#include <linux/kernel.h>
#include <linux/types.h>
-#include <linux/time.h>
-#include <linux/timex.h>
+#include <linux/spinlock.h>
+#include <linux/seqlock.h>
+#include <asm/system.h>
#include <asm/param.h> /* for HZ */
-#include <asm/div64.h>
-
-#ifndef div_long_long_rem
-#define div_long_long_rem(dividend,divisor,remainder) \
-({ \
- u64 result = dividend; \
- *remainder = do_div(result,divisor); \
- result; \
-})
-#endif
-
-/*
- * 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
-#else
-# error You lose.
-#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 devide two numbers NOM and DEN: NOM/DEN, the 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))
/*
* The 64-bit value is not volatile - you MUST NOT read it
((long)(a) - (long)(b) >= 0))
#define time_before_eq(a,b) time_after_eq(b,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 MAX_LONG, 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 ((~0UL >> 1)-1)
-
-/*
- * 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 used 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 take 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 jiffies to milliseconds and back.
- *
- * Avoid unnecessary multiplications/divisions in the
- * two most common HZ cases:
- */
-static inline unsigned int jiffies_to_msecs(const unsigned long j)
-{
-#if HZ <= 1000 && !(1000 % HZ)
- return (1000 / HZ) * j;
-#elif HZ > 1000 && !(HZ % 1000)
- return (j + (HZ / 1000) - 1)/(HZ / 1000);
-#else
- return (j * 1000) / HZ;
-#endif
-}
-
-static inline unsigned int jiffies_to_usecs(const unsigned long j)
-{
-#if HZ <= 1000 && !(1000 % HZ)
- return (1000000 / HZ) * j;
-#elif HZ > 1000 && !(HZ % 1000)
- return (j*1000 + (HZ - 1000))/(HZ / 1000);
-#else
- return (j * 1000000) / HZ;
-#endif
-}
-
-static inline unsigned long msecs_to_jiffies(const unsigned int m)
-{
- if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET))
- return MAX_JIFFY_OFFSET;
-#if HZ <= 1000 && !(1000 % HZ)
- return (m + (1000 / HZ) - 1) / (1000 / HZ);
-#elif HZ > 1000 && !(HZ % 1000)
- return m * (HZ / 1000);
-#else
- return (m * HZ + 999) / 1000;
-#endif
-}
-
-/*
- * The TICK_NSEC - 1 rounds up the value to the next resolution. Note
- * that a remainder subtract here would not do the right thing as the
- * resolution values don't fall on second boundries. I.e. the line:
- * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding.
- *
- * Rather, we just shift the bits off the right.
- *
- * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec
- * value to a scaled second value.
- */
-static __inline__ unsigned long
-timespec_to_jiffies(const struct timespec *value)
-{
- unsigned long sec = value->tv_sec;
- long nsec = value->tv_nsec + TICK_NSEC - 1;
-
- if (sec >= MAX_SEC_IN_JIFFIES){
- sec = MAX_SEC_IN_JIFFIES;
- nsec = 0;
- }
- return (((u64)sec * SEC_CONVERSION) +
- (((u64)nsec * NSEC_CONVERSION) >>
- (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC;
-
-}
-
-static __inline__ void
-jiffies_to_timespec(const unsigned long jiffies, struct timespec *value)
-{
- /*
- * Convert jiffies to nanoseconds and separate with
- * one divide.
- */
- u64 nsec = (u64)jiffies * TICK_NSEC;
- value->tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &value->tv_nsec);
-}
-
-/* Same for "timeval"
- *
- * Well, almost. The problem here is that the real system resolution is
- * in nanoseconds and the value being converted is in micro seconds.
- * Also for some machines (those that use HZ = 1024, in-particular),
- * there is a LARGE error in the tick size in microseconds.
-
- * The solution we use is to do the rounding AFTER we convert the
- * microsecond part. Thus the USEC_ROUND, the bits to be shifted off.
- * Instruction wise, this should cost only an additional add with carry
- * instruction above the way it was done above.
- */
-static __inline__ unsigned long
-timeval_to_jiffies(const struct timeval *value)
-{
- unsigned long sec = value->tv_sec;
- long usec = value->tv_usec;
-
- if (sec >= MAX_SEC_IN_JIFFIES){
- sec = MAX_SEC_IN_JIFFIES;
- usec = 0;
- }
- return (((u64)sec * SEC_CONVERSION) +
- (((u64)usec * USEC_CONVERSION + USEC_ROUND) >>
- (USEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC;
-}
-
-static __inline__ void
-jiffies_to_timeval(const unsigned long jiffies, struct timeval *value)
-{
- /*
- * Convert jiffies to nanoseconds and separate with
- * one divide.
- */
- u64 nsec = (u64)jiffies * TICK_NSEC;
- value->tv_sec = div_long_long_rem(nsec, NSEC_PER_SEC, &value->tv_usec);
- value->tv_usec /= NSEC_PER_USEC;
-}
-
-/*
- * Convert jiffies/jiffies_64 to clock_t and back.
- */
-static inline clock_t jiffies_to_clock_t(long x)
-{
-#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
- return x / (HZ / USER_HZ);
-#else
- u64 tmp = (u64)x * TICK_NSEC;
- do_div(tmp, (NSEC_PER_SEC / USER_HZ));
- return (long)tmp;
-#endif
-}
-
-static inline unsigned long clock_t_to_jiffies(unsigned long x)
-{
-#if (HZ % USER_HZ)==0
- if (x >= ~0UL / (HZ / USER_HZ))
- return ~0UL;
- return x * (HZ / USER_HZ);
-#else
- u64 jif;
-
- /* Don't worry about loss of precision here .. */
- if (x >= ~0UL / HZ * USER_HZ)
- return ~0UL;
-
- /* .. but do try to contain it here */
- jif = x * (u64) HZ;
- do_div(jif, USER_HZ);
- return jif;
-#endif
-}
-
-static inline u64 jiffies_64_to_clock_t(u64 x)
-{
-#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
- do_div(x, HZ / USER_HZ);
-#else
- /*
- * There are better ways that don't overflow early,
- * but even this doesn't overflow in hundreds of years
- * in 64 bits, so..
- */
- x *= TICK_NSEC;
- do_div(x, (NSEC_PER_SEC / USER_HZ));
-#endif
- return x;
-}
-
-static inline u64 nsec_to_clock_t(u64 x)
-{
-#if (NSEC_PER_SEC % USER_HZ) == 0
- do_div(x, (NSEC_PER_SEC / USER_HZ));
-#elif (USER_HZ % 512) == 0
- x *= USER_HZ/512;
- do_div(x, (NSEC_PER_SEC / 512));
-#else
- /*
- * max relative error 5.7e-8 (1.8s per year) for USER_HZ <= 1024,
- * overflow after 64.99 years.
- * exact for HZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ...
- */
- x *= 9;
- do_div(x, (unsigned long)((9ull * NSEC_PER_SEC + (USER_HZ/2))
- / USER_HZ));
-#endif
- return x;
-}
-
#endif
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