f-stack/dpdk/lib/librte_eal/include/generic/rte_power_intrinsics.h

124 lines
4.6 KiB
C

/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2020 Intel Corporation
*/
#ifndef _RTE_POWER_INTRINSIC_H_
#define _RTE_POWER_INTRINSIC_H_
#include <inttypes.h>
#include <rte_compat.h>
#include <rte_spinlock.h>
/**
* @file
* Advanced power management operations.
*
* This file define APIs for advanced power management,
* which are architecture-dependent.
*/
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* 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, a certain TSC timestamp is reached, or other
* reasons cause the CPU to wake up.
*
* 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.
*
* @warning It is responsibility of the user to check if this function is
* supported at runtime using `rte_cpu_get_intrinsics_support()` API call.
* Failing to do so may result in an illegal CPU instruction error.
*
* @param p
* Address to monitor for changes.
* @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 tsc_timestamp
* Maximum TSC timestamp to wait for. Note that the wait behavior is
* architecture-dependent.
* @param data_sz
* Data size (in bytes) that will be used to compare expected value with the
* memory address. Can be 1, 2, 4 or 8. Supplying any other value will lead
* to undefined result.
*/
__rte_experimental
static inline void rte_power_monitor(const volatile void *p,
const uint64_t expected_value, const uint64_t value_mask,
const uint64_t tsc_timestamp, const uint8_t data_sz);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* 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, a certain TSC timestamp is reached, or other
* reasons cause the CPU to wake up.
*
* 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 call will also lock a spinlock on entering sleep, and release it on
* waking up the CPU.
*
* @warning It is responsibility of the user to check if this function is
* supported at runtime using `rte_cpu_get_intrinsics_support()` API call.
* Failing to do so may result in an illegal CPU instruction error.
*
* @param p
* Address to monitor for changes.
* @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 tsc_timestamp
* Maximum TSC timestamp to wait for. Note that the wait behavior is
* architecture-dependent.
* @param data_sz
* Data size (in bytes) that will be used to compare expected value with the
* memory address. Can be 1, 2, 4 or 8. Supplying any other value will lead
* to undefined result.
* @param lck
* A spinlock that must be locked before entering the function, will be
* unlocked while the CPU is sleeping, and will be locked again once the CPU
* wakes up.
*/
__rte_experimental
static inline void rte_power_monitor_sync(const volatile void *p,
const uint64_t expected_value, const uint64_t value_mask,
const uint64_t tsc_timestamp, const uint8_t data_sz,
rte_spinlock_t *lck);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Enter an architecture-defined optimized power state until a certain TSC
* timestamp is reached.
*
* @warning It is responsibility of the user to check if this function is
* supported at runtime using `rte_cpu_get_intrinsics_support()` API call.
* Failing to do so may result in an illegal CPU instruction error.
*
* @param tsc_timestamp
* Maximum TSC timestamp to wait for. Note that the wait behavior is
* architecture-dependent.
*/
__rte_experimental
static inline void rte_power_pause(const uint64_t tsc_timestamp);
#endif /* _RTE_POWER_INTRINSIC_H_ */