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) 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)
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);
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