f-stack/dpdk/lib/librte_eal/common/include/generic/rte_cpuflags.h

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2014 Intel Corporation
 */

#ifndef _RTE_CPUFLAGS_H_
#define _RTE_CPUFLAGS_H_

/**
 * @file
 * Architecture specific API to determine available CPU features at runtime.
 */

#include "rte_common.h"
#include <errno.h>

/**
 * Enumeration of all CPU features supported
 */
__extension__
enum rte_cpu_flag_t;

/**
 * Get name of CPU flag
 *
 * @param feature
 *     CPU flag ID
 * @return
 *     flag name
 *     NULL if flag ID is invalid
 */
__extension__
const char *
rte_cpu_get_flag_name(enum rte_cpu_flag_t feature);

/**
 * Function for checking a CPU flag availability
 *
 * @param feature
 *     CPU flag to query CPU for
 * @return
 *     1 if flag is available
 *     0 if flag is not available
 *     -ENOENT if flag is invalid
 */
__extension__
int
rte_cpu_get_flag_enabled(enum rte_cpu_flag_t feature);

/**
 * This function checks that the currently used CPU supports the CPU features
 * that were specified at compile time. It is called automatically within the
 * EAL, so does not need to be used by applications.
 */
__rte_deprecated
void
rte_cpu_check_supported(void);

/**
 * This function checks that the currently used CPU supports the CPU features
 * that were specified at compile time. It is called automatically within the
 * EAL, so does not need to be used by applications.  This version returns a
 * result so that decisions may be made (for instance, graceful shutdowns).
 */
int
rte_cpu_is_supported(void);

/**
 * This function attempts to retrieve a value from the auxiliary vector.
 * If it is unsuccessful, the result will be 0, and errno will be set.
 *
 * @return A value from the auxiliary vector.  When the value is 0, check
 * errno to determine if an error occurred.
 */
unsigned long
rte_cpu_getauxval(unsigned long type);

/**
 * This function retrieves a value from the auxiliary vector, and compares it
 * as a string against the value retrieved.
 *
 * @return The result of calling strcmp() against the value retrieved from
 * the auxiliary vector.  When the value is 0 (meaning a match is found),
 * check errno to determine if an error occurred.
 */
int
rte_cpu_strcmp_auxval(unsigned long type, const char *str);

#endif /* _RTE_CPUFLAGS_H_ */