| 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 "entry.h" |
| 49 | |
| 50 | enum { |
| 51 | ec_schedule = 0, |
| 52 | ec_call_function, |
| 53 | ec_call_function_single, |
| 54 | ec_stop_cpu, |
| 55 | }; |
| 56 | |
| 57 | enum { |
| 58 | CPU_STATE_STANDBY, |
| 59 | CPU_STATE_CONFIGURED, |
| 60 | }; |
| 61 | |
| 62 | struct pcpu { |
| 63 | struct cpu cpu; |
| 64 | struct _lowcore *lowcore; /* lowcore page(s) for the cpu */ |
| 65 | unsigned long async_stack; /* async stack for the cpu */ |
| 66 | unsigned long panic_stack; /* panic stack for the cpu */ |
| 67 | unsigned long ec_mask; /* bit mask for ec_xxx functions */ |
| 68 | int state; /* physical cpu state */ |
| 69 | int polarization; /* physical polarization */ |
| 70 | u16 address; /* physical cpu address */ |
| 71 | }; |
| 72 | |
| 73 | static u8 boot_cpu_type; |
| 74 | static u16 boot_cpu_address; |
| 75 | static struct pcpu pcpu_devices[NR_CPUS]; |
| 76 | |
| 77 | /* |
| 78 | * The smp_cpu_state_mutex must be held when changing the state or polarization |
| 79 | * member of a pcpu data structure within the pcpu_devices arreay. |
| 80 | */ |
| 81 | DEFINE_MUTEX(smp_cpu_state_mutex); |
| 82 | |
| 83 | /* |
| 84 | * Signal processor helper functions. |
| 85 | */ |
| 86 | static inline int __pcpu_sigp(u16 addr, u8 order, u32 parm, u32 *status) |
| 87 | { |
| 88 | register unsigned int reg1 asm ("1") = parm; |
| 89 | int cc; |
| 90 | |
| 91 | asm volatile( |
| 92 | " sigp %1,%2,0(%3)\n" |
| 93 | " ipm %0\n" |
| 94 | " srl %0,28\n" |
| 95 | : "=d" (cc), "+d" (reg1) : "d" (addr), "a" (order) : "cc"); |
| 96 | if (status && cc == 1) |
| 97 | *status = reg1; |
| 98 | return cc; |
| 99 | } |
| 100 | |
| 101 | static inline int __pcpu_sigp_relax(u16 addr, u8 order, u32 parm, u32 *status) |
| 102 | { |
| 103 | int cc; |
| 104 | |
| 105 | while (1) { |
| 106 | cc = __pcpu_sigp(addr, order, parm, NULL); |
| 107 | if (cc != SIGP_CC_BUSY) |
| 108 | return cc; |
| 109 | cpu_relax(); |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm) |
| 114 | { |
| 115 | int cc, retry; |
| 116 | |
| 117 | for (retry = 0; ; retry++) { |
| 118 | cc = __pcpu_sigp(pcpu->address, order, parm, NULL); |
| 119 | if (cc != SIGP_CC_BUSY) |
| 120 | break; |
| 121 | if (retry >= 3) |
| 122 | udelay(10); |
| 123 | } |
| 124 | return cc; |
| 125 | } |
| 126 | |
| 127 | static inline int pcpu_stopped(struct pcpu *pcpu) |
| 128 | { |
| 129 | u32 uninitialized_var(status); |
| 130 | |
| 131 | if (__pcpu_sigp(pcpu->address, SIGP_SENSE, |
| 132 | 0, &status) != SIGP_CC_STATUS_STORED) |
| 133 | return 0; |
| 134 | return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED)); |
| 135 | } |
| 136 | |
| 137 | static inline int pcpu_running(struct pcpu *pcpu) |
| 138 | { |
| 139 | if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING, |
| 140 | 0, NULL) != SIGP_CC_STATUS_STORED) |
| 141 | return 1; |
| 142 | /* Status stored condition code is equivalent to cpu not running. */ |
| 143 | return 0; |
| 144 | } |
| 145 | |
| 146 | /* |
| 147 | * Find struct pcpu by cpu address. |
| 148 | */ |
| 149 | static struct pcpu *pcpu_find_address(const struct cpumask *mask, int address) |
| 150 | { |
| 151 | int cpu; |
| 152 | |
| 153 | for_each_cpu(cpu, mask) |
| 154 | if (pcpu_devices[cpu].address == address) |
| 155 | return pcpu_devices + cpu; |
| 156 | return NULL; |
| 157 | } |
| 158 | |
| 159 | static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit) |
| 160 | { |
| 161 | int order; |
| 162 | |
| 163 | set_bit(ec_bit, &pcpu->ec_mask); |
| 164 | order = pcpu_running(pcpu) ? |
| 165 | SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL; |
| 166 | pcpu_sigp_retry(pcpu, order, 0); |
| 167 | } |
| 168 | |
| 169 | static int __cpuinit pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu) |
| 170 | { |
| 171 | struct _lowcore *lc; |
| 172 | |
| 173 | if (pcpu != &pcpu_devices[0]) { |
| 174 | pcpu->lowcore = (struct _lowcore *) |
| 175 | __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); |
| 176 | pcpu->async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER); |
| 177 | pcpu->panic_stack = __get_free_page(GFP_KERNEL); |
| 178 | if (!pcpu->lowcore || !pcpu->panic_stack || !pcpu->async_stack) |
| 179 | goto out; |
| 180 | } |
| 181 | lc = pcpu->lowcore; |
| 182 | memcpy(lc, &S390_lowcore, 512); |
| 183 | memset((char *) lc + 512, 0, sizeof(*lc) - 512); |
| 184 | lc->async_stack = pcpu->async_stack + ASYNC_SIZE; |
| 185 | lc->panic_stack = pcpu->panic_stack + PAGE_SIZE; |
| 186 | lc->cpu_nr = cpu; |
| 187 | #ifndef CONFIG_64BIT |
| 188 | if (MACHINE_HAS_IEEE) { |
| 189 | lc->extended_save_area_addr = get_zeroed_page(GFP_KERNEL); |
| 190 | if (!lc->extended_save_area_addr) |
| 191 | goto out; |
| 192 | } |
| 193 | #else |
| 194 | if (vdso_alloc_per_cpu(lc)) |
| 195 | goto out; |
| 196 | #endif |
| 197 | lowcore_ptr[cpu] = lc; |
| 198 | pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc); |
| 199 | return 0; |
| 200 | out: |
| 201 | if (pcpu != &pcpu_devices[0]) { |
| 202 | free_page(pcpu->panic_stack); |
| 203 | free_pages(pcpu->async_stack, ASYNC_ORDER); |
| 204 | free_pages((unsigned long) pcpu->lowcore, LC_ORDER); |
| 205 | } |
| 206 | return -ENOMEM; |
| 207 | } |
| 208 | |
| 209 | #ifdef CONFIG_HOTPLUG_CPU |
| 210 | |
| 211 | static void pcpu_free_lowcore(struct pcpu *pcpu) |
| 212 | { |
| 213 | pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0); |
| 214 | lowcore_ptr[pcpu - pcpu_devices] = NULL; |
| 215 | #ifndef CONFIG_64BIT |
| 216 | if (MACHINE_HAS_IEEE) { |
| 217 | struct _lowcore *lc = pcpu->lowcore; |
| 218 | |
| 219 | free_page((unsigned long) lc->extended_save_area_addr); |
| 220 | lc->extended_save_area_addr = 0; |
| 221 | } |
| 222 | #else |
| 223 | vdso_free_per_cpu(pcpu->lowcore); |
| 224 | #endif |
| 225 | if (pcpu != &pcpu_devices[0]) { |
| 226 | free_page(pcpu->panic_stack); |
| 227 | free_pages(pcpu->async_stack, ASYNC_ORDER); |
| 228 | free_pages((unsigned long) pcpu->lowcore, LC_ORDER); |
| 229 | } |
| 230 | } |
| 231 | |
| 232 | #endif /* CONFIG_HOTPLUG_CPU */ |
| 233 | |
| 234 | static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu) |
| 235 | { |
| 236 | struct _lowcore *lc = pcpu->lowcore; |
| 237 | |
| 238 | atomic_inc(&init_mm.context.attach_count); |
| 239 | lc->cpu_nr = cpu; |
| 240 | lc->percpu_offset = __per_cpu_offset[cpu]; |
| 241 | lc->kernel_asce = S390_lowcore.kernel_asce; |
| 242 | lc->machine_flags = S390_lowcore.machine_flags; |
| 243 | lc->ftrace_func = S390_lowcore.ftrace_func; |
| 244 | lc->user_timer = lc->system_timer = lc->steal_timer = 0; |
| 245 | __ctl_store(lc->cregs_save_area, 0, 15); |
| 246 | save_access_regs((unsigned int *) lc->access_regs_save_area); |
| 247 | memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list, |
| 248 | MAX_FACILITY_BIT/8); |
| 249 | } |
| 250 | |
| 251 | static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk) |
| 252 | { |
| 253 | struct _lowcore *lc = pcpu->lowcore; |
| 254 | struct thread_info *ti = task_thread_info(tsk); |
| 255 | |
| 256 | lc->kernel_stack = (unsigned long) task_stack_page(tsk) + THREAD_SIZE; |
| 257 | lc->thread_info = (unsigned long) task_thread_info(tsk); |
| 258 | lc->current_task = (unsigned long) tsk; |
| 259 | lc->user_timer = ti->user_timer; |
| 260 | lc->system_timer = ti->system_timer; |
| 261 | lc->steal_timer = 0; |
| 262 | } |
| 263 | |
| 264 | static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data) |
| 265 | { |
| 266 | struct _lowcore *lc = pcpu->lowcore; |
| 267 | |
| 268 | lc->restart_stack = lc->kernel_stack; |
| 269 | lc->restart_fn = (unsigned long) func; |
| 270 | lc->restart_data = (unsigned long) data; |
| 271 | lc->restart_source = -1UL; |
| 272 | pcpu_sigp_retry(pcpu, SIGP_RESTART, 0); |
| 273 | } |
| 274 | |
| 275 | /* |
| 276 | * Call function via PSW restart on pcpu and stop the current cpu. |
| 277 | */ |
| 278 | static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *), |
| 279 | void *data, unsigned long stack) |
| 280 | { |
| 281 | struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices]; |
| 282 | unsigned long source_cpu = stap(); |
| 283 | |
| 284 | __load_psw_mask(psw_kernel_bits); |
| 285 | if (pcpu->address == source_cpu) |
| 286 | func(data); /* should not return */ |
| 287 | /* Stop target cpu (if func returns this stops the current cpu). */ |
| 288 | pcpu_sigp_retry(pcpu, SIGP_STOP, 0); |
| 289 | /* Restart func on the target cpu and stop the current cpu. */ |
| 290 | mem_assign_absolute(lc->restart_stack, stack); |
| 291 | mem_assign_absolute(lc->restart_fn, (unsigned long) func); |
| 292 | mem_assign_absolute(lc->restart_data, (unsigned long) data); |
| 293 | mem_assign_absolute(lc->restart_source, source_cpu); |
| 294 | asm volatile( |
| 295 | "0: sigp 0,%0,%2 # sigp restart to target cpu\n" |
| 296 | " brc 2,0b # busy, try again\n" |
| 297 | "1: sigp 0,%1,%3 # sigp stop to current cpu\n" |
| 298 | " brc 2,1b # busy, try again\n" |
| 299 | : : "d" (pcpu->address), "d" (source_cpu), |
| 300 | "K" (SIGP_RESTART), "K" (SIGP_STOP) |
| 301 | : "0", "1", "cc"); |
| 302 | for (;;) ; |
| 303 | } |
| 304 | |
| 305 | /* |
| 306 | * Call function on an online CPU. |
| 307 | */ |
| 308 | void smp_call_online_cpu(void (*func)(void *), void *data) |
| 309 | { |
| 310 | struct pcpu *pcpu; |
| 311 | |
| 312 | /* Use the current cpu if it is online. */ |
| 313 | pcpu = pcpu_find_address(cpu_online_mask, stap()); |
| 314 | if (!pcpu) |
| 315 | /* Use the first online cpu. */ |
| 316 | pcpu = pcpu_devices + cpumask_first(cpu_online_mask); |
| 317 | pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack); |
| 318 | } |
| 319 | |
| 320 | /* |
| 321 | * Call function on the ipl CPU. |
| 322 | */ |
| 323 | void smp_call_ipl_cpu(void (*func)(void *), void *data) |
| 324 | { |
| 325 | pcpu_delegate(&pcpu_devices[0], func, data, |
| 326 | pcpu_devices->panic_stack + PAGE_SIZE); |
| 327 | } |
| 328 | |
| 329 | int smp_find_processor_id(u16 address) |
| 330 | { |
| 331 | int cpu; |
| 332 | |
| 333 | for_each_present_cpu(cpu) |
| 334 | if (pcpu_devices[cpu].address == address) |
| 335 | return cpu; |
| 336 | return -1; |
| 337 | } |
| 338 | |
| 339 | int smp_vcpu_scheduled(int cpu) |
| 340 | { |
| 341 | return pcpu_running(pcpu_devices + cpu); |
| 342 | } |
| 343 | |
| 344 | void smp_yield(void) |
| 345 | { |
| 346 | if (MACHINE_HAS_DIAG44) |
| 347 | asm volatile("diag 0,0,0x44"); |
| 348 | } |
| 349 | |
| 350 | void smp_yield_cpu(int cpu) |
| 351 | { |
| 352 | if (MACHINE_HAS_DIAG9C) |
| 353 | asm volatile("diag %0,0,0x9c" |
| 354 | : : "d" (pcpu_devices[cpu].address)); |
| 355 | else if (MACHINE_HAS_DIAG44) |
| 356 | asm volatile("diag 0,0,0x44"); |
| 357 | } |
| 358 | |
| 359 | /* |
| 360 | * Send cpus emergency shutdown signal. This gives the cpus the |
| 361 | * opportunity to complete outstanding interrupts. |
| 362 | */ |
| 363 | void smp_emergency_stop(cpumask_t *cpumask) |
| 364 | { |
| 365 | u64 end; |
| 366 | int cpu; |
| 367 | |
| 368 | end = get_tod_clock() + (1000000UL << 12); |
| 369 | for_each_cpu(cpu, cpumask) { |
| 370 | struct pcpu *pcpu = pcpu_devices + cpu; |
| 371 | set_bit(ec_stop_cpu, &pcpu->ec_mask); |
| 372 | while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL, |
| 373 | 0, NULL) == SIGP_CC_BUSY && |
| 374 | get_tod_clock() < end) |
| 375 | cpu_relax(); |
| 376 | } |
| 377 | while (get_tod_clock() < end) { |
| 378 | for_each_cpu(cpu, cpumask) |
| 379 | if (pcpu_stopped(pcpu_devices + cpu)) |
| 380 | cpumask_clear_cpu(cpu, cpumask); |
| 381 | if (cpumask_empty(cpumask)) |
| 382 | break; |
| 383 | cpu_relax(); |
| 384 | } |
| 385 | } |
| 386 | |
| 387 | /* |
| 388 | * Stop all cpus but the current one. |
| 389 | */ |
| 390 | void smp_send_stop(void) |
| 391 | { |
| 392 | cpumask_t cpumask; |
| 393 | int cpu; |
| 394 | |
| 395 | /* Disable all interrupts/machine checks */ |
| 396 | __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT); |
| 397 | trace_hardirqs_off(); |
| 398 | |
| 399 | debug_set_critical(); |
| 400 | cpumask_copy(&cpumask, cpu_online_mask); |
| 401 | cpumask_clear_cpu(smp_processor_id(), &cpumask); |
| 402 | |
| 403 | if (oops_in_progress) |
| 404 | smp_emergency_stop(&cpumask); |
| 405 | |
| 406 | /* stop all processors */ |
| 407 | for_each_cpu(cpu, &cpumask) { |
| 408 | struct pcpu *pcpu = pcpu_devices + cpu; |
| 409 | pcpu_sigp_retry(pcpu, SIGP_STOP, 0); |
| 410 | while (!pcpu_stopped(pcpu)) |
| 411 | cpu_relax(); |
| 412 | } |
| 413 | } |
| 414 | |
| 415 | /* |
| 416 | * Stop the current cpu. |
| 417 | */ |
| 418 | void smp_stop_cpu(void) |
| 419 | { |
| 420 | pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0); |
| 421 | for (;;) ; |
| 422 | } |
| 423 | |
| 424 | /* |
| 425 | * This is the main routine where commands issued by other |
| 426 | * cpus are handled. |
| 427 | */ |
| 428 | static void do_ext_call_interrupt(struct ext_code ext_code, |
| 429 | unsigned int param32, unsigned long param64) |
| 430 | { |
| 431 | unsigned long bits; |
| 432 | int cpu; |
| 433 | |
| 434 | cpu = smp_processor_id(); |
| 435 | if (ext_code.code == 0x1202) |
| 436 | inc_irq_stat(IRQEXT_EXC); |
| 437 | else |
| 438 | inc_irq_stat(IRQEXT_EMS); |
| 439 | /* |
| 440 | * handle bit signal external calls |
| 441 | */ |
| 442 | bits = xchg(&pcpu_devices[cpu].ec_mask, 0); |
| 443 | |
| 444 | if (test_bit(ec_stop_cpu, &bits)) |
| 445 | smp_stop_cpu(); |
| 446 | |
| 447 | if (test_bit(ec_schedule, &bits)) |
| 448 | scheduler_ipi(); |
| 449 | |
| 450 | if (test_bit(ec_call_function, &bits)) |
| 451 | generic_smp_call_function_interrupt(); |
| 452 | |
| 453 | if (test_bit(ec_call_function_single, &bits)) |
| 454 | generic_smp_call_function_single_interrupt(); |
| 455 | |
| 456 | } |
| 457 | |
| 458 | void arch_send_call_function_ipi_mask(const struct cpumask *mask) |
| 459 | { |
| 460 | int cpu; |
| 461 | |
| 462 | for_each_cpu(cpu, mask) |
| 463 | pcpu_ec_call(pcpu_devices + cpu, ec_call_function); |
| 464 | } |
| 465 | |
| 466 | void arch_send_call_function_single_ipi(int cpu) |
| 467 | { |
| 468 | pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); |
| 469 | } |
| 470 | |
| 471 | #ifndef CONFIG_64BIT |
| 472 | /* |
| 473 | * this function sends a 'purge tlb' signal to another CPU. |
| 474 | */ |
| 475 | static void smp_ptlb_callback(void *info) |
| 476 | { |
| 477 | __tlb_flush_local(); |
| 478 | } |
| 479 | |
| 480 | void smp_ptlb_all(void) |
| 481 | { |
| 482 | on_each_cpu(smp_ptlb_callback, NULL, 1); |
| 483 | } |
| 484 | EXPORT_SYMBOL(smp_ptlb_all); |
| 485 | #endif /* ! CONFIG_64BIT */ |
| 486 | |
| 487 | /* |
| 488 | * this function sends a 'reschedule' IPI to another CPU. |
| 489 | * it goes straight through and wastes no time serializing |
| 490 | * anything. Worst case is that we lose a reschedule ... |
| 491 | */ |
| 492 | void smp_send_reschedule(int cpu) |
| 493 | { |
| 494 | pcpu_ec_call(pcpu_devices + cpu, ec_schedule); |
| 495 | } |
| 496 | |
| 497 | /* |
| 498 | * parameter area for the set/clear control bit callbacks |
| 499 | */ |
| 500 | struct ec_creg_mask_parms { |
| 501 | unsigned long orval; |
| 502 | unsigned long andval; |
| 503 | int cr; |
| 504 | }; |
| 505 | |
| 506 | /* |
| 507 | * callback for setting/clearing control bits |
| 508 | */ |
| 509 | static void smp_ctl_bit_callback(void *info) |
| 510 | { |
| 511 | struct ec_creg_mask_parms *pp = info; |
| 512 | unsigned long cregs[16]; |
| 513 | |
| 514 | __ctl_store(cregs, 0, 15); |
| 515 | cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval; |
| 516 | __ctl_load(cregs, 0, 15); |
| 517 | } |
| 518 | |
| 519 | /* |
| 520 | * Set a bit in a control register of all cpus |
| 521 | */ |
| 522 | void smp_ctl_set_bit(int cr, int bit) |
| 523 | { |
| 524 | struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr }; |
| 525 | |
| 526 | on_each_cpu(smp_ctl_bit_callback, &parms, 1); |
| 527 | } |
| 528 | EXPORT_SYMBOL(smp_ctl_set_bit); |
| 529 | |
| 530 | /* |
| 531 | * Clear a bit in a control register of all cpus |
| 532 | */ |
| 533 | void smp_ctl_clear_bit(int cr, int bit) |
| 534 | { |
| 535 | struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr }; |
| 536 | |
| 537 | on_each_cpu(smp_ctl_bit_callback, &parms, 1); |
| 538 | } |
| 539 | EXPORT_SYMBOL(smp_ctl_clear_bit); |
| 540 | |
| 541 | #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_CRASH_DUMP) |
| 542 | |
| 543 | struct save_area *zfcpdump_save_areas[NR_CPUS + 1]; |
| 544 | EXPORT_SYMBOL_GPL(zfcpdump_save_areas); |
| 545 | |
| 546 | static void __init smp_get_save_area(int cpu, u16 address) |
| 547 | { |
| 548 | void *lc = pcpu_devices[0].lowcore; |
| 549 | struct save_area *save_area; |
| 550 | |
| 551 | if (is_kdump_kernel()) |
| 552 | return; |
| 553 | if (!OLDMEM_BASE && (address == boot_cpu_address || |
| 554 | ipl_info.type != IPL_TYPE_FCP_DUMP)) |
| 555 | return; |
| 556 | if (cpu >= NR_CPUS) { |
| 557 | pr_warning("CPU %i exceeds the maximum %i and is excluded " |
| 558 | "from the dump\n", cpu, NR_CPUS - 1); |
| 559 | return; |
| 560 | } |
| 561 | save_area = kmalloc(sizeof(struct save_area), GFP_KERNEL); |
| 562 | if (!save_area) |
| 563 | panic("could not allocate memory for save area\n"); |
| 564 | zfcpdump_save_areas[cpu] = save_area; |
| 565 | #ifdef CONFIG_CRASH_DUMP |
| 566 | if (address == boot_cpu_address) { |
| 567 | /* Copy the registers of the boot cpu. */ |
| 568 | copy_oldmem_page(1, (void *) save_area, sizeof(*save_area), |
| 569 | SAVE_AREA_BASE - PAGE_SIZE, 0); |
| 570 | return; |
| 571 | } |
| 572 | #endif |
| 573 | /* Get the registers of a non-boot cpu. */ |
| 574 | __pcpu_sigp_relax(address, SIGP_STOP_AND_STORE_STATUS, 0, NULL); |
| 575 | memcpy_real(save_area, lc + SAVE_AREA_BASE, sizeof(*save_area)); |
| 576 | } |
| 577 | |
| 578 | int smp_store_status(int cpu) |
| 579 | { |
| 580 | struct pcpu *pcpu; |
| 581 | |
| 582 | pcpu = pcpu_devices + cpu; |
| 583 | if (__pcpu_sigp_relax(pcpu->address, SIGP_STOP_AND_STORE_STATUS, |
| 584 | 0, NULL) != SIGP_CC_ORDER_CODE_ACCEPTED) |
| 585 | return -EIO; |
| 586 | return 0; |
| 587 | } |
| 588 | |
| 589 | #else /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */ |
| 590 | |
| 591 | static inline void smp_get_save_area(int cpu, u16 address) { } |
| 592 | |
| 593 | #endif /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */ |
| 594 | |
| 595 | void smp_cpu_set_polarization(int cpu, int val) |
| 596 | { |
| 597 | pcpu_devices[cpu].polarization = val; |
| 598 | } |
| 599 | |
| 600 | int smp_cpu_get_polarization(int cpu) |
| 601 | { |
| 602 | return pcpu_devices[cpu].polarization; |
| 603 | } |
| 604 | |
| 605 | static struct sclp_cpu_info *smp_get_cpu_info(void) |
| 606 | { |
| 607 | static int use_sigp_detection; |
| 608 | struct sclp_cpu_info *info; |
| 609 | int address; |
| 610 | |
| 611 | info = kzalloc(sizeof(*info), GFP_KERNEL); |
| 612 | if (info && (use_sigp_detection || sclp_get_cpu_info(info))) { |
| 613 | use_sigp_detection = 1; |
| 614 | for (address = 0; address <= MAX_CPU_ADDRESS; address++) { |
| 615 | if (__pcpu_sigp_relax(address, SIGP_SENSE, 0, NULL) == |
| 616 | SIGP_CC_NOT_OPERATIONAL) |
| 617 | continue; |
| 618 | info->cpu[info->configured].address = address; |
| 619 | info->configured++; |
| 620 | } |
| 621 | info->combined = info->configured; |
| 622 | } |
| 623 | return info; |
| 624 | } |
| 625 | |
| 626 | static int __cpuinit smp_add_present_cpu(int cpu); |
| 627 | |
| 628 | static int __cpuinit __smp_rescan_cpus(struct sclp_cpu_info *info, |
| 629 | int sysfs_add) |
| 630 | { |
| 631 | struct pcpu *pcpu; |
| 632 | cpumask_t avail; |
| 633 | int cpu, nr, i; |
| 634 | |
| 635 | nr = 0; |
| 636 | cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask); |
| 637 | cpu = cpumask_first(&avail); |
| 638 | for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) { |
| 639 | if (info->has_cpu_type && info->cpu[i].type != boot_cpu_type) |
| 640 | continue; |
| 641 | if (pcpu_find_address(cpu_present_mask, info->cpu[i].address)) |
| 642 | continue; |
| 643 | pcpu = pcpu_devices + cpu; |
| 644 | pcpu->address = info->cpu[i].address; |
| 645 | pcpu->state = (cpu >= info->configured) ? |
| 646 | CPU_STATE_STANDBY : CPU_STATE_CONFIGURED; |
| 647 | smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); |
| 648 | set_cpu_present(cpu, true); |
| 649 | if (sysfs_add && smp_add_present_cpu(cpu) != 0) |
| 650 | set_cpu_present(cpu, false); |
| 651 | else |
| 652 | nr++; |
| 653 | cpu = cpumask_next(cpu, &avail); |
| 654 | } |
| 655 | return nr; |
| 656 | } |
| 657 | |
| 658 | static void __init smp_detect_cpus(void) |
| 659 | { |
| 660 | unsigned int cpu, c_cpus, s_cpus; |
| 661 | struct sclp_cpu_info *info; |
| 662 | |
| 663 | info = smp_get_cpu_info(); |
| 664 | if (!info) |
| 665 | panic("smp_detect_cpus failed to allocate memory\n"); |
| 666 | if (info->has_cpu_type) { |
| 667 | for (cpu = 0; cpu < info->combined; cpu++) { |
| 668 | if (info->cpu[cpu].address != boot_cpu_address) |
| 669 | continue; |
| 670 | /* The boot cpu dictates the cpu type. */ |
| 671 | boot_cpu_type = info->cpu[cpu].type; |
| 672 | break; |
| 673 | } |
| 674 | } |
| 675 | c_cpus = s_cpus = 0; |
| 676 | for (cpu = 0; cpu < info->combined; cpu++) { |
| 677 | if (info->has_cpu_type && info->cpu[cpu].type != boot_cpu_type) |
| 678 | continue; |
| 679 | if (cpu < info->configured) { |
| 680 | smp_get_save_area(c_cpus, info->cpu[cpu].address); |
| 681 | c_cpus++; |
| 682 | } else |
| 683 | s_cpus++; |
| 684 | } |
| 685 | pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus); |
| 686 | get_online_cpus(); |
| 687 | __smp_rescan_cpus(info, 0); |
| 688 | put_online_cpus(); |
| 689 | kfree(info); |
| 690 | } |
| 691 | |
| 692 | /* |
| 693 | * Activate a secondary processor. |
| 694 | */ |
| 695 | static void __cpuinit smp_start_secondary(void *cpuvoid) |
| 696 | { |
| 697 | S390_lowcore.last_update_clock = get_tod_clock(); |
| 698 | S390_lowcore.restart_stack = (unsigned long) restart_stack; |
| 699 | S390_lowcore.restart_fn = (unsigned long) do_restart; |
| 700 | S390_lowcore.restart_data = 0; |
| 701 | S390_lowcore.restart_source = -1UL; |
| 702 | restore_access_regs(S390_lowcore.access_regs_save_area); |
| 703 | __ctl_load(S390_lowcore.cregs_save_area, 0, 15); |
| 704 | __load_psw_mask(psw_kernel_bits | PSW_MASK_DAT); |
| 705 | cpu_init(); |
| 706 | preempt_disable(); |
| 707 | init_cpu_timer(); |
| 708 | init_cpu_vtimer(); |
| 709 | pfault_init(); |
| 710 | notify_cpu_starting(smp_processor_id()); |
| 711 | set_cpu_online(smp_processor_id(), true); |
| 712 | inc_irq_stat(CPU_RST); |
| 713 | local_irq_enable(); |
| 714 | cpu_startup_entry(CPUHP_ONLINE); |
| 715 | } |
| 716 | |
| 717 | /* Upping and downing of CPUs */ |
| 718 | int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle) |
| 719 | { |
| 720 | struct pcpu *pcpu; |
| 721 | int rc; |
| 722 | |
| 723 | pcpu = pcpu_devices + cpu; |
| 724 | if (pcpu->state != CPU_STATE_CONFIGURED) |
| 725 | return -EIO; |
| 726 | if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) != |
| 727 | SIGP_CC_ORDER_CODE_ACCEPTED) |
| 728 | return -EIO; |
| 729 | |
| 730 | rc = pcpu_alloc_lowcore(pcpu, cpu); |
| 731 | if (rc) |
| 732 | return rc; |
| 733 | pcpu_prepare_secondary(pcpu, cpu); |
| 734 | pcpu_attach_task(pcpu, tidle); |
| 735 | pcpu_start_fn(pcpu, smp_start_secondary, NULL); |
| 736 | while (!cpu_online(cpu)) |
| 737 | cpu_relax(); |
| 738 | return 0; |
| 739 | } |
| 740 | |
| 741 | static int __init setup_possible_cpus(char *s) |
| 742 | { |
| 743 | int max, cpu; |
| 744 | |
| 745 | if (kstrtoint(s, 0, &max) < 0) |
| 746 | return 0; |
| 747 | init_cpu_possible(cpumask_of(0)); |
| 748 | for (cpu = 1; cpu < max && cpu < nr_cpu_ids; cpu++) |
| 749 | set_cpu_possible(cpu, true); |
| 750 | return 0; |
| 751 | } |
| 752 | early_param("possible_cpus", setup_possible_cpus); |
| 753 | |
| 754 | #ifdef CONFIG_HOTPLUG_CPU |
| 755 | |
| 756 | int __cpu_disable(void) |
| 757 | { |
| 758 | unsigned long cregs[16]; |
| 759 | |
| 760 | set_cpu_online(smp_processor_id(), false); |
| 761 | /* Disable pseudo page faults on this cpu. */ |
| 762 | pfault_fini(); |
| 763 | /* Disable interrupt sources via control register. */ |
| 764 | __ctl_store(cregs, 0, 15); |
| 765 | cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */ |
| 766 | cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */ |
| 767 | cregs[14] &= ~0x1f000000UL; /* disable most machine checks */ |
| 768 | __ctl_load(cregs, 0, 15); |
| 769 | return 0; |
| 770 | } |
| 771 | |
| 772 | void __cpu_die(unsigned int cpu) |
| 773 | { |
| 774 | struct pcpu *pcpu; |
| 775 | |
| 776 | /* Wait until target cpu is down */ |
| 777 | pcpu = pcpu_devices + cpu; |
| 778 | while (!pcpu_stopped(pcpu)) |
| 779 | cpu_relax(); |
| 780 | pcpu_free_lowcore(pcpu); |
| 781 | atomic_dec(&init_mm.context.attach_count); |
| 782 | } |
| 783 | |
| 784 | void __noreturn cpu_die(void) |
| 785 | { |
| 786 | idle_task_exit(); |
| 787 | pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0); |
| 788 | for (;;) ; |
| 789 | } |
| 790 | |
| 791 | #endif /* CONFIG_HOTPLUG_CPU */ |
| 792 | |
| 793 | void __init smp_prepare_cpus(unsigned int max_cpus) |
| 794 | { |
| 795 | /* request the 0x1201 emergency signal external interrupt */ |
| 796 | if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0) |
| 797 | panic("Couldn't request external interrupt 0x1201"); |
| 798 | /* request the 0x1202 external call external interrupt */ |
| 799 | if (register_external_interrupt(0x1202, do_ext_call_interrupt) != 0) |
| 800 | panic("Couldn't request external interrupt 0x1202"); |
| 801 | smp_detect_cpus(); |
| 802 | } |
| 803 | |
| 804 | void __init smp_prepare_boot_cpu(void) |
| 805 | { |
| 806 | struct pcpu *pcpu = pcpu_devices; |
| 807 | |
| 808 | boot_cpu_address = stap(); |
| 809 | pcpu->state = CPU_STATE_CONFIGURED; |
| 810 | pcpu->address = boot_cpu_address; |
| 811 | pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix(); |
| 812 | pcpu->async_stack = S390_lowcore.async_stack - ASYNC_SIZE; |
| 813 | pcpu->panic_stack = S390_lowcore.panic_stack - PAGE_SIZE; |
| 814 | S390_lowcore.percpu_offset = __per_cpu_offset[0]; |
| 815 | smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN); |
| 816 | set_cpu_present(0, true); |
| 817 | set_cpu_online(0, true); |
| 818 | } |
| 819 | |
| 820 | void __init smp_cpus_done(unsigned int max_cpus) |
| 821 | { |
| 822 | } |
| 823 | |
| 824 | void __init smp_setup_processor_id(void) |
| 825 | { |
| 826 | S390_lowcore.cpu_nr = 0; |
| 827 | } |
| 828 | |
| 829 | /* |
| 830 | * the frequency of the profiling timer can be changed |
| 831 | * by writing a multiplier value into /proc/profile. |
| 832 | * |
| 833 | * usually you want to run this on all CPUs ;) |
| 834 | */ |
| 835 | int setup_profiling_timer(unsigned int multiplier) |
| 836 | { |
| 837 | return 0; |
| 838 | } |
| 839 | |
| 840 | #ifdef CONFIG_HOTPLUG_CPU |
| 841 | static ssize_t cpu_configure_show(struct device *dev, |
| 842 | struct device_attribute *attr, char *buf) |
| 843 | { |
| 844 | ssize_t count; |
| 845 | |
| 846 | mutex_lock(&smp_cpu_state_mutex); |
| 847 | count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state); |
| 848 | mutex_unlock(&smp_cpu_state_mutex); |
| 849 | return count; |
| 850 | } |
| 851 | |
| 852 | static ssize_t cpu_configure_store(struct device *dev, |
| 853 | struct device_attribute *attr, |
| 854 | const char *buf, size_t count) |
| 855 | { |
| 856 | struct pcpu *pcpu; |
| 857 | int cpu, val, rc; |
| 858 | char delim; |
| 859 | |
| 860 | if (sscanf(buf, "%d %c", &val, &delim) != 1) |
| 861 | return -EINVAL; |
| 862 | if (val != 0 && val != 1) |
| 863 | return -EINVAL; |
| 864 | get_online_cpus(); |
| 865 | mutex_lock(&smp_cpu_state_mutex); |
| 866 | rc = -EBUSY; |
| 867 | /* disallow configuration changes of online cpus and cpu 0 */ |
| 868 | cpu = dev->id; |
| 869 | if (cpu_online(cpu) || cpu == 0) |
| 870 | goto out; |
| 871 | pcpu = pcpu_devices + cpu; |
| 872 | rc = 0; |
| 873 | switch (val) { |
| 874 | case 0: |
| 875 | if (pcpu->state != CPU_STATE_CONFIGURED) |
| 876 | break; |
| 877 | rc = sclp_cpu_deconfigure(pcpu->address); |
| 878 | if (rc) |
| 879 | break; |
| 880 | pcpu->state = CPU_STATE_STANDBY; |
| 881 | smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); |
| 882 | topology_expect_change(); |
| 883 | break; |
| 884 | case 1: |
| 885 | if (pcpu->state != CPU_STATE_STANDBY) |
| 886 | break; |
| 887 | rc = sclp_cpu_configure(pcpu->address); |
| 888 | if (rc) |
| 889 | break; |
| 890 | pcpu->state = CPU_STATE_CONFIGURED; |
| 891 | smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); |
| 892 | topology_expect_change(); |
| 893 | break; |
| 894 | default: |
| 895 | break; |
| 896 | } |
| 897 | out: |
| 898 | mutex_unlock(&smp_cpu_state_mutex); |
| 899 | put_online_cpus(); |
| 900 | return rc ? rc : count; |
| 901 | } |
| 902 | static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store); |
| 903 | #endif /* CONFIG_HOTPLUG_CPU */ |
| 904 | |
| 905 | static ssize_t show_cpu_address(struct device *dev, |
| 906 | struct device_attribute *attr, char *buf) |
| 907 | { |
| 908 | return sprintf(buf, "%d\n", pcpu_devices[dev->id].address); |
| 909 | } |
| 910 | static DEVICE_ATTR(address, 0444, show_cpu_address, NULL); |
| 911 | |
| 912 | static struct attribute *cpu_common_attrs[] = { |
| 913 | #ifdef CONFIG_HOTPLUG_CPU |
| 914 | &dev_attr_configure.attr, |
| 915 | #endif |
| 916 | &dev_attr_address.attr, |
| 917 | NULL, |
| 918 | }; |
| 919 | |
| 920 | static struct attribute_group cpu_common_attr_group = { |
| 921 | .attrs = cpu_common_attrs, |
| 922 | }; |
| 923 | |
| 924 | static ssize_t show_idle_count(struct device *dev, |
| 925 | struct device_attribute *attr, char *buf) |
| 926 | { |
| 927 | struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id); |
| 928 | unsigned long long idle_count; |
| 929 | unsigned int sequence; |
| 930 | |
| 931 | do { |
| 932 | sequence = ACCESS_ONCE(idle->sequence); |
| 933 | idle_count = ACCESS_ONCE(idle->idle_count); |
| 934 | if (ACCESS_ONCE(idle->clock_idle_enter)) |
| 935 | idle_count++; |
| 936 | } while ((sequence & 1) || (idle->sequence != sequence)); |
| 937 | return sprintf(buf, "%llu\n", idle_count); |
| 938 | } |
| 939 | static DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL); |
| 940 | |
| 941 | static ssize_t show_idle_time(struct device *dev, |
| 942 | struct device_attribute *attr, char *buf) |
| 943 | { |
| 944 | struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id); |
| 945 | unsigned long long now, idle_time, idle_enter, idle_exit; |
| 946 | unsigned int sequence; |
| 947 | |
| 948 | do { |
| 949 | now = get_tod_clock(); |
| 950 | sequence = ACCESS_ONCE(idle->sequence); |
| 951 | idle_time = ACCESS_ONCE(idle->idle_time); |
| 952 | idle_enter = ACCESS_ONCE(idle->clock_idle_enter); |
| 953 | idle_exit = ACCESS_ONCE(idle->clock_idle_exit); |
| 954 | } while ((sequence & 1) || (idle->sequence != sequence)); |
| 955 | idle_time += idle_enter ? ((idle_exit ? : now) - idle_enter) : 0; |
| 956 | return sprintf(buf, "%llu\n", idle_time >> 12); |
| 957 | } |
| 958 | static DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL); |
| 959 | |
| 960 | static struct attribute *cpu_online_attrs[] = { |
| 961 | &dev_attr_idle_count.attr, |
| 962 | &dev_attr_idle_time_us.attr, |
| 963 | NULL, |
| 964 | }; |
| 965 | |
| 966 | static struct attribute_group cpu_online_attr_group = { |
| 967 | .attrs = cpu_online_attrs, |
| 968 | }; |
| 969 | |
| 970 | static int __cpuinit smp_cpu_notify(struct notifier_block *self, |
| 971 | unsigned long action, void *hcpu) |
| 972 | { |
| 973 | unsigned int cpu = (unsigned int)(long)hcpu; |
| 974 | struct cpu *c = &pcpu_devices[cpu].cpu; |
| 975 | struct device *s = &c->dev; |
| 976 | int err = 0; |
| 977 | |
| 978 | switch (action & ~CPU_TASKS_FROZEN) { |
| 979 | case CPU_ONLINE: |
| 980 | err = sysfs_create_group(&s->kobj, &cpu_online_attr_group); |
| 981 | break; |
| 982 | case CPU_DEAD: |
| 983 | sysfs_remove_group(&s->kobj, &cpu_online_attr_group); |
| 984 | break; |
| 985 | } |
| 986 | return notifier_from_errno(err); |
| 987 | } |
| 988 | |
| 989 | static int __cpuinit smp_add_present_cpu(int cpu) |
| 990 | { |
| 991 | struct cpu *c = &pcpu_devices[cpu].cpu; |
| 992 | struct device *s = &c->dev; |
| 993 | int rc; |
| 994 | |
| 995 | c->hotpluggable = 1; |
| 996 | rc = register_cpu(c, cpu); |
| 997 | if (rc) |
| 998 | goto out; |
| 999 | rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group); |
| 1000 | if (rc) |
| 1001 | goto out_cpu; |
| 1002 | if (cpu_online(cpu)) { |
| 1003 | rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group); |
| 1004 | if (rc) |
| 1005 | goto out_online; |
| 1006 | } |
| 1007 | rc = topology_cpu_init(c); |
| 1008 | if (rc) |
| 1009 | goto out_topology; |
| 1010 | return 0; |
| 1011 | |
| 1012 | out_topology: |
| 1013 | if (cpu_online(cpu)) |
| 1014 | sysfs_remove_group(&s->kobj, &cpu_online_attr_group); |
| 1015 | out_online: |
| 1016 | sysfs_remove_group(&s->kobj, &cpu_common_attr_group); |
| 1017 | out_cpu: |
| 1018 | #ifdef CONFIG_HOTPLUG_CPU |
| 1019 | unregister_cpu(c); |
| 1020 | #endif |
| 1021 | out: |
| 1022 | return rc; |
| 1023 | } |
| 1024 | |
| 1025 | #ifdef CONFIG_HOTPLUG_CPU |
| 1026 | |
| 1027 | int __ref smp_rescan_cpus(void) |
| 1028 | { |
| 1029 | struct sclp_cpu_info *info; |
| 1030 | int nr; |
| 1031 | |
| 1032 | info = smp_get_cpu_info(); |
| 1033 | if (!info) |
| 1034 | return -ENOMEM; |
| 1035 | get_online_cpus(); |
| 1036 | mutex_lock(&smp_cpu_state_mutex); |
| 1037 | nr = __smp_rescan_cpus(info, 1); |
| 1038 | mutex_unlock(&smp_cpu_state_mutex); |
| 1039 | put_online_cpus(); |
| 1040 | kfree(info); |
| 1041 | if (nr) |
| 1042 | topology_schedule_update(); |
| 1043 | return 0; |
| 1044 | } |
| 1045 | |
| 1046 | static ssize_t __ref rescan_store(struct device *dev, |
| 1047 | struct device_attribute *attr, |
| 1048 | const char *buf, |
| 1049 | size_t count) |
| 1050 | { |
| 1051 | int rc; |
| 1052 | |
| 1053 | rc = smp_rescan_cpus(); |
| 1054 | return rc ? rc : count; |
| 1055 | } |
| 1056 | static DEVICE_ATTR(rescan, 0200, NULL, rescan_store); |
| 1057 | #endif /* CONFIG_HOTPLUG_CPU */ |
| 1058 | |
| 1059 | static int __init s390_smp_init(void) |
| 1060 | { |
| 1061 | int cpu, rc; |
| 1062 | |
| 1063 | hotcpu_notifier(smp_cpu_notify, 0); |
| 1064 | #ifdef CONFIG_HOTPLUG_CPU |
| 1065 | rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan); |
| 1066 | if (rc) |
| 1067 | return rc; |
| 1068 | #endif |
| 1069 | for_each_present_cpu(cpu) { |
| 1070 | rc = smp_add_present_cpu(cpu); |
| 1071 | if (rc) |
| 1072 | return rc; |
| 1073 | } |
| 1074 | return 0; |
| 1075 | } |
| 1076 | subsys_initcall(s390_smp_init); |