1 /* 2 * arch/s390/kernel/smp.c 3 * 4 * Copyright IBM Corp. 1999, 2009 5 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), 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 * We work with logical cpu numbering everywhere we can. The only 14 * functions using the real cpu address (got from STAP) are the sigp 15 * functions. For all other functions we use the identity mapping. 16 * That means that cpu_number_map[i] == i for every cpu. cpu_number_map is 17 * used e.g. to find the idle task belonging to a logical cpu. Every array 18 * in the kernel is sorted by the logical cpu number and not by the physical 19 * one which is causing all the confusion with __cpu_logical_map and 20 * cpu_number_map in other architectures. 21 */ 22 23 #define KMSG_COMPONENT "cpu" 24 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 25 26 #include <linux/workqueue.h> 27 #include <linux/module.h> 28 #include <linux/init.h> 29 #include <linux/mm.h> 30 #include <linux/err.h> 31 #include <linux/spinlock.h> 32 #include <linux/kernel_stat.h> 33 #include <linux/delay.h> 34 #include <linux/cache.h> 35 #include <linux/interrupt.h> 36 #include <linux/irqflags.h> 37 #include <linux/cpu.h> 38 #include <linux/timex.h> 39 #include <linux/bootmem.h> 40 #include <linux/slab.h> 41 #include <linux/crash_dump.h> 42 #include <asm/asm-offsets.h> 43 #include <asm/ipl.h> 44 #include <asm/setup.h> 45 #include <asm/sigp.h> 46 #include <asm/pgalloc.h> 47 #include <asm/irq.h> 48 #include <asm/cpcmd.h> 49 #include <asm/tlbflush.h> 50 #include <asm/timer.h> 51 #include <asm/lowcore.h> 52 #include <asm/sclp.h> 53 #include <asm/cputime.h> 54 #include <asm/vdso.h> 55 #include <asm/cpu.h> 56 #include "entry.h" 57 58 /* logical cpu to cpu address */ 59 unsigned short __cpu_logical_map[NR_CPUS]; 60 61 static struct task_struct *current_set[NR_CPUS]; 62 63 static u8 smp_cpu_type; 64 static int smp_use_sigp_detection; 65 66 enum s390_cpu_state { 67 CPU_STATE_STANDBY, 68 CPU_STATE_CONFIGURED, 69 }; 70 71 DEFINE_MUTEX(smp_cpu_state_mutex); 72 static int smp_cpu_state[NR_CPUS]; 73 74 static DEFINE_PER_CPU(struct cpu, cpu_devices); 75 76 static void smp_ext_bitcall(int, int); 77 78 static int raw_cpu_stopped(int cpu) 79 { 80 u32 status; 81 82 switch (raw_sigp_ps(&status, 0, cpu, sigp_sense)) { 83 case sigp_status_stored: 84 /* Check for stopped and check stop state */ 85 if (status & 0x50) 86 return 1; 87 break; 88 default: 89 break; 90 } 91 return 0; 92 } 93 94 static inline int cpu_stopped(int cpu) 95 { 96 return raw_cpu_stopped(cpu_logical_map(cpu)); 97 } 98 99 /* 100 * Ensure that PSW restart is done on an online CPU 101 */ 102 void smp_restart_with_online_cpu(void) 103 { 104 int cpu; 105 106 for_each_online_cpu(cpu) { 107 if (stap() == __cpu_logical_map[cpu]) { 108 /* We are online: Enable DAT again and return */ 109 __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT); 110 return; 111 } 112 } 113 /* We are not online: Do PSW restart on an online CPU */ 114 while (sigp(cpu, sigp_restart) == sigp_busy) 115 cpu_relax(); 116 /* And stop ourself */ 117 while (raw_sigp(stap(), sigp_stop) == sigp_busy) 118 cpu_relax(); 119 for (;;); 120 } 121 122 void smp_switch_to_ipl_cpu(void (*func)(void *), void *data) 123 { 124 struct _lowcore *lc, *current_lc; 125 struct stack_frame *sf; 126 struct pt_regs *regs; 127 unsigned long sp; 128 129 if (smp_processor_id() == 0) 130 func(data); 131 __load_psw_mask(PSW_DEFAULT_KEY | PSW_MASK_BASE | 132 PSW_MASK_EA | PSW_MASK_BA); 133 /* Disable lowcore protection */ 134 __ctl_clear_bit(0, 28); 135 current_lc = lowcore_ptr[smp_processor_id()]; 136 lc = lowcore_ptr[0]; 137 if (!lc) 138 lc = current_lc; 139 lc->restart_psw.mask = 140 PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA; 141 lc->restart_psw.addr = PSW_ADDR_AMODE | (unsigned long) smp_restart_cpu; 142 if (!cpu_online(0)) 143 smp_switch_to_cpu(func, data, 0, stap(), __cpu_logical_map[0]); 144 while (sigp(0, sigp_stop_and_store_status) == sigp_busy) 145 cpu_relax(); 146 sp = lc->panic_stack; 147 sp -= sizeof(struct pt_regs); 148 regs = (struct pt_regs *) sp; 149 memcpy(®s->gprs, ¤t_lc->gpregs_save_area, sizeof(regs->gprs)); 150 regs->psw = current_lc->psw_save_area; 151 sp -= STACK_FRAME_OVERHEAD; 152 sf = (struct stack_frame *) sp; 153 sf->back_chain = 0; 154 smp_switch_to_cpu(func, data, sp, stap(), __cpu_logical_map[0]); 155 } 156 157 static void smp_stop_cpu(void) 158 { 159 while (sigp(smp_processor_id(), sigp_stop) == sigp_busy) 160 cpu_relax(); 161 } 162 163 void smp_send_stop(void) 164 { 165 cpumask_t cpumask; 166 int cpu; 167 u64 end; 168 169 /* Disable all interrupts/machine checks */ 170 __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT); 171 trace_hardirqs_off(); 172 173 cpumask_copy(&cpumask, cpu_online_mask); 174 cpumask_clear_cpu(smp_processor_id(), &cpumask); 175 176 if (oops_in_progress) { 177 /* 178 * Give the other cpus the opportunity to complete 179 * outstanding interrupts before stopping them. 180 */ 181 end = get_clock() + (1000000UL << 12); 182 for_each_cpu(cpu, &cpumask) { 183 set_bit(ec_stop_cpu, (unsigned long *) 184 &lowcore_ptr[cpu]->ext_call_fast); 185 while (sigp(cpu, sigp_emergency_signal) == sigp_busy && 186 get_clock() < end) 187 cpu_relax(); 188 } 189 while (get_clock() < end) { 190 for_each_cpu(cpu, &cpumask) 191 if (cpu_stopped(cpu)) 192 cpumask_clear_cpu(cpu, &cpumask); 193 if (cpumask_empty(&cpumask)) 194 break; 195 cpu_relax(); 196 } 197 } 198 199 /* stop all processors */ 200 for_each_cpu(cpu, &cpumask) { 201 while (sigp(cpu, sigp_stop) == sigp_busy) 202 cpu_relax(); 203 while (!cpu_stopped(cpu)) 204 cpu_relax(); 205 } 206 } 207 208 /* 209 * This is the main routine where commands issued by other 210 * cpus are handled. 211 */ 212 213 static void do_ext_call_interrupt(unsigned int ext_int_code, 214 unsigned int param32, unsigned long param64) 215 { 216 unsigned long bits; 217 218 if ((ext_int_code & 0xffff) == 0x1202) 219 kstat_cpu(smp_processor_id()).irqs[EXTINT_EXC]++; 220 else 221 kstat_cpu(smp_processor_id()).irqs[EXTINT_EMS]++; 222 /* 223 * handle bit signal external calls 224 */ 225 bits = xchg(&S390_lowcore.ext_call_fast, 0); 226 227 if (test_bit(ec_stop_cpu, &bits)) 228 smp_stop_cpu(); 229 230 if (test_bit(ec_schedule, &bits)) 231 scheduler_ipi(); 232 233 if (test_bit(ec_call_function, &bits)) 234 generic_smp_call_function_interrupt(); 235 236 if (test_bit(ec_call_function_single, &bits)) 237 generic_smp_call_function_single_interrupt(); 238 239 } 240 241 /* 242 * Send an external call sigp to another cpu and return without waiting 243 * for its completion. 244 */ 245 static void smp_ext_bitcall(int cpu, int sig) 246 { 247 int order; 248 249 /* 250 * Set signaling bit in lowcore of target cpu and kick it 251 */ 252 set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast); 253 while (1) { 254 order = smp_vcpu_scheduled(cpu) ? 255 sigp_external_call : sigp_emergency_signal; 256 if (sigp(cpu, order) != sigp_busy) 257 break; 258 udelay(10); 259 } 260 } 261 262 void arch_send_call_function_ipi_mask(const struct cpumask *mask) 263 { 264 int cpu; 265 266 for_each_cpu(cpu, mask) 267 smp_ext_bitcall(cpu, ec_call_function); 268 } 269 270 void arch_send_call_function_single_ipi(int cpu) 271 { 272 smp_ext_bitcall(cpu, ec_call_function_single); 273 } 274 275 #ifndef CONFIG_64BIT 276 /* 277 * this function sends a 'purge tlb' signal to another CPU. 278 */ 279 static void smp_ptlb_callback(void *info) 280 { 281 __tlb_flush_local(); 282 } 283 284 void smp_ptlb_all(void) 285 { 286 on_each_cpu(smp_ptlb_callback, NULL, 1); 287 } 288 EXPORT_SYMBOL(smp_ptlb_all); 289 #endif /* ! CONFIG_64BIT */ 290 291 /* 292 * this function sends a 'reschedule' IPI to another CPU. 293 * it goes straight through and wastes no time serializing 294 * anything. Worst case is that we lose a reschedule ... 295 */ 296 void smp_send_reschedule(int cpu) 297 { 298 smp_ext_bitcall(cpu, ec_schedule); 299 } 300 301 /* 302 * parameter area for the set/clear control bit callbacks 303 */ 304 struct ec_creg_mask_parms { 305 unsigned long orvals[16]; 306 unsigned long andvals[16]; 307 }; 308 309 /* 310 * callback for setting/clearing control bits 311 */ 312 static void smp_ctl_bit_callback(void *info) 313 { 314 struct ec_creg_mask_parms *pp = info; 315 unsigned long cregs[16]; 316 int i; 317 318 __ctl_store(cregs, 0, 15); 319 for (i = 0; i <= 15; i++) 320 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i]; 321 __ctl_load(cregs, 0, 15); 322 } 323 324 /* 325 * Set a bit in a control register of all cpus 326 */ 327 void smp_ctl_set_bit(int cr, int bit) 328 { 329 struct ec_creg_mask_parms parms; 330 331 memset(&parms.orvals, 0, sizeof(parms.orvals)); 332 memset(&parms.andvals, 0xff, sizeof(parms.andvals)); 333 parms.orvals[cr] = 1UL << bit; 334 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 335 } 336 EXPORT_SYMBOL(smp_ctl_set_bit); 337 338 /* 339 * Clear a bit in a control register of all cpus 340 */ 341 void smp_ctl_clear_bit(int cr, int bit) 342 { 343 struct ec_creg_mask_parms parms; 344 345 memset(&parms.orvals, 0, sizeof(parms.orvals)); 346 memset(&parms.andvals, 0xff, sizeof(parms.andvals)); 347 parms.andvals[cr] = ~(1UL << bit); 348 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 349 } 350 EXPORT_SYMBOL(smp_ctl_clear_bit); 351 352 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_CRASH_DUMP) 353 354 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) 355 { 356 if (ipl_info.type != IPL_TYPE_FCP_DUMP && !OLDMEM_BASE) 357 return; 358 if (is_kdump_kernel()) 359 return; 360 if (cpu >= NR_CPUS) { 361 pr_warning("CPU %i exceeds the maximum %i and is excluded from " 362 "the dump\n", cpu, NR_CPUS - 1); 363 return; 364 } 365 zfcpdump_save_areas[cpu] = kmalloc(sizeof(struct save_area), GFP_KERNEL); 366 while (raw_sigp(phy_cpu, sigp_stop_and_store_status) == sigp_busy) 367 cpu_relax(); 368 memcpy_real(zfcpdump_save_areas[cpu], 369 (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE, 370 sizeof(struct save_area)); 371 } 372 373 struct save_area *zfcpdump_save_areas[NR_CPUS + 1]; 374 EXPORT_SYMBOL_GPL(zfcpdump_save_areas); 375 376 #else 377 378 static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { } 379 380 #endif /* CONFIG_ZFCPDUMP */ 381 382 static int cpu_known(int cpu_id) 383 { 384 int cpu; 385 386 for_each_present_cpu(cpu) { 387 if (__cpu_logical_map[cpu] == cpu_id) 388 return 1; 389 } 390 return 0; 391 } 392 393 static int smp_rescan_cpus_sigp(cpumask_t avail) 394 { 395 int cpu_id, logical_cpu; 396 397 logical_cpu = cpumask_first(&avail); 398 if (logical_cpu >= nr_cpu_ids) 399 return 0; 400 for (cpu_id = 0; cpu_id <= MAX_CPU_ADDRESS; cpu_id++) { 401 if (cpu_known(cpu_id)) 402 continue; 403 __cpu_logical_map[logical_cpu] = cpu_id; 404 cpu_set_polarization(logical_cpu, POLARIZATION_UNKNOWN); 405 if (!cpu_stopped(logical_cpu)) 406 continue; 407 set_cpu_present(logical_cpu, true); 408 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED; 409 logical_cpu = cpumask_next(logical_cpu, &avail); 410 if (logical_cpu >= nr_cpu_ids) 411 break; 412 } 413 return 0; 414 } 415 416 static int smp_rescan_cpus_sclp(cpumask_t avail) 417 { 418 struct sclp_cpu_info *info; 419 int cpu_id, logical_cpu, cpu; 420 int rc; 421 422 logical_cpu = cpumask_first(&avail); 423 if (logical_cpu >= nr_cpu_ids) 424 return 0; 425 info = kmalloc(sizeof(*info), GFP_KERNEL); 426 if (!info) 427 return -ENOMEM; 428 rc = sclp_get_cpu_info(info); 429 if (rc) 430 goto out; 431 for (cpu = 0; cpu < info->combined; cpu++) { 432 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type) 433 continue; 434 cpu_id = info->cpu[cpu].address; 435 if (cpu_known(cpu_id)) 436 continue; 437 __cpu_logical_map[logical_cpu] = cpu_id; 438 cpu_set_polarization(logical_cpu, POLARIZATION_UNKNOWN); 439 set_cpu_present(logical_cpu, true); 440 if (cpu >= info->configured) 441 smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY; 442 else 443 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED; 444 logical_cpu = cpumask_next(logical_cpu, &avail); 445 if (logical_cpu >= nr_cpu_ids) 446 break; 447 } 448 out: 449 kfree(info); 450 return rc; 451 } 452 453 static int __smp_rescan_cpus(void) 454 { 455 cpumask_t avail; 456 457 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask); 458 if (smp_use_sigp_detection) 459 return smp_rescan_cpus_sigp(avail); 460 else 461 return smp_rescan_cpus_sclp(avail); 462 } 463 464 static void __init smp_detect_cpus(void) 465 { 466 unsigned int cpu, c_cpus, s_cpus; 467 struct sclp_cpu_info *info; 468 u16 boot_cpu_addr, cpu_addr; 469 470 c_cpus = 1; 471 s_cpus = 0; 472 boot_cpu_addr = __cpu_logical_map[0]; 473 info = kmalloc(sizeof(*info), GFP_KERNEL); 474 if (!info) 475 panic("smp_detect_cpus failed to allocate memory\n"); 476 #ifdef CONFIG_CRASH_DUMP 477 if (OLDMEM_BASE && !is_kdump_kernel()) { 478 struct save_area *save_area; 479 480 save_area = kmalloc(sizeof(*save_area), GFP_KERNEL); 481 if (!save_area) 482 panic("could not allocate memory for save area\n"); 483 copy_oldmem_page(1, (void *) save_area, sizeof(*save_area), 484 0x200, 0); 485 zfcpdump_save_areas[0] = save_area; 486 } 487 #endif 488 /* Use sigp detection algorithm if sclp doesn't work. */ 489 if (sclp_get_cpu_info(info)) { 490 smp_use_sigp_detection = 1; 491 for (cpu = 0; cpu <= MAX_CPU_ADDRESS; cpu++) { 492 if (cpu == boot_cpu_addr) 493 continue; 494 if (!raw_cpu_stopped(cpu)) 495 continue; 496 smp_get_save_area(c_cpus, cpu); 497 c_cpus++; 498 } 499 goto out; 500 } 501 502 if (info->has_cpu_type) { 503 for (cpu = 0; cpu < info->combined; cpu++) { 504 if (info->cpu[cpu].address == boot_cpu_addr) { 505 smp_cpu_type = info->cpu[cpu].type; 506 break; 507 } 508 } 509 } 510 511 for (cpu = 0; cpu < info->combined; cpu++) { 512 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type) 513 continue; 514 cpu_addr = info->cpu[cpu].address; 515 if (cpu_addr == boot_cpu_addr) 516 continue; 517 if (!raw_cpu_stopped(cpu_addr)) { 518 s_cpus++; 519 continue; 520 } 521 smp_get_save_area(c_cpus, cpu_addr); 522 c_cpus++; 523 } 524 out: 525 kfree(info); 526 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus); 527 get_online_cpus(); 528 __smp_rescan_cpus(); 529 put_online_cpus(); 530 } 531 532 /* 533 * Activate a secondary processor. 534 */ 535 int __cpuinit start_secondary(void *cpuvoid) 536 { 537 cpu_init(); 538 preempt_disable(); 539 init_cpu_timer(); 540 init_cpu_vtimer(); 541 pfault_init(); 542 543 notify_cpu_starting(smp_processor_id()); 544 ipi_call_lock(); 545 set_cpu_online(smp_processor_id(), true); 546 ipi_call_unlock(); 547 __ctl_clear_bit(0, 28); /* Disable lowcore protection */ 548 S390_lowcore.restart_psw.mask = 549 PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA; 550 S390_lowcore.restart_psw.addr = 551 PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler; 552 __ctl_set_bit(0, 28); /* Enable lowcore protection */ 553 /* 554 * Wait until the cpu which brought this one up marked it 555 * active before enabling interrupts. 556 */ 557 while (!cpumask_test_cpu(smp_processor_id(), cpu_active_mask)) 558 cpu_relax(); 559 local_irq_enable(); 560 /* cpu_idle will call schedule for us */ 561 cpu_idle(); 562 return 0; 563 } 564 565 struct create_idle { 566 struct work_struct work; 567 struct task_struct *idle; 568 struct completion done; 569 int cpu; 570 }; 571 572 static void __cpuinit smp_fork_idle(struct work_struct *work) 573 { 574 struct create_idle *c_idle; 575 576 c_idle = container_of(work, struct create_idle, work); 577 c_idle->idle = fork_idle(c_idle->cpu); 578 complete(&c_idle->done); 579 } 580 581 static int __cpuinit smp_alloc_lowcore(int cpu) 582 { 583 unsigned long async_stack, panic_stack; 584 struct _lowcore *lowcore; 585 586 lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); 587 if (!lowcore) 588 return -ENOMEM; 589 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER); 590 panic_stack = __get_free_page(GFP_KERNEL); 591 if (!panic_stack || !async_stack) 592 goto out; 593 memcpy(lowcore, &S390_lowcore, 512); 594 memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512); 595 lowcore->async_stack = async_stack + ASYNC_SIZE; 596 lowcore->panic_stack = panic_stack + PAGE_SIZE; 597 lowcore->restart_psw.mask = 598 PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA; 599 lowcore->restart_psw.addr = 600 PSW_ADDR_AMODE | (unsigned long) restart_int_handler; 601 if (user_mode != HOME_SPACE_MODE) 602 lowcore->restart_psw.mask |= PSW_ASC_HOME; 603 #ifndef CONFIG_64BIT 604 if (MACHINE_HAS_IEEE) { 605 unsigned long save_area; 606 607 save_area = get_zeroed_page(GFP_KERNEL); 608 if (!save_area) 609 goto out; 610 lowcore->extended_save_area_addr = (u32) save_area; 611 } 612 #else 613 if (vdso_alloc_per_cpu(cpu, lowcore)) 614 goto out; 615 #endif 616 lowcore_ptr[cpu] = lowcore; 617 return 0; 618 619 out: 620 free_page(panic_stack); 621 free_pages(async_stack, ASYNC_ORDER); 622 free_pages((unsigned long) lowcore, LC_ORDER); 623 return -ENOMEM; 624 } 625 626 static void smp_free_lowcore(int cpu) 627 { 628 struct _lowcore *lowcore; 629 630 lowcore = lowcore_ptr[cpu]; 631 #ifndef CONFIG_64BIT 632 if (MACHINE_HAS_IEEE) 633 free_page((unsigned long) lowcore->extended_save_area_addr); 634 #else 635 vdso_free_per_cpu(cpu, lowcore); 636 #endif 637 free_page(lowcore->panic_stack - PAGE_SIZE); 638 free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER); 639 free_pages((unsigned long) lowcore, LC_ORDER); 640 lowcore_ptr[cpu] = NULL; 641 } 642 643 /* Upping and downing of CPUs */ 644 int __cpuinit __cpu_up(unsigned int cpu) 645 { 646 struct _lowcore *cpu_lowcore; 647 struct create_idle c_idle; 648 struct task_struct *idle; 649 struct stack_frame *sf; 650 u32 lowcore; 651 int ccode; 652 653 if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED) 654 return -EIO; 655 idle = current_set[cpu]; 656 if (!idle) { 657 c_idle.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done); 658 INIT_WORK_ONSTACK(&c_idle.work, smp_fork_idle); 659 c_idle.cpu = cpu; 660 schedule_work(&c_idle.work); 661 wait_for_completion(&c_idle.done); 662 if (IS_ERR(c_idle.idle)) 663 return PTR_ERR(c_idle.idle); 664 idle = c_idle.idle; 665 current_set[cpu] = c_idle.idle; 666 } 667 init_idle(idle, cpu); 668 if (smp_alloc_lowcore(cpu)) 669 return -ENOMEM; 670 do { 671 ccode = sigp(cpu, sigp_initial_cpu_reset); 672 if (ccode == sigp_busy) 673 udelay(10); 674 if (ccode == sigp_not_operational) 675 goto err_out; 676 } while (ccode == sigp_busy); 677 678 lowcore = (u32)(unsigned long)lowcore_ptr[cpu]; 679 while (sigp_p(lowcore, cpu, sigp_set_prefix) == sigp_busy) 680 udelay(10); 681 682 cpu_lowcore = lowcore_ptr[cpu]; 683 cpu_lowcore->kernel_stack = (unsigned long) 684 task_stack_page(idle) + THREAD_SIZE; 685 cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle); 686 sf = (struct stack_frame *) (cpu_lowcore->kernel_stack 687 - sizeof(struct pt_regs) 688 - sizeof(struct stack_frame)); 689 memset(sf, 0, sizeof(struct stack_frame)); 690 sf->gprs[9] = (unsigned long) sf; 691 cpu_lowcore->gpregs_save_area[15] = (unsigned long) sf; 692 __ctl_store(cpu_lowcore->cregs_save_area, 0, 15); 693 atomic_inc(&init_mm.context.attach_count); 694 asm volatile( 695 " stam 0,15,0(%0)" 696 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory"); 697 cpu_lowcore->percpu_offset = __per_cpu_offset[cpu]; 698 cpu_lowcore->current_task = (unsigned long) idle; 699 cpu_lowcore->cpu_nr = cpu; 700 cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce; 701 cpu_lowcore->machine_flags = S390_lowcore.machine_flags; 702 cpu_lowcore->ftrace_func = S390_lowcore.ftrace_func; 703 memcpy(cpu_lowcore->stfle_fac_list, S390_lowcore.stfle_fac_list, 704 MAX_FACILITY_BIT/8); 705 eieio(); 706 707 while (sigp(cpu, sigp_restart) == sigp_busy) 708 udelay(10); 709 710 while (!cpu_online(cpu)) 711 cpu_relax(); 712 return 0; 713 714 err_out: 715 smp_free_lowcore(cpu); 716 return -EIO; 717 } 718 719 static int __init setup_possible_cpus(char *s) 720 { 721 int pcpus, cpu; 722 723 pcpus = simple_strtoul(s, NULL, 0); 724 init_cpu_possible(cpumask_of(0)); 725 for (cpu = 1; cpu < pcpus && cpu < nr_cpu_ids; cpu++) 726 set_cpu_possible(cpu, true); 727 return 0; 728 } 729 early_param("possible_cpus", setup_possible_cpus); 730 731 #ifdef CONFIG_HOTPLUG_CPU 732 733 int __cpu_disable(void) 734 { 735 struct ec_creg_mask_parms cr_parms; 736 int cpu = smp_processor_id(); 737 738 set_cpu_online(cpu, false); 739 740 /* Disable pfault pseudo page faults on this cpu. */ 741 pfault_fini(); 742 743 memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals)); 744 memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals)); 745 746 /* disable all external interrupts */ 747 cr_parms.orvals[0] = 0; 748 cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 11 | 749 1 << 10 | 1 << 9 | 1 << 6 | 1 << 5 | 750 1 << 4); 751 /* disable all I/O interrupts */ 752 cr_parms.orvals[6] = 0; 753 cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 | 754 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24); 755 /* disable most machine checks */ 756 cr_parms.orvals[14] = 0; 757 cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 | 758 1 << 25 | 1 << 24); 759 760 smp_ctl_bit_callback(&cr_parms); 761 762 return 0; 763 } 764 765 void __cpu_die(unsigned int cpu) 766 { 767 /* Wait until target cpu is down */ 768 while (!cpu_stopped(cpu)) 769 cpu_relax(); 770 while (sigp_p(0, cpu, sigp_set_prefix) == sigp_busy) 771 udelay(10); 772 smp_free_lowcore(cpu); 773 atomic_dec(&init_mm.context.attach_count); 774 } 775 776 void __noreturn cpu_die(void) 777 { 778 idle_task_exit(); 779 while (sigp(smp_processor_id(), sigp_stop) == sigp_busy) 780 cpu_relax(); 781 for (;;); 782 } 783 784 #endif /* CONFIG_HOTPLUG_CPU */ 785 786 void __init smp_prepare_cpus(unsigned int max_cpus) 787 { 788 #ifndef CONFIG_64BIT 789 unsigned long save_area = 0; 790 #endif 791 unsigned long async_stack, panic_stack; 792 struct _lowcore *lowcore; 793 794 smp_detect_cpus(); 795 796 /* request the 0x1201 emergency signal external interrupt */ 797 if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0) 798 panic("Couldn't request external interrupt 0x1201"); 799 /* request the 0x1202 external call external interrupt */ 800 if (register_external_interrupt(0x1202, do_ext_call_interrupt) != 0) 801 panic("Couldn't request external interrupt 0x1202"); 802 803 /* Reallocate current lowcore, but keep its contents. */ 804 lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); 805 panic_stack = __get_free_page(GFP_KERNEL); 806 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER); 807 BUG_ON(!lowcore || !panic_stack || !async_stack); 808 #ifndef CONFIG_64BIT 809 if (MACHINE_HAS_IEEE) 810 save_area = get_zeroed_page(GFP_KERNEL); 811 #endif 812 local_irq_disable(); 813 local_mcck_disable(); 814 lowcore_ptr[smp_processor_id()] = lowcore; 815 *lowcore = S390_lowcore; 816 lowcore->panic_stack = panic_stack + PAGE_SIZE; 817 lowcore->async_stack = async_stack + ASYNC_SIZE; 818 #ifndef CONFIG_64BIT 819 if (MACHINE_HAS_IEEE) 820 lowcore->extended_save_area_addr = (u32) save_area; 821 #endif 822 set_prefix((u32)(unsigned long) lowcore); 823 local_mcck_enable(); 824 local_irq_enable(); 825 #ifdef CONFIG_64BIT 826 if (vdso_alloc_per_cpu(smp_processor_id(), &S390_lowcore)) 827 BUG(); 828 #endif 829 } 830 831 void __init smp_prepare_boot_cpu(void) 832 { 833 BUG_ON(smp_processor_id() != 0); 834 835 current_thread_info()->cpu = 0; 836 set_cpu_present(0, true); 837 set_cpu_online(0, true); 838 S390_lowcore.percpu_offset = __per_cpu_offset[0]; 839 current_set[0] = current; 840 smp_cpu_state[0] = CPU_STATE_CONFIGURED; 841 cpu_set_polarization(0, POLARIZATION_UNKNOWN); 842 } 843 844 void __init smp_cpus_done(unsigned int max_cpus) 845 { 846 } 847 848 void __init smp_setup_processor_id(void) 849 { 850 S390_lowcore.cpu_nr = 0; 851 __cpu_logical_map[0] = stap(); 852 } 853 854 /* 855 * the frequency of the profiling timer can be changed 856 * by writing a multiplier value into /proc/profile. 857 * 858 * usually you want to run this on all CPUs ;) 859 */ 860 int setup_profiling_timer(unsigned int multiplier) 861 { 862 return 0; 863 } 864 865 #ifdef CONFIG_HOTPLUG_CPU 866 static ssize_t cpu_configure_show(struct device *dev, 867 struct device_attribute *attr, char *buf) 868 { 869 ssize_t count; 870 871 mutex_lock(&smp_cpu_state_mutex); 872 count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]); 873 mutex_unlock(&smp_cpu_state_mutex); 874 return count; 875 } 876 877 static ssize_t cpu_configure_store(struct device *dev, 878 struct device_attribute *attr, 879 const char *buf, size_t count) 880 { 881 int cpu = dev->id; 882 int val, rc; 883 char delim; 884 885 if (sscanf(buf, "%d %c", &val, &delim) != 1) 886 return -EINVAL; 887 if (val != 0 && val != 1) 888 return -EINVAL; 889 890 get_online_cpus(); 891 mutex_lock(&smp_cpu_state_mutex); 892 rc = -EBUSY; 893 /* disallow configuration changes of online cpus and cpu 0 */ 894 if (cpu_online(cpu) || cpu == 0) 895 goto out; 896 rc = 0; 897 switch (val) { 898 case 0: 899 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) { 900 rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]); 901 if (!rc) { 902 smp_cpu_state[cpu] = CPU_STATE_STANDBY; 903 cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 904 topology_expect_change(); 905 } 906 } 907 break; 908 case 1: 909 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) { 910 rc = sclp_cpu_configure(__cpu_logical_map[cpu]); 911 if (!rc) { 912 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED; 913 cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 914 topology_expect_change(); 915 } 916 } 917 break; 918 default: 919 break; 920 } 921 out: 922 mutex_unlock(&smp_cpu_state_mutex); 923 put_online_cpus(); 924 return rc ? rc : count; 925 } 926 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store); 927 #endif /* CONFIG_HOTPLUG_CPU */ 928 929 static ssize_t show_cpu_address(struct device *dev, 930 struct device_attribute *attr, char *buf) 931 { 932 return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]); 933 } 934 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL); 935 936 static struct attribute *cpu_common_attrs[] = { 937 #ifdef CONFIG_HOTPLUG_CPU 938 &dev_attr_configure.attr, 939 #endif 940 &dev_attr_address.attr, 941 NULL, 942 }; 943 944 static struct attribute_group cpu_common_attr_group = { 945 .attrs = cpu_common_attrs, 946 }; 947 948 static ssize_t show_capability(struct device *dev, 949 struct device_attribute *attr, char *buf) 950 { 951 unsigned int capability; 952 int rc; 953 954 rc = get_cpu_capability(&capability); 955 if (rc) 956 return rc; 957 return sprintf(buf, "%u\n", capability); 958 } 959 static DEVICE_ATTR(capability, 0444, show_capability, NULL); 960 961 static ssize_t show_idle_count(struct device *dev, 962 struct device_attribute *attr, char *buf) 963 { 964 struct s390_idle_data *idle; 965 unsigned long long idle_count; 966 unsigned int sequence; 967 968 idle = &per_cpu(s390_idle, dev->id); 969 repeat: 970 sequence = idle->sequence; 971 smp_rmb(); 972 if (sequence & 1) 973 goto repeat; 974 idle_count = idle->idle_count; 975 if (idle->idle_enter) 976 idle_count++; 977 smp_rmb(); 978 if (idle->sequence != sequence) 979 goto repeat; 980 return sprintf(buf, "%llu\n", idle_count); 981 } 982 static DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL); 983 984 static ssize_t show_idle_time(struct device *dev, 985 struct device_attribute *attr, char *buf) 986 { 987 struct s390_idle_data *idle; 988 unsigned long long now, idle_time, idle_enter; 989 unsigned int sequence; 990 991 idle = &per_cpu(s390_idle, dev->id); 992 now = get_clock(); 993 repeat: 994 sequence = idle->sequence; 995 smp_rmb(); 996 if (sequence & 1) 997 goto repeat; 998 idle_time = idle->idle_time; 999 idle_enter = idle->idle_enter; 1000 if (idle_enter != 0ULL && idle_enter < now) 1001 idle_time += now - idle_enter; 1002 smp_rmb(); 1003 if (idle->sequence != sequence) 1004 goto repeat; 1005 return sprintf(buf, "%llu\n", idle_time >> 12); 1006 } 1007 static DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL); 1008 1009 static struct attribute *cpu_online_attrs[] = { 1010 &dev_attr_capability.attr, 1011 &dev_attr_idle_count.attr, 1012 &dev_attr_idle_time_us.attr, 1013 NULL, 1014 }; 1015 1016 static struct attribute_group cpu_online_attr_group = { 1017 .attrs = cpu_online_attrs, 1018 }; 1019 1020 static int __cpuinit smp_cpu_notify(struct notifier_block *self, 1021 unsigned long action, void *hcpu) 1022 { 1023 unsigned int cpu = (unsigned int)(long)hcpu; 1024 struct cpu *c = &per_cpu(cpu_devices, cpu); 1025 struct device *s = &c->dev; 1026 struct s390_idle_data *idle; 1027 int err = 0; 1028 1029 switch (action) { 1030 case CPU_ONLINE: 1031 case CPU_ONLINE_FROZEN: 1032 idle = &per_cpu(s390_idle, cpu); 1033 memset(idle, 0, sizeof(struct s390_idle_data)); 1034 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 1035 break; 1036 case CPU_DEAD: 1037 case CPU_DEAD_FROZEN: 1038 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 1039 break; 1040 } 1041 return notifier_from_errno(err); 1042 } 1043 1044 static struct notifier_block __cpuinitdata smp_cpu_nb = { 1045 .notifier_call = smp_cpu_notify, 1046 }; 1047 1048 static int __devinit smp_add_present_cpu(int cpu) 1049 { 1050 struct cpu *c = &per_cpu(cpu_devices, cpu); 1051 struct device *s = &c->dev; 1052 int rc; 1053 1054 c->hotpluggable = 1; 1055 rc = register_cpu(c, cpu); 1056 if (rc) 1057 goto out; 1058 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group); 1059 if (rc) 1060 goto out_cpu; 1061 if (cpu_online(cpu)) { 1062 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 1063 if (rc) 1064 goto out_online; 1065 } 1066 rc = topology_cpu_init(c); 1067 if (rc) 1068 goto out_topology; 1069 return 0; 1070 1071 out_topology: 1072 if (cpu_online(cpu)) 1073 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 1074 out_online: 1075 sysfs_remove_group(&s->kobj, &cpu_common_attr_group); 1076 out_cpu: 1077 #ifdef CONFIG_HOTPLUG_CPU 1078 unregister_cpu(c); 1079 #endif 1080 out: 1081 return rc; 1082 } 1083 1084 #ifdef CONFIG_HOTPLUG_CPU 1085 1086 int __ref smp_rescan_cpus(void) 1087 { 1088 cpumask_t newcpus; 1089 int cpu; 1090 int rc; 1091 1092 get_online_cpus(); 1093 mutex_lock(&smp_cpu_state_mutex); 1094 cpumask_copy(&newcpus, cpu_present_mask); 1095 rc = __smp_rescan_cpus(); 1096 if (rc) 1097 goto out; 1098 cpumask_andnot(&newcpus, cpu_present_mask, &newcpus); 1099 for_each_cpu(cpu, &newcpus) { 1100 rc = smp_add_present_cpu(cpu); 1101 if (rc) 1102 set_cpu_present(cpu, false); 1103 } 1104 rc = 0; 1105 out: 1106 mutex_unlock(&smp_cpu_state_mutex); 1107 put_online_cpus(); 1108 if (!cpumask_empty(&newcpus)) 1109 topology_schedule_update(); 1110 return rc; 1111 } 1112 1113 static ssize_t __ref rescan_store(struct device *dev, 1114 struct device_attribute *attr, 1115 const char *buf, 1116 size_t count) 1117 { 1118 int rc; 1119 1120 rc = smp_rescan_cpus(); 1121 return rc ? rc : count; 1122 } 1123 static DEVICE_ATTR(rescan, 0200, NULL, rescan_store); 1124 #endif /* CONFIG_HOTPLUG_CPU */ 1125 1126 static int __init s390_smp_init(void) 1127 { 1128 int cpu, rc; 1129 1130 register_cpu_notifier(&smp_cpu_nb); 1131 #ifdef CONFIG_HOTPLUG_CPU 1132 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan); 1133 if (rc) 1134 return rc; 1135 #endif 1136 for_each_present_cpu(cpu) { 1137 rc = smp_add_present_cpu(cpu); 1138 if (rc) 1139 return rc; 1140 } 1141 return 0; 1142 } 1143 subsys_initcall(s390_smp_init); 1144