1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_PRIME_NUMBERS_H
3 #define __LINUX_PRIME_NUMBERS_H
4 
5 #include <linux/types.h>
6 
7 bool is_prime_number(unsigned long x);
8 unsigned long next_prime_number(unsigned long x);
9 
10 /**
11  * for_each_prime_number - iterate over each prime upto a value
12  * @prime: the current prime number in this iteration
13  * @max: the upper limit
14  *
15  * Starting from the first prime number 2 iterate over each prime number up to
16  * the @max value. On each iteration, @prime is set to the current prime number.
17  * @max should be less than ULONG_MAX to ensure termination. To begin with
18  * @prime set to 1 on the first iteration use for_each_prime_number_from()
19  * instead.
20  */
21 #define for_each_prime_number(prime, max) \
22 	for_each_prime_number_from((prime), 2, (max))
23 
24 /**
25  * for_each_prime_number_from - iterate over each prime upto a value
26  * @prime: the current prime number in this iteration
27  * @from: the initial value
28  * @max: the upper limit
29  *
30  * Starting from @from iterate over each successive prime number up to the
31  * @max value. On each iteration, @prime is set to the current prime number.
32  * @max should be less than ULONG_MAX, and @from less than @max, to ensure
33  * termination.
34  */
35 #define for_each_prime_number_from(prime, from, max) \
36 	for (prime = (from); prime <= (max); prime = next_prime_number(prime))
37 
38 #endif /* !__LINUX_PRIME_NUMBERS_H */
39