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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2006 Andi Kleen, SUSE Labs.
4 *
5 * Fast user context implementation of clock_gettime, gettimeofday, and time.
6 *
7 * The code should have no internal unresolved relocations.
8 * Check with readelf after changing.
9 * Also alternative() doesn't work.
10 */
11/*
12 * Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved.
13 */
14
15#include <linux/kernel.h>
16#include <linux/time.h>
17#include <linux/string.h>
18#include <asm/io.h>
19#include <asm/unistd.h>
20#include <asm/timex.h>
21#include <asm/clocksource.h>
22#include <asm/vvar.h>
23
24#ifdef CONFIG_SPARC64
25#define SYSCALL_STRING \
26 "ta 0x6d;" \
27 "bcs,a 1f;" \
28 " sub %%g0, %%o0, %%o0;" \
29 "1:"
30#else
31#define SYSCALL_STRING \
32 "ta 0x10;" \
33 "bcs,a 1f;" \
34 " sub %%g0, %%o0, %%o0;" \
35 "1:"
36#endif
37
38#define SYSCALL_CLOBBERS \
39 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
40 "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", \
41 "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23", \
42 "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31", \
43 "f32", "f34", "f36", "f38", "f40", "f42", "f44", "f46", \
44 "f48", "f50", "f52", "f54", "f56", "f58", "f60", "f62", \
45 "cc", "memory"
46
47/*
48 * Compute the vvar page's address in the process address space, and return it
49 * as a pointer to the vvar_data.
50 */
51notrace static __always_inline struct vvar_data *get_vvar_data(void)
52{
53 unsigned long ret;
54
55 /*
56 * vdso data page is the first vDSO page so grab the PC
57 * and move up a page to get to the data page.
58 */
59 __asm__("rd %%pc, %0" : "=r" (ret));
60 ret &= ~(8192 - 1);
61 ret -= 8192;
62
63 return (struct vvar_data *) ret;
64}
65
66notrace static long vdso_fallback_gettime(long clock, struct __kernel_old_timespec *ts)
67{
68 register long num __asm__("g1") = __NR_clock_gettime;
69 register long o0 __asm__("o0") = clock;
70 register long o1 __asm__("o1") = (long) ts;
71
72 __asm__ __volatile__(SYSCALL_STRING : "=r" (o0) : "r" (num),
73 "0" (o0), "r" (o1) : SYSCALL_CLOBBERS);
74 return o0;
75}
76
77notrace static long vdso_fallback_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
78{
79 register long num __asm__("g1") = __NR_gettimeofday;
80 register long o0 __asm__("o0") = (long) tv;
81 register long o1 __asm__("o1") = (long) tz;
82
83 __asm__ __volatile__(SYSCALL_STRING : "=r" (o0) : "r" (num),
84 "0" (o0), "r" (o1) : SYSCALL_CLOBBERS);
85 return o0;
86}
87
88#ifdef CONFIG_SPARC64
89notrace static __always_inline u64 vread_tick(void)
90{
91 u64 ret;
92
93 __asm__ __volatile__("rd %%tick, %0" : "=r" (ret));
94 return ret;
95}
96
97notrace static __always_inline u64 vread_tick_stick(void)
98{
99 u64 ret;
100
101 __asm__ __volatile__("rd %%asr24, %0" : "=r" (ret));
102 return ret;
103}
104#else
105notrace static __always_inline u64 vread_tick(void)
106{
107 register unsigned long long ret asm("o4");
108
109 __asm__ __volatile__("rd %%tick, %L0\n\t"
110 "srlx %L0, 32, %H0"
111 : "=r" (ret));
112 return ret;
113}
114
115notrace static __always_inline u64 vread_tick_stick(void)
116{
117 register unsigned long long ret asm("o4");
118
119 __asm__ __volatile__("rd %%asr24, %L0\n\t"
120 "srlx %L0, 32, %H0"
121 : "=r" (ret));
122 return ret;
123}
124#endif
125
126notrace static __always_inline u64 vgetsns(struct vvar_data *vvar)
127{
128 u64 v;
129 u64 cycles;
130
131 cycles = vread_tick();
132 v = (cycles - vvar->clock.cycle_last) & vvar->clock.mask;
133 return v * vvar->clock.mult;
134}
135
136notrace static __always_inline u64 vgetsns_stick(struct vvar_data *vvar)
137{
138 u64 v;
139 u64 cycles;
140
141 cycles = vread_tick_stick();
142 v = (cycles - vvar->clock.cycle_last) & vvar->clock.mask;
143 return v * vvar->clock.mult;
144}
145
146notrace static __always_inline int do_realtime(struct vvar_data *vvar,
147 struct __kernel_old_timespec *ts)
148{
149 unsigned long seq;
150 u64 ns;
151
152 do {
153 seq = vvar_read_begin(vvar);
154 ts->tv_sec = vvar->wall_time_sec;
155 ns = vvar->wall_time_snsec;
156 ns += vgetsns(vvar);
157 ns >>= vvar->clock.shift;
158 } while (unlikely(vvar_read_retry(vvar, seq)));
159
160 ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
161 ts->tv_nsec = ns;
162
163 return 0;
164}
165
166notrace static __always_inline int do_realtime_stick(struct vvar_data *vvar,
167 struct __kernel_old_timespec *ts)
168{
169 unsigned long seq;
170 u64 ns;
171
172 do {
173 seq = vvar_read_begin(vvar);
174 ts->tv_sec = vvar->wall_time_sec;
175 ns = vvar->wall_time_snsec;
176 ns += vgetsns_stick(vvar);
177 ns >>= vvar->clock.shift;
178 } while (unlikely(vvar_read_retry(vvar, seq)));
179
180 ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
181 ts->tv_nsec = ns;
182
183 return 0;
184}
185
186notrace static __always_inline int do_monotonic(struct vvar_data *vvar,
187 struct __kernel_old_timespec *ts)
188{
189 unsigned long seq;
190 u64 ns;
191
192 do {
193 seq = vvar_read_begin(vvar);
194 ts->tv_sec = vvar->monotonic_time_sec;
195 ns = vvar->monotonic_time_snsec;
196 ns += vgetsns(vvar);
197 ns >>= vvar->clock.shift;
198 } while (unlikely(vvar_read_retry(vvar, seq)));
199
200 ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
201 ts->tv_nsec = ns;
202
203 return 0;
204}
205
206notrace static __always_inline int do_monotonic_stick(struct vvar_data *vvar,
207 struct __kernel_old_timespec *ts)
208{
209 unsigned long seq;
210 u64 ns;
211
212 do {
213 seq = vvar_read_begin(vvar);
214 ts->tv_sec = vvar->monotonic_time_sec;
215 ns = vvar->monotonic_time_snsec;
216 ns += vgetsns_stick(vvar);
217 ns >>= vvar->clock.shift;
218 } while (unlikely(vvar_read_retry(vvar, seq)));
219
220 ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
221 ts->tv_nsec = ns;
222
223 return 0;
224}
225
226notrace static int do_realtime_coarse(struct vvar_data *vvar,
227 struct __kernel_old_timespec *ts)
228{
229 unsigned long seq;
230
231 do {
232 seq = vvar_read_begin(vvar);
233 ts->tv_sec = vvar->wall_time_coarse_sec;
234 ts->tv_nsec = vvar->wall_time_coarse_nsec;
235 } while (unlikely(vvar_read_retry(vvar, seq)));
236 return 0;
237}
238
239notrace static int do_monotonic_coarse(struct vvar_data *vvar,
240 struct __kernel_old_timespec *ts)
241{
242 unsigned long seq;
243
244 do {
245 seq = vvar_read_begin(vvar);
246 ts->tv_sec = vvar->monotonic_time_coarse_sec;
247 ts->tv_nsec = vvar->monotonic_time_coarse_nsec;
248 } while (unlikely(vvar_read_retry(vvar, seq)));
249
250 return 0;
251}
252
253notrace int
254__vdso_clock_gettime(clockid_t clock, struct __kernel_old_timespec *ts)
255{
256 struct vvar_data *vvd = get_vvar_data();
257
258 switch (clock) {
259 case CLOCK_REALTIME:
260 if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
261 break;
262 return do_realtime(vvd, ts);
263 case CLOCK_MONOTONIC:
264 if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
265 break;
266 return do_monotonic(vvd, ts);
267 case CLOCK_REALTIME_COARSE:
268 return do_realtime_coarse(vvd, ts);
269 case CLOCK_MONOTONIC_COARSE:
270 return do_monotonic_coarse(vvd, ts);
271 }
272 /*
273 * Unknown clock ID ? Fall back to the syscall.
274 */
275 return vdso_fallback_gettime(clock, ts);
276}
277int
278clock_gettime(clockid_t, struct __kernel_old_timespec *)
279 __attribute__((weak, alias("__vdso_clock_gettime")));
280
281notrace int
282__vdso_clock_gettime_stick(clockid_t clock, struct __kernel_old_timespec *ts)
283{
284 struct vvar_data *vvd = get_vvar_data();
285
286 switch (clock) {
287 case CLOCK_REALTIME:
288 if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
289 break;
290 return do_realtime_stick(vvd, ts);
291 case CLOCK_MONOTONIC:
292 if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
293 break;
294 return do_monotonic_stick(vvd, ts);
295 case CLOCK_REALTIME_COARSE:
296 return do_realtime_coarse(vvd, ts);
297 case CLOCK_MONOTONIC_COARSE:
298 return do_monotonic_coarse(vvd, ts);
299 }
300 /*
301 * Unknown clock ID ? Fall back to the syscall.
302 */
303 return vdso_fallback_gettime(clock, ts);
304}
305
306notrace int
307__vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
308{
309 struct vvar_data *vvd = get_vvar_data();
310
311 if (likely(vvd->vclock_mode != VCLOCK_NONE)) {
312 if (likely(tv != NULL)) {
313 union tstv_t {
314 struct __kernel_old_timespec ts;
315 struct __kernel_old_timeval tv;
316 } *tstv = (union tstv_t *) tv;
317 do_realtime(vvd, &tstv->ts);
318 /*
319 * Assign before dividing to ensure that the division is
320 * done in the type of tv_usec, not tv_nsec.
321 *
322 * There cannot be > 1 billion usec in a second:
323 * do_realtime() has already distributed such overflow
324 * into tv_sec. So we can assign it to an int safely.
325 */
326 tstv->tv.tv_usec = tstv->ts.tv_nsec;
327 tstv->tv.tv_usec /= 1000;
328 }
329 if (unlikely(tz != NULL)) {
330 /* Avoid memcpy. Some old compilers fail to inline it */
331 tz->tz_minuteswest = vvd->tz_minuteswest;
332 tz->tz_dsttime = vvd->tz_dsttime;
333 }
334 return 0;
335 }
336 return vdso_fallback_gettimeofday(tv, tz);
337}
338int
339gettimeofday(struct __kernel_old_timeval *, struct timezone *)
340 __attribute__((weak, alias("__vdso_gettimeofday")));
341
342notrace int
343__vdso_gettimeofday_stick(struct __kernel_old_timeval *tv, struct timezone *tz)
344{
345 struct vvar_data *vvd = get_vvar_data();
346
347 if (likely(vvd->vclock_mode != VCLOCK_NONE)) {
348 if (likely(tv != NULL)) {
349 union tstv_t {
350 struct __kernel_old_timespec ts;
351 struct __kernel_old_timeval tv;
352 } *tstv = (union tstv_t *) tv;
353 do_realtime_stick(vvd, &tstv->ts);
354 /*
355 * Assign before dividing to ensure that the division is
356 * done in the type of tv_usec, not tv_nsec.
357 *
358 * There cannot be > 1 billion usec in a second:
359 * do_realtime() has already distributed such overflow
360 * into tv_sec. So we can assign it to an int safely.
361 */
362 tstv->tv.tv_usec = tstv->ts.tv_nsec;
363 tstv->tv.tv_usec /= 1000;
364 }
365 if (unlikely(tz != NULL)) {
366 /* Avoid memcpy. Some old compilers fail to inline it */
367 tz->tz_minuteswest = vvd->tz_minuteswest;
368 tz->tz_dsttime = vvd->tz_dsttime;
369 }
370 return 0;
371 }
372 return vdso_fallback_gettimeofday(tv, tz);
373}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2006 Andi Kleen, SUSE Labs.
4 *
5 * Fast user context implementation of clock_gettime, gettimeofday, and time.
6 *
7 * The code should have no internal unresolved relocations.
8 * Check with readelf after changing.
9 * Also alternative() doesn't work.
10 */
11/*
12 * Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved.
13 */
14
15#include <linux/kernel.h>
16#include <linux/time.h>
17#include <linux/string.h>
18#include <asm/io.h>
19#include <asm/unistd.h>
20#include <asm/timex.h>
21#include <asm/clocksource.h>
22#include <asm/vvar.h>
23
24#ifdef CONFIG_SPARC64
25#define SYSCALL_STRING \
26 "ta 0x6d;" \
27 "bcs,a 1f;" \
28 " sub %%g0, %%o0, %%o0;" \
29 "1:"
30#else
31#define SYSCALL_STRING \
32 "ta 0x10;" \
33 "bcs,a 1f;" \
34 " sub %%g0, %%o0, %%o0;" \
35 "1:"
36#endif
37
38#define SYSCALL_CLOBBERS \
39 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
40 "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", \
41 "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23", \
42 "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31", \
43 "f32", "f34", "f36", "f38", "f40", "f42", "f44", "f46", \
44 "f48", "f50", "f52", "f54", "f56", "f58", "f60", "f62", \
45 "cc", "memory"
46
47/*
48 * Compute the vvar page's address in the process address space, and return it
49 * as a pointer to the vvar_data.
50 */
51notrace static __always_inline struct vvar_data *get_vvar_data(void)
52{
53 unsigned long ret;
54
55 /*
56 * vdso data page is the first vDSO page so grab the PC
57 * and move up a page to get to the data page.
58 */
59 __asm__("rd %%pc, %0" : "=r" (ret));
60 ret &= ~(8192 - 1);
61 ret -= 8192;
62
63 return (struct vvar_data *) ret;
64}
65
66notrace static long vdso_fallback_gettime(long clock, struct __kernel_old_timespec *ts)
67{
68 register long num __asm__("g1") = __NR_clock_gettime;
69 register long o0 __asm__("o0") = clock;
70 register long o1 __asm__("o1") = (long) ts;
71
72 __asm__ __volatile__(SYSCALL_STRING : "=r" (o0) : "r" (num),
73 "0" (o0), "r" (o1) : SYSCALL_CLOBBERS);
74 return o0;
75}
76
77notrace static long vdso_fallback_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
78{
79 register long num __asm__("g1") = __NR_gettimeofday;
80 register long o0 __asm__("o0") = (long) tv;
81 register long o1 __asm__("o1") = (long) tz;
82
83 __asm__ __volatile__(SYSCALL_STRING : "=r" (o0) : "r" (num),
84 "0" (o0), "r" (o1) : SYSCALL_CLOBBERS);
85 return o0;
86}
87
88#ifdef CONFIG_SPARC64
89notrace static __always_inline u64 __shr64(u64 val, int amt)
90{
91 return val >> amt;
92}
93
94notrace static __always_inline u64 vread_tick(void)
95{
96 u64 ret;
97
98 __asm__ __volatile__("rd %%tick, %0" : "=r" (ret));
99 return ret;
100}
101
102notrace static __always_inline u64 vread_tick_stick(void)
103{
104 u64 ret;
105
106 __asm__ __volatile__("rd %%asr24, %0" : "=r" (ret));
107 return ret;
108}
109#else
110notrace static __always_inline u64 __shr64(u64 val, int amt)
111{
112 u64 ret;
113
114 __asm__ __volatile__("sllx %H1, 32, %%g1\n\t"
115 "srl %L1, 0, %L1\n\t"
116 "or %%g1, %L1, %%g1\n\t"
117 "srlx %%g1, %2, %L0\n\t"
118 "srlx %L0, 32, %H0"
119 : "=r" (ret)
120 : "r" (val), "r" (amt)
121 : "g1");
122 return ret;
123}
124
125notrace static __always_inline u64 vread_tick(void)
126{
127 register unsigned long long ret asm("o4");
128
129 __asm__ __volatile__("rd %%tick, %L0\n\t"
130 "srlx %L0, 32, %H0"
131 : "=r" (ret));
132 return ret;
133}
134
135notrace static __always_inline u64 vread_tick_stick(void)
136{
137 register unsigned long long ret asm("o4");
138
139 __asm__ __volatile__("rd %%asr24, %L0\n\t"
140 "srlx %L0, 32, %H0"
141 : "=r" (ret));
142 return ret;
143}
144#endif
145
146notrace static __always_inline u64 vgetsns(struct vvar_data *vvar)
147{
148 u64 v;
149 u64 cycles;
150
151 cycles = vread_tick();
152 v = (cycles - vvar->clock.cycle_last) & vvar->clock.mask;
153 return v * vvar->clock.mult;
154}
155
156notrace static __always_inline u64 vgetsns_stick(struct vvar_data *vvar)
157{
158 u64 v;
159 u64 cycles;
160
161 cycles = vread_tick_stick();
162 v = (cycles - vvar->clock.cycle_last) & vvar->clock.mask;
163 return v * vvar->clock.mult;
164}
165
166notrace static __always_inline int do_realtime(struct vvar_data *vvar,
167 struct __kernel_old_timespec *ts)
168{
169 unsigned long seq;
170 u64 ns;
171
172 do {
173 seq = vvar_read_begin(vvar);
174 ts->tv_sec = vvar->wall_time_sec;
175 ns = vvar->wall_time_snsec;
176 ns += vgetsns(vvar);
177 ns = __shr64(ns, vvar->clock.shift);
178 } while (unlikely(vvar_read_retry(vvar, seq)));
179
180 ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
181 ts->tv_nsec = ns;
182
183 return 0;
184}
185
186notrace static __always_inline int do_realtime_stick(struct vvar_data *vvar,
187 struct __kernel_old_timespec *ts)
188{
189 unsigned long seq;
190 u64 ns;
191
192 do {
193 seq = vvar_read_begin(vvar);
194 ts->tv_sec = vvar->wall_time_sec;
195 ns = vvar->wall_time_snsec;
196 ns += vgetsns_stick(vvar);
197 ns = __shr64(ns, vvar->clock.shift);
198 } while (unlikely(vvar_read_retry(vvar, seq)));
199
200 ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
201 ts->tv_nsec = ns;
202
203 return 0;
204}
205
206notrace static __always_inline int do_monotonic(struct vvar_data *vvar,
207 struct __kernel_old_timespec *ts)
208{
209 unsigned long seq;
210 u64 ns;
211
212 do {
213 seq = vvar_read_begin(vvar);
214 ts->tv_sec = vvar->monotonic_time_sec;
215 ns = vvar->monotonic_time_snsec;
216 ns += vgetsns(vvar);
217 ns = __shr64(ns, vvar->clock.shift);
218 } while (unlikely(vvar_read_retry(vvar, seq)));
219
220 ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
221 ts->tv_nsec = ns;
222
223 return 0;
224}
225
226notrace static __always_inline int do_monotonic_stick(struct vvar_data *vvar,
227 struct __kernel_old_timespec *ts)
228{
229 unsigned long seq;
230 u64 ns;
231
232 do {
233 seq = vvar_read_begin(vvar);
234 ts->tv_sec = vvar->monotonic_time_sec;
235 ns = vvar->monotonic_time_snsec;
236 ns += vgetsns_stick(vvar);
237 ns = __shr64(ns, vvar->clock.shift);
238 } while (unlikely(vvar_read_retry(vvar, seq)));
239
240 ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
241 ts->tv_nsec = ns;
242
243 return 0;
244}
245
246notrace static int do_realtime_coarse(struct vvar_data *vvar,
247 struct __kernel_old_timespec *ts)
248{
249 unsigned long seq;
250
251 do {
252 seq = vvar_read_begin(vvar);
253 ts->tv_sec = vvar->wall_time_coarse_sec;
254 ts->tv_nsec = vvar->wall_time_coarse_nsec;
255 } while (unlikely(vvar_read_retry(vvar, seq)));
256 return 0;
257}
258
259notrace static int do_monotonic_coarse(struct vvar_data *vvar,
260 struct __kernel_old_timespec *ts)
261{
262 unsigned long seq;
263
264 do {
265 seq = vvar_read_begin(vvar);
266 ts->tv_sec = vvar->monotonic_time_coarse_sec;
267 ts->tv_nsec = vvar->monotonic_time_coarse_nsec;
268 } while (unlikely(vvar_read_retry(vvar, seq)));
269
270 return 0;
271}
272
273notrace int
274__vdso_clock_gettime(clockid_t clock, struct __kernel_old_timespec *ts)
275{
276 struct vvar_data *vvd = get_vvar_data();
277
278 switch (clock) {
279 case CLOCK_REALTIME:
280 if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
281 break;
282 return do_realtime(vvd, ts);
283 case CLOCK_MONOTONIC:
284 if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
285 break;
286 return do_monotonic(vvd, ts);
287 case CLOCK_REALTIME_COARSE:
288 return do_realtime_coarse(vvd, ts);
289 case CLOCK_MONOTONIC_COARSE:
290 return do_monotonic_coarse(vvd, ts);
291 }
292 /*
293 * Unknown clock ID ? Fall back to the syscall.
294 */
295 return vdso_fallback_gettime(clock, ts);
296}
297int
298clock_gettime(clockid_t, struct __kernel_old_timespec *)
299 __attribute__((weak, alias("__vdso_clock_gettime")));
300
301notrace int
302__vdso_clock_gettime_stick(clockid_t clock, struct __kernel_old_timespec *ts)
303{
304 struct vvar_data *vvd = get_vvar_data();
305
306 switch (clock) {
307 case CLOCK_REALTIME:
308 if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
309 break;
310 return do_realtime_stick(vvd, ts);
311 case CLOCK_MONOTONIC:
312 if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
313 break;
314 return do_monotonic_stick(vvd, ts);
315 case CLOCK_REALTIME_COARSE:
316 return do_realtime_coarse(vvd, ts);
317 case CLOCK_MONOTONIC_COARSE:
318 return do_monotonic_coarse(vvd, ts);
319 }
320 /*
321 * Unknown clock ID ? Fall back to the syscall.
322 */
323 return vdso_fallback_gettime(clock, ts);
324}
325
326notrace int
327__vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
328{
329 struct vvar_data *vvd = get_vvar_data();
330
331 if (likely(vvd->vclock_mode != VCLOCK_NONE)) {
332 if (likely(tv != NULL)) {
333 union tstv_t {
334 struct __kernel_old_timespec ts;
335 struct __kernel_old_timeval tv;
336 } *tstv = (union tstv_t *) tv;
337 do_realtime(vvd, &tstv->ts);
338 /*
339 * Assign before dividing to ensure that the division is
340 * done in the type of tv_usec, not tv_nsec.
341 *
342 * There cannot be > 1 billion usec in a second:
343 * do_realtime() has already distributed such overflow
344 * into tv_sec. So we can assign it to an int safely.
345 */
346 tstv->tv.tv_usec = tstv->ts.tv_nsec;
347 tstv->tv.tv_usec /= 1000;
348 }
349 if (unlikely(tz != NULL)) {
350 /* Avoid memcpy. Some old compilers fail to inline it */
351 tz->tz_minuteswest = vvd->tz_minuteswest;
352 tz->tz_dsttime = vvd->tz_dsttime;
353 }
354 return 0;
355 }
356 return vdso_fallback_gettimeofday(tv, tz);
357}
358int
359gettimeofday(struct __kernel_old_timeval *, struct timezone *)
360 __attribute__((weak, alias("__vdso_gettimeofday")));
361
362notrace int
363__vdso_gettimeofday_stick(struct __kernel_old_timeval *tv, struct timezone *tz)
364{
365 struct vvar_data *vvd = get_vvar_data();
366
367 if (likely(vvd->vclock_mode != VCLOCK_NONE)) {
368 if (likely(tv != NULL)) {
369 union tstv_t {
370 struct __kernel_old_timespec ts;
371 struct __kernel_old_timeval tv;
372 } *tstv = (union tstv_t *) tv;
373 do_realtime_stick(vvd, &tstv->ts);
374 /*
375 * Assign before dividing to ensure that the division is
376 * done in the type of tv_usec, not tv_nsec.
377 *
378 * There cannot be > 1 billion usec in a second:
379 * do_realtime() has already distributed such overflow
380 * into tv_sec. So we can assign it to an int safely.
381 */
382 tstv->tv.tv_usec = tstv->ts.tv_nsec;
383 tstv->tv.tv_usec /= 1000;
384 }
385 if (unlikely(tz != NULL)) {
386 /* Avoid memcpy. Some old compilers fail to inline it */
387 tz->tz_minuteswest = vvd->tz_minuteswest;
388 tz->tz_dsttime = vvd->tz_dsttime;
389 }
390 return 0;
391 }
392 return vdso_fallback_gettimeofday(tv, tz);
393}