arch/s390/kernel/smp.c

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