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  
find_pci_root_bus(struct pci_bus * bus)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  
pci_find_host_bridge(struct pci_bus * bus)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  EXPORT_SYMBOL_GPL(pci_find_host_bridge);
27  
pci_get_host_bridge_device(struct pci_dev * dev)28  struct device *pci_get_host_bridge_device(struct pci_dev *dev)
29  {
30  	struct pci_bus *root_bus = find_pci_root_bus(dev->bus);
31  	struct device *bridge = root_bus->bridge;
32  
33  	kobject_get(&bridge->kobj);
34  	return bridge;
35  }
36  
pci_put_host_bridge_device(struct device * dev)37  void  pci_put_host_bridge_device(struct device *dev)
38  {
39  	kobject_put(&dev->kobj);
40  }
41  
pci_set_host_bridge_release(struct pci_host_bridge * bridge,void (* release_fn)(struct pci_host_bridge *),void * release_data)42  void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
43  				 void (*release_fn)(struct pci_host_bridge *),
44  				 void *release_data)
45  {
46  	bridge->release_fn = release_fn;
47  	bridge->release_data = release_data;
48  }
49  EXPORT_SYMBOL_GPL(pci_set_host_bridge_release);
50  
pcibios_resource_to_bus(struct pci_bus * bus,struct pci_bus_region * region,struct resource * res)51  void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
52  			     struct resource *res)
53  {
54  	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
55  	struct resource_entry *window;
56  	resource_size_t offset = 0;
57  
58  	resource_list_for_each_entry(window, &bridge->windows) {
59  		if (resource_contains(window->res, res)) {
60  			offset = window->offset;
61  			break;
62  		}
63  	}
64  
65  	region->start = res->start - offset;
66  	region->end = res->end - offset;
67  }
68  EXPORT_SYMBOL(pcibios_resource_to_bus);
69  
region_contains(struct pci_bus_region * region1,struct pci_bus_region * region2)70  static bool region_contains(struct pci_bus_region *region1,
71  			    struct pci_bus_region *region2)
72  {
73  	return region1->start <= region2->start && region1->end >= region2->end;
74  }
75  
pcibios_bus_to_resource(struct pci_bus * bus,struct resource * res,struct pci_bus_region * region)76  void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
77  			     struct pci_bus_region *region)
78  {
79  	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
80  	struct resource_entry *window;
81  	resource_size_t offset = 0;
82  
83  	resource_list_for_each_entry(window, &bridge->windows) {
84  		struct pci_bus_region bus_region;
85  
86  		if (resource_type(res) != resource_type(window->res))
87  			continue;
88  
89  		bus_region.start = window->res->start - window->offset;
90  		bus_region.end = window->res->end - window->offset;
91  
92  		if (region_contains(&bus_region, region)) {
93  			offset = window->offset;
94  			break;
95  		}
96  	}
97  
98  	res->start = region->start + offset;
99  	res->end = region->end + offset;
100  }
101  EXPORT_SYMBOL(pcibios_bus_to_resource);
102