1 #ifndef _LINUX_MMAN_H 2 #define _LINUX_MMAN_H 3 4 #include <asm/mman.h> 5 6 #define MREMAP_MAYMOVE 1 7 #define MREMAP_FIXED 2 8 9 #define OVERCOMMIT_GUESS 0 10 #define OVERCOMMIT_ALWAYS 1 11 #define OVERCOMMIT_NEVER 2 12 13 #ifdef __KERNEL__ 14 #include <linux/mm.h> 15 #include <linux/percpu_counter.h> 16 17 #include <linux/atomic.h> 18 19 extern int sysctl_overcommit_memory; 20 extern int sysctl_overcommit_ratio; 21 extern struct percpu_counter vm_committed_as; 22 23 static inline void vm_acct_memory(long pages) 24 { 25 percpu_counter_add(&vm_committed_as, pages); 26 } 27 28 static 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 */ 52 static 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 */ 72 static inline unsigned long 73 calc_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 */ 84 static inline unsigned long 85 calc_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_EXECUTABLE, VM_EXECUTABLE) | 90 _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ); 91 } 92 #endif /* __KERNEL__ */ 93 #endif /* _LINUX_MMAN_H */ 94