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7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/list.h>
11#include <linux/slab.h>
12#include <linux/pci.h>
13#include <linux/mutex.h>
14#include "pciback.h"
15
16#define PCI_SLOT_MAX 32
17
18struct vpci_dev_data {
19
20 struct list_head dev_list[PCI_SLOT_MAX];
21 struct mutex lock;
22};
23
24static inline struct list_head *list_first(struct list_head *head)
25{
26 return head->next;
27}
28
29static struct pci_dev *__xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
30 unsigned int domain,
31 unsigned int bus,
32 unsigned int devfn)
33{
34 struct pci_dev_entry *entry;
35 struct pci_dev *dev = NULL;
36 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
37
38 if (domain != 0 || bus != 0)
39 return NULL;
40
41 if (PCI_SLOT(devfn) < PCI_SLOT_MAX) {
42 mutex_lock(&vpci_dev->lock);
43
44 list_for_each_entry(entry,
45 &vpci_dev->dev_list[PCI_SLOT(devfn)],
46 list) {
47 if (PCI_FUNC(entry->dev->devfn) == PCI_FUNC(devfn)) {
48 dev = entry->dev;
49 break;
50 }
51 }
52
53 mutex_unlock(&vpci_dev->lock);
54 }
55 return dev;
56}
57
58static inline int match_slot(struct pci_dev *l, struct pci_dev *r)
59{
60 if (pci_domain_nr(l->bus) == pci_domain_nr(r->bus)
61 && l->bus == r->bus && PCI_SLOT(l->devfn) == PCI_SLOT(r->devfn))
62 return 1;
63
64 return 0;
65}
66
67static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
68 struct pci_dev *dev, int devid,
69 publish_pci_dev_cb publish_cb)
70{
71 int err = 0, slot, func = -1;
72 struct pci_dev_entry *t, *dev_entry;
73 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
74
75 if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) {
76 err = -EFAULT;
77 xenbus_dev_fatal(pdev->xdev, err,
78 "Can't export bridges on the virtual PCI bus");
79 goto out;
80 }
81
82 dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL);
83 if (!dev_entry) {
84 err = -ENOMEM;
85 xenbus_dev_fatal(pdev->xdev, err,
86 "Error adding entry to virtual PCI bus");
87 goto out;
88 }
89
90 dev_entry->dev = dev;
91
92 mutex_lock(&vpci_dev->lock);
93
94
95
96
97
98 if (!dev->is_virtfn) {
99 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
100 if (list_empty(&vpci_dev->dev_list[slot]))
101 continue;
102
103 t = list_entry(list_first(&vpci_dev->dev_list[slot]),
104 struct pci_dev_entry, list);
105
106 if (match_slot(dev, t->dev)) {
107 pr_info("vpci: %s: assign to virtual slot %d func %d\n",
108 pci_name(dev), slot,
109 PCI_FUNC(dev->devfn));
110 list_add_tail(&dev_entry->list,
111 &vpci_dev->dev_list[slot]);
112 func = PCI_FUNC(dev->devfn);
113 goto unlock;
114 }
115 }
116 }
117
118
119 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
120 if (list_empty(&vpci_dev->dev_list[slot])) {
121 pr_info("vpci: %s: assign to virtual slot %d\n",
122 pci_name(dev), slot);
123 list_add_tail(&dev_entry->list,
124 &vpci_dev->dev_list[slot]);
125 func = dev->is_virtfn ? 0 : PCI_FUNC(dev->devfn);
126 goto unlock;
127 }
128 }
129
130 err = -ENOMEM;
131 xenbus_dev_fatal(pdev->xdev, err,
132 "No more space on root virtual PCI bus");
133
134unlock:
135 mutex_unlock(&vpci_dev->lock);
136
137
138 if (!err)
139 err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, func), devid);
140 else
141 kfree(dev_entry);
142
143out:
144 return err;
145}
146
147static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
148 struct pci_dev *dev, bool lock)
149{
150 int slot;
151 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
152 struct pci_dev *found_dev = NULL;
153
154 mutex_lock(&vpci_dev->lock);
155
156 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
157 struct pci_dev_entry *e;
158
159 list_for_each_entry(e, &vpci_dev->dev_list[slot], list) {
160 if (e->dev == dev) {
161 list_del(&e->list);
162 found_dev = e->dev;
163 kfree(e);
164 goto out;
165 }
166 }
167 }
168
169out:
170 mutex_unlock(&vpci_dev->lock);
171
172 if (found_dev) {
173 if (lock)
174 device_lock(&found_dev->dev);
175 pcistub_put_pci_dev(found_dev);
176 if (lock)
177 device_unlock(&found_dev->dev);
178 }
179}
180
181static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
182{
183 int slot;
184 struct vpci_dev_data *vpci_dev;
185
186 vpci_dev = kmalloc(sizeof(*vpci_dev), GFP_KERNEL);
187 if (!vpci_dev)
188 return -ENOMEM;
189
190 mutex_init(&vpci_dev->lock);
191
192 for (slot = 0; slot < PCI_SLOT_MAX; slot++)
193 INIT_LIST_HEAD(&vpci_dev->dev_list[slot]);
194
195 pdev->pci_dev_data = vpci_dev;
196
197 return 0;
198}
199
200static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
201 publish_pci_root_cb publish_cb)
202{
203
204 return publish_cb(pdev, 0, 0);
205}
206
207static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
208{
209 int slot;
210 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
211
212 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
213 struct pci_dev_entry *e, *tmp;
214 list_for_each_entry_safe(e, tmp, &vpci_dev->dev_list[slot],
215 list) {
216 struct pci_dev *dev = e->dev;
217 list_del(&e->list);
218 device_lock(&dev->dev);
219 pcistub_put_pci_dev(dev);
220 device_unlock(&dev->dev);
221 kfree(e);
222 }
223 }
224
225 kfree(vpci_dev);
226 pdev->pci_dev_data = NULL;
227}
228
229static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
230 struct xen_pcibk_device *pdev,
231 unsigned int *domain, unsigned int *bus,
232 unsigned int *devfn)
233{
234 struct pci_dev_entry *entry;
235 struct pci_dev *dev = NULL;
236 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
237 int found = 0, slot;
238
239 mutex_lock(&vpci_dev->lock);
240 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
241 list_for_each_entry(entry,
242 &vpci_dev->dev_list[slot],
243 list) {
244 dev = entry->dev;
245 if (dev && dev->bus->number == pcidev->bus->number
246 && pci_domain_nr(dev->bus) ==
247 pci_domain_nr(pcidev->bus)
248 && dev->devfn == pcidev->devfn) {
249 found = 1;
250 *domain = 0;
251 *bus = 0;
252 *devfn = PCI_DEVFN(slot,
253 PCI_FUNC(pcidev->devfn));
254 }
255 }
256 }
257 mutex_unlock(&vpci_dev->lock);
258 return found;
259}
260
261const struct xen_pcibk_backend xen_pcibk_vpci_backend = {
262 .name = "vpci",
263 .init = __xen_pcibk_init_devices,
264 .free = __xen_pcibk_release_devices,
265 .find = __xen_pcibk_get_pcifront_dev,
266 .publish = __xen_pcibk_publish_pci_roots,
267 .release = __xen_pcibk_release_pci_dev,
268 .add = __xen_pcibk_add_pci_dev,
269 .get = __xen_pcibk_get_pci_dev,
270};
271
