1 /* 2 * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are met: 6 * 7 * Redistributions of source code must retain the above copyright notice, this 8 * list of conditions and the following disclaimer. 9 * 10 * Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 14 * Neither the name of ARM nor the names of its contributors may be used 15 * to endorse or promote products derived from this software without specific 16 * prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #ifndef __UTILS_H__ 32 #define __UTILS_H__ 33 34 /* Compute the number of elements in the given array */ 35 #define ARRAY_SIZE(a) \ 36 (sizeof(a) / sizeof((a)[0])) 37 38 #define IS_POWER_OF_TWO(x) \ 39 (((x) & ((x) - 1)) == 0) 40 41 #define SIZE_FROM_LOG2_WORDS(n) (4 << (n)) 42 43 #define BIT(nr) (1UL << (nr)) 44 45 #define MIN(x, y) __extension__ ({ \ 46 __typeof__(x) _x = (x); \ 47 __typeof__(y) _y = (y); \ 48 (void)(&_x == &_y); \ 49 _x < _y ? _x : _y; \ 50 }) 51 52 #define MAX(x, y) __extension__ ({ \ 53 __typeof__(x) _x = (x); \ 54 __typeof__(y) _y = (y); \ 55 (void)(&_x == &_y); \ 56 _x > _y ? _x : _y; \ 57 }) 58 59 /* 60 * The round_up() macro rounds up a value to the given boundary in a 61 * type-agnostic yet type-safe manner. The boundary must be a power of two. 62 * In other words, it computes the smallest multiple of boundary which is 63 * greater than or equal to value. 64 * 65 * round_down() is similar but rounds the value down instead. 66 */ 67 #define round_boundary(value, boundary) \ 68 ((__typeof__(value))((boundary) - 1)) 69 70 #define round_up(value, boundary) \ 71 ((((value) - 1) | round_boundary(value, boundary)) + 1) 72 73 #define round_down(value, boundary) \ 74 ((value) & ~round_boundary(value, boundary)) 75 76 /* 77 * Evaluates to 1 if (ptr + inc) overflows, 0 otherwise. 78 * Both arguments must be unsigned pointer values (i.e. uintptr_t). 79 */ 80 #define check_uptr_overflow(ptr, inc) \ 81 (((ptr) > UINTPTR_MAX - (inc)) ? 1 : 0) 82 83 /* 84 * For those constants to be shared between C and other sources, apply a 'ull' 85 * suffix to the argument only in C, to avoid undefined or unintended behaviour. 86 * 87 * The GNU assembler and linker do not support the 'ull' suffix (it causes the 88 * build process to fail) therefore the suffix is omitted when used in linker 89 * scripts and assembler files. 90 */ 91 #if defined(__LINKER__) || defined(__ASSEMBLY__) 92 # define ULL(_x) (_x) 93 #else 94 # define ULL(_x) (_x##ull) 95 #endif 96 97 /* 98 * C code should be put in this part of the header to avoid breaking ASM files 99 * or linker scripts including it. 100 */ 101 #if !(defined(__LINKER__) || defined(__ASSEMBLY__)) 102 103 #include <types.h> 104 105 /* 106 * Fill a region of normal memory of size "length" in bytes with zero bytes. 107 * 108 * WARNING: This function can only operate on normal memory. This means that 109 * the MMU must be enabled when using this function. Otherwise, use 110 * zeromem. 111 */ 112 void zero_normalmem(void *mem, u_register_t length); 113 114 /* 115 * Fill a region of memory of size "length" in bytes with null bytes. 116 * 117 * Unlike zero_normalmem, this function has no restriction on the type of 118 * memory targeted and can be used for any device memory as well as normal 119 * memory. This function must be used instead of zero_normalmem when MMU is 120 * disabled. 121 * 122 * NOTE: When data cache and MMU are enabled, prefer zero_normalmem for faster 123 * zeroing. 124 */ 125 void zeromem(void *mem, u_register_t length); 126 #endif /* !(defined(__LINKER__) || defined(__ASSEMBLY__)) */ 127 128 #endif /* __UTILS_H__ */ 129