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/diag.h> 37 #include <asm/switch_to.h> 38 #include <asm/facility.h> 39 #include <asm/ipl.h> 40 #include <asm/setup.h> 41 #include <asm/irq.h> 42 #include <asm/tlbflush.h> 43 #include <asm/vtimer.h> 44 #include <asm/lowcore.h> 45 #include <asm/sclp.h> 46 #include <asm/vdso.h> 47 #include <asm/debug.h> 48 #include <asm/os_info.h> 49 #include <asm/sigp.h> 50 #include <asm/idle.h> 51 #include "entry.h" 52 53 enum { 54 ec_schedule = 0, 55 ec_call_function_single, 56 ec_stop_cpu, 57 }; 58 59 enum { 60 CPU_STATE_STANDBY, 61 CPU_STATE_CONFIGURED, 62 }; 63 64 static DEFINE_PER_CPU(struct cpu *, cpu_device); 65 66 struct pcpu { 67 struct lowcore *lowcore; /* lowcore page(s) for the cpu */ 68 unsigned long ec_mask; /* bit mask for ec_xxx functions */ 69 unsigned long ec_clk; /* sigp timestamp for ec_xxx */ 70 signed char state; /* physical cpu state */ 71 signed char polarization; /* physical polarization */ 72 u16 address; /* physical cpu address */ 73 }; 74 75 static u8 boot_core_type; 76 static struct pcpu pcpu_devices[NR_CPUS]; 77 78 unsigned int smp_cpu_mt_shift; 79 EXPORT_SYMBOL(smp_cpu_mt_shift); 80 81 unsigned int smp_cpu_mtid; 82 EXPORT_SYMBOL(smp_cpu_mtid); 83 84 #ifdef CONFIG_CRASH_DUMP 85 __vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS]; 86 #endif 87 88 static unsigned int smp_max_threads __initdata = -1U; 89 90 static int __init early_nosmt(char *s) 91 { 92 smp_max_threads = 1; 93 return 0; 94 } 95 early_param("nosmt", early_nosmt); 96 97 static int __init early_smt(char *s) 98 { 99 get_option(&s, &smp_max_threads); 100 return 0; 101 } 102 early_param("smt", early_smt); 103 104 /* 105 * The smp_cpu_state_mutex must be held when changing the state or polarization 106 * member of a pcpu data structure within the pcpu_devices arreay. 107 */ 108 DEFINE_MUTEX(smp_cpu_state_mutex); 109 110 /* 111 * Signal processor helper functions. 112 */ 113 static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm) 114 { 115 int cc; 116 117 while (1) { 118 cc = __pcpu_sigp(addr, order, parm, NULL); 119 if (cc != SIGP_CC_BUSY) 120 return cc; 121 cpu_relax(); 122 } 123 } 124 125 static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm) 126 { 127 int cc, retry; 128 129 for (retry = 0; ; retry++) { 130 cc = __pcpu_sigp(pcpu->address, order, parm, NULL); 131 if (cc != SIGP_CC_BUSY) 132 break; 133 if (retry >= 3) 134 udelay(10); 135 } 136 return cc; 137 } 138 139 static inline int pcpu_stopped(struct pcpu *pcpu) 140 { 141 u32 uninitialized_var(status); 142 143 if (__pcpu_sigp(pcpu->address, SIGP_SENSE, 144 0, &status) != SIGP_CC_STATUS_STORED) 145 return 0; 146 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED)); 147 } 148 149 static inline int pcpu_running(struct pcpu *pcpu) 150 { 151 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING, 152 0, NULL) != SIGP_CC_STATUS_STORED) 153 return 1; 154 /* Status stored condition code is equivalent to cpu not running. */ 155 return 0; 156 } 157 158 /* 159 * Find struct pcpu by cpu address. 160 */ 161 static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address) 162 { 163 int cpu; 164 165 for_each_cpu(cpu, mask) 166 if (pcpu_devices[cpu].address == address) 167 return pcpu_devices + cpu; 168 return NULL; 169 } 170 171 static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit) 172 { 173 int order; 174 175 if (test_and_set_bit(ec_bit, &pcpu->ec_mask)) 176 return; 177 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL; 178 pcpu->ec_clk = get_tod_clock_fast(); 179 pcpu_sigp_retry(pcpu, order, 0); 180 } 181 182 #define ASYNC_FRAME_OFFSET (ASYNC_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE) 183 #define PANIC_FRAME_OFFSET (PAGE_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE) 184 185 static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu) 186 { 187 unsigned long async_stack, panic_stack; 188 struct lowcore *lc; 189 190 if (pcpu != &pcpu_devices[0]) { 191 pcpu->lowcore = (struct lowcore *) 192 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); 193 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER); 194 panic_stack = __get_free_page(GFP_KERNEL); 195 if (!pcpu->lowcore || !panic_stack || !async_stack) 196 goto out; 197 } else { 198 async_stack = pcpu->lowcore->async_stack - ASYNC_FRAME_OFFSET; 199 panic_stack = pcpu->lowcore->panic_stack - PANIC_FRAME_OFFSET; 200 } 201 lc = pcpu->lowcore; 202 memcpy(lc, &S390_lowcore, 512); 203 memset((char *) lc + 512, 0, sizeof(*lc) - 512); 204 lc->async_stack = async_stack + ASYNC_FRAME_OFFSET; 205 lc->panic_stack = panic_stack + PANIC_FRAME_OFFSET; 206 lc->cpu_nr = cpu; 207 lc->spinlock_lockval = arch_spin_lockval(cpu); 208 if (MACHINE_HAS_VX) 209 lc->vector_save_area_addr = 210 (unsigned long) &lc->vector_save_area; 211 if (vdso_alloc_per_cpu(lc)) 212 goto out; 213 lowcore_ptr[cpu] = lc; 214 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc); 215 return 0; 216 out: 217 if (pcpu != &pcpu_devices[0]) { 218 free_page(panic_stack); 219 free_pages(async_stack, ASYNC_ORDER); 220 free_pages((unsigned long) pcpu->lowcore, LC_ORDER); 221 } 222 return -ENOMEM; 223 } 224 225 #ifdef CONFIG_HOTPLUG_CPU 226 227 static void pcpu_free_lowcore(struct pcpu *pcpu) 228 { 229 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0); 230 lowcore_ptr[pcpu - pcpu_devices] = NULL; 231 vdso_free_per_cpu(pcpu->lowcore); 232 if (pcpu == &pcpu_devices[0]) 233 return; 234 free_page(pcpu->lowcore->panic_stack-PANIC_FRAME_OFFSET); 235 free_pages(pcpu->lowcore->async_stack-ASYNC_FRAME_OFFSET, ASYNC_ORDER); 236 free_pages((unsigned long) pcpu->lowcore, LC_ORDER); 237 } 238 239 #endif /* CONFIG_HOTPLUG_CPU */ 240 241 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu) 242 { 243 struct lowcore *lc = pcpu->lowcore; 244 245 if (MACHINE_HAS_TLB_LC) 246 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask); 247 cpumask_set_cpu(cpu, mm_cpumask(&init_mm)); 248 atomic_inc(&init_mm.context.attach_count); 249 lc->cpu_nr = cpu; 250 lc->spinlock_lockval = arch_spin_lockval(cpu); 251 lc->percpu_offset = __per_cpu_offset[cpu]; 252 lc->kernel_asce = S390_lowcore.kernel_asce; 253 lc->machine_flags = S390_lowcore.machine_flags; 254 lc->user_timer = lc->system_timer = lc->steal_timer = 0; 255 __ctl_store(lc->cregs_save_area, 0, 15); 256 save_access_regs((unsigned int *) lc->access_regs_save_area); 257 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list, 258 MAX_FACILITY_BIT/8); 259 } 260 261 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk) 262 { 263 struct lowcore *lc = pcpu->lowcore; 264 struct thread_info *ti = task_thread_info(tsk); 265 266 lc->kernel_stack = (unsigned long) task_stack_page(tsk) 267 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); 268 lc->thread_info = (unsigned long) task_thread_info(tsk); 269 lc->current_task = (unsigned long) tsk; 270 lc->lpp = LPP_MAGIC; 271 lc->current_pid = tsk->pid; 272 lc->user_timer = ti->user_timer; 273 lc->system_timer = ti->system_timer; 274 lc->steal_timer = 0; 275 } 276 277 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data) 278 { 279 struct lowcore *lc = pcpu->lowcore; 280 281 lc->restart_stack = lc->kernel_stack; 282 lc->restart_fn = (unsigned long) func; 283 lc->restart_data = (unsigned long) data; 284 lc->restart_source = -1UL; 285 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0); 286 } 287 288 /* 289 * Call function via PSW restart on pcpu and stop the current cpu. 290 */ 291 static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *), 292 void *data, unsigned long stack) 293 { 294 struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices]; 295 unsigned long source_cpu = stap(); 296 297 __load_psw_mask(PSW_KERNEL_BITS); 298 if (pcpu->address == source_cpu) 299 func(data); /* should not return */ 300 /* Stop target cpu (if func returns this stops the current cpu). */ 301 pcpu_sigp_retry(pcpu, SIGP_STOP, 0); 302 /* Restart func on the target cpu and stop the current cpu. */ 303 mem_assign_absolute(lc->restart_stack, stack); 304 mem_assign_absolute(lc->restart_fn, (unsigned long) func); 305 mem_assign_absolute(lc->restart_data, (unsigned long) data); 306 mem_assign_absolute(lc->restart_source, source_cpu); 307 asm volatile( 308 "0: sigp 0,%0,%2 # sigp restart to target cpu\n" 309 " brc 2,0b # busy, try again\n" 310 "1: sigp 0,%1,%3 # sigp stop to current cpu\n" 311 " brc 2,1b # busy, try again\n" 312 : : "d" (pcpu->address), "d" (source_cpu), 313 "K" (SIGP_RESTART), "K" (SIGP_STOP) 314 : "0", "1", "cc"); 315 for (;;) ; 316 } 317 318 /* 319 * Enable additional logical cpus for multi-threading. 320 */ 321 static int pcpu_set_smt(unsigned int mtid) 322 { 323 register unsigned long reg1 asm ("1") = (unsigned long) mtid; 324 int cc; 325 326 if (smp_cpu_mtid == mtid) 327 return 0; 328 asm volatile( 329 " sigp %1,0,%2 # sigp set multi-threading\n" 330 " ipm %0\n" 331 " srl %0,28\n" 332 : "=d" (cc) : "d" (reg1), "K" (SIGP_SET_MULTI_THREADING) 333 : "cc"); 334 if (cc == 0) { 335 smp_cpu_mtid = mtid; 336 smp_cpu_mt_shift = 0; 337 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift)) 338 smp_cpu_mt_shift++; 339 pcpu_devices[0].address = stap(); 340 } 341 return cc; 342 } 343 344 /* 345 * Call function on an online CPU. 346 */ 347 void smp_call_online_cpu(void (*func)(void *), void *data) 348 { 349 struct pcpu *pcpu; 350 351 /* Use the current cpu if it is online. */ 352 pcpu = pcpu_find_address(cpu_online_mask, stap()); 353 if (!pcpu) 354 /* Use the first online cpu. */ 355 pcpu = pcpu_devices + cpumask_first(cpu_online_mask); 356 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack); 357 } 358 359 /* 360 * Call function on the ipl CPU. 361 */ 362 void smp_call_ipl_cpu(void (*func)(void *), void *data) 363 { 364 pcpu_delegate(&pcpu_devices[0], func, data, 365 pcpu_devices->lowcore->panic_stack - 366 PANIC_FRAME_OFFSET + PAGE_SIZE); 367 } 368 369 int smp_find_processor_id(u16 address) 370 { 371 int cpu; 372 373 for_each_present_cpu(cpu) 374 if (pcpu_devices[cpu].address == address) 375 return cpu; 376 return -1; 377 } 378 379 int smp_vcpu_scheduled(int cpu) 380 { 381 return pcpu_running(pcpu_devices + cpu); 382 } 383 384 void smp_yield_cpu(int cpu) 385 { 386 if (MACHINE_HAS_DIAG9C) { 387 diag_stat_inc_norecursion(DIAG_STAT_X09C); 388 asm volatile("diag %0,0,0x9c" 389 : : "d" (pcpu_devices[cpu].address)); 390 } else if (MACHINE_HAS_DIAG44) { 391 diag_stat_inc_norecursion(DIAG_STAT_X044); 392 asm volatile("diag 0,0,0x44"); 393 } 394 } 395 396 /* 397 * Send cpus emergency shutdown signal. This gives the cpus the 398 * opportunity to complete outstanding interrupts. 399 */ 400 static void smp_emergency_stop(cpumask_t *cpumask) 401 { 402 u64 end; 403 int cpu; 404 405 end = get_tod_clock() + (1000000UL << 12); 406 for_each_cpu(cpu, cpumask) { 407 struct pcpu *pcpu = pcpu_devices + cpu; 408 set_bit(ec_stop_cpu, &pcpu->ec_mask); 409 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL, 410 0, NULL) == SIGP_CC_BUSY && 411 get_tod_clock() < end) 412 cpu_relax(); 413 } 414 while (get_tod_clock() < end) { 415 for_each_cpu(cpu, cpumask) 416 if (pcpu_stopped(pcpu_devices + cpu)) 417 cpumask_clear_cpu(cpu, cpumask); 418 if (cpumask_empty(cpumask)) 419 break; 420 cpu_relax(); 421 } 422 } 423 424 /* 425 * Stop all cpus but the current one. 426 */ 427 void smp_send_stop(void) 428 { 429 cpumask_t cpumask; 430 int cpu; 431 432 /* Disable all interrupts/machine checks */ 433 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); 434 trace_hardirqs_off(); 435 436 debug_set_critical(); 437 cpumask_copy(&cpumask, cpu_online_mask); 438 cpumask_clear_cpu(smp_processor_id(), &cpumask); 439 440 if (oops_in_progress) 441 smp_emergency_stop(&cpumask); 442 443 /* stop all processors */ 444 for_each_cpu(cpu, &cpumask) { 445 struct pcpu *pcpu = pcpu_devices + cpu; 446 pcpu_sigp_retry(pcpu, SIGP_STOP, 0); 447 while (!pcpu_stopped(pcpu)) 448 cpu_relax(); 449 } 450 } 451 452 /* 453 * This is the main routine where commands issued by other 454 * cpus are handled. 455 */ 456 static void smp_handle_ext_call(void) 457 { 458 unsigned long bits; 459 460 /* handle bit signal external calls */ 461 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0); 462 if (test_bit(ec_stop_cpu, &bits)) 463 smp_stop_cpu(); 464 if (test_bit(ec_schedule, &bits)) 465 scheduler_ipi(); 466 if (test_bit(ec_call_function_single, &bits)) 467 generic_smp_call_function_single_interrupt(); 468 } 469 470 static void do_ext_call_interrupt(struct ext_code ext_code, 471 unsigned int param32, unsigned long param64) 472 { 473 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS); 474 smp_handle_ext_call(); 475 } 476 477 void arch_send_call_function_ipi_mask(const struct cpumask *mask) 478 { 479 int cpu; 480 481 for_each_cpu(cpu, mask) 482 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); 483 } 484 485 void arch_send_call_function_single_ipi(int cpu) 486 { 487 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); 488 } 489 490 /* 491 * this function sends a 'reschedule' IPI to another CPU. 492 * it goes straight through and wastes no time serializing 493 * anything. Worst case is that we lose a reschedule ... 494 */ 495 void smp_send_reschedule(int cpu) 496 { 497 pcpu_ec_call(pcpu_devices + cpu, ec_schedule); 498 } 499 500 /* 501 * parameter area for the set/clear control bit callbacks 502 */ 503 struct ec_creg_mask_parms { 504 unsigned long orval; 505 unsigned long andval; 506 int cr; 507 }; 508 509 /* 510 * callback for setting/clearing control bits 511 */ 512 static void smp_ctl_bit_callback(void *info) 513 { 514 struct ec_creg_mask_parms *pp = info; 515 unsigned long cregs[16]; 516 517 __ctl_store(cregs, 0, 15); 518 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval; 519 __ctl_load(cregs, 0, 15); 520 } 521 522 /* 523 * Set a bit in a control register of all cpus 524 */ 525 void smp_ctl_set_bit(int cr, int bit) 526 { 527 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr }; 528 529 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 530 } 531 EXPORT_SYMBOL(smp_ctl_set_bit); 532 533 /* 534 * Clear a bit in a control register of all cpus 535 */ 536 void smp_ctl_clear_bit(int cr, int bit) 537 { 538 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr }; 539 540 on_each_cpu(smp_ctl_bit_callback, &parms, 1); 541 } 542 EXPORT_SYMBOL(smp_ctl_clear_bit); 543 544 #ifdef CONFIG_CRASH_DUMP 545 546 int smp_store_status(int cpu) 547 { 548 struct pcpu *pcpu = pcpu_devices + cpu; 549 unsigned long pa; 550 551 pa = __pa(&pcpu->lowcore->floating_pt_save_area); 552 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS, 553 pa) != SIGP_CC_ORDER_CODE_ACCEPTED) 554 return -EIO; 555 if (!MACHINE_HAS_VX) 556 return 0; 557 pa = __pa(pcpu->lowcore->vector_save_area_addr); 558 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS, 559 pa) != SIGP_CC_ORDER_CODE_ACCEPTED) 560 return -EIO; 561 return 0; 562 } 563 564 /* 565 * Collect CPU state of the previous, crashed system. 566 * There are four cases: 567 * 1) standard zfcp dump 568 * condition: OLDMEM_BASE == NULL && ipl_info.type == IPL_TYPE_FCP_DUMP 569 * The state for all CPUs except the boot CPU needs to be collected 570 * with sigp stop-and-store-status. The boot CPU state is located in 571 * the absolute lowcore of the memory stored in the HSA. The zcore code 572 * will copy the boot CPU state from the HSA. 573 * 2) stand-alone kdump for SCSI (zfcp dump with swapped memory) 574 * condition: OLDMEM_BASE != NULL && ipl_info.type == IPL_TYPE_FCP_DUMP 575 * The state for all CPUs except the boot CPU needs to be collected 576 * with sigp stop-and-store-status. The firmware or the boot-loader 577 * stored the registers of the boot CPU in the absolute lowcore in the 578 * memory of the old system. 579 * 3) kdump and the old kernel did not store the CPU state, 580 * or stand-alone kdump for DASD 581 * condition: OLDMEM_BASE != NULL && !is_kdump_kernel() 582 * The state for all CPUs except the boot CPU needs to be collected 583 * with sigp stop-and-store-status. The kexec code or the boot-loader 584 * stored the registers of the boot CPU in the memory of the old system. 585 * 4) kdump and the old kernel stored the CPU state 586 * condition: OLDMEM_BASE != NULL && is_kdump_kernel() 587 * This case does not exist for s390 anymore, setup_arch explicitly 588 * deactivates the elfcorehdr= kernel parameter 589 */ 590 static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr, 591 bool is_boot_cpu, unsigned long page) 592 { 593 __vector128 *vxrs = (__vector128 *) page; 594 595 if (is_boot_cpu) 596 vxrs = boot_cpu_vector_save_area; 597 else 598 __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page); 599 save_area_add_vxrs(sa, vxrs); 600 } 601 602 static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr, 603 bool is_boot_cpu, unsigned long page) 604 { 605 void *regs = (void *) page; 606 607 if (is_boot_cpu) 608 copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512); 609 else 610 __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page); 611 save_area_add_regs(sa, regs); 612 } 613 614 void __init smp_save_dump_cpus(void) 615 { 616 int addr, boot_cpu_addr, max_cpu_addr; 617 struct save_area *sa; 618 unsigned long page; 619 bool is_boot_cpu; 620 621 if (!(OLDMEM_BASE || ipl_info.type == IPL_TYPE_FCP_DUMP)) 622 /* No previous system present, normal boot. */ 623 return; 624 /* Allocate a page as dumping area for the store status sigps */ 625 page = memblock_alloc_base(PAGE_SIZE, PAGE_SIZE, 1UL << 31); 626 /* Set multi-threading state to the previous system. */ 627 pcpu_set_smt(sclp.mtid_prev); 628 boot_cpu_addr = stap(); 629 max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev; 630 for (addr = 0; addr <= max_cpu_addr; addr++) { 631 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) == 632 SIGP_CC_NOT_OPERATIONAL) 633 continue; 634 is_boot_cpu = (addr == boot_cpu_addr); 635 /* Allocate save area */ 636 sa = save_area_alloc(is_boot_cpu); 637 if (!sa) 638 panic("could not allocate memory for save area\n"); 639 if (MACHINE_HAS_VX) 640 /* Get the vector registers */ 641 smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page); 642 /* 643 * For a zfcp dump OLDMEM_BASE == NULL and the registers 644 * of the boot CPU are stored in the HSA. To retrieve 645 * these registers an SCLP request is required which is 646 * done by drivers/s390/char/zcore.c:init_cpu_info() 647 */ 648 if (!is_boot_cpu || OLDMEM_BASE) 649 /* Get the CPU registers */ 650 smp_save_cpu_regs(sa, addr, is_boot_cpu, page); 651 } 652 memblock_free(page, PAGE_SIZE); 653 diag308_reset(); 654 pcpu_set_smt(0); 655 } 656 #endif /* CONFIG_CRASH_DUMP */ 657 658 void smp_cpu_set_polarization(int cpu, int val) 659 { 660 pcpu_devices[cpu].polarization = val; 661 } 662 663 int smp_cpu_get_polarization(int cpu) 664 { 665 return pcpu_devices[cpu].polarization; 666 } 667 668 static struct sclp_core_info *smp_get_core_info(void) 669 { 670 static int use_sigp_detection; 671 struct sclp_core_info *info; 672 int address; 673 674 info = kzalloc(sizeof(*info), GFP_KERNEL); 675 if (info && (use_sigp_detection || sclp_get_core_info(info))) { 676 use_sigp_detection = 1; 677 for (address = 0; 678 address < (SCLP_MAX_CORES << smp_cpu_mt_shift); 679 address += (1U << smp_cpu_mt_shift)) { 680 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) == 681 SIGP_CC_NOT_OPERATIONAL) 682 continue; 683 info->core[info->configured].core_id = 684 address >> smp_cpu_mt_shift; 685 info->configured++; 686 } 687 info->combined = info->configured; 688 } 689 return info; 690 } 691 692 static int smp_add_present_cpu(int cpu); 693 694 static int __smp_rescan_cpus(struct sclp_core_info *info, int sysfs_add) 695 { 696 struct pcpu *pcpu; 697 cpumask_t avail; 698 int cpu, nr, i, j; 699 u16 address; 700 701 nr = 0; 702 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask); 703 cpu = cpumask_first(&avail); 704 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) { 705 if (sclp.has_core_type && info->core[i].type != boot_core_type) 706 continue; 707 address = info->core[i].core_id << smp_cpu_mt_shift; 708 for (j = 0; j <= smp_cpu_mtid; j++) { 709 if (pcpu_find_address(cpu_present_mask, address + j)) 710 continue; 711 pcpu = pcpu_devices + cpu; 712 pcpu->address = address + j; 713 pcpu->state = 714 (cpu >= info->configured*(smp_cpu_mtid + 1)) ? 715 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED; 716 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 717 set_cpu_present(cpu, true); 718 if (sysfs_add && smp_add_present_cpu(cpu) != 0) 719 set_cpu_present(cpu, false); 720 else 721 nr++; 722 cpu = cpumask_next(cpu, &avail); 723 if (cpu >= nr_cpu_ids) 724 break; 725 } 726 } 727 return nr; 728 } 729 730 static void __init smp_detect_cpus(void) 731 { 732 unsigned int cpu, mtid, c_cpus, s_cpus; 733 struct sclp_core_info *info; 734 u16 address; 735 736 /* Get CPU information */ 737 info = smp_get_core_info(); 738 if (!info) 739 panic("smp_detect_cpus failed to allocate memory\n"); 740 741 /* Find boot CPU type */ 742 if (sclp.has_core_type) { 743 address = stap(); 744 for (cpu = 0; cpu < info->combined; cpu++) 745 if (info->core[cpu].core_id == address) { 746 /* The boot cpu dictates the cpu type. */ 747 boot_core_type = info->core[cpu].type; 748 break; 749 } 750 if (cpu >= info->combined) 751 panic("Could not find boot CPU type"); 752 } 753 754 /* Set multi-threading state for the current system */ 755 mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp; 756 mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1; 757 pcpu_set_smt(mtid); 758 759 /* Print number of CPUs */ 760 c_cpus = s_cpus = 0; 761 for (cpu = 0; cpu < info->combined; cpu++) { 762 if (sclp.has_core_type && 763 info->core[cpu].type != boot_core_type) 764 continue; 765 if (cpu < info->configured) 766 c_cpus += smp_cpu_mtid + 1; 767 else 768 s_cpus += smp_cpu_mtid + 1; 769 } 770 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus); 771 772 /* Add CPUs present at boot */ 773 get_online_cpus(); 774 __smp_rescan_cpus(info, 0); 775 put_online_cpus(); 776 kfree(info); 777 } 778 779 /* 780 * Activate a secondary processor. 781 */ 782 static void smp_start_secondary(void *cpuvoid) 783 { 784 S390_lowcore.last_update_clock = get_tod_clock(); 785 S390_lowcore.restart_stack = (unsigned long) restart_stack; 786 S390_lowcore.restart_fn = (unsigned long) do_restart; 787 S390_lowcore.restart_data = 0; 788 S390_lowcore.restart_source = -1UL; 789 restore_access_regs(S390_lowcore.access_regs_save_area); 790 __ctl_load(S390_lowcore.cregs_save_area, 0, 15); 791 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); 792 cpu_init(); 793 preempt_disable(); 794 init_cpu_timer(); 795 vtime_init(); 796 pfault_init(); 797 notify_cpu_starting(smp_processor_id()); 798 set_cpu_online(smp_processor_id(), true); 799 inc_irq_stat(CPU_RST); 800 local_irq_enable(); 801 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); 802 } 803 804 /* Upping and downing of CPUs */ 805 int __cpu_up(unsigned int cpu, struct task_struct *tidle) 806 { 807 struct pcpu *pcpu; 808 int base, i, rc; 809 810 pcpu = pcpu_devices + cpu; 811 if (pcpu->state != CPU_STATE_CONFIGURED) 812 return -EIO; 813 base = cpu - (cpu % (smp_cpu_mtid + 1)); 814 for (i = 0; i <= smp_cpu_mtid; i++) { 815 if (base + i < nr_cpu_ids) 816 if (cpu_online(base + i)) 817 break; 818 } 819 /* 820 * If this is the first CPU of the core to get online 821 * do an initial CPU reset. 822 */ 823 if (i > smp_cpu_mtid && 824 pcpu_sigp_retry(pcpu_devices + base, SIGP_INITIAL_CPU_RESET, 0) != 825 SIGP_CC_ORDER_CODE_ACCEPTED) 826 return -EIO; 827 828 rc = pcpu_alloc_lowcore(pcpu, cpu); 829 if (rc) 830 return rc; 831 pcpu_prepare_secondary(pcpu, cpu); 832 pcpu_attach_task(pcpu, tidle); 833 pcpu_start_fn(pcpu, smp_start_secondary, NULL); 834 /* Wait until cpu puts itself in the online & active maps */ 835 while (!cpu_online(cpu) || !cpu_active(cpu)) 836 cpu_relax(); 837 return 0; 838 } 839 840 static unsigned int setup_possible_cpus __initdata; 841 842 static int __init _setup_possible_cpus(char *s) 843 { 844 get_option(&s, &setup_possible_cpus); 845 return 0; 846 } 847 early_param("possible_cpus", _setup_possible_cpus); 848 849 #ifdef CONFIG_HOTPLUG_CPU 850 851 int __cpu_disable(void) 852 { 853 unsigned long cregs[16]; 854 855 /* Handle possible pending IPIs */ 856 smp_handle_ext_call(); 857 set_cpu_online(smp_processor_id(), false); 858 /* Disable pseudo page faults on this cpu. */ 859 pfault_fini(); 860 /* Disable interrupt sources via control register. */ 861 __ctl_store(cregs, 0, 15); 862 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */ 863 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */ 864 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */ 865 __ctl_load(cregs, 0, 15); 866 clear_cpu_flag(CIF_NOHZ_DELAY); 867 return 0; 868 } 869 870 void __cpu_die(unsigned int cpu) 871 { 872 struct pcpu *pcpu; 873 874 /* Wait until target cpu is down */ 875 pcpu = pcpu_devices + cpu; 876 while (!pcpu_stopped(pcpu)) 877 cpu_relax(); 878 pcpu_free_lowcore(pcpu); 879 atomic_dec(&init_mm.context.attach_count); 880 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm)); 881 if (MACHINE_HAS_TLB_LC) 882 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask); 883 } 884 885 void __noreturn cpu_die(void) 886 { 887 idle_task_exit(); 888 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0); 889 for (;;) ; 890 } 891 892 #endif /* CONFIG_HOTPLUG_CPU */ 893 894 void __init smp_fill_possible_mask(void) 895 { 896 unsigned int possible, sclp_max, cpu; 897 898 sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1; 899 sclp_max = min(smp_max_threads, sclp_max); 900 sclp_max = sclp.max_cores * sclp_max ?: nr_cpu_ids; 901 possible = setup_possible_cpus ?: nr_cpu_ids; 902 possible = min(possible, sclp_max); 903 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++) 904 set_cpu_possible(cpu, true); 905 } 906 907 void __init smp_prepare_cpus(unsigned int max_cpus) 908 { 909 /* request the 0x1201 emergency signal external interrupt */ 910 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt)) 911 panic("Couldn't request external interrupt 0x1201"); 912 /* request the 0x1202 external call external interrupt */ 913 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt)) 914 panic("Couldn't request external interrupt 0x1202"); 915 smp_detect_cpus(); 916 } 917 918 void __init smp_prepare_boot_cpu(void) 919 { 920 struct pcpu *pcpu = pcpu_devices; 921 922 pcpu->state = CPU_STATE_CONFIGURED; 923 pcpu->address = stap(); 924 pcpu->lowcore = (struct lowcore *)(unsigned long) store_prefix(); 925 S390_lowcore.percpu_offset = __per_cpu_offset[0]; 926 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN); 927 set_cpu_present(0, true); 928 set_cpu_online(0, true); 929 } 930 931 void __init smp_cpus_done(unsigned int max_cpus) 932 { 933 } 934 935 void __init smp_setup_processor_id(void) 936 { 937 S390_lowcore.cpu_nr = 0; 938 S390_lowcore.spinlock_lockval = arch_spin_lockval(0); 939 } 940 941 /* 942 * the frequency of the profiling timer can be changed 943 * by writing a multiplier value into /proc/profile. 944 * 945 * usually you want to run this on all CPUs ;) 946 */ 947 int setup_profiling_timer(unsigned int multiplier) 948 { 949 return 0; 950 } 951 952 #ifdef CONFIG_HOTPLUG_CPU 953 static ssize_t cpu_configure_show(struct device *dev, 954 struct device_attribute *attr, char *buf) 955 { 956 ssize_t count; 957 958 mutex_lock(&smp_cpu_state_mutex); 959 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state); 960 mutex_unlock(&smp_cpu_state_mutex); 961 return count; 962 } 963 964 static ssize_t cpu_configure_store(struct device *dev, 965 struct device_attribute *attr, 966 const char *buf, size_t count) 967 { 968 struct pcpu *pcpu; 969 int cpu, val, rc, i; 970 char delim; 971 972 if (sscanf(buf, "%d %c", &val, &delim) != 1) 973 return -EINVAL; 974 if (val != 0 && val != 1) 975 return -EINVAL; 976 get_online_cpus(); 977 mutex_lock(&smp_cpu_state_mutex); 978 rc = -EBUSY; 979 /* disallow configuration changes of online cpus and cpu 0 */ 980 cpu = dev->id; 981 cpu -= cpu % (smp_cpu_mtid + 1); 982 if (cpu == 0) 983 goto out; 984 for (i = 0; i <= smp_cpu_mtid; i++) 985 if (cpu_online(cpu + i)) 986 goto out; 987 pcpu = pcpu_devices + cpu; 988 rc = 0; 989 switch (val) { 990 case 0: 991 if (pcpu->state != CPU_STATE_CONFIGURED) 992 break; 993 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift); 994 if (rc) 995 break; 996 for (i = 0; i <= smp_cpu_mtid; i++) { 997 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i)) 998 continue; 999 pcpu[i].state = CPU_STATE_STANDBY; 1000 smp_cpu_set_polarization(cpu + i, 1001 POLARIZATION_UNKNOWN); 1002 } 1003 topology_expect_change(); 1004 break; 1005 case 1: 1006 if (pcpu->state != CPU_STATE_STANDBY) 1007 break; 1008 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift); 1009 if (rc) 1010 break; 1011 for (i = 0; i <= smp_cpu_mtid; i++) { 1012 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i)) 1013 continue; 1014 pcpu[i].state = CPU_STATE_CONFIGURED; 1015 smp_cpu_set_polarization(cpu + i, 1016 POLARIZATION_UNKNOWN); 1017 } 1018 topology_expect_change(); 1019 break; 1020 default: 1021 break; 1022 } 1023 out: 1024 mutex_unlock(&smp_cpu_state_mutex); 1025 put_online_cpus(); 1026 return rc ? rc : count; 1027 } 1028 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store); 1029 #endif /* CONFIG_HOTPLUG_CPU */ 1030 1031 static ssize_t show_cpu_address(struct device *dev, 1032 struct device_attribute *attr, char *buf) 1033 { 1034 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address); 1035 } 1036 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL); 1037 1038 static struct attribute *cpu_common_attrs[] = { 1039 #ifdef CONFIG_HOTPLUG_CPU 1040 &dev_attr_configure.attr, 1041 #endif 1042 &dev_attr_address.attr, 1043 NULL, 1044 }; 1045 1046 static struct attribute_group cpu_common_attr_group = { 1047 .attrs = cpu_common_attrs, 1048 }; 1049 1050 static struct attribute *cpu_online_attrs[] = { 1051 &dev_attr_idle_count.attr, 1052 &dev_attr_idle_time_us.attr, 1053 NULL, 1054 }; 1055 1056 static struct attribute_group cpu_online_attr_group = { 1057 .attrs = cpu_online_attrs, 1058 }; 1059 1060 static int smp_cpu_notify(struct notifier_block *self, unsigned long action, 1061 void *hcpu) 1062 { 1063 unsigned int cpu = (unsigned int)(long)hcpu; 1064 struct device *s = &per_cpu(cpu_device, cpu)->dev; 1065 int err = 0; 1066 1067 switch (action & ~CPU_TASKS_FROZEN) { 1068 case CPU_ONLINE: 1069 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 1070 break; 1071 case CPU_DEAD: 1072 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 1073 break; 1074 } 1075 return notifier_from_errno(err); 1076 } 1077 1078 static int smp_add_present_cpu(int cpu) 1079 { 1080 struct device *s; 1081 struct cpu *c; 1082 int rc; 1083 1084 c = kzalloc(sizeof(*c), GFP_KERNEL); 1085 if (!c) 1086 return -ENOMEM; 1087 per_cpu(cpu_device, cpu) = c; 1088 s = &c->dev; 1089 c->hotpluggable = 1; 1090 rc = register_cpu(c, cpu); 1091 if (rc) 1092 goto out; 1093 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group); 1094 if (rc) 1095 goto out_cpu; 1096 if (cpu_online(cpu)) { 1097 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group); 1098 if (rc) 1099 goto out_online; 1100 } 1101 rc = topology_cpu_init(c); 1102 if (rc) 1103 goto out_topology; 1104 return 0; 1105 1106 out_topology: 1107 if (cpu_online(cpu)) 1108 sysfs_remove_group(&s->kobj, &cpu_online_attr_group); 1109 out_online: 1110 sysfs_remove_group(&s->kobj, &cpu_common_attr_group); 1111 out_cpu: 1112 #ifdef CONFIG_HOTPLUG_CPU 1113 unregister_cpu(c); 1114 #endif 1115 out: 1116 return rc; 1117 } 1118 1119 #ifdef CONFIG_HOTPLUG_CPU 1120 1121 int __ref smp_rescan_cpus(void) 1122 { 1123 struct sclp_core_info *info; 1124 int nr; 1125 1126 info = smp_get_core_info(); 1127 if (!info) 1128 return -ENOMEM; 1129 get_online_cpus(); 1130 mutex_lock(&smp_cpu_state_mutex); 1131 nr = __smp_rescan_cpus(info, 1); 1132 mutex_unlock(&smp_cpu_state_mutex); 1133 put_online_cpus(); 1134 kfree(info); 1135 if (nr) 1136 topology_schedule_update(); 1137 return 0; 1138 } 1139 1140 static ssize_t __ref rescan_store(struct device *dev, 1141 struct device_attribute *attr, 1142 const char *buf, 1143 size_t count) 1144 { 1145 int rc; 1146 1147 rc = smp_rescan_cpus(); 1148 return rc ? rc : count; 1149 } 1150 static DEVICE_ATTR(rescan, 0200, NULL, rescan_store); 1151 #endif /* CONFIG_HOTPLUG_CPU */ 1152 1153 static int __init s390_smp_init(void) 1154 { 1155 int cpu, rc = 0; 1156 1157 #ifdef CONFIG_HOTPLUG_CPU 1158 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan); 1159 if (rc) 1160 return rc; 1161 #endif 1162 cpu_notifier_register_begin(); 1163 for_each_present_cpu(cpu) { 1164 rc = smp_add_present_cpu(cpu); 1165 if (rc) 1166 goto out; 1167 } 1168 1169 __hotcpu_notifier(smp_cpu_notify, 0); 1170 1171 out: 1172 cpu_notifier_register_done(); 1173 return rc; 1174 } 1175 subsys_initcall(s390_smp_init); 1176