xref: /dpdk/app/test/test_cycles.c (revision 68a03efeed657e6e05f281479b33b51102797e15)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4 
5 #include <stdio.h>
6 #include <stdint.h>
7 
8 #include <rte_common.h>
9 #include <rte_cycles.h>
10 
11 #include "test.h"
12 
13 #define N 10000
14 
15 /*
16  * Cycles test
17  * ===========
18  *
19  * - Loop N times and check that the timer always increments and
20  *   never decrements during this loop.
21  *
22  * - Wait one second using rte_usleep() and check that the increment
23  *   of cycles is correct with regard to the frequency of the timer.
24  */
25 
26 static int
27 check_wait_one_second(void)
28 {
29 	uint64_t cycles, prev_cycles;
30 	uint64_t hz = rte_get_timer_hz();
31 	uint64_t max_inc = (hz / 100); /* 10 ms max between 2 reads */
32 
33 	/* check that waiting 1 second is precise */
34 	prev_cycles = rte_get_timer_cycles();
35 	rte_delay_us(1000000);
36 	cycles = rte_get_timer_cycles();
37 
38 	if ((uint64_t)(cycles - prev_cycles) > (hz + max_inc)) {
39 		printf("delay_us is not accurate: too long\n");
40 		return -1;
41 	}
42 	if ((uint64_t)(cycles - prev_cycles) < (hz - max_inc)) {
43 		printf("delay_us is not accurate: too short\n");
44 		return -1;
45 	}
46 
47 	return 0;
48 }
49 
50 static int
51 test_cycles(void)
52 {
53 	unsigned i;
54 	uint64_t start_cycles, cycles, prev_cycles;
55 	uint64_t hz = rte_get_timer_hz();
56 	uint64_t max_inc = (hz / 100); /* 10 ms max between 2 reads */
57 
58 	/* check that the timer is always incrementing */
59 	start_cycles = rte_get_timer_cycles();
60 	prev_cycles = start_cycles;
61 	for (i=0; i<N; i++) {
62 		cycles = rte_get_timer_cycles();
63 		if ((uint64_t)(cycles - prev_cycles) > max_inc) {
64 			printf("increment too high or going backwards\n");
65 			return -1;
66 		}
67 		prev_cycles = cycles;
68 	}
69 
70 	return check_wait_one_second();
71 }
72 
73 REGISTER_TEST_COMMAND(cycles_autotest, test_cycles);
74 
75 /*
76  * One second precision test with rte_delay_us_sleep.
77  */
78 
79 static int
80 test_delay_us_sleep(void)
81 {
82 	int rv;
83 
84 	rte_delay_us_callback_register(rte_delay_us_sleep);
85 	rv = check_wait_one_second();
86 	/* restore original delay function */
87 	rte_delay_us_callback_register(rte_delay_us_block);
88 
89 	return rv;
90 }
91 
92 REGISTER_TEST_COMMAND(delay_us_sleep_autotest, test_delay_us_sleep);
93 
94 /*
95  * rte_delay_us_callback test
96  *
97  * - check if callback is correctly registered/unregistered
98  *
99  */
100 
101 static unsigned int pattern;
102 static void my_rte_delay_us(unsigned int us)
103 {
104 	pattern += us;
105 }
106 
107 static int
108 test_user_delay_us(void)
109 {
110 	pattern = 0;
111 
112 	rte_delay_us(2);
113 	if (pattern != 0)
114 		return -1;
115 
116 	/* register custom delay function */
117 	rte_delay_us_callback_register(my_rte_delay_us);
118 
119 	rte_delay_us(2);
120 	if (pattern != 2)
121 		return -1;
122 
123 	rte_delay_us(3);
124 	if (pattern != 5)
125 		return -1;
126 
127 	/* restore original delay function */
128 	rte_delay_us_callback_register(rte_delay_us_block);
129 
130 	rte_delay_us(3);
131 	if (pattern != 5)
132 		return -1;
133 
134 	return 0;
135 }
136 
137 REGISTER_TEST_COMMAND(user_delay_us, test_user_delay_us);
138