ceph/src/spdk/include/spdk/util.h

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright (c) Intel Corporation.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
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  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 /** \file
  35  * General utility functions
  36  */
  37
  38 #ifndef SPDK_UTIL_H
  39 #define SPDK_UTIL_H
  40
  41 #include "spdk/stdinc.h"
  42
  43 #ifdef __cplusplus
  44 extern "C" {
  45 #endif
  46
  47 #define spdk_min(a,b) (((a)<(b))?(a):(b))
  48 #define spdk_max(a,b) (((a)>(b))?(a):(b))
  49
  50 #define SPDK_COUNTOF(arr) (sizeof(arr) / sizeof((arr)[0]))
  51
  52 #define SPDK_CONTAINEROF(ptr, type, member) ((type *)((uintptr_t)ptr - offsetof(type, member)))
  53
  54 #define SPDK_SEC_TO_USEC 1000000ULL
  55
  56 static inline uint32_t
  57 spdk_u32log2(uint32_t x)
  58 {
  59         if (x == 0) {
  60                 /* log(0) is undefined */
  61                 return 0;
  62         }
  63         return 31u - __builtin_clz(x);
  64 }
  65
  66 static inline uint32_t
  67 spdk_align32pow2(uint32_t x)
  68 {
  69         return 1u << (1 + spdk_u32log2(x - 1));
  70 }
  71
  72 /**
  73  * Check if a uint32_t is a power of 2.
  74  */
  75 static inline bool
  76 spdk_u32_is_pow2(uint32_t x)
  77 {
  78         if (x == 0) {
  79                 return false;
  80         }
  81
  82         return (x & (x - 1)) == 0;
  83 }
  84
  85 #ifdef __cplusplus
  86 }
  87 #endif
  88
  89 #endif