summaryrefslogtreecommitdiffstats
path: root/drivers/xen/xen-pciback/passthrough.c
blob: f16a30e2a1100f810f22baf720ca40e5c660c0f8 (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
/*
 * PCI Backend - Provides restricted access to the real PCI bus topology
 *               to the frontend
 *
 *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
 */

#include <linux/list.h>
#include <linux/pci.h>
#include <linux/mutex.h>
#include "pciback.h"

struct passthrough_dev_data {
	/* Access to dev_list must be protected by lock */
	struct list_head dev_list;
	struct mutex lock;
};

static struct pci_dev *__xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
					       unsigned int domain,
					       unsigned int bus,
					       unsigned int devfn)
{
	struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
	struct pci_dev_entry *dev_entry;
	struct pci_dev *dev = NULL;

	mutex_lock(&dev_data->lock);

	list_for_each_entry(dev_entry, &dev_data->dev_list, list) {
		if (domain == (unsigned int)pci_domain_nr(dev_entry->dev->bus)
		    && bus == (unsigned int)dev_entry->dev->bus->number
		    && devfn == dev_entry->dev->devfn) {
			dev = dev_entry->dev;
			break;
		}
	}

	mutex_unlock(&dev_data->lock);

	return dev;
}

static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
				   struct pci_dev *dev,
				   int devid, publish_pci_dev_cb publish_cb)
{
	struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
	struct pci_dev_entry *dev_entry;
	unsigned int domain, bus, devfn;
	int err;

	dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL);
	if (!dev_entry)
		return -ENOMEM;
	dev_entry->dev = dev;

	mutex_lock(&dev_data->lock);
	list_add_tail(&dev_entry->list, &dev_data->dev_list);
	mutex_unlock(&dev_data->lock);

	/* Publish this device. */
	domain = (unsigned int)pci_domain_nr(dev->bus);
	bus = (unsigned int)dev->bus->number;
	devfn = dev->devfn;
	err = publish_cb(pdev, domain, bus, devfn, devid);

	return err;
}

static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
					struct pci_dev *dev, bool lock)
{
	struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
	struct pci_dev_entry *dev_entry, *t;
	struct pci_dev *found_dev = NULL;

	mutex_lock(&dev_data->lock);

	list_for_each_entry_safe(dev_entry, t, &dev_data->dev_list, list) {
		if (dev_entry->dev == dev) {
			list_del(&dev_entry->list);
			found_dev = dev_entry->dev;
			kfree(dev_entry);
		}
	}

	mutex_unlock(&dev_data->lock);

	if (found_dev) {
		if (lock)
			device_lock(&found_dev->dev);
		pcistub_put_pci_dev(found_dev);
		if (lock)
			device_unlock(&found_dev->dev);
	}
}

static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
{
	struct passthrough_dev_data *dev_data;

	dev_data = kmalloc(sizeof(*dev_data), GFP_KERNEL);
	if (!dev_data)
		return -ENOMEM;

	mutex_init(&dev_data->lock);

	INIT_LIST_HEAD(&dev_data->dev_list);

	pdev->pci_dev_data = dev_data;

	return 0;
}

static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
					 publish_pci_root_cb publish_root_cb)
{
	int err = 0;
	struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
	struct pci_dev_entry *dev_entry, *e;
	struct pci_dev *dev;
	int found;
	unsigned int domain, bus;

	mutex_lock(&dev_data->lock);

	list_for_each_entry(dev_entry, &dev_data->dev_list, list) {
		/* Only publish this device as a root if none of its
		 * parent bridges are exported
		 */
		found = 0;
		dev = dev_entry->dev->bus->self;
		for (; !found && dev != NULL; dev = dev->bus->self) {
			list_for_each_entry(e, &dev_data->dev_list, list) {
				if (dev == e->dev) {
					found = 1;
					break;
				}
			}
		}

		domain = (unsigned int)pci_domain_nr(dev_entry->dev->bus);
		bus = (unsigned int)dev_entry->dev->bus->number;

		if (!found) {
			err = publish_root_cb(pdev, domain, bus);
			if (err)
				break;
		}
	}

	mutex_unlock(&dev_data->lock);

	return err;
}

static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
{
	struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
	struct pci_dev_entry *dev_entry, *t;

	list_for_each_entry_safe(dev_entry, t, &dev_data->dev_list, list) {
		struct pci_dev *dev = dev_entry->dev;
		list_del(&dev_entry->list);
		device_lock(&dev->dev);
		pcistub_put_pci_dev(dev);
		device_unlock(&dev->dev);
		kfree(dev_entry);
	}

	kfree(dev_data);
	pdev->pci_dev_data = NULL;
}

static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
					struct xen_pcibk_device *pdev,
					unsigned int *domain, unsigned int *bus,
					unsigned int *devfn)
{
	*domain = pci_domain_nr(pcidev->bus);
	*bus = pcidev->bus->number;
	*devfn = pcidev->devfn;
	return 1;
}

const struct xen_pcibk_backend xen_pcibk_passthrough_backend = {
	.name           = "passthrough",
	.init           = __xen_pcibk_init_devices,
	.free		= __xen_pcibk_release_devices,
	.find           = __xen_pcibk_get_pcifront_dev,
	.publish        = __xen_pcibk_publish_pci_roots,
	.release        = __xen_pcibk_release_pci_dev,
	.add            = __xen_pcibk_add_pci_dev,
	.get            = __xen_pcibk_get_pci_dev,
};