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40 #define NSEC_PER_SEC 1000000000L
43 * Structure to hold the parameters of a running cycle counter to assist
44 * in converting cycles to nanoseconds.
46 struct rte_timecounter
{
47 /** Last cycle counter value read. */
49 /** Nanoseconds count. */
51 /** Bitmask separating nanosecond and sub-nanoseconds. */
53 /** Sub-nanoseconds count. */
55 /** Bitmask for two's complement substraction of non-64 bit counters. */
57 /** Cycle to nanosecond divisor (power of two). */
62 * Converts cyclecounter cycles to nanoseconds.
64 static inline uint64_t
65 rte_cyclecounter_cycles_to_ns(struct rte_timecounter
*tc
, uint64_t cycles
)
69 /* Add fractional nanoseconds. */
70 ns
= cycles
+ tc
->nsec_frac
;
71 tc
->nsec_frac
= ns
& tc
->nsec_mask
;
73 /* Shift to get only nanoseconds. */
74 return ns
>> tc
->cc_shift
;
78 * Update the internal nanosecond count in the structure.
80 static inline uint64_t
81 rte_timecounter_update(struct rte_timecounter
*tc
, uint64_t cycle_now
)
83 uint64_t cycle_delta
, ns_offset
;
85 /* Calculate the delta since the last call. */
86 if (tc
->cycle_last
<= cycle_now
)
87 cycle_delta
= (cycle_now
- tc
->cycle_last
) & tc
->cc_mask
;
89 /* Handle cycle counts that have wrapped around . */
90 cycle_delta
= (~(tc
->cycle_last
- cycle_now
) & tc
->cc_mask
) + 1;
92 /* Convert to nanoseconds. */
93 ns_offset
= rte_cyclecounter_cycles_to_ns(tc
, cycle_delta
);
95 /* Store current cycle counter for next call. */
96 tc
->cycle_last
= cycle_now
;
98 /* Update the nanosecond count. */
99 tc
->nsec
+= ns_offset
;
105 * Convert from timespec structure into nanosecond units.
107 static inline uint64_t
108 rte_timespec_to_ns(const struct timespec
*ts
)
110 return ((uint64_t) ts
->tv_sec
* NSEC_PER_SEC
) + ts
->tv_nsec
;
114 * Convert from nanosecond units into timespec structure.
116 static inline struct timespec
117 rte_ns_to_timespec(uint64_t nsec
)
119 struct timespec ts
= {0, 0};
124 ts
.tv_sec
= nsec
/ NSEC_PER_SEC
;
125 ts
.tv_nsec
= nsec
% NSEC_PER_SEC
;
130 #endif /* _RTE_TIME_H_ */