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uvm_object.h revision 1.22 
      1 /*	$NetBSD: uvm_object.h,v 1.22 2006/10/12 10:14:20 yamt 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 /*
     45  * uvm_object: all that is left of mach objects.
     46  */
     47 
     48 struct uvm_object {
     49 	struct simplelock	vmobjlock;	/* lock on memq */
     50 	struct uvm_pagerops	*pgops;		/* pager ops */
     51 	struct pglist		memq;		/* pages in this object */
     52 	int			uo_npages;	/* # of pages in memq */
     53 	int			uo_refs;	/* reference count */
     54 };
     55 
     56 /*
     57  * UVM_OBJ_KERN is a 'special' uo_refs value which indicates that the
     58  * object is a kernel memory object rather than a normal one (kernel
     59  * memory objects don't have reference counts -- they never die).
     60  *
     61  * this value is used to detected kernel object mappings at uvm_unmap()
     62  * time.   normally when an object is unmapped its pages eventaully become
     63  * deactivated and then paged out and/or freed.    this is not useful
     64  * for kernel objects... when a kernel object is unmapped we always want
     65  * to free the resources associated with the mapping.   UVM_OBJ_KERN
     66  * allows us to decide which type of unmapping we want to do.
     67  */
     68 #define UVM_OBJ_KERN		(-2)
     69 
     70 #define	UVM_OBJ_IS_KERN_OBJECT(uobj)					\
     71 	((uobj)->uo_refs == UVM_OBJ_KERN)
     72 
     73 #ifdef _KERNEL
     74 
     75 extern struct uvm_pagerops uvm_vnodeops;
     76 extern struct uvm_pagerops uvm_deviceops;
     77 extern struct uvm_pagerops ubc_pager;
     78 extern struct uvm_pagerops aobj_pager;
     79 
     80 #define	UVM_OBJ_IS_VNODE(uobj)						\
     81 	((uobj)->pgops == &uvm_vnodeops)
     82 
     83 #define	UVM_OBJ_IS_DEVICE(uobj)						\
     84 	((uobj)->pgops == &uvm_deviceops)
     85 
     86 #define	UVM_OBJ_IS_VTEXT(uobj)						\
     87 	(UVM_OBJ_IS_VNODE(uobj) && uvn_text_p(uobj))
     88 
     89 #define	UVM_OBJ_IS_CLEAN(uobj)						\
     90 	(UVM_OBJ_IS_VNODE(uobj) && uvn_clean_p(uobj))
     91 
     92 /*
     93  * UVM_OBJ_NEEDS_WRITEFAULT: true if the uobj needs to detect modification.
     94  * (ie. wants to avoid writable user mappings.)
     95  *
     96  * XXX bad name
     97  */
     98 
     99 #define	UVM_OBJ_NEEDS_WRITEFAULT(uobj)					\
    100 	(UVM_OBJ_IS_VNODE(uobj) && uvn_needs_writefault_p(uobj))
    101 
    102 #define	UVM_OBJ_IS_AOBJ(uobj)						\
    103 	((uobj)->pgops == &aobj_pager)
    104 
    105 #define	UVM_OBJ_INIT(uobj, ops, refs)					\
    106 	do {								\
    107 		simple_lock_init(&(uobj)->vmobjlock);			\
    108 		(uobj)->pgops = (ops);					\
    109 		TAILQ_INIT(&(uobj)->memq);				\
    110 		(uobj)->uo_npages = 0;					\
    111 		(uobj)->uo_refs = (refs);				\
    112 	} while (/* CONSTCOND */ 0)
    113 
    114 #endif /* _KERNEL */
    115 
    116 #endif /* _UVM_UVM_OBJECT_H_ */
    117