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uvm_object.h revision 1.26.18.2 
      1 /*	$NetBSD: uvm_object.h,v 1.26.18.2 2010/10/22 07:22:57 uebayasi 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/rbtree.h>
     45 #include <uvm/uvm_pglist.h>
     46 
     47 /*
     48  * uvm_object: all that is left of mach objects.
     49  */
     50 
     51 struct uvm_object {
     52 	kmutex_t		vmobjlock;	/* lock on memq */
     53 	const struct uvm_pagerops *pgops;	/* pager ops */
     54 	struct pglist		memq;		/* pages in this object */
     55 	int			uo_npages;	/* # of pages in memq */
     56 	unsigned		uo_refs;	/* reference count */
     57 	struct rb_tree		rb_tree;	/* tree of pages */
     58 };
     59 
     60 /*
     61  * UVM_OBJ_KERN is a 'special' uo_refs value which indicates that the
     62  * object is a kernel memory object rather than a normal one (kernel
     63  * memory objects don't have reference counts -- they never die).
     64  *
     65  * this value is used to detected kernel object mappings at uvm_unmap()
     66  * time.   normally when an object is unmapped its pages eventaully become
     67  * deactivated and then paged out and/or freed.    this is not useful
     68  * for kernel objects... when a kernel object is unmapped we always want
     69  * to free the resources associated with the mapping.   UVM_OBJ_KERN
     70  * allows us to decide which type of unmapping we want to do.
     71  */
     72 #define UVM_OBJ_KERN		(-2)
     73 
     74 #define	UVM_OBJ_IS_KERN_OBJECT(uobj)					\
     75 	((uobj)->uo_refs == UVM_OBJ_KERN)
     76 
     77 #ifdef _KERNEL
     78 
     79 extern const struct uvm_pagerops uvm_vnodeops;
     80 extern const struct uvm_pagerops uvm_deviceops;
     81 extern const struct uvm_pagerops ubc_pager;
     82 extern const struct uvm_pagerops aobj_pager;
     83 
     84 #define	UVM_OBJ_IS_VNODE(uobj)						\
     85 	((uobj)->pgops == &uvm_vnodeops)
     86 
     87 #define	UVM_OBJ_IS_DEVICE(uobj)						\
     88 	((uobj)->pgops == &uvm_deviceops)
     89 
     90 #define	UVM_OBJ_IS_VTEXT(uobj)						\
     91 	(UVM_OBJ_IS_VNODE(uobj) && uvn_text_p(uobj))
     92 
     93 #define	UVM_OBJ_IS_CLEAN(uobj)						\
     94 	(UVM_OBJ_IS_VNODE(uobj) && uvn_clean_p(uobj))
     95 
     96 /*
     97  * UVM_OBJ_NEEDS_WRITEFAULT: true if the uobj needs to detect modification.
     98  * (ie. wants to avoid writable user mappings.)
     99  *
    100  * XXX bad name
    101  */
    102 
    103 #define	UVM_OBJ_NEEDS_WRITEFAULT(uobj)					\
    104 	(UVM_OBJ_IS_VNODE(uobj) && uvn_needs_writefault_p(uobj))
    105 
    106 #define	UVM_OBJ_IS_AOBJ(uobj)						\
    107 	((uobj)->pgops == &aobj_pager)
    108 
    109 extern const rb_tree_ops_t uvm_page_tree_ops;
    110 
    111 #define	UVM_OBJ_INIT(uobj, ops, refs)					\
    112 	do {								\
    113 		mutex_init(&(uobj)->vmobjlock, MUTEX_DEFAULT, IPL_NONE);\
    114 		(uobj)->pgops = (ops);					\
    115 		TAILQ_INIT(&(uobj)->memq);				\
    116 		(uobj)->uo_npages = 0;					\
    117 		(uobj)->uo_refs = (refs);				\
    118 		rb_tree_init(&(uobj)->rb_tree, &uvm_page_tree_ops);	\
    119 	} while (/* CONSTCOND */ 0)
    120 
    121 #ifdef DIAGNOSTIC
    122 #define	UVM_OBJ_DESTROY(uobj)						\
    123 	do {								\
    124 		voff_t _xo = 0;						\
    125 		void *_xn;						\
    126 		mutex_destroy(&(uobj)->vmobjlock);			\
    127 		_xn = rb_tree_find_node_geq(&(uobj)->rb_tree, &_xo);	\
    128 		KASSERT(_xn == NULL);					\
    129 	} while (/* CONSTCOND */ 0)
    130 #else
    131 #define	UVM_OBJ_DESTROY(uobj)						\
    132 	do {								\
    133 		mutex_destroy(&(uobj)->vmobjlock);			\
    134 	} while (/* CONSTCOND */ 0)
    135 #endif	/* DIAGNOSTIC */
    136 
    137 #endif /* _KERNEL */
    138 
    139 #endif /* _UVM_UVM_OBJECT_H_ */
    140