1 /*
2 *
3 * Copyright (C) 2008 Advanced Micro Devices, Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 /**
30 * @file libc/time.c
31 * General time functions
32 */
33
34 #define __STDC_FORMAT_MACROS
35
36 #include <libpayload-config.h>
37 #include <libpayload.h>
38 #if CONFIG(LP_ARCH_X86) && CONFIG(LP_NVRAM)
39 #include <arch/rdtsc.h>
40 #endif
41 #include <commonlib/bsd/gcd.h>
42 #include <inttypes.h>
43
44 extern u32 cpu_khz;
45
46 static struct {
47 u64 ticks;
48 time_t secs;
49 suseconds_t usecs;
50 } clock;
51
update_clock(void)52 static void update_clock(void)
53 {
54 u64 delta = timer_raw_value() - clock.ticks;
55 int secs;
56 static uint64_t ticks_per_sec = 0;
57 static uint64_t ticks_per_usec = 0;
58 if (!ticks_per_sec) {
59 ticks_per_sec = timer_hz();
60 ticks_per_usec = timer_hz() / 1000000;
61 }
62
63 clock.ticks += delta;
64
65 secs = (int) (delta / ticks_per_sec);
66 clock.secs += secs;
67 delta -= (secs * ticks_per_sec);
68 clock.usecs += (int)(delta / ticks_per_usec);
69
70 if (clock.usecs > 1000000) {
71 clock.usecs -= 1000000;
72 clock.secs++;
73 }
74 }
75
76 #if CONFIG(LP_NVRAM)
77
day_of_year(int mon,int day,int year)78 static unsigned int day_of_year(int mon, int day, int year)
79 {
80 static u8 mdays[12] = { 31, 28, 31, 30, 31, 30,
81 31, 31, 30, 31, 30, 31 };
82
83 int i, ret = 0;
84
85 for(i = 0; i < mon; i++) {
86 ret += mdays[i];
87
88 if (i == 1 && (year % 4))
89 ret++;
90 }
91
92 return (ret + day);
93 }
94
gettimeofday_init(void)95 static void gettimeofday_init(void)
96 {
97 int days, delta;
98 struct tm tm;
99
100 rtc_read_clock(&tm);
101 clock.ticks = rdtsc();
102
103 /* Calculate the number of days in the year so far */
104 days = day_of_year(tm.tm_mon, tm.tm_mday, tm.tm_year + 1900);
105
106 delta = tm.tm_year - 70;
107
108 days += (delta * 365);
109
110 /* Figure leap years */
111
112 if (delta > 2)
113 days += (delta - 2) / 4;
114
115 clock.secs = (days * 86400) + (tm.tm_hour * 3600) +
116 (tm.tm_min * 60) + tm.tm_sec;
117 }
118 #else
gettimeofday_init(void)119 static void gettimeofday_init(void)
120 {
121 /* Record the number of ticks */
122 clock.ticks = timer_raw_value();
123 }
124 #endif
125
126 /**
127 * Return the current time expressed as seconds from 00:00:00 UTC, 1 Jan 1970.
128 *
129 * @param tp When not NULL, set this to the current time in seconds.
130 * @return The current time in seconds.
131 */
time(time_t * tp)132 time_t time(time_t *tp)
133 {
134 /*
135 * Call the gtod init when we need it - this keeps the code from
136 * being included in the binary if we don't need it.
137 */
138 if (!clock.ticks)
139 gettimeofday_init();
140
141 update_clock();
142
143 if (tp)
144 *tp = clock.secs;
145
146 return clock.secs;
147 }
148
149 /**
150 * Return the current time broken into a timeval structure.
151 *
152 * @param tv A pointer to a timeval structure.
153 * @param tz Added for compatibility - not used.
154 * @return 0 for success (this function cannot return non-zero currently).
155 */
gettimeofday(struct timeval * tv,void * tz)156 int gettimeofday(struct timeval *tv, void *tz)
157 {
158 tv->tv_sec = time(NULL);
159 tv->tv_usec = clock.usecs;
160
161 return 0;
162 }
163
164 __attribute__((weak))
arch_ndelay(uint64_t ns)165 void arch_ndelay(uint64_t ns)
166 {
167 uint64_t delta = ns * timer_hz() / NSECS_PER_SEC;
168 uint64_t start = timer_raw_value();
169 while (timer_raw_value() - start < delta) ;
170 }
171
timer_us(u64 base)172 u64 timer_us(u64 base)
173 {
174 static u64 hz;
175 static u32 mult = USECS_PER_SEC;
176 u32 div;
177
178 // Only check timer_hz once. Assume it doesn't change.
179 if (hz == 0) {
180 hz = timer_hz();
181 if (hz < mult) {
182 printf("Timer frequency %" PRIu64 " is too low, "
183 "must be at least 1MHz.\n", hz);
184 halt();
185 }
186 div = gcd(hz, mult);
187 hz /= div;
188 mult /= div;
189 }
190
191 return (mult * timer_raw_value()) / hz - base;
192 }
193