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 #include <rte_eal.h>
  19
  20 #include "eal_private.h"
  21 #include "eal_memcfg.h"
  22
  23 /* The frequency of the RDTSC timer resolution */
  24 static uint64_t eal_tsc_resolution_hz;
  25
  26 /* Pointer to user delay function */
  27 void (*rte_delay_us)(unsigned int) = NULL;
  28
  29 void
  30 rte_delay_us_block(unsigned int us)
  31 {
  32         const uint64_t start = rte_get_timer_cycles();
  33         const uint64_t ticks = (uint64_t)us * rte_get_timer_hz() / 1E6;
  34         while ((rte_get_timer_cycles() - start) < ticks)
  35                 rte_pause();
  36 }
  37
  38 void
  39 rte_delay_us_sleep(unsigned int us)
  40 {
  41         struct timespec wait[2];
  42         int ind = 0;
  43
  44         wait[0].tv_sec = 0;
  45         if (us >= US_PER_S) {
  46                 wait[0].tv_sec = us / US_PER_S;
  47                 us -= wait[0].tv_sec * US_PER_S;
  48         }
  49         wait[0].tv_nsec = 1000 * us;
  50
  51         while (nanosleep(&wait[ind], &wait[1 - ind]) && errno == EINTR) {
  52                 /*
  53                  * Sleep was interrupted. Flip the index, so the 'remainder'
  54                  * will become the 'request' for a next call.
  55                  */
  56                 ind = 1 - ind;
  57         }
  58 }
  59
  60 uint64_t
  61 rte_get_tsc_hz(void)
  62 {
  63         return eal_tsc_resolution_hz;
  64 }
  65
  66 static uint64_t
  67 estimate_tsc_freq(void)
  68 {
  69 #define CYC_PER_10MHZ 1E7
  70         RTE_LOG(WARNING, EAL, "WARNING: TSC frequency estimated roughly"
  71                 " - clock timings may be less accurate.\n");
  72         /* assume that the sleep(1) will sleep for 1 second */
  73         uint64_t start = rte_rdtsc();
  74         sleep(1);
  75         /* Round up to 10Mhz. 1E7 ~ 10Mhz */
  76         return RTE_ALIGN_MUL_NEAR(rte_rdtsc() - start, CYC_PER_10MHZ);
  77 }
  78
  79 void
  80 set_tsc_freq(void)
  81 {
  82         struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
  83         uint64_t freq;
  84
  85         if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
  86                 /*
  87                  * Just use the primary process calculated TSC rate in any
  88                  * secondary process.  It avoids any unnecessary overhead on
  89                  * systems where arch-specific frequency detection is not
  90                  * available.
  91                  */
  92                 eal_tsc_resolution_hz = mcfg->tsc_hz;
  93                 return;
  94         }
  95
  96         freq = get_tsc_freq_arch();
  97         if (!freq)
  98                 freq = get_tsc_freq();
  99         if (!freq)
 100                 freq = estimate_tsc_freq();
 101
 102         RTE_LOG(DEBUG, EAL, "TSC frequency is ~%" PRIu64 " KHz\n", freq / 1000);
 103         eal_tsc_resolution_hz = freq;
 104         mcfg->tsc_hz = freq;
 105 }
 106
 107 void rte_delay_us_callback_register(void (*userfunc)(unsigned int))
 108 {
 109         rte_delay_us = userfunc;
 110 }
 111
 112 RTE_INIT(rte_timer_init)
 113 {
 114         /* set rte_delay_us_block as a delay function */
 115         rte_delay_us_callback_register(rte_delay_us_block);
 116 }