diff options
Diffstat (limited to 'arch/powerpc/kernel/smp.c')
-rw-r--r-- | arch/powerpc/kernel/smp.c | 573 |
1 files changed, 573 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c new file mode 100644 index 00000000000..30374d2f88e --- /dev/null +++ b/arch/powerpc/kernel/smp.c @@ -0,0 +1,573 @@ +/* + * 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/config.h> +#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 <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/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; +cpumask_t cpu_sibling_map[NR_CPUS] = { [0 ... NR_CPUS-1] = CPU_MASK_NONE }; + +EXPORT_SYMBOL(cpu_online_map); +EXPORT_SYMBOL(cpu_possible_map); + +/* SMP operations for this machine */ +struct smp_ops_t *smp_ops; + +static volatile unsigned int cpu_callin_map[NR_CPUS]; + +void smp_call_function_interrupt(void); + +int smt_enabled_at_boot = 1; + +#ifdef CONFIG_MPIC +int __init smp_mpic_probe(void) +{ + int nr_cpus; + + DBG("smp_mpic_probe()...\n"); + + nr_cpus = cpus_weight(cpu_possible_map); + + DBG("nr_cpus: %d\n", nr_cpus); + + if (nr_cpus > 1) + mpic_request_ipis(); + + return nr_cpus; +} + +void __devinit smp_mpic_setup_cpu(int cpu) +{ + mpic_setup_this_cpu(); +} +#endif /* CONFIG_MPIC */ + +#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, struct pt_regs *regs) +{ + switch(msg) { + case PPC_MSG_CALL_FUNCTION: + smp_call_function_interrupt(); + break; + case PPC_MSG_RESCHEDULE: + /* XXX Do we have to do this? */ + set_need_resched(); + break; +#ifdef CONFIG_DEBUGGER + case PPC_MSG_DEBUGGER_BREAK: + debugger_ipi(regs); + break; +#endif + default: + printk("SMP %d: smp_message_recv(): unknown msg %d\n", + smp_processor_id(), msg); + break; + } +} + +void smp_send_reschedule(int cpu) +{ + smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE); +} + +#ifdef CONFIG_DEBUGGER +void smp_send_debugger_break(int cpu) +{ + smp_ops->message_pass(cpu, 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, 1, 0); +} + +/* + * Structure and data for smp_call_function(). This is designed to minimise + * static memory requirements. It also looks cleaner. + * Stolen from the i386 version. + */ +static __cacheline_aligned_in_smp DEFINE_SPINLOCK(call_lock); + +static struct call_data_struct { + void (*func) (void *info); + void *info; + atomic_t started; + atomic_t finished; + int wait; +} *call_data; + +/* delay of at least 8 seconds */ +#define SMP_CALL_TIMEOUT 8 + +/* + * This function sends a 'generic call function' IPI to all other CPUs + * in the system. + * + * [SUMMARY] Run a function on all other CPUs. + * <func> The function to run. This must be fast and non-blocking. + * <info> An arbitrary pointer to pass to the function. + * <nonatomic> currently unused. + * <wait> If true, wait (atomically) until function has completed on other CPUs. + * [RETURNS] 0 on success, else a negative status code. Does not return until + * remote CPUs are nearly ready to execute <<func>> or are or have executed. + * + * You must not call this function with disabled interrupts or from a + * hardware interrupt handler or from a bottom half handler. + */ +int smp_call_function (void (*func) (void *info), void *info, int nonatomic, + int wait) +{ + struct call_data_struct data; + int ret = -1, cpus; + u64 timeout; + + /* Can deadlock when called with interrupts disabled */ + WARN_ON(irqs_disabled()); + + data.func = func; + data.info = info; + atomic_set(&data.started, 0); + data.wait = wait; + if (wait) + atomic_set(&data.finished, 0); + + spin_lock(&call_lock); + /* Must grab online cpu count with preempt disabled, otherwise + * it can change. */ + cpus = num_online_cpus() - 1; + if (!cpus) { + ret = 0; + goto out; + } + + call_data = &data; + smp_wmb(); + /* Send a message to all other CPUs and wait for them to respond */ + smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_CALL_FUNCTION); + + timeout = get_tb() + (u64) SMP_CALL_TIMEOUT * tb_ticks_per_sec; + + /* Wait for response */ + while (atomic_read(&data.started) != cpus) { + HMT_low(); + if (get_tb() >= timeout) { + printk("smp_call_function on cpu %d: other cpus not " + "responding (%d)\n", smp_processor_id(), + atomic_read(&data.started)); + debugger(NULL); + goto out; + } + } + + if (wait) { + while (atomic_read(&data.finished) != cpus) { + HMT_low(); + if (get_tb() >= timeout) { + printk("smp_call_function on cpu %d: other " + "cpus not finishing (%d/%d)\n", + smp_processor_id(), + atomic_read(&data.finished), + atomic_read(&data.started)); + debugger(NULL); + goto out; + } + } + } + + ret = 0; + + out: + call_data = NULL; + HMT_medium(); + spin_unlock(&call_lock); + return ret; +} + +EXPORT_SYMBOL(smp_call_function); + +void smp_call_function_interrupt(void) +{ + void (*func) (void *info); + void *info; + int wait; + + /* call_data will be NULL if the sender timed out while + * waiting on us to receive the call. + */ + if (!call_data) + return; + + func = call_data->func; + info = call_data->info; + wait = call_data->wait; + + if (!wait) + smp_mb__before_atomic_inc(); + + /* + * Notify initiating CPU that I've grabbed the data and am + * about to execute the function + */ + atomic_inc(&call_data->started); + /* + * At this point the info structure may be out of scope unless wait==1 + */ + (*func)(info); + if (wait) { + smp_mb__before_atomic_inc(); + atomic_inc(&call_data->finished); + } +} + +extern struct gettimeofday_struct do_gtod; + +struct thread_info *current_set[NR_CPUS]; + +DECLARE_PER_CPU(unsigned int, pvr); + +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; +#endif + current_set[cpu] = p->thread_info; + p->thread_info->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; + + max_cpus = smp_ops->probe(); + + smp_space_timers(max_cpus); + + for_each_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); +#ifdef CONFIG_PPC64 + paca[boot_cpuid].__current = current; +#endif + current_set[boot_cpuid] = current->thread_info; +} + +#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(); + +#ifdef CONFIG_PPC64 + flush_tlb_pending(); +#endif + cpu_set(cpu, cpu_online_map); + local_irq_enable(); +} +#endif + +static int __devinit cpu_enable(unsigned int cpu) +{ + if (smp_ops->cpu_enable) + return smp_ops->cpu_enable(cpu); + + return -ENOSYS; +} + +int __devinit __cpu_up(unsigned int cpu) +{ + int c; + + secondary_ti = current_set[cpu]; + if (!cpu_enable(cpu)) + return 0; + + if (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)) + return -EINVAL; + +#ifdef CONFIG_PPC64 + paca[cpu].default_decr = tb_ticks_per_jiffy; +#endif + + /* 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 = 5000; 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; +} + + +/* Activate a secondary processor. */ +int __devinit start_secondary(void *unused) +{ + unsigned int cpu = smp_processor_id(); + + 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(); + + spin_lock(&call_lock); + cpu_set(cpu, cpu_online_map); + spin_unlock(&call_lock); + + 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)); + + smp_ops->setup_cpu(boot_cpuid); + + set_cpus_allowed(current, old_mask); +} + +#ifdef CONFIG_HOTPLUG_CPU +int __cpu_disable(void) +{ + if (smp_ops->cpu_disable) + return smp_ops->cpu_disable(); + + return -ENOSYS; +} + +void __cpu_die(unsigned int cpu) +{ + if (smp_ops->cpu_die) + smp_ops->cpu_die(cpu); +} +#endif |