summaryrefslogtreecommitdiffstats
path: root/drivers/pci/host/pci-host-common.c
blob: e9f850f07968e3ee443ddeeb53d8ac9d30a4bba7 (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
/*
 * 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>

#include "pci-host-common.h"

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;
}

int pci_host_common_probe(struct platform_device *pdev,
			  struct gen_pci *pci)
{
	int err;
	const char *type;
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct pci_bus *bus, *child;

	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();

	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;
}

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