-
Notifications
You must be signed in to change notification settings - Fork 326
/
exfat_oal.c
196 lines (168 loc) · 6.16 KB
/
exfat_oal.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
/* Some of the source code in this file came from "linux/fs/fat/misc.c". */
/*
* linux/fs/fat/misc.c
*
* Written 1992,1993 by Werner Almesberger
* 22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980
* and date_dos2unix for date==0 by Igor Zhbanov([email protected])
*/
/*
* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
/************************************************************************/
/* */
/* PROJECT : exFAT & FAT12/16/32 File System */
/* FILE : exfat_oal.c */
/* PURPOSE : exFAT OS Adaptation Layer */
/* (Semaphore Functions & Real-Time Clock Functions) */
/* */
/*----------------------------------------------------------------------*/
/* NOTES */
/* */
/*----------------------------------------------------------------------*/
/* REVISION HISTORY (Ver 0.9) */
/* */
/* - 2010.11.15 [Joosun Hahn] : first writing */
/* */
/************************************************************************/
#include <linux/semaphore.h>
#include <linux/time.h>
#include "exfat_config.h"
#include "exfat_api.h"
#include "exfat_oal.h"
/*======================================================================*/
/* */
/* SEMAPHORE FUNCTIONS */
/* */
/*======================================================================*/
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,36)
DECLARE_MUTEX(z_sem);
#else
DEFINE_SEMAPHORE(z_sem);
#endif
s32 sm_init(struct semaphore *sm)
{
sema_init(sm, 1);
return 0;
} /* end of sm_init */
s32 sm_P(struct semaphore *sm)
{
down(sm);
return 0;
} /* end of sm_P */
void sm_V(struct semaphore *sm)
{
up(sm);
} /* end of sm_V */
/*======================================================================*/
/* */
/* REAL-TIME CLOCK FUNCTIONS */
/* */
/*======================================================================*/
extern struct timezone sys_tz;
/*
* The epoch of FAT timestamp is 1980.
* : bits : value
* date: 0 - 4: day (1 - 31)
* date: 5 - 8: month (1 - 12)
* date: 9 - 15: year (0 - 127) from 1980
* time: 0 - 4: sec (0 - 29) 2sec counts
* time: 5 - 10: min (0 - 59)
* time: 11 - 15: hour (0 - 23)
*/
#define UNIX_SECS_1980 315532800L
#if BITS_PER_LONG == 64
#define UNIX_SECS_2108 4354819200L
#endif
/* days between 1.1.70 and 1.1.80 (2 leap days) */
#define DAYS_DELTA_DECADE (365 * 10 + 2)
/* 120 (2100 - 1980) isn't leap year */
#define NO_LEAP_YEAR_2100 (120)
#define IS_LEAP_YEAR(y) (!((y) & 3) && (y) != NO_LEAP_YEAR_2100)
#define SECS_PER_MIN (60)
#define SECS_PER_HOUR (60 * SECS_PER_MIN)
#define SECS_PER_DAY (24 * SECS_PER_HOUR)
#define MAKE_LEAP_YEAR(leap_year, year) \
do { \
if (unlikely(year > NO_LEAP_YEAR_2100)) \
leap_year = ((year + 3) / 4) - 1; \
else \
leap_year = ((year + 3) / 4); \
} while (0)
/* Linear day numbers of the respective 1sts in non-leap years. */
static time_t accum_days_in_year[] = {
/* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec */
0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
};
TIMESTAMP_T *tm_current(TIMESTAMP_T *tp)
{
struct timespec ts;
time_t second, day, leap_day, month, year;
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,8,0)
ts = CURRENT_TIME_SEC;
#else
ktime_get_real_ts(&ts);
#endif
second = ts.tv_sec;
second -= sys_tz.tz_minuteswest * SECS_PER_MIN;
/* Jan 1 GMT 00:00:00 1980. But what about another time zone? */
if (second < UNIX_SECS_1980) {
tp->sec = 0;
tp->min = 0;
tp->hour = 0;
tp->day = 1;
tp->mon = 1;
tp->year = 0;
return tp;
}
#if BITS_PER_LONG == 64
if (second >= UNIX_SECS_2108) {
tp->sec = 59;
tp->min = 59;
tp->hour = 23;
tp->day = 31;
tp->mon = 12;
tp->year = 127;
return tp;
}
#endif
day = second / SECS_PER_DAY - DAYS_DELTA_DECADE;
year = day / 365;
MAKE_LEAP_YEAR(leap_day, year);
if (year * 365 + leap_day > day)
year--;
MAKE_LEAP_YEAR(leap_day, year);
day -= year * 365 + leap_day;
if (IS_LEAP_YEAR(year) && day == accum_days_in_year[3]) {
month = 2;
} else {
if (IS_LEAP_YEAR(year) && day > accum_days_in_year[3])
day--;
for (month = 1; month < 12; month++) {
if (accum_days_in_year[month + 1] > day)
break;
}
}
day -= accum_days_in_year[month];
tp->sec = second % SECS_PER_MIN;
tp->min = (second / SECS_PER_MIN) % 60;
tp->hour = (second / SECS_PER_HOUR) % 24;
tp->day = day + 1;
tp->mon = month;
tp->year = year;
return tp;
} /* end of tm_current */