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/* $OpenBSD: uvm_object.h,v 1.30 2022/09/04 06:49:11 jsg Exp $ */
/* $NetBSD: uvm_object.h,v 1.11 2001/03/09 01:02:12 chs Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* from: Id: uvm_object.h,v 1.1.2.2 1998/01/04 22:44:51 chuck Exp
*/
#ifndef _UVM_UVM_OBJECT_H_
#define _UVM_UVM_OBJECT_H_
/*
* The UVM memory object interface. Notes:
*
* A UVM memory object represents a list of pages, which are managed by
* the object's pager operations (uvm_object::pgops). All pages belonging
* to an object are owned by it and thus protected by the object lock.
*
* The lock (uvm_object::vmobjlock) may be shared amongst the UVM objects.
* By default, the lock is allocated dynamically using rw_obj_init() cache.
* Lock sharing is normally used when there is an underlying object. For
* example, vnode representing a file may have an underlying node, which
* is the case for tmpfs and layered file systems. In such case, vnode's
* UVM object and the underlying UVM object shares the lock.
*
* The reference count is managed atomically for the anonymous UVM objects.
* For other objects, it is arbitrary (may use the lock or atomics).
*/
struct uvm_object {
struct rwlock *vmobjlock; /* lock on object */
const struct uvm_pagerops *pgops; /* pager ops */
RBT_HEAD(uvm_objtree, vm_page) memt; /* pages in object */
int uo_npages; /* # of pages in memt */
int uo_refs; /* reference count */
};
/*
* UVM_OBJ_KERN is a 'special' uo_refs value which indicates that the
* object is a kernel memory object rather than a normal one (kernel
* memory objects don't have reference counts -- they never die).
*
* this value is used to detected kernel object mappings at uvm_unmap()
* time. normally when an object is unmapped its pages eventually become
* deactivated and then paged out and/or freed. this is not useful
* for kernel objects... when a kernel object is unmapped we always want
* to free the resources associated with the mapping. UVM_OBJ_KERN
* allows us to decide which type of unmapping we want to do.
*
* in addition, we have kernel objects which may be used in an
* interrupt context. these objects get their mappings entered
* with pmap_kenter*() and removed with pmap_kremove(), which
* are safe to call in interrupt context, and must be used ONLY
* for wired kernel mappings in these objects and their associated
* maps.
*/
#define UVM_OBJ_KERN (-2)
#define UVM_OBJ_IS_KERN_OBJECT(uobj) \
((uobj)->uo_refs == UVM_OBJ_KERN)
#ifdef _KERNEL
extern const struct uvm_pagerops uvm_vnodeops;
extern const struct uvm_pagerops uvm_deviceops;
extern const struct uvm_pagerops pmap_pager;
extern const struct uvm_pagerops bufcache_pager;
/* For object trees */
int uvm_pagecmp(const struct vm_page *, const struct vm_page *);
RBT_PROTOTYPE(uvm_objtree, vm_page, objt, uvm_pagecmp)
#define UVM_OBJ_IS_VNODE(uobj) \
((uobj)->pgops == &uvm_vnodeops)
#define UVM_OBJ_IS_DEVICE(uobj) \
((uobj)->pgops == &uvm_deviceops)
#define UVM_OBJ_IS_VTEXT(uobj) \
((uobj)->pgops == &uvm_vnodeops && \
((struct vnode *)uobj)->v_flag & VTEXT)
#define UVM_OBJ_IS_AOBJ(uobj) \
((uobj)->pgops == &aobj_pager)
#define UVM_OBJ_IS_PMAP(uobj) \
((uobj)->pgops == &pmap_pager)
#define UVM_OBJ_IS_BUFCACHE(uobj) \
((uobj)->pgops == &bufcache_pager)
#define UVM_OBJ_IS_DUMMY(uobj) \
(UVM_OBJ_IS_PMAP(uobj) || UVM_OBJ_IS_BUFCACHE(uobj))
void uvm_obj_init(struct uvm_object *, const struct uvm_pagerops *, int);
void uvm_obj_destroy(struct uvm_object *);
void uvm_obj_setlock(struct uvm_object *, struct rwlock *);
int uvm_obj_wire(struct uvm_object *, voff_t, voff_t, struct pglist *);
void uvm_obj_unwire(struct uvm_object *, voff_t, voff_t);
void uvm_obj_free(struct uvm_object *);
#endif /* _KERNEL */
#endif /* _UVM_UVM_OBJECT_H_ */
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