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(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(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, "_PXM",
96							       NULL, &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(handle, &handle);
103			} while (ACPI_SUCCESS(status));
104		}
105#endif /* CONFIG_ACPI */
106
107		r = HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_add, add);
108		if (r != -ENOSYS)
109			return r;
110		pci_seg_supported = false;
111	}
112
113	if (pci_domain_nr(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			&manage_pci_ext);
127	}
128#endif
129	else if (pci_ari_enabled(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			&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			&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(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					  &device);
165	} else if (pci_domain_nr(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					  &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(&pci_bus_type, &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(&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, &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(&dev_domain_list_spinlock);
286	owner = find_device(dev);
287	if (owner)
288		domain = owner->domain;
289	spin_unlock(&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(sizeof(struct xen_device_domain_owner), GFP_KERNEL);
299	if (!owner)
300		return -ENODEV;
301
302	spin_lock(&dev_domain_list_spinlock);
303	if (find_device(dev)) {
304		spin_unlock(&dev_domain_list_spinlock);
305		kfree(owner);
306		return -EEXIST;
307	}
308	owner->domain = domain;
309	owner->dev = dev;
310	list_add_tail(&owner->list, &dev_domain_list);
311	spin_unlock(&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(&dev_domain_list_spinlock);
321	owner = find_device(dev);
322	if (!owner) {
323		spin_unlock(&dev_domain_list_spinlock);
324		return -ENODEV;
325	}
326	list_del(&owner->list);
327	spin_unlock(&dev_domain_list_spinlock);
328	kfree(owner);
329	return 0;
330}
331EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);
332#endif
333