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 LIST_HEAD(pci_host_bridges);
  13
  14 void add_to_pci_host_bridges(struct pci_host_bridge *bridge)
  15 {
  16         list_add_tail(&bridge->list, &pci_host_bridges);
  17 }
  18
  19 static struct pci_host_bridge *pci_host_bridge(struct pci_dev *dev)
  20 {
  21         struct pci_bus *bus;
  22         struct pci_host_bridge *bridge;
  23
  24         bus = dev->bus;
  25         while (bus->parent)
  26                 bus = bus->parent;
  27
  28         list_for_each_entry(bridge, &pci_host_bridges, list) {
  29                 if (bridge->bus == bus)
  30                         return bridge;
  31         }
  32
  33         return NULL;
  34 }
  35
  36 static bool resource_contains(struct resource *res1, struct resource *res2)
  37 {
  38         return res1->start <= res2->start && res1->end >= res2->end;
  39 }
  40
  41 void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
  42                              struct resource *res)
  43 {
  44         struct pci_host_bridge *bridge = pci_host_bridge(dev);
  45         struct pci_host_bridge_window *window;
  46         resource_size_t offset = 0;
  47
  48         list_for_each_entry(window, &bridge->windows, list) {
  49                 if (resource_type(res) != resource_type(window->res))
  50                         continue;
  51
  52                 if (resource_contains(window->res, res)) {
  53                         offset = window->offset;
  54                         break;
  55                 }
  56         }
  57
  58         region->start = res->start - offset;
  59         region->end = res->end - offset;
  60 }
  61 EXPORT_SYMBOL(pcibios_resource_to_bus);
  62
  63 static bool region_contains(struct pci_bus_region *region1,
  64                             struct pci_bus_region *region2)
  65 {
  66         return region1->start <= region2->start && region1->end >= region2->end;
  67 }
  68
  69 void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
  70                              struct pci_bus_region *region)
  71 {
  72         struct pci_host_bridge *bridge = pci_host_bridge(dev);
  73         struct pci_host_bridge_window *window;
  74         struct pci_bus_region bus_region;
  75         resource_size_t offset = 0;
  76
  77         list_for_each_entry(window, &bridge->windows, list) {
  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);