// SPDX-License-Identifier: GPL-2.0
/*
 *      Low-Level PCI Support for PC -- Routing of Interrupts
 *
 *      (c) 1999--2000 Martin Mares <mj@ucw.cz>
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/dmi.h>
#include <linux/io.h>
#include <linux/smp.h>
#include <asm/io_apic.h>
#include <linux/irq.h>
#include <linux/acpi.h>
#include <asm/pci_x86.h>

#define PIRQ_SIGNATURE  (('$' << 0) + ('P' << 8) + ('I' << 16) + ('R' << 24))
#define PIRQ_VERSION 0x0100

static int broken_hp_bios_irq9;
static int acer_tm360_irqrouting;

static struct irq_routing_table *pirq_table;

static int pirq_enable_irq(struct pci_dev *dev);
static void pirq_disable_irq(struct pci_dev *dev);

/*
 * Never use: 0, 1, 2 (timer, keyboard, and cascade)
 * Avoid using: 13, 14 and 15 (FP error and IDE).
 * Penalize: 3, 4, 6, 7, 12 (known ISA uses: serial, floppy, parallel and mouse)
 */
unsigned int pcibios_irq_mask = 0xfff8;

static int pirq_penalty[16] = {
        1000000, 1000000, 1000000, 1000, 1000, 0, 1000, 1000,
        0, 0, 0, 0, 1000, 100000, 100000, 100000
};

struct irq_router {
        char *name;
        u16 vendor, device;
        int (*get)(struct pci_dev *router, struct pci_dev *dev, int pirq);
        int (*set)(struct pci_dev *router, struct pci_dev *dev, int pirq,
                int new);
};

struct irq_router_handler {
        u16 vendor;
        int (*probe)(struct irq_router *r, struct pci_dev *router, u16 device);
};

int (*pcibios_enable_irq)(struct pci_dev *dev) = pirq_enable_irq;
void (*pcibios_disable_irq)(struct pci_dev *dev) = pirq_disable_irq;

/*
 *  Check passed address for the PCI IRQ Routing Table signature
 *  and perform checksum verification.
 */

static inline struct irq_routing_table *pirq_check_routing_table(u8 *addr)
{
        struct irq_routing_table *rt;
        int i;
        u8 sum;

        rt = (struct irq_routing_table *) addr;
        if (rt->signature != PIRQ_SIGNATURE ||
            rt->version != PIRQ_VERSION ||
            rt->size % 16 ||
            rt->size < sizeof(struct irq_routing_table))
                return NULL;
        sum = 0;
        for (i = 0; i < rt->size; i++)
                sum += addr[i];
        if (!sum) {
                DBG(KERN_DEBUG "PCI: Interrupt Routing Table found at 0x%p\n",
                        rt);
                return rt;
        }
        return NULL;
}



/*
 *  Search 0xf0000 -- 0xfffff for the PCI IRQ Routing Table.
 */

static struct irq_routing_table * __init pirq_find_routing_table(void)
{
        u8 *addr;
        struct irq_routing_table *rt;

        if (pirq_table_addr) {
                rt = pirq_check_routing_table((u8 *) __va(pirq_table_addr));
                if (rt)
                        return rt;
                printk(KERN_WARNING "PCI: PIRQ table NOT found at pirqaddr\n");
        }
        for (addr = (u8 *) __va(0xf0000); addr < (u8 *) __va(0x100000); addr += 16) {
                rt = pirq_check_routing_table(addr);
                if (rt)
                        return rt;
        }
        return NULL;
}

/*
 *  If we have a IRQ routing table, use it to search for peer host
 *  bridges.  It's a gross hack, but since there are no other known
 *  ways how to get a list of buses, we have to go this way.
 */

static void __init pirq_peer_trick(void)
{
        struct irq_routing_table *rt = pirq_table;
        u8 busmap[256];
        int i;
        struct irq_info *e;

        memset(busmap, 0, sizeof(busmap));
        for (i = 0; i < (rt->size - sizeof(struct irq_routing_table)) / sizeof(struct irq_info); i++) {
                e = &rt->slots[i];
#ifdef DEBUG
                {
                        int j;
                        DBG(KERN_DEBUG "%02x:%02x slot=%02x", e->bus, e->devfn/8, e->slot);
                        for (j = 0; j < 4; j++)
                                DBG(" %d:%02x/%04x", j, e->irq[j].link, e->irq[j].bitmap);
                        DBG("\n");
                }
#endif
                busmap[e->bus] = 1;
        }
        for (i = 1; i < 256; i++) {
                if (!busmap[i] || pci_find_bus(0, i))
                        continue;
                pcibios_scan_root(i);
        }
        pcibios_last_bus = -1;
}

/*
 *  Code for querying and setting of IRQ routes on various interrupt routers.
 *  PIC Edge/Level Control Registers (ELCR) 0x4d0 & 0x4d1.
 */

void elcr_set_level_irq(unsigned int irq)
{
        unsigned char mask = 1 << (irq & 7);
        unsigned int port = 0x4d0 + (irq >> 3);
        unsigned char val;
        static u16 elcr_irq_mask;

        if (irq >= 16 || (1 << irq) & elcr_irq_mask)
                return;

        elcr_irq_mask |= (1 << irq);
        printk(KERN_DEBUG "PCI: setting IRQ %u as level-triggered\n", irq);
        val = inb(port);
        if (!(val & mask)) {
                DBG(KERN_DEBUG " -> edge");
                outb(val | mask, port);
        }
}

/*
 * Common IRQ routing practice: nibbles in config space,
 * offset by some magic constant.
 */
static unsigned int read_config_nybble(struct pci_dev *router, unsigned offset, unsigned nr)
{
        u8 x;
        unsigned reg = offset + (nr >> 1);

        pci_read_config_byte(router, reg, &x);
        return (nr & 1) ? (x >> 4) : (x & 0xf);
}

static void write_config_nybble(struct pci_dev *router, unsigned offset,
        unsigned nr, unsigned int val)
{
        u8 x;
        unsigned reg = offset + (nr >> 1);

        pci_read_config_byte(router, reg, &x);
        x = (nr & 1) ? ((x & 0x0f) | (val << 4)) : ((x & 0xf0) | val);
        pci_write_config_byte(router, reg, x);
}

/*
 * ALI pirq entries are damn ugly, and completely undocumented.
 * This has been figured out from pirq tables, and it's not a pretty
 * picture.
 */
static int pirq_ali_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
        static const unsigned char irqmap[16] = { 0, 9, 3, 10, 4, 5, 7, 6, 1, 11, 0, 12, 0, 14, 0, 15 };

        WARN_ON_ONCE(pirq > 16);
        return irqmap[read_config_nybble(router, 0x48, pirq-1)];
}

static int pirq_ali_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
        static const unsigned char irqmap[16] = { 0, 8, 0, 2, 4, 5, 7, 6, 0, 1, 3, 9, 11, 0, 13, 15 };
        unsigned int val = irqmap[irq];

        WARN_ON_ONCE(pirq > 16);
        if (val) {
                write_config_nybble(router, 0x48, pirq-1, val);
                return 1;
        }
        return 0;
}

/*
 * The Intel PIIX4 pirq rules are fairly simple: "pirq" is
 * just a pointer to the config space.
 */
static int pirq_piix_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
        u8 x;

        pci_read_config_byte(router, pirq, &x);
        return (x < 16) ? x : 0;
}

static int pirq_piix_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
        pci_write_config_byte(router, pirq, irq);
        return 1;
}

/*
 * The VIA pirq rules are nibble-based, like ALI,
 * but without the ugly irq number munging.
 * However, PIRQD is in the upper instead of lower 4 bits.
 */
static int pirq_via_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
        return read_config_nybble(router, 0x55, pirq == 4 ? 5 : pirq);
}

static int pirq_via_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
        write_config_nybble(router, 0x55, pirq == 4 ? 5 : pirq, irq);
        return 1;
}

/*
 * The VIA pirq rules are nibble-based, like ALI,
 * but without the ugly irq number munging.
 * However, for 82C586, nibble map is different .
 */
static int pirq_via586_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
        static const unsigned int pirqmap[5] = { 3, 2, 5, 1, 1 };

        WARN_ON_ONCE(pirq > 5);
        return read_config_nybble(router, 0x55, pirqmap[pirq-1]);
}

static int pirq_via586_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
        static const unsigned int pirqmap[5] = { 3, 2, 5, 1, 1 };

        WARN_ON_ONCE(pirq > 5);
        write_config_nybble(router, 0x55, pirqmap[pirq-1], irq);
        return 1;
}

/*
 * ITE 8330G pirq rules are nibble-based
 * FIXME: pirqmap may be { 1, 0, 3, 2 },
 *        2+3 are both mapped to irq 9 on my system
 */
static int pirq_ite_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
        static const unsigned char pirqmap[4] = { 1, 0, 2, 3 };

        WARN_ON_ONCE(pirq > 4);
        return read_config_nybble(router, 0x43, pirqmap[pirq-1]);
}

static int pirq_ite_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
        static const unsigned char pirqmap[4] = { 1, 0, 2, 3 };

        WARN_ON_ONCE(pirq > 4);
        write_config_nybble(router, 0x43, pirqmap[pirq-1], irq);
        return 1;
}

/*
 * OPTI: high four bits are nibble pointer..
 * I wonder what the low bits do?
 */
static int pirq_opti_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
        return read_config_nybble(router, 0xb8, pirq >> 4);
}

static int pirq_opti_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
        write_config_nybble(router, 0xb8, pirq >> 4, irq);
        return 1;
}

/*
 * Cyrix: nibble offset 0x5C
 * 0x5C bits 7:4 is INTB bits 3:0 is INTA
 * 0x5D bits 7:4 is INTD bits 3:0 is INTC
 */
static int pirq_cyrix_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
        return read_config_nybble(router, 0x5C, (pirq-1)^1);
}

static int pirq_cyrix_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
        write_config_nybble(router, 0x5C, (pirq-1)^1, irq);
        return 1;
}

/*
 *      PIRQ routing for SiS 85C503 router used in several SiS chipsets.
 *      We have to deal with the following issues here:
 *      - vendors have different ideas about the meaning of link values
 *      - some onboard devices (integrated in the chipset) have special
 *        links and are thus routed differently (i.e. not via PCI INTA-INTD)
 *      - different revision of the router have a different layout for
 *        the routing registers, particularly for the onchip devices
 *
 *      For all routing registers the common thing is we have one byte
 *      per routeable link which is defined as:
 *               bit 7      IRQ mapping enabled (0) or disabled (1)
 *               bits [6:4] reserved (sometimes used for onchip devices)
 *               bits [3:0] IRQ to map to
 *                   allowed: 3-7, 9-12, 14-15
 *                   reserved: 0, 1, 2, 8, 13
 *
 *      The config-space registers located at 0x41/0x42/0x43/0x44 are
 *      always used to route the normal PCI INT A/B/C/D respectively.
 *      Apparently there are systems implementing PCI routing table using
 *      link values 0x01-0x04 and others using 0x41-0x44 for PCI INTA..D.
 *      We try our best to handle both link mappings.
 *
 *      Currently (2003-05-21) it appears most SiS chipsets follow the
 *      definition of routing registers from the SiS-5595 southbridge.
 *      According to the SiS 5595 datasheets the revision id's of the
 *      router (ISA-bridge) should be 0x01 or 0xb0.
 *
 *      Furthermore we've also seen lspci dumps with revision 0x00 and 0xb1.
 *      Looks like these are used in a number of SiS 5xx/6xx/7xx chipsets.
 *      They seem to work with the current routing code. However there is
 *      some concern because of the two USB-OHCI HCs (original SiS 5595
 *      had only one). YMMV.
 *
 *      Onchip routing for router rev-id 0x01/0xb0 and probably 0x00/0xb1:
 *
 *      0x61:   IDEIRQ:
 *              bits [6:5] must be written 01
 *              bit 4 channel-select primary (0), secondary (1)
 *
 *      0x62:   USBIRQ:
 *              bit 6 OHCI function disabled (0), enabled (1)
 *
 *      0x6a:   ACPI/SCI IRQ: bits 4-6 reserved
 *
 *      0x7e:   Data Acq. Module IRQ - bits 4-6 reserved
 *
 *      We support USBIRQ (in addition to INTA-INTD) and keep the
 *      IDE, ACPI and DAQ routing untouched as set by the BIOS.
 *
 *      Currently the only reported exception is the new SiS 65x chipset
 *      which includes the SiS 69x southbridge. Here we have the 85C503
 *      router revision 0x04 and there are changes in the register layout
 *      mostly related to the different USB HCs with USB 2.0 support.
 *
 *      Onchip routing for router rev-id 0x04 (try-and-error observation)
 *
 *      0x60/0x61/0x62/0x63:    1xEHCI and 3xOHCI (companion) USB-HCs
 *                              bit 6-4 are probably unused, not like 5595
 */

#define PIRQ_SIS_IRQ_MASK       0x0f
#define PIRQ_SIS_IRQ_DISABLE    0x80
#define PIRQ_SIS_USB_ENABLE     0x40

static int pirq_sis_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
        u8 x;
        int reg;

        reg = pirq;
        if (reg >= 0x01 && reg <= 0x04)
                reg += 0x40;
        pci_read_config_byte(router, reg, &x);
        return (x & PIRQ_SIS_IRQ_DISABLE) ? 0 : (x & PIRQ_SIS_IRQ_MASK);
}

static int pirq_sis_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
        u8 x;
        int reg;

        reg = pirq;
        if (reg >= 0x01 && reg <= 0x04)
                reg += 0x40;
        pci_read_config_byte(router, reg, &x);
        x &= ~(PIRQ_SIS_IRQ_MASK | PIRQ_SIS_IRQ_DISABLE);
        x |= irq ? irq: PIRQ_SIS_IRQ_DISABLE;
        pci_write_config_byte(router, reg, x);
        return 1;
}


/*
 * VLSI: nibble offset 0x74 - educated guess due to routing table and
 *       config space of VLSI 82C534 PCI-bridge/router (1004:0102)
 *       Tested on HP OmniBook 800 covering PIRQ 1, 2, 4, 8 for onboard
 *       devices, PIRQ 3 for non-pci(!) soundchip and (untested) PIRQ 6
 *       for the busbridge to the docking station.
 */

static int pirq_vlsi_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
        WARN_ON_ONCE(pirq >= 9);
        if (pirq > 8) {
                dev_info(&dev->dev, "VLSI router PIRQ escape (%d)\n", pirq);
                return 0;
        }
        return read_config_nybble(router, 0x74, pirq-1);
}

static int pirq_vlsi_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
        WARN_ON_ONCE(pirq >= 9);
        if (pirq > 8) {
                dev_info(&dev->dev, "VLSI router PIRQ escape (%d)\n", pirq);
                return 0;
        }
        write_config_nybble(router, 0x74, pirq-1, irq);
        return 1;
}

/*
 * ServerWorks: PCI interrupts mapped to system IRQ lines through Index
 * and Redirect I/O registers (0x0c00 and 0x0c01).  The Index register
 * format is (PCIIRQ## | 0x10), e.g.: PCIIRQ10=0x1a.  The Redirect
 * register is a straight binary coding of desired PIC IRQ (low nibble).
 *
 * The 'link' value in the PIRQ table is already in the correct format
 * for the Index register.  There are some special index values:
 * 0x00 for ACPI (SCI), 0x01 for USB, 0x02 for IDE0, 0x04 for IDE1,
 * and 0x03 for SMBus.
 */
static int pirq_serverworks_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
        outb(pirq, 0xc00);
        return inb(0xc01) & 0xf;
}

static int pirq_serverworks_set(struct pci_dev *router, struct pci_dev *dev,
        int pirq, int irq)
{
        outb(pirq, 0xc00);
        outb(irq, 0xc01);
        return 1;
}

/* Support for AMD756 PCI IRQ Routing
 * Jhon H. Caicedo <jhcaiced@osso.org.co>
 * Jun/21/2001 0.2.0 Release, fixed to use "nybble" functions... (jhcaiced)
 * Jun/19/2001 Alpha Release 0.1.0 (jhcaiced)
 * The AMD756 pirq rules are nibble-based
 * offset 0x56 0-3 PIRQA  4-7  PIRQB
 * offset 0x57 0-3 PIRQC  4-7  PIRQD
 */
static int pirq_amd756_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
        u8 irq;
        irq = 0;
        if (pirq <= 4)
                irq = read_config_nybble(router, 0x56, pirq - 1);
        dev_info(&dev->dev,
                 "AMD756: dev [%04x:%04x], router PIRQ %d get IRQ %d\n",
                 dev->vendor, dev->device, pirq, irq);
        return irq;
}

static int pirq_amd756_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
        dev_info(&dev->dev,
                 "AMD756: dev [%04x:%04x], router PIRQ %d set IRQ %d\n",
                 dev->vendor, dev->device, pirq, irq);
        if (pirq <= 4)
                write_config_nybble(router, 0x56, pirq - 1, irq);
        return 1;
}

/*
 * PicoPower PT86C523
 */
static int pirq_pico_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
        outb(0x10 + ((pirq - 1) >> 1), 0x24);
        return ((pirq - 1) & 1) ? (inb(0x26) >> 4) : (inb(0x26) & 0xf);
}

static int pirq_pico_set(struct pci_dev *router, struct pci_dev *dev, int pirq,
                        int irq)
{
        unsigned int x;
        outb(0x10 + ((pirq - 1) >> 1), 0x24);
        x = inb(0x26);
        x = ((pirq - 1) & 1) ? ((x & 0x0f) | (irq << 4)) : ((x & 0xf0) | (irq));
        outb(x, 0x26);
        return 1;
}

#ifdef CONFIG_PCI_BIOS

static int pirq_bios_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
        struct pci_dev *bridge;
        int pin = pci_get_interrupt_pin(dev, &bridge);
        return pcibios_set_irq_routing(bridge, pin - 1, irq);
}

#endif

static __init int intel_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
{
        static struct pci_device_id __initdata pirq_440gx[] = {
                { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_0) },
                { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_2) },
                { },
        };

        /* 440GX has a proprietary PIRQ router -- don't use it */
        if (pci_dev_present(pirq_440gx))
                return 0;

        switch (device) {
        case PCI_DEVICE_ID_INTEL_82371FB_0:
        case PCI_DEVICE_ID_INTEL_82371SB_0:
        case PCI_DEVICE_ID_INTEL_82371AB_0:
        case PCI_DEVICE_ID_INTEL_82371MX:
        case PCI_DEVICE_ID_INTEL_82443MX_0:
        case PCI_DEVICE_ID_INTEL_82801AA_0:
        case PCI_DEVICE_ID_INTEL_82801AB_0:
        case PCI_DEVICE_ID_INTEL_82801BA_0:
        case PCI_DEVICE_ID_INTEL_82801BA_10:
        case PCI_DEVICE_ID_INTEL_82801CA_0:
        case PCI_DEVICE_ID_INTEL_82801CA_12:
        case PCI_DEVICE_ID_INTEL_82801DB_0:
        case PCI_DEVICE_ID_INTEL_82801E_0:
        case PCI_DEVICE_ID_INTEL_82801EB_0:
        case PCI_DEVICE_ID_INTEL_ESB_1:
        case PCI_DEVICE_ID_INTEL_ICH6_0:
        case PCI_DEVICE_ID_INTEL_ICH6_1:
        case PCI_DEVICE_ID_INTEL_ICH7_0:
        case PCI_DEVICE_ID_INTEL_ICH7_1:
        case PCI_DEVICE_ID_INTEL_ICH7_30:
        case PCI_DEVICE_ID_INTEL_ICH7_31:
        case PCI_DEVICE_ID_INTEL_TGP_LPC:
        case PCI_DEVICE_ID_INTEL_ESB2_0:
        case PCI_DEVICE_ID_INTEL_ICH8_0:
        case PCI_DEVICE_ID_INTEL_ICH8_1:
        case PCI_DEVICE_ID_INTEL_ICH8_2:
        case PCI_DEVICE_ID_INTEL_ICH8_3:
        case PCI_DEVICE_ID_INTEL_ICH8_4:
        case PCI_DEVICE_ID_INTEL_ICH9_0:
        case PCI_DEVICE_ID_INTEL_ICH9_1:
        case PCI_DEVICE_ID_INTEL_ICH9_2:
        case PCI_DEVICE_ID_INTEL_ICH9_3:
        case PCI_DEVICE_ID_INTEL_ICH9_4:
        case PCI_DEVICE_ID_INTEL_ICH9_5:
        case PCI_DEVICE_ID_INTEL_EP80579_0:
        case PCI_DEVICE_ID_INTEL_ICH10_0:
        case PCI_DEVICE_ID_INTEL_ICH10_1:
        case PCI_DEVICE_ID_INTEL_ICH10_2:
        case PCI_DEVICE_ID_INTEL_ICH10_3:
        case PCI_DEVICE_ID_INTEL_PATSBURG_LPC_0:
        case PCI_DEVICE_ID_INTEL_PATSBURG_LPC_1:
                r->name = "PIIX/ICH";
                r->get = pirq_piix_get;
                r->set = pirq_piix_set;
                return 1;
        }

        if ((device >= PCI_DEVICE_ID_INTEL_5_3400_SERIES_LPC_MIN && 
             device <= PCI_DEVICE_ID_INTEL_5_3400_SERIES_LPC_MAX) 
        ||  (device >= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MIN && 
             device <= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MAX)
        ||  (device >= PCI_DEVICE_ID_INTEL_DH89XXCC_LPC_MIN &&
             device <= PCI_DEVICE_ID_INTEL_DH89XXCC_LPC_MAX)
        ||  (device >= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MIN &&
             device <= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MAX)) {
                r->name = "PIIX/ICH";
                r->get = pirq_piix_get;
                r->set = pirq_piix_set;
                return 1;
        }

        return 0;
}

static __init int via_router_probe(struct irq_router *r,
                                struct pci_dev *router, u16 device)
{
        /* FIXME: We should move some of the quirk fixup stuff here */

        /*
         * workarounds for some buggy BIOSes
         */
        if (device == PCI_DEVICE_ID_VIA_82C586_0) {
                switch (router->device) {
                case PCI_DEVICE_ID_VIA_82C686:
                        /*
                         * Asus k7m bios wrongly reports 82C686A
                         * as 586-compatible
                         */
                        device = PCI_DEVICE_ID_VIA_82C686;
                        break;
                case PCI_DEVICE_ID_VIA_8235:
                        /**
                         * Asus a7v-x bios wrongly reports 8235
                         * as 586-compatible
                         */
                        device = PCI_DEVICE_ID_VIA_8235;
                        break;
                case PCI_DEVICE_ID_VIA_8237:
                        /**
                         * Asus a7v600 bios wrongly reports 8237
                         * as 586-compatible
                         */
                        device = PCI_DEVICE_ID_VIA_8237;
                        break;
                }
        }

        switch (device) {
        case PCI_DEVICE_ID_VIA_82C586_0:
                r->name = "VIA";
                r->get = pirq_via586_get;
                r->set = pirq_via586_set;
                return 1;
        case PCI_DEVICE_ID_VIA_82C596:
        case PCI_DEVICE_ID_VIA_82C686:
        case PCI_DEVICE_ID_VIA_8231:
        case PCI_DEVICE_ID_VIA_8233A:
        case PCI_DEVICE_ID_VIA_8235:
        case PCI_DEVICE_ID_VIA_8237:
                /* FIXME: add new ones for 8233/5 */
                r->name = "VIA";
                r->get = pirq_via_get;
                r->set = pirq_via_set;
                return 1;
        }
        return 0;
}

static __init int vlsi_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
{
        switch (device) {
        case PCI_DEVICE_ID_VLSI_82C534:
                r->name = "VLSI 82C534";
                r->get = pirq_vlsi_get;
                r->set = pirq_vlsi_set;
                return 1;
        }
        return 0;
}


static __init int serverworks_router_probe(struct irq_router *r,
                struct pci_dev *router, u16 device)
{
        switch (device) {
        case PCI_DEVICE_ID_SERVERWORKS_OSB4:
        case PCI_DEVICE_ID_SERVERWORKS_CSB5:
                r->name = "ServerWorks";
                r->get = pirq_serverworks_get;
                r->set = pirq_serverworks_set;
                return 1;
        }
        return 0;
}

static __init int sis_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
{
        if (device != PCI_DEVICE_ID_SI_503)
                return 0;

        r->name = "SIS";
        r->get = pirq_sis_get;
        r->set = pirq_sis_set;
        return 1;
}

static __init int cyrix_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
{
        switch (device) {
        case PCI_DEVICE_ID_CYRIX_5520:
                r->name = "NatSemi";
                r->get = pirq_cyrix_get;
                r->set = pirq_cyrix_set;
                return 1;
        }
        return 0;
}

static __init int opti_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
{
        switch (device) {
        case PCI_DEVICE_ID_OPTI_82C700:
                r->name = "OPTI";
                r->get = pirq_opti_get;
                r->set = pirq_opti_set;
                return 1;
        }
        return 0;
}

static __init int ite_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
{
        switch (device) {
        case PCI_DEVICE_ID_ITE_IT8330G_0:
                r->name = "ITE";
                r->get = pirq_ite_get;
                r->set = pirq_ite_set;
                return 1;
        }
        return 0;
}

static __init int ali_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
{
        switch (device) {
        case PCI_DEVICE_ID_AL_M1533:
        case PCI_DEVICE_ID_AL_M1563:
                r->name = "ALI";
                r->get = pirq_ali_get;
                r->set = pirq_ali_set;
                return 1;
        }
        return 0;
}

static __init int amd_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
{
        switch (device) {
        case PCI_DEVICE_ID_AMD_VIPER_740B:
                r->name = "AMD756";
                break;
        case PCI_DEVICE_ID_AMD_VIPER_7413:
                r->name = "AMD766";
                break;
        case PCI_DEVICE_ID_AMD_VIPER_7443:
                r->name = "AMD768";
                break;
        default:
                return 0;
        }
        r->get = pirq_amd756_get;
        r->set = pirq_amd756_set;
        return 1;
}

static __init int pico_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
{
        switch (device) {
        case PCI_DEVICE_ID_PICOPOWER_PT86C523:
                r->name = "PicoPower PT86C523";
                r->get = pirq_pico_get;
                r->set = pirq_pico_set;
                return 1;

        case PCI_DEVICE_ID_PICOPOWER_PT86C523BBP:
                r->name = "PicoPower PT86C523 rev. BB+";
                r->get = pirq_pico_get;
                r->set = pirq_pico_set;
                return 1;
        }
        return 0;
}

static __initdata struct irq_router_handler pirq_routers[] = {
        { PCI_VENDOR_ID_INTEL, intel_router_probe },
        { PCI_VENDOR_ID_AL, ali_router_probe },
        { PCI_VENDOR_ID_ITE, ite_router_probe },
        { PCI_VENDOR_ID_VIA, via_router_probe },
        { PCI_VENDOR_ID_OPTI, opti_router_probe },
        { PCI_VENDOR_ID_SI, sis_router_probe },
        { PCI_VENDOR_ID_CYRIX, cyrix_router_probe },
        { PCI_VENDOR_ID_VLSI, vlsi_router_probe },
        { PCI_VENDOR_ID_SERVERWORKS, serverworks_router_probe },
        { PCI_VENDOR_ID_AMD, amd_router_probe },
        { PCI_VENDOR_ID_PICOPOWER, pico_router_probe },
        /* Someone with docs needs to add the ATI Radeon IGP */
        { 0, NULL }
};
static struct irq_router pirq_router;
static struct pci_dev *pirq_router_dev;


/*
 *      FIXME: should we have an option to say "generic for
 *      chipset" ?
 */

static void __init pirq_find_router(struct irq_router *r)
{
        struct irq_routing_table *rt = pirq_table;
        struct irq_router_handler *h;

#ifdef CONFIG_PCI_BIOS
        if (!rt->signature) {
                printk(KERN_INFO "PCI: Using BIOS for IRQ routing\n");
                r->set = pirq_bios_set;
                r->name = "BIOS";
                return;
        }
#endif

        /* Default unless a driver reloads it */
        r->name = "default";
        r->get = NULL;
        r->set = NULL;

        DBG(KERN_DEBUG "PCI: Attempting to find IRQ router for [%04x:%04x]\n",
            rt->rtr_vendor, rt->rtr_device);

        pirq_router_dev = pci_get_bus_and_slot(rt->rtr_bus, rt->rtr_devfn);
        if (!pirq_router_dev) {
                DBG(KERN_DEBUG "PCI: Interrupt router not found at "
                        "%02x:%02x\n", rt->rtr_bus, rt->rtr_devfn);
                return;
        }

        for (h = pirq_routers; h->vendor; h++) {
                /* First look for a router match */
                if (rt->rtr_vendor == h->vendor &&
                        h->probe(r, pirq_router_dev, rt->rtr_device))
                        break;
                /* Fall back to a device match */
                if (pirq_router_dev->vendor == h->vendor &&
                        h->probe(r, pirq_router_dev, pirq_router_dev->device))
                        break;
        }
        dev_info(&pirq_router_dev->dev, "%s IRQ router [%04x:%04x]\n",
                 pirq_router.name,
                 pirq_router_dev->vendor, pirq_router_dev->device);

        /* The device remains referenced for the kernel lifetime */
}

static struct irq_info *pirq_get_info(struct pci_dev *dev)
{
        struct irq_routing_table *rt = pirq_table;
        int entries = (rt->size - sizeof(struct irq_routing_table)) /
                sizeof(struct irq_info);
        struct irq_info *info;

        for (info = rt->slots; entries--; info++)
                if (info->bus == dev->bus->number &&
                        PCI_SLOT(info->devfn) == PCI_SLOT(dev->devfn))
                        return info;
        return NULL;
}

static int pcibios_lookup_irq(struct pci_dev *dev, int assign)
{
        u8 pin;
        struct irq_info *info;
        int i, pirq, newirq;
        int irq = 0;
        u32 mask;
        struct irq_router *r = &pirq_router;
        struct pci_dev *dev2 = NULL;
        char *msg = NULL;

        /* Find IRQ pin */
        pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
        if (!pin) {
                dev_dbg(&dev->dev, "no interrupt pin\n");
                return 0;
        }

        if (io_apic_assign_pci_irqs)
                return 0;

        /* Find IRQ routing entry */

        if (!pirq_table)
                return 0;

        info = pirq_get_info(dev);
        if (!info) {
                dev_dbg(&dev->dev, "PCI INT %c not found in routing table\n",
                        'A' + pin - 1);
                return 0;
        }
        pirq = info->irq[pin - 1].link;
        mask = info->irq[pin - 1].bitmap;
        if (!pirq) {
                dev_dbg(&dev->dev, "PCI INT %c not routed\n", 'A' + pin - 1);
                return 0;
        }
        dev_dbg(&dev->dev, "PCI INT %c -> PIRQ %02x, mask %04x, excl %04x",
                'A' + pin - 1, pirq, mask, pirq_table->exclusive_irqs);
        mask &= pcibios_irq_mask;

        /* Work around broken HP Pavilion Notebooks which assign USB to
           IRQ 9 even though it is actually wired to IRQ 11 */

        if (broken_hp_bios_irq9 && pirq == 0x59 && dev->irq == 9) {
                dev->irq = 11;
                pci_write_config_byte(dev, PCI_INTERRUPT_LINE, 11);
                r->set(pirq_router_dev, dev, pirq, 11);
        }

        /* same for Acer Travelmate 360, but with CB and irq 11 -> 10 */
        if (acer_tm360_irqrouting && dev->irq == 11 &&
                dev->vendor == PCI_VENDOR_ID_O2) {
                pirq = 0x68;
                mask = 0x400;
                dev->irq = r->get(pirq_router_dev, dev, pirq);
                pci_write_config_byte(dev, PCI_INTERRUPT_LINE, dev->irq);
        }

        /*
         * Find the best IRQ to assign: use the one
         * reported by the device if possible.
         */
        newirq = dev->irq;
        if (newirq && !((1 << newirq) & mask)) {
                if (pci_probe & PCI_USE_PIRQ_MASK)
                        newirq = 0;
                else
                        dev_warn(&dev->dev, "IRQ %d doesn't match PIRQ mask "
                                 "%#x; try pci=usepirqmask\n", newirq, mask);
        }
        if (!newirq && assign) {
                for (i = 0; i < 16; i++) {
                        if (!(mask & (1 << i)))
                                continue;
                        if (pirq_penalty[i] < pirq_penalty[newirq] &&
                                can_request_irq(i, IRQF_SHARED))
                                newirq = i;
                }
        }
        dev_dbg(&dev->dev, "PCI INT %c -> newirq %d", 'A' + pin - 1, newirq);

        /* Check if it is hardcoded */
        if ((pirq & 0xf0) == 0xf0) {
                irq = pirq & 0xf;
                msg = "hardcoded";
        } else if (r->get && (irq = r->get(pirq_router_dev, dev, pirq)) && \
        ((!(pci_probe & PCI_USE_PIRQ_MASK)) || ((1 << irq) & mask))) {
                msg = "found";
                elcr_set_level_irq(irq);
        } else if (newirq && r->set &&
                (dev->class >> 8) != PCI_CLASS_DISPLAY_VGA) {
                if (r->set(pirq_router_dev, dev, pirq, newirq)) {
                        elcr_set_level_irq(newirq);
                        msg = "assigned";
                        irq = newirq;
                }
        }

        if (!irq) {
                if (newirq && mask == (1 << newirq)) {
                        msg = "guessed";
                        irq = newirq;
                } else {
                        dev_dbg(&dev->dev, "can't route interrupt\n");
                        return 0;
                }
        }
        dev_info(&dev->dev, "%s PCI INT %c -> IRQ %d\n", msg, 'A' + pin - 1, irq);

        /* Update IRQ for all devices with the same pirq value */
        for_each_pci_dev(dev2) {
                pci_read_config_byte(dev2, PCI_INTERRUPT_PIN, &pin);
                if (!pin)
                        continue;

                info = pirq_get_info(dev2);
                if (!info)
                        continue;
                if (info->irq[pin - 1].link == pirq) {

                        /*
                         * We refuse to override the dev->irq
                         * information. Give a warning!
                         */
                        if (dev2->irq && dev2->irq != irq && \
                        (!(pci_probe & PCI_USE_PIRQ_MASK) || \
                        ((1 << dev2->irq) & mask))) {
#ifndef CONFIG_PCI_MSI
                                dev_info(&dev2->dev, "IRQ routing conflict: "
                                         "have IRQ %d, want IRQ %d\n",
                                         dev2->irq, irq);
#endif
                                continue;
                        }
                        dev2->irq = irq;
                        pirq_penalty[irq]++;
                        if (dev != dev2)
                                dev_info(&dev->dev, "sharing IRQ %d with %s\n",
                                         irq, pci_name(dev2));
                }
        }
        return 1;
}

void __init pcibios_fixup_irqs(void)
{
        struct pci_dev *dev = NULL;
        u8 pin;

        DBG(KERN_DEBUG "PCI: IRQ fixup\n");
        for_each_pci_dev(dev) {
                /*
                 * If the BIOS has set an out of range IRQ number, just
                 * ignore it.  Also keep track of which IRQ's are
                 * already in use.
                 */
                if (dev->irq >= 16) {
                        dev_dbg(&dev->dev, "ignoring bogus IRQ %d\n", dev->irq);
                        dev->irq = 0;
                }
                /*
                 * If the IRQ is already assigned to a PCI device,
                 * ignore its ISA use penalty
                 */
                if (pirq_penalty[dev->irq] >= 100 &&
                                pirq_penalty[dev->irq] < 100000)
                        pirq_penalty[dev->irq] = 0;
                pirq_penalty[dev->irq]++;
        }

        if (io_apic_assign_pci_irqs)
                return;

        dev = NULL;
        for_each_pci_dev(dev) {
                pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
                if (!pin)
                        continue;

                /*
                 * Still no IRQ? Try to lookup one...
                 */
                if (!dev->irq)
                        pcibios_lookup_irq(dev, 0);
        }
}

/*
 * Work around broken HP Pavilion Notebooks which assign USB to
 * IRQ 9 even though it is actually wired to IRQ 11
 */
static int __init fix_broken_hp_bios_irq9(const struct dmi_system_id *d)
{
        if (!broken_hp_bios_irq9) {
                broken_hp_bios_irq9 = 1;
                printk(KERN_INFO "%s detected - fixing broken IRQ routing\n",
                        d->ident);
        }
        return 0;
}

/*
 * Work around broken Acer TravelMate 360 Notebooks which assign
 * Cardbus to IRQ 11 even though it is actually wired to IRQ 10
 */
static int __init fix_acer_tm360_irqrouting(const struct dmi_system_id *d)
{
        if (!acer_tm360_irqrouting) {
                acer_tm360_irqrouting = 1;
                printk(KERN_INFO "%s detected - fixing broken IRQ routing\n",
                        d->ident);
        }
        return 0;
}

static const struct dmi_system_id pciirq_dmi_table[] __initconst = {
        {
                .callback = fix_broken_hp_bios_irq9,
                .ident = "HP Pavilion N5400 Series Laptop",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
                        DMI_MATCH(DMI_BIOS_VERSION, "GE.M1.03"),
                        DMI_MATCH(DMI_PRODUCT_VERSION,
                                "HP Pavilion Notebook Model GE"),
                        DMI_MATCH(DMI_BOARD_VERSION, "OmniBook N32N-736"),
                },
        },
        {
                .callback = fix_acer_tm360_irqrouting,
                .ident = "Acer TravelMate 36x Laptop",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 360"),
                },
        },
        { }
};

void __init pcibios_irq_init(void)
{
        DBG(KERN_DEBUG "PCI: IRQ init\n");

        if (raw_pci_ops == NULL)
                return;

        dmi_check_system(pciirq_dmi_table);

        pirq_table = pirq_find_routing_table();

#ifdef CONFIG_PCI_BIOS
        if (!pirq_table && (pci_probe & PCI_BIOS_IRQ_SCAN))
                pirq_table = pcibios_get_irq_routing_table();
#endif
        if (pirq_table) {
                pirq_peer_trick();
                pirq_find_router(&pirq_router);
                if (pirq_table->exclusive_irqs) {
                        int i;
                        for (i = 0; i < 16; i++)
                                if (!(pirq_table->exclusive_irqs & (1 << i)))
                                        pirq_penalty[i] += 100;
                }
                /*
                 * If we're using the I/O APIC, avoid using the PCI IRQ
                 * routing table
                 */
                if (io_apic_assign_pci_irqs)
                        pirq_table = NULL;
        }

        x86_init.pci.fixup_irqs();

        if (io_apic_assign_pci_irqs && pci_routeirq) {
                struct pci_dev *dev = NULL;
                /*
                 * PCI IRQ routing is set up by pci_enable_device(), but we
                 * also do it here in case there are still broken drivers that
                 * don't use pci_enable_device().
                 */
                printk(KERN_INFO "PCI: Routing PCI interrupts for all devices because \"pci=routeirq\" specified\n");
                for_each_pci_dev(dev)
                        pirq_enable_irq(dev);
        }
}

static void pirq_penalize_isa_irq(int irq, int active)
{
        /*
         *  If any ISAPnP device reports an IRQ in its list of possible
         *  IRQ's, we try to avoid assigning it to PCI devices.
         */
        if (irq < 16) {
                if (active)
                        pirq_penalty[irq] += 1000;
                else
                        pirq_penalty[irq] += 100;
        }
}

void pcibios_penalize_isa_irq(int irq, int active)
{
#ifdef CONFIG_ACPI
        if (!acpi_noirq)
                acpi_penalize_isa_irq(irq, active);
        else
#endif
                pirq_penalize_isa_irq(irq, active);
}

static int pirq_enable_irq(struct pci_dev *dev)
{
        u8 pin = 0;

        pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
        if (pin && !pcibios_lookup_irq(dev, 1)) {
                char *msg = "";

                if (!io_apic_assign_pci_irqs && dev->irq)
                        return 0;

                if (io_apic_assign_pci_irqs) {
#ifdef CONFIG_X86_IO_APIC
                        struct pci_dev *temp_dev;
                        int irq;

                        if (dev->irq_managed && dev->irq > 0)
                                return 0;

                        irq = IO_APIC_get_PCI_irq_vector(dev->bus->number,
                                                PCI_SLOT(dev->devfn), pin - 1);
                        /*
                         * Busses behind bridges are typically not listed in the MP-table.
                         * In this case we have to look up the IRQ based on the parent bus,
                         * parent slot, and pin number. The SMP code detects such bridged
                         * busses itself so we should get into this branch reliably.
                         */
                        temp_dev = dev;
                        while (irq < 0 && dev->bus->parent) { /* go back to the bridge */
                                struct pci_dev *bridge = dev->bus->self;

                                pin = pci_swizzle_interrupt_pin(dev, pin);
                                irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
                                                PCI_SLOT(bridge->devfn),
                                                pin - 1);
                                if (irq >= 0)
                                        dev_warn(&dev->dev, "using bridge %s "
                                                 "INT %c to get IRQ %d\n",
                                                 pci_name(bridge), 'A' + pin - 1,
                                                 irq);
                                dev = bridge;
                        }
                        dev = temp_dev;
                        if (irq >= 0) {
                                dev->irq_managed = 1;
                                dev->irq = irq;
                                dev_info(&dev->dev, "PCI->APIC IRQ transform: "
                                         "INT %c -> IRQ %d\n", 'A' + pin - 1, irq);
                                return 0;
                        } else
                                msg = "; probably buggy MP table";
#endif
                } else if (pci_probe & PCI_BIOS_IRQ_SCAN)
                        msg = "";
                else
                        msg = "; please try using pci=biosirq";

                /*
                 * With IDE legacy devices the IRQ lookup failure is not
                 * a problem..
                 */
                if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE &&
                                !(dev->class & 0x5))
                        return 0;

                dev_warn(&dev->dev, "can't find IRQ for PCI INT %c%s\n",
                         'A' + pin - 1, msg);
        }
        return 0;
}

bool mp_should_keep_irq(struct device *dev)
{
        if (dev->power.is_prepared)
                return true;
#ifdef CONFIG_PM
        if (dev->power.runtime_status == RPM_SUSPENDING)
                return true;
#endif

        return false;
}

static void pirq_disable_irq(struct pci_dev *dev)
{
        if (io_apic_assign_pci_irqs && !mp_should_keep_irq(&dev->dev) &&
            dev->irq_managed && dev->irq) {
                mp_unmap_irq(dev->irq);
                dev->irq = 0;
                dev->irq_managed = 0;
        }
}