arch/s390/kernel/smp.c

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