| @@ -1,1042 +1,1046 @@ | | | @@ -1,1042 +1,1046 @@ |
1 | /* $NetBSD: kern_tc.c,v 1.74 2023/07/27 01:48:49 riastradh Exp $ */ | | 1 | /* $NetBSD: kern_tc.c,v 1.75 2023/07/28 10:37:28 riastradh Exp $ */ |
2 | | | 2 | |
3 | /*- | | 3 | /*- |
4 | * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc. | | 4 | * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc. |
5 | * All rights reserved. | | 5 | * All rights reserved. |
6 | * | | 6 | * |
7 | * This code is derived from software contributed to The NetBSD Foundation | | 7 | * This code is derived from software contributed to The NetBSD Foundation |
8 | * by Andrew Doran. | | 8 | * by Andrew Doran. |
9 | * | | 9 | * |
10 | * Redistribution and use in source and binary forms, with or without | | 10 | * Redistribution and use in source and binary forms, with or without |
11 | * modification, are permitted provided that the following conditions | | 11 | * modification, are permitted provided that the following conditions |
12 | * are met: | | 12 | * are met: |
13 | * 1. Redistributions of source code must retain the above copyright | | 13 | * 1. Redistributions of source code must retain the above copyright |
14 | * notice, this list of conditions and the following disclaimer. | | 14 | * notice, this list of conditions and the following disclaimer. |
15 | * 2. Redistributions in binary form must reproduce the above copyright | | 15 | * 2. Redistributions in binary form must reproduce the above copyright |
16 | * notice, this list of conditions and the following disclaimer in the | | 16 | * notice, this list of conditions and the following disclaimer in the |
17 | * documentation and/or other materials provided with the distribution. | | 17 | * documentation and/or other materials provided with the distribution. |
18 | * | | 18 | * |
19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS | | 19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED | | 20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | | 21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS | | 22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | | 23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | | 24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | | 25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | | 26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | | 27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | | 28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
29 | * POSSIBILITY OF SUCH DAMAGE. | | 29 | * POSSIBILITY OF SUCH DAMAGE. |
30 | */ | | 30 | */ |
31 | | | 31 | |
32 | /*- | | 32 | /*- |
33 | * ---------------------------------------------------------------------------- | | 33 | * ---------------------------------------------------------------------------- |
34 | * "THE BEER-WARE LICENSE" (Revision 42): | | 34 | * "THE BEER-WARE LICENSE" (Revision 42): |
35 | * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you | | 35 | * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you |
36 | * can do whatever you want with this stuff. If we meet some day, and you think | | 36 | * can do whatever you want with this stuff. If we meet some day, and you think |
37 | * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp | | 37 | * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp |
38 | * --------------------------------------------------------------------------- | | 38 | * --------------------------------------------------------------------------- |
39 | */ | | 39 | */ |
40 | | | 40 | |
| | | 41 | /* |
| | | 42 | * https://papers.freebsd.org/2002/phk-timecounters.files/timecounter.pdf |
| | | 43 | */ |
| | | 44 | |
41 | #include <sys/cdefs.h> | | 45 | #include <sys/cdefs.h> |
42 | /* __FBSDID("$FreeBSD: src/sys/kern/kern_tc.c,v 1.166 2005/09/19 22:16:31 andre Exp $"); */ | | 46 | /* __FBSDID("$FreeBSD: src/sys/kern/kern_tc.c,v 1.166 2005/09/19 22:16:31 andre Exp $"); */ |
43 | __KERNEL_RCSID(0, "$NetBSD: kern_tc.c,v 1.74 2023/07/27 01:48:49 riastradh Exp $"); | | 47 | __KERNEL_RCSID(0, "$NetBSD: kern_tc.c,v 1.75 2023/07/28 10:37:28 riastradh Exp $"); |
44 | | | 48 | |
45 | #ifdef _KERNEL_OPT | | 49 | #ifdef _KERNEL_OPT |
46 | #include "opt_ntp.h" | | 50 | #include "opt_ntp.h" |
47 | #endif | | 51 | #endif |
48 | | | 52 | |
49 | #include <sys/param.h> | | 53 | #include <sys/param.h> |
50 | | | 54 | |
51 | #include <sys/atomic.h> | | 55 | #include <sys/atomic.h> |
52 | #include <sys/evcnt.h> | | 56 | #include <sys/evcnt.h> |
53 | #include <sys/kauth.h> | | 57 | #include <sys/kauth.h> |
54 | #include <sys/kernel.h> | | 58 | #include <sys/kernel.h> |
55 | #include <sys/lock.h> | | 59 | #include <sys/lock.h> |
56 | #include <sys/mutex.h> | | 60 | #include <sys/mutex.h> |
57 | #include <sys/reboot.h> /* XXX just to get AB_VERBOSE */ | | 61 | #include <sys/reboot.h> /* XXX just to get AB_VERBOSE */ |
58 | #include <sys/sysctl.h> | | 62 | #include <sys/sysctl.h> |
59 | #include <sys/syslog.h> | | 63 | #include <sys/syslog.h> |
60 | #include <sys/systm.h> | | 64 | #include <sys/systm.h> |
61 | #include <sys/timepps.h> | | 65 | #include <sys/timepps.h> |
62 | #include <sys/timetc.h> | | 66 | #include <sys/timetc.h> |
63 | #include <sys/timex.h> | | 67 | #include <sys/timex.h> |
64 | #include <sys/xcall.h> | | 68 | #include <sys/xcall.h> |
65 | | | 69 | |
66 | /* | | 70 | /* |
67 | * A large step happens on boot. This constant detects such steps. | | 71 | * A large step happens on boot. This constant detects such steps. |
68 | * It is relatively small so that ntp_update_second gets called enough | | 72 | * It is relatively small so that ntp_update_second gets called enough |
69 | * in the typical 'missed a couple of seconds' case, but doesn't loop | | 73 | * in the typical 'missed a couple of seconds' case, but doesn't loop |
70 | * forever when the time step is large. | | 74 | * forever when the time step is large. |
71 | */ | | 75 | */ |
72 | #define LARGE_STEP 200 | | 76 | #define LARGE_STEP 200 |
73 | | | 77 | |
74 | /* | | 78 | /* |
75 | * Implement a dummy timecounter which we can use until we get a real one | | 79 | * Implement a dummy timecounter which we can use until we get a real one |
76 | * in the air. This allows the console and other early stuff to use | | 80 | * in the air. This allows the console and other early stuff to use |
77 | * time services. | | 81 | * time services. |
78 | */ | | 82 | */ |
79 | | | 83 | |
80 | static u_int | | 84 | static u_int |
81 | dummy_get_timecount(struct timecounter *tc) | | 85 | dummy_get_timecount(struct timecounter *tc) |
82 | { | | 86 | { |
83 | static u_int now; | | 87 | static u_int now; |
84 | | | 88 | |
85 | return ++now; | | 89 | return ++now; |
86 | } | | 90 | } |
87 | | | 91 | |
88 | static struct timecounter dummy_timecounter = { | | 92 | static struct timecounter dummy_timecounter = { |
89 | .tc_get_timecount = dummy_get_timecount, | | 93 | .tc_get_timecount = dummy_get_timecount, |
90 | .tc_counter_mask = ~0u, | | 94 | .tc_counter_mask = ~0u, |
91 | .tc_frequency = 1000000, | | 95 | .tc_frequency = 1000000, |
92 | .tc_name = "dummy", | | 96 | .tc_name = "dummy", |
93 | .tc_quality = -1000000, | | 97 | .tc_quality = -1000000, |
94 | .tc_priv = NULL, | | 98 | .tc_priv = NULL, |
95 | }; | | 99 | }; |
96 | | | 100 | |
97 | struct timehands { | | 101 | struct timehands { |
98 | /* These fields must be initialized by the driver. */ | | 102 | /* These fields must be initialized by the driver. */ |
99 | struct timecounter *th_counter; /* active timecounter */ | | 103 | struct timecounter *th_counter; /* active timecounter */ |
100 | int64_t th_adjustment; /* frequency adjustment */ | | 104 | int64_t th_adjustment; /* frequency adjustment */ |
101 | /* (NTP/adjtime) */ | | 105 | /* (NTP/adjtime) */ |
102 | uint64_t th_scale; /* scale factor (counter */ | | 106 | uint64_t th_scale; /* scale factor (counter */ |
103 | /* tick->time) */ | | 107 | /* tick->time) */ |
104 | uint64_t th_offset_count; /* offset at last time */ | | 108 | uint64_t th_offset_count; /* offset at last time */ |
105 | /* update (tc_windup()) */ | | 109 | /* update (tc_windup()) */ |
106 | struct bintime th_offset; /* bin (up)time at windup */ | | 110 | struct bintime th_offset; /* bin (up)time at windup */ |
107 | struct timeval th_microtime; /* cached microtime */ | | 111 | struct timeval th_microtime; /* cached microtime */ |
108 | struct timespec th_nanotime; /* cached nanotime */ | | 112 | struct timespec th_nanotime; /* cached nanotime */ |
109 | /* Fields not to be copied in tc_windup start with th_generation. */ | | 113 | /* Fields not to be copied in tc_windup start with th_generation. */ |
110 | volatile u_int th_generation; /* current genration */ | | 114 | volatile u_int th_generation; /* current genration */ |
111 | struct timehands *th_next; /* next timehand */ | | 115 | struct timehands *th_next; /* next timehand */ |
112 | }; | | 116 | }; |
113 | | | 117 | |
114 | static struct timehands th0; | | 118 | static struct timehands th0; |
115 | static struct timehands th9 = { .th_next = &th0, }; | | 119 | static struct timehands th9 = { .th_next = &th0, }; |
116 | static struct timehands th8 = { .th_next = &th9, }; | | 120 | static struct timehands th8 = { .th_next = &th9, }; |
117 | static struct timehands th7 = { .th_next = &th8, }; | | 121 | static struct timehands th7 = { .th_next = &th8, }; |
118 | static struct timehands th6 = { .th_next = &th7, }; | | 122 | static struct timehands th6 = { .th_next = &th7, }; |
119 | static struct timehands th5 = { .th_next = &th6, }; | | 123 | static struct timehands th5 = { .th_next = &th6, }; |
120 | static struct timehands th4 = { .th_next = &th5, }; | | 124 | static struct timehands th4 = { .th_next = &th5, }; |
121 | static struct timehands th3 = { .th_next = &th4, }; | | 125 | static struct timehands th3 = { .th_next = &th4, }; |
122 | static struct timehands th2 = { .th_next = &th3, }; | | 126 | static struct timehands th2 = { .th_next = &th3, }; |
123 | static struct timehands th1 = { .th_next = &th2, }; | | 127 | static struct timehands th1 = { .th_next = &th2, }; |
124 | static struct timehands th0 = { | | 128 | static struct timehands th0 = { |
125 | .th_counter = &dummy_timecounter, | | 129 | .th_counter = &dummy_timecounter, |
126 | .th_scale = (uint64_t)-1 / 1000000, | | 130 | .th_scale = (uint64_t)-1 / 1000000, |
127 | .th_offset = { .sec = 1, .frac = 0 }, | | 131 | .th_offset = { .sec = 1, .frac = 0 }, |
128 | .th_generation = 1, | | 132 | .th_generation = 1, |
129 | .th_next = &th1, | | 133 | .th_next = &th1, |
130 | }; | | 134 | }; |
131 | | | 135 | |
132 | static struct timehands *volatile timehands = &th0; | | 136 | static struct timehands *volatile timehands = &th0; |
133 | struct timecounter *timecounter = &dummy_timecounter; | | 137 | struct timecounter *timecounter = &dummy_timecounter; |
134 | static struct timecounter *timecounters = &dummy_timecounter; | | 138 | static struct timecounter *timecounters = &dummy_timecounter; |
135 | | | 139 | |
136 | /* used by savecore(8) */ | | 140 | /* used by savecore(8) */ |
137 | time_t time_second_legacy asm("time_second"); | | 141 | time_t time_second_legacy asm("time_second"); |
138 | | | 142 | |
139 | #ifdef __HAVE_ATOMIC64_LOADSTORE | | 143 | #ifdef __HAVE_ATOMIC64_LOADSTORE |
140 | volatile time_t time__second __cacheline_aligned = 1; | | 144 | volatile time_t time__second __cacheline_aligned = 1; |
141 | volatile time_t time__uptime __cacheline_aligned = 1; | | 145 | volatile time_t time__uptime __cacheline_aligned = 1; |
142 | #else | | 146 | #else |
143 | static volatile struct { | | 147 | static volatile struct { |
144 | uint32_t lo, hi; | | 148 | uint32_t lo, hi; |
145 | } time__uptime32 __cacheline_aligned = { | | 149 | } time__uptime32 __cacheline_aligned = { |
146 | .lo = 1, | | 150 | .lo = 1, |
147 | }, time__second32 __cacheline_aligned = { | | 151 | }, time__second32 __cacheline_aligned = { |
148 | .lo = 1, | | 152 | .lo = 1, |
149 | }; | | 153 | }; |
150 | #endif | | 154 | #endif |
151 | | | 155 | |
152 | static struct { | | 156 | static struct { |
153 | struct bintime bin; | | 157 | struct bintime bin; |
154 | volatile unsigned gen; /* even when stable, odd when changing */ | | 158 | volatile unsigned gen; /* even when stable, odd when changing */ |
155 | } timebase __cacheline_aligned; | | 159 | } timebase __cacheline_aligned; |
156 | | | 160 | |
157 | static int timestepwarnings; | | 161 | static int timestepwarnings; |
158 | | | 162 | |
159 | kmutex_t timecounter_lock; | | 163 | kmutex_t timecounter_lock; |
160 | static u_int timecounter_mods; | | 164 | static u_int timecounter_mods; |
161 | static volatile int timecounter_removals = 1; | | 165 | static volatile int timecounter_removals = 1; |
162 | static u_int timecounter_bad; | | 166 | static u_int timecounter_bad; |
163 | | | 167 | |
164 | #ifdef __HAVE_ATOMIC64_LOADSTORE | | 168 | #ifdef __HAVE_ATOMIC64_LOADSTORE |
165 | | | 169 | |
166 | static inline void | | 170 | static inline void |
167 | setrealuptime(time_t second, time_t uptime) | | 171 | setrealuptime(time_t second, time_t uptime) |
168 | { | | 172 | { |
169 | | | 173 | |
170 | time_second_legacy = second; | | 174 | time_second_legacy = second; |
171 | | | 175 | |
172 | atomic_store_relaxed(&time__second, second); | | 176 | atomic_store_relaxed(&time__second, second); |
173 | atomic_store_relaxed(&time__uptime, uptime); | | 177 | atomic_store_relaxed(&time__uptime, uptime); |
174 | } | | 178 | } |
175 | | | 179 | |
176 | #else | | 180 | #else |
177 | | | 181 | |
178 | static inline void | | 182 | static inline void |
179 | setrealuptime(time_t second, time_t uptime) | | 183 | setrealuptime(time_t second, time_t uptime) |
180 | { | | 184 | { |
181 | uint32_t seclo = second & 0xffffffff, sechi = second >> 32; | | 185 | uint32_t seclo = second & 0xffffffff, sechi = second >> 32; |
182 | uint32_t uplo = uptime & 0xffffffff, uphi = uptime >> 32; | | 186 | uint32_t uplo = uptime & 0xffffffff, uphi = uptime >> 32; |
183 | | | 187 | |
184 | KDASSERT(mutex_owned(&timecounter_lock)); | | 188 | KDASSERT(mutex_owned(&timecounter_lock)); |
185 | | | 189 | |
186 | time_second_legacy = second; | | 190 | time_second_legacy = second; |
187 | | | 191 | |
188 | /* | | 192 | /* |
189 | * Fast path -- no wraparound, just updating the low bits, so | | 193 | * Fast path -- no wraparound, just updating the low bits, so |
190 | * no need for seqlocked access. | | 194 | * no need for seqlocked access. |
191 | */ | | 195 | */ |
192 | if (__predict_true(sechi == time__second32.hi) && | | 196 | if (__predict_true(sechi == time__second32.hi) && |
193 | __predict_true(uphi == time__uptime32.hi)) { | | 197 | __predict_true(uphi == time__uptime32.hi)) { |
194 | atomic_store_relaxed(&time__second32.lo, seclo); | | 198 | atomic_store_relaxed(&time__second32.lo, seclo); |
195 | atomic_store_relaxed(&time__uptime32.lo, uplo); | | 199 | atomic_store_relaxed(&time__uptime32.lo, uplo); |
196 | return; | | 200 | return; |
197 | } | | 201 | } |
198 | | | 202 | |
199 | atomic_store_relaxed(&time__second32.hi, 0xffffffff); | | 203 | atomic_store_relaxed(&time__second32.hi, 0xffffffff); |
200 | atomic_store_relaxed(&time__uptime32.hi, 0xffffffff); | | 204 | atomic_store_relaxed(&time__uptime32.hi, 0xffffffff); |
201 | membar_producer(); | | 205 | membar_producer(); |
202 | atomic_store_relaxed(&time__second32.lo, seclo); | | 206 | atomic_store_relaxed(&time__second32.lo, seclo); |
203 | atomic_store_relaxed(&time__uptime32.lo, uplo); | | 207 | atomic_store_relaxed(&time__uptime32.lo, uplo); |
204 | membar_producer(); | | 208 | membar_producer(); |
205 | atomic_store_relaxed(&time__second32.hi, sechi); | | 209 | atomic_store_relaxed(&time__second32.hi, sechi); |
206 | atomic_store_relaxed(&time__uptime32.hi, uphi); | | 210 | atomic_store_relaxed(&time__uptime32.hi, uphi); |
207 | } | | 211 | } |
208 | | | 212 | |
209 | time_t | | 213 | time_t |
210 | getrealtime(void) | | 214 | getrealtime(void) |
211 | { | | 215 | { |
212 | uint32_t lo, hi; | | 216 | uint32_t lo, hi; |
213 | | | 217 | |
214 | do { | | 218 | do { |
215 | for (;;) { | | 219 | for (;;) { |
216 | hi = atomic_load_relaxed(&time__second32.hi); | | 220 | hi = atomic_load_relaxed(&time__second32.hi); |
217 | if (__predict_true(hi != 0xffffffff)) | | 221 | if (__predict_true(hi != 0xffffffff)) |
218 | break; | | 222 | break; |
219 | SPINLOCK_BACKOFF_HOOK; | | 223 | SPINLOCK_BACKOFF_HOOK; |
220 | } | | 224 | } |
221 | membar_consumer(); | | 225 | membar_consumer(); |
222 | lo = atomic_load_relaxed(&time__second32.lo); | | 226 | lo = atomic_load_relaxed(&time__second32.lo); |
223 | membar_consumer(); | | 227 | membar_consumer(); |
224 | } while (hi != atomic_load_relaxed(&time__second32.hi)); | | 228 | } while (hi != atomic_load_relaxed(&time__second32.hi)); |
225 | | | 229 | |
226 | return ((time_t)hi << 32) | lo; | | 230 | return ((time_t)hi << 32) | lo; |
227 | } | | 231 | } |
228 | | | 232 | |
229 | time_t | | 233 | time_t |
230 | getuptime(void) | | 234 | getuptime(void) |
231 | { | | 235 | { |
232 | uint32_t lo, hi; | | 236 | uint32_t lo, hi; |
233 | | | 237 | |
234 | do { | | 238 | do { |
235 | for (;;) { | | 239 | for (;;) { |
236 | hi = atomic_load_relaxed(&time__uptime32.hi); | | 240 | hi = atomic_load_relaxed(&time__uptime32.hi); |
237 | if (__predict_true(hi != 0xffffffff)) | | 241 | if (__predict_true(hi != 0xffffffff)) |
238 | break; | | 242 | break; |
239 | SPINLOCK_BACKOFF_HOOK; | | 243 | SPINLOCK_BACKOFF_HOOK; |
240 | } | | 244 | } |
241 | membar_consumer(); | | 245 | membar_consumer(); |
242 | lo = atomic_load_relaxed(&time__uptime32.lo); | | 246 | lo = atomic_load_relaxed(&time__uptime32.lo); |
243 | membar_consumer(); | | 247 | membar_consumer(); |
244 | } while (hi != atomic_load_relaxed(&time__uptime32.hi)); | | 248 | } while (hi != atomic_load_relaxed(&time__uptime32.hi)); |
245 | | | 249 | |
246 | return ((time_t)hi << 32) | lo; | | 250 | return ((time_t)hi << 32) | lo; |
247 | } | | 251 | } |
248 | | | 252 | |
249 | time_t | | 253 | time_t |
250 | getboottime(void) | | 254 | getboottime(void) |
251 | { | | 255 | { |
252 | | | 256 | |
253 | return getrealtime() - getuptime(); | | 257 | return getrealtime() - getuptime(); |
254 | } | | 258 | } |
255 | | | 259 | |
256 | uint32_t | | 260 | uint32_t |
257 | getuptime32(void) | | 261 | getuptime32(void) |
258 | { | | 262 | { |
259 | | | 263 | |
260 | return atomic_load_relaxed(&time__uptime32.lo); | | 264 | return atomic_load_relaxed(&time__uptime32.lo); |
261 | } | | 265 | } |
262 | | | 266 | |
263 | #endif /* !defined(__HAVE_ATOMIC64_LOADSTORE) */ | | 267 | #endif /* !defined(__HAVE_ATOMIC64_LOADSTORE) */ |
264 | | | 268 | |
265 | /* | | 269 | /* |
266 | * sysctl helper routine for kern.timercounter.hardware | | 270 | * sysctl helper routine for kern.timercounter.hardware |
267 | */ | | 271 | */ |
268 | static int | | 272 | static int |
269 | sysctl_kern_timecounter_hardware(SYSCTLFN_ARGS) | | 273 | sysctl_kern_timecounter_hardware(SYSCTLFN_ARGS) |
270 | { | | 274 | { |
271 | struct sysctlnode node; | | 275 | struct sysctlnode node; |
272 | int error; | | 276 | int error; |
273 | char newname[MAX_TCNAMELEN]; | | 277 | char newname[MAX_TCNAMELEN]; |
274 | struct timecounter *newtc, *tc; | | 278 | struct timecounter *newtc, *tc; |
275 | | | 279 | |
276 | tc = timecounter; | | 280 | tc = timecounter; |
277 | | | 281 | |
278 | strlcpy(newname, tc->tc_name, sizeof(newname)); | | 282 | strlcpy(newname, tc->tc_name, sizeof(newname)); |
279 | | | 283 | |
280 | node = *rnode; | | 284 | node = *rnode; |
281 | node.sysctl_data = newname; | | 285 | node.sysctl_data = newname; |
282 | node.sysctl_size = sizeof(newname); | | 286 | node.sysctl_size = sizeof(newname); |
283 | | | 287 | |
284 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); | | 288 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); |
285 | | | 289 | |
286 | if (error || | | 290 | if (error || |
287 | newp == NULL || | | 291 | newp == NULL || |
288 | strncmp(newname, tc->tc_name, sizeof(newname)) == 0) | | 292 | strncmp(newname, tc->tc_name, sizeof(newname)) == 0) |
289 | return error; | | 293 | return error; |
290 | | | 294 | |
291 | if (l != NULL && (error = kauth_authorize_system(l->l_cred, | | 295 | if (l != NULL && (error = kauth_authorize_system(l->l_cred, |
292 | KAUTH_SYSTEM_TIME, KAUTH_REQ_SYSTEM_TIME_TIMECOUNTERS, newname, | | 296 | KAUTH_SYSTEM_TIME, KAUTH_REQ_SYSTEM_TIME_TIMECOUNTERS, newname, |
293 | NULL, NULL)) != 0) | | 297 | NULL, NULL)) != 0) |
294 | return error; | | 298 | return error; |
295 | | | 299 | |
296 | if (!cold) | | 300 | if (!cold) |
297 | mutex_spin_enter(&timecounter_lock); | | 301 | mutex_spin_enter(&timecounter_lock); |
298 | error = EINVAL; | | 302 | error = EINVAL; |
299 | for (newtc = timecounters; newtc != NULL; newtc = newtc->tc_next) { | | 303 | for (newtc = timecounters; newtc != NULL; newtc = newtc->tc_next) { |
300 | if (strcmp(newname, newtc->tc_name) != 0) | | 304 | if (strcmp(newname, newtc->tc_name) != 0) |
301 | continue; | | 305 | continue; |
302 | /* Warm up new timecounter. */ | | 306 | /* Warm up new timecounter. */ |
303 | (void)newtc->tc_get_timecount(newtc); | | 307 | (void)newtc->tc_get_timecount(newtc); |
304 | (void)newtc->tc_get_timecount(newtc); | | 308 | (void)newtc->tc_get_timecount(newtc); |
305 | timecounter = newtc; | | 309 | timecounter = newtc; |
306 | error = 0; | | 310 | error = 0; |
307 | break; | | 311 | break; |
308 | } | | 312 | } |
309 | if (!cold) | | 313 | if (!cold) |
310 | mutex_spin_exit(&timecounter_lock); | | 314 | mutex_spin_exit(&timecounter_lock); |
311 | return error; | | 315 | return error; |
312 | } | | 316 | } |
313 | | | 317 | |
314 | static int | | 318 | static int |
315 | sysctl_kern_timecounter_choice(SYSCTLFN_ARGS) | | 319 | sysctl_kern_timecounter_choice(SYSCTLFN_ARGS) |
316 | { | | 320 | { |
317 | char buf[MAX_TCNAMELEN+48]; | | 321 | char buf[MAX_TCNAMELEN+48]; |
318 | char *where; | | 322 | char *where; |
319 | const char *spc; | | 323 | const char *spc; |
320 | struct timecounter *tc; | | 324 | struct timecounter *tc; |
321 | size_t needed, left, slen; | | 325 | size_t needed, left, slen; |
322 | int error, mods; | | 326 | int error, mods; |
323 | | | 327 | |
324 | if (newp != NULL) | | 328 | if (newp != NULL) |
325 | return EPERM; | | 329 | return EPERM; |
326 | if (namelen != 0) | | 330 | if (namelen != 0) |
327 | return EINVAL; | | 331 | return EINVAL; |
328 | | | 332 | |
329 | mutex_spin_enter(&timecounter_lock); | | 333 | mutex_spin_enter(&timecounter_lock); |
330 | retry: | | 334 | retry: |
331 | spc = ""; | | 335 | spc = ""; |
332 | error = 0; | | 336 | error = 0; |
333 | needed = 0; | | 337 | needed = 0; |
334 | left = *oldlenp; | | 338 | left = *oldlenp; |
335 | where = oldp; | | 339 | where = oldp; |
336 | for (tc = timecounters; error == 0 && tc != NULL; tc = tc->tc_next) { | | 340 | for (tc = timecounters; error == 0 && tc != NULL; tc = tc->tc_next) { |
337 | if (where == NULL) { | | 341 | if (where == NULL) { |
338 | needed += sizeof(buf); /* be conservative */ | | 342 | needed += sizeof(buf); /* be conservative */ |
339 | } else { | | 343 | } else { |
340 | slen = snprintf(buf, sizeof(buf), "%s%s(q=%d, f=%" PRId64 | | 344 | slen = snprintf(buf, sizeof(buf), "%s%s(q=%d, f=%" PRId64 |
341 | " Hz)", spc, tc->tc_name, tc->tc_quality, | | 345 | " Hz)", spc, tc->tc_name, tc->tc_quality, |
342 | tc->tc_frequency); | | 346 | tc->tc_frequency); |
343 | if (left < slen + 1) | | 347 | if (left < slen + 1) |
344 | break; | | 348 | break; |
345 | mods = timecounter_mods; | | 349 | mods = timecounter_mods; |
346 | mutex_spin_exit(&timecounter_lock); | | 350 | mutex_spin_exit(&timecounter_lock); |
347 | error = copyout(buf, where, slen + 1); | | 351 | error = copyout(buf, where, slen + 1); |
348 | mutex_spin_enter(&timecounter_lock); | | 352 | mutex_spin_enter(&timecounter_lock); |
349 | if (mods != timecounter_mods) { | | 353 | if (mods != timecounter_mods) { |
350 | goto retry; | | 354 | goto retry; |
351 | } | | 355 | } |
352 | spc = " "; | | 356 | spc = " "; |
353 | where += slen; | | 357 | where += slen; |
354 | needed += slen; | | 358 | needed += slen; |
355 | left -= slen; | | 359 | left -= slen; |
356 | } | | 360 | } |
357 | } | | 361 | } |
358 | mutex_spin_exit(&timecounter_lock); | | 362 | mutex_spin_exit(&timecounter_lock); |
359 | | | 363 | |
360 | *oldlenp = needed; | | 364 | *oldlenp = needed; |
361 | return error; | | 365 | return error; |
362 | } | | 366 | } |
363 | | | 367 | |
364 | SYSCTL_SETUP(sysctl_timecounter_setup, "sysctl timecounter setup") | | 368 | SYSCTL_SETUP(sysctl_timecounter_setup, "sysctl timecounter setup") |
365 | { | | 369 | { |
366 | const struct sysctlnode *node; | | 370 | const struct sysctlnode *node; |
367 | | | 371 | |
368 | sysctl_createv(clog, 0, NULL, &node, | | 372 | sysctl_createv(clog, 0, NULL, &node, |
369 | CTLFLAG_PERMANENT, | | 373 | CTLFLAG_PERMANENT, |
370 | CTLTYPE_NODE, "timecounter", | | 374 | CTLTYPE_NODE, "timecounter", |
371 | SYSCTL_DESCR("time counter information"), | | 375 | SYSCTL_DESCR("time counter information"), |
372 | NULL, 0, NULL, 0, | | 376 | NULL, 0, NULL, 0, |
373 | CTL_KERN, CTL_CREATE, CTL_EOL); | | 377 | CTL_KERN, CTL_CREATE, CTL_EOL); |
374 | | | 378 | |
375 | if (node != NULL) { | | 379 | if (node != NULL) { |
376 | sysctl_createv(clog, 0, NULL, NULL, | | 380 | sysctl_createv(clog, 0, NULL, NULL, |
377 | CTLFLAG_PERMANENT, | | 381 | CTLFLAG_PERMANENT, |
378 | CTLTYPE_STRING, "choice", | | 382 | CTLTYPE_STRING, "choice", |
379 | SYSCTL_DESCR("available counters"), | | 383 | SYSCTL_DESCR("available counters"), |
380 | sysctl_kern_timecounter_choice, 0, NULL, 0, | | 384 | sysctl_kern_timecounter_choice, 0, NULL, 0, |
381 | CTL_KERN, node->sysctl_num, CTL_CREATE, CTL_EOL); | | 385 | CTL_KERN, node->sysctl_num, CTL_CREATE, CTL_EOL); |
382 | | | 386 | |
383 | sysctl_createv(clog, 0, NULL, NULL, | | 387 | sysctl_createv(clog, 0, NULL, NULL, |
384 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, | | 388 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
385 | CTLTYPE_STRING, "hardware", | | 389 | CTLTYPE_STRING, "hardware", |
386 | SYSCTL_DESCR("currently active time counter"), | | 390 | SYSCTL_DESCR("currently active time counter"), |
387 | sysctl_kern_timecounter_hardware, 0, NULL, MAX_TCNAMELEN, | | 391 | sysctl_kern_timecounter_hardware, 0, NULL, MAX_TCNAMELEN, |
388 | CTL_KERN, node->sysctl_num, CTL_CREATE, CTL_EOL); | | 392 | CTL_KERN, node->sysctl_num, CTL_CREATE, CTL_EOL); |
389 | | | 393 | |
390 | sysctl_createv(clog, 0, NULL, NULL, | | 394 | sysctl_createv(clog, 0, NULL, NULL, |
391 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, | | 395 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
392 | CTLTYPE_INT, "timestepwarnings", | | 396 | CTLTYPE_INT, "timestepwarnings", |
393 | SYSCTL_DESCR("log time steps"), | | 397 | SYSCTL_DESCR("log time steps"), |
394 | NULL, 0, ×tepwarnings, 0, | | 398 | NULL, 0, ×tepwarnings, 0, |
395 | CTL_KERN, node->sysctl_num, CTL_CREATE, CTL_EOL); | | 399 | CTL_KERN, node->sysctl_num, CTL_CREATE, CTL_EOL); |
396 | } | | 400 | } |
397 | } | | 401 | } |
398 | | | 402 | |
399 | #ifdef TC_COUNTERS | | 403 | #ifdef TC_COUNTERS |
400 | #define TC_STATS(name) \ | | 404 | #define TC_STATS(name) \ |
401 | static struct evcnt n##name = \ | | 405 | static struct evcnt n##name = \ |
402 | EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, "timecounter", #name); \ | | 406 | EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, "timecounter", #name); \ |
403 | EVCNT_ATTACH_STATIC(n##name) | | 407 | EVCNT_ATTACH_STATIC(n##name) |
404 | TC_STATS(binuptime); TC_STATS(nanouptime); TC_STATS(microuptime); | | 408 | TC_STATS(binuptime); TC_STATS(nanouptime); TC_STATS(microuptime); |
405 | TC_STATS(bintime); TC_STATS(nanotime); TC_STATS(microtime); | | 409 | TC_STATS(bintime); TC_STATS(nanotime); TC_STATS(microtime); |
406 | TC_STATS(getbinuptime); TC_STATS(getnanouptime); TC_STATS(getmicrouptime); | | 410 | TC_STATS(getbinuptime); TC_STATS(getnanouptime); TC_STATS(getmicrouptime); |
407 | TC_STATS(getbintime); TC_STATS(getnanotime); TC_STATS(getmicrotime); | | 411 | TC_STATS(getbintime); TC_STATS(getnanotime); TC_STATS(getmicrotime); |
408 | TC_STATS(setclock); | | 412 | TC_STATS(setclock); |
409 | #define TC_COUNT(var) var.ev_count++ | | 413 | #define TC_COUNT(var) var.ev_count++ |
410 | #undef TC_STATS | | 414 | #undef TC_STATS |
411 | #else | | 415 | #else |
412 | #define TC_COUNT(var) /* nothing */ | | 416 | #define TC_COUNT(var) /* nothing */ |
413 | #endif /* TC_COUNTERS */ | | 417 | #endif /* TC_COUNTERS */ |
414 | | | 418 | |
415 | static void tc_windup(void); | | 419 | static void tc_windup(void); |
416 | | | 420 | |
417 | /* | | 421 | /* |
418 | * Return the difference between the timehands' counter value now and what | | 422 | * Return the difference between the timehands' counter value now and what |
419 | * was when we copied it to the timehands' offset_count. | | 423 | * was when we copied it to the timehands' offset_count. |
420 | */ | | 424 | */ |
421 | static inline u_int | | 425 | static inline u_int |
422 | tc_delta(struct timehands *th) | | 426 | tc_delta(struct timehands *th) |
423 | { | | 427 | { |
424 | struct timecounter *tc; | | 428 | struct timecounter *tc; |
425 | | | 429 | |
426 | tc = th->th_counter; | | 430 | tc = th->th_counter; |
427 | return (tc->tc_get_timecount(tc) - | | 431 | return (tc->tc_get_timecount(tc) - |
428 | th->th_offset_count) & tc->tc_counter_mask; | | 432 | th->th_offset_count) & tc->tc_counter_mask; |
429 | } | | 433 | } |
430 | | | 434 | |
431 | /* | | 435 | /* |
432 | * Functions for reading the time. We have to loop until we are sure that | | 436 | * Functions for reading the time. We have to loop until we are sure that |
433 | * the timehands that we operated on was not updated under our feet. See | | 437 | * the timehands that we operated on was not updated under our feet. See |
434 | * the comment in <sys/timevar.h> for a description of these 12 functions. | | 438 | * the comment in <sys/timevar.h> for a description of these 12 functions. |
435 | */ | | 439 | */ |
436 | | | 440 | |
437 | void | | 441 | void |
438 | binuptime(struct bintime *bt) | | 442 | binuptime(struct bintime *bt) |
439 | { | | 443 | { |
440 | struct timehands *th; | | 444 | struct timehands *th; |
441 | lwp_t *l; | | 445 | lwp_t *l; |
442 | u_int lgen, gen; | | 446 | u_int lgen, gen; |
443 | | | 447 | |
444 | TC_COUNT(nbinuptime); | | 448 | TC_COUNT(nbinuptime); |
445 | | | 449 | |
446 | /* | | 450 | /* |
447 | * Provide exclusion against tc_detach(). | | 451 | * Provide exclusion against tc_detach(). |
448 | * | | 452 | * |
449 | * We record the number of timecounter removals before accessing | | 453 | * We record the number of timecounter removals before accessing |
450 | * timecounter state. Note that the LWP can be using multiple | | 454 | * timecounter state. Note that the LWP can be using multiple |
451 | * "generations" at once, due to interrupts (interrupted while in | | 455 | * "generations" at once, due to interrupts (interrupted while in |
452 | * this function). Hardware interrupts will borrow the interrupted | | 456 | * this function). Hardware interrupts will borrow the interrupted |
453 | * LWP's l_tcgen value for this purpose, and can themselves be | | 457 | * LWP's l_tcgen value for this purpose, and can themselves be |
454 | * interrupted by higher priority interrupts. In this case we need | | 458 | * interrupted by higher priority interrupts. In this case we need |
455 | * to ensure that the oldest generation in use is recorded. | | 459 | * to ensure that the oldest generation in use is recorded. |
456 | * | | 460 | * |
457 | * splsched() is too expensive to use, so we take care to structure | | 461 | * splsched() is too expensive to use, so we take care to structure |
458 | * this code in such a way that it is not required. Likewise, we | | 462 | * this code in such a way that it is not required. Likewise, we |
459 | * do not disable preemption. | | 463 | * do not disable preemption. |
460 | * | | 464 | * |
461 | * Memory barriers are also too expensive to use for such a | | 465 | * Memory barriers are also too expensive to use for such a |
462 | * performance critical function. The good news is that we do not | | 466 | * performance critical function. The good news is that we do not |
463 | * need memory barriers for this type of exclusion, as the thread | | 467 | * need memory barriers for this type of exclusion, as the thread |
464 | * updating timecounter_removals will issue a broadcast cross call | | 468 | * updating timecounter_removals will issue a broadcast cross call |
465 | * before inspecting our l_tcgen value (this elides memory ordering | | 469 | * before inspecting our l_tcgen value (this elides memory ordering |
466 | * issues). | | 470 | * issues). |
467 | * | | 471 | * |
468 | * XXX If the author of the above comment knows how to make it | | 472 | * XXX If the author of the above comment knows how to make it |
469 | * safe to avoid memory barriers around the access to | | 473 | * safe to avoid memory barriers around the access to |
470 | * th->th_generation, I'm all ears. | | 474 | * th->th_generation, I'm all ears. |
471 | */ | | 475 | */ |
472 | l = curlwp; | | 476 | l = curlwp; |
473 | lgen = l->l_tcgen; | | 477 | lgen = l->l_tcgen; |
474 | if (__predict_true(lgen == 0)) { | | 478 | if (__predict_true(lgen == 0)) { |
475 | l->l_tcgen = timecounter_removals; | | 479 | l->l_tcgen = timecounter_removals; |
476 | } | | 480 | } |
477 | __insn_barrier(); | | 481 | __insn_barrier(); |
478 | | | 482 | |
479 | do { | | 483 | do { |
480 | th = atomic_load_consume(&timehands); | | 484 | th = atomic_load_consume(&timehands); |
481 | gen = th->th_generation; | | 485 | gen = th->th_generation; |
482 | membar_consumer(); | | 486 | membar_consumer(); |
483 | *bt = th->th_offset; | | 487 | *bt = th->th_offset; |
484 | bintime_addx(bt, th->th_scale * tc_delta(th)); | | 488 | bintime_addx(bt, th->th_scale * tc_delta(th)); |
485 | membar_consumer(); | | 489 | membar_consumer(); |
486 | } while (gen == 0 || gen != th->th_generation); | | 490 | } while (gen == 0 || gen != th->th_generation); |
487 | | | 491 | |
488 | __insn_barrier(); | | 492 | __insn_barrier(); |
489 | l->l_tcgen = lgen; | | 493 | l->l_tcgen = lgen; |
490 | } | | 494 | } |
491 | | | 495 | |
492 | void | | 496 | void |
493 | nanouptime(struct timespec *tsp) | | 497 | nanouptime(struct timespec *tsp) |
494 | { | | 498 | { |
495 | struct bintime bt; | | 499 | struct bintime bt; |
496 | | | 500 | |
497 | TC_COUNT(nnanouptime); | | 501 | TC_COUNT(nnanouptime); |
498 | binuptime(&bt); | | 502 | binuptime(&bt); |
499 | bintime2timespec(&bt, tsp); | | 503 | bintime2timespec(&bt, tsp); |
500 | } | | 504 | } |
501 | | | 505 | |
502 | void | | 506 | void |
503 | microuptime(struct timeval *tvp) | | 507 | microuptime(struct timeval *tvp) |
504 | { | | 508 | { |
505 | struct bintime bt; | | 509 | struct bintime bt; |
506 | | | 510 | |
507 | TC_COUNT(nmicrouptime); | | 511 | TC_COUNT(nmicrouptime); |
508 | binuptime(&bt); | | 512 | binuptime(&bt); |
509 | bintime2timeval(&bt, tvp); | | 513 | bintime2timeval(&bt, tvp); |
510 | } | | 514 | } |
511 | | | 515 | |
512 | void | | 516 | void |
513 | bintime(struct bintime *bt) | | 517 | bintime(struct bintime *bt) |
514 | { | | 518 | { |
515 | struct bintime boottime; | | 519 | struct bintime boottime; |
516 | | | 520 | |
517 | TC_COUNT(nbintime); | | 521 | TC_COUNT(nbintime); |
518 | binuptime(bt); | | 522 | binuptime(bt); |
519 | getbinboottime(&boottime); | | 523 | getbinboottime(&boottime); |
520 | bintime_add(bt, &boottime); | | 524 | bintime_add(bt, &boottime); |
521 | } | | 525 | } |
522 | | | 526 | |
523 | void | | 527 | void |
524 | nanotime(struct timespec *tsp) | | 528 | nanotime(struct timespec *tsp) |
525 | { | | 529 | { |
526 | struct bintime bt; | | 530 | struct bintime bt; |
527 | | | 531 | |
528 | TC_COUNT(nnanotime); | | 532 | TC_COUNT(nnanotime); |
529 | bintime(&bt); | | 533 | bintime(&bt); |
530 | bintime2timespec(&bt, tsp); | | 534 | bintime2timespec(&bt, tsp); |
531 | } | | 535 | } |
532 | | | 536 | |
533 | void | | 537 | void |
534 | microtime(struct timeval *tvp) | | 538 | microtime(struct timeval *tvp) |
535 | { | | 539 | { |
536 | struct bintime bt; | | 540 | struct bintime bt; |
537 | | | 541 | |
538 | TC_COUNT(nmicrotime); | | 542 | TC_COUNT(nmicrotime); |
539 | bintime(&bt); | | 543 | bintime(&bt); |
540 | bintime2timeval(&bt, tvp); | | 544 | bintime2timeval(&bt, tvp); |
541 | } | | 545 | } |
542 | | | 546 | |
543 | void | | 547 | void |
544 | getbinuptime(struct bintime *bt) | | 548 | getbinuptime(struct bintime *bt) |
545 | { | | 549 | { |
546 | struct timehands *th; | | 550 | struct timehands *th; |
547 | u_int gen; | | 551 | u_int gen; |
548 | | | 552 | |
549 | TC_COUNT(ngetbinuptime); | | 553 | TC_COUNT(ngetbinuptime); |
550 | do { | | 554 | do { |
551 | th = atomic_load_consume(&timehands); | | 555 | th = atomic_load_consume(&timehands); |
552 | gen = th->th_generation; | | 556 | gen = th->th_generation; |
553 | membar_consumer(); | | 557 | membar_consumer(); |
554 | *bt = th->th_offset; | | 558 | *bt = th->th_offset; |
555 | membar_consumer(); | | 559 | membar_consumer(); |
556 | } while (gen == 0 || gen != th->th_generation); | | 560 | } while (gen == 0 || gen != th->th_generation); |
557 | } | | 561 | } |
558 | | | 562 | |
559 | void | | 563 | void |
560 | getnanouptime(struct timespec *tsp) | | 564 | getnanouptime(struct timespec *tsp) |
561 | { | | 565 | { |
562 | struct timehands *th; | | 566 | struct timehands *th; |
563 | u_int gen; | | 567 | u_int gen; |
564 | | | 568 | |
565 | TC_COUNT(ngetnanouptime); | | 569 | TC_COUNT(ngetnanouptime); |
566 | do { | | 570 | do { |
567 | th = atomic_load_consume(&timehands); | | 571 | th = atomic_load_consume(&timehands); |
568 | gen = th->th_generation; | | 572 | gen = th->th_generation; |
569 | membar_consumer(); | | 573 | membar_consumer(); |
570 | bintime2timespec(&th->th_offset, tsp); | | 574 | bintime2timespec(&th->th_offset, tsp); |
571 | membar_consumer(); | | 575 | membar_consumer(); |
572 | } while (gen == 0 || gen != th->th_generation); | | 576 | } while (gen == 0 || gen != th->th_generation); |
573 | } | | 577 | } |
574 | | | 578 | |
575 | void | | 579 | void |
576 | getmicrouptime(struct timeval *tvp) | | 580 | getmicrouptime(struct timeval *tvp) |
577 | { | | 581 | { |
578 | struct timehands *th; | | 582 | struct timehands *th; |
579 | u_int gen; | | 583 | u_int gen; |
580 | | | 584 | |
581 | TC_COUNT(ngetmicrouptime); | | 585 | TC_COUNT(ngetmicrouptime); |
582 | do { | | 586 | do { |
583 | th = atomic_load_consume(&timehands); | | 587 | th = atomic_load_consume(&timehands); |
584 | gen = th->th_generation; | | 588 | gen = th->th_generation; |
585 | membar_consumer(); | | 589 | membar_consumer(); |
586 | bintime2timeval(&th->th_offset, tvp); | | 590 | bintime2timeval(&th->th_offset, tvp); |
587 | membar_consumer(); | | 591 | membar_consumer(); |
588 | } while (gen == 0 || gen != th->th_generation); | | 592 | } while (gen == 0 || gen != th->th_generation); |
589 | } | | 593 | } |
590 | | | 594 | |
591 | void | | 595 | void |
592 | getbintime(struct bintime *bt) | | 596 | getbintime(struct bintime *bt) |
593 | { | | 597 | { |
594 | struct timehands *th; | | 598 | struct timehands *th; |
595 | struct bintime boottime; | | 599 | struct bintime boottime; |
596 | u_int gen; | | 600 | u_int gen; |
597 | | | 601 | |
598 | TC_COUNT(ngetbintime); | | 602 | TC_COUNT(ngetbintime); |
599 | do { | | 603 | do { |
600 | th = atomic_load_consume(&timehands); | | 604 | th = atomic_load_consume(&timehands); |
601 | gen = th->th_generation; | | 605 | gen = th->th_generation; |
602 | membar_consumer(); | | 606 | membar_consumer(); |
603 | *bt = th->th_offset; | | 607 | *bt = th->th_offset; |
604 | membar_consumer(); | | 608 | membar_consumer(); |
605 | } while (gen == 0 || gen != th->th_generation); | | 609 | } while (gen == 0 || gen != th->th_generation); |
606 | getbinboottime(&boottime); | | 610 | getbinboottime(&boottime); |
607 | bintime_add(bt, &boottime); | | 611 | bintime_add(bt, &boottime); |
608 | } | | 612 | } |
609 | | | 613 | |
610 | static inline void | | 614 | static inline void |
611 | dogetnanotime(struct timespec *tsp) | | 615 | dogetnanotime(struct timespec *tsp) |
612 | { | | 616 | { |
613 | struct timehands *th; | | 617 | struct timehands *th; |
614 | u_int gen; | | 618 | u_int gen; |
615 | | | 619 | |
616 | TC_COUNT(ngetnanotime); | | 620 | TC_COUNT(ngetnanotime); |
617 | do { | | 621 | do { |
618 | th = atomic_load_consume(&timehands); | | 622 | th = atomic_load_consume(&timehands); |
619 | gen = th->th_generation; | | 623 | gen = th->th_generation; |
620 | membar_consumer(); | | 624 | membar_consumer(); |
621 | *tsp = th->th_nanotime; | | 625 | *tsp = th->th_nanotime; |
622 | membar_consumer(); | | 626 | membar_consumer(); |
623 | } while (gen == 0 || gen != th->th_generation); | | 627 | } while (gen == 0 || gen != th->th_generation); |
624 | } | | 628 | } |
625 | | | 629 | |
626 | void | | 630 | void |
627 | getnanotime(struct timespec *tsp) | | 631 | getnanotime(struct timespec *tsp) |
628 | { | | 632 | { |
629 | | | 633 | |
630 | dogetnanotime(tsp); | | 634 | dogetnanotime(tsp); |
631 | } | | 635 | } |
632 | | | 636 | |
633 | void dtrace_getnanotime(struct timespec *tsp); | | 637 | void dtrace_getnanotime(struct timespec *tsp); |
634 | | | 638 | |
635 | void | | 639 | void |
636 | dtrace_getnanotime(struct timespec *tsp) | | 640 | dtrace_getnanotime(struct timespec *tsp) |
637 | { | | 641 | { |
638 | | | 642 | |
639 | dogetnanotime(tsp); | | 643 | dogetnanotime(tsp); |
640 | } | | 644 | } |
641 | | | 645 | |
642 | void | | 646 | void |
643 | getmicrotime(struct timeval *tvp) | | 647 | getmicrotime(struct timeval *tvp) |
644 | { | | 648 | { |
645 | struct timehands *th; | | 649 | struct timehands *th; |
646 | u_int gen; | | 650 | u_int gen; |
647 | | | 651 | |
648 | TC_COUNT(ngetmicrotime); | | 652 | TC_COUNT(ngetmicrotime); |
649 | do { | | 653 | do { |
650 | th = atomic_load_consume(&timehands); | | 654 | th = atomic_load_consume(&timehands); |
651 | gen = th->th_generation; | | 655 | gen = th->th_generation; |
652 | membar_consumer(); | | 656 | membar_consumer(); |
653 | *tvp = th->th_microtime; | | 657 | *tvp = th->th_microtime; |
654 | membar_consumer(); | | 658 | membar_consumer(); |
655 | } while (gen == 0 || gen != th->th_generation); | | 659 | } while (gen == 0 || gen != th->th_generation); |
656 | } | | 660 | } |
657 | | | 661 | |
658 | void | | 662 | void |
659 | getnanoboottime(struct timespec *tsp) | | 663 | getnanoboottime(struct timespec *tsp) |
660 | { | | 664 | { |
661 | struct bintime bt; | | 665 | struct bintime bt; |
662 | | | 666 | |
663 | getbinboottime(&bt); | | 667 | getbinboottime(&bt); |
664 | bintime2timespec(&bt, tsp); | | 668 | bintime2timespec(&bt, tsp); |
665 | } | | 669 | } |
666 | | | 670 | |
667 | void | | 671 | void |
668 | getmicroboottime(struct timeval *tvp) | | 672 | getmicroboottime(struct timeval *tvp) |
669 | { | | 673 | { |
670 | struct bintime bt; | | 674 | struct bintime bt; |
671 | | | 675 | |
672 | getbinboottime(&bt); | | 676 | getbinboottime(&bt); |
673 | bintime2timeval(&bt, tvp); | | 677 | bintime2timeval(&bt, tvp); |
674 | } | | 678 | } |
675 | | | 679 | |
676 | void | | 680 | void |
677 | getbinboottime(struct bintime *basep) | | 681 | getbinboottime(struct bintime *basep) |
678 | { | | 682 | { |
679 | struct bintime base; | | 683 | struct bintime base; |
680 | unsigned gen; | | 684 | unsigned gen; |
681 | | | 685 | |
682 | do { | | 686 | do { |
683 | /* Spin until the timebase isn't changing. */ | | 687 | /* Spin until the timebase isn't changing. */ |
684 | while ((gen = atomic_load_relaxed(&timebase.gen)) & 1) | | 688 | while ((gen = atomic_load_relaxed(&timebase.gen)) & 1) |
685 | SPINLOCK_BACKOFF_HOOK; | | 689 | SPINLOCK_BACKOFF_HOOK; |
686 | | | 690 | |
687 | /* Read out a snapshot of the timebase. */ | | 691 | /* Read out a snapshot of the timebase. */ |
688 | membar_consumer(); | | 692 | membar_consumer(); |
689 | base = timebase.bin; | | 693 | base = timebase.bin; |
690 | membar_consumer(); | | 694 | membar_consumer(); |
691 | | | 695 | |
692 | /* Restart if it changed while we were reading. */ | | 696 | /* Restart if it changed while we were reading. */ |
693 | } while (gen != atomic_load_relaxed(&timebase.gen)); | | 697 | } while (gen != atomic_load_relaxed(&timebase.gen)); |
694 | | | 698 | |
695 | *basep = base; | | 699 | *basep = base; |
696 | } | | 700 | } |
697 | | | 701 | |
698 | /* | | 702 | /* |
699 | * Initialize a new timecounter and possibly use it. | | 703 | * Initialize a new timecounter and possibly use it. |
700 | */ | | 704 | */ |
701 | void | | 705 | void |
702 | tc_init(struct timecounter *tc) | | 706 | tc_init(struct timecounter *tc) |
703 | { | | 707 | { |
704 | u_int u; | | 708 | u_int u; |
705 | | | 709 | |
706 | KASSERTMSG(tc->tc_next == NULL, "timecounter %s already initialised", | | 710 | KASSERTMSG(tc->tc_next == NULL, "timecounter %s already initialised", |
707 | tc->tc_name); | | 711 | tc->tc_name); |
708 | | | 712 | |
709 | u = tc->tc_frequency / tc->tc_counter_mask; | | 713 | u = tc->tc_frequency / tc->tc_counter_mask; |
710 | /* XXX: We need some margin here, 10% is a guess */ | | 714 | /* XXX: We need some margin here, 10% is a guess */ |
711 | u *= 11; | | 715 | u *= 11; |
712 | u /= 10; | | 716 | u /= 10; |
713 | if (u > hz && tc->tc_quality >= 0) { | | 717 | if (u > hz && tc->tc_quality >= 0) { |
714 | tc->tc_quality = -2000; | | 718 | tc->tc_quality = -2000; |
715 | aprint_verbose( | | 719 | aprint_verbose( |
716 | "timecounter: Timecounter \"%s\" frequency %ju Hz", | | 720 | "timecounter: Timecounter \"%s\" frequency %ju Hz", |
717 | tc->tc_name, (uintmax_t)tc->tc_frequency); | | 721 | tc->tc_name, (uintmax_t)tc->tc_frequency); |
718 | aprint_verbose(" -- Insufficient hz, needs at least %u\n", u); | | 722 | aprint_verbose(" -- Insufficient hz, needs at least %u\n", u); |
719 | } else if (tc->tc_quality >= 0 || bootverbose) { | | 723 | } else if (tc->tc_quality >= 0 || bootverbose) { |
720 | aprint_verbose( | | 724 | aprint_verbose( |
721 | "timecounter: Timecounter \"%s\" frequency %ju Hz " | | 725 | "timecounter: Timecounter \"%s\" frequency %ju Hz " |
722 | "quality %d\n", tc->tc_name, (uintmax_t)tc->tc_frequency, | | 726 | "quality %d\n", tc->tc_name, (uintmax_t)tc->tc_frequency, |
723 | tc->tc_quality); | | 727 | tc->tc_quality); |
724 | } | | 728 | } |
725 | | | 729 | |
726 | mutex_spin_enter(&timecounter_lock); | | 730 | mutex_spin_enter(&timecounter_lock); |
727 | tc->tc_next = timecounters; | | 731 | tc->tc_next = timecounters; |
728 | timecounters = tc; | | 732 | timecounters = tc; |
729 | timecounter_mods++; | | 733 | timecounter_mods++; |
730 | /* | | 734 | /* |
731 | * Never automatically use a timecounter with negative quality. | | 735 | * Never automatically use a timecounter with negative quality. |
732 | * Even though we run on the dummy counter, switching here may be | | 736 | * Even though we run on the dummy counter, switching here may be |
733 | * worse since this timecounter may not be monotonous. | | 737 | * worse since this timecounter may not be monotonous. |
734 | */ | | 738 | */ |
735 | if (tc->tc_quality >= 0 && (tc->tc_quality > timecounter->tc_quality || | | 739 | if (tc->tc_quality >= 0 && (tc->tc_quality > timecounter->tc_quality || |
736 | (tc->tc_quality == timecounter->tc_quality && | | 740 | (tc->tc_quality == timecounter->tc_quality && |
737 | tc->tc_frequency > timecounter->tc_frequency))) { | | 741 | tc->tc_frequency > timecounter->tc_frequency))) { |
738 | (void)tc->tc_get_timecount(tc); | | 742 | (void)tc->tc_get_timecount(tc); |
739 | (void)tc->tc_get_timecount(tc); | | 743 | (void)tc->tc_get_timecount(tc); |
740 | timecounter = tc; | | 744 | timecounter = tc; |
741 | tc_windup(); | | 745 | tc_windup(); |
742 | } | | 746 | } |
743 | mutex_spin_exit(&timecounter_lock); | | 747 | mutex_spin_exit(&timecounter_lock); |
744 | } | | 748 | } |
745 | | | 749 | |
746 | /* | | 750 | /* |
747 | * Pick a new timecounter due to the existing counter going bad. | | 751 | * Pick a new timecounter due to the existing counter going bad. |
748 | */ | | 752 | */ |
749 | static void | | 753 | static void |
750 | tc_pick(void) | | 754 | tc_pick(void) |
751 | { | | 755 | { |
752 | struct timecounter *best, *tc; | | 756 | struct timecounter *best, *tc; |
753 | | | 757 | |
754 | KASSERT(mutex_owned(&timecounter_lock)); | | 758 | KASSERT(mutex_owned(&timecounter_lock)); |
755 | | | 759 | |
756 | for (best = tc = timecounters; tc != NULL; tc = tc->tc_next) { | | 760 | for (best = tc = timecounters; tc != NULL; tc = tc->tc_next) { |
757 | if (tc->tc_quality > best->tc_quality) | | 761 | if (tc->tc_quality > best->tc_quality) |
758 | best = tc; | | 762 | best = tc; |
759 | else if (tc->tc_quality < best->tc_quality) | | 763 | else if (tc->tc_quality < best->tc_quality) |
760 | continue; | | 764 | continue; |
761 | else if (tc->tc_frequency > best->tc_frequency) | | 765 | else if (tc->tc_frequency > best->tc_frequency) |
762 | best = tc; | | 766 | best = tc; |
763 | } | | 767 | } |
764 | (void)best->tc_get_timecount(best); | | 768 | (void)best->tc_get_timecount(best); |
765 | (void)best->tc_get_timecount(best); | | 769 | (void)best->tc_get_timecount(best); |
766 | timecounter = best; | | 770 | timecounter = best; |
767 | } | | 771 | } |
768 | | | 772 | |
769 | /* | | 773 | /* |
770 | * A timecounter has gone bad, arrange to pick a new one at the next | | 774 | * A timecounter has gone bad, arrange to pick a new one at the next |
771 | * clock tick. | | 775 | * clock tick. |
772 | */ | | 776 | */ |
773 | void | | 777 | void |
774 | tc_gonebad(struct timecounter *tc) | | 778 | tc_gonebad(struct timecounter *tc) |
775 | { | | 779 | { |
776 | | | 780 | |
777 | tc->tc_quality = -100; | | 781 | tc->tc_quality = -100; |
778 | membar_producer(); | | 782 | membar_producer(); |
779 | atomic_inc_uint(&timecounter_bad); | | 783 | atomic_inc_uint(&timecounter_bad); |
780 | } | | 784 | } |
781 | | | 785 | |
782 | /* | | 786 | /* |
783 | * Stop using a timecounter and remove it from the timecounters list. | | 787 | * Stop using a timecounter and remove it from the timecounters list. |
784 | */ | | 788 | */ |
785 | int | | 789 | int |
786 | tc_detach(struct timecounter *target) | | 790 | tc_detach(struct timecounter *target) |
787 | { | | 791 | { |
788 | struct timecounter *tc; | | 792 | struct timecounter *tc; |
789 | struct timecounter **tcp = NULL; | | 793 | struct timecounter **tcp = NULL; |
790 | int removals; | | 794 | int removals; |
791 | lwp_t *l; | | 795 | lwp_t *l; |
792 | | | 796 | |
793 | /* First, find the timecounter. */ | | 797 | /* First, find the timecounter. */ |
794 | mutex_spin_enter(&timecounter_lock); | | 798 | mutex_spin_enter(&timecounter_lock); |
795 | for (tcp = &timecounters, tc = timecounters; | | 799 | for (tcp = &timecounters, tc = timecounters; |
796 | tc != NULL; | | 800 | tc != NULL; |
797 | tcp = &tc->tc_next, tc = tc->tc_next) { | | 801 | tcp = &tc->tc_next, tc = tc->tc_next) { |
798 | if (tc == target) | | 802 | if (tc == target) |
799 | break; | | 803 | break; |
800 | } | | 804 | } |
801 | if (tc == NULL) { | | 805 | if (tc == NULL) { |
802 | mutex_spin_exit(&timecounter_lock); | | 806 | mutex_spin_exit(&timecounter_lock); |
803 | return ESRCH; | | 807 | return ESRCH; |
804 | } | | 808 | } |
805 | | | 809 | |
806 | /* And now, remove it. */ | | 810 | /* And now, remove it. */ |
807 | *tcp = tc->tc_next; | | 811 | *tcp = tc->tc_next; |
808 | if (timecounter == target) { | | 812 | if (timecounter == target) { |
809 | tc_pick(); | | 813 | tc_pick(); |
810 | tc_windup(); | | 814 | tc_windup(); |
811 | } | | 815 | } |
812 | timecounter_mods++; | | 816 | timecounter_mods++; |
813 | removals = timecounter_removals++; | | 817 | removals = timecounter_removals++; |
814 | mutex_spin_exit(&timecounter_lock); | | 818 | mutex_spin_exit(&timecounter_lock); |
815 | | | 819 | |
816 | /* | | 820 | /* |
817 | * We now have to determine if any threads in the system are still | | 821 | * We now have to determine if any threads in the system are still |
818 | * making use of this timecounter. | | 822 | * making use of this timecounter. |
819 | * | | 823 | * |
820 | * We issue a broadcast cross call to elide memory ordering issues, | | 824 | * We issue a broadcast cross call to elide memory ordering issues, |
821 | * then scan all LWPs in the system looking at each's timecounter | | 825 | * then scan all LWPs in the system looking at each's timecounter |
822 | * generation number. We need to see a value of zero (not actively | | 826 | * generation number. We need to see a value of zero (not actively |
823 | * using a timecounter) or a value greater than our removal value. | | 827 | * using a timecounter) or a value greater than our removal value. |
824 | * | | 828 | * |
825 | * We may race with threads that read `timecounter_removals' and | | 829 | * We may race with threads that read `timecounter_removals' and |
826 | * and then get preempted before updating `l_tcgen'. This is not | | 830 | * and then get preempted before updating `l_tcgen'. This is not |
827 | * a problem, since it means that these threads have not yet started | | 831 | * a problem, since it means that these threads have not yet started |
828 | * accessing timecounter state. All we do need is one clean | | 832 | * accessing timecounter state. All we do need is one clean |
829 | * snapshot of the system where every thread appears not to be using | | 833 | * snapshot of the system where every thread appears not to be using |
830 | * old timecounter state. | | 834 | * old timecounter state. |
831 | */ | | 835 | */ |
832 | for (;;) { | | 836 | for (;;) { |
833 | xc_barrier(0); | | 837 | xc_barrier(0); |
834 | | | 838 | |
835 | mutex_enter(&proc_lock); | | 839 | mutex_enter(&proc_lock); |
836 | LIST_FOREACH(l, &alllwp, l_list) { | | 840 | LIST_FOREACH(l, &alllwp, l_list) { |
837 | if (l->l_tcgen == 0 || l->l_tcgen > removals) { | | 841 | if (l->l_tcgen == 0 || l->l_tcgen > removals) { |
838 | /* | | 842 | /* |
839 | * Not using timecounter or old timecounter | | 843 | * Not using timecounter or old timecounter |
840 | * state at time of our xcall or later. | | 844 | * state at time of our xcall or later. |
841 | */ | | 845 | */ |
842 | continue; | | 846 | continue; |
843 | } | | 847 | } |
844 | break; | | 848 | break; |
845 | } | | 849 | } |
846 | mutex_exit(&proc_lock); | | 850 | mutex_exit(&proc_lock); |
847 | | | 851 | |
848 | /* | | 852 | /* |
849 | * If the timecounter is still in use, wait at least 10ms | | 853 | * If the timecounter is still in use, wait at least 10ms |
850 | * before retrying. | | 854 | * before retrying. |
851 | */ | | 855 | */ |
852 | if (l == NULL) { | | 856 | if (l == NULL) { |
853 | break; | | 857 | break; |
854 | } | | 858 | } |
855 | (void)kpause("tcdetach", false, mstohz(10), NULL); | | 859 | (void)kpause("tcdetach", false, mstohz(10), NULL); |
856 | } | | 860 | } |
857 | | | 861 | |
858 | tc->tc_next = NULL; | | 862 | tc->tc_next = NULL; |
859 | return 0; | | 863 | return 0; |
860 | } | | 864 | } |
861 | | | 865 | |
862 | /* Report the frequency of the current timecounter. */ | | 866 | /* Report the frequency of the current timecounter. */ |
863 | uint64_t | | 867 | uint64_t |
864 | tc_getfrequency(void) | | 868 | tc_getfrequency(void) |
865 | { | | 869 | { |
866 | | | 870 | |
867 | return atomic_load_consume(&timehands)->th_counter->tc_frequency; | | 871 | return atomic_load_consume(&timehands)->th_counter->tc_frequency; |
868 | } | | 872 | } |
869 | | | 873 | |
870 | /* | | 874 | /* |
871 | * Step our concept of UTC. This is done by modifying our estimate of | | 875 | * Step our concept of UTC. This is done by modifying our estimate of |
872 | * when we booted. | | 876 | * when we booted. |
873 | */ | | 877 | */ |
874 | void | | 878 | void |
875 | tc_setclock(const struct timespec *ts) | | 879 | tc_setclock(const struct timespec *ts) |
876 | { | | 880 | { |
877 | struct timespec ts2; | | 881 | struct timespec ts2; |
878 | struct bintime bt, bt2; | | 882 | struct bintime bt, bt2; |
879 | | | 883 | |
880 | mutex_spin_enter(&timecounter_lock); | | 884 | mutex_spin_enter(&timecounter_lock); |
881 | TC_COUNT(nsetclock); | | 885 | TC_COUNT(nsetclock); |
882 | binuptime(&bt2); | | 886 | binuptime(&bt2); |
883 | timespec2bintime(ts, &bt); | | 887 | timespec2bintime(ts, &bt); |
884 | bintime_sub(&bt, &bt2); | | 888 | bintime_sub(&bt, &bt2); |
885 | bintime_add(&bt2, &timebase.bin); | | 889 | bintime_add(&bt2, &timebase.bin); |
886 | timebase.gen |= 1; /* change in progress */ | | 890 | timebase.gen |= 1; /* change in progress */ |
887 | membar_producer(); | | 891 | membar_producer(); |
888 | timebase.bin = bt; | | 892 | timebase.bin = bt; |
889 | membar_producer(); | | 893 | membar_producer(); |
890 | timebase.gen++; /* commit change */ | | 894 | timebase.gen++; /* commit change */ |
891 | tc_windup(); | | 895 | tc_windup(); |
892 | mutex_spin_exit(&timecounter_lock); | | 896 | mutex_spin_exit(&timecounter_lock); |
893 | | | 897 | |
894 | if (timestepwarnings) { | | 898 | if (timestepwarnings) { |
895 | bintime2timespec(&bt2, &ts2); | | 899 | bintime2timespec(&bt2, &ts2); |
896 | log(LOG_INFO, | | 900 | log(LOG_INFO, |
897 | "Time stepped from %lld.%09ld to %lld.%09ld\n", | | 901 | "Time stepped from %lld.%09ld to %lld.%09ld\n", |
898 | (long long)ts2.tv_sec, ts2.tv_nsec, | | 902 | (long long)ts2.tv_sec, ts2.tv_nsec, |
899 | (long long)ts->tv_sec, ts->tv_nsec); | | 903 | (long long)ts->tv_sec, ts->tv_nsec); |
900 | } | | 904 | } |
901 | } | | 905 | } |
902 | | | 906 | |
903 | /* | | 907 | /* |
904 | * Initialize the next struct timehands in the ring and make | | 908 | * Initialize the next struct timehands in the ring and make |
905 | * it the active timehands. Along the way we might switch to a different | | 909 | * it the active timehands. Along the way we might switch to a different |
906 | * timecounter and/or do seconds processing in NTP. Slightly magic. | | 910 | * timecounter and/or do seconds processing in NTP. Slightly magic. |
907 | */ | | 911 | */ |
908 | static void | | 912 | static void |
909 | tc_windup(void) | | 913 | tc_windup(void) |
910 | { | | 914 | { |
911 | struct bintime bt; | | 915 | struct bintime bt; |
912 | struct timehands *th, *tho; | | 916 | struct timehands *th, *tho; |
913 | uint64_t scale; | | 917 | uint64_t scale; |
914 | u_int delta, ncount, ogen; | | 918 | u_int delta, ncount, ogen; |
915 | int i, s_update; | | 919 | int i, s_update; |
916 | time_t t; | | 920 | time_t t; |
917 | | | 921 | |
918 | KASSERT(mutex_owned(&timecounter_lock)); | | 922 | KASSERT(mutex_owned(&timecounter_lock)); |
919 | | | 923 | |
920 | s_update = 0; | | 924 | s_update = 0; |
921 | | | 925 | |
922 | /* | | 926 | /* |
923 | * Make the next timehands a copy of the current one, but do not | | 927 | * Make the next timehands a copy of the current one, but do not |
924 | * overwrite the generation or next pointer. While we update | | 928 | * overwrite the generation or next pointer. While we update |
925 | * the contents, the generation must be zero. Ensure global | | 929 | * the contents, the generation must be zero. Ensure global |
926 | * visibility of the generation before proceeding. | | 930 | * visibility of the generation before proceeding. |
927 | */ | | 931 | */ |
928 | tho = timehands; | | 932 | tho = timehands; |
929 | th = tho->th_next; | | 933 | th = tho->th_next; |
930 | ogen = th->th_generation; | | 934 | ogen = th->th_generation; |
931 | th->th_generation = 0; | | 935 | th->th_generation = 0; |
932 | membar_producer(); | | 936 | membar_producer(); |
933 | bcopy(tho, th, offsetof(struct timehands, th_generation)); | | 937 | bcopy(tho, th, offsetof(struct timehands, th_generation)); |
934 | | | 938 | |
935 | /* | | 939 | /* |
936 | * Capture a timecounter delta on the current timecounter and if | | 940 | * Capture a timecounter delta on the current timecounter and if |
937 | * changing timecounters, a counter value from the new timecounter. | | 941 | * changing timecounters, a counter value from the new timecounter. |
938 | * Update the offset fields accordingly. | | 942 | * Update the offset fields accordingly. |
939 | */ | | 943 | */ |
940 | delta = tc_delta(th); | | 944 | delta = tc_delta(th); |
941 | if (th->th_counter != timecounter) | | 945 | if (th->th_counter != timecounter) |
942 | ncount = timecounter->tc_get_timecount(timecounter); | | 946 | ncount = timecounter->tc_get_timecount(timecounter); |
943 | else | | 947 | else |
944 | ncount = 0; | | 948 | ncount = 0; |
945 | th->th_offset_count += delta; | | 949 | th->th_offset_count += delta; |
946 | bintime_addx(&th->th_offset, th->th_scale * delta); | | 950 | bintime_addx(&th->th_offset, th->th_scale * delta); |
947 | | | 951 | |
948 | /* | | 952 | /* |
949 | * Hardware latching timecounters may not generate interrupts on | | 953 | * Hardware latching timecounters may not generate interrupts on |
950 | * PPS events, so instead we poll them. There is a finite risk that | | 954 | * PPS events, so instead we poll them. There is a finite risk that |
951 | * the hardware might capture a count which is later than the one we | | 955 | * the hardware might capture a count which is later than the one we |
952 | * got above, and therefore possibly in the next NTP second which might | | 956 | * got above, and therefore possibly in the next NTP second which might |
953 | * have a different rate than the current NTP second. It doesn't | | 957 | * have a different rate than the current NTP second. It doesn't |
954 | * matter in practice. | | 958 | * matter in practice. |
955 | */ | | 959 | */ |
956 | if (tho->th_counter->tc_poll_pps) | | 960 | if (tho->th_counter->tc_poll_pps) |
957 | tho->th_counter->tc_poll_pps(tho->th_counter); | | 961 | tho->th_counter->tc_poll_pps(tho->th_counter); |
958 | | | 962 | |
959 | /* | | 963 | /* |
960 | * Deal with NTP second processing. The for loop normally | | 964 | * Deal with NTP second processing. The for loop normally |
961 | * iterates at most once, but in extreme situations it might | | 965 | * iterates at most once, but in extreme situations it might |
962 | * keep NTP sane if timeouts are not run for several seconds. | | 966 | * keep NTP sane if timeouts are not run for several seconds. |
963 | * At boot, the time step can be large when the TOD hardware | | 967 | * At boot, the time step can be large when the TOD hardware |
964 | * has been read, so on really large steps, we call | | 968 | * has been read, so on really large steps, we call |
965 | * ntp_update_second only twice. We need to call it twice in | | 969 | * ntp_update_second only twice. We need to call it twice in |
966 | * case we missed a leap second. | | 970 | * case we missed a leap second. |
967 | * If NTP is not compiled in ntp_update_second still calculates | | 971 | * If NTP is not compiled in ntp_update_second still calculates |
968 | * the adjustment resulting from adjtime() calls. | | 972 | * the adjustment resulting from adjtime() calls. |
969 | */ | | 973 | */ |
970 | bt = th->th_offset; | | 974 | bt = th->th_offset; |
971 | bintime_add(&bt, &timebase.bin); | | 975 | bintime_add(&bt, &timebase.bin); |
972 | i = bt.sec - tho->th_microtime.tv_sec; | | 976 | i = bt.sec - tho->th_microtime.tv_sec; |
973 | if (i > LARGE_STEP) | | 977 | if (i > LARGE_STEP) |
974 | i = 2; | | 978 | i = 2; |
975 | for (; i > 0; i--) { | | 979 | for (; i > 0; i--) { |
976 | t = bt.sec; | | 980 | t = bt.sec; |
977 | ntp_update_second(&th->th_adjustment, &bt.sec); | | 981 | ntp_update_second(&th->th_adjustment, &bt.sec); |
978 | s_update = 1; | | 982 | s_update = 1; |
979 | if (bt.sec != t) { | | 983 | if (bt.sec != t) { |
980 | timebase.gen |= 1; /* change in progress */ | | 984 | timebase.gen |= 1; /* change in progress */ |
981 | membar_producer(); | | 985 | membar_producer(); |
982 | timebase.bin.sec += bt.sec - t; | | 986 | timebase.bin.sec += bt.sec - t; |
983 | membar_producer(); | | 987 | membar_producer(); |
984 | timebase.gen++; /* commit change */ | | 988 | timebase.gen++; /* commit change */ |
985 | } | | 989 | } |
986 | } | | 990 | } |
987 | | | 991 | |
988 | /* Update the UTC timestamps used by the get*() functions. */ | | 992 | /* Update the UTC timestamps used by the get*() functions. */ |
989 | /* XXX shouldn't do this here. Should force non-`get' versions. */ | | 993 | /* XXX shouldn't do this here. Should force non-`get' versions. */ |
990 | bintime2timeval(&bt, &th->th_microtime); | | 994 | bintime2timeval(&bt, &th->th_microtime); |
991 | bintime2timespec(&bt, &th->th_nanotime); | | 995 | bintime2timespec(&bt, &th->th_nanotime); |
992 | /* Now is a good time to change timecounters. */ | | 996 | /* Now is a good time to change timecounters. */ |
993 | if (th->th_counter != timecounter) { | | 997 | if (th->th_counter != timecounter) { |
994 | th->th_counter = timecounter; | | 998 | th->th_counter = timecounter; |
995 | th->th_offset_count = ncount; | | 999 | th->th_offset_count = ncount; |
996 | s_update = 1; | | 1000 | s_update = 1; |
997 | } | | 1001 | } |
998 | | | 1002 | |
999 | /*- | | 1003 | /*- |
1000 | * Recalculate the scaling factor. We want the number of 1/2^64 | | 1004 | * Recalculate the scaling factor. We want the number of 1/2^64 |
1001 | * fractions of a second per period of the hardware counter, taking | | 1005 | * fractions of a second per period of the hardware counter, taking |
1002 | * into account the th_adjustment factor which the NTP PLL/adjtime(2) | | 1006 | * into account the th_adjustment factor which the NTP PLL/adjtime(2) |
1003 | * processing provides us with. | | 1007 | * processing provides us with. |
1004 | * | | 1008 | * |
1005 | * The th_adjustment is nanoseconds per second with 32 bit binary | | 1009 | * The th_adjustment is nanoseconds per second with 32 bit binary |
1006 | * fraction and we want 64 bit binary fraction of second: | | 1010 | * fraction and we want 64 bit binary fraction of second: |
1007 | * | | 1011 | * |
1008 | * x = a * 2^32 / 10^9 = a * 4.294967296 | | 1012 | * x = a * 2^32 / 10^9 = a * 4.294967296 |
1009 | * | | 1013 | * |
1010 | * The range of th_adjustment is +/- 5000PPM so inside a 64bit int | | 1014 | * The range of th_adjustment is +/- 5000PPM so inside a 64bit int |
1011 | * we can only multiply by about 850 without overflowing, but that | | 1015 | * we can only multiply by about 850 without overflowing, but that |
1012 | * leaves suitably precise fractions for multiply before divide. | | 1016 | * leaves suitably precise fractions for multiply before divide. |
1013 | * | | 1017 | * |
1014 | * Divide before multiply with a fraction of 2199/512 results in a | | 1018 | * Divide before multiply with a fraction of 2199/512 results in a |
1015 | * systematic undercompensation of 10PPM of th_adjustment. On a | | 1019 | * systematic undercompensation of 10PPM of th_adjustment. On a |
1016 | * 5000PPM adjustment this is a 0.05PPM error. This is acceptable. | | 1020 | * 5000PPM adjustment this is a 0.05PPM error. This is acceptable. |
1017 | * | | 1021 | * |
1018 | * We happily sacrifice the lowest of the 64 bits of our result | | 1022 | * We happily sacrifice the lowest of the 64 bits of our result |
1019 | * to the goddess of code clarity. | | 1023 | * to the goddess of code clarity. |
1020 | * | | 1024 | * |
1021 | */ | | 1025 | */ |
1022 | if (s_update) { | | 1026 | if (s_update) { |
1023 | scale = (uint64_t)1 << 63; | | 1027 | scale = (uint64_t)1 << 63; |
1024 | scale += (th->th_adjustment / 1024) * 2199; | | 1028 | scale += (th->th_adjustment / 1024) * 2199; |
1025 | scale /= th->th_counter->tc_frequency; | | 1029 | scale /= th->th_counter->tc_frequency; |
1026 | th->th_scale = scale * 2; | | 1030 | th->th_scale = scale * 2; |
1027 | } | | 1031 | } |
1028 | /* | | 1032 | /* |
1029 | * Now that the struct timehands is again consistent, set the new | | 1033 | * Now that the struct timehands is again consistent, set the new |
1030 | * generation number, making sure to not make it zero. Ensure | | 1034 | * generation number, making sure to not make it zero. Ensure |
1031 | * changes are globally visible before changing. | | 1035 | * changes are globally visible before changing. |
1032 | */ | | 1036 | */ |
1033 | if (++ogen == 0) | | 1037 | if (++ogen == 0) |
1034 | ogen = 1; | | 1038 | ogen = 1; |
1035 | membar_producer(); | | 1039 | membar_producer(); |
1036 | th->th_generation = ogen; | | 1040 | th->th_generation = ogen; |
1037 | | | 1041 | |
1038 | /* | | 1042 | /* |
1039 | * Go live with the new struct timehands. Ensure changes are | | 1043 | * Go live with the new struct timehands. Ensure changes are |
1040 | * globally visible before changing. | | 1044 | * globally visible before changing. |
1041 | */ | | 1045 | */ |
1042 | setrealuptime(th->th_microtime.tv_sec, th->th_offset.sec); | | 1046 | setrealuptime(th->th_microtime.tv_sec, th->th_offset.sec); |