drivers/staging/lustre/include/linux/libcfs/libcfs_kernelcomm.h

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  */
  30 /*
  31  * This file is part of Lustre, http://www.lustre.org/
  32  * Lustre is a trademark of Sun Microsystems, Inc.
  33  *
  34  * Author: Nathan Rutman <nathan.rutman@sun.com>
  35  *
  36  * libcfs/include/libcfs/libcfs_kernelcomm.h
  37  *
  38  * Kernel <-> userspace communication routines.
  39  * The definitions below are used in the kernel and userspace.
  40  *
  41  */
  42
  43 #ifndef __LIBCFS_KERNELCOMM_H__
  44 #define __LIBCFS_KERNELCOMM_H__
  45
  46 #ifndef __LIBCFS_LIBCFS_H__
  47 #error Do not #include this file directly. #include <linux/libcfs/libcfs.h> instead
  48 #endif
  49
  50
  51 /* KUC message header.
  52  * All current and future KUC messages should use this header.
  53  * To avoid having to include Lustre headers from libcfs, define this here.
  54  */
  55 struct kuc_hdr {
  56         __u16 kuc_magic;
  57         __u8  kuc_transport;  /* Each new Lustre feature should use a different
  58                                  transport */
  59         __u8  kuc_flags;
  60         __u16 kuc_msgtype;    /* Message type or opcode, transport-specific */
  61         __u16 kuc_msglen;     /* Including header */
  62 } __attribute__((aligned(sizeof(__u64))));
  63
  64 #define KUC_CHANGELOG_MSG_MAXSIZE (sizeof(struct kuc_hdr)+CR_MAXSIZE)
  65
  66 #define KUC_MAGIC  0x191C /*Lustre9etLinC */
  67 #define KUC_FL_BLOCK 0x01   /* Wait for send */
  68
  69 /* kuc_msgtype values are defined in each transport */
  70 enum kuc_transport_type {
  71         KUC_TRANSPORT_GENERIC   = 1,
  72         KUC_TRANSPORT_HSM       = 2,
  73         KUC_TRANSPORT_CHANGELOG = 3,
  74 };
  75
  76 enum kuc_generic_message_type {
  77         KUC_MSG_SHUTDOWN = 1,
  78 };
  79
  80 /* prototype for callback function on kuc groups */
  81 typedef int (*libcfs_kkuc_cb_t)(__u32 data, void *cb_arg);
  82
  83 /* KUC Broadcast Groups. This determines which userspace process hears which
  84  * messages.  Mutliple transports may be used within a group, or multiple
  85  * groups may use the same transport.  Broadcast
  86  * groups need not be used if e.g. a UID is specified instead;
  87  * use group 0 to signify unicast.
  88  */
  89 #define KUC_GRP_HSM        0x02
  90 #define KUC_GRP_MAX        KUC_GRP_HSM
  91
  92 /* Kernel methods */
  93 extern int libcfs_kkuc_msg_put(struct file *fp, void *payload);
  94 extern int libcfs_kkuc_group_put(int group, void *payload);
  95 extern int libcfs_kkuc_group_add(struct file *fp, int uid, int group,
  96                                  __u32 data);
  97 extern int libcfs_kkuc_group_rem(int uid, int group);
  98 extern int libcfs_kkuc_group_foreach(int group, libcfs_kkuc_cb_t cb_func,
  99                                      void *cb_arg);
 100
 101 #define LK_FLG_STOP 0x01
 102
 103 /* kernelcomm control structure, passed from userspace to kernel */
 104 typedef struct lustre_kernelcomm {
 105         __u32 lk_wfd;
 106         __u32 lk_rfd;
 107         __u32 lk_uid;
 108         __u32 lk_group;
 109         __u32 lk_data;
 110         __u32 lk_flags;
 111 } __attribute__((packed)) lustre_kernelcomm;
 112
 113 /* Userspace methods */
 114 extern int libcfs_ukuc_start(lustre_kernelcomm *l, int groups);
 115 extern int libcfs_ukuc_stop(lustre_kernelcomm *l);
 116 extern int libcfs_ukuc_msg_get(lustre_kernelcomm *l, char *buf, int maxsize,
 117                                int transport);
 118
 119 #endif /* __LIBCFS_KERNELCOMM_H__ */