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 62