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 "entry.h" 49 50 enum { 51 ec_schedule = 0, 52 ec_call_function_single, 53 ec_stop_cpu, 54 }; 55 56 enum { 57 CPU_STATE_STANDBY, 58 CPU_STATE_CONFIGURED, 59 }; 60 61 struct pcpu { 62 struct cpu *cpu; 63 struct _lowcore *lowcore; /* lowcore page(s) for the cpu */ 64 unsigned long async_stack; /* async stack for the cpu */ 65 unsigned long panic_stack; /* panic stack for the cpu */ 66 unsigned long ec_mask; /* bit mask for ec_xxx functions */ 67 int state; /* physical cpu state */ 68 int polarization; /* physical polarization */ 69 u16 address; /* physical cpu address */ 70 }; 71 72 static u8 boot_cpu_type; 73 static u16 boot_cpu_address; 74 static struct pcpu pcpu_devices[NR_CPUS]; 75 76 /* 77 * The smp_cpu_state_mutex must be held when changing the state or polarization 78 * member of a pcpu data structure within the pcpu_devices arreay. 79 */ 80 DEFINE_MUTEX(smp_cpu_state_mutex); 81 82 /* 83 * Signal processor helper functions. 84 */ 85 static inline int __pcpu_sigp(u16 addr, u8 order, u32 parm, u32 *status) 86 { 87 register unsigned int reg1 asm ("1") = parm; 88 int cc; 89 90 asm volatile( 91 " sigp %1,%2,0(%3)\n" 92 " ipm %0\n" 93 " srl %0,28\n" 94 : "=d" (cc), "+d" (reg1) : "d" (addr), "a" (order) : "cc"); 95 if (status && cc == 1) 96 *status = reg1; 97 return cc; 98 } 99 100 static inline int __pcpu_sigp_relax(u16 addr, u8 order, u32 parm, u32 *status) 101 { 102 int cc; 103 104 while (1) { 105 cc = __pcpu_sigp(addr, order, parm, NULL); 106 if (cc != SIGP_CC_BUSY) 107 return cc; 108 cpu_relax(); 109 } 110 } 111 112 static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm) 113 { 114 int cc, retry; 115 116 for (retry = 0; ; retry++) { 117 cc = __pcpu_sigp(pcpu->address, order, parm, NULL); 118 if (cc != SIGP_CC_BUSY) 119 break; 120 if (retry >= 3) 121 udelay(10); 122 } 123 return cc; 124 } 125 126 static inline int pcpu_stopped(struct pcpu *pcpu) 127 { 128 u32 uninitialized_var(status); 129 130 if (__pcpu_sigp(pcpu->address, SIGP_SENSE, 131 0, &status) != SIGP_CC_STATUS_STORED) 132 return 0; 133 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED)); 134 } 135 136 static inline int pcpu_running(struct pcpu *pcpu) 137 { 138 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING, 139 0, NULL) != SIGP_CC_STATUS_STORED) 140 return 1; 141 /* Status stored condition code is equivalent to cpu not running. */ 142 return 0; 143 } 144 145 /* 146 * Find struct pcpu by cpu address. 147 */ 148 static struct pcpu *pcpu_find_address(const struct cpumask *mask, int address) 149 { 150 int cpu; 151 152 for_each_cpu(cpu, mask) 153 if (pcpu_devices[cpu].address == address) 154 return pcpu_devices + cpu; 155 return NULL; 156 } 157 158 static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit) 159 { 160 int order; 161 162 if (test_and_set_bit(ec_bit, &pcpu->ec_mask)) 163 return; 164 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL; 165 pcpu_sigp_retry(pcpu, order, 0); 166 } 167 168 static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu) 169 { 170 struct _lowcore *lc; 171 172 if (pcpu != &pcpu_devices[0]) { 173 pcpu->lowcore = (struct _lowcore *) 174 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); 175 pcpu->async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER); 176 pcpu->panic_stack = __get_free_page(GFP_KERNEL); 177 if (!pcpu->lowcore || !pcpu->panic_stack || !pcpu->async_stack) 178 goto out; 179 } 180 lc = pcpu->lowcore; 181 memcpy(lc, &S390_lowcore, 512); 182 memset((char *) lc + 512, 0, sizeof(*lc) - 512); 183 lc->async_stack = pcpu->async_stack + ASYNC_SIZE 184 - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); 185 lc->panic_stack = pcpu->panic_stack + PAGE_SIZE 186 - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); 187 lc->cpu_nr = cpu; 188 #ifndef CONFIG_64BIT 189 if (MACHINE_HAS_IEEE) { 190 lc->extended_save_area_addr = get_zeroed_page(GFP_KERNEL); 191 if (!lc->extended_save_area_addr) 192 goto out; 193 } 194 #else 195 if (vdso_alloc_per_cpu(lc)) 196 goto out; 197 #endif 198 lowcore_ptr[cpu] = lc; 199 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc); 200 return 0; 201 out: 202 if (pcpu != &pcpu_devices[0]) { 203 free_page(pcpu->panic_stack); 204 free_pages(pcpu->async_stack, ASYNC_ORDER); 205 free_pages((unsigned long) pcpu->lowcore, LC_ORDER); 206 } 207 return -ENOMEM; 208 } 209 210 #ifdef CONFIG_HOTPLUG_CPU 211 212 static void pcpu_free_lowcore(struct pcpu *pcpu) 213 { 214 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0); 215 lowcore_ptr[pcpu - pcpu_devices] = NULL; 216 #ifndef CONFIG_64BIT 217 if (MACHINE_HAS_IEEE) { 218 struct _lowcore *lc = pcpu->lowcore; 219 220 free_page((unsigned long) lc->extended_save_area_addr); 221 lc->extended_save_area_addr = 0; 222 } 223 #else 224 vdso_free_per_cpu(pcpu->lowcore); 225 #endif 226 if (pcpu != &pcpu_devices[0]) { 227 free_page(pcpu->panic_stack); 228 free_pages(pcpu->async_stack, ASYNC_ORDER); 229 free_pages((unsigned long) pcpu->lowcore, LC_ORDER); 230 } 231 } 232 233 #endif /* CONFIG_HOTPLUG_CPU */ 234 235 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu) 236 { 237 struct _lowcore *lc = pcpu->lowcore; 238 239 if (MACHINE_HAS_TLB_LC) 240 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask); 241 cpumask_set_cpu(cpu, mm_cpumask(&init_mm)); 242 atomic_inc(&init_mm.context.attach_count); 243 lc->cpu_nr = cpu; 244 lc->percpu_offset = __per_cpu_offset[cpu]; 245 lc->kernel_asce = S390_lowcore.kernel_asce; 246 lc->machine_flags = S390_lowcore.machine_flags; 247 lc->ftrace_func = S390_lowcore.ftrace_func; 248 lc->user_timer = lc->system_timer = lc->steal_timer = 0; 249 __ctl_store(lc->cregs_save_area, 0, 15); 250 save_access_regs((unsigned int *) lc->access_regs_save_area); 251 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list, 252 MAX_FACILITY_BIT/8); 253 } 254 255 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk) 256 { 257 struct _lowcore *lc = pcpu->lowcore; 258 struct thread_info *ti = task_thread_info(tsk); 259 260 lc->kernel_stack = (unsigned long) task_stack_page(tsk) 261 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); 262 lc->thread_info = (unsigned long) task_thread_info(tsk); 263 lc->current_task = (unsigned long) tsk; 264 lc->user_timer = ti->user_timer; 265 lc->system_timer = ti->system_timer; 266 lc->steal_timer = 0; 267 } 268 269 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data) 270 { 271 struct _lowcore *lc = pcpu->lowcore; 272 273 lc->restart_stack = lc->kernel_stack; 274 lc->restart_fn = (unsigned long) func; 275 lc->restart_data = (unsigned long) data; 276 lc->restart_source = -1UL; 277 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0); 278 } 279 280 /* 281 * Call function via PSW restart on pcpu and stop the current cpu. 282 */ 283 static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *), 284 void *data, unsigned long stack) 285 { 286 struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices]; 287 unsigned long source_cpu = stap(); 288 289 __load_psw_mask(PSW_KERNEL_BITS); 290 if (pcpu->address == source_cpu) 291 func(data); /* should not return */ 292 /* Stop target cpu (if func returns this stops the current cpu). */ 293 pcpu_sigp_retry(pcpu, SIGP_STOP, 0); 294 /* Restart func on the target cpu and stop the current cpu. */ 295 mem_assign_absolute(lc->restart_stack, stack); 296 mem_assign_absolute(lc->restart_fn, (unsigned long) func); 297 mem_assign_absolute(lc->restart_data, (unsigned long) data); 298 mem_assign_absolute(lc->restart_source, source_cpu); 299 asm volatile( 300 "0: sigp 0,%0,%2 # sigp restart to target cpu\n" 301 " brc 2,0b # busy, try again\n" 302 "1: sigp 0,%1,%3 # sigp stop to current cpu\n" 303 " brc 2,1b # busy, try again\n" 304 : : "d" (pcpu->address), "d" (source_cpu), 305 "K" (SIGP_RESTART), "K" (SIGP_STOP) 306 : "0", "1", "cc"); 307 for (;;) ; 308 } 309 310 /* 311 * Call function on an online CPU. 312 */ 313 void smp_call_online_cpu(void (*func)(void *), void *data) 314 { 315 struct pcpu *pcpu; 316 317 /* Use the current cpu if it is online. */ 318 pcpu = pcpu_find_address(cpu_online_mask, stap()); 319 if (!pcpu) 320 /* Use the first online cpu. */ 321 pcpu = pcpu_devices + cpumask_first(cpu_online_mask); 322 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack); 323 } 324 325 /* 326 * Call function on the ipl CPU. 327 */ 328 void smp_call_ipl_cpu(void (*func)(void *), void *data) 329 { 330 pcpu_delegate(&pcpu_devices[0], func, data, 331 pcpu_devices->panic_stack + PAGE_SIZE); 332 } 333 334 int smp_find_processor_id(u16 address) 335 { 336 int cpu; 337 338 for_each_present_cpu(cpu) 339 if (pcpu_devices[cpu].address == address) 340 return cpu; 341 return -1; 342 } 343 344 int smp_vcpu_scheduled(int cpu) 345 { 346 return pcpu_running(pcpu_devices + cpu); 347 } 348 349 void smp_yield(void) 350 { 351 if (MACHINE_HAS_DIAG44) 352 asm volatile("diag 0,0,0x44"); 353 } 354 355 void smp_yield_cpu(int cpu) 356 { 357 if (MACHINE_HAS_DIAG9C) 358 asm volatile("diag %0,0,0x9c" 359 : : "d" (pcpu_devices[cpu].address)); 360 else if (MACHINE_HAS_DIAG44) 361 asm volatile("diag 0,0,0x44"); 362 } 363 364 /* 365 * Send cpus emergency shutdown signal. This gives the cpus the 366 * opportunity to complete outstanding interrupts. 367 */ 368 static void smp_emergency_stop(cpumask_t *cpumask) 369 { 370 u64 end; 371 int cpu; 372 373 end = get_tod_clock() + (1000000UL << 12); 374 for_each_cpu(cpu, cpumask) { 375 struct pcpu *pcpu = pcpu_devices + cpu; 376 set_bit(ec_stop_cpu, &pcpu->ec_mask); 377 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL, 378 0, NULL) == SIGP_CC_BUSY && 379 get_tod_clock() < end) 380 cpu_relax(); 381 } 382 while (get_tod_clock() < end) { 383 for_each_cpu(cpu, cpumask) 384 if (pcpu_stopped(pcpu_devices + cpu)) 385 cpumask_clear_cpu(cpu, cpumask); 386 if (cpumask_empty(cpumask)) 387 break; 388 cpu_relax(); 389 } 390 } 391 392 /* 393 * Stop all cpus but the current one. 394 */ 395 void smp_send_stop(void) 396 { 397 cpumask_t cpumask; 398 int cpu; 399 400 /* Disable all interrupts/machine checks */ 401 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); 402 trace_hardirqs_off(); 403 404 debug_set_critical(); 405 cpumask_copy(&cpumask, cpu_online_mask); 406 cpumask_clear_cpu(smp_processor_id(), &cpumask); 407 408 if (oops_in_progress) 409 smp_emergency_stop(&cpumask); 410 411 /* stop all processors */ 412 for_each_cpu(cpu, &cpumask) { 413 struct pcpu *pcpu = pcpu_devices + cpu; 414 pcpu_sigp_retry(pcpu, SIGP_STOP, 0); 415 while (!pcpu_stopped(pcpu)) 416 cpu_relax(); 417 } 418 } 419 420 /* 421 * Stop the current cpu. 422 */ 423 void smp_stop_cpu(void) 424 { 425 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0); 426 for (;;) ; 427 } 428 429 /* 430 * This is the main routine where commands issued by other 431 * cpus are handled. 432 */ 433 static void smp_handle_ext_call(void) 434 { 435 unsigned long bits; 436 437 /* handle bit signal external calls */ 438 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0); 439 if (test_bit(ec_stop_cpu, &bits)) 440 smp_stop_cpu(); 441 if (test_bit(ec_schedule, &bits)) 442 scheduler_ipi(); 443 if (test_bit(ec_call_function_single, &bits)) 444 generic_smp_call_function_single_interrupt(); 445 } 446 447 static void do_ext_call_interrupt(struct ext_code ext_code, 448 unsigned int param32, unsigned long param64) 449 { 450 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS); 451 smp_handle_ext_call(); 452 } 453 454 void arch_send_call_function_ipi_mask(const struct cpumask *mask) 455 { 456 int cpu; 457 458 for_each_cpu(cpu, mask) 459 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); 460 } 461 462 void arch_send_call_function_single_ipi(int cpu) 463 { 464 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); 465 } 466 467 #ifndef CONFIG_64BIT 468 /* 469 * this function sends a 'purge tlb' signal to another CPU. 470 */ 471 static void smp_ptlb_callback(void *info) 472 { 473 __tlb_flush_local(); 474 } 475 476 void smp_ptlb_all(void) 477 { 478 on_each_cpu(smp_ptlb_callback, NULL, 1); 479 } 480 EXPORT_SYMBOL(smp_ptlb_all); 481 #endif /* ! CONFIG_64BIT */ 482 483 /* 484 * this function sends a 'reschedule' IPI to another CPU. 485 * it goes straight through and wastes no time serializing 486 * anything. Worst case is that we lose a reschedule ... 487 */ 488 void smp_send_reschedule(int cpu) 489 { 490 pcpu_ec_call(pcpu_devices + cpu, ec_schedule); 491 } 492 493 /* 494 * parameter area for the set/clear control bit callbacks 495 */ 496 struct ec_creg_mask_parms { 497 unsigned long orval; 498 unsigned long andval; 499 int cr; 500 }; 501 502 /* 503 * callback for setting/clearing control bits 504 */ 505 static void smp_ctl_bit_callback(void *info) 506 { 507 struct ec_creg_mask_parms *pp = info; 508 unsigned long cregs[16]; 509 510 __ctl_store(cregs, 0, 15); 511 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval; 512 __ctl_load(cregs, 0, 15); 513 } 514 515 /* 516 * Set a bit in a control register of all cpus 517 */ 518 void smp_ctl_set_bit(int cr, int bit) 519 { 520 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr }; 521 522 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 523 } 524 EXPORT_SYMBOL(smp_ctl_set_bit); 525 526 /* 527 * Clear a bit in a control register of all cpus 528 */ 529 void smp_ctl_clear_bit(int cr, int bit) 530 { 531 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr }; 532 533 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 534 } 535 EXPORT_SYMBOL(smp_ctl_clear_bit); 536 537 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_CRASH_DUMP) 538 539 static void __init smp_get_save_area(int cpu, u16 address) 540 { 541 void *lc = pcpu_devices[0].lowcore; 542 struct save_area *save_area; 543 544 if (is_kdump_kernel()) 545 return; 546 if (!OLDMEM_BASE && (address == boot_cpu_address || 547 ipl_info.type != IPL_TYPE_FCP_DUMP)) 548 return; 549 save_area = dump_save_area_create(cpu); 550 if (!save_area) 551 panic("could not allocate memory for save area\n"); 552 #ifdef CONFIG_CRASH_DUMP 553 if (address == boot_cpu_address) { 554 /* Copy the registers of the boot cpu. */ 555 copy_oldmem_page(1, (void *) save_area, sizeof(*save_area), 556 SAVE_AREA_BASE - PAGE_SIZE, 0); 557 return; 558 } 559 #endif 560 /* Get the registers of a non-boot cpu. */ 561 __pcpu_sigp_relax(address, SIGP_STOP_AND_STORE_STATUS, 0, NULL); 562 memcpy_real(save_area, lc + SAVE_AREA_BASE, sizeof(*save_area)); 563 } 564 565 int smp_store_status(int cpu) 566 { 567 struct pcpu *pcpu; 568 569 pcpu = pcpu_devices + cpu; 570 if (__pcpu_sigp_relax(pcpu->address, SIGP_STOP_AND_STORE_STATUS, 571 0, NULL) != SIGP_CC_ORDER_CODE_ACCEPTED) 572 return -EIO; 573 return 0; 574 } 575 576 #else /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */ 577 578 static inline void smp_get_save_area(int cpu, u16 address) { } 579 580 #endif /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */ 581 582 void smp_cpu_set_polarization(int cpu, int val) 583 { 584 pcpu_devices[cpu].polarization = val; 585 } 586 587 int smp_cpu_get_polarization(int cpu) 588 { 589 return pcpu_devices[cpu].polarization; 590 } 591 592 static struct sclp_cpu_info *smp_get_cpu_info(void) 593 { 594 static int use_sigp_detection; 595 struct sclp_cpu_info *info; 596 int address; 597 598 info = kzalloc(sizeof(*info), GFP_KERNEL); 599 if (info && (use_sigp_detection || sclp_get_cpu_info(info))) { 600 use_sigp_detection = 1; 601 for (address = 0; address <= MAX_CPU_ADDRESS; address++) { 602 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0, NULL) == 603 SIGP_CC_NOT_OPERATIONAL) 604 continue; 605 info->cpu[info->configured].address = address; 606 info->configured++; 607 } 608 info->combined = info->configured; 609 } 610 return info; 611 } 612 613 static int smp_add_present_cpu(int cpu); 614 615 static int __smp_rescan_cpus(struct sclp_cpu_info *info, int sysfs_add) 616 { 617 struct pcpu *pcpu; 618 cpumask_t avail; 619 int cpu, nr, i; 620 621 nr = 0; 622 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask); 623 cpu = cpumask_first(&avail); 624 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) { 625 if (info->has_cpu_type && info->cpu[i].type != boot_cpu_type) 626 continue; 627 if (pcpu_find_address(cpu_present_mask, info->cpu[i].address)) 628 continue; 629 pcpu = pcpu_devices + cpu; 630 pcpu->address = info->cpu[i].address; 631 pcpu->state = (i >= info->configured) ? 632 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED; 633 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 634 set_cpu_present(cpu, true); 635 if (sysfs_add && smp_add_present_cpu(cpu) != 0) 636 set_cpu_present(cpu, false); 637 else 638 nr++; 639 cpu = cpumask_next(cpu, &avail); 640 } 641 return nr; 642 } 643 644 static void __init smp_detect_cpus(void) 645 { 646 unsigned int cpu, c_cpus, s_cpus; 647 struct sclp_cpu_info *info; 648 649 info = smp_get_cpu_info(); 650 if (!info) 651 panic("smp_detect_cpus failed to allocate memory\n"); 652 if (info->has_cpu_type) { 653 for (cpu = 0; cpu < info->combined; cpu++) { 654 if (info->cpu[cpu].address != boot_cpu_address) 655 continue; 656 /* The boot cpu dictates the cpu type. */ 657 boot_cpu_type = info->cpu[cpu].type; 658 break; 659 } 660 } 661 c_cpus = s_cpus = 0; 662 for (cpu = 0; cpu < info->combined; cpu++) { 663 if (info->has_cpu_type && info->cpu[cpu].type != boot_cpu_type) 664 continue; 665 if (cpu < info->configured) { 666 smp_get_save_area(c_cpus, info->cpu[cpu].address); 667 c_cpus++; 668 } else 669 s_cpus++; 670 } 671 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus); 672 get_online_cpus(); 673 __smp_rescan_cpus(info, 0); 674 put_online_cpus(); 675 kfree(info); 676 } 677 678 /* 679 * Activate a secondary processor. 680 */ 681 static void smp_start_secondary(void *cpuvoid) 682 { 683 S390_lowcore.last_update_clock = get_tod_clock(); 684 S390_lowcore.restart_stack = (unsigned long) restart_stack; 685 S390_lowcore.restart_fn = (unsigned long) do_restart; 686 S390_lowcore.restart_data = 0; 687 S390_lowcore.restart_source = -1UL; 688 restore_access_regs(S390_lowcore.access_regs_save_area); 689 __ctl_load(S390_lowcore.cregs_save_area, 0, 15); 690 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); 691 cpu_init(); 692 preempt_disable(); 693 init_cpu_timer(); 694 init_cpu_vtimer(); 695 pfault_init(); 696 notify_cpu_starting(smp_processor_id()); 697 set_cpu_online(smp_processor_id(), true); 698 inc_irq_stat(CPU_RST); 699 local_irq_enable(); 700 cpu_startup_entry(CPUHP_ONLINE); 701 } 702 703 /* Upping and downing of CPUs */ 704 int __cpu_up(unsigned int cpu, struct task_struct *tidle) 705 { 706 struct pcpu *pcpu; 707 int rc; 708 709 pcpu = pcpu_devices + cpu; 710 if (pcpu->state != CPU_STATE_CONFIGURED) 711 return -EIO; 712 if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) != 713 SIGP_CC_ORDER_CODE_ACCEPTED) 714 return -EIO; 715 716 rc = pcpu_alloc_lowcore(pcpu, cpu); 717 if (rc) 718 return rc; 719 pcpu_prepare_secondary(pcpu, cpu); 720 pcpu_attach_task(pcpu, tidle); 721 pcpu_start_fn(pcpu, smp_start_secondary, NULL); 722 while (!cpu_online(cpu)) 723 cpu_relax(); 724 return 0; 725 } 726 727 static unsigned int setup_possible_cpus __initdata; 728 729 static int __init _setup_possible_cpus(char *s) 730 { 731 get_option(&s, &setup_possible_cpus); 732 return 0; 733 } 734 early_param("possible_cpus", _setup_possible_cpus); 735 736 #ifdef CONFIG_HOTPLUG_CPU 737 738 int __cpu_disable(void) 739 { 740 unsigned long cregs[16]; 741 742 /* Handle possible pending IPIs */ 743 smp_handle_ext_call(); 744 set_cpu_online(smp_processor_id(), false); 745 /* Disable pseudo page faults on this cpu. */ 746 pfault_fini(); 747 /* Disable interrupt sources via control register. */ 748 __ctl_store(cregs, 0, 15); 749 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */ 750 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */ 751 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */ 752 __ctl_load(cregs, 0, 15); 753 return 0; 754 } 755 756 void __cpu_die(unsigned int cpu) 757 { 758 struct pcpu *pcpu; 759 760 /* Wait until target cpu is down */ 761 pcpu = pcpu_devices + cpu; 762 while (!pcpu_stopped(pcpu)) 763 cpu_relax(); 764 pcpu_free_lowcore(pcpu); 765 atomic_dec(&init_mm.context.attach_count); 766 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm)); 767 if (MACHINE_HAS_TLB_LC) 768 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask); 769 } 770 771 void __noreturn cpu_die(void) 772 { 773 idle_task_exit(); 774 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0); 775 for (;;) ; 776 } 777 778 #endif /* CONFIG_HOTPLUG_CPU */ 779 780 void __init smp_fill_possible_mask(void) 781 { 782 unsigned int possible, sclp, cpu; 783 784 sclp = sclp_get_max_cpu() ?: nr_cpu_ids; 785 possible = setup_possible_cpus ?: nr_cpu_ids; 786 possible = min(possible, sclp); 787 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++) 788 set_cpu_possible(cpu, true); 789 } 790 791 void __init smp_prepare_cpus(unsigned int max_cpus) 792 { 793 /* request the 0x1201 emergency signal external interrupt */ 794 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt)) 795 panic("Couldn't request external interrupt 0x1201"); 796 /* request the 0x1202 external call external interrupt */ 797 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt)) 798 panic("Couldn't request external interrupt 0x1202"); 799 smp_detect_cpus(); 800 } 801 802 void __init smp_prepare_boot_cpu(void) 803 { 804 struct pcpu *pcpu = pcpu_devices; 805 806 boot_cpu_address = stap(); 807 pcpu->state = CPU_STATE_CONFIGURED; 808 pcpu->address = boot_cpu_address; 809 pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix(); 810 pcpu->async_stack = S390_lowcore.async_stack - ASYNC_SIZE 811 + STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); 812 pcpu->panic_stack = S390_lowcore.panic_stack - PAGE_SIZE 813 + STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); 814 S390_lowcore.percpu_offset = __per_cpu_offset[0]; 815 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN); 816 set_cpu_present(0, true); 817 set_cpu_online(0, true); 818 } 819 820 void __init smp_cpus_done(unsigned int max_cpus) 821 { 822 } 823 824 void __init smp_setup_processor_id(void) 825 { 826 S390_lowcore.cpu_nr = 0; 827 } 828 829 /* 830 * the frequency of the profiling timer can be changed 831 * by writing a multiplier value into /proc/profile. 832 * 833 * usually you want to run this on all CPUs ;) 834 */ 835 int setup_profiling_timer(unsigned int multiplier) 836 { 837 return 0; 838 } 839 840 #ifdef CONFIG_HOTPLUG_CPU 841 static ssize_t cpu_configure_show(struct device *dev, 842 struct device_attribute *attr, char *buf) 843 { 844 ssize_t count; 845 846 mutex_lock(&smp_cpu_state_mutex); 847 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state); 848 mutex_unlock(&smp_cpu_state_mutex); 849 return count; 850 } 851 852 static ssize_t cpu_configure_store(struct device *dev, 853 struct device_attribute *attr, 854 const char *buf, size_t count) 855 { 856 struct pcpu *pcpu; 857 int cpu, val, rc; 858 char delim; 859 860 if (sscanf(buf, "%d %c", &val, &delim) != 1) 861 return -EINVAL; 862 if (val != 0 && val != 1) 863 return -EINVAL; 864 get_online_cpus(); 865 mutex_lock(&smp_cpu_state_mutex); 866 rc = -EBUSY; 867 /* disallow configuration changes of online cpus and cpu 0 */ 868 cpu = dev->id; 869 if (cpu_online(cpu) || cpu == 0) 870 goto out; 871 pcpu = pcpu_devices + cpu; 872 rc = 0; 873 switch (val) { 874 case 0: 875 if (pcpu->state != CPU_STATE_CONFIGURED) 876 break; 877 rc = sclp_cpu_deconfigure(pcpu->address); 878 if (rc) 879 break; 880 pcpu->state = CPU_STATE_STANDBY; 881 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 882 topology_expect_change(); 883 break; 884 case 1: 885 if (pcpu->state != CPU_STATE_STANDBY) 886 break; 887 rc = sclp_cpu_configure(pcpu->address); 888 if (rc) 889 break; 890 pcpu->state = CPU_STATE_CONFIGURED; 891 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 892 topology_expect_change(); 893 break; 894 default: 895 break; 896 } 897 out: 898 mutex_unlock(&smp_cpu_state_mutex); 899 put_online_cpus(); 900 return rc ? rc : count; 901 } 902 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store); 903 #endif /* CONFIG_HOTPLUG_CPU */ 904 905 static ssize_t show_cpu_address(struct device *dev, 906 struct device_attribute *attr, char *buf) 907 { 908 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address); 909 } 910 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL); 911 912 static struct attribute *cpu_common_attrs[] = { 913 #ifdef CONFIG_HOTPLUG_CPU 914 &dev_attr_configure.attr, 915 #endif 916 &dev_attr_address.attr, 917 NULL, 918 }; 919 920 static struct attribute_group cpu_common_attr_group = { 921 .attrs = cpu_common_attrs, 922 }; 923 924 static ssize_t show_idle_count(struct device *dev, 925 struct device_attribute *attr, char *buf) 926 { 927 struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id); 928 unsigned long long idle_count; 929 unsigned int sequence; 930 931 do { 932 sequence = ACCESS_ONCE(idle->sequence); 933 idle_count = ACCESS_ONCE(idle->idle_count); 934 if (ACCESS_ONCE(idle->clock_idle_enter)) 935 idle_count++; 936 } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence)); 937 return sprintf(buf, "%llu\n", idle_count); 938 } 939 static DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL); 940 941 static ssize_t show_idle_time(struct device *dev, 942 struct device_attribute *attr, char *buf) 943 { 944 struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id); 945 unsigned long long now, idle_time, idle_enter, idle_exit; 946 unsigned int sequence; 947 948 do { 949 now = get_tod_clock(); 950 sequence = ACCESS_ONCE(idle->sequence); 951 idle_time = ACCESS_ONCE(idle->idle_time); 952 idle_enter = ACCESS_ONCE(idle->clock_idle_enter); 953 idle_exit = ACCESS_ONCE(idle->clock_idle_exit); 954 } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence)); 955 idle_time += idle_enter ? ((idle_exit ? : now) - idle_enter) : 0; 956 return sprintf(buf, "%llu\n", idle_time >> 12); 957 } 958 static DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL); 959 960 static struct attribute *cpu_online_attrs[] = { 961 &dev_attr_idle_count.attr, 962 &dev_attr_idle_time_us.attr, 963 NULL, 964 }; 965 966 static struct attribute_group cpu_online_attr_group = { 967 .attrs = cpu_online_attrs, 968 }; 969 970 static int smp_cpu_notify(struct notifier_block *self, unsigned long action, 971 void *hcpu) 972 { 973 unsigned int cpu = (unsigned int)(long)hcpu; 974 struct cpu *c = pcpu_devices[cpu].cpu; 975 struct device *s = &c->dev; 976 int err = 0; 977 978 switch (action & ~CPU_TASKS_FROZEN) { 979 case CPU_ONLINE: 980 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 981 break; 982 case CPU_DEAD: 983 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 984 break; 985 } 986 return notifier_from_errno(err); 987 } 988 989 static int smp_add_present_cpu(int cpu) 990 { 991 struct device *s; 992 struct cpu *c; 993 int rc; 994 995 c = kzalloc(sizeof(*c), GFP_KERNEL); 996 if (!c) 997 return -ENOMEM; 998 pcpu_devices[cpu].cpu = c; 999 s = &c->dev; 1000 c->hotpluggable = 1; 1001 rc = register_cpu(c, cpu); 1002 if (rc) 1003 goto out; 1004 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group); 1005 if (rc) 1006 goto out_cpu; 1007 if (cpu_online(cpu)) { 1008 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 1009 if (rc) 1010 goto out_online; 1011 } 1012 rc = topology_cpu_init(c); 1013 if (rc) 1014 goto out_topology; 1015 return 0; 1016 1017 out_topology: 1018 if (cpu_online(cpu)) 1019 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 1020 out_online: 1021 sysfs_remove_group(&s->kobj, &cpu_common_attr_group); 1022 out_cpu: 1023 #ifdef CONFIG_HOTPLUG_CPU 1024 unregister_cpu(c); 1025 #endif 1026 out: 1027 return rc; 1028 } 1029 1030 #ifdef CONFIG_HOTPLUG_CPU 1031 1032 int __ref smp_rescan_cpus(void) 1033 { 1034 struct sclp_cpu_info *info; 1035 int nr; 1036 1037 info = smp_get_cpu_info(); 1038 if (!info) 1039 return -ENOMEM; 1040 get_online_cpus(); 1041 mutex_lock(&smp_cpu_state_mutex); 1042 nr = __smp_rescan_cpus(info, 1); 1043 mutex_unlock(&smp_cpu_state_mutex); 1044 put_online_cpus(); 1045 kfree(info); 1046 if (nr) 1047 topology_schedule_update(); 1048 return 0; 1049 } 1050 1051 static ssize_t __ref rescan_store(struct device *dev, 1052 struct device_attribute *attr, 1053 const char *buf, 1054 size_t count) 1055 { 1056 int rc; 1057 1058 rc = smp_rescan_cpus(); 1059 return rc ? rc : count; 1060 } 1061 static DEVICE_ATTR(rescan, 0200, NULL, rescan_store); 1062 #endif /* CONFIG_HOTPLUG_CPU */ 1063 1064 static int __init s390_smp_init(void) 1065 { 1066 int cpu, rc = 0; 1067 1068 #ifdef CONFIG_HOTPLUG_CPU 1069 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan); 1070 if (rc) 1071 return rc; 1072 #endif 1073 cpu_notifier_register_begin(); 1074 for_each_present_cpu(cpu) { 1075 rc = smp_add_present_cpu(cpu); 1076 if (rc) 1077 goto out; 1078 } 1079 1080 __hotcpu_notifier(smp_cpu_notify, 0); 1081 1082 out: 1083 cpu_notifier_register_done(); 1084 return rc; 1085 } 1086 subsys_initcall(s390_smp_init); 1087