LXR linux/include/linux/mman.h

   1#ifndef _LINUX_MMAN_H
   2#define _LINUX_MMAN_H
   3
   4#include <asm/mman.h>
   5
   6#define MREMAP_MAYMOVE  1
   7#define MREMAP_FIXED    2
   8
   9#define OVERCOMMIT_GUESS                0
  10#define OVERCOMMIT_ALWAYS               1
  11#define OVERCOMMIT_NEVER                2
  12
  13#ifdef __KERNEL__
  14#include <linux/mm.h>
  15
  16#include <asm/atomic.h>
  17
  18extern int sysctl_overcommit_memory;
  19extern int sysctl_overcommit_ratio;
  20extern atomic_t vm_committed_space;
  21
  22#ifdef CONFIG_SMP
  23extern void vm_acct_memory(long pages);
  24#else
  25static inline void vm_acct_memory(long pages)
  26{
  27        atomic_add(pages, &vm_committed_space);
  28}
  29#endif
  30
  31static inline void vm_unacct_memory(long pages)
  32{
  33        vm_acct_memory(-pages);
  34}
  35
  36/*
  37 * Optimisation macro.  It is equivalent to:
  38 *      (x & bit1) ? bit2 : 0
  39 * but this version is faster.
  40 * ("bit1" and "bit2" must be single bits)
  41 */
  42#define _calc_vm_trans(x, bit1, bit2) \
  43  ((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \
  44   : ((x) & (bit1)) / ((bit1) / (bit2)))
  45
  46/*
  47 * Combine the mmap "prot" argument into "vm_flags" used internally.
  48 */
  49static inline unsigned long
  50calc_vm_prot_bits(unsigned long prot)
  51{
  52        return _calc_vm_trans(prot, PROT_READ,  VM_READ ) |
  53               _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) |
  54               _calc_vm_trans(prot, PROT_EXEC,  VM_EXEC );
  55}
  56
  57/*
  58 * Combine the mmap "flags" argument into "vm_flags" used internally.
  59 */
  60static inline unsigned long
  61calc_vm_flag_bits(unsigned long flags)
  62{
  63        return _calc_vm_trans(flags, MAP_GROWSDOWN,  VM_GROWSDOWN ) |
  64               _calc_vm_trans(flags, MAP_DENYWRITE,  VM_DENYWRITE ) |
  65               _calc_vm_trans(flags, MAP_EXECUTABLE, VM_EXECUTABLE) |
  66               _calc_vm_trans(flags, MAP_LOCKED,     VM_LOCKED    );
  67}
  68#endif /* __KERNEL__ */
  69#endif /* _LINUX_MMAN_H */
  70