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 atomic_inc(&init_mm.context.attach_count); 240 lc->cpu_nr = cpu; 241 lc->percpu_offset = __per_cpu_offset[cpu]; 242 lc->kernel_asce = S390_lowcore.kernel_asce; 243 lc->machine_flags = S390_lowcore.machine_flags; 244 lc->ftrace_func = S390_lowcore.ftrace_func; 245 lc->user_timer = lc->system_timer = lc->steal_timer = 0; 246 __ctl_store(lc->cregs_save_area, 0, 15); 247 save_access_regs((unsigned int *) lc->access_regs_save_area); 248 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list, 249 MAX_FACILITY_BIT/8); 250 } 251 252 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk) 253 { 254 struct _lowcore *lc = pcpu->lowcore; 255 struct thread_info *ti = task_thread_info(tsk); 256 257 lc->kernel_stack = (unsigned long) task_stack_page(tsk) 258 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); 259 lc->thread_info = (unsigned long) task_thread_info(tsk); 260 lc->current_task = (unsigned long) tsk; 261 lc->user_timer = ti->user_timer; 262 lc->system_timer = ti->system_timer; 263 lc->steal_timer = 0; 264 } 265 266 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data) 267 { 268 struct _lowcore *lc = pcpu->lowcore; 269 270 lc->restart_stack = lc->kernel_stack; 271 lc->restart_fn = (unsigned long) func; 272 lc->restart_data = (unsigned long) data; 273 lc->restart_source = -1UL; 274 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0); 275 } 276 277 /* 278 * Call function via PSW restart on pcpu and stop the current cpu. 279 */ 280 static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *), 281 void *data, unsigned long stack) 282 { 283 struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices]; 284 unsigned long source_cpu = stap(); 285 286 __load_psw_mask(PSW_KERNEL_BITS); 287 if (pcpu->address == source_cpu) 288 func(data); /* should not return */ 289 /* Stop target cpu (if func returns this stops the current cpu). */ 290 pcpu_sigp_retry(pcpu, SIGP_STOP, 0); 291 /* Restart func on the target cpu and stop the current cpu. */ 292 mem_assign_absolute(lc->restart_stack, stack); 293 mem_assign_absolute(lc->restart_fn, (unsigned long) func); 294 mem_assign_absolute(lc->restart_data, (unsigned long) data); 295 mem_assign_absolute(lc->restart_source, source_cpu); 296 asm volatile( 297 "0: sigp 0,%0,%2 # sigp restart to target cpu\n" 298 " brc 2,0b # busy, try again\n" 299 "1: sigp 0,%1,%3 # sigp stop to current cpu\n" 300 " brc 2,1b # busy, try again\n" 301 : : "d" (pcpu->address), "d" (source_cpu), 302 "K" (SIGP_RESTART), "K" (SIGP_STOP) 303 : "0", "1", "cc"); 304 for (;;) ; 305 } 306 307 /* 308 * Call function on an online CPU. 309 */ 310 void smp_call_online_cpu(void (*func)(void *), void *data) 311 { 312 struct pcpu *pcpu; 313 314 /* Use the current cpu if it is online. */ 315 pcpu = pcpu_find_address(cpu_online_mask, stap()); 316 if (!pcpu) 317 /* Use the first online cpu. */ 318 pcpu = pcpu_devices + cpumask_first(cpu_online_mask); 319 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack); 320 } 321 322 /* 323 * Call function on the ipl CPU. 324 */ 325 void smp_call_ipl_cpu(void (*func)(void *), void *data) 326 { 327 pcpu_delegate(&pcpu_devices[0], func, data, 328 pcpu_devices->panic_stack + PAGE_SIZE); 329 } 330 331 int smp_find_processor_id(u16 address) 332 { 333 int cpu; 334 335 for_each_present_cpu(cpu) 336 if (pcpu_devices[cpu].address == address) 337 return cpu; 338 return -1; 339 } 340 341 int smp_vcpu_scheduled(int cpu) 342 { 343 return pcpu_running(pcpu_devices + cpu); 344 } 345 346 void smp_yield(void) 347 { 348 if (MACHINE_HAS_DIAG44) 349 asm volatile("diag 0,0,0x44"); 350 } 351 352 void smp_yield_cpu(int cpu) 353 { 354 if (MACHINE_HAS_DIAG9C) 355 asm volatile("diag %0,0,0x9c" 356 : : "d" (pcpu_devices[cpu].address)); 357 else if (MACHINE_HAS_DIAG44) 358 asm volatile("diag 0,0,0x44"); 359 } 360 361 /* 362 * Send cpus emergency shutdown signal. This gives the cpus the 363 * opportunity to complete outstanding interrupts. 364 */ 365 static void smp_emergency_stop(cpumask_t *cpumask) 366 { 367 u64 end; 368 int cpu; 369 370 end = get_tod_clock() + (1000000UL << 12); 371 for_each_cpu(cpu, cpumask) { 372 struct pcpu *pcpu = pcpu_devices + cpu; 373 set_bit(ec_stop_cpu, &pcpu->ec_mask); 374 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL, 375 0, NULL) == SIGP_CC_BUSY && 376 get_tod_clock() < end) 377 cpu_relax(); 378 } 379 while (get_tod_clock() < end) { 380 for_each_cpu(cpu, cpumask) 381 if (pcpu_stopped(pcpu_devices + cpu)) 382 cpumask_clear_cpu(cpu, cpumask); 383 if (cpumask_empty(cpumask)) 384 break; 385 cpu_relax(); 386 } 387 } 388 389 /* 390 * Stop all cpus but the current one. 391 */ 392 void smp_send_stop(void) 393 { 394 cpumask_t cpumask; 395 int cpu; 396 397 /* Disable all interrupts/machine checks */ 398 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); 399 trace_hardirqs_off(); 400 401 debug_set_critical(); 402 cpumask_copy(&cpumask, cpu_online_mask); 403 cpumask_clear_cpu(smp_processor_id(), &cpumask); 404 405 if (oops_in_progress) 406 smp_emergency_stop(&cpumask); 407 408 /* stop all processors */ 409 for_each_cpu(cpu, &cpumask) { 410 struct pcpu *pcpu = pcpu_devices + cpu; 411 pcpu_sigp_retry(pcpu, SIGP_STOP, 0); 412 while (!pcpu_stopped(pcpu)) 413 cpu_relax(); 414 } 415 } 416 417 /* 418 * Stop the current cpu. 419 */ 420 void smp_stop_cpu(void) 421 { 422 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0); 423 for (;;) ; 424 } 425 426 /* 427 * This is the main routine where commands issued by other 428 * cpus are handled. 429 */ 430 static void smp_handle_ext_call(void) 431 { 432 unsigned long bits; 433 434 /* handle bit signal external calls */ 435 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0); 436 if (test_bit(ec_stop_cpu, &bits)) 437 smp_stop_cpu(); 438 if (test_bit(ec_schedule, &bits)) 439 scheduler_ipi(); 440 if (test_bit(ec_call_function_single, &bits)) 441 generic_smp_call_function_single_interrupt(); 442 } 443 444 static void do_ext_call_interrupt(struct ext_code ext_code, 445 unsigned int param32, unsigned long param64) 446 { 447 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS); 448 smp_handle_ext_call(); 449 } 450 451 void arch_send_call_function_ipi_mask(const struct cpumask *mask) 452 { 453 int cpu; 454 455 for_each_cpu(cpu, mask) 456 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); 457 } 458 459 void arch_send_call_function_single_ipi(int cpu) 460 { 461 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); 462 } 463 464 #ifndef CONFIG_64BIT 465 /* 466 * this function sends a 'purge tlb' signal to another CPU. 467 */ 468 static void smp_ptlb_callback(void *info) 469 { 470 __tlb_flush_local(); 471 } 472 473 void smp_ptlb_all(void) 474 { 475 on_each_cpu(smp_ptlb_callback, NULL, 1); 476 } 477 EXPORT_SYMBOL(smp_ptlb_all); 478 #endif /* ! CONFIG_64BIT */ 479 480 /* 481 * this function sends a 'reschedule' IPI to another CPU. 482 * it goes straight through and wastes no time serializing 483 * anything. Worst case is that we lose a reschedule ... 484 */ 485 void smp_send_reschedule(int cpu) 486 { 487 pcpu_ec_call(pcpu_devices + cpu, ec_schedule); 488 } 489 490 /* 491 * parameter area for the set/clear control bit callbacks 492 */ 493 struct ec_creg_mask_parms { 494 unsigned long orval; 495 unsigned long andval; 496 int cr; 497 }; 498 499 /* 500 * callback for setting/clearing control bits 501 */ 502 static void smp_ctl_bit_callback(void *info) 503 { 504 struct ec_creg_mask_parms *pp = info; 505 unsigned long cregs[16]; 506 507 __ctl_store(cregs, 0, 15); 508 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval; 509 __ctl_load(cregs, 0, 15); 510 } 511 512 /* 513 * Set a bit in a control register of all cpus 514 */ 515 void smp_ctl_set_bit(int cr, int bit) 516 { 517 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr }; 518 519 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 520 } 521 EXPORT_SYMBOL(smp_ctl_set_bit); 522 523 /* 524 * Clear a bit in a control register of all cpus 525 */ 526 void smp_ctl_clear_bit(int cr, int bit) 527 { 528 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr }; 529 530 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 531 } 532 EXPORT_SYMBOL(smp_ctl_clear_bit); 533 534 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_CRASH_DUMP) 535 536 static void __init smp_get_save_area(int cpu, u16 address) 537 { 538 void *lc = pcpu_devices[0].lowcore; 539 struct save_area *save_area; 540 541 if (is_kdump_kernel()) 542 return; 543 if (!OLDMEM_BASE && (address == boot_cpu_address || 544 ipl_info.type != IPL_TYPE_FCP_DUMP)) 545 return; 546 save_area = dump_save_area_create(cpu); 547 if (!save_area) 548 panic("could not allocate memory for save area\n"); 549 #ifdef CONFIG_CRASH_DUMP 550 if (address == boot_cpu_address) { 551 /* Copy the registers of the boot cpu. */ 552 copy_oldmem_page(1, (void *) save_area, sizeof(*save_area), 553 SAVE_AREA_BASE - PAGE_SIZE, 0); 554 return; 555 } 556 #endif 557 /* Get the registers of a non-boot cpu. */ 558 __pcpu_sigp_relax(address, SIGP_STOP_AND_STORE_STATUS, 0, NULL); 559 memcpy_real(save_area, lc + SAVE_AREA_BASE, sizeof(*save_area)); 560 } 561 562 int smp_store_status(int cpu) 563 { 564 struct pcpu *pcpu; 565 566 pcpu = pcpu_devices + cpu; 567 if (__pcpu_sigp_relax(pcpu->address, SIGP_STOP_AND_STORE_STATUS, 568 0, NULL) != SIGP_CC_ORDER_CODE_ACCEPTED) 569 return -EIO; 570 return 0; 571 } 572 573 #else /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */ 574 575 static inline void smp_get_save_area(int cpu, u16 address) { } 576 577 #endif /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */ 578 579 void smp_cpu_set_polarization(int cpu, int val) 580 { 581 pcpu_devices[cpu].polarization = val; 582 } 583 584 int smp_cpu_get_polarization(int cpu) 585 { 586 return pcpu_devices[cpu].polarization; 587 } 588 589 static struct sclp_cpu_info *smp_get_cpu_info(void) 590 { 591 static int use_sigp_detection; 592 struct sclp_cpu_info *info; 593 int address; 594 595 info = kzalloc(sizeof(*info), GFP_KERNEL); 596 if (info && (use_sigp_detection || sclp_get_cpu_info(info))) { 597 use_sigp_detection = 1; 598 for (address = 0; address <= MAX_CPU_ADDRESS; address++) { 599 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0, NULL) == 600 SIGP_CC_NOT_OPERATIONAL) 601 continue; 602 info->cpu[info->configured].address = address; 603 info->configured++; 604 } 605 info->combined = info->configured; 606 } 607 return info; 608 } 609 610 static int smp_add_present_cpu(int cpu); 611 612 static int __smp_rescan_cpus(struct sclp_cpu_info *info, int sysfs_add) 613 { 614 struct pcpu *pcpu; 615 cpumask_t avail; 616 int cpu, nr, i; 617 618 nr = 0; 619 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask); 620 cpu = cpumask_first(&avail); 621 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) { 622 if (info->has_cpu_type && info->cpu[i].type != boot_cpu_type) 623 continue; 624 if (pcpu_find_address(cpu_present_mask, info->cpu[i].address)) 625 continue; 626 pcpu = pcpu_devices + cpu; 627 pcpu->address = info->cpu[i].address; 628 pcpu->state = (i >= info->configured) ? 629 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED; 630 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 631 set_cpu_present(cpu, true); 632 if (sysfs_add && smp_add_present_cpu(cpu) != 0) 633 set_cpu_present(cpu, false); 634 else 635 nr++; 636 cpu = cpumask_next(cpu, &avail); 637 } 638 return nr; 639 } 640 641 static void __init smp_detect_cpus(void) 642 { 643 unsigned int cpu, c_cpus, s_cpus; 644 struct sclp_cpu_info *info; 645 646 info = smp_get_cpu_info(); 647 if (!info) 648 panic("smp_detect_cpus failed to allocate memory\n"); 649 if (info->has_cpu_type) { 650 for (cpu = 0; cpu < info->combined; cpu++) { 651 if (info->cpu[cpu].address != boot_cpu_address) 652 continue; 653 /* The boot cpu dictates the cpu type. */ 654 boot_cpu_type = info->cpu[cpu].type; 655 break; 656 } 657 } 658 c_cpus = s_cpus = 0; 659 for (cpu = 0; cpu < info->combined; cpu++) { 660 if (info->has_cpu_type && info->cpu[cpu].type != boot_cpu_type) 661 continue; 662 if (cpu < info->configured) { 663 smp_get_save_area(c_cpus, info->cpu[cpu].address); 664 c_cpus++; 665 } else 666 s_cpus++; 667 } 668 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus); 669 get_online_cpus(); 670 __smp_rescan_cpus(info, 0); 671 put_online_cpus(); 672 kfree(info); 673 } 674 675 /* 676 * Activate a secondary processor. 677 */ 678 static void smp_start_secondary(void *cpuvoid) 679 { 680 S390_lowcore.last_update_clock = get_tod_clock(); 681 S390_lowcore.restart_stack = (unsigned long) restart_stack; 682 S390_lowcore.restart_fn = (unsigned long) do_restart; 683 S390_lowcore.restart_data = 0; 684 S390_lowcore.restart_source = -1UL; 685 restore_access_regs(S390_lowcore.access_regs_save_area); 686 __ctl_load(S390_lowcore.cregs_save_area, 0, 15); 687 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); 688 cpu_init(); 689 preempt_disable(); 690 init_cpu_timer(); 691 init_cpu_vtimer(); 692 pfault_init(); 693 notify_cpu_starting(smp_processor_id()); 694 set_cpu_online(smp_processor_id(), true); 695 inc_irq_stat(CPU_RST); 696 local_irq_enable(); 697 cpu_startup_entry(CPUHP_ONLINE); 698 } 699 700 /* Upping and downing of CPUs */ 701 int __cpu_up(unsigned int cpu, struct task_struct *tidle) 702 { 703 struct pcpu *pcpu; 704 int rc; 705 706 pcpu = pcpu_devices + cpu; 707 if (pcpu->state != CPU_STATE_CONFIGURED) 708 return -EIO; 709 if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) != 710 SIGP_CC_ORDER_CODE_ACCEPTED) 711 return -EIO; 712 713 rc = pcpu_alloc_lowcore(pcpu, cpu); 714 if (rc) 715 return rc; 716 pcpu_prepare_secondary(pcpu, cpu); 717 pcpu_attach_task(pcpu, tidle); 718 pcpu_start_fn(pcpu, smp_start_secondary, NULL); 719 while (!cpu_online(cpu)) 720 cpu_relax(); 721 return 0; 722 } 723 724 static unsigned int setup_possible_cpus __initdata; 725 726 static int __init _setup_possible_cpus(char *s) 727 { 728 get_option(&s, &setup_possible_cpus); 729 return 0; 730 } 731 early_param("possible_cpus", _setup_possible_cpus); 732 733 #ifdef CONFIG_HOTPLUG_CPU 734 735 int __cpu_disable(void) 736 { 737 unsigned long cregs[16]; 738 739 /* Handle possible pending IPIs */ 740 smp_handle_ext_call(); 741 set_cpu_online(smp_processor_id(), false); 742 /* Disable pseudo page faults on this cpu. */ 743 pfault_fini(); 744 /* Disable interrupt sources via control register. */ 745 __ctl_store(cregs, 0, 15); 746 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */ 747 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */ 748 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */ 749 __ctl_load(cregs, 0, 15); 750 return 0; 751 } 752 753 void __cpu_die(unsigned int cpu) 754 { 755 struct pcpu *pcpu; 756 757 /* Wait until target cpu is down */ 758 pcpu = pcpu_devices + cpu; 759 while (!pcpu_stopped(pcpu)) 760 cpu_relax(); 761 pcpu_free_lowcore(pcpu); 762 atomic_dec(&init_mm.context.attach_count); 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, cpu; 777 778 possible = setup_possible_cpus; 779 if (!possible) 780 possible = MACHINE_IS_VM ? 64 : nr_cpu_ids; 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_interrupt(0x1201, do_ext_call_interrupt) != 0) 789 panic("Couldn't request external interrupt 0x1201"); 790 /* request the 0x1202 external call external interrupt */ 791 if (register_external_interrupt(0x1202, do_ext_call_interrupt) != 0) 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 } 822 823 /* 824 * the frequency of the profiling timer can be changed 825 * by writing a multiplier value into /proc/profile. 826 * 827 * usually you want to run this on all CPUs ;) 828 */ 829 int setup_profiling_timer(unsigned int multiplier) 830 { 831 return 0; 832 } 833 834 #ifdef CONFIG_HOTPLUG_CPU 835 static ssize_t cpu_configure_show(struct device *dev, 836 struct device_attribute *attr, char *buf) 837 { 838 ssize_t count; 839 840 mutex_lock(&smp_cpu_state_mutex); 841 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state); 842 mutex_unlock(&smp_cpu_state_mutex); 843 return count; 844 } 845 846 static ssize_t cpu_configure_store(struct device *dev, 847 struct device_attribute *attr, 848 const char *buf, size_t count) 849 { 850 struct pcpu *pcpu; 851 int cpu, val, rc; 852 char delim; 853 854 if (sscanf(buf, "%d %c", &val, &delim) != 1) 855 return -EINVAL; 856 if (val != 0 && val != 1) 857 return -EINVAL; 858 get_online_cpus(); 859 mutex_lock(&smp_cpu_state_mutex); 860 rc = -EBUSY; 861 /* disallow configuration changes of online cpus and cpu 0 */ 862 cpu = dev->id; 863 if (cpu_online(cpu) || cpu == 0) 864 goto out; 865 pcpu = pcpu_devices + cpu; 866 rc = 0; 867 switch (val) { 868 case 0: 869 if (pcpu->state != CPU_STATE_CONFIGURED) 870 break; 871 rc = sclp_cpu_deconfigure(pcpu->address); 872 if (rc) 873 break; 874 pcpu->state = CPU_STATE_STANDBY; 875 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 876 topology_expect_change(); 877 break; 878 case 1: 879 if (pcpu->state != CPU_STATE_STANDBY) 880 break; 881 rc = sclp_cpu_configure(pcpu->address); 882 if (rc) 883 break; 884 pcpu->state = CPU_STATE_CONFIGURED; 885 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 886 topology_expect_change(); 887 break; 888 default: 889 break; 890 } 891 out: 892 mutex_unlock(&smp_cpu_state_mutex); 893 put_online_cpus(); 894 return rc ? rc : count; 895 } 896 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store); 897 #endif /* CONFIG_HOTPLUG_CPU */ 898 899 static ssize_t show_cpu_address(struct device *dev, 900 struct device_attribute *attr, char *buf) 901 { 902 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address); 903 } 904 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL); 905 906 static struct attribute *cpu_common_attrs[] = { 907 #ifdef CONFIG_HOTPLUG_CPU 908 &dev_attr_configure.attr, 909 #endif 910 &dev_attr_address.attr, 911 NULL, 912 }; 913 914 static struct attribute_group cpu_common_attr_group = { 915 .attrs = cpu_common_attrs, 916 }; 917 918 static ssize_t show_idle_count(struct device *dev, 919 struct device_attribute *attr, char *buf) 920 { 921 struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id); 922 unsigned long long idle_count; 923 unsigned int sequence; 924 925 do { 926 sequence = ACCESS_ONCE(idle->sequence); 927 idle_count = ACCESS_ONCE(idle->idle_count); 928 if (ACCESS_ONCE(idle->clock_idle_enter)) 929 idle_count++; 930 } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence)); 931 return sprintf(buf, "%llu\n", idle_count); 932 } 933 static DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL); 934 935 static ssize_t show_idle_time(struct device *dev, 936 struct device_attribute *attr, char *buf) 937 { 938 struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id); 939 unsigned long long now, idle_time, idle_enter, idle_exit; 940 unsigned int sequence; 941 942 do { 943 now = get_tod_clock(); 944 sequence = ACCESS_ONCE(idle->sequence); 945 idle_time = ACCESS_ONCE(idle->idle_time); 946 idle_enter = ACCESS_ONCE(idle->clock_idle_enter); 947 idle_exit = ACCESS_ONCE(idle->clock_idle_exit); 948 } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence)); 949 idle_time += idle_enter ? ((idle_exit ? : now) - idle_enter) : 0; 950 return sprintf(buf, "%llu\n", idle_time >> 12); 951 } 952 static DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL); 953 954 static struct attribute *cpu_online_attrs[] = { 955 &dev_attr_idle_count.attr, 956 &dev_attr_idle_time_us.attr, 957 NULL, 958 }; 959 960 static struct attribute_group cpu_online_attr_group = { 961 .attrs = cpu_online_attrs, 962 }; 963 964 static int smp_cpu_notify(struct notifier_block *self, unsigned long action, 965 void *hcpu) 966 { 967 unsigned int cpu = (unsigned int)(long)hcpu; 968 struct cpu *c = pcpu_devices[cpu].cpu; 969 struct device *s = &c->dev; 970 int err = 0; 971 972 switch (action & ~CPU_TASKS_FROZEN) { 973 case CPU_ONLINE: 974 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 975 break; 976 case CPU_DEAD: 977 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 978 break; 979 } 980 return notifier_from_errno(err); 981 } 982 983 static int smp_add_present_cpu(int cpu) 984 { 985 struct device *s; 986 struct cpu *c; 987 int rc; 988 989 c = kzalloc(sizeof(*c), GFP_KERNEL); 990 if (!c) 991 return -ENOMEM; 992 pcpu_devices[cpu].cpu = c; 993 s = &c->dev; 994 c->hotpluggable = 1; 995 rc = register_cpu(c, cpu); 996 if (rc) 997 goto out; 998 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group); 999 if (rc) 1000 goto out_cpu; 1001 if (cpu_online(cpu)) { 1002 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 1003 if (rc) 1004 goto out_online; 1005 } 1006 rc = topology_cpu_init(c); 1007 if (rc) 1008 goto out_topology; 1009 return 0; 1010 1011 out_topology: 1012 if (cpu_online(cpu)) 1013 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 1014 out_online: 1015 sysfs_remove_group(&s->kobj, &cpu_common_attr_group); 1016 out_cpu: 1017 #ifdef CONFIG_HOTPLUG_CPU 1018 unregister_cpu(c); 1019 #endif 1020 out: 1021 return rc; 1022 } 1023 1024 #ifdef CONFIG_HOTPLUG_CPU 1025 1026 int __ref smp_rescan_cpus(void) 1027 { 1028 struct sclp_cpu_info *info; 1029 int nr; 1030 1031 info = smp_get_cpu_info(); 1032 if (!info) 1033 return -ENOMEM; 1034 get_online_cpus(); 1035 mutex_lock(&smp_cpu_state_mutex); 1036 nr = __smp_rescan_cpus(info, 1); 1037 mutex_unlock(&smp_cpu_state_mutex); 1038 put_online_cpus(); 1039 kfree(info); 1040 if (nr) 1041 topology_schedule_update(); 1042 return 0; 1043 } 1044 1045 static ssize_t __ref rescan_store(struct device *dev, 1046 struct device_attribute *attr, 1047 const char *buf, 1048 size_t count) 1049 { 1050 int rc; 1051 1052 rc = smp_rescan_cpus(); 1053 return rc ? rc : count; 1054 } 1055 static DEVICE_ATTR(rescan, 0200, NULL, rescan_store); 1056 #endif /* CONFIG_HOTPLUG_CPU */ 1057 1058 static int __init s390_smp_init(void) 1059 { 1060 int cpu, rc; 1061 1062 hotcpu_notifier(smp_cpu_notify, 0); 1063 #ifdef CONFIG_HOTPLUG_CPU 1064 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan); 1065 if (rc) 1066 return rc; 1067 #endif 1068 for_each_present_cpu(cpu) { 1069 rc = smp_add_present_cpu(cpu); 1070 if (rc) 1071 return rc; 1072 } 1073 return 0; 1074 } 1075 subsys_initcall(s390_smp_init); 1076