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Diffstat (limited to 'lib/librte_eal/common/include/arch/arm/rte_cycles_32.h')
-rw-r--r-- | lib/librte_eal/common/include/arch/arm/rte_cycles_32.h | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/lib/librte_eal/common/include/arch/arm/rte_cycles_32.h b/lib/librte_eal/common/include/arch/arm/rte_cycles_32.h new file mode 100644 index 00000000..9c1be71e --- /dev/null +++ b/lib/librte_eal/common/include/arch/arm/rte_cycles_32.h @@ -0,0 +1,121 @@ +/* + * BSD LICENSE + * + * Copyright(c) 2015 RehiveTech. 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 RehiveTech 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. + */ + +#ifndef _RTE_CYCLES_ARM32_H_ +#define _RTE_CYCLES_ARM32_H_ + +/* ARM v7 does not have suitable source of clock signals. The only clock counter + available in the core is 32 bit wide. Therefore it is unsuitable as the + counter overlaps every few seconds and probably is not accessible by + userspace programs. Therefore we use clock_gettime(CLOCK_MONOTONIC_RAW) to + simulate counter running at 1GHz. +*/ + +#include <time.h> + +#ifdef __cplusplus +extern "C" { +#endif + +#include "generic/rte_cycles.h" + +/** + * Read the time base register. + * + * @return + * The time base for this lcore. + */ +#ifndef RTE_ARM_EAL_RDTSC_USE_PMU + +/** + * This call is easily portable to any ARM architecture, however, + * it may be damn slow and inprecise for some tasks. + */ +static inline uint64_t +__rte_rdtsc_syscall(void) +{ + struct timespec val; + uint64_t v; + + while (clock_gettime(CLOCK_MONOTONIC_RAW, &val) != 0) + /* no body */; + + v = (uint64_t) val.tv_sec * 1000000000LL; + v += (uint64_t) val.tv_nsec; + return v; +} +#define rte_rdtsc __rte_rdtsc_syscall + +#else + +/** + * This function requires to configure the PMCCNTR and enable + * userspace access to it: + * + * asm volatile("mcr p15, 0, %0, c9, c14, 0" : : "r"(1)); + * asm volatile("mcr p15, 0, %0, c9, c12, 0" : : "r"(29)); + * asm volatile("mcr p15, 0, %0, c9, c12, 1" : : "r"(0x8000000f)); + * + * which is possible only from the priviledged mode (kernel space). + */ +static inline uint64_t +__rte_rdtsc_pmccntr(void) +{ + unsigned tsc; + uint64_t final_tsc; + + /* Read PMCCNTR */ + asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r"(tsc)); + /* 1 tick = 64 clocks */ + final_tsc = ((uint64_t)tsc) << 6; + + return (uint64_t)final_tsc; +} +#define rte_rdtsc __rte_rdtsc_pmccntr + +#endif /* RTE_ARM_EAL_RDTSC_USE_PMU */ + +static inline uint64_t +rte_rdtsc_precise(void) +{ + rte_mb(); + return rte_rdtsc(); +} + +static inline uint64_t +rte_get_tsc_cycles(void) { return rte_rdtsc(); } + +#ifdef __cplusplus +} +#endif + +#endif /* _RTE_CYCLES_ARM32_H_ */ |