1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
4 */
5 #include <linux/pci.h>
6 #include <linux/acpi.h>
7 #include <linux/init.h>
8 #include <linux/irq.h>
9 #include <linux/slab.h>
10 #include <linux/pci-acpi.h>
11 #include <linux/pci-ecam.h>
12
13 #include <asm/pci.h>
14 #include <asm/numa.h>
15 #include <asm/loongson.h>
16
17 struct pci_root_info {
18 struct acpi_pci_root_info common;
19 struct pci_config_window *cfg;
20 };
21
pcibios_add_bus(struct pci_bus * bus)22 void pcibios_add_bus(struct pci_bus *bus)
23 {
24 acpi_pci_add_bus(bus);
25 }
26
pcibios_root_bridge_prepare(struct pci_host_bridge * bridge)27 int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
28 {
29 struct acpi_device *adev = NULL;
30 struct device *bus_dev = &bridge->bus->dev;
31 struct pci_config_window *cfg = bridge->bus->sysdata;
32
33 if (!acpi_disabled)
34 adev = to_acpi_device(cfg->parent);
35
36 ACPI_COMPANION_SET(&bridge->dev, adev);
37 set_dev_node(bus_dev, pa_to_nid(cfg->res.start));
38
39 return 0;
40 }
41
acpi_pci_bus_find_domain_nr(struct pci_bus * bus)42 int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
43 {
44 struct pci_config_window *cfg = bus->sysdata;
45 struct acpi_device *adev = to_acpi_device(cfg->parent);
46 struct acpi_pci_root *root = acpi_driver_data(adev);
47
48 return root->segment;
49 }
50
acpi_release_root_info(struct acpi_pci_root_info * ci)51 static void acpi_release_root_info(struct acpi_pci_root_info *ci)
52 {
53 struct pci_root_info *info;
54
55 info = container_of(ci, struct pci_root_info, common);
56 pci_ecam_free(info->cfg);
57 kfree(ci->ops);
58 kfree(info);
59 }
60
acpi_prepare_root_resources(struct acpi_pci_root_info * ci)61 static int acpi_prepare_root_resources(struct acpi_pci_root_info *ci)
62 {
63 int status;
64 struct resource_entry *entry, *tmp;
65 struct acpi_device *device = ci->bridge;
66
67 status = acpi_pci_probe_root_resources(ci);
68 if (status > 0) {
69 resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
70 if (entry->res->flags & IORESOURCE_MEM) {
71 entry->offset = ci->root->mcfg_addr & GENMASK_ULL(63, 40);
72 entry->res->start |= entry->offset;
73 entry->res->end |= entry->offset;
74 }
75 }
76 return status;
77 }
78
79 resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
80 dev_dbg(&device->dev,
81 "host bridge window %pR (ignored)\n", entry->res);
82 resource_list_destroy_entry(entry);
83 }
84
85 return 0;
86 }
87
88 /*
89 * Create a PCI config space window
90 * - reserve mem region
91 * - alloc struct pci_config_window with space for all mappings
92 * - ioremap the config space
93 */
arch_pci_ecam_create(struct device * dev,struct resource * cfgres,struct resource * busr,const struct pci_ecam_ops * ops)94 static struct pci_config_window *arch_pci_ecam_create(struct device *dev,
95 struct resource *cfgres, struct resource *busr, const struct pci_ecam_ops *ops)
96 {
97 int bsz, bus_range, err;
98 struct resource *conflict;
99 struct pci_config_window *cfg;
100
101 if (busr->start > busr->end)
102 return ERR_PTR(-EINVAL);
103
104 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
105 if (!cfg)
106 return ERR_PTR(-ENOMEM);
107
108 cfg->parent = dev;
109 cfg->ops = ops;
110 cfg->busr.start = busr->start;
111 cfg->busr.end = busr->end;
112 cfg->busr.flags = IORESOURCE_BUS;
113 bus_range = resource_size(cfgres) >> ops->bus_shift;
114
115 bsz = 1 << ops->bus_shift;
116
117 cfg->res.start = cfgres->start;
118 cfg->res.end = cfgres->end;
119 cfg->res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
120 cfg->res.name = "PCI ECAM";
121
122 conflict = request_resource_conflict(&iomem_resource, &cfg->res);
123 if (conflict) {
124 err = -EBUSY;
125 dev_err(dev, "can't claim ECAM area %pR: address conflict with %s %pR\n",
126 &cfg->res, conflict->name, conflict);
127 goto err_exit;
128 }
129
130 cfg->win = pci_remap_cfgspace(cfgres->start, bus_range * bsz);
131 if (!cfg->win)
132 goto err_exit_iomap;
133
134 if (ops->init) {
135 err = ops->init(cfg);
136 if (err)
137 goto err_exit;
138 }
139 dev_info(dev, "ECAM at %pR for %pR\n", &cfg->res, &cfg->busr);
140
141 return cfg;
142
143 err_exit_iomap:
144 err = -ENOMEM;
145 dev_err(dev, "ECAM ioremap failed\n");
146 err_exit:
147 pci_ecam_free(cfg);
148 return ERR_PTR(err);
149 }
150
151 /*
152 * Lookup the bus range for the domain in MCFG, and set up config space
153 * mapping.
154 */
155 static struct pci_config_window *
pci_acpi_setup_ecam_mapping(struct acpi_pci_root * root)156 pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root)
157 {
158 int ret, bus_shift;
159 u16 seg = root->segment;
160 struct device *dev = &root->device->dev;
161 struct resource cfgres;
162 struct resource *bus_res = &root->secondary;
163 struct pci_config_window *cfg;
164 const struct pci_ecam_ops *ecam_ops;
165
166 ret = pci_mcfg_lookup(root, &cfgres, &ecam_ops);
167 if (ret < 0) {
168 dev_err(dev, "%04x:%pR ECAM region not found, use default value\n", seg, bus_res);
169 ecam_ops = &loongson_pci_ecam_ops;
170 root->mcfg_addr = mcfg_addr_init(0);
171 }
172
173 bus_shift = ecam_ops->bus_shift ? : 20;
174
175 if (bus_shift == 20)
176 cfg = pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
177 else {
178 cfgres.start = root->mcfg_addr + (bus_res->start << bus_shift);
179 cfgres.end = cfgres.start + (resource_size(bus_res) << bus_shift) - 1;
180 cfgres.end |= BIT(28) + (((PCI_CFG_SPACE_EXP_SIZE - 1) & 0xf00) << 16);
181 cfgres.flags = IORESOURCE_MEM;
182 cfg = arch_pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
183 }
184
185 if (IS_ERR(cfg)) {
186 dev_err(dev, "%04x:%pR error %ld mapping ECAM\n", seg, bus_res, PTR_ERR(cfg));
187 return NULL;
188 }
189
190 return cfg;
191 }
192
pci_acpi_scan_root(struct acpi_pci_root * root)193 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
194 {
195 struct pci_bus *bus;
196 struct pci_root_info *info;
197 struct acpi_pci_root_ops *root_ops;
198 int domain = root->segment;
199 int busnum = root->secondary.start;
200
201 info = kzalloc(sizeof(*info), GFP_KERNEL);
202 if (!info) {
203 pr_warn("pci_bus %04x:%02x: ignored (out of memory)\n", domain, busnum);
204 return NULL;
205 }
206
207 root_ops = kzalloc(sizeof(*root_ops), GFP_KERNEL);
208 if (!root_ops) {
209 kfree(info);
210 return NULL;
211 }
212
213 info->cfg = pci_acpi_setup_ecam_mapping(root);
214 if (!info->cfg) {
215 kfree(info);
216 kfree(root_ops);
217 return NULL;
218 }
219
220 root_ops->release_info = acpi_release_root_info;
221 root_ops->prepare_resources = acpi_prepare_root_resources;
222 root_ops->pci_ops = (struct pci_ops *)&info->cfg->ops->pci_ops;
223
224 bus = pci_find_bus(domain, busnum);
225 if (bus) {
226 memcpy(bus->sysdata, info->cfg, sizeof(struct pci_config_window));
227 kfree(info);
228 } else {
229 struct pci_bus *child;
230
231 bus = acpi_pci_root_create(root, root_ops,
232 &info->common, info->cfg);
233 if (!bus) {
234 kfree(info);
235 kfree(root_ops);
236 return NULL;
237 }
238
239 pci_bus_size_bridges(bus);
240 pci_bus_assign_resources(bus);
241 list_for_each_entry(child, &bus->children, node)
242 pcie_bus_configure_settings(child);
243 }
244
245 return bus;
246 }
247