host-bridge.c

  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}
 36EXPORT_SYMBOL_GPL(pci_get_host_bridge_device);
 37
 38void  pci_put_host_bridge_device(struct device *dev)
 39{
 40	kobject_put(&dev->kobj);
 41}
 42
 43void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
 44				 void (*release_fn)(struct pci_host_bridge *),
 45				 void *release_data)
 46{
 47	bridge->release_fn = release_fn;
 48	bridge->release_data = release_data;
 49}
 50EXPORT_SYMBOL_GPL(pci_set_host_bridge_release);
 51
 52void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
 53			     struct resource *res)
 54{
 55	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
 56	struct resource_entry *window;
 57	resource_size_t offset = 0;
 58
 59	resource_list_for_each_entry(window, &bridge->windows) {
 60		if (resource_contains(window->res, res)) {
 61			offset = window->offset;
 62			break;
 63		}
 64	}
 65
 66	region->start = res->start - offset;
 67	region->end = res->end - offset;
 68}
 69EXPORT_SYMBOL(pcibios_resource_to_bus);
 70
 71static bool region_contains(struct pci_bus_region *region1,
 72			    struct pci_bus_region *region2)
 73{
 74	return region1->start <= region2->start && region1->end >= region2->end;
 75}
 76
 77void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
 78			     struct pci_bus_region *region)
 79{
 80	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
 81	struct resource_entry *window;
 82	resource_size_t offset = 0;
 83
 84	resource_list_for_each_entry(window, &bridge->windows) {
 85		struct pci_bus_region bus_region;
 86
 87		if (resource_type(res) != resource_type(window->res))
 88			continue;
 89
 90		bus_region.start = window->res->start - window->offset;
 91		bus_region.end = window->res->end - window->offset;
 92
 93		if (region_contains(&bus_region, region)) {
 94			offset = window->offset;
 95			break;
 96		}
 97	}
 98
 99	res->start = region->start + offset;
100	res->end = region->end + offset;
101}
102EXPORT_SYMBOL(pcibios_bus_to_resource);