1 // SPDX-License-Identifier: GPL-2.0-only
3 * SMP initialisation and IPI support
4 * Based on arch/arm/kernel/smp.c
6 * Copyright (C) 2012 ARM Ltd.
9 #include <linux/acpi.h>
10 #include <linux/arm_sdei.h>
11 #include <linux/delay.h>
12 #include <linux/init.h>
13 #include <linux/spinlock.h>
14 #include <linux/sched/mm.h>
15 #include <linux/sched/hotplug.h>
16 #include <linux/sched/task_stack.h>
17 #include <linux/interrupt.h>
18 #include <linux/cache.h>
19 #include <linux/profile.h>
20 #include <linux/errno.h>
22 #include <linux/err.h>
23 #include <linux/cpu.h>
24 #include <linux/smp.h>
25 #include <linux/seq_file.h>
26 #include <linux/irq.h>
27 #include <linux/irqchip/arm-gic-v3.h>
28 #include <linux/percpu.h>
29 #include <linux/clockchips.h>
30 #include <linux/completion.h>
32 #include <linux/irq_work.h>
33 #include <linux/kernel_stat.h>
34 #include <linux/kexec.h>
35 #include <linux/kvm_host.h>
37 #include <asm/alternative.h>
38 #include <asm/atomic.h>
39 #include <asm/cacheflush.h>
41 #include <asm/cputype.h>
42 #include <asm/cpu_ops.h>
43 #include <asm/daifflags.h>
44 #include <asm/kvm_mmu.h>
45 #include <asm/mmu_context.h>
47 #include <asm/processor.h>
48 #include <asm/smp_plat.h>
49 #include <asm/sections.h>
50 #include <asm/tlbflush.h>
51 #include <asm/ptrace.h>
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/ipi.h>
57 DEFINE_PER_CPU_READ_MOSTLY(int, cpu_number);
58 EXPORT_PER_CPU_SYMBOL(cpu_number);
61 * as from 2.5, kernels no longer have an init_tasks structure
62 * so we need some other way of telling a new secondary core
63 * where to place its SVC stack
65 struct secondary_data secondary_data;
66 /* Number of CPUs which aren't online, but looping in kernel text. */
67 static int cpus_stuck_in_kernel;
80 static int ipi_irq_base __read_mostly;
81 static int nr_ipi __read_mostly = NR_IPI;
82 static struct irq_desc *ipi_desc[NR_IPI] __read_mostly;
84 static void ipi_setup(int cpu);
86 #ifdef CONFIG_HOTPLUG_CPU
87 static void ipi_teardown(int cpu);
88 static int op_cpu_kill(unsigned int cpu);
90 static inline int op_cpu_kill(unsigned int cpu)
98 * Boot a secondary CPU, and assign it the specified idle task.
99 * This also gives us the initial stack to use for this CPU.
101 static int boot_secondary(unsigned int cpu, struct task_struct *idle)
103 const struct cpu_operations *ops = get_cpu_ops(cpu);
106 return ops->cpu_boot(cpu);
111 static DECLARE_COMPLETION(cpu_running);
113 int __cpu_up(unsigned int cpu, struct task_struct *idle)
119 * We need to tell the secondary core where to find its stack and the
122 secondary_data.task = idle;
123 update_cpu_boot_status(CPU_MMU_OFF);
125 /* Now bring the CPU into our world */
126 ret = boot_secondary(cpu, idle);
128 pr_err("CPU%u: failed to boot: %d\n", cpu, ret);
133 * CPU was successfully started, wait for it to come online or
136 wait_for_completion_timeout(&cpu_running,
137 msecs_to_jiffies(5000));
141 pr_crit("CPU%u: failed to come online\n", cpu);
142 secondary_data.task = NULL;
143 status = READ_ONCE(secondary_data.status);
144 if (status == CPU_MMU_OFF)
145 status = READ_ONCE(__early_cpu_boot_status);
147 switch (status & CPU_BOOT_STATUS_MASK) {
149 pr_err("CPU%u: failed in unknown state : 0x%lx\n",
151 cpus_stuck_in_kernel++;
154 if (!op_cpu_kill(cpu)) {
155 pr_crit("CPU%u: died during early boot\n", cpu);
158 pr_crit("CPU%u: may not have shut down cleanly\n", cpu);
160 case CPU_STUCK_IN_KERNEL:
161 pr_crit("CPU%u: is stuck in kernel\n", cpu);
162 if (status & CPU_STUCK_REASON_52_BIT_VA)
163 pr_crit("CPU%u: does not support 52-bit VAs\n", cpu);
164 if (status & CPU_STUCK_REASON_NO_GRAN) {
165 pr_crit("CPU%u: does not support %luK granule\n",
166 cpu, PAGE_SIZE / SZ_1K);
168 cpus_stuck_in_kernel++;
170 case CPU_PANIC_KERNEL:
171 panic("CPU%u detected unsupported configuration\n", cpu);
177 static void init_gic_priority_masking(void)
181 if (WARN_ON(!gic_enable_sre()))
184 cpuflags = read_sysreg(daif);
186 WARN_ON(!(cpuflags & PSR_I_BIT));
187 WARN_ON(!(cpuflags & PSR_F_BIT));
189 gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET);
193 * This is the secondary CPU boot entry. We're using this CPUs
194 * idle thread stack, but a set of temporary page tables.
196 asmlinkage notrace void secondary_start_kernel(void)
198 u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
199 struct mm_struct *mm = &init_mm;
200 const struct cpu_operations *ops;
201 unsigned int cpu = smp_processor_id();
204 * All kernel threads share the same mm context; grab a
205 * reference and switch to it.
208 current->active_mm = mm;
211 * TTBR0 is only used for the identity mapping at this stage. Make it
212 * point to zero page to avoid speculatively fetching new entries.
214 cpu_uninstall_idmap();
216 if (system_uses_irq_prio_masking())
217 init_gic_priority_masking();
219 rcu_cpu_starting(cpu);
220 trace_hardirqs_off();
223 * If the system has established the capabilities, make sure
224 * this CPU ticks all of those. If it doesn't, the CPU will
225 * fail to come online.
227 check_local_cpu_capabilities();
229 ops = get_cpu_ops(cpu);
230 if (ops->cpu_postboot)
234 * Log the CPU info before it is marked online and might get read.
237 store_cpu_topology(cpu);
240 * Enable GIC and timers.
242 notify_cpu_starting(cpu);
249 * OK, now it's safe to let the boot CPU continue. Wait for
250 * the CPU migration code to notice that the CPU is online
251 * before we continue.
253 pr_info("CPU%u: Booted secondary processor 0x%010lx [0x%08x]\n",
254 cpu, (unsigned long)mpidr,
256 update_cpu_boot_status(CPU_BOOT_SUCCESS);
257 set_cpu_online(cpu, true);
258 complete(&cpu_running);
260 local_daif_restore(DAIF_PROCCTX);
263 * OK, it's off to the idle thread for us
265 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
268 #ifdef CONFIG_HOTPLUG_CPU
269 static int op_cpu_disable(unsigned int cpu)
271 const struct cpu_operations *ops = get_cpu_ops(cpu);
274 * If we don't have a cpu_die method, abort before we reach the point
275 * of no return. CPU0 may not have an cpu_ops, so test for it.
277 if (!ops || !ops->cpu_die)
281 * We may need to abort a hot unplug for some other mechanism-specific
284 if (ops->cpu_disable)
285 return ops->cpu_disable(cpu);
291 * __cpu_disable runs on the processor to be shutdown.
293 int __cpu_disable(void)
295 unsigned int cpu = smp_processor_id();
298 ret = op_cpu_disable(cpu);
302 remove_cpu_topology(cpu);
303 numa_remove_cpu(cpu);
306 * Take this CPU offline. Once we clear this, we can't return,
307 * and we must not schedule until we're ready to give up the cpu.
309 set_cpu_online(cpu, false);
313 * OK - migrate IRQs away from this CPU
315 irq_migrate_all_off_this_cpu();
320 static int op_cpu_kill(unsigned int cpu)
322 const struct cpu_operations *ops = get_cpu_ops(cpu);
325 * If we have no means of synchronising with the dying CPU, then assume
326 * that it is really dead. We can only wait for an arbitrary length of
327 * time and hope that it's dead, so let's skip the wait and just hope.
332 return ops->cpu_kill(cpu);
336 * called on the thread which is asking for a CPU to be shutdown -
337 * waits until shutdown has completed, or it is timed out.
339 void __cpu_die(unsigned int cpu)
343 if (!cpu_wait_death(cpu, 5)) {
344 pr_crit("CPU%u: cpu didn't die\n", cpu);
347 pr_debug("CPU%u: shutdown\n", cpu);
350 * Now that the dying CPU is beyond the point of no return w.r.t.
351 * in-kernel synchronisation, try to get the firwmare to help us to
352 * verify that it has really left the kernel before we consider
353 * clobbering anything it might still be using.
355 err = op_cpu_kill(cpu);
357 pr_warn("CPU%d may not have shut down cleanly: %d\n", cpu, err);
361 * Called from the idle thread for the CPU which has been shutdown.
366 unsigned int cpu = smp_processor_id();
367 const struct cpu_operations *ops = get_cpu_ops(cpu);
373 /* Tell __cpu_die() that this CPU is now safe to dispose of */
374 (void)cpu_report_death();
377 * Actually shutdown the CPU. This must never fail. The specific hotplug
378 * mechanism must perform all required cache maintenance to ensure that
379 * no dirty lines are lost in the process of shutting down the CPU.
387 static void __cpu_try_die(int cpu)
389 #ifdef CONFIG_HOTPLUG_CPU
390 const struct cpu_operations *ops = get_cpu_ops(cpu);
392 if (ops && ops->cpu_die)
398 * Kill the calling secondary CPU, early in bringup before it is turned
401 void cpu_die_early(void)
403 int cpu = smp_processor_id();
405 pr_crit("CPU%d: will not boot\n", cpu);
407 /* Mark this CPU absent */
408 set_cpu_present(cpu, 0);
409 rcu_report_dead(cpu);
411 if (IS_ENABLED(CONFIG_HOTPLUG_CPU)) {
412 update_cpu_boot_status(CPU_KILL_ME);
416 update_cpu_boot_status(CPU_STUCK_IN_KERNEL);
421 static void __init hyp_mode_check(void)
423 if (is_hyp_mode_available())
424 pr_info("CPU: All CPU(s) started at EL2\n");
425 else if (is_hyp_mode_mismatched())
426 WARN_TAINT(1, TAINT_CPU_OUT_OF_SPEC,
427 "CPU: CPUs started in inconsistent modes");
429 pr_info("CPU: All CPU(s) started at EL1\n");
430 if (IS_ENABLED(CONFIG_KVM) && !is_kernel_in_hyp_mode()) {
431 kvm_compute_layout();
432 kvm_apply_hyp_relocations();
436 void __init smp_cpus_done(unsigned int max_cpus)
438 pr_info("SMP: Total of %d processors activated.\n", num_online_cpus());
439 setup_cpu_features();
441 apply_alternatives_all();
442 mark_linear_text_alias_ro();
445 void __init smp_prepare_boot_cpu(void)
448 * The runtime per-cpu areas have been allocated by
449 * setup_per_cpu_areas(), and CPU0's boot time per-cpu area will be
450 * freed shortly, so we must move over to the runtime per-cpu area.
452 set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
453 cpuinfo_store_boot_cpu();
456 * We now know enough about the boot CPU to apply the
457 * alternatives that cannot wait until interrupt handling
458 * and/or scheduling is enabled.
460 apply_boot_alternatives();
462 /* Conditionally switch to GIC PMR for interrupt masking */
463 if (system_uses_irq_prio_masking())
464 init_gic_priority_masking();
466 kasan_init_hw_tags();
470 * Duplicate MPIDRs are a recipe for disaster. Scan all initialized
471 * entries and check for duplicates. If any is found just ignore the
472 * cpu. cpu_logical_map was initialized to INVALID_HWID to avoid
473 * matching valid MPIDR values.
475 static bool __init is_mpidr_duplicate(unsigned int cpu, u64 hwid)
479 for (i = 1; (i < cpu) && (i < NR_CPUS); i++)
480 if (cpu_logical_map(i) == hwid)
486 * Initialize cpu operations for a logical cpu and
487 * set it in the possible mask on success
489 static int __init smp_cpu_setup(int cpu)
491 const struct cpu_operations *ops;
493 if (init_cpu_ops(cpu))
496 ops = get_cpu_ops(cpu);
497 if (ops->cpu_init(cpu))
500 set_cpu_possible(cpu, true);
505 static bool bootcpu_valid __initdata;
506 static unsigned int cpu_count = 1;
509 static struct acpi_madt_generic_interrupt cpu_madt_gicc[NR_CPUS];
511 struct acpi_madt_generic_interrupt *acpi_cpu_get_madt_gicc(int cpu)
513 return &cpu_madt_gicc[cpu];
515 EXPORT_SYMBOL_GPL(acpi_cpu_get_madt_gicc);
518 * acpi_map_gic_cpu_interface - parse processor MADT entry
520 * Carry out sanity checks on MADT processor entry and initialize
521 * cpu_logical_map on success
524 acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
526 u64 hwid = processor->arm_mpidr;
528 if (!(processor->flags & ACPI_MADT_ENABLED)) {
529 pr_debug("skipping disabled CPU entry with 0x%llx MPIDR\n", hwid);
533 if (hwid & ~MPIDR_HWID_BITMASK || hwid == INVALID_HWID) {
534 pr_err("skipping CPU entry with invalid MPIDR 0x%llx\n", hwid);
538 if (is_mpidr_duplicate(cpu_count, hwid)) {
539 pr_err("duplicate CPU MPIDR 0x%llx in MADT\n", hwid);
543 /* Check if GICC structure of boot CPU is available in the MADT */
544 if (cpu_logical_map(0) == hwid) {
546 pr_err("duplicate boot CPU MPIDR: 0x%llx in MADT\n",
550 bootcpu_valid = true;
551 cpu_madt_gicc[0] = *processor;
555 if (cpu_count >= NR_CPUS)
558 /* map the logical cpu id to cpu MPIDR */
559 set_cpu_logical_map(cpu_count, hwid);
561 cpu_madt_gicc[cpu_count] = *processor;
564 * Set-up the ACPI parking protocol cpu entries
565 * while initializing the cpu_logical_map to
566 * avoid parsing MADT entries multiple times for
567 * nothing (ie a valid cpu_logical_map entry should
568 * contain a valid parking protocol data set to
569 * initialize the cpu if the parking protocol is
570 * the only available enable method).
572 acpi_set_mailbox_entry(cpu_count, processor);
578 acpi_parse_gic_cpu_interface(union acpi_subtable_headers *header,
579 const unsigned long end)
581 struct acpi_madt_generic_interrupt *processor;
583 processor = (struct acpi_madt_generic_interrupt *)header;
584 if (BAD_MADT_GICC_ENTRY(processor, end))
587 acpi_table_print_madt_entry(&header->common);
589 acpi_map_gic_cpu_interface(processor);
594 static void __init acpi_parse_and_init_cpus(void)
599 * do a walk of MADT to determine how many CPUs
600 * we have including disabled CPUs, and get information
601 * we need for SMP init.
603 acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
604 acpi_parse_gic_cpu_interface, 0);
607 * In ACPI, SMP and CPU NUMA information is provided in separate
608 * static tables, namely the MADT and the SRAT.
610 * Thus, it is simpler to first create the cpu logical map through
611 * an MADT walk and then map the logical cpus to their node ids
614 acpi_map_cpus_to_nodes();
616 for (i = 0; i < nr_cpu_ids; i++)
617 early_map_cpu_to_node(i, acpi_numa_get_nid(i));
620 #define acpi_parse_and_init_cpus(...) do { } while (0)
624 * Enumerate the possible CPU set from the device tree and build the
625 * cpu logical map array containing MPIDR values related to logical
626 * cpus. Assumes that cpu_logical_map(0) has already been initialized.
628 static void __init of_parse_and_init_cpus(void)
630 struct device_node *dn;
632 for_each_of_cpu_node(dn) {
633 u64 hwid = of_get_cpu_hwid(dn, 0);
635 if (hwid & ~MPIDR_HWID_BITMASK)
638 if (is_mpidr_duplicate(cpu_count, hwid)) {
639 pr_err("%pOF: duplicate cpu reg properties in the DT\n",
645 * The numbering scheme requires that the boot CPU
646 * must be assigned logical id 0. Record it so that
647 * the logical map built from DT is validated and can
650 if (hwid == cpu_logical_map(0)) {
652 pr_err("%pOF: duplicate boot cpu reg property in DT\n",
657 bootcpu_valid = true;
658 early_map_cpu_to_node(0, of_node_to_nid(dn));
661 * cpu_logical_map has already been
662 * initialized and the boot cpu doesn't need
663 * the enable-method so continue without
669 if (cpu_count >= NR_CPUS)
672 pr_debug("cpu logical map 0x%llx\n", hwid);
673 set_cpu_logical_map(cpu_count, hwid);
675 early_map_cpu_to_node(cpu_count, of_node_to_nid(dn));
682 * Enumerate the possible CPU set from the device tree or ACPI and build the
683 * cpu logical map array containing MPIDR values related to logical
684 * cpus. Assumes that cpu_logical_map(0) has already been initialized.
686 void __init smp_init_cpus(void)
691 of_parse_and_init_cpus();
693 acpi_parse_and_init_cpus();
695 if (cpu_count > nr_cpu_ids)
696 pr_warn("Number of cores (%d) exceeds configured maximum of %u - clipping\n",
697 cpu_count, nr_cpu_ids);
699 if (!bootcpu_valid) {
700 pr_err("missing boot CPU MPIDR, not enabling secondaries\n");
705 * We need to set the cpu_logical_map entries before enabling
706 * the cpus so that cpu processor description entries (DT cpu nodes
707 * and ACPI MADT entries) can be retrieved by matching the cpu hwid
708 * with entries in cpu_logical_map while initializing the cpus.
709 * If the cpu set-up fails, invalidate the cpu_logical_map entry.
711 for (i = 1; i < nr_cpu_ids; i++) {
712 if (cpu_logical_map(i) != INVALID_HWID) {
713 if (smp_cpu_setup(i))
714 set_cpu_logical_map(i, INVALID_HWID);
719 void __init smp_prepare_cpus(unsigned int max_cpus)
721 const struct cpu_operations *ops;
724 unsigned int this_cpu;
728 this_cpu = smp_processor_id();
729 store_cpu_topology(this_cpu);
730 numa_store_cpu_info(this_cpu);
731 numa_add_cpu(this_cpu);
734 * If UP is mandated by "nosmp" (which implies "maxcpus=0"), don't set
735 * secondary CPUs present.
741 * Initialise the present map (which describes the set of CPUs
742 * actually populated at the present time) and release the
743 * secondaries from the bootloader.
745 for_each_possible_cpu(cpu) {
747 per_cpu(cpu_number, cpu) = cpu;
749 if (cpu == smp_processor_id())
752 ops = get_cpu_ops(cpu);
756 err = ops->cpu_prepare(cpu);
760 set_cpu_present(cpu, true);
761 numa_store_cpu_info(cpu);
765 static const char *ipi_types[NR_IPI] __tracepoint_string = {
766 [IPI_RESCHEDULE] = "Rescheduling interrupts",
767 [IPI_CALL_FUNC] = "Function call interrupts",
768 [IPI_CPU_STOP] = "CPU stop interrupts",
769 [IPI_CPU_CRASH_STOP] = "CPU stop (for crash dump) interrupts",
770 [IPI_TIMER] = "Timer broadcast interrupts",
771 [IPI_IRQ_WORK] = "IRQ work interrupts",
772 [IPI_WAKEUP] = "CPU wake-up interrupts",
775 static void smp_cross_call(const struct cpumask *target, unsigned int ipinr);
777 unsigned long irq_err_count;
779 int arch_show_interrupts(struct seq_file *p, int prec)
783 for (i = 0; i < NR_IPI; i++) {
784 seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
785 prec >= 4 ? " " : "");
786 for_each_online_cpu(cpu)
787 seq_printf(p, "%10u ", irq_desc_kstat_cpu(ipi_desc[i], cpu));
788 seq_printf(p, " %s\n", ipi_types[i]);
791 seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
795 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
797 smp_cross_call(mask, IPI_CALL_FUNC);
800 void arch_send_call_function_single_ipi(int cpu)
802 smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC);
805 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
806 void arch_send_wakeup_ipi_mask(const struct cpumask *mask)
808 smp_cross_call(mask, IPI_WAKEUP);
812 #ifdef CONFIG_IRQ_WORK
813 void arch_irq_work_raise(void)
815 smp_cross_call(cpumask_of(smp_processor_id()), IPI_IRQ_WORK);
819 static void local_cpu_stop(void)
821 set_cpu_online(smp_processor_id(), false);
824 sdei_mask_local_cpu();
829 * We need to implement panic_smp_self_stop() for parallel panic() calls, so
830 * that cpu_online_mask gets correctly updated and smp_send_stop() can skip
831 * CPUs that have already stopped themselves.
833 void panic_smp_self_stop(void)
838 #ifdef CONFIG_KEXEC_CORE
839 static atomic_t waiting_for_crash_ipi = ATOMIC_INIT(0);
842 static void ipi_cpu_crash_stop(unsigned int cpu, struct pt_regs *regs)
844 #ifdef CONFIG_KEXEC_CORE
845 crash_save_cpu(regs, cpu);
847 atomic_dec(&waiting_for_crash_ipi);
850 sdei_mask_local_cpu();
852 if (IS_ENABLED(CONFIG_HOTPLUG_CPU))
861 * Main handler for inter-processor interrupts
863 static void do_handle_IPI(int ipinr)
865 unsigned int cpu = smp_processor_id();
867 if ((unsigned)ipinr < NR_IPI)
868 trace_ipi_entry_rcuidle(ipi_types[ipinr]);
876 generic_smp_call_function_interrupt();
883 case IPI_CPU_CRASH_STOP:
884 if (IS_ENABLED(CONFIG_KEXEC_CORE)) {
885 ipi_cpu_crash_stop(cpu, get_irq_regs());
891 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
893 tick_receive_broadcast();
897 #ifdef CONFIG_IRQ_WORK
903 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
905 WARN_ONCE(!acpi_parking_protocol_valid(cpu),
906 "CPU%u: Wake-up IPI outside the ACPI parking protocol\n",
912 pr_crit("CPU%u: Unknown IPI message 0x%x\n", cpu, ipinr);
916 if ((unsigned)ipinr < NR_IPI)
917 trace_ipi_exit_rcuidle(ipi_types[ipinr]);
920 static irqreturn_t ipi_handler(int irq, void *data)
922 do_handle_IPI(irq - ipi_irq_base);
926 static void smp_cross_call(const struct cpumask *target, unsigned int ipinr)
928 trace_ipi_raise(target, ipi_types[ipinr]);
929 __ipi_send_mask(ipi_desc[ipinr], target);
932 static void ipi_setup(int cpu)
936 if (WARN_ON_ONCE(!ipi_irq_base))
939 for (i = 0; i < nr_ipi; i++)
940 enable_percpu_irq(ipi_irq_base + i, 0);
943 #ifdef CONFIG_HOTPLUG_CPU
944 static void ipi_teardown(int cpu)
948 if (WARN_ON_ONCE(!ipi_irq_base))
951 for (i = 0; i < nr_ipi; i++)
952 disable_percpu_irq(ipi_irq_base + i);
956 void __init set_smp_ipi_range(int ipi_base, int n)
961 nr_ipi = min(n, NR_IPI);
963 for (i = 0; i < nr_ipi; i++) {
966 err = request_percpu_irq(ipi_base + i, ipi_handler,
970 ipi_desc[i] = irq_to_desc(ipi_base + i);
971 irq_set_status_flags(ipi_base + i, IRQ_HIDDEN);
974 ipi_irq_base = ipi_base;
976 /* Setup the boot CPU immediately */
977 ipi_setup(smp_processor_id());
980 void smp_send_reschedule(int cpu)
982 smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
985 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
986 void tick_broadcast(const struct cpumask *mask)
988 smp_cross_call(mask, IPI_TIMER);
993 * The number of CPUs online, not counting this CPU (which may not be
994 * fully online and so not counted in num_online_cpus()).
996 static inline unsigned int num_other_online_cpus(void)
998 unsigned int this_cpu_online = cpu_online(smp_processor_id());
1000 return num_online_cpus() - this_cpu_online;
1003 void smp_send_stop(void)
1005 unsigned long timeout;
1007 if (num_other_online_cpus()) {
1010 cpumask_copy(&mask, cpu_online_mask);
1011 cpumask_clear_cpu(smp_processor_id(), &mask);
1013 if (system_state <= SYSTEM_RUNNING)
1014 pr_crit("SMP: stopping secondary CPUs\n");
1015 smp_cross_call(&mask, IPI_CPU_STOP);
1018 /* Wait up to one second for other CPUs to stop */
1019 timeout = USEC_PER_SEC;
1020 while (num_other_online_cpus() && timeout--)
1023 if (num_other_online_cpus())
1024 pr_warn("SMP: failed to stop secondary CPUs %*pbl\n",
1025 cpumask_pr_args(cpu_online_mask));
1027 sdei_mask_local_cpu();
1030 #ifdef CONFIG_KEXEC_CORE
1031 void crash_smp_send_stop(void)
1033 static int cpus_stopped;
1035 unsigned long timeout;
1038 * This function can be called twice in panic path, but obviously
1039 * we execute this only once.
1047 * If this cpu is the only one alive at this point in time, online or
1048 * not, there are no stop messages to be sent around, so just back out.
1050 if (num_other_online_cpus() == 0) {
1051 sdei_mask_local_cpu();
1055 cpumask_copy(&mask, cpu_online_mask);
1056 cpumask_clear_cpu(smp_processor_id(), &mask);
1058 atomic_set(&waiting_for_crash_ipi, num_other_online_cpus());
1060 pr_crit("SMP: stopping secondary CPUs\n");
1061 smp_cross_call(&mask, IPI_CPU_CRASH_STOP);
1063 /* Wait up to one second for other CPUs to stop */
1064 timeout = USEC_PER_SEC;
1065 while ((atomic_read(&waiting_for_crash_ipi) > 0) && timeout--)
1068 if (atomic_read(&waiting_for_crash_ipi) > 0)
1069 pr_warn("SMP: failed to stop secondary CPUs %*pbl\n",
1070 cpumask_pr_args(&mask));
1072 sdei_mask_local_cpu();
1075 bool smp_crash_stop_failed(void)
1077 return (atomic_read(&waiting_for_crash_ipi) > 0);
1082 * not supported here
1084 int setup_profiling_timer(unsigned int multiplier)
1089 static bool have_cpu_die(void)
1091 #ifdef CONFIG_HOTPLUG_CPU
1092 int any_cpu = raw_smp_processor_id();
1093 const struct cpu_operations *ops = get_cpu_ops(any_cpu);
1095 if (ops && ops->cpu_die)
1101 bool cpus_are_stuck_in_kernel(void)
1103 bool smp_spin_tables = (num_possible_cpus() > 1 && !have_cpu_die());
1105 return !!cpus_stuck_in_kernel || smp_spin_tables ||
1106 is_protected_kvm_enabled();