1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
6 #include <linux/acpi.h>
7 #include <linux/init.h>
9 #include <linux/slab.h>
10 #include <linux/pci-acpi.h>
11 #include <linux/pci-ecam.h>
15 #include <asm/loongson.h>
17 struct pci_root_info {
18 struct acpi_pci_root_info common;
19 struct pci_config_window *cfg;
22 void pcibios_add_bus(struct pci_bus *bus)
24 acpi_pci_add_bus(bus);
27 int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
29 struct pci_config_window *cfg = bridge->bus->sysdata;
30 struct acpi_device *adev = to_acpi_device(cfg->parent);
31 struct device *bus_dev = &bridge->bus->dev;
33 ACPI_COMPANION_SET(&bridge->dev, adev);
34 set_dev_node(bus_dev, pa_to_nid(cfg->res.start));
39 int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
41 struct pci_config_window *cfg = bus->sysdata;
42 struct acpi_device *adev = to_acpi_device(cfg->parent);
43 struct acpi_pci_root *root = acpi_driver_data(adev);
48 static void acpi_release_root_info(struct acpi_pci_root_info *ci)
50 struct pci_root_info *info;
52 info = container_of(ci, struct pci_root_info, common);
53 pci_ecam_free(info->cfg);
58 static int acpi_prepare_root_resources(struct acpi_pci_root_info *ci)
61 struct resource_entry *entry, *tmp;
62 struct acpi_device *device = ci->bridge;
64 status = acpi_pci_probe_root_resources(ci);
66 resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
67 if (entry->res->flags & IORESOURCE_MEM) {
68 entry->offset = ci->root->mcfg_addr & GENMASK_ULL(63, 40);
69 entry->res->start |= entry->offset;
70 entry->res->end |= entry->offset;
76 resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
78 "host bridge window %pR (ignored)\n", entry->res);
79 resource_list_destroy_entry(entry);
86 * Lookup the bus range for the domain in MCFG, and set up config space
89 static struct pci_config_window *
90 pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root)
93 u16 seg = root->segment;
94 struct device *dev = &root->device->dev;
95 struct resource cfgres;
96 struct resource *bus_res = &root->secondary;
97 struct pci_config_window *cfg;
98 const struct pci_ecam_ops *ecam_ops;
100 ret = pci_mcfg_lookup(root, &cfgres, &ecam_ops);
102 dev_err(dev, "%04x:%pR ECAM region not found, use default value\n", seg, bus_res);
103 ecam_ops = &loongson_pci_ecam_ops;
104 root->mcfg_addr = mcfg_addr_init(0);
107 bus_shift = ecam_ops->bus_shift ? : 20;
109 cfgres.start = root->mcfg_addr + (bus_res->start << bus_shift);
110 cfgres.end = cfgres.start + (resource_size(bus_res) << bus_shift) - 1;
111 cfgres.flags = IORESOURCE_MEM;
113 cfg = pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
115 dev_err(dev, "%04x:%pR error %ld mapping ECAM\n", seg, bus_res, PTR_ERR(cfg));
122 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
125 struct pci_root_info *info;
126 struct acpi_pci_root_ops *root_ops;
127 int domain = root->segment;
128 int busnum = root->secondary.start;
130 info = kzalloc(sizeof(*info), GFP_KERNEL);
132 pr_warn("pci_bus %04x:%02x: ignored (out of memory)\n", domain, busnum);
136 root_ops = kzalloc(sizeof(*root_ops), GFP_KERNEL);
142 info->cfg = pci_acpi_setup_ecam_mapping(root);
149 root_ops->release_info = acpi_release_root_info;
150 root_ops->prepare_resources = acpi_prepare_root_resources;
151 root_ops->pci_ops = (struct pci_ops *)&info->cfg->ops->pci_ops;
153 bus = pci_find_bus(domain, busnum);
155 memcpy(bus->sysdata, info->cfg, sizeof(struct pci_config_window));
158 struct pci_bus *child;
160 bus = acpi_pci_root_create(root, root_ops,
161 &info->common, info->cfg);
168 pci_bus_size_bridges(bus);
169 pci_bus_assign_resources(bus);
170 list_for_each_entry(child, &bus->children, node)
171 pcie_bus_configure_settings(child);