1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4 
5 #include <string.h>
6 #include <stdio.h>
7 #include <unistd.h>
8 #include <inttypes.h>
9 #include <sys/types.h>
10 #include <time.h>
11 #include <errno.h>
12 
13 #include <rte_common.h>
14 #include <rte_compat.h>
15 #include <rte_log.h>
16 #include <rte_cycles.h>
17 #include <rte_pause.h>
18 
19 #include "eal_private.h"
20 
21 /* The frequency of the RDTSC timer resolution */
22 static uint64_t eal_tsc_resolution_hz;
23 
24 /* Pointer to user delay function */
25 void (*rte_delay_us)(unsigned int) = NULL;
26 
27 void
28 rte_delay_us_block(unsigned int us)
29 {
30 	const uint64_t start = rte_get_timer_cycles();
31 	const uint64_t ticks = (uint64_t)us * rte_get_timer_hz() / 1E6;
32 	while ((rte_get_timer_cycles() - start) < ticks)
33 		rte_pause();
34 }
35 
36 void __rte_experimental
37 rte_delay_us_sleep(unsigned int us)
38 {
39 	struct timespec wait[2];
40 	int ind = 0;
41 
42 	wait[0].tv_sec = 0;
43 	if (us >= US_PER_S) {
44 		wait[0].tv_sec = us / US_PER_S;
45 		us -= wait[0].tv_sec * US_PER_S;
46 	}
47 	wait[0].tv_nsec = 1000 * us;
48 
49 	while (nanosleep(&wait[ind], &wait[1 - ind]) && errno == EINTR) {
50 		/*
51 		 * Sleep was interrupted. Flip the index, so the 'remainder'
52 		 * will become the 'request' for a next call.
53 		 */
54 		ind = 1 - ind;
55 	}
56 }
57 
58 uint64_t
59 rte_get_tsc_hz(void)
60 {
61 	return eal_tsc_resolution_hz;
62 }
63 
64 static uint64_t
65 estimate_tsc_freq(void)
66 {
67 	RTE_LOG(WARNING, EAL, "WARNING: TSC frequency estimated roughly"
68 		" - clock timings may be less accurate.\n");
69 	/* assume that the sleep(1) will sleep for 1 second */
70 	uint64_t start = rte_rdtsc();
71 	sleep(1);
72 	return rte_rdtsc() - start;
73 }
74 
75 void
76 set_tsc_freq(void)
77 {
78 	uint64_t freq;
79 
80 	freq = get_tsc_freq_arch();
81 	if (!freq)
82 		freq = get_tsc_freq();
83 	if (!freq)
84 		freq = estimate_tsc_freq();
85 
86 	RTE_LOG(DEBUG, EAL, "TSC frequency is ~%" PRIu64 " KHz\n", freq / 1000);
87 	eal_tsc_resolution_hz = freq;
88 }
89 
90 void rte_delay_us_callback_register(void (*userfunc)(unsigned int))
91 {
92 	rte_delay_us = userfunc;
93 }
94 
95 RTE_INIT(rte_timer_init)
96 {
97 	/* set rte_delay_us_block as a delay function */
98 	rte_delay_us_callback_register(rte_delay_us_block);
99 }
100