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8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10#define dev_fmt pr_fmt
11
12#include <linux/list.h>
13#include <linux/slab.h>
14#include <linux/pci.h>
15#include <linux/mutex.h>
16#include "pciback.h"
17
18#define PCI_SLOT_MAX 32
19
20struct vpci_dev_data {
21
22 struct list_head dev_list[PCI_SLOT_MAX];
23 struct mutex lock;
24};
25
26static inline struct list_head *list_first(struct list_head *head)
27{
28 return head->next;
29}
30
31static struct pci_dev *__xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
32 unsigned int domain,
33 unsigned int bus,
34 unsigned int devfn)
35{
36 struct pci_dev_entry *entry;
37 struct pci_dev *dev = NULL;
38 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
39
40 if (domain != 0 || bus != 0)
41 return NULL;
42
43 if (PCI_SLOT(devfn) < PCI_SLOT_MAX) {
44 mutex_lock(&vpci_dev->lock);
45
46 list_for_each_entry(entry,
47 &vpci_dev->dev_list[PCI_SLOT(devfn)],
48 list) {
49 if (PCI_FUNC(entry->dev->devfn) == PCI_FUNC(devfn)) {
50 dev = entry->dev;
51 break;
52 }
53 }
54
55 mutex_unlock(&vpci_dev->lock);
56 }
57 return dev;
58}
59
60static inline int match_slot(struct pci_dev *l, struct pci_dev *r)
61{
62 if (pci_domain_nr(l->bus) == pci_domain_nr(r->bus)
63 && l->bus == r->bus && PCI_SLOT(l->devfn) == PCI_SLOT(r->devfn))
64 return 1;
65
66 return 0;
67}
68
69static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
70 struct pci_dev *dev, int devid,
71 publish_pci_dev_cb publish_cb)
72{
73 int err = 0, slot, func = PCI_FUNC(dev->devfn);
74 struct pci_dev_entry *t, *dev_entry;
75 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
76
77 if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) {
78 err = -EFAULT;
79 xenbus_dev_fatal(pdev->xdev, err,
80 "Can't export bridges on the virtual PCI bus");
81 goto out;
82 }
83
84 dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL);
85 if (!dev_entry) {
86 err = -ENOMEM;
87 xenbus_dev_fatal(pdev->xdev, err,
88 "Error adding entry to virtual PCI bus");
89 goto out;
90 }
91
92 dev_entry->dev = dev;
93
94 mutex_lock(&vpci_dev->lock);
95
96
97
98
99
100
101
102 if (!dev->is_virtfn || func) {
103 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
104 if (list_empty(&vpci_dev->dev_list[slot]))
105 continue;
106
107 t = list_entry(list_first(&vpci_dev->dev_list[slot]),
108 struct pci_dev_entry, list);
109 if (t->dev->is_virtfn && !PCI_FUNC(t->dev->devfn))
110 continue;
111
112 if (match_slot(dev, t->dev)) {
113 dev_info(&dev->dev, "vpci: assign to virtual slot %d func %d\n",
114 slot, func);
115 list_add_tail(&dev_entry->list,
116 &vpci_dev->dev_list[slot]);
117 goto unlock;
118 }
119 }
120 }
121
122
123 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
124 if (list_empty(&vpci_dev->dev_list[slot])) {
125 dev_info(&dev->dev, "vpci: assign to virtual slot %d\n",
126 slot);
127 list_add_tail(&dev_entry->list,
128 &vpci_dev->dev_list[slot]);
129 goto unlock;
130 }
131 }
132
133 err = -ENOMEM;
134 xenbus_dev_fatal(pdev->xdev, err,
135 "No more space on root virtual PCI bus");
136
137unlock:
138 mutex_unlock(&vpci_dev->lock);
139
140
141 if (!err)
142 err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, func), devid);
143 else
144 kfree(dev_entry);
145
146out:
147 return err;
148}
149
150static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
151 struct pci_dev *dev, bool lock)
152{
153 int slot;
154 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
155 struct pci_dev *found_dev = NULL;
156
157 mutex_lock(&vpci_dev->lock);
158
159 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
160 struct pci_dev_entry *e;
161
162 list_for_each_entry(e, &vpci_dev->dev_list[slot], list) {
163 if (e->dev == dev) {
164 list_del(&e->list);
165 found_dev = e->dev;
166 kfree(e);
167 goto out;
168 }
169 }
170 }
171
172out:
173 mutex_unlock(&vpci_dev->lock);
174
175 if (found_dev) {
176 if (lock)
177 device_lock(&found_dev->dev);
178 pcistub_put_pci_dev(found_dev);
179 if (lock)
180 device_unlock(&found_dev->dev);
181 }
182}
183
184static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
185{
186 int slot;
187 struct vpci_dev_data *vpci_dev;
188
189 vpci_dev = kmalloc(sizeof(*vpci_dev), GFP_KERNEL);
190 if (!vpci_dev)
191 return -ENOMEM;
192
193 mutex_init(&vpci_dev->lock);
194
195 for (slot = 0; slot < PCI_SLOT_MAX; slot++)
196 INIT_LIST_HEAD(&vpci_dev->dev_list[slot]);
197
198 pdev->pci_dev_data = vpci_dev;
199
200 return 0;
201}
202
203static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
204 publish_pci_root_cb publish_cb)
205{
206
207 return publish_cb(pdev, 0, 0);
208}
209
210static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
211{
212 int slot;
213 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
214
215 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
216 struct pci_dev_entry *e, *tmp;
217 list_for_each_entry_safe(e, tmp, &vpci_dev->dev_list[slot],
218 list) {
219 struct pci_dev *dev = e->dev;
220 list_del(&e->list);
221 device_lock(&dev->dev);
222 pcistub_put_pci_dev(dev);
223 device_unlock(&dev->dev);
224 kfree(e);
225 }
226 }
227
228 kfree(vpci_dev);
229 pdev->pci_dev_data = NULL;
230}
231
232static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
233 struct xen_pcibk_device *pdev,
234 unsigned int *domain, unsigned int *bus,
235 unsigned int *devfn)
236{
237 struct pci_dev_entry *entry;
238 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
239 int found = 0, slot;
240
241 mutex_lock(&vpci_dev->lock);
242 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
243 list_for_each_entry(entry,
244 &vpci_dev->dev_list[slot],
245 list) {
246 if (entry->dev == pcidev) {
247 found = 1;
248 *domain = 0;
249 *bus = 0;
250 *devfn = PCI_DEVFN(slot,
251 PCI_FUNC(pcidev->devfn));
252 }
253 }
254 }
255 mutex_unlock(&vpci_dev->lock);
256 return found;
257}
258
259const struct xen_pcibk_backend xen_pcibk_vpci_backend = {
260 .name = "vpci",
261 .init = __xen_pcibk_init_devices,
262 .free = __xen_pcibk_release_devices,
263 .find = __xen_pcibk_get_pcifront_dev,
264 .publish = __xen_pcibk_publish_pci_roots,
265 .release = __xen_pcibk_release_pci_dev,
266 .add = __xen_pcibk_add_pci_dev,
267 .get = __xen_pcibk_get_pci_dev,
268};
269
