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/module.h> 23 #include <linux/init.h> 24 #include <linux/mm.h> 25 #include <linux/err.h> 26 #include <linux/spinlock.h> 27 #include <linux/kernel_stat.h> 28 #include <linux/delay.h> 29 #include <linux/interrupt.h> 30 #include <linux/irqflags.h> 31 #include <linux/cpu.h> 32 #include <linux/slab.h> 33 #include <linux/crash_dump.h> 34 #include <linux/memblock.h> 35 #include <asm/asm-offsets.h> 36 #include <asm/switch_to.h> 37 #include <asm/facility.h> 38 #include <asm/ipl.h> 39 #include <asm/setup.h> 40 #include <asm/irq.h> 41 #include <asm/tlbflush.h> 42 #include <asm/vtimer.h> 43 #include <asm/lowcore.h> 44 #include <asm/sclp.h> 45 #include <asm/vdso.h> 46 #include <asm/debug.h> 47 #include <asm/os_info.h> 48 #include <asm/sigp.h> 49 #include <asm/idle.h> 50 #include "entry.h" 51 52 enum { 53 ec_schedule = 0, 54 ec_call_function_single, 55 ec_stop_cpu, 56 }; 57 58 enum { 59 CPU_STATE_STANDBY, 60 CPU_STATE_CONFIGURED, 61 }; 62 63 static DEFINE_PER_CPU(struct cpu *, cpu_device); 64 65 struct pcpu { 66 struct _lowcore *lowcore; /* lowcore page(s) for the cpu */ 67 unsigned long ec_mask; /* bit mask for ec_xxx functions */ 68 signed char state; /* physical cpu state */ 69 signed char polarization; /* physical polarization */ 70 u16 address; /* physical cpu address */ 71 }; 72 73 static u8 boot_core_type; 74 static struct pcpu pcpu_devices[NR_CPUS]; 75 76 unsigned int smp_cpu_mt_shift; 77 EXPORT_SYMBOL(smp_cpu_mt_shift); 78 79 unsigned int smp_cpu_mtid; 80 EXPORT_SYMBOL(smp_cpu_mtid); 81 82 static unsigned int smp_max_threads __initdata = -1U; 83 84 static int __init early_nosmt(char *s) 85 { 86 smp_max_threads = 1; 87 return 0; 88 } 89 early_param("nosmt", early_nosmt); 90 91 static int __init early_smt(char *s) 92 { 93 get_option(&s, &smp_max_threads); 94 return 0; 95 } 96 early_param("smt", early_smt); 97 98 /* 99 * The smp_cpu_state_mutex must be held when changing the state or polarization 100 * member of a pcpu data structure within the pcpu_devices arreay. 101 */ 102 DEFINE_MUTEX(smp_cpu_state_mutex); 103 104 /* 105 * Signal processor helper functions. 106 */ 107 static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm, 108 u32 *status) 109 { 110 int cc; 111 112 while (1) { 113 cc = __pcpu_sigp(addr, order, parm, NULL); 114 if (cc != SIGP_CC_BUSY) 115 return cc; 116 cpu_relax(); 117 } 118 } 119 120 static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm) 121 { 122 int cc, retry; 123 124 for (retry = 0; ; retry++) { 125 cc = __pcpu_sigp(pcpu->address, order, parm, NULL); 126 if (cc != SIGP_CC_BUSY) 127 break; 128 if (retry >= 3) 129 udelay(10); 130 } 131 return cc; 132 } 133 134 static inline int pcpu_stopped(struct pcpu *pcpu) 135 { 136 u32 uninitialized_var(status); 137 138 if (__pcpu_sigp(pcpu->address, SIGP_SENSE, 139 0, &status) != SIGP_CC_STATUS_STORED) 140 return 0; 141 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED)); 142 } 143 144 static inline int pcpu_running(struct pcpu *pcpu) 145 { 146 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING, 147 0, NULL) != SIGP_CC_STATUS_STORED) 148 return 1; 149 /* Status stored condition code is equivalent to cpu not running. */ 150 return 0; 151 } 152 153 /* 154 * Find struct pcpu by cpu address. 155 */ 156 static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address) 157 { 158 int cpu; 159 160 for_each_cpu(cpu, mask) 161 if (pcpu_devices[cpu].address == address) 162 return pcpu_devices + cpu; 163 return NULL; 164 } 165 166 static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit) 167 { 168 int order; 169 170 if (test_and_set_bit(ec_bit, &pcpu->ec_mask)) 171 return; 172 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL; 173 pcpu_sigp_retry(pcpu, order, 0); 174 } 175 176 #define ASYNC_FRAME_OFFSET (ASYNC_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE) 177 #define PANIC_FRAME_OFFSET (PAGE_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE) 178 179 static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu) 180 { 181 unsigned long async_stack, panic_stack; 182 struct _lowcore *lc; 183 184 if (pcpu != &pcpu_devices[0]) { 185 pcpu->lowcore = (struct _lowcore *) 186 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); 187 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER); 188 panic_stack = __get_free_page(GFP_KERNEL); 189 if (!pcpu->lowcore || !panic_stack || !async_stack) 190 goto out; 191 } else { 192 async_stack = pcpu->lowcore->async_stack - ASYNC_FRAME_OFFSET; 193 panic_stack = pcpu->lowcore->panic_stack - PANIC_FRAME_OFFSET; 194 } 195 lc = pcpu->lowcore; 196 memcpy(lc, &S390_lowcore, 512); 197 memset((char *) lc + 512, 0, sizeof(*lc) - 512); 198 lc->async_stack = async_stack + ASYNC_FRAME_OFFSET; 199 lc->panic_stack = panic_stack + PANIC_FRAME_OFFSET; 200 lc->cpu_nr = cpu; 201 lc->spinlock_lockval = arch_spin_lockval(cpu); 202 if (MACHINE_HAS_VX) 203 lc->vector_save_area_addr = 204 (unsigned long) &lc->vector_save_area; 205 if (vdso_alloc_per_cpu(lc)) 206 goto out; 207 lowcore_ptr[cpu] = lc; 208 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc); 209 return 0; 210 out: 211 if (pcpu != &pcpu_devices[0]) { 212 free_page(panic_stack); 213 free_pages(async_stack, ASYNC_ORDER); 214 free_pages((unsigned long) pcpu->lowcore, LC_ORDER); 215 } 216 return -ENOMEM; 217 } 218 219 #ifdef CONFIG_HOTPLUG_CPU 220 221 static void pcpu_free_lowcore(struct pcpu *pcpu) 222 { 223 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0); 224 lowcore_ptr[pcpu - pcpu_devices] = NULL; 225 vdso_free_per_cpu(pcpu->lowcore); 226 if (pcpu == &pcpu_devices[0]) 227 return; 228 free_page(pcpu->lowcore->panic_stack-PANIC_FRAME_OFFSET); 229 free_pages(pcpu->lowcore->async_stack-ASYNC_FRAME_OFFSET, ASYNC_ORDER); 230 free_pages((unsigned long) pcpu->lowcore, LC_ORDER); 231 } 232 233 #endif /* CONFIG_HOTPLUG_CPU */ 234 235 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu) 236 { 237 struct _lowcore *lc = pcpu->lowcore; 238 239 if (MACHINE_HAS_TLB_LC) 240 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask); 241 cpumask_set_cpu(cpu, mm_cpumask(&init_mm)); 242 atomic_inc(&init_mm.context.attach_count); 243 lc->cpu_nr = cpu; 244 lc->spinlock_lockval = arch_spin_lockval(cpu); 245 lc->percpu_offset = __per_cpu_offset[cpu]; 246 lc->kernel_asce = S390_lowcore.kernel_asce; 247 lc->machine_flags = S390_lowcore.machine_flags; 248 lc->user_timer = lc->system_timer = lc->steal_timer = 0; 249 __ctl_store(lc->cregs_save_area, 0, 15); 250 save_access_regs((unsigned int *) lc->access_regs_save_area); 251 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list, 252 MAX_FACILITY_BIT/8); 253 } 254 255 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk) 256 { 257 struct _lowcore *lc = pcpu->lowcore; 258 struct thread_info *ti = task_thread_info(tsk); 259 260 lc->kernel_stack = (unsigned long) task_stack_page(tsk) 261 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); 262 lc->thread_info = (unsigned long) task_thread_info(tsk); 263 lc->current_task = (unsigned long) tsk; 264 lc->user_timer = ti->user_timer; 265 lc->system_timer = ti->system_timer; 266 lc->steal_timer = 0; 267 } 268 269 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data) 270 { 271 struct _lowcore *lc = pcpu->lowcore; 272 273 lc->restart_stack = lc->kernel_stack; 274 lc->restart_fn = (unsigned long) func; 275 lc->restart_data = (unsigned long) data; 276 lc->restart_source = -1UL; 277 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0); 278 } 279 280 /* 281 * Call function via PSW restart on pcpu and stop the current cpu. 282 */ 283 static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *), 284 void *data, unsigned long stack) 285 { 286 struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices]; 287 unsigned long source_cpu = stap(); 288 289 __load_psw_mask(PSW_KERNEL_BITS); 290 if (pcpu->address == source_cpu) 291 func(data); /* should not return */ 292 /* Stop target cpu (if func returns this stops the current cpu). */ 293 pcpu_sigp_retry(pcpu, SIGP_STOP, 0); 294 /* Restart func on the target cpu and stop the current cpu. */ 295 mem_assign_absolute(lc->restart_stack, stack); 296 mem_assign_absolute(lc->restart_fn, (unsigned long) func); 297 mem_assign_absolute(lc->restart_data, (unsigned long) data); 298 mem_assign_absolute(lc->restart_source, source_cpu); 299 asm volatile( 300 "0: sigp 0,%0,%2 # sigp restart to target cpu\n" 301 " brc 2,0b # busy, try again\n" 302 "1: sigp 0,%1,%3 # sigp stop to current cpu\n" 303 " brc 2,1b # busy, try again\n" 304 : : "d" (pcpu->address), "d" (source_cpu), 305 "K" (SIGP_RESTART), "K" (SIGP_STOP) 306 : "0", "1", "cc"); 307 for (;;) ; 308 } 309 310 /* 311 * Enable additional logical cpus for multi-threading. 312 */ 313 static int pcpu_set_smt(unsigned int mtid) 314 { 315 register unsigned long reg1 asm ("1") = (unsigned long) mtid; 316 int cc; 317 318 if (smp_cpu_mtid == mtid) 319 return 0; 320 asm volatile( 321 " sigp %1,0,%2 # sigp set multi-threading\n" 322 " ipm %0\n" 323 " srl %0,28\n" 324 : "=d" (cc) : "d" (reg1), "K" (SIGP_SET_MULTI_THREADING) 325 : "cc"); 326 if (cc == 0) { 327 smp_cpu_mtid = mtid; 328 smp_cpu_mt_shift = 0; 329 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift)) 330 smp_cpu_mt_shift++; 331 pcpu_devices[0].address = stap(); 332 } 333 return cc; 334 } 335 336 /* 337 * Call function on an online CPU. 338 */ 339 void smp_call_online_cpu(void (*func)(void *), void *data) 340 { 341 struct pcpu *pcpu; 342 343 /* Use the current cpu if it is online. */ 344 pcpu = pcpu_find_address(cpu_online_mask, stap()); 345 if (!pcpu) 346 /* Use the first online cpu. */ 347 pcpu = pcpu_devices + cpumask_first(cpu_online_mask); 348 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack); 349 } 350 351 /* 352 * Call function on the ipl CPU. 353 */ 354 void smp_call_ipl_cpu(void (*func)(void *), void *data) 355 { 356 pcpu_delegate(&pcpu_devices[0], func, data, 357 pcpu_devices->lowcore->panic_stack - 358 PANIC_FRAME_OFFSET + PAGE_SIZE); 359 } 360 361 int smp_find_processor_id(u16 address) 362 { 363 int cpu; 364 365 for_each_present_cpu(cpu) 366 if (pcpu_devices[cpu].address == address) 367 return cpu; 368 return -1; 369 } 370 371 int smp_vcpu_scheduled(int cpu) 372 { 373 return pcpu_running(pcpu_devices + cpu); 374 } 375 376 void smp_yield_cpu(int cpu) 377 { 378 if (MACHINE_HAS_DIAG9C) 379 asm volatile("diag %0,0,0x9c" 380 : : "d" (pcpu_devices[cpu].address)); 381 else if (MACHINE_HAS_DIAG44) 382 asm volatile("diag 0,0,0x44"); 383 } 384 385 /* 386 * Send cpus emergency shutdown signal. This gives the cpus the 387 * opportunity to complete outstanding interrupts. 388 */ 389 static void smp_emergency_stop(cpumask_t *cpumask) 390 { 391 u64 end; 392 int cpu; 393 394 end = get_tod_clock() + (1000000UL << 12); 395 for_each_cpu(cpu, cpumask) { 396 struct pcpu *pcpu = pcpu_devices + cpu; 397 set_bit(ec_stop_cpu, &pcpu->ec_mask); 398 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL, 399 0, NULL) == SIGP_CC_BUSY && 400 get_tod_clock() < end) 401 cpu_relax(); 402 } 403 while (get_tod_clock() < end) { 404 for_each_cpu(cpu, cpumask) 405 if (pcpu_stopped(pcpu_devices + cpu)) 406 cpumask_clear_cpu(cpu, cpumask); 407 if (cpumask_empty(cpumask)) 408 break; 409 cpu_relax(); 410 } 411 } 412 413 /* 414 * Stop all cpus but the current one. 415 */ 416 void smp_send_stop(void) 417 { 418 cpumask_t cpumask; 419 int cpu; 420 421 /* Disable all interrupts/machine checks */ 422 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); 423 trace_hardirqs_off(); 424 425 debug_set_critical(); 426 cpumask_copy(&cpumask, cpu_online_mask); 427 cpumask_clear_cpu(smp_processor_id(), &cpumask); 428 429 if (oops_in_progress) 430 smp_emergency_stop(&cpumask); 431 432 /* stop all processors */ 433 for_each_cpu(cpu, &cpumask) { 434 struct pcpu *pcpu = pcpu_devices + cpu; 435 pcpu_sigp_retry(pcpu, SIGP_STOP, 0); 436 while (!pcpu_stopped(pcpu)) 437 cpu_relax(); 438 } 439 } 440 441 /* 442 * This is the main routine where commands issued by other 443 * cpus are handled. 444 */ 445 static void smp_handle_ext_call(void) 446 { 447 unsigned long bits; 448 449 /* handle bit signal external calls */ 450 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0); 451 if (test_bit(ec_stop_cpu, &bits)) 452 smp_stop_cpu(); 453 if (test_bit(ec_schedule, &bits)) 454 scheduler_ipi(); 455 if (test_bit(ec_call_function_single, &bits)) 456 generic_smp_call_function_single_interrupt(); 457 } 458 459 static void do_ext_call_interrupt(struct ext_code ext_code, 460 unsigned int param32, unsigned long param64) 461 { 462 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS); 463 smp_handle_ext_call(); 464 } 465 466 void arch_send_call_function_ipi_mask(const struct cpumask *mask) 467 { 468 int cpu; 469 470 for_each_cpu(cpu, mask) 471 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); 472 } 473 474 void arch_send_call_function_single_ipi(int cpu) 475 { 476 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); 477 } 478 479 /* 480 * this function sends a 'reschedule' IPI to another CPU. 481 * it goes straight through and wastes no time serializing 482 * anything. Worst case is that we lose a reschedule ... 483 */ 484 void smp_send_reschedule(int cpu) 485 { 486 pcpu_ec_call(pcpu_devices + cpu, ec_schedule); 487 } 488 489 /* 490 * parameter area for the set/clear control bit callbacks 491 */ 492 struct ec_creg_mask_parms { 493 unsigned long orval; 494 unsigned long andval; 495 int cr; 496 }; 497 498 /* 499 * callback for setting/clearing control bits 500 */ 501 static void smp_ctl_bit_callback(void *info) 502 { 503 struct ec_creg_mask_parms *pp = info; 504 unsigned long cregs[16]; 505 506 __ctl_store(cregs, 0, 15); 507 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval; 508 __ctl_load(cregs, 0, 15); 509 } 510 511 /* 512 * Set a bit in a control register of all cpus 513 */ 514 void smp_ctl_set_bit(int cr, int bit) 515 { 516 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr }; 517 518 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 519 } 520 EXPORT_SYMBOL(smp_ctl_set_bit); 521 522 /* 523 * Clear a bit in a control register of all cpus 524 */ 525 void smp_ctl_clear_bit(int cr, int bit) 526 { 527 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr }; 528 529 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 530 } 531 EXPORT_SYMBOL(smp_ctl_clear_bit); 532 533 #ifdef CONFIG_CRASH_DUMP 534 535 static void __init __smp_store_cpu_state(struct save_area_ext *sa_ext, 536 u16 address, int is_boot_cpu) 537 { 538 void *lc = (void *)(unsigned long) store_prefix(); 539 unsigned long vx_sa; 540 541 if (is_boot_cpu) { 542 /* Copy the registers of the boot CPU. */ 543 copy_oldmem_page(1, (void *) &sa_ext->sa, sizeof(sa_ext->sa), 544 SAVE_AREA_BASE - PAGE_SIZE, 0); 545 if (MACHINE_HAS_VX) 546 save_vx_regs_safe(sa_ext->vx_regs); 547 return; 548 } 549 /* Get the registers of a non-boot cpu. */ 550 __pcpu_sigp_relax(address, SIGP_STOP_AND_STORE_STATUS, 0, NULL); 551 memcpy_real(&sa_ext->sa, lc + SAVE_AREA_BASE, sizeof(sa_ext->sa)); 552 if (!MACHINE_HAS_VX) 553 return; 554 /* Get the VX registers */ 555 vx_sa = memblock_alloc(PAGE_SIZE, PAGE_SIZE); 556 if (!vx_sa) 557 panic("could not allocate memory for VX save area\n"); 558 __pcpu_sigp_relax(address, SIGP_STORE_ADDITIONAL_STATUS, vx_sa, NULL); 559 memcpy(sa_ext->vx_regs, (void *) vx_sa, sizeof(sa_ext->vx_regs)); 560 memblock_free(vx_sa, PAGE_SIZE); 561 } 562 563 int smp_store_status(int cpu) 564 { 565 unsigned long vx_sa; 566 struct pcpu *pcpu; 567 568 pcpu = pcpu_devices + cpu; 569 if (__pcpu_sigp_relax(pcpu->address, SIGP_STOP_AND_STORE_STATUS, 570 0, NULL) != SIGP_CC_ORDER_CODE_ACCEPTED) 571 return -EIO; 572 if (!MACHINE_HAS_VX) 573 return 0; 574 vx_sa = __pa(pcpu->lowcore->vector_save_area_addr); 575 __pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS, 576 vx_sa, NULL); 577 return 0; 578 } 579 580 #endif /* CONFIG_CRASH_DUMP */ 581 582 /* 583 * Collect CPU state of the previous, crashed system. 584 * There are four cases: 585 * 1) standard zfcp dump 586 * condition: OLDMEM_BASE == NULL && ipl_info.type == IPL_TYPE_FCP_DUMP 587 * The state for all CPUs except the boot CPU needs to be collected 588 * with sigp stop-and-store-status. The boot CPU state is located in 589 * the absolute lowcore of the memory stored in the HSA. The zcore code 590 * will allocate the save area and copy the boot CPU state from the HSA. 591 * 2) stand-alone kdump for SCSI (zfcp dump with swapped memory) 592 * condition: OLDMEM_BASE != NULL && ipl_info.type == IPL_TYPE_FCP_DUMP 593 * The state for all CPUs except the boot CPU needs to be collected 594 * with sigp stop-and-store-status. The firmware or the boot-loader 595 * stored the registers of the boot CPU in the absolute lowcore in the 596 * memory of the old system. 597 * 3) kdump and the old kernel did not store the CPU state, 598 * or stand-alone kdump for DASD 599 * condition: OLDMEM_BASE != NULL && !is_kdump_kernel() 600 * The state for all CPUs except the boot CPU needs to be collected 601 * with sigp stop-and-store-status. The kexec code or the boot-loader 602 * stored the registers of the boot CPU in the memory of the old system. 603 * 4) kdump and the old kernel stored the CPU state 604 * condition: OLDMEM_BASE != NULL && is_kdump_kernel() 605 * The state of all CPUs is stored in ELF sections in the memory of the 606 * old system. The ELF sections are picked up by the crash_dump code 607 * via elfcorehdr_addr. 608 */ 609 void __init smp_save_dump_cpus(void) 610 { 611 #ifdef CONFIG_CRASH_DUMP 612 int addr, cpu, boot_cpu_addr, max_cpu_addr; 613 struct save_area_ext *sa_ext; 614 bool is_boot_cpu; 615 616 if (is_kdump_kernel()) 617 /* Previous system stored the CPU states. Nothing to do. */ 618 return; 619 if (!(OLDMEM_BASE || ipl_info.type == IPL_TYPE_FCP_DUMP)) 620 /* No previous system present, normal boot. */ 621 return; 622 /* Set multi-threading state to the previous system. */ 623 pcpu_set_smt(sclp.mtid_prev); 624 max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev; 625 for (cpu = 0, addr = 0; addr <= max_cpu_addr; addr++) { 626 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0, NULL) == 627 SIGP_CC_NOT_OPERATIONAL) 628 continue; 629 cpu += 1; 630 } 631 dump_save_areas.areas = (void *)memblock_alloc(sizeof(void *) * cpu, 8); 632 dump_save_areas.count = cpu; 633 boot_cpu_addr = stap(); 634 for (cpu = 0, addr = 0; addr <= max_cpu_addr; addr++) { 635 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0, NULL) == 636 SIGP_CC_NOT_OPERATIONAL) 637 continue; 638 sa_ext = (void *) memblock_alloc(sizeof(*sa_ext), 8); 639 dump_save_areas.areas[cpu] = sa_ext; 640 if (!sa_ext) 641 panic("could not allocate memory for save area\n"); 642 is_boot_cpu = (addr == boot_cpu_addr); 643 cpu += 1; 644 if (is_boot_cpu && !OLDMEM_BASE) 645 /* Skip boot CPU for standard zfcp dump. */ 646 continue; 647 /* Get state for this CPU. */ 648 __smp_store_cpu_state(sa_ext, addr, is_boot_cpu); 649 } 650 diag308_reset(); 651 pcpu_set_smt(0); 652 #endif /* CONFIG_CRASH_DUMP */ 653 } 654 655 void smp_cpu_set_polarization(int cpu, int val) 656 { 657 pcpu_devices[cpu].polarization = val; 658 } 659 660 int smp_cpu_get_polarization(int cpu) 661 { 662 return pcpu_devices[cpu].polarization; 663 } 664 665 static struct sclp_core_info *smp_get_core_info(void) 666 { 667 static int use_sigp_detection; 668 struct sclp_core_info *info; 669 int address; 670 671 info = kzalloc(sizeof(*info), GFP_KERNEL); 672 if (info && (use_sigp_detection || sclp_get_core_info(info))) { 673 use_sigp_detection = 1; 674 for (address = 0; 675 address < (SCLP_MAX_CORES << smp_cpu_mt_shift); 676 address += (1U << smp_cpu_mt_shift)) { 677 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0, NULL) == 678 SIGP_CC_NOT_OPERATIONAL) 679 continue; 680 info->core[info->configured].core_id = 681 address >> smp_cpu_mt_shift; 682 info->configured++; 683 } 684 info->combined = info->configured; 685 } 686 return info; 687 } 688 689 static int smp_add_present_cpu(int cpu); 690 691 static int __smp_rescan_cpus(struct sclp_core_info *info, int sysfs_add) 692 { 693 struct pcpu *pcpu; 694 cpumask_t avail; 695 int cpu, nr, i, j; 696 u16 address; 697 698 nr = 0; 699 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask); 700 cpu = cpumask_first(&avail); 701 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) { 702 if (sclp.has_core_type && info->core[i].type != boot_core_type) 703 continue; 704 address = info->core[i].core_id << smp_cpu_mt_shift; 705 for (j = 0; j <= smp_cpu_mtid; j++) { 706 if (pcpu_find_address(cpu_present_mask, address + j)) 707 continue; 708 pcpu = pcpu_devices + cpu; 709 pcpu->address = address + j; 710 pcpu->state = 711 (cpu >= info->configured*(smp_cpu_mtid + 1)) ? 712 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED; 713 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 714 set_cpu_present(cpu, true); 715 if (sysfs_add && smp_add_present_cpu(cpu) != 0) 716 set_cpu_present(cpu, false); 717 else 718 nr++; 719 cpu = cpumask_next(cpu, &avail); 720 if (cpu >= nr_cpu_ids) 721 break; 722 } 723 } 724 return nr; 725 } 726 727 static void __init smp_detect_cpus(void) 728 { 729 unsigned int cpu, mtid, c_cpus, s_cpus; 730 struct sclp_core_info *info; 731 u16 address; 732 733 /* Get CPU information */ 734 info = smp_get_core_info(); 735 if (!info) 736 panic("smp_detect_cpus failed to allocate memory\n"); 737 738 /* Find boot CPU type */ 739 if (sclp.has_core_type) { 740 address = stap(); 741 for (cpu = 0; cpu < info->combined; cpu++) 742 if (info->core[cpu].core_id == address) { 743 /* The boot cpu dictates the cpu type. */ 744 boot_core_type = info->core[cpu].type; 745 break; 746 } 747 if (cpu >= info->combined) 748 panic("Could not find boot CPU type"); 749 } 750 751 /* Set multi-threading state for the current system */ 752 mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp; 753 mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1; 754 pcpu_set_smt(mtid); 755 756 /* Print number of CPUs */ 757 c_cpus = s_cpus = 0; 758 for (cpu = 0; cpu < info->combined; cpu++) { 759 if (sclp.has_core_type && 760 info->core[cpu].type != boot_core_type) 761 continue; 762 if (cpu < info->configured) 763 c_cpus += smp_cpu_mtid + 1; 764 else 765 s_cpus += smp_cpu_mtid + 1; 766 } 767 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus); 768 769 /* Add CPUs present at boot */ 770 get_online_cpus(); 771 __smp_rescan_cpus(info, 0); 772 put_online_cpus(); 773 kfree(info); 774 } 775 776 /* 777 * Activate a secondary processor. 778 */ 779 static void smp_start_secondary(void *cpuvoid) 780 { 781 S390_lowcore.last_update_clock = get_tod_clock(); 782 S390_lowcore.restart_stack = (unsigned long) restart_stack; 783 S390_lowcore.restart_fn = (unsigned long) do_restart; 784 S390_lowcore.restart_data = 0; 785 S390_lowcore.restart_source = -1UL; 786 restore_access_regs(S390_lowcore.access_regs_save_area); 787 __ctl_load(S390_lowcore.cregs_save_area, 0, 15); 788 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); 789 cpu_init(); 790 preempt_disable(); 791 init_cpu_timer(); 792 vtime_init(); 793 pfault_init(); 794 notify_cpu_starting(smp_processor_id()); 795 set_cpu_online(smp_processor_id(), true); 796 inc_irq_stat(CPU_RST); 797 local_irq_enable(); 798 cpu_startup_entry(CPUHP_ONLINE); 799 } 800 801 /* Upping and downing of CPUs */ 802 int __cpu_up(unsigned int cpu, struct task_struct *tidle) 803 { 804 struct pcpu *pcpu; 805 int base, i, rc; 806 807 pcpu = pcpu_devices + cpu; 808 if (pcpu->state != CPU_STATE_CONFIGURED) 809 return -EIO; 810 base = cpu - (cpu % (smp_cpu_mtid + 1)); 811 for (i = 0; i <= smp_cpu_mtid; i++) { 812 if (base + i < nr_cpu_ids) 813 if (cpu_online(base + i)) 814 break; 815 } 816 /* 817 * If this is the first CPU of the core to get online 818 * do an initial CPU reset. 819 */ 820 if (i > smp_cpu_mtid && 821 pcpu_sigp_retry(pcpu_devices + base, SIGP_INITIAL_CPU_RESET, 0) != 822 SIGP_CC_ORDER_CODE_ACCEPTED) 823 return -EIO; 824 825 rc = pcpu_alloc_lowcore(pcpu, cpu); 826 if (rc) 827 return rc; 828 pcpu_prepare_secondary(pcpu, cpu); 829 pcpu_attach_task(pcpu, tidle); 830 pcpu_start_fn(pcpu, smp_start_secondary, NULL); 831 /* Wait until cpu puts itself in the online & active maps */ 832 while (!cpu_online(cpu) || !cpu_active(cpu)) 833 cpu_relax(); 834 return 0; 835 } 836 837 static unsigned int setup_possible_cpus __initdata; 838 839 static int __init _setup_possible_cpus(char *s) 840 { 841 get_option(&s, &setup_possible_cpus); 842 return 0; 843 } 844 early_param("possible_cpus", _setup_possible_cpus); 845 846 #ifdef CONFIG_HOTPLUG_CPU 847 848 int __cpu_disable(void) 849 { 850 unsigned long cregs[16]; 851 852 /* Handle possible pending IPIs */ 853 smp_handle_ext_call(); 854 set_cpu_online(smp_processor_id(), false); 855 /* Disable pseudo page faults on this cpu. */ 856 pfault_fini(); 857 /* Disable interrupt sources via control register. */ 858 __ctl_store(cregs, 0, 15); 859 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */ 860 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */ 861 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */ 862 __ctl_load(cregs, 0, 15); 863 clear_cpu_flag(CIF_NOHZ_DELAY); 864 return 0; 865 } 866 867 void __cpu_die(unsigned int cpu) 868 { 869 struct pcpu *pcpu; 870 871 /* Wait until target cpu is down */ 872 pcpu = pcpu_devices + cpu; 873 while (!pcpu_stopped(pcpu)) 874 cpu_relax(); 875 pcpu_free_lowcore(pcpu); 876 atomic_dec(&init_mm.context.attach_count); 877 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm)); 878 if (MACHINE_HAS_TLB_LC) 879 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask); 880 } 881 882 void __noreturn cpu_die(void) 883 { 884 idle_task_exit(); 885 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0); 886 for (;;) ; 887 } 888 889 #endif /* CONFIG_HOTPLUG_CPU */ 890 891 void __init smp_fill_possible_mask(void) 892 { 893 unsigned int possible, sclp_max, cpu; 894 895 sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1; 896 sclp_max = min(smp_max_threads, sclp_max); 897 sclp_max = sclp.max_cores * sclp_max ?: nr_cpu_ids; 898 possible = setup_possible_cpus ?: nr_cpu_ids; 899 possible = min(possible, sclp_max); 900 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++) 901 set_cpu_possible(cpu, true); 902 } 903 904 void __init smp_prepare_cpus(unsigned int max_cpus) 905 { 906 /* request the 0x1201 emergency signal external interrupt */ 907 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt)) 908 panic("Couldn't request external interrupt 0x1201"); 909 /* request the 0x1202 external call external interrupt */ 910 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt)) 911 panic("Couldn't request external interrupt 0x1202"); 912 smp_detect_cpus(); 913 } 914 915 void __init smp_prepare_boot_cpu(void) 916 { 917 struct pcpu *pcpu = pcpu_devices; 918 919 pcpu->state = CPU_STATE_CONFIGURED; 920 pcpu->address = stap(); 921 pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix(); 922 S390_lowcore.percpu_offset = __per_cpu_offset[0]; 923 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN); 924 set_cpu_present(0, true); 925 set_cpu_online(0, true); 926 } 927 928 void __init smp_cpus_done(unsigned int max_cpus) 929 { 930 } 931 932 void __init smp_setup_processor_id(void) 933 { 934 S390_lowcore.cpu_nr = 0; 935 S390_lowcore.spinlock_lockval = arch_spin_lockval(0); 936 } 937 938 /* 939 * the frequency of the profiling timer can be changed 940 * by writing a multiplier value into /proc/profile. 941 * 942 * usually you want to run this on all CPUs ;) 943 */ 944 int setup_profiling_timer(unsigned int multiplier) 945 { 946 return 0; 947 } 948 949 #ifdef CONFIG_HOTPLUG_CPU 950 static ssize_t cpu_configure_show(struct device *dev, 951 struct device_attribute *attr, char *buf) 952 { 953 ssize_t count; 954 955 mutex_lock(&smp_cpu_state_mutex); 956 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state); 957 mutex_unlock(&smp_cpu_state_mutex); 958 return count; 959 } 960 961 static ssize_t cpu_configure_store(struct device *dev, 962 struct device_attribute *attr, 963 const char *buf, size_t count) 964 { 965 struct pcpu *pcpu; 966 int cpu, val, rc, i; 967 char delim; 968 969 if (sscanf(buf, "%d %c", &val, &delim) != 1) 970 return -EINVAL; 971 if (val != 0 && val != 1) 972 return -EINVAL; 973 get_online_cpus(); 974 mutex_lock(&smp_cpu_state_mutex); 975 rc = -EBUSY; 976 /* disallow configuration changes of online cpus and cpu 0 */ 977 cpu = dev->id; 978 cpu -= cpu % (smp_cpu_mtid + 1); 979 if (cpu == 0) 980 goto out; 981 for (i = 0; i <= smp_cpu_mtid; i++) 982 if (cpu_online(cpu + i)) 983 goto out; 984 pcpu = pcpu_devices + cpu; 985 rc = 0; 986 switch (val) { 987 case 0: 988 if (pcpu->state != CPU_STATE_CONFIGURED) 989 break; 990 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift); 991 if (rc) 992 break; 993 for (i = 0; i <= smp_cpu_mtid; i++) { 994 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i)) 995 continue; 996 pcpu[i].state = CPU_STATE_STANDBY; 997 smp_cpu_set_polarization(cpu + i, 998 POLARIZATION_UNKNOWN); 999 } 1000 topology_expect_change(); 1001 break; 1002 case 1: 1003 if (pcpu->state != CPU_STATE_STANDBY) 1004 break; 1005 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift); 1006 if (rc) 1007 break; 1008 for (i = 0; i <= smp_cpu_mtid; i++) { 1009 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i)) 1010 continue; 1011 pcpu[i].state = CPU_STATE_CONFIGURED; 1012 smp_cpu_set_polarization(cpu + i, 1013 POLARIZATION_UNKNOWN); 1014 } 1015 topology_expect_change(); 1016 break; 1017 default: 1018 break; 1019 } 1020 out: 1021 mutex_unlock(&smp_cpu_state_mutex); 1022 put_online_cpus(); 1023 return rc ? rc : count; 1024 } 1025 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store); 1026 #endif /* CONFIG_HOTPLUG_CPU */ 1027 1028 static ssize_t show_cpu_address(struct device *dev, 1029 struct device_attribute *attr, char *buf) 1030 { 1031 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address); 1032 } 1033 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL); 1034 1035 static struct attribute *cpu_common_attrs[] = { 1036 #ifdef CONFIG_HOTPLUG_CPU 1037 &dev_attr_configure.attr, 1038 #endif 1039 &dev_attr_address.attr, 1040 NULL, 1041 }; 1042 1043 static struct attribute_group cpu_common_attr_group = { 1044 .attrs = cpu_common_attrs, 1045 }; 1046 1047 static struct attribute *cpu_online_attrs[] = { 1048 &dev_attr_idle_count.attr, 1049 &dev_attr_idle_time_us.attr, 1050 NULL, 1051 }; 1052 1053 static struct attribute_group cpu_online_attr_group = { 1054 .attrs = cpu_online_attrs, 1055 }; 1056 1057 static int smp_cpu_notify(struct notifier_block *self, unsigned long action, 1058 void *hcpu) 1059 { 1060 unsigned int cpu = (unsigned int)(long)hcpu; 1061 struct device *s = &per_cpu(cpu_device, cpu)->dev; 1062 int err = 0; 1063 1064 switch (action & ~CPU_TASKS_FROZEN) { 1065 case CPU_ONLINE: 1066 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 1067 break; 1068 case CPU_DEAD: 1069 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 1070 break; 1071 } 1072 return notifier_from_errno(err); 1073 } 1074 1075 static int smp_add_present_cpu(int cpu) 1076 { 1077 struct device *s; 1078 struct cpu *c; 1079 int rc; 1080 1081 c = kzalloc(sizeof(*c), GFP_KERNEL); 1082 if (!c) 1083 return -ENOMEM; 1084 per_cpu(cpu_device, cpu) = c; 1085 s = &c->dev; 1086 c->hotpluggable = 1; 1087 rc = register_cpu(c, cpu); 1088 if (rc) 1089 goto out; 1090 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group); 1091 if (rc) 1092 goto out_cpu; 1093 if (cpu_online(cpu)) { 1094 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 1095 if (rc) 1096 goto out_online; 1097 } 1098 rc = topology_cpu_init(c); 1099 if (rc) 1100 goto out_topology; 1101 return 0; 1102 1103 out_topology: 1104 if (cpu_online(cpu)) 1105 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 1106 out_online: 1107 sysfs_remove_group(&s->kobj, &cpu_common_attr_group); 1108 out_cpu: 1109 #ifdef CONFIG_HOTPLUG_CPU 1110 unregister_cpu(c); 1111 #endif 1112 out: 1113 return rc; 1114 } 1115 1116 #ifdef CONFIG_HOTPLUG_CPU 1117 1118 int __ref smp_rescan_cpus(void) 1119 { 1120 struct sclp_core_info *info; 1121 int nr; 1122 1123 info = smp_get_core_info(); 1124 if (!info) 1125 return -ENOMEM; 1126 get_online_cpus(); 1127 mutex_lock(&smp_cpu_state_mutex); 1128 nr = __smp_rescan_cpus(info, 1); 1129 mutex_unlock(&smp_cpu_state_mutex); 1130 put_online_cpus(); 1131 kfree(info); 1132 if (nr) 1133 topology_schedule_update(); 1134 return 0; 1135 } 1136 1137 static ssize_t __ref rescan_store(struct device *dev, 1138 struct device_attribute *attr, 1139 const char *buf, 1140 size_t count) 1141 { 1142 int rc; 1143 1144 rc = smp_rescan_cpus(); 1145 return rc ? rc : count; 1146 } 1147 static DEVICE_ATTR(rescan, 0200, NULL, rescan_store); 1148 #endif /* CONFIG_HOTPLUG_CPU */ 1149 1150 static int __init s390_smp_init(void) 1151 { 1152 int cpu, rc = 0; 1153 1154 #ifdef CONFIG_HOTPLUG_CPU 1155 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan); 1156 if (rc) 1157 return rc; 1158 #endif 1159 cpu_notifier_register_begin(); 1160 for_each_present_cpu(cpu) { 1161 rc = smp_add_present_cpu(cpu); 1162 if (rc) 1163 goto out; 1164 } 1165 1166 __hotcpu_notifier(smp_cpu_notify, 0); 1167 1168 out: 1169 cpu_notifier_register_done(); 1170 return rc; 1171 } 1172 subsys_initcall(s390_smp_init); 1173