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1 /*
2  * Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #ifndef UTILS_DEF_H
8 #define UTILS_DEF_H
9 
10 #include <export/lib/utils_def_exp.h>
11 
12 /* Compute the number of elements in the given array */
13 #define ARRAY_SIZE(a)				\
14 	(sizeof(a) / sizeof((a)[0]))
15 
16 #define IS_POWER_OF_TWO(x)			\
17 	(((x) & ((x) - 1)) == 0)
18 
19 #define SIZE_FROM_LOG2_WORDS(n)		(4 << (n))
20 
21 #define BIT_32(nr)			(U(1) << (nr))
22 #define BIT_64(nr)			(ULL(1) << (nr))
23 
24 #ifdef __aarch64__
25 #define BIT				BIT_64
26 #else
27 #define BIT				BIT_32
28 #endif
29 
30 /*
31  * Create a contiguous bitmask starting at bit position @l and ending at
32  * position @h. For example
33  * GENMASK_64(39, 21) gives us the 64bit vector 0x000000ffffe00000.
34  */
35 #if defined(__LINKER__) || defined(__ASSEMBLER__)
36 #define GENMASK_32(h, l) \
37 	(((0xFFFFFFFF) << (l)) & (0xFFFFFFFF >> (32 - 1 - (h))))
38 
39 #define GENMASK_64(h, l) \
40 	((~0 << (l)) & (~0 >> (64 - 1 - (h))))
41 #else
42 #define GENMASK_32(h, l) \
43 	(((~UINT32_C(0)) << (l)) & (~UINT32_C(0) >> (32 - 1 - (h))))
44 
45 #define GENMASK_64(h, l) \
46 	(((~UINT64_C(0)) << (l)) & (~UINT64_C(0) >> (64 - 1 - (h))))
47 #endif
48 
49 #ifdef __aarch64__
50 #define GENMASK				GENMASK_64
51 #else
52 #define GENMASK				GENMASK_32
53 #endif
54 
55 /*
56  * This variant of div_round_up can be used in macro definition but should not
57  * be used in C code as the `div` parameter is evaluated twice.
58  */
59 #define DIV_ROUND_UP_2EVAL(n, d)	(((n) + (d) - 1) / (d))
60 
61 #define div_round_up(val, div) __extension__ ({	\
62 	__typeof__(div) _div = (div);		\
63 	((val) + _div - (__typeof__(div)) 1) / _div;		\
64 })
65 
66 #define MIN(x, y) __extension__ ({	\
67 	__typeof__(x) _x = (x);		\
68 	__typeof__(y) _y = (y);		\
69 	(void)(&_x == &_y);		\
70 	_x < _y ? _x : _y;		\
71 })
72 
73 #define MAX(x, y) __extension__ ({	\
74 	__typeof__(x) _x = (x);		\
75 	__typeof__(y) _y = (y);		\
76 	(void)(&_x == &_y);		\
77 	_x > _y ? _x : _y;		\
78 })
79 
80 #define CLAMP(x, min, max) __extension__ ({ \
81 	__typeof__(x) _x = (x); \
82 	__typeof__(min) _min = (min); \
83 	__typeof__(max) _max = (max); \
84 	(void)(&_x == &_min); \
85 	(void)(&_x == &_max); \
86 	(_x > _max ? _max : (_x < _min ? _min : _x)); \
87 })
88 
89 /*
90  * The round_up() macro rounds up a value to the given boundary in a
91  * type-agnostic yet type-safe manner. The boundary must be a power of two.
92  * In other words, it computes the smallest multiple of boundary which is
93  * greater than or equal to value.
94  *
95  * round_down() is similar but rounds the value down instead.
96  */
97 #define round_boundary(value, boundary)		\
98 	((__typeof__(value))((boundary) - 1))
99 
100 #define round_up(value, boundary)		\
101 	((((value) - 1) | round_boundary(value, boundary)) + 1)
102 
103 #define round_down(value, boundary)		\
104 	((value) & ~round_boundary(value, boundary))
105 
106 /*
107  * Evaluates to 1 if (ptr + inc) overflows, 0 otherwise.
108  * Both arguments must be unsigned pointer values (i.e. uintptr_t).
109  */
110 #define check_uptr_overflow(_ptr, _inc)		\
111 	((_ptr) > (UINTPTR_MAX - (_inc)))
112 
113 /*
114  * Evaluates to 1 if (u32 + inc) overflows, 0 otherwise.
115  * Both arguments must be 32-bit unsigned integers (i.e. effectively uint32_t).
116  */
117 #define check_u32_overflow(_u32, _inc) \
118 	((_u32) > (UINT32_MAX - (_inc)))
119 
120 /* Register size of the current architecture. */
121 #ifdef __aarch64__
122 #define REGSZ		U(8)
123 #else
124 #define REGSZ		U(4)
125 #endif
126 
127 /*
128  * Test for the current architecture version to be at least the version
129  * expected.
130  */
131 #define ARM_ARCH_AT_LEAST(_maj, _min) \
132 	((ARM_ARCH_MAJOR > (_maj)) || \
133 	 ((ARM_ARCH_MAJOR == (_maj)) && (ARM_ARCH_MINOR >= (_min))))
134 
135 /*
136  * Import an assembly or linker symbol as a C expression with the specified
137  * type
138  */
139 #define IMPORT_SYM(type, sym, name) \
140 	extern char sym[];\
141 	static const __attribute__((unused)) type name = (type) sym;
142 
143 /*
144  * When the symbol is used to hold a pointer, its alignment can be asserted
145  * with this macro. For example, if there is a linker symbol that is going to
146  * be used as a 64-bit pointer, the value of the linker symbol must also be
147  * aligned to 64 bit. This macro makes sure this is the case.
148  */
149 #define ASSERT_SYM_PTR_ALIGN(sym) assert(((size_t)(sym) % __alignof__(*(sym))) == 0)
150 
151 #define COMPILER_BARRIER() __asm__ volatile ("" ::: "memory")
152 
153 /* Compiler builtin of GCC >= 9 and planned in llvm */
154 #ifdef __HAVE_SPECULATION_SAFE_VALUE
155 # define SPECULATION_SAFE_VALUE(var) __builtin_speculation_safe_value(var)
156 #else
157 # define SPECULATION_SAFE_VALUE(var) var
158 #endif
159 
160 #endif /* UTILS_DEF_H */
161