1 /* 2 * SMP related functions 3 * 4 * Copyright IBM Corp. 1999, 2012 5 * Author(s): Denis Joseph Barrow, 6 * Martin Schwidefsky <schwidefsky@de.ibm.com>, 7 * Heiko Carstens <heiko.carstens@de.ibm.com>, 8 * 9 * based on other smp stuff by 10 * (c) 1995 Alan Cox, CymruNET Ltd <alan@cymru.net> 11 * (c) 1998 Ingo Molnar 12 * 13 * The code outside of smp.c uses logical cpu numbers, only smp.c does 14 * the translation of logical to physical cpu ids. All new code that 15 * operates on physical cpu numbers needs to go into smp.c. 16 */ 17 18 #define KMSG_COMPONENT "cpu" 19 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 20 21 #include <linux/workqueue.h> 22 #include <linux/module.h> 23 #include <linux/init.h> 24 #include <linux/mm.h> 25 #include <linux/err.h> 26 #include <linux/spinlock.h> 27 #include <linux/kernel_stat.h> 28 #include <linux/delay.h> 29 #include <linux/interrupt.h> 30 #include <linux/irqflags.h> 31 #include <linux/cpu.h> 32 #include <linux/slab.h> 33 #include <linux/crash_dump.h> 34 #include <asm/asm-offsets.h> 35 #include <asm/switch_to.h> 36 #include <asm/facility.h> 37 #include <asm/ipl.h> 38 #include <asm/setup.h> 39 #include <asm/irq.h> 40 #include <asm/tlbflush.h> 41 #include <asm/vtimer.h> 42 #include <asm/lowcore.h> 43 #include <asm/sclp.h> 44 #include <asm/vdso.h> 45 #include <asm/debug.h> 46 #include <asm/os_info.h> 47 #include <asm/sigp.h> 48 #include <asm/idle.h> 49 #include "entry.h" 50 51 enum { 52 ec_schedule = 0, 53 ec_call_function_single, 54 ec_stop_cpu, 55 }; 56 57 enum { 58 CPU_STATE_STANDBY, 59 CPU_STATE_CONFIGURED, 60 }; 61 62 struct pcpu { 63 struct cpu *cpu; 64 struct _lowcore *lowcore; /* lowcore page(s) for the cpu */ 65 unsigned long async_stack; /* async stack for the cpu */ 66 unsigned long panic_stack; /* panic stack for the cpu */ 67 unsigned long ec_mask; /* bit mask for ec_xxx functions */ 68 int state; /* physical cpu state */ 69 int polarization; /* physical polarization */ 70 u16 address; /* physical cpu address */ 71 }; 72 73 static u8 boot_cpu_type; 74 static u16 boot_cpu_address; 75 static struct pcpu pcpu_devices[NR_CPUS]; 76 77 /* 78 * The smp_cpu_state_mutex must be held when changing the state or polarization 79 * member of a pcpu data structure within the pcpu_devices arreay. 80 */ 81 DEFINE_MUTEX(smp_cpu_state_mutex); 82 83 /* 84 * Signal processor helper functions. 85 */ 86 static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm, 87 u32 *status) 88 { 89 int cc; 90 91 while (1) { 92 cc = __pcpu_sigp(addr, order, parm, NULL); 93 if (cc != SIGP_CC_BUSY) 94 return cc; 95 cpu_relax(); 96 } 97 } 98 99 static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm) 100 { 101 int cc, retry; 102 103 for (retry = 0; ; retry++) { 104 cc = __pcpu_sigp(pcpu->address, order, parm, NULL); 105 if (cc != SIGP_CC_BUSY) 106 break; 107 if (retry >= 3) 108 udelay(10); 109 } 110 return cc; 111 } 112 113 static inline int pcpu_stopped(struct pcpu *pcpu) 114 { 115 u32 uninitialized_var(status); 116 117 if (__pcpu_sigp(pcpu->address, SIGP_SENSE, 118 0, &status) != SIGP_CC_STATUS_STORED) 119 return 0; 120 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED)); 121 } 122 123 static inline int pcpu_running(struct pcpu *pcpu) 124 { 125 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING, 126 0, NULL) != SIGP_CC_STATUS_STORED) 127 return 1; 128 /* Status stored condition code is equivalent to cpu not running. */ 129 return 0; 130 } 131 132 /* 133 * Find struct pcpu by cpu address. 134 */ 135 static struct pcpu *pcpu_find_address(const struct cpumask *mask, int address) 136 { 137 int cpu; 138 139 for_each_cpu(cpu, mask) 140 if (pcpu_devices[cpu].address == address) 141 return pcpu_devices + cpu; 142 return NULL; 143 } 144 145 static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit) 146 { 147 int order; 148 149 if (test_and_set_bit(ec_bit, &pcpu->ec_mask)) 150 return; 151 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL; 152 pcpu_sigp_retry(pcpu, order, 0); 153 } 154 155 static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu) 156 { 157 struct _lowcore *lc; 158 159 if (pcpu != &pcpu_devices[0]) { 160 pcpu->lowcore = (struct _lowcore *) 161 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); 162 pcpu->async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER); 163 pcpu->panic_stack = __get_free_page(GFP_KERNEL); 164 if (!pcpu->lowcore || !pcpu->panic_stack || !pcpu->async_stack) 165 goto out; 166 } 167 lc = pcpu->lowcore; 168 memcpy(lc, &S390_lowcore, 512); 169 memset((char *) lc + 512, 0, sizeof(*lc) - 512); 170 lc->async_stack = pcpu->async_stack + ASYNC_SIZE 171 - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); 172 lc->panic_stack = pcpu->panic_stack + PAGE_SIZE 173 - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); 174 lc->cpu_nr = cpu; 175 lc->spinlock_lockval = arch_spin_lockval(cpu); 176 #ifndef CONFIG_64BIT 177 if (MACHINE_HAS_IEEE) { 178 lc->extended_save_area_addr = get_zeroed_page(GFP_KERNEL); 179 if (!lc->extended_save_area_addr) 180 goto out; 181 } 182 #else 183 if (MACHINE_HAS_VX) 184 lc->vector_save_area_addr = 185 (unsigned long) &lc->vector_save_area; 186 if (vdso_alloc_per_cpu(lc)) 187 goto out; 188 #endif 189 lowcore_ptr[cpu] = lc; 190 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc); 191 return 0; 192 out: 193 if (pcpu != &pcpu_devices[0]) { 194 free_page(pcpu->panic_stack); 195 free_pages(pcpu->async_stack, ASYNC_ORDER); 196 free_pages((unsigned long) pcpu->lowcore, LC_ORDER); 197 } 198 return -ENOMEM; 199 } 200 201 #ifdef CONFIG_HOTPLUG_CPU 202 203 static void pcpu_free_lowcore(struct pcpu *pcpu) 204 { 205 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0); 206 lowcore_ptr[pcpu - pcpu_devices] = NULL; 207 #ifndef CONFIG_64BIT 208 if (MACHINE_HAS_IEEE) { 209 struct _lowcore *lc = pcpu->lowcore; 210 211 free_page((unsigned long) lc->extended_save_area_addr); 212 lc->extended_save_area_addr = 0; 213 } 214 #else 215 vdso_free_per_cpu(pcpu->lowcore); 216 #endif 217 if (pcpu != &pcpu_devices[0]) { 218 free_page(pcpu->panic_stack); 219 free_pages(pcpu->async_stack, ASYNC_ORDER); 220 free_pages((unsigned long) pcpu->lowcore, LC_ORDER); 221 } 222 } 223 224 #endif /* CONFIG_HOTPLUG_CPU */ 225 226 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu) 227 { 228 struct _lowcore *lc = pcpu->lowcore; 229 230 if (MACHINE_HAS_TLB_LC) 231 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask); 232 cpumask_set_cpu(cpu, mm_cpumask(&init_mm)); 233 atomic_inc(&init_mm.context.attach_count); 234 lc->cpu_nr = cpu; 235 lc->spinlock_lockval = arch_spin_lockval(cpu); 236 lc->percpu_offset = __per_cpu_offset[cpu]; 237 lc->kernel_asce = S390_lowcore.kernel_asce; 238 lc->machine_flags = S390_lowcore.machine_flags; 239 lc->ftrace_func = S390_lowcore.ftrace_func; 240 lc->user_timer = lc->system_timer = lc->steal_timer = 0; 241 __ctl_store(lc->cregs_save_area, 0, 15); 242 save_access_regs((unsigned int *) lc->access_regs_save_area); 243 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list, 244 MAX_FACILITY_BIT/8); 245 } 246 247 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk) 248 { 249 struct _lowcore *lc = pcpu->lowcore; 250 struct thread_info *ti = task_thread_info(tsk); 251 252 lc->kernel_stack = (unsigned long) task_stack_page(tsk) 253 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); 254 lc->thread_info = (unsigned long) task_thread_info(tsk); 255 lc->current_task = (unsigned long) tsk; 256 lc->user_timer = ti->user_timer; 257 lc->system_timer = ti->system_timer; 258 lc->steal_timer = 0; 259 } 260 261 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data) 262 { 263 struct _lowcore *lc = pcpu->lowcore; 264 265 lc->restart_stack = lc->kernel_stack; 266 lc->restart_fn = (unsigned long) func; 267 lc->restart_data = (unsigned long) data; 268 lc->restart_source = -1UL; 269 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0); 270 } 271 272 /* 273 * Call function via PSW restart on pcpu and stop the current cpu. 274 */ 275 static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *), 276 void *data, unsigned long stack) 277 { 278 struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices]; 279 unsigned long source_cpu = stap(); 280 281 __load_psw_mask(PSW_KERNEL_BITS); 282 if (pcpu->address == source_cpu) 283 func(data); /* should not return */ 284 /* Stop target cpu (if func returns this stops the current cpu). */ 285 pcpu_sigp_retry(pcpu, SIGP_STOP, 0); 286 /* Restart func on the target cpu and stop the current cpu. */ 287 mem_assign_absolute(lc->restart_stack, stack); 288 mem_assign_absolute(lc->restart_fn, (unsigned long) func); 289 mem_assign_absolute(lc->restart_data, (unsigned long) data); 290 mem_assign_absolute(lc->restart_source, source_cpu); 291 asm volatile( 292 "0: sigp 0,%0,%2 # sigp restart to target cpu\n" 293 " brc 2,0b # busy, try again\n" 294 "1: sigp 0,%1,%3 # sigp stop to current cpu\n" 295 " brc 2,1b # busy, try again\n" 296 : : "d" (pcpu->address), "d" (source_cpu), 297 "K" (SIGP_RESTART), "K" (SIGP_STOP) 298 : "0", "1", "cc"); 299 for (;;) ; 300 } 301 302 /* 303 * Call function on an online CPU. 304 */ 305 void smp_call_online_cpu(void (*func)(void *), void *data) 306 { 307 struct pcpu *pcpu; 308 309 /* Use the current cpu if it is online. */ 310 pcpu = pcpu_find_address(cpu_online_mask, stap()); 311 if (!pcpu) 312 /* Use the first online cpu. */ 313 pcpu = pcpu_devices + cpumask_first(cpu_online_mask); 314 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack); 315 } 316 317 /* 318 * Call function on the ipl CPU. 319 */ 320 void smp_call_ipl_cpu(void (*func)(void *), void *data) 321 { 322 pcpu_delegate(&pcpu_devices[0], func, data, 323 pcpu_devices->panic_stack + PAGE_SIZE); 324 } 325 326 int smp_find_processor_id(u16 address) 327 { 328 int cpu; 329 330 for_each_present_cpu(cpu) 331 if (pcpu_devices[cpu].address == address) 332 return cpu; 333 return -1; 334 } 335 336 int smp_vcpu_scheduled(int cpu) 337 { 338 return pcpu_running(pcpu_devices + cpu); 339 } 340 341 void smp_yield_cpu(int cpu) 342 { 343 if (MACHINE_HAS_DIAG9C) 344 asm volatile("diag %0,0,0x9c" 345 : : "d" (pcpu_devices[cpu].address)); 346 else if (MACHINE_HAS_DIAG44) 347 asm volatile("diag 0,0,0x44"); 348 } 349 350 /* 351 * Send cpus emergency shutdown signal. This gives the cpus the 352 * opportunity to complete outstanding interrupts. 353 */ 354 static void smp_emergency_stop(cpumask_t *cpumask) 355 { 356 u64 end; 357 int cpu; 358 359 end = get_tod_clock() + (1000000UL << 12); 360 for_each_cpu(cpu, cpumask) { 361 struct pcpu *pcpu = pcpu_devices + cpu; 362 set_bit(ec_stop_cpu, &pcpu->ec_mask); 363 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL, 364 0, NULL) == SIGP_CC_BUSY && 365 get_tod_clock() < end) 366 cpu_relax(); 367 } 368 while (get_tod_clock() < end) { 369 for_each_cpu(cpu, cpumask) 370 if (pcpu_stopped(pcpu_devices + cpu)) 371 cpumask_clear_cpu(cpu, cpumask); 372 if (cpumask_empty(cpumask)) 373 break; 374 cpu_relax(); 375 } 376 } 377 378 /* 379 * Stop all cpus but the current one. 380 */ 381 void smp_send_stop(void) 382 { 383 cpumask_t cpumask; 384 int cpu; 385 386 /* Disable all interrupts/machine checks */ 387 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); 388 trace_hardirqs_off(); 389 390 debug_set_critical(); 391 cpumask_copy(&cpumask, cpu_online_mask); 392 cpumask_clear_cpu(smp_processor_id(), &cpumask); 393 394 if (oops_in_progress) 395 smp_emergency_stop(&cpumask); 396 397 /* stop all processors */ 398 for_each_cpu(cpu, &cpumask) { 399 struct pcpu *pcpu = pcpu_devices + cpu; 400 pcpu_sigp_retry(pcpu, SIGP_STOP, 0); 401 while (!pcpu_stopped(pcpu)) 402 cpu_relax(); 403 } 404 } 405 406 /* 407 * This is the main routine where commands issued by other 408 * cpus are handled. 409 */ 410 static void smp_handle_ext_call(void) 411 { 412 unsigned long bits; 413 414 /* handle bit signal external calls */ 415 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0); 416 if (test_bit(ec_stop_cpu, &bits)) 417 smp_stop_cpu(); 418 if (test_bit(ec_schedule, &bits)) 419 scheduler_ipi(); 420 if (test_bit(ec_call_function_single, &bits)) 421 generic_smp_call_function_single_interrupt(); 422 } 423 424 static void do_ext_call_interrupt(struct ext_code ext_code, 425 unsigned int param32, unsigned long param64) 426 { 427 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS); 428 smp_handle_ext_call(); 429 } 430 431 void arch_send_call_function_ipi_mask(const struct cpumask *mask) 432 { 433 int cpu; 434 435 for_each_cpu(cpu, mask) 436 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); 437 } 438 439 void arch_send_call_function_single_ipi(int cpu) 440 { 441 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); 442 } 443 444 #ifndef CONFIG_64BIT 445 /* 446 * this function sends a 'purge tlb' signal to another CPU. 447 */ 448 static void smp_ptlb_callback(void *info) 449 { 450 __tlb_flush_local(); 451 } 452 453 void smp_ptlb_all(void) 454 { 455 on_each_cpu(smp_ptlb_callback, NULL, 1); 456 } 457 EXPORT_SYMBOL(smp_ptlb_all); 458 #endif /* ! CONFIG_64BIT */ 459 460 /* 461 * this function sends a 'reschedule' IPI to another CPU. 462 * it goes straight through and wastes no time serializing 463 * anything. Worst case is that we lose a reschedule ... 464 */ 465 void smp_send_reschedule(int cpu) 466 { 467 pcpu_ec_call(pcpu_devices + cpu, ec_schedule); 468 } 469 470 /* 471 * parameter area for the set/clear control bit callbacks 472 */ 473 struct ec_creg_mask_parms { 474 unsigned long orval; 475 unsigned long andval; 476 int cr; 477 }; 478 479 /* 480 * callback for setting/clearing control bits 481 */ 482 static void smp_ctl_bit_callback(void *info) 483 { 484 struct ec_creg_mask_parms *pp = info; 485 unsigned long cregs[16]; 486 487 __ctl_store(cregs, 0, 15); 488 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval; 489 __ctl_load(cregs, 0, 15); 490 } 491 492 /* 493 * Set a bit in a control register of all cpus 494 */ 495 void smp_ctl_set_bit(int cr, int bit) 496 { 497 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr }; 498 499 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 500 } 501 EXPORT_SYMBOL(smp_ctl_set_bit); 502 503 /* 504 * Clear a bit in a control register of all cpus 505 */ 506 void smp_ctl_clear_bit(int cr, int bit) 507 { 508 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr }; 509 510 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 511 } 512 EXPORT_SYMBOL(smp_ctl_clear_bit); 513 514 #ifdef CONFIG_CRASH_DUMP 515 516 static void __init smp_get_save_area(int cpu, u16 address) 517 { 518 void *lc = pcpu_devices[0].lowcore; 519 struct save_area_ext *sa_ext; 520 unsigned long vx_sa; 521 522 if (is_kdump_kernel()) 523 return; 524 if (!OLDMEM_BASE && (address == boot_cpu_address || 525 ipl_info.type != IPL_TYPE_FCP_DUMP)) 526 return; 527 sa_ext = dump_save_area_create(cpu); 528 if (!sa_ext) 529 panic("could not allocate memory for save area\n"); 530 if (address == boot_cpu_address) { 531 /* Copy the registers of the boot cpu. */ 532 copy_oldmem_page(1, (void *) &sa_ext->sa, sizeof(sa_ext->sa), 533 SAVE_AREA_BASE - PAGE_SIZE, 0); 534 if (MACHINE_HAS_VX) 535 save_vx_regs_safe(sa_ext->vx_regs); 536 return; 537 } 538 /* Get the registers of a non-boot cpu. */ 539 __pcpu_sigp_relax(address, SIGP_STOP_AND_STORE_STATUS, 0, NULL); 540 memcpy_real(&sa_ext->sa, lc + SAVE_AREA_BASE, sizeof(sa_ext->sa)); 541 if (!MACHINE_HAS_VX) 542 return; 543 /* Get the VX registers */ 544 vx_sa = __get_free_page(GFP_KERNEL); 545 if (!vx_sa) 546 panic("could not allocate memory for VX save area\n"); 547 __pcpu_sigp_relax(address, SIGP_STORE_ADDITIONAL_STATUS, vx_sa, NULL); 548 memcpy(sa_ext->vx_regs, (void *) vx_sa, sizeof(sa_ext->vx_regs)); 549 free_page(vx_sa); 550 } 551 552 int smp_store_status(int cpu) 553 { 554 unsigned long vx_sa; 555 struct pcpu *pcpu; 556 557 pcpu = pcpu_devices + cpu; 558 if (__pcpu_sigp_relax(pcpu->address, SIGP_STOP_AND_STORE_STATUS, 559 0, NULL) != SIGP_CC_ORDER_CODE_ACCEPTED) 560 return -EIO; 561 if (!MACHINE_HAS_VX) 562 return 0; 563 vx_sa = __pa(pcpu->lowcore->vector_save_area_addr); 564 __pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS, 565 vx_sa, NULL); 566 return 0; 567 } 568 569 #else /* CONFIG_CRASH_DUMP */ 570 571 static inline void smp_get_save_area(int cpu, u16 address) { } 572 573 #endif /* CONFIG_CRASH_DUMP */ 574 575 void smp_cpu_set_polarization(int cpu, int val) 576 { 577 pcpu_devices[cpu].polarization = val; 578 } 579 580 int smp_cpu_get_polarization(int cpu) 581 { 582 return pcpu_devices[cpu].polarization; 583 } 584 585 static struct sclp_cpu_info *smp_get_cpu_info(void) 586 { 587 static int use_sigp_detection; 588 struct sclp_cpu_info *info; 589 int address; 590 591 info = kzalloc(sizeof(*info), GFP_KERNEL); 592 if (info && (use_sigp_detection || sclp_get_cpu_info(info))) { 593 use_sigp_detection = 1; 594 for (address = 0; address <= MAX_CPU_ADDRESS; address++) { 595 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0, NULL) == 596 SIGP_CC_NOT_OPERATIONAL) 597 continue; 598 info->cpu[info->configured].address = address; 599 info->configured++; 600 } 601 info->combined = info->configured; 602 } 603 return info; 604 } 605 606 static int smp_add_present_cpu(int cpu); 607 608 static int __smp_rescan_cpus(struct sclp_cpu_info *info, int sysfs_add) 609 { 610 struct pcpu *pcpu; 611 cpumask_t avail; 612 int cpu, nr, i; 613 614 nr = 0; 615 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask); 616 cpu = cpumask_first(&avail); 617 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) { 618 if (info->has_cpu_type && info->cpu[i].type != boot_cpu_type) 619 continue; 620 if (pcpu_find_address(cpu_present_mask, info->cpu[i].address)) 621 continue; 622 pcpu = pcpu_devices + cpu; 623 pcpu->address = info->cpu[i].address; 624 pcpu->state = (i >= info->configured) ? 625 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED; 626 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 627 set_cpu_present(cpu, true); 628 if (sysfs_add && smp_add_present_cpu(cpu) != 0) 629 set_cpu_present(cpu, false); 630 else 631 nr++; 632 cpu = cpumask_next(cpu, &avail); 633 } 634 return nr; 635 } 636 637 static void __init smp_detect_cpus(void) 638 { 639 unsigned int cpu, c_cpus, s_cpus; 640 struct sclp_cpu_info *info; 641 642 info = smp_get_cpu_info(); 643 if (!info) 644 panic("smp_detect_cpus failed to allocate memory\n"); 645 if (info->has_cpu_type) { 646 for (cpu = 0; cpu < info->combined; cpu++) { 647 if (info->cpu[cpu].address != boot_cpu_address) 648 continue; 649 /* The boot cpu dictates the cpu type. */ 650 boot_cpu_type = info->cpu[cpu].type; 651 break; 652 } 653 } 654 c_cpus = s_cpus = 0; 655 for (cpu = 0; cpu < info->combined; cpu++) { 656 if (info->has_cpu_type && info->cpu[cpu].type != boot_cpu_type) 657 continue; 658 if (cpu < info->configured) { 659 smp_get_save_area(c_cpus, info->cpu[cpu].address); 660 c_cpus++; 661 } else 662 s_cpus++; 663 } 664 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus); 665 get_online_cpus(); 666 __smp_rescan_cpus(info, 0); 667 put_online_cpus(); 668 kfree(info); 669 } 670 671 /* 672 * Activate a secondary processor. 673 */ 674 static void smp_start_secondary(void *cpuvoid) 675 { 676 S390_lowcore.last_update_clock = get_tod_clock(); 677 S390_lowcore.restart_stack = (unsigned long) restart_stack; 678 S390_lowcore.restart_fn = (unsigned long) do_restart; 679 S390_lowcore.restart_data = 0; 680 S390_lowcore.restart_source = -1UL; 681 restore_access_regs(S390_lowcore.access_regs_save_area); 682 __ctl_load(S390_lowcore.cregs_save_area, 0, 15); 683 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); 684 cpu_init(); 685 preempt_disable(); 686 init_cpu_timer(); 687 vtime_init(); 688 pfault_init(); 689 notify_cpu_starting(smp_processor_id()); 690 set_cpu_online(smp_processor_id(), true); 691 inc_irq_stat(CPU_RST); 692 local_irq_enable(); 693 cpu_startup_entry(CPUHP_ONLINE); 694 } 695 696 /* Upping and downing of CPUs */ 697 int __cpu_up(unsigned int cpu, struct task_struct *tidle) 698 { 699 struct pcpu *pcpu; 700 int rc; 701 702 pcpu = pcpu_devices + cpu; 703 if (pcpu->state != CPU_STATE_CONFIGURED) 704 return -EIO; 705 if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) != 706 SIGP_CC_ORDER_CODE_ACCEPTED) 707 return -EIO; 708 709 rc = pcpu_alloc_lowcore(pcpu, cpu); 710 if (rc) 711 return rc; 712 pcpu_prepare_secondary(pcpu, cpu); 713 pcpu_attach_task(pcpu, tidle); 714 pcpu_start_fn(pcpu, smp_start_secondary, NULL); 715 while (!cpu_online(cpu)) 716 cpu_relax(); 717 return 0; 718 } 719 720 static unsigned int setup_possible_cpus __initdata; 721 722 static int __init _setup_possible_cpus(char *s) 723 { 724 get_option(&s, &setup_possible_cpus); 725 return 0; 726 } 727 early_param("possible_cpus", _setup_possible_cpus); 728 729 #ifdef CONFIG_HOTPLUG_CPU 730 731 int __cpu_disable(void) 732 { 733 unsigned long cregs[16]; 734 735 /* Handle possible pending IPIs */ 736 smp_handle_ext_call(); 737 set_cpu_online(smp_processor_id(), false); 738 /* Disable pseudo page faults on this cpu. */ 739 pfault_fini(); 740 /* Disable interrupt sources via control register. */ 741 __ctl_store(cregs, 0, 15); 742 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */ 743 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */ 744 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */ 745 __ctl_load(cregs, 0, 15); 746 clear_cpu_flag(CIF_NOHZ_DELAY); 747 return 0; 748 } 749 750 void __cpu_die(unsigned int cpu) 751 { 752 struct pcpu *pcpu; 753 754 /* Wait until target cpu is down */ 755 pcpu = pcpu_devices + cpu; 756 while (!pcpu_stopped(pcpu)) 757 cpu_relax(); 758 pcpu_free_lowcore(pcpu); 759 atomic_dec(&init_mm.context.attach_count); 760 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm)); 761 if (MACHINE_HAS_TLB_LC) 762 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask); 763 } 764 765 void __noreturn cpu_die(void) 766 { 767 idle_task_exit(); 768 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0); 769 for (;;) ; 770 } 771 772 #endif /* CONFIG_HOTPLUG_CPU */ 773 774 void __init smp_fill_possible_mask(void) 775 { 776 unsigned int possible, sclp, cpu; 777 778 sclp = sclp_get_max_cpu() ?: nr_cpu_ids; 779 possible = setup_possible_cpus ?: nr_cpu_ids; 780 possible = min(possible, sclp); 781 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++) 782 set_cpu_possible(cpu, true); 783 } 784 785 void __init smp_prepare_cpus(unsigned int max_cpus) 786 { 787 /* request the 0x1201 emergency signal external interrupt */ 788 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt)) 789 panic("Couldn't request external interrupt 0x1201"); 790 /* request the 0x1202 external call external interrupt */ 791 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt)) 792 panic("Couldn't request external interrupt 0x1202"); 793 smp_detect_cpus(); 794 } 795 796 void __init smp_prepare_boot_cpu(void) 797 { 798 struct pcpu *pcpu = pcpu_devices; 799 800 boot_cpu_address = stap(); 801 pcpu->state = CPU_STATE_CONFIGURED; 802 pcpu->address = boot_cpu_address; 803 pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix(); 804 pcpu->async_stack = S390_lowcore.async_stack - ASYNC_SIZE 805 + STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); 806 pcpu->panic_stack = S390_lowcore.panic_stack - PAGE_SIZE 807 + STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); 808 S390_lowcore.percpu_offset = __per_cpu_offset[0]; 809 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN); 810 set_cpu_present(0, true); 811 set_cpu_online(0, true); 812 } 813 814 void __init smp_cpus_done(unsigned int max_cpus) 815 { 816 } 817 818 void __init smp_setup_processor_id(void) 819 { 820 S390_lowcore.cpu_nr = 0; 821 S390_lowcore.spinlock_lockval = arch_spin_lockval(0); 822 } 823 824 /* 825 * the frequency of the profiling timer can be changed 826 * by writing a multiplier value into /proc/profile. 827 * 828 * usually you want to run this on all CPUs ;) 829 */ 830 int setup_profiling_timer(unsigned int multiplier) 831 { 832 return 0; 833 } 834 835 #ifdef CONFIG_HOTPLUG_CPU 836 static ssize_t cpu_configure_show(struct device *dev, 837 struct device_attribute *attr, char *buf) 838 { 839 ssize_t count; 840 841 mutex_lock(&smp_cpu_state_mutex); 842 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state); 843 mutex_unlock(&smp_cpu_state_mutex); 844 return count; 845 } 846 847 static ssize_t cpu_configure_store(struct device *dev, 848 struct device_attribute *attr, 849 const char *buf, size_t count) 850 { 851 struct pcpu *pcpu; 852 int cpu, val, rc; 853 char delim; 854 855 if (sscanf(buf, "%d %c", &val, &delim) != 1) 856 return -EINVAL; 857 if (val != 0 && val != 1) 858 return -EINVAL; 859 get_online_cpus(); 860 mutex_lock(&smp_cpu_state_mutex); 861 rc = -EBUSY; 862 /* disallow configuration changes of online cpus and cpu 0 */ 863 cpu = dev->id; 864 if (cpu_online(cpu) || cpu == 0) 865 goto out; 866 pcpu = pcpu_devices + cpu; 867 rc = 0; 868 switch (val) { 869 case 0: 870 if (pcpu->state != CPU_STATE_CONFIGURED) 871 break; 872 rc = sclp_cpu_deconfigure(pcpu->address); 873 if (rc) 874 break; 875 pcpu->state = CPU_STATE_STANDBY; 876 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 877 topology_expect_change(); 878 break; 879 case 1: 880 if (pcpu->state != CPU_STATE_STANDBY) 881 break; 882 rc = sclp_cpu_configure(pcpu->address); 883 if (rc) 884 break; 885 pcpu->state = CPU_STATE_CONFIGURED; 886 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 887 topology_expect_change(); 888 break; 889 default: 890 break; 891 } 892 out: 893 mutex_unlock(&smp_cpu_state_mutex); 894 put_online_cpus(); 895 return rc ? rc : count; 896 } 897 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store); 898 #endif /* CONFIG_HOTPLUG_CPU */ 899 900 static ssize_t show_cpu_address(struct device *dev, 901 struct device_attribute *attr, char *buf) 902 { 903 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address); 904 } 905 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL); 906 907 static struct attribute *cpu_common_attrs[] = { 908 #ifdef CONFIG_HOTPLUG_CPU 909 &dev_attr_configure.attr, 910 #endif 911 &dev_attr_address.attr, 912 NULL, 913 }; 914 915 static struct attribute_group cpu_common_attr_group = { 916 .attrs = cpu_common_attrs, 917 }; 918 919 static struct attribute *cpu_online_attrs[] = { 920 &dev_attr_idle_count.attr, 921 &dev_attr_idle_time_us.attr, 922 NULL, 923 }; 924 925 static struct attribute_group cpu_online_attr_group = { 926 .attrs = cpu_online_attrs, 927 }; 928 929 static int smp_cpu_notify(struct notifier_block *self, unsigned long action, 930 void *hcpu) 931 { 932 unsigned int cpu = (unsigned int)(long)hcpu; 933 struct cpu *c = pcpu_devices[cpu].cpu; 934 struct device *s = &c->dev; 935 int err = 0; 936 937 switch (action & ~CPU_TASKS_FROZEN) { 938 case CPU_ONLINE: 939 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 940 break; 941 case CPU_DEAD: 942 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 943 break; 944 } 945 return notifier_from_errno(err); 946 } 947 948 static int smp_add_present_cpu(int cpu) 949 { 950 struct device *s; 951 struct cpu *c; 952 int rc; 953 954 c = kzalloc(sizeof(*c), GFP_KERNEL); 955 if (!c) 956 return -ENOMEM; 957 pcpu_devices[cpu].cpu = c; 958 s = &c->dev; 959 c->hotpluggable = 1; 960 rc = register_cpu(c, cpu); 961 if (rc) 962 goto out; 963 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group); 964 if (rc) 965 goto out_cpu; 966 if (cpu_online(cpu)) { 967 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 968 if (rc) 969 goto out_online; 970 } 971 rc = topology_cpu_init(c); 972 if (rc) 973 goto out_topology; 974 return 0; 975 976 out_topology: 977 if (cpu_online(cpu)) 978 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 979 out_online: 980 sysfs_remove_group(&s->kobj, &cpu_common_attr_group); 981 out_cpu: 982 #ifdef CONFIG_HOTPLUG_CPU 983 unregister_cpu(c); 984 #endif 985 out: 986 return rc; 987 } 988 989 #ifdef CONFIG_HOTPLUG_CPU 990 991 int __ref smp_rescan_cpus(void) 992 { 993 struct sclp_cpu_info *info; 994 int nr; 995 996 info = smp_get_cpu_info(); 997 if (!info) 998 return -ENOMEM; 999 get_online_cpus(); 1000 mutex_lock(&smp_cpu_state_mutex); 1001 nr = __smp_rescan_cpus(info, 1); 1002 mutex_unlock(&smp_cpu_state_mutex); 1003 put_online_cpus(); 1004 kfree(info); 1005 if (nr) 1006 topology_schedule_update(); 1007 return 0; 1008 } 1009 1010 static ssize_t __ref rescan_store(struct device *dev, 1011 struct device_attribute *attr, 1012 const char *buf, 1013 size_t count) 1014 { 1015 int rc; 1016 1017 rc = smp_rescan_cpus(); 1018 return rc ? rc : count; 1019 } 1020 static DEVICE_ATTR(rescan, 0200, NULL, rescan_store); 1021 #endif /* CONFIG_HOTPLUG_CPU */ 1022 1023 static int __init s390_smp_init(void) 1024 { 1025 int cpu, rc = 0; 1026 1027 #ifdef CONFIG_HOTPLUG_CPU 1028 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan); 1029 if (rc) 1030 return rc; 1031 #endif 1032 cpu_notifier_register_begin(); 1033 for_each_present_cpu(cpu) { 1034 rc = smp_add_present_cpu(cpu); 1035 if (rc) 1036 goto out; 1037 } 1038 1039 __hotcpu_notifier(smp_cpu_notify, 0); 1040 1041 out: 1042 cpu_notifier_register_done(); 1043 return rc; 1044 } 1045 subsys_initcall(s390_smp_init); 1046