include/ctf/align.h

   1 #ifndef _CTF_ALIGN_H
   2 #define _CTF_ALIGN_H
   3
   4 #include <ctf/compiler.h>
   5
   6 #define ALIGN(x, a)             __ALIGN_MASK(x, (typeof(x))(a) - 1)
   7 #define __ALIGN_MASK(x, mask)   (((x) + (mask)) & ~(mask))
   8 #define PTR_ALIGN(p, a)         ((typeof(p)) ALIGN((unsigned long) (p), a))
   9 #define ALIGN_FLOOR(x, a)       __ALIGN_FLOOR_MASK(x, (typeof(x)) (a) - 1)
  10 #define __ALIGN_FLOOR_MASK(x, mask)     ((x) & ~(mask))
  11 #define PTR_ALIGN_FLOOR(p, a) \
  12                         ((typeof(p)) ALIGN_FLOOR((unsigned long) (p), a))
  13 #define IS_ALIGNED(x, a)        (((x) & ((typeof(x)) (a) - 1)) == 0)
  14
  15 /*
  16  * Align pointer on natural object alignment.
  17  */
  18 #define object_align(obj)       PTR_ALIGN(obj, __alignof__(*(obj)))
  19 #define object_align_floor(obj) PTR_ALIGN_FLOOR(obj, __alignof__(*(obj)))
  20
  21 /**
  22  * offset_align - Calculate the offset needed to align an object on its natural
  23  *                alignment towards higher addresses.
  24  * @align_drift:  object offset from an "alignment"-aligned address.
  25  * @alignment:    natural object alignment. Must be non-zero, power of 2.
  26  *
  27  * Returns the offset that must be added to align towards higher
  28  * addresses.
  29  */
  30 #define offset_align(align_drift, alignment)                                   \
  31         ({                                                                     \
  32                 MAYBE_BUILD_BUG_ON((alignment) == 0                            \
  33                                    || ((alignment) & ((alignment) - 1)));      \
  34                 (((alignment) - (align_drift)) & ((alignment) - 1));           \
  35         })
  36
  37 /**
  38  * offset_align_floor - Calculate the offset needed to align an object
  39  *                      on its natural alignment towards lower addresses.
  40  * @align_drift:  object offset from an "alignment"-aligned address.
  41  * @alignment:    natural object alignment. Must be non-zero, power of 2.
  42  *
  43  * Returns the offset that must be substracted to align towards lower addresses.
  44  */
  45 #define offset_align_floor(align_drift, alignment)                             \
  46         ({                                                                     \
  47                 MAYBE_BUILD_BUG_ON((alignment) == 0                            \
  48                                    || ((alignment) & ((alignment) - 1)));      \
  49                 (((align_drift) - (alignment)) & ((alignment) - 1);            \
  50         })
  51
  52 #endif /* _CTF_ALIGN_H */