1 // SPDX-License-Identifier: GPL-2.0-only
3 * Code borrowed from powerpc/kernel/pci-common.c
5 * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
6 * Copyright (C) 2014 ARM Ltd.
9 #include <linux/acpi.h>
10 #include <linux/init.h>
12 #include <linux/kernel.h>
14 #include <linux/of_pci.h>
15 #include <linux/of_platform.h>
16 #include <linux/pci.h>
17 #include <linux/pci-acpi.h>
18 #include <linux/pci-ecam.h>
19 #include <linux/slab.h>
23 * Try to assign the IRQ number when probing a new device
25 int pcibios_alloc_irq(struct pci_dev *dev)
28 acpi_pci_irq_enable(dev);
35 * raw_pci_read/write - Platform-specific PCI config space access.
37 int raw_pci_read(unsigned int domain, unsigned int bus,
38 unsigned int devfn, int reg, int len, u32 *val)
40 struct pci_bus *b = pci_find_bus(domain, bus);
43 return PCIBIOS_DEVICE_NOT_FOUND;
44 return b->ops->read(b, devfn, reg, len, val);
47 int raw_pci_write(unsigned int domain, unsigned int bus,
48 unsigned int devfn, int reg, int len, u32 val)
50 struct pci_bus *b = pci_find_bus(domain, bus);
53 return PCIBIOS_DEVICE_NOT_FOUND;
54 return b->ops->write(b, devfn, reg, len, val);
59 int pcibus_to_node(struct pci_bus *bus)
61 return dev_to_node(&bus->dev);
63 EXPORT_SYMBOL(pcibus_to_node);
69 struct acpi_pci_generic_root_info {
70 struct acpi_pci_root_info common;
71 struct pci_config_window *cfg; /* config space mapping */
74 int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
76 struct pci_config_window *cfg = bus->sysdata;
77 struct acpi_device *adev = to_acpi_device(cfg->parent);
78 struct acpi_pci_root *root = acpi_driver_data(adev);
83 int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
86 struct pci_config_window *cfg = bridge->bus->sysdata;
87 struct acpi_device *adev = to_acpi_device(cfg->parent);
88 struct device *bus_dev = &bridge->bus->dev;
90 ACPI_COMPANION_SET(&bridge->dev, adev);
91 set_dev_node(bus_dev, acpi_get_node(acpi_device_handle(adev)));
97 static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info *ci)
99 struct resource_entry *entry, *tmp;
102 status = acpi_pci_probe_root_resources(ci);
103 resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
104 if (!(entry->res->flags & IORESOURCE_WINDOW))
105 resource_list_destroy_entry(entry);
111 * Lookup the bus range for the domain in MCFG, and set up config space
114 static struct pci_config_window *
115 pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root)
117 struct device *dev = &root->device->dev;
118 struct resource *bus_res = &root->secondary;
119 u16 seg = root->segment;
120 const struct pci_ecam_ops *ecam_ops;
121 struct resource cfgres;
122 struct acpi_device *adev;
123 struct pci_config_window *cfg;
126 ret = pci_mcfg_lookup(root, &cfgres, &ecam_ops);
128 dev_err(dev, "%04x:%pR ECAM region not found\n", seg, bus_res);
132 adev = acpi_resource_consumer(&cfgres);
134 dev_info(dev, "ECAM area %pR reserved by %s\n", &cfgres,
135 dev_name(&adev->dev));
137 dev_warn(dev, FW_BUG "ECAM area %pR not reserved in ACPI namespace\n",
140 cfg = pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
142 dev_err(dev, "%04x:%pR error %ld mapping ECAM\n", seg, bus_res,
150 /* release_info: free resources allocated by init_info */
151 static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)
153 struct acpi_pci_generic_root_info *ri;
155 ri = container_of(ci, struct acpi_pci_generic_root_info, common);
156 pci_ecam_free(ri->cfg);
161 /* Interface called from ACPI code to setup PCI host controller */
162 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
164 struct acpi_pci_generic_root_info *ri;
165 struct pci_bus *bus, *child;
166 struct acpi_pci_root_ops *root_ops;
167 struct pci_host_bridge *host;
169 ri = kzalloc(sizeof(*ri), GFP_KERNEL);
173 root_ops = kzalloc(sizeof(*root_ops), GFP_KERNEL);
179 ri->cfg = pci_acpi_setup_ecam_mapping(root);
186 root_ops->release_info = pci_acpi_generic_release_info;
187 root_ops->prepare_resources = pci_acpi_root_prepare_resources;
188 root_ops->pci_ops = (struct pci_ops *)&ri->cfg->ops->pci_ops;
189 bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
193 /* If we must preserve the resource configuration, claim now */
194 host = pci_find_host_bridge(bus);
195 if (host->preserve_config)
196 pci_bus_claim_resources(bus);
199 * Assign whatever was left unassigned. If we didn't claim above,
200 * this will reassign everything.
202 pci_assign_unassigned_root_bus_resources(bus);
204 list_for_each_entry(child, &bus->children, node)
205 pcie_bus_configure_settings(child);
210 void pcibios_add_bus(struct pci_bus *bus)
212 acpi_pci_add_bus(bus);
215 void pcibios_remove_bus(struct pci_bus *bus)
217 acpi_pci_remove_bus(bus);