Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_MMAN_H
3#define _LINUX_MMAN_H
4
5#include <linux/mm.h>
6#include <linux/percpu_counter.h>
7
8#include <linux/atomic.h>
9#include <uapi/linux/mman.h>
10
11/*
12 * Arrange for legacy / undefined architecture specific flags to be
13 * ignored by mmap handling code.
14 */
15#ifndef MAP_32BIT
16#define MAP_32BIT 0
17#endif
18#ifndef MAP_HUGE_2MB
19#define MAP_HUGE_2MB 0
20#endif
21#ifndef MAP_HUGE_1GB
22#define MAP_HUGE_1GB 0
23#endif
24#ifndef MAP_UNINITIALIZED
25#define MAP_UNINITIALIZED 0
26#endif
27#ifndef MAP_SYNC
28#define MAP_SYNC 0
29#endif
30
31/*
32 * The historical set of flags that all mmap implementations implicitly
33 * support when a ->mmap_validate() op is not provided in file_operations.
34 */
35#define LEGACY_MAP_MASK (MAP_SHARED \
36 | MAP_PRIVATE \
37 | MAP_FIXED \
38 | MAP_ANONYMOUS \
39 | MAP_DENYWRITE \
40 | MAP_EXECUTABLE \
41 | MAP_UNINITIALIZED \
42 | MAP_GROWSDOWN \
43 | MAP_LOCKED \
44 | MAP_NORESERVE \
45 | MAP_POPULATE \
46 | MAP_NONBLOCK \
47 | MAP_STACK \
48 | MAP_HUGETLB \
49 | MAP_32BIT \
50 | MAP_HUGE_2MB \
51 | MAP_HUGE_1GB)
52
53extern int sysctl_overcommit_memory;
54extern int sysctl_overcommit_ratio;
55extern unsigned long sysctl_overcommit_kbytes;
56extern struct percpu_counter vm_committed_as;
57
58#ifdef CONFIG_SMP
59extern s32 vm_committed_as_batch;
60extern void mm_compute_batch(int overcommit_policy);
61#else
62#define vm_committed_as_batch 0
63static inline void mm_compute_batch(int overcommit_policy)
64{
65}
66#endif
67
68unsigned long vm_memory_committed(void);
69
70static inline void vm_acct_memory(long pages)
71{
72 percpu_counter_add_batch(&vm_committed_as, pages, vm_committed_as_batch);
73}
74
75static inline void vm_unacct_memory(long pages)
76{
77 vm_acct_memory(-pages);
78}
79
80/*
81 * Allow architectures to handle additional protection bits
82 */
83
84#ifndef arch_calc_vm_prot_bits
85#define arch_calc_vm_prot_bits(prot, pkey) 0
86#endif
87
88#ifndef arch_vm_get_page_prot
89#define arch_vm_get_page_prot(vm_flags) __pgprot(0)
90#endif
91
92#ifndef arch_validate_prot
93/*
94 * This is called from mprotect(). PROT_GROWSDOWN and PROT_GROWSUP have
95 * already been masked out.
96 *
97 * Returns true if the prot flags are valid
98 */
99static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
100{
101 return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0;
102}
103#define arch_validate_prot arch_validate_prot
104#endif
105
106/*
107 * Optimisation macro. It is equivalent to:
108 * (x & bit1) ? bit2 : 0
109 * but this version is faster.
110 * ("bit1" and "bit2" must be single bits)
111 */
112#define _calc_vm_trans(x, bit1, bit2) \
113 ((!(bit1) || !(bit2)) ? 0 : \
114 ((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \
115 : ((x) & (bit1)) / ((bit1) / (bit2))))
116
117/*
118 * Combine the mmap "prot" argument into "vm_flags" used internally.
119 */
120static inline unsigned long
121calc_vm_prot_bits(unsigned long prot, unsigned long pkey)
122{
123 return _calc_vm_trans(prot, PROT_READ, VM_READ ) |
124 _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) |
125 _calc_vm_trans(prot, PROT_EXEC, VM_EXEC) |
126 arch_calc_vm_prot_bits(prot, pkey);
127}
128
129/*
130 * Combine the mmap "flags" argument into "vm_flags" used internally.
131 */
132static inline unsigned long
133calc_vm_flag_bits(unsigned long flags)
134{
135 return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) |
136 _calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) |
137 _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) |
138 _calc_vm_trans(flags, MAP_SYNC, VM_SYNC );
139}
140
141unsigned long vm_commit_limit(void);
142#endif /* _LINUX_MMAN_H */