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d3d3857f MJ |
1 | // SPDX-FileCopyrightText: 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
2 | // | |
3 | // SPDX-License-Identifier: LGPL-2.1-or-later | |
4 | ||
ec4e58a3 MD |
5 | #ifndef _URCU_COMPILER_H |
6 | #define _URCU_COMPILER_H | |
af02d47e MD |
7 | |
8 | /* | |
af02d47e | 9 | * Compiler definitions. |
af02d47e MD |
10 | */ |
11 | ||
49d7d158 MD |
12 | #include <stddef.h> /* for offsetof */ |
13 | ||
06326a94 SM |
14 | #if defined __cplusplus |
15 | # include <type_traits> /* for std::remove_cv */ | |
16 | #endif | |
17 | ||
a0b7f7ea MD |
18 | #define caa_likely(x) __builtin_expect(!!(x), 1) |
19 | #define caa_unlikely(x) __builtin_expect(!!(x), 0) | |
2dc5fa0f | 20 | |
e51500ed | 21 | #define cmm_barrier() __asm__ __volatile__ ("" : : : "memory") |
2dc5fa0f | 22 | |
af02d47e MD |
23 | /* |
24 | * Instruct the compiler to perform only a single access to a variable | |
25 | * (prohibits merging and refetching). The compiler is also forbidden to reorder | |
6cf3827c | 26 | * successive instances of CMM_ACCESS_ONCE(), but only when the compiler is aware of |
af02d47e | 27 | * particular ordering. Compiler ordering can be ensured, for example, by |
6cf3827c | 28 | * putting two CMM_ACCESS_ONCE() in separate C statements. |
af02d47e MD |
29 | * |
30 | * This macro does absolutely -nothing- to prevent the CPU from reordering, | |
31 | * merging, or refetching absolutely anything at any time. Its main intended | |
32 | * use is to mediate communication between process-level code and irq/NMI | |
33 | * handlers, all running on the same CPU. | |
34 | */ | |
e51500ed | 35 | #define CMM_ACCESS_ONCE(x) (*(__volatile__ __typeof__(x) *)&(x)) |
af02d47e | 36 | |
2f8a5ae7 MD |
37 | #ifndef caa_max |
38 | #define caa_max(a,b) ((a)>(b)?(a):(b)) | |
fdee2e6d MD |
39 | #endif |
40 | ||
2f8a5ae7 MD |
41 | #ifndef caa_min |
42 | #define caa_min(a,b) ((a)<(b)?(a):(b)) | |
fdee2e6d MD |
43 | #endif |
44 | ||
1b27a772 | 45 | #if defined(__SIZEOF_LONG__) |
06f22bdb | 46 | #define CAA_BITS_PER_LONG (__SIZEOF_LONG__ * 8) |
1b27a772 | 47 | #elif defined(_LP64) |
06f22bdb | 48 | #define CAA_BITS_PER_LONG 64 |
1b27a772 | 49 | #else |
06f22bdb | 50 | #define CAA_BITS_PER_LONG 32 |
1b27a772 PB |
51 | #endif |
52 | ||
b194c06e MD |
53 | /* |
54 | * caa_container_of - Get the address of an object containing a field. | |
55 | * | |
56 | * @ptr: pointer to the field. | |
57 | * @type: type of the object. | |
58 | * @member: name of the field within the object. | |
59 | */ | |
60 | #define caa_container_of(ptr, type, member) \ | |
1b85da85 | 61 | __extension__ \ |
453629a9 | 62 | ({ \ |
bdffa73a | 63 | const __typeof__(((type *) NULL)->member) * __ptr = (ptr); \ |
453629a9 MD |
64 | (type *)((char *)__ptr - offsetof(type, member)); \ |
65 | }) | |
66 | ||
4b3a7ebd MD |
67 | /* |
68 | * caa_container_of_check_null - Get the address of an object containing a field. | |
69 | * | |
70 | * @ptr: pointer to the field. | |
71 | * @type: type of the object. | |
72 | * @member: name of the field within the object. | |
73 | * | |
74 | * Return the address of the object containing the field. Return NULL if | |
75 | * @ptr is NULL. | |
76 | */ | |
77 | #define caa_container_of_check_null(ptr, type, member) \ | |
78 | __extension__ \ | |
79 | ({ \ | |
80 | const __typeof__(((type *) NULL)->member) * __ptr = (ptr); \ | |
81 | (__ptr) ? (type *)((char *)__ptr - offsetof(type, member)) : NULL; \ | |
82 | }) | |
83 | ||
78bec10c | 84 | #define CAA_BUILD_BUG_ON_ZERO(cond) (sizeof(struct { int:-!!(cond); })) |
9f59b220 | 85 | #define CAA_BUILD_BUG_ON(cond) ((void)CAA_BUILD_BUG_ON_ZERO(cond)) |
78bec10c | 86 | |
dc53e23e MD |
87 | /* |
88 | * __rcu is an annotation that documents RCU pointer accesses that need | |
89 | * to be protected by a read-side critical section. Eventually, a static | |
90 | * checker will be able to use this annotation to detect incorrect RCU | |
91 | * usage. | |
92 | */ | |
93 | #define __rcu | |
94 | ||
4501f284 | 95 | #ifdef __cplusplus |
06326a94 | 96 | #define URCU_FORCE_CAST(_type, arg) (reinterpret_cast<std::remove_cv<_type>::type>(arg)) |
4501f284 MD |
97 | #else |
98 | #define URCU_FORCE_CAST(type, arg) ((type) (arg)) | |
99 | #endif | |
100 | ||
4b5f005b | 101 | #define caa_is_signed_type(type) ((type) -1 < (type) 0) |
e56d99bf | 102 | |
4b5f005b | 103 | /* |
e4749953 MD |
104 | * Cast to unsigned long, sign-extending if @v is signed. |
105 | * Note: casting to a larger type or to same type size keeps the sign of | |
106 | * the expression being cast (see C99 6.3.1.3). | |
4b5f005b | 107 | */ |
e4749953 | 108 | #define caa_cast_long_keep_sign(v) ((unsigned long) (v)) |
e56d99bf | 109 | |
706d1165 | 110 | #if defined (__GNUC__) \ |
a0a0c4d5 EC |
111 | && ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5) \ |
112 | || __GNUC__ >= 5) | |
706d1165 MD |
113 | #define CDS_DEPRECATED(msg) \ |
114 | __attribute__((deprecated(msg))) | |
115 | #else | |
116 | #define CDS_DEPRECATED(msg) \ | |
117 | __attribute__((deprecated)) | |
118 | #endif | |
119 | ||
e323ceac MD |
120 | #define CAA_ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) |
121 | ||
1b4fed78 MJ |
122 | /* |
123 | * URCU_GCC_VERSION is used to blacklist specific GCC versions with known | |
124 | * bugs, clang also defines these macros to an equivalent GCC version it | |
125 | * claims to support, so exclude it. | |
126 | */ | |
127 | #if defined(__GNUC__) && !defined(__clang__) | |
4b79310a MD |
128 | # define URCU_GCC_VERSION (__GNUC__ * 10000 \ |
129 | + __GNUC_MINOR__ * 100 \ | |
130 | + __GNUC_PATCHLEVEL__) | |
4b79310a MD |
131 | #endif |
132 | ||
ec4e58a3 | 133 | #endif /* _URCU_COMPILER_H */ |