/* * 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 <cort@cs.nmt.edu> * * 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 <linux/kernel.h> #include <linux/module.h> #include <linux/sched.h> #include <linux/smp.h> #include <linux/interrupt.h> #include <linux/delay.h> #include <linux/init.h> #include <linux/spinlock.h> #include <linux/cache.h> #include <linux/err.h> #include <linux/sysdev.h> #include <linux/cpu.h> #include <linux/notifier.h> #include <linux/topology.h> #include <asm/ptrace.h> #include <asm/atomic.h> #include <asm/irq.h> #include <asm/page.h> #include <asm/pgtable.h> #include <asm/prom.h> #include <asm/smp.h> #include <asm/time.h> #include <asm/machdep.h> #include <asm/cputhreads.h> #include <asm/cputable.h> #include <asm/system.h> #include <asm/mpic.h> #include <asm/vdso_datapage.h> #ifdef CONFIG_PPC64 #include <asm/paca.h> #endif #ifdef DEBUG #include <asm/udbg.h> #define DBG(fmt...) udbg_printf(fmt) #else #define DBG(fmt...) #endif int smp_hw_index[NR_CPUS]; struct thread_info *secondary_ti; cpumask_t cpu_possible_map = CPU_MASK_NONE; cpumask_t cpu_online_map = CPU_MASK_NONE; DEFINE_PER_CPU(cpumask_t, cpu_sibling_map) = CPU_MASK_NONE; DEFINE_PER_CPU(cpumask_t, cpu_core_map) = CPU_MASK_NONE; EXPORT_SYMBOL(cpu_online_map); EXPORT_SYMBOL(cpu_possible_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; static volatile unsigned int cpu_callin_map[NR_CPUS]; int smt_enabled_at_boot = 1; static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL; #ifdef CONFIG_PPC64 void __devinit 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 */ paca[nr].cpu_start = 1; smp_mb(); } #endif void smp_message_recv(int msg) { switch(msg) { case PPC_MSG_CALL_FUNCTION: generic_smp_call_function_interrupt(); break; case PPC_MSG_RESCHEDULE: /* XXX Do we have to do this? */ set_need_resched(); break; case PPC_MSG_CALL_FUNC_SINGLE: generic_smp_call_function_single_interrupt(); break; case PPC_MSG_DEBUGGER_BREAK: if (crash_ipi_function_ptr) { crash_ipi_function_ptr(get_irq_regs()); break; } #ifdef CONFIG_DEBUGGER debugger_ipi(get_irq_regs()); break; #endif /* CONFIG_DEBUGGER */ /* FALLTHROUGH */ default: printk("SMP %d: smp_message_recv(): unknown msg %d\n", smp_processor_id(), msg); break; } } void smp_send_reschedule(int cpu) { if (likely(smp_ops)) smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE); } void arch_send_call_function_single_ipi(int cpu) { smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNC_SINGLE); } void arch_send_call_function_ipi(cpumask_t mask) { unsigned int cpu; for_each_cpu_mask(cpu, mask) smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNCTION); } #ifdef CONFIG_DEBUGGER void smp_send_debugger_break(int cpu) { if (likely(smp_ops)) smp_ops->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 && smp_ops) { mb(); smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_DEBUGGER_BREAK); } } #endif static void stop_this_cpu(void *dummy) { 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 __devinit smp_store_cpu_info(int id) { per_cpu(pvr, id) = mfspr(SPRN_PVR); } static void __init smp_create_idle(unsigned int cpu) { struct task_struct *p; /* create a process for the processor */ p = fork_idle(cpu); if (IS_ERR(p)) panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p)); #ifdef CONFIG_PPC64 paca[cpu].__current = p; paca[cpu].kstack = (unsigned long) task_thread_info(p) + THREAD_SIZE - STACK_FRAME_OVERHEAD; #endif current_set[cpu] = task_thread_info(p); task_thread_info(p)->cpu = cpu; } 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; if (smp_ops) max_cpus = smp_ops->probe(); else max_cpus = 1; smp_space_timers(max_cpus); for_each_possible_cpu(cpu) if (cpu != boot_cpuid) smp_create_idle(cpu); } void __devinit smp_prepare_boot_cpu(void) { BUG_ON(smp_processor_id() != boot_cpuid); cpu_set(boot_cpuid, cpu_online_map); cpu_set(boot_cpuid, per_cpu(cpu_sibling_map, boot_cpuid)); cpu_set(boot_cpuid, per_cpu(cpu_core_map, boot_cpuid)); #ifdef CONFIG_PPC64 paca[boot_cpuid].__current = current; #endif current_set[boot_cpuid] = task_thread_info(current); } #ifdef CONFIG_HOTPLUG_CPU /* State of each CPU during hotplug phases */ DEFINE_PER_CPU(int, cpu_state) = { 0 }; int generic_cpu_disable(void) { unsigned int cpu = smp_processor_id(); if (cpu == boot_cpuid) return -EBUSY; cpu_clear(cpu, cpu_online_map); #ifdef CONFIG_PPC64 vdso_data->processorCount--; fixup_irqs(cpu_online_map); #endif return 0; } int generic_cpu_enable(unsigned int cpu) { /* Do the normal bootup if we haven't * already bootstrapped. */ if (system_state != SYSTEM_RUNNING) return -ENOSYS; /* get the target out of it's holding state */ per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; smp_wmb(); while (!cpu_online(cpu)) cpu_relax(); #ifdef CONFIG_PPC64 fixup_irqs(cpu_online_map); /* counter the irq disable in fixup_irqs */ local_irq_enable(); #endif return 0; } void generic_cpu_die(unsigned int cpu) { int i; for (i = 0; i < 100; i++) { smp_rmb(); if (per_cpu(cpu_state, cpu) == CPU_DEAD) return; msleep(100); } printk(KERN_ERR "CPU%d didn't die...\n", cpu); } void generic_mach_cpu_die(void) { unsigned int cpu; local_irq_disable(); cpu = smp_processor_id(); printk(KERN_DEBUG "CPU%d offline\n", cpu); __get_cpu_var(cpu_state) = CPU_DEAD; smp_wmb(); while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE) cpu_relax(); cpu_set(cpu, cpu_online_map); local_irq_enable(); } #endif static int __devinit cpu_enable(unsigned int cpu) { if (smp_ops && smp_ops->cpu_enable) return smp_ops->cpu_enable(cpu); return -ENOSYS; } int __cpuinit __cpu_up(unsigned int cpu) { int c; secondary_ti = current_set[cpu]; if (!cpu_enable(cpu)) return 0; if (smp_ops == NULL || (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu))) return -EINVAL; /* 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); smp_ops->kick_cpu(cpu); /* * 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 = 25; c && !cpu_callin_map[cpu]; c--) { msleep(200); } #endif if (!cpu_callin_map[cpu]) { printk("Processor %u is stuck.\n", cpu); return -ENOENT; } printk("Processor %u found.\n", cpu); if (smp_ops->give_timebase) smp_ops->give_timebase(); /* Wait until cpu puts itself in the online map */ 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 int *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 = *reg; out: of_node_put(np); return id; } /* Must be called when no change can occur to cpu_present_map, * i.e. during cpu online or offline. */ static struct device_node *cpu_to_l2cache(int cpu) { struct device_node *np; const phandle *php; phandle ph; if (!cpu_present(cpu)) return NULL; np = of_get_cpu_node(cpu, NULL); if (np == NULL) return NULL; php = of_get_property(np, "l2-cache", NULL); if (php == NULL) return NULL; ph = *php; of_node_put(np); return of_find_node_by_phandle(ph); } /* Activate a secondary processor. */ int __devinit start_secondary(void *unused) { unsigned int cpu = smp_processor_id(); struct device_node *l2_cache; 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; smp_ops->setup_cpu(cpu); if (smp_ops->take_timebase) smp_ops->take_timebase(); if (system_state > SYSTEM_BOOTING) snapshot_timebase(); secondary_cpu_time_init(); ipi_call_lock(); cpu_set(cpu, cpu_online_map); /* Update sibling maps */ base = cpu_first_thread_in_core(cpu); for (i = 0; i < threads_per_core; i++) { if (cpu_is_offline(base + i)) continue; cpu_set(cpu, per_cpu(cpu_sibling_map, base + i)); cpu_set(base + i, per_cpu(cpu_sibling_map, 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. */ cpu_set(cpu, per_cpu(cpu_core_map, base +i)); cpu_set(base + i, per_cpu(cpu_core_map, cpu)); } l2_cache = cpu_to_l2cache(cpu); for_each_online_cpu(i) { struct device_node *np = cpu_to_l2cache(i); if (!np) continue; if (np == l2_cache) { cpu_set(cpu, per_cpu(cpu_core_map, i)); cpu_set(i, per_cpu(cpu_core_map, cpu)); } of_node_put(np); } of_node_put(l2_cache); ipi_call_unlock(); local_irq_enable(); cpu_idle(); return 0; } int setup_profiling_timer(unsigned int multiplier) { return 0; } void __init smp_cpus_done(unsigned int max_cpus) { cpumask_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 */ old_mask = current->cpus_allowed; set_cpus_allowed(current, cpumask_of_cpu(boot_cpuid)); if (smp_ops) smp_ops->setup_cpu(boot_cpuid); set_cpus_allowed(current, old_mask); snapshot_timebases(); dump_numa_cpu_topology(); } #ifdef CONFIG_HOTPLUG_CPU int __cpu_disable(void) { struct device_node *l2_cache; 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_in_core(cpu); for (i = 0; i < threads_per_core; i++) { cpu_clear(cpu, per_cpu(cpu_sibling_map, base + i)); cpu_clear(base + i, per_cpu(cpu_sibling_map, cpu)); cpu_clear(cpu, per_cpu(cpu_core_map, base +i)); cpu_clear(base + i, per_cpu(cpu_core_map, cpu)); } l2_cache = cpu_to_l2cache(cpu); for_each_present_cpu(i) { struct device_node *np = cpu_to_l2cache(i); if (!np) continue; if (np == l2_cache) { cpu_clear(cpu, per_cpu(cpu_core_map, i)); cpu_clear(i, per_cpu(cpu_core_map, cpu)); } of_node_put(np); } of_node_put(l2_cache); return 0; } void __cpu_die(unsigned int cpu) { if (smp_ops->cpu_die) smp_ops->cpu_die(cpu); } #endif