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(bus: dev->bus);
31 struct device *bridge = root_bus->bridge;
32
33 kobject_get(kobj: &bridge->kobj);
34 return bridge;
35}
36
37void pci_put_host_bridge_device(struct device *dev)
38{
39 kobject_put(kobj: &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(r1: window->res, r2: 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(res: 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(region1: &bus_region, region2: 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