LXR linux-bk/ipc/util.h

   1/*
   2 * linux/ipc/util.h
   3 * Copyright (C) 1999 Christoph Rohland
   4 *
   5 * ipc helper functions (c) 1999 Manfred Spraul <manfreds@colorfullife.com>
   6 */
   7
   8#ifndef _IPC_UTIL_H
   9#define _IPC_UTIL_H
  10
  11#define USHRT_MAX 0xffff
  12#define SEQ_MULTIPLIER  (IPCMNI)
  13
  14void sem_init (void);
  15void msg_init (void);
  16void shm_init (void);
  17
  18struct ipc_id_ary {
  19        int size;
  20        struct kern_ipc_perm *p[0];
  21};
  22
  23struct ipc_ids {
  24        int in_use;
  25        int max_id;
  26        unsigned short seq;
  27        unsigned short seq_max;
  28        struct semaphore sem;   
  29        struct ipc_id_ary nullentry;
  30        struct ipc_id_ary* entries;
  31};
  32
  33void __init ipc_init_ids(struct ipc_ids* ids, int size);
  34
  35/* must be called with ids->sem acquired.*/
  36int ipc_findkey(struct ipc_ids* ids, key_t key);
  37int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size);
  38
  39/* must be called with both locks acquired. */
  40struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id);
  41
  42int ipcperms (struct kern_ipc_perm *ipcp, short flg);
  43
  44/* for rare, potentially huge allocations.
  45 * both function can sleep
  46 */
  47void* ipc_alloc(int size);
  48void ipc_free(void* ptr, int size);
  49
  50/*
  51 * For allocation that need to be freed by RCU.
  52 * Objects are reference counted, they start with reference count 1.
  53 * getref increases the refcount, the putref call that reduces the recount
  54 * to 0 schedules the rcu destruction. Caller must guarantee locking.
  55 */
  56void* ipc_rcu_alloc(int size);
  57void ipc_rcu_getref(void *ptr);
  58void ipc_rcu_putref(void *ptr);
  59
  60struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id);
  61struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id);
  62void ipc_lock_by_ptr(struct kern_ipc_perm *ipcp);
  63void ipc_unlock(struct kern_ipc_perm* perm);
  64int ipc_buildid(struct ipc_ids* ids, int id, int seq);
  65int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid);
  66
  67void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
  68void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
  69
  70#if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__)
  71  /* On IA-64, we always use the "64-bit version" of the IPC structures.  */ 
  72# define ipc_parse_version(cmd) IPC_64
  73#else
  74int ipc_parse_version (int *cmd);
  75#endif
  76
  77extern void free_msg(struct msg_msg *msg);
  78extern struct msg_msg *load_msg(const void __user *src, int len);
  79extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
  80
  81#endif
  82