Loading...
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 * Heiko Carstens <heiko.carstens@de.ibm.com>,
9 *
10 * based on other smp stuff by
11 * (c) 1995 Alan Cox, CymruNET Ltd <alan@cymru.net>
12 * (c) 1998 Ingo Molnar
13 *
14 * The code outside of smp.c uses logical cpu numbers, only smp.c does
15 * the translation of logical to physical cpu ids. All new code that
16 * operates on physical cpu numbers needs to go into smp.c.
17 */
18
19#define KMSG_COMPONENT "cpu"
20#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
21
22#include <linux/workqueue.h>
23#include <linux/memblock.h>
24#include <linux/export.h>
25#include <linux/init.h>
26#include <linux/mm.h>
27#include <linux/err.h>
28#include <linux/spinlock.h>
29#include <linux/kernel_stat.h>
30#include <linux/delay.h>
31#include <linux/interrupt.h>
32#include <linux/irqflags.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/lowcore.h>
49#include <asm/sclp.h>
50#include <asm/vdso.h>
51#include <asm/debug.h>
52#include <asm/os_info.h>
53#include <asm/sigp.h>
54#include <asm/idle.h>
55#include <asm/nmi.h>
56#include <asm/stacktrace.h>
57#include <asm/topology.h>
58#include "entry.h"
59
60enum {
61 ec_schedule = 0,
62 ec_call_function_single,
63 ec_stop_cpu,
64};
65
66enum {
67 CPU_STATE_STANDBY,
68 CPU_STATE_CONFIGURED,
69};
70
71static DEFINE_PER_CPU(struct cpu *, cpu_device);
72
73struct pcpu {
74 struct lowcore *lowcore; /* lowcore page(s) for the cpu */
75 unsigned long ec_mask; /* bit mask for ec_xxx functions */
76 unsigned long ec_clk; /* sigp timestamp for ec_xxx */
77 signed char state; /* physical cpu state */
78 signed char polarization; /* physical polarization */
79 u16 address; /* physical cpu address */
80};
81
82static u8 boot_core_type;
83static struct pcpu pcpu_devices[NR_CPUS];
84
85unsigned int smp_cpu_mt_shift;
86EXPORT_SYMBOL(smp_cpu_mt_shift);
87
88unsigned int smp_cpu_mtid;
89EXPORT_SYMBOL(smp_cpu_mtid);
90
91#ifdef CONFIG_CRASH_DUMP
92__vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
93#endif
94
95static unsigned int smp_max_threads __initdata = -1U;
96
97static int __init early_nosmt(char *s)
98{
99 smp_max_threads = 1;
100 return 0;
101}
102early_param("nosmt", early_nosmt);
103
104static int __init early_smt(char *s)
105{
106 get_option(&s, &smp_max_threads);
107 return 0;
108}
109early_param("smt", early_smt);
110
111/*
112 * The smp_cpu_state_mutex must be held when changing the state or polarization
113 * member of a pcpu data structure within the pcpu_devices arreay.
114 */
115DEFINE_MUTEX(smp_cpu_state_mutex);
116
117/*
118 * Signal processor helper functions.
119 */
120static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm)
121{
122 int cc;
123
124 while (1) {
125 cc = __pcpu_sigp(addr, order, parm, NULL);
126 if (cc != SIGP_CC_BUSY)
127 return cc;
128 cpu_relax();
129 }
130}
131
132static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
133{
134 int cc, retry;
135
136 for (retry = 0; ; retry++) {
137 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
138 if (cc != SIGP_CC_BUSY)
139 break;
140 if (retry >= 3)
141 udelay(10);
142 }
143 return cc;
144}
145
146static inline int pcpu_stopped(struct pcpu *pcpu)
147{
148 u32 uninitialized_var(status);
149
150 if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
151 0, &status) != SIGP_CC_STATUS_STORED)
152 return 0;
153 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
154}
155
156static inline int pcpu_running(struct pcpu *pcpu)
157{
158 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
159 0, NULL) != SIGP_CC_STATUS_STORED)
160 return 1;
161 /* Status stored condition code is equivalent to cpu not running. */
162 return 0;
163}
164
165/*
166 * Find struct pcpu by cpu address.
167 */
168static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address)
169{
170 int cpu;
171
172 for_each_cpu(cpu, mask)
173 if (pcpu_devices[cpu].address == address)
174 return pcpu_devices + cpu;
175 return NULL;
176}
177
178static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
179{
180 int order;
181
182 if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
183 return;
184 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
185 pcpu->ec_clk = get_tod_clock_fast();
186 pcpu_sigp_retry(pcpu, order, 0);
187}
188
189static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
190{
191 unsigned long async_stack, nodat_stack;
192 struct lowcore *lc;
193
194 if (pcpu != &pcpu_devices[0]) {
195 pcpu->lowcore = (struct lowcore *)
196 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
197 nodat_stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
198 if (!pcpu->lowcore || !nodat_stack)
199 goto out;
200 } else {
201 nodat_stack = pcpu->lowcore->nodat_stack - STACK_INIT_OFFSET;
202 }
203 async_stack = stack_alloc();
204 if (!async_stack)
205 goto out;
206 lc = pcpu->lowcore;
207 memcpy(lc, &S390_lowcore, 512);
208 memset((char *) lc + 512, 0, sizeof(*lc) - 512);
209 lc->async_stack = async_stack + STACK_INIT_OFFSET;
210 lc->nodat_stack = nodat_stack + STACK_INIT_OFFSET;
211 lc->cpu_nr = cpu;
212 lc->spinlock_lockval = arch_spin_lockval(cpu);
213 lc->spinlock_index = 0;
214 lc->br_r1_trampoline = 0x07f1; /* br %r1 */
215 if (nmi_alloc_per_cpu(lc))
216 goto out_async;
217 if (vdso_alloc_per_cpu(lc))
218 goto out_mcesa;
219 lowcore_ptr[cpu] = lc;
220 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
221 return 0;
222
223out_mcesa:
224 nmi_free_per_cpu(lc);
225out_async:
226 stack_free(async_stack);
227out:
228 if (pcpu != &pcpu_devices[0]) {
229 free_pages(nodat_stack, THREAD_SIZE_ORDER);
230 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
231 }
232 return -ENOMEM;
233}
234
235static void pcpu_free_lowcore(struct pcpu *pcpu)
236{
237 unsigned long async_stack, nodat_stack, lowcore;
238
239 nodat_stack = pcpu->lowcore->nodat_stack - STACK_INIT_OFFSET;
240 async_stack = pcpu->lowcore->async_stack - STACK_INIT_OFFSET;
241 lowcore = (unsigned long) pcpu->lowcore;
242
243 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
244 lowcore_ptr[pcpu - pcpu_devices] = NULL;
245 vdso_free_per_cpu(pcpu->lowcore);
246 nmi_free_per_cpu(pcpu->lowcore);
247 stack_free(async_stack);
248 if (pcpu == &pcpu_devices[0])
249 return;
250 free_pages(nodat_stack, THREAD_SIZE_ORDER);
251 free_pages(lowcore, LC_ORDER);
252}
253
254static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
255{
256 struct lowcore *lc = pcpu->lowcore;
257
258 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
259 cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
260 lc->cpu_nr = cpu;
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->machine_flags = S390_lowcore.machine_flags;
266 lc->user_timer = lc->system_timer =
267 lc->steal_timer = lc->avg_steal_timer = 0;
268 __ctl_store(lc->cregs_save_area, 0, 15);
269 save_access_regs((unsigned int *) lc->access_regs_save_area);
270 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
271 sizeof(lc->stfle_fac_list));
272 memcpy(lc->alt_stfle_fac_list, S390_lowcore.alt_stfle_fac_list,
273 sizeof(lc->alt_stfle_fac_list));
274 arch_spin_lock_setup(cpu);
275}
276
277static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
278{
279 struct lowcore *lc = pcpu->lowcore;
280
281 lc->kernel_stack = (unsigned long) task_stack_page(tsk)
282 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
283 lc->current_task = (unsigned long) tsk;
284 lc->lpp = LPP_MAGIC;
285 lc->current_pid = tsk->pid;
286 lc->user_timer = tsk->thread.user_timer;
287 lc->guest_timer = tsk->thread.guest_timer;
288 lc->system_timer = tsk->thread.system_timer;
289 lc->hardirq_timer = tsk->thread.hardirq_timer;
290 lc->softirq_timer = tsk->thread.softirq_timer;
291 lc->steal_timer = 0;
292}
293
294static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
295{
296 struct lowcore *lc = pcpu->lowcore;
297
298 lc->restart_stack = lc->nodat_stack;
299 lc->restart_fn = (unsigned long) func;
300 lc->restart_data = (unsigned long) data;
301 lc->restart_source = -1UL;
302 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
303}
304
305/*
306 * Call function via PSW restart on pcpu and stop the current cpu.
307 */
308static void __pcpu_delegate(void (*func)(void*), void *data)
309{
310 func(data); /* should not return */
311}
312
313static void __no_sanitize_address pcpu_delegate(struct pcpu *pcpu,
314 void (*func)(void *),
315 void *data, unsigned long stack)
316{
317 struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
318 unsigned long source_cpu = stap();
319
320 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
321 if (pcpu->address == source_cpu)
322 CALL_ON_STACK(__pcpu_delegate, stack, 2, func, data);
323 /* Stop target cpu (if func returns this stops the current cpu). */
324 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
325 /* Restart func on the target cpu and stop the current cpu. */
326 mem_assign_absolute(lc->restart_stack, stack);
327 mem_assign_absolute(lc->restart_fn, (unsigned long) func);
328 mem_assign_absolute(lc->restart_data, (unsigned long) data);
329 mem_assign_absolute(lc->restart_source, source_cpu);
330 __bpon();
331 asm volatile(
332 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
333 " brc 2,0b # busy, try again\n"
334 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
335 " brc 2,1b # busy, try again\n"
336 : : "d" (pcpu->address), "d" (source_cpu),
337 "K" (SIGP_RESTART), "K" (SIGP_STOP)
338 : "0", "1", "cc");
339 for (;;) ;
340}
341
342/*
343 * Enable additional logical cpus for multi-threading.
344 */
345static int pcpu_set_smt(unsigned int mtid)
346{
347 int cc;
348
349 if (smp_cpu_mtid == mtid)
350 return 0;
351 cc = __pcpu_sigp(0, SIGP_SET_MULTI_THREADING, mtid, NULL);
352 if (cc == 0) {
353 smp_cpu_mtid = mtid;
354 smp_cpu_mt_shift = 0;
355 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift))
356 smp_cpu_mt_shift++;
357 pcpu_devices[0].address = stap();
358 }
359 return cc;
360}
361
362/*
363 * Call function on an online CPU.
364 */
365void smp_call_online_cpu(void (*func)(void *), void *data)
366{
367 struct pcpu *pcpu;
368
369 /* Use the current cpu if it is online. */
370 pcpu = pcpu_find_address(cpu_online_mask, stap());
371 if (!pcpu)
372 /* Use the first online cpu. */
373 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
374 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
375}
376
377/*
378 * Call function on the ipl CPU.
379 */
380void smp_call_ipl_cpu(void (*func)(void *), void *data)
381{
382 struct lowcore *lc = pcpu_devices->lowcore;
383
384 if (pcpu_devices[0].address == stap())
385 lc = &S390_lowcore;
386
387 pcpu_delegate(&pcpu_devices[0], func, data,
388 lc->nodat_stack);
389}
390
391int smp_find_processor_id(u16 address)
392{
393 int cpu;
394
395 for_each_present_cpu(cpu)
396 if (pcpu_devices[cpu].address == address)
397 return cpu;
398 return -1;
399}
400
401bool arch_vcpu_is_preempted(int cpu)
402{
403 if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu))
404 return false;
405 if (pcpu_running(pcpu_devices + cpu))
406 return false;
407 return true;
408}
409EXPORT_SYMBOL(arch_vcpu_is_preempted);
410
411void smp_yield_cpu(int cpu)
412{
413 if (MACHINE_HAS_DIAG9C) {
414 diag_stat_inc_norecursion(DIAG_STAT_X09C);
415 asm volatile("diag %0,0,0x9c"
416 : : "d" (pcpu_devices[cpu].address));
417 } else if (MACHINE_HAS_DIAG44 && !smp_cpu_mtid) {
418 diag_stat_inc_norecursion(DIAG_STAT_X044);
419 asm volatile("diag 0,0,0x44");
420 }
421}
422
423/*
424 * Send cpus emergency shutdown signal. This gives the cpus the
425 * opportunity to complete outstanding interrupts.
426 */
427void notrace smp_emergency_stop(void)
428{
429 cpumask_t cpumask;
430 u64 end;
431 int cpu;
432
433 cpumask_copy(&cpumask, cpu_online_mask);
434 cpumask_clear_cpu(smp_processor_id(), &cpumask);
435
436 end = get_tod_clock() + (1000000UL << 12);
437 for_each_cpu(cpu, &cpumask) {
438 struct pcpu *pcpu = pcpu_devices + cpu;
439 set_bit(ec_stop_cpu, &pcpu->ec_mask);
440 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
441 0, NULL) == SIGP_CC_BUSY &&
442 get_tod_clock() < end)
443 cpu_relax();
444 }
445 while (get_tod_clock() < end) {
446 for_each_cpu(cpu, &cpumask)
447 if (pcpu_stopped(pcpu_devices + cpu))
448 cpumask_clear_cpu(cpu, &cpumask);
449 if (cpumask_empty(&cpumask))
450 break;
451 cpu_relax();
452 }
453}
454NOKPROBE_SYMBOL(smp_emergency_stop);
455
456/*
457 * Stop all cpus but the current one.
458 */
459void smp_send_stop(void)
460{
461 int cpu;
462
463 /* Disable all interrupts/machine checks */
464 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
465 trace_hardirqs_off();
466
467 debug_set_critical();
468
469 if (oops_in_progress)
470 smp_emergency_stop();
471
472 /* stop all processors */
473 for_each_online_cpu(cpu) {
474 if (cpu == smp_processor_id())
475 continue;
476 pcpu_sigp_retry(pcpu_devices + cpu, SIGP_STOP, 0);
477 while (!pcpu_stopped(pcpu_devices + cpu))
478 cpu_relax();
479 }
480}
481
482/*
483 * This is the main routine where commands issued by other
484 * cpus are handled.
485 */
486static void smp_handle_ext_call(void)
487{
488 unsigned long bits;
489
490 /* handle bit signal external calls */
491 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
492 if (test_bit(ec_stop_cpu, &bits))
493 smp_stop_cpu();
494 if (test_bit(ec_schedule, &bits))
495 scheduler_ipi();
496 if (test_bit(ec_call_function_single, &bits))
497 generic_smp_call_function_single_interrupt();
498}
499
500static void do_ext_call_interrupt(struct ext_code ext_code,
501 unsigned int param32, unsigned long param64)
502{
503 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
504 smp_handle_ext_call();
505}
506
507void arch_send_call_function_ipi_mask(const struct cpumask *mask)
508{
509 int cpu;
510
511 for_each_cpu(cpu, mask)
512 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
513}
514
515void arch_send_call_function_single_ipi(int cpu)
516{
517 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
518}
519
520/*
521 * this function sends a 'reschedule' IPI to another CPU.
522 * it goes straight through and wastes no time serializing
523 * anything. Worst case is that we lose a reschedule ...
524 */
525void smp_send_reschedule(int cpu)
526{
527 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
528}
529
530/*
531 * parameter area for the set/clear control bit callbacks
532 */
533struct ec_creg_mask_parms {
534 unsigned long orval;
535 unsigned long andval;
536 int cr;
537};
538
539/*
540 * callback for setting/clearing control bits
541 */
542static void smp_ctl_bit_callback(void *info)
543{
544 struct ec_creg_mask_parms *pp = info;
545 unsigned long cregs[16];
546
547 __ctl_store(cregs, 0, 15);
548 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
549 __ctl_load(cregs, 0, 15);
550}
551
552/*
553 * Set a bit in a control register of all cpus
554 */
555void smp_ctl_set_bit(int cr, int bit)
556{
557 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
558
559 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
560}
561EXPORT_SYMBOL(smp_ctl_set_bit);
562
563/*
564 * Clear a bit in a control register of all cpus
565 */
566void smp_ctl_clear_bit(int cr, int bit)
567{
568 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
569
570 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
571}
572EXPORT_SYMBOL(smp_ctl_clear_bit);
573
574#ifdef CONFIG_CRASH_DUMP
575
576int smp_store_status(int cpu)
577{
578 struct pcpu *pcpu = pcpu_devices + cpu;
579 unsigned long pa;
580
581 pa = __pa(&pcpu->lowcore->floating_pt_save_area);
582 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS,
583 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
584 return -EIO;
585 if (!MACHINE_HAS_VX && !MACHINE_HAS_GS)
586 return 0;
587 pa = __pa(pcpu->lowcore->mcesad & MCESA_ORIGIN_MASK);
588 if (MACHINE_HAS_GS)
589 pa |= pcpu->lowcore->mcesad & MCESA_LC_MASK;
590 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
591 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
592 return -EIO;
593 return 0;
594}
595
596/*
597 * Collect CPU state of the previous, crashed system.
598 * There are four cases:
599 * 1) standard zfcp dump
600 * condition: OLDMEM_BASE == NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
601 * The state for all CPUs except the boot CPU needs to be collected
602 * with sigp stop-and-store-status. The boot CPU state is located in
603 * the absolute lowcore of the memory stored in the HSA. The zcore code
604 * will copy the boot CPU state from the HSA.
605 * 2) stand-alone kdump for SCSI (zfcp dump with swapped memory)
606 * condition: OLDMEM_BASE != NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
607 * The state for all CPUs except the boot CPU needs to be collected
608 * with sigp stop-and-store-status. The firmware or the boot-loader
609 * stored the registers of the boot CPU in the absolute lowcore in the
610 * memory of the old system.
611 * 3) kdump and the old kernel did not store the CPU state,
612 * or stand-alone kdump for DASD
613 * condition: OLDMEM_BASE != NULL && !is_kdump_kernel()
614 * The state for all CPUs except the boot CPU needs to be collected
615 * with sigp stop-and-store-status. The kexec code or the boot-loader
616 * stored the registers of the boot CPU in the memory of the old system.
617 * 4) kdump and the old kernel stored the CPU state
618 * condition: OLDMEM_BASE != NULL && is_kdump_kernel()
619 * This case does not exist for s390 anymore, setup_arch explicitly
620 * deactivates the elfcorehdr= kernel parameter
621 */
622static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr,
623 bool is_boot_cpu, unsigned long page)
624{
625 __vector128 *vxrs = (__vector128 *) page;
626
627 if (is_boot_cpu)
628 vxrs = boot_cpu_vector_save_area;
629 else
630 __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page);
631 save_area_add_vxrs(sa, vxrs);
632}
633
634static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr,
635 bool is_boot_cpu, unsigned long page)
636{
637 void *regs = (void *) page;
638
639 if (is_boot_cpu)
640 copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512);
641 else
642 __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page);
643 save_area_add_regs(sa, regs);
644}
645
646void __init smp_save_dump_cpus(void)
647{
648 int addr, boot_cpu_addr, max_cpu_addr;
649 struct save_area *sa;
650 unsigned long page;
651 bool is_boot_cpu;
652
653 if (!(OLDMEM_BASE || ipl_info.type == IPL_TYPE_FCP_DUMP))
654 /* No previous system present, normal boot. */
655 return;
656 /* Allocate a page as dumping area for the store status sigps */
657 page = memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE, 0, 1UL << 31);
658 if (!page)
659 panic("ERROR: Failed to allocate %lx bytes below %lx\n",
660 PAGE_SIZE, 1UL << 31);
661
662 /* Set multi-threading state to the previous system. */
663 pcpu_set_smt(sclp.mtid_prev);
664 boot_cpu_addr = stap();
665 max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;
666 for (addr = 0; addr <= max_cpu_addr; addr++) {
667 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==
668 SIGP_CC_NOT_OPERATIONAL)
669 continue;
670 is_boot_cpu = (addr == boot_cpu_addr);
671 /* Allocate save area */
672 sa = save_area_alloc(is_boot_cpu);
673 if (!sa)
674 panic("could not allocate memory for save area\n");
675 if (MACHINE_HAS_VX)
676 /* Get the vector registers */
677 smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page);
678 /*
679 * For a zfcp dump OLDMEM_BASE == NULL and the registers
680 * of the boot CPU are stored in the HSA. To retrieve
681 * these registers an SCLP request is required which is
682 * done by drivers/s390/char/zcore.c:init_cpu_info()
683 */
684 if (!is_boot_cpu || OLDMEM_BASE)
685 /* Get the CPU registers */
686 smp_save_cpu_regs(sa, addr, is_boot_cpu, page);
687 }
688 memblock_free(page, PAGE_SIZE);
689 diag_dma_ops.diag308_reset();
690 pcpu_set_smt(0);
691}
692#endif /* CONFIG_CRASH_DUMP */
693
694void smp_cpu_set_polarization(int cpu, int val)
695{
696 pcpu_devices[cpu].polarization = val;
697}
698
699int smp_cpu_get_polarization(int cpu)
700{
701 return pcpu_devices[cpu].polarization;
702}
703
704static void __ref smp_get_core_info(struct sclp_core_info *info, int early)
705{
706 static int use_sigp_detection;
707 int address;
708
709 if (use_sigp_detection || sclp_get_core_info(info, early)) {
710 use_sigp_detection = 1;
711 for (address = 0;
712 address < (SCLP_MAX_CORES << smp_cpu_mt_shift);
713 address += (1U << smp_cpu_mt_shift)) {
714 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) ==
715 SIGP_CC_NOT_OPERATIONAL)
716 continue;
717 info->core[info->configured].core_id =
718 address >> smp_cpu_mt_shift;
719 info->configured++;
720 }
721 info->combined = info->configured;
722 }
723}
724
725static int smp_add_present_cpu(int cpu);
726
727static int __smp_rescan_cpus(struct sclp_core_info *info, int sysfs_add)
728{
729 struct pcpu *pcpu;
730 cpumask_t avail;
731 int cpu, nr, i, j;
732 u16 address;
733
734 nr = 0;
735 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
736 cpu = cpumask_first(&avail);
737 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) {
738 if (sclp.has_core_type && info->core[i].type != boot_core_type)
739 continue;
740 address = info->core[i].core_id << smp_cpu_mt_shift;
741 for (j = 0; j <= smp_cpu_mtid; j++) {
742 if (pcpu_find_address(cpu_present_mask, address + j))
743 continue;
744 pcpu = pcpu_devices + cpu;
745 pcpu->address = address + j;
746 pcpu->state =
747 (cpu >= info->configured*(smp_cpu_mtid + 1)) ?
748 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED;
749 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
750 set_cpu_present(cpu, true);
751 if (sysfs_add && smp_add_present_cpu(cpu) != 0)
752 set_cpu_present(cpu, false);
753 else
754 nr++;
755 cpu = cpumask_next(cpu, &avail);
756 if (cpu >= nr_cpu_ids)
757 break;
758 }
759 }
760 return nr;
761}
762
763void __init smp_detect_cpus(void)
764{
765 unsigned int cpu, mtid, c_cpus, s_cpus;
766 struct sclp_core_info *info;
767 u16 address;
768
769 /* Get CPU information */
770 info = memblock_alloc(sizeof(*info), 8);
771 if (!info)
772 panic("%s: Failed to allocate %zu bytes align=0x%x\n",
773 __func__, sizeof(*info), 8);
774 smp_get_core_info(info, 1);
775 /* Find boot CPU type */
776 if (sclp.has_core_type) {
777 address = stap();
778 for (cpu = 0; cpu < info->combined; cpu++)
779 if (info->core[cpu].core_id == address) {
780 /* The boot cpu dictates the cpu type. */
781 boot_core_type = info->core[cpu].type;
782 break;
783 }
784 if (cpu >= info->combined)
785 panic("Could not find boot CPU type");
786 }
787
788 /* Set multi-threading state for the current system */
789 mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp;
790 mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1;
791 pcpu_set_smt(mtid);
792
793 /* Print number of CPUs */
794 c_cpus = s_cpus = 0;
795 for (cpu = 0; cpu < info->combined; cpu++) {
796 if (sclp.has_core_type &&
797 info->core[cpu].type != boot_core_type)
798 continue;
799 if (cpu < info->configured)
800 c_cpus += smp_cpu_mtid + 1;
801 else
802 s_cpus += smp_cpu_mtid + 1;
803 }
804 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
805
806 /* Add CPUs present at boot */
807 get_online_cpus();
808 __smp_rescan_cpus(info, 0);
809 put_online_cpus();
810 memblock_free_early((unsigned long)info, sizeof(*info));
811}
812
813static void smp_init_secondary(void)
814{
815 int cpu = smp_processor_id();
816
817 S390_lowcore.last_update_clock = get_tod_clock();
818 restore_access_regs(S390_lowcore.access_regs_save_area);
819 cpu_init();
820 preempt_disable();
821 init_cpu_timer();
822 vtime_init();
823 pfault_init();
824 notify_cpu_starting(smp_processor_id());
825 if (topology_cpu_dedicated(cpu))
826 set_cpu_flag(CIF_DEDICATED_CPU);
827 else
828 clear_cpu_flag(CIF_DEDICATED_CPU);
829 set_cpu_online(smp_processor_id(), true);
830 inc_irq_stat(CPU_RST);
831 local_irq_enable();
832 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
833}
834
835/*
836 * Activate a secondary processor.
837 */
838static void __no_sanitize_address smp_start_secondary(void *cpuvoid)
839{
840 S390_lowcore.restart_stack = (unsigned long) restart_stack;
841 S390_lowcore.restart_fn = (unsigned long) do_restart;
842 S390_lowcore.restart_data = 0;
843 S390_lowcore.restart_source = -1UL;
844 __ctl_load(S390_lowcore.cregs_save_area, 0, 15);
845 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
846 CALL_ON_STACK(smp_init_secondary, S390_lowcore.kernel_stack, 0);
847}
848
849/* Upping and downing of CPUs */
850int __cpu_up(unsigned int cpu, struct task_struct *tidle)
851{
852 struct pcpu *pcpu;
853 int base, i, rc;
854
855 pcpu = pcpu_devices + cpu;
856 if (pcpu->state != CPU_STATE_CONFIGURED)
857 return -EIO;
858 base = smp_get_base_cpu(cpu);
859 for (i = 0; i <= smp_cpu_mtid; i++) {
860 if (base + i < nr_cpu_ids)
861 if (cpu_online(base + i))
862 break;
863 }
864 /*
865 * If this is the first CPU of the core to get online
866 * do an initial CPU reset.
867 */
868 if (i > smp_cpu_mtid &&
869 pcpu_sigp_retry(pcpu_devices + base, SIGP_INITIAL_CPU_RESET, 0) !=
870 SIGP_CC_ORDER_CODE_ACCEPTED)
871 return -EIO;
872
873 rc = pcpu_alloc_lowcore(pcpu, cpu);
874 if (rc)
875 return rc;
876 pcpu_prepare_secondary(pcpu, cpu);
877 pcpu_attach_task(pcpu, tidle);
878 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
879 /* Wait until cpu puts itself in the online & active maps */
880 while (!cpu_online(cpu))
881 cpu_relax();
882 return 0;
883}
884
885static unsigned int setup_possible_cpus __initdata;
886
887static int __init _setup_possible_cpus(char *s)
888{
889 get_option(&s, &setup_possible_cpus);
890 return 0;
891}
892early_param("possible_cpus", _setup_possible_cpus);
893
894int __cpu_disable(void)
895{
896 unsigned long cregs[16];
897
898 /* Handle possible pending IPIs */
899 smp_handle_ext_call();
900 set_cpu_online(smp_processor_id(), false);
901 /* Disable pseudo page faults on this cpu. */
902 pfault_fini();
903 /* Disable interrupt sources via control register. */
904 __ctl_store(cregs, 0, 15);
905 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
906 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
907 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
908 __ctl_load(cregs, 0, 15);
909 clear_cpu_flag(CIF_NOHZ_DELAY);
910 return 0;
911}
912
913void __cpu_die(unsigned int cpu)
914{
915 struct pcpu *pcpu;
916
917 /* Wait until target cpu is down */
918 pcpu = pcpu_devices + cpu;
919 while (!pcpu_stopped(pcpu))
920 cpu_relax();
921 pcpu_free_lowcore(pcpu);
922 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
923 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
924}
925
926void __noreturn cpu_die(void)
927{
928 idle_task_exit();
929 __bpon();
930 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
931 for (;;) ;
932}
933
934void __init smp_fill_possible_mask(void)
935{
936 unsigned int possible, sclp_max, cpu;
937
938 sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1;
939 sclp_max = min(smp_max_threads, sclp_max);
940 sclp_max = (sclp.max_cores * sclp_max) ?: nr_cpu_ids;
941 possible = setup_possible_cpus ?: nr_cpu_ids;
942 possible = min(possible, sclp_max);
943 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
944 set_cpu_possible(cpu, true);
945}
946
947void __init smp_prepare_cpus(unsigned int max_cpus)
948{
949 /* request the 0x1201 emergency signal external interrupt */
950 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
951 panic("Couldn't request external interrupt 0x1201");
952 /* request the 0x1202 external call external interrupt */
953 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
954 panic("Couldn't request external interrupt 0x1202");
955}
956
957void __init smp_prepare_boot_cpu(void)
958{
959 struct pcpu *pcpu = pcpu_devices;
960
961 WARN_ON(!cpu_present(0) || !cpu_online(0));
962 pcpu->state = CPU_STATE_CONFIGURED;
963 pcpu->lowcore = (struct lowcore *)(unsigned long) store_prefix();
964 S390_lowcore.percpu_offset = __per_cpu_offset[0];
965 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
966}
967
968void __init smp_cpus_done(unsigned int max_cpus)
969{
970}
971
972void __init smp_setup_processor_id(void)
973{
974 pcpu_devices[0].address = stap();
975 S390_lowcore.cpu_nr = 0;
976 S390_lowcore.spinlock_lockval = arch_spin_lockval(0);
977 S390_lowcore.spinlock_index = 0;
978}
979
980/*
981 * the frequency of the profiling timer can be changed
982 * by writing a multiplier value into /proc/profile.
983 *
984 * usually you want to run this on all CPUs ;)
985 */
986int setup_profiling_timer(unsigned int multiplier)
987{
988 return 0;
989}
990
991static ssize_t cpu_configure_show(struct device *dev,
992 struct device_attribute *attr, char *buf)
993{
994 ssize_t count;
995
996 mutex_lock(&smp_cpu_state_mutex);
997 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
998 mutex_unlock(&smp_cpu_state_mutex);
999 return count;
1000}
1001
1002static ssize_t cpu_configure_store(struct device *dev,
1003 struct device_attribute *attr,
1004 const char *buf, size_t count)
1005{
1006 struct pcpu *pcpu;
1007 int cpu, val, rc, i;
1008 char delim;
1009
1010 if (sscanf(buf, "%d %c", &val, &delim) != 1)
1011 return -EINVAL;
1012 if (val != 0 && val != 1)
1013 return -EINVAL;
1014 get_online_cpus();
1015 mutex_lock(&smp_cpu_state_mutex);
1016 rc = -EBUSY;
1017 /* disallow configuration changes of online cpus and cpu 0 */
1018 cpu = dev->id;
1019 cpu = smp_get_base_cpu(cpu);
1020 if (cpu == 0)
1021 goto out;
1022 for (i = 0; i <= smp_cpu_mtid; i++)
1023 if (cpu_online(cpu + i))
1024 goto out;
1025 pcpu = pcpu_devices + cpu;
1026 rc = 0;
1027 switch (val) {
1028 case 0:
1029 if (pcpu->state != CPU_STATE_CONFIGURED)
1030 break;
1031 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift);
1032 if (rc)
1033 break;
1034 for (i = 0; i <= smp_cpu_mtid; i++) {
1035 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1036 continue;
1037 pcpu[i].state = CPU_STATE_STANDBY;
1038 smp_cpu_set_polarization(cpu + i,
1039 POLARIZATION_UNKNOWN);
1040 }
1041 topology_expect_change();
1042 break;
1043 case 1:
1044 if (pcpu->state != CPU_STATE_STANDBY)
1045 break;
1046 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift);
1047 if (rc)
1048 break;
1049 for (i = 0; i <= smp_cpu_mtid; i++) {
1050 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1051 continue;
1052 pcpu[i].state = CPU_STATE_CONFIGURED;
1053 smp_cpu_set_polarization(cpu + i,
1054 POLARIZATION_UNKNOWN);
1055 }
1056 topology_expect_change();
1057 break;
1058 default:
1059 break;
1060 }
1061out:
1062 mutex_unlock(&smp_cpu_state_mutex);
1063 put_online_cpus();
1064 return rc ? rc : count;
1065}
1066static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
1067
1068static ssize_t show_cpu_address(struct device *dev,
1069 struct device_attribute *attr, char *buf)
1070{
1071 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
1072}
1073static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
1074
1075static struct attribute *cpu_common_attrs[] = {
1076 &dev_attr_configure.attr,
1077 &dev_attr_address.attr,
1078 NULL,
1079};
1080
1081static struct attribute_group cpu_common_attr_group = {
1082 .attrs = cpu_common_attrs,
1083};
1084
1085static struct attribute *cpu_online_attrs[] = {
1086 &dev_attr_idle_count.attr,
1087 &dev_attr_idle_time_us.attr,
1088 NULL,
1089};
1090
1091static struct attribute_group cpu_online_attr_group = {
1092 .attrs = cpu_online_attrs,
1093};
1094
1095static int smp_cpu_online(unsigned int cpu)
1096{
1097 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1098
1099 return sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1100}
1101static int smp_cpu_pre_down(unsigned int cpu)
1102{
1103 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1104
1105 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1106 return 0;
1107}
1108
1109static int smp_add_present_cpu(int cpu)
1110{
1111 struct device *s;
1112 struct cpu *c;
1113 int rc;
1114
1115 c = kzalloc(sizeof(*c), GFP_KERNEL);
1116 if (!c)
1117 return -ENOMEM;
1118 per_cpu(cpu_device, cpu) = c;
1119 s = &c->dev;
1120 c->hotpluggable = 1;
1121 rc = register_cpu(c, cpu);
1122 if (rc)
1123 goto out;
1124 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1125 if (rc)
1126 goto out_cpu;
1127 rc = topology_cpu_init(c);
1128 if (rc)
1129 goto out_topology;
1130 return 0;
1131
1132out_topology:
1133 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1134out_cpu:
1135 unregister_cpu(c);
1136out:
1137 return rc;
1138}
1139
1140int __ref smp_rescan_cpus(void)
1141{
1142 struct sclp_core_info *info;
1143 int nr;
1144
1145 info = kzalloc(sizeof(*info), GFP_KERNEL);
1146 if (!info)
1147 return -ENOMEM;
1148 smp_get_core_info(info, 0);
1149 get_online_cpus();
1150 mutex_lock(&smp_cpu_state_mutex);
1151 nr = __smp_rescan_cpus(info, 1);
1152 mutex_unlock(&smp_cpu_state_mutex);
1153 put_online_cpus();
1154 kfree(info);
1155 if (nr)
1156 topology_schedule_update();
1157 return 0;
1158}
1159
1160static ssize_t __ref rescan_store(struct device *dev,
1161 struct device_attribute *attr,
1162 const char *buf,
1163 size_t count)
1164{
1165 int rc;
1166
1167 rc = lock_device_hotplug_sysfs();
1168 if (rc)
1169 return rc;
1170 rc = smp_rescan_cpus();
1171 unlock_device_hotplug();
1172 return rc ? rc : count;
1173}
1174static DEVICE_ATTR_WO(rescan);
1175
1176static int __init s390_smp_init(void)
1177{
1178 int cpu, rc = 0;
1179
1180 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1181 if (rc)
1182 return rc;
1183 for_each_present_cpu(cpu) {
1184 rc = smp_add_present_cpu(cpu);
1185 if (rc)
1186 goto out;
1187 }
1188
1189 rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "s390/smp:online",
1190 smp_cpu_online, smp_cpu_pre_down);
1191 rc = rc <= 0 ? rc : 0;
1192out:
1193 return rc;
1194}
1195subsys_initcall(s390_smp_init);
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 * Heiko Carstens <heiko.carstens@de.ibm.com>,
9 *
10 * based on other smp stuff by
11 * (c) 1995 Alan Cox, CymruNET Ltd <alan@cymru.net>
12 * (c) 1998 Ingo Molnar
13 *
14 * The code outside of smp.c uses logical cpu numbers, only smp.c does
15 * the translation of logical to physical cpu ids. All new code that
16 * operates on physical cpu numbers needs to go into smp.c.
17 */
18
19#define KMSG_COMPONENT "cpu"
20#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
21
22#include <linux/workqueue.h>
23#include <linux/memblock.h>
24#include <linux/export.h>
25#include <linux/init.h>
26#include <linux/mm.h>
27#include <linux/err.h>
28#include <linux/spinlock.h>
29#include <linux/kernel_stat.h>
30#include <linux/delay.h>
31#include <linux/interrupt.h>
32#include <linux/irqflags.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/lowcore.h>
49#include <asm/sclp.h>
50#include <asm/vdso.h>
51#include <asm/debug.h>
52#include <asm/os_info.h>
53#include <asm/sigp.h>
54#include <asm/idle.h>
55#include <asm/nmi.h>
56#include <asm/stacktrace.h>
57#include <asm/topology.h>
58#include "entry.h"
59
60enum {
61 ec_schedule = 0,
62 ec_call_function_single,
63 ec_stop_cpu,
64 ec_mcck_pending,
65};
66
67enum {
68 CPU_STATE_STANDBY,
69 CPU_STATE_CONFIGURED,
70};
71
72static DEFINE_PER_CPU(struct cpu *, cpu_device);
73
74struct pcpu {
75 struct lowcore *lowcore; /* lowcore page(s) for the cpu */
76 unsigned long ec_mask; /* bit mask for ec_xxx functions */
77 unsigned long ec_clk; /* sigp timestamp for ec_xxx */
78 signed char state; /* physical cpu state */
79 signed char polarization; /* physical polarization */
80 u16 address; /* physical cpu address */
81};
82
83static u8 boot_core_type;
84static struct pcpu pcpu_devices[NR_CPUS];
85
86unsigned int smp_cpu_mt_shift;
87EXPORT_SYMBOL(smp_cpu_mt_shift);
88
89unsigned int smp_cpu_mtid;
90EXPORT_SYMBOL(smp_cpu_mtid);
91
92#ifdef CONFIG_CRASH_DUMP
93__vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
94#endif
95
96static unsigned int smp_max_threads __initdata = -1U;
97
98static int __init early_nosmt(char *s)
99{
100 smp_max_threads = 1;
101 return 0;
102}
103early_param("nosmt", early_nosmt);
104
105static int __init early_smt(char *s)
106{
107 get_option(&s, &smp_max_threads);
108 return 0;
109}
110early_param("smt", early_smt);
111
112/*
113 * The smp_cpu_state_mutex must be held when changing the state or polarization
114 * member of a pcpu data structure within the pcpu_devices arreay.
115 */
116DEFINE_MUTEX(smp_cpu_state_mutex);
117
118/*
119 * Signal processor helper functions.
120 */
121static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm)
122{
123 int cc;
124
125 while (1) {
126 cc = __pcpu_sigp(addr, order, parm, NULL);
127 if (cc != SIGP_CC_BUSY)
128 return cc;
129 cpu_relax();
130 }
131}
132
133static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
134{
135 int cc, retry;
136
137 for (retry = 0; ; retry++) {
138 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
139 if (cc != SIGP_CC_BUSY)
140 break;
141 if (retry >= 3)
142 udelay(10);
143 }
144 return cc;
145}
146
147static inline int pcpu_stopped(struct pcpu *pcpu)
148{
149 u32 status;
150
151 if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
152 0, &status) != SIGP_CC_STATUS_STORED)
153 return 0;
154 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
155}
156
157static inline int pcpu_running(struct pcpu *pcpu)
158{
159 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
160 0, NULL) != SIGP_CC_STATUS_STORED)
161 return 1;
162 /* Status stored condition code is equivalent to cpu not running. */
163 return 0;
164}
165
166/*
167 * Find struct pcpu by cpu address.
168 */
169static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address)
170{
171 int cpu;
172
173 for_each_cpu(cpu, mask)
174 if (pcpu_devices[cpu].address == address)
175 return pcpu_devices + cpu;
176 return NULL;
177}
178
179static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
180{
181 int order;
182
183 if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
184 return;
185 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
186 pcpu->ec_clk = get_tod_clock_fast();
187 pcpu_sigp_retry(pcpu, order, 0);
188}
189
190static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
191{
192 unsigned long async_stack, nodat_stack;
193 struct lowcore *lc;
194
195 if (pcpu != &pcpu_devices[0]) {
196 pcpu->lowcore = (struct lowcore *)
197 __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
198 nodat_stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
199 if (!pcpu->lowcore || !nodat_stack)
200 goto out;
201 } else {
202 nodat_stack = pcpu->lowcore->nodat_stack - STACK_INIT_OFFSET;
203 }
204 async_stack = stack_alloc();
205 if (!async_stack)
206 goto out;
207 lc = pcpu->lowcore;
208 memcpy(lc, &S390_lowcore, 512);
209 memset((char *) lc + 512, 0, sizeof(*lc) - 512);
210 lc->async_stack = async_stack + STACK_INIT_OFFSET;
211 lc->nodat_stack = nodat_stack + STACK_INIT_OFFSET;
212 lc->cpu_nr = cpu;
213 lc->spinlock_lockval = arch_spin_lockval(cpu);
214 lc->spinlock_index = 0;
215 lc->br_r1_trampoline = 0x07f1; /* br %r1 */
216 lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
217 lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
218 if (nmi_alloc_per_cpu(lc))
219 goto out_async;
220 if (vdso_alloc_per_cpu(lc))
221 goto out_mcesa;
222 lowcore_ptr[cpu] = lc;
223 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
224 return 0;
225
226out_mcesa:
227 nmi_free_per_cpu(lc);
228out_async:
229 stack_free(async_stack);
230out:
231 if (pcpu != &pcpu_devices[0]) {
232 free_pages(nodat_stack, THREAD_SIZE_ORDER);
233 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
234 }
235 return -ENOMEM;
236}
237
238static void pcpu_free_lowcore(struct pcpu *pcpu)
239{
240 unsigned long async_stack, nodat_stack, lowcore;
241
242 nodat_stack = pcpu->lowcore->nodat_stack - STACK_INIT_OFFSET;
243 async_stack = pcpu->lowcore->async_stack - STACK_INIT_OFFSET;
244 lowcore = (unsigned long) pcpu->lowcore;
245
246 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
247 lowcore_ptr[pcpu - pcpu_devices] = NULL;
248 vdso_free_per_cpu(pcpu->lowcore);
249 nmi_free_per_cpu(pcpu->lowcore);
250 stack_free(async_stack);
251 if (pcpu == &pcpu_devices[0])
252 return;
253 free_pages(nodat_stack, THREAD_SIZE_ORDER);
254 free_pages(lowcore, LC_ORDER);
255}
256
257static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
258{
259 struct lowcore *lc = pcpu->lowcore;
260
261 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
262 cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
263 lc->cpu_nr = cpu;
264 lc->spinlock_lockval = arch_spin_lockval(cpu);
265 lc->spinlock_index = 0;
266 lc->percpu_offset = __per_cpu_offset[cpu];
267 lc->kernel_asce = S390_lowcore.kernel_asce;
268 lc->user_asce = S390_lowcore.kernel_asce;
269 lc->machine_flags = S390_lowcore.machine_flags;
270 lc->user_timer = lc->system_timer =
271 lc->steal_timer = lc->avg_steal_timer = 0;
272 __ctl_store(lc->cregs_save_area, 0, 15);
273 lc->cregs_save_area[1] = lc->kernel_asce;
274 lc->cregs_save_area[7] = lc->vdso_asce;
275 save_access_regs((unsigned int *) lc->access_regs_save_area);
276 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
277 sizeof(lc->stfle_fac_list));
278 memcpy(lc->alt_stfle_fac_list, S390_lowcore.alt_stfle_fac_list,
279 sizeof(lc->alt_stfle_fac_list));
280 arch_spin_lock_setup(cpu);
281}
282
283static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
284{
285 struct lowcore *lc = pcpu->lowcore;
286
287 lc->kernel_stack = (unsigned long) task_stack_page(tsk)
288 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
289 lc->current_task = (unsigned long) tsk;
290 lc->lpp = LPP_MAGIC;
291 lc->current_pid = tsk->pid;
292 lc->user_timer = tsk->thread.user_timer;
293 lc->guest_timer = tsk->thread.guest_timer;
294 lc->system_timer = tsk->thread.system_timer;
295 lc->hardirq_timer = tsk->thread.hardirq_timer;
296 lc->softirq_timer = tsk->thread.softirq_timer;
297 lc->steal_timer = 0;
298}
299
300static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
301{
302 struct lowcore *lc = pcpu->lowcore;
303
304 lc->restart_stack = lc->nodat_stack;
305 lc->restart_fn = (unsigned long) func;
306 lc->restart_data = (unsigned long) data;
307 lc->restart_source = -1UL;
308 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
309}
310
311/*
312 * Call function via PSW restart on pcpu and stop the current cpu.
313 */
314static void __pcpu_delegate(void (*func)(void*), void *data)
315{
316 func(data); /* should not return */
317}
318
319static void __no_sanitize_address pcpu_delegate(struct pcpu *pcpu,
320 void (*func)(void *),
321 void *data, unsigned long stack)
322{
323 struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
324 unsigned long source_cpu = stap();
325
326 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
327 if (pcpu->address == source_cpu)
328 CALL_ON_STACK(__pcpu_delegate, stack, 2, func, data);
329 /* Stop target cpu (if func returns this stops the current cpu). */
330 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
331 /* Restart func on the target cpu and stop the current cpu. */
332 mem_assign_absolute(lc->restart_stack, stack);
333 mem_assign_absolute(lc->restart_fn, (unsigned long) func);
334 mem_assign_absolute(lc->restart_data, (unsigned long) data);
335 mem_assign_absolute(lc->restart_source, source_cpu);
336 __bpon();
337 asm volatile(
338 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
339 " brc 2,0b # busy, try again\n"
340 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
341 " brc 2,1b # busy, try again\n"
342 : : "d" (pcpu->address), "d" (source_cpu),
343 "K" (SIGP_RESTART), "K" (SIGP_STOP)
344 : "0", "1", "cc");
345 for (;;) ;
346}
347
348/*
349 * Enable additional logical cpus for multi-threading.
350 */
351static int pcpu_set_smt(unsigned int mtid)
352{
353 int cc;
354
355 if (smp_cpu_mtid == mtid)
356 return 0;
357 cc = __pcpu_sigp(0, SIGP_SET_MULTI_THREADING, mtid, NULL);
358 if (cc == 0) {
359 smp_cpu_mtid = mtid;
360 smp_cpu_mt_shift = 0;
361 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift))
362 smp_cpu_mt_shift++;
363 pcpu_devices[0].address = stap();
364 }
365 return cc;
366}
367
368/*
369 * Call function on an online CPU.
370 */
371void smp_call_online_cpu(void (*func)(void *), void *data)
372{
373 struct pcpu *pcpu;
374
375 /* Use the current cpu if it is online. */
376 pcpu = pcpu_find_address(cpu_online_mask, stap());
377 if (!pcpu)
378 /* Use the first online cpu. */
379 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
380 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
381}
382
383/*
384 * Call function on the ipl CPU.
385 */
386void smp_call_ipl_cpu(void (*func)(void *), void *data)
387{
388 struct lowcore *lc = pcpu_devices->lowcore;
389
390 if (pcpu_devices[0].address == stap())
391 lc = &S390_lowcore;
392
393 pcpu_delegate(&pcpu_devices[0], func, data,
394 lc->nodat_stack);
395}
396
397int smp_find_processor_id(u16 address)
398{
399 int cpu;
400
401 for_each_present_cpu(cpu)
402 if (pcpu_devices[cpu].address == address)
403 return cpu;
404 return -1;
405}
406
407void schedule_mcck_handler(void)
408{
409 pcpu_ec_call(pcpu_devices + smp_processor_id(), ec_mcck_pending);
410}
411
412bool notrace arch_vcpu_is_preempted(int cpu)
413{
414 if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu))
415 return false;
416 if (pcpu_running(pcpu_devices + cpu))
417 return false;
418 return true;
419}
420EXPORT_SYMBOL(arch_vcpu_is_preempted);
421
422void notrace smp_yield_cpu(int cpu)
423{
424 if (!MACHINE_HAS_DIAG9C)
425 return;
426 diag_stat_inc_norecursion(DIAG_STAT_X09C);
427 asm volatile("diag %0,0,0x9c"
428 : : "d" (pcpu_devices[cpu].address));
429}
430
431/*
432 * Send cpus emergency shutdown signal. This gives the cpus the
433 * opportunity to complete outstanding interrupts.
434 */
435void notrace smp_emergency_stop(void)
436{
437 cpumask_t cpumask;
438 u64 end;
439 int cpu;
440
441 cpumask_copy(&cpumask, cpu_online_mask);
442 cpumask_clear_cpu(smp_processor_id(), &cpumask);
443
444 end = get_tod_clock() + (1000000UL << 12);
445 for_each_cpu(cpu, &cpumask) {
446 struct pcpu *pcpu = pcpu_devices + cpu;
447 set_bit(ec_stop_cpu, &pcpu->ec_mask);
448 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
449 0, NULL) == SIGP_CC_BUSY &&
450 get_tod_clock() < end)
451 cpu_relax();
452 }
453 while (get_tod_clock() < end) {
454 for_each_cpu(cpu, &cpumask)
455 if (pcpu_stopped(pcpu_devices + cpu))
456 cpumask_clear_cpu(cpu, &cpumask);
457 if (cpumask_empty(&cpumask))
458 break;
459 cpu_relax();
460 }
461}
462NOKPROBE_SYMBOL(smp_emergency_stop);
463
464/*
465 * Stop all cpus but the current one.
466 */
467void smp_send_stop(void)
468{
469 int cpu;
470
471 /* Disable all interrupts/machine checks */
472 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
473 trace_hardirqs_off();
474
475 debug_set_critical();
476
477 if (oops_in_progress)
478 smp_emergency_stop();
479
480 /* stop all processors */
481 for_each_online_cpu(cpu) {
482 if (cpu == smp_processor_id())
483 continue;
484 pcpu_sigp_retry(pcpu_devices + cpu, SIGP_STOP, 0);
485 while (!pcpu_stopped(pcpu_devices + cpu))
486 cpu_relax();
487 }
488}
489
490/*
491 * This is the main routine where commands issued by other
492 * cpus are handled.
493 */
494static void smp_handle_ext_call(void)
495{
496 unsigned long bits;
497
498 /* handle bit signal external calls */
499 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
500 if (test_bit(ec_stop_cpu, &bits))
501 smp_stop_cpu();
502 if (test_bit(ec_schedule, &bits))
503 scheduler_ipi();
504 if (test_bit(ec_call_function_single, &bits))
505 generic_smp_call_function_single_interrupt();
506 if (test_bit(ec_mcck_pending, &bits))
507 s390_handle_mcck();
508}
509
510static void do_ext_call_interrupt(struct ext_code ext_code,
511 unsigned int param32, unsigned long param64)
512{
513 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
514 smp_handle_ext_call();
515}
516
517void arch_send_call_function_ipi_mask(const struct cpumask *mask)
518{
519 int cpu;
520
521 for_each_cpu(cpu, mask)
522 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
523}
524
525void arch_send_call_function_single_ipi(int cpu)
526{
527 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
528}
529
530/*
531 * this function sends a 'reschedule' IPI to another CPU.
532 * it goes straight through and wastes no time serializing
533 * anything. Worst case is that we lose a reschedule ...
534 */
535void smp_send_reschedule(int cpu)
536{
537 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
538}
539
540/*
541 * parameter area for the set/clear control bit callbacks
542 */
543struct ec_creg_mask_parms {
544 unsigned long orval;
545 unsigned long andval;
546 int cr;
547};
548
549/*
550 * callback for setting/clearing control bits
551 */
552static void smp_ctl_bit_callback(void *info)
553{
554 struct ec_creg_mask_parms *pp = info;
555 unsigned long cregs[16];
556
557 __ctl_store(cregs, 0, 15);
558 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
559 __ctl_load(cregs, 0, 15);
560}
561
562/*
563 * Set a bit in a control register of all cpus
564 */
565void smp_ctl_set_bit(int cr, int bit)
566{
567 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
568
569 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
570}
571EXPORT_SYMBOL(smp_ctl_set_bit);
572
573/*
574 * Clear a bit in a control register of all cpus
575 */
576void smp_ctl_clear_bit(int cr, int bit)
577{
578 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
579
580 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
581}
582EXPORT_SYMBOL(smp_ctl_clear_bit);
583
584#ifdef CONFIG_CRASH_DUMP
585
586int smp_store_status(int cpu)
587{
588 struct pcpu *pcpu = pcpu_devices + cpu;
589 unsigned long pa;
590
591 pa = __pa(&pcpu->lowcore->floating_pt_save_area);
592 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS,
593 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
594 return -EIO;
595 if (!MACHINE_HAS_VX && !MACHINE_HAS_GS)
596 return 0;
597 pa = __pa(pcpu->lowcore->mcesad & MCESA_ORIGIN_MASK);
598 if (MACHINE_HAS_GS)
599 pa |= pcpu->lowcore->mcesad & MCESA_LC_MASK;
600 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
601 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
602 return -EIO;
603 return 0;
604}
605
606/*
607 * Collect CPU state of the previous, crashed system.
608 * There are four cases:
609 * 1) standard zfcp dump
610 * condition: OLDMEM_BASE == NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
611 * The state for all CPUs except the boot CPU needs to be collected
612 * with sigp stop-and-store-status. The boot CPU state is located in
613 * the absolute lowcore of the memory stored in the HSA. The zcore code
614 * will copy the boot CPU state from the HSA.
615 * 2) stand-alone kdump for SCSI (zfcp dump with swapped memory)
616 * condition: OLDMEM_BASE != NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
617 * The state for all CPUs except the boot CPU needs to be collected
618 * with sigp stop-and-store-status. The firmware or the boot-loader
619 * stored the registers of the boot CPU in the absolute lowcore in the
620 * memory of the old system.
621 * 3) kdump and the old kernel did not store the CPU state,
622 * or stand-alone kdump for DASD
623 * condition: OLDMEM_BASE != NULL && !is_kdump_kernel()
624 * The state for all CPUs except the boot CPU needs to be collected
625 * with sigp stop-and-store-status. The kexec code or the boot-loader
626 * stored the registers of the boot CPU in the memory of the old system.
627 * 4) kdump and the old kernel stored the CPU state
628 * condition: OLDMEM_BASE != NULL && is_kdump_kernel()
629 * This case does not exist for s390 anymore, setup_arch explicitly
630 * deactivates the elfcorehdr= kernel parameter
631 */
632static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr,
633 bool is_boot_cpu, unsigned long page)
634{
635 __vector128 *vxrs = (__vector128 *) page;
636
637 if (is_boot_cpu)
638 vxrs = boot_cpu_vector_save_area;
639 else
640 __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page);
641 save_area_add_vxrs(sa, vxrs);
642}
643
644static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr,
645 bool is_boot_cpu, unsigned long page)
646{
647 void *regs = (void *) page;
648
649 if (is_boot_cpu)
650 copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512);
651 else
652 __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page);
653 save_area_add_regs(sa, regs);
654}
655
656void __init smp_save_dump_cpus(void)
657{
658 int addr, boot_cpu_addr, max_cpu_addr;
659 struct save_area *sa;
660 unsigned long page;
661 bool is_boot_cpu;
662
663 if (!(OLDMEM_BASE || ipl_info.type == IPL_TYPE_FCP_DUMP))
664 /* No previous system present, normal boot. */
665 return;
666 /* Allocate a page as dumping area for the store status sigps */
667 page = memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE, 0, 1UL << 31);
668 if (!page)
669 panic("ERROR: Failed to allocate %lx bytes below %lx\n",
670 PAGE_SIZE, 1UL << 31);
671
672 /* Set multi-threading state to the previous system. */
673 pcpu_set_smt(sclp.mtid_prev);
674 boot_cpu_addr = stap();
675 max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;
676 for (addr = 0; addr <= max_cpu_addr; addr++) {
677 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==
678 SIGP_CC_NOT_OPERATIONAL)
679 continue;
680 is_boot_cpu = (addr == boot_cpu_addr);
681 /* Allocate save area */
682 sa = save_area_alloc(is_boot_cpu);
683 if (!sa)
684 panic("could not allocate memory for save area\n");
685 if (MACHINE_HAS_VX)
686 /* Get the vector registers */
687 smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page);
688 /*
689 * For a zfcp dump OLDMEM_BASE == NULL and the registers
690 * of the boot CPU are stored in the HSA. To retrieve
691 * these registers an SCLP request is required which is
692 * done by drivers/s390/char/zcore.c:init_cpu_info()
693 */
694 if (!is_boot_cpu || OLDMEM_BASE)
695 /* Get the CPU registers */
696 smp_save_cpu_regs(sa, addr, is_boot_cpu, page);
697 }
698 memblock_free(page, PAGE_SIZE);
699 diag_dma_ops.diag308_reset();
700 pcpu_set_smt(0);
701}
702#endif /* CONFIG_CRASH_DUMP */
703
704void smp_cpu_set_polarization(int cpu, int val)
705{
706 pcpu_devices[cpu].polarization = val;
707}
708
709int smp_cpu_get_polarization(int cpu)
710{
711 return pcpu_devices[cpu].polarization;
712}
713
714int smp_cpu_get_cpu_address(int cpu)
715{
716 return pcpu_devices[cpu].address;
717}
718
719static void __ref smp_get_core_info(struct sclp_core_info *info, int early)
720{
721 static int use_sigp_detection;
722 int address;
723
724 if (use_sigp_detection || sclp_get_core_info(info, early)) {
725 use_sigp_detection = 1;
726 for (address = 0;
727 address < (SCLP_MAX_CORES << smp_cpu_mt_shift);
728 address += (1U << smp_cpu_mt_shift)) {
729 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) ==
730 SIGP_CC_NOT_OPERATIONAL)
731 continue;
732 info->core[info->configured].core_id =
733 address >> smp_cpu_mt_shift;
734 info->configured++;
735 }
736 info->combined = info->configured;
737 }
738}
739
740static int smp_add_present_cpu(int cpu);
741
742static int smp_add_core(struct sclp_core_entry *core, cpumask_t *avail,
743 bool configured, bool early)
744{
745 struct pcpu *pcpu;
746 int cpu, nr, i;
747 u16 address;
748
749 nr = 0;
750 if (sclp.has_core_type && core->type != boot_core_type)
751 return nr;
752 cpu = cpumask_first(avail);
753 address = core->core_id << smp_cpu_mt_shift;
754 for (i = 0; (i <= smp_cpu_mtid) && (cpu < nr_cpu_ids); i++) {
755 if (pcpu_find_address(cpu_present_mask, address + i))
756 continue;
757 pcpu = pcpu_devices + cpu;
758 pcpu->address = address + i;
759 if (configured)
760 pcpu->state = CPU_STATE_CONFIGURED;
761 else
762 pcpu->state = CPU_STATE_STANDBY;
763 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
764 set_cpu_present(cpu, true);
765 if (!early && smp_add_present_cpu(cpu) != 0)
766 set_cpu_present(cpu, false);
767 else
768 nr++;
769 cpumask_clear_cpu(cpu, avail);
770 cpu = cpumask_next(cpu, avail);
771 }
772 return nr;
773}
774
775static int __smp_rescan_cpus(struct sclp_core_info *info, bool early)
776{
777 struct sclp_core_entry *core;
778 cpumask_t avail;
779 bool configured;
780 u16 core_id;
781 int nr, i;
782
783 nr = 0;
784 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
785 /*
786 * Add IPL core first (which got logical CPU number 0) to make sure
787 * that all SMT threads get subsequent logical CPU numbers.
788 */
789 if (early) {
790 core_id = pcpu_devices[0].address >> smp_cpu_mt_shift;
791 for (i = 0; i < info->configured; i++) {
792 core = &info->core[i];
793 if (core->core_id == core_id) {
794 nr += smp_add_core(core, &avail, true, early);
795 break;
796 }
797 }
798 }
799 for (i = 0; i < info->combined; i++) {
800 configured = i < info->configured;
801 nr += smp_add_core(&info->core[i], &avail, configured, early);
802 }
803 return nr;
804}
805
806void __init smp_detect_cpus(void)
807{
808 unsigned int cpu, mtid, c_cpus, s_cpus;
809 struct sclp_core_info *info;
810 u16 address;
811
812 /* Get CPU information */
813 info = memblock_alloc(sizeof(*info), 8);
814 if (!info)
815 panic("%s: Failed to allocate %zu bytes align=0x%x\n",
816 __func__, sizeof(*info), 8);
817 smp_get_core_info(info, 1);
818 /* Find boot CPU type */
819 if (sclp.has_core_type) {
820 address = stap();
821 for (cpu = 0; cpu < info->combined; cpu++)
822 if (info->core[cpu].core_id == address) {
823 /* The boot cpu dictates the cpu type. */
824 boot_core_type = info->core[cpu].type;
825 break;
826 }
827 if (cpu >= info->combined)
828 panic("Could not find boot CPU type");
829 }
830
831 /* Set multi-threading state for the current system */
832 mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp;
833 mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1;
834 pcpu_set_smt(mtid);
835
836 /* Print number of CPUs */
837 c_cpus = s_cpus = 0;
838 for (cpu = 0; cpu < info->combined; cpu++) {
839 if (sclp.has_core_type &&
840 info->core[cpu].type != boot_core_type)
841 continue;
842 if (cpu < info->configured)
843 c_cpus += smp_cpu_mtid + 1;
844 else
845 s_cpus += smp_cpu_mtid + 1;
846 }
847 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
848
849 /* Add CPUs present at boot */
850 get_online_cpus();
851 __smp_rescan_cpus(info, true);
852 put_online_cpus();
853 memblock_free_early((unsigned long)info, sizeof(*info));
854}
855
856static void smp_init_secondary(void)
857{
858 int cpu = smp_processor_id();
859
860 S390_lowcore.last_update_clock = get_tod_clock();
861 restore_access_regs(S390_lowcore.access_regs_save_area);
862 set_cpu_flag(CIF_ASCE_PRIMARY);
863 set_cpu_flag(CIF_ASCE_SECONDARY);
864 cpu_init();
865 preempt_disable();
866 init_cpu_timer();
867 vtime_init();
868 pfault_init();
869 notify_cpu_starting(cpu);
870 if (topology_cpu_dedicated(cpu))
871 set_cpu_flag(CIF_DEDICATED_CPU);
872 else
873 clear_cpu_flag(CIF_DEDICATED_CPU);
874 set_cpu_online(cpu, true);
875 update_cpu_masks();
876 inc_irq_stat(CPU_RST);
877 local_irq_enable();
878 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
879}
880
881/*
882 * Activate a secondary processor.
883 */
884static void __no_sanitize_address smp_start_secondary(void *cpuvoid)
885{
886 S390_lowcore.restart_stack = (unsigned long) restart_stack;
887 S390_lowcore.restart_fn = (unsigned long) do_restart;
888 S390_lowcore.restart_data = 0;
889 S390_lowcore.restart_source = -1UL;
890 __ctl_load(S390_lowcore.cregs_save_area, 0, 15);
891 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
892 CALL_ON_STACK_NORETURN(smp_init_secondary, S390_lowcore.kernel_stack);
893}
894
895/* Upping and downing of CPUs */
896int __cpu_up(unsigned int cpu, struct task_struct *tidle)
897{
898 struct pcpu *pcpu;
899 int base, i, rc;
900
901 pcpu = pcpu_devices + cpu;
902 if (pcpu->state != CPU_STATE_CONFIGURED)
903 return -EIO;
904 base = smp_get_base_cpu(cpu);
905 for (i = 0; i <= smp_cpu_mtid; i++) {
906 if (base + i < nr_cpu_ids)
907 if (cpu_online(base + i))
908 break;
909 }
910 /*
911 * If this is the first CPU of the core to get online
912 * do an initial CPU reset.
913 */
914 if (i > smp_cpu_mtid &&
915 pcpu_sigp_retry(pcpu_devices + base, SIGP_INITIAL_CPU_RESET, 0) !=
916 SIGP_CC_ORDER_CODE_ACCEPTED)
917 return -EIO;
918
919 rc = pcpu_alloc_lowcore(pcpu, cpu);
920 if (rc)
921 return rc;
922 pcpu_prepare_secondary(pcpu, cpu);
923 pcpu_attach_task(pcpu, tidle);
924 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
925 /* Wait until cpu puts itself in the online & active maps */
926 while (!cpu_online(cpu))
927 cpu_relax();
928 return 0;
929}
930
931static unsigned int setup_possible_cpus __initdata;
932
933static int __init _setup_possible_cpus(char *s)
934{
935 get_option(&s, &setup_possible_cpus);
936 return 0;
937}
938early_param("possible_cpus", _setup_possible_cpus);
939
940int __cpu_disable(void)
941{
942 unsigned long cregs[16];
943
944 /* Handle possible pending IPIs */
945 smp_handle_ext_call();
946 set_cpu_online(smp_processor_id(), false);
947 update_cpu_masks();
948 /* Disable pseudo page faults on this cpu. */
949 pfault_fini();
950 /* Disable interrupt sources via control register. */
951 __ctl_store(cregs, 0, 15);
952 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
953 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
954 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
955 __ctl_load(cregs, 0, 15);
956 clear_cpu_flag(CIF_NOHZ_DELAY);
957 return 0;
958}
959
960void __cpu_die(unsigned int cpu)
961{
962 struct pcpu *pcpu;
963
964 /* Wait until target cpu is down */
965 pcpu = pcpu_devices + cpu;
966 while (!pcpu_stopped(pcpu))
967 cpu_relax();
968 pcpu_free_lowcore(pcpu);
969 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
970 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
971}
972
973void __noreturn cpu_die(void)
974{
975 idle_task_exit();
976 __bpon();
977 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
978 for (;;) ;
979}
980
981void __init smp_fill_possible_mask(void)
982{
983 unsigned int possible, sclp_max, cpu;
984
985 sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1;
986 sclp_max = min(smp_max_threads, sclp_max);
987 sclp_max = (sclp.max_cores * sclp_max) ?: nr_cpu_ids;
988 possible = setup_possible_cpus ?: nr_cpu_ids;
989 possible = min(possible, sclp_max);
990 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
991 set_cpu_possible(cpu, true);
992}
993
994void __init smp_prepare_cpus(unsigned int max_cpus)
995{
996 /* request the 0x1201 emergency signal external interrupt */
997 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
998 panic("Couldn't request external interrupt 0x1201");
999 /* request the 0x1202 external call external interrupt */
1000 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
1001 panic("Couldn't request external interrupt 0x1202");
1002}
1003
1004void __init smp_prepare_boot_cpu(void)
1005{
1006 struct pcpu *pcpu = pcpu_devices;
1007
1008 WARN_ON(!cpu_present(0) || !cpu_online(0));
1009 pcpu->state = CPU_STATE_CONFIGURED;
1010 pcpu->lowcore = (struct lowcore *)(unsigned long) store_prefix();
1011 S390_lowcore.percpu_offset = __per_cpu_offset[0];
1012 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
1013}
1014
1015void __init smp_setup_processor_id(void)
1016{
1017 pcpu_devices[0].address = stap();
1018 S390_lowcore.cpu_nr = 0;
1019 S390_lowcore.spinlock_lockval = arch_spin_lockval(0);
1020 S390_lowcore.spinlock_index = 0;
1021}
1022
1023/*
1024 * the frequency of the profiling timer can be changed
1025 * by writing a multiplier value into /proc/profile.
1026 *
1027 * usually you want to run this on all CPUs ;)
1028 */
1029int setup_profiling_timer(unsigned int multiplier)
1030{
1031 return 0;
1032}
1033
1034static ssize_t cpu_configure_show(struct device *dev,
1035 struct device_attribute *attr, char *buf)
1036{
1037 ssize_t count;
1038
1039 mutex_lock(&smp_cpu_state_mutex);
1040 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
1041 mutex_unlock(&smp_cpu_state_mutex);
1042 return count;
1043}
1044
1045static ssize_t cpu_configure_store(struct device *dev,
1046 struct device_attribute *attr,
1047 const char *buf, size_t count)
1048{
1049 struct pcpu *pcpu;
1050 int cpu, val, rc, i;
1051 char delim;
1052
1053 if (sscanf(buf, "%d %c", &val, &delim) != 1)
1054 return -EINVAL;
1055 if (val != 0 && val != 1)
1056 return -EINVAL;
1057 get_online_cpus();
1058 mutex_lock(&smp_cpu_state_mutex);
1059 rc = -EBUSY;
1060 /* disallow configuration changes of online cpus and cpu 0 */
1061 cpu = dev->id;
1062 cpu = smp_get_base_cpu(cpu);
1063 if (cpu == 0)
1064 goto out;
1065 for (i = 0; i <= smp_cpu_mtid; i++)
1066 if (cpu_online(cpu + i))
1067 goto out;
1068 pcpu = pcpu_devices + cpu;
1069 rc = 0;
1070 switch (val) {
1071 case 0:
1072 if (pcpu->state != CPU_STATE_CONFIGURED)
1073 break;
1074 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift);
1075 if (rc)
1076 break;
1077 for (i = 0; i <= smp_cpu_mtid; i++) {
1078 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1079 continue;
1080 pcpu[i].state = CPU_STATE_STANDBY;
1081 smp_cpu_set_polarization(cpu + i,
1082 POLARIZATION_UNKNOWN);
1083 }
1084 topology_expect_change();
1085 break;
1086 case 1:
1087 if (pcpu->state != CPU_STATE_STANDBY)
1088 break;
1089 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift);
1090 if (rc)
1091 break;
1092 for (i = 0; i <= smp_cpu_mtid; i++) {
1093 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1094 continue;
1095 pcpu[i].state = CPU_STATE_CONFIGURED;
1096 smp_cpu_set_polarization(cpu + i,
1097 POLARIZATION_UNKNOWN);
1098 }
1099 topology_expect_change();
1100 break;
1101 default:
1102 break;
1103 }
1104out:
1105 mutex_unlock(&smp_cpu_state_mutex);
1106 put_online_cpus();
1107 return rc ? rc : count;
1108}
1109static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
1110
1111static ssize_t show_cpu_address(struct device *dev,
1112 struct device_attribute *attr, char *buf)
1113{
1114 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
1115}
1116static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
1117
1118static struct attribute *cpu_common_attrs[] = {
1119 &dev_attr_configure.attr,
1120 &dev_attr_address.attr,
1121 NULL,
1122};
1123
1124static struct attribute_group cpu_common_attr_group = {
1125 .attrs = cpu_common_attrs,
1126};
1127
1128static struct attribute *cpu_online_attrs[] = {
1129 &dev_attr_idle_count.attr,
1130 &dev_attr_idle_time_us.attr,
1131 NULL,
1132};
1133
1134static struct attribute_group cpu_online_attr_group = {
1135 .attrs = cpu_online_attrs,
1136};
1137
1138static int smp_cpu_online(unsigned int cpu)
1139{
1140 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1141
1142 return sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1143}
1144
1145static int smp_cpu_pre_down(unsigned int cpu)
1146{
1147 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1148
1149 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1150 return 0;
1151}
1152
1153static int smp_add_present_cpu(int cpu)
1154{
1155 struct device *s;
1156 struct cpu *c;
1157 int rc;
1158
1159 c = kzalloc(sizeof(*c), GFP_KERNEL);
1160 if (!c)
1161 return -ENOMEM;
1162 per_cpu(cpu_device, cpu) = c;
1163 s = &c->dev;
1164 c->hotpluggable = 1;
1165 rc = register_cpu(c, cpu);
1166 if (rc)
1167 goto out;
1168 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1169 if (rc)
1170 goto out_cpu;
1171 rc = topology_cpu_init(c);
1172 if (rc)
1173 goto out_topology;
1174 return 0;
1175
1176out_topology:
1177 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1178out_cpu:
1179 unregister_cpu(c);
1180out:
1181 return rc;
1182}
1183
1184int __ref smp_rescan_cpus(void)
1185{
1186 struct sclp_core_info *info;
1187 int nr;
1188
1189 info = kzalloc(sizeof(*info), GFP_KERNEL);
1190 if (!info)
1191 return -ENOMEM;
1192 smp_get_core_info(info, 0);
1193 get_online_cpus();
1194 mutex_lock(&smp_cpu_state_mutex);
1195 nr = __smp_rescan_cpus(info, false);
1196 mutex_unlock(&smp_cpu_state_mutex);
1197 put_online_cpus();
1198 kfree(info);
1199 if (nr)
1200 topology_schedule_update();
1201 return 0;
1202}
1203
1204static ssize_t __ref rescan_store(struct device *dev,
1205 struct device_attribute *attr,
1206 const char *buf,
1207 size_t count)
1208{
1209 int rc;
1210
1211 rc = lock_device_hotplug_sysfs();
1212 if (rc)
1213 return rc;
1214 rc = smp_rescan_cpus();
1215 unlock_device_hotplug();
1216 return rc ? rc : count;
1217}
1218static DEVICE_ATTR_WO(rescan);
1219
1220static int __init s390_smp_init(void)
1221{
1222 int cpu, rc = 0;
1223
1224 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1225 if (rc)
1226 return rc;
1227 for_each_present_cpu(cpu) {
1228 rc = smp_add_present_cpu(cpu);
1229 if (rc)
1230 goto out;
1231 }
1232
1233 rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "s390/smp:online",
1234 smp_cpu_online, smp_cpu_pre_down);
1235 rc = rc <= 0 ? rc : 0;
1236out:
1237 return rc;
1238}
1239subsys_initcall(s390_smp_init);