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34 #define NSEC_PER_SEC 1000000000L
37 * Structure to hold the parameters of a running cycle counter to assist
38 * in converting cycles to nanoseconds.
40 struct rte_timecounter {
41 /** Last cycle counter value read. */
43 /** Nanoseconds count. */
45 /** Bitmask separating nanosecond and sub-nanoseconds. */
47 /** Sub-nanoseconds count. */
49 /** Bitmask for two's complement substraction of non-64 bit counters. */
51 /** Cycle to nanosecond divisor (power of two). */
56 * Converts cyclecounter cycles to nanoseconds.
58 static inline uint64_t
59 rte_cyclecounter_cycles_to_ns(struct rte_timecounter *tc, uint64_t cycles)
63 /* Add fractional nanoseconds. */
64 ns = cycles + tc->nsec_frac;
65 tc->nsec_frac = ns & tc->nsec_mask;
67 /* Shift to get only nanoseconds. */
68 return ns >> tc->cc_shift;
72 * Update the internal nanosecond count in the structure.
74 static inline uint64_t
75 rte_timecounter_update(struct rte_timecounter *tc, uint64_t cycle_now)
77 uint64_t cycle_delta, ns_offset;
79 /* Calculate the delta since the last call. */
80 if (tc->cycle_last <= cycle_now)
81 cycle_delta = (cycle_now - tc->cycle_last) & tc->cc_mask;
83 /* Handle cycle counts that have wrapped around . */
84 cycle_delta = (~(tc->cycle_last - cycle_now) & tc->cc_mask) + 1;
86 /* Convert to nanoseconds. */
87 ns_offset = rte_cyclecounter_cycles_to_ns(tc, cycle_delta);
89 /* Store current cycle counter for next call. */
90 tc->cycle_last = cycle_now;
92 /* Update the nanosecond count. */
93 tc->nsec += ns_offset;
99 * Convert from timespec structure into nanosecond units.
101 static inline uint64_t
102 rte_timespec_to_ns(const struct timespec *ts)
104 return ((uint64_t) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
108 * Convert from nanosecond units into timespec structure.
110 static inline struct timespec
111 rte_ns_to_timespec(uint64_t nsec)
113 struct timespec ts = {0, 0};
118 ts.tv_sec = nsec / NSEC_PER_SEC;
119 ts.tv_nsec = nsec % NSEC_PER_SEC;