lib/librte_eal/common/eal_common_timer.c

   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 #define CYC_PER_10MHZ 1E7
  68         RTE_LOG(WARNING, EAL, "WARNING: TSC frequency estimated roughly"
  69                 " - clock timings may be less accurate.\n");
  70         /* assume that the sleep(1) will sleep for 1 second */
  71         uint64_t start = rte_rdtsc();
  72         sleep(1);
  73         /* Round up to 10Mhz. 1E7 ~ 10Mhz */
  74         return RTE_ALIGN_MUL_NEAR(rte_rdtsc() - start, CYC_PER_10MHZ);
  75 }
  76
  77 void
  78 set_tsc_freq(void)
  79 {
  80         uint64_t freq;
  81
  82         freq = get_tsc_freq_arch();
  83         if (!freq)
  84                 freq = get_tsc_freq();
  85         if (!freq)
  86                 freq = estimate_tsc_freq();
  87
  88         RTE_LOG(DEBUG, EAL, "TSC frequency is ~%" PRIu64 " KHz\n", freq / 1000);
  89         eal_tsc_resolution_hz = freq;
  90 }
  91
  92 void rte_delay_us_callback_register(void (*userfunc)(unsigned int))
  93 {
  94         rte_delay_us = userfunc;
  95 }
  96
  97 RTE_INIT(rte_timer_init)
  98 {
  99         /* set rte_delay_us_block as a delay function */
 100         rte_delay_us_callback_register(rte_delay_us_block);
 101 }