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