sys/sys/sysref.h

   1 /*
   2  * Copyright (c) 2007 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/sys/sys/sysref.h,v 1.4 2007/05/29 17:01:02 dillon Exp $
  35  */
  36 /*
  37  * System resource registration, reference counter, and allocation
  38  * management subsystem.
  39  *
  40  * All major system resources use this structure and API to associate
  41  * a machine-unique sysid with a major system resource structure, to
  42  * reference count that structure, to register the structure and provide
  43  * a dictionary lookup feature for remote access.
  44  *
  45  * System resources are backed by the objcache.
  46  */
  47
  48 #ifndef _SYS_SYSREF_H_
  49 #define _SYS_SYSREF_H_
  50
  51 #ifndef _SYS_SYSID_H_
  52 #include <sys/sysid.h>
  53 #endif
  54 #ifndef _SYS_TREE_H_
  55 #include <sys/tree.h>
  56 #endif
  57 #ifndef _SYS_OBJCACHE_H_
  58 #include <sys/objcache.h>
  59 #endif
  60 #ifndef _SYS_MALLOC_H_
  61 #include <sys/malloc.h>
  62 #endif
  63
  64 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
  65
  66 /*
  67  * Register a resource structure type.  Note that the destroy function
  68  * will be called on 1->0 transitions (really 1->-0x40000000 transitions),
  69  * and the free function
  70  * but the free function can be called via an IPI, without the BGL, and
  71  * must be carefully coded if it does anything more complex then objcache_put
  72  */
  73 typedef void (*sysref_terminate_func_t)(void *);
  74 typedef void (*sysref_lock_func_t)(void *);
  75 typedef void (*sysref_unlock_func_t)(void *);
  76
  77 struct sysref_class {
  78         const char *name;               /* name of the system resource */
  79         malloc_type_t mtype;            /* malloc backing store */
  80         int     proto;                  /* RPC protocol id */
  81         int     offset;                 /* offset of sysref in resource */
  82         int     objsize;                /* size of the resource structure */
  83         int     mag_capacity;           /* magazine capacity init (def 64) */
  84         int     flags;
  85         struct objcache *oc;            /* object cache */
  86         objcache_ctor_fn *ctor;         /* objcache ctor chaining */
  87         objcache_dtor_fn *dtor;         /* objcache dtor chaining */
  88         struct sysref_ops {
  89                 sysref_terminate_func_t terminate;
  90                 sysref_lock_func_t lock;
  91                 sysref_unlock_func_t unlock;
  92         } ops;
  93 };
  94
  95 #define SRC_MANAGEDINIT 0x0001          /* do not auto-zero the resource */
  96
  97 /*
  98  * sysref - embedded in resource structures.
  99  *
 100  * NOTE: The cpuid determining which cpu's RB tree the sysref is
 101  * associated with is integrated into the sysref.
 102  *
 103  * NOTE: A resource can be in varying states of construction or
 104  * deconstruction, denoted by having a negative refcnt.  To keep
 105  * performance nominal we reuse sysids that are NOT looked up via
 106  * syslink (meaning we don't have to adjust their location in the
 107  * RB tree).  The objcache is used to cache the RB tree linkage.
 108  */
 109 struct sysref {
 110         RB_ENTRY(sysref) rbnode;        /* per-cpu red-black tree node */
 111         sysid_t sysid;                  /* machine-wide unique sysid */
 112         int     refcnt;                 /* normal reference count */
 113         int     flags;
 114         struct sysref_class *srclass;   /* type of resource and API */
 115 };
 116
 117 #define SRF_SYSIDUSED   0x0001          /* sysid was used for access */
 118 #define SRF_ALLOCATED   0x0002          /* sysref_alloc used to allocate */
 119
 120 RB_HEAD(sysref_rb_tree, sysref);
 121 RB_PROTOTYPE2(sysref_rb_tree, sysref, rbnode, rb_sysref_compare, sysid_t);
 122
 123 #endif
 124
 125 /*
 126  * Protocol numbers
 127  */
 128 #define SYSREF_PROTO_VMSPACE    0x0020
 129 #define SYSREF_PROTO_VMOBJECT   0x0021
 130 #define SYSREF_PROTO_VNODE      0x0022
 131 #define SYSREF_PROTO_PROCESS    0x0023
 132 #define SYSREF_PROTO_LWP        0x0024
 133 #define SYSREF_PROTO_FD         0x0025
 134 #define SYSREF_PROTO_FP         0x0026
 135 #define SYSREF_PROTO_SOCKET     0x0027
 136 #define SYSREF_PROTO_NCP        0x0028
 137 #define SYSREF_PROTO_BUF        0x0029
 138 #define SYSREF_PROTO_FSMOUNT    0x002A
 139 #define SYSREF_PROTO_DEV        0x002B
 140
 141 #ifdef _KERNEL
 142
 143 sysid_t allocsysid(void);
 144
 145 #endif
 146
 147 #endif