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, busnr: 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, busnr: 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(dev: &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(d: 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(dev: bus_dev, node: acpi_get_node(handle: 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(info: 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: &cfgres, ecam_ops: &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(res: &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: &cfgres, busr: bus_res, ops: ecam_ops); |
154 | if (IS_ERR(ptr: 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(cfg: ri->cfg); |
170 | kfree(objp: ci->ops); |
171 | kfree(objp: 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(size: sizeof(*ri), GFP_KERNEL); |
183 | if (!ri) |
184 | return NULL; |
185 | |
186 | root_ops = kzalloc(size: sizeof(*root_ops), GFP_KERNEL); |
187 | if (!root_ops) { |
188 | kfree(objp: ri); |
189 | return NULL; |
190 | } |
191 | |
192 | ri->cfg = pci_acpi_setup_ecam_mapping(root); |
193 | if (!ri->cfg) { |
194 | kfree(objp: ri); |
195 | kfree(objp: 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, ops: root_ops, info: &ri->common, sd: 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(bus: 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 | |