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
  27 struct device *pci_get_host_bridge_device(struct pci_dev *dev)
  28 {
  29         struct pci_bus *root_bus = find_pci_root_bus(dev->bus);
  30         struct device *bridge = root_bus->bridge;
  31
  32         kobject_get(&bridge->kobj);
  33         return bridge;
  34 }
  35
  36 void  pci_put_host_bridge_device(struct device *dev)
  37 {
  38         kobject_put(&dev->kobj);
  39 }
  40
  41 void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
  42                                  void (*release_fn)(struct pci_host_bridge *),
  43                                  void *release_data)
  44 {
  45         bridge->release_fn = release_fn;
  46         bridge->release_data = release_data;
  47 }
  48 EXPORT_SYMBOL_GPL(pci_set_host_bridge_release);
  49
  50 void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
  51                              struct resource *res)
  52 {
  53         struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
  54         struct resource_entry *window;
  55         resource_size_t offset = 0;
  56
  57         resource_list_for_each_entry(window, &bridge->windows) {
  58                 if (resource_contains(window->res, res)) {
  59                         offset = window->offset;
  60                         break;
  61                 }
  62         }
  63
  64         region->start = res->start - offset;
  65         region->end = res->end - offset;
  66 }
  67 EXPORT_SYMBOL(pcibios_resource_to_bus);
  68
  69 static bool region_contains(struct pci_bus_region *region1,
  70                             struct pci_bus_region *region2)
  71 {
  72         return region1->start <= region2->start && region1->end >= region2->end;
  73 }
  74
  75 void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
  76                              struct pci_bus_region *region)
  77 {
  78         struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
  79         struct resource_entry *window;
  80         resource_size_t offset = 0;
  81
  82         resource_list_for_each_entry(window, &bridge->windows) {
  83                 struct pci_bus_region bus_region;
  84
  85                 if (resource_type(res) != resource_type(window->res))
  86                         continue;
  87
  88                 bus_region.start = window->res->start - window->offset;
  89                 bus_region.end = window->res->end - window->offset;
  90
  91                 if (region_contains(&bus_region, region)) {
  92                         offset = window->offset;
  93                         break;
  94                 }
  95         }
  96
  97         res->start = region->start + offset;
  98         res->end = region->end + offset;
  99 }
 100 EXPORT_SYMBOL(pcibios_bus_to_resource);