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 /* logical cpu to cpu address */
  56 int __cpu_logical_map[NR_CPUS];
  57
  58 static struct task_struct *current_set[NR_CPUS];
  59
  60 static u8 smp_cpu_type;
  61 static int smp_use_sigp_detection;
  62
  63 enum s390_cpu_state {
  64         CPU_STATE_STANDBY,
  65         CPU_STATE_CONFIGURED,
  66 };
  67
  68 DEFINE_MUTEX(smp_cpu_state_mutex);
  69 int smp_cpu_polarization[NR_CPUS];
  70 static int smp_cpu_state[NR_CPUS];
  71 static int cpu_management;
  72
  73 static DEFINE_PER_CPU(struct cpu, cpu_devices);
  74
  75 static void smp_ext_bitcall(int, ec_bit_sig);
  76
  77 static int cpu_stopped(int cpu)
  78 {
  79         __u32 status;
  80
  81         switch (signal_processor_ps(&status, 0, cpu, sigp_sense)) {
  82         case sigp_status_stored:
  83                 /* Check for stopped and check stop state */
  84                 if (status & 0x50)
  85                         return 1;
  86                 break;
  87         default:
  88                 break;
  89         }
  90         return 0;
  91 }
  92
  93 void smp_send_stop(void)
  94 {
  95         int cpu, rc;
  96
  97         /* Disable all interrupts/machine checks */
  98         __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
  99         trace_hardirqs_off();
 100
 101         /* stop all processors */
 102         for_each_online_cpu(cpu) {
 103                 if (cpu == smp_processor_id())
 104                         continue;
 105                 do {
 106                         rc = signal_processor(cpu, sigp_stop);
 107                 } while (rc == sigp_busy);
 108
 109                 while (!cpu_stopped(cpu))
 110                         cpu_relax();
 111         }
 112 }
 113
 114 /*
 115  * This is the main routine where commands issued by other
 116  * cpus are handled.
 117  */
 118
 119 static void do_ext_call_interrupt(__u16 code)
 120 {
 121         unsigned long bits;
 122
 123         /*
 124          * handle bit signal external calls
 125          *
 126          * For the ec_schedule signal we have to do nothing. All the work
 127          * is done automatically when we return from the interrupt.
 128          */
 129         bits = xchg(&S390_lowcore.ext_call_fast, 0);
 130
 131         if (test_bit(ec_call_function, &bits))
 132                 generic_smp_call_function_interrupt();
 133
 134         if (test_bit(ec_call_function_single, &bits))
 135                 generic_smp_call_function_single_interrupt();
 136 }
 137
 138 /*
 139  * Send an external call sigp to another cpu and return without waiting
 140  * for its completion.
 141  */
 142 static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
 143 {
 144         /*
 145          * Set signaling bit in lowcore of target cpu and kick it
 146          */
 147         set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
 148         while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
 149                 udelay(10);
 150 }
 151
 152 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 153 {
 154         int cpu;
 155
 156         for_each_cpu(cpu, mask)
 157                 smp_ext_bitcall(cpu, ec_call_function);
 158 }
 159
 160 void arch_send_call_function_single_ipi(int cpu)
 161 {
 162         smp_ext_bitcall(cpu, ec_call_function_single);
 163 }
 164
 165 #ifndef CONFIG_64BIT
 166 /*
 167  * this function sends a 'purge tlb' signal to another CPU.
 168  */
 169 static void smp_ptlb_callback(void *info)
 170 {
 171         __tlb_flush_local();
 172 }
 173
 174 void smp_ptlb_all(void)
 175 {
 176         on_each_cpu(smp_ptlb_callback, NULL, 1);
 177 }
 178 EXPORT_SYMBOL(smp_ptlb_all);
 179 #endif /* ! CONFIG_64BIT */
 180
 181 /*
 182  * this function sends a 'reschedule' IPI to another CPU.
 183  * it goes straight through and wastes no time serializing
 184  * anything. Worst case is that we lose a reschedule ...
 185  */
 186 void smp_send_reschedule(int cpu)
 187 {
 188         smp_ext_bitcall(cpu, ec_schedule);
 189 }
 190
 191 /*
 192  * parameter area for the set/clear control bit callbacks
 193  */
 194 struct ec_creg_mask_parms {
 195         unsigned long orvals[16];
 196         unsigned long andvals[16];
 197 };
 198
 199 /*
 200  * callback for setting/clearing control bits
 201  */
 202 static void smp_ctl_bit_callback(void *info)
 203 {
 204         struct ec_creg_mask_parms *pp = info;
 205         unsigned long cregs[16];
 206         int i;
 207
 208         __ctl_store(cregs, 0, 15);
 209         for (i = 0; i <= 15; i++)
 210                 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
 211         __ctl_load(cregs, 0, 15);
 212 }
 213
 214 /*
 215  * Set a bit in a control register of all cpus
 216  */
 217 void smp_ctl_set_bit(int cr, int bit)
 218 {
 219         struct ec_creg_mask_parms parms;
 220
 221         memset(&parms.orvals, 0, sizeof(parms.orvals));
 222         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
 223         parms.orvals[cr] = 1 << bit;
 224         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 225 }
 226 EXPORT_SYMBOL(smp_ctl_set_bit);
 227
 228 /*
 229  * Clear a bit in a control register of all cpus
 230  */
 231 void smp_ctl_clear_bit(int cr, int bit)
 232 {
 233         struct ec_creg_mask_parms parms;
 234
 235         memset(&parms.orvals, 0, sizeof(parms.orvals));
 236         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
 237         parms.andvals[cr] = ~(1L << bit);
 238         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 239 }
 240 EXPORT_SYMBOL(smp_ctl_clear_bit);
 241
 242 /*
 243  * In early ipl state a temp. logically cpu number is needed, so the sigp
 244  * functions can be used to sense other cpus. Since NR_CPUS is >= 2 on
 245  * CONFIG_SMP and the ipl cpu is logical cpu 0, it must be 1.
 246  */
 247 #define CPU_INIT_NO     1
 248
 249 #ifdef CONFIG_ZFCPDUMP
 250
 251 /*
 252  * zfcpdump_prefix_array holds prefix registers for the following scenario:
 253  * 64 bit zfcpdump kernel and 31 bit kernel which is to be dumped. We have to
 254  * save its prefix registers, since they get lost, when switching from 31 bit
 255  * to 64 bit.
 256  */
 257 unsigned int zfcpdump_prefix_array[NR_CPUS + 1] \
 258         __attribute__((__section__(".data")));
 259
 260 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
 261 {
 262         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
 263                 return;
 264         if (cpu >= NR_CPUS) {
 265                 pr_warning("CPU %i exceeds the maximum %i and is excluded from "
 266                            "the dump\n", cpu, NR_CPUS - 1);
 267                 return;
 268         }
 269         zfcpdump_save_areas[cpu] = kmalloc(sizeof(union save_area), GFP_KERNEL);
 270         __cpu_logical_map[CPU_INIT_NO] = (__u16) phy_cpu;
 271         while (signal_processor(CPU_INIT_NO, sigp_stop_and_store_status) ==
 272                sigp_busy)
 273                 cpu_relax();
 274         memcpy(zfcpdump_save_areas[cpu],
 275                (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
 276                SAVE_AREA_SIZE);
 277 #ifdef CONFIG_64BIT
 278         /* copy original prefix register */
 279         zfcpdump_save_areas[cpu]->s390x.pref_reg = zfcpdump_prefix_array[cpu];
 280 #endif
 281 }
 282
 283 union save_area *zfcpdump_save_areas[NR_CPUS + 1];
 284 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
 285
 286 #else
 287
 288 static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
 289
 290 #endif /* CONFIG_ZFCPDUMP */
 291
 292 static int cpu_known(int cpu_id)
 293 {
 294         int cpu;
 295
 296         for_each_present_cpu(cpu) {
 297                 if (__cpu_logical_map[cpu] == cpu_id)
 298                         return 1;
 299         }
 300         return 0;
 301 }
 302
 303 static int smp_rescan_cpus_sigp(cpumask_t avail)
 304 {
 305         int cpu_id, logical_cpu;
 306
 307         logical_cpu = cpumask_first(&avail);
 308         if (logical_cpu >= nr_cpu_ids)
 309                 return 0;
 310         for (cpu_id = 0; cpu_id <= MAX_CPU_ADDRESS; cpu_id++) {
 311                 if (cpu_known(cpu_id))
 312                         continue;
 313                 __cpu_logical_map[logical_cpu] = cpu_id;
 314                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
 315                 if (!cpu_stopped(logical_cpu))
 316                         continue;
 317                 cpu_set(logical_cpu, cpu_present_map);
 318                 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
 319                 logical_cpu = cpumask_next(logical_cpu, &avail);
 320                 if (logical_cpu >= nr_cpu_ids)
 321                         break;
 322         }
 323         return 0;
 324 }
 325
 326 static int smp_rescan_cpus_sclp(cpumask_t avail)
 327 {
 328         struct sclp_cpu_info *info;
 329         int cpu_id, logical_cpu, cpu;
 330         int rc;
 331
 332         logical_cpu = cpumask_first(&avail);
 333         if (logical_cpu >= nr_cpu_ids)
 334                 return 0;
 335         info = kmalloc(sizeof(*info), GFP_KERNEL);
 336         if (!info)
 337                 return -ENOMEM;
 338         rc = sclp_get_cpu_info(info);
 339         if (rc)
 340                 goto out;
 341         for (cpu = 0; cpu < info->combined; cpu++) {
 342                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
 343                         continue;
 344                 cpu_id = info->cpu[cpu].address;
 345                 if (cpu_known(cpu_id))
 346                         continue;
 347                 __cpu_logical_map[logical_cpu] = cpu_id;
 348                 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
 349                 cpu_set(logical_cpu, cpu_present_map);
 350                 if (cpu >= info->configured)
 351                         smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
 352                 else
 353                         smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
 354                 logical_cpu = cpumask_next(logical_cpu, &avail);
 355                 if (logical_cpu >= nr_cpu_ids)
 356                         break;
 357         }
 358 out:
 359         kfree(info);
 360         return rc;
 361 }
 362
 363 static int __smp_rescan_cpus(void)
 364 {
 365         cpumask_t avail;
 366
 367         cpus_xor(avail, cpu_possible_map, cpu_present_map);
 368         if (smp_use_sigp_detection)
 369                 return smp_rescan_cpus_sigp(avail);
 370         else
 371                 return smp_rescan_cpus_sclp(avail);
 372 }
 373
 374 static void __init smp_detect_cpus(void)
 375 {
 376         unsigned int cpu, c_cpus, s_cpus;
 377         struct sclp_cpu_info *info;
 378         u16 boot_cpu_addr, cpu_addr;
 379
 380         c_cpus = 1;
 381         s_cpus = 0;
 382         boot_cpu_addr = __cpu_logical_map[0];
 383         info = kmalloc(sizeof(*info), GFP_KERNEL);
 384         if (!info)
 385                 panic("smp_detect_cpus failed to allocate memory\n");
 386         /* Use sigp detection algorithm if sclp doesn't work. */
 387         if (sclp_get_cpu_info(info)) {
 388                 smp_use_sigp_detection = 1;
 389                 for (cpu = 0; cpu <= MAX_CPU_ADDRESS; cpu++) {
 390                         if (cpu == boot_cpu_addr)
 391                                 continue;
 392                         __cpu_logical_map[CPU_INIT_NO] = cpu;
 393                         if (!cpu_stopped(CPU_INIT_NO))
 394                                 continue;
 395                         smp_get_save_area(c_cpus, cpu);
 396                         c_cpus++;
 397                 }
 398                 goto out;
 399         }
 400
 401         if (info->has_cpu_type) {
 402                 for (cpu = 0; cpu < info->combined; cpu++) {
 403                         if (info->cpu[cpu].address == boot_cpu_addr) {
 404                                 smp_cpu_type = info->cpu[cpu].type;
 405                                 break;
 406                         }
 407                 }
 408         }
 409
 410         for (cpu = 0; cpu < info->combined; cpu++) {
 411                 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
 412                         continue;
 413                 cpu_addr = info->cpu[cpu].address;
 414                 if (cpu_addr == boot_cpu_addr)
 415                         continue;
 416                 __cpu_logical_map[CPU_INIT_NO] = cpu_addr;
 417                 if (!cpu_stopped(CPU_INIT_NO)) {
 418                         s_cpus++;
 419                         continue;
 420                 }
 421                 smp_get_save_area(c_cpus, cpu_addr);
 422                 c_cpus++;
 423         }
 424 out:
 425         kfree(info);
 426         pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
 427         get_online_cpus();
 428         __smp_rescan_cpus();
 429         put_online_cpus();
 430 }
 431
 432 /*
 433  *      Activate a secondary processor.
 434  */
 435 int __cpuinit start_secondary(void *cpuvoid)
 436 {
 437         /* Setup the cpu */
 438         cpu_init();
 439         preempt_disable();
 440         /* Enable TOD clock interrupts on the secondary cpu. */
 441         init_cpu_timer();
 442         /* Enable cpu timer interrupts on the secondary cpu. */
 443         init_cpu_vtimer();
 444         /* Enable pfault pseudo page faults on this cpu. */
 445         pfault_init();
 446
 447         /* call cpu notifiers */
 448         notify_cpu_starting(smp_processor_id());
 449         /* Mark this cpu as online */
 450         ipi_call_lock();
 451         cpu_set(smp_processor_id(), cpu_online_map);
 452         ipi_call_unlock();
 453         /* Switch on interrupts */
 454         local_irq_enable();
 455         /* Print info about this processor */
 456         print_cpu_info();
 457         /* cpu_idle will call schedule for us */
 458         cpu_idle();
 459         return 0;
 460 }
 461
 462 static void __init smp_create_idle(unsigned int cpu)
 463 {
 464         struct task_struct *p;
 465
 466         /*
 467          *  don't care about the psw and regs settings since we'll never
 468          *  reschedule the forked task.
 469          */
 470         p = fork_idle(cpu);
 471         if (IS_ERR(p))
 472                 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
 473         current_set[cpu] = p;
 474 }
 475
 476 static int __cpuinit smp_alloc_lowcore(int cpu)
 477 {
 478         unsigned long async_stack, panic_stack;
 479         struct _lowcore *lowcore;
 480
 481         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
 482         if (!lowcore)
 483                 return -ENOMEM;
 484         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
 485         panic_stack = __get_free_page(GFP_KERNEL);
 486         if (!panic_stack || !async_stack)
 487                 goto out;
 488         memcpy(lowcore, &S390_lowcore, 512);
 489         memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
 490         lowcore->async_stack = async_stack + ASYNC_SIZE;
 491         lowcore->panic_stack = panic_stack + PAGE_SIZE;
 492
 493 #ifndef CONFIG_64BIT
 494         if (MACHINE_HAS_IEEE) {
 495                 unsigned long save_area;
 496
 497                 save_area = get_zeroed_page(GFP_KERNEL);
 498                 if (!save_area)
 499                         goto out;
 500                 lowcore->extended_save_area_addr = (u32) save_area;
 501         }
 502 #else
 503         if (vdso_alloc_per_cpu(cpu, lowcore))
 504                 goto out;
 505 #endif
 506         lowcore_ptr[cpu] = lowcore;
 507         return 0;
 508
 509 out:
 510         free_page(panic_stack);
 511         free_pages(async_stack, ASYNC_ORDER);
 512         free_pages((unsigned long) lowcore, LC_ORDER);
 513         return -ENOMEM;
 514 }
 515
 516 static void smp_free_lowcore(int cpu)
 517 {
 518         struct _lowcore *lowcore;
 519
 520         lowcore = lowcore_ptr[cpu];
 521 #ifndef CONFIG_64BIT
 522         if (MACHINE_HAS_IEEE)
 523                 free_page((unsigned long) lowcore->extended_save_area_addr);
 524 #else
 525         vdso_free_per_cpu(cpu, lowcore);
 526 #endif
 527         free_page(lowcore->panic_stack - PAGE_SIZE);
 528         free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
 529         free_pages((unsigned long) lowcore, LC_ORDER);
 530         lowcore_ptr[cpu] = NULL;
 531 }
 532
 533 /* Upping and downing of CPUs */
 534 int __cpuinit __cpu_up(unsigned int cpu)
 535 {
 536         struct task_struct *idle;
 537         struct _lowcore *cpu_lowcore;
 538         struct stack_frame *sf;
 539         sigp_ccode ccode;
 540         u32 lowcore;
 541
 542         if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
 543                 return -EIO;
 544         if (smp_alloc_lowcore(cpu))
 545                 return -ENOMEM;
 546         do {
 547                 ccode = signal_processor(cpu, sigp_initial_cpu_reset);
 548                 if (ccode == sigp_busy)
 549                         udelay(10);
 550                 if (ccode == sigp_not_operational)
 551                         goto err_out;
 552         } while (ccode == sigp_busy);
 553
 554         lowcore = (u32)(unsigned long)lowcore_ptr[cpu];
 555         while (signal_processor_p(lowcore, cpu, sigp_set_prefix) == sigp_busy)
 556                 udelay(10);
 557
 558         idle = current_set[cpu];
 559         cpu_lowcore = lowcore_ptr[cpu];
 560         cpu_lowcore->kernel_stack = (unsigned long)
 561                 task_stack_page(idle) + THREAD_SIZE;
 562         cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
 563         sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
 564                                      - sizeof(struct pt_regs)
 565                                      - sizeof(struct stack_frame));
 566         memset(sf, 0, sizeof(struct stack_frame));
 567         sf->gprs[9] = (unsigned long) sf;
 568         cpu_lowcore->save_area[15] = (unsigned long) sf;
 569         __ctl_store(cpu_lowcore->cregs_save_area, 0, 15);
 570         asm volatile(
 571                 "       stam    0,15,0(%0)"
 572                 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
 573         cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
 574         cpu_lowcore->current_task = (unsigned long) idle;
 575         cpu_lowcore->cpu_nr = cpu;
 576         cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
 577         cpu_lowcore->machine_flags = S390_lowcore.machine_flags;
 578         cpu_lowcore->ftrace_func = S390_lowcore.ftrace_func;
 579         eieio();
 580
 581         while (signal_processor(cpu, sigp_restart) == sigp_busy)
 582                 udelay(10);
 583
 584         while (!cpu_online(cpu))
 585                 cpu_relax();
 586         return 0;
 587
 588 err_out:
 589         smp_free_lowcore(cpu);
 590         return -EIO;
 591 }
 592
 593 static int __init setup_possible_cpus(char *s)
 594 {
 595         int pcpus, cpu;
 596
 597         pcpus = simple_strtoul(s, NULL, 0);
 598         init_cpu_possible(cpumask_of(0));
 599         for (cpu = 1; cpu < pcpus && cpu < nr_cpu_ids; cpu++)
 600                 set_cpu_possible(cpu, true);
 601         return 0;
 602 }
 603 early_param("possible_cpus", setup_possible_cpus);
 604
 605 #ifdef CONFIG_HOTPLUG_CPU
 606
 607 int __cpu_disable(void)
 608 {
 609         struct ec_creg_mask_parms cr_parms;
 610         int cpu = smp_processor_id();
 611
 612         cpu_clear(cpu, cpu_online_map);
 613
 614         /* Disable pfault pseudo page faults on this cpu. */
 615         pfault_fini();
 616
 617         memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
 618         memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
 619
 620         /* disable all external interrupts */
 621         cr_parms.orvals[0] = 0;
 622         cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 12 |
 623                                 1 << 11 | 1 << 10 | 1 <<  6 | 1 <<  4);
 624         /* disable all I/O interrupts */
 625         cr_parms.orvals[6] = 0;
 626         cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
 627                                 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
 628         /* disable most machine checks */
 629         cr_parms.orvals[14] = 0;
 630         cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
 631                                  1 << 25 | 1 << 24);
 632
 633         smp_ctl_bit_callback(&cr_parms);
 634
 635         return 0;
 636 }
 637
 638 void __cpu_die(unsigned int cpu)
 639 {
 640         /* Wait until target cpu is down */
 641         while (!cpu_stopped(cpu))
 642                 cpu_relax();
 643         while (signal_processor_p(0, cpu, sigp_set_prefix) == sigp_busy)
 644                 udelay(10);
 645         smp_free_lowcore(cpu);
 646         pr_info("Processor %d stopped\n", cpu);
 647 }
 648
 649 void cpu_die(void)
 650 {
 651         idle_task_exit();
 652         while (signal_processor(smp_processor_id(), sigp_stop) == sigp_busy)
 653                 cpu_relax();
 654         for (;;);
 655 }
 656
 657 #endif /* CONFIG_HOTPLUG_CPU */
 658
 659 void __init smp_prepare_cpus(unsigned int max_cpus)
 660 {
 661 #ifndef CONFIG_64BIT
 662         unsigned long save_area = 0;
 663 #endif
 664         unsigned long async_stack, panic_stack;
 665         struct _lowcore *lowcore;
 666         unsigned int cpu;
 667
 668         smp_detect_cpus();
 669
 670         /* request the 0x1201 emergency signal external interrupt */
 671         if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
 672                 panic("Couldn't request external interrupt 0x1201");
 673         print_cpu_info();
 674
 675         /* Reallocate current lowcore, but keep its contents. */
 676         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
 677         panic_stack = __get_free_page(GFP_KERNEL);
 678         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
 679         BUG_ON(!lowcore || !panic_stack || !async_stack);
 680 #ifndef CONFIG_64BIT
 681         if (MACHINE_HAS_IEEE)
 682                 save_area = get_zeroed_page(GFP_KERNEL);
 683 #endif
 684         local_irq_disable();
 685         local_mcck_disable();
 686         lowcore_ptr[smp_processor_id()] = lowcore;
 687         *lowcore = S390_lowcore;
 688         lowcore->panic_stack = panic_stack + PAGE_SIZE;
 689         lowcore->async_stack = async_stack + ASYNC_SIZE;
 690 #ifndef CONFIG_64BIT
 691         if (MACHINE_HAS_IEEE)
 692                 lowcore->extended_save_area_addr = (u32) save_area;
 693 #endif
 694         set_prefix((u32)(unsigned long) lowcore);
 695         local_mcck_enable();
 696         local_irq_enable();
 697 #ifdef CONFIG_64BIT
 698         if (vdso_alloc_per_cpu(smp_processor_id(), &S390_lowcore))
 699                 BUG();
 700 #endif
 701         for_each_possible_cpu(cpu)
 702                 if (cpu != smp_processor_id())
 703                         smp_create_idle(cpu);
 704 }
 705
 706 void __init smp_prepare_boot_cpu(void)
 707 {
 708         BUG_ON(smp_processor_id() != 0);
 709
 710         current_thread_info()->cpu = 0;
 711         cpu_set(0, cpu_present_map);
 712         cpu_set(0, cpu_online_map);
 713         S390_lowcore.percpu_offset = __per_cpu_offset[0];
 714         current_set[0] = current;
 715         smp_cpu_state[0] = CPU_STATE_CONFIGURED;
 716         smp_cpu_polarization[0] = POLARIZATION_UNKNWN;
 717 }
 718
 719 void __init smp_cpus_done(unsigned int max_cpus)
 720 {
 721 }
 722
 723 void __init smp_setup_processor_id(void)
 724 {
 725         S390_lowcore.cpu_nr = 0;
 726         __cpu_logical_map[0] = stap();
 727 }
 728
 729 /*
 730  * the frequency of the profiling timer can be changed
 731  * by writing a multiplier value into /proc/profile.
 732  *
 733  * usually you want to run this on all CPUs ;)
 734  */
 735 int setup_profiling_timer(unsigned int multiplier)
 736 {
 737         return 0;
 738 }
 739
 740 #ifdef CONFIG_HOTPLUG_CPU
 741 static ssize_t cpu_configure_show(struct sys_device *dev,
 742                                 struct sysdev_attribute *attr, char *buf)
 743 {
 744         ssize_t count;
 745
 746         mutex_lock(&smp_cpu_state_mutex);
 747         count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
 748         mutex_unlock(&smp_cpu_state_mutex);
 749         return count;
 750 }
 751
 752 static ssize_t cpu_configure_store(struct sys_device *dev,
 753                                   struct sysdev_attribute *attr,
 754                                   const char *buf, size_t count)
 755 {
 756         int cpu = dev->id;
 757         int val, rc;
 758         char delim;
 759
 760         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 761                 return -EINVAL;
 762         if (val != 0 && val != 1)
 763                 return -EINVAL;
 764
 765         get_online_cpus();
 766         mutex_lock(&smp_cpu_state_mutex);
 767         rc = -EBUSY;
 768         if (cpu_online(cpu))
 769                 goto out;
 770         rc = 0;
 771         switch (val) {
 772         case 0:
 773                 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
 774                         rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
 775                         if (!rc) {
 776                                 smp_cpu_state[cpu] = CPU_STATE_STANDBY;
 777                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 778                         }
 779                 }
 780                 break;
 781         case 1:
 782                 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
 783                         rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
 784                         if (!rc) {
 785                                 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
 786                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 787                         }
 788                 }
 789                 break;
 790         default:
 791                 break;
 792         }
 793 out:
 794         mutex_unlock(&smp_cpu_state_mutex);
 795         put_online_cpus();
 796         return rc ? rc : count;
 797 }
 798 static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
 799 #endif /* CONFIG_HOTPLUG_CPU */
 800
 801 static ssize_t cpu_polarization_show(struct sys_device *dev,
 802                                      struct sysdev_attribute *attr, char *buf)
 803 {
 804         int cpu = dev->id;
 805         ssize_t count;
 806
 807         mutex_lock(&smp_cpu_state_mutex);
 808         switch (smp_cpu_polarization[cpu]) {
 809         case POLARIZATION_HRZ:
 810                 count = sprintf(buf, "horizontal\n");
 811                 break;
 812         case POLARIZATION_VL:
 813                 count = sprintf(buf, "vertical:low\n");
 814                 break;
 815         case POLARIZATION_VM:
 816                 count = sprintf(buf, "vertical:medium\n");
 817                 break;
 818         case POLARIZATION_VH:
 819                 count = sprintf(buf, "vertical:high\n");
 820                 break;
 821         default:
 822                 count = sprintf(buf, "unknown\n");
 823                 break;
 824         }
 825         mutex_unlock(&smp_cpu_state_mutex);
 826         return count;
 827 }
 828 static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL);
 829
 830 static ssize_t show_cpu_address(struct sys_device *dev,
 831                                 struct sysdev_attribute *attr, char *buf)
 832 {
 833         return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
 834 }
 835 static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
 836
 837
 838 static struct attribute *cpu_common_attrs[] = {
 839 #ifdef CONFIG_HOTPLUG_CPU
 840         &attr_configure.attr,
 841 #endif
 842         &attr_address.attr,
 843         &attr_polarization.attr,
 844         NULL,
 845 };
 846
 847 static struct attribute_group cpu_common_attr_group = {
 848         .attrs = cpu_common_attrs,
 849 };
 850
 851 static ssize_t show_capability(struct sys_device *dev,
 852                                 struct sysdev_attribute *attr, char *buf)
 853 {
 854         unsigned int capability;
 855         int rc;
 856
 857         rc = get_cpu_capability(&capability);
 858         if (rc)
 859                 return rc;
 860         return sprintf(buf, "%u\n", capability);
 861 }
 862 static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
 863
 864 static ssize_t show_idle_count(struct sys_device *dev,
 865                                 struct sysdev_attribute *attr, char *buf)
 866 {
 867         struct s390_idle_data *idle;
 868         unsigned long long idle_count;
 869         unsigned int sequence;
 870
 871         idle = &per_cpu(s390_idle, dev->id);
 872 repeat:
 873         sequence = idle->sequence;
 874         smp_rmb();
 875         if (sequence & 1)
 876                 goto repeat;
 877         idle_count = idle->idle_count;
 878         if (idle->idle_enter)
 879                 idle_count++;
 880         smp_rmb();
 881         if (idle->sequence != sequence)
 882                 goto repeat;
 883         return sprintf(buf, "%llu\n", idle_count);
 884 }
 885 static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL);
 886
 887 static ssize_t show_idle_time(struct sys_device *dev,
 888                                 struct sysdev_attribute *attr, char *buf)
 889 {
 890         struct s390_idle_data *idle;
 891         unsigned long long now, idle_time, idle_enter;
 892         unsigned int sequence;
 893
 894         idle = &per_cpu(s390_idle, dev->id);
 895         now = get_clock();
 896 repeat:
 897         sequence = idle->sequence;
 898         smp_rmb();
 899         if (sequence & 1)
 900                 goto repeat;
 901         idle_time = idle->idle_time;
 902         idle_enter = idle->idle_enter;
 903         if (idle_enter != 0ULL && idle_enter < now)
 904                 idle_time += now - idle_enter;
 905         smp_rmb();
 906         if (idle->sequence != sequence)
 907                 goto repeat;
 908         return sprintf(buf, "%llu\n", idle_time >> 12);
 909 }
 910 static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
 911
 912 static struct attribute *cpu_online_attrs[] = {
 913         &attr_capability.attr,
 914         &attr_idle_count.attr,
 915         &attr_idle_time_us.attr,
 916         NULL,
 917 };
 918
 919 static struct attribute_group cpu_online_attr_group = {
 920         .attrs = cpu_online_attrs,
 921 };
 922
 923 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
 924                                     unsigned long action, void *hcpu)
 925 {
 926         unsigned int cpu = (unsigned int)(long)hcpu;
 927         struct cpu *c = &per_cpu(cpu_devices, cpu);
 928         struct sys_device *s = &c->sysdev;
 929         struct s390_idle_data *idle;
 930
 931         switch (action) {
 932         case CPU_ONLINE:
 933         case CPU_ONLINE_FROZEN:
 934                 idle = &per_cpu(s390_idle, cpu);
 935                 memset(idle, 0, sizeof(struct s390_idle_data));
 936                 if (sysfs_create_group(&s->kobj, &cpu_online_attr_group))
 937                         return NOTIFY_BAD;
 938                 break;
 939         case CPU_DEAD:
 940         case CPU_DEAD_FROZEN:
 941                 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
 942                 break;
 943         }
 944         return NOTIFY_OK;
 945 }
 946
 947 static struct notifier_block __cpuinitdata smp_cpu_nb = {
 948         .notifier_call = smp_cpu_notify,
 949 };
 950
 951 static int __devinit smp_add_present_cpu(int cpu)
 952 {
 953         struct cpu *c = &per_cpu(cpu_devices, cpu);
 954         struct sys_device *s = &c->sysdev;
 955         int rc;
 956
 957         c->hotpluggable = 1;
 958         rc = register_cpu(c, cpu);
 959         if (rc)
 960                 goto out;
 961         rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
 962         if (rc)
 963                 goto out_cpu;
 964         if (!cpu_online(cpu))
 965                 goto out;
 966         rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
 967         if (!rc)
 968                 return 0;
 969         sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
 970 out_cpu:
 971 #ifdef CONFIG_HOTPLUG_CPU
 972         unregister_cpu(c);
 973 #endif
 974 out:
 975         return rc;
 976 }
 977
 978 #ifdef CONFIG_HOTPLUG_CPU
 979
 980 int __ref smp_rescan_cpus(void)
 981 {
 982         cpumask_t newcpus;
 983         int cpu;
 984         int rc;
 985
 986         get_online_cpus();
 987         mutex_lock(&smp_cpu_state_mutex);
 988         newcpus = cpu_present_map;
 989         rc = __smp_rescan_cpus();
 990         if (rc)
 991                 goto out;
 992         cpus_andnot(newcpus, cpu_present_map, newcpus);
 993         for_each_cpu_mask(cpu, newcpus) {
 994                 rc = smp_add_present_cpu(cpu);
 995                 if (rc)
 996                         cpu_clear(cpu, cpu_present_map);
 997         }
 998         rc = 0;
 999 out:
1000         mutex_unlock(&smp_cpu_state_mutex);
1001         put_online_cpus();
1002         if (!cpus_empty(newcpus))
1003                 topology_schedule_update();
1004         return rc;
1005 }
1006
1007 static ssize_t __ref rescan_store(struct sysdev_class *class, const char *buf,
1008                                   size_t count)
1009 {
1010         int rc;
1011
1012         rc = smp_rescan_cpus();
1013         return rc ? rc : count;
1014 }
1015 static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store);
1016 #endif /* CONFIG_HOTPLUG_CPU */
1017
1018 static ssize_t dispatching_show(struct sysdev_class *class, char *buf)
1019 {
1020         ssize_t count;
1021
1022         mutex_lock(&smp_cpu_state_mutex);
1023         count = sprintf(buf, "%d\n", cpu_management);
1024         mutex_unlock(&smp_cpu_state_mutex);
1025         return count;
1026 }
1027
1028 static ssize_t dispatching_store(struct sysdev_class *dev, const char *buf,
1029                                  size_t count)
1030 {
1031         int val, rc;
1032         char delim;
1033
1034         if (sscanf(buf, "%d %c", &val, &delim) != 1)
1035                 return -EINVAL;
1036         if (val != 0 && val != 1)
1037                 return -EINVAL;
1038         rc = 0;
1039         get_online_cpus();
1040         mutex_lock(&smp_cpu_state_mutex);
1041         if (cpu_management == val)
1042                 goto out;
1043         rc = topology_set_cpu_management(val);
1044         if (!rc)
1045                 cpu_management = val;
1046 out:
1047         mutex_unlock(&smp_cpu_state_mutex);
1048         put_online_cpus();
1049         return rc ? rc : count;
1050 }
1051 static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
1052                          dispatching_store);
1053
1054 static int __init topology_init(void)
1055 {
1056         int cpu;
1057         int rc;
1058
1059         register_cpu_notifier(&smp_cpu_nb);
1060
1061 #ifdef CONFIG_HOTPLUG_CPU
1062         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan);
1063         if (rc)
1064                 return rc;
1065 #endif
1066         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching);
1067         if (rc)
1068                 return rc;
1069         for_each_present_cpu(cpu) {
1070                 rc = smp_add_present_cpu(cpu);
1071                 if (rc)
1072                         return rc;
1073         }
1074         return 0;
1075 }
1076 subsys_initcall(topology_init);