xref: /openbmc/linux/drivers/xen/pci.c (revision cf21eb6a)
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 
22 static int xen_mcfg_late(void);
23 #endif
24 
25 static bool __read_mostly pci_seg_supported = true;
26 
27 static 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 
151 static 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 
180 static 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 
203 static struct notifier_block device_nb = {
204 	.notifier_call = xen_pci_notifier,
205 };
206 
207 static 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 
215 arch_initcall(register_xen_pci_notifier);
216 
217 #ifdef CONFIG_PCI_MMCONFIG
218 static 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
260 struct xen_device_domain_owner {
261 	domid_t domain;
262 	struct pci_dev *dev;
263 	struct list_head list;
264 };
265 
266 static DEFINE_SPINLOCK(dev_domain_list_spinlock);
267 static LIST_HEAD(dev_domain_list);
268 
269 static 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 
280 int 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 }
292 EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
293 
294 int 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 }
314 EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
315 
316 int 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 }
331 EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);
332 #endif
333