/* * SMP support for ppc. * * Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great * deal of code from the sparc and intel versions. * * Copyright (C) 1999 Cort Dougan * * PowerPC-64 Support added by Dave Engebretsen, Peter Bergner, and * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #undef DEBUG #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_PPC64 #include #endif #include #include #include #include #include #ifdef DEBUG #include #define DBG(fmt...) udbg_printf(fmt) #else #define DBG(fmt...) #endif #ifdef CONFIG_HOTPLUG_CPU /* State of each CPU during hotplug phases */ static DEFINE_PER_CPU(int, cpu_state) = { 0 }; #endif struct thread_info *secondary_ti; DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map); DEFINE_PER_CPU(cpumask_var_t, cpu_core_map); EXPORT_PER_CPU_SYMBOL(cpu_sibling_map); EXPORT_PER_CPU_SYMBOL(cpu_core_map); /* SMP operations for this machine */ struct smp_ops_t *smp_ops; /* Can't be static due to PowerMac hackery */ volatile unsigned int cpu_callin_map[NR_CPUS]; int smt_enabled_at_boot = 1; static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL; /* * Returns 1 if the specified cpu should be brought up during boot. * Used to inhibit booting threads if they've been disabled or * limited on the command line */ int smp_generic_cpu_bootable(unsigned int nr) { /* Special case - we inhibit secondary thread startup * during boot if the user requests it. */ if (system_state == SYSTEM_BOOTING && cpu_has_feature(CPU_FTR_SMT)) { if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0) return 0; if (smt_enabled_at_boot && cpu_thread_in_core(nr) >= smt_enabled_at_boot) return 0; } return 1; } #ifdef CONFIG_PPC64 int smp_generic_kick_cpu(int nr) { BUG_ON(nr < 0 || nr >= NR_CPUS); /* * The processor is currently spinning, waiting for the * cpu_start field to become non-zero After we set cpu_start, * the processor will continue on to secondary_start */ if (!paca[nr].cpu_start) { paca[nr].cpu_start = 1; smp_mb(); return 0; } #ifdef CONFIG_HOTPLUG_CPU /* * Ok it's not there, so it might be soft-unplugged, let's * try to bring it back */ generic_set_cpu_up(nr); smp_wmb(); smp_send_reschedule(nr); #endif /* CONFIG_HOTPLUG_CPU */ return 0; } #endif /* CONFIG_PPC64 */ static irqreturn_t call_function_action(int irq, void *data) { generic_smp_call_function_interrupt(); return IRQ_HANDLED; } static irqreturn_t reschedule_action(int irq, void *data) { scheduler_ipi(); return IRQ_HANDLED; } static irqreturn_t tick_broadcast_ipi_action(int irq, void *data) { tick_broadcast_ipi_handler(); return IRQ_HANDLED; } static irqreturn_t debug_ipi_action(int irq, void *data) { if (crash_ipi_function_ptr) { crash_ipi_function_ptr(get_irq_regs()); return IRQ_HANDLED; } #ifdef CONFIG_DEBUGGER debugger_ipi(get_irq_regs()); #endif /* CONFIG_DEBUGGER */ return IRQ_HANDLED; } static irq_handler_t smp_ipi_action[] = { [PPC_MSG_CALL_FUNCTION] = call_function_action, [PPC_MSG_RESCHEDULE] = reschedule_action, [PPC_MSG_TICK_BROADCAST] = tick_broadcast_ipi_action, [PPC_MSG_DEBUGGER_BREAK] = debug_ipi_action, }; const char *smp_ipi_name[] = { [PPC_MSG_CALL_FUNCTION] = "ipi call function", [PPC_MSG_RESCHEDULE] = "ipi reschedule", [PPC_MSG_TICK_BROADCAST] = "ipi tick-broadcast", [PPC_MSG_DEBUGGER_BREAK] = "ipi debugger", }; /* optional function to request ipi, for controllers with >= 4 ipis */ int smp_request_message_ipi(int virq, int msg) { int err; if (msg < 0 || msg > PPC_MSG_DEBUGGER_BREAK) { return -EINVAL; } #if !defined(CONFIG_DEBUGGER) && !defined(CONFIG_KEXEC) if (msg == PPC_MSG_DEBUGGER_BREAK) { return 1; } #endif err = request_irq(virq, smp_ipi_action[msg], IRQF_PERCPU | IRQF_NO_THREAD | IRQF_NO_SUSPEND, smp_ipi_name[msg], NULL); WARN(err < 0, "unable to request_irq %d for %s (rc %d)\n", virq, smp_ipi_name[msg], err); return err; } #ifdef CONFIG_PPC_SMP_MUXED_IPI struct cpu_messages { long messages; /* current messages */ unsigned long data; /* data for cause ipi */ }; static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_messages, ipi_message); void smp_muxed_ipi_set_data(int cpu, unsigned long data) { struct cpu_messages *info = &per_cpu(ipi_message, cpu); info->data = data; } void smp_muxed_ipi_set_message(int cpu, int msg) { struct cpu_messages *info = &per_cpu(ipi_message, cpu); char *message = (char *)&info->messages; /* * Order previous accesses before accesses in the IPI handler. */ smp_mb(); message[msg] = 1; } void smp_muxed_ipi_message_pass(int cpu, int msg) { struct cpu_messages *info = &per_cpu(ipi_message, cpu); smp_muxed_ipi_set_message(cpu, msg); /* * cause_ipi functions are required to include a full barrier * before doing whatever causes the IPI. */ smp_ops->cause_ipi(cpu, info->data); } #ifdef __BIG_ENDIAN__ #define IPI_MESSAGE(A) (1uL << ((BITS_PER_LONG - 8) - 8 * (A))) #else #define IPI_MESSAGE(A) (1uL << (8 * (A))) #endif irqreturn_t smp_ipi_demux(void) { struct cpu_messages *info = this_cpu_ptr(&ipi_message); unsigned long all; mb(); /* order any irq clear */ do { all = xchg(&info->messages, 0); #if defined(CONFIG_KVM_XICS) && defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) /* * Must check for PPC_MSG_RM_HOST_ACTION messages * before PPC_MSG_CALL_FUNCTION messages because when * a VM is destroyed, we call kick_all_cpus_sync() * to ensure that any pending PPC_MSG_RM_HOST_ACTION * messages have completed before we free any VCPUs. */ if (all & IPI_MESSAGE(PPC_MSG_RM_HOST_ACTION)) kvmppc_xics_ipi_action(); #endif if (all & IPI_MESSAGE(PPC_MSG_CALL_FUNCTION)) generic_smp_call_function_interrupt(); if (all & IPI_MESSAGE(PPC_MSG_RESCHEDULE)) scheduler_ipi(); if (all & IPI_MESSAGE(PPC_MSG_TICK_BROADCAST)) tick_broadcast_ipi_handler(); if (all & IPI_MESSAGE(PPC_MSG_DEBUGGER_BREAK)) debug_ipi_action(0, NULL); } while (info->messages); return IRQ_HANDLED; } #endif /* CONFIG_PPC_SMP_MUXED_IPI */ static inline void do_message_pass(int cpu, int msg) { if (smp_ops->message_pass) smp_ops->message_pass(cpu, msg); #ifdef CONFIG_PPC_SMP_MUXED_IPI else smp_muxed_ipi_message_pass(cpu, msg); #endif } void smp_send_reschedule(int cpu) { if (likely(smp_ops)) do_message_pass(cpu, PPC_MSG_RESCHEDULE); } EXPORT_SYMBOL_GPL(smp_send_reschedule); void arch_send_call_function_single_ipi(int cpu) { do_message_pass(cpu, PPC_MSG_CALL_FUNCTION); } void arch_send_call_function_ipi_mask(const struct cpumask *mask) { unsigned int cpu; for_each_cpu(cpu, mask) do_message_pass(cpu, PPC_MSG_CALL_FUNCTION); } #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST void tick_broadcast(const struct cpumask *mask) { unsigned int cpu; for_each_cpu(cpu, mask) do_message_pass(cpu, PPC_MSG_TICK_BROADCAST); } #endif #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC) void smp_send_debugger_break(void) { int cpu; int me = raw_smp_processor_id(); if (unlikely(!smp_ops)) return; for_each_online_cpu(cpu) if (cpu != me) do_message_pass(cpu, PPC_MSG_DEBUGGER_BREAK); } #endif #ifdef CONFIG_KEXEC void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *)) { crash_ipi_function_ptr = crash_ipi_callback; if (crash_ipi_callback) { mb(); smp_send_debugger_break(); } } #endif static void stop_this_cpu(void *dummy) { /* Remove this CPU */ set_cpu_online(smp_processor_id(), false); local_irq_disable(); while (1) ; } void smp_send_stop(void) { smp_call_function(stop_this_cpu, NULL, 0); } struct thread_info *current_set[NR_CPUS]; static void smp_store_cpu_info(int id) { per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR); #ifdef CONFIG_PPC_FSL_BOOK3E per_cpu(next_tlbcam_idx, id) = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1; #endif } void __init smp_prepare_cpus(unsigned int max_cpus) { unsigned int cpu; DBG("smp_prepare_cpus\n"); /* * setup_cpu may need to be called on the boot cpu. We havent * spun any cpus up but lets be paranoid. */ BUG_ON(boot_cpuid != smp_processor_id()); /* Fixup boot cpu */ smp_store_cpu_info(boot_cpuid); cpu_callin_map[boot_cpuid] = 1; for_each_possible_cpu(cpu) { zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu), GFP_KERNEL, cpu_to_node(cpu)); zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu), GFP_KERNEL, cpu_to_node(cpu)); /* * numa_node_id() works after this. */ if (cpu_present(cpu)) { set_cpu_numa_node(cpu, numa_cpu_lookup_table[cpu]); set_cpu_numa_mem(cpu, local_memory_node(numa_cpu_lookup_table[cpu])); } } cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid)); cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid)); if (smp_ops && smp_ops->probe) smp_ops->probe(); } void smp_prepare_boot_cpu(void) { BUG_ON(smp_processor_id() != boot_cpuid); #ifdef CONFIG_PPC64 paca[boot_cpuid].__current = current; #endif set_numa_node(numa_cpu_lookup_table[boot_cpuid]); current_set[boot_cpuid] = task_thread_info(current); } #ifdef CONFIG_HOTPLUG_CPU int generic_cpu_disable(void) { unsigned int cpu = smp_processor_id(); if (cpu == boot_cpuid) return -EBUSY; set_cpu_online(cpu, false); #ifdef CONFIG_PPC64 vdso_data->processorCount--; #endif migrate_irqs(); return 0; } void generic_cpu_die(unsigned int cpu) { int i; for (i = 0; i < 100; i++) { smp_rmb(); if (is_cpu_dead(cpu)) return; msleep(100); } printk(KERN_ERR "CPU%d didn't die...\n", cpu); } void generic_set_cpu_dead(unsigned int cpu) { per_cpu(cpu_state, cpu) = CPU_DEAD; } /* * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(), * which makes the delay in generic_cpu_die() not happen. */ void generic_set_cpu_up(unsigned int cpu) { per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; } int generic_check_cpu_restart(unsigned int cpu) { return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE; } int is_cpu_dead(unsigned int cpu) { return per_cpu(cpu_state, cpu) == CPU_DEAD; } static bool secondaries_inhibited(void) { return kvm_hv_mode_active(); } #else /* HOTPLUG_CPU */ #define secondaries_inhibited() 0 #endif static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle) { struct thread_info *ti = task_thread_info(idle); #ifdef CONFIG_PPC64 paca[cpu].__current = idle; paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD; #endif ti->cpu = cpu; secondary_ti = current_set[cpu] = ti; } int __cpu_up(unsigned int cpu, struct task_struct *tidle) { int rc, c; /* * Don't allow secondary threads to come online if inhibited */ if (threads_per_core > 1 && secondaries_inhibited() && cpu_thread_in_subcore(cpu)) return -EBUSY; if (smp_ops == NULL || (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu))) return -EINVAL; cpu_idle_thread_init(cpu, tidle); /* Make sure callin-map entry is 0 (can be leftover a CPU * hotplug */ cpu_callin_map[cpu] = 0; /* The information for processor bringup must * be written out to main store before we release * the processor. */ smp_mb(); /* wake up cpus */ DBG("smp: kicking cpu %d\n", cpu); rc = smp_ops->kick_cpu(cpu); if (rc) { pr_err("smp: failed starting cpu %d (rc %d)\n", cpu, rc); return rc; } /* * wait to see if the cpu made a callin (is actually up). * use this value that I found through experimentation. * -- Cort */ if (system_state < SYSTEM_RUNNING) for (c = 50000; c && !cpu_callin_map[cpu]; c--) udelay(100); #ifdef CONFIG_HOTPLUG_CPU else /* * CPUs can take much longer to come up in the * hotplug case. Wait five seconds. */ for (c = 5000; c && !cpu_callin_map[cpu]; c--) msleep(1); #endif if (!cpu_callin_map[cpu]) { printk(KERN_ERR "Processor %u is stuck.\n", cpu); return -ENOENT; } DBG("Processor %u found.\n", cpu); if (smp_ops->give_timebase) smp_ops->give_timebase(); /* Wait until cpu puts itself in the online & active maps */ while (!cpu_online(cpu)) cpu_relax(); return 0; } /* Return the value of the reg property corresponding to the given * logical cpu. */ int cpu_to_core_id(int cpu) { struct device_node *np; const __be32 *reg; int id = -1; np = of_get_cpu_node(cpu, NULL); if (!np) goto out; reg = of_get_property(np, "reg", NULL); if (!reg) goto out; id = be32_to_cpup(reg); out: of_node_put(np); return id; } EXPORT_SYMBOL_GPL(cpu_to_core_id); /* Helper routines for cpu to core mapping */ int cpu_core_index_of_thread(int cpu) { return cpu >> threads_shift; } EXPORT_SYMBOL_GPL(cpu_core_index_of_thread); int cpu_first_thread_of_core(int core) { return core << threads_shift; } EXPORT_SYMBOL_GPL(cpu_first_thread_of_core); static void traverse_siblings_chip_id(int cpu, bool add, int chipid) { const struct cpumask *mask; struct device_node *np; int i, plen; const __be32 *prop; mask = add ? cpu_online_mask : cpu_present_mask; for_each_cpu(i, mask) { np = of_get_cpu_node(i, NULL); if (!np) continue; prop = of_get_property(np, "ibm,chip-id", &plen); if (prop && plen == sizeof(int) && of_read_number(prop, 1) == chipid) { if (add) { cpumask_set_cpu(cpu, cpu_core_mask(i)); cpumask_set_cpu(i, cpu_core_mask(cpu)); } else { cpumask_clear_cpu(cpu, cpu_core_mask(i)); cpumask_clear_cpu(i, cpu_core_mask(cpu)); } } of_node_put(np); } } /* Must be called when no change can occur to cpu_present_mask, * i.e. during cpu online or offline. */ static struct device_node *cpu_to_l2cache(int cpu) { struct device_node *np; struct device_node *cache; if (!cpu_present(cpu)) return NULL; np = of_get_cpu_node(cpu, NULL); if (np == NULL) return NULL; cache = of_find_next_cache_node(np); of_node_put(np); return cache; } static void traverse_core_siblings(int cpu, bool add) { struct device_node *l2_cache, *np; const struct cpumask *mask; int i, chip, plen; const __be32 *prop; /* First see if we have ibm,chip-id properties in cpu nodes */ np = of_get_cpu_node(cpu, NULL); if (np) { chip = -1; prop = of_get_property(np, "ibm,chip-id", &plen); if (prop && plen == sizeof(int)) chip = of_read_number(prop, 1); of_node_put(np); if (chip >= 0) { traverse_siblings_chip_id(cpu, add, chip); return; } } l2_cache = cpu_to_l2cache(cpu); mask = add ? cpu_online_mask : cpu_present_mask; for_each_cpu(i, mask) { np = cpu_to_l2cache(i); if (!np) continue; if (np == l2_cache) { if (add) { cpumask_set_cpu(cpu, cpu_core_mask(i)); cpumask_set_cpu(i, cpu_core_mask(cpu)); } else { cpumask_clear_cpu(cpu, cpu_core_mask(i)); cpumask_clear_cpu(i, cpu_core_mask(cpu)); } } of_node_put(np); } of_node_put(l2_cache); } /* Activate a secondary processor. */ void start_secondary(void *unused) { unsigned int cpu = smp_processor_id(); int i, base; atomic_inc(&init_mm.mm_count); current->active_mm = &init_mm; smp_store_cpu_info(cpu); set_dec(tb_ticks_per_jiffy); preempt_disable(); cpu_callin_map[cpu] = 1; if (smp_ops->setup_cpu) smp_ops->setup_cpu(cpu); if (smp_ops->take_timebase) smp_ops->take_timebase(); secondary_cpu_time_init(); #ifdef CONFIG_PPC64 if (system_state == SYSTEM_RUNNING) vdso_data->processorCount++; vdso_getcpu_init(); #endif /* Update sibling maps */ base = cpu_first_thread_sibling(cpu); for (i = 0; i < threads_per_core; i++) { if (cpu_is_offline(base + i) && (cpu != base + i)) continue; cpumask_set_cpu(cpu, cpu_sibling_mask(base + i)); cpumask_set_cpu(base + i, cpu_sibling_mask(cpu)); /* cpu_core_map should be a superset of * cpu_sibling_map even if we don't have cache * information, so update the former here, too. */ cpumask_set_cpu(cpu, cpu_core_mask(base + i)); cpumask_set_cpu(base + i, cpu_core_mask(cpu)); } traverse_core_siblings(cpu, true); set_numa_node(numa_cpu_lookup_table[cpu]); set_numa_mem(local_memory_node(numa_cpu_lookup_table[cpu])); smp_wmb(); notify_cpu_starting(cpu); set_cpu_online(cpu, true); local_irq_enable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); BUG(); } #ifdef CONFIG_PROFILING int setup_profiling_timer(unsigned int multiplier) { return 0; } #endif #ifdef CONFIG_SCHED_SMT /* cpumask of CPUs with asymetric SMT dependancy */ static int powerpc_smt_flags(void) { int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES; if (cpu_has_feature(CPU_FTR_ASYM_SMT)) { printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n"); flags |= SD_ASYM_PACKING; } return flags; } #endif static struct sched_domain_topology_level powerpc_topology[] = { #ifdef CONFIG_SCHED_SMT { cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) }, #endif { cpu_cpu_mask, SD_INIT_NAME(DIE) }, { NULL, }, }; void __init smp_cpus_done(unsigned int max_cpus) { cpumask_var_t old_mask; /* We want the setup_cpu() here to be called from CPU 0, but our * init thread may have been "borrowed" by another CPU in the meantime * se we pin us down to CPU 0 for a short while */ alloc_cpumask_var(&old_mask, GFP_NOWAIT); cpumask_copy(old_mask, tsk_cpus_allowed(current)); set_cpus_allowed_ptr(current, cpumask_of(boot_cpuid)); if (smp_ops && smp_ops->setup_cpu) smp_ops->setup_cpu(boot_cpuid); set_cpus_allowed_ptr(current, old_mask); free_cpumask_var(old_mask); if (smp_ops && smp_ops->bringup_done) smp_ops->bringup_done(); dump_numa_cpu_topology(); set_sched_topology(powerpc_topology); } #ifdef CONFIG_HOTPLUG_CPU int __cpu_disable(void) { int cpu = smp_processor_id(); int base, i; int err; if (!smp_ops->cpu_disable) return -ENOSYS; err = smp_ops->cpu_disable(); if (err) return err; /* Update sibling maps */ base = cpu_first_thread_sibling(cpu); for (i = 0; i < threads_per_core && base + i < nr_cpu_ids; i++) { cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i)); cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu)); cpumask_clear_cpu(cpu, cpu_core_mask(base + i)); cpumask_clear_cpu(base + i, cpu_core_mask(cpu)); } traverse_core_siblings(cpu, false); return 0; } void __cpu_die(unsigned int cpu) { if (smp_ops->cpu_die) smp_ops->cpu_die(cpu); } void cpu_die(void) { if (ppc_md.cpu_die) ppc_md.cpu_die(); /* If we return, we re-enter start_secondary */ start_secondary_resume(); } #endif