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 /* ARRAYS */
  28
  29 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
  30
  31
  32 /* ALIGNMENT SHORTCUTS */
  33
  34 #include <unistd.h>
  35
  36 #define ALIGN(x,a)              __ALIGN_MASK(x,(typeof(x))(a)-1)
  37 #define __ALIGN_MASK(x,mask)    (((x)+(mask))&~(mask))
  38 #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
  39 #define PAGE_SIZE sysconf(_SC_PAGE_SIZE)
  40 #define PAGE_MASK (~(PAGE_SIZE-1))
  41
  42 /* ERROR OPS */
  43 #define MAX_ERRNO       4095
  44
  45 #define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO)
  46
  47 static inline void *ERR_PTR(long error)
  48 {
  49         return (void *) error;
  50 }
  51
  52 static inline long PTR_ERR(const void *ptr)
  53 {
  54         return (long) ptr;
  55 }
  56
  57 static inline long IS_ERR(const void *ptr)
  58 {
  59         return IS_ERR_VALUE((unsigned long)ptr);
  60 }
  61
  62
  63 /* Min / Max */
  64
  65 #define min_t(type, x, y) ({                    \
  66         type __min1 = (x);                      \
  67         type __min2 = (y);                      \
  68         __min1 < __min2 ? __min1: __min2; })
  69
  70 #define max_t(type, x, y) ({                    \
  71         type __max1 = (x);                      \
  72         type __max2 = (y);                      \
  73         __max1 > __max2 ? __max1: __max2; })
  74
  75
  76 /* MUTEXES */
  77
  78 #include <pthread.h>
  79
  80 #define DEFINE_MUTEX(m) pthread_mutex_t (m) = PTHREAD_MUTEX_INITIALIZER;
  81 #define DECLARE_MUTEX(m) extern pthread_mutex_t (m);
  82
  83 /* MALLOCATION */
  84
  85 #define zmalloc(s) calloc(1, s)
  86
  87 /* MATH */
  88
  89 #include <ust/processor.h>
  90 static inline unsigned int hweight32(unsigned int w)
  91 {
  92         unsigned int res = w - ((w >> 1) & 0x55555555);
  93         res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
  94         res = (res + (res >> 4)) & 0x0F0F0F0F;
  95         res = res + (res >> 8);
  96         return (res + (res >> 16)) & 0x000000FF;
  97 }
  98
  99 static __inline__ int get_count_order(unsigned int count)
 100 {
 101         int order;
 102
 103         order = fls(count) - 1;
 104         if (count & (count - 1))
 105                 order++;
 106         return order;
 107 }
 108
 109 #define _ust_container_of(ptr, type, member) ({                      \
 110         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 111         (type *)( (char *)__mptr - offsetof(type,member) );})
 112
 113 #endif /* UST_CORE_H */