linux/arch/s390/kernel/smp.c
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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#include <linux/module.h>
  24#include <linux/init.h>
  25#include <linux/mm.h>
  26#include <linux/err.h>
  27#include <linux/spinlock.h>
  28#include <linux/kernel_stat.h>
  29#include <linux/delay.h>
  30#include <linux/cache.h>
  31#include <linux/interrupt.h>
  32#include <linux/cpu.h>
  33#include <linux/timex.h>
  34#include <linux/bootmem.h>
  35#include <asm/ipl.h>
  36#include <asm/setup.h>
  37#include <asm/sigp.h>
  38#include <asm/pgalloc.h>
  39#include <asm/irq.h>
  40#include <asm/s390_ext.h>
  41#include <asm/cpcmd.h>
  42#include <asm/tlbflush.h>
  43#include <asm/timer.h>
  44#include <asm/lowcore.h>
  45#include <asm/sclp.h>
  46#include <asm/cpu.h>
  47#include "entry.h"
  48
  49/*
  50 * An array with a pointer the lowcore of every CPU.
  51 */
  52struct _lowcore *lowcore_ptr[NR_CPUS];
  53EXPORT_SYMBOL(lowcore_ptr);
  54
  55cpumask_t cpu_online_map = CPU_MASK_NONE;
  56EXPORT_SYMBOL(cpu_online_map);
  57
  58cpumask_t cpu_possible_map = CPU_MASK_ALL;
  59EXPORT_SYMBOL(cpu_possible_map);
  60
  61static struct task_struct *current_set[NR_CPUS];
  62
  63static u8 smp_cpu_type;
  64static int smp_use_sigp_detection;
  65
  66enum s390_cpu_state {
  67        CPU_STATE_STANDBY,
  68        CPU_STATE_CONFIGURED,
  69};
  70
  71DEFINE_MUTEX(smp_cpu_state_mutex);
  72int smp_cpu_polarization[NR_CPUS];
  73static int smp_cpu_state[NR_CPUS];
  74static int cpu_management;
  75
  76static DEFINE_PER_CPU(struct cpu, cpu_devices);
  77
  78static void smp_ext_bitcall(int, ec_bit_sig);
  79
  80/*
  81 * Structure and data for __smp_call_function_map(). This is designed to
  82 * minimise static memory requirements. It also looks cleaner.
  83 */
  84static DEFINE_SPINLOCK(call_lock);
  85
  86struct call_data_struct {
  87        void (*func) (void *info);
  88        void *info;
  89        cpumask_t started;
  90        cpumask_t finished;
  91        int wait;
  92};
  93
  94static struct call_data_struct *call_data;
  95
  96/*
  97 * 'Call function' interrupt callback
  98 */
  99static void do_call_function(void)
 100{
 101        void (*func) (void *info) = call_data->func;
 102        void *info = call_data->info;
 103        int wait = call_data->wait;
 104
 105        cpu_set(smp_processor_id(), call_data->started);
 106        (*func)(info);
 107        if (wait)
 108                cpu_set(smp_processor_id(), call_data->finished);;
 109}
 110
 111static void __smp_call_function_map(void (*func) (void *info), void *info,
 112                                    int wait, cpumask_t map)
 113{
 114        struct call_data_struct data;
 115        int cpu, local = 0;
 116
 117        /*
 118         * Can deadlock when interrupts are disabled or if in wrong context.
 119         */
 120        WARN_ON(irqs_disabled() || in_irq());
 121
 122        /*
 123         * Check for local function call. We have to have the same call order
 124         * as in on_each_cpu() because of machine_restart_smp().
 125         */
 126        if (cpu_isset(smp_processor_id(), map)) {
 127                local = 1;
 128                cpu_clear(smp_processor_id(), map);
 129        }
 130
 131        cpus_and(map, map, cpu_online_map);
 132        if (cpus_empty(map))
 133                goto out;
 134
 135        data.func = func;
 136        data.info = info;
 137        data.started = CPU_MASK_NONE;
 138        data.wait = wait;
 139        if (wait)
 140                data.finished = CPU_MASK_NONE;
 141
 142        call_data = &data;
 143
 144        for_each_cpu_mask(cpu, map)
 145                smp_ext_bitcall(cpu, ec_call_function);
 146
 147        /* Wait for response */
 148        while (!cpus_equal(map, data.started))
 149                cpu_relax();
 150        if (wait)
 151                while (!cpus_equal(map, data.finished))
 152                        cpu_relax();
 153out:
 154        if (local) {
 155                local_irq_disable();
 156                func(info);
 157                local_irq_enable();
 158        }
 159}
 160
 161/*
 162 * smp_call_function:
 163 * @func: the function to run; this must be fast and non-blocking
 164 * @info: an arbitrary pointer to pass to the function
 165 * @wait: if true, wait (atomically) until function has completed on other CPUs
 166 *
 167 * Run a function on all other CPUs.
 168 *
 169 * You must not call this function with disabled interrupts, from a
 170 * hardware interrupt handler or from a bottom half.
 171 */
 172int smp_call_function(void (*func) (void *info), void *info, int wait)
 173{
 174        cpumask_t map;
 175
 176        spin_lock(&call_lock);
 177        map = cpu_online_map;
 178        cpu_clear(smp_processor_id(), map);
 179        __smp_call_function_map(func, info, wait, map);
 180        spin_unlock(&call_lock);
 181        return 0;
 182}
 183EXPORT_SYMBOL(smp_call_function);
 184
 185/*
 186 * smp_call_function_single:
 187 * @cpu: the CPU where func should run
 188 * @func: the function to run; this must be fast and non-blocking
 189 * @info: an arbitrary pointer to pass to the function
 190 * @wait: if true, wait (atomically) until function has completed on other CPUs
 191 *
 192 * Run a function on one processor.
 193 *
 194 * You must not call this function with disabled interrupts, from a
 195 * hardware interrupt handler or from a bottom half.
 196 */
 197int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
 198                             int wait)
 199{
 200        spin_lock(&call_lock);
 201        __smp_call_function_map(func, info, wait, cpumask_of_cpu(cpu));
 202        spin_unlock(&call_lock);
 203        return 0;
 204}
 205EXPORT_SYMBOL(smp_call_function_single);
 206
 207/**
 208 * smp_call_function_mask(): Run a function on a set of other CPUs.
 209 * @mask: The set of cpus to run on.  Must not include the current cpu.
 210 * @func: The function to run. This must be fast and non-blocking.
 211 * @info: An arbitrary pointer to pass to the function.
 212 * @wait: If true, wait (atomically) until function has completed on other CPUs.
 213 *
 214 * Returns 0 on success, else a negative status code.
 215 *
 216 * If @wait is true, then returns once @func has returned; otherwise
 217 * it returns just before the target cpu calls @func.
 218 *
 219 * You must not call this function with disabled interrupts or from a
 220 * hardware interrupt handler or from a bottom half handler.
 221 */
 222int smp_call_function_mask(cpumask_t mask, void (*func)(void *), void *info,
 223                           int wait)
 224{
 225        spin_lock(&call_lock);
 226        cpu_clear(smp_processor_id(), mask);
 227        __smp_call_function_map(func, info, wait, mask);
 228        spin_unlock(&call_lock);
 229        return 0;
 230}
 231EXPORT_SYMBOL(smp_call_function_mask);
 232
 233void smp_send_stop(void)
 234{
 235        int cpu, rc;
 236
 237        /* Disable all interrupts/machine checks */
 238        __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
 239
 240        /* write magic number to zero page (absolute 0) */
 241        lowcore_ptr[smp_processor_id()]->panic_magic = __PANIC_MAGIC;
 242
 243        /* stop all processors */
 244        for_each_online_cpu(cpu) {
 245                if (cpu == smp_processor_id())
 246                        continue;
 247                do {
 248                        rc = signal_processor(cpu, sigp_stop);
 249                } while (rc == sigp_busy);
 250
 251                while (!smp_cpu_not_running(cpu))
 252                        cpu_relax();
 253        }
 254}
 255
 256/*
 257 * This is the main routine where commands issued by other
 258 * cpus are handled.
 259 */
 260
 261static void do_ext_call_interrupt(__u16 code)
 262{
 263        unsigned long bits;
 264
 265        /*
 266         * handle bit signal external calls
 267         *
 268         * For the ec_schedule signal we have to do nothing. All the work
 269         * is done automatically when we return from the interrupt.
 270         */
 271        bits = xchg(&S390_lowcore.ext_call_fast, 0);
 272
 273        if (test_bit(ec_call_function, &bits))
 274                do_call_function();
 275}
 276
 277/*
 278 * Send an external call sigp to another cpu and return without waiting
 279 * for its completion.
 280 */
 281static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
 282{
 283        /*
 284         * Set signaling bit in lowcore of target cpu and kick it
 285         */
 286        set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
 287        while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
 288                udelay(10);
 289}
 290
 291#ifndef CONFIG_64BIT
 292/*
 293 * this function sends a 'purge tlb' signal to another CPU.
 294 */
 295static void smp_ptlb_callback(void *info)
 296{
 297        __tlb_flush_local();
 298}
 299
 300void smp_ptlb_all(void)
 301{
 302        on_each_cpu(smp_ptlb_callback, NULL, 1);
 303}
 304EXPORT_SYMBOL(smp_ptlb_all);
 305#endif /* ! CONFIG_64BIT */
 306
 307/*
 308 * this function sends a 'reschedule' IPI to another CPU.
 309 * it goes straight through and wastes no time serializing
 310 * anything. Worst case is that we lose a reschedule ...
 311 */
 312void smp_send_reschedule(int cpu)
 313{
 314        smp_ext_bitcall(cpu, ec_schedule);
 315}
 316
 317/*
 318 * parameter area for the set/clear control bit callbacks
 319 */
 320struct ec_creg_mask_parms {
 321        unsigned long orvals[16];
 322        unsigned long andvals[16];
 323};
 324
 325/*
 326 * callback for setting/clearing control bits
 327 */
 328static void smp_ctl_bit_callback(void *info)
 329{
 330        struct ec_creg_mask_parms *pp = info;
 331        unsigned long cregs[16];
 332        int i;
 333
 334        __ctl_store(cregs, 0, 15);
 335        for (i = 0; i <= 15; i++)
 336                cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
 337        __ctl_load(cregs, 0, 15);
 338}
 339
 340/*
 341 * Set a bit in a control register of all cpus
 342 */
 343void smp_ctl_set_bit(int cr, int bit)
 344{
 345        struct ec_creg_mask_parms parms;
 346
 347        memset(&parms.orvals, 0, sizeof(parms.orvals));
 348        memset(&parms.andvals, 0xff, sizeof(parms.andvals));
 349        parms.orvals[cr] = 1 << bit;
 350        on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 351}
 352EXPORT_SYMBOL(smp_ctl_set_bit);
 353
 354/*
 355 * Clear a bit in a control register of all cpus
 356 */
 357void smp_ctl_clear_bit(int cr, int bit)
 358{
 359        struct ec_creg_mask_parms parms;
 360
 361        memset(&parms.orvals, 0, sizeof(parms.orvals));
 362        memset(&parms.andvals, 0xff, sizeof(parms.andvals));
 363        parms.andvals[cr] = ~(1L << bit);
 364        on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 365}
 366EXPORT_SYMBOL(smp_ctl_clear_bit);
 367
 368/*
 369 * In early ipl state a temp. logically cpu number is needed, so the sigp
 370 * functions can be used to sense other cpus. Since NR_CPUS is >= 2 on
 371 * CONFIG_SMP and the ipl cpu is logical cpu 0, it must be 1.
 372 */
 373#define CPU_INIT_NO     1
 374
 375#if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_ZFCPDUMP_MODULE)
 376
 377/*
 378 * zfcpdump_prefix_array holds prefix registers for the following scenario:
 379 * 64 bit zfcpdump kernel and 31 bit kernel which is to be dumped. We have to
 380 * save its prefix registers, since they get lost, when switching from 31 bit
 381 * to 64 bit.
 382 */
 383unsigned int zfcpdump_prefix_array[NR_CPUS + 1] \
 384        __attribute__((__section__(".data")));
 385
 386static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
 387{
 388        if (ipl_info.type != IPL_TYPE_FCP_DUMP)
 389                return;
 390        if (cpu >= NR_CPUS) {
 391                printk(KERN_WARNING "Registers for cpu %i not saved since dump "
 392                       "kernel was compiled with NR_CPUS=%i\n", cpu, NR_CPUS);
 393                return;
 394        }
 395        zfcpdump_save_areas[cpu] = kmalloc(sizeof(union save_area), GFP_KERNEL);
 396        __cpu_logical_map[CPU_INIT_NO] = (__u16) phy_cpu;
 397        while (signal_processor(CPU_INIT_NO, sigp_stop_and_store_status) ==
 398               sigp_busy)
 399                cpu_relax();
 400        memcpy(zfcpdump_save_areas[cpu],
 401               (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
 402               SAVE_AREA_SIZE);
 403#ifdef CONFIG_64BIT
 404        /* copy original prefix register */
 405        zfcpdump_save_areas[cpu]->s390x.pref_reg = zfcpdump_prefix_array[cpu];
 406#endif
 407}
 408
 409union save_area *zfcpdump_save_areas[NR_CPUS + 1];
 410EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
 411
 412#else
 413
 414static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
 415
 416#endif /* CONFIG_ZFCPDUMP || CONFIG_ZFCPDUMP_MODULE */
 417
 418static int cpu_stopped(int cpu)
 419{
 420        __u32 status;
 421
 422        /* Check for stopped state */
 423        if (signal_processor_ps(&status, 0, cpu, sigp_sense) ==
 424            sigp_status_stored) {
 425                if (status & 0x40)
 426                        return 1;
 427        }
 428        return 0;
 429}
 430
 431static int cpu_known(int cpu_id)
 432{
 433        int cpu;
 434
 435        for_each_present_cpu(cpu) {
 436                if (__cpu_logical_map[cpu] == cpu_id)
 437                        return 1;
 438        }
 439        return 0;
 440}
 441
 442static int smp_rescan_cpus_sigp(cpumask_t avail)
 443{
 444        int cpu_id, logical_cpu;
 445
 446        logical_cpu = first_cpu(avail);
 447        if (logical_cpu == NR_CPUS)
 448                return 0;
 449        for (cpu_id = 0; cpu_id <= 65535; cpu_id++) {
 450                if (cpu_known(cpu_id))
 451                        continue;
 452                __cpu_logical_map[logical_cpu] = cpu_id;
 453                smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
 454                if (!cpu_stopped(logical_cpu))
 455                        continue;
 456                cpu_set(logical_cpu, cpu_present_map);
 457                smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
 458                logical_cpu = next_cpu(logical_cpu, avail);
 459                if (logical_cpu == NR_CPUS)
 460                        break;
 461        }
 462        return 0;
 463}
 464
 465static int smp_rescan_cpus_sclp(cpumask_t avail)
 466{
 467        struct sclp_cpu_info *info;
 468        int cpu_id, logical_cpu, cpu;
 469        int rc;
 470
 471        logical_cpu = first_cpu(avail);
 472        if (logical_cpu == NR_CPUS)
 473                return 0;
 474        info = kmalloc(sizeof(*info), GFP_KERNEL);
 475        if (!info)
 476                return -ENOMEM;
 477        rc = sclp_get_cpu_info(info);
 478        if (rc)
 479                goto out;
 480        for (cpu = 0; cpu < info->combined; cpu++) {
 481                if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
 482                        continue;
 483                cpu_id = info->cpu[cpu].address;
 484                if (cpu_known(cpu_id))
 485                        continue;
 486                __cpu_logical_map[logical_cpu] = cpu_id;
 487                smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
 488                cpu_set(logical_cpu, cpu_present_map);
 489                if (cpu >= info->configured)
 490                        smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
 491                else
 492                        smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
 493                logical_cpu = next_cpu(logical_cpu, avail);
 494                if (logical_cpu == NR_CPUS)
 495                        break;
 496        }
 497out:
 498        kfree(info);
 499        return rc;
 500}
 501
 502static int __smp_rescan_cpus(void)
 503{
 504        cpumask_t avail;
 505
 506        cpus_xor(avail, cpu_possible_map, cpu_present_map);
 507        if (smp_use_sigp_detection)
 508                return smp_rescan_cpus_sigp(avail);
 509        else
 510                return smp_rescan_cpus_sclp(avail);
 511}
 512
 513static void __init smp_detect_cpus(void)
 514{
 515        unsigned int cpu, c_cpus, s_cpus;
 516        struct sclp_cpu_info *info;
 517        u16 boot_cpu_addr, cpu_addr;
 518
 519        c_cpus = 1;
 520        s_cpus = 0;
 521        boot_cpu_addr = S390_lowcore.cpu_data.cpu_addr;
 522        info = kmalloc(sizeof(*info), GFP_KERNEL);
 523        if (!info)
 524                panic("smp_detect_cpus failed to allocate memory\n");
 525        /* Use sigp detection algorithm if sclp doesn't work. */
 526        if (sclp_get_cpu_info(info)) {
 527                smp_use_sigp_detection = 1;
 528                for (cpu = 0; cpu <= 65535; cpu++) {
 529                        if (cpu == boot_cpu_addr)
 530                                continue;
 531                        __cpu_logical_map[CPU_INIT_NO] = cpu;
 532                        if (!cpu_stopped(CPU_INIT_NO))
 533                                continue;
 534                        smp_get_save_area(c_cpus, cpu);
 535                        c_cpus++;
 536                }
 537                goto out;
 538        }
 539
 540        if (info->has_cpu_type) {
 541                for (cpu = 0; cpu < info->combined; cpu++) {
 542                        if (info->cpu[cpu].address == boot_cpu_addr) {
 543                                smp_cpu_type = info->cpu[cpu].type;
 544                                break;
 545                        }
 546                }
 547        }
 548
 549        for (cpu = 0; cpu < info->combined; cpu++) {
 550                if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
 551                        continue;
 552                cpu_addr = info->cpu[cpu].address;
 553                if (cpu_addr == boot_cpu_addr)
 554                        continue;
 555                __cpu_logical_map[CPU_INIT_NO] = cpu_addr;
 556                if (!cpu_stopped(CPU_INIT_NO)) {
 557                        s_cpus++;
 558                        continue;
 559                }
 560                smp_get_save_area(c_cpus, cpu_addr);
 561                c_cpus++;
 562        }
 563out:
 564        kfree(info);
 565        printk(KERN_INFO "CPUs: %d configured, %d standby\n", c_cpus, s_cpus);
 566        get_online_cpus();
 567        __smp_rescan_cpus();
 568        put_online_cpus();
 569}
 570
 571/*
 572 *      Activate a secondary processor.
 573 */
 574int __cpuinit start_secondary(void *cpuvoid)
 575{
 576        /* Setup the cpu */
 577        cpu_init();
 578        preempt_disable();
 579        /* Enable TOD clock interrupts on the secondary cpu. */
 580        init_cpu_timer();
 581#ifdef CONFIG_VIRT_TIMER
 582        /* Enable cpu timer interrupts on the secondary cpu. */
 583        init_cpu_vtimer();
 584#endif
 585        /* Enable pfault pseudo page faults on this cpu. */
 586        pfault_init();
 587
 588        /* call cpu notifiers */
 589        notify_cpu_starting(smp_processor_id());
 590        /* Mark this cpu as online */
 591        spin_lock(&call_lock);
 592        cpu_set(smp_processor_id(), cpu_online_map);
 593        spin_unlock(&call_lock);
 594        /* Switch on interrupts */
 595        local_irq_enable();
 596        /* Print info about this processor */
 597        print_cpu_info(&S390_lowcore.cpu_data);
 598        /* cpu_idle will call schedule for us */
 599        cpu_idle();
 600        return 0;
 601}
 602
 603static void __init smp_create_idle(unsigned int cpu)
 604{
 605        struct task_struct *p;
 606
 607        /*
 608         *  don't care about the psw and regs settings since we'll never
 609         *  reschedule the forked task.
 610         */
 611        p = fork_idle(cpu);
 612        if (IS_ERR(p))
 613                panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
 614        current_set[cpu] = p;
 615}
 616
 617static int __cpuinit smp_alloc_lowcore(int cpu)
 618{
 619        unsigned long async_stack, panic_stack;
 620        struct _lowcore *lowcore;
 621        int lc_order;
 622
 623        lc_order = sizeof(long) == 8 ? 1 : 0;
 624        lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, lc_order);
 625        if (!lowcore)
 626                return -ENOMEM;
 627        async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
 628        panic_stack = __get_free_page(GFP_KERNEL);
 629        if (!panic_stack || !async_stack)
 630                goto out;
 631        memcpy(lowcore, &S390_lowcore, 512);
 632        memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
 633        lowcore->async_stack = async_stack + ASYNC_SIZE;
 634        lowcore->panic_stack = panic_stack + PAGE_SIZE;
 635
 636#ifndef CONFIG_64BIT
 637        if (MACHINE_HAS_IEEE) {
 638                unsigned long save_area;
 639
 640                save_area = get_zeroed_page(GFP_KERNEL);
 641                if (!save_area)
 642                        goto out_save_area;
 643                lowcore->extended_save_area_addr = (u32) save_area;
 644        }
 645#endif
 646        lowcore_ptr[cpu] = lowcore;
 647        return 0;
 648
 649#ifndef CONFIG_64BIT
 650out_save_area:
 651        free_page(panic_stack);
 652#endif
 653out:
 654        free_pages(async_stack, ASYNC_ORDER);
 655        free_pages((unsigned long) lowcore, lc_order);
 656        return -ENOMEM;
 657}
 658
 659#ifdef CONFIG_HOTPLUG_CPU
 660static void smp_free_lowcore(int cpu)
 661{
 662        struct _lowcore *lowcore;
 663        int lc_order;
 664
 665        lc_order = sizeof(long) == 8 ? 1 : 0;
 666        lowcore = lowcore_ptr[cpu];
 667#ifndef CONFIG_64BIT
 668        if (MACHINE_HAS_IEEE)
 669                free_page((unsigned long) lowcore->extended_save_area_addr);
 670#endif
 671        free_page(lowcore->panic_stack - PAGE_SIZE);
 672        free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
 673        free_pages((unsigned long) lowcore, lc_order);
 674        lowcore_ptr[cpu] = NULL;
 675}
 676#endif /* CONFIG_HOTPLUG_CPU */
 677
 678/* Upping and downing of CPUs */
 679int __cpuinit __cpu_up(unsigned int cpu)
 680{
 681        struct task_struct *idle;
 682        struct _lowcore *cpu_lowcore;
 683        struct stack_frame *sf;
 684        sigp_ccode ccode;
 685
 686        if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
 687                return -EIO;
 688        if (smp_alloc_lowcore(cpu))
 689                return -ENOMEM;
 690
 691        ccode = signal_processor_p((__u32)(unsigned long)(lowcore_ptr[cpu]),
 692                                   cpu, sigp_set_prefix);
 693        if (ccode) {
 694                printk("sigp_set_prefix failed for cpu %d "
 695                       "with condition code %d\n",
 696                       (int) cpu, (int) ccode);
 697                return -EIO;
 698        }
 699
 700        idle = current_set[cpu];
 701        cpu_lowcore = lowcore_ptr[cpu];
 702        cpu_lowcore->kernel_stack = (unsigned long)
 703                task_stack_page(idle) + THREAD_SIZE;
 704        cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
 705        sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
 706                                     - sizeof(struct pt_regs)
 707                                     - sizeof(struct stack_frame));
 708        memset(sf, 0, sizeof(struct stack_frame));
 709        sf->gprs[9] = (unsigned long) sf;
 710        cpu_lowcore->save_area[15] = (unsigned long) sf;
 711        __ctl_store(cpu_lowcore->cregs_save_area, 0, 15);
 712        asm volatile(
 713                "       stam    0,15,0(%0)"
 714                : : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
 715        cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
 716        cpu_lowcore->current_task = (unsigned long) idle;
 717        cpu_lowcore->cpu_data.cpu_nr = cpu;
 718        cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
 719        cpu_lowcore->ipl_device = S390_lowcore.ipl_device;
 720        eieio();
 721
 722        while (signal_processor(cpu, sigp_restart) == sigp_busy)
 723                udelay(10);
 724
 725        while (!cpu_online(cpu))
 726                cpu_relax();
 727        return 0;
 728}
 729
 730static int __init setup_possible_cpus(char *s)
 731{
 732        int pcpus, cpu;
 733
 734        pcpus = simple_strtoul(s, NULL, 0);
 735        cpu_possible_map = cpumask_of_cpu(0);
 736        for (cpu = 1; cpu < pcpus && cpu < NR_CPUS; cpu++)
 737                cpu_set(cpu, cpu_possible_map);
 738        return 0;
 739}
 740early_param("possible_cpus", setup_possible_cpus);
 741
 742#ifdef CONFIG_HOTPLUG_CPU
 743
 744int __cpu_disable(void)
 745{
 746        struct ec_creg_mask_parms cr_parms;
 747        int cpu = smp_processor_id();
 748
 749        cpu_clear(cpu, cpu_online_map);
 750
 751        /* Disable pfault pseudo page faults on this cpu. */
 752        pfault_fini();
 753
 754        memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
 755        memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
 756
 757        /* disable all external interrupts */
 758        cr_parms.orvals[0] = 0;
 759        cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 12 |
 760                                1 << 11 | 1 << 10 | 1 <<  6 | 1 <<  4);
 761        /* disable all I/O interrupts */
 762        cr_parms.orvals[6] = 0;
 763        cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
 764                                1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
 765        /* disable most machine checks */
 766        cr_parms.orvals[14] = 0;
 767        cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
 768                                 1 << 25 | 1 << 24);
 769
 770        smp_ctl_bit_callback(&cr_parms);
 771
 772        return 0;
 773}
 774
 775void __cpu_die(unsigned int cpu)
 776{
 777        /* Wait until target cpu is down */
 778        while (!smp_cpu_not_running(cpu))
 779                cpu_relax();
 780        smp_free_lowcore(cpu);
 781        printk(KERN_INFO "Processor %d spun down\n", cpu);
 782}
 783
 784void cpu_die(void)
 785{
 786        idle_task_exit();
 787        signal_processor(smp_processor_id(), sigp_stop);
 788        BUG();
 789        for (;;);
 790}
 791
 792#endif /* CONFIG_HOTPLUG_CPU */
 793
 794void __init smp_prepare_cpus(unsigned int max_cpus)
 795{
 796#ifndef CONFIG_64BIT
 797        unsigned long save_area = 0;
 798#endif
 799        unsigned long async_stack, panic_stack;
 800        struct _lowcore *lowcore;
 801        unsigned int cpu;
 802        int lc_order;
 803
 804        smp_detect_cpus();
 805
 806        /* request the 0x1201 emergency signal external interrupt */
 807        if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
 808                panic("Couldn't request external interrupt 0x1201");
 809        print_cpu_info(&S390_lowcore.cpu_data);
 810
 811        /* Reallocate current lowcore, but keep its contents. */
 812        lc_order = sizeof(long) == 8 ? 1 : 0;
 813        lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, lc_order);
 814        panic_stack = __get_free_page(GFP_KERNEL);
 815        async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
 816#ifndef CONFIG_64BIT
 817        if (MACHINE_HAS_IEEE)
 818                save_area = get_zeroed_page(GFP_KERNEL);
 819#endif
 820        local_irq_disable();
 821        local_mcck_disable();
 822        lowcore_ptr[smp_processor_id()] = lowcore;
 823        *lowcore = S390_lowcore;
 824        lowcore->panic_stack = panic_stack + PAGE_SIZE;
 825        lowcore->async_stack = async_stack + ASYNC_SIZE;
 826#ifndef CONFIG_64BIT
 827        if (MACHINE_HAS_IEEE)
 828                lowcore->extended_save_area_addr = (u32) save_area;
 829#endif
 830        set_prefix((u32)(unsigned long) lowcore);
 831        local_mcck_enable();
 832        local_irq_enable();
 833        for_each_possible_cpu(cpu)
 834                if (cpu != smp_processor_id())
 835                        smp_create_idle(cpu);
 836}
 837
 838void __init smp_prepare_boot_cpu(void)
 839{
 840        BUG_ON(smp_processor_id() != 0);
 841
 842        current_thread_info()->cpu = 0;
 843        cpu_set(0, cpu_present_map);
 844        cpu_set(0, cpu_online_map);
 845        S390_lowcore.percpu_offset = __per_cpu_offset[0];
 846        current_set[0] = current;
 847        smp_cpu_state[0] = CPU_STATE_CONFIGURED;
 848        smp_cpu_polarization[0] = POLARIZATION_UNKNWN;
 849}
 850
 851void __init smp_cpus_done(unsigned int max_cpus)
 852{
 853}
 854
 855/*
 856 * the frequency of the profiling timer can be changed
 857 * by writing a multiplier value into /proc/profile.
 858 *
 859 * usually you want to run this on all CPUs ;)
 860 */
 861int setup_profiling_timer(unsigned int multiplier)
 862{
 863        return 0;
 864}
 865
 866#ifdef CONFIG_HOTPLUG_CPU
 867static ssize_t cpu_configure_show(struct sys_device *dev,
 868                                struct sysdev_attribute *attr, char *buf)
 869{
 870        ssize_t count;
 871
 872        mutex_lock(&smp_cpu_state_mutex);
 873        count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
 874        mutex_unlock(&smp_cpu_state_mutex);
 875        return count;
 876}
 877
 878static ssize_t cpu_configure_store(struct sys_device *dev,
 879                                  struct sysdev_attribute *attr,
 880                                  const char *buf, size_t count)
 881{
 882        int cpu = dev->id;
 883        int val, rc;
 884        char delim;
 885
 886        if (sscanf(buf, "%d %c", &val, &delim) != 1)
 887                return -EINVAL;
 888        if (val != 0 && val != 1)
 889                return -EINVAL;
 890
 891        get_online_cpus();
 892        mutex_lock(&smp_cpu_state_mutex);
 893        rc = -EBUSY;
 894        if (cpu_online(cpu))
 895                goto out;
 896        rc = 0;
 897        switch (val) {
 898        case 0:
 899                if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
 900                        rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
 901                        if (!rc) {
 902                                smp_cpu_state[cpu] = CPU_STATE_STANDBY;
 903                                smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 904                        }
 905                }
 906                break;
 907        case 1:
 908                if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
 909                        rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
 910                        if (!rc) {
 911                                smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
 912                                smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 913                        }
 914                }
 915                break;
 916        default:
 917                break;
 918        }
 919out:
 920        mutex_unlock(&smp_cpu_state_mutex);
 921        put_online_cpus();
 922        return rc ? rc : count;
 923}
 924static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
 925#endif /* CONFIG_HOTPLUG_CPU */
 926
 927static ssize_t cpu_polarization_show(struct sys_device *dev,
 928                                     struct sysdev_attribute *attr, char *buf)
 929{
 930        int cpu = dev->id;
 931        ssize_t count;
 932
 933        mutex_lock(&smp_cpu_state_mutex);
 934        switch (smp_cpu_polarization[cpu]) {
 935        case POLARIZATION_HRZ:
 936                count = sprintf(buf, "horizontal\n");
 937                break;
 938        case POLARIZATION_VL:
 939                count = sprintf(buf, "vertical:low\n");
 940                break;
 941        case POLARIZATION_VM:
 942                count = sprintf(buf, "vertical:medium\n");
 943                break;
 944        case POLARIZATION_VH:
 945                count = sprintf(buf, "vertical:high\n");
 946                break;
 947        default:
 948                count = sprintf(buf, "unknown\n");
 949                break;
 950        }
 951        mutex_unlock(&smp_cpu_state_mutex);
 952        return count;
 953}
 954static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL);
 955
 956static ssize_t show_cpu_address(struct sys_device *dev,
 957                                struct sysdev_attribute *attr, char *buf)
 958{
 959        return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
 960}
 961static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
 962
 963
 964static struct attribute *cpu_common_attrs[] = {
 965#ifdef CONFIG_HOTPLUG_CPU
 966        &attr_configure.attr,
 967#endif
 968        &attr_address.attr,
 969        &attr_polarization.attr,
 970        NULL,
 971};
 972
 973static struct attribute_group cpu_common_attr_group = {
 974        .attrs = cpu_common_attrs,
 975};
 976
 977static ssize_t show_capability(struct sys_device *dev,
 978                                struct sysdev_attribute *attr, char *buf)
 979{
 980        unsigned int capability;
 981        int rc;
 982
 983        rc = get_cpu_capability(&capability);
 984        if (rc)
 985                return rc;
 986        return sprintf(buf, "%u\n", capability);
 987}
 988static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
 989
 990static ssize_t show_idle_count(struct sys_device *dev,
 991                                struct sysdev_attribute *attr, char *buf)
 992{
 993        struct s390_idle_data *idle;
 994        unsigned long long idle_count;
 995
 996        idle = &per_cpu(s390_idle, dev->id);
 997        spin_lock_irq(&idle->lock);
 998        idle_count = idle->idle_count;
 999        spin_unlock_irq(&idle->lock);
1000        return sprintf(buf, "%llu\n", idle_count);
1001}
1002static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL);
1003
1004static ssize_t show_idle_time(struct sys_device *dev,
1005                                struct sysdev_attribute *attr, char *buf)
1006{
1007        struct s390_idle_data *idle;
1008        unsigned long long new_time;
1009
1010        idle = &per_cpu(s390_idle, dev->id);
1011        spin_lock_irq(&idle->lock);
1012        if (idle->in_idle) {
1013                new_time = get_clock();
1014                idle->idle_time += new_time - idle->idle_enter;
1015                idle->idle_enter = new_time;
1016        }
1017        new_time = idle->idle_time;
1018        spin_unlock_irq(&idle->lock);
1019        return sprintf(buf, "%llu\n", new_time >> 12);
1020}
1021static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
1022
1023static struct attribute *cpu_online_attrs[] = {
1024        &attr_capability.attr,
1025        &attr_idle_count.attr,
1026        &attr_idle_time_us.attr,
1027        NULL,
1028};
1029
1030static struct attribute_group cpu_online_attr_group = {
1031        .attrs = cpu_online_attrs,
1032};
1033
1034static int __cpuinit smp_cpu_notify(struct notifier_block *self,
1035                                    unsigned long action, void *hcpu)
1036{
1037        unsigned int cpu = (unsigned int)(long)hcpu;
1038        struct cpu *c = &per_cpu(cpu_devices, cpu);
1039        struct sys_device *s = &c->sysdev;
1040        struct s390_idle_data *idle;
1041
1042        switch (action) {
1043        case CPU_ONLINE:
1044        case CPU_ONLINE_FROZEN:
1045                idle = &per_cpu(s390_idle, cpu);
1046                spin_lock_irq(&idle->lock);
1047                idle->idle_enter = 0;
1048                idle->idle_time = 0;
1049                idle->idle_count = 0;
1050                spin_unlock_irq(&idle->lock);
1051                if (sysfs_create_group(&s->kobj, &cpu_online_attr_group))
1052                        return NOTIFY_BAD;
1053                break;
1054        case CPU_DEAD:
1055        case CPU_DEAD_FROZEN:
1056                sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1057                break;
1058        }
1059        return NOTIFY_OK;
1060}
1061
1062static struct notifier_block __cpuinitdata smp_cpu_nb = {
1063        .notifier_call = smp_cpu_notify,
1064};
1065
1066static int __devinit smp_add_present_cpu(int cpu)
1067{
1068        struct cpu *c = &per_cpu(cpu_devices, cpu);
1069        struct sys_device *s = &c->sysdev;
1070        int rc;
1071
1072        c->hotpluggable = 1;
1073        rc = register_cpu(c, cpu);
1074        if (rc)
1075                goto out;
1076        rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1077        if (rc)
1078                goto out_cpu;
1079        if (!cpu_online(cpu))
1080                goto out;
1081        rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1082        if (!rc)
1083                return 0;
1084        sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1085out_cpu:
1086#ifdef CONFIG_HOTPLUG_CPU
1087        unregister_cpu(c);
1088#endif
1089out:
1090        return rc;
1091}
1092
1093#ifdef CONFIG_HOTPLUG_CPU
1094
1095int __ref smp_rescan_cpus(void)
1096{
1097        cpumask_t newcpus;
1098        int cpu;
1099        int rc;
1100
1101        get_online_cpus();
1102        mutex_lock(&smp_cpu_state_mutex);
1103        newcpus = cpu_present_map;
1104        rc = __smp_rescan_cpus();
1105        if (rc)
1106                goto out;
1107        cpus_andnot(newcpus, cpu_present_map, newcpus);
1108        for_each_cpu_mask(cpu, newcpus) {
1109                rc = smp_add_present_cpu(cpu);
1110                if (rc)
1111                        cpu_clear(cpu, cpu_present_map);
1112        }
1113        rc = 0;
1114out:
1115        mutex_unlock(&smp_cpu_state_mutex);
1116        put_online_cpus();
1117        if (!cpus_empty(newcpus))
1118                topology_schedule_update();
1119        return rc;
1120}
1121
1122static ssize_t __ref rescan_store(struct sysdev_class *class, const char *buf,
1123                                  size_t count)
1124{
1125        int rc;
1126
1127        rc = smp_rescan_cpus();
1128        return rc ? rc : count;
1129}
1130static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store);
1131#endif /* CONFIG_HOTPLUG_CPU */
1132
1133static ssize_t dispatching_show(struct sysdev_class *class, char *buf)
1134{
1135        ssize_t count;
1136
1137        mutex_lock(&smp_cpu_state_mutex);
1138        count = sprintf(buf, "%d\n", cpu_management);
1139        mutex_unlock(&smp_cpu_state_mutex);
1140        return count;
1141}
1142
1143static ssize_t dispatching_store(struct sysdev_class *dev, const char *buf,
1144                                 size_t count)
1145{
1146        int val, rc;
1147        char delim;
1148
1149        if (sscanf(buf, "%d %c", &val, &delim) != 1)
1150                return -EINVAL;
1151        if (val != 0 && val != 1)
1152                return -EINVAL;
1153        rc = 0;
1154        get_online_cpus();
1155        mutex_lock(&smp_cpu_state_mutex);
1156        if (cpu_management == val)
1157                goto out;
1158        rc = topology_set_cpu_management(val);
1159        if (!rc)
1160                cpu_management = val;
1161out:
1162        mutex_unlock(&smp_cpu_state_mutex);
1163        put_online_cpus();
1164        return rc ? rc : count;
1165}
1166static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
1167                         dispatching_store);
1168
1169static int __init topology_init(void)
1170{
1171        int cpu;
1172        int rc;
1173
1174        register_cpu_notifier(&smp_cpu_nb);
1175
1176#ifdef CONFIG_HOTPLUG_CPU
1177        rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan);
1178        if (rc)
1179                return rc;
1180#endif
1181        rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching);
1182        if (rc)
1183                return rc;
1184        for_each_present_cpu(cpu) {
1185                rc = smp_add_present_cpu(cpu);
1186                if (rc)
1187                        return rc;
1188        }
1189        return 0;
1190}
1191subsys_initcall(topology_init);
1192