> diff --git a/lib/librte_eal/x86/include/rte_power_intrinsics.h
> b/lib/librte_eal/x86/include/rte_power_intrinsics.h
> new file mode 100644
> index 0000000000..6dd1cdc939
> --- /dev/null
> +++ b/lib/librte_eal/x86/include/rte_power_intrinsics.h
> @@ -0,0 +1,143 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2020 Intel Corporation
> + */
> +
> +#ifndef _RTE_POWER_INTRINSIC_X86_64_H_
> +#define _RTE_POWER_INTRINSIC_X86_64_H_
As a nit - if the function below are supported for both 64 and 32 ISA,
then probably: RTE_POWER_INTRINSIC_X86_H_
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +#include <rte_atomic.h>
> +#include <rte_common.h>
> +
> +#include "generic/rte_power_intrinsics.h"
> +
> +/**
> + * Monitor specific address for changes. This will cause the CPU to enter an
> + * architecture-defined optimized power state until either the specified
> + * memory address is written to, or a certain TSC timestamp is reached.
> + *
> + * Additionally, an `expected` 64-bit value and 64-bit mask are provided. If
> + * mask is non-zero, the current value pointed to by the `p` pointer will be
> + * checked against the expected value, and if they match, the entering of
> + * optimized power state may be aborted.
> + *
> + * This function uses UMONITOR/UMWAIT instructions. For more information
> about
> + * their usage, please refer to Intel(R) 64 and IA-32 Architectures Software
> + * Developer's Manual.
> + *
> + * @param p
> + * Address to monitor for changes. Must be aligned on an 64-byte boundary.
> + * @param expected_value
> + * Before attempting the monitoring, the `p` address may be read and
> compared
> + * against this value. If `value_mask` is zero, this step will be skipped.
> + * @param value_mask
> + * The 64-bit mask to use to extract current value from `p`.
> + * @param state
> + * Architecture-dependent optimized power state number. Can be 0 (C0.2) or
> + * 1 (C0.1).
> + * @param tsc_timestamp
> + * Maximum TSC timestamp to wait for.
> + *
> + * @return
> + * - 1 if wakeup was due to TSC timeout expiration.
> + * - 0 if wakeup was due to memory write or other reasons.
> + */
> +static inline int rte_power_monitor(const volatile void *p,
> + const uint64_t expected_value, const uint64_t value_mask,
> + const uint32_t state, const uint64_t tsc_timestamp)
> +{
> + const uint32_t tsc_l = (uint32_t)tsc_timestamp;
> + const uint32_t tsc_h = (uint32_t)(tsc_timestamp >> 32);
> + /* the rflags need match native register size */
> +#ifdef RTE_ARCH_I686
> + uint32_t rflags;
> +#else
> + uint64_t rflags;
> +#endif
> + /*
> + * we're using raw byte codes for now as only the newest compiler
> + * versions support this instruction natively.
> + */
> +
> + /* set address for UMONITOR */
> + asm volatile(".byte 0xf3, 0x0f, 0xae, 0xf7;"
> + :
> + : "D"(p));
> +
> + if (value_mask) {
> + const uint64_t cur_value = *(const volatile uint64_t *)p;
> + const uint64_t masked = cur_value & value_mask;
> + /* if the masked value is already matching, abort */
> + if (masked == expected_value)
> + return 0;
> + }
> + /* execute UMWAIT */
> + asm volatile(".byte 0xf2, 0x0f, 0xae, 0xf7;\n"
> + /*
> + * UMWAIT sets CF flag in RFLAGS, so PUSHF to push them
> + * onto the stack, then pop them back into `rflags` so that
> + * we can read it.
> + */
> + "pushf;\n"
> + "pop %0;\n"
> + : "=r"(rflags)
> + : "D"(state), "a"(tsc_l), "d"(tsc_h));
> +
> + /* we're interested in the first bit (the carry flag) */
> + return rflags & 0x1;
> +}
> +
> +/**
> + * Enter an architecture-defined optimized power state until a certain TSC
> + * timestamp is reached.
> + *
> + * This function uses TPAUSE instruction. For more information about its
> usage,
> + * please refer to Intel(R) 64 and IA-32 Architectures Software Developer's
> + * Manual.
> + *
> + * @param state
> + * Architecture-dependent optimized power state number. Can be 0 (C0.2) or
> + * 1 (C0.1).
> + * @param tsc_timestamp
> + * Maximum TSC timestamp to wait for.
> + *
> + * @return
> + * - 1 if wakeup was due to TSC timeout expiration.
> + * - 0 if wakeup was due to other reasons.
> + */
> +static inline int rte_power_pause(const uint32_t state,
> + const uint64_t tsc_timestamp)
> +{
> + const uint32_t tsc_l = (uint32_t)tsc_timestamp;
> + const uint32_t tsc_h = (uint32_t)(tsc_timestamp >> 32);
> + /* the rflags need match native register size */
> +#ifdef RTE_ARCH_I686
> + uint32_t rflags;
> +#else
> + uint64_t rflags;
> +#endif
> +
> + /* execute TPAUSE */
> + asm volatile(".byte 0x66, 0x0f, 0xae, 0xf7;\n"
> + /*
> + * TPAUSE sets CF flag in RFLAGS, so PUSHF to push them
> + * onto the stack, then pop them back into `rflags` so that
> + * we can read it.
> + */
> + "pushf;\n"
> + "pop %0;\n"
> + : "=r"(rflags)
> + : "D"(state), "a"(tsc_l), "d"(tsc_h));
> +
> + /* we're interested in the first bit (the carry flag) */
> + return rflags & 0x1;
> +}
> +
> +#ifdef __cplusplus
> +}
> +#endif
> +
> +#endif /* _RTE_POWER_INTRINSIC_X86_64_H_ */
