linux_dsm_epyc7002/include/linux/prime_numbers.h
Chris Wilson cf4a7207b1 lib: Add a simple prime number generator
Prime numbers are interesting for testing components that use multiplies
and divides, such as testing DRM's struct drm_mm alignment computations.

v2: Move to lib/, add selftest
v3: Fix initial constants (exclude 0/1 from being primes)
v4: More RCU markup to keep 0day/sparse happy
v5: Fix RCU unwind on module exit, add to kselftests
v6: Tidy computation of bitmap size
v7: for_each_prime_number_from()
v8: Compose small-primes using BIT() for easier verification
v9: Move rcu dance entirely into callers.
v10: Improve quote for Betrand's Postulate (aka Chebyshev's theorem)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161222144514.3911-1-chris@chris-wilson.co.uk
2016-12-27 12:30:56 +01:00

38 lines
1.3 KiB
C

#ifndef __LINUX_PRIME_NUMBERS_H
#define __LINUX_PRIME_NUMBERS_H
#include <linux/types.h>
bool is_prime_number(unsigned long x);
unsigned long next_prime_number(unsigned long x);
/**
* for_each_prime_number - iterate over each prime upto a value
* @prime: the current prime number in this iteration
* @max: the upper limit
*
* Starting from the first prime number 2 iterate over each prime number up to
* the @max value. On each iteration, @prime is set to the current prime number.
* @max should be less than ULONG_MAX to ensure termination. To begin with
* @prime set to 1 on the first iteration use for_each_prime_number_from()
* instead.
*/
#define for_each_prime_number(prime, max) \
for_each_prime_number_from((prime), 2, (max))
/**
* for_each_prime_number_from - iterate over each prime upto a value
* @prime: the current prime number in this iteration
* @from: the initial value
* @max: the upper limit
*
* Starting from @from iterate over each successive prime number up to the
* @max value. On each iteration, @prime is set to the current prime number.
* @max should be less than ULONG_MAX, and @from less than @max, to ensure
* termination.
*/
#define for_each_prime_number_from(prime, from, max) \
for (prime = (from); prime <= (max); prime = next_prime_number(prime))
#endif /* !__LINUX_PRIME_NUMBERS_H */