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,