test/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 test_cycles(void)
  28 {
  29         unsigned i;
  30         uint64_t start_cycles, cycles, prev_cycles;
  31         uint64_t hz = rte_get_timer_hz();
  32         uint64_t max_inc = (hz / 100); /* 10 ms max between 2 reads */
  33
  34         /* check that the timer is always incrementing */
  35         start_cycles = rte_get_timer_cycles();
  36         prev_cycles = start_cycles;
  37         for (i=0; i<N; i++) {
  38                 cycles = rte_get_timer_cycles();
  39                 if ((uint64_t)(cycles - prev_cycles) > max_inc) {
  40                         printf("increment too high or going backwards\n");
  41                         return -1;
  42                 }
  43                 prev_cycles = cycles;
  44         }
  45
  46         /* check that waiting 1 second is precise */
  47         prev_cycles = rte_get_timer_cycles();
  48         rte_delay_us(1000000);
  49         cycles = rte_get_timer_cycles();
  50
  51         if ((uint64_t)(cycles - prev_cycles) > (hz + max_inc)) {
  52                 printf("delay_us is not accurate: too long\n");
  53                 return -1;
  54         }
  55         if ((uint64_t)(cycles - prev_cycles) < (hz - max_inc)) {
  56                 printf("delay_us is not accurate: too short\n");
  57                 return -1;
  58         }
  59
  60         return 0;
  61 }
  62
  63 REGISTER_TEST_COMMAND(cycles_autotest, test_cycles);
  64
  65 /*
  66  * rte_delay_us_callback test
  67  *
  68  * - check if callback is correctly registered/unregistered
  69  *
  70  */
  71
  72 static unsigned int pattern;
  73 static void my_rte_delay_us(unsigned int us)
  74 {
  75         pattern += us;
  76 }
  77
  78 static int
  79 test_user_delay_us(void)
  80 {
  81         pattern = 0;
  82
  83         rte_delay_us(2);
  84         if (pattern != 0)
  85                 return -1;
  86
  87         /* register custom delay function */
  88         rte_delay_us_callback_register(my_rte_delay_us);
  89
  90         rte_delay_us(2);
  91         if (pattern != 2)
  92                 return -1;
  93
  94         rte_delay_us(3);
  95         if (pattern != 5)
  96                 return -1;
  97
  98         /* restore original delay function */
  99         rte_delay_us_callback_register(rte_delay_us_block);
 100
 101         rte_delay_us(3);
 102         if (pattern != 5)
 103                 return -1;
 104
 105         return 0;
 106 }
 107
 108 REGISTER_TEST_COMMAND(user_delay_us, test_user_delay_us);