1 /*
2 * Simple, generic PCI host controller driver targetting firmware-initialised
3 * systems and virtual machines (e.g. the PCI emulation provided by kvmtool).
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 *
17 * Copyright (C) 2014 ARM Limited
18 *
19 * Author: Will Deacon <will.deacon@arm.com>
20 */
21
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/of_address.h>
25 #include <linux/of_pci.h>
26 #include <linux/platform_device.h>
27
28 struct gen_pci_cfg_bus_ops {
29 u32 bus_shift;
30 struct pci_ops ops;
31 };
32
33 struct gen_pci_cfg_windows {
34 struct resource res;
35 struct resource *bus_range;
36 void __iomem **win;
37
38 struct gen_pci_cfg_bus_ops *ops;
39 };
40
41 /*
42 * ARM pcibios functions expect the ARM struct pci_sys_data as the PCI
43 * sysdata. Add pci_sys_data as the first element in struct gen_pci so
44 * that when we use a gen_pci pointer as sysdata, it is also a pointer to
45 * a struct pci_sys_data.
46 */
47 struct gen_pci {
48 #ifdef CONFIG_ARM
49 struct pci_sys_data sys;
50 #endif
51 struct pci_host_bridge host;
52 struct gen_pci_cfg_windows cfg;
53 struct list_head resources;
54 };
55
gen_pci_map_cfg_bus_cam(struct pci_bus * bus,unsigned int devfn,int where)56 static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
57 unsigned int devfn,
58 int where)
59 {
60 struct gen_pci *pci = bus->sysdata;
61 resource_size_t idx = bus->number - pci->cfg.bus_range->start;
62
63 return pci->cfg.win[idx] + ((devfn << 8) | where);
64 }
65
66 static struct gen_pci_cfg_bus_ops gen_pci_cfg_cam_bus_ops = {
67 .bus_shift = 16,
68 .ops = {
69 .map_bus = gen_pci_map_cfg_bus_cam,
70 .read = pci_generic_config_read,
71 .write = pci_generic_config_write,
72 }
73 };
74
gen_pci_map_cfg_bus_ecam(struct pci_bus * bus,unsigned int devfn,int where)75 static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
76 unsigned int devfn,
77 int where)
78 {
79 struct gen_pci *pci = bus->sysdata;
80 resource_size_t idx = bus->number - pci->cfg.bus_range->start;
81
82 return pci->cfg.win[idx] + ((devfn << 12) | where);
83 }
84
85 static struct gen_pci_cfg_bus_ops gen_pci_cfg_ecam_bus_ops = {
86 .bus_shift = 20,
87 .ops = {
88 .map_bus = gen_pci_map_cfg_bus_ecam,
89 .read = pci_generic_config_read,
90 .write = pci_generic_config_write,
91 }
92 };
93
94 static const struct of_device_id gen_pci_of_match[] = {
95 { .compatible = "pci-host-cam-generic",
96 .data = &gen_pci_cfg_cam_bus_ops },
97
98 { .compatible = "pci-host-ecam-generic",
99 .data = &gen_pci_cfg_ecam_bus_ops },
100
101 { },
102 };
103 MODULE_DEVICE_TABLE(of, gen_pci_of_match);
104
gen_pci_release_of_pci_ranges(struct gen_pci * pci)105 static void gen_pci_release_of_pci_ranges(struct gen_pci *pci)
106 {
107 pci_free_resource_list(&pci->resources);
108 }
109
gen_pci_parse_request_of_pci_ranges(struct gen_pci * pci)110 static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
111 {
112 int err, res_valid = 0;
113 struct device *dev = pci->host.dev.parent;
114 struct device_node *np = dev->of_node;
115 resource_size_t iobase;
116 struct resource_entry *win;
117
118 err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pci->resources,
119 &iobase);
120 if (err)
121 return err;
122
123 resource_list_for_each_entry(win, &pci->resources) {
124 struct resource *parent, *res = win->res;
125
126 switch (resource_type(res)) {
127 case IORESOURCE_IO:
128 parent = &ioport_resource;
129 err = pci_remap_iospace(res, iobase);
130 if (err) {
131 dev_warn(dev, "error %d: failed to map resource %pR\n",
132 err, res);
133 continue;
134 }
135 break;
136 case IORESOURCE_MEM:
137 parent = &iomem_resource;
138 res_valid |= !(res->flags & IORESOURCE_PREFETCH);
139 break;
140 case IORESOURCE_BUS:
141 pci->cfg.bus_range = res;
142 default:
143 continue;
144 }
145
146 err = devm_request_resource(dev, parent, res);
147 if (err)
148 goto out_release_res;
149 }
150
151 if (!res_valid) {
152 dev_err(dev, "non-prefetchable memory resource required\n");
153 err = -EINVAL;
154 goto out_release_res;
155 }
156
157 return 0;
158
159 out_release_res:
160 gen_pci_release_of_pci_ranges(pci);
161 return err;
162 }
163
gen_pci_parse_map_cfg_windows(struct gen_pci * pci)164 static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
165 {
166 int err;
167 u8 bus_max;
168 resource_size_t busn;
169 struct resource *bus_range;
170 struct device *dev = pci->host.dev.parent;
171 struct device_node *np = dev->of_node;
172 u32 sz = 1 << pci->cfg.ops->bus_shift;
173
174 err = of_address_to_resource(np, 0, &pci->cfg.res);
175 if (err) {
176 dev_err(dev, "missing \"reg\" property\n");
177 return err;
178 }
179
180 /* Limit the bus-range to fit within reg */
181 bus_max = pci->cfg.bus_range->start +
182 (resource_size(&pci->cfg.res) >> pci->cfg.ops->bus_shift) - 1;
183 pci->cfg.bus_range->end = min_t(resource_size_t,
184 pci->cfg.bus_range->end, bus_max);
185
186 pci->cfg.win = devm_kcalloc(dev, resource_size(pci->cfg.bus_range),
187 sizeof(*pci->cfg.win), GFP_KERNEL);
188 if (!pci->cfg.win)
189 return -ENOMEM;
190
191 /* Map our Configuration Space windows */
192 if (!devm_request_mem_region(dev, pci->cfg.res.start,
193 resource_size(&pci->cfg.res),
194 "Configuration Space"))
195 return -ENOMEM;
196
197 bus_range = pci->cfg.bus_range;
198 for (busn = bus_range->start; busn <= bus_range->end; ++busn) {
199 u32 idx = busn - bus_range->start;
200
201 pci->cfg.win[idx] = devm_ioremap(dev,
202 pci->cfg.res.start + idx * sz,
203 sz);
204 if (!pci->cfg.win[idx])
205 return -ENOMEM;
206 }
207
208 return 0;
209 }
210
gen_pci_probe(struct platform_device * pdev)211 static int gen_pci_probe(struct platform_device *pdev)
212 {
213 int err;
214 const char *type;
215 const struct of_device_id *of_id;
216 struct device *dev = &pdev->dev;
217 struct device_node *np = dev->of_node;
218 struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
219 struct pci_bus *bus, *child;
220
221 if (!pci)
222 return -ENOMEM;
223
224 type = of_get_property(np, "device_type", NULL);
225 if (!type || strcmp(type, "pci")) {
226 dev_err(dev, "invalid \"device_type\" %s\n", type);
227 return -EINVAL;
228 }
229
230 of_pci_check_probe_only();
231
232 of_id = of_match_node(gen_pci_of_match, np);
233 pci->cfg.ops = (struct gen_pci_cfg_bus_ops *)of_id->data;
234 pci->host.dev.parent = dev;
235 INIT_LIST_HEAD(&pci->host.windows);
236 INIT_LIST_HEAD(&pci->resources);
237
238 /* Parse our PCI ranges and request their resources */
239 err = gen_pci_parse_request_of_pci_ranges(pci);
240 if (err)
241 return err;
242
243 /* Parse and map our Configuration Space windows */
244 err = gen_pci_parse_map_cfg_windows(pci);
245 if (err) {
246 gen_pci_release_of_pci_ranges(pci);
247 return err;
248 }
249
250 /* Do not reassign resources if probe only */
251 if (!pci_has_flag(PCI_PROBE_ONLY))
252 pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
253
254
255 bus = pci_scan_root_bus(dev, pci->cfg.bus_range->start,
256 &pci->cfg.ops->ops, pci, &pci->resources);
257 if (!bus) {
258 dev_err(dev, "Scanning rootbus failed");
259 return -ENODEV;
260 }
261
262 pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
263
264 if (!pci_has_flag(PCI_PROBE_ONLY)) {
265 pci_bus_size_bridges(bus);
266 pci_bus_assign_resources(bus);
267
268 list_for_each_entry(child, &bus->children, node)
269 pcie_bus_configure_settings(child);
270 }
271
272 pci_bus_add_devices(bus);
273 return 0;
274 }
275
276 static struct platform_driver gen_pci_driver = {
277 .driver = {
278 .name = "pci-host-generic",
279 .of_match_table = gen_pci_of_match,
280 },
281 .probe = gen_pci_probe,
282 };
283 module_platform_driver(gen_pci_driver);
284
285 MODULE_DESCRIPTION("Generic PCI host driver");
286 MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
287 MODULE_LICENSE("GPL v2");
288