1 // SPDX-License-Identifier: GPL-2.0
3 * SMP related functions
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>,
10 * based on other smp stuff by
11 * (c) 1995 Alan Cox, CymruNET Ltd <alan@cymru.net>
12 * (c) 1998 Ingo Molnar
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.
19 #define KMSG_COMPONENT "cpu"
20 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
22 #include <linux/workqueue.h>
23 #include <linux/memblock.h>
24 #include <linux/export.h>
25 #include <linux/init.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>
41 #include <asm/switch_to.h>
42 #include <asm/facility.h>
44 #include <asm/setup.h>
46 #include <asm/tlbflush.h>
47 #include <asm/vtimer.h>
48 #include <asm/lowcore.h>
50 #include <asm/debug.h>
51 #include <asm/os_info.h>
55 #include <asm/stacktrace.h>
56 #include <asm/topology.h>
62 ec_call_function_single,
72 static DEFINE_PER_CPU(struct cpu *, cpu_device);
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 */
83 static u8 boot_core_type;
84 static struct pcpu pcpu_devices[NR_CPUS];
86 unsigned int smp_cpu_mt_shift;
87 EXPORT_SYMBOL(smp_cpu_mt_shift);
89 unsigned int smp_cpu_mtid;
90 EXPORT_SYMBOL(smp_cpu_mtid);
92 #ifdef CONFIG_CRASH_DUMP
93 __vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
96 static unsigned int smp_max_threads __initdata = -1U;
98 static int __init early_nosmt(char *s)
103 early_param("nosmt", early_nosmt);
105 static int __init early_smt(char *s)
107 get_option(&s, &smp_max_threads);
110 early_param("smt", early_smt);
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.
116 DEFINE_MUTEX(smp_cpu_state_mutex);
119 * Signal processor helper functions.
121 static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm)
126 cc = __pcpu_sigp(addr, order, parm, NULL);
127 if (cc != SIGP_CC_BUSY)
133 static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
137 for (retry = 0; ; retry++) {
138 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
139 if (cc != SIGP_CC_BUSY)
147 static inline int pcpu_stopped(struct pcpu *pcpu)
151 if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
152 0, &status) != SIGP_CC_STATUS_STORED)
154 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
157 static inline int pcpu_running(struct pcpu *pcpu)
159 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
160 0, NULL) != SIGP_CC_STATUS_STORED)
162 /* Status stored condition code is equivalent to cpu not running. */
167 * Find struct pcpu by cpu address.
169 static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address)
173 for_each_cpu(cpu, mask)
174 if (pcpu_devices[cpu].address == address)
175 return pcpu_devices + cpu;
179 static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
183 if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
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);
190 static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
192 unsigned long async_stack, nodat_stack;
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)
202 nodat_stack = pcpu->lowcore->nodat_stack - STACK_INIT_OFFSET;
204 async_stack = stack_alloc();
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;
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))
220 lowcore_ptr[cpu] = lc;
221 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
225 stack_free(async_stack);
227 if (pcpu != &pcpu_devices[0]) {
228 free_pages(nodat_stack, THREAD_SIZE_ORDER);
229 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
234 static void pcpu_free_lowcore(struct pcpu *pcpu)
236 unsigned long async_stack, nodat_stack, lowcore;
238 nodat_stack = pcpu->lowcore->nodat_stack - STACK_INIT_OFFSET;
239 async_stack = pcpu->lowcore->async_stack - STACK_INIT_OFFSET;
240 lowcore = (unsigned long) pcpu->lowcore;
242 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
243 lowcore_ptr[pcpu - pcpu_devices] = NULL;
244 nmi_free_per_cpu(pcpu->lowcore);
245 stack_free(async_stack);
246 if (pcpu == &pcpu_devices[0])
248 free_pages(nodat_stack, THREAD_SIZE_ORDER);
249 free_pages(lowcore, LC_ORDER);
252 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
254 struct lowcore *lc = pcpu->lowcore;
256 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
257 cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
259 lc->spinlock_lockval = arch_spin_lockval(cpu);
260 lc->spinlock_index = 0;
261 lc->percpu_offset = __per_cpu_offset[cpu];
262 lc->kernel_asce = S390_lowcore.kernel_asce;
263 lc->user_asce = s390_invalid_asce;
264 lc->machine_flags = S390_lowcore.machine_flags;
265 lc->user_timer = lc->system_timer =
266 lc->steal_timer = lc->avg_steal_timer = 0;
267 __ctl_store(lc->cregs_save_area, 0, 15);
268 lc->cregs_save_area[1] = lc->kernel_asce;
269 lc->cregs_save_area[7] = lc->user_asce;
270 save_access_regs((unsigned int *) lc->access_regs_save_area);
271 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
272 sizeof(lc->stfle_fac_list));
273 memcpy(lc->alt_stfle_fac_list, S390_lowcore.alt_stfle_fac_list,
274 sizeof(lc->alt_stfle_fac_list));
275 arch_spin_lock_setup(cpu);
278 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
280 struct lowcore *lc = pcpu->lowcore;
282 lc->kernel_stack = (unsigned long) task_stack_page(tsk)
283 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
284 lc->current_task = (unsigned long) tsk;
286 lc->current_pid = tsk->pid;
287 lc->user_timer = tsk->thread.user_timer;
288 lc->guest_timer = tsk->thread.guest_timer;
289 lc->system_timer = tsk->thread.system_timer;
290 lc->hardirq_timer = tsk->thread.hardirq_timer;
291 lc->softirq_timer = tsk->thread.softirq_timer;
295 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
297 struct lowcore *lc = pcpu->lowcore;
299 lc->restart_stack = lc->nodat_stack;
300 lc->restart_fn = (unsigned long) func;
301 lc->restart_data = (unsigned long) data;
302 lc->restart_source = -1UL;
303 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
307 * Call function via PSW restart on pcpu and stop the current cpu.
309 static void __pcpu_delegate(void (*func)(void*), void *data)
311 func(data); /* should not return */
314 static void __no_sanitize_address pcpu_delegate(struct pcpu *pcpu,
315 void (*func)(void *),
316 void *data, unsigned long stack)
318 struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
319 unsigned long source_cpu = stap();
321 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
322 if (pcpu->address == source_cpu)
323 CALL_ON_STACK(__pcpu_delegate, stack, 2, func, data);
324 /* Stop target cpu (if func returns this stops the current cpu). */
325 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
326 /* Restart func on the target cpu and stop the current cpu. */
327 mem_assign_absolute(lc->restart_stack, stack);
328 mem_assign_absolute(lc->restart_fn, (unsigned long) func);
329 mem_assign_absolute(lc->restart_data, (unsigned long) data);
330 mem_assign_absolute(lc->restart_source, source_cpu);
333 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
334 " brc 2,0b # busy, try again\n"
335 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
336 " brc 2,1b # busy, try again\n"
337 : : "d" (pcpu->address), "d" (source_cpu),
338 "K" (SIGP_RESTART), "K" (SIGP_STOP)
344 * Enable additional logical cpus for multi-threading.
346 static int pcpu_set_smt(unsigned int mtid)
350 if (smp_cpu_mtid == mtid)
352 cc = __pcpu_sigp(0, SIGP_SET_MULTI_THREADING, mtid, NULL);
355 smp_cpu_mt_shift = 0;
356 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift))
358 pcpu_devices[0].address = stap();
364 * Call function on an online CPU.
366 void smp_call_online_cpu(void (*func)(void *), void *data)
370 /* Use the current cpu if it is online. */
371 pcpu = pcpu_find_address(cpu_online_mask, stap());
373 /* Use the first online cpu. */
374 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
375 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
379 * Call function on the ipl CPU.
381 void smp_call_ipl_cpu(void (*func)(void *), void *data)
383 struct lowcore *lc = pcpu_devices->lowcore;
385 if (pcpu_devices[0].address == stap())
388 pcpu_delegate(&pcpu_devices[0], func, data,
392 int smp_find_processor_id(u16 address)
396 for_each_present_cpu(cpu)
397 if (pcpu_devices[cpu].address == address)
402 void schedule_mcck_handler(void)
404 pcpu_ec_call(pcpu_devices + smp_processor_id(), ec_mcck_pending);
407 bool notrace arch_vcpu_is_preempted(int cpu)
409 if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu))
411 if (pcpu_running(pcpu_devices + cpu))
415 EXPORT_SYMBOL(arch_vcpu_is_preempted);
417 void notrace smp_yield_cpu(int cpu)
419 if (!MACHINE_HAS_DIAG9C)
421 diag_stat_inc_norecursion(DIAG_STAT_X09C);
422 asm volatile("diag %0,0,0x9c"
423 : : "d" (pcpu_devices[cpu].address));
427 * Send cpus emergency shutdown signal. This gives the cpus the
428 * opportunity to complete outstanding interrupts.
430 void notrace smp_emergency_stop(void)
436 cpumask_copy(&cpumask, cpu_online_mask);
437 cpumask_clear_cpu(smp_processor_id(), &cpumask);
439 end = get_tod_clock() + (1000000UL << 12);
440 for_each_cpu(cpu, &cpumask) {
441 struct pcpu *pcpu = pcpu_devices + cpu;
442 set_bit(ec_stop_cpu, &pcpu->ec_mask);
443 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
444 0, NULL) == SIGP_CC_BUSY &&
445 get_tod_clock() < end)
448 while (get_tod_clock() < end) {
449 for_each_cpu(cpu, &cpumask)
450 if (pcpu_stopped(pcpu_devices + cpu))
451 cpumask_clear_cpu(cpu, &cpumask);
452 if (cpumask_empty(&cpumask))
457 NOKPROBE_SYMBOL(smp_emergency_stop);
460 * Stop all cpus but the current one.
462 void smp_send_stop(void)
466 /* Disable all interrupts/machine checks */
467 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
468 trace_hardirqs_off();
470 debug_set_critical();
472 if (oops_in_progress)
473 smp_emergency_stop();
475 /* stop all processors */
476 for_each_online_cpu(cpu) {
477 if (cpu == smp_processor_id())
479 pcpu_sigp_retry(pcpu_devices + cpu, SIGP_STOP, 0);
480 while (!pcpu_stopped(pcpu_devices + cpu))
486 * This is the main routine where commands issued by other
489 static void smp_handle_ext_call(void)
493 /* handle bit signal external calls */
494 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
495 if (test_bit(ec_stop_cpu, &bits))
497 if (test_bit(ec_schedule, &bits))
499 if (test_bit(ec_call_function_single, &bits))
500 generic_smp_call_function_single_interrupt();
501 if (test_bit(ec_mcck_pending, &bits))
505 static void do_ext_call_interrupt(struct ext_code ext_code,
506 unsigned int param32, unsigned long param64)
508 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
509 smp_handle_ext_call();
512 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
516 for_each_cpu(cpu, mask)
517 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
520 void arch_send_call_function_single_ipi(int cpu)
522 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
526 * this function sends a 'reschedule' IPI to another CPU.
527 * it goes straight through and wastes no time serializing
528 * anything. Worst case is that we lose a reschedule ...
530 void smp_send_reschedule(int cpu)
532 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
536 * parameter area for the set/clear control bit callbacks
538 struct ec_creg_mask_parms {
540 unsigned long andval;
545 * callback for setting/clearing control bits
547 static void smp_ctl_bit_callback(void *info)
549 struct ec_creg_mask_parms *pp = info;
550 unsigned long cregs[16];
552 __ctl_store(cregs, 0, 15);
553 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
554 __ctl_load(cregs, 0, 15);
558 * Set a bit in a control register of all cpus
560 void smp_ctl_set_bit(int cr, int bit)
562 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
564 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
566 EXPORT_SYMBOL(smp_ctl_set_bit);
569 * Clear a bit in a control register of all cpus
571 void smp_ctl_clear_bit(int cr, int bit)
573 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
575 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
577 EXPORT_SYMBOL(smp_ctl_clear_bit);
579 #ifdef CONFIG_CRASH_DUMP
581 int smp_store_status(int cpu)
583 struct pcpu *pcpu = pcpu_devices + cpu;
586 pa = __pa(&pcpu->lowcore->floating_pt_save_area);
587 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS,
588 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
590 if (!MACHINE_HAS_VX && !MACHINE_HAS_GS)
592 pa = __pa(pcpu->lowcore->mcesad & MCESA_ORIGIN_MASK);
594 pa |= pcpu->lowcore->mcesad & MCESA_LC_MASK;
595 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
596 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
602 * Collect CPU state of the previous, crashed system.
603 * There are four cases:
604 * 1) standard zfcp/nvme dump
605 * condition: OLDMEM_BASE == NULL && is_ipl_type_dump() == true
606 * The state for all CPUs except the boot CPU needs to be collected
607 * with sigp stop-and-store-status. The boot CPU state is located in
608 * the absolute lowcore of the memory stored in the HSA. The zcore code
609 * will copy the boot CPU state from the HSA.
610 * 2) stand-alone kdump for SCSI/NVMe (zfcp/nvme dump with swapped memory)
611 * condition: OLDMEM_BASE != NULL && is_ipl_type_dump() == true
612 * The state for all CPUs except the boot CPU needs to be collected
613 * with sigp stop-and-store-status. The firmware or the boot-loader
614 * stored the registers of the boot CPU in the absolute lowcore in the
615 * memory of the old system.
616 * 3) kdump and the old kernel did not store the CPU state,
617 * or stand-alone kdump for DASD
618 * condition: OLDMEM_BASE != NULL && !is_kdump_kernel()
619 * The state for all CPUs except the boot CPU needs to be collected
620 * with sigp stop-and-store-status. The kexec code or the boot-loader
621 * stored the registers of the boot CPU in the memory of the old system.
622 * 4) kdump and the old kernel stored the CPU state
623 * condition: OLDMEM_BASE != NULL && is_kdump_kernel()
624 * This case does not exist for s390 anymore, setup_arch explicitly
625 * deactivates the elfcorehdr= kernel parameter
627 static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr,
628 bool is_boot_cpu, unsigned long page)
630 __vector128 *vxrs = (__vector128 *) page;
633 vxrs = boot_cpu_vector_save_area;
635 __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page);
636 save_area_add_vxrs(sa, vxrs);
639 static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr,
640 bool is_boot_cpu, unsigned long page)
642 void *regs = (void *) page;
645 copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512);
647 __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page);
648 save_area_add_regs(sa, regs);
651 void __init smp_save_dump_cpus(void)
653 int addr, boot_cpu_addr, max_cpu_addr;
654 struct save_area *sa;
658 if (!(OLDMEM_BASE || is_ipl_type_dump()))
659 /* No previous system present, normal boot. */
661 /* Allocate a page as dumping area for the store status sigps */
662 page = memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE, 0, 1UL << 31);
664 panic("ERROR: Failed to allocate %lx bytes below %lx\n",
665 PAGE_SIZE, 1UL << 31);
667 /* Set multi-threading state to the previous system. */
668 pcpu_set_smt(sclp.mtid_prev);
669 boot_cpu_addr = stap();
670 max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;
671 for (addr = 0; addr <= max_cpu_addr; addr++) {
672 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==
673 SIGP_CC_NOT_OPERATIONAL)
675 is_boot_cpu = (addr == boot_cpu_addr);
676 /* Allocate save area */
677 sa = save_area_alloc(is_boot_cpu);
679 panic("could not allocate memory for save area\n");
681 /* Get the vector registers */
682 smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page);
684 * For a zfcp/nvme dump OLDMEM_BASE == NULL and the registers
685 * of the boot CPU are stored in the HSA. To retrieve
686 * these registers an SCLP request is required which is
687 * done by drivers/s390/char/zcore.c:init_cpu_info()
689 if (!is_boot_cpu || OLDMEM_BASE)
690 /* Get the CPU registers */
691 smp_save_cpu_regs(sa, addr, is_boot_cpu, page);
693 memblock_free(page, PAGE_SIZE);
694 diag_dma_ops.diag308_reset();
697 #endif /* CONFIG_CRASH_DUMP */
699 void smp_cpu_set_polarization(int cpu, int val)
701 pcpu_devices[cpu].polarization = val;
704 int smp_cpu_get_polarization(int cpu)
706 return pcpu_devices[cpu].polarization;
709 int smp_cpu_get_cpu_address(int cpu)
711 return pcpu_devices[cpu].address;
714 static void __ref smp_get_core_info(struct sclp_core_info *info, int early)
716 static int use_sigp_detection;
719 if (use_sigp_detection || sclp_get_core_info(info, early)) {
720 use_sigp_detection = 1;
722 address < (SCLP_MAX_CORES << smp_cpu_mt_shift);
723 address += (1U << smp_cpu_mt_shift)) {
724 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) ==
725 SIGP_CC_NOT_OPERATIONAL)
727 info->core[info->configured].core_id =
728 address >> smp_cpu_mt_shift;
731 info->combined = info->configured;
735 static int smp_add_present_cpu(int cpu);
737 static int smp_add_core(struct sclp_core_entry *core, cpumask_t *avail,
738 bool configured, bool early)
745 if (sclp.has_core_type && core->type != boot_core_type)
747 cpu = cpumask_first(avail);
748 address = core->core_id << smp_cpu_mt_shift;
749 for (i = 0; (i <= smp_cpu_mtid) && (cpu < nr_cpu_ids); i++) {
750 if (pcpu_find_address(cpu_present_mask, address + i))
752 pcpu = pcpu_devices + cpu;
753 pcpu->address = address + i;
755 pcpu->state = CPU_STATE_CONFIGURED;
757 pcpu->state = CPU_STATE_STANDBY;
758 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
759 set_cpu_present(cpu, true);
760 if (!early && smp_add_present_cpu(cpu) != 0)
761 set_cpu_present(cpu, false);
764 cpumask_clear_cpu(cpu, avail);
765 cpu = cpumask_next(cpu, avail);
770 static int __smp_rescan_cpus(struct sclp_core_info *info, bool early)
772 struct sclp_core_entry *core;
779 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
781 * Add IPL core first (which got logical CPU number 0) to make sure
782 * that all SMT threads get subsequent logical CPU numbers.
785 core_id = pcpu_devices[0].address >> smp_cpu_mt_shift;
786 for (i = 0; i < info->configured; i++) {
787 core = &info->core[i];
788 if (core->core_id == core_id) {
789 nr += smp_add_core(core, &avail, true, early);
794 for (i = 0; i < info->combined; i++) {
795 configured = i < info->configured;
796 nr += smp_add_core(&info->core[i], &avail, configured, early);
801 void __init smp_detect_cpus(void)
803 unsigned int cpu, mtid, c_cpus, s_cpus;
804 struct sclp_core_info *info;
807 /* Get CPU information */
808 info = memblock_alloc(sizeof(*info), 8);
810 panic("%s: Failed to allocate %zu bytes align=0x%x\n",
811 __func__, sizeof(*info), 8);
812 smp_get_core_info(info, 1);
813 /* Find boot CPU type */
814 if (sclp.has_core_type) {
816 for (cpu = 0; cpu < info->combined; cpu++)
817 if (info->core[cpu].core_id == address) {
818 /* The boot cpu dictates the cpu type. */
819 boot_core_type = info->core[cpu].type;
822 if (cpu >= info->combined)
823 panic("Could not find boot CPU type");
826 /* Set multi-threading state for the current system */
827 mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp;
828 mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1;
831 /* Print number of CPUs */
833 for (cpu = 0; cpu < info->combined; cpu++) {
834 if (sclp.has_core_type &&
835 info->core[cpu].type != boot_core_type)
837 if (cpu < info->configured)
838 c_cpus += smp_cpu_mtid + 1;
840 s_cpus += smp_cpu_mtid + 1;
842 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
844 /* Add CPUs present at boot */
846 __smp_rescan_cpus(info, true);
848 memblock_free_early((unsigned long)info, sizeof(*info));
851 static void smp_init_secondary(void)
853 int cpu = raw_smp_processor_id();
855 S390_lowcore.last_update_clock = get_tod_clock();
856 restore_access_regs(S390_lowcore.access_regs_save_area);
858 rcu_cpu_starting(cpu);
864 notify_cpu_starting(cpu);
865 if (topology_cpu_dedicated(cpu))
866 set_cpu_flag(CIF_DEDICATED_CPU);
868 clear_cpu_flag(CIF_DEDICATED_CPU);
869 set_cpu_online(cpu, true);
871 inc_irq_stat(CPU_RST);
873 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
877 * Activate a secondary processor.
879 static void __no_sanitize_address smp_start_secondary(void *cpuvoid)
881 S390_lowcore.restart_stack = (unsigned long) restart_stack;
882 S390_lowcore.restart_fn = (unsigned long) do_restart;
883 S390_lowcore.restart_data = 0;
884 S390_lowcore.restart_source = -1UL;
885 __ctl_load(S390_lowcore.cregs_save_area, 0, 15);
886 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
887 CALL_ON_STACK_NORETURN(smp_init_secondary, S390_lowcore.kernel_stack);
890 /* Upping and downing of CPUs */
891 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
893 struct pcpu *pcpu = pcpu_devices + cpu;
896 if (pcpu->state != CPU_STATE_CONFIGURED)
898 if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) !=
899 SIGP_CC_ORDER_CODE_ACCEPTED)
902 rc = pcpu_alloc_lowcore(pcpu, cpu);
905 pcpu_prepare_secondary(pcpu, cpu);
906 pcpu_attach_task(pcpu, tidle);
907 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
908 /* Wait until cpu puts itself in the online & active maps */
909 while (!cpu_online(cpu))
914 static unsigned int setup_possible_cpus __initdata;
916 static int __init _setup_possible_cpus(char *s)
918 get_option(&s, &setup_possible_cpus);
921 early_param("possible_cpus", _setup_possible_cpus);
923 int __cpu_disable(void)
925 unsigned long cregs[16];
927 /* Handle possible pending IPIs */
928 smp_handle_ext_call();
929 set_cpu_online(smp_processor_id(), false);
931 /* Disable pseudo page faults on this cpu. */
933 /* Disable interrupt sources via control register. */
934 __ctl_store(cregs, 0, 15);
935 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
936 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
937 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
938 __ctl_load(cregs, 0, 15);
939 clear_cpu_flag(CIF_NOHZ_DELAY);
943 void __cpu_die(unsigned int cpu)
947 /* Wait until target cpu is down */
948 pcpu = pcpu_devices + cpu;
949 while (!pcpu_stopped(pcpu))
951 pcpu_free_lowcore(pcpu);
952 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
953 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
956 void __noreturn cpu_die(void)
960 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
964 void __init smp_fill_possible_mask(void)
966 unsigned int possible, sclp_max, cpu;
968 sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1;
969 sclp_max = min(smp_max_threads, sclp_max);
970 sclp_max = (sclp.max_cores * sclp_max) ?: nr_cpu_ids;
971 possible = setup_possible_cpus ?: nr_cpu_ids;
972 possible = min(possible, sclp_max);
973 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
974 set_cpu_possible(cpu, true);
977 void __init smp_prepare_cpus(unsigned int max_cpus)
979 /* request the 0x1201 emergency signal external interrupt */
980 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
981 panic("Couldn't request external interrupt 0x1201");
982 /* request the 0x1202 external call external interrupt */
983 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
984 panic("Couldn't request external interrupt 0x1202");
987 void __init smp_prepare_boot_cpu(void)
989 struct pcpu *pcpu = pcpu_devices;
991 WARN_ON(!cpu_present(0) || !cpu_online(0));
992 pcpu->state = CPU_STATE_CONFIGURED;
993 pcpu->lowcore = (struct lowcore *)(unsigned long) store_prefix();
994 S390_lowcore.percpu_offset = __per_cpu_offset[0];
995 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
998 void __init smp_setup_processor_id(void)
1000 pcpu_devices[0].address = stap();
1001 S390_lowcore.cpu_nr = 0;
1002 S390_lowcore.spinlock_lockval = arch_spin_lockval(0);
1003 S390_lowcore.spinlock_index = 0;
1007 * the frequency of the profiling timer can be changed
1008 * by writing a multiplier value into /proc/profile.
1010 * usually you want to run this on all CPUs ;)
1012 int setup_profiling_timer(unsigned int multiplier)
1017 static ssize_t cpu_configure_show(struct device *dev,
1018 struct device_attribute *attr, char *buf)
1022 mutex_lock(&smp_cpu_state_mutex);
1023 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
1024 mutex_unlock(&smp_cpu_state_mutex);
1028 static ssize_t cpu_configure_store(struct device *dev,
1029 struct device_attribute *attr,
1030 const char *buf, size_t count)
1033 int cpu, val, rc, i;
1036 if (sscanf(buf, "%d %c", &val, &delim) != 1)
1038 if (val != 0 && val != 1)
1041 mutex_lock(&smp_cpu_state_mutex);
1043 /* disallow configuration changes of online cpus and cpu 0 */
1045 cpu = smp_get_base_cpu(cpu);
1048 for (i = 0; i <= smp_cpu_mtid; i++)
1049 if (cpu_online(cpu + i))
1051 pcpu = pcpu_devices + cpu;
1055 if (pcpu->state != CPU_STATE_CONFIGURED)
1057 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift);
1060 for (i = 0; i <= smp_cpu_mtid; i++) {
1061 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1063 pcpu[i].state = CPU_STATE_STANDBY;
1064 smp_cpu_set_polarization(cpu + i,
1065 POLARIZATION_UNKNOWN);
1067 topology_expect_change();
1070 if (pcpu->state != CPU_STATE_STANDBY)
1072 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift);
1075 for (i = 0; i <= smp_cpu_mtid; i++) {
1076 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1078 pcpu[i].state = CPU_STATE_CONFIGURED;
1079 smp_cpu_set_polarization(cpu + i,
1080 POLARIZATION_UNKNOWN);
1082 topology_expect_change();
1088 mutex_unlock(&smp_cpu_state_mutex);
1090 return rc ? rc : count;
1092 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
1094 static ssize_t show_cpu_address(struct device *dev,
1095 struct device_attribute *attr, char *buf)
1097 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
1099 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
1101 static struct attribute *cpu_common_attrs[] = {
1102 &dev_attr_configure.attr,
1103 &dev_attr_address.attr,
1107 static struct attribute_group cpu_common_attr_group = {
1108 .attrs = cpu_common_attrs,
1111 static struct attribute *cpu_online_attrs[] = {
1112 &dev_attr_idle_count.attr,
1113 &dev_attr_idle_time_us.attr,
1117 static struct attribute_group cpu_online_attr_group = {
1118 .attrs = cpu_online_attrs,
1121 static int smp_cpu_online(unsigned int cpu)
1123 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1125 return sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1128 static int smp_cpu_pre_down(unsigned int cpu)
1130 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1132 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1136 static int smp_add_present_cpu(int cpu)
1142 c = kzalloc(sizeof(*c), GFP_KERNEL);
1145 per_cpu(cpu_device, cpu) = c;
1147 c->hotpluggable = 1;
1148 rc = register_cpu(c, cpu);
1151 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1154 rc = topology_cpu_init(c);
1160 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1167 int __ref smp_rescan_cpus(void)
1169 struct sclp_core_info *info;
1172 info = kzalloc(sizeof(*info), GFP_KERNEL);
1175 smp_get_core_info(info, 0);
1177 mutex_lock(&smp_cpu_state_mutex);
1178 nr = __smp_rescan_cpus(info, false);
1179 mutex_unlock(&smp_cpu_state_mutex);
1183 topology_schedule_update();
1187 static ssize_t __ref rescan_store(struct device *dev,
1188 struct device_attribute *attr,
1194 rc = lock_device_hotplug_sysfs();
1197 rc = smp_rescan_cpus();
1198 unlock_device_hotplug();
1199 return rc ? rc : count;
1201 static DEVICE_ATTR_WO(rescan);
1203 static int __init s390_smp_init(void)
1207 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1210 for_each_present_cpu(cpu) {
1211 rc = smp_add_present_cpu(cpu);
1216 rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "s390/smp:online",
1217 smp_cpu_online, smp_cpu_pre_down);
1218 rc = rc <= 0 ? rc : 0;
1222 subsys_initcall(s390_smp_init);