include/ust/core.h

   1 /* Copyright (C) 2010  Pierre-Marc Fournier
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 2.1 of the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  16  */
  17
  18 #ifndef UST_CORE_H
  19 #define UST_CORE_H
  20
  21 #include <sys/types.h>
  22 #include <ust/config.h>
  23
  24 #define likely(x)       __builtin_expect(!!(x), 1)
  25 #define unlikely(x)     __builtin_expect(!!(x), 0)
  26
  27 #ifndef HAVE_EFFICIENT_UNALIGNED_ACCESS
  28
  29 /*
  30  * Calculate the offset needed to align the type.
  31  * size_of_type must be non-zero.
  32  */
  33 static inline unsigned int ltt_align(size_t align_drift, size_t size_of_type)
  34 {
  35         size_t alignment = min(sizeof(void *), size_of_type);
  36         return (alignment - align_drift) & (alignment - 1);
  37 }
  38 /* Default arch alignment */
  39 #define LTT_ALIGN
  40
  41 static inline int ltt_get_alignment(void)
  42 {
  43         return sizeof(void *);
  44 }
  45
  46 #else /* HAVE_EFFICIENT_UNALIGNED_ACCESS */
  47
  48 static inline unsigned int ltt_align(size_t align_drift,
  49                  size_t size_of_type)
  50 {
  51         return 0;
  52 }
  53
  54 #define LTT_ALIGN __attribute__((packed))
  55
  56 static inline int ltt_get_alignment(void)
  57 {
  58         return 0;
  59 }
  60 #endif /* HAVE_EFFICIENT_UNALIGNED_ACCESS */
  61
  62
  63 /* ARRAYS */
  64
  65 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
  66
  67
  68 /* ALIGNMENT SHORTCUTS */
  69
  70 #include <unistd.h>
  71
  72 #define ALIGN(x,a)              __ALIGN_MASK(x,(typeof(x))(a)-1)
  73 #define __ALIGN_MASK(x,mask)    (((x)+(mask))&~(mask))
  74 #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
  75 #define PAGE_SIZE sysconf(_SC_PAGE_SIZE)
  76 #define PAGE_MASK (~(PAGE_SIZE-1))
  77
  78 /* ERROR OPS */
  79 #define MAX_ERRNO       4095
  80
  81 #define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO)
  82
  83 static inline void *ERR_PTR(long error)
  84 {
  85         return (void *) error;
  86 }
  87
  88 static inline long PTR_ERR(const void *ptr)
  89 {
  90         return (long) ptr;
  91 }
  92
  93 static inline long IS_ERR(const void *ptr)
  94 {
  95         return IS_ERR_VALUE((unsigned long)ptr);
  96 }
  97
  98
  99 /* Min / Max */
 100
 101 #define min_t(type, x, y) ({                    \
 102         type __min1 = (x);                      \
 103         type __min2 = (y);                      \
 104         __min1 < __min2 ? __min1: __min2; })
 105
 106 #define max_t(type, x, y) ({                    \
 107         type __max1 = (x);                      \
 108         type __max2 = (y);                      \
 109         __max1 > __max2 ? __max1: __max2; })
 110
 111
 112 /* MUTEXES */
 113
 114 #include <pthread.h>
 115
 116 #define DEFINE_MUTEX(m) pthread_mutex_t (m) = PTHREAD_MUTEX_INITIALIZER;
 117 #define DECLARE_MUTEX(m) extern pthread_mutex_t (m);
 118
 119 /* MALLOCATION */
 120
 121 #define zmalloc(s) calloc(1, s)
 122
 123 /* MATH */
 124
 125 #include <ust/processor.h>
 126 static inline unsigned int hweight32(unsigned int w)
 127 {
 128         unsigned int res = w - ((w >> 1) & 0x55555555);
 129         res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
 130         res = (res + (res >> 4)) & 0x0F0F0F0F;
 131         res = res + (res >> 8);
 132         return (res + (res >> 16)) & 0x000000FF;
 133 }
 134
 135 static __inline__ int get_count_order(unsigned int count)
 136 {
 137         int order;
 138
 139         order = fls(count) - 1;
 140         if (count & (count - 1))
 141                 order++;
 142         return order;
 143 }
 144
 145 #define _ust_container_of(ptr, type, member) ({                      \
 146         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 147         (type *)( (char *)__mptr - offsetof(type,member) );})
 148
 149 #endif /* UST_CORE_H */