lowcore;
 538
 539         if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
 540                 return -EIO;
 541         if (smp_alloc_lowcore(cpu))
 542                 return -ENOMEM;
 543         do {
 544                 ccode = signal_processor(cpu, sigp_initial_cpu_reset);
 545                 if (ccode == sigp_busy)
 546                         udelay(10);
 547                 if (ccode == sigp_not_operational)
 548                         goto err_out;
 549         } while (ccode == sigp_busy);
 550
 551         lowcore = (u32)(unsigned long)lowcore_ptr[cpu];
 552         while (signal_processor_p(lowcore, cpu, sigp_set_prefix) == sigp_busy)
 553                 udelay(10);
 554
 555         idle = current_set[cpu];
 556         cpu_lowcore = lowcore_ptr[cpu];
 557         cpu_lowcore->kernel_stack = (unsigned long)
 558                 task_stack_page(idle) + THREAD_SIZE;
 559         cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
 560         sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
 561                                      - sizeof(struct pt_regs)
 562                                      - sizeof(struct stack_frame));
 563         memset(sf, 0, sizeof(struct stack_frame));
 564         sf->gprs[9] = (unsigned long) sf;
 565         cpu_lowcore->save_area[15] = (unsigned long) sf;
 566         __ctl_store(cpu_lowcore->cregs_save_area, 0, 15);
 567         asm volatile(
 568                 "       stam    0,15,0(%0)"
 569                 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
 570         cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
 571         cpu_lowcore->current_task = (unsigned long) idle;
 572         cpu_lowcore->cpu_nr = cpu;
 573         cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
 574         cpu_lowcore->machine_flags = S390_lowcore.machine_flags;
 575         cpu_lowcore->ftrace_func = S390_lowcore.ftrace_func;
 576         eieio();
 577
 578         while (signal_processor(cpu, sigp_restart) == sigp_busy)
 579                 udelay(10);
 580
 581         while (!cpu_online(cpu))
 582                 cpu_relax();
 583         return 0;
 584
 585 err_out:
 586         smp_free_lowcore(cpu);
 587         return -EIO;
 588 }
 589
 590 static int __init setup_possible_cpus(char *s)
 591 {
 592         int pcpus, cpu;
 593
 594         pcpus = simple_strtoul(s, NULL, 0);
 595         init_cpu_possible(cpumask_of(0));
 596         for (cpu = 1; cpu < pcpus && cpu < nr_cpu_ids; cpu++)
 597                 set_cpu_possible(cpu, true);
 598         return 0;
 599 }
 600 early_param("possible_cpus", setup_possible_cpus);
 601
 602 #ifdef CONFIG_HOTPLUG_CPU
 603
 604 int __cpu_disable(void)
 605 {
 606         struct ec_creg_mask_parms cr_parms;
 607         int cpu = smp_processor_id();
 608
 609         cpu_clear(cpu, cpu_online_map);
 610
 611         /* Disable pfault pseudo page faults on this cpu. */
 612         pfault_fini();
 613
 614         memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
 615         memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
 616
 617         /* disable all external interrupts */
 618         cr_parms.orvals[0] = 0;
 619         cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 12 |
 620                                 1 << 11 | 1 << 10 | 1 <<  6 | 1 <<  4);
 621         /* disable all I/O interrupts */
 622         cr_parms.orvals[6] = 0;
 623         cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
 624                                 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
 625         /* disable most machine checks */
 626         cr_parms.orvals[14] = 0;
 627         cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
 628                                  1 << 25 | 1 << 24);
 629
 630         smp_ctl_bit_callback(&cr_parms);
 631
 632         return 0;
 633 }
 634
 635 void __cpu_die(unsigned int cpu)
 636 {
 637         /* Wait until target cpu is down */
 638         while (!cpu_stopped(cpu))
 639                 cpu_relax();
 640         while (signal_processor_p(0, cpu, sigp_set_prefix) == sigp_busy)
 641                 udelay(10);
 642         smp_free_lowcore(cpu);
 643         pr_info("Processor %d stopped\n", cpu);
 644 }
 645
 646 void cpu_die(void)
 647 {
 648         idle_task_exit();
 649         while (signal_processor(smp_processor_id(), sigp_stop) == sigp_busy)
 650                 cpu_relax();
 651         for (;;);
 652 }
 653
 654 #endif /* CONFIG_HOTPLUG_CPU */
 655
 656 void __init smp_prepare_cpus(unsigned int max_cpus)
 657 {
 658 #ifndef CONFIG_64BIT
 659         unsigned long save_area = 0;
 660 #endif
 661         unsigned long async_stack, panic_stack;
 662         struct _lowcore *lowcore;
 663         unsigned int cpu;
 664
 665         smp_detect_cpus();
 666
 667         /* request the 0x1201 emergency signal external interrupt */
 668         if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
 669                 panic("Couldn't request external interrupt 0x1201");
 670         print_cpu_info();
 671
 672         /* Reallocate current lowcore, but keep its contents. */
 673         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
 674         panic_stack = __get_free_page(GFP_KERNEL);
 675         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
 676         BUG_ON(!lowcore || !panic_stack || !async_stack);
 677 #ifndef CONFIG_64BIT
 678         if (MACHINE_HAS_IEEE)
 679                 save_area = get_zeroed_page(GFP_KERNEL);
 680 #endif
 681         local_irq_disable();
 682         local_mcck_disable();
 683         lowcore_ptr[smp_processor_id()] = lowcore;
 684         *lowcore = S390_lowcore;
 685         lowcore->panic_stack = panic_stack + PAGE_SIZE;
 686         lowcore->async_stack = async_stack + ASYNC_SIZE;
 687 #ifndef CONFIG_64BIT
 688         if (MACHINE_HAS_IEEE)
 689                 lowcore->extended_save_area_addr = (u32) save_area;
 690 #endif
 691         set_prefix((u32)(unsigned long) lowcore);
 692         local_mcck_enable();
 693         local_irq_enable();
 694 #ifdef CONFIG_64BIT
 695         if (vdso_alloc_per_cpu(smp_processor_id(), &S390_lowcore))
 696                 BUG();
 697 #endif
 698         for_each_possible_cpu(cpu)
 699                 if (cpu != smp_processor_id())
 700                         smp_create_idle(cpu);
 701 }
 702
 703 void __init smp_prepare_boot_cpu(void)
 704 {
 705         BUG_ON(smp_processor_id() != 0);
 706
 707         current_thread_info()->cpu = 0;
 708         cpu_set(0, cpu_present_map);
 709         cpu_set(0, cpu_online_map);
 710         S390_lowcore.percpu_offset = __per_cpu_offset[0];
 711         current_set[0] = current;
 712         smp_cpu_state[0] = CPU_STATE_CONFIGURED;
 713         smp_cpu_polarization[0] = POLARIZATION_UNKNWN;
 714 }
 715
 716 void __init smp_cpus_done(unsigned int max_cpus)
 717 {
 718 }
 719
 720 void __init smp_setup_processor_id(void)
 721 {
 722         S390_lowcore.cpu_nr = 0;
 723         __cpu_logical_map[0] = stap();
 724 }
 725
 726 /*
 727  * the frequency of the profiling timer can be changed
 728  * by writing a multiplier value into /proc/profile.
 729  *
 730  * usually you want to run this on all CPUs ;)
 731  */
 732 int setup_profiling_timer(unsigned int multiplier)
 733 {
 734         return 0;
 735 }
 736
 737 #ifdef CONFIG_HOTPLUG_CPU
 738 static ssize_t cpu_configure_show(struct sys_device *dev,
 739                                 struct sysdev_attribute *attr, char *buf)
 740 {
 741         ssize_t count;
 742
 743         mutex_lock(&smp_cpu_state_mutex);
 744         count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
 745         mutex_unlock(&smp_cpu_state_mutex);
 746         return count;
 747 }
 748
 749 static ssize_t cpu_configure_store(struct sys_device *dev,
 750                                   struct sysdev_attribute *attr,
 751                                   const char *buf, size_t count)
 752 {
 753         int cpu = dev->id;
 754         int val, rc;
 755         char delim;
 756
 757         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 758                 return -EINVAL;
 759         if (val != 0 && val != 1)
 760                 return -EINVAL;
 761
 762         get_online_cpus();
 763         mutex_lock(&smp_cpu_state_mutex);
 764         rc = -EBUSY;
 765         if (cpu_online(cpu))
 766                 goto out;
 767         rc = 0;
 768         switch (val) {
 769         case 0:
 770                 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
 771                         rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
 772                         if (!rc) {
 773                                 smp_cpu_state[cpu] = CPU_STATE_STANDBY;
 774                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 775                         }
 776                 }
 777                 break;
 778         case 1:
 779                 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
 780                         rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
 781                         if (!rc) {
 782                                 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
 783                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 784                         }
 785                 }
 786                 break;
 787         default:
 788                 break;
 789         }
 790 out:
 791         mutex_unlock(&smp_cpu_state_mutex);
 792         put_online_cpus();
 793         return rc ? rc : count;
 794 }
 795 static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
 796 #endif /* CONFIG_HOTPLUG_CPU */
 797
 798 static ssize_t cpu_polarization_show(struct sys_device *dev,
 799                                      struct sysdev_attribute *attr, char *buf)
 800 {
 801         int cpu = dev->id;
 802         ssize_t count;
 803
 804         mutex_lock(&smp_cpu_state_mutex);
 805         switch (smp_cpu_polarization[cpu]) {
 806         case POLARIZATION_HRZ:
 807                 count = sprintf(buf, "horizontal\n");
 808                 break;
 809         case POLARIZATION_VL:
 810                 count = sprintf(buf, "vertical:low\n");
 811                 break;
 812         case POLARIZATION_VM:
 813                 count = sprintf(buf, "vertical:medium\n");
 814                 break;
 815         case POLARIZATION_VH:
 816                 count = sprintf(buf, "vertical:high\n");
 817                 break;
 818         default:
 819                 count = sprintf(buf, "unknown\n");
 820                 break;
 821         }
 822         mutex_unlock(&smp_cpu_state_mutex);
 823         return count;
 824 }
 825 static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL);
 826
 827 static ssize_t show_cpu_address(struct sys_device *dev,
 828                                 struct sysdev_attribute *attr, char *buf)
 829 {
 830         return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
 831 }
 832 static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
 833
 834
 835 static struct attribute *cpu_common_attrs[] = {
 836 #ifdef CONFIG_HOTPLUG_CPU
 837         &attr_configure.attr,
 838 #endif
 839         &attr_address.attr,
 840         &attr_polarization.attr,
 841         NULL,
 842 };
 843
 844 static struct attribute_group cpu_common_attr_group = {
 845         .attrs = cpu_common_attrs,
 846 };
 847
 848 static ssize_t show_capability(struct sys_device *dev,
 849                                 struct sysdev_attribute *attr, char *buf)
 850 {
 851         unsigned int capability;
 852         int rc;
 853
 854         rc = get_cpu_capability(&capability);
 855         if (rc)
 856                 return rc;
 857         return sprintf(buf, "%u\n", capability);
 858 }
 859 static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
 860
 861 static ssize_t show_idle_count(struct sys_device *dev,
 862                                 struct sysdev_attribute *attr, char *buf)
 863 {
 864         struct s390_idle_data *idle;
 865         unsigned long long idle_count;
 866         unsigned int sequence;
 867
 868         idle = &per_cpu(s390_idle, dev->id);
 869 repeat:
 870         sequence = idle->sequence;
 871         smp_rmb();
 872         if (sequence & 1)
 873                 goto repeat;
 874         idle_count = idle->idle_count;
 875         if (idle->idle_enter)
 876                 idle_count++;
 877         smp_rmb();
 878         if (idle->sequence != sequence)
 879                 goto repeat;
 880         return sprintf(buf, "%llu\n", idle_count);
 881 }
 882 static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL);
 883
 884 static ssize_t show_idle_time(struct sys_device *dev,
 885                                 struct sysdev_attribute *attr, char *buf)
 886 {
 887         struct s390_idle_data *idle;
 888         unsigned long long now, idle_time, idle_enter;
 889         unsigned int sequence;
 890
 891         idle = &per_cpu(s390_idle, dev->id);
 892         now = get_clock();
 893 repeat:
 894         sequence = idle->sequence;
 895         smp_rmb();
 896         if (sequence & 1)
 897                 goto repeat;
 898         idle_time = idle->idle_time;
 899         idle_enter = idle->idle_enter;
 900         if (idle_enter != 0ULL && idle_enter < now)
 901                 idle_time += now - idle_enter;
 902         smp_rmb();
 903         if (idle->sequence != sequence)
 904                 goto repeat;
 905         return sprintf(buf, "%llu\n", idle_time >> 12);
 906 }
 907 static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
 908
 909 static struct attribute *cpu_online_attrs[] = {
 910         &attr_capability.attr,
 911         &attr_idle_count.attr,
 912         &attr_idle_time_us.attr,
 913         NULL,
 914 };
 915
 916 static struct attribute_group cpu_online_attr_group = {
 917         .attrs = cpu_online_attrs,
 918 };
 919
 920 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
 921                                     unsigned long action, void *hcpu)
 922 {
 923         unsigned int cpu = (unsigned int)(long)hcpu;
 924         struct cpu *c = &per_cpu(cpu_devices, cpu);
 925         struct sys_device *s = &c->sysdev;
 926         struct s390_idle_data *idle;
 927
 928         switch (action) {
 929         case CPU_ONLINE:
 930         case CPU_ONLINE_FROZEN:
 931                 idle = &per_cpu(s390_idle, cpu);
 932                 memset(idle, 0, sizeof(struct s390_idle_data));
 933                 if (sysfs_create_group(&s->kobj, &cpu_online_attr_group))
 934                         return NOTIFY_BAD;
 935                 break;
 936         case CPU_DEAD:
 937         case CPU_DEAD_FROZEN:
 938                 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
 939                 break;
 940         }
 941         return NOTIFY_OK;
 942 }
 943
 944 static struct notifier_block __cpuinitdata smp_cpu_nb = {
 945         .notifier_call = smp_cpu_notify,
 946 };
 947
 948 static int __devinit smp_add_present_cpu(int cpu)
 949 {
 950         struct cpu *c = &per_cpu(cpu_devices, cpu);
 951         struct sys_device *s = &c->sysdev;
 952         int rc;
 953
 954         c->hotpluggable = 1;
 955         rc = register_cpu(c, cpu);
 956         if (rc)
 957                 goto out;
 958         rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
 959         if (rc)
 960                 goto out_cpu;
 961         if (!cpu_online(cpu))
 962                 goto out;
 963         rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
 964         if (!rc)
 965                 return 0;
 966         sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
 967 out_cpu:
 968 #ifdef CONFIG_HOTPLUG_CPU
 969         unregister_cpu(c);
 970 #endif
 971 out:
 972         return rc;
 973 }
 974
 975 #ifdef CONFIG_HOTPLUG_CPU
 976
 977 int __ref smp_rescan_cpus(void)
 978 {
 979         cpumask_t newcpus;
 980         int cpu;
 981         int rc;
 982
 983         get_online_cpus();
 984         mutex_lock(&smp_cpu_state_mutex);
 985         newcpus = cpu_present_map;
 986         rc = __smp_rescan_cpus();
 987         if (rc)
 988                 goto out;
 989         cpus_andnot(newcpus, cpu_present_map, newcpus);
 990         for_each_cpu_mask(cpu, newcpus) {
 991                 rc = smp_add_present_cpu(cpu);
 992                 if (rc)
 993                         cpu_clear(cpu, cpu_present_map);
 994         }
 995         rc = 0;
 996 out:
 997         mutex_unlock(&smp_cpu_state_mutex);
 998         put_online_cpus();
 999         if (!cpus_empty(newcpus))
1000                 topology_schedule_update();
1001         return rc;
1002 }
1003
1004 static ssize_t __ref rescan_store(struct sysdev_class *class, const char *buf,
1005                                   size_t count)
1006 {
1007         int rc;
1008
1009         rc = smp_rescan_cpus();
1010         return rc ? rc : count;
1011 }
1012 static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store);
1013 #endif /* CONFIG_HOTPLUG_CPU */
1014
1015 static ssize_t dispatching_show(struct sysdev_class *class, char *buf)
1016 {
1017         ssize_t count;
1018
1019         mutex_lock(&smp_cpu_state_mutex);
1020         count = sprintf(buf, "%d\n", cpu_management);
1021         mutex_unlock(&smp_cpu_state_mutex);
1022         return count;
1023 }
1024
1025 static ssize_t dispatching_store(struct sysdev_class *dev, const char *buf,
1026                                  size_t count)
1027 {
1028         int val, rc;
1029         char delim;
1030
1031         if (sscanf(buf, "%d %c", &val, &delim) != 1)
1032                 return -EINVAL;
1033         if (val != 0 && val != 1)
1034                 return -EINVAL;
1035         rc = 0;
1036         get_online_cpus();
1037         mutex_lock(&smp_cpu_state_mutex);
1038         if (cpu_management == val)
1039                 goto out;
1040         rc = topology_set_cpu_management(val);
1041         if (!rc)
1042                 cpu_management = val;
1043 out:
1044         mutex_unlock(&smp_cpu_state_mutex);
1045         put_online_cpus();
1046         return rc ? rc : count;
1047 }
1048 static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
1049                          dispatching_store);
1050
1051 static int __init topology_init(void)
1052 {
1053         int cpu;
1054         int rc;
1055
1056         register_cpu_notifier(&smp_cpu_nb);
1057
1058 #ifdef CONFIG_HOTPLUG_CPU
1059         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan);
1060         if (rc)
1061                 return rc;
1062 #endif
1063         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching);
1064         if (rc)
1065                 return rc;
1066         for_each_present_cpu(cpu) {
1067                 rc = smp_add_present_cpu(cpu);
1068                 if (rc)
1069                         return rc;
1070         }
1071         return 0;
1072 }
1073 subsys_initcall(topology_init);