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 unsigned long long pci_h = 0;
65 struct resource_entry *entry, *tmp;
66 struct acpi_device *device = ci->bridge;
67
68 status = acpi_pci_probe_root_resources(ci);
69 if (status > 0) {
70 acpi_evaluate_integer(device->handle, "PCIH", NULL, &pci_h);
71 if (pci_h)
72 return status;
73
74 resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
75 if (entry->res->flags & IORESOURCE_MEM) {
76 entry->offset = ci->root->mcfg_addr & GENMASK_ULL(63, 40);
77 entry->res->start |= entry->offset;
78 entry->res->end |= entry->offset;
79 }
80 }
81 return status;
82 }
83
84 resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
85 dev_dbg(&device->dev,
86 "host bridge window %pR (ignored)\n", entry->res);
87 resource_list_destroy_entry(entry);
88 }
89
90 return 0;
91 }
92
93 /*
94 * Create a PCI config space window
95 * - reserve mem region
96 * - alloc struct pci_config_window with space for all mappings
97 * - ioremap the config space
98 */
arch_pci_ecam_create(struct device * dev,struct resource * cfgres,struct resource * busr,const struct pci_ecam_ops * ops)99 static struct pci_config_window *arch_pci_ecam_create(struct device *dev,
100 struct resource *cfgres, struct resource *busr, const struct pci_ecam_ops *ops)
101 {
102 int bsz, bus_range, err;
103 struct resource *conflict;
104 struct pci_config_window *cfg;
105
106 if (busr->start > busr->end)
107 return ERR_PTR(-EINVAL);
108
109 cfg = kzalloc_obj(*cfg);
110 if (!cfg)
111 return ERR_PTR(-ENOMEM);
112
113 cfg->parent = dev;
114 cfg->ops = ops;
115 cfg->busr.start = busr->start;
116 cfg->busr.end = busr->end;
117 cfg->busr.flags = IORESOURCE_BUS;
118 bus_range = resource_size(cfgres) >> ops->bus_shift;
119
120 bsz = 1 << ops->bus_shift;
121
122 cfg->res.start = cfgres->start;
123 cfg->res.end = cfgres->end;
124 cfg->res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
125 cfg->res.name = "PCI ECAM";
126
127 conflict = request_resource_conflict(&iomem_resource, &cfg->res);
128 if (conflict) {
129 err = -EBUSY;
130 dev_err(dev, "can't claim ECAM area %pR: address conflict with %s %pR\n",
131 &cfg->res, conflict->name, conflict);
132 goto err_exit;
133 }
134
135 cfg->win = pci_remap_cfgspace(cfgres->start, bus_range * bsz);
136 if (!cfg->win)
137 goto err_exit_iomap;
138
139 if (ops->init) {
140 err = ops->init(cfg);
141 if (err)
142 goto err_exit;
143 }
144 dev_info(dev, "ECAM at %pR for %pR\n", &cfg->res, &cfg->busr);
145
146 return cfg;
147
148 err_exit_iomap:
149 err = -ENOMEM;
150 dev_err(dev, "ECAM ioremap failed\n");
151 err_exit:
152 pci_ecam_free(cfg);
153 return ERR_PTR(err);
154 }
155
156 /*
157 * Lookup the bus range for the domain in MCFG, and set up config space
158 * mapping.
159 */
160 static struct pci_config_window *
pci_acpi_setup_ecam_mapping(struct acpi_pci_root * root)161 pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root)
162 {
163 int ret, bus_shift;
164 u16 seg = root->segment;
165 struct device *dev = &root->device->dev;
166 struct resource cfgres;
167 struct resource *bus_res = &root->secondary;
168 struct pci_config_window *cfg;
169 const struct pci_ecam_ops *ecam_ops;
170
171 ret = pci_mcfg_lookup(root, &cfgres, &ecam_ops);
172 if (ret < 0) {
173 dev_err(dev, "%04x:%pR ECAM region not found, use default value\n", seg, bus_res);
174 ecam_ops = &loongson_pci_ecam_ops;
175 root->mcfg_addr = mcfg_addr_init(0);
176 }
177
178 bus_shift = ecam_ops->bus_shift ? : 20;
179
180 if (bus_shift == 20)
181 cfg = pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
182 else {
183 cfgres.start = root->mcfg_addr + (bus_res->start << bus_shift);
184 cfgres.end = cfgres.start + (resource_size(bus_res) << bus_shift) - 1;
185 cfgres.end |= BIT(28) + (((PCI_CFG_SPACE_EXP_SIZE - 1) & 0xf00) << 16);
186 cfgres.flags = IORESOURCE_MEM;
187 cfg = arch_pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
188 }
189
190 if (IS_ERR(cfg)) {
191 dev_err(dev, "%04x:%pR error %ld mapping ECAM\n", seg, bus_res, PTR_ERR(cfg));
192 return NULL;
193 }
194
195 return cfg;
196 }
197
pci_acpi_scan_root(struct acpi_pci_root * root)198 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
199 {
200 struct pci_bus *bus;
201 struct pci_root_info *info;
202 struct pci_host_bridge *host;
203 struct acpi_pci_root_ops *root_ops;
204 int domain = root->segment;
205 int busnum = root->secondary.start;
206
207 info = kzalloc_obj(*info);
208 if (!info) {
209 pr_warn("pci_bus %04x:%02x: ignored (out of memory)\n", domain, busnum);
210 return NULL;
211 }
212
213 root_ops = kzalloc_obj(*root_ops);
214 if (!root_ops) {
215 kfree(info);
216 return NULL;
217 }
218
219 info->cfg = pci_acpi_setup_ecam_mapping(root);
220 if (!info->cfg) {
221 kfree(info);
222 kfree(root_ops);
223 return NULL;
224 }
225
226 root_ops->release_info = acpi_release_root_info;
227 root_ops->prepare_resources = acpi_prepare_root_resources;
228 root_ops->pci_ops = (struct pci_ops *)&info->cfg->ops->pci_ops;
229
230 bus = pci_find_bus(domain, busnum);
231 if (bus) {
232 memcpy(bus->sysdata, info->cfg, sizeof(struct pci_config_window));
233 kfree(info);
234 kfree(root_ops);
235 } else {
236 struct pci_bus *child;
237
238 bus = acpi_pci_root_create(root, root_ops,
239 &info->common, info->cfg);
240 if (!bus) {
241 kfree(info);
242 kfree(root_ops);
243 return NULL;
244 }
245
246 /* If we must preserve the resource configuration, claim now */
247 host = pci_find_host_bridge(bus);
248 if (host->preserve_config)
249 pci_bus_claim_resources(bus);
250
251 /*
252 * Assign whatever was left unassigned. If we didn't claim above,
253 * this will reassign everything.
254 */
255 pci_assign_unassigned_root_bus_resources(bus);
256
257 list_for_each_entry(child, &bus->children, node)
258 pcie_bus_configure_settings(child);
259 }
260
261 return bus;
262 }
263