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/kexec.h>
34 #include <linux/kvm_host.h>
36 #include <asm/alternative.h>
37 #include <asm/atomic.h>
38 #include <asm/cacheflush.h>
40 #include <asm/cputype.h>
41 #include <asm/cpu_ops.h>
42 #include <asm/daifflags.h>
43 #include <asm/kvm_mmu.h>
44 #include <asm/mmu_context.h>
46 #include <asm/pgtable.h>
47 #include <asm/pgalloc.h>
48 #include <asm/processor.h>
49 #include <asm/smp_plat.h>
50 #include <asm/sections.h>
51 #include <asm/tlbflush.h>
52 #include <asm/ptrace.h>
55 #define CREATE_TRACE_POINTS
56 #include <trace/events/ipi.h>
58 DEFINE_PER_CPU_READ_MOSTLY(int, cpu_number
);
59 EXPORT_PER_CPU_SYMBOL(cpu_number
);
62 * as from 2.5, kernels no longer have an init_tasks structure
63 * so we need some other way of telling a new secondary core
64 * where to place its SVC stack
66 struct secondary_data secondary_data
;
67 /* Number of CPUs which aren't online, but looping in kernel text. */
68 int cpus_stuck_in_kernel
;
80 #ifdef CONFIG_HOTPLUG_CPU
81 static int op_cpu_kill(unsigned int cpu
);
83 static inline int op_cpu_kill(unsigned int cpu
)
91 * Boot a secondary CPU, and assign it the specified idle task.
92 * This also gives us the initial stack to use for this CPU.
94 static int boot_secondary(unsigned int cpu
, struct task_struct
*idle
)
96 const struct cpu_operations
*ops
= get_cpu_ops(cpu
);
99 return ops
->cpu_boot(cpu
);
104 static DECLARE_COMPLETION(cpu_running
);
106 int __cpu_up(unsigned int cpu
, struct task_struct
*idle
)
112 * We need to tell the secondary core where to find its stack and the
115 secondary_data
.task
= idle
;
116 secondary_data
.stack
= task_stack_page(idle
) + THREAD_SIZE
;
117 #if defined(CONFIG_ARM64_PTR_AUTH)
118 secondary_data
.ptrauth_key
.apia
.lo
= idle
->thread
.keys_kernel
.apia
.lo
;
119 secondary_data
.ptrauth_key
.apia
.hi
= idle
->thread
.keys_kernel
.apia
.hi
;
121 update_cpu_boot_status(CPU_MMU_OFF
);
122 __flush_dcache_area(&secondary_data
, sizeof(secondary_data
));
124 /* Now bring the CPU into our world */
125 ret
= boot_secondary(cpu
, idle
);
127 pr_err("CPU%u: failed to boot: %d\n", cpu
, ret
);
132 * CPU was successfully started, wait for it to come online or
135 wait_for_completion_timeout(&cpu_running
,
136 msecs_to_jiffies(5000));
140 pr_crit("CPU%u: failed to come online\n", cpu
);
141 secondary_data
.task
= NULL
;
142 secondary_data
.stack
= NULL
;
143 #if defined(CONFIG_ARM64_PTR_AUTH)
144 secondary_data
.ptrauth_key
.apia
.lo
= 0;
145 secondary_data
.ptrauth_key
.apia
.hi
= 0;
147 __flush_dcache_area(&secondary_data
, sizeof(secondary_data
));
148 status
= READ_ONCE(secondary_data
.status
);
149 if (status
== CPU_MMU_OFF
)
150 status
= READ_ONCE(__early_cpu_boot_status
);
152 switch (status
& CPU_BOOT_STATUS_MASK
) {
154 pr_err("CPU%u: failed in unknown state : 0x%lx\n",
156 cpus_stuck_in_kernel
++;
159 if (!op_cpu_kill(cpu
)) {
160 pr_crit("CPU%u: died during early boot\n", cpu
);
163 pr_crit("CPU%u: may not have shut down cleanly\n", cpu
);
165 case CPU_STUCK_IN_KERNEL
:
166 pr_crit("CPU%u: is stuck in kernel\n", cpu
);
167 if (status
& CPU_STUCK_REASON_52_BIT_VA
)
168 pr_crit("CPU%u: does not support 52-bit VAs\n", cpu
);
169 if (status
& CPU_STUCK_REASON_NO_GRAN
) {
170 pr_crit("CPU%u: does not support %luK granule\n",
171 cpu
, PAGE_SIZE
/ SZ_1K
);
173 cpus_stuck_in_kernel
++;
175 case CPU_PANIC_KERNEL
:
176 panic("CPU%u detected unsupported configuration\n", cpu
);
182 static void init_gic_priority_masking(void)
186 if (WARN_ON(!gic_enable_sre()))
189 cpuflags
= read_sysreg(daif
);
191 WARN_ON(!(cpuflags
& PSR_I_BIT
));
193 gic_write_pmr(GIC_PRIO_IRQON
| GIC_PRIO_PSR_I_SET
);
197 * This is the secondary CPU boot entry. We're using this CPUs
198 * idle thread stack, but a set of temporary page tables.
200 asmlinkage notrace
void secondary_start_kernel(void)
202 u64 mpidr
= read_cpuid_mpidr() & MPIDR_HWID_BITMASK
;
203 struct mm_struct
*mm
= &init_mm
;
204 const struct cpu_operations
*ops
;
207 cpu
= task_cpu(current
);
208 set_my_cpu_offset(per_cpu_offset(cpu
));
211 * All kernel threads share the same mm context; grab a
212 * reference and switch to it.
215 current
->active_mm
= mm
;
218 * TTBR0 is only used for the identity mapping at this stage. Make it
219 * point to zero page to avoid speculatively fetching new entries.
221 cpu_uninstall_idmap();
223 if (system_uses_irq_prio_masking())
224 init_gic_priority_masking();
227 trace_hardirqs_off();
230 * If the system has established the capabilities, make sure
231 * this CPU ticks all of those. If it doesn't, the CPU will
232 * fail to come online.
234 check_local_cpu_capabilities();
236 ops
= get_cpu_ops(cpu
);
237 if (ops
->cpu_postboot
)
241 * Log the CPU info before it is marked online and might get read.
246 * Enable GIC and timers.
248 notify_cpu_starting(cpu
);
250 store_cpu_topology(cpu
);
254 * OK, now it's safe to let the boot CPU continue. Wait for
255 * the CPU migration code to notice that the CPU is online
256 * before we continue.
258 pr_info("CPU%u: Booted secondary processor 0x%010lx [0x%08x]\n",
259 cpu
, (unsigned long)mpidr
,
261 update_cpu_boot_status(CPU_BOOT_SUCCESS
);
262 set_cpu_online(cpu
, true);
263 complete(&cpu_running
);
265 local_daif_restore(DAIF_PROCCTX
);
268 * OK, it's off to the idle thread for us
270 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE
);
273 #ifdef CONFIG_HOTPLUG_CPU
274 static int op_cpu_disable(unsigned int cpu
)
276 const struct cpu_operations
*ops
= get_cpu_ops(cpu
);
279 * If we don't have a cpu_die method, abort before we reach the point
280 * of no return. CPU0 may not have an cpu_ops, so test for it.
282 if (!ops
|| !ops
->cpu_die
)
286 * We may need to abort a hot unplug for some other mechanism-specific
289 if (ops
->cpu_disable
)
290 return ops
->cpu_disable(cpu
);
296 * __cpu_disable runs on the processor to be shutdown.
298 int __cpu_disable(void)
300 unsigned int cpu
= smp_processor_id();
303 ret
= op_cpu_disable(cpu
);
307 remove_cpu_topology(cpu
);
308 numa_remove_cpu(cpu
);
311 * Take this CPU offline. Once we clear this, we can't return,
312 * and we must not schedule until we're ready to give up the cpu.
314 set_cpu_online(cpu
, false);
317 * OK - migrate IRQs away from this CPU
319 irq_migrate_all_off_this_cpu();
324 static int op_cpu_kill(unsigned int cpu
)
326 const struct cpu_operations
*ops
= get_cpu_ops(cpu
);
329 * If we have no means of synchronising with the dying CPU, then assume
330 * that it is really dead. We can only wait for an arbitrary length of
331 * time and hope that it's dead, so let's skip the wait and just hope.
336 return ops
->cpu_kill(cpu
);
340 * called on the thread which is asking for a CPU to be shutdown -
341 * waits until shutdown has completed, or it is timed out.
343 void __cpu_die(unsigned int cpu
)
347 if (!cpu_wait_death(cpu
, 5)) {
348 pr_crit("CPU%u: cpu didn't die\n", cpu
);
351 pr_notice("CPU%u: shutdown\n", cpu
);
354 * Now that the dying CPU is beyond the point of no return w.r.t.
355 * in-kernel synchronisation, try to get the firwmare to help us to
356 * verify that it has really left the kernel before we consider
357 * clobbering anything it might still be using.
359 err
= op_cpu_kill(cpu
);
361 pr_warn("CPU%d may not have shut down cleanly: %d\n", cpu
, err
);
365 * Called from the idle thread for the CPU which has been shutdown.
370 unsigned int cpu
= smp_processor_id();
371 const struct cpu_operations
*ops
= get_cpu_ops(cpu
);
377 /* Tell __cpu_die() that this CPU is now safe to dispose of */
378 (void)cpu_report_death();
381 * Actually shutdown the CPU. This must never fail. The specific hotplug
382 * mechanism must perform all required cache maintenance to ensure that
383 * no dirty lines are lost in the process of shutting down the CPU.
391 static void __cpu_try_die(int cpu
)
393 #ifdef CONFIG_HOTPLUG_CPU
394 const struct cpu_operations
*ops
= get_cpu_ops(cpu
);
396 if (ops
&& ops
->cpu_die
)
402 * Kill the calling secondary CPU, early in bringup before it is turned
405 void cpu_die_early(void)
407 int cpu
= smp_processor_id();
409 pr_crit("CPU%d: will not boot\n", cpu
);
411 /* Mark this CPU absent */
412 set_cpu_present(cpu
, 0);
414 if (IS_ENABLED(CONFIG_HOTPLUG_CPU
)) {
415 update_cpu_boot_status(CPU_KILL_ME
);
419 update_cpu_boot_status(CPU_STUCK_IN_KERNEL
);
424 static void __init
hyp_mode_check(void)
426 if (is_hyp_mode_available())
427 pr_info("CPU: All CPU(s) started at EL2\n");
428 else if (is_hyp_mode_mismatched())
429 WARN_TAINT(1, TAINT_CPU_OUT_OF_SPEC
,
430 "CPU: CPUs started in inconsistent modes");
432 pr_info("CPU: All CPU(s) started at EL1\n");
433 if (IS_ENABLED(CONFIG_KVM_ARM_HOST
))
434 kvm_compute_layout();
437 void __init
smp_cpus_done(unsigned int max_cpus
)
439 pr_info("SMP: Total of %d processors activated.\n", num_online_cpus());
440 setup_cpu_features();
442 apply_alternatives_all();
443 mark_linear_text_alias_ro();
446 void __init
smp_prepare_boot_cpu(void)
448 set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
449 cpuinfo_store_boot_cpu();
452 * We now know enough about the boot CPU to apply the
453 * alternatives that cannot wait until interrupt handling
454 * and/or scheduling is enabled.
456 apply_boot_alternatives();
458 /* Conditionally switch to GIC PMR for interrupt masking */
459 if (system_uses_irq_prio_masking())
460 init_gic_priority_masking();
463 static u64 __init
of_get_cpu_mpidr(struct device_node
*dn
)
469 * A cpu node with missing "reg" property is
470 * considered invalid to build a cpu_logical_map
473 cell
= of_get_property(dn
, "reg", NULL
);
475 pr_err("%pOF: missing reg property\n", dn
);
479 hwid
= of_read_number(cell
, of_n_addr_cells(dn
));
481 * Non affinity bits must be set to 0 in the DT
483 if (hwid
& ~MPIDR_HWID_BITMASK
) {
484 pr_err("%pOF: invalid reg property\n", dn
);
491 * Duplicate MPIDRs are a recipe for disaster. Scan all initialized
492 * entries and check for duplicates. If any is found just ignore the
493 * cpu. cpu_logical_map was initialized to INVALID_HWID to avoid
494 * matching valid MPIDR values.
496 static bool __init
is_mpidr_duplicate(unsigned int cpu
, u64 hwid
)
500 for (i
= 1; (i
< cpu
) && (i
< NR_CPUS
); i
++)
501 if (cpu_logical_map(i
) == hwid
)
507 * Initialize cpu operations for a logical cpu and
508 * set it in the possible mask on success
510 static int __init
smp_cpu_setup(int cpu
)
512 const struct cpu_operations
*ops
;
514 if (init_cpu_ops(cpu
))
517 ops
= get_cpu_ops(cpu
);
518 if (ops
->cpu_init(cpu
))
521 set_cpu_possible(cpu
, true);
526 static bool bootcpu_valid __initdata
;
527 static unsigned int cpu_count
= 1;
530 static struct acpi_madt_generic_interrupt cpu_madt_gicc
[NR_CPUS
];
532 struct acpi_madt_generic_interrupt
*acpi_cpu_get_madt_gicc(int cpu
)
534 return &cpu_madt_gicc
[cpu
];
538 * acpi_map_gic_cpu_interface - parse processor MADT entry
540 * Carry out sanity checks on MADT processor entry and initialize
541 * cpu_logical_map on success
544 acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt
*processor
)
546 u64 hwid
= processor
->arm_mpidr
;
548 if (!(processor
->flags
& ACPI_MADT_ENABLED
)) {
549 pr_debug("skipping disabled CPU entry with 0x%llx MPIDR\n", hwid
);
553 if (hwid
& ~MPIDR_HWID_BITMASK
|| hwid
== INVALID_HWID
) {
554 pr_err("skipping CPU entry with invalid MPIDR 0x%llx\n", hwid
);
558 if (is_mpidr_duplicate(cpu_count
, hwid
)) {
559 pr_err("duplicate CPU MPIDR 0x%llx in MADT\n", hwid
);
563 /* Check if GICC structure of boot CPU is available in the MADT */
564 if (cpu_logical_map(0) == hwid
) {
566 pr_err("duplicate boot CPU MPIDR: 0x%llx in MADT\n",
570 bootcpu_valid
= true;
571 cpu_madt_gicc
[0] = *processor
;
575 if (cpu_count
>= NR_CPUS
)
578 /* map the logical cpu id to cpu MPIDR */
579 cpu_logical_map(cpu_count
) = hwid
;
581 cpu_madt_gicc
[cpu_count
] = *processor
;
584 * Set-up the ACPI parking protocol cpu entries
585 * while initializing the cpu_logical_map to
586 * avoid parsing MADT entries multiple times for
587 * nothing (ie a valid cpu_logical_map entry should
588 * contain a valid parking protocol data set to
589 * initialize the cpu if the parking protocol is
590 * the only available enable method).
592 acpi_set_mailbox_entry(cpu_count
, processor
);
598 acpi_parse_gic_cpu_interface(union acpi_subtable_headers
*header
,
599 const unsigned long end
)
601 struct acpi_madt_generic_interrupt
*processor
;
603 processor
= (struct acpi_madt_generic_interrupt
*)header
;
604 if (BAD_MADT_GICC_ENTRY(processor
, end
))
607 acpi_table_print_madt_entry(&header
->common
);
609 acpi_map_gic_cpu_interface(processor
);
614 static void __init
acpi_parse_and_init_cpus(void)
619 * do a walk of MADT to determine how many CPUs
620 * we have including disabled CPUs, and get information
621 * we need for SMP init.
623 acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT
,
624 acpi_parse_gic_cpu_interface
, 0);
627 * In ACPI, SMP and CPU NUMA information is provided in separate
628 * static tables, namely the MADT and the SRAT.
630 * Thus, it is simpler to first create the cpu logical map through
631 * an MADT walk and then map the logical cpus to their node ids
634 acpi_map_cpus_to_nodes();
636 for (i
= 0; i
< nr_cpu_ids
; i
++)
637 early_map_cpu_to_node(i
, acpi_numa_get_nid(i
));
640 #define acpi_parse_and_init_cpus(...) do { } while (0)
644 * Enumerate the possible CPU set from the device tree and build the
645 * cpu logical map array containing MPIDR values related to logical
646 * cpus. Assumes that cpu_logical_map(0) has already been initialized.
648 static void __init
of_parse_and_init_cpus(void)
650 struct device_node
*dn
;
652 for_each_of_cpu_node(dn
) {
653 u64 hwid
= of_get_cpu_mpidr(dn
);
655 if (hwid
== INVALID_HWID
)
658 if (is_mpidr_duplicate(cpu_count
, hwid
)) {
659 pr_err("%pOF: duplicate cpu reg properties in the DT\n",
665 * The numbering scheme requires that the boot CPU
666 * must be assigned logical id 0. Record it so that
667 * the logical map built from DT is validated and can
670 if (hwid
== cpu_logical_map(0)) {
672 pr_err("%pOF: duplicate boot cpu reg property in DT\n",
677 bootcpu_valid
= true;
678 early_map_cpu_to_node(0, of_node_to_nid(dn
));
681 * cpu_logical_map has already been
682 * initialized and the boot cpu doesn't need
683 * the enable-method so continue without
689 if (cpu_count
>= NR_CPUS
)
692 pr_debug("cpu logical map 0x%llx\n", hwid
);
693 cpu_logical_map(cpu_count
) = hwid
;
695 early_map_cpu_to_node(cpu_count
, of_node_to_nid(dn
));
702 * Enumerate the possible CPU set from the device tree or ACPI and build the
703 * cpu logical map array containing MPIDR values related to logical
704 * cpus. Assumes that cpu_logical_map(0) has already been initialized.
706 void __init
smp_init_cpus(void)
711 of_parse_and_init_cpus();
713 acpi_parse_and_init_cpus();
715 if (cpu_count
> nr_cpu_ids
)
716 pr_warn("Number of cores (%d) exceeds configured maximum of %u - clipping\n",
717 cpu_count
, nr_cpu_ids
);
719 if (!bootcpu_valid
) {
720 pr_err("missing boot CPU MPIDR, not enabling secondaries\n");
725 * We need to set the cpu_logical_map entries before enabling
726 * the cpus so that cpu processor description entries (DT cpu nodes
727 * and ACPI MADT entries) can be retrieved by matching the cpu hwid
728 * with entries in cpu_logical_map while initializing the cpus.
729 * If the cpu set-up fails, invalidate the cpu_logical_map entry.
731 for (i
= 1; i
< nr_cpu_ids
; i
++) {
732 if (cpu_logical_map(i
) != INVALID_HWID
) {
733 if (smp_cpu_setup(i
))
734 cpu_logical_map(i
) = INVALID_HWID
;
739 void __init
smp_prepare_cpus(unsigned int max_cpus
)
741 const struct cpu_operations
*ops
;
744 unsigned int this_cpu
;
748 this_cpu
= smp_processor_id();
749 store_cpu_topology(this_cpu
);
750 numa_store_cpu_info(this_cpu
);
751 numa_add_cpu(this_cpu
);
754 * If UP is mandated by "nosmp" (which implies "maxcpus=0"), don't set
755 * secondary CPUs present.
761 * Initialise the present map (which describes the set of CPUs
762 * actually populated at the present time) and release the
763 * secondaries from the bootloader.
765 for_each_possible_cpu(cpu
) {
767 per_cpu(cpu_number
, cpu
) = cpu
;
769 if (cpu
== smp_processor_id())
772 ops
= get_cpu_ops(cpu
);
776 err
= ops
->cpu_prepare(cpu
);
780 set_cpu_present(cpu
, true);
781 numa_store_cpu_info(cpu
);
785 void (*__smp_cross_call
)(const struct cpumask
*, unsigned int);
787 void __init
set_smp_cross_call(void (*fn
)(const struct cpumask
*, unsigned int))
789 __smp_cross_call
= fn
;
792 static const char *ipi_types
[NR_IPI
] __tracepoint_string
= {
793 #define S(x,s) [x] = s
794 S(IPI_RESCHEDULE
, "Rescheduling interrupts"),
795 S(IPI_CALL_FUNC
, "Function call interrupts"),
796 S(IPI_CPU_STOP
, "CPU stop interrupts"),
797 S(IPI_CPU_CRASH_STOP
, "CPU stop (for crash dump) interrupts"),
798 S(IPI_TIMER
, "Timer broadcast interrupts"),
799 S(IPI_IRQ_WORK
, "IRQ work interrupts"),
800 S(IPI_WAKEUP
, "CPU wake-up interrupts"),
803 static void smp_cross_call(const struct cpumask
*target
, unsigned int ipinr
)
805 trace_ipi_raise(target
, ipi_types
[ipinr
]);
806 __smp_cross_call(target
, ipinr
);
809 void show_ipi_list(struct seq_file
*p
, int prec
)
813 for (i
= 0; i
< NR_IPI
; i
++) {
814 seq_printf(p
, "%*s%u:%s", prec
- 1, "IPI", i
,
815 prec
>= 4 ? " " : "");
816 for_each_online_cpu(cpu
)
817 seq_printf(p
, "%10u ",
818 __get_irq_stat(cpu
, ipi_irqs
[i
]));
819 seq_printf(p
, " %s\n", ipi_types
[i
]);
823 u64
smp_irq_stat_cpu(unsigned int cpu
)
828 for (i
= 0; i
< NR_IPI
; i
++)
829 sum
+= __get_irq_stat(cpu
, ipi_irqs
[i
]);
834 void arch_send_call_function_ipi_mask(const struct cpumask
*mask
)
836 smp_cross_call(mask
, IPI_CALL_FUNC
);
839 void arch_send_call_function_single_ipi(int cpu
)
841 smp_cross_call(cpumask_of(cpu
), IPI_CALL_FUNC
);
844 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
845 void arch_send_wakeup_ipi_mask(const struct cpumask
*mask
)
847 smp_cross_call(mask
, IPI_WAKEUP
);
851 #ifdef CONFIG_IRQ_WORK
852 void arch_irq_work_raise(void)
854 if (__smp_cross_call
)
855 smp_cross_call(cpumask_of(smp_processor_id()), IPI_IRQ_WORK
);
859 static void local_cpu_stop(void)
861 set_cpu_online(smp_processor_id(), false);
864 sdei_mask_local_cpu();
869 * We need to implement panic_smp_self_stop() for parallel panic() calls, so
870 * that cpu_online_mask gets correctly updated and smp_send_stop() can skip
871 * CPUs that have already stopped themselves.
873 void panic_smp_self_stop(void)
878 #ifdef CONFIG_KEXEC_CORE
879 static atomic_t waiting_for_crash_ipi
= ATOMIC_INIT(0);
882 static void ipi_cpu_crash_stop(unsigned int cpu
, struct pt_regs
*regs
)
884 #ifdef CONFIG_KEXEC_CORE
885 crash_save_cpu(regs
, cpu
);
887 atomic_dec(&waiting_for_crash_ipi
);
890 sdei_mask_local_cpu();
892 if (IS_ENABLED(CONFIG_HOTPLUG_CPU
))
901 * Main handler for inter-processor interrupts
903 void handle_IPI(int ipinr
, struct pt_regs
*regs
)
905 unsigned int cpu
= smp_processor_id();
906 struct pt_regs
*old_regs
= set_irq_regs(regs
);
908 if ((unsigned)ipinr
< NR_IPI
) {
909 trace_ipi_entry_rcuidle(ipi_types
[ipinr
]);
910 __inc_irq_stat(cpu
, ipi_irqs
[ipinr
]);
920 generic_smp_call_function_interrupt();
930 case IPI_CPU_CRASH_STOP
:
931 if (IS_ENABLED(CONFIG_KEXEC_CORE
)) {
933 ipi_cpu_crash_stop(cpu
, regs
);
939 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
942 tick_receive_broadcast();
947 #ifdef CONFIG_IRQ_WORK
955 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
957 WARN_ONCE(!acpi_parking_protocol_valid(cpu
),
958 "CPU%u: Wake-up IPI outside the ACPI parking protocol\n",
964 pr_crit("CPU%u: Unknown IPI message 0x%x\n", cpu
, ipinr
);
968 if ((unsigned)ipinr
< NR_IPI
)
969 trace_ipi_exit_rcuidle(ipi_types
[ipinr
]);
970 set_irq_regs(old_regs
);
973 void smp_send_reschedule(int cpu
)
975 smp_cross_call(cpumask_of(cpu
), IPI_RESCHEDULE
);
978 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
979 void tick_broadcast(const struct cpumask
*mask
)
981 smp_cross_call(mask
, IPI_TIMER
);
986 * The number of CPUs online, not counting this CPU (which may not be
987 * fully online and so not counted in num_online_cpus()).
989 static inline unsigned int num_other_online_cpus(void)
991 unsigned int this_cpu_online
= cpu_online(smp_processor_id());
993 return num_online_cpus() - this_cpu_online
;
996 void smp_send_stop(void)
998 unsigned long timeout
;
1000 if (num_other_online_cpus()) {
1003 cpumask_copy(&mask
, cpu_online_mask
);
1004 cpumask_clear_cpu(smp_processor_id(), &mask
);
1006 if (system_state
<= SYSTEM_RUNNING
)
1007 pr_crit("SMP: stopping secondary CPUs\n");
1008 smp_cross_call(&mask
, IPI_CPU_STOP
);
1011 /* Wait up to one second for other CPUs to stop */
1012 timeout
= USEC_PER_SEC
;
1013 while (num_other_online_cpus() && timeout
--)
1016 if (num_other_online_cpus())
1017 pr_warn("SMP: failed to stop secondary CPUs %*pbl\n",
1018 cpumask_pr_args(cpu_online_mask
));
1020 sdei_mask_local_cpu();
1023 #ifdef CONFIG_KEXEC_CORE
1024 void crash_smp_send_stop(void)
1026 static int cpus_stopped
;
1028 unsigned long timeout
;
1031 * This function can be called twice in panic path, but obviously
1032 * we execute this only once.
1040 * If this cpu is the only one alive at this point in time, online or
1041 * not, there are no stop messages to be sent around, so just back out.
1043 if (num_other_online_cpus() == 0) {
1044 sdei_mask_local_cpu();
1048 cpumask_copy(&mask
, cpu_online_mask
);
1049 cpumask_clear_cpu(smp_processor_id(), &mask
);
1051 atomic_set(&waiting_for_crash_ipi
, num_other_online_cpus());
1053 pr_crit("SMP: stopping secondary CPUs\n");
1054 smp_cross_call(&mask
, IPI_CPU_CRASH_STOP
);
1056 /* Wait up to one second for other CPUs to stop */
1057 timeout
= USEC_PER_SEC
;
1058 while ((atomic_read(&waiting_for_crash_ipi
) > 0) && timeout
--)
1061 if (atomic_read(&waiting_for_crash_ipi
) > 0)
1062 pr_warn("SMP: failed to stop secondary CPUs %*pbl\n",
1063 cpumask_pr_args(&mask
));
1065 sdei_mask_local_cpu();
1068 bool smp_crash_stop_failed(void)
1070 return (atomic_read(&waiting_for_crash_ipi
) > 0);
1075 * not supported here
1077 int setup_profiling_timer(unsigned int multiplier
)
1082 static bool have_cpu_die(void)
1084 #ifdef CONFIG_HOTPLUG_CPU
1085 int any_cpu
= raw_smp_processor_id();
1086 const struct cpu_operations
*ops
= get_cpu_ops(any_cpu
);
1088 if (ops
&& ops
->cpu_die
)
1094 bool cpus_are_stuck_in_kernel(void)
1096 bool smp_spin_tables
= (num_possible_cpus() > 1 && !have_cpu_die());
1098 return !!cpus_stuck_in_kernel
|| smp_spin_tables
;