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 int smp_cpu_polarization[NR_CPUS]; 73 static int smp_cpu_state[NR_CPUS]; 74 static int cpu_management; 75 76 static DEFINE_PER_CPU(struct cpu, cpu_devices); 77 78 static void smp_ext_bitcall(int, int); 79 80 static int raw_cpu_stopped(int cpu) 81 { 82 u32 status; 83 84 switch (raw_sigp_ps(&status, 0, cpu, sigp_sense)) { 85 case sigp_status_stored: 86 /* Check for stopped and check stop state */ 87 if (status & 0x50) 88 return 1; 89 break; 90 default: 91 break; 92 } 93 return 0; 94 } 95 96 static inline int cpu_stopped(int cpu) 97 { 98 return raw_cpu_stopped(cpu_logical_map(cpu)); 99 } 100 101 /* 102 * Ensure that PSW restart is done on an online CPU 103 */ 104 void smp_restart_with_online_cpu(void) 105 { 106 int cpu; 107 108 for_each_online_cpu(cpu) { 109 if (stap() == __cpu_logical_map[cpu]) { 110 /* We are online: Enable DAT again and return */ 111 __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT); 112 return; 113 } 114 } 115 /* We are not online: Do PSW restart on an online CPU */ 116 while (sigp(cpu, sigp_restart) == sigp_busy) 117 cpu_relax(); 118 /* And stop ourself */ 119 while (raw_sigp(stap(), sigp_stop) == sigp_busy) 120 cpu_relax(); 121 for (;;); 122 } 123 124 void smp_switch_to_ipl_cpu(void (*func)(void *), void *data) 125 { 126 struct _lowcore *lc, *current_lc; 127 struct stack_frame *sf; 128 struct pt_regs *regs; 129 unsigned long sp; 130 131 if (smp_processor_id() == 0) 132 func(data); 133 __load_psw_mask(PSW_DEFAULT_KEY | PSW_MASK_BASE | 134 PSW_MASK_EA | PSW_MASK_BA); 135 /* Disable lowcore protection */ 136 __ctl_clear_bit(0, 28); 137 current_lc = lowcore_ptr[smp_processor_id()]; 138 lc = lowcore_ptr[0]; 139 if (!lc) 140 lc = current_lc; 141 lc->restart_psw.mask = 142 PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA; 143 lc->restart_psw.addr = PSW_ADDR_AMODE | (unsigned long) smp_restart_cpu; 144 if (!cpu_online(0)) 145 smp_switch_to_cpu(func, data, 0, stap(), __cpu_logical_map[0]); 146 while (sigp(0, sigp_stop_and_store_status) == sigp_busy) 147 cpu_relax(); 148 sp = lc->panic_stack; 149 sp -= sizeof(struct pt_regs); 150 regs = (struct pt_regs *) sp; 151 memcpy(®s->gprs, ¤t_lc->gpregs_save_area, sizeof(regs->gprs)); 152 regs->psw = lc->psw_save_area; 153 sp -= STACK_FRAME_OVERHEAD; 154 sf = (struct stack_frame *) sp; 155 sf->back_chain = regs->gprs[15]; 156 smp_switch_to_cpu(func, data, sp, stap(), __cpu_logical_map[0]); 157 } 158 159 void smp_send_stop(void) 160 { 161 int cpu, rc; 162 163 /* Disable all interrupts/machine checks */ 164 __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT); 165 trace_hardirqs_off(); 166 167 /* stop all processors */ 168 for_each_online_cpu(cpu) { 169 if (cpu == smp_processor_id()) 170 continue; 171 do { 172 rc = sigp(cpu, sigp_stop); 173 } while (rc == sigp_busy); 174 175 while (!cpu_stopped(cpu)) 176 cpu_relax(); 177 } 178 } 179 180 /* 181 * This is the main routine where commands issued by other 182 * cpus are handled. 183 */ 184 185 static void do_ext_call_interrupt(unsigned int ext_int_code, 186 unsigned int param32, unsigned long param64) 187 { 188 unsigned long bits; 189 190 if (ext_int_code == 0x1202) 191 kstat_cpu(smp_processor_id()).irqs[EXTINT_EXC]++; 192 else 193 kstat_cpu(smp_processor_id()).irqs[EXTINT_EMS]++; 194 /* 195 * handle bit signal external calls 196 */ 197 bits = xchg(&S390_lowcore.ext_call_fast, 0); 198 199 if (test_bit(ec_schedule, &bits)) 200 scheduler_ipi(); 201 202 if (test_bit(ec_call_function, &bits)) 203 generic_smp_call_function_interrupt(); 204 205 if (test_bit(ec_call_function_single, &bits)) 206 generic_smp_call_function_single_interrupt(); 207 } 208 209 /* 210 * Send an external call sigp to another cpu and return without waiting 211 * for its completion. 212 */ 213 static void smp_ext_bitcall(int cpu, int sig) 214 { 215 int order; 216 217 /* 218 * Set signaling bit in lowcore of target cpu and kick it 219 */ 220 set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast); 221 while (1) { 222 order = smp_vcpu_scheduled(cpu) ? 223 sigp_external_call : sigp_emergency_signal; 224 if (sigp(cpu, order) != sigp_busy) 225 break; 226 udelay(10); 227 } 228 } 229 230 void arch_send_call_function_ipi_mask(const struct cpumask *mask) 231 { 232 int cpu; 233 234 for_each_cpu(cpu, mask) 235 smp_ext_bitcall(cpu, ec_call_function); 236 } 237 238 void arch_send_call_function_single_ipi(int cpu) 239 { 240 smp_ext_bitcall(cpu, ec_call_function_single); 241 } 242 243 #ifndef CONFIG_64BIT 244 /* 245 * this function sends a 'purge tlb' signal to another CPU. 246 */ 247 static void smp_ptlb_callback(void *info) 248 { 249 __tlb_flush_local(); 250 } 251 252 void smp_ptlb_all(void) 253 { 254 on_each_cpu(smp_ptlb_callback, NULL, 1); 255 } 256 EXPORT_SYMBOL(smp_ptlb_all); 257 #endif /* ! CONFIG_64BIT */ 258 259 /* 260 * this function sends a 'reschedule' IPI to another CPU. 261 * it goes straight through and wastes no time serializing 262 * anything. Worst case is that we lose a reschedule ... 263 */ 264 void smp_send_reschedule(int cpu) 265 { 266 smp_ext_bitcall(cpu, ec_schedule); 267 } 268 269 /* 270 * parameter area for the set/clear control bit callbacks 271 */ 272 struct ec_creg_mask_parms { 273 unsigned long orvals[16]; 274 unsigned long andvals[16]; 275 }; 276 277 /* 278 * callback for setting/clearing control bits 279 */ 280 static void smp_ctl_bit_callback(void *info) 281 { 282 struct ec_creg_mask_parms *pp = info; 283 unsigned long cregs[16]; 284 int i; 285 286 __ctl_store(cregs, 0, 15); 287 for (i = 0; i <= 15; i++) 288 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i]; 289 __ctl_load(cregs, 0, 15); 290 } 291 292 /* 293 * Set a bit in a control register of all cpus 294 */ 295 void smp_ctl_set_bit(int cr, int bit) 296 { 297 struct ec_creg_mask_parms parms; 298 299 memset(&parms.orvals, 0, sizeof(parms.orvals)); 300 memset(&parms.andvals, 0xff, sizeof(parms.andvals)); 301 parms.orvals[cr] = 1UL << bit; 302 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 303 } 304 EXPORT_SYMBOL(smp_ctl_set_bit); 305 306 /* 307 * Clear a bit in a control register of all cpus 308 */ 309 void smp_ctl_clear_bit(int cr, int bit) 310 { 311 struct ec_creg_mask_parms parms; 312 313 memset(&parms.orvals, 0, sizeof(parms.orvals)); 314 memset(&parms.andvals, 0xff, sizeof(parms.andvals)); 315 parms.andvals[cr] = ~(1UL << bit); 316 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 317 } 318 EXPORT_SYMBOL(smp_ctl_clear_bit); 319 320 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_CRASH_DUMP) 321 322 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) 323 { 324 if (ipl_info.type != IPL_TYPE_FCP_DUMP && !OLDMEM_BASE) 325 return; 326 if (is_kdump_kernel()) 327 return; 328 if (cpu >= NR_CPUS) { 329 pr_warning("CPU %i exceeds the maximum %i and is excluded from " 330 "the dump\n", cpu, NR_CPUS - 1); 331 return; 332 } 333 zfcpdump_save_areas[cpu] = kmalloc(sizeof(struct save_area), GFP_KERNEL); 334 while (raw_sigp(phy_cpu, sigp_stop_and_store_status) == sigp_busy) 335 cpu_relax(); 336 memcpy_real(zfcpdump_save_areas[cpu], 337 (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE, 338 sizeof(struct save_area)); 339 } 340 341 struct save_area *zfcpdump_save_areas[NR_CPUS + 1]; 342 EXPORT_SYMBOL_GPL(zfcpdump_save_areas); 343 344 #else 345 346 static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { } 347 348 #endif /* CONFIG_ZFCPDUMP */ 349 350 static int cpu_known(int cpu_id) 351 { 352 int cpu; 353 354 for_each_present_cpu(cpu) { 355 if (__cpu_logical_map[cpu] == cpu_id) 356 return 1; 357 } 358 return 0; 359 } 360 361 static int smp_rescan_cpus_sigp(cpumask_t avail) 362 { 363 int cpu_id, logical_cpu; 364 365 logical_cpu = cpumask_first(&avail); 366 if (logical_cpu >= nr_cpu_ids) 367 return 0; 368 for (cpu_id = 0; cpu_id <= MAX_CPU_ADDRESS; cpu_id++) { 369 if (cpu_known(cpu_id)) 370 continue; 371 __cpu_logical_map[logical_cpu] = cpu_id; 372 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN; 373 if (!cpu_stopped(logical_cpu)) 374 continue; 375 set_cpu_present(logical_cpu, true); 376 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED; 377 logical_cpu = cpumask_next(logical_cpu, &avail); 378 if (logical_cpu >= nr_cpu_ids) 379 break; 380 } 381 return 0; 382 } 383 384 static int smp_rescan_cpus_sclp(cpumask_t avail) 385 { 386 struct sclp_cpu_info *info; 387 int cpu_id, logical_cpu, cpu; 388 int rc; 389 390 logical_cpu = cpumask_first(&avail); 391 if (logical_cpu >= nr_cpu_ids) 392 return 0; 393 info = kmalloc(sizeof(*info), GFP_KERNEL); 394 if (!info) 395 return -ENOMEM; 396 rc = sclp_get_cpu_info(info); 397 if (rc) 398 goto out; 399 for (cpu = 0; cpu < info->combined; cpu++) { 400 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type) 401 continue; 402 cpu_id = info->cpu[cpu].address; 403 if (cpu_known(cpu_id)) 404 continue; 405 __cpu_logical_map[logical_cpu] = cpu_id; 406 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN; 407 set_cpu_present(logical_cpu, true); 408 if (cpu >= info->configured) 409 smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY; 410 else 411 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED; 412 logical_cpu = cpumask_next(logical_cpu, &avail); 413 if (logical_cpu >= nr_cpu_ids) 414 break; 415 } 416 out: 417 kfree(info); 418 return rc; 419 } 420 421 static int __smp_rescan_cpus(void) 422 { 423 cpumask_t avail; 424 425 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask); 426 if (smp_use_sigp_detection) 427 return smp_rescan_cpus_sigp(avail); 428 else 429 return smp_rescan_cpus_sclp(avail); 430 } 431 432 static void __init smp_detect_cpus(void) 433 { 434 unsigned int cpu, c_cpus, s_cpus; 435 struct sclp_cpu_info *info; 436 u16 boot_cpu_addr, cpu_addr; 437 438 c_cpus = 1; 439 s_cpus = 0; 440 boot_cpu_addr = __cpu_logical_map[0]; 441 info = kmalloc(sizeof(*info), GFP_KERNEL); 442 if (!info) 443 panic("smp_detect_cpus failed to allocate memory\n"); 444 #ifdef CONFIG_CRASH_DUMP 445 if (OLDMEM_BASE && !is_kdump_kernel()) { 446 struct save_area *save_area; 447 448 save_area = kmalloc(sizeof(*save_area), GFP_KERNEL); 449 if (!save_area) 450 panic("could not allocate memory for save area\n"); 451 copy_oldmem_page(1, (void *) save_area, sizeof(*save_area), 452 0x200, 0); 453 zfcpdump_save_areas[0] = save_area; 454 } 455 #endif 456 /* Use sigp detection algorithm if sclp doesn't work. */ 457 if (sclp_get_cpu_info(info)) { 458 smp_use_sigp_detection = 1; 459 for (cpu = 0; cpu <= MAX_CPU_ADDRESS; cpu++) { 460 if (cpu == boot_cpu_addr) 461 continue; 462 if (!raw_cpu_stopped(cpu)) 463 continue; 464 smp_get_save_area(c_cpus, cpu); 465 c_cpus++; 466 } 467 goto out; 468 } 469 470 if (info->has_cpu_type) { 471 for (cpu = 0; cpu < info->combined; cpu++) { 472 if (info->cpu[cpu].address == boot_cpu_addr) { 473 smp_cpu_type = info->cpu[cpu].type; 474 break; 475 } 476 } 477 } 478 479 for (cpu = 0; cpu < info->combined; cpu++) { 480 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type) 481 continue; 482 cpu_addr = info->cpu[cpu].address; 483 if (cpu_addr == boot_cpu_addr) 484 continue; 485 if (!raw_cpu_stopped(cpu_addr)) { 486 s_cpus++; 487 continue; 488 } 489 smp_get_save_area(c_cpus, cpu_addr); 490 c_cpus++; 491 } 492 out: 493 kfree(info); 494 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus); 495 get_online_cpus(); 496 __smp_rescan_cpus(); 497 put_online_cpus(); 498 } 499 500 /* 501 * Activate a secondary processor. 502 */ 503 int __cpuinit start_secondary(void *cpuvoid) 504 { 505 cpu_init(); 506 preempt_disable(); 507 init_cpu_timer(); 508 init_cpu_vtimer(); 509 pfault_init(); 510 511 notify_cpu_starting(smp_processor_id()); 512 ipi_call_lock(); 513 set_cpu_online(smp_processor_id(), true); 514 ipi_call_unlock(); 515 __ctl_clear_bit(0, 28); /* Disable lowcore protection */ 516 S390_lowcore.restart_psw.mask = 517 PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA; 518 S390_lowcore.restart_psw.addr = 519 PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler; 520 __ctl_set_bit(0, 28); /* Enable lowcore protection */ 521 /* 522 * Wait until the cpu which brought this one up marked it 523 * active before enabling interrupts. 524 */ 525 while (!cpumask_test_cpu(smp_processor_id(), cpu_active_mask)) 526 cpu_relax(); 527 local_irq_enable(); 528 /* cpu_idle will call schedule for us */ 529 cpu_idle(); 530 return 0; 531 } 532 533 struct create_idle { 534 struct work_struct work; 535 struct task_struct *idle; 536 struct completion done; 537 int cpu; 538 }; 539 540 static void __cpuinit smp_fork_idle(struct work_struct *work) 541 { 542 struct create_idle *c_idle; 543 544 c_idle = container_of(work, struct create_idle, work); 545 c_idle->idle = fork_idle(c_idle->cpu); 546 complete(&c_idle->done); 547 } 548 549 static int __cpuinit smp_alloc_lowcore(int cpu) 550 { 551 unsigned long async_stack, panic_stack; 552 struct _lowcore *lowcore; 553 554 lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); 555 if (!lowcore) 556 return -ENOMEM; 557 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER); 558 panic_stack = __get_free_page(GFP_KERNEL); 559 if (!panic_stack || !async_stack) 560 goto out; 561 memcpy(lowcore, &S390_lowcore, 512); 562 memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512); 563 lowcore->async_stack = async_stack + ASYNC_SIZE; 564 lowcore->panic_stack = panic_stack + PAGE_SIZE; 565 lowcore->restart_psw.mask = 566 PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA; 567 lowcore->restart_psw.addr = 568 PSW_ADDR_AMODE | (unsigned long) restart_int_handler; 569 if (user_mode != HOME_SPACE_MODE) 570 lowcore->restart_psw.mask |= PSW_ASC_HOME; 571 #ifndef CONFIG_64BIT 572 if (MACHINE_HAS_IEEE) { 573 unsigned long save_area; 574 575 save_area = get_zeroed_page(GFP_KERNEL); 576 if (!save_area) 577 goto out; 578 lowcore->extended_save_area_addr = (u32) save_area; 579 } 580 #else 581 if (vdso_alloc_per_cpu(cpu, lowcore)) 582 goto out; 583 #endif 584 lowcore_ptr[cpu] = lowcore; 585 return 0; 586 587 out: 588 free_page(panic_stack); 589 free_pages(async_stack, ASYNC_ORDER); 590 free_pages((unsigned long) lowcore, LC_ORDER); 591 return -ENOMEM; 592 } 593 594 static void smp_free_lowcore(int cpu) 595 { 596 struct _lowcore *lowcore; 597 598 lowcore = lowcore_ptr[cpu]; 599 #ifndef CONFIG_64BIT 600 if (MACHINE_HAS_IEEE) 601 free_page((unsigned long) lowcore->extended_save_area_addr); 602 #else 603 vdso_free_per_cpu(cpu, lowcore); 604 #endif 605 free_page(lowcore->panic_stack - PAGE_SIZE); 606 free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER); 607 free_pages((unsigned long) lowcore, LC_ORDER); 608 lowcore_ptr[cpu] = NULL; 609 } 610 611 /* Upping and downing of CPUs */ 612 int __cpuinit __cpu_up(unsigned int cpu) 613 { 614 struct _lowcore *cpu_lowcore; 615 struct create_idle c_idle; 616 struct task_struct *idle; 617 struct stack_frame *sf; 618 u32 lowcore; 619 int ccode; 620 621 if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED) 622 return -EIO; 623 idle = current_set[cpu]; 624 if (!idle) { 625 c_idle.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done); 626 INIT_WORK_ONSTACK(&c_idle.work, smp_fork_idle); 627 c_idle.cpu = cpu; 628 schedule_work(&c_idle.work); 629 wait_for_completion(&c_idle.done); 630 if (IS_ERR(c_idle.idle)) 631 return PTR_ERR(c_idle.idle); 632 idle = c_idle.idle; 633 current_set[cpu] = c_idle.idle; 634 } 635 init_idle(idle, cpu); 636 if (smp_alloc_lowcore(cpu)) 637 return -ENOMEM; 638 do { 639 ccode = sigp(cpu, sigp_initial_cpu_reset); 640 if (ccode == sigp_busy) 641 udelay(10); 642 if (ccode == sigp_not_operational) 643 goto err_out; 644 } while (ccode == sigp_busy); 645 646 lowcore = (u32)(unsigned long)lowcore_ptr[cpu]; 647 while (sigp_p(lowcore, cpu, sigp_set_prefix) == sigp_busy) 648 udelay(10); 649 650 cpu_lowcore = lowcore_ptr[cpu]; 651 cpu_lowcore->kernel_stack = (unsigned long) 652 task_stack_page(idle) + THREAD_SIZE; 653 cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle); 654 sf = (struct stack_frame *) (cpu_lowcore->kernel_stack 655 - sizeof(struct pt_regs) 656 - sizeof(struct stack_frame)); 657 memset(sf, 0, sizeof(struct stack_frame)); 658 sf->gprs[9] = (unsigned long) sf; 659 cpu_lowcore->save_area[15] = (unsigned long) sf; 660 __ctl_store(cpu_lowcore->cregs_save_area, 0, 15); 661 atomic_inc(&init_mm.context.attach_count); 662 asm volatile( 663 " stam 0,15,0(%0)" 664 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory"); 665 cpu_lowcore->percpu_offset = __per_cpu_offset[cpu]; 666 cpu_lowcore->current_task = (unsigned long) idle; 667 cpu_lowcore->cpu_nr = cpu; 668 cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce; 669 cpu_lowcore->machine_flags = S390_lowcore.machine_flags; 670 cpu_lowcore->ftrace_func = S390_lowcore.ftrace_func; 671 memcpy(cpu_lowcore->stfle_fac_list, S390_lowcore.stfle_fac_list, 672 MAX_FACILITY_BIT/8); 673 eieio(); 674 675 while (sigp(cpu, sigp_restart) == sigp_busy) 676 udelay(10); 677 678 while (!cpu_online(cpu)) 679 cpu_relax(); 680 return 0; 681 682 err_out: 683 smp_free_lowcore(cpu); 684 return -EIO; 685 } 686 687 static int __init setup_possible_cpus(char *s) 688 { 689 int pcpus, cpu; 690 691 pcpus = simple_strtoul(s, NULL, 0); 692 init_cpu_possible(cpumask_of(0)); 693 for (cpu = 1; cpu < pcpus && cpu < nr_cpu_ids; cpu++) 694 set_cpu_possible(cpu, true); 695 return 0; 696 } 697 early_param("possible_cpus", setup_possible_cpus); 698 699 #ifdef CONFIG_HOTPLUG_CPU 700 701 int __cpu_disable(void) 702 { 703 struct ec_creg_mask_parms cr_parms; 704 int cpu = smp_processor_id(); 705 706 set_cpu_online(cpu, false); 707 708 /* Disable pfault pseudo page faults on this cpu. */ 709 pfault_fini(); 710 711 memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals)); 712 memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals)); 713 714 /* disable all external interrupts */ 715 cr_parms.orvals[0] = 0; 716 cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 11 | 717 1 << 10 | 1 << 9 | 1 << 6 | 1 << 5 | 718 1 << 4); 719 /* disable all I/O interrupts */ 720 cr_parms.orvals[6] = 0; 721 cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 | 722 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24); 723 /* disable most machine checks */ 724 cr_parms.orvals[14] = 0; 725 cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 | 726 1 << 25 | 1 << 24); 727 728 smp_ctl_bit_callback(&cr_parms); 729 730 return 0; 731 } 732 733 void __cpu_die(unsigned int cpu) 734 { 735 /* Wait until target cpu is down */ 736 while (!cpu_stopped(cpu)) 737 cpu_relax(); 738 while (sigp_p(0, cpu, sigp_set_prefix) == sigp_busy) 739 udelay(10); 740 smp_free_lowcore(cpu); 741 atomic_dec(&init_mm.context.attach_count); 742 } 743 744 void __noreturn cpu_die(void) 745 { 746 idle_task_exit(); 747 while (sigp(smp_processor_id(), sigp_stop) == sigp_busy) 748 cpu_relax(); 749 for (;;); 750 } 751 752 #endif /* CONFIG_HOTPLUG_CPU */ 753 754 void __init smp_prepare_cpus(unsigned int max_cpus) 755 { 756 #ifndef CONFIG_64BIT 757 unsigned long save_area = 0; 758 #endif 759 unsigned long async_stack, panic_stack; 760 struct _lowcore *lowcore; 761 762 smp_detect_cpus(); 763 764 /* request the 0x1201 emergency signal external interrupt */ 765 if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0) 766 panic("Couldn't request external interrupt 0x1201"); 767 /* request the 0x1202 external call external interrupt */ 768 if (register_external_interrupt(0x1202, do_ext_call_interrupt) != 0) 769 panic("Couldn't request external interrupt 0x1202"); 770 771 /* Reallocate current lowcore, but keep its contents. */ 772 lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); 773 panic_stack = __get_free_page(GFP_KERNEL); 774 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER); 775 BUG_ON(!lowcore || !panic_stack || !async_stack); 776 #ifndef CONFIG_64BIT 777 if (MACHINE_HAS_IEEE) 778 save_area = get_zeroed_page(GFP_KERNEL); 779 #endif 780 local_irq_disable(); 781 local_mcck_disable(); 782 lowcore_ptr[smp_processor_id()] = lowcore; 783 *lowcore = S390_lowcore; 784 lowcore->panic_stack = panic_stack + PAGE_SIZE; 785 lowcore->async_stack = async_stack + ASYNC_SIZE; 786 #ifndef CONFIG_64BIT 787 if (MACHINE_HAS_IEEE) 788 lowcore->extended_save_area_addr = (u32) save_area; 789 #endif 790 set_prefix((u32)(unsigned long) lowcore); 791 local_mcck_enable(); 792 local_irq_enable(); 793 #ifdef CONFIG_64BIT 794 if (vdso_alloc_per_cpu(smp_processor_id(), &S390_lowcore)) 795 BUG(); 796 #endif 797 } 798 799 void __init smp_prepare_boot_cpu(void) 800 { 801 BUG_ON(smp_processor_id() != 0); 802 803 current_thread_info()->cpu = 0; 804 set_cpu_present(0, true); 805 set_cpu_online(0, true); 806 S390_lowcore.percpu_offset = __per_cpu_offset[0]; 807 current_set[0] = current; 808 smp_cpu_state[0] = CPU_STATE_CONFIGURED; 809 smp_cpu_polarization[0] = POLARIZATION_UNKNWN; 810 } 811 812 void __init smp_cpus_done(unsigned int max_cpus) 813 { 814 } 815 816 void __init smp_setup_processor_id(void) 817 { 818 S390_lowcore.cpu_nr = 0; 819 __cpu_logical_map[0] = stap(); 820 } 821 822 /* 823 * the frequency of the profiling timer can be changed 824 * by writing a multiplier value into /proc/profile. 825 * 826 * usually you want to run this on all CPUs ;) 827 */ 828 int setup_profiling_timer(unsigned int multiplier) 829 { 830 return 0; 831 } 832 833 #ifdef CONFIG_HOTPLUG_CPU 834 static ssize_t cpu_configure_show(struct sys_device *dev, 835 struct sysdev_attribute *attr, char *buf) 836 { 837 ssize_t count; 838 839 mutex_lock(&smp_cpu_state_mutex); 840 count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]); 841 mutex_unlock(&smp_cpu_state_mutex); 842 return count; 843 } 844 845 static ssize_t cpu_configure_store(struct sys_device *dev, 846 struct sysdev_attribute *attr, 847 const char *buf, size_t count) 848 { 849 int cpu = dev->id; 850 int val, rc; 851 char delim; 852 853 if (sscanf(buf, "%d %c", &val, &delim) != 1) 854 return -EINVAL; 855 if (val != 0 && val != 1) 856 return -EINVAL; 857 858 get_online_cpus(); 859 mutex_lock(&smp_cpu_state_mutex); 860 rc = -EBUSY; 861 /* disallow configuration changes of online cpus and cpu 0 */ 862 if (cpu_online(cpu) || cpu == 0) 863 goto out; 864 rc = 0; 865 switch (val) { 866 case 0: 867 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) { 868 rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]); 869 if (!rc) { 870 smp_cpu_state[cpu] = CPU_STATE_STANDBY; 871 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN; 872 } 873 } 874 break; 875 case 1: 876 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) { 877 rc = sclp_cpu_configure(__cpu_logical_map[cpu]); 878 if (!rc) { 879 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED; 880 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN; 881 } 882 } 883 break; 884 default: 885 break; 886 } 887 out: 888 mutex_unlock(&smp_cpu_state_mutex); 889 put_online_cpus(); 890 return rc ? rc : count; 891 } 892 static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store); 893 #endif /* CONFIG_HOTPLUG_CPU */ 894 895 static ssize_t cpu_polarization_show(struct sys_device *dev, 896 struct sysdev_attribute *attr, char *buf) 897 { 898 int cpu = dev->id; 899 ssize_t count; 900 901 mutex_lock(&smp_cpu_state_mutex); 902 switch (smp_cpu_polarization[cpu]) { 903 case POLARIZATION_HRZ: 904 count = sprintf(buf, "horizontal\n"); 905 break; 906 case POLARIZATION_VL: 907 count = sprintf(buf, "vertical:low\n"); 908 break; 909 case POLARIZATION_VM: 910 count = sprintf(buf, "vertical:medium\n"); 911 break; 912 case POLARIZATION_VH: 913 count = sprintf(buf, "vertical:high\n"); 914 break; 915 default: 916 count = sprintf(buf, "unknown\n"); 917 break; 918 } 919 mutex_unlock(&smp_cpu_state_mutex); 920 return count; 921 } 922 static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL); 923 924 static ssize_t show_cpu_address(struct sys_device *dev, 925 struct sysdev_attribute *attr, char *buf) 926 { 927 return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]); 928 } 929 static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL); 930 931 932 static struct attribute *cpu_common_attrs[] = { 933 #ifdef CONFIG_HOTPLUG_CPU 934 &attr_configure.attr, 935 #endif 936 &attr_address.attr, 937 &attr_polarization.attr, 938 NULL, 939 }; 940 941 static struct attribute_group cpu_common_attr_group = { 942 .attrs = cpu_common_attrs, 943 }; 944 945 static ssize_t show_capability(struct sys_device *dev, 946 struct sysdev_attribute *attr, char *buf) 947 { 948 unsigned int capability; 949 int rc; 950 951 rc = get_cpu_capability(&capability); 952 if (rc) 953 return rc; 954 return sprintf(buf, "%u\n", capability); 955 } 956 static SYSDEV_ATTR(capability, 0444, show_capability, NULL); 957 958 static ssize_t show_idle_count(struct sys_device *dev, 959 struct sysdev_attribute *attr, char *buf) 960 { 961 struct s390_idle_data *idle; 962 unsigned long long idle_count; 963 unsigned int sequence; 964 965 idle = &per_cpu(s390_idle, dev->id); 966 repeat: 967 sequence = idle->sequence; 968 smp_rmb(); 969 if (sequence & 1) 970 goto repeat; 971 idle_count = idle->idle_count; 972 if (idle->idle_enter) 973 idle_count++; 974 smp_rmb(); 975 if (idle->sequence != sequence) 976 goto repeat; 977 return sprintf(buf, "%llu\n", idle_count); 978 } 979 static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL); 980 981 static ssize_t show_idle_time(struct sys_device *dev, 982 struct sysdev_attribute *attr, char *buf) 983 { 984 struct s390_idle_data *idle; 985 unsigned long long now, idle_time, idle_enter; 986 unsigned int sequence; 987 988 idle = &per_cpu(s390_idle, dev->id); 989 now = get_clock(); 990 repeat: 991 sequence = idle->sequence; 992 smp_rmb(); 993 if (sequence & 1) 994 goto repeat; 995 idle_time = idle->idle_time; 996 idle_enter = idle->idle_enter; 997 if (idle_enter != 0ULL && idle_enter < now) 998 idle_time += now - idle_enter; 999 smp_rmb(); 1000 if (idle->sequence != sequence) 1001 goto repeat; 1002 return sprintf(buf, "%llu\n", idle_time >> 12); 1003 } 1004 static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL); 1005 1006 static struct attribute *cpu_online_attrs[] = { 1007 &attr_capability.attr, 1008 &attr_idle_count.attr, 1009 &attr_idle_time_us.attr, 1010 NULL, 1011 }; 1012 1013 static struct attribute_group cpu_online_attr_group = { 1014 .attrs = cpu_online_attrs, 1015 }; 1016 1017 static int __cpuinit smp_cpu_notify(struct notifier_block *self, 1018 unsigned long action, void *hcpu) 1019 { 1020 unsigned int cpu = (unsigned int)(long)hcpu; 1021 struct cpu *c = &per_cpu(cpu_devices, cpu); 1022 struct sys_device *s = &c->sysdev; 1023 struct s390_idle_data *idle; 1024 int err = 0; 1025 1026 switch (action) { 1027 case CPU_ONLINE: 1028 case CPU_ONLINE_FROZEN: 1029 idle = &per_cpu(s390_idle, cpu); 1030 memset(idle, 0, sizeof(struct s390_idle_data)); 1031 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 1032 break; 1033 case CPU_DEAD: 1034 case CPU_DEAD_FROZEN: 1035 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 1036 break; 1037 } 1038 return notifier_from_errno(err); 1039 } 1040 1041 static struct notifier_block __cpuinitdata smp_cpu_nb = { 1042 .notifier_call = smp_cpu_notify, 1043 }; 1044 1045 static int __devinit smp_add_present_cpu(int cpu) 1046 { 1047 struct cpu *c = &per_cpu(cpu_devices, cpu); 1048 struct sys_device *s = &c->sysdev; 1049 int rc; 1050 1051 c->hotpluggable = 1; 1052 rc = register_cpu(c, cpu); 1053 if (rc) 1054 goto out; 1055 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group); 1056 if (rc) 1057 goto out_cpu; 1058 if (!cpu_online(cpu)) 1059 goto out; 1060 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 1061 if (!rc) 1062 return 0; 1063 sysfs_remove_group(&s->kobj, &cpu_common_attr_group); 1064 out_cpu: 1065 #ifdef CONFIG_HOTPLUG_CPU 1066 unregister_cpu(c); 1067 #endif 1068 out: 1069 return rc; 1070 } 1071 1072 #ifdef CONFIG_HOTPLUG_CPU 1073 1074 int __ref smp_rescan_cpus(void) 1075 { 1076 cpumask_t newcpus; 1077 int cpu; 1078 int rc; 1079 1080 get_online_cpus(); 1081 mutex_lock(&smp_cpu_state_mutex); 1082 cpumask_copy(&newcpus, cpu_present_mask); 1083 rc = __smp_rescan_cpus(); 1084 if (rc) 1085 goto out; 1086 cpumask_andnot(&newcpus, cpu_present_mask, &newcpus); 1087 for_each_cpu(cpu, &newcpus) { 1088 rc = smp_add_present_cpu(cpu); 1089 if (rc) 1090 set_cpu_present(cpu, false); 1091 } 1092 rc = 0; 1093 out: 1094 mutex_unlock(&smp_cpu_state_mutex); 1095 put_online_cpus(); 1096 if (!cpumask_empty(&newcpus)) 1097 topology_schedule_update(); 1098 return rc; 1099 } 1100 1101 static ssize_t __ref rescan_store(struct sysdev_class *class, 1102 struct sysdev_class_attribute *attr, 1103 const char *buf, 1104 size_t count) 1105 { 1106 int rc; 1107 1108 rc = smp_rescan_cpus(); 1109 return rc ? rc : count; 1110 } 1111 static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store); 1112 #endif /* CONFIG_HOTPLUG_CPU */ 1113 1114 static ssize_t dispatching_show(struct sysdev_class *class, 1115 struct sysdev_class_attribute *attr, 1116 char *buf) 1117 { 1118 ssize_t count; 1119 1120 mutex_lock(&smp_cpu_state_mutex); 1121 count = sprintf(buf, "%d\n", cpu_management); 1122 mutex_unlock(&smp_cpu_state_mutex); 1123 return count; 1124 } 1125 1126 static ssize_t dispatching_store(struct sysdev_class *dev, 1127 struct sysdev_class_attribute *attr, 1128 const char *buf, 1129 size_t count) 1130 { 1131 int val, rc; 1132 char delim; 1133 1134 if (sscanf(buf, "%d %c", &val, &delim) != 1) 1135 return -EINVAL; 1136 if (val != 0 && val != 1) 1137 return -EINVAL; 1138 rc = 0; 1139 get_online_cpus(); 1140 mutex_lock(&smp_cpu_state_mutex); 1141 if (cpu_management == val) 1142 goto out; 1143 rc = topology_set_cpu_management(val); 1144 if (!rc) 1145 cpu_management = val; 1146 out: 1147 mutex_unlock(&smp_cpu_state_mutex); 1148 put_online_cpus(); 1149 return rc ? rc : count; 1150 } 1151 static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show, 1152 dispatching_store); 1153 1154 static int __init topology_init(void) 1155 { 1156 int cpu; 1157 int rc; 1158 1159 register_cpu_notifier(&smp_cpu_nb); 1160 1161 #ifdef CONFIG_HOTPLUG_CPU 1162 rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan); 1163 if (rc) 1164 return rc; 1165 #endif 1166 rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching); 1167 if (rc) 1168 return rc; 1169 for_each_present_cpu(cpu) { 1170 rc = smp_add_present_cpu(cpu); 1171 if (rc) 1172 return rc; 1173 } 1174 return 0; 1175 } 1176 subsys_initcall(topology_init); 1177