diff options
author | Kent Overstreet <kent.overstreet@gmail.com> | 2018-05-17 03:14:09 -0400 |
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committer | Kent Overstreet <kent.overstreet@gmail.com> | 2018-05-17 07:24:39 -0400 |
commit | 62e4df2a38081f62fd1bd657459b7ffb2d4f522c (patch) | |
tree | 9b4ed5d3c597e19894ca77299b53057efe071c50 /include/linux/jiffies.h | |
parent | 426e88e41cdcecd007a689daf4fe432bb61303ec (diff) |
drop dead code
Diffstat (limited to 'include/linux/jiffies.h')
-rw-r--r-- | include/linux/jiffies.h | 403 |
1 files changed, 15 insertions, 388 deletions
diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h index e0dadcf0..9b8dd43d 100644 --- a/include/linux/jiffies.h +++ b/include/linux/jiffies.h @@ -6,111 +6,6 @@ #include <linux/typecheck.h> #include <linux/types.h> -#define HZ 100 - -#define MSEC_PER_SEC 1000L -#define USEC_PER_MSEC 1000L -#define NSEC_PER_USEC 1000L -#define NSEC_PER_MSEC 1000000L -#define USEC_PER_SEC 1000000L -#define NSEC_PER_SEC 1000000000L -#define FSEC_PER_SEC 1000000000000000LL - -/* - * The following defines establish the engineering parameters of the PLL - * model. The HZ variable establishes the timer interrupt frequency, 100 Hz - * for the SunOS kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the - * OSF/1 kernel. The SHIFT_HZ define expresses the same value as the - * nearest power of two in order to avoid hardware multiply operations. - */ -#if HZ >= 12 && HZ < 24 -# define SHIFT_HZ 4 -#elif HZ >= 24 && HZ < 48 -# define SHIFT_HZ 5 -#elif HZ >= 48 && HZ < 96 -# define SHIFT_HZ 6 -#elif HZ >= 96 && HZ < 192 -# define SHIFT_HZ 7 -#elif HZ >= 192 && HZ < 384 -# define SHIFT_HZ 8 -#elif HZ >= 384 && HZ < 768 -# define SHIFT_HZ 9 -#elif HZ >= 768 && HZ < 1536 -# define SHIFT_HZ 10 -#elif HZ >= 1536 && HZ < 3072 -# define SHIFT_HZ 11 -#elif HZ >= 3072 && HZ < 6144 -# define SHIFT_HZ 12 -#elif HZ >= 6144 && HZ < 12288 -# define SHIFT_HZ 13 -#else -# error Invalid value of HZ. -#endif - -/* Suppose we want to divide two numbers NOM and DEN: NOM/DEN, then we can - * improve accuracy by shifting LSH bits, hence calculating: - * (NOM << LSH) / DEN - * This however means trouble for large NOM, because (NOM << LSH) may no - * longer fit in 32 bits. The following way of calculating this gives us - * some slack, under the following conditions: - * - (NOM / DEN) fits in (32 - LSH) bits. - * - (NOM % DEN) fits in (32 - LSH) bits. - */ -#define SH_DIV(NOM,DEN,LSH) ( (((NOM) / (DEN)) << (LSH)) \ - + ((((NOM) % (DEN)) << (LSH)) + (DEN) / 2) / (DEN)) - -/* LATCH is used in the interval timer and ftape setup. */ -#define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */ - -extern int register_refined_jiffies(long clock_tick_rate); - -/* TICK_NSEC is the time between ticks in nsec assuming SHIFTED_HZ */ -#define TICK_NSEC ((NSEC_PER_SEC+HZ/2)/HZ) - -/* TICK_USEC is the time between ticks in usec assuming fake USER_HZ */ -#define TICK_USEC ((1000000UL + USER_HZ/2) / USER_HZ) - -static inline u64 sched_clock(void) -{ - struct timespec ts; - - clock_gettime(CLOCK_MONOTONIC, &ts); - - return ((s64) ts.tv_sec * NSEC_PER_SEC) + ts.tv_nsec; -} - -static inline u64 local_clock(void) -{ - return sched_clock(); -} - -extern unsigned long clock_t_to_jiffies(unsigned long x); -extern u64 jiffies_64_to_clock_t(u64 x); -extern u64 nsec_to_clock_t(u64 x); -extern u64 nsecs_to_jiffies64(u64 n); -extern unsigned long nsecs_to_jiffies(u64 n); - -static inline u64 get_jiffies_64(void) -{ - return nsecs_to_jiffies64(sched_clock()); -} - -#define jiffies_64 get_jiffies_64() -#define jiffies ((unsigned long) get_jiffies_64()) - -/* - * These inlines deal with timer wrapping correctly. You are - * strongly encouraged to use them - * 1. Because people otherwise forget - * 2. Because if the timer wrap changes in future you won't have to - * alter your driver code. - * - * time_after(a,b) returns true if the time a is after time b. - * - * Do this with "<0" and ">=0" to only test the sign of the result. A - * good compiler would generate better code (and a really good compiler - * wouldn't care). Gcc is currently neither. - */ #define time_after(a,b) \ (typecheck(unsigned long, a) && \ typecheck(unsigned long, b) && \ @@ -123,23 +18,14 @@ static inline u64 get_jiffies_64(void) ((long)((a) - (b)) >= 0)) #define time_before_eq(a,b) time_after_eq(b,a) -/* - * Calculate whether a is in the range of [b, c]. - */ #define time_in_range(a,b,c) \ (time_after_eq(a,b) && \ time_before_eq(a,c)) -/* - * Calculate whether a is in the range of [b, c). - */ #define time_in_range_open(a,b,c) \ (time_after_eq(a,b) && \ time_before(a,c)) -/* Same as above, but does so with platform independent 64bit types. - * These must be used when utilizing jiffies_64 (i.e. return value of - * get_jiffies_64() */ #define time_after64(a,b) \ (typecheck(__u64, a) && \ typecheck(__u64, b) && \ @@ -156,301 +42,42 @@ static inline u64 get_jiffies_64(void) (time_after_eq64(a, b) && \ time_before_eq64(a, c)) -/* - * These four macros compare jiffies and 'a' for convenience. - */ - -/* time_is_before_jiffies(a) return true if a is before jiffies */ -#define time_is_before_jiffies(a) time_after(jiffies, a) - -/* time_is_after_jiffies(a) return true if a is after jiffies */ -#define time_is_after_jiffies(a) time_before(jiffies, a) - -/* time_is_before_eq_jiffies(a) return true if a is before or equal to jiffies*/ -#define time_is_before_eq_jiffies(a) time_after_eq(jiffies, a) - -/* time_is_after_eq_jiffies(a) return true if a is after or equal to jiffies*/ -#define time_is_after_eq_jiffies(a) time_before_eq(jiffies, a) - -/* - * Have the 32 bit jiffies value wrap 5 minutes after boot - * so jiffies wrap bugs show up earlier. - */ -#define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ)) - -/* - * Change timeval to jiffies, trying to avoid the - * most obvious overflows.. - * - * And some not so obvious. - * - * Note that we don't want to return LONG_MAX, because - * for various timeout reasons we often end up having - * to wait "jiffies+1" in order to guarantee that we wait - * at _least_ "jiffies" - so "jiffies+1" had better still - * be positive. - */ -#define MAX_JIFFY_OFFSET ((LONG_MAX >> 1)-1) - -extern unsigned long preset_lpj; - -/* - * We want to do realistic conversions of time so we need to use the same - * values the update wall clock code uses as the jiffies size. This value - * is: TICK_NSEC (which is defined in timex.h). This - * is a constant and is in nanoseconds. We will use scaled math - * with a set of scales defined here as SEC_JIFFIE_SC, USEC_JIFFIE_SC and - * NSEC_JIFFIE_SC. Note that these defines contain nothing but - * constants and so are computed at compile time. SHIFT_HZ (computed in - * timex.h) adjusts the scaling for different HZ values. - - * Scaled math??? What is that? - * - * Scaled math is a way to do integer math on values that would, - * otherwise, either overflow, underflow, or cause undesired div - * instructions to appear in the execution path. In short, we "scale" - * up the operands so they take more bits (more precision, less - * underflow), do the desired operation and then "scale" the result back - * by the same amount. If we do the scaling by shifting we avoid the - * costly mpy and the dastardly div instructions. - - * Suppose, for example, we want to convert from seconds to jiffies - * where jiffies is defined in nanoseconds as NSEC_PER_JIFFIE. The - * simple math is: jiff = (sec * NSEC_PER_SEC) / NSEC_PER_JIFFIE; We - * observe that (NSEC_PER_SEC / NSEC_PER_JIFFIE) is a constant which we - * might calculate at compile time, however, the result will only have - * about 3-4 bits of precision (less for smaller values of HZ). - * - * So, we scale as follows: - * jiff = (sec) * (NSEC_PER_SEC / NSEC_PER_JIFFIE); - * jiff = ((sec) * ((NSEC_PER_SEC * SCALE)/ NSEC_PER_JIFFIE)) / SCALE; - * Then we make SCALE a power of two so: - * jiff = ((sec) * ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE)) >> SCALE; - * Now we define: - * #define SEC_CONV = ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE)) - * jiff = (sec * SEC_CONV) >> SCALE; - * - * Often the math we use will expand beyond 32-bits so we tell C how to - * do this and pass the 64-bit result of the mpy through the ">> SCALE" - * which should take the result back to 32-bits. We want this expansion - * to capture as much precision as possible. At the same time we don't - * want to overflow so we pick the SCALE to avoid this. In this file, - * that means using a different scale for each range of HZ values (as - * defined in timex.h). - * - * For those who want to know, gcc will give a 64-bit result from a "*" - * operator if the result is a long long AND at least one of the - * operands is cast to long long (usually just prior to the "*" so as - * not to confuse it into thinking it really has a 64-bit operand, - * which, buy the way, it can do, but it takes more code and at least 2 - * mpys). - - * We also need to be aware that one second in nanoseconds is only a - * couple of bits away from overflowing a 32-bit word, so we MUST use - * 64-bits to get the full range time in nanoseconds. - - */ - -/* - * Here are the scales we will use. One for seconds, nanoseconds and - * microseconds. - * - * Within the limits of cpp we do a rough cut at the SEC_JIFFIE_SC and - * check if the sign bit is set. If not, we bump the shift count by 1. - * (Gets an extra bit of precision where we can use it.) - * We know it is set for HZ = 1024 and HZ = 100 not for 1000. - * Haven't tested others. - - * Limits of cpp (for #if expressions) only long (no long long), but - * then we only need the most signicant bit. - */ - -#define SEC_JIFFIE_SC (31 - SHIFT_HZ) -#if !((((NSEC_PER_SEC << 2) / TICK_NSEC) << (SEC_JIFFIE_SC - 2)) & 0x80000000) -#undef SEC_JIFFIE_SC -#define SEC_JIFFIE_SC (32 - SHIFT_HZ) -#endif -#define NSEC_JIFFIE_SC (SEC_JIFFIE_SC + 29) -#define SEC_CONVERSION ((unsigned long)((((u64)NSEC_PER_SEC << SEC_JIFFIE_SC) +\ - TICK_NSEC -1) / (u64)TICK_NSEC)) - -#define NSEC_CONVERSION ((unsigned long)((((u64)1 << NSEC_JIFFIE_SC) +\ - TICK_NSEC -1) / (u64)TICK_NSEC)) -/* - * The maximum jiffie value is (MAX_INT >> 1). Here we translate that - * into seconds. The 64-bit case will overflow if we are not careful, - * so use the messy SH_DIV macro to do it. Still all constants. - */ -#if BITS_PER_LONG < 64 -# define MAX_SEC_IN_JIFFIES \ - (long)((u64)((u64)MAX_JIFFY_OFFSET * TICK_NSEC) / NSEC_PER_SEC) -#else /* take care of overflow on 64 bits machines */ -# define MAX_SEC_IN_JIFFIES \ - (SH_DIV((MAX_JIFFY_OFFSET >> SEC_JIFFIE_SC) * TICK_NSEC, NSEC_PER_SEC, 1) - 1) - -#endif - -/* - * Convert various time units to each other: - */ -extern unsigned int jiffies_to_msecs(const unsigned long j); -extern unsigned int jiffies_to_usecs(const unsigned long j); +#define HZ 1000 static inline u64 jiffies_to_nsecs(const unsigned long j) { - return (u64)jiffies_to_usecs(j) * NSEC_PER_USEC; + return (u64)j * NSEC_PER_MSEC; } -extern unsigned long __msecs_to_jiffies(const unsigned int m); -#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) -/* - * HZ is equal to or smaller than 1000, and 1000 is a nice round - * multiple of HZ, divide with the factor between them, but round - * upwards: - */ -static inline unsigned long _msecs_to_jiffies(const unsigned int m) +static inline unsigned jiffies_to_msecs(const unsigned long j) { - return (m + (MSEC_PER_SEC / HZ) - 1) / (MSEC_PER_SEC / HZ); + return j; } -#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) -/* - * HZ is larger than 1000, and HZ is a nice round multiple of 1000 - - * simply multiply with the factor between them. - * - * But first make sure the multiplication result cannot overflow: - */ -static inline unsigned long _msecs_to_jiffies(const unsigned int m) -{ - if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) - return MAX_JIFFY_OFFSET; - return m * (HZ / MSEC_PER_SEC); -} -#else -/* - * Generic case - multiply, round and divide. But first check that if - * we are doing a net multiplication, that we wouldn't overflow: - */ -static inline unsigned long _msecs_to_jiffies(const unsigned int m) -{ - if (HZ > MSEC_PER_SEC && m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) - return MAX_JIFFY_OFFSET; - return (MSEC_TO_HZ_MUL32 * m + MSEC_TO_HZ_ADJ32) >> MSEC_TO_HZ_SHR32; -} -#endif -/** - * msecs_to_jiffies: - convert milliseconds to jiffies - * @m: time in milliseconds - * - * conversion is done as follows: - * - * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) - * - * - 'too large' values [that would result in larger than - * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. - * - * - all other values are converted to jiffies by either multiplying - * the input value by a factor or dividing it with a factor and - * handling any 32-bit overflows. - * for the details see __msecs_to_jiffies() - * - * msecs_to_jiffies() checks for the passed in value being a constant - * via __builtin_constant_p() allowing gcc to eliminate most of the - * code, __msecs_to_jiffies() is called if the value passed does not - * allow constant folding and the actual conversion must be done at - * runtime. - * the HZ range specific helpers _msecs_to_jiffies() are called both - * directly here and from __msecs_to_jiffies() in the case where - * constant folding is not possible. - */ -static __always_inline unsigned long msecs_to_jiffies(const unsigned int m) +static inline unsigned long msecs_to_jiffies(const unsigned int m) { - if (__builtin_constant_p(m)) { - if ((int)m < 0) - return MAX_JIFFY_OFFSET; - return _msecs_to_jiffies(m); - } else { - return __msecs_to_jiffies(m); - } + return m; } -extern unsigned long __usecs_to_jiffies(const unsigned int u); -#if !(USEC_PER_SEC % HZ) -static inline unsigned long _usecs_to_jiffies(const unsigned int u) +static inline unsigned long nsecs_to_jiffies(u64 n) { - return (u + (USEC_PER_SEC / HZ) - 1) / (USEC_PER_SEC / HZ); + return n / NSEC_PER_MSEC; } -#else -static inline unsigned long _usecs_to_jiffies(const unsigned int u) -{ - return (USEC_TO_HZ_MUL32 * u + USEC_TO_HZ_ADJ32) - >> USEC_TO_HZ_SHR32; -} -#endif -/** - * usecs_to_jiffies: - convert microseconds to jiffies - * @u: time in microseconds - * - * conversion is done as follows: - * - * - 'too large' values [that would result in larger than - * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. - * - * - all other values are converted to jiffies by either multiplying - * the input value by a factor or dividing it with a factor and - * handling any 32-bit overflows as for msecs_to_jiffies. - * - * usecs_to_jiffies() checks for the passed in value being a constant - * via __builtin_constant_p() allowing gcc to eliminate most of the - * code, __usecs_to_jiffies() is called if the value passed does not - * allow constant folding and the actual conversion must be done at - * runtime. - * the HZ range specific helpers _usecs_to_jiffies() are called both - * directly here and from __msecs_to_jiffies() in the case where - * constant folding is not possible. - */ -static __always_inline unsigned long usecs_to_jiffies(const unsigned int u) -{ - if (__builtin_constant_p(u)) { - if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) - return MAX_JIFFY_OFFSET; - return _usecs_to_jiffies(u); - } else { - return __usecs_to_jiffies(u); - } -} - -extern unsigned long timespec64_to_jiffies(const struct timespec64 *value); - -extern void jiffies_to_timespec64(const unsigned long, - struct timespec64 *value); -static inline unsigned long timespec_to_jiffies(const struct timespec *value) +static inline u64 sched_clock(void) { - struct timespec64 ts = timespec_to_timespec64(*value); - - return timespec64_to_jiffies(&ts); -} + struct timespec ts; -static inline void jiffies_to_timespec(const unsigned long j, - struct timespec *value) -{ - struct timespec64 ts; + clock_gettime(CLOCK_MONOTONIC, &ts); - jiffies_to_timespec64(j, &ts); - *value = timespec64_to_timespec(ts); + return ((s64) ts.tv_sec * NSEC_PER_SEC) + ts.tv_nsec; } -extern unsigned long timeval_to_jiffies(const struct timeval *value); -extern void jiffies_to_timeval(const unsigned long j, - struct timeval *value); - -extern clock_t jiffies_to_clock_t(unsigned long x); -static inline clock_t jiffies_delta_to_clock_t(long delta) +static inline u64 local_clock(void) { - return jiffies_to_clock_t(max(0L, delta)); + return sched_clock(); } -#define TIMESTAMP_SIZE 30 +#define jiffies nsecs_to_jiffies(sched_clock()) #endif |