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
12static 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
20struct 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
27struct device *pci_get_host_bridge_device(struct pci_dev *dev)
28{
29	struct pci_bus *root_bus = find_pci_root_bus(dev->bus);
30	struct device *bridge = root_bus->bridge;
31
32	kobject_get(&bridge->kobj);
33	return bridge;
34}
35
36void  pci_put_host_bridge_device(struct device *dev)
37{
38	kobject_put(&dev->kobj);
39}
40
41void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
42				 void (*release_fn)(struct pci_host_bridge *),
43				 void *release_data)
44{
45	bridge->release_fn = release_fn;
46	bridge->release_data = release_data;
47}
48EXPORT_SYMBOL_GPL(pci_set_host_bridge_release);
49
50void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
51			     struct resource *res)
52{
53	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
54	struct resource_entry *window;
55	resource_size_t offset = 0;
56
57	resource_list_for_each_entry(window, &bridge->windows) {
58		if (resource_contains(window->res, res)) {
59			offset = window->offset;
60			break;
61		}
62	}
63
64	region->start = res->start - offset;
65	region->end = res->end - offset;
66}
67EXPORT_SYMBOL(pcibios_resource_to_bus);
68
69static bool region_contains(struct pci_bus_region *region1,
70			    struct pci_bus_region *region2)
71{
72	return region1->start <= region2->start && region1->end >= region2->end;
73}
74
75void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
76			     struct pci_bus_region *region)
77{
78	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
79	struct resource_entry *window;
80	resource_size_t offset = 0;
81
82	resource_list_for_each_entry(window, &bridge->windows) {
83		struct pci_bus_region bus_region;
84
85		if (resource_type(res) != resource_type(window->res))
86			continue;
87
88		bus_region.start = window->res->start - window->offset;
89		bus_region.end = window->res->end - window->offset;
90
91		if (region_contains(&bus_region, region)) {
92			offset = window->offset;
93			break;
94		}
95	}
96
97	res->start = region->start + offset;
98	res->end = region->end + offset;
99}
100EXPORT_SYMBOL(pcibios_bus_to_resource);
101