Commit | Line | Data |
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30edc14b KRW |
1 | /* |
2 | * PCI Backend - Provides a Virtual PCI bus (with real devices) | |
3 | * to the frontend | |
4 | * | |
5 | * Author: Ryan Wilson <hap9@epoch.ncsc.mil> | |
6 | */ | |
7 | ||
283c0972 JP |
8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
9 | ||
30edc14b KRW |
10 | #include <linux/list.h> |
11 | #include <linux/slab.h> | |
12 | #include <linux/pci.h> | |
74d33ded | 13 | #include <linux/mutex.h> |
30edc14b KRW |
14 | #include "pciback.h" |
15 | ||
16 | #define PCI_SLOT_MAX 32 | |
17 | ||
18 | struct vpci_dev_data { | |
19 | /* Access to dev_list must be protected by lock */ | |
20 | struct list_head dev_list[PCI_SLOT_MAX]; | |
74d33ded | 21 | struct mutex lock; |
30edc14b KRW |
22 | }; |
23 | ||
24 | static inline struct list_head *list_first(struct list_head *head) | |
25 | { | |
26 | return head->next; | |
27 | } | |
28 | ||
2ebdc426 KRW |
29 | static 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) | |
30edc14b KRW |
33 | { |
34 | struct pci_dev_entry *entry; | |
35 | struct pci_dev *dev = NULL; | |
36 | struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; | |
30edc14b KRW |
37 | |
38 | if (domain != 0 || bus != 0) | |
39 | return NULL; | |
40 | ||
41 | if (PCI_SLOT(devfn) < PCI_SLOT_MAX) { | |
74d33ded | 42 | mutex_lock(&vpci_dev->lock); |
30edc14b KRW |
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 | ||
74d33ded | 53 | mutex_unlock(&vpci_dev->lock); |
30edc14b KRW |
54 | } |
55 | return dev; | |
56 | } | |
57 | ||
58 | static 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 | ||
2ebdc426 KRW |
67 | static 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) | |
30edc14b KRW |
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; | |
30edc14b KRW |
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 | ||
74d33ded | 92 | mutex_lock(&vpci_dev->lock); |
30edc14b | 93 | |
8a5248fe LE |
94 | /* |
95 | * Keep multi-function devices together on the virtual PCI bus, except | |
96 | * virtual functions. | |
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 | ||
30edc14b KRW |
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)) { | |
283c0972 | 107 | pr_info("vpci: %s: assign to virtual slot %d func %d\n", |
30edc14b KRW |
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 | /* Assign to a new slot on the virtual PCI bus */ | |
119 | for (slot = 0; slot < PCI_SLOT_MAX; slot++) { | |
120 | if (list_empty(&vpci_dev->dev_list[slot])) { | |
283c0972 JP |
121 | pr_info("vpci: %s: assign to virtual slot %d\n", |
122 | pci_name(dev), slot); | |
30edc14b KRW |
123 | list_add_tail(&dev_entry->list, |
124 | &vpci_dev->dev_list[slot]); | |
8a5248fe | 125 | func = dev->is_virtfn ? 0 : PCI_FUNC(dev->devfn); |
30edc14b KRW |
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 | ||
134 | unlock: | |
74d33ded | 135 | mutex_unlock(&vpci_dev->lock); |
30edc14b KRW |
136 | |
137 | /* Publish this device. */ | |
138 | if (!err) | |
139 | err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, func), devid); | |
cea37f87 DY |
140 | else |
141 | kfree(dev_entry); | |
30edc14b KRW |
142 | |
143 | out: | |
144 | return err; | |
145 | } | |
146 | ||
2ebdc426 | 147 | static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev, |
e8801a74 | 148 | struct pci_dev *dev, bool lock) |
30edc14b KRW |
149 | { |
150 | int slot; | |
151 | struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; | |
152 | struct pci_dev *found_dev = NULL; | |
30edc14b | 153 | |
74d33ded | 154 | mutex_lock(&vpci_dev->lock); |
30edc14b KRW |
155 | |
156 | for (slot = 0; slot < PCI_SLOT_MAX; slot++) { | |
402c5e15 JB |
157 | struct pci_dev_entry *e; |
158 | ||
159 | list_for_each_entry(e, &vpci_dev->dev_list[slot], list) { | |
30edc14b KRW |
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 | ||
169 | out: | |
74d33ded | 170 | mutex_unlock(&vpci_dev->lock); |
30edc14b | 171 | |
e8801a74 KRW |
172 | if (found_dev) { |
173 | if (lock) | |
174 | device_lock(&found_dev->dev); | |
30edc14b | 175 | pcistub_put_pci_dev(found_dev); |
e8801a74 KRW |
176 | if (lock) |
177 | device_unlock(&found_dev->dev); | |
178 | } | |
30edc14b KRW |
179 | } |
180 | ||
2ebdc426 | 181 | static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev) |
30edc14b KRW |
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 | ||
74d33ded | 190 | mutex_init(&vpci_dev->lock); |
30edc14b KRW |
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 | ||
2ebdc426 KRW |
200 | static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev, |
201 | publish_pci_root_cb publish_cb) | |
30edc14b KRW |
202 | { |
203 | /* The Virtual PCI bus has only one root */ | |
204 | return publish_cb(pdev, 0, 0); | |
205 | } | |
206 | ||
2ebdc426 | 207 | static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev) |
30edc14b KRW |
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) { | |
e8801a74 | 216 | struct pci_dev *dev = e->dev; |
30edc14b | 217 | list_del(&e->list); |
e8801a74 KRW |
218 | device_lock(&dev->dev); |
219 | pcistub_put_pci_dev(dev); | |
220 | device_unlock(&dev->dev); | |
30edc14b KRW |
221 | kfree(e); |
222 | } | |
223 | } | |
224 | ||
225 | kfree(vpci_dev); | |
226 | pdev->pci_dev_data = NULL; | |
227 | } | |
228 | ||
2ebdc426 KRW |
229 | static 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) | |
30edc14b KRW |
233 | { |
234 | struct pci_dev_entry *entry; | |
235 | struct pci_dev *dev = NULL; | |
236 | struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; | |
30edc14b KRW |
237 | int found = 0, slot; |
238 | ||
74d33ded | 239 | mutex_lock(&vpci_dev->lock); |
30edc14b KRW |
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 | } | |
e1db4cef | 257 | mutex_unlock(&vpci_dev->lock); |
30edc14b KRW |
258 | return found; |
259 | } | |
2ebdc426 | 260 | |
402c5e15 | 261 | const struct xen_pcibk_backend xen_pcibk_vpci_backend = { |
2ebdc426 KRW |
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 | }; |