1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef __UTIL_H
18 #define __UTIL_H
19 #include <plat/plat.h>
20 #include "toolchain.h"
21 #include <limits.h>
22 #include <stdbool.h>
23 #include <stddef.h>
24
25 #define ARRAY_SIZE(a) (sizeof((a)) / sizeof((a)[0]))
26
27 #define UNUSED_PARAM(param) (void) (param)
28
29 #ifndef alignof
30 #define alignof(type) offsetof(struct { char x; type field; }, field)
31 #endif
32 /*
33 * this macro does not consume bytes from any segment; if condition is true it is a zero-sized array;
34 * if some compilers do try to allocate space for them we create a special section for those checks
35 * and discard this section at link time
36 */
37 #define C_STATIC_ASSERT(name, condition) \
38 static const char __attribute__((used, section(".static_assert"))) \
39 static_assert_check_ ## name [(condition) ? 0 : -1] = {}
40
41 #define unlikely(x) (x)
42 #define likely(x) (x)
43
44 #define container_of(addr, struct_name, field_name) \
45 ((struct_name *)((char *)(addr) - offsetof(struct_name, field_name)))
46
IS_POWER_OF_TWO(unsigned int n)47 static inline bool IS_POWER_OF_TWO(unsigned int n)
48 {
49 return !(n & (n - 1));
50 }
51
LOG2_FLOOR(unsigned int n)52 static inline int LOG2_FLOOR(unsigned int n)
53 {
54 if (UNLIKELY(n == 0))
55 return INT_MIN;
56
57 // floor(log2(n)) = MSB(n) = (# of bits) - (# of leading zeros) - 1
58 return 8 * sizeof(n) - CLZ(n) - 1;
59 }
60
LOG2_CEIL(unsigned int n)61 static inline int LOG2_CEIL(unsigned int n)
62 {
63 return IS_POWER_OF_TWO(n) ? LOG2_FLOOR(n) : LOG2_FLOOR(n) + 1;
64 }
65
66 #ifdef SYSCALL_VARARGS_PARAMS_PASSED_AS_PTRS
67 #define VA_LIST_TO_INTEGER(__vl) ((uintptr_t)(&__vl))
68 #define INTEGER_TO_VA_LIST(__ptr) (*(va_list*)(__ptr))
69 #else
70 #define VA_LIST_TO_INTEGER(__vl) (*(uintptr_t*)(&__vl))
71 #define INTEGER_TO_VA_LIST(__ptr) ({uintptr_t tmp = __ptr; (*(va_list*)(&tmp)); })
72 #endif
73
74 #endif /* __UTIL_H */
75