| 1 | #ifndef _LINUX_SHM_H_ |
| 2 | #define _LINUX_SHM_H_ |
| 3 | |
| 4 | #include <asm/page.h> |
| 5 | #include <uapi/linux/shm.h> |
| 6 | |
| 7 | #define SHMALL (SHMMAX/PAGE_SIZE*(SHMMNI/16)) /* max shm system wide (pages) */ |
| 8 | #include <asm/shmparam.h> |
| 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 | }; |
| 25 | |
| 26 | /* shm_mode upper byte flags */ |
| 27 | #define SHM_DEST 01000 /* segment will be destroyed on last detach */ |
| 28 | #define SHM_LOCKED 02000 /* segment will not be swapped */ |
| 29 | #define SHM_HUGETLB 04000 /* segment will use huge TLB pages */ |
| 30 | #define SHM_NORESERVE 010000 /* don't check for reservations */ |
| 31 | |
| 32 | /* Bits [26:31] are reserved */ |
| 33 | |
| 34 | /* |
| 35 | * When SHM_HUGETLB is set bits [26:31] encode the log2 of the huge page size. |
| 36 | * This gives us 6 bits, which is enough until someone invents 128 bit address |
| 37 | * spaces. |
| 38 | * |
| 39 | * Assume these are all power of twos. |
| 40 | * When 0 use the default page size. |
| 41 | */ |
| 42 | #define SHM_HUGE_SHIFT 26 |
| 43 | #define SHM_HUGE_MASK 0x3f |
| 44 | #define SHM_HUGE_2MB (21 << SHM_HUGE_SHIFT) |
| 45 | #define SHM_HUGE_1GB (30 << SHM_HUGE_SHIFT) |
| 46 | |
| 47 | #ifdef CONFIG_SYSVIPC |
| 48 | long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr, |
| 49 | unsigned long shmlba); |
| 50 | extern int is_file_shm_hugepages(struct file *file); |
| 51 | extern void exit_shm(struct task_struct *task); |
| 52 | #else |
| 53 | static inline long do_shmat(int shmid, char __user *shmaddr, |
| 54 | int shmflg, unsigned long *addr, |
| 55 | unsigned long shmlba) |
| 56 | { |
| 57 | return -ENOSYS; |
| 58 | } |
| 59 | static inline int is_file_shm_hugepages(struct file *file) |
| 60 | { |
| 61 | return 0; |
| 62 | } |
| 63 | static inline void exit_shm(struct task_struct *task) |
| 64 | { |
| 65 | } |
| 66 | #endif |
| 67 | |
| 68 | #endif /* _LINUX_SHM_H_ */ |