summaryrefslogtreecommitdiff
path: root/drivers/pci/host/pci-host-generic.c
blob: 1652bc70b1453663cc4a7614d68a3e7c5ea12524 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
/*
 * Simple, generic PCI host controller driver targetting firmware-initialised
 * systems and virtual machines (e.g. the PCI emulation provided by kvmtool).
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Copyright (C) 2014 ARM Limited
 *
 * Author: Will Deacon <will.deacon@arm.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/platform_device.h>

struct gen_pci_cfg_bus_ops {
	u32 bus_shift;
	struct pci_ops ops;
};

struct gen_pci_cfg_windows {
	struct resource				res;
	struct resource				*bus_range;
	void __iomem				**win;

	struct gen_pci_cfg_bus_ops		*ops;
};

struct gen_pci {
	struct pci_host_bridge			host;
	struct gen_pci_cfg_windows		cfg;
	struct list_head			resources;
};

static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
					     unsigned int devfn,
					     int where)
{
	struct gen_pci *pci = bus->sysdata;
	resource_size_t idx = bus->number - pci->cfg.bus_range->start;

	return pci->cfg.win[idx] + ((devfn << 8) | where);
}

static struct gen_pci_cfg_bus_ops gen_pci_cfg_cam_bus_ops = {
	.bus_shift	= 16,
	.ops		= {
		.map_bus	= gen_pci_map_cfg_bus_cam,
		.read		= pci_generic_config_read,
		.write		= pci_generic_config_write,
	}
};

static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
					      unsigned int devfn,
					      int where)
{
	struct gen_pci *pci = bus->sysdata;
	resource_size_t idx = bus->number - pci->cfg.bus_range->start;

	return pci->cfg.win[idx] + ((devfn << 12) | where);
}

static struct gen_pci_cfg_bus_ops gen_pci_cfg_ecam_bus_ops = {
	.bus_shift	= 20,
	.ops		= {
		.map_bus	= gen_pci_map_cfg_bus_ecam,
		.read		= pci_generic_config_read,
		.write		= pci_generic_config_write,
	}
};

static const struct of_device_id gen_pci_of_match[] = {
	{ .compatible = "pci-host-cam-generic",
	  .data = &gen_pci_cfg_cam_bus_ops },

	{ .compatible = "pci-host-ecam-generic",
	  .data = &gen_pci_cfg_ecam_bus_ops },

	{ },
};
MODULE_DEVICE_TABLE(of, gen_pci_of_match);

static void gen_pci_release_of_pci_ranges(struct gen_pci *pci)
{
	pci_free_resource_list(&pci->resources);
}

static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
{
	int err, res_valid = 0;
	struct device *dev = pci->host.dev.parent;
	struct device_node *np = dev->of_node;
	resource_size_t iobase;
	struct resource_entry *win;

	err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pci->resources,
					       &iobase);
	if (err)
		return err;

	resource_list_for_each_entry(win, &pci->resources) {
		struct resource *parent, *res = win->res;

		switch (resource_type(res)) {
		case IORESOURCE_IO:
			parent = &ioport_resource;
			err = pci_remap_iospace(res, iobase);
			if (err) {
				dev_warn(dev, "error %d: failed to map resource %pR\n",
					 err, res);
				continue;
			}
			break;
		case IORESOURCE_MEM:
			parent = &iomem_resource;
			res_valid |= !(res->flags & IORESOURCE_PREFETCH);
			break;
		case IORESOURCE_BUS:
			pci->cfg.bus_range = res;
		default:
			continue;
		}

		err = devm_request_resource(dev, parent, res);
		if (err)
			goto out_release_res;
	}

	if (!res_valid) {
		dev_err(dev, "non-prefetchable memory resource required\n");
		err = -EINVAL;
		goto out_release_res;
	}

	return 0;

out_release_res:
	gen_pci_release_of_pci_ranges(pci);
	return err;
}

static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
{
	int err;
	u8 bus_max;
	resource_size_t busn;
	struct resource *bus_range;
	struct device *dev = pci->host.dev.parent;
	struct device_node *np = dev->of_node;
	u32 sz = 1 << pci->cfg.ops->bus_shift;

	err = of_address_to_resource(np, 0, &pci->cfg.res);
	if (err) {
		dev_err(dev, "missing \"reg\" property\n");
		return err;
	}

	/* Limit the bus-range to fit within reg */
	bus_max = pci->cfg.bus_range->start +
		  (resource_size(&pci->cfg.res) >> pci->cfg.ops->bus_shift) - 1;
	pci->cfg.bus_range->end = min_t(resource_size_t,
					pci->cfg.bus_range->end, bus_max);

	pci->cfg.win = devm_kcalloc(dev, resource_size(pci->cfg.bus_range),
				    sizeof(*pci->cfg.win), GFP_KERNEL);
	if (!pci->cfg.win)
		return -ENOMEM;

	/* Map our Configuration Space windows */
	if (!devm_request_mem_region(dev, pci->cfg.res.start,
				     resource_size(&pci->cfg.res),
				     "Configuration Space"))
		return -ENOMEM;

	bus_range = pci->cfg.bus_range;
	for (busn = bus_range->start; busn <= bus_range->end; ++busn) {
		u32 idx = busn - bus_range->start;

		pci->cfg.win[idx] = devm_ioremap(dev,
						 pci->cfg.res.start + idx * sz,
						 sz);
		if (!pci->cfg.win[idx])
			return -ENOMEM;
	}

	return 0;
}

static int gen_pci_probe(struct platform_device *pdev)
{
	int err;
	const char *type;
	const struct of_device_id *of_id;
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
	struct pci_bus *bus, *child;

	if (!pci)
		return -ENOMEM;

	type = of_get_property(np, "device_type", NULL);
	if (!type || strcmp(type, "pci")) {
		dev_err(dev, "invalid \"device_type\" %s\n", type);
		return -EINVAL;
	}

	of_pci_check_probe_only();

	of_id = of_match_node(gen_pci_of_match, np);
	pci->cfg.ops = (struct gen_pci_cfg_bus_ops *)of_id->data;
	pci->host.dev.parent = dev;
	INIT_LIST_HEAD(&pci->host.windows);
	INIT_LIST_HEAD(&pci->resources);

	/* Parse our PCI ranges and request their resources */
	err = gen_pci_parse_request_of_pci_ranges(pci);
	if (err)
		return err;

	/* Parse and map our Configuration Space windows */
	err = gen_pci_parse_map_cfg_windows(pci);
	if (err) {
		gen_pci_release_of_pci_ranges(pci);
		return err;
	}

	/* Do not reassign resources if probe only */
	if (!pci_has_flag(PCI_PROBE_ONLY))
		pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);


	bus = pci_scan_root_bus(dev, pci->cfg.bus_range->start,
				&pci->cfg.ops->ops, pci, &pci->resources);
	if (!bus) {
		dev_err(dev, "Scanning rootbus failed");
		return -ENODEV;
	}

	pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);

	if (!pci_has_flag(PCI_PROBE_ONLY)) {
		pci_bus_size_bridges(bus);
		pci_bus_assign_resources(bus);

		list_for_each_entry(child, &bus->children, node)
			pcie_bus_configure_settings(child);
	}

	pci_bus_add_devices(bus);
	return 0;
}

static struct platform_driver gen_pci_driver = {
	.driver = {
		.name = "pci-host-generic",
		.of_match_table = gen_pci_of_match,
	},
	.probe = gen_pci_probe,
};
module_platform_driver(gen_pci_driver);

MODULE_DESCRIPTION("Generic PCI host driver");
MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
MODULE_LICENSE("GPL v2");