ceph/src/dpdk/lib/librte_eal/linuxapp/eal/eal_timer.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *   Copyright(c) 2012-2013 6WIND S.A.
   6  *   All rights reserved.
   7  *
   8  *   Redistribution and use in source and binary forms, with or without
   9  *   modification, are permitted provided that the following conditions
  10  *   are met:
  11  *
  12  *     * Redistributions of source code must retain the above copyright
  13  *       notice, this list of conditions and the following disclaimer.
  14  *     * Redistributions in binary form must reproduce the above copyright
  15  *       notice, this list of conditions and the following disclaimer in
  16  *       the documentation and/or other materials provided with the
  17  *       distribution.
  18  *     * Neither the name of Intel Corporation nor the names of its
  19  *       contributors may be used to endorse or promote products derived
  20  *       from this software without specific prior written permission.
  21  *
  22  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  25  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  26  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  27  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  28  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  29  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  30  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  32  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #include <string.h>
  36 #include <stdlib.h>
  37 #include <stdio.h>
  38 #include <stdint.h>
  39 #include <unistd.h>
  40 #include <fcntl.h>
  41 #include <inttypes.h>
  42 #include <sys/mman.h>
  43 #include <sys/queue.h>
  44 #include <pthread.h>
  45 #include <errno.h>
  46
  47 #include <rte_common.h>
  48 #include <rte_log.h>
  49 #include <rte_cycles.h>
  50 #include <rte_lcore.h>
  51 #include <rte_memory.h>
  52 #include <rte_memzone.h>
  53 #include <rte_eal.h>
  54 #include <rte_debug.h>
  55
  56 #include "eal_private.h"
  57 #include "eal_internal_cfg.h"
  58
  59 enum timer_source eal_timer_source = EAL_TIMER_HPET;
  60
  61 #ifdef RTE_LIBEAL_USE_HPET
  62
  63 #define DEV_HPET "/dev/hpet"
  64
  65 /* Maximum number of counters. */
  66 #define HPET_TIMER_NUM 3
  67
  68 /* General capabilities register */
  69 #define CLK_PERIOD_SHIFT     32 /* Clock period shift. */
  70 #define CLK_PERIOD_MASK      0xffffffff00000000ULL /* Clock period mask. */
  71
  72 /**
  73  * HPET timer registers. From the Intel IA-PC HPET (High Precision Event
  74  * Timers) Specification.
  75  */
  76 struct eal_hpet_regs {
  77         /* Memory-mapped, software visible registers */
  78         uint64_t capabilities;      /**< RO General Capabilities Register. */
  79         uint64_t reserved0;         /**< Reserved for future use. */
  80         uint64_t config;            /**< RW General Configuration Register. */
  81         uint64_t reserved1;         /**< Reserved for future use. */
  82         uint64_t isr;               /**< RW Clear General Interrupt Status. */
  83         uint64_t reserved2[25];     /**< Reserved for future use. */
  84         union {
  85                 uint64_t counter;   /**< RW Main Counter Value Register. */
  86                 struct {
  87                         uint32_t counter_l; /**< RW Main Counter Low. */
  88                         uint32_t counter_h; /**< RW Main Counter High. */
  89                 };
  90         };
  91         uint64_t reserved3;         /**< Reserved for future use. */
  92         struct {
  93                 uint64_t config;    /**< RW Timer Config and Capability Reg. */
  94                 uint64_t comp;      /**< RW Timer Comparator Value Register. */
  95                 uint64_t fsb;       /**< RW FSB Interrupt Route Register. */
  96                 uint64_t reserved4; /**< Reserved for future use. */
  97         } timers[HPET_TIMER_NUM]; /**< Set of HPET timers. */
  98 };
  99
 100 /* Mmap'd hpet registers */
 101 static volatile struct eal_hpet_regs *eal_hpet = NULL;
 102
 103 /* Period at which the HPET counter increments in
 104  * femtoseconds (10^-15 seconds). */
 105 static uint32_t eal_hpet_resolution_fs = 0;
 106
 107 /* Frequency of the HPET counter in Hz */
 108 static uint64_t eal_hpet_resolution_hz = 0;
 109
 110 /* Incremented 4 times during one 32bits hpet full count */
 111 static uint32_t eal_hpet_msb;
 112
 113 static pthread_t msb_inc_thread_id;
 114
 115 /*
 116  * This function runs on a specific thread to update a global variable
 117  * containing used to process MSB of the HPET (unfortunatelly, we need
 118  * this because hpet is 32 bits by default under linux).
 119  */
 120 static void
 121 hpet_msb_inc(__attribute__((unused)) void *arg)
 122 {
 123         uint32_t t;
 124
 125         while (1) {
 126                 t = (eal_hpet->counter_l >> 30);
 127                 if (t != (eal_hpet_msb & 3))
 128                         eal_hpet_msb ++;
 129                 sleep(10);
 130         }
 131 }
 132
 133 uint64_t
 134 rte_get_hpet_hz(void)
 135 {
 136         if(internal_config.no_hpet)
 137                 rte_panic("Error, HPET called, but no HPET present\n");
 138
 139         return eal_hpet_resolution_hz;
 140 }
 141
 142 uint64_t
 143 rte_get_hpet_cycles(void)
 144 {
 145         uint32_t t, msb;
 146         uint64_t ret;
 147
 148         if(internal_config.no_hpet)
 149                 rte_panic("Error, HPET called, but no HPET present\n");
 150
 151         t = eal_hpet->counter_l;
 152         msb = eal_hpet_msb;
 153         ret = (msb + 2 - (t >> 30)) / 4;
 154         ret <<= 32;
 155         ret += t;
 156         return ret;
 157 }
 158
 159 #endif
 160
 161 #ifdef RTE_LIBEAL_USE_HPET
 162 /*
 163  * Open and mmap /dev/hpet (high precision event timer) that will
 164  * provide our time reference.
 165  */
 166 int
 167 rte_eal_hpet_init(int make_default)
 168 {
 169         int fd, ret;
 170         char thread_name[RTE_MAX_THREAD_NAME_LEN];
 171
 172         if (internal_config.no_hpet) {
 173                 RTE_LOG(NOTICE, EAL, "HPET is disabled\n");
 174                 return -1;
 175         }
 176
 177         fd = open(DEV_HPET, O_RDONLY);
 178         if (fd < 0) {
 179                 RTE_LOG(ERR, EAL, "ERROR: Cannot open "DEV_HPET": %s!\n",
 180                         strerror(errno));
 181                 internal_config.no_hpet = 1;
 182                 return -1;
 183         }
 184         eal_hpet = mmap(NULL, 1024, PROT_READ, MAP_SHARED, fd, 0);
 185         if (eal_hpet == MAP_FAILED) {
 186                 RTE_LOG(ERR, EAL, "ERROR: Cannot mmap "DEV_HPET"!\n"
 187                                 "Please enable CONFIG_HPET_MMAP in your kernel configuration "
 188                                 "to allow HPET support.\n"
 189                                 "To run without using HPET, set CONFIG_RTE_LIBEAL_USE_HPET=n "
 190                                 "in your build configuration or use '--no-hpet' EAL flag.\n");
 191                 close(fd);
 192                 internal_config.no_hpet = 1;
 193                 return -1;
 194         }
 195         close(fd);
 196
 197         eal_hpet_resolution_fs = (uint32_t)((eal_hpet->capabilities &
 198                                         CLK_PERIOD_MASK) >>
 199                                         CLK_PERIOD_SHIFT);
 200
 201         eal_hpet_resolution_hz = (1000ULL*1000ULL*1000ULL*1000ULL*1000ULL) /
 202                 (uint64_t)eal_hpet_resolution_fs;
 203
 204         RTE_LOG(INFO, EAL, "HPET frequency is ~%"PRIu64" kHz\n",
 205                         eal_hpet_resolution_hz/1000);
 206
 207         eal_hpet_msb = (eal_hpet->counter_l >> 30);
 208
 209         /* create a thread that will increment a global variable for
 210          * msb (hpet is 32 bits by default under linux) */
 211         ret = pthread_create(&msb_inc_thread_id, NULL,
 212                         (void *(*)(void *))hpet_msb_inc, NULL);
 213         if (ret != 0) {
 214                 RTE_LOG(ERR, EAL, "ERROR: Cannot create HPET timer thread!\n");
 215                 internal_config.no_hpet = 1;
 216                 return -1;
 217         }
 218
 219         /*
 220          * Set thread_name for aid in debugging.
 221          */
 222         snprintf(thread_name, RTE_MAX_THREAD_NAME_LEN, "hpet-msb-inc");
 223         ret = rte_thread_setname(msb_inc_thread_id, thread_name);
 224         if (ret != 0)
 225                 RTE_LOG(DEBUG, EAL,
 226                         "Cannot set HPET timer thread name!\n");
 227
 228         if (make_default)
 229                 eal_timer_source = EAL_TIMER_HPET;
 230         return 0;
 231 }
 232 #endif
 233
 234 static void
 235 check_tsc_flags(void)
 236 {
 237         char line[512];
 238         FILE *stream;
 239
 240         stream = fopen("/proc/cpuinfo", "r");
 241         if (!stream) {
 242                 RTE_LOG(WARNING, EAL, "WARNING: Unable to open /proc/cpuinfo\n");
 243                 return;
 244         }
 245
 246         while (fgets(line, sizeof line, stream)) {
 247                 char *constant_tsc;
 248                 char *nonstop_tsc;
 249
 250                 if (strncmp(line, "flags", 5) != 0)
 251                         continue;
 252
 253                 constant_tsc = strstr(line, "constant_tsc");
 254                 nonstop_tsc = strstr(line, "nonstop_tsc");
 255                 if (!constant_tsc || !nonstop_tsc)
 256                         RTE_LOG(WARNING, EAL,
 257                                 "WARNING: cpu flags "
 258                                 "constant_tsc=%s "
 259                                 "nonstop_tsc=%s "
 260                                 "-> using unreliable clock cycles !\n",
 261                                 constant_tsc ? "yes":"no",
 262                                 nonstop_tsc ? "yes":"no");
 263                 break;
 264         }
 265
 266         fclose(stream);
 267 }
 268
 269 uint64_t
 270 get_tsc_freq(void)
 271 {
 272 #ifdef CLOCK_MONOTONIC_RAW
 273 #define NS_PER_SEC 1E9
 274
 275         struct timespec sleeptime = {.tv_nsec = NS_PER_SEC / 10 }; /* 1/10 second */
 276
 277         struct timespec t_start, t_end;
 278         uint64_t tsc_hz;
 279
 280         if (clock_gettime(CLOCK_MONOTONIC_RAW, &t_start) == 0) {
 281                 uint64_t ns, end, start = rte_rdtsc();
 282                 nanosleep(&sleeptime,NULL);
 283                 clock_gettime(CLOCK_MONOTONIC_RAW, &t_end);
 284                 end = rte_rdtsc();
 285                 ns = ((t_end.tv_sec - t_start.tv_sec) * NS_PER_SEC);
 286                 ns += (t_end.tv_nsec - t_start.tv_nsec);
 287
 288                 double secs = (double)ns/NS_PER_SEC;
 289                 tsc_hz = (uint64_t)((end - start)/secs);
 290                 return tsc_hz;
 291         }
 292 #endif
 293         return 0;
 294 }
 295
 296 int
 297 rte_eal_timer_init(void)
 298 {
 299
 300         eal_timer_source = EAL_TIMER_TSC;
 301
 302         set_tsc_freq();
 303         check_tsc_flags();
 304         return 0;
 305 }