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/irq_work.h>
34 #include <linux/cpu.h>
35 #include <linux/slab.h>
36 #include <linux/sched/hotplug.h>
37 #include <linux/sched/task_stack.h>
38 #include <linux/crash_dump.h>
39 #include <linux/kprobes.h>
40 #include <asm/asm-offsets.h>
42 #include <asm/switch_to.h>
43 #include <asm/facility.h>
45 #include <asm/setup.h>
47 #include <asm/tlbflush.h>
48 #include <asm/vtimer.h>
49 #include <asm/lowcore.h>
51 #include <asm/debug.h>
52 #include <asm/os_info.h>
56 #include <asm/stacktrace.h>
57 #include <asm/topology.h>
63 ec_call_function_single,
74 static DEFINE_PER_CPU(struct cpu *, cpu_device);
77 unsigned long ec_mask; /* bit mask for ec_xxx functions */
78 unsigned long ec_clk; /* sigp timestamp for ec_xxx */
79 signed char state; /* physical cpu state */
80 signed char polarization; /* physical polarization */
81 u16 address; /* physical cpu address */
84 static u8 boot_core_type;
85 static struct pcpu pcpu_devices[NR_CPUS];
87 unsigned int smp_cpu_mt_shift;
88 EXPORT_SYMBOL(smp_cpu_mt_shift);
90 unsigned int smp_cpu_mtid;
91 EXPORT_SYMBOL(smp_cpu_mtid);
93 #ifdef CONFIG_CRASH_DUMP
94 __vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
97 static unsigned int smp_max_threads __initdata = -1U;
99 static int __init early_nosmt(char *s)
104 early_param("nosmt", early_nosmt);
106 static int __init early_smt(char *s)
108 get_option(&s, &smp_max_threads);
111 early_param("smt", early_smt);
114 * The smp_cpu_state_mutex must be held when changing the state or polarization
115 * member of a pcpu data structure within the pcpu_devices arreay.
117 DEFINE_MUTEX(smp_cpu_state_mutex);
120 * Signal processor helper functions.
122 static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm)
127 cc = __pcpu_sigp(addr, order, parm, NULL);
128 if (cc != SIGP_CC_BUSY)
134 static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
138 for (retry = 0; ; retry++) {
139 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
140 if (cc != SIGP_CC_BUSY)
148 static inline int pcpu_stopped(struct pcpu *pcpu)
152 if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
153 0, &status) != SIGP_CC_STATUS_STORED)
155 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
158 static inline int pcpu_running(struct pcpu *pcpu)
160 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
161 0, NULL) != SIGP_CC_STATUS_STORED)
163 /* Status stored condition code is equivalent to cpu not running. */
168 * Find struct pcpu by cpu address.
170 static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address)
174 for_each_cpu(cpu, mask)
175 if (pcpu_devices[cpu].address == address)
176 return pcpu_devices + cpu;
180 static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
184 if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
186 order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
187 pcpu->ec_clk = get_tod_clock_fast();
188 pcpu_sigp_retry(pcpu, order, 0);
191 static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
193 unsigned long async_stack, nodat_stack, mcck_stack;
196 lc = (struct lowcore *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
197 nodat_stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
198 async_stack = stack_alloc();
199 mcck_stack = stack_alloc();
200 if (!lc || !nodat_stack || !async_stack || !mcck_stack)
202 memcpy(lc, &S390_lowcore, 512);
203 memset((char *) lc + 512, 0, sizeof(*lc) - 512);
204 lc->async_stack = async_stack + STACK_INIT_OFFSET;
205 lc->nodat_stack = nodat_stack + STACK_INIT_OFFSET;
206 lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;
208 lc->spinlock_lockval = arch_spin_lockval(cpu);
209 lc->spinlock_index = 0;
210 lc->br_r1_trampoline = 0x07f1; /* br %r1 */
211 lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
212 lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
213 lc->preempt_count = PREEMPT_DISABLED;
214 if (nmi_alloc_per_cpu(lc))
216 lowcore_ptr[cpu] = lc;
217 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
221 stack_free(mcck_stack);
222 stack_free(async_stack);
223 free_pages(nodat_stack, THREAD_SIZE_ORDER);
224 free_pages((unsigned long) lc, LC_ORDER);
228 static void pcpu_free_lowcore(struct pcpu *pcpu)
230 unsigned long async_stack, nodat_stack, mcck_stack;
234 cpu = pcpu - pcpu_devices;
235 lc = lowcore_ptr[cpu];
236 nodat_stack = lc->nodat_stack - STACK_INIT_OFFSET;
237 async_stack = lc->async_stack - STACK_INIT_OFFSET;
238 mcck_stack = lc->mcck_stack - STACK_INIT_OFFSET;
239 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
240 lowcore_ptr[cpu] = NULL;
241 nmi_free_per_cpu(lc);
242 stack_free(async_stack);
243 stack_free(mcck_stack);
244 free_pages(nodat_stack, THREAD_SIZE_ORDER);
245 free_pages((unsigned long) lc, LC_ORDER);
248 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
250 struct lowcore *lc = lowcore_ptr[cpu];
252 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
253 cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
255 lc->restart_flags = RESTART_FLAG_CTLREGS;
256 lc->spinlock_lockval = arch_spin_lockval(cpu);
257 lc->spinlock_index = 0;
258 lc->percpu_offset = __per_cpu_offset[cpu];
259 lc->kernel_asce = S390_lowcore.kernel_asce;
260 lc->user_asce = s390_invalid_asce;
261 lc->machine_flags = S390_lowcore.machine_flags;
262 lc->user_timer = lc->system_timer =
263 lc->steal_timer = lc->avg_steal_timer = 0;
264 __ctl_store(lc->cregs_save_area, 0, 15);
265 lc->cregs_save_area[1] = lc->kernel_asce;
266 lc->cregs_save_area[7] = lc->user_asce;
267 save_access_regs((unsigned int *) lc->access_regs_save_area);
268 arch_spin_lock_setup(cpu);
271 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
276 cpu = pcpu - pcpu_devices;
277 lc = lowcore_ptr[cpu];
278 lc->kernel_stack = (unsigned long) task_stack_page(tsk)
279 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
280 lc->current_task = (unsigned long) tsk;
282 lc->current_pid = tsk->pid;
283 lc->user_timer = tsk->thread.user_timer;
284 lc->guest_timer = tsk->thread.guest_timer;
285 lc->system_timer = tsk->thread.system_timer;
286 lc->hardirq_timer = tsk->thread.hardirq_timer;
287 lc->softirq_timer = tsk->thread.softirq_timer;
291 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
296 cpu = pcpu - pcpu_devices;
297 lc = lowcore_ptr[cpu];
298 lc->restart_stack = lc->kernel_stack;
299 lc->restart_fn = (unsigned long) func;
300 lc->restart_data = (unsigned long) data;
301 lc->restart_source = -1U;
302 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
305 typedef void (pcpu_delegate_fn)(void *);
308 * Call function via PSW restart on pcpu and stop the current cpu.
310 static void __pcpu_delegate(pcpu_delegate_fn *func, void *data)
312 func(data); /* should not return */
315 static void pcpu_delegate(struct pcpu *pcpu,
316 pcpu_delegate_fn *func,
317 void *data, unsigned long stack)
319 struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
320 unsigned int source_cpu = stap();
322 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
323 if (pcpu->address == source_cpu) {
324 call_on_stack(2, stack, void, __pcpu_delegate,
325 pcpu_delegate_fn *, func, void *, data);
327 /* Stop target cpu (if func returns this stops the current cpu). */
328 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
329 /* Restart func on the target cpu and stop the current cpu. */
330 mem_assign_absolute(lc->restart_stack, stack);
331 mem_assign_absolute(lc->restart_fn, (unsigned long) func);
332 mem_assign_absolute(lc->restart_data, (unsigned long) data);
333 mem_assign_absolute(lc->restart_source, source_cpu);
336 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
337 " brc 2,0b # busy, try again\n"
338 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
339 " brc 2,1b # busy, try again\n"
340 : : "d" (pcpu->address), "d" (source_cpu),
341 "K" (SIGP_RESTART), "K" (SIGP_STOP)
347 * Enable additional logical cpus for multi-threading.
349 static int pcpu_set_smt(unsigned int mtid)
353 if (smp_cpu_mtid == mtid)
355 cc = __pcpu_sigp(0, SIGP_SET_MULTI_THREADING, mtid, NULL);
358 smp_cpu_mt_shift = 0;
359 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift))
361 pcpu_devices[0].address = stap();
367 * Call function on an online CPU.
369 void smp_call_online_cpu(void (*func)(void *), void *data)
373 /* Use the current cpu if it is online. */
374 pcpu = pcpu_find_address(cpu_online_mask, stap());
376 /* Use the first online cpu. */
377 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
378 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
382 * Call function on the ipl CPU.
384 void smp_call_ipl_cpu(void (*func)(void *), void *data)
386 struct lowcore *lc = lowcore_ptr[0];
388 if (pcpu_devices[0].address == stap())
391 pcpu_delegate(&pcpu_devices[0], func, data,
395 int smp_find_processor_id(u16 address)
399 for_each_present_cpu(cpu)
400 if (pcpu_devices[cpu].address == address)
405 void schedule_mcck_handler(void)
407 pcpu_ec_call(pcpu_devices + smp_processor_id(), ec_mcck_pending);
410 bool notrace arch_vcpu_is_preempted(int cpu)
412 if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu))
414 if (pcpu_running(pcpu_devices + cpu))
418 EXPORT_SYMBOL(arch_vcpu_is_preempted);
420 void notrace smp_yield_cpu(int cpu)
422 if (!MACHINE_HAS_DIAG9C)
424 diag_stat_inc_norecursion(DIAG_STAT_X09C);
425 asm volatile("diag %0,0,0x9c"
426 : : "d" (pcpu_devices[cpu].address));
428 EXPORT_SYMBOL_GPL(smp_yield_cpu);
431 * Send cpus emergency shutdown signal. This gives the cpus the
432 * opportunity to complete outstanding interrupts.
434 void notrace smp_emergency_stop(void)
436 static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED;
437 static cpumask_t cpumask;
441 arch_spin_lock(&lock);
442 cpumask_copy(&cpumask, cpu_online_mask);
443 cpumask_clear_cpu(smp_processor_id(), &cpumask);
445 end = get_tod_clock() + (1000000UL << 12);
446 for_each_cpu(cpu, &cpumask) {
447 struct pcpu *pcpu = pcpu_devices + cpu;
448 set_bit(ec_stop_cpu, &pcpu->ec_mask);
449 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
450 0, NULL) == SIGP_CC_BUSY &&
451 get_tod_clock() < end)
454 while (get_tod_clock() < end) {
455 for_each_cpu(cpu, &cpumask)
456 if (pcpu_stopped(pcpu_devices + cpu))
457 cpumask_clear_cpu(cpu, &cpumask);
458 if (cpumask_empty(&cpumask))
462 arch_spin_unlock(&lock);
464 NOKPROBE_SYMBOL(smp_emergency_stop);
467 * Stop all cpus but the current one.
469 void smp_send_stop(void)
473 /* Disable all interrupts/machine checks */
474 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
475 trace_hardirqs_off();
477 debug_set_critical();
479 if (oops_in_progress)
480 smp_emergency_stop();
482 /* stop all processors */
483 for_each_online_cpu(cpu) {
484 if (cpu == smp_processor_id())
486 pcpu_sigp_retry(pcpu_devices + cpu, SIGP_STOP, 0);
487 while (!pcpu_stopped(pcpu_devices + cpu))
493 * This is the main routine where commands issued by other
496 static void smp_handle_ext_call(void)
500 /* handle bit signal external calls */
501 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
502 if (test_bit(ec_stop_cpu, &bits))
504 if (test_bit(ec_schedule, &bits))
506 if (test_bit(ec_call_function_single, &bits))
507 generic_smp_call_function_single_interrupt();
508 if (test_bit(ec_mcck_pending, &bits))
509 __s390_handle_mcck();
510 if (test_bit(ec_irq_work, &bits))
514 static void do_ext_call_interrupt(struct ext_code ext_code,
515 unsigned int param32, unsigned long param64)
517 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
518 smp_handle_ext_call();
521 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
525 for_each_cpu(cpu, mask)
526 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
529 void arch_send_call_function_single_ipi(int cpu)
531 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
535 * this function sends a 'reschedule' IPI to another CPU.
536 * it goes straight through and wastes no time serializing
537 * anything. Worst case is that we lose a reschedule ...
539 void smp_send_reschedule(int cpu)
541 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
544 #ifdef CONFIG_IRQ_WORK
545 void arch_irq_work_raise(void)
547 pcpu_ec_call(pcpu_devices + smp_processor_id(), ec_irq_work);
552 * parameter area for the set/clear control bit callbacks
554 struct ec_creg_mask_parms {
556 unsigned long andval;
561 * callback for setting/clearing control bits
563 static void smp_ctl_bit_callback(void *info)
565 struct ec_creg_mask_parms *pp = info;
566 unsigned long cregs[16];
568 __ctl_store(cregs, 0, 15);
569 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
570 __ctl_load(cregs, 0, 15);
573 static DEFINE_SPINLOCK(ctl_lock);
574 static unsigned long ctlreg;
577 * Set a bit in a control register of all cpus
579 void smp_ctl_set_bit(int cr, int bit)
581 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
583 spin_lock(&ctl_lock);
584 memcpy_absolute(&ctlreg, &S390_lowcore.cregs_save_area[cr], sizeof(ctlreg));
585 __set_bit(bit, &ctlreg);
586 memcpy_absolute(&S390_lowcore.cregs_save_area[cr], &ctlreg, sizeof(ctlreg));
587 spin_unlock(&ctl_lock);
588 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
590 EXPORT_SYMBOL(smp_ctl_set_bit);
593 * Clear a bit in a control register of all cpus
595 void smp_ctl_clear_bit(int cr, int bit)
597 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
599 spin_lock(&ctl_lock);
600 memcpy_absolute(&ctlreg, &S390_lowcore.cregs_save_area[cr], sizeof(ctlreg));
601 __clear_bit(bit, &ctlreg);
602 memcpy_absolute(&S390_lowcore.cregs_save_area[cr], &ctlreg, sizeof(ctlreg));
603 spin_unlock(&ctl_lock);
604 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
606 EXPORT_SYMBOL(smp_ctl_clear_bit);
608 #ifdef CONFIG_CRASH_DUMP
610 int smp_store_status(int cpu)
616 pcpu = pcpu_devices + cpu;
617 lc = lowcore_ptr[cpu];
618 pa = __pa(&lc->floating_pt_save_area);
619 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS,
620 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
622 if (!MACHINE_HAS_VX && !MACHINE_HAS_GS)
624 pa = __pa(lc->mcesad & MCESA_ORIGIN_MASK);
626 pa |= lc->mcesad & MCESA_LC_MASK;
627 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
628 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
634 * Collect CPU state of the previous, crashed system.
635 * There are four cases:
636 * 1) standard zfcp/nvme dump
637 * condition: OLDMEM_BASE == NULL && is_ipl_type_dump() == true
638 * The state for all CPUs except the boot CPU needs to be collected
639 * with sigp stop-and-store-status. The boot CPU state is located in
640 * the absolute lowcore of the memory stored in the HSA. The zcore code
641 * will copy the boot CPU state from the HSA.
642 * 2) stand-alone kdump for SCSI/NVMe (zfcp/nvme dump with swapped memory)
643 * condition: OLDMEM_BASE != NULL && is_ipl_type_dump() == true
644 * The state for all CPUs except the boot CPU needs to be collected
645 * with sigp stop-and-store-status. The firmware or the boot-loader
646 * stored the registers of the boot CPU in the absolute lowcore in the
647 * memory of the old system.
648 * 3) kdump and the old kernel did not store the CPU state,
649 * or stand-alone kdump for DASD
650 * condition: OLDMEM_BASE != NULL && !is_kdump_kernel()
651 * The state for all CPUs except the boot CPU needs to be collected
652 * with sigp stop-and-store-status. The kexec code or the boot-loader
653 * stored the registers of the boot CPU in the memory of the old system.
654 * 4) kdump and the old kernel stored the CPU state
655 * condition: OLDMEM_BASE != NULL && is_kdump_kernel()
656 * This case does not exist for s390 anymore, setup_arch explicitly
657 * deactivates the elfcorehdr= kernel parameter
659 static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr,
660 bool is_boot_cpu, unsigned long page)
662 __vector128 *vxrs = (__vector128 *) page;
665 vxrs = boot_cpu_vector_save_area;
667 __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page);
668 save_area_add_vxrs(sa, vxrs);
671 static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr,
672 bool is_boot_cpu, unsigned long page)
674 void *regs = (void *) page;
677 copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512);
679 __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page);
680 save_area_add_regs(sa, regs);
683 void __init smp_save_dump_cpus(void)
685 int addr, boot_cpu_addr, max_cpu_addr;
686 struct save_area *sa;
690 if (!(oldmem_data.start || is_ipl_type_dump()))
691 /* No previous system present, normal boot. */
693 /* Allocate a page as dumping area for the store status sigps */
694 page = memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE, 0, 1UL << 31);
696 panic("ERROR: Failed to allocate %lx bytes below %lx\n",
697 PAGE_SIZE, 1UL << 31);
699 /* Set multi-threading state to the previous system. */
700 pcpu_set_smt(sclp.mtid_prev);
701 boot_cpu_addr = stap();
702 max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;
703 for (addr = 0; addr <= max_cpu_addr; addr++) {
704 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==
705 SIGP_CC_NOT_OPERATIONAL)
707 is_boot_cpu = (addr == boot_cpu_addr);
708 /* Allocate save area */
709 sa = save_area_alloc(is_boot_cpu);
711 panic("could not allocate memory for save area\n");
713 /* Get the vector registers */
714 smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page);
716 * For a zfcp/nvme dump OLDMEM_BASE == NULL and the registers
717 * of the boot CPU are stored in the HSA. To retrieve
718 * these registers an SCLP request is required which is
719 * done by drivers/s390/char/zcore.c:init_cpu_info()
721 if (!is_boot_cpu || oldmem_data.start)
722 /* Get the CPU registers */
723 smp_save_cpu_regs(sa, addr, is_boot_cpu, page);
725 memblock_free(page, PAGE_SIZE);
726 diag_amode31_ops.diag308_reset();
729 #endif /* CONFIG_CRASH_DUMP */
731 void smp_cpu_set_polarization(int cpu, int val)
733 pcpu_devices[cpu].polarization = val;
736 int smp_cpu_get_polarization(int cpu)
738 return pcpu_devices[cpu].polarization;
741 int smp_cpu_get_cpu_address(int cpu)
743 return pcpu_devices[cpu].address;
746 static void __ref smp_get_core_info(struct sclp_core_info *info, int early)
748 static int use_sigp_detection;
751 if (use_sigp_detection || sclp_get_core_info(info, early)) {
752 use_sigp_detection = 1;
754 address < (SCLP_MAX_CORES << smp_cpu_mt_shift);
755 address += (1U << smp_cpu_mt_shift)) {
756 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) ==
757 SIGP_CC_NOT_OPERATIONAL)
759 info->core[info->configured].core_id =
760 address >> smp_cpu_mt_shift;
763 info->combined = info->configured;
767 static int smp_add_present_cpu(int cpu);
769 static int smp_add_core(struct sclp_core_entry *core, cpumask_t *avail,
770 bool configured, bool early)
777 if (sclp.has_core_type && core->type != boot_core_type)
779 cpu = cpumask_first(avail);
780 address = core->core_id << smp_cpu_mt_shift;
781 for (i = 0; (i <= smp_cpu_mtid) && (cpu < nr_cpu_ids); i++) {
782 if (pcpu_find_address(cpu_present_mask, address + i))
784 pcpu = pcpu_devices + cpu;
785 pcpu->address = address + i;
787 pcpu->state = CPU_STATE_CONFIGURED;
789 pcpu->state = CPU_STATE_STANDBY;
790 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
791 set_cpu_present(cpu, true);
792 if (!early && smp_add_present_cpu(cpu) != 0)
793 set_cpu_present(cpu, false);
796 cpumask_clear_cpu(cpu, avail);
797 cpu = cpumask_next(cpu, avail);
802 static int __smp_rescan_cpus(struct sclp_core_info *info, bool early)
804 struct sclp_core_entry *core;
805 static cpumask_t avail;
811 mutex_lock(&smp_cpu_state_mutex);
813 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
815 * Add IPL core first (which got logical CPU number 0) to make sure
816 * that all SMT threads get subsequent logical CPU numbers.
819 core_id = pcpu_devices[0].address >> smp_cpu_mt_shift;
820 for (i = 0; i < info->configured; i++) {
821 core = &info->core[i];
822 if (core->core_id == core_id) {
823 nr += smp_add_core(core, &avail, true, early);
828 for (i = 0; i < info->combined; i++) {
829 configured = i < info->configured;
830 nr += smp_add_core(&info->core[i], &avail, configured, early);
832 mutex_unlock(&smp_cpu_state_mutex);
837 void __init smp_detect_cpus(void)
839 unsigned int cpu, mtid, c_cpus, s_cpus;
840 struct sclp_core_info *info;
843 /* Get CPU information */
844 info = memblock_alloc(sizeof(*info), 8);
846 panic("%s: Failed to allocate %zu bytes align=0x%x\n",
847 __func__, sizeof(*info), 8);
848 smp_get_core_info(info, 1);
849 /* Find boot CPU type */
850 if (sclp.has_core_type) {
852 for (cpu = 0; cpu < info->combined; cpu++)
853 if (info->core[cpu].core_id == address) {
854 /* The boot cpu dictates the cpu type. */
855 boot_core_type = info->core[cpu].type;
858 if (cpu >= info->combined)
859 panic("Could not find boot CPU type");
862 /* Set multi-threading state for the current system */
863 mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp;
864 mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1;
867 /* Print number of CPUs */
869 for (cpu = 0; cpu < info->combined; cpu++) {
870 if (sclp.has_core_type &&
871 info->core[cpu].type != boot_core_type)
873 if (cpu < info->configured)
874 c_cpus += smp_cpu_mtid + 1;
876 s_cpus += smp_cpu_mtid + 1;
878 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
880 /* Add CPUs present at boot */
881 __smp_rescan_cpus(info, true);
882 memblock_free_early((unsigned long)info, sizeof(*info));
886 * Activate a secondary processor.
888 static void smp_start_secondary(void *cpuvoid)
890 int cpu = raw_smp_processor_id();
892 S390_lowcore.last_update_clock = get_tod_clock();
893 S390_lowcore.restart_stack = (unsigned long)restart_stack;
894 S390_lowcore.restart_fn = (unsigned long)do_restart;
895 S390_lowcore.restart_data = 0;
896 S390_lowcore.restart_source = -1U;
897 S390_lowcore.restart_flags = 0;
898 restore_access_regs(S390_lowcore.access_regs_save_area);
900 rcu_cpu_starting(cpu);
905 notify_cpu_starting(cpu);
906 if (topology_cpu_dedicated(cpu))
907 set_cpu_flag(CIF_DEDICATED_CPU);
909 clear_cpu_flag(CIF_DEDICATED_CPU);
910 set_cpu_online(cpu, true);
912 inc_irq_stat(CPU_RST);
914 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
917 /* Upping and downing of CPUs */
918 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
920 struct pcpu *pcpu = pcpu_devices + cpu;
923 if (pcpu->state != CPU_STATE_CONFIGURED)
925 if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) !=
926 SIGP_CC_ORDER_CODE_ACCEPTED)
929 rc = pcpu_alloc_lowcore(pcpu, cpu);
932 pcpu_prepare_secondary(pcpu, cpu);
933 pcpu_attach_task(pcpu, tidle);
934 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
935 /* Wait until cpu puts itself in the online & active maps */
936 while (!cpu_online(cpu))
941 static unsigned int setup_possible_cpus __initdata;
943 static int __init _setup_possible_cpus(char *s)
945 get_option(&s, &setup_possible_cpus);
948 early_param("possible_cpus", _setup_possible_cpus);
950 int __cpu_disable(void)
952 unsigned long cregs[16];
954 /* Handle possible pending IPIs */
955 smp_handle_ext_call();
956 set_cpu_online(smp_processor_id(), false);
958 /* Disable pseudo page faults on this cpu. */
960 /* Disable interrupt sources via control register. */
961 __ctl_store(cregs, 0, 15);
962 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
963 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
964 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
965 __ctl_load(cregs, 0, 15);
966 clear_cpu_flag(CIF_NOHZ_DELAY);
970 void __cpu_die(unsigned int cpu)
974 /* Wait until target cpu is down */
975 pcpu = pcpu_devices + cpu;
976 while (!pcpu_stopped(pcpu))
978 pcpu_free_lowcore(pcpu);
979 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
980 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
983 void __noreturn cpu_die(void)
987 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
991 void __init smp_fill_possible_mask(void)
993 unsigned int possible, sclp_max, cpu;
995 sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1;
996 sclp_max = min(smp_max_threads, sclp_max);
997 sclp_max = (sclp.max_cores * sclp_max) ?: nr_cpu_ids;
998 possible = setup_possible_cpus ?: nr_cpu_ids;
999 possible = min(possible, sclp_max);
1000 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
1001 set_cpu_possible(cpu, true);
1004 void __init smp_prepare_cpus(unsigned int max_cpus)
1006 /* request the 0x1201 emergency signal external interrupt */
1007 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
1008 panic("Couldn't request external interrupt 0x1201");
1009 /* request the 0x1202 external call external interrupt */
1010 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
1011 panic("Couldn't request external interrupt 0x1202");
1014 void __init smp_prepare_boot_cpu(void)
1016 struct pcpu *pcpu = pcpu_devices;
1018 WARN_ON(!cpu_present(0) || !cpu_online(0));
1019 pcpu->state = CPU_STATE_CONFIGURED;
1020 S390_lowcore.percpu_offset = __per_cpu_offset[0];
1021 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
1024 void __init smp_setup_processor_id(void)
1026 pcpu_devices[0].address = stap();
1027 S390_lowcore.cpu_nr = 0;
1028 S390_lowcore.spinlock_lockval = arch_spin_lockval(0);
1029 S390_lowcore.spinlock_index = 0;
1033 * the frequency of the profiling timer can be changed
1034 * by writing a multiplier value into /proc/profile.
1036 * usually you want to run this on all CPUs ;)
1038 int setup_profiling_timer(unsigned int multiplier)
1043 static ssize_t cpu_configure_show(struct device *dev,
1044 struct device_attribute *attr, char *buf)
1048 mutex_lock(&smp_cpu_state_mutex);
1049 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
1050 mutex_unlock(&smp_cpu_state_mutex);
1054 static ssize_t cpu_configure_store(struct device *dev,
1055 struct device_attribute *attr,
1056 const char *buf, size_t count)
1059 int cpu, val, rc, i;
1062 if (sscanf(buf, "%d %c", &val, &delim) != 1)
1064 if (val != 0 && val != 1)
1067 mutex_lock(&smp_cpu_state_mutex);
1069 /* disallow configuration changes of online cpus and cpu 0 */
1071 cpu = smp_get_base_cpu(cpu);
1074 for (i = 0; i <= smp_cpu_mtid; i++)
1075 if (cpu_online(cpu + i))
1077 pcpu = pcpu_devices + cpu;
1081 if (pcpu->state != CPU_STATE_CONFIGURED)
1083 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift);
1086 for (i = 0; i <= smp_cpu_mtid; i++) {
1087 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1089 pcpu[i].state = CPU_STATE_STANDBY;
1090 smp_cpu_set_polarization(cpu + i,
1091 POLARIZATION_UNKNOWN);
1093 topology_expect_change();
1096 if (pcpu->state != CPU_STATE_STANDBY)
1098 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift);
1101 for (i = 0; i <= smp_cpu_mtid; i++) {
1102 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1104 pcpu[i].state = CPU_STATE_CONFIGURED;
1105 smp_cpu_set_polarization(cpu + i,
1106 POLARIZATION_UNKNOWN);
1108 topology_expect_change();
1114 mutex_unlock(&smp_cpu_state_mutex);
1116 return rc ? rc : count;
1118 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
1120 static ssize_t show_cpu_address(struct device *dev,
1121 struct device_attribute *attr, char *buf)
1123 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
1125 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
1127 static struct attribute *cpu_common_attrs[] = {
1128 &dev_attr_configure.attr,
1129 &dev_attr_address.attr,
1133 static struct attribute_group cpu_common_attr_group = {
1134 .attrs = cpu_common_attrs,
1137 static struct attribute *cpu_online_attrs[] = {
1138 &dev_attr_idle_count.attr,
1139 &dev_attr_idle_time_us.attr,
1143 static struct attribute_group cpu_online_attr_group = {
1144 .attrs = cpu_online_attrs,
1147 static int smp_cpu_online(unsigned int cpu)
1149 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1151 return sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1154 static int smp_cpu_pre_down(unsigned int cpu)
1156 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1158 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1162 static int smp_add_present_cpu(int cpu)
1168 c = kzalloc(sizeof(*c), GFP_KERNEL);
1171 per_cpu(cpu_device, cpu) = c;
1173 c->hotpluggable = 1;
1174 rc = register_cpu(c, cpu);
1177 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1180 rc = topology_cpu_init(c);
1186 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1193 int __ref smp_rescan_cpus(void)
1195 struct sclp_core_info *info;
1198 info = kzalloc(sizeof(*info), GFP_KERNEL);
1201 smp_get_core_info(info, 0);
1202 nr = __smp_rescan_cpus(info, false);
1205 topology_schedule_update();
1209 static ssize_t __ref rescan_store(struct device *dev,
1210 struct device_attribute *attr,
1216 rc = lock_device_hotplug_sysfs();
1219 rc = smp_rescan_cpus();
1220 unlock_device_hotplug();
1221 return rc ? rc : count;
1223 static DEVICE_ATTR_WO(rescan);
1225 static int __init s390_smp_init(void)
1229 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1232 for_each_present_cpu(cpu) {
1233 rc = smp_add_present_cpu(cpu);
1238 rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "s390/smp:online",
1239 smp_cpu_online, smp_cpu_pre_down);
1240 rc = rc <= 0 ? rc : 0;
1244 subsys_initcall(s390_smp_init);
1246 static __always_inline void set_new_lowcore(struct lowcore *lc)
1248 union register_pair dst, src;
1251 src.even = (unsigned long) &S390_lowcore;
1252 src.odd = sizeof(S390_lowcore);
1253 dst.even = (unsigned long) lc;
1254 dst.odd = sizeof(*lc);
1255 pfx = (unsigned long) lc;
1258 " mvcl %[dst],%[src]\n"
1260 : [dst] "+&d" (dst.pair), [src] "+&d" (src.pair)
1265 static int __init smp_reinit_ipl_cpu(void)
1267 unsigned long async_stack, nodat_stack, mcck_stack;
1268 struct lowcore *lc, *lc_ipl;
1269 unsigned long flags;
1271 lc_ipl = lowcore_ptr[0];
1272 lc = (struct lowcore *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
1273 nodat_stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
1274 async_stack = stack_alloc();
1275 mcck_stack = stack_alloc();
1276 if (!lc || !nodat_stack || !async_stack || !mcck_stack)
1277 panic("Couldn't allocate memory");
1279 local_irq_save(flags);
1280 local_mcck_disable();
1281 set_new_lowcore(lc);
1282 S390_lowcore.nodat_stack = nodat_stack + STACK_INIT_OFFSET;
1283 S390_lowcore.async_stack = async_stack + STACK_INIT_OFFSET;
1284 S390_lowcore.mcck_stack = mcck_stack + STACK_INIT_OFFSET;
1285 lowcore_ptr[0] = lc;
1286 local_mcck_enable();
1287 local_irq_restore(flags);
1289 free_pages(lc_ipl->async_stack - STACK_INIT_OFFSET, THREAD_SIZE_ORDER);
1290 memblock_free_late(lc_ipl->mcck_stack - STACK_INIT_OFFSET, THREAD_SIZE);
1291 memblock_free_late((unsigned long) lc_ipl, sizeof(*lc_ipl));
1295 early_initcall(smp_reinit_ipl_cpu);