diff options
Diffstat (limited to 'src/dpdk_lib18/librte_eal/linuxapp/eal/eal_timer.c')
| -rwxr-xr-x | src/dpdk_lib18/librte_eal/linuxapp/eal/eal_timer.c | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/src/dpdk_lib18/librte_eal/linuxapp/eal/eal_timer.c b/src/dpdk_lib18/librte_eal/linuxapp/eal/eal_timer.c new file mode 100755 index 00000000..6321e42e --- /dev/null +++ b/src/dpdk_lib18/librte_eal/linuxapp/eal/eal_timer.c @@ -0,0 +1,344 @@ +/*- + * BSD LICENSE + * + * Copyright(c) 2010-2014 Intel Corporation. All rights reserved. + * Copyright(c) 2012-2013 6WIND S.A. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <string.h> +#include <stdlib.h> +#include <stdio.h> +#include <stdint.h> +#include <unistd.h> +#include <fcntl.h> +#include <inttypes.h> +#include <sys/mman.h> +#include <sys/queue.h> +#include <pthread.h> +#include <errno.h> + +#include <rte_common.h> +#include <rte_log.h> +#include <rte_cycles.h> +#include <rte_tailq.h> +#include <rte_memory.h> +#include <rte_memzone.h> +#include <rte_eal.h> +#include <rte_debug.h> + +#include "eal_private.h" +#include "eal_internal_cfg.h" + +enum timer_source eal_timer_source = EAL_TIMER_HPET; + +/* The frequency of the RDTSC timer resolution */ +static uint64_t eal_tsc_resolution_hz = 0; + +#ifdef RTE_LIBEAL_USE_HPET + +#define DEV_HPET "/dev/hpet" + +/* Maximum number of counters. */ +#define HPET_TIMER_NUM 3 + +/* General capabilities register */ +#define CLK_PERIOD_SHIFT 32 /* Clock period shift. */ +#define CLK_PERIOD_MASK 0xffffffff00000000ULL /* Clock period mask. */ + +/** + * HPET timer registers. From the Intel IA-PC HPET (High Precision Event + * Timers) Specification. + */ +struct eal_hpet_regs { + /* Memory-mapped, software visible registers */ + uint64_t capabilities; /**< RO General Capabilities Register. */ + uint64_t reserved0; /**< Reserved for future use. */ + uint64_t config; /**< RW General Configuration Register. */ + uint64_t reserved1; /**< Reserved for future use. */ + uint64_t isr; /**< RW Clear General Interrupt Status. */ + uint64_t reserved2[25]; /**< Reserved for future use. */ + union { + uint64_t counter; /**< RW Main Counter Value Register. */ + struct { + uint32_t counter_l; /**< RW Main Counter Low. */ + uint32_t counter_h; /**< RW Main Counter High. */ + }; + }; + uint64_t reserved3; /**< Reserved for future use. */ + struct { + uint64_t config; /**< RW Timer Config and Capability Reg. */ + uint64_t comp; /**< RW Timer Comparator Value Register. */ + uint64_t fsb; /**< RW FSB Interrupt Route Register. */ + uint64_t reserved4; /**< Reserved for future use. */ + } timers[HPET_TIMER_NUM]; /**< Set of HPET timers. */ +}; + +/* Mmap'd hpet registers */ +static volatile struct eal_hpet_regs *eal_hpet = NULL; + +/* Period at which the HPET counter increments in + * femtoseconds (10^-15 seconds). */ +static uint32_t eal_hpet_resolution_fs = 0; + +/* Frequency of the HPET counter in Hz */ +static uint64_t eal_hpet_resolution_hz = 0; + +/* Incremented 4 times during one 32bits hpet full count */ +static uint32_t eal_hpet_msb; + +static pthread_t msb_inc_thread_id; + +/* + * This function runs on a specific thread to update a global variable + * containing used to process MSB of the HPET (unfortunatelly, we need + * this because hpet is 32 bits by default under linux). + */ +static void +hpet_msb_inc(__attribute__((unused)) void *arg) +{ + uint32_t t; + + while (1) { + t = (eal_hpet->counter_l >> 30); + if (t != (eal_hpet_msb & 3)) + eal_hpet_msb ++; + sleep(10); + } +} + +uint64_t +rte_get_hpet_hz(void) +{ + if(internal_config.no_hpet) + rte_panic("Error, HPET called, but no HPET present\n"); + + return eal_hpet_resolution_hz; +} + +uint64_t +rte_get_hpet_cycles(void) +{ + uint32_t t, msb; + uint64_t ret; + + if(internal_config.no_hpet) + rte_panic("Error, HPET called, but no HPET present\n"); + + t = eal_hpet->counter_l; + msb = eal_hpet_msb; + ret = (msb + 2 - (t >> 30)) / 4; + ret <<= 32; + ret += t; + return ret; +} + +#endif + + +void +rte_delay_us(unsigned us) +{ + const uint64_t start = rte_get_timer_cycles(); + const uint64_t ticks = (uint64_t)us * rte_get_timer_hz() / 1E6; + while ((rte_get_timer_cycles() - start) < ticks) + rte_pause(); +} + +uint64_t +rte_get_tsc_hz(void) +{ + return eal_tsc_resolution_hz; +} + + +#ifdef RTE_LIBEAL_USE_HPET +/* + * Open and mmap /dev/hpet (high precision event timer) that will + * provide our time reference. + */ +int +rte_eal_hpet_init(int make_default) +{ + int fd, ret; + + if (internal_config.no_hpet) { + RTE_LOG(INFO, EAL, "HPET is disabled\n"); + return -1; + } + + fd = open(DEV_HPET, O_RDONLY); + if (fd < 0) { + RTE_LOG(ERR, EAL, "ERROR: Cannot open "DEV_HPET": %s!\n", + strerror(errno)); + internal_config.no_hpet = 1; + return -1; + } + eal_hpet = mmap(NULL, 1024, PROT_READ, MAP_SHARED, fd, 0); + if (eal_hpet == MAP_FAILED) { + RTE_LOG(ERR, EAL, "ERROR: Cannot mmap "DEV_HPET"!\n" + "Please enable CONFIG_HPET_MMAP in your kernel configuration " + "to allow HPET support.\n" + "To run without using HPET, set CONFIG_RTE_LIBEAL_USE_HPET=n " + "in your build configuration or use '--no-hpet' EAL flag.\n"); + close(fd); + internal_config.no_hpet = 1; + return -1; + } + close(fd); + + eal_hpet_resolution_fs = (uint32_t)((eal_hpet->capabilities & + CLK_PERIOD_MASK) >> + CLK_PERIOD_SHIFT); + + eal_hpet_resolution_hz = (1000ULL*1000ULL*1000ULL*1000ULL*1000ULL) / + (uint64_t)eal_hpet_resolution_fs; + + RTE_LOG(INFO, EAL, "HPET frequency is ~%"PRIu64" kHz\n", + eal_hpet_resolution_hz/1000); + + eal_hpet_msb = (eal_hpet->counter_l >> 30); + + /* create a thread that will increment a global variable for + * msb (hpet is 32 bits by default under linux) */ + ret = pthread_create(&msb_inc_thread_id, NULL, + (void *(*)(void *))hpet_msb_inc, NULL); + if (ret < 0) { + RTE_LOG(ERR, EAL, "ERROR: Cannot create HPET timer thread!\n"); + internal_config.no_hpet = 1; + return -1; + } + + if (make_default) + eal_timer_source = EAL_TIMER_HPET; + return 0; +} +#endif + +static void +check_tsc_flags(void) +{ + char line[512]; + FILE *stream; + + stream = fopen("/proc/cpuinfo", "r"); + if (!stream) { + RTE_LOG(WARNING, EAL, "WARNING: Unable to open /proc/cpuinfo\n"); + return; + } + + while (fgets(line, sizeof line, stream)) { + char *constant_tsc; + char *nonstop_tsc; + + if (strncmp(line, "flags", 5) != 0) + continue; + + constant_tsc = strstr(line, "constant_tsc"); + nonstop_tsc = strstr(line, "nonstop_tsc"); + if (!constant_tsc || !nonstop_tsc) + RTE_LOG(WARNING, EAL, + "WARNING: cpu flags " + "constant_tsc=%s " + "nonstop_tsc=%s " + "-> using unreliable clock cycles !\n", + constant_tsc ? "yes":"no", + nonstop_tsc ? "yes":"no"); + break; + } + + fclose(stream); +} + +static int +set_tsc_freq_from_clock(void) +{ +#if 0 +//CLOCK_MONOTONIC_RAW +#define NS_PER_SEC 1E9 + + struct timespec sleeptime = {.tv_nsec = 5E8 }; /* 1/2 second */ + + struct timespec t_start, t_end; + + if (clock_gettime(CLOCK_MONOTONIC_RAW, &t_start) == 0) { + uint64_t ns, end, start = rte_rdtsc(); + nanosleep(&sleeptime,NULL); + clock_gettime(CLOCK_MONOTONIC_RAW, &t_end); + end = rte_rdtsc(); + ns = ((t_end.tv_sec - t_start.tv_sec) * NS_PER_SEC); + ns += (t_end.tv_nsec - t_start.tv_nsec); + + double secs = (double)ns/NS_PER_SEC; + eal_tsc_resolution_hz = (uint64_t)((end - start)/secs); + return 0; + } +#endif + return -1; +} + +static void +set_tsc_freq_fallback(void) +{ + RTE_LOG(WARNING, EAL, "WARNING: clock_gettime cannot use " + "CLOCK_MONOTONIC_RAW and HPET is not available" + " - clock timings may be less accurate.\n"); + /* assume that the sleep(1) will sleep for 1 second */ + uint64_t start = rte_rdtsc(); + sleep(1); + eal_tsc_resolution_hz = rte_rdtsc() - start; +} +/* + * This function measures the TSC frequency. It uses a variety of approaches. + * + * 1. If kernel provides CLOCK_MONOTONIC_RAW we use that to tune the TSC value + * 2. If kernel does not provide that, and we have HPET support, tune using HPET + * 3. Lastly, if neither of the above can be used, just sleep for 1 second and + * tune off that, printing a warning about inaccuracy of timing + */ +static void +set_tsc_freq(void) +{ + if (set_tsc_freq_from_clock() < 0) + set_tsc_freq_fallback(); + + RTE_LOG(INFO, EAL, "TSC frequency is ~%"PRIu64" KHz\n", + eal_tsc_resolution_hz/1000); +} + +int +rte_eal_timer_init(void) +{ + + eal_timer_source = EAL_TIMER_TSC; + + set_tsc_freq(); + check_tsc_flags(); + return 0; +} |