xref: /dpdk/lib/eal/common/eal_common_timer.c (revision dbdf3d5581caa1de40b5952e41d54b64e39536d1)
199a2dd95SBruce Richardson /* SPDX-License-Identifier: BSD-3-Clause
299a2dd95SBruce Richardson  * Copyright(c) 2010-2014 Intel Corporation
399a2dd95SBruce Richardson  */
499a2dd95SBruce Richardson 
599a2dd95SBruce Richardson #include <stdio.h>
699a2dd95SBruce Richardson #include <inttypes.h>
799a2dd95SBruce Richardson 
899a2dd95SBruce Richardson #include <rte_common.h>
999a2dd95SBruce Richardson #include <rte_log.h>
1099a2dd95SBruce Richardson #include <rte_cycles.h>
1199a2dd95SBruce Richardson #include <rte_pause.h>
1299a2dd95SBruce Richardson #include <rte_eal.h>
1399a2dd95SBruce Richardson 
1499a2dd95SBruce Richardson #include "eal_private.h"
1599a2dd95SBruce Richardson #include "eal_memcfg.h"
1699a2dd95SBruce Richardson 
1799a2dd95SBruce Richardson /* The frequency of the RDTSC timer resolution */
1899a2dd95SBruce Richardson static uint64_t eal_tsc_resolution_hz;
1999a2dd95SBruce Richardson 
2099a2dd95SBruce Richardson /* Pointer to user delay function */
2199a2dd95SBruce Richardson void (*rte_delay_us)(unsigned int) = NULL;
2299a2dd95SBruce Richardson 
2399a2dd95SBruce Richardson void
2499a2dd95SBruce Richardson rte_delay_us_block(unsigned int us)
2599a2dd95SBruce Richardson {
2699a2dd95SBruce Richardson 	const uint64_t start = rte_get_timer_cycles();
2799a2dd95SBruce Richardson 	const uint64_t ticks = (uint64_t)us * rte_get_timer_hz() / 1E6;
2899a2dd95SBruce Richardson 	while ((rte_get_timer_cycles() - start) < ticks)
2999a2dd95SBruce Richardson 		rte_pause();
3099a2dd95SBruce Richardson }
3199a2dd95SBruce Richardson 
3299a2dd95SBruce Richardson uint64_t
3399a2dd95SBruce Richardson rte_get_tsc_hz(void)
3499a2dd95SBruce Richardson {
3599a2dd95SBruce Richardson 	return eal_tsc_resolution_hz;
3699a2dd95SBruce Richardson }
3799a2dd95SBruce Richardson 
3899a2dd95SBruce Richardson static uint64_t
3999a2dd95SBruce Richardson estimate_tsc_freq(void)
4099a2dd95SBruce Richardson {
4199a2dd95SBruce Richardson #define CYC_PER_10MHZ 1E7
42ae67895bSDavid Marchand 	EAL_LOG(WARNING, "WARNING: TSC frequency estimated roughly"
43ae67895bSDavid Marchand 		" - clock timings may be less accurate.");
4499a2dd95SBruce Richardson 	/* assume that the rte_delay_us_sleep() will sleep for 1 second */
4599a2dd95SBruce Richardson 	uint64_t start = rte_rdtsc();
4699a2dd95SBruce Richardson 	rte_delay_us_sleep(US_PER_S);
4799a2dd95SBruce Richardson 	/* Round up to 10Mhz. 1E7 ~ 10Mhz */
4899a2dd95SBruce Richardson 	return RTE_ALIGN_MUL_NEAR(rte_rdtsc() - start, CYC_PER_10MHZ);
4999a2dd95SBruce Richardson }
5099a2dd95SBruce Richardson 
5199a2dd95SBruce Richardson void
5299a2dd95SBruce Richardson set_tsc_freq(void)
5399a2dd95SBruce Richardson {
5499a2dd95SBruce Richardson 	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
5599a2dd95SBruce Richardson 	uint64_t freq;
5699a2dd95SBruce Richardson 
5799a2dd95SBruce Richardson 	if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
5899a2dd95SBruce Richardson 		/*
5999a2dd95SBruce Richardson 		 * Just use the primary process calculated TSC rate in any
6099a2dd95SBruce Richardson 		 * secondary process.  It avoids any unnecessary overhead on
6199a2dd95SBruce Richardson 		 * systems where arch-specific frequency detection is not
6299a2dd95SBruce Richardson 		 * available.
6399a2dd95SBruce Richardson 		 */
6499a2dd95SBruce Richardson 		eal_tsc_resolution_hz = mcfg->tsc_hz;
6599a2dd95SBruce Richardson 		return;
6699a2dd95SBruce Richardson 	}
6799a2dd95SBruce Richardson 
6899a2dd95SBruce Richardson 	freq = get_tsc_freq_arch();
69*dbdf3d55SIsaac Boukris 	freq = get_tsc_freq(freq);
7099a2dd95SBruce Richardson 	if (!freq)
7199a2dd95SBruce Richardson 		freq = estimate_tsc_freq();
7299a2dd95SBruce Richardson 
73ae67895bSDavid Marchand 	EAL_LOG(DEBUG, "TSC frequency is ~%" PRIu64 " KHz", freq / 1000);
7499a2dd95SBruce Richardson 	eal_tsc_resolution_hz = freq;
7599a2dd95SBruce Richardson 	mcfg->tsc_hz = freq;
7699a2dd95SBruce Richardson }
7799a2dd95SBruce Richardson 
7899a2dd95SBruce Richardson void rte_delay_us_callback_register(void (*userfunc)(unsigned int))
7999a2dd95SBruce Richardson {
8099a2dd95SBruce Richardson 	rte_delay_us = userfunc;
8199a2dd95SBruce Richardson }
8299a2dd95SBruce Richardson 
8399a2dd95SBruce Richardson RTE_INIT(rte_timer_init)
8499a2dd95SBruce Richardson {
8599a2dd95SBruce Richardson 	/* set rte_delay_us_block as a delay function */
8699a2dd95SBruce Richardson 	rte_delay_us_callback_register(rte_delay_us_block);
8799a2dd95SBruce Richardson }
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