// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Support for PCI bridges found on Power Macintoshes.
 *
 * Copyright (C) 2003-2005 Benjamin Herrenschmuidt (benh@kernel.crashing.org)
 * Copyright (C) 1997 Paul Mackerras (paulus@samba.org)
 */

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/of_pci.h>

#include <asm/sections.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#include <asm/machdep.h>
#include <asm/pmac_feature.h>
#include <asm/grackle.h>
#include <asm/ppc-pci.h>

#include "pmac.h"

#undef DEBUG

#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif

/* XXX Could be per-controller, but I don't think we risk anything by
 * assuming we won't have both UniNorth and Bandit */
static int has_uninorth;
#ifdef CONFIG_PPC64
static struct pci_controller *u3_agp;
#else
static int has_second_ohare;
#endif /* CONFIG_PPC64 */

extern int pcibios_assign_bus_offset;

struct device_node *k2_skiplist[2];

/*
 * Magic constants for enabling cache coherency in the bandit/PSX bridge.
 */
#define BANDIT_DEVID_2  8
#define BANDIT_REVID    3

#define BANDIT_DEVNUM   11
#define BANDIT_MAGIC    0x50
#define BANDIT_COHERENT 0x40

static int __init fixup_one_level_bus_range(struct device_node *node, int higher)
{
        for (; node; node = node->sibling) {
                const int * bus_range;
                const unsigned int *class_code;
                int len;

                /* For PCI<->PCI bridges or CardBus bridges, we go down */
                class_code = of_get_property(node, "class-code", NULL);
                if (!class_code || ((*class_code >> 8) != PCI_CLASS_BRIDGE_PCI &&
                        (*class_code >> 8) != PCI_CLASS_BRIDGE_CARDBUS))
                        continue;
                bus_range = of_get_property(node, "bus-range", &len);
                if (bus_range != NULL && len > 2 * sizeof(int)) {
                        if (bus_range[1] > higher)
                                higher = bus_range[1];
                }
                higher = fixup_one_level_bus_range(node->child, higher);
        }
        return higher;
}

/* This routine fixes the "bus-range" property of all bridges in the
 * system since they tend to have their "last" member wrong on macs
 *
 * Note that the bus numbers manipulated here are OF bus numbers, they
 * are not Linux bus numbers.
 */
static void __init fixup_bus_range(struct device_node *bridge)
{
        int *bus_range, len;
        struct property *prop;

        /* Lookup the "bus-range" property for the hose */
        prop = of_find_property(bridge, "bus-range", &len);
        if (prop == NULL || prop->length < 2 * sizeof(int))
                return;

        bus_range = prop->value;
        bus_range[1] = fixup_one_level_bus_range(bridge->child, bus_range[1]);
}

/*
 * Apple MacRISC (U3, UniNorth, Bandit, Chaos) PCI controllers.
 *
 * The "Bandit" version is present in all early PCI PowerMacs,
 * and up to the first ones using Grackle. Some machines may
 * have 2 bandit controllers (2 PCI busses).
 *
 * "Chaos" is used in some "Bandit"-type machines as a bridge
 * for the separate display bus. It is accessed the same
 * way as bandit, but cannot be probed for devices. It therefore
 * has its own config access functions.
 *
 * The "UniNorth" version is present in all Core99 machines
 * (iBook, G4, new IMacs, and all the recent Apple machines).
 * It contains 3 controllers in one ASIC.
 *
 * The U3 is the bridge used on G5 machines. It contains an
 * AGP bus which is dealt with the old UniNorth access routines
 * and a HyperTransport bus which uses its own set of access
 * functions.
 */

#define MACRISC_CFA0(devfn, off)        \
        ((1 << (unsigned int)PCI_SLOT(dev_fn)) \
        | (((unsigned int)PCI_FUNC(dev_fn)) << 8) \
        | (((unsigned int)(off)) & 0xFCUL))

#define MACRISC_CFA1(bus, devfn, off)   \
        ((((unsigned int)(bus)) << 16) \
        |(((unsigned int)(devfn)) << 8) \
        |(((unsigned int)(off)) & 0xFCUL) \
        |1UL)

static void __iomem *macrisc_cfg_map_bus(struct pci_bus *bus,
                                         unsigned int dev_fn,
                                         int offset)
{
        unsigned int caddr;
        struct pci_controller *hose;

        hose = pci_bus_to_host(bus);
        if (hose == NULL)
                return NULL;

        if (bus->number == hose->first_busno) {
                if (dev_fn < (11 << 3))
                        return NULL;
                caddr = MACRISC_CFA0(dev_fn, offset);
        } else
                caddr = MACRISC_CFA1(bus->number, dev_fn, offset);

        /* Uninorth will return garbage if we don't read back the value ! */
        do {
                out_le32(hose->cfg_addr, caddr);
        } while (in_le32(hose->cfg_addr) != caddr);

        offset &= has_uninorth ? 0x07 : 0x03;
        return hose->cfg_data + offset;
}

static struct pci_ops macrisc_pci_ops =
{
        .map_bus = macrisc_cfg_map_bus,
        .read = pci_generic_config_read,
        .write = pci_generic_config_write,
};

#ifdef CONFIG_PPC32
/*
 * Verify that a specific (bus, dev_fn) exists on chaos
 */
static void __iomem *chaos_map_bus(struct pci_bus *bus, unsigned int devfn,
                                   int offset)
{
        struct device_node *np;
        const u32 *vendor, *device;

        if (offset >= 0x100)
                return NULL;
        np = of_pci_find_child_device(bus->dev.of_node, devfn);
        if (np == NULL)
                return NULL;

        vendor = of_get_property(np, "vendor-id", NULL);
        device = of_get_property(np, "device-id", NULL);
        if (vendor == NULL || device == NULL)
                return NULL;

        if ((*vendor == 0x106b) && (*device == 3) && (offset >= 0x10)
            && (offset != 0x14) && (offset != 0x18) && (offset <= 0x24))
                return NULL;

        return macrisc_cfg_map_bus(bus, devfn, offset);
}

static struct pci_ops chaos_pci_ops =
{
        .map_bus = chaos_map_bus,
        .read = pci_generic_config_read,
        .write = pci_generic_config_write,
};

static void __init setup_chaos(struct pci_controller *hose,
                               struct resource *addr)
{
        /* assume a `chaos' bridge */
        hose->ops = &chaos_pci_ops;
        hose->cfg_addr = ioremap(addr->start + 0x800000, 0x1000);
        hose->cfg_data = ioremap(addr->start + 0xc00000, 0x1000);
}
#endif /* CONFIG_PPC32 */

#ifdef CONFIG_PPC64
/*
 * These versions of U3 HyperTransport config space access ops do not
 * implement self-view of the HT host yet
 */

/*
 * This function deals with some "special cases" devices.
 *
 *  0 -> No special case
 *  1 -> Skip the device but act as if the access was successful
 *       (return 0xff's on reads, eventually, cache config space
 *       accesses in a later version)
 * -1 -> Hide the device (unsuccessful access)
 */
static int u3_ht_skip_device(struct pci_controller *hose,
                             struct pci_bus *bus, unsigned int devfn)
{
        struct device_node *busdn, *dn;
        int i;

        /* We only allow config cycles to devices that are in OF device-tree
         * as we are apparently having some weird things going on with some
         * revs of K2 on recent G5s, except for the host bridge itself, which
         * is missing from the tree but we know we can probe.
         */
        if (bus->self)
                busdn = pci_device_to_OF_node(bus->self);
        else if (devfn == 0)
                return 0;
        else
                busdn = hose->dn;
        for (dn = busdn->child; dn; dn = dn->sibling)
                if (PCI_DN(dn) && PCI_DN(dn)->devfn == devfn)
                        break;
        if (dn == NULL)
                return -1;

        /*
         * When a device in K2 is powered down, we die on config
         * cycle accesses. Fix that here.
         */
        for (i=0; i<2; i++)
                if (k2_skiplist[i] == dn)
                        return 1;

        return 0;
}

#define U3_HT_CFA0(devfn, off)          \
                ((((unsigned int)devfn) << 8) | offset)
#define U3_HT_CFA1(bus, devfn, off)     \
                (U3_HT_CFA0(devfn, off) \
                + (((unsigned int)bus) << 16) \
                + 0x01000000UL)

static void __iomem *u3_ht_cfg_access(struct pci_controller *hose, u8 bus,
                                      u8 devfn, u8 offset, int *swap)
{
        *swap = 1;
        if (bus == hose->first_busno) {
                if (devfn != 0)
                        return hose->cfg_data + U3_HT_CFA0(devfn, offset);
                *swap = 0;
                return ((void __iomem *)hose->cfg_addr) + (offset << 2);
        } else
                return hose->cfg_data + U3_HT_CFA1(bus, devfn, offset);
}

static int u3_ht_read_config(struct pci_bus *bus, unsigned int devfn,
                                    int offset, int len, u32 *val)
{
        struct pci_controller *hose;
        void __iomem *addr;
        int swap;

        hose = pci_bus_to_host(bus);
        if (hose == NULL)
                return PCIBIOS_DEVICE_NOT_FOUND;
        if (offset >= 0x100)
                return  PCIBIOS_BAD_REGISTER_NUMBER;
        addr = u3_ht_cfg_access(hose, bus->number, devfn, offset, &swap);
        if (!addr)
                return PCIBIOS_DEVICE_NOT_FOUND;

        switch (u3_ht_skip_device(hose, bus, devfn)) {
        case 0:
                break;
        case 1:
                switch (len) {
                case 1:
                        *val = 0xff; break;
                case 2:
                        *val = 0xffff; break;
                default:
                        *val = 0xfffffffful; break;
                }
                return PCIBIOS_SUCCESSFUL;
        default:
                return PCIBIOS_DEVICE_NOT_FOUND;
        }

        /*
         * Note: the caller has already checked that offset is
         * suitably aligned and that len is 1, 2 or 4.
         */
        switch (len) {
        case 1:
                *val = in_8(addr);
                break;
        case 2:
                *val = swap ? in_le16(addr) : in_be16(addr);
                break;
        default:
                *val = swap ? in_le32(addr) : in_be32(addr);
                break;
        }
        return PCIBIOS_SUCCESSFUL;
}

static int u3_ht_write_config(struct pci_bus *bus, unsigned int devfn,
                                     int offset, int len, u32 val)
{
        struct pci_controller *hose;
        void __iomem *addr;
        int swap;

        hose = pci_bus_to_host(bus);
        if (hose == NULL)
                return PCIBIOS_DEVICE_NOT_FOUND;
        if (offset >= 0x100)
                return  PCIBIOS_BAD_REGISTER_NUMBER;
        addr = u3_ht_cfg_access(hose, bus->number, devfn, offset, &swap);
        if (!addr)
                return PCIBIOS_DEVICE_NOT_FOUND;

        switch (u3_ht_skip_device(hose, bus, devfn)) {
        case 0:
                break;
        case 1:
                return PCIBIOS_SUCCESSFUL;
        default:
                return PCIBIOS_DEVICE_NOT_FOUND;
        }

        /*
         * Note: the caller has already checked that offset is
         * suitably aligned and that len is 1, 2 or 4.
         */
        switch (len) {
        case 1:
                out_8(addr, val);
                break;
        case 2:
                swap ? out_le16(addr, val) : out_be16(addr, val);
                break;
        default:
                swap ? out_le32(addr, val) : out_be32(addr, val);
                break;
        }
        return PCIBIOS_SUCCESSFUL;
}

static struct pci_ops u3_ht_pci_ops =
{
        .read = u3_ht_read_config,
        .write = u3_ht_write_config,
};

#define U4_PCIE_CFA0(devfn, off)        \
        ((1 << ((unsigned int)PCI_SLOT(dev_fn)))        \
         | (((unsigned int)PCI_FUNC(dev_fn)) << 8)      \
         | ((((unsigned int)(off)) >> 8) << 28) \
         | (((unsigned int)(off)) & 0xfcU))

#define U4_PCIE_CFA1(bus, devfn, off)   \
        ((((unsigned int)(bus)) << 16) \
         |(((unsigned int)(devfn)) << 8)        \
         | ((((unsigned int)(off)) >> 8) << 28) \
         |(((unsigned int)(off)) & 0xfcU)       \
         |1UL)

static void __iomem *u4_pcie_cfg_map_bus(struct pci_bus *bus,
                                         unsigned int dev_fn,
                                         int offset)
{
        struct pci_controller *hose;
        unsigned int caddr;

        if (offset >= 0x1000)
                return NULL;

        hose = pci_bus_to_host(bus);
        if (!hose)
                return NULL;

        if (bus->number == hose->first_busno) {
                caddr = U4_PCIE_CFA0(dev_fn, offset);
        } else
                caddr = U4_PCIE_CFA1(bus->number, dev_fn, offset);

        /* Uninorth will return garbage if we don't read back the value ! */
        do {
                out_le32(hose->cfg_addr, caddr);
        } while (in_le32(hose->cfg_addr) != caddr);

        offset &= 0x03;
        return hose->cfg_data + offset;
}

static struct pci_ops u4_pcie_pci_ops =
{
        .map_bus = u4_pcie_cfg_map_bus,
        .read = pci_generic_config_read,
        .write = pci_generic_config_write,
};

static void pmac_pci_fixup_u4_of_node(struct pci_dev *dev)
{
        /* Apple's device-tree "hides" the root complex virtual P2P bridge
         * on U4. However, Linux sees it, causing the PCI <-> OF matching
         * code to fail to properly match devices below it. This works around
         * it by setting the node of the bridge to point to the PHB node,
         * which is not entirely correct but fixes the matching code and
         * doesn't break anything else. It's also the simplest possible fix.
         */
        if (dev->dev.of_node == NULL)
                dev->dev.of_node = pcibios_get_phb_of_node(dev->bus);
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_APPLE, 0x5b, pmac_pci_fixup_u4_of_node);

#endif /* CONFIG_PPC64 */

#ifdef CONFIG_PPC32
/*
 * For a bandit bridge, turn on cache coherency if necessary.
 * N.B. we could clean this up using the hose ops directly.
 */
static void __init init_bandit(struct pci_controller *bp)
{
        unsigned int vendev, magic;
        int rev;

        /* read the word at offset 0 in config space for device 11 */
        out_le32(bp->cfg_addr, (1UL << BANDIT_DEVNUM) + PCI_VENDOR_ID);
        udelay(2);
        vendev = in_le32(bp->cfg_data);
        if (vendev == (PCI_DEVICE_ID_APPLE_BANDIT << 16) +
                        PCI_VENDOR_ID_APPLE) {
                /* read the revision id */
                out_le32(bp->cfg_addr,
                         (1UL << BANDIT_DEVNUM) + PCI_REVISION_ID);
                udelay(2);
                rev = in_8(bp->cfg_data);
                if (rev != BANDIT_REVID)
                        printk(KERN_WARNING
                               "Unknown revision %d for bandit\n", rev);
        } else if (vendev != (BANDIT_DEVID_2 << 16) + PCI_VENDOR_ID_APPLE) {
                printk(KERN_WARNING "bandit isn't? (%x)\n", vendev);
                return;
        }

        /* read the word at offset 0x50 */
        out_le32(bp->cfg_addr, (1UL << BANDIT_DEVNUM) + BANDIT_MAGIC);
        udelay(2);
        magic = in_le32(bp->cfg_data);
        if ((magic & BANDIT_COHERENT) != 0)
                return;
        magic |= BANDIT_COHERENT;
        udelay(2);
        out_le32(bp->cfg_data, magic);
        printk(KERN_INFO "Cache coherency enabled for bandit/PSX\n");
}

/*
 * Tweak the PCI-PCI bridge chip on the blue & white G3s.
 */
static void __init init_p2pbridge(void)
{
        struct device_node *p2pbridge;
        struct pci_controller* hose;
        u8 bus, devfn;
        u16 val;

        /* XXX it would be better here to identify the specific
           PCI-PCI bridge chip we have. */
        p2pbridge = of_find_node_by_name(NULL, "pci-bridge");
        if (p2pbridge == NULL || !of_node_name_eq(p2pbridge->parent, "pci"))
                goto done;
        if (pci_device_from_OF_node(p2pbridge, &bus, &devfn) < 0) {
                DBG("Can't find PCI infos for PCI<->PCI bridge\n");
                goto done;
        }
        /* Warning: At this point, we have not yet renumbered all busses.
         * So we must use OF walking to find out hose
         */
        hose = pci_find_hose_for_OF_device(p2pbridge);
        if (!hose) {
                DBG("Can't find hose for PCI<->PCI bridge\n");
                goto done;
        }
        if (early_read_config_word(hose, bus, devfn,
                                   PCI_BRIDGE_CONTROL, &val) < 0) {
                printk(KERN_ERR "init_p2pbridge: couldn't read bridge"
                       " control\n");
                goto done;
        }
        val &= ~PCI_BRIDGE_CTL_MASTER_ABORT;
        early_write_config_word(hose, bus, devfn, PCI_BRIDGE_CONTROL, val);
done:
        of_node_put(p2pbridge);
}

static void __init init_second_ohare(void)
{
        struct device_node *np = of_find_node_by_name(NULL, "pci106b,7");
        unsigned char bus, devfn;
        unsigned short cmd;

        if (np == NULL)
                return;

        /* This must run before we initialize the PICs since the second
         * ohare hosts a PIC that will be accessed there.
         */
        if (pci_device_from_OF_node(np, &bus, &devfn) == 0) {
                struct pci_controller* hose =
                        pci_find_hose_for_OF_device(np);
                if (!hose) {
                        printk(KERN_ERR "Can't find PCI hose for OHare2 !\n");
                        of_node_put(np);
                        return;
                }
                early_read_config_word(hose, bus, devfn, PCI_COMMAND, &cmd);
                cmd |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER;
                cmd &= ~PCI_COMMAND_IO;
                early_write_config_word(hose, bus, devfn, PCI_COMMAND, cmd);
        }
        has_second_ohare = 1;
        of_node_put(np);
}

/*
 * Some Apple desktop machines have a NEC PD720100A USB2 controller
 * on the motherboard. Open Firmware, on these, will disable the
 * EHCI part of it so it behaves like a pair of OHCI's. This fixup
 * code re-enables it ;)
 */
static void __init fixup_nec_usb2(void)
{
        struct device_node *nec;

        for_each_node_by_name(nec, "usb") {
                struct pci_controller *hose;
                u32 data;
                const u32 *prop;
                u8 bus, devfn;

                prop = of_get_property(nec, "vendor-id", NULL);
                if (prop == NULL)
                        continue;
                if (0x1033 != *prop)
                        continue;
                prop = of_get_property(nec, "device-id", NULL);
                if (prop == NULL)
                        continue;
                if (0x0035 != *prop)
                        continue;
                prop = of_get_property(nec, "reg", NULL);
                if (prop == NULL)
                        continue;
                devfn = (prop[0] >> 8) & 0xff;
                bus = (prop[0] >> 16) & 0xff;
                if (PCI_FUNC(devfn) != 0)
                        continue;
                hose = pci_find_hose_for_OF_device(nec);
                if (!hose)
                        continue;
                early_read_config_dword(hose, bus, devfn, 0xe4, &data);
                if (data & 1UL) {
                        printk("Found NEC PD720100A USB2 chip with disabled"
                               " EHCI, fixing up...\n");
                        data &= ~1UL;
                        early_write_config_dword(hose, bus, devfn, 0xe4, data);
                }
        }
}

static void __init setup_bandit(struct pci_controller *hose,
                                struct resource *addr)
{
        hose->ops = &macrisc_pci_ops;
        hose->cfg_addr = ioremap(addr->start + 0x800000, 0x1000);
        hose->cfg_data = ioremap(addr->start + 0xc00000, 0x1000);
        init_bandit(hose);
}

static int __init setup_uninorth(struct pci_controller *hose,
                                 struct resource *addr)
{
        pci_add_flags(PCI_REASSIGN_ALL_BUS);
        has_uninorth = 1;
        hose->ops = &macrisc_pci_ops;
        hose->cfg_addr = ioremap(addr->start + 0x800000, 0x1000);
        hose->cfg_data = ioremap(addr->start + 0xc00000, 0x1000);
        /* We "know" that the bridge at f2000000 has the PCI slots. */
        return addr->start == 0xf2000000;
}
#endif /* CONFIG_PPC32 */

#ifdef CONFIG_PPC64
static void __init setup_u3_agp(struct pci_controller* hose)
{
        /* On G5, we move AGP up to high bus number so we don't need
         * to reassign bus numbers for HT. If we ever have P2P bridges
         * on AGP, we'll have to move pci_assign_all_busses to the
         * pci_controller structure so we enable it for AGP and not for
         * HT childs.
         * We hard code the address because of the different size of
         * the reg address cell, we shall fix that by killing struct
         * reg_property and using some accessor functions instead
         */
        hose->first_busno = 0xf0;
        hose->last_busno = 0xff;
        has_uninorth = 1;
        hose->ops = &macrisc_pci_ops;
        hose->cfg_addr = ioremap(0xf0000000 + 0x800000, 0x1000);
        hose->cfg_data = ioremap(0xf0000000 + 0xc00000, 0x1000);
        u3_agp = hose;
}

static void __init setup_u4_pcie(struct pci_controller* hose)
{
        /* We currently only implement the "non-atomic" config space, to
         * be optimised later.
         */
        hose->ops = &u4_pcie_pci_ops;
        hose->cfg_addr = ioremap(0xf0000000 + 0x800000, 0x1000);
        hose->cfg_data = ioremap(0xf0000000 + 0xc00000, 0x1000);

        /* The bus contains a bridge from root -> device, we need to
         * make it visible on bus 0 so that we pick the right type
         * of config cycles. If we didn't, we would have to force all
         * config cycles to be type 1. So we override the "bus-range"
         * property here
         */
        hose->first_busno = 0x00;
        hose->last_busno = 0xff;
}

static void __init parse_region_decode(struct pci_controller *hose,
                                       u32 decode)
{
        unsigned long base, end, next = -1;
        int i, cur = -1;

        /* Iterate through all bits. We ignore the last bit as this region is
         * reserved for the ROM among other niceties
         */
        for (i = 0; i < 31; i++) {
                if ((decode & (0x80000000 >> i)) == 0)
                        continue;
                if (i < 16) {
                        base = 0xf0000000 | (((u32)i) << 24);
                        end = base + 0x00ffffff;
                } else {
                        base = ((u32)i-16) << 28;
                        end = base + 0x0fffffff;
                }
                if (base != next) {
                        if (++cur >= 3) {
                                printk(KERN_WARNING "PCI: Too many ranges !\n");
                                break;
                        }
                        hose->mem_resources[cur].flags = IORESOURCE_MEM;
                        hose->mem_resources[cur].name = hose->dn->full_name;
                        hose->mem_resources[cur].start = base;
                        hose->mem_resources[cur].end = end;
                        hose->mem_offset[cur] = 0;
                        DBG("  %d: 0x%08lx-0x%08lx\n", cur, base, end);
                } else {
                        DBG("   :           -0x%08lx\n", end);
                        hose->mem_resources[cur].end = end;
                }
                next = end + 1;
        }
}

static void __init setup_u3_ht(struct pci_controller* hose)
{
        struct device_node *np = hose->dn;
        struct resource cfg_res, self_res;
        u32 decode;

        hose->ops = &u3_ht_pci_ops;

        /* Get base addresses from OF tree
         */
        if (of_address_to_resource(np, 0, &cfg_res) ||
            of_address_to_resource(np, 1, &self_res)) {
                printk(KERN_ERR "PCI: Failed to get U3/U4 HT resources !\n");
                return;
        }

        /* Map external cfg space access into cfg_data and self registers
         * into cfg_addr
         */
        hose->cfg_data = ioremap(cfg_res.start, 0x02000000);
        hose->cfg_addr = ioremap(self_res.start, resource_size(&self_res));

        /*
         * /ht node doesn't expose a "ranges" property, we read the register
         * that controls the decoding logic and use that for memory regions.
         * The IO region is hard coded since it is fixed in HW as well.
         */
        hose->io_base_phys = 0xf4000000;
        hose->pci_io_size = 0x00400000;
        hose->io_resource.name = np->full_name;
        hose->io_resource.start = 0;
        hose->io_resource.end = 0x003fffff;
        hose->io_resource.flags = IORESOURCE_IO;
        hose->first_busno = 0;
        hose->last_busno = 0xef;

        /* Note: fix offset when cfg_addr becomes a void * */
        decode = in_be32(hose->cfg_addr + 0x80);

        DBG("PCI: Apple HT bridge decode register: 0x%08x\n", decode);

        /* NOTE: The decode register setup is a bit weird... region
         * 0xf8000000 for example is marked as enabled in there while it's
         & actually the memory controller registers.
         * That means that we are incorrectly attributing it to HT.
         *
         * In a similar vein, region 0xf4000000 is actually the HT IO space but
         * also marked as enabled in here and 0xf9000000 is used by some other
         * internal bits of the northbridge.
         *
         * Unfortunately, we can't just mask out those bit as we would end
         * up with more regions than we can cope (linux can only cope with
         * 3 memory regions for a PHB at this stage).
         *
         * So for now, we just do a little hack. We happen to -know- that
         * Apple firmware doesn't assign things below 0xfa000000 for that
         * bridge anyway so we mask out all bits we don't want.
         */
        decode &= 0x003fffff;

        /* Now parse the resulting bits and build resources */
        parse_region_decode(hose, decode);
}
#endif /* CONFIG_PPC64 */

/*
 * We assume that if we have a G3 powermac, we have one bridge called
 * "pci" (a MPC106) and no bandit or chaos bridges, and contrariwise,
 * if we have one or more bandit or chaos bridges, we don't have a MPC106.
 */
static int __init pmac_add_bridge(struct device_node *dev)
{
        int len;
        struct pci_controller *hose;
        struct resource rsrc;
        char *disp_name;
        const int *bus_range;
        int primary = 1;

        DBG("Adding PCI host bridge %pOF\n", dev);

        /* Fetch host bridge registers address */
        of_address_to_resource(dev, 0, &rsrc);

        /* Get bus range if any */
        bus_range = of_get_property(dev, "bus-range", &len);
        if (bus_range == NULL || len < 2 * sizeof(int)) {
                printk(KERN_WARNING "Can't get bus-range for %pOF, assume"
                       " bus 0\n", dev);
        }

        hose = pcibios_alloc_controller(dev);
        if (!hose)
                return -ENOMEM;
        hose->first_busno = bus_range ? bus_range[0] : 0;
        hose->last_busno = bus_range ? bus_range[1] : 0xff;
        hose->controller_ops = pmac_pci_controller_ops;

        disp_name = NULL;

        /* 64 bits only bridges */
#ifdef CONFIG_PPC64
        if (of_device_is_compatible(dev, "u3-agp")) {
                setup_u3_agp(hose);
                disp_name = "U3-AGP";
                primary = 0;
        } else if (of_device_is_compatible(dev, "u3-ht")) {
                setup_u3_ht(hose);
                disp_name = "U3-HT";
                primary = 1;
        } else if (of_device_is_compatible(dev, "u4-pcie")) {
                setup_u4_pcie(hose);
                disp_name = "U4-PCIE";
                primary = 0;
        }
        printk(KERN_INFO "Found %s PCI host bridge.  Firmware bus number:"
               " %d->%d\n", disp_name, hose->first_busno, hose->last_busno);
#endif /* CONFIG_PPC64 */

        /* 32 bits only bridges */
#ifdef CONFIG_PPC32
        if (of_device_is_compatible(dev, "uni-north")) {
                primary = setup_uninorth(hose, &rsrc);
                disp_name = "UniNorth";
        } else if (of_node_name_eq(dev, "pci")) {
                /* XXX assume this is a mpc106 (grackle) */
                setup_grackle(hose);
                disp_name = "Grackle (MPC106)";
        } else if (of_node_name_eq(dev, "bandit")) {
                setup_bandit(hose, &rsrc);
                disp_name = "Bandit";
        } else if (of_node_name_eq(dev, "chaos")) {
                setup_chaos(hose, &rsrc);
                disp_name = "Chaos";
                primary = 0;
        }
        printk(KERN_INFO "Found %s PCI host bridge at 0x%016llx. "
               "Firmware bus number: %d->%d\n",
                disp_name, (unsigned long long)rsrc.start, hose->first_busno,
                hose->last_busno);
#endif /* CONFIG_PPC32 */

        DBG(" ->Hose at 0x%p, cfg_addr=0x%p,cfg_data=0x%p\n",
                hose, hose->cfg_addr, hose->cfg_data);

        /* Interpret the "ranges" property */
        /* This also maps the I/O region and sets isa_io/mem_base */
        pci_process_bridge_OF_ranges(hose, dev, primary);

        /* Fixup "bus-range" OF property */
        fixup_bus_range(dev);

        /* create pci_dn's for DT nodes under this PHB */
        if (IS_ENABLED(CONFIG_PPC64))
                pci_devs_phb_init_dynamic(hose);

        return 0;
}

void pmac_pci_irq_fixup(struct pci_dev *dev)
{
#ifdef CONFIG_PPC32
        /* Fixup interrupt for the modem/ethernet combo controller.
         * on machines with a second ohare chip.
         * The number in the device tree (27) is bogus (correct for
         * the ethernet-only board but not the combo ethernet/modem
         * board). The real interrupt is 28 on the second controller
         * -> 28+32 = 60.
         */
        if (has_second_ohare &&
            dev->vendor == PCI_VENDOR_ID_DEC &&
            dev->device == PCI_DEVICE_ID_DEC_TULIP_PLUS) {
                dev->irq = irq_create_mapping(NULL, 60);
                irq_set_irq_type(dev->irq, IRQ_TYPE_LEVEL_LOW);
        }
#endif /* CONFIG_PPC32 */
}

#ifdef CONFIG_PPC64
static int pmac_pci_root_bridge_prepare(struct pci_host_bridge *bridge)
{
        struct pci_controller *hose = pci_bus_to_host(bridge->bus);
        struct device_node *np, *child;

        if (hose != u3_agp)
                return 0;

        /* Fixup the PCI<->OF mapping for U3 AGP due to bus renumbering. We
         * assume there is no P2P bridge on the AGP bus, which should be a
         * safe assumptions for now. We should do something better in the
         * future though
         */
        np = hose->dn;
        PCI_DN(np)->busno = 0xf0;
        for_each_child_of_node(np, child)
                PCI_DN(child)->busno = 0xf0;

        return 0;
}
#endif /* CONFIG_PPC64 */

void __init pmac_pci_init(void)
{
        struct device_node *np, *root;
        struct device_node *ht __maybe_unused = NULL;

        pci_set_flags(PCI_CAN_SKIP_ISA_ALIGN);

        root = of_find_node_by_path("/");
        if (root == NULL) {
                printk(KERN_CRIT "pmac_pci_init: can't find root "
                       "of device tree\n");
                return;
        }
        for_each_child_of_node(root, np) {
                if (of_node_name_eq(np, "bandit")
                    || of_node_name_eq(np, "chaos")
                    || of_node_name_eq(np, "pci")) {
                        if (pmac_add_bridge(np) == 0)
                                of_node_get(np);
                }
                if (of_node_name_eq(np, "ht")) {
                        of_node_get(np);
                        ht = np;
                }
        }
        of_node_put(root);

#ifdef CONFIG_PPC64
        /* Probe HT last as it relies on the agp resources to be already
         * setup
         */
        if (ht && pmac_add_bridge(ht) != 0)
                of_node_put(ht);

        ppc_md.pcibios_root_bridge_prepare = pmac_pci_root_bridge_prepare;
        /* pmac_check_ht_link(); */

#else /* CONFIG_PPC64 */
        init_p2pbridge();
        init_second_ohare();
        fixup_nec_usb2();

        /* We are still having some issues with the Xserve G4, enabling
         * some offset between bus number and domains for now when we
         * assign all busses should help for now
         */
        if (pci_has_flag(PCI_REASSIGN_ALL_BUS))
                pcibios_assign_bus_offset = 0x10;
#endif
}

#ifdef CONFIG_PPC32
static bool pmac_pci_enable_device_hook(struct pci_dev *dev)
{
        struct device_node* node;
        int updatecfg = 0;
        int uninorth_child;

        node = pci_device_to_OF_node(dev);

        /* We don't want to enable USB controllers absent from the OF tree
         * (iBook second controller)
         */
        if (dev->vendor == PCI_VENDOR_ID_APPLE
            && dev->class == PCI_CLASS_SERIAL_USB_OHCI
            && !node) {
                printk(KERN_INFO "Apple USB OHCI %s disabled by firmware\n",
                       pci_name(dev));
                return false;
        }

        if (!node)
                return true;

        uninorth_child = node->parent &&
                of_device_is_compatible(node->parent, "uni-north");

        /* Firewire & GMAC were disabled after PCI probe, the driver is
         * claiming them, we must re-enable them now.
         */
        if (uninorth_child && of_node_name_eq(node, "firewire") &&
            (of_device_is_compatible(node, "pci106b,18") ||
             of_device_is_compatible(node, "pci106b,30") ||
             of_device_is_compatible(node, "pci11c1,5811"))) {
                pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, node, 0, 1);
                pmac_call_feature(PMAC_FTR_1394_ENABLE, node, 0, 1);
                updatecfg = 1;
        }
        if (uninorth_child && of_node_name_eq(node, "ethernet") &&
            of_device_is_compatible(node, "gmac")) {
                pmac_call_feature(PMAC_FTR_GMAC_ENABLE, node, 0, 1);
                updatecfg = 1;
        }

        /*
         * Fixup various header fields on 32 bits. We don't do that on
         * 64 bits as some of these have strange values behind the HT
         * bridge and we must not, for example, enable MWI or set the
         * cache line size on them.

         */
        if (updatecfg) {
                u16 cmd;

                pci_read_config_word(dev, PCI_COMMAND, &cmd);
                cmd |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER
                        | PCI_COMMAND_INVALIDATE;
                pci_write_config_word(dev, PCI_COMMAND, cmd);
                pci_write_config_byte(dev, PCI_LATENCY_TIMER, 16);

                pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE,
                                      L1_CACHE_BYTES >> 2);
        }

        return true;
}

static void pmac_pci_fixup_ohci(struct pci_dev *dev)
{
        struct device_node *node = pci_device_to_OF_node(dev);

        /* We don't want to assign resources to USB controllers
         * absent from the OF tree (iBook second controller)
         */
        if (dev->class == PCI_CLASS_SERIAL_USB_OHCI && !node)
                dev->resource[0].flags = 0;
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_APPLE, PCI_ANY_ID, pmac_pci_fixup_ohci);

/* We power down some devices after they have been probed. They'll
 * be powered back on later on
 */
void __init pmac_pcibios_after_init(void)
{
        struct device_node* nd;

        for_each_node_by_name(nd, "firewire") {
                if (nd->parent && (of_device_is_compatible(nd, "pci106b,18") ||
                                   of_device_is_compatible(nd, "pci106b,30") ||
                                   of_device_is_compatible(nd, "pci11c1,5811"))
                    && of_device_is_compatible(nd->parent, "uni-north")) {
                        pmac_call_feature(PMAC_FTR_1394_ENABLE, nd, 0, 0);
                        pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, nd, 0, 0);
                }
        }
        for_each_node_by_name(nd, "ethernet") {
                if (nd->parent && of_device_is_compatible(nd, "gmac")
                    && of_device_is_compatible(nd->parent, "uni-north"))
                        pmac_call_feature(PMAC_FTR_GMAC_ENABLE, nd, 0, 0);
        }
}

static void pmac_pci_fixup_cardbus(struct pci_dev *dev)
{
        if (!machine_is(powermac))
                return;
        /*
         * Fix the interrupt routing on the various cardbus bridges
         * used on powerbooks
         */
        if (dev->vendor != PCI_VENDOR_ID_TI)
                return;
        if (dev->device == PCI_DEVICE_ID_TI_1130 ||
            dev->device == PCI_DEVICE_ID_TI_1131) {
                u8 val;
                /* Enable PCI interrupt */
                if (pci_read_config_byte(dev, 0x91, &val) == 0)
                        pci_write_config_byte(dev, 0x91, val | 0x30);
                /* Disable ISA interrupt mode */
                if (pci_read_config_byte(dev, 0x92, &val) == 0)
                        pci_write_config_byte(dev, 0x92, val & ~0x06);
        }
        if (dev->device == PCI_DEVICE_ID_TI_1210 ||
            dev->device == PCI_DEVICE_ID_TI_1211 ||
            dev->device == PCI_DEVICE_ID_TI_1410 ||
            dev->device == PCI_DEVICE_ID_TI_1510) {
                u8 val;
                /* 0x8c == TI122X_IRQMUX, 2 says to route the INTA
                   signal out the MFUNC0 pin */
                if (pci_read_config_byte(dev, 0x8c, &val) == 0)
                        pci_write_config_byte(dev, 0x8c, (val & ~0x0f) | 2);
                /* Disable ISA interrupt mode */
                if (pci_read_config_byte(dev, 0x92, &val) == 0)
                        pci_write_config_byte(dev, 0x92, val & ~0x06);
        }
}

DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_TI, PCI_ANY_ID, pmac_pci_fixup_cardbus);

static void pmac_pci_fixup_pciata(struct pci_dev *dev)
{
       u8 progif = 0;

       /*
        * On PowerMacs, we try to switch any PCI ATA controller to
        * fully native mode
        */
        if (!machine_is(powermac))
                return;

        /* Some controllers don't have the class IDE */
        if (dev->vendor == PCI_VENDOR_ID_PROMISE)
                switch(dev->device) {
                case PCI_DEVICE_ID_PROMISE_20246:
                case PCI_DEVICE_ID_PROMISE_20262:
                case PCI_DEVICE_ID_PROMISE_20263:
                case PCI_DEVICE_ID_PROMISE_20265:
                case PCI_DEVICE_ID_PROMISE_20267:
                case PCI_DEVICE_ID_PROMISE_20268:
                case PCI_DEVICE_ID_PROMISE_20269:
                case PCI_DEVICE_ID_PROMISE_20270:
                case PCI_DEVICE_ID_PROMISE_20271:
                case PCI_DEVICE_ID_PROMISE_20275:
                case PCI_DEVICE_ID_PROMISE_20276:
                case PCI_DEVICE_ID_PROMISE_20277:
                        goto good;
                }
        /* Others, check PCI class */
        if ((dev->class >> 8) != PCI_CLASS_STORAGE_IDE)
                return;
 good:
        pci_read_config_byte(dev, PCI_CLASS_PROG, &progif);
        if ((progif & 5) != 5) {
                printk(KERN_INFO "PCI: %s Forcing PCI IDE into native mode\n",
                       pci_name(dev));
                (void) pci_write_config_byte(dev, PCI_CLASS_PROG, progif|5);
                if (pci_read_config_byte(dev, PCI_CLASS_PROG, &progif) ||
                    (progif & 5) != 5)
                        printk(KERN_ERR "Rewrite of PROGIF failed !\n");
                else {
                        /* Clear IO BARs, they will be reassigned */
                        pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, 0);
                        pci_write_config_dword(dev, PCI_BASE_ADDRESS_1, 0);
                        pci_write_config_dword(dev, PCI_BASE_ADDRESS_2, 0);
                        pci_write_config_dword(dev, PCI_BASE_ADDRESS_3, 0);
                }
        }
}
DECLARE_PCI_FIXUP_EARLY(PCI_ANY_ID, PCI_ANY_ID, pmac_pci_fixup_pciata);
#endif /* CONFIG_PPC32 */

/*
 * Disable second function on K2-SATA, it's broken
 * and disable IO BARs on first one
 */
static void fixup_k2_sata(struct pci_dev* dev)
{
        int i;
        u16 cmd;

        if (PCI_FUNC(dev->devfn) > 0) {
                pci_read_config_word(dev, PCI_COMMAND, &cmd);
                cmd &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
                pci_write_config_word(dev, PCI_COMMAND, cmd);
                for (i = 0; i < 6; i++) {
                        dev->resource[i].start = dev->resource[i].end = 0;
                        dev->resource[i].flags = 0;
                        pci_write_config_dword(dev, PCI_BASE_ADDRESS_0 + 4 * i,
                                               0);
                }
        } else {
                pci_read_config_word(dev, PCI_COMMAND, &cmd);
                cmd &= ~PCI_COMMAND_IO;
                pci_write_config_word(dev, PCI_COMMAND, cmd);
                for (i = 0; i < 5; i++) {
                        dev->resource[i].start = dev->resource[i].end = 0;
                        dev->resource[i].flags = 0;
                        pci_write_config_dword(dev, PCI_BASE_ADDRESS_0 + 4 * i,
                                               0);
                }
        }
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SERVERWORKS, 0x0240, fixup_k2_sata);

/*
 * On U4 (aka CPC945) the PCIe root complex "P2P" bridge resource ranges aren't
 * configured by the firmware. The bridge itself seems to ignore them but it
 * causes problems with Linux which then re-assigns devices below the bridge,
 * thus changing addresses of those devices from what was in the device-tree,
 * which sucks when those are video cards using offb
 *
 * We could just mark it transparent but I prefer fixing up the resources to
 * properly show what's going on here, as I have some doubts about having them
 * badly configured potentially being an issue for DMA.
 *
 * We leave PIO alone, it seems to be fine
 *
 * Oh and there's another funny bug. The OF properties advertize the region
 * 0xf1000000..0xf1ffffff as being forwarded as memory space. But that's
 * actually not true, this region is the memory mapped config space. So we
 * also need to filter it out or we'll map things in the wrong place.
 */
static void fixup_u4_pcie(struct pci_dev* dev)
{
        struct pci_controller *host = pci_bus_to_host(dev->bus);
        struct resource *region = NULL;
        u32 reg;
        int i;

        /* Only do that on PowerMac */
        if (!machine_is(powermac))
                return;

        /* Find the largest MMIO region */
        for (i = 0; i < 3; i++) {
                struct resource *r = &host->mem_resources[i];
                if (!(r->flags & IORESOURCE_MEM))
                        continue;
                /* Skip the 0xf0xxxxxx..f2xxxxxx regions, we know they
                 * are reserved by HW for other things
                 */
                if (r->start >= 0xf0000000 && r->start < 0xf3000000)
                        continue;
                if (!region || resource_size(r) > resource_size(region))
                        region = r;
        }
        /* Nothing found, bail */
        if (!region)
                return;

        /* Print things out */
        printk(KERN_INFO "PCI: Fixup U4 PCIe bridge range: %pR\n", region);

        /* Fixup bridge config space. We know it's a Mac, resource aren't
         * offset so let's just blast them as-is. We also know that they
         * fit in 32 bits
         */
        reg = ((region->start >> 16) & 0xfff0) | (region->end & 0xfff00000);
        pci_write_config_dword(dev, PCI_MEMORY_BASE, reg);
        pci_write_config_dword(dev, PCI_PREF_BASE_UPPER32, 0);
        pci_write_config_dword(dev, PCI_PREF_LIMIT_UPPER32, 0);
        pci_write_config_dword(dev, PCI_PREF_MEMORY_BASE, 0);
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_U4_PCIE, fixup_u4_pcie);

#ifdef CONFIG_PPC64
static int pmac_pci_probe_mode(struct pci_bus *bus)
{
        struct device_node *node = pci_bus_to_OF_node(bus);

        /* We need to use normal PCI probing for the AGP bus,
         * since the device for the AGP bridge isn't in the tree.
         * Same for the PCIe host on U4 and the HT host bridge.
         */
        if (bus->self == NULL && (of_device_is_compatible(node, "u3-agp") ||
                                  of_device_is_compatible(node, "u4-pcie") ||
                                  of_device_is_compatible(node, "u3-ht")))
                return PCI_PROBE_NORMAL;
        return PCI_PROBE_DEVTREE;
}
#endif /* CONFIG_PPC64 */

struct pci_controller_ops pmac_pci_controller_ops = {
#ifdef CONFIG_PPC64
        .probe_mode             = pmac_pci_probe_mode,
#endif
#ifdef CONFIG_PPC32
        .enable_device_hook     = pmac_pci_enable_device_hook,
#endif
};