/*
 * Common pmac/prep/chrp pci routines. -- Cort
 */

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/capability.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/bootmem.h>
#include <linux/irq.h>
#include <linux/list.h>
#include <linux/of.h>
#include <linux/slab.h>

#include <asm/processor.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/sections.h>
#include <asm/pci-bridge.h>
#include <asm/byteorder.h>
#include <asm/uaccess.h>

#undef DEBUG

unsigned long isa_io_base;
unsigned long pci_dram_offset;
int pcibios_assign_bus_offset = 1;

static u8 *pci_to_OF_bus_map;

/* By default, we don't re-assign bus numbers. We do this only on
 * some pmacs
 */
static int pci_assign_all_buses;

static int pci_bus_count;

/*
 * Functions below are used on OpenFirmware machines.
 */
static void
make_one_node_map(struct device_node *node, u8 pci_bus)
{
        const int *bus_range;
        int len;

        if (pci_bus >= pci_bus_count)
                return;
        bus_range = of_get_property(node, "bus-range", &len);
        if (bus_range == NULL || len < 2 * sizeof(int)) {
                printk(KERN_WARNING "Can't get bus-range for %s, "
                       "assuming it starts at 0\n", node->full_name);
                pci_to_OF_bus_map[pci_bus] = 0;
        } else
                pci_to_OF_bus_map[pci_bus] = bus_range[0];

        for_each_child_of_node(node, node) {
                struct pci_dev *dev;
                const unsigned int *class_code, *reg;

                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;
                reg = of_get_property(node, "reg", NULL);
                if (!reg)
                        continue;
                dev = pci_get_bus_and_slot(pci_bus, ((reg[0] >> 8) & 0xff));
                if (!dev || !dev->subordinate) {
                        pci_dev_put(dev);
                        continue;
                }
                make_one_node_map(node, dev->subordinate->number);
                pci_dev_put(dev);
        }
}

void
pcibios_make_OF_bus_map(void)
{
        int i;
        struct pci_controller *hose, *tmp;
        struct property *map_prop;
        struct device_node *dn;

        pci_to_OF_bus_map = kmalloc(pci_bus_count, GFP_KERNEL);
        if (!pci_to_OF_bus_map) {
                printk(KERN_ERR "Can't allocate OF bus map !\n");
                return;
        }

        /* We fill the bus map with invalid values, that helps
         * debugging.
         */
        for (i = 0; i < pci_bus_count; i++)
                pci_to_OF_bus_map[i] = 0xff;

        /* For each hose, we begin searching bridges */
        list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
                struct device_node *node = hose->dn;

                if (!node)
                        continue;
                make_one_node_map(node, hose->first_busno);
        }
        dn = of_find_node_by_path("/");
        map_prop = of_find_property(dn, "pci-OF-bus-map", NULL);
        if (map_prop) {
                BUG_ON(pci_bus_count > map_prop->length);
                memcpy(map_prop->value, pci_to_OF_bus_map, pci_bus_count);
        }
        of_node_put(dn);
#ifdef DEBUG
        printk(KERN_INFO "PCI->OF bus map:\n");
        for (i = 0; i < pci_bus_count; i++) {
                if (pci_to_OF_bus_map[i] == 0xff)
                        continue;
                printk(KERN_INFO "%d -> %d\n", i, pci_to_OF_bus_map[i]);
        }
#endif
}

typedef int (*pci_OF_scan_iterator)(struct device_node *node, void *data);

static struct device_node *scan_OF_pci_childs(struct device_node *parent,
                                        pci_OF_scan_iterator filter, void *data)
{
        struct device_node *node;
        struct device_node *sub_node;

        for_each_child_of_node(parent, node) {
                const unsigned int *class_code;

                if (filter(node, data)) {
                        of_node_put(node);
                        return node;
                }

                /* For PCI<->PCI bridges or CardBus bridges, we go down
                 * Note: some OFs create a parent node "multifunc-device" as
                 * a fake root for all functions of a multi-function device,
                 * we go down them as well.
                 */
                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)) &&
                        strcmp(node->name, "multifunc-device"))
                        continue;
                sub_node = scan_OF_pci_childs(node, filter, data);
                if (sub_node) {
                        of_node_put(node);
                        return sub_node;
                }
        }
        return NULL;
}

static struct device_node *scan_OF_for_pci_dev(struct device_node *parent,
                                               unsigned int devfn)
{
        struct device_node *np, *cnp;
        const u32 *reg;
        unsigned int psize;

        for_each_child_of_node(parent, np) {
                reg = of_get_property(np, "reg", &psize);
                if (reg && psize >= 4 && ((reg[0] >> 8) & 0xff) == devfn)
                        return np;

                /* Note: some OFs create a parent node "multifunc-device" as
                 * a fake root for all functions of a multi-function device,
                 * we go down them as well. */
                if (!strcmp(np->name, "multifunc-device")) {
                        cnp = scan_OF_for_pci_dev(np, devfn);
                        if (cnp)
                                return cnp;
                }
        }
        return NULL;
}


static struct device_node *scan_OF_for_pci_bus(struct pci_bus *bus)
{
        struct device_node *parent, *np;

        /* Are we a root bus ? */
        if (bus->self == NULL || bus->parent == NULL) {
                struct pci_controller *hose = pci_bus_to_host(bus);
                if (hose == NULL)
                        return NULL;
                return of_node_get(hose->dn);
        }

        /* not a root bus, we need to get our parent */
        parent = scan_OF_for_pci_bus(bus->parent);
        if (parent == NULL)
                return NULL;

        /* now iterate for children for a match */
        np = scan_OF_for_pci_dev(parent, bus->self->devfn);
        of_node_put(parent);

        return np;
}

/*
 * Scans the OF tree for a device node matching a PCI device
 */
struct device_node *
pci_busdev_to_OF_node(struct pci_bus *bus, int devfn)
{
        struct device_node *parent, *np;

        pr_debug("pci_busdev_to_OF_node(%d,0x%x)\n", bus->number, devfn);
        parent = scan_OF_for_pci_bus(bus);
        if (parent == NULL)
                return NULL;
        pr_debug(" parent is %s\n", parent ? parent->full_name : "<NULL>");
        np = scan_OF_for_pci_dev(parent, devfn);
        of_node_put(parent);
        pr_debug(" result is %s\n", np ? np->full_name : "<NULL>");

        /* XXX most callers don't release the returned node
         * mostly because ppc64 doesn't increase the refcount,
         * we need to fix that.
         */
        return np;
}
EXPORT_SYMBOL(pci_busdev_to_OF_node);

struct device_node*
pci_device_to_OF_node(struct pci_dev *dev)
{
        return pci_busdev_to_OF_node(dev->bus, dev->devfn);
}
EXPORT_SYMBOL(pci_device_to_OF_node);

static int
find_OF_pci_device_filter(struct device_node *node, void *data)
{
        return ((void *)node == data);
}

/*
 * Returns the PCI device matching a given OF node
 */
int
pci_device_from_OF_node(struct device_node *node, u8 *bus, u8 *devfn)
{
        const unsigned int *reg;
        struct pci_controller *hose;
        struct pci_dev *dev = NULL;

        /* Make sure it's really a PCI device */
        hose = pci_find_hose_for_OF_device(node);
        if (!hose || !hose->dn)
                return -ENODEV;
        if (!scan_OF_pci_childs(hose->dn,
                        find_OF_pci_device_filter, (void *)node))
                return -ENODEV;
        reg = of_get_property(node, "reg", NULL);
        if (!reg)
                return -ENODEV;
        *bus = (reg[0] >> 16) & 0xff;
        *devfn = ((reg[0] >> 8) & 0xff);

        /* Ok, here we need some tweak. If we have already renumbered
         * all busses, we can't rely on the OF bus number any more.
         * the pci_to_OF_bus_map is not enough as several PCI busses
         * may match the same OF bus number.
         */
        if (!pci_to_OF_bus_map)
                return 0;

        for_each_pci_dev(dev)
                if (pci_to_OF_bus_map[dev->bus->number] == *bus &&
                                dev->devfn == *devfn) {
                        *bus = dev->bus->number;
                        pci_dev_put(dev);
                        return 0;
                }

        return -ENODEV;
}
EXPORT_SYMBOL(pci_device_from_OF_node);

/* We create the "pci-OF-bus-map" property now so it appears in the
 * /proc device tree
 */
void __init
pci_create_OF_bus_map(void)
{
        struct property *of_prop;
        struct device_node *dn;

        of_prop = (struct property *) alloc_bootmem(sizeof(struct property) + \
                                                                         256);
        if (!of_prop)
                return;
        dn = of_find_node_by_path("/");
        if (dn) {
                memset(of_prop, -1, sizeof(struct property) + 256);
                of_prop->name = "pci-OF-bus-map";
                of_prop->length = 256;
                of_prop->value = &of_prop[1];
                prom_add_property(dn, of_prop);
                of_node_put(dn);
        }
}

static void __devinit pcibios_scan_phb(struct pci_controller *hose)
{
        struct pci_bus *bus;
        struct device_node *node = hose->dn;
        unsigned long io_offset;
        struct resource *res = &hose->io_resource;

        pr_debug("PCI: Scanning PHB %s\n",
                 node ? node->full_name : "<NO NAME>");

        /* Create an empty bus for the toplevel */
        bus = pci_create_bus(hose->parent, hose->first_busno, hose->ops, hose);
        if (bus == NULL) {
                printk(KERN_ERR "Failed to create bus for PCI domain %04x\n",
                       hose->global_number);
                return;
        }
        bus->secondary = hose->first_busno;
        hose->bus = bus;

        /* Fixup IO space offset */
        io_offset = (unsigned long)hose->io_base_virt - isa_io_base;
        res->start = (res->start + io_offset) & 0xffffffffu;
        res->end = (res->end + io_offset) & 0xffffffffu;

        /* Wire up PHB bus resources */
        pcibios_setup_phb_resources(hose);

        /* Scan children */
        hose->last_busno = bus->subordinate = pci_scan_child_bus(bus);
}

static int __init pcibios_init(void)
{
        struct pci_controller *hose, *tmp;
        int next_busno = 0;

        printk(KERN_INFO "PCI: Probing PCI hardware\n");

        if (pci_flags & PCI_REASSIGN_ALL_BUS) {
                printk(KERN_INFO "setting pci_asign_all_busses\n");
                pci_assign_all_buses = 1;
        }

        /* Scan all of the recorded PCI controllers.  */
        list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
                if (pci_assign_all_buses)
                        hose->first_busno = next_busno;
                hose->last_busno = 0xff;
                pcibios_scan_phb(hose);
                printk(KERN_INFO "calling pci_bus_add_devices()\n");
                pci_bus_add_devices(hose->bus);
                if (pci_assign_all_buses || next_busno <= hose->last_busno)
                        next_busno = hose->last_busno + \
                                        pcibios_assign_bus_offset;
        }
        pci_bus_count = next_busno;

        /* OpenFirmware based machines need a map of OF bus
         * numbers vs. kernel bus numbers since we may have to
         * remap them.
         */
        if (pci_assign_all_buses)
                pcibios_make_OF_bus_map();

        /* Call common code to handle resource allocation */
        pcibios_resource_survey();

        return 0;
}

subsys_initcall(pcibios_init);

static struct pci_controller*
pci_bus_to_hose(int bus)
{
        struct pci_controller *hose, *tmp;

        list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
                if (bus >= hose->first_busno && bus <= hose->last_busno)
                        return hose;
        return NULL;
}

/* Provide information on locations of various I/O regions in physical
 * memory.  Do this on a per-card basis so that we choose the right
 * root bridge.
 * Note that the returned IO or memory base is a physical address
 */

long sys_pciconfig_iobase(long which, unsigned long bus, unsigned long devfn)
{
        struct pci_controller *hose;
        long result = -EOPNOTSUPP;

        hose = pci_bus_to_hose(bus);
        if (!hose)
                return -ENODEV;

        switch (which) {
        case IOBASE_BRIDGE_NUMBER:
                return (long)hose->first_busno;
        case IOBASE_MEMORY:
                return (long)hose->pci_mem_offset;
        case IOBASE_IO:
                return (long)hose->io_base_phys;
        case IOBASE_ISA_IO:
                return (long)isa_io_base;
        case IOBASE_ISA_MEM:
                return (long)isa_mem_base;
        }

        return result;
}