util_macros.h

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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_HELPER_MACROS_H_
#define _LINUX_HELPER_MACROS_H_
 
#include <linux/compiler_attributes.h>
#include <linux/math.h>
#include <linux/typecheck.h>
#include <linux/stddef.h>
 
#define for_each_if(condition) if (!(condition)) {} else
 
#define find_closest(x, a, as)                      \
({                                  \
    typeof(as) __fc_i, __fc_as = (as) - 1;              \
    long __fc_mid_x, __fc_x = (x);                  \
    long __fc_left, __fc_right;                 \
    typeof(*a) const *__fc_a = (a);                 \
    for (__fc_i = 0; __fc_i < __fc_as; __fc_i++) {          \
        __fc_mid_x = (__fc_a[__fc_i] + __fc_a[__fc_i + 1]) / 2; \
        if (__fc_x <= __fc_mid_x) {             \
            __fc_left = __fc_x - __fc_a[__fc_i];        \
            __fc_right = __fc_a[__fc_i + 1] - __fc_x;   \
            if (__fc_right < __fc_left)         \
                __fc_i++;               \
            break;                      \
        }                           \
    }                               \
    (__fc_i);                           \
})
 
#define find_closest_descending(x, a, as)               \
({                                  \
    typeof(as) __fc_i, __fc_as = (as) - 1;              \
    long __fc_mid_x, __fc_x = (x);                  \
    long __fc_left, __fc_right;                 \
    typeof(*a) const *__fc_a = (a);                 \
    for (__fc_i = __fc_as; __fc_i >= 1; __fc_i--) {         \
        __fc_mid_x = (__fc_a[__fc_i] + __fc_a[__fc_i - 1]) / 2; \
        if (__fc_x <= __fc_mid_x) {             \
            __fc_left = __fc_x - __fc_a[__fc_i];        \
            __fc_right = __fc_a[__fc_i - 1] - __fc_x;   \
            if (__fc_right < __fc_left)         \
                __fc_i--;               \
            break;                      \
        }                           \
    }                               \
    (__fc_i);                           \
})
 
#define PTR_IF(cond, ptr)   ((cond) ? (ptr) : NULL)
 
#define u64_to_user_ptr(x)      \
({                  \
    typecheck(u64, (x));        \
    (void __user *)(uintptr_t)(x);  \
})
 
#define is_insidevar(ptr, var)                      \
    ((uintptr_t)(ptr) >= (uintptr_t)(var) &&            \
     (uintptr_t)(ptr) <  (uintptr_t)(var) + sizeof(var))
 
#endif