linux/drivers/pci/host-bridge.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Host bridge related code
   4 */
   5
   6#include <linux/kernel.h>
   7#include <linux/pci.h>
   8#include <linux/module.h>
   9
  10#include "pci.h"
  11
  12static struct pci_bus *find_pci_root_bus(struct pci_bus *bus)
  13{
  14        while (bus->parent)
  15                bus = bus->parent;
  16
  17        return bus;
  18}
  19
  20struct pci_host_bridge *pci_find_host_bridge(struct pci_bus *bus)
  21{
  22        struct pci_bus *root_bus = find_pci_root_bus(bus);
  23
  24        return to_pci_host_bridge(root_bus->bridge);
  25}
  26EXPORT_SYMBOL_GPL(pci_find_host_bridge);
  27
  28struct device *pci_get_host_bridge_device(struct pci_dev *dev)
  29{
  30        struct pci_bus *root_bus = find_pci_root_bus(dev->bus);
  31        struct device *bridge = root_bus->bridge;
  32
  33        kobject_get(&bridge->kobj);
  34        return bridge;
  35}
  36
  37void  pci_put_host_bridge_device(struct device *dev)
  38{
  39        kobject_put(&dev->kobj);
  40}
  41
  42void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
  43                                 void (*release_fn)(struct pci_host_bridge *),
  44                                 void *release_data)
  45{
  46        bridge->release_fn = release_fn;
  47        bridge->release_data = release_data;
  48}
  49EXPORT_SYMBOL_GPL(pci_set_host_bridge_release);
  50
  51void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
  52                             struct resource *res)
  53{
  54        struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
  55        struct resource_entry *window;
  56        resource_size_t offset = 0;
  57
  58        resource_list_for_each_entry(window, &bridge->windows) {
  59                if (resource_contains(window->res, res)) {
  60                        offset = window->offset;
  61                        break;
  62                }
  63        }
  64
  65        region->start = res->start - offset;
  66        region->end = res->end - offset;
  67}
  68EXPORT_SYMBOL(pcibios_resource_to_bus);
  69
  70static bool region_contains(struct pci_bus_region *region1,
  71                            struct pci_bus_region *region2)
  72{
  73        return region1->start <= region2->start && region1->end >= region2->end;
  74}
  75
  76void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
  77                             struct pci_bus_region *region)
  78{
  79        struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
  80        struct resource_entry *window;
  81        resource_size_t offset = 0;
  82
  83        resource_list_for_each_entry(window, &bridge->windows) {
  84                struct pci_bus_region bus_region;
  85
  86                if (resource_type(res) != resource_type(window->res))
  87                        continue;
  88
  89                bus_region.start = window->res->start - window->offset;
  90                bus_region.end = window->res->end - window->offset;
  91
  92                if (region_contains(&bus_region, region)) {
  93                        offset = window->offset;
  94                        break;
  95                }
  96        }
  97
  98        res->start = region->start + offset;
  99        res->end = region->end + offset;
 100}
 101EXPORT_SYMBOL(pcibios_bus_to_resource);
 102