1 files changed, 565 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
new file mode 100644
index 000000000000..1794a694a928
--- /dev/null
+++ b/arch/powerpc/kernel/smp.c
@@ -0,0 +1,565 @@
+/*
+ * 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/xmon.h>
+#include <asm/machdep.h>
+#include <asm/cputable.h>
+#include <asm/system.h>
+#include <asm/mpic.h>
+#ifdef CONFIG_PPC64
+#include <asm/paca.h>
+#endif
+
+int smp_hw_index[NR_CPUS];
+struct thread_info *secondary_ti;
+
+#ifdef DEBUG
+#define DBG(fmt...) udbg_printf(fmt)
+#else
+#define DBG(fmt...)
+#endif
+
+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;
+
+        systemcfg->processorCount--;
+        cpu_clear(cpu, cpu_online_map);
+        fixup_irqs(cpu_online_map);
+        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();
+
+        fixup_irqs(cpu_online_map);
+        /* counter the irq disable in fixup_irqs */
+        local_irq_enable();
+        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();
+
+        flush_tlb_pending();
+        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);
+        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