xref: /openbmc/linux/drivers/xen/pci.c (revision 4beec1d7)
1 /*
2  * Copyright (c) 2009, Intel Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15  * Place - Suite 330, Boston, MA 02111-1307 USA.
16  *
17  * Author: Weidong Han <weidong.han@intel.com>
18  */
19 
20 #include <linux/pci.h>
21 #include <linux/acpi.h>
22 #include <linux/pci-acpi.h>
23 #include <xen/xen.h>
24 #include <xen/interface/physdev.h>
25 #include <xen/interface/xen.h>
26 
27 #include <asm/xen/hypervisor.h>
28 #include <asm/xen/hypercall.h>
29 #include "../pci/pci.h"
30 #ifdef CONFIG_PCI_MMCONFIG
31 #include <asm/pci_x86.h>
32 #endif
33 
34 static bool __read_mostly pci_seg_supported = true;
35 
36 static int xen_add_device(struct device *dev)
37 {
38 	int r;
39 	struct pci_dev *pci_dev = to_pci_dev(dev);
40 #ifdef CONFIG_PCI_IOV
41 	struct pci_dev *physfn = pci_dev->physfn;
42 #endif
43 
44 	if (pci_seg_supported) {
45 		struct {
46 			struct physdev_pci_device_add add;
47 			uint32_t pxm;
48 		} add_ext = {
49 			.add.seg = pci_domain_nr(pci_dev->bus),
50 			.add.bus = pci_dev->bus->number,
51 			.add.devfn = pci_dev->devfn
52 		};
53 		struct physdev_pci_device_add *add = &add_ext.add;
54 
55 #ifdef CONFIG_ACPI
56 		acpi_handle handle;
57 #endif
58 
59 #ifdef CONFIG_PCI_IOV
60 		if (pci_dev->is_virtfn) {
61 			add->flags = XEN_PCI_DEV_VIRTFN;
62 			add->physfn.bus = physfn->bus->number;
63 			add->physfn.devfn = physfn->devfn;
64 		} else
65 #endif
66 		if (pci_ari_enabled(pci_dev->bus) && PCI_SLOT(pci_dev->devfn))
67 			add->flags = XEN_PCI_DEV_EXTFN;
68 
69 #ifdef CONFIG_ACPI
70 		handle = ACPI_HANDLE(&pci_dev->dev);
71 #ifdef CONFIG_PCI_IOV
72 		if (!handle && pci_dev->is_virtfn)
73 			handle = ACPI_HANDLE(physfn->bus->bridge);
74 #endif
75 		if (!handle) {
76 			/*
77 			 * This device was not listed in the ACPI name space at
78 			 * all. Try to get acpi handle of parent pci bus.
79 			 */
80 			struct pci_bus *pbus;
81 			for (pbus = pci_dev->bus; pbus; pbus = pbus->parent) {
82 				handle = acpi_pci_get_bridge_handle(pbus);
83 				if (handle)
84 					break;
85 			}
86 		}
87 		if (handle) {
88 			acpi_status status;
89 
90 			do {
91 				unsigned long long pxm;
92 
93 				status = acpi_evaluate_integer(handle, "_PXM",
94 							       NULL, &pxm);
95 				if (ACPI_SUCCESS(status)) {
96 					add->optarr[0] = pxm;
97 					add->flags |= XEN_PCI_DEV_PXM;
98 					break;
99 				}
100 				status = acpi_get_parent(handle, &handle);
101 			} while (ACPI_SUCCESS(status));
102 		}
103 #endif /* CONFIG_ACPI */
104 
105 		r = HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_add, add);
106 		if (r != -ENOSYS)
107 			return r;
108 		pci_seg_supported = false;
109 	}
110 
111 	if (pci_domain_nr(pci_dev->bus))
112 		r = -ENOSYS;
113 #ifdef CONFIG_PCI_IOV
114 	else if (pci_dev->is_virtfn) {
115 		struct physdev_manage_pci_ext manage_pci_ext = {
116 			.bus		= pci_dev->bus->number,
117 			.devfn		= pci_dev->devfn,
118 			.is_virtfn 	= 1,
119 			.physfn.bus	= physfn->bus->number,
120 			.physfn.devfn	= physfn->devfn,
121 		};
122 
123 		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
124 			&manage_pci_ext);
125 	}
126 #endif
127 	else if (pci_ari_enabled(pci_dev->bus) && PCI_SLOT(pci_dev->devfn)) {
128 		struct physdev_manage_pci_ext manage_pci_ext = {
129 			.bus		= pci_dev->bus->number,
130 			.devfn		= pci_dev->devfn,
131 			.is_extfn	= 1,
132 		};
133 
134 		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
135 			&manage_pci_ext);
136 	} else {
137 		struct physdev_manage_pci manage_pci = {
138 			.bus	= pci_dev->bus->number,
139 			.devfn	= pci_dev->devfn,
140 		};
141 
142 		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add,
143 			&manage_pci);
144 	}
145 
146 	return r;
147 }
148 
149 static int xen_remove_device(struct device *dev)
150 {
151 	int r;
152 	struct pci_dev *pci_dev = to_pci_dev(dev);
153 
154 	if (pci_seg_supported) {
155 		struct physdev_pci_device device = {
156 			.seg = pci_domain_nr(pci_dev->bus),
157 			.bus = pci_dev->bus->number,
158 			.devfn = pci_dev->devfn
159 		};
160 
161 		r = HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_remove,
162 					  &device);
163 	} else if (pci_domain_nr(pci_dev->bus))
164 		r = -ENOSYS;
165 	else {
166 		struct physdev_manage_pci manage_pci = {
167 			.bus = pci_dev->bus->number,
168 			.devfn = pci_dev->devfn
169 		};
170 
171 		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove,
172 					  &manage_pci);
173 	}
174 
175 	return r;
176 }
177 
178 static int xen_pci_notifier(struct notifier_block *nb,
179 			    unsigned long action, void *data)
180 {
181 	struct device *dev = data;
182 	int r = 0;
183 
184 	switch (action) {
185 	case BUS_NOTIFY_ADD_DEVICE:
186 		r = xen_add_device(dev);
187 		break;
188 	case BUS_NOTIFY_DEL_DEVICE:
189 		r = xen_remove_device(dev);
190 		break;
191 	default:
192 		return NOTIFY_DONE;
193 	}
194 	if (r)
195 		dev_err(dev, "Failed to %s - passthrough or MSI/MSI-X might fail!\n",
196 			action == BUS_NOTIFY_ADD_DEVICE ? "add" :
197 			(action == BUS_NOTIFY_DEL_DEVICE ? "delete" : "?"));
198 	return NOTIFY_OK;
199 }
200 
201 static struct notifier_block device_nb = {
202 	.notifier_call = xen_pci_notifier,
203 };
204 
205 static int __init register_xen_pci_notifier(void)
206 {
207 	if (!xen_initial_domain())
208 		return 0;
209 
210 	return bus_register_notifier(&pci_bus_type, &device_nb);
211 }
212 
213 arch_initcall(register_xen_pci_notifier);
214 
215 #ifdef CONFIG_PCI_MMCONFIG
216 static int __init xen_mcfg_late(void)
217 {
218 	struct pci_mmcfg_region *cfg;
219 	int rc;
220 
221 	if (!xen_initial_domain())
222 		return 0;
223 
224 	if ((pci_probe & PCI_PROBE_MMCONF) == 0)
225 		return 0;
226 
227 	if (list_empty(&pci_mmcfg_list))
228 		return 0;
229 
230 	/* Check whether they are in the right area. */
231 	list_for_each_entry(cfg, &pci_mmcfg_list, list) {
232 		struct physdev_pci_mmcfg_reserved r;
233 
234 		r.address = cfg->address;
235 		r.segment = cfg->segment;
236 		r.start_bus = cfg->start_bus;
237 		r.end_bus = cfg->end_bus;
238 		r.flags = XEN_PCI_MMCFG_RESERVED;
239 
240 		rc = HYPERVISOR_physdev_op(PHYSDEVOP_pci_mmcfg_reserved, &r);
241 		switch (rc) {
242 		case 0:
243 		case -ENOSYS:
244 			continue;
245 
246 		default:
247 			pr_warn("Failed to report MMCONFIG reservation"
248 				" state for %s to hypervisor"
249 				" (%d)\n",
250 				cfg->name, rc);
251 		}
252 	}
253 	return 0;
254 }
255 /*
256  * Needs to be done after acpi_init which are subsys_initcall.
257  */
258 subsys_initcall_sync(xen_mcfg_late);
259 #endif
260