/* * linux/ipc/util.h * Copyright (C) 1999 Christoph Rohland * * ipc helper functions (c) 1999 Manfred Spraul <manfreds@colorfullife.com> */ #ifndef _IPC_UTIL_H#define _IPC_UTIL_H #define USHRT_MAX 0xffff#define SEQ_MULTIPLIER	(IPCMNI) void sem_init (void);void msg_init (void);void shm_init (void); struct ipc_id_ary {	int size;	struct kern_ipc_perm *p[0];}; struct ipc_ids {	int in_use;	int max_id;	unsigned short seq;	unsigned short seq_max;	struct semaphore sem;		struct ipc_id_ary nullentry;	struct ipc_id_ary* entries;}; void __init ipc_init_ids(struct ipc_ids* ids, int size); /* must be called with ids->sem acquired.*/int ipc_findkey(struct ipc_ids* ids, key_t key);int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size); /* must be called with both locks acquired. */struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id); int ipcperms (struct kern_ipc_perm *ipcp, short flg); /* for rare, potentially huge allocations. * both function can sleep */void* ipc_alloc(int size);void ipc_free(void* ptr, int size); /* * For allocation that need to be freed by RCU. * Objects are reference counted, they start with reference count 1. * getref increases the refcount, the putref call that reduces the recount * to 0 schedules the rcu destruction. Caller must guarantee locking. */void* ipc_rcu_alloc(int size);void ipc_rcu_getref(void *ptr);void ipc_rcu_putref(void *ptr); struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id);struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id);void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp);void ipc_unlock(struct kern_ipc_perm* perm);int ipc_buildid(struct ipc_ids* ids, int id, int seq);int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid); void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); #if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__)  /* On IA-64, we always use the "64-bit version" of the IPC structures.  */ # define ipc_parse_version(cmd)	IPC_64#elseint ipc_parse_version (int *cmd);#endif extern void free_msg(struct msg_msg *msg);extern struct msg_msg *load_msg(const void __user *src, int len);extern int store_msg(void __user *dest, struct msg_msg *msg, int len); #endif