arch/s390/kernel/smp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  SMP related functions
   4  *
   5  *    Copyright IBM Corp. 1999, 2012
   6  *    Author(s): Denis Joseph Barrow,
   7  *               Martin Schwidefsky <schwidefsky@de.ibm.com>,
   8  *               Heiko Carstens <heiko.carstens@de.ibm.com>,
   9  *
  10  *  based on other smp stuff by
  11  *    (c) 1995 Alan Cox, CymruNET Ltd  <alan@cymru.net>
  12  *    (c) 1998 Ingo Molnar
  13  *
  14  * The code outside of smp.c uses logical cpu numbers, only smp.c does
  15  * the translation of logical to physical cpu ids. All new code that
  16  * operates on physical cpu numbers needs to go into smp.c.
  17  */
  18
  19 #define KMSG_COMPONENT "cpu"
  20 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  21
  22 #include <linux/workqueue.h>
  23 #include <linux/memblock.h>
  24 #include <linux/export.h>
  25 #include <linux/init.h>
  26 #include <linux/mm.h>
  27 #include <linux/err.h>
  28 #include <linux/spinlock.h>
  29 #include <linux/kernel_stat.h>
  30 #include <linux/delay.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/irqflags.h>
  33 #include <linux/cpu.h>
  34 #include <linux/slab.h>
  35 #include <linux/sched/hotplug.h>
  36 #include <linux/sched/task_stack.h>
  37 #include <linux/crash_dump.h>
  38 #include <linux/kprobes.h>
  39 #include <asm/asm-offsets.h>
  40 #include <asm/diag.h>
  41 #include <asm/switch_to.h>
  42 #include <asm/facility.h>
  43 #include <asm/ipl.h>
  44 #include <asm/setup.h>
  45 #include <asm/irq.h>
  46 #include <asm/tlbflush.h>
  47 #include <asm/vtimer.h>
  48 #include <asm/lowcore.h>
  49 #include <asm/sclp.h>
  50 #include <asm/vdso.h>
  51 #include <asm/debug.h>
  52 #include <asm/os_info.h>
  53 #include <asm/sigp.h>
  54 #include <asm/idle.h>
  55 #include <asm/nmi.h>
  56 #include <asm/stacktrace.h>
  57 #include <asm/topology.h>
  58 #include "entry.h"
  59
  60 enum {
  61         ec_schedule = 0,
  62         ec_call_function_single,
  63         ec_stop_cpu,
  64 };
  65
  66 enum {
  67         CPU_STATE_STANDBY,
  68         CPU_STATE_CONFIGURED,
  69 };
  70
  71 static DEFINE_PER_CPU(struct cpu *, cpu_device);
  72
  73 struct pcpu {
  74         struct lowcore *lowcore;        /* lowcore page(s) for the cpu */
  75         unsigned long ec_mask;          /* bit mask for ec_xxx functions */
  76         unsigned long ec_clk;           /* sigp timestamp for ec_xxx */
  77         signed char state;              /* physical cpu state */
  78         signed char polarization;       /* physical polarization */
  79         u16 address;                    /* physical cpu address */
  80 };
  81
  82 static u8 boot_core_type;
  83 static struct pcpu pcpu_devices[NR_CPUS];
  84
  85 unsigned int smp_cpu_mt_shift;
  86 EXPORT_SYMBOL(smp_cpu_mt_shift);
  87
  88 unsigned int smp_cpu_mtid;
  89 EXPORT_SYMBOL(smp_cpu_mtid);
  90
  91 #ifdef CONFIG_CRASH_DUMP
  92 __vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
  93 #endif
  94
  95 static unsigned int smp_max_threads __initdata = -1U;
  96
  97 static int __init early_nosmt(char *s)
  98 {
  99         smp_max_threads = 1;
 100         return 0;
 101 }
 102 early_param("nosmt", early_nosmt);
 103
 104 static int __init early_smt(char *s)
 105 {
 106         get_option(&s, &smp_max_threads);
 107         return 0;
 108 }
 109 early_param("smt", early_smt);
 110
 111 /*
 112  * The smp_cpu_state_mutex must be held when changing the state or polarization
 113  * member of a pcpu data structure within the pcpu_devices arreay.
 114  */
 115 DEFINE_MUTEX(smp_cpu_state_mutex);
 116
 117 /*
 118  * Signal processor helper functions.
 119  */
 120 static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm)
 121 {
 122         int cc;
 123
 124         while (1) {
 125                 cc = __pcpu_sigp(addr, order, parm, NULL);
 126                 if (cc != SIGP_CC_BUSY)
 127                         return cc;
 128                 cpu_relax();
 129         }
 130 }
 131
 132 static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
 133 {
 134         int cc, retry;
 135
 136         for (retry = 0; ; retry++) {
 137                 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
 138                 if (cc != SIGP_CC_BUSY)
 139                         break;
 140                 if (retry >= 3)
 141                         udelay(10);
 142         }
 143         return cc;
 144 }
 145
 146 static inline int pcpu_stopped(struct pcpu *pcpu)
 147 {
 148         u32 uninitialized_var(status);
 149
 150         if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
 151                         0, &status) != SIGP_CC_STATUS_STORED)
 152                 return 0;
 153         return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
 154 }
 155
 156 static inline int pcpu_running(struct pcpu *pcpu)
 157 {
 158         if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
 159                         0, NULL) != SIGP_CC_STATUS_STORED)
 160                 return 1;
 161         /* Status stored condition code is equivalent to cpu not running. */
 162         return 0;
 163 }
 164
 165 /*
 166  * Find struct pcpu by cpu address.
 167  */
 168 static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address)
 169 {
 170         int cpu;
 171
 172         for_each_cpu(cpu, mask)
 173                 if (pcpu_devices[cpu].address == address)
 174                         return pcpu_devices + cpu;
 175         return NULL;
 176 }
 177
 178 static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
 179 {
 180         int order;
 181
 182         if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
 183                 return;
 184         order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
 185         pcpu->ec_clk = get_tod_clock_fast();
 186         pcpu_sigp_retry(pcpu, order, 0);
 187 }
 188
 189 static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
 190 {
 191         unsigned long async_stack, nodat_stack;
 192         struct lowcore *lc;
 193
 194         if (pcpu != &pcpu_devices[0]) {
 195                 pcpu->lowcore = (struct lowcore *)
 196                         __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
 197                 nodat_stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
 198                 if (!pcpu->lowcore || !nodat_stack)
 199                         goto out;
 200         } else {
 201                 nodat_stack = pcpu->lowcore->nodat_stack - STACK_INIT_OFFSET;
 202         }
 203         async_stack = stack_alloc();
 204         if (!async_stack)
 205                 goto out;
 206         lc = pcpu->lowcore;
 207         memcpy(lc, &S390_lowcore, 512);
 208         memset((char *) lc + 512, 0, sizeof(*lc) - 512);
 209         lc->async_stack = async_stack + STACK_INIT_OFFSET;
 210         lc->nodat_stack = nodat_stack + STACK_INIT_OFFSET;
 211         lc->cpu_nr = cpu;
 212         lc->spinlock_lockval = arch_spin_lockval(cpu);
 213         lc->spinlock_index = 0;
 214         lc->br_r1_trampoline = 0x07f1;  /* br %r1 */
 215         if (nmi_alloc_per_cpu(lc))
 216                 goto out_async;
 217         if (vdso_alloc_per_cpu(lc))
 218                 goto out_mcesa;
 219         lowcore_ptr[cpu] = lc;
 220         pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
 221         return 0;
 222
 223 out_mcesa:
 224         nmi_free_per_cpu(lc);
 225 out_async:
 226         stack_free(async_stack);
 227 out:
 228         if (pcpu != &pcpu_devices[0]) {
 229                 free_pages(nodat_stack, THREAD_SIZE_ORDER);
 230                 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
 231         }
 232         return -ENOMEM;
 233 }
 234
 235 #ifdef CONFIG_HOTPLUG_CPU
 236
 237 static void pcpu_free_lowcore(struct pcpu *pcpu)
 238 {
 239         unsigned long async_stack, nodat_stack, lowcore;
 240
 241         nodat_stack = pcpu->lowcore->nodat_stack - STACK_INIT_OFFSET;
 242         async_stack = pcpu->lowcore->async_stack - STACK_INIT_OFFSET;
 243         lowcore = (unsigned long) pcpu->lowcore;
 244
 245         pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
 246         lowcore_ptr[pcpu - pcpu_devices] = NULL;
 247         vdso_free_per_cpu(pcpu->lowcore);
 248         nmi_free_per_cpu(pcpu->lowcore);
 249         stack_free(async_stack);
 250         if (pcpu == &pcpu_devices[0])
 251                 return;
 252         free_pages(nodat_stack, THREAD_SIZE_ORDER);
 253         free_pages(lowcore, LC_ORDER);
 254 }
 255
 256 #endif /* CONFIG_HOTPLUG_CPU */
 257
 258 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
 259 {
 260         struct lowcore *lc = pcpu->lowcore;
 261
 262         cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
 263         cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
 264         lc->cpu_nr = cpu;
 265         lc->spinlock_lockval = arch_spin_lockval(cpu);
 266         lc->spinlock_index = 0;
 267         lc->percpu_offset = __per_cpu_offset[cpu];
 268         lc->kernel_asce = S390_lowcore.kernel_asce;
 269         lc->machine_flags = S390_lowcore.machine_flags;
 270         lc->user_timer = lc->system_timer =
 271                 lc->steal_timer = lc->avg_steal_timer = 0;
 272         __ctl_store(lc->cregs_save_area, 0, 15);
 273         save_access_regs((unsigned int *) lc->access_regs_save_area);
 274         memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
 275                sizeof(lc->stfle_fac_list));
 276         memcpy(lc->alt_stfle_fac_list, S390_lowcore.alt_stfle_fac_list,
 277                sizeof(lc->alt_stfle_fac_list));
 278         arch_spin_lock_setup(cpu);
 279 }
 280
 281 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
 282 {
 283         struct lowcore *lc = pcpu->lowcore;
 284
 285         lc->kernel_stack = (unsigned long) task_stack_page(tsk)
 286                 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 287         lc->current_task = (unsigned long) tsk;
 288         lc->lpp = LPP_MAGIC;
 289         lc->current_pid = tsk->pid;
 290         lc->user_timer = tsk->thread.user_timer;
 291         lc->guest_timer = tsk->thread.guest_timer;
 292         lc->system_timer = tsk->thread.system_timer;
 293         lc->hardirq_timer = tsk->thread.hardirq_timer;
 294         lc->softirq_timer = tsk->thread.softirq_timer;
 295         lc->steal_timer = 0;
 296 }
 297
 298 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
 299 {
 300         struct lowcore *lc = pcpu->lowcore;
 301
 302         lc->restart_stack = lc->nodat_stack;
 303         lc->restart_fn = (unsigned long) func;
 304         lc->restart_data = (unsigned long) data;
 305         lc->restart_source = -1UL;
 306         pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
 307 }
 308
 309 /*
 310  * Call function via PSW restart on pcpu and stop the current cpu.
 311  */
 312 static void __pcpu_delegate(void (*func)(void*), void *data)
 313 {
 314         func(data);     /* should not return */
 315 }
 316
 317 static void __no_sanitize_address pcpu_delegate(struct pcpu *pcpu,
 318                                                 void (*func)(void *),
 319                                                 void *data, unsigned long stack)
 320 {
 321         struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
 322         unsigned long source_cpu = stap();
 323
 324         __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
 325         if (pcpu->address == source_cpu)
 326                 CALL_ON_STACK(__pcpu_delegate, stack, 2, func, data);
 327         /* Stop target cpu (if func returns this stops the current cpu). */
 328         pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
 329         /* Restart func on the target cpu and stop the current cpu. */
 330         mem_assign_absolute(lc->restart_stack, stack);
 331         mem_assign_absolute(lc->restart_fn, (unsigned long) func);
 332         mem_assign_absolute(lc->restart_data, (unsigned long) data);
 333         mem_assign_absolute(lc->restart_source, source_cpu);
 334         __bpon();
 335         asm volatile(
 336                 "0:     sigp    0,%0,%2 # sigp restart to target cpu\n"
 337                 "       brc     2,0b    # busy, try again\n"
 338                 "1:     sigp    0,%1,%3 # sigp stop to current cpu\n"
 339                 "       brc     2,1b    # busy, try again\n"
 340                 : : "d" (pcpu->address), "d" (source_cpu),
 341                     "K" (SIGP_RESTART), "K" (SIGP_STOP)
 342                 : "0", "1", "cc");
 343         for (;;) ;
 344 }
 345
 346 /*
 347  * Enable additional logical cpus for multi-threading.
 348  */
 349 static int pcpu_set_smt(unsigned int mtid)
 350 {
 351         int cc;
 352
 353         if (smp_cpu_mtid == mtid)
 354                 return 0;
 355         cc = __pcpu_sigp(0, SIGP_SET_MULTI_THREADING, mtid, NULL);
 356         if (cc == 0) {
 357                 smp_cpu_mtid = mtid;
 358                 smp_cpu_mt_shift = 0;
 359                 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift))
 360                         smp_cpu_mt_shift++;
 361                 pcpu_devices[0].address = stap();
 362         }
 363         return cc;
 364 }
 365
 366 /*
 367  * Call function on an online CPU.
 368  */
 369 void smp_call_online_cpu(void (*func)(void *), void *data)
 370 {
 371         struct pcpu *pcpu;
 372
 373         /* Use the current cpu if it is online. */
 374         pcpu = pcpu_find_address(cpu_online_mask, stap());
 375         if (!pcpu)
 376                 /* Use the first online cpu. */
 377                 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
 378         pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
 379 }
 380
 381 /*
 382  * Call function on the ipl CPU.
 383  */
 384 void smp_call_ipl_cpu(void (*func)(void *), void *data)
 385 {
 386         struct lowcore *lc = pcpu_devices->lowcore;
 387
 388         if (pcpu_devices[0].address == stap())
 389                 lc = &S390_lowcore;
 390
 391         pcpu_delegate(&pcpu_devices[0], func, data,
 392                       lc->nodat_stack);
 393 }
 394
 395 int smp_find_processor_id(u16 address)
 396 {
 397         int cpu;
 398
 399         for_each_present_cpu(cpu)
 400                 if (pcpu_devices[cpu].address == address)
 401                         return cpu;
 402         return -1;
 403 }
 404
 405 bool arch_vcpu_is_preempted(int cpu)
 406 {
 407         if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu))
 408                 return false;
 409         if (pcpu_running(pcpu_devices + cpu))
 410                 return false;
 411         return true;
 412 }
 413 EXPORT_SYMBOL(arch_vcpu_is_preempted);
 414
 415 void smp_yield_cpu(int cpu)
 416 {
 417         if (MACHINE_HAS_DIAG9C) {
 418                 diag_stat_inc_norecursion(DIAG_STAT_X09C);
 419                 asm volatile("diag %0,0,0x9c"
 420                              : : "d" (pcpu_devices[cpu].address));
 421         } else if (MACHINE_HAS_DIAG44) {
 422                 diag_stat_inc_norecursion(DIAG_STAT_X044);
 423                 asm volatile("diag 0,0,0x44");
 424         }
 425 }
 426
 427 /*
 428  * Send cpus emergency shutdown signal. This gives the cpus the
 429  * opportunity to complete outstanding interrupts.
 430  */
 431 void notrace smp_emergency_stop(void)
 432 {
 433         cpumask_t cpumask;
 434         u64 end;
 435         int cpu;
 436
 437         cpumask_copy(&cpumask, cpu_online_mask);
 438         cpumask_clear_cpu(smp_processor_id(), &cpumask);
 439
 440         end = get_tod_clock() + (1000000UL << 12);
 441         for_each_cpu(cpu, &cpumask) {
 442                 struct pcpu *pcpu = pcpu_devices + cpu;
 443                 set_bit(ec_stop_cpu, &pcpu->ec_mask);
 444                 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
 445                                    0, NULL) == SIGP_CC_BUSY &&
 446                        get_tod_clock() < end)
 447                         cpu_relax();
 448         }
 449         while (get_tod_clock() < end) {
 450                 for_each_cpu(cpu, &cpumask)
 451                         if (pcpu_stopped(pcpu_devices + cpu))
 452                                 cpumask_clear_cpu(cpu, &cpumask);
 453                 if (cpumask_empty(&cpumask))
 454                         break;
 455                 cpu_relax();
 456         }
 457 }
 458 NOKPROBE_SYMBOL(smp_emergency_stop);
 459
 460 /*
 461  * Stop all cpus but the current one.
 462  */
 463 void smp_send_stop(void)
 464 {
 465         int cpu;
 466
 467         /* Disable all interrupts/machine checks */
 468         __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
 469         trace_hardirqs_off();
 470
 471         debug_set_critical();
 472
 473         if (oops_in_progress)
 474                 smp_emergency_stop();
 475
 476         /* stop all processors */
 477         for_each_online_cpu(cpu) {
 478                 if (cpu == smp_processor_id())
 479                         continue;
 480                 pcpu_sigp_retry(pcpu_devices + cpu, SIGP_STOP, 0);
 481                 while (!pcpu_stopped(pcpu_devices + cpu))
 482                         cpu_relax();
 483         }
 484 }
 485
 486 /*
 487  * This is the main routine where commands issued by other
 488  * cpus are handled.
 489  */
 490 static void smp_handle_ext_call(void)
 491 {
 492         unsigned long bits;
 493
 494         /* handle bit signal external calls */
 495         bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
 496         if (test_bit(ec_stop_cpu, &bits))
 497                 smp_stop_cpu();
 498         if (test_bit(ec_schedule, &bits))
 499                 scheduler_ipi();
 500         if (test_bit(ec_call_function_single, &bits))
 501                 generic_smp_call_function_single_interrupt();
 502 }
 503
 504 static void do_ext_call_interrupt(struct ext_code ext_code,
 505                                   unsigned int param32, unsigned long param64)
 506 {
 507         inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
 508         smp_handle_ext_call();
 509 }
 510
 511 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 512 {
 513         int cpu;
 514
 515         for_each_cpu(cpu, mask)
 516                 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
 517 }
 518
 519 void arch_send_call_function_single_ipi(int cpu)
 520 {
 521         pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
 522 }
 523
 524 /*
 525  * this function sends a 'reschedule' IPI to another CPU.
 526  * it goes straight through and wastes no time serializing
 527  * anything. Worst case is that we lose a reschedule ...
 528  */
 529 void smp_send_reschedule(int cpu)
 530 {
 531         pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
 532 }
 533
 534 /*
 535  * parameter area for the set/clear control bit callbacks
 536  */
 537 struct ec_creg_mask_parms {
 538         unsigned long orval;
 539         unsigned long andval;
 540         int cr;
 541 };
 542
 543 /*
 544  * callback for setting/clearing control bits
 545  */
 546 static void smp_ctl_bit_callback(void *info)
 547 {
 548         struct ec_creg_mask_parms *pp = info;
 549         unsigned long cregs[16];
 550
 551         __ctl_store(cregs, 0, 15);
 552         cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
 553         __ctl_load(cregs, 0, 15);
 554 }
 555
 556 /*
 557  * Set a bit in a control register of all cpus
 558  */
 559 void smp_ctl_set_bit(int cr, int bit)
 560 {
 561         struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
 562
 563         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 564 }
 565 EXPORT_SYMBOL(smp_ctl_set_bit);
 566
 567 /*
 568  * Clear a bit in a control register of all cpus
 569  */
 570 void smp_ctl_clear_bit(int cr, int bit)
 571 {
 572         struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
 573
 574         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 575 }
 576 EXPORT_SYMBOL(smp_ctl_clear_bit);
 577
 578 #ifdef CONFIG_CRASH_DUMP
 579
 580 int smp_store_status(int cpu)
 581 {
 582         struct pcpu *pcpu = pcpu_devices + cpu;
 583         unsigned long pa;
 584
 585         pa = __pa(&pcpu->lowcore->floating_pt_save_area);
 586         if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS,
 587                               pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
 588                 return -EIO;
 589         if (!MACHINE_HAS_VX && !MACHINE_HAS_GS)
 590                 return 0;
 591         pa = __pa(pcpu->lowcore->mcesad & MCESA_ORIGIN_MASK);
 592         if (MACHINE_HAS_GS)
 593                 pa |= pcpu->lowcore->mcesad & MCESA_LC_MASK;
 594         if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
 595                               pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
 596                 return -EIO;
 597         return 0;
 598 }
 599
 600 /*
 601  * Collect CPU state of the previous, crashed system.
 602  * There are four cases:
 603  * 1) standard zfcp dump
 604  *    condition: OLDMEM_BASE == NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
 605  *    The state for all CPUs except the boot CPU needs to be collected
 606  *    with sigp stop-and-store-status. The boot CPU state is located in
 607  *    the absolute lowcore of the memory stored in the HSA. The zcore code
 608  *    will copy the boot CPU state from the HSA.
 609  * 2) stand-alone kdump for SCSI (zfcp dump with swapped memory)
 610  *    condition: OLDMEM_BASE != NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
 611  *    The state for all CPUs except the boot CPU needs to be collected
 612  *    with sigp stop-and-store-status. The firmware or the boot-loader
 613  *    stored the registers of the boot CPU in the absolute lowcore in the
 614  *    memory of the old system.
 615  * 3) kdump and the old kernel did not store the CPU state,
 616  *    or stand-alone kdump for DASD
 617  *    condition: OLDMEM_BASE != NULL && !is_kdump_kernel()
 618  *    The state for all CPUs except the boot CPU needs to be collected
 619  *    with sigp stop-and-store-status. The kexec code or the boot-loader
 620  *    stored the registers of the boot CPU in the memory of the old system.
 621  * 4) kdump and the old kernel stored the CPU state
 622  *    condition: OLDMEM_BASE != NULL && is_kdump_kernel()
 623  *    This case does not exist for s390 anymore, setup_arch explicitly
 624  *    deactivates the elfcorehdr= kernel parameter
 625  */
 626 static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr,
 627                                      bool is_boot_cpu, unsigned long page)
 628 {
 629         __vector128 *vxrs = (__vector128 *) page;
 630
 631         if (is_boot_cpu)
 632                 vxrs = boot_cpu_vector_save_area;
 633         else
 634                 __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page);
 635         save_area_add_vxrs(sa, vxrs);
 636 }
 637
 638 static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr,
 639                                      bool is_boot_cpu, unsigned long page)
 640 {
 641         void *regs = (void *) page;
 642
 643         if (is_boot_cpu)
 644                 copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512);
 645         else
 646                 __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page);
 647         save_area_add_regs(sa, regs);
 648 }
 649
 650 void __init smp_save_dump_cpus(void)
 651 {
 652         int addr, boot_cpu_addr, max_cpu_addr;
 653         struct save_area *sa;
 654         unsigned long page;
 655         bool is_boot_cpu;
 656
 657         if (!(OLDMEM_BASE || ipl_info.type == IPL_TYPE_FCP_DUMP))
 658                 /* No previous system present, normal boot. */
 659                 return;
 660         /* Allocate a page as dumping area for the store status sigps */
 661         page = memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE, 0, 1UL << 31);
 662         if (!page)
 663                 panic("ERROR: Failed to allocate %lx bytes below %lx\n",
 664                       PAGE_SIZE, 1UL << 31);
 665
 666         /* Set multi-threading state to the previous system. */
 667         pcpu_set_smt(sclp.mtid_prev);
 668         boot_cpu_addr = stap();
 669         max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;
 670         for (addr = 0; addr <= max_cpu_addr; addr++) {
 671                 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==
 672                     SIGP_CC_NOT_OPERATIONAL)
 673                         continue;
 674                 is_boot_cpu = (addr == boot_cpu_addr);
 675                 /* Allocate save area */
 676                 sa = save_area_alloc(is_boot_cpu);
 677                 if (!sa)
 678                         panic("could not allocate memory for save area\n");
 679                 if (MACHINE_HAS_VX)
 680                         /* Get the vector registers */
 681                         smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page);
 682                 /*
 683                  * For a zfcp dump OLDMEM_BASE == NULL and the registers
 684                  * of the boot CPU are stored in the HSA. To retrieve
 685                  * these registers an SCLP request is required which is
 686                  * done by drivers/s390/char/zcore.c:init_cpu_info()
 687                  */
 688                 if (!is_boot_cpu || OLDMEM_BASE)
 689                         /* Get the CPU registers */
 690                         smp_save_cpu_regs(sa, addr, is_boot_cpu, page);
 691         }
 692         memblock_free(page, PAGE_SIZE);
 693         diag_dma_ops.diag308_reset();
 694         pcpu_set_smt(0);
 695 }
 696 #endif /* CONFIG_CRASH_DUMP */
 697
 698 void smp_cpu_set_polarization(int cpu, int val)
 699 {
 700         pcpu_devices[cpu].polarization = val;
 701 }
 702
 703 int smp_cpu_get_polarization(int cpu)
 704 {
 705         return pcpu_devices[cpu].polarization;
 706 }
 707
 708 static void __ref smp_get_core_info(struct sclp_core_info *info, int early)
 709 {
 710         static int use_sigp_detection;
 711         int address;
 712
 713         if (use_sigp_detection || sclp_get_core_info(info, early)) {
 714                 use_sigp_detection = 1;
 715                 for (address = 0;
 716                      address < (SCLP_MAX_CORES << smp_cpu_mt_shift);
 717                      address += (1U << smp_cpu_mt_shift)) {
 718                         if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) ==
 719                             SIGP_CC_NOT_OPERATIONAL)
 720                                 continue;
 721                         info->core[info->configured].core_id =
 722                                 address >> smp_cpu_mt_shift;
 723                         info->configured++;
 724                 }
 725                 info->combined = info->configured;
 726         }
 727 }
 728
 729 static int smp_add_present_cpu(int cpu);
 730
 731 static int __smp_rescan_cpus(struct sclp_core_info *info, int sysfs_add)
 732 {
 733         struct pcpu *pcpu;
 734         cpumask_t avail;
 735         int cpu, nr, i, j;
 736         u16 address;
 737
 738         nr = 0;
 739         cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
 740         cpu = cpumask_first(&avail);
 741         for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) {
 742                 if (sclp.has_core_type && info->core[i].type != boot_core_type)
 743                         continue;
 744                 address = info->core[i].core_id << smp_cpu_mt_shift;
 745                 for (j = 0; j <= smp_cpu_mtid; j++) {
 746                         if (pcpu_find_address(cpu_present_mask, address + j))
 747                                 continue;
 748                         pcpu = pcpu_devices + cpu;
 749                         pcpu->address = address + j;
 750                         pcpu->state =
 751                                 (cpu >= info->configured*(smp_cpu_mtid + 1)) ?
 752                                 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED;
 753                         smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
 754                         set_cpu_present(cpu, true);
 755                         if (sysfs_add && smp_add_present_cpu(cpu) != 0)
 756                                 set_cpu_present(cpu, false);
 757                         else
 758                                 nr++;
 759                         cpu = cpumask_next(cpu, &avail);
 760                         if (cpu >= nr_cpu_ids)
 761                                 break;
 762                 }
 763         }
 764         return nr;
 765 }
 766
 767 void __init smp_detect_cpus(void)
 768 {
 769         unsigned int cpu, mtid, c_cpus, s_cpus;
 770         struct sclp_core_info *info;
 771         u16 address;
 772
 773         /* Get CPU information */
 774         info = memblock_alloc(sizeof(*info), 8);
 775         if (!info)
 776                 panic("%s: Failed to allocate %zu bytes align=0x%x\n",
 777                       __func__, sizeof(*info), 8);
 778         smp_get_core_info(info, 1);
 779         /* Find boot CPU type */
 780         if (sclp.has_core_type) {
 781                 address = stap();
 782                 for (cpu = 0; cpu < info->combined; cpu++)
 783                         if (info->core[cpu].core_id == address) {
 784                                 /* The boot cpu dictates the cpu type. */
 785                                 boot_core_type = info->core[cpu].type;
 786                                 break;
 787                         }
 788                 if (cpu >= info->combined)
 789                         panic("Could not find boot CPU type");
 790         }
 791
 792         /* Set multi-threading state for the current system */
 793         mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp;
 794         mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1;
 795         pcpu_set_smt(mtid);
 796
 797         /* Print number of CPUs */
 798         c_cpus = s_cpus = 0;
 799         for (cpu = 0; cpu < info->combined; cpu++) {
 800                 if (sclp.has_core_type &&
 801                     info->core[cpu].type != boot_core_type)
 802                         continue;
 803                 if (cpu < info->configured)
 804                         c_cpus += smp_cpu_mtid + 1;
 805                 else
 806                         s_cpus += smp_cpu_mtid + 1;
 807         }
 808         pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
 809
 810         /* Add CPUs present at boot */
 811         get_online_cpus();
 812         __smp_rescan_cpus(info, 0);
 813         put_online_cpus();
 814         memblock_free_early((unsigned long)info, sizeof(*info));
 815 }
 816
 817 static void smp_init_secondary(void)
 818 {
 819         int cpu = smp_processor_id();
 820
 821         S390_lowcore.last_update_clock = get_tod_clock();
 822         restore_access_regs(S390_lowcore.access_regs_save_area);
 823         cpu_init();
 824         preempt_disable();
 825         init_cpu_timer();
 826         vtime_init();
 827         pfault_init();
 828         notify_cpu_starting(smp_processor_id());
 829         if (topology_cpu_dedicated(cpu))
 830                 set_cpu_flag(CIF_DEDICATED_CPU);
 831         else
 832                 clear_cpu_flag(CIF_DEDICATED_CPU);
 833         set_cpu_online(smp_processor_id(), true);
 834         inc_irq_stat(CPU_RST);
 835         local_irq_enable();
 836         cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 837 }
 838
 839 /*
 840  *      Activate a secondary processor.
 841  */
 842 static void __no_sanitize_address smp_start_secondary(void *cpuvoid)
 843 {
 844         S390_lowcore.restart_stack = (unsigned long) restart_stack;
 845         S390_lowcore.restart_fn = (unsigned long) do_restart;
 846         S390_lowcore.restart_data = 0;
 847         S390_lowcore.restart_source = -1UL;
 848         __ctl_load(S390_lowcore.cregs_save_area, 0, 15);
 849         __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
 850         CALL_ON_STACK(smp_init_secondary, S390_lowcore.kernel_stack, 0);
 851 }
 852
 853 /* Upping and downing of CPUs */
 854 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
 855 {
 856         struct pcpu *pcpu;
 857         int base, i, rc;
 858
 859         pcpu = pcpu_devices + cpu;
 860         if (pcpu->state != CPU_STATE_CONFIGURED)
 861                 return -EIO;
 862         base = smp_get_base_cpu(cpu);
 863         for (i = 0; i <= smp_cpu_mtid; i++) {
 864                 if (base + i < nr_cpu_ids)
 865                         if (cpu_online(base + i))
 866                                 break;
 867         }
 868         /*
 869          * If this is the first CPU of the core to get online
 870          * do an initial CPU reset.
 871          */
 872         if (i > smp_cpu_mtid &&
 873             pcpu_sigp_retry(pcpu_devices + base, SIGP_INITIAL_CPU_RESET, 0) !=
 874             SIGP_CC_ORDER_CODE_ACCEPTED)
 875                 return -EIO;
 876
 877         rc = pcpu_alloc_lowcore(pcpu, cpu);
 878         if (rc)
 879                 return rc;
 880         pcpu_prepare_secondary(pcpu, cpu);
 881         pcpu_attach_task(pcpu, tidle);
 882         pcpu_start_fn(pcpu, smp_start_secondary, NULL);
 883         /* Wait until cpu puts itself in the online & active maps */
 884         while (!cpu_online(cpu))
 885                 cpu_relax();
 886         return 0;
 887 }
 888
 889 static unsigned int setup_possible_cpus __initdata;
 890
 891 static int __init _setup_possible_cpus(char *s)
 892 {
 893         get_option(&s, &setup_possible_cpus);
 894         return 0;
 895 }
 896 early_param("possible_cpus", _setup_possible_cpus);
 897
 898 #ifdef CONFIG_HOTPLUG_CPU
 899
 900 int __cpu_disable(void)
 901 {
 902         unsigned long cregs[16];
 903
 904         /* Handle possible pending IPIs */
 905         smp_handle_ext_call();
 906         set_cpu_online(smp_processor_id(), false);
 907         /* Disable pseudo page faults on this cpu. */
 908         pfault_fini();
 909         /* Disable interrupt sources via control register. */
 910         __ctl_store(cregs, 0, 15);
 911         cregs[0]  &= ~0x0000ee70UL;     /* disable all external interrupts */
 912         cregs[6]  &= ~0xff000000UL;     /* disable all I/O interrupts */
 913         cregs[14] &= ~0x1f000000UL;     /* disable most machine checks */
 914         __ctl_load(cregs, 0, 15);
 915         clear_cpu_flag(CIF_NOHZ_DELAY);
 916         return 0;
 917 }
 918
 919 void __cpu_die(unsigned int cpu)
 920 {
 921         struct pcpu *pcpu;
 922
 923         /* Wait until target cpu is down */
 924         pcpu = pcpu_devices + cpu;
 925         while (!pcpu_stopped(pcpu))
 926                 cpu_relax();
 927         pcpu_free_lowcore(pcpu);
 928         cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
 929         cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
 930 }
 931
 932 void __noreturn cpu_die(void)
 933 {
 934         idle_task_exit();
 935         __bpon();
 936         pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
 937         for (;;) ;
 938 }
 939
 940 #endif /* CONFIG_HOTPLUG_CPU */
 941
 942 void __init smp_fill_possible_mask(void)
 943 {
 944         unsigned int possible, sclp_max, cpu;
 945
 946         sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1;
 947         sclp_max = min(smp_max_threads, sclp_max);
 948         sclp_max = (sclp.max_cores * sclp_max) ?: nr_cpu_ids;
 949         possible = setup_possible_cpus ?: nr_cpu_ids;
 950         possible = min(possible, sclp_max);
 951         for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
 952                 set_cpu_possible(cpu, true);
 953 }
 954
 955 void __init smp_prepare_cpus(unsigned int max_cpus)
 956 {
 957         /* request the 0x1201 emergency signal external interrupt */
 958         if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
 959                 panic("Couldn't request external interrupt 0x1201");
 960         /* request the 0x1202 external call external interrupt */
 961         if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
 962                 panic("Couldn't request external interrupt 0x1202");
 963 }
 964
 965 void __init smp_prepare_boot_cpu(void)
 966 {
 967         struct pcpu *pcpu = pcpu_devices;
 968
 969         WARN_ON(!cpu_present(0) || !cpu_online(0));
 970         pcpu->state = CPU_STATE_CONFIGURED;
 971         pcpu->lowcore = (struct lowcore *)(unsigned long) store_prefix();
 972         S390_lowcore.percpu_offset = __per_cpu_offset[0];
 973         smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
 974 }
 975
 976 void __init smp_cpus_done(unsigned int max_cpus)
 977 {
 978 }
 979
 980 void __init smp_setup_processor_id(void)
 981 {
 982         pcpu_devices[0].address = stap();
 983         S390_lowcore.cpu_nr = 0;
 984         S390_lowcore.spinlock_lockval = arch_spin_lockval(0);
 985         S390_lowcore.spinlock_index = 0;
 986 }
 987
 988 /*
 989  * the frequency of the profiling timer can be changed
 990  * by writing a multiplier value into /proc/profile.
 991  *
 992  * usually you want to run this on all CPUs ;)
 993  */
 994 int setup_profiling_timer(unsigned int multiplier)
 995 {
 996         return 0;
 997 }
 998
 999 #ifdef CONFIG_HOTPLUG_CPU
1000 static ssize_t cpu_configure_show(struct device *dev,
1001                                   struct device_attribute *attr, char *buf)
1002 {
1003         ssize_t count;
1004
1005         mutex_lock(&smp_cpu_state_mutex);
1006         count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
1007         mutex_unlock(&smp_cpu_state_mutex);
1008         return count;
1009 }
1010
1011 static ssize_t cpu_configure_store(struct device *dev,
1012                                    struct device_attribute *attr,
1013                                    const char *buf, size_t count)
1014 {
1015         struct pcpu *pcpu;
1016         int cpu, val, rc, i;
1017         char delim;
1018
1019         if (sscanf(buf, "%d %c", &val, &delim) != 1)
1020                 return -EINVAL;
1021         if (val != 0 && val != 1)
1022                 return -EINVAL;
1023         get_online_cpus();
1024         mutex_lock(&smp_cpu_state_mutex);
1025         rc = -EBUSY;
1026         /* disallow configuration changes of online cpus and cpu 0 */
1027         cpu = dev->id;
1028         cpu = smp_get_base_cpu(cpu);
1029         if (cpu == 0)
1030                 goto out;
1031         for (i = 0; i <= smp_cpu_mtid; i++)
1032                 if (cpu_online(cpu + i))
1033                         goto out;
1034         pcpu = pcpu_devices + cpu;
1035         rc = 0;
1036         switch (val) {
1037         case 0:
1038                 if (pcpu->state != CPU_STATE_CONFIGURED)
1039                         break;
1040                 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift);
1041                 if (rc)
1042                         break;
1043                 for (i = 0; i <= smp_cpu_mtid; i++) {
1044                         if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1045                                 continue;
1046                         pcpu[i].state = CPU_STATE_STANDBY;
1047                         smp_cpu_set_polarization(cpu + i,
1048                                                  POLARIZATION_UNKNOWN);
1049                 }
1050                 topology_expect_change();
1051                 break;
1052         case 1:
1053                 if (pcpu->state != CPU_STATE_STANDBY)
1054                         break;
1055                 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift);
1056                 if (rc)
1057                         break;
1058                 for (i = 0; i <= smp_cpu_mtid; i++) {
1059                         if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1060                                 continue;
1061                         pcpu[i].state = CPU_STATE_CONFIGURED;
1062                         smp_cpu_set_polarization(cpu + i,
1063                                                  POLARIZATION_UNKNOWN);
1064                 }
1065                 topology_expect_change();
1066                 break;
1067         default:
1068                 break;
1069         }
1070 out:
1071         mutex_unlock(&smp_cpu_state_mutex);
1072         put_online_cpus();
1073         return rc ? rc : count;
1074 }
1075 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
1076 #endif /* CONFIG_HOTPLUG_CPU */
1077
1078 static ssize_t show_cpu_address(struct device *dev,
1079                                 struct device_attribute *attr, char *buf)
1080 {
1081         return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
1082 }
1083 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
1084
1085 static struct attribute *cpu_common_attrs[] = {
1086 #ifdef CONFIG_HOTPLUG_CPU
1087         &dev_attr_configure.attr,
1088 #endif
1089         &dev_attr_address.attr,
1090         NULL,
1091 };
1092
1093 static struct attribute_group cpu_common_attr_group = {
1094         .attrs = cpu_common_attrs,
1095 };
1096
1097 static struct attribute *cpu_online_attrs[] = {
1098         &dev_attr_idle_count.attr,
1099         &dev_attr_idle_time_us.attr,
1100         NULL,
1101 };
1102
1103 static struct attribute_group cpu_online_attr_group = {
1104         .attrs = cpu_online_attrs,
1105 };
1106
1107 static int smp_cpu_online(unsigned int cpu)
1108 {
1109         struct device *s = &per_cpu(cpu_device, cpu)->dev;
1110
1111         return sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1112 }
1113 static int smp_cpu_pre_down(unsigned int cpu)
1114 {
1115         struct device *s = &per_cpu(cpu_device, cpu)->dev;
1116
1117         sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1118         return 0;
1119 }
1120
1121 static int smp_add_present_cpu(int cpu)
1122 {
1123         struct device *s;
1124         struct cpu *c;
1125         int rc;
1126
1127         c = kzalloc(sizeof(*c), GFP_KERNEL);
1128         if (!c)
1129                 return -ENOMEM;
1130         per_cpu(cpu_device, cpu) = c;
1131         s = &c->dev;
1132         c->hotpluggable = 1;
1133         rc = register_cpu(c, cpu);
1134         if (rc)
1135                 goto out;
1136         rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1137         if (rc)
1138                 goto out_cpu;
1139         rc = topology_cpu_init(c);
1140         if (rc)
1141                 goto out_topology;
1142         return 0;
1143
1144 out_topology:
1145         sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1146 out_cpu:
1147 #ifdef CONFIG_HOTPLUG_CPU
1148         unregister_cpu(c);
1149 #endif
1150 out:
1151         return rc;
1152 }
1153
1154 #ifdef CONFIG_HOTPLUG_CPU
1155
1156 int __ref smp_rescan_cpus(void)
1157 {
1158         struct sclp_core_info *info;
1159         int nr;
1160
1161         info = kzalloc(sizeof(*info), GFP_KERNEL);
1162         if (!info)
1163                 return -ENOMEM;
1164         smp_get_core_info(info, 0);
1165         get_online_cpus();
1166         mutex_lock(&smp_cpu_state_mutex);
1167         nr = __smp_rescan_cpus(info, 1);
1168         mutex_unlock(&smp_cpu_state_mutex);
1169         put_online_cpus();
1170         kfree(info);
1171         if (nr)
1172                 topology_schedule_update();
1173         return 0;
1174 }
1175
1176 static ssize_t __ref rescan_store(struct device *dev,
1177                                   struct device_attribute *attr,
1178                                   const char *buf,
1179                                   size_t count)
1180 {
1181         int rc;
1182
1183         rc = lock_device_hotplug_sysfs();
1184         if (rc)
1185                 return rc;
1186         rc = smp_rescan_cpus();
1187         unlock_device_hotplug();
1188         return rc ? rc : count;
1189 }
1190 static DEVICE_ATTR_WO(rescan);
1191 #endif /* CONFIG_HOTPLUG_CPU */
1192
1193 static int __init s390_smp_init(void)
1194 {
1195         int cpu, rc = 0;
1196
1197 #ifdef CONFIG_HOTPLUG_CPU
1198         rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1199         if (rc)
1200                 return rc;
1201 #endif
1202         for_each_present_cpu(cpu) {
1203                 rc = smp_add_present_cpu(cpu);
1204                 if (rc)
1205                         goto out;
1206         }
1207
1208         rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "s390/smp:online",
1209                                smp_cpu_online, smp_cpu_pre_down);
1210         rc = rc <= 0 ? rc : 0;
1211 out:
1212         return rc;
1213 }
1214 subsys_initcall(s390_smp_init);