initial_commit

1 files changed, 757 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
new file mode 100644
index 00000000..8ebc6700
--- /dev/null
+++ b/arch/powerpc/kernel/smp.c
@@ -0,0 +1,757 @@
+/*
+ * 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
+
+
+/* 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))
+#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
+	 */
+	paca[nr].cpu_start = 1;
+	smp_mb();
+
+	return 0;
+}
+#endif
+
+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_DISABLED|IRQF_PERCPU,
+			  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);
+}
+
+void smp_muxed_ipi_resend(void)
+{
+	struct cpu_messages *info = &__get_cpu_var(ipi_message);
+
+	if (info->messages)
+		smp_ops->cause_ipi(smp_processor_id(), 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 */
+
+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_mask(const struct cpumask *mask)
+{
+	unsigned int cpu;
+
+	for_each_cpu(cpu, mask)
+		smp_ops->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)
+			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) {
+		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);
+}
+
+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
+/* State of each CPU during hotplug phases */
+static DEFINE_PER_CPU(int, cpu_state) = { 0 };
+
+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;
+}
+#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