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_long_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_long_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 * Allow architectures to handle additional protection bits
  38 */
  39
  40#ifndef arch_calc_vm_prot_bits
  41#define arch_calc_vm_prot_bits(prot) 0
  42#endif
  43
  44#ifndef arch_vm_get_page_prot
  45#define arch_vm_get_page_prot(vm_flags) __pgprot(0)
  46#endif
  47
  48#ifndef arch_validate_prot
  49/*
  50 * This is called from mprotect().  PROT_GROWSDOWN and PROT_GROWSUP have
  51 * already been masked out.
  52 *
  53 * Returns true if the prot flags are valid
  54 */
  55static inline int arch_validate_prot(unsigned long prot)
  56{
  57        return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0;
  58}
  59#define arch_validate_prot arch_validate_prot
  60#endif
  61
  62/*
  63 * Optimisation macro.  It is equivalent to:
  64 *      (x & bit1) ? bit2 : 0
  65 * but this version is faster.
  66 * ("bit1" and "bit2" must be single bits)
  67 */
  68#define _calc_vm_trans(x, bit1, bit2) \
  69  ((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \
  70   : ((x) & (bit1)) / ((bit1) / (bit2)))
  71
  72/*
  73 * Combine the mmap "prot" argument into "vm_flags" used internally.
  74 */
  75static inline unsigned long
  76calc_vm_prot_bits(unsigned long prot)
  77{
  78        return _calc_vm_trans(prot, PROT_READ,  VM_READ ) |
  79               _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) |
  80               _calc_vm_trans(prot, PROT_EXEC,  VM_EXEC) |
  81               arch_calc_vm_prot_bits(prot);
  82}
  83
  84/*
  85 * Combine the mmap "flags" argument into "vm_flags" used internally.
  86 */
  87static inline unsigned long
  88calc_vm_flag_bits(unsigned long flags)
  89{
  90        return _calc_vm_trans(flags, MAP_GROWSDOWN,  VM_GROWSDOWN ) |
  91               _calc_vm_trans(flags, MAP_DENYWRITE,  VM_DENYWRITE ) |
  92               _calc_vm_trans(flags, MAP_EXECUTABLE, VM_EXECUTABLE) |
  93               _calc_vm_trans(flags, MAP_LOCKED,     VM_LOCKED    );
  94}
  95#endif /* __KERNEL__ */
  96#endif /* _LINUX_MMAN_H */
  97