host-bridge.c

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/*
 * host bridge related code
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/module.h>

#include "pci.h"

static struct pci_bus *find_pci_root_bus(struct pci_dev *dev)
{
    struct pci_bus *bus;

    bus = dev->bus;
    while (bus->parent)
        bus = bus->parent;

    return bus;
}

static struct pci_host_bridge *find_pci_host_bridge(struct pci_dev *dev)
{
    struct pci_bus *bus = find_pci_root_bus(dev);

    return to_pci_host_bridge(bus->bridge);
}

void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
                 void (*release_fn)(struct pci_host_bridge *),
                 void *release_data)
{
    bridge->release_fn = release_fn;
    bridge->release_data = release_data;
}

static bool resource_contains(struct resource *res1, struct resource *res2)
{
    return res1->start <= res2->start && res1->end >= res2->end;
}

void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
                 struct resource *res)
{
    struct pci_host_bridge *bridge = find_pci_host_bridge(dev);
    struct pci_host_bridge_window *window;
    resource_size_t offset = 0;

    list_for_each_entry(window, &bridge->windows, list) {
        if (resource_type(res) != resource_type(window->res))
            continue;

        if (resource_contains(window->res, res)) {
            offset = window->offset;
            break;
        }
    }

    region->start = res->start - offset;
    region->end = res->end - offset;
}
EXPORT_SYMBOL(pcibios_resource_to_bus);

static bool region_contains(struct pci_bus_region *region1,
                struct pci_bus_region *region2)
{
    return region1->start <= region2->start && region1->end >= region2->end;
}

void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
                 struct pci_bus_region *region)
{
    struct pci_host_bridge *bridge = find_pci_host_bridge(dev);
    struct pci_host_bridge_window *window;
    resource_size_t offset = 0;

    list_for_each_entry(window, &bridge->windows, list) {
        struct pci_bus_region bus_region;

        if (resource_type(res) != resource_type(window->res))
            continue;

        bus_region.start = window->res->start - window->offset;
        bus_region.end = window->res->end - window->offset;

        if (region_contains(&bus_region, region)) {
            offset = window->offset;
            break;
        }
    }

    res->start = region->start + offset;
    res->end = region->end + offset;
}
EXPORT_SYMBOL(pcibios_bus_to_resource);