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("$FreeBSD$");
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
67static devclass_t xenpv_devclass;
68
69static void
70xenpv_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
87static int
88xenpv_probe(device_t dev)
89{
90
91	device_set_desc(dev, "Xen PV bus");
92	return (BUS_PROBE_NOWILDCARD);
93}
94
95static int
96xenpv_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
114static struct resource *
115xenpv_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	int error;
120
121	res = bus_alloc_resource(child, SYS_RES_MEMORY, res_id, LOW_MEM_LIMIT,
122	    ~0, size, RF_ACTIVE);
123	if (res == NULL)
124		return (NULL);
125
126	phys_addr = rman_get_start(res);
127	error = vm_phys_fictitious_reg_range(phys_addr, phys_addr + size,
128	    VM_MEMATTR_DEFAULT);
129	if (error) {
130		bus_release_resource(child, SYS_RES_MEMORY, *res_id, res);
131		return (NULL);
132	}
133
134	return (res);
135}
136
137static int
138xenpv_free_physmem(device_t dev, device_t child, int res_id, struct resource *res)
139{
140	vm_paddr_t phys_addr;
141	size_t size;
142
143	phys_addr = rman_get_start(res);
144	size = rman_get_size(res);
145
146	vm_phys_fictitious_unreg_range(phys_addr, phys_addr + size);
147	return (bus_release_resource(child, SYS_RES_MEMORY, res_id, res));
148}
149
150static device_method_t xenpv_methods[] = {
151	/* Device interface */
152	DEVMETHOD(device_identify,		xenpv_identify),
153	DEVMETHOD(device_probe,			xenpv_probe),
154	DEVMETHOD(device_attach,		xenpv_attach),
155	DEVMETHOD(device_suspend,		bus_generic_suspend),
156	DEVMETHOD(device_resume,		bus_generic_resume),
157
158	/* Bus interface */
159	DEVMETHOD(bus_add_child,		bus_generic_add_child),
160	DEVMETHOD(bus_alloc_resource,		bus_generic_alloc_resource),
161	DEVMETHOD(bus_release_resource,		bus_generic_release_resource),
162	DEVMETHOD(bus_activate_resource,	bus_generic_activate_resource),
163	DEVMETHOD(bus_deactivate_resource,	bus_generic_deactivate_resource),
164
165	/* Interface to allocate memory for foreign mappings */
166	DEVMETHOD(xenmem_alloc,			xenpv_alloc_physmem),
167	DEVMETHOD(xenmem_free,			xenpv_free_physmem),
168
169	DEVMETHOD_END
170};
171
172static driver_t xenpv_driver = {
173	"xenpv",
174	xenpv_methods,
175	0,
176};
177
178DRIVER_MODULE(xenpv, nexus, xenpv_driver, xenpv_devclass, 0, 0);
179
180struct resource *
181xenmem_alloc(device_t dev, int *res_id, size_t size)
182{
183	device_t parent;
184
185	parent = device_get_parent(dev);
186	if (parent == NULL)
187		return (NULL);
188	return (XENMEM_ALLOC(parent, dev, res_id, size));
189}
190
191int
192xenmem_free(device_t dev, int res_id, struct resource *res)
193{
194	device_t parent;
195
196	parent = device_get_parent(dev);
197	if (parent == NULL)
198		return (ENXIO);
199	return (XENMEM_FREE(parent, dev, res_id, res));
200}
201