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