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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
95d11952 BG |
2 | #ifndef _LINUX_HELPER_MACROS_H_ |
3 | #define _LINUX_HELPER_MACROS_H_ | |
4 | ||
9456d539 AS |
5 | #include <linux/math.h> |
6 | ||
95d11952 BG |
7 | #define __find_closest(x, a, as, op) \ |
8 | ({ \ | |
9 | typeof(as) __fc_i, __fc_as = (as) - 1; \ | |
10 | typeof(x) __fc_x = (x); \ | |
05836c37 | 11 | typeof(*a) const *__fc_a = (a); \ |
95d11952 BG |
12 | for (__fc_i = 0; __fc_i < __fc_as; __fc_i++) { \ |
13 | if (__fc_x op DIV_ROUND_CLOSEST(__fc_a[__fc_i] + \ | |
14 | __fc_a[__fc_i + 1], 2)) \ | |
15 | break; \ | |
16 | } \ | |
17 | (__fc_i); \ | |
18 | }) | |
19 | ||
20 | /** | |
21 | * find_closest - locate the closest element in a sorted array | |
22 | * @x: The reference value. | |
23 | * @a: The array in which to look for the closest element. Must be sorted | |
24 | * in ascending order. | |
25 | * @as: Size of 'a'. | |
26 | * | |
27 | * Returns the index of the element closest to 'x'. | |
28 | */ | |
29 | #define find_closest(x, a, as) __find_closest(x, a, as, <=) | |
30 | ||
31 | /** | |
32 | * find_closest_descending - locate the closest element in a sorted array | |
33 | * @x: The reference value. | |
34 | * @a: The array in which to look for the closest element. Must be sorted | |
35 | * in descending order. | |
36 | * @as: Size of 'a'. | |
37 | * | |
38 | * Similar to find_closest() but 'a' is expected to be sorted in descending | |
39 | * order. | |
40 | */ | |
41 | #define find_closest_descending(x, a, as) __find_closest(x, a, as, >=) | |
42 | ||
ddce1e09 JS |
43 | /** |
44 | * is_insidevar - check if the @ptr points inside the @var memory range. | |
45 | * @ptr: the pointer to a memory address. | |
46 | * @var: the variable which address and size identify the memory range. | |
47 | * | |
48 | * Evaluates to true if the address in @ptr lies within the memory | |
49 | * range allocated to @var. | |
50 | */ | |
51 | #define is_insidevar(ptr, var) \ | |
52 | ((uintptr_t)(ptr) >= (uintptr_t)(var) && \ | |
53 | (uintptr_t)(ptr) < (uintptr_t)(var) + sizeof(var)) | |
54 | ||
95d11952 | 55 | #endif |