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Diffstat (limited to 'ANDROID_3.4.5/include/linux/jiffies.h')
| -rw-r--r-- | ANDROID_3.4.5/include/linux/jiffies.h | 315 |
1 files changed, 0 insertions, 315 deletions
diff --git a/ANDROID_3.4.5/include/linux/jiffies.h b/ANDROID_3.4.5/include/linux/jiffies.h deleted file mode 100644 index 265e2c3c..00000000 --- a/ANDROID_3.4.5/include/linux/jiffies.h +++ /dev/null @@ -1,315 +0,0 @@ -#ifndef _LINUX_JIFFIES_H -#define _LINUX_JIFFIES_H - -#include <linux/math64.h> -#include <linux/kernel.h> -#include <linux/types.h> -#include <linux/time.h> -#include <linux/timex.h> -#include <asm/param.h> /* for HZ */ - -/* - * 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 - -/* LATCH is used in the interval timer and ftape setup. */ -#define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */ - -/* 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)) - -/* HZ is the requested value. ACTHZ is actual HZ ("<< 8" is for accuracy) */ -#define ACTHZ (SH_DIV (CLOCK_TICK_RATE, LATCH, 8)) - -/* TICK_NSEC is the time between ticks in nsec assuming real ACTHZ */ -#define TICK_NSEC (SH_DIV (1000000UL * 1000, ACTHZ, 8)) - -/* TICK_USEC is the time between ticks in usec assuming fake USER_HZ */ -#define TICK_USEC ((1000000UL + USER_HZ/2) / USER_HZ) - -/* TICK_USEC_TO_NSEC is the time between ticks in nsec assuming real ACTHZ and */ -/* a value TUSEC for TICK_USEC (can be set bij adjtimex) */ -#define TICK_USEC_TO_NSEC(TUSEC) (SH_DIV (TUSEC * USER_HZ * 1000, ACTHZ, 8)) - -/* some arch's have a small-data section that can be accessed register-relative - * but that can only take up to, say, 4-byte variables. jiffies being part of - * an 8-byte variable may not be correctly accessed unless we force the issue - */ -#define __jiffy_data __attribute__((section(".data"))) - -/* - * The 64-bit value is not atomic - you MUST NOT read it - * without sampling the sequence number in xtime_lock. - * get_jiffies_64() will do this for you as appropriate. - */ -extern u64 __jiffy_data jiffies_64; -extern unsigned long volatile __jiffy_data jiffies; - -#if (BITS_PER_LONG < 64) -u64 get_jiffies_64(void); -#else -static inline u64 get_jiffies_64(void) -{ - return (u64)jiffies; -} -#endif - -/* - * 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) && \ - ((long)(b) - (long)(a) < 0)) -#define time_before(a,b) time_after(b,a) - -#define time_after_eq(a,b) \ - (typecheck(unsigned long, a) && \ - typecheck(unsigned long, b) && \ - ((long)(a) - (long)(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) && \ - ((__s64)(b) - (__s64)(a) < 0)) -#define time_before64(a,b) time_after64(b,a) - -#define time_after_eq64(a,b) \ - (typecheck(__u64, a) && \ - typecheck(__u64, b) && \ - ((__s64)(a) - (__s64)(b) >= 0)) -#define time_before_eq64(a,b) time_after_eq64(b,a) - -/* - * 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 USEC_JIFFIE_SC (SEC_JIFFIE_SC + 19) -#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)) -#define USEC_CONVERSION \ - ((unsigned long)((((u64)NSEC_PER_USEC << USEC_JIFFIE_SC) +\ - TICK_NSEC -1) / (u64)TICK_NSEC)) -/* - * USEC_ROUND is used in the timeval to jiffie conversion. See there - * for more details. It is the scaled resolution rounding value. Note - * that it is a 64-bit value. Since, when it is applied, we are already - * in jiffies (albit scaled), it is nothing but the bits we will shift - * off. - */ -#define USEC_ROUND (u64)(((u64)1 << USEC_JIFFIE_SC) - 1) -/* - * 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); -extern unsigned long msecs_to_jiffies(const unsigned int m); -extern unsigned long usecs_to_jiffies(const unsigned int u); -extern unsigned long timespec_to_jiffies(const struct timespec *value); -extern void jiffies_to_timespec(const unsigned long jiffies, - struct timespec *value); -extern unsigned long timeval_to_jiffies(const struct timeval *value); -extern void jiffies_to_timeval(const unsigned long jiffies, - struct timeval *value); -extern clock_t jiffies_to_clock_t(unsigned long x); -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); - -#define TIMESTAMP_SIZE 30 - -#endif |