Commit 67b3f564 authored by Randy Dunlap's avatar Randy Dunlap Committed by Jonathan Corbet
Browse files

time: add kernel-doc in time.c 



Add kernel-doc for all APIs that do not already have it.

Signed-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Cc: John Stultz <jstultz@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Acked-by: default avatarJohn Stultz <jstultz@google.com>
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20230704052405.5089-3-rdunlap@infradead.org
parent 6d07a31f

kernel/time/time.c

+158 −11
Original line number Diff line number Diff line
@@ -365,11 +365,14 @@ SYSCALL_DEFINE1(adjtimex_time32, struct old_timex32 __user *, utp) 
}

#endif



/*

 * Convert jiffies to milliseconds and back.

/**

 * jiffies_to_msecs - Convert jiffies to milliseconds

 * @j: jiffies value

 *

 * Avoid unnecessary multiplications/divisions in the

 * two most common HZ cases:

 * two most common HZ cases.

 *

 * Return: milliseconds value

 */

unsigned int jiffies_to_msecs(const unsigned long j)

{
@@ -388,6 +391,12 @@ unsigned int jiffies_to_msecs(const unsigned long j) 
}

EXPORT_SYMBOL(jiffies_to_msecs);



/**

 * jiffies_to_usecs - Convert jiffies to microseconds

 * @j: jiffies value

 *

 * Return: microseconds value

 */

unsigned int jiffies_to_usecs(const unsigned long j)

{

	/*
@@ -408,8 +417,15 @@ unsigned int jiffies_to_usecs(const unsigned long j) 
}

EXPORT_SYMBOL(jiffies_to_usecs);



/*

/**

 * mktime64 - Converts date to seconds.

 * @year0: year to convert

 * @mon0: month to convert

 * @day: day to convert

 * @hour: hour to convert

 * @min: minute to convert

 * @sec: second to convert

 *

 * Converts Gregorian date to seconds since 1970-01-01 00:00:00.

 * Assumes input in normal date format, i.e. 1980-12-31 23:59:59

 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
@@ -427,6 +443,8 @@ EXPORT_SYMBOL(jiffies_to_usecs); 
 *

 * An encoding of midnight at the end of the day as 24:00:00 - ie. midnight

 * tomorrow - (allowable under ISO 8601) is supported.

 *

 * Return: seconds since the epoch time for the given input date

 */

time64_t mktime64(const unsigned int year0, const unsigned int mon0,

		const unsigned int day, const unsigned int hour,
@@ -471,8 +489,7 @@ EXPORT_SYMBOL(ns_to_kernel_old_timeval); 
 * Set seconds and nanoseconds field of a timespec variable and

 * normalize to the timespec storage format

 *

 * Note: The tv_nsec part is always in the range of

 *	0 <= tv_nsec < NSEC_PER_SEC

 * Note: The tv_nsec part is always in the range of 0 <= tv_nsec < NSEC_PER_SEC.

 * For negative values only the tv_sec field is negative !

 */

void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec)
@@ -501,7 +518,7 @@ EXPORT_SYMBOL(set_normalized_timespec64); 
 * ns_to_timespec64 - Convert nanoseconds to timespec64

 * @nsec:       the nanoseconds value to be converted

 *

 * Returns the timespec64 representation of the nsec parameter.

 * Return: the timespec64 representation of the nsec parameter.

 */

struct timespec64 ns_to_timespec64(s64 nsec)

{
@@ -548,6 +565,8 @@ EXPORT_SYMBOL(ns_to_timespec64); 
 * runtime.

 * The _msecs_to_jiffies helpers are the HZ dependent conversion

 * routines found in include/linux/jiffies.h

 *

 * Return: jiffies value

 */

unsigned long __msecs_to_jiffies(const unsigned int m)

{
@@ -560,6 +579,12 @@ unsigned long __msecs_to_jiffies(const unsigned int m) 
}

EXPORT_SYMBOL(__msecs_to_jiffies);



/**

 * __usecs_to_jiffies: - convert microseconds to jiffies

 * @u:	time in milliseconds

 *

 * Return: jiffies value

 */

unsigned long __usecs_to_jiffies(const unsigned int u)

{

	if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET))
@@ -568,7 +593,10 @@ unsigned long __usecs_to_jiffies(const unsigned int u) 
}

EXPORT_SYMBOL(__usecs_to_jiffies);



/*

/**

 * timespec64_to_jiffies - convert a timespec64 value to jiffies

 * @value: pointer to &struct timespec64

 *

 * 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 boundaries.  I.e. the line:
@@ -582,8 +610,9 @@ EXPORT_SYMBOL(__usecs_to_jiffies); 
 *

 * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec

 * value to a scaled second value.

 *

 * Return: jiffies value

 */



unsigned long

timespec64_to_jiffies(const struct timespec64 *value)

{
@@ -601,6 +630,11 @@ timespec64_to_jiffies(const struct timespec64 *value) 
}

EXPORT_SYMBOL(timespec64_to_jiffies);



/**

 * jiffies_to_timespec64 - convert jiffies value to &struct timespec64

 * @jiffies: jiffies value

 * @value: pointer to &struct timespec64

 */

void

jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value)

{
@@ -618,6 +652,13 @@ EXPORT_SYMBOL(jiffies_to_timespec64); 
/*

 * Convert jiffies/jiffies_64 to clock_t and back.

 */



/**

 * jiffies_to_clock_t - Convert jiffies to clock_t

 * @x: jiffies value

 *

 * Return: jiffies converted to clock_t (CLOCKS_PER_SEC)

 */

clock_t jiffies_to_clock_t(unsigned long x)

{

#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
@@ -632,6 +673,12 @@ clock_t jiffies_to_clock_t(unsigned long x) 
}

EXPORT_SYMBOL(jiffies_to_clock_t);



/**

 * clock_t_to_jiffies - Convert clock_t to jiffies

 * @x: clock_t value

 *

 * Return: clock_t value converted to jiffies

 */

unsigned long clock_t_to_jiffies(unsigned long x)

{

#if (HZ % USER_HZ)==0
@@ -649,6 +696,12 @@ unsigned long clock_t_to_jiffies(unsigned long x) 
}

EXPORT_SYMBOL(clock_t_to_jiffies);



/**

 * jiffies_64_to_clock_t - Convert jiffies_64 to clock_t

 * @x: jiffies_64 value

 *

 * Return: jiffies_64 value converted to 64-bit "clock_t" (CLOCKS_PER_SEC)

 */

u64 jiffies_64_to_clock_t(u64 x)

{

#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
@@ -671,6 +724,12 @@ u64 jiffies_64_to_clock_t(u64 x) 
}

EXPORT_SYMBOL(jiffies_64_to_clock_t);



/**

 * nsec_to_clock_t - Convert nsec value to clock_t

 * @x: nsec value

 *

 * Return: nsec value converted to 64-bit "clock_t" (CLOCKS_PER_SEC)

 */

u64 nsec_to_clock_t(u64 x)

{

#if (NSEC_PER_SEC % USER_HZ) == 0
@@ -687,6 +746,12 @@ u64 nsec_to_clock_t(u64 x) 
#endif

}



/**

 * jiffies64_to_nsecs - Convert jiffies64 to nanoseconds

 * @j: jiffies64 value

 *

 * Return: nanoseconds value

 */

u64 jiffies64_to_nsecs(u64 j)

{

#if !(NSEC_PER_SEC % HZ)
@@ -697,6 +762,12 @@ u64 jiffies64_to_nsecs(u64 j) 
}

EXPORT_SYMBOL(jiffies64_to_nsecs);



/**

 * jiffies64_to_msecs - Convert jiffies64 to milliseconds

 * @j: jiffies64 value

 *

 * Return: milliseconds value

 */

u64 jiffies64_to_msecs(const u64 j)

{

#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
@@ -719,6 +790,8 @@ EXPORT_SYMBOL(jiffies64_to_msecs); 
 * note:

 *   NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512)

 *   ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years

 *

 * Return: nsecs converted to jiffies64 value

 */

u64 nsecs_to_jiffies64(u64 n)

{
@@ -750,6 +823,8 @@ EXPORT_SYMBOL(nsecs_to_jiffies64); 
 * note:

 *   NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512)

 *   ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years

 *

 * Return: nsecs converted to jiffies value

 */

unsigned long nsecs_to_jiffies(u64 n)

{
@@ -757,10 +832,16 @@ unsigned long nsecs_to_jiffies(u64 n) 
}

EXPORT_SYMBOL_GPL(nsecs_to_jiffies);



/*

 * Add two timespec64 values and do a safety check for overflow.

/**

 * timespec64_add_safe - Add two timespec64 values and do a safety check

 * for overflow.

 * @lhs: first (left) timespec64 to add

 * @rhs: second (right) timespec64 to add

 *

 * It's assumed that both values are valid (>= 0).

 * And, each timespec64 is in normalized form.

 *

 * Return: sum of @lhs + @rhs

 */

struct timespec64 timespec64_add_safe(const struct timespec64 lhs,

				const struct timespec64 rhs)
@@ -778,6 +859,15 @@ struct timespec64 timespec64_add_safe(const struct timespec64 lhs, 
	return res;

}



/**

 * get_timespec64 - get user's time value into kernel space

 * @ts: destination &struct timespec64

 * @uts: user's time value as &struct __kernel_timespec

 *

 * Handles compat or 32-bit modes.

 *

 * Return: %0 on success or negative errno on error

 */

int get_timespec64(struct timespec64 *ts,

		   const struct __kernel_timespec __user *uts)

{
@@ -801,6 +891,14 @@ int get_timespec64(struct timespec64 *ts, 
}

EXPORT_SYMBOL_GPL(get_timespec64);



/**

 * put_timespec64 - convert timespec64 value to __kernel_timespec format and

 * 		    copy the latter to userspace

 * @ts: input &struct timespec64

 * @uts: user's &struct __kernel_timespec

 *

 * Return: %0 on success or negative errno on error

 */

int put_timespec64(const struct timespec64 *ts,

		   struct __kernel_timespec __user *uts)

{
@@ -839,6 +937,15 @@ static int __put_old_timespec32(const struct timespec64 *ts64, 
	return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0;

}



/**

 * get_old_timespec32 - get user's old-format time value into kernel space

 * @ts: destination &struct timespec64

 * @uts: user's old-format time value (&struct old_timespec32)

 *

 * Handles X86_X32_ABI compatibility conversion.

 *

 * Return: %0 on success or negative errno on error

 */

int get_old_timespec32(struct timespec64 *ts, const void __user *uts)

{

	if (COMPAT_USE_64BIT_TIME)
@@ -848,6 +955,16 @@ int get_old_timespec32(struct timespec64 *ts, const void __user *uts) 
}

EXPORT_SYMBOL_GPL(get_old_timespec32);



/**

 * put_old_timespec32 - convert timespec64 value to &struct old_timespec32 and

 * 			copy the latter to userspace

 * @ts: input &struct timespec64

 * @uts: user's &struct old_timespec32

 *

 * Handles X86_X32_ABI compatibility conversion.

 *

 * Return: %0 on success or negative errno on error

 */

int put_old_timespec32(const struct timespec64 *ts, void __user *uts)

{

	if (COMPAT_USE_64BIT_TIME)
@@ -857,6 +974,13 @@ int put_old_timespec32(const struct timespec64 *ts, void __user *uts) 
}

EXPORT_SYMBOL_GPL(put_old_timespec32);



/**

 * get_itimerspec64 - get user's &struct __kernel_itimerspec into kernel space

 * @it: destination &struct itimerspec64

 * @uit: user's &struct __kernel_itimerspec

 *

 * Return: %0 on success or negative errno on error

 */

int get_itimerspec64(struct itimerspec64 *it,

			const struct __kernel_itimerspec __user *uit)

{
@@ -872,6 +996,14 @@ int get_itimerspec64(struct itimerspec64 *it, 
}

EXPORT_SYMBOL_GPL(get_itimerspec64);



/**

 * put_itimerspec64 - convert &struct itimerspec64 to __kernel_itimerspec format

 * 		      and copy the latter to userspace

 * @it: input &struct itimerspec64

 * @uit: user's &struct __kernel_itimerspec

 *

 * Return: %0 on success or negative errno on error

 */

int put_itimerspec64(const struct itimerspec64 *it,

			struct __kernel_itimerspec __user *uit)

{
@@ -887,6 +1019,13 @@ int put_itimerspec64(const struct itimerspec64 *it, 
}

EXPORT_SYMBOL_GPL(put_itimerspec64);



/**

 * get_old_itimerspec32 - get user's &struct old_itimerspec32 into kernel space

 * @its: destination &struct itimerspec64

 * @uits: user's &struct old_itimerspec32

 *

 * Return: %0 on success or negative errno on error

 */

int get_old_itimerspec32(struct itimerspec64 *its,

			const struct old_itimerspec32 __user *uits)

{
@@ -898,6 +1037,14 @@ int get_old_itimerspec32(struct itimerspec64 *its, 
}

EXPORT_SYMBOL_GPL(get_old_itimerspec32);



/**

 * put_old_itimerspec32 - convert &struct itimerspec64 to &struct

 *			  old_itimerspec32 and copy the latter to userspace

 * @its: input &struct itimerspec64

 * @uits: user's &struct old_itimerspec32

 *

 * Return: %0 on success or negative errno on error

 */

int put_old_itimerspec32(const struct itimerspec64 *its,

			struct old_itimerspec32 __user *uits)

{