sys/uvm/uvm_object.h

   1 /*      $NetBSD: uvm_object.h,v 1.25 2008/06/02 16:25:34 ad Exp $       */
   2
   3 /*
   4  *
   5  * Copyright (c) 1997 Charles D. Cranor and Washington University.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  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 the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by Charles D. Cranor and
  19  *      Washington University.
  20  * 4. The name of the author may not be used to endorse or promote products
  21  *    derived from this software without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  *
  34  * from: Id: uvm_object.h,v 1.1.2.2 1998/01/04 22:44:51 chuck Exp
  35  */
  36
  37 #ifndef _UVM_UVM_OBJECT_H_
  38 #define _UVM_UVM_OBJECT_H_
  39
  40 /*
  41  * uvm_object.h
  42  */
  43
  44 #include <sys/rb.h>
  45
  46 /*
  47  * uvm_object: all that is left of mach objects.
  48  */
  49
  50 struct uvm_object {
  51         kmutex_t                vmobjlock;      /* lock on memq */
  52         const struct uvm_pagerops *pgops;       /* pager ops */
  53         struct pglist           memq;           /* pages in this object */
  54         int                     uo_npages;      /* # of pages in memq */
  55         unsigned                uo_refs;        /* reference count */
  56         struct rb_tree          rb_tree;        /* tree of pages */
  57 };
  58
  59 /*
  60  * UVM_OBJ_KERN is a 'special' uo_refs value which indicates that the
  61  * object is a kernel memory object rather than a normal one (kernel
  62  * memory objects don't have reference counts -- they never die).
  63  *
  64  * this value is used to detected kernel object mappings at uvm_unmap()
  65  * time.   normally when an object is unmapped its pages eventaully become
  66  * deactivated and then paged out and/or freed.    this is not useful
  67  * for kernel objects... when a kernel object is unmapped we always want
  68  * to free the resources associated with the mapping.   UVM_OBJ_KERN
  69  * allows us to decide which type of unmapping we want to do.
  70  */
  71 #define UVM_OBJ_KERN            (-2)
  72
  73 #define UVM_OBJ_IS_KERN_OBJECT(uobj)                                    \
  74         ((uobj)->uo_refs == UVM_OBJ_KERN)
  75
  76 #ifdef _KERNEL
  77
  78 extern const struct uvm_pagerops uvm_vnodeops;
  79 extern const struct uvm_pagerops uvm_deviceops;
  80 extern const struct uvm_pagerops ubc_pager;
  81 extern const struct uvm_pagerops aobj_pager;
  82
  83 #define UVM_OBJ_IS_VNODE(uobj)                                          \
  84         ((uobj)->pgops == &uvm_vnodeops)
  85
  86 #define UVM_OBJ_IS_DEVICE(uobj)                                         \
  87         ((uobj)->pgops == &uvm_deviceops)
  88
  89 #define UVM_OBJ_IS_VTEXT(uobj)                                          \
  90         (UVM_OBJ_IS_VNODE(uobj) && uvn_text_p(uobj))
  91
  92 #define UVM_OBJ_IS_CLEAN(uobj)                                          \
  93         (UVM_OBJ_IS_VNODE(uobj) && uvn_clean_p(uobj))
  94
  95 /*
  96  * UVM_OBJ_NEEDS_WRITEFAULT: true if the uobj needs to detect modification.
  97  * (ie. wants to avoid writable user mappings.)
  98  *
  99  * XXX bad name
 100  */
 101
 102 #define UVM_OBJ_NEEDS_WRITEFAULT(uobj)                                  \
 103         (UVM_OBJ_IS_VNODE(uobj) && uvn_needs_writefault_p(uobj))
 104
 105 #define UVM_OBJ_IS_AOBJ(uobj)                                           \
 106         ((uobj)->pgops == &aobj_pager)
 107
 108 extern const struct rb_tree_ops uvm_page_tree_ops;
 109
 110 #define UVM_OBJ_INIT(uobj, ops, refs)                                   \
 111         do {                                                            \
 112                 mutex_init(&(uobj)->vmobjlock, MUTEX_DEFAULT, IPL_NONE);\
 113                 (uobj)->pgops = (ops);                                  \
 114                 TAILQ_INIT(&(uobj)->memq);                              \
 115                 (uobj)->uo_npages = 0;                                  \
 116                 (uobj)->uo_refs = (refs);                               \
 117                 rb_tree_init(&(uobj)->rb_tree, &uvm_page_tree_ops);     \
 118         } while (/* CONSTCOND */ 0)
 119
 120 #ifdef DIAGNOSTIC
 121 #define UVM_OBJ_DESTROY(uobj)                                           \
 122         do {                                                            \
 123                 voff_t _xo = 0;                                         \
 124                 void *_xn;                                              \
 125                 mutex_destroy(&(uobj)->vmobjlock);                      \
 126                 _xn = rb_tree_find_node_geq(&(uobj)->rb_tree, &_xo);    \
 127                 KASSERT(_xn == NULL);                                   \
 128         } while (/* CONSTCOND */ 0)
 129 #else
 130 #define UVM_OBJ_DESTROY(uobj)                                           \
 131         do {                                                            \
 132                 mutex_destroy(&(uobj)->vmobjlock);                      \
 133         } while (/* CONSTCOND */ 0)
 134 #endif  /* DIAGNOSTIC */
 135
 136 #endif /* _KERNEL */
 137
 138 #endif /* _UVM_UVM_OBJECT_H_ */