jiffies: add kernel-doc for all APIs (6d07a31f) · Commits · jan.koester / Linux

include/linux/jiffies.h

+176 −21

Original line number	Diff line number	Diff line
		@@ -72,9 +72,15 @@ extern int register_refined_jiffies(long clock_tick_rate);
		#endif

		/*
		* The 64-bit value is not atomic - you MUST NOT read it
		* The 64-bit value is not atomic on 32-bit systems - you MUST NOT read it
		* without sampling the sequence number in jiffies_lock.
		* get_jiffies_64() will do this for you as appropriate.
		*
		* jiffies and jiffies_64 are at the same address for little-endian systems
		* and for 64-bit big-endian systems.
		* On 32-bit big-endian systems, jiffies is the lower 32 bits of jiffies_64
		* (i.e., at address @jiffies_64 + 4).
		* See arch/ARCH/kernel/vmlinux.lds.S
		*/
		extern u64 __cacheline_aligned_in_smp jiffies_64;
		extern unsigned long volatile __cacheline_aligned_in_smp __jiffy_arch_data jiffies;
		@@ -82,6 +88,14 @@ extern unsigned long volatile __cacheline_aligned_in_smp __jiffy_arch_data jiffi
		#if (BITS_PER_LONG < 64)
		u64 get_jiffies_64(void);
		#else
		/**
		* get_jiffies_64 - read the 64-bit non-atomic jiffies_64 value
		*
		* When BITS_PER_LONG < 64, this uses sequence number sampling using
		* jiffies_lock to protect the 64-bit read.
		*
		* Return: current 64-bit jiffies value
		*/
		static inline u64 get_jiffies_64(void)
		{
		return (u64)jiffies;
		@@ -90,38 +104,75 @@ static inline u64 get_jiffies_64(void)

		/*
		* These inlines deal with timer wrapping correctly. You are
		* strongly encouraged to use them
		* 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.
		*/

		/**
		* time_after - returns true if the time a is after time b.
		* @a: first comparable as unsigned long
		* @b: second comparable as unsigned long
		*
		* 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.
		*
		* Return: %true is time a is after time b, otherwise %false.
		*/
		#define time_after(a,b) \
		(typecheck(unsigned long, a) && \
		typecheck(unsigned long, b) && \
		((long)((b) - (a)) < 0))
		/**
		* time_before - returns true if the time a is before time b.
		* @a: first comparable as unsigned long
		* @b: second comparable as unsigned long
		*
		* Return: %true is time a is before time b, otherwise %false.
		*/
		#define time_before(a,b) time_after(b,a)

		/**
		* time_after_eq - returns true if the time a is after or the same as time b.
		* @a: first comparable as unsigned long
		* @b: second comparable as unsigned long
		*
		* Return: %true is time a is after or the same as time b, otherwise %false.
		*/
		#define time_after_eq(a,b) \
		(typecheck(unsigned long, a) && \
		typecheck(unsigned long, b) && \
		((long)((a) - (b)) >= 0))
		/**
		* time_before_eq - returns true if the time a is before or the same as time b.
		* @a: first comparable as unsigned long
		* @b: second comparable as unsigned long
		*
		* Return: %true is time a is before or the same as time b, otherwise %false.
		*/
		#define time_before_eq(a,b) time_after_eq(b,a)

		/*
		* Calculate whether a is in the range of [b, c].
		/**
		* time_in_range - Calculate whether a is in the range of [b, c].
		* @a: time to test
		* @b: beginning of the range
		* @c: end of the range
		*
		* Return: %true is time a is in the range [b, c], otherwise %false.
		*/
		#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).
		/**
		* time_in_range_open - Calculate whether a is in the range of [b, c).
		* @a: time to test
		* @b: beginning of the range
		* @c: end of the range
		*
		* Return: %true is time a is in the range [b, c), otherwise %false.
		*/
		#define time_in_range_open(a,b,c) \
		(time_after_eq(a,b) && \
		@@ -129,45 +180,138 @@ static inline u64 get_jiffies_64(void)

		/* 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() */
		* get_jiffies_64()). */

		/**
		* time_after64 - returns true if the time a is after time b.
		* @a: first comparable as __u64
		* @b: second comparable as __u64
		*
		* This must be used when utilizing jiffies_64 (i.e. return value of
		* get_jiffies_64()).
		*
		* Return: %true is time a is after time b, otherwise %false.
		*/
		#define time_after64(a,b) \
		(typecheck(__u64, a) && \
		typecheck(__u64, b) && \
		((__s64)((b) - (a)) < 0))
		/**
		* time_before64 - returns true if the time a is before time b.
		* @a: first comparable as __u64
		* @b: second comparable as __u64
		*
		* This must be used when utilizing jiffies_64 (i.e. return value of
		* get_jiffies_64()).
		*
		* Return: %true is time a is before time b, otherwise %false.
		*/
		#define time_before64(a,b) time_after64(b,a)

		/**
		* time_after_eq64 - returns true if the time a is after or the same as time b.
		* @a: first comparable as __u64
		* @b: second comparable as __u64
		*
		* This must be used when utilizing jiffies_64 (i.e. return value of
		* get_jiffies_64()).
		*
		* Return: %true is time a is after or the same as time b, otherwise %false.
		*/
		#define time_after_eq64(a,b) \
		(typecheck(__u64, a) && \
		typecheck(__u64, b) && \
		((__s64)((a) - (b)) >= 0))
		/**
		* time_before_eq64 - returns true if the time a is before or the same as time b.
		* @a: first comparable as __u64
		* @b: second comparable as __u64
		*
		* This must be used when utilizing jiffies_64 (i.e. return value of
		* get_jiffies_64()).
		*
		* Return: %true is time a is before or the same as time b, otherwise %false.
		*/
		#define time_before_eq64(a,b) time_after_eq64(b,a)

		/**
		* time_in_range64 - Calculate whether a is in the range of [b, c].
		* @a: time to test
		* @b: beginning of the range
		* @c: end of the range
		*
		* Return: %true is time a is in the range [b, c], otherwise %false.
		*/
		#define time_in_range64(a, b, c) \
		(time_after_eq64(a, b) && \
		time_before_eq64(a, c))

		/*
		* These four macros compare jiffies and 'a' for convenience.
		* These eight macros compare jiffies[_64] and 'a' for convenience.
		*/

		/* time_is_before_jiffies(a) return true if a is before jiffies */
		/**
		* time_is_before_jiffies - return true if a is before jiffies
		* @a: time (unsigned long) to compare to jiffies
		*
		* Return: %true is time a is before jiffies, otherwise %false.
		*/
		#define time_is_before_jiffies(a) time_after(jiffies, a)
		/**
		* time_is_before_jiffies64 - return true if a is before jiffies_64
		* @a: time (__u64) to compare to jiffies_64
		*
		* Return: %true is time a is before jiffies_64, otherwise %false.
		*/
		#define time_is_before_jiffies64(a) time_after64(get_jiffies_64(), a)

		/* time_is_after_jiffies(a) return true if a is after jiffies */
		/**
		* time_is_after_jiffies - return true if a is after jiffies
		* @a: time (unsigned long) to compare to jiffies
		*
		* Return: %true is time a is after jiffies, otherwise %false.
		*/
		#define time_is_after_jiffies(a) time_before(jiffies, a)
		/**
		* time_is_after_jiffies64 - return true if a is after jiffies_64
		* @a: time (__u64) to compare to jiffies_64
		*
		* Return: %true is time a is after jiffies_64, otherwise %false.
		*/
		#define time_is_after_jiffies64(a) time_before64(get_jiffies_64(), a)

		/* time_is_before_eq_jiffies(a) return true if a is before or equal to jiffies*/
		/**
		* time_is_before_eq_jiffies - return true if a is before or equal to jiffies
		* @a: time (unsigned long) to compare to jiffies
		*
		* Return: %true is time a is before or the same as jiffies, otherwise %false.
		*/
		#define time_is_before_eq_jiffies(a) time_after_eq(jiffies, a)
		/**
		* time_is_before_eq_jiffies64 - return true if a is before or equal to jiffies_64
		* @a: time (__u64) to compare to jiffies_64
		*
		* Return: %true is time a is before or the same jiffies_64, otherwise %false.
		*/
		#define time_is_before_eq_jiffies64(a) time_after_eq64(get_jiffies_64(), a)

		/* time_is_after_eq_jiffies(a) return true if a is after or equal to jiffies*/
		/**
		* time_is_after_eq_jiffies - return true if a is after or equal to jiffies
		* @a: time (unsigned long) to compare to jiffies
		*
		* Return: %true is time a is after or the same as jiffies, otherwise %false.
		*/
		#define time_is_after_eq_jiffies(a) time_before_eq(jiffies, a)
		/**
		* time_is_after_eq_jiffies64 - return true if a is after or equal to jiffies_64
		* @a: time (__u64) to compare to jiffies_64
		*
		* Return: %true is time a is after or the same as jiffies_64, otherwise %false.
		*/
		#define time_is_after_eq_jiffies64(a) time_before_eq64(get_jiffies_64(), a)

		/*
		* Have the 32 bit jiffies value wrap 5 minutes after boot
		* 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))
		@@ -278,7 +422,7 @@ extern unsigned long preset_lpj;
		#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 */
		#else /* take care of overflow on 64-bit machines */
		# define MAX_SEC_IN_JIFFIES \
		(SH_DIV((MAX_JIFFY_OFFSET >> SEC_JIFFIE_SC) * TICK_NSEC, NSEC_PER_SEC, 1) - 1)

		@@ -290,6 +434,12 @@ extern unsigned long preset_lpj;
		extern unsigned int jiffies_to_msecs(const unsigned long j);
		extern unsigned int jiffies_to_usecs(const unsigned long j);

		/**
		* jiffies_to_nsecs - Convert jiffies to nanoseconds
		* @j: jiffies value
		*
		* Return: nanoseconds value
		*/
		static inline u64 jiffies_to_nsecs(const unsigned long j)
		{
		return (u64)jiffies_to_usecs(j) * NSEC_PER_USEC;
		@@ -353,12 +503,14 @@ static inline unsigned long _msecs_to_jiffies(const unsigned int m)
		*
		* msecs_to_jiffies() checks for the passed in value being a constant
		* via __builtin_constant_p() allowing gcc to eliminate most of the
		* code, __msecs_to_jiffies() is called if the value passed does not
		* code. __msecs_to_jiffies() is called if the value passed does not
		* allow constant folding and the actual conversion must be done at
		* runtime.
		* the HZ range specific helpers _msecs_to_jiffies() are called both
		* The HZ range specific helpers _msecs_to_jiffies() are called both
		* directly here and from __msecs_to_jiffies() in the case where
		* constant folding is not possible.
		*
		* Return: jiffies value
		*/
		static __always_inline unsigned long msecs_to_jiffies(const unsigned int m)
		{
		@@ -400,12 +552,14 @@ static inline unsigned long _usecs_to_jiffies(const unsigned int u)
		*
		* usecs_to_jiffies() checks for the passed in value being a constant
		* via __builtin_constant_p() allowing gcc to eliminate most of the
		* code, __usecs_to_jiffies() is called if the value passed does not
		* code. __usecs_to_jiffies() is called if the value passed does not
		* allow constant folding and the actual conversion must be done at
		* runtime.
		* the HZ range specific helpers _usecs_to_jiffies() are called both
		* The HZ range specific helpers _usecs_to_jiffies() are called both
		* directly here and from __msecs_to_jiffies() in the case where
		* constant folding is not possible.
		*
		* Return: jiffies value
		*/
		static __always_inline unsigned long usecs_to_jiffies(const unsigned int u)
		{
		@@ -422,6 +576,7 @@ extern unsigned long timespec64_to_jiffies(const struct timespec64 *value);
		extern void jiffies_to_timespec64(const unsigned long jiffies,
		struct timespec64 *value);
		extern clock_t jiffies_to_clock_t(unsigned long x);

		static inline clock_t jiffies_delta_to_clock_t(long delta)
		{
		return jiffies_to_clock_t(max(0L, delta));