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
  23 #define likely(x)       __builtin_expect(!!(x), 1)
  24 #define unlikely(x)     __builtin_expect(!!(x), 0)
  25
  26 #if defined(CONFIG_LTT) && defined(CONFIG_LTT_ALIGNMENT)
  27
  28 /*
  29  * Calculate the offset needed to align the type.
  30  * size_of_type must be non-zero.
  31  */
  32 static inline unsigned int ltt_align(size_t align_drift, size_t size_of_type)
  33 {
  34         size_t alignment = min(sizeof(void *), size_of_type);
  35         return (alignment - align_drift) & (alignment - 1);
  36 }
  37 /* Default arch alignment */
  38 #define LTT_ALIGN
  39
  40 static inline int ltt_get_alignment(void)
  41 {
  42         return sizeof(void *);
  43 }
  44
  45 #else
  46
  47 static inline unsigned int ltt_align(size_t align_drift,
  48                  size_t size_of_type)
  49 {
  50         return 0;
  51 }
  52
  53 #define LTT_ALIGN __attribute__((packed))
  54
  55 static inline int ltt_get_alignment(void)
  56 {
  57         return 0;
  58 }
  59 #endif /* defined(CONFIG_LTT) && defined(CONFIG_LTT_ALIGNMENT) */
  60
  61
  62 /* ARRAYS */
  63
  64 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
  65
  66
  67 /* ALIGNMENT SHORTCUTS */
  68
  69 #include <unistd.h>
  70
  71 #define ALIGN(x,a)              __ALIGN_MASK(x,(typeof(x))(a)-1)
  72 #define __ALIGN_MASK(x,mask)    (((x)+(mask))&~(mask))
  73 #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
  74 #define PAGE_SIZE sysconf(_SC_PAGE_SIZE)
  75 #define PAGE_MASK (~(PAGE_SIZE-1))
  76
  77 /* ERROR OPS */
  78 #define MAX_ERRNO       4095
  79
  80 #define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO)
  81
  82 static inline void *ERR_PTR(long error)
  83 {
  84         return (void *) error;
  85 }
  86
  87 static inline long PTR_ERR(const void *ptr)
  88 {
  89         return (long) ptr;
  90 }
  91
  92 static inline long IS_ERR(const void *ptr)
  93 {
  94         return IS_ERR_VALUE((unsigned long)ptr);
  95 }
  96
  97
  98 /* Min / Max */
  99
 100 #define min_t(type, x, y) ({                    \
 101         type __min1 = (x);                      \
 102         type __min2 = (y);                      \
 103         __min1 < __min2 ? __min1: __min2; })
 104
 105 #define max_t(type, x, y) ({                    \
 106         type __max1 = (x);                      \
 107         type __max2 = (y);                      \
 108         __max1 > __max2 ? __max1: __max2; })
 109
 110
 111 /* MUTEXES */
 112
 113 #include <pthread.h>
 114
 115 #define DEFINE_MUTEX(m) pthread_mutex_t (m) = PTHREAD_MUTEX_INITIALIZER;
 116 #define DECLARE_MUTEX(m) extern pthread_mutex_t (m);
 117
 118 /* MALLOCATION */
 119
 120 #define zmalloc(s) calloc(1, s)
 121
 122 /* MATH */
 123
 124 #include <ust/processor.h>
 125 static inline unsigned int hweight32(unsigned int w)
 126 {
 127         unsigned int res = w - ((w >> 1) & 0x55555555);
 128         res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
 129         res = (res + (res >> 4)) & 0x0F0F0F0F;
 130         res = res + (res >> 8);
 131         return (res + (res >> 16)) & 0x000000FF;
 132 }
 133
 134 static __inline__ int get_count_order(unsigned int count)
 135 {
 136         int order;
 137
 138         order = fls(count) - 1;
 139         if (count & (count - 1))
 140                 order++;
 141         return order;
 142 }
 143
 144 #define _ust_container_of(ptr, type, member) ({                      \
 145         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 146         (type *)( (char *)__mptr - offsetof(type,member) );})
 147
 148 #endif /* UST_CORE_H */