xref: /linux/drivers/pci/host-bridge.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
1 /*
2  * host bridge related code
3  */
4 
5 #include <linux/kernel.h>
6 #include <linux/pci.h>
7 #include <linux/module.h>
8 
9 #include "pci.h"
10 
11 static struct pci_bus *find_pci_root_bus(struct pci_bus *bus)
12 {
13 	while (bus->parent)
14 		bus = bus->parent;
15 
16 	return bus;
17 }
18 
19 struct pci_host_bridge *pci_find_host_bridge(struct pci_bus *bus)
20 {
21 	struct pci_bus *root_bus = find_pci_root_bus(bus);
22 
23 	return to_pci_host_bridge(root_bus->bridge);
24 }
25 
26 struct device *pci_get_host_bridge_device(struct pci_dev *dev)
27 {
28 	struct pci_bus *root_bus = find_pci_root_bus(dev->bus);
29 	struct device *bridge = root_bus->bridge;
30 
31 	kobject_get(&bridge->kobj);
32 	return bridge;
33 }
34 
35 void  pci_put_host_bridge_device(struct device *dev)
36 {
37 	kobject_put(&dev->kobj);
38 }
39 
40 void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
41 				 void (*release_fn)(struct pci_host_bridge *),
42 				 void *release_data)
43 {
44 	bridge->release_fn = release_fn;
45 	bridge->release_data = release_data;
46 }
47 EXPORT_SYMBOL_GPL(pci_set_host_bridge_release);
48 
49 void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
50 			     struct resource *res)
51 {
52 	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
53 	struct resource_entry *window;
54 	resource_size_t offset = 0;
55 
56 	resource_list_for_each_entry(window, &bridge->windows) {
57 		if (resource_contains(window->res, res)) {
58 			offset = window->offset;
59 			break;
60 		}
61 	}
62 
63 	region->start = res->start - offset;
64 	region->end = res->end - offset;
65 }
66 EXPORT_SYMBOL(pcibios_resource_to_bus);
67 
68 static bool region_contains(struct pci_bus_region *region1,
69 			    struct pci_bus_region *region2)
70 {
71 	return region1->start <= region2->start && region1->end >= region2->end;
72 }
73 
74 void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
75 			     struct pci_bus_region *region)
76 {
77 	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
78 	struct resource_entry *window;
79 	resource_size_t offset = 0;
80 
81 	resource_list_for_each_entry(window, &bridge->windows) {
82 		struct pci_bus_region bus_region;
83 
84 		if (resource_type(res) != resource_type(window->res))
85 			continue;
86 
87 		bus_region.start = window->res->start - window->offset;
88 		bus_region.end = window->res->end - window->offset;
89 
90 		if (region_contains(&bus_region, region)) {
91 			offset = window->offset;
92 			break;
93 		}
94 	}
95 
96 	res->start = region->start + offset;
97 	res->end = region->end + offset;
98 }
99 EXPORT_SYMBOL(pcibios_bus_to_resource);
100