1 #ifndef _LINUX_SHM_H_ 2 #define _LINUX_SHM_H_ 3 4 #include <asm/page.h> 5 #include <uapi/linux/shm.h> 6 #include <asm/shmparam.h> 7 8 struct shmid_kernel /* private to the kernel */ 9 { 10 struct kern_ipc_perm shm_perm; 11 struct file *shm_file; 12 unsigned long shm_nattch; 13 unsigned long shm_segsz; 14 time_t shm_atim; 15 time_t shm_dtim; 16 time_t shm_ctim; 17 pid_t shm_cprid; 18 pid_t shm_lprid; 19 struct user_struct *mlock_user; 20 21 /* The task created the shm object. NULL if the task is dead. */ 22 struct task_struct *shm_creator; 23 }; 24 25 /* shm_mode upper byte flags */ 26 #define SHM_DEST 01000 /* segment will be destroyed on last detach */ 27 #define SHM_LOCKED 02000 /* segment will not be swapped */ 28 #define SHM_HUGETLB 04000 /* segment will use huge TLB pages */ 29 #define SHM_NORESERVE 010000 /* don't check for reservations */ 30 31 /* Bits [26:31] are reserved */ 32 33 /* 34 * When SHM_HUGETLB is set bits [26:31] encode the log2 of the huge page size. 35 * This gives us 6 bits, which is enough until someone invents 128 bit address 36 * spaces. 37 * 38 * Assume these are all power of twos. 39 * When 0 use the default page size. 40 */ 41 #define SHM_HUGE_SHIFT 26 42 #define SHM_HUGE_MASK 0x3f 43 #define SHM_HUGE_2MB (21 << SHM_HUGE_SHIFT) 44 #define SHM_HUGE_1GB (30 << SHM_HUGE_SHIFT) 45 46 #ifdef CONFIG_SYSVIPC 47 long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr, 48 unsigned long shmlba); 49 extern int is_file_shm_hugepages(struct file *file); 50 extern void exit_shm(struct task_struct *task); 51 #else 52 static inline long do_shmat(int shmid, char __user *shmaddr, 53 int shmflg, unsigned long *addr, 54 unsigned long shmlba) 55 { 56 return -ENOSYS; 57 } 58 static inline int is_file_shm_hugepages(struct file *file) 59 { 60 return 0; 61 } 62 static inline void exit_shm(struct task_struct *task) 63 { 64 } 65 #endif 66 67 #endif /* _LINUX_SHM_H_ */ 68