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