1 /* 2 * SMP related functions 3 * 4 * Copyright IBM Corp. 1999, 2012 5 * Author(s): Denis Joseph Barrow, 6 * Martin Schwidefsky <schwidefsky@de.ibm.com>, 7 * Heiko Carstens <heiko.carstens@de.ibm.com>, 8 * 9 * based on other smp stuff by 10 * (c) 1995 Alan Cox, CymruNET Ltd <alan@cymru.net> 11 * (c) 1998 Ingo Molnar 12 * 13 * The code outside of smp.c uses logical cpu numbers, only smp.c does 14 * the translation of logical to physical cpu ids. All new code that 15 * operates on physical cpu numbers needs to go into smp.c. 16 */ 17 18 #define KMSG_COMPONENT "cpu" 19 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 20 21 #include <linux/workqueue.h> 22 #include <linux/bootmem.h> 23 #include <linux/export.h> 24 #include <linux/init.h> 25 #include <linux/mm.h> 26 #include <linux/err.h> 27 #include <linux/spinlock.h> 28 #include <linux/kernel_stat.h> 29 #include <linux/delay.h> 30 #include <linux/interrupt.h> 31 #include <linux/irqflags.h> 32 #include <linux/cpu.h> 33 #include <linux/slab.h> 34 #include <linux/crash_dump.h> 35 #include <linux/memblock.h> 36 #include <asm/asm-offsets.h> 37 #include <asm/diag.h> 38 #include <asm/switch_to.h> 39 #include <asm/facility.h> 40 #include <asm/ipl.h> 41 #include <asm/setup.h> 42 #include <asm/irq.h> 43 #include <asm/tlbflush.h> 44 #include <asm/vtimer.h> 45 #include <asm/lowcore.h> 46 #include <asm/sclp.h> 47 #include <asm/vdso.h> 48 #include <asm/debug.h> 49 #include <asm/os_info.h> 50 #include <asm/sigp.h> 51 #include <asm/idle.h> 52 #include "entry.h" 53 54 enum { 55 ec_schedule = 0, 56 ec_call_function_single, 57 ec_stop_cpu, 58 }; 59 60 enum { 61 CPU_STATE_STANDBY, 62 CPU_STATE_CONFIGURED, 63 }; 64 65 static DEFINE_PER_CPU(struct cpu *, cpu_device); 66 67 struct pcpu { 68 struct lowcore *lowcore; /* lowcore page(s) for the cpu */ 69 unsigned long ec_mask; /* bit mask for ec_xxx functions */ 70 unsigned long ec_clk; /* sigp timestamp for ec_xxx */ 71 signed char state; /* physical cpu state */ 72 signed char polarization; /* physical polarization */ 73 u16 address; /* physical cpu address */ 74 }; 75 76 static u8 boot_core_type; 77 static struct pcpu pcpu_devices[NR_CPUS]; 78 79 unsigned int smp_cpu_mt_shift; 80 EXPORT_SYMBOL(smp_cpu_mt_shift); 81 82 unsigned int smp_cpu_mtid; 83 EXPORT_SYMBOL(smp_cpu_mtid); 84 85 #ifdef CONFIG_CRASH_DUMP 86 __vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS]; 87 #endif 88 89 static unsigned int smp_max_threads __initdata = -1U; 90 91 static int __init early_nosmt(char *s) 92 { 93 smp_max_threads = 1; 94 return 0; 95 } 96 early_param("nosmt", early_nosmt); 97 98 static int __init early_smt(char *s) 99 { 100 get_option(&s, &smp_max_threads); 101 return 0; 102 } 103 early_param("smt", early_smt); 104 105 /* 106 * The smp_cpu_state_mutex must be held when changing the state or polarization 107 * member of a pcpu data structure within the pcpu_devices arreay. 108 */ 109 DEFINE_MUTEX(smp_cpu_state_mutex); 110 111 /* 112 * Signal processor helper functions. 113 */ 114 static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm) 115 { 116 int cc; 117 118 while (1) { 119 cc = __pcpu_sigp(addr, order, parm, NULL); 120 if (cc != SIGP_CC_BUSY) 121 return cc; 122 cpu_relax(); 123 } 124 } 125 126 static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm) 127 { 128 int cc, retry; 129 130 for (retry = 0; ; retry++) { 131 cc = __pcpu_sigp(pcpu->address, order, parm, NULL); 132 if (cc != SIGP_CC_BUSY) 133 break; 134 if (retry >= 3) 135 udelay(10); 136 } 137 return cc; 138 } 139 140 static inline int pcpu_stopped(struct pcpu *pcpu) 141 { 142 u32 uninitialized_var(status); 143 144 if (__pcpu_sigp(pcpu->address, SIGP_SENSE, 145 0, &status) != SIGP_CC_STATUS_STORED) 146 return 0; 147 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED)); 148 } 149 150 static inline int pcpu_running(struct pcpu *pcpu) 151 { 152 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING, 153 0, NULL) != SIGP_CC_STATUS_STORED) 154 return 1; 155 /* Status stored condition code is equivalent to cpu not running. */ 156 return 0; 157 } 158 159 /* 160 * Find struct pcpu by cpu address. 161 */ 162 static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address) 163 { 164 int cpu; 165 166 for_each_cpu(cpu, mask) 167 if (pcpu_devices[cpu].address == address) 168 return pcpu_devices + cpu; 169 return NULL; 170 } 171 172 static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit) 173 { 174 int order; 175 176 if (test_and_set_bit(ec_bit, &pcpu->ec_mask)) 177 return; 178 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL; 179 pcpu->ec_clk = get_tod_clock_fast(); 180 pcpu_sigp_retry(pcpu, order, 0); 181 } 182 183 #define ASYNC_FRAME_OFFSET (ASYNC_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE) 184 #define PANIC_FRAME_OFFSET (PAGE_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE) 185 186 static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu) 187 { 188 unsigned long async_stack, panic_stack; 189 struct lowcore *lc; 190 191 if (pcpu != &pcpu_devices[0]) { 192 pcpu->lowcore = (struct lowcore *) 193 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); 194 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER); 195 panic_stack = __get_free_page(GFP_KERNEL); 196 if (!pcpu->lowcore || !panic_stack || !async_stack) 197 goto out; 198 } else { 199 async_stack = pcpu->lowcore->async_stack - ASYNC_FRAME_OFFSET; 200 panic_stack = pcpu->lowcore->panic_stack - PANIC_FRAME_OFFSET; 201 } 202 lc = pcpu->lowcore; 203 memcpy(lc, &S390_lowcore, 512); 204 memset((char *) lc + 512, 0, sizeof(*lc) - 512); 205 lc->async_stack = async_stack + ASYNC_FRAME_OFFSET; 206 lc->panic_stack = panic_stack + PANIC_FRAME_OFFSET; 207 lc->cpu_nr = cpu; 208 lc->spinlock_lockval = arch_spin_lockval(cpu); 209 if (MACHINE_HAS_VX) 210 lc->vector_save_area_addr = 211 (unsigned long) &lc->vector_save_area; 212 if (vdso_alloc_per_cpu(lc)) 213 goto out; 214 lowcore_ptr[cpu] = lc; 215 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc); 216 return 0; 217 out: 218 if (pcpu != &pcpu_devices[0]) { 219 free_page(panic_stack); 220 free_pages(async_stack, ASYNC_ORDER); 221 free_pages((unsigned long) pcpu->lowcore, LC_ORDER); 222 } 223 return -ENOMEM; 224 } 225 226 #ifdef CONFIG_HOTPLUG_CPU 227 228 static void pcpu_free_lowcore(struct pcpu *pcpu) 229 { 230 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0); 231 lowcore_ptr[pcpu - pcpu_devices] = NULL; 232 vdso_free_per_cpu(pcpu->lowcore); 233 if (pcpu == &pcpu_devices[0]) 234 return; 235 free_page(pcpu->lowcore->panic_stack-PANIC_FRAME_OFFSET); 236 free_pages(pcpu->lowcore->async_stack-ASYNC_FRAME_OFFSET, ASYNC_ORDER); 237 free_pages((unsigned long) pcpu->lowcore, LC_ORDER); 238 } 239 240 #endif /* CONFIG_HOTPLUG_CPU */ 241 242 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu) 243 { 244 struct lowcore *lc = pcpu->lowcore; 245 246 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask); 247 cpumask_set_cpu(cpu, mm_cpumask(&init_mm)); 248 lc->cpu_nr = cpu; 249 lc->spinlock_lockval = arch_spin_lockval(cpu); 250 lc->percpu_offset = __per_cpu_offset[cpu]; 251 lc->kernel_asce = S390_lowcore.kernel_asce; 252 lc->machine_flags = S390_lowcore.machine_flags; 253 lc->user_timer = lc->system_timer = lc->steal_timer = 0; 254 __ctl_store(lc->cregs_save_area, 0, 15); 255 save_access_regs((unsigned int *) lc->access_regs_save_area); 256 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list, 257 MAX_FACILITY_BIT/8); 258 } 259 260 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk) 261 { 262 struct lowcore *lc = pcpu->lowcore; 263 264 lc->kernel_stack = (unsigned long) task_stack_page(tsk) 265 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); 266 lc->current_task = (unsigned long) tsk; 267 lc->lpp = LPP_MAGIC; 268 lc->current_pid = tsk->pid; 269 lc->user_timer = tsk->thread.user_timer; 270 lc->system_timer = tsk->thread.system_timer; 271 lc->steal_timer = 0; 272 } 273 274 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data) 275 { 276 struct lowcore *lc = pcpu->lowcore; 277 278 lc->restart_stack = lc->kernel_stack; 279 lc->restart_fn = (unsigned long) func; 280 lc->restart_data = (unsigned long) data; 281 lc->restart_source = -1UL; 282 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0); 283 } 284 285 /* 286 * Call function via PSW restart on pcpu and stop the current cpu. 287 */ 288 static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *), 289 void *data, unsigned long stack) 290 { 291 struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices]; 292 unsigned long source_cpu = stap(); 293 294 __load_psw_mask(PSW_KERNEL_BITS); 295 if (pcpu->address == source_cpu) 296 func(data); /* should not return */ 297 /* Stop target cpu (if func returns this stops the current cpu). */ 298 pcpu_sigp_retry(pcpu, SIGP_STOP, 0); 299 /* Restart func on the target cpu and stop the current cpu. */ 300 mem_assign_absolute(lc->restart_stack, stack); 301 mem_assign_absolute(lc->restart_fn, (unsigned long) func); 302 mem_assign_absolute(lc->restart_data, (unsigned long) data); 303 mem_assign_absolute(lc->restart_source, source_cpu); 304 asm volatile( 305 "0: sigp 0,%0,%2 # sigp restart to target cpu\n" 306 " brc 2,0b # busy, try again\n" 307 "1: sigp 0,%1,%3 # sigp stop to current cpu\n" 308 " brc 2,1b # busy, try again\n" 309 : : "d" (pcpu->address), "d" (source_cpu), 310 "K" (SIGP_RESTART), "K" (SIGP_STOP) 311 : "0", "1", "cc"); 312 for (;;) ; 313 } 314 315 /* 316 * Enable additional logical cpus for multi-threading. 317 */ 318 static int pcpu_set_smt(unsigned int mtid) 319 { 320 int cc; 321 322 if (smp_cpu_mtid == mtid) 323 return 0; 324 cc = __pcpu_sigp(0, SIGP_SET_MULTI_THREADING, mtid, NULL); 325 if (cc == 0) { 326 smp_cpu_mtid = mtid; 327 smp_cpu_mt_shift = 0; 328 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift)) 329 smp_cpu_mt_shift++; 330 pcpu_devices[0].address = stap(); 331 } 332 return cc; 333 } 334 335 /* 336 * Call function on an online CPU. 337 */ 338 void smp_call_online_cpu(void (*func)(void *), void *data) 339 { 340 struct pcpu *pcpu; 341 342 /* Use the current cpu if it is online. */ 343 pcpu = pcpu_find_address(cpu_online_mask, stap()); 344 if (!pcpu) 345 /* Use the first online cpu. */ 346 pcpu = pcpu_devices + cpumask_first(cpu_online_mask); 347 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack); 348 } 349 350 /* 351 * Call function on the ipl CPU. 352 */ 353 void smp_call_ipl_cpu(void (*func)(void *), void *data) 354 { 355 pcpu_delegate(&pcpu_devices[0], func, data, 356 pcpu_devices->lowcore->panic_stack - 357 PANIC_FRAME_OFFSET + PAGE_SIZE); 358 } 359 360 int smp_find_processor_id(u16 address) 361 { 362 int cpu; 363 364 for_each_present_cpu(cpu) 365 if (pcpu_devices[cpu].address == address) 366 return cpu; 367 return -1; 368 } 369 370 bool arch_vcpu_is_preempted(int cpu) 371 { 372 if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu)) 373 return false; 374 if (pcpu_running(pcpu_devices + cpu)) 375 return false; 376 return true; 377 } 378 EXPORT_SYMBOL(arch_vcpu_is_preempted); 379 380 void smp_yield_cpu(int cpu) 381 { 382 if (MACHINE_HAS_DIAG9C) { 383 diag_stat_inc_norecursion(DIAG_STAT_X09C); 384 asm volatile("diag %0,0,0x9c" 385 : : "d" (pcpu_devices[cpu].address)); 386 } else if (MACHINE_HAS_DIAG44) { 387 diag_stat_inc_norecursion(DIAG_STAT_X044); 388 asm volatile("diag 0,0,0x44"); 389 } 390 } 391 392 /* 393 * Send cpus emergency shutdown signal. This gives the cpus the 394 * opportunity to complete outstanding interrupts. 395 */ 396 static void smp_emergency_stop(cpumask_t *cpumask) 397 { 398 u64 end; 399 int cpu; 400 401 end = get_tod_clock() + (1000000UL << 12); 402 for_each_cpu(cpu, cpumask) { 403 struct pcpu *pcpu = pcpu_devices + cpu; 404 set_bit(ec_stop_cpu, &pcpu->ec_mask); 405 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL, 406 0, NULL) == SIGP_CC_BUSY && 407 get_tod_clock() < end) 408 cpu_relax(); 409 } 410 while (get_tod_clock() < end) { 411 for_each_cpu(cpu, cpumask) 412 if (pcpu_stopped(pcpu_devices + cpu)) 413 cpumask_clear_cpu(cpu, cpumask); 414 if (cpumask_empty(cpumask)) 415 break; 416 cpu_relax(); 417 } 418 } 419 420 /* 421 * Stop all cpus but the current one. 422 */ 423 void smp_send_stop(void) 424 { 425 cpumask_t cpumask; 426 int cpu; 427 428 /* Disable all interrupts/machine checks */ 429 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); 430 trace_hardirqs_off(); 431 432 debug_set_critical(); 433 cpumask_copy(&cpumask, cpu_online_mask); 434 cpumask_clear_cpu(smp_processor_id(), &cpumask); 435 436 if (oops_in_progress) 437 smp_emergency_stop(&cpumask); 438 439 /* stop all processors */ 440 for_each_cpu(cpu, &cpumask) { 441 struct pcpu *pcpu = pcpu_devices + cpu; 442 pcpu_sigp_retry(pcpu, SIGP_STOP, 0); 443 while (!pcpu_stopped(pcpu)) 444 cpu_relax(); 445 } 446 } 447 448 /* 449 * This is the main routine where commands issued by other 450 * cpus are handled. 451 */ 452 static void smp_handle_ext_call(void) 453 { 454 unsigned long bits; 455 456 /* handle bit signal external calls */ 457 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0); 458 if (test_bit(ec_stop_cpu, &bits)) 459 smp_stop_cpu(); 460 if (test_bit(ec_schedule, &bits)) 461 scheduler_ipi(); 462 if (test_bit(ec_call_function_single, &bits)) 463 generic_smp_call_function_single_interrupt(); 464 } 465 466 static void do_ext_call_interrupt(struct ext_code ext_code, 467 unsigned int param32, unsigned long param64) 468 { 469 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS); 470 smp_handle_ext_call(); 471 } 472 473 void arch_send_call_function_ipi_mask(const struct cpumask *mask) 474 { 475 int cpu; 476 477 for_each_cpu(cpu, mask) 478 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); 479 } 480 481 void arch_send_call_function_single_ipi(int cpu) 482 { 483 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); 484 } 485 486 /* 487 * this function sends a 'reschedule' IPI to another CPU. 488 * it goes straight through and wastes no time serializing 489 * anything. Worst case is that we lose a reschedule ... 490 */ 491 void smp_send_reschedule(int cpu) 492 { 493 pcpu_ec_call(pcpu_devices + cpu, ec_schedule); 494 } 495 496 /* 497 * parameter area for the set/clear control bit callbacks 498 */ 499 struct ec_creg_mask_parms { 500 unsigned long orval; 501 unsigned long andval; 502 int cr; 503 }; 504 505 /* 506 * callback for setting/clearing control bits 507 */ 508 static void smp_ctl_bit_callback(void *info) 509 { 510 struct ec_creg_mask_parms *pp = info; 511 unsigned long cregs[16]; 512 513 __ctl_store(cregs, 0, 15); 514 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval; 515 __ctl_load(cregs, 0, 15); 516 } 517 518 /* 519 * Set a bit in a control register of all cpus 520 */ 521 void smp_ctl_set_bit(int cr, int bit) 522 { 523 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr }; 524 525 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 526 } 527 EXPORT_SYMBOL(smp_ctl_set_bit); 528 529 /* 530 * Clear a bit in a control register of all cpus 531 */ 532 void smp_ctl_clear_bit(int cr, int bit) 533 { 534 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr }; 535 536 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 537 } 538 EXPORT_SYMBOL(smp_ctl_clear_bit); 539 540 #ifdef CONFIG_CRASH_DUMP 541 542 int smp_store_status(int cpu) 543 { 544 struct pcpu *pcpu = pcpu_devices + cpu; 545 unsigned long pa; 546 547 pa = __pa(&pcpu->lowcore->floating_pt_save_area); 548 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS, 549 pa) != SIGP_CC_ORDER_CODE_ACCEPTED) 550 return -EIO; 551 if (!MACHINE_HAS_VX) 552 return 0; 553 pa = __pa(pcpu->lowcore->vector_save_area_addr); 554 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS, 555 pa) != SIGP_CC_ORDER_CODE_ACCEPTED) 556 return -EIO; 557 return 0; 558 } 559 560 /* 561 * Collect CPU state of the previous, crashed system. 562 * There are four cases: 563 * 1) standard zfcp dump 564 * condition: OLDMEM_BASE == NULL && ipl_info.type == IPL_TYPE_FCP_DUMP 565 * The state for all CPUs except the boot CPU needs to be collected 566 * with sigp stop-and-store-status. The boot CPU state is located in 567 * the absolute lowcore of the memory stored in the HSA. The zcore code 568 * will copy the boot CPU state from the HSA. 569 * 2) stand-alone kdump for SCSI (zfcp dump with swapped memory) 570 * condition: OLDMEM_BASE != NULL && ipl_info.type == IPL_TYPE_FCP_DUMP 571 * The state for all CPUs except the boot CPU needs to be collected 572 * with sigp stop-and-store-status. The firmware or the boot-loader 573 * stored the registers of the boot CPU in the absolute lowcore in the 574 * memory of the old system. 575 * 3) kdump and the old kernel did not store the CPU state, 576 * or stand-alone kdump for DASD 577 * condition: OLDMEM_BASE != NULL && !is_kdump_kernel() 578 * The state for all CPUs except the boot CPU needs to be collected 579 * with sigp stop-and-store-status. The kexec code or the boot-loader 580 * stored the registers of the boot CPU in the memory of the old system. 581 * 4) kdump and the old kernel stored the CPU state 582 * condition: OLDMEM_BASE != NULL && is_kdump_kernel() 583 * This case does not exist for s390 anymore, setup_arch explicitly 584 * deactivates the elfcorehdr= kernel parameter 585 */ 586 static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr, 587 bool is_boot_cpu, unsigned long page) 588 { 589 __vector128 *vxrs = (__vector128 *) page; 590 591 if (is_boot_cpu) 592 vxrs = boot_cpu_vector_save_area; 593 else 594 __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page); 595 save_area_add_vxrs(sa, vxrs); 596 } 597 598 static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr, 599 bool is_boot_cpu, unsigned long page) 600 { 601 void *regs = (void *) page; 602 603 if (is_boot_cpu) 604 copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512); 605 else 606 __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page); 607 save_area_add_regs(sa, regs); 608 } 609 610 void __init smp_save_dump_cpus(void) 611 { 612 int addr, boot_cpu_addr, max_cpu_addr; 613 struct save_area *sa; 614 unsigned long page; 615 bool is_boot_cpu; 616 617 if (!(OLDMEM_BASE || ipl_info.type == IPL_TYPE_FCP_DUMP)) 618 /* No previous system present, normal boot. */ 619 return; 620 /* Allocate a page as dumping area for the store status sigps */ 621 page = memblock_alloc_base(PAGE_SIZE, PAGE_SIZE, 1UL << 31); 622 /* Set multi-threading state to the previous system. */ 623 pcpu_set_smt(sclp.mtid_prev); 624 boot_cpu_addr = stap(); 625 max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev; 626 for (addr = 0; addr <= max_cpu_addr; addr++) { 627 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) == 628 SIGP_CC_NOT_OPERATIONAL) 629 continue; 630 is_boot_cpu = (addr == boot_cpu_addr); 631 /* Allocate save area */ 632 sa = save_area_alloc(is_boot_cpu); 633 if (!sa) 634 panic("could not allocate memory for save area\n"); 635 if (MACHINE_HAS_VX) 636 /* Get the vector registers */ 637 smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page); 638 /* 639 * For a zfcp dump OLDMEM_BASE == NULL and the registers 640 * of the boot CPU are stored in the HSA. To retrieve 641 * these registers an SCLP request is required which is 642 * done by drivers/s390/char/zcore.c:init_cpu_info() 643 */ 644 if (!is_boot_cpu || OLDMEM_BASE) 645 /* Get the CPU registers */ 646 smp_save_cpu_regs(sa, addr, is_boot_cpu, page); 647 } 648 memblock_free(page, PAGE_SIZE); 649 diag308_reset(); 650 pcpu_set_smt(0); 651 } 652 #endif /* CONFIG_CRASH_DUMP */ 653 654 void smp_cpu_set_polarization(int cpu, int val) 655 { 656 pcpu_devices[cpu].polarization = val; 657 } 658 659 int smp_cpu_get_polarization(int cpu) 660 { 661 return pcpu_devices[cpu].polarization; 662 } 663 664 static void __ref smp_get_core_info(struct sclp_core_info *info, int early) 665 { 666 static int use_sigp_detection; 667 int address; 668 669 if (use_sigp_detection || sclp_get_core_info(info, early)) { 670 use_sigp_detection = 1; 671 for (address = 0; 672 address < (SCLP_MAX_CORES << smp_cpu_mt_shift); 673 address += (1U << smp_cpu_mt_shift)) { 674 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) == 675 SIGP_CC_NOT_OPERATIONAL) 676 continue; 677 info->core[info->configured].core_id = 678 address >> smp_cpu_mt_shift; 679 info->configured++; 680 } 681 info->combined = info->configured; 682 } 683 } 684 685 static int smp_add_present_cpu(int cpu); 686 687 static int __smp_rescan_cpus(struct sclp_core_info *info, int sysfs_add) 688 { 689 struct pcpu *pcpu; 690 cpumask_t avail; 691 int cpu, nr, i, j; 692 u16 address; 693 694 nr = 0; 695 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask); 696 cpu = cpumask_first(&avail); 697 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) { 698 if (sclp.has_core_type && info->core[i].type != boot_core_type) 699 continue; 700 address = info->core[i].core_id << smp_cpu_mt_shift; 701 for (j = 0; j <= smp_cpu_mtid; j++) { 702 if (pcpu_find_address(cpu_present_mask, address + j)) 703 continue; 704 pcpu = pcpu_devices + cpu; 705 pcpu->address = address + j; 706 pcpu->state = 707 (cpu >= info->configured*(smp_cpu_mtid + 1)) ? 708 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED; 709 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 710 set_cpu_present(cpu, true); 711 if (sysfs_add && smp_add_present_cpu(cpu) != 0) 712 set_cpu_present(cpu, false); 713 else 714 nr++; 715 cpu = cpumask_next(cpu, &avail); 716 if (cpu >= nr_cpu_ids) 717 break; 718 } 719 } 720 return nr; 721 } 722 723 void __init smp_detect_cpus(void) 724 { 725 unsigned int cpu, mtid, c_cpus, s_cpus; 726 struct sclp_core_info *info; 727 u16 address; 728 729 /* Get CPU information */ 730 info = memblock_virt_alloc(sizeof(*info), 8); 731 smp_get_core_info(info, 1); 732 /* Find boot CPU type */ 733 if (sclp.has_core_type) { 734 address = stap(); 735 for (cpu = 0; cpu < info->combined; cpu++) 736 if (info->core[cpu].core_id == address) { 737 /* The boot cpu dictates the cpu type. */ 738 boot_core_type = info->core[cpu].type; 739 break; 740 } 741 if (cpu >= info->combined) 742 panic("Could not find boot CPU type"); 743 } 744 745 /* Set multi-threading state for the current system */ 746 mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp; 747 mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1; 748 pcpu_set_smt(mtid); 749 750 /* Print number of CPUs */ 751 c_cpus = s_cpus = 0; 752 for (cpu = 0; cpu < info->combined; cpu++) { 753 if (sclp.has_core_type && 754 info->core[cpu].type != boot_core_type) 755 continue; 756 if (cpu < info->configured) 757 c_cpus += smp_cpu_mtid + 1; 758 else 759 s_cpus += smp_cpu_mtid + 1; 760 } 761 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus); 762 763 /* Add CPUs present at boot */ 764 get_online_cpus(); 765 __smp_rescan_cpus(info, 0); 766 put_online_cpus(); 767 memblock_free_early((unsigned long)info, sizeof(*info)); 768 } 769 770 /* 771 * Activate a secondary processor. 772 */ 773 static void smp_start_secondary(void *cpuvoid) 774 { 775 S390_lowcore.last_update_clock = get_tod_clock(); 776 S390_lowcore.restart_stack = (unsigned long) restart_stack; 777 S390_lowcore.restart_fn = (unsigned long) do_restart; 778 S390_lowcore.restart_data = 0; 779 S390_lowcore.restart_source = -1UL; 780 restore_access_regs(S390_lowcore.access_regs_save_area); 781 __ctl_load(S390_lowcore.cregs_save_area, 0, 15); 782 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); 783 cpu_init(); 784 preempt_disable(); 785 init_cpu_timer(); 786 vtime_init(); 787 pfault_init(); 788 notify_cpu_starting(smp_processor_id()); 789 set_cpu_online(smp_processor_id(), true); 790 inc_irq_stat(CPU_RST); 791 local_irq_enable(); 792 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); 793 } 794 795 /* Upping and downing of CPUs */ 796 int __cpu_up(unsigned int cpu, struct task_struct *tidle) 797 { 798 struct pcpu *pcpu; 799 int base, i, rc; 800 801 pcpu = pcpu_devices + cpu; 802 if (pcpu->state != CPU_STATE_CONFIGURED) 803 return -EIO; 804 base = smp_get_base_cpu(cpu); 805 for (i = 0; i <= smp_cpu_mtid; i++) { 806 if (base + i < nr_cpu_ids) 807 if (cpu_online(base + i)) 808 break; 809 } 810 /* 811 * If this is the first CPU of the core to get online 812 * do an initial CPU reset. 813 */ 814 if (i > smp_cpu_mtid && 815 pcpu_sigp_retry(pcpu_devices + base, SIGP_INITIAL_CPU_RESET, 0) != 816 SIGP_CC_ORDER_CODE_ACCEPTED) 817 return -EIO; 818 819 rc = pcpu_alloc_lowcore(pcpu, cpu); 820 if (rc) 821 return rc; 822 pcpu_prepare_secondary(pcpu, cpu); 823 pcpu_attach_task(pcpu, tidle); 824 pcpu_start_fn(pcpu, smp_start_secondary, NULL); 825 /* Wait until cpu puts itself in the online & active maps */ 826 while (!cpu_online(cpu)) 827 cpu_relax(); 828 return 0; 829 } 830 831 static unsigned int setup_possible_cpus __initdata; 832 833 static int __init _setup_possible_cpus(char *s) 834 { 835 get_option(&s, &setup_possible_cpus); 836 return 0; 837 } 838 early_param("possible_cpus", _setup_possible_cpus); 839 840 #ifdef CONFIG_HOTPLUG_CPU 841 842 int __cpu_disable(void) 843 { 844 unsigned long cregs[16]; 845 846 /* Handle possible pending IPIs */ 847 smp_handle_ext_call(); 848 set_cpu_online(smp_processor_id(), false); 849 /* Disable pseudo page faults on this cpu. */ 850 pfault_fini(); 851 /* Disable interrupt sources via control register. */ 852 __ctl_store(cregs, 0, 15); 853 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */ 854 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */ 855 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */ 856 __ctl_load(cregs, 0, 15); 857 clear_cpu_flag(CIF_NOHZ_DELAY); 858 return 0; 859 } 860 861 void __cpu_die(unsigned int cpu) 862 { 863 struct pcpu *pcpu; 864 865 /* Wait until target cpu is down */ 866 pcpu = pcpu_devices + cpu; 867 while (!pcpu_stopped(pcpu)) 868 cpu_relax(); 869 pcpu_free_lowcore(pcpu); 870 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm)); 871 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask); 872 } 873 874 void __noreturn cpu_die(void) 875 { 876 idle_task_exit(); 877 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0); 878 for (;;) ; 879 } 880 881 #endif /* CONFIG_HOTPLUG_CPU */ 882 883 void __init smp_fill_possible_mask(void) 884 { 885 unsigned int possible, sclp_max, cpu; 886 887 sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1; 888 sclp_max = min(smp_max_threads, sclp_max); 889 sclp_max = (sclp.max_cores * sclp_max) ?: nr_cpu_ids; 890 possible = setup_possible_cpus ?: nr_cpu_ids; 891 possible = min(possible, sclp_max); 892 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++) 893 set_cpu_possible(cpu, true); 894 } 895 896 void __init smp_prepare_cpus(unsigned int max_cpus) 897 { 898 /* request the 0x1201 emergency signal external interrupt */ 899 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt)) 900 panic("Couldn't request external interrupt 0x1201"); 901 /* request the 0x1202 external call external interrupt */ 902 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt)) 903 panic("Couldn't request external interrupt 0x1202"); 904 } 905 906 void __init smp_prepare_boot_cpu(void) 907 { 908 struct pcpu *pcpu = pcpu_devices; 909 910 pcpu->state = CPU_STATE_CONFIGURED; 911 pcpu->address = stap(); 912 pcpu->lowcore = (struct lowcore *)(unsigned long) store_prefix(); 913 S390_lowcore.percpu_offset = __per_cpu_offset[0]; 914 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN); 915 set_cpu_present(0, true); 916 set_cpu_online(0, true); 917 } 918 919 void __init smp_cpus_done(unsigned int max_cpus) 920 { 921 } 922 923 void __init smp_setup_processor_id(void) 924 { 925 S390_lowcore.cpu_nr = 0; 926 S390_lowcore.spinlock_lockval = arch_spin_lockval(0); 927 } 928 929 /* 930 * the frequency of the profiling timer can be changed 931 * by writing a multiplier value into /proc/profile. 932 * 933 * usually you want to run this on all CPUs ;) 934 */ 935 int setup_profiling_timer(unsigned int multiplier) 936 { 937 return 0; 938 } 939 940 #ifdef CONFIG_HOTPLUG_CPU 941 static ssize_t cpu_configure_show(struct device *dev, 942 struct device_attribute *attr, char *buf) 943 { 944 ssize_t count; 945 946 mutex_lock(&smp_cpu_state_mutex); 947 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state); 948 mutex_unlock(&smp_cpu_state_mutex); 949 return count; 950 } 951 952 static ssize_t cpu_configure_store(struct device *dev, 953 struct device_attribute *attr, 954 const char *buf, size_t count) 955 { 956 struct pcpu *pcpu; 957 int cpu, val, rc, i; 958 char delim; 959 960 if (sscanf(buf, "%d %c", &val, &delim) != 1) 961 return -EINVAL; 962 if (val != 0 && val != 1) 963 return -EINVAL; 964 get_online_cpus(); 965 mutex_lock(&smp_cpu_state_mutex); 966 rc = -EBUSY; 967 /* disallow configuration changes of online cpus and cpu 0 */ 968 cpu = dev->id; 969 cpu = smp_get_base_cpu(cpu); 970 if (cpu == 0) 971 goto out; 972 for (i = 0; i <= smp_cpu_mtid; i++) 973 if (cpu_online(cpu + i)) 974 goto out; 975 pcpu = pcpu_devices + cpu; 976 rc = 0; 977 switch (val) { 978 case 0: 979 if (pcpu->state != CPU_STATE_CONFIGURED) 980 break; 981 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift); 982 if (rc) 983 break; 984 for (i = 0; i <= smp_cpu_mtid; i++) { 985 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i)) 986 continue; 987 pcpu[i].state = CPU_STATE_STANDBY; 988 smp_cpu_set_polarization(cpu + i, 989 POLARIZATION_UNKNOWN); 990 } 991 topology_expect_change(); 992 break; 993 case 1: 994 if (pcpu->state != CPU_STATE_STANDBY) 995 break; 996 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift); 997 if (rc) 998 break; 999 for (i = 0; i <= smp_cpu_mtid; i++) { 1000 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i)) 1001 continue; 1002 pcpu[i].state = CPU_STATE_CONFIGURED; 1003 smp_cpu_set_polarization(cpu + i, 1004 POLARIZATION_UNKNOWN); 1005 } 1006 topology_expect_change(); 1007 break; 1008 default: 1009 break; 1010 } 1011 out: 1012 mutex_unlock(&smp_cpu_state_mutex); 1013 put_online_cpus(); 1014 return rc ? rc : count; 1015 } 1016 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store); 1017 #endif /* CONFIG_HOTPLUG_CPU */ 1018 1019 static ssize_t show_cpu_address(struct device *dev, 1020 struct device_attribute *attr, char *buf) 1021 { 1022 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address); 1023 } 1024 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL); 1025 1026 static struct attribute *cpu_common_attrs[] = { 1027 #ifdef CONFIG_HOTPLUG_CPU 1028 &dev_attr_configure.attr, 1029 #endif 1030 &dev_attr_address.attr, 1031 NULL, 1032 }; 1033 1034 static struct attribute_group cpu_common_attr_group = { 1035 .attrs = cpu_common_attrs, 1036 }; 1037 1038 static struct attribute *cpu_online_attrs[] = { 1039 &dev_attr_idle_count.attr, 1040 &dev_attr_idle_time_us.attr, 1041 NULL, 1042 }; 1043 1044 static struct attribute_group cpu_online_attr_group = { 1045 .attrs = cpu_online_attrs, 1046 }; 1047 1048 static int smp_cpu_online(unsigned int cpu) 1049 { 1050 struct device *s = &per_cpu(cpu_device, cpu)->dev; 1051 1052 return sysfs_create_group(&s->kobj, &cpu_online_attr_group); 1053 } 1054 static int smp_cpu_pre_down(unsigned int cpu) 1055 { 1056 struct device *s = &per_cpu(cpu_device, cpu)->dev; 1057 1058 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 1059 return 0; 1060 } 1061 1062 static int smp_add_present_cpu(int cpu) 1063 { 1064 struct device *s; 1065 struct cpu *c; 1066 int rc; 1067 1068 c = kzalloc(sizeof(*c), GFP_KERNEL); 1069 if (!c) 1070 return -ENOMEM; 1071 per_cpu(cpu_device, cpu) = c; 1072 s = &c->dev; 1073 c->hotpluggable = 1; 1074 rc = register_cpu(c, cpu); 1075 if (rc) 1076 goto out; 1077 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group); 1078 if (rc) 1079 goto out_cpu; 1080 rc = topology_cpu_init(c); 1081 if (rc) 1082 goto out_topology; 1083 return 0; 1084 1085 out_topology: 1086 sysfs_remove_group(&s->kobj, &cpu_common_attr_group); 1087 out_cpu: 1088 #ifdef CONFIG_HOTPLUG_CPU 1089 unregister_cpu(c); 1090 #endif 1091 out: 1092 return rc; 1093 } 1094 1095 #ifdef CONFIG_HOTPLUG_CPU 1096 1097 int __ref smp_rescan_cpus(void) 1098 { 1099 struct sclp_core_info *info; 1100 int nr; 1101 1102 info = kzalloc(sizeof(*info), GFP_KERNEL); 1103 if (!info) 1104 return -ENOMEM; 1105 smp_get_core_info(info, 0); 1106 get_online_cpus(); 1107 mutex_lock(&smp_cpu_state_mutex); 1108 nr = __smp_rescan_cpus(info, 1); 1109 mutex_unlock(&smp_cpu_state_mutex); 1110 put_online_cpus(); 1111 kfree(info); 1112 if (nr) 1113 topology_schedule_update(); 1114 return 0; 1115 } 1116 1117 static ssize_t __ref rescan_store(struct device *dev, 1118 struct device_attribute *attr, 1119 const char *buf, 1120 size_t count) 1121 { 1122 int rc; 1123 1124 rc = smp_rescan_cpus(); 1125 return rc ? rc : count; 1126 } 1127 static DEVICE_ATTR(rescan, 0200, NULL, rescan_store); 1128 #endif /* CONFIG_HOTPLUG_CPU */ 1129 1130 static int __init s390_smp_init(void) 1131 { 1132 int cpu, rc = 0; 1133 1134 #ifdef CONFIG_HOTPLUG_CPU 1135 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan); 1136 if (rc) 1137 return rc; 1138 #endif 1139 for_each_present_cpu(cpu) { 1140 rc = smp_add_present_cpu(cpu); 1141 if (rc) 1142 goto out; 1143 } 1144 1145 rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "s390/smp:online", 1146 smp_cpu_online, smp_cpu_pre_down); 1147 out: 1148 return rc; 1149 } 1150 subsys_initcall(s390_smp_init); 1151