drivers/pci/host-bridge.c

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