// SPDX-License-Identifier: GPL-2.0-or-later/*** SMP Support**** Copyright (C) 1999 Walt Drummond <drummond@valinux.com>** Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>** Copyright (C) 2001,2004 Grant Grundler <grundler@parisc-linux.org>** ** Lots of stuff stolen from arch/alpha/kernel/smp.c** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^)**** Thanks to John Curry and Ullas Ponnadi. I learned a lot from their work.** -grant (1/12/2001)***/#include <linux/types.h>#include <linux/spinlock.h> #include <linux/kernel.h>#include <linux/module.h>#include <linux/sched/mm.h>#include <linux/init.h>#include <linux/interrupt.h>#include <linux/smp.h>#include <linux/kernel_stat.h>#include <linux/mm.h>#include <linux/err.h>#include <linux/delay.h>#include <linux/bitops.h>#include <linux/ftrace.h>#include <linux/cpu.h>#include <linux/kgdb.h>#include <linux/sched/hotplug.h> #include <linux/atomic.h>#include <asm/current.h>#include <asm/delay.h>#include <asm/tlbflush.h> #include <asm/io.h>#include <asm/irq.h> /* for CPU_IRQ_REGION and friends */#include <asm/mmu_context.h>#include <asm/page.h>#include <asm/processor.h>#include <asm/ptrace.h>#include <asm/unistd.h>#include <asm/cacheflush.h> #undef DEBUG_SMP#ifdef DEBUG_SMPstatic int smp_debug_lvl = 0;#define smp_debug(lvl, printargs...) \ if (lvl >= smp_debug_lvl) \ printk(printargs);#else#define smp_debug(lvl, ...) do { } while(0)#endif /* DEBUG_SMP */ volatile struct task_struct *smp_init_current_idle_task; /* track which CPU is booting */static volatile int cpu_now_booting; static DEFINE_PER_CPU(spinlock_t, ipi_lock); enum ipi_message_type { IPI_NOP=0, IPI_RESCHEDULE=1, IPI_CALL_FUNC, IPI_CPU_START, IPI_CPU_STOP, IPI_CPU_TEST,#ifdef CONFIG_KGDB IPI_ENTER_KGDB,#endif}; /********** SMP inter processor interrupt and communication routines */ #undef PER_CPU_IRQ_REGION#ifdef PER_CPU_IRQ_REGION/* XXX REVISIT Ignore for now.** *May* need this "hook" to register IPI handler** once we have perCPU ExtIntr switch tables.*/static voidipi_init(int cpuid){#error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region if(cpu_online(cpuid) ) { switch_to_idle_task(current); } return;}#endif /*** Yoink this CPU from the runnable list... ***/static voidhalt_processor(void) { /* REVISIT : redirect I/O Interrupts to another CPU? */ /* REVISIT : does PM *know* this CPU isn't available? */ set_cpu_online(smp_processor_id(), false); local_irq_disable(); __pdc_cpu_rendezvous(); for (;;) ;} irqreturn_t __irq_entryipi_interrupt(int irq, void *dev_id) { int this_cpu = smp_processor_id(); struct cpuinfo_parisc *p = &per_cpu(cpu_data, this_cpu); unsigned long ops; unsigned long flags; for (;;) { spinlock_t *lock = &per_cpu(ipi_lock, this_cpu); spin_lock_irqsave(lock, flags); ops = p->pending_ipi; p->pending_ipi = 0; spin_unlock_irqrestore(lock, flags); mb(); /* Order bit clearing and data access. */ if (!ops) break; while (ops) { unsigned long which = ffz(~ops); ops &= ~(1 << which); switch (which) { case IPI_NOP: smp_debug(100, KERN_DEBUG "CPU%d IPI_NOP\n", this_cpu); break; case IPI_RESCHEDULE: smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu); inc_irq_stat(irq_resched_count); scheduler_ipi(); break; case IPI_CALL_FUNC: smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu); inc_irq_stat(irq_call_count); generic_smp_call_function_interrupt(); break; case IPI_CPU_START: smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_START\n", this_cpu); break; case IPI_CPU_STOP: smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_STOP\n", this_cpu); halt_processor(); break; case IPI_CPU_TEST: smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu); break;#ifdef CONFIG_KGDB case IPI_ENTER_KGDB: smp_debug(100, KERN_DEBUG "CPU%d ENTER_KGDB\n", this_cpu); kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); break;#endif default: printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n", this_cpu, which); return IRQ_NONE; } /* Switch */ /* before doing more, let in any pending interrupts */ if (ops) { local_irq_enable(); local_irq_disable(); } } /* while (ops) */ } return IRQ_HANDLED;} static inline voidipi_send(int cpu, enum ipi_message_type op){ struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpu); spinlock_t *lock = &per_cpu(ipi_lock, cpu); unsigned long flags; spin_lock_irqsave(lock, flags); p->pending_ipi |= 1 << op; gsc_writel(IPI_IRQ - CPU_IRQ_BASE, p->hpa); spin_unlock_irqrestore(lock, flags);} static voidsend_IPI_mask(const struct cpumask *mask, enum ipi_message_type op){ int cpu; for_each_cpu(cpu, mask) ipi_send(cpu, op);} static inline voidsend_IPI_single(int dest_cpu, enum ipi_message_type op){ BUG_ON(dest_cpu == NO_PROC_ID); ipi_send(dest_cpu, op);} static inline voidsend_IPI_allbutself(enum ipi_message_type op){ int i; preempt_disable(); for_each_online_cpu(i) { if (i != smp_processor_id()) send_IPI_single(i, op); } preempt_enable();} #ifdef CONFIG_KGDBvoid kgdb_roundup_cpus(void){ send_IPI_allbutself(IPI_ENTER_KGDB);}#endif inline void smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); } voidarch_smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); } voidsmp_send_all_nop(void){ send_IPI_allbutself(IPI_NOP);} void arch_send_call_function_ipi_mask(const struct cpumask *mask){ send_IPI_mask(mask, IPI_CALL_FUNC);} void arch_send_call_function_single_ipi(int cpu){ send_IPI_single(cpu, IPI_CALL_FUNC);} /* * Called by secondaries to update state and initialize CPU registers. */static voidsmp_cpu_init(int cpunum){ /* Set modes and Enable floating point coprocessor */ init_per_cpu(cpunum); disable_sr_hashing(); mb(); /* Well, support 2.4 linux scheme as well. */ if (cpu_online(cpunum)) { extern void machine_halt(void); /* arch/parisc.../process.c */ printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum); machine_halt(); } notify_cpu_starting(cpunum); set_cpu_online(cpunum, true); /* Initialise the idle task for this CPU */ mmgrab(&init_mm); current->active_mm = &init_mm; BUG_ON(current->mm); enter_lazy_tlb(&init_mm, current); init_IRQ(); /* make sure no IRQs are enabled or pending */ parisc_clockevent_init();} /* * Slaves start using C here. Indirectly called from smp_slave_stext. * Do what start_kernel() and main() do for boot strap processor (aka monarch) */void smp_callin(unsigned long pdce_proc){ int slave_id = cpu_now_booting; #ifdef CONFIG_64BIT WARN_ON(((unsigned long)(PAGE0->mem_pdc_hi) << 32 | PAGE0->mem_pdc) != pdce_proc);#endif smp_cpu_init(slave_id); flush_cache_all_local(); /* start with known state */ flush_tlb_all_local(NULL); local_irq_enable(); /* Interrupts have been off until now */ cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); /* NOTREACHED */ panic("smp_callin() AAAAaaaaahhhh....\n");} /* * Bring one cpu online. */static int smp_boot_one_cpu(int cpuid, struct task_struct *idle){ const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid); long timeout; #ifdef CONFIG_HOTPLUG_CPU int i; /* reset irq statistics for this CPU */ memset(&per_cpu(irq_stat, cpuid), 0, sizeof(irq_cpustat_t)); for (i = 0; i < NR_IRQS; i++) { struct irq_desc *desc = irq_to_desc(i); if (desc) *per_cpu_ptr(desc->kstat_irqs, cpuid) = (struct irqstat) { }; }#endif /* wait until last booting CPU has started. */ while (cpu_now_booting) ; /* Let _start know what logical CPU we're booting ** (offset into init_tasks[],cpu_data[]) */ cpu_now_booting = cpuid; /* ** boot strap code needs to know the task address since ** it also contains the process stack. */ smp_init_current_idle_task = idle ; mb(); printk(KERN_INFO "Releasing cpu %d now, hpa=%lx\n", cpuid, p->hpa); /* ** This gets PDC to release the CPU from a very tight loop. ** ** From the PA-RISC 2.0 Firmware Architecture Reference Specification: ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which ** is executed after receiving the rendezvous signal (an interrupt to ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the ** contents of memory are valid." */ gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, p->hpa); mb(); /* * OK, wait a bit for that CPU to finish staggering about. * Slave will set a bit when it reaches smp_cpu_init(). * Once the "monarch CPU" sees the bit change, it can move on. */ for (timeout = 0; timeout < 10000; timeout++) { if(cpu_online(cpuid)) { /* Which implies Slave has started up */ cpu_now_booting = 0; goto alive ; } udelay(100); barrier(); } printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid); return -1; alive: /* Remember the Slave data */ smp_debug(100, KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n", cpuid, timeout * 100); return 0;} void __init smp_prepare_boot_cpu(void){ pr_info("SMP: bootstrap CPU ID is 0\n");} /*** inventory.c:do_inventory() hasn't yet been run and thus we** don't 'discover' the additional CPUs until later.*/void __init smp_prepare_cpus(unsigned int max_cpus){ int cpu; for_each_possible_cpu(cpu) spin_lock_init(&per_cpu(ipi_lock, cpu)); init_cpu_present(cpumask_of(0));} void __init smp_cpus_done(unsigned int cpu_max){} int __cpu_up(unsigned int cpu, struct task_struct *tidle){ if (cpu_online(cpu)) return 0; if (num_online_cpus() < nr_cpu_ids && num_online_cpus() < setup_max_cpus && smp_boot_one_cpu(cpu, tidle)) return -EIO; return cpu_online(cpu) ? 0 : -EIO;} /* * __cpu_disable runs on the processor to be shutdown. */int __cpu_disable(void){#ifdef CONFIG_HOTPLUG_CPU unsigned int cpu = smp_processor_id(); remove_cpu_topology(cpu); /* * Take this CPU offline. Once we clear this, we can't return, * and we must not schedule until we're ready to give up the cpu. */ set_cpu_online(cpu, false); /* Find a new timesync master */ if (cpu == time_keeper_id) { time_keeper_id = cpumask_first(cpu_online_mask); pr_info("CPU %d is now promoted to time-keeper master\n", time_keeper_id); } disable_percpu_irq(IPI_IRQ); irq_migrate_all_off_this_cpu(); flush_cache_all_local(); flush_tlb_all_local(NULL); /* disable all irqs, including timer irq */ local_irq_disable(); /* wait for next timer irq ... */ mdelay(1000/HZ+100); /* ... and then clear all pending external irqs */ set_eiem(0); mtctl(~0UL, CR_EIRR); mfctl(CR_EIRR); mtctl(0, CR_EIRR);#endif return 0;} /* * called on the thread which is asking for a CPU to be shutdown - * waits until shutdown has completed, or it is timed out. */void __cpu_die(unsigned int cpu){ pdc_cpu_rendezvous_lock();} void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu){ pr_info("CPU%u: is shutting down\n", cpu);Lines 1–500 of 507. Load more
// SPDX-License-Identifier: GPL-2.0-or-later /* ** SMP Support ** ** Copyright (C) 1999 Walt Drummond <drummond@valinux.com> ** Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com> ** Copyright (C) 2001,2004 Grant Grundler <grundler@parisc-linux.org> ** ** Lots of stuff stolen from arch/alpha/kernel/smp.c ** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^) ** ** Thanks to John Curry and Ullas Ponnadi. I learned a lot from their work. ** -grant (1/12/2001) ** */ #include <linux/types.h> #include <linux/spinlock.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/sched/mm.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/smp.h> #include <linux/kernel_stat.h> #include <linux/mm.h> #include <linux/err.h> #include <linux/delay.h> #include <linux/bitops.h> #include <linux/ftrace.h> #include <linux/cpu.h> #include <linux/kgdb.h> #include <linux/sched/hotplug.h> #include <linux/atomic.h> #include <asm/current.h> #include <asm/delay.h> #include <asm/tlbflush.h> #include <asm/io.h> #include <asm/irq.h> /* for CPU_IRQ_REGION and friends */ #include <asm/mmu_context.h> #include <asm/page.h> #include <asm/processor.h> #include <asm/ptrace.h> #include <asm/unistd.h> #include <asm/cacheflush.h> #undef DEBUG_SMP #ifdef DEBUG_SMP static int smp_debug_lvl = 0; #define smp_debug(lvl, printargs...) \ if (lvl >= smp_debug_lvl) \ printk(printargs); #else #define smp_debug(lvl, ...) do { } while(0) #endif /* DEBUG_SMP */ volatile struct task_struct *smp_init_current_idle_task; /* track which CPU is booting */ static volatile int cpu_now_booting; static DEFINE_PER_CPU(spinlock_t, ipi_lock); enum ipi_message_type { IPI_NOP=0, IPI_RESCHEDULE=1, IPI_CALL_FUNC, IPI_CPU_START, IPI_CPU_STOP, IPI_CPU_TEST, #ifdef CONFIG_KGDB IPI_ENTER_KGDB, #endif }; /********** SMP inter processor interrupt and communication routines */ #undef PER_CPU_IRQ_REGION #ifdef PER_CPU_IRQ_REGION /* XXX REVISIT Ignore for now. ** *May* need this "hook" to register IPI handler ** once we have perCPU ExtIntr switch tables. */ static void ipi_init(int cpuid) { #error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region if(cpu_online(cpuid) ) { switch_to_idle_task(current); } return; } #endif /* ** Yoink this CPU from the runnable list... ** */ static void halt_processor(void) { /* REVISIT : redirect I/O Interrupts to another CPU? */ /* REVISIT : does PM *know* this CPU isn't available? */ set_cpu_online(smp_processor_id(), false); local_irq_disable(); __pdc_cpu_rendezvous(); for (;;) ; } irqreturn_t __irq_entry ipi_interrupt(int irq, void *dev_id) { int this_cpu = smp_processor_id(); struct cpuinfo_parisc *p = &per_cpu(cpu_data, this_cpu); unsigned long ops; unsigned long flags; for (;;) { spinlock_t *lock = &per_cpu(ipi_lock, this_cpu); spin_lock_irqsave(lock, flags); ops = p->pending_ipi; p->pending_ipi = 0; spin_unlock_irqrestore(lock, flags); mb(); /* Order bit clearing and data access. */ if (!ops) break; while (ops) { unsigned long which = ffz(~ops); ops &= ~(1 << which); switch (which) { case IPI_NOP: smp_debug(100, KERN_DEBUG "CPU%d IPI_NOP\n", this_cpu); break; case IPI_RESCHEDULE: smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu); inc_irq_stat(irq_resched_count); scheduler_ipi(); break; case IPI_CALL_FUNC: smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu); inc_irq_stat(irq_call_count); generic_smp_call_function_interrupt(); break; case IPI_CPU_START: smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_START\n", this_cpu); break; case IPI_CPU_STOP: smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_STOP\n", this_cpu); halt_processor(); break; case IPI_CPU_TEST: smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu); break; #ifdef CONFIG_KGDB case IPI_ENTER_KGDB: smp_debug(100, KERN_DEBUG "CPU%d ENTER_KGDB\n", this_cpu); kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); break; #endif default: printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n", this_cpu, which); return IRQ_NONE; } /* Switch */ /* before doing more, let in any pending interrupts */ if (ops) { local_irq_enable(); local_irq_disable(); } } /* while (ops) */ } return IRQ_HANDLED; } static inline void ipi_send(int cpu, enum ipi_message_type op) { struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpu); spinlock_t *lock = &per_cpu(ipi_lock, cpu); unsigned long flags; spin_lock_irqsave(lock, flags); p->pending_ipi |= 1 << op; gsc_writel(IPI_IRQ - CPU_IRQ_BASE, p->hpa); spin_unlock_irqrestore(lock, flags); } static void send_IPI_mask(const struct cpumask *mask, enum ipi_message_type op) { int cpu; for_each_cpu(cpu, mask) ipi_send(cpu, op); } static inline void send_IPI_single(int dest_cpu, enum ipi_message_type op) { BUG_ON(dest_cpu == NO_PROC_ID); ipi_send(dest_cpu, op); } static inline void send_IPI_allbutself(enum ipi_message_type op) { int i; preempt_disable(); for_each_online_cpu(i) { if (i != smp_processor_id()) send_IPI_single(i, op); } preempt_enable(); } #ifdef CONFIG_KGDB void kgdb_roundup_cpus(void) { send_IPI_allbutself(IPI_ENTER_KGDB); } #endif inline void smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); } void arch_smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); } void smp_send_all_nop(void) { send_IPI_allbutself(IPI_NOP); } void arch_send_call_function_ipi_mask(const struct cpumask *mask) { send_IPI_mask(mask, IPI_CALL_FUNC); } void arch_send_call_function_single_ipi(int cpu) { send_IPI_single(cpu, IPI_CALL_FUNC); } /* * Called by secondaries to update state and initialize CPU registers. */ static void smp_cpu_init(int cpunum) { /* Set modes and Enable floating point coprocessor */ init_per_cpu(cpunum); disable_sr_hashing(); mb(); /* Well, support 2.4 linux scheme as well. */ if (cpu_online(cpunum)) { extern void machine_halt(void); /* arch/parisc.../process.c */ printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum); machine_halt(); } notify_cpu_starting(cpunum); set_cpu_online(cpunum, true); /* Initialise the idle task for this CPU */ mmgrab(&init_mm); current->active_mm = &init_mm; BUG_ON(current->mm); enter_lazy_tlb(&init_mm, current); init_IRQ(); /* make sure no IRQs are enabled or pending */ parisc_clockevent_init(); } /* * Slaves start using C here. Indirectly called from smp_slave_stext. * Do what start_kernel() and main() do for boot strap processor (aka monarch) */ void smp_callin(unsigned long pdce_proc) { int slave_id = cpu_now_booting; #ifdef CONFIG_64BIT WARN_ON(((unsigned long)(PAGE0->mem_pdc_hi) << 32 | PAGE0->mem_pdc) != pdce_proc); #endif smp_cpu_init(slave_id); flush_cache_all_local(); /* start with known state */ flush_tlb_all_local(NULL); local_irq_enable(); /* Interrupts have been off until now */ cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); /* NOTREACHED */ panic("smp_callin() AAAAaaaaahhhh....\n"); } /* * Bring one cpu online. */ static int smp_boot_one_cpu(int cpuid, struct task_struct *idle) { const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid); long timeout; #ifdef CONFIG_HOTPLUG_CPU int i; /* reset irq statistics for this CPU */ memset(&per_cpu(irq_stat, cpuid), 0, sizeof(irq_cpustat_t)); for (i = 0; i < NR_IRQS; i++) { struct irq_desc *desc = irq_to_desc(i); if (desc) *per_cpu_ptr(desc->kstat_irqs, cpuid) = (struct irqstat) { }; } #endif /* wait until last booting CPU has started. */ while (cpu_now_booting) ; /* Let _start know what logical CPU we're booting ** (offset into init_tasks[],cpu_data[]) */ cpu_now_booting = cpuid; /* ** boot strap code needs to know the task address since ** it also contains the process stack. */ smp_init_current_idle_task = idle ; mb(); printk(KERN_INFO "Releasing cpu %d now, hpa=%lx\n", cpuid, p->hpa); /* ** This gets PDC to release the CPU from a very tight loop. ** ** From the PA-RISC 2.0 Firmware Architecture Reference Specification: ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which ** is executed after receiving the rendezvous signal (an interrupt to ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the ** contents of memory are valid." */ gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, p->hpa); mb(); /* * OK, wait a bit for that CPU to finish staggering about. * Slave will set a bit when it reaches smp_cpu_init(). * Once the "monarch CPU" sees the bit change, it can move on. */ for (timeout = 0; timeout < 10000; timeout++) { if(cpu_online(cpuid)) { /* Which implies Slave has started up */ cpu_now_booting = 0; goto alive ; } udelay(100); barrier(); } printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid); return -1; alive: /* Remember the Slave data */ smp_debug(100, KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n", cpuid, timeout * 100); return 0; } void __init smp_prepare_boot_cpu(void) { pr_info("SMP: bootstrap CPU ID is 0\n"); } /* ** inventory.c:do_inventory() hasn't yet been run and thus we ** don't 'discover' the additional CPUs until later. */ void __init smp_prepare_cpus(unsigned int max_cpus) { int cpu; for_each_possible_cpu(cpu) spin_lock_init(&per_cpu(ipi_lock, cpu)); init_cpu_present(cpumask_of(0)); } void __init smp_cpus_done(unsigned int cpu_max) { } int __cpu_up(unsigned int cpu, struct task_struct *tidle) { if (cpu_online(cpu)) return 0; if (num_online_cpus() < nr_cpu_ids && num_online_cpus() < setup_max_cpus && smp_boot_one_cpu(cpu, tidle)) return -EIO; return cpu_online(cpu) ? 0 : -EIO; } /* * __cpu_disable runs on the processor to be shutdown. */ int __cpu_disable(void) { #ifdef CONFIG_HOTPLUG_CPU unsigned int cpu = smp_processor_id(); remove_cpu_topology(cpu); /* * Take this CPU offline. Once we clear this, we can't return, * and we must not schedule until we're ready to give up the cpu. */ set_cpu_online(cpu, false); /* Find a new timesync master */ if (cpu == time_keeper_id) { time_keeper_id = cpumask_first(cpu_online_mask); pr_info("CPU %d is now promoted to time-keeper master\n", time_keeper_id); } disable_percpu_irq(IPI_IRQ); irq_migrate_all_off_this_cpu(); flush_cache_all_local(); flush_tlb_all_local(NULL); /* disable all irqs, including timer irq */ local_irq_disable(); /* wait for next timer irq ... */ mdelay(1000/HZ+100); /* ... and then clear all pending external irqs */ set_eiem(0); mtctl(~0UL, CR_EIRR); mfctl(CR_EIRR); mtctl(0, CR_EIRR); #endif return 0; } /* * called on the thread which is asking for a CPU to be shutdown - * waits until shutdown has completed, or it is timed out. */ void __cpu_die(unsigned int cpu) { pdc_cpu_rendezvous_lock(); } void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) { pr_info("CPU%u: is shutting down\n", cpu);