xref: /openbmc/linux/arch/arm64/kernel/pci.c (revision 3213486f)
1 /*
2  * Code borrowed from powerpc/kernel/pci-common.c
3  *
4  * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
5  * Copyright (C) 2014 ARM Ltd.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * version 2 as published by the Free Software Foundation.
10  *
11  */
12 
13 #include <linux/acpi.h>
14 #include <linux/init.h>
15 #include <linux/io.h>
16 #include <linux/kernel.h>
17 #include <linux/mm.h>
18 #include <linux/of_pci.h>
19 #include <linux/of_platform.h>
20 #include <linux/pci.h>
21 #include <linux/pci-acpi.h>
22 #include <linux/pci-ecam.h>
23 #include <linux/slab.h>
24 
25 #ifdef CONFIG_ACPI
26 /*
27  * Try to assign the IRQ number when probing a new device
28  */
29 int pcibios_alloc_irq(struct pci_dev *dev)
30 {
31 	if (!acpi_disabled)
32 		acpi_pci_irq_enable(dev);
33 
34 	return 0;
35 }
36 #endif
37 
38 /*
39  * raw_pci_read/write - Platform-specific PCI config space access.
40  */
41 int raw_pci_read(unsigned int domain, unsigned int bus,
42 		  unsigned int devfn, int reg, int len, u32 *val)
43 {
44 	struct pci_bus *b = pci_find_bus(domain, bus);
45 
46 	if (!b)
47 		return PCIBIOS_DEVICE_NOT_FOUND;
48 	return b->ops->read(b, devfn, reg, len, val);
49 }
50 
51 int raw_pci_write(unsigned int domain, unsigned int bus,
52 		unsigned int devfn, int reg, int len, u32 val)
53 {
54 	struct pci_bus *b = pci_find_bus(domain, bus);
55 
56 	if (!b)
57 		return PCIBIOS_DEVICE_NOT_FOUND;
58 	return b->ops->write(b, devfn, reg, len, val);
59 }
60 
61 #ifdef CONFIG_NUMA
62 
63 int pcibus_to_node(struct pci_bus *bus)
64 {
65 	return dev_to_node(&bus->dev);
66 }
67 EXPORT_SYMBOL(pcibus_to_node);
68 
69 #endif
70 
71 #ifdef CONFIG_ACPI
72 
73 struct acpi_pci_generic_root_info {
74 	struct acpi_pci_root_info	common;
75 	struct pci_config_window	*cfg;	/* config space mapping */
76 };
77 
78 int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
79 {
80 	struct pci_config_window *cfg = bus->sysdata;
81 	struct acpi_device *adev = to_acpi_device(cfg->parent);
82 	struct acpi_pci_root *root = acpi_driver_data(adev);
83 
84 	return root->segment;
85 }
86 
87 int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
88 {
89 	if (!acpi_disabled) {
90 		struct pci_config_window *cfg = bridge->bus->sysdata;
91 		struct acpi_device *adev = to_acpi_device(cfg->parent);
92 		struct device *bus_dev = &bridge->bus->dev;
93 
94 		ACPI_COMPANION_SET(&bridge->dev, adev);
95 		set_dev_node(bus_dev, acpi_get_node(acpi_device_handle(adev)));
96 	}
97 
98 	return 0;
99 }
100 
101 static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info *ci)
102 {
103 	struct resource_entry *entry, *tmp;
104 	int status;
105 
106 	status = acpi_pci_probe_root_resources(ci);
107 	resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
108 		if (!(entry->res->flags & IORESOURCE_WINDOW))
109 			resource_list_destroy_entry(entry);
110 	}
111 	return status;
112 }
113 
114 /*
115  * Lookup the bus range for the domain in MCFG, and set up config space
116  * mapping.
117  */
118 static struct pci_config_window *
119 pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root)
120 {
121 	struct device *dev = &root->device->dev;
122 	struct resource *bus_res = &root->secondary;
123 	u16 seg = root->segment;
124 	struct pci_ecam_ops *ecam_ops;
125 	struct resource cfgres;
126 	struct acpi_device *adev;
127 	struct pci_config_window *cfg;
128 	int ret;
129 
130 	ret = pci_mcfg_lookup(root, &cfgres, &ecam_ops);
131 	if (ret) {
132 		dev_err(dev, "%04x:%pR ECAM region not found\n", seg, bus_res);
133 		return NULL;
134 	}
135 
136 	adev = acpi_resource_consumer(&cfgres);
137 	if (adev)
138 		dev_info(dev, "ECAM area %pR reserved by %s\n", &cfgres,
139 			 dev_name(&adev->dev));
140 	else
141 		dev_warn(dev, FW_BUG "ECAM area %pR not reserved in ACPI namespace\n",
142 			 &cfgres);
143 
144 	cfg = pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
145 	if (IS_ERR(cfg)) {
146 		dev_err(dev, "%04x:%pR error %ld mapping ECAM\n", seg, bus_res,
147 			PTR_ERR(cfg));
148 		return NULL;
149 	}
150 
151 	return cfg;
152 }
153 
154 /* release_info: free resources allocated by init_info */
155 static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)
156 {
157 	struct acpi_pci_generic_root_info *ri;
158 
159 	ri = container_of(ci, struct acpi_pci_generic_root_info, common);
160 	pci_ecam_free(ri->cfg);
161 	kfree(ci->ops);
162 	kfree(ri);
163 }
164 
165 /* Interface called from ACPI code to setup PCI host controller */
166 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
167 {
168 	struct acpi_pci_generic_root_info *ri;
169 	struct pci_bus *bus, *child;
170 	struct acpi_pci_root_ops *root_ops;
171 
172 	ri = kzalloc(sizeof(*ri), GFP_KERNEL);
173 	if (!ri)
174 		return NULL;
175 
176 	root_ops = kzalloc(sizeof(*root_ops), GFP_KERNEL);
177 	if (!root_ops) {
178 		kfree(ri);
179 		return NULL;
180 	}
181 
182 	ri->cfg = pci_acpi_setup_ecam_mapping(root);
183 	if (!ri->cfg) {
184 		kfree(ri);
185 		kfree(root_ops);
186 		return NULL;
187 	}
188 
189 	root_ops->release_info = pci_acpi_generic_release_info;
190 	root_ops->prepare_resources = pci_acpi_root_prepare_resources;
191 	root_ops->pci_ops = &ri->cfg->ops->pci_ops;
192 	bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
193 	if (!bus)
194 		return NULL;
195 
196 	pci_bus_size_bridges(bus);
197 	pci_bus_assign_resources(bus);
198 
199 	list_for_each_entry(child, &bus->children, node)
200 		pcie_bus_configure_settings(child);
201 
202 	return bus;
203 }
204 
205 void pcibios_add_bus(struct pci_bus *bus)
206 {
207 	acpi_pci_add_bus(bus);
208 }
209 
210 void pcibios_remove_bus(struct pci_bus *bus)
211 {
212 	acpi_pci_remove_bus(bus);
213 }
214 
215 #endif
216