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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SMP related functions
4 *
5 * Copyright IBM Corp. 1999, 2012
6 * Author(s): Denis Joseph Barrow,
7 * Martin Schwidefsky <schwidefsky@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/memblock.h>
23#include <linux/export.h>
24#include <linux/init.h>
25#include <linux/mm.h>
26#include <linux/err.h>
27#include <linux/spinlock.h>
28#include <linux/kernel_stat.h>
29#include <linux/delay.h>
30#include <linux/interrupt.h>
31#include <linux/irqflags.h>
32#include <linux/irq_work.h>
33#include <linux/cpu.h>
34#include <linux/slab.h>
35#include <linux/sched/hotplug.h>
36#include <linux/sched/task_stack.h>
37#include <linux/crash_dump.h>
38#include <linux/kprobes.h>
39#include <asm/asm-offsets.h>
40#include <asm/diag.h>
41#include <asm/switch_to.h>
42#include <asm/facility.h>
43#include <asm/ipl.h>
44#include <asm/setup.h>
45#include <asm/irq.h>
46#include <asm/tlbflush.h>
47#include <asm/vtimer.h>
48#include <asm/abs_lowcore.h>
49#include <asm/sclp.h>
50#include <asm/debug.h>
51#include <asm/os_info.h>
52#include <asm/sigp.h>
53#include <asm/idle.h>
54#include <asm/nmi.h>
55#include <asm/stacktrace.h>
56#include <asm/topology.h>
57#include <asm/vdso.h>
58#include <asm/maccess.h>
59#include "entry.h"
60
61enum {
62 ec_schedule = 0,
63 ec_call_function_single,
64 ec_stop_cpu,
65 ec_mcck_pending,
66 ec_irq_work,
67};
68
69enum {
70 CPU_STATE_STANDBY,
71 CPU_STATE_CONFIGURED,
72};
73
74static DEFINE_PER_CPU(struct cpu *, cpu_device);
75
76struct pcpu {
77 unsigned long ec_mask; /* bit mask for ec_xxx functions */
78 unsigned long ec_clk; /* sigp timestamp for ec_xxx */
79 signed char state; /* physical cpu state */
80 signed char polarization; /* physical polarization */
81 u16 address; /* physical cpu address */
82};
83
84static u8 boot_core_type;
85static struct pcpu pcpu_devices[NR_CPUS];
86
87unsigned int smp_cpu_mt_shift;
88EXPORT_SYMBOL(smp_cpu_mt_shift);
89
90unsigned int smp_cpu_mtid;
91EXPORT_SYMBOL(smp_cpu_mtid);
92
93#ifdef CONFIG_CRASH_DUMP
94__vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
95#endif
96
97static unsigned int smp_max_threads __initdata = -1U;
98cpumask_t cpu_setup_mask;
99
100static int __init early_nosmt(char *s)
101{
102 smp_max_threads = 1;
103 return 0;
104}
105early_param("nosmt", early_nosmt);
106
107static int __init early_smt(char *s)
108{
109 get_option(&s, &smp_max_threads);
110 return 0;
111}
112early_param("smt", early_smt);
113
114/*
115 * The smp_cpu_state_mutex must be held when changing the state or polarization
116 * member of a pcpu data structure within the pcpu_devices arreay.
117 */
118DEFINE_MUTEX(smp_cpu_state_mutex);
119
120/*
121 * Signal processor helper functions.
122 */
123static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm)
124{
125 int cc;
126
127 while (1) {
128 cc = __pcpu_sigp(addr, order, parm, NULL);
129 if (cc != SIGP_CC_BUSY)
130 return cc;
131 cpu_relax();
132 }
133}
134
135static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
136{
137 int cc, retry;
138
139 for (retry = 0; ; retry++) {
140 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
141 if (cc != SIGP_CC_BUSY)
142 break;
143 if (retry >= 3)
144 udelay(10);
145 }
146 return cc;
147}
148
149static inline int pcpu_stopped(struct pcpu *pcpu)
150{
151 u32 status;
152
153 if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
154 0, &status) != SIGP_CC_STATUS_STORED)
155 return 0;
156 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
157}
158
159static inline int pcpu_running(struct pcpu *pcpu)
160{
161 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
162 0, NULL) != SIGP_CC_STATUS_STORED)
163 return 1;
164 /* Status stored condition code is equivalent to cpu not running. */
165 return 0;
166}
167
168/*
169 * Find struct pcpu by cpu address.
170 */
171static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address)
172{
173 int cpu;
174
175 for_each_cpu(cpu, mask)
176 if (pcpu_devices[cpu].address == address)
177 return pcpu_devices + cpu;
178 return NULL;
179}
180
181static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
182{
183 int order;
184
185 if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
186 return;
187 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
188 pcpu->ec_clk = get_tod_clock_fast();
189 pcpu_sigp_retry(pcpu, order, 0);
190}
191
192static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
193{
194 unsigned long async_stack, nodat_stack, mcck_stack;
195 struct lowcore *lc;
196
197 lc = (struct lowcore *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
198 nodat_stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
199 async_stack = stack_alloc();
200 mcck_stack = stack_alloc();
201 if (!lc || !nodat_stack || !async_stack || !mcck_stack)
202 goto out;
203 memcpy(lc, &S390_lowcore, 512);
204 memset((char *) lc + 512, 0, sizeof(*lc) - 512);
205 lc->async_stack = async_stack + STACK_INIT_OFFSET;
206 lc->nodat_stack = nodat_stack + STACK_INIT_OFFSET;
207 lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;
208 lc->cpu_nr = cpu;
209 lc->spinlock_lockval = arch_spin_lockval(cpu);
210 lc->spinlock_index = 0;
211 lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
212 lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
213 lc->preempt_count = PREEMPT_DISABLED;
214 if (nmi_alloc_mcesa(&lc->mcesad))
215 goto out;
216 if (abs_lowcore_map(cpu, lc, true))
217 goto out_mcesa;
218 lowcore_ptr[cpu] = lc;
219 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, __pa(lc));
220 return 0;
221
222out_mcesa:
223 nmi_free_mcesa(&lc->mcesad);
224out:
225 stack_free(mcck_stack);
226 stack_free(async_stack);
227 free_pages(nodat_stack, THREAD_SIZE_ORDER);
228 free_pages((unsigned long) lc, LC_ORDER);
229 return -ENOMEM;
230}
231
232static void pcpu_free_lowcore(struct pcpu *pcpu)
233{
234 unsigned long async_stack, nodat_stack, mcck_stack;
235 struct lowcore *lc;
236 int cpu;
237
238 cpu = pcpu - pcpu_devices;
239 lc = lowcore_ptr[cpu];
240 nodat_stack = lc->nodat_stack - STACK_INIT_OFFSET;
241 async_stack = lc->async_stack - STACK_INIT_OFFSET;
242 mcck_stack = lc->mcck_stack - STACK_INIT_OFFSET;
243 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
244 lowcore_ptr[cpu] = NULL;
245 abs_lowcore_unmap(cpu);
246 nmi_free_mcesa(&lc->mcesad);
247 stack_free(async_stack);
248 stack_free(mcck_stack);
249 free_pages(nodat_stack, THREAD_SIZE_ORDER);
250 free_pages((unsigned long) lc, LC_ORDER);
251}
252
253static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
254{
255 struct lowcore *lc = lowcore_ptr[cpu];
256
257 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
258 cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
259 lc->cpu_nr = cpu;
260 lc->restart_flags = RESTART_FLAG_CTLREGS;
261 lc->spinlock_lockval = arch_spin_lockval(cpu);
262 lc->spinlock_index = 0;
263 lc->percpu_offset = __per_cpu_offset[cpu];
264 lc->kernel_asce = S390_lowcore.kernel_asce;
265 lc->user_asce = s390_invalid_asce;
266 lc->machine_flags = S390_lowcore.machine_flags;
267 lc->user_timer = lc->system_timer =
268 lc->steal_timer = lc->avg_steal_timer = 0;
269 __ctl_store(lc->cregs_save_area, 0, 15);
270 lc->cregs_save_area[1] = lc->kernel_asce;
271 lc->cregs_save_area[7] = lc->user_asce;
272 save_access_regs((unsigned int *) lc->access_regs_save_area);
273 arch_spin_lock_setup(cpu);
274}
275
276static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
277{
278 struct lowcore *lc;
279 int cpu;
280
281 cpu = pcpu - pcpu_devices;
282 lc = lowcore_ptr[cpu];
283 lc->kernel_stack = (unsigned long) task_stack_page(tsk)
284 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
285 lc->current_task = (unsigned long) tsk;
286 lc->lpp = LPP_MAGIC;
287 lc->current_pid = tsk->pid;
288 lc->user_timer = tsk->thread.user_timer;
289 lc->guest_timer = tsk->thread.guest_timer;
290 lc->system_timer = tsk->thread.system_timer;
291 lc->hardirq_timer = tsk->thread.hardirq_timer;
292 lc->softirq_timer = tsk->thread.softirq_timer;
293 lc->steal_timer = 0;
294}
295
296static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
297{
298 struct lowcore *lc;
299 int cpu;
300
301 cpu = pcpu - pcpu_devices;
302 lc = lowcore_ptr[cpu];
303 lc->restart_stack = lc->kernel_stack;
304 lc->restart_fn = (unsigned long) func;
305 lc->restart_data = (unsigned long) data;
306 lc->restart_source = -1U;
307 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
308}
309
310typedef void (pcpu_delegate_fn)(void *);
311
312/*
313 * Call function via PSW restart on pcpu and stop the current cpu.
314 */
315static void __pcpu_delegate(pcpu_delegate_fn *func, void *data)
316{
317 func(data); /* should not return */
318}
319
320static void pcpu_delegate(struct pcpu *pcpu,
321 pcpu_delegate_fn *func,
322 void *data, unsigned long stack)
323{
324 struct lowcore *lc, *abs_lc;
325 unsigned int source_cpu;
326 unsigned long flags;
327
328 lc = lowcore_ptr[pcpu - pcpu_devices];
329 source_cpu = stap();
330 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
331 if (pcpu->address == source_cpu) {
332 call_on_stack(2, stack, void, __pcpu_delegate,
333 pcpu_delegate_fn *, func, void *, data);
334 }
335 /* Stop target cpu (if func returns this stops the current cpu). */
336 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
337 /* Restart func on the target cpu and stop the current cpu. */
338 if (lc) {
339 lc->restart_stack = stack;
340 lc->restart_fn = (unsigned long)func;
341 lc->restart_data = (unsigned long)data;
342 lc->restart_source = source_cpu;
343 } else {
344 abs_lc = get_abs_lowcore(&flags);
345 abs_lc->restart_stack = stack;
346 abs_lc->restart_fn = (unsigned long)func;
347 abs_lc->restart_data = (unsigned long)data;
348 abs_lc->restart_source = source_cpu;
349 put_abs_lowcore(abs_lc, flags);
350 }
351 __bpon();
352 asm volatile(
353 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
354 " brc 2,0b # busy, try again\n"
355 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
356 " brc 2,1b # busy, try again\n"
357 : : "d" (pcpu->address), "d" (source_cpu),
358 "K" (SIGP_RESTART), "K" (SIGP_STOP)
359 : "0", "1", "cc");
360 for (;;) ;
361}
362
363/*
364 * Enable additional logical cpus for multi-threading.
365 */
366static int pcpu_set_smt(unsigned int mtid)
367{
368 int cc;
369
370 if (smp_cpu_mtid == mtid)
371 return 0;
372 cc = __pcpu_sigp(0, SIGP_SET_MULTI_THREADING, mtid, NULL);
373 if (cc == 0) {
374 smp_cpu_mtid = mtid;
375 smp_cpu_mt_shift = 0;
376 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift))
377 smp_cpu_mt_shift++;
378 pcpu_devices[0].address = stap();
379 }
380 return cc;
381}
382
383/*
384 * Call function on an online CPU.
385 */
386void smp_call_online_cpu(void (*func)(void *), void *data)
387{
388 struct pcpu *pcpu;
389
390 /* Use the current cpu if it is online. */
391 pcpu = pcpu_find_address(cpu_online_mask, stap());
392 if (!pcpu)
393 /* Use the first online cpu. */
394 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
395 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
396}
397
398/*
399 * Call function on the ipl CPU.
400 */
401void smp_call_ipl_cpu(void (*func)(void *), void *data)
402{
403 struct lowcore *lc = lowcore_ptr[0];
404
405 if (pcpu_devices[0].address == stap())
406 lc = &S390_lowcore;
407
408 pcpu_delegate(&pcpu_devices[0], func, data,
409 lc->nodat_stack);
410}
411
412int smp_find_processor_id(u16 address)
413{
414 int cpu;
415
416 for_each_present_cpu(cpu)
417 if (pcpu_devices[cpu].address == address)
418 return cpu;
419 return -1;
420}
421
422void schedule_mcck_handler(void)
423{
424 pcpu_ec_call(pcpu_devices + smp_processor_id(), ec_mcck_pending);
425}
426
427bool notrace arch_vcpu_is_preempted(int cpu)
428{
429 if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu))
430 return false;
431 if (pcpu_running(pcpu_devices + cpu))
432 return false;
433 return true;
434}
435EXPORT_SYMBOL(arch_vcpu_is_preempted);
436
437void notrace smp_yield_cpu(int cpu)
438{
439 if (!MACHINE_HAS_DIAG9C)
440 return;
441 diag_stat_inc_norecursion(DIAG_STAT_X09C);
442 asm volatile("diag %0,0,0x9c"
443 : : "d" (pcpu_devices[cpu].address));
444}
445EXPORT_SYMBOL_GPL(smp_yield_cpu);
446
447/*
448 * Send cpus emergency shutdown signal. This gives the cpus the
449 * opportunity to complete outstanding interrupts.
450 */
451void notrace smp_emergency_stop(void)
452{
453 static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED;
454 static cpumask_t cpumask;
455 u64 end;
456 int cpu;
457
458 arch_spin_lock(&lock);
459 cpumask_copy(&cpumask, cpu_online_mask);
460 cpumask_clear_cpu(smp_processor_id(), &cpumask);
461
462 end = get_tod_clock() + (1000000UL << 12);
463 for_each_cpu(cpu, &cpumask) {
464 struct pcpu *pcpu = pcpu_devices + cpu;
465 set_bit(ec_stop_cpu, &pcpu->ec_mask);
466 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
467 0, NULL) == SIGP_CC_BUSY &&
468 get_tod_clock() < end)
469 cpu_relax();
470 }
471 while (get_tod_clock() < end) {
472 for_each_cpu(cpu, &cpumask)
473 if (pcpu_stopped(pcpu_devices + cpu))
474 cpumask_clear_cpu(cpu, &cpumask);
475 if (cpumask_empty(&cpumask))
476 break;
477 cpu_relax();
478 }
479 arch_spin_unlock(&lock);
480}
481NOKPROBE_SYMBOL(smp_emergency_stop);
482
483/*
484 * Stop all cpus but the current one.
485 */
486void smp_send_stop(void)
487{
488 int cpu;
489
490 /* Disable all interrupts/machine checks */
491 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
492 trace_hardirqs_off();
493
494 debug_set_critical();
495
496 if (oops_in_progress)
497 smp_emergency_stop();
498
499 /* stop all processors */
500 for_each_online_cpu(cpu) {
501 if (cpu == smp_processor_id())
502 continue;
503 pcpu_sigp_retry(pcpu_devices + cpu, SIGP_STOP, 0);
504 while (!pcpu_stopped(pcpu_devices + cpu))
505 cpu_relax();
506 }
507}
508
509/*
510 * This is the main routine where commands issued by other
511 * cpus are handled.
512 */
513static void smp_handle_ext_call(void)
514{
515 unsigned long bits;
516
517 /* handle bit signal external calls */
518 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
519 if (test_bit(ec_stop_cpu, &bits))
520 smp_stop_cpu();
521 if (test_bit(ec_schedule, &bits))
522 scheduler_ipi();
523 if (test_bit(ec_call_function_single, &bits))
524 generic_smp_call_function_single_interrupt();
525 if (test_bit(ec_mcck_pending, &bits))
526 __s390_handle_mcck();
527 if (test_bit(ec_irq_work, &bits))
528 irq_work_run();
529}
530
531static void do_ext_call_interrupt(struct ext_code ext_code,
532 unsigned int param32, unsigned long param64)
533{
534 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
535 smp_handle_ext_call();
536}
537
538void arch_send_call_function_ipi_mask(const struct cpumask *mask)
539{
540 int cpu;
541
542 for_each_cpu(cpu, mask)
543 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
544}
545
546void arch_send_call_function_single_ipi(int cpu)
547{
548 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
549}
550
551/*
552 * this function sends a 'reschedule' IPI to another CPU.
553 * it goes straight through and wastes no time serializing
554 * anything. Worst case is that we lose a reschedule ...
555 */
556void smp_send_reschedule(int cpu)
557{
558 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
559}
560
561#ifdef CONFIG_IRQ_WORK
562void arch_irq_work_raise(void)
563{
564 pcpu_ec_call(pcpu_devices + smp_processor_id(), ec_irq_work);
565}
566#endif
567
568/*
569 * parameter area for the set/clear control bit callbacks
570 */
571struct ec_creg_mask_parms {
572 unsigned long orval;
573 unsigned long andval;
574 int cr;
575};
576
577/*
578 * callback for setting/clearing control bits
579 */
580static void smp_ctl_bit_callback(void *info)
581{
582 struct ec_creg_mask_parms *pp = info;
583 unsigned long cregs[16];
584
585 __ctl_store(cregs, 0, 15);
586 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
587 __ctl_load(cregs, 0, 15);
588}
589
590static DEFINE_SPINLOCK(ctl_lock);
591
592void smp_ctl_set_clear_bit(int cr, int bit, bool set)
593{
594 struct ec_creg_mask_parms parms = { .cr = cr, };
595 struct lowcore *abs_lc;
596 unsigned long flags;
597 u64 ctlreg;
598
599 if (set) {
600 parms.orval = 1UL << bit;
601 parms.andval = -1UL;
602 } else {
603 parms.orval = 0;
604 parms.andval = ~(1UL << bit);
605 }
606 spin_lock(&ctl_lock);
607 abs_lc = get_abs_lowcore(&flags);
608 ctlreg = abs_lc->cregs_save_area[cr];
609 ctlreg = (ctlreg & parms.andval) | parms.orval;
610 abs_lc->cregs_save_area[cr] = ctlreg;
611 put_abs_lowcore(abs_lc, flags);
612 spin_unlock(&ctl_lock);
613 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
614}
615EXPORT_SYMBOL(smp_ctl_set_clear_bit);
616
617#ifdef CONFIG_CRASH_DUMP
618
619int smp_store_status(int cpu)
620{
621 struct lowcore *lc;
622 struct pcpu *pcpu;
623 unsigned long pa;
624
625 pcpu = pcpu_devices + cpu;
626 lc = lowcore_ptr[cpu];
627 pa = __pa(&lc->floating_pt_save_area);
628 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS,
629 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
630 return -EIO;
631 if (!MACHINE_HAS_VX && !MACHINE_HAS_GS)
632 return 0;
633 pa = lc->mcesad & MCESA_ORIGIN_MASK;
634 if (MACHINE_HAS_GS)
635 pa |= lc->mcesad & MCESA_LC_MASK;
636 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
637 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
638 return -EIO;
639 return 0;
640}
641
642/*
643 * Collect CPU state of the previous, crashed system.
644 * There are four cases:
645 * 1) standard zfcp/nvme dump
646 * condition: OLDMEM_BASE == NULL && is_ipl_type_dump() == true
647 * The state for all CPUs except the boot CPU needs to be collected
648 * with sigp stop-and-store-status. The boot CPU state is located in
649 * the absolute lowcore of the memory stored in the HSA. The zcore code
650 * will copy the boot CPU state from the HSA.
651 * 2) stand-alone kdump for SCSI/NVMe (zfcp/nvme dump with swapped memory)
652 * condition: OLDMEM_BASE != NULL && is_ipl_type_dump() == true
653 * The state for all CPUs except the boot CPU needs to be collected
654 * with sigp stop-and-store-status. The firmware or the boot-loader
655 * stored the registers of the boot CPU in the absolute lowcore in the
656 * memory of the old system.
657 * 3) kdump and the old kernel did not store the CPU state,
658 * or stand-alone kdump for DASD
659 * condition: OLDMEM_BASE != NULL && !is_kdump_kernel()
660 * The state for all CPUs except the boot CPU needs to be collected
661 * with sigp stop-and-store-status. The kexec code or the boot-loader
662 * stored the registers of the boot CPU in the memory of the old system.
663 * 4) kdump and the old kernel stored the CPU state
664 * condition: OLDMEM_BASE != NULL && is_kdump_kernel()
665 * This case does not exist for s390 anymore, setup_arch explicitly
666 * deactivates the elfcorehdr= kernel parameter
667 */
668static bool dump_available(void)
669{
670 return oldmem_data.start || is_ipl_type_dump();
671}
672
673void __init smp_save_dump_ipl_cpu(void)
674{
675 struct save_area *sa;
676 void *regs;
677
678 if (!dump_available())
679 return;
680 sa = save_area_alloc(true);
681 regs = memblock_alloc(512, 8);
682 if (!sa || !regs)
683 panic("could not allocate memory for boot CPU save area\n");
684 copy_oldmem_kernel(regs, __LC_FPREGS_SAVE_AREA, 512);
685 save_area_add_regs(sa, regs);
686 memblock_free(regs, 512);
687 if (MACHINE_HAS_VX)
688 save_area_add_vxrs(sa, boot_cpu_vector_save_area);
689}
690
691void __init smp_save_dump_secondary_cpus(void)
692{
693 int addr, boot_cpu_addr, max_cpu_addr;
694 struct save_area *sa;
695 void *page;
696
697 if (!dump_available())
698 return;
699 /* Allocate a page as dumping area for the store status sigps */
700 page = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
701 if (!page)
702 panic("ERROR: Failed to allocate %lx bytes below %lx\n",
703 PAGE_SIZE, 1UL << 31);
704
705 /* Set multi-threading state to the previous system. */
706 pcpu_set_smt(sclp.mtid_prev);
707 boot_cpu_addr = stap();
708 max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;
709 for (addr = 0; addr <= max_cpu_addr; addr++) {
710 if (addr == boot_cpu_addr)
711 continue;
712 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==
713 SIGP_CC_NOT_OPERATIONAL)
714 continue;
715 sa = save_area_alloc(false);
716 if (!sa)
717 panic("could not allocate memory for save area\n");
718 __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, __pa(page));
719 save_area_add_regs(sa, page);
720 if (MACHINE_HAS_VX) {
721 __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, __pa(page));
722 save_area_add_vxrs(sa, page);
723 }
724 }
725 memblock_free(page, PAGE_SIZE);
726 diag_amode31_ops.diag308_reset();
727 pcpu_set_smt(0);
728}
729#endif /* CONFIG_CRASH_DUMP */
730
731void smp_cpu_set_polarization(int cpu, int val)
732{
733 pcpu_devices[cpu].polarization = val;
734}
735
736int smp_cpu_get_polarization(int cpu)
737{
738 return pcpu_devices[cpu].polarization;
739}
740
741int smp_cpu_get_cpu_address(int cpu)
742{
743 return pcpu_devices[cpu].address;
744}
745
746static void __ref smp_get_core_info(struct sclp_core_info *info, int early)
747{
748 static int use_sigp_detection;
749 int address;
750
751 if (use_sigp_detection || sclp_get_core_info(info, early)) {
752 use_sigp_detection = 1;
753 for (address = 0;
754 address < (SCLP_MAX_CORES << smp_cpu_mt_shift);
755 address += (1U << smp_cpu_mt_shift)) {
756 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) ==
757 SIGP_CC_NOT_OPERATIONAL)
758 continue;
759 info->core[info->configured].core_id =
760 address >> smp_cpu_mt_shift;
761 info->configured++;
762 }
763 info->combined = info->configured;
764 }
765}
766
767static int smp_add_present_cpu(int cpu);
768
769static int smp_add_core(struct sclp_core_entry *core, cpumask_t *avail,
770 bool configured, bool early)
771{
772 struct pcpu *pcpu;
773 int cpu, nr, i;
774 u16 address;
775
776 nr = 0;
777 if (sclp.has_core_type && core->type != boot_core_type)
778 return nr;
779 cpu = cpumask_first(avail);
780 address = core->core_id << smp_cpu_mt_shift;
781 for (i = 0; (i <= smp_cpu_mtid) && (cpu < nr_cpu_ids); i++) {
782 if (pcpu_find_address(cpu_present_mask, address + i))
783 continue;
784 pcpu = pcpu_devices + cpu;
785 pcpu->address = address + i;
786 if (configured)
787 pcpu->state = CPU_STATE_CONFIGURED;
788 else
789 pcpu->state = CPU_STATE_STANDBY;
790 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
791 set_cpu_present(cpu, true);
792 if (!early && smp_add_present_cpu(cpu) != 0)
793 set_cpu_present(cpu, false);
794 else
795 nr++;
796 cpumask_clear_cpu(cpu, avail);
797 cpu = cpumask_next(cpu, avail);
798 }
799 return nr;
800}
801
802static int __smp_rescan_cpus(struct sclp_core_info *info, bool early)
803{
804 struct sclp_core_entry *core;
805 static cpumask_t avail;
806 bool configured;
807 u16 core_id;
808 int nr, i;
809
810 cpus_read_lock();
811 mutex_lock(&smp_cpu_state_mutex);
812 nr = 0;
813 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
814 /*
815 * Add IPL core first (which got logical CPU number 0) to make sure
816 * that all SMT threads get subsequent logical CPU numbers.
817 */
818 if (early) {
819 core_id = pcpu_devices[0].address >> smp_cpu_mt_shift;
820 for (i = 0; i < info->configured; i++) {
821 core = &info->core[i];
822 if (core->core_id == core_id) {
823 nr += smp_add_core(core, &avail, true, early);
824 break;
825 }
826 }
827 }
828 for (i = 0; i < info->combined; i++) {
829 configured = i < info->configured;
830 nr += smp_add_core(&info->core[i], &avail, configured, early);
831 }
832 mutex_unlock(&smp_cpu_state_mutex);
833 cpus_read_unlock();
834 return nr;
835}
836
837void __init smp_detect_cpus(void)
838{
839 unsigned int cpu, mtid, c_cpus, s_cpus;
840 struct sclp_core_info *info;
841 u16 address;
842
843 /* Get CPU information */
844 info = memblock_alloc(sizeof(*info), 8);
845 if (!info)
846 panic("%s: Failed to allocate %zu bytes align=0x%x\n",
847 __func__, sizeof(*info), 8);
848 smp_get_core_info(info, 1);
849 /* Find boot CPU type */
850 if (sclp.has_core_type) {
851 address = stap();
852 for (cpu = 0; cpu < info->combined; cpu++)
853 if (info->core[cpu].core_id == address) {
854 /* The boot cpu dictates the cpu type. */
855 boot_core_type = info->core[cpu].type;
856 break;
857 }
858 if (cpu >= info->combined)
859 panic("Could not find boot CPU type");
860 }
861
862 /* Set multi-threading state for the current system */
863 mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp;
864 mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1;
865 pcpu_set_smt(mtid);
866
867 /* Print number of CPUs */
868 c_cpus = s_cpus = 0;
869 for (cpu = 0; cpu < info->combined; cpu++) {
870 if (sclp.has_core_type &&
871 info->core[cpu].type != boot_core_type)
872 continue;
873 if (cpu < info->configured)
874 c_cpus += smp_cpu_mtid + 1;
875 else
876 s_cpus += smp_cpu_mtid + 1;
877 }
878 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
879
880 /* Add CPUs present at boot */
881 __smp_rescan_cpus(info, true);
882 memblock_free(info, sizeof(*info));
883}
884
885/*
886 * Activate a secondary processor.
887 */
888static void smp_start_secondary(void *cpuvoid)
889{
890 int cpu = raw_smp_processor_id();
891
892 S390_lowcore.last_update_clock = get_tod_clock();
893 S390_lowcore.restart_stack = (unsigned long)restart_stack;
894 S390_lowcore.restart_fn = (unsigned long)do_restart;
895 S390_lowcore.restart_data = 0;
896 S390_lowcore.restart_source = -1U;
897 S390_lowcore.restart_flags = 0;
898 restore_access_regs(S390_lowcore.access_regs_save_area);
899 cpu_init();
900 rcu_cpu_starting(cpu);
901 init_cpu_timer();
902 vtime_init();
903 vdso_getcpu_init();
904 pfault_init();
905 cpumask_set_cpu(cpu, &cpu_setup_mask);
906 update_cpu_masks();
907 notify_cpu_starting(cpu);
908 if (topology_cpu_dedicated(cpu))
909 set_cpu_flag(CIF_DEDICATED_CPU);
910 else
911 clear_cpu_flag(CIF_DEDICATED_CPU);
912 set_cpu_online(cpu, true);
913 inc_irq_stat(CPU_RST);
914 local_irq_enable();
915 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
916}
917
918/* Upping and downing of CPUs */
919int __cpu_up(unsigned int cpu, struct task_struct *tidle)
920{
921 struct pcpu *pcpu = pcpu_devices + cpu;
922 int rc;
923
924 if (pcpu->state != CPU_STATE_CONFIGURED)
925 return -EIO;
926 if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) !=
927 SIGP_CC_ORDER_CODE_ACCEPTED)
928 return -EIO;
929
930 rc = pcpu_alloc_lowcore(pcpu, cpu);
931 if (rc)
932 return rc;
933 pcpu_prepare_secondary(pcpu, cpu);
934 pcpu_attach_task(pcpu, tidle);
935 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
936 /* Wait until cpu puts itself in the online & active maps */
937 while (!cpu_online(cpu))
938 cpu_relax();
939 return 0;
940}
941
942static unsigned int setup_possible_cpus __initdata;
943
944static int __init _setup_possible_cpus(char *s)
945{
946 get_option(&s, &setup_possible_cpus);
947 return 0;
948}
949early_param("possible_cpus", _setup_possible_cpus);
950
951int __cpu_disable(void)
952{
953 unsigned long cregs[16];
954 int cpu;
955
956 /* Handle possible pending IPIs */
957 smp_handle_ext_call();
958 cpu = smp_processor_id();
959 set_cpu_online(cpu, false);
960 cpumask_clear_cpu(cpu, &cpu_setup_mask);
961 update_cpu_masks();
962 /* Disable pseudo page faults on this cpu. */
963 pfault_fini();
964 /* Disable interrupt sources via control register. */
965 __ctl_store(cregs, 0, 15);
966 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
967 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
968 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
969 __ctl_load(cregs, 0, 15);
970 clear_cpu_flag(CIF_NOHZ_DELAY);
971 return 0;
972}
973
974void __cpu_die(unsigned int cpu)
975{
976 struct pcpu *pcpu;
977
978 /* Wait until target cpu is down */
979 pcpu = pcpu_devices + cpu;
980 while (!pcpu_stopped(pcpu))
981 cpu_relax();
982 pcpu_free_lowcore(pcpu);
983 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
984 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
985}
986
987void __noreturn cpu_die(void)
988{
989 idle_task_exit();
990 __bpon();
991 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
992 for (;;) ;
993}
994
995void __init smp_fill_possible_mask(void)
996{
997 unsigned int possible, sclp_max, cpu;
998
999 sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1;
1000 sclp_max = min(smp_max_threads, sclp_max);
1001 sclp_max = (sclp.max_cores * sclp_max) ?: nr_cpu_ids;
1002 possible = setup_possible_cpus ?: nr_cpu_ids;
1003 possible = min(possible, sclp_max);
1004 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
1005 set_cpu_possible(cpu, true);
1006}
1007
1008void __init smp_prepare_cpus(unsigned int max_cpus)
1009{
1010 /* request the 0x1201 emergency signal external interrupt */
1011 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
1012 panic("Couldn't request external interrupt 0x1201");
1013 /* request the 0x1202 external call external interrupt */
1014 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
1015 panic("Couldn't request external interrupt 0x1202");
1016}
1017
1018void __init smp_prepare_boot_cpu(void)
1019{
1020 struct pcpu *pcpu = pcpu_devices;
1021
1022 WARN_ON(!cpu_present(0) || !cpu_online(0));
1023 pcpu->state = CPU_STATE_CONFIGURED;
1024 S390_lowcore.percpu_offset = __per_cpu_offset[0];
1025 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
1026}
1027
1028void __init smp_setup_processor_id(void)
1029{
1030 pcpu_devices[0].address = stap();
1031 S390_lowcore.cpu_nr = 0;
1032 S390_lowcore.spinlock_lockval = arch_spin_lockval(0);
1033 S390_lowcore.spinlock_index = 0;
1034}
1035
1036/*
1037 * the frequency of the profiling timer can be changed
1038 * by writing a multiplier value into /proc/profile.
1039 *
1040 * usually you want to run this on all CPUs ;)
1041 */
1042int setup_profiling_timer(unsigned int multiplier)
1043{
1044 return 0;
1045}
1046
1047static ssize_t cpu_configure_show(struct device *dev,
1048 struct device_attribute *attr, char *buf)
1049{
1050 ssize_t count;
1051
1052 mutex_lock(&smp_cpu_state_mutex);
1053 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
1054 mutex_unlock(&smp_cpu_state_mutex);
1055 return count;
1056}
1057
1058static ssize_t cpu_configure_store(struct device *dev,
1059 struct device_attribute *attr,
1060 const char *buf, size_t count)
1061{
1062 struct pcpu *pcpu;
1063 int cpu, val, rc, i;
1064 char delim;
1065
1066 if (sscanf(buf, "%d %c", &val, &delim) != 1)
1067 return -EINVAL;
1068 if (val != 0 && val != 1)
1069 return -EINVAL;
1070 cpus_read_lock();
1071 mutex_lock(&smp_cpu_state_mutex);
1072 rc = -EBUSY;
1073 /* disallow configuration changes of online cpus and cpu 0 */
1074 cpu = dev->id;
1075 cpu = smp_get_base_cpu(cpu);
1076 if (cpu == 0)
1077 goto out;
1078 for (i = 0; i <= smp_cpu_mtid; i++)
1079 if (cpu_online(cpu + i))
1080 goto out;
1081 pcpu = pcpu_devices + cpu;
1082 rc = 0;
1083 switch (val) {
1084 case 0:
1085 if (pcpu->state != CPU_STATE_CONFIGURED)
1086 break;
1087 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift);
1088 if (rc)
1089 break;
1090 for (i = 0; i <= smp_cpu_mtid; i++) {
1091 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1092 continue;
1093 pcpu[i].state = CPU_STATE_STANDBY;
1094 smp_cpu_set_polarization(cpu + i,
1095 POLARIZATION_UNKNOWN);
1096 }
1097 topology_expect_change();
1098 break;
1099 case 1:
1100 if (pcpu->state != CPU_STATE_STANDBY)
1101 break;
1102 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift);
1103 if (rc)
1104 break;
1105 for (i = 0; i <= smp_cpu_mtid; i++) {
1106 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1107 continue;
1108 pcpu[i].state = CPU_STATE_CONFIGURED;
1109 smp_cpu_set_polarization(cpu + i,
1110 POLARIZATION_UNKNOWN);
1111 }
1112 topology_expect_change();
1113 break;
1114 default:
1115 break;
1116 }
1117out:
1118 mutex_unlock(&smp_cpu_state_mutex);
1119 cpus_read_unlock();
1120 return rc ? rc : count;
1121}
1122static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
1123
1124static ssize_t show_cpu_address(struct device *dev,
1125 struct device_attribute *attr, char *buf)
1126{
1127 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
1128}
1129static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
1130
1131static struct attribute *cpu_common_attrs[] = {
1132 &dev_attr_configure.attr,
1133 &dev_attr_address.attr,
1134 NULL,
1135};
1136
1137static struct attribute_group cpu_common_attr_group = {
1138 .attrs = cpu_common_attrs,
1139};
1140
1141static struct attribute *cpu_online_attrs[] = {
1142 &dev_attr_idle_count.attr,
1143 &dev_attr_idle_time_us.attr,
1144 NULL,
1145};
1146
1147static struct attribute_group cpu_online_attr_group = {
1148 .attrs = cpu_online_attrs,
1149};
1150
1151static int smp_cpu_online(unsigned int cpu)
1152{
1153 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1154
1155 return sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1156}
1157
1158static int smp_cpu_pre_down(unsigned int cpu)
1159{
1160 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1161
1162 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1163 return 0;
1164}
1165
1166static int smp_add_present_cpu(int cpu)
1167{
1168 struct device *s;
1169 struct cpu *c;
1170 int rc;
1171
1172 c = kzalloc(sizeof(*c), GFP_KERNEL);
1173 if (!c)
1174 return -ENOMEM;
1175 per_cpu(cpu_device, cpu) = c;
1176 s = &c->dev;
1177 c->hotpluggable = 1;
1178 rc = register_cpu(c, cpu);
1179 if (rc)
1180 goto out;
1181 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1182 if (rc)
1183 goto out_cpu;
1184 rc = topology_cpu_init(c);
1185 if (rc)
1186 goto out_topology;
1187 return 0;
1188
1189out_topology:
1190 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1191out_cpu:
1192 unregister_cpu(c);
1193out:
1194 return rc;
1195}
1196
1197int __ref smp_rescan_cpus(void)
1198{
1199 struct sclp_core_info *info;
1200 int nr;
1201
1202 info = kzalloc(sizeof(*info), GFP_KERNEL);
1203 if (!info)
1204 return -ENOMEM;
1205 smp_get_core_info(info, 0);
1206 nr = __smp_rescan_cpus(info, false);
1207 kfree(info);
1208 if (nr)
1209 topology_schedule_update();
1210 return 0;
1211}
1212
1213static ssize_t __ref rescan_store(struct device *dev,
1214 struct device_attribute *attr,
1215 const char *buf,
1216 size_t count)
1217{
1218 int rc;
1219
1220 rc = lock_device_hotplug_sysfs();
1221 if (rc)
1222 return rc;
1223 rc = smp_rescan_cpus();
1224 unlock_device_hotplug();
1225 return rc ? rc : count;
1226}
1227static DEVICE_ATTR_WO(rescan);
1228
1229static int __init s390_smp_init(void)
1230{
1231 int cpu, rc = 0;
1232
1233 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1234 if (rc)
1235 return rc;
1236 for_each_present_cpu(cpu) {
1237 rc = smp_add_present_cpu(cpu);
1238 if (rc)
1239 goto out;
1240 }
1241
1242 rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "s390/smp:online",
1243 smp_cpu_online, smp_cpu_pre_down);
1244 rc = rc <= 0 ? rc : 0;
1245out:
1246 return rc;
1247}
1248subsys_initcall(s390_smp_init);
1249
1250static __always_inline void set_new_lowcore(struct lowcore *lc)
1251{
1252 union register_pair dst, src;
1253 u32 pfx;
1254
1255 src.even = (unsigned long) &S390_lowcore;
1256 src.odd = sizeof(S390_lowcore);
1257 dst.even = (unsigned long) lc;
1258 dst.odd = sizeof(*lc);
1259 pfx = __pa(lc);
1260
1261 asm volatile(
1262 " mvcl %[dst],%[src]\n"
1263 " spx %[pfx]\n"
1264 : [dst] "+&d" (dst.pair), [src] "+&d" (src.pair)
1265 : [pfx] "Q" (pfx)
1266 : "memory", "cc");
1267}
1268
1269int __init smp_reinit_ipl_cpu(void)
1270{
1271 unsigned long async_stack, nodat_stack, mcck_stack;
1272 struct lowcore *lc, *lc_ipl;
1273 unsigned long flags, cr0;
1274 u64 mcesad;
1275
1276 lc_ipl = lowcore_ptr[0];
1277 lc = (struct lowcore *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
1278 nodat_stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
1279 async_stack = stack_alloc();
1280 mcck_stack = stack_alloc();
1281 if (!lc || !nodat_stack || !async_stack || !mcck_stack || nmi_alloc_mcesa(&mcesad))
1282 panic("Couldn't allocate memory");
1283
1284 local_irq_save(flags);
1285 local_mcck_disable();
1286 set_new_lowcore(lc);
1287 S390_lowcore.nodat_stack = nodat_stack + STACK_INIT_OFFSET;
1288 S390_lowcore.async_stack = async_stack + STACK_INIT_OFFSET;
1289 S390_lowcore.mcck_stack = mcck_stack + STACK_INIT_OFFSET;
1290 __ctl_store(cr0, 0, 0);
1291 __ctl_clear_bit(0, 28); /* disable lowcore protection */
1292 S390_lowcore.mcesad = mcesad;
1293 __ctl_load(cr0, 0, 0);
1294 if (abs_lowcore_map(0, lc, false))
1295 panic("Couldn't remap absolute lowcore");
1296 lowcore_ptr[0] = lc;
1297 local_mcck_enable();
1298 local_irq_restore(flags);
1299
1300 free_pages(lc_ipl->async_stack - STACK_INIT_OFFSET, THREAD_SIZE_ORDER);
1301 memblock_free_late(__pa(lc_ipl->mcck_stack - STACK_INIT_OFFSET), THREAD_SIZE);
1302 memblock_free_late(__pa(lc_ipl), sizeof(*lc_ipl));
1303
1304 return 0;
1305}
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);