linux-imx

#define pr_fmt(fmt) "prime numbers: " fmt "\n"

​

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/prime_numbers.h>

#include <linux/slab.h>

​

#define bitmap_size(nbits) (BITS_TO_LONGS(nbits) * sizeof(unsigned long))

​

struct primes {

    struct rcu_head rcu;

    unsigned long last, sz;

    unsigned long primes[];

};

​

#if BITS_PER_LONG == 64

static const struct primes small_primes = {

    .last = 61,

    .sz = 64,

    .primes = {

        BIT(2) |

        BIT(3) |

        BIT(5) |

        BIT(7) |

        BIT(11) |

        BIT(13) |

        BIT(17) |

        BIT(19) |

        BIT(23) |

        BIT(29) |

        BIT(31) |

        BIT(37) |

        BIT(41) |

        BIT(43) |

        BIT(47) |

        BIT(53) |

        BIT(59) |

        BIT(61)

    }

};

#elif BITS_PER_LONG == 32

static const struct primes small_primes = {

    .last = 31,

    .sz = 32,

    .primes = {

        BIT(2) |

        BIT(3) |

        BIT(5) |

        BIT(7) |

        BIT(11) |

        BIT(13) |

        BIT(17) |

        BIT(19) |

        BIT(23) |

        BIT(29) |

        BIT(31)

    }

};

#else

#error "unhandled BITS_PER_LONG"

#endif

​

static DEFINE_MUTEX(lock);

static const struct primes __rcu *primes = RCU_INITIALIZER(&small_primes);

​

static unsigned long selftest_max;

​

static bool slow_is_prime_number(unsigned long x)

{

    unsigned long y = int_sqrt(x);

​

    while (y > 1) {

        if ((x % y) == 0)

            break;

        y--;

    }

​

    return y == 1;

}

​

static unsigned long slow_next_prime_number(unsigned long x)

{

    while (x < ULONG_MAX && !slow_is_prime_number(++x))

        ;

​

    return x;

}

​

static unsigned long clear_multiples(unsigned long x,

                     unsigned long *p,

                     unsigned long start,

                     unsigned long end)