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 16 #include <asm/atomic.h> 17 18 extern int sysctl_overcommit_memory; 19 extern int sysctl_overcommit_ratio; 20 extern atomic_long_t vm_committed_space; 21 22 #ifdef CONFIG_SMP 23 extern void vm_acct_memory(long pages); 24 #else 25 static inline void vm_acct_memory(long pages) 26 { 27 atomic_long_add(pages, &vm_committed_space); 28 } 29 #endif 30 31 static inline void vm_unacct_memory(long pages) 32 { 33 vm_acct_memory(-pages); 34 } 35 36 /* 37 * Allow architectures to handle additional protection bits 38 */ 39 40 #ifndef arch_calc_vm_prot_bits 41 #define arch_calc_vm_prot_bits(prot) 0 42 #endif 43 44 #ifndef arch_vm_get_page_prot 45 #define arch_vm_get_page_prot(vm_flags) __pgprot(0) 46 #endif 47 48 #ifndef arch_validate_prot 49 /* 50 * This is called from mprotect(). PROT_GROWSDOWN and PROT_GROWSUP have 51 * already been masked out. 52 * 53 * Returns true if the prot flags are valid 54 */ 55 static inline int arch_validate_prot(unsigned long prot) 56 { 57 return (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM)) == 0; 58 } 59 #define arch_validate_prot arch_validate_prot 60 #endif 61 62 /* 63 * Optimisation macro. It is equivalent to: 64 * (x & bit1) ? bit2 : 0 65 * but this version is faster. 66 * ("bit1" and "bit2" must be single bits) 67 */ 68 #define _calc_vm_trans(x, bit1, bit2) \ 69 ((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \ 70 : ((x) & (bit1)) / ((bit1) / (bit2))) 71 72 /* 73 * Combine the mmap "prot" argument into "vm_flags" used internally. 74 */ 75 static inline unsigned long 76 calc_vm_prot_bits(unsigned long prot) 77 { 78 return _calc_vm_trans(prot, PROT_READ, VM_READ ) | 79 _calc_vm_trans(prot, PROT_WRITE, VM_WRITE) | 80 _calc_vm_trans(prot, PROT_EXEC, VM_EXEC) | 81 arch_calc_vm_prot_bits(prot); 82 } 83 84 /* 85 * Combine the mmap "flags" argument into "vm_flags" used internally. 86 */ 87 static inline unsigned long 88 calc_vm_flag_bits(unsigned long flags) 89 { 90 return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) | 91 _calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) | 92 _calc_vm_trans(flags, MAP_EXECUTABLE, VM_EXECUTABLE) | 93 _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ); 94 } 95 #endif /* __KERNEL__ */ 96 #endif /* _LINUX_MMAN_H */ 97