1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <string.h>
35 #include <stdio.h>
36 #include <unistd.h>
37 #include <inttypes.h>
38 #include <sys/types.h>
39 #include <errno.h>
40 
41 #include <rte_common.h>
42 #include <rte_log.h>
43 #include <rte_cycles.h>
44 #include <rte_pause.h>
45 
46 #include "eal_private.h"
47 
48 /* The frequency of the RDTSC timer resolution */
49 static uint64_t eal_tsc_resolution_hz;
50 
51 /* Pointer to user delay function */
52 void (*rte_delay_us)(unsigned int) = NULL;
53 
54 void
55 rte_delay_us_block(unsigned int us)
56 {
57 	const uint64_t start = rte_get_timer_cycles();
58 	const uint64_t ticks = (uint64_t)us * rte_get_timer_hz() / 1E6;
59 	while ((rte_get_timer_cycles() - start) < ticks)
60 		rte_pause();
61 }
62 
63 uint64_t
64 rte_get_tsc_hz(void)
65 {
66 	return eal_tsc_resolution_hz;
67 }
68 
69 static uint64_t
70 estimate_tsc_freq(void)
71 {
72 	RTE_LOG(WARNING, EAL, "WARNING: TSC frequency estimated roughly"
73 		" - clock timings may be less accurate.\n");
74 	/* assume that the sleep(1) will sleep for 1 second */
75 	uint64_t start = rte_rdtsc();
76 	sleep(1);
77 	return rte_rdtsc() - start;
78 }
79 
80 void
81 set_tsc_freq(void)
82 {
83 	uint64_t freq;
84 
85 	freq = get_tsc_freq_arch();
86 	if (!freq)
87 		freq = get_tsc_freq();
88 	if (!freq)
89 		freq = estimate_tsc_freq();
90 
91 	RTE_LOG(DEBUG, EAL, "TSC frequency is ~%" PRIu64 " KHz\n", freq / 1000);
92 	eal_tsc_resolution_hz = freq;
93 }
94 
95 void rte_delay_us_callback_register(void (*userfunc)(unsigned int))
96 {
97 	rte_delay_us = userfunc;
98 }
99 
100 RTE_INIT(rte_timer_init)
101 {
102 	/* set rte_delay_us_block as a delay function */
103 	rte_delay_us_callback_register(rte_delay_us_block);
104 }
105