LXR linux/drivers/pci/host-bridge.c

   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}
  26
  27struct device *pci_get_host_bridge_device(struct pci_dev *dev)
  28{
  29        struct pci_bus *root_bus = find_pci_root_bus(dev->bus);
  30        struct device *bridge = root_bus->bridge;
  31
  32        kobject_get(&bridge->kobj);
  33        return bridge;
  34}
  35
  36void  pci_put_host_bridge_device(struct device *dev)
  37{
  38        kobject_put(&dev->kobj);
  39}
  40
  41void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
  42                                 void (*release_fn)(struct pci_host_bridge *),
  43                                 void *release_data)
  44{
  45        bridge->release_fn = release_fn;
  46        bridge->release_data = release_data;
  47}
  48EXPORT_SYMBOL_GPL(pci_set_host_bridge_release);
  49
  50void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
  51                             struct resource *res)
  52{
  53        struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
  54        struct resource_entry *window;
  55        resource_size_t offset = 0;
  56
  57        resource_list_for_each_entry(window, &bridge->windows) {
  58                if (resource_contains(window->res, res)) {
  59                        offset = window->offset;
  60                        break;
  61                }
  62        }
  63
  64        region->start = res->start - offset;
  65        region->end = res->end - offset;
  66}
  67EXPORT_SYMBOL(pcibios_resource_to_bus);
  68
  69static bool region_contains(struct pci_bus_region *region1,
  70                            struct pci_bus_region *region2)
  71{
  72        return region1->start <= region2->start && region1->end >= region2->end;
  73}
  74
  75void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
  76                             struct pci_bus_region *region)
  77{
  78        struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
  79        struct resource_entry *window;
  80        resource_size_t offset = 0;
  81
  82        resource_list_for_each_entry(window, &bridge->windows) {
  83                struct pci_bus_region bus_region;
  84
  85                if (resource_type(res) != resource_type(window->res))
  86                        continue;
  87
  88                bus_region.start = window->res->start - window->offset;
  89                bus_region.end = window->res->end - window->offset;
  90
  91                if (region_contains(&bus_region, region)) {
  92                        offset = window->offset;
  93                        break;
  94                }
  95        }
  96
  97        res->start = region->start + offset;
  98        res->end = region->end + offset;
  99}
 100EXPORT_SYMBOL(pcibios_bus_to_resource);
 101