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