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 extern int sysctl_overcommit_memory; 12 extern int sysctl_overcommit_ratio; 13 extern unsigned long sysctl_overcommit_kbytes; 14 extern struct percpu_counter vm_committed_as; 15 16 #ifdef CONFIG_SMP 17 extern s32 vm_committed_as_batch; 18 #else 19 #define vm_committed_as_batch 0 20 #endif 21 22 unsigned long vm_memory_committed(void); 23 24 static inline void vm_acct_memory(long pages) 25 { 26 percpu_counter_add_batch(&vm_committed_as, pages, vm_committed_as_batch); 27 } 28 29 static inline void vm_unacct_memory(long pages) 30 { 31 vm_acct_memory(-pages); 32 } 33 34 /* 35 * Allow architectures to handle additional protection bits 36 */ 37 38 #ifndef arch_calc_vm_prot_bits 39 #define arch_calc_vm_prot_bits(prot, pkey) 0 40 #endif 41 42 #ifndef arch_vm_get_page_prot 43 #define arch_vm_get_page_prot(vm_flags) __pgprot(0) 44 #endif 45 46 #ifndef arch_validate_prot 47 /* 48 * This is called from mprotect(). PROT_GROWSDOWN and PROT_GROWSUP have 49 * already been masked out. 50 * 51 * Returns true if the prot flags are valid 52 */ 53 static inline bool arch_validate_prot(unsigned long prot) 54 { 55 return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0; 56 } 57 #define arch_validate_prot arch_validate_prot 58 #endif 59 60 /* 61 * Optimisation macro. It is equivalent to: 62 * (x & bit1) ? bit2 : 0 63 * but this version is faster. 64 * ("bit1" and "bit2" must be single bits) 65 */ 66 #define _calc_vm_trans(x, bit1, bit2) \ 67 ((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \ 68 : ((x) & (bit1)) / ((bit1) / (bit2))) 69 70 /* 71 * Combine the mmap "prot" argument into "vm_flags" used internally. 72 */ 73 static inline unsigned long 74 calc_vm_prot_bits(unsigned long prot, unsigned long pkey) 75 { 76 return _calc_vm_trans(prot, PROT_READ, VM_READ ) | 77 _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) | 78 _calc_vm_trans(prot, PROT_EXEC, VM_EXEC) | 79 arch_calc_vm_prot_bits(prot, pkey); 80 } 81 82 /* 83 * Combine the mmap "flags" argument into "vm_flags" used internally. 84 */ 85 static inline unsigned long 86 calc_vm_flag_bits(unsigned long flags) 87 { 88 return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) | 89 _calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) | 90 _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ); 91 } 92 93 unsigned long vm_commit_limit(void); 94 #endif /* _LINUX_MMAN_H */ 95