1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27
28 /*
29 * A simple wrapper around the balloon kernel thread to allow userland
30 * programs access to the balloon status.
31 */
32
33 #include <sys/types.h>
34 #include <sys/file.h>
35 #include <sys/errno.h>
36 #include <sys/open.h>
37 #include <sys/cred.h>
38 #include <sys/conf.h>
39 #include <sys/stat.h>
40 #include <sys/modctl.h>
41 #include <sys/ddi.h>
42 #include <sys/sunddi.h>
43 #include <sys/hypervisor.h>
44 #include <sys/sysmacros.h>
45 #include <sys/balloon_impl.h>
46
47 static dev_info_t *balloon_devi;
48
49 /*ARGSUSED*/
50 static int
51 balloon_getinfo(dev_info_t *devi, ddi_info_cmd_t cmd, void *arg, void **result)
52 {
53 if (getminor((dev_t)arg) != BALLOON_MINOR)
54 return (DDI_FAILURE);
55
56 switch (cmd) {
57 case DDI_INFO_DEVT2DEVINFO:
58 *result = balloon_devi;
59 break;
60 case DDI_INFO_DEVT2INSTANCE:
61 *result = 0;
62 break;
63 default:
64 return (DDI_FAILURE);
65 }
66
67 return (DDI_SUCCESS);
68 }
69
70 static int
71 balloon_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
72 {
73 if (cmd != DDI_ATTACH)
74 return (DDI_FAILURE);
75
76 if (ddi_create_minor_node(devi, ddi_get_name(devi), S_IFCHR,
77 ddi_get_instance(devi), DDI_PSEUDO, 0) != DDI_SUCCESS)
78 return (DDI_FAILURE);
79
80 balloon_devi = devi;
81 ddi_report_dev(devi);
82 return (DDI_SUCCESS);
83 }
84
85 static int
86 balloon_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
87 {
88 if (cmd != DDI_DETACH)
89 return (DDI_FAILURE);
90 ddi_remove_minor_node(devi, NULL);
91 balloon_devi = NULL;
92 return (DDI_SUCCESS);
93 }
94
95 /*ARGSUSED1*/
96 static int
97 balloon_open(dev_t *dev, int flag, int otyp, cred_t *cr)
98 {
99 return (getminor(*dev) == BALLOON_MINOR ? 0 : ENXIO);
100 }
101
102 /*
103 * When asked for one of the balloon values, we simply query the balloon thread.
104 */
105 /*ARGSUSED*/
106 static int
107 balloon_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *cr,
108 int *rval_p)
109 {
110 int rval = 0;
111 size_t value;
112
113 switch (cmd) {
114 case BLN_IOCTL_CURRENT:
115 case BLN_IOCTL_TARGET:
116 case BLN_IOCTL_LOW:
117 case BLN_IOCTL_HIGH:
118 case BLN_IOCTL_LIMIT:
119 value = balloon_values(cmd);
120 if (ddi_copyout((void *)&value, (void *)arg, sizeof (value),
121 mode))
122 return (EFAULT);
123 break;
124 default:
125 rval = EINVAL;
126 break;
127 }
128 return (rval);
129 }
130
131 static struct cb_ops balloon_cb_ops = {
132 balloon_open,
133 nulldev, /* close */
134 nodev, /* strategy */
135 nodev, /* print */
136 nodev, /* dump */
137 nodev, /* read */
138 nodev, /* write */
139 balloon_ioctl, /* ioctl */
140 nodev, /* devmap */
141 nodev, /* mmap */
142 nodev, /* segmap */
143 nochpoll, /* poll */
144 ddi_prop_op,
145 NULL,
146 D_64BIT | D_MP,
147 CB_REV,
148 NULL,
149 NULL
150 };
151
152 static struct dev_ops balloon_dv_ops = {
153 DEVO_REV,
154 0,
155 balloon_getinfo,
156 nulldev, /* identify */
157 nulldev, /* probe */
158 balloon_attach,
159 balloon_detach,
160 nodev, /* reset */
161 &balloon_cb_ops,
162 NULL, /* struct bus_ops */
163 NULL, /* power */
164 ddi_quiesce_not_needed, /* quiesce */
165 };
166
167 static struct modldrv modldrv = {
168 &mod_driverops,
169 "balloon driver",
170 &balloon_dv_ops
171 };
172
173 static struct modlinkage modl = {
174 MODREV_1,
175 {
176 (void *)&modldrv,
177 NULL /* null termination */
178 }
179 };
180
181 int
182 _init(void)
183 {
184 return (mod_install(&modl));
185 }
186
187 int
188 _fini(void)
189 {
190 return (mod_remove(&modl));
191 }
192
193 int
194 _info(struct modinfo *modinfo)
195 {
196 return (mod_info(&modl, modinfo));
197 }