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