/*
 * Copyright (c) 2006 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/machintr.h>
#include <sys/errno.h>
#include <sys/mman.h>
#include <sys/globaldata.h>
#include <sys/interrupt.h>
#include <stdio.h>
#include <signal.h>
#include <machine/globaldata.h>
#include <machine/md_var.h>
#include <sys/thread2.h>

#include <unistd.h>

/*
 * Interrupt Subsystem ABI
 */

static void dummy_intr_disable(int);
static void dummy_intr_enable(int);
static void dummy_intr_setup(int, int);
static void dummy_intr_teardown(int);
static int dummy_legacy_intr_cpuid(int);
static void dummy_finalize(void);
static void dummy_intrcleanup(void);
static void dummy_stabilize(void);

struct machintr_abi MachIntrABI = {
        MACHINTR_GENERIC,
        .intr_disable = dummy_intr_disable,
        .intr_enable =  dummy_intr_enable,
        .intr_setup =   dummy_intr_setup,
        .intr_teardown = dummy_intr_teardown,
        .legacy_intr_cpuid = dummy_legacy_intr_cpuid,

        .finalize =     dummy_finalize,
        .cleanup =      dummy_intrcleanup,
        .stabilize =    dummy_stabilize
};

static void
dummy_intr_disable(int intr)
{
}

static void
dummy_intr_enable(int intr)
{
}

static void
dummy_intr_setup(int intr, int flags)
{
}

static void
dummy_intr_teardown(int intr)
{
}

static void
dummy_finalize(void)
{
}

static void
dummy_intrcleanup(void)
{
}

static void
dummy_stabilize(void)
{
}

static int
dummy_legacy_intr_cpuid(int irq __unused)
{
        return 0;
}

/*
 * Process pending interrupts
 */
void
splz(void)
{
        struct mdglobaldata *gd = mdcpu;
        thread_t td = gd->mi.gd_curthread;
        int irq;

        while (gd->mi.gd_reqflags & (RQF_IPIQ|RQF_INTPEND|
                                     RQF_TIMER|RQF_KQUEUE)) {
                crit_enter_quick(td);
                if (gd->mi.gd_reqflags & RQF_IPIQ) {
                        atomic_clear_int(&gd->mi.gd_reqflags, RQF_IPIQ);
                        atomic_swap_int(&gd->mi.gd_npoll, 0);
                        lwkt_process_ipiq();
                }
                if (gd->mi.gd_reqflags & RQF_INTPEND) {
                        atomic_clear_int(&gd->mi.gd_reqflags, RQF_INTPEND);
                        while ((irq = ffs(gd->gd_spending)) != 0) {
                                --irq;
                                atomic_clear_int(&gd->gd_spending, 1 << irq);
                                irq += FIRST_SOFTINT;
                                sched_ithd_soft(irq);
                        }
                        while ((irq = ffs(gd->gd_fpending)) != 0) {
                                --irq;
                                atomic_clear_int(&gd->gd_fpending, 1 << irq);
                                sched_ithd_hard_virtual(irq);
                        }
                }
                if (gd->mi.gd_reqflags & RQF_TIMER) {
                        atomic_clear_int(&gd->mi.gd_reqflags, RQF_TIMER);
                        vktimer_intr(NULL);
                }
                if (gd->mi.gd_reqflags & RQF_KQUEUE) {
                        atomic_clear_int(&gd->mi.gd_reqflags, RQF_KQUEUE);
                        kqueue_intr(NULL);
                }
                crit_exit_noyield(td);
        }
}

/*
 * Allows an unprotected signal handler or mailbox to signal an interrupt
 *
 * For sched_ithd_hard_virtual() to properly preempt via lwkt_schedule() we
 * cannot enter a critical section here.  We use td_nest_count instead.
 */
void
signalintr(int intr)
{
        struct mdglobaldata *gd = mdcpu;
        thread_t td = gd->mi.gd_curthread;

        if (td->td_critcount || td->td_nest_count) {
                atomic_set_int_nonlocked(&gd->gd_fpending, 1 << intr);
                atomic_set_int(&gd->mi.gd_reqflags, RQF_INTPEND);
                umtx_wakeup(&gd->mi.gd_reqflags, 0);
        } else {
                ++td->td_nest_count;
                cpu_ccfence();
                atomic_clear_int(&gd->gd_fpending, 1 << intr);
                sched_ithd_hard_virtual(intr);
                cpu_ccfence();
                --td->td_nest_count;
        }
}

/*
 * Must block any signal normally handled as maskable interrupt.
 */
void
cpu_disable_intr(void)
{
        sigblock(sigmask(SIGALRM)|sigmask(SIGIO)|sigmask(SIGUSR1)|
                 sigmask(SIGURG));
}

void
cpu_enable_intr(void)
{
        sigsetmask(0);
}

void
cpu_mask_all_signals(void)
{
        sigblock(sigmask(SIGALRM)|sigmask(SIGIO)|sigmask(SIGQUIT)|
                 sigmask(SIGUSR1)|sigmask(SIGTERM)|sigmask(SIGWINCH)|
                 sigmask(SIGUSR2)|sigmask(SIGURG));
}

void
cpu_unmask_all_signals(void)
{
        sigsetmask(0);
}

int
cpu_interrupt_running(struct thread *td)
{
        struct mdglobaldata *gd = mdcpu;

        if ((td->td_flags & TDF_INTTHREAD) ||
            gd->gd_fpending ||
            gd->gd_spending) {
                return 1;
        }
        return 0;
}