1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2009, Intel Corporation.
4 *
5 * Author: Weidong Han <weidong.han@intel.com>
6 */
7
8#include <linux/pci.h>
9#include <linux/acpi.h>
10#include <linux/pci-acpi.h>
11#include <xen/pci.h>
12#include <xen/xen.h>
13#include <xen/interface/physdev.h>
14#include <xen/interface/xen.h>
15
16#include <asm/xen/hypervisor.h>
17#include <asm/xen/hypercall.h>
18#include "../pci/pci.h"
19#ifdef CONFIG_PCI_MMCONFIG
20#include <asm/pci_x86.h>
21
22static int xen_mcfg_late(void);
23#endif
24
25static bool __read_mostly pci_seg_supported = true;
26
27static int xen_add_device(struct device *dev)
28{
29 int r;
30 struct pci_dev *pci_dev = to_pci_dev(dev);
31#ifdef CONFIG_PCI_IOV
32 struct pci_dev *physfn = pci_dev->physfn;
33#endif
34#ifdef CONFIG_PCI_MMCONFIG
35 static bool pci_mcfg_reserved = false;
36 /*
37 * Reserve MCFG areas in Xen on first invocation due to this being
38 * potentially called from inside of acpi_init immediately after
39 * MCFG table has been finally parsed.
40 */
41 if (!pci_mcfg_reserved) {
42 xen_mcfg_late();
43 pci_mcfg_reserved = true;
44 }
45#endif
46 if (pci_seg_supported) {
47 struct {
48 struct physdev_pci_device_add add;
49 uint32_t pxm;
50 } add_ext = {
51 .add.seg = pci_domain_nr(bus: pci_dev->bus),
52 .add.bus = pci_dev->bus->number,
53 .add.devfn = pci_dev->devfn
54 };
55 struct physdev_pci_device_add *add = &add_ext.add;
56
57#ifdef CONFIG_ACPI
58 acpi_handle handle;
59#endif
60
61#ifdef CONFIG_PCI_IOV
62 if (pci_dev->is_virtfn) {
63 add->flags = XEN_PCI_DEV_VIRTFN;
64 add->physfn.bus = physfn->bus->number;
65 add->physfn.devfn = physfn->devfn;
66 } else
67#endif
68 if (pci_ari_enabled(bus: pci_dev->bus) && PCI_SLOT(pci_dev->devfn))
69 add->flags = XEN_PCI_DEV_EXTFN;
70
71#ifdef CONFIG_ACPI
72 handle = ACPI_HANDLE(&pci_dev->dev);
73#ifdef CONFIG_PCI_IOV
74 if (!handle && pci_dev->is_virtfn)
75 handle = ACPI_HANDLE(physfn->bus->bridge);
76#endif
77 if (!handle) {
78 /*
79 * This device was not listed in the ACPI name space at
80 * all. Try to get acpi handle of parent pci bus.
81 */
82 struct pci_bus *pbus;
83 for (pbus = pci_dev->bus; pbus; pbus = pbus->parent) {
84 handle = acpi_pci_get_bridge_handle(pbus);
85 if (handle)
86 break;
87 }
88 }
89 if (handle) {
90 acpi_status status;
91
92 do {
93 unsigned long long pxm;
94
95 status = acpi_evaluate_integer(handle, pathname: "_PXM",
96 NULL, data: &pxm);
97 if (ACPI_SUCCESS(status)) {
98 add->optarr[0] = pxm;
99 add->flags |= XEN_PCI_DEV_PXM;
100 break;
101 }
102 status = acpi_get_parent(object: handle, out_handle: &handle);
103 } while (ACPI_SUCCESS(status));
104 }
105#endif /* CONFIG_ACPI */
106
107 r = HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_add, arg: add);
108 if (r != -ENOSYS)
109 return r;
110 pci_seg_supported = false;
111 }
112
113 if (pci_domain_nr(bus: pci_dev->bus))
114 r = -ENOSYS;
115#ifdef CONFIG_PCI_IOV
116 else if (pci_dev->is_virtfn) {
117 struct physdev_manage_pci_ext manage_pci_ext = {
118 .bus = pci_dev->bus->number,
119 .devfn = pci_dev->devfn,
120 .is_virtfn = 1,
121 .physfn.bus = physfn->bus->number,
122 .physfn.devfn = physfn->devfn,
123 };
124
125 r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
126 arg: &manage_pci_ext);
127 }
128#endif
129 else if (pci_ari_enabled(bus: pci_dev->bus) && PCI_SLOT(pci_dev->devfn)) {
130 struct physdev_manage_pci_ext manage_pci_ext = {
131 .bus = pci_dev->bus->number,
132 .devfn = pci_dev->devfn,
133 .is_extfn = 1,
134 };
135
136 r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
137 arg: &manage_pci_ext);
138 } else {
139 struct physdev_manage_pci manage_pci = {
140 .bus = pci_dev->bus->number,
141 .devfn = pci_dev->devfn,
142 };
143
144 r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add,
145 arg: &manage_pci);
146 }
147
148 return r;
149}
150
151static int xen_remove_device(struct device *dev)
152{
153 int r;
154 struct pci_dev *pci_dev = to_pci_dev(dev);
155
156 if (pci_seg_supported) {
157 struct physdev_pci_device device = {
158 .seg = pci_domain_nr(bus: pci_dev->bus),
159 .bus = pci_dev->bus->number,
160 .devfn = pci_dev->devfn
161 };
162
163 r = HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_remove,
164 arg: &device);
165 } else if (pci_domain_nr(bus: pci_dev->bus))
166 r = -ENOSYS;
167 else {
168 struct physdev_manage_pci manage_pci = {
169 .bus = pci_dev->bus->number,
170 .devfn = pci_dev->devfn
171 };
172
173 r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove,
174 arg: &manage_pci);
175 }
176
177 return r;
178}
179
180static int xen_pci_notifier(struct notifier_block *nb,
181 unsigned long action, void *data)
182{
183 struct device *dev = data;
184 int r = 0;
185
186 switch (action) {
187 case BUS_NOTIFY_ADD_DEVICE:
188 r = xen_add_device(dev);
189 break;
190 case BUS_NOTIFY_DEL_DEVICE:
191 r = xen_remove_device(dev);
192 break;
193 default:
194 return NOTIFY_DONE;
195 }
196 if (r)
197 dev_err(dev, "Failed to %s - passthrough or MSI/MSI-X might fail!\n",
198 action == BUS_NOTIFY_ADD_DEVICE ? "add" :
199 (action == BUS_NOTIFY_DEL_DEVICE ? "delete" : "?"));
200 return NOTIFY_OK;
201}
202
203static struct notifier_block device_nb = {
204 .notifier_call = xen_pci_notifier,
205};
206
207static int __init register_xen_pci_notifier(void)
208{
209 if (!xen_initial_domain())
210 return 0;
211
212 return bus_register_notifier(bus: &pci_bus_type, nb: &device_nb);
213}
214
215arch_initcall(register_xen_pci_notifier);
216
217#ifdef CONFIG_PCI_MMCONFIG
218static int xen_mcfg_late(void)
219{
220 struct pci_mmcfg_region *cfg;
221 int rc;
222
223 if (!xen_initial_domain())
224 return 0;
225
226 if ((pci_probe & PCI_PROBE_MMCONF) == 0)
227 return 0;
228
229 if (list_empty(head: &pci_mmcfg_list))
230 return 0;
231
232 /* Check whether they are in the right area. */
233 list_for_each_entry(cfg, &pci_mmcfg_list, list) {
234 struct physdev_pci_mmcfg_reserved r;
235
236 r.address = cfg->address;
237 r.segment = cfg->segment;
238 r.start_bus = cfg->start_bus;
239 r.end_bus = cfg->end_bus;
240 r.flags = XEN_PCI_MMCFG_RESERVED;
241
242 rc = HYPERVISOR_physdev_op(PHYSDEVOP_pci_mmcfg_reserved, arg: &r);
243 switch (rc) {
244 case 0:
245 case -ENOSYS:
246 continue;
247
248 default:
249 pr_warn("Failed to report MMCONFIG reservation"
250 " state for %s to hypervisor"
251 " (%d)\n",
252 cfg->name, rc);
253 }
254 }
255 return 0;
256}
257#endif
258
259#ifdef CONFIG_XEN_DOM0
260struct xen_device_domain_owner {
261 domid_t domain;
262 struct pci_dev *dev;
263 struct list_head list;
264};
265
266static DEFINE_SPINLOCK(dev_domain_list_spinlock);
267static LIST_HEAD(dev_domain_list);
268
269static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
270{
271 struct xen_device_domain_owner *owner;
272
273 list_for_each_entry(owner, &dev_domain_list, list) {
274 if (owner->dev == dev)
275 return owner;
276 }
277 return NULL;
278}
279
280int xen_find_device_domain_owner(struct pci_dev *dev)
281{
282 struct xen_device_domain_owner *owner;
283 int domain = -ENODEV;
284
285 spin_lock(lock: &dev_domain_list_spinlock);
286 owner = find_device(dev);
287 if (owner)
288 domain = owner->domain;
289 spin_unlock(lock: &dev_domain_list_spinlock);
290 return domain;
291}
292EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
293
294int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain)
295{
296 struct xen_device_domain_owner *owner;
297
298 owner = kzalloc(size: sizeof(struct xen_device_domain_owner), GFP_KERNEL);
299 if (!owner)
300 return -ENODEV;
301
302 spin_lock(lock: &dev_domain_list_spinlock);
303 if (find_device(dev)) {
304 spin_unlock(lock: &dev_domain_list_spinlock);
305 kfree(objp: owner);
306 return -EEXIST;
307 }
308 owner->domain = domain;
309 owner->dev = dev;
310 list_add_tail(new: &owner->list, head: &dev_domain_list);
311 spin_unlock(lock: &dev_domain_list_spinlock);
312 return 0;
313}
314EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
315
316int xen_unregister_device_domain_owner(struct pci_dev *dev)
317{
318 struct xen_device_domain_owner *owner;
319
320 spin_lock(lock: &dev_domain_list_spinlock);
321 owner = find_device(dev);
322 if (!owner) {
323 spin_unlock(lock: &dev_domain_list_spinlock);
324 return -ENODEV;
325 }
326 list_del(entry: &owner->list);
327 spin_unlock(lock: &dev_domain_list_spinlock);
328 kfree(objp: owner);
329 return 0;
330}
331EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);
332#endif
333

source code of linux/drivers/xen/pci.c