1 /*
2  * Copyright (c) 2016-2023, Arm Limited and Contributors. All rights reserved.
3  * Copyright (c) 2020, NVIDIA Corporation. All rights reserved.
4  *
5  * SPDX-License-Identifier: BSD-3-Clause
6  */
7 
8 #ifndef UTILS_DEF_H
9 #define UTILS_DEF_H
10 
11 #include <export/lib/utils_def_exp.h>
12 
13 /* Compute the number of elements in the given array */
14 #define ARRAY_SIZE(a)				\
15 	(sizeof(a) / sizeof((a)[0]))
16 
17 #define IS_POWER_OF_TWO(x)			\
18 	(((x) & ((x) - 1)) == 0)
19 
20 #define SIZE_FROM_LOG2_WORDS(n)		(U(4) << (n))
21 
22 #define BIT_32(nr)			(U(1) << (nr))
23 #define BIT_64(nr)			(ULL(1) << (nr))
24 
25 #ifdef __aarch64__
26 #define BIT				BIT_64
27 #else
28 #define BIT				BIT_32
29 #endif
30 
31 /*
32  * Create a contiguous bitmask starting at bit position @l and ending at
33  * position @h. For example
34  * GENMASK_64(39, 21) gives us the 64bit vector 0x000000ffffe00000.
35  */
36 #if defined(__LINKER__) || defined(__ASSEMBLER__)
37 #define GENMASK_32(h, l) \
38 	(((0xFFFFFFFF) << (l)) & (0xFFFFFFFF >> (32 - 1 - (h))))
39 
40 #define GENMASK_64(h, l) \
41 	((~0 << (l)) & (~0 >> (64 - 1 - (h))))
42 #else
43 #define GENMASK_32(h, l) \
44 	(((~UINT32_C(0)) << (l)) & (~UINT32_C(0) >> (32 - 1 - (h))))
45 
46 #define GENMASK_64(h, l) \
47 	(((~UINT64_C(0)) << (l)) & (~UINT64_C(0) >> (64 - 1 - (h))))
48 #endif
49 
50 #ifdef __aarch64__
51 #define GENMASK				GENMASK_64
52 #else
53 #define GENMASK				GENMASK_32
54 #endif
55 
56 /*
57  * This variant of div_round_up can be used in macro definition but should not
58  * be used in C code as the `div` parameter is evaluated twice.
59  */
60 #define DIV_ROUND_UP_2EVAL(n, d)	(((n) + (d) - 1) / (d))
61 
62 #define div_round_up(val, div) __extension__ ({	\
63 	__typeof__(div) _div = (div);		\
64 	((val) + _div - (__typeof__(div)) 1) / _div;		\
65 })
66 
67 #define MIN(x, y) __extension__ ({	\
68 	__typeof__(x) _x = (x);		\
69 	__typeof__(y) _y = (y);		\
70 	(void)(&_x == &_y);		\
71 	(_x < _y) ? _x : _y;		\
72 })
73 
74 #define MAX(x, y) __extension__ ({	\
75 	__typeof__(x) _x = (x);		\
76 	__typeof__(y) _y = (y);		\
77 	(void)(&_x == &_y);		\
78 	(_x > _y) ? _x : _y;		\
79 })
80 
81 #define CLAMP(x, min, max) __extension__ ({ \
82 	__typeof__(x) _x = (x); \
83 	__typeof__(min) _min = (min); \
84 	__typeof__(max) _max = (max); \
85 	(void)(&_x == &_min); \
86 	(void)(&_x == &_max); \
87 	((_x > _max) ? _max : ((_x < _min) ? _min : _x)); \
88 })
89 
90 /*
91  * The round_up() macro rounds up a value to the given boundary in a
92  * type-agnostic yet type-safe manner. The boundary must be a power of two.
93  * In other words, it computes the smallest multiple of boundary which is
94  * greater than or equal to value.
95  *
96  * round_down() is similar but rounds the value down instead.
97  */
98 #define round_boundary(value, boundary)		\
99 	((__typeof__(value))((boundary) - 1))
100 
101 #define round_up(value, boundary)		\
102 	((((value) - 1) | round_boundary(value, boundary)) + 1)
103 
104 #define round_down(value, boundary)		\
105 	((value) & ~round_boundary(value, boundary))
106 
107 /* add operation together with checking whether the operation overflowed
108  * The result is '*res',
109  * return 0 on success and 1 on overflow
110  */
111 #define add_overflow(a, b, res) __builtin_add_overflow((a), (b), (res))
112 
113 /*
114  * Round up a value to align with a given size and
115  * check whether overflow happens.
116  * The rounduped value is '*res',
117  * return 0 on success and 1 on overflow
118  */
119 #define round_up_overflow(v, size, res) (__extension__({ \
120 	typeof(res) __res = res; \
121 	typeof(*(__res)) __roundup_tmp = 0; \
122 	typeof(v) __roundup_mask = (typeof(v))(size) - 1; \
123 	\
124 	add_overflow((v), __roundup_mask, &__roundup_tmp) ? 1 : \
125 		(void)(*(__res) = __roundup_tmp & ~__roundup_mask), 0; \
126 }))
127 
128 /*
129  * Add a with b, then round up the result to align with a given size and
130  * check whether overflow happens.
131  * The rounduped value is '*res',
132  * return 0 on success and 1 on overflow
133  */
134 #define add_with_round_up_overflow(a, b, size, res) (__extension__({ \
135 	typeof(a) __a = (a); \
136 	typeof(__a) __add_res = 0; \
137 	\
138 	add_overflow((__a), (b), &__add_res) ? 1 : \
139 		round_up_overflow(__add_res, (size), (res)) ? 1 : 0; \
140 }))
141 
142 /**
143  * Helper macro to ensure a value lies on a given boundary.
144  */
145 #define is_aligned(value, boundary)			\
146 	(round_up((uintptr_t) value, boundary) ==	\
147 	 round_down((uintptr_t) value, boundary))
148 
149 /*
150  * Evaluates to 1 if (ptr + inc) overflows, 0 otherwise.
151  * Both arguments must be unsigned pointer values (i.e. uintptr_t).
152  */
153 #define check_uptr_overflow(_ptr, _inc)		\
154 	((_ptr) > (UINTPTR_MAX - (_inc)))
155 
156 /*
157  * Evaluates to 1 if (u32 + inc) overflows, 0 otherwise.
158  * Both arguments must be 32-bit unsigned integers (i.e. effectively uint32_t).
159  */
160 #define check_u32_overflow(_u32, _inc) \
161 	((_u32) > (UINT32_MAX - (_inc)))
162 
163 /* Register size of the current architecture. */
164 #ifdef __aarch64__
165 #define REGSZ		U(8)
166 #else
167 #define REGSZ		U(4)
168 #endif
169 
170 /*
171  * Test for the current architecture version to be at least the version
172  * expected.
173  */
174 #define ARM_ARCH_AT_LEAST(_maj, _min) \
175 	((ARM_ARCH_MAJOR > (_maj)) || \
176 	 ((ARM_ARCH_MAJOR == (_maj)) && (ARM_ARCH_MINOR >= (_min))))
177 
178 /*
179  * Import an assembly or linker symbol as a C expression with the specified
180  * type
181  */
182 #define IMPORT_SYM(type, sym, name) \
183 	extern char sym[];\
184 	static const __attribute__((unused)) type name = (type) sym;
185 
186 /*
187  * When the symbol is used to hold a pointer, its alignment can be asserted
188  * with this macro. For example, if there is a linker symbol that is going to
189  * be used as a 64-bit pointer, the value of the linker symbol must also be
190  * aligned to 64 bit. This macro makes sure this is the case.
191  */
192 #define ASSERT_SYM_PTR_ALIGN(sym) assert(((size_t)(sym) % __alignof__(*(sym))) == 0)
193 
194 #define COMPILER_BARRIER() __asm__ volatile ("" ::: "memory")
195 
196 /* Compiler builtin of GCC >= 9 and planned in llvm */
197 #ifdef __HAVE_SPECULATION_SAFE_VALUE
198 # define SPECULATION_SAFE_VALUE(var) __builtin_speculation_safe_value(var)
199 #else
200 # define SPECULATION_SAFE_VALUE(var) var
201 #endif
202 
203 /*
204  * Ticks elapsed in one second with a signal of 1 MHz
205  */
206 #define MHZ_TICKS_PER_SEC	U(1000000)
207 
208 /*
209  * Ticks elapsed in one second with a signal of 1 KHz
210  */
211 #define KHZ_TICKS_PER_SEC U(1000)
212 
213 #endif /* UTILS_DEF_H */
214