LXR linux/include/linux/mman.h

   1#ifndef _LINUX_MMAN_H
   2#define _LINUX_MMAN_H
   3
   4#include <linux/mm.h>
   5#include <linux/percpu_counter.h>
   6
   7#include <linux/atomic.h>
   8#include <uapi/linux/mman.h>
   9
  10extern int sysctl_overcommit_memory;
  11extern int sysctl_overcommit_ratio;
  12extern unsigned long sysctl_overcommit_kbytes;
  13extern struct percpu_counter vm_committed_as;
  14
  15#ifdef CONFIG_SMP
  16extern s32 vm_committed_as_batch;
  17#else
  18#define vm_committed_as_batch 0
  19#endif
  20
  21unsigned long vm_memory_committed(void);
  22
  23static inline void vm_acct_memory(long pages)
  24{
  25        __percpu_counter_add(&vm_committed_as, pages, vm_committed_as_batch);
  26}
  27
  28static inline void vm_unacct_memory(long pages)
  29{
  30        vm_acct_memory(-pages);
  31}
  32
  33/*
  34 * Allow architectures to handle additional protection bits
  35 */
  36
  37#ifndef arch_calc_vm_prot_bits
  38#define arch_calc_vm_prot_bits(prot, pkey) 0
  39#endif
  40
  41#ifndef arch_vm_get_page_prot
  42#define arch_vm_get_page_prot(vm_flags) __pgprot(0)
  43#endif
  44
  45#ifndef arch_validate_prot
  46/*
  47 * This is called from mprotect().  PROT_GROWSDOWN and PROT_GROWSUP have
  48 * already been masked out.
  49 *
  50 * Returns true if the prot flags are valid
  51 */
  52static inline int arch_validate_prot(unsigned long prot)
  53{
  54        return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0;
  55}
  56#define arch_validate_prot arch_validate_prot
  57#endif
  58
  59/*
  60 * Optimisation macro.  It is equivalent to:
  61 *      (x & bit1) ? bit2 : 0
  62 * but this version is faster.
  63 * ("bit1" and "bit2" must be single bits)
  64 */
  65#define _calc_vm_trans(x, bit1, bit2) \
  66  ((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \
  67   : ((x) & (bit1)) / ((bit1) / (bit2)))
  68
  69/*
  70 * Combine the mmap "prot" argument into "vm_flags" used internally.
  71 */
  72static inline unsigned long
  73calc_vm_prot_bits(unsigned long prot, unsigned long pkey)
  74{
  75        return _calc_vm_trans(prot, PROT_READ,  VM_READ ) |
  76               _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) |
  77               _calc_vm_trans(prot, PROT_EXEC,  VM_EXEC) |
  78               arch_calc_vm_prot_bits(prot, pkey);
  79}
  80
  81/*
  82 * Combine the mmap "flags" argument into "vm_flags" used internally.
  83 */
  84static inline unsigned long
  85calc_vm_flag_bits(unsigned long flags)
  86{
  87        return _calc_vm_trans(flags, MAP_GROWSDOWN,  VM_GROWSDOWN ) |
  88               _calc_vm_trans(flags, MAP_DENYWRITE,  VM_DENYWRITE ) |
  89               _calc_vm_trans(flags, MAP_LOCKED,     VM_LOCKED    );
  90}
  91
  92unsigned long vm_commit_limit(void);
  93#endif /* _LINUX_MMAN_H */
  94