/*
 *      drivers/pci/bus.c
 *
 * From setup-res.c, by:
 *      Dave Rusling (david.rusling@reo.mts.dec.com)
 *      David Mosberger (davidm@cs.arizona.edu)
 *      David Miller (davem@redhat.com)
 *      Ivan Kokshaysky (ink@jurassic.park.msu.ru)
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/slab.h>

#include "pci.h"

void pci_add_resource_offset(struct list_head *resources, struct resource *res,
                             resource_size_t offset)
{
        struct pci_host_bridge_window *window;

        window = kzalloc(sizeof(struct pci_host_bridge_window), GFP_KERNEL);
        if (!window) {
                printk(KERN_ERR "PCI: can't add host bridge window %pR\n", res);
                return;
        }

        window->res = res;
        window->offset = offset;
        list_add_tail(&window->list, resources);
}
EXPORT_SYMBOL(pci_add_resource_offset);

void pci_add_resource(struct list_head *resources, struct resource *res)
{
        pci_add_resource_offset(resources, res, 0);
}
EXPORT_SYMBOL(pci_add_resource);

void pci_free_resource_list(struct list_head *resources)
{
        struct pci_host_bridge_window *window, *tmp;

        list_for_each_entry_safe(window, tmp, resources, list) {
                list_del(&window->list);
                kfree(window);
        }
}
EXPORT_SYMBOL(pci_free_resource_list);

void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
                          unsigned int flags)
{
        struct pci_bus_resource *bus_res;

        bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
        if (!bus_res) {
                dev_err(&bus->dev, "can't add %pR resource\n", res);
                return;
        }

        bus_res->res = res;
        bus_res->flags = flags;
        list_add_tail(&bus_res->list, &bus->resources);
}

struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
{
        struct pci_bus_resource *bus_res;

        if (n < PCI_BRIDGE_RESOURCE_NUM)
                return bus->resource[n];

        n -= PCI_BRIDGE_RESOURCE_NUM;
        list_for_each_entry(bus_res, &bus->resources, list) {
                if (n-- == 0)
                        return bus_res->res;
        }
        return NULL;
}
EXPORT_SYMBOL_GPL(pci_bus_resource_n);

void pci_bus_remove_resources(struct pci_bus *bus)
{
        int i;
        struct pci_bus_resource *bus_res, *tmp;

        for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
                bus->resource[i] = NULL;

        list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
                list_del(&bus_res->list);
                kfree(bus_res);
        }
}

/**
 * pci_bus_alloc_resource - allocate a resource from a parent bus
 * @bus: PCI bus
 * @res: resource to allocate
 * @size: size of resource to allocate
 * @align: alignment of resource to allocate
 * @min: minimum /proc/iomem address to allocate
 * @type_mask: IORESOURCE_* type flags
 * @alignf: resource alignment function
 * @alignf_data: data argument for resource alignment function
 *
 * Given the PCI bus a device resides on, the size, minimum address,
 * alignment and type, try to find an acceptable resource allocation
 * for a specific device resource.
 */
int
pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
                resource_size_t size, resource_size_t align,
                resource_size_t min, unsigned int type_mask,
                resource_size_t (*alignf)(void *,
                                          const struct resource *,
                                          resource_size_t,
                                          resource_size_t),
                void *alignf_data)
{
        int i, ret = -ENOMEM;
        struct resource *r;
        resource_size_t max = -1;

        type_mask |= IORESOURCE_IO | IORESOURCE_MEM;

        /* don't allocate too high if the pref mem doesn't support 64bit*/
        if (!(res->flags & IORESOURCE_MEM_64))
                max = PCIBIOS_MAX_MEM_32;

        pci_bus_for_each_resource(bus, r, i) {
                if (!r)
                        continue;

                /* type_mask must match */
                if ((res->flags ^ r->flags) & type_mask)
                        continue;

                /* We cannot allocate a non-prefetching resource
                   from a pre-fetching area */
                if ((r->flags & IORESOURCE_PREFETCH) &&
                    !(res->flags & IORESOURCE_PREFETCH))
                        continue;

                /* Ok, try it out.. */
                ret = allocate_resource(r, res, size,
                                        r->start ? : min,
                                        max, align,
                                        alignf, alignf_data);
                if (ret == 0)
                        break;
        }
        return ret;
}

void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }

/**
 * pci_bus_add_device - start driver for a single device
 * @dev: device to add
 *
 * This adds add sysfs entries and start device drivers
 */
int pci_bus_add_device(struct pci_dev *dev)
{
        int retval;

        /*
         * Can not put in pci_device_add yet because resources
         * are not assigned yet for some devices.
         */
        pci_fixup_device(pci_fixup_final, dev);
        pci_create_sysfs_dev_files(dev);

        dev->match_driver = true;
        retval = device_attach(&dev->dev);
        WARN_ON(retval < 0);

        dev->is_added = 1;

        return 0;
}

/**
 * pci_bus_add_devices - start driver for PCI devices
 * @bus: bus to check for new devices
 *
 * Start driver for PCI devices and add some sysfs entries.
 */
void pci_bus_add_devices(const struct pci_bus *bus)
{
        struct pci_dev *dev;
        struct pci_bus *child;
        int retval;

        list_for_each_entry(dev, &bus->devices, bus_list) {
                /* Skip already-added devices */
                if (dev->is_added)
                        continue;
                retval = pci_bus_add_device(dev);
                if (retval)
                        dev_err(&dev->dev, "Error adding device (%d)\n",
                                retval);
        }

        list_for_each_entry(dev, &bus->devices, bus_list) {
                BUG_ON(!dev->is_added);
                child = dev->subordinate;
                if (child)
                        pci_bus_add_devices(child);
        }
}

void pci_enable_bridges(struct pci_bus *bus)
{
        struct pci_dev *dev;
        int retval;

        list_for_each_entry(dev, &bus->devices, bus_list) {
                if (dev->subordinate) {
                        if (!pci_is_enabled(dev)) {
                                retval = pci_enable_device(dev);
                                if (retval)
                                        dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval);
                                pci_set_master(dev);
                        }
                        pci_enable_bridges(dev->subordinate);
                }
        }
}

/** pci_walk_bus - walk devices on/under bus, calling callback.
 *  @top      bus whose devices should be walked
 *  @cb       callback to be called for each device found
 *  @userdata arbitrary pointer to be passed to callback.
 *
 *  Walk the given bus, including any bridged devices
 *  on buses under this bus.  Call the provided callback
 *  on each device found.
 *
 *  We check the return of @cb each time. If it returns anything
 *  other than 0, we break out.
 *
 */
void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
                  void *userdata)
{
        struct pci_dev *dev;
        struct pci_bus *bus;
        struct list_head *next;
        int retval;

        bus = top;
        down_read(&pci_bus_sem);
        next = top->devices.next;
        for (;;) {
                if (next == &bus->devices) {
                        /* end of this bus, go up or finish */
                        if (bus == top)
                                break;
                        next = bus->self->bus_list.next;
                        bus = bus->self->bus;
                        continue;
                }
                dev = list_entry(next, struct pci_dev, bus_list);
                if (dev->subordinate) {
                        /* this is a pci-pci bridge, do its devices next */
                        next = dev->subordinate->devices.next;
                        bus = dev->subordinate;
                } else
                        next = dev->bus_list.next;

                retval = cb(dev, userdata);
                if (retval)
                        break;
        }
        up_read(&pci_bus_sem);
}
EXPORT_SYMBOL_GPL(pci_walk_bus);

struct pci_bus *pci_bus_get(struct pci_bus *bus)
{
        if (bus)
                get_device(&bus->dev);
        return bus;
}
EXPORT_SYMBOL(pci_bus_get);

void pci_bus_put(struct pci_bus *bus)
{
        if (bus)
                put_device(&bus->dev);
}
EXPORT_SYMBOL(pci_bus_put);

EXPORT_SYMBOL(pci_bus_alloc_resource);
EXPORT_SYMBOL_GPL(pci_bus_add_device);
EXPORT_SYMBOL(pci_bus_add_devices);
EXPORT_SYMBOL(pci_enable_bridges);