diff options
Diffstat (limited to 'arch/powerpc/kernel/smp.c')
| -rw-r--r-- | arch/powerpc/kernel/smp.c | 785 |
1 files changed, 785 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c new file mode 100644 index 00000000..d9f94410 --- /dev/null +++ b/arch/powerpc/kernel/smp.c @@ -0,0 +1,785 @@ +/* + * 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/export.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/device.h> +#include <linux/cpu.h> +#include <linux/notifier.h> +#include <linux/topology.h> + +#include <asm/ptrace.h> +#include <linux/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/mpic.h> +#include <asm/vdso_datapage.h> +#ifdef CONFIG_PPC64 +#include <asm/paca.h> +#endif +#include <asm/debug.h> + +#ifdef DEBUG +#include <asm/udbg.h> +#define DBG(fmt...) udbg_printf(fmt) +#else +#define DBG(fmt...) +#endif + + +/* Store all idle threads, this can be reused instead of creating +* a new thread. Also avoids complicated thread destroy functionality +* for idle threads. +*/ +#ifdef CONFIG_HOTPLUG_CPU +/* + * Needed only for CONFIG_HOTPLUG_CPU because __cpuinitdata is + * removed after init for !CONFIG_HOTPLUG_CPU. + */ +static DEFINE_PER_CPU(struct task_struct *, idle_thread_array); +#define get_idle_for_cpu(x) (per_cpu(idle_thread_array, x)) +#define set_idle_for_cpu(x, p) (per_cpu(idle_thread_array, x) = (p)) + +/* State of each CPU during hotplug phases */ +static DEFINE_PER_CPU(int, cpu_state) = { 0 }; + +#else +static struct task_struct *idle_thread_array[NR_CPUS] __cpuinitdata ; +#define get_idle_for_cpu(x) (idle_thread_array[(x)]) +#define set_idle_for_cpu(x, p) (idle_thread_array[(x)] = (p)) +#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; + +#ifdef CONFIG_PPC64 +int __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 + */ + 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 + */ + per_cpu(cpu_state, nr) = CPU_UP_PREPARE; + 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 call_function_single_action(int irq, void *data) +{ + generic_smp_call_function_single_interrupt(); + 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_CALL_FUNC_SINGLE] = call_function_single_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_CALL_FUNC_SINGLE] = "ipi call function single", + [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, + smp_ipi_name[msg], 0); + 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 { + int 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_message_pass(int cpu, int msg) +{ + struct cpu_messages *info = &per_cpu(ipi_message, cpu); + char *message = (char *)&info->messages; + + message[msg] = 1; + mb(); + smp_ops->cause_ipi(cpu, info->data); +} + +irqreturn_t smp_ipi_demux(void) +{ + struct cpu_messages *info = &__get_cpu_var(ipi_message); + unsigned int all; + + mb(); /* order any irq clear */ + + do { + all = xchg_local(&info->messages, 0); + +#ifdef __BIG_ENDIAN + if (all & (1 << (24 - 8 * PPC_MSG_CALL_FUNCTION))) + generic_smp_call_function_interrupt(); + if (all & (1 << (24 - 8 * PPC_MSG_RESCHEDULE))) + scheduler_ipi(); + if (all & (1 << (24 - 8 * PPC_MSG_CALL_FUNC_SINGLE))) + generic_smp_call_function_single_interrupt(); + if (all & (1 << (24 - 8 * PPC_MSG_DEBUGGER_BREAK))) + debug_ipi_action(0, NULL); +#else +#error Unsupported ENDIAN +#endif + } 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_FUNC_SINGLE); +} + +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); +} + +#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 __devinit 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)); + } + + cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid)); + cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid)); + + if (smp_ops) + if (smp_ops->probe) + max_cpus = smp_ops->probe(); + else + max_cpus = NR_CPUS; + else + max_cpus = 1; +} + +void __devinit smp_prepare_boot_cpu(void) +{ + BUG_ON(smp_processor_id() != boot_cpuid); +#ifdef CONFIG_PPC64 + paca[boot_cpuid].__current = current; +#endif + 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 (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(); + idle_task_exit(); + 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(); +} + +void generic_set_cpu_dead(unsigned int cpu) +{ + per_cpu(cpu_state, cpu) = CPU_DEAD; +} + +int generic_check_cpu_restart(unsigned int cpu) +{ + return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE; +} +#endif + +struct create_idle { + struct work_struct work; + struct task_struct *idle; + struct completion done; + int cpu; +}; + +static void __cpuinit do_fork_idle(struct work_struct *work) +{ + struct create_idle *c_idle = + container_of(work, struct create_idle, work); + + c_idle->idle = fork_idle(c_idle->cpu); + complete(&c_idle->done); +} + +static int __cpuinit create_idle(unsigned int cpu) +{ + struct thread_info *ti; + struct create_idle c_idle = { + .cpu = cpu, + .done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done), + }; + INIT_WORK_ONSTACK(&c_idle.work, do_fork_idle); + + c_idle.idle = get_idle_for_cpu(cpu); + + /* We can't use kernel_thread since we must avoid to + * reschedule the child. We use a workqueue because + * we want to fork from a kernel thread, not whatever + * userspace process happens to be trying to online us. + */ + if (!c_idle.idle) { + schedule_work(&c_idle.work); + wait_for_completion(&c_idle.done); + } else + init_idle(c_idle.idle, cpu); + if (IS_ERR(c_idle.idle)) { + pr_err("Failed fork for CPU %u: %li", cpu, PTR_ERR(c_idle.idle)); + return PTR_ERR(c_idle.idle); + } + ti = task_thread_info(c_idle.idle); + +#ifdef CONFIG_PPC64 + paca[cpu].__current = c_idle.idle; + paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD; +#endif + ti->cpu = cpu; + current_set[cpu] = ti; + + return 0; +} + +int __cpuinit __cpu_up(unsigned int cpu) +{ + int rc, c; + + if (smp_ops == NULL || + (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu))) + return -EINVAL; + + /* Make sure we have an idle thread */ + rc = create_idle(cpu); + if (rc) + return rc; + + secondary_ti = current_set[cpu]; + + /* 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 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; +} + +/* 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); + +/* 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; +} + +/* Activate a secondary processor. */ +void __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; + + 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++; +#endif + ipi_call_lock(); + notify_cpu_starting(cpu); + set_cpu_online(cpu, true); + /* Update sibling maps */ + base = cpu_first_thread_sibling(cpu); + for (i = 0; i < threads_per_core; i++) { + if (cpu_is_offline(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)); + } + 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) { + cpumask_set_cpu(cpu, cpu_core_mask(i)); + cpumask_set_cpu(i, cpu_core_mask(cpu)); + } + of_node_put(np); + } + of_node_put(l2_cache); + ipi_call_unlock(); + + local_irq_enable(); + + cpu_idle(); + + BUG(); +} + +int setup_profiling_timer(unsigned int multiplier) +{ + return 0; +} + +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(); + +} + +int arch_sd_sibling_asym_packing(void) +{ + if (cpu_has_feature(CPU_FTR_ASYM_SMT)) { + printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n"); + return SD_ASYM_PACKING; + } + return 0; +} + +#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_sibling(cpu); + for (i = 0; i < threads_per_core; 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)); + } + + 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) { + 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); + + + return 0; +} + +void __cpu_die(unsigned int cpu) +{ + if (smp_ops->cpu_die) + smp_ops->cpu_die(cpu); +} + +static DEFINE_MUTEX(powerpc_cpu_hotplug_driver_mutex); + +void cpu_hotplug_driver_lock() +{ + mutex_lock(&powerpc_cpu_hotplug_driver_mutex); +} + +void cpu_hotplug_driver_unlock() +{ + mutex_unlock(&powerpc_cpu_hotplug_driver_mutex); +} + +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 |