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 00000000000..1794a694a92
--- /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