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 acpi_remove_early_pio();
69
70 status = acpi_pci_probe_root_resources(ci);
71 if (status > 0) {
72 acpi_evaluate_integer(device->handle, "PCIH", NULL, &pci_h);
73 if (pci_h)
74 return status;
75
76 resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
77 if (entry->res->flags & IORESOURCE_MEM) {
78 entry->offset = ci->root->mcfg_addr & GENMASK_ULL(63, 40);
79 entry->res->start |= entry->offset;
80 entry->res->end |= entry->offset;
81 }
82 }
83 return status;
84 }
85
86 resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
87 dev_dbg(&device->dev,
88 "host bridge window %pR (ignored)\n", entry->res);
89 resource_list_destroy_entry(entry);
90 }
91
92 return 0;
93 }
94
95 /*
96 * Create a PCI config space window
97 * - reserve mem region
98 * - alloc struct pci_config_window with space for all mappings
99 * - ioremap the config space
100 */
arch_pci_ecam_create(struct device * dev,struct resource * cfgres,struct resource * busr,const struct pci_ecam_ops * ops)101 static struct pci_config_window *arch_pci_ecam_create(struct device *dev,
102 struct resource *cfgres, struct resource *busr, const struct pci_ecam_ops *ops)
103 {
104 int bsz, bus_range, err;
105 struct resource *conflict;
106 struct pci_config_window *cfg;
107
108 if (busr->start > busr->end)
109 return ERR_PTR(-EINVAL);
110
111 cfg = kzalloc_obj(*cfg);
112 if (!cfg)
113 return ERR_PTR(-ENOMEM);
114
115 cfg->parent = dev;
116 cfg->ops = ops;
117 cfg->busr.start = busr->start;
118 cfg->busr.end = busr->end;
119 cfg->busr.flags = IORESOURCE_BUS;
120 bus_range = resource_size(cfgres) >> ops->bus_shift;
121
122 bsz = 1 << ops->bus_shift;
123
124 cfg->res.start = cfgres->start;
125 cfg->res.end = cfgres->end;
126 cfg->res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
127 cfg->res.name = "PCI ECAM";
128
129 conflict = request_resource_conflict(&iomem_resource, &cfg->res);
130 if (conflict) {
131 err = -EBUSY;
132 dev_err(dev, "can't claim ECAM area %pR: address conflict with %s %pR\n",
133 &cfg->res, conflict->name, conflict);
134 goto err_exit;
135 }
136
137 cfg->win = pci_remap_cfgspace(cfgres->start, bus_range * bsz);
138 if (!cfg->win)
139 goto err_exit_iomap;
140
141 if (ops->init) {
142 err = ops->init(cfg);
143 if (err)
144 goto err_exit;
145 }
146 dev_info(dev, "ECAM at %pR for %pR\n", &cfg->res, &cfg->busr);
147
148 return cfg;
149
150 err_exit_iomap:
151 err = -ENOMEM;
152 dev_err(dev, "ECAM ioremap failed\n");
153 err_exit:
154 pci_ecam_free(cfg);
155 return ERR_PTR(err);
156 }
157
158 /*
159 * Lookup the bus range for the domain in MCFG, and set up config space
160 * mapping.
161 */
162 static struct pci_config_window *
pci_acpi_setup_ecam_mapping(struct acpi_pci_root * root)163 pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root)
164 {
165 int ret, bus_shift;
166 u16 seg = root->segment;
167 struct device *dev = &root->device->dev;
168 struct resource cfgres;
169 struct resource *bus_res = &root->secondary;
170 struct pci_config_window *cfg;
171 const struct pci_ecam_ops *ecam_ops;
172
173 ret = pci_mcfg_lookup(root, &cfgres, &ecam_ops);
174 if (ret < 0) {
175 dev_err(dev, "%04x:%pR ECAM region not found, use default value\n", seg, bus_res);
176 ecam_ops = &loongson_pci_ecam_ops;
177 root->mcfg_addr = mcfg_addr_init(0);
178 }
179
180 bus_shift = ecam_ops->bus_shift ? : 20;
181
182 if (bus_shift == 20)
183 cfg = pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
184 else {
185 cfgres.start = root->mcfg_addr + (bus_res->start << bus_shift);
186 cfgres.end = cfgres.start + (resource_size(bus_res) << bus_shift) - 1;
187 cfgres.end |= BIT(28) + (((PCI_CFG_SPACE_EXP_SIZE - 1) & 0xf00) << 16);
188 cfgres.flags = IORESOURCE_MEM;
189 cfg = arch_pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
190 }
191
192 if (IS_ERR(cfg)) {
193 dev_err(dev, "%04x:%pR error %ld mapping ECAM\n", seg, bus_res, PTR_ERR(cfg));
194 return NULL;
195 }
196
197 return cfg;
198 }
199
pci_acpi_scan_root(struct acpi_pci_root * root)200 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
201 {
202 struct pci_bus *bus;
203 struct pci_root_info *info;
204 struct pci_host_bridge *host;
205 struct acpi_pci_root_ops *root_ops;
206 int domain = root->segment;
207 int busnum = root->secondary.start;
208
209 info = kzalloc_obj(*info);
210 if (!info) {
211 pr_warn("pci_bus %04x:%02x: ignored (out of memory)\n", domain, busnum);
212 return NULL;
213 }
214
215 root_ops = kzalloc_obj(*root_ops);
216 if (!root_ops) {
217 kfree(info);
218 return NULL;
219 }
220
221 info->cfg = pci_acpi_setup_ecam_mapping(root);
222 if (!info->cfg) {
223 kfree(info);
224 kfree(root_ops);
225 return NULL;
226 }
227
228 root_ops->release_info = acpi_release_root_info;
229 root_ops->prepare_resources = acpi_prepare_root_resources;
230 root_ops->pci_ops = (struct pci_ops *)&info->cfg->ops->pci_ops;
231
232 bus = pci_find_bus(domain, busnum);
233 if (bus) {
234 memcpy(bus->sysdata, info->cfg, sizeof(struct pci_config_window));
235 kfree(info);
236 kfree(root_ops);
237 } else {
238 struct pci_bus *child;
239
240 bus = acpi_pci_root_create(root, root_ops,
241 &info->common, info->cfg);
242 if (!bus) {
243 kfree(info);
244 kfree(root_ops);
245 return NULL;
246 }
247
248 /* If we must preserve the resource configuration, claim now */
249 host = pci_find_host_bridge(bus);
250 if (host->preserve_config)
251 pci_bus_claim_resources(bus);
252
253 /*
254 * Assign whatever was left unassigned. If we didn't claim above,
255 * this will reassign everything.
256 */
257 pci_assign_unassigned_root_bus_resources(bus);
258
259 list_for_each_entry(child, &bus->children, node)
260 pcie_bus_configure_settings(child);
261 }
262
263 return bus;
264 }
265