xenpv.c revision 331017 
1/*
2 * Copyright (c) 2014 Roger Pau Monn�� <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: stable/11/sys/x86/xen/xenpv.c 331017 2018-03-15 19:08:33Z kevans $");
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 and hope we don't clash with anything else.
58 */
59#ifdef __amd64__
60#define LOW_MEM_LIMIT	0x100000000ul
61#else
62#define LOW_MEM_LIMIT	0
63#endif
64
65static devclass_t xenpv_devclass;
66
67static void
68xenpv_identify(driver_t *driver, device_t parent)
69{
70	if (!xen_domain())
71		return;
72
73	/* Make sure there's only one xenpv device. */
74	if (devclass_get_device(xenpv_devclass, 0))
75		return;
76
77	/*
78	 * The xenpv bus should be the last to attach in order
79	 * to properly detect if an ISA bus has already been added.
80	 */
81	if (BUS_ADD_CHILD(parent, UINT_MAX, "xenpv", 0) == NULL)
82		panic("Unable to attach xenpv bus.");
83}
84
85static int
86xenpv_probe(device_t dev)
87{
88
89	device_set_desc(dev, "Xen PV bus");
90	return (BUS_PROBE_NOWILDCARD);
91}
92
93static int
94xenpv_attach(device_t dev)
95{
96	device_t child;
97
98	/*
99	 * Let our child drivers identify any child devices that they
100	 * can find.  Once that is done attach any devices that we
101	 * found.
102	 */
103	bus_generic_probe(dev);
104	bus_generic_attach(dev);
105
106	if (!devclass_get_device(devclass_find("isa"), 0)) {
107		child = BUS_ADD_CHILD(dev, 0, "isa", 0);
108		if (child == NULL)
109			panic("Failed to attach ISA bus.");
110		device_probe_and_attach(child);
111	}
112
113	return (0);
114}
115
116static struct resource *
117xenpv_alloc_physmem(device_t dev, device_t child, int *res_id, size_t size)
118{
119	struct resource *res;
120	vm_paddr_t phys_addr;
121	int error;
122
123	res = bus_alloc_resource(child, SYS_RES_MEMORY, res_id, LOW_MEM_LIMIT,
124	    ~0, size, RF_ACTIVE);
125	if (res == NULL)
126		return (NULL);
127
128	phys_addr = rman_get_start(res);
129	error = vm_phys_fictitious_reg_range(phys_addr, phys_addr + size,
130	    VM_MEMATTR_DEFAULT);
131	if (error) {
132		bus_release_resource(child, SYS_RES_MEMORY, *res_id, res);
133		return (NULL);
134	}
135
136	return (res);
137}
138
139static int
140xenpv_free_physmem(device_t dev, device_t child, int res_id, struct resource *res)
141{
142	vm_paddr_t phys_addr;
143	size_t size;
144
145	phys_addr = rman_get_start(res);
146	size = rman_get_size(res);
147
148	vm_phys_fictitious_unreg_range(phys_addr, phys_addr + size);
149	return (bus_release_resource(child, SYS_RES_MEMORY, res_id, res));
150}
151
152static device_method_t xenpv_methods[] = {
153	/* Device interface */
154	DEVMETHOD(device_identify,		xenpv_identify),
155	DEVMETHOD(device_probe,			xenpv_probe),
156	DEVMETHOD(device_attach,		xenpv_attach),
157	DEVMETHOD(device_suspend,		bus_generic_suspend),
158	DEVMETHOD(device_resume,		bus_generic_resume),
159
160	/* Bus interface */
161	DEVMETHOD(bus_add_child,		bus_generic_add_child),
162	DEVMETHOD(bus_alloc_resource,		bus_generic_alloc_resource),
163	DEVMETHOD(bus_release_resource,		bus_generic_release_resource),
164	DEVMETHOD(bus_activate_resource,	bus_generic_activate_resource),
165	DEVMETHOD(bus_deactivate_resource,	bus_generic_deactivate_resource),
166
167	/* Interface to allocate memory for foreign mappings */
168	DEVMETHOD(xenmem_alloc,			xenpv_alloc_physmem),
169	DEVMETHOD(xenmem_free,			xenpv_free_physmem),
170
171	DEVMETHOD_END
172};
173
174static driver_t xenpv_driver = {
175	"xenpv",
176	xenpv_methods,
177	0,
178};
179
180DRIVER_MODULE(xenpv, nexus, xenpv_driver, xenpv_devclass, 0, 0);
181
182struct resource *
183xenmem_alloc(device_t dev, int *res_id, size_t size)
184{
185	device_t parent;
186
187	parent = device_get_parent(dev);
188	if (parent == NULL)
189		return (NULL);
190	return (XENMEM_ALLOC(parent, dev, res_id, size));
191}
192
193int
194xenmem_free(device_t dev, int res_id, struct resource *res)
195{
196	device_t parent;
197
198	parent = device_get_parent(dev);
199	if (parent == NULL)
200		return (ENXIO);
201	return (XENMEM_FREE(parent, dev, res_id, res));
202}
203