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   1 /*
   2  *  arch/s390/kernel/smp.c
   3  *
   4  *    Copyright IBM Corp. 1999,2007
   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/cpu.h>
  36 #include <linux/timex.h>
  37 #include <linux/bootmem.h>
  38 #include <asm/ipl.h>
  39 #include <asm/setup.h>
  40 #include <asm/sigp.h>
  41 #include <asm/pgalloc.h>
  42 #include <asm/irq.h>
  43 #include <asm/s390_ext.h>
  44 #include <asm/cpcmd.h>
  45 #include <asm/tlbflush.h>
  46 #include <asm/timer.h>
  47 #include <asm/lowcore.h>
  48 #include <asm/sclp.h>
  49 #include <asm/cpu.h>
  50 #include <asm/vdso.h>
  51 #include "entry.h"
  52
  53 /*
  54  * An array with a pointer the lowcore of every CPU.
  55  */
  56 struct _lowcore *lowcore_ptr[NR_CPUS];
  57 EXPORT_SYMBOL(lowcore_ptr);
  58
  59 static struct task_struct *current_set[NR_CPUS];
  60
  61 static u8 smp_cpu_type;
  62 static int smp_use_sigp_detection;
  63
  64 enum s390_cpu_state {
  65         CPU_STATE_STANDBY,
  66         CPU_STATE_CONFIGURED,
  67 };
  68
  69 DEFINE_MUTEX(smp_cpu_state_mutex);
  70 int smp_cpu_polarization[NR_CPUS];
  71 static int smp_cpu_state[NR_CPUS];
  72 static int cpu_management;
  73
  74 static DEFINE_PER_CPU(struct cpu, cpu_devices);
  75
  76 static void smp_ext_bitcall(int, ec_bit_sig);
  77
  78 void smp_send_stop(void)
  79 {
  80         int cpu, rc;
  81
  82         /* Disable all interrupts/machine checks */
  83         __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
  84
  85         /* write magic number to zero page (absolute 0) */
  86         lowcore_ptr[smp_processor_id()]->panic_magic = __PANIC_MAGIC;
  87
  88         /* stop all processors */
  89         for_each_online_cpu(cpu) {
  90                 if (cpu == smp_processor_id())
  91                         continue;
  92                 do {
  93                         rc = signal_processor(cpu, sigp_stop);
  94                 } while (rc == sigp_busy);
  95
  96                 while (!smp_cpu_not_running(cpu))
  97                         cpu_relax();
  98         }
  99 }
 100
 101 /*
 102  * This is the main routine where commands issued by other
 103  * cpus are handled.
 104  */
 105
 106 static void do_ext_call_interrupt(__u16 code)
 107 {
 108         unsigned long bits;
 109
 110         /*
 111          * handle bit signal external calls
 112          *
 113          * For the ec_schedule signal we have to do nothing. All the work
 114          * is done automatically when we return from the interrupt.
 115          */
 116         bits = xchg(&S390_lowcore.ext_call_fast, 0);
 117
 118         if (test_bit(ec_call_function, &bits))
 119                 generic_smp_call_function_interrupt();
 120
 121         if (test_bit(ec_call_function_single, &bits))
 122                 generic_smp_call_function_single_interrupt();
 123 }
 124
 125 /*
 126  * Send an external call sigp to another cpu and return without waiting
 127  * for its completion.
 128  */
 129 static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
 130 {
 131         /*
 132          * Set signaling bit in lowcore of target cpu and kick it
 133          */
 134         set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
 135         while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
 136                 udelay(10);
 137 }
 138
 139 void arch_send_call_function_ipi(cpumask_t mask)
 140 {
 141         int cpu;
 142
 143         for_each_cpu_mask(cpu, mask)
 144                 smp_ext_bitcall(cpu, ec_call_function);
 145 }
 146
 147 void arch_send_call_function_single_ipi(int cpu)
 148 {
 149         smp_ext_bitcall(cpu, ec_call_function_single);
 150 }
 151
 152 #ifndef CONFIG_64BIT
 153 /*
 154  * this function sends a 'purge tlb' signal to another CPU.
 155  */
 156 static void smp_ptlb_callback(void *info)
 157 {
 158         __tlb_flush_local();
 159 }
 160
 161 void smp_ptlb_all(void)
 162 {
 163         on_each_cpu(smp_ptlb_callback, NULL, 1);
 164 }
 165 EXPORT_SYMBOL(smp_ptlb_all);
 166 #endif /* ! CONFIG_64BIT */
 167
 168 /*
 169  * this function sends a 'reschedule' IPI to another CPU.
 170  * it goes straight through and wastes no time serializing
 171  * anything. Worst case is that we lose a reschedule ...
 172  */
 173 void smp_send_reschedule(int cpu)
 174 {
 175         smp_ext_bitcall(cpu, ec_schedule);
 176 }
 177
 178 /*
 179  * parameter area for the set/clear control bit callbacks
 180  */
 181 struct ec_creg_mask_parms {
 182         unsigned long orvals[16];
 183         unsigned long andvals[16];
 184 };
 185
 186 /*
 187  * callback for setting/clearing control bits
 188  */
 189 static void smp_ctl_bit_callback(void *info)
 190 {
 191         struct ec_creg_mask_parms *pp = info;
 192         unsigned long cregs[16];
 193         int i;
 194
 195         __ctl_store(cregs, 0, 15);
 196         for (i = 0; i <= 15; i++)
 197                 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
 198         __ctl_load(cregs, 0, 15);
 199 }
 200
 201 /*
 202  * Set a bit in a control register of all cpus
 203  */
 204 void smp_ctl_set_bit(int cr, int bit)
 205 {
 206         struct ec_creg_mask_parms parms;
 207
 208         memset(&parms.orvals, 0, sizeof(parms.orvals));
 209         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
 210         parms.orvals[cr] = 1 << bit;
 211         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 212 }
 213 EXPORT_SYMBOL(smp_ctl_set_bit);
 214
 215 /*
 216  * Clear a bit in a control register of all cpus
 217  */
 218 void smp_ctl_clear_bit(int cr, int bit)
 219 {
 220         struct ec_creg_mask_parms parms;
 221
 222         memset(&parms.orvals, 0, sizeof(parms.orvals));
 223         memset(&parms.andvals, 0xff, sizeof(parms.andvals));
 224         parms.andvals[cr] = ~(1L << bit);
 225         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 226 }
 227 EXPORT_SYMBOL(smp_ctl_clear_bit);
 228
 229 /*
 230  * In early ipl state a temp. logically cpu number is needed, so the sigp
 231  * functions can be used to sense other cpus. Since NR_CPUS is >= 2 on
 232  * CONFIG_SMP and the ipl cpu is logical cpu 0, it must be 1.
 233  */
 234 #define CPU_INIT_NO     1
 235
 236 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_ZFCPDUMP_MODULE)
 237
 238 /*
 239  * zfcpdump_prefix_array holds prefix registers for the following scenario:
 240  * 64 bit zfcpdump kernel and 31 bit kernel which is to be dumped. We have to
 241  * save its prefix registers, since they get lost, when switching from 31 bit
 242  * to 64 bit.
 243  */
 244 unsigned int zfcpdump_prefix_array[NR_CPUS + 1] \
 245         __attribute__((__section__(".data")));
 246
 247 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
 248 {
 249         if (ipl_info.type != IPL_TYPE_FCP_DUMP)
 250                 return;
 251         if (cpu >= NR_CPUS) {
 252                 pr_warning("CPU %i exceeds the maximum %i and is excluded from "
 253                            "the dump\n", cpu, NR_CPUS - 1);
 254                 return;
 255         }
 256         zfcpdump_save_areas[cpu] = kmalloc(sizeof(union save_area), GFP_KERNEL);
 257         __cpu_logical_map[CPU_INIT_NO] = (__u16) phy_cpu;
 258         while (signal_processor(CPU_INIT_NO, sigp_stop_and_store_status) ==
 259                sigp_busy)
 260                 cpu_relax();
 261         memcpy(zfcpdump_save_areas[cpu],
 262                (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
 263                SAVE_AREA_SIZE);
 264 #ifdef CONFIG_64BIT
 265         /* copy original prefix register */
 266         zfcpdump_save_areas[cpu]->s390x.pref_reg = zfcpdump_prefix_array[cpu];
 267 #endif
 268 }
 269
 270 union save_area *zfcpdump_save_areas[NR_CPUS + 1];
 271 EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
 272
 273 #else
 274
 275 static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
 276
 277 #endif /* CONFIG_ZFCPDUMP || CONFIG_ZFCPDUMP_MODULE */
 278
 279 static int cpu_stopped(int cpu)
 280 {
 281         __u32 status;
 282
 283         /* Check for stopped state */
 284         if (signal_processor_ps(&status, 0, cpu, sigp_sense) ==
 285             sigp_status_stored) {
 286                 if (status & 0x40)
 287                         return 1;
 288         }
 289         return 0;
 290 }
 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 = first_cpu(avail);
 308         if (logical_cpu == NR_CPUS)
 309                 return 0;
 310         for (cpu_id = 0; cpu_id <= 65535; 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 = next_cpu(logical_cpu, avail);
 320                 if (logical_cpu == NR_CPUS)
 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 = first_cpu(avail);
 333         if (logical_cpu == NR_CPUS)
 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 = next_cpu(logical_cpu, avail);
 355                 if (logical_cpu == NR_CPUS)
 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 = S390_lowcore.cpu_data.cpu_addr;
 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 <= 65535; 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(&S390_lowcore.cpu_data);
 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         int lc_order;
 481
 482         lc_order = sizeof(long) == 8 ? 1 : 0;
 483         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, lc_order);
 484         if (!lowcore)
 485                 return -ENOMEM;
 486         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
 487         panic_stack = __get_free_page(GFP_KERNEL);
 488         if (!panic_stack || !async_stack)
 489                 goto out;
 490         memcpy(lowcore, &S390_lowcore, 512);
 491         memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
 492         lowcore->async_stack = async_stack + ASYNC_SIZE;
 493         lowcore->panic_stack = panic_stack + PAGE_SIZE;
 494
 495 #ifndef CONFIG_64BIT
 496         if (MACHINE_HAS_IEEE) {
 497                 unsigned long save_area;
 498
 499                 save_area = get_zeroed_page(GFP_KERNEL);
 500                 if (!save_area)
 501                         goto out;
 502                 lowcore->extended_save_area_addr = (u32) save_area;
 503         }
 504 #else
 505         if (vdso_alloc_per_cpu(cpu, lowcore))
 506                 goto out;
 507 #endif
 508         lowcore_ptr[cpu] = lowcore;
 509         return 0;
 510
 511 out:
 512         free_page(panic_stack);
 513         free_pages(async_stack, ASYNC_ORDER);
 514         free_pages((unsigned long) lowcore, lc_order);
 515         return -ENOMEM;
 516 }
 517
 518 #ifdef CONFIG_HOTPLUG_CPU
 519 static void smp_free_lowcore(int cpu)
 520 {
 521         struct _lowcore *lowcore;
 522         int lc_order;
 523
 524         lc_order = sizeof(long) == 8 ? 1 : 0;
 525         lowcore = lowcore_ptr[cpu];
 526 #ifndef CONFIG_64BIT
 527         if (MACHINE_HAS_IEEE)
 528                 free_page((unsigned long) lowcore->extended_save_area_addr);
 529 #else
 530         vdso_free_per_cpu(cpu, lowcore);
 531 #endif
 532         free_page(lowcore->panic_stack - PAGE_SIZE);
 533         free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
 534         free_pages((unsigned long) lowcore, lc_order);
 535         lowcore_ptr[cpu] = NULL;
 536 }
 537 #endif /* CONFIG_HOTPLUG_CPU */
 538
 539 /* Upping and downing of CPUs */
 540 int __cpuinit __cpu_up(unsigned int cpu)
 541 {
 542         struct task_struct *idle;
 543         struct _lowcore *cpu_lowcore;
 544         struct stack_frame *sf;
 545         sigp_ccode ccode;
 546
 547         if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
 548                 return -EIO;
 549         if (smp_alloc_lowcore(cpu))
 550                 return -ENOMEM;
 551
 552         ccode = signal_processor_p((__u32)(unsigned long)(lowcore_ptr[cpu]),
 553                                    cpu, sigp_set_prefix);
 554         if (ccode)
 555                 return -EIO;
 556
 557         idle = current_set[cpu];
 558         cpu_lowcore = lowcore_ptr[cpu];
 559         cpu_lowcore->kernel_stack = (unsigned long)
 560                 task_stack_page(idle) + THREAD_SIZE;
 561         cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
 562         sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
 563                                      - sizeof(struct pt_regs)
 564                                      - sizeof(struct stack_frame));
 565         memset(sf, 0, sizeof(struct stack_frame));
 566         sf->gprs[9] = (unsigned long) sf;
 567         cpu_lowcore->save_area[15] = (unsigned long) sf;
 568         __ctl_store(cpu_lowcore->cregs_save_area, 0, 15);
 569         asm volatile(
 570                 "       stam    0,15,0(%0)"
 571                 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
 572         cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
 573         cpu_lowcore->current_task = (unsigned long) idle;
 574         cpu_lowcore->cpu_data.cpu_nr = cpu;
 575         cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
 576         cpu_lowcore->ipl_device = S390_lowcore.ipl_device;
 577         eieio();
 578
 579         while (signal_processor(cpu, sigp_restart) == sigp_busy)
 580                 udelay(10);
 581
 582         while (!cpu_online(cpu))
 583                 cpu_relax();
 584         return 0;
 585 }
 586
 587 static int __init setup_possible_cpus(char *s)
 588 {
 589         int pcpus, cpu;
 590
 591         pcpus = simple_strtoul(s, NULL, 0);
 592         cpu_possible_map = cpumask_of_cpu(0);
 593         for (cpu = 1; cpu < pcpus && cpu < NR_CPUS; cpu++)
 594                 cpu_set(cpu, cpu_possible_map);
 595         return 0;
 596 }
 597 early_param("possible_cpus", setup_possible_cpus);
 598
 599 #ifdef CONFIG_HOTPLUG_CPU
 600
 601 int __cpu_disable(void)
 602 {
 603         struct ec_creg_mask_parms cr_parms;
 604         int cpu = smp_processor_id();
 605
 606         cpu_clear(cpu, cpu_online_map);
 607
 608         /* Disable pfault pseudo page faults on this cpu. */
 609         pfault_fini();
 610
 611         memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
 612         memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
 613
 614         /* disable all external interrupts */
 615         cr_parms.orvals[0] = 0;
 616         cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 12 |
 617                                 1 << 11 | 1 << 10 | 1 <<  6 | 1 <<  4);
 618         /* disable all I/O interrupts */
 619         cr_parms.orvals[6] = 0;
 620         cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
 621                                 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
 622         /* disable most machine checks */
 623         cr_parms.orvals[14] = 0;
 624         cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
 625                                  1 << 25 | 1 << 24);
 626
 627         smp_ctl_bit_callback(&cr_parms);
 628
 629         return 0;
 630 }
 631
 632 void __cpu_die(unsigned int cpu)
 633 {
 634         /* Wait until target cpu is down */
 635         while (!smp_cpu_not_running(cpu))
 636                 cpu_relax();
 637         smp_free_lowcore(cpu);
 638         pr_info("Processor %d stopped\n", cpu);
 639 }
 640
 641 void cpu_die(void)
 642 {
 643         idle_task_exit();
 644         signal_processor(smp_processor_id(), sigp_stop);
 645         BUG();
 646         for (;;);
 647 }
 648
 649 #endif /* CONFIG_HOTPLUG_CPU */
 650
 651 void __init smp_prepare_cpus(unsigned int max_cpus)
 652 {
 653 #ifndef CONFIG_64BIT
 654         unsigned long save_area = 0;
 655 #endif
 656         unsigned long async_stack, panic_stack;
 657         struct _lowcore *lowcore;
 658         unsigned int cpu;
 659         int lc_order;
 660
 661         smp_detect_cpus();
 662
 663         /* request the 0x1201 emergency signal external interrupt */
 664         if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
 665                 panic("Couldn't request external interrupt 0x1201");
 666         print_cpu_info(&S390_lowcore.cpu_data);
 667
 668         /* Reallocate current lowcore, but keep its contents. */
 669         lc_order = sizeof(long) == 8 ? 1 : 0;
 670         lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, lc_order);
 671         panic_stack = __get_free_page(GFP_KERNEL);
 672         async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
 673         BUG_ON(!lowcore || !panic_stack || !async_stack);
 674 #ifndef CONFIG_64BIT
 675         if (MACHINE_HAS_IEEE)
 676                 save_area = get_zeroed_page(GFP_KERNEL);
 677 #endif
 678         local_irq_disable();
 679         local_mcck_disable();
 680         lowcore_ptr[smp_processor_id()] = lowcore;
 681         *lowcore = S390_lowcore;
 682         lowcore->panic_stack = panic_stack + PAGE_SIZE;
 683         lowcore->async_stack = async_stack + ASYNC_SIZE;
 684 #ifndef CONFIG_64BIT
 685         if (MACHINE_HAS_IEEE)
 686                 lowcore->extended_save_area_addr = (u32) save_area;
 687 #else
 688         BUG_ON(vdso_alloc_per_cpu(smp_processor_id(), lowcore));
 689 #endif
 690         set_prefix((u32)(unsigned long) lowcore);
 691         local_mcck_enable();
 692         local_irq_enable();
 693         for_each_possible_cpu(cpu)
 694                 if (cpu != smp_processor_id())
 695                         smp_create_idle(cpu);
 696 }
 697
 698 void __init smp_prepare_boot_cpu(void)
 699 {
 700         BUG_ON(smp_processor_id() != 0);
 701
 702         current_thread_info()->cpu = 0;
 703         cpu_set(0, cpu_present_map);
 704         cpu_set(0, cpu_online_map);
 705         S390_lowcore.percpu_offset = __per_cpu_offset[0];
 706         current_set[0] = current;
 707         smp_cpu_state[0] = CPU_STATE_CONFIGURED;
 708         smp_cpu_polarization[0] = POLARIZATION_UNKNWN;
 709 }
 710
 711 void __init smp_cpus_done(unsigned int max_cpus)
 712 {
 713 }
 714
 715 /*
 716  * the frequency of the profiling timer can be changed
 717  * by writing a multiplier value into /proc/profile.
 718  *
 719  * usually you want to run this on all CPUs ;)
 720  */
 721 int setup_profiling_timer(unsigned int multiplier)
 722 {
 723         return 0;
 724 }
 725
 726 #ifdef CONFIG_HOTPLUG_CPU
 727 static ssize_t cpu_configure_show(struct sys_device *dev,
 728                                 struct sysdev_attribute *attr, char *buf)
 729 {
 730         ssize_t count;
 731
 732         mutex_lock(&smp_cpu_state_mutex);
 733         count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
 734         mutex_unlock(&smp_cpu_state_mutex);
 735         return count;
 736 }
 737
 738 static ssize_t cpu_configure_store(struct sys_device *dev,
 739                                   struct sysdev_attribute *attr,
 740                                   const char *buf, size_t count)
 741 {
 742         int cpu = dev->id;
 743         int val, rc;
 744         char delim;
 745
 746         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 747                 return -EINVAL;
 748         if (val != 0 && val != 1)
 749                 return -EINVAL;
 750
 751         get_online_cpus();
 752         mutex_lock(&smp_cpu_state_mutex);
 753         rc = -EBUSY;
 754         if (cpu_online(cpu))
 755                 goto out;
 756         rc = 0;
 757         switch (val) {
 758         case 0:
 759                 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
 760                         rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
 761                         if (!rc) {
 762                                 smp_cpu_state[cpu] = CPU_STATE_STANDBY;
 763                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 764                         }
 765                 }
 766                 break;
 767         case 1:
 768                 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
 769                         rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
 770                         if (!rc) {
 771                                 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
 772                                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 773                         }
 774                 }
 775                 break;
 776         default:
 777                 break;
 778         }
 779 out:
 780         mutex_unlock(&smp_cpu_state_mutex);
 781         put_online_cpus();
 782         return rc ? rc : count;
 783 }
 784 static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
 785 #endif /* CONFIG_HOTPLUG_CPU */
 786
 787 static ssize_t cpu_polarization_show(struct sys_device *dev,
 788                                      struct sysdev_attribute *attr, char *buf)
 789 {
 790         int cpu = dev->id;
 791         ssize_t count;
 792
 793         mutex_lock(&smp_cpu_state_mutex);
 794         switch (smp_cpu_polarization[cpu]) {
 795         case POLARIZATION_HRZ:
 796                 count = sprintf(buf, "horizontal\n");
 797                 break;
 798         case POLARIZATION_VL:
 799                 count = sprintf(buf, "vertical:low\n");
 800                 break;
 801         case POLARIZATION_VM:
 802                 count = sprintf(buf, "vertical:medium\n");
 803                 break;
 804         case POLARIZATION_VH:
 805                 count = sprintf(buf, "vertical:high\n");
 806                 break;
 807         default:
 808                 count = sprintf(buf, "unknown\n");
 809                 break;
 810         }
 811         mutex_unlock(&smp_cpu_state_mutex);
 812         return count;
 813 }
 814 static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL);
 815
 816 static ssize_t show_cpu_address(struct sys_device *dev,
 817                                 struct sysdev_attribute *attr, char *buf)
 818 {
 819         return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
 820 }
 821 static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
 822
 823
 824 static struct attribute *cpu_common_attrs[] = {
 825 #ifdef CONFIG_HOTPLUG_CPU
 826         &attr_configure.attr,
 827 #endif
 828         &attr_address.attr,
 829         &attr_polarization.attr,
 830         NULL,
 831 };
 832
 833 static struct attribute_group cpu_common_attr_group = {
 834         .attrs = cpu_common_attrs,
 835 };
 836
 837 static ssize_t show_capability(struct sys_device *dev,
 838                                 struct sysdev_attribute *attr, char *buf)
 839 {
 840         unsigned int capability;
 841         int rc;
 842
 843         rc = get_cpu_capability(&capability);
 844         if (rc)
 845                 return rc;
 846         return sprintf(buf, "%u\n", capability);
 847 }
 848 static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
 849
 850 static ssize_t show_idle_count(struct sys_device *dev,
 851                                 struct sysdev_attribute *attr, char *buf)
 852 {
 853         struct s390_idle_data *idle;
 854         unsigned long long idle_count;
 855
 856         idle = &per_cpu(s390_idle, dev->id);
 857         spin_lock(&idle->lock);
 858         idle_count = idle->idle_count;
 859         if (idle->idle_enter)
 860                 idle_count++;
 861         spin_unlock(&idle->lock);
 862         return sprintf(buf, "%llu\n", idle_count);
 863 }
 864 static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL);
 865
 866 static ssize_t show_idle_time(struct sys_device *dev,
 867                                 struct sysdev_attribute *attr, char *buf)
 868 {
 869         struct s390_idle_data *idle;
 870         unsigned long long now, idle_time, idle_enter;
 871
 872         idle = &per_cpu(s390_idle, dev->id);
 873         spin_lock(&idle->lock);
 874         now = get_clock();
 875         idle_time = idle->idle_time;
 876         idle_enter = idle->idle_enter;
 877         if (idle_enter != 0ULL && idle_enter < now)
 878                 idle_time += now - idle_enter;
 879         spin_unlock(&idle->lock);
 880         return sprintf(buf, "%llu\n", idle_time >> 12);
 881 }
 882 static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
 883
 884 static struct attribute *cpu_online_attrs[] = {
 885         &attr_capability.attr,
 886         &attr_idle_count.attr,
 887         &attr_idle_time_us.attr,
 888         NULL,
 889 };
 890
 891 static struct attribute_group cpu_online_attr_group = {
 892         .attrs = cpu_online_attrs,
 893 };
 894
 895 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
 896                                     unsigned long action, void *hcpu)
 897 {
 898         unsigned int cpu = (unsigned int)(long)hcpu;
 899         struct cpu *c = &per_cpu(cpu_devices, cpu);
 900         struct sys_device *s = &c->sysdev;
 901         struct s390_idle_data *idle;
 902
 903         switch (action) {
 904         case CPU_ONLINE:
 905         case CPU_ONLINE_FROZEN:
 906                 idle = &per_cpu(s390_idle, cpu);
 907                 spin_lock_irq(&idle->lock);
 908                 idle->idle_enter = 0;
 909                 idle->idle_time = 0;
 910                 idle->idle_count = 0;
 911                 spin_unlock_irq(&idle->lock);
 912                 if (sysfs_create_group(&s->kobj, &cpu_online_attr_group))
 913                         return NOTIFY_BAD;
 914                 break;
 915         case CPU_DEAD:
 916         case CPU_DEAD_FROZEN:
 917                 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
 918                 break;
 919         }
 920         return NOTIFY_OK;
 921 }
 922
 923 static struct notifier_block __cpuinitdata smp_cpu_nb = {
 924         .notifier_call = smp_cpu_notify,
 925 };
 926
 927 static int __devinit smp_add_present_cpu(int cpu)
 928 {
 929         struct cpu *c = &per_cpu(cpu_devices, cpu);
 930         struct sys_device *s = &c->sysdev;
 931         int rc;
 932
 933         c->hotpluggable = 1;
 934         rc = register_cpu(c, cpu);
 935         if (rc)
 936                 goto out;
 937         rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
 938         if (rc)
 939                 goto out_cpu;
 940         if (!cpu_online(cpu))
 941                 goto out;
 942         rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
 943         if (!rc)
 944                 return 0;
 945         sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
 946 out_cpu:
 947 #ifdef CONFIG_HOTPLUG_CPU
 948         unregister_cpu(c);
 949 #endif
 950 out:
 951         return rc;
 952 }
 953
 954 #ifdef CONFIG_HOTPLUG_CPU
 955
 956 int __ref smp_rescan_cpus(void)
 957 {
 958         cpumask_t newcpus;
 959         int cpu;
 960         int rc;
 961
 962         get_online_cpus();
 963         mutex_lock(&smp_cpu_state_mutex);
 964         newcpus = cpu_present_map;
 965         rc = __smp_rescan_cpus();
 966         if (rc)
 967                 goto out;
 968         cpus_andnot(newcpus, cpu_present_map, newcpus);
 969         for_each_cpu_mask(cpu, newcpus) {
 970                 rc = smp_add_present_cpu(cpu);
 971                 if (rc)
 972                         cpu_clear(cpu, cpu_present_map);
 973         }
 974         rc = 0;
 975 out:
 976         mutex_unlock(&smp_cpu_state_mutex);
 977         put_online_cpus();
 978         if (!cpus_empty(newcpus))
 979                 topology_schedule_update();
 980         return rc;
 981 }
 982
 983 static ssize_t __ref rescan_store(struct sysdev_class *class, const char *buf,
 984                                   size_t count)
 985 {
 986         int rc;
 987
 988         rc = smp_rescan_cpus();
 989         return rc ? rc : count;
 990 }
 991 static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store);
 992 #endif /* CONFIG_HOTPLUG_CPU */
 993
 994 static ssize_t dispatching_show(struct sysdev_class *class, char *buf)
 995 {
 996         ssize_t count;
 997
 998         mutex_lock(&smp_cpu_state_mutex);
 999         count = sprintf(buf, "%d\n", cpu_management);
1000         mutex_unlock(&smp_cpu_state_mutex);
1001         return count;
1002 }
1003
1004 static ssize_t dispatching_store(struct sysdev_class *dev, const char *buf,
1005                                  size_t count)
1006 {
1007         int val, rc;
1008         char delim;
1009
1010         if (sscanf(buf, "%d %c", &val, &delim) != 1)
1011                 return -EINVAL;
1012         if (val != 0 && val != 1)
1013                 return -EINVAL;
1014         rc = 0;
1015         get_online_cpus();
1016         mutex_lock(&smp_cpu_state_mutex);
1017         if (cpu_management == val)
1018                 goto out;
1019         rc = topology_set_cpu_management(val);
1020         if (!rc)
1021                 cpu_management = val;
1022 out:
1023         mutex_unlock(&smp_cpu_state_mutex);
1024         put_online_cpus();
1025         return rc ? rc : count;
1026 }
1027 static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
1028                          dispatching_store);
1029
1030 static int __init topology_init(void)
1031 {
1032         int cpu;
1033         int rc;
1034
1035         register_cpu_notifier(&smp_cpu_nb);
1036
1037 #ifdef CONFIG_HOTPLUG_CPU
1038         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan);
1039         if (rc)
1040                 return rc;
1041 #endif
1042         rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching);
1043         if (rc)
1044                 return rc;
1045         for_each_present_cpu(cpu) {
1046                 rc = smp_add_present_cpu(cpu);
1047                 if (rc)
1048                         return rc;
1049         }
1050         return 0;
1051 }
1052 subsys_initcall(topology_init);