drivers/pci/host-bridge.c

   1 /*
   2  * host bridge related code
   3  */
   4
   5 #include <linux/kernel.h>
   6 #include <linux/init.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 static struct pci_host_bridge *find_pci_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
  27 void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
  28                                  void (*release_fn)(struct pci_host_bridge *),
  29                                  void *release_data)
  30 {
  31         bridge->release_fn = release_fn;
  32         bridge->release_data = release_data;
  33 }
  34
  35 void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
  36                              struct resource *res)
  37 {
  38         struct pci_host_bridge *bridge = find_pci_host_bridge(bus);
  39         struct pci_host_bridge_window *window;
  40         resource_size_t offset = 0;
  41
  42         list_for_each_entry(window, &bridge->windows, list) {
  43                 if (resource_contains(window->res, res)) {
  44                         offset = window->offset;
  45                         break;
  46                 }
  47         }
  48
  49         region->start = res->start - offset;
  50         region->end = res->end - offset;
  51 }
  52 EXPORT_SYMBOL(pcibios_resource_to_bus);
  53
  54 static bool region_contains(struct pci_bus_region *region1,
  55                             struct pci_bus_region *region2)
  56 {
  57         return region1->start <= region2->start && region1->end >= region2->end;
  58 }
  59
  60 void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
  61                              struct pci_bus_region *region)
  62 {
  63         struct pci_host_bridge *bridge = find_pci_host_bridge(bus);
  64         struct pci_host_bridge_window *window;
  65         resource_size_t offset = 0;
  66
  67         list_for_each_entry(window, &bridge->windows, list) {
  68                 struct pci_bus_region bus_region;
  69
  70                 if (resource_type(res) != resource_type(window->res))
  71                         continue;
  72
  73                 bus_region.start = window->res->start - window->offset;
  74                 bus_region.end = window->res->end - window->offset;
  75
  76                 if (region_contains(&bus_region, region)) {
  77                         offset = window->offset;
  78                         break;
  79                 }
  80         }
  81
  82         res->start = region->start + offset;
  83         res->end = region->end + offset;
  84 }
  85 EXPORT_SYMBOL(pcibios_bus_to_resource);