fs/btrfs/misc.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 #ifndef BTRFS_MISC_H
   4 #define BTRFS_MISC_H
   5
   6 #include <linux/sched.h>
   7 #include <linux/wait.h>
   8 #include <asm/div64.h>
   9
  10 #define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
  11
  12 static inline void cond_wake_up(struct wait_queue_head *wq)
  13 {
  14         /*
  15          * This implies a full smp_mb barrier, see comments for
  16          * waitqueue_active why.
  17          */
  18         if (wq_has_sleeper(wq))
  19                 wake_up(wq);
  20 }
  21
  22 static inline void cond_wake_up_nomb(struct wait_queue_head *wq)
  23 {
  24         /*
  25          * Special case for conditional wakeup where the barrier required for
  26          * waitqueue_active is implied by some of the preceding code. Eg. one
  27          * of such atomic operations (atomic_dec_and_return, ...), or a
  28          * unlock/lock sequence, etc.
  29          */
  30         if (waitqueue_active(wq))
  31                 wake_up(wq);
  32 }
  33
  34 static inline u64 div_factor(u64 num, int factor)
  35 {
  36         if (factor == 10)
  37                 return num;
  38         num *= factor;
  39         return div_u64(num, 10);
  40 }
  41
  42 static inline u64 div_factor_fine(u64 num, int factor)
  43 {
  44         if (factor == 100)
  45                 return num;
  46         num *= factor;
  47         return div_u64(num, 100);
  48 }
  49
  50 /* Copy of is_power_of_two that is 64bit safe */
  51 static inline bool is_power_of_two_u64(u64 n)
  52 {
  53         return n != 0 && (n & (n - 1)) == 0;
  54 }
  55
  56 static inline bool has_single_bit_set(u64 n)
  57 {
  58         return is_power_of_two_u64(n);
  59 }
  60
  61 #endif