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Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -04001/*
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
8#include <linux/list.h>
9#include <linux/slab.h>
10#include <linux/pci.h>
Konrad Rzeszutek Wilk74d33de2011-09-21 17:04:47 -040011#include <linux/mutex.h>
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -040012#include "pciback.h"
13
14#define PCI_SLOT_MAX 32
15
16struct vpci_dev_data {
17 /* Access to dev_list must be protected by lock */
18 struct list_head dev_list[PCI_SLOT_MAX];
Konrad Rzeszutek Wilk74d33de2011-09-21 17:04:47 -040019 struct mutex lock;
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -040020};
21
22static inline struct list_head *list_first(struct list_head *head)
23{
24 return head->next;
25}
26
Konrad Rzeszutek Wilk2ebdc422011-07-11 16:49:41 -040027static struct pci_dev *__xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
28 unsigned int domain,
29 unsigned int bus,
30 unsigned int devfn)
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -040031{
32 struct pci_dev_entry *entry;
33 struct pci_dev *dev = NULL;
34 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -040035
36 if (domain != 0 || bus != 0)
37 return NULL;
38
39 if (PCI_SLOT(devfn) < PCI_SLOT_MAX) {
Konrad Rzeszutek Wilk74d33de2011-09-21 17:04:47 -040040 mutex_lock(&vpci_dev->lock);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -040041
42 list_for_each_entry(entry,
43 &vpci_dev->dev_list[PCI_SLOT(devfn)],
44 list) {
45 if (PCI_FUNC(entry->dev->devfn) == PCI_FUNC(devfn)) {
46 dev = entry->dev;
47 break;
48 }
49 }
50
Konrad Rzeszutek Wilk74d33de2011-09-21 17:04:47 -040051 mutex_unlock(&vpci_dev->lock);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -040052 }
53 return dev;
54}
55
56static inline int match_slot(struct pci_dev *l, struct pci_dev *r)
57{
58 if (pci_domain_nr(l->bus) == pci_domain_nr(r->bus)
59 && l->bus == r->bus && PCI_SLOT(l->devfn) == PCI_SLOT(r->devfn))
60 return 1;
61
62 return 0;
63}
64
Konrad Rzeszutek Wilk2ebdc422011-07-11 16:49:41 -040065static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
66 struct pci_dev *dev, int devid,
67 publish_pci_dev_cb publish_cb)
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -040068{
69 int err = 0, slot, func = -1;
70 struct pci_dev_entry *t, *dev_entry;
71 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -040072
73 if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) {
74 err = -EFAULT;
75 xenbus_dev_fatal(pdev->xdev, err,
76 "Can't export bridges on the virtual PCI bus");
77 goto out;
78 }
79
80 dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL);
81 if (!dev_entry) {
82 err = -ENOMEM;
83 xenbus_dev_fatal(pdev->xdev, err,
84 "Error adding entry to virtual PCI bus");
85 goto out;
86 }
87
88 dev_entry->dev = dev;
89
Konrad Rzeszutek Wilk74d33de2011-09-21 17:04:47 -040090 mutex_lock(&vpci_dev->lock);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -040091
Laszlo Ersek8a5248f2012-10-17 11:55:55 +020092 /*
93 * Keep multi-function devices together on the virtual PCI bus, except
94 * virtual functions.
95 */
96 if (!dev->is_virtfn) {
97 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
98 if (list_empty(&vpci_dev->dev_list[slot]))
99 continue;
100
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400101 t = list_entry(list_first(&vpci_dev->dev_list[slot]),
102 struct pci_dev_entry, list);
103
104 if (match_slot(dev, t->dev)) {
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400105 pr_info(DRV_NAME ": vpci: %s: "
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400106 "assign to virtual slot %d func %d\n",
107 pci_name(dev), slot,
108 PCI_FUNC(dev->devfn));
109 list_add_tail(&dev_entry->list,
110 &vpci_dev->dev_list[slot]);
111 func = PCI_FUNC(dev->devfn);
112 goto unlock;
113 }
114 }
115 }
116
117 /* Assign to a new slot on the virtual PCI bus */
118 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
119 if (list_empty(&vpci_dev->dev_list[slot])) {
Konrad Rzeszutek Wilka92336a2011-07-19 19:40:51 -0400120 printk(KERN_INFO DRV_NAME
121 ": vpci: %s: assign to virtual slot %d\n",
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400122 pci_name(dev), slot);
123 list_add_tail(&dev_entry->list,
124 &vpci_dev->dev_list[slot]);
Laszlo Ersek8a5248f2012-10-17 11:55:55 +0200125 func = dev->is_virtfn ? 0 : PCI_FUNC(dev->devfn);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400126 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:
Konrad Rzeszutek Wilk74d33de2011-09-21 17:04:47 -0400135 mutex_unlock(&vpci_dev->lock);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400136
137 /* Publish this device. */
138 if (!err)
139 err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, func), devid);
140
141out:
142 return err;
143}
144
Konrad Rzeszutek Wilk2ebdc422011-07-11 16:49:41 -0400145static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
146 struct pci_dev *dev)
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400147{
148 int slot;
149 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
150 struct pci_dev *found_dev = NULL;
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400151
Konrad Rzeszutek Wilk74d33de2011-09-21 17:04:47 -0400152 mutex_lock(&vpci_dev->lock);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400153
154 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
Jan Beulich402c5e12011-09-21 16:22:11 -0400155 struct pci_dev_entry *e;
156
157 list_for_each_entry(e, &vpci_dev->dev_list[slot], list) {
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400158 if (e->dev == dev) {
159 list_del(&e->list);
160 found_dev = e->dev;
161 kfree(e);
162 goto out;
163 }
164 }
165 }
166
167out:
Konrad Rzeszutek Wilk74d33de2011-09-21 17:04:47 -0400168 mutex_unlock(&vpci_dev->lock);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400169
170 if (found_dev)
171 pcistub_put_pci_dev(found_dev);
172}
173
Konrad Rzeszutek Wilk2ebdc422011-07-11 16:49:41 -0400174static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400175{
176 int slot;
177 struct vpci_dev_data *vpci_dev;
178
179 vpci_dev = kmalloc(sizeof(*vpci_dev), GFP_KERNEL);
180 if (!vpci_dev)
181 return -ENOMEM;
182
Konrad Rzeszutek Wilk74d33de2011-09-21 17:04:47 -0400183 mutex_init(&vpci_dev->lock);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400184
185 for (slot = 0; slot < PCI_SLOT_MAX; slot++)
186 INIT_LIST_HEAD(&vpci_dev->dev_list[slot]);
187
188 pdev->pci_dev_data = vpci_dev;
189
190 return 0;
191}
192
Konrad Rzeszutek Wilk2ebdc422011-07-11 16:49:41 -0400193static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
194 publish_pci_root_cb publish_cb)
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400195{
196 /* The Virtual PCI bus has only one root */
197 return publish_cb(pdev, 0, 0);
198}
199
Konrad Rzeszutek Wilk2ebdc422011-07-11 16:49:41 -0400200static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400201{
202 int slot;
203 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
204
205 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
206 struct pci_dev_entry *e, *tmp;
207 list_for_each_entry_safe(e, tmp, &vpci_dev->dev_list[slot],
208 list) {
209 list_del(&e->list);
210 pcistub_put_pci_dev(e->dev);
211 kfree(e);
212 }
213 }
214
215 kfree(vpci_dev);
216 pdev->pci_dev_data = NULL;
217}
218
Konrad Rzeszutek Wilk2ebdc422011-07-11 16:49:41 -0400219static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
220 struct xen_pcibk_device *pdev,
221 unsigned int *domain, unsigned int *bus,
222 unsigned int *devfn)
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400223{
224 struct pci_dev_entry *entry;
225 struct pci_dev *dev = NULL;
226 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400227 int found = 0, slot;
228
Konrad Rzeszutek Wilk74d33de2011-09-21 17:04:47 -0400229 mutex_lock(&vpci_dev->lock);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400230 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
231 list_for_each_entry(entry,
232 &vpci_dev->dev_list[slot],
233 list) {
234 dev = entry->dev;
235 if (dev && dev->bus->number == pcidev->bus->number
236 && pci_domain_nr(dev->bus) ==
237 pci_domain_nr(pcidev->bus)
238 && dev->devfn == pcidev->devfn) {
239 found = 1;
240 *domain = 0;
241 *bus = 0;
242 *devfn = PCI_DEVFN(slot,
243 PCI_FUNC(pcidev->devfn));
244 }
245 }
246 }
Dan Carpentere1db4ce2011-09-27 10:07:21 +0300247 mutex_unlock(&vpci_dev->lock);
Konrad Rzeszutek Wilk30edc142009-10-13 17:22:20 -0400248 return found;
249}
Konrad Rzeszutek Wilk2ebdc422011-07-11 16:49:41 -0400250
Jan Beulich402c5e12011-09-21 16:22:11 -0400251const struct xen_pcibk_backend xen_pcibk_vpci_backend = {
Konrad Rzeszutek Wilk2ebdc422011-07-11 16:49:41 -0400252 .name = "vpci",
253 .init = __xen_pcibk_init_devices,
254 .free = __xen_pcibk_release_devices,
255 .find = __xen_pcibk_get_pcifront_dev,
256 .publish = __xen_pcibk_publish_pci_roots,
257 .release = __xen_pcibk_release_pci_dev,
258 .add = __xen_pcibk_add_pci_dev,
259 .get = __xen_pcibk_get_pci_dev,
260};