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/*

 *  pci_irq.c - ACPI PCI Interrupt Routing ($Revision: 1.1.1.1 $)

 *

 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>

 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>

 *  Copyright (C) 2002       Dominik Brodowski <devel@brodo.de>

 *

 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 *

 *  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.

 *

 *  This program is distributed in the hope that it will be useful, but

 *  WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 *  General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License along

 *  with this program; if not, write to the Free Software Foundation, Inc.,

 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

 *

 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 */

#include <linux/config.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/types.h>

#include <linux/proc_fs.h>

#include <linux/spinlock.h>

#include <linux/pm.h>

#include <linux/pci.h>

#include <linux/acpi.h>

#ifdef CONFIG_X86_IO_APIC

#include <asm/mpspec.h>

#endif

#ifdef CONFIG_IOSAPIC

# include <asm/iosapic.h>

#endif

#include <acpi/acpi_bus.h>

#include <acpi/acpi_drivers.h>

#define _COMPONENT              ACPI_PCI_COMPONENT

ACPI_MODULE_NAME                ("pci_irq")

#define PREFIX                  "PCI: "

struct acpi_prt_list            acpi_prt;

#ifdef CONFIG_X86

extern void eisa_set_level_irq(unsigned int irq);

#endif

/* --------------------------------------------------------------------------

                         PCI IRQ Routing Table (PRT) Support

   -------------------------------------------------------------------------- */

static struct acpi_prt_entry *

acpi_pci_irq_find_prt_entry (

        int                     segment,

        int                     bus,

        int                     device,

        int                     pin)

{

        struct list_head        *node = NULL;

        struct acpi_prt_entry   *entry = NULL;

        ACPI_FUNCTION_TRACE("acpi_pci_irq_find_prt_entry");

        if (!acpi_prt.count)

                return_PTR(NULL);

        /*

         * Parse through all PRT entries looking for a match on the specified

         * PCI device's segment, bus, device, and pin (don't care about func).

         *

         * TBD: Acquire/release lock

         */

        list_for_each(node, &acpi_prt.entries) {

                entry = list_entry(node, struct acpi_prt_entry, node);

                if ((segment == entry->id.segment)

                        && (bus == entry->id.bus)

                        && (device == entry->id.device)

                        && (pin == entry->pin)) {

                        return_PTR(entry);

                }

        }

        return_PTR(NULL);

}

static int

acpi_pci_irq_add_entry (

        acpi_handle                     handle,

        int                             segment,

        int                             bus,

        struct acpi_pci_routing_table   *prt)

{

        struct acpi_prt_entry   *entry = NULL;

        ACPI_FUNCTION_TRACE("acpi_pci_irq_add_entry");

        if (!prt)

                return_VALUE(-EINVAL);

        entry = kmalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);

        if (!entry)

                return_VALUE(-ENOMEM);

        memset(entry, 0, sizeof(struct acpi_prt_entry));

        entry->id.segment = segment;

        entry->id.bus = bus;

        entry->id.device = (prt->address >> 16) & 0xFFFF;

        entry->id.function = prt->address & 0xFFFF;

        entry->pin = prt->pin;

        /*

         * Type 1: Dynamic

         * ---------------

         * The 'source' field specifies the PCI interrupt link device used to

         * configure the IRQ assigned to this slot|dev|pin.  The 'source_index'

         * indicates which resource descriptor in the resource template (of

         * the link device) this interrupt is allocated from.

         *

         * NOTE: Don't query the Link Device for IRQ information at this time

         *       because Link Device enumeration may not have occurred yet

         *       (e.g. exists somewhere 'below' this _PRT entry in the ACPI

         *       namespace).

         */

        if (prt->source[0]) {

                acpi_get_handle(handle, prt->source, &entry->link.handle);

                entry->link.index = prt->source_index;

        }

        /*

         * Type 2: Static

         * --------------

         * The 'source' field is NULL, and the 'source_index' field specifies

         * the IRQ value, which is hardwired to specific interrupt inputs on

         * the interrupt controller.

         */

        else

                entry->link.index = prt->source_index;

        ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,

                "      %02X:%02X:%02X[%c] -> %s[%d]\n",

                entry->id.segment, entry->id.bus, entry->id.device,

                ('A' + entry->pin), prt->source, entry->link.index));

        /* TBD: Acquire/release lock */

        list_add_tail(&entry->node, &acpi_prt.entries);

        acpi_prt.count++;

        return_VALUE(0);

}

int

acpi_pci_irq_add_prt (

        acpi_handle             handle,

        int                     segment,

        int                     bus)

{

        acpi_status                     status = AE_OK;

        char                            pathname[ACPI_PATHNAME_MAX] = {0};

        struct acpi_buffer              buffer = {0, NULL};

        struct acpi_pci_routing_table   *prt = NULL;

        struct acpi_pci_routing_table   *entry = NULL;

        static int                      first_time = 1;

        ACPI_FUNCTION_TRACE("acpi_pci_irq_add_prt");

        if (first_time) {

                acpi_prt.count = 0;

                INIT_LIST_HEAD(&acpi_prt.entries);

                first_time = 0;

        }

        /*

         * NOTE: We're given a 'handle' to the _PRT object's parent device

         *       (either a PCI root bridge or PCI-PCI bridge).

         */

        buffer.length = sizeof(pathname);

        buffer.pointer = pathname;

        acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);

        printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",

                pathname);

        /*

         * Evaluate this _PRT and add its entries to our global list (acpi_prt).

         */

        buffer.length = 0;

        buffer.pointer = NULL;

        status = acpi_get_irq_routing_table(handle, &buffer);

        if (status != AE_BUFFER_OVERFLOW) {

                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n",

                        acpi_format_exception(status)));

                return_VALUE(-ENODEV);

        }

        prt = kmalloc(buffer.length, GFP_KERNEL);

        if (!prt)

                return_VALUE(-ENOMEM);

        memset(prt, 0, buffer.length);

        buffer.pointer = prt;

        status = acpi_get_irq_routing_table(handle, &buffer);

        if (ACPI_FAILURE(status)) {

                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRT [%s]\n",

                        acpi_format_exception(status)));

                kfree(buffer.pointer);

                return_VALUE(-ENODEV);

        }

        entry = prt;

        while (entry && (entry->length > 0)) {

                acpi_pci_irq_add_entry(handle, segment, bus, entry);

                entry = (struct acpi_pci_routing_table *)

                        ((unsigned long) entry + entry->length);

        }

        kfree(prt);

        return_VALUE(0);

}

/* --------------------------------------------------------------------------

                          PCI Interrupt Routing Support

   -------------------------------------------------------------------------- */

int

acpi_pci_irq_lookup (

        int                     segment,

        int                     bus,

        int                     device,

        int                     pin)

{

        struct acpi_prt_entry   *entry = NULL;

        ACPI_FUNCTION_TRACE("acpi_pci_irq_lookup");

        ACPI_DEBUG_PRINT((ACPI_DB_INFO,

                "Searching for PRT entry for %02x:%02x:%02x[%c]\n",

                segment, bus, device, ('A' + pin)));

        entry = acpi_pci_irq_find_prt_entry(segment, bus, device, pin);

        if (!entry) {

                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PRT entry not found\n"));

                return_VALUE(0);

        }

        if (!entry->irq && entry->link.handle) {

                entry->irq = acpi_pci_link_get_irq(entry->link.handle, entry->link.index, NULL, NULL);

                if (!entry->irq) {

                        ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ link routing entry\n"));

                        return_VALUE(0);

                }

        }

        else if (!entry->irq) {

                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid static routing entry (IRQ 0)\n"));

                return_VALUE(0);

        }

        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found IRQ %d\n", entry->irq));

        return_VALUE(entry->irq);

}

static int

acpi_pci_irq_derive (

        struct pci_dev          *dev,

        int                     pin)

{

        struct pci_dev          *bridge = dev;

        int                     irq = 0;

        u8                      bridge_pin = 0;

        ACPI_FUNCTION_TRACE("acpi_pci_irq_derive");

        if (!dev)

                return_VALUE(-EINVAL);

        /*

         * Attempt to derive an IRQ for this device from a parent bridge's

         * PCI interrupt routing entry (eg. yenta bridge and add-in card bridge)

         */

        while (!irq && bridge->bus->self) {

                pin = (pin + PCI_SLOT(bridge->devfn)) % 4;

                bridge = bridge->bus->self;

                if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {

                        /* PC card has the same IRQ as its cardbridge */

                        pci_read_config_byte(bridge, PCI_INTERRUPT_PIN, &bridge_pin);

                        if (!bridge_pin) {

                                ACPI_DEBUG_PRINT((ACPI_DB_INFO,

                                        "No interrupt pin configured for device %s\n",

                                        pci_name(bridge)));

                                return_VALUE(0);

                        }

                        /* Pin is from 0 to 3 */

                        bridge_pin --;

                        pin = bridge_pin;

                }

                irq = acpi_pci_irq_lookup(0, bridge->bus->number,

                                PCI_SLOT(bridge->devfn), pin);

        }

        if (!irq) {

                ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Unable to derive IRQ for device %s\n", dev->slot_name));

                return_VALUE(0);

        }

        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Derive IRQ %d for device %s from %s\n",

                irq, pci_name(dev), pci_name(bridge)));

        return_VALUE(irq);

}

int

acpi_pci_irq_enable (

        struct pci_dev          *dev)

{

        int                     irq = 0;

        u8                      pin = 0;

        ACPI_FUNCTION_TRACE("acpi_pci_irq_enable");

        if (!dev)

                return_VALUE(-EINVAL);

        pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);

        if (!pin) {

                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No interrupt pin configured for device %s\n", dev->slot_name));

                return_VALUE(0);

        }

        pin--;

        if (!dev->bus) {

                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid (NULL) 'bus' field\n"));

                return_VALUE(-ENODEV);

        }

        /*

         * First we check the PCI IRQ routing table (PRT) for an IRQ.  PRT

         * values override any BIOS-assigned IRQs set during boot.

         */

        irq = acpi_pci_irq_lookup(0, dev->bus->number, PCI_SLOT(dev->devfn), pin);

        /*

         * If no PRT entry was found, we'll try to derive an IRQ from the

         * device's parent bridge.

         */

        if (!irq)

                irq = acpi_pci_irq_derive(dev, pin);

        /*

         * No IRQ known to the ACPI subsystem - maybe the BIOS /

         * driver reported one, then use it. Exit in any case.

         */

        if (!irq) {

                printk(KERN_WARNING PREFIX "No IRQ known for interrupt pin %c of device %s", ('A' + pin), dev->slot_name);

                /* Interrupt Line values above 0xF are forbidden */

                if (dev->irq && dev->irq >= 0xF) {

                        printk(" - using IRQ %d\n", dev->irq);

                        return_VALUE(dev->irq);

                }

                else {

                        printk("\n");

                        return_VALUE(0);

                }

        }

        dev->irq = irq;

        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device %s using IRQ %d\n", dev->slot_name, dev->irq));

        /*

         * Make sure all (legacy) PCI IRQs are set as level-triggered.

         */

#ifdef CONFIG_X86

        {

                static u16 irq_mask;

                if ((dev->irq < 16) &&  !((1 << dev->irq) & irq_mask)) {

                        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Setting IRQ %d as level-triggered\n", dev->irq));

                        irq_mask |= (1 << dev->irq);

                        eisa_set_level_irq(dev->irq);

                }

        }

#endif

#ifdef CONFIG_IOSAPIC

        if (acpi_irq_model == ACPI_IRQ_MODEL_IOSAPIC)

                iosapic_enable_intr(dev->irq);

#endif

        return_VALUE(dev->irq);

}

int __init

acpi_pci_irq_init (void)

{

        struct pci_dev          *dev = NULL;

        ACPI_FUNCTION_TRACE("acpi_pci_irq_init");

        if (!acpi_prt.count) {

                printk(KERN_WARNING PREFIX "ACPI tables contain no PCI IRQ "

                        "routing entries\n");

                return_VALUE(-ENODEV);

        }

        /* Make sure all link devices have a valid IRQ. */

        if (acpi_pci_link_check()) {

                return_VALUE(-ENODEV);

        }

#ifdef CONFIG_X86_IO_APIC

        /* Program IOAPICs using data from PRT entries. */

        if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)

                mp_parse_prt();

#endif

#ifdef CONFIG_IOSAPIC

        if (acpi_irq_model == ACPI_IRQ_MODEL_IOSAPIC)

                iosapic_parse_prt();

#endif

        pci_for_each_dev(dev)

                acpi_pci_irq_enable(dev);

        return_VALUE(0);

}