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 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/bus.h>
31 #include <sys/kernel.h>
32 #include <sys/module.h>
33 #include <sys/pcpu.h>
34 #include <sys/rman.h>
35 #include <sys/smp.h>
36 #include <sys/limits.h>
37 #include <sys/vmmeter.h>
38
39 #include <vm/vm.h>
40 #include <vm/vm_page.h>
41 #include <vm/vm_param.h>
42 #include <vm/vm_phys.h>
43
44 #include <xen/xen-os.h>
45 #include <xen/gnttab.h>
46
47 #include "xenmem_if.h"
48
49 /*
50 * Allocate unused physical memory above 4GB in order to map memory
51 * from foreign domains. We use memory starting at 4GB in order to
52 * prevent clashes with MMIO/ACPI regions.
53 *
54 * Since this is not possible on i386 just use any available memory
55 * chunk above 1MB and hope we don't clash with anything else.
56 *
57 * Other architectures better document MMIO regions and drivers more
58 * reliably reserve them. As such, allow using any unpopulated memory
59 * region.
60 */
61 #ifdef __amd64__
62 #define LOW_MEM_LIMIT 0x100000000ul
63 #elif defined(__i386__)
64 #define LOW_MEM_LIMIT 0x100000ul
65 #else
66 #define LOW_MEM_LIMIT 0
67 #endif
68
69 static void
xenpv_identify(driver_t * driver,device_t parent)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(devclass_find(driver->name), 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, driver->name, 0) == NULL)
84 panic("Unable to attach xenpv bus.");
85 }
86
87 static int
xenpv_probe(device_t dev)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
xenpv_attach(device_t dev)96 xenpv_attach(device_t dev)
97 {
98 int error;
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 error = bus_generic_probe(dev);
106 if (error)
107 return (error);
108
109 error = bus_generic_attach(dev);
110
111 return (error);
112 }
113
114 static struct resource *
xenpv_alloc_physmem(device_t dev,device_t child,int * res_id,size_t size)115 xenpv_alloc_physmem(device_t dev, device_t child, int *res_id, size_t size)
116 {
117 struct resource *res;
118 vm_paddr_t phys_addr;
119 void *virt_addr;
120 int error;
121
122 res = bus_alloc_resource(child, SYS_RES_MEMORY, res_id, LOW_MEM_LIMIT,
123 ~0, size, RF_ACTIVE | RF_UNMAPPED);
124 if (res == NULL)
125 return (NULL);
126
127 phys_addr = rman_get_start(res);
128 error = vm_phys_fictitious_reg_range(phys_addr, phys_addr + size,
129 VM_MEMATTR_XEN);
130 if (error) {
131 bus_release_resource(child, SYS_RES_MEMORY, *res_id, res);
132 return (NULL);
133 }
134 virt_addr = pmap_mapdev_attr(phys_addr, size, VM_MEMATTR_XEN);
135 KASSERT(virt_addr != NULL, ("Failed to create linear mappings"));
136 rman_set_virtual(res, virt_addr);
137
138 return (res);
139 }
140
141 static int
xenpv_free_physmem(device_t dev,device_t child,int res_id,struct resource * res)142 xenpv_free_physmem(device_t dev, device_t child, int res_id, struct resource *res)
143 {
144 vm_paddr_t phys_addr;
145 void *virt_addr;
146 size_t size;
147
148 phys_addr = rman_get_start(res);
149 size = rman_get_size(res);
150 virt_addr = rman_get_virtual(res);
151
152 pmap_unmapdev(virt_addr, size);
153 vm_phys_fictitious_unreg_range(phys_addr, phys_addr + size);
154 return (bus_release_resource(child, SYS_RES_MEMORY, res_id, res));
155 }
156
157 static device_method_t xenpv_methods[] = {
158 /* Device interface */
159 DEVMETHOD(device_identify, xenpv_identify),
160 DEVMETHOD(device_probe, xenpv_probe),
161 DEVMETHOD(device_attach, xenpv_attach),
162 DEVMETHOD(device_suspend, bus_generic_suspend),
163 DEVMETHOD(device_resume, bus_generic_resume),
164
165 /* Bus interface */
166 DEVMETHOD(bus_add_child, bus_generic_add_child),
167 DEVMETHOD(bus_alloc_resource, bus_generic_alloc_resource),
168 DEVMETHOD(bus_release_resource, bus_generic_release_resource),
169 DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
170 DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
171
172 /* Interface to allocate memory for foreign mappings */
173 DEVMETHOD(xenmem_alloc, xenpv_alloc_physmem),
174 DEVMETHOD(xenmem_free, xenpv_free_physmem),
175
176 DEVMETHOD_END
177 };
178
179 static driver_t xenpv_driver = {
180 "xenpv",
181 xenpv_methods,
182 0,
183 };
184
185 DRIVER_MODULE(xenpv, nexus, xenpv_driver, 0, 0);
186
187 struct resource *
xenmem_alloc(device_t dev,int * res_id,size_t size)188 xenmem_alloc(device_t dev, int *res_id, size_t size)
189 {
190 device_t parent;
191
192 parent = device_get_parent(dev);
193 if (parent == NULL)
194 return (NULL);
195 return (XENMEM_ALLOC(parent, dev, res_id, size));
196 }
197
198 int
xenmem_free(device_t dev,int res_id,struct resource * res)199 xenmem_free(device_t dev, int res_id, struct resource *res)
200 {
201 device_t parent;
202
203 parent = device_get_parent(dev);
204 if (parent == NULL)
205 return (ENXIO);
206 return (XENMEM_FREE(parent, dev, res_id, res));
207 }
208