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
pci_get_host_bridge_device(struct pci_dev * dev)27 struct 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
pci_put_host_bridge_device(struct device * dev)36 void pci_put_host_bridge_device(struct device *dev)
37 {
38 kobject_put(&dev->kobj);
39 }
40
pci_set_host_bridge_release(struct pci_host_bridge * bridge,void (* release_fn)(struct pci_host_bridge *),void * release_data)41 void 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 }
48 EXPORT_SYMBOL_GPL(pci_set_host_bridge_release);
49
pcibios_resource_to_bus(struct pci_bus * bus,struct pci_bus_region * region,struct resource * res)50 void 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 }
67 EXPORT_SYMBOL(pcibios_resource_to_bus);
68
region_contains(struct pci_bus_region * region1,struct pci_bus_region * region2)69 static 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
pcibios_bus_to_resource(struct pci_bus * bus,struct resource * res,struct pci_bus_region * region)75 void 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 }
100 EXPORT_SYMBOL(pcibios_bus_to_resource);
101