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/irq_work.h>
  34 #include <linux/cpu.h>
  35 #include <linux/slab.h>
  36 #include <linux/sched/hotplug.h>
  37 #include <linux/sched/task_stack.h>
  38 #include <linux/crash_dump.h>
  39 #include <linux/kprobes.h>
  40 #include <asm/asm-offsets.h>
  41 #include <asm/diag.h>
  42 #include <asm/switch_to.h>
  43 #include <asm/facility.h>
  44 #include <asm/ipl.h>
  45 #include <asm/setup.h>
  46 #include <asm/irq.h>
  47 #include <asm/tlbflush.h>
  48 #include <asm/vtimer.h>
  49 #include <asm/lowcore.h>
  50 #include <asm/sclp.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 <asm/vdso.h>
  59 #include "entry.h"
  60
  61 enum {
  62         ec_schedule = 0,
  63         ec_call_function_single,
  64         ec_stop_cpu,
  65         ec_mcck_pending,
  66         ec_irq_work,
  67 };
  68
  69 enum {
  70         CPU_STATE_STANDBY,
  71         CPU_STATE_CONFIGURED,
  72 };
  73
  74 static DEFINE_PER_CPU(struct cpu *, cpu_device);
  75
  76 struct pcpu {
  77         unsigned long ec_mask;          /* bit mask for ec_xxx functions */
  78         unsigned long ec_clk;           /* sigp timestamp for ec_xxx */
  79         signed char state;              /* physical cpu state */
  80         signed char polarization;       /* physical polarization */
  81         u16 address;                    /* physical cpu address */
  82 };
  83
  84 static u8 boot_core_type;
  85 static struct pcpu pcpu_devices[NR_CPUS];
  86
  87 unsigned int smp_cpu_mt_shift;
  88 EXPORT_SYMBOL(smp_cpu_mt_shift);
  89
  90 unsigned int smp_cpu_mtid;
  91 EXPORT_SYMBOL(smp_cpu_mtid);
  92
  93 #ifdef CONFIG_CRASH_DUMP
  94 __vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
  95 #endif
  96
  97 static unsigned int smp_max_threads __initdata = -1U;
  98
  99 static int __init early_nosmt(char *s)
 100 {
 101         smp_max_threads = 1;
 102         return 0;
 103 }
 104 early_param("nosmt", early_nosmt);
 105
 106 static int __init early_smt(char *s)
 107 {
 108         get_option(&s, &smp_max_threads);
 109         return 0;
 110 }
 111 early_param("smt", early_smt);
 112
 113 /*
 114  * The smp_cpu_state_mutex must be held when changing the state or polarization
 115  * member of a pcpu data structure within the pcpu_devices arreay.
 116  */
 117 DEFINE_MUTEX(smp_cpu_state_mutex);
 118
 119 /*
 120  * Signal processor helper functions.
 121  */
 122 static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm)
 123 {
 124         int cc;
 125
 126         while (1) {
 127                 cc = __pcpu_sigp(addr, order, parm, NULL);
 128                 if (cc != SIGP_CC_BUSY)
 129                         return cc;
 130                 cpu_relax();
 131         }
 132 }
 133
 134 static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
 135 {
 136         int cc, retry;
 137
 138         for (retry = 0; ; retry++) {
 139                 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
 140                 if (cc != SIGP_CC_BUSY)
 141                         break;
 142                 if (retry >= 3)
 143                         udelay(10);
 144         }
 145         return cc;
 146 }
 147
 148 static inline int pcpu_stopped(struct pcpu *pcpu)
 149 {
 150         u32 status;
 151
 152         if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
 153                         0, &status) != SIGP_CC_STATUS_STORED)
 154                 return 0;
 155         return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
 156 }
 157
 158 static inline int pcpu_running(struct pcpu *pcpu)
 159 {
 160         if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
 161                         0, NULL) != SIGP_CC_STATUS_STORED)
 162                 return 1;
 163         /* Status stored condition code is equivalent to cpu not running. */
 164         return 0;
 165 }
 166
 167 /*
 168  * Find struct pcpu by cpu address.
 169  */
 170 static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address)
 171 {
 172         int cpu;
 173
 174         for_each_cpu(cpu, mask)
 175                 if (pcpu_devices[cpu].address == address)
 176                         return pcpu_devices + cpu;
 177         return NULL;
 178 }
 179
 180 static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
 181 {
 182         int order;
 183
 184         if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
 185                 return;
 186         order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
 187         pcpu->ec_clk = get_tod_clock_fast();
 188         pcpu_sigp_retry(pcpu, order, 0);
 189 }
 190
 191 static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
 192 {
 193         unsigned long async_stack, nodat_stack, mcck_stack;
 194         struct lowcore *lc;
 195
 196         lc = (struct lowcore *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
 197         nodat_stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
 198         async_stack = stack_alloc();
 199         mcck_stack = stack_alloc();
 200         if (!lc || !nodat_stack || !async_stack || !mcck_stack)
 201                 goto out;
 202         memcpy(lc, &S390_lowcore, 512);
 203         memset((char *) lc + 512, 0, sizeof(*lc) - 512);
 204         lc->async_stack = async_stack + STACK_INIT_OFFSET;
 205         lc->nodat_stack = nodat_stack + STACK_INIT_OFFSET;
 206         lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;
 207         lc->cpu_nr = cpu;
 208         lc->spinlock_lockval = arch_spin_lockval(cpu);
 209         lc->spinlock_index = 0;
 210         lc->br_r1_trampoline = 0x07f1;  /* br %r1 */
 211         lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
 212         lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
 213         lc->preempt_count = PREEMPT_DISABLED;
 214         if (nmi_alloc_per_cpu(lc))
 215                 goto out;
 216         lowcore_ptr[cpu] = lc;
 217         pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
 218         return 0;
 219
 220 out:
 221         stack_free(mcck_stack);
 222         stack_free(async_stack);
 223         free_pages(nodat_stack, THREAD_SIZE_ORDER);
 224         free_pages((unsigned long) lc, LC_ORDER);
 225         return -ENOMEM;
 226 }
 227
 228 static void pcpu_free_lowcore(struct pcpu *pcpu)
 229 {
 230         unsigned long async_stack, nodat_stack, mcck_stack;
 231         struct lowcore *lc;
 232         int cpu;
 233
 234         cpu = pcpu - pcpu_devices;
 235         lc = lowcore_ptr[cpu];
 236         nodat_stack = lc->nodat_stack - STACK_INIT_OFFSET;
 237         async_stack = lc->async_stack - STACK_INIT_OFFSET;
 238         mcck_stack = lc->mcck_stack - STACK_INIT_OFFSET;
 239         pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
 240         lowcore_ptr[cpu] = NULL;
 241         nmi_free_per_cpu(lc);
 242         stack_free(async_stack);
 243         stack_free(mcck_stack);
 244         free_pages(nodat_stack, THREAD_SIZE_ORDER);
 245         free_pages((unsigned long) lc, LC_ORDER);
 246 }
 247
 248 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
 249 {
 250         struct lowcore *lc = lowcore_ptr[cpu];
 251
 252         cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
 253         cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
 254         lc->cpu_nr = cpu;
 255         lc->spinlock_lockval = arch_spin_lockval(cpu);
 256         lc->spinlock_index = 0;
 257         lc->percpu_offset = __per_cpu_offset[cpu];
 258         lc->kernel_asce = S390_lowcore.kernel_asce;
 259         lc->user_asce = s390_invalid_asce;
 260         lc->machine_flags = S390_lowcore.machine_flags;
 261         lc->user_timer = lc->system_timer =
 262                 lc->steal_timer = lc->avg_steal_timer = 0;
 263         __ctl_store(lc->cregs_save_area, 0, 15);
 264         lc->cregs_save_area[1] = lc->kernel_asce;
 265         lc->cregs_save_area[7] = lc->user_asce;
 266         save_access_regs((unsigned int *) lc->access_regs_save_area);
 267         arch_spin_lock_setup(cpu);
 268 }
 269
 270 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
 271 {
 272         struct lowcore *lc;
 273         int cpu;
 274
 275         cpu = pcpu - pcpu_devices;
 276         lc = lowcore_ptr[cpu];
 277         lc->kernel_stack = (unsigned long) task_stack_page(tsk)
 278                 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
 279         lc->current_task = (unsigned long) tsk;
 280         lc->lpp = LPP_MAGIC;
 281         lc->current_pid = tsk->pid;
 282         lc->user_timer = tsk->thread.user_timer;
 283         lc->guest_timer = tsk->thread.guest_timer;
 284         lc->system_timer = tsk->thread.system_timer;
 285         lc->hardirq_timer = tsk->thread.hardirq_timer;
 286         lc->softirq_timer = tsk->thread.softirq_timer;
 287         lc->steal_timer = 0;
 288 }
 289
 290 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
 291 {
 292         struct lowcore *lc;
 293         int cpu;
 294
 295         cpu = pcpu - pcpu_devices;
 296         lc = lowcore_ptr[cpu];
 297         lc->restart_stack = lc->nodat_stack;
 298         lc->restart_fn = (unsigned long) func;
 299         lc->restart_data = (unsigned long) data;
 300         lc->restart_source = -1UL;
 301         pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
 302 }
 303
 304 typedef void (pcpu_delegate_fn)(void *);
 305
 306 /*
 307  * Call function via PSW restart on pcpu and stop the current cpu.
 308  */
 309 static void __pcpu_delegate(pcpu_delegate_fn *func, void *data)
 310 {
 311         func(data);     /* should not return */
 312 }
 313
 314 static void __no_sanitize_address pcpu_delegate(struct pcpu *pcpu,
 315                                                 pcpu_delegate_fn *func,
 316                                                 void *data, unsigned long stack)
 317 {
 318         struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
 319         unsigned long source_cpu = stap();
 320
 321         __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
 322         if (pcpu->address == source_cpu) {
 323                 call_on_stack(2, stack, void, __pcpu_delegate,
 324                               pcpu_delegate_fn *, func, void *, data);
 325         }
 326         /* Stop target cpu (if func returns this stops the current cpu). */
 327         pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
 328         /* Restart func on the target cpu and stop the current cpu. */
 329         mem_assign_absolute(lc->restart_stack, stack);
 330         mem_assign_absolute(lc->restart_fn, (unsigned long) func);
 331         mem_assign_absolute(lc->restart_data, (unsigned long) data);
 332         mem_assign_absolute(lc->restart_source, source_cpu);
 333         __bpon();
 334         asm volatile(
 335                 "0:     sigp    0,%0,%2 # sigp restart to target cpu\n"
 336                 "       brc     2,0b    # busy, try again\n"
 337                 "1:     sigp    0,%1,%3 # sigp stop to current cpu\n"
 338                 "       brc     2,1b    # busy, try again\n"
 339                 : : "d" (pcpu->address), "d" (source_cpu),
 340                     "K" (SIGP_RESTART), "K" (SIGP_STOP)
 341                 : "0", "1", "cc");
 342         for (;;) ;
 343 }
 344
 345 /*
 346  * Enable additional logical cpus for multi-threading.
 347  */
 348 static int pcpu_set_smt(unsigned int mtid)
 349 {
 350         int cc;
 351
 352         if (smp_cpu_mtid == mtid)
 353                 return 0;
 354         cc = __pcpu_sigp(0, SIGP_SET_MULTI_THREADING, mtid, NULL);
 355         if (cc == 0) {
 356                 smp_cpu_mtid = mtid;
 357                 smp_cpu_mt_shift = 0;
 358                 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift))
 359                         smp_cpu_mt_shift++;
 360                 pcpu_devices[0].address = stap();
 361         }
 362         return cc;
 363 }
 364
 365 /*
 366  * Call function on an online CPU.
 367  */
 368 void smp_call_online_cpu(void (*func)(void *), void *data)
 369 {
 370         struct pcpu *pcpu;
 371
 372         /* Use the current cpu if it is online. */
 373         pcpu = pcpu_find_address(cpu_online_mask, stap());
 374         if (!pcpu)
 375                 /* Use the first online cpu. */
 376                 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
 377         pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
 378 }
 379
 380 /*
 381  * Call function on the ipl CPU.
 382  */
 383 void smp_call_ipl_cpu(void (*func)(void *), void *data)
 384 {
 385         struct lowcore *lc = lowcore_ptr[0];
 386
 387         if (pcpu_devices[0].address == stap())
 388                 lc = &S390_lowcore;
 389
 390         pcpu_delegate(&pcpu_devices[0], func, data,
 391                       lc->nodat_stack);
 392 }
 393
 394 int smp_find_processor_id(u16 address)
 395 {
 396         int cpu;
 397
 398         for_each_present_cpu(cpu)
 399                 if (pcpu_devices[cpu].address == address)
 400                         return cpu;
 401         return -1;
 402 }
 403
 404 void schedule_mcck_handler(void)
 405 {
 406         pcpu_ec_call(pcpu_devices + smp_processor_id(), ec_mcck_pending);
 407 }
 408
 409 bool notrace arch_vcpu_is_preempted(int cpu)
 410 {
 411         if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu))
 412                 return false;
 413         if (pcpu_running(pcpu_devices + cpu))
 414                 return false;
 415         return true;
 416 }
 417 EXPORT_SYMBOL(arch_vcpu_is_preempted);
 418
 419 void notrace smp_yield_cpu(int cpu)
 420 {
 421         if (!MACHINE_HAS_DIAG9C)
 422                 return;
 423         diag_stat_inc_norecursion(DIAG_STAT_X09C);
 424         asm volatile("diag %0,0,0x9c"
 425                      : : "d" (pcpu_devices[cpu].address));
 426 }
 427 EXPORT_SYMBOL_GPL(smp_yield_cpu);
 428
 429 /*
 430  * Send cpus emergency shutdown signal. This gives the cpus the
 431  * opportunity to complete outstanding interrupts.
 432  */
 433 void notrace smp_emergency_stop(void)
 434 {
 435         static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED;
 436         static cpumask_t cpumask;
 437         u64 end;
 438         int cpu;
 439
 440         arch_spin_lock(&lock);
 441         cpumask_copy(&cpumask, cpu_online_mask);
 442         cpumask_clear_cpu(smp_processor_id(), &cpumask);
 443
 444         end = get_tod_clock() + (1000000UL << 12);
 445         for_each_cpu(cpu, &cpumask) {
 446                 struct pcpu *pcpu = pcpu_devices + cpu;
 447                 set_bit(ec_stop_cpu, &pcpu->ec_mask);
 448                 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
 449                                    0, NULL) == SIGP_CC_BUSY &&
 450                        get_tod_clock() < end)
 451                         cpu_relax();
 452         }
 453         while (get_tod_clock() < end) {
 454                 for_each_cpu(cpu, &cpumask)
 455                         if (pcpu_stopped(pcpu_devices + cpu))
 456                                 cpumask_clear_cpu(cpu, &cpumask);
 457                 if (cpumask_empty(&cpumask))
 458                         break;
 459                 cpu_relax();
 460         }
 461         arch_spin_unlock(&lock);
 462 }
 463 NOKPROBE_SYMBOL(smp_emergency_stop);
 464
 465 /*
 466  * Stop all cpus but the current one.
 467  */
 468 void smp_send_stop(void)
 469 {
 470         int cpu;
 471
 472         /* Disable all interrupts/machine checks */
 473         __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
 474         trace_hardirqs_off();
 475
 476         debug_set_critical();
 477
 478         if (oops_in_progress)
 479                 smp_emergency_stop();
 480
 481         /* stop all processors */
 482         for_each_online_cpu(cpu) {
 483                 if (cpu == smp_processor_id())
 484                         continue;
 485                 pcpu_sigp_retry(pcpu_devices + cpu, SIGP_STOP, 0);
 486                 while (!pcpu_stopped(pcpu_devices + cpu))
 487                         cpu_relax();
 488         }
 489 }
 490
 491 /*
 492  * This is the main routine where commands issued by other
 493  * cpus are handled.
 494  */
 495 static void smp_handle_ext_call(void)
 496 {
 497         unsigned long bits;
 498
 499         /* handle bit signal external calls */
 500         bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
 501         if (test_bit(ec_stop_cpu, &bits))
 502                 smp_stop_cpu();
 503         if (test_bit(ec_schedule, &bits))
 504                 scheduler_ipi();
 505         if (test_bit(ec_call_function_single, &bits))
 506                 generic_smp_call_function_single_interrupt();
 507         if (test_bit(ec_mcck_pending, &bits))
 508                 __s390_handle_mcck();
 509         if (test_bit(ec_irq_work, &bits))
 510                 irq_work_run();
 511 }
 512
 513 static void do_ext_call_interrupt(struct ext_code ext_code,
 514                                   unsigned int param32, unsigned long param64)
 515 {
 516         inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
 517         smp_handle_ext_call();
 518 }
 519
 520 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 521 {
 522         int cpu;
 523
 524         for_each_cpu(cpu, mask)
 525                 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
 526 }
 527
 528 void arch_send_call_function_single_ipi(int cpu)
 529 {
 530         pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
 531 }
 532
 533 /*
 534  * this function sends a 'reschedule' IPI to another CPU.
 535  * it goes straight through and wastes no time serializing
 536  * anything. Worst case is that we lose a reschedule ...
 537  */
 538 void smp_send_reschedule(int cpu)
 539 {
 540         pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
 541 }
 542
 543 #ifdef CONFIG_IRQ_WORK
 544 void arch_irq_work_raise(void)
 545 {
 546         pcpu_ec_call(pcpu_devices + smp_processor_id(), ec_irq_work);
 547 }
 548 #endif
 549
 550 /*
 551  * parameter area for the set/clear control bit callbacks
 552  */
 553 struct ec_creg_mask_parms {
 554         unsigned long orval;
 555         unsigned long andval;
 556         int cr;
 557 };
 558
 559 /*
 560  * callback for setting/clearing control bits
 561  */
 562 static void smp_ctl_bit_callback(void *info)
 563 {
 564         struct ec_creg_mask_parms *pp = info;
 565         unsigned long cregs[16];
 566
 567         __ctl_store(cregs, 0, 15);
 568         cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
 569         __ctl_load(cregs, 0, 15);
 570 }
 571
 572 /*
 573  * Set a bit in a control register of all cpus
 574  */
 575 void smp_ctl_set_bit(int cr, int bit)
 576 {
 577         struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
 578
 579         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 580 }
 581 EXPORT_SYMBOL(smp_ctl_set_bit);
 582
 583 /*
 584  * Clear a bit in a control register of all cpus
 585  */
 586 void smp_ctl_clear_bit(int cr, int bit)
 587 {
 588         struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
 589
 590         on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 591 }
 592 EXPORT_SYMBOL(smp_ctl_clear_bit);
 593
 594 #ifdef CONFIG_CRASH_DUMP
 595
 596 int smp_store_status(int cpu)
 597 {
 598         struct lowcore *lc;
 599         struct pcpu *pcpu;
 600         unsigned long pa;
 601
 602         pcpu = pcpu_devices + cpu;
 603         lc = lowcore_ptr[cpu];
 604         pa = __pa(&lc->floating_pt_save_area);
 605         if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS,
 606                               pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
 607                 return -EIO;
 608         if (!MACHINE_HAS_VX && !MACHINE_HAS_GS)
 609                 return 0;
 610         pa = __pa(lc->mcesad & MCESA_ORIGIN_MASK);
 611         if (MACHINE_HAS_GS)
 612                 pa |= lc->mcesad & MCESA_LC_MASK;
 613         if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
 614                               pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
 615                 return -EIO;
 616         return 0;
 617 }
 618
 619 /*
 620  * Collect CPU state of the previous, crashed system.
 621  * There are four cases:
 622  * 1) standard zfcp/nvme dump
 623  *    condition: OLDMEM_BASE == NULL && is_ipl_type_dump() == true
 624  *    The state for all CPUs except the boot CPU needs to be collected
 625  *    with sigp stop-and-store-status. The boot CPU state is located in
 626  *    the absolute lowcore of the memory stored in the HSA. The zcore code
 627  *    will copy the boot CPU state from the HSA.
 628  * 2) stand-alone kdump for SCSI/NVMe (zfcp/nvme dump with swapped memory)
 629  *    condition: OLDMEM_BASE != NULL && is_ipl_type_dump() == true
 630  *    The state for all CPUs except the boot CPU needs to be collected
 631  *    with sigp stop-and-store-status. The firmware or the boot-loader
 632  *    stored the registers of the boot CPU in the absolute lowcore in the
 633  *    memory of the old system.
 634  * 3) kdump and the old kernel did not store the CPU state,
 635  *    or stand-alone kdump for DASD
 636  *    condition: OLDMEM_BASE != NULL && !is_kdump_kernel()
 637  *    The state for all CPUs except the boot CPU needs to be collected
 638  *    with sigp stop-and-store-status. The kexec code or the boot-loader
 639  *    stored the registers of the boot CPU in the memory of the old system.
 640  * 4) kdump and the old kernel stored the CPU state
 641  *    condition: OLDMEM_BASE != NULL && is_kdump_kernel()
 642  *    This case does not exist for s390 anymore, setup_arch explicitly
 643  *    deactivates the elfcorehdr= kernel parameter
 644  */
 645 static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr,
 646                                      bool is_boot_cpu, unsigned long page)
 647 {
 648         __vector128 *vxrs = (__vector128 *) page;
 649
 650         if (is_boot_cpu)
 651                 vxrs = boot_cpu_vector_save_area;
 652         else
 653                 __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page);
 654         save_area_add_vxrs(sa, vxrs);
 655 }
 656
 657 static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr,
 658                                      bool is_boot_cpu, unsigned long page)
 659 {
 660         void *regs = (void *) page;
 661
 662         if (is_boot_cpu)
 663                 copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512);
 664         else
 665                 __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page);
 666         save_area_add_regs(sa, regs);
 667 }
 668
 669 void __init smp_save_dump_cpus(void)
 670 {
 671         int addr, boot_cpu_addr, max_cpu_addr;
 672         struct save_area *sa;
 673         unsigned long page;
 674         bool is_boot_cpu;
 675
 676         if (!(OLDMEM_BASE || is_ipl_type_dump()))
 677                 /* No previous system present, normal boot. */
 678                 return;
 679         /* Allocate a page as dumping area for the store status sigps */
 680         page = memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE, 0, 1UL << 31);
 681         if (!page)
 682                 panic("ERROR: Failed to allocate %lx bytes below %lx\n",
 683                       PAGE_SIZE, 1UL << 31);
 684
 685         /* Set multi-threading state to the previous system. */
 686         pcpu_set_smt(sclp.mtid_prev);
 687         boot_cpu_addr = stap();
 688         max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;
 689         for (addr = 0; addr <= max_cpu_addr; addr++) {
 690                 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==
 691                     SIGP_CC_NOT_OPERATIONAL)
 692                         continue;
 693                 is_boot_cpu = (addr == boot_cpu_addr);
 694                 /* Allocate save area */
 695                 sa = save_area_alloc(is_boot_cpu);
 696                 if (!sa)
 697                         panic("could not allocate memory for save area\n");
 698                 if (MACHINE_HAS_VX)
 699                         /* Get the vector registers */
 700                         smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page);
 701                 /*
 702                  * For a zfcp/nvme dump OLDMEM_BASE == NULL and the registers
 703                  * of the boot CPU are stored in the HSA. To retrieve
 704                  * these registers an SCLP request is required which is
 705                  * done by drivers/s390/char/zcore.c:init_cpu_info()
 706                  */
 707                 if (!is_boot_cpu || OLDMEM_BASE)
 708                         /* Get the CPU registers */
 709                         smp_save_cpu_regs(sa, addr, is_boot_cpu, page);
 710         }
 711         memblock_free(page, PAGE_SIZE);
 712         diag_dma_ops.diag308_reset();
 713         pcpu_set_smt(0);
 714 }
 715 #endif /* CONFIG_CRASH_DUMP */
 716
 717 void smp_cpu_set_polarization(int cpu, int val)
 718 {
 719         pcpu_devices[cpu].polarization = val;
 720 }
 721
 722 int smp_cpu_get_polarization(int cpu)
 723 {
 724         return pcpu_devices[cpu].polarization;
 725 }
 726
 727 int smp_cpu_get_cpu_address(int cpu)
 728 {
 729         return pcpu_devices[cpu].address;
 730 }
 731
 732 static void __ref smp_get_core_info(struct sclp_core_info *info, int early)
 733 {
 734         static int use_sigp_detection;
 735         int address;
 736
 737         if (use_sigp_detection || sclp_get_core_info(info, early)) {
 738                 use_sigp_detection = 1;
 739                 for (address = 0;
 740                      address < (SCLP_MAX_CORES << smp_cpu_mt_shift);
 741                      address += (1U << smp_cpu_mt_shift)) {
 742                         if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) ==
 743                             SIGP_CC_NOT_OPERATIONAL)
 744                                 continue;
 745                         info->core[info->configured].core_id =
 746                                 address >> smp_cpu_mt_shift;
 747                         info->configured++;
 748                 }
 749                 info->combined = info->configured;
 750         }
 751 }
 752
 753 static int smp_add_present_cpu(int cpu);
 754
 755 static int smp_add_core(struct sclp_core_entry *core, cpumask_t *avail,
 756                         bool configured, bool early)
 757 {
 758         struct pcpu *pcpu;
 759         int cpu, nr, i;
 760         u16 address;
 761
 762         nr = 0;
 763         if (sclp.has_core_type && core->type != boot_core_type)
 764                 return nr;
 765         cpu = cpumask_first(avail);
 766         address = core->core_id << smp_cpu_mt_shift;
 767         for (i = 0; (i <= smp_cpu_mtid) && (cpu < nr_cpu_ids); i++) {
 768                 if (pcpu_find_address(cpu_present_mask, address + i))
 769                         continue;
 770                 pcpu = pcpu_devices + cpu;
 771                 pcpu->address = address + i;
 772                 if (configured)
 773                         pcpu->state = CPU_STATE_CONFIGURED;
 774                 else
 775                         pcpu->state = CPU_STATE_STANDBY;
 776                 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
 777                 set_cpu_present(cpu, true);
 778                 if (!early && smp_add_present_cpu(cpu) != 0)
 779                         set_cpu_present(cpu, false);
 780                 else
 781                         nr++;
 782                 cpumask_clear_cpu(cpu, avail);
 783                 cpu = cpumask_next(cpu, avail);
 784         }
 785         return nr;
 786 }
 787
 788 static int __smp_rescan_cpus(struct sclp_core_info *info, bool early)
 789 {
 790         struct sclp_core_entry *core;
 791         static cpumask_t avail;
 792         bool configured;
 793         u16 core_id;
 794         int nr, i;
 795
 796         get_online_cpus();
 797         mutex_lock(&smp_cpu_state_mutex);
 798         nr = 0;
 799         cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
 800         /*
 801          * Add IPL core first (which got logical CPU number 0) to make sure
 802          * that all SMT threads get subsequent logical CPU numbers.
 803          */
 804         if (early) {
 805                 core_id = pcpu_devices[0].address >> smp_cpu_mt_shift;
 806                 for (i = 0; i < info->configured; i++) {
 807                         core = &info->core[i];
 808                         if (core->core_id == core_id) {
 809                                 nr += smp_add_core(core, &avail, true, early);
 810                                 break;
 811                         }
 812                 }
 813         }
 814         for (i = 0; i < info->combined; i++) {
 815                 configured = i < info->configured;
 816                 nr += smp_add_core(&info->core[i], &avail, configured, early);
 817         }
 818         mutex_unlock(&smp_cpu_state_mutex);
 819         put_online_cpus();
 820         return nr;
 821 }
 822
 823 void __init smp_detect_cpus(void)
 824 {
 825         unsigned int cpu, mtid, c_cpus, s_cpus;
 826         struct sclp_core_info *info;
 827         u16 address;
 828
 829         /* Get CPU information */
 830         info = memblock_alloc(sizeof(*info), 8);
 831         if (!info)
 832                 panic("%s: Failed to allocate %zu bytes align=0x%x\n",
 833                       __func__, sizeof(*info), 8);
 834         smp_get_core_info(info, 1);
 835         /* Find boot CPU type */
 836         if (sclp.has_core_type) {
 837                 address = stap();
 838                 for (cpu = 0; cpu < info->combined; cpu++)
 839                         if (info->core[cpu].core_id == address) {
 840                                 /* The boot cpu dictates the cpu type. */
 841                                 boot_core_type = info->core[cpu].type;
 842                                 break;
 843                         }
 844                 if (cpu >= info->combined)
 845                         panic("Could not find boot CPU type");
 846         }
 847
 848         /* Set multi-threading state for the current system */
 849         mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp;
 850         mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1;
 851         pcpu_set_smt(mtid);
 852
 853         /* Print number of CPUs */
 854         c_cpus = s_cpus = 0;
 855         for (cpu = 0; cpu < info->combined; cpu++) {
 856                 if (sclp.has_core_type &&
 857                     info->core[cpu].type != boot_core_type)
 858                         continue;
 859                 if (cpu < info->configured)
 860                         c_cpus += smp_cpu_mtid + 1;
 861                 else
 862                         s_cpus += smp_cpu_mtid + 1;
 863         }
 864         pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
 865
 866         /* Add CPUs present at boot */
 867         __smp_rescan_cpus(info, true);
 868         memblock_free_early((unsigned long)info, sizeof(*info));
 869 }
 870
 871 static void smp_init_secondary(void)
 872 {
 873         int cpu = raw_smp_processor_id();
 874
 875         S390_lowcore.last_update_clock = get_tod_clock();
 876         restore_access_regs(S390_lowcore.access_regs_save_area);
 877         cpu_init();
 878         rcu_cpu_starting(cpu);
 879         init_cpu_timer();
 880         vtime_init();
 881         vdso_getcpu_init();
 882         pfault_init();
 883         notify_cpu_starting(cpu);
 884         if (topology_cpu_dedicated(cpu))
 885                 set_cpu_flag(CIF_DEDICATED_CPU);
 886         else
 887                 clear_cpu_flag(CIF_DEDICATED_CPU);
 888         set_cpu_online(cpu, true);
 889         update_cpu_masks();
 890         inc_irq_stat(CPU_RST);
 891         local_irq_enable();
 892         cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 893 }
 894
 895 /*
 896  *      Activate a secondary processor.
 897  */
 898 static void __no_sanitize_address smp_start_secondary(void *cpuvoid)
 899 {
 900         S390_lowcore.restart_stack = (unsigned long) restart_stack;
 901         S390_lowcore.restart_fn = (unsigned long) do_restart;
 902         S390_lowcore.restart_data = 0;
 903         S390_lowcore.restart_source = -1UL;
 904         __ctl_load(S390_lowcore.cregs_save_area, 0, 15);
 905         __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
 906         call_on_stack_noreturn(smp_init_secondary, S390_lowcore.kernel_stack);
 907 }
 908
 909 /* Upping and downing of CPUs */
 910 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
 911 {
 912         struct pcpu *pcpu = pcpu_devices + cpu;
 913         int rc;
 914
 915         if (pcpu->state != CPU_STATE_CONFIGURED)
 916                 return -EIO;
 917         if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) !=
 918             SIGP_CC_ORDER_CODE_ACCEPTED)
 919                 return -EIO;
 920
 921         rc = pcpu_alloc_lowcore(pcpu, cpu);
 922         if (rc)
 923                 return rc;
 924         pcpu_prepare_secondary(pcpu, cpu);
 925         pcpu_attach_task(pcpu, tidle);
 926         pcpu_start_fn(pcpu, smp_start_secondary, NULL);
 927         /* Wait until cpu puts itself in the online & active maps */
 928         while (!cpu_online(cpu))
 929                 cpu_relax();
 930         return 0;
 931 }
 932
 933 static unsigned int setup_possible_cpus __initdata;
 934
 935 static int __init _setup_possible_cpus(char *s)
 936 {
 937         get_option(&s, &setup_possible_cpus);
 938         return 0;
 939 }
 940 early_param("possible_cpus", _setup_possible_cpus);
 941
 942 int __cpu_disable(void)
 943 {
 944         unsigned long cregs[16];
 945
 946         /* Handle possible pending IPIs */
 947         smp_handle_ext_call();
 948         set_cpu_online(smp_processor_id(), false);
 949         update_cpu_masks();
 950         /* Disable pseudo page faults on this cpu. */
 951         pfault_fini();
 952         /* Disable interrupt sources via control register. */
 953         __ctl_store(cregs, 0, 15);
 954         cregs[0]  &= ~0x0000ee70UL;     /* disable all external interrupts */
 955         cregs[6]  &= ~0xff000000UL;     /* disable all I/O interrupts */
 956         cregs[14] &= ~0x1f000000UL;     /* disable most machine checks */
 957         __ctl_load(cregs, 0, 15);
 958         clear_cpu_flag(CIF_NOHZ_DELAY);
 959         return 0;
 960 }
 961
 962 void __cpu_die(unsigned int cpu)
 963 {
 964         struct pcpu *pcpu;
 965
 966         /* Wait until target cpu is down */
 967         pcpu = pcpu_devices + cpu;
 968         while (!pcpu_stopped(pcpu))
 969                 cpu_relax();
 970         pcpu_free_lowcore(pcpu);
 971         cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
 972         cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
 973 }
 974
 975 void __noreturn cpu_die(void)
 976 {
 977         idle_task_exit();
 978         __bpon();
 979         pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
 980         for (;;) ;
 981 }
 982
 983 void __init smp_fill_possible_mask(void)
 984 {
 985         unsigned int possible, sclp_max, cpu;
 986
 987         sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1;
 988         sclp_max = min(smp_max_threads, sclp_max);
 989         sclp_max = (sclp.max_cores * sclp_max) ?: nr_cpu_ids;
 990         possible = setup_possible_cpus ?: nr_cpu_ids;
 991         possible = min(possible, sclp_max);
 992         for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
 993                 set_cpu_possible(cpu, true);
 994 }
 995
 996 void __init smp_prepare_cpus(unsigned int max_cpus)
 997 {
 998         /* request the 0x1201 emergency signal external interrupt */
 999         if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
1000                 panic("Couldn't request external interrupt 0x1201");
1001         /* request the 0x1202 external call external interrupt */
1002         if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
1003                 panic("Couldn't request external interrupt 0x1202");
1004 }
1005
1006 void __init smp_prepare_boot_cpu(void)
1007 {
1008         struct pcpu *pcpu = pcpu_devices;
1009
1010         WARN_ON(!cpu_present(0) || !cpu_online(0));
1011         pcpu->state = CPU_STATE_CONFIGURED;
1012         S390_lowcore.percpu_offset = __per_cpu_offset[0];
1013         smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
1014 }
1015
1016 void __init smp_setup_processor_id(void)
1017 {
1018         pcpu_devices[0].address = stap();
1019         S390_lowcore.cpu_nr = 0;
1020         S390_lowcore.spinlock_lockval = arch_spin_lockval(0);
1021         S390_lowcore.spinlock_index = 0;
1022 }
1023
1024 /*
1025  * the frequency of the profiling timer can be changed
1026  * by writing a multiplier value into /proc/profile.
1027  *
1028  * usually you want to run this on all CPUs ;)
1029  */
1030 int setup_profiling_timer(unsigned int multiplier)
1031 {
1032         return 0;
1033 }
1034
1035 static ssize_t cpu_configure_show(struct device *dev,
1036                                   struct device_attribute *attr, char *buf)
1037 {
1038         ssize_t count;
1039
1040         mutex_lock(&smp_cpu_state_mutex);
1041         count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
1042         mutex_unlock(&smp_cpu_state_mutex);
1043         return count;
1044 }
1045
1046 static ssize_t cpu_configure_store(struct device *dev,
1047                                    struct device_attribute *attr,
1048                                    const char *buf, size_t count)
1049 {
1050         struct pcpu *pcpu;
1051         int cpu, val, rc, i;
1052         char delim;
1053
1054         if (sscanf(buf, "%d %c", &val, &delim) != 1)
1055                 return -EINVAL;
1056         if (val != 0 && val != 1)
1057                 return -EINVAL;
1058         get_online_cpus();
1059         mutex_lock(&smp_cpu_state_mutex);
1060         rc = -EBUSY;
1061         /* disallow configuration changes of online cpus and cpu 0 */
1062         cpu = dev->id;
1063         cpu = smp_get_base_cpu(cpu);
1064         if (cpu == 0)
1065                 goto out;
1066         for (i = 0; i <= smp_cpu_mtid; i++)
1067                 if (cpu_online(cpu + i))
1068                         goto out;
1069         pcpu = pcpu_devices + cpu;
1070         rc = 0;
1071         switch (val) {
1072         case 0:
1073                 if (pcpu->state != CPU_STATE_CONFIGURED)
1074                         break;
1075                 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift);
1076                 if (rc)
1077                         break;
1078                 for (i = 0; i <= smp_cpu_mtid; i++) {
1079                         if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1080                                 continue;
1081                         pcpu[i].state = CPU_STATE_STANDBY;
1082                         smp_cpu_set_polarization(cpu + i,
1083                                                  POLARIZATION_UNKNOWN);
1084                 }
1085                 topology_expect_change();
1086                 break;
1087         case 1:
1088                 if (pcpu->state != CPU_STATE_STANDBY)
1089                         break;
1090                 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift);
1091                 if (rc)
1092                         break;
1093                 for (i = 0; i <= smp_cpu_mtid; i++) {
1094                         if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1095                                 continue;
1096                         pcpu[i].state = CPU_STATE_CONFIGURED;
1097                         smp_cpu_set_polarization(cpu + i,
1098                                                  POLARIZATION_UNKNOWN);
1099                 }
1100                 topology_expect_change();
1101                 break;
1102         default:
1103                 break;
1104         }
1105 out:
1106         mutex_unlock(&smp_cpu_state_mutex);
1107         put_online_cpus();
1108         return rc ? rc : count;
1109 }
1110 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
1111
1112 static ssize_t show_cpu_address(struct device *dev,
1113                                 struct device_attribute *attr, char *buf)
1114 {
1115         return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
1116 }
1117 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
1118
1119 static struct attribute *cpu_common_attrs[] = {
1120         &dev_attr_configure.attr,
1121         &dev_attr_address.attr,
1122         NULL,
1123 };
1124
1125 static struct attribute_group cpu_common_attr_group = {
1126         .attrs = cpu_common_attrs,
1127 };
1128
1129 static struct attribute *cpu_online_attrs[] = {
1130         &dev_attr_idle_count.attr,
1131         &dev_attr_idle_time_us.attr,
1132         NULL,
1133 };
1134
1135 static struct attribute_group cpu_online_attr_group = {
1136         .attrs = cpu_online_attrs,
1137 };
1138
1139 static int smp_cpu_online(unsigned int cpu)
1140 {
1141         struct device *s = &per_cpu(cpu_device, cpu)->dev;
1142
1143         return sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1144 }
1145
1146 static int smp_cpu_pre_down(unsigned int cpu)
1147 {
1148         struct device *s = &per_cpu(cpu_device, cpu)->dev;
1149
1150         sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1151         return 0;
1152 }
1153
1154 static int smp_add_present_cpu(int cpu)
1155 {
1156         struct device *s;
1157         struct cpu *c;
1158         int rc;
1159
1160         c = kzalloc(sizeof(*c), GFP_KERNEL);
1161         if (!c)
1162                 return -ENOMEM;
1163         per_cpu(cpu_device, cpu) = c;
1164         s = &c->dev;
1165         c->hotpluggable = 1;
1166         rc = register_cpu(c, cpu);
1167         if (rc)
1168                 goto out;
1169         rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1170         if (rc)
1171                 goto out_cpu;
1172         rc = topology_cpu_init(c);
1173         if (rc)
1174                 goto out_topology;
1175         return 0;
1176
1177 out_topology:
1178         sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1179 out_cpu:
1180         unregister_cpu(c);
1181 out:
1182         return rc;
1183 }
1184
1185 int __ref smp_rescan_cpus(void)
1186 {
1187         struct sclp_core_info *info;
1188         int nr;
1189
1190         info = kzalloc(sizeof(*info), GFP_KERNEL);
1191         if (!info)
1192                 return -ENOMEM;
1193         smp_get_core_info(info, 0);
1194         nr = __smp_rescan_cpus(info, false);
1195         kfree(info);
1196         if (nr)
1197                 topology_schedule_update();
1198         return 0;
1199 }
1200
1201 static ssize_t __ref rescan_store(struct device *dev,
1202                                   struct device_attribute *attr,
1203                                   const char *buf,
1204                                   size_t count)
1205 {
1206         int rc;
1207
1208         rc = lock_device_hotplug_sysfs();
1209         if (rc)
1210                 return rc;
1211         rc = smp_rescan_cpus();
1212         unlock_device_hotplug();
1213         return rc ? rc : count;
1214 }
1215 static DEVICE_ATTR_WO(rescan);
1216
1217 static int __init s390_smp_init(void)
1218 {
1219         int cpu, rc = 0;
1220
1221         rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1222         if (rc)
1223                 return rc;
1224         for_each_present_cpu(cpu) {
1225                 rc = smp_add_present_cpu(cpu);
1226                 if (rc)
1227                         goto out;
1228         }
1229
1230         rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "s390/smp:online",
1231                                smp_cpu_online, smp_cpu_pre_down);
1232         rc = rc <= 0 ? rc : 0;
1233 out:
1234         return rc;
1235 }
1236 subsys_initcall(s390_smp_init);
1237
1238 static __always_inline void set_new_lowcore(struct lowcore *lc)
1239 {
1240         union register_pair dst, src;
1241         u32 pfx;
1242
1243         src.even = (unsigned long) &S390_lowcore;
1244         src.odd  = sizeof(S390_lowcore);
1245         dst.even = (unsigned long) lc;
1246         dst.odd  = sizeof(*lc);
1247         pfx = (unsigned long) lc;
1248
1249         asm volatile(
1250                 "       mvcl    %[dst],%[src]\n"
1251                 "       spx     %[pfx]\n"
1252                 : [dst] "+&d" (dst.pair), [src] "+&d" (src.pair)
1253                 : [pfx] "Q" (pfx)
1254                 : "memory", "cc");
1255 }
1256
1257 static int __init smp_reinit_ipl_cpu(void)
1258 {
1259         unsigned long async_stack, nodat_stack, mcck_stack;
1260         struct lowcore *lc, *lc_ipl;
1261         unsigned long flags;
1262
1263         lc_ipl = lowcore_ptr[0];
1264         lc = (struct lowcore *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
1265         nodat_stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
1266         async_stack = stack_alloc();
1267         mcck_stack = stack_alloc();
1268         if (!lc || !nodat_stack || !async_stack || !mcck_stack)
1269                 panic("Couldn't allocate memory");
1270
1271         local_irq_save(flags);
1272         local_mcck_disable();
1273         set_new_lowcore(lc);
1274         S390_lowcore.nodat_stack = nodat_stack + STACK_INIT_OFFSET;
1275         S390_lowcore.async_stack = async_stack + STACK_INIT_OFFSET;
1276         S390_lowcore.mcck_stack = mcck_stack + STACK_INIT_OFFSET;
1277         lowcore_ptr[0] = lc;
1278         local_mcck_enable();
1279         local_irq_restore(flags);
1280
1281         free_pages(lc_ipl->async_stack - STACK_INIT_OFFSET, THREAD_SIZE_ORDER);
1282         memblock_free_late(lc_ipl->mcck_stack - STACK_INIT_OFFSET, THREAD_SIZE);
1283         memblock_free_late((unsigned long) lc_ipl, sizeof(*lc_ipl));
1284
1285         return 0;
1286 }
1287 early_initcall(smp_reinit_ipl_cpu);