xref: /dpdk/lib/eal/include/generic/rte_cpuflags.h (revision 86a308fffa7752e460dcc9d8dba632f21ec3a8f3)
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  * Check CPU support for various intrinsics at runtime.
37  *
38  * @param intrinsics
39  *     Pointer to a structure to be filled.
40  */
41 void
42 rte_cpu_get_intrinsics_support(struct rte_cpu_intrinsics *intrinsics);
43 
44 /**
45  * Enumeration of all CPU features supported
46  */
47 __extension__
48 enum rte_cpu_flag_t;
49 
50 /**
51  * Get name of CPU flag
52  *
53  * @param feature
54  *     CPU flag ID
55  * @return
56  *     flag name
57  *     NULL if flag ID is invalid
58  */
59 __extension__
60 const char *
61 rte_cpu_get_flag_name(enum rte_cpu_flag_t feature);
62 
63 /**
64  * Function for checking a CPU flag availability
65  *
66  * @param feature
67  *     CPU flag to query CPU for
68  * @return
69  *     1 if flag is available
70  *     0 if flag is not available
71  *     -ENOENT if flag is invalid
72  */
73 __extension__
74 int
75 rte_cpu_get_flag_enabled(enum rte_cpu_flag_t feature);
76 
77 /**
78  * This function checks that the currently used CPU supports the CPU features
79  * that were specified at compile time. It is called automatically within the
80  * EAL, so does not need to be used by applications.  This version returns a
81  * result so that decisions may be made (for instance, graceful shutdowns).
82  */
83 int
84 rte_cpu_is_supported(void);
85 
86 /**
87  * This function attempts to retrieve a value from the auxiliary vector.
88  * If it is unsuccessful, the result will be 0, and errno will be set.
89  *
90  * @return A value from the auxiliary vector.  When the value is 0, check
91  * errno to determine if an error occurred.
92  */
93 unsigned long
94 rte_cpu_getauxval(unsigned long type);
95 
96 /**
97  * This function retrieves a value from the auxiliary vector, and compares it
98  * as a string against the value retrieved.
99  *
100  * @return The result of calling strcmp() against the value retrieved from
101  * the auxiliary vector.  When the value is 0 (meaning a match is found),
102  * check errno to determine if an error occurred.
103  */
104 int
105 rte_cpu_strcmp_auxval(unsigned long type, const char *str);
106 
107 #ifdef __cplusplus
108 }
109 #endif
110 
111 #endif /* _RTE_CPUFLAGS_H_ */
112