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/bootmem.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/memblock.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>
52 #include <asm/debug.h>
53 #include <asm/os_info.h>
57 #include <asm/topology.h>
62 ec_call_function_single,
71 static DEFINE_PER_CPU(struct cpu *, cpu_device);
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 */
82 static u8 boot_core_type;
83 static struct pcpu pcpu_devices[NR_CPUS];
85 unsigned int smp_cpu_mt_shift;
86 EXPORT_SYMBOL(smp_cpu_mt_shift);
88 unsigned int smp_cpu_mtid;
89 EXPORT_SYMBOL(smp_cpu_mtid);
91 #ifdef CONFIG_CRASH_DUMP
92 __vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
95 static unsigned int smp_max_threads __initdata = -1U;
97 static int __init early_nosmt(char *s)
102 early_param("nosmt", early_nosmt);
104 static int __init early_smt(char *s)
106 get_option(&s, &smp_max_threads);
109 early_param("smt", early_smt);
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.
115 DEFINE_MUTEX(smp_cpu_state_mutex);
118 * Signal processor helper functions.
120 static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm)
125 cc = __pcpu_sigp(addr, order, parm, NULL);
126 if (cc != SIGP_CC_BUSY)
132 static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
136 for (retry = 0; ; retry++) {
137 cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
138 if (cc != SIGP_CC_BUSY)
146 static inline int pcpu_stopped(struct pcpu *pcpu)
148 u32 uninitialized_var(status);
150 if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
151 0, &status) != SIGP_CC_STATUS_STORED)
153 return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
156 static inline int pcpu_running(struct pcpu *pcpu)
158 if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
159 0, NULL) != SIGP_CC_STATUS_STORED)
161 /* Status stored condition code is equivalent to cpu not running. */
166 * Find struct pcpu by cpu address.
168 static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address)
172 for_each_cpu(cpu, mask)
173 if (pcpu_devices[cpu].address == address)
174 return pcpu_devices + cpu;
178 static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
182 if (test_and_set_bit(ec_bit, &pcpu->ec_mask))
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);
189 static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
191 unsigned long async_stack, nodat_stack;
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)
201 nodat_stack = pcpu->lowcore->nodat_stack - STACK_INIT_OFFSET;
203 async_stack = stack_alloc();
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;
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))
217 if (vdso_alloc_per_cpu(lc))
219 lowcore_ptr[cpu] = lc;
220 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
224 nmi_free_per_cpu(lc);
226 stack_free(async_stack);
228 if (pcpu != &pcpu_devices[0]) {
229 free_pages(nodat_stack, THREAD_SIZE_ORDER);
230 free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
235 #ifdef CONFIG_HOTPLUG_CPU
237 static void pcpu_free_lowcore(struct pcpu *pcpu)
239 unsigned long async_stack, nodat_stack, lowcore;
241 nodat_stack = pcpu->lowcore->nodat_stack - STACK_INIT_OFFSET;
242 async_stack = pcpu->lowcore->async_stack - STACK_INIT_OFFSET;
243 lowcore = (unsigned long) pcpu->lowcore;
245 pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
246 lowcore_ptr[pcpu - pcpu_devices] = NULL;
247 vdso_free_per_cpu(pcpu->lowcore);
248 nmi_free_per_cpu(pcpu->lowcore);
249 stack_free(async_stack);
250 if (pcpu == &pcpu_devices[0])
252 free_pages(nodat_stack, THREAD_SIZE_ORDER);
253 free_pages(lowcore, LC_ORDER);
256 #endif /* CONFIG_HOTPLUG_CPU */
258 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
260 struct lowcore *lc = pcpu->lowcore;
262 cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
263 cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
265 lc->spinlock_lockval = arch_spin_lockval(cpu);
266 lc->spinlock_index = 0;
267 lc->percpu_offset = __per_cpu_offset[cpu];
268 lc->kernel_asce = S390_lowcore.kernel_asce;
269 lc->machine_flags = S390_lowcore.machine_flags;
270 lc->user_timer = lc->system_timer = lc->steal_timer = 0;
271 __ctl_store(lc->cregs_save_area, 0, 15);
272 save_access_regs((unsigned int *) lc->access_regs_save_area);
273 memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
274 sizeof(lc->stfle_fac_list));
275 memcpy(lc->alt_stfle_fac_list, S390_lowcore.alt_stfle_fac_list,
276 sizeof(lc->alt_stfle_fac_list));
277 arch_spin_lock_setup(cpu);
280 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
282 struct lowcore *lc = pcpu->lowcore;
284 lc->kernel_stack = (unsigned long) task_stack_page(tsk)
285 + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
286 lc->current_task = (unsigned long) tsk;
288 lc->current_pid = tsk->pid;
289 lc->user_timer = tsk->thread.user_timer;
290 lc->guest_timer = tsk->thread.guest_timer;
291 lc->system_timer = tsk->thread.system_timer;
292 lc->hardirq_timer = tsk->thread.hardirq_timer;
293 lc->softirq_timer = tsk->thread.softirq_timer;
297 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
299 struct lowcore *lc = pcpu->lowcore;
301 lc->restart_stack = lc->nodat_stack;
302 lc->restart_fn = (unsigned long) func;
303 lc->restart_data = (unsigned long) data;
304 lc->restart_source = -1UL;
305 pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
309 * Call function via PSW restart on pcpu and stop the current cpu.
311 static void __pcpu_delegate(void (*func)(void*), void *data)
313 func(data); /* should not return */
316 static void __no_sanitize_address pcpu_delegate(struct pcpu *pcpu,
317 void (*func)(void *),
318 void *data, unsigned long stack)
320 struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
321 unsigned long source_cpu = stap();
323 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
324 if (pcpu->address == source_cpu)
325 CALL_ON_STACK(__pcpu_delegate, stack, 2, func, data);
326 /* Stop target cpu (if func returns this stops the current cpu). */
327 pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
328 /* Restart func on the target cpu and stop the current cpu. */
329 mem_assign_absolute(lc->restart_stack, stack);
330 mem_assign_absolute(lc->restart_fn, (unsigned long) func);
331 mem_assign_absolute(lc->restart_data, (unsigned long) data);
332 mem_assign_absolute(lc->restart_source, source_cpu);
335 "0: sigp 0,%0,%2 # sigp restart to target cpu\n"
336 " brc 2,0b # busy, try again\n"
337 "1: sigp 0,%1,%3 # sigp stop to current cpu\n"
338 " brc 2,1b # busy, try again\n"
339 : : "d" (pcpu->address), "d" (source_cpu),
340 "K" (SIGP_RESTART), "K" (SIGP_STOP)
346 * Enable additional logical cpus for multi-threading.
348 static int pcpu_set_smt(unsigned int mtid)
352 if (smp_cpu_mtid == mtid)
354 cc = __pcpu_sigp(0, SIGP_SET_MULTI_THREADING, mtid, NULL);
357 smp_cpu_mt_shift = 0;
358 while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift))
360 pcpu_devices[0].address = stap();
366 * Call function on an online CPU.
368 void smp_call_online_cpu(void (*func)(void *), void *data)
372 /* Use the current cpu if it is online. */
373 pcpu = pcpu_find_address(cpu_online_mask, stap());
375 /* Use the first online cpu. */
376 pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
377 pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
381 * Call function on the ipl CPU.
383 void smp_call_ipl_cpu(void (*func)(void *), void *data)
385 pcpu_delegate(&pcpu_devices[0], func, data,
386 pcpu_devices->lowcore->nodat_stack);
389 int smp_find_processor_id(u16 address)
393 for_each_present_cpu(cpu)
394 if (pcpu_devices[cpu].address == address)
399 bool arch_vcpu_is_preempted(int cpu)
401 if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu))
403 if (pcpu_running(pcpu_devices + cpu))
407 EXPORT_SYMBOL(arch_vcpu_is_preempted);
409 void smp_yield_cpu(int cpu)
411 if (MACHINE_HAS_DIAG9C) {
412 diag_stat_inc_norecursion(DIAG_STAT_X09C);
413 asm volatile("diag %0,0,0x9c"
414 : : "d" (pcpu_devices[cpu].address));
415 } else if (MACHINE_HAS_DIAG44) {
416 diag_stat_inc_norecursion(DIAG_STAT_X044);
417 asm volatile("diag 0,0,0x44");
422 * Send cpus emergency shutdown signal. This gives the cpus the
423 * opportunity to complete outstanding interrupts.
425 void notrace smp_emergency_stop(void)
431 cpumask_copy(&cpumask, cpu_online_mask);
432 cpumask_clear_cpu(smp_processor_id(), &cpumask);
434 end = get_tod_clock() + (1000000UL << 12);
435 for_each_cpu(cpu, &cpumask) {
436 struct pcpu *pcpu = pcpu_devices + cpu;
437 set_bit(ec_stop_cpu, &pcpu->ec_mask);
438 while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
439 0, NULL) == SIGP_CC_BUSY &&
440 get_tod_clock() < end)
443 while (get_tod_clock() < end) {
444 for_each_cpu(cpu, &cpumask)
445 if (pcpu_stopped(pcpu_devices + cpu))
446 cpumask_clear_cpu(cpu, &cpumask);
447 if (cpumask_empty(&cpumask))
452 NOKPROBE_SYMBOL(smp_emergency_stop);
455 * Stop all cpus but the current one.
457 void smp_send_stop(void)
461 /* Disable all interrupts/machine checks */
462 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
463 trace_hardirqs_off();
465 debug_set_critical();
467 if (oops_in_progress)
468 smp_emergency_stop();
470 /* stop all processors */
471 for_each_online_cpu(cpu) {
472 if (cpu == smp_processor_id())
474 pcpu_sigp_retry(pcpu_devices + cpu, SIGP_STOP, 0);
475 while (!pcpu_stopped(pcpu_devices + cpu))
481 * This is the main routine where commands issued by other
484 static void smp_handle_ext_call(void)
488 /* handle bit signal external calls */
489 bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
490 if (test_bit(ec_stop_cpu, &bits))
492 if (test_bit(ec_schedule, &bits))
494 if (test_bit(ec_call_function_single, &bits))
495 generic_smp_call_function_single_interrupt();
498 static void do_ext_call_interrupt(struct ext_code ext_code,
499 unsigned int param32, unsigned long param64)
501 inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
502 smp_handle_ext_call();
505 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
509 for_each_cpu(cpu, mask)
510 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
513 void arch_send_call_function_single_ipi(int cpu)
515 pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
519 * this function sends a 'reschedule' IPI to another CPU.
520 * it goes straight through and wastes no time serializing
521 * anything. Worst case is that we lose a reschedule ...
523 void smp_send_reschedule(int cpu)
525 pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
529 * parameter area for the set/clear control bit callbacks
531 struct ec_creg_mask_parms {
533 unsigned long andval;
538 * callback for setting/clearing control bits
540 static void smp_ctl_bit_callback(void *info)
542 struct ec_creg_mask_parms *pp = info;
543 unsigned long cregs[16];
545 __ctl_store(cregs, 0, 15);
546 cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
547 __ctl_load(cregs, 0, 15);
551 * Set a bit in a control register of all cpus
553 void smp_ctl_set_bit(int cr, int bit)
555 struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
557 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
559 EXPORT_SYMBOL(smp_ctl_set_bit);
562 * Clear a bit in a control register of all cpus
564 void smp_ctl_clear_bit(int cr, int bit)
566 struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
568 on_each_cpu(smp_ctl_bit_callback, &parms, 1);
570 EXPORT_SYMBOL(smp_ctl_clear_bit);
572 #ifdef CONFIG_CRASH_DUMP
574 int smp_store_status(int cpu)
576 struct pcpu *pcpu = pcpu_devices + cpu;
579 pa = __pa(&pcpu->lowcore->floating_pt_save_area);
580 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS,
581 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
583 if (!MACHINE_HAS_VX && !MACHINE_HAS_GS)
585 pa = __pa(pcpu->lowcore->mcesad & MCESA_ORIGIN_MASK);
587 pa |= pcpu->lowcore->mcesad & MCESA_LC_MASK;
588 if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
589 pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
595 * Collect CPU state of the previous, crashed system.
596 * There are four cases:
597 * 1) standard zfcp dump
598 * condition: OLDMEM_BASE == NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
599 * The state for all CPUs except the boot CPU needs to be collected
600 * with sigp stop-and-store-status. The boot CPU state is located in
601 * the absolute lowcore of the memory stored in the HSA. The zcore code
602 * will copy the boot CPU state from the HSA.
603 * 2) stand-alone kdump for SCSI (zfcp dump with swapped memory)
604 * condition: OLDMEM_BASE != NULL && ipl_info.type == IPL_TYPE_FCP_DUMP
605 * The state for all CPUs except the boot CPU needs to be collected
606 * with sigp stop-and-store-status. The firmware or the boot-loader
607 * stored the registers of the boot CPU in the absolute lowcore in the
608 * memory of the old system.
609 * 3) kdump and the old kernel did not store the CPU state,
610 * or stand-alone kdump for DASD
611 * condition: OLDMEM_BASE != NULL && !is_kdump_kernel()
612 * The state for all CPUs except the boot CPU needs to be collected
613 * with sigp stop-and-store-status. The kexec code or the boot-loader
614 * stored the registers of the boot CPU in the memory of the old system.
615 * 4) kdump and the old kernel stored the CPU state
616 * condition: OLDMEM_BASE != NULL && is_kdump_kernel()
617 * This case does not exist for s390 anymore, setup_arch explicitly
618 * deactivates the elfcorehdr= kernel parameter
620 static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr,
621 bool is_boot_cpu, unsigned long page)
623 __vector128 *vxrs = (__vector128 *) page;
626 vxrs = boot_cpu_vector_save_area;
628 __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page);
629 save_area_add_vxrs(sa, vxrs);
632 static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr,
633 bool is_boot_cpu, unsigned long page)
635 void *regs = (void *) page;
638 copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512);
640 __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page);
641 save_area_add_regs(sa, regs);
644 void __init smp_save_dump_cpus(void)
646 int addr, boot_cpu_addr, max_cpu_addr;
647 struct save_area *sa;
651 if (!(OLDMEM_BASE || ipl_info.type == IPL_TYPE_FCP_DUMP))
652 /* No previous system present, normal boot. */
654 /* Allocate a page as dumping area for the store status sigps */
655 page = memblock_alloc_base(PAGE_SIZE, PAGE_SIZE, 1UL << 31);
656 /* Set multi-threading state to the previous system. */
657 pcpu_set_smt(sclp.mtid_prev);
658 boot_cpu_addr = stap();
659 max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;
660 for (addr = 0; addr <= max_cpu_addr; addr++) {
661 if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==
662 SIGP_CC_NOT_OPERATIONAL)
664 is_boot_cpu = (addr == boot_cpu_addr);
665 /* Allocate save area */
666 sa = save_area_alloc(is_boot_cpu);
668 panic("could not allocate memory for save area\n");
670 /* Get the vector registers */
671 smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page);
673 * For a zfcp dump OLDMEM_BASE == NULL and the registers
674 * of the boot CPU are stored in the HSA. To retrieve
675 * these registers an SCLP request is required which is
676 * done by drivers/s390/char/zcore.c:init_cpu_info()
678 if (!is_boot_cpu || OLDMEM_BASE)
679 /* Get the CPU registers */
680 smp_save_cpu_regs(sa, addr, is_boot_cpu, page);
682 memblock_free(page, PAGE_SIZE);
686 #endif /* CONFIG_CRASH_DUMP */
688 void smp_cpu_set_polarization(int cpu, int val)
690 pcpu_devices[cpu].polarization = val;
693 int smp_cpu_get_polarization(int cpu)
695 return pcpu_devices[cpu].polarization;
698 static void __ref smp_get_core_info(struct sclp_core_info *info, int early)
700 static int use_sigp_detection;
703 if (use_sigp_detection || sclp_get_core_info(info, early)) {
704 use_sigp_detection = 1;
706 address < (SCLP_MAX_CORES << smp_cpu_mt_shift);
707 address += (1U << smp_cpu_mt_shift)) {
708 if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) ==
709 SIGP_CC_NOT_OPERATIONAL)
711 info->core[info->configured].core_id =
712 address >> smp_cpu_mt_shift;
715 info->combined = info->configured;
719 static int smp_add_present_cpu(int cpu);
721 static int __smp_rescan_cpus(struct sclp_core_info *info, int sysfs_add)
729 cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
730 cpu = cpumask_first(&avail);
731 for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) {
732 if (sclp.has_core_type && info->core[i].type != boot_core_type)
734 address = info->core[i].core_id << smp_cpu_mt_shift;
735 for (j = 0; j <= smp_cpu_mtid; j++) {
736 if (pcpu_find_address(cpu_present_mask, address + j))
738 pcpu = pcpu_devices + cpu;
739 pcpu->address = address + j;
741 (cpu >= info->configured*(smp_cpu_mtid + 1)) ?
742 CPU_STATE_STANDBY : CPU_STATE_CONFIGURED;
743 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
744 set_cpu_present(cpu, true);
745 if (sysfs_add && smp_add_present_cpu(cpu) != 0)
746 set_cpu_present(cpu, false);
749 cpu = cpumask_next(cpu, &avail);
750 if (cpu >= nr_cpu_ids)
757 void __init smp_detect_cpus(void)
759 unsigned int cpu, mtid, c_cpus, s_cpus;
760 struct sclp_core_info *info;
763 /* Get CPU information */
764 info = memblock_alloc(sizeof(*info), 8);
765 smp_get_core_info(info, 1);
766 /* Find boot CPU type */
767 if (sclp.has_core_type) {
769 for (cpu = 0; cpu < info->combined; cpu++)
770 if (info->core[cpu].core_id == address) {
771 /* The boot cpu dictates the cpu type. */
772 boot_core_type = info->core[cpu].type;
775 if (cpu >= info->combined)
776 panic("Could not find boot CPU type");
779 /* Set multi-threading state for the current system */
780 mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp;
781 mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1;
784 /* Print number of CPUs */
786 for (cpu = 0; cpu < info->combined; cpu++) {
787 if (sclp.has_core_type &&
788 info->core[cpu].type != boot_core_type)
790 if (cpu < info->configured)
791 c_cpus += smp_cpu_mtid + 1;
793 s_cpus += smp_cpu_mtid + 1;
795 pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
797 /* Add CPUs present at boot */
799 __smp_rescan_cpus(info, 0);
801 memblock_free_early((unsigned long)info, sizeof(*info));
804 static void smp_init_secondary(void)
806 int cpu = smp_processor_id();
808 S390_lowcore.last_update_clock = get_tod_clock();
809 restore_access_regs(S390_lowcore.access_regs_save_area);
815 notify_cpu_starting(smp_processor_id());
816 if (topology_cpu_dedicated(cpu))
817 set_cpu_flag(CIF_DEDICATED_CPU);
819 clear_cpu_flag(CIF_DEDICATED_CPU);
820 set_cpu_online(smp_processor_id(), true);
821 inc_irq_stat(CPU_RST);
823 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
827 * Activate a secondary processor.
829 static void __no_sanitize_address smp_start_secondary(void *cpuvoid)
831 S390_lowcore.restart_stack = (unsigned long) restart_stack;
832 S390_lowcore.restart_fn = (unsigned long) do_restart;
833 S390_lowcore.restart_data = 0;
834 S390_lowcore.restart_source = -1UL;
835 __ctl_load(S390_lowcore.cregs_save_area, 0, 15);
836 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
837 CALL_ON_STACK(smp_init_secondary, S390_lowcore.kernel_stack, 0);
840 /* Upping and downing of CPUs */
841 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
846 pcpu = pcpu_devices + cpu;
847 if (pcpu->state != CPU_STATE_CONFIGURED)
849 base = smp_get_base_cpu(cpu);
850 for (i = 0; i <= smp_cpu_mtid; i++) {
851 if (base + i < nr_cpu_ids)
852 if (cpu_online(base + i))
856 * If this is the first CPU of the core to get online
857 * do an initial CPU reset.
859 if (i > smp_cpu_mtid &&
860 pcpu_sigp_retry(pcpu_devices + base, SIGP_INITIAL_CPU_RESET, 0) !=
861 SIGP_CC_ORDER_CODE_ACCEPTED)
864 rc = pcpu_alloc_lowcore(pcpu, cpu);
867 pcpu_prepare_secondary(pcpu, cpu);
868 pcpu_attach_task(pcpu, tidle);
869 pcpu_start_fn(pcpu, smp_start_secondary, NULL);
870 /* Wait until cpu puts itself in the online & active maps */
871 while (!cpu_online(cpu))
876 static unsigned int setup_possible_cpus __initdata;
878 static int __init _setup_possible_cpus(char *s)
880 get_option(&s, &setup_possible_cpus);
883 early_param("possible_cpus", _setup_possible_cpus);
885 #ifdef CONFIG_HOTPLUG_CPU
887 int __cpu_disable(void)
889 unsigned long cregs[16];
891 /* Handle possible pending IPIs */
892 smp_handle_ext_call();
893 set_cpu_online(smp_processor_id(), false);
894 /* Disable pseudo page faults on this cpu. */
896 /* Disable interrupt sources via control register. */
897 __ctl_store(cregs, 0, 15);
898 cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */
899 cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */
900 cregs[14] &= ~0x1f000000UL; /* disable most machine checks */
901 __ctl_load(cregs, 0, 15);
902 clear_cpu_flag(CIF_NOHZ_DELAY);
906 void __cpu_die(unsigned int cpu)
910 /* Wait until target cpu is down */
911 pcpu = pcpu_devices + cpu;
912 while (!pcpu_stopped(pcpu))
914 pcpu_free_lowcore(pcpu);
915 cpumask_clear_cpu(cpu, mm_cpumask(&init_mm));
916 cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask);
919 void __noreturn cpu_die(void)
923 pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
927 #endif /* CONFIG_HOTPLUG_CPU */
929 void __init smp_fill_possible_mask(void)
931 unsigned int possible, sclp_max, cpu;
933 sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1;
934 sclp_max = min(smp_max_threads, sclp_max);
935 sclp_max = (sclp.max_cores * sclp_max) ?: nr_cpu_ids;
936 possible = setup_possible_cpus ?: nr_cpu_ids;
937 possible = min(possible, sclp_max);
938 for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++)
939 set_cpu_possible(cpu, true);
942 void __init smp_prepare_cpus(unsigned int max_cpus)
944 /* request the 0x1201 emergency signal external interrupt */
945 if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt))
946 panic("Couldn't request external interrupt 0x1201");
947 /* request the 0x1202 external call external interrupt */
948 if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt))
949 panic("Couldn't request external interrupt 0x1202");
952 void __init smp_prepare_boot_cpu(void)
954 struct pcpu *pcpu = pcpu_devices;
956 WARN_ON(!cpu_present(0) || !cpu_online(0));
957 pcpu->state = CPU_STATE_CONFIGURED;
958 pcpu->lowcore = (struct lowcore *)(unsigned long) store_prefix();
959 S390_lowcore.percpu_offset = __per_cpu_offset[0];
960 smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
963 void __init smp_cpus_done(unsigned int max_cpus)
967 void __init smp_setup_processor_id(void)
969 pcpu_devices[0].address = stap();
970 S390_lowcore.cpu_nr = 0;
971 S390_lowcore.spinlock_lockval = arch_spin_lockval(0);
972 S390_lowcore.spinlock_index = 0;
976 * the frequency of the profiling timer can be changed
977 * by writing a multiplier value into /proc/profile.
979 * usually you want to run this on all CPUs ;)
981 int setup_profiling_timer(unsigned int multiplier)
986 #ifdef CONFIG_HOTPLUG_CPU
987 static ssize_t cpu_configure_show(struct device *dev,
988 struct device_attribute *attr, char *buf)
992 mutex_lock(&smp_cpu_state_mutex);
993 count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
994 mutex_unlock(&smp_cpu_state_mutex);
998 static ssize_t cpu_configure_store(struct device *dev,
999 struct device_attribute *attr,
1000 const char *buf, size_t count)
1003 int cpu, val, rc, i;
1006 if (sscanf(buf, "%d %c", &val, &delim) != 1)
1008 if (val != 0 && val != 1)
1011 mutex_lock(&smp_cpu_state_mutex);
1013 /* disallow configuration changes of online cpus and cpu 0 */
1015 cpu = smp_get_base_cpu(cpu);
1018 for (i = 0; i <= smp_cpu_mtid; i++)
1019 if (cpu_online(cpu + i))
1021 pcpu = pcpu_devices + cpu;
1025 if (pcpu->state != CPU_STATE_CONFIGURED)
1027 rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift);
1030 for (i = 0; i <= smp_cpu_mtid; i++) {
1031 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1033 pcpu[i].state = CPU_STATE_STANDBY;
1034 smp_cpu_set_polarization(cpu + i,
1035 POLARIZATION_UNKNOWN);
1037 topology_expect_change();
1040 if (pcpu->state != CPU_STATE_STANDBY)
1042 rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift);
1045 for (i = 0; i <= smp_cpu_mtid; i++) {
1046 if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i))
1048 pcpu[i].state = CPU_STATE_CONFIGURED;
1049 smp_cpu_set_polarization(cpu + i,
1050 POLARIZATION_UNKNOWN);
1052 topology_expect_change();
1058 mutex_unlock(&smp_cpu_state_mutex);
1060 return rc ? rc : count;
1062 static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
1063 #endif /* CONFIG_HOTPLUG_CPU */
1065 static ssize_t show_cpu_address(struct device *dev,
1066 struct device_attribute *attr, char *buf)
1068 return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
1070 static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
1072 static struct attribute *cpu_common_attrs[] = {
1073 #ifdef CONFIG_HOTPLUG_CPU
1074 &dev_attr_configure.attr,
1076 &dev_attr_address.attr,
1080 static struct attribute_group cpu_common_attr_group = {
1081 .attrs = cpu_common_attrs,
1084 static struct attribute *cpu_online_attrs[] = {
1085 &dev_attr_idle_count.attr,
1086 &dev_attr_idle_time_us.attr,
1090 static struct attribute_group cpu_online_attr_group = {
1091 .attrs = cpu_online_attrs,
1094 static int smp_cpu_online(unsigned int cpu)
1096 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1098 return sysfs_create_group(&s->kobj, &cpu_online_attr_group);
1100 static int smp_cpu_pre_down(unsigned int cpu)
1102 struct device *s = &per_cpu(cpu_device, cpu)->dev;
1104 sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
1108 static int smp_add_present_cpu(int cpu)
1114 c = kzalloc(sizeof(*c), GFP_KERNEL);
1117 per_cpu(cpu_device, cpu) = c;
1119 c->hotpluggable = 1;
1120 rc = register_cpu(c, cpu);
1123 rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
1126 rc = topology_cpu_init(c);
1132 sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
1134 #ifdef CONFIG_HOTPLUG_CPU
1141 #ifdef CONFIG_HOTPLUG_CPU
1143 int __ref smp_rescan_cpus(void)
1145 struct sclp_core_info *info;
1148 info = kzalloc(sizeof(*info), GFP_KERNEL);
1151 smp_get_core_info(info, 0);
1153 mutex_lock(&smp_cpu_state_mutex);
1154 nr = __smp_rescan_cpus(info, 1);
1155 mutex_unlock(&smp_cpu_state_mutex);
1159 topology_schedule_update();
1163 static ssize_t __ref rescan_store(struct device *dev,
1164 struct device_attribute *attr,
1170 rc = smp_rescan_cpus();
1171 return rc ? rc : count;
1173 static DEVICE_ATTR_WO(rescan);
1174 #endif /* CONFIG_HOTPLUG_CPU */
1176 static int __init s390_smp_init(void)
1180 #ifdef CONFIG_HOTPLUG_CPU
1181 rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
1185 for_each_present_cpu(cpu) {
1186 rc = smp_add_present_cpu(cpu);
1191 rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "s390/smp:online",
1192 smp_cpu_online, smp_cpu_pre_down);
1193 rc = rc <= 0 ? rc : 0;
1197 subsys_initcall(s390_smp_init);