1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Code borrowed from powerpc/kernel/pci-common.c
4 *
5 * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
6 * Copyright (C) 2014 ARM Ltd.
7 */
8
9#include <linux/acpi.h>
10#include <linux/init.h>
11#include <linux/io.h>
12#include <linux/kernel.h>
13#include <linux/mm.h>
14#include <linux/pci.h>
15#include <linux/pci-acpi.h>
16#include <linux/pci-ecam.h>
17#include <linux/slab.h>
18
19#ifdef CONFIG_ACPI
20/*
21 * Try to assign the IRQ number when probing a new device
22 */
23int pcibios_alloc_irq(struct pci_dev *dev)
24{
25	if (!acpi_disabled)
26		acpi_pci_irq_enable(dev);
27
28	return 0;
29}
30#endif
31
32/*
33 * raw_pci_read/write - Platform-specific PCI config space access.
34 */
35int raw_pci_read(unsigned int domain, unsigned int bus,
36		  unsigned int devfn, int reg, int len, u32 *val)
37{
38	struct pci_bus *b = pci_find_bus(domain, bus);
39
40	if (!b)
41		return PCIBIOS_DEVICE_NOT_FOUND;
42	return b->ops->read(b, devfn, reg, len, val);
43}
44
45int raw_pci_write(unsigned int domain, unsigned int bus,
46		unsigned int devfn, int reg, int len, u32 val)
47{
48	struct pci_bus *b = pci_find_bus(domain, bus);
49
50	if (!b)
51		return PCIBIOS_DEVICE_NOT_FOUND;
52	return b->ops->write(b, devfn, reg, len, val);
53}
54
55#ifdef CONFIG_NUMA
56
57int pcibus_to_node(struct pci_bus *bus)
58{
59	return dev_to_node(&bus->dev);
60}
61EXPORT_SYMBOL(pcibus_to_node);
62
63#endif
64
65#ifdef CONFIG_ACPI
66
67struct acpi_pci_generic_root_info {
68	struct acpi_pci_root_info	common;
69	struct pci_config_window	*cfg;	/* config space mapping */
70};
71
72int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
73{
74	struct pci_config_window *cfg = bus->sysdata;
75	struct acpi_device *adev = to_acpi_device(cfg->parent);
76	struct acpi_pci_root *root = acpi_driver_data(adev);
77
78	return root->segment;
79}
80
81int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
82{
83	struct pci_config_window *cfg;
84	struct acpi_device *adev;
85	struct device *bus_dev;
86
87	if (acpi_disabled)
88		return 0;
89
90	cfg = bridge->bus->sysdata;
91
92	/*
93	 * On Hyper-V there is no corresponding ACPI device for a root bridge,
94	 * therefore ->parent is set as NULL by the driver. And set 'adev' as
95	 * NULL in this case because there is no proper ACPI device.
96	 */
97	if (!cfg->parent)
98		adev = NULL;
99	else
100		adev = to_acpi_device(cfg->parent);
101
102	bus_dev = &bridge->bus->dev;
103
104	ACPI_COMPANION_SET(&bridge->dev, adev);
105	set_dev_node(bus_dev, acpi_get_node(acpi_device_handle(adev)));
106
107	return 0;
108}
109
110static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info *ci)
111{
112	struct resource_entry *entry, *tmp;
113	int status;
114
115	status = acpi_pci_probe_root_resources(ci);
116	resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
117		if (!(entry->res->flags & IORESOURCE_WINDOW))
118			resource_list_destroy_entry(entry);
119	}
120	return status;
121}
122
123/*
124 * Lookup the bus range for the domain in MCFG, and set up config space
125 * mapping.
126 */
127static struct pci_config_window *
128pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root)
129{
130	struct device *dev = &root->device->dev;
131	struct resource *bus_res = &root->secondary;
132	u16 seg = root->segment;
133	const struct pci_ecam_ops *ecam_ops;
134	struct resource cfgres;
135	struct acpi_device *adev;
136	struct pci_config_window *cfg;
137	int ret;
138
139	ret = pci_mcfg_lookup(root, &cfgres, &ecam_ops);
140	if (ret) {
141		dev_err(dev, "%04x:%pR ECAM region not found\n", seg, bus_res);
142		return NULL;
143	}
144
145	adev = acpi_resource_consumer(&cfgres);
146	if (adev)
147		dev_info(dev, "ECAM area %pR reserved by %s\n", &cfgres,
148			 dev_name(&adev->dev));
149	else
150		dev_warn(dev, FW_BUG "ECAM area %pR not reserved in ACPI namespace\n",
151			 &cfgres);
152
153	cfg = pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
154	if (IS_ERR(cfg)) {
155		dev_err(dev, "%04x:%pR error %ld mapping ECAM\n", seg, bus_res,
156			PTR_ERR(cfg));
157		return NULL;
158	}
159
160	return cfg;
161}
162
163/* release_info: free resources allocated by init_info */
164static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)
165{
166	struct acpi_pci_generic_root_info *ri;
167
168	ri = container_of(ci, struct acpi_pci_generic_root_info, common);
169	pci_ecam_free(ri->cfg);
170	kfree(ci->ops);
171	kfree(ri);
172}
173
174/* Interface called from ACPI code to setup PCI host controller */
175struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
176{
177	struct acpi_pci_generic_root_info *ri;
178	struct pci_bus *bus, *child;
179	struct acpi_pci_root_ops *root_ops;
180	struct pci_host_bridge *host;
181
182	ri = kzalloc(sizeof(*ri), GFP_KERNEL);
183	if (!ri)
184		return NULL;
185
186	root_ops = kzalloc(sizeof(*root_ops), GFP_KERNEL);
187	if (!root_ops) {
188		kfree(ri);
189		return NULL;
190	}
191
192	ri->cfg = pci_acpi_setup_ecam_mapping(root);
193	if (!ri->cfg) {
194		kfree(ri);
195		kfree(root_ops);
196		return NULL;
197	}
198
199	root_ops->release_info = pci_acpi_generic_release_info;
200	root_ops->prepare_resources = pci_acpi_root_prepare_resources;
201	root_ops->pci_ops = (struct pci_ops *)&ri->cfg->ops->pci_ops;
202	bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
203	if (!bus)
204		return NULL;
205
206	/* If we must preserve the resource configuration, claim now */
207	host = pci_find_host_bridge(bus);
208	if (host->preserve_config)
209		pci_bus_claim_resources(bus);
210
211	/*
212	 * Assign whatever was left unassigned. If we didn't claim above,
213	 * this will reassign everything.
214	 */
215	pci_assign_unassigned_root_bus_resources(bus);
216
217	list_for_each_entry(child, &bus->children, node)
218		pcie_bus_configure_settings(child);
219
220	return bus;
221}
222
223void pcibios_add_bus(struct pci_bus *bus)
224{
225	acpi_pci_add_bus(bus);
226}
227
228void pcibios_remove_bus(struct pci_bus *bus)
229{
230	acpi_pci_remove_bus(bus);
231}
232
233#endif
234