xref: /linux/drivers/pci/host-bridge.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
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_dev *dev)
13 {
14 	struct pci_bus *bus;
15 
16 	bus = dev->bus;
17 	while (bus->parent)
18 		bus = bus->parent;
19 
20 	return bus;
21 }
22 
23 static struct pci_host_bridge *find_pci_host_bridge(struct pci_dev *dev)
24 {
25 	struct pci_bus *bus = find_pci_root_bus(dev);
26 
27 	return to_pci_host_bridge(bus->bridge);
28 }
29 
30 void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
31 				 void (*release_fn)(struct pci_host_bridge *),
32 				 void *release_data)
33 {
34 	bridge->release_fn = release_fn;
35 	bridge->release_data = release_data;
36 }
37 
38 static bool resource_contains(struct resource *res1, struct resource *res2)
39 {
40 	return res1->start <= res2->start && res1->end >= res2->end;
41 }
42 
43 void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
44 			     struct resource *res)
45 {
46 	struct pci_host_bridge *bridge = find_pci_host_bridge(dev);
47 	struct pci_host_bridge_window *window;
48 	resource_size_t offset = 0;
49 
50 	list_for_each_entry(window, &bridge->windows, list) {
51 		if (resource_type(res) != resource_type(window->res))
52 			continue;
53 
54 		if (resource_contains(window->res, res)) {
55 			offset = window->offset;
56 			break;
57 		}
58 	}
59 
60 	region->start = res->start - offset;
61 	region->end = res->end - offset;
62 }
63 EXPORT_SYMBOL(pcibios_resource_to_bus);
64 
65 static bool region_contains(struct pci_bus_region *region1,
66 			    struct pci_bus_region *region2)
67 {
68 	return region1->start <= region2->start && region1->end >= region2->end;
69 }
70 
71 void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
72 			     struct pci_bus_region *region)
73 {
74 	struct pci_host_bridge *bridge = find_pci_host_bridge(dev);
75 	struct pci_host_bridge_window *window;
76 	resource_size_t offset = 0;
77 
78 	list_for_each_entry(window, &bridge->windows, list) {
79 		struct pci_bus_region bus_region;
80 
81 		if (resource_type(res) != resource_type(window->res))
82 			continue;
83 
84 		bus_region.start = window->res->start - window->offset;
85 		bus_region.end = window->res->end - window->offset;
86 
87 		if (region_contains(&bus_region, region)) {
88 			offset = window->offset;
89 			break;
90 		}
91 	}
92 
93 	res->start = region->start + offset;
94 	res->end = region->end + offset;
95 }
96 EXPORT_SYMBOL(pcibios_bus_to_resource);
97