![Arnd Bergmann](/assets/img/avatar_default.png)
At this point, we have converted most of the kernel to use timespec64 consistently in place of timespec, so it seems it's time to make timespec64 the native structure and define timespec in terms of that one on 64-bit architectures. Starting with gcc-5, the compiler can completely optimize away the timespec_to_timespec64 and timespec64_to_timespec functions on 64-bit architectures. With older compilers, we introduce a couple of extra copies of local variables, but those are easily avoided by using the timespec64 based interfaces consistently, as we do in most of the important code paths already. The main upside of removing the hack is that printing the tv_sec field of a timespec64 structure can now use the %lld format string on all architectures without a cast to time64_t. Without this patch, the field is a 'long' type and would have to be printed using %ld on 64-bit architectures. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: y2038@lists.linaro.org Cc: John Stultz <john.stultz@linaro.org> Link: https://lkml.kernel.org/r/20180427134016.2525989-2-arnd@arndb.de
152 lines
3.9 KiB
C
152 lines
3.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_TIME64_H
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#define _LINUX_TIME64_H
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#include <linux/math64.h>
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typedef __s64 time64_t;
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typedef __u64 timeu64_t;
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/* CONFIG_64BIT_TIME enables new 64 bit time_t syscalls in the compat path
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* and 32-bit emulation.
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*/
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#ifndef CONFIG_64BIT_TIME
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#define __kernel_timespec timespec
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#endif
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#include <uapi/linux/time.h>
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struct timespec64 {
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time64_t tv_sec; /* seconds */
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long tv_nsec; /* nanoseconds */
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};
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struct itimerspec64 {
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struct timespec64 it_interval;
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struct timespec64 it_value;
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};
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/* Parameters used to convert the timespec values: */
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#define MSEC_PER_SEC 1000L
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#define USEC_PER_MSEC 1000L
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#define NSEC_PER_USEC 1000L
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#define NSEC_PER_MSEC 1000000L
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#define USEC_PER_SEC 1000000L
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#define NSEC_PER_SEC 1000000000L
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#define FSEC_PER_SEC 1000000000000000LL
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/* Located here for timespec[64]_valid_strict */
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#define TIME64_MAX ((s64)~((u64)1 << 63))
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#define KTIME_MAX ((s64)~((u64)1 << 63))
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#define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC)
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static inline int timespec64_equal(const struct timespec64 *a,
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const struct timespec64 *b)
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{
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return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
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}
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/*
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* lhs < rhs: return <0
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* lhs == rhs: return 0
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* lhs > rhs: return >0
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*/
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static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
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{
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if (lhs->tv_sec < rhs->tv_sec)
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return -1;
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if (lhs->tv_sec > rhs->tv_sec)
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return 1;
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return lhs->tv_nsec - rhs->tv_nsec;
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}
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extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
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static inline struct timespec64 timespec64_add(struct timespec64 lhs,
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struct timespec64 rhs)
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{
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struct timespec64 ts_delta;
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set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
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lhs.tv_nsec + rhs.tv_nsec);
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return ts_delta;
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}
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/*
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* sub = lhs - rhs, in normalized form
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*/
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static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
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struct timespec64 rhs)
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{
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struct timespec64 ts_delta;
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set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
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lhs.tv_nsec - rhs.tv_nsec);
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return ts_delta;
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}
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/*
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* Returns true if the timespec64 is norm, false if denorm:
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*/
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static inline bool timespec64_valid(const struct timespec64 *ts)
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{
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/* Dates before 1970 are bogus */
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if (ts->tv_sec < 0)
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return false;
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/* Can't have more nanoseconds then a second */
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if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
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return false;
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return true;
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}
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static inline bool timespec64_valid_strict(const struct timespec64 *ts)
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{
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if (!timespec64_valid(ts))
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return false;
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/* Disallow values that could overflow ktime_t */
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if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
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return false;
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return true;
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}
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/**
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* timespec64_to_ns - Convert timespec64 to nanoseconds
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* @ts: pointer to the timespec64 variable to be converted
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*
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* Returns the scalar nanosecond representation of the timespec64
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* parameter.
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*/
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static inline s64 timespec64_to_ns(const struct timespec64 *ts)
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{
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return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
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}
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/**
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* ns_to_timespec64 - Convert nanoseconds to timespec64
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* @nsec: the nanoseconds value to be converted
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*
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* Returns the timespec64 representation of the nsec parameter.
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*/
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extern struct timespec64 ns_to_timespec64(const s64 nsec);
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/**
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* timespec64_add_ns - Adds nanoseconds to a timespec64
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* @a: pointer to timespec64 to be incremented
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* @ns: unsigned nanoseconds value to be added
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*
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* This must always be inlined because its used from the x86-64 vdso,
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* which cannot call other kernel functions.
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*/
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static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
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{
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a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
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a->tv_nsec = ns;
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}
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/*
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* timespec64_add_safe assumes both values are positive and checks for
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* overflow. It will return TIME64_MAX in case of overflow.
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*/
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extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
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const struct timespec64 rhs);
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#endif /* _LINUX_TIME64_H */
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