2
* PCI Backend - Provides a Virtual PCI bus (with real devices)
5
* Author: Ryan Wilson <hap9@epoch.ncsc.mil>
8
#include <linux/list.h>
9
#include <linux/slab.h>
10
#include <linux/pci.h>
11
#include <linux/mutex.h>
14
#define PCI_SLOT_MAX 32
16
struct vpci_dev_data {
17
/* Access to dev_list must be protected by lock */
18
struct list_head dev_list[PCI_SLOT_MAX];
22
static inline struct list_head *list_first(struct list_head *head)
27
static struct pci_dev *__xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
32
struct pci_dev_entry *entry;
33
struct pci_dev *dev = NULL;
34
struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
36
if (domain != 0 || bus != 0)
39
if (PCI_SLOT(devfn) < PCI_SLOT_MAX) {
40
mutex_lock(&vpci_dev->lock);
42
list_for_each_entry(entry,
43
&vpci_dev->dev_list[PCI_SLOT(devfn)],
45
if (PCI_FUNC(entry->dev->devfn) == PCI_FUNC(devfn)) {
51
mutex_unlock(&vpci_dev->lock);
56
static inline int match_slot(struct pci_dev *l, struct pci_dev *r)
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))
65
static 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)
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;
73
if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) {
75
xenbus_dev_fatal(pdev->xdev, err,
76
"Can't export bridges on the virtual PCI bus");
80
dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL);
83
xenbus_dev_fatal(pdev->xdev, err,
84
"Error adding entry to virtual PCI bus");
90
mutex_lock(&vpci_dev->lock);
92
/* Keep multi-function devices together on the virtual PCI bus */
93
for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
94
if (!list_empty(&vpci_dev->dev_list[slot])) {
95
t = list_entry(list_first(&vpci_dev->dev_list[slot]),
96
struct pci_dev_entry, list);
98
if (match_slot(dev, t->dev)) {
99
pr_info(DRV_NAME ": vpci: %s: "
100
"assign to virtual slot %d func %d\n",
102
PCI_FUNC(dev->devfn));
103
list_add_tail(&dev_entry->list,
104
&vpci_dev->dev_list[slot]);
105
func = PCI_FUNC(dev->devfn);
111
/* Assign to a new slot on the virtual PCI bus */
112
for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
113
if (list_empty(&vpci_dev->dev_list[slot])) {
114
printk(KERN_INFO DRV_NAME
115
": vpci: %s: assign to virtual slot %d\n",
116
pci_name(dev), slot);
117
list_add_tail(&dev_entry->list,
118
&vpci_dev->dev_list[slot]);
119
func = PCI_FUNC(dev->devfn);
125
xenbus_dev_fatal(pdev->xdev, err,
126
"No more space on root virtual PCI bus");
129
mutex_unlock(&vpci_dev->lock);
131
/* Publish this device. */
133
err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, func), devid);
139
static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
143
struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
144
struct pci_dev *found_dev = NULL;
146
mutex_lock(&vpci_dev->lock);
148
for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
149
struct pci_dev_entry *e;
151
list_for_each_entry(e, &vpci_dev->dev_list[slot], list) {
162
mutex_unlock(&vpci_dev->lock);
165
pcistub_put_pci_dev(found_dev);
168
static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
171
struct vpci_dev_data *vpci_dev;
173
vpci_dev = kmalloc(sizeof(*vpci_dev), GFP_KERNEL);
177
mutex_init(&vpci_dev->lock);
179
for (slot = 0; slot < PCI_SLOT_MAX; slot++)
180
INIT_LIST_HEAD(&vpci_dev->dev_list[slot]);
182
pdev->pci_dev_data = vpci_dev;
187
static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
188
publish_pci_root_cb publish_cb)
190
/* The Virtual PCI bus has only one root */
191
return publish_cb(pdev, 0, 0);
194
static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
197
struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
199
for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
200
struct pci_dev_entry *e, *tmp;
201
list_for_each_entry_safe(e, tmp, &vpci_dev->dev_list[slot],
204
pcistub_put_pci_dev(e->dev);
210
pdev->pci_dev_data = NULL;
213
static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
214
struct xen_pcibk_device *pdev,
215
unsigned int *domain, unsigned int *bus,
218
struct pci_dev_entry *entry;
219
struct pci_dev *dev = NULL;
220
struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
223
mutex_lock(&vpci_dev->lock);
224
for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
225
list_for_each_entry(entry,
226
&vpci_dev->dev_list[slot],
229
if (dev && dev->bus->number == pcidev->bus->number
230
&& pci_domain_nr(dev->bus) ==
231
pci_domain_nr(pcidev->bus)
232
&& dev->devfn == pcidev->devfn) {
236
*devfn = PCI_DEVFN(slot,
237
PCI_FUNC(pcidev->devfn));
241
mutex_unlock(&vpci_dev->lock);
245
const struct xen_pcibk_backend xen_pcibk_vpci_backend = {
247
.init = __xen_pcibk_init_devices,
248
.free = __xen_pcibk_release_devices,
249
.find = __xen_pcibk_get_pcifront_dev,
250
.publish = __xen_pcibk_publish_pci_roots,
251
.release = __xen_pcibk_release_pci_dev,
252
.add = __xen_pcibk_add_pci_dev,
253
.get = __xen_pcibk_get_pci_dev,