lib/librte_eal/windows/eal_timer.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright 2020 Mellanox Technologies, Ltd
   3  */
   4
   5 #include <inttypes.h>
   6
   7 #include <rte_windows.h>
   8 #include <rte_common.h>
   9 #include <rte_cycles.h>
  10 #include <rte_eal.h>
  11 #include <rte_errno.h>
  12 #include "eal_private.h"
  13
  14 #define US_PER_SEC 1E6
  15 #define CYC_PER_10MHZ 1E7
  16
  17 void
  18 rte_delay_us_sleep(unsigned int us)
  19 {
  20         HANDLE timer;
  21         LARGE_INTEGER due_time;
  22
  23         /* create waitable timer */
  24         timer = CreateWaitableTimer(NULL, TRUE, NULL);
  25         if (!timer) {
  26                 RTE_LOG_WIN32_ERR("CreateWaitableTimer()");
  27                 rte_errno = ENOMEM;
  28                 return;
  29         }
  30
  31         /*
  32          * due_time's uom is 100 ns, multiply by 10 to convert to microseconds
  33          * set us microseconds time for timer
  34          */
  35         due_time.QuadPart = -((int64_t)us * 10);
  36         if (!SetWaitableTimer(timer, &due_time, 0, NULL, NULL, FALSE)) {
  37                 RTE_LOG_WIN32_ERR("SetWaitableTimer()");
  38                 rte_errno = EINVAL;
  39                 goto end;
  40         }
  41         /* start wait for timer for us microseconds */
  42         if (WaitForSingleObject(timer, INFINITE) == WAIT_FAILED) {
  43                 RTE_LOG_WIN32_ERR("WaitForSingleObject()");
  44                 rte_errno = EINVAL;
  45         }
  46
  47 end:
  48         CloseHandle(timer);
  49 }
  50
  51 uint64_t
  52 get_tsc_freq(void)
  53 {
  54         LARGE_INTEGER t_start, t_end, elapsed_us;
  55         LARGE_INTEGER frequency;
  56         uint64_t tsc_hz;
  57         uint64_t end, start;
  58
  59         QueryPerformanceFrequency(&frequency);
  60
  61         QueryPerformanceCounter(&t_start);
  62         start = rte_get_tsc_cycles();
  63
  64         rte_delay_us_sleep(US_PER_SEC / 10); /* 1/10 second */
  65
  66         if (rte_errno != 0)
  67                 return 0;
  68
  69         QueryPerformanceCounter(&t_end);
  70         end = rte_get_tsc_cycles();
  71
  72         elapsed_us.QuadPart = t_end.QuadPart - t_start.QuadPart;
  73
  74         /*
  75          * To guard against loss-of-precision, convert to microseconds
  76          * *before* dividing by ticks-per-second.
  77          */
  78         elapsed_us.QuadPart *= US_PER_SEC;
  79         elapsed_us.QuadPart /= frequency.QuadPart;
  80
  81         double secs = ((double)elapsed_us.QuadPart)/US_PER_SEC;
  82         tsc_hz = (uint64_t)((end - start)/secs);
  83
  84         /* Round up to 10Mhz. 1E7 ~ 10Mhz */
  85         return RTE_ALIGN_MUL_NEAR(tsc_hz, CYC_PER_10MHZ);
  86 }
  87
  88
  89 int
  90 rte_eal_timer_init(void)
  91 {
  92         set_tsc_freq();
  93         return 0;
  94 }