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