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
  12 static 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
  20 struct 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 EXPORT_SYMBOL_GPL(pci_find_host_bridge);
  27
  28 struct 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
  37 void  pci_put_host_bridge_device(struct device *dev)
  38 {
  39         kobject_put(&dev->kobj);
  40 }
  41
  42 void 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 }
  49 EXPORT_SYMBOL_GPL(pci_set_host_bridge_release);
  50
  51 void 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 }
  68 EXPORT_SYMBOL(pcibios_resource_to_bus);
  69
  70 static 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
  76 void 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 }
 101 EXPORT_SYMBOL(pcibios_bus_to_resource);