drivers/pci/host-bridge.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Host bridge related code
0004  */
0005
0006 #include <linux/kernel.h>
0007 #include <linux/pci.h>
0008 #include <linux/module.h>
0009
0010 #include "pci.h"
0011
0012 static struct pci_bus *find_pci_root_bus(struct pci_bus *bus)
0013 {
0014     while (bus->parent)
0015         bus = bus->parent;
0016
0017     return bus;
0018 }
0019
0020 struct pci_host_bridge *pci_find_host_bridge(struct pci_bus *bus)
0021 {
0022     struct pci_bus *root_bus = find_pci_root_bus(bus);
0023
0024     return to_pci_host_bridge(root_bus->bridge);
0025 }
0026 EXPORT_SYMBOL_GPL(pci_find_host_bridge);
0027
0028 struct device *pci_get_host_bridge_device(struct pci_dev *dev)
0029 {
0030     struct pci_bus *root_bus = find_pci_root_bus(dev->bus);
0031     struct device *bridge = root_bus->bridge;
0032
0033     kobject_get(&bridge->kobj);
0034     return bridge;
0035 }
0036
0037 void  pci_put_host_bridge_device(struct device *dev)
0038 {
0039     kobject_put(&dev->kobj);
0040 }
0041
0042 void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
0043                  void (*release_fn)(struct pci_host_bridge *),
0044                  void *release_data)
0045 {
0046     bridge->release_fn = release_fn;
0047     bridge->release_data = release_data;
0048 }
0049 EXPORT_SYMBOL_GPL(pci_set_host_bridge_release);
0050
0051 void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
0052                  struct resource *res)
0053 {
0054     struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
0055     struct resource_entry *window;
0056     resource_size_t offset = 0;
0057
0058     resource_list_for_each_entry(window, &bridge->windows) {
0059         if (resource_contains(window->res, res)) {
0060             offset = window->offset;
0061             break;
0062         }
0063     }
0064
0065     region->start = res->start - offset;
0066     region->end = res->end - offset;
0067 }
0068 EXPORT_SYMBOL(pcibios_resource_to_bus);
0069
0070 static bool region_contains(struct pci_bus_region *region1,
0071                 struct pci_bus_region *region2)
0072 {
0073     return region1->start <= region2->start && region1->end >= region2->end;
0074 }
0075
0076 void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
0077                  struct pci_bus_region *region)
0078 {
0079     struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
0080     struct resource_entry *window;
0081     resource_size_t offset = 0;
0082
0083     resource_list_for_each_entry(window, &bridge->windows) {
0084         struct pci_bus_region bus_region;
0085
0086         if (resource_type(res) != resource_type(window->res))
0087             continue;
0088
0089         bus_region.start = window->res->start - window->offset;
0090         bus_region.end = window->res->end - window->offset;
0091
0092         if (region_contains(&bus_region, region)) {
0093             offset = window->offset;
0094             break;
0095         }
0096     }
0097
0098     res->start = region->start + offset;
0099     res->end = region->end + offset;
0100 }
0101 EXPORT_SYMBOL(pcibios_bus_to_resource);