Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #ifndef _LINUX_JIFFIES_H |
| 2 | #define _LINUX_JIFFIES_H |
| 3 | |
Roman Zippel | f8bd225 | 2008-05-01 04:34:31 -0700 | [diff] [blame] | 4 | #include <linux/math64.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | #include <linux/kernel.h> |
| 6 | #include <linux/types.h> |
| 7 | #include <linux/time.h> |
| 8 | #include <linux/timex.h> |
| 9 | #include <asm/param.h> /* for HZ */ |
Nicholas Mc Guire | ca42aaf | 2015-05-18 14:19:13 +0200 | [diff] [blame] | 10 | #include <generated/timeconst.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | |
| 12 | /* |
| 13 | * The following defines establish the engineering parameters of the PLL |
| 14 | * model. The HZ variable establishes the timer interrupt frequency, 100 Hz |
| 15 | * for the SunOS kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the |
| 16 | * OSF/1 kernel. The SHIFT_HZ define expresses the same value as the |
| 17 | * nearest power of two in order to avoid hardware multiply operations. |
| 18 | */ |
| 19 | #if HZ >= 12 && HZ < 24 |
| 20 | # define SHIFT_HZ 4 |
| 21 | #elif HZ >= 24 && HZ < 48 |
| 22 | # define SHIFT_HZ 5 |
| 23 | #elif HZ >= 48 && HZ < 96 |
| 24 | # define SHIFT_HZ 6 |
| 25 | #elif HZ >= 96 && HZ < 192 |
| 26 | # define SHIFT_HZ 7 |
| 27 | #elif HZ >= 192 && HZ < 384 |
| 28 | # define SHIFT_HZ 8 |
| 29 | #elif HZ >= 384 && HZ < 768 |
| 30 | # define SHIFT_HZ 9 |
| 31 | #elif HZ >= 768 && HZ < 1536 |
| 32 | # define SHIFT_HZ 10 |
Pavel Machek | e118ade | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 33 | #elif HZ >= 1536 && HZ < 3072 |
| 34 | # define SHIFT_HZ 11 |
| 35 | #elif HZ >= 3072 && HZ < 6144 |
| 36 | # define SHIFT_HZ 12 |
| 37 | #elif HZ >= 6144 && HZ < 12288 |
| 38 | # define SHIFT_HZ 13 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | #else |
Robert P. J. Day | 3767901 | 2008-04-21 22:56:14 +0000 | [diff] [blame] | 40 | # error Invalid value of HZ. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | #endif |
| 42 | |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 43 | /* Suppose we want to divide two numbers NOM and DEN: NOM/DEN, then we can |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | * improve accuracy by shifting LSH bits, hence calculating: |
| 45 | * (NOM << LSH) / DEN |
| 46 | * This however means trouble for large NOM, because (NOM << LSH) may no |
| 47 | * longer fit in 32 bits. The following way of calculating this gives us |
| 48 | * some slack, under the following conditions: |
| 49 | * - (NOM / DEN) fits in (32 - LSH) bits. |
| 50 | * - (NOM % DEN) fits in (32 - LSH) bits. |
| 51 | */ |
Uwe Zeisberger | 0d94df5 | 2006-07-30 03:04:02 -0700 | [diff] [blame] | 52 | #define SH_DIV(NOM,DEN,LSH) ( (((NOM) / (DEN)) << (LSH)) \ |
| 53 | + ((((NOM) % (DEN)) << (LSH)) + (DEN) / 2) / (DEN)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | |
Catalin Marinas | a7ea3bb | 2012-07-27 14:48:09 -0400 | [diff] [blame] | 55 | /* LATCH is used in the interval timer and ftape setup. */ |
Arnd Bergmann | 015a830 | 2012-09-28 23:36:17 +0200 | [diff] [blame] | 56 | #define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | |
John Stultz | b3c869d | 2012-09-04 12:42:27 -0400 | [diff] [blame] | 58 | extern int register_refined_jiffies(long clock_tick_rate); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | |
John Stultz | 02ab20a | 2012-07-27 14:48:10 -0400 | [diff] [blame] | 60 | /* TICK_NSEC is the time between ticks in nsec assuming SHIFTED_HZ */ |
John Stultz | b3c869d | 2012-09-04 12:42:27 -0400 | [diff] [blame] | 61 | #define TICK_NSEC ((NSEC_PER_SEC+HZ/2)/HZ) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | |
| 63 | /* TICK_USEC is the time between ticks in usec assuming fake USER_HZ */ |
| 64 | #define TICK_USEC ((1000000UL + USER_HZ/2) / USER_HZ) |
| 65 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | /* some arch's have a small-data section that can be accessed register-relative |
| 67 | * but that can only take up to, say, 4-byte variables. jiffies being part of |
| 68 | * an 8-byte variable may not be correctly accessed unless we force the issue |
| 69 | */ |
| 70 | #define __jiffy_data __attribute__((section(".data"))) |
| 71 | |
| 72 | /* |
Chase Venters | 98c4f0c | 2006-11-30 04:53:49 +0100 | [diff] [blame] | 73 | * The 64-bit value is not atomic - you MUST NOT read it |
John Stultz | d6ad418 | 2012-02-28 16:50:11 -0800 | [diff] [blame] | 74 | * without sampling the sequence number in jiffies_lock. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | * get_jiffies_64() will do this for you as appropriate. |
| 76 | */ |
| 77 | extern u64 __jiffy_data jiffies_64; |
| 78 | extern unsigned long volatile __jiffy_data jiffies; |
| 79 | |
| 80 | #if (BITS_PER_LONG < 64) |
| 81 | u64 get_jiffies_64(void); |
| 82 | #else |
| 83 | static inline u64 get_jiffies_64(void) |
| 84 | { |
| 85 | return (u64)jiffies; |
| 86 | } |
| 87 | #endif |
| 88 | |
| 89 | /* |
| 90 | * These inlines deal with timer wrapping correctly. You are |
| 91 | * strongly encouraged to use them |
| 92 | * 1. Because people otherwise forget |
| 93 | * 2. Because if the timer wrap changes in future you won't have to |
| 94 | * alter your driver code. |
| 95 | * |
| 96 | * time_after(a,b) returns true if the time a is after time b. |
| 97 | * |
| 98 | * Do this with "<0" and ">=0" to only test the sign of the result. A |
| 99 | * good compiler would generate better code (and a really good compiler |
| 100 | * wouldn't care). Gcc is currently neither. |
| 101 | */ |
| 102 | #define time_after(a,b) \ |
| 103 | (typecheck(unsigned long, a) && \ |
| 104 | typecheck(unsigned long, b) && \ |
Paul E. McKenney | 5a581b3 | 2013-07-27 03:53:54 -0700 | [diff] [blame] | 105 | ((long)((b) - (a)) < 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | #define time_before(a,b) time_after(b,a) |
| 107 | |
| 108 | #define time_after_eq(a,b) \ |
| 109 | (typecheck(unsigned long, a) && \ |
| 110 | typecheck(unsigned long, b) && \ |
Paul E. McKenney | 5a581b3 | 2013-07-27 03:53:54 -0700 | [diff] [blame] | 111 | ((long)((a) - (b)) >= 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | #define time_before_eq(a,b) time_after_eq(b,a) |
| 113 | |
Peter Staubach | 64672d5 | 2008-12-23 15:21:56 -0500 | [diff] [blame] | 114 | /* |
| 115 | * Calculate whether a is in the range of [b, c]. |
| 116 | */ |
Fabio Olive Leite | c7e1596 | 2007-07-26 22:59:00 -0300 | [diff] [blame] | 117 | #define time_in_range(a,b,c) \ |
| 118 | (time_after_eq(a,b) && \ |
| 119 | time_before_eq(a,c)) |
| 120 | |
Peter Staubach | 64672d5 | 2008-12-23 15:21:56 -0500 | [diff] [blame] | 121 | /* |
| 122 | * Calculate whether a is in the range of [b, c). |
| 123 | */ |
| 124 | #define time_in_range_open(a,b,c) \ |
| 125 | (time_after_eq(a,b) && \ |
| 126 | time_before(a,c)) |
| 127 | |
Dmitriy Zavin | 3b17167 | 2006-09-26 10:52:42 +0200 | [diff] [blame] | 128 | /* Same as above, but does so with platform independent 64bit types. |
| 129 | * These must be used when utilizing jiffies_64 (i.e. return value of |
| 130 | * get_jiffies_64() */ |
| 131 | #define time_after64(a,b) \ |
| 132 | (typecheck(__u64, a) && \ |
| 133 | typecheck(__u64, b) && \ |
Paul E. McKenney | 5a581b3 | 2013-07-27 03:53:54 -0700 | [diff] [blame] | 134 | ((__s64)((b) - (a)) < 0)) |
Dmitriy Zavin | 3b17167 | 2006-09-26 10:52:42 +0200 | [diff] [blame] | 135 | #define time_before64(a,b) time_after64(b,a) |
| 136 | |
| 137 | #define time_after_eq64(a,b) \ |
| 138 | (typecheck(__u64, a) && \ |
| 139 | typecheck(__u64, b) && \ |
Paul E. McKenney | 5a581b3 | 2013-07-27 03:53:54 -0700 | [diff] [blame] | 140 | ((__s64)((a) - (b)) >= 0)) |
Dmitriy Zavin | 3b17167 | 2006-09-26 10:52:42 +0200 | [diff] [blame] | 141 | #define time_before_eq64(a,b) time_after_eq64(b,a) |
| 142 | |
Eliezer Tamir | 1bc2774 | 2013-07-02 23:22:47 +0300 | [diff] [blame] | 143 | #define time_in_range64(a, b, c) \ |
| 144 | (time_after_eq64(a, b) && \ |
| 145 | time_before_eq64(a, c)) |
| 146 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | /* |
Dave Young | 3f34d02 | 2008-04-18 13:38:57 -0700 | [diff] [blame] | 148 | * These four macros compare jiffies and 'a' for convenience. |
| 149 | */ |
| 150 | |
| 151 | /* time_is_before_jiffies(a) return true if a is before jiffies */ |
| 152 | #define time_is_before_jiffies(a) time_after(jiffies, a) |
| 153 | |
| 154 | /* time_is_after_jiffies(a) return true if a is after jiffies */ |
| 155 | #define time_is_after_jiffies(a) time_before(jiffies, a) |
| 156 | |
| 157 | /* time_is_before_eq_jiffies(a) return true if a is before or equal to jiffies*/ |
| 158 | #define time_is_before_eq_jiffies(a) time_after_eq(jiffies, a) |
| 159 | |
| 160 | /* time_is_after_eq_jiffies(a) return true if a is after or equal to jiffies*/ |
| 161 | #define time_is_after_eq_jiffies(a) time_before_eq(jiffies, a) |
| 162 | |
| 163 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | * Have the 32 bit jiffies value wrap 5 minutes after boot |
| 165 | * so jiffies wrap bugs show up earlier. |
| 166 | */ |
| 167 | #define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ)) |
| 168 | |
| 169 | /* |
| 170 | * Change timeval to jiffies, trying to avoid the |
| 171 | * most obvious overflows.. |
| 172 | * |
| 173 | * And some not so obvious. |
| 174 | * |
Ingo Molnar | 9f907c0 | 2007-02-16 01:27:29 -0800 | [diff] [blame] | 175 | * Note that we don't want to return LONG_MAX, because |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | * for various timeout reasons we often end up having |
| 177 | * to wait "jiffies+1" in order to guarantee that we wait |
| 178 | * at _least_ "jiffies" - so "jiffies+1" had better still |
| 179 | * be positive. |
| 180 | */ |
Ingo Molnar | 9f907c0 | 2007-02-16 01:27:29 -0800 | [diff] [blame] | 181 | #define MAX_JIFFY_OFFSET ((LONG_MAX >> 1)-1) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | |
Randy Dunlap | bfe8df3 | 2007-10-16 01:23:46 -0700 | [diff] [blame] | 183 | extern unsigned long preset_lpj; |
| 184 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | /* |
| 186 | * We want to do realistic conversions of time so we need to use the same |
| 187 | * values the update wall clock code uses as the jiffies size. This value |
| 188 | * is: TICK_NSEC (which is defined in timex.h). This |
Li Zefan | 3eb0567 | 2008-02-08 04:19:25 -0800 | [diff] [blame] | 189 | * is a constant and is in nanoseconds. We will use scaled math |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | * with a set of scales defined here as SEC_JIFFIE_SC, USEC_JIFFIE_SC and |
| 191 | * NSEC_JIFFIE_SC. Note that these defines contain nothing but |
| 192 | * constants and so are computed at compile time. SHIFT_HZ (computed in |
| 193 | * timex.h) adjusts the scaling for different HZ values. |
| 194 | |
| 195 | * Scaled math??? What is that? |
| 196 | * |
| 197 | * Scaled math is a way to do integer math on values that would, |
| 198 | * otherwise, either overflow, underflow, or cause undesired div |
| 199 | * instructions to appear in the execution path. In short, we "scale" |
| 200 | * up the operands so they take more bits (more precision, less |
| 201 | * underflow), do the desired operation and then "scale" the result back |
| 202 | * by the same amount. If we do the scaling by shifting we avoid the |
| 203 | * costly mpy and the dastardly div instructions. |
| 204 | |
| 205 | * Suppose, for example, we want to convert from seconds to jiffies |
| 206 | * where jiffies is defined in nanoseconds as NSEC_PER_JIFFIE. The |
| 207 | * simple math is: jiff = (sec * NSEC_PER_SEC) / NSEC_PER_JIFFIE; We |
| 208 | * observe that (NSEC_PER_SEC / NSEC_PER_JIFFIE) is a constant which we |
| 209 | * might calculate at compile time, however, the result will only have |
| 210 | * about 3-4 bits of precision (less for smaller values of HZ). |
| 211 | * |
| 212 | * So, we scale as follows: |
| 213 | * jiff = (sec) * (NSEC_PER_SEC / NSEC_PER_JIFFIE); |
| 214 | * jiff = ((sec) * ((NSEC_PER_SEC * SCALE)/ NSEC_PER_JIFFIE)) / SCALE; |
| 215 | * Then we make SCALE a power of two so: |
| 216 | * jiff = ((sec) * ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE)) >> SCALE; |
| 217 | * Now we define: |
| 218 | * #define SEC_CONV = ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE)) |
| 219 | * jiff = (sec * SEC_CONV) >> SCALE; |
| 220 | * |
| 221 | * Often the math we use will expand beyond 32-bits so we tell C how to |
| 222 | * do this and pass the 64-bit result of the mpy through the ">> SCALE" |
| 223 | * which should take the result back to 32-bits. We want this expansion |
| 224 | * to capture as much precision as possible. At the same time we don't |
| 225 | * want to overflow so we pick the SCALE to avoid this. In this file, |
| 226 | * that means using a different scale for each range of HZ values (as |
| 227 | * defined in timex.h). |
| 228 | * |
| 229 | * For those who want to know, gcc will give a 64-bit result from a "*" |
| 230 | * operator if the result is a long long AND at least one of the |
| 231 | * operands is cast to long long (usually just prior to the "*" so as |
| 232 | * not to confuse it into thinking it really has a 64-bit operand, |
Li Zefan | 3eb0567 | 2008-02-08 04:19:25 -0800 | [diff] [blame] | 233 | * which, buy the way, it can do, but it takes more code and at least 2 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | * mpys). |
| 235 | |
| 236 | * We also need to be aware that one second in nanoseconds is only a |
| 237 | * couple of bits away from overflowing a 32-bit word, so we MUST use |
| 238 | * 64-bits to get the full range time in nanoseconds. |
| 239 | |
| 240 | */ |
| 241 | |
| 242 | /* |
| 243 | * Here are the scales we will use. One for seconds, nanoseconds and |
| 244 | * microseconds. |
| 245 | * |
| 246 | * Within the limits of cpp we do a rough cut at the SEC_JIFFIE_SC and |
| 247 | * check if the sign bit is set. If not, we bump the shift count by 1. |
| 248 | * (Gets an extra bit of precision where we can use it.) |
| 249 | * We know it is set for HZ = 1024 and HZ = 100 not for 1000. |
| 250 | * Haven't tested others. |
| 251 | |
| 252 | * Limits of cpp (for #if expressions) only long (no long long), but |
| 253 | * then we only need the most signicant bit. |
| 254 | */ |
| 255 | |
| 256 | #define SEC_JIFFIE_SC (31 - SHIFT_HZ) |
| 257 | #if !((((NSEC_PER_SEC << 2) / TICK_NSEC) << (SEC_JIFFIE_SC - 2)) & 0x80000000) |
| 258 | #undef SEC_JIFFIE_SC |
| 259 | #define SEC_JIFFIE_SC (32 - SHIFT_HZ) |
| 260 | #endif |
| 261 | #define NSEC_JIFFIE_SC (SEC_JIFFIE_SC + 29) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | #define SEC_CONVERSION ((unsigned long)((((u64)NSEC_PER_SEC << SEC_JIFFIE_SC) +\ |
| 263 | TICK_NSEC -1) / (u64)TICK_NSEC)) |
| 264 | |
| 265 | #define NSEC_CONVERSION ((unsigned long)((((u64)1 << NSEC_JIFFIE_SC) +\ |
| 266 | TICK_NSEC -1) / (u64)TICK_NSEC)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | /* |
| 268 | * The maximum jiffie value is (MAX_INT >> 1). Here we translate that |
| 269 | * into seconds. The 64-bit case will overflow if we are not careful, |
| 270 | * so use the messy SH_DIV macro to do it. Still all constants. |
| 271 | */ |
| 272 | #if BITS_PER_LONG < 64 |
| 273 | # define MAX_SEC_IN_JIFFIES \ |
| 274 | (long)((u64)((u64)MAX_JIFFY_OFFSET * TICK_NSEC) / NSEC_PER_SEC) |
| 275 | #else /* take care of overflow on 64 bits machines */ |
| 276 | # define MAX_SEC_IN_JIFFIES \ |
| 277 | (SH_DIV((MAX_JIFFY_OFFSET >> SEC_JIFFIE_SC) * TICK_NSEC, NSEC_PER_SEC, 1) - 1) |
| 278 | |
| 279 | #endif |
| 280 | |
| 281 | /* |
Ingo Molnar | 8b9365d | 2007-02-16 01:27:27 -0800 | [diff] [blame] | 282 | * Convert various time units to each other: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | */ |
Ingo Molnar | 8b9365d | 2007-02-16 01:27:27 -0800 | [diff] [blame] | 284 | extern unsigned int jiffies_to_msecs(const unsigned long j); |
| 285 | extern unsigned int jiffies_to_usecs(const unsigned long j); |
Kevin Hilman | 8fe8ff0 | 2014-01-15 14:51:38 +0100 | [diff] [blame] | 286 | |
| 287 | static inline u64 jiffies_to_nsecs(const unsigned long j) |
| 288 | { |
| 289 | return (u64)jiffies_to_usecs(j) * NSEC_PER_USEC; |
| 290 | } |
| 291 | |
Nicholas Mc Guire | ca42aaf | 2015-05-18 14:19:13 +0200 | [diff] [blame] | 292 | extern unsigned long __msecs_to_jiffies(const unsigned int m); |
| 293 | #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) |
| 294 | /* |
| 295 | * HZ is equal to or smaller than 1000, and 1000 is a nice round |
| 296 | * multiple of HZ, divide with the factor between them, but round |
| 297 | * upwards: |
| 298 | */ |
| 299 | static inline unsigned long _msecs_to_jiffies(const unsigned int m) |
| 300 | { |
Thomas Gleixner | 4e3d9cb | 2015-05-19 17:14:51 +0200 | [diff] [blame] | 301 | return (m + (MSEC_PER_SEC / HZ) - 1) / (MSEC_PER_SEC / HZ); |
Nicholas Mc Guire | ca42aaf | 2015-05-18 14:19:13 +0200 | [diff] [blame] | 302 | } |
| 303 | #elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) |
| 304 | /* |
| 305 | * HZ is larger than 1000, and HZ is a nice round multiple of 1000 - |
| 306 | * simply multiply with the factor between them. |
| 307 | * |
| 308 | * But first make sure the multiplication result cannot overflow: |
| 309 | */ |
| 310 | static inline unsigned long _msecs_to_jiffies(const unsigned int m) |
| 311 | { |
Thomas Gleixner | 4e3d9cb | 2015-05-19 17:14:51 +0200 | [diff] [blame] | 312 | if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) |
| 313 | return MAX_JIFFY_OFFSET; |
| 314 | return m * (HZ / MSEC_PER_SEC); |
Nicholas Mc Guire | ca42aaf | 2015-05-18 14:19:13 +0200 | [diff] [blame] | 315 | } |
| 316 | #else |
| 317 | /* |
| 318 | * Generic case - multiply, round and divide. But first check that if |
| 319 | * we are doing a net multiplication, that we wouldn't overflow: |
| 320 | */ |
| 321 | static inline unsigned long _msecs_to_jiffies(const unsigned int m) |
| 322 | { |
Thomas Gleixner | 4e3d9cb | 2015-05-19 17:14:51 +0200 | [diff] [blame] | 323 | if (HZ > MSEC_PER_SEC && m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) |
| 324 | return MAX_JIFFY_OFFSET; |
Nicholas Mc Guire | ca42aaf | 2015-05-18 14:19:13 +0200 | [diff] [blame] | 325 | |
Thomas Gleixner | 4e3d9cb | 2015-05-19 17:14:51 +0200 | [diff] [blame] | 326 | return (MSEC_TO_HZ_MUL32 * m + MSEC_TO_HZ_ADJ32) >> MSEC_TO_HZ_SHR32; |
Nicholas Mc Guire | ca42aaf | 2015-05-18 14:19:13 +0200 | [diff] [blame] | 327 | } |
| 328 | #endif |
| 329 | /** |
| 330 | * msecs_to_jiffies: - convert milliseconds to jiffies |
| 331 | * @m: time in milliseconds |
| 332 | * |
| 333 | * conversion is done as follows: |
| 334 | * |
| 335 | * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) |
| 336 | * |
| 337 | * - 'too large' values [that would result in larger than |
| 338 | * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. |
| 339 | * |
| 340 | * - all other values are converted to jiffies by either multiplying |
| 341 | * the input value by a factor or dividing it with a factor and |
| 342 | * handling any 32-bit overflows. |
| 343 | * for the details see __msecs_to_jiffies() |
| 344 | * |
Nicholas Mc Guire | daa67b4 | 2015-05-18 14:19:14 +0200 | [diff] [blame] | 345 | * msecs_to_jiffies() checks for the passed in value being a constant |
| 346 | * via __builtin_constant_p() allowing gcc to eliminate most of the |
| 347 | * code, __msecs_to_jiffies() is called if the value passed does not |
| 348 | * allow constant folding and the actual conversion must be done at |
| 349 | * runtime. |
| 350 | * the HZ range specific helpers _msecs_to_jiffies() are called both |
| 351 | * directly here and from __msecs_to_jiffies() in the case where |
| 352 | * constant folding is not possible. |
Nicholas Mc Guire | ca42aaf | 2015-05-18 14:19:13 +0200 | [diff] [blame] | 353 | */ |
| 354 | static inline unsigned long msecs_to_jiffies(const unsigned int m) |
| 355 | { |
Nicholas Mc Guire | daa67b4 | 2015-05-18 14:19:14 +0200 | [diff] [blame] | 356 | if (__builtin_constant_p(m)) { |
| 357 | if ((int)m < 0) |
| 358 | return MAX_JIFFY_OFFSET; |
| 359 | return _msecs_to_jiffies(m); |
| 360 | } else { |
| 361 | return __msecs_to_jiffies(m); |
| 362 | } |
Nicholas Mc Guire | ca42aaf | 2015-05-18 14:19:13 +0200 | [diff] [blame] | 363 | } |
| 364 | |
Nicholas Mc Guire | ae60d6a | 2015-05-28 19:09:55 +0200 | [diff] [blame] | 365 | extern unsigned long __usecs_to_jiffies(const unsigned int u); |
| 366 | #if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ) |
| 367 | static inline unsigned long _usecs_to_jiffies(const unsigned int u) |
| 368 | { |
| 369 | return (u + (USEC_PER_SEC / HZ) - 1) / (USEC_PER_SEC / HZ); |
| 370 | } |
| 371 | #elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC) |
| 372 | static inline unsigned long _usecs_to_jiffies(const unsigned int u) |
| 373 | { |
| 374 | return u * (HZ / USEC_PER_SEC); |
| 375 | } |
| 376 | static inline unsigned long _usecs_to_jiffies(const unsigned int u) |
| 377 | { |
| 378 | #else |
| 379 | static inline unsigned long _usecs_to_jiffies(const unsigned int u) |
| 380 | { |
| 381 | return (USEC_TO_HZ_MUL32 * u + USEC_TO_HZ_ADJ32) |
| 382 | >> USEC_TO_HZ_SHR32; |
| 383 | } |
| 384 | #endif |
| 385 | |
Nicholas Mc Guire | c569a23 | 2015-05-28 19:09:56 +0200 | [diff] [blame] | 386 | /** |
| 387 | * usecs_to_jiffies: - convert microseconds to jiffies |
| 388 | * @u: time in microseconds |
| 389 | * |
| 390 | * conversion is done as follows: |
| 391 | * |
| 392 | * - 'too large' values [that would result in larger than |
| 393 | * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. |
| 394 | * |
| 395 | * - all other values are converted to jiffies by either multiplying |
| 396 | * the input value by a factor or dividing it with a factor and |
| 397 | * handling any 32-bit overflows as for msecs_to_jiffies. |
| 398 | * |
| 399 | * usecs_to_jiffies() checks for the passed in value being a constant |
| 400 | * via __builtin_constant_p() allowing gcc to eliminate most of the |
| 401 | * code, __usecs_to_jiffies() is called if the value passed does not |
| 402 | * allow constant folding and the actual conversion must be done at |
| 403 | * runtime. |
| 404 | * the HZ range specific helpers _usecs_to_jiffies() are called both |
| 405 | * directly here and from __msecs_to_jiffies() in the case where |
| 406 | * constant folding is not possible. |
| 407 | */ |
Nicholas Mc Guire | ae60d6a | 2015-05-28 19:09:55 +0200 | [diff] [blame] | 408 | static inline unsigned long usecs_to_jiffies(const unsigned int u) |
| 409 | { |
Nicholas Mc Guire | c569a23 | 2015-05-28 19:09:56 +0200 | [diff] [blame] | 410 | if (__builtin_constant_p(u)) { |
| 411 | if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) |
| 412 | return MAX_JIFFY_OFFSET; |
| 413 | return _usecs_to_jiffies(u); |
| 414 | } else { |
| 415 | return __usecs_to_jiffies(u); |
| 416 | } |
Nicholas Mc Guire | ae60d6a | 2015-05-28 19:09:55 +0200 | [diff] [blame] | 417 | } |
| 418 | |
Ingo Molnar | 8b9365d | 2007-02-16 01:27:27 -0800 | [diff] [blame] | 419 | extern unsigned long timespec_to_jiffies(const struct timespec *value); |
| 420 | extern void jiffies_to_timespec(const unsigned long jiffies, |
| 421 | struct timespec *value); |
| 422 | extern unsigned long timeval_to_jiffies(const struct timeval *value); |
| 423 | extern void jiffies_to_timeval(const unsigned long jiffies, |
| 424 | struct timeval *value); |
Eric Dumazet | a399a80 | 2012-08-08 21:13:53 +0000 | [diff] [blame] | 425 | |
hank | cbbc719 | 2011-09-20 13:53:39 -0700 | [diff] [blame] | 426 | extern clock_t jiffies_to_clock_t(unsigned long x); |
Eric Dumazet | a399a80 | 2012-08-08 21:13:53 +0000 | [diff] [blame] | 427 | static inline clock_t jiffies_delta_to_clock_t(long delta) |
| 428 | { |
| 429 | return jiffies_to_clock_t(max(0L, delta)); |
| 430 | } |
| 431 | |
Ingo Molnar | 8b9365d | 2007-02-16 01:27:27 -0800 | [diff] [blame] | 432 | extern unsigned long clock_t_to_jiffies(unsigned long x); |
| 433 | extern u64 jiffies_64_to_clock_t(u64 x); |
| 434 | extern u64 nsec_to_clock_t(u64 x); |
Venkatesh Pallipadi | a1dabb6 | 2010-12-21 17:09:01 -0800 | [diff] [blame] | 435 | extern u64 nsecs_to_jiffies64(u64 n); |
Hidetoshi Seto | b7b20df9 | 2009-11-26 14:49:27 +0900 | [diff] [blame] | 436 | extern unsigned long nsecs_to_jiffies(u64 n); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | |
Ingo Molnar | 8b9365d | 2007-02-16 01:27:27 -0800 | [diff] [blame] | 438 | #define TIMESTAMP_SIZE 30 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | |
| 440 | #endif |