include

/*
 * 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/vdso.h>
#include <asm/debug.h>

#ifdef DEBUG
#include <asm/udbg.h>
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif

#ifdef CONFIG_HOTPLUG_CPU
/* State of each CPU during hotplug phases */
static DEFINE_PER_CPU(int, cpu_state) = { 0 };
#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 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
	 */
	generic_set_cpu_up(nr);
	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 | IRQF_NO_SUSPEND,
			  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;

	/*
	 * Order previous accesses before accesses in the IPI handler.
	 */
	smp_mb();
	message[msg] = 1;
	/*
	 * cause_ipi functions are required to include a full barrier
	 * before doing whatever causes the IPI.
	 */
	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(&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)
{
	</
Mode	Name	Size
d---------	acpi	1209	log stats plain
d---------	asm-generic	4628	log stats plain
d---------	clocksource	285	log stats plain
d---------	crypto	2072	log stats plain
d---------	drm	3899	log stats plain
d---------	dt-bindings	1135	log stats plain
d---------	keys	611	log stats plain
d---------	kunit	109	log stats plain
d---------	kvm	236	log stats plain
d---------	linux	49396	log stats plain
d---------	math-emu	318	log stats plain
d---------	media	2663	log stats plain
d---------	misc	218	log stats plain
d---------	net	7686	log stats plain
d---------	pcmcia	212	log stats plain
d---------	ras	39	log stats plain
d---------	rdma	1470	log stats plain
d---------	scsi	1533	log stats plain
d---------	soc	449	log stats plain
d---------	sound	5927	log stats plain
d---------	target	175	log stats plain
d---------	trace	227	log stats plain
d---------	uapi	351	log stats plain
d---------	vdso	113	log stats plain
d---------	video	1850	log stats plain
d---------	xen	685	log stats plain