xref: /openbmc/linux/drivers/pci/host-bridge.c (revision 2c684d89)
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 
48 void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
49 			     struct resource *res)
50 {
51 	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
52 	struct resource_entry *window;
53 	resource_size_t offset = 0;
54 
55 	resource_list_for_each_entry(window, &bridge->windows) {
56 		if (resource_contains(window->res, res)) {
57 			offset = window->offset;
58 			break;
59 		}
60 	}
61 
62 	region->start = res->start - offset;
63 	region->end = res->end - offset;
64 }
65 EXPORT_SYMBOL(pcibios_resource_to_bus);
66 
67 static bool region_contains(struct pci_bus_region *region1,
68 			    struct pci_bus_region *region2)
69 {
70 	return region1->start <= region2->start && region1->end >= region2->end;
71 }
72 
73 void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
74 			     struct pci_bus_region *region)
75 {
76 	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
77 	struct resource_entry *window;
78 	resource_size_t offset = 0;
79 
80 	resource_list_for_each_entry(window, &bridge->windows) {
81 		struct pci_bus_region bus_region;
82 
83 		if (resource_type(res) != resource_type(window->res))
84 			continue;
85 
86 		bus_region.start = window->res->start - window->offset;
87 		bus_region.end = window->res->end - window->offset;
88 
89 		if (region_contains(&bus_region, region)) {
90 			offset = window->offset;
91 			break;
92 		}
93 	}
94 
95 	res->start = region->start + offset;
96 	res->end = region->end + offset;
97 }
98 EXPORT_SYMBOL(pcibios_bus_to_resource);
99