app/test/test_cycles.c

   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);