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/module.h> 27 #include <linux/init.h> 28 #include <linux/mm.h> 29 #include <linux/err.h> 30 #include <linux/spinlock.h> 31 #include <linux/kernel_stat.h> 32 #include <linux/delay.h> 33 #include <linux/cache.h> 34 #include <linux/interrupt.h> 35 #include <linux/irqflags.h> 36 #include <linux/cpu.h> 37 #include <linux/timex.h> 38 #include <linux/bootmem.h> 39 #include <linux/slab.h> 40 #include <asm/asm-offsets.h> 41 #include <asm/ipl.h> 42 #include <asm/setup.h> 43 #include <asm/sigp.h> 44 #include <asm/pgalloc.h> 45 #include <asm/irq.h> 46 #include <asm/s390_ext.h> 47 #include <asm/cpcmd.h> 48 #include <asm/tlbflush.h> 49 #include <asm/timer.h> 50 #include <asm/lowcore.h> 51 #include <asm/sclp.h> 52 #include <asm/cputime.h> 53 #include <asm/vdso.h> 54 #include <asm/cpu.h> 55 #include "entry.h" 56 57 /* logical cpu to cpu address */ 58 unsigned short __cpu_logical_map[NR_CPUS]; 59 60 static struct task_struct *current_set[NR_CPUS]; 61 62 static u8 smp_cpu_type; 63 static int smp_use_sigp_detection; 64 65 enum s390_cpu_state { 66 CPU_STATE_STANDBY, 67 CPU_STATE_CONFIGURED, 68 }; 69 70 DEFINE_MUTEX(smp_cpu_state_mutex); 71 int smp_cpu_polarization[NR_CPUS]; 72 static int smp_cpu_state[NR_CPUS]; 73 static int cpu_management; 74 75 static DEFINE_PER_CPU(struct cpu, cpu_devices); 76 77 static void smp_ext_bitcall(int, int); 78 79 static int raw_cpu_stopped(int cpu) 80 { 81 u32 status; 82 83 switch (raw_sigp_ps(&status, 0, cpu, sigp_sense)) { 84 case sigp_status_stored: 85 /* Check for stopped and check stop state */ 86 if (status & 0x50) 87 return 1; 88 break; 89 default: 90 break; 91 } 92 return 0; 93 } 94 95 static inline int cpu_stopped(int cpu) 96 { 97 return raw_cpu_stopped(cpu_logical_map(cpu)); 98 } 99 100 void smp_switch_to_ipl_cpu(void (*func)(void *), void *data) 101 { 102 struct _lowcore *lc, *current_lc; 103 struct stack_frame *sf; 104 struct pt_regs *regs; 105 unsigned long sp; 106 107 if (smp_processor_id() == 0) 108 func(data); 109 __load_psw_mask(PSW_BASE_BITS | PSW_DEFAULT_KEY); 110 /* Disable lowcore protection */ 111 __ctl_clear_bit(0, 28); 112 current_lc = lowcore_ptr[smp_processor_id()]; 113 lc = lowcore_ptr[0]; 114 if (!lc) 115 lc = current_lc; 116 lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY; 117 lc->restart_psw.addr = PSW_ADDR_AMODE | (unsigned long) smp_restart_cpu; 118 if (!cpu_online(0)) 119 smp_switch_to_cpu(func, data, 0, stap(), __cpu_logical_map[0]); 120 while (sigp(0, sigp_stop_and_store_status) == sigp_busy) 121 cpu_relax(); 122 sp = lc->panic_stack; 123 sp -= sizeof(struct pt_regs); 124 regs = (struct pt_regs *) sp; 125 memcpy(®s->gprs, ¤t_lc->gpregs_save_area, sizeof(regs->gprs)); 126 regs->psw = lc->psw_save_area; 127 sp -= STACK_FRAME_OVERHEAD; 128 sf = (struct stack_frame *) sp; 129 sf->back_chain = regs->gprs[15]; 130 smp_switch_to_cpu(func, data, sp, stap(), __cpu_logical_map[0]); 131 } 132 133 void smp_send_stop(void) 134 { 135 int cpu, rc; 136 137 /* Disable all interrupts/machine checks */ 138 __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK); 139 trace_hardirqs_off(); 140 141 /* stop all processors */ 142 for_each_online_cpu(cpu) { 143 if (cpu == smp_processor_id()) 144 continue; 145 do { 146 rc = sigp(cpu, sigp_stop); 147 } while (rc == sigp_busy); 148 149 while (!cpu_stopped(cpu)) 150 cpu_relax(); 151 } 152 } 153 154 /* 155 * This is the main routine where commands issued by other 156 * cpus are handled. 157 */ 158 159 static void do_ext_call_interrupt(__u16 code) 160 { 161 unsigned long bits; 162 163 /* 164 * handle bit signal external calls 165 * 166 * For the ec_schedule signal we have to do nothing. All the work 167 * is done automatically when we return from the interrupt. 168 */ 169 bits = xchg(&S390_lowcore.ext_call_fast, 0); 170 171 if (test_bit(ec_call_function, &bits)) 172 generic_smp_call_function_interrupt(); 173 174 if (test_bit(ec_call_function_single, &bits)) 175 generic_smp_call_function_single_interrupt(); 176 } 177 178 /* 179 * Send an external call sigp to another cpu and return without waiting 180 * for its completion. 181 */ 182 static void smp_ext_bitcall(int cpu, int sig) 183 { 184 /* 185 * Set signaling bit in lowcore of target cpu and kick it 186 */ 187 set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast); 188 while (sigp(cpu, sigp_emergency_signal) == sigp_busy) 189 udelay(10); 190 } 191 192 void arch_send_call_function_ipi_mask(const struct cpumask *mask) 193 { 194 int cpu; 195 196 for_each_cpu(cpu, mask) 197 smp_ext_bitcall(cpu, ec_call_function); 198 } 199 200 void arch_send_call_function_single_ipi(int cpu) 201 { 202 smp_ext_bitcall(cpu, ec_call_function_single); 203 } 204 205 #ifndef CONFIG_64BIT 206 /* 207 * this function sends a 'purge tlb' signal to another CPU. 208 */ 209 static void smp_ptlb_callback(void *info) 210 { 211 __tlb_flush_local(); 212 } 213 214 void smp_ptlb_all(void) 215 { 216 on_each_cpu(smp_ptlb_callback, NULL, 1); 217 } 218 EXPORT_SYMBOL(smp_ptlb_all); 219 #endif /* ! CONFIG_64BIT */ 220 221 /* 222 * this function sends a 'reschedule' IPI to another CPU. 223 * it goes straight through and wastes no time serializing 224 * anything. Worst case is that we lose a reschedule ... 225 */ 226 void smp_send_reschedule(int cpu) 227 { 228 smp_ext_bitcall(cpu, ec_schedule); 229 } 230 231 /* 232 * parameter area for the set/clear control bit callbacks 233 */ 234 struct ec_creg_mask_parms { 235 unsigned long orvals[16]; 236 unsigned long andvals[16]; 237 }; 238 239 /* 240 * callback for setting/clearing control bits 241 */ 242 static void smp_ctl_bit_callback(void *info) 243 { 244 struct ec_creg_mask_parms *pp = info; 245 unsigned long cregs[16]; 246 int i; 247 248 __ctl_store(cregs, 0, 15); 249 for (i = 0; i <= 15; i++) 250 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i]; 251 __ctl_load(cregs, 0, 15); 252 } 253 254 /* 255 * Set a bit in a control register of all cpus 256 */ 257 void smp_ctl_set_bit(int cr, int bit) 258 { 259 struct ec_creg_mask_parms parms; 260 261 memset(&parms.orvals, 0, sizeof(parms.orvals)); 262 memset(&parms.andvals, 0xff, sizeof(parms.andvals)); 263 parms.orvals[cr] = 1 << bit; 264 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 265 } 266 EXPORT_SYMBOL(smp_ctl_set_bit); 267 268 /* 269 * Clear a bit in a control register of all cpus 270 */ 271 void smp_ctl_clear_bit(int cr, int bit) 272 { 273 struct ec_creg_mask_parms parms; 274 275 memset(&parms.orvals, 0, sizeof(parms.orvals)); 276 memset(&parms.andvals, 0xff, sizeof(parms.andvals)); 277 parms.andvals[cr] = ~(1L << bit); 278 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 279 } 280 EXPORT_SYMBOL(smp_ctl_clear_bit); 281 282 #ifdef CONFIG_ZFCPDUMP 283 284 static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) 285 { 286 if (ipl_info.type != IPL_TYPE_FCP_DUMP) 287 return; 288 if (cpu >= NR_CPUS) { 289 pr_warning("CPU %i exceeds the maximum %i and is excluded from " 290 "the dump\n", cpu, NR_CPUS - 1); 291 return; 292 } 293 zfcpdump_save_areas[cpu] = kmalloc(sizeof(struct save_area), GFP_KERNEL); 294 while (raw_sigp(phy_cpu, sigp_stop_and_store_status) == sigp_busy) 295 cpu_relax(); 296 memcpy_real(zfcpdump_save_areas[cpu], 297 (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE, 298 sizeof(struct save_area)); 299 } 300 301 struct save_area *zfcpdump_save_areas[NR_CPUS + 1]; 302 EXPORT_SYMBOL_GPL(zfcpdump_save_areas); 303 304 #else 305 306 static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { } 307 308 #endif /* CONFIG_ZFCPDUMP */ 309 310 static int cpu_known(int cpu_id) 311 { 312 int cpu; 313 314 for_each_present_cpu(cpu) { 315 if (__cpu_logical_map[cpu] == cpu_id) 316 return 1; 317 } 318 return 0; 319 } 320 321 static int smp_rescan_cpus_sigp(cpumask_t avail) 322 { 323 int cpu_id, logical_cpu; 324 325 logical_cpu = cpumask_first(&avail); 326 if (logical_cpu >= nr_cpu_ids) 327 return 0; 328 for (cpu_id = 0; cpu_id <= MAX_CPU_ADDRESS; cpu_id++) { 329 if (cpu_known(cpu_id)) 330 continue; 331 __cpu_logical_map[logical_cpu] = cpu_id; 332 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN; 333 if (!cpu_stopped(logical_cpu)) 334 continue; 335 cpu_set(logical_cpu, cpu_present_map); 336 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED; 337 logical_cpu = cpumask_next(logical_cpu, &avail); 338 if (logical_cpu >= nr_cpu_ids) 339 break; 340 } 341 return 0; 342 } 343 344 static int smp_rescan_cpus_sclp(cpumask_t avail) 345 { 346 struct sclp_cpu_info *info; 347 int cpu_id, logical_cpu, cpu; 348 int rc; 349 350 logical_cpu = cpumask_first(&avail); 351 if (logical_cpu >= nr_cpu_ids) 352 return 0; 353 info = kmalloc(sizeof(*info), GFP_KERNEL); 354 if (!info) 355 return -ENOMEM; 356 rc = sclp_get_cpu_info(info); 357 if (rc) 358 goto out; 359 for (cpu = 0; cpu < info->combined; cpu++) { 360 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type) 361 continue; 362 cpu_id = info->cpu[cpu].address; 363 if (cpu_known(cpu_id)) 364 continue; 365 __cpu_logical_map[logical_cpu] = cpu_id; 366 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN; 367 cpu_set(logical_cpu, cpu_present_map); 368 if (cpu >= info->configured) 369 smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY; 370 else 371 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED; 372 logical_cpu = cpumask_next(logical_cpu, &avail); 373 if (logical_cpu >= nr_cpu_ids) 374 break; 375 } 376 out: 377 kfree(info); 378 return rc; 379 } 380 381 static int __smp_rescan_cpus(void) 382 { 383 cpumask_t avail; 384 385 cpus_xor(avail, cpu_possible_map, cpu_present_map); 386 if (smp_use_sigp_detection) 387 return smp_rescan_cpus_sigp(avail); 388 else 389 return smp_rescan_cpus_sclp(avail); 390 } 391 392 static void __init smp_detect_cpus(void) 393 { 394 unsigned int cpu, c_cpus, s_cpus; 395 struct sclp_cpu_info *info; 396 u16 boot_cpu_addr, cpu_addr; 397 398 c_cpus = 1; 399 s_cpus = 0; 400 boot_cpu_addr = __cpu_logical_map[0]; 401 info = kmalloc(sizeof(*info), GFP_KERNEL); 402 if (!info) 403 panic("smp_detect_cpus failed to allocate memory\n"); 404 /* Use sigp detection algorithm if sclp doesn't work. */ 405 if (sclp_get_cpu_info(info)) { 406 smp_use_sigp_detection = 1; 407 for (cpu = 0; cpu <= MAX_CPU_ADDRESS; cpu++) { 408 if (cpu == boot_cpu_addr) 409 continue; 410 if (!raw_cpu_stopped(cpu)) 411 continue; 412 smp_get_save_area(c_cpus, cpu); 413 c_cpus++; 414 } 415 goto out; 416 } 417 418 if (info->has_cpu_type) { 419 for (cpu = 0; cpu < info->combined; cpu++) { 420 if (info->cpu[cpu].address == boot_cpu_addr) { 421 smp_cpu_type = info->cpu[cpu].type; 422 break; 423 } 424 } 425 } 426 427 for (cpu = 0; cpu < info->combined; cpu++) { 428 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type) 429 continue; 430 cpu_addr = info->cpu[cpu].address; 431 if (cpu_addr == boot_cpu_addr) 432 continue; 433 if (!raw_cpu_stopped(cpu_addr)) { 434 s_cpus++; 435 continue; 436 } 437 smp_get_save_area(c_cpus, cpu_addr); 438 c_cpus++; 439 } 440 out: 441 kfree(info); 442 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus); 443 get_online_cpus(); 444 __smp_rescan_cpus(); 445 put_online_cpus(); 446 } 447 448 /* 449 * Activate a secondary processor. 450 */ 451 int __cpuinit start_secondary(void *cpuvoid) 452 { 453 /* Setup the cpu */ 454 cpu_init(); 455 preempt_disable(); 456 /* Enable TOD clock interrupts on the secondary cpu. */ 457 init_cpu_timer(); 458 /* Enable cpu timer interrupts on the secondary cpu. */ 459 init_cpu_vtimer(); 460 /* Enable pfault pseudo page faults on this cpu. */ 461 pfault_init(); 462 463 /* call cpu notifiers */ 464 notify_cpu_starting(smp_processor_id()); 465 /* Mark this cpu as online */ 466 ipi_call_lock(); 467 cpu_set(smp_processor_id(), cpu_online_map); 468 ipi_call_unlock(); 469 /* Switch on interrupts */ 470 local_irq_enable(); 471 /* Print info about this processor */ 472 print_cpu_info(); 473 /* cpu_idle will call schedule for us */ 474 cpu_idle(); 475 return 0; 476 } 477 478 static void __init smp_create_idle(unsigned int cpu) 479 { 480 struct task_struct *p; 481 482 /* 483 * don't care about the psw and regs settings since we'll never 484 * reschedule the forked task. 485 */ 486 p = fork_idle(cpu); 487 if (IS_ERR(p)) 488 panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p)); 489 current_set[cpu] = p; 490 } 491 492 static int __cpuinit smp_alloc_lowcore(int cpu) 493 { 494 unsigned long async_stack, panic_stack; 495 struct _lowcore *lowcore; 496 497 lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); 498 if (!lowcore) 499 return -ENOMEM; 500 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER); 501 panic_stack = __get_free_page(GFP_KERNEL); 502 if (!panic_stack || !async_stack) 503 goto out; 504 memcpy(lowcore, &S390_lowcore, 512); 505 memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512); 506 lowcore->async_stack = async_stack + ASYNC_SIZE; 507 lowcore->panic_stack = panic_stack + PAGE_SIZE; 508 509 #ifndef CONFIG_64BIT 510 if (MACHINE_HAS_IEEE) { 511 unsigned long save_area; 512 513 save_area = get_zeroed_page(GFP_KERNEL); 514 if (!save_area) 515 goto out; 516 lowcore->extended_save_area_addr = (u32) save_area; 517 } 518 #else 519 if (vdso_alloc_per_cpu(cpu, lowcore)) 520 goto out; 521 #endif 522 lowcore_ptr[cpu] = lowcore; 523 return 0; 524 525 out: 526 free_page(panic_stack); 527 free_pages(async_stack, ASYNC_ORDER); 528 free_pages((unsigned long) lowcore, LC_ORDER); 529 return -ENOMEM; 530 } 531 532 static void smp_free_lowcore(int cpu) 533 { 534 struct _lowcore *lowcore; 535 536 lowcore = lowcore_ptr[cpu]; 537 #ifndef CONFIG_64BIT 538 if (MACHINE_HAS_IEEE) 539 free_page((unsigned long) lowcore->extended_save_area_addr); 540 #else 541 vdso_free_per_cpu(cpu, lowcore); 542 #endif 543 free_page(lowcore->panic_stack - PAGE_SIZE); 544 free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER); 545 free_pages((unsigned long) lowcore, LC_ORDER); 546 lowcore_ptr[cpu] = NULL; 547 } 548 549 /* Upping and downing of CPUs */ 550 int __cpuinit __cpu_up(unsigned int cpu) 551 { 552 struct _lowcore *cpu_lowcore; 553 struct task_struct *idle; 554 struct stack_frame *sf; 555 u32 lowcore; 556 int ccode; 557 558 if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED) 559 return -EIO; 560 if (smp_alloc_lowcore(cpu)) 561 return -ENOMEM; 562 do { 563 ccode = sigp(cpu, sigp_initial_cpu_reset); 564 if (ccode == sigp_busy) 565 udelay(10); 566 if (ccode == sigp_not_operational) 567 goto err_out; 568 } while (ccode == sigp_busy); 569 570 lowcore = (u32)(unsigned long)lowcore_ptr[cpu]; 571 while (sigp_p(lowcore, cpu, sigp_set_prefix) == sigp_busy) 572 udelay(10); 573 574 idle = current_set[cpu]; 575 cpu_lowcore = lowcore_ptr[cpu]; 576 cpu_lowcore->kernel_stack = (unsigned long) 577 task_stack_page(idle) + THREAD_SIZE; 578 cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle); 579 sf = (struct stack_frame *) (cpu_lowcore->kernel_stack 580 - sizeof(struct pt_regs) 581 - sizeof(struct stack_frame)); 582 memset(sf, 0, sizeof(struct stack_frame)); 583 sf->gprs[9] = (unsigned long) sf; 584 cpu_lowcore->save_area[15] = (unsigned long) sf; 585 __ctl_store(cpu_lowcore->cregs_save_area, 0, 15); 586 atomic_inc(&init_mm.context.attach_count); 587 asm volatile( 588 " stam 0,15,0(%0)" 589 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory"); 590 cpu_lowcore->percpu_offset = __per_cpu_offset[cpu]; 591 cpu_lowcore->current_task = (unsigned long) idle; 592 cpu_lowcore->cpu_nr = cpu; 593 cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce; 594 cpu_lowcore->machine_flags = S390_lowcore.machine_flags; 595 cpu_lowcore->ftrace_func = S390_lowcore.ftrace_func; 596 eieio(); 597 598 while (sigp(cpu, sigp_restart) == sigp_busy) 599 udelay(10); 600 601 while (!cpu_online(cpu)) 602 cpu_relax(); 603 return 0; 604 605 err_out: 606 smp_free_lowcore(cpu); 607 return -EIO; 608 } 609 610 static int __init setup_possible_cpus(char *s) 611 { 612 int pcpus, cpu; 613 614 pcpus = simple_strtoul(s, NULL, 0); 615 init_cpu_possible(cpumask_of(0)); 616 for (cpu = 1; cpu < pcpus && cpu < nr_cpu_ids; cpu++) 617 set_cpu_possible(cpu, true); 618 return 0; 619 } 620 early_param("possible_cpus", setup_possible_cpus); 621 622 #ifdef CONFIG_HOTPLUG_CPU 623 624 int __cpu_disable(void) 625 { 626 struct ec_creg_mask_parms cr_parms; 627 int cpu = smp_processor_id(); 628 629 cpu_clear(cpu, cpu_online_map); 630 631 /* Disable pfault pseudo page faults on this cpu. */ 632 pfault_fini(); 633 634 memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals)); 635 memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals)); 636 637 /* disable all external interrupts */ 638 cr_parms.orvals[0] = 0; 639 cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 12 | 640 1 << 11 | 1 << 10 | 1 << 6 | 1 << 4); 641 /* disable all I/O interrupts */ 642 cr_parms.orvals[6] = 0; 643 cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 | 644 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24); 645 /* disable most machine checks */ 646 cr_parms.orvals[14] = 0; 647 cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 | 648 1 << 25 | 1 << 24); 649 650 smp_ctl_bit_callback(&cr_parms); 651 652 return 0; 653 } 654 655 void __cpu_die(unsigned int cpu) 656 { 657 /* Wait until target cpu is down */ 658 while (!cpu_stopped(cpu)) 659 cpu_relax(); 660 while (sigp_p(0, cpu, sigp_set_prefix) == sigp_busy) 661 udelay(10); 662 smp_free_lowcore(cpu); 663 atomic_dec(&init_mm.context.attach_count); 664 pr_info("Processor %d stopped\n", cpu); 665 } 666 667 void cpu_die(void) 668 { 669 idle_task_exit(); 670 while (sigp(smp_processor_id(), sigp_stop) == sigp_busy) 671 cpu_relax(); 672 for (;;); 673 } 674 675 #endif /* CONFIG_HOTPLUG_CPU */ 676 677 void __init smp_prepare_cpus(unsigned int max_cpus) 678 { 679 #ifndef CONFIG_64BIT 680 unsigned long save_area = 0; 681 #endif 682 unsigned long async_stack, panic_stack; 683 struct _lowcore *lowcore; 684 unsigned int cpu; 685 686 smp_detect_cpus(); 687 688 /* request the 0x1201 emergency signal external interrupt */ 689 if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0) 690 panic("Couldn't request external interrupt 0x1201"); 691 print_cpu_info(); 692 693 /* Reallocate current lowcore, but keep its contents. */ 694 lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); 695 panic_stack = __get_free_page(GFP_KERNEL); 696 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER); 697 BUG_ON(!lowcore || !panic_stack || !async_stack); 698 #ifndef CONFIG_64BIT 699 if (MACHINE_HAS_IEEE) 700 save_area = get_zeroed_page(GFP_KERNEL); 701 #endif 702 local_irq_disable(); 703 local_mcck_disable(); 704 lowcore_ptr[smp_processor_id()] = lowcore; 705 *lowcore = S390_lowcore; 706 lowcore->panic_stack = panic_stack + PAGE_SIZE; 707 lowcore->async_stack = async_stack + ASYNC_SIZE; 708 #ifndef CONFIG_64BIT 709 if (MACHINE_HAS_IEEE) 710 lowcore->extended_save_area_addr = (u32) save_area; 711 #endif 712 set_prefix((u32)(unsigned long) lowcore); 713 local_mcck_enable(); 714 local_irq_enable(); 715 #ifdef CONFIG_64BIT 716 if (vdso_alloc_per_cpu(smp_processor_id(), &S390_lowcore)) 717 BUG(); 718 #endif 719 for_each_possible_cpu(cpu) 720 if (cpu != smp_processor_id()) 721 smp_create_idle(cpu); 722 } 723 724 void __init smp_prepare_boot_cpu(void) 725 { 726 BUG_ON(smp_processor_id() != 0); 727 728 current_thread_info()->cpu = 0; 729 cpu_set(0, cpu_present_map); 730 cpu_set(0, cpu_online_map); 731 S390_lowcore.percpu_offset = __per_cpu_offset[0]; 732 current_set[0] = current; 733 smp_cpu_state[0] = CPU_STATE_CONFIGURED; 734 smp_cpu_polarization[0] = POLARIZATION_UNKNWN; 735 } 736 737 void __init smp_cpus_done(unsigned int max_cpus) 738 { 739 } 740 741 void __init smp_setup_processor_id(void) 742 { 743 S390_lowcore.cpu_nr = 0; 744 __cpu_logical_map[0] = stap(); 745 } 746 747 /* 748 * the frequency of the profiling timer can be changed 749 * by writing a multiplier value into /proc/profile. 750 * 751 * usually you want to run this on all CPUs ;) 752 */ 753 int setup_profiling_timer(unsigned int multiplier) 754 { 755 return 0; 756 } 757 758 #ifdef CONFIG_HOTPLUG_CPU 759 static ssize_t cpu_configure_show(struct sys_device *dev, 760 struct sysdev_attribute *attr, char *buf) 761 { 762 ssize_t count; 763 764 mutex_lock(&smp_cpu_state_mutex); 765 count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]); 766 mutex_unlock(&smp_cpu_state_mutex); 767 return count; 768 } 769 770 static ssize_t cpu_configure_store(struct sys_device *dev, 771 struct sysdev_attribute *attr, 772 const char *buf, size_t count) 773 { 774 int cpu = dev->id; 775 int val, rc; 776 char delim; 777 778 if (sscanf(buf, "%d %c", &val, &delim) != 1) 779 return -EINVAL; 780 if (val != 0 && val != 1) 781 return -EINVAL; 782 783 get_online_cpus(); 784 mutex_lock(&smp_cpu_state_mutex); 785 rc = -EBUSY; 786 /* disallow configuration changes of online cpus and cpu 0 */ 787 if (cpu_online(cpu) || cpu == 0) 788 goto out; 789 rc = 0; 790 switch (val) { 791 case 0: 792 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) { 793 rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]); 794 if (!rc) { 795 smp_cpu_state[cpu] = CPU_STATE_STANDBY; 796 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN; 797 } 798 } 799 break; 800 case 1: 801 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) { 802 rc = sclp_cpu_configure(__cpu_logical_map[cpu]); 803 if (!rc) { 804 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED; 805 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN; 806 } 807 } 808 break; 809 default: 810 break; 811 } 812 out: 813 mutex_unlock(&smp_cpu_state_mutex); 814 put_online_cpus(); 815 return rc ? rc : count; 816 } 817 static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store); 818 #endif /* CONFIG_HOTPLUG_CPU */ 819 820 static ssize_t cpu_polarization_show(struct sys_device *dev, 821 struct sysdev_attribute *attr, char *buf) 822 { 823 int cpu = dev->id; 824 ssize_t count; 825 826 mutex_lock(&smp_cpu_state_mutex); 827 switch (smp_cpu_polarization[cpu]) { 828 case POLARIZATION_HRZ: 829 count = sprintf(buf, "horizontal\n"); 830 break; 831 case POLARIZATION_VL: 832 count = sprintf(buf, "vertical:low\n"); 833 break; 834 case POLARIZATION_VM: 835 count = sprintf(buf, "vertical:medium\n"); 836 break; 837 case POLARIZATION_VH: 838 count = sprintf(buf, "vertical:high\n"); 839 break; 840 default: 841 count = sprintf(buf, "unknown\n"); 842 break; 843 } 844 mutex_unlock(&smp_cpu_state_mutex); 845 return count; 846 } 847 static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL); 848 849 static ssize_t show_cpu_address(struct sys_device *dev, 850 struct sysdev_attribute *attr, char *buf) 851 { 852 return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]); 853 } 854 static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL); 855 856 857 static struct attribute *cpu_common_attrs[] = { 858 #ifdef CONFIG_HOTPLUG_CPU 859 &attr_configure.attr, 860 #endif 861 &attr_address.attr, 862 &attr_polarization.attr, 863 NULL, 864 }; 865 866 static struct attribute_group cpu_common_attr_group = { 867 .attrs = cpu_common_attrs, 868 }; 869 870 static ssize_t show_capability(struct sys_device *dev, 871 struct sysdev_attribute *attr, char *buf) 872 { 873 unsigned int capability; 874 int rc; 875 876 rc = get_cpu_capability(&capability); 877 if (rc) 878 return rc; 879 return sprintf(buf, "%u\n", capability); 880 } 881 static SYSDEV_ATTR(capability, 0444, show_capability, NULL); 882 883 static ssize_t show_idle_count(struct sys_device *dev, 884 struct sysdev_attribute *attr, char *buf) 885 { 886 struct s390_idle_data *idle; 887 unsigned long long idle_count; 888 unsigned int sequence; 889 890 idle = &per_cpu(s390_idle, dev->id); 891 repeat: 892 sequence = idle->sequence; 893 smp_rmb(); 894 if (sequence & 1) 895 goto repeat; 896 idle_count = idle->idle_count; 897 if (idle->idle_enter) 898 idle_count++; 899 smp_rmb(); 900 if (idle->sequence != sequence) 901 goto repeat; 902 return sprintf(buf, "%llu\n", idle_count); 903 } 904 static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL); 905 906 static ssize_t show_idle_time(struct sys_device *dev, 907 struct sysdev_attribute *attr, char *buf) 908 { 909 struct s390_idle_data *idle; 910 unsigned long long now, idle_time, idle_enter; 911 unsigned int sequence; 912 913 idle = &per_cpu(s390_idle, dev->id); 914 now = get_clock(); 915 repeat: 916 sequence = idle->sequence; 917 smp_rmb(); 918 if (sequence & 1) 919 goto repeat; 920 idle_time = idle->idle_time; 921 idle_enter = idle->idle_enter; 922 if (idle_enter != 0ULL && idle_enter < now) 923 idle_time += now - idle_enter; 924 smp_rmb(); 925 if (idle->sequence != sequence) 926 goto repeat; 927 return sprintf(buf, "%llu\n", idle_time >> 12); 928 } 929 static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL); 930 931 static struct attribute *cpu_online_attrs[] = { 932 &attr_capability.attr, 933 &attr_idle_count.attr, 934 &attr_idle_time_us.attr, 935 NULL, 936 }; 937 938 static struct attribute_group cpu_online_attr_group = { 939 .attrs = cpu_online_attrs, 940 }; 941 942 static int __cpuinit smp_cpu_notify(struct notifier_block *self, 943 unsigned long action, void *hcpu) 944 { 945 unsigned int cpu = (unsigned int)(long)hcpu; 946 struct cpu *c = &per_cpu(cpu_devices, cpu); 947 struct sys_device *s = &c->sysdev; 948 struct s390_idle_data *idle; 949 int err = 0; 950 951 switch (action) { 952 case CPU_ONLINE: 953 case CPU_ONLINE_FROZEN: 954 idle = &per_cpu(s390_idle, cpu); 955 memset(idle, 0, sizeof(struct s390_idle_data)); 956 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 957 break; 958 case CPU_DEAD: 959 case CPU_DEAD_FROZEN: 960 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 961 break; 962 } 963 return notifier_from_errno(err); 964 } 965 966 static struct notifier_block __cpuinitdata smp_cpu_nb = { 967 .notifier_call = smp_cpu_notify, 968 }; 969 970 static int __devinit smp_add_present_cpu(int cpu) 971 { 972 struct cpu *c = &per_cpu(cpu_devices, cpu); 973 struct sys_device *s = &c->sysdev; 974 int rc; 975 976 c->hotpluggable = 1; 977 rc = register_cpu(c, cpu); 978 if (rc) 979 goto out; 980 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group); 981 if (rc) 982 goto out_cpu; 983 if (!cpu_online(cpu)) 984 goto out; 985 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 986 if (!rc) 987 return 0; 988 sysfs_remove_group(&s->kobj, &cpu_common_attr_group); 989 out_cpu: 990 #ifdef CONFIG_HOTPLUG_CPU 991 unregister_cpu(c); 992 #endif 993 out: 994 return rc; 995 } 996 997 #ifdef CONFIG_HOTPLUG_CPU 998 999 int __ref smp_rescan_cpus(void) 1000 { 1001 cpumask_t newcpus; 1002 int cpu; 1003 int rc; 1004 1005 get_online_cpus(); 1006 mutex_lock(&smp_cpu_state_mutex); 1007 newcpus = cpu_present_map; 1008 rc = __smp_rescan_cpus(); 1009 if (rc) 1010 goto out; 1011 cpus_andnot(newcpus, cpu_present_map, newcpus); 1012 for_each_cpu_mask(cpu, newcpus) { 1013 rc = smp_add_present_cpu(cpu); 1014 if (rc) 1015 cpu_clear(cpu, cpu_present_map); 1016 } 1017 rc = 0; 1018 out: 1019 mutex_unlock(&smp_cpu_state_mutex); 1020 put_online_cpus(); 1021 if (!cpus_empty(newcpus)) 1022 topology_schedule_update(); 1023 return rc; 1024 } 1025 1026 static ssize_t __ref rescan_store(struct sysdev_class *class, 1027 struct sysdev_class_attribute *attr, 1028 const char *buf, 1029 size_t count) 1030 { 1031 int rc; 1032 1033 rc = smp_rescan_cpus(); 1034 return rc ? rc : count; 1035 } 1036 static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store); 1037 #endif /* CONFIG_HOTPLUG_CPU */ 1038 1039 static ssize_t dispatching_show(struct sysdev_class *class, 1040 struct sysdev_class_attribute *attr, 1041 char *buf) 1042 { 1043 ssize_t count; 1044 1045 mutex_lock(&smp_cpu_state_mutex); 1046 count = sprintf(buf, "%d\n", cpu_management); 1047 mutex_unlock(&smp_cpu_state_mutex); 1048 return count; 1049 } 1050 1051 static ssize_t dispatching_store(struct sysdev_class *dev, 1052 struct sysdev_class_attribute *attr, 1053 const char *buf, 1054 size_t count) 1055 { 1056 int val, rc; 1057 char delim; 1058 1059 if (sscanf(buf, "%d %c", &val, &delim) != 1) 1060 return -EINVAL; 1061 if (val != 0 && val != 1) 1062 return -EINVAL; 1063 rc = 0; 1064 get_online_cpus(); 1065 mutex_lock(&smp_cpu_state_mutex); 1066 if (cpu_management == val) 1067 goto out; 1068 rc = topology_set_cpu_management(val); 1069 if (!rc) 1070 cpu_management = val; 1071 out: 1072 mutex_unlock(&smp_cpu_state_mutex); 1073 put_online_cpus(); 1074 return rc ? rc : count; 1075 } 1076 static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show, 1077 dispatching_store); 1078 1079 static int __init topology_init(void) 1080 { 1081 int cpu; 1082 int rc; 1083 1084 register_cpu_notifier(&smp_cpu_nb); 1085 1086 #ifdef CONFIG_HOTPLUG_CPU 1087 rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan); 1088 if (rc) 1089 return rc; 1090 #endif 1091 rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching); 1092 if (rc) 1093 return rc; 1094 for_each_present_cpu(cpu) { 1095 rc = smp_add_present_cpu(cpu); 1096 if (rc) 1097 return rc; 1098 } 1099 return 0; 1100 } 1101 subsys_initcall(topology_init); 1102