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 */
23 int 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 */
35 int 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
45 int 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
57 int pcibus_to_node(struct pci_bus *bus)
58 {
59 return dev_to_node(&bus->dev);
60 }
61 EXPORT_SYMBOL(pcibus_to_node);
62
63 #endif
64
65 #ifdef CONFIG_ACPI
66
67 struct acpi_pci_generic_root_info {
68 struct acpi_pci_root_info common;
69 struct pci_config_window *cfg; /* config space mapping */
70 };
71
72 int 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
81 int 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
110 static 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 */
127 static struct pci_config_window *
128 pci_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 */
164 static 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 */
175 struct 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
223 void pcibios_add_bus(struct pci_bus *bus)
224 {
225 acpi_pci_add_bus(bus);
226 }
227
228 void pcibios_remove_bus(struct pci_bus *bus)
229 {
230 acpi_pci_remove_bus(bus);
231 }
232
233 #endif
234
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