1 #ifndef _LINUX_SHM_H_ 2 #define _LINUX_SHM_H_ 3 4 #include <linux/list.h> 5 #include <asm/page.h> 6 #include <uapi/linux/shm.h> 7 #include <asm/shmparam.h> 8 9 struct shmid_kernel /* private to the kernel */ 10 { 11 struct kern_ipc_perm shm_perm; 12 struct file *shm_file; 13 unsigned long shm_nattch; 14 unsigned long shm_segsz; 15 time_t shm_atim; 16 time_t shm_dtim; 17 time_t shm_ctim; 18 pid_t shm_cprid; 19 pid_t shm_lprid; 20 struct user_struct *mlock_user; 21 22 /* The task created the shm object. NULL if the task is dead. */ 23 struct task_struct *shm_creator; 24 struct list_head shm_clist; /* list by creator */ 25 }; 26 27 /* shm_mode upper byte flags */ 28 #define SHM_DEST 01000 /* segment will be destroyed on last detach */ 29 #define SHM_LOCKED 02000 /* segment will not be swapped */ 30 #define SHM_HUGETLB 04000 /* segment will use huge TLB pages */ 31 #define SHM_NORESERVE 010000 /* don't check for reservations */ 32 33 /* Bits [26:31] are reserved */ 34 35 /* 36 * When SHM_HUGETLB is set bits [26:31] encode the log2 of the huge page size. 37 * This gives us 6 bits, which is enough until someone invents 128 bit address 38 * spaces. 39 * 40 * Assume these are all power of twos. 41 * When 0 use the default page size. 42 */ 43 #define SHM_HUGE_SHIFT 26 44 #define SHM_HUGE_MASK 0x3f 45 #define SHM_HUGE_2MB (21 << SHM_HUGE_SHIFT) 46 #define SHM_HUGE_1GB (30 << SHM_HUGE_SHIFT) 47 48 #ifdef CONFIG_SYSVIPC 49 struct sysv_shm { 50 struct list_head shm_clist; 51 }; 52 53 long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr, 54 unsigned long shmlba); 55 bool is_file_shm_hugepages(struct file *file); 56 void exit_shm(struct task_struct *task); 57 #define shm_init_task(task) INIT_LIST_HEAD(&(task)->sysvshm.shm_clist) 58 #else 59 struct sysv_shm { 60 /* empty */ 61 }; 62 63 static inline long do_shmat(int shmid, char __user *shmaddr, 64 int shmflg, unsigned long *addr, 65 unsigned long shmlba) 66 { 67 return -ENOSYS; 68 } 69 static inline bool is_file_shm_hugepages(struct file *file) 70 { 71 return false; 72 } 73 static inline void exit_shm(struct task_struct *task) 74 { 75 } 76 static inline void shm_init_task(struct task_struct *task) 77 { 78 } 79 #endif 80 81 #endif /* _LINUX_SHM_H_ */ 82