xref: /openbsd-src/sys/uvm/uvm_object.h (revision a192f6dd475a250b2a70a96676538867f9c74927)
1*a192f6ddSjsg /*	$OpenBSD: uvm_object.h,v 1.30 2022/09/04 06:49:11 jsg Exp $	*/
21414b0faSart /*	$NetBSD: uvm_object.h,v 1.11 2001/03/09 01:02:12 chs Exp $	*/
3cd7ee8acSart 
4cd7ee8acSart /*
5cd7ee8acSart  * Copyright (c) 1997 Charles D. Cranor and Washington University.
6cd7ee8acSart  * All rights reserved.
7cd7ee8acSart  *
8cd7ee8acSart  * Redistribution and use in source and binary forms, with or without
9cd7ee8acSart  * modification, are permitted provided that the following conditions
10cd7ee8acSart  * are met:
11cd7ee8acSart  * 1. Redistributions of source code must retain the above copyright
12cd7ee8acSart  *    notice, this list of conditions and the following disclaimer.
13cd7ee8acSart  * 2. Redistributions in binary form must reproduce the above copyright
14cd7ee8acSart  *    notice, this list of conditions and the following disclaimer in the
15cd7ee8acSart  *    documentation and/or other materials provided with the distribution.
16cd7ee8acSart  *
17cd7ee8acSart  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18cd7ee8acSart  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19cd7ee8acSart  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20cd7ee8acSart  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21cd7ee8acSart  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22cd7ee8acSart  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23cd7ee8acSart  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24cd7ee8acSart  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25cd7ee8acSart  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26cd7ee8acSart  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27cd7ee8acSart  *
28cd7ee8acSart  * from: Id: uvm_object.h,v 1.1.2.2 1998/01/04 22:44:51 chuck Exp
29cd7ee8acSart  */
30cd7ee8acSart 
31cd7ee8acSart #ifndef _UVM_UVM_OBJECT_H_
32cd7ee8acSart #define _UVM_UVM_OBJECT_H_
33cd7ee8acSart 
34cd7ee8acSart /*
3569c04514Smpi  * The UVM memory object interface.  Notes:
3669c04514Smpi  *
3769c04514Smpi  * A UVM memory object represents a list of pages, which are managed by
3869c04514Smpi  * the object's pager operations (uvm_object::pgops).  All pages belonging
3969c04514Smpi  * to an object are owned by it and thus protected by the object lock.
4069c04514Smpi  *
4169c04514Smpi  * The lock (uvm_object::vmobjlock) may be shared amongst the UVM objects.
4269c04514Smpi  * By default, the lock is allocated dynamically using rw_obj_init() cache.
4369c04514Smpi  * Lock sharing is normally used when there is an underlying object.  For
4469c04514Smpi  * example, vnode representing a file may have an underlying node, which
4569c04514Smpi  * is the case for tmpfs and layered file systems.  In such case, vnode's
4669c04514Smpi  * UVM object and the underlying UVM object shares the lock.
4769c04514Smpi  *
4869c04514Smpi  * The reference count is managed atomically for the anonymous UVM objects.
4969c04514Smpi  * For other objects, it is arbitrary (may use the lock or atomics).
50cd7ee8acSart  */
51cd7ee8acSart 
52cd7ee8acSart struct uvm_object {
5369c04514Smpi 	struct rwlock			*vmobjlock;	/* lock on object */
549f7b7ef0Smpi 	const struct uvm_pagerops	*pgops;		/* pager ops */
55262a556aSdlg 	RBT_HEAD(uvm_objtree, vm_page)	 memt;		/* pages in object */
567bcb8cc6Soga 	int				 uo_npages;	/* # of pages in memt */
57cd7ee8acSart 	int				 uo_refs;	/* reference count */
58cd7ee8acSart };
59cd7ee8acSart 
60cd7ee8acSart /*
61cd7ee8acSart  * UVM_OBJ_KERN is a 'special' uo_refs value which indicates that the
62cd7ee8acSart  * object is a kernel memory object rather than a normal one (kernel
63cd7ee8acSart  * memory objects don't have reference counts -- they never die).
64cd7ee8acSart  *
65cd7ee8acSart  * this value is used to detected kernel object mappings at uvm_unmap()
66*a192f6ddSjsg  * time.   normally when an object is unmapped its pages eventually become
67cd7ee8acSart  * deactivated and then paged out and/or freed.    this is not useful
68cd7ee8acSart  * for kernel objects... when a kernel object is unmapped we always want
69cd7ee8acSart  * to free the resources associated with the mapping.   UVM_OBJ_KERN
70cd7ee8acSart  * allows us to decide which type of unmapping we want to do.
717cb53682Sart  *
727cb53682Sart  * in addition, we have kernel objects which may be used in an
737cb53682Sart  * interrupt context.  these objects get their mappings entered
747cb53682Sart  * with pmap_kenter*() and removed with pmap_kremove(), which
757cb53682Sart  * are safe to call in interrupt context, and must be used ONLY
767cb53682Sart  * for wired kernel mappings in these objects and their associated
777cb53682Sart  * maps.
78cd7ee8acSart  */
79cd7ee8acSart #define UVM_OBJ_KERN		(-2)
807cb53682Sart 
817cb53682Sart #define	UVM_OBJ_IS_KERN_OBJECT(uobj)					\
82b7c6e7a5Sart 	((uobj)->uo_refs == UVM_OBJ_KERN)
83cd7ee8acSart 
84cac1bff1Sart #ifdef _KERNEL
85cac1bff1Sart 
869f7b7ef0Smpi extern const struct uvm_pagerops uvm_vnodeops;
879f7b7ef0Smpi extern const struct uvm_pagerops uvm_deviceops;
8894151407Smpi extern const struct uvm_pagerops pmap_pager;
8994151407Smpi extern const struct uvm_pagerops bufcache_pager;
90cac1bff1Sart 
917bcb8cc6Soga /* For object trees */
92262a556aSdlg int	uvm_pagecmp(const struct vm_page *, const struct vm_page *);
93262a556aSdlg RBT_PROTOTYPE(uvm_objtree, vm_page, objt, uvm_pagecmp)
947bcb8cc6Soga 
95cac1bff1Sart #define	UVM_OBJ_IS_VNODE(uobj)						\
96cac1bff1Sart 	((uobj)->pgops == &uvm_vnodeops)
97cac1bff1Sart 
98676bc291Sart #define	UVM_OBJ_IS_DEVICE(uobj)						\
99676bc291Sart 	((uobj)->pgops == &uvm_deviceops)
100676bc291Sart 
101cac1bff1Sart #define	UVM_OBJ_IS_VTEXT(uobj)						\
102cac1bff1Sart 	((uobj)->pgops == &uvm_vnodeops &&				\
103cac1bff1Sart 	 ((struct vnode *)uobj)->v_flag & VTEXT)
104cac1bff1Sart 
10557296fa7Smpi #define	UVM_OBJ_IS_AOBJ(uobj)						\
10657296fa7Smpi 	((uobj)->pgops == &aobj_pager)
10757296fa7Smpi 
10894151407Smpi #define UVM_OBJ_IS_PMAP(uobj)						\
10994151407Smpi 	((uobj)->pgops == &pmap_pager)
11094151407Smpi 
11194151407Smpi #define UVM_OBJ_IS_BUFCACHE(uobj)					\
11294151407Smpi 	((uobj)->pgops == &bufcache_pager)
11394151407Smpi 
11469c04514Smpi #define UVM_OBJ_IS_DUMMY(uobj)						\
11569c04514Smpi 	(UVM_OBJ_IS_PMAP(uobj) || UVM_OBJ_IS_BUFCACHE(uobj))
11669c04514Smpi 
117da3d0110Smpi void	uvm_obj_init(struct uvm_object *, const struct uvm_pagerops *, int);
1183c82a206Skettenis void	uvm_obj_destroy(struct uvm_object *);
11969c04514Smpi void	uvm_obj_setlock(struct uvm_object *, struct rwlock *);
120da3d0110Smpi int	uvm_obj_wire(struct uvm_object *, voff_t, voff_t, struct pglist *);
121da3d0110Smpi void	uvm_obj_unwire(struct uvm_object *, voff_t, voff_t);
122da3d0110Smpi void	uvm_obj_free(struct uvm_object *);
1235a9ec29bSoga 
124cac1bff1Sart #endif /* _KERNEL */
125cac1bff1Sart 
126cd7ee8acSart #endif /* _UVM_UVM_OBJECT_H_ */
127