4 #include <linux/list.h>
6 #include <uapi/linux/shm.h>
7 #include <asm/shmparam.h>
9 struct shmid_kernel /* private to the kernel */
11 struct kern_ipc_perm shm_perm;
12 struct file *shm_file;
13 unsigned long shm_nattch;
14 unsigned long shm_segsz;
20 struct user_struct *mlock_user;
23 * The task created the shm object, for
24 * task_lock(shp->shm_creator)
26 struct task_struct *shm_creator;
29 * List by creator. task_lock(->shm_creator) required for read/write.
30 * If list_empty(), then the creator is dead already.
32 struct list_head shm_clist;
33 struct ipc_namespace *ns;
36 /* shm_mode upper byte flags */
37 #define SHM_DEST 01000 /* segment will be destroyed on last detach */
38 #define SHM_LOCKED 02000 /* segment will not be swapped */
39 #define SHM_HUGETLB 04000 /* segment will use huge TLB pages */
40 #define SHM_NORESERVE 010000 /* don't check for reservations */
42 /* Bits [26:31] are reserved */
45 * When SHM_HUGETLB is set bits [26:31] encode the log2 of the huge page size.
46 * This gives us 6 bits, which is enough until someone invents 128 bit address
49 * Assume these are all power of twos.
50 * When 0 use the default page size.
52 #define SHM_HUGE_SHIFT 26
53 #define SHM_HUGE_MASK 0x3f
54 #define SHM_HUGE_2MB (21 << SHM_HUGE_SHIFT)
55 #define SHM_HUGE_1GB (30 << SHM_HUGE_SHIFT)
59 struct list_head shm_clist;
62 long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr,
63 unsigned long shmlba);
64 bool is_file_shm_hugepages(struct file *file);
65 void exit_shm(struct task_struct *task);
66 #define shm_init_task(task) INIT_LIST_HEAD(&(task)->sysvshm.shm_clist)
72 static inline long do_shmat(int shmid, char __user *shmaddr,
73 int shmflg, unsigned long *addr,
78 static inline bool is_file_shm_hugepages(struct file *file)
82 static inline void exit_shm(struct task_struct *task)
85 static inline void shm_init_task(struct task_struct *task)
90 #endif /* _LINUX_SHM_H_ */