2 * PCI Backend - Provides a Virtual PCI bus (with real devices)
5 * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 #include <linux/list.h>
11 #include <linux/slab.h>
12 #include <linux/pci.h>
13 #include <linux/mutex.h>
16 #define PCI_SLOT_MAX 32
18 struct vpci_dev_data {
19 /* Access to dev_list must be protected by lock */
20 struct list_head dev_list[PCI_SLOT_MAX];
24 static inline struct list_head *list_first(struct list_head *head)
29 static struct pci_dev *__xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
34 struct pci_dev_entry *entry;
35 struct pci_dev *dev = NULL;
36 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
38 if (domain != 0 || bus != 0)
41 if (PCI_SLOT(devfn) < PCI_SLOT_MAX) {
42 mutex_lock(&vpci_dev->lock);
44 list_for_each_entry(entry,
45 &vpci_dev->dev_list[PCI_SLOT(devfn)],
47 if (PCI_FUNC(entry->dev->devfn) == PCI_FUNC(devfn)) {
53 mutex_unlock(&vpci_dev->lock);
58 static inline int match_slot(struct pci_dev *l, struct pci_dev *r)
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))
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)
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;
75 if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) {
77 xenbus_dev_fatal(pdev->xdev, err,
78 "Can't export bridges on the virtual PCI bus");
82 dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL);
85 xenbus_dev_fatal(pdev->xdev, err,
86 "Error adding entry to virtual PCI bus");
92 mutex_lock(&vpci_dev->lock);
95 * Keep multi-function devices together on the virtual PCI bus, except
98 if (!dev->is_virtfn) {
99 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
100 if (list_empty(&vpci_dev->dev_list[slot]))
103 t = list_entry(list_first(&vpci_dev->dev_list[slot]),
104 struct pci_dev_entry, list);
106 if (match_slot(dev, t->dev)) {
107 pr_info("vpci: %s: assign to virtual slot %d func %d\n",
109 PCI_FUNC(dev->devfn));
110 list_add_tail(&dev_entry->list,
111 &vpci_dev->dev_list[slot]);
112 func = PCI_FUNC(dev->devfn);
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])) {
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);
131 xenbus_dev_fatal(pdev->xdev, err,
132 "No more space on root virtual PCI bus");
135 mutex_unlock(&vpci_dev->lock);
137 /* Publish this device. */
139 err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, func), devid);
145 static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
149 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
150 struct pci_dev *found_dev = NULL;
152 mutex_lock(&vpci_dev->lock);
154 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
155 struct pci_dev_entry *e;
157 list_for_each_entry(e, &vpci_dev->dev_list[slot], list) {
168 mutex_unlock(&vpci_dev->lock);
171 pcistub_put_pci_dev(found_dev);
174 static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
177 struct vpci_dev_data *vpci_dev;
179 vpci_dev = kmalloc(sizeof(*vpci_dev), GFP_KERNEL);
183 mutex_init(&vpci_dev->lock);
185 for (slot = 0; slot < PCI_SLOT_MAX; slot++)
186 INIT_LIST_HEAD(&vpci_dev->dev_list[slot]);
188 pdev->pci_dev_data = vpci_dev;
193 static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
194 publish_pci_root_cb publish_cb)
196 /* The Virtual PCI bus has only one root */
197 return publish_cb(pdev, 0, 0);
200 static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
203 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
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],
210 pcistub_put_pci_dev(e->dev);
216 pdev->pci_dev_data = NULL;
219 static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
220 struct xen_pcibk_device *pdev,
221 unsigned int *domain, unsigned int *bus,
224 struct pci_dev_entry *entry;
225 struct pci_dev *dev = NULL;
226 struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
229 mutex_lock(&vpci_dev->lock);
230 for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
231 list_for_each_entry(entry,
232 &vpci_dev->dev_list[slot],
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) {
242 *devfn = PCI_DEVFN(slot,
243 PCI_FUNC(pcidev->devfn));
247 mutex_unlock(&vpci_dev->lock);
251 const struct xen_pcibk_backend xen_pcibk_vpci_backend = {
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,