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 static bool resource_contains(struct resource *res1, struct resource *res2)
  36 {
  37         return res1->start <= res2->start && res1->end >= res2->end;
  38 }
  39
  40 void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
  41                              struct resource *res)
  42 {
  43         struct pci_host_bridge *bridge = find_pci_host_bridge(bus);
  44         struct pci_host_bridge_window *window;
  45         resource_size_t offset = 0;
  46
  47         list_for_each_entry(window, &bridge->windows, list) {
  48                 if (resource_type(res) != resource_type(window->res))
  49                         continue;
  50
  51                 if (resource_contains(window->res, res)) {
  52                         offset = window->offset;
  53                         break;
  54                 }
  55         }
  56
  57         region->start = res->start - offset;
  58         region->end = res->end - offset;
  59 }
  60 EXPORT_SYMBOL(pcibios_resource_to_bus);
  61
  62 static bool region_contains(struct pci_bus_region *region1,
  63                             struct pci_bus_region *region2)
  64 {
  65         return region1->start <= region2->start && region1->end >= region2->end;
  66 }
  67
  68 void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
  69                              struct pci_bus_region *region)
  70 {
  71         struct pci_host_bridge *bridge = find_pci_host_bridge(bus);
  72         struct pci_host_bridge_window *window;
  73         resource_size_t offset = 0;
  74
  75         list_for_each_entry(window, &bridge->windows, list) {
  76                 struct pci_bus_region bus_region;
  77
  78                 if (resource_type(res) != resource_type(window->res))
  79                         continue;
  80
  81                 bus_region.start = window->res->start - window->offset;
  82                 bus_region.end = window->res->end - window->offset;
  83
  84                 if (region_contains(&bus_region, region)) {
  85                         offset = window->offset;
  86                         break;
  87                 }
  88         }
  89
  90         res->start = region->start + offset;
  91         res->end = region->end + offset;
  92 }
  93 EXPORT_SYMBOL(pcibios_bus_to_resource);