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 2007 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 #include <sys/types.h>
30 #include <sys/systm.h>
31 #include <sys/mutex.h>
32 #include <sys/time.h>
33 #include <sys/clock.h>
34 #include <sys/archsystm.h>
35 #include <sys/modctl.h>
36 #include <sys/autoconf.h>
37 #include <sys/cmn_err.h>
38 #include <sys/atomic.h>
39 #include <sys/hypervisor.h>
40
41 /*
42 * tod driver module for i86xpv
43 */
44
45 static timestruc_t
46 todxen_get(tod_ops_t *top)
47 {
48 todinfo_t tod;
49 timestruc_t ts, wcts;
50 shared_info_t *si = HYPERVISOR_shared_info;
51 uint32_t xen_wc_version;
52 hrtime_t now;
53
54 ASSERT(MUTEX_HELD(&tod_lock));
55
56 /*
57 * Pick up the wallclock base time
58 */
59 do {
60 xen_wc_version = si->wc_version;
61
62 membar_consumer();
63
64 wcts.tv_sec = si->wc_sec;
65 wcts.tv_nsec = si->wc_nsec;
66
67 membar_consumer();
68
69 } while ((si->wc_version & 1) | (xen_wc_version ^ si->wc_version));
70
71 /*
72 * Compute the TOD as the wallclock (boot) time plus time-since-boot
73 * (/not/ hrtime!) and normalize.
74 */
75 now = xpv_getsystime() +
76 (hrtime_t)wcts.tv_nsec + (hrtime_t)wcts.tv_sec * NANOSEC;
77 ts.tv_sec = (time_t)(now / NANOSEC);
78 ts.tv_nsec = (long)(now % NANOSEC);
79
80 /*
81 * Apply GMT lag correction from /etc/rtc_config to get UTC time
82 */
83 ts.tv_sec += ggmtl();
84
85 /*
86 * Validate the TOD in case of total insanity
87 */
88 tod = utc_to_tod(ts.tv_sec);
89 if (tod.tod_year < 69) {
90 static int range_warn = 1; /* warn only once */
91
92 if (range_warn) {
93 /*
94 * If we're dom0, go invoke the underlying driver; the
95 * routine should complain if it discovers something
96 * wrong.
97 */
98 if (DOMAIN_IS_INITDOMAIN(xen_info))
99 (void) TODOP_GET(top->tod_next);
100
101 /*
102 * Check the virtual hardware.
103 */
104 if (tod.tod_year > 38)
105 cmn_err(CE_WARN,
106 "hypervisor wall clock is out "
107 "of range -- time needs to be reset");
108 range_warn = 0;
109 }
110 tod.tod_year += 100;
111 ts.tv_sec = tod_to_utc(tod);
112 }
113
114 return (ts);
115 }
116
117 /*
118 * On dom0, invoke the underlying driver to update the physical RTC,
119 * and tell the hypervisor to update its idea of global time.
120 *
121 * On domU, we don't have permission to update the machine's physical RTC,
122 * so quietly ignore the attempt.
123 */
124 static void
125 todxen_set(tod_ops_t *top, timestruc_t ts)
126 {
127 xen_platform_op_t op;
128
129 if (DOMAIN_IS_INITDOMAIN(xen_info)) {
130 ASSERT(MUTEX_HELD(&tod_lock));
131 TODOP_SET(top->tod_next, ts);
132
133 op.cmd = XENPF_settime;
134 op.interface_version = XENPF_INTERFACE_VERSION;
135 op.u.settime.secs = ts.tv_sec - ggmtl();
136 op.u.settime.nsecs = ts.tv_nsec;
137 op.u.settime.system_time = xpv_getsystime();
138 (void) HYPERVISOR_platform_op(&op);
139 }
140 }
141
142 static tod_ops_t todxen_ops = {
143 TOD_OPS_VERSION,
144 todxen_get,
145 todxen_set,
146 NULL
147 };
148
149 static struct modlmisc modlmisc = {
150 &mod_miscops,
151 "TOD module for i86xpv"
152 };
153
154 static struct modlinkage modl = {
155 MODREV_1,
156 &modlmisc
157 };
158
159 int
160 _init(void)
161 {
162 /*
163 * In future we might need to do something more sophisticated
164 * for versioning, i.e. dealing with older hardware TOD modules
165 * underneath us, but for now, anything else but "same" is a
166 * fatal error.
167 */
168 if (tod_ops->tod_version != todxen_ops.tod_version)
169 panic("TOD module version mismatch");
170
171 /*
172 * Stitch the ops vector linkage together, with this module
173 * sitting on the "front" of the ops list.
174 */
175 todxen_ops.tod_next = tod_ops;
176 tod_ops = &todxen_ops;
177
178 return (mod_install(&modl));
179 }
180
181 int
182 _fini(void)
183 {
184 return (EBUSY);
185 }
186
187 int
188 _info(struct modinfo *modinfo)
189 {
190 return (mod_info(&modl, modinfo));
191 }