pci_irq.c

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/*
 *  pci_irq.c - ACPI PCI Interrupt Routing ($Revision: 11 $)
 *
 *  Copyright (C) 2001, 2002 Andy Grover <[email protected]>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
 *  Copyright (C) 2002       Dominik Brodowski <[email protected]>
 *  (c) Copyright 2008 Hewlett-Packard Development Company, L.P.
 *  Bjorn Helgaas <[email protected]>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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/dmi.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/pm.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/slab.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>

#define PREFIX "ACPI: "

#define _COMPONENT      ACPI_PCI_COMPONENT
ACPI_MODULE_NAME("pci_irq");

struct acpi_prt_entry {
    struct list_head    list;
    struct acpi_pci_id  id;
    u8          pin;
    acpi_handle     link;
    u32         index;      /* GSI, or link _CRS index */
};

static LIST_HEAD(acpi_prt_list);
static DEFINE_SPINLOCK(acpi_prt_lock);

static inline char pin_name(int pin)
{
    return 'A' + pin - 1;
}

/* --------------------------------------------------------------------------
                         PCI IRQ Routing Table (PRT) Support
   -------------------------------------------------------------------------- */

static struct acpi_prt_entry *acpi_pci_irq_find_prt_entry(struct pci_dev *dev,
                              int pin)
{
    struct acpi_prt_entry *entry;
    int segment = pci_domain_nr(dev->bus);
    int bus = dev->bus->number;
    int device = PCI_SLOT(dev->devfn);

    spin_lock(&acpi_prt_lock);
    list_for_each_entry(entry, &acpi_prt_list, list) {
        if ((segment == entry->id.segment)
            && (bus == entry->id.bus)
            && (device == entry->id.device)
            && (pin == entry->pin)) {
            spin_unlock(&acpi_prt_lock);
            return entry;
        }
    }
    spin_unlock(&acpi_prt_lock);
    return NULL;
}

/* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
static const struct dmi_system_id medion_md9580[] = {
    {
        .ident = "Medion MD9580-F laptop",
        .matches = {
            DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"),
            DMI_MATCH(DMI_PRODUCT_NAME, "A555"),
        },
    },
    { }
};

/* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */
static const struct dmi_system_id dell_optiplex[] = {
    {
        .ident = "Dell Optiplex GX1",
        .matches = {
            DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
            DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"),
        },
    },
    { }
};

/* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */
static const struct dmi_system_id hp_t5710[] = {
    {
        .ident = "HP t5710",
        .matches = {
            DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
            DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"),
            DMI_MATCH(DMI_BOARD_NAME, "098Ch"),
        },
    },
    { }
};

struct prt_quirk {
    const struct dmi_system_id *system;
    unsigned int        segment;
    unsigned int        bus;
    unsigned int        device;
    unsigned char       pin;
    const char      *source;    /* according to BIOS */
    const char      *actual_source;
};

#define PCI_INTX_PIN(c)     (c - 'A' + 1)

/*
 * These systems have incorrect _PRT entries.  The BIOS claims the PCI
 * interrupt at the listed segment/bus/device/pin is connected to the first
 * link device, but it is actually connected to the second.
 */
static const struct prt_quirk prt_quirks[] = {
    { medion_md9580, 0, 0, 9, PCI_INTX_PIN('A'),
        "\\_SB_.PCI0.ISA_.LNKA",
        "\\_SB_.PCI0.ISA_.LNKB"},
    { dell_optiplex, 0, 0, 0xd, PCI_INTX_PIN('A'),
        "\\_SB_.LNKB",
        "\\_SB_.LNKA"},
    { hp_t5710, 0, 0, 1, PCI_INTX_PIN('A'),
        "\\_SB_.PCI0.LNK1",
        "\\_SB_.PCI0.LNK3"},
};

static void do_prt_fixups(struct acpi_prt_entry *entry,
              struct acpi_pci_routing_table *prt)
{
    int i;
    const struct prt_quirk *quirk;

    for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) {
        quirk = &prt_quirks[i];

        /* All current quirks involve link devices, not GSIs */
        if (!prt->source)
            continue;

        if (dmi_check_system(quirk->system) &&
            entry->id.segment == quirk->segment &&
            entry->id.bus == quirk->bus &&
            entry->id.device == quirk->device &&
            entry->pin == quirk->pin &&
            !strcmp(prt->source, quirk->source) &&
            strlen(prt->source) >= strlen(quirk->actual_source)) {
            printk(KERN_WARNING PREFIX "firmware reports "
                "%04x:%02x:%02x PCI INT %c connected to %s; "
                "changing to %s\n",
                entry->id.segment, entry->id.bus,
                entry->id.device, pin_name(entry->pin),
                prt->source, quirk->actual_source);
            strcpy(prt->source, quirk->actual_source);
        }
    }
}

static int acpi_pci_irq_add_entry(acpi_handle handle, struct pci_bus *bus,
                  struct acpi_pci_routing_table *prt)
{
    struct acpi_prt_entry *entry;

    entry = kzalloc(sizeof(struct acpi_prt_entry), GFP_KERNEL);
    if (!entry)
        return -ENOMEM;

    /*
     * Note that the _PRT uses 0=INTA, 1=INTB, etc, while PCI uses
     * 1=INTA, 2=INTB.  We use the PCI encoding throughout, so convert
     * it here.
     */
    entry->id.segment = pci_domain_nr(bus);
    entry->id.bus = bus->number;
    entry->id.device = (prt->address >> 16) & 0xFFFF;
    entry->pin = prt->pin + 1;

    do_prt_fixups(entry, prt);

    entry->index = prt->source_index;

    /*
     * 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);

    /*
     * 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.
     */

    ACPI_DEBUG_PRINT_RAW((ACPI_DB_INFO,
                  "      %04x:%02x:%02x[%c] -> %s[%d]\n",
                  entry->id.segment, entry->id.bus,
                  entry->id.device, pin_name(entry->pin),
                  prt->source, entry->index));

    spin_lock(&acpi_prt_lock);
    list_add_tail(&entry->list, &acpi_prt_list);
    spin_unlock(&acpi_prt_lock);

    return 0;
}

int acpi_pci_irq_add_prt(acpi_handle handle, struct pci_bus *bus)
{
    acpi_status status;
    struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
    struct acpi_pci_routing_table *entry;

    /* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
    status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
    if (ACPI_FAILURE(status))
        return -ENODEV;

    printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
           (char *) buffer.pointer);

    kfree(buffer.pointer);

    buffer.length = ACPI_ALLOCATE_BUFFER;
    buffer.pointer = NULL;

    status = acpi_get_irq_routing_table(handle, &buffer);
    if (ACPI_FAILURE(status)) {
        ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]",
                acpi_format_exception(status)));
        kfree(buffer.pointer);
        return -ENODEV;
    }

    entry = buffer.pointer;
    while (entry && (entry->length > 0)) {
        acpi_pci_irq_add_entry(handle, bus, entry);
        entry = (struct acpi_pci_routing_table *)
            ((unsigned long)entry + entry->length);
    }

    kfree(buffer.pointer);
    return 0;
}

void acpi_pci_irq_del_prt(struct pci_bus *bus)
{
    struct acpi_prt_entry *entry, *tmp;

    printk(KERN_DEBUG
           "ACPI: Delete PCI Interrupt Routing Table for %04x:%02x\n",
           pci_domain_nr(bus), bus->number);
    spin_lock(&acpi_prt_lock);
    list_for_each_entry_safe(entry, tmp, &acpi_prt_list, list) {
        if (pci_domain_nr(bus) == entry->id.segment
            && bus->number == entry->id.bus) {
            list_del(&entry->list);
            kfree(entry);
        }
    }
    spin_unlock(&acpi_prt_lock);
}

/* --------------------------------------------------------------------------
                          PCI Interrupt Routing Support
   -------------------------------------------------------------------------- */
#ifdef CONFIG_X86_IO_APIC
extern int noioapicquirk;
extern int noioapicreroute;

static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
{
    struct pci_bus *bus_it;

    for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
        if (!bus_it->self)
            return 0;
        if (bus_it->self->irq_reroute_variant)
            return bus_it->self->irq_reroute_variant;
    }
    return 0;
}

/*
 * Some chipsets (e.g. Intel 6700PXH) generate a legacy INTx when the IRQ
 * entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel does
 * during interrupt handling). When this INTx generation cannot be disabled,
 * we reroute these interrupts to their legacy equivalent to get rid of
 * spurious interrupts.
 */
static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
                       struct acpi_prt_entry *entry)
{
    if (noioapicquirk || noioapicreroute) {
        return 0;
    } else {
        switch (bridge_has_boot_interrupt_variant(dev->bus)) {
        case 0:
            /* no rerouting necessary */
            return 0;
        case INTEL_IRQ_REROUTE_VARIANT:
            /*
             * Remap according to INTx routing table in 6700PXH
             * specs, intel order number 302628-002, section
             * 2.15.2. Other chipsets (80332, ...) have the same
             * mapping and are handled here as well.
             */
            dev_info(&dev->dev, "PCI IRQ %d -> rerouted to legacy "
                 "IRQ %d\n", entry->index,
                 (entry->index % 4) + 16);
            entry->index = (entry->index % 4) + 16;
            return 1;
        default:
            dev_warn(&dev->dev, "Cannot reroute IRQ %d to legacy "
                 "IRQ: unknown mapping\n", entry->index);
            return -1;
        }
    }
}
#endif /* CONFIG_X86_IO_APIC */

static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
{
    struct acpi_prt_entry *entry;
    struct pci_dev *bridge;
    u8 bridge_pin, orig_pin = pin;

    entry = acpi_pci_irq_find_prt_entry(dev, pin);
    if (entry) {
#ifdef CONFIG_X86_IO_APIC
        acpi_reroute_boot_interrupt(dev, entry);
#endif /* CONFIG_X86_IO_APIC */
        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %s[%c] _PRT entry\n",
                  pci_name(dev), pin_name(pin)));
        return entry;
    }

    /* 
     * 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).
     */
    bridge = dev->bus->self;
    while (bridge) {
        pin = pci_swizzle_interrupt_pin(dev, pin);

        if ((bridge->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
            /* PC card has the same IRQ as its cardbridge */
            bridge_pin = bridge->pin;
            if (!bridge_pin) {
                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                          "No interrupt pin configured for device %s\n",
                          pci_name(bridge)));
                return NULL;
            }
            pin = bridge_pin;
        }

        entry = acpi_pci_irq_find_prt_entry(bridge, pin);
        if (entry) {
            ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                     "Derived GSI for %s INT %c from %s\n",
                     pci_name(dev), pin_name(orig_pin),
                     pci_name(bridge)));
            return entry;
        }

        dev = bridge;
        bridge = dev->bus->self;
    }

    dev_warn(&dev->dev, "can't derive routing for PCI INT %c\n",
         pin_name(orig_pin));
    return NULL;
}

int acpi_pci_irq_enable(struct pci_dev *dev)
{
    struct acpi_prt_entry *entry;
    int gsi;
    u8 pin;
    int triggering = ACPI_LEVEL_SENSITIVE;
    int polarity = ACPI_ACTIVE_LOW;
    char *link = NULL;
    char link_desc[16];
    int rc;

    pin = dev->pin;
    if (!pin) {
        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                  "No interrupt pin configured for device %s\n",
                  pci_name(dev)));
        return 0;
    }

    entry = acpi_pci_irq_lookup(dev, pin);
    if (!entry) {
        /*
         * IDE legacy mode controller IRQs are magic. Why do compat
         * extensions always make such a nasty mess.
         */
        if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
                (dev->class & 0x05) == 0)
            return 0;
    }

    if (entry) {
        if (entry->link)
            gsi = acpi_pci_link_allocate_irq(entry->link,
                             entry->index,
                             &triggering, &polarity,
                             &link);
        else
            gsi = entry->index;
    } else
        gsi = -1;

    /*
     * No IRQ known to the ACPI subsystem - maybe the BIOS / 
     * driver reported one, then use it. Exit in any case.
     */
    if (gsi < 0) {
        u32 dev_gsi;
        dev_warn(&dev->dev, "PCI INT %c: no GSI", pin_name(pin));
        /* Interrupt Line values above 0xF are forbidden */
        if (dev->irq > 0 && (dev->irq <= 0xF) &&
            (acpi_isa_irq_to_gsi(dev->irq, &dev_gsi) == 0)) {
            printk(" - using ISA IRQ %d\n", dev->irq);
            acpi_register_gsi(&dev->dev, dev_gsi,
                      ACPI_LEVEL_SENSITIVE,
                      ACPI_ACTIVE_LOW);
            return 0;
        } else {
            printk("\n");
            return 0;
        }
    }

    rc = acpi_register_gsi(&dev->dev, gsi, triggering, polarity);
    if (rc < 0) {
        dev_warn(&dev->dev, "PCI INT %c: failed to register GSI\n",
             pin_name(pin));
        return rc;
    }
    dev->irq = rc;

    if (link)
        snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
    else
        link_desc[0] = '\0';

    dev_dbg(&dev->dev, "PCI INT %c%s -> GSI %u (%s, %s) -> IRQ %d\n",
        pin_name(pin), link_desc, gsi,
        (triggering == ACPI_LEVEL_SENSITIVE) ? "level" : "edge",
        (polarity == ACPI_ACTIVE_LOW) ? "low" : "high", dev->irq);

    return 0;
}

/* FIXME: implement x86/x86_64 version */
void __attribute__ ((weak)) acpi_unregister_gsi(u32 i)
{
}

void acpi_pci_irq_disable(struct pci_dev *dev)
{
    struct acpi_prt_entry *entry;
    int gsi;
    u8 pin;

    pin = dev->pin;
    if (!pin)
        return;

    entry = acpi_pci_irq_lookup(dev, pin);
    if (!entry)
        return;

    if (entry->link)
        gsi = acpi_pci_link_free_irq(entry->link);
    else
        gsi = entry->index;

    /*
     * TBD: It might be worth clearing dev->irq by magic constant
     * (e.g. PCI_UNDEFINED_IRQ).
     */

    dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin));
    acpi_unregister_gsi(gsi);
}