xref: /dpdk/lib/eal/include/generic/rte_cpuflags.h (revision 7917b0d38e92e8b9ec5a870415b791420e10f11a)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4 
5 #ifndef _RTE_CPUFLAGS_H_
6 #define _RTE_CPUFLAGS_H_
7 
8 /**
9  * @file
10  * Architecture specific API to determine available CPU features at runtime.
11  */
12 
13 #include "rte_common.h"
14 #include <errno.h>
15 
16 #include <rte_compat.h>
17 
18 #ifdef __cplusplus
19 extern "C" {
20 #endif
21 
22 /**
23  * Structure used to describe platform-specific intrinsics that may or may not
24  * be supported at runtime.
25  */
26 struct rte_cpu_intrinsics {
27 	uint32_t power_monitor : 1;
28 	/**< indicates support for rte_power_monitor function */
29 	uint32_t power_pause : 1;
30 	/**< indicates support for rte_power_pause function */
31 	uint32_t power_monitor_multi : 1;
32 	/**< indicates support for rte_power_monitor_multi function */
33 };
34 
35 /**
36  * @warning
37  * @b EXPERIMENTAL: this API may change without prior notice
38  *
39  * Check CPU support for various intrinsics at runtime.
40  *
41  * @param intrinsics
42  *     Pointer to a structure to be filled.
43  */
44 __rte_experimental
45 void
46 rte_cpu_get_intrinsics_support(struct rte_cpu_intrinsics *intrinsics);
47 
48 /**
49  * Enumeration of all CPU features supported
50  */
51 __extension__
52 enum rte_cpu_flag_t;
53 
54 /**
55  * Get name of CPU flag
56  *
57  * @param feature
58  *     CPU flag ID
59  * @return
60  *     flag name
61  *     NULL if flag ID is invalid
62  */
63 __extension__
64 const char *
65 rte_cpu_get_flag_name(enum rte_cpu_flag_t feature);
66 
67 /**
68  * Function for checking a CPU flag availability
69  *
70  * @param feature
71  *     CPU flag to query CPU for
72  * @return
73  *     1 if flag is available
74  *     0 if flag is not available
75  *     -ENOENT if flag is invalid
76  */
77 __extension__
78 int
79 rte_cpu_get_flag_enabled(enum rte_cpu_flag_t feature);
80 
81 /**
82  * This function checks that the currently used CPU supports the CPU features
83  * that were specified at compile time. It is called automatically within the
84  * EAL, so does not need to be used by applications.  This version returns a
85  * result so that decisions may be made (for instance, graceful shutdowns).
86  */
87 int
88 rte_cpu_is_supported(void);
89 
90 /**
91  * This function attempts to retrieve a value from the auxiliary vector.
92  * If it is unsuccessful, the result will be 0, and errno will be set.
93  *
94  * @return A value from the auxiliary vector.  When the value is 0, check
95  * errno to determine if an error occurred.
96  */
97 unsigned long
98 rte_cpu_getauxval(unsigned long type);
99 
100 /**
101  * This function retrieves a value from the auxiliary vector, and compares it
102  * as a string against the value retrieved.
103  *
104  * @return The result of calling strcmp() against the value retrieved from
105  * the auxiliary vector.  When the value is 0 (meaning a match is found),
106  * check errno to determine if an error occurred.
107  */
108 int
109 rte_cpu_strcmp_auxval(unsigned long type, const char *str);
110 
111 #ifdef __cplusplus
112 }
113 #endif
114 
115 #endif /* _RTE_CPUFLAGS_H_ */
116