linux-stable/include/linux/time.h
Peter Zijlstra 0cd39f4600 locking/seqlock, headers: Untangle the spaghetti monster
By using lockdep_assert_*() from seqlock.h, the spaghetti monster
attacked.

Attack back by reducing seqlock.h dependencies from two key high level headers:

 - <linux/seqlock.h>:               -Remove <linux/ww_mutex.h>
 - <linux/time.h>:                  -Remove <linux/seqlock.h>
 - <linux/sched.h>:                 +Add    <linux/seqlock.h>

The price was to add it to sched.h ...

Core header fallout, we add direct header dependencies instead of gaining them
parasitically from higher level headers:

 - <linux/dynamic_queue_limits.h>:  +Add <asm/bug.h>
 - <linux/hrtimer.h>:               +Add <linux/seqlock.h>
 - <linux/ktime.h>:                 +Add <asm/bug.h>
 - <linux/lockdep.h>:               +Add <linux/smp.h>
 - <linux/sched.h>:                 +Add <linux/seqlock.h>
 - <linux/videodev2.h>:             +Add <linux/kernel.h>

Arch headers fallout:

 - PARISC: <asm/timex.h>:           +Add <asm/special_insns.h>
 - SH:     <asm/io.h>:              +Add <asm/page.h>
 - SPARC:  <asm/timer_64.h>:        +Add <uapi/asm/asi.h>
 - SPARC:  <asm/vvar.h>:            +Add <asm/processor.h>, <asm/barrier.h>
                                    -Remove <linux/seqlock.h>
 - X86:    <asm/fixmap.h>:          +Add <asm/pgtable_types.h>
                                    -Remove <asm/acpi.h>

There's also a bunch of parasitic header dependency fallout in .c files, not listed
separately.

[ mingo: Extended the changelog, split up & fixed the original patch. ]

Co-developed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200804133438.GK2674@hirez.programming.kicks-ass.net
2020-08-06 16:13:13 +02:00

115 lines
3.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_TIME_H
#define _LINUX_TIME_H
# include <linux/cache.h>
# include <linux/math64.h>
# include <linux/time64.h>
extern struct timezone sys_tz;
int get_timespec64(struct timespec64 *ts,
const struct __kernel_timespec __user *uts);
int put_timespec64(const struct timespec64 *ts,
struct __kernel_timespec __user *uts);
int get_itimerspec64(struct itimerspec64 *it,
const struct __kernel_itimerspec __user *uit);
int put_itimerspec64(const struct itimerspec64 *it,
struct __kernel_itimerspec __user *uit);
extern time64_t mktime64(const unsigned int year, const unsigned int mon,
const unsigned int day, const unsigned int hour,
const unsigned int min, const unsigned int sec);
/* Some architectures do not supply their own clocksource.
* This is mainly the case in architectures that get their
* inter-tick times by reading the counter on their interval
* timer. Since these timers wrap every tick, they're not really
* useful as clocksources. Wrapping them to act like one is possible
* but not very efficient. So we provide a callout these arches
* can implement for use with the jiffies clocksource to provide
* finer then tick granular time.
*/
#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
extern u32 (*arch_gettimeoffset)(void);
#endif
#ifdef CONFIG_POSIX_TIMERS
extern void clear_itimer(void);
#else
static inline void clear_itimer(void) {}
#endif
extern long do_utimes(int dfd, const char __user *filename, struct timespec64 *times, int flags);
/*
* Similar to the struct tm in userspace <time.h>, but it needs to be here so
* that the kernel source is self contained.
*/
struct tm {
/*
* the number of seconds after the minute, normally in the range
* 0 to 59, but can be up to 60 to allow for leap seconds
*/
int tm_sec;
/* the number of minutes after the hour, in the range 0 to 59*/
int tm_min;
/* the number of hours past midnight, in the range 0 to 23 */
int tm_hour;
/* the day of the month, in the range 1 to 31 */
int tm_mday;
/* the number of months since January, in the range 0 to 11 */
int tm_mon;
/* the number of years since 1900 */
long tm_year;
/* the number of days since Sunday, in the range 0 to 6 */
int tm_wday;
/* the number of days since January 1, in the range 0 to 365 */
int tm_yday;
};
void time64_to_tm(time64_t totalsecs, int offset, struct tm *result);
# include <linux/time32.h>
static inline bool itimerspec64_valid(const struct itimerspec64 *its)
{
if (!timespec64_valid(&(its->it_interval)) ||
!timespec64_valid(&(its->it_value)))
return false;
return true;
}
/**
* time_after32 - compare two 32-bit relative times
* @a: the time which may be after @b
* @b: the time which may be before @a
*
* time_after32(a, b) returns true if the time @a is after time @b.
* time_before32(b, a) returns true if the time @b is before time @a.
*
* Similar to time_after(), compare two 32-bit timestamps for relative
* times. This is useful for comparing 32-bit seconds values that can't
* be converted to 64-bit values (e.g. due to disk format or wire protocol
* issues) when it is known that the times are less than 68 years apart.
*/
#define time_after32(a, b) ((s32)((u32)(b) - (u32)(a)) < 0)
#define time_before32(b, a) time_after32(a, b)
/**
* time_between32 - check if a 32-bit timestamp is within a given time range
* @t: the time which may be within [l,h]
* @l: the lower bound of the range
* @h: the higher bound of the range
*
* time_before32(t, l, h) returns true if @l <= @t <= @h. All operands are
* treated as 32-bit integers.
*
* Equivalent to !(time_before32(@t, @l) || time_after32(@t, @h)).
*/
#define time_between32(t, l, h) ((u32)(h) - (u32)(l) >= (u32)(t) - (u32)(l))
# include <vdso/time.h>
#endif