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1/*
2 * arch/s390/kernel/smp.c
3 *
4 * Copyright IBM Corp. 1999, 2009
5 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
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 * We work with logical cpu numbering everywhere we can. The only
14 * functions using the real cpu address (got from STAP) are the sigp
15 * functions. For all other functions we use the identity mapping.
16 * That means that cpu_number_map[i] == i for every cpu. cpu_number_map is
17 * used e.g. to find the idle task belonging to a logical cpu. Every array
18 * in the kernel is sorted by the logical cpu number and not by the physical
19 * one which is causing all the confusion with __cpu_logical_map and
20 * cpu_number_map in other architectures.
21 */
22
23#define KMSG_COMPONENT "cpu"
24#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
25
26#include <linux/workqueue.h>
27#include <linux/module.h>
28#include <linux/init.h>
29#include <linux/mm.h>
30#include <linux/err.h>
31#include <linux/spinlock.h>
32#include <linux/kernel_stat.h>
33#include <linux/delay.h>
34#include <linux/cache.h>
35#include <linux/interrupt.h>
36#include <linux/irqflags.h>
37#include <linux/cpu.h>
38#include <linux/timex.h>
39#include <linux/bootmem.h>
40#include <linux/slab.h>
41#include <asm/asm-offsets.h>
42#include <asm/ipl.h>
43#include <asm/setup.h>
44#include <asm/sigp.h>
45#include <asm/pgalloc.h>
46#include <asm/irq.h>
47#include <asm/cpcmd.h>
48#include <asm/tlbflush.h>
49#include <asm/timer.h>
50#include <asm/lowcore.h>
51#include <asm/sclp.h>
52#include <asm/cputime.h>
53#include <asm/vdso.h>
54#include <asm/cpu.h>
55#include "entry.h"
56
57/* logical cpu to cpu address */
58unsigned short __cpu_logical_map[NR_CPUS];
59
60static struct task_struct *current_set[NR_CPUS];
61
62static u8 smp_cpu_type;
63static int smp_use_sigp_detection;
64
65enum s390_cpu_state {
66 CPU_STATE_STANDBY,
67 CPU_STATE_CONFIGURED,
68};
69
70DEFINE_MUTEX(smp_cpu_state_mutex);
71int smp_cpu_polarization[NR_CPUS];
72static int smp_cpu_state[NR_CPUS];
73static int cpu_management;
74
75static DEFINE_PER_CPU(struct cpu, cpu_devices);
76
77static void smp_ext_bitcall(int, int);
78
79static int raw_cpu_stopped(int cpu)
80{
81 u32 status;
82
83 switch (raw_sigp_ps(&status, 0, cpu, sigp_sense)) {
84 case sigp_status_stored:
85 /* Check for stopped and check stop state */
86 if (status & 0x50)
87 return 1;
88 break;
89 default:
90 break;
91 }
92 return 0;
93}
94
95static inline int cpu_stopped(int cpu)
96{
97 return raw_cpu_stopped(cpu_logical_map(cpu));
98}
99
100void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
101{
102 struct _lowcore *lc, *current_lc;
103 struct stack_frame *sf;
104 struct pt_regs *regs;
105 unsigned long sp;
106
107 if (smp_processor_id() == 0)
108 func(data);
109 __load_psw_mask(PSW_BASE_BITS | PSW_DEFAULT_KEY);
110 /* Disable lowcore protection */
111 __ctl_clear_bit(0, 28);
112 current_lc = lowcore_ptr[smp_processor_id()];
113 lc = lowcore_ptr[0];
114 if (!lc)
115 lc = current_lc;
116 lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
117 lc->restart_psw.addr = PSW_ADDR_AMODE | (unsigned long) smp_restart_cpu;
118 if (!cpu_online(0))
119 smp_switch_to_cpu(func, data, 0, stap(), __cpu_logical_map[0]);
120 while (sigp(0, sigp_stop_and_store_status) == sigp_busy)
121 cpu_relax();
122 sp = lc->panic_stack;
123 sp -= sizeof(struct pt_regs);
124 regs = (struct pt_regs *) sp;
125 memcpy(®s->gprs, ¤t_lc->gpregs_save_area, sizeof(regs->gprs));
126 regs->psw = lc->psw_save_area;
127 sp -= STACK_FRAME_OVERHEAD;
128 sf = (struct stack_frame *) sp;
129 sf->back_chain = regs->gprs[15];
130 smp_switch_to_cpu(func, data, sp, stap(), __cpu_logical_map[0]);
131}
132
133void smp_send_stop(void)
134{
135 int cpu, rc;
136
137 /* Disable all interrupts/machine checks */
138 __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);
139 trace_hardirqs_off();
140
141 /* stop all processors */
142 for_each_online_cpu(cpu) {
143 if (cpu == smp_processor_id())
144 continue;
145 do {
146 rc = sigp(cpu, sigp_stop);
147 } while (rc == sigp_busy);
148
149 while (!cpu_stopped(cpu))
150 cpu_relax();
151 }
152}
153
154/*
155 * This is the main routine where commands issued by other
156 * cpus are handled.
157 */
158
159static void do_ext_call_interrupt(unsigned int ext_int_code,
160 unsigned int param32, unsigned long param64)
161{
162 unsigned long bits;
163
164 kstat_cpu(smp_processor_id()).irqs[EXTINT_IPI]++;
165 /*
166 * handle bit signal external calls
167 */
168 bits = xchg(&S390_lowcore.ext_call_fast, 0);
169
170 if (test_bit(ec_schedule, &bits))
171 scheduler_ipi();
172
173 if (test_bit(ec_call_function, &bits))
174 generic_smp_call_function_interrupt();
175
176 if (test_bit(ec_call_function_single, &bits))
177 generic_smp_call_function_single_interrupt();
178}
179
180/*
181 * Send an external call sigp to another cpu and return without waiting
182 * for its completion.
183 */
184static void smp_ext_bitcall(int cpu, int sig)
185{
186 /*
187 * Set signaling bit in lowcore of target cpu and kick it
188 */
189 set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
190 while (sigp(cpu, sigp_emergency_signal) == sigp_busy)
191 udelay(10);
192}
193
194void arch_send_call_function_ipi_mask(const struct cpumask *mask)
195{
196 int cpu;
197
198 for_each_cpu(cpu, mask)
199 smp_ext_bitcall(cpu, ec_call_function);
200}
201
202void arch_send_call_function_single_ipi(int cpu)
203{
204 smp_ext_bitcall(cpu, ec_call_function_single);
205}
206
207#ifndef CONFIG_64BIT
208/*
209 * this function sends a 'purge tlb' signal to another CPU.
210 */
211static void smp_ptlb_callback(void *info)
212{
213 __tlb_flush_local();
214}
215
216void smp_ptlb_all(void)
217{
218 on_each_cpu(smp_ptlb_callback, NULL, 1);
219}
220EXPORT_SYMBOL(smp_ptlb_all);
221#endif /* ! CONFIG_64BIT */
222
223/*
224 * this function sends a 'reschedule' IPI to another CPU.
225 * it goes straight through and wastes no time serializing
226 * anything. Worst case is that we lose a reschedule ...
227 */
228void smp_send_reschedule(int cpu)
229{
230 smp_ext_bitcall(cpu, ec_schedule);
231}
232
233/*
234 * parameter area for the set/clear control bit callbacks
235 */
236struct ec_creg_mask_parms {
237 unsigned long orvals[16];
238 unsigned long andvals[16];
239};
240
241/*
242 * callback for setting/clearing control bits
243 */
244static void smp_ctl_bit_callback(void *info)
245{
246 struct ec_creg_mask_parms *pp = info;
247 unsigned long cregs[16];
248 int i;
249
250 __ctl_store(cregs, 0, 15);
251 for (i = 0; i <= 15; i++)
252 cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
253 __ctl_load(cregs, 0, 15);
254}
255
256/*
257 * Set a bit in a control register of all cpus
258 */
259void smp_ctl_set_bit(int cr, int bit)
260{
261 struct ec_creg_mask_parms parms;
262
263 memset(&parms.orvals, 0, sizeof(parms.orvals));
264 memset(&parms.andvals, 0xff, sizeof(parms.andvals));
265 parms.orvals[cr] = 1UL << bit;
266 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
267}
268EXPORT_SYMBOL(smp_ctl_set_bit);
269
270/*
271 * Clear a bit in a control register of all cpus
272 */
273void smp_ctl_clear_bit(int cr, int bit)
274{
275 struct ec_creg_mask_parms parms;
276
277 memset(&parms.orvals, 0, sizeof(parms.orvals));
278 memset(&parms.andvals, 0xff, sizeof(parms.andvals));
279 parms.andvals[cr] = ~(1UL << bit);
280 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
281}
282EXPORT_SYMBOL(smp_ctl_clear_bit);
283
284#ifdef CONFIG_ZFCPDUMP
285
286static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
287{
288 if (ipl_info.type != IPL_TYPE_FCP_DUMP)
289 return;
290 if (cpu >= NR_CPUS) {
291 pr_warning("CPU %i exceeds the maximum %i and is excluded from "
292 "the dump\n", cpu, NR_CPUS - 1);
293 return;
294 }
295 zfcpdump_save_areas[cpu] = kmalloc(sizeof(struct save_area), GFP_KERNEL);
296 while (raw_sigp(phy_cpu, sigp_stop_and_store_status) == sigp_busy)
297 cpu_relax();
298 memcpy_real(zfcpdump_save_areas[cpu],
299 (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
300 sizeof(struct save_area));
301}
302
303struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
304EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
305
306#else
307
308static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
309
310#endif /* CONFIG_ZFCPDUMP */
311
312static int cpu_known(int cpu_id)
313{
314 int cpu;
315
316 for_each_present_cpu(cpu) {
317 if (__cpu_logical_map[cpu] == cpu_id)
318 return 1;
319 }
320 return 0;
321}
322
323static int smp_rescan_cpus_sigp(cpumask_t avail)
324{
325 int cpu_id, logical_cpu;
326
327 logical_cpu = cpumask_first(&avail);
328 if (logical_cpu >= nr_cpu_ids)
329 return 0;
330 for (cpu_id = 0; cpu_id <= MAX_CPU_ADDRESS; cpu_id++) {
331 if (cpu_known(cpu_id))
332 continue;
333 __cpu_logical_map[logical_cpu] = cpu_id;
334 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
335 if (!cpu_stopped(logical_cpu))
336 continue;
337 set_cpu_present(logical_cpu, true);
338 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
339 logical_cpu = cpumask_next(logical_cpu, &avail);
340 if (logical_cpu >= nr_cpu_ids)
341 break;
342 }
343 return 0;
344}
345
346static int smp_rescan_cpus_sclp(cpumask_t avail)
347{
348 struct sclp_cpu_info *info;
349 int cpu_id, logical_cpu, cpu;
350 int rc;
351
352 logical_cpu = cpumask_first(&avail);
353 if (logical_cpu >= nr_cpu_ids)
354 return 0;
355 info = kmalloc(sizeof(*info), GFP_KERNEL);
356 if (!info)
357 return -ENOMEM;
358 rc = sclp_get_cpu_info(info);
359 if (rc)
360 goto out;
361 for (cpu = 0; cpu < info->combined; cpu++) {
362 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
363 continue;
364 cpu_id = info->cpu[cpu].address;
365 if (cpu_known(cpu_id))
366 continue;
367 __cpu_logical_map[logical_cpu] = cpu_id;
368 smp_cpu_polarization[logical_cpu] = POLARIZATION_UNKNWN;
369 set_cpu_present(logical_cpu, true);
370 if (cpu >= info->configured)
371 smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
372 else
373 smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
374 logical_cpu = cpumask_next(logical_cpu, &avail);
375 if (logical_cpu >= nr_cpu_ids)
376 break;
377 }
378out:
379 kfree(info);
380 return rc;
381}
382
383static int __smp_rescan_cpus(void)
384{
385 cpumask_t avail;
386
387 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
388 if (smp_use_sigp_detection)
389 return smp_rescan_cpus_sigp(avail);
390 else
391 return smp_rescan_cpus_sclp(avail);
392}
393
394static void __init smp_detect_cpus(void)
395{
396 unsigned int cpu, c_cpus, s_cpus;
397 struct sclp_cpu_info *info;
398 u16 boot_cpu_addr, cpu_addr;
399
400 c_cpus = 1;
401 s_cpus = 0;
402 boot_cpu_addr = __cpu_logical_map[0];
403 info = kmalloc(sizeof(*info), GFP_KERNEL);
404 if (!info)
405 panic("smp_detect_cpus failed to allocate memory\n");
406 /* Use sigp detection algorithm if sclp doesn't work. */
407 if (sclp_get_cpu_info(info)) {
408 smp_use_sigp_detection = 1;
409 for (cpu = 0; cpu <= MAX_CPU_ADDRESS; cpu++) {
410 if (cpu == boot_cpu_addr)
411 continue;
412 if (!raw_cpu_stopped(cpu))
413 continue;
414 smp_get_save_area(c_cpus, cpu);
415 c_cpus++;
416 }
417 goto out;
418 }
419
420 if (info->has_cpu_type) {
421 for (cpu = 0; cpu < info->combined; cpu++) {
422 if (info->cpu[cpu].address == boot_cpu_addr) {
423 smp_cpu_type = info->cpu[cpu].type;
424 break;
425 }
426 }
427 }
428
429 for (cpu = 0; cpu < info->combined; cpu++) {
430 if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
431 continue;
432 cpu_addr = info->cpu[cpu].address;
433 if (cpu_addr == boot_cpu_addr)
434 continue;
435 if (!raw_cpu_stopped(cpu_addr)) {
436 s_cpus++;
437 continue;
438 }
439 smp_get_save_area(c_cpus, cpu_addr);
440 c_cpus++;
441 }
442out:
443 kfree(info);
444 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
445 get_online_cpus();
446 __smp_rescan_cpus();
447 put_online_cpus();
448}
449
450/*
451 * Activate a secondary processor.
452 */
453int __cpuinit start_secondary(void *cpuvoid)
454{
455 cpu_init();
456 preempt_disable();
457 init_cpu_timer();
458 init_cpu_vtimer();
459 pfault_init();
460
461 notify_cpu_starting(smp_processor_id());
462 ipi_call_lock();
463 set_cpu_online(smp_processor_id(), true);
464 ipi_call_unlock();
465 __ctl_clear_bit(0, 28); /* Disable lowcore protection */
466 S390_lowcore.restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
467 S390_lowcore.restart_psw.addr =
468 PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler;
469 __ctl_set_bit(0, 28); /* Enable lowcore protection */
470 /*
471 * Wait until the cpu which brought this one up marked it
472 * active before enabling interrupts.
473 */
474 while (!cpumask_test_cpu(smp_processor_id(), cpu_active_mask))
475 cpu_relax();
476 local_irq_enable();
477 /* cpu_idle will call schedule for us */
478 cpu_idle();
479 return 0;
480}
481
482struct create_idle {
483 struct work_struct work;
484 struct task_struct *idle;
485 struct completion done;
486 int cpu;
487};
488
489static void __cpuinit smp_fork_idle(struct work_struct *work)
490{
491 struct create_idle *c_idle;
492
493 c_idle = container_of(work, struct create_idle, work);
494 c_idle->idle = fork_idle(c_idle->cpu);
495 complete(&c_idle->done);
496}
497
498static int __cpuinit smp_alloc_lowcore(int cpu)
499{
500 unsigned long async_stack, panic_stack;
501 struct _lowcore *lowcore;
502
503 lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
504 if (!lowcore)
505 return -ENOMEM;
506 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
507 panic_stack = __get_free_page(GFP_KERNEL);
508 if (!panic_stack || !async_stack)
509 goto out;
510 memcpy(lowcore, &S390_lowcore, 512);
511 memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
512 lowcore->async_stack = async_stack + ASYNC_SIZE;
513 lowcore->panic_stack = panic_stack + PAGE_SIZE;
514 lowcore->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
515 lowcore->restart_psw.addr =
516 PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
517 if (user_mode != HOME_SPACE_MODE)
518 lowcore->restart_psw.mask |= PSW_ASC_HOME;
519#ifndef CONFIG_64BIT
520 if (MACHINE_HAS_IEEE) {
521 unsigned long save_area;
522
523 save_area = get_zeroed_page(GFP_KERNEL);
524 if (!save_area)
525 goto out;
526 lowcore->extended_save_area_addr = (u32) save_area;
527 }
528#else
529 if (vdso_alloc_per_cpu(cpu, lowcore))
530 goto out;
531#endif
532 lowcore_ptr[cpu] = lowcore;
533 return 0;
534
535out:
536 free_page(panic_stack);
537 free_pages(async_stack, ASYNC_ORDER);
538 free_pages((unsigned long) lowcore, LC_ORDER);
539 return -ENOMEM;
540}
541
542static void smp_free_lowcore(int cpu)
543{
544 struct _lowcore *lowcore;
545
546 lowcore = lowcore_ptr[cpu];
547#ifndef CONFIG_64BIT
548 if (MACHINE_HAS_IEEE)
549 free_page((unsigned long) lowcore->extended_save_area_addr);
550#else
551 vdso_free_per_cpu(cpu, lowcore);
552#endif
553 free_page(lowcore->panic_stack - PAGE_SIZE);
554 free_pages(lowcore->async_stack - ASYNC_SIZE, ASYNC_ORDER);
555 free_pages((unsigned long) lowcore, LC_ORDER);
556 lowcore_ptr[cpu] = NULL;
557}
558
559/* Upping and downing of CPUs */
560int __cpuinit __cpu_up(unsigned int cpu)
561{
562 struct _lowcore *cpu_lowcore;
563 struct create_idle c_idle;
564 struct task_struct *idle;
565 struct stack_frame *sf;
566 u32 lowcore;
567 int ccode;
568
569 if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
570 return -EIO;
571 idle = current_set[cpu];
572 if (!idle) {
573 c_idle.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done);
574 INIT_WORK_ONSTACK(&c_idle.work, smp_fork_idle);
575 c_idle.cpu = cpu;
576 schedule_work(&c_idle.work);
577 wait_for_completion(&c_idle.done);
578 if (IS_ERR(c_idle.idle))
579 return PTR_ERR(c_idle.idle);
580 idle = c_idle.idle;
581 current_set[cpu] = c_idle.idle;
582 }
583 init_idle(idle, cpu);
584 if (smp_alloc_lowcore(cpu))
585 return -ENOMEM;
586 do {
587 ccode = sigp(cpu, sigp_initial_cpu_reset);
588 if (ccode == sigp_busy)
589 udelay(10);
590 if (ccode == sigp_not_operational)
591 goto err_out;
592 } while (ccode == sigp_busy);
593
594 lowcore = (u32)(unsigned long)lowcore_ptr[cpu];
595 while (sigp_p(lowcore, cpu, sigp_set_prefix) == sigp_busy)
596 udelay(10);
597
598 cpu_lowcore = lowcore_ptr[cpu];
599 cpu_lowcore->kernel_stack = (unsigned long)
600 task_stack_page(idle) + THREAD_SIZE;
601 cpu_lowcore->thread_info = (unsigned long) task_thread_info(idle);
602 sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
603 - sizeof(struct pt_regs)
604 - sizeof(struct stack_frame));
605 memset(sf, 0, sizeof(struct stack_frame));
606 sf->gprs[9] = (unsigned long) sf;
607 cpu_lowcore->save_area[15] = (unsigned long) sf;
608 __ctl_store(cpu_lowcore->cregs_save_area, 0, 15);
609 atomic_inc(&init_mm.context.attach_count);
610 asm volatile(
611 " stam 0,15,0(%0)"
612 : : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
613 cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
614 cpu_lowcore->current_task = (unsigned long) idle;
615 cpu_lowcore->cpu_nr = cpu;
616 cpu_lowcore->kernel_asce = S390_lowcore.kernel_asce;
617 cpu_lowcore->machine_flags = S390_lowcore.machine_flags;
618 cpu_lowcore->ftrace_func = S390_lowcore.ftrace_func;
619 memcpy(cpu_lowcore->stfle_fac_list, S390_lowcore.stfle_fac_list,
620 MAX_FACILITY_BIT/8);
621 eieio();
622
623 while (sigp(cpu, sigp_restart) == sigp_busy)
624 udelay(10);
625
626 while (!cpu_online(cpu))
627 cpu_relax();
628 return 0;
629
630err_out:
631 smp_free_lowcore(cpu);
632 return -EIO;
633}
634
635static int __init setup_possible_cpus(char *s)
636{
637 int pcpus, cpu;
638
639 pcpus = simple_strtoul(s, NULL, 0);
640 init_cpu_possible(cpumask_of(0));
641 for (cpu = 1; cpu < pcpus && cpu < nr_cpu_ids; cpu++)
642 set_cpu_possible(cpu, true);
643 return 0;
644}
645early_param("possible_cpus", setup_possible_cpus);
646
647#ifdef CONFIG_HOTPLUG_CPU
648
649int __cpu_disable(void)
650{
651 struct ec_creg_mask_parms cr_parms;
652 int cpu = smp_processor_id();
653
654 set_cpu_online(cpu, false);
655
656 /* Disable pfault pseudo page faults on this cpu. */
657 pfault_fini();
658
659 memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals));
660 memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals));
661
662 /* disable all external interrupts */
663 cr_parms.orvals[0] = 0;
664 cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 11 |
665 1 << 10 | 1 << 9 | 1 << 6 | 1 << 5 |
666 1 << 4);
667 /* disable all I/O interrupts */
668 cr_parms.orvals[6] = 0;
669 cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
670 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
671 /* disable most machine checks */
672 cr_parms.orvals[14] = 0;
673 cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
674 1 << 25 | 1 << 24);
675
676 smp_ctl_bit_callback(&cr_parms);
677
678 return 0;
679}
680
681void __cpu_die(unsigned int cpu)
682{
683 /* Wait until target cpu is down */
684 while (!cpu_stopped(cpu))
685 cpu_relax();
686 while (sigp_p(0, cpu, sigp_set_prefix) == sigp_busy)
687 udelay(10);
688 smp_free_lowcore(cpu);
689 atomic_dec(&init_mm.context.attach_count);
690}
691
692void __noreturn cpu_die(void)
693{
694 idle_task_exit();
695 while (sigp(smp_processor_id(), sigp_stop) == sigp_busy)
696 cpu_relax();
697 for (;;);
698}
699
700#endif /* CONFIG_HOTPLUG_CPU */
701
702void __init smp_prepare_cpus(unsigned int max_cpus)
703{
704#ifndef CONFIG_64BIT
705 unsigned long save_area = 0;
706#endif
707 unsigned long async_stack, panic_stack;
708 struct _lowcore *lowcore;
709
710 smp_detect_cpus();
711
712 /* request the 0x1201 emergency signal external interrupt */
713 if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
714 panic("Couldn't request external interrupt 0x1201");
715
716 /* Reallocate current lowcore, but keep its contents. */
717 lowcore = (void *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
718 panic_stack = __get_free_page(GFP_KERNEL);
719 async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
720 BUG_ON(!lowcore || !panic_stack || !async_stack);
721#ifndef CONFIG_64BIT
722 if (MACHINE_HAS_IEEE)
723 save_area = get_zeroed_page(GFP_KERNEL);
724#endif
725 local_irq_disable();
726 local_mcck_disable();
727 lowcore_ptr[smp_processor_id()] = lowcore;
728 *lowcore = S390_lowcore;
729 lowcore->panic_stack = panic_stack + PAGE_SIZE;
730 lowcore->async_stack = async_stack + ASYNC_SIZE;
731#ifndef CONFIG_64BIT
732 if (MACHINE_HAS_IEEE)
733 lowcore->extended_save_area_addr = (u32) save_area;
734#endif
735 set_prefix((u32)(unsigned long) lowcore);
736 local_mcck_enable();
737 local_irq_enable();
738#ifdef CONFIG_64BIT
739 if (vdso_alloc_per_cpu(smp_processor_id(), &S390_lowcore))
740 BUG();
741#endif
742}
743
744void __init smp_prepare_boot_cpu(void)
745{
746 BUG_ON(smp_processor_id() != 0);
747
748 current_thread_info()->cpu = 0;
749 set_cpu_present(0, true);
750 set_cpu_online(0, true);
751 S390_lowcore.percpu_offset = __per_cpu_offset[0];
752 current_set[0] = current;
753 smp_cpu_state[0] = CPU_STATE_CONFIGURED;
754 smp_cpu_polarization[0] = POLARIZATION_UNKNWN;
755}
756
757void __init smp_cpus_done(unsigned int max_cpus)
758{
759}
760
761void __init smp_setup_processor_id(void)
762{
763 S390_lowcore.cpu_nr = 0;
764 __cpu_logical_map[0] = stap();
765}
766
767/*
768 * the frequency of the profiling timer can be changed
769 * by writing a multiplier value into /proc/profile.
770 *
771 * usually you want to run this on all CPUs ;)
772 */
773int setup_profiling_timer(unsigned int multiplier)
774{
775 return 0;
776}
777
778#ifdef CONFIG_HOTPLUG_CPU
779static ssize_t cpu_configure_show(struct sys_device *dev,
780 struct sysdev_attribute *attr, char *buf)
781{
782 ssize_t count;
783
784 mutex_lock(&smp_cpu_state_mutex);
785 count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
786 mutex_unlock(&smp_cpu_state_mutex);
787 return count;
788}
789
790static ssize_t cpu_configure_store(struct sys_device *dev,
791 struct sysdev_attribute *attr,
792 const char *buf, size_t count)
793{
794 int cpu = dev->id;
795 int val, rc;
796 char delim;
797
798 if (sscanf(buf, "%d %c", &val, &delim) != 1)
799 return -EINVAL;
800 if (val != 0 && val != 1)
801 return -EINVAL;
802
803 get_online_cpus();
804 mutex_lock(&smp_cpu_state_mutex);
805 rc = -EBUSY;
806 /* disallow configuration changes of online cpus and cpu 0 */
807 if (cpu_online(cpu) || cpu == 0)
808 goto out;
809 rc = 0;
810 switch (val) {
811 case 0:
812 if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
813 rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
814 if (!rc) {
815 smp_cpu_state[cpu] = CPU_STATE_STANDBY;
816 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
817 }
818 }
819 break;
820 case 1:
821 if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
822 rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
823 if (!rc) {
824 smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
825 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
826 }
827 }
828 break;
829 default:
830 break;
831 }
832out:
833 mutex_unlock(&smp_cpu_state_mutex);
834 put_online_cpus();
835 return rc ? rc : count;
836}
837static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
838#endif /* CONFIG_HOTPLUG_CPU */
839
840static ssize_t cpu_polarization_show(struct sys_device *dev,
841 struct sysdev_attribute *attr, char *buf)
842{
843 int cpu = dev->id;
844 ssize_t count;
845
846 mutex_lock(&smp_cpu_state_mutex);
847 switch (smp_cpu_polarization[cpu]) {
848 case POLARIZATION_HRZ:
849 count = sprintf(buf, "horizontal\n");
850 break;
851 case POLARIZATION_VL:
852 count = sprintf(buf, "vertical:low\n");
853 break;
854 case POLARIZATION_VM:
855 count = sprintf(buf, "vertical:medium\n");
856 break;
857 case POLARIZATION_VH:
858 count = sprintf(buf, "vertical:high\n");
859 break;
860 default:
861 count = sprintf(buf, "unknown\n");
862 break;
863 }
864 mutex_unlock(&smp_cpu_state_mutex);
865 return count;
866}
867static SYSDEV_ATTR(polarization, 0444, cpu_polarization_show, NULL);
868
869static ssize_t show_cpu_address(struct sys_device *dev,
870 struct sysdev_attribute *attr, char *buf)
871{
872 return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
873}
874static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
875
876
877static struct attribute *cpu_common_attrs[] = {
878#ifdef CONFIG_HOTPLUG_CPU
879 &attr_configure.attr,
880#endif
881 &attr_address.attr,
882 &attr_polarization.attr,
883 NULL,
884};
885
886static struct attribute_group cpu_common_attr_group = {
887 .attrs = cpu_common_attrs,
888};
889
890static ssize_t show_capability(struct sys_device *dev,
891 struct sysdev_attribute *attr, char *buf)
892{
893 unsigned int capability;
894 int rc;
895
896 rc = get_cpu_capability(&capability);
897 if (rc)
898 return rc;
899 return sprintf(buf, "%u\n", capability);
900}
901static SYSDEV_ATTR(capability, 0444, show_capability, NULL);
902
903static ssize_t show_idle_count(struct sys_device *dev,
904 struct sysdev_attribute *attr, char *buf)
905{
906 struct s390_idle_data *idle;
907 unsigned long long idle_count;
908 unsigned int sequence;
909
910 idle = &per_cpu(s390_idle, dev->id);
911repeat:
912 sequence = idle->sequence;
913 smp_rmb();
914 if (sequence & 1)
915 goto repeat;
916 idle_count = idle->idle_count;
917 if (idle->idle_enter)
918 idle_count++;
919 smp_rmb();
920 if (idle->sequence != sequence)
921 goto repeat;
922 return sprintf(buf, "%llu\n", idle_count);
923}
924static SYSDEV_ATTR(idle_count, 0444, show_idle_count, NULL);
925
926static ssize_t show_idle_time(struct sys_device *dev,
927 struct sysdev_attribute *attr, char *buf)
928{
929 struct s390_idle_data *idle;
930 unsigned long long now, idle_time, idle_enter;
931 unsigned int sequence;
932
933 idle = &per_cpu(s390_idle, dev->id);
934 now = get_clock();
935repeat:
936 sequence = idle->sequence;
937 smp_rmb();
938 if (sequence & 1)
939 goto repeat;
940 idle_time = idle->idle_time;
941 idle_enter = idle->idle_enter;
942 if (idle_enter != 0ULL && idle_enter < now)
943 idle_time += now - idle_enter;
944 smp_rmb();
945 if (idle->sequence != sequence)
946 goto repeat;
947 return sprintf(buf, "%llu\n", idle_time >> 12);
948}
949static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
950
951static struct attribute *cpu_online_attrs[] = {
952 &attr_capability.attr,
953 &attr_idle_count.attr,
954 &attr_idle_time_us.attr,
955 NULL,
956};
957
958static struct attribute_group cpu_online_attr_group = {
959 .attrs = cpu_online_attrs,
960};
961
962static int __cpuinit smp_cpu_notify(struct notifier_block *self,
963 unsigned long action, void *hcpu)
964{
965 unsigned int cpu = (unsigned int)(long)hcpu;
966 struct cpu *c = &per_cpu(cpu_devices, cpu);
967 struct sys_device *s = &c->sysdev;
968 struct s390_idle_data *idle;
969 int err = 0;
970
971 switch (action) {
972 case CPU_ONLINE:
973 case CPU_ONLINE_FROZEN:
974 idle = &per_cpu(s390_idle, cpu);
975 memset(idle, 0, sizeof(struct s390_idle_data));
976 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
977 break;
978 case CPU_DEAD:
979 case CPU_DEAD_FROZEN:
980 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
981 break;
982 }
983 return notifier_from_errno(err);
984}
985
986static struct notifier_block __cpuinitdata smp_cpu_nb = {
987 .notifier_call = smp_cpu_notify,
988};
989
990static int __devinit smp_add_present_cpu(int cpu)
991{
992 struct cpu *c = &per_cpu(cpu_devices, cpu);
993 struct sys_device *s = &c->sysdev;
994 int rc;
995
996 c->hotpluggable = 1;
997 rc = register_cpu(c, cpu);
998 if (rc)
999 goto out;
1000 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1001 if (rc)
1002 goto out_cpu;
1003 if (!cpu_online(cpu))
1004 goto out;
1005 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1006 if (!rc)
1007 return 0;
1008 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1009out_cpu:
1010#ifdef CONFIG_HOTPLUG_CPU
1011 unregister_cpu(c);
1012#endif
1013out:
1014 return rc;
1015}
1016
1017#ifdef CONFIG_HOTPLUG_CPU
1018
1019int __ref smp_rescan_cpus(void)
1020{
1021 cpumask_t newcpus;
1022 int cpu;
1023 int rc;
1024
1025 get_online_cpus();
1026 mutex_lock(&smp_cpu_state_mutex);
1027 cpumask_copy(&newcpus, cpu_present_mask);
1028 rc = __smp_rescan_cpus();
1029 if (rc)
1030 goto out;
1031 cpumask_andnot(&newcpus, cpu_present_mask, &newcpus);
1032 for_each_cpu(cpu, &newcpus) {
1033 rc = smp_add_present_cpu(cpu);
1034 if (rc)
1035 set_cpu_present(cpu, false);
1036 }
1037 rc = 0;
1038out:
1039 mutex_unlock(&smp_cpu_state_mutex);
1040 put_online_cpus();
1041 if (!cpumask_empty(&newcpus))
1042 topology_schedule_update();
1043 return rc;
1044}
1045
1046static ssize_t __ref rescan_store(struct sysdev_class *class,
1047 struct sysdev_class_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}
1056static SYSDEV_CLASS_ATTR(rescan, 0200, NULL, rescan_store);
1057#endif /* CONFIG_HOTPLUG_CPU */
1058
1059static ssize_t dispatching_show(struct sysdev_class *class,
1060 struct sysdev_class_attribute *attr,
1061 char *buf)
1062{
1063 ssize_t count;
1064
1065 mutex_lock(&smp_cpu_state_mutex);
1066 count = sprintf(buf, "%d\n", cpu_management);
1067 mutex_unlock(&smp_cpu_state_mutex);
1068 return count;
1069}
1070
1071static ssize_t dispatching_store(struct sysdev_class *dev,
1072 struct sysdev_class_attribute *attr,
1073 const char *buf,
1074 size_t count)
1075{
1076 int val, rc;
1077 char delim;
1078
1079 if (sscanf(buf, "%d %c", &val, &delim) != 1)
1080 return -EINVAL;
1081 if (val != 0 && val != 1)
1082 return -EINVAL;
1083 rc = 0;
1084 get_online_cpus();
1085 mutex_lock(&smp_cpu_state_mutex);
1086 if (cpu_management == val)
1087 goto out;
1088 rc = topology_set_cpu_management(val);
1089 if (!rc)
1090 cpu_management = val;
1091out:
1092 mutex_unlock(&smp_cpu_state_mutex);
1093 put_online_cpus();
1094 return rc ? rc : count;
1095}
1096static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
1097 dispatching_store);
1098
1099static int __init topology_init(void)
1100{
1101 int cpu;
1102 int rc;
1103
1104 register_cpu_notifier(&smp_cpu_nb);
1105
1106#ifdef CONFIG_HOTPLUG_CPU
1107 rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_rescan);
1108 if (rc)
1109 return rc;
1110#endif
1111 rc = sysdev_class_create_file(&cpu_sysdev_class, &attr_dispatching);
1112 if (rc)
1113 return rc;
1114 for_each_present_cpu(cpu) {
1115 rc = smp_add_present_cpu(cpu);
1116 if (rc)
1117 return rc;
1118 }
1119 return 0;
1120}
1121subsys_initcall(topology_init);
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
50enum {
51 ec_schedule = 0,
52 ec_call_function_single,
53 ec_stop_cpu,
54};
55
56enum {
57 CPU_STATE_STANDBY,
58 CPU_STATE_CONFIGURED,
59};
60
61struct pcpu {
62 struct cpu *cpu;
63 struct _lowcore *lowcore; /* lowcore page(s) for the cpu */
64 unsigned long async_stack; /* async stack for the cpu */
65 unsigned long panic_stack; /* panic stack for the cpu */
66 unsigned long ec_mask; /* bit mask for ec_xxx functions */
67 int state; /* physical cpu state */
68 int polarization; /* physical polarization */
69 u16 address; /* physical cpu address */
70};
71
72static u8 boot_cpu_type;
73static u16 boot_cpu_address;
74static struct pcpu pcpu_devices[NR_CPUS];
75
76/*
77 * The smp_cpu_state_mutex must be held when changing the state or polarization
78 * member of a pcpu data structure within the pcpu_devices arreay.
79 */
80DEFINE_MUTEX(smp_cpu_state_mutex);
81
82/*
83 * Signal processor helper functions.
84 */
85static inline int __pcpu_sigp_relax(u16 addr, u8 order, u32 parm, u32 *status)
86{
87 int cc;
88
89 while (1) {
90 cc = __pcpu_sigp(addr, order, parm, NULL);
91 if (cc != SIGP_CC_BUSY)
92 return cc;
93 cpu_relax();
94 }
95}
96
97static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
98{
99 int cc, retry;
100
101 for (retry = 0; ; retry++) {
102 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
103 if (cc != SIGP_CC_BUSY)
104 break;
105 if (retry >= 3)
106 udelay(10);
107 }
108 return cc;
109}
110
111static inline int pcpu_stopped(struct pcpu *pcpu)
112{
113 u32 uninitialized_var(status);
114
115 if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
116 0, &status) != SIGP_CC_STATUS_STORED)
117 return 0;
118 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
119}
120
121static inline int pcpu_running(struct pcpu *pcpu)
122{
123 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
124 0, NULL) != SIGP_CC_STATUS_STORED)
125 return 1;
126 /* Status stored condition code is equivalent to cpu not running. */
127 return 0;
128}
129
130/*
131 * Find struct pcpu by cpu address.
132 */
133static struct pcpu *pcpu_find_address(const struct cpumask *mask, int address)
134{
135 int cpu;
136
137 for_each_cpu(cpu, mask)
138 if (pcpu_devices[cpu].address == address)
139 return pcpu_devices + cpu;
140 return NULL;
141}
142
143static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
144{
145 int order;
146
147 if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
148 return;
149 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
150 pcpu_sigp_retry(pcpu, order, 0);
151}
152
153static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
154{
155 struct _lowcore *lc;
156
157 if (pcpu != &pcpu_devices[0]) {
158 pcpu->lowcore = (struct _lowcore *)
159 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
160 pcpu->async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
161 pcpu->panic_stack = __get_free_page(GFP_KERNEL);
162 if (!pcpu->lowcore || !pcpu->panic_stack || !pcpu->async_stack)
163 goto out;
164 }
165 lc = pcpu->lowcore;
166 memcpy(lc, &S390_lowcore, 512);
167 memset((char *) lc + 512, 0, sizeof(*lc) - 512);
168 lc->async_stack = pcpu->async_stack + ASYNC_SIZE
169 - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
170 lc->panic_stack = pcpu->panic_stack + PAGE_SIZE
171 - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
172 lc->cpu_nr = cpu;
173#ifndef CONFIG_64BIT
174 if (MACHINE_HAS_IEEE) {
175 lc->extended_save_area_addr = get_zeroed_page(GFP_KERNEL);
176 if (!lc->extended_save_area_addr)
177 goto out;
178 }
179#else
180 if (vdso_alloc_per_cpu(lc))
181 goto out;
182#endif
183 lowcore_ptr[cpu] = lc;
184 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
185 return 0;
186out:
187 if (pcpu != &pcpu_devices[0]) {
188 free_page(pcpu->panic_stack);
189 free_pages(pcpu->async_stack, ASYNC_ORDER);
190 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
191 }
192 return -ENOMEM;
193}
194
195#ifdef CONFIG_HOTPLUG_CPU
196
197static void pcpu_free_lowcore(struct pcpu *pcpu)
198{
199 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
200 lowcore_ptr[pcpu - pcpu_devices] = NULL;
201#ifndef CONFIG_64BIT
202 if (MACHINE_HAS_IEEE) {
203 struct _lowcore *lc = pcpu->lowcore;
204
205 free_page((unsigned long) lc->extended_save_area_addr);
206 lc->extended_save_area_addr = 0;
207 }
208#else
209 vdso_free_per_cpu(pcpu->lowcore);
210#endif
211 if (pcpu != &pcpu_devices[0]) {
212 free_page(pcpu->panic_stack);
213 free_pages(pcpu->async_stack, ASYNC_ORDER);
214 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
215 }
216}
217
218#endif /* CONFIG_HOTPLUG_CPU */
219
220static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
221{
222 struct _lowcore *lc = pcpu->lowcore;
223
224 if (MACHINE_HAS_TLB_LC)
225 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
226 cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
227 atomic_inc(&init_mm.context.attach_count);
228 lc->cpu_nr = cpu;
229 lc->percpu_offset = __per_cpu_offset[cpu];
230 lc->kernel_asce = S390_lowcore.kernel_asce;
231 lc->machine_flags = S390_lowcore.machine_flags;
232 lc->ftrace_func = S390_lowcore.ftrace_func;
233 lc->user_timer = lc->system_timer = lc->steal_timer = 0;
234 __ctl_store(lc->cregs_save_area, 0, 15);
235 save_access_regs((unsigned int *) lc->access_regs_save_area);
236 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
237 MAX_FACILITY_BIT/8);
238}
239
240static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
241{
242 struct _lowcore *lc = pcpu->lowcore;
243 struct thread_info *ti = task_thread_info(tsk);
244
245 lc->kernel_stack = (unsigned long) task_stack_page(tsk)
246 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
247 lc->thread_info = (unsigned long) task_thread_info(tsk);
248 lc->current_task = (unsigned long) tsk;
249 lc->user_timer = ti->user_timer;
250 lc->system_timer = ti->system_timer;
251 lc->steal_timer = 0;
252}
253
254static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
255{
256 struct _lowcore *lc = pcpu->lowcore;
257
258 lc->restart_stack = lc->kernel_stack;
259 lc->restart_fn = (unsigned long) func;
260 lc->restart_data = (unsigned long) data;
261 lc->restart_source = -1UL;
262 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
263}
264
265/*
266 * Call function via PSW restart on pcpu and stop the current cpu.
267 */
268static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
269 void *data, unsigned long stack)
270{
271 struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
272 unsigned long source_cpu = stap();
273
274 __load_psw_mask(PSW_KERNEL_BITS);
275 if (pcpu->address == source_cpu)
276 func(data); /* should not return */
277 /* Stop target cpu (if func returns this stops the current cpu). */
278 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
279 /* Restart func on the target cpu and stop the current cpu. */
280 mem_assign_absolute(lc->restart_stack, stack);
281 mem_assign_absolute(lc->restart_fn, (unsigned long) func);
282 mem_assign_absolute(lc->restart_data, (unsigned long) data);
283 mem_assign_absolute(lc->restart_source, source_cpu);
284 asm volatile(
285 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
286 " brc 2,0b # busy, try again\n"
287 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
288 " brc 2,1b # busy, try again\n"
289 : : "d" (pcpu->address), "d" (source_cpu),
290 "K" (SIGP_RESTART), "K" (SIGP_STOP)
291 : "0", "1", "cc");
292 for (;;) ;
293}
294
295/*
296 * Call function on an online CPU.
297 */
298void smp_call_online_cpu(void (*func)(void *), void *data)
299{
300 struct pcpu *pcpu;
301
302 /* Use the current cpu if it is online. */
303 pcpu = pcpu_find_address(cpu_online_mask, stap());
304 if (!pcpu)
305 /* Use the first online cpu. */
306 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
307 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
308}
309
310/*
311 * Call function on the ipl CPU.
312 */
313void smp_call_ipl_cpu(void (*func)(void *), void *data)
314{
315 pcpu_delegate(&pcpu_devices[0], func, data,
316 pcpu_devices->panic_stack + PAGE_SIZE);
317}
318
319int smp_find_processor_id(u16 address)
320{
321 int cpu;
322
323 for_each_present_cpu(cpu)
324 if (pcpu_devices[cpu].address == address)
325 return cpu;
326 return -1;
327}
328
329int smp_vcpu_scheduled(int cpu)
330{
331 return pcpu_running(pcpu_devices + cpu);
332}
333
334void smp_yield(void)
335{
336 if (MACHINE_HAS_DIAG44)
337 asm volatile("diag 0,0,0x44");
338}
339
340void smp_yield_cpu(int cpu)
341{
342 if (MACHINE_HAS_DIAG9C)
343 asm volatile("diag %0,0,0x9c"
344 : : "d" (pcpu_devices[cpu].address));
345 else if (MACHINE_HAS_DIAG44)
346 asm volatile("diag 0,0,0x44");
347}
348
349/*
350 * Send cpus emergency shutdown signal. This gives the cpus the
351 * opportunity to complete outstanding interrupts.
352 */
353static void smp_emergency_stop(cpumask_t *cpumask)
354{
355 u64 end;
356 int cpu;
357
358 end = get_tod_clock() + (1000000UL << 12);
359 for_each_cpu(cpu, cpumask) {
360 struct pcpu *pcpu = pcpu_devices + cpu;
361 set_bit(ec_stop_cpu, &pcpu->ec_mask);
362 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
363 0, NULL) == SIGP_CC_BUSY &&
364 get_tod_clock() < end)
365 cpu_relax();
366 }
367 while (get_tod_clock() < end) {
368 for_each_cpu(cpu, cpumask)
369 if (pcpu_stopped(pcpu_devices + cpu))
370 cpumask_clear_cpu(cpu, cpumask);
371 if (cpumask_empty(cpumask))
372 break;
373 cpu_relax();
374 }
375}
376
377/*
378 * Stop all cpus but the current one.
379 */
380void smp_send_stop(void)
381{
382 cpumask_t cpumask;
383 int cpu;
384
385 /* Disable all interrupts/machine checks */
386 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
387 trace_hardirqs_off();
388
389 debug_set_critical();
390 cpumask_copy(&cpumask, cpu_online_mask);
391 cpumask_clear_cpu(smp_processor_id(), &cpumask);
392
393 if (oops_in_progress)
394 smp_emergency_stop(&cpumask);
395
396 /* stop all processors */
397 for_each_cpu(cpu, &cpumask) {
398 struct pcpu *pcpu = pcpu_devices + cpu;
399 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
400 while (!pcpu_stopped(pcpu))
401 cpu_relax();
402 }
403}
404
405/*
406 * Stop the current cpu.
407 */
408void smp_stop_cpu(void)
409{
410 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
411 for (;;) ;
412}
413
414/*
415 * This is the main routine where commands issued by other
416 * cpus are handled.
417 */
418static void smp_handle_ext_call(void)
419{
420 unsigned long bits;
421
422 /* handle bit signal external calls */
423 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
424 if (test_bit(ec_stop_cpu, &bits))
425 smp_stop_cpu();
426 if (test_bit(ec_schedule, &bits))
427 scheduler_ipi();
428 if (test_bit(ec_call_function_single, &bits))
429 generic_smp_call_function_single_interrupt();
430}
431
432static void do_ext_call_interrupt(struct ext_code ext_code,
433 unsigned int param32, unsigned long param64)
434{
435 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
436 smp_handle_ext_call();
437}
438
439void arch_send_call_function_ipi_mask(const struct cpumask *mask)
440{
441 int cpu;
442
443 for_each_cpu(cpu, mask)
444 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
445}
446
447void arch_send_call_function_single_ipi(int cpu)
448{
449 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
450}
451
452#ifndef CONFIG_64BIT
453/*
454 * this function sends a 'purge tlb' signal to another CPU.
455 */
456static void smp_ptlb_callback(void *info)
457{
458 __tlb_flush_local();
459}
460
461void smp_ptlb_all(void)
462{
463 on_each_cpu(smp_ptlb_callback, NULL, 1);
464}
465EXPORT_SYMBOL(smp_ptlb_all);
466#endif /* ! CONFIG_64BIT */
467
468/*
469 * this function sends a 'reschedule' IPI to another CPU.
470 * it goes straight through and wastes no time serializing
471 * anything. Worst case is that we lose a reschedule ...
472 */
473void smp_send_reschedule(int cpu)
474{
475 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
476}
477
478/*
479 * parameter area for the set/clear control bit callbacks
480 */
481struct ec_creg_mask_parms {
482 unsigned long orval;
483 unsigned long andval;
484 int cr;
485};
486
487/*
488 * callback for setting/clearing control bits
489 */
490static void smp_ctl_bit_callback(void *info)
491{
492 struct ec_creg_mask_parms *pp = info;
493 unsigned long cregs[16];
494
495 __ctl_store(cregs, 0, 15);
496 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
497 __ctl_load(cregs, 0, 15);
498}
499
500/*
501 * Set a bit in a control register of all cpus
502 */
503void smp_ctl_set_bit(int cr, int bit)
504{
505 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
506
507 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
508}
509EXPORT_SYMBOL(smp_ctl_set_bit);
510
511/*
512 * Clear a bit in a control register of all cpus
513 */
514void smp_ctl_clear_bit(int cr, int bit)
515{
516 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
517
518 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
519}
520EXPORT_SYMBOL(smp_ctl_clear_bit);
521
522#if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_CRASH_DUMP)
523
524static void __init smp_get_save_area(int cpu, u16 address)
525{
526 void *lc = pcpu_devices[0].lowcore;
527 struct save_area *save_area;
528
529 if (is_kdump_kernel())
530 return;
531 if (!OLDMEM_BASE && (address == boot_cpu_address ||
532 ipl_info.type != IPL_TYPE_FCP_DUMP))
533 return;
534 save_area = dump_save_area_create(cpu);
535 if (!save_area)
536 panic("could not allocate memory for save area\n");
537#ifdef CONFIG_CRASH_DUMP
538 if (address == boot_cpu_address) {
539 /* Copy the registers of the boot cpu. */
540 copy_oldmem_page(1, (void *) save_area, sizeof(*save_area),
541 SAVE_AREA_BASE - PAGE_SIZE, 0);
542 return;
543 }
544#endif
545 /* Get the registers of a non-boot cpu. */
546 __pcpu_sigp_relax(address, SIGP_STOP_AND_STORE_STATUS, 0, NULL);
547 memcpy_real(save_area, lc + SAVE_AREA_BASE, sizeof(*save_area));
548}
549
550int smp_store_status(int cpu)
551{
552 struct pcpu *pcpu;
553
554 pcpu = pcpu_devices + cpu;
555 if (__pcpu_sigp_relax(pcpu->address, SIGP_STOP_AND_STORE_STATUS,
556 0, NULL) != SIGP_CC_ORDER_CODE_ACCEPTED)
557 return -EIO;
558 return 0;
559}
560
561#else /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */
562
563static inline void smp_get_save_area(int cpu, u16 address) { }
564
565#endif /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */
566
567void smp_cpu_set_polarization(int cpu, int val)
568{
569 pcpu_devices[cpu].polarization = val;
570}
571
572int smp_cpu_get_polarization(int cpu)
573{
574 return pcpu_devices[cpu].polarization;
575}
576
577static struct sclp_cpu_info *smp_get_cpu_info(void)
578{
579 static int use_sigp_detection;
580 struct sclp_cpu_info *info;
581 int address;
582
583 info = kzalloc(sizeof(*info), GFP_KERNEL);
584 if (info && (use_sigp_detection || sclp_get_cpu_info(info))) {
585 use_sigp_detection = 1;
586 for (address = 0; address <= MAX_CPU_ADDRESS; address++) {
587 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0, NULL) ==
588 SIGP_CC_NOT_OPERATIONAL)
589 continue;
590 info->cpu[info->configured].address = address;
591 info->configured++;
592 }
593 info->combined = info->configured;
594 }
595 return info;
596}
597
598static int smp_add_present_cpu(int cpu);
599
600static int __smp_rescan_cpus(struct sclp_cpu_info *info, int sysfs_add)
601{
602 struct pcpu *pcpu;
603 cpumask_t avail;
604 int cpu, nr, i;
605
606 nr = 0;
607 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
608 cpu = cpumask_first(&avail);
609 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) {
610 if (info->has_cpu_type && info->cpu[i].type != boot_cpu_type)
611 continue;
612 if (pcpu_find_address(cpu_present_mask, info->cpu[i].address))
613 continue;
614 pcpu = pcpu_devices + cpu;
615 pcpu->address = info->cpu[i].address;
616 pcpu->state = (i >= info->configured) ?
617 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED;
618 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
619 set_cpu_present(cpu, true);
620 if (sysfs_add && smp_add_present_cpu(cpu) != 0)
621 set_cpu_present(cpu, false);
622 else
623 nr++;
624 cpu = cpumask_next(cpu, &avail);
625 }
626 return nr;
627}
628
629static void __init smp_detect_cpus(void)
630{
631 unsigned int cpu, c_cpus, s_cpus;
632 struct sclp_cpu_info *info;
633
634 info = smp_get_cpu_info();
635 if (!info)
636 panic("smp_detect_cpus failed to allocate memory\n");
637 if (info->has_cpu_type) {
638 for (cpu = 0; cpu < info->combined; cpu++) {
639 if (info->cpu[cpu].address != boot_cpu_address)
640 continue;
641 /* The boot cpu dictates the cpu type. */
642 boot_cpu_type = info->cpu[cpu].type;
643 break;
644 }
645 }
646 c_cpus = s_cpus = 0;
647 for (cpu = 0; cpu < info->combined; cpu++) {
648 if (info->has_cpu_type && info->cpu[cpu].type != boot_cpu_type)
649 continue;
650 if (cpu < info->configured) {
651 smp_get_save_area(c_cpus, info->cpu[cpu].address);
652 c_cpus++;
653 } else
654 s_cpus++;
655 }
656 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
657 get_online_cpus();
658 __smp_rescan_cpus(info, 0);
659 put_online_cpus();
660 kfree(info);
661}
662
663/*
664 * Activate a secondary processor.
665 */
666static void smp_start_secondary(void *cpuvoid)
667{
668 S390_lowcore.last_update_clock = get_tod_clock();
669 S390_lowcore.restart_stack = (unsigned long) restart_stack;
670 S390_lowcore.restart_fn = (unsigned long) do_restart;
671 S390_lowcore.restart_data = 0;
672 S390_lowcore.restart_source = -1UL;
673 restore_access_regs(S390_lowcore.access_regs_save_area);
674 __ctl_load(S390_lowcore.cregs_save_area, 0, 15);
675 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
676 cpu_init();
677 preempt_disable();
678 init_cpu_timer();
679 init_cpu_vtimer();
680 pfault_init();
681 notify_cpu_starting(smp_processor_id());
682 set_cpu_online(smp_processor_id(), true);
683 inc_irq_stat(CPU_RST);
684 local_irq_enable();
685 cpu_startup_entry(CPUHP_ONLINE);
686}
687
688/* Upping and downing of CPUs */
689int __cpu_up(unsigned int cpu, struct task_struct *tidle)
690{
691 struct pcpu *pcpu;
692 int rc;
693
694 pcpu = pcpu_devices + cpu;
695 if (pcpu->state != CPU_STATE_CONFIGURED)
696 return -EIO;
697 if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) !=
698 SIGP_CC_ORDER_CODE_ACCEPTED)
699 return -EIO;
700
701 rc = pcpu_alloc_lowcore(pcpu, cpu);
702 if (rc)
703 return rc;
704 pcpu_prepare_secondary(pcpu, cpu);
705 pcpu_attach_task(pcpu, tidle);
706 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
707 while (!cpu_online(cpu))
708 cpu_relax();
709 return 0;
710}
711
712static unsigned int setup_possible_cpus __initdata;
713
714static int __init _setup_possible_cpus(char *s)
715{
716 get_option(&s, &setup_possible_cpus);
717 return 0;
718}
719early_param("possible_cpus", _setup_possible_cpus);
720
721#ifdef CONFIG_HOTPLUG_CPU
722
723int __cpu_disable(void)
724{
725 unsigned long cregs[16];
726
727 /* Handle possible pending IPIs */
728 smp_handle_ext_call();
729 set_cpu_online(smp_processor_id(), false);
730 /* Disable pseudo page faults on this cpu. */
731 pfault_fini();
732 /* Disable interrupt sources via control register. */
733 __ctl_store(cregs, 0, 15);
734 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
735 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
736 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
737 __ctl_load(cregs, 0, 15);
738 return 0;
739}
740
741void __cpu_die(unsigned int cpu)
742{
743 struct pcpu *pcpu;
744
745 /* Wait until target cpu is down */
746 pcpu = pcpu_devices + cpu;
747 while (!pcpu_stopped(pcpu))
748 cpu_relax();
749 pcpu_free_lowcore(pcpu);
750 atomic_dec(&init_mm.context.attach_count);
751 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
752 if (MACHINE_HAS_TLB_LC)
753 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
754}
755
756void __noreturn cpu_die(void)
757{
758 idle_task_exit();
759 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
760 for (;;) ;
761}
762
763#endif /* CONFIG_HOTPLUG_CPU */
764
765void __init smp_fill_possible_mask(void)
766{
767 unsigned int possible, sclp, cpu;
768
769 sclp = sclp_get_max_cpu() ?: nr_cpu_ids;
770 possible = setup_possible_cpus ?: nr_cpu_ids;
771 possible = min(possible, sclp);
772 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
773 set_cpu_possible(cpu, true);
774}
775
776void __init smp_prepare_cpus(unsigned int max_cpus)
777{
778 /* request the 0x1201 emergency signal external interrupt */
779 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
780 panic("Couldn't request external interrupt 0x1201");
781 /* request the 0x1202 external call external interrupt */
782 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
783 panic("Couldn't request external interrupt 0x1202");
784 smp_detect_cpus();
785}
786
787void __init smp_prepare_boot_cpu(void)
788{
789 struct pcpu *pcpu = pcpu_devices;
790
791 boot_cpu_address = stap();
792 pcpu->state = CPU_STATE_CONFIGURED;
793 pcpu->address = boot_cpu_address;
794 pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix();
795 pcpu->async_stack = S390_lowcore.async_stack - ASYNC_SIZE
796 + STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
797 pcpu->panic_stack = S390_lowcore.panic_stack - PAGE_SIZE
798 + STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
799 S390_lowcore.percpu_offset = __per_cpu_offset[0];
800 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
801 set_cpu_present(0, true);
802 set_cpu_online(0, true);
803}
804
805void __init smp_cpus_done(unsigned int max_cpus)
806{
807}
808
809void __init smp_setup_processor_id(void)
810{
811 S390_lowcore.cpu_nr = 0;
812}
813
814/*
815 * the frequency of the profiling timer can be changed
816 * by writing a multiplier value into /proc/profile.
817 *
818 * usually you want to run this on all CPUs ;)
819 */
820int setup_profiling_timer(unsigned int multiplier)
821{
822 return 0;
823}
824
825#ifdef CONFIG_HOTPLUG_CPU
826static ssize_t cpu_configure_show(struct device *dev,
827 struct device_attribute *attr, char *buf)
828{
829 ssize_t count;
830
831 mutex_lock(&smp_cpu_state_mutex);
832 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
833 mutex_unlock(&smp_cpu_state_mutex);
834 return count;
835}
836
837static ssize_t cpu_configure_store(struct device *dev,
838 struct device_attribute *attr,
839 const char *buf, size_t count)
840{
841 struct pcpu *pcpu;
842 int cpu, val, rc;
843 char delim;
844
845 if (sscanf(buf, "%d %c", &val, &delim) != 1)
846 return -EINVAL;
847 if (val != 0 && val != 1)
848 return -EINVAL;
849 get_online_cpus();
850 mutex_lock(&smp_cpu_state_mutex);
851 rc = -EBUSY;
852 /* disallow configuration changes of online cpus and cpu 0 */
853 cpu = dev->id;
854 if (cpu_online(cpu) || cpu == 0)
855 goto out;
856 pcpu = pcpu_devices + cpu;
857 rc = 0;
858 switch (val) {
859 case 0:
860 if (pcpu->state != CPU_STATE_CONFIGURED)
861 break;
862 rc = sclp_cpu_deconfigure(pcpu->address);
863 if (rc)
864 break;
865 pcpu->state = CPU_STATE_STANDBY;
866 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
867 topology_expect_change();
868 break;
869 case 1:
870 if (pcpu->state != CPU_STATE_STANDBY)
871 break;
872 rc = sclp_cpu_configure(pcpu->address);
873 if (rc)
874 break;
875 pcpu->state = CPU_STATE_CONFIGURED;
876 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
877 topology_expect_change();
878 break;
879 default:
880 break;
881 }
882out:
883 mutex_unlock(&smp_cpu_state_mutex);
884 put_online_cpus();
885 return rc ? rc : count;
886}
887static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
888#endif /* CONFIG_HOTPLUG_CPU */
889
890static ssize_t show_cpu_address(struct device *dev,
891 struct device_attribute *attr, char *buf)
892{
893 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
894}
895static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
896
897static struct attribute *cpu_common_attrs[] = {
898#ifdef CONFIG_HOTPLUG_CPU
899 &dev_attr_configure.attr,
900#endif
901 &dev_attr_address.attr,
902 NULL,
903};
904
905static struct attribute_group cpu_common_attr_group = {
906 .attrs = cpu_common_attrs,
907};
908
909static ssize_t show_idle_count(struct device *dev,
910 struct device_attribute *attr, char *buf)
911{
912 struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
913 unsigned long long idle_count;
914 unsigned int sequence;
915
916 do {
917 sequence = ACCESS_ONCE(idle->sequence);
918 idle_count = ACCESS_ONCE(idle->idle_count);
919 if (ACCESS_ONCE(idle->clock_idle_enter))
920 idle_count++;
921 } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence));
922 return sprintf(buf, "%llu\n", idle_count);
923}
924static DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL);
925
926static ssize_t show_idle_time(struct device *dev,
927 struct device_attribute *attr, char *buf)
928{
929 struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
930 unsigned long long now, idle_time, idle_enter, idle_exit;
931 unsigned int sequence;
932
933 do {
934 now = get_tod_clock();
935 sequence = ACCESS_ONCE(idle->sequence);
936 idle_time = ACCESS_ONCE(idle->idle_time);
937 idle_enter = ACCESS_ONCE(idle->clock_idle_enter);
938 idle_exit = ACCESS_ONCE(idle->clock_idle_exit);
939 } while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence));
940 idle_time += idle_enter ? ((idle_exit ? : now) - idle_enter) : 0;
941 return sprintf(buf, "%llu\n", idle_time >> 12);
942}
943static DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL);
944
945static struct attribute *cpu_online_attrs[] = {
946 &dev_attr_idle_count.attr,
947 &dev_attr_idle_time_us.attr,
948 NULL,
949};
950
951static struct attribute_group cpu_online_attr_group = {
952 .attrs = cpu_online_attrs,
953};
954
955static int smp_cpu_notify(struct notifier_block *self, unsigned long action,
956 void *hcpu)
957{
958 unsigned int cpu = (unsigned int)(long)hcpu;
959 struct cpu *c = pcpu_devices[cpu].cpu;
960 struct device *s = &c->dev;
961 int err = 0;
962
963 switch (action & ~CPU_TASKS_FROZEN) {
964 case CPU_ONLINE:
965 err = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
966 break;
967 case CPU_DEAD:
968 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
969 break;
970 }
971 return notifier_from_errno(err);
972}
973
974static int smp_add_present_cpu(int cpu)
975{
976 struct device *s;
977 struct cpu *c;
978 int rc;
979
980 c = kzalloc(sizeof(*c), GFP_KERNEL);
981 if (!c)
982 return -ENOMEM;
983 pcpu_devices[cpu].cpu = c;
984 s = &c->dev;
985 c->hotpluggable = 1;
986 rc = register_cpu(c, cpu);
987 if (rc)
988 goto out;
989 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
990 if (rc)
991 goto out_cpu;
992 if (cpu_online(cpu)) {
993 rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
994 if (rc)
995 goto out_online;
996 }
997 rc = topology_cpu_init(c);
998 if (rc)
999 goto out_topology;
1000 return 0;
1001
1002out_topology:
1003 if (cpu_online(cpu))
1004 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1005out_online:
1006 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1007out_cpu:
1008#ifdef CONFIG_HOTPLUG_CPU
1009 unregister_cpu(c);
1010#endif
1011out:
1012 return rc;
1013}
1014
1015#ifdef CONFIG_HOTPLUG_CPU
1016
1017int __ref smp_rescan_cpus(void)
1018{
1019 struct sclp_cpu_info *info;
1020 int nr;
1021
1022 info = smp_get_cpu_info();
1023 if (!info)
1024 return -ENOMEM;
1025 get_online_cpus();
1026 mutex_lock(&smp_cpu_state_mutex);
1027 nr = __smp_rescan_cpus(info, 1);
1028 mutex_unlock(&smp_cpu_state_mutex);
1029 put_online_cpus();
1030 kfree(info);
1031 if (nr)
1032 topology_schedule_update();
1033 return 0;
1034}
1035
1036static ssize_t __ref rescan_store(struct device *dev,
1037 struct device_attribute *attr,
1038 const char *buf,
1039 size_t count)
1040{
1041 int rc;
1042
1043 rc = smp_rescan_cpus();
1044 return rc ? rc : count;
1045}
1046static DEVICE_ATTR(rescan, 0200, NULL, rescan_store);
1047#endif /* CONFIG_HOTPLUG_CPU */
1048
1049static int __init s390_smp_init(void)
1050{
1051 int cpu, rc = 0;
1052
1053#ifdef CONFIG_HOTPLUG_CPU
1054 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1055 if (rc)
1056 return rc;
1057#endif
1058 cpu_notifier_register_begin();
1059 for_each_present_cpu(cpu) {
1060 rc = smp_add_present_cpu(cpu);
1061 if (rc)
1062 goto out;
1063 }
1064
1065 __hotcpu_notifier(smp_cpu_notify, 0);
1066
1067out:
1068 cpu_notifier_register_done();
1069 return rc;
1070}
1071subsys_initcall(s390_smp_init);