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}
26EXPORT_SYMBOL_GPL(pci_find_host_bridge);
27
28struct 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
37void  pci_put_host_bridge_device(struct device *dev)
38{
39	kobject_put(&dev->kobj);
40}
41
42void 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}
49EXPORT_SYMBOL_GPL(pci_set_host_bridge_release);
50
51void 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}
68EXPORT_SYMBOL(pcibios_resource_to_bus);
69
70static 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
76void 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}
101EXPORT_SYMBOL(pcibios_bus_to_resource);
102