/*-
 * Copyright (c) 2000 Michael Smith
 * Copyright (c) 2000 BSDi
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 *
 * $FreeBSD: src/sys/dev/acpica/acpi_pcib.c,v 1.60.8.1 2009/04/15 03:14:26 kensmith Exp $
 */

#include "opt_acpi.h"
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/machintr.h>
#include <machine/smp.h>

#include "acpi.h"
#include <dev/acpica/acpivar.h>
#include <dev/acpica/acpi_pcibvar.h>

#include <bus/pci/pcivar.h>
#include <bus/pci/pcireg.h>
#include <bus/pci/pci_cfgreg.h>
#include "pcib_if.h"

/* Hooks for the ACPICA debugging infrastructure. */
#define _COMPONENT      ACPI_BUS
ACPI_MODULE_NAME("PCI")

ACPI_SERIAL_DECL(pcib, "ACPI PCI bus methods");

/*
 * For locking, we assume the caller is not concurrent since this is
 * triggered by newbus methods.
 */

struct prt_lookup_request {
    ACPI_PCI_ROUTING_TABLE *pr_entry;
    u_int       pr_pin;
    u_int       pr_slot;
};

typedef void prt_entry_handler(ACPI_PCI_ROUTING_TABLE *entry, void *arg);

static void     prt_attach_devices(ACPI_PCI_ROUTING_TABLE *entry, void *arg);
static void     prt_lookup_device(ACPI_PCI_ROUTING_TABLE *entry, void *arg);
static void     prt_walk_table(ACPI_BUFFER *prt, prt_entry_handler *handler,
                    void *arg);

static void
prt_walk_table(ACPI_BUFFER *prt, prt_entry_handler *handler, void *arg)
{
    ACPI_PCI_ROUTING_TABLE *entry;
    char *prtptr;

    /* First check to see if there is a table to walk. */
    if (prt == NULL || prt->Pointer == NULL)
        return;

    /* Walk the table executing the handler function for each entry. */
    prtptr = prt->Pointer;
    entry = (ACPI_PCI_ROUTING_TABLE *)prtptr;
    while (entry->Length != 0) {
        handler(entry, arg);
        prtptr += entry->Length;
        entry = (ACPI_PCI_ROUTING_TABLE *)prtptr;
    }
}

static void
prt_attach_devices(ACPI_PCI_ROUTING_TABLE *entry, void *arg)
{
    ACPI_HANDLE handle;
    device_t child, pcib;
    int error;

    /* We only care about entries that reference a link device. */
    if (entry->Source == NULL || entry->Source[0] == '\0')
        return;

    /*
     * In practice, we only see SourceIndex's of 0 out in the wild.
     * When indices != 0 have been found, they've been bugs in the ASL.
     */
    if (entry->SourceIndex != 0)
        return;

    /* Lookup the associated handle and device. */
    pcib = (device_t)arg;
    if (ACPI_FAILURE(AcpiGetHandle(ACPI_ROOT_OBJECT, entry->Source, &handle)))
        return;
    child = acpi_get_device(handle);
    if (child == NULL)
        return;

    /* If the device hasn't been probed yet, force it to do so. */
    error = device_probe_and_attach(child);
    if (error != 0) {
        device_printf(pcib, "failed to force attach of %s\n",
            acpi_name(handle));
        return;
    }

    /* Add a reference for a specific bus/device/pin tuple. */
    acpi_pci_link_add_reference(child, entry->SourceIndex, pcib,
        ACPI_ADR_PCI_SLOT(entry->Address), entry->Pin);
}

int
acpi_pcib_attach(device_t dev, ACPI_BUFFER *prt, int busno)
{
    device_t                    child;
    ACPI_STATUS                 status;

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    if (!acpi_DeviceIsPresent(dev)) {
        /* Caller should already have checked it */
        panic("%s device is not present", __func__);
    }

    ACPI_SERIAL_INIT(pcib);

    /*
     * Get the PCI interrupt routing table for this bus.  If we can't
     * get it, this is not an error but may reduce functionality.  There
     * are several valid bridges in the field that do not have a _PRT, so
     * only warn about missing tables if bootverbose is set.
     */
    prt->Length = ACPI_ALLOCATE_BUFFER;
    status = AcpiGetIrqRoutingTable(acpi_get_handle(dev), prt);
    if (ACPI_FAILURE(status) && (bootverbose || status != AE_NOT_FOUND))
        device_printf(dev,
            "could not get PCI interrupt routing table for %s - %s\n",
            acpi_name(acpi_get_handle(dev)), AcpiFormatException(status));

    /*
     * Attach the PCI bus proper.
     */
    if ((child = device_add_child(dev, "pci", busno)) == NULL) {
        device_printf(device_get_parent(dev), "couldn't attach pci bus\n");
        return_VALUE(ENXIO);
    }

    /*
     * Now go scan the bus.
     */
    prt_walk_table(prt, prt_attach_devices, dev);

    return_VALUE (bus_generic_attach(dev));
}

int
acpi_pcib_resume(device_t dev)
{

    return (bus_generic_resume(dev));
}

static void
prt_lookup_device(ACPI_PCI_ROUTING_TABLE *entry, void *arg)
{
    struct prt_lookup_request *pr;

    pr = (struct prt_lookup_request *)arg;
    if (pr->pr_entry != NULL)
        return;

    /*
     * Compare the slot number (high word of Address) and pin number
     * (note that ACPI uses 0 for INTA) to check for a match.
     *
     * Note that the low word of the Address field (function number)
     * is required by the specification to be 0xffff.  We don't risk
     * checking it here.
     */
    if (ACPI_ADR_PCI_SLOT(entry->Address) == pr->pr_slot &&
        entry->Pin == pr->pr_pin)
            pr->pr_entry = entry;
}

/*
 * Route an interrupt for a child of the bridge.
 */
int
acpi_pcib_route_interrupt(device_t pcib, device_t dev, int pin,
    ACPI_BUFFER *prtbuf)
{
    ACPI_PCI_ROUTING_TABLE *prt;
    struct prt_lookup_request pr;
    ACPI_HANDLE lnkdev;
    int interrupt;

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    interrupt = PCI_INVALID_IRQ;

    /* ACPI numbers pins 0-3, not 1-4 like the BIOS. */
    pin--;

    ACPI_SERIAL_BEGIN(pcib);

    /* Search for a matching entry in the routing table. */
    pr.pr_entry = NULL;
    pr.pr_pin = pin;
    pr.pr_slot = pci_get_slot(dev);
    prt_walk_table(prtbuf, prt_lookup_device, &pr);
    if (pr.pr_entry == NULL) {
        device_printf(pcib, "no PRT entry for %d.%d.INT%c\n", pci_get_bus(dev),
            pci_get_slot(dev), 'A' + pin);
        goto out;
    }
    prt = pr.pr_entry;

    if (bootverbose) {
        device_printf(pcib, "matched entry for %d.%d.INT%c",
            pci_get_bus(dev), pci_get_slot(dev), 'A' + pin);
        if (prt->Source != NULL && prt->Source[0] != '\0')
                kprintf(" (src %s:%u)", prt->Source, prt->SourceIndex);
        kprintf("\n");
    }

    /*
     * If source is empty/NULL, the source index is a GSI and it's hardwired
     * so we're done.
     *
     * XXX: If the source index is non-zero, ignore the source device and
     * assume that this is a hardwired entry.
     */
    if (prt->Source == NULL || prt->Source[0] == '\0' ||
        prt->SourceIndex != 0) {
        if (prt->SourceIndex) {
            interrupt = machintr_legacy_intr_find_bygsi(prt->SourceIndex,
                INTR_TRIGGER_LEVEL, INTR_POLARITY_LOW);
            if (interrupt < 0) {
                device_printf(pcib, "slot %d INT%c hardwired to "
                    "invalid GSI %d\n", pci_get_slot(dev), 'A' + pin,
                    prt->SourceIndex);
                interrupt = PCI_INVALID_IRQ;
                goto out;
            }
            if (bootverbose) {
                device_printf(pcib, "slot %d INT%c hardwired to "
                    "GSI %d, IRQ %d\n", pci_get_slot(dev), 'A' + pin,
                    prt->SourceIndex, interrupt);
            }

            BUS_CONFIG_INTR(device_get_parent(dev), dev, interrupt,
                INTR_TRIGGER_LEVEL, INTR_POLARITY_LOW);
        } else {
            device_printf(pcib, "invalid hardwired GSI 0\n");
        }
        goto out;
    }

    /*
     * We have to find the source device (PCI interrupt link device).
     */
    if (ACPI_FAILURE(AcpiGetHandle(ACPI_ROOT_OBJECT, prt->Source, &lnkdev))) {
        device_printf(pcib, "couldn't find PCI interrupt link device %s\n",
            prt->Source);
        goto out;
    }
    interrupt = acpi_pci_link_route_interrupt(acpi_get_device(lnkdev),
        prt->SourceIndex);

    if (bootverbose && PCI_INTERRUPT_VALID(interrupt)) {
        device_printf(pcib, "slot %d INT%c routed to irq %d via %s\n",
            pci_get_slot(dev), 'A' + pin, interrupt, acpi_name(lnkdev));
    }

out:
    ACPI_SERIAL_END(pcib);

    return_VALUE (interrupt);
}

int
acpi_pcib_probe(device_t dev)
{
    /*
     * Don't attach if we're not really there.
     *
     * XXX: This isn't entirely correct since we may be a PCI bus
     * on a hot-plug docking station, etc.
     */
    if (!acpi_DeviceIsPresent(dev))
        return ENXIO;

    if (pci_cfgregopen() == 0)
        return ENXIO;

    return 0;
}