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uvm_object.h revision 1.27
      1 /*	$NetBSD: uvm_object.h,v 1.27 2010/09/24 22:51:51 rmind 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 rb_tree_ops_t 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_ */
    139