1 | /*- |
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2 | * Copyright (c) 2010 Isilon Systems, Inc. |
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3 | * Copyright (c) 2010 iX Systems, Inc. |
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4 | * Copyright (c) 2010 Panasas, Inc. |
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5 | * Copyright (c) 2013-2015 Mellanox Technologies, Ltd. |
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6 | * All rights reserved. |
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7 | * |
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8 | * Redistribution and use in source and binary forms, with or without |
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9 | * modification, are permitted provided that the following conditions |
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10 | * are met: |
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11 | * 1. Redistributions of source code must retain the above copyright |
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12 | * notice unmodified, this list of conditions, and the following |
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13 | * disclaimer. |
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14 | * 2. Redistributions in binary form must reproduce the above copyright |
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15 | * notice, this list of conditions and the following disclaimer in the |
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16 | * documentation and/or other materials provided with the distribution. |
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17 | * |
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18 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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19 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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20 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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21 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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22 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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23 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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24 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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25 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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26 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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27 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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28 | * |
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29 | * $FreeBSD$ |
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30 | */ |
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31 | #ifndef _LINUX_LOG2_H_ |
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32 | #define _LINUX_LOG2_H_ |
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33 | |
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34 | #include <linux/types.h> |
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35 | |
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36 | #include <sys/libkern.h> |
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37 | |
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38 | static inline unsigned long |
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39 | roundup_pow_of_two(unsigned long x) |
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40 | { |
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41 | return (1UL << flsl(x - 1)); |
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42 | } |
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43 | |
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44 | static inline int |
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45 | is_power_of_2(unsigned long n) |
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46 | { |
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47 | return (n == roundup_pow_of_two(n)); |
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48 | } |
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49 | |
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50 | static inline unsigned long |
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51 | rounddown_pow_of_two(unsigned long x) |
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52 | { |
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53 | return (1UL << (flsl(x) - 1)); |
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54 | } |
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55 | |
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56 | #define ilog2(n) \ |
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57 | ( \ |
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58 | __builtin_constant_p(n) ? ( \ |
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59 | (n) < 1 ? -1 : \ |
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60 | (n) & (1ULL << 63) ? 63 : \ |
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61 | (n) & (1ULL << 62) ? 62 : \ |
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62 | (n) & (1ULL << 61) ? 61 : \ |
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63 | (n) & (1ULL << 60) ? 60 : \ |
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64 | (n) & (1ULL << 59) ? 59 : \ |
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65 | (n) & (1ULL << 58) ? 58 : \ |
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66 | (n) & (1ULL << 57) ? 57 : \ |
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67 | (n) & (1ULL << 56) ? 56 : \ |
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68 | (n) & (1ULL << 55) ? 55 : \ |
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69 | (n) & (1ULL << 54) ? 54 : \ |
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70 | (n) & (1ULL << 53) ? 53 : \ |
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71 | (n) & (1ULL << 52) ? 52 : \ |
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72 | (n) & (1ULL << 51) ? 51 : \ |
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73 | (n) & (1ULL << 50) ? 50 : \ |
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74 | (n) & (1ULL << 49) ? 49 : \ |
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75 | (n) & (1ULL << 48) ? 48 : \ |
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76 | (n) & (1ULL << 47) ? 47 : \ |
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77 | (n) & (1ULL << 46) ? 46 : \ |
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78 | (n) & (1ULL << 45) ? 45 : \ |
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79 | (n) & (1ULL << 44) ? 44 : \ |
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80 | (n) & (1ULL << 43) ? 43 : \ |
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81 | (n) & (1ULL << 42) ? 42 : \ |
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82 | (n) & (1ULL << 41) ? 41 : \ |
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83 | (n) & (1ULL << 40) ? 40 : \ |
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84 | (n) & (1ULL << 39) ? 39 : \ |
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85 | (n) & (1ULL << 38) ? 38 : \ |
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86 | (n) & (1ULL << 37) ? 37 : \ |
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87 | (n) & (1ULL << 36) ? 36 : \ |
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88 | (n) & (1ULL << 35) ? 35 : \ |
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89 | (n) & (1ULL << 34) ? 34 : \ |
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90 | (n) & (1ULL << 33) ? 33 : \ |
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91 | (n) & (1ULL << 32) ? 32 : \ |
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92 | (n) & (1ULL << 31) ? 31 : \ |
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93 | (n) & (1ULL << 30) ? 30 : \ |
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94 | (n) & (1ULL << 29) ? 29 : \ |
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95 | (n) & (1ULL << 28) ? 28 : \ |
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96 | (n) & (1ULL << 27) ? 27 : \ |
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97 | (n) & (1ULL << 26) ? 26 : \ |
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98 | (n) & (1ULL << 25) ? 25 : \ |
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99 | (n) & (1ULL << 24) ? 24 : \ |
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100 | (n) & (1ULL << 23) ? 23 : \ |
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101 | (n) & (1ULL << 22) ? 22 : \ |
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102 | (n) & (1ULL << 21) ? 21 : \ |
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103 | (n) & (1ULL << 20) ? 20 : \ |
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104 | (n) & (1ULL << 19) ? 19 : \ |
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105 | (n) & (1ULL << 18) ? 18 : \ |
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106 | (n) & (1ULL << 17) ? 17 : \ |
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107 | (n) & (1ULL << 16) ? 16 : \ |
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108 | (n) & (1ULL << 15) ? 15 : \ |
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109 | (n) & (1ULL << 14) ? 14 : \ |
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110 | (n) & (1ULL << 13) ? 13 : \ |
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111 | (n) & (1ULL << 12) ? 12 : \ |
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112 | (n) & (1ULL << 11) ? 11 : \ |
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113 | (n) & (1ULL << 10) ? 10 : \ |
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114 | (n) & (1ULL << 9) ? 9 : \ |
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115 | (n) & (1ULL << 8) ? 8 : \ |
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116 | (n) & (1ULL << 7) ? 7 : \ |
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117 | (n) & (1ULL << 6) ? 6 : \ |
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118 | (n) & (1ULL << 5) ? 5 : \ |
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119 | (n) & (1ULL << 4) ? 4 : \ |
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120 | (n) & (1ULL << 3) ? 3 : \ |
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121 | (n) & (1ULL << 2) ? 2 : \ |
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122 | (n) & (1ULL << 1) ? 1 : \ |
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123 | (n) & (1ULL << 0) ? 0 : \ |
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124 | -1) : \ |
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125 | (sizeof(n) <= 4) ? \ |
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126 | fls((u32)(n)) - 1 : flsll((u64)(n)) - 1 \ |
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127 | ) |
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128 | |
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129 | #define order_base_2(x) ilog2(roundup_pow_of_two(x)) |
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130 | |
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131 | #endif /* _LINUX_LOG2_H_ */ |
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