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
,