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