FreeBSD/Linux Kernel Cross Reference
sys/x86/xen/xenpv.c
1 /*
2 * Copyright (c) 2014 Roger Pau Monné <roger.pau@citrix.com>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/pcpu.h>
36 #include <sys/rman.h>
37 #include <sys/smp.h>
38 #include <sys/limits.h>
39 #include <sys/vmmeter.h>
40
41 #include <vm/vm.h>
42 #include <vm/vm_page.h>
43 #include <vm/vm_param.h>
44 #include <vm/vm_phys.h>
45
46 #include <xen/xen-os.h>
47 #include <xen/gnttab.h>
48
49 #include "xenmem_if.h"
50
51 /*
52 * Allocate unused physical memory above 4GB in order to map memory
53 * from foreign domains. We use memory starting at 4GB in order to
54 * prevent clashes with MMIO/ACPI regions.
55 *
56 * Since this is not possible on i386 just use any available memory
57 * chunk above 1MB and hope we don't clash with anything else.
58 */
59 #ifdef __amd64__
60 #define LOW_MEM_LIMIT 0x100000000ul
61 #elif defined(__i386__)
62 #define LOW_MEM_LIMIT 0x100000ul
63 #else
64 #error "Unsupported architecture"
65 #endif
66
67 static devclass_t xenpv_devclass;
68
69 static void
70 xenpv_identify(driver_t *driver, device_t parent)
71 {
72 if (!xen_domain())
73 return;
74
75 /* Make sure there's only one xenpv device. */
76 if (devclass_get_device(xenpv_devclass, 0))
77 return;
78
79 /*
80 * The xenpv bus should be the last to attach in order
81 * to properly detect if an ISA bus has already been added.
82 */
83 if (BUS_ADD_CHILD(parent, UINT_MAX, "xenpv", 0) == NULL)
84 panic("Unable to attach xenpv bus.");
85 }
86
87 static int
88 xenpv_probe(device_t dev)
89 {
90
91 device_set_desc(dev, "Xen PV bus");
92 return (BUS_PROBE_NOWILDCARD);
93 }
94
95 static int
96 xenpv_attach(device_t dev)
97 {
98 device_t child;
99
100 /*
101 * Let our child drivers identify any child devices that they
102 * can find. Once that is done attach any devices that we
103 * found.
104 */
105 bus_generic_probe(dev);
106 bus_generic_attach(dev);
107
108 if (!devclass_get_device(devclass_find("isa"), 0)) {
109 child = BUS_ADD_CHILD(dev, 0, "isa", 0);
110 if (child == NULL)
111 panic("Failed to attach ISA bus.");
112 device_probe_and_attach(child);
113 }
114
115 return (0);
116 }
117
118 static struct resource *
119 xenpv_alloc_physmem(device_t dev, device_t child, int *res_id, size_t size)
120 {
121 struct resource *res;
122 vm_paddr_t phys_addr;
123 int error;
124
125 res = bus_alloc_resource(child, SYS_RES_MEMORY, res_id, LOW_MEM_LIMIT,
126 ~0, size, RF_ACTIVE);
127 if (res == NULL)
128 return (NULL);
129
130 phys_addr = rman_get_start(res);
131 error = vm_phys_fictitious_reg_range(phys_addr, phys_addr + size,
132 VM_MEMATTR_DEFAULT);
133 if (error) {
134 bus_release_resource(child, SYS_RES_MEMORY, *res_id, res);
135 return (NULL);
136 }
137
138 return (res);
139 }
140
141 static int
142 xenpv_free_physmem(device_t dev, device_t child, int res_id, struct resource *res)
143 {
144 vm_paddr_t phys_addr;
145 size_t size;
146
147 phys_addr = rman_get_start(res);
148 size = rman_get_size(res);
149
150 vm_phys_fictitious_unreg_range(phys_addr, phys_addr + size);
151 return (bus_release_resource(child, SYS_RES_MEMORY, res_id, res));
152 }
153
154 static device_method_t xenpv_methods[] = {
155 /* Device interface */
156 DEVMETHOD(device_identify, xenpv_identify),
157 DEVMETHOD(device_probe, xenpv_probe),
158 DEVMETHOD(device_attach, xenpv_attach),
159 DEVMETHOD(device_suspend, bus_generic_suspend),
160 DEVMETHOD(device_resume, bus_generic_resume),
161
162 /* Bus interface */
163 DEVMETHOD(bus_add_child, bus_generic_add_child),
164 DEVMETHOD(bus_alloc_resource, bus_generic_alloc_resource),
165 DEVMETHOD(bus_release_resource, bus_generic_release_resource),
166 DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
167 DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
168
169 /* Interface to allocate memory for foreign mappings */
170 DEVMETHOD(xenmem_alloc, xenpv_alloc_physmem),
171 DEVMETHOD(xenmem_free, xenpv_free_physmem),
172
173 DEVMETHOD_END
174 };
175
176 static driver_t xenpv_driver = {
177 "xenpv",
178 xenpv_methods,
179 0,
180 };
181
182 DRIVER_MODULE(xenpv, nexus, xenpv_driver, xenpv_devclass, 0, 0);
183
184 struct resource *
185 xenmem_alloc(device_t dev, int *res_id, size_t size)
186 {
187 device_t parent;
188
189 parent = device_get_parent(dev);
190 if (parent == NULL)
191 return (NULL);
192 return (XENMEM_ALLOC(parent, dev, res_id, size));
193 }
194
195 int
196 xenmem_free(device_t dev, int res_id, struct resource *res)
197 {
198 device_t parent;
199
200 parent = device_get_parent(dev);
201 if (parent == NULL)
202 return (ENXIO);
203 return (XENMEM_FREE(parent, dev, res_id, res));
204 }
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